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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * PACKET - implements raw packet sockets.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 *
13 * Fixes:
14 * Alan Cox : verify_area() now used correctly
15 * Alan Cox : new skbuff lists, look ma no backlogs!
16 * Alan Cox : tidied skbuff lists.
17 * Alan Cox : Now uses generic datagram routines I
18 * added. Also fixed the peek/read crash
19 * from all old Linux datagram code.
20 * Alan Cox : Uses the improved datagram code.
21 * Alan Cox : Added NULL's for socket options.
22 * Alan Cox : Re-commented the code.
23 * Alan Cox : Use new kernel side addressing
24 * Rob Janssen : Correct MTU usage.
25 * Dave Platt : Counter leaks caused by incorrect
26 * interrupt locking and some slightly
27 * dubious gcc output. Can you read
28 * compiler: it said _VOLATILE_
29 * Richard Kooijman : Timestamp fixes.
30 * Alan Cox : New buffers. Use sk->mac.raw.
31 * Alan Cox : sendmsg/recvmsg support.
32 * Alan Cox : Protocol setting support
33 * Alexey Kuznetsov : Untied from IPv4 stack.
34 * Cyrus Durgin : Fixed kerneld for kmod.
35 * Michal Ostrowski : Module initialization cleanup.
36 * Ulises Alonso : Frame number limit removal and
37 * packet_set_ring memory leak.
38 * Eric Biederman : Allow for > 8 byte hardware addresses.
39 * The convention is that longer addresses
40 * will simply extend the hardware address
41 * byte arrays at the end of sockaddr_ll
42 * and packet_mreq.
43 * Johann Baudy : Added TX RING.
44 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * layer.
46 * Copyright (C) 2011, <lokec@ccs.neu.edu>
47 */
48
49#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50
51#include <linux/ethtool.h>
52#include <linux/filter.h>
53#include <linux/types.h>
54#include <linux/mm.h>
55#include <linux/capability.h>
56#include <linux/fcntl.h>
57#include <linux/socket.h>
58#include <linux/in.h>
59#include <linux/inet.h>
60#include <linux/netdevice.h>
61#include <linux/if_packet.h>
62#include <linux/wireless.h>
63#include <linux/kernel.h>
64#include <linux/kmod.h>
65#include <linux/slab.h>
66#include <linux/vmalloc.h>
67#include <net/net_namespace.h>
68#include <net/ip.h>
69#include <net/protocol.h>
70#include <linux/skbuff.h>
71#include <net/sock.h>
72#include <linux/errno.h>
73#include <linux/timer.h>
74#include <linux/uaccess.h>
75#include <asm/ioctls.h>
76#include <asm/page.h>
77#include <asm/cacheflush.h>
78#include <asm/io.h>
79#include <linux/proc_fs.h>
80#include <linux/seq_file.h>
81#include <linux/poll.h>
82#include <linux/module.h>
83#include <linux/init.h>
84#include <linux/mutex.h>
85#include <linux/if_vlan.h>
86#include <linux/virtio_net.h>
87#include <linux/errqueue.h>
88#include <linux/net_tstamp.h>
89#include <linux/percpu.h>
90#ifdef CONFIG_INET
91#include <net/inet_common.h>
92#endif
93#include <linux/bpf.h>
94#include <net/compat.h>
95#include <linux/netfilter_netdev.h>
96
97#include "internal.h"
98
99/*
100 Assumptions:
101 - If the device has no dev->header_ops->create, there is no LL header
102 visible above the device. In this case, its hard_header_len should be 0.
103 The device may prepend its own header internally. In this case, its
104 needed_headroom should be set to the space needed for it to add its
105 internal header.
106 For example, a WiFi driver pretending to be an Ethernet driver should
107 set its hard_header_len to be the Ethernet header length, and set its
108 needed_headroom to be (the real WiFi header length - the fake Ethernet
109 header length).
110 - packet socket receives packets with pulled ll header,
111 so that SOCK_RAW should push it back.
112
113On receive:
114-----------
115
116Incoming, dev_has_header(dev) == true
117 mac_header -> ll header
118 data -> data
119
120Outgoing, dev_has_header(dev) == true
121 mac_header -> ll header
122 data -> ll header
123
124Incoming, dev_has_header(dev) == false
125 mac_header -> data
126 However drivers often make it point to the ll header.
127 This is incorrect because the ll header should be invisible to us.
128 data -> data
129
130Outgoing, dev_has_header(dev) == false
131 mac_header -> data. ll header is invisible to us.
132 data -> data
133
134Resume
135 If dev_has_header(dev) == false we are unable to restore the ll header,
136 because it is invisible to us.
137
138
139On transmit:
140------------
141
142dev_has_header(dev) == true
143 mac_header -> ll header
144 data -> ll header
145
146dev_has_header(dev) == false (ll header is invisible to us)
147 mac_header -> data
148 data -> data
149
150 We should set network_header on output to the correct position,
151 packet classifier depends on it.
152 */
153
154/* Private packet socket structures. */
155
156/* identical to struct packet_mreq except it has
157 * a longer address field.
158 */
159struct packet_mreq_max {
160 int mr_ifindex;
161 unsigned short mr_type;
162 unsigned short mr_alen;
163 unsigned char mr_address[MAX_ADDR_LEN];
164};
165
166union tpacket_uhdr {
167 struct tpacket_hdr *h1;
168 struct tpacket2_hdr *h2;
169 struct tpacket3_hdr *h3;
170 void *raw;
171};
172
173static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
174 int closing, int tx_ring);
175
176#define V3_ALIGNMENT (8)
177
178#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
179
180#define BLK_PLUS_PRIV(sz_of_priv) \
181 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
182
183#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
184#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
185#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
186#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
187#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
188#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
189
190struct packet_sock;
191static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
192 struct packet_type *pt, struct net_device *orig_dev);
193
194static void *packet_previous_frame(struct packet_sock *po,
195 struct packet_ring_buffer *rb,
196 int status);
197static void packet_increment_head(struct packet_ring_buffer *buff);
198static int prb_curr_blk_in_use(struct tpacket_block_desc *);
199static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 struct packet_sock *);
201static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 struct packet_sock *, unsigned int status);
203static int prb_queue_frozen(struct tpacket_kbdq_core *);
204static void prb_open_block(struct tpacket_kbdq_core *,
205 struct tpacket_block_desc *);
206static void prb_retire_rx_blk_timer_expired(struct timer_list *);
207static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
209static void prb_clear_rxhash(struct tpacket_kbdq_core *,
210 struct tpacket3_hdr *);
211static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
212 struct tpacket3_hdr *);
213static void packet_flush_mclist(struct sock *sk);
214static u16 packet_pick_tx_queue(struct sk_buff *skb);
215
216struct packet_skb_cb {
217 union {
218 struct sockaddr_pkt pkt;
219 union {
220 /* Trick: alias skb original length with
221 * ll.sll_family and ll.protocol in order
222 * to save room.
223 */
224 unsigned int origlen;
225 struct sockaddr_ll ll;
226 };
227 } sa;
228};
229
230#define vio_le() virtio_legacy_is_little_endian()
231
232#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
233
234#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
235#define GET_PBLOCK_DESC(x, bid) \
236 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
237#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
238 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
239#define GET_NEXT_PRB_BLK_NUM(x) \
240 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
241 ((x)->kactive_blk_num+1) : 0)
242
243static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
244static void __fanout_link(struct sock *sk, struct packet_sock *po);
245
246#ifdef CONFIG_NETFILTER_EGRESS
247static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb)
248{
249 struct sk_buff *next, *head = NULL, *tail;
250 int rc;
251
252 rcu_read_lock();
253 for (; skb != NULL; skb = next) {
254 next = skb->next;
255 skb_mark_not_on_list(skb);
256
257 if (!nf_hook_egress(skb, &rc, skb->dev))
258 continue;
259
260 if (!head)
261 head = skb;
262 else
263 tail->next = skb;
264
265 tail = skb;
266 }
267 rcu_read_unlock();
268
269 return head;
270}
271#endif
272
273static int packet_xmit(const struct packet_sock *po, struct sk_buff *skb)
274{
275 if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS))
276 return dev_queue_xmit(skb);
277
278#ifdef CONFIG_NETFILTER_EGRESS
279 if (nf_hook_egress_active()) {
280 skb = nf_hook_direct_egress(skb);
281 if (!skb)
282 return NET_XMIT_DROP;
283 }
284#endif
285 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
286}
287
288static struct net_device *packet_cached_dev_get(struct packet_sock *po)
289{
290 struct net_device *dev;
291
292 rcu_read_lock();
293 dev = rcu_dereference(po->cached_dev);
294 dev_hold(dev);
295 rcu_read_unlock();
296
297 return dev;
298}
299
300static void packet_cached_dev_assign(struct packet_sock *po,
301 struct net_device *dev)
302{
303 rcu_assign_pointer(po->cached_dev, dev);
304}
305
306static void packet_cached_dev_reset(struct packet_sock *po)
307{
308 RCU_INIT_POINTER(po->cached_dev, NULL);
309}
310
311static u16 packet_pick_tx_queue(struct sk_buff *skb)
312{
313 struct net_device *dev = skb->dev;
314 const struct net_device_ops *ops = dev->netdev_ops;
315 int cpu = raw_smp_processor_id();
316 u16 queue_index;
317
318#ifdef CONFIG_XPS
319 skb->sender_cpu = cpu + 1;
320#endif
321 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
322 if (ops->ndo_select_queue) {
323 queue_index = ops->ndo_select_queue(dev, skb, NULL);
324 queue_index = netdev_cap_txqueue(dev, queue_index);
325 } else {
326 queue_index = netdev_pick_tx(dev, skb, NULL);
327 }
328
329 return queue_index;
330}
331
332/* __register_prot_hook must be invoked through register_prot_hook
333 * or from a context in which asynchronous accesses to the packet
334 * socket is not possible (packet_create()).
335 */
336static void __register_prot_hook(struct sock *sk)
337{
338 struct packet_sock *po = pkt_sk(sk);
339
340 if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
341 if (po->fanout)
342 __fanout_link(sk, po);
343 else
344 dev_add_pack(&po->prot_hook);
345
346 sock_hold(sk);
347 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1);
348 }
349}
350
351static void register_prot_hook(struct sock *sk)
352{
353 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
354 __register_prot_hook(sk);
355}
356
357/* If the sync parameter is true, we will temporarily drop
358 * the po->bind_lock and do a synchronize_net to make sure no
359 * asynchronous packet processing paths still refer to the elements
360 * of po->prot_hook. If the sync parameter is false, it is the
361 * callers responsibility to take care of this.
362 */
363static void __unregister_prot_hook(struct sock *sk, bool sync)
364{
365 struct packet_sock *po = pkt_sk(sk);
366
367 lockdep_assert_held_once(&po->bind_lock);
368
369 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0);
370
371 if (po->fanout)
372 __fanout_unlink(sk, po);
373 else
374 __dev_remove_pack(&po->prot_hook);
375
376 __sock_put(sk);
377
378 if (sync) {
379 spin_unlock(&po->bind_lock);
380 synchronize_net();
381 spin_lock(&po->bind_lock);
382 }
383}
384
385static void unregister_prot_hook(struct sock *sk, bool sync)
386{
387 struct packet_sock *po = pkt_sk(sk);
388
389 if (packet_sock_flag(po, PACKET_SOCK_RUNNING))
390 __unregister_prot_hook(sk, sync);
391}
392
393static inline struct page * __pure pgv_to_page(void *addr)
394{
395 if (is_vmalloc_addr(addr))
396 return vmalloc_to_page(addr);
397 return virt_to_page(addr);
398}
399
400static void __packet_set_status(struct packet_sock *po, void *frame, int status)
401{
402 union tpacket_uhdr h;
403
404 /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */
405
406 h.raw = frame;
407 switch (po->tp_version) {
408 case TPACKET_V1:
409 WRITE_ONCE(h.h1->tp_status, status);
410 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
411 break;
412 case TPACKET_V2:
413 WRITE_ONCE(h.h2->tp_status, status);
414 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
415 break;
416 case TPACKET_V3:
417 WRITE_ONCE(h.h3->tp_status, status);
418 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
419 break;
420 default:
421 WARN(1, "TPACKET version not supported.\n");
422 BUG();
423 }
424
425 smp_wmb();
426}
427
428static int __packet_get_status(const struct packet_sock *po, void *frame)
429{
430 union tpacket_uhdr h;
431
432 smp_rmb();
433
434 /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */
435
436 h.raw = frame;
437 switch (po->tp_version) {
438 case TPACKET_V1:
439 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
440 return READ_ONCE(h.h1->tp_status);
441 case TPACKET_V2:
442 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
443 return READ_ONCE(h.h2->tp_status);
444 case TPACKET_V3:
445 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
446 return READ_ONCE(h.h3->tp_status);
447 default:
448 WARN(1, "TPACKET version not supported.\n");
449 BUG();
450 return 0;
451 }
452}
453
454static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
455 unsigned int flags)
456{
457 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
458
459 if (shhwtstamps &&
460 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
461 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
462 return TP_STATUS_TS_RAW_HARDWARE;
463
464 if ((flags & SOF_TIMESTAMPING_SOFTWARE) &&
465 ktime_to_timespec64_cond(skb_tstamp(skb), ts))
466 return TP_STATUS_TS_SOFTWARE;
467
468 return 0;
469}
470
471static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
472 struct sk_buff *skb)
473{
474 union tpacket_uhdr h;
475 struct timespec64 ts;
476 __u32 ts_status;
477
478 if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp))))
479 return 0;
480
481 h.raw = frame;
482 /*
483 * versions 1 through 3 overflow the timestamps in y2106, since they
484 * all store the seconds in a 32-bit unsigned integer.
485 * If we create a version 4, that should have a 64-bit timestamp,
486 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
487 * nanoseconds.
488 */
489 switch (po->tp_version) {
490 case TPACKET_V1:
491 h.h1->tp_sec = ts.tv_sec;
492 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
493 break;
494 case TPACKET_V2:
495 h.h2->tp_sec = ts.tv_sec;
496 h.h2->tp_nsec = ts.tv_nsec;
497 break;
498 case TPACKET_V3:
499 h.h3->tp_sec = ts.tv_sec;
500 h.h3->tp_nsec = ts.tv_nsec;
501 break;
502 default:
503 WARN(1, "TPACKET version not supported.\n");
504 BUG();
505 }
506
507 /* one flush is safe, as both fields always lie on the same cacheline */
508 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
509 smp_wmb();
510
511 return ts_status;
512}
513
514static void *packet_lookup_frame(const struct packet_sock *po,
515 const struct packet_ring_buffer *rb,
516 unsigned int position,
517 int status)
518{
519 unsigned int pg_vec_pos, frame_offset;
520 union tpacket_uhdr h;
521
522 pg_vec_pos = position / rb->frames_per_block;
523 frame_offset = position % rb->frames_per_block;
524
525 h.raw = rb->pg_vec[pg_vec_pos].buffer +
526 (frame_offset * rb->frame_size);
527
528 if (status != __packet_get_status(po, h.raw))
529 return NULL;
530
531 return h.raw;
532}
533
534static void *packet_current_frame(struct packet_sock *po,
535 struct packet_ring_buffer *rb,
536 int status)
537{
538 return packet_lookup_frame(po, rb, rb->head, status);
539}
540
541static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
542{
543 del_timer_sync(&pkc->retire_blk_timer);
544}
545
546static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
547 struct sk_buff_head *rb_queue)
548{
549 struct tpacket_kbdq_core *pkc;
550
551 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
552
553 spin_lock_bh(&rb_queue->lock);
554 pkc->delete_blk_timer = 1;
555 spin_unlock_bh(&rb_queue->lock);
556
557 prb_del_retire_blk_timer(pkc);
558}
559
560static void prb_setup_retire_blk_timer(struct packet_sock *po)
561{
562 struct tpacket_kbdq_core *pkc;
563
564 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
565 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
566 0);
567 pkc->retire_blk_timer.expires = jiffies;
568}
569
570static int prb_calc_retire_blk_tmo(struct packet_sock *po,
571 int blk_size_in_bytes)
572{
573 struct net_device *dev;
574 unsigned int mbits, div;
575 struct ethtool_link_ksettings ecmd;
576 int err;
577
578 rtnl_lock();
579 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
580 if (unlikely(!dev)) {
581 rtnl_unlock();
582 return DEFAULT_PRB_RETIRE_TOV;
583 }
584 err = __ethtool_get_link_ksettings(dev, &ecmd);
585 rtnl_unlock();
586 if (err)
587 return DEFAULT_PRB_RETIRE_TOV;
588
589 /* If the link speed is so slow you don't really
590 * need to worry about perf anyways
591 */
592 if (ecmd.base.speed < SPEED_1000 ||
593 ecmd.base.speed == SPEED_UNKNOWN)
594 return DEFAULT_PRB_RETIRE_TOV;
595
596 div = ecmd.base.speed / 1000;
597 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
598
599 if (div)
600 mbits /= div;
601
602 if (div)
603 return mbits + 1;
604 return mbits;
605}
606
607static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
608 union tpacket_req_u *req_u)
609{
610 p1->feature_req_word = req_u->req3.tp_feature_req_word;
611}
612
613static void init_prb_bdqc(struct packet_sock *po,
614 struct packet_ring_buffer *rb,
615 struct pgv *pg_vec,
616 union tpacket_req_u *req_u)
617{
618 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
619 struct tpacket_block_desc *pbd;
620
621 memset(p1, 0x0, sizeof(*p1));
622
623 p1->knxt_seq_num = 1;
624 p1->pkbdq = pg_vec;
625 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
626 p1->pkblk_start = pg_vec[0].buffer;
627 p1->kblk_size = req_u->req3.tp_block_size;
628 p1->knum_blocks = req_u->req3.tp_block_nr;
629 p1->hdrlen = po->tp_hdrlen;
630 p1->version = po->tp_version;
631 p1->last_kactive_blk_num = 0;
632 po->stats.stats3.tp_freeze_q_cnt = 0;
633 if (req_u->req3.tp_retire_blk_tov)
634 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
635 else
636 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
637 req_u->req3.tp_block_size);
638 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
639 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
640 rwlock_init(&p1->blk_fill_in_prog_lock);
641
642 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
643 prb_init_ft_ops(p1, req_u);
644 prb_setup_retire_blk_timer(po);
645 prb_open_block(p1, pbd);
646}
647
648/* Do NOT update the last_blk_num first.
649 * Assumes sk_buff_head lock is held.
650 */
651static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
652{
653 mod_timer(&pkc->retire_blk_timer,
654 jiffies + pkc->tov_in_jiffies);
655 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
656}
657
658/*
659 * Timer logic:
660 * 1) We refresh the timer only when we open a block.
661 * By doing this we don't waste cycles refreshing the timer
662 * on packet-by-packet basis.
663 *
664 * With a 1MB block-size, on a 1Gbps line, it will take
665 * i) ~8 ms to fill a block + ii) memcpy etc.
666 * In this cut we are not accounting for the memcpy time.
667 *
668 * So, if the user sets the 'tmo' to 10ms then the timer
669 * will never fire while the block is still getting filled
670 * (which is what we want). However, the user could choose
671 * to close a block early and that's fine.
672 *
673 * But when the timer does fire, we check whether or not to refresh it.
674 * Since the tmo granularity is in msecs, it is not too expensive
675 * to refresh the timer, lets say every '8' msecs.
676 * Either the user can set the 'tmo' or we can derive it based on
677 * a) line-speed and b) block-size.
678 * prb_calc_retire_blk_tmo() calculates the tmo.
679 *
680 */
681static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
682{
683 struct packet_sock *po =
684 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
685 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
686 unsigned int frozen;
687 struct tpacket_block_desc *pbd;
688
689 spin_lock(&po->sk.sk_receive_queue.lock);
690
691 frozen = prb_queue_frozen(pkc);
692 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
693
694 if (unlikely(pkc->delete_blk_timer))
695 goto out;
696
697 /* We only need to plug the race when the block is partially filled.
698 * tpacket_rcv:
699 * lock(); increment BLOCK_NUM_PKTS; unlock()
700 * copy_bits() is in progress ...
701 * timer fires on other cpu:
702 * we can't retire the current block because copy_bits
703 * is in progress.
704 *
705 */
706 if (BLOCK_NUM_PKTS(pbd)) {
707 /* Waiting for skb_copy_bits to finish... */
708 write_lock(&pkc->blk_fill_in_prog_lock);
709 write_unlock(&pkc->blk_fill_in_prog_lock);
710 }
711
712 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
713 if (!frozen) {
714 if (!BLOCK_NUM_PKTS(pbd)) {
715 /* An empty block. Just refresh the timer. */
716 goto refresh_timer;
717 }
718 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
719 if (!prb_dispatch_next_block(pkc, po))
720 goto refresh_timer;
721 else
722 goto out;
723 } else {
724 /* Case 1. Queue was frozen because user-space was
725 * lagging behind.
726 */
727 if (prb_curr_blk_in_use(pbd)) {
728 /*
729 * Ok, user-space is still behind.
730 * So just refresh the timer.
731 */
732 goto refresh_timer;
733 } else {
734 /* Case 2. queue was frozen,user-space caught up,
735 * now the link went idle && the timer fired.
736 * We don't have a block to close.So we open this
737 * block and restart the timer.
738 * opening a block thaws the queue,restarts timer
739 * Thawing/timer-refresh is a side effect.
740 */
741 prb_open_block(pkc, pbd);
742 goto out;
743 }
744 }
745 }
746
747refresh_timer:
748 _prb_refresh_rx_retire_blk_timer(pkc);
749
750out:
751 spin_unlock(&po->sk.sk_receive_queue.lock);
752}
753
754static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
755 struct tpacket_block_desc *pbd1, __u32 status)
756{
757 /* Flush everything minus the block header */
758
759#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
760 u8 *start, *end;
761
762 start = (u8 *)pbd1;
763
764 /* Skip the block header(we know header WILL fit in 4K) */
765 start += PAGE_SIZE;
766
767 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
768 for (; start < end; start += PAGE_SIZE)
769 flush_dcache_page(pgv_to_page(start));
770
771 smp_wmb();
772#endif
773
774 /* Now update the block status. */
775
776 BLOCK_STATUS(pbd1) = status;
777
778 /* Flush the block header */
779
780#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
781 start = (u8 *)pbd1;
782 flush_dcache_page(pgv_to_page(start));
783
784 smp_wmb();
785#endif
786}
787
788/*
789 * Side effect:
790 *
791 * 1) flush the block
792 * 2) Increment active_blk_num
793 *
794 * Note:We DONT refresh the timer on purpose.
795 * Because almost always the next block will be opened.
796 */
797static void prb_close_block(struct tpacket_kbdq_core *pkc1,
798 struct tpacket_block_desc *pbd1,
799 struct packet_sock *po, unsigned int stat)
800{
801 __u32 status = TP_STATUS_USER | stat;
802
803 struct tpacket3_hdr *last_pkt;
804 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
805 struct sock *sk = &po->sk;
806
807 if (atomic_read(&po->tp_drops))
808 status |= TP_STATUS_LOSING;
809
810 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
811 last_pkt->tp_next_offset = 0;
812
813 /* Get the ts of the last pkt */
814 if (BLOCK_NUM_PKTS(pbd1)) {
815 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
816 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
817 } else {
818 /* Ok, we tmo'd - so get the current time.
819 *
820 * It shouldn't really happen as we don't close empty
821 * blocks. See prb_retire_rx_blk_timer_expired().
822 */
823 struct timespec64 ts;
824 ktime_get_real_ts64(&ts);
825 h1->ts_last_pkt.ts_sec = ts.tv_sec;
826 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
827 }
828
829 smp_wmb();
830
831 /* Flush the block */
832 prb_flush_block(pkc1, pbd1, status);
833
834 sk->sk_data_ready(sk);
835
836 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
837}
838
839static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
840{
841 pkc->reset_pending_on_curr_blk = 0;
842}
843
844/*
845 * Side effect of opening a block:
846 *
847 * 1) prb_queue is thawed.
848 * 2) retire_blk_timer is refreshed.
849 *
850 */
851static void prb_open_block(struct tpacket_kbdq_core *pkc1,
852 struct tpacket_block_desc *pbd1)
853{
854 struct timespec64 ts;
855 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
856
857 smp_rmb();
858
859 /* We could have just memset this but we will lose the
860 * flexibility of making the priv area sticky
861 */
862
863 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
864 BLOCK_NUM_PKTS(pbd1) = 0;
865 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
866
867 ktime_get_real_ts64(&ts);
868
869 h1->ts_first_pkt.ts_sec = ts.tv_sec;
870 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
871
872 pkc1->pkblk_start = (char *)pbd1;
873 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
874
875 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
876 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
877
878 pbd1->version = pkc1->version;
879 pkc1->prev = pkc1->nxt_offset;
880 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
881
882 prb_thaw_queue(pkc1);
883 _prb_refresh_rx_retire_blk_timer(pkc1);
884
885 smp_wmb();
886}
887
888/*
889 * Queue freeze logic:
890 * 1) Assume tp_block_nr = 8 blocks.
891 * 2) At time 't0', user opens Rx ring.
892 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
893 * 4) user-space is either sleeping or processing block '0'.
894 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
895 * it will close block-7,loop around and try to fill block '0'.
896 * call-flow:
897 * __packet_lookup_frame_in_block
898 * prb_retire_current_block()
899 * prb_dispatch_next_block()
900 * |->(BLOCK_STATUS == USER) evaluates to true
901 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
902 * 6) Now there are two cases:
903 * 6.1) Link goes idle right after the queue is frozen.
904 * But remember, the last open_block() refreshed the timer.
905 * When this timer expires,it will refresh itself so that we can
906 * re-open block-0 in near future.
907 * 6.2) Link is busy and keeps on receiving packets. This is a simple
908 * case and __packet_lookup_frame_in_block will check if block-0
909 * is free and can now be re-used.
910 */
911static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
912 struct packet_sock *po)
913{
914 pkc->reset_pending_on_curr_blk = 1;
915 po->stats.stats3.tp_freeze_q_cnt++;
916}
917
918#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
919
920/*
921 * If the next block is free then we will dispatch it
922 * and return a good offset.
923 * Else, we will freeze the queue.
924 * So, caller must check the return value.
925 */
926static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
927 struct packet_sock *po)
928{
929 struct tpacket_block_desc *pbd;
930
931 smp_rmb();
932
933 /* 1. Get current block num */
934 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
935
936 /* 2. If this block is currently in_use then freeze the queue */
937 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
938 prb_freeze_queue(pkc, po);
939 return NULL;
940 }
941
942 /*
943 * 3.
944 * open this block and return the offset where the first packet
945 * needs to get stored.
946 */
947 prb_open_block(pkc, pbd);
948 return (void *)pkc->nxt_offset;
949}
950
951static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
952 struct packet_sock *po, unsigned int status)
953{
954 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
955
956 /* retire/close the current block */
957 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
958 /*
959 * Plug the case where copy_bits() is in progress on
960 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
961 * have space to copy the pkt in the current block and
962 * called prb_retire_current_block()
963 *
964 * We don't need to worry about the TMO case because
965 * the timer-handler already handled this case.
966 */
967 if (!(status & TP_STATUS_BLK_TMO)) {
968 /* Waiting for skb_copy_bits to finish... */
969 write_lock(&pkc->blk_fill_in_prog_lock);
970 write_unlock(&pkc->blk_fill_in_prog_lock);
971 }
972 prb_close_block(pkc, pbd, po, status);
973 return;
974 }
975}
976
977static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
978{
979 return TP_STATUS_USER & BLOCK_STATUS(pbd);
980}
981
982static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
983{
984 return pkc->reset_pending_on_curr_blk;
985}
986
987static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
988 __releases(&pkc->blk_fill_in_prog_lock)
989{
990 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
991
992 read_unlock(&pkc->blk_fill_in_prog_lock);
993}
994
995static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
996 struct tpacket3_hdr *ppd)
997{
998 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
999}
1000
1001static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
1002 struct tpacket3_hdr *ppd)
1003{
1004 ppd->hv1.tp_rxhash = 0;
1005}
1006
1007static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1008 struct tpacket3_hdr *ppd)
1009{
1010 if (skb_vlan_tag_present(pkc->skb)) {
1011 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1012 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1013 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1014 } else {
1015 ppd->hv1.tp_vlan_tci = 0;
1016 ppd->hv1.tp_vlan_tpid = 0;
1017 ppd->tp_status = TP_STATUS_AVAILABLE;
1018 }
1019}
1020
1021static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1022 struct tpacket3_hdr *ppd)
1023{
1024 ppd->hv1.tp_padding = 0;
1025 prb_fill_vlan_info(pkc, ppd);
1026
1027 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1028 prb_fill_rxhash(pkc, ppd);
1029 else
1030 prb_clear_rxhash(pkc, ppd);
1031}
1032
1033static void prb_fill_curr_block(char *curr,
1034 struct tpacket_kbdq_core *pkc,
1035 struct tpacket_block_desc *pbd,
1036 unsigned int len)
1037 __acquires(&pkc->blk_fill_in_prog_lock)
1038{
1039 struct tpacket3_hdr *ppd;
1040
1041 ppd = (struct tpacket3_hdr *)curr;
1042 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1043 pkc->prev = curr;
1044 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1045 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1046 BLOCK_NUM_PKTS(pbd) += 1;
1047 read_lock(&pkc->blk_fill_in_prog_lock);
1048 prb_run_all_ft_ops(pkc, ppd);
1049}
1050
1051/* Assumes caller has the sk->rx_queue.lock */
1052static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1053 struct sk_buff *skb,
1054 unsigned int len
1055 )
1056{
1057 struct tpacket_kbdq_core *pkc;
1058 struct tpacket_block_desc *pbd;
1059 char *curr, *end;
1060
1061 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1062 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1063
1064 /* Queue is frozen when user space is lagging behind */
1065 if (prb_queue_frozen(pkc)) {
1066 /*
1067 * Check if that last block which caused the queue to freeze,
1068 * is still in_use by user-space.
1069 */
1070 if (prb_curr_blk_in_use(pbd)) {
1071 /* Can't record this packet */
1072 return NULL;
1073 } else {
1074 /*
1075 * Ok, the block was released by user-space.
1076 * Now let's open that block.
1077 * opening a block also thaws the queue.
1078 * Thawing is a side effect.
1079 */
1080 prb_open_block(pkc, pbd);
1081 }
1082 }
1083
1084 smp_mb();
1085 curr = pkc->nxt_offset;
1086 pkc->skb = skb;
1087 end = (char *)pbd + pkc->kblk_size;
1088
1089 /* first try the current block */
1090 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1091 prb_fill_curr_block(curr, pkc, pbd, len);
1092 return (void *)curr;
1093 }
1094
1095 /* Ok, close the current block */
1096 prb_retire_current_block(pkc, po, 0);
1097
1098 /* Now, try to dispatch the next block */
1099 curr = (char *)prb_dispatch_next_block(pkc, po);
1100 if (curr) {
1101 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1102 prb_fill_curr_block(curr, pkc, pbd, len);
1103 return (void *)curr;
1104 }
1105
1106 /*
1107 * No free blocks are available.user_space hasn't caught up yet.
1108 * Queue was just frozen and now this packet will get dropped.
1109 */
1110 return NULL;
1111}
1112
1113static void *packet_current_rx_frame(struct packet_sock *po,
1114 struct sk_buff *skb,
1115 int status, unsigned int len)
1116{
1117 char *curr = NULL;
1118 switch (po->tp_version) {
1119 case TPACKET_V1:
1120 case TPACKET_V2:
1121 curr = packet_lookup_frame(po, &po->rx_ring,
1122 po->rx_ring.head, status);
1123 return curr;
1124 case TPACKET_V3:
1125 return __packet_lookup_frame_in_block(po, skb, len);
1126 default:
1127 WARN(1, "TPACKET version not supported\n");
1128 BUG();
1129 return NULL;
1130 }
1131}
1132
1133static void *prb_lookup_block(const struct packet_sock *po,
1134 const struct packet_ring_buffer *rb,
1135 unsigned int idx,
1136 int status)
1137{
1138 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1139 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1140
1141 if (status != BLOCK_STATUS(pbd))
1142 return NULL;
1143 return pbd;
1144}
1145
1146static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1147{
1148 unsigned int prev;
1149 if (rb->prb_bdqc.kactive_blk_num)
1150 prev = rb->prb_bdqc.kactive_blk_num-1;
1151 else
1152 prev = rb->prb_bdqc.knum_blocks-1;
1153 return prev;
1154}
1155
1156/* Assumes caller has held the rx_queue.lock */
1157static void *__prb_previous_block(struct packet_sock *po,
1158 struct packet_ring_buffer *rb,
1159 int status)
1160{
1161 unsigned int previous = prb_previous_blk_num(rb);
1162 return prb_lookup_block(po, rb, previous, status);
1163}
1164
1165static void *packet_previous_rx_frame(struct packet_sock *po,
1166 struct packet_ring_buffer *rb,
1167 int status)
1168{
1169 if (po->tp_version <= TPACKET_V2)
1170 return packet_previous_frame(po, rb, status);
1171
1172 return __prb_previous_block(po, rb, status);
1173}
1174
1175static void packet_increment_rx_head(struct packet_sock *po,
1176 struct packet_ring_buffer *rb)
1177{
1178 switch (po->tp_version) {
1179 case TPACKET_V1:
1180 case TPACKET_V2:
1181 return packet_increment_head(rb);
1182 case TPACKET_V3:
1183 default:
1184 WARN(1, "TPACKET version not supported.\n");
1185 BUG();
1186 return;
1187 }
1188}
1189
1190static void *packet_previous_frame(struct packet_sock *po,
1191 struct packet_ring_buffer *rb,
1192 int status)
1193{
1194 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1195 return packet_lookup_frame(po, rb, previous, status);
1196}
1197
1198static void packet_increment_head(struct packet_ring_buffer *buff)
1199{
1200 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1201}
1202
1203static void packet_inc_pending(struct packet_ring_buffer *rb)
1204{
1205 this_cpu_inc(*rb->pending_refcnt);
1206}
1207
1208static void packet_dec_pending(struct packet_ring_buffer *rb)
1209{
1210 this_cpu_dec(*rb->pending_refcnt);
1211}
1212
1213static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1214{
1215 unsigned int refcnt = 0;
1216 int cpu;
1217
1218 /* We don't use pending refcount in rx_ring. */
1219 if (rb->pending_refcnt == NULL)
1220 return 0;
1221
1222 for_each_possible_cpu(cpu)
1223 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1224
1225 return refcnt;
1226}
1227
1228static int packet_alloc_pending(struct packet_sock *po)
1229{
1230 po->rx_ring.pending_refcnt = NULL;
1231
1232 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1233 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1234 return -ENOBUFS;
1235
1236 return 0;
1237}
1238
1239static void packet_free_pending(struct packet_sock *po)
1240{
1241 free_percpu(po->tx_ring.pending_refcnt);
1242}
1243
1244#define ROOM_POW_OFF 2
1245#define ROOM_NONE 0x0
1246#define ROOM_LOW 0x1
1247#define ROOM_NORMAL 0x2
1248
1249static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1250{
1251 int idx, len;
1252
1253 len = READ_ONCE(po->rx_ring.frame_max) + 1;
1254 idx = READ_ONCE(po->rx_ring.head);
1255 if (pow_off)
1256 idx += len >> pow_off;
1257 if (idx >= len)
1258 idx -= len;
1259 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1260}
1261
1262static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1263{
1264 int idx, len;
1265
1266 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1267 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1268 if (pow_off)
1269 idx += len >> pow_off;
1270 if (idx >= len)
1271 idx -= len;
1272 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1273}
1274
1275static int __packet_rcv_has_room(const struct packet_sock *po,
1276 const struct sk_buff *skb)
1277{
1278 const struct sock *sk = &po->sk;
1279 int ret = ROOM_NONE;
1280
1281 if (po->prot_hook.func != tpacket_rcv) {
1282 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1283 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1284 - (skb ? skb->truesize : 0);
1285
1286 if (avail > (rcvbuf >> ROOM_POW_OFF))
1287 return ROOM_NORMAL;
1288 else if (avail > 0)
1289 return ROOM_LOW;
1290 else
1291 return ROOM_NONE;
1292 }
1293
1294 if (po->tp_version == TPACKET_V3) {
1295 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1296 ret = ROOM_NORMAL;
1297 else if (__tpacket_v3_has_room(po, 0))
1298 ret = ROOM_LOW;
1299 } else {
1300 if (__tpacket_has_room(po, ROOM_POW_OFF))
1301 ret = ROOM_NORMAL;
1302 else if (__tpacket_has_room(po, 0))
1303 ret = ROOM_LOW;
1304 }
1305
1306 return ret;
1307}
1308
1309static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1310{
1311 bool pressure;
1312 int ret;
1313
1314 ret = __packet_rcv_has_room(po, skb);
1315 pressure = ret != ROOM_NORMAL;
1316
1317 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure)
1318 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure);
1319
1320 return ret;
1321}
1322
1323static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1324{
1325 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) &&
1326 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1327 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false);
1328}
1329
1330static void packet_sock_destruct(struct sock *sk)
1331{
1332 skb_queue_purge(&sk->sk_error_queue);
1333
1334 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1335 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1336
1337 if (!sock_flag(sk, SOCK_DEAD)) {
1338 pr_err("Attempt to release alive packet socket: %p\n", sk);
1339 return;
1340 }
1341}
1342
1343static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1344{
1345 u32 *history = po->rollover->history;
1346 u32 victim, rxhash;
1347 int i, count = 0;
1348
1349 rxhash = skb_get_hash(skb);
1350 for (i = 0; i < ROLLOVER_HLEN; i++)
1351 if (READ_ONCE(history[i]) == rxhash)
1352 count++;
1353
1354 victim = get_random_u32_below(ROLLOVER_HLEN);
1355
1356 /* Avoid dirtying the cache line if possible */
1357 if (READ_ONCE(history[victim]) != rxhash)
1358 WRITE_ONCE(history[victim], rxhash);
1359
1360 return count > (ROLLOVER_HLEN >> 1);
1361}
1362
1363static unsigned int fanout_demux_hash(struct packet_fanout *f,
1364 struct sk_buff *skb,
1365 unsigned int num)
1366{
1367 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1368}
1369
1370static unsigned int fanout_demux_lb(struct packet_fanout *f,
1371 struct sk_buff *skb,
1372 unsigned int num)
1373{
1374 unsigned int val = atomic_inc_return(&f->rr_cur);
1375
1376 return val % num;
1377}
1378
1379static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1380 struct sk_buff *skb,
1381 unsigned int num)
1382{
1383 return smp_processor_id() % num;
1384}
1385
1386static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1387 struct sk_buff *skb,
1388 unsigned int num)
1389{
1390 return get_random_u32_below(num);
1391}
1392
1393static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1394 struct sk_buff *skb,
1395 unsigned int idx, bool try_self,
1396 unsigned int num)
1397{
1398 struct packet_sock *po, *po_next, *po_skip = NULL;
1399 unsigned int i, j, room = ROOM_NONE;
1400
1401 po = pkt_sk(rcu_dereference(f->arr[idx]));
1402
1403 if (try_self) {
1404 room = packet_rcv_has_room(po, skb);
1405 if (room == ROOM_NORMAL ||
1406 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1407 return idx;
1408 po_skip = po;
1409 }
1410
1411 i = j = min_t(int, po->rollover->sock, num - 1);
1412 do {
1413 po_next = pkt_sk(rcu_dereference(f->arr[i]));
1414 if (po_next != po_skip &&
1415 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) &&
1416 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1417 if (i != j)
1418 po->rollover->sock = i;
1419 atomic_long_inc(&po->rollover->num);
1420 if (room == ROOM_LOW)
1421 atomic_long_inc(&po->rollover->num_huge);
1422 return i;
1423 }
1424
1425 if (++i == num)
1426 i = 0;
1427 } while (i != j);
1428
1429 atomic_long_inc(&po->rollover->num_failed);
1430 return idx;
1431}
1432
1433static unsigned int fanout_demux_qm(struct packet_fanout *f,
1434 struct sk_buff *skb,
1435 unsigned int num)
1436{
1437 return skb_get_queue_mapping(skb) % num;
1438}
1439
1440static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1441 struct sk_buff *skb,
1442 unsigned int num)
1443{
1444 struct bpf_prog *prog;
1445 unsigned int ret = 0;
1446
1447 rcu_read_lock();
1448 prog = rcu_dereference(f->bpf_prog);
1449 if (prog)
1450 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1451 rcu_read_unlock();
1452
1453 return ret;
1454}
1455
1456static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1457{
1458 return f->flags & (flag >> 8);
1459}
1460
1461static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1462 struct packet_type *pt, struct net_device *orig_dev)
1463{
1464 struct packet_fanout *f = pt->af_packet_priv;
1465 unsigned int num = READ_ONCE(f->num_members);
1466 struct net *net = read_pnet(&f->net);
1467 struct packet_sock *po;
1468 unsigned int idx;
1469
1470 if (!net_eq(dev_net(dev), net) || !num) {
1471 kfree_skb(skb);
1472 return 0;
1473 }
1474
1475 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1476 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1477 if (!skb)
1478 return 0;
1479 }
1480 switch (f->type) {
1481 case PACKET_FANOUT_HASH:
1482 default:
1483 idx = fanout_demux_hash(f, skb, num);
1484 break;
1485 case PACKET_FANOUT_LB:
1486 idx = fanout_demux_lb(f, skb, num);
1487 break;
1488 case PACKET_FANOUT_CPU:
1489 idx = fanout_demux_cpu(f, skb, num);
1490 break;
1491 case PACKET_FANOUT_RND:
1492 idx = fanout_demux_rnd(f, skb, num);
1493 break;
1494 case PACKET_FANOUT_QM:
1495 idx = fanout_demux_qm(f, skb, num);
1496 break;
1497 case PACKET_FANOUT_ROLLOVER:
1498 idx = fanout_demux_rollover(f, skb, 0, false, num);
1499 break;
1500 case PACKET_FANOUT_CBPF:
1501 case PACKET_FANOUT_EBPF:
1502 idx = fanout_demux_bpf(f, skb, num);
1503 break;
1504 }
1505
1506 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1507 idx = fanout_demux_rollover(f, skb, idx, true, num);
1508
1509 po = pkt_sk(rcu_dereference(f->arr[idx]));
1510 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1511}
1512
1513DEFINE_MUTEX(fanout_mutex);
1514EXPORT_SYMBOL_GPL(fanout_mutex);
1515static LIST_HEAD(fanout_list);
1516static u16 fanout_next_id;
1517
1518static void __fanout_link(struct sock *sk, struct packet_sock *po)
1519{
1520 struct packet_fanout *f = po->fanout;
1521
1522 spin_lock(&f->lock);
1523 rcu_assign_pointer(f->arr[f->num_members], sk);
1524 smp_wmb();
1525 f->num_members++;
1526 if (f->num_members == 1)
1527 dev_add_pack(&f->prot_hook);
1528 spin_unlock(&f->lock);
1529}
1530
1531static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1532{
1533 struct packet_fanout *f = po->fanout;
1534 int i;
1535
1536 spin_lock(&f->lock);
1537 for (i = 0; i < f->num_members; i++) {
1538 if (rcu_dereference_protected(f->arr[i],
1539 lockdep_is_held(&f->lock)) == sk)
1540 break;
1541 }
1542 BUG_ON(i >= f->num_members);
1543 rcu_assign_pointer(f->arr[i],
1544 rcu_dereference_protected(f->arr[f->num_members - 1],
1545 lockdep_is_held(&f->lock)));
1546 f->num_members--;
1547 if (f->num_members == 0)
1548 __dev_remove_pack(&f->prot_hook);
1549 spin_unlock(&f->lock);
1550}
1551
1552static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1553{
1554 if (sk->sk_family != PF_PACKET)
1555 return false;
1556
1557 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1558}
1559
1560static void fanout_init_data(struct packet_fanout *f)
1561{
1562 switch (f->type) {
1563 case PACKET_FANOUT_LB:
1564 atomic_set(&f->rr_cur, 0);
1565 break;
1566 case PACKET_FANOUT_CBPF:
1567 case PACKET_FANOUT_EBPF:
1568 RCU_INIT_POINTER(f->bpf_prog, NULL);
1569 break;
1570 }
1571}
1572
1573static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1574{
1575 struct bpf_prog *old;
1576
1577 spin_lock(&f->lock);
1578 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1579 rcu_assign_pointer(f->bpf_prog, new);
1580 spin_unlock(&f->lock);
1581
1582 if (old) {
1583 synchronize_net();
1584 bpf_prog_destroy(old);
1585 }
1586}
1587
1588static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1589 unsigned int len)
1590{
1591 struct bpf_prog *new;
1592 struct sock_fprog fprog;
1593 int ret;
1594
1595 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1596 return -EPERM;
1597
1598 ret = copy_bpf_fprog_from_user(&fprog, data, len);
1599 if (ret)
1600 return ret;
1601
1602 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1603 if (ret)
1604 return ret;
1605
1606 __fanout_set_data_bpf(po->fanout, new);
1607 return 0;
1608}
1609
1610static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1611 unsigned int len)
1612{
1613 struct bpf_prog *new;
1614 u32 fd;
1615
1616 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1617 return -EPERM;
1618 if (len != sizeof(fd))
1619 return -EINVAL;
1620 if (copy_from_sockptr(&fd, data, len))
1621 return -EFAULT;
1622
1623 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1624 if (IS_ERR(new))
1625 return PTR_ERR(new);
1626
1627 __fanout_set_data_bpf(po->fanout, new);
1628 return 0;
1629}
1630
1631static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1632 unsigned int len)
1633{
1634 switch (po->fanout->type) {
1635 case PACKET_FANOUT_CBPF:
1636 return fanout_set_data_cbpf(po, data, len);
1637 case PACKET_FANOUT_EBPF:
1638 return fanout_set_data_ebpf(po, data, len);
1639 default:
1640 return -EINVAL;
1641 }
1642}
1643
1644static void fanout_release_data(struct packet_fanout *f)
1645{
1646 switch (f->type) {
1647 case PACKET_FANOUT_CBPF:
1648 case PACKET_FANOUT_EBPF:
1649 __fanout_set_data_bpf(f, NULL);
1650 }
1651}
1652
1653static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1654{
1655 struct packet_fanout *f;
1656
1657 list_for_each_entry(f, &fanout_list, list) {
1658 if (f->id == candidate_id &&
1659 read_pnet(&f->net) == sock_net(sk)) {
1660 return false;
1661 }
1662 }
1663 return true;
1664}
1665
1666static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1667{
1668 u16 id = fanout_next_id;
1669
1670 do {
1671 if (__fanout_id_is_free(sk, id)) {
1672 *new_id = id;
1673 fanout_next_id = id + 1;
1674 return true;
1675 }
1676
1677 id++;
1678 } while (id != fanout_next_id);
1679
1680 return false;
1681}
1682
1683static int fanout_add(struct sock *sk, struct fanout_args *args)
1684{
1685 struct packet_rollover *rollover = NULL;
1686 struct packet_sock *po = pkt_sk(sk);
1687 u16 type_flags = args->type_flags;
1688 struct packet_fanout *f, *match;
1689 u8 type = type_flags & 0xff;
1690 u8 flags = type_flags >> 8;
1691 u16 id = args->id;
1692 int err;
1693
1694 switch (type) {
1695 case PACKET_FANOUT_ROLLOVER:
1696 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1697 return -EINVAL;
1698 break;
1699 case PACKET_FANOUT_HASH:
1700 case PACKET_FANOUT_LB:
1701 case PACKET_FANOUT_CPU:
1702 case PACKET_FANOUT_RND:
1703 case PACKET_FANOUT_QM:
1704 case PACKET_FANOUT_CBPF:
1705 case PACKET_FANOUT_EBPF:
1706 break;
1707 default:
1708 return -EINVAL;
1709 }
1710
1711 mutex_lock(&fanout_mutex);
1712
1713 err = -EALREADY;
1714 if (po->fanout)
1715 goto out;
1716
1717 if (type == PACKET_FANOUT_ROLLOVER ||
1718 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1719 err = -ENOMEM;
1720 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1721 if (!rollover)
1722 goto out;
1723 atomic_long_set(&rollover->num, 0);
1724 atomic_long_set(&rollover->num_huge, 0);
1725 atomic_long_set(&rollover->num_failed, 0);
1726 }
1727
1728 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1729 if (id != 0) {
1730 err = -EINVAL;
1731 goto out;
1732 }
1733 if (!fanout_find_new_id(sk, &id)) {
1734 err = -ENOMEM;
1735 goto out;
1736 }
1737 /* ephemeral flag for the first socket in the group: drop it */
1738 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1739 }
1740
1741 match = NULL;
1742 list_for_each_entry(f, &fanout_list, list) {
1743 if (f->id == id &&
1744 read_pnet(&f->net) == sock_net(sk)) {
1745 match = f;
1746 break;
1747 }
1748 }
1749 err = -EINVAL;
1750 if (match) {
1751 if (match->flags != flags)
1752 goto out;
1753 if (args->max_num_members &&
1754 args->max_num_members != match->max_num_members)
1755 goto out;
1756 } else {
1757 if (args->max_num_members > PACKET_FANOUT_MAX)
1758 goto out;
1759 if (!args->max_num_members)
1760 /* legacy PACKET_FANOUT_MAX */
1761 args->max_num_members = 256;
1762 err = -ENOMEM;
1763 match = kvzalloc(struct_size(match, arr, args->max_num_members),
1764 GFP_KERNEL);
1765 if (!match)
1766 goto out;
1767 write_pnet(&match->net, sock_net(sk));
1768 match->id = id;
1769 match->type = type;
1770 match->flags = flags;
1771 INIT_LIST_HEAD(&match->list);
1772 spin_lock_init(&match->lock);
1773 refcount_set(&match->sk_ref, 0);
1774 fanout_init_data(match);
1775 match->prot_hook.type = po->prot_hook.type;
1776 match->prot_hook.dev = po->prot_hook.dev;
1777 match->prot_hook.func = packet_rcv_fanout;
1778 match->prot_hook.af_packet_priv = match;
1779 match->prot_hook.af_packet_net = read_pnet(&match->net);
1780 match->prot_hook.id_match = match_fanout_group;
1781 match->max_num_members = args->max_num_members;
1782 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING;
1783 list_add(&match->list, &fanout_list);
1784 }
1785 err = -EINVAL;
1786
1787 spin_lock(&po->bind_lock);
1788 if (packet_sock_flag(po, PACKET_SOCK_RUNNING) &&
1789 match->type == type &&
1790 match->prot_hook.type == po->prot_hook.type &&
1791 match->prot_hook.dev == po->prot_hook.dev) {
1792 err = -ENOSPC;
1793 if (refcount_read(&match->sk_ref) < match->max_num_members) {
1794 __dev_remove_pack(&po->prot_hook);
1795
1796 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
1797 WRITE_ONCE(po->fanout, match);
1798
1799 po->rollover = rollover;
1800 rollover = NULL;
1801 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1802 __fanout_link(sk, po);
1803 err = 0;
1804 }
1805 }
1806 spin_unlock(&po->bind_lock);
1807
1808 if (err && !refcount_read(&match->sk_ref)) {
1809 list_del(&match->list);
1810 kvfree(match);
1811 }
1812
1813out:
1814 kfree(rollover);
1815 mutex_unlock(&fanout_mutex);
1816 return err;
1817}
1818
1819/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1820 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1821 * It is the responsibility of the caller to call fanout_release_data() and
1822 * free the returned packet_fanout (after synchronize_net())
1823 */
1824static struct packet_fanout *fanout_release(struct sock *sk)
1825{
1826 struct packet_sock *po = pkt_sk(sk);
1827 struct packet_fanout *f;
1828
1829 mutex_lock(&fanout_mutex);
1830 f = po->fanout;
1831 if (f) {
1832 po->fanout = NULL;
1833
1834 if (refcount_dec_and_test(&f->sk_ref))
1835 list_del(&f->list);
1836 else
1837 f = NULL;
1838 }
1839 mutex_unlock(&fanout_mutex);
1840
1841 return f;
1842}
1843
1844static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1845 struct sk_buff *skb)
1846{
1847 /* Earlier code assumed this would be a VLAN pkt, double-check
1848 * this now that we have the actual packet in hand. We can only
1849 * do this check on Ethernet devices.
1850 */
1851 if (unlikely(dev->type != ARPHRD_ETHER))
1852 return false;
1853
1854 skb_reset_mac_header(skb);
1855 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1856}
1857
1858static const struct proto_ops packet_ops;
1859
1860static const struct proto_ops packet_ops_spkt;
1861
1862static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1863 struct packet_type *pt, struct net_device *orig_dev)
1864{
1865 struct sock *sk;
1866 struct sockaddr_pkt *spkt;
1867
1868 /*
1869 * When we registered the protocol we saved the socket in the data
1870 * field for just this event.
1871 */
1872
1873 sk = pt->af_packet_priv;
1874
1875 /*
1876 * Yank back the headers [hope the device set this
1877 * right or kerboom...]
1878 *
1879 * Incoming packets have ll header pulled,
1880 * push it back.
1881 *
1882 * For outgoing ones skb->data == skb_mac_header(skb)
1883 * so that this procedure is noop.
1884 */
1885
1886 if (skb->pkt_type == PACKET_LOOPBACK)
1887 goto out;
1888
1889 if (!net_eq(dev_net(dev), sock_net(sk)))
1890 goto out;
1891
1892 skb = skb_share_check(skb, GFP_ATOMIC);
1893 if (skb == NULL)
1894 goto oom;
1895
1896 /* drop any routing info */
1897 skb_dst_drop(skb);
1898
1899 /* drop conntrack reference */
1900 nf_reset_ct(skb);
1901
1902 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1903
1904 skb_push(skb, skb->data - skb_mac_header(skb));
1905
1906 /*
1907 * The SOCK_PACKET socket receives _all_ frames.
1908 */
1909
1910 spkt->spkt_family = dev->type;
1911 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1912 spkt->spkt_protocol = skb->protocol;
1913
1914 /*
1915 * Charge the memory to the socket. This is done specifically
1916 * to prevent sockets using all the memory up.
1917 */
1918
1919 if (sock_queue_rcv_skb(sk, skb) == 0)
1920 return 0;
1921
1922out:
1923 kfree_skb(skb);
1924oom:
1925 return 0;
1926}
1927
1928static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1929{
1930 int depth;
1931
1932 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1933 sock->type == SOCK_RAW) {
1934 skb_reset_mac_header(skb);
1935 skb->protocol = dev_parse_header_protocol(skb);
1936 }
1937
1938 /* Move network header to the right position for VLAN tagged packets */
1939 if (likely(skb->dev->type == ARPHRD_ETHER) &&
1940 eth_type_vlan(skb->protocol) &&
1941 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0)
1942 skb_set_network_header(skb, depth);
1943
1944 skb_probe_transport_header(skb);
1945}
1946
1947/*
1948 * Output a raw packet to a device layer. This bypasses all the other
1949 * protocol layers and you must therefore supply it with a complete frame
1950 */
1951
1952static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1953 size_t len)
1954{
1955 struct sock *sk = sock->sk;
1956 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1957 struct sk_buff *skb = NULL;
1958 struct net_device *dev;
1959 struct sockcm_cookie sockc;
1960 __be16 proto = 0;
1961 int err;
1962 int extra_len = 0;
1963
1964 /*
1965 * Get and verify the address.
1966 */
1967
1968 if (saddr) {
1969 if (msg->msg_namelen < sizeof(struct sockaddr))
1970 return -EINVAL;
1971 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1972 proto = saddr->spkt_protocol;
1973 } else
1974 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1975
1976 /*
1977 * Find the device first to size check it
1978 */
1979
1980 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1981retry:
1982 rcu_read_lock();
1983 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1984 err = -ENODEV;
1985 if (dev == NULL)
1986 goto out_unlock;
1987
1988 err = -ENETDOWN;
1989 if (!(dev->flags & IFF_UP))
1990 goto out_unlock;
1991
1992 /*
1993 * You may not queue a frame bigger than the mtu. This is the lowest level
1994 * raw protocol and you must do your own fragmentation at this level.
1995 */
1996
1997 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1998 if (!netif_supports_nofcs(dev)) {
1999 err = -EPROTONOSUPPORT;
2000 goto out_unlock;
2001 }
2002 extra_len = 4; /* We're doing our own CRC */
2003 }
2004
2005 err = -EMSGSIZE;
2006 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
2007 goto out_unlock;
2008
2009 if (!skb) {
2010 size_t reserved = LL_RESERVED_SPACE(dev);
2011 int tlen = dev->needed_tailroom;
2012 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
2013
2014 rcu_read_unlock();
2015 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
2016 if (skb == NULL)
2017 return -ENOBUFS;
2018 /* FIXME: Save some space for broken drivers that write a hard
2019 * header at transmission time by themselves. PPP is the notable
2020 * one here. This should really be fixed at the driver level.
2021 */
2022 skb_reserve(skb, reserved);
2023 skb_reset_network_header(skb);
2024
2025 /* Try to align data part correctly */
2026 if (hhlen) {
2027 skb->data -= hhlen;
2028 skb->tail -= hhlen;
2029 if (len < hhlen)
2030 skb_reset_network_header(skb);
2031 }
2032 err = memcpy_from_msg(skb_put(skb, len), msg, len);
2033 if (err)
2034 goto out_free;
2035 goto retry;
2036 }
2037
2038 if (!dev_validate_header(dev, skb->data, len) || !skb->len) {
2039 err = -EINVAL;
2040 goto out_unlock;
2041 }
2042 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
2043 !packet_extra_vlan_len_allowed(dev, skb)) {
2044 err = -EMSGSIZE;
2045 goto out_unlock;
2046 }
2047
2048 sockcm_init(&sockc, sk);
2049 if (msg->msg_controllen) {
2050 err = sock_cmsg_send(sk, msg, &sockc);
2051 if (unlikely(err))
2052 goto out_unlock;
2053 }
2054
2055 skb->protocol = proto;
2056 skb->dev = dev;
2057 skb->priority = READ_ONCE(sk->sk_priority);
2058 skb->mark = READ_ONCE(sk->sk_mark);
2059 skb->tstamp = sockc.transmit_time;
2060
2061 skb_setup_tx_timestamp(skb, sockc.tsflags);
2062
2063 if (unlikely(extra_len == 4))
2064 skb->no_fcs = 1;
2065
2066 packet_parse_headers(skb, sock);
2067
2068 dev_queue_xmit(skb);
2069 rcu_read_unlock();
2070 return len;
2071
2072out_unlock:
2073 rcu_read_unlock();
2074out_free:
2075 kfree_skb(skb);
2076 return err;
2077}
2078
2079static unsigned int run_filter(struct sk_buff *skb,
2080 const struct sock *sk,
2081 unsigned int res)
2082{
2083 struct sk_filter *filter;
2084
2085 rcu_read_lock();
2086 filter = rcu_dereference(sk->sk_filter);
2087 if (filter != NULL)
2088 res = bpf_prog_run_clear_cb(filter->prog, skb);
2089 rcu_read_unlock();
2090
2091 return res;
2092}
2093
2094static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2095 size_t *len, int vnet_hdr_sz)
2096{
2097 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 };
2098
2099 if (*len < vnet_hdr_sz)
2100 return -EINVAL;
2101 *len -= vnet_hdr_sz;
2102
2103 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0))
2104 return -EINVAL;
2105
2106 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz);
2107}
2108
2109/*
2110 * This function makes lazy skb cloning in hope that most of packets
2111 * are discarded by BPF.
2112 *
2113 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2114 * and skb->cb are mangled. It works because (and until) packets
2115 * falling here are owned by current CPU. Output packets are cloned
2116 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2117 * sequentially, so that if we return skb to original state on exit,
2118 * we will not harm anyone.
2119 */
2120
2121static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2122 struct packet_type *pt, struct net_device *orig_dev)
2123{
2124 enum skb_drop_reason drop_reason = SKB_CONSUMED;
2125 struct sock *sk;
2126 struct sockaddr_ll *sll;
2127 struct packet_sock *po;
2128 u8 *skb_head = skb->data;
2129 int skb_len = skb->len;
2130 unsigned int snaplen, res;
2131
2132 if (skb->pkt_type == PACKET_LOOPBACK)
2133 goto drop;
2134
2135 sk = pt->af_packet_priv;
2136 po = pkt_sk(sk);
2137
2138 if (!net_eq(dev_net(dev), sock_net(sk)))
2139 goto drop;
2140
2141 skb->dev = dev;
2142
2143 if (dev_has_header(dev)) {
2144 /* The device has an explicit notion of ll header,
2145 * exported to higher levels.
2146 *
2147 * Otherwise, the device hides details of its frame
2148 * structure, so that corresponding packet head is
2149 * never delivered to user.
2150 */
2151 if (sk->sk_type != SOCK_DGRAM)
2152 skb_push(skb, skb->data - skb_mac_header(skb));
2153 else if (skb->pkt_type == PACKET_OUTGOING) {
2154 /* Special case: outgoing packets have ll header at head */
2155 skb_pull(skb, skb_network_offset(skb));
2156 }
2157 }
2158
2159 snaplen = skb->len;
2160
2161 res = run_filter(skb, sk, snaplen);
2162 if (!res)
2163 goto drop_n_restore;
2164 if (snaplen > res)
2165 snaplen = res;
2166
2167 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2168 goto drop_n_acct;
2169
2170 if (skb_shared(skb)) {
2171 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2172 if (nskb == NULL)
2173 goto drop_n_acct;
2174
2175 if (skb_head != skb->data) {
2176 skb->data = skb_head;
2177 skb->len = skb_len;
2178 }
2179 consume_skb(skb);
2180 skb = nskb;
2181 }
2182
2183 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2184
2185 sll = &PACKET_SKB_CB(skb)->sa.ll;
2186 sll->sll_hatype = dev->type;
2187 sll->sll_pkttype = skb->pkt_type;
2188 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
2189 sll->sll_ifindex = orig_dev->ifindex;
2190 else
2191 sll->sll_ifindex = dev->ifindex;
2192
2193 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2194
2195 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2196 * Use their space for storing the original skb length.
2197 */
2198 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2199
2200 if (pskb_trim(skb, snaplen))
2201 goto drop_n_acct;
2202
2203 skb_set_owner_r(skb, sk);
2204 skb->dev = NULL;
2205 skb_dst_drop(skb);
2206
2207 /* drop conntrack reference */
2208 nf_reset_ct(skb);
2209
2210 spin_lock(&sk->sk_receive_queue.lock);
2211 po->stats.stats1.tp_packets++;
2212 sock_skb_set_dropcount(sk, skb);
2213 skb_clear_delivery_time(skb);
2214 __skb_queue_tail(&sk->sk_receive_queue, skb);
2215 spin_unlock(&sk->sk_receive_queue.lock);
2216 sk->sk_data_ready(sk);
2217 return 0;
2218
2219drop_n_acct:
2220 atomic_inc(&po->tp_drops);
2221 atomic_inc(&sk->sk_drops);
2222 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR;
2223
2224drop_n_restore:
2225 if (skb_head != skb->data && skb_shared(skb)) {
2226 skb->data = skb_head;
2227 skb->len = skb_len;
2228 }
2229drop:
2230 kfree_skb_reason(skb, drop_reason);
2231 return 0;
2232}
2233
2234static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2235 struct packet_type *pt, struct net_device *orig_dev)
2236{
2237 enum skb_drop_reason drop_reason = SKB_CONSUMED;
2238 struct sock *sk;
2239 struct packet_sock *po;
2240 struct sockaddr_ll *sll;
2241 union tpacket_uhdr h;
2242 u8 *skb_head = skb->data;
2243 int skb_len = skb->len;
2244 unsigned int snaplen, res;
2245 unsigned long status = TP_STATUS_USER;
2246 unsigned short macoff, hdrlen;
2247 unsigned int netoff;
2248 struct sk_buff *copy_skb = NULL;
2249 struct timespec64 ts;
2250 __u32 ts_status;
2251 unsigned int slot_id = 0;
2252 int vnet_hdr_sz = 0;
2253
2254 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2255 * We may add members to them until current aligned size without forcing
2256 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2257 */
2258 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2259 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2260
2261 if (skb->pkt_type == PACKET_LOOPBACK)
2262 goto drop;
2263
2264 sk = pt->af_packet_priv;
2265 po = pkt_sk(sk);
2266
2267 if (!net_eq(dev_net(dev), sock_net(sk)))
2268 goto drop;
2269
2270 if (dev_has_header(dev)) {
2271 if (sk->sk_type != SOCK_DGRAM)
2272 skb_push(skb, skb->data - skb_mac_header(skb));
2273 else if (skb->pkt_type == PACKET_OUTGOING) {
2274 /* Special case: outgoing packets have ll header at head */
2275 skb_pull(skb, skb_network_offset(skb));
2276 }
2277 }
2278
2279 snaplen = skb->len;
2280
2281 res = run_filter(skb, sk, snaplen);
2282 if (!res)
2283 goto drop_n_restore;
2284
2285 /* If we are flooded, just give up */
2286 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2287 atomic_inc(&po->tp_drops);
2288 goto drop_n_restore;
2289 }
2290
2291 if (skb->ip_summed == CHECKSUM_PARTIAL)
2292 status |= TP_STATUS_CSUMNOTREADY;
2293 else if (skb->pkt_type != PACKET_OUTGOING &&
2294 skb_csum_unnecessary(skb))
2295 status |= TP_STATUS_CSUM_VALID;
2296 if (skb_is_gso(skb) && skb_is_gso_tcp(skb))
2297 status |= TP_STATUS_GSO_TCP;
2298
2299 if (snaplen > res)
2300 snaplen = res;
2301
2302 if (sk->sk_type == SOCK_DGRAM) {
2303 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2304 po->tp_reserve;
2305 } else {
2306 unsigned int maclen = skb_network_offset(skb);
2307 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2308 (maclen < 16 ? 16 : maclen)) +
2309 po->tp_reserve;
2310 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2311 if (vnet_hdr_sz)
2312 netoff += vnet_hdr_sz;
2313 macoff = netoff - maclen;
2314 }
2315 if (netoff > USHRT_MAX) {
2316 atomic_inc(&po->tp_drops);
2317 goto drop_n_restore;
2318 }
2319 if (po->tp_version <= TPACKET_V2) {
2320 if (macoff + snaplen > po->rx_ring.frame_size) {
2321 if (po->copy_thresh &&
2322 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2323 if (skb_shared(skb)) {
2324 copy_skb = skb_clone(skb, GFP_ATOMIC);
2325 } else {
2326 copy_skb = skb_get(skb);
2327 skb_head = skb->data;
2328 }
2329 if (copy_skb) {
2330 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0,
2331 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll));
2332 skb_set_owner_r(copy_skb, sk);
2333 }
2334 }
2335 snaplen = po->rx_ring.frame_size - macoff;
2336 if ((int)snaplen < 0) {
2337 snaplen = 0;
2338 vnet_hdr_sz = 0;
2339 }
2340 }
2341 } else if (unlikely(macoff + snaplen >
2342 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2343 u32 nval;
2344
2345 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2346 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2347 snaplen, nval, macoff);
2348 snaplen = nval;
2349 if (unlikely((int)snaplen < 0)) {
2350 snaplen = 0;
2351 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2352 vnet_hdr_sz = 0;
2353 }
2354 }
2355 spin_lock(&sk->sk_receive_queue.lock);
2356 h.raw = packet_current_rx_frame(po, skb,
2357 TP_STATUS_KERNEL, (macoff+snaplen));
2358 if (!h.raw)
2359 goto drop_n_account;
2360
2361 if (po->tp_version <= TPACKET_V2) {
2362 slot_id = po->rx_ring.head;
2363 if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2364 goto drop_n_account;
2365 __set_bit(slot_id, po->rx_ring.rx_owner_map);
2366 }
2367
2368 if (vnet_hdr_sz &&
2369 virtio_net_hdr_from_skb(skb, h.raw + macoff -
2370 sizeof(struct virtio_net_hdr),
2371 vio_le(), true, 0)) {
2372 if (po->tp_version == TPACKET_V3)
2373 prb_clear_blk_fill_status(&po->rx_ring);
2374 goto drop_n_account;
2375 }
2376
2377 if (po->tp_version <= TPACKET_V2) {
2378 packet_increment_rx_head(po, &po->rx_ring);
2379 /*
2380 * LOSING will be reported till you read the stats,
2381 * because it's COR - Clear On Read.
2382 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2383 * at packet level.
2384 */
2385 if (atomic_read(&po->tp_drops))
2386 status |= TP_STATUS_LOSING;
2387 }
2388
2389 po->stats.stats1.tp_packets++;
2390 if (copy_skb) {
2391 status |= TP_STATUS_COPY;
2392 skb_clear_delivery_time(copy_skb);
2393 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2394 }
2395 spin_unlock(&sk->sk_receive_queue.lock);
2396
2397 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2398
2399 /* Always timestamp; prefer an existing software timestamp taken
2400 * closer to the time of capture.
2401 */
2402 ts_status = tpacket_get_timestamp(skb, &ts,
2403 READ_ONCE(po->tp_tstamp) |
2404 SOF_TIMESTAMPING_SOFTWARE);
2405 if (!ts_status)
2406 ktime_get_real_ts64(&ts);
2407
2408 status |= ts_status;
2409
2410 switch (po->tp_version) {
2411 case TPACKET_V1:
2412 h.h1->tp_len = skb->len;
2413 h.h1->tp_snaplen = snaplen;
2414 h.h1->tp_mac = macoff;
2415 h.h1->tp_net = netoff;
2416 h.h1->tp_sec = ts.tv_sec;
2417 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2418 hdrlen = sizeof(*h.h1);
2419 break;
2420 case TPACKET_V2:
2421 h.h2->tp_len = skb->len;
2422 h.h2->tp_snaplen = snaplen;
2423 h.h2->tp_mac = macoff;
2424 h.h2->tp_net = netoff;
2425 h.h2->tp_sec = ts.tv_sec;
2426 h.h2->tp_nsec = ts.tv_nsec;
2427 if (skb_vlan_tag_present(skb)) {
2428 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2429 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2430 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2431 } else {
2432 h.h2->tp_vlan_tci = 0;
2433 h.h2->tp_vlan_tpid = 0;
2434 }
2435 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2436 hdrlen = sizeof(*h.h2);
2437 break;
2438 case TPACKET_V3:
2439 /* tp_nxt_offset,vlan are already populated above.
2440 * So DONT clear those fields here
2441 */
2442 h.h3->tp_status |= status;
2443 h.h3->tp_len = skb->len;
2444 h.h3->tp_snaplen = snaplen;
2445 h.h3->tp_mac = macoff;
2446 h.h3->tp_net = netoff;
2447 h.h3->tp_sec = ts.tv_sec;
2448 h.h3->tp_nsec = ts.tv_nsec;
2449 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2450 hdrlen = sizeof(*h.h3);
2451 break;
2452 default:
2453 BUG();
2454 }
2455
2456 sll = h.raw + TPACKET_ALIGN(hdrlen);
2457 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2458 sll->sll_family = AF_PACKET;
2459 sll->sll_hatype = dev->type;
2460 sll->sll_protocol = skb->protocol;
2461 sll->sll_pkttype = skb->pkt_type;
2462 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
2463 sll->sll_ifindex = orig_dev->ifindex;
2464 else
2465 sll->sll_ifindex = dev->ifindex;
2466
2467 smp_mb();
2468
2469#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2470 if (po->tp_version <= TPACKET_V2) {
2471 u8 *start, *end;
2472
2473 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2474 macoff + snaplen);
2475
2476 for (start = h.raw; start < end; start += PAGE_SIZE)
2477 flush_dcache_page(pgv_to_page(start));
2478 }
2479 smp_wmb();
2480#endif
2481
2482 if (po->tp_version <= TPACKET_V2) {
2483 spin_lock(&sk->sk_receive_queue.lock);
2484 __packet_set_status(po, h.raw, status);
2485 __clear_bit(slot_id, po->rx_ring.rx_owner_map);
2486 spin_unlock(&sk->sk_receive_queue.lock);
2487 sk->sk_data_ready(sk);
2488 } else if (po->tp_version == TPACKET_V3) {
2489 prb_clear_blk_fill_status(&po->rx_ring);
2490 }
2491
2492drop_n_restore:
2493 if (skb_head != skb->data && skb_shared(skb)) {
2494 skb->data = skb_head;
2495 skb->len = skb_len;
2496 }
2497drop:
2498 kfree_skb_reason(skb, drop_reason);
2499 return 0;
2500
2501drop_n_account:
2502 spin_unlock(&sk->sk_receive_queue.lock);
2503 atomic_inc(&po->tp_drops);
2504 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR;
2505
2506 sk->sk_data_ready(sk);
2507 kfree_skb_reason(copy_skb, drop_reason);
2508 goto drop_n_restore;
2509}
2510
2511static void tpacket_destruct_skb(struct sk_buff *skb)
2512{
2513 struct packet_sock *po = pkt_sk(skb->sk);
2514
2515 if (likely(po->tx_ring.pg_vec)) {
2516 void *ph;
2517 __u32 ts;
2518
2519 ph = skb_zcopy_get_nouarg(skb);
2520 packet_dec_pending(&po->tx_ring);
2521
2522 ts = __packet_set_timestamp(po, ph, skb);
2523 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2524
2525 if (!packet_read_pending(&po->tx_ring))
2526 complete(&po->skb_completion);
2527 }
2528
2529 sock_wfree(skb);
2530}
2531
2532static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2533{
2534 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2535 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2536 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2537 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2538 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2539 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2540 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2541
2542 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2543 return -EINVAL;
2544
2545 return 0;
2546}
2547
2548static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2549 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz)
2550{
2551 int ret;
2552
2553 if (*len < vnet_hdr_sz)
2554 return -EINVAL;
2555 *len -= vnet_hdr_sz;
2556
2557 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2558 return -EFAULT;
2559
2560 ret = __packet_snd_vnet_parse(vnet_hdr, *len);
2561 if (ret)
2562 return ret;
2563
2564 /* move iter to point to the start of mac header */
2565 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr))
2566 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr));
2567
2568 return 0;
2569}
2570
2571static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2572 void *frame, struct net_device *dev, void *data, int tp_len,
2573 __be16 proto, unsigned char *addr, int hlen, int copylen,
2574 const struct sockcm_cookie *sockc)
2575{
2576 union tpacket_uhdr ph;
2577 int to_write, offset, len, nr_frags, len_max;
2578 struct socket *sock = po->sk.sk_socket;
2579 struct page *page;
2580 int err;
2581
2582 ph.raw = frame;
2583
2584 skb->protocol = proto;
2585 skb->dev = dev;
2586 skb->priority = READ_ONCE(po->sk.sk_priority);
2587 skb->mark = READ_ONCE(po->sk.sk_mark);
2588 skb->tstamp = sockc->transmit_time;
2589 skb_setup_tx_timestamp(skb, sockc->tsflags);
2590 skb_zcopy_set_nouarg(skb, ph.raw);
2591
2592 skb_reserve(skb, hlen);
2593 skb_reset_network_header(skb);
2594
2595 to_write = tp_len;
2596
2597 if (sock->type == SOCK_DGRAM) {
2598 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2599 NULL, tp_len);
2600 if (unlikely(err < 0))
2601 return -EINVAL;
2602 } else if (copylen) {
2603 int hdrlen = min_t(int, copylen, tp_len);
2604
2605 skb_push(skb, dev->hard_header_len);
2606 skb_put(skb, copylen - dev->hard_header_len);
2607 err = skb_store_bits(skb, 0, data, hdrlen);
2608 if (unlikely(err))
2609 return err;
2610 if (!dev_validate_header(dev, skb->data, hdrlen))
2611 return -EINVAL;
2612
2613 data += hdrlen;
2614 to_write -= hdrlen;
2615 }
2616
2617 offset = offset_in_page(data);
2618 len_max = PAGE_SIZE - offset;
2619 len = ((to_write > len_max) ? len_max : to_write);
2620
2621 skb->data_len = to_write;
2622 skb->len += to_write;
2623 skb->truesize += to_write;
2624 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2625
2626 while (likely(to_write)) {
2627 nr_frags = skb_shinfo(skb)->nr_frags;
2628
2629 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2630 pr_err("Packet exceed the number of skb frags(%u)\n",
2631 (unsigned int)MAX_SKB_FRAGS);
2632 return -EFAULT;
2633 }
2634
2635 page = pgv_to_page(data);
2636 data += len;
2637 flush_dcache_page(page);
2638 get_page(page);
2639 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2640 to_write -= len;
2641 offset = 0;
2642 len_max = PAGE_SIZE;
2643 len = ((to_write > len_max) ? len_max : to_write);
2644 }
2645
2646 packet_parse_headers(skb, sock);
2647
2648 return tp_len;
2649}
2650
2651static int tpacket_parse_header(struct packet_sock *po, void *frame,
2652 int size_max, void **data)
2653{
2654 union tpacket_uhdr ph;
2655 int tp_len, off;
2656
2657 ph.raw = frame;
2658
2659 switch (po->tp_version) {
2660 case TPACKET_V3:
2661 if (ph.h3->tp_next_offset != 0) {
2662 pr_warn_once("variable sized slot not supported");
2663 return -EINVAL;
2664 }
2665 tp_len = ph.h3->tp_len;
2666 break;
2667 case TPACKET_V2:
2668 tp_len = ph.h2->tp_len;
2669 break;
2670 default:
2671 tp_len = ph.h1->tp_len;
2672 break;
2673 }
2674 if (unlikely(tp_len > size_max)) {
2675 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2676 return -EMSGSIZE;
2677 }
2678
2679 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) {
2680 int off_min, off_max;
2681
2682 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2683 off_max = po->tx_ring.frame_size - tp_len;
2684 if (po->sk.sk_type == SOCK_DGRAM) {
2685 switch (po->tp_version) {
2686 case TPACKET_V3:
2687 off = ph.h3->tp_net;
2688 break;
2689 case TPACKET_V2:
2690 off = ph.h2->tp_net;
2691 break;
2692 default:
2693 off = ph.h1->tp_net;
2694 break;
2695 }
2696 } else {
2697 switch (po->tp_version) {
2698 case TPACKET_V3:
2699 off = ph.h3->tp_mac;
2700 break;
2701 case TPACKET_V2:
2702 off = ph.h2->tp_mac;
2703 break;
2704 default:
2705 off = ph.h1->tp_mac;
2706 break;
2707 }
2708 }
2709 if (unlikely((off < off_min) || (off_max < off)))
2710 return -EINVAL;
2711 } else {
2712 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2713 }
2714
2715 *data = frame + off;
2716 return tp_len;
2717}
2718
2719static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2720{
2721 struct sk_buff *skb = NULL;
2722 struct net_device *dev;
2723 struct virtio_net_hdr *vnet_hdr = NULL;
2724 struct sockcm_cookie sockc;
2725 __be16 proto;
2726 int err, reserve = 0;
2727 void *ph;
2728 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2729 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2730 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2731 unsigned char *addr = NULL;
2732 int tp_len, size_max;
2733 void *data;
2734 int len_sum = 0;
2735 int status = TP_STATUS_AVAILABLE;
2736 int hlen, tlen, copylen = 0;
2737 long timeo = 0;
2738
2739 mutex_lock(&po->pg_vec_lock);
2740
2741 /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2742 * we need to confirm it under protection of pg_vec_lock.
2743 */
2744 if (unlikely(!po->tx_ring.pg_vec)) {
2745 err = -EBUSY;
2746 goto out;
2747 }
2748 if (likely(saddr == NULL)) {
2749 dev = packet_cached_dev_get(po);
2750 proto = READ_ONCE(po->num);
2751 } else {
2752 err = -EINVAL;
2753 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2754 goto out;
2755 if (msg->msg_namelen < (saddr->sll_halen
2756 + offsetof(struct sockaddr_ll,
2757 sll_addr)))
2758 goto out;
2759 proto = saddr->sll_protocol;
2760 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2761 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2762 if (dev && msg->msg_namelen < dev->addr_len +
2763 offsetof(struct sockaddr_ll, sll_addr))
2764 goto out_put;
2765 addr = saddr->sll_addr;
2766 }
2767 }
2768
2769 err = -ENXIO;
2770 if (unlikely(dev == NULL))
2771 goto out;
2772 err = -ENETDOWN;
2773 if (unlikely(!(dev->flags & IFF_UP)))
2774 goto out_put;
2775
2776 sockcm_init(&sockc, &po->sk);
2777 if (msg->msg_controllen) {
2778 err = sock_cmsg_send(&po->sk, msg, &sockc);
2779 if (unlikely(err))
2780 goto out_put;
2781 }
2782
2783 if (po->sk.sk_socket->type == SOCK_RAW)
2784 reserve = dev->hard_header_len;
2785 size_max = po->tx_ring.frame_size
2786 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2787
2788 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz)
2789 size_max = dev->mtu + reserve + VLAN_HLEN;
2790
2791 reinit_completion(&po->skb_completion);
2792
2793 do {
2794 ph = packet_current_frame(po, &po->tx_ring,
2795 TP_STATUS_SEND_REQUEST);
2796 if (unlikely(ph == NULL)) {
2797 if (need_wait && skb) {
2798 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2799 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2800 if (timeo <= 0) {
2801 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2802 goto out_put;
2803 }
2804 }
2805 /* check for additional frames */
2806 continue;
2807 }
2808
2809 skb = NULL;
2810 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2811 if (tp_len < 0)
2812 goto tpacket_error;
2813
2814 status = TP_STATUS_SEND_REQUEST;
2815 hlen = LL_RESERVED_SPACE(dev);
2816 tlen = dev->needed_tailroom;
2817 if (vnet_hdr_sz) {
2818 vnet_hdr = data;
2819 data += vnet_hdr_sz;
2820 tp_len -= vnet_hdr_sz;
2821 if (tp_len < 0 ||
2822 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2823 tp_len = -EINVAL;
2824 goto tpacket_error;
2825 }
2826 copylen = __virtio16_to_cpu(vio_le(),
2827 vnet_hdr->hdr_len);
2828 }
2829 copylen = max_t(int, copylen, dev->hard_header_len);
2830 skb = sock_alloc_send_skb(&po->sk,
2831 hlen + tlen + sizeof(struct sockaddr_ll) +
2832 (copylen - dev->hard_header_len),
2833 !need_wait, &err);
2834
2835 if (unlikely(skb == NULL)) {
2836 /* we assume the socket was initially writeable ... */
2837 if (likely(len_sum > 0))
2838 err = len_sum;
2839 goto out_status;
2840 }
2841 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2842 addr, hlen, copylen, &sockc);
2843 if (likely(tp_len >= 0) &&
2844 tp_len > dev->mtu + reserve &&
2845 !vnet_hdr_sz &&
2846 !packet_extra_vlan_len_allowed(dev, skb))
2847 tp_len = -EMSGSIZE;
2848
2849 if (unlikely(tp_len < 0)) {
2850tpacket_error:
2851 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) {
2852 __packet_set_status(po, ph,
2853 TP_STATUS_AVAILABLE);
2854 packet_increment_head(&po->tx_ring);
2855 kfree_skb(skb);
2856 continue;
2857 } else {
2858 status = TP_STATUS_WRONG_FORMAT;
2859 err = tp_len;
2860 goto out_status;
2861 }
2862 }
2863
2864 if (vnet_hdr_sz) {
2865 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2866 tp_len = -EINVAL;
2867 goto tpacket_error;
2868 }
2869 virtio_net_hdr_set_proto(skb, vnet_hdr);
2870 }
2871
2872 skb->destructor = tpacket_destruct_skb;
2873 __packet_set_status(po, ph, TP_STATUS_SENDING);
2874 packet_inc_pending(&po->tx_ring);
2875
2876 status = TP_STATUS_SEND_REQUEST;
2877 err = packet_xmit(po, skb);
2878 if (unlikely(err != 0)) {
2879 if (err > 0)
2880 err = net_xmit_errno(err);
2881 if (err && __packet_get_status(po, ph) ==
2882 TP_STATUS_AVAILABLE) {
2883 /* skb was destructed already */
2884 skb = NULL;
2885 goto out_status;
2886 }
2887 /*
2888 * skb was dropped but not destructed yet;
2889 * let's treat it like congestion or err < 0
2890 */
2891 err = 0;
2892 }
2893 packet_increment_head(&po->tx_ring);
2894 len_sum += tp_len;
2895 } while (likely((ph != NULL) ||
2896 /* Note: packet_read_pending() might be slow if we have
2897 * to call it as it's per_cpu variable, but in fast-path
2898 * we already short-circuit the loop with the first
2899 * condition, and luckily don't have to go that path
2900 * anyway.
2901 */
2902 (need_wait && packet_read_pending(&po->tx_ring))));
2903
2904 err = len_sum;
2905 goto out_put;
2906
2907out_status:
2908 __packet_set_status(po, ph, status);
2909 kfree_skb(skb);
2910out_put:
2911 dev_put(dev);
2912out:
2913 mutex_unlock(&po->pg_vec_lock);
2914 return err;
2915}
2916
2917static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2918 size_t reserve, size_t len,
2919 size_t linear, int noblock,
2920 int *err)
2921{
2922 struct sk_buff *skb;
2923
2924 /* Under a page? Don't bother with paged skb. */
2925 if (prepad + len < PAGE_SIZE || !linear)
2926 linear = len;
2927
2928 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
2929 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER);
2930 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2931 err, PAGE_ALLOC_COSTLY_ORDER);
2932 if (!skb)
2933 return NULL;
2934
2935 skb_reserve(skb, reserve);
2936 skb_put(skb, linear);
2937 skb->data_len = len - linear;
2938 skb->len += len - linear;
2939
2940 return skb;
2941}
2942
2943static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2944{
2945 struct sock *sk = sock->sk;
2946 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2947 struct sk_buff *skb;
2948 struct net_device *dev;
2949 __be16 proto;
2950 unsigned char *addr = NULL;
2951 int err, reserve = 0;
2952 struct sockcm_cookie sockc;
2953 struct virtio_net_hdr vnet_hdr = { 0 };
2954 int offset = 0;
2955 struct packet_sock *po = pkt_sk(sk);
2956 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2957 int hlen, tlen, linear;
2958 int extra_len = 0;
2959
2960 /*
2961 * Get and verify the address.
2962 */
2963
2964 if (likely(saddr == NULL)) {
2965 dev = packet_cached_dev_get(po);
2966 proto = READ_ONCE(po->num);
2967 } else {
2968 err = -EINVAL;
2969 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2970 goto out;
2971 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2972 goto out;
2973 proto = saddr->sll_protocol;
2974 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2975 if (sock->type == SOCK_DGRAM) {
2976 if (dev && msg->msg_namelen < dev->addr_len +
2977 offsetof(struct sockaddr_ll, sll_addr))
2978 goto out_unlock;
2979 addr = saddr->sll_addr;
2980 }
2981 }
2982
2983 err = -ENXIO;
2984 if (unlikely(dev == NULL))
2985 goto out_unlock;
2986 err = -ENETDOWN;
2987 if (unlikely(!(dev->flags & IFF_UP)))
2988 goto out_unlock;
2989
2990 sockcm_init(&sockc, sk);
2991 sockc.mark = READ_ONCE(sk->sk_mark);
2992 if (msg->msg_controllen) {
2993 err = sock_cmsg_send(sk, msg, &sockc);
2994 if (unlikely(err))
2995 goto out_unlock;
2996 }
2997
2998 if (sock->type == SOCK_RAW)
2999 reserve = dev->hard_header_len;
3000 if (vnet_hdr_sz) {
3001 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz);
3002 if (err)
3003 goto out_unlock;
3004 }
3005
3006 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
3007 if (!netif_supports_nofcs(dev)) {
3008 err = -EPROTONOSUPPORT;
3009 goto out_unlock;
3010 }
3011 extra_len = 4; /* We're doing our own CRC */
3012 }
3013
3014 err = -EMSGSIZE;
3015 if (!vnet_hdr.gso_type &&
3016 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
3017 goto out_unlock;
3018
3019 err = -ENOBUFS;
3020 hlen = LL_RESERVED_SPACE(dev);
3021 tlen = dev->needed_tailroom;
3022 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
3023 linear = max(linear, min_t(int, len, dev->hard_header_len));
3024 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
3025 msg->msg_flags & MSG_DONTWAIT, &err);
3026 if (skb == NULL)
3027 goto out_unlock;
3028
3029 skb_reset_network_header(skb);
3030
3031 err = -EINVAL;
3032 if (sock->type == SOCK_DGRAM) {
3033 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
3034 if (unlikely(offset < 0))
3035 goto out_free;
3036 } else if (reserve) {
3037 skb_reserve(skb, -reserve);
3038 if (len < reserve + sizeof(struct ipv6hdr) &&
3039 dev->min_header_len != dev->hard_header_len)
3040 skb_reset_network_header(skb);
3041 }
3042
3043 /* Returns -EFAULT on error */
3044 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
3045 if (err)
3046 goto out_free;
3047
3048 if ((sock->type == SOCK_RAW &&
3049 !dev_validate_header(dev, skb->data, len)) || !skb->len) {
3050 err = -EINVAL;
3051 goto out_free;
3052 }
3053
3054 skb_setup_tx_timestamp(skb, sockc.tsflags);
3055
3056 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
3057 !packet_extra_vlan_len_allowed(dev, skb)) {
3058 err = -EMSGSIZE;
3059 goto out_free;
3060 }
3061
3062 skb->protocol = proto;
3063 skb->dev = dev;
3064 skb->priority = READ_ONCE(sk->sk_priority);
3065 skb->mark = sockc.mark;
3066 skb->tstamp = sockc.transmit_time;
3067
3068 if (unlikely(extra_len == 4))
3069 skb->no_fcs = 1;
3070
3071 packet_parse_headers(skb, sock);
3072
3073 if (vnet_hdr_sz) {
3074 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
3075 if (err)
3076 goto out_free;
3077 len += vnet_hdr_sz;
3078 virtio_net_hdr_set_proto(skb, &vnet_hdr);
3079 }
3080
3081 err = packet_xmit(po, skb);
3082
3083 if (unlikely(err != 0)) {
3084 if (err > 0)
3085 err = net_xmit_errno(err);
3086 if (err)
3087 goto out_unlock;
3088 }
3089
3090 dev_put(dev);
3091
3092 return len;
3093
3094out_free:
3095 kfree_skb(skb);
3096out_unlock:
3097 dev_put(dev);
3098out:
3099 return err;
3100}
3101
3102static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3103{
3104 struct sock *sk = sock->sk;
3105 struct packet_sock *po = pkt_sk(sk);
3106
3107 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
3108 * tpacket_snd() will redo the check safely.
3109 */
3110 if (data_race(po->tx_ring.pg_vec))
3111 return tpacket_snd(po, msg);
3112
3113 return packet_snd(sock, msg, len);
3114}
3115
3116/*
3117 * Close a PACKET socket. This is fairly simple. We immediately go
3118 * to 'closed' state and remove our protocol entry in the device list.
3119 */
3120
3121static int packet_release(struct socket *sock)
3122{
3123 struct sock *sk = sock->sk;
3124 struct packet_sock *po;
3125 struct packet_fanout *f;
3126 struct net *net;
3127 union tpacket_req_u req_u;
3128
3129 if (!sk)
3130 return 0;
3131
3132 net = sock_net(sk);
3133 po = pkt_sk(sk);
3134
3135 mutex_lock(&net->packet.sklist_lock);
3136 sk_del_node_init_rcu(sk);
3137 mutex_unlock(&net->packet.sklist_lock);
3138
3139 sock_prot_inuse_add(net, sk->sk_prot, -1);
3140
3141 spin_lock(&po->bind_lock);
3142 unregister_prot_hook(sk, false);
3143 packet_cached_dev_reset(po);
3144
3145 if (po->prot_hook.dev) {
3146 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3147 po->prot_hook.dev = NULL;
3148 }
3149 spin_unlock(&po->bind_lock);
3150
3151 packet_flush_mclist(sk);
3152
3153 lock_sock(sk);
3154 if (po->rx_ring.pg_vec) {
3155 memset(&req_u, 0, sizeof(req_u));
3156 packet_set_ring(sk, &req_u, 1, 0);
3157 }
3158
3159 if (po->tx_ring.pg_vec) {
3160 memset(&req_u, 0, sizeof(req_u));
3161 packet_set_ring(sk, &req_u, 1, 1);
3162 }
3163 release_sock(sk);
3164
3165 f = fanout_release(sk);
3166
3167 synchronize_net();
3168
3169 kfree(po->rollover);
3170 if (f) {
3171 fanout_release_data(f);
3172 kvfree(f);
3173 }
3174 /*
3175 * Now the socket is dead. No more input will appear.
3176 */
3177 sock_orphan(sk);
3178 sock->sk = NULL;
3179
3180 /* Purge queues */
3181
3182 skb_queue_purge(&sk->sk_receive_queue);
3183 packet_free_pending(po);
3184
3185 sock_put(sk);
3186 return 0;
3187}
3188
3189/*
3190 * Attach a packet hook.
3191 */
3192
3193static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3194 __be16 proto)
3195{
3196 struct packet_sock *po = pkt_sk(sk);
3197 struct net_device *dev = NULL;
3198 bool unlisted = false;
3199 bool need_rehook;
3200 int ret = 0;
3201
3202 lock_sock(sk);
3203 spin_lock(&po->bind_lock);
3204 if (!proto)
3205 proto = po->num;
3206
3207 rcu_read_lock();
3208
3209 if (po->fanout) {
3210 ret = -EINVAL;
3211 goto out_unlock;
3212 }
3213
3214 if (name) {
3215 dev = dev_get_by_name_rcu(sock_net(sk), name);
3216 if (!dev) {
3217 ret = -ENODEV;
3218 goto out_unlock;
3219 }
3220 } else if (ifindex) {
3221 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3222 if (!dev) {
3223 ret = -ENODEV;
3224 goto out_unlock;
3225 }
3226 }
3227
3228 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev;
3229
3230 if (need_rehook) {
3231 dev_hold(dev);
3232 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
3233 rcu_read_unlock();
3234 /* prevents packet_notifier() from calling
3235 * register_prot_hook()
3236 */
3237 WRITE_ONCE(po->num, 0);
3238 __unregister_prot_hook(sk, true);
3239 rcu_read_lock();
3240 if (dev)
3241 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3242 dev->ifindex);
3243 }
3244
3245 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING));
3246 WRITE_ONCE(po->num, proto);
3247 po->prot_hook.type = proto;
3248
3249 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3250
3251 if (unlikely(unlisted)) {
3252 po->prot_hook.dev = NULL;
3253 WRITE_ONCE(po->ifindex, -1);
3254 packet_cached_dev_reset(po);
3255 } else {
3256 netdev_hold(dev, &po->prot_hook.dev_tracker,
3257 GFP_ATOMIC);
3258 po->prot_hook.dev = dev;
3259 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
3260 packet_cached_dev_assign(po, dev);
3261 }
3262 dev_put(dev);
3263 }
3264
3265 if (proto == 0 || !need_rehook)
3266 goto out_unlock;
3267
3268 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3269 register_prot_hook(sk);
3270 } else {
3271 sk->sk_err = ENETDOWN;
3272 if (!sock_flag(sk, SOCK_DEAD))
3273 sk_error_report(sk);
3274 }
3275
3276out_unlock:
3277 rcu_read_unlock();
3278 spin_unlock(&po->bind_lock);
3279 release_sock(sk);
3280 return ret;
3281}
3282
3283/*
3284 * Bind a packet socket to a device
3285 */
3286
3287static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3288 int addr_len)
3289{
3290 struct sock *sk = sock->sk;
3291 char name[sizeof(uaddr->sa_data_min) + 1];
3292
3293 /*
3294 * Check legality
3295 */
3296
3297 if (addr_len != sizeof(struct sockaddr))
3298 return -EINVAL;
3299 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3300 * zero-terminated.
3301 */
3302 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min));
3303 name[sizeof(uaddr->sa_data_min)] = 0;
3304
3305 return packet_do_bind(sk, name, 0, 0);
3306}
3307
3308static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3309{
3310 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3311 struct sock *sk = sock->sk;
3312
3313 /*
3314 * Check legality
3315 */
3316
3317 if (addr_len < sizeof(struct sockaddr_ll))
3318 return -EINVAL;
3319 if (sll->sll_family != AF_PACKET)
3320 return -EINVAL;
3321
3322 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol);
3323}
3324
3325static struct proto packet_proto = {
3326 .name = "PACKET",
3327 .owner = THIS_MODULE,
3328 .obj_size = sizeof(struct packet_sock),
3329};
3330
3331/*
3332 * Create a packet of type SOCK_PACKET.
3333 */
3334
3335static int packet_create(struct net *net, struct socket *sock, int protocol,
3336 int kern)
3337{
3338 struct sock *sk;
3339 struct packet_sock *po;
3340 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3341 int err;
3342
3343 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3344 return -EPERM;
3345 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3346 sock->type != SOCK_PACKET)
3347 return -ESOCKTNOSUPPORT;
3348
3349 sock->state = SS_UNCONNECTED;
3350
3351 err = -ENOBUFS;
3352 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3353 if (sk == NULL)
3354 goto out;
3355
3356 sock->ops = &packet_ops;
3357 if (sock->type == SOCK_PACKET)
3358 sock->ops = &packet_ops_spkt;
3359
3360 sock_init_data(sock, sk);
3361
3362 po = pkt_sk(sk);
3363 init_completion(&po->skb_completion);
3364 sk->sk_family = PF_PACKET;
3365 po->num = proto;
3366
3367 err = packet_alloc_pending(po);
3368 if (err)
3369 goto out2;
3370
3371 packet_cached_dev_reset(po);
3372
3373 sk->sk_destruct = packet_sock_destruct;
3374
3375 /*
3376 * Attach a protocol block
3377 */
3378
3379 spin_lock_init(&po->bind_lock);
3380 mutex_init(&po->pg_vec_lock);
3381 po->rollover = NULL;
3382 po->prot_hook.func = packet_rcv;
3383
3384 if (sock->type == SOCK_PACKET)
3385 po->prot_hook.func = packet_rcv_spkt;
3386
3387 po->prot_hook.af_packet_priv = sk;
3388 po->prot_hook.af_packet_net = sock_net(sk);
3389
3390 if (proto) {
3391 po->prot_hook.type = proto;
3392 __register_prot_hook(sk);
3393 }
3394
3395 mutex_lock(&net->packet.sklist_lock);
3396 sk_add_node_tail_rcu(sk, &net->packet.sklist);
3397 mutex_unlock(&net->packet.sklist_lock);
3398
3399 sock_prot_inuse_add(net, &packet_proto, 1);
3400
3401 return 0;
3402out2:
3403 sk_free(sk);
3404out:
3405 return err;
3406}
3407
3408/*
3409 * Pull a packet from our receive queue and hand it to the user.
3410 * If necessary we block.
3411 */
3412
3413static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3414 int flags)
3415{
3416 struct sock *sk = sock->sk;
3417 struct sk_buff *skb;
3418 int copied, err;
3419 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz);
3420 unsigned int origlen = 0;
3421
3422 err = -EINVAL;
3423 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3424 goto out;
3425
3426#if 0
3427 /* What error should we return now? EUNATTACH? */
3428 if (pkt_sk(sk)->ifindex < 0)
3429 return -ENODEV;
3430#endif
3431
3432 if (flags & MSG_ERRQUEUE) {
3433 err = sock_recv_errqueue(sk, msg, len,
3434 SOL_PACKET, PACKET_TX_TIMESTAMP);
3435 goto out;
3436 }
3437
3438 /*
3439 * Call the generic datagram receiver. This handles all sorts
3440 * of horrible races and re-entrancy so we can forget about it
3441 * in the protocol layers.
3442 *
3443 * Now it will return ENETDOWN, if device have just gone down,
3444 * but then it will block.
3445 */
3446
3447 skb = skb_recv_datagram(sk, flags, &err);
3448
3449 /*
3450 * An error occurred so return it. Because skb_recv_datagram()
3451 * handles the blocking we don't see and worry about blocking
3452 * retries.
3453 */
3454
3455 if (skb == NULL)
3456 goto out;
3457
3458 packet_rcv_try_clear_pressure(pkt_sk(sk));
3459
3460 if (vnet_hdr_len) {
3461 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len);
3462 if (err)
3463 goto out_free;
3464 }
3465
3466 /* You lose any data beyond the buffer you gave. If it worries
3467 * a user program they can ask the device for its MTU
3468 * anyway.
3469 */
3470 copied = skb->len;
3471 if (copied > len) {
3472 copied = len;
3473 msg->msg_flags |= MSG_TRUNC;
3474 }
3475
3476 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3477 if (err)
3478 goto out_free;
3479
3480 if (sock->type != SOCK_PACKET) {
3481 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3482
3483 /* Original length was stored in sockaddr_ll fields */
3484 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3485 sll->sll_family = AF_PACKET;
3486 sll->sll_protocol = skb->protocol;
3487 }
3488
3489 sock_recv_cmsgs(msg, sk, skb);
3490
3491 if (msg->msg_name) {
3492 const size_t max_len = min(sizeof(skb->cb),
3493 sizeof(struct sockaddr_storage));
3494 int copy_len;
3495
3496 /* If the address length field is there to be filled
3497 * in, we fill it in now.
3498 */
3499 if (sock->type == SOCK_PACKET) {
3500 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3501 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3502 copy_len = msg->msg_namelen;
3503 } else {
3504 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3505
3506 msg->msg_namelen = sll->sll_halen +
3507 offsetof(struct sockaddr_ll, sll_addr);
3508 copy_len = msg->msg_namelen;
3509 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3510 memset(msg->msg_name +
3511 offsetof(struct sockaddr_ll, sll_addr),
3512 0, sizeof(sll->sll_addr));
3513 msg->msg_namelen = sizeof(struct sockaddr_ll);
3514 }
3515 }
3516 if (WARN_ON_ONCE(copy_len > max_len)) {
3517 copy_len = max_len;
3518 msg->msg_namelen = copy_len;
3519 }
3520 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3521 }
3522
3523 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) {
3524 struct tpacket_auxdata aux;
3525
3526 aux.tp_status = TP_STATUS_USER;
3527 if (skb->ip_summed == CHECKSUM_PARTIAL)
3528 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3529 else if (skb->pkt_type != PACKET_OUTGOING &&
3530 skb_csum_unnecessary(skb))
3531 aux.tp_status |= TP_STATUS_CSUM_VALID;
3532 if (skb_is_gso(skb) && skb_is_gso_tcp(skb))
3533 aux.tp_status |= TP_STATUS_GSO_TCP;
3534
3535 aux.tp_len = origlen;
3536 aux.tp_snaplen = skb->len;
3537 aux.tp_mac = 0;
3538 aux.tp_net = skb_network_offset(skb);
3539 if (skb_vlan_tag_present(skb)) {
3540 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3541 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3542 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3543 } else {
3544 aux.tp_vlan_tci = 0;
3545 aux.tp_vlan_tpid = 0;
3546 }
3547 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3548 }
3549
3550 /*
3551 * Free or return the buffer as appropriate. Again this
3552 * hides all the races and re-entrancy issues from us.
3553 */
3554 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3555
3556out_free:
3557 skb_free_datagram(sk, skb);
3558out:
3559 return err;
3560}
3561
3562static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3563 int peer)
3564{
3565 struct net_device *dev;
3566 struct sock *sk = sock->sk;
3567
3568 if (peer)
3569 return -EOPNOTSUPP;
3570
3571 uaddr->sa_family = AF_PACKET;
3572 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min));
3573 rcu_read_lock();
3574 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
3575 if (dev)
3576 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min));
3577 rcu_read_unlock();
3578
3579 return sizeof(*uaddr);
3580}
3581
3582static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3583 int peer)
3584{
3585 struct net_device *dev;
3586 struct sock *sk = sock->sk;
3587 struct packet_sock *po = pkt_sk(sk);
3588 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3589 int ifindex;
3590
3591 if (peer)
3592 return -EOPNOTSUPP;
3593
3594 ifindex = READ_ONCE(po->ifindex);
3595 sll->sll_family = AF_PACKET;
3596 sll->sll_ifindex = ifindex;
3597 sll->sll_protocol = READ_ONCE(po->num);
3598 sll->sll_pkttype = 0;
3599 rcu_read_lock();
3600 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3601 if (dev) {
3602 sll->sll_hatype = dev->type;
3603 sll->sll_halen = dev->addr_len;
3604
3605 /* Let __fortify_memcpy_chk() know the actual buffer size. */
3606 memcpy(((struct sockaddr_storage *)sll)->__data +
3607 offsetof(struct sockaddr_ll, sll_addr) -
3608 offsetofend(struct sockaddr_ll, sll_family),
3609 dev->dev_addr, dev->addr_len);
3610 } else {
3611 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3612 sll->sll_halen = 0;
3613 }
3614 rcu_read_unlock();
3615
3616 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3617}
3618
3619static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3620 int what)
3621{
3622 switch (i->type) {
3623 case PACKET_MR_MULTICAST:
3624 if (i->alen != dev->addr_len)
3625 return -EINVAL;
3626 if (what > 0)
3627 return dev_mc_add(dev, i->addr);
3628 else
3629 return dev_mc_del(dev, i->addr);
3630 break;
3631 case PACKET_MR_PROMISC:
3632 return dev_set_promiscuity(dev, what);
3633 case PACKET_MR_ALLMULTI:
3634 return dev_set_allmulti(dev, what);
3635 case PACKET_MR_UNICAST:
3636 if (i->alen != dev->addr_len)
3637 return -EINVAL;
3638 if (what > 0)
3639 return dev_uc_add(dev, i->addr);
3640 else
3641 return dev_uc_del(dev, i->addr);
3642 break;
3643 default:
3644 break;
3645 }
3646 return 0;
3647}
3648
3649static void packet_dev_mclist_delete(struct net_device *dev,
3650 struct packet_mclist **mlp)
3651{
3652 struct packet_mclist *ml;
3653
3654 while ((ml = *mlp) != NULL) {
3655 if (ml->ifindex == dev->ifindex) {
3656 packet_dev_mc(dev, ml, -1);
3657 *mlp = ml->next;
3658 kfree(ml);
3659 } else
3660 mlp = &ml->next;
3661 }
3662}
3663
3664static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3665{
3666 struct packet_sock *po = pkt_sk(sk);
3667 struct packet_mclist *ml, *i;
3668 struct net_device *dev;
3669 int err;
3670
3671 rtnl_lock();
3672
3673 err = -ENODEV;
3674 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3675 if (!dev)
3676 goto done;
3677
3678 err = -EINVAL;
3679 if (mreq->mr_alen > dev->addr_len)
3680 goto done;
3681
3682 err = -ENOBUFS;
3683 i = kmalloc(sizeof(*i), GFP_KERNEL);
3684 if (i == NULL)
3685 goto done;
3686
3687 err = 0;
3688 for (ml = po->mclist; ml; ml = ml->next) {
3689 if (ml->ifindex == mreq->mr_ifindex &&
3690 ml->type == mreq->mr_type &&
3691 ml->alen == mreq->mr_alen &&
3692 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3693 ml->count++;
3694 /* Free the new element ... */
3695 kfree(i);
3696 goto done;
3697 }
3698 }
3699
3700 i->type = mreq->mr_type;
3701 i->ifindex = mreq->mr_ifindex;
3702 i->alen = mreq->mr_alen;
3703 memcpy(i->addr, mreq->mr_address, i->alen);
3704 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3705 i->count = 1;
3706 i->next = po->mclist;
3707 po->mclist = i;
3708 err = packet_dev_mc(dev, i, 1);
3709 if (err) {
3710 po->mclist = i->next;
3711 kfree(i);
3712 }
3713
3714done:
3715 rtnl_unlock();
3716 return err;
3717}
3718
3719static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3720{
3721 struct packet_mclist *ml, **mlp;
3722
3723 rtnl_lock();
3724
3725 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3726 if (ml->ifindex == mreq->mr_ifindex &&
3727 ml->type == mreq->mr_type &&
3728 ml->alen == mreq->mr_alen &&
3729 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3730 if (--ml->count == 0) {
3731 struct net_device *dev;
3732 *mlp = ml->next;
3733 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3734 if (dev)
3735 packet_dev_mc(dev, ml, -1);
3736 kfree(ml);
3737 }
3738 break;
3739 }
3740 }
3741 rtnl_unlock();
3742 return 0;
3743}
3744
3745static void packet_flush_mclist(struct sock *sk)
3746{
3747 struct packet_sock *po = pkt_sk(sk);
3748 struct packet_mclist *ml;
3749
3750 if (!po->mclist)
3751 return;
3752
3753 rtnl_lock();
3754 while ((ml = po->mclist) != NULL) {
3755 struct net_device *dev;
3756
3757 po->mclist = ml->next;
3758 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3759 if (dev != NULL)
3760 packet_dev_mc(dev, ml, -1);
3761 kfree(ml);
3762 }
3763 rtnl_unlock();
3764}
3765
3766static int
3767packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3768 unsigned int optlen)
3769{
3770 struct sock *sk = sock->sk;
3771 struct packet_sock *po = pkt_sk(sk);
3772 int ret;
3773
3774 if (level != SOL_PACKET)
3775 return -ENOPROTOOPT;
3776
3777 switch (optname) {
3778 case PACKET_ADD_MEMBERSHIP:
3779 case PACKET_DROP_MEMBERSHIP:
3780 {
3781 struct packet_mreq_max mreq;
3782 int len = optlen;
3783 memset(&mreq, 0, sizeof(mreq));
3784 if (len < sizeof(struct packet_mreq))
3785 return -EINVAL;
3786 if (len > sizeof(mreq))
3787 len = sizeof(mreq);
3788 if (copy_from_sockptr(&mreq, optval, len))
3789 return -EFAULT;
3790 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3791 return -EINVAL;
3792 if (optname == PACKET_ADD_MEMBERSHIP)
3793 ret = packet_mc_add(sk, &mreq);
3794 else
3795 ret = packet_mc_drop(sk, &mreq);
3796 return ret;
3797 }
3798
3799 case PACKET_RX_RING:
3800 case PACKET_TX_RING:
3801 {
3802 union tpacket_req_u req_u;
3803 int len;
3804
3805 lock_sock(sk);
3806 switch (po->tp_version) {
3807 case TPACKET_V1:
3808 case TPACKET_V2:
3809 len = sizeof(req_u.req);
3810 break;
3811 case TPACKET_V3:
3812 default:
3813 len = sizeof(req_u.req3);
3814 break;
3815 }
3816 if (optlen < len) {
3817 ret = -EINVAL;
3818 } else {
3819 if (copy_from_sockptr(&req_u.req, optval, len))
3820 ret = -EFAULT;
3821 else
3822 ret = packet_set_ring(sk, &req_u, 0,
3823 optname == PACKET_TX_RING);
3824 }
3825 release_sock(sk);
3826 return ret;
3827 }
3828 case PACKET_COPY_THRESH:
3829 {
3830 int val;
3831
3832 if (optlen != sizeof(val))
3833 return -EINVAL;
3834 if (copy_from_sockptr(&val, optval, sizeof(val)))
3835 return -EFAULT;
3836
3837 pkt_sk(sk)->copy_thresh = val;
3838 return 0;
3839 }
3840 case PACKET_VERSION:
3841 {
3842 int val;
3843
3844 if (optlen != sizeof(val))
3845 return -EINVAL;
3846 if (copy_from_sockptr(&val, optval, sizeof(val)))
3847 return -EFAULT;
3848 switch (val) {
3849 case TPACKET_V1:
3850 case TPACKET_V2:
3851 case TPACKET_V3:
3852 break;
3853 default:
3854 return -EINVAL;
3855 }
3856 lock_sock(sk);
3857 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3858 ret = -EBUSY;
3859 } else {
3860 po->tp_version = val;
3861 ret = 0;
3862 }
3863 release_sock(sk);
3864 return ret;
3865 }
3866 case PACKET_RESERVE:
3867 {
3868 unsigned int val;
3869
3870 if (optlen != sizeof(val))
3871 return -EINVAL;
3872 if (copy_from_sockptr(&val, optval, sizeof(val)))
3873 return -EFAULT;
3874 if (val > INT_MAX)
3875 return -EINVAL;
3876 lock_sock(sk);
3877 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3878 ret = -EBUSY;
3879 } else {
3880 po->tp_reserve = val;
3881 ret = 0;
3882 }
3883 release_sock(sk);
3884 return ret;
3885 }
3886 case PACKET_LOSS:
3887 {
3888 unsigned int val;
3889
3890 if (optlen != sizeof(val))
3891 return -EINVAL;
3892 if (copy_from_sockptr(&val, optval, sizeof(val)))
3893 return -EFAULT;
3894
3895 lock_sock(sk);
3896 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3897 ret = -EBUSY;
3898 } else {
3899 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val);
3900 ret = 0;
3901 }
3902 release_sock(sk);
3903 return ret;
3904 }
3905 case PACKET_AUXDATA:
3906 {
3907 int val;
3908
3909 if (optlen < sizeof(val))
3910 return -EINVAL;
3911 if (copy_from_sockptr(&val, optval, sizeof(val)))
3912 return -EFAULT;
3913
3914 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val);
3915 return 0;
3916 }
3917 case PACKET_ORIGDEV:
3918 {
3919 int val;
3920
3921 if (optlen < sizeof(val))
3922 return -EINVAL;
3923 if (copy_from_sockptr(&val, optval, sizeof(val)))
3924 return -EFAULT;
3925
3926 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val);
3927 return 0;
3928 }
3929 case PACKET_VNET_HDR:
3930 case PACKET_VNET_HDR_SZ:
3931 {
3932 int val, hdr_len;
3933
3934 if (sock->type != SOCK_RAW)
3935 return -EINVAL;
3936 if (optlen < sizeof(val))
3937 return -EINVAL;
3938 if (copy_from_sockptr(&val, optval, sizeof(val)))
3939 return -EFAULT;
3940
3941 if (optname == PACKET_VNET_HDR_SZ) {
3942 if (val && val != sizeof(struct virtio_net_hdr) &&
3943 val != sizeof(struct virtio_net_hdr_mrg_rxbuf))
3944 return -EINVAL;
3945 hdr_len = val;
3946 } else {
3947 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0;
3948 }
3949 lock_sock(sk);
3950 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3951 ret = -EBUSY;
3952 } else {
3953 WRITE_ONCE(po->vnet_hdr_sz, hdr_len);
3954 ret = 0;
3955 }
3956 release_sock(sk);
3957 return ret;
3958 }
3959 case PACKET_TIMESTAMP:
3960 {
3961 int val;
3962
3963 if (optlen != sizeof(val))
3964 return -EINVAL;
3965 if (copy_from_sockptr(&val, optval, sizeof(val)))
3966 return -EFAULT;
3967
3968 WRITE_ONCE(po->tp_tstamp, val);
3969 return 0;
3970 }
3971 case PACKET_FANOUT:
3972 {
3973 struct fanout_args args = { 0 };
3974
3975 if (optlen != sizeof(int) && optlen != sizeof(args))
3976 return -EINVAL;
3977 if (copy_from_sockptr(&args, optval, optlen))
3978 return -EFAULT;
3979
3980 return fanout_add(sk, &args);
3981 }
3982 case PACKET_FANOUT_DATA:
3983 {
3984 /* Paired with the WRITE_ONCE() in fanout_add() */
3985 if (!READ_ONCE(po->fanout))
3986 return -EINVAL;
3987
3988 return fanout_set_data(po, optval, optlen);
3989 }
3990 case PACKET_IGNORE_OUTGOING:
3991 {
3992 int val;
3993
3994 if (optlen != sizeof(val))
3995 return -EINVAL;
3996 if (copy_from_sockptr(&val, optval, sizeof(val)))
3997 return -EFAULT;
3998 if (val < 0 || val > 1)
3999 return -EINVAL;
4000
4001 po->prot_hook.ignore_outgoing = !!val;
4002 return 0;
4003 }
4004 case PACKET_TX_HAS_OFF:
4005 {
4006 unsigned int val;
4007
4008 if (optlen != sizeof(val))
4009 return -EINVAL;
4010 if (copy_from_sockptr(&val, optval, sizeof(val)))
4011 return -EFAULT;
4012
4013 lock_sock(sk);
4014 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec)
4015 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val);
4016
4017 release_sock(sk);
4018 return 0;
4019 }
4020 case PACKET_QDISC_BYPASS:
4021 {
4022 int val;
4023
4024 if (optlen != sizeof(val))
4025 return -EINVAL;
4026 if (copy_from_sockptr(&val, optval, sizeof(val)))
4027 return -EFAULT;
4028
4029 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val);
4030 return 0;
4031 }
4032 default:
4033 return -ENOPROTOOPT;
4034 }
4035}
4036
4037static int packet_getsockopt(struct socket *sock, int level, int optname,
4038 char __user *optval, int __user *optlen)
4039{
4040 int len;
4041 int val, lv = sizeof(val);
4042 struct sock *sk = sock->sk;
4043 struct packet_sock *po = pkt_sk(sk);
4044 void *data = &val;
4045 union tpacket_stats_u st;
4046 struct tpacket_rollover_stats rstats;
4047 int drops;
4048
4049 if (level != SOL_PACKET)
4050 return -ENOPROTOOPT;
4051
4052 if (get_user(len, optlen))
4053 return -EFAULT;
4054
4055 if (len < 0)
4056 return -EINVAL;
4057
4058 switch (optname) {
4059 case PACKET_STATISTICS:
4060 spin_lock_bh(&sk->sk_receive_queue.lock);
4061 memcpy(&st, &po->stats, sizeof(st));
4062 memset(&po->stats, 0, sizeof(po->stats));
4063 spin_unlock_bh(&sk->sk_receive_queue.lock);
4064 drops = atomic_xchg(&po->tp_drops, 0);
4065
4066 if (po->tp_version == TPACKET_V3) {
4067 lv = sizeof(struct tpacket_stats_v3);
4068 st.stats3.tp_drops = drops;
4069 st.stats3.tp_packets += drops;
4070 data = &st.stats3;
4071 } else {
4072 lv = sizeof(struct tpacket_stats);
4073 st.stats1.tp_drops = drops;
4074 st.stats1.tp_packets += drops;
4075 data = &st.stats1;
4076 }
4077
4078 break;
4079 case PACKET_AUXDATA:
4080 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA);
4081 break;
4082 case PACKET_ORIGDEV:
4083 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV);
4084 break;
4085 case PACKET_VNET_HDR:
4086 val = !!READ_ONCE(po->vnet_hdr_sz);
4087 break;
4088 case PACKET_VNET_HDR_SZ:
4089 val = READ_ONCE(po->vnet_hdr_sz);
4090 break;
4091 case PACKET_VERSION:
4092 val = po->tp_version;
4093 break;
4094 case PACKET_HDRLEN:
4095 if (len > sizeof(int))
4096 len = sizeof(int);
4097 if (len < sizeof(int))
4098 return -EINVAL;
4099 if (copy_from_user(&val, optval, len))
4100 return -EFAULT;
4101 switch (val) {
4102 case TPACKET_V1:
4103 val = sizeof(struct tpacket_hdr);
4104 break;
4105 case TPACKET_V2:
4106 val = sizeof(struct tpacket2_hdr);
4107 break;
4108 case TPACKET_V3:
4109 val = sizeof(struct tpacket3_hdr);
4110 break;
4111 default:
4112 return -EINVAL;
4113 }
4114 break;
4115 case PACKET_RESERVE:
4116 val = po->tp_reserve;
4117 break;
4118 case PACKET_LOSS:
4119 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS);
4120 break;
4121 case PACKET_TIMESTAMP:
4122 val = READ_ONCE(po->tp_tstamp);
4123 break;
4124 case PACKET_FANOUT:
4125 val = (po->fanout ?
4126 ((u32)po->fanout->id |
4127 ((u32)po->fanout->type << 16) |
4128 ((u32)po->fanout->flags << 24)) :
4129 0);
4130 break;
4131 case PACKET_IGNORE_OUTGOING:
4132 val = po->prot_hook.ignore_outgoing;
4133 break;
4134 case PACKET_ROLLOVER_STATS:
4135 if (!po->rollover)
4136 return -EINVAL;
4137 rstats.tp_all = atomic_long_read(&po->rollover->num);
4138 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4139 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4140 data = &rstats;
4141 lv = sizeof(rstats);
4142 break;
4143 case PACKET_TX_HAS_OFF:
4144 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF);
4145 break;
4146 case PACKET_QDISC_BYPASS:
4147 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS);
4148 break;
4149 default:
4150 return -ENOPROTOOPT;
4151 }
4152
4153 if (len > lv)
4154 len = lv;
4155 if (put_user(len, optlen))
4156 return -EFAULT;
4157 if (copy_to_user(optval, data, len))
4158 return -EFAULT;
4159 return 0;
4160}
4161
4162static int packet_notifier(struct notifier_block *this,
4163 unsigned long msg, void *ptr)
4164{
4165 struct sock *sk;
4166 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4167 struct net *net = dev_net(dev);
4168
4169 rcu_read_lock();
4170 sk_for_each_rcu(sk, &net->packet.sklist) {
4171 struct packet_sock *po = pkt_sk(sk);
4172
4173 switch (msg) {
4174 case NETDEV_UNREGISTER:
4175 if (po->mclist)
4176 packet_dev_mclist_delete(dev, &po->mclist);
4177 fallthrough;
4178
4179 case NETDEV_DOWN:
4180 if (dev->ifindex == po->ifindex) {
4181 spin_lock(&po->bind_lock);
4182 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
4183 __unregister_prot_hook(sk, false);
4184 sk->sk_err = ENETDOWN;
4185 if (!sock_flag(sk, SOCK_DEAD))
4186 sk_error_report(sk);
4187 }
4188 if (msg == NETDEV_UNREGISTER) {
4189 packet_cached_dev_reset(po);
4190 WRITE_ONCE(po->ifindex, -1);
4191 netdev_put(po->prot_hook.dev,
4192 &po->prot_hook.dev_tracker);
4193 po->prot_hook.dev = NULL;
4194 }
4195 spin_unlock(&po->bind_lock);
4196 }
4197 break;
4198 case NETDEV_UP:
4199 if (dev->ifindex == po->ifindex) {
4200 spin_lock(&po->bind_lock);
4201 if (po->num)
4202 register_prot_hook(sk);
4203 spin_unlock(&po->bind_lock);
4204 }
4205 break;
4206 }
4207 }
4208 rcu_read_unlock();
4209 return NOTIFY_DONE;
4210}
4211
4212
4213static int packet_ioctl(struct socket *sock, unsigned int cmd,
4214 unsigned long arg)
4215{
4216 struct sock *sk = sock->sk;
4217
4218 switch (cmd) {
4219 case SIOCOUTQ:
4220 {
4221 int amount = sk_wmem_alloc_get(sk);
4222
4223 return put_user(amount, (int __user *)arg);
4224 }
4225 case SIOCINQ:
4226 {
4227 struct sk_buff *skb;
4228 int amount = 0;
4229
4230 spin_lock_bh(&sk->sk_receive_queue.lock);
4231 skb = skb_peek(&sk->sk_receive_queue);
4232 if (skb)
4233 amount = skb->len;
4234 spin_unlock_bh(&sk->sk_receive_queue.lock);
4235 return put_user(amount, (int __user *)arg);
4236 }
4237#ifdef CONFIG_INET
4238 case SIOCADDRT:
4239 case SIOCDELRT:
4240 case SIOCDARP:
4241 case SIOCGARP:
4242 case SIOCSARP:
4243 case SIOCGIFADDR:
4244 case SIOCSIFADDR:
4245 case SIOCGIFBRDADDR:
4246 case SIOCSIFBRDADDR:
4247 case SIOCGIFNETMASK:
4248 case SIOCSIFNETMASK:
4249 case SIOCGIFDSTADDR:
4250 case SIOCSIFDSTADDR:
4251 case SIOCSIFFLAGS:
4252 return inet_dgram_ops.ioctl(sock, cmd, arg);
4253#endif
4254
4255 default:
4256 return -ENOIOCTLCMD;
4257 }
4258 return 0;
4259}
4260
4261static __poll_t packet_poll(struct file *file, struct socket *sock,
4262 poll_table *wait)
4263{
4264 struct sock *sk = sock->sk;
4265 struct packet_sock *po = pkt_sk(sk);
4266 __poll_t mask = datagram_poll(file, sock, wait);
4267
4268 spin_lock_bh(&sk->sk_receive_queue.lock);
4269 if (po->rx_ring.pg_vec) {
4270 if (!packet_previous_rx_frame(po, &po->rx_ring,
4271 TP_STATUS_KERNEL))
4272 mask |= EPOLLIN | EPOLLRDNORM;
4273 }
4274 packet_rcv_try_clear_pressure(po);
4275 spin_unlock_bh(&sk->sk_receive_queue.lock);
4276 spin_lock_bh(&sk->sk_write_queue.lock);
4277 if (po->tx_ring.pg_vec) {
4278 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4279 mask |= EPOLLOUT | EPOLLWRNORM;
4280 }
4281 spin_unlock_bh(&sk->sk_write_queue.lock);
4282 return mask;
4283}
4284
4285
4286/* Dirty? Well, I still did not learn better way to account
4287 * for user mmaps.
4288 */
4289
4290static void packet_mm_open(struct vm_area_struct *vma)
4291{
4292 struct file *file = vma->vm_file;
4293 struct socket *sock = file->private_data;
4294 struct sock *sk = sock->sk;
4295
4296 if (sk)
4297 atomic_long_inc(&pkt_sk(sk)->mapped);
4298}
4299
4300static void packet_mm_close(struct vm_area_struct *vma)
4301{
4302 struct file *file = vma->vm_file;
4303 struct socket *sock = file->private_data;
4304 struct sock *sk = sock->sk;
4305
4306 if (sk)
4307 atomic_long_dec(&pkt_sk(sk)->mapped);
4308}
4309
4310static const struct vm_operations_struct packet_mmap_ops = {
4311 .open = packet_mm_open,
4312 .close = packet_mm_close,
4313};
4314
4315static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4316 unsigned int len)
4317{
4318 int i;
4319
4320 for (i = 0; i < len; i++) {
4321 if (likely(pg_vec[i].buffer)) {
4322 if (is_vmalloc_addr(pg_vec[i].buffer))
4323 vfree(pg_vec[i].buffer);
4324 else
4325 free_pages((unsigned long)pg_vec[i].buffer,
4326 order);
4327 pg_vec[i].buffer = NULL;
4328 }
4329 }
4330 kfree(pg_vec);
4331}
4332
4333static char *alloc_one_pg_vec_page(unsigned long order)
4334{
4335 char *buffer;
4336 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4337 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4338
4339 buffer = (char *) __get_free_pages(gfp_flags, order);
4340 if (buffer)
4341 return buffer;
4342
4343 /* __get_free_pages failed, fall back to vmalloc */
4344 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4345 if (buffer)
4346 return buffer;
4347
4348 /* vmalloc failed, lets dig into swap here */
4349 gfp_flags &= ~__GFP_NORETRY;
4350 buffer = (char *) __get_free_pages(gfp_flags, order);
4351 if (buffer)
4352 return buffer;
4353
4354 /* complete and utter failure */
4355 return NULL;
4356}
4357
4358static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4359{
4360 unsigned int block_nr = req->tp_block_nr;
4361 struct pgv *pg_vec;
4362 int i;
4363
4364 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4365 if (unlikely(!pg_vec))
4366 goto out;
4367
4368 for (i = 0; i < block_nr; i++) {
4369 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4370 if (unlikely(!pg_vec[i].buffer))
4371 goto out_free_pgvec;
4372 }
4373
4374out:
4375 return pg_vec;
4376
4377out_free_pgvec:
4378 free_pg_vec(pg_vec, order, block_nr);
4379 pg_vec = NULL;
4380 goto out;
4381}
4382
4383static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4384 int closing, int tx_ring)
4385{
4386 struct pgv *pg_vec = NULL;
4387 struct packet_sock *po = pkt_sk(sk);
4388 unsigned long *rx_owner_map = NULL;
4389 int was_running, order = 0;
4390 struct packet_ring_buffer *rb;
4391 struct sk_buff_head *rb_queue;
4392 __be16 num;
4393 int err;
4394 /* Added to avoid minimal code churn */
4395 struct tpacket_req *req = &req_u->req;
4396
4397 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4398 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4399
4400 err = -EBUSY;
4401 if (!closing) {
4402 if (atomic_long_read(&po->mapped))
4403 goto out;
4404 if (packet_read_pending(rb))
4405 goto out;
4406 }
4407
4408 if (req->tp_block_nr) {
4409 unsigned int min_frame_size;
4410
4411 /* Sanity tests and some calculations */
4412 err = -EBUSY;
4413 if (unlikely(rb->pg_vec))
4414 goto out;
4415
4416 switch (po->tp_version) {
4417 case TPACKET_V1:
4418 po->tp_hdrlen = TPACKET_HDRLEN;
4419 break;
4420 case TPACKET_V2:
4421 po->tp_hdrlen = TPACKET2_HDRLEN;
4422 break;
4423 case TPACKET_V3:
4424 po->tp_hdrlen = TPACKET3_HDRLEN;
4425 break;
4426 }
4427
4428 err = -EINVAL;
4429 if (unlikely((int)req->tp_block_size <= 0))
4430 goto out;
4431 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4432 goto out;
4433 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4434 if (po->tp_version >= TPACKET_V3 &&
4435 req->tp_block_size <
4436 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4437 goto out;
4438 if (unlikely(req->tp_frame_size < min_frame_size))
4439 goto out;
4440 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4441 goto out;
4442
4443 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4444 if (unlikely(rb->frames_per_block == 0))
4445 goto out;
4446 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4447 goto out;
4448 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4449 req->tp_frame_nr))
4450 goto out;
4451
4452 err = -ENOMEM;
4453 order = get_order(req->tp_block_size);
4454 pg_vec = alloc_pg_vec(req, order);
4455 if (unlikely(!pg_vec))
4456 goto out;
4457 switch (po->tp_version) {
4458 case TPACKET_V3:
4459 /* Block transmit is not supported yet */
4460 if (!tx_ring) {
4461 init_prb_bdqc(po, rb, pg_vec, req_u);
4462 } else {
4463 struct tpacket_req3 *req3 = &req_u->req3;
4464
4465 if (req3->tp_retire_blk_tov ||
4466 req3->tp_sizeof_priv ||
4467 req3->tp_feature_req_word) {
4468 err = -EINVAL;
4469 goto out_free_pg_vec;
4470 }
4471 }
4472 break;
4473 default:
4474 if (!tx_ring) {
4475 rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4476 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4477 if (!rx_owner_map)
4478 goto out_free_pg_vec;
4479 }
4480 break;
4481 }
4482 }
4483 /* Done */
4484 else {
4485 err = -EINVAL;
4486 if (unlikely(req->tp_frame_nr))
4487 goto out;
4488 }
4489
4490
4491 /* Detach socket from network */
4492 spin_lock(&po->bind_lock);
4493 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING);
4494 num = po->num;
4495 if (was_running) {
4496 WRITE_ONCE(po->num, 0);
4497 __unregister_prot_hook(sk, false);
4498 }
4499 spin_unlock(&po->bind_lock);
4500
4501 synchronize_net();
4502
4503 err = -EBUSY;
4504 mutex_lock(&po->pg_vec_lock);
4505 if (closing || atomic_long_read(&po->mapped) == 0) {
4506 err = 0;
4507 spin_lock_bh(&rb_queue->lock);
4508 swap(rb->pg_vec, pg_vec);
4509 if (po->tp_version <= TPACKET_V2)
4510 swap(rb->rx_owner_map, rx_owner_map);
4511 rb->frame_max = (req->tp_frame_nr - 1);
4512 rb->head = 0;
4513 rb->frame_size = req->tp_frame_size;
4514 spin_unlock_bh(&rb_queue->lock);
4515
4516 swap(rb->pg_vec_order, order);
4517 swap(rb->pg_vec_len, req->tp_block_nr);
4518
4519 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4520 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4521 tpacket_rcv : packet_rcv;
4522 skb_queue_purge(rb_queue);
4523 if (atomic_long_read(&po->mapped))
4524 pr_err("packet_mmap: vma is busy: %ld\n",
4525 atomic_long_read(&po->mapped));
4526 }
4527 mutex_unlock(&po->pg_vec_lock);
4528
4529 spin_lock(&po->bind_lock);
4530 if (was_running) {
4531 WRITE_ONCE(po->num, num);
4532 register_prot_hook(sk);
4533 }
4534 spin_unlock(&po->bind_lock);
4535 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4536 /* Because we don't support block-based V3 on tx-ring */
4537 if (!tx_ring)
4538 prb_shutdown_retire_blk_timer(po, rb_queue);
4539 }
4540
4541out_free_pg_vec:
4542 if (pg_vec) {
4543 bitmap_free(rx_owner_map);
4544 free_pg_vec(pg_vec, order, req->tp_block_nr);
4545 }
4546out:
4547 return err;
4548}
4549
4550static int packet_mmap(struct file *file, struct socket *sock,
4551 struct vm_area_struct *vma)
4552{
4553 struct sock *sk = sock->sk;
4554 struct packet_sock *po = pkt_sk(sk);
4555 unsigned long size, expected_size;
4556 struct packet_ring_buffer *rb;
4557 unsigned long start;
4558 int err = -EINVAL;
4559 int i;
4560
4561 if (vma->vm_pgoff)
4562 return -EINVAL;
4563
4564 mutex_lock(&po->pg_vec_lock);
4565
4566 expected_size = 0;
4567 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4568 if (rb->pg_vec) {
4569 expected_size += rb->pg_vec_len
4570 * rb->pg_vec_pages
4571 * PAGE_SIZE;
4572 }
4573 }
4574
4575 if (expected_size == 0)
4576 goto out;
4577
4578 size = vma->vm_end - vma->vm_start;
4579 if (size != expected_size)
4580 goto out;
4581
4582 start = vma->vm_start;
4583 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4584 if (rb->pg_vec == NULL)
4585 continue;
4586
4587 for (i = 0; i < rb->pg_vec_len; i++) {
4588 struct page *page;
4589 void *kaddr = rb->pg_vec[i].buffer;
4590 int pg_num;
4591
4592 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4593 page = pgv_to_page(kaddr);
4594 err = vm_insert_page(vma, start, page);
4595 if (unlikely(err))
4596 goto out;
4597 start += PAGE_SIZE;
4598 kaddr += PAGE_SIZE;
4599 }
4600 }
4601 }
4602
4603 atomic_long_inc(&po->mapped);
4604 vma->vm_ops = &packet_mmap_ops;
4605 err = 0;
4606
4607out:
4608 mutex_unlock(&po->pg_vec_lock);
4609 return err;
4610}
4611
4612static const struct proto_ops packet_ops_spkt = {
4613 .family = PF_PACKET,
4614 .owner = THIS_MODULE,
4615 .release = packet_release,
4616 .bind = packet_bind_spkt,
4617 .connect = sock_no_connect,
4618 .socketpair = sock_no_socketpair,
4619 .accept = sock_no_accept,
4620 .getname = packet_getname_spkt,
4621 .poll = datagram_poll,
4622 .ioctl = packet_ioctl,
4623 .gettstamp = sock_gettstamp,
4624 .listen = sock_no_listen,
4625 .shutdown = sock_no_shutdown,
4626 .sendmsg = packet_sendmsg_spkt,
4627 .recvmsg = packet_recvmsg,
4628 .mmap = sock_no_mmap,
4629};
4630
4631static const struct proto_ops packet_ops = {
4632 .family = PF_PACKET,
4633 .owner = THIS_MODULE,
4634 .release = packet_release,
4635 .bind = packet_bind,
4636 .connect = sock_no_connect,
4637 .socketpair = sock_no_socketpair,
4638 .accept = sock_no_accept,
4639 .getname = packet_getname,
4640 .poll = packet_poll,
4641 .ioctl = packet_ioctl,
4642 .gettstamp = sock_gettstamp,
4643 .listen = sock_no_listen,
4644 .shutdown = sock_no_shutdown,
4645 .setsockopt = packet_setsockopt,
4646 .getsockopt = packet_getsockopt,
4647 .sendmsg = packet_sendmsg,
4648 .recvmsg = packet_recvmsg,
4649 .mmap = packet_mmap,
4650};
4651
4652static const struct net_proto_family packet_family_ops = {
4653 .family = PF_PACKET,
4654 .create = packet_create,
4655 .owner = THIS_MODULE,
4656};
4657
4658static struct notifier_block packet_netdev_notifier = {
4659 .notifier_call = packet_notifier,
4660};
4661
4662#ifdef CONFIG_PROC_FS
4663
4664static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4665 __acquires(RCU)
4666{
4667 struct net *net = seq_file_net(seq);
4668
4669 rcu_read_lock();
4670 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4671}
4672
4673static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4674{
4675 struct net *net = seq_file_net(seq);
4676 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4677}
4678
4679static void packet_seq_stop(struct seq_file *seq, void *v)
4680 __releases(RCU)
4681{
4682 rcu_read_unlock();
4683}
4684
4685static int packet_seq_show(struct seq_file *seq, void *v)
4686{
4687 if (v == SEQ_START_TOKEN)
4688 seq_printf(seq,
4689 "%*sRefCnt Type Proto Iface R Rmem User Inode\n",
4690 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk");
4691 else {
4692 struct sock *s = sk_entry(v);
4693 const struct packet_sock *po = pkt_sk(s);
4694
4695 seq_printf(seq,
4696 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4697 s,
4698 refcount_read(&s->sk_refcnt),
4699 s->sk_type,
4700 ntohs(READ_ONCE(po->num)),
4701 READ_ONCE(po->ifindex),
4702 packet_sock_flag(po, PACKET_SOCK_RUNNING),
4703 atomic_read(&s->sk_rmem_alloc),
4704 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4705 sock_i_ino(s));
4706 }
4707
4708 return 0;
4709}
4710
4711static const struct seq_operations packet_seq_ops = {
4712 .start = packet_seq_start,
4713 .next = packet_seq_next,
4714 .stop = packet_seq_stop,
4715 .show = packet_seq_show,
4716};
4717#endif
4718
4719static int __net_init packet_net_init(struct net *net)
4720{
4721 mutex_init(&net->packet.sklist_lock);
4722 INIT_HLIST_HEAD(&net->packet.sklist);
4723
4724#ifdef CONFIG_PROC_FS
4725 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4726 sizeof(struct seq_net_private)))
4727 return -ENOMEM;
4728#endif /* CONFIG_PROC_FS */
4729
4730 return 0;
4731}
4732
4733static void __net_exit packet_net_exit(struct net *net)
4734{
4735 remove_proc_entry("packet", net->proc_net);
4736 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4737}
4738
4739static struct pernet_operations packet_net_ops = {
4740 .init = packet_net_init,
4741 .exit = packet_net_exit,
4742};
4743
4744
4745static void __exit packet_exit(void)
4746{
4747 sock_unregister(PF_PACKET);
4748 proto_unregister(&packet_proto);
4749 unregister_netdevice_notifier(&packet_netdev_notifier);
4750 unregister_pernet_subsys(&packet_net_ops);
4751}
4752
4753static int __init packet_init(void)
4754{
4755 int rc;
4756
4757 rc = register_pernet_subsys(&packet_net_ops);
4758 if (rc)
4759 goto out;
4760 rc = register_netdevice_notifier(&packet_netdev_notifier);
4761 if (rc)
4762 goto out_pernet;
4763 rc = proto_register(&packet_proto, 0);
4764 if (rc)
4765 goto out_notifier;
4766 rc = sock_register(&packet_family_ops);
4767 if (rc)
4768 goto out_proto;
4769
4770 return 0;
4771
4772out_proto:
4773 proto_unregister(&packet_proto);
4774out_notifier:
4775 unregister_netdevice_notifier(&packet_netdev_notifier);
4776out_pernet:
4777 unregister_pernet_subsys(&packet_net_ops);
4778out:
4779 return rc;
4780}
4781
4782module_init(packet_init);
4783module_exit(packet_exit);
4784MODULE_DESCRIPTION("Packet socket support (AF_PACKET)");
4785MODULE_LICENSE("GPL");
4786MODULE_ALIAS_NETPROTO(PF_PACKET);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * PACKET - implements raw packet sockets.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 *
13 * Fixes:
14 * Alan Cox : verify_area() now used correctly
15 * Alan Cox : new skbuff lists, look ma no backlogs!
16 * Alan Cox : tidied skbuff lists.
17 * Alan Cox : Now uses generic datagram routines I
18 * added. Also fixed the peek/read crash
19 * from all old Linux datagram code.
20 * Alan Cox : Uses the improved datagram code.
21 * Alan Cox : Added NULL's for socket options.
22 * Alan Cox : Re-commented the code.
23 * Alan Cox : Use new kernel side addressing
24 * Rob Janssen : Correct MTU usage.
25 * Dave Platt : Counter leaks caused by incorrect
26 * interrupt locking and some slightly
27 * dubious gcc output. Can you read
28 * compiler: it said _VOLATILE_
29 * Richard Kooijman : Timestamp fixes.
30 * Alan Cox : New buffers. Use sk->mac.raw.
31 * Alan Cox : sendmsg/recvmsg support.
32 * Alan Cox : Protocol setting support
33 * Alexey Kuznetsov : Untied from IPv4 stack.
34 * Cyrus Durgin : Fixed kerneld for kmod.
35 * Michal Ostrowski : Module initialization cleanup.
36 * Ulises Alonso : Frame number limit removal and
37 * packet_set_ring memory leak.
38 * Eric Biederman : Allow for > 8 byte hardware addresses.
39 * The convention is that longer addresses
40 * will simply extend the hardware address
41 * byte arrays at the end of sockaddr_ll
42 * and packet_mreq.
43 * Johann Baudy : Added TX RING.
44 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * layer.
46 * Copyright (C) 2011, <lokec@ccs.neu.edu>
47 */
48
49#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50
51#include <linux/ethtool.h>
52#include <linux/filter.h>
53#include <linux/types.h>
54#include <linux/mm.h>
55#include <linux/capability.h>
56#include <linux/fcntl.h>
57#include <linux/socket.h>
58#include <linux/in.h>
59#include <linux/inet.h>
60#include <linux/netdevice.h>
61#include <linux/if_packet.h>
62#include <linux/wireless.h>
63#include <linux/kernel.h>
64#include <linux/kmod.h>
65#include <linux/slab.h>
66#include <linux/vmalloc.h>
67#include <net/net_namespace.h>
68#include <net/ip.h>
69#include <net/protocol.h>
70#include <linux/skbuff.h>
71#include <net/sock.h>
72#include <linux/errno.h>
73#include <linux/timer.h>
74#include <linux/uaccess.h>
75#include <asm/ioctls.h>
76#include <asm/page.h>
77#include <asm/cacheflush.h>
78#include <asm/io.h>
79#include <linux/proc_fs.h>
80#include <linux/seq_file.h>
81#include <linux/poll.h>
82#include <linux/module.h>
83#include <linux/init.h>
84#include <linux/mutex.h>
85#include <linux/if_vlan.h>
86#include <linux/virtio_net.h>
87#include <linux/errqueue.h>
88#include <linux/net_tstamp.h>
89#include <linux/percpu.h>
90#ifdef CONFIG_INET
91#include <net/inet_common.h>
92#endif
93#include <linux/bpf.h>
94#include <net/compat.h>
95#include <linux/netfilter_netdev.h>
96
97#include "internal.h"
98
99/*
100 Assumptions:
101 - If the device has no dev->header_ops->create, there is no LL header
102 visible above the device. In this case, its hard_header_len should be 0.
103 The device may prepend its own header internally. In this case, its
104 needed_headroom should be set to the space needed for it to add its
105 internal header.
106 For example, a WiFi driver pretending to be an Ethernet driver should
107 set its hard_header_len to be the Ethernet header length, and set its
108 needed_headroom to be (the real WiFi header length - the fake Ethernet
109 header length).
110 - packet socket receives packets with pulled ll header,
111 so that SOCK_RAW should push it back.
112
113On receive:
114-----------
115
116Incoming, dev_has_header(dev) == true
117 mac_header -> ll header
118 data -> data
119
120Outgoing, dev_has_header(dev) == true
121 mac_header -> ll header
122 data -> ll header
123
124Incoming, dev_has_header(dev) == false
125 mac_header -> data
126 However drivers often make it point to the ll header.
127 This is incorrect because the ll header should be invisible to us.
128 data -> data
129
130Outgoing, dev_has_header(dev) == false
131 mac_header -> data. ll header is invisible to us.
132 data -> data
133
134Resume
135 If dev_has_header(dev) == false we are unable to restore the ll header,
136 because it is invisible to us.
137
138
139On transmit:
140------------
141
142dev_has_header(dev) == true
143 mac_header -> ll header
144 data -> ll header
145
146dev_has_header(dev) == false (ll header is invisible to us)
147 mac_header -> data
148 data -> data
149
150 We should set network_header on output to the correct position,
151 packet classifier depends on it.
152 */
153
154/* Private packet socket structures. */
155
156/* identical to struct packet_mreq except it has
157 * a longer address field.
158 */
159struct packet_mreq_max {
160 int mr_ifindex;
161 unsigned short mr_type;
162 unsigned short mr_alen;
163 unsigned char mr_address[MAX_ADDR_LEN];
164};
165
166union tpacket_uhdr {
167 struct tpacket_hdr *h1;
168 struct tpacket2_hdr *h2;
169 struct tpacket3_hdr *h3;
170 void *raw;
171};
172
173static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
174 int closing, int tx_ring);
175
176#define V3_ALIGNMENT (8)
177
178#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
179
180#define BLK_PLUS_PRIV(sz_of_priv) \
181 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
182
183#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
184#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
185#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
186#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
187#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
188#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
189
190struct packet_sock;
191static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
192 struct packet_type *pt, struct net_device *orig_dev);
193
194static void *packet_previous_frame(struct packet_sock *po,
195 struct packet_ring_buffer *rb,
196 int status);
197static void packet_increment_head(struct packet_ring_buffer *buff);
198static int prb_curr_blk_in_use(struct tpacket_block_desc *);
199static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 struct packet_sock *);
201static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 struct packet_sock *, unsigned int status);
203static int prb_queue_frozen(struct tpacket_kbdq_core *);
204static void prb_open_block(struct tpacket_kbdq_core *,
205 struct tpacket_block_desc *);
206static void prb_retire_rx_blk_timer_expired(struct timer_list *);
207static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
209static void prb_clear_rxhash(struct tpacket_kbdq_core *,
210 struct tpacket3_hdr *);
211static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
212 struct tpacket3_hdr *);
213static void packet_flush_mclist(struct sock *sk);
214static u16 packet_pick_tx_queue(struct sk_buff *skb);
215
216struct packet_skb_cb {
217 union {
218 struct sockaddr_pkt pkt;
219 union {
220 /* Trick: alias skb original length with
221 * ll.sll_family and ll.protocol in order
222 * to save room.
223 */
224 unsigned int origlen;
225 struct sockaddr_ll ll;
226 };
227 } sa;
228};
229
230#define vio_le() virtio_legacy_is_little_endian()
231
232#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
233
234#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
235#define GET_PBLOCK_DESC(x, bid) \
236 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
237#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
238 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
239#define GET_NEXT_PRB_BLK_NUM(x) \
240 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
241 ((x)->kactive_blk_num+1) : 0)
242
243static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
244static void __fanout_link(struct sock *sk, struct packet_sock *po);
245
246#ifdef CONFIG_NETFILTER_EGRESS
247static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb)
248{
249 struct sk_buff *next, *head = NULL, *tail;
250 int rc;
251
252 rcu_read_lock();
253 for (; skb != NULL; skb = next) {
254 next = skb->next;
255 skb_mark_not_on_list(skb);
256
257 if (!nf_hook_egress(skb, &rc, skb->dev))
258 continue;
259
260 if (!head)
261 head = skb;
262 else
263 tail->next = skb;
264
265 tail = skb;
266 }
267 rcu_read_unlock();
268
269 return head;
270}
271#endif
272
273static int packet_xmit(const struct packet_sock *po, struct sk_buff *skb)
274{
275 if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS))
276 return dev_queue_xmit(skb);
277
278#ifdef CONFIG_NETFILTER_EGRESS
279 if (nf_hook_egress_active()) {
280 skb = nf_hook_direct_egress(skb);
281 if (!skb)
282 return NET_XMIT_DROP;
283 }
284#endif
285 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
286}
287
288static struct net_device *packet_cached_dev_get(struct packet_sock *po)
289{
290 struct net_device *dev;
291
292 rcu_read_lock();
293 dev = rcu_dereference(po->cached_dev);
294 dev_hold(dev);
295 rcu_read_unlock();
296
297 return dev;
298}
299
300static void packet_cached_dev_assign(struct packet_sock *po,
301 struct net_device *dev)
302{
303 rcu_assign_pointer(po->cached_dev, dev);
304}
305
306static void packet_cached_dev_reset(struct packet_sock *po)
307{
308 RCU_INIT_POINTER(po->cached_dev, NULL);
309}
310
311static u16 packet_pick_tx_queue(struct sk_buff *skb)
312{
313 struct net_device *dev = skb->dev;
314 const struct net_device_ops *ops = dev->netdev_ops;
315 int cpu = raw_smp_processor_id();
316 u16 queue_index;
317
318#ifdef CONFIG_XPS
319 skb->sender_cpu = cpu + 1;
320#endif
321 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
322 if (ops->ndo_select_queue) {
323 queue_index = ops->ndo_select_queue(dev, skb, NULL);
324 queue_index = netdev_cap_txqueue(dev, queue_index);
325 } else {
326 queue_index = netdev_pick_tx(dev, skb, NULL);
327 }
328
329 return queue_index;
330}
331
332/* __register_prot_hook must be invoked through register_prot_hook
333 * or from a context in which asynchronous accesses to the packet
334 * socket is not possible (packet_create()).
335 */
336static void __register_prot_hook(struct sock *sk)
337{
338 struct packet_sock *po = pkt_sk(sk);
339
340 if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
341 if (po->fanout)
342 __fanout_link(sk, po);
343 else
344 dev_add_pack(&po->prot_hook);
345
346 sock_hold(sk);
347 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1);
348 }
349}
350
351static void register_prot_hook(struct sock *sk)
352{
353 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
354 __register_prot_hook(sk);
355}
356
357/* If the sync parameter is true, we will temporarily drop
358 * the po->bind_lock and do a synchronize_net to make sure no
359 * asynchronous packet processing paths still refer to the elements
360 * of po->prot_hook. If the sync parameter is false, it is the
361 * callers responsibility to take care of this.
362 */
363static void __unregister_prot_hook(struct sock *sk, bool sync)
364{
365 struct packet_sock *po = pkt_sk(sk);
366
367 lockdep_assert_held_once(&po->bind_lock);
368
369 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0);
370
371 if (po->fanout)
372 __fanout_unlink(sk, po);
373 else
374 __dev_remove_pack(&po->prot_hook);
375
376 __sock_put(sk);
377
378 if (sync) {
379 spin_unlock(&po->bind_lock);
380 synchronize_net();
381 spin_lock(&po->bind_lock);
382 }
383}
384
385static void unregister_prot_hook(struct sock *sk, bool sync)
386{
387 struct packet_sock *po = pkt_sk(sk);
388
389 if (packet_sock_flag(po, PACKET_SOCK_RUNNING))
390 __unregister_prot_hook(sk, sync);
391}
392
393static inline struct page * __pure pgv_to_page(void *addr)
394{
395 if (is_vmalloc_addr(addr))
396 return vmalloc_to_page(addr);
397 return virt_to_page(addr);
398}
399
400static void __packet_set_status(struct packet_sock *po, void *frame, int status)
401{
402 union tpacket_uhdr h;
403
404 /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */
405
406 h.raw = frame;
407 switch (po->tp_version) {
408 case TPACKET_V1:
409 WRITE_ONCE(h.h1->tp_status, status);
410 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
411 break;
412 case TPACKET_V2:
413 WRITE_ONCE(h.h2->tp_status, status);
414 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
415 break;
416 case TPACKET_V3:
417 WRITE_ONCE(h.h3->tp_status, status);
418 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
419 break;
420 default:
421 WARN(1, "TPACKET version not supported.\n");
422 BUG();
423 }
424
425 smp_wmb();
426}
427
428static int __packet_get_status(const struct packet_sock *po, void *frame)
429{
430 union tpacket_uhdr h;
431
432 smp_rmb();
433
434 /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */
435
436 h.raw = frame;
437 switch (po->tp_version) {
438 case TPACKET_V1:
439 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
440 return READ_ONCE(h.h1->tp_status);
441 case TPACKET_V2:
442 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
443 return READ_ONCE(h.h2->tp_status);
444 case TPACKET_V3:
445 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
446 return READ_ONCE(h.h3->tp_status);
447 default:
448 WARN(1, "TPACKET version not supported.\n");
449 BUG();
450 return 0;
451 }
452}
453
454static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
455 unsigned int flags)
456{
457 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
458
459 if (shhwtstamps &&
460 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
461 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
462 return TP_STATUS_TS_RAW_HARDWARE;
463
464 if ((flags & SOF_TIMESTAMPING_SOFTWARE) &&
465 ktime_to_timespec64_cond(skb_tstamp(skb), ts))
466 return TP_STATUS_TS_SOFTWARE;
467
468 return 0;
469}
470
471static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
472 struct sk_buff *skb)
473{
474 union tpacket_uhdr h;
475 struct timespec64 ts;
476 __u32 ts_status;
477
478 if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp))))
479 return 0;
480
481 h.raw = frame;
482 /*
483 * versions 1 through 3 overflow the timestamps in y2106, since they
484 * all store the seconds in a 32-bit unsigned integer.
485 * If we create a version 4, that should have a 64-bit timestamp,
486 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
487 * nanoseconds.
488 */
489 switch (po->tp_version) {
490 case TPACKET_V1:
491 h.h1->tp_sec = ts.tv_sec;
492 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
493 break;
494 case TPACKET_V2:
495 h.h2->tp_sec = ts.tv_sec;
496 h.h2->tp_nsec = ts.tv_nsec;
497 break;
498 case TPACKET_V3:
499 h.h3->tp_sec = ts.tv_sec;
500 h.h3->tp_nsec = ts.tv_nsec;
501 break;
502 default:
503 WARN(1, "TPACKET version not supported.\n");
504 BUG();
505 }
506
507 /* one flush is safe, as both fields always lie on the same cacheline */
508 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
509 smp_wmb();
510
511 return ts_status;
512}
513
514static void *packet_lookup_frame(const struct packet_sock *po,
515 const struct packet_ring_buffer *rb,
516 unsigned int position,
517 int status)
518{
519 unsigned int pg_vec_pos, frame_offset;
520 union tpacket_uhdr h;
521
522 pg_vec_pos = position / rb->frames_per_block;
523 frame_offset = position % rb->frames_per_block;
524
525 h.raw = rb->pg_vec[pg_vec_pos].buffer +
526 (frame_offset * rb->frame_size);
527
528 if (status != __packet_get_status(po, h.raw))
529 return NULL;
530
531 return h.raw;
532}
533
534static void *packet_current_frame(struct packet_sock *po,
535 struct packet_ring_buffer *rb,
536 int status)
537{
538 return packet_lookup_frame(po, rb, rb->head, status);
539}
540
541static u16 vlan_get_tci(const struct sk_buff *skb, struct net_device *dev)
542{
543 struct vlan_hdr vhdr, *vh;
544 unsigned int header_len;
545
546 if (!dev)
547 return 0;
548
549 /* In the SOCK_DGRAM scenario, skb data starts at the network
550 * protocol, which is after the VLAN headers. The outer VLAN
551 * header is at the hard_header_len offset in non-variable
552 * length link layer headers. If it's a VLAN device, the
553 * min_header_len should be used to exclude the VLAN header
554 * size.
555 */
556 if (dev->min_header_len == dev->hard_header_len)
557 header_len = dev->hard_header_len;
558 else if (is_vlan_dev(dev))
559 header_len = dev->min_header_len;
560 else
561 return 0;
562
563 vh = skb_header_pointer(skb, skb_mac_offset(skb) + header_len,
564 sizeof(vhdr), &vhdr);
565 if (unlikely(!vh))
566 return 0;
567
568 return ntohs(vh->h_vlan_TCI);
569}
570
571static __be16 vlan_get_protocol_dgram(const struct sk_buff *skb)
572{
573 __be16 proto = skb->protocol;
574
575 if (unlikely(eth_type_vlan(proto)))
576 proto = __vlan_get_protocol_offset(skb, proto,
577 skb_mac_offset(skb), NULL);
578
579 return proto;
580}
581
582static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
583{
584 del_timer_sync(&pkc->retire_blk_timer);
585}
586
587static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
588 struct sk_buff_head *rb_queue)
589{
590 struct tpacket_kbdq_core *pkc;
591
592 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
593
594 spin_lock_bh(&rb_queue->lock);
595 pkc->delete_blk_timer = 1;
596 spin_unlock_bh(&rb_queue->lock);
597
598 prb_del_retire_blk_timer(pkc);
599}
600
601static void prb_setup_retire_blk_timer(struct packet_sock *po)
602{
603 struct tpacket_kbdq_core *pkc;
604
605 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
606 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
607 0);
608 pkc->retire_blk_timer.expires = jiffies;
609}
610
611static int prb_calc_retire_blk_tmo(struct packet_sock *po,
612 int blk_size_in_bytes)
613{
614 struct net_device *dev;
615 unsigned int mbits, div;
616 struct ethtool_link_ksettings ecmd;
617 int err;
618
619 rtnl_lock();
620 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
621 if (unlikely(!dev)) {
622 rtnl_unlock();
623 return DEFAULT_PRB_RETIRE_TOV;
624 }
625 err = __ethtool_get_link_ksettings(dev, &ecmd);
626 rtnl_unlock();
627 if (err)
628 return DEFAULT_PRB_RETIRE_TOV;
629
630 /* If the link speed is so slow you don't really
631 * need to worry about perf anyways
632 */
633 if (ecmd.base.speed < SPEED_1000 ||
634 ecmd.base.speed == SPEED_UNKNOWN)
635 return DEFAULT_PRB_RETIRE_TOV;
636
637 div = ecmd.base.speed / 1000;
638 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
639
640 if (div)
641 mbits /= div;
642
643 if (div)
644 return mbits + 1;
645 return mbits;
646}
647
648static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
649 union tpacket_req_u *req_u)
650{
651 p1->feature_req_word = req_u->req3.tp_feature_req_word;
652}
653
654static void init_prb_bdqc(struct packet_sock *po,
655 struct packet_ring_buffer *rb,
656 struct pgv *pg_vec,
657 union tpacket_req_u *req_u)
658{
659 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
660 struct tpacket_block_desc *pbd;
661
662 memset(p1, 0x0, sizeof(*p1));
663
664 p1->knxt_seq_num = 1;
665 p1->pkbdq = pg_vec;
666 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
667 p1->pkblk_start = pg_vec[0].buffer;
668 p1->kblk_size = req_u->req3.tp_block_size;
669 p1->knum_blocks = req_u->req3.tp_block_nr;
670 p1->hdrlen = po->tp_hdrlen;
671 p1->version = po->tp_version;
672 p1->last_kactive_blk_num = 0;
673 po->stats.stats3.tp_freeze_q_cnt = 0;
674 if (req_u->req3.tp_retire_blk_tov)
675 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
676 else
677 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
678 req_u->req3.tp_block_size);
679 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
680 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
681 rwlock_init(&p1->blk_fill_in_prog_lock);
682
683 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
684 prb_init_ft_ops(p1, req_u);
685 prb_setup_retire_blk_timer(po);
686 prb_open_block(p1, pbd);
687}
688
689/* Do NOT update the last_blk_num first.
690 * Assumes sk_buff_head lock is held.
691 */
692static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
693{
694 mod_timer(&pkc->retire_blk_timer,
695 jiffies + pkc->tov_in_jiffies);
696 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
697}
698
699/*
700 * Timer logic:
701 * 1) We refresh the timer only when we open a block.
702 * By doing this we don't waste cycles refreshing the timer
703 * on packet-by-packet basis.
704 *
705 * With a 1MB block-size, on a 1Gbps line, it will take
706 * i) ~8 ms to fill a block + ii) memcpy etc.
707 * In this cut we are not accounting for the memcpy time.
708 *
709 * So, if the user sets the 'tmo' to 10ms then the timer
710 * will never fire while the block is still getting filled
711 * (which is what we want). However, the user could choose
712 * to close a block early and that's fine.
713 *
714 * But when the timer does fire, we check whether or not to refresh it.
715 * Since the tmo granularity is in msecs, it is not too expensive
716 * to refresh the timer, lets say every '8' msecs.
717 * Either the user can set the 'tmo' or we can derive it based on
718 * a) line-speed and b) block-size.
719 * prb_calc_retire_blk_tmo() calculates the tmo.
720 *
721 */
722static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
723{
724 struct packet_sock *po =
725 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
726 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
727 unsigned int frozen;
728 struct tpacket_block_desc *pbd;
729
730 spin_lock(&po->sk.sk_receive_queue.lock);
731
732 frozen = prb_queue_frozen(pkc);
733 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
734
735 if (unlikely(pkc->delete_blk_timer))
736 goto out;
737
738 /* We only need to plug the race when the block is partially filled.
739 * tpacket_rcv:
740 * lock(); increment BLOCK_NUM_PKTS; unlock()
741 * copy_bits() is in progress ...
742 * timer fires on other cpu:
743 * we can't retire the current block because copy_bits
744 * is in progress.
745 *
746 */
747 if (BLOCK_NUM_PKTS(pbd)) {
748 /* Waiting for skb_copy_bits to finish... */
749 write_lock(&pkc->blk_fill_in_prog_lock);
750 write_unlock(&pkc->blk_fill_in_prog_lock);
751 }
752
753 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
754 if (!frozen) {
755 if (!BLOCK_NUM_PKTS(pbd)) {
756 /* An empty block. Just refresh the timer. */
757 goto refresh_timer;
758 }
759 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
760 if (!prb_dispatch_next_block(pkc, po))
761 goto refresh_timer;
762 else
763 goto out;
764 } else {
765 /* Case 1. Queue was frozen because user-space was
766 * lagging behind.
767 */
768 if (prb_curr_blk_in_use(pbd)) {
769 /*
770 * Ok, user-space is still behind.
771 * So just refresh the timer.
772 */
773 goto refresh_timer;
774 } else {
775 /* Case 2. queue was frozen,user-space caught up,
776 * now the link went idle && the timer fired.
777 * We don't have a block to close.So we open this
778 * block and restart the timer.
779 * opening a block thaws the queue,restarts timer
780 * Thawing/timer-refresh is a side effect.
781 */
782 prb_open_block(pkc, pbd);
783 goto out;
784 }
785 }
786 }
787
788refresh_timer:
789 _prb_refresh_rx_retire_blk_timer(pkc);
790
791out:
792 spin_unlock(&po->sk.sk_receive_queue.lock);
793}
794
795static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
796 struct tpacket_block_desc *pbd1, __u32 status)
797{
798 /* Flush everything minus the block header */
799
800#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
801 u8 *start, *end;
802
803 start = (u8 *)pbd1;
804
805 /* Skip the block header(we know header WILL fit in 4K) */
806 start += PAGE_SIZE;
807
808 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
809 for (; start < end; start += PAGE_SIZE)
810 flush_dcache_page(pgv_to_page(start));
811
812 smp_wmb();
813#endif
814
815 /* Now update the block status. */
816
817 BLOCK_STATUS(pbd1) = status;
818
819 /* Flush the block header */
820
821#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
822 start = (u8 *)pbd1;
823 flush_dcache_page(pgv_to_page(start));
824
825 smp_wmb();
826#endif
827}
828
829/*
830 * Side effect:
831 *
832 * 1) flush the block
833 * 2) Increment active_blk_num
834 *
835 * Note:We DONT refresh the timer on purpose.
836 * Because almost always the next block will be opened.
837 */
838static void prb_close_block(struct tpacket_kbdq_core *pkc1,
839 struct tpacket_block_desc *pbd1,
840 struct packet_sock *po, unsigned int stat)
841{
842 __u32 status = TP_STATUS_USER | stat;
843
844 struct tpacket3_hdr *last_pkt;
845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
846 struct sock *sk = &po->sk;
847
848 if (atomic_read(&po->tp_drops))
849 status |= TP_STATUS_LOSING;
850
851 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
852 last_pkt->tp_next_offset = 0;
853
854 /* Get the ts of the last pkt */
855 if (BLOCK_NUM_PKTS(pbd1)) {
856 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
857 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
858 } else {
859 /* Ok, we tmo'd - so get the current time.
860 *
861 * It shouldn't really happen as we don't close empty
862 * blocks. See prb_retire_rx_blk_timer_expired().
863 */
864 struct timespec64 ts;
865 ktime_get_real_ts64(&ts);
866 h1->ts_last_pkt.ts_sec = ts.tv_sec;
867 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
868 }
869
870 smp_wmb();
871
872 /* Flush the block */
873 prb_flush_block(pkc1, pbd1, status);
874
875 sk->sk_data_ready(sk);
876
877 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
878}
879
880static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
881{
882 pkc->reset_pending_on_curr_blk = 0;
883}
884
885/*
886 * Side effect of opening a block:
887 *
888 * 1) prb_queue is thawed.
889 * 2) retire_blk_timer is refreshed.
890 *
891 */
892static void prb_open_block(struct tpacket_kbdq_core *pkc1,
893 struct tpacket_block_desc *pbd1)
894{
895 struct timespec64 ts;
896 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
897
898 smp_rmb();
899
900 /* We could have just memset this but we will lose the
901 * flexibility of making the priv area sticky
902 */
903
904 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
905 BLOCK_NUM_PKTS(pbd1) = 0;
906 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
907
908 ktime_get_real_ts64(&ts);
909
910 h1->ts_first_pkt.ts_sec = ts.tv_sec;
911 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
912
913 pkc1->pkblk_start = (char *)pbd1;
914 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
915
916 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
917 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
918
919 pbd1->version = pkc1->version;
920 pkc1->prev = pkc1->nxt_offset;
921 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
922
923 prb_thaw_queue(pkc1);
924 _prb_refresh_rx_retire_blk_timer(pkc1);
925
926 smp_wmb();
927}
928
929/*
930 * Queue freeze logic:
931 * 1) Assume tp_block_nr = 8 blocks.
932 * 2) At time 't0', user opens Rx ring.
933 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
934 * 4) user-space is either sleeping or processing block '0'.
935 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
936 * it will close block-7,loop around and try to fill block '0'.
937 * call-flow:
938 * __packet_lookup_frame_in_block
939 * prb_retire_current_block()
940 * prb_dispatch_next_block()
941 * |->(BLOCK_STATUS == USER) evaluates to true
942 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
943 * 6) Now there are two cases:
944 * 6.1) Link goes idle right after the queue is frozen.
945 * But remember, the last open_block() refreshed the timer.
946 * When this timer expires,it will refresh itself so that we can
947 * re-open block-0 in near future.
948 * 6.2) Link is busy and keeps on receiving packets. This is a simple
949 * case and __packet_lookup_frame_in_block will check if block-0
950 * is free and can now be re-used.
951 */
952static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
953 struct packet_sock *po)
954{
955 pkc->reset_pending_on_curr_blk = 1;
956 po->stats.stats3.tp_freeze_q_cnt++;
957}
958
959#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
960
961/*
962 * If the next block is free then we will dispatch it
963 * and return a good offset.
964 * Else, we will freeze the queue.
965 * So, caller must check the return value.
966 */
967static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
968 struct packet_sock *po)
969{
970 struct tpacket_block_desc *pbd;
971
972 smp_rmb();
973
974 /* 1. Get current block num */
975 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
976
977 /* 2. If this block is currently in_use then freeze the queue */
978 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
979 prb_freeze_queue(pkc, po);
980 return NULL;
981 }
982
983 /*
984 * 3.
985 * open this block and return the offset where the first packet
986 * needs to get stored.
987 */
988 prb_open_block(pkc, pbd);
989 return (void *)pkc->nxt_offset;
990}
991
992static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
993 struct packet_sock *po, unsigned int status)
994{
995 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
996
997 /* retire/close the current block */
998 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
999 /*
1000 * Plug the case where copy_bits() is in progress on
1001 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
1002 * have space to copy the pkt in the current block and
1003 * called prb_retire_current_block()
1004 *
1005 * We don't need to worry about the TMO case because
1006 * the timer-handler already handled this case.
1007 */
1008 if (!(status & TP_STATUS_BLK_TMO)) {
1009 /* Waiting for skb_copy_bits to finish... */
1010 write_lock(&pkc->blk_fill_in_prog_lock);
1011 write_unlock(&pkc->blk_fill_in_prog_lock);
1012 }
1013 prb_close_block(pkc, pbd, po, status);
1014 return;
1015 }
1016}
1017
1018static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
1019{
1020 return TP_STATUS_USER & BLOCK_STATUS(pbd);
1021}
1022
1023static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
1024{
1025 return pkc->reset_pending_on_curr_blk;
1026}
1027
1028static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
1029 __releases(&pkc->blk_fill_in_prog_lock)
1030{
1031 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1032
1033 read_unlock(&pkc->blk_fill_in_prog_lock);
1034}
1035
1036static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
1037 struct tpacket3_hdr *ppd)
1038{
1039 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
1040}
1041
1042static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
1043 struct tpacket3_hdr *ppd)
1044{
1045 ppd->hv1.tp_rxhash = 0;
1046}
1047
1048static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1049 struct tpacket3_hdr *ppd)
1050{
1051 struct packet_sock *po = container_of(pkc, struct packet_sock, rx_ring.prb_bdqc);
1052
1053 if (skb_vlan_tag_present(pkc->skb)) {
1054 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1055 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1056 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1057 } else if (unlikely(po->sk.sk_type == SOCK_DGRAM && eth_type_vlan(pkc->skb->protocol))) {
1058 ppd->hv1.tp_vlan_tci = vlan_get_tci(pkc->skb, pkc->skb->dev);
1059 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->protocol);
1060 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1061 } else {
1062 ppd->hv1.tp_vlan_tci = 0;
1063 ppd->hv1.tp_vlan_tpid = 0;
1064 ppd->tp_status = TP_STATUS_AVAILABLE;
1065 }
1066}
1067
1068static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1069 struct tpacket3_hdr *ppd)
1070{
1071 ppd->hv1.tp_padding = 0;
1072 prb_fill_vlan_info(pkc, ppd);
1073
1074 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1075 prb_fill_rxhash(pkc, ppd);
1076 else
1077 prb_clear_rxhash(pkc, ppd);
1078}
1079
1080static void prb_fill_curr_block(char *curr,
1081 struct tpacket_kbdq_core *pkc,
1082 struct tpacket_block_desc *pbd,
1083 unsigned int len)
1084 __acquires(&pkc->blk_fill_in_prog_lock)
1085{
1086 struct tpacket3_hdr *ppd;
1087
1088 ppd = (struct tpacket3_hdr *)curr;
1089 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1090 pkc->prev = curr;
1091 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1092 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1093 BLOCK_NUM_PKTS(pbd) += 1;
1094 read_lock(&pkc->blk_fill_in_prog_lock);
1095 prb_run_all_ft_ops(pkc, ppd);
1096}
1097
1098/* Assumes caller has the sk->rx_queue.lock */
1099static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1100 struct sk_buff *skb,
1101 unsigned int len
1102 )
1103{
1104 struct tpacket_kbdq_core *pkc;
1105 struct tpacket_block_desc *pbd;
1106 char *curr, *end;
1107
1108 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1109 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1110
1111 /* Queue is frozen when user space is lagging behind */
1112 if (prb_queue_frozen(pkc)) {
1113 /*
1114 * Check if that last block which caused the queue to freeze,
1115 * is still in_use by user-space.
1116 */
1117 if (prb_curr_blk_in_use(pbd)) {
1118 /* Can't record this packet */
1119 return NULL;
1120 } else {
1121 /*
1122 * Ok, the block was released by user-space.
1123 * Now let's open that block.
1124 * opening a block also thaws the queue.
1125 * Thawing is a side effect.
1126 */
1127 prb_open_block(pkc, pbd);
1128 }
1129 }
1130
1131 smp_mb();
1132 curr = pkc->nxt_offset;
1133 pkc->skb = skb;
1134 end = (char *)pbd + pkc->kblk_size;
1135
1136 /* first try the current block */
1137 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1138 prb_fill_curr_block(curr, pkc, pbd, len);
1139 return (void *)curr;
1140 }
1141
1142 /* Ok, close the current block */
1143 prb_retire_current_block(pkc, po, 0);
1144
1145 /* Now, try to dispatch the next block */
1146 curr = (char *)prb_dispatch_next_block(pkc, po);
1147 if (curr) {
1148 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1149 prb_fill_curr_block(curr, pkc, pbd, len);
1150 return (void *)curr;
1151 }
1152
1153 /*
1154 * No free blocks are available.user_space hasn't caught up yet.
1155 * Queue was just frozen and now this packet will get dropped.
1156 */
1157 return NULL;
1158}
1159
1160static void *packet_current_rx_frame(struct packet_sock *po,
1161 struct sk_buff *skb,
1162 int status, unsigned int len)
1163{
1164 char *curr = NULL;
1165 switch (po->tp_version) {
1166 case TPACKET_V1:
1167 case TPACKET_V2:
1168 curr = packet_lookup_frame(po, &po->rx_ring,
1169 po->rx_ring.head, status);
1170 return curr;
1171 case TPACKET_V3:
1172 return __packet_lookup_frame_in_block(po, skb, len);
1173 default:
1174 WARN(1, "TPACKET version not supported\n");
1175 BUG();
1176 return NULL;
1177 }
1178}
1179
1180static void *prb_lookup_block(const struct packet_sock *po,
1181 const struct packet_ring_buffer *rb,
1182 unsigned int idx,
1183 int status)
1184{
1185 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1186 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1187
1188 if (status != BLOCK_STATUS(pbd))
1189 return NULL;
1190 return pbd;
1191}
1192
1193static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1194{
1195 unsigned int prev;
1196 if (rb->prb_bdqc.kactive_blk_num)
1197 prev = rb->prb_bdqc.kactive_blk_num-1;
1198 else
1199 prev = rb->prb_bdqc.knum_blocks-1;
1200 return prev;
1201}
1202
1203/* Assumes caller has held the rx_queue.lock */
1204static void *__prb_previous_block(struct packet_sock *po,
1205 struct packet_ring_buffer *rb,
1206 int status)
1207{
1208 unsigned int previous = prb_previous_blk_num(rb);
1209 return prb_lookup_block(po, rb, previous, status);
1210}
1211
1212static void *packet_previous_rx_frame(struct packet_sock *po,
1213 struct packet_ring_buffer *rb,
1214 int status)
1215{
1216 if (po->tp_version <= TPACKET_V2)
1217 return packet_previous_frame(po, rb, status);
1218
1219 return __prb_previous_block(po, rb, status);
1220}
1221
1222static void packet_increment_rx_head(struct packet_sock *po,
1223 struct packet_ring_buffer *rb)
1224{
1225 switch (po->tp_version) {
1226 case TPACKET_V1:
1227 case TPACKET_V2:
1228 return packet_increment_head(rb);
1229 case TPACKET_V3:
1230 default:
1231 WARN(1, "TPACKET version not supported.\n");
1232 BUG();
1233 return;
1234 }
1235}
1236
1237static void *packet_previous_frame(struct packet_sock *po,
1238 struct packet_ring_buffer *rb,
1239 int status)
1240{
1241 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1242 return packet_lookup_frame(po, rb, previous, status);
1243}
1244
1245static void packet_increment_head(struct packet_ring_buffer *buff)
1246{
1247 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1248}
1249
1250static void packet_inc_pending(struct packet_ring_buffer *rb)
1251{
1252 this_cpu_inc(*rb->pending_refcnt);
1253}
1254
1255static void packet_dec_pending(struct packet_ring_buffer *rb)
1256{
1257 this_cpu_dec(*rb->pending_refcnt);
1258}
1259
1260static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1261{
1262 unsigned int refcnt = 0;
1263 int cpu;
1264
1265 /* We don't use pending refcount in rx_ring. */
1266 if (rb->pending_refcnt == NULL)
1267 return 0;
1268
1269 for_each_possible_cpu(cpu)
1270 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1271
1272 return refcnt;
1273}
1274
1275static int packet_alloc_pending(struct packet_sock *po)
1276{
1277 po->rx_ring.pending_refcnt = NULL;
1278
1279 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1280 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1281 return -ENOBUFS;
1282
1283 return 0;
1284}
1285
1286static void packet_free_pending(struct packet_sock *po)
1287{
1288 free_percpu(po->tx_ring.pending_refcnt);
1289}
1290
1291#define ROOM_POW_OFF 2
1292#define ROOM_NONE 0x0
1293#define ROOM_LOW 0x1
1294#define ROOM_NORMAL 0x2
1295
1296static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1297{
1298 int idx, len;
1299
1300 len = READ_ONCE(po->rx_ring.frame_max) + 1;
1301 idx = READ_ONCE(po->rx_ring.head);
1302 if (pow_off)
1303 idx += len >> pow_off;
1304 if (idx >= len)
1305 idx -= len;
1306 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1307}
1308
1309static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1310{
1311 int idx, len;
1312
1313 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1314 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1315 if (pow_off)
1316 idx += len >> pow_off;
1317 if (idx >= len)
1318 idx -= len;
1319 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1320}
1321
1322static int __packet_rcv_has_room(const struct packet_sock *po,
1323 const struct sk_buff *skb)
1324{
1325 const struct sock *sk = &po->sk;
1326 int ret = ROOM_NONE;
1327
1328 if (po->prot_hook.func != tpacket_rcv) {
1329 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1330 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1331 - (skb ? skb->truesize : 0);
1332
1333 if (avail > (rcvbuf >> ROOM_POW_OFF))
1334 return ROOM_NORMAL;
1335 else if (avail > 0)
1336 return ROOM_LOW;
1337 else
1338 return ROOM_NONE;
1339 }
1340
1341 if (po->tp_version == TPACKET_V3) {
1342 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1343 ret = ROOM_NORMAL;
1344 else if (__tpacket_v3_has_room(po, 0))
1345 ret = ROOM_LOW;
1346 } else {
1347 if (__tpacket_has_room(po, ROOM_POW_OFF))
1348 ret = ROOM_NORMAL;
1349 else if (__tpacket_has_room(po, 0))
1350 ret = ROOM_LOW;
1351 }
1352
1353 return ret;
1354}
1355
1356static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1357{
1358 bool pressure;
1359 int ret;
1360
1361 ret = __packet_rcv_has_room(po, skb);
1362 pressure = ret != ROOM_NORMAL;
1363
1364 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure)
1365 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure);
1366
1367 return ret;
1368}
1369
1370static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1371{
1372 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) &&
1373 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1374 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false);
1375}
1376
1377static void packet_sock_destruct(struct sock *sk)
1378{
1379 skb_queue_purge(&sk->sk_error_queue);
1380
1381 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1382 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1383
1384 if (!sock_flag(sk, SOCK_DEAD)) {
1385 pr_err("Attempt to release alive packet socket: %p\n", sk);
1386 return;
1387 }
1388}
1389
1390static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1391{
1392 u32 *history = po->rollover->history;
1393 u32 victim, rxhash;
1394 int i, count = 0;
1395
1396 rxhash = skb_get_hash(skb);
1397 for (i = 0; i < ROLLOVER_HLEN; i++)
1398 if (READ_ONCE(history[i]) == rxhash)
1399 count++;
1400
1401 victim = get_random_u32_below(ROLLOVER_HLEN);
1402
1403 /* Avoid dirtying the cache line if possible */
1404 if (READ_ONCE(history[victim]) != rxhash)
1405 WRITE_ONCE(history[victim], rxhash);
1406
1407 return count > (ROLLOVER_HLEN >> 1);
1408}
1409
1410static unsigned int fanout_demux_hash(struct packet_fanout *f,
1411 struct sk_buff *skb,
1412 unsigned int num)
1413{
1414 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1415}
1416
1417static unsigned int fanout_demux_lb(struct packet_fanout *f,
1418 struct sk_buff *skb,
1419 unsigned int num)
1420{
1421 unsigned int val = atomic_inc_return(&f->rr_cur);
1422
1423 return val % num;
1424}
1425
1426static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1427 struct sk_buff *skb,
1428 unsigned int num)
1429{
1430 return smp_processor_id() % num;
1431}
1432
1433static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1434 struct sk_buff *skb,
1435 unsigned int num)
1436{
1437 return get_random_u32_below(num);
1438}
1439
1440static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1441 struct sk_buff *skb,
1442 unsigned int idx, bool try_self,
1443 unsigned int num)
1444{
1445 struct packet_sock *po, *po_next, *po_skip = NULL;
1446 unsigned int i, j, room = ROOM_NONE;
1447
1448 po = pkt_sk(rcu_dereference(f->arr[idx]));
1449
1450 if (try_self) {
1451 room = packet_rcv_has_room(po, skb);
1452 if (room == ROOM_NORMAL ||
1453 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1454 return idx;
1455 po_skip = po;
1456 }
1457
1458 i = j = min_t(int, po->rollover->sock, num - 1);
1459 do {
1460 po_next = pkt_sk(rcu_dereference(f->arr[i]));
1461 if (po_next != po_skip &&
1462 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) &&
1463 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1464 if (i != j)
1465 po->rollover->sock = i;
1466 atomic_long_inc(&po->rollover->num);
1467 if (room == ROOM_LOW)
1468 atomic_long_inc(&po->rollover->num_huge);
1469 return i;
1470 }
1471
1472 if (++i == num)
1473 i = 0;
1474 } while (i != j);
1475
1476 atomic_long_inc(&po->rollover->num_failed);
1477 return idx;
1478}
1479
1480static unsigned int fanout_demux_qm(struct packet_fanout *f,
1481 struct sk_buff *skb,
1482 unsigned int num)
1483{
1484 return skb_get_queue_mapping(skb) % num;
1485}
1486
1487static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1488 struct sk_buff *skb,
1489 unsigned int num)
1490{
1491 struct bpf_prog *prog;
1492 unsigned int ret = 0;
1493
1494 rcu_read_lock();
1495 prog = rcu_dereference(f->bpf_prog);
1496 if (prog)
1497 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1498 rcu_read_unlock();
1499
1500 return ret;
1501}
1502
1503static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1504{
1505 return f->flags & (flag >> 8);
1506}
1507
1508static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1509 struct packet_type *pt, struct net_device *orig_dev)
1510{
1511 struct packet_fanout *f = pt->af_packet_priv;
1512 unsigned int num = READ_ONCE(f->num_members);
1513 struct net *net = read_pnet(&f->net);
1514 struct packet_sock *po;
1515 unsigned int idx;
1516
1517 if (!net_eq(dev_net(dev), net) || !num) {
1518 kfree_skb(skb);
1519 return 0;
1520 }
1521
1522 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1523 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1524 if (!skb)
1525 return 0;
1526 }
1527 switch (f->type) {
1528 case PACKET_FANOUT_HASH:
1529 default:
1530 idx = fanout_demux_hash(f, skb, num);
1531 break;
1532 case PACKET_FANOUT_LB:
1533 idx = fanout_demux_lb(f, skb, num);
1534 break;
1535 case PACKET_FANOUT_CPU:
1536 idx = fanout_demux_cpu(f, skb, num);
1537 break;
1538 case PACKET_FANOUT_RND:
1539 idx = fanout_demux_rnd(f, skb, num);
1540 break;
1541 case PACKET_FANOUT_QM:
1542 idx = fanout_demux_qm(f, skb, num);
1543 break;
1544 case PACKET_FANOUT_ROLLOVER:
1545 idx = fanout_demux_rollover(f, skb, 0, false, num);
1546 break;
1547 case PACKET_FANOUT_CBPF:
1548 case PACKET_FANOUT_EBPF:
1549 idx = fanout_demux_bpf(f, skb, num);
1550 break;
1551 }
1552
1553 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1554 idx = fanout_demux_rollover(f, skb, idx, true, num);
1555
1556 po = pkt_sk(rcu_dereference(f->arr[idx]));
1557 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1558}
1559
1560DEFINE_MUTEX(fanout_mutex);
1561EXPORT_SYMBOL_GPL(fanout_mutex);
1562static LIST_HEAD(fanout_list);
1563static u16 fanout_next_id;
1564
1565static void __fanout_link(struct sock *sk, struct packet_sock *po)
1566{
1567 struct packet_fanout *f = po->fanout;
1568
1569 spin_lock(&f->lock);
1570 rcu_assign_pointer(f->arr[f->num_members], sk);
1571 smp_wmb();
1572 f->num_members++;
1573 if (f->num_members == 1)
1574 dev_add_pack(&f->prot_hook);
1575 spin_unlock(&f->lock);
1576}
1577
1578static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1579{
1580 struct packet_fanout *f = po->fanout;
1581 int i;
1582
1583 spin_lock(&f->lock);
1584 for (i = 0; i < f->num_members; i++) {
1585 if (rcu_dereference_protected(f->arr[i],
1586 lockdep_is_held(&f->lock)) == sk)
1587 break;
1588 }
1589 BUG_ON(i >= f->num_members);
1590 rcu_assign_pointer(f->arr[i],
1591 rcu_dereference_protected(f->arr[f->num_members - 1],
1592 lockdep_is_held(&f->lock)));
1593 f->num_members--;
1594 if (f->num_members == 0)
1595 __dev_remove_pack(&f->prot_hook);
1596 spin_unlock(&f->lock);
1597}
1598
1599static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1600{
1601 if (sk->sk_family != PF_PACKET)
1602 return false;
1603
1604 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1605}
1606
1607static void fanout_init_data(struct packet_fanout *f)
1608{
1609 switch (f->type) {
1610 case PACKET_FANOUT_LB:
1611 atomic_set(&f->rr_cur, 0);
1612 break;
1613 case PACKET_FANOUT_CBPF:
1614 case PACKET_FANOUT_EBPF:
1615 RCU_INIT_POINTER(f->bpf_prog, NULL);
1616 break;
1617 }
1618}
1619
1620static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1621{
1622 struct bpf_prog *old;
1623
1624 spin_lock(&f->lock);
1625 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1626 rcu_assign_pointer(f->bpf_prog, new);
1627 spin_unlock(&f->lock);
1628
1629 if (old) {
1630 synchronize_net();
1631 bpf_prog_destroy(old);
1632 }
1633}
1634
1635static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1636 unsigned int len)
1637{
1638 struct bpf_prog *new;
1639 struct sock_fprog fprog;
1640 int ret;
1641
1642 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1643 return -EPERM;
1644
1645 ret = copy_bpf_fprog_from_user(&fprog, data, len);
1646 if (ret)
1647 return ret;
1648
1649 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1650 if (ret)
1651 return ret;
1652
1653 __fanout_set_data_bpf(po->fanout, new);
1654 return 0;
1655}
1656
1657static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1658 unsigned int len)
1659{
1660 struct bpf_prog *new;
1661 u32 fd;
1662
1663 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1664 return -EPERM;
1665 if (len != sizeof(fd))
1666 return -EINVAL;
1667 if (copy_from_sockptr(&fd, data, len))
1668 return -EFAULT;
1669
1670 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1671 if (IS_ERR(new))
1672 return PTR_ERR(new);
1673
1674 __fanout_set_data_bpf(po->fanout, new);
1675 return 0;
1676}
1677
1678static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1679 unsigned int len)
1680{
1681 switch (po->fanout->type) {
1682 case PACKET_FANOUT_CBPF:
1683 return fanout_set_data_cbpf(po, data, len);
1684 case PACKET_FANOUT_EBPF:
1685 return fanout_set_data_ebpf(po, data, len);
1686 default:
1687 return -EINVAL;
1688 }
1689}
1690
1691static void fanout_release_data(struct packet_fanout *f)
1692{
1693 switch (f->type) {
1694 case PACKET_FANOUT_CBPF:
1695 case PACKET_FANOUT_EBPF:
1696 __fanout_set_data_bpf(f, NULL);
1697 }
1698}
1699
1700static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1701{
1702 struct packet_fanout *f;
1703
1704 list_for_each_entry(f, &fanout_list, list) {
1705 if (f->id == candidate_id &&
1706 read_pnet(&f->net) == sock_net(sk)) {
1707 return false;
1708 }
1709 }
1710 return true;
1711}
1712
1713static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1714{
1715 u16 id = fanout_next_id;
1716
1717 do {
1718 if (__fanout_id_is_free(sk, id)) {
1719 *new_id = id;
1720 fanout_next_id = id + 1;
1721 return true;
1722 }
1723
1724 id++;
1725 } while (id != fanout_next_id);
1726
1727 return false;
1728}
1729
1730static int fanout_add(struct sock *sk, struct fanout_args *args)
1731{
1732 struct packet_rollover *rollover = NULL;
1733 struct packet_sock *po = pkt_sk(sk);
1734 u16 type_flags = args->type_flags;
1735 struct packet_fanout *f, *match;
1736 u8 type = type_flags & 0xff;
1737 u8 flags = type_flags >> 8;
1738 u16 id = args->id;
1739 int err;
1740
1741 switch (type) {
1742 case PACKET_FANOUT_ROLLOVER:
1743 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1744 return -EINVAL;
1745 break;
1746 case PACKET_FANOUT_HASH:
1747 case PACKET_FANOUT_LB:
1748 case PACKET_FANOUT_CPU:
1749 case PACKET_FANOUT_RND:
1750 case PACKET_FANOUT_QM:
1751 case PACKET_FANOUT_CBPF:
1752 case PACKET_FANOUT_EBPF:
1753 break;
1754 default:
1755 return -EINVAL;
1756 }
1757
1758 mutex_lock(&fanout_mutex);
1759
1760 err = -EALREADY;
1761 if (po->fanout)
1762 goto out;
1763
1764 if (type == PACKET_FANOUT_ROLLOVER ||
1765 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1766 err = -ENOMEM;
1767 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1768 if (!rollover)
1769 goto out;
1770 atomic_long_set(&rollover->num, 0);
1771 atomic_long_set(&rollover->num_huge, 0);
1772 atomic_long_set(&rollover->num_failed, 0);
1773 }
1774
1775 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1776 if (id != 0) {
1777 err = -EINVAL;
1778 goto out;
1779 }
1780 if (!fanout_find_new_id(sk, &id)) {
1781 err = -ENOMEM;
1782 goto out;
1783 }
1784 /* ephemeral flag for the first socket in the group: drop it */
1785 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1786 }
1787
1788 match = NULL;
1789 list_for_each_entry(f, &fanout_list, list) {
1790 if (f->id == id &&
1791 read_pnet(&f->net) == sock_net(sk)) {
1792 match = f;
1793 break;
1794 }
1795 }
1796 err = -EINVAL;
1797 if (match) {
1798 if (match->flags != flags)
1799 goto out;
1800 if (args->max_num_members &&
1801 args->max_num_members != match->max_num_members)
1802 goto out;
1803 } else {
1804 if (args->max_num_members > PACKET_FANOUT_MAX)
1805 goto out;
1806 if (!args->max_num_members)
1807 /* legacy PACKET_FANOUT_MAX */
1808 args->max_num_members = 256;
1809 err = -ENOMEM;
1810 match = kvzalloc(struct_size(match, arr, args->max_num_members),
1811 GFP_KERNEL);
1812 if (!match)
1813 goto out;
1814 write_pnet(&match->net, sock_net(sk));
1815 match->id = id;
1816 match->type = type;
1817 match->flags = flags;
1818 INIT_LIST_HEAD(&match->list);
1819 spin_lock_init(&match->lock);
1820 refcount_set(&match->sk_ref, 0);
1821 fanout_init_data(match);
1822 match->prot_hook.type = po->prot_hook.type;
1823 match->prot_hook.dev = po->prot_hook.dev;
1824 match->prot_hook.func = packet_rcv_fanout;
1825 match->prot_hook.af_packet_priv = match;
1826 match->prot_hook.af_packet_net = read_pnet(&match->net);
1827 match->prot_hook.id_match = match_fanout_group;
1828 match->max_num_members = args->max_num_members;
1829 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING;
1830 list_add(&match->list, &fanout_list);
1831 }
1832 err = -EINVAL;
1833
1834 spin_lock(&po->bind_lock);
1835 if (po->num &&
1836 match->type == type &&
1837 match->prot_hook.type == po->prot_hook.type &&
1838 match->prot_hook.dev == po->prot_hook.dev) {
1839 err = -ENOSPC;
1840 if (refcount_read(&match->sk_ref) < match->max_num_members) {
1841 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
1842 WRITE_ONCE(po->fanout, match);
1843
1844 po->rollover = rollover;
1845 rollover = NULL;
1846 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1847 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
1848 __dev_remove_pack(&po->prot_hook);
1849 __fanout_link(sk, po);
1850 }
1851 err = 0;
1852 }
1853 }
1854 spin_unlock(&po->bind_lock);
1855
1856 if (err && !refcount_read(&match->sk_ref)) {
1857 list_del(&match->list);
1858 kvfree(match);
1859 }
1860
1861out:
1862 kfree(rollover);
1863 mutex_unlock(&fanout_mutex);
1864 return err;
1865}
1866
1867/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1868 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1869 * It is the responsibility of the caller to call fanout_release_data() and
1870 * free the returned packet_fanout (after synchronize_net())
1871 */
1872static struct packet_fanout *fanout_release(struct sock *sk)
1873{
1874 struct packet_sock *po = pkt_sk(sk);
1875 struct packet_fanout *f;
1876
1877 mutex_lock(&fanout_mutex);
1878 f = po->fanout;
1879 if (f) {
1880 po->fanout = NULL;
1881
1882 if (refcount_dec_and_test(&f->sk_ref))
1883 list_del(&f->list);
1884 else
1885 f = NULL;
1886 }
1887 mutex_unlock(&fanout_mutex);
1888
1889 return f;
1890}
1891
1892static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1893 struct sk_buff *skb)
1894{
1895 /* Earlier code assumed this would be a VLAN pkt, double-check
1896 * this now that we have the actual packet in hand. We can only
1897 * do this check on Ethernet devices.
1898 */
1899 if (unlikely(dev->type != ARPHRD_ETHER))
1900 return false;
1901
1902 skb_reset_mac_header(skb);
1903 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1904}
1905
1906static const struct proto_ops packet_ops;
1907
1908static const struct proto_ops packet_ops_spkt;
1909
1910static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1911 struct packet_type *pt, struct net_device *orig_dev)
1912{
1913 struct sock *sk;
1914 struct sockaddr_pkt *spkt;
1915
1916 /*
1917 * When we registered the protocol we saved the socket in the data
1918 * field for just this event.
1919 */
1920
1921 sk = pt->af_packet_priv;
1922
1923 /*
1924 * Yank back the headers [hope the device set this
1925 * right or kerboom...]
1926 *
1927 * Incoming packets have ll header pulled,
1928 * push it back.
1929 *
1930 * For outgoing ones skb->data == skb_mac_header(skb)
1931 * so that this procedure is noop.
1932 */
1933
1934 if (skb->pkt_type == PACKET_LOOPBACK)
1935 goto out;
1936
1937 if (!net_eq(dev_net(dev), sock_net(sk)))
1938 goto out;
1939
1940 skb = skb_share_check(skb, GFP_ATOMIC);
1941 if (skb == NULL)
1942 goto oom;
1943
1944 /* drop any routing info */
1945 skb_dst_drop(skb);
1946
1947 /* drop conntrack reference */
1948 nf_reset_ct(skb);
1949
1950 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1951
1952 skb_push(skb, skb->data - skb_mac_header(skb));
1953
1954 /*
1955 * The SOCK_PACKET socket receives _all_ frames.
1956 */
1957
1958 spkt->spkt_family = dev->type;
1959 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1960 spkt->spkt_protocol = skb->protocol;
1961
1962 /*
1963 * Charge the memory to the socket. This is done specifically
1964 * to prevent sockets using all the memory up.
1965 */
1966
1967 if (sock_queue_rcv_skb(sk, skb) == 0)
1968 return 0;
1969
1970out:
1971 kfree_skb(skb);
1972oom:
1973 return 0;
1974}
1975
1976static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1977{
1978 int depth;
1979
1980 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1981 sock->type == SOCK_RAW) {
1982 skb_reset_mac_header(skb);
1983 skb->protocol = dev_parse_header_protocol(skb);
1984 }
1985
1986 /* Move network header to the right position for VLAN tagged packets */
1987 if (likely(skb->dev->type == ARPHRD_ETHER) &&
1988 eth_type_vlan(skb->protocol) &&
1989 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0)
1990 skb_set_network_header(skb, depth);
1991
1992 skb_probe_transport_header(skb);
1993}
1994
1995/*
1996 * Output a raw packet to a device layer. This bypasses all the other
1997 * protocol layers and you must therefore supply it with a complete frame
1998 */
1999
2000static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
2001 size_t len)
2002{
2003 struct sock *sk = sock->sk;
2004 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
2005 struct sk_buff *skb = NULL;
2006 struct net_device *dev;
2007 struct sockcm_cookie sockc;
2008 __be16 proto = 0;
2009 int err;
2010 int extra_len = 0;
2011
2012 /*
2013 * Get and verify the address.
2014 */
2015
2016 if (saddr) {
2017 if (msg->msg_namelen < sizeof(struct sockaddr))
2018 return -EINVAL;
2019 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
2020 proto = saddr->spkt_protocol;
2021 } else
2022 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
2023
2024 /*
2025 * Find the device first to size check it
2026 */
2027
2028 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
2029retry:
2030 rcu_read_lock();
2031 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
2032 err = -ENODEV;
2033 if (dev == NULL)
2034 goto out_unlock;
2035
2036 err = -ENETDOWN;
2037 if (!(dev->flags & IFF_UP))
2038 goto out_unlock;
2039
2040 /*
2041 * You may not queue a frame bigger than the mtu. This is the lowest level
2042 * raw protocol and you must do your own fragmentation at this level.
2043 */
2044
2045 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2046 if (!netif_supports_nofcs(dev)) {
2047 err = -EPROTONOSUPPORT;
2048 goto out_unlock;
2049 }
2050 extra_len = 4; /* We're doing our own CRC */
2051 }
2052
2053 err = -EMSGSIZE;
2054 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
2055 goto out_unlock;
2056
2057 if (!skb) {
2058 size_t reserved = LL_RESERVED_SPACE(dev);
2059 int tlen = dev->needed_tailroom;
2060 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
2061
2062 rcu_read_unlock();
2063 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
2064 if (skb == NULL)
2065 return -ENOBUFS;
2066 /* FIXME: Save some space for broken drivers that write a hard
2067 * header at transmission time by themselves. PPP is the notable
2068 * one here. This should really be fixed at the driver level.
2069 */
2070 skb_reserve(skb, reserved);
2071 skb_reset_network_header(skb);
2072
2073 /* Try to align data part correctly */
2074 if (hhlen) {
2075 skb->data -= hhlen;
2076 skb->tail -= hhlen;
2077 if (len < hhlen)
2078 skb_reset_network_header(skb);
2079 }
2080 err = memcpy_from_msg(skb_put(skb, len), msg, len);
2081 if (err)
2082 goto out_free;
2083 goto retry;
2084 }
2085
2086 if (!dev_validate_header(dev, skb->data, len) || !skb->len) {
2087 err = -EINVAL;
2088 goto out_unlock;
2089 }
2090 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
2091 !packet_extra_vlan_len_allowed(dev, skb)) {
2092 err = -EMSGSIZE;
2093 goto out_unlock;
2094 }
2095
2096 sockcm_init(&sockc, sk);
2097 if (msg->msg_controllen) {
2098 err = sock_cmsg_send(sk, msg, &sockc);
2099 if (unlikely(err))
2100 goto out_unlock;
2101 }
2102
2103 skb->protocol = proto;
2104 skb->dev = dev;
2105 skb->priority = READ_ONCE(sk->sk_priority);
2106 skb->mark = READ_ONCE(sk->sk_mark);
2107 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid);
2108 skb_setup_tx_timestamp(skb, &sockc);
2109
2110 if (unlikely(extra_len == 4))
2111 skb->no_fcs = 1;
2112
2113 packet_parse_headers(skb, sock);
2114
2115 dev_queue_xmit(skb);
2116 rcu_read_unlock();
2117 return len;
2118
2119out_unlock:
2120 rcu_read_unlock();
2121out_free:
2122 kfree_skb(skb);
2123 return err;
2124}
2125
2126static unsigned int run_filter(struct sk_buff *skb,
2127 const struct sock *sk,
2128 unsigned int res)
2129{
2130 struct sk_filter *filter;
2131
2132 rcu_read_lock();
2133 filter = rcu_dereference(sk->sk_filter);
2134 if (filter != NULL)
2135 res = bpf_prog_run_clear_cb(filter->prog, skb);
2136 rcu_read_unlock();
2137
2138 return res;
2139}
2140
2141static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2142 size_t *len, int vnet_hdr_sz)
2143{
2144 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 };
2145
2146 if (*len < vnet_hdr_sz)
2147 return -EINVAL;
2148 *len -= vnet_hdr_sz;
2149
2150 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0))
2151 return -EINVAL;
2152
2153 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz);
2154}
2155
2156/*
2157 * This function makes lazy skb cloning in hope that most of packets
2158 * are discarded by BPF.
2159 *
2160 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2161 * and skb->cb are mangled. It works because (and until) packets
2162 * falling here are owned by current CPU. Output packets are cloned
2163 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2164 * sequentially, so that if we return skb to original state on exit,
2165 * we will not harm anyone.
2166 */
2167
2168static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2169 struct packet_type *pt, struct net_device *orig_dev)
2170{
2171 enum skb_drop_reason drop_reason = SKB_CONSUMED;
2172 struct sock *sk = NULL;
2173 struct sockaddr_ll *sll;
2174 struct packet_sock *po;
2175 u8 *skb_head = skb->data;
2176 int skb_len = skb->len;
2177 unsigned int snaplen, res;
2178
2179 if (skb->pkt_type == PACKET_LOOPBACK)
2180 goto drop;
2181
2182 sk = pt->af_packet_priv;
2183 po = pkt_sk(sk);
2184
2185 if (!net_eq(dev_net(dev), sock_net(sk)))
2186 goto drop;
2187
2188 skb->dev = dev;
2189
2190 if (dev_has_header(dev)) {
2191 /* The device has an explicit notion of ll header,
2192 * exported to higher levels.
2193 *
2194 * Otherwise, the device hides details of its frame
2195 * structure, so that corresponding packet head is
2196 * never delivered to user.
2197 */
2198 if (sk->sk_type != SOCK_DGRAM)
2199 skb_push(skb, skb->data - skb_mac_header(skb));
2200 else if (skb->pkt_type == PACKET_OUTGOING) {
2201 /* Special case: outgoing packets have ll header at head */
2202 skb_pull(skb, skb_network_offset(skb));
2203 }
2204 }
2205
2206 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb);
2207
2208 res = run_filter(skb, sk, snaplen);
2209 if (!res)
2210 goto drop_n_restore;
2211 if (snaplen > res)
2212 snaplen = res;
2213
2214 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2215 goto drop_n_acct;
2216
2217 if (skb_shared(skb)) {
2218 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2219 if (nskb == NULL)
2220 goto drop_n_acct;
2221
2222 if (skb_head != skb->data) {
2223 skb->data = skb_head;
2224 skb->len = skb_len;
2225 }
2226 consume_skb(skb);
2227 skb = nskb;
2228 }
2229
2230 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2231
2232 sll = &PACKET_SKB_CB(skb)->sa.ll;
2233 sll->sll_hatype = dev->type;
2234 sll->sll_pkttype = skb->pkt_type;
2235 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
2236 sll->sll_ifindex = orig_dev->ifindex;
2237 else
2238 sll->sll_ifindex = dev->ifindex;
2239
2240 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2241
2242 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2243 * Use their space for storing the original skb length.
2244 */
2245 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2246
2247 if (pskb_trim(skb, snaplen))
2248 goto drop_n_acct;
2249
2250 skb_set_owner_r(skb, sk);
2251 skb->dev = NULL;
2252 skb_dst_drop(skb);
2253
2254 /* drop conntrack reference */
2255 nf_reset_ct(skb);
2256
2257 spin_lock(&sk->sk_receive_queue.lock);
2258 po->stats.stats1.tp_packets++;
2259 sock_skb_set_dropcount(sk, skb);
2260 skb_clear_delivery_time(skb);
2261 __skb_queue_tail(&sk->sk_receive_queue, skb);
2262 spin_unlock(&sk->sk_receive_queue.lock);
2263 sk->sk_data_ready(sk);
2264 return 0;
2265
2266drop_n_acct:
2267 atomic_inc(&po->tp_drops);
2268 atomic_inc(&sk->sk_drops);
2269 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR;
2270
2271drop_n_restore:
2272 if (skb_head != skb->data && skb_shared(skb)) {
2273 skb->data = skb_head;
2274 skb->len = skb_len;
2275 }
2276drop:
2277 sk_skb_reason_drop(sk, skb, drop_reason);
2278 return 0;
2279}
2280
2281static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2282 struct packet_type *pt, struct net_device *orig_dev)
2283{
2284 enum skb_drop_reason drop_reason = SKB_CONSUMED;
2285 struct sock *sk = NULL;
2286 struct packet_sock *po;
2287 struct sockaddr_ll *sll;
2288 union tpacket_uhdr h;
2289 u8 *skb_head = skb->data;
2290 int skb_len = skb->len;
2291 unsigned int snaplen, res;
2292 unsigned long status = TP_STATUS_USER;
2293 unsigned short macoff, hdrlen;
2294 unsigned int netoff;
2295 struct sk_buff *copy_skb = NULL;
2296 struct timespec64 ts;
2297 __u32 ts_status;
2298 unsigned int slot_id = 0;
2299 int vnet_hdr_sz = 0;
2300
2301 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2302 * We may add members to them until current aligned size without forcing
2303 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2304 */
2305 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2306 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2307
2308 if (skb->pkt_type == PACKET_LOOPBACK)
2309 goto drop;
2310
2311 sk = pt->af_packet_priv;
2312 po = pkt_sk(sk);
2313
2314 if (!net_eq(dev_net(dev), sock_net(sk)))
2315 goto drop;
2316
2317 if (dev_has_header(dev)) {
2318 if (sk->sk_type != SOCK_DGRAM)
2319 skb_push(skb, skb->data - skb_mac_header(skb));
2320 else if (skb->pkt_type == PACKET_OUTGOING) {
2321 /* Special case: outgoing packets have ll header at head */
2322 skb_pull(skb, skb_network_offset(skb));
2323 }
2324 }
2325
2326 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb);
2327
2328 res = run_filter(skb, sk, snaplen);
2329 if (!res)
2330 goto drop_n_restore;
2331
2332 /* If we are flooded, just give up */
2333 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2334 atomic_inc(&po->tp_drops);
2335 goto drop_n_restore;
2336 }
2337
2338 if (skb->ip_summed == CHECKSUM_PARTIAL)
2339 status |= TP_STATUS_CSUMNOTREADY;
2340 else if (skb->pkt_type != PACKET_OUTGOING &&
2341 skb_csum_unnecessary(skb))
2342 status |= TP_STATUS_CSUM_VALID;
2343 if (skb_is_gso(skb) && skb_is_gso_tcp(skb))
2344 status |= TP_STATUS_GSO_TCP;
2345
2346 if (snaplen > res)
2347 snaplen = res;
2348
2349 if (sk->sk_type == SOCK_DGRAM) {
2350 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2351 po->tp_reserve;
2352 } else {
2353 unsigned int maclen = skb_network_offset(skb);
2354 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2355 (maclen < 16 ? 16 : maclen)) +
2356 po->tp_reserve;
2357 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2358 if (vnet_hdr_sz)
2359 netoff += vnet_hdr_sz;
2360 macoff = netoff - maclen;
2361 }
2362 if (netoff > USHRT_MAX) {
2363 atomic_inc(&po->tp_drops);
2364 goto drop_n_restore;
2365 }
2366 if (po->tp_version <= TPACKET_V2) {
2367 if (macoff + snaplen > po->rx_ring.frame_size) {
2368 if (READ_ONCE(po->copy_thresh) &&
2369 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2370 if (skb_shared(skb)) {
2371 copy_skb = skb_clone(skb, GFP_ATOMIC);
2372 } else {
2373 copy_skb = skb_get(skb);
2374 skb_head = skb->data;
2375 }
2376 if (copy_skb) {
2377 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0,
2378 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll));
2379 skb_set_owner_r(copy_skb, sk);
2380 }
2381 }
2382 snaplen = po->rx_ring.frame_size - macoff;
2383 if ((int)snaplen < 0) {
2384 snaplen = 0;
2385 vnet_hdr_sz = 0;
2386 }
2387 }
2388 } else if (unlikely(macoff + snaplen >
2389 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2390 u32 nval;
2391
2392 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2393 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2394 snaplen, nval, macoff);
2395 snaplen = nval;
2396 if (unlikely((int)snaplen < 0)) {
2397 snaplen = 0;
2398 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2399 vnet_hdr_sz = 0;
2400 }
2401 }
2402 spin_lock(&sk->sk_receive_queue.lock);
2403 h.raw = packet_current_rx_frame(po, skb,
2404 TP_STATUS_KERNEL, (macoff+snaplen));
2405 if (!h.raw)
2406 goto drop_n_account;
2407
2408 if (po->tp_version <= TPACKET_V2) {
2409 slot_id = po->rx_ring.head;
2410 if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2411 goto drop_n_account;
2412 __set_bit(slot_id, po->rx_ring.rx_owner_map);
2413 }
2414
2415 if (vnet_hdr_sz &&
2416 virtio_net_hdr_from_skb(skb, h.raw + macoff -
2417 sizeof(struct virtio_net_hdr),
2418 vio_le(), true, 0)) {
2419 if (po->tp_version == TPACKET_V3)
2420 prb_clear_blk_fill_status(&po->rx_ring);
2421 goto drop_n_account;
2422 }
2423
2424 if (po->tp_version <= TPACKET_V2) {
2425 packet_increment_rx_head(po, &po->rx_ring);
2426 /*
2427 * LOSING will be reported till you read the stats,
2428 * because it's COR - Clear On Read.
2429 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2430 * at packet level.
2431 */
2432 if (atomic_read(&po->tp_drops))
2433 status |= TP_STATUS_LOSING;
2434 }
2435
2436 po->stats.stats1.tp_packets++;
2437 if (copy_skb) {
2438 status |= TP_STATUS_COPY;
2439 skb_clear_delivery_time(copy_skb);
2440 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2441 }
2442 spin_unlock(&sk->sk_receive_queue.lock);
2443
2444 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2445
2446 /* Always timestamp; prefer an existing software timestamp taken
2447 * closer to the time of capture.
2448 */
2449 ts_status = tpacket_get_timestamp(skb, &ts,
2450 READ_ONCE(po->tp_tstamp) |
2451 SOF_TIMESTAMPING_SOFTWARE);
2452 if (!ts_status)
2453 ktime_get_real_ts64(&ts);
2454
2455 status |= ts_status;
2456
2457 switch (po->tp_version) {
2458 case TPACKET_V1:
2459 h.h1->tp_len = skb->len;
2460 h.h1->tp_snaplen = snaplen;
2461 h.h1->tp_mac = macoff;
2462 h.h1->tp_net = netoff;
2463 h.h1->tp_sec = ts.tv_sec;
2464 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2465 hdrlen = sizeof(*h.h1);
2466 break;
2467 case TPACKET_V2:
2468 h.h2->tp_len = skb->len;
2469 h.h2->tp_snaplen = snaplen;
2470 h.h2->tp_mac = macoff;
2471 h.h2->tp_net = netoff;
2472 h.h2->tp_sec = ts.tv_sec;
2473 h.h2->tp_nsec = ts.tv_nsec;
2474 if (skb_vlan_tag_present(skb)) {
2475 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2476 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2477 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2478 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) {
2479 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev);
2480 h.h2->tp_vlan_tpid = ntohs(skb->protocol);
2481 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2482 } else {
2483 h.h2->tp_vlan_tci = 0;
2484 h.h2->tp_vlan_tpid = 0;
2485 }
2486 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2487 hdrlen = sizeof(*h.h2);
2488 break;
2489 case TPACKET_V3:
2490 /* tp_nxt_offset,vlan are already populated above.
2491 * So DONT clear those fields here
2492 */
2493 h.h3->tp_status |= status;
2494 h.h3->tp_len = skb->len;
2495 h.h3->tp_snaplen = snaplen;
2496 h.h3->tp_mac = macoff;
2497 h.h3->tp_net = netoff;
2498 h.h3->tp_sec = ts.tv_sec;
2499 h.h3->tp_nsec = ts.tv_nsec;
2500 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2501 hdrlen = sizeof(*h.h3);
2502 break;
2503 default:
2504 BUG();
2505 }
2506
2507 sll = h.raw + TPACKET_ALIGN(hdrlen);
2508 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2509 sll->sll_family = AF_PACKET;
2510 sll->sll_hatype = dev->type;
2511 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ?
2512 vlan_get_protocol_dgram(skb) : skb->protocol;
2513 sll->sll_pkttype = skb->pkt_type;
2514 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
2515 sll->sll_ifindex = orig_dev->ifindex;
2516 else
2517 sll->sll_ifindex = dev->ifindex;
2518
2519 smp_mb();
2520
2521#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2522 if (po->tp_version <= TPACKET_V2) {
2523 u8 *start, *end;
2524
2525 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2526 macoff + snaplen);
2527
2528 for (start = h.raw; start < end; start += PAGE_SIZE)
2529 flush_dcache_page(pgv_to_page(start));
2530 }
2531 smp_wmb();
2532#endif
2533
2534 if (po->tp_version <= TPACKET_V2) {
2535 spin_lock(&sk->sk_receive_queue.lock);
2536 __packet_set_status(po, h.raw, status);
2537 __clear_bit(slot_id, po->rx_ring.rx_owner_map);
2538 spin_unlock(&sk->sk_receive_queue.lock);
2539 sk->sk_data_ready(sk);
2540 } else if (po->tp_version == TPACKET_V3) {
2541 prb_clear_blk_fill_status(&po->rx_ring);
2542 }
2543
2544drop_n_restore:
2545 if (skb_head != skb->data && skb_shared(skb)) {
2546 skb->data = skb_head;
2547 skb->len = skb_len;
2548 }
2549drop:
2550 sk_skb_reason_drop(sk, skb, drop_reason);
2551 return 0;
2552
2553drop_n_account:
2554 spin_unlock(&sk->sk_receive_queue.lock);
2555 atomic_inc(&po->tp_drops);
2556 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR;
2557
2558 sk->sk_data_ready(sk);
2559 sk_skb_reason_drop(sk, copy_skb, drop_reason);
2560 goto drop_n_restore;
2561}
2562
2563static void tpacket_destruct_skb(struct sk_buff *skb)
2564{
2565 struct packet_sock *po = pkt_sk(skb->sk);
2566
2567 if (likely(po->tx_ring.pg_vec)) {
2568 void *ph;
2569 __u32 ts;
2570
2571 ph = skb_zcopy_get_nouarg(skb);
2572 packet_dec_pending(&po->tx_ring);
2573
2574 ts = __packet_set_timestamp(po, ph, skb);
2575 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2576
2577 complete(&po->skb_completion);
2578 }
2579
2580 sock_wfree(skb);
2581}
2582
2583static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2584{
2585 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2586 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2587 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2588 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2589 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2590 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2591 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2592
2593 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2594 return -EINVAL;
2595
2596 return 0;
2597}
2598
2599static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2600 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz)
2601{
2602 int ret;
2603
2604 if (*len < vnet_hdr_sz)
2605 return -EINVAL;
2606 *len -= vnet_hdr_sz;
2607
2608 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2609 return -EFAULT;
2610
2611 ret = __packet_snd_vnet_parse(vnet_hdr, *len);
2612 if (ret)
2613 return ret;
2614
2615 /* move iter to point to the start of mac header */
2616 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr))
2617 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr));
2618
2619 return 0;
2620}
2621
2622static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2623 void *frame, struct net_device *dev, void *data, int tp_len,
2624 __be16 proto, unsigned char *addr, int hlen, int copylen,
2625 const struct sockcm_cookie *sockc)
2626{
2627 union tpacket_uhdr ph;
2628 int to_write, offset, len, nr_frags, len_max;
2629 struct socket *sock = po->sk.sk_socket;
2630 struct page *page;
2631 int err;
2632
2633 ph.raw = frame;
2634
2635 skb->protocol = proto;
2636 skb->dev = dev;
2637 skb->priority = READ_ONCE(po->sk.sk_priority);
2638 skb->mark = READ_ONCE(po->sk.sk_mark);
2639 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid);
2640 skb_setup_tx_timestamp(skb, sockc);
2641 skb_zcopy_set_nouarg(skb, ph.raw);
2642
2643 skb_reserve(skb, hlen);
2644 skb_reset_network_header(skb);
2645
2646 to_write = tp_len;
2647
2648 if (sock->type == SOCK_DGRAM) {
2649 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2650 NULL, tp_len);
2651 if (unlikely(err < 0))
2652 return -EINVAL;
2653 } else if (copylen) {
2654 int hdrlen = min_t(int, copylen, tp_len);
2655
2656 skb_push(skb, dev->hard_header_len);
2657 skb_put(skb, copylen - dev->hard_header_len);
2658 err = skb_store_bits(skb, 0, data, hdrlen);
2659 if (unlikely(err))
2660 return err;
2661 if (!dev_validate_header(dev, skb->data, hdrlen))
2662 return -EINVAL;
2663
2664 data += hdrlen;
2665 to_write -= hdrlen;
2666 }
2667
2668 offset = offset_in_page(data);
2669 len_max = PAGE_SIZE - offset;
2670 len = ((to_write > len_max) ? len_max : to_write);
2671
2672 skb->data_len = to_write;
2673 skb->len += to_write;
2674 skb->truesize += to_write;
2675 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2676
2677 while (likely(to_write)) {
2678 nr_frags = skb_shinfo(skb)->nr_frags;
2679
2680 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2681 pr_err("Packet exceed the number of skb frags(%u)\n",
2682 (unsigned int)MAX_SKB_FRAGS);
2683 return -EFAULT;
2684 }
2685
2686 page = pgv_to_page(data);
2687 data += len;
2688 flush_dcache_page(page);
2689 get_page(page);
2690 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2691 to_write -= len;
2692 offset = 0;
2693 len_max = PAGE_SIZE;
2694 len = ((to_write > len_max) ? len_max : to_write);
2695 }
2696
2697 packet_parse_headers(skb, sock);
2698
2699 return tp_len;
2700}
2701
2702static int tpacket_parse_header(struct packet_sock *po, void *frame,
2703 int size_max, void **data)
2704{
2705 union tpacket_uhdr ph;
2706 int tp_len, off;
2707
2708 ph.raw = frame;
2709
2710 switch (po->tp_version) {
2711 case TPACKET_V3:
2712 if (ph.h3->tp_next_offset != 0) {
2713 pr_warn_once("variable sized slot not supported");
2714 return -EINVAL;
2715 }
2716 tp_len = ph.h3->tp_len;
2717 break;
2718 case TPACKET_V2:
2719 tp_len = ph.h2->tp_len;
2720 break;
2721 default:
2722 tp_len = ph.h1->tp_len;
2723 break;
2724 }
2725 if (unlikely(tp_len > size_max)) {
2726 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2727 return -EMSGSIZE;
2728 }
2729
2730 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) {
2731 int off_min, off_max;
2732
2733 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2734 off_max = po->tx_ring.frame_size - tp_len;
2735 if (po->sk.sk_type == SOCK_DGRAM) {
2736 switch (po->tp_version) {
2737 case TPACKET_V3:
2738 off = ph.h3->tp_net;
2739 break;
2740 case TPACKET_V2:
2741 off = ph.h2->tp_net;
2742 break;
2743 default:
2744 off = ph.h1->tp_net;
2745 break;
2746 }
2747 } else {
2748 switch (po->tp_version) {
2749 case TPACKET_V3:
2750 off = ph.h3->tp_mac;
2751 break;
2752 case TPACKET_V2:
2753 off = ph.h2->tp_mac;
2754 break;
2755 default:
2756 off = ph.h1->tp_mac;
2757 break;
2758 }
2759 }
2760 if (unlikely((off < off_min) || (off_max < off)))
2761 return -EINVAL;
2762 } else {
2763 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2764 }
2765
2766 *data = frame + off;
2767 return tp_len;
2768}
2769
2770static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2771{
2772 struct sk_buff *skb = NULL;
2773 struct net_device *dev;
2774 struct virtio_net_hdr *vnet_hdr = NULL;
2775 struct sockcm_cookie sockc;
2776 __be16 proto;
2777 int err, reserve = 0;
2778 void *ph;
2779 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2780 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2781 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2782 unsigned char *addr = NULL;
2783 int tp_len, size_max;
2784 void *data;
2785 int len_sum = 0;
2786 int status = TP_STATUS_AVAILABLE;
2787 int hlen, tlen, copylen = 0;
2788 long timeo = 0;
2789
2790 mutex_lock(&po->pg_vec_lock);
2791
2792 /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2793 * we need to confirm it under protection of pg_vec_lock.
2794 */
2795 if (unlikely(!po->tx_ring.pg_vec)) {
2796 err = -EBUSY;
2797 goto out;
2798 }
2799 if (likely(saddr == NULL)) {
2800 dev = packet_cached_dev_get(po);
2801 proto = READ_ONCE(po->num);
2802 } else {
2803 err = -EINVAL;
2804 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2805 goto out;
2806 if (msg->msg_namelen < (saddr->sll_halen
2807 + offsetof(struct sockaddr_ll,
2808 sll_addr)))
2809 goto out;
2810 proto = saddr->sll_protocol;
2811 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2812 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2813 if (dev && msg->msg_namelen < dev->addr_len +
2814 offsetof(struct sockaddr_ll, sll_addr))
2815 goto out_put;
2816 addr = saddr->sll_addr;
2817 }
2818 }
2819
2820 err = -ENXIO;
2821 if (unlikely(dev == NULL))
2822 goto out;
2823 err = -ENETDOWN;
2824 if (unlikely(!(dev->flags & IFF_UP)))
2825 goto out_put;
2826
2827 sockcm_init(&sockc, &po->sk);
2828 if (msg->msg_controllen) {
2829 err = sock_cmsg_send(&po->sk, msg, &sockc);
2830 if (unlikely(err))
2831 goto out_put;
2832 }
2833
2834 if (po->sk.sk_socket->type == SOCK_RAW)
2835 reserve = dev->hard_header_len;
2836 size_max = po->tx_ring.frame_size
2837 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2838
2839 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz)
2840 size_max = dev->mtu + reserve + VLAN_HLEN;
2841
2842 reinit_completion(&po->skb_completion);
2843
2844 do {
2845 ph = packet_current_frame(po, &po->tx_ring,
2846 TP_STATUS_SEND_REQUEST);
2847 if (unlikely(ph == NULL)) {
2848 if (need_wait && skb) {
2849 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2850 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2851 if (timeo <= 0) {
2852 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2853 goto out_put;
2854 }
2855 }
2856 /* check for additional frames */
2857 continue;
2858 }
2859
2860 skb = NULL;
2861 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2862 if (tp_len < 0)
2863 goto tpacket_error;
2864
2865 status = TP_STATUS_SEND_REQUEST;
2866 hlen = LL_RESERVED_SPACE(dev);
2867 tlen = dev->needed_tailroom;
2868 if (vnet_hdr_sz) {
2869 vnet_hdr = data;
2870 data += vnet_hdr_sz;
2871 tp_len -= vnet_hdr_sz;
2872 if (tp_len < 0 ||
2873 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2874 tp_len = -EINVAL;
2875 goto tpacket_error;
2876 }
2877 copylen = __virtio16_to_cpu(vio_le(),
2878 vnet_hdr->hdr_len);
2879 }
2880 copylen = max_t(int, copylen, dev->hard_header_len);
2881 skb = sock_alloc_send_skb(&po->sk,
2882 hlen + tlen + sizeof(struct sockaddr_ll) +
2883 (copylen - dev->hard_header_len),
2884 !need_wait, &err);
2885
2886 if (unlikely(skb == NULL)) {
2887 /* we assume the socket was initially writeable ... */
2888 if (likely(len_sum > 0))
2889 err = len_sum;
2890 goto out_status;
2891 }
2892 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2893 addr, hlen, copylen, &sockc);
2894 if (likely(tp_len >= 0) &&
2895 tp_len > dev->mtu + reserve &&
2896 !vnet_hdr_sz &&
2897 !packet_extra_vlan_len_allowed(dev, skb))
2898 tp_len = -EMSGSIZE;
2899
2900 if (unlikely(tp_len < 0)) {
2901tpacket_error:
2902 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) {
2903 __packet_set_status(po, ph,
2904 TP_STATUS_AVAILABLE);
2905 packet_increment_head(&po->tx_ring);
2906 kfree_skb(skb);
2907 continue;
2908 } else {
2909 status = TP_STATUS_WRONG_FORMAT;
2910 err = tp_len;
2911 goto out_status;
2912 }
2913 }
2914
2915 if (vnet_hdr_sz) {
2916 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2917 tp_len = -EINVAL;
2918 goto tpacket_error;
2919 }
2920 virtio_net_hdr_set_proto(skb, vnet_hdr);
2921 }
2922
2923 skb->destructor = tpacket_destruct_skb;
2924 __packet_set_status(po, ph, TP_STATUS_SENDING);
2925 packet_inc_pending(&po->tx_ring);
2926
2927 status = TP_STATUS_SEND_REQUEST;
2928 err = packet_xmit(po, skb);
2929 if (unlikely(err != 0)) {
2930 if (err > 0)
2931 err = net_xmit_errno(err);
2932 if (err && __packet_get_status(po, ph) ==
2933 TP_STATUS_AVAILABLE) {
2934 /* skb was destructed already */
2935 skb = NULL;
2936 goto out_status;
2937 }
2938 /*
2939 * skb was dropped but not destructed yet;
2940 * let's treat it like congestion or err < 0
2941 */
2942 err = 0;
2943 }
2944 packet_increment_head(&po->tx_ring);
2945 len_sum += tp_len;
2946 } while (likely((ph != NULL) ||
2947 /* Note: packet_read_pending() might be slow if we have
2948 * to call it as it's per_cpu variable, but in fast-path
2949 * we already short-circuit the loop with the first
2950 * condition, and luckily don't have to go that path
2951 * anyway.
2952 */
2953 (need_wait && packet_read_pending(&po->tx_ring))));
2954
2955 err = len_sum;
2956 goto out_put;
2957
2958out_status:
2959 __packet_set_status(po, ph, status);
2960 kfree_skb(skb);
2961out_put:
2962 dev_put(dev);
2963out:
2964 mutex_unlock(&po->pg_vec_lock);
2965 return err;
2966}
2967
2968static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2969 size_t reserve, size_t len,
2970 size_t linear, int noblock,
2971 int *err)
2972{
2973 struct sk_buff *skb;
2974
2975 /* Under a page? Don't bother with paged skb. */
2976 if (prepad + len < PAGE_SIZE || !linear)
2977 linear = len;
2978
2979 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
2980 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER);
2981 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2982 err, PAGE_ALLOC_COSTLY_ORDER);
2983 if (!skb)
2984 return NULL;
2985
2986 skb_reserve(skb, reserve);
2987 skb_put(skb, linear);
2988 skb->data_len = len - linear;
2989 skb->len += len - linear;
2990
2991 return skb;
2992}
2993
2994static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2995{
2996 struct sock *sk = sock->sk;
2997 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2998 struct sk_buff *skb;
2999 struct net_device *dev;
3000 __be16 proto;
3001 unsigned char *addr = NULL;
3002 int err, reserve = 0;
3003 struct sockcm_cookie sockc;
3004 struct virtio_net_hdr vnet_hdr = { 0 };
3005 int offset = 0;
3006 struct packet_sock *po = pkt_sk(sk);
3007 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
3008 int hlen, tlen, linear;
3009 int extra_len = 0;
3010
3011 /*
3012 * Get and verify the address.
3013 */
3014
3015 if (likely(saddr == NULL)) {
3016 dev = packet_cached_dev_get(po);
3017 proto = READ_ONCE(po->num);
3018 } else {
3019 err = -EINVAL;
3020 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
3021 goto out;
3022 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
3023 goto out;
3024 proto = saddr->sll_protocol;
3025 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
3026 if (sock->type == SOCK_DGRAM) {
3027 if (dev && msg->msg_namelen < dev->addr_len +
3028 offsetof(struct sockaddr_ll, sll_addr))
3029 goto out_unlock;
3030 addr = saddr->sll_addr;
3031 }
3032 }
3033
3034 err = -ENXIO;
3035 if (unlikely(dev == NULL))
3036 goto out_unlock;
3037 err = -ENETDOWN;
3038 if (unlikely(!(dev->flags & IFF_UP)))
3039 goto out_unlock;
3040
3041 sockcm_init(&sockc, sk);
3042 sockc.mark = READ_ONCE(sk->sk_mark);
3043 if (msg->msg_controllen) {
3044 err = sock_cmsg_send(sk, msg, &sockc);
3045 if (unlikely(err))
3046 goto out_unlock;
3047 }
3048
3049 if (sock->type == SOCK_RAW)
3050 reserve = dev->hard_header_len;
3051 if (vnet_hdr_sz) {
3052 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz);
3053 if (err)
3054 goto out_unlock;
3055 }
3056
3057 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
3058 if (!netif_supports_nofcs(dev)) {
3059 err = -EPROTONOSUPPORT;
3060 goto out_unlock;
3061 }
3062 extra_len = 4; /* We're doing our own CRC */
3063 }
3064
3065 err = -EMSGSIZE;
3066 if (!vnet_hdr.gso_type &&
3067 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
3068 goto out_unlock;
3069
3070 err = -ENOBUFS;
3071 hlen = LL_RESERVED_SPACE(dev);
3072 tlen = dev->needed_tailroom;
3073 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
3074 linear = max(linear, min_t(int, len, dev->hard_header_len));
3075 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
3076 msg->msg_flags & MSG_DONTWAIT, &err);
3077 if (skb == NULL)
3078 goto out_unlock;
3079
3080 skb_reset_network_header(skb);
3081
3082 err = -EINVAL;
3083 if (sock->type == SOCK_DGRAM) {
3084 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
3085 if (unlikely(offset < 0))
3086 goto out_free;
3087 } else if (reserve) {
3088 skb_reserve(skb, -reserve);
3089 if (len < reserve + sizeof(struct ipv6hdr) &&
3090 dev->min_header_len != dev->hard_header_len)
3091 skb_reset_network_header(skb);
3092 }
3093
3094 /* Returns -EFAULT on error */
3095 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
3096 if (err)
3097 goto out_free;
3098
3099 if ((sock->type == SOCK_RAW &&
3100 !dev_validate_header(dev, skb->data, len)) || !skb->len) {
3101 err = -EINVAL;
3102 goto out_free;
3103 }
3104
3105 skb_setup_tx_timestamp(skb, &sockc);
3106
3107 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
3108 !packet_extra_vlan_len_allowed(dev, skb)) {
3109 err = -EMSGSIZE;
3110 goto out_free;
3111 }
3112
3113 skb->protocol = proto;
3114 skb->dev = dev;
3115 skb->priority = READ_ONCE(sk->sk_priority);
3116 skb->mark = sockc.mark;
3117 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid);
3118
3119 if (unlikely(extra_len == 4))
3120 skb->no_fcs = 1;
3121
3122 packet_parse_headers(skb, sock);
3123
3124 if (vnet_hdr_sz) {
3125 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
3126 if (err)
3127 goto out_free;
3128 len += vnet_hdr_sz;
3129 virtio_net_hdr_set_proto(skb, &vnet_hdr);
3130 }
3131
3132 err = packet_xmit(po, skb);
3133
3134 if (unlikely(err != 0)) {
3135 if (err > 0)
3136 err = net_xmit_errno(err);
3137 if (err)
3138 goto out_unlock;
3139 }
3140
3141 dev_put(dev);
3142
3143 return len;
3144
3145out_free:
3146 kfree_skb(skb);
3147out_unlock:
3148 dev_put(dev);
3149out:
3150 return err;
3151}
3152
3153static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3154{
3155 struct sock *sk = sock->sk;
3156 struct packet_sock *po = pkt_sk(sk);
3157
3158 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
3159 * tpacket_snd() will redo the check safely.
3160 */
3161 if (data_race(po->tx_ring.pg_vec))
3162 return tpacket_snd(po, msg);
3163
3164 return packet_snd(sock, msg, len);
3165}
3166
3167/*
3168 * Close a PACKET socket. This is fairly simple. We immediately go
3169 * to 'closed' state and remove our protocol entry in the device list.
3170 */
3171
3172static int packet_release(struct socket *sock)
3173{
3174 struct sock *sk = sock->sk;
3175 struct packet_sock *po;
3176 struct packet_fanout *f;
3177 struct net *net;
3178 union tpacket_req_u req_u;
3179
3180 if (!sk)
3181 return 0;
3182
3183 net = sock_net(sk);
3184 po = pkt_sk(sk);
3185
3186 mutex_lock(&net->packet.sklist_lock);
3187 sk_del_node_init_rcu(sk);
3188 mutex_unlock(&net->packet.sklist_lock);
3189
3190 sock_prot_inuse_add(net, sk->sk_prot, -1);
3191
3192 spin_lock(&po->bind_lock);
3193 unregister_prot_hook(sk, false);
3194 packet_cached_dev_reset(po);
3195
3196 if (po->prot_hook.dev) {
3197 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3198 po->prot_hook.dev = NULL;
3199 }
3200 spin_unlock(&po->bind_lock);
3201
3202 packet_flush_mclist(sk);
3203
3204 lock_sock(sk);
3205 if (po->rx_ring.pg_vec) {
3206 memset(&req_u, 0, sizeof(req_u));
3207 packet_set_ring(sk, &req_u, 1, 0);
3208 }
3209
3210 if (po->tx_ring.pg_vec) {
3211 memset(&req_u, 0, sizeof(req_u));
3212 packet_set_ring(sk, &req_u, 1, 1);
3213 }
3214 release_sock(sk);
3215
3216 f = fanout_release(sk);
3217
3218 synchronize_net();
3219
3220 kfree(po->rollover);
3221 if (f) {
3222 fanout_release_data(f);
3223 kvfree(f);
3224 }
3225 /*
3226 * Now the socket is dead. No more input will appear.
3227 */
3228 sock_orphan(sk);
3229 sock->sk = NULL;
3230
3231 /* Purge queues */
3232
3233 skb_queue_purge(&sk->sk_receive_queue);
3234 packet_free_pending(po);
3235
3236 sock_put(sk);
3237 return 0;
3238}
3239
3240/*
3241 * Attach a packet hook.
3242 */
3243
3244static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3245 __be16 proto)
3246{
3247 struct packet_sock *po = pkt_sk(sk);
3248 struct net_device *dev = NULL;
3249 bool unlisted = false;
3250 bool need_rehook;
3251 int ret = 0;
3252
3253 lock_sock(sk);
3254 spin_lock(&po->bind_lock);
3255 if (!proto)
3256 proto = po->num;
3257
3258 rcu_read_lock();
3259
3260 if (po->fanout) {
3261 ret = -EINVAL;
3262 goto out_unlock;
3263 }
3264
3265 if (name) {
3266 dev = dev_get_by_name_rcu(sock_net(sk), name);
3267 if (!dev) {
3268 ret = -ENODEV;
3269 goto out_unlock;
3270 }
3271 } else if (ifindex) {
3272 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3273 if (!dev) {
3274 ret = -ENODEV;
3275 goto out_unlock;
3276 }
3277 }
3278
3279 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev;
3280
3281 if (need_rehook) {
3282 dev_hold(dev);
3283 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
3284 rcu_read_unlock();
3285 /* prevents packet_notifier() from calling
3286 * register_prot_hook()
3287 */
3288 WRITE_ONCE(po->num, 0);
3289 __unregister_prot_hook(sk, true);
3290 rcu_read_lock();
3291 if (dev)
3292 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3293 dev->ifindex);
3294 }
3295
3296 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING));
3297 WRITE_ONCE(po->num, proto);
3298 po->prot_hook.type = proto;
3299
3300 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3301
3302 if (unlikely(unlisted)) {
3303 po->prot_hook.dev = NULL;
3304 WRITE_ONCE(po->ifindex, -1);
3305 packet_cached_dev_reset(po);
3306 } else {
3307 netdev_hold(dev, &po->prot_hook.dev_tracker,
3308 GFP_ATOMIC);
3309 po->prot_hook.dev = dev;
3310 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
3311 packet_cached_dev_assign(po, dev);
3312 }
3313 dev_put(dev);
3314 }
3315
3316 if (proto == 0 || !need_rehook)
3317 goto out_unlock;
3318
3319 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3320 register_prot_hook(sk);
3321 } else {
3322 sk->sk_err = ENETDOWN;
3323 if (!sock_flag(sk, SOCK_DEAD))
3324 sk_error_report(sk);
3325 }
3326
3327out_unlock:
3328 rcu_read_unlock();
3329 spin_unlock(&po->bind_lock);
3330 release_sock(sk);
3331 return ret;
3332}
3333
3334/*
3335 * Bind a packet socket to a device
3336 */
3337
3338static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3339 int addr_len)
3340{
3341 struct sock *sk = sock->sk;
3342 char name[sizeof(uaddr->sa_data_min) + 1];
3343
3344 /*
3345 * Check legality
3346 */
3347
3348 if (addr_len != sizeof(struct sockaddr))
3349 return -EINVAL;
3350 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3351 * zero-terminated.
3352 */
3353 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min));
3354 name[sizeof(uaddr->sa_data_min)] = 0;
3355
3356 return packet_do_bind(sk, name, 0, 0);
3357}
3358
3359static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3360{
3361 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3362 struct sock *sk = sock->sk;
3363
3364 /*
3365 * Check legality
3366 */
3367
3368 if (addr_len < sizeof(struct sockaddr_ll))
3369 return -EINVAL;
3370 if (sll->sll_family != AF_PACKET)
3371 return -EINVAL;
3372
3373 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol);
3374}
3375
3376static struct proto packet_proto = {
3377 .name = "PACKET",
3378 .owner = THIS_MODULE,
3379 .obj_size = sizeof(struct packet_sock),
3380};
3381
3382/*
3383 * Create a packet of type SOCK_PACKET.
3384 */
3385
3386static int packet_create(struct net *net, struct socket *sock, int protocol,
3387 int kern)
3388{
3389 struct sock *sk;
3390 struct packet_sock *po;
3391 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3392 int err;
3393
3394 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3395 return -EPERM;
3396 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3397 sock->type != SOCK_PACKET)
3398 return -ESOCKTNOSUPPORT;
3399
3400 sock->state = SS_UNCONNECTED;
3401
3402 err = -ENOBUFS;
3403 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3404 if (sk == NULL)
3405 goto out;
3406
3407 sock->ops = &packet_ops;
3408 if (sock->type == SOCK_PACKET)
3409 sock->ops = &packet_ops_spkt;
3410
3411 po = pkt_sk(sk);
3412 err = packet_alloc_pending(po);
3413 if (err)
3414 goto out_sk_free;
3415
3416 sock_init_data(sock, sk);
3417
3418 init_completion(&po->skb_completion);
3419 sk->sk_family = PF_PACKET;
3420 po->num = proto;
3421
3422 packet_cached_dev_reset(po);
3423
3424 sk->sk_destruct = packet_sock_destruct;
3425
3426 /*
3427 * Attach a protocol block
3428 */
3429
3430 spin_lock_init(&po->bind_lock);
3431 mutex_init(&po->pg_vec_lock);
3432 po->rollover = NULL;
3433 po->prot_hook.func = packet_rcv;
3434
3435 if (sock->type == SOCK_PACKET)
3436 po->prot_hook.func = packet_rcv_spkt;
3437
3438 po->prot_hook.af_packet_priv = sk;
3439 po->prot_hook.af_packet_net = sock_net(sk);
3440
3441 if (proto) {
3442 po->prot_hook.type = proto;
3443 __register_prot_hook(sk);
3444 }
3445
3446 mutex_lock(&net->packet.sklist_lock);
3447 sk_add_node_tail_rcu(sk, &net->packet.sklist);
3448 mutex_unlock(&net->packet.sklist_lock);
3449
3450 sock_prot_inuse_add(net, &packet_proto, 1);
3451
3452 return 0;
3453out_sk_free:
3454 sk_free(sk);
3455out:
3456 return err;
3457}
3458
3459/*
3460 * Pull a packet from our receive queue and hand it to the user.
3461 * If necessary we block.
3462 */
3463
3464static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3465 int flags)
3466{
3467 struct sock *sk = sock->sk;
3468 struct sk_buff *skb;
3469 int copied, err;
3470 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz);
3471 unsigned int origlen = 0;
3472
3473 err = -EINVAL;
3474 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3475 goto out;
3476
3477#if 0
3478 /* What error should we return now? EUNATTACH? */
3479 if (pkt_sk(sk)->ifindex < 0)
3480 return -ENODEV;
3481#endif
3482
3483 if (flags & MSG_ERRQUEUE) {
3484 err = sock_recv_errqueue(sk, msg, len,
3485 SOL_PACKET, PACKET_TX_TIMESTAMP);
3486 goto out;
3487 }
3488
3489 /*
3490 * Call the generic datagram receiver. This handles all sorts
3491 * of horrible races and re-entrancy so we can forget about it
3492 * in the protocol layers.
3493 *
3494 * Now it will return ENETDOWN, if device have just gone down,
3495 * but then it will block.
3496 */
3497
3498 skb = skb_recv_datagram(sk, flags, &err);
3499
3500 /*
3501 * An error occurred so return it. Because skb_recv_datagram()
3502 * handles the blocking we don't see and worry about blocking
3503 * retries.
3504 */
3505
3506 if (skb == NULL)
3507 goto out;
3508
3509 packet_rcv_try_clear_pressure(pkt_sk(sk));
3510
3511 if (vnet_hdr_len) {
3512 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len);
3513 if (err)
3514 goto out_free;
3515 }
3516
3517 /* You lose any data beyond the buffer you gave. If it worries
3518 * a user program they can ask the device for its MTU
3519 * anyway.
3520 */
3521 copied = skb->len;
3522 if (copied > len) {
3523 copied = len;
3524 msg->msg_flags |= MSG_TRUNC;
3525 }
3526
3527 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3528 if (err)
3529 goto out_free;
3530
3531 if (sock->type != SOCK_PACKET) {
3532 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3533
3534 /* Original length was stored in sockaddr_ll fields */
3535 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3536 sll->sll_family = AF_PACKET;
3537 sll->sll_protocol = (sock->type == SOCK_DGRAM) ?
3538 vlan_get_protocol_dgram(skb) : skb->protocol;
3539 }
3540
3541 sock_recv_cmsgs(msg, sk, skb);
3542
3543 if (msg->msg_name) {
3544 const size_t max_len = min(sizeof(skb->cb),
3545 sizeof(struct sockaddr_storage));
3546 int copy_len;
3547
3548 /* If the address length field is there to be filled
3549 * in, we fill it in now.
3550 */
3551 if (sock->type == SOCK_PACKET) {
3552 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3553 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3554 copy_len = msg->msg_namelen;
3555 } else {
3556 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3557
3558 msg->msg_namelen = sll->sll_halen +
3559 offsetof(struct sockaddr_ll, sll_addr);
3560 copy_len = msg->msg_namelen;
3561 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3562 memset(msg->msg_name +
3563 offsetof(struct sockaddr_ll, sll_addr),
3564 0, sizeof(sll->sll_addr));
3565 msg->msg_namelen = sizeof(struct sockaddr_ll);
3566 }
3567 }
3568 if (WARN_ON_ONCE(copy_len > max_len)) {
3569 copy_len = max_len;
3570 msg->msg_namelen = copy_len;
3571 }
3572 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3573 }
3574
3575 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) {
3576 struct tpacket_auxdata aux;
3577
3578 aux.tp_status = TP_STATUS_USER;
3579 if (skb->ip_summed == CHECKSUM_PARTIAL)
3580 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3581 else if (skb->pkt_type != PACKET_OUTGOING &&
3582 skb_csum_unnecessary(skb))
3583 aux.tp_status |= TP_STATUS_CSUM_VALID;
3584 if (skb_is_gso(skb) && skb_is_gso_tcp(skb))
3585 aux.tp_status |= TP_STATUS_GSO_TCP;
3586
3587 aux.tp_len = origlen;
3588 aux.tp_snaplen = skb->len;
3589 aux.tp_mac = 0;
3590 aux.tp_net = skb_network_offset(skb);
3591 if (skb_vlan_tag_present(skb)) {
3592 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3593 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3594 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3595 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) {
3596 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3597 struct net_device *dev;
3598
3599 rcu_read_lock();
3600 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex);
3601 if (dev) {
3602 aux.tp_vlan_tci = vlan_get_tci(skb, dev);
3603 aux.tp_vlan_tpid = ntohs(skb->protocol);
3604 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3605 } else {
3606 aux.tp_vlan_tci = 0;
3607 aux.tp_vlan_tpid = 0;
3608 }
3609 rcu_read_unlock();
3610 } else {
3611 aux.tp_vlan_tci = 0;
3612 aux.tp_vlan_tpid = 0;
3613 }
3614 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3615 }
3616
3617 /*
3618 * Free or return the buffer as appropriate. Again this
3619 * hides all the races and re-entrancy issues from us.
3620 */
3621 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3622
3623out_free:
3624 skb_free_datagram(sk, skb);
3625out:
3626 return err;
3627}
3628
3629static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3630 int peer)
3631{
3632 struct net_device *dev;
3633 struct sock *sk = sock->sk;
3634
3635 if (peer)
3636 return -EOPNOTSUPP;
3637
3638 uaddr->sa_family = AF_PACKET;
3639 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min));
3640 rcu_read_lock();
3641 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
3642 if (dev)
3643 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min));
3644 rcu_read_unlock();
3645
3646 return sizeof(*uaddr);
3647}
3648
3649static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3650 int peer)
3651{
3652 struct net_device *dev;
3653 struct sock *sk = sock->sk;
3654 struct packet_sock *po = pkt_sk(sk);
3655 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3656 int ifindex;
3657
3658 if (peer)
3659 return -EOPNOTSUPP;
3660
3661 ifindex = READ_ONCE(po->ifindex);
3662 sll->sll_family = AF_PACKET;
3663 sll->sll_ifindex = ifindex;
3664 sll->sll_protocol = READ_ONCE(po->num);
3665 sll->sll_pkttype = 0;
3666 rcu_read_lock();
3667 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3668 if (dev) {
3669 sll->sll_hatype = dev->type;
3670 sll->sll_halen = dev->addr_len;
3671
3672 /* Let __fortify_memcpy_chk() know the actual buffer size. */
3673 memcpy(((struct sockaddr_storage *)sll)->__data +
3674 offsetof(struct sockaddr_ll, sll_addr) -
3675 offsetofend(struct sockaddr_ll, sll_family),
3676 dev->dev_addr, dev->addr_len);
3677 } else {
3678 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3679 sll->sll_halen = 0;
3680 }
3681 rcu_read_unlock();
3682
3683 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3684}
3685
3686static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3687 int what)
3688{
3689 switch (i->type) {
3690 case PACKET_MR_MULTICAST:
3691 if (i->alen != dev->addr_len)
3692 return -EINVAL;
3693 if (what > 0)
3694 return dev_mc_add(dev, i->addr);
3695 else
3696 return dev_mc_del(dev, i->addr);
3697 break;
3698 case PACKET_MR_PROMISC:
3699 return dev_set_promiscuity(dev, what);
3700 case PACKET_MR_ALLMULTI:
3701 return dev_set_allmulti(dev, what);
3702 case PACKET_MR_UNICAST:
3703 if (i->alen != dev->addr_len)
3704 return -EINVAL;
3705 if (what > 0)
3706 return dev_uc_add(dev, i->addr);
3707 else
3708 return dev_uc_del(dev, i->addr);
3709 break;
3710 default:
3711 break;
3712 }
3713 return 0;
3714}
3715
3716static void packet_dev_mclist_delete(struct net_device *dev,
3717 struct packet_mclist **mlp)
3718{
3719 struct packet_mclist *ml;
3720
3721 while ((ml = *mlp) != NULL) {
3722 if (ml->ifindex == dev->ifindex) {
3723 packet_dev_mc(dev, ml, -1);
3724 *mlp = ml->next;
3725 kfree(ml);
3726 } else
3727 mlp = &ml->next;
3728 }
3729}
3730
3731static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3732{
3733 struct packet_sock *po = pkt_sk(sk);
3734 struct packet_mclist *ml, *i;
3735 struct net_device *dev;
3736 int err;
3737
3738 rtnl_lock();
3739
3740 err = -ENODEV;
3741 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3742 if (!dev)
3743 goto done;
3744
3745 err = -EINVAL;
3746 if (mreq->mr_alen > dev->addr_len)
3747 goto done;
3748
3749 err = -ENOBUFS;
3750 i = kmalloc(sizeof(*i), GFP_KERNEL);
3751 if (i == NULL)
3752 goto done;
3753
3754 err = 0;
3755 for (ml = po->mclist; ml; ml = ml->next) {
3756 if (ml->ifindex == mreq->mr_ifindex &&
3757 ml->type == mreq->mr_type &&
3758 ml->alen == mreq->mr_alen &&
3759 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3760 ml->count++;
3761 /* Free the new element ... */
3762 kfree(i);
3763 goto done;
3764 }
3765 }
3766
3767 i->type = mreq->mr_type;
3768 i->ifindex = mreq->mr_ifindex;
3769 i->alen = mreq->mr_alen;
3770 memcpy(i->addr, mreq->mr_address, i->alen);
3771 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3772 i->count = 1;
3773 i->next = po->mclist;
3774 po->mclist = i;
3775 err = packet_dev_mc(dev, i, 1);
3776 if (err) {
3777 po->mclist = i->next;
3778 kfree(i);
3779 }
3780
3781done:
3782 rtnl_unlock();
3783 return err;
3784}
3785
3786static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3787{
3788 struct packet_mclist *ml, **mlp;
3789
3790 rtnl_lock();
3791
3792 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3793 if (ml->ifindex == mreq->mr_ifindex &&
3794 ml->type == mreq->mr_type &&
3795 ml->alen == mreq->mr_alen &&
3796 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3797 if (--ml->count == 0) {
3798 struct net_device *dev;
3799 *mlp = ml->next;
3800 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3801 if (dev)
3802 packet_dev_mc(dev, ml, -1);
3803 kfree(ml);
3804 }
3805 break;
3806 }
3807 }
3808 rtnl_unlock();
3809 return 0;
3810}
3811
3812static void packet_flush_mclist(struct sock *sk)
3813{
3814 struct packet_sock *po = pkt_sk(sk);
3815 struct packet_mclist *ml;
3816
3817 if (!po->mclist)
3818 return;
3819
3820 rtnl_lock();
3821 while ((ml = po->mclist) != NULL) {
3822 struct net_device *dev;
3823
3824 po->mclist = ml->next;
3825 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3826 if (dev != NULL)
3827 packet_dev_mc(dev, ml, -1);
3828 kfree(ml);
3829 }
3830 rtnl_unlock();
3831}
3832
3833static int
3834packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3835 unsigned int optlen)
3836{
3837 struct sock *sk = sock->sk;
3838 struct packet_sock *po = pkt_sk(sk);
3839 int ret;
3840
3841 if (level != SOL_PACKET)
3842 return -ENOPROTOOPT;
3843
3844 switch (optname) {
3845 case PACKET_ADD_MEMBERSHIP:
3846 case PACKET_DROP_MEMBERSHIP:
3847 {
3848 struct packet_mreq_max mreq;
3849 int len = optlen;
3850 memset(&mreq, 0, sizeof(mreq));
3851 if (len < sizeof(struct packet_mreq))
3852 return -EINVAL;
3853 if (len > sizeof(mreq))
3854 len = sizeof(mreq);
3855 if (copy_from_sockptr(&mreq, optval, len))
3856 return -EFAULT;
3857 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3858 return -EINVAL;
3859 if (optname == PACKET_ADD_MEMBERSHIP)
3860 ret = packet_mc_add(sk, &mreq);
3861 else
3862 ret = packet_mc_drop(sk, &mreq);
3863 return ret;
3864 }
3865
3866 case PACKET_RX_RING:
3867 case PACKET_TX_RING:
3868 {
3869 union tpacket_req_u req_u;
3870
3871 ret = -EINVAL;
3872 lock_sock(sk);
3873 switch (po->tp_version) {
3874 case TPACKET_V1:
3875 case TPACKET_V2:
3876 if (optlen < sizeof(req_u.req))
3877 break;
3878 ret = copy_from_sockptr(&req_u.req, optval,
3879 sizeof(req_u.req)) ?
3880 -EINVAL : 0;
3881 break;
3882 case TPACKET_V3:
3883 default:
3884 if (optlen < sizeof(req_u.req3))
3885 break;
3886 ret = copy_from_sockptr(&req_u.req3, optval,
3887 sizeof(req_u.req3)) ?
3888 -EINVAL : 0;
3889 break;
3890 }
3891 if (!ret)
3892 ret = packet_set_ring(sk, &req_u, 0,
3893 optname == PACKET_TX_RING);
3894 release_sock(sk);
3895 return ret;
3896 }
3897 case PACKET_COPY_THRESH:
3898 {
3899 int val;
3900
3901 if (optlen != sizeof(val))
3902 return -EINVAL;
3903 if (copy_from_sockptr(&val, optval, sizeof(val)))
3904 return -EFAULT;
3905
3906 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val);
3907 return 0;
3908 }
3909 case PACKET_VERSION:
3910 {
3911 int val;
3912
3913 if (optlen != sizeof(val))
3914 return -EINVAL;
3915 if (copy_from_sockptr(&val, optval, sizeof(val)))
3916 return -EFAULT;
3917 switch (val) {
3918 case TPACKET_V1:
3919 case TPACKET_V2:
3920 case TPACKET_V3:
3921 break;
3922 default:
3923 return -EINVAL;
3924 }
3925 lock_sock(sk);
3926 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3927 ret = -EBUSY;
3928 } else {
3929 po->tp_version = val;
3930 ret = 0;
3931 }
3932 release_sock(sk);
3933 return ret;
3934 }
3935 case PACKET_RESERVE:
3936 {
3937 unsigned int val;
3938
3939 if (optlen != sizeof(val))
3940 return -EINVAL;
3941 if (copy_from_sockptr(&val, optval, sizeof(val)))
3942 return -EFAULT;
3943 if (val > INT_MAX)
3944 return -EINVAL;
3945 lock_sock(sk);
3946 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3947 ret = -EBUSY;
3948 } else {
3949 po->tp_reserve = val;
3950 ret = 0;
3951 }
3952 release_sock(sk);
3953 return ret;
3954 }
3955 case PACKET_LOSS:
3956 {
3957 unsigned int val;
3958
3959 if (optlen != sizeof(val))
3960 return -EINVAL;
3961 if (copy_from_sockptr(&val, optval, sizeof(val)))
3962 return -EFAULT;
3963
3964 lock_sock(sk);
3965 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3966 ret = -EBUSY;
3967 } else {
3968 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val);
3969 ret = 0;
3970 }
3971 release_sock(sk);
3972 return ret;
3973 }
3974 case PACKET_AUXDATA:
3975 {
3976 int val;
3977
3978 if (optlen < sizeof(val))
3979 return -EINVAL;
3980 if (copy_from_sockptr(&val, optval, sizeof(val)))
3981 return -EFAULT;
3982
3983 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val);
3984 return 0;
3985 }
3986 case PACKET_ORIGDEV:
3987 {
3988 int val;
3989
3990 if (optlen < sizeof(val))
3991 return -EINVAL;
3992 if (copy_from_sockptr(&val, optval, sizeof(val)))
3993 return -EFAULT;
3994
3995 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val);
3996 return 0;
3997 }
3998 case PACKET_VNET_HDR:
3999 case PACKET_VNET_HDR_SZ:
4000 {
4001 int val, hdr_len;
4002
4003 if (sock->type != SOCK_RAW)
4004 return -EINVAL;
4005 if (optlen < sizeof(val))
4006 return -EINVAL;
4007 if (copy_from_sockptr(&val, optval, sizeof(val)))
4008 return -EFAULT;
4009
4010 if (optname == PACKET_VNET_HDR_SZ) {
4011 if (val && val != sizeof(struct virtio_net_hdr) &&
4012 val != sizeof(struct virtio_net_hdr_mrg_rxbuf))
4013 return -EINVAL;
4014 hdr_len = val;
4015 } else {
4016 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0;
4017 }
4018 lock_sock(sk);
4019 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
4020 ret = -EBUSY;
4021 } else {
4022 WRITE_ONCE(po->vnet_hdr_sz, hdr_len);
4023 ret = 0;
4024 }
4025 release_sock(sk);
4026 return ret;
4027 }
4028 case PACKET_TIMESTAMP:
4029 {
4030 int val;
4031
4032 if (optlen != sizeof(val))
4033 return -EINVAL;
4034 if (copy_from_sockptr(&val, optval, sizeof(val)))
4035 return -EFAULT;
4036
4037 WRITE_ONCE(po->tp_tstamp, val);
4038 return 0;
4039 }
4040 case PACKET_FANOUT:
4041 {
4042 struct fanout_args args = { 0 };
4043
4044 if (optlen != sizeof(int) && optlen != sizeof(args))
4045 return -EINVAL;
4046 if (copy_from_sockptr(&args, optval, optlen))
4047 return -EFAULT;
4048
4049 return fanout_add(sk, &args);
4050 }
4051 case PACKET_FANOUT_DATA:
4052 {
4053 /* Paired with the WRITE_ONCE() in fanout_add() */
4054 if (!READ_ONCE(po->fanout))
4055 return -EINVAL;
4056
4057 return fanout_set_data(po, optval, optlen);
4058 }
4059 case PACKET_IGNORE_OUTGOING:
4060 {
4061 int val;
4062
4063 if (optlen != sizeof(val))
4064 return -EINVAL;
4065 if (copy_from_sockptr(&val, optval, sizeof(val)))
4066 return -EFAULT;
4067 if (val < 0 || val > 1)
4068 return -EINVAL;
4069
4070 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val);
4071 return 0;
4072 }
4073 case PACKET_TX_HAS_OFF:
4074 {
4075 unsigned int val;
4076
4077 if (optlen != sizeof(val))
4078 return -EINVAL;
4079 if (copy_from_sockptr(&val, optval, sizeof(val)))
4080 return -EFAULT;
4081
4082 lock_sock(sk);
4083 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec)
4084 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val);
4085
4086 release_sock(sk);
4087 return 0;
4088 }
4089 case PACKET_QDISC_BYPASS:
4090 {
4091 int val;
4092
4093 if (optlen != sizeof(val))
4094 return -EINVAL;
4095 if (copy_from_sockptr(&val, optval, sizeof(val)))
4096 return -EFAULT;
4097
4098 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val);
4099 return 0;
4100 }
4101 default:
4102 return -ENOPROTOOPT;
4103 }
4104}
4105
4106static int packet_getsockopt(struct socket *sock, int level, int optname,
4107 char __user *optval, int __user *optlen)
4108{
4109 int len;
4110 int val, lv = sizeof(val);
4111 struct sock *sk = sock->sk;
4112 struct packet_sock *po = pkt_sk(sk);
4113 void *data = &val;
4114 union tpacket_stats_u st;
4115 struct tpacket_rollover_stats rstats;
4116 int drops;
4117
4118 if (level != SOL_PACKET)
4119 return -ENOPROTOOPT;
4120
4121 if (get_user(len, optlen))
4122 return -EFAULT;
4123
4124 if (len < 0)
4125 return -EINVAL;
4126
4127 switch (optname) {
4128 case PACKET_STATISTICS:
4129 spin_lock_bh(&sk->sk_receive_queue.lock);
4130 memcpy(&st, &po->stats, sizeof(st));
4131 memset(&po->stats, 0, sizeof(po->stats));
4132 spin_unlock_bh(&sk->sk_receive_queue.lock);
4133 drops = atomic_xchg(&po->tp_drops, 0);
4134
4135 if (po->tp_version == TPACKET_V3) {
4136 lv = sizeof(struct tpacket_stats_v3);
4137 st.stats3.tp_drops = drops;
4138 st.stats3.tp_packets += drops;
4139 data = &st.stats3;
4140 } else {
4141 lv = sizeof(struct tpacket_stats);
4142 st.stats1.tp_drops = drops;
4143 st.stats1.tp_packets += drops;
4144 data = &st.stats1;
4145 }
4146
4147 break;
4148 case PACKET_AUXDATA:
4149 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA);
4150 break;
4151 case PACKET_ORIGDEV:
4152 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV);
4153 break;
4154 case PACKET_VNET_HDR:
4155 val = !!READ_ONCE(po->vnet_hdr_sz);
4156 break;
4157 case PACKET_VNET_HDR_SZ:
4158 val = READ_ONCE(po->vnet_hdr_sz);
4159 break;
4160 case PACKET_COPY_THRESH:
4161 val = READ_ONCE(pkt_sk(sk)->copy_thresh);
4162 break;
4163 case PACKET_VERSION:
4164 val = po->tp_version;
4165 break;
4166 case PACKET_HDRLEN:
4167 if (len > sizeof(int))
4168 len = sizeof(int);
4169 if (len < sizeof(int))
4170 return -EINVAL;
4171 if (copy_from_user(&val, optval, len))
4172 return -EFAULT;
4173 switch (val) {
4174 case TPACKET_V1:
4175 val = sizeof(struct tpacket_hdr);
4176 break;
4177 case TPACKET_V2:
4178 val = sizeof(struct tpacket2_hdr);
4179 break;
4180 case TPACKET_V3:
4181 val = sizeof(struct tpacket3_hdr);
4182 break;
4183 default:
4184 return -EINVAL;
4185 }
4186 break;
4187 case PACKET_RESERVE:
4188 val = po->tp_reserve;
4189 break;
4190 case PACKET_LOSS:
4191 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS);
4192 break;
4193 case PACKET_TIMESTAMP:
4194 val = READ_ONCE(po->tp_tstamp);
4195 break;
4196 case PACKET_FANOUT:
4197 val = (po->fanout ?
4198 ((u32)po->fanout->id |
4199 ((u32)po->fanout->type << 16) |
4200 ((u32)po->fanout->flags << 24)) :
4201 0);
4202 break;
4203 case PACKET_IGNORE_OUTGOING:
4204 val = READ_ONCE(po->prot_hook.ignore_outgoing);
4205 break;
4206 case PACKET_ROLLOVER_STATS:
4207 if (!po->rollover)
4208 return -EINVAL;
4209 rstats.tp_all = atomic_long_read(&po->rollover->num);
4210 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4211 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4212 data = &rstats;
4213 lv = sizeof(rstats);
4214 break;
4215 case PACKET_TX_HAS_OFF:
4216 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF);
4217 break;
4218 case PACKET_QDISC_BYPASS:
4219 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS);
4220 break;
4221 default:
4222 return -ENOPROTOOPT;
4223 }
4224
4225 if (len > lv)
4226 len = lv;
4227 if (put_user(len, optlen))
4228 return -EFAULT;
4229 if (copy_to_user(optval, data, len))
4230 return -EFAULT;
4231 return 0;
4232}
4233
4234static int packet_notifier(struct notifier_block *this,
4235 unsigned long msg, void *ptr)
4236{
4237 struct sock *sk;
4238 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4239 struct net *net = dev_net(dev);
4240
4241 rcu_read_lock();
4242 sk_for_each_rcu(sk, &net->packet.sklist) {
4243 struct packet_sock *po = pkt_sk(sk);
4244
4245 switch (msg) {
4246 case NETDEV_UNREGISTER:
4247 if (po->mclist)
4248 packet_dev_mclist_delete(dev, &po->mclist);
4249 fallthrough;
4250
4251 case NETDEV_DOWN:
4252 if (dev->ifindex == po->ifindex) {
4253 spin_lock(&po->bind_lock);
4254 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
4255 __unregister_prot_hook(sk, false);
4256 sk->sk_err = ENETDOWN;
4257 if (!sock_flag(sk, SOCK_DEAD))
4258 sk_error_report(sk);
4259 }
4260 if (msg == NETDEV_UNREGISTER) {
4261 packet_cached_dev_reset(po);
4262 WRITE_ONCE(po->ifindex, -1);
4263 netdev_put(po->prot_hook.dev,
4264 &po->prot_hook.dev_tracker);
4265 po->prot_hook.dev = NULL;
4266 }
4267 spin_unlock(&po->bind_lock);
4268 }
4269 break;
4270 case NETDEV_UP:
4271 if (dev->ifindex == po->ifindex) {
4272 spin_lock(&po->bind_lock);
4273 if (po->num)
4274 register_prot_hook(sk);
4275 spin_unlock(&po->bind_lock);
4276 }
4277 break;
4278 }
4279 }
4280 rcu_read_unlock();
4281 return NOTIFY_DONE;
4282}
4283
4284
4285static int packet_ioctl(struct socket *sock, unsigned int cmd,
4286 unsigned long arg)
4287{
4288 struct sock *sk = sock->sk;
4289
4290 switch (cmd) {
4291 case SIOCOUTQ:
4292 {
4293 int amount = sk_wmem_alloc_get(sk);
4294
4295 return put_user(amount, (int __user *)arg);
4296 }
4297 case SIOCINQ:
4298 {
4299 struct sk_buff *skb;
4300 int amount = 0;
4301
4302 spin_lock_bh(&sk->sk_receive_queue.lock);
4303 skb = skb_peek(&sk->sk_receive_queue);
4304 if (skb)
4305 amount = skb->len;
4306 spin_unlock_bh(&sk->sk_receive_queue.lock);
4307 return put_user(amount, (int __user *)arg);
4308 }
4309#ifdef CONFIG_INET
4310 case SIOCADDRT:
4311 case SIOCDELRT:
4312 case SIOCDARP:
4313 case SIOCGARP:
4314 case SIOCSARP:
4315 case SIOCGIFADDR:
4316 case SIOCSIFADDR:
4317 case SIOCGIFBRDADDR:
4318 case SIOCSIFBRDADDR:
4319 case SIOCGIFNETMASK:
4320 case SIOCSIFNETMASK:
4321 case SIOCGIFDSTADDR:
4322 case SIOCSIFDSTADDR:
4323 case SIOCSIFFLAGS:
4324 return inet_dgram_ops.ioctl(sock, cmd, arg);
4325#endif
4326
4327 default:
4328 return -ENOIOCTLCMD;
4329 }
4330 return 0;
4331}
4332
4333static __poll_t packet_poll(struct file *file, struct socket *sock,
4334 poll_table *wait)
4335{
4336 struct sock *sk = sock->sk;
4337 struct packet_sock *po = pkt_sk(sk);
4338 __poll_t mask = datagram_poll(file, sock, wait);
4339
4340 spin_lock_bh(&sk->sk_receive_queue.lock);
4341 if (po->rx_ring.pg_vec) {
4342 if (!packet_previous_rx_frame(po, &po->rx_ring,
4343 TP_STATUS_KERNEL))
4344 mask |= EPOLLIN | EPOLLRDNORM;
4345 }
4346 packet_rcv_try_clear_pressure(po);
4347 spin_unlock_bh(&sk->sk_receive_queue.lock);
4348 spin_lock_bh(&sk->sk_write_queue.lock);
4349 if (po->tx_ring.pg_vec) {
4350 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4351 mask |= EPOLLOUT | EPOLLWRNORM;
4352 }
4353 spin_unlock_bh(&sk->sk_write_queue.lock);
4354 return mask;
4355}
4356
4357
4358/* Dirty? Well, I still did not learn better way to account
4359 * for user mmaps.
4360 */
4361
4362static void packet_mm_open(struct vm_area_struct *vma)
4363{
4364 struct file *file = vma->vm_file;
4365 struct socket *sock = file->private_data;
4366 struct sock *sk = sock->sk;
4367
4368 if (sk)
4369 atomic_long_inc(&pkt_sk(sk)->mapped);
4370}
4371
4372static void packet_mm_close(struct vm_area_struct *vma)
4373{
4374 struct file *file = vma->vm_file;
4375 struct socket *sock = file->private_data;
4376 struct sock *sk = sock->sk;
4377
4378 if (sk)
4379 atomic_long_dec(&pkt_sk(sk)->mapped);
4380}
4381
4382static const struct vm_operations_struct packet_mmap_ops = {
4383 .open = packet_mm_open,
4384 .close = packet_mm_close,
4385};
4386
4387static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4388 unsigned int len)
4389{
4390 int i;
4391
4392 for (i = 0; i < len; i++) {
4393 if (likely(pg_vec[i].buffer)) {
4394 if (is_vmalloc_addr(pg_vec[i].buffer))
4395 vfree(pg_vec[i].buffer);
4396 else
4397 free_pages((unsigned long)pg_vec[i].buffer,
4398 order);
4399 pg_vec[i].buffer = NULL;
4400 }
4401 }
4402 kfree(pg_vec);
4403}
4404
4405static char *alloc_one_pg_vec_page(unsigned long order)
4406{
4407 char *buffer;
4408 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4409 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4410
4411 buffer = (char *) __get_free_pages(gfp_flags, order);
4412 if (buffer)
4413 return buffer;
4414
4415 /* __get_free_pages failed, fall back to vmalloc */
4416 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4417 if (buffer)
4418 return buffer;
4419
4420 /* vmalloc failed, lets dig into swap here */
4421 gfp_flags &= ~__GFP_NORETRY;
4422 buffer = (char *) __get_free_pages(gfp_flags, order);
4423 if (buffer)
4424 return buffer;
4425
4426 /* complete and utter failure */
4427 return NULL;
4428}
4429
4430static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4431{
4432 unsigned int block_nr = req->tp_block_nr;
4433 struct pgv *pg_vec;
4434 int i;
4435
4436 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4437 if (unlikely(!pg_vec))
4438 goto out;
4439
4440 for (i = 0; i < block_nr; i++) {
4441 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4442 if (unlikely(!pg_vec[i].buffer))
4443 goto out_free_pgvec;
4444 }
4445
4446out:
4447 return pg_vec;
4448
4449out_free_pgvec:
4450 free_pg_vec(pg_vec, order, block_nr);
4451 pg_vec = NULL;
4452 goto out;
4453}
4454
4455static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4456 int closing, int tx_ring)
4457{
4458 struct pgv *pg_vec = NULL;
4459 struct packet_sock *po = pkt_sk(sk);
4460 unsigned long *rx_owner_map = NULL;
4461 int was_running, order = 0;
4462 struct packet_ring_buffer *rb;
4463 struct sk_buff_head *rb_queue;
4464 __be16 num;
4465 int err;
4466 /* Added to avoid minimal code churn */
4467 struct tpacket_req *req = &req_u->req;
4468
4469 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4470 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4471
4472 err = -EBUSY;
4473 if (!closing) {
4474 if (atomic_long_read(&po->mapped))
4475 goto out;
4476 if (packet_read_pending(rb))
4477 goto out;
4478 }
4479
4480 if (req->tp_block_nr) {
4481 unsigned int min_frame_size;
4482
4483 /* Sanity tests and some calculations */
4484 err = -EBUSY;
4485 if (unlikely(rb->pg_vec))
4486 goto out;
4487
4488 switch (po->tp_version) {
4489 case TPACKET_V1:
4490 po->tp_hdrlen = TPACKET_HDRLEN;
4491 break;
4492 case TPACKET_V2:
4493 po->tp_hdrlen = TPACKET2_HDRLEN;
4494 break;
4495 case TPACKET_V3:
4496 po->tp_hdrlen = TPACKET3_HDRLEN;
4497 break;
4498 }
4499
4500 err = -EINVAL;
4501 if (unlikely((int)req->tp_block_size <= 0))
4502 goto out;
4503 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4504 goto out;
4505 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4506 if (po->tp_version >= TPACKET_V3 &&
4507 req->tp_block_size <
4508 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4509 goto out;
4510 if (unlikely(req->tp_frame_size < min_frame_size))
4511 goto out;
4512 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4513 goto out;
4514
4515 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4516 if (unlikely(rb->frames_per_block == 0))
4517 goto out;
4518 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4519 goto out;
4520 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4521 req->tp_frame_nr))
4522 goto out;
4523
4524 err = -ENOMEM;
4525 order = get_order(req->tp_block_size);
4526 pg_vec = alloc_pg_vec(req, order);
4527 if (unlikely(!pg_vec))
4528 goto out;
4529 switch (po->tp_version) {
4530 case TPACKET_V3:
4531 /* Block transmit is not supported yet */
4532 if (!tx_ring) {
4533 init_prb_bdqc(po, rb, pg_vec, req_u);
4534 } else {
4535 struct tpacket_req3 *req3 = &req_u->req3;
4536
4537 if (req3->tp_retire_blk_tov ||
4538 req3->tp_sizeof_priv ||
4539 req3->tp_feature_req_word) {
4540 err = -EINVAL;
4541 goto out_free_pg_vec;
4542 }
4543 }
4544 break;
4545 default:
4546 if (!tx_ring) {
4547 rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4548 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4549 if (!rx_owner_map)
4550 goto out_free_pg_vec;
4551 }
4552 break;
4553 }
4554 }
4555 /* Done */
4556 else {
4557 err = -EINVAL;
4558 if (unlikely(req->tp_frame_nr))
4559 goto out;
4560 }
4561
4562
4563 /* Detach socket from network */
4564 spin_lock(&po->bind_lock);
4565 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING);
4566 num = po->num;
4567 if (was_running) {
4568 WRITE_ONCE(po->num, 0);
4569 __unregister_prot_hook(sk, false);
4570 }
4571 spin_unlock(&po->bind_lock);
4572
4573 synchronize_net();
4574
4575 err = -EBUSY;
4576 mutex_lock(&po->pg_vec_lock);
4577 if (closing || atomic_long_read(&po->mapped) == 0) {
4578 err = 0;
4579 spin_lock_bh(&rb_queue->lock);
4580 swap(rb->pg_vec, pg_vec);
4581 if (po->tp_version <= TPACKET_V2)
4582 swap(rb->rx_owner_map, rx_owner_map);
4583 rb->frame_max = (req->tp_frame_nr - 1);
4584 rb->head = 0;
4585 rb->frame_size = req->tp_frame_size;
4586 spin_unlock_bh(&rb_queue->lock);
4587
4588 swap(rb->pg_vec_order, order);
4589 swap(rb->pg_vec_len, req->tp_block_nr);
4590
4591 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4592 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4593 tpacket_rcv : packet_rcv;
4594 skb_queue_purge(rb_queue);
4595 if (atomic_long_read(&po->mapped))
4596 pr_err("packet_mmap: vma is busy: %ld\n",
4597 atomic_long_read(&po->mapped));
4598 }
4599 mutex_unlock(&po->pg_vec_lock);
4600
4601 spin_lock(&po->bind_lock);
4602 if (was_running) {
4603 WRITE_ONCE(po->num, num);
4604 register_prot_hook(sk);
4605 }
4606 spin_unlock(&po->bind_lock);
4607 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4608 /* Because we don't support block-based V3 on tx-ring */
4609 if (!tx_ring)
4610 prb_shutdown_retire_blk_timer(po, rb_queue);
4611 }
4612
4613out_free_pg_vec:
4614 if (pg_vec) {
4615 bitmap_free(rx_owner_map);
4616 free_pg_vec(pg_vec, order, req->tp_block_nr);
4617 }
4618out:
4619 return err;
4620}
4621
4622static int packet_mmap(struct file *file, struct socket *sock,
4623 struct vm_area_struct *vma)
4624{
4625 struct sock *sk = sock->sk;
4626 struct packet_sock *po = pkt_sk(sk);
4627 unsigned long size, expected_size;
4628 struct packet_ring_buffer *rb;
4629 unsigned long start;
4630 int err = -EINVAL;
4631 int i;
4632
4633 if (vma->vm_pgoff)
4634 return -EINVAL;
4635
4636 mutex_lock(&po->pg_vec_lock);
4637
4638 expected_size = 0;
4639 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4640 if (rb->pg_vec) {
4641 expected_size += rb->pg_vec_len
4642 * rb->pg_vec_pages
4643 * PAGE_SIZE;
4644 }
4645 }
4646
4647 if (expected_size == 0)
4648 goto out;
4649
4650 size = vma->vm_end - vma->vm_start;
4651 if (size != expected_size)
4652 goto out;
4653
4654 start = vma->vm_start;
4655 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4656 if (rb->pg_vec == NULL)
4657 continue;
4658
4659 for (i = 0; i < rb->pg_vec_len; i++) {
4660 struct page *page;
4661 void *kaddr = rb->pg_vec[i].buffer;
4662 int pg_num;
4663
4664 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4665 page = pgv_to_page(kaddr);
4666 err = vm_insert_page(vma, start, page);
4667 if (unlikely(err))
4668 goto out;
4669 start += PAGE_SIZE;
4670 kaddr += PAGE_SIZE;
4671 }
4672 }
4673 }
4674
4675 atomic_long_inc(&po->mapped);
4676 vma->vm_ops = &packet_mmap_ops;
4677 err = 0;
4678
4679out:
4680 mutex_unlock(&po->pg_vec_lock);
4681 return err;
4682}
4683
4684static const struct proto_ops packet_ops_spkt = {
4685 .family = PF_PACKET,
4686 .owner = THIS_MODULE,
4687 .release = packet_release,
4688 .bind = packet_bind_spkt,
4689 .connect = sock_no_connect,
4690 .socketpair = sock_no_socketpair,
4691 .accept = sock_no_accept,
4692 .getname = packet_getname_spkt,
4693 .poll = datagram_poll,
4694 .ioctl = packet_ioctl,
4695 .gettstamp = sock_gettstamp,
4696 .listen = sock_no_listen,
4697 .shutdown = sock_no_shutdown,
4698 .sendmsg = packet_sendmsg_spkt,
4699 .recvmsg = packet_recvmsg,
4700 .mmap = sock_no_mmap,
4701};
4702
4703static const struct proto_ops packet_ops = {
4704 .family = PF_PACKET,
4705 .owner = THIS_MODULE,
4706 .release = packet_release,
4707 .bind = packet_bind,
4708 .connect = sock_no_connect,
4709 .socketpair = sock_no_socketpair,
4710 .accept = sock_no_accept,
4711 .getname = packet_getname,
4712 .poll = packet_poll,
4713 .ioctl = packet_ioctl,
4714 .gettstamp = sock_gettstamp,
4715 .listen = sock_no_listen,
4716 .shutdown = sock_no_shutdown,
4717 .setsockopt = packet_setsockopt,
4718 .getsockopt = packet_getsockopt,
4719 .sendmsg = packet_sendmsg,
4720 .recvmsg = packet_recvmsg,
4721 .mmap = packet_mmap,
4722};
4723
4724static const struct net_proto_family packet_family_ops = {
4725 .family = PF_PACKET,
4726 .create = packet_create,
4727 .owner = THIS_MODULE,
4728};
4729
4730static struct notifier_block packet_netdev_notifier = {
4731 .notifier_call = packet_notifier,
4732};
4733
4734#ifdef CONFIG_PROC_FS
4735
4736static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4737 __acquires(RCU)
4738{
4739 struct net *net = seq_file_net(seq);
4740
4741 rcu_read_lock();
4742 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4743}
4744
4745static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4746{
4747 struct net *net = seq_file_net(seq);
4748 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4749}
4750
4751static void packet_seq_stop(struct seq_file *seq, void *v)
4752 __releases(RCU)
4753{
4754 rcu_read_unlock();
4755}
4756
4757static int packet_seq_show(struct seq_file *seq, void *v)
4758{
4759 if (v == SEQ_START_TOKEN)
4760 seq_printf(seq,
4761 "%*sRefCnt Type Proto Iface R Rmem User Inode\n",
4762 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk");
4763 else {
4764 struct sock *s = sk_entry(v);
4765 const struct packet_sock *po = pkt_sk(s);
4766
4767 seq_printf(seq,
4768 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4769 s,
4770 refcount_read(&s->sk_refcnt),
4771 s->sk_type,
4772 ntohs(READ_ONCE(po->num)),
4773 READ_ONCE(po->ifindex),
4774 packet_sock_flag(po, PACKET_SOCK_RUNNING),
4775 atomic_read(&s->sk_rmem_alloc),
4776 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4777 sock_i_ino(s));
4778 }
4779
4780 return 0;
4781}
4782
4783static const struct seq_operations packet_seq_ops = {
4784 .start = packet_seq_start,
4785 .next = packet_seq_next,
4786 .stop = packet_seq_stop,
4787 .show = packet_seq_show,
4788};
4789#endif
4790
4791static int __net_init packet_net_init(struct net *net)
4792{
4793 mutex_init(&net->packet.sklist_lock);
4794 INIT_HLIST_HEAD(&net->packet.sklist);
4795
4796#ifdef CONFIG_PROC_FS
4797 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4798 sizeof(struct seq_net_private)))
4799 return -ENOMEM;
4800#endif /* CONFIG_PROC_FS */
4801
4802 return 0;
4803}
4804
4805static void __net_exit packet_net_exit(struct net *net)
4806{
4807 remove_proc_entry("packet", net->proc_net);
4808 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4809}
4810
4811static struct pernet_operations packet_net_ops = {
4812 .init = packet_net_init,
4813 .exit = packet_net_exit,
4814};
4815
4816
4817static void __exit packet_exit(void)
4818{
4819 sock_unregister(PF_PACKET);
4820 proto_unregister(&packet_proto);
4821 unregister_netdevice_notifier(&packet_netdev_notifier);
4822 unregister_pernet_subsys(&packet_net_ops);
4823}
4824
4825static int __init packet_init(void)
4826{
4827 int rc;
4828
4829 rc = register_pernet_subsys(&packet_net_ops);
4830 if (rc)
4831 goto out;
4832 rc = register_netdevice_notifier(&packet_netdev_notifier);
4833 if (rc)
4834 goto out_pernet;
4835 rc = proto_register(&packet_proto, 0);
4836 if (rc)
4837 goto out_notifier;
4838 rc = sock_register(&packet_family_ops);
4839 if (rc)
4840 goto out_proto;
4841
4842 return 0;
4843
4844out_proto:
4845 proto_unregister(&packet_proto);
4846out_notifier:
4847 unregister_netdevice_notifier(&packet_netdev_notifier);
4848out_pernet:
4849 unregister_pernet_subsys(&packet_net_ops);
4850out:
4851 return rc;
4852}
4853
4854module_init(packet_init);
4855module_exit(packet_exit);
4856MODULE_DESCRIPTION("Packet socket support (AF_PACKET)");
4857MODULE_LICENSE("GPL");
4858MODULE_ALIAS_NETPROTO(PF_PACKET);