2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * PACKET - implements raw packet sockets.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
55 #include <linux/types.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <linux/uaccess.h>
77 #include <asm/ioctls.h>
79 #include <asm/cacheflush.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/percpu.h>
93 #include <net/inet_common.h>
95 #include <linux/bpf.h>
96 #include <net/compat.h>
102 - if device has no dev->hard_header routine, it adds and removes ll header
103 inside itself. In this case ll header is invisible outside of device,
104 but higher levels still should reserve dev->hard_header_len.
105 Some devices are enough clever to reallocate skb, when header
106 will not fit to reserved space (tunnel), another ones are silly
108 - packet socket receives packets with pulled ll header,
109 so that SOCK_RAW should push it back.
114 Incoming, dev->hard_header!=NULL
115 mac_header -> ll header
118 Outgoing, dev->hard_header!=NULL
119 mac_header -> ll header
122 Incoming, dev->hard_header==NULL
123 mac_header -> UNKNOWN position. It is very likely, that it points to ll
124 header. PPP makes it, that is wrong, because introduce
125 assymetry between rx and tx paths.
128 Outgoing, dev->hard_header==NULL
129 mac_header -> data. ll header is still not built!
133 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
139 dev->hard_header != NULL
140 mac_header -> ll header
143 dev->hard_header == NULL (ll header is added by device, we cannot control it)
147 We should set nh.raw on output to correct posistion,
148 packet classifier depends on it.
151 /* Private packet socket structures. */
153 /* identical to struct packet_mreq except it has
154 * a longer address field.
156 struct packet_mreq_max {
158 unsigned short mr_type;
159 unsigned short mr_alen;
160 unsigned char mr_address[MAX_ADDR_LEN];
164 struct tpacket_hdr *h1;
165 struct tpacket2_hdr *h2;
166 struct tpacket3_hdr *h3;
170 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
171 int closing, int tx_ring);
173 #define V3_ALIGNMENT (8)
175 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
177 #define BLK_PLUS_PRIV(sz_of_priv) \
178 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
189 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
190 struct packet_type *pt, struct net_device *orig_dev);
192 static void *packet_previous_frame(struct packet_sock *po,
193 struct packet_ring_buffer *rb,
195 static void packet_increment_head(struct packet_ring_buffer *buff);
196 static int prb_curr_blk_in_use(struct tpacket_block_desc *);
197 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
198 struct packet_sock *);
199 static void prb_retire_current_block(struct tpacket_kbdq_core *,
200 struct packet_sock *, unsigned int status);
201 static int prb_queue_frozen(struct tpacket_kbdq_core *);
202 static void prb_open_block(struct tpacket_kbdq_core *,
203 struct tpacket_block_desc *);
204 static void prb_retire_rx_blk_timer_expired(struct timer_list *);
205 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
206 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
207 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
208 struct tpacket3_hdr *);
209 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
210 struct tpacket3_hdr *);
211 static void packet_flush_mclist(struct sock *sk);
212 static u16 packet_pick_tx_queue(struct sk_buff *skb);
214 struct packet_skb_cb {
216 struct sockaddr_pkt pkt;
218 /* Trick: alias skb original length with
219 * ll.sll_family and ll.protocol in order
222 unsigned int origlen;
223 struct sockaddr_ll ll;
228 #define vio_le() virtio_legacy_is_little_endian()
230 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
232 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
233 #define GET_PBLOCK_DESC(x, bid) \
234 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
235 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
236 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
237 #define GET_NEXT_PRB_BLK_NUM(x) \
238 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
239 ((x)->kactive_blk_num+1) : 0)
241 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
242 static void __fanout_link(struct sock *sk, struct packet_sock *po);
244 static int packet_direct_xmit(struct sk_buff *skb)
246 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
249 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
251 struct net_device *dev;
254 dev = rcu_dereference(po->cached_dev);
262 static void packet_cached_dev_assign(struct packet_sock *po,
263 struct net_device *dev)
265 rcu_assign_pointer(po->cached_dev, dev);
268 static void packet_cached_dev_reset(struct packet_sock *po)
270 RCU_INIT_POINTER(po->cached_dev, NULL);
273 static bool packet_use_direct_xmit(const struct packet_sock *po)
275 return po->xmit == packet_direct_xmit;
278 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
280 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
283 static u16 packet_pick_tx_queue(struct sk_buff *skb)
285 struct net_device *dev = skb->dev;
286 const struct net_device_ops *ops = dev->netdev_ops;
289 if (ops->ndo_select_queue) {
290 queue_index = ops->ndo_select_queue(dev, skb, NULL,
291 __packet_pick_tx_queue);
292 queue_index = netdev_cap_txqueue(dev, queue_index);
294 queue_index = __packet_pick_tx_queue(dev, skb);
300 /* __register_prot_hook must be invoked through register_prot_hook
301 * or from a context in which asynchronous accesses to the packet
302 * socket is not possible (packet_create()).
304 static void __register_prot_hook(struct sock *sk)
306 struct packet_sock *po = pkt_sk(sk);
310 __fanout_link(sk, po);
312 dev_add_pack(&po->prot_hook);
319 static void register_prot_hook(struct sock *sk)
321 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
322 __register_prot_hook(sk);
325 /* If the sync parameter is true, we will temporarily drop
326 * the po->bind_lock and do a synchronize_net to make sure no
327 * asynchronous packet processing paths still refer to the elements
328 * of po->prot_hook. If the sync parameter is false, it is the
329 * callers responsibility to take care of this.
331 static void __unregister_prot_hook(struct sock *sk, bool sync)
333 struct packet_sock *po = pkt_sk(sk);
335 lockdep_assert_held_once(&po->bind_lock);
340 __fanout_unlink(sk, po);
342 __dev_remove_pack(&po->prot_hook);
347 spin_unlock(&po->bind_lock);
349 spin_lock(&po->bind_lock);
353 static void unregister_prot_hook(struct sock *sk, bool sync)
355 struct packet_sock *po = pkt_sk(sk);
358 __unregister_prot_hook(sk, sync);
361 static inline struct page * __pure pgv_to_page(void *addr)
363 if (is_vmalloc_addr(addr))
364 return vmalloc_to_page(addr);
365 return virt_to_page(addr);
368 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
370 union tpacket_uhdr h;
373 switch (po->tp_version) {
375 h.h1->tp_status = status;
376 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
379 h.h2->tp_status = status;
380 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
383 h.h3->tp_status = status;
384 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
387 WARN(1, "TPACKET version not supported.\n");
394 static int __packet_get_status(struct packet_sock *po, void *frame)
396 union tpacket_uhdr h;
401 switch (po->tp_version) {
403 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
404 return h.h1->tp_status;
406 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
407 return h.h2->tp_status;
409 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
410 return h.h3->tp_status;
412 WARN(1, "TPACKET version not supported.\n");
418 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
421 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
424 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
425 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
426 return TP_STATUS_TS_RAW_HARDWARE;
428 if (ktime_to_timespec_cond(skb->tstamp, ts))
429 return TP_STATUS_TS_SOFTWARE;
434 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
437 union tpacket_uhdr h;
441 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
445 switch (po->tp_version) {
447 h.h1->tp_sec = ts.tv_sec;
448 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
451 h.h2->tp_sec = ts.tv_sec;
452 h.h2->tp_nsec = ts.tv_nsec;
455 h.h3->tp_sec = ts.tv_sec;
456 h.h3->tp_nsec = ts.tv_nsec;
459 WARN(1, "TPACKET version not supported.\n");
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));
470 static void *packet_lookup_frame(struct packet_sock *po,
471 struct packet_ring_buffer *rb,
472 unsigned int position,
475 unsigned int pg_vec_pos, frame_offset;
476 union tpacket_uhdr h;
478 pg_vec_pos = position / rb->frames_per_block;
479 frame_offset = position % rb->frames_per_block;
481 h.raw = rb->pg_vec[pg_vec_pos].buffer +
482 (frame_offset * rb->frame_size);
484 if (status != __packet_get_status(po, h.raw))
490 static void *packet_current_frame(struct packet_sock *po,
491 struct packet_ring_buffer *rb,
494 return packet_lookup_frame(po, rb, rb->head, status);
497 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
499 del_timer_sync(&pkc->retire_blk_timer);
502 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
503 struct sk_buff_head *rb_queue)
505 struct tpacket_kbdq_core *pkc;
507 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
509 spin_lock_bh(&rb_queue->lock);
510 pkc->delete_blk_timer = 1;
511 spin_unlock_bh(&rb_queue->lock);
513 prb_del_retire_blk_timer(pkc);
516 static void prb_setup_retire_blk_timer(struct packet_sock *po)
518 struct tpacket_kbdq_core *pkc;
520 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
521 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
523 pkc->retire_blk_timer.expires = jiffies;
526 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
527 int blk_size_in_bytes)
529 struct net_device *dev;
530 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
531 struct ethtool_link_ksettings ecmd;
535 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
536 if (unlikely(!dev)) {
538 return DEFAULT_PRB_RETIRE_TOV;
540 err = __ethtool_get_link_ksettings(dev, &ecmd);
544 * If the link speed is so slow you don't really
545 * need to worry about perf anyways
547 if (ecmd.base.speed < SPEED_1000 ||
548 ecmd.base.speed == SPEED_UNKNOWN) {
549 return DEFAULT_PRB_RETIRE_TOV;
552 div = ecmd.base.speed / 1000;
556 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
568 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
569 union tpacket_req_u *req_u)
571 p1->feature_req_word = req_u->req3.tp_feature_req_word;
574 static void init_prb_bdqc(struct packet_sock *po,
575 struct packet_ring_buffer *rb,
577 union tpacket_req_u *req_u)
579 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
580 struct tpacket_block_desc *pbd;
582 memset(p1, 0x0, sizeof(*p1));
584 p1->knxt_seq_num = 1;
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;
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;
602 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
603 prb_init_ft_ops(p1, req_u);
604 prb_setup_retire_blk_timer(po);
605 prb_open_block(p1, pbd);
608 /* Do NOT update the last_blk_num first.
609 * Assumes sk_buff_head lock is held.
611 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
613 mod_timer(&pkc->retire_blk_timer,
614 jiffies + pkc->tov_in_jiffies);
615 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
620 * 1) We refresh the timer only when we open a block.
621 * By doing this we don't waste cycles refreshing the timer
622 * on packet-by-packet basis.
624 * With a 1MB block-size, on a 1Gbps line, it will take
625 * i) ~8 ms to fill a block + ii) memcpy etc.
626 * In this cut we are not accounting for the memcpy time.
628 * So, if the user sets the 'tmo' to 10ms then the timer
629 * will never fire while the block is still getting filled
630 * (which is what we want). However, the user could choose
631 * to close a block early and that's fine.
633 * But when the timer does fire, we check whether or not to refresh it.
634 * Since the tmo granularity is in msecs, it is not too expensive
635 * to refresh the timer, lets say every '8' msecs.
636 * Either the user can set the 'tmo' or we can derive it based on
637 * a) line-speed and b) block-size.
638 * prb_calc_retire_blk_tmo() calculates the tmo.
641 static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
643 struct packet_sock *po =
644 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
645 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
647 struct tpacket_block_desc *pbd;
649 spin_lock(&po->sk.sk_receive_queue.lock);
651 frozen = prb_queue_frozen(pkc);
652 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
654 if (unlikely(pkc->delete_blk_timer))
657 /* We only need to plug the race when the block is partially filled.
659 * lock(); increment BLOCK_NUM_PKTS; unlock()
660 * copy_bits() is in progress ...
661 * timer fires on other cpu:
662 * we can't retire the current block because copy_bits
666 if (BLOCK_NUM_PKTS(pbd)) {
667 while (atomic_read(&pkc->blk_fill_in_prog)) {
668 /* Waiting for skb_copy_bits to finish... */
673 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
675 if (!BLOCK_NUM_PKTS(pbd)) {
676 /* An empty block. Just refresh the timer. */
679 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
680 if (!prb_dispatch_next_block(pkc, po))
685 /* Case 1. Queue was frozen because user-space was
688 if (prb_curr_blk_in_use(pbd)) {
690 * Ok, user-space is still behind.
691 * So just refresh the timer.
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.
702 prb_open_block(pkc, pbd);
709 _prb_refresh_rx_retire_blk_timer(pkc);
712 spin_unlock(&po->sk.sk_receive_queue.lock);
715 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
716 struct tpacket_block_desc *pbd1, __u32 status)
718 /* Flush everything minus the block header */
720 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
725 /* Skip the block header(we know header WILL fit in 4K) */
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));
735 /* Now update the block status. */
737 BLOCK_STATUS(pbd1) = status;
739 /* Flush the block header */
741 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
743 flush_dcache_page(pgv_to_page(start));
753 * 2) Increment active_blk_num
755 * Note:We DONT refresh the timer on purpose.
756 * Because almost always the next block will be opened.
758 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
759 struct tpacket_block_desc *pbd1,
760 struct packet_sock *po, unsigned int stat)
762 __u32 status = TP_STATUS_USER | stat;
764 struct tpacket3_hdr *last_pkt;
765 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
766 struct sock *sk = &po->sk;
768 if (po->stats.stats3.tp_drops)
769 status |= TP_STATUS_LOSING;
771 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
772 last_pkt->tp_next_offset = 0;
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;
779 /* Ok, we tmo'd - so get the current time.
781 * It shouldn't really happen as we don't close empty
782 * blocks. See prb_retire_rx_blk_timer_expired().
786 h1->ts_last_pkt.ts_sec = ts.tv_sec;
787 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
792 /* Flush the block */
793 prb_flush_block(pkc1, pbd1, status);
795 sk->sk_data_ready(sk);
797 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
800 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
802 pkc->reset_pending_on_curr_blk = 0;
806 * Side effect of opening a block:
808 * 1) prb_queue is thawed.
809 * 2) retire_blk_timer is refreshed.
812 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
813 struct tpacket_block_desc *pbd1)
816 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
820 /* We could have just memset this but we will lose the
821 * flexibility of making the priv area sticky
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);
830 h1->ts_first_pkt.ts_sec = ts.tv_sec;
831 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
833 pkc1->pkblk_start = (char *)pbd1;
834 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
836 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
837 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
839 pbd1->version = pkc1->version;
840 pkc1->prev = pkc1->nxt_offset;
841 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
843 prb_thaw_queue(pkc1);
844 _prb_refresh_rx_retire_blk_timer(pkc1);
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'.
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.
872 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
873 struct packet_sock *po)
875 pkc->reset_pending_on_curr_blk = 1;
876 po->stats.stats3.tp_freeze_q_cnt++;
879 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
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.
887 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
888 struct packet_sock *po)
890 struct tpacket_block_desc *pbd;
894 /* 1. Get current block num */
895 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
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);
905 * open this block and return the offset where the first packet
906 * needs to get stored.
908 prb_open_block(pkc, pbd);
909 return (void *)pkc->nxt_offset;
912 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
913 struct packet_sock *po, unsigned int status)
915 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
917 /* retire/close the current block */
918 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
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()
925 * We don't need to worry about the TMO case because
926 * the timer-handler already handled this case.
928 if (!(status & TP_STATUS_BLK_TMO)) {
929 while (atomic_read(&pkc->blk_fill_in_prog)) {
930 /* Waiting for skb_copy_bits to finish... */
934 prb_close_block(pkc, pbd, po, status);
939 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
941 return TP_STATUS_USER & BLOCK_STATUS(pbd);
944 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
946 return pkc->reset_pending_on_curr_blk;
949 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
951 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
952 atomic_dec(&pkc->blk_fill_in_prog);
955 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
956 struct tpacket3_hdr *ppd)
958 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
961 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
962 struct tpacket3_hdr *ppd)
964 ppd->hv1.tp_rxhash = 0;
967 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
968 struct tpacket3_hdr *ppd)
970 if (skb_vlan_tag_present(pkc->skb)) {
971 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
972 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
973 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
975 ppd->hv1.tp_vlan_tci = 0;
976 ppd->hv1.tp_vlan_tpid = 0;
977 ppd->tp_status = TP_STATUS_AVAILABLE;
981 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
982 struct tpacket3_hdr *ppd)
984 ppd->hv1.tp_padding = 0;
985 prb_fill_vlan_info(pkc, ppd);
987 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
988 prb_fill_rxhash(pkc, ppd);
990 prb_clear_rxhash(pkc, ppd);
993 static void prb_fill_curr_block(char *curr,
994 struct tpacket_kbdq_core *pkc,
995 struct tpacket_block_desc *pbd,
998 struct tpacket3_hdr *ppd;
1000 ppd = (struct tpacket3_hdr *)curr;
1001 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1003 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1004 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1005 BLOCK_NUM_PKTS(pbd) += 1;
1006 atomic_inc(&pkc->blk_fill_in_prog);
1007 prb_run_all_ft_ops(pkc, ppd);
1010 /* Assumes caller has the sk->rx_queue.lock */
1011 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1012 struct sk_buff *skb,
1017 struct tpacket_kbdq_core *pkc;
1018 struct tpacket_block_desc *pbd;
1021 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1022 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1024 /* Queue is frozen when user space is lagging behind */
1025 if (prb_queue_frozen(pkc)) {
1027 * Check if that last block which caused the queue to freeze,
1028 * is still in_use by user-space.
1030 if (prb_curr_blk_in_use(pbd)) {
1031 /* Can't record this packet */
1035 * Ok, the block was released by user-space.
1036 * Now let's open that block.
1037 * opening a block also thaws the queue.
1038 * Thawing is a side effect.
1040 prb_open_block(pkc, pbd);
1045 curr = pkc->nxt_offset;
1047 end = (char *)pbd + pkc->kblk_size;
1049 /* first try the current block */
1050 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1051 prb_fill_curr_block(curr, pkc, pbd, len);
1052 return (void *)curr;
1055 /* Ok, close the current block */
1056 prb_retire_current_block(pkc, po, 0);
1058 /* Now, try to dispatch the next block */
1059 curr = (char *)prb_dispatch_next_block(pkc, po);
1061 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1062 prb_fill_curr_block(curr, pkc, pbd, len);
1063 return (void *)curr;
1067 * No free blocks are available.user_space hasn't caught up yet.
1068 * Queue was just frozen and now this packet will get dropped.
1073 static void *packet_current_rx_frame(struct packet_sock *po,
1074 struct sk_buff *skb,
1075 int status, unsigned int len)
1078 switch (po->tp_version) {
1081 curr = packet_lookup_frame(po, &po->rx_ring,
1082 po->rx_ring.head, status);
1085 return __packet_lookup_frame_in_block(po, skb, status, len);
1087 WARN(1, "TPACKET version not supported\n");
1093 static void *prb_lookup_block(struct packet_sock *po,
1094 struct packet_ring_buffer *rb,
1098 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1099 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1101 if (status != BLOCK_STATUS(pbd))
1106 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1109 if (rb->prb_bdqc.kactive_blk_num)
1110 prev = rb->prb_bdqc.kactive_blk_num-1;
1112 prev = rb->prb_bdqc.knum_blocks-1;
1116 /* Assumes caller has held the rx_queue.lock */
1117 static void *__prb_previous_block(struct packet_sock *po,
1118 struct packet_ring_buffer *rb,
1121 unsigned int previous = prb_previous_blk_num(rb);
1122 return prb_lookup_block(po, rb, previous, status);
1125 static void *packet_previous_rx_frame(struct packet_sock *po,
1126 struct packet_ring_buffer *rb,
1129 if (po->tp_version <= TPACKET_V2)
1130 return packet_previous_frame(po, rb, status);
1132 return __prb_previous_block(po, rb, status);
1135 static void packet_increment_rx_head(struct packet_sock *po,
1136 struct packet_ring_buffer *rb)
1138 switch (po->tp_version) {
1141 return packet_increment_head(rb);
1144 WARN(1, "TPACKET version not supported.\n");
1150 static void *packet_previous_frame(struct packet_sock *po,
1151 struct packet_ring_buffer *rb,
1154 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1155 return packet_lookup_frame(po, rb, previous, status);
1158 static void packet_increment_head(struct packet_ring_buffer *buff)
1160 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1163 static void packet_inc_pending(struct packet_ring_buffer *rb)
1165 this_cpu_inc(*rb->pending_refcnt);
1168 static void packet_dec_pending(struct packet_ring_buffer *rb)
1170 this_cpu_dec(*rb->pending_refcnt);
1173 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1175 unsigned int refcnt = 0;
1178 /* We don't use pending refcount in rx_ring. */
1179 if (rb->pending_refcnt == NULL)
1182 for_each_possible_cpu(cpu)
1183 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1188 static int packet_alloc_pending(struct packet_sock *po)
1190 po->rx_ring.pending_refcnt = NULL;
1192 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1193 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1199 static void packet_free_pending(struct packet_sock *po)
1201 free_percpu(po->tx_ring.pending_refcnt);
1204 #define ROOM_POW_OFF 2
1205 #define ROOM_NONE 0x0
1206 #define ROOM_LOW 0x1
1207 #define ROOM_NORMAL 0x2
1209 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1213 len = po->rx_ring.frame_max + 1;
1214 idx = po->rx_ring.head;
1216 idx += len >> pow_off;
1219 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1222 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1226 len = po->rx_ring.prb_bdqc.knum_blocks;
1227 idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1229 idx += len >> pow_off;
1232 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1235 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1237 struct sock *sk = &po->sk;
1238 int ret = ROOM_NONE;
1240 if (po->prot_hook.func != tpacket_rcv) {
1241 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1242 - (skb ? skb->truesize : 0);
1243 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1251 if (po->tp_version == TPACKET_V3) {
1252 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1254 else if (__tpacket_v3_has_room(po, 0))
1257 if (__tpacket_has_room(po, ROOM_POW_OFF))
1259 else if (__tpacket_has_room(po, 0))
1266 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1271 spin_lock_bh(&po->sk.sk_receive_queue.lock);
1272 ret = __packet_rcv_has_room(po, skb);
1273 has_room = ret == ROOM_NORMAL;
1274 if (po->pressure == has_room)
1275 po->pressure = !has_room;
1276 spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1281 static void packet_sock_destruct(struct sock *sk)
1283 skb_queue_purge(&sk->sk_error_queue);
1285 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1286 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1288 if (!sock_flag(sk, SOCK_DEAD)) {
1289 pr_err("Attempt to release alive packet socket: %p\n", sk);
1293 sk_refcnt_debug_dec(sk);
1296 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1301 rxhash = skb_get_hash(skb);
1302 for (i = 0; i < ROLLOVER_HLEN; i++)
1303 if (po->rollover->history[i] == rxhash)
1306 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1307 return count > (ROLLOVER_HLEN >> 1);
1310 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1311 struct sk_buff *skb,
1314 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1317 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1318 struct sk_buff *skb,
1321 unsigned int val = atomic_inc_return(&f->rr_cur);
1326 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1327 struct sk_buff *skb,
1330 return smp_processor_id() % num;
1333 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1334 struct sk_buff *skb,
1337 return prandom_u32_max(num);
1340 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1341 struct sk_buff *skb,
1342 unsigned int idx, bool try_self,
1345 struct packet_sock *po, *po_next, *po_skip = NULL;
1346 unsigned int i, j, room = ROOM_NONE;
1348 po = pkt_sk(f->arr[idx]);
1351 room = packet_rcv_has_room(po, skb);
1352 if (room == ROOM_NORMAL ||
1353 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1358 i = j = min_t(int, po->rollover->sock, num - 1);
1360 po_next = pkt_sk(f->arr[i]);
1361 if (po_next != po_skip && !po_next->pressure &&
1362 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1364 po->rollover->sock = i;
1365 atomic_long_inc(&po->rollover->num);
1366 if (room == ROOM_LOW)
1367 atomic_long_inc(&po->rollover->num_huge);
1375 atomic_long_inc(&po->rollover->num_failed);
1379 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1380 struct sk_buff *skb,
1383 return skb_get_queue_mapping(skb) % num;
1386 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1387 struct sk_buff *skb,
1390 struct bpf_prog *prog;
1391 unsigned int ret = 0;
1394 prog = rcu_dereference(f->bpf_prog);
1396 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1402 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1404 return f->flags & (flag >> 8);
1407 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1408 struct packet_type *pt, struct net_device *orig_dev)
1410 struct packet_fanout *f = pt->af_packet_priv;
1411 unsigned int num = READ_ONCE(f->num_members);
1412 struct net *net = read_pnet(&f->net);
1413 struct packet_sock *po;
1416 if (!net_eq(dev_net(dev), net) || !num) {
1421 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1422 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1427 case PACKET_FANOUT_HASH:
1429 idx = fanout_demux_hash(f, skb, num);
1431 case PACKET_FANOUT_LB:
1432 idx = fanout_demux_lb(f, skb, num);
1434 case PACKET_FANOUT_CPU:
1435 idx = fanout_demux_cpu(f, skb, num);
1437 case PACKET_FANOUT_RND:
1438 idx = fanout_demux_rnd(f, skb, num);
1440 case PACKET_FANOUT_QM:
1441 idx = fanout_demux_qm(f, skb, num);
1443 case PACKET_FANOUT_ROLLOVER:
1444 idx = fanout_demux_rollover(f, skb, 0, false, num);
1446 case PACKET_FANOUT_CBPF:
1447 case PACKET_FANOUT_EBPF:
1448 idx = fanout_demux_bpf(f, skb, num);
1452 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1453 idx = fanout_demux_rollover(f, skb, idx, true, num);
1455 po = pkt_sk(f->arr[idx]);
1456 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1459 DEFINE_MUTEX(fanout_mutex);
1460 EXPORT_SYMBOL_GPL(fanout_mutex);
1461 static LIST_HEAD(fanout_list);
1462 static u16 fanout_next_id;
1464 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1466 struct packet_fanout *f = po->fanout;
1468 spin_lock(&f->lock);
1469 f->arr[f->num_members] = sk;
1472 if (f->num_members == 1)
1473 dev_add_pack(&f->prot_hook);
1474 spin_unlock(&f->lock);
1477 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1479 struct packet_fanout *f = po->fanout;
1482 spin_lock(&f->lock);
1483 for (i = 0; i < f->num_members; i++) {
1484 if (f->arr[i] == sk)
1487 BUG_ON(i >= f->num_members);
1488 f->arr[i] = f->arr[f->num_members - 1];
1490 if (f->num_members == 0)
1491 __dev_remove_pack(&f->prot_hook);
1492 spin_unlock(&f->lock);
1495 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1497 if (sk->sk_family != PF_PACKET)
1500 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1503 static void fanout_init_data(struct packet_fanout *f)
1506 case PACKET_FANOUT_LB:
1507 atomic_set(&f->rr_cur, 0);
1509 case PACKET_FANOUT_CBPF:
1510 case PACKET_FANOUT_EBPF:
1511 RCU_INIT_POINTER(f->bpf_prog, NULL);
1516 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1518 struct bpf_prog *old;
1520 spin_lock(&f->lock);
1521 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1522 rcu_assign_pointer(f->bpf_prog, new);
1523 spin_unlock(&f->lock);
1527 bpf_prog_destroy(old);
1531 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1534 struct bpf_prog *new;
1535 struct sock_fprog fprog;
1538 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1540 if (len != sizeof(fprog))
1542 if (copy_from_user(&fprog, data, len))
1545 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1549 __fanout_set_data_bpf(po->fanout, new);
1553 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1556 struct bpf_prog *new;
1559 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1561 if (len != sizeof(fd))
1563 if (copy_from_user(&fd, data, len))
1566 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1568 return PTR_ERR(new);
1570 __fanout_set_data_bpf(po->fanout, new);
1574 static int fanout_set_data(struct packet_sock *po, char __user *data,
1577 switch (po->fanout->type) {
1578 case PACKET_FANOUT_CBPF:
1579 return fanout_set_data_cbpf(po, data, len);
1580 case PACKET_FANOUT_EBPF:
1581 return fanout_set_data_ebpf(po, data, len);
1587 static void fanout_release_data(struct packet_fanout *f)
1590 case PACKET_FANOUT_CBPF:
1591 case PACKET_FANOUT_EBPF:
1592 __fanout_set_data_bpf(f, NULL);
1596 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1598 struct packet_fanout *f;
1600 list_for_each_entry(f, &fanout_list, list) {
1601 if (f->id == candidate_id &&
1602 read_pnet(&f->net) == sock_net(sk)) {
1609 static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1611 u16 id = fanout_next_id;
1614 if (__fanout_id_is_free(sk, id)) {
1616 fanout_next_id = id + 1;
1621 } while (id != fanout_next_id);
1626 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1628 struct packet_rollover *rollover = NULL;
1629 struct packet_sock *po = pkt_sk(sk);
1630 struct packet_fanout *f, *match;
1631 u8 type = type_flags & 0xff;
1632 u8 flags = type_flags >> 8;
1636 case PACKET_FANOUT_ROLLOVER:
1637 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1639 case PACKET_FANOUT_HASH:
1640 case PACKET_FANOUT_LB:
1641 case PACKET_FANOUT_CPU:
1642 case PACKET_FANOUT_RND:
1643 case PACKET_FANOUT_QM:
1644 case PACKET_FANOUT_CBPF:
1645 case PACKET_FANOUT_EBPF:
1651 mutex_lock(&fanout_mutex);
1657 if (type == PACKET_FANOUT_ROLLOVER ||
1658 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1660 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1663 atomic_long_set(&rollover->num, 0);
1664 atomic_long_set(&rollover->num_huge, 0);
1665 atomic_long_set(&rollover->num_failed, 0);
1668 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1673 if (!fanout_find_new_id(sk, &id)) {
1677 /* ephemeral flag for the first socket in the group: drop it */
1678 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1682 list_for_each_entry(f, &fanout_list, list) {
1684 read_pnet(&f->net) == sock_net(sk)) {
1690 if (match && match->flags != flags)
1694 match = kzalloc(sizeof(*match), GFP_KERNEL);
1697 write_pnet(&match->net, sock_net(sk));
1700 match->flags = flags;
1701 INIT_LIST_HEAD(&match->list);
1702 spin_lock_init(&match->lock);
1703 refcount_set(&match->sk_ref, 0);
1704 fanout_init_data(match);
1705 match->prot_hook.type = po->prot_hook.type;
1706 match->prot_hook.dev = po->prot_hook.dev;
1707 match->prot_hook.func = packet_rcv_fanout;
1708 match->prot_hook.af_packet_priv = match;
1709 match->prot_hook.id_match = match_fanout_group;
1710 list_add(&match->list, &fanout_list);
1714 spin_lock(&po->bind_lock);
1716 match->type == type &&
1717 match->prot_hook.type == po->prot_hook.type &&
1718 match->prot_hook.dev == po->prot_hook.dev) {
1720 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1721 __dev_remove_pack(&po->prot_hook);
1723 po->rollover = rollover;
1725 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1726 __fanout_link(sk, po);
1730 spin_unlock(&po->bind_lock);
1732 if (err && !refcount_read(&match->sk_ref)) {
1733 list_del(&match->list);
1739 mutex_unlock(&fanout_mutex);
1743 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1744 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1745 * It is the responsibility of the caller to call fanout_release_data() and
1746 * free the returned packet_fanout (after synchronize_net())
1748 static struct packet_fanout *fanout_release(struct sock *sk)
1750 struct packet_sock *po = pkt_sk(sk);
1751 struct packet_fanout *f;
1753 mutex_lock(&fanout_mutex);
1758 if (refcount_dec_and_test(&f->sk_ref))
1763 mutex_unlock(&fanout_mutex);
1768 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1769 struct sk_buff *skb)
1771 /* Earlier code assumed this would be a VLAN pkt, double-check
1772 * this now that we have the actual packet in hand. We can only
1773 * do this check on Ethernet devices.
1775 if (unlikely(dev->type != ARPHRD_ETHER))
1778 skb_reset_mac_header(skb);
1779 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1782 static const struct proto_ops packet_ops;
1784 static const struct proto_ops packet_ops_spkt;
1786 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1787 struct packet_type *pt, struct net_device *orig_dev)
1790 struct sockaddr_pkt *spkt;
1793 * When we registered the protocol we saved the socket in the data
1794 * field for just this event.
1797 sk = pt->af_packet_priv;
1800 * Yank back the headers [hope the device set this
1801 * right or kerboom...]
1803 * Incoming packets have ll header pulled,
1806 * For outgoing ones skb->data == skb_mac_header(skb)
1807 * so that this procedure is noop.
1810 if (skb->pkt_type == PACKET_LOOPBACK)
1813 if (!net_eq(dev_net(dev), sock_net(sk)))
1816 skb = skb_share_check(skb, GFP_ATOMIC);
1820 /* drop any routing info */
1823 /* drop conntrack reference */
1826 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1828 skb_push(skb, skb->data - skb_mac_header(skb));
1831 * The SOCK_PACKET socket receives _all_ frames.
1834 spkt->spkt_family = dev->type;
1835 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1836 spkt->spkt_protocol = skb->protocol;
1839 * Charge the memory to the socket. This is done specifically
1840 * to prevent sockets using all the memory up.
1843 if (sock_queue_rcv_skb(sk, skb) == 0)
1854 * Output a raw packet to a device layer. This bypasses all the other
1855 * protocol layers and you must therefore supply it with a complete frame
1858 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1861 struct sock *sk = sock->sk;
1862 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1863 struct sk_buff *skb = NULL;
1864 struct net_device *dev;
1865 struct sockcm_cookie sockc;
1871 * Get and verify the address.
1875 if (msg->msg_namelen < sizeof(struct sockaddr))
1877 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1878 proto = saddr->spkt_protocol;
1880 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1883 * Find the device first to size check it
1886 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1889 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1895 if (!(dev->flags & IFF_UP))
1899 * You may not queue a frame bigger than the mtu. This is the lowest level
1900 * raw protocol and you must do your own fragmentation at this level.
1903 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1904 if (!netif_supports_nofcs(dev)) {
1905 err = -EPROTONOSUPPORT;
1908 extra_len = 4; /* We're doing our own CRC */
1912 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1916 size_t reserved = LL_RESERVED_SPACE(dev);
1917 int tlen = dev->needed_tailroom;
1918 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1921 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1924 /* FIXME: Save some space for broken drivers that write a hard
1925 * header at transmission time by themselves. PPP is the notable
1926 * one here. This should really be fixed at the driver level.
1928 skb_reserve(skb, reserved);
1929 skb_reset_network_header(skb);
1931 /* Try to align data part correctly */
1936 skb_reset_network_header(skb);
1938 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1944 if (!dev_validate_header(dev, skb->data, len)) {
1948 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1949 !packet_extra_vlan_len_allowed(dev, skb)) {
1954 sockc.tsflags = sk->sk_tsflags;
1955 if (msg->msg_controllen) {
1956 err = sock_cmsg_send(sk, msg, &sockc);
1961 skb->protocol = proto;
1963 skb->priority = sk->sk_priority;
1964 skb->mark = sk->sk_mark;
1966 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
1968 if (unlikely(extra_len == 4))
1971 skb_probe_transport_header(skb, 0);
1973 dev_queue_xmit(skb);
1984 static unsigned int run_filter(struct sk_buff *skb,
1985 const struct sock *sk,
1988 struct sk_filter *filter;
1991 filter = rcu_dereference(sk->sk_filter);
1993 res = bpf_prog_run_clear_cb(filter->prog, skb);
1999 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2002 struct virtio_net_hdr vnet_hdr;
2004 if (*len < sizeof(vnet_hdr))
2006 *len -= sizeof(vnet_hdr);
2008 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2011 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2015 * This function makes lazy skb cloning in hope that most of packets
2016 * are discarded by BPF.
2018 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2019 * and skb->cb are mangled. It works because (and until) packets
2020 * falling here are owned by current CPU. Output packets are cloned
2021 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2022 * sequencially, so that if we return skb to original state on exit,
2023 * we will not harm anyone.
2026 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2027 struct packet_type *pt, struct net_device *orig_dev)
2030 struct sockaddr_ll *sll;
2031 struct packet_sock *po;
2032 u8 *skb_head = skb->data;
2033 int skb_len = skb->len;
2034 unsigned int snaplen, res;
2035 bool is_drop_n_account = false;
2037 if (skb->pkt_type == PACKET_LOOPBACK)
2040 sk = pt->af_packet_priv;
2043 if (!net_eq(dev_net(dev), sock_net(sk)))
2048 if (dev->header_ops) {
2049 /* The device has an explicit notion of ll header,
2050 * exported to higher levels.
2052 * Otherwise, the device hides details of its frame
2053 * structure, so that corresponding packet head is
2054 * never delivered to user.
2056 if (sk->sk_type != SOCK_DGRAM)
2057 skb_push(skb, skb->data - skb_mac_header(skb));
2058 else if (skb->pkt_type == PACKET_OUTGOING) {
2059 /* Special case: outgoing packets have ll header at head */
2060 skb_pull(skb, skb_network_offset(skb));
2066 res = run_filter(skb, sk, snaplen);
2068 goto drop_n_restore;
2072 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2075 if (skb_shared(skb)) {
2076 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2080 if (skb_head != skb->data) {
2081 skb->data = skb_head;
2088 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2090 sll = &PACKET_SKB_CB(skb)->sa.ll;
2091 sll->sll_hatype = dev->type;
2092 sll->sll_pkttype = skb->pkt_type;
2093 if (unlikely(po->origdev))
2094 sll->sll_ifindex = orig_dev->ifindex;
2096 sll->sll_ifindex = dev->ifindex;
2098 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2100 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2101 * Use their space for storing the original skb length.
2103 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2105 if (pskb_trim(skb, snaplen))
2108 skb_set_owner_r(skb, sk);
2112 /* drop conntrack reference */
2115 spin_lock(&sk->sk_receive_queue.lock);
2116 po->stats.stats1.tp_packets++;
2117 sock_skb_set_dropcount(sk, skb);
2118 __skb_queue_tail(&sk->sk_receive_queue, skb);
2119 spin_unlock(&sk->sk_receive_queue.lock);
2120 sk->sk_data_ready(sk);
2124 is_drop_n_account = true;
2125 spin_lock(&sk->sk_receive_queue.lock);
2126 po->stats.stats1.tp_drops++;
2127 atomic_inc(&sk->sk_drops);
2128 spin_unlock(&sk->sk_receive_queue.lock);
2131 if (skb_head != skb->data && skb_shared(skb)) {
2132 skb->data = skb_head;
2136 if (!is_drop_n_account)
2143 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2144 struct packet_type *pt, struct net_device *orig_dev)
2147 struct packet_sock *po;
2148 struct sockaddr_ll *sll;
2149 union tpacket_uhdr h;
2150 u8 *skb_head = skb->data;
2151 int skb_len = skb->len;
2152 unsigned int snaplen, res;
2153 unsigned long status = TP_STATUS_USER;
2154 unsigned short macoff, netoff, hdrlen;
2155 struct sk_buff *copy_skb = NULL;
2158 bool is_drop_n_account = false;
2159 bool do_vnet = false;
2161 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2162 * We may add members to them until current aligned size without forcing
2163 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2165 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2166 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2168 if (skb->pkt_type == PACKET_LOOPBACK)
2171 sk = pt->af_packet_priv;
2174 if (!net_eq(dev_net(dev), sock_net(sk)))
2177 if (dev->header_ops) {
2178 if (sk->sk_type != SOCK_DGRAM)
2179 skb_push(skb, skb->data - skb_mac_header(skb));
2180 else if (skb->pkt_type == PACKET_OUTGOING) {
2181 /* Special case: outgoing packets have ll header at head */
2182 skb_pull(skb, skb_network_offset(skb));
2188 res = run_filter(skb, sk, snaplen);
2190 goto drop_n_restore;
2192 if (skb->ip_summed == CHECKSUM_PARTIAL)
2193 status |= TP_STATUS_CSUMNOTREADY;
2194 else if (skb->pkt_type != PACKET_OUTGOING &&
2195 (skb->ip_summed == CHECKSUM_COMPLETE ||
2196 skb_csum_unnecessary(skb)))
2197 status |= TP_STATUS_CSUM_VALID;
2202 if (sk->sk_type == SOCK_DGRAM) {
2203 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2206 unsigned int maclen = skb_network_offset(skb);
2207 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2208 (maclen < 16 ? 16 : maclen)) +
2210 if (po->has_vnet_hdr) {
2211 netoff += sizeof(struct virtio_net_hdr);
2214 macoff = netoff - maclen;
2216 if (po->tp_version <= TPACKET_V2) {
2217 if (macoff + snaplen > po->rx_ring.frame_size) {
2218 if (po->copy_thresh &&
2219 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2220 if (skb_shared(skb)) {
2221 copy_skb = skb_clone(skb, GFP_ATOMIC);
2223 copy_skb = skb_get(skb);
2224 skb_head = skb->data;
2227 skb_set_owner_r(copy_skb, sk);
2229 snaplen = po->rx_ring.frame_size - macoff;
2230 if ((int)snaplen < 0) {
2235 } else if (unlikely(macoff + snaplen >
2236 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2239 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2240 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2241 snaplen, nval, macoff);
2243 if (unlikely((int)snaplen < 0)) {
2245 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2249 spin_lock(&sk->sk_receive_queue.lock);
2250 h.raw = packet_current_rx_frame(po, skb,
2251 TP_STATUS_KERNEL, (macoff+snaplen));
2253 goto drop_n_account;
2254 if (po->tp_version <= TPACKET_V2) {
2255 packet_increment_rx_head(po, &po->rx_ring);
2257 * LOSING will be reported till you read the stats,
2258 * because it's COR - Clear On Read.
2259 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2262 if (po->stats.stats1.tp_drops)
2263 status |= TP_STATUS_LOSING;
2265 po->stats.stats1.tp_packets++;
2267 status |= TP_STATUS_COPY;
2268 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2270 spin_unlock(&sk->sk_receive_queue.lock);
2273 if (virtio_net_hdr_from_skb(skb, h.raw + macoff -
2274 sizeof(struct virtio_net_hdr),
2275 vio_le(), true, 0)) {
2276 spin_lock(&sk->sk_receive_queue.lock);
2277 goto drop_n_account;
2281 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2283 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2284 getnstimeofday(&ts);
2286 status |= ts_status;
2288 switch (po->tp_version) {
2290 h.h1->tp_len = skb->len;
2291 h.h1->tp_snaplen = snaplen;
2292 h.h1->tp_mac = macoff;
2293 h.h1->tp_net = netoff;
2294 h.h1->tp_sec = ts.tv_sec;
2295 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2296 hdrlen = sizeof(*h.h1);
2299 h.h2->tp_len = skb->len;
2300 h.h2->tp_snaplen = snaplen;
2301 h.h2->tp_mac = macoff;
2302 h.h2->tp_net = netoff;
2303 h.h2->tp_sec = ts.tv_sec;
2304 h.h2->tp_nsec = ts.tv_nsec;
2305 if (skb_vlan_tag_present(skb)) {
2306 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2307 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2308 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2310 h.h2->tp_vlan_tci = 0;
2311 h.h2->tp_vlan_tpid = 0;
2313 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2314 hdrlen = sizeof(*h.h2);
2317 /* tp_nxt_offset,vlan are already populated above.
2318 * So DONT clear those fields here
2320 h.h3->tp_status |= status;
2321 h.h3->tp_len = skb->len;
2322 h.h3->tp_snaplen = snaplen;
2323 h.h3->tp_mac = macoff;
2324 h.h3->tp_net = netoff;
2325 h.h3->tp_sec = ts.tv_sec;
2326 h.h3->tp_nsec = ts.tv_nsec;
2327 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2328 hdrlen = sizeof(*h.h3);
2334 sll = h.raw + TPACKET_ALIGN(hdrlen);
2335 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2336 sll->sll_family = AF_PACKET;
2337 sll->sll_hatype = dev->type;
2338 sll->sll_protocol = skb->protocol;
2339 sll->sll_pkttype = skb->pkt_type;
2340 if (unlikely(po->origdev))
2341 sll->sll_ifindex = orig_dev->ifindex;
2343 sll->sll_ifindex = dev->ifindex;
2347 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2348 if (po->tp_version <= TPACKET_V2) {
2351 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2354 for (start = h.raw; start < end; start += PAGE_SIZE)
2355 flush_dcache_page(pgv_to_page(start));
2360 if (po->tp_version <= TPACKET_V2) {
2361 __packet_set_status(po, h.raw, status);
2362 sk->sk_data_ready(sk);
2364 prb_clear_blk_fill_status(&po->rx_ring);
2368 if (skb_head != skb->data && skb_shared(skb)) {
2369 skb->data = skb_head;
2373 if (!is_drop_n_account)
2380 is_drop_n_account = true;
2381 po->stats.stats1.tp_drops++;
2382 spin_unlock(&sk->sk_receive_queue.lock);
2384 sk->sk_data_ready(sk);
2385 kfree_skb(copy_skb);
2386 goto drop_n_restore;
2389 static void tpacket_destruct_skb(struct sk_buff *skb)
2391 struct packet_sock *po = pkt_sk(skb->sk);
2393 if (likely(po->tx_ring.pg_vec)) {
2397 ph = skb_shinfo(skb)->destructor_arg;
2398 packet_dec_pending(&po->tx_ring);
2400 ts = __packet_set_timestamp(po, ph, skb);
2401 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2407 static void tpacket_set_protocol(const struct net_device *dev,
2408 struct sk_buff *skb)
2410 if (dev->type == ARPHRD_ETHER) {
2411 skb_reset_mac_header(skb);
2412 skb->protocol = eth_hdr(skb)->h_proto;
2416 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2418 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2419 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2420 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2421 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2422 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2423 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2424 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2426 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2432 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2433 struct virtio_net_hdr *vnet_hdr)
2435 if (*len < sizeof(*vnet_hdr))
2437 *len -= sizeof(*vnet_hdr);
2439 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2442 return __packet_snd_vnet_parse(vnet_hdr, *len);
2445 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2446 void *frame, struct net_device *dev, void *data, int tp_len,
2447 __be16 proto, unsigned char *addr, int hlen, int copylen,
2448 const struct sockcm_cookie *sockc)
2450 union tpacket_uhdr ph;
2451 int to_write, offset, len, nr_frags, len_max;
2452 struct socket *sock = po->sk.sk_socket;
2458 skb->protocol = proto;
2460 skb->priority = po->sk.sk_priority;
2461 skb->mark = po->sk.sk_mark;
2462 sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);
2463 skb_shinfo(skb)->destructor_arg = ph.raw;
2465 skb_reserve(skb, hlen);
2466 skb_reset_network_header(skb);
2470 if (sock->type == SOCK_DGRAM) {
2471 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2473 if (unlikely(err < 0))
2475 } else if (copylen) {
2476 int hdrlen = min_t(int, copylen, tp_len);
2478 skb_push(skb, dev->hard_header_len);
2479 skb_put(skb, copylen - dev->hard_header_len);
2480 err = skb_store_bits(skb, 0, data, hdrlen);
2483 if (!dev_validate_header(dev, skb->data, hdrlen))
2486 tpacket_set_protocol(dev, skb);
2492 offset = offset_in_page(data);
2493 len_max = PAGE_SIZE - offset;
2494 len = ((to_write > len_max) ? len_max : to_write);
2496 skb->data_len = to_write;
2497 skb->len += to_write;
2498 skb->truesize += to_write;
2499 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2501 while (likely(to_write)) {
2502 nr_frags = skb_shinfo(skb)->nr_frags;
2504 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2505 pr_err("Packet exceed the number of skb frags(%lu)\n",
2510 page = pgv_to_page(data);
2512 flush_dcache_page(page);
2514 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2517 len_max = PAGE_SIZE;
2518 len = ((to_write > len_max) ? len_max : to_write);
2521 skb_probe_transport_header(skb, 0);
2526 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2527 int size_max, void **data)
2529 union tpacket_uhdr ph;
2534 switch (po->tp_version) {
2536 if (ph.h3->tp_next_offset != 0) {
2537 pr_warn_once("variable sized slot not supported");
2540 tp_len = ph.h3->tp_len;
2543 tp_len = ph.h2->tp_len;
2546 tp_len = ph.h1->tp_len;
2549 if (unlikely(tp_len > size_max)) {
2550 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2554 if (unlikely(po->tp_tx_has_off)) {
2555 int off_min, off_max;
2557 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2558 off_max = po->tx_ring.frame_size - tp_len;
2559 if (po->sk.sk_type == SOCK_DGRAM) {
2560 switch (po->tp_version) {
2562 off = ph.h3->tp_net;
2565 off = ph.h2->tp_net;
2568 off = ph.h1->tp_net;
2572 switch (po->tp_version) {
2574 off = ph.h3->tp_mac;
2577 off = ph.h2->tp_mac;
2580 off = ph.h1->tp_mac;
2584 if (unlikely((off < off_min) || (off_max < off)))
2587 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2590 *data = frame + off;
2594 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2596 struct sk_buff *skb;
2597 struct net_device *dev;
2598 struct virtio_net_hdr *vnet_hdr = NULL;
2599 struct sockcm_cookie sockc;
2601 int err, reserve = 0;
2603 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2604 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2605 int tp_len, size_max;
2606 unsigned char *addr;
2609 int status = TP_STATUS_AVAILABLE;
2610 int hlen, tlen, copylen = 0;
2612 mutex_lock(&po->pg_vec_lock);
2614 if (likely(saddr == NULL)) {
2615 dev = packet_cached_dev_get(po);
2620 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2622 if (msg->msg_namelen < (saddr->sll_halen
2623 + offsetof(struct sockaddr_ll,
2626 proto = saddr->sll_protocol;
2627 addr = saddr->sll_addr;
2628 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2632 if (unlikely(dev == NULL))
2635 if (unlikely(!(dev->flags & IFF_UP)))
2638 sockc.tsflags = po->sk.sk_tsflags;
2639 if (msg->msg_controllen) {
2640 err = sock_cmsg_send(&po->sk, msg, &sockc);
2645 if (po->sk.sk_socket->type == SOCK_RAW)
2646 reserve = dev->hard_header_len;
2647 size_max = po->tx_ring.frame_size
2648 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2650 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2651 size_max = dev->mtu + reserve + VLAN_HLEN;
2654 ph = packet_current_frame(po, &po->tx_ring,
2655 TP_STATUS_SEND_REQUEST);
2656 if (unlikely(ph == NULL)) {
2657 if (need_wait && need_resched())
2663 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2667 status = TP_STATUS_SEND_REQUEST;
2668 hlen = LL_RESERVED_SPACE(dev);
2669 tlen = dev->needed_tailroom;
2670 if (po->has_vnet_hdr) {
2672 data += sizeof(*vnet_hdr);
2673 tp_len -= sizeof(*vnet_hdr);
2675 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2679 copylen = __virtio16_to_cpu(vio_le(),
2682 copylen = max_t(int, copylen, dev->hard_header_len);
2683 skb = sock_alloc_send_skb(&po->sk,
2684 hlen + tlen + sizeof(struct sockaddr_ll) +
2685 (copylen - dev->hard_header_len),
2688 if (unlikely(skb == NULL)) {
2689 /* we assume the socket was initially writeable ... */
2690 if (likely(len_sum > 0))
2694 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2695 addr, hlen, copylen, &sockc);
2696 if (likely(tp_len >= 0) &&
2697 tp_len > dev->mtu + reserve &&
2698 !po->has_vnet_hdr &&
2699 !packet_extra_vlan_len_allowed(dev, skb))
2702 if (unlikely(tp_len < 0)) {
2705 __packet_set_status(po, ph,
2706 TP_STATUS_AVAILABLE);
2707 packet_increment_head(&po->tx_ring);
2711 status = TP_STATUS_WRONG_FORMAT;
2717 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr,
2723 skb->destructor = tpacket_destruct_skb;
2724 __packet_set_status(po, ph, TP_STATUS_SENDING);
2725 packet_inc_pending(&po->tx_ring);
2727 status = TP_STATUS_SEND_REQUEST;
2728 err = po->xmit(skb);
2729 if (unlikely(err > 0)) {
2730 err = net_xmit_errno(err);
2731 if (err && __packet_get_status(po, ph) ==
2732 TP_STATUS_AVAILABLE) {
2733 /* skb was destructed already */
2738 * skb was dropped but not destructed yet;
2739 * let's treat it like congestion or err < 0
2743 packet_increment_head(&po->tx_ring);
2745 } while (likely((ph != NULL) ||
2746 /* Note: packet_read_pending() might be slow if we have
2747 * to call it as it's per_cpu variable, but in fast-path
2748 * we already short-circuit the loop with the first
2749 * condition, and luckily don't have to go that path
2752 (need_wait && packet_read_pending(&po->tx_ring))));
2758 __packet_set_status(po, ph, status);
2763 mutex_unlock(&po->pg_vec_lock);
2767 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2768 size_t reserve, size_t len,
2769 size_t linear, int noblock,
2772 struct sk_buff *skb;
2774 /* Under a page? Don't bother with paged skb. */
2775 if (prepad + len < PAGE_SIZE || !linear)
2778 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2783 skb_reserve(skb, reserve);
2784 skb_put(skb, linear);
2785 skb->data_len = len - linear;
2786 skb->len += len - linear;
2791 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2793 struct sock *sk = sock->sk;
2794 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2795 struct sk_buff *skb;
2796 struct net_device *dev;
2798 unsigned char *addr;
2799 int err, reserve = 0;
2800 struct sockcm_cookie sockc;
2801 struct virtio_net_hdr vnet_hdr = { 0 };
2803 struct packet_sock *po = pkt_sk(sk);
2804 bool has_vnet_hdr = false;
2805 int hlen, tlen, linear;
2809 * Get and verify the address.
2812 if (likely(saddr == NULL)) {
2813 dev = packet_cached_dev_get(po);
2818 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2820 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2822 proto = saddr->sll_protocol;
2823 addr = saddr->sll_addr;
2824 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2828 if (unlikely(dev == NULL))
2831 if (unlikely(!(dev->flags & IFF_UP)))
2834 sockc.tsflags = sk->sk_tsflags;
2835 sockc.mark = sk->sk_mark;
2836 if (msg->msg_controllen) {
2837 err = sock_cmsg_send(sk, msg, &sockc);
2842 if (sock->type == SOCK_RAW)
2843 reserve = dev->hard_header_len;
2844 if (po->has_vnet_hdr) {
2845 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2848 has_vnet_hdr = true;
2851 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2852 if (!netif_supports_nofcs(dev)) {
2853 err = -EPROTONOSUPPORT;
2856 extra_len = 4; /* We're doing our own CRC */
2860 if (!vnet_hdr.gso_type &&
2861 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2865 hlen = LL_RESERVED_SPACE(dev);
2866 tlen = dev->needed_tailroom;
2867 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2868 linear = max(linear, min_t(int, len, dev->hard_header_len));
2869 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2870 msg->msg_flags & MSG_DONTWAIT, &err);
2874 skb_reset_network_header(skb);
2877 if (sock->type == SOCK_DGRAM) {
2878 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2879 if (unlikely(offset < 0))
2881 } else if (reserve) {
2882 skb_reserve(skb, -reserve);
2885 /* Returns -EFAULT on error */
2886 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2890 if (sock->type == SOCK_RAW &&
2891 !dev_validate_header(dev, skb->data, len)) {
2896 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
2898 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2899 !packet_extra_vlan_len_allowed(dev, skb)) {
2904 skb->protocol = proto;
2906 skb->priority = sk->sk_priority;
2907 skb->mark = sockc.mark;
2910 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2913 len += sizeof(vnet_hdr);
2916 skb_probe_transport_header(skb, reserve);
2918 if (unlikely(extra_len == 4))
2921 err = po->xmit(skb);
2922 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2938 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2940 struct sock *sk = sock->sk;
2941 struct packet_sock *po = pkt_sk(sk);
2943 if (po->tx_ring.pg_vec)
2944 return tpacket_snd(po, msg);
2946 return packet_snd(sock, msg, len);
2950 * Close a PACKET socket. This is fairly simple. We immediately go
2951 * to 'closed' state and remove our protocol entry in the device list.
2954 static int packet_release(struct socket *sock)
2956 struct sock *sk = sock->sk;
2957 struct packet_sock *po;
2958 struct packet_fanout *f;
2960 union tpacket_req_u req_u;
2968 mutex_lock(&net->packet.sklist_lock);
2969 sk_del_node_init_rcu(sk);
2970 mutex_unlock(&net->packet.sklist_lock);
2973 sock_prot_inuse_add(net, sk->sk_prot, -1);
2976 spin_lock(&po->bind_lock);
2977 unregister_prot_hook(sk, false);
2978 packet_cached_dev_reset(po);
2980 if (po->prot_hook.dev) {
2981 dev_put(po->prot_hook.dev);
2982 po->prot_hook.dev = NULL;
2984 spin_unlock(&po->bind_lock);
2986 packet_flush_mclist(sk);
2989 if (po->rx_ring.pg_vec) {
2990 memset(&req_u, 0, sizeof(req_u));
2991 packet_set_ring(sk, &req_u, 1, 0);
2994 if (po->tx_ring.pg_vec) {
2995 memset(&req_u, 0, sizeof(req_u));
2996 packet_set_ring(sk, &req_u, 1, 1);
3000 f = fanout_release(sk);
3005 kfree(po->rollover);
3006 fanout_release_data(f);
3010 * Now the socket is dead. No more input will appear.
3017 skb_queue_purge(&sk->sk_receive_queue);
3018 packet_free_pending(po);
3019 sk_refcnt_debug_release(sk);
3026 * Attach a packet hook.
3029 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3032 struct packet_sock *po = pkt_sk(sk);
3033 struct net_device *dev_curr;
3036 struct net_device *dev = NULL;
3038 bool unlisted = false;
3041 spin_lock(&po->bind_lock);
3050 dev = dev_get_by_name_rcu(sock_net(sk), name);
3055 } else if (ifindex) {
3056 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3066 proto_curr = po->prot_hook.type;
3067 dev_curr = po->prot_hook.dev;
3069 need_rehook = proto_curr != proto || dev_curr != dev;
3074 /* prevents packet_notifier() from calling
3075 * register_prot_hook()
3078 __unregister_prot_hook(sk, true);
3080 dev_curr = po->prot_hook.dev;
3082 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3086 BUG_ON(po->running);
3088 po->prot_hook.type = proto;
3090 if (unlikely(unlisted)) {
3092 po->prot_hook.dev = NULL;
3094 packet_cached_dev_reset(po);
3096 po->prot_hook.dev = dev;
3097 po->ifindex = dev ? dev->ifindex : 0;
3098 packet_cached_dev_assign(po, dev);
3104 if (proto == 0 || !need_rehook)
3107 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3108 register_prot_hook(sk);
3110 sk->sk_err = ENETDOWN;
3111 if (!sock_flag(sk, SOCK_DEAD))
3112 sk->sk_error_report(sk);
3117 spin_unlock(&po->bind_lock);
3123 * Bind a packet socket to a device
3126 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3129 struct sock *sk = sock->sk;
3130 char name[sizeof(uaddr->sa_data) + 1];
3136 if (addr_len != sizeof(struct sockaddr))
3138 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3141 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3142 name[sizeof(uaddr->sa_data)] = 0;
3144 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3147 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3149 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3150 struct sock *sk = sock->sk;
3156 if (addr_len < sizeof(struct sockaddr_ll))
3158 if (sll->sll_family != AF_PACKET)
3161 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3162 sll->sll_protocol ? : pkt_sk(sk)->num);
3165 static struct proto packet_proto = {
3167 .owner = THIS_MODULE,
3168 .obj_size = sizeof(struct packet_sock),
3172 * Create a packet of type SOCK_PACKET.
3175 static int packet_create(struct net *net, struct socket *sock, int protocol,
3179 struct packet_sock *po;
3180 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3183 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3185 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3186 sock->type != SOCK_PACKET)
3187 return -ESOCKTNOSUPPORT;
3189 sock->state = SS_UNCONNECTED;
3192 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3196 sock->ops = &packet_ops;
3197 if (sock->type == SOCK_PACKET)
3198 sock->ops = &packet_ops_spkt;
3200 sock_init_data(sock, sk);
3203 sk->sk_family = PF_PACKET;
3205 po->xmit = dev_queue_xmit;
3207 err = packet_alloc_pending(po);
3211 packet_cached_dev_reset(po);
3213 sk->sk_destruct = packet_sock_destruct;
3214 sk_refcnt_debug_inc(sk);
3217 * Attach a protocol block
3220 spin_lock_init(&po->bind_lock);
3221 mutex_init(&po->pg_vec_lock);
3222 po->rollover = NULL;
3223 po->prot_hook.func = packet_rcv;
3225 if (sock->type == SOCK_PACKET)
3226 po->prot_hook.func = packet_rcv_spkt;
3228 po->prot_hook.af_packet_priv = sk;
3231 po->prot_hook.type = proto;
3232 __register_prot_hook(sk);
3235 mutex_lock(&net->packet.sklist_lock);
3236 sk_add_node_rcu(sk, &net->packet.sklist);
3237 mutex_unlock(&net->packet.sklist_lock);
3240 sock_prot_inuse_add(net, &packet_proto, 1);
3251 * Pull a packet from our receive queue and hand it to the user.
3252 * If necessary we block.
3255 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3258 struct sock *sk = sock->sk;
3259 struct sk_buff *skb;
3261 int vnet_hdr_len = 0;
3262 unsigned int origlen = 0;
3265 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3269 /* What error should we return now? EUNATTACH? */
3270 if (pkt_sk(sk)->ifindex < 0)
3274 if (flags & MSG_ERRQUEUE) {
3275 err = sock_recv_errqueue(sk, msg, len,
3276 SOL_PACKET, PACKET_TX_TIMESTAMP);
3281 * Call the generic datagram receiver. This handles all sorts
3282 * of horrible races and re-entrancy so we can forget about it
3283 * in the protocol layers.
3285 * Now it will return ENETDOWN, if device have just gone down,
3286 * but then it will block.
3289 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3292 * An error occurred so return it. Because skb_recv_datagram()
3293 * handles the blocking we don't see and worry about blocking
3300 if (pkt_sk(sk)->pressure)
3301 packet_rcv_has_room(pkt_sk(sk), NULL);
3303 if (pkt_sk(sk)->has_vnet_hdr) {
3304 err = packet_rcv_vnet(msg, skb, &len);
3307 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3310 /* You lose any data beyond the buffer you gave. If it worries
3311 * a user program they can ask the device for its MTU
3317 msg->msg_flags |= MSG_TRUNC;
3320 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3324 if (sock->type != SOCK_PACKET) {
3325 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3327 /* Original length was stored in sockaddr_ll fields */
3328 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3329 sll->sll_family = AF_PACKET;
3330 sll->sll_protocol = skb->protocol;
3333 sock_recv_ts_and_drops(msg, sk, skb);
3335 if (msg->msg_name) {
3336 /* If the address length field is there to be filled
3337 * in, we fill it in now.
3339 if (sock->type == SOCK_PACKET) {
3340 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3341 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3343 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3345 msg->msg_namelen = sll->sll_halen +
3346 offsetof(struct sockaddr_ll, sll_addr);
3348 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3352 if (pkt_sk(sk)->auxdata) {
3353 struct tpacket_auxdata aux;
3355 aux.tp_status = TP_STATUS_USER;
3356 if (skb->ip_summed == CHECKSUM_PARTIAL)
3357 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3358 else if (skb->pkt_type != PACKET_OUTGOING &&
3359 (skb->ip_summed == CHECKSUM_COMPLETE ||
3360 skb_csum_unnecessary(skb)))
3361 aux.tp_status |= TP_STATUS_CSUM_VALID;
3363 aux.tp_len = origlen;
3364 aux.tp_snaplen = skb->len;
3366 aux.tp_net = skb_network_offset(skb);
3367 if (skb_vlan_tag_present(skb)) {
3368 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3369 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3370 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3372 aux.tp_vlan_tci = 0;
3373 aux.tp_vlan_tpid = 0;
3375 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3379 * Free or return the buffer as appropriate. Again this
3380 * hides all the races and re-entrancy issues from us.
3382 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3385 skb_free_datagram(sk, skb);
3390 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3393 struct net_device *dev;
3394 struct sock *sk = sock->sk;
3399 uaddr->sa_family = AF_PACKET;
3400 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3402 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3404 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3407 return sizeof(*uaddr);
3410 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3413 struct net_device *dev;
3414 struct sock *sk = sock->sk;
3415 struct packet_sock *po = pkt_sk(sk);
3416 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3421 sll->sll_family = AF_PACKET;
3422 sll->sll_ifindex = po->ifindex;
3423 sll->sll_protocol = po->num;
3424 sll->sll_pkttype = 0;
3426 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3428 sll->sll_hatype = dev->type;
3429 sll->sll_halen = dev->addr_len;
3430 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3432 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3437 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3440 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3444 case PACKET_MR_MULTICAST:
3445 if (i->alen != dev->addr_len)
3448 return dev_mc_add(dev, i->addr);
3450 return dev_mc_del(dev, i->addr);
3452 case PACKET_MR_PROMISC:
3453 return dev_set_promiscuity(dev, what);
3454 case PACKET_MR_ALLMULTI:
3455 return dev_set_allmulti(dev, what);
3456 case PACKET_MR_UNICAST:
3457 if (i->alen != dev->addr_len)
3460 return dev_uc_add(dev, i->addr);
3462 return dev_uc_del(dev, i->addr);
3470 static void packet_dev_mclist_delete(struct net_device *dev,
3471 struct packet_mclist **mlp)
3473 struct packet_mclist *ml;
3475 while ((ml = *mlp) != NULL) {
3476 if (ml->ifindex == dev->ifindex) {
3477 packet_dev_mc(dev, ml, -1);
3485 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3487 struct packet_sock *po = pkt_sk(sk);
3488 struct packet_mclist *ml, *i;
3489 struct net_device *dev;
3495 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3500 if (mreq->mr_alen > dev->addr_len)
3504 i = kmalloc(sizeof(*i), GFP_KERNEL);
3509 for (ml = po->mclist; ml; ml = ml->next) {
3510 if (ml->ifindex == mreq->mr_ifindex &&
3511 ml->type == mreq->mr_type &&
3512 ml->alen == mreq->mr_alen &&
3513 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3515 /* Free the new element ... */
3521 i->type = mreq->mr_type;
3522 i->ifindex = mreq->mr_ifindex;
3523 i->alen = mreq->mr_alen;
3524 memcpy(i->addr, mreq->mr_address, i->alen);
3525 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3527 i->next = po->mclist;
3529 err = packet_dev_mc(dev, i, 1);
3531 po->mclist = i->next;
3540 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3542 struct packet_mclist *ml, **mlp;
3546 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3547 if (ml->ifindex == mreq->mr_ifindex &&
3548 ml->type == mreq->mr_type &&
3549 ml->alen == mreq->mr_alen &&
3550 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3551 if (--ml->count == 0) {
3552 struct net_device *dev;
3554 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3556 packet_dev_mc(dev, ml, -1);
3566 static void packet_flush_mclist(struct sock *sk)
3568 struct packet_sock *po = pkt_sk(sk);
3569 struct packet_mclist *ml;
3575 while ((ml = po->mclist) != NULL) {
3576 struct net_device *dev;
3578 po->mclist = ml->next;
3579 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3581 packet_dev_mc(dev, ml, -1);
3588 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3590 struct sock *sk = sock->sk;
3591 struct packet_sock *po = pkt_sk(sk);
3594 if (level != SOL_PACKET)
3595 return -ENOPROTOOPT;
3598 case PACKET_ADD_MEMBERSHIP:
3599 case PACKET_DROP_MEMBERSHIP:
3601 struct packet_mreq_max mreq;
3603 memset(&mreq, 0, sizeof(mreq));
3604 if (len < sizeof(struct packet_mreq))
3606 if (len > sizeof(mreq))
3608 if (copy_from_user(&mreq, optval, len))
3610 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3612 if (optname == PACKET_ADD_MEMBERSHIP)
3613 ret = packet_mc_add(sk, &mreq);
3615 ret = packet_mc_drop(sk, &mreq);
3619 case PACKET_RX_RING:
3620 case PACKET_TX_RING:
3622 union tpacket_req_u req_u;
3626 switch (po->tp_version) {
3629 len = sizeof(req_u.req);
3633 len = sizeof(req_u.req3);
3639 if (copy_from_user(&req_u.req, optval, len))
3642 ret = packet_set_ring(sk, &req_u, 0,
3643 optname == PACKET_TX_RING);
3648 case PACKET_COPY_THRESH:
3652 if (optlen != sizeof(val))
3654 if (copy_from_user(&val, optval, sizeof(val)))
3657 pkt_sk(sk)->copy_thresh = val;
3660 case PACKET_VERSION:
3664 if (optlen != sizeof(val))
3666 if (copy_from_user(&val, optval, sizeof(val)))
3677 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3680 po->tp_version = val;
3686 case PACKET_RESERVE:
3690 if (optlen != sizeof(val))
3692 if (copy_from_user(&val, optval, sizeof(val)))
3697 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3700 po->tp_reserve = val;
3710 if (optlen != sizeof(val))
3712 if (copy_from_user(&val, optval, sizeof(val)))
3716 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3719 po->tp_loss = !!val;
3725 case PACKET_AUXDATA:
3729 if (optlen < sizeof(val))
3731 if (copy_from_user(&val, optval, sizeof(val)))
3735 po->auxdata = !!val;
3739 case PACKET_ORIGDEV:
3743 if (optlen < sizeof(val))
3745 if (copy_from_user(&val, optval, sizeof(val)))
3749 po->origdev = !!val;
3753 case PACKET_VNET_HDR:
3757 if (sock->type != SOCK_RAW)
3759 if (optlen < sizeof(val))
3761 if (copy_from_user(&val, optval, sizeof(val)))
3765 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3768 po->has_vnet_hdr = !!val;
3774 case PACKET_TIMESTAMP:
3778 if (optlen != sizeof(val))
3780 if (copy_from_user(&val, optval, sizeof(val)))
3783 po->tp_tstamp = val;
3790 if (optlen != sizeof(val))
3792 if (copy_from_user(&val, optval, sizeof(val)))
3795 return fanout_add(sk, val & 0xffff, val >> 16);
3797 case PACKET_FANOUT_DATA:
3802 return fanout_set_data(po, optval, optlen);
3804 case PACKET_TX_HAS_OFF:
3808 if (optlen != sizeof(val))
3810 if (copy_from_user(&val, optval, sizeof(val)))
3814 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3817 po->tp_tx_has_off = !!val;
3823 case PACKET_QDISC_BYPASS:
3827 if (optlen != sizeof(val))
3829 if (copy_from_user(&val, optval, sizeof(val)))
3832 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3836 return -ENOPROTOOPT;
3840 static int packet_getsockopt(struct socket *sock, int level, int optname,
3841 char __user *optval, int __user *optlen)
3844 int val, lv = sizeof(val);
3845 struct sock *sk = sock->sk;
3846 struct packet_sock *po = pkt_sk(sk);
3848 union tpacket_stats_u st;
3849 struct tpacket_rollover_stats rstats;
3851 if (level != SOL_PACKET)
3852 return -ENOPROTOOPT;
3854 if (get_user(len, optlen))
3861 case PACKET_STATISTICS:
3862 spin_lock_bh(&sk->sk_receive_queue.lock);
3863 memcpy(&st, &po->stats, sizeof(st));
3864 memset(&po->stats, 0, sizeof(po->stats));
3865 spin_unlock_bh(&sk->sk_receive_queue.lock);
3867 if (po->tp_version == TPACKET_V3) {
3868 lv = sizeof(struct tpacket_stats_v3);
3869 st.stats3.tp_packets += st.stats3.tp_drops;
3872 lv = sizeof(struct tpacket_stats);
3873 st.stats1.tp_packets += st.stats1.tp_drops;
3878 case PACKET_AUXDATA:
3881 case PACKET_ORIGDEV:
3884 case PACKET_VNET_HDR:
3885 val = po->has_vnet_hdr;
3887 case PACKET_VERSION:
3888 val = po->tp_version;
3891 if (len > sizeof(int))
3893 if (len < sizeof(int))
3895 if (copy_from_user(&val, optval, len))
3899 val = sizeof(struct tpacket_hdr);
3902 val = sizeof(struct tpacket2_hdr);
3905 val = sizeof(struct tpacket3_hdr);
3911 case PACKET_RESERVE:
3912 val = po->tp_reserve;
3917 case PACKET_TIMESTAMP:
3918 val = po->tp_tstamp;
3922 ((u32)po->fanout->id |
3923 ((u32)po->fanout->type << 16) |
3924 ((u32)po->fanout->flags << 24)) :
3927 case PACKET_ROLLOVER_STATS:
3930 rstats.tp_all = atomic_long_read(&po->rollover->num);
3931 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3932 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3934 lv = sizeof(rstats);
3936 case PACKET_TX_HAS_OFF:
3937 val = po->tp_tx_has_off;
3939 case PACKET_QDISC_BYPASS:
3940 val = packet_use_direct_xmit(po);
3943 return -ENOPROTOOPT;
3948 if (put_user(len, optlen))
3950 if (copy_to_user(optval, data, len))
3956 #ifdef CONFIG_COMPAT
3957 static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
3958 char __user *optval, unsigned int optlen)
3960 struct packet_sock *po = pkt_sk(sock->sk);
3962 if (level != SOL_PACKET)
3963 return -ENOPROTOOPT;
3965 if (optname == PACKET_FANOUT_DATA &&
3966 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
3967 optval = (char __user *)get_compat_bpf_fprog(optval);
3970 optlen = sizeof(struct sock_fprog);
3973 return packet_setsockopt(sock, level, optname, optval, optlen);
3977 static int packet_notifier(struct notifier_block *this,
3978 unsigned long msg, void *ptr)
3981 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3982 struct net *net = dev_net(dev);
3985 sk_for_each_rcu(sk, &net->packet.sklist) {
3986 struct packet_sock *po = pkt_sk(sk);
3989 case NETDEV_UNREGISTER:
3991 packet_dev_mclist_delete(dev, &po->mclist);
3995 if (dev->ifindex == po->ifindex) {
3996 spin_lock(&po->bind_lock);
3998 __unregister_prot_hook(sk, false);
3999 sk->sk_err = ENETDOWN;
4000 if (!sock_flag(sk, SOCK_DEAD))
4001 sk->sk_error_report(sk);
4003 if (msg == NETDEV_UNREGISTER) {
4004 packet_cached_dev_reset(po);
4006 if (po->prot_hook.dev)
4007 dev_put(po->prot_hook.dev);
4008 po->prot_hook.dev = NULL;
4010 spin_unlock(&po->bind_lock);
4014 if (dev->ifindex == po->ifindex) {
4015 spin_lock(&po->bind_lock);
4017 register_prot_hook(sk);
4018 spin_unlock(&po->bind_lock);
4028 static int packet_ioctl(struct socket *sock, unsigned int cmd,
4031 struct sock *sk = sock->sk;
4036 int amount = sk_wmem_alloc_get(sk);
4038 return put_user(amount, (int __user *)arg);
4042 struct sk_buff *skb;
4045 spin_lock_bh(&sk->sk_receive_queue.lock);
4046 skb = skb_peek(&sk->sk_receive_queue);
4049 spin_unlock_bh(&sk->sk_receive_queue.lock);
4050 return put_user(amount, (int __user *)arg);
4053 return sock_get_timestamp(sk, (struct timeval __user *)arg);
4055 return sock_get_timestampns(sk, (struct timespec __user *)arg);
4065 case SIOCGIFBRDADDR:
4066 case SIOCSIFBRDADDR:
4067 case SIOCGIFNETMASK:
4068 case SIOCSIFNETMASK:
4069 case SIOCGIFDSTADDR:
4070 case SIOCSIFDSTADDR:
4072 return inet_dgram_ops.ioctl(sock, cmd, arg);
4076 return -ENOIOCTLCMD;
4081 static __poll_t packet_poll_mask(struct socket *sock, __poll_t events)
4083 struct sock *sk = sock->sk;
4084 struct packet_sock *po = pkt_sk(sk);
4085 __poll_t mask = datagram_poll_mask(sock, events);
4087 spin_lock_bh(&sk->sk_receive_queue.lock);
4088 if (po->rx_ring.pg_vec) {
4089 if (!packet_previous_rx_frame(po, &po->rx_ring,
4091 mask |= EPOLLIN | EPOLLRDNORM;
4093 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
4095 spin_unlock_bh(&sk->sk_receive_queue.lock);
4096 spin_lock_bh(&sk->sk_write_queue.lock);
4097 if (po->tx_ring.pg_vec) {
4098 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4099 mask |= EPOLLOUT | EPOLLWRNORM;
4101 spin_unlock_bh(&sk->sk_write_queue.lock);
4106 /* Dirty? Well, I still did not learn better way to account
4110 static void packet_mm_open(struct vm_area_struct *vma)
4112 struct file *file = vma->vm_file;
4113 struct socket *sock = file->private_data;
4114 struct sock *sk = sock->sk;
4117 atomic_inc(&pkt_sk(sk)->mapped);
4120 static void packet_mm_close(struct vm_area_struct *vma)
4122 struct file *file = vma->vm_file;
4123 struct socket *sock = file->private_data;
4124 struct sock *sk = sock->sk;
4127 atomic_dec(&pkt_sk(sk)->mapped);
4130 static const struct vm_operations_struct packet_mmap_ops = {
4131 .open = packet_mm_open,
4132 .close = packet_mm_close,
4135 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4140 for (i = 0; i < len; i++) {
4141 if (likely(pg_vec[i].buffer)) {
4142 if (is_vmalloc_addr(pg_vec[i].buffer))
4143 vfree(pg_vec[i].buffer);
4145 free_pages((unsigned long)pg_vec[i].buffer,
4147 pg_vec[i].buffer = NULL;
4153 static char *alloc_one_pg_vec_page(unsigned long order)
4156 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4157 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4159 buffer = (char *) __get_free_pages(gfp_flags, order);
4163 /* __get_free_pages failed, fall back to vmalloc */
4164 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4168 /* vmalloc failed, lets dig into swap here */
4169 gfp_flags &= ~__GFP_NORETRY;
4170 buffer = (char *) __get_free_pages(gfp_flags, order);
4174 /* complete and utter failure */
4178 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4180 unsigned int block_nr = req->tp_block_nr;
4184 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4185 if (unlikely(!pg_vec))
4188 for (i = 0; i < block_nr; i++) {
4189 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4190 if (unlikely(!pg_vec[i].buffer))
4191 goto out_free_pgvec;
4198 free_pg_vec(pg_vec, order, block_nr);
4203 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4204 int closing, int tx_ring)
4206 struct pgv *pg_vec = NULL;
4207 struct packet_sock *po = pkt_sk(sk);
4208 int was_running, order = 0;
4209 struct packet_ring_buffer *rb;
4210 struct sk_buff_head *rb_queue;
4213 /* Added to avoid minimal code churn */
4214 struct tpacket_req *req = &req_u->req;
4216 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4217 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4221 if (atomic_read(&po->mapped))
4223 if (packet_read_pending(rb))
4227 if (req->tp_block_nr) {
4228 /* Sanity tests and some calculations */
4230 if (unlikely(rb->pg_vec))
4233 switch (po->tp_version) {
4235 po->tp_hdrlen = TPACKET_HDRLEN;
4238 po->tp_hdrlen = TPACKET2_HDRLEN;
4241 po->tp_hdrlen = TPACKET3_HDRLEN;
4246 if (unlikely((int)req->tp_block_size <= 0))
4248 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4250 if (po->tp_version >= TPACKET_V3 &&
4251 req->tp_block_size <=
4252 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + sizeof(struct tpacket3_hdr))
4254 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4257 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4260 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4261 if (unlikely(rb->frames_per_block == 0))
4263 if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
4265 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4270 order = get_order(req->tp_block_size);
4271 pg_vec = alloc_pg_vec(req, order);
4272 if (unlikely(!pg_vec))
4274 switch (po->tp_version) {
4276 /* Block transmit is not supported yet */
4278 init_prb_bdqc(po, rb, pg_vec, req_u);
4280 struct tpacket_req3 *req3 = &req_u->req3;
4282 if (req3->tp_retire_blk_tov ||
4283 req3->tp_sizeof_priv ||
4284 req3->tp_feature_req_word) {
4297 if (unlikely(req->tp_frame_nr))
4302 /* Detach socket from network */
4303 spin_lock(&po->bind_lock);
4304 was_running = po->running;
4308 __unregister_prot_hook(sk, false);
4310 spin_unlock(&po->bind_lock);
4315 mutex_lock(&po->pg_vec_lock);
4316 if (closing || atomic_read(&po->mapped) == 0) {
4318 spin_lock_bh(&rb_queue->lock);
4319 swap(rb->pg_vec, pg_vec);
4320 rb->frame_max = (req->tp_frame_nr - 1);
4322 rb->frame_size = req->tp_frame_size;
4323 spin_unlock_bh(&rb_queue->lock);
4325 swap(rb->pg_vec_order, order);
4326 swap(rb->pg_vec_len, req->tp_block_nr);
4328 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4329 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4330 tpacket_rcv : packet_rcv;
4331 skb_queue_purge(rb_queue);
4332 if (atomic_read(&po->mapped))
4333 pr_err("packet_mmap: vma is busy: %d\n",
4334 atomic_read(&po->mapped));
4336 mutex_unlock(&po->pg_vec_lock);
4338 spin_lock(&po->bind_lock);
4341 register_prot_hook(sk);
4343 spin_unlock(&po->bind_lock);
4344 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4345 /* Because we don't support block-based V3 on tx-ring */
4347 prb_shutdown_retire_blk_timer(po, rb_queue);
4351 free_pg_vec(pg_vec, order, req->tp_block_nr);
4356 static int packet_mmap(struct file *file, struct socket *sock,
4357 struct vm_area_struct *vma)
4359 struct sock *sk = sock->sk;
4360 struct packet_sock *po = pkt_sk(sk);
4361 unsigned long size, expected_size;
4362 struct packet_ring_buffer *rb;
4363 unsigned long start;
4370 mutex_lock(&po->pg_vec_lock);
4373 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4375 expected_size += rb->pg_vec_len
4381 if (expected_size == 0)
4384 size = vma->vm_end - vma->vm_start;
4385 if (size != expected_size)
4388 start = vma->vm_start;
4389 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4390 if (rb->pg_vec == NULL)
4393 for (i = 0; i < rb->pg_vec_len; i++) {
4395 void *kaddr = rb->pg_vec[i].buffer;
4398 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4399 page = pgv_to_page(kaddr);
4400 err = vm_insert_page(vma, start, page);
4409 atomic_inc(&po->mapped);
4410 vma->vm_ops = &packet_mmap_ops;
4414 mutex_unlock(&po->pg_vec_lock);
4418 static const struct proto_ops packet_ops_spkt = {
4419 .family = PF_PACKET,
4420 .owner = THIS_MODULE,
4421 .release = packet_release,
4422 .bind = packet_bind_spkt,
4423 .connect = sock_no_connect,
4424 .socketpair = sock_no_socketpair,
4425 .accept = sock_no_accept,
4426 .getname = packet_getname_spkt,
4427 .poll_mask = datagram_poll_mask,
4428 .ioctl = packet_ioctl,
4429 .listen = sock_no_listen,
4430 .shutdown = sock_no_shutdown,
4431 .setsockopt = sock_no_setsockopt,
4432 .getsockopt = sock_no_getsockopt,
4433 .sendmsg = packet_sendmsg_spkt,
4434 .recvmsg = packet_recvmsg,
4435 .mmap = sock_no_mmap,
4436 .sendpage = sock_no_sendpage,
4439 static const struct proto_ops packet_ops = {
4440 .family = PF_PACKET,
4441 .owner = THIS_MODULE,
4442 .release = packet_release,
4443 .bind = packet_bind,
4444 .connect = sock_no_connect,
4445 .socketpair = sock_no_socketpair,
4446 .accept = sock_no_accept,
4447 .getname = packet_getname,
4448 .poll_mask = packet_poll_mask,
4449 .ioctl = packet_ioctl,
4450 .listen = sock_no_listen,
4451 .shutdown = sock_no_shutdown,
4452 .setsockopt = packet_setsockopt,
4453 .getsockopt = packet_getsockopt,
4454 #ifdef CONFIG_COMPAT
4455 .compat_setsockopt = compat_packet_setsockopt,
4457 .sendmsg = packet_sendmsg,
4458 .recvmsg = packet_recvmsg,
4459 .mmap = packet_mmap,
4460 .sendpage = sock_no_sendpage,
4463 static const struct net_proto_family packet_family_ops = {
4464 .family = PF_PACKET,
4465 .create = packet_create,
4466 .owner = THIS_MODULE,
4469 static struct notifier_block packet_netdev_notifier = {
4470 .notifier_call = packet_notifier,
4473 #ifdef CONFIG_PROC_FS
4475 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4478 struct net *net = seq_file_net(seq);
4481 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4484 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4486 struct net *net = seq_file_net(seq);
4487 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4490 static void packet_seq_stop(struct seq_file *seq, void *v)
4496 static int packet_seq_show(struct seq_file *seq, void *v)
4498 if (v == SEQ_START_TOKEN)
4499 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4501 struct sock *s = sk_entry(v);
4502 const struct packet_sock *po = pkt_sk(s);
4505 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4507 refcount_read(&s->sk_refcnt),
4512 atomic_read(&s->sk_rmem_alloc),
4513 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4520 static const struct seq_operations packet_seq_ops = {
4521 .start = packet_seq_start,
4522 .next = packet_seq_next,
4523 .stop = packet_seq_stop,
4524 .show = packet_seq_show,
4528 static int __net_init packet_net_init(struct net *net)
4530 mutex_init(&net->packet.sklist_lock);
4531 INIT_HLIST_HEAD(&net->packet.sklist);
4533 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4534 sizeof(struct seq_net_private)))
4540 static void __net_exit packet_net_exit(struct net *net)
4542 remove_proc_entry("packet", net->proc_net);
4543 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4546 static struct pernet_operations packet_net_ops = {
4547 .init = packet_net_init,
4548 .exit = packet_net_exit,
4552 static void __exit packet_exit(void)
4554 unregister_netdevice_notifier(&packet_netdev_notifier);
4555 unregister_pernet_subsys(&packet_net_ops);
4556 sock_unregister(PF_PACKET);
4557 proto_unregister(&packet_proto);
4560 static int __init packet_init(void)
4562 int rc = proto_register(&packet_proto, 0);
4567 sock_register(&packet_family_ops);
4568 register_pernet_subsys(&packet_net_ops);
4569 register_netdevice_notifier(&packet_netdev_notifier);
4574 module_init(packet_init);
4575 module_exit(packet_exit);
4576 MODULE_LICENSE("GPL");
4577 MODULE_ALIAS_NETPROTO(PF_PACKET);