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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/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
44 * layer.
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
46 *
47 *
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
52 *
53 */
54
55#include <linux/types.h>
56#include <linux/mm.h>
57#include <linux/capability.h>
58#include <linux/fcntl.h>
59#include <linux/socket.h>
60#include <linux/in.h>
61#include <linux/inet.h>
62#include <linux/netdevice.h>
63#include <linux/if_packet.h>
64#include <linux/wireless.h>
65#include <linux/kernel.h>
66#include <linux/kmod.h>
67#include <linux/slab.h>
68#include <linux/vmalloc.h>
69#include <net/net_namespace.h>
70#include <net/ip.h>
71#include <net/protocol.h>
72#include <linux/skbuff.h>
73#include <net/sock.h>
74#include <linux/errno.h>
75#include <linux/timer.h>
76#include <linux/uaccess.h>
77#include <asm/ioctls.h>
78#include <asm/page.h>
79#include <asm/cacheflush.h>
80#include <asm/io.h>
81#include <linux/proc_fs.h>
82#include <linux/seq_file.h>
83#include <linux/poll.h>
84#include <linux/module.h>
85#include <linux/init.h>
86#include <linux/mutex.h>
87#include <linux/if_vlan.h>
88#include <linux/virtio_net.h>
89#include <linux/errqueue.h>
90#include <linux/net_tstamp.h>
91#include <linux/percpu.h>
92#ifdef CONFIG_INET
93#include <net/inet_common.h>
94#endif
95#include <linux/bpf.h>
96#include <net/compat.h>
97
98#include "internal.h"
99
100/*
101 Assumptions:
102 - if device has no dev->hard_header routine, it adds and removes ll header
103 inside itself. In this case ll header is invisible outside of device,
104 but higher levels still should reserve dev->hard_header_len.
105 Some devices are enough clever to reallocate skb, when header
106 will not fit to reserved space (tunnel), another ones are silly
107 (PPP).
108 - packet socket receives packets with pulled ll header,
109 so that SOCK_RAW should push it back.
110
111On receive:
112-----------
113
114Incoming, dev->hard_header!=NULL
115 mac_header -> ll header
116 data -> data
117
118Outgoing, dev->hard_header!=NULL
119 mac_header -> ll header
120 data -> ll header
121
122Incoming, dev->hard_header==NULL
123 mac_header -> UNKNOWN position. It is very likely, that it points to ll
124 header. PPP makes it, that is wrong, because introduce
125 assymetry between rx and tx paths.
126 data -> data
127
128Outgoing, dev->hard_header==NULL
129 mac_header -> data. ll header is still not built!
130 data -> data
131
132Resume
133 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
134
135
136On transmit:
137------------
138
139dev->hard_header != NULL
140 mac_header -> ll header
141 data -> ll header
142
143dev->hard_header == NULL (ll header is added by device, we cannot control it)
144 mac_header -> data
145 data -> data
146
147 We should set nh.raw on output to correct posistion,
148 packet classifier depends on it.
149 */
150
151/* Private packet socket structures. */
152
153/* identical to struct packet_mreq except it has
154 * a longer address field.
155 */
156struct packet_mreq_max {
157 int mr_ifindex;
158 unsigned short mr_type;
159 unsigned short mr_alen;
160 unsigned char mr_address[MAX_ADDR_LEN];
161};
162
163union tpacket_uhdr {
164 struct tpacket_hdr *h1;
165 struct tpacket2_hdr *h2;
166 struct tpacket3_hdr *h3;
167 void *raw;
168};
169
170static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
171 int closing, int tx_ring);
172
173#define V3_ALIGNMENT (8)
174
175#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
176
177#define BLK_PLUS_PRIV(sz_of_priv) \
178 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
179
180#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
182#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
183#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
184#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
185#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186#define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
187
188struct packet_sock;
189static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
190 struct packet_type *pt, struct net_device *orig_dev);
191
192static void *packet_previous_frame(struct packet_sock *po,
193 struct packet_ring_buffer *rb,
194 int status);
195static void packet_increment_head(struct packet_ring_buffer *buff);
196static int prb_curr_blk_in_use(struct tpacket_block_desc *);
197static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
198 struct packet_sock *);
199static void prb_retire_current_block(struct tpacket_kbdq_core *,
200 struct packet_sock *, unsigned int status);
201static int prb_queue_frozen(struct tpacket_kbdq_core *);
202static void prb_open_block(struct tpacket_kbdq_core *,
203 struct tpacket_block_desc *);
204static void prb_retire_rx_blk_timer_expired(struct timer_list *);
205static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
206static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
207static void prb_clear_rxhash(struct tpacket_kbdq_core *,
208 struct tpacket3_hdr *);
209static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
210 struct tpacket3_hdr *);
211static void packet_flush_mclist(struct sock *sk);
212static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb);
213
214struct packet_skb_cb {
215 union {
216 struct sockaddr_pkt pkt;
217 union {
218 /* Trick: alias skb original length with
219 * ll.sll_family and ll.protocol in order
220 * to save room.
221 */
222 unsigned int origlen;
223 struct sockaddr_ll ll;
224 };
225 } sa;
226};
227
228#define vio_le() virtio_legacy_is_little_endian()
229
230#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
231
232#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
233#define GET_PBLOCK_DESC(x, bid) \
234 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
235#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
236 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
237#define GET_NEXT_PRB_BLK_NUM(x) \
238 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
239 ((x)->kactive_blk_num+1) : 0)
240
241static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
242static void __fanout_link(struct sock *sk, struct packet_sock *po);
243
244static int packet_direct_xmit(struct sk_buff *skb)
245{
246 struct net_device *dev = skb->dev;
247 struct sk_buff *orig_skb = skb;
248 struct netdev_queue *txq;
249 int ret = NETDEV_TX_BUSY;
250 bool again = false;
251
252 if (unlikely(!netif_running(dev) ||
253 !netif_carrier_ok(dev)))
254 goto drop;
255
256 skb = validate_xmit_skb_list(skb, dev, &again);
257 if (skb != orig_skb)
258 goto drop;
259
260 packet_pick_tx_queue(dev, skb);
261 txq = skb_get_tx_queue(dev, skb);
262
263 local_bh_disable();
264
265 HARD_TX_LOCK(dev, txq, smp_processor_id());
266 if (!netif_xmit_frozen_or_drv_stopped(txq))
267 ret = netdev_start_xmit(skb, dev, txq, false);
268 HARD_TX_UNLOCK(dev, txq);
269
270 local_bh_enable();
271
272 if (!dev_xmit_complete(ret))
273 kfree_skb(skb);
274
275 return ret;
276drop:
277 atomic_long_inc(&dev->tx_dropped);
278 kfree_skb_list(skb);
279 return NET_XMIT_DROP;
280}
281
282static struct net_device *packet_cached_dev_get(struct packet_sock *po)
283{
284 struct net_device *dev;
285
286 rcu_read_lock();
287 dev = rcu_dereference(po->cached_dev);
288 if (likely(dev))
289 dev_hold(dev);
290 rcu_read_unlock();
291
292 return dev;
293}
294
295static void packet_cached_dev_assign(struct packet_sock *po,
296 struct net_device *dev)
297{
298 rcu_assign_pointer(po->cached_dev, dev);
299}
300
301static void packet_cached_dev_reset(struct packet_sock *po)
302{
303 RCU_INIT_POINTER(po->cached_dev, NULL);
304}
305
306static bool packet_use_direct_xmit(const struct packet_sock *po)
307{
308 return po->xmit == packet_direct_xmit;
309}
310
311static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
312{
313 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
314}
315
316static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
317{
318 const struct net_device_ops *ops = dev->netdev_ops;
319 u16 queue_index;
320
321 if (ops->ndo_select_queue) {
322 queue_index = ops->ndo_select_queue(dev, skb, NULL,
323 __packet_pick_tx_queue);
324 queue_index = netdev_cap_txqueue(dev, queue_index);
325 } else {
326 queue_index = __packet_pick_tx_queue(dev, skb);
327 }
328
329 skb_set_queue_mapping(skb, 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 (!po->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 po->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 po->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 (po->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 h.raw = frame;
405 switch (po->tp_version) {
406 case TPACKET_V1:
407 h.h1->tp_status = status;
408 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
409 break;
410 case TPACKET_V2:
411 h.h2->tp_status = status;
412 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
413 break;
414 case TPACKET_V3:
415 h.h3->tp_status = status;
416 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
417 break;
418 default:
419 WARN(1, "TPACKET version not supported.\n");
420 BUG();
421 }
422
423 smp_wmb();
424}
425
426static int __packet_get_status(struct packet_sock *po, void *frame)
427{
428 union tpacket_uhdr h;
429
430 smp_rmb();
431
432 h.raw = frame;
433 switch (po->tp_version) {
434 case TPACKET_V1:
435 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
436 return h.h1->tp_status;
437 case TPACKET_V2:
438 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
439 return h.h2->tp_status;
440 case TPACKET_V3:
441 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
442 return h.h3->tp_status;
443 default:
444 WARN(1, "TPACKET version not supported.\n");
445 BUG();
446 return 0;
447 }
448}
449
450static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
451 unsigned int flags)
452{
453 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
454
455 if (shhwtstamps &&
456 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
457 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
458 return TP_STATUS_TS_RAW_HARDWARE;
459
460 if (ktime_to_timespec_cond(skb->tstamp, ts))
461 return TP_STATUS_TS_SOFTWARE;
462
463 return 0;
464}
465
466static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
467 struct sk_buff *skb)
468{
469 union tpacket_uhdr h;
470 struct timespec ts;
471 __u32 ts_status;
472
473 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
474 return 0;
475
476 h.raw = frame;
477 switch (po->tp_version) {
478 case TPACKET_V1:
479 h.h1->tp_sec = ts.tv_sec;
480 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
481 break;
482 case TPACKET_V2:
483 h.h2->tp_sec = ts.tv_sec;
484 h.h2->tp_nsec = ts.tv_nsec;
485 break;
486 case TPACKET_V3:
487 h.h3->tp_sec = ts.tv_sec;
488 h.h3->tp_nsec = ts.tv_nsec;
489 break;
490 default:
491 WARN(1, "TPACKET version not supported.\n");
492 BUG();
493 }
494
495 /* one flush is safe, as both fields always lie on the same cacheline */
496 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
497 smp_wmb();
498
499 return ts_status;
500}
501
502static void *packet_lookup_frame(struct packet_sock *po,
503 struct packet_ring_buffer *rb,
504 unsigned int position,
505 int status)
506{
507 unsigned int pg_vec_pos, frame_offset;
508 union tpacket_uhdr h;
509
510 pg_vec_pos = position / rb->frames_per_block;
511 frame_offset = position % rb->frames_per_block;
512
513 h.raw = rb->pg_vec[pg_vec_pos].buffer +
514 (frame_offset * rb->frame_size);
515
516 if (status != __packet_get_status(po, h.raw))
517 return NULL;
518
519 return h.raw;
520}
521
522static void *packet_current_frame(struct packet_sock *po,
523 struct packet_ring_buffer *rb,
524 int status)
525{
526 return packet_lookup_frame(po, rb, rb->head, status);
527}
528
529static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
530{
531 del_timer_sync(&pkc->retire_blk_timer);
532}
533
534static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
535 struct sk_buff_head *rb_queue)
536{
537 struct tpacket_kbdq_core *pkc;
538
539 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
540
541 spin_lock_bh(&rb_queue->lock);
542 pkc->delete_blk_timer = 1;
543 spin_unlock_bh(&rb_queue->lock);
544
545 prb_del_retire_blk_timer(pkc);
546}
547
548static void prb_setup_retire_blk_timer(struct packet_sock *po)
549{
550 struct tpacket_kbdq_core *pkc;
551
552 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
553 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
554 0);
555 pkc->retire_blk_timer.expires = jiffies;
556}
557
558static int prb_calc_retire_blk_tmo(struct packet_sock *po,
559 int blk_size_in_bytes)
560{
561 struct net_device *dev;
562 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
563 struct ethtool_link_ksettings ecmd;
564 int err;
565
566 rtnl_lock();
567 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
568 if (unlikely(!dev)) {
569 rtnl_unlock();
570 return DEFAULT_PRB_RETIRE_TOV;
571 }
572 err = __ethtool_get_link_ksettings(dev, &ecmd);
573 rtnl_unlock();
574 if (!err) {
575 /*
576 * If the link speed is so slow you don't really
577 * need to worry about perf anyways
578 */
579 if (ecmd.base.speed < SPEED_1000 ||
580 ecmd.base.speed == SPEED_UNKNOWN) {
581 return DEFAULT_PRB_RETIRE_TOV;
582 } else {
583 msec = 1;
584 div = ecmd.base.speed / 1000;
585 }
586 }
587
588 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
589
590 if (div)
591 mbits /= div;
592
593 tmo = mbits * msec;
594
595 if (div)
596 return tmo+1;
597 return tmo;
598}
599
600static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
601 union tpacket_req_u *req_u)
602{
603 p1->feature_req_word = req_u->req3.tp_feature_req_word;
604}
605
606static void init_prb_bdqc(struct packet_sock *po,
607 struct packet_ring_buffer *rb,
608 struct pgv *pg_vec,
609 union tpacket_req_u *req_u)
610{
611 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
612 struct tpacket_block_desc *pbd;
613
614 memset(p1, 0x0, sizeof(*p1));
615
616 p1->knxt_seq_num = 1;
617 p1->pkbdq = pg_vec;
618 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
619 p1->pkblk_start = pg_vec[0].buffer;
620 p1->kblk_size = req_u->req3.tp_block_size;
621 p1->knum_blocks = req_u->req3.tp_block_nr;
622 p1->hdrlen = po->tp_hdrlen;
623 p1->version = po->tp_version;
624 p1->last_kactive_blk_num = 0;
625 po->stats.stats3.tp_freeze_q_cnt = 0;
626 if (req_u->req3.tp_retire_blk_tov)
627 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
628 else
629 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
630 req_u->req3.tp_block_size);
631 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
632 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
633
634 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
635 prb_init_ft_ops(p1, req_u);
636 prb_setup_retire_blk_timer(po);
637 prb_open_block(p1, pbd);
638}
639
640/* Do NOT update the last_blk_num first.
641 * Assumes sk_buff_head lock is held.
642 */
643static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
644{
645 mod_timer(&pkc->retire_blk_timer,
646 jiffies + pkc->tov_in_jiffies);
647 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
648}
649
650/*
651 * Timer logic:
652 * 1) We refresh the timer only when we open a block.
653 * By doing this we don't waste cycles refreshing the timer
654 * on packet-by-packet basis.
655 *
656 * With a 1MB block-size, on a 1Gbps line, it will take
657 * i) ~8 ms to fill a block + ii) memcpy etc.
658 * In this cut we are not accounting for the memcpy time.
659 *
660 * So, if the user sets the 'tmo' to 10ms then the timer
661 * will never fire while the block is still getting filled
662 * (which is what we want). However, the user could choose
663 * to close a block early and that's fine.
664 *
665 * But when the timer does fire, we check whether or not to refresh it.
666 * Since the tmo granularity is in msecs, it is not too expensive
667 * to refresh the timer, lets say every '8' msecs.
668 * Either the user can set the 'tmo' or we can derive it based on
669 * a) line-speed and b) block-size.
670 * prb_calc_retire_blk_tmo() calculates the tmo.
671 *
672 */
673static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
674{
675 struct packet_sock *po =
676 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
677 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
678 unsigned int frozen;
679 struct tpacket_block_desc *pbd;
680
681 spin_lock(&po->sk.sk_receive_queue.lock);
682
683 frozen = prb_queue_frozen(pkc);
684 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
685
686 if (unlikely(pkc->delete_blk_timer))
687 goto out;
688
689 /* We only need to plug the race when the block is partially filled.
690 * tpacket_rcv:
691 * lock(); increment BLOCK_NUM_PKTS; unlock()
692 * copy_bits() is in progress ...
693 * timer fires on other cpu:
694 * we can't retire the current block because copy_bits
695 * is in progress.
696 *
697 */
698 if (BLOCK_NUM_PKTS(pbd)) {
699 while (atomic_read(&pkc->blk_fill_in_prog)) {
700 /* Waiting for skb_copy_bits to finish... */
701 cpu_relax();
702 }
703 }
704
705 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
706 if (!frozen) {
707 if (!BLOCK_NUM_PKTS(pbd)) {
708 /* An empty block. Just refresh the timer. */
709 goto refresh_timer;
710 }
711 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
712 if (!prb_dispatch_next_block(pkc, po))
713 goto refresh_timer;
714 else
715 goto out;
716 } else {
717 /* Case 1. Queue was frozen because user-space was
718 * lagging behind.
719 */
720 if (prb_curr_blk_in_use(pbd)) {
721 /*
722 * Ok, user-space is still behind.
723 * So just refresh the timer.
724 */
725 goto refresh_timer;
726 } else {
727 /* Case 2. queue was frozen,user-space caught up,
728 * now the link went idle && the timer fired.
729 * We don't have a block to close.So we open this
730 * block and restart the timer.
731 * opening a block thaws the queue,restarts timer
732 * Thawing/timer-refresh is a side effect.
733 */
734 prb_open_block(pkc, pbd);
735 goto out;
736 }
737 }
738 }
739
740refresh_timer:
741 _prb_refresh_rx_retire_blk_timer(pkc);
742
743out:
744 spin_unlock(&po->sk.sk_receive_queue.lock);
745}
746
747static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
748 struct tpacket_block_desc *pbd1, __u32 status)
749{
750 /* Flush everything minus the block header */
751
752#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
753 u8 *start, *end;
754
755 start = (u8 *)pbd1;
756
757 /* Skip the block header(we know header WILL fit in 4K) */
758 start += PAGE_SIZE;
759
760 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
761 for (; start < end; start += PAGE_SIZE)
762 flush_dcache_page(pgv_to_page(start));
763
764 smp_wmb();
765#endif
766
767 /* Now update the block status. */
768
769 BLOCK_STATUS(pbd1) = status;
770
771 /* Flush the block header */
772
773#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
774 start = (u8 *)pbd1;
775 flush_dcache_page(pgv_to_page(start));
776
777 smp_wmb();
778#endif
779}
780
781/*
782 * Side effect:
783 *
784 * 1) flush the block
785 * 2) Increment active_blk_num
786 *
787 * Note:We DONT refresh the timer on purpose.
788 * Because almost always the next block will be opened.
789 */
790static void prb_close_block(struct tpacket_kbdq_core *pkc1,
791 struct tpacket_block_desc *pbd1,
792 struct packet_sock *po, unsigned int stat)
793{
794 __u32 status = TP_STATUS_USER | stat;
795
796 struct tpacket3_hdr *last_pkt;
797 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
798 struct sock *sk = &po->sk;
799
800 if (po->stats.stats3.tp_drops)
801 status |= TP_STATUS_LOSING;
802
803 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
804 last_pkt->tp_next_offset = 0;
805
806 /* Get the ts of the last pkt */
807 if (BLOCK_NUM_PKTS(pbd1)) {
808 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
809 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
810 } else {
811 /* Ok, we tmo'd - so get the current time.
812 *
813 * It shouldn't really happen as we don't close empty
814 * blocks. See prb_retire_rx_blk_timer_expired().
815 */
816 struct timespec ts;
817 getnstimeofday(&ts);
818 h1->ts_last_pkt.ts_sec = ts.tv_sec;
819 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
820 }
821
822 smp_wmb();
823
824 /* Flush the block */
825 prb_flush_block(pkc1, pbd1, status);
826
827 sk->sk_data_ready(sk);
828
829 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
830}
831
832static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
833{
834 pkc->reset_pending_on_curr_blk = 0;
835}
836
837/*
838 * Side effect of opening a block:
839 *
840 * 1) prb_queue is thawed.
841 * 2) retire_blk_timer is refreshed.
842 *
843 */
844static void prb_open_block(struct tpacket_kbdq_core *pkc1,
845 struct tpacket_block_desc *pbd1)
846{
847 struct timespec ts;
848 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
849
850 smp_rmb();
851
852 /* We could have just memset this but we will lose the
853 * flexibility of making the priv area sticky
854 */
855
856 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
857 BLOCK_NUM_PKTS(pbd1) = 0;
858 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
859
860 getnstimeofday(&ts);
861
862 h1->ts_first_pkt.ts_sec = ts.tv_sec;
863 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
864
865 pkc1->pkblk_start = (char *)pbd1;
866 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
867
868 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
869 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
870
871 pbd1->version = pkc1->version;
872 pkc1->prev = pkc1->nxt_offset;
873 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
874
875 prb_thaw_queue(pkc1);
876 _prb_refresh_rx_retire_blk_timer(pkc1);
877
878 smp_wmb();
879}
880
881/*
882 * Queue freeze logic:
883 * 1) Assume tp_block_nr = 8 blocks.
884 * 2) At time 't0', user opens Rx ring.
885 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
886 * 4) user-space is either sleeping or processing block '0'.
887 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
888 * it will close block-7,loop around and try to fill block '0'.
889 * call-flow:
890 * __packet_lookup_frame_in_block
891 * prb_retire_current_block()
892 * prb_dispatch_next_block()
893 * |->(BLOCK_STATUS == USER) evaluates to true
894 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
895 * 6) Now there are two cases:
896 * 6.1) Link goes idle right after the queue is frozen.
897 * But remember, the last open_block() refreshed the timer.
898 * When this timer expires,it will refresh itself so that we can
899 * re-open block-0 in near future.
900 * 6.2) Link is busy and keeps on receiving packets. This is a simple
901 * case and __packet_lookup_frame_in_block will check if block-0
902 * is free and can now be re-used.
903 */
904static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
905 struct packet_sock *po)
906{
907 pkc->reset_pending_on_curr_blk = 1;
908 po->stats.stats3.tp_freeze_q_cnt++;
909}
910
911#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
912
913/*
914 * If the next block is free then we will dispatch it
915 * and return a good offset.
916 * Else, we will freeze the queue.
917 * So, caller must check the return value.
918 */
919static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
920 struct packet_sock *po)
921{
922 struct tpacket_block_desc *pbd;
923
924 smp_rmb();
925
926 /* 1. Get current block num */
927 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
928
929 /* 2. If this block is currently in_use then freeze the queue */
930 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
931 prb_freeze_queue(pkc, po);
932 return NULL;
933 }
934
935 /*
936 * 3.
937 * open this block and return the offset where the first packet
938 * needs to get stored.
939 */
940 prb_open_block(pkc, pbd);
941 return (void *)pkc->nxt_offset;
942}
943
944static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
945 struct packet_sock *po, unsigned int status)
946{
947 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
948
949 /* retire/close the current block */
950 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
951 /*
952 * Plug the case where copy_bits() is in progress on
953 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
954 * have space to copy the pkt in the current block and
955 * called prb_retire_current_block()
956 *
957 * We don't need to worry about the TMO case because
958 * the timer-handler already handled this case.
959 */
960 if (!(status & TP_STATUS_BLK_TMO)) {
961 while (atomic_read(&pkc->blk_fill_in_prog)) {
962 /* Waiting for skb_copy_bits to finish... */
963 cpu_relax();
964 }
965 }
966 prb_close_block(pkc, pbd, po, status);
967 return;
968 }
969}
970
971static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
972{
973 return TP_STATUS_USER & BLOCK_STATUS(pbd);
974}
975
976static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
977{
978 return pkc->reset_pending_on_curr_blk;
979}
980
981static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
982{
983 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
984 atomic_dec(&pkc->blk_fill_in_prog);
985}
986
987static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
988 struct tpacket3_hdr *ppd)
989{
990 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
991}
992
993static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
994 struct tpacket3_hdr *ppd)
995{
996 ppd->hv1.tp_rxhash = 0;
997}
998
999static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1000 struct tpacket3_hdr *ppd)
1001{
1002 if (skb_vlan_tag_present(pkc->skb)) {
1003 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1004 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1005 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1006 } else {
1007 ppd->hv1.tp_vlan_tci = 0;
1008 ppd->hv1.tp_vlan_tpid = 0;
1009 ppd->tp_status = TP_STATUS_AVAILABLE;
1010 }
1011}
1012
1013static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1014 struct tpacket3_hdr *ppd)
1015{
1016 ppd->hv1.tp_padding = 0;
1017 prb_fill_vlan_info(pkc, ppd);
1018
1019 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1020 prb_fill_rxhash(pkc, ppd);
1021 else
1022 prb_clear_rxhash(pkc, ppd);
1023}
1024
1025static void prb_fill_curr_block(char *curr,
1026 struct tpacket_kbdq_core *pkc,
1027 struct tpacket_block_desc *pbd,
1028 unsigned int len)
1029{
1030 struct tpacket3_hdr *ppd;
1031
1032 ppd = (struct tpacket3_hdr *)curr;
1033 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1034 pkc->prev = curr;
1035 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1036 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1037 BLOCK_NUM_PKTS(pbd) += 1;
1038 atomic_inc(&pkc->blk_fill_in_prog);
1039 prb_run_all_ft_ops(pkc, ppd);
1040}
1041
1042/* Assumes caller has the sk->rx_queue.lock */
1043static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1044 struct sk_buff *skb,
1045 int status,
1046 unsigned int len
1047 )
1048{
1049 struct tpacket_kbdq_core *pkc;
1050 struct tpacket_block_desc *pbd;
1051 char *curr, *end;
1052
1053 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1054 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1055
1056 /* Queue is frozen when user space is lagging behind */
1057 if (prb_queue_frozen(pkc)) {
1058 /*
1059 * Check if that last block which caused the queue to freeze,
1060 * is still in_use by user-space.
1061 */
1062 if (prb_curr_blk_in_use(pbd)) {
1063 /* Can't record this packet */
1064 return NULL;
1065 } else {
1066 /*
1067 * Ok, the block was released by user-space.
1068 * Now let's open that block.
1069 * opening a block also thaws the queue.
1070 * Thawing is a side effect.
1071 */
1072 prb_open_block(pkc, pbd);
1073 }
1074 }
1075
1076 smp_mb();
1077 curr = pkc->nxt_offset;
1078 pkc->skb = skb;
1079 end = (char *)pbd + pkc->kblk_size;
1080
1081 /* first try the current block */
1082 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1083 prb_fill_curr_block(curr, pkc, pbd, len);
1084 return (void *)curr;
1085 }
1086
1087 /* Ok, close the current block */
1088 prb_retire_current_block(pkc, po, 0);
1089
1090 /* Now, try to dispatch the next block */
1091 curr = (char *)prb_dispatch_next_block(pkc, po);
1092 if (curr) {
1093 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1094 prb_fill_curr_block(curr, pkc, pbd, len);
1095 return (void *)curr;
1096 }
1097
1098 /*
1099 * No free blocks are available.user_space hasn't caught up yet.
1100 * Queue was just frozen and now this packet will get dropped.
1101 */
1102 return NULL;
1103}
1104
1105static void *packet_current_rx_frame(struct packet_sock *po,
1106 struct sk_buff *skb,
1107 int status, unsigned int len)
1108{
1109 char *curr = NULL;
1110 switch (po->tp_version) {
1111 case TPACKET_V1:
1112 case TPACKET_V2:
1113 curr = packet_lookup_frame(po, &po->rx_ring,
1114 po->rx_ring.head, status);
1115 return curr;
1116 case TPACKET_V3:
1117 return __packet_lookup_frame_in_block(po, skb, status, len);
1118 default:
1119 WARN(1, "TPACKET version not supported\n");
1120 BUG();
1121 return NULL;
1122 }
1123}
1124
1125static void *prb_lookup_block(struct packet_sock *po,
1126 struct packet_ring_buffer *rb,
1127 unsigned int idx,
1128 int status)
1129{
1130 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1131 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1132
1133 if (status != BLOCK_STATUS(pbd))
1134 return NULL;
1135 return pbd;
1136}
1137
1138static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1139{
1140 unsigned int prev;
1141 if (rb->prb_bdqc.kactive_blk_num)
1142 prev = rb->prb_bdqc.kactive_blk_num-1;
1143 else
1144 prev = rb->prb_bdqc.knum_blocks-1;
1145 return prev;
1146}
1147
1148/* Assumes caller has held the rx_queue.lock */
1149static void *__prb_previous_block(struct packet_sock *po,
1150 struct packet_ring_buffer *rb,
1151 int status)
1152{
1153 unsigned int previous = prb_previous_blk_num(rb);
1154 return prb_lookup_block(po, rb, previous, status);
1155}
1156
1157static void *packet_previous_rx_frame(struct packet_sock *po,
1158 struct packet_ring_buffer *rb,
1159 int status)
1160{
1161 if (po->tp_version <= TPACKET_V2)
1162 return packet_previous_frame(po, rb, status);
1163
1164 return __prb_previous_block(po, rb, status);
1165}
1166
1167static void packet_increment_rx_head(struct packet_sock *po,
1168 struct packet_ring_buffer *rb)
1169{
1170 switch (po->tp_version) {
1171 case TPACKET_V1:
1172 case TPACKET_V2:
1173 return packet_increment_head(rb);
1174 case TPACKET_V3:
1175 default:
1176 WARN(1, "TPACKET version not supported.\n");
1177 BUG();
1178 return;
1179 }
1180}
1181
1182static void *packet_previous_frame(struct packet_sock *po,
1183 struct packet_ring_buffer *rb,
1184 int status)
1185{
1186 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1187 return packet_lookup_frame(po, rb, previous, status);
1188}
1189
1190static void packet_increment_head(struct packet_ring_buffer *buff)
1191{
1192 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1193}
1194
1195static void packet_inc_pending(struct packet_ring_buffer *rb)
1196{
1197 this_cpu_inc(*rb->pending_refcnt);
1198}
1199
1200static void packet_dec_pending(struct packet_ring_buffer *rb)
1201{
1202 this_cpu_dec(*rb->pending_refcnt);
1203}
1204
1205static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1206{
1207 unsigned int refcnt = 0;
1208 int cpu;
1209
1210 /* We don't use pending refcount in rx_ring. */
1211 if (rb->pending_refcnt == NULL)
1212 return 0;
1213
1214 for_each_possible_cpu(cpu)
1215 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1216
1217 return refcnt;
1218}
1219
1220static int packet_alloc_pending(struct packet_sock *po)
1221{
1222 po->rx_ring.pending_refcnt = NULL;
1223
1224 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1225 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1226 return -ENOBUFS;
1227
1228 return 0;
1229}
1230
1231static void packet_free_pending(struct packet_sock *po)
1232{
1233 free_percpu(po->tx_ring.pending_refcnt);
1234}
1235
1236#define ROOM_POW_OFF 2
1237#define ROOM_NONE 0x0
1238#define ROOM_LOW 0x1
1239#define ROOM_NORMAL 0x2
1240
1241static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1242{
1243 int idx, len;
1244
1245 len = po->rx_ring.frame_max + 1;
1246 idx = po->rx_ring.head;
1247 if (pow_off)
1248 idx += len >> pow_off;
1249 if (idx >= len)
1250 idx -= len;
1251 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1252}
1253
1254static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1255{
1256 int idx, len;
1257
1258 len = po->rx_ring.prb_bdqc.knum_blocks;
1259 idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1260 if (pow_off)
1261 idx += len >> pow_off;
1262 if (idx >= len)
1263 idx -= len;
1264 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1265}
1266
1267static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1268{
1269 struct sock *sk = &po->sk;
1270 int ret = ROOM_NONE;
1271
1272 if (po->prot_hook.func != tpacket_rcv) {
1273 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1274 - (skb ? skb->truesize : 0);
1275 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1276 return ROOM_NORMAL;
1277 else if (avail > 0)
1278 return ROOM_LOW;
1279 else
1280 return ROOM_NONE;
1281 }
1282
1283 if (po->tp_version == TPACKET_V3) {
1284 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1285 ret = ROOM_NORMAL;
1286 else if (__tpacket_v3_has_room(po, 0))
1287 ret = ROOM_LOW;
1288 } else {
1289 if (__tpacket_has_room(po, ROOM_POW_OFF))
1290 ret = ROOM_NORMAL;
1291 else if (__tpacket_has_room(po, 0))
1292 ret = ROOM_LOW;
1293 }
1294
1295 return ret;
1296}
1297
1298static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1299{
1300 int ret;
1301 bool has_room;
1302
1303 spin_lock_bh(&po->sk.sk_receive_queue.lock);
1304 ret = __packet_rcv_has_room(po, skb);
1305 has_room = ret == ROOM_NORMAL;
1306 if (po->pressure == has_room)
1307 po->pressure = !has_room;
1308 spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1309
1310 return ret;
1311}
1312
1313static void packet_sock_destruct(struct sock *sk)
1314{
1315 skb_queue_purge(&sk->sk_error_queue);
1316
1317 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1318 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1319
1320 if (!sock_flag(sk, SOCK_DEAD)) {
1321 pr_err("Attempt to release alive packet socket: %p\n", sk);
1322 return;
1323 }
1324
1325 sk_refcnt_debug_dec(sk);
1326}
1327
1328static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1329{
1330 u32 rxhash;
1331 int i, count = 0;
1332
1333 rxhash = skb_get_hash(skb);
1334 for (i = 0; i < ROLLOVER_HLEN; i++)
1335 if (po->rollover->history[i] == rxhash)
1336 count++;
1337
1338 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1339 return count > (ROLLOVER_HLEN >> 1);
1340}
1341
1342static unsigned int fanout_demux_hash(struct packet_fanout *f,
1343 struct sk_buff *skb,
1344 unsigned int num)
1345{
1346 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1347}
1348
1349static unsigned int fanout_demux_lb(struct packet_fanout *f,
1350 struct sk_buff *skb,
1351 unsigned int num)
1352{
1353 unsigned int val = atomic_inc_return(&f->rr_cur);
1354
1355 return val % num;
1356}
1357
1358static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1359 struct sk_buff *skb,
1360 unsigned int num)
1361{
1362 return smp_processor_id() % num;
1363}
1364
1365static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1366 struct sk_buff *skb,
1367 unsigned int num)
1368{
1369 return prandom_u32_max(num);
1370}
1371
1372static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1373 struct sk_buff *skb,
1374 unsigned int idx, bool try_self,
1375 unsigned int num)
1376{
1377 struct packet_sock *po, *po_next, *po_skip = NULL;
1378 unsigned int i, j, room = ROOM_NONE;
1379
1380 po = pkt_sk(f->arr[idx]);
1381
1382 if (try_self) {
1383 room = packet_rcv_has_room(po, skb);
1384 if (room == ROOM_NORMAL ||
1385 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1386 return idx;
1387 po_skip = po;
1388 }
1389
1390 i = j = min_t(int, po->rollover->sock, num - 1);
1391 do {
1392 po_next = pkt_sk(f->arr[i]);
1393 if (po_next != po_skip && !po_next->pressure &&
1394 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1395 if (i != j)
1396 po->rollover->sock = i;
1397 atomic_long_inc(&po->rollover->num);
1398 if (room == ROOM_LOW)
1399 atomic_long_inc(&po->rollover->num_huge);
1400 return i;
1401 }
1402
1403 if (++i == num)
1404 i = 0;
1405 } while (i != j);
1406
1407 atomic_long_inc(&po->rollover->num_failed);
1408 return idx;
1409}
1410
1411static unsigned int fanout_demux_qm(struct packet_fanout *f,
1412 struct sk_buff *skb,
1413 unsigned int num)
1414{
1415 return skb_get_queue_mapping(skb) % num;
1416}
1417
1418static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1419 struct sk_buff *skb,
1420 unsigned int num)
1421{
1422 struct bpf_prog *prog;
1423 unsigned int ret = 0;
1424
1425 rcu_read_lock();
1426 prog = rcu_dereference(f->bpf_prog);
1427 if (prog)
1428 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1429 rcu_read_unlock();
1430
1431 return ret;
1432}
1433
1434static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1435{
1436 return f->flags & (flag >> 8);
1437}
1438
1439static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1440 struct packet_type *pt, struct net_device *orig_dev)
1441{
1442 struct packet_fanout *f = pt->af_packet_priv;
1443 unsigned int num = READ_ONCE(f->num_members);
1444 struct net *net = read_pnet(&f->net);
1445 struct packet_sock *po;
1446 unsigned int idx;
1447
1448 if (!net_eq(dev_net(dev), net) || !num) {
1449 kfree_skb(skb);
1450 return 0;
1451 }
1452
1453 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1454 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1455 if (!skb)
1456 return 0;
1457 }
1458 switch (f->type) {
1459 case PACKET_FANOUT_HASH:
1460 default:
1461 idx = fanout_demux_hash(f, skb, num);
1462 break;
1463 case PACKET_FANOUT_LB:
1464 idx = fanout_demux_lb(f, skb, num);
1465 break;
1466 case PACKET_FANOUT_CPU:
1467 idx = fanout_demux_cpu(f, skb, num);
1468 break;
1469 case PACKET_FANOUT_RND:
1470 idx = fanout_demux_rnd(f, skb, num);
1471 break;
1472 case PACKET_FANOUT_QM:
1473 idx = fanout_demux_qm(f, skb, num);
1474 break;
1475 case PACKET_FANOUT_ROLLOVER:
1476 idx = fanout_demux_rollover(f, skb, 0, false, num);
1477 break;
1478 case PACKET_FANOUT_CBPF:
1479 case PACKET_FANOUT_EBPF:
1480 idx = fanout_demux_bpf(f, skb, num);
1481 break;
1482 }
1483
1484 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1485 idx = fanout_demux_rollover(f, skb, idx, true, num);
1486
1487 po = pkt_sk(f->arr[idx]);
1488 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1489}
1490
1491DEFINE_MUTEX(fanout_mutex);
1492EXPORT_SYMBOL_GPL(fanout_mutex);
1493static LIST_HEAD(fanout_list);
1494static u16 fanout_next_id;
1495
1496static void __fanout_link(struct sock *sk, struct packet_sock *po)
1497{
1498 struct packet_fanout *f = po->fanout;
1499
1500 spin_lock(&f->lock);
1501 f->arr[f->num_members] = sk;
1502 smp_wmb();
1503 f->num_members++;
1504 if (f->num_members == 1)
1505 dev_add_pack(&f->prot_hook);
1506 spin_unlock(&f->lock);
1507}
1508
1509static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1510{
1511 struct packet_fanout *f = po->fanout;
1512 int i;
1513
1514 spin_lock(&f->lock);
1515 for (i = 0; i < f->num_members; i++) {
1516 if (f->arr[i] == sk)
1517 break;
1518 }
1519 BUG_ON(i >= f->num_members);
1520 f->arr[i] = f->arr[f->num_members - 1];
1521 f->num_members--;
1522 if (f->num_members == 0)
1523 __dev_remove_pack(&f->prot_hook);
1524 spin_unlock(&f->lock);
1525}
1526
1527static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1528{
1529 if (sk->sk_family != PF_PACKET)
1530 return false;
1531
1532 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1533}
1534
1535static void fanout_init_data(struct packet_fanout *f)
1536{
1537 switch (f->type) {
1538 case PACKET_FANOUT_LB:
1539 atomic_set(&f->rr_cur, 0);
1540 break;
1541 case PACKET_FANOUT_CBPF:
1542 case PACKET_FANOUT_EBPF:
1543 RCU_INIT_POINTER(f->bpf_prog, NULL);
1544 break;
1545 }
1546}
1547
1548static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1549{
1550 struct bpf_prog *old;
1551
1552 spin_lock(&f->lock);
1553 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1554 rcu_assign_pointer(f->bpf_prog, new);
1555 spin_unlock(&f->lock);
1556
1557 if (old) {
1558 synchronize_net();
1559 bpf_prog_destroy(old);
1560 }
1561}
1562
1563static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1564 unsigned int len)
1565{
1566 struct bpf_prog *new;
1567 struct sock_fprog fprog;
1568 int ret;
1569
1570 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1571 return -EPERM;
1572 if (len != sizeof(fprog))
1573 return -EINVAL;
1574 if (copy_from_user(&fprog, data, len))
1575 return -EFAULT;
1576
1577 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1578 if (ret)
1579 return ret;
1580
1581 __fanout_set_data_bpf(po->fanout, new);
1582 return 0;
1583}
1584
1585static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1586 unsigned int len)
1587{
1588 struct bpf_prog *new;
1589 u32 fd;
1590
1591 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1592 return -EPERM;
1593 if (len != sizeof(fd))
1594 return -EINVAL;
1595 if (copy_from_user(&fd, data, len))
1596 return -EFAULT;
1597
1598 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1599 if (IS_ERR(new))
1600 return PTR_ERR(new);
1601
1602 __fanout_set_data_bpf(po->fanout, new);
1603 return 0;
1604}
1605
1606static int fanout_set_data(struct packet_sock *po, char __user *data,
1607 unsigned int len)
1608{
1609 switch (po->fanout->type) {
1610 case PACKET_FANOUT_CBPF:
1611 return fanout_set_data_cbpf(po, data, len);
1612 case PACKET_FANOUT_EBPF:
1613 return fanout_set_data_ebpf(po, data, len);
1614 default:
1615 return -EINVAL;
1616 };
1617}
1618
1619static void fanout_release_data(struct packet_fanout *f)
1620{
1621 switch (f->type) {
1622 case PACKET_FANOUT_CBPF:
1623 case PACKET_FANOUT_EBPF:
1624 __fanout_set_data_bpf(f, NULL);
1625 };
1626}
1627
1628static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1629{
1630 struct packet_fanout *f;
1631
1632 list_for_each_entry(f, &fanout_list, list) {
1633 if (f->id == candidate_id &&
1634 read_pnet(&f->net) == sock_net(sk)) {
1635 return false;
1636 }
1637 }
1638 return true;
1639}
1640
1641static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1642{
1643 u16 id = fanout_next_id;
1644
1645 do {
1646 if (__fanout_id_is_free(sk, id)) {
1647 *new_id = id;
1648 fanout_next_id = id + 1;
1649 return true;
1650 }
1651
1652 id++;
1653 } while (id != fanout_next_id);
1654
1655 return false;
1656}
1657
1658static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1659{
1660 struct packet_rollover *rollover = NULL;
1661 struct packet_sock *po = pkt_sk(sk);
1662 struct packet_fanout *f, *match;
1663 u8 type = type_flags & 0xff;
1664 u8 flags = type_flags >> 8;
1665 int err;
1666
1667 switch (type) {
1668 case PACKET_FANOUT_ROLLOVER:
1669 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1670 return -EINVAL;
1671 case PACKET_FANOUT_HASH:
1672 case PACKET_FANOUT_LB:
1673 case PACKET_FANOUT_CPU:
1674 case PACKET_FANOUT_RND:
1675 case PACKET_FANOUT_QM:
1676 case PACKET_FANOUT_CBPF:
1677 case PACKET_FANOUT_EBPF:
1678 break;
1679 default:
1680 return -EINVAL;
1681 }
1682
1683 mutex_lock(&fanout_mutex);
1684
1685 err = -EALREADY;
1686 if (po->fanout)
1687 goto out;
1688
1689 if (type == PACKET_FANOUT_ROLLOVER ||
1690 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1691 err = -ENOMEM;
1692 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1693 if (!rollover)
1694 goto out;
1695 atomic_long_set(&rollover->num, 0);
1696 atomic_long_set(&rollover->num_huge, 0);
1697 atomic_long_set(&rollover->num_failed, 0);
1698 }
1699
1700 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1701 if (id != 0) {
1702 err = -EINVAL;
1703 goto out;
1704 }
1705 if (!fanout_find_new_id(sk, &id)) {
1706 err = -ENOMEM;
1707 goto out;
1708 }
1709 /* ephemeral flag for the first socket in the group: drop it */
1710 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1711 }
1712
1713 match = NULL;
1714 list_for_each_entry(f, &fanout_list, list) {
1715 if (f->id == id &&
1716 read_pnet(&f->net) == sock_net(sk)) {
1717 match = f;
1718 break;
1719 }
1720 }
1721 err = -EINVAL;
1722 if (match && match->flags != flags)
1723 goto out;
1724 if (!match) {
1725 err = -ENOMEM;
1726 match = kzalloc(sizeof(*match), GFP_KERNEL);
1727 if (!match)
1728 goto out;
1729 write_pnet(&match->net, sock_net(sk));
1730 match->id = id;
1731 match->type = type;
1732 match->flags = flags;
1733 INIT_LIST_HEAD(&match->list);
1734 spin_lock_init(&match->lock);
1735 refcount_set(&match->sk_ref, 0);
1736 fanout_init_data(match);
1737 match->prot_hook.type = po->prot_hook.type;
1738 match->prot_hook.dev = po->prot_hook.dev;
1739 match->prot_hook.func = packet_rcv_fanout;
1740 match->prot_hook.af_packet_priv = match;
1741 match->prot_hook.id_match = match_fanout_group;
1742 list_add(&match->list, &fanout_list);
1743 }
1744 err = -EINVAL;
1745
1746 spin_lock(&po->bind_lock);
1747 if (po->running &&
1748 match->type == type &&
1749 match->prot_hook.type == po->prot_hook.type &&
1750 match->prot_hook.dev == po->prot_hook.dev) {
1751 err = -ENOSPC;
1752 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1753 __dev_remove_pack(&po->prot_hook);
1754 po->fanout = match;
1755 po->rollover = rollover;
1756 rollover = NULL;
1757 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1758 __fanout_link(sk, po);
1759 err = 0;
1760 }
1761 }
1762 spin_unlock(&po->bind_lock);
1763
1764 if (err && !refcount_read(&match->sk_ref)) {
1765 list_del(&match->list);
1766 kfree(match);
1767 }
1768
1769out:
1770 kfree(rollover);
1771 mutex_unlock(&fanout_mutex);
1772 return err;
1773}
1774
1775/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1776 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1777 * It is the responsibility of the caller to call fanout_release_data() and
1778 * free the returned packet_fanout (after synchronize_net())
1779 */
1780static struct packet_fanout *fanout_release(struct sock *sk)
1781{
1782 struct packet_sock *po = pkt_sk(sk);
1783 struct packet_fanout *f;
1784
1785 mutex_lock(&fanout_mutex);
1786 f = po->fanout;
1787 if (f) {
1788 po->fanout = NULL;
1789
1790 if (refcount_dec_and_test(&f->sk_ref))
1791 list_del(&f->list);
1792 else
1793 f = NULL;
1794 }
1795 mutex_unlock(&fanout_mutex);
1796
1797 return f;
1798}
1799
1800static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1801 struct sk_buff *skb)
1802{
1803 /* Earlier code assumed this would be a VLAN pkt, double-check
1804 * this now that we have the actual packet in hand. We can only
1805 * do this check on Ethernet devices.
1806 */
1807 if (unlikely(dev->type != ARPHRD_ETHER))
1808 return false;
1809
1810 skb_reset_mac_header(skb);
1811 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1812}
1813
1814static const struct proto_ops packet_ops;
1815
1816static const struct proto_ops packet_ops_spkt;
1817
1818static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1819 struct packet_type *pt, struct net_device *orig_dev)
1820{
1821 struct sock *sk;
1822 struct sockaddr_pkt *spkt;
1823
1824 /*
1825 * When we registered the protocol we saved the socket in the data
1826 * field for just this event.
1827 */
1828
1829 sk = pt->af_packet_priv;
1830
1831 /*
1832 * Yank back the headers [hope the device set this
1833 * right or kerboom...]
1834 *
1835 * Incoming packets have ll header pulled,
1836 * push it back.
1837 *
1838 * For outgoing ones skb->data == skb_mac_header(skb)
1839 * so that this procedure is noop.
1840 */
1841
1842 if (skb->pkt_type == PACKET_LOOPBACK)
1843 goto out;
1844
1845 if (!net_eq(dev_net(dev), sock_net(sk)))
1846 goto out;
1847
1848 skb = skb_share_check(skb, GFP_ATOMIC);
1849 if (skb == NULL)
1850 goto oom;
1851
1852 /* drop any routing info */
1853 skb_dst_drop(skb);
1854
1855 /* drop conntrack reference */
1856 nf_reset(skb);
1857
1858 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1859
1860 skb_push(skb, skb->data - skb_mac_header(skb));
1861
1862 /*
1863 * The SOCK_PACKET socket receives _all_ frames.
1864 */
1865
1866 spkt->spkt_family = dev->type;
1867 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1868 spkt->spkt_protocol = skb->protocol;
1869
1870 /*
1871 * Charge the memory to the socket. This is done specifically
1872 * to prevent sockets using all the memory up.
1873 */
1874
1875 if (sock_queue_rcv_skb(sk, skb) == 0)
1876 return 0;
1877
1878out:
1879 kfree_skb(skb);
1880oom:
1881 return 0;
1882}
1883
1884
1885/*
1886 * Output a raw packet to a device layer. This bypasses all the other
1887 * protocol layers and you must therefore supply it with a complete frame
1888 */
1889
1890static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1891 size_t len)
1892{
1893 struct sock *sk = sock->sk;
1894 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1895 struct sk_buff *skb = NULL;
1896 struct net_device *dev;
1897 struct sockcm_cookie sockc;
1898 __be16 proto = 0;
1899 int err;
1900 int extra_len = 0;
1901
1902 /*
1903 * Get and verify the address.
1904 */
1905
1906 if (saddr) {
1907 if (msg->msg_namelen < sizeof(struct sockaddr))
1908 return -EINVAL;
1909 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1910 proto = saddr->spkt_protocol;
1911 } else
1912 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1913
1914 /*
1915 * Find the device first to size check it
1916 */
1917
1918 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1919retry:
1920 rcu_read_lock();
1921 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1922 err = -ENODEV;
1923 if (dev == NULL)
1924 goto out_unlock;
1925
1926 err = -ENETDOWN;
1927 if (!(dev->flags & IFF_UP))
1928 goto out_unlock;
1929
1930 /*
1931 * You may not queue a frame bigger than the mtu. This is the lowest level
1932 * raw protocol and you must do your own fragmentation at this level.
1933 */
1934
1935 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1936 if (!netif_supports_nofcs(dev)) {
1937 err = -EPROTONOSUPPORT;
1938 goto out_unlock;
1939 }
1940 extra_len = 4; /* We're doing our own CRC */
1941 }
1942
1943 err = -EMSGSIZE;
1944 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1945 goto out_unlock;
1946
1947 if (!skb) {
1948 size_t reserved = LL_RESERVED_SPACE(dev);
1949 int tlen = dev->needed_tailroom;
1950 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1951
1952 rcu_read_unlock();
1953 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1954 if (skb == NULL)
1955 return -ENOBUFS;
1956 /* FIXME: Save some space for broken drivers that write a hard
1957 * header at transmission time by themselves. PPP is the notable
1958 * one here. This should really be fixed at the driver level.
1959 */
1960 skb_reserve(skb, reserved);
1961 skb_reset_network_header(skb);
1962
1963 /* Try to align data part correctly */
1964 if (hhlen) {
1965 skb->data -= hhlen;
1966 skb->tail -= hhlen;
1967 if (len < hhlen)
1968 skb_reset_network_header(skb);
1969 }
1970 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1971 if (err)
1972 goto out_free;
1973 goto retry;
1974 }
1975
1976 if (!dev_validate_header(dev, skb->data, len)) {
1977 err = -EINVAL;
1978 goto out_unlock;
1979 }
1980 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1981 !packet_extra_vlan_len_allowed(dev, skb)) {
1982 err = -EMSGSIZE;
1983 goto out_unlock;
1984 }
1985
1986 sockc.tsflags = sk->sk_tsflags;
1987 if (msg->msg_controllen) {
1988 err = sock_cmsg_send(sk, msg, &sockc);
1989 if (unlikely(err))
1990 goto out_unlock;
1991 }
1992
1993 skb->protocol = proto;
1994 skb->dev = dev;
1995 skb->priority = sk->sk_priority;
1996 skb->mark = sk->sk_mark;
1997
1998 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
1999
2000 if (unlikely(extra_len == 4))
2001 skb->no_fcs = 1;
2002
2003 skb_probe_transport_header(skb, 0);
2004
2005 dev_queue_xmit(skb);
2006 rcu_read_unlock();
2007 return len;
2008
2009out_unlock:
2010 rcu_read_unlock();
2011out_free:
2012 kfree_skb(skb);
2013 return err;
2014}
2015
2016static unsigned int run_filter(struct sk_buff *skb,
2017 const struct sock *sk,
2018 unsigned int res)
2019{
2020 struct sk_filter *filter;
2021
2022 rcu_read_lock();
2023 filter = rcu_dereference(sk->sk_filter);
2024 if (filter != NULL)
2025 res = bpf_prog_run_clear_cb(filter->prog, skb);
2026 rcu_read_unlock();
2027
2028 return res;
2029}
2030
2031static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2032 size_t *len)
2033{
2034 struct virtio_net_hdr vnet_hdr;
2035
2036 if (*len < sizeof(vnet_hdr))
2037 return -EINVAL;
2038 *len -= sizeof(vnet_hdr);
2039
2040 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true))
2041 return -EINVAL;
2042
2043 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2044}
2045
2046/*
2047 * This function makes lazy skb cloning in hope that most of packets
2048 * are discarded by BPF.
2049 *
2050 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2051 * and skb->cb are mangled. It works because (and until) packets
2052 * falling here are owned by current CPU. Output packets are cloned
2053 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2054 * sequencially, so that if we return skb to original state on exit,
2055 * we will not harm anyone.
2056 */
2057
2058static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2059 struct packet_type *pt, struct net_device *orig_dev)
2060{
2061 struct sock *sk;
2062 struct sockaddr_ll *sll;
2063 struct packet_sock *po;
2064 u8 *skb_head = skb->data;
2065 int skb_len = skb->len;
2066 unsigned int snaplen, res;
2067 bool is_drop_n_account = false;
2068
2069 if (skb->pkt_type == PACKET_LOOPBACK)
2070 goto drop;
2071
2072 sk = pt->af_packet_priv;
2073 po = pkt_sk(sk);
2074
2075 if (!net_eq(dev_net(dev), sock_net(sk)))
2076 goto drop;
2077
2078 skb->dev = dev;
2079
2080 if (dev->header_ops) {
2081 /* The device has an explicit notion of ll header,
2082 * exported to higher levels.
2083 *
2084 * Otherwise, the device hides details of its frame
2085 * structure, so that corresponding packet head is
2086 * never delivered to user.
2087 */
2088 if (sk->sk_type != SOCK_DGRAM)
2089 skb_push(skb, skb->data - skb_mac_header(skb));
2090 else if (skb->pkt_type == PACKET_OUTGOING) {
2091 /* Special case: outgoing packets have ll header at head */
2092 skb_pull(skb, skb_network_offset(skb));
2093 }
2094 }
2095
2096 snaplen = skb->len;
2097
2098 res = run_filter(skb, sk, snaplen);
2099 if (!res)
2100 goto drop_n_restore;
2101 if (snaplen > res)
2102 snaplen = res;
2103
2104 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2105 goto drop_n_acct;
2106
2107 if (skb_shared(skb)) {
2108 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2109 if (nskb == NULL)
2110 goto drop_n_acct;
2111
2112 if (skb_head != skb->data) {
2113 skb->data = skb_head;
2114 skb->len = skb_len;
2115 }
2116 consume_skb(skb);
2117 skb = nskb;
2118 }
2119
2120 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2121
2122 sll = &PACKET_SKB_CB(skb)->sa.ll;
2123 sll->sll_hatype = dev->type;
2124 sll->sll_pkttype = skb->pkt_type;
2125 if (unlikely(po->origdev))
2126 sll->sll_ifindex = orig_dev->ifindex;
2127 else
2128 sll->sll_ifindex = dev->ifindex;
2129
2130 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2131
2132 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2133 * Use their space for storing the original skb length.
2134 */
2135 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2136
2137 if (pskb_trim(skb, snaplen))
2138 goto drop_n_acct;
2139
2140 skb_set_owner_r(skb, sk);
2141 skb->dev = NULL;
2142 skb_dst_drop(skb);
2143
2144 /* drop conntrack reference */
2145 nf_reset(skb);
2146
2147 spin_lock(&sk->sk_receive_queue.lock);
2148 po->stats.stats1.tp_packets++;
2149 sock_skb_set_dropcount(sk, skb);
2150 __skb_queue_tail(&sk->sk_receive_queue, skb);
2151 spin_unlock(&sk->sk_receive_queue.lock);
2152 sk->sk_data_ready(sk);
2153 return 0;
2154
2155drop_n_acct:
2156 is_drop_n_account = true;
2157 spin_lock(&sk->sk_receive_queue.lock);
2158 po->stats.stats1.tp_drops++;
2159 atomic_inc(&sk->sk_drops);
2160 spin_unlock(&sk->sk_receive_queue.lock);
2161
2162drop_n_restore:
2163 if (skb_head != skb->data && skb_shared(skb)) {
2164 skb->data = skb_head;
2165 skb->len = skb_len;
2166 }
2167drop:
2168 if (!is_drop_n_account)
2169 consume_skb(skb);
2170 else
2171 kfree_skb(skb);
2172 return 0;
2173}
2174
2175static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2176 struct packet_type *pt, struct net_device *orig_dev)
2177{
2178 struct sock *sk;
2179 struct packet_sock *po;
2180 struct sockaddr_ll *sll;
2181 union tpacket_uhdr h;
2182 u8 *skb_head = skb->data;
2183 int skb_len = skb->len;
2184 unsigned int snaplen, res;
2185 unsigned long status = TP_STATUS_USER;
2186 unsigned short macoff, netoff, hdrlen;
2187 struct sk_buff *copy_skb = NULL;
2188 struct timespec ts;
2189 __u32 ts_status;
2190 bool is_drop_n_account = false;
2191 bool do_vnet = false;
2192
2193 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2194 * We may add members to them until current aligned size without forcing
2195 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2196 */
2197 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2198 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2199
2200 if (skb->pkt_type == PACKET_LOOPBACK)
2201 goto drop;
2202
2203 sk = pt->af_packet_priv;
2204 po = pkt_sk(sk);
2205
2206 if (!net_eq(dev_net(dev), sock_net(sk)))
2207 goto drop;
2208
2209 if (dev->header_ops) {
2210 if (sk->sk_type != SOCK_DGRAM)
2211 skb_push(skb, skb->data - skb_mac_header(skb));
2212 else if (skb->pkt_type == PACKET_OUTGOING) {
2213 /* Special case: outgoing packets have ll header at head */
2214 skb_pull(skb, skb_network_offset(skb));
2215 }
2216 }
2217
2218 snaplen = skb->len;
2219
2220 res = run_filter(skb, sk, snaplen);
2221 if (!res)
2222 goto drop_n_restore;
2223
2224 if (skb->ip_summed == CHECKSUM_PARTIAL)
2225 status |= TP_STATUS_CSUMNOTREADY;
2226 else if (skb->pkt_type != PACKET_OUTGOING &&
2227 (skb->ip_summed == CHECKSUM_COMPLETE ||
2228 skb_csum_unnecessary(skb)))
2229 status |= TP_STATUS_CSUM_VALID;
2230
2231 if (snaplen > res)
2232 snaplen = res;
2233
2234 if (sk->sk_type == SOCK_DGRAM) {
2235 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2236 po->tp_reserve;
2237 } else {
2238 unsigned int maclen = skb_network_offset(skb);
2239 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2240 (maclen < 16 ? 16 : maclen)) +
2241 po->tp_reserve;
2242 if (po->has_vnet_hdr) {
2243 netoff += sizeof(struct virtio_net_hdr);
2244 do_vnet = true;
2245 }
2246 macoff = netoff - maclen;
2247 }
2248 if (po->tp_version <= TPACKET_V2) {
2249 if (macoff + snaplen > po->rx_ring.frame_size) {
2250 if (po->copy_thresh &&
2251 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2252 if (skb_shared(skb)) {
2253 copy_skb = skb_clone(skb, GFP_ATOMIC);
2254 } else {
2255 copy_skb = skb_get(skb);
2256 skb_head = skb->data;
2257 }
2258 if (copy_skb)
2259 skb_set_owner_r(copy_skb, sk);
2260 }
2261 snaplen = po->rx_ring.frame_size - macoff;
2262 if ((int)snaplen < 0) {
2263 snaplen = 0;
2264 do_vnet = false;
2265 }
2266 }
2267 } else if (unlikely(macoff + snaplen >
2268 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2269 u32 nval;
2270
2271 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2272 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2273 snaplen, nval, macoff);
2274 snaplen = nval;
2275 if (unlikely((int)snaplen < 0)) {
2276 snaplen = 0;
2277 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2278 do_vnet = false;
2279 }
2280 }
2281 spin_lock(&sk->sk_receive_queue.lock);
2282 h.raw = packet_current_rx_frame(po, skb,
2283 TP_STATUS_KERNEL, (macoff+snaplen));
2284 if (!h.raw)
2285 goto drop_n_account;
2286 if (po->tp_version <= TPACKET_V2) {
2287 packet_increment_rx_head(po, &po->rx_ring);
2288 /*
2289 * LOSING will be reported till you read the stats,
2290 * because it's COR - Clear On Read.
2291 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2292 * at packet level.
2293 */
2294 if (po->stats.stats1.tp_drops)
2295 status |= TP_STATUS_LOSING;
2296 }
2297 po->stats.stats1.tp_packets++;
2298 if (copy_skb) {
2299 status |= TP_STATUS_COPY;
2300 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2301 }
2302 spin_unlock(&sk->sk_receive_queue.lock);
2303
2304 if (do_vnet) {
2305 if (virtio_net_hdr_from_skb(skb, h.raw + macoff -
2306 sizeof(struct virtio_net_hdr),
2307 vio_le(), true)) {
2308 spin_lock(&sk->sk_receive_queue.lock);
2309 goto drop_n_account;
2310 }
2311 }
2312
2313 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2314
2315 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2316 getnstimeofday(&ts);
2317
2318 status |= ts_status;
2319
2320 switch (po->tp_version) {
2321 case TPACKET_V1:
2322 h.h1->tp_len = skb->len;
2323 h.h1->tp_snaplen = snaplen;
2324 h.h1->tp_mac = macoff;
2325 h.h1->tp_net = netoff;
2326 h.h1->tp_sec = ts.tv_sec;
2327 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2328 hdrlen = sizeof(*h.h1);
2329 break;
2330 case TPACKET_V2:
2331 h.h2->tp_len = skb->len;
2332 h.h2->tp_snaplen = snaplen;
2333 h.h2->tp_mac = macoff;
2334 h.h2->tp_net = netoff;
2335 h.h2->tp_sec = ts.tv_sec;
2336 h.h2->tp_nsec = ts.tv_nsec;
2337 if (skb_vlan_tag_present(skb)) {
2338 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2339 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2340 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2341 } else {
2342 h.h2->tp_vlan_tci = 0;
2343 h.h2->tp_vlan_tpid = 0;
2344 }
2345 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2346 hdrlen = sizeof(*h.h2);
2347 break;
2348 case TPACKET_V3:
2349 /* tp_nxt_offset,vlan are already populated above.
2350 * So DONT clear those fields here
2351 */
2352 h.h3->tp_status |= status;
2353 h.h3->tp_len = skb->len;
2354 h.h3->tp_snaplen = snaplen;
2355 h.h3->tp_mac = macoff;
2356 h.h3->tp_net = netoff;
2357 h.h3->tp_sec = ts.tv_sec;
2358 h.h3->tp_nsec = ts.tv_nsec;
2359 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2360 hdrlen = sizeof(*h.h3);
2361 break;
2362 default:
2363 BUG();
2364 }
2365
2366 sll = h.raw + TPACKET_ALIGN(hdrlen);
2367 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2368 sll->sll_family = AF_PACKET;
2369 sll->sll_hatype = dev->type;
2370 sll->sll_protocol = skb->protocol;
2371 sll->sll_pkttype = skb->pkt_type;
2372 if (unlikely(po->origdev))
2373 sll->sll_ifindex = orig_dev->ifindex;
2374 else
2375 sll->sll_ifindex = dev->ifindex;
2376
2377 smp_mb();
2378
2379#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2380 if (po->tp_version <= TPACKET_V2) {
2381 u8 *start, *end;
2382
2383 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2384 macoff + snaplen);
2385
2386 for (start = h.raw; start < end; start += PAGE_SIZE)
2387 flush_dcache_page(pgv_to_page(start));
2388 }
2389 smp_wmb();
2390#endif
2391
2392 if (po->tp_version <= TPACKET_V2) {
2393 __packet_set_status(po, h.raw, status);
2394 sk->sk_data_ready(sk);
2395 } else {
2396 prb_clear_blk_fill_status(&po->rx_ring);
2397 }
2398
2399drop_n_restore:
2400 if (skb_head != skb->data && skb_shared(skb)) {
2401 skb->data = skb_head;
2402 skb->len = skb_len;
2403 }
2404drop:
2405 if (!is_drop_n_account)
2406 consume_skb(skb);
2407 else
2408 kfree_skb(skb);
2409 return 0;
2410
2411drop_n_account:
2412 is_drop_n_account = true;
2413 po->stats.stats1.tp_drops++;
2414 spin_unlock(&sk->sk_receive_queue.lock);
2415
2416 sk->sk_data_ready(sk);
2417 kfree_skb(copy_skb);
2418 goto drop_n_restore;
2419}
2420
2421static void tpacket_destruct_skb(struct sk_buff *skb)
2422{
2423 struct packet_sock *po = pkt_sk(skb->sk);
2424
2425 if (likely(po->tx_ring.pg_vec)) {
2426 void *ph;
2427 __u32 ts;
2428
2429 ph = skb_shinfo(skb)->destructor_arg;
2430 packet_dec_pending(&po->tx_ring);
2431
2432 ts = __packet_set_timestamp(po, ph, skb);
2433 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2434 }
2435
2436 sock_wfree(skb);
2437}
2438
2439static void tpacket_set_protocol(const struct net_device *dev,
2440 struct sk_buff *skb)
2441{
2442 if (dev->type == ARPHRD_ETHER) {
2443 skb_reset_mac_header(skb);
2444 skb->protocol = eth_hdr(skb)->h_proto;
2445 }
2446}
2447
2448static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2449{
2450 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2451 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2452 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2453 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2454 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2455 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2456 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2457
2458 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2459 return -EINVAL;
2460
2461 return 0;
2462}
2463
2464static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2465 struct virtio_net_hdr *vnet_hdr)
2466{
2467 if (*len < sizeof(*vnet_hdr))
2468 return -EINVAL;
2469 *len -= sizeof(*vnet_hdr);
2470
2471 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2472 return -EFAULT;
2473
2474 return __packet_snd_vnet_parse(vnet_hdr, *len);
2475}
2476
2477static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2478 void *frame, struct net_device *dev, void *data, int tp_len,
2479 __be16 proto, unsigned char *addr, int hlen, int copylen,
2480 const struct sockcm_cookie *sockc)
2481{
2482 union tpacket_uhdr ph;
2483 int to_write, offset, len, nr_frags, len_max;
2484 struct socket *sock = po->sk.sk_socket;
2485 struct page *page;
2486 int err;
2487
2488 ph.raw = frame;
2489
2490 skb->protocol = proto;
2491 skb->dev = dev;
2492 skb->priority = po->sk.sk_priority;
2493 skb->mark = po->sk.sk_mark;
2494 sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);
2495 skb_shinfo(skb)->destructor_arg = ph.raw;
2496
2497 skb_reserve(skb, hlen);
2498 skb_reset_network_header(skb);
2499
2500 to_write = tp_len;
2501
2502 if (sock->type == SOCK_DGRAM) {
2503 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2504 NULL, tp_len);
2505 if (unlikely(err < 0))
2506 return -EINVAL;
2507 } else if (copylen) {
2508 int hdrlen = min_t(int, copylen, tp_len);
2509
2510 skb_push(skb, dev->hard_header_len);
2511 skb_put(skb, copylen - dev->hard_header_len);
2512 err = skb_store_bits(skb, 0, data, hdrlen);
2513 if (unlikely(err))
2514 return err;
2515 if (!dev_validate_header(dev, skb->data, hdrlen))
2516 return -EINVAL;
2517 if (!skb->protocol)
2518 tpacket_set_protocol(dev, skb);
2519
2520 data += hdrlen;
2521 to_write -= hdrlen;
2522 }
2523
2524 offset = offset_in_page(data);
2525 len_max = PAGE_SIZE - offset;
2526 len = ((to_write > len_max) ? len_max : to_write);
2527
2528 skb->data_len = to_write;
2529 skb->len += to_write;
2530 skb->truesize += to_write;
2531 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2532
2533 while (likely(to_write)) {
2534 nr_frags = skb_shinfo(skb)->nr_frags;
2535
2536 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2537 pr_err("Packet exceed the number of skb frags(%lu)\n",
2538 MAX_SKB_FRAGS);
2539 return -EFAULT;
2540 }
2541
2542 page = pgv_to_page(data);
2543 data += len;
2544 flush_dcache_page(page);
2545 get_page(page);
2546 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2547 to_write -= len;
2548 offset = 0;
2549 len_max = PAGE_SIZE;
2550 len = ((to_write > len_max) ? len_max : to_write);
2551 }
2552
2553 skb_probe_transport_header(skb, 0);
2554
2555 return tp_len;
2556}
2557
2558static int tpacket_parse_header(struct packet_sock *po, void *frame,
2559 int size_max, void **data)
2560{
2561 union tpacket_uhdr ph;
2562 int tp_len, off;
2563
2564 ph.raw = frame;
2565
2566 switch (po->tp_version) {
2567 case TPACKET_V3:
2568 if (ph.h3->tp_next_offset != 0) {
2569 pr_warn_once("variable sized slot not supported");
2570 return -EINVAL;
2571 }
2572 tp_len = ph.h3->tp_len;
2573 break;
2574 case TPACKET_V2:
2575 tp_len = ph.h2->tp_len;
2576 break;
2577 default:
2578 tp_len = ph.h1->tp_len;
2579 break;
2580 }
2581 if (unlikely(tp_len > size_max)) {
2582 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2583 return -EMSGSIZE;
2584 }
2585
2586 if (unlikely(po->tp_tx_has_off)) {
2587 int off_min, off_max;
2588
2589 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2590 off_max = po->tx_ring.frame_size - tp_len;
2591 if (po->sk.sk_type == SOCK_DGRAM) {
2592 switch (po->tp_version) {
2593 case TPACKET_V3:
2594 off = ph.h3->tp_net;
2595 break;
2596 case TPACKET_V2:
2597 off = ph.h2->tp_net;
2598 break;
2599 default:
2600 off = ph.h1->tp_net;
2601 break;
2602 }
2603 } else {
2604 switch (po->tp_version) {
2605 case TPACKET_V3:
2606 off = ph.h3->tp_mac;
2607 break;
2608 case TPACKET_V2:
2609 off = ph.h2->tp_mac;
2610 break;
2611 default:
2612 off = ph.h1->tp_mac;
2613 break;
2614 }
2615 }
2616 if (unlikely((off < off_min) || (off_max < off)))
2617 return -EINVAL;
2618 } else {
2619 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2620 }
2621
2622 *data = frame + off;
2623 return tp_len;
2624}
2625
2626static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2627{
2628 struct sk_buff *skb;
2629 struct net_device *dev;
2630 struct virtio_net_hdr *vnet_hdr = NULL;
2631 struct sockcm_cookie sockc;
2632 __be16 proto;
2633 int err, reserve = 0;
2634 void *ph;
2635 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2636 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2637 int tp_len, size_max;
2638 unsigned char *addr;
2639 void *data;
2640 int len_sum = 0;
2641 int status = TP_STATUS_AVAILABLE;
2642 int hlen, tlen, copylen = 0;
2643
2644 mutex_lock(&po->pg_vec_lock);
2645
2646 if (likely(saddr == NULL)) {
2647 dev = packet_cached_dev_get(po);
2648 proto = po->num;
2649 addr = NULL;
2650 } else {
2651 err = -EINVAL;
2652 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2653 goto out;
2654 if (msg->msg_namelen < (saddr->sll_halen
2655 + offsetof(struct sockaddr_ll,
2656 sll_addr)))
2657 goto out;
2658 proto = saddr->sll_protocol;
2659 addr = saddr->sll_addr;
2660 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2661 }
2662
2663 err = -ENXIO;
2664 if (unlikely(dev == NULL))
2665 goto out;
2666 err = -ENETDOWN;
2667 if (unlikely(!(dev->flags & IFF_UP)))
2668 goto out_put;
2669
2670 sockc.tsflags = po->sk.sk_tsflags;
2671 if (msg->msg_controllen) {
2672 err = sock_cmsg_send(&po->sk, msg, &sockc);
2673 if (unlikely(err))
2674 goto out_put;
2675 }
2676
2677 if (po->sk.sk_socket->type == SOCK_RAW)
2678 reserve = dev->hard_header_len;
2679 size_max = po->tx_ring.frame_size
2680 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2681
2682 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2683 size_max = dev->mtu + reserve + VLAN_HLEN;
2684
2685 do {
2686 ph = packet_current_frame(po, &po->tx_ring,
2687 TP_STATUS_SEND_REQUEST);
2688 if (unlikely(ph == NULL)) {
2689 if (need_wait && need_resched())
2690 schedule();
2691 continue;
2692 }
2693
2694 skb = NULL;
2695 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2696 if (tp_len < 0)
2697 goto tpacket_error;
2698
2699 status = TP_STATUS_SEND_REQUEST;
2700 hlen = LL_RESERVED_SPACE(dev);
2701 tlen = dev->needed_tailroom;
2702 if (po->has_vnet_hdr) {
2703 vnet_hdr = data;
2704 data += sizeof(*vnet_hdr);
2705 tp_len -= sizeof(*vnet_hdr);
2706 if (tp_len < 0 ||
2707 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2708 tp_len = -EINVAL;
2709 goto tpacket_error;
2710 }
2711 copylen = __virtio16_to_cpu(vio_le(),
2712 vnet_hdr->hdr_len);
2713 }
2714 copylen = max_t(int, copylen, dev->hard_header_len);
2715 skb = sock_alloc_send_skb(&po->sk,
2716 hlen + tlen + sizeof(struct sockaddr_ll) +
2717 (copylen - dev->hard_header_len),
2718 !need_wait, &err);
2719
2720 if (unlikely(skb == NULL)) {
2721 /* we assume the socket was initially writeable ... */
2722 if (likely(len_sum > 0))
2723 err = len_sum;
2724 goto out_status;
2725 }
2726 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2727 addr, hlen, copylen, &sockc);
2728 if (likely(tp_len >= 0) &&
2729 tp_len > dev->mtu + reserve &&
2730 !po->has_vnet_hdr &&
2731 !packet_extra_vlan_len_allowed(dev, skb))
2732 tp_len = -EMSGSIZE;
2733
2734 if (unlikely(tp_len < 0)) {
2735tpacket_error:
2736 if (po->tp_loss) {
2737 __packet_set_status(po, ph,
2738 TP_STATUS_AVAILABLE);
2739 packet_increment_head(&po->tx_ring);
2740 kfree_skb(skb);
2741 continue;
2742 } else {
2743 status = TP_STATUS_WRONG_FORMAT;
2744 err = tp_len;
2745 goto out_status;
2746 }
2747 }
2748
2749 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr,
2750 vio_le())) {
2751 tp_len = -EINVAL;
2752 goto tpacket_error;
2753 }
2754
2755 skb->destructor = tpacket_destruct_skb;
2756 __packet_set_status(po, ph, TP_STATUS_SENDING);
2757 packet_inc_pending(&po->tx_ring);
2758
2759 status = TP_STATUS_SEND_REQUEST;
2760 err = po->xmit(skb);
2761 if (unlikely(err > 0)) {
2762 err = net_xmit_errno(err);
2763 if (err && __packet_get_status(po, ph) ==
2764 TP_STATUS_AVAILABLE) {
2765 /* skb was destructed already */
2766 skb = NULL;
2767 goto out_status;
2768 }
2769 /*
2770 * skb was dropped but not destructed yet;
2771 * let's treat it like congestion or err < 0
2772 */
2773 err = 0;
2774 }
2775 packet_increment_head(&po->tx_ring);
2776 len_sum += tp_len;
2777 } while (likely((ph != NULL) ||
2778 /* Note: packet_read_pending() might be slow if we have
2779 * to call it as it's per_cpu variable, but in fast-path
2780 * we already short-circuit the loop with the first
2781 * condition, and luckily don't have to go that path
2782 * anyway.
2783 */
2784 (need_wait && packet_read_pending(&po->tx_ring))));
2785
2786 err = len_sum;
2787 goto out_put;
2788
2789out_status:
2790 __packet_set_status(po, ph, status);
2791 kfree_skb(skb);
2792out_put:
2793 dev_put(dev);
2794out:
2795 mutex_unlock(&po->pg_vec_lock);
2796 return err;
2797}
2798
2799static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2800 size_t reserve, size_t len,
2801 size_t linear, int noblock,
2802 int *err)
2803{
2804 struct sk_buff *skb;
2805
2806 /* Under a page? Don't bother with paged skb. */
2807 if (prepad + len < PAGE_SIZE || !linear)
2808 linear = len;
2809
2810 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2811 err, 0);
2812 if (!skb)
2813 return NULL;
2814
2815 skb_reserve(skb, reserve);
2816 skb_put(skb, linear);
2817 skb->data_len = len - linear;
2818 skb->len += len - linear;
2819
2820 return skb;
2821}
2822
2823static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2824{
2825 struct sock *sk = sock->sk;
2826 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2827 struct sk_buff *skb;
2828 struct net_device *dev;
2829 __be16 proto;
2830 unsigned char *addr;
2831 int err, reserve = 0;
2832 struct sockcm_cookie sockc;
2833 struct virtio_net_hdr vnet_hdr = { 0 };
2834 int offset = 0;
2835 struct packet_sock *po = pkt_sk(sk);
2836 bool has_vnet_hdr = false;
2837 int hlen, tlen, linear;
2838 int extra_len = 0;
2839
2840 /*
2841 * Get and verify the address.
2842 */
2843
2844 if (likely(saddr == NULL)) {
2845 dev = packet_cached_dev_get(po);
2846 proto = po->num;
2847 addr = NULL;
2848 } else {
2849 err = -EINVAL;
2850 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2851 goto out;
2852 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2853 goto out;
2854 proto = saddr->sll_protocol;
2855 addr = saddr->sll_addr;
2856 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2857 }
2858
2859 err = -ENXIO;
2860 if (unlikely(dev == NULL))
2861 goto out_unlock;
2862 err = -ENETDOWN;
2863 if (unlikely(!(dev->flags & IFF_UP)))
2864 goto out_unlock;
2865
2866 sockc.tsflags = sk->sk_tsflags;
2867 sockc.mark = sk->sk_mark;
2868 if (msg->msg_controllen) {
2869 err = sock_cmsg_send(sk, msg, &sockc);
2870 if (unlikely(err))
2871 goto out_unlock;
2872 }
2873
2874 if (sock->type == SOCK_RAW)
2875 reserve = dev->hard_header_len;
2876 if (po->has_vnet_hdr) {
2877 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2878 if (err)
2879 goto out_unlock;
2880 has_vnet_hdr = true;
2881 }
2882
2883 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2884 if (!netif_supports_nofcs(dev)) {
2885 err = -EPROTONOSUPPORT;
2886 goto out_unlock;
2887 }
2888 extra_len = 4; /* We're doing our own CRC */
2889 }
2890
2891 err = -EMSGSIZE;
2892 if (!vnet_hdr.gso_type &&
2893 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2894 goto out_unlock;
2895
2896 err = -ENOBUFS;
2897 hlen = LL_RESERVED_SPACE(dev);
2898 tlen = dev->needed_tailroom;
2899 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2900 linear = max(linear, min_t(int, len, dev->hard_header_len));
2901 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2902 msg->msg_flags & MSG_DONTWAIT, &err);
2903 if (skb == NULL)
2904 goto out_unlock;
2905
2906 skb_reset_network_header(skb);
2907
2908 err = -EINVAL;
2909 if (sock->type == SOCK_DGRAM) {
2910 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2911 if (unlikely(offset < 0))
2912 goto out_free;
2913 } else if (reserve) {
2914 skb_reserve(skb, -reserve);
2915 }
2916
2917 /* Returns -EFAULT on error */
2918 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2919 if (err)
2920 goto out_free;
2921
2922 if (sock->type == SOCK_RAW &&
2923 !dev_validate_header(dev, skb->data, len)) {
2924 err = -EINVAL;
2925 goto out_free;
2926 }
2927
2928 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
2929
2930 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2931 !packet_extra_vlan_len_allowed(dev, skb)) {
2932 err = -EMSGSIZE;
2933 goto out_free;
2934 }
2935
2936 skb->protocol = proto;
2937 skb->dev = dev;
2938 skb->priority = sk->sk_priority;
2939 skb->mark = sockc.mark;
2940
2941 if (has_vnet_hdr) {
2942 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2943 if (err)
2944 goto out_free;
2945 len += sizeof(vnet_hdr);
2946 }
2947
2948 skb_probe_transport_header(skb, reserve);
2949
2950 if (unlikely(extra_len == 4))
2951 skb->no_fcs = 1;
2952
2953 err = po->xmit(skb);
2954 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2955 goto out_unlock;
2956
2957 dev_put(dev);
2958
2959 return len;
2960
2961out_free:
2962 kfree_skb(skb);
2963out_unlock:
2964 if (dev)
2965 dev_put(dev);
2966out:
2967 return err;
2968}
2969
2970static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2971{
2972 struct sock *sk = sock->sk;
2973 struct packet_sock *po = pkt_sk(sk);
2974
2975 if (po->tx_ring.pg_vec)
2976 return tpacket_snd(po, msg);
2977 else
2978 return packet_snd(sock, msg, len);
2979}
2980
2981/*
2982 * Close a PACKET socket. This is fairly simple. We immediately go
2983 * to 'closed' state and remove our protocol entry in the device list.
2984 */
2985
2986static int packet_release(struct socket *sock)
2987{
2988 struct sock *sk = sock->sk;
2989 struct packet_sock *po;
2990 struct packet_fanout *f;
2991 struct net *net;
2992 union tpacket_req_u req_u;
2993
2994 if (!sk)
2995 return 0;
2996
2997 net = sock_net(sk);
2998 po = pkt_sk(sk);
2999
3000 mutex_lock(&net->packet.sklist_lock);
3001 sk_del_node_init_rcu(sk);
3002 mutex_unlock(&net->packet.sklist_lock);
3003
3004 preempt_disable();
3005 sock_prot_inuse_add(net, sk->sk_prot, -1);
3006 preempt_enable();
3007
3008 spin_lock(&po->bind_lock);
3009 unregister_prot_hook(sk, false);
3010 packet_cached_dev_reset(po);
3011
3012 if (po->prot_hook.dev) {
3013 dev_put(po->prot_hook.dev);
3014 po->prot_hook.dev = NULL;
3015 }
3016 spin_unlock(&po->bind_lock);
3017
3018 packet_flush_mclist(sk);
3019
3020 lock_sock(sk);
3021 if (po->rx_ring.pg_vec) {
3022 memset(&req_u, 0, sizeof(req_u));
3023 packet_set_ring(sk, &req_u, 1, 0);
3024 }
3025
3026 if (po->tx_ring.pg_vec) {
3027 memset(&req_u, 0, sizeof(req_u));
3028 packet_set_ring(sk, &req_u, 1, 1);
3029 }
3030 release_sock(sk);
3031
3032 f = fanout_release(sk);
3033
3034 synchronize_net();
3035
3036 if (f) {
3037 kfree(po->rollover);
3038 fanout_release_data(f);
3039 kfree(f);
3040 }
3041 /*
3042 * Now the socket is dead. No more input will appear.
3043 */
3044 sock_orphan(sk);
3045 sock->sk = NULL;
3046
3047 /* Purge queues */
3048
3049 skb_queue_purge(&sk->sk_receive_queue);
3050 packet_free_pending(po);
3051 sk_refcnt_debug_release(sk);
3052
3053 sock_put(sk);
3054 return 0;
3055}
3056
3057/*
3058 * Attach a packet hook.
3059 */
3060
3061static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3062 __be16 proto)
3063{
3064 struct packet_sock *po = pkt_sk(sk);
3065 struct net_device *dev_curr;
3066 __be16 proto_curr;
3067 bool need_rehook;
3068 struct net_device *dev = NULL;
3069 int ret = 0;
3070 bool unlisted = false;
3071
3072 lock_sock(sk);
3073 spin_lock(&po->bind_lock);
3074 rcu_read_lock();
3075
3076 if (po->fanout) {
3077 ret = -EINVAL;
3078 goto out_unlock;
3079 }
3080
3081 if (name) {
3082 dev = dev_get_by_name_rcu(sock_net(sk), name);
3083 if (!dev) {
3084 ret = -ENODEV;
3085 goto out_unlock;
3086 }
3087 } else if (ifindex) {
3088 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3089 if (!dev) {
3090 ret = -ENODEV;
3091 goto out_unlock;
3092 }
3093 }
3094
3095 if (dev)
3096 dev_hold(dev);
3097
3098 proto_curr = po->prot_hook.type;
3099 dev_curr = po->prot_hook.dev;
3100
3101 need_rehook = proto_curr != proto || dev_curr != dev;
3102
3103 if (need_rehook) {
3104 if (po->running) {
3105 rcu_read_unlock();
3106 /* prevents packet_notifier() from calling
3107 * register_prot_hook()
3108 */
3109 po->num = 0;
3110 __unregister_prot_hook(sk, true);
3111 rcu_read_lock();
3112 dev_curr = po->prot_hook.dev;
3113 if (dev)
3114 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3115 dev->ifindex);
3116 }
3117
3118 BUG_ON(po->running);
3119 po->num = proto;
3120 po->prot_hook.type = proto;
3121
3122 if (unlikely(unlisted)) {
3123 dev_put(dev);
3124 po->prot_hook.dev = NULL;
3125 po->ifindex = -1;
3126 packet_cached_dev_reset(po);
3127 } else {
3128 po->prot_hook.dev = dev;
3129 po->ifindex = dev ? dev->ifindex : 0;
3130 packet_cached_dev_assign(po, dev);
3131 }
3132 }
3133 if (dev_curr)
3134 dev_put(dev_curr);
3135
3136 if (proto == 0 || !need_rehook)
3137 goto out_unlock;
3138
3139 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3140 register_prot_hook(sk);
3141 } else {
3142 sk->sk_err = ENETDOWN;
3143 if (!sock_flag(sk, SOCK_DEAD))
3144 sk->sk_error_report(sk);
3145 }
3146
3147out_unlock:
3148 rcu_read_unlock();
3149 spin_unlock(&po->bind_lock);
3150 release_sock(sk);
3151 return ret;
3152}
3153
3154/*
3155 * Bind a packet socket to a device
3156 */
3157
3158static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3159 int addr_len)
3160{
3161 struct sock *sk = sock->sk;
3162 char name[sizeof(uaddr->sa_data) + 1];
3163
3164 /*
3165 * Check legality
3166 */
3167
3168 if (addr_len != sizeof(struct sockaddr))
3169 return -EINVAL;
3170 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3171 * zero-terminated.
3172 */
3173 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3174 name[sizeof(uaddr->sa_data)] = 0;
3175
3176 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3177}
3178
3179static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3180{
3181 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3182 struct sock *sk = sock->sk;
3183
3184 /*
3185 * Check legality
3186 */
3187
3188 if (addr_len < sizeof(struct sockaddr_ll))
3189 return -EINVAL;
3190 if (sll->sll_family != AF_PACKET)
3191 return -EINVAL;
3192
3193 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3194 sll->sll_protocol ? : pkt_sk(sk)->num);
3195}
3196
3197static struct proto packet_proto = {
3198 .name = "PACKET",
3199 .owner = THIS_MODULE,
3200 .obj_size = sizeof(struct packet_sock),
3201};
3202
3203/*
3204 * Create a packet of type SOCK_PACKET.
3205 */
3206
3207static int packet_create(struct net *net, struct socket *sock, int protocol,
3208 int kern)
3209{
3210 struct sock *sk;
3211 struct packet_sock *po;
3212 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3213 int err;
3214
3215 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3216 return -EPERM;
3217 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3218 sock->type != SOCK_PACKET)
3219 return -ESOCKTNOSUPPORT;
3220
3221 sock->state = SS_UNCONNECTED;
3222
3223 err = -ENOBUFS;
3224 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3225 if (sk == NULL)
3226 goto out;
3227
3228 sock->ops = &packet_ops;
3229 if (sock->type == SOCK_PACKET)
3230 sock->ops = &packet_ops_spkt;
3231
3232 sock_init_data(sock, sk);
3233
3234 po = pkt_sk(sk);
3235 sk->sk_family = PF_PACKET;
3236 po->num = proto;
3237 po->xmit = dev_queue_xmit;
3238
3239 err = packet_alloc_pending(po);
3240 if (err)
3241 goto out2;
3242
3243 packet_cached_dev_reset(po);
3244
3245 sk->sk_destruct = packet_sock_destruct;
3246 sk_refcnt_debug_inc(sk);
3247
3248 /*
3249 * Attach a protocol block
3250 */
3251
3252 spin_lock_init(&po->bind_lock);
3253 mutex_init(&po->pg_vec_lock);
3254 po->rollover = NULL;
3255 po->prot_hook.func = packet_rcv;
3256
3257 if (sock->type == SOCK_PACKET)
3258 po->prot_hook.func = packet_rcv_spkt;
3259
3260 po->prot_hook.af_packet_priv = sk;
3261
3262 if (proto) {
3263 po->prot_hook.type = proto;
3264 __register_prot_hook(sk);
3265 }
3266
3267 mutex_lock(&net->packet.sklist_lock);
3268 sk_add_node_rcu(sk, &net->packet.sklist);
3269 mutex_unlock(&net->packet.sklist_lock);
3270
3271 preempt_disable();
3272 sock_prot_inuse_add(net, &packet_proto, 1);
3273 preempt_enable();
3274
3275 return 0;
3276out2:
3277 sk_free(sk);
3278out:
3279 return err;
3280}
3281
3282/*
3283 * Pull a packet from our receive queue and hand it to the user.
3284 * If necessary we block.
3285 */
3286
3287static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3288 int flags)
3289{
3290 struct sock *sk = sock->sk;
3291 struct sk_buff *skb;
3292 int copied, err;
3293 int vnet_hdr_len = 0;
3294 unsigned int origlen = 0;
3295
3296 err = -EINVAL;
3297 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3298 goto out;
3299
3300#if 0
3301 /* What error should we return now? EUNATTACH? */
3302 if (pkt_sk(sk)->ifindex < 0)
3303 return -ENODEV;
3304#endif
3305
3306 if (flags & MSG_ERRQUEUE) {
3307 err = sock_recv_errqueue(sk, msg, len,
3308 SOL_PACKET, PACKET_TX_TIMESTAMP);
3309 goto out;
3310 }
3311
3312 /*
3313 * Call the generic datagram receiver. This handles all sorts
3314 * of horrible races and re-entrancy so we can forget about it
3315 * in the protocol layers.
3316 *
3317 * Now it will return ENETDOWN, if device have just gone down,
3318 * but then it will block.
3319 */
3320
3321 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3322
3323 /*
3324 * An error occurred so return it. Because skb_recv_datagram()
3325 * handles the blocking we don't see and worry about blocking
3326 * retries.
3327 */
3328
3329 if (skb == NULL)
3330 goto out;
3331
3332 if (pkt_sk(sk)->pressure)
3333 packet_rcv_has_room(pkt_sk(sk), NULL);
3334
3335 if (pkt_sk(sk)->has_vnet_hdr) {
3336 err = packet_rcv_vnet(msg, skb, &len);
3337 if (err)
3338 goto out_free;
3339 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3340 }
3341
3342 /* You lose any data beyond the buffer you gave. If it worries
3343 * a user program they can ask the device for its MTU
3344 * anyway.
3345 */
3346 copied = skb->len;
3347 if (copied > len) {
3348 copied = len;
3349 msg->msg_flags |= MSG_TRUNC;
3350 }
3351
3352 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3353 if (err)
3354 goto out_free;
3355
3356 if (sock->type != SOCK_PACKET) {
3357 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3358
3359 /* Original length was stored in sockaddr_ll fields */
3360 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3361 sll->sll_family = AF_PACKET;
3362 sll->sll_protocol = skb->protocol;
3363 }
3364
3365 sock_recv_ts_and_drops(msg, sk, skb);
3366
3367 if (msg->msg_name) {
3368 /* If the address length field is there to be filled
3369 * in, we fill it in now.
3370 */
3371 if (sock->type == SOCK_PACKET) {
3372 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3373 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3374 } else {
3375 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3376
3377 msg->msg_namelen = sll->sll_halen +
3378 offsetof(struct sockaddr_ll, sll_addr);
3379 }
3380 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3381 msg->msg_namelen);
3382 }
3383
3384 if (pkt_sk(sk)->auxdata) {
3385 struct tpacket_auxdata aux;
3386
3387 aux.tp_status = TP_STATUS_USER;
3388 if (skb->ip_summed == CHECKSUM_PARTIAL)
3389 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3390 else if (skb->pkt_type != PACKET_OUTGOING &&
3391 (skb->ip_summed == CHECKSUM_COMPLETE ||
3392 skb_csum_unnecessary(skb)))
3393 aux.tp_status |= TP_STATUS_CSUM_VALID;
3394
3395 aux.tp_len = origlen;
3396 aux.tp_snaplen = skb->len;
3397 aux.tp_mac = 0;
3398 aux.tp_net = skb_network_offset(skb);
3399 if (skb_vlan_tag_present(skb)) {
3400 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3401 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3402 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3403 } else {
3404 aux.tp_vlan_tci = 0;
3405 aux.tp_vlan_tpid = 0;
3406 }
3407 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3408 }
3409
3410 /*
3411 * Free or return the buffer as appropriate. Again this
3412 * hides all the races and re-entrancy issues from us.
3413 */
3414 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3415
3416out_free:
3417 skb_free_datagram(sk, skb);
3418out:
3419 return err;
3420}
3421
3422static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3423 int peer)
3424{
3425 struct net_device *dev;
3426 struct sock *sk = sock->sk;
3427
3428 if (peer)
3429 return -EOPNOTSUPP;
3430
3431 uaddr->sa_family = AF_PACKET;
3432 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3433 rcu_read_lock();
3434 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3435 if (dev)
3436 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3437 rcu_read_unlock();
3438
3439 return sizeof(*uaddr);
3440}
3441
3442static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3443 int peer)
3444{
3445 struct net_device *dev;
3446 struct sock *sk = sock->sk;
3447 struct packet_sock *po = pkt_sk(sk);
3448 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3449
3450 if (peer)
3451 return -EOPNOTSUPP;
3452
3453 sll->sll_family = AF_PACKET;
3454 sll->sll_ifindex = po->ifindex;
3455 sll->sll_protocol = po->num;
3456 sll->sll_pkttype = 0;
3457 rcu_read_lock();
3458 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3459 if (dev) {
3460 sll->sll_hatype = dev->type;
3461 sll->sll_halen = dev->addr_len;
3462 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3463 } else {
3464 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3465 sll->sll_halen = 0;
3466 }
3467 rcu_read_unlock();
3468
3469 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3470}
3471
3472static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3473 int what)
3474{
3475 switch (i->type) {
3476 case PACKET_MR_MULTICAST:
3477 if (i->alen != dev->addr_len)
3478 return -EINVAL;
3479 if (what > 0)
3480 return dev_mc_add(dev, i->addr);
3481 else
3482 return dev_mc_del(dev, i->addr);
3483 break;
3484 case PACKET_MR_PROMISC:
3485 return dev_set_promiscuity(dev, what);
3486 case PACKET_MR_ALLMULTI:
3487 return dev_set_allmulti(dev, what);
3488 case PACKET_MR_UNICAST:
3489 if (i->alen != dev->addr_len)
3490 return -EINVAL;
3491 if (what > 0)
3492 return dev_uc_add(dev, i->addr);
3493 else
3494 return dev_uc_del(dev, i->addr);
3495 break;
3496 default:
3497 break;
3498 }
3499 return 0;
3500}
3501
3502static void packet_dev_mclist_delete(struct net_device *dev,
3503 struct packet_mclist **mlp)
3504{
3505 struct packet_mclist *ml;
3506
3507 while ((ml = *mlp) != NULL) {
3508 if (ml->ifindex == dev->ifindex) {
3509 packet_dev_mc(dev, ml, -1);
3510 *mlp = ml->next;
3511 kfree(ml);
3512 } else
3513 mlp = &ml->next;
3514 }
3515}
3516
3517static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3518{
3519 struct packet_sock *po = pkt_sk(sk);
3520 struct packet_mclist *ml, *i;
3521 struct net_device *dev;
3522 int err;
3523
3524 rtnl_lock();
3525
3526 err = -ENODEV;
3527 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3528 if (!dev)
3529 goto done;
3530
3531 err = -EINVAL;
3532 if (mreq->mr_alen > dev->addr_len)
3533 goto done;
3534
3535 err = -ENOBUFS;
3536 i = kmalloc(sizeof(*i), GFP_KERNEL);
3537 if (i == NULL)
3538 goto done;
3539
3540 err = 0;
3541 for (ml = po->mclist; ml; ml = ml->next) {
3542 if (ml->ifindex == mreq->mr_ifindex &&
3543 ml->type == mreq->mr_type &&
3544 ml->alen == mreq->mr_alen &&
3545 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3546 ml->count++;
3547 /* Free the new element ... */
3548 kfree(i);
3549 goto done;
3550 }
3551 }
3552
3553 i->type = mreq->mr_type;
3554 i->ifindex = mreq->mr_ifindex;
3555 i->alen = mreq->mr_alen;
3556 memcpy(i->addr, mreq->mr_address, i->alen);
3557 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3558 i->count = 1;
3559 i->next = po->mclist;
3560 po->mclist = i;
3561 err = packet_dev_mc(dev, i, 1);
3562 if (err) {
3563 po->mclist = i->next;
3564 kfree(i);
3565 }
3566
3567done:
3568 rtnl_unlock();
3569 return err;
3570}
3571
3572static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3573{
3574 struct packet_mclist *ml, **mlp;
3575
3576 rtnl_lock();
3577
3578 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3579 if (ml->ifindex == mreq->mr_ifindex &&
3580 ml->type == mreq->mr_type &&
3581 ml->alen == mreq->mr_alen &&
3582 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3583 if (--ml->count == 0) {
3584 struct net_device *dev;
3585 *mlp = ml->next;
3586 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3587 if (dev)
3588 packet_dev_mc(dev, ml, -1);
3589 kfree(ml);
3590 }
3591 break;
3592 }
3593 }
3594 rtnl_unlock();
3595 return 0;
3596}
3597
3598static void packet_flush_mclist(struct sock *sk)
3599{
3600 struct packet_sock *po = pkt_sk(sk);
3601 struct packet_mclist *ml;
3602
3603 if (!po->mclist)
3604 return;
3605
3606 rtnl_lock();
3607 while ((ml = po->mclist) != NULL) {
3608 struct net_device *dev;
3609
3610 po->mclist = ml->next;
3611 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3612 if (dev != NULL)
3613 packet_dev_mc(dev, ml, -1);
3614 kfree(ml);
3615 }
3616 rtnl_unlock();
3617}
3618
3619static int
3620packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3621{
3622 struct sock *sk = sock->sk;
3623 struct packet_sock *po = pkt_sk(sk);
3624 int ret;
3625
3626 if (level != SOL_PACKET)
3627 return -ENOPROTOOPT;
3628
3629 switch (optname) {
3630 case PACKET_ADD_MEMBERSHIP:
3631 case PACKET_DROP_MEMBERSHIP:
3632 {
3633 struct packet_mreq_max mreq;
3634 int len = optlen;
3635 memset(&mreq, 0, sizeof(mreq));
3636 if (len < sizeof(struct packet_mreq))
3637 return -EINVAL;
3638 if (len > sizeof(mreq))
3639 len = sizeof(mreq);
3640 if (copy_from_user(&mreq, optval, len))
3641 return -EFAULT;
3642 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3643 return -EINVAL;
3644 if (optname == PACKET_ADD_MEMBERSHIP)
3645 ret = packet_mc_add(sk, &mreq);
3646 else
3647 ret = packet_mc_drop(sk, &mreq);
3648 return ret;
3649 }
3650
3651 case PACKET_RX_RING:
3652 case PACKET_TX_RING:
3653 {
3654 union tpacket_req_u req_u;
3655 int len;
3656
3657 lock_sock(sk);
3658 switch (po->tp_version) {
3659 case TPACKET_V1:
3660 case TPACKET_V2:
3661 len = sizeof(req_u.req);
3662 break;
3663 case TPACKET_V3:
3664 default:
3665 len = sizeof(req_u.req3);
3666 break;
3667 }
3668 if (optlen < len) {
3669 ret = -EINVAL;
3670 } else {
3671 if (copy_from_user(&req_u.req, optval, len))
3672 ret = -EFAULT;
3673 else
3674 ret = packet_set_ring(sk, &req_u, 0,
3675 optname == PACKET_TX_RING);
3676 }
3677 release_sock(sk);
3678 return ret;
3679 }
3680 case PACKET_COPY_THRESH:
3681 {
3682 int val;
3683
3684 if (optlen != sizeof(val))
3685 return -EINVAL;
3686 if (copy_from_user(&val, optval, sizeof(val)))
3687 return -EFAULT;
3688
3689 pkt_sk(sk)->copy_thresh = val;
3690 return 0;
3691 }
3692 case PACKET_VERSION:
3693 {
3694 int val;
3695
3696 if (optlen != sizeof(val))
3697 return -EINVAL;
3698 if (copy_from_user(&val, optval, sizeof(val)))
3699 return -EFAULT;
3700 switch (val) {
3701 case TPACKET_V1:
3702 case TPACKET_V2:
3703 case TPACKET_V3:
3704 break;
3705 default:
3706 return -EINVAL;
3707 }
3708 lock_sock(sk);
3709 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3710 ret = -EBUSY;
3711 } else {
3712 po->tp_version = val;
3713 ret = 0;
3714 }
3715 release_sock(sk);
3716 return ret;
3717 }
3718 case PACKET_RESERVE:
3719 {
3720 unsigned int val;
3721
3722 if (optlen != sizeof(val))
3723 return -EINVAL;
3724 if (copy_from_user(&val, optval, sizeof(val)))
3725 return -EFAULT;
3726 if (val > INT_MAX)
3727 return -EINVAL;
3728 lock_sock(sk);
3729 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3730 ret = -EBUSY;
3731 } else {
3732 po->tp_reserve = val;
3733 ret = 0;
3734 }
3735 release_sock(sk);
3736 return ret;
3737 }
3738 case PACKET_LOSS:
3739 {
3740 unsigned int val;
3741
3742 if (optlen != sizeof(val))
3743 return -EINVAL;
3744 if (copy_from_user(&val, optval, sizeof(val)))
3745 return -EFAULT;
3746
3747 lock_sock(sk);
3748 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3749 ret = -EBUSY;
3750 } else {
3751 po->tp_loss = !!val;
3752 ret = 0;
3753 }
3754 release_sock(sk);
3755 return ret;
3756 }
3757 case PACKET_AUXDATA:
3758 {
3759 int val;
3760
3761 if (optlen < sizeof(val))
3762 return -EINVAL;
3763 if (copy_from_user(&val, optval, sizeof(val)))
3764 return -EFAULT;
3765
3766 lock_sock(sk);
3767 po->auxdata = !!val;
3768 release_sock(sk);
3769 return 0;
3770 }
3771 case PACKET_ORIGDEV:
3772 {
3773 int val;
3774
3775 if (optlen < sizeof(val))
3776 return -EINVAL;
3777 if (copy_from_user(&val, optval, sizeof(val)))
3778 return -EFAULT;
3779
3780 lock_sock(sk);
3781 po->origdev = !!val;
3782 release_sock(sk);
3783 return 0;
3784 }
3785 case PACKET_VNET_HDR:
3786 {
3787 int val;
3788
3789 if (sock->type != SOCK_RAW)
3790 return -EINVAL;
3791 if (optlen < sizeof(val))
3792 return -EINVAL;
3793 if (copy_from_user(&val, optval, sizeof(val)))
3794 return -EFAULT;
3795
3796 lock_sock(sk);
3797 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3798 ret = -EBUSY;
3799 } else {
3800 po->has_vnet_hdr = !!val;
3801 ret = 0;
3802 }
3803 release_sock(sk);
3804 return ret;
3805 }
3806 case PACKET_TIMESTAMP:
3807 {
3808 int val;
3809
3810 if (optlen != sizeof(val))
3811 return -EINVAL;
3812 if (copy_from_user(&val, optval, sizeof(val)))
3813 return -EFAULT;
3814
3815 po->tp_tstamp = val;
3816 return 0;
3817 }
3818 case PACKET_FANOUT:
3819 {
3820 int val;
3821
3822 if (optlen != sizeof(val))
3823 return -EINVAL;
3824 if (copy_from_user(&val, optval, sizeof(val)))
3825 return -EFAULT;
3826
3827 return fanout_add(sk, val & 0xffff, val >> 16);
3828 }
3829 case PACKET_FANOUT_DATA:
3830 {
3831 if (!po->fanout)
3832 return -EINVAL;
3833
3834 return fanout_set_data(po, optval, optlen);
3835 }
3836 case PACKET_TX_HAS_OFF:
3837 {
3838 unsigned int val;
3839
3840 if (optlen != sizeof(val))
3841 return -EINVAL;
3842 if (copy_from_user(&val, optval, sizeof(val)))
3843 return -EFAULT;
3844
3845 lock_sock(sk);
3846 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3847 ret = -EBUSY;
3848 } else {
3849 po->tp_tx_has_off = !!val;
3850 ret = 0;
3851 }
3852 release_sock(sk);
3853 return 0;
3854 }
3855 case PACKET_QDISC_BYPASS:
3856 {
3857 int val;
3858
3859 if (optlen != sizeof(val))
3860 return -EINVAL;
3861 if (copy_from_user(&val, optval, sizeof(val)))
3862 return -EFAULT;
3863
3864 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3865 return 0;
3866 }
3867 default:
3868 return -ENOPROTOOPT;
3869 }
3870}
3871
3872static int packet_getsockopt(struct socket *sock, int level, int optname,
3873 char __user *optval, int __user *optlen)
3874{
3875 int len;
3876 int val, lv = sizeof(val);
3877 struct sock *sk = sock->sk;
3878 struct packet_sock *po = pkt_sk(sk);
3879 void *data = &val;
3880 union tpacket_stats_u st;
3881 struct tpacket_rollover_stats rstats;
3882
3883 if (level != SOL_PACKET)
3884 return -ENOPROTOOPT;
3885
3886 if (get_user(len, optlen))
3887 return -EFAULT;
3888
3889 if (len < 0)
3890 return -EINVAL;
3891
3892 switch (optname) {
3893 case PACKET_STATISTICS:
3894 spin_lock_bh(&sk->sk_receive_queue.lock);
3895 memcpy(&st, &po->stats, sizeof(st));
3896 memset(&po->stats, 0, sizeof(po->stats));
3897 spin_unlock_bh(&sk->sk_receive_queue.lock);
3898
3899 if (po->tp_version == TPACKET_V3) {
3900 lv = sizeof(struct tpacket_stats_v3);
3901 st.stats3.tp_packets += st.stats3.tp_drops;
3902 data = &st.stats3;
3903 } else {
3904 lv = sizeof(struct tpacket_stats);
3905 st.stats1.tp_packets += st.stats1.tp_drops;
3906 data = &st.stats1;
3907 }
3908
3909 break;
3910 case PACKET_AUXDATA:
3911 val = po->auxdata;
3912 break;
3913 case PACKET_ORIGDEV:
3914 val = po->origdev;
3915 break;
3916 case PACKET_VNET_HDR:
3917 val = po->has_vnet_hdr;
3918 break;
3919 case PACKET_VERSION:
3920 val = po->tp_version;
3921 break;
3922 case PACKET_HDRLEN:
3923 if (len > sizeof(int))
3924 len = sizeof(int);
3925 if (len < sizeof(int))
3926 return -EINVAL;
3927 if (copy_from_user(&val, optval, len))
3928 return -EFAULT;
3929 switch (val) {
3930 case TPACKET_V1:
3931 val = sizeof(struct tpacket_hdr);
3932 break;
3933 case TPACKET_V2:
3934 val = sizeof(struct tpacket2_hdr);
3935 break;
3936 case TPACKET_V3:
3937 val = sizeof(struct tpacket3_hdr);
3938 break;
3939 default:
3940 return -EINVAL;
3941 }
3942 break;
3943 case PACKET_RESERVE:
3944 val = po->tp_reserve;
3945 break;
3946 case PACKET_LOSS:
3947 val = po->tp_loss;
3948 break;
3949 case PACKET_TIMESTAMP:
3950 val = po->tp_tstamp;
3951 break;
3952 case PACKET_FANOUT:
3953 val = (po->fanout ?
3954 ((u32)po->fanout->id |
3955 ((u32)po->fanout->type << 16) |
3956 ((u32)po->fanout->flags << 24)) :
3957 0);
3958 break;
3959 case PACKET_ROLLOVER_STATS:
3960 if (!po->rollover)
3961 return -EINVAL;
3962 rstats.tp_all = atomic_long_read(&po->rollover->num);
3963 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3964 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3965 data = &rstats;
3966 lv = sizeof(rstats);
3967 break;
3968 case PACKET_TX_HAS_OFF:
3969 val = po->tp_tx_has_off;
3970 break;
3971 case PACKET_QDISC_BYPASS:
3972 val = packet_use_direct_xmit(po);
3973 break;
3974 default:
3975 return -ENOPROTOOPT;
3976 }
3977
3978 if (len > lv)
3979 len = lv;
3980 if (put_user(len, optlen))
3981 return -EFAULT;
3982 if (copy_to_user(optval, data, len))
3983 return -EFAULT;
3984 return 0;
3985}
3986
3987
3988#ifdef CONFIG_COMPAT
3989static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
3990 char __user *optval, unsigned int optlen)
3991{
3992 struct packet_sock *po = pkt_sk(sock->sk);
3993
3994 if (level != SOL_PACKET)
3995 return -ENOPROTOOPT;
3996
3997 if (optname == PACKET_FANOUT_DATA &&
3998 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
3999 optval = (char __user *)get_compat_bpf_fprog(optval);
4000 if (!optval)
4001 return -EFAULT;
4002 optlen = sizeof(struct sock_fprog);
4003 }
4004
4005 return packet_setsockopt(sock, level, optname, optval, optlen);
4006}
4007#endif
4008
4009static int packet_notifier(struct notifier_block *this,
4010 unsigned long msg, void *ptr)
4011{
4012 struct sock *sk;
4013 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4014 struct net *net = dev_net(dev);
4015
4016 rcu_read_lock();
4017 sk_for_each_rcu(sk, &net->packet.sklist) {
4018 struct packet_sock *po = pkt_sk(sk);
4019
4020 switch (msg) {
4021 case NETDEV_UNREGISTER:
4022 if (po->mclist)
4023 packet_dev_mclist_delete(dev, &po->mclist);
4024 /* fallthrough */
4025
4026 case NETDEV_DOWN:
4027 if (dev->ifindex == po->ifindex) {
4028 spin_lock(&po->bind_lock);
4029 if (po->running) {
4030 __unregister_prot_hook(sk, false);
4031 sk->sk_err = ENETDOWN;
4032 if (!sock_flag(sk, SOCK_DEAD))
4033 sk->sk_error_report(sk);
4034 }
4035 if (msg == NETDEV_UNREGISTER) {
4036 packet_cached_dev_reset(po);
4037 po->ifindex = -1;
4038 if (po->prot_hook.dev)
4039 dev_put(po->prot_hook.dev);
4040 po->prot_hook.dev = NULL;
4041 }
4042 spin_unlock(&po->bind_lock);
4043 }
4044 break;
4045 case NETDEV_UP:
4046 if (dev->ifindex == po->ifindex) {
4047 spin_lock(&po->bind_lock);
4048 if (po->num)
4049 register_prot_hook(sk);
4050 spin_unlock(&po->bind_lock);
4051 }
4052 break;
4053 }
4054 }
4055 rcu_read_unlock();
4056 return NOTIFY_DONE;
4057}
4058
4059
4060static int packet_ioctl(struct socket *sock, unsigned int cmd,
4061 unsigned long arg)
4062{
4063 struct sock *sk = sock->sk;
4064
4065 switch (cmd) {
4066 case SIOCOUTQ:
4067 {
4068 int amount = sk_wmem_alloc_get(sk);
4069
4070 return put_user(amount, (int __user *)arg);
4071 }
4072 case SIOCINQ:
4073 {
4074 struct sk_buff *skb;
4075 int amount = 0;
4076
4077 spin_lock_bh(&sk->sk_receive_queue.lock);
4078 skb = skb_peek(&sk->sk_receive_queue);
4079 if (skb)
4080 amount = skb->len;
4081 spin_unlock_bh(&sk->sk_receive_queue.lock);
4082 return put_user(amount, (int __user *)arg);
4083 }
4084 case SIOCGSTAMP:
4085 return sock_get_timestamp(sk, (struct timeval __user *)arg);
4086 case SIOCGSTAMPNS:
4087 return sock_get_timestampns(sk, (struct timespec __user *)arg);
4088
4089#ifdef CONFIG_INET
4090 case SIOCADDRT:
4091 case SIOCDELRT:
4092 case SIOCDARP:
4093 case SIOCGARP:
4094 case SIOCSARP:
4095 case SIOCGIFADDR:
4096 case SIOCSIFADDR:
4097 case SIOCGIFBRDADDR:
4098 case SIOCSIFBRDADDR:
4099 case SIOCGIFNETMASK:
4100 case SIOCSIFNETMASK:
4101 case SIOCGIFDSTADDR:
4102 case SIOCSIFDSTADDR:
4103 case SIOCSIFFLAGS:
4104 return inet_dgram_ops.ioctl(sock, cmd, arg);
4105#endif
4106
4107 default:
4108 return -ENOIOCTLCMD;
4109 }
4110 return 0;
4111}
4112
4113static __poll_t packet_poll(struct file *file, struct socket *sock,
4114 poll_table *wait)
4115{
4116 struct sock *sk = sock->sk;
4117 struct packet_sock *po = pkt_sk(sk);
4118 __poll_t mask = datagram_poll(file, sock, wait);
4119
4120 spin_lock_bh(&sk->sk_receive_queue.lock);
4121 if (po->rx_ring.pg_vec) {
4122 if (!packet_previous_rx_frame(po, &po->rx_ring,
4123 TP_STATUS_KERNEL))
4124 mask |= EPOLLIN | EPOLLRDNORM;
4125 }
4126 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
4127 po->pressure = 0;
4128 spin_unlock_bh(&sk->sk_receive_queue.lock);
4129 spin_lock_bh(&sk->sk_write_queue.lock);
4130 if (po->tx_ring.pg_vec) {
4131 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4132 mask |= EPOLLOUT | EPOLLWRNORM;
4133 }
4134 spin_unlock_bh(&sk->sk_write_queue.lock);
4135 return mask;
4136}
4137
4138
4139/* Dirty? Well, I still did not learn better way to account
4140 * for user mmaps.
4141 */
4142
4143static void packet_mm_open(struct vm_area_struct *vma)
4144{
4145 struct file *file = vma->vm_file;
4146 struct socket *sock = file->private_data;
4147 struct sock *sk = sock->sk;
4148
4149 if (sk)
4150 atomic_inc(&pkt_sk(sk)->mapped);
4151}
4152
4153static void packet_mm_close(struct vm_area_struct *vma)
4154{
4155 struct file *file = vma->vm_file;
4156 struct socket *sock = file->private_data;
4157 struct sock *sk = sock->sk;
4158
4159 if (sk)
4160 atomic_dec(&pkt_sk(sk)->mapped);
4161}
4162
4163static const struct vm_operations_struct packet_mmap_ops = {
4164 .open = packet_mm_open,
4165 .close = packet_mm_close,
4166};
4167
4168static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4169 unsigned int len)
4170{
4171 int i;
4172
4173 for (i = 0; i < len; i++) {
4174 if (likely(pg_vec[i].buffer)) {
4175 if (is_vmalloc_addr(pg_vec[i].buffer))
4176 vfree(pg_vec[i].buffer);
4177 else
4178 free_pages((unsigned long)pg_vec[i].buffer,
4179 order);
4180 pg_vec[i].buffer = NULL;
4181 }
4182 }
4183 kfree(pg_vec);
4184}
4185
4186static char *alloc_one_pg_vec_page(unsigned long order)
4187{
4188 char *buffer;
4189 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4190 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4191
4192 buffer = (char *) __get_free_pages(gfp_flags, order);
4193 if (buffer)
4194 return buffer;
4195
4196 /* __get_free_pages failed, fall back to vmalloc */
4197 buffer = vzalloc((1 << order) * PAGE_SIZE);
4198 if (buffer)
4199 return buffer;
4200
4201 /* vmalloc failed, lets dig into swap here */
4202 gfp_flags &= ~__GFP_NORETRY;
4203 buffer = (char *) __get_free_pages(gfp_flags, order);
4204 if (buffer)
4205 return buffer;
4206
4207 /* complete and utter failure */
4208 return NULL;
4209}
4210
4211static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4212{
4213 unsigned int block_nr = req->tp_block_nr;
4214 struct pgv *pg_vec;
4215 int i;
4216
4217 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4218 if (unlikely(!pg_vec))
4219 goto out;
4220
4221 for (i = 0; i < block_nr; i++) {
4222 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4223 if (unlikely(!pg_vec[i].buffer))
4224 goto out_free_pgvec;
4225 }
4226
4227out:
4228 return pg_vec;
4229
4230out_free_pgvec:
4231 free_pg_vec(pg_vec, order, block_nr);
4232 pg_vec = NULL;
4233 goto out;
4234}
4235
4236static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4237 int closing, int tx_ring)
4238{
4239 struct pgv *pg_vec = NULL;
4240 struct packet_sock *po = pkt_sk(sk);
4241 int was_running, order = 0;
4242 struct packet_ring_buffer *rb;
4243 struct sk_buff_head *rb_queue;
4244 __be16 num;
4245 int err = -EINVAL;
4246 /* Added to avoid minimal code churn */
4247 struct tpacket_req *req = &req_u->req;
4248
4249 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4250 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4251
4252 err = -EBUSY;
4253 if (!closing) {
4254 if (atomic_read(&po->mapped))
4255 goto out;
4256 if (packet_read_pending(rb))
4257 goto out;
4258 }
4259
4260 if (req->tp_block_nr) {
4261 /* Sanity tests and some calculations */
4262 err = -EBUSY;
4263 if (unlikely(rb->pg_vec))
4264 goto out;
4265
4266 switch (po->tp_version) {
4267 case TPACKET_V1:
4268 po->tp_hdrlen = TPACKET_HDRLEN;
4269 break;
4270 case TPACKET_V2:
4271 po->tp_hdrlen = TPACKET2_HDRLEN;
4272 break;
4273 case TPACKET_V3:
4274 po->tp_hdrlen = TPACKET3_HDRLEN;
4275 break;
4276 }
4277
4278 err = -EINVAL;
4279 if (unlikely((int)req->tp_block_size <= 0))
4280 goto out;
4281 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4282 goto out;
4283 if (po->tp_version >= TPACKET_V3 &&
4284 req->tp_block_size <=
4285 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
4286 goto out;
4287 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4288 po->tp_reserve))
4289 goto out;
4290 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4291 goto out;
4292
4293 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4294 if (unlikely(rb->frames_per_block == 0))
4295 goto out;
4296 if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
4297 goto out;
4298 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4299 req->tp_frame_nr))
4300 goto out;
4301
4302 err = -ENOMEM;
4303 order = get_order(req->tp_block_size);
4304 pg_vec = alloc_pg_vec(req, order);
4305 if (unlikely(!pg_vec))
4306 goto out;
4307 switch (po->tp_version) {
4308 case TPACKET_V3:
4309 /* Block transmit is not supported yet */
4310 if (!tx_ring) {
4311 init_prb_bdqc(po, rb, pg_vec, req_u);
4312 } else {
4313 struct tpacket_req3 *req3 = &req_u->req3;
4314
4315 if (req3->tp_retire_blk_tov ||
4316 req3->tp_sizeof_priv ||
4317 req3->tp_feature_req_word) {
4318 err = -EINVAL;
4319 goto out;
4320 }
4321 }
4322 break;
4323 default:
4324 break;
4325 }
4326 }
4327 /* Done */
4328 else {
4329 err = -EINVAL;
4330 if (unlikely(req->tp_frame_nr))
4331 goto out;
4332 }
4333
4334
4335 /* Detach socket from network */
4336 spin_lock(&po->bind_lock);
4337 was_running = po->running;
4338 num = po->num;
4339 if (was_running) {
4340 po->num = 0;
4341 __unregister_prot_hook(sk, false);
4342 }
4343 spin_unlock(&po->bind_lock);
4344
4345 synchronize_net();
4346
4347 err = -EBUSY;
4348 mutex_lock(&po->pg_vec_lock);
4349 if (closing || atomic_read(&po->mapped) == 0) {
4350 err = 0;
4351 spin_lock_bh(&rb_queue->lock);
4352 swap(rb->pg_vec, pg_vec);
4353 rb->frame_max = (req->tp_frame_nr - 1);
4354 rb->head = 0;
4355 rb->frame_size = req->tp_frame_size;
4356 spin_unlock_bh(&rb_queue->lock);
4357
4358 swap(rb->pg_vec_order, order);
4359 swap(rb->pg_vec_len, req->tp_block_nr);
4360
4361 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4362 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4363 tpacket_rcv : packet_rcv;
4364 skb_queue_purge(rb_queue);
4365 if (atomic_read(&po->mapped))
4366 pr_err("packet_mmap: vma is busy: %d\n",
4367 atomic_read(&po->mapped));
4368 }
4369 mutex_unlock(&po->pg_vec_lock);
4370
4371 spin_lock(&po->bind_lock);
4372 if (was_running) {
4373 po->num = num;
4374 register_prot_hook(sk);
4375 }
4376 spin_unlock(&po->bind_lock);
4377 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4378 /* Because we don't support block-based V3 on tx-ring */
4379 if (!tx_ring)
4380 prb_shutdown_retire_blk_timer(po, rb_queue);
4381 }
4382
4383 if (pg_vec)
4384 free_pg_vec(pg_vec, order, req->tp_block_nr);
4385out:
4386 return err;
4387}
4388
4389static int packet_mmap(struct file *file, struct socket *sock,
4390 struct vm_area_struct *vma)
4391{
4392 struct sock *sk = sock->sk;
4393 struct packet_sock *po = pkt_sk(sk);
4394 unsigned long size, expected_size;
4395 struct packet_ring_buffer *rb;
4396 unsigned long start;
4397 int err = -EINVAL;
4398 int i;
4399
4400 if (vma->vm_pgoff)
4401 return -EINVAL;
4402
4403 mutex_lock(&po->pg_vec_lock);
4404
4405 expected_size = 0;
4406 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4407 if (rb->pg_vec) {
4408 expected_size += rb->pg_vec_len
4409 * rb->pg_vec_pages
4410 * PAGE_SIZE;
4411 }
4412 }
4413
4414 if (expected_size == 0)
4415 goto out;
4416
4417 size = vma->vm_end - vma->vm_start;
4418 if (size != expected_size)
4419 goto out;
4420
4421 start = vma->vm_start;
4422 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4423 if (rb->pg_vec == NULL)
4424 continue;
4425
4426 for (i = 0; i < rb->pg_vec_len; i++) {
4427 struct page *page;
4428 void *kaddr = rb->pg_vec[i].buffer;
4429 int pg_num;
4430
4431 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4432 page = pgv_to_page(kaddr);
4433 err = vm_insert_page(vma, start, page);
4434 if (unlikely(err))
4435 goto out;
4436 start += PAGE_SIZE;
4437 kaddr += PAGE_SIZE;
4438 }
4439 }
4440 }
4441
4442 atomic_inc(&po->mapped);
4443 vma->vm_ops = &packet_mmap_ops;
4444 err = 0;
4445
4446out:
4447 mutex_unlock(&po->pg_vec_lock);
4448 return err;
4449}
4450
4451static const struct proto_ops packet_ops_spkt = {
4452 .family = PF_PACKET,
4453 .owner = THIS_MODULE,
4454 .release = packet_release,
4455 .bind = packet_bind_spkt,
4456 .connect = sock_no_connect,
4457 .socketpair = sock_no_socketpair,
4458 .accept = sock_no_accept,
4459 .getname = packet_getname_spkt,
4460 .poll = datagram_poll,
4461 .ioctl = packet_ioctl,
4462 .listen = sock_no_listen,
4463 .shutdown = sock_no_shutdown,
4464 .setsockopt = sock_no_setsockopt,
4465 .getsockopt = sock_no_getsockopt,
4466 .sendmsg = packet_sendmsg_spkt,
4467 .recvmsg = packet_recvmsg,
4468 .mmap = sock_no_mmap,
4469 .sendpage = sock_no_sendpage,
4470};
4471
4472static const struct proto_ops packet_ops = {
4473 .family = PF_PACKET,
4474 .owner = THIS_MODULE,
4475 .release = packet_release,
4476 .bind = packet_bind,
4477 .connect = sock_no_connect,
4478 .socketpair = sock_no_socketpair,
4479 .accept = sock_no_accept,
4480 .getname = packet_getname,
4481 .poll = packet_poll,
4482 .ioctl = packet_ioctl,
4483 .listen = sock_no_listen,
4484 .shutdown = sock_no_shutdown,
4485 .setsockopt = packet_setsockopt,
4486 .getsockopt = packet_getsockopt,
4487#ifdef CONFIG_COMPAT
4488 .compat_setsockopt = compat_packet_setsockopt,
4489#endif
4490 .sendmsg = packet_sendmsg,
4491 .recvmsg = packet_recvmsg,
4492 .mmap = packet_mmap,
4493 .sendpage = sock_no_sendpage,
4494};
4495
4496static const struct net_proto_family packet_family_ops = {
4497 .family = PF_PACKET,
4498 .create = packet_create,
4499 .owner = THIS_MODULE,
4500};
4501
4502static struct notifier_block packet_netdev_notifier = {
4503 .notifier_call = packet_notifier,
4504};
4505
4506#ifdef CONFIG_PROC_FS
4507
4508static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4509 __acquires(RCU)
4510{
4511 struct net *net = seq_file_net(seq);
4512
4513 rcu_read_lock();
4514 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4515}
4516
4517static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4518{
4519 struct net *net = seq_file_net(seq);
4520 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4521}
4522
4523static void packet_seq_stop(struct seq_file *seq, void *v)
4524 __releases(RCU)
4525{
4526 rcu_read_unlock();
4527}
4528
4529static int packet_seq_show(struct seq_file *seq, void *v)
4530{
4531 if (v == SEQ_START_TOKEN)
4532 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4533 else {
4534 struct sock *s = sk_entry(v);
4535 const struct packet_sock *po = pkt_sk(s);
4536
4537 seq_printf(seq,
4538 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4539 s,
4540 refcount_read(&s->sk_refcnt),
4541 s->sk_type,
4542 ntohs(po->num),
4543 po->ifindex,
4544 po->running,
4545 atomic_read(&s->sk_rmem_alloc),
4546 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4547 sock_i_ino(s));
4548 }
4549
4550 return 0;
4551}
4552
4553static const struct seq_operations packet_seq_ops = {
4554 .start = packet_seq_start,
4555 .next = packet_seq_next,
4556 .stop = packet_seq_stop,
4557 .show = packet_seq_show,
4558};
4559
4560static int packet_seq_open(struct inode *inode, struct file *file)
4561{
4562 return seq_open_net(inode, file, &packet_seq_ops,
4563 sizeof(struct seq_net_private));
4564}
4565
4566static const struct file_operations packet_seq_fops = {
4567 .open = packet_seq_open,
4568 .read = seq_read,
4569 .llseek = seq_lseek,
4570 .release = seq_release_net,
4571};
4572
4573#endif
4574
4575static int __net_init packet_net_init(struct net *net)
4576{
4577 mutex_init(&net->packet.sklist_lock);
4578 INIT_HLIST_HEAD(&net->packet.sklist);
4579
4580 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4581 return -ENOMEM;
4582
4583 return 0;
4584}
4585
4586static void __net_exit packet_net_exit(struct net *net)
4587{
4588 remove_proc_entry("packet", net->proc_net);
4589 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4590}
4591
4592static struct pernet_operations packet_net_ops = {
4593 .init = packet_net_init,
4594 .exit = packet_net_exit,
4595};
4596
4597
4598static void __exit packet_exit(void)
4599{
4600 unregister_netdevice_notifier(&packet_netdev_notifier);
4601 unregister_pernet_subsys(&packet_net_ops);
4602 sock_unregister(PF_PACKET);
4603 proto_unregister(&packet_proto);
4604}
4605
4606static int __init packet_init(void)
4607{
4608 int rc = proto_register(&packet_proto, 0);
4609
4610 if (rc != 0)
4611 goto out;
4612
4613 sock_register(&packet_family_ops);
4614 register_pernet_subsys(&packet_net_ops);
4615 register_netdevice_notifier(&packet_netdev_notifier);
4616out:
4617 return rc;
4618}
4619
4620module_init(packet_init);
4621module_exit(packet_exit);
4622MODULE_LICENSE("GPL");
4623MODULE_ALIAS_NETPROTO(PF_PACKET);