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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/ethtool.h>
50#include <linux/types.h>
51#include <linux/mm.h>
52#include <linux/capability.h>
53#include <linux/fcntl.h>
54#include <linux/socket.h>
55#include <linux/in.h>
56#include <linux/inet.h>
57#include <linux/netdevice.h>
58#include <linux/if_packet.h>
59#include <linux/wireless.h>
60#include <linux/kernel.h>
61#include <linux/kmod.h>
62#include <linux/slab.h>
63#include <linux/vmalloc.h>
64#include <net/net_namespace.h>
65#include <net/ip.h>
66#include <net/protocol.h>
67#include <linux/skbuff.h>
68#include <net/sock.h>
69#include <linux/errno.h>
70#include <linux/timer.h>
71#include <linux/uaccess.h>
72#include <asm/ioctls.h>
73#include <asm/page.h>
74#include <asm/cacheflush.h>
75#include <asm/io.h>
76#include <linux/proc_fs.h>
77#include <linux/seq_file.h>
78#include <linux/poll.h>
79#include <linux/module.h>
80#include <linux/init.h>
81#include <linux/mutex.h>
82#include <linux/if_vlan.h>
83#include <linux/virtio_net.h>
84#include <linux/errqueue.h>
85#include <linux/net_tstamp.h>
86#include <linux/percpu.h>
87#ifdef CONFIG_INET
88#include <net/inet_common.h>
89#endif
90#include <linux/bpf.h>
91#include <net/compat.h>
92
93#include "internal.h"
94
95/*
96 Assumptions:
97 - If the device has no dev->header_ops->create, there is no LL header
98 visible above the device. In this case, its hard_header_len should be 0.
99 The device may prepend its own header internally. In this case, its
100 needed_headroom should be set to the space needed for it to add its
101 internal header.
102 For example, a WiFi driver pretending to be an Ethernet driver should
103 set its hard_header_len to be the Ethernet header length, and set its
104 needed_headroom to be (the real WiFi header length - the fake Ethernet
105 header length).
106 - packet socket receives packets with pulled ll header,
107 so that SOCK_RAW should push it back.
108
109On receive:
110-----------
111
112Incoming, dev_has_header(dev) == true
113 mac_header -> ll header
114 data -> data
115
116Outgoing, dev_has_header(dev) == true
117 mac_header -> ll header
118 data -> ll header
119
120Incoming, dev_has_header(dev) == false
121 mac_header -> data
122 However drivers often make it point to the ll header.
123 This is incorrect because the ll header should be invisible to us.
124 data -> data
125
126Outgoing, dev_has_header(dev) == false
127 mac_header -> data. ll header is invisible to us.
128 data -> data
129
130Resume
131 If dev_has_header(dev) == false we are unable to restore the ll header,
132 because it is invisible to us.
133
134
135On transmit:
136------------
137
138dev_has_header(dev) == true
139 mac_header -> ll header
140 data -> ll header
141
142dev_has_header(dev) == false (ll header is invisible to us)
143 mac_header -> data
144 data -> data
145
146 We should set network_header on output to the correct position,
147 packet classifier depends on it.
148 */
149
150/* Private packet socket structures. */
151
152/* identical to struct packet_mreq except it has
153 * a longer address field.
154 */
155struct packet_mreq_max {
156 int mr_ifindex;
157 unsigned short mr_type;
158 unsigned short mr_alen;
159 unsigned char mr_address[MAX_ADDR_LEN];
160};
161
162union tpacket_uhdr {
163 struct tpacket_hdr *h1;
164 struct tpacket2_hdr *h2;
165 struct tpacket3_hdr *h3;
166 void *raw;
167};
168
169static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
170 int closing, int tx_ring);
171
172#define V3_ALIGNMENT (8)
173
174#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
175
176#define BLK_PLUS_PRIV(sz_of_priv) \
177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
178
179#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
180#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
181#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
182#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
183#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
184#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
185
186struct packet_sock;
187static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
188 struct packet_type *pt, struct net_device *orig_dev);
189
190static void *packet_previous_frame(struct packet_sock *po,
191 struct packet_ring_buffer *rb,
192 int status);
193static void packet_increment_head(struct packet_ring_buffer *buff);
194static int prb_curr_blk_in_use(struct tpacket_block_desc *);
195static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
196 struct packet_sock *);
197static void prb_retire_current_block(struct tpacket_kbdq_core *,
198 struct packet_sock *, unsigned int status);
199static int prb_queue_frozen(struct tpacket_kbdq_core *);
200static void prb_open_block(struct tpacket_kbdq_core *,
201 struct tpacket_block_desc *);
202static void prb_retire_rx_blk_timer_expired(struct timer_list *);
203static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
204static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
205static void prb_clear_rxhash(struct tpacket_kbdq_core *,
206 struct tpacket3_hdr *);
207static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
208 struct tpacket3_hdr *);
209static void packet_flush_mclist(struct sock *sk);
210static u16 packet_pick_tx_queue(struct sk_buff *skb);
211
212struct packet_skb_cb {
213 union {
214 struct sockaddr_pkt pkt;
215 union {
216 /* Trick: alias skb original length with
217 * ll.sll_family and ll.protocol in order
218 * to save room.
219 */
220 unsigned int origlen;
221 struct sockaddr_ll ll;
222 };
223 } sa;
224};
225
226#define vio_le() virtio_legacy_is_little_endian()
227
228#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
229
230#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
231#define GET_PBLOCK_DESC(x, bid) \
232 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
233#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
234 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
235#define GET_NEXT_PRB_BLK_NUM(x) \
236 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
237 ((x)->kactive_blk_num+1) : 0)
238
239static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
240static void __fanout_link(struct sock *sk, struct packet_sock *po);
241
242static int packet_direct_xmit(struct sk_buff *skb)
243{
244 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
245}
246
247static struct net_device *packet_cached_dev_get(struct packet_sock *po)
248{
249 struct net_device *dev;
250
251 rcu_read_lock();
252 dev = rcu_dereference(po->cached_dev);
253 if (likely(dev))
254 dev_hold(dev);
255 rcu_read_unlock();
256
257 return dev;
258}
259
260static void packet_cached_dev_assign(struct packet_sock *po,
261 struct net_device *dev)
262{
263 rcu_assign_pointer(po->cached_dev, dev);
264}
265
266static void packet_cached_dev_reset(struct packet_sock *po)
267{
268 RCU_INIT_POINTER(po->cached_dev, NULL);
269}
270
271static bool packet_use_direct_xmit(const struct packet_sock *po)
272{
273 return po->xmit == packet_direct_xmit;
274}
275
276static u16 packet_pick_tx_queue(struct sk_buff *skb)
277{
278 struct net_device *dev = skb->dev;
279 const struct net_device_ops *ops = dev->netdev_ops;
280 int cpu = raw_smp_processor_id();
281 u16 queue_index;
282
283#ifdef CONFIG_XPS
284 skb->sender_cpu = cpu + 1;
285#endif
286 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
287 if (ops->ndo_select_queue) {
288 queue_index = ops->ndo_select_queue(dev, skb, NULL);
289 queue_index = netdev_cap_txqueue(dev, queue_index);
290 } else {
291 queue_index = netdev_pick_tx(dev, skb, NULL);
292 }
293
294 return queue_index;
295}
296
297/* __register_prot_hook must be invoked through register_prot_hook
298 * or from a context in which asynchronous accesses to the packet
299 * socket is not possible (packet_create()).
300 */
301static void __register_prot_hook(struct sock *sk)
302{
303 struct packet_sock *po = pkt_sk(sk);
304
305 if (!po->running) {
306 if (po->fanout)
307 __fanout_link(sk, po);
308 else
309 dev_add_pack(&po->prot_hook);
310
311 sock_hold(sk);
312 po->running = 1;
313 }
314}
315
316static void register_prot_hook(struct sock *sk)
317{
318 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
319 __register_prot_hook(sk);
320}
321
322/* If the sync parameter is true, we will temporarily drop
323 * the po->bind_lock and do a synchronize_net to make sure no
324 * asynchronous packet processing paths still refer to the elements
325 * of po->prot_hook. If the sync parameter is false, it is the
326 * callers responsibility to take care of this.
327 */
328static void __unregister_prot_hook(struct sock *sk, bool sync)
329{
330 struct packet_sock *po = pkt_sk(sk);
331
332 lockdep_assert_held_once(&po->bind_lock);
333
334 po->running = 0;
335
336 if (po->fanout)
337 __fanout_unlink(sk, po);
338 else
339 __dev_remove_pack(&po->prot_hook);
340
341 __sock_put(sk);
342
343 if (sync) {
344 spin_unlock(&po->bind_lock);
345 synchronize_net();
346 spin_lock(&po->bind_lock);
347 }
348}
349
350static void unregister_prot_hook(struct sock *sk, bool sync)
351{
352 struct packet_sock *po = pkt_sk(sk);
353
354 if (po->running)
355 __unregister_prot_hook(sk, sync);
356}
357
358static inline struct page * __pure pgv_to_page(void *addr)
359{
360 if (is_vmalloc_addr(addr))
361 return vmalloc_to_page(addr);
362 return virt_to_page(addr);
363}
364
365static void __packet_set_status(struct packet_sock *po, void *frame, int status)
366{
367 union tpacket_uhdr h;
368
369 h.raw = frame;
370 switch (po->tp_version) {
371 case TPACKET_V1:
372 h.h1->tp_status = status;
373 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
374 break;
375 case TPACKET_V2:
376 h.h2->tp_status = status;
377 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
378 break;
379 case TPACKET_V3:
380 h.h3->tp_status = status;
381 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
382 break;
383 default:
384 WARN(1, "TPACKET version not supported.\n");
385 BUG();
386 }
387
388 smp_wmb();
389}
390
391static int __packet_get_status(const struct packet_sock *po, void *frame)
392{
393 union tpacket_uhdr h;
394
395 smp_rmb();
396
397 h.raw = frame;
398 switch (po->tp_version) {
399 case TPACKET_V1:
400 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
401 return h.h1->tp_status;
402 case TPACKET_V2:
403 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
404 return h.h2->tp_status;
405 case TPACKET_V3:
406 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
407 return h.h3->tp_status;
408 default:
409 WARN(1, "TPACKET version not supported.\n");
410 BUG();
411 return 0;
412 }
413}
414
415static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
416 unsigned int flags)
417{
418 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
419
420 if (shhwtstamps &&
421 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
422 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
423 return TP_STATUS_TS_RAW_HARDWARE;
424
425 if ((flags & SOF_TIMESTAMPING_SOFTWARE) &&
426 ktime_to_timespec64_cond(skb->tstamp, ts))
427 return TP_STATUS_TS_SOFTWARE;
428
429 return 0;
430}
431
432static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
433 struct sk_buff *skb)
434{
435 union tpacket_uhdr h;
436 struct timespec64 ts;
437 __u32 ts_status;
438
439 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
440 return 0;
441
442 h.raw = frame;
443 /*
444 * versions 1 through 3 overflow the timestamps in y2106, since they
445 * all store the seconds in a 32-bit unsigned integer.
446 * If we create a version 4, that should have a 64-bit timestamp,
447 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
448 * nanoseconds.
449 */
450 switch (po->tp_version) {
451 case TPACKET_V1:
452 h.h1->tp_sec = ts.tv_sec;
453 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
454 break;
455 case TPACKET_V2:
456 h.h2->tp_sec = ts.tv_sec;
457 h.h2->tp_nsec = ts.tv_nsec;
458 break;
459 case TPACKET_V3:
460 h.h3->tp_sec = ts.tv_sec;
461 h.h3->tp_nsec = ts.tv_nsec;
462 break;
463 default:
464 WARN(1, "TPACKET version not supported.\n");
465 BUG();
466 }
467
468 /* one flush is safe, as both fields always lie on the same cacheline */
469 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
470 smp_wmb();
471
472 return ts_status;
473}
474
475static void *packet_lookup_frame(const struct packet_sock *po,
476 const struct packet_ring_buffer *rb,
477 unsigned int position,
478 int status)
479{
480 unsigned int pg_vec_pos, frame_offset;
481 union tpacket_uhdr h;
482
483 pg_vec_pos = position / rb->frames_per_block;
484 frame_offset = position % rb->frames_per_block;
485
486 h.raw = rb->pg_vec[pg_vec_pos].buffer +
487 (frame_offset * rb->frame_size);
488
489 if (status != __packet_get_status(po, h.raw))
490 return NULL;
491
492 return h.raw;
493}
494
495static void *packet_current_frame(struct packet_sock *po,
496 struct packet_ring_buffer *rb,
497 int status)
498{
499 return packet_lookup_frame(po, rb, rb->head, status);
500}
501
502static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
503{
504 del_timer_sync(&pkc->retire_blk_timer);
505}
506
507static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
508 struct sk_buff_head *rb_queue)
509{
510 struct tpacket_kbdq_core *pkc;
511
512 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
513
514 spin_lock_bh(&rb_queue->lock);
515 pkc->delete_blk_timer = 1;
516 spin_unlock_bh(&rb_queue->lock);
517
518 prb_del_retire_blk_timer(pkc);
519}
520
521static void prb_setup_retire_blk_timer(struct packet_sock *po)
522{
523 struct tpacket_kbdq_core *pkc;
524
525 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
526 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
527 0);
528 pkc->retire_blk_timer.expires = jiffies;
529}
530
531static int prb_calc_retire_blk_tmo(struct packet_sock *po,
532 int blk_size_in_bytes)
533{
534 struct net_device *dev;
535 unsigned int mbits, div;
536 struct ethtool_link_ksettings ecmd;
537 int err;
538
539 rtnl_lock();
540 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
541 if (unlikely(!dev)) {
542 rtnl_unlock();
543 return DEFAULT_PRB_RETIRE_TOV;
544 }
545 err = __ethtool_get_link_ksettings(dev, &ecmd);
546 rtnl_unlock();
547 if (err)
548 return DEFAULT_PRB_RETIRE_TOV;
549
550 /* If the link speed is so slow you don't really
551 * need to worry about perf anyways
552 */
553 if (ecmd.base.speed < SPEED_1000 ||
554 ecmd.base.speed == SPEED_UNKNOWN)
555 return DEFAULT_PRB_RETIRE_TOV;
556
557 div = ecmd.base.speed / 1000;
558 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
559
560 if (div)
561 mbits /= div;
562
563 if (div)
564 return mbits + 1;
565 return mbits;
566}
567
568static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
569 union tpacket_req_u *req_u)
570{
571 p1->feature_req_word = req_u->req3.tp_feature_req_word;
572}
573
574static void init_prb_bdqc(struct packet_sock *po,
575 struct packet_ring_buffer *rb,
576 struct pgv *pg_vec,
577 union tpacket_req_u *req_u)
578{
579 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
580 struct tpacket_block_desc *pbd;
581
582 memset(p1, 0x0, sizeof(*p1));
583
584 p1->knxt_seq_num = 1;
585 p1->pkbdq = pg_vec;
586 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
587 p1->pkblk_start = pg_vec[0].buffer;
588 p1->kblk_size = req_u->req3.tp_block_size;
589 p1->knum_blocks = req_u->req3.tp_block_nr;
590 p1->hdrlen = po->tp_hdrlen;
591 p1->version = po->tp_version;
592 p1->last_kactive_blk_num = 0;
593 po->stats.stats3.tp_freeze_q_cnt = 0;
594 if (req_u->req3.tp_retire_blk_tov)
595 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
596 else
597 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
598 req_u->req3.tp_block_size);
599 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
600 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
601 rwlock_init(&p1->blk_fill_in_prog_lock);
602
603 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
604 prb_init_ft_ops(p1, req_u);
605 prb_setup_retire_blk_timer(po);
606 prb_open_block(p1, pbd);
607}
608
609/* Do NOT update the last_blk_num first.
610 * Assumes sk_buff_head lock is held.
611 */
612static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
613{
614 mod_timer(&pkc->retire_blk_timer,
615 jiffies + pkc->tov_in_jiffies);
616 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
617}
618
619/*
620 * Timer logic:
621 * 1) We refresh the timer only when we open a block.
622 * By doing this we don't waste cycles refreshing the timer
623 * on packet-by-packet basis.
624 *
625 * With a 1MB block-size, on a 1Gbps line, it will take
626 * i) ~8 ms to fill a block + ii) memcpy etc.
627 * In this cut we are not accounting for the memcpy time.
628 *
629 * So, if the user sets the 'tmo' to 10ms then the timer
630 * will never fire while the block is still getting filled
631 * (which is what we want). However, the user could choose
632 * to close a block early and that's fine.
633 *
634 * But when the timer does fire, we check whether or not to refresh it.
635 * Since the tmo granularity is in msecs, it is not too expensive
636 * to refresh the timer, lets say every '8' msecs.
637 * Either the user can set the 'tmo' or we can derive it based on
638 * a) line-speed and b) block-size.
639 * prb_calc_retire_blk_tmo() calculates the tmo.
640 *
641 */
642static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
643{
644 struct packet_sock *po =
645 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
646 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
647 unsigned int frozen;
648 struct tpacket_block_desc *pbd;
649
650 spin_lock(&po->sk.sk_receive_queue.lock);
651
652 frozen = prb_queue_frozen(pkc);
653 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
654
655 if (unlikely(pkc->delete_blk_timer))
656 goto out;
657
658 /* We only need to plug the race when the block is partially filled.
659 * tpacket_rcv:
660 * lock(); increment BLOCK_NUM_PKTS; unlock()
661 * copy_bits() is in progress ...
662 * timer fires on other cpu:
663 * we can't retire the current block because copy_bits
664 * is in progress.
665 *
666 */
667 if (BLOCK_NUM_PKTS(pbd)) {
668 /* Waiting for skb_copy_bits to finish... */
669 write_lock(&pkc->blk_fill_in_prog_lock);
670 write_unlock(&pkc->blk_fill_in_prog_lock);
671 }
672
673 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
674 if (!frozen) {
675 if (!BLOCK_NUM_PKTS(pbd)) {
676 /* An empty block. Just refresh the timer. */
677 goto refresh_timer;
678 }
679 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
680 if (!prb_dispatch_next_block(pkc, po))
681 goto refresh_timer;
682 else
683 goto out;
684 } else {
685 /* Case 1. Queue was frozen because user-space was
686 * lagging behind.
687 */
688 if (prb_curr_blk_in_use(pbd)) {
689 /*
690 * Ok, user-space is still behind.
691 * So just refresh the timer.
692 */
693 goto refresh_timer;
694 } else {
695 /* Case 2. queue was frozen,user-space caught up,
696 * now the link went idle && the timer fired.
697 * We don't have a block to close.So we open this
698 * block and restart the timer.
699 * opening a block thaws the queue,restarts timer
700 * Thawing/timer-refresh is a side effect.
701 */
702 prb_open_block(pkc, pbd);
703 goto out;
704 }
705 }
706 }
707
708refresh_timer:
709 _prb_refresh_rx_retire_blk_timer(pkc);
710
711out:
712 spin_unlock(&po->sk.sk_receive_queue.lock);
713}
714
715static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
716 struct tpacket_block_desc *pbd1, __u32 status)
717{
718 /* Flush everything minus the block header */
719
720#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
721 u8 *start, *end;
722
723 start = (u8 *)pbd1;
724
725 /* Skip the block header(we know header WILL fit in 4K) */
726 start += PAGE_SIZE;
727
728 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
729 for (; start < end; start += PAGE_SIZE)
730 flush_dcache_page(pgv_to_page(start));
731
732 smp_wmb();
733#endif
734
735 /* Now update the block status. */
736
737 BLOCK_STATUS(pbd1) = status;
738
739 /* Flush the block header */
740
741#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
742 start = (u8 *)pbd1;
743 flush_dcache_page(pgv_to_page(start));
744
745 smp_wmb();
746#endif
747}
748
749/*
750 * Side effect:
751 *
752 * 1) flush the block
753 * 2) Increment active_blk_num
754 *
755 * Note:We DONT refresh the timer on purpose.
756 * Because almost always the next block will be opened.
757 */
758static void prb_close_block(struct tpacket_kbdq_core *pkc1,
759 struct tpacket_block_desc *pbd1,
760 struct packet_sock *po, unsigned int stat)
761{
762 __u32 status = TP_STATUS_USER | stat;
763
764 struct tpacket3_hdr *last_pkt;
765 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
766 struct sock *sk = &po->sk;
767
768 if (atomic_read(&po->tp_drops))
769 status |= TP_STATUS_LOSING;
770
771 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
772 last_pkt->tp_next_offset = 0;
773
774 /* Get the ts of the last pkt */
775 if (BLOCK_NUM_PKTS(pbd1)) {
776 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
777 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
778 } else {
779 /* Ok, we tmo'd - so get the current time.
780 *
781 * It shouldn't really happen as we don't close empty
782 * blocks. See prb_retire_rx_blk_timer_expired().
783 */
784 struct timespec64 ts;
785 ktime_get_real_ts64(&ts);
786 h1->ts_last_pkt.ts_sec = ts.tv_sec;
787 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
788 }
789
790 smp_wmb();
791
792 /* Flush the block */
793 prb_flush_block(pkc1, pbd1, status);
794
795 sk->sk_data_ready(sk);
796
797 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
798}
799
800static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
801{
802 pkc->reset_pending_on_curr_blk = 0;
803}
804
805/*
806 * Side effect of opening a block:
807 *
808 * 1) prb_queue is thawed.
809 * 2) retire_blk_timer is refreshed.
810 *
811 */
812static void prb_open_block(struct tpacket_kbdq_core *pkc1,
813 struct tpacket_block_desc *pbd1)
814{
815 struct timespec64 ts;
816 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
817
818 smp_rmb();
819
820 /* We could have just memset this but we will lose the
821 * flexibility of making the priv area sticky
822 */
823
824 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
825 BLOCK_NUM_PKTS(pbd1) = 0;
826 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
827
828 ktime_get_real_ts64(&ts);
829
830 h1->ts_first_pkt.ts_sec = ts.tv_sec;
831 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
832
833 pkc1->pkblk_start = (char *)pbd1;
834 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
835
836 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
837 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
838
839 pbd1->version = pkc1->version;
840 pkc1->prev = pkc1->nxt_offset;
841 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
842
843 prb_thaw_queue(pkc1);
844 _prb_refresh_rx_retire_blk_timer(pkc1);
845
846 smp_wmb();
847}
848
849/*
850 * Queue freeze logic:
851 * 1) Assume tp_block_nr = 8 blocks.
852 * 2) At time 't0', user opens Rx ring.
853 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
854 * 4) user-space is either sleeping or processing block '0'.
855 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
856 * it will close block-7,loop around and try to fill block '0'.
857 * call-flow:
858 * __packet_lookup_frame_in_block
859 * prb_retire_current_block()
860 * prb_dispatch_next_block()
861 * |->(BLOCK_STATUS == USER) evaluates to true
862 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
863 * 6) Now there are two cases:
864 * 6.1) Link goes idle right after the queue is frozen.
865 * But remember, the last open_block() refreshed the timer.
866 * When this timer expires,it will refresh itself so that we can
867 * re-open block-0 in near future.
868 * 6.2) Link is busy and keeps on receiving packets. This is a simple
869 * case and __packet_lookup_frame_in_block will check if block-0
870 * is free and can now be re-used.
871 */
872static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
873 struct packet_sock *po)
874{
875 pkc->reset_pending_on_curr_blk = 1;
876 po->stats.stats3.tp_freeze_q_cnt++;
877}
878
879#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
880
881/*
882 * If the next block is free then we will dispatch it
883 * and return a good offset.
884 * Else, we will freeze the queue.
885 * So, caller must check the return value.
886 */
887static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
888 struct packet_sock *po)
889{
890 struct tpacket_block_desc *pbd;
891
892 smp_rmb();
893
894 /* 1. Get current block num */
895 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
896
897 /* 2. If this block is currently in_use then freeze the queue */
898 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
899 prb_freeze_queue(pkc, po);
900 return NULL;
901 }
902
903 /*
904 * 3.
905 * open this block and return the offset where the first packet
906 * needs to get stored.
907 */
908 prb_open_block(pkc, pbd);
909 return (void *)pkc->nxt_offset;
910}
911
912static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
913 struct packet_sock *po, unsigned int status)
914{
915 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
916
917 /* retire/close the current block */
918 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
919 /*
920 * Plug the case where copy_bits() is in progress on
921 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
922 * have space to copy the pkt in the current block and
923 * called prb_retire_current_block()
924 *
925 * We don't need to worry about the TMO case because
926 * the timer-handler already handled this case.
927 */
928 if (!(status & TP_STATUS_BLK_TMO)) {
929 /* Waiting for skb_copy_bits to finish... */
930 write_lock(&pkc->blk_fill_in_prog_lock);
931 write_unlock(&pkc->blk_fill_in_prog_lock);
932 }
933 prb_close_block(pkc, pbd, po, status);
934 return;
935 }
936}
937
938static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
939{
940 return TP_STATUS_USER & BLOCK_STATUS(pbd);
941}
942
943static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
944{
945 return pkc->reset_pending_on_curr_blk;
946}
947
948static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
949 __releases(&pkc->blk_fill_in_prog_lock)
950{
951 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
952
953 read_unlock(&pkc->blk_fill_in_prog_lock);
954}
955
956static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
957 struct tpacket3_hdr *ppd)
958{
959 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
960}
961
962static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
963 struct tpacket3_hdr *ppd)
964{
965 ppd->hv1.tp_rxhash = 0;
966}
967
968static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
969 struct tpacket3_hdr *ppd)
970{
971 if (skb_vlan_tag_present(pkc->skb)) {
972 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
973 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
974 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
975 } else {
976 ppd->hv1.tp_vlan_tci = 0;
977 ppd->hv1.tp_vlan_tpid = 0;
978 ppd->tp_status = TP_STATUS_AVAILABLE;
979 }
980}
981
982static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
983 struct tpacket3_hdr *ppd)
984{
985 ppd->hv1.tp_padding = 0;
986 prb_fill_vlan_info(pkc, ppd);
987
988 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
989 prb_fill_rxhash(pkc, ppd);
990 else
991 prb_clear_rxhash(pkc, ppd);
992}
993
994static void prb_fill_curr_block(char *curr,
995 struct tpacket_kbdq_core *pkc,
996 struct tpacket_block_desc *pbd,
997 unsigned int len)
998 __acquires(&pkc->blk_fill_in_prog_lock)
999{
1000 struct tpacket3_hdr *ppd;
1001
1002 ppd = (struct tpacket3_hdr *)curr;
1003 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1004 pkc->prev = curr;
1005 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1006 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1007 BLOCK_NUM_PKTS(pbd) += 1;
1008 read_lock(&pkc->blk_fill_in_prog_lock);
1009 prb_run_all_ft_ops(pkc, ppd);
1010}
1011
1012/* Assumes caller has the sk->rx_queue.lock */
1013static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1014 struct sk_buff *skb,
1015 unsigned int len
1016 )
1017{
1018 struct tpacket_kbdq_core *pkc;
1019 struct tpacket_block_desc *pbd;
1020 char *curr, *end;
1021
1022 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1023 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1024
1025 /* Queue is frozen when user space is lagging behind */
1026 if (prb_queue_frozen(pkc)) {
1027 /*
1028 * Check if that last block which caused the queue to freeze,
1029 * is still in_use by user-space.
1030 */
1031 if (prb_curr_blk_in_use(pbd)) {
1032 /* Can't record this packet */
1033 return NULL;
1034 } else {
1035 /*
1036 * Ok, the block was released by user-space.
1037 * Now let's open that block.
1038 * opening a block also thaws the queue.
1039 * Thawing is a side effect.
1040 */
1041 prb_open_block(pkc, pbd);
1042 }
1043 }
1044
1045 smp_mb();
1046 curr = pkc->nxt_offset;
1047 pkc->skb = skb;
1048 end = (char *)pbd + pkc->kblk_size;
1049
1050 /* first try the current block */
1051 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1052 prb_fill_curr_block(curr, pkc, pbd, len);
1053 return (void *)curr;
1054 }
1055
1056 /* Ok, close the current block */
1057 prb_retire_current_block(pkc, po, 0);
1058
1059 /* Now, try to dispatch the next block */
1060 curr = (char *)prb_dispatch_next_block(pkc, po);
1061 if (curr) {
1062 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1063 prb_fill_curr_block(curr, pkc, pbd, len);
1064 return (void *)curr;
1065 }
1066
1067 /*
1068 * No free blocks are available.user_space hasn't caught up yet.
1069 * Queue was just frozen and now this packet will get dropped.
1070 */
1071 return NULL;
1072}
1073
1074static void *packet_current_rx_frame(struct packet_sock *po,
1075 struct sk_buff *skb,
1076 int status, unsigned int len)
1077{
1078 char *curr = NULL;
1079 switch (po->tp_version) {
1080 case TPACKET_V1:
1081 case TPACKET_V2:
1082 curr = packet_lookup_frame(po, &po->rx_ring,
1083 po->rx_ring.head, status);
1084 return curr;
1085 case TPACKET_V3:
1086 return __packet_lookup_frame_in_block(po, skb, len);
1087 default:
1088 WARN(1, "TPACKET version not supported\n");
1089 BUG();
1090 return NULL;
1091 }
1092}
1093
1094static void *prb_lookup_block(const struct packet_sock *po,
1095 const struct packet_ring_buffer *rb,
1096 unsigned int idx,
1097 int status)
1098{
1099 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1100 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1101
1102 if (status != BLOCK_STATUS(pbd))
1103 return NULL;
1104 return pbd;
1105}
1106
1107static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1108{
1109 unsigned int prev;
1110 if (rb->prb_bdqc.kactive_blk_num)
1111 prev = rb->prb_bdqc.kactive_blk_num-1;
1112 else
1113 prev = rb->prb_bdqc.knum_blocks-1;
1114 return prev;
1115}
1116
1117/* Assumes caller has held the rx_queue.lock */
1118static void *__prb_previous_block(struct packet_sock *po,
1119 struct packet_ring_buffer *rb,
1120 int status)
1121{
1122 unsigned int previous = prb_previous_blk_num(rb);
1123 return prb_lookup_block(po, rb, previous, status);
1124}
1125
1126static void *packet_previous_rx_frame(struct packet_sock *po,
1127 struct packet_ring_buffer *rb,
1128 int status)
1129{
1130 if (po->tp_version <= TPACKET_V2)
1131 return packet_previous_frame(po, rb, status);
1132
1133 return __prb_previous_block(po, rb, status);
1134}
1135
1136static void packet_increment_rx_head(struct packet_sock *po,
1137 struct packet_ring_buffer *rb)
1138{
1139 switch (po->tp_version) {
1140 case TPACKET_V1:
1141 case TPACKET_V2:
1142 return packet_increment_head(rb);
1143 case TPACKET_V3:
1144 default:
1145 WARN(1, "TPACKET version not supported.\n");
1146 BUG();
1147 return;
1148 }
1149}
1150
1151static void *packet_previous_frame(struct packet_sock *po,
1152 struct packet_ring_buffer *rb,
1153 int status)
1154{
1155 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1156 return packet_lookup_frame(po, rb, previous, status);
1157}
1158
1159static void packet_increment_head(struct packet_ring_buffer *buff)
1160{
1161 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1162}
1163
1164static void packet_inc_pending(struct packet_ring_buffer *rb)
1165{
1166 this_cpu_inc(*rb->pending_refcnt);
1167}
1168
1169static void packet_dec_pending(struct packet_ring_buffer *rb)
1170{
1171 this_cpu_dec(*rb->pending_refcnt);
1172}
1173
1174static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1175{
1176 unsigned int refcnt = 0;
1177 int cpu;
1178
1179 /* We don't use pending refcount in rx_ring. */
1180 if (rb->pending_refcnt == NULL)
1181 return 0;
1182
1183 for_each_possible_cpu(cpu)
1184 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1185
1186 return refcnt;
1187}
1188
1189static int packet_alloc_pending(struct packet_sock *po)
1190{
1191 po->rx_ring.pending_refcnt = NULL;
1192
1193 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1194 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1195 return -ENOBUFS;
1196
1197 return 0;
1198}
1199
1200static void packet_free_pending(struct packet_sock *po)
1201{
1202 free_percpu(po->tx_ring.pending_refcnt);
1203}
1204
1205#define ROOM_POW_OFF 2
1206#define ROOM_NONE 0x0
1207#define ROOM_LOW 0x1
1208#define ROOM_NORMAL 0x2
1209
1210static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1211{
1212 int idx, len;
1213
1214 len = READ_ONCE(po->rx_ring.frame_max) + 1;
1215 idx = READ_ONCE(po->rx_ring.head);
1216 if (pow_off)
1217 idx += len >> pow_off;
1218 if (idx >= len)
1219 idx -= len;
1220 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1221}
1222
1223static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1224{
1225 int idx, len;
1226
1227 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1228 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1229 if (pow_off)
1230 idx += len >> pow_off;
1231 if (idx >= len)
1232 idx -= len;
1233 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1234}
1235
1236static int __packet_rcv_has_room(const struct packet_sock *po,
1237 const struct sk_buff *skb)
1238{
1239 const struct sock *sk = &po->sk;
1240 int ret = ROOM_NONE;
1241
1242 if (po->prot_hook.func != tpacket_rcv) {
1243 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1244 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1245 - (skb ? skb->truesize : 0);
1246
1247 if (avail > (rcvbuf >> ROOM_POW_OFF))
1248 return ROOM_NORMAL;
1249 else if (avail > 0)
1250 return ROOM_LOW;
1251 else
1252 return ROOM_NONE;
1253 }
1254
1255 if (po->tp_version == TPACKET_V3) {
1256 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1257 ret = ROOM_NORMAL;
1258 else if (__tpacket_v3_has_room(po, 0))
1259 ret = ROOM_LOW;
1260 } else {
1261 if (__tpacket_has_room(po, ROOM_POW_OFF))
1262 ret = ROOM_NORMAL;
1263 else if (__tpacket_has_room(po, 0))
1264 ret = ROOM_LOW;
1265 }
1266
1267 return ret;
1268}
1269
1270static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1271{
1272 int pressure, ret;
1273
1274 ret = __packet_rcv_has_room(po, skb);
1275 pressure = ret != ROOM_NORMAL;
1276
1277 if (READ_ONCE(po->pressure) != pressure)
1278 WRITE_ONCE(po->pressure, pressure);
1279
1280 return ret;
1281}
1282
1283static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1284{
1285 if (READ_ONCE(po->pressure) &&
1286 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1287 WRITE_ONCE(po->pressure, 0);
1288}
1289
1290static void packet_sock_destruct(struct sock *sk)
1291{
1292 skb_queue_purge(&sk->sk_error_queue);
1293
1294 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1295 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1296
1297 if (!sock_flag(sk, SOCK_DEAD)) {
1298 pr_err("Attempt to release alive packet socket: %p\n", sk);
1299 return;
1300 }
1301
1302 sk_refcnt_debug_dec(sk);
1303}
1304
1305static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1306{
1307 u32 *history = po->rollover->history;
1308 u32 victim, rxhash;
1309 int i, count = 0;
1310
1311 rxhash = skb_get_hash(skb);
1312 for (i = 0; i < ROLLOVER_HLEN; i++)
1313 if (READ_ONCE(history[i]) == rxhash)
1314 count++;
1315
1316 victim = prandom_u32() % ROLLOVER_HLEN;
1317
1318 /* Avoid dirtying the cache line if possible */
1319 if (READ_ONCE(history[victim]) != rxhash)
1320 WRITE_ONCE(history[victim], rxhash);
1321
1322 return count > (ROLLOVER_HLEN >> 1);
1323}
1324
1325static unsigned int fanout_demux_hash(struct packet_fanout *f,
1326 struct sk_buff *skb,
1327 unsigned int num)
1328{
1329 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1330}
1331
1332static unsigned int fanout_demux_lb(struct packet_fanout *f,
1333 struct sk_buff *skb,
1334 unsigned int num)
1335{
1336 unsigned int val = atomic_inc_return(&f->rr_cur);
1337
1338 return val % num;
1339}
1340
1341static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1342 struct sk_buff *skb,
1343 unsigned int num)
1344{
1345 return smp_processor_id() % num;
1346}
1347
1348static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1349 struct sk_buff *skb,
1350 unsigned int num)
1351{
1352 return prandom_u32_max(num);
1353}
1354
1355static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1356 struct sk_buff *skb,
1357 unsigned int idx, bool try_self,
1358 unsigned int num)
1359{
1360 struct packet_sock *po, *po_next, *po_skip = NULL;
1361 unsigned int i, j, room = ROOM_NONE;
1362
1363 po = pkt_sk(rcu_dereference(f->arr[idx]));
1364
1365 if (try_self) {
1366 room = packet_rcv_has_room(po, skb);
1367 if (room == ROOM_NORMAL ||
1368 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1369 return idx;
1370 po_skip = po;
1371 }
1372
1373 i = j = min_t(int, po->rollover->sock, num - 1);
1374 do {
1375 po_next = pkt_sk(rcu_dereference(f->arr[i]));
1376 if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1377 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1378 if (i != j)
1379 po->rollover->sock = i;
1380 atomic_long_inc(&po->rollover->num);
1381 if (room == ROOM_LOW)
1382 atomic_long_inc(&po->rollover->num_huge);
1383 return i;
1384 }
1385
1386 if (++i == num)
1387 i = 0;
1388 } while (i != j);
1389
1390 atomic_long_inc(&po->rollover->num_failed);
1391 return idx;
1392}
1393
1394static unsigned int fanout_demux_qm(struct packet_fanout *f,
1395 struct sk_buff *skb,
1396 unsigned int num)
1397{
1398 return skb_get_queue_mapping(skb) % num;
1399}
1400
1401static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1402 struct sk_buff *skb,
1403 unsigned int num)
1404{
1405 struct bpf_prog *prog;
1406 unsigned int ret = 0;
1407
1408 rcu_read_lock();
1409 prog = rcu_dereference(f->bpf_prog);
1410 if (prog)
1411 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1412 rcu_read_unlock();
1413
1414 return ret;
1415}
1416
1417static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1418{
1419 return f->flags & (flag >> 8);
1420}
1421
1422static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1423 struct packet_type *pt, struct net_device *orig_dev)
1424{
1425 struct packet_fanout *f = pt->af_packet_priv;
1426 unsigned int num = READ_ONCE(f->num_members);
1427 struct net *net = read_pnet(&f->net);
1428 struct packet_sock *po;
1429 unsigned int idx;
1430
1431 if (!net_eq(dev_net(dev), net) || !num) {
1432 kfree_skb(skb);
1433 return 0;
1434 }
1435
1436 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1437 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1438 if (!skb)
1439 return 0;
1440 }
1441 switch (f->type) {
1442 case PACKET_FANOUT_HASH:
1443 default:
1444 idx = fanout_demux_hash(f, skb, num);
1445 break;
1446 case PACKET_FANOUT_LB:
1447 idx = fanout_demux_lb(f, skb, num);
1448 break;
1449 case PACKET_FANOUT_CPU:
1450 idx = fanout_demux_cpu(f, skb, num);
1451 break;
1452 case PACKET_FANOUT_RND:
1453 idx = fanout_demux_rnd(f, skb, num);
1454 break;
1455 case PACKET_FANOUT_QM:
1456 idx = fanout_demux_qm(f, skb, num);
1457 break;
1458 case PACKET_FANOUT_ROLLOVER:
1459 idx = fanout_demux_rollover(f, skb, 0, false, num);
1460 break;
1461 case PACKET_FANOUT_CBPF:
1462 case PACKET_FANOUT_EBPF:
1463 idx = fanout_demux_bpf(f, skb, num);
1464 break;
1465 }
1466
1467 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1468 idx = fanout_demux_rollover(f, skb, idx, true, num);
1469
1470 po = pkt_sk(rcu_dereference(f->arr[idx]));
1471 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1472}
1473
1474DEFINE_MUTEX(fanout_mutex);
1475EXPORT_SYMBOL_GPL(fanout_mutex);
1476static LIST_HEAD(fanout_list);
1477static u16 fanout_next_id;
1478
1479static void __fanout_link(struct sock *sk, struct packet_sock *po)
1480{
1481 struct packet_fanout *f = po->fanout;
1482
1483 spin_lock(&f->lock);
1484 rcu_assign_pointer(f->arr[f->num_members], sk);
1485 smp_wmb();
1486 f->num_members++;
1487 if (f->num_members == 1)
1488 dev_add_pack(&f->prot_hook);
1489 spin_unlock(&f->lock);
1490}
1491
1492static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1493{
1494 struct packet_fanout *f = po->fanout;
1495 int i;
1496
1497 spin_lock(&f->lock);
1498 for (i = 0; i < f->num_members; i++) {
1499 if (rcu_dereference_protected(f->arr[i],
1500 lockdep_is_held(&f->lock)) == sk)
1501 break;
1502 }
1503 BUG_ON(i >= f->num_members);
1504 rcu_assign_pointer(f->arr[i],
1505 rcu_dereference_protected(f->arr[f->num_members - 1],
1506 lockdep_is_held(&f->lock)));
1507 f->num_members--;
1508 if (f->num_members == 0)
1509 __dev_remove_pack(&f->prot_hook);
1510 spin_unlock(&f->lock);
1511}
1512
1513static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1514{
1515 if (sk->sk_family != PF_PACKET)
1516 return false;
1517
1518 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1519}
1520
1521static void fanout_init_data(struct packet_fanout *f)
1522{
1523 switch (f->type) {
1524 case PACKET_FANOUT_LB:
1525 atomic_set(&f->rr_cur, 0);
1526 break;
1527 case PACKET_FANOUT_CBPF:
1528 case PACKET_FANOUT_EBPF:
1529 RCU_INIT_POINTER(f->bpf_prog, NULL);
1530 break;
1531 }
1532}
1533
1534static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1535{
1536 struct bpf_prog *old;
1537
1538 spin_lock(&f->lock);
1539 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1540 rcu_assign_pointer(f->bpf_prog, new);
1541 spin_unlock(&f->lock);
1542
1543 if (old) {
1544 synchronize_net();
1545 bpf_prog_destroy(old);
1546 }
1547}
1548
1549static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1550 unsigned int len)
1551{
1552 struct bpf_prog *new;
1553 struct sock_fprog fprog;
1554 int ret;
1555
1556 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1557 return -EPERM;
1558
1559 ret = copy_bpf_fprog_from_user(&fprog, data, len);
1560 if (ret)
1561 return ret;
1562
1563 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1564 if (ret)
1565 return ret;
1566
1567 __fanout_set_data_bpf(po->fanout, new);
1568 return 0;
1569}
1570
1571static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1572 unsigned int len)
1573{
1574 struct bpf_prog *new;
1575 u32 fd;
1576
1577 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1578 return -EPERM;
1579 if (len != sizeof(fd))
1580 return -EINVAL;
1581 if (copy_from_sockptr(&fd, data, len))
1582 return -EFAULT;
1583
1584 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1585 if (IS_ERR(new))
1586 return PTR_ERR(new);
1587
1588 __fanout_set_data_bpf(po->fanout, new);
1589 return 0;
1590}
1591
1592static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1593 unsigned int len)
1594{
1595 switch (po->fanout->type) {
1596 case PACKET_FANOUT_CBPF:
1597 return fanout_set_data_cbpf(po, data, len);
1598 case PACKET_FANOUT_EBPF:
1599 return fanout_set_data_ebpf(po, data, len);
1600 default:
1601 return -EINVAL;
1602 }
1603}
1604
1605static void fanout_release_data(struct packet_fanout *f)
1606{
1607 switch (f->type) {
1608 case PACKET_FANOUT_CBPF:
1609 case PACKET_FANOUT_EBPF:
1610 __fanout_set_data_bpf(f, NULL);
1611 }
1612}
1613
1614static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1615{
1616 struct packet_fanout *f;
1617
1618 list_for_each_entry(f, &fanout_list, list) {
1619 if (f->id == candidate_id &&
1620 read_pnet(&f->net) == sock_net(sk)) {
1621 return false;
1622 }
1623 }
1624 return true;
1625}
1626
1627static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1628{
1629 u16 id = fanout_next_id;
1630
1631 do {
1632 if (__fanout_id_is_free(sk, id)) {
1633 *new_id = id;
1634 fanout_next_id = id + 1;
1635 return true;
1636 }
1637
1638 id++;
1639 } while (id != fanout_next_id);
1640
1641 return false;
1642}
1643
1644static int fanout_add(struct sock *sk, struct fanout_args *args)
1645{
1646 struct packet_rollover *rollover = NULL;
1647 struct packet_sock *po = pkt_sk(sk);
1648 u16 type_flags = args->type_flags;
1649 struct packet_fanout *f, *match;
1650 u8 type = type_flags & 0xff;
1651 u8 flags = type_flags >> 8;
1652 u16 id = args->id;
1653 int err;
1654
1655 switch (type) {
1656 case PACKET_FANOUT_ROLLOVER:
1657 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1658 return -EINVAL;
1659 break;
1660 case PACKET_FANOUT_HASH:
1661 case PACKET_FANOUT_LB:
1662 case PACKET_FANOUT_CPU:
1663 case PACKET_FANOUT_RND:
1664 case PACKET_FANOUT_QM:
1665 case PACKET_FANOUT_CBPF:
1666 case PACKET_FANOUT_EBPF:
1667 break;
1668 default:
1669 return -EINVAL;
1670 }
1671
1672 mutex_lock(&fanout_mutex);
1673
1674 err = -EALREADY;
1675 if (po->fanout)
1676 goto out;
1677
1678 if (type == PACKET_FANOUT_ROLLOVER ||
1679 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1680 err = -ENOMEM;
1681 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1682 if (!rollover)
1683 goto out;
1684 atomic_long_set(&rollover->num, 0);
1685 atomic_long_set(&rollover->num_huge, 0);
1686 atomic_long_set(&rollover->num_failed, 0);
1687 }
1688
1689 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1690 if (id != 0) {
1691 err = -EINVAL;
1692 goto out;
1693 }
1694 if (!fanout_find_new_id(sk, &id)) {
1695 err = -ENOMEM;
1696 goto out;
1697 }
1698 /* ephemeral flag for the first socket in the group: drop it */
1699 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1700 }
1701
1702 match = NULL;
1703 list_for_each_entry(f, &fanout_list, list) {
1704 if (f->id == id &&
1705 read_pnet(&f->net) == sock_net(sk)) {
1706 match = f;
1707 break;
1708 }
1709 }
1710 err = -EINVAL;
1711 if (match) {
1712 if (match->flags != flags)
1713 goto out;
1714 if (args->max_num_members &&
1715 args->max_num_members != match->max_num_members)
1716 goto out;
1717 } else {
1718 if (args->max_num_members > PACKET_FANOUT_MAX)
1719 goto out;
1720 if (!args->max_num_members)
1721 /* legacy PACKET_FANOUT_MAX */
1722 args->max_num_members = 256;
1723 err = -ENOMEM;
1724 match = kvzalloc(struct_size(match, arr, args->max_num_members),
1725 GFP_KERNEL);
1726 if (!match)
1727 goto out;
1728 write_pnet(&match->net, sock_net(sk));
1729 match->id = id;
1730 match->type = type;
1731 match->flags = flags;
1732 INIT_LIST_HEAD(&match->list);
1733 spin_lock_init(&match->lock);
1734 refcount_set(&match->sk_ref, 0);
1735 fanout_init_data(match);
1736 match->prot_hook.type = po->prot_hook.type;
1737 match->prot_hook.dev = po->prot_hook.dev;
1738 match->prot_hook.func = packet_rcv_fanout;
1739 match->prot_hook.af_packet_priv = match;
1740 match->prot_hook.id_match = match_fanout_group;
1741 match->max_num_members = args->max_num_members;
1742 list_add(&match->list, &fanout_list);
1743 }
1744 err = -EINVAL;
1745
1746 spin_lock(&po->bind_lock);
1747 if (po->running &&
1748 match->type == type &&
1749 match->prot_hook.type == po->prot_hook.type &&
1750 match->prot_hook.dev == po->prot_hook.dev) {
1751 err = -ENOSPC;
1752 if (refcount_read(&match->sk_ref) < match->max_num_members) {
1753 __dev_remove_pack(&po->prot_hook);
1754 po->fanout = match;
1755 po->rollover = rollover;
1756 rollover = NULL;
1757 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1758 __fanout_link(sk, po);
1759 err = 0;
1760 }
1761 }
1762 spin_unlock(&po->bind_lock);
1763
1764 if (err && !refcount_read(&match->sk_ref)) {
1765 list_del(&match->list);
1766 kvfree(match);
1767 }
1768
1769out:
1770 kfree(rollover);
1771 mutex_unlock(&fanout_mutex);
1772 return err;
1773}
1774
1775/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1776 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1777 * It is the responsibility of the caller to call fanout_release_data() and
1778 * free the returned packet_fanout (after synchronize_net())
1779 */
1780static struct packet_fanout *fanout_release(struct sock *sk)
1781{
1782 struct packet_sock *po = pkt_sk(sk);
1783 struct packet_fanout *f;
1784
1785 mutex_lock(&fanout_mutex);
1786 f = po->fanout;
1787 if (f) {
1788 po->fanout = NULL;
1789
1790 if (refcount_dec_and_test(&f->sk_ref))
1791 list_del(&f->list);
1792 else
1793 f = NULL;
1794 }
1795 mutex_unlock(&fanout_mutex);
1796
1797 return f;
1798}
1799
1800static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1801 struct sk_buff *skb)
1802{
1803 /* Earlier code assumed this would be a VLAN pkt, double-check
1804 * this now that we have the actual packet in hand. We can only
1805 * do this check on Ethernet devices.
1806 */
1807 if (unlikely(dev->type != ARPHRD_ETHER))
1808 return false;
1809
1810 skb_reset_mac_header(skb);
1811 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1812}
1813
1814static const struct proto_ops packet_ops;
1815
1816static const struct proto_ops packet_ops_spkt;
1817
1818static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1819 struct packet_type *pt, struct net_device *orig_dev)
1820{
1821 struct sock *sk;
1822 struct sockaddr_pkt *spkt;
1823
1824 /*
1825 * When we registered the protocol we saved the socket in the data
1826 * field for just this event.
1827 */
1828
1829 sk = pt->af_packet_priv;
1830
1831 /*
1832 * Yank back the headers [hope the device set this
1833 * right or kerboom...]
1834 *
1835 * Incoming packets have ll header pulled,
1836 * push it back.
1837 *
1838 * For outgoing ones skb->data == skb_mac_header(skb)
1839 * so that this procedure is noop.
1840 */
1841
1842 if (skb->pkt_type == PACKET_LOOPBACK)
1843 goto out;
1844
1845 if (!net_eq(dev_net(dev), sock_net(sk)))
1846 goto out;
1847
1848 skb = skb_share_check(skb, GFP_ATOMIC);
1849 if (skb == NULL)
1850 goto oom;
1851
1852 /* drop any routing info */
1853 skb_dst_drop(skb);
1854
1855 /* drop conntrack reference */
1856 nf_reset_ct(skb);
1857
1858 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1859
1860 skb_push(skb, skb->data - skb_mac_header(skb));
1861
1862 /*
1863 * The SOCK_PACKET socket receives _all_ frames.
1864 */
1865
1866 spkt->spkt_family = dev->type;
1867 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1868 spkt->spkt_protocol = skb->protocol;
1869
1870 /*
1871 * Charge the memory to the socket. This is done specifically
1872 * to prevent sockets using all the memory up.
1873 */
1874
1875 if (sock_queue_rcv_skb(sk, skb) == 0)
1876 return 0;
1877
1878out:
1879 kfree_skb(skb);
1880oom:
1881 return 0;
1882}
1883
1884static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1885{
1886 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1887 sock->type == SOCK_RAW) {
1888 skb_reset_mac_header(skb);
1889 skb->protocol = dev_parse_header_protocol(skb);
1890 }
1891
1892 skb_probe_transport_header(skb);
1893}
1894
1895/*
1896 * Output a raw packet to a device layer. This bypasses all the other
1897 * protocol layers and you must therefore supply it with a complete frame
1898 */
1899
1900static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1901 size_t len)
1902{
1903 struct sock *sk = sock->sk;
1904 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1905 struct sk_buff *skb = NULL;
1906 struct net_device *dev;
1907 struct sockcm_cookie sockc;
1908 __be16 proto = 0;
1909 int err;
1910 int extra_len = 0;
1911
1912 /*
1913 * Get and verify the address.
1914 */
1915
1916 if (saddr) {
1917 if (msg->msg_namelen < sizeof(struct sockaddr))
1918 return -EINVAL;
1919 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1920 proto = saddr->spkt_protocol;
1921 } else
1922 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1923
1924 /*
1925 * Find the device first to size check it
1926 */
1927
1928 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1929retry:
1930 rcu_read_lock();
1931 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1932 err = -ENODEV;
1933 if (dev == NULL)
1934 goto out_unlock;
1935
1936 err = -ENETDOWN;
1937 if (!(dev->flags & IFF_UP))
1938 goto out_unlock;
1939
1940 /*
1941 * You may not queue a frame bigger than the mtu. This is the lowest level
1942 * raw protocol and you must do your own fragmentation at this level.
1943 */
1944
1945 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1946 if (!netif_supports_nofcs(dev)) {
1947 err = -EPROTONOSUPPORT;
1948 goto out_unlock;
1949 }
1950 extra_len = 4; /* We're doing our own CRC */
1951 }
1952
1953 err = -EMSGSIZE;
1954 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1955 goto out_unlock;
1956
1957 if (!skb) {
1958 size_t reserved = LL_RESERVED_SPACE(dev);
1959 int tlen = dev->needed_tailroom;
1960 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1961
1962 rcu_read_unlock();
1963 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1964 if (skb == NULL)
1965 return -ENOBUFS;
1966 /* FIXME: Save some space for broken drivers that write a hard
1967 * header at transmission time by themselves. PPP is the notable
1968 * one here. This should really be fixed at the driver level.
1969 */
1970 skb_reserve(skb, reserved);
1971 skb_reset_network_header(skb);
1972
1973 /* Try to align data part correctly */
1974 if (hhlen) {
1975 skb->data -= hhlen;
1976 skb->tail -= hhlen;
1977 if (len < hhlen)
1978 skb_reset_network_header(skb);
1979 }
1980 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1981 if (err)
1982 goto out_free;
1983 goto retry;
1984 }
1985
1986 if (!dev_validate_header(dev, skb->data, len)) {
1987 err = -EINVAL;
1988 goto out_unlock;
1989 }
1990 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1991 !packet_extra_vlan_len_allowed(dev, skb)) {
1992 err = -EMSGSIZE;
1993 goto out_unlock;
1994 }
1995
1996 sockcm_init(&sockc, sk);
1997 if (msg->msg_controllen) {
1998 err = sock_cmsg_send(sk, msg, &sockc);
1999 if (unlikely(err))
2000 goto out_unlock;
2001 }
2002
2003 skb->protocol = proto;
2004 skb->dev = dev;
2005 skb->priority = sk->sk_priority;
2006 skb->mark = sk->sk_mark;
2007 skb->tstamp = sockc.transmit_time;
2008
2009 skb_setup_tx_timestamp(skb, sockc.tsflags);
2010
2011 if (unlikely(extra_len == 4))
2012 skb->no_fcs = 1;
2013
2014 packet_parse_headers(skb, sock);
2015
2016 dev_queue_xmit(skb);
2017 rcu_read_unlock();
2018 return len;
2019
2020out_unlock:
2021 rcu_read_unlock();
2022out_free:
2023 kfree_skb(skb);
2024 return err;
2025}
2026
2027static unsigned int run_filter(struct sk_buff *skb,
2028 const struct sock *sk,
2029 unsigned int res)
2030{
2031 struct sk_filter *filter;
2032
2033 rcu_read_lock();
2034 filter = rcu_dereference(sk->sk_filter);
2035 if (filter != NULL)
2036 res = bpf_prog_run_clear_cb(filter->prog, skb);
2037 rcu_read_unlock();
2038
2039 return res;
2040}
2041
2042static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2043 size_t *len)
2044{
2045 struct virtio_net_hdr vnet_hdr;
2046
2047 if (*len < sizeof(vnet_hdr))
2048 return -EINVAL;
2049 *len -= sizeof(vnet_hdr);
2050
2051 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2052 return -EINVAL;
2053
2054 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2055}
2056
2057/*
2058 * This function makes lazy skb cloning in hope that most of packets
2059 * are discarded by BPF.
2060 *
2061 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2062 * and skb->cb are mangled. It works because (and until) packets
2063 * falling here are owned by current CPU. Output packets are cloned
2064 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2065 * sequentially, so that if we return skb to original state on exit,
2066 * we will not harm anyone.
2067 */
2068
2069static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2070 struct packet_type *pt, struct net_device *orig_dev)
2071{
2072 struct sock *sk;
2073 struct sockaddr_ll *sll;
2074 struct packet_sock *po;
2075 u8 *skb_head = skb->data;
2076 int skb_len = skb->len;
2077 unsigned int snaplen, res;
2078 bool is_drop_n_account = false;
2079
2080 if (skb->pkt_type == PACKET_LOOPBACK)
2081 goto drop;
2082
2083 sk = pt->af_packet_priv;
2084 po = pkt_sk(sk);
2085
2086 if (!net_eq(dev_net(dev), sock_net(sk)))
2087 goto drop;
2088
2089 skb->dev = dev;
2090
2091 if (dev_has_header(dev)) {
2092 /* The device has an explicit notion of ll header,
2093 * exported to higher levels.
2094 *
2095 * Otherwise, the device hides details of its frame
2096 * structure, so that corresponding packet head is
2097 * never delivered to user.
2098 */
2099 if (sk->sk_type != SOCK_DGRAM)
2100 skb_push(skb, skb->data - skb_mac_header(skb));
2101 else if (skb->pkt_type == PACKET_OUTGOING) {
2102 /* Special case: outgoing packets have ll header at head */
2103 skb_pull(skb, skb_network_offset(skb));
2104 }
2105 }
2106
2107 snaplen = skb->len;
2108
2109 res = run_filter(skb, sk, snaplen);
2110 if (!res)
2111 goto drop_n_restore;
2112 if (snaplen > res)
2113 snaplen = res;
2114
2115 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2116 goto drop_n_acct;
2117
2118 if (skb_shared(skb)) {
2119 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2120 if (nskb == NULL)
2121 goto drop_n_acct;
2122
2123 if (skb_head != skb->data) {
2124 skb->data = skb_head;
2125 skb->len = skb_len;
2126 }
2127 consume_skb(skb);
2128 skb = nskb;
2129 }
2130
2131 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2132
2133 sll = &PACKET_SKB_CB(skb)->sa.ll;
2134 sll->sll_hatype = dev->type;
2135 sll->sll_pkttype = skb->pkt_type;
2136 if (unlikely(po->origdev))
2137 sll->sll_ifindex = orig_dev->ifindex;
2138 else
2139 sll->sll_ifindex = dev->ifindex;
2140
2141 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2142
2143 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2144 * Use their space for storing the original skb length.
2145 */
2146 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2147
2148 if (pskb_trim(skb, snaplen))
2149 goto drop_n_acct;
2150
2151 skb_set_owner_r(skb, sk);
2152 skb->dev = NULL;
2153 skb_dst_drop(skb);
2154
2155 /* drop conntrack reference */
2156 nf_reset_ct(skb);
2157
2158 spin_lock(&sk->sk_receive_queue.lock);
2159 po->stats.stats1.tp_packets++;
2160 sock_skb_set_dropcount(sk, skb);
2161 __skb_queue_tail(&sk->sk_receive_queue, skb);
2162 spin_unlock(&sk->sk_receive_queue.lock);
2163 sk->sk_data_ready(sk);
2164 return 0;
2165
2166drop_n_acct:
2167 is_drop_n_account = true;
2168 atomic_inc(&po->tp_drops);
2169 atomic_inc(&sk->sk_drops);
2170
2171drop_n_restore:
2172 if (skb_head != skb->data && skb_shared(skb)) {
2173 skb->data = skb_head;
2174 skb->len = skb_len;
2175 }
2176drop:
2177 if (!is_drop_n_account)
2178 consume_skb(skb);
2179 else
2180 kfree_skb(skb);
2181 return 0;
2182}
2183
2184static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2185 struct packet_type *pt, struct net_device *orig_dev)
2186{
2187 struct sock *sk;
2188 struct packet_sock *po;
2189 struct sockaddr_ll *sll;
2190 union tpacket_uhdr h;
2191 u8 *skb_head = skb->data;
2192 int skb_len = skb->len;
2193 unsigned int snaplen, res;
2194 unsigned long status = TP_STATUS_USER;
2195 unsigned short macoff, hdrlen;
2196 unsigned int netoff;
2197 struct sk_buff *copy_skb = NULL;
2198 struct timespec64 ts;
2199 __u32 ts_status;
2200 bool is_drop_n_account = false;
2201 unsigned int slot_id = 0;
2202 bool do_vnet = false;
2203
2204 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2205 * We may add members to them until current aligned size without forcing
2206 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2207 */
2208 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2209 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2210
2211 if (skb->pkt_type == PACKET_LOOPBACK)
2212 goto drop;
2213
2214 sk = pt->af_packet_priv;
2215 po = pkt_sk(sk);
2216
2217 if (!net_eq(dev_net(dev), sock_net(sk)))
2218 goto drop;
2219
2220 if (dev_has_header(dev)) {
2221 if (sk->sk_type != SOCK_DGRAM)
2222 skb_push(skb, skb->data - skb_mac_header(skb));
2223 else if (skb->pkt_type == PACKET_OUTGOING) {
2224 /* Special case: outgoing packets have ll header at head */
2225 skb_pull(skb, skb_network_offset(skb));
2226 }
2227 }
2228
2229 snaplen = skb->len;
2230
2231 res = run_filter(skb, sk, snaplen);
2232 if (!res)
2233 goto drop_n_restore;
2234
2235 /* If we are flooded, just give up */
2236 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2237 atomic_inc(&po->tp_drops);
2238 goto drop_n_restore;
2239 }
2240
2241 if (skb->ip_summed == CHECKSUM_PARTIAL)
2242 status |= TP_STATUS_CSUMNOTREADY;
2243 else if (skb->pkt_type != PACKET_OUTGOING &&
2244 (skb->ip_summed == CHECKSUM_COMPLETE ||
2245 skb_csum_unnecessary(skb)))
2246 status |= TP_STATUS_CSUM_VALID;
2247
2248 if (snaplen > res)
2249 snaplen = res;
2250
2251 if (sk->sk_type == SOCK_DGRAM) {
2252 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2253 po->tp_reserve;
2254 } else {
2255 unsigned int maclen = skb_network_offset(skb);
2256 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2257 (maclen < 16 ? 16 : maclen)) +
2258 po->tp_reserve;
2259 if (po->has_vnet_hdr) {
2260 netoff += sizeof(struct virtio_net_hdr);
2261 do_vnet = true;
2262 }
2263 macoff = netoff - maclen;
2264 }
2265 if (netoff > USHRT_MAX) {
2266 atomic_inc(&po->tp_drops);
2267 goto drop_n_restore;
2268 }
2269 if (po->tp_version <= TPACKET_V2) {
2270 if (macoff + snaplen > po->rx_ring.frame_size) {
2271 if (po->copy_thresh &&
2272 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2273 if (skb_shared(skb)) {
2274 copy_skb = skb_clone(skb, GFP_ATOMIC);
2275 } else {
2276 copy_skb = skb_get(skb);
2277 skb_head = skb->data;
2278 }
2279 if (copy_skb)
2280 skb_set_owner_r(copy_skb, sk);
2281 }
2282 snaplen = po->rx_ring.frame_size - macoff;
2283 if ((int)snaplen < 0) {
2284 snaplen = 0;
2285 do_vnet = false;
2286 }
2287 }
2288 } else if (unlikely(macoff + snaplen >
2289 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2290 u32 nval;
2291
2292 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2293 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2294 snaplen, nval, macoff);
2295 snaplen = nval;
2296 if (unlikely((int)snaplen < 0)) {
2297 snaplen = 0;
2298 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2299 do_vnet = false;
2300 }
2301 }
2302 spin_lock(&sk->sk_receive_queue.lock);
2303 h.raw = packet_current_rx_frame(po, skb,
2304 TP_STATUS_KERNEL, (macoff+snaplen));
2305 if (!h.raw)
2306 goto drop_n_account;
2307
2308 if (po->tp_version <= TPACKET_V2) {
2309 slot_id = po->rx_ring.head;
2310 if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2311 goto drop_n_account;
2312 __set_bit(slot_id, po->rx_ring.rx_owner_map);
2313 }
2314
2315 if (do_vnet &&
2316 virtio_net_hdr_from_skb(skb, h.raw + macoff -
2317 sizeof(struct virtio_net_hdr),
2318 vio_le(), true, 0)) {
2319 if (po->tp_version == TPACKET_V3)
2320 prb_clear_blk_fill_status(&po->rx_ring);
2321 goto drop_n_account;
2322 }
2323
2324 if (po->tp_version <= TPACKET_V2) {
2325 packet_increment_rx_head(po, &po->rx_ring);
2326 /*
2327 * LOSING will be reported till you read the stats,
2328 * because it's COR - Clear On Read.
2329 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2330 * at packet level.
2331 */
2332 if (atomic_read(&po->tp_drops))
2333 status |= TP_STATUS_LOSING;
2334 }
2335
2336 po->stats.stats1.tp_packets++;
2337 if (copy_skb) {
2338 status |= TP_STATUS_COPY;
2339 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2340 }
2341 spin_unlock(&sk->sk_receive_queue.lock);
2342
2343 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2344
2345 /* Always timestamp; prefer an existing software timestamp taken
2346 * closer to the time of capture.
2347 */
2348 ts_status = tpacket_get_timestamp(skb, &ts,
2349 po->tp_tstamp | SOF_TIMESTAMPING_SOFTWARE);
2350 if (!ts_status)
2351 ktime_get_real_ts64(&ts);
2352
2353 status |= ts_status;
2354
2355 switch (po->tp_version) {
2356 case TPACKET_V1:
2357 h.h1->tp_len = skb->len;
2358 h.h1->tp_snaplen = snaplen;
2359 h.h1->tp_mac = macoff;
2360 h.h1->tp_net = netoff;
2361 h.h1->tp_sec = ts.tv_sec;
2362 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2363 hdrlen = sizeof(*h.h1);
2364 break;
2365 case TPACKET_V2:
2366 h.h2->tp_len = skb->len;
2367 h.h2->tp_snaplen = snaplen;
2368 h.h2->tp_mac = macoff;
2369 h.h2->tp_net = netoff;
2370 h.h2->tp_sec = ts.tv_sec;
2371 h.h2->tp_nsec = ts.tv_nsec;
2372 if (skb_vlan_tag_present(skb)) {
2373 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2374 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2375 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2376 } else {
2377 h.h2->tp_vlan_tci = 0;
2378 h.h2->tp_vlan_tpid = 0;
2379 }
2380 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2381 hdrlen = sizeof(*h.h2);
2382 break;
2383 case TPACKET_V3:
2384 /* tp_nxt_offset,vlan are already populated above.
2385 * So DONT clear those fields here
2386 */
2387 h.h3->tp_status |= status;
2388 h.h3->tp_len = skb->len;
2389 h.h3->tp_snaplen = snaplen;
2390 h.h3->tp_mac = macoff;
2391 h.h3->tp_net = netoff;
2392 h.h3->tp_sec = ts.tv_sec;
2393 h.h3->tp_nsec = ts.tv_nsec;
2394 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2395 hdrlen = sizeof(*h.h3);
2396 break;
2397 default:
2398 BUG();
2399 }
2400
2401 sll = h.raw + TPACKET_ALIGN(hdrlen);
2402 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2403 sll->sll_family = AF_PACKET;
2404 sll->sll_hatype = dev->type;
2405 sll->sll_protocol = skb->protocol;
2406 sll->sll_pkttype = skb->pkt_type;
2407 if (unlikely(po->origdev))
2408 sll->sll_ifindex = orig_dev->ifindex;
2409 else
2410 sll->sll_ifindex = dev->ifindex;
2411
2412 smp_mb();
2413
2414#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2415 if (po->tp_version <= TPACKET_V2) {
2416 u8 *start, *end;
2417
2418 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2419 macoff + snaplen);
2420
2421 for (start = h.raw; start < end; start += PAGE_SIZE)
2422 flush_dcache_page(pgv_to_page(start));
2423 }
2424 smp_wmb();
2425#endif
2426
2427 if (po->tp_version <= TPACKET_V2) {
2428 spin_lock(&sk->sk_receive_queue.lock);
2429 __packet_set_status(po, h.raw, status);
2430 __clear_bit(slot_id, po->rx_ring.rx_owner_map);
2431 spin_unlock(&sk->sk_receive_queue.lock);
2432 sk->sk_data_ready(sk);
2433 } else if (po->tp_version == TPACKET_V3) {
2434 prb_clear_blk_fill_status(&po->rx_ring);
2435 }
2436
2437drop_n_restore:
2438 if (skb_head != skb->data && skb_shared(skb)) {
2439 skb->data = skb_head;
2440 skb->len = skb_len;
2441 }
2442drop:
2443 if (!is_drop_n_account)
2444 consume_skb(skb);
2445 else
2446 kfree_skb(skb);
2447 return 0;
2448
2449drop_n_account:
2450 spin_unlock(&sk->sk_receive_queue.lock);
2451 atomic_inc(&po->tp_drops);
2452 is_drop_n_account = true;
2453
2454 sk->sk_data_ready(sk);
2455 kfree_skb(copy_skb);
2456 goto drop_n_restore;
2457}
2458
2459static void tpacket_destruct_skb(struct sk_buff *skb)
2460{
2461 struct packet_sock *po = pkt_sk(skb->sk);
2462
2463 if (likely(po->tx_ring.pg_vec)) {
2464 void *ph;
2465 __u32 ts;
2466
2467 ph = skb_zcopy_get_nouarg(skb);
2468 packet_dec_pending(&po->tx_ring);
2469
2470 ts = __packet_set_timestamp(po, ph, skb);
2471 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2472
2473 if (!packet_read_pending(&po->tx_ring))
2474 complete(&po->skb_completion);
2475 }
2476
2477 sock_wfree(skb);
2478}
2479
2480static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2481{
2482 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2483 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2484 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2485 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2486 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2487 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2488 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2489
2490 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2491 return -EINVAL;
2492
2493 return 0;
2494}
2495
2496static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2497 struct virtio_net_hdr *vnet_hdr)
2498{
2499 if (*len < sizeof(*vnet_hdr))
2500 return -EINVAL;
2501 *len -= sizeof(*vnet_hdr);
2502
2503 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2504 return -EFAULT;
2505
2506 return __packet_snd_vnet_parse(vnet_hdr, *len);
2507}
2508
2509static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2510 void *frame, struct net_device *dev, void *data, int tp_len,
2511 __be16 proto, unsigned char *addr, int hlen, int copylen,
2512 const struct sockcm_cookie *sockc)
2513{
2514 union tpacket_uhdr ph;
2515 int to_write, offset, len, nr_frags, len_max;
2516 struct socket *sock = po->sk.sk_socket;
2517 struct page *page;
2518 int err;
2519
2520 ph.raw = frame;
2521
2522 skb->protocol = proto;
2523 skb->dev = dev;
2524 skb->priority = po->sk.sk_priority;
2525 skb->mark = po->sk.sk_mark;
2526 skb->tstamp = sockc->transmit_time;
2527 skb_setup_tx_timestamp(skb, sockc->tsflags);
2528 skb_zcopy_set_nouarg(skb, ph.raw);
2529
2530 skb_reserve(skb, hlen);
2531 skb_reset_network_header(skb);
2532
2533 to_write = tp_len;
2534
2535 if (sock->type == SOCK_DGRAM) {
2536 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2537 NULL, tp_len);
2538 if (unlikely(err < 0))
2539 return -EINVAL;
2540 } else if (copylen) {
2541 int hdrlen = min_t(int, copylen, tp_len);
2542
2543 skb_push(skb, dev->hard_header_len);
2544 skb_put(skb, copylen - dev->hard_header_len);
2545 err = skb_store_bits(skb, 0, data, hdrlen);
2546 if (unlikely(err))
2547 return err;
2548 if (!dev_validate_header(dev, skb->data, hdrlen))
2549 return -EINVAL;
2550
2551 data += hdrlen;
2552 to_write -= hdrlen;
2553 }
2554
2555 offset = offset_in_page(data);
2556 len_max = PAGE_SIZE - offset;
2557 len = ((to_write > len_max) ? len_max : to_write);
2558
2559 skb->data_len = to_write;
2560 skb->len += to_write;
2561 skb->truesize += to_write;
2562 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2563
2564 while (likely(to_write)) {
2565 nr_frags = skb_shinfo(skb)->nr_frags;
2566
2567 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2568 pr_err("Packet exceed the number of skb frags(%lu)\n",
2569 MAX_SKB_FRAGS);
2570 return -EFAULT;
2571 }
2572
2573 page = pgv_to_page(data);
2574 data += len;
2575 flush_dcache_page(page);
2576 get_page(page);
2577 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2578 to_write -= len;
2579 offset = 0;
2580 len_max = PAGE_SIZE;
2581 len = ((to_write > len_max) ? len_max : to_write);
2582 }
2583
2584 packet_parse_headers(skb, sock);
2585
2586 return tp_len;
2587}
2588
2589static int tpacket_parse_header(struct packet_sock *po, void *frame,
2590 int size_max, void **data)
2591{
2592 union tpacket_uhdr ph;
2593 int tp_len, off;
2594
2595 ph.raw = frame;
2596
2597 switch (po->tp_version) {
2598 case TPACKET_V3:
2599 if (ph.h3->tp_next_offset != 0) {
2600 pr_warn_once("variable sized slot not supported");
2601 return -EINVAL;
2602 }
2603 tp_len = ph.h3->tp_len;
2604 break;
2605 case TPACKET_V2:
2606 tp_len = ph.h2->tp_len;
2607 break;
2608 default:
2609 tp_len = ph.h1->tp_len;
2610 break;
2611 }
2612 if (unlikely(tp_len > size_max)) {
2613 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2614 return -EMSGSIZE;
2615 }
2616
2617 if (unlikely(po->tp_tx_has_off)) {
2618 int off_min, off_max;
2619
2620 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2621 off_max = po->tx_ring.frame_size - tp_len;
2622 if (po->sk.sk_type == SOCK_DGRAM) {
2623 switch (po->tp_version) {
2624 case TPACKET_V3:
2625 off = ph.h3->tp_net;
2626 break;
2627 case TPACKET_V2:
2628 off = ph.h2->tp_net;
2629 break;
2630 default:
2631 off = ph.h1->tp_net;
2632 break;
2633 }
2634 } else {
2635 switch (po->tp_version) {
2636 case TPACKET_V3:
2637 off = ph.h3->tp_mac;
2638 break;
2639 case TPACKET_V2:
2640 off = ph.h2->tp_mac;
2641 break;
2642 default:
2643 off = ph.h1->tp_mac;
2644 break;
2645 }
2646 }
2647 if (unlikely((off < off_min) || (off_max < off)))
2648 return -EINVAL;
2649 } else {
2650 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2651 }
2652
2653 *data = frame + off;
2654 return tp_len;
2655}
2656
2657static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2658{
2659 struct sk_buff *skb = NULL;
2660 struct net_device *dev;
2661 struct virtio_net_hdr *vnet_hdr = NULL;
2662 struct sockcm_cookie sockc;
2663 __be16 proto;
2664 int err, reserve = 0;
2665 void *ph;
2666 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2667 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2668 unsigned char *addr = NULL;
2669 int tp_len, size_max;
2670 void *data;
2671 int len_sum = 0;
2672 int status = TP_STATUS_AVAILABLE;
2673 int hlen, tlen, copylen = 0;
2674 long timeo = 0;
2675
2676 mutex_lock(&po->pg_vec_lock);
2677
2678 /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2679 * we need to confirm it under protection of pg_vec_lock.
2680 */
2681 if (unlikely(!po->tx_ring.pg_vec)) {
2682 err = -EBUSY;
2683 goto out;
2684 }
2685 if (likely(saddr == NULL)) {
2686 dev = packet_cached_dev_get(po);
2687 proto = READ_ONCE(po->num);
2688 } else {
2689 err = -EINVAL;
2690 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2691 goto out;
2692 if (msg->msg_namelen < (saddr->sll_halen
2693 + offsetof(struct sockaddr_ll,
2694 sll_addr)))
2695 goto out;
2696 proto = saddr->sll_protocol;
2697 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2698 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2699 if (dev && msg->msg_namelen < dev->addr_len +
2700 offsetof(struct sockaddr_ll, sll_addr))
2701 goto out_put;
2702 addr = saddr->sll_addr;
2703 }
2704 }
2705
2706 err = -ENXIO;
2707 if (unlikely(dev == NULL))
2708 goto out;
2709 err = -ENETDOWN;
2710 if (unlikely(!(dev->flags & IFF_UP)))
2711 goto out_put;
2712
2713 sockcm_init(&sockc, &po->sk);
2714 if (msg->msg_controllen) {
2715 err = sock_cmsg_send(&po->sk, msg, &sockc);
2716 if (unlikely(err))
2717 goto out_put;
2718 }
2719
2720 if (po->sk.sk_socket->type == SOCK_RAW)
2721 reserve = dev->hard_header_len;
2722 size_max = po->tx_ring.frame_size
2723 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2724
2725 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2726 size_max = dev->mtu + reserve + VLAN_HLEN;
2727
2728 reinit_completion(&po->skb_completion);
2729
2730 do {
2731 ph = packet_current_frame(po, &po->tx_ring,
2732 TP_STATUS_SEND_REQUEST);
2733 if (unlikely(ph == NULL)) {
2734 if (need_wait && skb) {
2735 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2736 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2737 if (timeo <= 0) {
2738 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2739 goto out_put;
2740 }
2741 }
2742 /* check for additional frames */
2743 continue;
2744 }
2745
2746 skb = NULL;
2747 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2748 if (tp_len < 0)
2749 goto tpacket_error;
2750
2751 status = TP_STATUS_SEND_REQUEST;
2752 hlen = LL_RESERVED_SPACE(dev);
2753 tlen = dev->needed_tailroom;
2754 if (po->has_vnet_hdr) {
2755 vnet_hdr = data;
2756 data += sizeof(*vnet_hdr);
2757 tp_len -= sizeof(*vnet_hdr);
2758 if (tp_len < 0 ||
2759 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2760 tp_len = -EINVAL;
2761 goto tpacket_error;
2762 }
2763 copylen = __virtio16_to_cpu(vio_le(),
2764 vnet_hdr->hdr_len);
2765 }
2766 copylen = max_t(int, copylen, dev->hard_header_len);
2767 skb = sock_alloc_send_skb(&po->sk,
2768 hlen + tlen + sizeof(struct sockaddr_ll) +
2769 (copylen - dev->hard_header_len),
2770 !need_wait, &err);
2771
2772 if (unlikely(skb == NULL)) {
2773 /* we assume the socket was initially writeable ... */
2774 if (likely(len_sum > 0))
2775 err = len_sum;
2776 goto out_status;
2777 }
2778 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2779 addr, hlen, copylen, &sockc);
2780 if (likely(tp_len >= 0) &&
2781 tp_len > dev->mtu + reserve &&
2782 !po->has_vnet_hdr &&
2783 !packet_extra_vlan_len_allowed(dev, skb))
2784 tp_len = -EMSGSIZE;
2785
2786 if (unlikely(tp_len < 0)) {
2787tpacket_error:
2788 if (po->tp_loss) {
2789 __packet_set_status(po, ph,
2790 TP_STATUS_AVAILABLE);
2791 packet_increment_head(&po->tx_ring);
2792 kfree_skb(skb);
2793 continue;
2794 } else {
2795 status = TP_STATUS_WRONG_FORMAT;
2796 err = tp_len;
2797 goto out_status;
2798 }
2799 }
2800
2801 if (po->has_vnet_hdr) {
2802 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2803 tp_len = -EINVAL;
2804 goto tpacket_error;
2805 }
2806 virtio_net_hdr_set_proto(skb, vnet_hdr);
2807 }
2808
2809 skb->destructor = tpacket_destruct_skb;
2810 __packet_set_status(po, ph, TP_STATUS_SENDING);
2811 packet_inc_pending(&po->tx_ring);
2812
2813 status = TP_STATUS_SEND_REQUEST;
2814 err = po->xmit(skb);
2815 if (unlikely(err > 0)) {
2816 err = net_xmit_errno(err);
2817 if (err && __packet_get_status(po, ph) ==
2818 TP_STATUS_AVAILABLE) {
2819 /* skb was destructed already */
2820 skb = NULL;
2821 goto out_status;
2822 }
2823 /*
2824 * skb was dropped but not destructed yet;
2825 * let's treat it like congestion or err < 0
2826 */
2827 err = 0;
2828 }
2829 packet_increment_head(&po->tx_ring);
2830 len_sum += tp_len;
2831 } while (likely((ph != NULL) ||
2832 /* Note: packet_read_pending() might be slow if we have
2833 * to call it as it's per_cpu variable, but in fast-path
2834 * we already short-circuit the loop with the first
2835 * condition, and luckily don't have to go that path
2836 * anyway.
2837 */
2838 (need_wait && packet_read_pending(&po->tx_ring))));
2839
2840 err = len_sum;
2841 goto out_put;
2842
2843out_status:
2844 __packet_set_status(po, ph, status);
2845 kfree_skb(skb);
2846out_put:
2847 dev_put(dev);
2848out:
2849 mutex_unlock(&po->pg_vec_lock);
2850 return err;
2851}
2852
2853static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2854 size_t reserve, size_t len,
2855 size_t linear, int noblock,
2856 int *err)
2857{
2858 struct sk_buff *skb;
2859
2860 /* Under a page? Don't bother with paged skb. */
2861 if (prepad + len < PAGE_SIZE || !linear)
2862 linear = len;
2863
2864 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2865 err, 0);
2866 if (!skb)
2867 return NULL;
2868
2869 skb_reserve(skb, reserve);
2870 skb_put(skb, linear);
2871 skb->data_len = len - linear;
2872 skb->len += len - linear;
2873
2874 return skb;
2875}
2876
2877static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2878{
2879 struct sock *sk = sock->sk;
2880 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2881 struct sk_buff *skb;
2882 struct net_device *dev;
2883 __be16 proto;
2884 unsigned char *addr = NULL;
2885 int err, reserve = 0;
2886 struct sockcm_cookie sockc;
2887 struct virtio_net_hdr vnet_hdr = { 0 };
2888 int offset = 0;
2889 struct packet_sock *po = pkt_sk(sk);
2890 bool has_vnet_hdr = false;
2891 int hlen, tlen, linear;
2892 int extra_len = 0;
2893
2894 /*
2895 * Get and verify the address.
2896 */
2897
2898 if (likely(saddr == NULL)) {
2899 dev = packet_cached_dev_get(po);
2900 proto = READ_ONCE(po->num);
2901 } else {
2902 err = -EINVAL;
2903 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2904 goto out;
2905 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2906 goto out;
2907 proto = saddr->sll_protocol;
2908 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2909 if (sock->type == SOCK_DGRAM) {
2910 if (dev && msg->msg_namelen < dev->addr_len +
2911 offsetof(struct sockaddr_ll, sll_addr))
2912 goto out_unlock;
2913 addr = saddr->sll_addr;
2914 }
2915 }
2916
2917 err = -ENXIO;
2918 if (unlikely(dev == NULL))
2919 goto out_unlock;
2920 err = -ENETDOWN;
2921 if (unlikely(!(dev->flags & IFF_UP)))
2922 goto out_unlock;
2923
2924 sockcm_init(&sockc, sk);
2925 sockc.mark = sk->sk_mark;
2926 if (msg->msg_controllen) {
2927 err = sock_cmsg_send(sk, msg, &sockc);
2928 if (unlikely(err))
2929 goto out_unlock;
2930 }
2931
2932 if (sock->type == SOCK_RAW)
2933 reserve = dev->hard_header_len;
2934 if (po->has_vnet_hdr) {
2935 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2936 if (err)
2937 goto out_unlock;
2938 has_vnet_hdr = true;
2939 }
2940
2941 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2942 if (!netif_supports_nofcs(dev)) {
2943 err = -EPROTONOSUPPORT;
2944 goto out_unlock;
2945 }
2946 extra_len = 4; /* We're doing our own CRC */
2947 }
2948
2949 err = -EMSGSIZE;
2950 if (!vnet_hdr.gso_type &&
2951 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2952 goto out_unlock;
2953
2954 err = -ENOBUFS;
2955 hlen = LL_RESERVED_SPACE(dev);
2956 tlen = dev->needed_tailroom;
2957 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2958 linear = max(linear, min_t(int, len, dev->hard_header_len));
2959 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2960 msg->msg_flags & MSG_DONTWAIT, &err);
2961 if (skb == NULL)
2962 goto out_unlock;
2963
2964 skb_reset_network_header(skb);
2965
2966 err = -EINVAL;
2967 if (sock->type == SOCK_DGRAM) {
2968 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2969 if (unlikely(offset < 0))
2970 goto out_free;
2971 } else if (reserve) {
2972 skb_reserve(skb, -reserve);
2973 if (len < reserve + sizeof(struct ipv6hdr) &&
2974 dev->min_header_len != dev->hard_header_len)
2975 skb_reset_network_header(skb);
2976 }
2977
2978 /* Returns -EFAULT on error */
2979 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2980 if (err)
2981 goto out_free;
2982
2983 if (sock->type == SOCK_RAW &&
2984 !dev_validate_header(dev, skb->data, len)) {
2985 err = -EINVAL;
2986 goto out_free;
2987 }
2988
2989 skb_setup_tx_timestamp(skb, sockc.tsflags);
2990
2991 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2992 !packet_extra_vlan_len_allowed(dev, skb)) {
2993 err = -EMSGSIZE;
2994 goto out_free;
2995 }
2996
2997 skb->protocol = proto;
2998 skb->dev = dev;
2999 skb->priority = sk->sk_priority;
3000 skb->mark = sockc.mark;
3001 skb->tstamp = sockc.transmit_time;
3002
3003 if (has_vnet_hdr) {
3004 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
3005 if (err)
3006 goto out_free;
3007 len += sizeof(vnet_hdr);
3008 virtio_net_hdr_set_proto(skb, &vnet_hdr);
3009 }
3010
3011 packet_parse_headers(skb, sock);
3012
3013 if (unlikely(extra_len == 4))
3014 skb->no_fcs = 1;
3015
3016 err = po->xmit(skb);
3017 if (err > 0 && (err = net_xmit_errno(err)) != 0)
3018 goto out_unlock;
3019
3020 dev_put(dev);
3021
3022 return len;
3023
3024out_free:
3025 kfree_skb(skb);
3026out_unlock:
3027 if (dev)
3028 dev_put(dev);
3029out:
3030 return err;
3031}
3032
3033static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3034{
3035 struct sock *sk = sock->sk;
3036 struct packet_sock *po = pkt_sk(sk);
3037
3038 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
3039 * tpacket_snd() will redo the check safely.
3040 */
3041 if (data_race(po->tx_ring.pg_vec))
3042 return tpacket_snd(po, msg);
3043
3044 return packet_snd(sock, msg, len);
3045}
3046
3047/*
3048 * Close a PACKET socket. This is fairly simple. We immediately go
3049 * to 'closed' state and remove our protocol entry in the device list.
3050 */
3051
3052static int packet_release(struct socket *sock)
3053{
3054 struct sock *sk = sock->sk;
3055 struct packet_sock *po;
3056 struct packet_fanout *f;
3057 struct net *net;
3058 union tpacket_req_u req_u;
3059
3060 if (!sk)
3061 return 0;
3062
3063 net = sock_net(sk);
3064 po = pkt_sk(sk);
3065
3066 mutex_lock(&net->packet.sklist_lock);
3067 sk_del_node_init_rcu(sk);
3068 mutex_unlock(&net->packet.sklist_lock);
3069
3070 preempt_disable();
3071 sock_prot_inuse_add(net, sk->sk_prot, -1);
3072 preempt_enable();
3073
3074 spin_lock(&po->bind_lock);
3075 unregister_prot_hook(sk, false);
3076 packet_cached_dev_reset(po);
3077
3078 if (po->prot_hook.dev) {
3079 dev_put(po->prot_hook.dev);
3080 po->prot_hook.dev = NULL;
3081 }
3082 spin_unlock(&po->bind_lock);
3083
3084 packet_flush_mclist(sk);
3085
3086 lock_sock(sk);
3087 if (po->rx_ring.pg_vec) {
3088 memset(&req_u, 0, sizeof(req_u));
3089 packet_set_ring(sk, &req_u, 1, 0);
3090 }
3091
3092 if (po->tx_ring.pg_vec) {
3093 memset(&req_u, 0, sizeof(req_u));
3094 packet_set_ring(sk, &req_u, 1, 1);
3095 }
3096 release_sock(sk);
3097
3098 f = fanout_release(sk);
3099
3100 synchronize_net();
3101
3102 kfree(po->rollover);
3103 if (f) {
3104 fanout_release_data(f);
3105 kvfree(f);
3106 }
3107 /*
3108 * Now the socket is dead. No more input will appear.
3109 */
3110 sock_orphan(sk);
3111 sock->sk = NULL;
3112
3113 /* Purge queues */
3114
3115 skb_queue_purge(&sk->sk_receive_queue);
3116 packet_free_pending(po);
3117 sk_refcnt_debug_release(sk);
3118
3119 sock_put(sk);
3120 return 0;
3121}
3122
3123/*
3124 * Attach a packet hook.
3125 */
3126
3127static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3128 __be16 proto)
3129{
3130 struct packet_sock *po = pkt_sk(sk);
3131 struct net_device *dev_curr;
3132 __be16 proto_curr;
3133 bool need_rehook;
3134 struct net_device *dev = NULL;
3135 int ret = 0;
3136 bool unlisted = false;
3137
3138 lock_sock(sk);
3139 spin_lock(&po->bind_lock);
3140 rcu_read_lock();
3141
3142 if (po->fanout) {
3143 ret = -EINVAL;
3144 goto out_unlock;
3145 }
3146
3147 if (name) {
3148 dev = dev_get_by_name_rcu(sock_net(sk), name);
3149 if (!dev) {
3150 ret = -ENODEV;
3151 goto out_unlock;
3152 }
3153 } else if (ifindex) {
3154 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3155 if (!dev) {
3156 ret = -ENODEV;
3157 goto out_unlock;
3158 }
3159 }
3160
3161 if (dev)
3162 dev_hold(dev);
3163
3164 proto_curr = po->prot_hook.type;
3165 dev_curr = po->prot_hook.dev;
3166
3167 need_rehook = proto_curr != proto || dev_curr != dev;
3168
3169 if (need_rehook) {
3170 if (po->running) {
3171 rcu_read_unlock();
3172 /* prevents packet_notifier() from calling
3173 * register_prot_hook()
3174 */
3175 WRITE_ONCE(po->num, 0);
3176 __unregister_prot_hook(sk, true);
3177 rcu_read_lock();
3178 dev_curr = po->prot_hook.dev;
3179 if (dev)
3180 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3181 dev->ifindex);
3182 }
3183
3184 BUG_ON(po->running);
3185 WRITE_ONCE(po->num, proto);
3186 po->prot_hook.type = proto;
3187
3188 if (unlikely(unlisted)) {
3189 dev_put(dev);
3190 po->prot_hook.dev = NULL;
3191 WRITE_ONCE(po->ifindex, -1);
3192 packet_cached_dev_reset(po);
3193 } else {
3194 po->prot_hook.dev = dev;
3195 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
3196 packet_cached_dev_assign(po, dev);
3197 }
3198 }
3199 if (dev_curr)
3200 dev_put(dev_curr);
3201
3202 if (proto == 0 || !need_rehook)
3203 goto out_unlock;
3204
3205 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3206 register_prot_hook(sk);
3207 } else {
3208 sk->sk_err = ENETDOWN;
3209 if (!sock_flag(sk, SOCK_DEAD))
3210 sk_error_report(sk);
3211 }
3212
3213out_unlock:
3214 rcu_read_unlock();
3215 spin_unlock(&po->bind_lock);
3216 release_sock(sk);
3217 return ret;
3218}
3219
3220/*
3221 * Bind a packet socket to a device
3222 */
3223
3224static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3225 int addr_len)
3226{
3227 struct sock *sk = sock->sk;
3228 char name[sizeof(uaddr->sa_data) + 1];
3229
3230 /*
3231 * Check legality
3232 */
3233
3234 if (addr_len != sizeof(struct sockaddr))
3235 return -EINVAL;
3236 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3237 * zero-terminated.
3238 */
3239 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3240 name[sizeof(uaddr->sa_data)] = 0;
3241
3242 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3243}
3244
3245static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3246{
3247 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3248 struct sock *sk = sock->sk;
3249
3250 /*
3251 * Check legality
3252 */
3253
3254 if (addr_len < sizeof(struct sockaddr_ll))
3255 return -EINVAL;
3256 if (sll->sll_family != AF_PACKET)
3257 return -EINVAL;
3258
3259 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3260 sll->sll_protocol ? : pkt_sk(sk)->num);
3261}
3262
3263static struct proto packet_proto = {
3264 .name = "PACKET",
3265 .owner = THIS_MODULE,
3266 .obj_size = sizeof(struct packet_sock),
3267};
3268
3269/*
3270 * Create a packet of type SOCK_PACKET.
3271 */
3272
3273static int packet_create(struct net *net, struct socket *sock, int protocol,
3274 int kern)
3275{
3276 struct sock *sk;
3277 struct packet_sock *po;
3278 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3279 int err;
3280
3281 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3282 return -EPERM;
3283 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3284 sock->type != SOCK_PACKET)
3285 return -ESOCKTNOSUPPORT;
3286
3287 sock->state = SS_UNCONNECTED;
3288
3289 err = -ENOBUFS;
3290 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3291 if (sk == NULL)
3292 goto out;
3293
3294 sock->ops = &packet_ops;
3295 if (sock->type == SOCK_PACKET)
3296 sock->ops = &packet_ops_spkt;
3297
3298 sock_init_data(sock, sk);
3299
3300 po = pkt_sk(sk);
3301 init_completion(&po->skb_completion);
3302 sk->sk_family = PF_PACKET;
3303 po->num = proto;
3304 po->xmit = dev_queue_xmit;
3305
3306 err = packet_alloc_pending(po);
3307 if (err)
3308 goto out2;
3309
3310 packet_cached_dev_reset(po);
3311
3312 sk->sk_destruct = packet_sock_destruct;
3313 sk_refcnt_debug_inc(sk);
3314
3315 /*
3316 * Attach a protocol block
3317 */
3318
3319 spin_lock_init(&po->bind_lock);
3320 mutex_init(&po->pg_vec_lock);
3321 po->rollover = NULL;
3322 po->prot_hook.func = packet_rcv;
3323
3324 if (sock->type == SOCK_PACKET)
3325 po->prot_hook.func = packet_rcv_spkt;
3326
3327 po->prot_hook.af_packet_priv = sk;
3328
3329 if (proto) {
3330 po->prot_hook.type = proto;
3331 __register_prot_hook(sk);
3332 }
3333
3334 mutex_lock(&net->packet.sklist_lock);
3335 sk_add_node_tail_rcu(sk, &net->packet.sklist);
3336 mutex_unlock(&net->packet.sklist_lock);
3337
3338 preempt_disable();
3339 sock_prot_inuse_add(net, &packet_proto, 1);
3340 preempt_enable();
3341
3342 return 0;
3343out2:
3344 sk_free(sk);
3345out:
3346 return err;
3347}
3348
3349/*
3350 * Pull a packet from our receive queue and hand it to the user.
3351 * If necessary we block.
3352 */
3353
3354static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3355 int flags)
3356{
3357 struct sock *sk = sock->sk;
3358 struct sk_buff *skb;
3359 int copied, err;
3360 int vnet_hdr_len = 0;
3361 unsigned int origlen = 0;
3362
3363 err = -EINVAL;
3364 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3365 goto out;
3366
3367#if 0
3368 /* What error should we return now? EUNATTACH? */
3369 if (pkt_sk(sk)->ifindex < 0)
3370 return -ENODEV;
3371#endif
3372
3373 if (flags & MSG_ERRQUEUE) {
3374 err = sock_recv_errqueue(sk, msg, len,
3375 SOL_PACKET, PACKET_TX_TIMESTAMP);
3376 goto out;
3377 }
3378
3379 /*
3380 * Call the generic datagram receiver. This handles all sorts
3381 * of horrible races and re-entrancy so we can forget about it
3382 * in the protocol layers.
3383 *
3384 * Now it will return ENETDOWN, if device have just gone down,
3385 * but then it will block.
3386 */
3387
3388 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3389
3390 /*
3391 * An error occurred so return it. Because skb_recv_datagram()
3392 * handles the blocking we don't see and worry about blocking
3393 * retries.
3394 */
3395
3396 if (skb == NULL)
3397 goto out;
3398
3399 packet_rcv_try_clear_pressure(pkt_sk(sk));
3400
3401 if (pkt_sk(sk)->has_vnet_hdr) {
3402 err = packet_rcv_vnet(msg, skb, &len);
3403 if (err)
3404 goto out_free;
3405 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3406 }
3407
3408 /* You lose any data beyond the buffer you gave. If it worries
3409 * a user program they can ask the device for its MTU
3410 * anyway.
3411 */
3412 copied = skb->len;
3413 if (copied > len) {
3414 copied = len;
3415 msg->msg_flags |= MSG_TRUNC;
3416 }
3417
3418 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3419 if (err)
3420 goto out_free;
3421
3422 if (sock->type != SOCK_PACKET) {
3423 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3424
3425 /* Original length was stored in sockaddr_ll fields */
3426 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3427 sll->sll_family = AF_PACKET;
3428 sll->sll_protocol = skb->protocol;
3429 }
3430
3431 sock_recv_ts_and_drops(msg, sk, skb);
3432
3433 if (msg->msg_name) {
3434 int copy_len;
3435
3436 /* If the address length field is there to be filled
3437 * in, we fill it in now.
3438 */
3439 if (sock->type == SOCK_PACKET) {
3440 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3441 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3442 copy_len = msg->msg_namelen;
3443 } else {
3444 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3445
3446 msg->msg_namelen = sll->sll_halen +
3447 offsetof(struct sockaddr_ll, sll_addr);
3448 copy_len = msg->msg_namelen;
3449 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3450 memset(msg->msg_name +
3451 offsetof(struct sockaddr_ll, sll_addr),
3452 0, sizeof(sll->sll_addr));
3453 msg->msg_namelen = sizeof(struct sockaddr_ll);
3454 }
3455 }
3456 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3457 }
3458
3459 if (pkt_sk(sk)->auxdata) {
3460 struct tpacket_auxdata aux;
3461
3462 aux.tp_status = TP_STATUS_USER;
3463 if (skb->ip_summed == CHECKSUM_PARTIAL)
3464 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3465 else if (skb->pkt_type != PACKET_OUTGOING &&
3466 (skb->ip_summed == CHECKSUM_COMPLETE ||
3467 skb_csum_unnecessary(skb)))
3468 aux.tp_status |= TP_STATUS_CSUM_VALID;
3469
3470 aux.tp_len = origlen;
3471 aux.tp_snaplen = skb->len;
3472 aux.tp_mac = 0;
3473 aux.tp_net = skb_network_offset(skb);
3474 if (skb_vlan_tag_present(skb)) {
3475 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3476 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3477 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3478 } else {
3479 aux.tp_vlan_tci = 0;
3480 aux.tp_vlan_tpid = 0;
3481 }
3482 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3483 }
3484
3485 /*
3486 * Free or return the buffer as appropriate. Again this
3487 * hides all the races and re-entrancy issues from us.
3488 */
3489 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3490
3491out_free:
3492 skb_free_datagram(sk, skb);
3493out:
3494 return err;
3495}
3496
3497static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3498 int peer)
3499{
3500 struct net_device *dev;
3501 struct sock *sk = sock->sk;
3502
3503 if (peer)
3504 return -EOPNOTSUPP;
3505
3506 uaddr->sa_family = AF_PACKET;
3507 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3508 rcu_read_lock();
3509 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
3510 if (dev)
3511 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3512 rcu_read_unlock();
3513
3514 return sizeof(*uaddr);
3515}
3516
3517static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3518 int peer)
3519{
3520 struct net_device *dev;
3521 struct sock *sk = sock->sk;
3522 struct packet_sock *po = pkt_sk(sk);
3523 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3524 int ifindex;
3525
3526 if (peer)
3527 return -EOPNOTSUPP;
3528
3529 ifindex = READ_ONCE(po->ifindex);
3530 sll->sll_family = AF_PACKET;
3531 sll->sll_ifindex = ifindex;
3532 sll->sll_protocol = READ_ONCE(po->num);
3533 sll->sll_pkttype = 0;
3534 rcu_read_lock();
3535 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3536 if (dev) {
3537 sll->sll_hatype = dev->type;
3538 sll->sll_halen = dev->addr_len;
3539 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3540 } else {
3541 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3542 sll->sll_halen = 0;
3543 }
3544 rcu_read_unlock();
3545
3546 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3547}
3548
3549static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3550 int what)
3551{
3552 switch (i->type) {
3553 case PACKET_MR_MULTICAST:
3554 if (i->alen != dev->addr_len)
3555 return -EINVAL;
3556 if (what > 0)
3557 return dev_mc_add(dev, i->addr);
3558 else
3559 return dev_mc_del(dev, i->addr);
3560 break;
3561 case PACKET_MR_PROMISC:
3562 return dev_set_promiscuity(dev, what);
3563 case PACKET_MR_ALLMULTI:
3564 return dev_set_allmulti(dev, what);
3565 case PACKET_MR_UNICAST:
3566 if (i->alen != dev->addr_len)
3567 return -EINVAL;
3568 if (what > 0)
3569 return dev_uc_add(dev, i->addr);
3570 else
3571 return dev_uc_del(dev, i->addr);
3572 break;
3573 default:
3574 break;
3575 }
3576 return 0;
3577}
3578
3579static void packet_dev_mclist_delete(struct net_device *dev,
3580 struct packet_mclist **mlp)
3581{
3582 struct packet_mclist *ml;
3583
3584 while ((ml = *mlp) != NULL) {
3585 if (ml->ifindex == dev->ifindex) {
3586 packet_dev_mc(dev, ml, -1);
3587 *mlp = ml->next;
3588 kfree(ml);
3589 } else
3590 mlp = &ml->next;
3591 }
3592}
3593
3594static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3595{
3596 struct packet_sock *po = pkt_sk(sk);
3597 struct packet_mclist *ml, *i;
3598 struct net_device *dev;
3599 int err;
3600
3601 rtnl_lock();
3602
3603 err = -ENODEV;
3604 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3605 if (!dev)
3606 goto done;
3607
3608 err = -EINVAL;
3609 if (mreq->mr_alen > dev->addr_len)
3610 goto done;
3611
3612 err = -ENOBUFS;
3613 i = kmalloc(sizeof(*i), GFP_KERNEL);
3614 if (i == NULL)
3615 goto done;
3616
3617 err = 0;
3618 for (ml = po->mclist; ml; ml = ml->next) {
3619 if (ml->ifindex == mreq->mr_ifindex &&
3620 ml->type == mreq->mr_type &&
3621 ml->alen == mreq->mr_alen &&
3622 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3623 ml->count++;
3624 /* Free the new element ... */
3625 kfree(i);
3626 goto done;
3627 }
3628 }
3629
3630 i->type = mreq->mr_type;
3631 i->ifindex = mreq->mr_ifindex;
3632 i->alen = mreq->mr_alen;
3633 memcpy(i->addr, mreq->mr_address, i->alen);
3634 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3635 i->count = 1;
3636 i->next = po->mclist;
3637 po->mclist = i;
3638 err = packet_dev_mc(dev, i, 1);
3639 if (err) {
3640 po->mclist = i->next;
3641 kfree(i);
3642 }
3643
3644done:
3645 rtnl_unlock();
3646 return err;
3647}
3648
3649static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3650{
3651 struct packet_mclist *ml, **mlp;
3652
3653 rtnl_lock();
3654
3655 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3656 if (ml->ifindex == mreq->mr_ifindex &&
3657 ml->type == mreq->mr_type &&
3658 ml->alen == mreq->mr_alen &&
3659 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3660 if (--ml->count == 0) {
3661 struct net_device *dev;
3662 *mlp = ml->next;
3663 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3664 if (dev)
3665 packet_dev_mc(dev, ml, -1);
3666 kfree(ml);
3667 }
3668 break;
3669 }
3670 }
3671 rtnl_unlock();
3672 return 0;
3673}
3674
3675static void packet_flush_mclist(struct sock *sk)
3676{
3677 struct packet_sock *po = pkt_sk(sk);
3678 struct packet_mclist *ml;
3679
3680 if (!po->mclist)
3681 return;
3682
3683 rtnl_lock();
3684 while ((ml = po->mclist) != NULL) {
3685 struct net_device *dev;
3686
3687 po->mclist = ml->next;
3688 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3689 if (dev != NULL)
3690 packet_dev_mc(dev, ml, -1);
3691 kfree(ml);
3692 }
3693 rtnl_unlock();
3694}
3695
3696static int
3697packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3698 unsigned int optlen)
3699{
3700 struct sock *sk = sock->sk;
3701 struct packet_sock *po = pkt_sk(sk);
3702 int ret;
3703
3704 if (level != SOL_PACKET)
3705 return -ENOPROTOOPT;
3706
3707 switch (optname) {
3708 case PACKET_ADD_MEMBERSHIP:
3709 case PACKET_DROP_MEMBERSHIP:
3710 {
3711 struct packet_mreq_max mreq;
3712 int len = optlen;
3713 memset(&mreq, 0, sizeof(mreq));
3714 if (len < sizeof(struct packet_mreq))
3715 return -EINVAL;
3716 if (len > sizeof(mreq))
3717 len = sizeof(mreq);
3718 if (copy_from_sockptr(&mreq, optval, len))
3719 return -EFAULT;
3720 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3721 return -EINVAL;
3722 if (optname == PACKET_ADD_MEMBERSHIP)
3723 ret = packet_mc_add(sk, &mreq);
3724 else
3725 ret = packet_mc_drop(sk, &mreq);
3726 return ret;
3727 }
3728
3729 case PACKET_RX_RING:
3730 case PACKET_TX_RING:
3731 {
3732 union tpacket_req_u req_u;
3733 int len;
3734
3735 lock_sock(sk);
3736 switch (po->tp_version) {
3737 case TPACKET_V1:
3738 case TPACKET_V2:
3739 len = sizeof(req_u.req);
3740 break;
3741 case TPACKET_V3:
3742 default:
3743 len = sizeof(req_u.req3);
3744 break;
3745 }
3746 if (optlen < len) {
3747 ret = -EINVAL;
3748 } else {
3749 if (copy_from_sockptr(&req_u.req, optval, len))
3750 ret = -EFAULT;
3751 else
3752 ret = packet_set_ring(sk, &req_u, 0,
3753 optname == PACKET_TX_RING);
3754 }
3755 release_sock(sk);
3756 return ret;
3757 }
3758 case PACKET_COPY_THRESH:
3759 {
3760 int val;
3761
3762 if (optlen != sizeof(val))
3763 return -EINVAL;
3764 if (copy_from_sockptr(&val, optval, sizeof(val)))
3765 return -EFAULT;
3766
3767 pkt_sk(sk)->copy_thresh = val;
3768 return 0;
3769 }
3770 case PACKET_VERSION:
3771 {
3772 int val;
3773
3774 if (optlen != sizeof(val))
3775 return -EINVAL;
3776 if (copy_from_sockptr(&val, optval, sizeof(val)))
3777 return -EFAULT;
3778 switch (val) {
3779 case TPACKET_V1:
3780 case TPACKET_V2:
3781 case TPACKET_V3:
3782 break;
3783 default:
3784 return -EINVAL;
3785 }
3786 lock_sock(sk);
3787 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3788 ret = -EBUSY;
3789 } else {
3790 po->tp_version = val;
3791 ret = 0;
3792 }
3793 release_sock(sk);
3794 return ret;
3795 }
3796 case PACKET_RESERVE:
3797 {
3798 unsigned int val;
3799
3800 if (optlen != sizeof(val))
3801 return -EINVAL;
3802 if (copy_from_sockptr(&val, optval, sizeof(val)))
3803 return -EFAULT;
3804 if (val > INT_MAX)
3805 return -EINVAL;
3806 lock_sock(sk);
3807 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3808 ret = -EBUSY;
3809 } else {
3810 po->tp_reserve = val;
3811 ret = 0;
3812 }
3813 release_sock(sk);
3814 return ret;
3815 }
3816 case PACKET_LOSS:
3817 {
3818 unsigned int val;
3819
3820 if (optlen != sizeof(val))
3821 return -EINVAL;
3822 if (copy_from_sockptr(&val, optval, sizeof(val)))
3823 return -EFAULT;
3824
3825 lock_sock(sk);
3826 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3827 ret = -EBUSY;
3828 } else {
3829 po->tp_loss = !!val;
3830 ret = 0;
3831 }
3832 release_sock(sk);
3833 return ret;
3834 }
3835 case PACKET_AUXDATA:
3836 {
3837 int val;
3838
3839 if (optlen < sizeof(val))
3840 return -EINVAL;
3841 if (copy_from_sockptr(&val, optval, sizeof(val)))
3842 return -EFAULT;
3843
3844 lock_sock(sk);
3845 po->auxdata = !!val;
3846 release_sock(sk);
3847 return 0;
3848 }
3849 case PACKET_ORIGDEV:
3850 {
3851 int val;
3852
3853 if (optlen < sizeof(val))
3854 return -EINVAL;
3855 if (copy_from_sockptr(&val, optval, sizeof(val)))
3856 return -EFAULT;
3857
3858 lock_sock(sk);
3859 po->origdev = !!val;
3860 release_sock(sk);
3861 return 0;
3862 }
3863 case PACKET_VNET_HDR:
3864 {
3865 int val;
3866
3867 if (sock->type != SOCK_RAW)
3868 return -EINVAL;
3869 if (optlen < sizeof(val))
3870 return -EINVAL;
3871 if (copy_from_sockptr(&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->has_vnet_hdr = !!val;
3879 ret = 0;
3880 }
3881 release_sock(sk);
3882 return ret;
3883 }
3884 case PACKET_TIMESTAMP:
3885 {
3886 int val;
3887
3888 if (optlen != sizeof(val))
3889 return -EINVAL;
3890 if (copy_from_sockptr(&val, optval, sizeof(val)))
3891 return -EFAULT;
3892
3893 po->tp_tstamp = val;
3894 return 0;
3895 }
3896 case PACKET_FANOUT:
3897 {
3898 struct fanout_args args = { 0 };
3899
3900 if (optlen != sizeof(int) && optlen != sizeof(args))
3901 return -EINVAL;
3902 if (copy_from_sockptr(&args, optval, optlen))
3903 return -EFAULT;
3904
3905 return fanout_add(sk, &args);
3906 }
3907 case PACKET_FANOUT_DATA:
3908 {
3909 if (!po->fanout)
3910 return -EINVAL;
3911
3912 return fanout_set_data(po, optval, optlen);
3913 }
3914 case PACKET_IGNORE_OUTGOING:
3915 {
3916 int val;
3917
3918 if (optlen != sizeof(val))
3919 return -EINVAL;
3920 if (copy_from_sockptr(&val, optval, sizeof(val)))
3921 return -EFAULT;
3922 if (val < 0 || val > 1)
3923 return -EINVAL;
3924
3925 po->prot_hook.ignore_outgoing = !!val;
3926 return 0;
3927 }
3928 case PACKET_TX_HAS_OFF:
3929 {
3930 unsigned int val;
3931
3932 if (optlen != sizeof(val))
3933 return -EINVAL;
3934 if (copy_from_sockptr(&val, optval, sizeof(val)))
3935 return -EFAULT;
3936
3937 lock_sock(sk);
3938 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec)
3939 po->tp_tx_has_off = !!val;
3940
3941 release_sock(sk);
3942 return 0;
3943 }
3944 case PACKET_QDISC_BYPASS:
3945 {
3946 int val;
3947
3948 if (optlen != sizeof(val))
3949 return -EINVAL;
3950 if (copy_from_sockptr(&val, optval, sizeof(val)))
3951 return -EFAULT;
3952
3953 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3954 return 0;
3955 }
3956 default:
3957 return -ENOPROTOOPT;
3958 }
3959}
3960
3961static int packet_getsockopt(struct socket *sock, int level, int optname,
3962 char __user *optval, int __user *optlen)
3963{
3964 int len;
3965 int val, lv = sizeof(val);
3966 struct sock *sk = sock->sk;
3967 struct packet_sock *po = pkt_sk(sk);
3968 void *data = &val;
3969 union tpacket_stats_u st;
3970 struct tpacket_rollover_stats rstats;
3971 int drops;
3972
3973 if (level != SOL_PACKET)
3974 return -ENOPROTOOPT;
3975
3976 if (get_user(len, optlen))
3977 return -EFAULT;
3978
3979 if (len < 0)
3980 return -EINVAL;
3981
3982 switch (optname) {
3983 case PACKET_STATISTICS:
3984 spin_lock_bh(&sk->sk_receive_queue.lock);
3985 memcpy(&st, &po->stats, sizeof(st));
3986 memset(&po->stats, 0, sizeof(po->stats));
3987 spin_unlock_bh(&sk->sk_receive_queue.lock);
3988 drops = atomic_xchg(&po->tp_drops, 0);
3989
3990 if (po->tp_version == TPACKET_V3) {
3991 lv = sizeof(struct tpacket_stats_v3);
3992 st.stats3.tp_drops = drops;
3993 st.stats3.tp_packets += drops;
3994 data = &st.stats3;
3995 } else {
3996 lv = sizeof(struct tpacket_stats);
3997 st.stats1.tp_drops = drops;
3998 st.stats1.tp_packets += drops;
3999 data = &st.stats1;
4000 }
4001
4002 break;
4003 case PACKET_AUXDATA:
4004 val = po->auxdata;
4005 break;
4006 case PACKET_ORIGDEV:
4007 val = po->origdev;
4008 break;
4009 case PACKET_VNET_HDR:
4010 val = po->has_vnet_hdr;
4011 break;
4012 case PACKET_VERSION:
4013 val = po->tp_version;
4014 break;
4015 case PACKET_HDRLEN:
4016 if (len > sizeof(int))
4017 len = sizeof(int);
4018 if (len < sizeof(int))
4019 return -EINVAL;
4020 if (copy_from_user(&val, optval, len))
4021 return -EFAULT;
4022 switch (val) {
4023 case TPACKET_V1:
4024 val = sizeof(struct tpacket_hdr);
4025 break;
4026 case TPACKET_V2:
4027 val = sizeof(struct tpacket2_hdr);
4028 break;
4029 case TPACKET_V3:
4030 val = sizeof(struct tpacket3_hdr);
4031 break;
4032 default:
4033 return -EINVAL;
4034 }
4035 break;
4036 case PACKET_RESERVE:
4037 val = po->tp_reserve;
4038 break;
4039 case PACKET_LOSS:
4040 val = po->tp_loss;
4041 break;
4042 case PACKET_TIMESTAMP:
4043 val = po->tp_tstamp;
4044 break;
4045 case PACKET_FANOUT:
4046 val = (po->fanout ?
4047 ((u32)po->fanout->id |
4048 ((u32)po->fanout->type << 16) |
4049 ((u32)po->fanout->flags << 24)) :
4050 0);
4051 break;
4052 case PACKET_IGNORE_OUTGOING:
4053 val = po->prot_hook.ignore_outgoing;
4054 break;
4055 case PACKET_ROLLOVER_STATS:
4056 if (!po->rollover)
4057 return -EINVAL;
4058 rstats.tp_all = atomic_long_read(&po->rollover->num);
4059 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4060 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4061 data = &rstats;
4062 lv = sizeof(rstats);
4063 break;
4064 case PACKET_TX_HAS_OFF:
4065 val = po->tp_tx_has_off;
4066 break;
4067 case PACKET_QDISC_BYPASS:
4068 val = packet_use_direct_xmit(po);
4069 break;
4070 default:
4071 return -ENOPROTOOPT;
4072 }
4073
4074 if (len > lv)
4075 len = lv;
4076 if (put_user(len, optlen))
4077 return -EFAULT;
4078 if (copy_to_user(optval, data, len))
4079 return -EFAULT;
4080 return 0;
4081}
4082
4083static int packet_notifier(struct notifier_block *this,
4084 unsigned long msg, void *ptr)
4085{
4086 struct sock *sk;
4087 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4088 struct net *net = dev_net(dev);
4089
4090 rcu_read_lock();
4091 sk_for_each_rcu(sk, &net->packet.sklist) {
4092 struct packet_sock *po = pkt_sk(sk);
4093
4094 switch (msg) {
4095 case NETDEV_UNREGISTER:
4096 if (po->mclist)
4097 packet_dev_mclist_delete(dev, &po->mclist);
4098 fallthrough;
4099
4100 case NETDEV_DOWN:
4101 if (dev->ifindex == po->ifindex) {
4102 spin_lock(&po->bind_lock);
4103 if (po->running) {
4104 __unregister_prot_hook(sk, false);
4105 sk->sk_err = ENETDOWN;
4106 if (!sock_flag(sk, SOCK_DEAD))
4107 sk_error_report(sk);
4108 }
4109 if (msg == NETDEV_UNREGISTER) {
4110 packet_cached_dev_reset(po);
4111 WRITE_ONCE(po->ifindex, -1);
4112 if (po->prot_hook.dev)
4113 dev_put(po->prot_hook.dev);
4114 po->prot_hook.dev = NULL;
4115 }
4116 spin_unlock(&po->bind_lock);
4117 }
4118 break;
4119 case NETDEV_UP:
4120 if (dev->ifindex == po->ifindex) {
4121 spin_lock(&po->bind_lock);
4122 if (po->num)
4123 register_prot_hook(sk);
4124 spin_unlock(&po->bind_lock);
4125 }
4126 break;
4127 }
4128 }
4129 rcu_read_unlock();
4130 return NOTIFY_DONE;
4131}
4132
4133
4134static int packet_ioctl(struct socket *sock, unsigned int cmd,
4135 unsigned long arg)
4136{
4137 struct sock *sk = sock->sk;
4138
4139 switch (cmd) {
4140 case SIOCOUTQ:
4141 {
4142 int amount = sk_wmem_alloc_get(sk);
4143
4144 return put_user(amount, (int __user *)arg);
4145 }
4146 case SIOCINQ:
4147 {
4148 struct sk_buff *skb;
4149 int amount = 0;
4150
4151 spin_lock_bh(&sk->sk_receive_queue.lock);
4152 skb = skb_peek(&sk->sk_receive_queue);
4153 if (skb)
4154 amount = skb->len;
4155 spin_unlock_bh(&sk->sk_receive_queue.lock);
4156 return put_user(amount, (int __user *)arg);
4157 }
4158#ifdef CONFIG_INET
4159 case SIOCADDRT:
4160 case SIOCDELRT:
4161 case SIOCDARP:
4162 case SIOCGARP:
4163 case SIOCSARP:
4164 case SIOCGIFADDR:
4165 case SIOCSIFADDR:
4166 case SIOCGIFBRDADDR:
4167 case SIOCSIFBRDADDR:
4168 case SIOCGIFNETMASK:
4169 case SIOCSIFNETMASK:
4170 case SIOCGIFDSTADDR:
4171 case SIOCSIFDSTADDR:
4172 case SIOCSIFFLAGS:
4173 return inet_dgram_ops.ioctl(sock, cmd, arg);
4174#endif
4175
4176 default:
4177 return -ENOIOCTLCMD;
4178 }
4179 return 0;
4180}
4181
4182static __poll_t packet_poll(struct file *file, struct socket *sock,
4183 poll_table *wait)
4184{
4185 struct sock *sk = sock->sk;
4186 struct packet_sock *po = pkt_sk(sk);
4187 __poll_t mask = datagram_poll(file, sock, wait);
4188
4189 spin_lock_bh(&sk->sk_receive_queue.lock);
4190 if (po->rx_ring.pg_vec) {
4191 if (!packet_previous_rx_frame(po, &po->rx_ring,
4192 TP_STATUS_KERNEL))
4193 mask |= EPOLLIN | EPOLLRDNORM;
4194 }
4195 packet_rcv_try_clear_pressure(po);
4196 spin_unlock_bh(&sk->sk_receive_queue.lock);
4197 spin_lock_bh(&sk->sk_write_queue.lock);
4198 if (po->tx_ring.pg_vec) {
4199 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4200 mask |= EPOLLOUT | EPOLLWRNORM;
4201 }
4202 spin_unlock_bh(&sk->sk_write_queue.lock);
4203 return mask;
4204}
4205
4206
4207/* Dirty? Well, I still did not learn better way to account
4208 * for user mmaps.
4209 */
4210
4211static void packet_mm_open(struct vm_area_struct *vma)
4212{
4213 struct file *file = vma->vm_file;
4214 struct socket *sock = file->private_data;
4215 struct sock *sk = sock->sk;
4216
4217 if (sk)
4218 atomic_inc(&pkt_sk(sk)->mapped);
4219}
4220
4221static void packet_mm_close(struct vm_area_struct *vma)
4222{
4223 struct file *file = vma->vm_file;
4224 struct socket *sock = file->private_data;
4225 struct sock *sk = sock->sk;
4226
4227 if (sk)
4228 atomic_dec(&pkt_sk(sk)->mapped);
4229}
4230
4231static const struct vm_operations_struct packet_mmap_ops = {
4232 .open = packet_mm_open,
4233 .close = packet_mm_close,
4234};
4235
4236static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4237 unsigned int len)
4238{
4239 int i;
4240
4241 for (i = 0; i < len; i++) {
4242 if (likely(pg_vec[i].buffer)) {
4243 if (is_vmalloc_addr(pg_vec[i].buffer))
4244 vfree(pg_vec[i].buffer);
4245 else
4246 free_pages((unsigned long)pg_vec[i].buffer,
4247 order);
4248 pg_vec[i].buffer = NULL;
4249 }
4250 }
4251 kfree(pg_vec);
4252}
4253
4254static char *alloc_one_pg_vec_page(unsigned long order)
4255{
4256 char *buffer;
4257 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4258 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4259
4260 buffer = (char *) __get_free_pages(gfp_flags, order);
4261 if (buffer)
4262 return buffer;
4263
4264 /* __get_free_pages failed, fall back to vmalloc */
4265 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4266 if (buffer)
4267 return buffer;
4268
4269 /* vmalloc failed, lets dig into swap here */
4270 gfp_flags &= ~__GFP_NORETRY;
4271 buffer = (char *) __get_free_pages(gfp_flags, order);
4272 if (buffer)
4273 return buffer;
4274
4275 /* complete and utter failure */
4276 return NULL;
4277}
4278
4279static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4280{
4281 unsigned int block_nr = req->tp_block_nr;
4282 struct pgv *pg_vec;
4283 int i;
4284
4285 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4286 if (unlikely(!pg_vec))
4287 goto out;
4288
4289 for (i = 0; i < block_nr; i++) {
4290 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4291 if (unlikely(!pg_vec[i].buffer))
4292 goto out_free_pgvec;
4293 }
4294
4295out:
4296 return pg_vec;
4297
4298out_free_pgvec:
4299 free_pg_vec(pg_vec, order, block_nr);
4300 pg_vec = NULL;
4301 goto out;
4302}
4303
4304static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4305 int closing, int tx_ring)
4306{
4307 struct pgv *pg_vec = NULL;
4308 struct packet_sock *po = pkt_sk(sk);
4309 unsigned long *rx_owner_map = NULL;
4310 int was_running, order = 0;
4311 struct packet_ring_buffer *rb;
4312 struct sk_buff_head *rb_queue;
4313 __be16 num;
4314 int err;
4315 /* Added to avoid minimal code churn */
4316 struct tpacket_req *req = &req_u->req;
4317
4318 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4319 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4320
4321 err = -EBUSY;
4322 if (!closing) {
4323 if (atomic_read(&po->mapped))
4324 goto out;
4325 if (packet_read_pending(rb))
4326 goto out;
4327 }
4328
4329 if (req->tp_block_nr) {
4330 unsigned int min_frame_size;
4331
4332 /* Sanity tests and some calculations */
4333 err = -EBUSY;
4334 if (unlikely(rb->pg_vec))
4335 goto out;
4336
4337 switch (po->tp_version) {
4338 case TPACKET_V1:
4339 po->tp_hdrlen = TPACKET_HDRLEN;
4340 break;
4341 case TPACKET_V2:
4342 po->tp_hdrlen = TPACKET2_HDRLEN;
4343 break;
4344 case TPACKET_V3:
4345 po->tp_hdrlen = TPACKET3_HDRLEN;
4346 break;
4347 }
4348
4349 err = -EINVAL;
4350 if (unlikely((int)req->tp_block_size <= 0))
4351 goto out;
4352 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4353 goto out;
4354 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4355 if (po->tp_version >= TPACKET_V3 &&
4356 req->tp_block_size <
4357 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4358 goto out;
4359 if (unlikely(req->tp_frame_size < min_frame_size))
4360 goto out;
4361 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4362 goto out;
4363
4364 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4365 if (unlikely(rb->frames_per_block == 0))
4366 goto out;
4367 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4368 goto out;
4369 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4370 req->tp_frame_nr))
4371 goto out;
4372
4373 err = -ENOMEM;
4374 order = get_order(req->tp_block_size);
4375 pg_vec = alloc_pg_vec(req, order);
4376 if (unlikely(!pg_vec))
4377 goto out;
4378 switch (po->tp_version) {
4379 case TPACKET_V3:
4380 /* Block transmit is not supported yet */
4381 if (!tx_ring) {
4382 init_prb_bdqc(po, rb, pg_vec, req_u);
4383 } else {
4384 struct tpacket_req3 *req3 = &req_u->req3;
4385
4386 if (req3->tp_retire_blk_tov ||
4387 req3->tp_sizeof_priv ||
4388 req3->tp_feature_req_word) {
4389 err = -EINVAL;
4390 goto out_free_pg_vec;
4391 }
4392 }
4393 break;
4394 default:
4395 if (!tx_ring) {
4396 rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4397 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4398 if (!rx_owner_map)
4399 goto out_free_pg_vec;
4400 }
4401 break;
4402 }
4403 }
4404 /* Done */
4405 else {
4406 err = -EINVAL;
4407 if (unlikely(req->tp_frame_nr))
4408 goto out;
4409 }
4410
4411
4412 /* Detach socket from network */
4413 spin_lock(&po->bind_lock);
4414 was_running = po->running;
4415 num = po->num;
4416 if (was_running) {
4417 WRITE_ONCE(po->num, 0);
4418 __unregister_prot_hook(sk, false);
4419 }
4420 spin_unlock(&po->bind_lock);
4421
4422 synchronize_net();
4423
4424 err = -EBUSY;
4425 mutex_lock(&po->pg_vec_lock);
4426 if (closing || atomic_read(&po->mapped) == 0) {
4427 err = 0;
4428 spin_lock_bh(&rb_queue->lock);
4429 swap(rb->pg_vec, pg_vec);
4430 if (po->tp_version <= TPACKET_V2)
4431 swap(rb->rx_owner_map, rx_owner_map);
4432 rb->frame_max = (req->tp_frame_nr - 1);
4433 rb->head = 0;
4434 rb->frame_size = req->tp_frame_size;
4435 spin_unlock_bh(&rb_queue->lock);
4436
4437 swap(rb->pg_vec_order, order);
4438 swap(rb->pg_vec_len, req->tp_block_nr);
4439
4440 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4441 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4442 tpacket_rcv : packet_rcv;
4443 skb_queue_purge(rb_queue);
4444 if (atomic_read(&po->mapped))
4445 pr_err("packet_mmap: vma is busy: %d\n",
4446 atomic_read(&po->mapped));
4447 }
4448 mutex_unlock(&po->pg_vec_lock);
4449
4450 spin_lock(&po->bind_lock);
4451 if (was_running) {
4452 WRITE_ONCE(po->num, num);
4453 register_prot_hook(sk);
4454 }
4455 spin_unlock(&po->bind_lock);
4456 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4457 /* Because we don't support block-based V3 on tx-ring */
4458 if (!tx_ring)
4459 prb_shutdown_retire_blk_timer(po, rb_queue);
4460 }
4461
4462out_free_pg_vec:
4463 bitmap_free(rx_owner_map);
4464 if (pg_vec)
4465 free_pg_vec(pg_vec, order, req->tp_block_nr);
4466out:
4467 return err;
4468}
4469
4470static int packet_mmap(struct file *file, struct socket *sock,
4471 struct vm_area_struct *vma)
4472{
4473 struct sock *sk = sock->sk;
4474 struct packet_sock *po = pkt_sk(sk);
4475 unsigned long size, expected_size;
4476 struct packet_ring_buffer *rb;
4477 unsigned long start;
4478 int err = -EINVAL;
4479 int i;
4480
4481 if (vma->vm_pgoff)
4482 return -EINVAL;
4483
4484 mutex_lock(&po->pg_vec_lock);
4485
4486 expected_size = 0;
4487 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4488 if (rb->pg_vec) {
4489 expected_size += rb->pg_vec_len
4490 * rb->pg_vec_pages
4491 * PAGE_SIZE;
4492 }
4493 }
4494
4495 if (expected_size == 0)
4496 goto out;
4497
4498 size = vma->vm_end - vma->vm_start;
4499 if (size != expected_size)
4500 goto out;
4501
4502 start = vma->vm_start;
4503 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4504 if (rb->pg_vec == NULL)
4505 continue;
4506
4507 for (i = 0; i < rb->pg_vec_len; i++) {
4508 struct page *page;
4509 void *kaddr = rb->pg_vec[i].buffer;
4510 int pg_num;
4511
4512 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4513 page = pgv_to_page(kaddr);
4514 err = vm_insert_page(vma, start, page);
4515 if (unlikely(err))
4516 goto out;
4517 start += PAGE_SIZE;
4518 kaddr += PAGE_SIZE;
4519 }
4520 }
4521 }
4522
4523 atomic_inc(&po->mapped);
4524 vma->vm_ops = &packet_mmap_ops;
4525 err = 0;
4526
4527out:
4528 mutex_unlock(&po->pg_vec_lock);
4529 return err;
4530}
4531
4532static const struct proto_ops packet_ops_spkt = {
4533 .family = PF_PACKET,
4534 .owner = THIS_MODULE,
4535 .release = packet_release,
4536 .bind = packet_bind_spkt,
4537 .connect = sock_no_connect,
4538 .socketpair = sock_no_socketpair,
4539 .accept = sock_no_accept,
4540 .getname = packet_getname_spkt,
4541 .poll = datagram_poll,
4542 .ioctl = packet_ioctl,
4543 .gettstamp = sock_gettstamp,
4544 .listen = sock_no_listen,
4545 .shutdown = sock_no_shutdown,
4546 .sendmsg = packet_sendmsg_spkt,
4547 .recvmsg = packet_recvmsg,
4548 .mmap = sock_no_mmap,
4549 .sendpage = sock_no_sendpage,
4550};
4551
4552static const struct proto_ops packet_ops = {
4553 .family = PF_PACKET,
4554 .owner = THIS_MODULE,
4555 .release = packet_release,
4556 .bind = packet_bind,
4557 .connect = sock_no_connect,
4558 .socketpair = sock_no_socketpair,
4559 .accept = sock_no_accept,
4560 .getname = packet_getname,
4561 .poll = packet_poll,
4562 .ioctl = packet_ioctl,
4563 .gettstamp = sock_gettstamp,
4564 .listen = sock_no_listen,
4565 .shutdown = sock_no_shutdown,
4566 .setsockopt = packet_setsockopt,
4567 .getsockopt = packet_getsockopt,
4568 .sendmsg = packet_sendmsg,
4569 .recvmsg = packet_recvmsg,
4570 .mmap = packet_mmap,
4571 .sendpage = sock_no_sendpage,
4572};
4573
4574static const struct net_proto_family packet_family_ops = {
4575 .family = PF_PACKET,
4576 .create = packet_create,
4577 .owner = THIS_MODULE,
4578};
4579
4580static struct notifier_block packet_netdev_notifier = {
4581 .notifier_call = packet_notifier,
4582};
4583
4584#ifdef CONFIG_PROC_FS
4585
4586static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4587 __acquires(RCU)
4588{
4589 struct net *net = seq_file_net(seq);
4590
4591 rcu_read_lock();
4592 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4593}
4594
4595static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4596{
4597 struct net *net = seq_file_net(seq);
4598 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4599}
4600
4601static void packet_seq_stop(struct seq_file *seq, void *v)
4602 __releases(RCU)
4603{
4604 rcu_read_unlock();
4605}
4606
4607static int packet_seq_show(struct seq_file *seq, void *v)
4608{
4609 if (v == SEQ_START_TOKEN)
4610 seq_printf(seq,
4611 "%*sRefCnt Type Proto Iface R Rmem User Inode\n",
4612 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk");
4613 else {
4614 struct sock *s = sk_entry(v);
4615 const struct packet_sock *po = pkt_sk(s);
4616
4617 seq_printf(seq,
4618 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4619 s,
4620 refcount_read(&s->sk_refcnt),
4621 s->sk_type,
4622 ntohs(READ_ONCE(po->num)),
4623 READ_ONCE(po->ifindex),
4624 po->running,
4625 atomic_read(&s->sk_rmem_alloc),
4626 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4627 sock_i_ino(s));
4628 }
4629
4630 return 0;
4631}
4632
4633static const struct seq_operations packet_seq_ops = {
4634 .start = packet_seq_start,
4635 .next = packet_seq_next,
4636 .stop = packet_seq_stop,
4637 .show = packet_seq_show,
4638};
4639#endif
4640
4641static int __net_init packet_net_init(struct net *net)
4642{
4643 mutex_init(&net->packet.sklist_lock);
4644 INIT_HLIST_HEAD(&net->packet.sklist);
4645
4646#ifdef CONFIG_PROC_FS
4647 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4648 sizeof(struct seq_net_private)))
4649 return -ENOMEM;
4650#endif /* CONFIG_PROC_FS */
4651
4652 return 0;
4653}
4654
4655static void __net_exit packet_net_exit(struct net *net)
4656{
4657 remove_proc_entry("packet", net->proc_net);
4658 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4659}
4660
4661static struct pernet_operations packet_net_ops = {
4662 .init = packet_net_init,
4663 .exit = packet_net_exit,
4664};
4665
4666
4667static void __exit packet_exit(void)
4668{
4669 unregister_netdevice_notifier(&packet_netdev_notifier);
4670 unregister_pernet_subsys(&packet_net_ops);
4671 sock_unregister(PF_PACKET);
4672 proto_unregister(&packet_proto);
4673}
4674
4675static int __init packet_init(void)
4676{
4677 int rc;
4678
4679 rc = proto_register(&packet_proto, 0);
4680 if (rc)
4681 goto out;
4682 rc = sock_register(&packet_family_ops);
4683 if (rc)
4684 goto out_proto;
4685 rc = register_pernet_subsys(&packet_net_ops);
4686 if (rc)
4687 goto out_sock;
4688 rc = register_netdevice_notifier(&packet_netdev_notifier);
4689 if (rc)
4690 goto out_pernet;
4691
4692 return 0;
4693
4694out_pernet:
4695 unregister_pernet_subsys(&packet_net_ops);
4696out_sock:
4697 sock_unregister(PF_PACKET);
4698out_proto:
4699 proto_unregister(&packet_proto);
4700out:
4701 return rc;
4702}
4703
4704module_init(packet_init);
4705module_exit(packet_exit);
4706MODULE_LICENSE("GPL");
4707MODULE_ALIAS_NETPROTO(PF_PACKET);