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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 PGV_FROM_VMALLOC 1
181
182#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
183#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
184#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
185#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
186#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
187#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
188#define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
189
190struct packet_sock;
191static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
192static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
193 struct packet_type *pt, struct net_device *orig_dev);
194
195static void *packet_previous_frame(struct packet_sock *po,
196 struct packet_ring_buffer *rb,
197 int status);
198static void packet_increment_head(struct packet_ring_buffer *buff);
199static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
200 struct tpacket_block_desc *);
201static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
202 struct packet_sock *);
203static void prb_retire_current_block(struct tpacket_kbdq_core *,
204 struct packet_sock *, unsigned int status);
205static int prb_queue_frozen(struct tpacket_kbdq_core *);
206static void prb_open_block(struct tpacket_kbdq_core *,
207 struct tpacket_block_desc *);
208static void prb_retire_rx_blk_timer_expired(unsigned long);
209static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
210static void prb_init_blk_timer(struct packet_sock *,
211 struct tpacket_kbdq_core *,
212 void (*func) (unsigned long));
213static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
214static void prb_clear_rxhash(struct tpacket_kbdq_core *,
215 struct tpacket3_hdr *);
216static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
217 struct tpacket3_hdr *);
218static void packet_flush_mclist(struct sock *sk);
219
220struct packet_skb_cb {
221 union {
222 struct sockaddr_pkt pkt;
223 union {
224 /* Trick: alias skb original length with
225 * ll.sll_family and ll.protocol in order
226 * to save room.
227 */
228 unsigned int origlen;
229 struct sockaddr_ll ll;
230 };
231 } sa;
232};
233
234#define vio_le() virtio_legacy_is_little_endian()
235
236#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
237
238#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
239#define GET_PBLOCK_DESC(x, bid) \
240 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
241#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
242 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
243#define GET_NEXT_PRB_BLK_NUM(x) \
244 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
245 ((x)->kactive_blk_num+1) : 0)
246
247static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
248static void __fanout_link(struct sock *sk, struct packet_sock *po);
249
250static int packet_direct_xmit(struct sk_buff *skb)
251{
252 struct net_device *dev = skb->dev;
253 struct sk_buff *orig_skb = skb;
254 struct netdev_queue *txq;
255 int ret = NETDEV_TX_BUSY;
256
257 if (unlikely(!netif_running(dev) ||
258 !netif_carrier_ok(dev)))
259 goto drop;
260
261 skb = validate_xmit_skb_list(skb, dev);
262 if (skb != orig_skb)
263 goto drop;
264
265 txq = skb_get_tx_queue(dev, skb);
266
267 local_bh_disable();
268
269 HARD_TX_LOCK(dev, txq, smp_processor_id());
270 if (!netif_xmit_frozen_or_drv_stopped(txq))
271 ret = netdev_start_xmit(skb, dev, txq, false);
272 HARD_TX_UNLOCK(dev, txq);
273
274 local_bh_enable();
275
276 if (!dev_xmit_complete(ret))
277 kfree_skb(skb);
278
279 return ret;
280drop:
281 atomic_long_inc(&dev->tx_dropped);
282 kfree_skb_list(skb);
283 return NET_XMIT_DROP;
284}
285
286static struct net_device *packet_cached_dev_get(struct packet_sock *po)
287{
288 struct net_device *dev;
289
290 rcu_read_lock();
291 dev = rcu_dereference(po->cached_dev);
292 if (likely(dev))
293 dev_hold(dev);
294 rcu_read_unlock();
295
296 return dev;
297}
298
299static void packet_cached_dev_assign(struct packet_sock *po,
300 struct net_device *dev)
301{
302 rcu_assign_pointer(po->cached_dev, dev);
303}
304
305static void packet_cached_dev_reset(struct packet_sock *po)
306{
307 RCU_INIT_POINTER(po->cached_dev, NULL);
308}
309
310static bool packet_use_direct_xmit(const struct packet_sock *po)
311{
312 return po->xmit == packet_direct_xmit;
313}
314
315static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
316{
317 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
318}
319
320static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
321{
322 const struct net_device_ops *ops = dev->netdev_ops;
323 u16 queue_index;
324
325 if (ops->ndo_select_queue) {
326 queue_index = ops->ndo_select_queue(dev, skb, NULL,
327 __packet_pick_tx_queue);
328 queue_index = netdev_cap_txqueue(dev, queue_index);
329 } else {
330 queue_index = __packet_pick_tx_queue(dev, skb);
331 }
332
333 skb_set_queue_mapping(skb, queue_index);
334}
335
336/* register_prot_hook must be invoked with the po->bind_lock held,
337 * or from a context in which asynchronous accesses to the packet
338 * socket is not possible (packet_create()).
339 */
340static void register_prot_hook(struct sock *sk)
341{
342 struct packet_sock *po = pkt_sk(sk);
343
344 if (!po->running) {
345 if (po->fanout)
346 __fanout_link(sk, po);
347 else
348 dev_add_pack(&po->prot_hook);
349
350 sock_hold(sk);
351 po->running = 1;
352 }
353}
354
355/* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
356 * held. If the sync parameter is true, we will temporarily drop
357 * the po->bind_lock and do a synchronize_net to make sure no
358 * asynchronous packet processing paths still refer to the elements
359 * of po->prot_hook. If the sync parameter is false, it is the
360 * callers responsibility to take care of this.
361 */
362static void __unregister_prot_hook(struct sock *sk, bool sync)
363{
364 struct packet_sock *po = pkt_sk(sk);
365
366 po->running = 0;
367
368 if (po->fanout)
369 __fanout_unlink(sk, po);
370 else
371 __dev_remove_pack(&po->prot_hook);
372
373 __sock_put(sk);
374
375 if (sync) {
376 spin_unlock(&po->bind_lock);
377 synchronize_net();
378 spin_lock(&po->bind_lock);
379 }
380}
381
382static void unregister_prot_hook(struct sock *sk, bool sync)
383{
384 struct packet_sock *po = pkt_sk(sk);
385
386 if (po->running)
387 __unregister_prot_hook(sk, sync);
388}
389
390static inline struct page * __pure pgv_to_page(void *addr)
391{
392 if (is_vmalloc_addr(addr))
393 return vmalloc_to_page(addr);
394 return virt_to_page(addr);
395}
396
397static void __packet_set_status(struct packet_sock *po, void *frame, int status)
398{
399 union tpacket_uhdr h;
400
401 h.raw = frame;
402 switch (po->tp_version) {
403 case TPACKET_V1:
404 h.h1->tp_status = status;
405 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
406 break;
407 case TPACKET_V2:
408 h.h2->tp_status = status;
409 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
410 break;
411 case TPACKET_V3:
412 default:
413 WARN(1, "TPACKET version not supported.\n");
414 BUG();
415 }
416
417 smp_wmb();
418}
419
420static int __packet_get_status(struct packet_sock *po, void *frame)
421{
422 union tpacket_uhdr h;
423
424 smp_rmb();
425
426 h.raw = frame;
427 switch (po->tp_version) {
428 case TPACKET_V1:
429 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
430 return h.h1->tp_status;
431 case TPACKET_V2:
432 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
433 return h.h2->tp_status;
434 case TPACKET_V3:
435 default:
436 WARN(1, "TPACKET version not supported.\n");
437 BUG();
438 return 0;
439 }
440}
441
442static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
443 unsigned int flags)
444{
445 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
446
447 if (shhwtstamps &&
448 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
449 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
450 return TP_STATUS_TS_RAW_HARDWARE;
451
452 if (ktime_to_timespec_cond(skb->tstamp, ts))
453 return TP_STATUS_TS_SOFTWARE;
454
455 return 0;
456}
457
458static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
459 struct sk_buff *skb)
460{
461 union tpacket_uhdr h;
462 struct timespec ts;
463 __u32 ts_status;
464
465 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
466 return 0;
467
468 h.raw = frame;
469 switch (po->tp_version) {
470 case TPACKET_V1:
471 h.h1->tp_sec = ts.tv_sec;
472 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
473 break;
474 case TPACKET_V2:
475 h.h2->tp_sec = ts.tv_sec;
476 h.h2->tp_nsec = ts.tv_nsec;
477 break;
478 case TPACKET_V3:
479 default:
480 WARN(1, "TPACKET version not supported.\n");
481 BUG();
482 }
483
484 /* one flush is safe, as both fields always lie on the same cacheline */
485 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
486 smp_wmb();
487
488 return ts_status;
489}
490
491static void *packet_lookup_frame(struct packet_sock *po,
492 struct packet_ring_buffer *rb,
493 unsigned int position,
494 int status)
495{
496 unsigned int pg_vec_pos, frame_offset;
497 union tpacket_uhdr h;
498
499 pg_vec_pos = position / rb->frames_per_block;
500 frame_offset = position % rb->frames_per_block;
501
502 h.raw = rb->pg_vec[pg_vec_pos].buffer +
503 (frame_offset * rb->frame_size);
504
505 if (status != __packet_get_status(po, h.raw))
506 return NULL;
507
508 return h.raw;
509}
510
511static void *packet_current_frame(struct packet_sock *po,
512 struct packet_ring_buffer *rb,
513 int status)
514{
515 return packet_lookup_frame(po, rb, rb->head, status);
516}
517
518static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
519{
520 del_timer_sync(&pkc->retire_blk_timer);
521}
522
523static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
524 struct sk_buff_head *rb_queue)
525{
526 struct tpacket_kbdq_core *pkc;
527
528 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
529
530 spin_lock_bh(&rb_queue->lock);
531 pkc->delete_blk_timer = 1;
532 spin_unlock_bh(&rb_queue->lock);
533
534 prb_del_retire_blk_timer(pkc);
535}
536
537static void prb_init_blk_timer(struct packet_sock *po,
538 struct tpacket_kbdq_core *pkc,
539 void (*func) (unsigned long))
540{
541 init_timer(&pkc->retire_blk_timer);
542 pkc->retire_blk_timer.data = (long)po;
543 pkc->retire_blk_timer.function = func;
544 pkc->retire_blk_timer.expires = jiffies;
545}
546
547static void prb_setup_retire_blk_timer(struct packet_sock *po)
548{
549 struct tpacket_kbdq_core *pkc;
550
551 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
552 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
553}
554
555static int prb_calc_retire_blk_tmo(struct packet_sock *po,
556 int blk_size_in_bytes)
557{
558 struct net_device *dev;
559 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
560 struct ethtool_link_ksettings ecmd;
561 int err;
562
563 rtnl_lock();
564 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
565 if (unlikely(!dev)) {
566 rtnl_unlock();
567 return DEFAULT_PRB_RETIRE_TOV;
568 }
569 err = __ethtool_get_link_ksettings(dev, &ecmd);
570 rtnl_unlock();
571 if (!err) {
572 /*
573 * If the link speed is so slow you don't really
574 * need to worry about perf anyways
575 */
576 if (ecmd.base.speed < SPEED_1000 ||
577 ecmd.base.speed == SPEED_UNKNOWN) {
578 return DEFAULT_PRB_RETIRE_TOV;
579 } else {
580 msec = 1;
581 div = ecmd.base.speed / 1000;
582 }
583 }
584
585 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
586
587 if (div)
588 mbits /= div;
589
590 tmo = mbits * msec;
591
592 if (div)
593 return tmo+1;
594 return tmo;
595}
596
597static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
598 union tpacket_req_u *req_u)
599{
600 p1->feature_req_word = req_u->req3.tp_feature_req_word;
601}
602
603static void init_prb_bdqc(struct packet_sock *po,
604 struct packet_ring_buffer *rb,
605 struct pgv *pg_vec,
606 union tpacket_req_u *req_u)
607{
608 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
609 struct tpacket_block_desc *pbd;
610
611 memset(p1, 0x0, sizeof(*p1));
612
613 p1->knxt_seq_num = 1;
614 p1->pkbdq = pg_vec;
615 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
616 p1->pkblk_start = pg_vec[0].buffer;
617 p1->kblk_size = req_u->req3.tp_block_size;
618 p1->knum_blocks = req_u->req3.tp_block_nr;
619 p1->hdrlen = po->tp_hdrlen;
620 p1->version = po->tp_version;
621 p1->last_kactive_blk_num = 0;
622 po->stats.stats3.tp_freeze_q_cnt = 0;
623 if (req_u->req3.tp_retire_blk_tov)
624 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
625 else
626 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
627 req_u->req3.tp_block_size);
628 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
629 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
630
631 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
632 prb_init_ft_ops(p1, req_u);
633 prb_setup_retire_blk_timer(po);
634 prb_open_block(p1, pbd);
635}
636
637/* Do NOT update the last_blk_num first.
638 * Assumes sk_buff_head lock is held.
639 */
640static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
641{
642 mod_timer(&pkc->retire_blk_timer,
643 jiffies + pkc->tov_in_jiffies);
644 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
645}
646
647/*
648 * Timer logic:
649 * 1) We refresh the timer only when we open a block.
650 * By doing this we don't waste cycles refreshing the timer
651 * on packet-by-packet basis.
652 *
653 * With a 1MB block-size, on a 1Gbps line, it will take
654 * i) ~8 ms to fill a block + ii) memcpy etc.
655 * In this cut we are not accounting for the memcpy time.
656 *
657 * So, if the user sets the 'tmo' to 10ms then the timer
658 * will never fire while the block is still getting filled
659 * (which is what we want). However, the user could choose
660 * to close a block early and that's fine.
661 *
662 * But when the timer does fire, we check whether or not to refresh it.
663 * Since the tmo granularity is in msecs, it is not too expensive
664 * to refresh the timer, lets say every '8' msecs.
665 * Either the user can set the 'tmo' or we can derive it based on
666 * a) line-speed and b) block-size.
667 * prb_calc_retire_blk_tmo() calculates the tmo.
668 *
669 */
670static void prb_retire_rx_blk_timer_expired(unsigned long data)
671{
672 struct packet_sock *po = (struct packet_sock *)data;
673 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
674 unsigned int frozen;
675 struct tpacket_block_desc *pbd;
676
677 spin_lock(&po->sk.sk_receive_queue.lock);
678
679 frozen = prb_queue_frozen(pkc);
680 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
681
682 if (unlikely(pkc->delete_blk_timer))
683 goto out;
684
685 /* We only need to plug the race when the block is partially filled.
686 * tpacket_rcv:
687 * lock(); increment BLOCK_NUM_PKTS; unlock()
688 * copy_bits() is in progress ...
689 * timer fires on other cpu:
690 * we can't retire the current block because copy_bits
691 * is in progress.
692 *
693 */
694 if (BLOCK_NUM_PKTS(pbd)) {
695 while (atomic_read(&pkc->blk_fill_in_prog)) {
696 /* Waiting for skb_copy_bits to finish... */
697 cpu_relax();
698 }
699 }
700
701 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
702 if (!frozen) {
703 if (!BLOCK_NUM_PKTS(pbd)) {
704 /* An empty block. Just refresh the timer. */
705 goto refresh_timer;
706 }
707 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
708 if (!prb_dispatch_next_block(pkc, po))
709 goto refresh_timer;
710 else
711 goto out;
712 } else {
713 /* Case 1. Queue was frozen because user-space was
714 * lagging behind.
715 */
716 if (prb_curr_blk_in_use(pkc, pbd)) {
717 /*
718 * Ok, user-space is still behind.
719 * So just refresh the timer.
720 */
721 goto refresh_timer;
722 } else {
723 /* Case 2. queue was frozen,user-space caught up,
724 * now the link went idle && the timer fired.
725 * We don't have a block to close.So we open this
726 * block and restart the timer.
727 * opening a block thaws the queue,restarts timer
728 * Thawing/timer-refresh is a side effect.
729 */
730 prb_open_block(pkc, pbd);
731 goto out;
732 }
733 }
734 }
735
736refresh_timer:
737 _prb_refresh_rx_retire_blk_timer(pkc);
738
739out:
740 spin_unlock(&po->sk.sk_receive_queue.lock);
741}
742
743static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
744 struct tpacket_block_desc *pbd1, __u32 status)
745{
746 /* Flush everything minus the block header */
747
748#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
749 u8 *start, *end;
750
751 start = (u8 *)pbd1;
752
753 /* Skip the block header(we know header WILL fit in 4K) */
754 start += PAGE_SIZE;
755
756 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
757 for (; start < end; start += PAGE_SIZE)
758 flush_dcache_page(pgv_to_page(start));
759
760 smp_wmb();
761#endif
762
763 /* Now update the block status. */
764
765 BLOCK_STATUS(pbd1) = status;
766
767 /* Flush the block header */
768
769#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
770 start = (u8 *)pbd1;
771 flush_dcache_page(pgv_to_page(start));
772
773 smp_wmb();
774#endif
775}
776
777/*
778 * Side effect:
779 *
780 * 1) flush the block
781 * 2) Increment active_blk_num
782 *
783 * Note:We DONT refresh the timer on purpose.
784 * Because almost always the next block will be opened.
785 */
786static void prb_close_block(struct tpacket_kbdq_core *pkc1,
787 struct tpacket_block_desc *pbd1,
788 struct packet_sock *po, unsigned int stat)
789{
790 __u32 status = TP_STATUS_USER | stat;
791
792 struct tpacket3_hdr *last_pkt;
793 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
794 struct sock *sk = &po->sk;
795
796 if (po->stats.stats3.tp_drops)
797 status |= TP_STATUS_LOSING;
798
799 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
800 last_pkt->tp_next_offset = 0;
801
802 /* Get the ts of the last pkt */
803 if (BLOCK_NUM_PKTS(pbd1)) {
804 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
805 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
806 } else {
807 /* Ok, we tmo'd - so get the current time.
808 *
809 * It shouldn't really happen as we don't close empty
810 * blocks. See prb_retire_rx_blk_timer_expired().
811 */
812 struct timespec ts;
813 getnstimeofday(&ts);
814 h1->ts_last_pkt.ts_sec = ts.tv_sec;
815 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
816 }
817
818 smp_wmb();
819
820 /* Flush the block */
821 prb_flush_block(pkc1, pbd1, status);
822
823 sk->sk_data_ready(sk);
824
825 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
826}
827
828static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
829{
830 pkc->reset_pending_on_curr_blk = 0;
831}
832
833/*
834 * Side effect of opening a block:
835 *
836 * 1) prb_queue is thawed.
837 * 2) retire_blk_timer is refreshed.
838 *
839 */
840static void prb_open_block(struct tpacket_kbdq_core *pkc1,
841 struct tpacket_block_desc *pbd1)
842{
843 struct timespec ts;
844 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
845
846 smp_rmb();
847
848 /* We could have just memset this but we will lose the
849 * flexibility of making the priv area sticky
850 */
851
852 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
853 BLOCK_NUM_PKTS(pbd1) = 0;
854 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
855
856 getnstimeofday(&ts);
857
858 h1->ts_first_pkt.ts_sec = ts.tv_sec;
859 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
860
861 pkc1->pkblk_start = (char *)pbd1;
862 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
863
864 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
865 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
866
867 pbd1->version = pkc1->version;
868 pkc1->prev = pkc1->nxt_offset;
869 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
870
871 prb_thaw_queue(pkc1);
872 _prb_refresh_rx_retire_blk_timer(pkc1);
873
874 smp_wmb();
875}
876
877/*
878 * Queue freeze logic:
879 * 1) Assume tp_block_nr = 8 blocks.
880 * 2) At time 't0', user opens Rx ring.
881 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
882 * 4) user-space is either sleeping or processing block '0'.
883 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
884 * it will close block-7,loop around and try to fill block '0'.
885 * call-flow:
886 * __packet_lookup_frame_in_block
887 * prb_retire_current_block()
888 * prb_dispatch_next_block()
889 * |->(BLOCK_STATUS == USER) evaluates to true
890 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
891 * 6) Now there are two cases:
892 * 6.1) Link goes idle right after the queue is frozen.
893 * But remember, the last open_block() refreshed the timer.
894 * When this timer expires,it will refresh itself so that we can
895 * re-open block-0 in near future.
896 * 6.2) Link is busy and keeps on receiving packets. This is a simple
897 * case and __packet_lookup_frame_in_block will check if block-0
898 * is free and can now be re-used.
899 */
900static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
901 struct packet_sock *po)
902{
903 pkc->reset_pending_on_curr_blk = 1;
904 po->stats.stats3.tp_freeze_q_cnt++;
905}
906
907#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
908
909/*
910 * If the next block is free then we will dispatch it
911 * and return a good offset.
912 * Else, we will freeze the queue.
913 * So, caller must check the return value.
914 */
915static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
916 struct packet_sock *po)
917{
918 struct tpacket_block_desc *pbd;
919
920 smp_rmb();
921
922 /* 1. Get current block num */
923 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
924
925 /* 2. If this block is currently in_use then freeze the queue */
926 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
927 prb_freeze_queue(pkc, po);
928 return NULL;
929 }
930
931 /*
932 * 3.
933 * open this block and return the offset where the first packet
934 * needs to get stored.
935 */
936 prb_open_block(pkc, pbd);
937 return (void *)pkc->nxt_offset;
938}
939
940static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
941 struct packet_sock *po, unsigned int status)
942{
943 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
944
945 /* retire/close the current block */
946 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
947 /*
948 * Plug the case where copy_bits() is in progress on
949 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
950 * have space to copy the pkt in the current block and
951 * called prb_retire_current_block()
952 *
953 * We don't need to worry about the TMO case because
954 * the timer-handler already handled this case.
955 */
956 if (!(status & TP_STATUS_BLK_TMO)) {
957 while (atomic_read(&pkc->blk_fill_in_prog)) {
958 /* Waiting for skb_copy_bits to finish... */
959 cpu_relax();
960 }
961 }
962 prb_close_block(pkc, pbd, po, status);
963 return;
964 }
965}
966
967static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
968 struct tpacket_block_desc *pbd)
969{
970 return TP_STATUS_USER & BLOCK_STATUS(pbd);
971}
972
973static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
974{
975 return pkc->reset_pending_on_curr_blk;
976}
977
978static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
979{
980 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
981 atomic_dec(&pkc->blk_fill_in_prog);
982}
983
984static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
985 struct tpacket3_hdr *ppd)
986{
987 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
988}
989
990static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
991 struct tpacket3_hdr *ppd)
992{
993 ppd->hv1.tp_rxhash = 0;
994}
995
996static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
997 struct tpacket3_hdr *ppd)
998{
999 if (skb_vlan_tag_present(pkc->skb)) {
1000 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1001 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1002 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1003 } else {
1004 ppd->hv1.tp_vlan_tci = 0;
1005 ppd->hv1.tp_vlan_tpid = 0;
1006 ppd->tp_status = TP_STATUS_AVAILABLE;
1007 }
1008}
1009
1010static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1011 struct tpacket3_hdr *ppd)
1012{
1013 ppd->hv1.tp_padding = 0;
1014 prb_fill_vlan_info(pkc, ppd);
1015
1016 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1017 prb_fill_rxhash(pkc, ppd);
1018 else
1019 prb_clear_rxhash(pkc, ppd);
1020}
1021
1022static void prb_fill_curr_block(char *curr,
1023 struct tpacket_kbdq_core *pkc,
1024 struct tpacket_block_desc *pbd,
1025 unsigned int len)
1026{
1027 struct tpacket3_hdr *ppd;
1028
1029 ppd = (struct tpacket3_hdr *)curr;
1030 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1031 pkc->prev = curr;
1032 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1033 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1034 BLOCK_NUM_PKTS(pbd) += 1;
1035 atomic_inc(&pkc->blk_fill_in_prog);
1036 prb_run_all_ft_ops(pkc, ppd);
1037}
1038
1039/* Assumes caller has the sk->rx_queue.lock */
1040static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1041 struct sk_buff *skb,
1042 int status,
1043 unsigned int len
1044 )
1045{
1046 struct tpacket_kbdq_core *pkc;
1047 struct tpacket_block_desc *pbd;
1048 char *curr, *end;
1049
1050 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1051 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1052
1053 /* Queue is frozen when user space is lagging behind */
1054 if (prb_queue_frozen(pkc)) {
1055 /*
1056 * Check if that last block which caused the queue to freeze,
1057 * is still in_use by user-space.
1058 */
1059 if (prb_curr_blk_in_use(pkc, pbd)) {
1060 /* Can't record this packet */
1061 return NULL;
1062 } else {
1063 /*
1064 * Ok, the block was released by user-space.
1065 * Now let's open that block.
1066 * opening a block also thaws the queue.
1067 * Thawing is a side effect.
1068 */
1069 prb_open_block(pkc, pbd);
1070 }
1071 }
1072
1073 smp_mb();
1074 curr = pkc->nxt_offset;
1075 pkc->skb = skb;
1076 end = (char *)pbd + pkc->kblk_size;
1077
1078 /* first try the current block */
1079 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1080 prb_fill_curr_block(curr, pkc, pbd, len);
1081 return (void *)curr;
1082 }
1083
1084 /* Ok, close the current block */
1085 prb_retire_current_block(pkc, po, 0);
1086
1087 /* Now, try to dispatch the next block */
1088 curr = (char *)prb_dispatch_next_block(pkc, po);
1089 if (curr) {
1090 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1091 prb_fill_curr_block(curr, pkc, pbd, len);
1092 return (void *)curr;
1093 }
1094
1095 /*
1096 * No free blocks are available.user_space hasn't caught up yet.
1097 * Queue was just frozen and now this packet will get dropped.
1098 */
1099 return NULL;
1100}
1101
1102static void *packet_current_rx_frame(struct packet_sock *po,
1103 struct sk_buff *skb,
1104 int status, unsigned int len)
1105{
1106 char *curr = NULL;
1107 switch (po->tp_version) {
1108 case TPACKET_V1:
1109 case TPACKET_V2:
1110 curr = packet_lookup_frame(po, &po->rx_ring,
1111 po->rx_ring.head, status);
1112 return curr;
1113 case TPACKET_V3:
1114 return __packet_lookup_frame_in_block(po, skb, status, len);
1115 default:
1116 WARN(1, "TPACKET version not supported\n");
1117 BUG();
1118 return NULL;
1119 }
1120}
1121
1122static void *prb_lookup_block(struct packet_sock *po,
1123 struct packet_ring_buffer *rb,
1124 unsigned int idx,
1125 int status)
1126{
1127 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1128 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1129
1130 if (status != BLOCK_STATUS(pbd))
1131 return NULL;
1132 return pbd;
1133}
1134
1135static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1136{
1137 unsigned int prev;
1138 if (rb->prb_bdqc.kactive_blk_num)
1139 prev = rb->prb_bdqc.kactive_blk_num-1;
1140 else
1141 prev = rb->prb_bdqc.knum_blocks-1;
1142 return prev;
1143}
1144
1145/* Assumes caller has held the rx_queue.lock */
1146static void *__prb_previous_block(struct packet_sock *po,
1147 struct packet_ring_buffer *rb,
1148 int status)
1149{
1150 unsigned int previous = prb_previous_blk_num(rb);
1151 return prb_lookup_block(po, rb, previous, status);
1152}
1153
1154static void *packet_previous_rx_frame(struct packet_sock *po,
1155 struct packet_ring_buffer *rb,
1156 int status)
1157{
1158 if (po->tp_version <= TPACKET_V2)
1159 return packet_previous_frame(po, rb, status);
1160
1161 return __prb_previous_block(po, rb, status);
1162}
1163
1164static void packet_increment_rx_head(struct packet_sock *po,
1165 struct packet_ring_buffer *rb)
1166{
1167 switch (po->tp_version) {
1168 case TPACKET_V1:
1169 case TPACKET_V2:
1170 return packet_increment_head(rb);
1171 case TPACKET_V3:
1172 default:
1173 WARN(1, "TPACKET version not supported.\n");
1174 BUG();
1175 return;
1176 }
1177}
1178
1179static void *packet_previous_frame(struct packet_sock *po,
1180 struct packet_ring_buffer *rb,
1181 int status)
1182{
1183 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1184 return packet_lookup_frame(po, rb, previous, status);
1185}
1186
1187static void packet_increment_head(struct packet_ring_buffer *buff)
1188{
1189 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1190}
1191
1192static void packet_inc_pending(struct packet_ring_buffer *rb)
1193{
1194 this_cpu_inc(*rb->pending_refcnt);
1195}
1196
1197static void packet_dec_pending(struct packet_ring_buffer *rb)
1198{
1199 this_cpu_dec(*rb->pending_refcnt);
1200}
1201
1202static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1203{
1204 unsigned int refcnt = 0;
1205 int cpu;
1206
1207 /* We don't use pending refcount in rx_ring. */
1208 if (rb->pending_refcnt == NULL)
1209 return 0;
1210
1211 for_each_possible_cpu(cpu)
1212 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1213
1214 return refcnt;
1215}
1216
1217static int packet_alloc_pending(struct packet_sock *po)
1218{
1219 po->rx_ring.pending_refcnt = NULL;
1220
1221 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1222 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1223 return -ENOBUFS;
1224
1225 return 0;
1226}
1227
1228static void packet_free_pending(struct packet_sock *po)
1229{
1230 free_percpu(po->tx_ring.pending_refcnt);
1231}
1232
1233#define ROOM_POW_OFF 2
1234#define ROOM_NONE 0x0
1235#define ROOM_LOW 0x1
1236#define ROOM_NORMAL 0x2
1237
1238static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1239{
1240 int idx, len;
1241
1242 len = po->rx_ring.frame_max + 1;
1243 idx = po->rx_ring.head;
1244 if (pow_off)
1245 idx += len >> pow_off;
1246 if (idx >= len)
1247 idx -= len;
1248 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1249}
1250
1251static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1252{
1253 int idx, len;
1254
1255 len = po->rx_ring.prb_bdqc.knum_blocks;
1256 idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1257 if (pow_off)
1258 idx += len >> pow_off;
1259 if (idx >= len)
1260 idx -= len;
1261 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1262}
1263
1264static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1265{
1266 struct sock *sk = &po->sk;
1267 int ret = ROOM_NONE;
1268
1269 if (po->prot_hook.func != tpacket_rcv) {
1270 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1271 - (skb ? skb->truesize : 0);
1272 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1273 return ROOM_NORMAL;
1274 else if (avail > 0)
1275 return ROOM_LOW;
1276 else
1277 return ROOM_NONE;
1278 }
1279
1280 if (po->tp_version == TPACKET_V3) {
1281 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1282 ret = ROOM_NORMAL;
1283 else if (__tpacket_v3_has_room(po, 0))
1284 ret = ROOM_LOW;
1285 } else {
1286 if (__tpacket_has_room(po, ROOM_POW_OFF))
1287 ret = ROOM_NORMAL;
1288 else if (__tpacket_has_room(po, 0))
1289 ret = ROOM_LOW;
1290 }
1291
1292 return ret;
1293}
1294
1295static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1296{
1297 int ret;
1298 bool has_room;
1299
1300 spin_lock_bh(&po->sk.sk_receive_queue.lock);
1301 ret = __packet_rcv_has_room(po, skb);
1302 has_room = ret == ROOM_NORMAL;
1303 if (po->pressure == has_room)
1304 po->pressure = !has_room;
1305 spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1306
1307 return ret;
1308}
1309
1310static void packet_sock_destruct(struct sock *sk)
1311{
1312 skb_queue_purge(&sk->sk_error_queue);
1313
1314 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1315 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1316
1317 if (!sock_flag(sk, SOCK_DEAD)) {
1318 pr_err("Attempt to release alive packet socket: %p\n", sk);
1319 return;
1320 }
1321
1322 sk_refcnt_debug_dec(sk);
1323}
1324
1325static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1326{
1327 u32 rxhash;
1328 int i, count = 0;
1329
1330 rxhash = skb_get_hash(skb);
1331 for (i = 0; i < ROLLOVER_HLEN; i++)
1332 if (po->rollover->history[i] == rxhash)
1333 count++;
1334
1335 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1336 return count > (ROLLOVER_HLEN >> 1);
1337}
1338
1339static unsigned int fanout_demux_hash(struct packet_fanout *f,
1340 struct sk_buff *skb,
1341 unsigned int num)
1342{
1343 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1344}
1345
1346static unsigned int fanout_demux_lb(struct packet_fanout *f,
1347 struct sk_buff *skb,
1348 unsigned int num)
1349{
1350 unsigned int val = atomic_inc_return(&f->rr_cur);
1351
1352 return val % num;
1353}
1354
1355static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1356 struct sk_buff *skb,
1357 unsigned int num)
1358{
1359 return smp_processor_id() % num;
1360}
1361
1362static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1363 struct sk_buff *skb,
1364 unsigned int num)
1365{
1366 return prandom_u32_max(num);
1367}
1368
1369static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1370 struct sk_buff *skb,
1371 unsigned int idx, bool try_self,
1372 unsigned int num)
1373{
1374 struct packet_sock *po, *po_next, *po_skip = NULL;
1375 unsigned int i, j, room = ROOM_NONE;
1376
1377 po = pkt_sk(f->arr[idx]);
1378
1379 if (try_self) {
1380 room = packet_rcv_has_room(po, skb);
1381 if (room == ROOM_NORMAL ||
1382 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1383 return idx;
1384 po_skip = po;
1385 }
1386
1387 i = j = min_t(int, po->rollover->sock, num - 1);
1388 do {
1389 po_next = pkt_sk(f->arr[i]);
1390 if (po_next != po_skip && !po_next->pressure &&
1391 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1392 if (i != j)
1393 po->rollover->sock = i;
1394 atomic_long_inc(&po->rollover->num);
1395 if (room == ROOM_LOW)
1396 atomic_long_inc(&po->rollover->num_huge);
1397 return i;
1398 }
1399
1400 if (++i == num)
1401 i = 0;
1402 } while (i != j);
1403
1404 atomic_long_inc(&po->rollover->num_failed);
1405 return idx;
1406}
1407
1408static unsigned int fanout_demux_qm(struct packet_fanout *f,
1409 struct sk_buff *skb,
1410 unsigned int num)
1411{
1412 return skb_get_queue_mapping(skb) % num;
1413}
1414
1415static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1416 struct sk_buff *skb,
1417 unsigned int num)
1418{
1419 struct bpf_prog *prog;
1420 unsigned int ret = 0;
1421
1422 rcu_read_lock();
1423 prog = rcu_dereference(f->bpf_prog);
1424 if (prog)
1425 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1426 rcu_read_unlock();
1427
1428 return ret;
1429}
1430
1431static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1432{
1433 return f->flags & (flag >> 8);
1434}
1435
1436static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1437 struct packet_type *pt, struct net_device *orig_dev)
1438{
1439 struct packet_fanout *f = pt->af_packet_priv;
1440 unsigned int num = READ_ONCE(f->num_members);
1441 struct net *net = read_pnet(&f->net);
1442 struct packet_sock *po;
1443 unsigned int idx;
1444
1445 if (!net_eq(dev_net(dev), net) || !num) {
1446 kfree_skb(skb);
1447 return 0;
1448 }
1449
1450 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1451 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1452 if (!skb)
1453 return 0;
1454 }
1455 switch (f->type) {
1456 case PACKET_FANOUT_HASH:
1457 default:
1458 idx = fanout_demux_hash(f, skb, num);
1459 break;
1460 case PACKET_FANOUT_LB:
1461 idx = fanout_demux_lb(f, skb, num);
1462 break;
1463 case PACKET_FANOUT_CPU:
1464 idx = fanout_demux_cpu(f, skb, num);
1465 break;
1466 case PACKET_FANOUT_RND:
1467 idx = fanout_demux_rnd(f, skb, num);
1468 break;
1469 case PACKET_FANOUT_QM:
1470 idx = fanout_demux_qm(f, skb, num);
1471 break;
1472 case PACKET_FANOUT_ROLLOVER:
1473 idx = fanout_demux_rollover(f, skb, 0, false, num);
1474 break;
1475 case PACKET_FANOUT_CBPF:
1476 case PACKET_FANOUT_EBPF:
1477 idx = fanout_demux_bpf(f, skb, num);
1478 break;
1479 }
1480
1481 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1482 idx = fanout_demux_rollover(f, skb, idx, true, num);
1483
1484 po = pkt_sk(f->arr[idx]);
1485 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1486}
1487
1488DEFINE_MUTEX(fanout_mutex);
1489EXPORT_SYMBOL_GPL(fanout_mutex);
1490static LIST_HEAD(fanout_list);
1491
1492static void __fanout_link(struct sock *sk, struct packet_sock *po)
1493{
1494 struct packet_fanout *f = po->fanout;
1495
1496 spin_lock(&f->lock);
1497 f->arr[f->num_members] = sk;
1498 smp_wmb();
1499 f->num_members++;
1500 if (f->num_members == 1)
1501 dev_add_pack(&f->prot_hook);
1502 spin_unlock(&f->lock);
1503}
1504
1505static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1506{
1507 struct packet_fanout *f = po->fanout;
1508 int i;
1509
1510 spin_lock(&f->lock);
1511 for (i = 0; i < f->num_members; i++) {
1512 if (f->arr[i] == sk)
1513 break;
1514 }
1515 BUG_ON(i >= f->num_members);
1516 f->arr[i] = f->arr[f->num_members - 1];
1517 f->num_members--;
1518 if (f->num_members == 0)
1519 __dev_remove_pack(&f->prot_hook);
1520 spin_unlock(&f->lock);
1521}
1522
1523static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1524{
1525 if (sk->sk_family != PF_PACKET)
1526 return false;
1527
1528 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1529}
1530
1531static void fanout_init_data(struct packet_fanout *f)
1532{
1533 switch (f->type) {
1534 case PACKET_FANOUT_LB:
1535 atomic_set(&f->rr_cur, 0);
1536 break;
1537 case PACKET_FANOUT_CBPF:
1538 case PACKET_FANOUT_EBPF:
1539 RCU_INIT_POINTER(f->bpf_prog, NULL);
1540 break;
1541 }
1542}
1543
1544static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1545{
1546 struct bpf_prog *old;
1547
1548 spin_lock(&f->lock);
1549 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1550 rcu_assign_pointer(f->bpf_prog, new);
1551 spin_unlock(&f->lock);
1552
1553 if (old) {
1554 synchronize_net();
1555 bpf_prog_destroy(old);
1556 }
1557}
1558
1559static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1560 unsigned int len)
1561{
1562 struct bpf_prog *new;
1563 struct sock_fprog fprog;
1564 int ret;
1565
1566 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1567 return -EPERM;
1568 if (len != sizeof(fprog))
1569 return -EINVAL;
1570 if (copy_from_user(&fprog, data, len))
1571 return -EFAULT;
1572
1573 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1574 if (ret)
1575 return ret;
1576
1577 __fanout_set_data_bpf(po->fanout, new);
1578 return 0;
1579}
1580
1581static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1582 unsigned int len)
1583{
1584 struct bpf_prog *new;
1585 u32 fd;
1586
1587 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1588 return -EPERM;
1589 if (len != sizeof(fd))
1590 return -EINVAL;
1591 if (copy_from_user(&fd, data, len))
1592 return -EFAULT;
1593
1594 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1595 if (IS_ERR(new))
1596 return PTR_ERR(new);
1597
1598 __fanout_set_data_bpf(po->fanout, new);
1599 return 0;
1600}
1601
1602static int fanout_set_data(struct packet_sock *po, char __user *data,
1603 unsigned int len)
1604{
1605 switch (po->fanout->type) {
1606 case PACKET_FANOUT_CBPF:
1607 return fanout_set_data_cbpf(po, data, len);
1608 case PACKET_FANOUT_EBPF:
1609 return fanout_set_data_ebpf(po, data, len);
1610 default:
1611 return -EINVAL;
1612 };
1613}
1614
1615static void fanout_release_data(struct packet_fanout *f)
1616{
1617 switch (f->type) {
1618 case PACKET_FANOUT_CBPF:
1619 case PACKET_FANOUT_EBPF:
1620 __fanout_set_data_bpf(f, NULL);
1621 };
1622}
1623
1624static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1625{
1626 struct packet_rollover *rollover = NULL;
1627 struct packet_sock *po = pkt_sk(sk);
1628 struct packet_fanout *f, *match;
1629 u8 type = type_flags & 0xff;
1630 u8 flags = type_flags >> 8;
1631 int err;
1632
1633 switch (type) {
1634 case PACKET_FANOUT_ROLLOVER:
1635 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1636 return -EINVAL;
1637 case PACKET_FANOUT_HASH:
1638 case PACKET_FANOUT_LB:
1639 case PACKET_FANOUT_CPU:
1640 case PACKET_FANOUT_RND:
1641 case PACKET_FANOUT_QM:
1642 case PACKET_FANOUT_CBPF:
1643 case PACKET_FANOUT_EBPF:
1644 break;
1645 default:
1646 return -EINVAL;
1647 }
1648
1649 mutex_lock(&fanout_mutex);
1650
1651 err = -EINVAL;
1652 if (!po->running)
1653 goto out;
1654
1655 err = -EALREADY;
1656 if (po->fanout)
1657 goto out;
1658
1659 if (type == PACKET_FANOUT_ROLLOVER ||
1660 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1661 err = -ENOMEM;
1662 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1663 if (!rollover)
1664 goto out;
1665 atomic_long_set(&rollover->num, 0);
1666 atomic_long_set(&rollover->num_huge, 0);
1667 atomic_long_set(&rollover->num_failed, 0);
1668 po->rollover = rollover;
1669 }
1670
1671 match = NULL;
1672 list_for_each_entry(f, &fanout_list, list) {
1673 if (f->id == id &&
1674 read_pnet(&f->net) == sock_net(sk)) {
1675 match = f;
1676 break;
1677 }
1678 }
1679 err = -EINVAL;
1680 if (match && match->flags != flags)
1681 goto out;
1682 if (!match) {
1683 err = -ENOMEM;
1684 match = kzalloc(sizeof(*match), GFP_KERNEL);
1685 if (!match)
1686 goto out;
1687 write_pnet(&match->net, sock_net(sk));
1688 match->id = id;
1689 match->type = type;
1690 match->flags = flags;
1691 INIT_LIST_HEAD(&match->list);
1692 spin_lock_init(&match->lock);
1693 atomic_set(&match->sk_ref, 0);
1694 fanout_init_data(match);
1695 match->prot_hook.type = po->prot_hook.type;
1696 match->prot_hook.dev = po->prot_hook.dev;
1697 match->prot_hook.func = packet_rcv_fanout;
1698 match->prot_hook.af_packet_priv = match;
1699 match->prot_hook.id_match = match_fanout_group;
1700 list_add(&match->list, &fanout_list);
1701 }
1702 err = -EINVAL;
1703 if (match->type == type &&
1704 match->prot_hook.type == po->prot_hook.type &&
1705 match->prot_hook.dev == po->prot_hook.dev) {
1706 err = -ENOSPC;
1707 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1708 __dev_remove_pack(&po->prot_hook);
1709 po->fanout = match;
1710 atomic_inc(&match->sk_ref);
1711 __fanout_link(sk, po);
1712 err = 0;
1713 }
1714 }
1715out:
1716 if (err && rollover) {
1717 kfree(rollover);
1718 po->rollover = NULL;
1719 }
1720 mutex_unlock(&fanout_mutex);
1721 return err;
1722}
1723
1724/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1725 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1726 * It is the responsibility of the caller to call fanout_release_data() and
1727 * free the returned packet_fanout (after synchronize_net())
1728 */
1729static struct packet_fanout *fanout_release(struct sock *sk)
1730{
1731 struct packet_sock *po = pkt_sk(sk);
1732 struct packet_fanout *f;
1733
1734 mutex_lock(&fanout_mutex);
1735 f = po->fanout;
1736 if (f) {
1737 po->fanout = NULL;
1738
1739 if (atomic_dec_and_test(&f->sk_ref))
1740 list_del(&f->list);
1741 else
1742 f = NULL;
1743
1744 if (po->rollover)
1745 kfree_rcu(po->rollover, rcu);
1746 }
1747 mutex_unlock(&fanout_mutex);
1748
1749 return f;
1750}
1751
1752static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1753 struct sk_buff *skb)
1754{
1755 /* Earlier code assumed this would be a VLAN pkt, double-check
1756 * this now that we have the actual packet in hand. We can only
1757 * do this check on Ethernet devices.
1758 */
1759 if (unlikely(dev->type != ARPHRD_ETHER))
1760 return false;
1761
1762 skb_reset_mac_header(skb);
1763 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1764}
1765
1766static const struct proto_ops packet_ops;
1767
1768static const struct proto_ops packet_ops_spkt;
1769
1770static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1771 struct packet_type *pt, struct net_device *orig_dev)
1772{
1773 struct sock *sk;
1774 struct sockaddr_pkt *spkt;
1775
1776 /*
1777 * When we registered the protocol we saved the socket in the data
1778 * field for just this event.
1779 */
1780
1781 sk = pt->af_packet_priv;
1782
1783 /*
1784 * Yank back the headers [hope the device set this
1785 * right or kerboom...]
1786 *
1787 * Incoming packets have ll header pulled,
1788 * push it back.
1789 *
1790 * For outgoing ones skb->data == skb_mac_header(skb)
1791 * so that this procedure is noop.
1792 */
1793
1794 if (skb->pkt_type == PACKET_LOOPBACK)
1795 goto out;
1796
1797 if (!net_eq(dev_net(dev), sock_net(sk)))
1798 goto out;
1799
1800 skb = skb_share_check(skb, GFP_ATOMIC);
1801 if (skb == NULL)
1802 goto oom;
1803
1804 /* drop any routing info */
1805 skb_dst_drop(skb);
1806
1807 /* drop conntrack reference */
1808 nf_reset(skb);
1809
1810 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1811
1812 skb_push(skb, skb->data - skb_mac_header(skb));
1813
1814 /*
1815 * The SOCK_PACKET socket receives _all_ frames.
1816 */
1817
1818 spkt->spkt_family = dev->type;
1819 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1820 spkt->spkt_protocol = skb->protocol;
1821
1822 /*
1823 * Charge the memory to the socket. This is done specifically
1824 * to prevent sockets using all the memory up.
1825 */
1826
1827 if (sock_queue_rcv_skb(sk, skb) == 0)
1828 return 0;
1829
1830out:
1831 kfree_skb(skb);
1832oom:
1833 return 0;
1834}
1835
1836
1837/*
1838 * Output a raw packet to a device layer. This bypasses all the other
1839 * protocol layers and you must therefore supply it with a complete frame
1840 */
1841
1842static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1843 size_t len)
1844{
1845 struct sock *sk = sock->sk;
1846 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1847 struct sk_buff *skb = NULL;
1848 struct net_device *dev;
1849 struct sockcm_cookie sockc;
1850 __be16 proto = 0;
1851 int err;
1852 int extra_len = 0;
1853
1854 /*
1855 * Get and verify the address.
1856 */
1857
1858 if (saddr) {
1859 if (msg->msg_namelen < sizeof(struct sockaddr))
1860 return -EINVAL;
1861 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1862 proto = saddr->spkt_protocol;
1863 } else
1864 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1865
1866 /*
1867 * Find the device first to size check it
1868 */
1869
1870 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1871retry:
1872 rcu_read_lock();
1873 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1874 err = -ENODEV;
1875 if (dev == NULL)
1876 goto out_unlock;
1877
1878 err = -ENETDOWN;
1879 if (!(dev->flags & IFF_UP))
1880 goto out_unlock;
1881
1882 /*
1883 * You may not queue a frame bigger than the mtu. This is the lowest level
1884 * raw protocol and you must do your own fragmentation at this level.
1885 */
1886
1887 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1888 if (!netif_supports_nofcs(dev)) {
1889 err = -EPROTONOSUPPORT;
1890 goto out_unlock;
1891 }
1892 extra_len = 4; /* We're doing our own CRC */
1893 }
1894
1895 err = -EMSGSIZE;
1896 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1897 goto out_unlock;
1898
1899 if (!skb) {
1900 size_t reserved = LL_RESERVED_SPACE(dev);
1901 int tlen = dev->needed_tailroom;
1902 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1903
1904 rcu_read_unlock();
1905 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1906 if (skb == NULL)
1907 return -ENOBUFS;
1908 /* FIXME: Save some space for broken drivers that write a hard
1909 * header at transmission time by themselves. PPP is the notable
1910 * one here. This should really be fixed at the driver level.
1911 */
1912 skb_reserve(skb, reserved);
1913 skb_reset_network_header(skb);
1914
1915 /* Try to align data part correctly */
1916 if (hhlen) {
1917 skb->data -= hhlen;
1918 skb->tail -= hhlen;
1919 if (len < hhlen)
1920 skb_reset_network_header(skb);
1921 }
1922 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1923 if (err)
1924 goto out_free;
1925 goto retry;
1926 }
1927
1928 if (!dev_validate_header(dev, skb->data, len)) {
1929 err = -EINVAL;
1930 goto out_unlock;
1931 }
1932 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1933 !packet_extra_vlan_len_allowed(dev, skb)) {
1934 err = -EMSGSIZE;
1935 goto out_unlock;
1936 }
1937
1938 sockc.tsflags = sk->sk_tsflags;
1939 if (msg->msg_controllen) {
1940 err = sock_cmsg_send(sk, msg, &sockc);
1941 if (unlikely(err))
1942 goto out_unlock;
1943 }
1944
1945 skb->protocol = proto;
1946 skb->dev = dev;
1947 skb->priority = sk->sk_priority;
1948 skb->mark = sk->sk_mark;
1949
1950 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
1951
1952 if (unlikely(extra_len == 4))
1953 skb->no_fcs = 1;
1954
1955 skb_probe_transport_header(skb, 0);
1956
1957 dev_queue_xmit(skb);
1958 rcu_read_unlock();
1959 return len;
1960
1961out_unlock:
1962 rcu_read_unlock();
1963out_free:
1964 kfree_skb(skb);
1965 return err;
1966}
1967
1968static unsigned int run_filter(struct sk_buff *skb,
1969 const struct sock *sk,
1970 unsigned int res)
1971{
1972 struct sk_filter *filter;
1973
1974 rcu_read_lock();
1975 filter = rcu_dereference(sk->sk_filter);
1976 if (filter != NULL)
1977 res = bpf_prog_run_clear_cb(filter->prog, skb);
1978 rcu_read_unlock();
1979
1980 return res;
1981}
1982
1983static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
1984 size_t *len)
1985{
1986 struct virtio_net_hdr vnet_hdr;
1987
1988 if (*len < sizeof(vnet_hdr))
1989 return -EINVAL;
1990 *len -= sizeof(vnet_hdr);
1991
1992 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true))
1993 return -EINVAL;
1994
1995 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
1996}
1997
1998/*
1999 * This function makes lazy skb cloning in hope that most of packets
2000 * are discarded by BPF.
2001 *
2002 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2003 * and skb->cb are mangled. It works because (and until) packets
2004 * falling here are owned by current CPU. Output packets are cloned
2005 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2006 * sequencially, so that if we return skb to original state on exit,
2007 * we will not harm anyone.
2008 */
2009
2010static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2011 struct packet_type *pt, struct net_device *orig_dev)
2012{
2013 struct sock *sk;
2014 struct sockaddr_ll *sll;
2015 struct packet_sock *po;
2016 u8 *skb_head = skb->data;
2017 int skb_len = skb->len;
2018 unsigned int snaplen, res;
2019 bool is_drop_n_account = false;
2020
2021 if (skb->pkt_type == PACKET_LOOPBACK)
2022 goto drop;
2023
2024 sk = pt->af_packet_priv;
2025 po = pkt_sk(sk);
2026
2027 if (!net_eq(dev_net(dev), sock_net(sk)))
2028 goto drop;
2029
2030 skb->dev = dev;
2031
2032 if (dev->header_ops) {
2033 /* The device has an explicit notion of ll header,
2034 * exported to higher levels.
2035 *
2036 * Otherwise, the device hides details of its frame
2037 * structure, so that corresponding packet head is
2038 * never delivered to user.
2039 */
2040 if (sk->sk_type != SOCK_DGRAM)
2041 skb_push(skb, skb->data - skb_mac_header(skb));
2042 else if (skb->pkt_type == PACKET_OUTGOING) {
2043 /* Special case: outgoing packets have ll header at head */
2044 skb_pull(skb, skb_network_offset(skb));
2045 }
2046 }
2047
2048 snaplen = skb->len;
2049
2050 res = run_filter(skb, sk, snaplen);
2051 if (!res)
2052 goto drop_n_restore;
2053 if (snaplen > res)
2054 snaplen = res;
2055
2056 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2057 goto drop_n_acct;
2058
2059 if (skb_shared(skb)) {
2060 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2061 if (nskb == NULL)
2062 goto drop_n_acct;
2063
2064 if (skb_head != skb->data) {
2065 skb->data = skb_head;
2066 skb->len = skb_len;
2067 }
2068 consume_skb(skb);
2069 skb = nskb;
2070 }
2071
2072 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2073
2074 sll = &PACKET_SKB_CB(skb)->sa.ll;
2075 sll->sll_hatype = dev->type;
2076 sll->sll_pkttype = skb->pkt_type;
2077 if (unlikely(po->origdev))
2078 sll->sll_ifindex = orig_dev->ifindex;
2079 else
2080 sll->sll_ifindex = dev->ifindex;
2081
2082 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2083
2084 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2085 * Use their space for storing the original skb length.
2086 */
2087 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2088
2089 if (pskb_trim(skb, snaplen))
2090 goto drop_n_acct;
2091
2092 skb_set_owner_r(skb, sk);
2093 skb->dev = NULL;
2094 skb_dst_drop(skb);
2095
2096 /* drop conntrack reference */
2097 nf_reset(skb);
2098
2099 spin_lock(&sk->sk_receive_queue.lock);
2100 po->stats.stats1.tp_packets++;
2101 sock_skb_set_dropcount(sk, skb);
2102 __skb_queue_tail(&sk->sk_receive_queue, skb);
2103 spin_unlock(&sk->sk_receive_queue.lock);
2104 sk->sk_data_ready(sk);
2105 return 0;
2106
2107drop_n_acct:
2108 is_drop_n_account = true;
2109 spin_lock(&sk->sk_receive_queue.lock);
2110 po->stats.stats1.tp_drops++;
2111 atomic_inc(&sk->sk_drops);
2112 spin_unlock(&sk->sk_receive_queue.lock);
2113
2114drop_n_restore:
2115 if (skb_head != skb->data && skb_shared(skb)) {
2116 skb->data = skb_head;
2117 skb->len = skb_len;
2118 }
2119drop:
2120 if (!is_drop_n_account)
2121 consume_skb(skb);
2122 else
2123 kfree_skb(skb);
2124 return 0;
2125}
2126
2127static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2128 struct packet_type *pt, struct net_device *orig_dev)
2129{
2130 struct sock *sk;
2131 struct packet_sock *po;
2132 struct sockaddr_ll *sll;
2133 union tpacket_uhdr h;
2134 u8 *skb_head = skb->data;
2135 int skb_len = skb->len;
2136 unsigned int snaplen, res;
2137 unsigned long status = TP_STATUS_USER;
2138 unsigned short macoff, netoff, hdrlen;
2139 struct sk_buff *copy_skb = NULL;
2140 struct timespec ts;
2141 __u32 ts_status;
2142 bool is_drop_n_account = false;
2143
2144 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2145 * We may add members to them until current aligned size without forcing
2146 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2147 */
2148 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2149 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2150
2151 if (skb->pkt_type == PACKET_LOOPBACK)
2152 goto drop;
2153
2154 sk = pt->af_packet_priv;
2155 po = pkt_sk(sk);
2156
2157 if (!net_eq(dev_net(dev), sock_net(sk)))
2158 goto drop;
2159
2160 if (dev->header_ops) {
2161 if (sk->sk_type != SOCK_DGRAM)
2162 skb_push(skb, skb->data - skb_mac_header(skb));
2163 else if (skb->pkt_type == PACKET_OUTGOING) {
2164 /* Special case: outgoing packets have ll header at head */
2165 skb_pull(skb, skb_network_offset(skb));
2166 }
2167 }
2168
2169 snaplen = skb->len;
2170
2171 res = run_filter(skb, sk, snaplen);
2172 if (!res)
2173 goto drop_n_restore;
2174
2175 if (skb->ip_summed == CHECKSUM_PARTIAL)
2176 status |= TP_STATUS_CSUMNOTREADY;
2177 else if (skb->pkt_type != PACKET_OUTGOING &&
2178 (skb->ip_summed == CHECKSUM_COMPLETE ||
2179 skb_csum_unnecessary(skb)))
2180 status |= TP_STATUS_CSUM_VALID;
2181
2182 if (snaplen > res)
2183 snaplen = res;
2184
2185 if (sk->sk_type == SOCK_DGRAM) {
2186 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2187 po->tp_reserve;
2188 } else {
2189 unsigned int maclen = skb_network_offset(skb);
2190 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2191 (maclen < 16 ? 16 : maclen)) +
2192 po->tp_reserve;
2193 if (po->has_vnet_hdr)
2194 netoff += sizeof(struct virtio_net_hdr);
2195 macoff = netoff - maclen;
2196 }
2197 if (po->tp_version <= TPACKET_V2) {
2198 if (macoff + snaplen > po->rx_ring.frame_size) {
2199 if (po->copy_thresh &&
2200 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2201 if (skb_shared(skb)) {
2202 copy_skb = skb_clone(skb, GFP_ATOMIC);
2203 } else {
2204 copy_skb = skb_get(skb);
2205 skb_head = skb->data;
2206 }
2207 if (copy_skb)
2208 skb_set_owner_r(copy_skb, sk);
2209 }
2210 snaplen = po->rx_ring.frame_size - macoff;
2211 if ((int)snaplen < 0)
2212 snaplen = 0;
2213 }
2214 } else if (unlikely(macoff + snaplen >
2215 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2216 u32 nval;
2217
2218 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2219 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2220 snaplen, nval, macoff);
2221 snaplen = nval;
2222 if (unlikely((int)snaplen < 0)) {
2223 snaplen = 0;
2224 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2225 }
2226 }
2227 spin_lock(&sk->sk_receive_queue.lock);
2228 h.raw = packet_current_rx_frame(po, skb,
2229 TP_STATUS_KERNEL, (macoff+snaplen));
2230 if (!h.raw)
2231 goto drop_n_account;
2232 if (po->tp_version <= TPACKET_V2) {
2233 packet_increment_rx_head(po, &po->rx_ring);
2234 /*
2235 * LOSING will be reported till you read the stats,
2236 * because it's COR - Clear On Read.
2237 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2238 * at packet level.
2239 */
2240 if (po->stats.stats1.tp_drops)
2241 status |= TP_STATUS_LOSING;
2242 }
2243 po->stats.stats1.tp_packets++;
2244 if (copy_skb) {
2245 status |= TP_STATUS_COPY;
2246 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2247 }
2248 spin_unlock(&sk->sk_receive_queue.lock);
2249
2250 if (po->has_vnet_hdr) {
2251 if (virtio_net_hdr_from_skb(skb, h.raw + macoff -
2252 sizeof(struct virtio_net_hdr),
2253 vio_le(), true)) {
2254 spin_lock(&sk->sk_receive_queue.lock);
2255 goto drop_n_account;
2256 }
2257 }
2258
2259 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2260
2261 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2262 getnstimeofday(&ts);
2263
2264 status |= ts_status;
2265
2266 switch (po->tp_version) {
2267 case TPACKET_V1:
2268 h.h1->tp_len = skb->len;
2269 h.h1->tp_snaplen = snaplen;
2270 h.h1->tp_mac = macoff;
2271 h.h1->tp_net = netoff;
2272 h.h1->tp_sec = ts.tv_sec;
2273 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2274 hdrlen = sizeof(*h.h1);
2275 break;
2276 case TPACKET_V2:
2277 h.h2->tp_len = skb->len;
2278 h.h2->tp_snaplen = snaplen;
2279 h.h2->tp_mac = macoff;
2280 h.h2->tp_net = netoff;
2281 h.h2->tp_sec = ts.tv_sec;
2282 h.h2->tp_nsec = ts.tv_nsec;
2283 if (skb_vlan_tag_present(skb)) {
2284 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2285 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2286 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2287 } else {
2288 h.h2->tp_vlan_tci = 0;
2289 h.h2->tp_vlan_tpid = 0;
2290 }
2291 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2292 hdrlen = sizeof(*h.h2);
2293 break;
2294 case TPACKET_V3:
2295 /* tp_nxt_offset,vlan are already populated above.
2296 * So DONT clear those fields here
2297 */
2298 h.h3->tp_status |= status;
2299 h.h3->tp_len = skb->len;
2300 h.h3->tp_snaplen = snaplen;
2301 h.h3->tp_mac = macoff;
2302 h.h3->tp_net = netoff;
2303 h.h3->tp_sec = ts.tv_sec;
2304 h.h3->tp_nsec = ts.tv_nsec;
2305 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2306 hdrlen = sizeof(*h.h3);
2307 break;
2308 default:
2309 BUG();
2310 }
2311
2312 sll = h.raw + TPACKET_ALIGN(hdrlen);
2313 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2314 sll->sll_family = AF_PACKET;
2315 sll->sll_hatype = dev->type;
2316 sll->sll_protocol = skb->protocol;
2317 sll->sll_pkttype = skb->pkt_type;
2318 if (unlikely(po->origdev))
2319 sll->sll_ifindex = orig_dev->ifindex;
2320 else
2321 sll->sll_ifindex = dev->ifindex;
2322
2323 smp_mb();
2324
2325#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2326 if (po->tp_version <= TPACKET_V2) {
2327 u8 *start, *end;
2328
2329 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2330 macoff + snaplen);
2331
2332 for (start = h.raw; start < end; start += PAGE_SIZE)
2333 flush_dcache_page(pgv_to_page(start));
2334 }
2335 smp_wmb();
2336#endif
2337
2338 if (po->tp_version <= TPACKET_V2) {
2339 __packet_set_status(po, h.raw, status);
2340 sk->sk_data_ready(sk);
2341 } else {
2342 prb_clear_blk_fill_status(&po->rx_ring);
2343 }
2344
2345drop_n_restore:
2346 if (skb_head != skb->data && skb_shared(skb)) {
2347 skb->data = skb_head;
2348 skb->len = skb_len;
2349 }
2350drop:
2351 if (!is_drop_n_account)
2352 consume_skb(skb);
2353 else
2354 kfree_skb(skb);
2355 return 0;
2356
2357drop_n_account:
2358 is_drop_n_account = true;
2359 po->stats.stats1.tp_drops++;
2360 spin_unlock(&sk->sk_receive_queue.lock);
2361
2362 sk->sk_data_ready(sk);
2363 kfree_skb(copy_skb);
2364 goto drop_n_restore;
2365}
2366
2367static void tpacket_destruct_skb(struct sk_buff *skb)
2368{
2369 struct packet_sock *po = pkt_sk(skb->sk);
2370
2371 if (likely(po->tx_ring.pg_vec)) {
2372 void *ph;
2373 __u32 ts;
2374
2375 ph = skb_shinfo(skb)->destructor_arg;
2376 packet_dec_pending(&po->tx_ring);
2377
2378 ts = __packet_set_timestamp(po, ph, skb);
2379 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2380 }
2381
2382 sock_wfree(skb);
2383}
2384
2385static void tpacket_set_protocol(const struct net_device *dev,
2386 struct sk_buff *skb)
2387{
2388 if (dev->type == ARPHRD_ETHER) {
2389 skb_reset_mac_header(skb);
2390 skb->protocol = eth_hdr(skb)->h_proto;
2391 }
2392}
2393
2394static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2395{
2396 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2397 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2398 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2399 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2400 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2401 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2402 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2403
2404 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2405 return -EINVAL;
2406
2407 return 0;
2408}
2409
2410static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2411 struct virtio_net_hdr *vnet_hdr)
2412{
2413 if (*len < sizeof(*vnet_hdr))
2414 return -EINVAL;
2415 *len -= sizeof(*vnet_hdr);
2416
2417 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2418 return -EFAULT;
2419
2420 return __packet_snd_vnet_parse(vnet_hdr, *len);
2421}
2422
2423static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2424 void *frame, struct net_device *dev, void *data, int tp_len,
2425 __be16 proto, unsigned char *addr, int hlen, int copylen,
2426 const struct sockcm_cookie *sockc)
2427{
2428 union tpacket_uhdr ph;
2429 int to_write, offset, len, nr_frags, len_max;
2430 struct socket *sock = po->sk.sk_socket;
2431 struct page *page;
2432 int err;
2433
2434 ph.raw = frame;
2435
2436 skb->protocol = proto;
2437 skb->dev = dev;
2438 skb->priority = po->sk.sk_priority;
2439 skb->mark = po->sk.sk_mark;
2440 sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);
2441 skb_shinfo(skb)->destructor_arg = ph.raw;
2442
2443 skb_reserve(skb, hlen);
2444 skb_reset_network_header(skb);
2445
2446 to_write = tp_len;
2447
2448 if (sock->type == SOCK_DGRAM) {
2449 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2450 NULL, tp_len);
2451 if (unlikely(err < 0))
2452 return -EINVAL;
2453 } else if (copylen) {
2454 int hdrlen = min_t(int, copylen, tp_len);
2455
2456 skb_push(skb, dev->hard_header_len);
2457 skb_put(skb, copylen - dev->hard_header_len);
2458 err = skb_store_bits(skb, 0, data, hdrlen);
2459 if (unlikely(err))
2460 return err;
2461 if (!dev_validate_header(dev, skb->data, hdrlen))
2462 return -EINVAL;
2463 if (!skb->protocol)
2464 tpacket_set_protocol(dev, skb);
2465
2466 data += hdrlen;
2467 to_write -= hdrlen;
2468 }
2469
2470 offset = offset_in_page(data);
2471 len_max = PAGE_SIZE - offset;
2472 len = ((to_write > len_max) ? len_max : to_write);
2473
2474 skb->data_len = to_write;
2475 skb->len += to_write;
2476 skb->truesize += to_write;
2477 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2478
2479 while (likely(to_write)) {
2480 nr_frags = skb_shinfo(skb)->nr_frags;
2481
2482 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2483 pr_err("Packet exceed the number of skb frags(%lu)\n",
2484 MAX_SKB_FRAGS);
2485 return -EFAULT;
2486 }
2487
2488 page = pgv_to_page(data);
2489 data += len;
2490 flush_dcache_page(page);
2491 get_page(page);
2492 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2493 to_write -= len;
2494 offset = 0;
2495 len_max = PAGE_SIZE;
2496 len = ((to_write > len_max) ? len_max : to_write);
2497 }
2498
2499 skb_probe_transport_header(skb, 0);
2500
2501 return tp_len;
2502}
2503
2504static int tpacket_parse_header(struct packet_sock *po, void *frame,
2505 int size_max, void **data)
2506{
2507 union tpacket_uhdr ph;
2508 int tp_len, off;
2509
2510 ph.raw = frame;
2511
2512 switch (po->tp_version) {
2513 case TPACKET_V2:
2514 tp_len = ph.h2->tp_len;
2515 break;
2516 default:
2517 tp_len = ph.h1->tp_len;
2518 break;
2519 }
2520 if (unlikely(tp_len > size_max)) {
2521 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2522 return -EMSGSIZE;
2523 }
2524
2525 if (unlikely(po->tp_tx_has_off)) {
2526 int off_min, off_max;
2527
2528 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2529 off_max = po->tx_ring.frame_size - tp_len;
2530 if (po->sk.sk_type == SOCK_DGRAM) {
2531 switch (po->tp_version) {
2532 case TPACKET_V2:
2533 off = ph.h2->tp_net;
2534 break;
2535 default:
2536 off = ph.h1->tp_net;
2537 break;
2538 }
2539 } else {
2540 switch (po->tp_version) {
2541 case TPACKET_V2:
2542 off = ph.h2->tp_mac;
2543 break;
2544 default:
2545 off = ph.h1->tp_mac;
2546 break;
2547 }
2548 }
2549 if (unlikely((off < off_min) || (off_max < off)))
2550 return -EINVAL;
2551 } else {
2552 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2553 }
2554
2555 *data = frame + off;
2556 return tp_len;
2557}
2558
2559static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2560{
2561 struct sk_buff *skb;
2562 struct net_device *dev;
2563 struct virtio_net_hdr *vnet_hdr = NULL;
2564 struct sockcm_cookie sockc;
2565 __be16 proto;
2566 int err, reserve = 0;
2567 void *ph;
2568 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2569 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2570 int tp_len, size_max;
2571 unsigned char *addr;
2572 void *data;
2573 int len_sum = 0;
2574 int status = TP_STATUS_AVAILABLE;
2575 int hlen, tlen, copylen = 0;
2576
2577 mutex_lock(&po->pg_vec_lock);
2578
2579 if (likely(saddr == NULL)) {
2580 dev = packet_cached_dev_get(po);
2581 proto = po->num;
2582 addr = NULL;
2583 } else {
2584 err = -EINVAL;
2585 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2586 goto out;
2587 if (msg->msg_namelen < (saddr->sll_halen
2588 + offsetof(struct sockaddr_ll,
2589 sll_addr)))
2590 goto out;
2591 proto = saddr->sll_protocol;
2592 addr = saddr->sll_addr;
2593 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2594 }
2595
2596 sockc.tsflags = po->sk.sk_tsflags;
2597 if (msg->msg_controllen) {
2598 err = sock_cmsg_send(&po->sk, msg, &sockc);
2599 if (unlikely(err))
2600 goto out;
2601 }
2602
2603 err = -ENXIO;
2604 if (unlikely(dev == NULL))
2605 goto out;
2606 err = -ENETDOWN;
2607 if (unlikely(!(dev->flags & IFF_UP)))
2608 goto out_put;
2609
2610 if (po->sk.sk_socket->type == SOCK_RAW)
2611 reserve = dev->hard_header_len;
2612 size_max = po->tx_ring.frame_size
2613 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2614
2615 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2616 size_max = dev->mtu + reserve + VLAN_HLEN;
2617
2618 do {
2619 ph = packet_current_frame(po, &po->tx_ring,
2620 TP_STATUS_SEND_REQUEST);
2621 if (unlikely(ph == NULL)) {
2622 if (need_wait && need_resched())
2623 schedule();
2624 continue;
2625 }
2626
2627 skb = NULL;
2628 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2629 if (tp_len < 0)
2630 goto tpacket_error;
2631
2632 status = TP_STATUS_SEND_REQUEST;
2633 hlen = LL_RESERVED_SPACE(dev);
2634 tlen = dev->needed_tailroom;
2635 if (po->has_vnet_hdr) {
2636 vnet_hdr = data;
2637 data += sizeof(*vnet_hdr);
2638 tp_len -= sizeof(*vnet_hdr);
2639 if (tp_len < 0 ||
2640 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2641 tp_len = -EINVAL;
2642 goto tpacket_error;
2643 }
2644 copylen = __virtio16_to_cpu(vio_le(),
2645 vnet_hdr->hdr_len);
2646 }
2647 copylen = max_t(int, copylen, dev->hard_header_len);
2648 skb = sock_alloc_send_skb(&po->sk,
2649 hlen + tlen + sizeof(struct sockaddr_ll) +
2650 (copylen - dev->hard_header_len),
2651 !need_wait, &err);
2652
2653 if (unlikely(skb == NULL)) {
2654 /* we assume the socket was initially writeable ... */
2655 if (likely(len_sum > 0))
2656 err = len_sum;
2657 goto out_status;
2658 }
2659 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2660 addr, hlen, copylen, &sockc);
2661 if (likely(tp_len >= 0) &&
2662 tp_len > dev->mtu + reserve &&
2663 !po->has_vnet_hdr &&
2664 !packet_extra_vlan_len_allowed(dev, skb))
2665 tp_len = -EMSGSIZE;
2666
2667 if (unlikely(tp_len < 0)) {
2668tpacket_error:
2669 if (po->tp_loss) {
2670 __packet_set_status(po, ph,
2671 TP_STATUS_AVAILABLE);
2672 packet_increment_head(&po->tx_ring);
2673 kfree_skb(skb);
2674 continue;
2675 } else {
2676 status = TP_STATUS_WRONG_FORMAT;
2677 err = tp_len;
2678 goto out_status;
2679 }
2680 }
2681
2682 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr,
2683 vio_le())) {
2684 tp_len = -EINVAL;
2685 goto tpacket_error;
2686 }
2687
2688 packet_pick_tx_queue(dev, skb);
2689
2690 skb->destructor = tpacket_destruct_skb;
2691 __packet_set_status(po, ph, TP_STATUS_SENDING);
2692 packet_inc_pending(&po->tx_ring);
2693
2694 status = TP_STATUS_SEND_REQUEST;
2695 err = po->xmit(skb);
2696 if (unlikely(err > 0)) {
2697 err = net_xmit_errno(err);
2698 if (err && __packet_get_status(po, ph) ==
2699 TP_STATUS_AVAILABLE) {
2700 /* skb was destructed already */
2701 skb = NULL;
2702 goto out_status;
2703 }
2704 /*
2705 * skb was dropped but not destructed yet;
2706 * let's treat it like congestion or err < 0
2707 */
2708 err = 0;
2709 }
2710 packet_increment_head(&po->tx_ring);
2711 len_sum += tp_len;
2712 } while (likely((ph != NULL) ||
2713 /* Note: packet_read_pending() might be slow if we have
2714 * to call it as it's per_cpu variable, but in fast-path
2715 * we already short-circuit the loop with the first
2716 * condition, and luckily don't have to go that path
2717 * anyway.
2718 */
2719 (need_wait && packet_read_pending(&po->tx_ring))));
2720
2721 err = len_sum;
2722 goto out_put;
2723
2724out_status:
2725 __packet_set_status(po, ph, status);
2726 kfree_skb(skb);
2727out_put:
2728 dev_put(dev);
2729out:
2730 mutex_unlock(&po->pg_vec_lock);
2731 return err;
2732}
2733
2734static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2735 size_t reserve, size_t len,
2736 size_t linear, int noblock,
2737 int *err)
2738{
2739 struct sk_buff *skb;
2740
2741 /* Under a page? Don't bother with paged skb. */
2742 if (prepad + len < PAGE_SIZE || !linear)
2743 linear = len;
2744
2745 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2746 err, 0);
2747 if (!skb)
2748 return NULL;
2749
2750 skb_reserve(skb, reserve);
2751 skb_put(skb, linear);
2752 skb->data_len = len - linear;
2753 skb->len += len - linear;
2754
2755 return skb;
2756}
2757
2758static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2759{
2760 struct sock *sk = sock->sk;
2761 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2762 struct sk_buff *skb;
2763 struct net_device *dev;
2764 __be16 proto;
2765 unsigned char *addr;
2766 int err, reserve = 0;
2767 struct sockcm_cookie sockc;
2768 struct virtio_net_hdr vnet_hdr = { 0 };
2769 int offset = 0;
2770 struct packet_sock *po = pkt_sk(sk);
2771 int hlen, tlen, linear;
2772 int extra_len = 0;
2773
2774 /*
2775 * Get and verify the address.
2776 */
2777
2778 if (likely(saddr == NULL)) {
2779 dev = packet_cached_dev_get(po);
2780 proto = po->num;
2781 addr = NULL;
2782 } else {
2783 err = -EINVAL;
2784 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2785 goto out;
2786 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2787 goto out;
2788 proto = saddr->sll_protocol;
2789 addr = saddr->sll_addr;
2790 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2791 }
2792
2793 err = -ENXIO;
2794 if (unlikely(dev == NULL))
2795 goto out_unlock;
2796 err = -ENETDOWN;
2797 if (unlikely(!(dev->flags & IFF_UP)))
2798 goto out_unlock;
2799
2800 sockc.tsflags = sk->sk_tsflags;
2801 sockc.mark = sk->sk_mark;
2802 if (msg->msg_controllen) {
2803 err = sock_cmsg_send(sk, msg, &sockc);
2804 if (unlikely(err))
2805 goto out_unlock;
2806 }
2807
2808 if (sock->type == SOCK_RAW)
2809 reserve = dev->hard_header_len;
2810 if (po->has_vnet_hdr) {
2811 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2812 if (err)
2813 goto out_unlock;
2814 }
2815
2816 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2817 if (!netif_supports_nofcs(dev)) {
2818 err = -EPROTONOSUPPORT;
2819 goto out_unlock;
2820 }
2821 extra_len = 4; /* We're doing our own CRC */
2822 }
2823
2824 err = -EMSGSIZE;
2825 if (!vnet_hdr.gso_type &&
2826 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2827 goto out_unlock;
2828
2829 err = -ENOBUFS;
2830 hlen = LL_RESERVED_SPACE(dev);
2831 tlen = dev->needed_tailroom;
2832 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2833 linear = max(linear, min_t(int, len, dev->hard_header_len));
2834 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2835 msg->msg_flags & MSG_DONTWAIT, &err);
2836 if (skb == NULL)
2837 goto out_unlock;
2838
2839 skb_set_network_header(skb, reserve);
2840
2841 err = -EINVAL;
2842 if (sock->type == SOCK_DGRAM) {
2843 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2844 if (unlikely(offset < 0))
2845 goto out_free;
2846 }
2847
2848 /* Returns -EFAULT on error */
2849 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2850 if (err)
2851 goto out_free;
2852
2853 if (sock->type == SOCK_RAW &&
2854 !dev_validate_header(dev, skb->data, len)) {
2855 err = -EINVAL;
2856 goto out_free;
2857 }
2858
2859 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
2860
2861 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2862 !packet_extra_vlan_len_allowed(dev, skb)) {
2863 err = -EMSGSIZE;
2864 goto out_free;
2865 }
2866
2867 skb->protocol = proto;
2868 skb->dev = dev;
2869 skb->priority = sk->sk_priority;
2870 skb->mark = sockc.mark;
2871
2872 packet_pick_tx_queue(dev, skb);
2873
2874 if (po->has_vnet_hdr) {
2875 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2876 if (err)
2877 goto out_free;
2878 len += sizeof(vnet_hdr);
2879 }
2880
2881 skb_probe_transport_header(skb, reserve);
2882
2883 if (unlikely(extra_len == 4))
2884 skb->no_fcs = 1;
2885
2886 err = po->xmit(skb);
2887 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2888 goto out_unlock;
2889
2890 dev_put(dev);
2891
2892 return len;
2893
2894out_free:
2895 kfree_skb(skb);
2896out_unlock:
2897 if (dev)
2898 dev_put(dev);
2899out:
2900 return err;
2901}
2902
2903static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2904{
2905 struct sock *sk = sock->sk;
2906 struct packet_sock *po = pkt_sk(sk);
2907
2908 if (po->tx_ring.pg_vec)
2909 return tpacket_snd(po, msg);
2910 else
2911 return packet_snd(sock, msg, len);
2912}
2913
2914/*
2915 * Close a PACKET socket. This is fairly simple. We immediately go
2916 * to 'closed' state and remove our protocol entry in the device list.
2917 */
2918
2919static int packet_release(struct socket *sock)
2920{
2921 struct sock *sk = sock->sk;
2922 struct packet_sock *po;
2923 struct packet_fanout *f;
2924 struct net *net;
2925 union tpacket_req_u req_u;
2926
2927 if (!sk)
2928 return 0;
2929
2930 net = sock_net(sk);
2931 po = pkt_sk(sk);
2932
2933 mutex_lock(&net->packet.sklist_lock);
2934 sk_del_node_init_rcu(sk);
2935 mutex_unlock(&net->packet.sklist_lock);
2936
2937 preempt_disable();
2938 sock_prot_inuse_add(net, sk->sk_prot, -1);
2939 preempt_enable();
2940
2941 spin_lock(&po->bind_lock);
2942 unregister_prot_hook(sk, false);
2943 packet_cached_dev_reset(po);
2944
2945 if (po->prot_hook.dev) {
2946 dev_put(po->prot_hook.dev);
2947 po->prot_hook.dev = NULL;
2948 }
2949 spin_unlock(&po->bind_lock);
2950
2951 packet_flush_mclist(sk);
2952
2953 if (po->rx_ring.pg_vec) {
2954 memset(&req_u, 0, sizeof(req_u));
2955 packet_set_ring(sk, &req_u, 1, 0);
2956 }
2957
2958 if (po->tx_ring.pg_vec) {
2959 memset(&req_u, 0, sizeof(req_u));
2960 packet_set_ring(sk, &req_u, 1, 1);
2961 }
2962
2963 f = fanout_release(sk);
2964
2965 synchronize_net();
2966
2967 if (f) {
2968 fanout_release_data(f);
2969 kfree(f);
2970 }
2971 /*
2972 * Now the socket is dead. No more input will appear.
2973 */
2974 sock_orphan(sk);
2975 sock->sk = NULL;
2976
2977 /* Purge queues */
2978
2979 skb_queue_purge(&sk->sk_receive_queue);
2980 packet_free_pending(po);
2981 sk_refcnt_debug_release(sk);
2982
2983 sock_put(sk);
2984 return 0;
2985}
2986
2987/*
2988 * Attach a packet hook.
2989 */
2990
2991static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2992 __be16 proto)
2993{
2994 struct packet_sock *po = pkt_sk(sk);
2995 struct net_device *dev_curr;
2996 __be16 proto_curr;
2997 bool need_rehook;
2998 struct net_device *dev = NULL;
2999 int ret = 0;
3000 bool unlisted = false;
3001
3002 if (po->fanout)
3003 return -EINVAL;
3004
3005 lock_sock(sk);
3006 spin_lock(&po->bind_lock);
3007 rcu_read_lock();
3008
3009 if (name) {
3010 dev = dev_get_by_name_rcu(sock_net(sk), name);
3011 if (!dev) {
3012 ret = -ENODEV;
3013 goto out_unlock;
3014 }
3015 } else if (ifindex) {
3016 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3017 if (!dev) {
3018 ret = -ENODEV;
3019 goto out_unlock;
3020 }
3021 }
3022
3023 if (dev)
3024 dev_hold(dev);
3025
3026 proto_curr = po->prot_hook.type;
3027 dev_curr = po->prot_hook.dev;
3028
3029 need_rehook = proto_curr != proto || dev_curr != dev;
3030
3031 if (need_rehook) {
3032 if (po->running) {
3033 rcu_read_unlock();
3034 __unregister_prot_hook(sk, true);
3035 rcu_read_lock();
3036 dev_curr = po->prot_hook.dev;
3037 if (dev)
3038 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3039 dev->ifindex);
3040 }
3041
3042 po->num = proto;
3043 po->prot_hook.type = proto;
3044
3045 if (unlikely(unlisted)) {
3046 dev_put(dev);
3047 po->prot_hook.dev = NULL;
3048 po->ifindex = -1;
3049 packet_cached_dev_reset(po);
3050 } else {
3051 po->prot_hook.dev = dev;
3052 po->ifindex = dev ? dev->ifindex : 0;
3053 packet_cached_dev_assign(po, dev);
3054 }
3055 }
3056 if (dev_curr)
3057 dev_put(dev_curr);
3058
3059 if (proto == 0 || !need_rehook)
3060 goto out_unlock;
3061
3062 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3063 register_prot_hook(sk);
3064 } else {
3065 sk->sk_err = ENETDOWN;
3066 if (!sock_flag(sk, SOCK_DEAD))
3067 sk->sk_error_report(sk);
3068 }
3069
3070out_unlock:
3071 rcu_read_unlock();
3072 spin_unlock(&po->bind_lock);
3073 release_sock(sk);
3074 return ret;
3075}
3076
3077/*
3078 * Bind a packet socket to a device
3079 */
3080
3081static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3082 int addr_len)
3083{
3084 struct sock *sk = sock->sk;
3085 char name[sizeof(uaddr->sa_data) + 1];
3086
3087 /*
3088 * Check legality
3089 */
3090
3091 if (addr_len != sizeof(struct sockaddr))
3092 return -EINVAL;
3093 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3094 * zero-terminated.
3095 */
3096 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3097 name[sizeof(uaddr->sa_data)] = 0;
3098
3099 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3100}
3101
3102static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3103{
3104 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3105 struct sock *sk = sock->sk;
3106
3107 /*
3108 * Check legality
3109 */
3110
3111 if (addr_len < sizeof(struct sockaddr_ll))
3112 return -EINVAL;
3113 if (sll->sll_family != AF_PACKET)
3114 return -EINVAL;
3115
3116 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3117 sll->sll_protocol ? : pkt_sk(sk)->num);
3118}
3119
3120static struct proto packet_proto = {
3121 .name = "PACKET",
3122 .owner = THIS_MODULE,
3123 .obj_size = sizeof(struct packet_sock),
3124};
3125
3126/*
3127 * Create a packet of type SOCK_PACKET.
3128 */
3129
3130static int packet_create(struct net *net, struct socket *sock, int protocol,
3131 int kern)
3132{
3133 struct sock *sk;
3134 struct packet_sock *po;
3135 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3136 int err;
3137
3138 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3139 return -EPERM;
3140 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3141 sock->type != SOCK_PACKET)
3142 return -ESOCKTNOSUPPORT;
3143
3144 sock->state = SS_UNCONNECTED;
3145
3146 err = -ENOBUFS;
3147 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3148 if (sk == NULL)
3149 goto out;
3150
3151 sock->ops = &packet_ops;
3152 if (sock->type == SOCK_PACKET)
3153 sock->ops = &packet_ops_spkt;
3154
3155 sock_init_data(sock, sk);
3156
3157 po = pkt_sk(sk);
3158 sk->sk_family = PF_PACKET;
3159 po->num = proto;
3160 po->xmit = dev_queue_xmit;
3161
3162 err = packet_alloc_pending(po);
3163 if (err)
3164 goto out2;
3165
3166 packet_cached_dev_reset(po);
3167
3168 sk->sk_destruct = packet_sock_destruct;
3169 sk_refcnt_debug_inc(sk);
3170
3171 /*
3172 * Attach a protocol block
3173 */
3174
3175 spin_lock_init(&po->bind_lock);
3176 mutex_init(&po->pg_vec_lock);
3177 po->rollover = NULL;
3178 po->prot_hook.func = packet_rcv;
3179
3180 if (sock->type == SOCK_PACKET)
3181 po->prot_hook.func = packet_rcv_spkt;
3182
3183 po->prot_hook.af_packet_priv = sk;
3184
3185 if (proto) {
3186 po->prot_hook.type = proto;
3187 register_prot_hook(sk);
3188 }
3189
3190 mutex_lock(&net->packet.sklist_lock);
3191 sk_add_node_rcu(sk, &net->packet.sklist);
3192 mutex_unlock(&net->packet.sklist_lock);
3193
3194 preempt_disable();
3195 sock_prot_inuse_add(net, &packet_proto, 1);
3196 preempt_enable();
3197
3198 return 0;
3199out2:
3200 sk_free(sk);
3201out:
3202 return err;
3203}
3204
3205/*
3206 * Pull a packet from our receive queue and hand it to the user.
3207 * If necessary we block.
3208 */
3209
3210static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3211 int flags)
3212{
3213 struct sock *sk = sock->sk;
3214 struct sk_buff *skb;
3215 int copied, err;
3216 int vnet_hdr_len = 0;
3217 unsigned int origlen = 0;
3218
3219 err = -EINVAL;
3220 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3221 goto out;
3222
3223#if 0
3224 /* What error should we return now? EUNATTACH? */
3225 if (pkt_sk(sk)->ifindex < 0)
3226 return -ENODEV;
3227#endif
3228
3229 if (flags & MSG_ERRQUEUE) {
3230 err = sock_recv_errqueue(sk, msg, len,
3231 SOL_PACKET, PACKET_TX_TIMESTAMP);
3232 goto out;
3233 }
3234
3235 /*
3236 * Call the generic datagram receiver. This handles all sorts
3237 * of horrible races and re-entrancy so we can forget about it
3238 * in the protocol layers.
3239 *
3240 * Now it will return ENETDOWN, if device have just gone down,
3241 * but then it will block.
3242 */
3243
3244 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3245
3246 /*
3247 * An error occurred so return it. Because skb_recv_datagram()
3248 * handles the blocking we don't see and worry about blocking
3249 * retries.
3250 */
3251
3252 if (skb == NULL)
3253 goto out;
3254
3255 if (pkt_sk(sk)->pressure)
3256 packet_rcv_has_room(pkt_sk(sk), NULL);
3257
3258 if (pkt_sk(sk)->has_vnet_hdr) {
3259 err = packet_rcv_vnet(msg, skb, &len);
3260 if (err)
3261 goto out_free;
3262 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3263 }
3264
3265 /* You lose any data beyond the buffer you gave. If it worries
3266 * a user program they can ask the device for its MTU
3267 * anyway.
3268 */
3269 copied = skb->len;
3270 if (copied > len) {
3271 copied = len;
3272 msg->msg_flags |= MSG_TRUNC;
3273 }
3274
3275 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3276 if (err)
3277 goto out_free;
3278
3279 if (sock->type != SOCK_PACKET) {
3280 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3281
3282 /* Original length was stored in sockaddr_ll fields */
3283 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3284 sll->sll_family = AF_PACKET;
3285 sll->sll_protocol = skb->protocol;
3286 }
3287
3288 sock_recv_ts_and_drops(msg, sk, skb);
3289
3290 if (msg->msg_name) {
3291 /* If the address length field is there to be filled
3292 * in, we fill it in now.
3293 */
3294 if (sock->type == SOCK_PACKET) {
3295 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3296 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3297 } else {
3298 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3299
3300 msg->msg_namelen = sll->sll_halen +
3301 offsetof(struct sockaddr_ll, sll_addr);
3302 }
3303 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3304 msg->msg_namelen);
3305 }
3306
3307 if (pkt_sk(sk)->auxdata) {
3308 struct tpacket_auxdata aux;
3309
3310 aux.tp_status = TP_STATUS_USER;
3311 if (skb->ip_summed == CHECKSUM_PARTIAL)
3312 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3313 else if (skb->pkt_type != PACKET_OUTGOING &&
3314 (skb->ip_summed == CHECKSUM_COMPLETE ||
3315 skb_csum_unnecessary(skb)))
3316 aux.tp_status |= TP_STATUS_CSUM_VALID;
3317
3318 aux.tp_len = origlen;
3319 aux.tp_snaplen = skb->len;
3320 aux.tp_mac = 0;
3321 aux.tp_net = skb_network_offset(skb);
3322 if (skb_vlan_tag_present(skb)) {
3323 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3324 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3325 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3326 } else {
3327 aux.tp_vlan_tci = 0;
3328 aux.tp_vlan_tpid = 0;
3329 }
3330 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3331 }
3332
3333 /*
3334 * Free or return the buffer as appropriate. Again this
3335 * hides all the races and re-entrancy issues from us.
3336 */
3337 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3338
3339out_free:
3340 skb_free_datagram(sk, skb);
3341out:
3342 return err;
3343}
3344
3345static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3346 int *uaddr_len, int peer)
3347{
3348 struct net_device *dev;
3349 struct sock *sk = sock->sk;
3350
3351 if (peer)
3352 return -EOPNOTSUPP;
3353
3354 uaddr->sa_family = AF_PACKET;
3355 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3356 rcu_read_lock();
3357 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3358 if (dev)
3359 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3360 rcu_read_unlock();
3361 *uaddr_len = sizeof(*uaddr);
3362
3363 return 0;
3364}
3365
3366static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3367 int *uaddr_len, int peer)
3368{
3369 struct net_device *dev;
3370 struct sock *sk = sock->sk;
3371 struct packet_sock *po = pkt_sk(sk);
3372 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3373
3374 if (peer)
3375 return -EOPNOTSUPP;
3376
3377 sll->sll_family = AF_PACKET;
3378 sll->sll_ifindex = po->ifindex;
3379 sll->sll_protocol = po->num;
3380 sll->sll_pkttype = 0;
3381 rcu_read_lock();
3382 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3383 if (dev) {
3384 sll->sll_hatype = dev->type;
3385 sll->sll_halen = dev->addr_len;
3386 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3387 } else {
3388 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3389 sll->sll_halen = 0;
3390 }
3391 rcu_read_unlock();
3392 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3393
3394 return 0;
3395}
3396
3397static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3398 int what)
3399{
3400 switch (i->type) {
3401 case PACKET_MR_MULTICAST:
3402 if (i->alen != dev->addr_len)
3403 return -EINVAL;
3404 if (what > 0)
3405 return dev_mc_add(dev, i->addr);
3406 else
3407 return dev_mc_del(dev, i->addr);
3408 break;
3409 case PACKET_MR_PROMISC:
3410 return dev_set_promiscuity(dev, what);
3411 case PACKET_MR_ALLMULTI:
3412 return dev_set_allmulti(dev, what);
3413 case PACKET_MR_UNICAST:
3414 if (i->alen != dev->addr_len)
3415 return -EINVAL;
3416 if (what > 0)
3417 return dev_uc_add(dev, i->addr);
3418 else
3419 return dev_uc_del(dev, i->addr);
3420 break;
3421 default:
3422 break;
3423 }
3424 return 0;
3425}
3426
3427static void packet_dev_mclist_delete(struct net_device *dev,
3428 struct packet_mclist **mlp)
3429{
3430 struct packet_mclist *ml;
3431
3432 while ((ml = *mlp) != NULL) {
3433 if (ml->ifindex == dev->ifindex) {
3434 packet_dev_mc(dev, ml, -1);
3435 *mlp = ml->next;
3436 kfree(ml);
3437 } else
3438 mlp = &ml->next;
3439 }
3440}
3441
3442static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3443{
3444 struct packet_sock *po = pkt_sk(sk);
3445 struct packet_mclist *ml, *i;
3446 struct net_device *dev;
3447 int err;
3448
3449 rtnl_lock();
3450
3451 err = -ENODEV;
3452 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3453 if (!dev)
3454 goto done;
3455
3456 err = -EINVAL;
3457 if (mreq->mr_alen > dev->addr_len)
3458 goto done;
3459
3460 err = -ENOBUFS;
3461 i = kmalloc(sizeof(*i), GFP_KERNEL);
3462 if (i == NULL)
3463 goto done;
3464
3465 err = 0;
3466 for (ml = po->mclist; ml; ml = ml->next) {
3467 if (ml->ifindex == mreq->mr_ifindex &&
3468 ml->type == mreq->mr_type &&
3469 ml->alen == mreq->mr_alen &&
3470 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3471 ml->count++;
3472 /* Free the new element ... */
3473 kfree(i);
3474 goto done;
3475 }
3476 }
3477
3478 i->type = mreq->mr_type;
3479 i->ifindex = mreq->mr_ifindex;
3480 i->alen = mreq->mr_alen;
3481 memcpy(i->addr, mreq->mr_address, i->alen);
3482 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3483 i->count = 1;
3484 i->next = po->mclist;
3485 po->mclist = i;
3486 err = packet_dev_mc(dev, i, 1);
3487 if (err) {
3488 po->mclist = i->next;
3489 kfree(i);
3490 }
3491
3492done:
3493 rtnl_unlock();
3494 return err;
3495}
3496
3497static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3498{
3499 struct packet_mclist *ml, **mlp;
3500
3501 rtnl_lock();
3502
3503 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3504 if (ml->ifindex == mreq->mr_ifindex &&
3505 ml->type == mreq->mr_type &&
3506 ml->alen == mreq->mr_alen &&
3507 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3508 if (--ml->count == 0) {
3509 struct net_device *dev;
3510 *mlp = ml->next;
3511 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3512 if (dev)
3513 packet_dev_mc(dev, ml, -1);
3514 kfree(ml);
3515 }
3516 break;
3517 }
3518 }
3519 rtnl_unlock();
3520 return 0;
3521}
3522
3523static void packet_flush_mclist(struct sock *sk)
3524{
3525 struct packet_sock *po = pkt_sk(sk);
3526 struct packet_mclist *ml;
3527
3528 if (!po->mclist)
3529 return;
3530
3531 rtnl_lock();
3532 while ((ml = po->mclist) != NULL) {
3533 struct net_device *dev;
3534
3535 po->mclist = ml->next;
3536 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3537 if (dev != NULL)
3538 packet_dev_mc(dev, ml, -1);
3539 kfree(ml);
3540 }
3541 rtnl_unlock();
3542}
3543
3544static int
3545packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3546{
3547 struct sock *sk = sock->sk;
3548 struct packet_sock *po = pkt_sk(sk);
3549 int ret;
3550
3551 if (level != SOL_PACKET)
3552 return -ENOPROTOOPT;
3553
3554 switch (optname) {
3555 case PACKET_ADD_MEMBERSHIP:
3556 case PACKET_DROP_MEMBERSHIP:
3557 {
3558 struct packet_mreq_max mreq;
3559 int len = optlen;
3560 memset(&mreq, 0, sizeof(mreq));
3561 if (len < sizeof(struct packet_mreq))
3562 return -EINVAL;
3563 if (len > sizeof(mreq))
3564 len = sizeof(mreq);
3565 if (copy_from_user(&mreq, optval, len))
3566 return -EFAULT;
3567 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3568 return -EINVAL;
3569 if (optname == PACKET_ADD_MEMBERSHIP)
3570 ret = packet_mc_add(sk, &mreq);
3571 else
3572 ret = packet_mc_drop(sk, &mreq);
3573 return ret;
3574 }
3575
3576 case PACKET_RX_RING:
3577 case PACKET_TX_RING:
3578 {
3579 union tpacket_req_u req_u;
3580 int len;
3581
3582 switch (po->tp_version) {
3583 case TPACKET_V1:
3584 case TPACKET_V2:
3585 len = sizeof(req_u.req);
3586 break;
3587 case TPACKET_V3:
3588 default:
3589 len = sizeof(req_u.req3);
3590 break;
3591 }
3592 if (optlen < len)
3593 return -EINVAL;
3594 if (copy_from_user(&req_u.req, optval, len))
3595 return -EFAULT;
3596 return packet_set_ring(sk, &req_u, 0,
3597 optname == PACKET_TX_RING);
3598 }
3599 case PACKET_COPY_THRESH:
3600 {
3601 int val;
3602
3603 if (optlen != sizeof(val))
3604 return -EINVAL;
3605 if (copy_from_user(&val, optval, sizeof(val)))
3606 return -EFAULT;
3607
3608 pkt_sk(sk)->copy_thresh = val;
3609 return 0;
3610 }
3611 case PACKET_VERSION:
3612 {
3613 int val;
3614
3615 if (optlen != sizeof(val))
3616 return -EINVAL;
3617 if (copy_from_user(&val, optval, sizeof(val)))
3618 return -EFAULT;
3619 switch (val) {
3620 case TPACKET_V1:
3621 case TPACKET_V2:
3622 case TPACKET_V3:
3623 break;
3624 default:
3625 return -EINVAL;
3626 }
3627 lock_sock(sk);
3628 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3629 ret = -EBUSY;
3630 } else {
3631 po->tp_version = val;
3632 ret = 0;
3633 }
3634 release_sock(sk);
3635 return ret;
3636 }
3637 case PACKET_RESERVE:
3638 {
3639 unsigned int val;
3640
3641 if (optlen != sizeof(val))
3642 return -EINVAL;
3643 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3644 return -EBUSY;
3645 if (copy_from_user(&val, optval, sizeof(val)))
3646 return -EFAULT;
3647 po->tp_reserve = val;
3648 return 0;
3649 }
3650 case PACKET_LOSS:
3651 {
3652 unsigned int val;
3653
3654 if (optlen != sizeof(val))
3655 return -EINVAL;
3656 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3657 return -EBUSY;
3658 if (copy_from_user(&val, optval, sizeof(val)))
3659 return -EFAULT;
3660 po->tp_loss = !!val;
3661 return 0;
3662 }
3663 case PACKET_AUXDATA:
3664 {
3665 int val;
3666
3667 if (optlen < sizeof(val))
3668 return -EINVAL;
3669 if (copy_from_user(&val, optval, sizeof(val)))
3670 return -EFAULT;
3671
3672 po->auxdata = !!val;
3673 return 0;
3674 }
3675 case PACKET_ORIGDEV:
3676 {
3677 int val;
3678
3679 if (optlen < sizeof(val))
3680 return -EINVAL;
3681 if (copy_from_user(&val, optval, sizeof(val)))
3682 return -EFAULT;
3683
3684 po->origdev = !!val;
3685 return 0;
3686 }
3687 case PACKET_VNET_HDR:
3688 {
3689 int val;
3690
3691 if (sock->type != SOCK_RAW)
3692 return -EINVAL;
3693 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3694 return -EBUSY;
3695 if (optlen < sizeof(val))
3696 return -EINVAL;
3697 if (copy_from_user(&val, optval, sizeof(val)))
3698 return -EFAULT;
3699
3700 po->has_vnet_hdr = !!val;
3701 return 0;
3702 }
3703 case PACKET_TIMESTAMP:
3704 {
3705 int val;
3706
3707 if (optlen != sizeof(val))
3708 return -EINVAL;
3709 if (copy_from_user(&val, optval, sizeof(val)))
3710 return -EFAULT;
3711
3712 po->tp_tstamp = val;
3713 return 0;
3714 }
3715 case PACKET_FANOUT:
3716 {
3717 int val;
3718
3719 if (optlen != sizeof(val))
3720 return -EINVAL;
3721 if (copy_from_user(&val, optval, sizeof(val)))
3722 return -EFAULT;
3723
3724 return fanout_add(sk, val & 0xffff, val >> 16);
3725 }
3726 case PACKET_FANOUT_DATA:
3727 {
3728 if (!po->fanout)
3729 return -EINVAL;
3730
3731 return fanout_set_data(po, optval, optlen);
3732 }
3733 case PACKET_TX_HAS_OFF:
3734 {
3735 unsigned int val;
3736
3737 if (optlen != sizeof(val))
3738 return -EINVAL;
3739 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3740 return -EBUSY;
3741 if (copy_from_user(&val, optval, sizeof(val)))
3742 return -EFAULT;
3743 po->tp_tx_has_off = !!val;
3744 return 0;
3745 }
3746 case PACKET_QDISC_BYPASS:
3747 {
3748 int val;
3749
3750 if (optlen != sizeof(val))
3751 return -EINVAL;
3752 if (copy_from_user(&val, optval, sizeof(val)))
3753 return -EFAULT;
3754
3755 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3756 return 0;
3757 }
3758 default:
3759 return -ENOPROTOOPT;
3760 }
3761}
3762
3763static int packet_getsockopt(struct socket *sock, int level, int optname,
3764 char __user *optval, int __user *optlen)
3765{
3766 int len;
3767 int val, lv = sizeof(val);
3768 struct sock *sk = sock->sk;
3769 struct packet_sock *po = pkt_sk(sk);
3770 void *data = &val;
3771 union tpacket_stats_u st;
3772 struct tpacket_rollover_stats rstats;
3773
3774 if (level != SOL_PACKET)
3775 return -ENOPROTOOPT;
3776
3777 if (get_user(len, optlen))
3778 return -EFAULT;
3779
3780 if (len < 0)
3781 return -EINVAL;
3782
3783 switch (optname) {
3784 case PACKET_STATISTICS:
3785 spin_lock_bh(&sk->sk_receive_queue.lock);
3786 memcpy(&st, &po->stats, sizeof(st));
3787 memset(&po->stats, 0, sizeof(po->stats));
3788 spin_unlock_bh(&sk->sk_receive_queue.lock);
3789
3790 if (po->tp_version == TPACKET_V3) {
3791 lv = sizeof(struct tpacket_stats_v3);
3792 st.stats3.tp_packets += st.stats3.tp_drops;
3793 data = &st.stats3;
3794 } else {
3795 lv = sizeof(struct tpacket_stats);
3796 st.stats1.tp_packets += st.stats1.tp_drops;
3797 data = &st.stats1;
3798 }
3799
3800 break;
3801 case PACKET_AUXDATA:
3802 val = po->auxdata;
3803 break;
3804 case PACKET_ORIGDEV:
3805 val = po->origdev;
3806 break;
3807 case PACKET_VNET_HDR:
3808 val = po->has_vnet_hdr;
3809 break;
3810 case PACKET_VERSION:
3811 val = po->tp_version;
3812 break;
3813 case PACKET_HDRLEN:
3814 if (len > sizeof(int))
3815 len = sizeof(int);
3816 if (copy_from_user(&val, optval, len))
3817 return -EFAULT;
3818 switch (val) {
3819 case TPACKET_V1:
3820 val = sizeof(struct tpacket_hdr);
3821 break;
3822 case TPACKET_V2:
3823 val = sizeof(struct tpacket2_hdr);
3824 break;
3825 case TPACKET_V3:
3826 val = sizeof(struct tpacket3_hdr);
3827 break;
3828 default:
3829 return -EINVAL;
3830 }
3831 break;
3832 case PACKET_RESERVE:
3833 val = po->tp_reserve;
3834 break;
3835 case PACKET_LOSS:
3836 val = po->tp_loss;
3837 break;
3838 case PACKET_TIMESTAMP:
3839 val = po->tp_tstamp;
3840 break;
3841 case PACKET_FANOUT:
3842 val = (po->fanout ?
3843 ((u32)po->fanout->id |
3844 ((u32)po->fanout->type << 16) |
3845 ((u32)po->fanout->flags << 24)) :
3846 0);
3847 break;
3848 case PACKET_ROLLOVER_STATS:
3849 if (!po->rollover)
3850 return -EINVAL;
3851 rstats.tp_all = atomic_long_read(&po->rollover->num);
3852 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3853 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3854 data = &rstats;
3855 lv = sizeof(rstats);
3856 break;
3857 case PACKET_TX_HAS_OFF:
3858 val = po->tp_tx_has_off;
3859 break;
3860 case PACKET_QDISC_BYPASS:
3861 val = packet_use_direct_xmit(po);
3862 break;
3863 default:
3864 return -ENOPROTOOPT;
3865 }
3866
3867 if (len > lv)
3868 len = lv;
3869 if (put_user(len, optlen))
3870 return -EFAULT;
3871 if (copy_to_user(optval, data, len))
3872 return -EFAULT;
3873 return 0;
3874}
3875
3876
3877#ifdef CONFIG_COMPAT
3878static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
3879 char __user *optval, unsigned int optlen)
3880{
3881 struct packet_sock *po = pkt_sk(sock->sk);
3882
3883 if (level != SOL_PACKET)
3884 return -ENOPROTOOPT;
3885
3886 if (optname == PACKET_FANOUT_DATA &&
3887 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
3888 optval = (char __user *)get_compat_bpf_fprog(optval);
3889 if (!optval)
3890 return -EFAULT;
3891 optlen = sizeof(struct sock_fprog);
3892 }
3893
3894 return packet_setsockopt(sock, level, optname, optval, optlen);
3895}
3896#endif
3897
3898static int packet_notifier(struct notifier_block *this,
3899 unsigned long msg, void *ptr)
3900{
3901 struct sock *sk;
3902 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3903 struct net *net = dev_net(dev);
3904
3905 rcu_read_lock();
3906 sk_for_each_rcu(sk, &net->packet.sklist) {
3907 struct packet_sock *po = pkt_sk(sk);
3908
3909 switch (msg) {
3910 case NETDEV_UNREGISTER:
3911 if (po->mclist)
3912 packet_dev_mclist_delete(dev, &po->mclist);
3913 /* fallthrough */
3914
3915 case NETDEV_DOWN:
3916 if (dev->ifindex == po->ifindex) {
3917 spin_lock(&po->bind_lock);
3918 if (po->running) {
3919 __unregister_prot_hook(sk, false);
3920 sk->sk_err = ENETDOWN;
3921 if (!sock_flag(sk, SOCK_DEAD))
3922 sk->sk_error_report(sk);
3923 }
3924 if (msg == NETDEV_UNREGISTER) {
3925 packet_cached_dev_reset(po);
3926 po->ifindex = -1;
3927 if (po->prot_hook.dev)
3928 dev_put(po->prot_hook.dev);
3929 po->prot_hook.dev = NULL;
3930 }
3931 spin_unlock(&po->bind_lock);
3932 }
3933 break;
3934 case NETDEV_UP:
3935 if (dev->ifindex == po->ifindex) {
3936 spin_lock(&po->bind_lock);
3937 if (po->num)
3938 register_prot_hook(sk);
3939 spin_unlock(&po->bind_lock);
3940 }
3941 break;
3942 }
3943 }
3944 rcu_read_unlock();
3945 return NOTIFY_DONE;
3946}
3947
3948
3949static int packet_ioctl(struct socket *sock, unsigned int cmd,
3950 unsigned long arg)
3951{
3952 struct sock *sk = sock->sk;
3953
3954 switch (cmd) {
3955 case SIOCOUTQ:
3956 {
3957 int amount = sk_wmem_alloc_get(sk);
3958
3959 return put_user(amount, (int __user *)arg);
3960 }
3961 case SIOCINQ:
3962 {
3963 struct sk_buff *skb;
3964 int amount = 0;
3965
3966 spin_lock_bh(&sk->sk_receive_queue.lock);
3967 skb = skb_peek(&sk->sk_receive_queue);
3968 if (skb)
3969 amount = skb->len;
3970 spin_unlock_bh(&sk->sk_receive_queue.lock);
3971 return put_user(amount, (int __user *)arg);
3972 }
3973 case SIOCGSTAMP:
3974 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3975 case SIOCGSTAMPNS:
3976 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3977
3978#ifdef CONFIG_INET
3979 case SIOCADDRT:
3980 case SIOCDELRT:
3981 case SIOCDARP:
3982 case SIOCGARP:
3983 case SIOCSARP:
3984 case SIOCGIFADDR:
3985 case SIOCSIFADDR:
3986 case SIOCGIFBRDADDR:
3987 case SIOCSIFBRDADDR:
3988 case SIOCGIFNETMASK:
3989 case SIOCSIFNETMASK:
3990 case SIOCGIFDSTADDR:
3991 case SIOCSIFDSTADDR:
3992 case SIOCSIFFLAGS:
3993 return inet_dgram_ops.ioctl(sock, cmd, arg);
3994#endif
3995
3996 default:
3997 return -ENOIOCTLCMD;
3998 }
3999 return 0;
4000}
4001
4002static unsigned int packet_poll(struct file *file, struct socket *sock,
4003 poll_table *wait)
4004{
4005 struct sock *sk = sock->sk;
4006 struct packet_sock *po = pkt_sk(sk);
4007 unsigned int mask = datagram_poll(file, sock, wait);
4008
4009 spin_lock_bh(&sk->sk_receive_queue.lock);
4010 if (po->rx_ring.pg_vec) {
4011 if (!packet_previous_rx_frame(po, &po->rx_ring,
4012 TP_STATUS_KERNEL))
4013 mask |= POLLIN | POLLRDNORM;
4014 }
4015 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
4016 po->pressure = 0;
4017 spin_unlock_bh(&sk->sk_receive_queue.lock);
4018 spin_lock_bh(&sk->sk_write_queue.lock);
4019 if (po->tx_ring.pg_vec) {
4020 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4021 mask |= POLLOUT | POLLWRNORM;
4022 }
4023 spin_unlock_bh(&sk->sk_write_queue.lock);
4024 return mask;
4025}
4026
4027
4028/* Dirty? Well, I still did not learn better way to account
4029 * for user mmaps.
4030 */
4031
4032static void packet_mm_open(struct vm_area_struct *vma)
4033{
4034 struct file *file = vma->vm_file;
4035 struct socket *sock = file->private_data;
4036 struct sock *sk = sock->sk;
4037
4038 if (sk)
4039 atomic_inc(&pkt_sk(sk)->mapped);
4040}
4041
4042static void packet_mm_close(struct vm_area_struct *vma)
4043{
4044 struct file *file = vma->vm_file;
4045 struct socket *sock = file->private_data;
4046 struct sock *sk = sock->sk;
4047
4048 if (sk)
4049 atomic_dec(&pkt_sk(sk)->mapped);
4050}
4051
4052static const struct vm_operations_struct packet_mmap_ops = {
4053 .open = packet_mm_open,
4054 .close = packet_mm_close,
4055};
4056
4057static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4058 unsigned int len)
4059{
4060 int i;
4061
4062 for (i = 0; i < len; i++) {
4063 if (likely(pg_vec[i].buffer)) {
4064 if (is_vmalloc_addr(pg_vec[i].buffer))
4065 vfree(pg_vec[i].buffer);
4066 else
4067 free_pages((unsigned long)pg_vec[i].buffer,
4068 order);
4069 pg_vec[i].buffer = NULL;
4070 }
4071 }
4072 kfree(pg_vec);
4073}
4074
4075static char *alloc_one_pg_vec_page(unsigned long order)
4076{
4077 char *buffer;
4078 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4079 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4080
4081 buffer = (char *) __get_free_pages(gfp_flags, order);
4082 if (buffer)
4083 return buffer;
4084
4085 /* __get_free_pages failed, fall back to vmalloc */
4086 buffer = vzalloc((1 << order) * PAGE_SIZE);
4087 if (buffer)
4088 return buffer;
4089
4090 /* vmalloc failed, lets dig into swap here */
4091 gfp_flags &= ~__GFP_NORETRY;
4092 buffer = (char *) __get_free_pages(gfp_flags, order);
4093 if (buffer)
4094 return buffer;
4095
4096 /* complete and utter failure */
4097 return NULL;
4098}
4099
4100static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4101{
4102 unsigned int block_nr = req->tp_block_nr;
4103 struct pgv *pg_vec;
4104 int i;
4105
4106 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4107 if (unlikely(!pg_vec))
4108 goto out;
4109
4110 for (i = 0; i < block_nr; i++) {
4111 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4112 if (unlikely(!pg_vec[i].buffer))
4113 goto out_free_pgvec;
4114 }
4115
4116out:
4117 return pg_vec;
4118
4119out_free_pgvec:
4120 free_pg_vec(pg_vec, order, block_nr);
4121 pg_vec = NULL;
4122 goto out;
4123}
4124
4125static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4126 int closing, int tx_ring)
4127{
4128 struct pgv *pg_vec = NULL;
4129 struct packet_sock *po = pkt_sk(sk);
4130 int was_running, order = 0;
4131 struct packet_ring_buffer *rb;
4132 struct sk_buff_head *rb_queue;
4133 __be16 num;
4134 int err = -EINVAL;
4135 /* Added to avoid minimal code churn */
4136 struct tpacket_req *req = &req_u->req;
4137
4138 lock_sock(sk);
4139 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4140 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4141 net_warn_ratelimited("Tx-ring is not supported.\n");
4142 goto out;
4143 }
4144
4145 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4146 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4147
4148 err = -EBUSY;
4149 if (!closing) {
4150 if (atomic_read(&po->mapped))
4151 goto out;
4152 if (packet_read_pending(rb))
4153 goto out;
4154 }
4155
4156 if (req->tp_block_nr) {
4157 /* Sanity tests and some calculations */
4158 err = -EBUSY;
4159 if (unlikely(rb->pg_vec))
4160 goto out;
4161
4162 switch (po->tp_version) {
4163 case TPACKET_V1:
4164 po->tp_hdrlen = TPACKET_HDRLEN;
4165 break;
4166 case TPACKET_V2:
4167 po->tp_hdrlen = TPACKET2_HDRLEN;
4168 break;
4169 case TPACKET_V3:
4170 po->tp_hdrlen = TPACKET3_HDRLEN;
4171 break;
4172 }
4173
4174 err = -EINVAL;
4175 if (unlikely((int)req->tp_block_size <= 0))
4176 goto out;
4177 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4178 goto out;
4179 if (po->tp_version >= TPACKET_V3 &&
4180 req->tp_block_size <=
4181 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
4182 goto out;
4183 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4184 po->tp_reserve))
4185 goto out;
4186 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4187 goto out;
4188
4189 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4190 if (unlikely(rb->frames_per_block == 0))
4191 goto out;
4192 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4193 req->tp_frame_nr))
4194 goto out;
4195
4196 err = -ENOMEM;
4197 order = get_order(req->tp_block_size);
4198 pg_vec = alloc_pg_vec(req, order);
4199 if (unlikely(!pg_vec))
4200 goto out;
4201 switch (po->tp_version) {
4202 case TPACKET_V3:
4203 /* Transmit path is not supported. We checked
4204 * it above but just being paranoid
4205 */
4206 if (!tx_ring)
4207 init_prb_bdqc(po, rb, pg_vec, req_u);
4208 break;
4209 default:
4210 break;
4211 }
4212 }
4213 /* Done */
4214 else {
4215 err = -EINVAL;
4216 if (unlikely(req->tp_frame_nr))
4217 goto out;
4218 }
4219
4220
4221 /* Detach socket from network */
4222 spin_lock(&po->bind_lock);
4223 was_running = po->running;
4224 num = po->num;
4225 if (was_running) {
4226 po->num = 0;
4227 __unregister_prot_hook(sk, false);
4228 }
4229 spin_unlock(&po->bind_lock);
4230
4231 synchronize_net();
4232
4233 err = -EBUSY;
4234 mutex_lock(&po->pg_vec_lock);
4235 if (closing || atomic_read(&po->mapped) == 0) {
4236 err = 0;
4237 spin_lock_bh(&rb_queue->lock);
4238 swap(rb->pg_vec, pg_vec);
4239 rb->frame_max = (req->tp_frame_nr - 1);
4240 rb->head = 0;
4241 rb->frame_size = req->tp_frame_size;
4242 spin_unlock_bh(&rb_queue->lock);
4243
4244 swap(rb->pg_vec_order, order);
4245 swap(rb->pg_vec_len, req->tp_block_nr);
4246
4247 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4248 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4249 tpacket_rcv : packet_rcv;
4250 skb_queue_purge(rb_queue);
4251 if (atomic_read(&po->mapped))
4252 pr_err("packet_mmap: vma is busy: %d\n",
4253 atomic_read(&po->mapped));
4254 }
4255 mutex_unlock(&po->pg_vec_lock);
4256
4257 spin_lock(&po->bind_lock);
4258 if (was_running) {
4259 po->num = num;
4260 register_prot_hook(sk);
4261 }
4262 spin_unlock(&po->bind_lock);
4263 if (closing && (po->tp_version > TPACKET_V2)) {
4264 /* Because we don't support block-based V3 on tx-ring */
4265 if (!tx_ring)
4266 prb_shutdown_retire_blk_timer(po, rb_queue);
4267 }
4268
4269 if (pg_vec)
4270 free_pg_vec(pg_vec, order, req->tp_block_nr);
4271out:
4272 release_sock(sk);
4273 return err;
4274}
4275
4276static int packet_mmap(struct file *file, struct socket *sock,
4277 struct vm_area_struct *vma)
4278{
4279 struct sock *sk = sock->sk;
4280 struct packet_sock *po = pkt_sk(sk);
4281 unsigned long size, expected_size;
4282 struct packet_ring_buffer *rb;
4283 unsigned long start;
4284 int err = -EINVAL;
4285 int i;
4286
4287 if (vma->vm_pgoff)
4288 return -EINVAL;
4289
4290 mutex_lock(&po->pg_vec_lock);
4291
4292 expected_size = 0;
4293 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4294 if (rb->pg_vec) {
4295 expected_size += rb->pg_vec_len
4296 * rb->pg_vec_pages
4297 * PAGE_SIZE;
4298 }
4299 }
4300
4301 if (expected_size == 0)
4302 goto out;
4303
4304 size = vma->vm_end - vma->vm_start;
4305 if (size != expected_size)
4306 goto out;
4307
4308 start = vma->vm_start;
4309 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4310 if (rb->pg_vec == NULL)
4311 continue;
4312
4313 for (i = 0; i < rb->pg_vec_len; i++) {
4314 struct page *page;
4315 void *kaddr = rb->pg_vec[i].buffer;
4316 int pg_num;
4317
4318 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4319 page = pgv_to_page(kaddr);
4320 err = vm_insert_page(vma, start, page);
4321 if (unlikely(err))
4322 goto out;
4323 start += PAGE_SIZE;
4324 kaddr += PAGE_SIZE;
4325 }
4326 }
4327 }
4328
4329 atomic_inc(&po->mapped);
4330 vma->vm_ops = &packet_mmap_ops;
4331 err = 0;
4332
4333out:
4334 mutex_unlock(&po->pg_vec_lock);
4335 return err;
4336}
4337
4338static const struct proto_ops packet_ops_spkt = {
4339 .family = PF_PACKET,
4340 .owner = THIS_MODULE,
4341 .release = packet_release,
4342 .bind = packet_bind_spkt,
4343 .connect = sock_no_connect,
4344 .socketpair = sock_no_socketpair,
4345 .accept = sock_no_accept,
4346 .getname = packet_getname_spkt,
4347 .poll = datagram_poll,
4348 .ioctl = packet_ioctl,
4349 .listen = sock_no_listen,
4350 .shutdown = sock_no_shutdown,
4351 .setsockopt = sock_no_setsockopt,
4352 .getsockopt = sock_no_getsockopt,
4353 .sendmsg = packet_sendmsg_spkt,
4354 .recvmsg = packet_recvmsg,
4355 .mmap = sock_no_mmap,
4356 .sendpage = sock_no_sendpage,
4357};
4358
4359static const struct proto_ops packet_ops = {
4360 .family = PF_PACKET,
4361 .owner = THIS_MODULE,
4362 .release = packet_release,
4363 .bind = packet_bind,
4364 .connect = sock_no_connect,
4365 .socketpair = sock_no_socketpair,
4366 .accept = sock_no_accept,
4367 .getname = packet_getname,
4368 .poll = packet_poll,
4369 .ioctl = packet_ioctl,
4370 .listen = sock_no_listen,
4371 .shutdown = sock_no_shutdown,
4372 .setsockopt = packet_setsockopt,
4373 .getsockopt = packet_getsockopt,
4374#ifdef CONFIG_COMPAT
4375 .compat_setsockopt = compat_packet_setsockopt,
4376#endif
4377 .sendmsg = packet_sendmsg,
4378 .recvmsg = packet_recvmsg,
4379 .mmap = packet_mmap,
4380 .sendpage = sock_no_sendpage,
4381};
4382
4383static const struct net_proto_family packet_family_ops = {
4384 .family = PF_PACKET,
4385 .create = packet_create,
4386 .owner = THIS_MODULE,
4387};
4388
4389static struct notifier_block packet_netdev_notifier = {
4390 .notifier_call = packet_notifier,
4391};
4392
4393#ifdef CONFIG_PROC_FS
4394
4395static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4396 __acquires(RCU)
4397{
4398 struct net *net = seq_file_net(seq);
4399
4400 rcu_read_lock();
4401 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4402}
4403
4404static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4405{
4406 struct net *net = seq_file_net(seq);
4407 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4408}
4409
4410static void packet_seq_stop(struct seq_file *seq, void *v)
4411 __releases(RCU)
4412{
4413 rcu_read_unlock();
4414}
4415
4416static int packet_seq_show(struct seq_file *seq, void *v)
4417{
4418 if (v == SEQ_START_TOKEN)
4419 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4420 else {
4421 struct sock *s = sk_entry(v);
4422 const struct packet_sock *po = pkt_sk(s);
4423
4424 seq_printf(seq,
4425 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4426 s,
4427 atomic_read(&s->sk_refcnt),
4428 s->sk_type,
4429 ntohs(po->num),
4430 po->ifindex,
4431 po->running,
4432 atomic_read(&s->sk_rmem_alloc),
4433 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4434 sock_i_ino(s));
4435 }
4436
4437 return 0;
4438}
4439
4440static const struct seq_operations packet_seq_ops = {
4441 .start = packet_seq_start,
4442 .next = packet_seq_next,
4443 .stop = packet_seq_stop,
4444 .show = packet_seq_show,
4445};
4446
4447static int packet_seq_open(struct inode *inode, struct file *file)
4448{
4449 return seq_open_net(inode, file, &packet_seq_ops,
4450 sizeof(struct seq_net_private));
4451}
4452
4453static const struct file_operations packet_seq_fops = {
4454 .owner = THIS_MODULE,
4455 .open = packet_seq_open,
4456 .read = seq_read,
4457 .llseek = seq_lseek,
4458 .release = seq_release_net,
4459};
4460
4461#endif
4462
4463static int __net_init packet_net_init(struct net *net)
4464{
4465 mutex_init(&net->packet.sklist_lock);
4466 INIT_HLIST_HEAD(&net->packet.sklist);
4467
4468 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4469 return -ENOMEM;
4470
4471 return 0;
4472}
4473
4474static void __net_exit packet_net_exit(struct net *net)
4475{
4476 remove_proc_entry("packet", net->proc_net);
4477}
4478
4479static struct pernet_operations packet_net_ops = {
4480 .init = packet_net_init,
4481 .exit = packet_net_exit,
4482};
4483
4484
4485static void __exit packet_exit(void)
4486{
4487 unregister_netdevice_notifier(&packet_netdev_notifier);
4488 unregister_pernet_subsys(&packet_net_ops);
4489 sock_unregister(PF_PACKET);
4490 proto_unregister(&packet_proto);
4491}
4492
4493static int __init packet_init(void)
4494{
4495 int rc = proto_register(&packet_proto, 0);
4496
4497 if (rc != 0)
4498 goto out;
4499
4500 sock_register(&packet_family_ops);
4501 register_pernet_subsys(&packet_net_ops);
4502 register_netdevice_notifier(&packet_netdev_notifier);
4503out:
4504 return rc;
4505}
4506
4507module_init(packet_init);
4508module_exit(packet_exit);
4509MODULE_LICENSE("GPL");
4510MODULE_ALIAS_NETPROTO(PF_PACKET);