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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#include <linux/types.h>
50#include <linux/mm.h>
51#include <linux/capability.h>
52#include <linux/fcntl.h>
53#include <linux/socket.h>
54#include <linux/in.h>
55#include <linux/inet.h>
56#include <linux/netdevice.h>
57#include <linux/if_packet.h>
58#include <linux/wireless.h>
59#include <linux/kernel.h>
60#include <linux/kmod.h>
61#include <linux/slab.h>
62#include <linux/vmalloc.h>
63#include <net/net_namespace.h>
64#include <net/ip.h>
65#include <net/protocol.h>
66#include <linux/skbuff.h>
67#include <net/sock.h>
68#include <linux/errno.h>
69#include <linux/timer.h>
70#include <linux/uaccess.h>
71#include <asm/ioctls.h>
72#include <asm/page.h>
73#include <asm/cacheflush.h>
74#include <asm/io.h>
75#include <linux/proc_fs.h>
76#include <linux/seq_file.h>
77#include <linux/poll.h>
78#include <linux/module.h>
79#include <linux/init.h>
80#include <linux/mutex.h>
81#include <linux/if_vlan.h>
82#include <linux/virtio_net.h>
83#include <linux/errqueue.h>
84#include <linux/net_tstamp.h>
85#include <linux/percpu.h>
86#ifdef CONFIG_INET
87#include <net/inet_common.h>
88#endif
89#include <linux/bpf.h>
90#include <net/compat.h>
91
92#include "internal.h"
93
94/*
95 Assumptions:
96 - if device has no dev->hard_header routine, it adds and removes ll header
97 inside itself. In this case ll header is invisible outside of device,
98 but higher levels still should reserve dev->hard_header_len.
99 Some devices are enough clever to reallocate skb, when header
100 will not fit to reserved space (tunnel), another ones are silly
101 (PPP).
102 - packet socket receives packets with pulled ll header,
103 so that SOCK_RAW should push it back.
104
105On receive:
106-----------
107
108Incoming, dev->hard_header!=NULL
109 mac_header -> ll header
110 data -> data
111
112Outgoing, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> ll header
115
116Incoming, dev->hard_header==NULL
117 mac_header -> UNKNOWN position. It is very likely, that it points to ll
118 header. PPP makes it, that is wrong, because introduce
119 assymetry between rx and tx paths.
120 data -> data
121
122Outgoing, dev->hard_header==NULL
123 mac_header -> data. ll header is still not built!
124 data -> data
125
126Resume
127 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
128
129
130On transmit:
131------------
132
133dev->hard_header != NULL
134 mac_header -> ll header
135 data -> ll header
136
137dev->hard_header == NULL (ll header is added by device, we cannot control it)
138 mac_header -> data
139 data -> data
140
141 We should set nh.raw on output to correct posistion,
142 packet classifier depends on it.
143 */
144
145/* Private packet socket structures. */
146
147/* identical to struct packet_mreq except it has
148 * a longer address field.
149 */
150struct packet_mreq_max {
151 int mr_ifindex;
152 unsigned short mr_type;
153 unsigned short mr_alen;
154 unsigned char mr_address[MAX_ADDR_LEN];
155};
156
157union tpacket_uhdr {
158 struct tpacket_hdr *h1;
159 struct tpacket2_hdr *h2;
160 struct tpacket3_hdr *h3;
161 void *raw;
162};
163
164static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
165 int closing, int tx_ring);
166
167#define V3_ALIGNMENT (8)
168
169#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
170
171#define BLK_PLUS_PRIV(sz_of_priv) \
172 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
173
174#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
175#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
176#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
177#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
178#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
179#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
180#define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
181
182struct packet_sock;
183static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
184 struct packet_type *pt, struct net_device *orig_dev);
185
186static void *packet_previous_frame(struct packet_sock *po,
187 struct packet_ring_buffer *rb,
188 int status);
189static void packet_increment_head(struct packet_ring_buffer *buff);
190static int prb_curr_blk_in_use(struct tpacket_block_desc *);
191static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
192 struct packet_sock *);
193static void prb_retire_current_block(struct tpacket_kbdq_core *,
194 struct packet_sock *, unsigned int status);
195static int prb_queue_frozen(struct tpacket_kbdq_core *);
196static void prb_open_block(struct tpacket_kbdq_core *,
197 struct tpacket_block_desc *);
198static void prb_retire_rx_blk_timer_expired(struct timer_list *);
199static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
200static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
201static void prb_clear_rxhash(struct tpacket_kbdq_core *,
202 struct tpacket3_hdr *);
203static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
204 struct tpacket3_hdr *);
205static void packet_flush_mclist(struct sock *sk);
206static u16 packet_pick_tx_queue(struct sk_buff *skb);
207
208struct packet_skb_cb {
209 union {
210 struct sockaddr_pkt pkt;
211 union {
212 /* Trick: alias skb original length with
213 * ll.sll_family and ll.protocol in order
214 * to save room.
215 */
216 unsigned int origlen;
217 struct sockaddr_ll ll;
218 };
219 } sa;
220};
221
222#define vio_le() virtio_legacy_is_little_endian()
223
224#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
225
226#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
227#define GET_PBLOCK_DESC(x, bid) \
228 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
229#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
230 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
231#define GET_NEXT_PRB_BLK_NUM(x) \
232 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
233 ((x)->kactive_blk_num+1) : 0)
234
235static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
236static void __fanout_link(struct sock *sk, struct packet_sock *po);
237
238static int packet_direct_xmit(struct sk_buff *skb)
239{
240 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
241}
242
243static struct net_device *packet_cached_dev_get(struct packet_sock *po)
244{
245 struct net_device *dev;
246
247 rcu_read_lock();
248 dev = rcu_dereference(po->cached_dev);
249 if (likely(dev))
250 dev_hold(dev);
251 rcu_read_unlock();
252
253 return dev;
254}
255
256static void packet_cached_dev_assign(struct packet_sock *po,
257 struct net_device *dev)
258{
259 rcu_assign_pointer(po->cached_dev, dev);
260}
261
262static void packet_cached_dev_reset(struct packet_sock *po)
263{
264 RCU_INIT_POINTER(po->cached_dev, NULL);
265}
266
267static bool packet_use_direct_xmit(const struct packet_sock *po)
268{
269 return po->xmit == packet_direct_xmit;
270}
271
272static u16 packet_pick_tx_queue(struct sk_buff *skb)
273{
274 struct net_device *dev = skb->dev;
275 const struct net_device_ops *ops = dev->netdev_ops;
276 int cpu = raw_smp_processor_id();
277 u16 queue_index;
278
279#ifdef CONFIG_XPS
280 skb->sender_cpu = cpu + 1;
281#endif
282 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
283 if (ops->ndo_select_queue) {
284 queue_index = ops->ndo_select_queue(dev, skb, NULL);
285 queue_index = netdev_cap_txqueue(dev, queue_index);
286 } else {
287 queue_index = netdev_pick_tx(dev, skb, NULL);
288 }
289
290 return queue_index;
291}
292
293/* __register_prot_hook must be invoked through register_prot_hook
294 * or from a context in which asynchronous accesses to the packet
295 * socket is not possible (packet_create()).
296 */
297static void __register_prot_hook(struct sock *sk)
298{
299 struct packet_sock *po = pkt_sk(sk);
300
301 if (!po->running) {
302 if (po->fanout)
303 __fanout_link(sk, po);
304 else
305 dev_add_pack(&po->prot_hook);
306
307 sock_hold(sk);
308 po->running = 1;
309 }
310}
311
312static void register_prot_hook(struct sock *sk)
313{
314 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
315 __register_prot_hook(sk);
316}
317
318/* If the sync parameter is true, we will temporarily drop
319 * the po->bind_lock and do a synchronize_net to make sure no
320 * asynchronous packet processing paths still refer to the elements
321 * of po->prot_hook. If the sync parameter is false, it is the
322 * callers responsibility to take care of this.
323 */
324static void __unregister_prot_hook(struct sock *sk, bool sync)
325{
326 struct packet_sock *po = pkt_sk(sk);
327
328 lockdep_assert_held_once(&po->bind_lock);
329
330 po->running = 0;
331
332 if (po->fanout)
333 __fanout_unlink(sk, po);
334 else
335 __dev_remove_pack(&po->prot_hook);
336
337 __sock_put(sk);
338
339 if (sync) {
340 spin_unlock(&po->bind_lock);
341 synchronize_net();
342 spin_lock(&po->bind_lock);
343 }
344}
345
346static void unregister_prot_hook(struct sock *sk, bool sync)
347{
348 struct packet_sock *po = pkt_sk(sk);
349
350 if (po->running)
351 __unregister_prot_hook(sk, sync);
352}
353
354static inline struct page * __pure pgv_to_page(void *addr)
355{
356 if (is_vmalloc_addr(addr))
357 return vmalloc_to_page(addr);
358 return virt_to_page(addr);
359}
360
361static void __packet_set_status(struct packet_sock *po, void *frame, int status)
362{
363 union tpacket_uhdr h;
364
365 h.raw = frame;
366 switch (po->tp_version) {
367 case TPACKET_V1:
368 h.h1->tp_status = status;
369 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
370 break;
371 case TPACKET_V2:
372 h.h2->tp_status = status;
373 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
374 break;
375 case TPACKET_V3:
376 h.h3->tp_status = status;
377 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
378 break;
379 default:
380 WARN(1, "TPACKET version not supported.\n");
381 BUG();
382 }
383
384 smp_wmb();
385}
386
387static int __packet_get_status(const struct packet_sock *po, void *frame)
388{
389 union tpacket_uhdr h;
390
391 smp_rmb();
392
393 h.raw = frame;
394 switch (po->tp_version) {
395 case TPACKET_V1:
396 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
397 return h.h1->tp_status;
398 case TPACKET_V2:
399 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
400 return h.h2->tp_status;
401 case TPACKET_V3:
402 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
403 return h.h3->tp_status;
404 default:
405 WARN(1, "TPACKET version not supported.\n");
406 BUG();
407 return 0;
408 }
409}
410
411static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
412 unsigned int flags)
413{
414 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
415
416 if (shhwtstamps &&
417 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
418 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
419 return TP_STATUS_TS_RAW_HARDWARE;
420
421 if (ktime_to_timespec64_cond(skb->tstamp, ts))
422 return TP_STATUS_TS_SOFTWARE;
423
424 return 0;
425}
426
427static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
428 struct sk_buff *skb)
429{
430 union tpacket_uhdr h;
431 struct timespec64 ts;
432 __u32 ts_status;
433
434 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
435 return 0;
436
437 h.raw = frame;
438 /*
439 * versions 1 through 3 overflow the timestamps in y2106, since they
440 * all store the seconds in a 32-bit unsigned integer.
441 * If we create a version 4, that should have a 64-bit timestamp,
442 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
443 * nanoseconds.
444 */
445 switch (po->tp_version) {
446 case TPACKET_V1:
447 h.h1->tp_sec = ts.tv_sec;
448 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
449 break;
450 case TPACKET_V2:
451 h.h2->tp_sec = ts.tv_sec;
452 h.h2->tp_nsec = ts.tv_nsec;
453 break;
454 case TPACKET_V3:
455 h.h3->tp_sec = ts.tv_sec;
456 h.h3->tp_nsec = ts.tv_nsec;
457 break;
458 default:
459 WARN(1, "TPACKET version not supported.\n");
460 BUG();
461 }
462
463 /* one flush is safe, as both fields always lie on the same cacheline */
464 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
465 smp_wmb();
466
467 return ts_status;
468}
469
470static void *packet_lookup_frame(const struct packet_sock *po,
471 const struct packet_ring_buffer *rb,
472 unsigned int position,
473 int status)
474{
475 unsigned int pg_vec_pos, frame_offset;
476 union tpacket_uhdr h;
477
478 pg_vec_pos = position / rb->frames_per_block;
479 frame_offset = position % rb->frames_per_block;
480
481 h.raw = rb->pg_vec[pg_vec_pos].buffer +
482 (frame_offset * rb->frame_size);
483
484 if (status != __packet_get_status(po, h.raw))
485 return NULL;
486
487 return h.raw;
488}
489
490static void *packet_current_frame(struct packet_sock *po,
491 struct packet_ring_buffer *rb,
492 int status)
493{
494 return packet_lookup_frame(po, rb, rb->head, status);
495}
496
497static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
498{
499 del_timer_sync(&pkc->retire_blk_timer);
500}
501
502static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
503 struct sk_buff_head *rb_queue)
504{
505 struct tpacket_kbdq_core *pkc;
506
507 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
508
509 spin_lock_bh(&rb_queue->lock);
510 pkc->delete_blk_timer = 1;
511 spin_unlock_bh(&rb_queue->lock);
512
513 prb_del_retire_blk_timer(pkc);
514}
515
516static void prb_setup_retire_blk_timer(struct packet_sock *po)
517{
518 struct tpacket_kbdq_core *pkc;
519
520 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
521 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
522 0);
523 pkc->retire_blk_timer.expires = jiffies;
524}
525
526static int prb_calc_retire_blk_tmo(struct packet_sock *po,
527 int blk_size_in_bytes)
528{
529 struct net_device *dev;
530 unsigned int mbits, div;
531 struct ethtool_link_ksettings ecmd;
532 int err;
533
534 rtnl_lock();
535 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
536 if (unlikely(!dev)) {
537 rtnl_unlock();
538 return DEFAULT_PRB_RETIRE_TOV;
539 }
540 err = __ethtool_get_link_ksettings(dev, &ecmd);
541 rtnl_unlock();
542 if (err)
543 return DEFAULT_PRB_RETIRE_TOV;
544
545 /* If the link speed is so slow you don't really
546 * need to worry about perf anyways
547 */
548 if (ecmd.base.speed < SPEED_1000 ||
549 ecmd.base.speed == SPEED_UNKNOWN)
550 return DEFAULT_PRB_RETIRE_TOV;
551
552 div = ecmd.base.speed / 1000;
553 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
554
555 if (div)
556 mbits /= div;
557
558 if (div)
559 return mbits + 1;
560 return mbits;
561}
562
563static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
564 union tpacket_req_u *req_u)
565{
566 p1->feature_req_word = req_u->req3.tp_feature_req_word;
567}
568
569static void init_prb_bdqc(struct packet_sock *po,
570 struct packet_ring_buffer *rb,
571 struct pgv *pg_vec,
572 union tpacket_req_u *req_u)
573{
574 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
575 struct tpacket_block_desc *pbd;
576
577 memset(p1, 0x0, sizeof(*p1));
578
579 p1->knxt_seq_num = 1;
580 p1->pkbdq = pg_vec;
581 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
582 p1->pkblk_start = pg_vec[0].buffer;
583 p1->kblk_size = req_u->req3.tp_block_size;
584 p1->knum_blocks = req_u->req3.tp_block_nr;
585 p1->hdrlen = po->tp_hdrlen;
586 p1->version = po->tp_version;
587 p1->last_kactive_blk_num = 0;
588 po->stats.stats3.tp_freeze_q_cnt = 0;
589 if (req_u->req3.tp_retire_blk_tov)
590 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
591 else
592 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
593 req_u->req3.tp_block_size);
594 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
595 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
596 rwlock_init(&p1->blk_fill_in_prog_lock);
597
598 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
599 prb_init_ft_ops(p1, req_u);
600 prb_setup_retire_blk_timer(po);
601 prb_open_block(p1, pbd);
602}
603
604/* Do NOT update the last_blk_num first.
605 * Assumes sk_buff_head lock is held.
606 */
607static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
608{
609 mod_timer(&pkc->retire_blk_timer,
610 jiffies + pkc->tov_in_jiffies);
611 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
612}
613
614/*
615 * Timer logic:
616 * 1) We refresh the timer only when we open a block.
617 * By doing this we don't waste cycles refreshing the timer
618 * on packet-by-packet basis.
619 *
620 * With a 1MB block-size, on a 1Gbps line, it will take
621 * i) ~8 ms to fill a block + ii) memcpy etc.
622 * In this cut we are not accounting for the memcpy time.
623 *
624 * So, if the user sets the 'tmo' to 10ms then the timer
625 * will never fire while the block is still getting filled
626 * (which is what we want). However, the user could choose
627 * to close a block early and that's fine.
628 *
629 * But when the timer does fire, we check whether or not to refresh it.
630 * Since the tmo granularity is in msecs, it is not too expensive
631 * to refresh the timer, lets say every '8' msecs.
632 * Either the user can set the 'tmo' or we can derive it based on
633 * a) line-speed and b) block-size.
634 * prb_calc_retire_blk_tmo() calculates the tmo.
635 *
636 */
637static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
638{
639 struct packet_sock *po =
640 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
641 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
642 unsigned int frozen;
643 struct tpacket_block_desc *pbd;
644
645 spin_lock(&po->sk.sk_receive_queue.lock);
646
647 frozen = prb_queue_frozen(pkc);
648 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
649
650 if (unlikely(pkc->delete_blk_timer))
651 goto out;
652
653 /* We only need to plug the race when the block is partially filled.
654 * tpacket_rcv:
655 * lock(); increment BLOCK_NUM_PKTS; unlock()
656 * copy_bits() is in progress ...
657 * timer fires on other cpu:
658 * we can't retire the current block because copy_bits
659 * is in progress.
660 *
661 */
662 if (BLOCK_NUM_PKTS(pbd)) {
663 /* Waiting for skb_copy_bits to finish... */
664 write_lock(&pkc->blk_fill_in_prog_lock);
665 write_unlock(&pkc->blk_fill_in_prog_lock);
666 }
667
668 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
669 if (!frozen) {
670 if (!BLOCK_NUM_PKTS(pbd)) {
671 /* An empty block. Just refresh the timer. */
672 goto refresh_timer;
673 }
674 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
675 if (!prb_dispatch_next_block(pkc, po))
676 goto refresh_timer;
677 else
678 goto out;
679 } else {
680 /* Case 1. Queue was frozen because user-space was
681 * lagging behind.
682 */
683 if (prb_curr_blk_in_use(pbd)) {
684 /*
685 * Ok, user-space is still behind.
686 * So just refresh the timer.
687 */
688 goto refresh_timer;
689 } else {
690 /* Case 2. queue was frozen,user-space caught up,
691 * now the link went idle && the timer fired.
692 * We don't have a block to close.So we open this
693 * block and restart the timer.
694 * opening a block thaws the queue,restarts timer
695 * Thawing/timer-refresh is a side effect.
696 */
697 prb_open_block(pkc, pbd);
698 goto out;
699 }
700 }
701 }
702
703refresh_timer:
704 _prb_refresh_rx_retire_blk_timer(pkc);
705
706out:
707 spin_unlock(&po->sk.sk_receive_queue.lock);
708}
709
710static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
711 struct tpacket_block_desc *pbd1, __u32 status)
712{
713 /* Flush everything minus the block header */
714
715#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
716 u8 *start, *end;
717
718 start = (u8 *)pbd1;
719
720 /* Skip the block header(we know header WILL fit in 4K) */
721 start += PAGE_SIZE;
722
723 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
724 for (; start < end; start += PAGE_SIZE)
725 flush_dcache_page(pgv_to_page(start));
726
727 smp_wmb();
728#endif
729
730 /* Now update the block status. */
731
732 BLOCK_STATUS(pbd1) = status;
733
734 /* Flush the block header */
735
736#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
737 start = (u8 *)pbd1;
738 flush_dcache_page(pgv_to_page(start));
739
740 smp_wmb();
741#endif
742}
743
744/*
745 * Side effect:
746 *
747 * 1) flush the block
748 * 2) Increment active_blk_num
749 *
750 * Note:We DONT refresh the timer on purpose.
751 * Because almost always the next block will be opened.
752 */
753static void prb_close_block(struct tpacket_kbdq_core *pkc1,
754 struct tpacket_block_desc *pbd1,
755 struct packet_sock *po, unsigned int stat)
756{
757 __u32 status = TP_STATUS_USER | stat;
758
759 struct tpacket3_hdr *last_pkt;
760 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
761 struct sock *sk = &po->sk;
762
763 if (atomic_read(&po->tp_drops))
764 status |= TP_STATUS_LOSING;
765
766 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
767 last_pkt->tp_next_offset = 0;
768
769 /* Get the ts of the last pkt */
770 if (BLOCK_NUM_PKTS(pbd1)) {
771 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
772 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
773 } else {
774 /* Ok, we tmo'd - so get the current time.
775 *
776 * It shouldn't really happen as we don't close empty
777 * blocks. See prb_retire_rx_blk_timer_expired().
778 */
779 struct timespec64 ts;
780 ktime_get_real_ts64(&ts);
781 h1->ts_last_pkt.ts_sec = ts.tv_sec;
782 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
783 }
784
785 smp_wmb();
786
787 /* Flush the block */
788 prb_flush_block(pkc1, pbd1, status);
789
790 sk->sk_data_ready(sk);
791
792 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
793}
794
795static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
796{
797 pkc->reset_pending_on_curr_blk = 0;
798}
799
800/*
801 * Side effect of opening a block:
802 *
803 * 1) prb_queue is thawed.
804 * 2) retire_blk_timer is refreshed.
805 *
806 */
807static void prb_open_block(struct tpacket_kbdq_core *pkc1,
808 struct tpacket_block_desc *pbd1)
809{
810 struct timespec64 ts;
811 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
812
813 smp_rmb();
814
815 /* We could have just memset this but we will lose the
816 * flexibility of making the priv area sticky
817 */
818
819 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
820 BLOCK_NUM_PKTS(pbd1) = 0;
821 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
822
823 ktime_get_real_ts64(&ts);
824
825 h1->ts_first_pkt.ts_sec = ts.tv_sec;
826 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
827
828 pkc1->pkblk_start = (char *)pbd1;
829 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
830
831 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
832 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
833
834 pbd1->version = pkc1->version;
835 pkc1->prev = pkc1->nxt_offset;
836 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
837
838 prb_thaw_queue(pkc1);
839 _prb_refresh_rx_retire_blk_timer(pkc1);
840
841 smp_wmb();
842}
843
844/*
845 * Queue freeze logic:
846 * 1) Assume tp_block_nr = 8 blocks.
847 * 2) At time 't0', user opens Rx ring.
848 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
849 * 4) user-space is either sleeping or processing block '0'.
850 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
851 * it will close block-7,loop around and try to fill block '0'.
852 * call-flow:
853 * __packet_lookup_frame_in_block
854 * prb_retire_current_block()
855 * prb_dispatch_next_block()
856 * |->(BLOCK_STATUS == USER) evaluates to true
857 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
858 * 6) Now there are two cases:
859 * 6.1) Link goes idle right after the queue is frozen.
860 * But remember, the last open_block() refreshed the timer.
861 * When this timer expires,it will refresh itself so that we can
862 * re-open block-0 in near future.
863 * 6.2) Link is busy and keeps on receiving packets. This is a simple
864 * case and __packet_lookup_frame_in_block will check if block-0
865 * is free and can now be re-used.
866 */
867static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
868 struct packet_sock *po)
869{
870 pkc->reset_pending_on_curr_blk = 1;
871 po->stats.stats3.tp_freeze_q_cnt++;
872}
873
874#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
875
876/*
877 * If the next block is free then we will dispatch it
878 * and return a good offset.
879 * Else, we will freeze the queue.
880 * So, caller must check the return value.
881 */
882static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
883 struct packet_sock *po)
884{
885 struct tpacket_block_desc *pbd;
886
887 smp_rmb();
888
889 /* 1. Get current block num */
890 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
891
892 /* 2. If this block is currently in_use then freeze the queue */
893 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
894 prb_freeze_queue(pkc, po);
895 return NULL;
896 }
897
898 /*
899 * 3.
900 * open this block and return the offset where the first packet
901 * needs to get stored.
902 */
903 prb_open_block(pkc, pbd);
904 return (void *)pkc->nxt_offset;
905}
906
907static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
908 struct packet_sock *po, unsigned int status)
909{
910 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
911
912 /* retire/close the current block */
913 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
914 /*
915 * Plug the case where copy_bits() is in progress on
916 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
917 * have space to copy the pkt in the current block and
918 * called prb_retire_current_block()
919 *
920 * We don't need to worry about the TMO case because
921 * the timer-handler already handled this case.
922 */
923 if (!(status & TP_STATUS_BLK_TMO)) {
924 /* Waiting for skb_copy_bits to finish... */
925 write_lock(&pkc->blk_fill_in_prog_lock);
926 write_unlock(&pkc->blk_fill_in_prog_lock);
927 }
928 prb_close_block(pkc, pbd, po, status);
929 return;
930 }
931}
932
933static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
934{
935 return TP_STATUS_USER & BLOCK_STATUS(pbd);
936}
937
938static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
939{
940 return pkc->reset_pending_on_curr_blk;
941}
942
943static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
944 __releases(&pkc->blk_fill_in_prog_lock)
945{
946 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
947
948 read_unlock(&pkc->blk_fill_in_prog_lock);
949}
950
951static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
952 struct tpacket3_hdr *ppd)
953{
954 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
955}
956
957static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
958 struct tpacket3_hdr *ppd)
959{
960 ppd->hv1.tp_rxhash = 0;
961}
962
963static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
964 struct tpacket3_hdr *ppd)
965{
966 if (skb_vlan_tag_present(pkc->skb)) {
967 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
968 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
969 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
970 } else {
971 ppd->hv1.tp_vlan_tci = 0;
972 ppd->hv1.tp_vlan_tpid = 0;
973 ppd->tp_status = TP_STATUS_AVAILABLE;
974 }
975}
976
977static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
978 struct tpacket3_hdr *ppd)
979{
980 ppd->hv1.tp_padding = 0;
981 prb_fill_vlan_info(pkc, ppd);
982
983 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
984 prb_fill_rxhash(pkc, ppd);
985 else
986 prb_clear_rxhash(pkc, ppd);
987}
988
989static void prb_fill_curr_block(char *curr,
990 struct tpacket_kbdq_core *pkc,
991 struct tpacket_block_desc *pbd,
992 unsigned int len)
993 __acquires(&pkc->blk_fill_in_prog_lock)
994{
995 struct tpacket3_hdr *ppd;
996
997 ppd = (struct tpacket3_hdr *)curr;
998 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
999 pkc->prev = curr;
1000 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1001 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1002 BLOCK_NUM_PKTS(pbd) += 1;
1003 read_lock(&pkc->blk_fill_in_prog_lock);
1004 prb_run_all_ft_ops(pkc, ppd);
1005}
1006
1007/* Assumes caller has the sk->rx_queue.lock */
1008static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1009 struct sk_buff *skb,
1010 unsigned int len
1011 )
1012{
1013 struct tpacket_kbdq_core *pkc;
1014 struct tpacket_block_desc *pbd;
1015 char *curr, *end;
1016
1017 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1018 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1019
1020 /* Queue is frozen when user space is lagging behind */
1021 if (prb_queue_frozen(pkc)) {
1022 /*
1023 * Check if that last block which caused the queue to freeze,
1024 * is still in_use by user-space.
1025 */
1026 if (prb_curr_blk_in_use(pbd)) {
1027 /* Can't record this packet */
1028 return NULL;
1029 } else {
1030 /*
1031 * Ok, the block was released by user-space.
1032 * Now let's open that block.
1033 * opening a block also thaws the queue.
1034 * Thawing is a side effect.
1035 */
1036 prb_open_block(pkc, pbd);
1037 }
1038 }
1039
1040 smp_mb();
1041 curr = pkc->nxt_offset;
1042 pkc->skb = skb;
1043 end = (char *)pbd + pkc->kblk_size;
1044
1045 /* first try the current block */
1046 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1047 prb_fill_curr_block(curr, pkc, pbd, len);
1048 return (void *)curr;
1049 }
1050
1051 /* Ok, close the current block */
1052 prb_retire_current_block(pkc, po, 0);
1053
1054 /* Now, try to dispatch the next block */
1055 curr = (char *)prb_dispatch_next_block(pkc, po);
1056 if (curr) {
1057 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1058 prb_fill_curr_block(curr, pkc, pbd, len);
1059 return (void *)curr;
1060 }
1061
1062 /*
1063 * No free blocks are available.user_space hasn't caught up yet.
1064 * Queue was just frozen and now this packet will get dropped.
1065 */
1066 return NULL;
1067}
1068
1069static void *packet_current_rx_frame(struct packet_sock *po,
1070 struct sk_buff *skb,
1071 int status, unsigned int len)
1072{
1073 char *curr = NULL;
1074 switch (po->tp_version) {
1075 case TPACKET_V1:
1076 case TPACKET_V2:
1077 curr = packet_lookup_frame(po, &po->rx_ring,
1078 po->rx_ring.head, status);
1079 return curr;
1080 case TPACKET_V3:
1081 return __packet_lookup_frame_in_block(po, skb, len);
1082 default:
1083 WARN(1, "TPACKET version not supported\n");
1084 BUG();
1085 return NULL;
1086 }
1087}
1088
1089static void *prb_lookup_block(const struct packet_sock *po,
1090 const struct packet_ring_buffer *rb,
1091 unsigned int idx,
1092 int status)
1093{
1094 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1095 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1096
1097 if (status != BLOCK_STATUS(pbd))
1098 return NULL;
1099 return pbd;
1100}
1101
1102static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1103{
1104 unsigned int prev;
1105 if (rb->prb_bdqc.kactive_blk_num)
1106 prev = rb->prb_bdqc.kactive_blk_num-1;
1107 else
1108 prev = rb->prb_bdqc.knum_blocks-1;
1109 return prev;
1110}
1111
1112/* Assumes caller has held the rx_queue.lock */
1113static void *__prb_previous_block(struct packet_sock *po,
1114 struct packet_ring_buffer *rb,
1115 int status)
1116{
1117 unsigned int previous = prb_previous_blk_num(rb);
1118 return prb_lookup_block(po, rb, previous, status);
1119}
1120
1121static void *packet_previous_rx_frame(struct packet_sock *po,
1122 struct packet_ring_buffer *rb,
1123 int status)
1124{
1125 if (po->tp_version <= TPACKET_V2)
1126 return packet_previous_frame(po, rb, status);
1127
1128 return __prb_previous_block(po, rb, status);
1129}
1130
1131static void packet_increment_rx_head(struct packet_sock *po,
1132 struct packet_ring_buffer *rb)
1133{
1134 switch (po->tp_version) {
1135 case TPACKET_V1:
1136 case TPACKET_V2:
1137 return packet_increment_head(rb);
1138 case TPACKET_V3:
1139 default:
1140 WARN(1, "TPACKET version not supported.\n");
1141 BUG();
1142 return;
1143 }
1144}
1145
1146static void *packet_previous_frame(struct packet_sock *po,
1147 struct packet_ring_buffer *rb,
1148 int status)
1149{
1150 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1151 return packet_lookup_frame(po, rb, previous, status);
1152}
1153
1154static void packet_increment_head(struct packet_ring_buffer *buff)
1155{
1156 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1157}
1158
1159static void packet_inc_pending(struct packet_ring_buffer *rb)
1160{
1161 this_cpu_inc(*rb->pending_refcnt);
1162}
1163
1164static void packet_dec_pending(struct packet_ring_buffer *rb)
1165{
1166 this_cpu_dec(*rb->pending_refcnt);
1167}
1168
1169static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1170{
1171 unsigned int refcnt = 0;
1172 int cpu;
1173
1174 /* We don't use pending refcount in rx_ring. */
1175 if (rb->pending_refcnt == NULL)
1176 return 0;
1177
1178 for_each_possible_cpu(cpu)
1179 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1180
1181 return refcnt;
1182}
1183
1184static int packet_alloc_pending(struct packet_sock *po)
1185{
1186 po->rx_ring.pending_refcnt = NULL;
1187
1188 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1189 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1190 return -ENOBUFS;
1191
1192 return 0;
1193}
1194
1195static void packet_free_pending(struct packet_sock *po)
1196{
1197 free_percpu(po->tx_ring.pending_refcnt);
1198}
1199
1200#define ROOM_POW_OFF 2
1201#define ROOM_NONE 0x0
1202#define ROOM_LOW 0x1
1203#define ROOM_NORMAL 0x2
1204
1205static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1206{
1207 int idx, len;
1208
1209 len = READ_ONCE(po->rx_ring.frame_max) + 1;
1210 idx = READ_ONCE(po->rx_ring.head);
1211 if (pow_off)
1212 idx += len >> pow_off;
1213 if (idx >= len)
1214 idx -= len;
1215 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1216}
1217
1218static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1219{
1220 int idx, len;
1221
1222 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1223 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1224 if (pow_off)
1225 idx += len >> pow_off;
1226 if (idx >= len)
1227 idx -= len;
1228 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1229}
1230
1231static int __packet_rcv_has_room(const struct packet_sock *po,
1232 const struct sk_buff *skb)
1233{
1234 const struct sock *sk = &po->sk;
1235 int ret = ROOM_NONE;
1236
1237 if (po->prot_hook.func != tpacket_rcv) {
1238 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1239 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1240 - (skb ? skb->truesize : 0);
1241
1242 if (avail > (rcvbuf >> ROOM_POW_OFF))
1243 return ROOM_NORMAL;
1244 else if (avail > 0)
1245 return ROOM_LOW;
1246 else
1247 return ROOM_NONE;
1248 }
1249
1250 if (po->tp_version == TPACKET_V3) {
1251 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1252 ret = ROOM_NORMAL;
1253 else if (__tpacket_v3_has_room(po, 0))
1254 ret = ROOM_LOW;
1255 } else {
1256 if (__tpacket_has_room(po, ROOM_POW_OFF))
1257 ret = ROOM_NORMAL;
1258 else if (__tpacket_has_room(po, 0))
1259 ret = ROOM_LOW;
1260 }
1261
1262 return ret;
1263}
1264
1265static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1266{
1267 int pressure, ret;
1268
1269 ret = __packet_rcv_has_room(po, skb);
1270 pressure = ret != ROOM_NORMAL;
1271
1272 if (READ_ONCE(po->pressure) != pressure)
1273 WRITE_ONCE(po->pressure, pressure);
1274
1275 return ret;
1276}
1277
1278static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1279{
1280 if (READ_ONCE(po->pressure) &&
1281 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1282 WRITE_ONCE(po->pressure, 0);
1283}
1284
1285static void packet_sock_destruct(struct sock *sk)
1286{
1287 skb_queue_purge(&sk->sk_error_queue);
1288
1289 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1290 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1291
1292 if (!sock_flag(sk, SOCK_DEAD)) {
1293 pr_err("Attempt to release alive packet socket: %p\n", sk);
1294 return;
1295 }
1296
1297 sk_refcnt_debug_dec(sk);
1298}
1299
1300static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1301{
1302 u32 *history = po->rollover->history;
1303 u32 victim, rxhash;
1304 int i, count = 0;
1305
1306 rxhash = skb_get_hash(skb);
1307 for (i = 0; i < ROLLOVER_HLEN; i++)
1308 if (READ_ONCE(history[i]) == rxhash)
1309 count++;
1310
1311 victim = prandom_u32() % ROLLOVER_HLEN;
1312
1313 /* Avoid dirtying the cache line if possible */
1314 if (READ_ONCE(history[victim]) != rxhash)
1315 WRITE_ONCE(history[victim], rxhash);
1316
1317 return count > (ROLLOVER_HLEN >> 1);
1318}
1319
1320static unsigned int fanout_demux_hash(struct packet_fanout *f,
1321 struct sk_buff *skb,
1322 unsigned int num)
1323{
1324 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1325}
1326
1327static unsigned int fanout_demux_lb(struct packet_fanout *f,
1328 struct sk_buff *skb,
1329 unsigned int num)
1330{
1331 unsigned int val = atomic_inc_return(&f->rr_cur);
1332
1333 return val % num;
1334}
1335
1336static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1337 struct sk_buff *skb,
1338 unsigned int num)
1339{
1340 return smp_processor_id() % num;
1341}
1342
1343static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1344 struct sk_buff *skb,
1345 unsigned int num)
1346{
1347 return prandom_u32_max(num);
1348}
1349
1350static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1351 struct sk_buff *skb,
1352 unsigned int idx, bool try_self,
1353 unsigned int num)
1354{
1355 struct packet_sock *po, *po_next, *po_skip = NULL;
1356 unsigned int i, j, room = ROOM_NONE;
1357
1358 po = pkt_sk(f->arr[idx]);
1359
1360 if (try_self) {
1361 room = packet_rcv_has_room(po, skb);
1362 if (room == ROOM_NORMAL ||
1363 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1364 return idx;
1365 po_skip = po;
1366 }
1367
1368 i = j = min_t(int, po->rollover->sock, num - 1);
1369 do {
1370 po_next = pkt_sk(f->arr[i]);
1371 if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1372 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1373 if (i != j)
1374 po->rollover->sock = i;
1375 atomic_long_inc(&po->rollover->num);
1376 if (room == ROOM_LOW)
1377 atomic_long_inc(&po->rollover->num_huge);
1378 return i;
1379 }
1380
1381 if (++i == num)
1382 i = 0;
1383 } while (i != j);
1384
1385 atomic_long_inc(&po->rollover->num_failed);
1386 return idx;
1387}
1388
1389static unsigned int fanout_demux_qm(struct packet_fanout *f,
1390 struct sk_buff *skb,
1391 unsigned int num)
1392{
1393 return skb_get_queue_mapping(skb) % num;
1394}
1395
1396static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1397 struct sk_buff *skb,
1398 unsigned int num)
1399{
1400 struct bpf_prog *prog;
1401 unsigned int ret = 0;
1402
1403 rcu_read_lock();
1404 prog = rcu_dereference(f->bpf_prog);
1405 if (prog)
1406 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1407 rcu_read_unlock();
1408
1409 return ret;
1410}
1411
1412static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1413{
1414 return f->flags & (flag >> 8);
1415}
1416
1417static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1418 struct packet_type *pt, struct net_device *orig_dev)
1419{
1420 struct packet_fanout *f = pt->af_packet_priv;
1421 unsigned int num = READ_ONCE(f->num_members);
1422 struct net *net = read_pnet(&f->net);
1423 struct packet_sock *po;
1424 unsigned int idx;
1425
1426 if (!net_eq(dev_net(dev), net) || !num) {
1427 kfree_skb(skb);
1428 return 0;
1429 }
1430
1431 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1432 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1433 if (!skb)
1434 return 0;
1435 }
1436 switch (f->type) {
1437 case PACKET_FANOUT_HASH:
1438 default:
1439 idx = fanout_demux_hash(f, skb, num);
1440 break;
1441 case PACKET_FANOUT_LB:
1442 idx = fanout_demux_lb(f, skb, num);
1443 break;
1444 case PACKET_FANOUT_CPU:
1445 idx = fanout_demux_cpu(f, skb, num);
1446 break;
1447 case PACKET_FANOUT_RND:
1448 idx = fanout_demux_rnd(f, skb, num);
1449 break;
1450 case PACKET_FANOUT_QM:
1451 idx = fanout_demux_qm(f, skb, num);
1452 break;
1453 case PACKET_FANOUT_ROLLOVER:
1454 idx = fanout_demux_rollover(f, skb, 0, false, num);
1455 break;
1456 case PACKET_FANOUT_CBPF:
1457 case PACKET_FANOUT_EBPF:
1458 idx = fanout_demux_bpf(f, skb, num);
1459 break;
1460 }
1461
1462 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1463 idx = fanout_demux_rollover(f, skb, idx, true, num);
1464
1465 po = pkt_sk(f->arr[idx]);
1466 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1467}
1468
1469DEFINE_MUTEX(fanout_mutex);
1470EXPORT_SYMBOL_GPL(fanout_mutex);
1471static LIST_HEAD(fanout_list);
1472static u16 fanout_next_id;
1473
1474static void __fanout_link(struct sock *sk, struct packet_sock *po)
1475{
1476 struct packet_fanout *f = po->fanout;
1477
1478 spin_lock(&f->lock);
1479 f->arr[f->num_members] = sk;
1480 smp_wmb();
1481 f->num_members++;
1482 if (f->num_members == 1)
1483 dev_add_pack(&f->prot_hook);
1484 spin_unlock(&f->lock);
1485}
1486
1487static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1488{
1489 struct packet_fanout *f = po->fanout;
1490 int i;
1491
1492 spin_lock(&f->lock);
1493 for (i = 0; i < f->num_members; i++) {
1494 if (f->arr[i] == sk)
1495 break;
1496 }
1497 BUG_ON(i >= f->num_members);
1498 f->arr[i] = f->arr[f->num_members - 1];
1499 f->num_members--;
1500 if (f->num_members == 0)
1501 __dev_remove_pack(&f->prot_hook);
1502 spin_unlock(&f->lock);
1503}
1504
1505static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1506{
1507 if (sk->sk_family != PF_PACKET)
1508 return false;
1509
1510 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1511}
1512
1513static void fanout_init_data(struct packet_fanout *f)
1514{
1515 switch (f->type) {
1516 case PACKET_FANOUT_LB:
1517 atomic_set(&f->rr_cur, 0);
1518 break;
1519 case PACKET_FANOUT_CBPF:
1520 case PACKET_FANOUT_EBPF:
1521 RCU_INIT_POINTER(f->bpf_prog, NULL);
1522 break;
1523 }
1524}
1525
1526static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1527{
1528 struct bpf_prog *old;
1529
1530 spin_lock(&f->lock);
1531 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1532 rcu_assign_pointer(f->bpf_prog, new);
1533 spin_unlock(&f->lock);
1534
1535 if (old) {
1536 synchronize_net();
1537 bpf_prog_destroy(old);
1538 }
1539}
1540
1541static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1542 unsigned int len)
1543{
1544 struct bpf_prog *new;
1545 struct sock_fprog fprog;
1546 int ret;
1547
1548 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1549 return -EPERM;
1550
1551 ret = copy_bpf_fprog_from_user(&fprog, data, len);
1552 if (ret)
1553 return ret;
1554
1555 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1556 if (ret)
1557 return ret;
1558
1559 __fanout_set_data_bpf(po->fanout, new);
1560 return 0;
1561}
1562
1563static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1564 unsigned int len)
1565{
1566 struct bpf_prog *new;
1567 u32 fd;
1568
1569 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1570 return -EPERM;
1571 if (len != sizeof(fd))
1572 return -EINVAL;
1573 if (copy_from_sockptr(&fd, data, len))
1574 return -EFAULT;
1575
1576 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1577 if (IS_ERR(new))
1578 return PTR_ERR(new);
1579
1580 __fanout_set_data_bpf(po->fanout, new);
1581 return 0;
1582}
1583
1584static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1585 unsigned int len)
1586{
1587 switch (po->fanout->type) {
1588 case PACKET_FANOUT_CBPF:
1589 return fanout_set_data_cbpf(po, data, len);
1590 case PACKET_FANOUT_EBPF:
1591 return fanout_set_data_ebpf(po, data, len);
1592 default:
1593 return -EINVAL;
1594 }
1595}
1596
1597static void fanout_release_data(struct packet_fanout *f)
1598{
1599 switch (f->type) {
1600 case PACKET_FANOUT_CBPF:
1601 case PACKET_FANOUT_EBPF:
1602 __fanout_set_data_bpf(f, NULL);
1603 }
1604}
1605
1606static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1607{
1608 struct packet_fanout *f;
1609
1610 list_for_each_entry(f, &fanout_list, list) {
1611 if (f->id == candidate_id &&
1612 read_pnet(&f->net) == sock_net(sk)) {
1613 return false;
1614 }
1615 }
1616 return true;
1617}
1618
1619static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1620{
1621 u16 id = fanout_next_id;
1622
1623 do {
1624 if (__fanout_id_is_free(sk, id)) {
1625 *new_id = id;
1626 fanout_next_id = id + 1;
1627 return true;
1628 }
1629
1630 id++;
1631 } while (id != fanout_next_id);
1632
1633 return false;
1634}
1635
1636static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1637{
1638 struct packet_rollover *rollover = NULL;
1639 struct packet_sock *po = pkt_sk(sk);
1640 struct packet_fanout *f, *match;
1641 u8 type = type_flags & 0xff;
1642 u8 flags = type_flags >> 8;
1643 int err;
1644
1645 switch (type) {
1646 case PACKET_FANOUT_ROLLOVER:
1647 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1648 return -EINVAL;
1649 case PACKET_FANOUT_HASH:
1650 case PACKET_FANOUT_LB:
1651 case PACKET_FANOUT_CPU:
1652 case PACKET_FANOUT_RND:
1653 case PACKET_FANOUT_QM:
1654 case PACKET_FANOUT_CBPF:
1655 case PACKET_FANOUT_EBPF:
1656 break;
1657 default:
1658 return -EINVAL;
1659 }
1660
1661 mutex_lock(&fanout_mutex);
1662
1663 err = -EALREADY;
1664 if (po->fanout)
1665 goto out;
1666
1667 if (type == PACKET_FANOUT_ROLLOVER ||
1668 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1669 err = -ENOMEM;
1670 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1671 if (!rollover)
1672 goto out;
1673 atomic_long_set(&rollover->num, 0);
1674 atomic_long_set(&rollover->num_huge, 0);
1675 atomic_long_set(&rollover->num_failed, 0);
1676 }
1677
1678 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1679 if (id != 0) {
1680 err = -EINVAL;
1681 goto out;
1682 }
1683 if (!fanout_find_new_id(sk, &id)) {
1684 err = -ENOMEM;
1685 goto out;
1686 }
1687 /* ephemeral flag for the first socket in the group: drop it */
1688 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1689 }
1690
1691 match = NULL;
1692 list_for_each_entry(f, &fanout_list, list) {
1693 if (f->id == id &&
1694 read_pnet(&f->net) == sock_net(sk)) {
1695 match = f;
1696 break;
1697 }
1698 }
1699 err = -EINVAL;
1700 if (match && match->flags != flags)
1701 goto out;
1702 if (!match) {
1703 err = -ENOMEM;
1704 match = kzalloc(sizeof(*match), GFP_KERNEL);
1705 if (!match)
1706 goto out;
1707 write_pnet(&match->net, sock_net(sk));
1708 match->id = id;
1709 match->type = type;
1710 match->flags = flags;
1711 INIT_LIST_HEAD(&match->list);
1712 spin_lock_init(&match->lock);
1713 refcount_set(&match->sk_ref, 0);
1714 fanout_init_data(match);
1715 match->prot_hook.type = po->prot_hook.type;
1716 match->prot_hook.dev = po->prot_hook.dev;
1717 match->prot_hook.func = packet_rcv_fanout;
1718 match->prot_hook.af_packet_priv = match;
1719 match->prot_hook.id_match = match_fanout_group;
1720 list_add(&match->list, &fanout_list);
1721 }
1722 err = -EINVAL;
1723
1724 spin_lock(&po->bind_lock);
1725 if (po->running &&
1726 match->type == type &&
1727 match->prot_hook.type == po->prot_hook.type &&
1728 match->prot_hook.dev == po->prot_hook.dev) {
1729 err = -ENOSPC;
1730 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1731 __dev_remove_pack(&po->prot_hook);
1732 po->fanout = match;
1733 po->rollover = rollover;
1734 rollover = NULL;
1735 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1736 __fanout_link(sk, po);
1737 err = 0;
1738 }
1739 }
1740 spin_unlock(&po->bind_lock);
1741
1742 if (err && !refcount_read(&match->sk_ref)) {
1743 list_del(&match->list);
1744 kfree(match);
1745 }
1746
1747out:
1748 kfree(rollover);
1749 mutex_unlock(&fanout_mutex);
1750 return err;
1751}
1752
1753/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1754 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1755 * It is the responsibility of the caller to call fanout_release_data() and
1756 * free the returned packet_fanout (after synchronize_net())
1757 */
1758static struct packet_fanout *fanout_release(struct sock *sk)
1759{
1760 struct packet_sock *po = pkt_sk(sk);
1761 struct packet_fanout *f;
1762
1763 mutex_lock(&fanout_mutex);
1764 f = po->fanout;
1765 if (f) {
1766 po->fanout = NULL;
1767
1768 if (refcount_dec_and_test(&f->sk_ref))
1769 list_del(&f->list);
1770 else
1771 f = NULL;
1772 }
1773 mutex_unlock(&fanout_mutex);
1774
1775 return f;
1776}
1777
1778static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1779 struct sk_buff *skb)
1780{
1781 /* Earlier code assumed this would be a VLAN pkt, double-check
1782 * this now that we have the actual packet in hand. We can only
1783 * do this check on Ethernet devices.
1784 */
1785 if (unlikely(dev->type != ARPHRD_ETHER))
1786 return false;
1787
1788 skb_reset_mac_header(skb);
1789 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1790}
1791
1792static const struct proto_ops packet_ops;
1793
1794static const struct proto_ops packet_ops_spkt;
1795
1796static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1797 struct packet_type *pt, struct net_device *orig_dev)
1798{
1799 struct sock *sk;
1800 struct sockaddr_pkt *spkt;
1801
1802 /*
1803 * When we registered the protocol we saved the socket in the data
1804 * field for just this event.
1805 */
1806
1807 sk = pt->af_packet_priv;
1808
1809 /*
1810 * Yank back the headers [hope the device set this
1811 * right or kerboom...]
1812 *
1813 * Incoming packets have ll header pulled,
1814 * push it back.
1815 *
1816 * For outgoing ones skb->data == skb_mac_header(skb)
1817 * so that this procedure is noop.
1818 */
1819
1820 if (skb->pkt_type == PACKET_LOOPBACK)
1821 goto out;
1822
1823 if (!net_eq(dev_net(dev), sock_net(sk)))
1824 goto out;
1825
1826 skb = skb_share_check(skb, GFP_ATOMIC);
1827 if (skb == NULL)
1828 goto oom;
1829
1830 /* drop any routing info */
1831 skb_dst_drop(skb);
1832
1833 /* drop conntrack reference */
1834 nf_reset_ct(skb);
1835
1836 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1837
1838 skb_push(skb, skb->data - skb_mac_header(skb));
1839
1840 /*
1841 * The SOCK_PACKET socket receives _all_ frames.
1842 */
1843
1844 spkt->spkt_family = dev->type;
1845 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1846 spkt->spkt_protocol = skb->protocol;
1847
1848 /*
1849 * Charge the memory to the socket. This is done specifically
1850 * to prevent sockets using all the memory up.
1851 */
1852
1853 if (sock_queue_rcv_skb(sk, skb) == 0)
1854 return 0;
1855
1856out:
1857 kfree_skb(skb);
1858oom:
1859 return 0;
1860}
1861
1862static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1863{
1864 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1865 sock->type == SOCK_RAW) {
1866 skb_reset_mac_header(skb);
1867 skb->protocol = dev_parse_header_protocol(skb);
1868 }
1869
1870 skb_probe_transport_header(skb);
1871}
1872
1873/*
1874 * Output a raw packet to a device layer. This bypasses all the other
1875 * protocol layers and you must therefore supply it with a complete frame
1876 */
1877
1878static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1879 size_t len)
1880{
1881 struct sock *sk = sock->sk;
1882 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1883 struct sk_buff *skb = NULL;
1884 struct net_device *dev;
1885 struct sockcm_cookie sockc;
1886 __be16 proto = 0;
1887 int err;
1888 int extra_len = 0;
1889
1890 /*
1891 * Get and verify the address.
1892 */
1893
1894 if (saddr) {
1895 if (msg->msg_namelen < sizeof(struct sockaddr))
1896 return -EINVAL;
1897 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1898 proto = saddr->spkt_protocol;
1899 } else
1900 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1901
1902 /*
1903 * Find the device first to size check it
1904 */
1905
1906 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1907retry:
1908 rcu_read_lock();
1909 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1910 err = -ENODEV;
1911 if (dev == NULL)
1912 goto out_unlock;
1913
1914 err = -ENETDOWN;
1915 if (!(dev->flags & IFF_UP))
1916 goto out_unlock;
1917
1918 /*
1919 * You may not queue a frame bigger than the mtu. This is the lowest level
1920 * raw protocol and you must do your own fragmentation at this level.
1921 */
1922
1923 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1924 if (!netif_supports_nofcs(dev)) {
1925 err = -EPROTONOSUPPORT;
1926 goto out_unlock;
1927 }
1928 extra_len = 4; /* We're doing our own CRC */
1929 }
1930
1931 err = -EMSGSIZE;
1932 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1933 goto out_unlock;
1934
1935 if (!skb) {
1936 size_t reserved = LL_RESERVED_SPACE(dev);
1937 int tlen = dev->needed_tailroom;
1938 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1939
1940 rcu_read_unlock();
1941 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1942 if (skb == NULL)
1943 return -ENOBUFS;
1944 /* FIXME: Save some space for broken drivers that write a hard
1945 * header at transmission time by themselves. PPP is the notable
1946 * one here. This should really be fixed at the driver level.
1947 */
1948 skb_reserve(skb, reserved);
1949 skb_reset_network_header(skb);
1950
1951 /* Try to align data part correctly */
1952 if (hhlen) {
1953 skb->data -= hhlen;
1954 skb->tail -= hhlen;
1955 if (len < hhlen)
1956 skb_reset_network_header(skb);
1957 }
1958 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1959 if (err)
1960 goto out_free;
1961 goto retry;
1962 }
1963
1964 if (!dev_validate_header(dev, skb->data, len)) {
1965 err = -EINVAL;
1966 goto out_unlock;
1967 }
1968 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1969 !packet_extra_vlan_len_allowed(dev, skb)) {
1970 err = -EMSGSIZE;
1971 goto out_unlock;
1972 }
1973
1974 sockcm_init(&sockc, sk);
1975 if (msg->msg_controllen) {
1976 err = sock_cmsg_send(sk, msg, &sockc);
1977 if (unlikely(err))
1978 goto out_unlock;
1979 }
1980
1981 skb->protocol = proto;
1982 skb->dev = dev;
1983 skb->priority = sk->sk_priority;
1984 skb->mark = sk->sk_mark;
1985 skb->tstamp = sockc.transmit_time;
1986
1987 skb_setup_tx_timestamp(skb, sockc.tsflags);
1988
1989 if (unlikely(extra_len == 4))
1990 skb->no_fcs = 1;
1991
1992 packet_parse_headers(skb, sock);
1993
1994 dev_queue_xmit(skb);
1995 rcu_read_unlock();
1996 return len;
1997
1998out_unlock:
1999 rcu_read_unlock();
2000out_free:
2001 kfree_skb(skb);
2002 return err;
2003}
2004
2005static unsigned int run_filter(struct sk_buff *skb,
2006 const struct sock *sk,
2007 unsigned int res)
2008{
2009 struct sk_filter *filter;
2010
2011 rcu_read_lock();
2012 filter = rcu_dereference(sk->sk_filter);
2013 if (filter != NULL)
2014 res = bpf_prog_run_clear_cb(filter->prog, skb);
2015 rcu_read_unlock();
2016
2017 return res;
2018}
2019
2020static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2021 size_t *len)
2022{
2023 struct virtio_net_hdr vnet_hdr;
2024
2025 if (*len < sizeof(vnet_hdr))
2026 return -EINVAL;
2027 *len -= sizeof(vnet_hdr);
2028
2029 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2030 return -EINVAL;
2031
2032 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2033}
2034
2035/*
2036 * This function makes lazy skb cloning in hope that most of packets
2037 * are discarded by BPF.
2038 *
2039 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2040 * and skb->cb are mangled. It works because (and until) packets
2041 * falling here are owned by current CPU. Output packets are cloned
2042 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2043 * sequencially, so that if we return skb to original state on exit,
2044 * we will not harm anyone.
2045 */
2046
2047static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2048 struct packet_type *pt, struct net_device *orig_dev)
2049{
2050 struct sock *sk;
2051 struct sockaddr_ll *sll;
2052 struct packet_sock *po;
2053 u8 *skb_head = skb->data;
2054 int skb_len = skb->len;
2055 unsigned int snaplen, res;
2056 bool is_drop_n_account = false;
2057
2058 if (skb->pkt_type == PACKET_LOOPBACK)
2059 goto drop;
2060
2061 sk = pt->af_packet_priv;
2062 po = pkt_sk(sk);
2063
2064 if (!net_eq(dev_net(dev), sock_net(sk)))
2065 goto drop;
2066
2067 skb->dev = dev;
2068
2069 if (dev->header_ops) {
2070 /* The device has an explicit notion of ll header,
2071 * exported to higher levels.
2072 *
2073 * Otherwise, the device hides details of its frame
2074 * structure, so that corresponding packet head is
2075 * never delivered to user.
2076 */
2077 if (sk->sk_type != SOCK_DGRAM)
2078 skb_push(skb, skb->data - skb_mac_header(skb));
2079 else if (skb->pkt_type == PACKET_OUTGOING) {
2080 /* Special case: outgoing packets have ll header at head */
2081 skb_pull(skb, skb_network_offset(skb));
2082 }
2083 }
2084
2085 snaplen = skb->len;
2086
2087 res = run_filter(skb, sk, snaplen);
2088 if (!res)
2089 goto drop_n_restore;
2090 if (snaplen > res)
2091 snaplen = res;
2092
2093 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2094 goto drop_n_acct;
2095
2096 if (skb_shared(skb)) {
2097 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2098 if (nskb == NULL)
2099 goto drop_n_acct;
2100
2101 if (skb_head != skb->data) {
2102 skb->data = skb_head;
2103 skb->len = skb_len;
2104 }
2105 consume_skb(skb);
2106 skb = nskb;
2107 }
2108
2109 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2110
2111 sll = &PACKET_SKB_CB(skb)->sa.ll;
2112 sll->sll_hatype = dev->type;
2113 sll->sll_pkttype = skb->pkt_type;
2114 if (unlikely(po->origdev))
2115 sll->sll_ifindex = orig_dev->ifindex;
2116 else
2117 sll->sll_ifindex = dev->ifindex;
2118
2119 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2120
2121 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2122 * Use their space for storing the original skb length.
2123 */
2124 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2125
2126 if (pskb_trim(skb, snaplen))
2127 goto drop_n_acct;
2128
2129 skb_set_owner_r(skb, sk);
2130 skb->dev = NULL;
2131 skb_dst_drop(skb);
2132
2133 /* drop conntrack reference */
2134 nf_reset_ct(skb);
2135
2136 spin_lock(&sk->sk_receive_queue.lock);
2137 po->stats.stats1.tp_packets++;
2138 sock_skb_set_dropcount(sk, skb);
2139 __skb_queue_tail(&sk->sk_receive_queue, skb);
2140 spin_unlock(&sk->sk_receive_queue.lock);
2141 sk->sk_data_ready(sk);
2142 return 0;
2143
2144drop_n_acct:
2145 is_drop_n_account = true;
2146 atomic_inc(&po->tp_drops);
2147 atomic_inc(&sk->sk_drops);
2148
2149drop_n_restore:
2150 if (skb_head != skb->data && skb_shared(skb)) {
2151 skb->data = skb_head;
2152 skb->len = skb_len;
2153 }
2154drop:
2155 if (!is_drop_n_account)
2156 consume_skb(skb);
2157 else
2158 kfree_skb(skb);
2159 return 0;
2160}
2161
2162static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2163 struct packet_type *pt, struct net_device *orig_dev)
2164{
2165 struct sock *sk;
2166 struct packet_sock *po;
2167 struct sockaddr_ll *sll;
2168 union tpacket_uhdr h;
2169 u8 *skb_head = skb->data;
2170 int skb_len = skb->len;
2171 unsigned int snaplen, res;
2172 unsigned long status = TP_STATUS_USER;
2173 unsigned short macoff, hdrlen;
2174 unsigned int netoff;
2175 struct sk_buff *copy_skb = NULL;
2176 struct timespec64 ts;
2177 __u32 ts_status;
2178 bool is_drop_n_account = false;
2179 unsigned int slot_id = 0;
2180 bool do_vnet = false;
2181
2182 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2183 * We may add members to them until current aligned size without forcing
2184 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2185 */
2186 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2187 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2188
2189 if (skb->pkt_type == PACKET_LOOPBACK)
2190 goto drop;
2191
2192 sk = pt->af_packet_priv;
2193 po = pkt_sk(sk);
2194
2195 if (!net_eq(dev_net(dev), sock_net(sk)))
2196 goto drop;
2197
2198 if (dev->header_ops) {
2199 if (sk->sk_type != SOCK_DGRAM)
2200 skb_push(skb, skb->data - skb_mac_header(skb));
2201 else if (skb->pkt_type == PACKET_OUTGOING) {
2202 /* Special case: outgoing packets have ll header at head */
2203 skb_pull(skb, skb_network_offset(skb));
2204 }
2205 }
2206
2207 snaplen = skb->len;
2208
2209 res = run_filter(skb, sk, snaplen);
2210 if (!res)
2211 goto drop_n_restore;
2212
2213 /* If we are flooded, just give up */
2214 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2215 atomic_inc(&po->tp_drops);
2216 goto drop_n_restore;
2217 }
2218
2219 if (skb->ip_summed == CHECKSUM_PARTIAL)
2220 status |= TP_STATUS_CSUMNOTREADY;
2221 else if (skb->pkt_type != PACKET_OUTGOING &&
2222 (skb->ip_summed == CHECKSUM_COMPLETE ||
2223 skb_csum_unnecessary(skb)))
2224 status |= TP_STATUS_CSUM_VALID;
2225
2226 if (snaplen > res)
2227 snaplen = res;
2228
2229 if (sk->sk_type == SOCK_DGRAM) {
2230 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2231 po->tp_reserve;
2232 } else {
2233 unsigned int maclen = skb_network_offset(skb);
2234 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2235 (maclen < 16 ? 16 : maclen)) +
2236 po->tp_reserve;
2237 if (po->has_vnet_hdr) {
2238 netoff += sizeof(struct virtio_net_hdr);
2239 do_vnet = true;
2240 }
2241 macoff = netoff - maclen;
2242 }
2243 if (netoff > USHRT_MAX) {
2244 atomic_inc(&po->tp_drops);
2245 goto drop_n_restore;
2246 }
2247 if (po->tp_version <= TPACKET_V2) {
2248 if (macoff + snaplen > po->rx_ring.frame_size) {
2249 if (po->copy_thresh &&
2250 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2251 if (skb_shared(skb)) {
2252 copy_skb = skb_clone(skb, GFP_ATOMIC);
2253 } else {
2254 copy_skb = skb_get(skb);
2255 skb_head = skb->data;
2256 }
2257 if (copy_skb)
2258 skb_set_owner_r(copy_skb, sk);
2259 }
2260 snaplen = po->rx_ring.frame_size - macoff;
2261 if ((int)snaplen < 0) {
2262 snaplen = 0;
2263 do_vnet = false;
2264 }
2265 }
2266 } else if (unlikely(macoff + snaplen >
2267 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2268 u32 nval;
2269
2270 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2271 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2272 snaplen, nval, macoff);
2273 snaplen = nval;
2274 if (unlikely((int)snaplen < 0)) {
2275 snaplen = 0;
2276 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2277 do_vnet = false;
2278 }
2279 }
2280 spin_lock(&sk->sk_receive_queue.lock);
2281 h.raw = packet_current_rx_frame(po, skb,
2282 TP_STATUS_KERNEL, (macoff+snaplen));
2283 if (!h.raw)
2284 goto drop_n_account;
2285
2286 if (po->tp_version <= TPACKET_V2) {
2287 slot_id = po->rx_ring.head;
2288 if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2289 goto drop_n_account;
2290 __set_bit(slot_id, po->rx_ring.rx_owner_map);
2291 }
2292
2293 if (do_vnet &&
2294 virtio_net_hdr_from_skb(skb, h.raw + macoff -
2295 sizeof(struct virtio_net_hdr),
2296 vio_le(), true, 0)) {
2297 if (po->tp_version == TPACKET_V3)
2298 prb_clear_blk_fill_status(&po->rx_ring);
2299 goto drop_n_account;
2300 }
2301
2302 if (po->tp_version <= TPACKET_V2) {
2303 packet_increment_rx_head(po, &po->rx_ring);
2304 /*
2305 * LOSING will be reported till you read the stats,
2306 * because it's COR - Clear On Read.
2307 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2308 * at packet level.
2309 */
2310 if (atomic_read(&po->tp_drops))
2311 status |= TP_STATUS_LOSING;
2312 }
2313
2314 po->stats.stats1.tp_packets++;
2315 if (copy_skb) {
2316 status |= TP_STATUS_COPY;
2317 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2318 }
2319 spin_unlock(&sk->sk_receive_queue.lock);
2320
2321 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2322
2323 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2324 ktime_get_real_ts64(&ts);
2325
2326 status |= ts_status;
2327
2328 switch (po->tp_version) {
2329 case TPACKET_V1:
2330 h.h1->tp_len = skb->len;
2331 h.h1->tp_snaplen = snaplen;
2332 h.h1->tp_mac = macoff;
2333 h.h1->tp_net = netoff;
2334 h.h1->tp_sec = ts.tv_sec;
2335 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2336 hdrlen = sizeof(*h.h1);
2337 break;
2338 case TPACKET_V2:
2339 h.h2->tp_len = skb->len;
2340 h.h2->tp_snaplen = snaplen;
2341 h.h2->tp_mac = macoff;
2342 h.h2->tp_net = netoff;
2343 h.h2->tp_sec = ts.tv_sec;
2344 h.h2->tp_nsec = ts.tv_nsec;
2345 if (skb_vlan_tag_present(skb)) {
2346 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2347 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2348 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2349 } else {
2350 h.h2->tp_vlan_tci = 0;
2351 h.h2->tp_vlan_tpid = 0;
2352 }
2353 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2354 hdrlen = sizeof(*h.h2);
2355 break;
2356 case TPACKET_V3:
2357 /* tp_nxt_offset,vlan are already populated above.
2358 * So DONT clear those fields here
2359 */
2360 h.h3->tp_status |= status;
2361 h.h3->tp_len = skb->len;
2362 h.h3->tp_snaplen = snaplen;
2363 h.h3->tp_mac = macoff;
2364 h.h3->tp_net = netoff;
2365 h.h3->tp_sec = ts.tv_sec;
2366 h.h3->tp_nsec = ts.tv_nsec;
2367 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2368 hdrlen = sizeof(*h.h3);
2369 break;
2370 default:
2371 BUG();
2372 }
2373
2374 sll = h.raw + TPACKET_ALIGN(hdrlen);
2375 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2376 sll->sll_family = AF_PACKET;
2377 sll->sll_hatype = dev->type;
2378 sll->sll_protocol = skb->protocol;
2379 sll->sll_pkttype = skb->pkt_type;
2380 if (unlikely(po->origdev))
2381 sll->sll_ifindex = orig_dev->ifindex;
2382 else
2383 sll->sll_ifindex = dev->ifindex;
2384
2385 smp_mb();
2386
2387#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2388 if (po->tp_version <= TPACKET_V2) {
2389 u8 *start, *end;
2390
2391 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2392 macoff + snaplen);
2393
2394 for (start = h.raw; start < end; start += PAGE_SIZE)
2395 flush_dcache_page(pgv_to_page(start));
2396 }
2397 smp_wmb();
2398#endif
2399
2400 if (po->tp_version <= TPACKET_V2) {
2401 spin_lock(&sk->sk_receive_queue.lock);
2402 __packet_set_status(po, h.raw, status);
2403 __clear_bit(slot_id, po->rx_ring.rx_owner_map);
2404 spin_unlock(&sk->sk_receive_queue.lock);
2405 sk->sk_data_ready(sk);
2406 } else if (po->tp_version == TPACKET_V3) {
2407 prb_clear_blk_fill_status(&po->rx_ring);
2408 }
2409
2410drop_n_restore:
2411 if (skb_head != skb->data && skb_shared(skb)) {
2412 skb->data = skb_head;
2413 skb->len = skb_len;
2414 }
2415drop:
2416 if (!is_drop_n_account)
2417 consume_skb(skb);
2418 else
2419 kfree_skb(skb);
2420 return 0;
2421
2422drop_n_account:
2423 spin_unlock(&sk->sk_receive_queue.lock);
2424 atomic_inc(&po->tp_drops);
2425 is_drop_n_account = true;
2426
2427 sk->sk_data_ready(sk);
2428 kfree_skb(copy_skb);
2429 goto drop_n_restore;
2430}
2431
2432static void tpacket_destruct_skb(struct sk_buff *skb)
2433{
2434 struct packet_sock *po = pkt_sk(skb->sk);
2435
2436 if (likely(po->tx_ring.pg_vec)) {
2437 void *ph;
2438 __u32 ts;
2439
2440 ph = skb_zcopy_get_nouarg(skb);
2441 packet_dec_pending(&po->tx_ring);
2442
2443 ts = __packet_set_timestamp(po, ph, skb);
2444 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2445
2446 if (!packet_read_pending(&po->tx_ring))
2447 complete(&po->skb_completion);
2448 }
2449
2450 sock_wfree(skb);
2451}
2452
2453static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2454{
2455 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2456 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2457 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2458 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2459 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2460 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2461 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2462
2463 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2464 return -EINVAL;
2465
2466 return 0;
2467}
2468
2469static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2470 struct virtio_net_hdr *vnet_hdr)
2471{
2472 if (*len < sizeof(*vnet_hdr))
2473 return -EINVAL;
2474 *len -= sizeof(*vnet_hdr);
2475
2476 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2477 return -EFAULT;
2478
2479 return __packet_snd_vnet_parse(vnet_hdr, *len);
2480}
2481
2482static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2483 void *frame, struct net_device *dev, void *data, int tp_len,
2484 __be16 proto, unsigned char *addr, int hlen, int copylen,
2485 const struct sockcm_cookie *sockc)
2486{
2487 union tpacket_uhdr ph;
2488 int to_write, offset, len, nr_frags, len_max;
2489 struct socket *sock = po->sk.sk_socket;
2490 struct page *page;
2491 int err;
2492
2493 ph.raw = frame;
2494
2495 skb->protocol = proto;
2496 skb->dev = dev;
2497 skb->priority = po->sk.sk_priority;
2498 skb->mark = po->sk.sk_mark;
2499 skb->tstamp = sockc->transmit_time;
2500 skb_setup_tx_timestamp(skb, sockc->tsflags);
2501 skb_zcopy_set_nouarg(skb, ph.raw);
2502
2503 skb_reserve(skb, hlen);
2504 skb_reset_network_header(skb);
2505
2506 to_write = tp_len;
2507
2508 if (sock->type == SOCK_DGRAM) {
2509 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2510 NULL, tp_len);
2511 if (unlikely(err < 0))
2512 return -EINVAL;
2513 } else if (copylen) {
2514 int hdrlen = min_t(int, copylen, tp_len);
2515
2516 skb_push(skb, dev->hard_header_len);
2517 skb_put(skb, copylen - dev->hard_header_len);
2518 err = skb_store_bits(skb, 0, data, hdrlen);
2519 if (unlikely(err))
2520 return err;
2521 if (!dev_validate_header(dev, skb->data, hdrlen))
2522 return -EINVAL;
2523
2524 data += hdrlen;
2525 to_write -= hdrlen;
2526 }
2527
2528 offset = offset_in_page(data);
2529 len_max = PAGE_SIZE - offset;
2530 len = ((to_write > len_max) ? len_max : to_write);
2531
2532 skb->data_len = to_write;
2533 skb->len += to_write;
2534 skb->truesize += to_write;
2535 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2536
2537 while (likely(to_write)) {
2538 nr_frags = skb_shinfo(skb)->nr_frags;
2539
2540 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2541 pr_err("Packet exceed the number of skb frags(%lu)\n",
2542 MAX_SKB_FRAGS);
2543 return -EFAULT;
2544 }
2545
2546 page = pgv_to_page(data);
2547 data += len;
2548 flush_dcache_page(page);
2549 get_page(page);
2550 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2551 to_write -= len;
2552 offset = 0;
2553 len_max = PAGE_SIZE;
2554 len = ((to_write > len_max) ? len_max : to_write);
2555 }
2556
2557 packet_parse_headers(skb, sock);
2558
2559 return tp_len;
2560}
2561
2562static int tpacket_parse_header(struct packet_sock *po, void *frame,
2563 int size_max, void **data)
2564{
2565 union tpacket_uhdr ph;
2566 int tp_len, off;
2567
2568 ph.raw = frame;
2569
2570 switch (po->tp_version) {
2571 case TPACKET_V3:
2572 if (ph.h3->tp_next_offset != 0) {
2573 pr_warn_once("variable sized slot not supported");
2574 return -EINVAL;
2575 }
2576 tp_len = ph.h3->tp_len;
2577 break;
2578 case TPACKET_V2:
2579 tp_len = ph.h2->tp_len;
2580 break;
2581 default:
2582 tp_len = ph.h1->tp_len;
2583 break;
2584 }
2585 if (unlikely(tp_len > size_max)) {
2586 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2587 return -EMSGSIZE;
2588 }
2589
2590 if (unlikely(po->tp_tx_has_off)) {
2591 int off_min, off_max;
2592
2593 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2594 off_max = po->tx_ring.frame_size - tp_len;
2595 if (po->sk.sk_type == SOCK_DGRAM) {
2596 switch (po->tp_version) {
2597 case TPACKET_V3:
2598 off = ph.h3->tp_net;
2599 break;
2600 case TPACKET_V2:
2601 off = ph.h2->tp_net;
2602 break;
2603 default:
2604 off = ph.h1->tp_net;
2605 break;
2606 }
2607 } else {
2608 switch (po->tp_version) {
2609 case TPACKET_V3:
2610 off = ph.h3->tp_mac;
2611 break;
2612 case TPACKET_V2:
2613 off = ph.h2->tp_mac;
2614 break;
2615 default:
2616 off = ph.h1->tp_mac;
2617 break;
2618 }
2619 }
2620 if (unlikely((off < off_min) || (off_max < off)))
2621 return -EINVAL;
2622 } else {
2623 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2624 }
2625
2626 *data = frame + off;
2627 return tp_len;
2628}
2629
2630static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2631{
2632 struct sk_buff *skb = NULL;
2633 struct net_device *dev;
2634 struct virtio_net_hdr *vnet_hdr = NULL;
2635 struct sockcm_cookie sockc;
2636 __be16 proto;
2637 int err, reserve = 0;
2638 void *ph;
2639 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2640 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2641 unsigned char *addr = NULL;
2642 int tp_len, size_max;
2643 void *data;
2644 int len_sum = 0;
2645 int status = TP_STATUS_AVAILABLE;
2646 int hlen, tlen, copylen = 0;
2647 long timeo = 0;
2648
2649 mutex_lock(&po->pg_vec_lock);
2650
2651 /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2652 * we need to confirm it under protection of pg_vec_lock.
2653 */
2654 if (unlikely(!po->tx_ring.pg_vec)) {
2655 err = -EBUSY;
2656 goto out;
2657 }
2658 if (likely(saddr == NULL)) {
2659 dev = packet_cached_dev_get(po);
2660 proto = po->num;
2661 } else {
2662 err = -EINVAL;
2663 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2664 goto out;
2665 if (msg->msg_namelen < (saddr->sll_halen
2666 + offsetof(struct sockaddr_ll,
2667 sll_addr)))
2668 goto out;
2669 proto = saddr->sll_protocol;
2670 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2671 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2672 if (dev && msg->msg_namelen < dev->addr_len +
2673 offsetof(struct sockaddr_ll, sll_addr))
2674 goto out_put;
2675 addr = saddr->sll_addr;
2676 }
2677 }
2678
2679 err = -ENXIO;
2680 if (unlikely(dev == NULL))
2681 goto out;
2682 err = -ENETDOWN;
2683 if (unlikely(!(dev->flags & IFF_UP)))
2684 goto out_put;
2685
2686 sockcm_init(&sockc, &po->sk);
2687 if (msg->msg_controllen) {
2688 err = sock_cmsg_send(&po->sk, msg, &sockc);
2689 if (unlikely(err))
2690 goto out_put;
2691 }
2692
2693 if (po->sk.sk_socket->type == SOCK_RAW)
2694 reserve = dev->hard_header_len;
2695 size_max = po->tx_ring.frame_size
2696 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2697
2698 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2699 size_max = dev->mtu + reserve + VLAN_HLEN;
2700
2701 reinit_completion(&po->skb_completion);
2702
2703 do {
2704 ph = packet_current_frame(po, &po->tx_ring,
2705 TP_STATUS_SEND_REQUEST);
2706 if (unlikely(ph == NULL)) {
2707 if (need_wait && skb) {
2708 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2709 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2710 if (timeo <= 0) {
2711 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2712 goto out_put;
2713 }
2714 }
2715 /* check for additional frames */
2716 continue;
2717 }
2718
2719 skb = NULL;
2720 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2721 if (tp_len < 0)
2722 goto tpacket_error;
2723
2724 status = TP_STATUS_SEND_REQUEST;
2725 hlen = LL_RESERVED_SPACE(dev);
2726 tlen = dev->needed_tailroom;
2727 if (po->has_vnet_hdr) {
2728 vnet_hdr = data;
2729 data += sizeof(*vnet_hdr);
2730 tp_len -= sizeof(*vnet_hdr);
2731 if (tp_len < 0 ||
2732 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2733 tp_len = -EINVAL;
2734 goto tpacket_error;
2735 }
2736 copylen = __virtio16_to_cpu(vio_le(),
2737 vnet_hdr->hdr_len);
2738 }
2739 copylen = max_t(int, copylen, dev->hard_header_len);
2740 skb = sock_alloc_send_skb(&po->sk,
2741 hlen + tlen + sizeof(struct sockaddr_ll) +
2742 (copylen - dev->hard_header_len),
2743 !need_wait, &err);
2744
2745 if (unlikely(skb == NULL)) {
2746 /* we assume the socket was initially writeable ... */
2747 if (likely(len_sum > 0))
2748 err = len_sum;
2749 goto out_status;
2750 }
2751 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2752 addr, hlen, copylen, &sockc);
2753 if (likely(tp_len >= 0) &&
2754 tp_len > dev->mtu + reserve &&
2755 !po->has_vnet_hdr &&
2756 !packet_extra_vlan_len_allowed(dev, skb))
2757 tp_len = -EMSGSIZE;
2758
2759 if (unlikely(tp_len < 0)) {
2760tpacket_error:
2761 if (po->tp_loss) {
2762 __packet_set_status(po, ph,
2763 TP_STATUS_AVAILABLE);
2764 packet_increment_head(&po->tx_ring);
2765 kfree_skb(skb);
2766 continue;
2767 } else {
2768 status = TP_STATUS_WRONG_FORMAT;
2769 err = tp_len;
2770 goto out_status;
2771 }
2772 }
2773
2774 if (po->has_vnet_hdr) {
2775 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2776 tp_len = -EINVAL;
2777 goto tpacket_error;
2778 }
2779 virtio_net_hdr_set_proto(skb, vnet_hdr);
2780 }
2781
2782 skb->destructor = tpacket_destruct_skb;
2783 __packet_set_status(po, ph, TP_STATUS_SENDING);
2784 packet_inc_pending(&po->tx_ring);
2785
2786 status = TP_STATUS_SEND_REQUEST;
2787 err = po->xmit(skb);
2788 if (unlikely(err > 0)) {
2789 err = net_xmit_errno(err);
2790 if (err && __packet_get_status(po, ph) ==
2791 TP_STATUS_AVAILABLE) {
2792 /* skb was destructed already */
2793 skb = NULL;
2794 goto out_status;
2795 }
2796 /*
2797 * skb was dropped but not destructed yet;
2798 * let's treat it like congestion or err < 0
2799 */
2800 err = 0;
2801 }
2802 packet_increment_head(&po->tx_ring);
2803 len_sum += tp_len;
2804 } while (likely((ph != NULL) ||
2805 /* Note: packet_read_pending() might be slow if we have
2806 * to call it as it's per_cpu variable, but in fast-path
2807 * we already short-circuit the loop with the first
2808 * condition, and luckily don't have to go that path
2809 * anyway.
2810 */
2811 (need_wait && packet_read_pending(&po->tx_ring))));
2812
2813 err = len_sum;
2814 goto out_put;
2815
2816out_status:
2817 __packet_set_status(po, ph, status);
2818 kfree_skb(skb);
2819out_put:
2820 dev_put(dev);
2821out:
2822 mutex_unlock(&po->pg_vec_lock);
2823 return err;
2824}
2825
2826static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2827 size_t reserve, size_t len,
2828 size_t linear, int noblock,
2829 int *err)
2830{
2831 struct sk_buff *skb;
2832
2833 /* Under a page? Don't bother with paged skb. */
2834 if (prepad + len < PAGE_SIZE || !linear)
2835 linear = len;
2836
2837 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2838 err, 0);
2839 if (!skb)
2840 return NULL;
2841
2842 skb_reserve(skb, reserve);
2843 skb_put(skb, linear);
2844 skb->data_len = len - linear;
2845 skb->len += len - linear;
2846
2847 return skb;
2848}
2849
2850static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2851{
2852 struct sock *sk = sock->sk;
2853 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2854 struct sk_buff *skb;
2855 struct net_device *dev;
2856 __be16 proto;
2857 unsigned char *addr = NULL;
2858 int err, reserve = 0;
2859 struct sockcm_cookie sockc;
2860 struct virtio_net_hdr vnet_hdr = { 0 };
2861 int offset = 0;
2862 struct packet_sock *po = pkt_sk(sk);
2863 bool has_vnet_hdr = false;
2864 int hlen, tlen, linear;
2865 int extra_len = 0;
2866
2867 /*
2868 * Get and verify the address.
2869 */
2870
2871 if (likely(saddr == NULL)) {
2872 dev = packet_cached_dev_get(po);
2873 proto = po->num;
2874 } else {
2875 err = -EINVAL;
2876 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2877 goto out;
2878 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2879 goto out;
2880 proto = saddr->sll_protocol;
2881 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2882 if (sock->type == SOCK_DGRAM) {
2883 if (dev && msg->msg_namelen < dev->addr_len +
2884 offsetof(struct sockaddr_ll, sll_addr))
2885 goto out_unlock;
2886 addr = saddr->sll_addr;
2887 }
2888 }
2889
2890 err = -ENXIO;
2891 if (unlikely(dev == NULL))
2892 goto out_unlock;
2893 err = -ENETDOWN;
2894 if (unlikely(!(dev->flags & IFF_UP)))
2895 goto out_unlock;
2896
2897 sockcm_init(&sockc, sk);
2898 sockc.mark = sk->sk_mark;
2899 if (msg->msg_controllen) {
2900 err = sock_cmsg_send(sk, msg, &sockc);
2901 if (unlikely(err))
2902 goto out_unlock;
2903 }
2904
2905 if (sock->type == SOCK_RAW)
2906 reserve = dev->hard_header_len;
2907 if (po->has_vnet_hdr) {
2908 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2909 if (err)
2910 goto out_unlock;
2911 has_vnet_hdr = true;
2912 }
2913
2914 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2915 if (!netif_supports_nofcs(dev)) {
2916 err = -EPROTONOSUPPORT;
2917 goto out_unlock;
2918 }
2919 extra_len = 4; /* We're doing our own CRC */
2920 }
2921
2922 err = -EMSGSIZE;
2923 if (!vnet_hdr.gso_type &&
2924 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2925 goto out_unlock;
2926
2927 err = -ENOBUFS;
2928 hlen = LL_RESERVED_SPACE(dev);
2929 tlen = dev->needed_tailroom;
2930 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2931 linear = max(linear, min_t(int, len, dev->hard_header_len));
2932 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2933 msg->msg_flags & MSG_DONTWAIT, &err);
2934 if (skb == NULL)
2935 goto out_unlock;
2936
2937 skb_reset_network_header(skb);
2938
2939 err = -EINVAL;
2940 if (sock->type == SOCK_DGRAM) {
2941 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2942 if (unlikely(offset < 0))
2943 goto out_free;
2944 } else if (reserve) {
2945 skb_reserve(skb, -reserve);
2946 if (len < reserve + sizeof(struct ipv6hdr) &&
2947 dev->min_header_len != dev->hard_header_len)
2948 skb_reset_network_header(skb);
2949 }
2950
2951 /* Returns -EFAULT on error */
2952 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2953 if (err)
2954 goto out_free;
2955
2956 if (sock->type == SOCK_RAW &&
2957 !dev_validate_header(dev, skb->data, len)) {
2958 err = -EINVAL;
2959 goto out_free;
2960 }
2961
2962 skb_setup_tx_timestamp(skb, sockc.tsflags);
2963
2964 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2965 !packet_extra_vlan_len_allowed(dev, skb)) {
2966 err = -EMSGSIZE;
2967 goto out_free;
2968 }
2969
2970 skb->protocol = proto;
2971 skb->dev = dev;
2972 skb->priority = sk->sk_priority;
2973 skb->mark = sockc.mark;
2974 skb->tstamp = sockc.transmit_time;
2975
2976 if (has_vnet_hdr) {
2977 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2978 if (err)
2979 goto out_free;
2980 len += sizeof(vnet_hdr);
2981 virtio_net_hdr_set_proto(skb, &vnet_hdr);
2982 }
2983
2984 packet_parse_headers(skb, sock);
2985
2986 if (unlikely(extra_len == 4))
2987 skb->no_fcs = 1;
2988
2989 err = po->xmit(skb);
2990 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2991 goto out_unlock;
2992
2993 dev_put(dev);
2994
2995 return len;
2996
2997out_free:
2998 kfree_skb(skb);
2999out_unlock:
3000 if (dev)
3001 dev_put(dev);
3002out:
3003 return err;
3004}
3005
3006static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3007{
3008 struct sock *sk = sock->sk;
3009 struct packet_sock *po = pkt_sk(sk);
3010
3011 if (po->tx_ring.pg_vec)
3012 return tpacket_snd(po, msg);
3013 else
3014 return packet_snd(sock, msg, len);
3015}
3016
3017/*
3018 * Close a PACKET socket. This is fairly simple. We immediately go
3019 * to 'closed' state and remove our protocol entry in the device list.
3020 */
3021
3022static int packet_release(struct socket *sock)
3023{
3024 struct sock *sk = sock->sk;
3025 struct packet_sock *po;
3026 struct packet_fanout *f;
3027 struct net *net;
3028 union tpacket_req_u req_u;
3029
3030 if (!sk)
3031 return 0;
3032
3033 net = sock_net(sk);
3034 po = pkt_sk(sk);
3035
3036 mutex_lock(&net->packet.sklist_lock);
3037 sk_del_node_init_rcu(sk);
3038 mutex_unlock(&net->packet.sklist_lock);
3039
3040 preempt_disable();
3041 sock_prot_inuse_add(net, sk->sk_prot, -1);
3042 preempt_enable();
3043
3044 spin_lock(&po->bind_lock);
3045 unregister_prot_hook(sk, false);
3046 packet_cached_dev_reset(po);
3047
3048 if (po->prot_hook.dev) {
3049 dev_put(po->prot_hook.dev);
3050 po->prot_hook.dev = NULL;
3051 }
3052 spin_unlock(&po->bind_lock);
3053
3054 packet_flush_mclist(sk);
3055
3056 lock_sock(sk);
3057 if (po->rx_ring.pg_vec) {
3058 memset(&req_u, 0, sizeof(req_u));
3059 packet_set_ring(sk, &req_u, 1, 0);
3060 }
3061
3062 if (po->tx_ring.pg_vec) {
3063 memset(&req_u, 0, sizeof(req_u));
3064 packet_set_ring(sk, &req_u, 1, 1);
3065 }
3066 release_sock(sk);
3067
3068 f = fanout_release(sk);
3069
3070 synchronize_net();
3071
3072 kfree(po->rollover);
3073 if (f) {
3074 fanout_release_data(f);
3075 kfree(f);
3076 }
3077 /*
3078 * Now the socket is dead. No more input will appear.
3079 */
3080 sock_orphan(sk);
3081 sock->sk = NULL;
3082
3083 /* Purge queues */
3084
3085 skb_queue_purge(&sk->sk_receive_queue);
3086 packet_free_pending(po);
3087 sk_refcnt_debug_release(sk);
3088
3089 sock_put(sk);
3090 return 0;
3091}
3092
3093/*
3094 * Attach a packet hook.
3095 */
3096
3097static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3098 __be16 proto)
3099{
3100 struct packet_sock *po = pkt_sk(sk);
3101 struct net_device *dev_curr;
3102 __be16 proto_curr;
3103 bool need_rehook;
3104 struct net_device *dev = NULL;
3105 int ret = 0;
3106 bool unlisted = false;
3107
3108 lock_sock(sk);
3109 spin_lock(&po->bind_lock);
3110 rcu_read_lock();
3111
3112 if (po->fanout) {
3113 ret = -EINVAL;
3114 goto out_unlock;
3115 }
3116
3117 if (name) {
3118 dev = dev_get_by_name_rcu(sock_net(sk), name);
3119 if (!dev) {
3120 ret = -ENODEV;
3121 goto out_unlock;
3122 }
3123 } else if (ifindex) {
3124 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3125 if (!dev) {
3126 ret = -ENODEV;
3127 goto out_unlock;
3128 }
3129 }
3130
3131 if (dev)
3132 dev_hold(dev);
3133
3134 proto_curr = po->prot_hook.type;
3135 dev_curr = po->prot_hook.dev;
3136
3137 need_rehook = proto_curr != proto || dev_curr != dev;
3138
3139 if (need_rehook) {
3140 if (po->running) {
3141 rcu_read_unlock();
3142 /* prevents packet_notifier() from calling
3143 * register_prot_hook()
3144 */
3145 po->num = 0;
3146 __unregister_prot_hook(sk, true);
3147 rcu_read_lock();
3148 dev_curr = po->prot_hook.dev;
3149 if (dev)
3150 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3151 dev->ifindex);
3152 }
3153
3154 BUG_ON(po->running);
3155 po->num = proto;
3156 po->prot_hook.type = proto;
3157
3158 if (unlikely(unlisted)) {
3159 dev_put(dev);
3160 po->prot_hook.dev = NULL;
3161 po->ifindex = -1;
3162 packet_cached_dev_reset(po);
3163 } else {
3164 po->prot_hook.dev = dev;
3165 po->ifindex = dev ? dev->ifindex : 0;
3166 packet_cached_dev_assign(po, dev);
3167 }
3168 }
3169 if (dev_curr)
3170 dev_put(dev_curr);
3171
3172 if (proto == 0 || !need_rehook)
3173 goto out_unlock;
3174
3175 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3176 register_prot_hook(sk);
3177 } else {
3178 sk->sk_err = ENETDOWN;
3179 if (!sock_flag(sk, SOCK_DEAD))
3180 sk->sk_error_report(sk);
3181 }
3182
3183out_unlock:
3184 rcu_read_unlock();
3185 spin_unlock(&po->bind_lock);
3186 release_sock(sk);
3187 return ret;
3188}
3189
3190/*
3191 * Bind a packet socket to a device
3192 */
3193
3194static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3195 int addr_len)
3196{
3197 struct sock *sk = sock->sk;
3198 char name[sizeof(uaddr->sa_data) + 1];
3199
3200 /*
3201 * Check legality
3202 */
3203
3204 if (addr_len != sizeof(struct sockaddr))
3205 return -EINVAL;
3206 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3207 * zero-terminated.
3208 */
3209 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3210 name[sizeof(uaddr->sa_data)] = 0;
3211
3212 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3213}
3214
3215static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3216{
3217 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3218 struct sock *sk = sock->sk;
3219
3220 /*
3221 * Check legality
3222 */
3223
3224 if (addr_len < sizeof(struct sockaddr_ll))
3225 return -EINVAL;
3226 if (sll->sll_family != AF_PACKET)
3227 return -EINVAL;
3228
3229 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3230 sll->sll_protocol ? : pkt_sk(sk)->num);
3231}
3232
3233static struct proto packet_proto = {
3234 .name = "PACKET",
3235 .owner = THIS_MODULE,
3236 .obj_size = sizeof(struct packet_sock),
3237};
3238
3239/*
3240 * Create a packet of type SOCK_PACKET.
3241 */
3242
3243static int packet_create(struct net *net, struct socket *sock, int protocol,
3244 int kern)
3245{
3246 struct sock *sk;
3247 struct packet_sock *po;
3248 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3249 int err;
3250
3251 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3252 return -EPERM;
3253 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3254 sock->type != SOCK_PACKET)
3255 return -ESOCKTNOSUPPORT;
3256
3257 sock->state = SS_UNCONNECTED;
3258
3259 err = -ENOBUFS;
3260 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3261 if (sk == NULL)
3262 goto out;
3263
3264 sock->ops = &packet_ops;
3265 if (sock->type == SOCK_PACKET)
3266 sock->ops = &packet_ops_spkt;
3267
3268 sock_init_data(sock, sk);
3269
3270 po = pkt_sk(sk);
3271 init_completion(&po->skb_completion);
3272 sk->sk_family = PF_PACKET;
3273 po->num = proto;
3274 po->xmit = dev_queue_xmit;
3275
3276 err = packet_alloc_pending(po);
3277 if (err)
3278 goto out2;
3279
3280 packet_cached_dev_reset(po);
3281
3282 sk->sk_destruct = packet_sock_destruct;
3283 sk_refcnt_debug_inc(sk);
3284
3285 /*
3286 * Attach a protocol block
3287 */
3288
3289 spin_lock_init(&po->bind_lock);
3290 mutex_init(&po->pg_vec_lock);
3291 po->rollover = NULL;
3292 po->prot_hook.func = packet_rcv;
3293
3294 if (sock->type == SOCK_PACKET)
3295 po->prot_hook.func = packet_rcv_spkt;
3296
3297 po->prot_hook.af_packet_priv = sk;
3298
3299 if (proto) {
3300 po->prot_hook.type = proto;
3301 __register_prot_hook(sk);
3302 }
3303
3304 mutex_lock(&net->packet.sklist_lock);
3305 sk_add_node_tail_rcu(sk, &net->packet.sklist);
3306 mutex_unlock(&net->packet.sklist_lock);
3307
3308 preempt_disable();
3309 sock_prot_inuse_add(net, &packet_proto, 1);
3310 preempt_enable();
3311
3312 return 0;
3313out2:
3314 sk_free(sk);
3315out:
3316 return err;
3317}
3318
3319/*
3320 * Pull a packet from our receive queue and hand it to the user.
3321 * If necessary we block.
3322 */
3323
3324static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3325 int flags)
3326{
3327 struct sock *sk = sock->sk;
3328 struct sk_buff *skb;
3329 int copied, err;
3330 int vnet_hdr_len = 0;
3331 unsigned int origlen = 0;
3332
3333 err = -EINVAL;
3334 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3335 goto out;
3336
3337#if 0
3338 /* What error should we return now? EUNATTACH? */
3339 if (pkt_sk(sk)->ifindex < 0)
3340 return -ENODEV;
3341#endif
3342
3343 if (flags & MSG_ERRQUEUE) {
3344 err = sock_recv_errqueue(sk, msg, len,
3345 SOL_PACKET, PACKET_TX_TIMESTAMP);
3346 goto out;
3347 }
3348
3349 /*
3350 * Call the generic datagram receiver. This handles all sorts
3351 * of horrible races and re-entrancy so we can forget about it
3352 * in the protocol layers.
3353 *
3354 * Now it will return ENETDOWN, if device have just gone down,
3355 * but then it will block.
3356 */
3357
3358 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3359
3360 /*
3361 * An error occurred so return it. Because skb_recv_datagram()
3362 * handles the blocking we don't see and worry about blocking
3363 * retries.
3364 */
3365
3366 if (skb == NULL)
3367 goto out;
3368
3369 packet_rcv_try_clear_pressure(pkt_sk(sk));
3370
3371 if (pkt_sk(sk)->has_vnet_hdr) {
3372 err = packet_rcv_vnet(msg, skb, &len);
3373 if (err)
3374 goto out_free;
3375 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3376 }
3377
3378 /* You lose any data beyond the buffer you gave. If it worries
3379 * a user program they can ask the device for its MTU
3380 * anyway.
3381 */
3382 copied = skb->len;
3383 if (copied > len) {
3384 copied = len;
3385 msg->msg_flags |= MSG_TRUNC;
3386 }
3387
3388 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3389 if (err)
3390 goto out_free;
3391
3392 if (sock->type != SOCK_PACKET) {
3393 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3394
3395 /* Original length was stored in sockaddr_ll fields */
3396 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3397 sll->sll_family = AF_PACKET;
3398 sll->sll_protocol = skb->protocol;
3399 }
3400
3401 sock_recv_ts_and_drops(msg, sk, skb);
3402
3403 if (msg->msg_name) {
3404 int copy_len;
3405
3406 /* If the address length field is there to be filled
3407 * in, we fill it in now.
3408 */
3409 if (sock->type == SOCK_PACKET) {
3410 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3411 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3412 copy_len = msg->msg_namelen;
3413 } else {
3414 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3415
3416 msg->msg_namelen = sll->sll_halen +
3417 offsetof(struct sockaddr_ll, sll_addr);
3418 copy_len = msg->msg_namelen;
3419 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3420 memset(msg->msg_name +
3421 offsetof(struct sockaddr_ll, sll_addr),
3422 0, sizeof(sll->sll_addr));
3423 msg->msg_namelen = sizeof(struct sockaddr_ll);
3424 }
3425 }
3426 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3427 }
3428
3429 if (pkt_sk(sk)->auxdata) {
3430 struct tpacket_auxdata aux;
3431
3432 aux.tp_status = TP_STATUS_USER;
3433 if (skb->ip_summed == CHECKSUM_PARTIAL)
3434 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3435 else if (skb->pkt_type != PACKET_OUTGOING &&
3436 (skb->ip_summed == CHECKSUM_COMPLETE ||
3437 skb_csum_unnecessary(skb)))
3438 aux.tp_status |= TP_STATUS_CSUM_VALID;
3439
3440 aux.tp_len = origlen;
3441 aux.tp_snaplen = skb->len;
3442 aux.tp_mac = 0;
3443 aux.tp_net = skb_network_offset(skb);
3444 if (skb_vlan_tag_present(skb)) {
3445 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3446 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3447 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3448 } else {
3449 aux.tp_vlan_tci = 0;
3450 aux.tp_vlan_tpid = 0;
3451 }
3452 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3453 }
3454
3455 /*
3456 * Free or return the buffer as appropriate. Again this
3457 * hides all the races and re-entrancy issues from us.
3458 */
3459 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3460
3461out_free:
3462 skb_free_datagram(sk, skb);
3463out:
3464 return err;
3465}
3466
3467static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3468 int peer)
3469{
3470 struct net_device *dev;
3471 struct sock *sk = sock->sk;
3472
3473 if (peer)
3474 return -EOPNOTSUPP;
3475
3476 uaddr->sa_family = AF_PACKET;
3477 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3478 rcu_read_lock();
3479 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3480 if (dev)
3481 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3482 rcu_read_unlock();
3483
3484 return sizeof(*uaddr);
3485}
3486
3487static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3488 int peer)
3489{
3490 struct net_device *dev;
3491 struct sock *sk = sock->sk;
3492 struct packet_sock *po = pkt_sk(sk);
3493 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3494
3495 if (peer)
3496 return -EOPNOTSUPP;
3497
3498 sll->sll_family = AF_PACKET;
3499 sll->sll_ifindex = po->ifindex;
3500 sll->sll_protocol = po->num;
3501 sll->sll_pkttype = 0;
3502 rcu_read_lock();
3503 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3504 if (dev) {
3505 sll->sll_hatype = dev->type;
3506 sll->sll_halen = dev->addr_len;
3507 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3508 } else {
3509 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3510 sll->sll_halen = 0;
3511 }
3512 rcu_read_unlock();
3513
3514 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3515}
3516
3517static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3518 int what)
3519{
3520 switch (i->type) {
3521 case PACKET_MR_MULTICAST:
3522 if (i->alen != dev->addr_len)
3523 return -EINVAL;
3524 if (what > 0)
3525 return dev_mc_add(dev, i->addr);
3526 else
3527 return dev_mc_del(dev, i->addr);
3528 break;
3529 case PACKET_MR_PROMISC:
3530 return dev_set_promiscuity(dev, what);
3531 case PACKET_MR_ALLMULTI:
3532 return dev_set_allmulti(dev, what);
3533 case PACKET_MR_UNICAST:
3534 if (i->alen != dev->addr_len)
3535 return -EINVAL;
3536 if (what > 0)
3537 return dev_uc_add(dev, i->addr);
3538 else
3539 return dev_uc_del(dev, i->addr);
3540 break;
3541 default:
3542 break;
3543 }
3544 return 0;
3545}
3546
3547static void packet_dev_mclist_delete(struct net_device *dev,
3548 struct packet_mclist **mlp)
3549{
3550 struct packet_mclist *ml;
3551
3552 while ((ml = *mlp) != NULL) {
3553 if (ml->ifindex == dev->ifindex) {
3554 packet_dev_mc(dev, ml, -1);
3555 *mlp = ml->next;
3556 kfree(ml);
3557 } else
3558 mlp = &ml->next;
3559 }
3560}
3561
3562static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3563{
3564 struct packet_sock *po = pkt_sk(sk);
3565 struct packet_mclist *ml, *i;
3566 struct net_device *dev;
3567 int err;
3568
3569 rtnl_lock();
3570
3571 err = -ENODEV;
3572 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3573 if (!dev)
3574 goto done;
3575
3576 err = -EINVAL;
3577 if (mreq->mr_alen > dev->addr_len)
3578 goto done;
3579
3580 err = -ENOBUFS;
3581 i = kmalloc(sizeof(*i), GFP_KERNEL);
3582 if (i == NULL)
3583 goto done;
3584
3585 err = 0;
3586 for (ml = po->mclist; ml; ml = ml->next) {
3587 if (ml->ifindex == mreq->mr_ifindex &&
3588 ml->type == mreq->mr_type &&
3589 ml->alen == mreq->mr_alen &&
3590 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3591 ml->count++;
3592 /* Free the new element ... */
3593 kfree(i);
3594 goto done;
3595 }
3596 }
3597
3598 i->type = mreq->mr_type;
3599 i->ifindex = mreq->mr_ifindex;
3600 i->alen = mreq->mr_alen;
3601 memcpy(i->addr, mreq->mr_address, i->alen);
3602 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3603 i->count = 1;
3604 i->next = po->mclist;
3605 po->mclist = i;
3606 err = packet_dev_mc(dev, i, 1);
3607 if (err) {
3608 po->mclist = i->next;
3609 kfree(i);
3610 }
3611
3612done:
3613 rtnl_unlock();
3614 return err;
3615}
3616
3617static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3618{
3619 struct packet_mclist *ml, **mlp;
3620
3621 rtnl_lock();
3622
3623 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3624 if (ml->ifindex == mreq->mr_ifindex &&
3625 ml->type == mreq->mr_type &&
3626 ml->alen == mreq->mr_alen &&
3627 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3628 if (--ml->count == 0) {
3629 struct net_device *dev;
3630 *mlp = ml->next;
3631 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3632 if (dev)
3633 packet_dev_mc(dev, ml, -1);
3634 kfree(ml);
3635 }
3636 break;
3637 }
3638 }
3639 rtnl_unlock();
3640 return 0;
3641}
3642
3643static void packet_flush_mclist(struct sock *sk)
3644{
3645 struct packet_sock *po = pkt_sk(sk);
3646 struct packet_mclist *ml;
3647
3648 if (!po->mclist)
3649 return;
3650
3651 rtnl_lock();
3652 while ((ml = po->mclist) != NULL) {
3653 struct net_device *dev;
3654
3655 po->mclist = ml->next;
3656 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3657 if (dev != NULL)
3658 packet_dev_mc(dev, ml, -1);
3659 kfree(ml);
3660 }
3661 rtnl_unlock();
3662}
3663
3664static int
3665packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3666 unsigned int optlen)
3667{
3668 struct sock *sk = sock->sk;
3669 struct packet_sock *po = pkt_sk(sk);
3670 int ret;
3671
3672 if (level != SOL_PACKET)
3673 return -ENOPROTOOPT;
3674
3675 switch (optname) {
3676 case PACKET_ADD_MEMBERSHIP:
3677 case PACKET_DROP_MEMBERSHIP:
3678 {
3679 struct packet_mreq_max mreq;
3680 int len = optlen;
3681 memset(&mreq, 0, sizeof(mreq));
3682 if (len < sizeof(struct packet_mreq))
3683 return -EINVAL;
3684 if (len > sizeof(mreq))
3685 len = sizeof(mreq);
3686 if (copy_from_sockptr(&mreq, optval, len))
3687 return -EFAULT;
3688 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3689 return -EINVAL;
3690 if (optname == PACKET_ADD_MEMBERSHIP)
3691 ret = packet_mc_add(sk, &mreq);
3692 else
3693 ret = packet_mc_drop(sk, &mreq);
3694 return ret;
3695 }
3696
3697 case PACKET_RX_RING:
3698 case PACKET_TX_RING:
3699 {
3700 union tpacket_req_u req_u;
3701 int len;
3702
3703 lock_sock(sk);
3704 switch (po->tp_version) {
3705 case TPACKET_V1:
3706 case TPACKET_V2:
3707 len = sizeof(req_u.req);
3708 break;
3709 case TPACKET_V3:
3710 default:
3711 len = sizeof(req_u.req3);
3712 break;
3713 }
3714 if (optlen < len) {
3715 ret = -EINVAL;
3716 } else {
3717 if (copy_from_sockptr(&req_u.req, optval, len))
3718 ret = -EFAULT;
3719 else
3720 ret = packet_set_ring(sk, &req_u, 0,
3721 optname == PACKET_TX_RING);
3722 }
3723 release_sock(sk);
3724 return ret;
3725 }
3726 case PACKET_COPY_THRESH:
3727 {
3728 int val;
3729
3730 if (optlen != sizeof(val))
3731 return -EINVAL;
3732 if (copy_from_sockptr(&val, optval, sizeof(val)))
3733 return -EFAULT;
3734
3735 pkt_sk(sk)->copy_thresh = val;
3736 return 0;
3737 }
3738 case PACKET_VERSION:
3739 {
3740 int val;
3741
3742 if (optlen != sizeof(val))
3743 return -EINVAL;
3744 if (copy_from_sockptr(&val, optval, sizeof(val)))
3745 return -EFAULT;
3746 switch (val) {
3747 case TPACKET_V1:
3748 case TPACKET_V2:
3749 case TPACKET_V3:
3750 break;
3751 default:
3752 return -EINVAL;
3753 }
3754 lock_sock(sk);
3755 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3756 ret = -EBUSY;
3757 } else {
3758 po->tp_version = val;
3759 ret = 0;
3760 }
3761 release_sock(sk);
3762 return ret;
3763 }
3764 case PACKET_RESERVE:
3765 {
3766 unsigned int val;
3767
3768 if (optlen != sizeof(val))
3769 return -EINVAL;
3770 if (copy_from_sockptr(&val, optval, sizeof(val)))
3771 return -EFAULT;
3772 if (val > INT_MAX)
3773 return -EINVAL;
3774 lock_sock(sk);
3775 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3776 ret = -EBUSY;
3777 } else {
3778 po->tp_reserve = val;
3779 ret = 0;
3780 }
3781 release_sock(sk);
3782 return ret;
3783 }
3784 case PACKET_LOSS:
3785 {
3786 unsigned int val;
3787
3788 if (optlen != sizeof(val))
3789 return -EINVAL;
3790 if (copy_from_sockptr(&val, optval, sizeof(val)))
3791 return -EFAULT;
3792
3793 lock_sock(sk);
3794 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3795 ret = -EBUSY;
3796 } else {
3797 po->tp_loss = !!val;
3798 ret = 0;
3799 }
3800 release_sock(sk);
3801 return ret;
3802 }
3803 case PACKET_AUXDATA:
3804 {
3805 int val;
3806
3807 if (optlen < sizeof(val))
3808 return -EINVAL;
3809 if (copy_from_sockptr(&val, optval, sizeof(val)))
3810 return -EFAULT;
3811
3812 lock_sock(sk);
3813 po->auxdata = !!val;
3814 release_sock(sk);
3815 return 0;
3816 }
3817 case PACKET_ORIGDEV:
3818 {
3819 int val;
3820
3821 if (optlen < sizeof(val))
3822 return -EINVAL;
3823 if (copy_from_sockptr(&val, optval, sizeof(val)))
3824 return -EFAULT;
3825
3826 lock_sock(sk);
3827 po->origdev = !!val;
3828 release_sock(sk);
3829 return 0;
3830 }
3831 case PACKET_VNET_HDR:
3832 {
3833 int val;
3834
3835 if (sock->type != SOCK_RAW)
3836 return -EINVAL;
3837 if (optlen < sizeof(val))
3838 return -EINVAL;
3839 if (copy_from_sockptr(&val, optval, sizeof(val)))
3840 return -EFAULT;
3841
3842 lock_sock(sk);
3843 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3844 ret = -EBUSY;
3845 } else {
3846 po->has_vnet_hdr = !!val;
3847 ret = 0;
3848 }
3849 release_sock(sk);
3850 return ret;
3851 }
3852 case PACKET_TIMESTAMP:
3853 {
3854 int val;
3855
3856 if (optlen != sizeof(val))
3857 return -EINVAL;
3858 if (copy_from_sockptr(&val, optval, sizeof(val)))
3859 return -EFAULT;
3860
3861 po->tp_tstamp = val;
3862 return 0;
3863 }
3864 case PACKET_FANOUT:
3865 {
3866 int val;
3867
3868 if (optlen != sizeof(val))
3869 return -EINVAL;
3870 if (copy_from_sockptr(&val, optval, sizeof(val)))
3871 return -EFAULT;
3872
3873 return fanout_add(sk, val & 0xffff, val >> 16);
3874 }
3875 case PACKET_FANOUT_DATA:
3876 {
3877 if (!po->fanout)
3878 return -EINVAL;
3879
3880 return fanout_set_data(po, optval, optlen);
3881 }
3882 case PACKET_IGNORE_OUTGOING:
3883 {
3884 int val;
3885
3886 if (optlen != sizeof(val))
3887 return -EINVAL;
3888 if (copy_from_sockptr(&val, optval, sizeof(val)))
3889 return -EFAULT;
3890 if (val < 0 || val > 1)
3891 return -EINVAL;
3892
3893 po->prot_hook.ignore_outgoing = !!val;
3894 return 0;
3895 }
3896 case PACKET_TX_HAS_OFF:
3897 {
3898 unsigned int val;
3899
3900 if (optlen != sizeof(val))
3901 return -EINVAL;
3902 if (copy_from_sockptr(&val, optval, sizeof(val)))
3903 return -EFAULT;
3904
3905 lock_sock(sk);
3906 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3907 ret = -EBUSY;
3908 } else {
3909 po->tp_tx_has_off = !!val;
3910 ret = 0;
3911 }
3912 release_sock(sk);
3913 return 0;
3914 }
3915 case PACKET_QDISC_BYPASS:
3916 {
3917 int val;
3918
3919 if (optlen != sizeof(val))
3920 return -EINVAL;
3921 if (copy_from_sockptr(&val, optval, sizeof(val)))
3922 return -EFAULT;
3923
3924 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3925 return 0;
3926 }
3927 default:
3928 return -ENOPROTOOPT;
3929 }
3930}
3931
3932static int packet_getsockopt(struct socket *sock, int level, int optname,
3933 char __user *optval, int __user *optlen)
3934{
3935 int len;
3936 int val, lv = sizeof(val);
3937 struct sock *sk = sock->sk;
3938 struct packet_sock *po = pkt_sk(sk);
3939 void *data = &val;
3940 union tpacket_stats_u st;
3941 struct tpacket_rollover_stats rstats;
3942 int drops;
3943
3944 if (level != SOL_PACKET)
3945 return -ENOPROTOOPT;
3946
3947 if (get_user(len, optlen))
3948 return -EFAULT;
3949
3950 if (len < 0)
3951 return -EINVAL;
3952
3953 switch (optname) {
3954 case PACKET_STATISTICS:
3955 spin_lock_bh(&sk->sk_receive_queue.lock);
3956 memcpy(&st, &po->stats, sizeof(st));
3957 memset(&po->stats, 0, sizeof(po->stats));
3958 spin_unlock_bh(&sk->sk_receive_queue.lock);
3959 drops = atomic_xchg(&po->tp_drops, 0);
3960
3961 if (po->tp_version == TPACKET_V3) {
3962 lv = sizeof(struct tpacket_stats_v3);
3963 st.stats3.tp_drops = drops;
3964 st.stats3.tp_packets += drops;
3965 data = &st.stats3;
3966 } else {
3967 lv = sizeof(struct tpacket_stats);
3968 st.stats1.tp_drops = drops;
3969 st.stats1.tp_packets += drops;
3970 data = &st.stats1;
3971 }
3972
3973 break;
3974 case PACKET_AUXDATA:
3975 val = po->auxdata;
3976 break;
3977 case PACKET_ORIGDEV:
3978 val = po->origdev;
3979 break;
3980 case PACKET_VNET_HDR:
3981 val = po->has_vnet_hdr;
3982 break;
3983 case PACKET_VERSION:
3984 val = po->tp_version;
3985 break;
3986 case PACKET_HDRLEN:
3987 if (len > sizeof(int))
3988 len = sizeof(int);
3989 if (len < sizeof(int))
3990 return -EINVAL;
3991 if (copy_from_user(&val, optval, len))
3992 return -EFAULT;
3993 switch (val) {
3994 case TPACKET_V1:
3995 val = sizeof(struct tpacket_hdr);
3996 break;
3997 case TPACKET_V2:
3998 val = sizeof(struct tpacket2_hdr);
3999 break;
4000 case TPACKET_V3:
4001 val = sizeof(struct tpacket3_hdr);
4002 break;
4003 default:
4004 return -EINVAL;
4005 }
4006 break;
4007 case PACKET_RESERVE:
4008 val = po->tp_reserve;
4009 break;
4010 case PACKET_LOSS:
4011 val = po->tp_loss;
4012 break;
4013 case PACKET_TIMESTAMP:
4014 val = po->tp_tstamp;
4015 break;
4016 case PACKET_FANOUT:
4017 val = (po->fanout ?
4018 ((u32)po->fanout->id |
4019 ((u32)po->fanout->type << 16) |
4020 ((u32)po->fanout->flags << 24)) :
4021 0);
4022 break;
4023 case PACKET_IGNORE_OUTGOING:
4024 val = po->prot_hook.ignore_outgoing;
4025 break;
4026 case PACKET_ROLLOVER_STATS:
4027 if (!po->rollover)
4028 return -EINVAL;
4029 rstats.tp_all = atomic_long_read(&po->rollover->num);
4030 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4031 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4032 data = &rstats;
4033 lv = sizeof(rstats);
4034 break;
4035 case PACKET_TX_HAS_OFF:
4036 val = po->tp_tx_has_off;
4037 break;
4038 case PACKET_QDISC_BYPASS:
4039 val = packet_use_direct_xmit(po);
4040 break;
4041 default:
4042 return -ENOPROTOOPT;
4043 }
4044
4045 if (len > lv)
4046 len = lv;
4047 if (put_user(len, optlen))
4048 return -EFAULT;
4049 if (copy_to_user(optval, data, len))
4050 return -EFAULT;
4051 return 0;
4052}
4053
4054static int packet_notifier(struct notifier_block *this,
4055 unsigned long msg, void *ptr)
4056{
4057 struct sock *sk;
4058 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4059 struct net *net = dev_net(dev);
4060
4061 rcu_read_lock();
4062 sk_for_each_rcu(sk, &net->packet.sklist) {
4063 struct packet_sock *po = pkt_sk(sk);
4064
4065 switch (msg) {
4066 case NETDEV_UNREGISTER:
4067 if (po->mclist)
4068 packet_dev_mclist_delete(dev, &po->mclist);
4069 fallthrough;
4070
4071 case NETDEV_DOWN:
4072 if (dev->ifindex == po->ifindex) {
4073 spin_lock(&po->bind_lock);
4074 if (po->running) {
4075 __unregister_prot_hook(sk, false);
4076 sk->sk_err = ENETDOWN;
4077 if (!sock_flag(sk, SOCK_DEAD))
4078 sk->sk_error_report(sk);
4079 }
4080 if (msg == NETDEV_UNREGISTER) {
4081 packet_cached_dev_reset(po);
4082 po->ifindex = -1;
4083 if (po->prot_hook.dev)
4084 dev_put(po->prot_hook.dev);
4085 po->prot_hook.dev = NULL;
4086 }
4087 spin_unlock(&po->bind_lock);
4088 }
4089 break;
4090 case NETDEV_UP:
4091 if (dev->ifindex == po->ifindex) {
4092 spin_lock(&po->bind_lock);
4093 if (po->num)
4094 register_prot_hook(sk);
4095 spin_unlock(&po->bind_lock);
4096 }
4097 break;
4098 }
4099 }
4100 rcu_read_unlock();
4101 return NOTIFY_DONE;
4102}
4103
4104
4105static int packet_ioctl(struct socket *sock, unsigned int cmd,
4106 unsigned long arg)
4107{
4108 struct sock *sk = sock->sk;
4109
4110 switch (cmd) {
4111 case SIOCOUTQ:
4112 {
4113 int amount = sk_wmem_alloc_get(sk);
4114
4115 return put_user(amount, (int __user *)arg);
4116 }
4117 case SIOCINQ:
4118 {
4119 struct sk_buff *skb;
4120 int amount = 0;
4121
4122 spin_lock_bh(&sk->sk_receive_queue.lock);
4123 skb = skb_peek(&sk->sk_receive_queue);
4124 if (skb)
4125 amount = skb->len;
4126 spin_unlock_bh(&sk->sk_receive_queue.lock);
4127 return put_user(amount, (int __user *)arg);
4128 }
4129#ifdef CONFIG_INET
4130 case SIOCADDRT:
4131 case SIOCDELRT:
4132 case SIOCDARP:
4133 case SIOCGARP:
4134 case SIOCSARP:
4135 case SIOCGIFADDR:
4136 case SIOCSIFADDR:
4137 case SIOCGIFBRDADDR:
4138 case SIOCSIFBRDADDR:
4139 case SIOCGIFNETMASK:
4140 case SIOCSIFNETMASK:
4141 case SIOCGIFDSTADDR:
4142 case SIOCSIFDSTADDR:
4143 case SIOCSIFFLAGS:
4144 return inet_dgram_ops.ioctl(sock, cmd, arg);
4145#endif
4146
4147 default:
4148 return -ENOIOCTLCMD;
4149 }
4150 return 0;
4151}
4152
4153static __poll_t packet_poll(struct file *file, struct socket *sock,
4154 poll_table *wait)
4155{
4156 struct sock *sk = sock->sk;
4157 struct packet_sock *po = pkt_sk(sk);
4158 __poll_t mask = datagram_poll(file, sock, wait);
4159
4160 spin_lock_bh(&sk->sk_receive_queue.lock);
4161 if (po->rx_ring.pg_vec) {
4162 if (!packet_previous_rx_frame(po, &po->rx_ring,
4163 TP_STATUS_KERNEL))
4164 mask |= EPOLLIN | EPOLLRDNORM;
4165 }
4166 packet_rcv_try_clear_pressure(po);
4167 spin_unlock_bh(&sk->sk_receive_queue.lock);
4168 spin_lock_bh(&sk->sk_write_queue.lock);
4169 if (po->tx_ring.pg_vec) {
4170 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4171 mask |= EPOLLOUT | EPOLLWRNORM;
4172 }
4173 spin_unlock_bh(&sk->sk_write_queue.lock);
4174 return mask;
4175}
4176
4177
4178/* Dirty? Well, I still did not learn better way to account
4179 * for user mmaps.
4180 */
4181
4182static void packet_mm_open(struct vm_area_struct *vma)
4183{
4184 struct file *file = vma->vm_file;
4185 struct socket *sock = file->private_data;
4186 struct sock *sk = sock->sk;
4187
4188 if (sk)
4189 atomic_inc(&pkt_sk(sk)->mapped);
4190}
4191
4192static void packet_mm_close(struct vm_area_struct *vma)
4193{
4194 struct file *file = vma->vm_file;
4195 struct socket *sock = file->private_data;
4196 struct sock *sk = sock->sk;
4197
4198 if (sk)
4199 atomic_dec(&pkt_sk(sk)->mapped);
4200}
4201
4202static const struct vm_operations_struct packet_mmap_ops = {
4203 .open = packet_mm_open,
4204 .close = packet_mm_close,
4205};
4206
4207static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4208 unsigned int len)
4209{
4210 int i;
4211
4212 for (i = 0; i < len; i++) {
4213 if (likely(pg_vec[i].buffer)) {
4214 if (is_vmalloc_addr(pg_vec[i].buffer))
4215 vfree(pg_vec[i].buffer);
4216 else
4217 free_pages((unsigned long)pg_vec[i].buffer,
4218 order);
4219 pg_vec[i].buffer = NULL;
4220 }
4221 }
4222 kfree(pg_vec);
4223}
4224
4225static char *alloc_one_pg_vec_page(unsigned long order)
4226{
4227 char *buffer;
4228 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4229 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4230
4231 buffer = (char *) __get_free_pages(gfp_flags, order);
4232 if (buffer)
4233 return buffer;
4234
4235 /* __get_free_pages failed, fall back to vmalloc */
4236 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4237 if (buffer)
4238 return buffer;
4239
4240 /* vmalloc failed, lets dig into swap here */
4241 gfp_flags &= ~__GFP_NORETRY;
4242 buffer = (char *) __get_free_pages(gfp_flags, order);
4243 if (buffer)
4244 return buffer;
4245
4246 /* complete and utter failure */
4247 return NULL;
4248}
4249
4250static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4251{
4252 unsigned int block_nr = req->tp_block_nr;
4253 struct pgv *pg_vec;
4254 int i;
4255
4256 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4257 if (unlikely(!pg_vec))
4258 goto out;
4259
4260 for (i = 0; i < block_nr; i++) {
4261 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4262 if (unlikely(!pg_vec[i].buffer))
4263 goto out_free_pgvec;
4264 }
4265
4266out:
4267 return pg_vec;
4268
4269out_free_pgvec:
4270 free_pg_vec(pg_vec, order, block_nr);
4271 pg_vec = NULL;
4272 goto out;
4273}
4274
4275static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4276 int closing, int tx_ring)
4277{
4278 struct pgv *pg_vec = NULL;
4279 struct packet_sock *po = pkt_sk(sk);
4280 unsigned long *rx_owner_map = NULL;
4281 int was_running, order = 0;
4282 struct packet_ring_buffer *rb;
4283 struct sk_buff_head *rb_queue;
4284 __be16 num;
4285 int err;
4286 /* Added to avoid minimal code churn */
4287 struct tpacket_req *req = &req_u->req;
4288
4289 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4290 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4291
4292 err = -EBUSY;
4293 if (!closing) {
4294 if (atomic_read(&po->mapped))
4295 goto out;
4296 if (packet_read_pending(rb))
4297 goto out;
4298 }
4299
4300 if (req->tp_block_nr) {
4301 unsigned int min_frame_size;
4302
4303 /* Sanity tests and some calculations */
4304 err = -EBUSY;
4305 if (unlikely(rb->pg_vec))
4306 goto out;
4307
4308 switch (po->tp_version) {
4309 case TPACKET_V1:
4310 po->tp_hdrlen = TPACKET_HDRLEN;
4311 break;
4312 case TPACKET_V2:
4313 po->tp_hdrlen = TPACKET2_HDRLEN;
4314 break;
4315 case TPACKET_V3:
4316 po->tp_hdrlen = TPACKET3_HDRLEN;
4317 break;
4318 }
4319
4320 err = -EINVAL;
4321 if (unlikely((int)req->tp_block_size <= 0))
4322 goto out;
4323 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4324 goto out;
4325 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4326 if (po->tp_version >= TPACKET_V3 &&
4327 req->tp_block_size <
4328 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4329 goto out;
4330 if (unlikely(req->tp_frame_size < min_frame_size))
4331 goto out;
4332 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4333 goto out;
4334
4335 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4336 if (unlikely(rb->frames_per_block == 0))
4337 goto out;
4338 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4339 goto out;
4340 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4341 req->tp_frame_nr))
4342 goto out;
4343
4344 err = -ENOMEM;
4345 order = get_order(req->tp_block_size);
4346 pg_vec = alloc_pg_vec(req, order);
4347 if (unlikely(!pg_vec))
4348 goto out;
4349 switch (po->tp_version) {
4350 case TPACKET_V3:
4351 /* Block transmit is not supported yet */
4352 if (!tx_ring) {
4353 init_prb_bdqc(po, rb, pg_vec, req_u);
4354 } else {
4355 struct tpacket_req3 *req3 = &req_u->req3;
4356
4357 if (req3->tp_retire_blk_tov ||
4358 req3->tp_sizeof_priv ||
4359 req3->tp_feature_req_word) {
4360 err = -EINVAL;
4361 goto out_free_pg_vec;
4362 }
4363 }
4364 break;
4365 default:
4366 if (!tx_ring) {
4367 rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4368 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4369 if (!rx_owner_map)
4370 goto out_free_pg_vec;
4371 }
4372 break;
4373 }
4374 }
4375 /* Done */
4376 else {
4377 err = -EINVAL;
4378 if (unlikely(req->tp_frame_nr))
4379 goto out;
4380 }
4381
4382
4383 /* Detach socket from network */
4384 spin_lock(&po->bind_lock);
4385 was_running = po->running;
4386 num = po->num;
4387 if (was_running) {
4388 po->num = 0;
4389 __unregister_prot_hook(sk, false);
4390 }
4391 spin_unlock(&po->bind_lock);
4392
4393 synchronize_net();
4394
4395 err = -EBUSY;
4396 mutex_lock(&po->pg_vec_lock);
4397 if (closing || atomic_read(&po->mapped) == 0) {
4398 err = 0;
4399 spin_lock_bh(&rb_queue->lock);
4400 swap(rb->pg_vec, pg_vec);
4401 if (po->tp_version <= TPACKET_V2)
4402 swap(rb->rx_owner_map, rx_owner_map);
4403 rb->frame_max = (req->tp_frame_nr - 1);
4404 rb->head = 0;
4405 rb->frame_size = req->tp_frame_size;
4406 spin_unlock_bh(&rb_queue->lock);
4407
4408 swap(rb->pg_vec_order, order);
4409 swap(rb->pg_vec_len, req->tp_block_nr);
4410
4411 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4412 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4413 tpacket_rcv : packet_rcv;
4414 skb_queue_purge(rb_queue);
4415 if (atomic_read(&po->mapped))
4416 pr_err("packet_mmap: vma is busy: %d\n",
4417 atomic_read(&po->mapped));
4418 }
4419 mutex_unlock(&po->pg_vec_lock);
4420
4421 spin_lock(&po->bind_lock);
4422 if (was_running) {
4423 po->num = num;
4424 register_prot_hook(sk);
4425 }
4426 spin_unlock(&po->bind_lock);
4427 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4428 /* Because we don't support block-based V3 on tx-ring */
4429 if (!tx_ring)
4430 prb_shutdown_retire_blk_timer(po, rb_queue);
4431 }
4432
4433out_free_pg_vec:
4434 bitmap_free(rx_owner_map);
4435 if (pg_vec)
4436 free_pg_vec(pg_vec, order, req->tp_block_nr);
4437out:
4438 return err;
4439}
4440
4441static int packet_mmap(struct file *file, struct socket *sock,
4442 struct vm_area_struct *vma)
4443{
4444 struct sock *sk = sock->sk;
4445 struct packet_sock *po = pkt_sk(sk);
4446 unsigned long size, expected_size;
4447 struct packet_ring_buffer *rb;
4448 unsigned long start;
4449 int err = -EINVAL;
4450 int i;
4451
4452 if (vma->vm_pgoff)
4453 return -EINVAL;
4454
4455 mutex_lock(&po->pg_vec_lock);
4456
4457 expected_size = 0;
4458 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4459 if (rb->pg_vec) {
4460 expected_size += rb->pg_vec_len
4461 * rb->pg_vec_pages
4462 * PAGE_SIZE;
4463 }
4464 }
4465
4466 if (expected_size == 0)
4467 goto out;
4468
4469 size = vma->vm_end - vma->vm_start;
4470 if (size != expected_size)
4471 goto out;
4472
4473 start = vma->vm_start;
4474 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4475 if (rb->pg_vec == NULL)
4476 continue;
4477
4478 for (i = 0; i < rb->pg_vec_len; i++) {
4479 struct page *page;
4480 void *kaddr = rb->pg_vec[i].buffer;
4481 int pg_num;
4482
4483 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4484 page = pgv_to_page(kaddr);
4485 err = vm_insert_page(vma, start, page);
4486 if (unlikely(err))
4487 goto out;
4488 start += PAGE_SIZE;
4489 kaddr += PAGE_SIZE;
4490 }
4491 }
4492 }
4493
4494 atomic_inc(&po->mapped);
4495 vma->vm_ops = &packet_mmap_ops;
4496 err = 0;
4497
4498out:
4499 mutex_unlock(&po->pg_vec_lock);
4500 return err;
4501}
4502
4503static const struct proto_ops packet_ops_spkt = {
4504 .family = PF_PACKET,
4505 .owner = THIS_MODULE,
4506 .release = packet_release,
4507 .bind = packet_bind_spkt,
4508 .connect = sock_no_connect,
4509 .socketpair = sock_no_socketpair,
4510 .accept = sock_no_accept,
4511 .getname = packet_getname_spkt,
4512 .poll = datagram_poll,
4513 .ioctl = packet_ioctl,
4514 .gettstamp = sock_gettstamp,
4515 .listen = sock_no_listen,
4516 .shutdown = sock_no_shutdown,
4517 .sendmsg = packet_sendmsg_spkt,
4518 .recvmsg = packet_recvmsg,
4519 .mmap = sock_no_mmap,
4520 .sendpage = sock_no_sendpage,
4521};
4522
4523static const struct proto_ops packet_ops = {
4524 .family = PF_PACKET,
4525 .owner = THIS_MODULE,
4526 .release = packet_release,
4527 .bind = packet_bind,
4528 .connect = sock_no_connect,
4529 .socketpair = sock_no_socketpair,
4530 .accept = sock_no_accept,
4531 .getname = packet_getname,
4532 .poll = packet_poll,
4533 .ioctl = packet_ioctl,
4534 .gettstamp = sock_gettstamp,
4535 .listen = sock_no_listen,
4536 .shutdown = sock_no_shutdown,
4537 .setsockopt = packet_setsockopt,
4538 .getsockopt = packet_getsockopt,
4539 .sendmsg = packet_sendmsg,
4540 .recvmsg = packet_recvmsg,
4541 .mmap = packet_mmap,
4542 .sendpage = sock_no_sendpage,
4543};
4544
4545static const struct net_proto_family packet_family_ops = {
4546 .family = PF_PACKET,
4547 .create = packet_create,
4548 .owner = THIS_MODULE,
4549};
4550
4551static struct notifier_block packet_netdev_notifier = {
4552 .notifier_call = packet_notifier,
4553};
4554
4555#ifdef CONFIG_PROC_FS
4556
4557static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4558 __acquires(RCU)
4559{
4560 struct net *net = seq_file_net(seq);
4561
4562 rcu_read_lock();
4563 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4564}
4565
4566static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4567{
4568 struct net *net = seq_file_net(seq);
4569 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4570}
4571
4572static void packet_seq_stop(struct seq_file *seq, void *v)
4573 __releases(RCU)
4574{
4575 rcu_read_unlock();
4576}
4577
4578static int packet_seq_show(struct seq_file *seq, void *v)
4579{
4580 if (v == SEQ_START_TOKEN)
4581 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4582 else {
4583 struct sock *s = sk_entry(v);
4584 const struct packet_sock *po = pkt_sk(s);
4585
4586 seq_printf(seq,
4587 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4588 s,
4589 refcount_read(&s->sk_refcnt),
4590 s->sk_type,
4591 ntohs(po->num),
4592 po->ifindex,
4593 po->running,
4594 atomic_read(&s->sk_rmem_alloc),
4595 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4596 sock_i_ino(s));
4597 }
4598
4599 return 0;
4600}
4601
4602static const struct seq_operations packet_seq_ops = {
4603 .start = packet_seq_start,
4604 .next = packet_seq_next,
4605 .stop = packet_seq_stop,
4606 .show = packet_seq_show,
4607};
4608#endif
4609
4610static int __net_init packet_net_init(struct net *net)
4611{
4612 mutex_init(&net->packet.sklist_lock);
4613 INIT_HLIST_HEAD(&net->packet.sklist);
4614
4615 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4616 sizeof(struct seq_net_private)))
4617 return -ENOMEM;
4618
4619 return 0;
4620}
4621
4622static void __net_exit packet_net_exit(struct net *net)
4623{
4624 remove_proc_entry("packet", net->proc_net);
4625 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4626}
4627
4628static struct pernet_operations packet_net_ops = {
4629 .init = packet_net_init,
4630 .exit = packet_net_exit,
4631};
4632
4633
4634static void __exit packet_exit(void)
4635{
4636 unregister_netdevice_notifier(&packet_netdev_notifier);
4637 unregister_pernet_subsys(&packet_net_ops);
4638 sock_unregister(PF_PACKET);
4639 proto_unregister(&packet_proto);
4640}
4641
4642static int __init packet_init(void)
4643{
4644 int rc;
4645
4646 rc = proto_register(&packet_proto, 0);
4647 if (rc)
4648 goto out;
4649 rc = sock_register(&packet_family_ops);
4650 if (rc)
4651 goto out_proto;
4652 rc = register_pernet_subsys(&packet_net_ops);
4653 if (rc)
4654 goto out_sock;
4655 rc = register_netdevice_notifier(&packet_netdev_notifier);
4656 if (rc)
4657 goto out_pernet;
4658
4659 return 0;
4660
4661out_pernet:
4662 unregister_pernet_subsys(&packet_net_ops);
4663out_sock:
4664 sock_unregister(PF_PACKET);
4665out_proto:
4666 proto_unregister(&packet_proto);
4667out:
4668 return rc;
4669}
4670
4671module_init(packet_init);
4672module_exit(packet_exit);
4673MODULE_LICENSE("GPL");
4674MODULE_ALIAS_NETPROTO(PF_PACKET);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * PACKET - implements raw packet sockets.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 *
13 * Fixes:
14 * Alan Cox : verify_area() now used correctly
15 * Alan Cox : new skbuff lists, look ma no backlogs!
16 * Alan Cox : tidied skbuff lists.
17 * Alan Cox : Now uses generic datagram routines I
18 * added. Also fixed the peek/read crash
19 * from all old Linux datagram code.
20 * Alan Cox : Uses the improved datagram code.
21 * Alan Cox : Added NULL's for socket options.
22 * Alan Cox : Re-commented the code.
23 * Alan Cox : Use new kernel side addressing
24 * Rob Janssen : Correct MTU usage.
25 * Dave Platt : Counter leaks caused by incorrect
26 * interrupt locking and some slightly
27 * dubious gcc output. Can you read
28 * compiler: it said _VOLATILE_
29 * Richard Kooijman : Timestamp fixes.
30 * Alan Cox : New buffers. Use sk->mac.raw.
31 * Alan Cox : sendmsg/recvmsg support.
32 * Alan Cox : Protocol setting support
33 * Alexey Kuznetsov : Untied from IPv4 stack.
34 * Cyrus Durgin : Fixed kerneld for kmod.
35 * Michal Ostrowski : Module initialization cleanup.
36 * Ulises Alonso : Frame number limit removal and
37 * packet_set_ring memory leak.
38 * Eric Biederman : Allow for > 8 byte hardware addresses.
39 * The convention is that longer addresses
40 * will simply extend the hardware address
41 * byte arrays at the end of sockaddr_ll
42 * and packet_mreq.
43 * Johann Baudy : Added TX RING.
44 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * layer.
46 * Copyright (C) 2011, <lokec@ccs.neu.edu>
47 */
48
49#include <linux/types.h>
50#include <linux/mm.h>
51#include <linux/capability.h>
52#include <linux/fcntl.h>
53#include <linux/socket.h>
54#include <linux/in.h>
55#include <linux/inet.h>
56#include <linux/netdevice.h>
57#include <linux/if_packet.h>
58#include <linux/wireless.h>
59#include <linux/kernel.h>
60#include <linux/kmod.h>
61#include <linux/slab.h>
62#include <linux/vmalloc.h>
63#include <net/net_namespace.h>
64#include <net/ip.h>
65#include <net/protocol.h>
66#include <linux/skbuff.h>
67#include <net/sock.h>
68#include <linux/errno.h>
69#include <linux/timer.h>
70#include <linux/uaccess.h>
71#include <asm/ioctls.h>
72#include <asm/page.h>
73#include <asm/cacheflush.h>
74#include <asm/io.h>
75#include <linux/proc_fs.h>
76#include <linux/seq_file.h>
77#include <linux/poll.h>
78#include <linux/module.h>
79#include <linux/init.h>
80#include <linux/mutex.h>
81#include <linux/if_vlan.h>
82#include <linux/virtio_net.h>
83#include <linux/errqueue.h>
84#include <linux/net_tstamp.h>
85#include <linux/percpu.h>
86#ifdef CONFIG_INET
87#include <net/inet_common.h>
88#endif
89#include <linux/bpf.h>
90#include <net/compat.h>
91
92#include "internal.h"
93
94/*
95 Assumptions:
96 - if device has no dev->hard_header routine, it adds and removes ll header
97 inside itself. In this case ll header is invisible outside of device,
98 but higher levels still should reserve dev->hard_header_len.
99 Some devices are enough clever to reallocate skb, when header
100 will not fit to reserved space (tunnel), another ones are silly
101 (PPP).
102 - packet socket receives packets with pulled ll header,
103 so that SOCK_RAW should push it back.
104
105On receive:
106-----------
107
108Incoming, dev->hard_header!=NULL
109 mac_header -> ll header
110 data -> data
111
112Outgoing, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> ll header
115
116Incoming, dev->hard_header==NULL
117 mac_header -> UNKNOWN position. It is very likely, that it points to ll
118 header. PPP makes it, that is wrong, because introduce
119 assymetry between rx and tx paths.
120 data -> data
121
122Outgoing, dev->hard_header==NULL
123 mac_header -> data. ll header is still not built!
124 data -> data
125
126Resume
127 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
128
129
130On transmit:
131------------
132
133dev->hard_header != NULL
134 mac_header -> ll header
135 data -> ll header
136
137dev->hard_header == NULL (ll header is added by device, we cannot control it)
138 mac_header -> data
139 data -> data
140
141 We should set nh.raw on output to correct posistion,
142 packet classifier depends on it.
143 */
144
145/* Private packet socket structures. */
146
147/* identical to struct packet_mreq except it has
148 * a longer address field.
149 */
150struct packet_mreq_max {
151 int mr_ifindex;
152 unsigned short mr_type;
153 unsigned short mr_alen;
154 unsigned char mr_address[MAX_ADDR_LEN];
155};
156
157union tpacket_uhdr {
158 struct tpacket_hdr *h1;
159 struct tpacket2_hdr *h2;
160 struct tpacket3_hdr *h3;
161 void *raw;
162};
163
164static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
165 int closing, int tx_ring);
166
167#define V3_ALIGNMENT (8)
168
169#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
170
171#define BLK_PLUS_PRIV(sz_of_priv) \
172 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
173
174#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
175#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
176#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
177#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
178#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
179#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
180#define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
181
182struct packet_sock;
183static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
184 struct packet_type *pt, struct net_device *orig_dev);
185
186static void *packet_previous_frame(struct packet_sock *po,
187 struct packet_ring_buffer *rb,
188 int status);
189static void packet_increment_head(struct packet_ring_buffer *buff);
190static int prb_curr_blk_in_use(struct tpacket_block_desc *);
191static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
192 struct packet_sock *);
193static void prb_retire_current_block(struct tpacket_kbdq_core *,
194 struct packet_sock *, unsigned int status);
195static int prb_queue_frozen(struct tpacket_kbdq_core *);
196static void prb_open_block(struct tpacket_kbdq_core *,
197 struct tpacket_block_desc *);
198static void prb_retire_rx_blk_timer_expired(struct timer_list *);
199static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
200static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
201static void prb_clear_rxhash(struct tpacket_kbdq_core *,
202 struct tpacket3_hdr *);
203static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
204 struct tpacket3_hdr *);
205static void packet_flush_mclist(struct sock *sk);
206static u16 packet_pick_tx_queue(struct sk_buff *skb);
207
208struct packet_skb_cb {
209 union {
210 struct sockaddr_pkt pkt;
211 union {
212 /* Trick: alias skb original length with
213 * ll.sll_family and ll.protocol in order
214 * to save room.
215 */
216 unsigned int origlen;
217 struct sockaddr_ll ll;
218 };
219 } sa;
220};
221
222#define vio_le() virtio_legacy_is_little_endian()
223
224#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
225
226#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
227#define GET_PBLOCK_DESC(x, bid) \
228 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
229#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
230 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
231#define GET_NEXT_PRB_BLK_NUM(x) \
232 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
233 ((x)->kactive_blk_num+1) : 0)
234
235static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
236static void __fanout_link(struct sock *sk, struct packet_sock *po);
237
238static int packet_direct_xmit(struct sk_buff *skb)
239{
240 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
241}
242
243static struct net_device *packet_cached_dev_get(struct packet_sock *po)
244{
245 struct net_device *dev;
246
247 rcu_read_lock();
248 dev = rcu_dereference(po->cached_dev);
249 if (likely(dev))
250 dev_hold(dev);
251 rcu_read_unlock();
252
253 return dev;
254}
255
256static void packet_cached_dev_assign(struct packet_sock *po,
257 struct net_device *dev)
258{
259 rcu_assign_pointer(po->cached_dev, dev);
260}
261
262static void packet_cached_dev_reset(struct packet_sock *po)
263{
264 RCU_INIT_POINTER(po->cached_dev, NULL);
265}
266
267static bool packet_use_direct_xmit(const struct packet_sock *po)
268{
269 return po->xmit == packet_direct_xmit;
270}
271
272static u16 packet_pick_tx_queue(struct sk_buff *skb)
273{
274 struct net_device *dev = skb->dev;
275 const struct net_device_ops *ops = dev->netdev_ops;
276 int cpu = raw_smp_processor_id();
277 u16 queue_index;
278
279#ifdef CONFIG_XPS
280 skb->sender_cpu = cpu + 1;
281#endif
282 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
283 if (ops->ndo_select_queue) {
284 queue_index = ops->ndo_select_queue(dev, skb, NULL);
285 queue_index = netdev_cap_txqueue(dev, queue_index);
286 } else {
287 queue_index = netdev_pick_tx(dev, skb, NULL);
288 }
289
290 return queue_index;
291}
292
293/* __register_prot_hook must be invoked through register_prot_hook
294 * or from a context in which asynchronous accesses to the packet
295 * socket is not possible (packet_create()).
296 */
297static void __register_prot_hook(struct sock *sk)
298{
299 struct packet_sock *po = pkt_sk(sk);
300
301 if (!po->running) {
302 if (po->fanout)
303 __fanout_link(sk, po);
304 else
305 dev_add_pack(&po->prot_hook);
306
307 sock_hold(sk);
308 po->running = 1;
309 }
310}
311
312static void register_prot_hook(struct sock *sk)
313{
314 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
315 __register_prot_hook(sk);
316}
317
318/* If the sync parameter is true, we will temporarily drop
319 * the po->bind_lock and do a synchronize_net to make sure no
320 * asynchronous packet processing paths still refer to the elements
321 * of po->prot_hook. If the sync parameter is false, it is the
322 * callers responsibility to take care of this.
323 */
324static void __unregister_prot_hook(struct sock *sk, bool sync)
325{
326 struct packet_sock *po = pkt_sk(sk);
327
328 lockdep_assert_held_once(&po->bind_lock);
329
330 po->running = 0;
331
332 if (po->fanout)
333 __fanout_unlink(sk, po);
334 else
335 __dev_remove_pack(&po->prot_hook);
336
337 __sock_put(sk);
338
339 if (sync) {
340 spin_unlock(&po->bind_lock);
341 synchronize_net();
342 spin_lock(&po->bind_lock);
343 }
344}
345
346static void unregister_prot_hook(struct sock *sk, bool sync)
347{
348 struct packet_sock *po = pkt_sk(sk);
349
350 if (po->running)
351 __unregister_prot_hook(sk, sync);
352}
353
354static inline struct page * __pure pgv_to_page(void *addr)
355{
356 if (is_vmalloc_addr(addr))
357 return vmalloc_to_page(addr);
358 return virt_to_page(addr);
359}
360
361static void __packet_set_status(struct packet_sock *po, void *frame, int status)
362{
363 union tpacket_uhdr h;
364
365 h.raw = frame;
366 switch (po->tp_version) {
367 case TPACKET_V1:
368 h.h1->tp_status = status;
369 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
370 break;
371 case TPACKET_V2:
372 h.h2->tp_status = status;
373 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
374 break;
375 case TPACKET_V3:
376 h.h3->tp_status = status;
377 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
378 break;
379 default:
380 WARN(1, "TPACKET version not supported.\n");
381 BUG();
382 }
383
384 smp_wmb();
385}
386
387static int __packet_get_status(const struct packet_sock *po, void *frame)
388{
389 union tpacket_uhdr h;
390
391 smp_rmb();
392
393 h.raw = frame;
394 switch (po->tp_version) {
395 case TPACKET_V1:
396 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
397 return h.h1->tp_status;
398 case TPACKET_V2:
399 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
400 return h.h2->tp_status;
401 case TPACKET_V3:
402 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
403 return h.h3->tp_status;
404 default:
405 WARN(1, "TPACKET version not supported.\n");
406 BUG();
407 return 0;
408 }
409}
410
411static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
412 unsigned int flags)
413{
414 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
415
416 if (shhwtstamps &&
417 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
418 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
419 return TP_STATUS_TS_RAW_HARDWARE;
420
421 if (ktime_to_timespec_cond(skb->tstamp, ts))
422 return TP_STATUS_TS_SOFTWARE;
423
424 return 0;
425}
426
427static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
428 struct sk_buff *skb)
429{
430 union tpacket_uhdr h;
431 struct timespec ts;
432 __u32 ts_status;
433
434 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
435 return 0;
436
437 h.raw = frame;
438 switch (po->tp_version) {
439 case TPACKET_V1:
440 h.h1->tp_sec = ts.tv_sec;
441 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
442 break;
443 case TPACKET_V2:
444 h.h2->tp_sec = ts.tv_sec;
445 h.h2->tp_nsec = ts.tv_nsec;
446 break;
447 case TPACKET_V3:
448 h.h3->tp_sec = ts.tv_sec;
449 h.h3->tp_nsec = ts.tv_nsec;
450 break;
451 default:
452 WARN(1, "TPACKET version not supported.\n");
453 BUG();
454 }
455
456 /* one flush is safe, as both fields always lie on the same cacheline */
457 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
458 smp_wmb();
459
460 return ts_status;
461}
462
463static void *packet_lookup_frame(const struct packet_sock *po,
464 const struct packet_ring_buffer *rb,
465 unsigned int position,
466 int status)
467{
468 unsigned int pg_vec_pos, frame_offset;
469 union tpacket_uhdr h;
470
471 pg_vec_pos = position / rb->frames_per_block;
472 frame_offset = position % rb->frames_per_block;
473
474 h.raw = rb->pg_vec[pg_vec_pos].buffer +
475 (frame_offset * rb->frame_size);
476
477 if (status != __packet_get_status(po, h.raw))
478 return NULL;
479
480 return h.raw;
481}
482
483static void *packet_current_frame(struct packet_sock *po,
484 struct packet_ring_buffer *rb,
485 int status)
486{
487 return packet_lookup_frame(po, rb, rb->head, status);
488}
489
490static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
491{
492 del_timer_sync(&pkc->retire_blk_timer);
493}
494
495static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
496 struct sk_buff_head *rb_queue)
497{
498 struct tpacket_kbdq_core *pkc;
499
500 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
501
502 spin_lock_bh(&rb_queue->lock);
503 pkc->delete_blk_timer = 1;
504 spin_unlock_bh(&rb_queue->lock);
505
506 prb_del_retire_blk_timer(pkc);
507}
508
509static void prb_setup_retire_blk_timer(struct packet_sock *po)
510{
511 struct tpacket_kbdq_core *pkc;
512
513 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
514 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
515 0);
516 pkc->retire_blk_timer.expires = jiffies;
517}
518
519static int prb_calc_retire_blk_tmo(struct packet_sock *po,
520 int blk_size_in_bytes)
521{
522 struct net_device *dev;
523 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
524 struct ethtool_link_ksettings ecmd;
525 int err;
526
527 rtnl_lock();
528 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
529 if (unlikely(!dev)) {
530 rtnl_unlock();
531 return DEFAULT_PRB_RETIRE_TOV;
532 }
533 err = __ethtool_get_link_ksettings(dev, &ecmd);
534 rtnl_unlock();
535 if (!err) {
536 /*
537 * If the link speed is so slow you don't really
538 * need to worry about perf anyways
539 */
540 if (ecmd.base.speed < SPEED_1000 ||
541 ecmd.base.speed == SPEED_UNKNOWN) {
542 return DEFAULT_PRB_RETIRE_TOV;
543 } else {
544 msec = 1;
545 div = ecmd.base.speed / 1000;
546 }
547 }
548
549 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
550
551 if (div)
552 mbits /= div;
553
554 tmo = mbits * msec;
555
556 if (div)
557 return tmo+1;
558 return tmo;
559}
560
561static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
562 union tpacket_req_u *req_u)
563{
564 p1->feature_req_word = req_u->req3.tp_feature_req_word;
565}
566
567static void init_prb_bdqc(struct packet_sock *po,
568 struct packet_ring_buffer *rb,
569 struct pgv *pg_vec,
570 union tpacket_req_u *req_u)
571{
572 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
573 struct tpacket_block_desc *pbd;
574
575 memset(p1, 0x0, sizeof(*p1));
576
577 p1->knxt_seq_num = 1;
578 p1->pkbdq = pg_vec;
579 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
580 p1->pkblk_start = pg_vec[0].buffer;
581 p1->kblk_size = req_u->req3.tp_block_size;
582 p1->knum_blocks = req_u->req3.tp_block_nr;
583 p1->hdrlen = po->tp_hdrlen;
584 p1->version = po->tp_version;
585 p1->last_kactive_blk_num = 0;
586 po->stats.stats3.tp_freeze_q_cnt = 0;
587 if (req_u->req3.tp_retire_blk_tov)
588 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
589 else
590 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
591 req_u->req3.tp_block_size);
592 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
593 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
594
595 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
596 prb_init_ft_ops(p1, req_u);
597 prb_setup_retire_blk_timer(po);
598 prb_open_block(p1, pbd);
599}
600
601/* Do NOT update the last_blk_num first.
602 * Assumes sk_buff_head lock is held.
603 */
604static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
605{
606 mod_timer(&pkc->retire_blk_timer,
607 jiffies + pkc->tov_in_jiffies);
608 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
609}
610
611/*
612 * Timer logic:
613 * 1) We refresh the timer only when we open a block.
614 * By doing this we don't waste cycles refreshing the timer
615 * on packet-by-packet basis.
616 *
617 * With a 1MB block-size, on a 1Gbps line, it will take
618 * i) ~8 ms to fill a block + ii) memcpy etc.
619 * In this cut we are not accounting for the memcpy time.
620 *
621 * So, if the user sets the 'tmo' to 10ms then the timer
622 * will never fire while the block is still getting filled
623 * (which is what we want). However, the user could choose
624 * to close a block early and that's fine.
625 *
626 * But when the timer does fire, we check whether or not to refresh it.
627 * Since the tmo granularity is in msecs, it is not too expensive
628 * to refresh the timer, lets say every '8' msecs.
629 * Either the user can set the 'tmo' or we can derive it based on
630 * a) line-speed and b) block-size.
631 * prb_calc_retire_blk_tmo() calculates the tmo.
632 *
633 */
634static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
635{
636 struct packet_sock *po =
637 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
638 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
639 unsigned int frozen;
640 struct tpacket_block_desc *pbd;
641
642 spin_lock(&po->sk.sk_receive_queue.lock);
643
644 frozen = prb_queue_frozen(pkc);
645 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
646
647 if (unlikely(pkc->delete_blk_timer))
648 goto out;
649
650 /* We only need to plug the race when the block is partially filled.
651 * tpacket_rcv:
652 * lock(); increment BLOCK_NUM_PKTS; unlock()
653 * copy_bits() is in progress ...
654 * timer fires on other cpu:
655 * we can't retire the current block because copy_bits
656 * is in progress.
657 *
658 */
659 if (BLOCK_NUM_PKTS(pbd)) {
660 while (atomic_read(&pkc->blk_fill_in_prog)) {
661 /* Waiting for skb_copy_bits to finish... */
662 cpu_relax();
663 }
664 }
665
666 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
667 if (!frozen) {
668 if (!BLOCK_NUM_PKTS(pbd)) {
669 /* An empty block. Just refresh the timer. */
670 goto refresh_timer;
671 }
672 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
673 if (!prb_dispatch_next_block(pkc, po))
674 goto refresh_timer;
675 else
676 goto out;
677 } else {
678 /* Case 1. Queue was frozen because user-space was
679 * lagging behind.
680 */
681 if (prb_curr_blk_in_use(pbd)) {
682 /*
683 * Ok, user-space is still behind.
684 * So just refresh the timer.
685 */
686 goto refresh_timer;
687 } else {
688 /* Case 2. queue was frozen,user-space caught up,
689 * now the link went idle && the timer fired.
690 * We don't have a block to close.So we open this
691 * block and restart the timer.
692 * opening a block thaws the queue,restarts timer
693 * Thawing/timer-refresh is a side effect.
694 */
695 prb_open_block(pkc, pbd);
696 goto out;
697 }
698 }
699 }
700
701refresh_timer:
702 _prb_refresh_rx_retire_blk_timer(pkc);
703
704out:
705 spin_unlock(&po->sk.sk_receive_queue.lock);
706}
707
708static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
709 struct tpacket_block_desc *pbd1, __u32 status)
710{
711 /* Flush everything minus the block header */
712
713#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
714 u8 *start, *end;
715
716 start = (u8 *)pbd1;
717
718 /* Skip the block header(we know header WILL fit in 4K) */
719 start += PAGE_SIZE;
720
721 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
722 for (; start < end; start += PAGE_SIZE)
723 flush_dcache_page(pgv_to_page(start));
724
725 smp_wmb();
726#endif
727
728 /* Now update the block status. */
729
730 BLOCK_STATUS(pbd1) = status;
731
732 /* Flush the block header */
733
734#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
735 start = (u8 *)pbd1;
736 flush_dcache_page(pgv_to_page(start));
737
738 smp_wmb();
739#endif
740}
741
742/*
743 * Side effect:
744 *
745 * 1) flush the block
746 * 2) Increment active_blk_num
747 *
748 * Note:We DONT refresh the timer on purpose.
749 * Because almost always the next block will be opened.
750 */
751static void prb_close_block(struct tpacket_kbdq_core *pkc1,
752 struct tpacket_block_desc *pbd1,
753 struct packet_sock *po, unsigned int stat)
754{
755 __u32 status = TP_STATUS_USER | stat;
756
757 struct tpacket3_hdr *last_pkt;
758 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
759 struct sock *sk = &po->sk;
760
761 if (atomic_read(&po->tp_drops))
762 status |= TP_STATUS_LOSING;
763
764 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
765 last_pkt->tp_next_offset = 0;
766
767 /* Get the ts of the last pkt */
768 if (BLOCK_NUM_PKTS(pbd1)) {
769 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
770 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
771 } else {
772 /* Ok, we tmo'd - so get the current time.
773 *
774 * It shouldn't really happen as we don't close empty
775 * blocks. See prb_retire_rx_blk_timer_expired().
776 */
777 struct timespec ts;
778 getnstimeofday(&ts);
779 h1->ts_last_pkt.ts_sec = ts.tv_sec;
780 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
781 }
782
783 smp_wmb();
784
785 /* Flush the block */
786 prb_flush_block(pkc1, pbd1, status);
787
788 sk->sk_data_ready(sk);
789
790 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
791}
792
793static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
794{
795 pkc->reset_pending_on_curr_blk = 0;
796}
797
798/*
799 * Side effect of opening a block:
800 *
801 * 1) prb_queue is thawed.
802 * 2) retire_blk_timer is refreshed.
803 *
804 */
805static void prb_open_block(struct tpacket_kbdq_core *pkc1,
806 struct tpacket_block_desc *pbd1)
807{
808 struct timespec ts;
809 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
810
811 smp_rmb();
812
813 /* We could have just memset this but we will lose the
814 * flexibility of making the priv area sticky
815 */
816
817 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
818 BLOCK_NUM_PKTS(pbd1) = 0;
819 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
820
821 getnstimeofday(&ts);
822
823 h1->ts_first_pkt.ts_sec = ts.tv_sec;
824 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
825
826 pkc1->pkblk_start = (char *)pbd1;
827 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
828
829 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
830 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
831
832 pbd1->version = pkc1->version;
833 pkc1->prev = pkc1->nxt_offset;
834 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
835
836 prb_thaw_queue(pkc1);
837 _prb_refresh_rx_retire_blk_timer(pkc1);
838
839 smp_wmb();
840}
841
842/*
843 * Queue freeze logic:
844 * 1) Assume tp_block_nr = 8 blocks.
845 * 2) At time 't0', user opens Rx ring.
846 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
847 * 4) user-space is either sleeping or processing block '0'.
848 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
849 * it will close block-7,loop around and try to fill block '0'.
850 * call-flow:
851 * __packet_lookup_frame_in_block
852 * prb_retire_current_block()
853 * prb_dispatch_next_block()
854 * |->(BLOCK_STATUS == USER) evaluates to true
855 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
856 * 6) Now there are two cases:
857 * 6.1) Link goes idle right after the queue is frozen.
858 * But remember, the last open_block() refreshed the timer.
859 * When this timer expires,it will refresh itself so that we can
860 * re-open block-0 in near future.
861 * 6.2) Link is busy and keeps on receiving packets. This is a simple
862 * case and __packet_lookup_frame_in_block will check if block-0
863 * is free and can now be re-used.
864 */
865static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
866 struct packet_sock *po)
867{
868 pkc->reset_pending_on_curr_blk = 1;
869 po->stats.stats3.tp_freeze_q_cnt++;
870}
871
872#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
873
874/*
875 * If the next block is free then we will dispatch it
876 * and return a good offset.
877 * Else, we will freeze the queue.
878 * So, caller must check the return value.
879 */
880static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
881 struct packet_sock *po)
882{
883 struct tpacket_block_desc *pbd;
884
885 smp_rmb();
886
887 /* 1. Get current block num */
888 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
889
890 /* 2. If this block is currently in_use then freeze the queue */
891 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
892 prb_freeze_queue(pkc, po);
893 return NULL;
894 }
895
896 /*
897 * 3.
898 * open this block and return the offset where the first packet
899 * needs to get stored.
900 */
901 prb_open_block(pkc, pbd);
902 return (void *)pkc->nxt_offset;
903}
904
905static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
906 struct packet_sock *po, unsigned int status)
907{
908 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
909
910 /* retire/close the current block */
911 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
912 /*
913 * Plug the case where copy_bits() is in progress on
914 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
915 * have space to copy the pkt in the current block and
916 * called prb_retire_current_block()
917 *
918 * We don't need to worry about the TMO case because
919 * the timer-handler already handled this case.
920 */
921 if (!(status & TP_STATUS_BLK_TMO)) {
922 while (atomic_read(&pkc->blk_fill_in_prog)) {
923 /* Waiting for skb_copy_bits to finish... */
924 cpu_relax();
925 }
926 }
927 prb_close_block(pkc, pbd, po, status);
928 return;
929 }
930}
931
932static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
933{
934 return TP_STATUS_USER & BLOCK_STATUS(pbd);
935}
936
937static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
938{
939 return pkc->reset_pending_on_curr_blk;
940}
941
942static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
943{
944 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
945 atomic_dec(&pkc->blk_fill_in_prog);
946}
947
948static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
949 struct tpacket3_hdr *ppd)
950{
951 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
952}
953
954static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
955 struct tpacket3_hdr *ppd)
956{
957 ppd->hv1.tp_rxhash = 0;
958}
959
960static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
961 struct tpacket3_hdr *ppd)
962{
963 if (skb_vlan_tag_present(pkc->skb)) {
964 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
965 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
966 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
967 } else {
968 ppd->hv1.tp_vlan_tci = 0;
969 ppd->hv1.tp_vlan_tpid = 0;
970 ppd->tp_status = TP_STATUS_AVAILABLE;
971 }
972}
973
974static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
975 struct tpacket3_hdr *ppd)
976{
977 ppd->hv1.tp_padding = 0;
978 prb_fill_vlan_info(pkc, ppd);
979
980 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
981 prb_fill_rxhash(pkc, ppd);
982 else
983 prb_clear_rxhash(pkc, ppd);
984}
985
986static void prb_fill_curr_block(char *curr,
987 struct tpacket_kbdq_core *pkc,
988 struct tpacket_block_desc *pbd,
989 unsigned int len)
990{
991 struct tpacket3_hdr *ppd;
992
993 ppd = (struct tpacket3_hdr *)curr;
994 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
995 pkc->prev = curr;
996 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
997 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
998 BLOCK_NUM_PKTS(pbd) += 1;
999 atomic_inc(&pkc->blk_fill_in_prog);
1000 prb_run_all_ft_ops(pkc, ppd);
1001}
1002
1003/* Assumes caller has the sk->rx_queue.lock */
1004static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1005 struct sk_buff *skb,
1006 unsigned int len
1007 )
1008{
1009 struct tpacket_kbdq_core *pkc;
1010 struct tpacket_block_desc *pbd;
1011 char *curr, *end;
1012
1013 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1014 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1015
1016 /* Queue is frozen when user space is lagging behind */
1017 if (prb_queue_frozen(pkc)) {
1018 /*
1019 * Check if that last block which caused the queue to freeze,
1020 * is still in_use by user-space.
1021 */
1022 if (prb_curr_blk_in_use(pbd)) {
1023 /* Can't record this packet */
1024 return NULL;
1025 } else {
1026 /*
1027 * Ok, the block was released by user-space.
1028 * Now let's open that block.
1029 * opening a block also thaws the queue.
1030 * Thawing is a side effect.
1031 */
1032 prb_open_block(pkc, pbd);
1033 }
1034 }
1035
1036 smp_mb();
1037 curr = pkc->nxt_offset;
1038 pkc->skb = skb;
1039 end = (char *)pbd + pkc->kblk_size;
1040
1041 /* first try the current block */
1042 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1043 prb_fill_curr_block(curr, pkc, pbd, len);
1044 return (void *)curr;
1045 }
1046
1047 /* Ok, close the current block */
1048 prb_retire_current_block(pkc, po, 0);
1049
1050 /* Now, try to dispatch the next block */
1051 curr = (char *)prb_dispatch_next_block(pkc, po);
1052 if (curr) {
1053 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1054 prb_fill_curr_block(curr, pkc, pbd, len);
1055 return (void *)curr;
1056 }
1057
1058 /*
1059 * No free blocks are available.user_space hasn't caught up yet.
1060 * Queue was just frozen and now this packet will get dropped.
1061 */
1062 return NULL;
1063}
1064
1065static void *packet_current_rx_frame(struct packet_sock *po,
1066 struct sk_buff *skb,
1067 int status, unsigned int len)
1068{
1069 char *curr = NULL;
1070 switch (po->tp_version) {
1071 case TPACKET_V1:
1072 case TPACKET_V2:
1073 curr = packet_lookup_frame(po, &po->rx_ring,
1074 po->rx_ring.head, status);
1075 return curr;
1076 case TPACKET_V3:
1077 return __packet_lookup_frame_in_block(po, skb, len);
1078 default:
1079 WARN(1, "TPACKET version not supported\n");
1080 BUG();
1081 return NULL;
1082 }
1083}
1084
1085static void *prb_lookup_block(const struct packet_sock *po,
1086 const struct packet_ring_buffer *rb,
1087 unsigned int idx,
1088 int status)
1089{
1090 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1091 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1092
1093 if (status != BLOCK_STATUS(pbd))
1094 return NULL;
1095 return pbd;
1096}
1097
1098static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1099{
1100 unsigned int prev;
1101 if (rb->prb_bdqc.kactive_blk_num)
1102 prev = rb->prb_bdqc.kactive_blk_num-1;
1103 else
1104 prev = rb->prb_bdqc.knum_blocks-1;
1105 return prev;
1106}
1107
1108/* Assumes caller has held the rx_queue.lock */
1109static void *__prb_previous_block(struct packet_sock *po,
1110 struct packet_ring_buffer *rb,
1111 int status)
1112{
1113 unsigned int previous = prb_previous_blk_num(rb);
1114 return prb_lookup_block(po, rb, previous, status);
1115}
1116
1117static void *packet_previous_rx_frame(struct packet_sock *po,
1118 struct packet_ring_buffer *rb,
1119 int status)
1120{
1121 if (po->tp_version <= TPACKET_V2)
1122 return packet_previous_frame(po, rb, status);
1123
1124 return __prb_previous_block(po, rb, status);
1125}
1126
1127static void packet_increment_rx_head(struct packet_sock *po,
1128 struct packet_ring_buffer *rb)
1129{
1130 switch (po->tp_version) {
1131 case TPACKET_V1:
1132 case TPACKET_V2:
1133 return packet_increment_head(rb);
1134 case TPACKET_V3:
1135 default:
1136 WARN(1, "TPACKET version not supported.\n");
1137 BUG();
1138 return;
1139 }
1140}
1141
1142static void *packet_previous_frame(struct packet_sock *po,
1143 struct packet_ring_buffer *rb,
1144 int status)
1145{
1146 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1147 return packet_lookup_frame(po, rb, previous, status);
1148}
1149
1150static void packet_increment_head(struct packet_ring_buffer *buff)
1151{
1152 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1153}
1154
1155static void packet_inc_pending(struct packet_ring_buffer *rb)
1156{
1157 this_cpu_inc(*rb->pending_refcnt);
1158}
1159
1160static void packet_dec_pending(struct packet_ring_buffer *rb)
1161{
1162 this_cpu_dec(*rb->pending_refcnt);
1163}
1164
1165static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1166{
1167 unsigned int refcnt = 0;
1168 int cpu;
1169
1170 /* We don't use pending refcount in rx_ring. */
1171 if (rb->pending_refcnt == NULL)
1172 return 0;
1173
1174 for_each_possible_cpu(cpu)
1175 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1176
1177 return refcnt;
1178}
1179
1180static int packet_alloc_pending(struct packet_sock *po)
1181{
1182 po->rx_ring.pending_refcnt = NULL;
1183
1184 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1185 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1186 return -ENOBUFS;
1187
1188 return 0;
1189}
1190
1191static void packet_free_pending(struct packet_sock *po)
1192{
1193 free_percpu(po->tx_ring.pending_refcnt);
1194}
1195
1196#define ROOM_POW_OFF 2
1197#define ROOM_NONE 0x0
1198#define ROOM_LOW 0x1
1199#define ROOM_NORMAL 0x2
1200
1201static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1202{
1203 int idx, len;
1204
1205 len = READ_ONCE(po->rx_ring.frame_max) + 1;
1206 idx = READ_ONCE(po->rx_ring.head);
1207 if (pow_off)
1208 idx += len >> pow_off;
1209 if (idx >= len)
1210 idx -= len;
1211 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1212}
1213
1214static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1215{
1216 int idx, len;
1217
1218 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1219 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1220 if (pow_off)
1221 idx += len >> pow_off;
1222 if (idx >= len)
1223 idx -= len;
1224 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1225}
1226
1227static int __packet_rcv_has_room(const struct packet_sock *po,
1228 const struct sk_buff *skb)
1229{
1230 const struct sock *sk = &po->sk;
1231 int ret = ROOM_NONE;
1232
1233 if (po->prot_hook.func != tpacket_rcv) {
1234 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1235 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1236 - (skb ? skb->truesize : 0);
1237
1238 if (avail > (rcvbuf >> ROOM_POW_OFF))
1239 return ROOM_NORMAL;
1240 else if (avail > 0)
1241 return ROOM_LOW;
1242 else
1243 return ROOM_NONE;
1244 }
1245
1246 if (po->tp_version == TPACKET_V3) {
1247 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1248 ret = ROOM_NORMAL;
1249 else if (__tpacket_v3_has_room(po, 0))
1250 ret = ROOM_LOW;
1251 } else {
1252 if (__tpacket_has_room(po, ROOM_POW_OFF))
1253 ret = ROOM_NORMAL;
1254 else if (__tpacket_has_room(po, 0))
1255 ret = ROOM_LOW;
1256 }
1257
1258 return ret;
1259}
1260
1261static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1262{
1263 int pressure, ret;
1264
1265 ret = __packet_rcv_has_room(po, skb);
1266 pressure = ret != ROOM_NORMAL;
1267
1268 if (READ_ONCE(po->pressure) != pressure)
1269 WRITE_ONCE(po->pressure, pressure);
1270
1271 return ret;
1272}
1273
1274static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1275{
1276 if (READ_ONCE(po->pressure) &&
1277 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1278 WRITE_ONCE(po->pressure, 0);
1279}
1280
1281static void packet_sock_destruct(struct sock *sk)
1282{
1283 skb_queue_purge(&sk->sk_error_queue);
1284
1285 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1286 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1287
1288 if (!sock_flag(sk, SOCK_DEAD)) {
1289 pr_err("Attempt to release alive packet socket: %p\n", sk);
1290 return;
1291 }
1292
1293 sk_refcnt_debug_dec(sk);
1294}
1295
1296static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1297{
1298 u32 rxhash;
1299 int i, count = 0;
1300
1301 rxhash = skb_get_hash(skb);
1302 for (i = 0; i < ROLLOVER_HLEN; i++)
1303 if (po->rollover->history[i] == rxhash)
1304 count++;
1305
1306 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1307 return count > (ROLLOVER_HLEN >> 1);
1308}
1309
1310static unsigned int fanout_demux_hash(struct packet_fanout *f,
1311 struct sk_buff *skb,
1312 unsigned int num)
1313{
1314 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1315}
1316
1317static unsigned int fanout_demux_lb(struct packet_fanout *f,
1318 struct sk_buff *skb,
1319 unsigned int num)
1320{
1321 unsigned int val = atomic_inc_return(&f->rr_cur);
1322
1323 return val % num;
1324}
1325
1326static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1327 struct sk_buff *skb,
1328 unsigned int num)
1329{
1330 return smp_processor_id() % num;
1331}
1332
1333static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1334 struct sk_buff *skb,
1335 unsigned int num)
1336{
1337 return prandom_u32_max(num);
1338}
1339
1340static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1341 struct sk_buff *skb,
1342 unsigned int idx, bool try_self,
1343 unsigned int num)
1344{
1345 struct packet_sock *po, *po_next, *po_skip = NULL;
1346 unsigned int i, j, room = ROOM_NONE;
1347
1348 po = pkt_sk(f->arr[idx]);
1349
1350 if (try_self) {
1351 room = packet_rcv_has_room(po, skb);
1352 if (room == ROOM_NORMAL ||
1353 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1354 return idx;
1355 po_skip = po;
1356 }
1357
1358 i = j = min_t(int, po->rollover->sock, num - 1);
1359 do {
1360 po_next = pkt_sk(f->arr[i]);
1361 if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1362 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1363 if (i != j)
1364 po->rollover->sock = i;
1365 atomic_long_inc(&po->rollover->num);
1366 if (room == ROOM_LOW)
1367 atomic_long_inc(&po->rollover->num_huge);
1368 return i;
1369 }
1370
1371 if (++i == num)
1372 i = 0;
1373 } while (i != j);
1374
1375 atomic_long_inc(&po->rollover->num_failed);
1376 return idx;
1377}
1378
1379static unsigned int fanout_demux_qm(struct packet_fanout *f,
1380 struct sk_buff *skb,
1381 unsigned int num)
1382{
1383 return skb_get_queue_mapping(skb) % num;
1384}
1385
1386static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1387 struct sk_buff *skb,
1388 unsigned int num)
1389{
1390 struct bpf_prog *prog;
1391 unsigned int ret = 0;
1392
1393 rcu_read_lock();
1394 prog = rcu_dereference(f->bpf_prog);
1395 if (prog)
1396 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1397 rcu_read_unlock();
1398
1399 return ret;
1400}
1401
1402static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1403{
1404 return f->flags & (flag >> 8);
1405}
1406
1407static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1408 struct packet_type *pt, struct net_device *orig_dev)
1409{
1410 struct packet_fanout *f = pt->af_packet_priv;
1411 unsigned int num = READ_ONCE(f->num_members);
1412 struct net *net = read_pnet(&f->net);
1413 struct packet_sock *po;
1414 unsigned int idx;
1415
1416 if (!net_eq(dev_net(dev), net) || !num) {
1417 kfree_skb(skb);
1418 return 0;
1419 }
1420
1421 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1422 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1423 if (!skb)
1424 return 0;
1425 }
1426 switch (f->type) {
1427 case PACKET_FANOUT_HASH:
1428 default:
1429 idx = fanout_demux_hash(f, skb, num);
1430 break;
1431 case PACKET_FANOUT_LB:
1432 idx = fanout_demux_lb(f, skb, num);
1433 break;
1434 case PACKET_FANOUT_CPU:
1435 idx = fanout_demux_cpu(f, skb, num);
1436 break;
1437 case PACKET_FANOUT_RND:
1438 idx = fanout_demux_rnd(f, skb, num);
1439 break;
1440 case PACKET_FANOUT_QM:
1441 idx = fanout_demux_qm(f, skb, num);
1442 break;
1443 case PACKET_FANOUT_ROLLOVER:
1444 idx = fanout_demux_rollover(f, skb, 0, false, num);
1445 break;
1446 case PACKET_FANOUT_CBPF:
1447 case PACKET_FANOUT_EBPF:
1448 idx = fanout_demux_bpf(f, skb, num);
1449 break;
1450 }
1451
1452 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1453 idx = fanout_demux_rollover(f, skb, idx, true, num);
1454
1455 po = pkt_sk(f->arr[idx]);
1456 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1457}
1458
1459DEFINE_MUTEX(fanout_mutex);
1460EXPORT_SYMBOL_GPL(fanout_mutex);
1461static LIST_HEAD(fanout_list);
1462static u16 fanout_next_id;
1463
1464static void __fanout_link(struct sock *sk, struct packet_sock *po)
1465{
1466 struct packet_fanout *f = po->fanout;
1467
1468 spin_lock(&f->lock);
1469 f->arr[f->num_members] = sk;
1470 smp_wmb();
1471 f->num_members++;
1472 if (f->num_members == 1)
1473 dev_add_pack(&f->prot_hook);
1474 spin_unlock(&f->lock);
1475}
1476
1477static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1478{
1479 struct packet_fanout *f = po->fanout;
1480 int i;
1481
1482 spin_lock(&f->lock);
1483 for (i = 0; i < f->num_members; i++) {
1484 if (f->arr[i] == sk)
1485 break;
1486 }
1487 BUG_ON(i >= f->num_members);
1488 f->arr[i] = f->arr[f->num_members - 1];
1489 f->num_members--;
1490 if (f->num_members == 0)
1491 __dev_remove_pack(&f->prot_hook);
1492 spin_unlock(&f->lock);
1493}
1494
1495static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1496{
1497 if (sk->sk_family != PF_PACKET)
1498 return false;
1499
1500 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1501}
1502
1503static void fanout_init_data(struct packet_fanout *f)
1504{
1505 switch (f->type) {
1506 case PACKET_FANOUT_LB:
1507 atomic_set(&f->rr_cur, 0);
1508 break;
1509 case PACKET_FANOUT_CBPF:
1510 case PACKET_FANOUT_EBPF:
1511 RCU_INIT_POINTER(f->bpf_prog, NULL);
1512 break;
1513 }
1514}
1515
1516static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1517{
1518 struct bpf_prog *old;
1519
1520 spin_lock(&f->lock);
1521 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1522 rcu_assign_pointer(f->bpf_prog, new);
1523 spin_unlock(&f->lock);
1524
1525 if (old) {
1526 synchronize_net();
1527 bpf_prog_destroy(old);
1528 }
1529}
1530
1531static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1532 unsigned int len)
1533{
1534 struct bpf_prog *new;
1535 struct sock_fprog fprog;
1536 int ret;
1537
1538 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1539 return -EPERM;
1540 if (len != sizeof(fprog))
1541 return -EINVAL;
1542 if (copy_from_user(&fprog, data, len))
1543 return -EFAULT;
1544
1545 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1546 if (ret)
1547 return ret;
1548
1549 __fanout_set_data_bpf(po->fanout, new);
1550 return 0;
1551}
1552
1553static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1554 unsigned int len)
1555{
1556 struct bpf_prog *new;
1557 u32 fd;
1558
1559 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1560 return -EPERM;
1561 if (len != sizeof(fd))
1562 return -EINVAL;
1563 if (copy_from_user(&fd, data, len))
1564 return -EFAULT;
1565
1566 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1567 if (IS_ERR(new))
1568 return PTR_ERR(new);
1569
1570 __fanout_set_data_bpf(po->fanout, new);
1571 return 0;
1572}
1573
1574static int fanout_set_data(struct packet_sock *po, char __user *data,
1575 unsigned int len)
1576{
1577 switch (po->fanout->type) {
1578 case PACKET_FANOUT_CBPF:
1579 return fanout_set_data_cbpf(po, data, len);
1580 case PACKET_FANOUT_EBPF:
1581 return fanout_set_data_ebpf(po, data, len);
1582 default:
1583 return -EINVAL;
1584 }
1585}
1586
1587static void fanout_release_data(struct packet_fanout *f)
1588{
1589 switch (f->type) {
1590 case PACKET_FANOUT_CBPF:
1591 case PACKET_FANOUT_EBPF:
1592 __fanout_set_data_bpf(f, NULL);
1593 }
1594}
1595
1596static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1597{
1598 struct packet_fanout *f;
1599
1600 list_for_each_entry(f, &fanout_list, list) {
1601 if (f->id == candidate_id &&
1602 read_pnet(&f->net) == sock_net(sk)) {
1603 return false;
1604 }
1605 }
1606 return true;
1607}
1608
1609static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1610{
1611 u16 id = fanout_next_id;
1612
1613 do {
1614 if (__fanout_id_is_free(sk, id)) {
1615 *new_id = id;
1616 fanout_next_id = id + 1;
1617 return true;
1618 }
1619
1620 id++;
1621 } while (id != fanout_next_id);
1622
1623 return false;
1624}
1625
1626static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1627{
1628 struct packet_rollover *rollover = NULL;
1629 struct packet_sock *po = pkt_sk(sk);
1630 struct packet_fanout *f, *match;
1631 u8 type = type_flags & 0xff;
1632 u8 flags = type_flags >> 8;
1633 int err;
1634
1635 switch (type) {
1636 case PACKET_FANOUT_ROLLOVER:
1637 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1638 return -EINVAL;
1639 case PACKET_FANOUT_HASH:
1640 case PACKET_FANOUT_LB:
1641 case PACKET_FANOUT_CPU:
1642 case PACKET_FANOUT_RND:
1643 case PACKET_FANOUT_QM:
1644 case PACKET_FANOUT_CBPF:
1645 case PACKET_FANOUT_EBPF:
1646 break;
1647 default:
1648 return -EINVAL;
1649 }
1650
1651 mutex_lock(&fanout_mutex);
1652
1653 err = -EALREADY;
1654 if (po->fanout)
1655 goto out;
1656
1657 if (type == PACKET_FANOUT_ROLLOVER ||
1658 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1659 err = -ENOMEM;
1660 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1661 if (!rollover)
1662 goto out;
1663 atomic_long_set(&rollover->num, 0);
1664 atomic_long_set(&rollover->num_huge, 0);
1665 atomic_long_set(&rollover->num_failed, 0);
1666 }
1667
1668 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1669 if (id != 0) {
1670 err = -EINVAL;
1671 goto out;
1672 }
1673 if (!fanout_find_new_id(sk, &id)) {
1674 err = -ENOMEM;
1675 goto out;
1676 }
1677 /* ephemeral flag for the first socket in the group: drop it */
1678 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1679 }
1680
1681 match = NULL;
1682 list_for_each_entry(f, &fanout_list, list) {
1683 if (f->id == id &&
1684 read_pnet(&f->net) == sock_net(sk)) {
1685 match = f;
1686 break;
1687 }
1688 }
1689 err = -EINVAL;
1690 if (match && match->flags != flags)
1691 goto out;
1692 if (!match) {
1693 err = -ENOMEM;
1694 match = kzalloc(sizeof(*match), GFP_KERNEL);
1695 if (!match)
1696 goto out;
1697 write_pnet(&match->net, sock_net(sk));
1698 match->id = id;
1699 match->type = type;
1700 match->flags = flags;
1701 INIT_LIST_HEAD(&match->list);
1702 spin_lock_init(&match->lock);
1703 refcount_set(&match->sk_ref, 0);
1704 fanout_init_data(match);
1705 match->prot_hook.type = po->prot_hook.type;
1706 match->prot_hook.dev = po->prot_hook.dev;
1707 match->prot_hook.func = packet_rcv_fanout;
1708 match->prot_hook.af_packet_priv = match;
1709 match->prot_hook.id_match = match_fanout_group;
1710 list_add(&match->list, &fanout_list);
1711 }
1712 err = -EINVAL;
1713
1714 spin_lock(&po->bind_lock);
1715 if (po->running &&
1716 match->type == type &&
1717 match->prot_hook.type == po->prot_hook.type &&
1718 match->prot_hook.dev == po->prot_hook.dev) {
1719 err = -ENOSPC;
1720 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1721 __dev_remove_pack(&po->prot_hook);
1722 po->fanout = match;
1723 po->rollover = rollover;
1724 rollover = NULL;
1725 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1726 __fanout_link(sk, po);
1727 err = 0;
1728 }
1729 }
1730 spin_unlock(&po->bind_lock);
1731
1732 if (err && !refcount_read(&match->sk_ref)) {
1733 list_del(&match->list);
1734 kfree(match);
1735 }
1736
1737out:
1738 kfree(rollover);
1739 mutex_unlock(&fanout_mutex);
1740 return err;
1741}
1742
1743/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1744 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1745 * It is the responsibility of the caller to call fanout_release_data() and
1746 * free the returned packet_fanout (after synchronize_net())
1747 */
1748static struct packet_fanout *fanout_release(struct sock *sk)
1749{
1750 struct packet_sock *po = pkt_sk(sk);
1751 struct packet_fanout *f;
1752
1753 mutex_lock(&fanout_mutex);
1754 f = po->fanout;
1755 if (f) {
1756 po->fanout = NULL;
1757
1758 if (refcount_dec_and_test(&f->sk_ref))
1759 list_del(&f->list);
1760 else
1761 f = NULL;
1762 }
1763 mutex_unlock(&fanout_mutex);
1764
1765 return f;
1766}
1767
1768static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1769 struct sk_buff *skb)
1770{
1771 /* Earlier code assumed this would be a VLAN pkt, double-check
1772 * this now that we have the actual packet in hand. We can only
1773 * do this check on Ethernet devices.
1774 */
1775 if (unlikely(dev->type != ARPHRD_ETHER))
1776 return false;
1777
1778 skb_reset_mac_header(skb);
1779 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1780}
1781
1782static const struct proto_ops packet_ops;
1783
1784static const struct proto_ops packet_ops_spkt;
1785
1786static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1787 struct packet_type *pt, struct net_device *orig_dev)
1788{
1789 struct sock *sk;
1790 struct sockaddr_pkt *spkt;
1791
1792 /*
1793 * When we registered the protocol we saved the socket in the data
1794 * field for just this event.
1795 */
1796
1797 sk = pt->af_packet_priv;
1798
1799 /*
1800 * Yank back the headers [hope the device set this
1801 * right or kerboom...]
1802 *
1803 * Incoming packets have ll header pulled,
1804 * push it back.
1805 *
1806 * For outgoing ones skb->data == skb_mac_header(skb)
1807 * so that this procedure is noop.
1808 */
1809
1810 if (skb->pkt_type == PACKET_LOOPBACK)
1811 goto out;
1812
1813 if (!net_eq(dev_net(dev), sock_net(sk)))
1814 goto out;
1815
1816 skb = skb_share_check(skb, GFP_ATOMIC);
1817 if (skb == NULL)
1818 goto oom;
1819
1820 /* drop any routing info */
1821 skb_dst_drop(skb);
1822
1823 /* drop conntrack reference */
1824 nf_reset_ct(skb);
1825
1826 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1827
1828 skb_push(skb, skb->data - skb_mac_header(skb));
1829
1830 /*
1831 * The SOCK_PACKET socket receives _all_ frames.
1832 */
1833
1834 spkt->spkt_family = dev->type;
1835 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1836 spkt->spkt_protocol = skb->protocol;
1837
1838 /*
1839 * Charge the memory to the socket. This is done specifically
1840 * to prevent sockets using all the memory up.
1841 */
1842
1843 if (sock_queue_rcv_skb(sk, skb) == 0)
1844 return 0;
1845
1846out:
1847 kfree_skb(skb);
1848oom:
1849 return 0;
1850}
1851
1852static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1853{
1854 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1855 sock->type == SOCK_RAW) {
1856 skb_reset_mac_header(skb);
1857 skb->protocol = dev_parse_header_protocol(skb);
1858 }
1859
1860 skb_probe_transport_header(skb);
1861}
1862
1863/*
1864 * Output a raw packet to a device layer. This bypasses all the other
1865 * protocol layers and you must therefore supply it with a complete frame
1866 */
1867
1868static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1869 size_t len)
1870{
1871 struct sock *sk = sock->sk;
1872 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1873 struct sk_buff *skb = NULL;
1874 struct net_device *dev;
1875 struct sockcm_cookie sockc;
1876 __be16 proto = 0;
1877 int err;
1878 int extra_len = 0;
1879
1880 /*
1881 * Get and verify the address.
1882 */
1883
1884 if (saddr) {
1885 if (msg->msg_namelen < sizeof(struct sockaddr))
1886 return -EINVAL;
1887 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1888 proto = saddr->spkt_protocol;
1889 } else
1890 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1891
1892 /*
1893 * Find the device first to size check it
1894 */
1895
1896 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1897retry:
1898 rcu_read_lock();
1899 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1900 err = -ENODEV;
1901 if (dev == NULL)
1902 goto out_unlock;
1903
1904 err = -ENETDOWN;
1905 if (!(dev->flags & IFF_UP))
1906 goto out_unlock;
1907
1908 /*
1909 * You may not queue a frame bigger than the mtu. This is the lowest level
1910 * raw protocol and you must do your own fragmentation at this level.
1911 */
1912
1913 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1914 if (!netif_supports_nofcs(dev)) {
1915 err = -EPROTONOSUPPORT;
1916 goto out_unlock;
1917 }
1918 extra_len = 4; /* We're doing our own CRC */
1919 }
1920
1921 err = -EMSGSIZE;
1922 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1923 goto out_unlock;
1924
1925 if (!skb) {
1926 size_t reserved = LL_RESERVED_SPACE(dev);
1927 int tlen = dev->needed_tailroom;
1928 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1929
1930 rcu_read_unlock();
1931 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1932 if (skb == NULL)
1933 return -ENOBUFS;
1934 /* FIXME: Save some space for broken drivers that write a hard
1935 * header at transmission time by themselves. PPP is the notable
1936 * one here. This should really be fixed at the driver level.
1937 */
1938 skb_reserve(skb, reserved);
1939 skb_reset_network_header(skb);
1940
1941 /* Try to align data part correctly */
1942 if (hhlen) {
1943 skb->data -= hhlen;
1944 skb->tail -= hhlen;
1945 if (len < hhlen)
1946 skb_reset_network_header(skb);
1947 }
1948 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1949 if (err)
1950 goto out_free;
1951 goto retry;
1952 }
1953
1954 if (!dev_validate_header(dev, skb->data, len)) {
1955 err = -EINVAL;
1956 goto out_unlock;
1957 }
1958 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1959 !packet_extra_vlan_len_allowed(dev, skb)) {
1960 err = -EMSGSIZE;
1961 goto out_unlock;
1962 }
1963
1964 sockcm_init(&sockc, sk);
1965 if (msg->msg_controllen) {
1966 err = sock_cmsg_send(sk, msg, &sockc);
1967 if (unlikely(err))
1968 goto out_unlock;
1969 }
1970
1971 skb->protocol = proto;
1972 skb->dev = dev;
1973 skb->priority = sk->sk_priority;
1974 skb->mark = sk->sk_mark;
1975 skb->tstamp = sockc.transmit_time;
1976
1977 skb_setup_tx_timestamp(skb, sockc.tsflags);
1978
1979 if (unlikely(extra_len == 4))
1980 skb->no_fcs = 1;
1981
1982 packet_parse_headers(skb, sock);
1983
1984 dev_queue_xmit(skb);
1985 rcu_read_unlock();
1986 return len;
1987
1988out_unlock:
1989 rcu_read_unlock();
1990out_free:
1991 kfree_skb(skb);
1992 return err;
1993}
1994
1995static unsigned int run_filter(struct sk_buff *skb,
1996 const struct sock *sk,
1997 unsigned int res)
1998{
1999 struct sk_filter *filter;
2000
2001 rcu_read_lock();
2002 filter = rcu_dereference(sk->sk_filter);
2003 if (filter != NULL)
2004 res = bpf_prog_run_clear_cb(filter->prog, skb);
2005 rcu_read_unlock();
2006
2007 return res;
2008}
2009
2010static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2011 size_t *len)
2012{
2013 struct virtio_net_hdr vnet_hdr;
2014
2015 if (*len < sizeof(vnet_hdr))
2016 return -EINVAL;
2017 *len -= sizeof(vnet_hdr);
2018
2019 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2020 return -EINVAL;
2021
2022 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2023}
2024
2025/*
2026 * This function makes lazy skb cloning in hope that most of packets
2027 * are discarded by BPF.
2028 *
2029 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2030 * and skb->cb are mangled. It works because (and until) packets
2031 * falling here are owned by current CPU. Output packets are cloned
2032 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2033 * sequencially, so that if we return skb to original state on exit,
2034 * we will not harm anyone.
2035 */
2036
2037static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2038 struct packet_type *pt, struct net_device *orig_dev)
2039{
2040 struct sock *sk;
2041 struct sockaddr_ll *sll;
2042 struct packet_sock *po;
2043 u8 *skb_head = skb->data;
2044 int skb_len = skb->len;
2045 unsigned int snaplen, res;
2046 bool is_drop_n_account = false;
2047
2048 if (skb->pkt_type == PACKET_LOOPBACK)
2049 goto drop;
2050
2051 sk = pt->af_packet_priv;
2052 po = pkt_sk(sk);
2053
2054 if (!net_eq(dev_net(dev), sock_net(sk)))
2055 goto drop;
2056
2057 skb->dev = dev;
2058
2059 if (dev->header_ops) {
2060 /* The device has an explicit notion of ll header,
2061 * exported to higher levels.
2062 *
2063 * Otherwise, the device hides details of its frame
2064 * structure, so that corresponding packet head is
2065 * never delivered to user.
2066 */
2067 if (sk->sk_type != SOCK_DGRAM)
2068 skb_push(skb, skb->data - skb_mac_header(skb));
2069 else if (skb->pkt_type == PACKET_OUTGOING) {
2070 /* Special case: outgoing packets have ll header at head */
2071 skb_pull(skb, skb_network_offset(skb));
2072 }
2073 }
2074
2075 snaplen = skb->len;
2076
2077 res = run_filter(skb, sk, snaplen);
2078 if (!res)
2079 goto drop_n_restore;
2080 if (snaplen > res)
2081 snaplen = res;
2082
2083 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2084 goto drop_n_acct;
2085
2086 if (skb_shared(skb)) {
2087 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2088 if (nskb == NULL)
2089 goto drop_n_acct;
2090
2091 if (skb_head != skb->data) {
2092 skb->data = skb_head;
2093 skb->len = skb_len;
2094 }
2095 consume_skb(skb);
2096 skb = nskb;
2097 }
2098
2099 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2100
2101 sll = &PACKET_SKB_CB(skb)->sa.ll;
2102 sll->sll_hatype = dev->type;
2103 sll->sll_pkttype = skb->pkt_type;
2104 if (unlikely(po->origdev))
2105 sll->sll_ifindex = orig_dev->ifindex;
2106 else
2107 sll->sll_ifindex = dev->ifindex;
2108
2109 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2110
2111 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2112 * Use their space for storing the original skb length.
2113 */
2114 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2115
2116 if (pskb_trim(skb, snaplen))
2117 goto drop_n_acct;
2118
2119 skb_set_owner_r(skb, sk);
2120 skb->dev = NULL;
2121 skb_dst_drop(skb);
2122
2123 /* drop conntrack reference */
2124 nf_reset_ct(skb);
2125
2126 spin_lock(&sk->sk_receive_queue.lock);
2127 po->stats.stats1.tp_packets++;
2128 sock_skb_set_dropcount(sk, skb);
2129 __skb_queue_tail(&sk->sk_receive_queue, skb);
2130 spin_unlock(&sk->sk_receive_queue.lock);
2131 sk->sk_data_ready(sk);
2132 return 0;
2133
2134drop_n_acct:
2135 is_drop_n_account = true;
2136 atomic_inc(&po->tp_drops);
2137 atomic_inc(&sk->sk_drops);
2138
2139drop_n_restore:
2140 if (skb_head != skb->data && skb_shared(skb)) {
2141 skb->data = skb_head;
2142 skb->len = skb_len;
2143 }
2144drop:
2145 if (!is_drop_n_account)
2146 consume_skb(skb);
2147 else
2148 kfree_skb(skb);
2149 return 0;
2150}
2151
2152static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2153 struct packet_type *pt, struct net_device *orig_dev)
2154{
2155 struct sock *sk;
2156 struct packet_sock *po;
2157 struct sockaddr_ll *sll;
2158 union tpacket_uhdr h;
2159 u8 *skb_head = skb->data;
2160 int skb_len = skb->len;
2161 unsigned int snaplen, res;
2162 unsigned long status = TP_STATUS_USER;
2163 unsigned short macoff, netoff, hdrlen;
2164 struct sk_buff *copy_skb = NULL;
2165 struct timespec ts;
2166 __u32 ts_status;
2167 bool is_drop_n_account = false;
2168 bool do_vnet = false;
2169
2170 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2171 * We may add members to them until current aligned size without forcing
2172 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2173 */
2174 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2175 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2176
2177 if (skb->pkt_type == PACKET_LOOPBACK)
2178 goto drop;
2179
2180 sk = pt->af_packet_priv;
2181 po = pkt_sk(sk);
2182
2183 if (!net_eq(dev_net(dev), sock_net(sk)))
2184 goto drop;
2185
2186 if (dev->header_ops) {
2187 if (sk->sk_type != SOCK_DGRAM)
2188 skb_push(skb, skb->data - skb_mac_header(skb));
2189 else if (skb->pkt_type == PACKET_OUTGOING) {
2190 /* Special case: outgoing packets have ll header at head */
2191 skb_pull(skb, skb_network_offset(skb));
2192 }
2193 }
2194
2195 snaplen = skb->len;
2196
2197 res = run_filter(skb, sk, snaplen);
2198 if (!res)
2199 goto drop_n_restore;
2200
2201 /* If we are flooded, just give up */
2202 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2203 atomic_inc(&po->tp_drops);
2204 goto drop_n_restore;
2205 }
2206
2207 if (skb->ip_summed == CHECKSUM_PARTIAL)
2208 status |= TP_STATUS_CSUMNOTREADY;
2209 else if (skb->pkt_type != PACKET_OUTGOING &&
2210 (skb->ip_summed == CHECKSUM_COMPLETE ||
2211 skb_csum_unnecessary(skb)))
2212 status |= TP_STATUS_CSUM_VALID;
2213
2214 if (snaplen > res)
2215 snaplen = res;
2216
2217 if (sk->sk_type == SOCK_DGRAM) {
2218 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2219 po->tp_reserve;
2220 } else {
2221 unsigned int maclen = skb_network_offset(skb);
2222 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2223 (maclen < 16 ? 16 : maclen)) +
2224 po->tp_reserve;
2225 if (po->has_vnet_hdr) {
2226 netoff += sizeof(struct virtio_net_hdr);
2227 do_vnet = true;
2228 }
2229 macoff = netoff - maclen;
2230 }
2231 if (po->tp_version <= TPACKET_V2) {
2232 if (macoff + snaplen > po->rx_ring.frame_size) {
2233 if (po->copy_thresh &&
2234 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2235 if (skb_shared(skb)) {
2236 copy_skb = skb_clone(skb, GFP_ATOMIC);
2237 } else {
2238 copy_skb = skb_get(skb);
2239 skb_head = skb->data;
2240 }
2241 if (copy_skb)
2242 skb_set_owner_r(copy_skb, sk);
2243 }
2244 snaplen = po->rx_ring.frame_size - macoff;
2245 if ((int)snaplen < 0) {
2246 snaplen = 0;
2247 do_vnet = false;
2248 }
2249 }
2250 } else if (unlikely(macoff + snaplen >
2251 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2252 u32 nval;
2253
2254 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2255 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2256 snaplen, nval, macoff);
2257 snaplen = nval;
2258 if (unlikely((int)snaplen < 0)) {
2259 snaplen = 0;
2260 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2261 do_vnet = false;
2262 }
2263 }
2264 spin_lock(&sk->sk_receive_queue.lock);
2265 h.raw = packet_current_rx_frame(po, skb,
2266 TP_STATUS_KERNEL, (macoff+snaplen));
2267 if (!h.raw)
2268 goto drop_n_account;
2269 if (po->tp_version <= TPACKET_V2) {
2270 packet_increment_rx_head(po, &po->rx_ring);
2271 /*
2272 * LOSING will be reported till you read the stats,
2273 * because it's COR - Clear On Read.
2274 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2275 * at packet level.
2276 */
2277 if (atomic_read(&po->tp_drops))
2278 status |= TP_STATUS_LOSING;
2279 }
2280
2281 if (do_vnet &&
2282 virtio_net_hdr_from_skb(skb, h.raw + macoff -
2283 sizeof(struct virtio_net_hdr),
2284 vio_le(), true, 0))
2285 goto drop_n_account;
2286
2287 po->stats.stats1.tp_packets++;
2288 if (copy_skb) {
2289 status |= TP_STATUS_COPY;
2290 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2291 }
2292 spin_unlock(&sk->sk_receive_queue.lock);
2293
2294 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2295
2296 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2297 getnstimeofday(&ts);
2298
2299 status |= ts_status;
2300
2301 switch (po->tp_version) {
2302 case TPACKET_V1:
2303 h.h1->tp_len = skb->len;
2304 h.h1->tp_snaplen = snaplen;
2305 h.h1->tp_mac = macoff;
2306 h.h1->tp_net = netoff;
2307 h.h1->tp_sec = ts.tv_sec;
2308 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2309 hdrlen = sizeof(*h.h1);
2310 break;
2311 case TPACKET_V2:
2312 h.h2->tp_len = skb->len;
2313 h.h2->tp_snaplen = snaplen;
2314 h.h2->tp_mac = macoff;
2315 h.h2->tp_net = netoff;
2316 h.h2->tp_sec = ts.tv_sec;
2317 h.h2->tp_nsec = ts.tv_nsec;
2318 if (skb_vlan_tag_present(skb)) {
2319 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2320 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2321 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2322 } else {
2323 h.h2->tp_vlan_tci = 0;
2324 h.h2->tp_vlan_tpid = 0;
2325 }
2326 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2327 hdrlen = sizeof(*h.h2);
2328 break;
2329 case TPACKET_V3:
2330 /* tp_nxt_offset,vlan are already populated above.
2331 * So DONT clear those fields here
2332 */
2333 h.h3->tp_status |= status;
2334 h.h3->tp_len = skb->len;
2335 h.h3->tp_snaplen = snaplen;
2336 h.h3->tp_mac = macoff;
2337 h.h3->tp_net = netoff;
2338 h.h3->tp_sec = ts.tv_sec;
2339 h.h3->tp_nsec = ts.tv_nsec;
2340 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2341 hdrlen = sizeof(*h.h3);
2342 break;
2343 default:
2344 BUG();
2345 }
2346
2347 sll = h.raw + TPACKET_ALIGN(hdrlen);
2348 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2349 sll->sll_family = AF_PACKET;
2350 sll->sll_hatype = dev->type;
2351 sll->sll_protocol = skb->protocol;
2352 sll->sll_pkttype = skb->pkt_type;
2353 if (unlikely(po->origdev))
2354 sll->sll_ifindex = orig_dev->ifindex;
2355 else
2356 sll->sll_ifindex = dev->ifindex;
2357
2358 smp_mb();
2359
2360#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2361 if (po->tp_version <= TPACKET_V2) {
2362 u8 *start, *end;
2363
2364 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2365 macoff + snaplen);
2366
2367 for (start = h.raw; start < end; start += PAGE_SIZE)
2368 flush_dcache_page(pgv_to_page(start));
2369 }
2370 smp_wmb();
2371#endif
2372
2373 if (po->tp_version <= TPACKET_V2) {
2374 __packet_set_status(po, h.raw, status);
2375 sk->sk_data_ready(sk);
2376 } else {
2377 prb_clear_blk_fill_status(&po->rx_ring);
2378 }
2379
2380drop_n_restore:
2381 if (skb_head != skb->data && skb_shared(skb)) {
2382 skb->data = skb_head;
2383 skb->len = skb_len;
2384 }
2385drop:
2386 if (!is_drop_n_account)
2387 consume_skb(skb);
2388 else
2389 kfree_skb(skb);
2390 return 0;
2391
2392drop_n_account:
2393 spin_unlock(&sk->sk_receive_queue.lock);
2394 atomic_inc(&po->tp_drops);
2395 is_drop_n_account = true;
2396
2397 sk->sk_data_ready(sk);
2398 kfree_skb(copy_skb);
2399 goto drop_n_restore;
2400}
2401
2402static void tpacket_destruct_skb(struct sk_buff *skb)
2403{
2404 struct packet_sock *po = pkt_sk(skb->sk);
2405
2406 if (likely(po->tx_ring.pg_vec)) {
2407 void *ph;
2408 __u32 ts;
2409
2410 ph = skb_zcopy_get_nouarg(skb);
2411 packet_dec_pending(&po->tx_ring);
2412
2413 ts = __packet_set_timestamp(po, ph, skb);
2414 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2415
2416 if (!packet_read_pending(&po->tx_ring))
2417 complete(&po->skb_completion);
2418 }
2419
2420 sock_wfree(skb);
2421}
2422
2423static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2424{
2425 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2426 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2427 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2428 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2429 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2430 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2431 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2432
2433 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2434 return -EINVAL;
2435
2436 return 0;
2437}
2438
2439static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2440 struct virtio_net_hdr *vnet_hdr)
2441{
2442 if (*len < sizeof(*vnet_hdr))
2443 return -EINVAL;
2444 *len -= sizeof(*vnet_hdr);
2445
2446 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2447 return -EFAULT;
2448
2449 return __packet_snd_vnet_parse(vnet_hdr, *len);
2450}
2451
2452static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2453 void *frame, struct net_device *dev, void *data, int tp_len,
2454 __be16 proto, unsigned char *addr, int hlen, int copylen,
2455 const struct sockcm_cookie *sockc)
2456{
2457 union tpacket_uhdr ph;
2458 int to_write, offset, len, nr_frags, len_max;
2459 struct socket *sock = po->sk.sk_socket;
2460 struct page *page;
2461 int err;
2462
2463 ph.raw = frame;
2464
2465 skb->protocol = proto;
2466 skb->dev = dev;
2467 skb->priority = po->sk.sk_priority;
2468 skb->mark = po->sk.sk_mark;
2469 skb->tstamp = sockc->transmit_time;
2470 skb_setup_tx_timestamp(skb, sockc->tsflags);
2471 skb_zcopy_set_nouarg(skb, ph.raw);
2472
2473 skb_reserve(skb, hlen);
2474 skb_reset_network_header(skb);
2475
2476 to_write = tp_len;
2477
2478 if (sock->type == SOCK_DGRAM) {
2479 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2480 NULL, tp_len);
2481 if (unlikely(err < 0))
2482 return -EINVAL;
2483 } else if (copylen) {
2484 int hdrlen = min_t(int, copylen, tp_len);
2485
2486 skb_push(skb, dev->hard_header_len);
2487 skb_put(skb, copylen - dev->hard_header_len);
2488 err = skb_store_bits(skb, 0, data, hdrlen);
2489 if (unlikely(err))
2490 return err;
2491 if (!dev_validate_header(dev, skb->data, hdrlen))
2492 return -EINVAL;
2493
2494 data += hdrlen;
2495 to_write -= hdrlen;
2496 }
2497
2498 offset = offset_in_page(data);
2499 len_max = PAGE_SIZE - offset;
2500 len = ((to_write > len_max) ? len_max : to_write);
2501
2502 skb->data_len = to_write;
2503 skb->len += to_write;
2504 skb->truesize += to_write;
2505 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2506
2507 while (likely(to_write)) {
2508 nr_frags = skb_shinfo(skb)->nr_frags;
2509
2510 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2511 pr_err("Packet exceed the number of skb frags(%lu)\n",
2512 MAX_SKB_FRAGS);
2513 return -EFAULT;
2514 }
2515
2516 page = pgv_to_page(data);
2517 data += len;
2518 flush_dcache_page(page);
2519 get_page(page);
2520 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2521 to_write -= len;
2522 offset = 0;
2523 len_max = PAGE_SIZE;
2524 len = ((to_write > len_max) ? len_max : to_write);
2525 }
2526
2527 packet_parse_headers(skb, sock);
2528
2529 return tp_len;
2530}
2531
2532static int tpacket_parse_header(struct packet_sock *po, void *frame,
2533 int size_max, void **data)
2534{
2535 union tpacket_uhdr ph;
2536 int tp_len, off;
2537
2538 ph.raw = frame;
2539
2540 switch (po->tp_version) {
2541 case TPACKET_V3:
2542 if (ph.h3->tp_next_offset != 0) {
2543 pr_warn_once("variable sized slot not supported");
2544 return -EINVAL;
2545 }
2546 tp_len = ph.h3->tp_len;
2547 break;
2548 case TPACKET_V2:
2549 tp_len = ph.h2->tp_len;
2550 break;
2551 default:
2552 tp_len = ph.h1->tp_len;
2553 break;
2554 }
2555 if (unlikely(tp_len > size_max)) {
2556 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2557 return -EMSGSIZE;
2558 }
2559
2560 if (unlikely(po->tp_tx_has_off)) {
2561 int off_min, off_max;
2562
2563 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2564 off_max = po->tx_ring.frame_size - tp_len;
2565 if (po->sk.sk_type == SOCK_DGRAM) {
2566 switch (po->tp_version) {
2567 case TPACKET_V3:
2568 off = ph.h3->tp_net;
2569 break;
2570 case TPACKET_V2:
2571 off = ph.h2->tp_net;
2572 break;
2573 default:
2574 off = ph.h1->tp_net;
2575 break;
2576 }
2577 } else {
2578 switch (po->tp_version) {
2579 case TPACKET_V3:
2580 off = ph.h3->tp_mac;
2581 break;
2582 case TPACKET_V2:
2583 off = ph.h2->tp_mac;
2584 break;
2585 default:
2586 off = ph.h1->tp_mac;
2587 break;
2588 }
2589 }
2590 if (unlikely((off < off_min) || (off_max < off)))
2591 return -EINVAL;
2592 } else {
2593 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2594 }
2595
2596 *data = frame + off;
2597 return tp_len;
2598}
2599
2600static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2601{
2602 struct sk_buff *skb = NULL;
2603 struct net_device *dev;
2604 struct virtio_net_hdr *vnet_hdr = NULL;
2605 struct sockcm_cookie sockc;
2606 __be16 proto;
2607 int err, reserve = 0;
2608 void *ph;
2609 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2610 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2611 unsigned char *addr = NULL;
2612 int tp_len, size_max;
2613 void *data;
2614 int len_sum = 0;
2615 int status = TP_STATUS_AVAILABLE;
2616 int hlen, tlen, copylen = 0;
2617 long timeo = 0;
2618
2619 mutex_lock(&po->pg_vec_lock);
2620
2621 /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2622 * we need to confirm it under protection of pg_vec_lock.
2623 */
2624 if (unlikely(!po->tx_ring.pg_vec)) {
2625 err = -EBUSY;
2626 goto out;
2627 }
2628 if (likely(saddr == NULL)) {
2629 dev = packet_cached_dev_get(po);
2630 proto = po->num;
2631 } else {
2632 err = -EINVAL;
2633 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2634 goto out;
2635 if (msg->msg_namelen < (saddr->sll_halen
2636 + offsetof(struct sockaddr_ll,
2637 sll_addr)))
2638 goto out;
2639 proto = saddr->sll_protocol;
2640 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2641 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2642 if (dev && msg->msg_namelen < dev->addr_len +
2643 offsetof(struct sockaddr_ll, sll_addr))
2644 goto out_put;
2645 addr = saddr->sll_addr;
2646 }
2647 }
2648
2649 err = -ENXIO;
2650 if (unlikely(dev == NULL))
2651 goto out;
2652 err = -ENETDOWN;
2653 if (unlikely(!(dev->flags & IFF_UP)))
2654 goto out_put;
2655
2656 sockcm_init(&sockc, &po->sk);
2657 if (msg->msg_controllen) {
2658 err = sock_cmsg_send(&po->sk, msg, &sockc);
2659 if (unlikely(err))
2660 goto out_put;
2661 }
2662
2663 if (po->sk.sk_socket->type == SOCK_RAW)
2664 reserve = dev->hard_header_len;
2665 size_max = po->tx_ring.frame_size
2666 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2667
2668 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2669 size_max = dev->mtu + reserve + VLAN_HLEN;
2670
2671 reinit_completion(&po->skb_completion);
2672
2673 do {
2674 ph = packet_current_frame(po, &po->tx_ring,
2675 TP_STATUS_SEND_REQUEST);
2676 if (unlikely(ph == NULL)) {
2677 if (need_wait && skb) {
2678 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2679 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2680 if (timeo <= 0) {
2681 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2682 goto out_put;
2683 }
2684 }
2685 /* check for additional frames */
2686 continue;
2687 }
2688
2689 skb = NULL;
2690 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2691 if (tp_len < 0)
2692 goto tpacket_error;
2693
2694 status = TP_STATUS_SEND_REQUEST;
2695 hlen = LL_RESERVED_SPACE(dev);
2696 tlen = dev->needed_tailroom;
2697 if (po->has_vnet_hdr) {
2698 vnet_hdr = data;
2699 data += sizeof(*vnet_hdr);
2700 tp_len -= sizeof(*vnet_hdr);
2701 if (tp_len < 0 ||
2702 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2703 tp_len = -EINVAL;
2704 goto tpacket_error;
2705 }
2706 copylen = __virtio16_to_cpu(vio_le(),
2707 vnet_hdr->hdr_len);
2708 }
2709 copylen = max_t(int, copylen, dev->hard_header_len);
2710 skb = sock_alloc_send_skb(&po->sk,
2711 hlen + tlen + sizeof(struct sockaddr_ll) +
2712 (copylen - dev->hard_header_len),
2713 !need_wait, &err);
2714
2715 if (unlikely(skb == NULL)) {
2716 /* we assume the socket was initially writeable ... */
2717 if (likely(len_sum > 0))
2718 err = len_sum;
2719 goto out_status;
2720 }
2721 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2722 addr, hlen, copylen, &sockc);
2723 if (likely(tp_len >= 0) &&
2724 tp_len > dev->mtu + reserve &&
2725 !po->has_vnet_hdr &&
2726 !packet_extra_vlan_len_allowed(dev, skb))
2727 tp_len = -EMSGSIZE;
2728
2729 if (unlikely(tp_len < 0)) {
2730tpacket_error:
2731 if (po->tp_loss) {
2732 __packet_set_status(po, ph,
2733 TP_STATUS_AVAILABLE);
2734 packet_increment_head(&po->tx_ring);
2735 kfree_skb(skb);
2736 continue;
2737 } else {
2738 status = TP_STATUS_WRONG_FORMAT;
2739 err = tp_len;
2740 goto out_status;
2741 }
2742 }
2743
2744 if (po->has_vnet_hdr) {
2745 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2746 tp_len = -EINVAL;
2747 goto tpacket_error;
2748 }
2749 virtio_net_hdr_set_proto(skb, vnet_hdr);
2750 }
2751
2752 skb->destructor = tpacket_destruct_skb;
2753 __packet_set_status(po, ph, TP_STATUS_SENDING);
2754 packet_inc_pending(&po->tx_ring);
2755
2756 status = TP_STATUS_SEND_REQUEST;
2757 err = po->xmit(skb);
2758 if (unlikely(err > 0)) {
2759 err = net_xmit_errno(err);
2760 if (err && __packet_get_status(po, ph) ==
2761 TP_STATUS_AVAILABLE) {
2762 /* skb was destructed already */
2763 skb = NULL;
2764 goto out_status;
2765 }
2766 /*
2767 * skb was dropped but not destructed yet;
2768 * let's treat it like congestion or err < 0
2769 */
2770 err = 0;
2771 }
2772 packet_increment_head(&po->tx_ring);
2773 len_sum += tp_len;
2774 } while (likely((ph != NULL) ||
2775 /* Note: packet_read_pending() might be slow if we have
2776 * to call it as it's per_cpu variable, but in fast-path
2777 * we already short-circuit the loop with the first
2778 * condition, and luckily don't have to go that path
2779 * anyway.
2780 */
2781 (need_wait && packet_read_pending(&po->tx_ring))));
2782
2783 err = len_sum;
2784 goto out_put;
2785
2786out_status:
2787 __packet_set_status(po, ph, status);
2788 kfree_skb(skb);
2789out_put:
2790 dev_put(dev);
2791out:
2792 mutex_unlock(&po->pg_vec_lock);
2793 return err;
2794}
2795
2796static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2797 size_t reserve, size_t len,
2798 size_t linear, int noblock,
2799 int *err)
2800{
2801 struct sk_buff *skb;
2802
2803 /* Under a page? Don't bother with paged skb. */
2804 if (prepad + len < PAGE_SIZE || !linear)
2805 linear = len;
2806
2807 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2808 err, 0);
2809 if (!skb)
2810 return NULL;
2811
2812 skb_reserve(skb, reserve);
2813 skb_put(skb, linear);
2814 skb->data_len = len - linear;
2815 skb->len += len - linear;
2816
2817 return skb;
2818}
2819
2820static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2821{
2822 struct sock *sk = sock->sk;
2823 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2824 struct sk_buff *skb;
2825 struct net_device *dev;
2826 __be16 proto;
2827 unsigned char *addr = NULL;
2828 int err, reserve = 0;
2829 struct sockcm_cookie sockc;
2830 struct virtio_net_hdr vnet_hdr = { 0 };
2831 int offset = 0;
2832 struct packet_sock *po = pkt_sk(sk);
2833 bool has_vnet_hdr = false;
2834 int hlen, tlen, linear;
2835 int extra_len = 0;
2836
2837 /*
2838 * Get and verify the address.
2839 */
2840
2841 if (likely(saddr == NULL)) {
2842 dev = packet_cached_dev_get(po);
2843 proto = po->num;
2844 } else {
2845 err = -EINVAL;
2846 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2847 goto out;
2848 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2849 goto out;
2850 proto = saddr->sll_protocol;
2851 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2852 if (sock->type == SOCK_DGRAM) {
2853 if (dev && msg->msg_namelen < dev->addr_len +
2854 offsetof(struct sockaddr_ll, sll_addr))
2855 goto out_unlock;
2856 addr = saddr->sll_addr;
2857 }
2858 }
2859
2860 err = -ENXIO;
2861 if (unlikely(dev == NULL))
2862 goto out_unlock;
2863 err = -ENETDOWN;
2864 if (unlikely(!(dev->flags & IFF_UP)))
2865 goto out_unlock;
2866
2867 sockcm_init(&sockc, sk);
2868 sockc.mark = sk->sk_mark;
2869 if (msg->msg_controllen) {
2870 err = sock_cmsg_send(sk, msg, &sockc);
2871 if (unlikely(err))
2872 goto out_unlock;
2873 }
2874
2875 if (sock->type == SOCK_RAW)
2876 reserve = dev->hard_header_len;
2877 if (po->has_vnet_hdr) {
2878 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2879 if (err)
2880 goto out_unlock;
2881 has_vnet_hdr = true;
2882 }
2883
2884 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2885 if (!netif_supports_nofcs(dev)) {
2886 err = -EPROTONOSUPPORT;
2887 goto out_unlock;
2888 }
2889 extra_len = 4; /* We're doing our own CRC */
2890 }
2891
2892 err = -EMSGSIZE;
2893 if (!vnet_hdr.gso_type &&
2894 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2895 goto out_unlock;
2896
2897 err = -ENOBUFS;
2898 hlen = LL_RESERVED_SPACE(dev);
2899 tlen = dev->needed_tailroom;
2900 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2901 linear = max(linear, min_t(int, len, dev->hard_header_len));
2902 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2903 msg->msg_flags & MSG_DONTWAIT, &err);
2904 if (skb == NULL)
2905 goto out_unlock;
2906
2907 skb_reset_network_header(skb);
2908
2909 err = -EINVAL;
2910 if (sock->type == SOCK_DGRAM) {
2911 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2912 if (unlikely(offset < 0))
2913 goto out_free;
2914 } else if (reserve) {
2915 skb_reserve(skb, -reserve);
2916 if (len < reserve + sizeof(struct ipv6hdr) &&
2917 dev->min_header_len != dev->hard_header_len)
2918 skb_reset_network_header(skb);
2919 }
2920
2921 /* Returns -EFAULT on error */
2922 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2923 if (err)
2924 goto out_free;
2925
2926 if (sock->type == SOCK_RAW &&
2927 !dev_validate_header(dev, skb->data, len)) {
2928 err = -EINVAL;
2929 goto out_free;
2930 }
2931
2932 skb_setup_tx_timestamp(skb, sockc.tsflags);
2933
2934 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2935 !packet_extra_vlan_len_allowed(dev, skb)) {
2936 err = -EMSGSIZE;
2937 goto out_free;
2938 }
2939
2940 skb->protocol = proto;
2941 skb->dev = dev;
2942 skb->priority = sk->sk_priority;
2943 skb->mark = sockc.mark;
2944 skb->tstamp = sockc.transmit_time;
2945
2946 if (has_vnet_hdr) {
2947 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2948 if (err)
2949 goto out_free;
2950 len += sizeof(vnet_hdr);
2951 virtio_net_hdr_set_proto(skb, &vnet_hdr);
2952 }
2953
2954 packet_parse_headers(skb, sock);
2955
2956 if (unlikely(extra_len == 4))
2957 skb->no_fcs = 1;
2958
2959 err = po->xmit(skb);
2960 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2961 goto out_unlock;
2962
2963 dev_put(dev);
2964
2965 return len;
2966
2967out_free:
2968 kfree_skb(skb);
2969out_unlock:
2970 if (dev)
2971 dev_put(dev);
2972out:
2973 return err;
2974}
2975
2976static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2977{
2978 struct sock *sk = sock->sk;
2979 struct packet_sock *po = pkt_sk(sk);
2980
2981 if (po->tx_ring.pg_vec)
2982 return tpacket_snd(po, msg);
2983 else
2984 return packet_snd(sock, msg, len);
2985}
2986
2987/*
2988 * Close a PACKET socket. This is fairly simple. We immediately go
2989 * to 'closed' state and remove our protocol entry in the device list.
2990 */
2991
2992static int packet_release(struct socket *sock)
2993{
2994 struct sock *sk = sock->sk;
2995 struct packet_sock *po;
2996 struct packet_fanout *f;
2997 struct net *net;
2998 union tpacket_req_u req_u;
2999
3000 if (!sk)
3001 return 0;
3002
3003 net = sock_net(sk);
3004 po = pkt_sk(sk);
3005
3006 mutex_lock(&net->packet.sklist_lock);
3007 sk_del_node_init_rcu(sk);
3008 mutex_unlock(&net->packet.sklist_lock);
3009
3010 preempt_disable();
3011 sock_prot_inuse_add(net, sk->sk_prot, -1);
3012 preempt_enable();
3013
3014 spin_lock(&po->bind_lock);
3015 unregister_prot_hook(sk, false);
3016 packet_cached_dev_reset(po);
3017
3018 if (po->prot_hook.dev) {
3019 dev_put(po->prot_hook.dev);
3020 po->prot_hook.dev = NULL;
3021 }
3022 spin_unlock(&po->bind_lock);
3023
3024 packet_flush_mclist(sk);
3025
3026 lock_sock(sk);
3027 if (po->rx_ring.pg_vec) {
3028 memset(&req_u, 0, sizeof(req_u));
3029 packet_set_ring(sk, &req_u, 1, 0);
3030 }
3031
3032 if (po->tx_ring.pg_vec) {
3033 memset(&req_u, 0, sizeof(req_u));
3034 packet_set_ring(sk, &req_u, 1, 1);
3035 }
3036 release_sock(sk);
3037
3038 f = fanout_release(sk);
3039
3040 synchronize_net();
3041
3042 kfree(po->rollover);
3043 if (f) {
3044 fanout_release_data(f);
3045 kfree(f);
3046 }
3047 /*
3048 * Now the socket is dead. No more input will appear.
3049 */
3050 sock_orphan(sk);
3051 sock->sk = NULL;
3052
3053 /* Purge queues */
3054
3055 skb_queue_purge(&sk->sk_receive_queue);
3056 packet_free_pending(po);
3057 sk_refcnt_debug_release(sk);
3058
3059 sock_put(sk);
3060 return 0;
3061}
3062
3063/*
3064 * Attach a packet hook.
3065 */
3066
3067static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3068 __be16 proto)
3069{
3070 struct packet_sock *po = pkt_sk(sk);
3071 struct net_device *dev_curr;
3072 __be16 proto_curr;
3073 bool need_rehook;
3074 struct net_device *dev = NULL;
3075 int ret = 0;
3076 bool unlisted = false;
3077
3078 lock_sock(sk);
3079 spin_lock(&po->bind_lock);
3080 rcu_read_lock();
3081
3082 if (po->fanout) {
3083 ret = -EINVAL;
3084 goto out_unlock;
3085 }
3086
3087 if (name) {
3088 dev = dev_get_by_name_rcu(sock_net(sk), name);
3089 if (!dev) {
3090 ret = -ENODEV;
3091 goto out_unlock;
3092 }
3093 } else if (ifindex) {
3094 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3095 if (!dev) {
3096 ret = -ENODEV;
3097 goto out_unlock;
3098 }
3099 }
3100
3101 if (dev)
3102 dev_hold(dev);
3103
3104 proto_curr = po->prot_hook.type;
3105 dev_curr = po->prot_hook.dev;
3106
3107 need_rehook = proto_curr != proto || dev_curr != dev;
3108
3109 if (need_rehook) {
3110 if (po->running) {
3111 rcu_read_unlock();
3112 /* prevents packet_notifier() from calling
3113 * register_prot_hook()
3114 */
3115 po->num = 0;
3116 __unregister_prot_hook(sk, true);
3117 rcu_read_lock();
3118 dev_curr = po->prot_hook.dev;
3119 if (dev)
3120 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3121 dev->ifindex);
3122 }
3123
3124 BUG_ON(po->running);
3125 po->num = proto;
3126 po->prot_hook.type = proto;
3127
3128 if (unlikely(unlisted)) {
3129 dev_put(dev);
3130 po->prot_hook.dev = NULL;
3131 po->ifindex = -1;
3132 packet_cached_dev_reset(po);
3133 } else {
3134 po->prot_hook.dev = dev;
3135 po->ifindex = dev ? dev->ifindex : 0;
3136 packet_cached_dev_assign(po, dev);
3137 }
3138 }
3139 if (dev_curr)
3140 dev_put(dev_curr);
3141
3142 if (proto == 0 || !need_rehook)
3143 goto out_unlock;
3144
3145 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3146 register_prot_hook(sk);
3147 } else {
3148 sk->sk_err = ENETDOWN;
3149 if (!sock_flag(sk, SOCK_DEAD))
3150 sk->sk_error_report(sk);
3151 }
3152
3153out_unlock:
3154 rcu_read_unlock();
3155 spin_unlock(&po->bind_lock);
3156 release_sock(sk);
3157 return ret;
3158}
3159
3160/*
3161 * Bind a packet socket to a device
3162 */
3163
3164static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3165 int addr_len)
3166{
3167 struct sock *sk = sock->sk;
3168 char name[sizeof(uaddr->sa_data) + 1];
3169
3170 /*
3171 * Check legality
3172 */
3173
3174 if (addr_len != sizeof(struct sockaddr))
3175 return -EINVAL;
3176 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3177 * zero-terminated.
3178 */
3179 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3180 name[sizeof(uaddr->sa_data)] = 0;
3181
3182 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3183}
3184
3185static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3186{
3187 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3188 struct sock *sk = sock->sk;
3189
3190 /*
3191 * Check legality
3192 */
3193
3194 if (addr_len < sizeof(struct sockaddr_ll))
3195 return -EINVAL;
3196 if (sll->sll_family != AF_PACKET)
3197 return -EINVAL;
3198
3199 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3200 sll->sll_protocol ? : pkt_sk(sk)->num);
3201}
3202
3203static struct proto packet_proto = {
3204 .name = "PACKET",
3205 .owner = THIS_MODULE,
3206 .obj_size = sizeof(struct packet_sock),
3207};
3208
3209/*
3210 * Create a packet of type SOCK_PACKET.
3211 */
3212
3213static int packet_create(struct net *net, struct socket *sock, int protocol,
3214 int kern)
3215{
3216 struct sock *sk;
3217 struct packet_sock *po;
3218 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3219 int err;
3220
3221 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3222 return -EPERM;
3223 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3224 sock->type != SOCK_PACKET)
3225 return -ESOCKTNOSUPPORT;
3226
3227 sock->state = SS_UNCONNECTED;
3228
3229 err = -ENOBUFS;
3230 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3231 if (sk == NULL)
3232 goto out;
3233
3234 sock->ops = &packet_ops;
3235 if (sock->type == SOCK_PACKET)
3236 sock->ops = &packet_ops_spkt;
3237
3238 sock_init_data(sock, sk);
3239
3240 po = pkt_sk(sk);
3241 init_completion(&po->skb_completion);
3242 sk->sk_family = PF_PACKET;
3243 po->num = proto;
3244 po->xmit = dev_queue_xmit;
3245
3246 err = packet_alloc_pending(po);
3247 if (err)
3248 goto out2;
3249
3250 packet_cached_dev_reset(po);
3251
3252 sk->sk_destruct = packet_sock_destruct;
3253 sk_refcnt_debug_inc(sk);
3254
3255 /*
3256 * Attach a protocol block
3257 */
3258
3259 spin_lock_init(&po->bind_lock);
3260 mutex_init(&po->pg_vec_lock);
3261 po->rollover = NULL;
3262 po->prot_hook.func = packet_rcv;
3263
3264 if (sock->type == SOCK_PACKET)
3265 po->prot_hook.func = packet_rcv_spkt;
3266
3267 po->prot_hook.af_packet_priv = sk;
3268
3269 if (proto) {
3270 po->prot_hook.type = proto;
3271 __register_prot_hook(sk);
3272 }
3273
3274 mutex_lock(&net->packet.sklist_lock);
3275 sk_add_node_tail_rcu(sk, &net->packet.sklist);
3276 mutex_unlock(&net->packet.sklist_lock);
3277
3278 preempt_disable();
3279 sock_prot_inuse_add(net, &packet_proto, 1);
3280 preempt_enable();
3281
3282 return 0;
3283out2:
3284 sk_free(sk);
3285out:
3286 return err;
3287}
3288
3289/*
3290 * Pull a packet from our receive queue and hand it to the user.
3291 * If necessary we block.
3292 */
3293
3294static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3295 int flags)
3296{
3297 struct sock *sk = sock->sk;
3298 struct sk_buff *skb;
3299 int copied, err;
3300 int vnet_hdr_len = 0;
3301 unsigned int origlen = 0;
3302
3303 err = -EINVAL;
3304 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3305 goto out;
3306
3307#if 0
3308 /* What error should we return now? EUNATTACH? */
3309 if (pkt_sk(sk)->ifindex < 0)
3310 return -ENODEV;
3311#endif
3312
3313 if (flags & MSG_ERRQUEUE) {
3314 err = sock_recv_errqueue(sk, msg, len,
3315 SOL_PACKET, PACKET_TX_TIMESTAMP);
3316 goto out;
3317 }
3318
3319 /*
3320 * Call the generic datagram receiver. This handles all sorts
3321 * of horrible races and re-entrancy so we can forget about it
3322 * in the protocol layers.
3323 *
3324 * Now it will return ENETDOWN, if device have just gone down,
3325 * but then it will block.
3326 */
3327
3328 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3329
3330 /*
3331 * An error occurred so return it. Because skb_recv_datagram()
3332 * handles the blocking we don't see and worry about blocking
3333 * retries.
3334 */
3335
3336 if (skb == NULL)
3337 goto out;
3338
3339 packet_rcv_try_clear_pressure(pkt_sk(sk));
3340
3341 if (pkt_sk(sk)->has_vnet_hdr) {
3342 err = packet_rcv_vnet(msg, skb, &len);
3343 if (err)
3344 goto out_free;
3345 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3346 }
3347
3348 /* You lose any data beyond the buffer you gave. If it worries
3349 * a user program they can ask the device for its MTU
3350 * anyway.
3351 */
3352 copied = skb->len;
3353 if (copied > len) {
3354 copied = len;
3355 msg->msg_flags |= MSG_TRUNC;
3356 }
3357
3358 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3359 if (err)
3360 goto out_free;
3361
3362 if (sock->type != SOCK_PACKET) {
3363 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3364
3365 /* Original length was stored in sockaddr_ll fields */
3366 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3367 sll->sll_family = AF_PACKET;
3368 sll->sll_protocol = skb->protocol;
3369 }
3370
3371 sock_recv_ts_and_drops(msg, sk, skb);
3372
3373 if (msg->msg_name) {
3374 int copy_len;
3375
3376 /* If the address length field is there to be filled
3377 * in, we fill it in now.
3378 */
3379 if (sock->type == SOCK_PACKET) {
3380 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3381 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3382 copy_len = msg->msg_namelen;
3383 } else {
3384 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3385
3386 msg->msg_namelen = sll->sll_halen +
3387 offsetof(struct sockaddr_ll, sll_addr);
3388 copy_len = msg->msg_namelen;
3389 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3390 memset(msg->msg_name +
3391 offsetof(struct sockaddr_ll, sll_addr),
3392 0, sizeof(sll->sll_addr));
3393 msg->msg_namelen = sizeof(struct sockaddr_ll);
3394 }
3395 }
3396 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3397 }
3398
3399 if (pkt_sk(sk)->auxdata) {
3400 struct tpacket_auxdata aux;
3401
3402 aux.tp_status = TP_STATUS_USER;
3403 if (skb->ip_summed == CHECKSUM_PARTIAL)
3404 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3405 else if (skb->pkt_type != PACKET_OUTGOING &&
3406 (skb->ip_summed == CHECKSUM_COMPLETE ||
3407 skb_csum_unnecessary(skb)))
3408 aux.tp_status |= TP_STATUS_CSUM_VALID;
3409
3410 aux.tp_len = origlen;
3411 aux.tp_snaplen = skb->len;
3412 aux.tp_mac = 0;
3413 aux.tp_net = skb_network_offset(skb);
3414 if (skb_vlan_tag_present(skb)) {
3415 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3416 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3417 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3418 } else {
3419 aux.tp_vlan_tci = 0;
3420 aux.tp_vlan_tpid = 0;
3421 }
3422 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3423 }
3424
3425 /*
3426 * Free or return the buffer as appropriate. Again this
3427 * hides all the races and re-entrancy issues from us.
3428 */
3429 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3430
3431out_free:
3432 skb_free_datagram(sk, skb);
3433out:
3434 return err;
3435}
3436
3437static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3438 int peer)
3439{
3440 struct net_device *dev;
3441 struct sock *sk = sock->sk;
3442
3443 if (peer)
3444 return -EOPNOTSUPP;
3445
3446 uaddr->sa_family = AF_PACKET;
3447 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3448 rcu_read_lock();
3449 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3450 if (dev)
3451 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3452 rcu_read_unlock();
3453
3454 return sizeof(*uaddr);
3455}
3456
3457static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3458 int peer)
3459{
3460 struct net_device *dev;
3461 struct sock *sk = sock->sk;
3462 struct packet_sock *po = pkt_sk(sk);
3463 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3464
3465 if (peer)
3466 return -EOPNOTSUPP;
3467
3468 sll->sll_family = AF_PACKET;
3469 sll->sll_ifindex = po->ifindex;
3470 sll->sll_protocol = po->num;
3471 sll->sll_pkttype = 0;
3472 rcu_read_lock();
3473 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3474 if (dev) {
3475 sll->sll_hatype = dev->type;
3476 sll->sll_halen = dev->addr_len;
3477 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3478 } else {
3479 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3480 sll->sll_halen = 0;
3481 }
3482 rcu_read_unlock();
3483
3484 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3485}
3486
3487static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3488 int what)
3489{
3490 switch (i->type) {
3491 case PACKET_MR_MULTICAST:
3492 if (i->alen != dev->addr_len)
3493 return -EINVAL;
3494 if (what > 0)
3495 return dev_mc_add(dev, i->addr);
3496 else
3497 return dev_mc_del(dev, i->addr);
3498 break;
3499 case PACKET_MR_PROMISC:
3500 return dev_set_promiscuity(dev, what);
3501 case PACKET_MR_ALLMULTI:
3502 return dev_set_allmulti(dev, what);
3503 case PACKET_MR_UNICAST:
3504 if (i->alen != dev->addr_len)
3505 return -EINVAL;
3506 if (what > 0)
3507 return dev_uc_add(dev, i->addr);
3508 else
3509 return dev_uc_del(dev, i->addr);
3510 break;
3511 default:
3512 break;
3513 }
3514 return 0;
3515}
3516
3517static void packet_dev_mclist_delete(struct net_device *dev,
3518 struct packet_mclist **mlp)
3519{
3520 struct packet_mclist *ml;
3521
3522 while ((ml = *mlp) != NULL) {
3523 if (ml->ifindex == dev->ifindex) {
3524 packet_dev_mc(dev, ml, -1);
3525 *mlp = ml->next;
3526 kfree(ml);
3527 } else
3528 mlp = &ml->next;
3529 }
3530}
3531
3532static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3533{
3534 struct packet_sock *po = pkt_sk(sk);
3535 struct packet_mclist *ml, *i;
3536 struct net_device *dev;
3537 int err;
3538
3539 rtnl_lock();
3540
3541 err = -ENODEV;
3542 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3543 if (!dev)
3544 goto done;
3545
3546 err = -EINVAL;
3547 if (mreq->mr_alen > dev->addr_len)
3548 goto done;
3549
3550 err = -ENOBUFS;
3551 i = kmalloc(sizeof(*i), GFP_KERNEL);
3552 if (i == NULL)
3553 goto done;
3554
3555 err = 0;
3556 for (ml = po->mclist; ml; ml = ml->next) {
3557 if (ml->ifindex == mreq->mr_ifindex &&
3558 ml->type == mreq->mr_type &&
3559 ml->alen == mreq->mr_alen &&
3560 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3561 ml->count++;
3562 /* Free the new element ... */
3563 kfree(i);
3564 goto done;
3565 }
3566 }
3567
3568 i->type = mreq->mr_type;
3569 i->ifindex = mreq->mr_ifindex;
3570 i->alen = mreq->mr_alen;
3571 memcpy(i->addr, mreq->mr_address, i->alen);
3572 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3573 i->count = 1;
3574 i->next = po->mclist;
3575 po->mclist = i;
3576 err = packet_dev_mc(dev, i, 1);
3577 if (err) {
3578 po->mclist = i->next;
3579 kfree(i);
3580 }
3581
3582done:
3583 rtnl_unlock();
3584 return err;
3585}
3586
3587static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3588{
3589 struct packet_mclist *ml, **mlp;
3590
3591 rtnl_lock();
3592
3593 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3594 if (ml->ifindex == mreq->mr_ifindex &&
3595 ml->type == mreq->mr_type &&
3596 ml->alen == mreq->mr_alen &&
3597 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3598 if (--ml->count == 0) {
3599 struct net_device *dev;
3600 *mlp = ml->next;
3601 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3602 if (dev)
3603 packet_dev_mc(dev, ml, -1);
3604 kfree(ml);
3605 }
3606 break;
3607 }
3608 }
3609 rtnl_unlock();
3610 return 0;
3611}
3612
3613static void packet_flush_mclist(struct sock *sk)
3614{
3615 struct packet_sock *po = pkt_sk(sk);
3616 struct packet_mclist *ml;
3617
3618 if (!po->mclist)
3619 return;
3620
3621 rtnl_lock();
3622 while ((ml = po->mclist) != NULL) {
3623 struct net_device *dev;
3624
3625 po->mclist = ml->next;
3626 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3627 if (dev != NULL)
3628 packet_dev_mc(dev, ml, -1);
3629 kfree(ml);
3630 }
3631 rtnl_unlock();
3632}
3633
3634static int
3635packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3636{
3637 struct sock *sk = sock->sk;
3638 struct packet_sock *po = pkt_sk(sk);
3639 int ret;
3640
3641 if (level != SOL_PACKET)
3642 return -ENOPROTOOPT;
3643
3644 switch (optname) {
3645 case PACKET_ADD_MEMBERSHIP:
3646 case PACKET_DROP_MEMBERSHIP:
3647 {
3648 struct packet_mreq_max mreq;
3649 int len = optlen;
3650 memset(&mreq, 0, sizeof(mreq));
3651 if (len < sizeof(struct packet_mreq))
3652 return -EINVAL;
3653 if (len > sizeof(mreq))
3654 len = sizeof(mreq);
3655 if (copy_from_user(&mreq, optval, len))
3656 return -EFAULT;
3657 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3658 return -EINVAL;
3659 if (optname == PACKET_ADD_MEMBERSHIP)
3660 ret = packet_mc_add(sk, &mreq);
3661 else
3662 ret = packet_mc_drop(sk, &mreq);
3663 return ret;
3664 }
3665
3666 case PACKET_RX_RING:
3667 case PACKET_TX_RING:
3668 {
3669 union tpacket_req_u req_u;
3670 int len;
3671
3672 lock_sock(sk);
3673 switch (po->tp_version) {
3674 case TPACKET_V1:
3675 case TPACKET_V2:
3676 len = sizeof(req_u.req);
3677 break;
3678 case TPACKET_V3:
3679 default:
3680 len = sizeof(req_u.req3);
3681 break;
3682 }
3683 if (optlen < len) {
3684 ret = -EINVAL;
3685 } else {
3686 if (copy_from_user(&req_u.req, optval, len))
3687 ret = -EFAULT;
3688 else
3689 ret = packet_set_ring(sk, &req_u, 0,
3690 optname == PACKET_TX_RING);
3691 }
3692 release_sock(sk);
3693 return ret;
3694 }
3695 case PACKET_COPY_THRESH:
3696 {
3697 int val;
3698
3699 if (optlen != sizeof(val))
3700 return -EINVAL;
3701 if (copy_from_user(&val, optval, sizeof(val)))
3702 return -EFAULT;
3703
3704 pkt_sk(sk)->copy_thresh = val;
3705 return 0;
3706 }
3707 case PACKET_VERSION:
3708 {
3709 int val;
3710
3711 if (optlen != sizeof(val))
3712 return -EINVAL;
3713 if (copy_from_user(&val, optval, sizeof(val)))
3714 return -EFAULT;
3715 switch (val) {
3716 case TPACKET_V1:
3717 case TPACKET_V2:
3718 case TPACKET_V3:
3719 break;
3720 default:
3721 return -EINVAL;
3722 }
3723 lock_sock(sk);
3724 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3725 ret = -EBUSY;
3726 } else {
3727 po->tp_version = val;
3728 ret = 0;
3729 }
3730 release_sock(sk);
3731 return ret;
3732 }
3733 case PACKET_RESERVE:
3734 {
3735 unsigned int val;
3736
3737 if (optlen != sizeof(val))
3738 return -EINVAL;
3739 if (copy_from_user(&val, optval, sizeof(val)))
3740 return -EFAULT;
3741 if (val > INT_MAX)
3742 return -EINVAL;
3743 lock_sock(sk);
3744 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3745 ret = -EBUSY;
3746 } else {
3747 po->tp_reserve = val;
3748 ret = 0;
3749 }
3750 release_sock(sk);
3751 return ret;
3752 }
3753 case PACKET_LOSS:
3754 {
3755 unsigned int val;
3756
3757 if (optlen != sizeof(val))
3758 return -EINVAL;
3759 if (copy_from_user(&val, optval, sizeof(val)))
3760 return -EFAULT;
3761
3762 lock_sock(sk);
3763 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3764 ret = -EBUSY;
3765 } else {
3766 po->tp_loss = !!val;
3767 ret = 0;
3768 }
3769 release_sock(sk);
3770 return ret;
3771 }
3772 case PACKET_AUXDATA:
3773 {
3774 int val;
3775
3776 if (optlen < sizeof(val))
3777 return -EINVAL;
3778 if (copy_from_user(&val, optval, sizeof(val)))
3779 return -EFAULT;
3780
3781 lock_sock(sk);
3782 po->auxdata = !!val;
3783 release_sock(sk);
3784 return 0;
3785 }
3786 case PACKET_ORIGDEV:
3787 {
3788 int val;
3789
3790 if (optlen < sizeof(val))
3791 return -EINVAL;
3792 if (copy_from_user(&val, optval, sizeof(val)))
3793 return -EFAULT;
3794
3795 lock_sock(sk);
3796 po->origdev = !!val;
3797 release_sock(sk);
3798 return 0;
3799 }
3800 case PACKET_VNET_HDR:
3801 {
3802 int val;
3803
3804 if (sock->type != SOCK_RAW)
3805 return -EINVAL;
3806 if (optlen < sizeof(val))
3807 return -EINVAL;
3808 if (copy_from_user(&val, optval, sizeof(val)))
3809 return -EFAULT;
3810
3811 lock_sock(sk);
3812 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3813 ret = -EBUSY;
3814 } else {
3815 po->has_vnet_hdr = !!val;
3816 ret = 0;
3817 }
3818 release_sock(sk);
3819 return ret;
3820 }
3821 case PACKET_TIMESTAMP:
3822 {
3823 int val;
3824
3825 if (optlen != sizeof(val))
3826 return -EINVAL;
3827 if (copy_from_user(&val, optval, sizeof(val)))
3828 return -EFAULT;
3829
3830 po->tp_tstamp = val;
3831 return 0;
3832 }
3833 case PACKET_FANOUT:
3834 {
3835 int val;
3836
3837 if (optlen != sizeof(val))
3838 return -EINVAL;
3839 if (copy_from_user(&val, optval, sizeof(val)))
3840 return -EFAULT;
3841
3842 return fanout_add(sk, val & 0xffff, val >> 16);
3843 }
3844 case PACKET_FANOUT_DATA:
3845 {
3846 if (!po->fanout)
3847 return -EINVAL;
3848
3849 return fanout_set_data(po, optval, optlen);
3850 }
3851 case PACKET_IGNORE_OUTGOING:
3852 {
3853 int val;
3854
3855 if (optlen != sizeof(val))
3856 return -EINVAL;
3857 if (copy_from_user(&val, optval, sizeof(val)))
3858 return -EFAULT;
3859 if (val < 0 || val > 1)
3860 return -EINVAL;
3861
3862 po->prot_hook.ignore_outgoing = !!val;
3863 return 0;
3864 }
3865 case PACKET_TX_HAS_OFF:
3866 {
3867 unsigned int val;
3868
3869 if (optlen != sizeof(val))
3870 return -EINVAL;
3871 if (copy_from_user(&val, optval, sizeof(val)))
3872 return -EFAULT;
3873
3874 lock_sock(sk);
3875 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3876 ret = -EBUSY;
3877 } else {
3878 po->tp_tx_has_off = !!val;
3879 ret = 0;
3880 }
3881 release_sock(sk);
3882 return 0;
3883 }
3884 case PACKET_QDISC_BYPASS:
3885 {
3886 int val;
3887
3888 if (optlen != sizeof(val))
3889 return -EINVAL;
3890 if (copy_from_user(&val, optval, sizeof(val)))
3891 return -EFAULT;
3892
3893 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3894 return 0;
3895 }
3896 default:
3897 return -ENOPROTOOPT;
3898 }
3899}
3900
3901static int packet_getsockopt(struct socket *sock, int level, int optname,
3902 char __user *optval, int __user *optlen)
3903{
3904 int len;
3905 int val, lv = sizeof(val);
3906 struct sock *sk = sock->sk;
3907 struct packet_sock *po = pkt_sk(sk);
3908 void *data = &val;
3909 union tpacket_stats_u st;
3910 struct tpacket_rollover_stats rstats;
3911 int drops;
3912
3913 if (level != SOL_PACKET)
3914 return -ENOPROTOOPT;
3915
3916 if (get_user(len, optlen))
3917 return -EFAULT;
3918
3919 if (len < 0)
3920 return -EINVAL;
3921
3922 switch (optname) {
3923 case PACKET_STATISTICS:
3924 spin_lock_bh(&sk->sk_receive_queue.lock);
3925 memcpy(&st, &po->stats, sizeof(st));
3926 memset(&po->stats, 0, sizeof(po->stats));
3927 spin_unlock_bh(&sk->sk_receive_queue.lock);
3928 drops = atomic_xchg(&po->tp_drops, 0);
3929
3930 if (po->tp_version == TPACKET_V3) {
3931 lv = sizeof(struct tpacket_stats_v3);
3932 st.stats3.tp_drops = drops;
3933 st.stats3.tp_packets += drops;
3934 data = &st.stats3;
3935 } else {
3936 lv = sizeof(struct tpacket_stats);
3937 st.stats1.tp_drops = drops;
3938 st.stats1.tp_packets += drops;
3939 data = &st.stats1;
3940 }
3941
3942 break;
3943 case PACKET_AUXDATA:
3944 val = po->auxdata;
3945 break;
3946 case PACKET_ORIGDEV:
3947 val = po->origdev;
3948 break;
3949 case PACKET_VNET_HDR:
3950 val = po->has_vnet_hdr;
3951 break;
3952 case PACKET_VERSION:
3953 val = po->tp_version;
3954 break;
3955 case PACKET_HDRLEN:
3956 if (len > sizeof(int))
3957 len = sizeof(int);
3958 if (len < sizeof(int))
3959 return -EINVAL;
3960 if (copy_from_user(&val, optval, len))
3961 return -EFAULT;
3962 switch (val) {
3963 case TPACKET_V1:
3964 val = sizeof(struct tpacket_hdr);
3965 break;
3966 case TPACKET_V2:
3967 val = sizeof(struct tpacket2_hdr);
3968 break;
3969 case TPACKET_V3:
3970 val = sizeof(struct tpacket3_hdr);
3971 break;
3972 default:
3973 return -EINVAL;
3974 }
3975 break;
3976 case PACKET_RESERVE:
3977 val = po->tp_reserve;
3978 break;
3979 case PACKET_LOSS:
3980 val = po->tp_loss;
3981 break;
3982 case PACKET_TIMESTAMP:
3983 val = po->tp_tstamp;
3984 break;
3985 case PACKET_FANOUT:
3986 val = (po->fanout ?
3987 ((u32)po->fanout->id |
3988 ((u32)po->fanout->type << 16) |
3989 ((u32)po->fanout->flags << 24)) :
3990 0);
3991 break;
3992 case PACKET_IGNORE_OUTGOING:
3993 val = po->prot_hook.ignore_outgoing;
3994 break;
3995 case PACKET_ROLLOVER_STATS:
3996 if (!po->rollover)
3997 return -EINVAL;
3998 rstats.tp_all = atomic_long_read(&po->rollover->num);
3999 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4000 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4001 data = &rstats;
4002 lv = sizeof(rstats);
4003 break;
4004 case PACKET_TX_HAS_OFF:
4005 val = po->tp_tx_has_off;
4006 break;
4007 case PACKET_QDISC_BYPASS:
4008 val = packet_use_direct_xmit(po);
4009 break;
4010 default:
4011 return -ENOPROTOOPT;
4012 }
4013
4014 if (len > lv)
4015 len = lv;
4016 if (put_user(len, optlen))
4017 return -EFAULT;
4018 if (copy_to_user(optval, data, len))
4019 return -EFAULT;
4020 return 0;
4021}
4022
4023
4024#ifdef CONFIG_COMPAT
4025static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
4026 char __user *optval, unsigned int optlen)
4027{
4028 struct packet_sock *po = pkt_sk(sock->sk);
4029
4030 if (level != SOL_PACKET)
4031 return -ENOPROTOOPT;
4032
4033 if (optname == PACKET_FANOUT_DATA &&
4034 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
4035 optval = (char __user *)get_compat_bpf_fprog(optval);
4036 if (!optval)
4037 return -EFAULT;
4038 optlen = sizeof(struct sock_fprog);
4039 }
4040
4041 return packet_setsockopt(sock, level, optname, optval, optlen);
4042}
4043#endif
4044
4045static int packet_notifier(struct notifier_block *this,
4046 unsigned long msg, void *ptr)
4047{
4048 struct sock *sk;
4049 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4050 struct net *net = dev_net(dev);
4051
4052 rcu_read_lock();
4053 sk_for_each_rcu(sk, &net->packet.sklist) {
4054 struct packet_sock *po = pkt_sk(sk);
4055
4056 switch (msg) {
4057 case NETDEV_UNREGISTER:
4058 if (po->mclist)
4059 packet_dev_mclist_delete(dev, &po->mclist);
4060 /* fallthrough */
4061
4062 case NETDEV_DOWN:
4063 if (dev->ifindex == po->ifindex) {
4064 spin_lock(&po->bind_lock);
4065 if (po->running) {
4066 __unregister_prot_hook(sk, false);
4067 sk->sk_err = ENETDOWN;
4068 if (!sock_flag(sk, SOCK_DEAD))
4069 sk->sk_error_report(sk);
4070 }
4071 if (msg == NETDEV_UNREGISTER) {
4072 packet_cached_dev_reset(po);
4073 po->ifindex = -1;
4074 if (po->prot_hook.dev)
4075 dev_put(po->prot_hook.dev);
4076 po->prot_hook.dev = NULL;
4077 }
4078 spin_unlock(&po->bind_lock);
4079 }
4080 break;
4081 case NETDEV_UP:
4082 if (dev->ifindex == po->ifindex) {
4083 spin_lock(&po->bind_lock);
4084 if (po->num)
4085 register_prot_hook(sk);
4086 spin_unlock(&po->bind_lock);
4087 }
4088 break;
4089 }
4090 }
4091 rcu_read_unlock();
4092 return NOTIFY_DONE;
4093}
4094
4095
4096static int packet_ioctl(struct socket *sock, unsigned int cmd,
4097 unsigned long arg)
4098{
4099 struct sock *sk = sock->sk;
4100
4101 switch (cmd) {
4102 case SIOCOUTQ:
4103 {
4104 int amount = sk_wmem_alloc_get(sk);
4105
4106 return put_user(amount, (int __user *)arg);
4107 }
4108 case SIOCINQ:
4109 {
4110 struct sk_buff *skb;
4111 int amount = 0;
4112
4113 spin_lock_bh(&sk->sk_receive_queue.lock);
4114 skb = skb_peek(&sk->sk_receive_queue);
4115 if (skb)
4116 amount = skb->len;
4117 spin_unlock_bh(&sk->sk_receive_queue.lock);
4118 return put_user(amount, (int __user *)arg);
4119 }
4120#ifdef CONFIG_INET
4121 case SIOCADDRT:
4122 case SIOCDELRT:
4123 case SIOCDARP:
4124 case SIOCGARP:
4125 case SIOCSARP:
4126 case SIOCGIFADDR:
4127 case SIOCSIFADDR:
4128 case SIOCGIFBRDADDR:
4129 case SIOCSIFBRDADDR:
4130 case SIOCGIFNETMASK:
4131 case SIOCSIFNETMASK:
4132 case SIOCGIFDSTADDR:
4133 case SIOCSIFDSTADDR:
4134 case SIOCSIFFLAGS:
4135 return inet_dgram_ops.ioctl(sock, cmd, arg);
4136#endif
4137
4138 default:
4139 return -ENOIOCTLCMD;
4140 }
4141 return 0;
4142}
4143
4144static __poll_t packet_poll(struct file *file, struct socket *sock,
4145 poll_table *wait)
4146{
4147 struct sock *sk = sock->sk;
4148 struct packet_sock *po = pkt_sk(sk);
4149 __poll_t mask = datagram_poll(file, sock, wait);
4150
4151 spin_lock_bh(&sk->sk_receive_queue.lock);
4152 if (po->rx_ring.pg_vec) {
4153 if (!packet_previous_rx_frame(po, &po->rx_ring,
4154 TP_STATUS_KERNEL))
4155 mask |= EPOLLIN | EPOLLRDNORM;
4156 }
4157 packet_rcv_try_clear_pressure(po);
4158 spin_unlock_bh(&sk->sk_receive_queue.lock);
4159 spin_lock_bh(&sk->sk_write_queue.lock);
4160 if (po->tx_ring.pg_vec) {
4161 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4162 mask |= EPOLLOUT | EPOLLWRNORM;
4163 }
4164 spin_unlock_bh(&sk->sk_write_queue.lock);
4165 return mask;
4166}
4167
4168
4169/* Dirty? Well, I still did not learn better way to account
4170 * for user mmaps.
4171 */
4172
4173static void packet_mm_open(struct vm_area_struct *vma)
4174{
4175 struct file *file = vma->vm_file;
4176 struct socket *sock = file->private_data;
4177 struct sock *sk = sock->sk;
4178
4179 if (sk)
4180 atomic_inc(&pkt_sk(sk)->mapped);
4181}
4182
4183static void packet_mm_close(struct vm_area_struct *vma)
4184{
4185 struct file *file = vma->vm_file;
4186 struct socket *sock = file->private_data;
4187 struct sock *sk = sock->sk;
4188
4189 if (sk)
4190 atomic_dec(&pkt_sk(sk)->mapped);
4191}
4192
4193static const struct vm_operations_struct packet_mmap_ops = {
4194 .open = packet_mm_open,
4195 .close = packet_mm_close,
4196};
4197
4198static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4199 unsigned int len)
4200{
4201 int i;
4202
4203 for (i = 0; i < len; i++) {
4204 if (likely(pg_vec[i].buffer)) {
4205 if (is_vmalloc_addr(pg_vec[i].buffer))
4206 vfree(pg_vec[i].buffer);
4207 else
4208 free_pages((unsigned long)pg_vec[i].buffer,
4209 order);
4210 pg_vec[i].buffer = NULL;
4211 }
4212 }
4213 kfree(pg_vec);
4214}
4215
4216static char *alloc_one_pg_vec_page(unsigned long order)
4217{
4218 char *buffer;
4219 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4220 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4221
4222 buffer = (char *) __get_free_pages(gfp_flags, order);
4223 if (buffer)
4224 return buffer;
4225
4226 /* __get_free_pages failed, fall back to vmalloc */
4227 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4228 if (buffer)
4229 return buffer;
4230
4231 /* vmalloc failed, lets dig into swap here */
4232 gfp_flags &= ~__GFP_NORETRY;
4233 buffer = (char *) __get_free_pages(gfp_flags, order);
4234 if (buffer)
4235 return buffer;
4236
4237 /* complete and utter failure */
4238 return NULL;
4239}
4240
4241static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4242{
4243 unsigned int block_nr = req->tp_block_nr;
4244 struct pgv *pg_vec;
4245 int i;
4246
4247 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4248 if (unlikely(!pg_vec))
4249 goto out;
4250
4251 for (i = 0; i < block_nr; i++) {
4252 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4253 if (unlikely(!pg_vec[i].buffer))
4254 goto out_free_pgvec;
4255 }
4256
4257out:
4258 return pg_vec;
4259
4260out_free_pgvec:
4261 free_pg_vec(pg_vec, order, block_nr);
4262 pg_vec = NULL;
4263 goto out;
4264}
4265
4266static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4267 int closing, int tx_ring)
4268{
4269 struct pgv *pg_vec = NULL;
4270 struct packet_sock *po = pkt_sk(sk);
4271 int was_running, order = 0;
4272 struct packet_ring_buffer *rb;
4273 struct sk_buff_head *rb_queue;
4274 __be16 num;
4275 int err = -EINVAL;
4276 /* Added to avoid minimal code churn */
4277 struct tpacket_req *req = &req_u->req;
4278
4279 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4280 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4281
4282 err = -EBUSY;
4283 if (!closing) {
4284 if (atomic_read(&po->mapped))
4285 goto out;
4286 if (packet_read_pending(rb))
4287 goto out;
4288 }
4289
4290 if (req->tp_block_nr) {
4291 unsigned int min_frame_size;
4292
4293 /* Sanity tests and some calculations */
4294 err = -EBUSY;
4295 if (unlikely(rb->pg_vec))
4296 goto out;
4297
4298 switch (po->tp_version) {
4299 case TPACKET_V1:
4300 po->tp_hdrlen = TPACKET_HDRLEN;
4301 break;
4302 case TPACKET_V2:
4303 po->tp_hdrlen = TPACKET2_HDRLEN;
4304 break;
4305 case TPACKET_V3:
4306 po->tp_hdrlen = TPACKET3_HDRLEN;
4307 break;
4308 }
4309
4310 err = -EINVAL;
4311 if (unlikely((int)req->tp_block_size <= 0))
4312 goto out;
4313 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4314 goto out;
4315 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4316 if (po->tp_version >= TPACKET_V3 &&
4317 req->tp_block_size <
4318 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4319 goto out;
4320 if (unlikely(req->tp_frame_size < min_frame_size))
4321 goto out;
4322 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4323 goto out;
4324
4325 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4326 if (unlikely(rb->frames_per_block == 0))
4327 goto out;
4328 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4329 goto out;
4330 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4331 req->tp_frame_nr))
4332 goto out;
4333
4334 err = -ENOMEM;
4335 order = get_order(req->tp_block_size);
4336 pg_vec = alloc_pg_vec(req, order);
4337 if (unlikely(!pg_vec))
4338 goto out;
4339 switch (po->tp_version) {
4340 case TPACKET_V3:
4341 /* Block transmit is not supported yet */
4342 if (!tx_ring) {
4343 init_prb_bdqc(po, rb, pg_vec, req_u);
4344 } else {
4345 struct tpacket_req3 *req3 = &req_u->req3;
4346
4347 if (req3->tp_retire_blk_tov ||
4348 req3->tp_sizeof_priv ||
4349 req3->tp_feature_req_word) {
4350 err = -EINVAL;
4351 goto out_free_pg_vec;
4352 }
4353 }
4354 break;
4355 default:
4356 break;
4357 }
4358 }
4359 /* Done */
4360 else {
4361 err = -EINVAL;
4362 if (unlikely(req->tp_frame_nr))
4363 goto out;
4364 }
4365
4366
4367 /* Detach socket from network */
4368 spin_lock(&po->bind_lock);
4369 was_running = po->running;
4370 num = po->num;
4371 if (was_running) {
4372 po->num = 0;
4373 __unregister_prot_hook(sk, false);
4374 }
4375 spin_unlock(&po->bind_lock);
4376
4377 synchronize_net();
4378
4379 err = -EBUSY;
4380 mutex_lock(&po->pg_vec_lock);
4381 if (closing || atomic_read(&po->mapped) == 0) {
4382 err = 0;
4383 spin_lock_bh(&rb_queue->lock);
4384 swap(rb->pg_vec, pg_vec);
4385 rb->frame_max = (req->tp_frame_nr - 1);
4386 rb->head = 0;
4387 rb->frame_size = req->tp_frame_size;
4388 spin_unlock_bh(&rb_queue->lock);
4389
4390 swap(rb->pg_vec_order, order);
4391 swap(rb->pg_vec_len, req->tp_block_nr);
4392
4393 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4394 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4395 tpacket_rcv : packet_rcv;
4396 skb_queue_purge(rb_queue);
4397 if (atomic_read(&po->mapped))
4398 pr_err("packet_mmap: vma is busy: %d\n",
4399 atomic_read(&po->mapped));
4400 }
4401 mutex_unlock(&po->pg_vec_lock);
4402
4403 spin_lock(&po->bind_lock);
4404 if (was_running) {
4405 po->num = num;
4406 register_prot_hook(sk);
4407 }
4408 spin_unlock(&po->bind_lock);
4409 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4410 /* Because we don't support block-based V3 on tx-ring */
4411 if (!tx_ring)
4412 prb_shutdown_retire_blk_timer(po, rb_queue);
4413 }
4414
4415out_free_pg_vec:
4416 if (pg_vec)
4417 free_pg_vec(pg_vec, order, req->tp_block_nr);
4418out:
4419 return err;
4420}
4421
4422static int packet_mmap(struct file *file, struct socket *sock,
4423 struct vm_area_struct *vma)
4424{
4425 struct sock *sk = sock->sk;
4426 struct packet_sock *po = pkt_sk(sk);
4427 unsigned long size, expected_size;
4428 struct packet_ring_buffer *rb;
4429 unsigned long start;
4430 int err = -EINVAL;
4431 int i;
4432
4433 if (vma->vm_pgoff)
4434 return -EINVAL;
4435
4436 mutex_lock(&po->pg_vec_lock);
4437
4438 expected_size = 0;
4439 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4440 if (rb->pg_vec) {
4441 expected_size += rb->pg_vec_len
4442 * rb->pg_vec_pages
4443 * PAGE_SIZE;
4444 }
4445 }
4446
4447 if (expected_size == 0)
4448 goto out;
4449
4450 size = vma->vm_end - vma->vm_start;
4451 if (size != expected_size)
4452 goto out;
4453
4454 start = vma->vm_start;
4455 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4456 if (rb->pg_vec == NULL)
4457 continue;
4458
4459 for (i = 0; i < rb->pg_vec_len; i++) {
4460 struct page *page;
4461 void *kaddr = rb->pg_vec[i].buffer;
4462 int pg_num;
4463
4464 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4465 page = pgv_to_page(kaddr);
4466 err = vm_insert_page(vma, start, page);
4467 if (unlikely(err))
4468 goto out;
4469 start += PAGE_SIZE;
4470 kaddr += PAGE_SIZE;
4471 }
4472 }
4473 }
4474
4475 atomic_inc(&po->mapped);
4476 vma->vm_ops = &packet_mmap_ops;
4477 err = 0;
4478
4479out:
4480 mutex_unlock(&po->pg_vec_lock);
4481 return err;
4482}
4483
4484static const struct proto_ops packet_ops_spkt = {
4485 .family = PF_PACKET,
4486 .owner = THIS_MODULE,
4487 .release = packet_release,
4488 .bind = packet_bind_spkt,
4489 .connect = sock_no_connect,
4490 .socketpair = sock_no_socketpair,
4491 .accept = sock_no_accept,
4492 .getname = packet_getname_spkt,
4493 .poll = datagram_poll,
4494 .ioctl = packet_ioctl,
4495 .gettstamp = sock_gettstamp,
4496 .listen = sock_no_listen,
4497 .shutdown = sock_no_shutdown,
4498 .setsockopt = sock_no_setsockopt,
4499 .getsockopt = sock_no_getsockopt,
4500 .sendmsg = packet_sendmsg_spkt,
4501 .recvmsg = packet_recvmsg,
4502 .mmap = sock_no_mmap,
4503 .sendpage = sock_no_sendpage,
4504};
4505
4506static const struct proto_ops packet_ops = {
4507 .family = PF_PACKET,
4508 .owner = THIS_MODULE,
4509 .release = packet_release,
4510 .bind = packet_bind,
4511 .connect = sock_no_connect,
4512 .socketpair = sock_no_socketpair,
4513 .accept = sock_no_accept,
4514 .getname = packet_getname,
4515 .poll = packet_poll,
4516 .ioctl = packet_ioctl,
4517 .gettstamp = sock_gettstamp,
4518 .listen = sock_no_listen,
4519 .shutdown = sock_no_shutdown,
4520 .setsockopt = packet_setsockopt,
4521 .getsockopt = packet_getsockopt,
4522#ifdef CONFIG_COMPAT
4523 .compat_setsockopt = compat_packet_setsockopt,
4524#endif
4525 .sendmsg = packet_sendmsg,
4526 .recvmsg = packet_recvmsg,
4527 .mmap = packet_mmap,
4528 .sendpage = sock_no_sendpage,
4529};
4530
4531static const struct net_proto_family packet_family_ops = {
4532 .family = PF_PACKET,
4533 .create = packet_create,
4534 .owner = THIS_MODULE,
4535};
4536
4537static struct notifier_block packet_netdev_notifier = {
4538 .notifier_call = packet_notifier,
4539};
4540
4541#ifdef CONFIG_PROC_FS
4542
4543static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4544 __acquires(RCU)
4545{
4546 struct net *net = seq_file_net(seq);
4547
4548 rcu_read_lock();
4549 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4550}
4551
4552static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4553{
4554 struct net *net = seq_file_net(seq);
4555 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4556}
4557
4558static void packet_seq_stop(struct seq_file *seq, void *v)
4559 __releases(RCU)
4560{
4561 rcu_read_unlock();
4562}
4563
4564static int packet_seq_show(struct seq_file *seq, void *v)
4565{
4566 if (v == SEQ_START_TOKEN)
4567 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4568 else {
4569 struct sock *s = sk_entry(v);
4570 const struct packet_sock *po = pkt_sk(s);
4571
4572 seq_printf(seq,
4573 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4574 s,
4575 refcount_read(&s->sk_refcnt),
4576 s->sk_type,
4577 ntohs(po->num),
4578 po->ifindex,
4579 po->running,
4580 atomic_read(&s->sk_rmem_alloc),
4581 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4582 sock_i_ino(s));
4583 }
4584
4585 return 0;
4586}
4587
4588static const struct seq_operations packet_seq_ops = {
4589 .start = packet_seq_start,
4590 .next = packet_seq_next,
4591 .stop = packet_seq_stop,
4592 .show = packet_seq_show,
4593};
4594#endif
4595
4596static int __net_init packet_net_init(struct net *net)
4597{
4598 mutex_init(&net->packet.sklist_lock);
4599 INIT_HLIST_HEAD(&net->packet.sklist);
4600
4601 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4602 sizeof(struct seq_net_private)))
4603 return -ENOMEM;
4604
4605 return 0;
4606}
4607
4608static void __net_exit packet_net_exit(struct net *net)
4609{
4610 remove_proc_entry("packet", net->proc_net);
4611 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4612}
4613
4614static struct pernet_operations packet_net_ops = {
4615 .init = packet_net_init,
4616 .exit = packet_net_exit,
4617};
4618
4619
4620static void __exit packet_exit(void)
4621{
4622 unregister_netdevice_notifier(&packet_netdev_notifier);
4623 unregister_pernet_subsys(&packet_net_ops);
4624 sock_unregister(PF_PACKET);
4625 proto_unregister(&packet_proto);
4626}
4627
4628static int __init packet_init(void)
4629{
4630 int rc;
4631
4632 rc = proto_register(&packet_proto, 0);
4633 if (rc)
4634 goto out;
4635 rc = sock_register(&packet_family_ops);
4636 if (rc)
4637 goto out_proto;
4638 rc = register_pernet_subsys(&packet_net_ops);
4639 if (rc)
4640 goto out_sock;
4641 rc = register_netdevice_notifier(&packet_netdev_notifier);
4642 if (rc)
4643 goto out_pernet;
4644
4645 return 0;
4646
4647out_pernet:
4648 unregister_pernet_subsys(&packet_net_ops);
4649out_sock:
4650 sock_unregister(PF_PACKET);
4651out_proto:
4652 proto_unregister(&packet_proto);
4653out:
4654 return rc;
4655}
4656
4657module_init(packet_init);
4658module_exit(packet_exit);
4659MODULE_LICENSE("GPL");
4660MODULE_ALIAS_NETPROTO(PF_PACKET);