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/delay.h>
67 #include <linux/kmod.h>
68 #include <linux/slab.h>
69 #include <linux/vmalloc.h>
70 #include <net/net_namespace.h>
72 #include <net/protocol.h>
73 #include <linux/skbuff.h>
75 #include <linux/errno.h>
76 #include <linux/timer.h>
77 #include <asm/uaccess.h>
78 #include <asm/ioctls.h>
80 #include <asm/cacheflush.h>
82 #include <linux/proc_fs.h>
83 #include <linux/seq_file.h>
84 #include <linux/poll.h>
85 #include <linux/module.h>
86 #include <linux/init.h>
87 #include <linux/mutex.h>
88 #include <linux/if_vlan.h>
89 #include <linux/virtio_net.h>
90 #include <linux/errqueue.h>
91 #include <linux/net_tstamp.h>
92 #include <linux/percpu.h>
94 #include <net/inet_common.h>
96 #include <linux/bpf.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 PGV_FROM_VMALLOC 1
182 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
183 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
184 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
185 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
186 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
187 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
188 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
191 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
192 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
193 struct packet_type *pt, struct net_device *orig_dev);
195 static void *packet_previous_frame(struct packet_sock *po,
196 struct packet_ring_buffer *rb,
198 static void packet_increment_head(struct packet_ring_buffer *buff);
199 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
200 struct tpacket_block_desc *);
201 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
202 struct packet_sock *);
203 static void prb_retire_current_block(struct tpacket_kbdq_core *,
204 struct packet_sock *, unsigned int status);
205 static int prb_queue_frozen(struct tpacket_kbdq_core *);
206 static void prb_open_block(struct tpacket_kbdq_core *,
207 struct tpacket_block_desc *);
208 static void prb_retire_rx_blk_timer_expired(unsigned long);
209 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
210 static void prb_init_blk_timer(struct packet_sock *,
211 struct tpacket_kbdq_core *,
212 void (*func) (unsigned long));
213 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
214 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
215 struct tpacket3_hdr *);
216 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
217 struct tpacket3_hdr *);
218 static void packet_flush_mclist(struct sock *sk);
220 struct packet_skb_cb {
222 struct sockaddr_pkt pkt;
224 /* Trick: alias skb original length with
225 * ll.sll_family and ll.protocol in order
228 unsigned int origlen;
229 struct sockaddr_ll ll;
234 #define vio_le() virtio_legacy_is_little_endian()
236 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
238 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
239 #define GET_PBLOCK_DESC(x, bid) \
240 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
241 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
242 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
243 #define GET_NEXT_PRB_BLK_NUM(x) \
244 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
245 ((x)->kactive_blk_num+1) : 0)
247 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
248 static void __fanout_link(struct sock *sk, struct packet_sock *po);
250 static int packet_direct_xmit(struct sk_buff *skb)
252 struct net_device *dev = skb->dev;
253 struct sk_buff *orig_skb = skb;
254 struct netdev_queue *txq;
255 int ret = NETDEV_TX_BUSY;
257 if (unlikely(!netif_running(dev) ||
258 !netif_carrier_ok(dev)))
261 skb = validate_xmit_skb_list(skb, dev);
265 txq = skb_get_tx_queue(dev, skb);
269 HARD_TX_LOCK(dev, txq, smp_processor_id());
270 if (!netif_xmit_frozen_or_drv_stopped(txq))
271 ret = netdev_start_xmit(skb, dev, txq, false);
272 HARD_TX_UNLOCK(dev, txq);
276 if (!dev_xmit_complete(ret))
281 atomic_long_inc(&dev->tx_dropped);
283 return NET_XMIT_DROP;
286 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
288 struct net_device *dev;
291 dev = rcu_dereference(po->cached_dev);
299 static void packet_cached_dev_assign(struct packet_sock *po,
300 struct net_device *dev)
302 rcu_assign_pointer(po->cached_dev, dev);
305 static void packet_cached_dev_reset(struct packet_sock *po)
307 RCU_INIT_POINTER(po->cached_dev, NULL);
310 static bool packet_use_direct_xmit(const struct packet_sock *po)
312 return po->xmit == packet_direct_xmit;
315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
317 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
322 const struct net_device_ops *ops = dev->netdev_ops;
325 if (ops->ndo_select_queue) {
326 queue_index = ops->ndo_select_queue(dev, skb, NULL,
327 __packet_pick_tx_queue);
328 queue_index = netdev_cap_txqueue(dev, queue_index);
330 queue_index = __packet_pick_tx_queue(dev, skb);
333 skb_set_queue_mapping(skb, queue_index);
336 /* register_prot_hook must be invoked with the po->bind_lock held,
337 * or from a context in which asynchronous accesses to the packet
338 * socket is not possible (packet_create()).
340 static void register_prot_hook(struct sock *sk)
342 struct packet_sock *po = pkt_sk(sk);
346 __fanout_link(sk, po);
348 dev_add_pack(&po->prot_hook);
355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
356 * held. If the sync parameter is true, we will temporarily drop
357 * the po->bind_lock and do a synchronize_net to make sure no
358 * asynchronous packet processing paths still refer to the elements
359 * of po->prot_hook. If the sync parameter is false, it is the
360 * callers responsibility to take care of this.
362 static void __unregister_prot_hook(struct sock *sk, bool sync)
364 struct packet_sock *po = pkt_sk(sk);
369 __fanout_unlink(sk, po);
371 __dev_remove_pack(&po->prot_hook);
376 spin_unlock(&po->bind_lock);
378 spin_lock(&po->bind_lock);
382 static void unregister_prot_hook(struct sock *sk, bool sync)
384 struct packet_sock *po = pkt_sk(sk);
387 __unregister_prot_hook(sk, sync);
390 static inline struct page * __pure pgv_to_page(void *addr)
392 if (is_vmalloc_addr(addr))
393 return vmalloc_to_page(addr);
394 return virt_to_page(addr);
397 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
399 union tpacket_uhdr h;
402 switch (po->tp_version) {
404 h.h1->tp_status = status;
405 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
408 h.h2->tp_status = status;
409 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
413 WARN(1, "TPACKET version not supported.\n");
420 static int __packet_get_status(struct packet_sock *po, void *frame)
422 union tpacket_uhdr h;
427 switch (po->tp_version) {
429 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
430 return h.h1->tp_status;
432 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
433 return h.h2->tp_status;
436 WARN(1, "TPACKET version not supported.\n");
442 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
445 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
448 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
449 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
450 return TP_STATUS_TS_RAW_HARDWARE;
452 if (ktime_to_timespec_cond(skb->tstamp, ts))
453 return TP_STATUS_TS_SOFTWARE;
458 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
461 union tpacket_uhdr h;
465 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
469 switch (po->tp_version) {
471 h.h1->tp_sec = ts.tv_sec;
472 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
475 h.h2->tp_sec = ts.tv_sec;
476 h.h2->tp_nsec = ts.tv_nsec;
480 WARN(1, "TPACKET version not supported.\n");
484 /* one flush is safe, as both fields always lie on the same cacheline */
485 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
491 static void *packet_lookup_frame(struct packet_sock *po,
492 struct packet_ring_buffer *rb,
493 unsigned int position,
496 unsigned int pg_vec_pos, frame_offset;
497 union tpacket_uhdr h;
499 pg_vec_pos = position / rb->frames_per_block;
500 frame_offset = position % rb->frames_per_block;
502 h.raw = rb->pg_vec[pg_vec_pos].buffer +
503 (frame_offset * rb->frame_size);
505 if (status != __packet_get_status(po, h.raw))
511 static void *packet_current_frame(struct packet_sock *po,
512 struct packet_ring_buffer *rb,
515 return packet_lookup_frame(po, rb, rb->head, status);
518 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
520 del_timer_sync(&pkc->retire_blk_timer);
523 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
524 struct sk_buff_head *rb_queue)
526 struct tpacket_kbdq_core *pkc;
528 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
530 spin_lock_bh(&rb_queue->lock);
531 pkc->delete_blk_timer = 1;
532 spin_unlock_bh(&rb_queue->lock);
534 prb_del_retire_blk_timer(pkc);
537 static void prb_init_blk_timer(struct packet_sock *po,
538 struct tpacket_kbdq_core *pkc,
539 void (*func) (unsigned long))
541 init_timer(&pkc->retire_blk_timer);
542 pkc->retire_blk_timer.data = (long)po;
543 pkc->retire_blk_timer.function = func;
544 pkc->retire_blk_timer.expires = jiffies;
547 static void prb_setup_retire_blk_timer(struct packet_sock *po)
549 struct tpacket_kbdq_core *pkc;
551 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
552 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
555 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
556 int blk_size_in_bytes)
558 struct net_device *dev;
559 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
560 struct ethtool_cmd ecmd;
565 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
566 if (unlikely(!dev)) {
568 return DEFAULT_PRB_RETIRE_TOV;
570 err = __ethtool_get_settings(dev, &ecmd);
571 speed = ethtool_cmd_speed(&ecmd);
575 * If the link speed is so slow you don't really
576 * need to worry about perf anyways
578 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
579 return DEFAULT_PRB_RETIRE_TOV;
586 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
598 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
599 union tpacket_req_u *req_u)
601 p1->feature_req_word = req_u->req3.tp_feature_req_word;
604 static void init_prb_bdqc(struct packet_sock *po,
605 struct packet_ring_buffer *rb,
607 union tpacket_req_u *req_u)
609 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
610 struct tpacket_block_desc *pbd;
612 memset(p1, 0x0, sizeof(*p1));
614 p1->knxt_seq_num = 1;
616 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
617 p1->pkblk_start = pg_vec[0].buffer;
618 p1->kblk_size = req_u->req3.tp_block_size;
619 p1->knum_blocks = req_u->req3.tp_block_nr;
620 p1->hdrlen = po->tp_hdrlen;
621 p1->version = po->tp_version;
622 p1->last_kactive_blk_num = 0;
623 po->stats.stats3.tp_freeze_q_cnt = 0;
624 if (req_u->req3.tp_retire_blk_tov)
625 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
627 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
628 req_u->req3.tp_block_size);
629 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
630 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
632 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
633 prb_init_ft_ops(p1, req_u);
634 prb_setup_retire_blk_timer(po);
635 prb_open_block(p1, pbd);
638 /* Do NOT update the last_blk_num first.
639 * Assumes sk_buff_head lock is held.
641 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
643 mod_timer(&pkc->retire_blk_timer,
644 jiffies + pkc->tov_in_jiffies);
645 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
650 * 1) We refresh the timer only when we open a block.
651 * By doing this we don't waste cycles refreshing the timer
652 * on packet-by-packet basis.
654 * With a 1MB block-size, on a 1Gbps line, it will take
655 * i) ~8 ms to fill a block + ii) memcpy etc.
656 * In this cut we are not accounting for the memcpy time.
658 * So, if the user sets the 'tmo' to 10ms then the timer
659 * will never fire while the block is still getting filled
660 * (which is what we want). However, the user could choose
661 * to close a block early and that's fine.
663 * But when the timer does fire, we check whether or not to refresh it.
664 * Since the tmo granularity is in msecs, it is not too expensive
665 * to refresh the timer, lets say every '8' msecs.
666 * Either the user can set the 'tmo' or we can derive it based on
667 * a) line-speed and b) block-size.
668 * prb_calc_retire_blk_tmo() calculates the tmo.
671 static void prb_retire_rx_blk_timer_expired(unsigned long data)
673 struct packet_sock *po = (struct packet_sock *)data;
674 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
676 struct tpacket_block_desc *pbd;
678 spin_lock(&po->sk.sk_receive_queue.lock);
680 frozen = prb_queue_frozen(pkc);
681 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
683 if (unlikely(pkc->delete_blk_timer))
686 /* We only need to plug the race when the block is partially filled.
688 * lock(); increment BLOCK_NUM_PKTS; unlock()
689 * copy_bits() is in progress ...
690 * timer fires on other cpu:
691 * we can't retire the current block because copy_bits
695 if (BLOCK_NUM_PKTS(pbd)) {
696 while (atomic_read(&pkc->blk_fill_in_prog)) {
697 /* Waiting for skb_copy_bits to finish... */
702 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
704 if (!BLOCK_NUM_PKTS(pbd)) {
705 /* An empty block. Just refresh the timer. */
708 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
709 if (!prb_dispatch_next_block(pkc, po))
714 /* Case 1. Queue was frozen because user-space was
717 if (prb_curr_blk_in_use(pkc, pbd)) {
719 * Ok, user-space is still behind.
720 * So just refresh the timer.
724 /* Case 2. queue was frozen,user-space caught up,
725 * now the link went idle && the timer fired.
726 * We don't have a block to close.So we open this
727 * block and restart the timer.
728 * opening a block thaws the queue,restarts timer
729 * Thawing/timer-refresh is a side effect.
731 prb_open_block(pkc, pbd);
738 _prb_refresh_rx_retire_blk_timer(pkc);
741 spin_unlock(&po->sk.sk_receive_queue.lock);
744 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
745 struct tpacket_block_desc *pbd1, __u32 status)
747 /* Flush everything minus the block header */
749 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
754 /* Skip the block header(we know header WILL fit in 4K) */
757 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
758 for (; start < end; start += PAGE_SIZE)
759 flush_dcache_page(pgv_to_page(start));
764 /* Now update the block status. */
766 BLOCK_STATUS(pbd1) = status;
768 /* Flush the block header */
770 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
772 flush_dcache_page(pgv_to_page(start));
782 * 2) Increment active_blk_num
784 * Note:We DONT refresh the timer on purpose.
785 * Because almost always the next block will be opened.
787 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
788 struct tpacket_block_desc *pbd1,
789 struct packet_sock *po, unsigned int stat)
791 __u32 status = TP_STATUS_USER | stat;
793 struct tpacket3_hdr *last_pkt;
794 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
795 struct sock *sk = &po->sk;
797 if (po->stats.stats3.tp_drops)
798 status |= TP_STATUS_LOSING;
800 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
801 last_pkt->tp_next_offset = 0;
803 /* Get the ts of the last pkt */
804 if (BLOCK_NUM_PKTS(pbd1)) {
805 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
806 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
808 /* Ok, we tmo'd - so get the current time.
810 * It shouldn't really happen as we don't close empty
811 * blocks. See prb_retire_rx_blk_timer_expired().
815 h1->ts_last_pkt.ts_sec = ts.tv_sec;
816 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
821 /* Flush the block */
822 prb_flush_block(pkc1, pbd1, status);
824 sk->sk_data_ready(sk);
826 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
829 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
831 pkc->reset_pending_on_curr_blk = 0;
835 * Side effect of opening a block:
837 * 1) prb_queue is thawed.
838 * 2) retire_blk_timer is refreshed.
841 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
842 struct tpacket_block_desc *pbd1)
845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
849 /* We could have just memset this but we will lose the
850 * flexibility of making the priv area sticky
853 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
854 BLOCK_NUM_PKTS(pbd1) = 0;
855 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
859 h1->ts_first_pkt.ts_sec = ts.tv_sec;
860 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
862 pkc1->pkblk_start = (char *)pbd1;
863 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
865 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
866 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
868 pbd1->version = pkc1->version;
869 pkc1->prev = pkc1->nxt_offset;
870 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
872 prb_thaw_queue(pkc1);
873 _prb_refresh_rx_retire_blk_timer(pkc1);
879 * Queue freeze logic:
880 * 1) Assume tp_block_nr = 8 blocks.
881 * 2) At time 't0', user opens Rx ring.
882 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
883 * 4) user-space is either sleeping or processing block '0'.
884 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
885 * it will close block-7,loop around and try to fill block '0'.
887 * __packet_lookup_frame_in_block
888 * prb_retire_current_block()
889 * prb_dispatch_next_block()
890 * |->(BLOCK_STATUS == USER) evaluates to true
891 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
892 * 6) Now there are two cases:
893 * 6.1) Link goes idle right after the queue is frozen.
894 * But remember, the last open_block() refreshed the timer.
895 * When this timer expires,it will refresh itself so that we can
896 * re-open block-0 in near future.
897 * 6.2) Link is busy and keeps on receiving packets. This is a simple
898 * case and __packet_lookup_frame_in_block will check if block-0
899 * is free and can now be re-used.
901 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
902 struct packet_sock *po)
904 pkc->reset_pending_on_curr_blk = 1;
905 po->stats.stats3.tp_freeze_q_cnt++;
908 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
911 * If the next block is free then we will dispatch it
912 * and return a good offset.
913 * Else, we will freeze the queue.
914 * So, caller must check the return value.
916 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
917 struct packet_sock *po)
919 struct tpacket_block_desc *pbd;
923 /* 1. Get current block num */
924 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
926 /* 2. If this block is currently in_use then freeze the queue */
927 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
928 prb_freeze_queue(pkc, po);
934 * open this block and return the offset where the first packet
935 * needs to get stored.
937 prb_open_block(pkc, pbd);
938 return (void *)pkc->nxt_offset;
941 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
942 struct packet_sock *po, unsigned int status)
944 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
946 /* retire/close the current block */
947 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
949 * Plug the case where copy_bits() is in progress on
950 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
951 * have space to copy the pkt in the current block and
952 * called prb_retire_current_block()
954 * We don't need to worry about the TMO case because
955 * the timer-handler already handled this case.
957 if (!(status & TP_STATUS_BLK_TMO)) {
958 while (atomic_read(&pkc->blk_fill_in_prog)) {
959 /* Waiting for skb_copy_bits to finish... */
963 prb_close_block(pkc, pbd, po, status);
968 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
969 struct tpacket_block_desc *pbd)
971 return TP_STATUS_USER & BLOCK_STATUS(pbd);
974 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
976 return pkc->reset_pending_on_curr_blk;
979 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
981 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
982 atomic_dec(&pkc->blk_fill_in_prog);
985 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
986 struct tpacket3_hdr *ppd)
988 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
991 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
992 struct tpacket3_hdr *ppd)
994 ppd->hv1.tp_rxhash = 0;
997 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
998 struct tpacket3_hdr *ppd)
1000 if (skb_vlan_tag_present(pkc->skb)) {
1001 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1002 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1003 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1005 ppd->hv1.tp_vlan_tci = 0;
1006 ppd->hv1.tp_vlan_tpid = 0;
1007 ppd->tp_status = TP_STATUS_AVAILABLE;
1011 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1012 struct tpacket3_hdr *ppd)
1014 ppd->hv1.tp_padding = 0;
1015 prb_fill_vlan_info(pkc, ppd);
1017 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1018 prb_fill_rxhash(pkc, ppd);
1020 prb_clear_rxhash(pkc, ppd);
1023 static void prb_fill_curr_block(char *curr,
1024 struct tpacket_kbdq_core *pkc,
1025 struct tpacket_block_desc *pbd,
1028 struct tpacket3_hdr *ppd;
1030 ppd = (struct tpacket3_hdr *)curr;
1031 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1033 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1034 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1035 BLOCK_NUM_PKTS(pbd) += 1;
1036 atomic_inc(&pkc->blk_fill_in_prog);
1037 prb_run_all_ft_ops(pkc, ppd);
1040 /* Assumes caller has the sk->rx_queue.lock */
1041 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1042 struct sk_buff *skb,
1047 struct tpacket_kbdq_core *pkc;
1048 struct tpacket_block_desc *pbd;
1051 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1052 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1054 /* Queue is frozen when user space is lagging behind */
1055 if (prb_queue_frozen(pkc)) {
1057 * Check if that last block which caused the queue to freeze,
1058 * is still in_use by user-space.
1060 if (prb_curr_blk_in_use(pkc, pbd)) {
1061 /* Can't record this packet */
1065 * Ok, the block was released by user-space.
1066 * Now let's open that block.
1067 * opening a block also thaws the queue.
1068 * Thawing is a side effect.
1070 prb_open_block(pkc, pbd);
1075 curr = pkc->nxt_offset;
1077 end = (char *)pbd + pkc->kblk_size;
1079 /* first try the current block */
1080 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1081 prb_fill_curr_block(curr, pkc, pbd, len);
1082 return (void *)curr;
1085 /* Ok, close the current block */
1086 prb_retire_current_block(pkc, po, 0);
1088 /* Now, try to dispatch the next block */
1089 curr = (char *)prb_dispatch_next_block(pkc, po);
1091 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1092 prb_fill_curr_block(curr, pkc, pbd, len);
1093 return (void *)curr;
1097 * No free blocks are available.user_space hasn't caught up yet.
1098 * Queue was just frozen and now this packet will get dropped.
1103 static void *packet_current_rx_frame(struct packet_sock *po,
1104 struct sk_buff *skb,
1105 int status, unsigned int len)
1108 switch (po->tp_version) {
1111 curr = packet_lookup_frame(po, &po->rx_ring,
1112 po->rx_ring.head, status);
1115 return __packet_lookup_frame_in_block(po, skb, status, len);
1117 WARN(1, "TPACKET version not supported\n");
1123 static void *prb_lookup_block(struct packet_sock *po,
1124 struct packet_ring_buffer *rb,
1128 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1129 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1131 if (status != BLOCK_STATUS(pbd))
1136 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1139 if (rb->prb_bdqc.kactive_blk_num)
1140 prev = rb->prb_bdqc.kactive_blk_num-1;
1142 prev = rb->prb_bdqc.knum_blocks-1;
1146 /* Assumes caller has held the rx_queue.lock */
1147 static void *__prb_previous_block(struct packet_sock *po,
1148 struct packet_ring_buffer *rb,
1151 unsigned int previous = prb_previous_blk_num(rb);
1152 return prb_lookup_block(po, rb, previous, status);
1155 static void *packet_previous_rx_frame(struct packet_sock *po,
1156 struct packet_ring_buffer *rb,
1159 if (po->tp_version <= TPACKET_V2)
1160 return packet_previous_frame(po, rb, status);
1162 return __prb_previous_block(po, rb, status);
1165 static void packet_increment_rx_head(struct packet_sock *po,
1166 struct packet_ring_buffer *rb)
1168 switch (po->tp_version) {
1171 return packet_increment_head(rb);
1174 WARN(1, "TPACKET version not supported.\n");
1180 static void *packet_previous_frame(struct packet_sock *po,
1181 struct packet_ring_buffer *rb,
1184 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1185 return packet_lookup_frame(po, rb, previous, status);
1188 static void packet_increment_head(struct packet_ring_buffer *buff)
1190 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1193 static void packet_inc_pending(struct packet_ring_buffer *rb)
1195 this_cpu_inc(*rb->pending_refcnt);
1198 static void packet_dec_pending(struct packet_ring_buffer *rb)
1200 this_cpu_dec(*rb->pending_refcnt);
1203 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1205 unsigned int refcnt = 0;
1208 /* We don't use pending refcount in rx_ring. */
1209 if (rb->pending_refcnt == NULL)
1212 for_each_possible_cpu(cpu)
1213 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1218 static int packet_alloc_pending(struct packet_sock *po)
1220 po->rx_ring.pending_refcnt = NULL;
1222 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1223 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1229 static void packet_free_pending(struct packet_sock *po)
1231 free_percpu(po->tx_ring.pending_refcnt);
1234 #define ROOM_POW_OFF 2
1235 #define ROOM_NONE 0x0
1236 #define ROOM_LOW 0x1
1237 #define ROOM_NORMAL 0x2
1239 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1243 len = po->rx_ring.frame_max + 1;
1244 idx = po->rx_ring.head;
1246 idx += len >> pow_off;
1249 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1252 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1256 len = po->rx_ring.prb_bdqc.knum_blocks;
1257 idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1259 idx += len >> pow_off;
1262 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1265 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1267 struct sock *sk = &po->sk;
1268 int ret = ROOM_NONE;
1270 if (po->prot_hook.func != tpacket_rcv) {
1271 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1272 - (skb ? skb->truesize : 0);
1273 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1281 if (po->tp_version == TPACKET_V3) {
1282 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1284 else if (__tpacket_v3_has_room(po, 0))
1287 if (__tpacket_has_room(po, ROOM_POW_OFF))
1289 else if (__tpacket_has_room(po, 0))
1296 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1301 spin_lock_bh(&po->sk.sk_receive_queue.lock);
1302 ret = __packet_rcv_has_room(po, skb);
1303 has_room = ret == ROOM_NORMAL;
1304 if (po->pressure == has_room)
1305 po->pressure = !has_room;
1306 spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1311 static void packet_sock_destruct(struct sock *sk)
1313 skb_queue_purge(&sk->sk_error_queue);
1315 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1316 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1318 if (!sock_flag(sk, SOCK_DEAD)) {
1319 pr_err("Attempt to release alive packet socket: %p\n", sk);
1323 sk_refcnt_debug_dec(sk);
1326 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1331 rxhash = skb_get_hash(skb);
1332 for (i = 0; i < ROLLOVER_HLEN; i++)
1333 if (po->rollover->history[i] == rxhash)
1336 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1337 return count > (ROLLOVER_HLEN >> 1);
1340 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1341 struct sk_buff *skb,
1344 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1347 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1348 struct sk_buff *skb,
1351 unsigned int val = atomic_inc_return(&f->rr_cur);
1356 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1357 struct sk_buff *skb,
1360 return smp_processor_id() % num;
1363 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1364 struct sk_buff *skb,
1367 return prandom_u32_max(num);
1370 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1371 struct sk_buff *skb,
1372 unsigned int idx, bool try_self,
1375 struct packet_sock *po, *po_next, *po_skip = NULL;
1376 unsigned int i, j, room = ROOM_NONE;
1378 po = pkt_sk(f->arr[idx]);
1381 room = packet_rcv_has_room(po, skb);
1382 if (room == ROOM_NORMAL ||
1383 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1388 i = j = min_t(int, po->rollover->sock, num - 1);
1390 po_next = pkt_sk(f->arr[i]);
1391 if (po_next != po_skip && !po_next->pressure &&
1392 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1394 po->rollover->sock = i;
1395 atomic_long_inc(&po->rollover->num);
1396 if (room == ROOM_LOW)
1397 atomic_long_inc(&po->rollover->num_huge);
1405 atomic_long_inc(&po->rollover->num_failed);
1409 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1410 struct sk_buff *skb,
1413 return skb_get_queue_mapping(skb) % num;
1416 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1417 struct sk_buff *skb,
1420 struct bpf_prog *prog;
1421 unsigned int ret = 0;
1424 prog = rcu_dereference(f->bpf_prog);
1426 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1432 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1434 return f->flags & (flag >> 8);
1437 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1438 struct packet_type *pt, struct net_device *orig_dev)
1440 struct packet_fanout *f = pt->af_packet_priv;
1441 unsigned int num = READ_ONCE(f->num_members);
1442 struct net *net = read_pnet(&f->net);
1443 struct packet_sock *po;
1446 if (!net_eq(dev_net(dev), net) || !num) {
1451 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1452 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1457 case PACKET_FANOUT_HASH:
1459 idx = fanout_demux_hash(f, skb, num);
1461 case PACKET_FANOUT_LB:
1462 idx = fanout_demux_lb(f, skb, num);
1464 case PACKET_FANOUT_CPU:
1465 idx = fanout_demux_cpu(f, skb, num);
1467 case PACKET_FANOUT_RND:
1468 idx = fanout_demux_rnd(f, skb, num);
1470 case PACKET_FANOUT_QM:
1471 idx = fanout_demux_qm(f, skb, num);
1473 case PACKET_FANOUT_ROLLOVER:
1474 idx = fanout_demux_rollover(f, skb, 0, false, num);
1476 case PACKET_FANOUT_CBPF:
1477 case PACKET_FANOUT_EBPF:
1478 idx = fanout_demux_bpf(f, skb, num);
1482 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1483 idx = fanout_demux_rollover(f, skb, idx, true, num);
1485 po = pkt_sk(f->arr[idx]);
1486 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1489 DEFINE_MUTEX(fanout_mutex);
1490 EXPORT_SYMBOL_GPL(fanout_mutex);
1491 static LIST_HEAD(fanout_list);
1493 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1495 struct packet_fanout *f = po->fanout;
1497 spin_lock(&f->lock);
1498 f->arr[f->num_members] = sk;
1501 spin_unlock(&f->lock);
1504 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1506 struct packet_fanout *f = po->fanout;
1509 spin_lock(&f->lock);
1510 for (i = 0; i < f->num_members; i++) {
1511 if (f->arr[i] == sk)
1514 BUG_ON(i >= f->num_members);
1515 f->arr[i] = f->arr[f->num_members - 1];
1517 spin_unlock(&f->lock);
1520 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1522 if (sk->sk_family != PF_PACKET)
1525 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1528 static void fanout_init_data(struct packet_fanout *f)
1531 case PACKET_FANOUT_LB:
1532 atomic_set(&f->rr_cur, 0);
1534 case PACKET_FANOUT_CBPF:
1535 case PACKET_FANOUT_EBPF:
1536 RCU_INIT_POINTER(f->bpf_prog, NULL);
1541 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1543 struct bpf_prog *old;
1545 spin_lock(&f->lock);
1546 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1547 rcu_assign_pointer(f->bpf_prog, new);
1548 spin_unlock(&f->lock);
1552 bpf_prog_destroy(old);
1556 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1559 struct bpf_prog *new;
1560 struct sock_fprog fprog;
1563 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1565 if (len != sizeof(fprog))
1567 if (copy_from_user(&fprog, data, len))
1570 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1574 __fanout_set_data_bpf(po->fanout, new);
1578 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1581 struct bpf_prog *new;
1584 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1586 if (len != sizeof(fd))
1588 if (copy_from_user(&fd, data, len))
1591 new = bpf_prog_get(fd);
1593 return PTR_ERR(new);
1594 if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) {
1599 __fanout_set_data_bpf(po->fanout, new);
1603 static int fanout_set_data(struct packet_sock *po, char __user *data,
1606 switch (po->fanout->type) {
1607 case PACKET_FANOUT_CBPF:
1608 return fanout_set_data_cbpf(po, data, len);
1609 case PACKET_FANOUT_EBPF:
1610 return fanout_set_data_ebpf(po, data, len);
1616 static void fanout_release_data(struct packet_fanout *f)
1619 case PACKET_FANOUT_CBPF:
1620 case PACKET_FANOUT_EBPF:
1621 __fanout_set_data_bpf(f, NULL);
1625 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1627 struct packet_sock *po = pkt_sk(sk);
1628 struct packet_fanout *f, *match;
1629 u8 type = type_flags & 0xff;
1630 u8 flags = type_flags >> 8;
1634 case PACKET_FANOUT_ROLLOVER:
1635 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1637 case PACKET_FANOUT_HASH:
1638 case PACKET_FANOUT_LB:
1639 case PACKET_FANOUT_CPU:
1640 case PACKET_FANOUT_RND:
1641 case PACKET_FANOUT_QM:
1642 case PACKET_FANOUT_CBPF:
1643 case PACKET_FANOUT_EBPF:
1655 if (type == PACKET_FANOUT_ROLLOVER ||
1656 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1657 po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL);
1660 atomic_long_set(&po->rollover->num, 0);
1661 atomic_long_set(&po->rollover->num_huge, 0);
1662 atomic_long_set(&po->rollover->num_failed, 0);
1665 mutex_lock(&fanout_mutex);
1667 list_for_each_entry(f, &fanout_list, list) {
1669 read_pnet(&f->net) == sock_net(sk)) {
1675 if (match && match->flags != flags)
1679 match = kzalloc(sizeof(*match), GFP_KERNEL);
1682 write_pnet(&match->net, sock_net(sk));
1685 match->flags = flags;
1686 INIT_LIST_HEAD(&match->list);
1687 spin_lock_init(&match->lock);
1688 atomic_set(&match->sk_ref, 0);
1689 fanout_init_data(match);
1690 match->prot_hook.type = po->prot_hook.type;
1691 match->prot_hook.dev = po->prot_hook.dev;
1692 match->prot_hook.func = packet_rcv_fanout;
1693 match->prot_hook.af_packet_priv = match;
1694 match->prot_hook.id_match = match_fanout_group;
1695 dev_add_pack(&match->prot_hook);
1696 list_add(&match->list, &fanout_list);
1699 if (match->type == type &&
1700 match->prot_hook.type == po->prot_hook.type &&
1701 match->prot_hook.dev == po->prot_hook.dev) {
1703 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1704 __dev_remove_pack(&po->prot_hook);
1706 atomic_inc(&match->sk_ref);
1707 __fanout_link(sk, po);
1712 mutex_unlock(&fanout_mutex);
1714 kfree(po->rollover);
1715 po->rollover = NULL;
1720 static void fanout_release(struct sock *sk)
1722 struct packet_sock *po = pkt_sk(sk);
1723 struct packet_fanout *f;
1729 mutex_lock(&fanout_mutex);
1732 if (atomic_dec_and_test(&f->sk_ref)) {
1734 dev_remove_pack(&f->prot_hook);
1735 fanout_release_data(f);
1738 mutex_unlock(&fanout_mutex);
1741 kfree_rcu(po->rollover, rcu);
1744 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1745 struct sk_buff *skb)
1747 /* Earlier code assumed this would be a VLAN pkt, double-check
1748 * this now that we have the actual packet in hand. We can only
1749 * do this check on Ethernet devices.
1751 if (unlikely(dev->type != ARPHRD_ETHER))
1754 skb_reset_mac_header(skb);
1755 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1758 static const struct proto_ops packet_ops;
1760 static const struct proto_ops packet_ops_spkt;
1762 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1763 struct packet_type *pt, struct net_device *orig_dev)
1766 struct sockaddr_pkt *spkt;
1769 * When we registered the protocol we saved the socket in the data
1770 * field for just this event.
1773 sk = pt->af_packet_priv;
1776 * Yank back the headers [hope the device set this
1777 * right or kerboom...]
1779 * Incoming packets have ll header pulled,
1782 * For outgoing ones skb->data == skb_mac_header(skb)
1783 * so that this procedure is noop.
1786 if (skb->pkt_type == PACKET_LOOPBACK)
1789 if (!net_eq(dev_net(dev), sock_net(sk)))
1792 skb = skb_share_check(skb, GFP_ATOMIC);
1796 /* drop any routing info */
1799 /* drop conntrack reference */
1802 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1804 skb_push(skb, skb->data - skb_mac_header(skb));
1807 * The SOCK_PACKET socket receives _all_ frames.
1810 spkt->spkt_family = dev->type;
1811 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1812 spkt->spkt_protocol = skb->protocol;
1815 * Charge the memory to the socket. This is done specifically
1816 * to prevent sockets using all the memory up.
1819 if (sock_queue_rcv_skb(sk, skb) == 0)
1830 * Output a raw packet to a device layer. This bypasses all the other
1831 * protocol layers and you must therefore supply it with a complete frame
1834 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1837 struct sock *sk = sock->sk;
1838 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1839 struct sk_buff *skb = NULL;
1840 struct net_device *dev;
1846 * Get and verify the address.
1850 if (msg->msg_namelen < sizeof(struct sockaddr))
1852 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1853 proto = saddr->spkt_protocol;
1855 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1858 * Find the device first to size check it
1861 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1864 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1870 if (!(dev->flags & IFF_UP))
1874 * You may not queue a frame bigger than the mtu. This is the lowest level
1875 * raw protocol and you must do your own fragmentation at this level.
1878 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1879 if (!netif_supports_nofcs(dev)) {
1880 err = -EPROTONOSUPPORT;
1883 extra_len = 4; /* We're doing our own CRC */
1887 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1891 size_t reserved = LL_RESERVED_SPACE(dev);
1892 int tlen = dev->needed_tailroom;
1893 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1896 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1899 /* FIXME: Save some space for broken drivers that write a hard
1900 * header at transmission time by themselves. PPP is the notable
1901 * one here. This should really be fixed at the driver level.
1903 skb_reserve(skb, reserved);
1904 skb_reset_network_header(skb);
1906 /* Try to align data part correctly */
1911 skb_reset_network_header(skb);
1913 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1919 if (!dev_validate_header(dev, skb->data, len)) {
1923 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1924 !packet_extra_vlan_len_allowed(dev, skb)) {
1929 skb->protocol = proto;
1931 skb->priority = sk->sk_priority;
1932 skb->mark = sk->sk_mark;
1934 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1936 if (unlikely(extra_len == 4))
1939 skb_probe_transport_header(skb, 0);
1941 dev_queue_xmit(skb);
1952 static unsigned int run_filter(struct sk_buff *skb,
1953 const struct sock *sk,
1956 struct sk_filter *filter;
1959 filter = rcu_dereference(sk->sk_filter);
1961 res = bpf_prog_run_clear_cb(filter->prog, skb);
1968 * This function makes lazy skb cloning in hope that most of packets
1969 * are discarded by BPF.
1971 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1972 * and skb->cb are mangled. It works because (and until) packets
1973 * falling here are owned by current CPU. Output packets are cloned
1974 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1975 * sequencially, so that if we return skb to original state on exit,
1976 * we will not harm anyone.
1979 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1980 struct packet_type *pt, struct net_device *orig_dev)
1983 struct sockaddr_ll *sll;
1984 struct packet_sock *po;
1985 u8 *skb_head = skb->data;
1986 int skb_len = skb->len;
1987 unsigned int snaplen, res;
1989 if (skb->pkt_type == PACKET_LOOPBACK)
1992 sk = pt->af_packet_priv;
1995 if (!net_eq(dev_net(dev), sock_net(sk)))
2000 if (dev->header_ops) {
2001 /* The device has an explicit notion of ll header,
2002 * exported to higher levels.
2004 * Otherwise, the device hides details of its frame
2005 * structure, so that corresponding packet head is
2006 * never delivered to user.
2008 if (sk->sk_type != SOCK_DGRAM)
2009 skb_push(skb, skb->data - skb_mac_header(skb));
2010 else if (skb->pkt_type == PACKET_OUTGOING) {
2011 /* Special case: outgoing packets have ll header at head */
2012 skb_pull(skb, skb_network_offset(skb));
2018 res = run_filter(skb, sk, snaplen);
2020 goto drop_n_restore;
2024 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2027 if (skb_shared(skb)) {
2028 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2032 if (skb_head != skb->data) {
2033 skb->data = skb_head;
2040 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2042 sll = &PACKET_SKB_CB(skb)->sa.ll;
2043 sll->sll_hatype = dev->type;
2044 sll->sll_pkttype = skb->pkt_type;
2045 if (unlikely(po->origdev))
2046 sll->sll_ifindex = orig_dev->ifindex;
2048 sll->sll_ifindex = dev->ifindex;
2050 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2052 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2053 * Use their space for storing the original skb length.
2055 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2057 if (pskb_trim(skb, snaplen))
2060 skb_set_owner_r(skb, sk);
2064 /* drop conntrack reference */
2067 spin_lock(&sk->sk_receive_queue.lock);
2068 po->stats.stats1.tp_packets++;
2069 sock_skb_set_dropcount(sk, skb);
2070 __skb_queue_tail(&sk->sk_receive_queue, skb);
2071 spin_unlock(&sk->sk_receive_queue.lock);
2072 sk->sk_data_ready(sk);
2076 spin_lock(&sk->sk_receive_queue.lock);
2077 po->stats.stats1.tp_drops++;
2078 atomic_inc(&sk->sk_drops);
2079 spin_unlock(&sk->sk_receive_queue.lock);
2082 if (skb_head != skb->data && skb_shared(skb)) {
2083 skb->data = skb_head;
2091 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2092 struct packet_type *pt, struct net_device *orig_dev)
2095 struct packet_sock *po;
2096 struct sockaddr_ll *sll;
2097 union tpacket_uhdr h;
2098 u8 *skb_head = skb->data;
2099 int skb_len = skb->len;
2100 unsigned int snaplen, res;
2101 unsigned long status = TP_STATUS_USER;
2102 unsigned short macoff, netoff, hdrlen;
2103 struct sk_buff *copy_skb = NULL;
2107 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2108 * We may add members to them until current aligned size without forcing
2109 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2111 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2112 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2114 if (skb->pkt_type == PACKET_LOOPBACK)
2117 sk = pt->af_packet_priv;
2120 if (!net_eq(dev_net(dev), sock_net(sk)))
2123 if (dev->header_ops) {
2124 if (sk->sk_type != SOCK_DGRAM)
2125 skb_push(skb, skb->data - skb_mac_header(skb));
2126 else if (skb->pkt_type == PACKET_OUTGOING) {
2127 /* Special case: outgoing packets have ll header at head */
2128 skb_pull(skb, skb_network_offset(skb));
2134 res = run_filter(skb, sk, snaplen);
2136 goto drop_n_restore;
2138 if (skb->ip_summed == CHECKSUM_PARTIAL)
2139 status |= TP_STATUS_CSUMNOTREADY;
2140 else if (skb->pkt_type != PACKET_OUTGOING &&
2141 (skb->ip_summed == CHECKSUM_COMPLETE ||
2142 skb_csum_unnecessary(skb)))
2143 status |= TP_STATUS_CSUM_VALID;
2148 if (sk->sk_type == SOCK_DGRAM) {
2149 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2152 unsigned int maclen = skb_network_offset(skb);
2153 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2154 (maclen < 16 ? 16 : maclen)) +
2156 macoff = netoff - maclen;
2158 if (po->tp_version <= TPACKET_V2) {
2159 if (macoff + snaplen > po->rx_ring.frame_size) {
2160 if (po->copy_thresh &&
2161 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2162 if (skb_shared(skb)) {
2163 copy_skb = skb_clone(skb, GFP_ATOMIC);
2165 copy_skb = skb_get(skb);
2166 skb_head = skb->data;
2169 skb_set_owner_r(copy_skb, sk);
2171 snaplen = po->rx_ring.frame_size - macoff;
2172 if ((int)snaplen < 0)
2175 } else if (unlikely(macoff + snaplen >
2176 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2179 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2180 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2181 snaplen, nval, macoff);
2183 if (unlikely((int)snaplen < 0)) {
2185 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2188 spin_lock(&sk->sk_receive_queue.lock);
2189 h.raw = packet_current_rx_frame(po, skb,
2190 TP_STATUS_KERNEL, (macoff+snaplen));
2193 if (po->tp_version <= TPACKET_V2) {
2194 packet_increment_rx_head(po, &po->rx_ring);
2196 * LOSING will be reported till you read the stats,
2197 * because it's COR - Clear On Read.
2198 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2201 if (po->stats.stats1.tp_drops)
2202 status |= TP_STATUS_LOSING;
2204 po->stats.stats1.tp_packets++;
2206 status |= TP_STATUS_COPY;
2207 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2209 spin_unlock(&sk->sk_receive_queue.lock);
2211 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2213 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2214 getnstimeofday(&ts);
2216 status |= ts_status;
2218 switch (po->tp_version) {
2220 h.h1->tp_len = skb->len;
2221 h.h1->tp_snaplen = snaplen;
2222 h.h1->tp_mac = macoff;
2223 h.h1->tp_net = netoff;
2224 h.h1->tp_sec = ts.tv_sec;
2225 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2226 hdrlen = sizeof(*h.h1);
2229 h.h2->tp_len = skb->len;
2230 h.h2->tp_snaplen = snaplen;
2231 h.h2->tp_mac = macoff;
2232 h.h2->tp_net = netoff;
2233 h.h2->tp_sec = ts.tv_sec;
2234 h.h2->tp_nsec = ts.tv_nsec;
2235 if (skb_vlan_tag_present(skb)) {
2236 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2237 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2238 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2240 h.h2->tp_vlan_tci = 0;
2241 h.h2->tp_vlan_tpid = 0;
2243 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2244 hdrlen = sizeof(*h.h2);
2247 /* tp_nxt_offset,vlan are already populated above.
2248 * So DONT clear those fields here
2250 h.h3->tp_status |= status;
2251 h.h3->tp_len = skb->len;
2252 h.h3->tp_snaplen = snaplen;
2253 h.h3->tp_mac = macoff;
2254 h.h3->tp_net = netoff;
2255 h.h3->tp_sec = ts.tv_sec;
2256 h.h3->tp_nsec = ts.tv_nsec;
2257 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2258 hdrlen = sizeof(*h.h3);
2264 sll = h.raw + TPACKET_ALIGN(hdrlen);
2265 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2266 sll->sll_family = AF_PACKET;
2267 sll->sll_hatype = dev->type;
2268 sll->sll_protocol = skb->protocol;
2269 sll->sll_pkttype = skb->pkt_type;
2270 if (unlikely(po->origdev))
2271 sll->sll_ifindex = orig_dev->ifindex;
2273 sll->sll_ifindex = dev->ifindex;
2277 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2278 if (po->tp_version <= TPACKET_V2) {
2281 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2284 for (start = h.raw; start < end; start += PAGE_SIZE)
2285 flush_dcache_page(pgv_to_page(start));
2290 if (po->tp_version <= TPACKET_V2) {
2291 __packet_set_status(po, h.raw, status);
2292 sk->sk_data_ready(sk);
2294 prb_clear_blk_fill_status(&po->rx_ring);
2298 if (skb_head != skb->data && skb_shared(skb)) {
2299 skb->data = skb_head;
2307 po->stats.stats1.tp_drops++;
2308 spin_unlock(&sk->sk_receive_queue.lock);
2310 sk->sk_data_ready(sk);
2311 kfree_skb(copy_skb);
2312 goto drop_n_restore;
2315 static void tpacket_destruct_skb(struct sk_buff *skb)
2317 struct packet_sock *po = pkt_sk(skb->sk);
2319 if (likely(po->tx_ring.pg_vec)) {
2323 ph = skb_shinfo(skb)->destructor_arg;
2324 packet_dec_pending(&po->tx_ring);
2326 ts = __packet_set_timestamp(po, ph, skb);
2327 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2333 static void tpacket_set_protocol(const struct net_device *dev,
2334 struct sk_buff *skb)
2336 if (dev->type == ARPHRD_ETHER) {
2337 skb_reset_mac_header(skb);
2338 skb->protocol = eth_hdr(skb)->h_proto;
2342 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2343 void *frame, struct net_device *dev, int size_max,
2344 __be16 proto, unsigned char *addr, int hlen)
2346 union tpacket_uhdr ph;
2347 int to_write, offset, len, tp_len, nr_frags, len_max;
2348 struct socket *sock = po->sk.sk_socket;
2355 skb->protocol = proto;
2357 skb->priority = po->sk.sk_priority;
2358 skb->mark = po->sk.sk_mark;
2359 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2360 skb_shinfo(skb)->destructor_arg = ph.raw;
2362 switch (po->tp_version) {
2364 tp_len = ph.h2->tp_len;
2367 tp_len = ph.h1->tp_len;
2370 if (unlikely(tp_len > size_max)) {
2371 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2375 skb_reserve(skb, hlen);
2376 skb_reset_network_header(skb);
2378 if (unlikely(po->tp_tx_has_off)) {
2379 int off_min, off_max, off;
2380 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2381 off_max = po->tx_ring.frame_size - tp_len;
2382 if (sock->type == SOCK_DGRAM) {
2383 switch (po->tp_version) {
2385 off = ph.h2->tp_net;
2388 off = ph.h1->tp_net;
2392 switch (po->tp_version) {
2394 off = ph.h2->tp_mac;
2397 off = ph.h1->tp_mac;
2401 if (unlikely((off < off_min) || (off_max < off)))
2403 data = ph.raw + off;
2405 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2409 if (sock->type == SOCK_DGRAM) {
2410 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2412 if (unlikely(err < 0))
2414 } else if (dev->hard_header_len) {
2415 int hdrlen = min_t(int, dev->hard_header_len, tp_len);
2417 skb_push(skb, dev->hard_header_len);
2418 err = skb_store_bits(skb, 0, data, hdrlen);
2421 if (!dev_validate_header(dev, skb->data, hdrlen))
2424 tpacket_set_protocol(dev, skb);
2430 offset = offset_in_page(data);
2431 len_max = PAGE_SIZE - offset;
2432 len = ((to_write > len_max) ? len_max : to_write);
2434 skb->data_len = to_write;
2435 skb->len += to_write;
2436 skb->truesize += to_write;
2437 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2439 while (likely(to_write)) {
2440 nr_frags = skb_shinfo(skb)->nr_frags;
2442 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2443 pr_err("Packet exceed the number of skb frags(%lu)\n",
2448 page = pgv_to_page(data);
2450 flush_dcache_page(page);
2452 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2455 len_max = PAGE_SIZE;
2456 len = ((to_write > len_max) ? len_max : to_write);
2459 skb_probe_transport_header(skb, 0);
2464 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2466 struct sk_buff *skb;
2467 struct net_device *dev;
2469 int err, reserve = 0;
2471 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2472 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2473 int tp_len, size_max;
2474 unsigned char *addr;
2476 int status = TP_STATUS_AVAILABLE;
2479 mutex_lock(&po->pg_vec_lock);
2481 if (likely(saddr == NULL)) {
2482 dev = packet_cached_dev_get(po);
2487 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2489 if (msg->msg_namelen < (saddr->sll_halen
2490 + offsetof(struct sockaddr_ll,
2493 proto = saddr->sll_protocol;
2494 addr = saddr->sll_addr;
2495 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2499 if (unlikely(dev == NULL))
2502 if (unlikely(!(dev->flags & IFF_UP)))
2505 if (po->sk.sk_socket->type == SOCK_RAW)
2506 reserve = dev->hard_header_len;
2507 size_max = po->tx_ring.frame_size
2508 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2510 if (size_max > dev->mtu + reserve + VLAN_HLEN)
2511 size_max = dev->mtu + reserve + VLAN_HLEN;
2514 ph = packet_current_frame(po, &po->tx_ring,
2515 TP_STATUS_SEND_REQUEST);
2516 if (unlikely(ph == NULL)) {
2517 if (need_wait && need_resched())
2522 status = TP_STATUS_SEND_REQUEST;
2523 hlen = LL_RESERVED_SPACE(dev);
2524 tlen = dev->needed_tailroom;
2525 skb = sock_alloc_send_skb(&po->sk,
2526 hlen + tlen + sizeof(struct sockaddr_ll),
2529 if (unlikely(skb == NULL)) {
2530 /* we assume the socket was initially writeable ... */
2531 if (likely(len_sum > 0))
2535 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2537 if (likely(tp_len >= 0) &&
2538 tp_len > dev->mtu + reserve &&
2539 !packet_extra_vlan_len_allowed(dev, skb))
2542 if (unlikely(tp_len < 0)) {
2544 __packet_set_status(po, ph,
2545 TP_STATUS_AVAILABLE);
2546 packet_increment_head(&po->tx_ring);
2550 status = TP_STATUS_WRONG_FORMAT;
2556 packet_pick_tx_queue(dev, skb);
2558 skb->destructor = tpacket_destruct_skb;
2559 __packet_set_status(po, ph, TP_STATUS_SENDING);
2560 packet_inc_pending(&po->tx_ring);
2562 status = TP_STATUS_SEND_REQUEST;
2563 err = po->xmit(skb);
2564 if (unlikely(err > 0)) {
2565 err = net_xmit_errno(err);
2566 if (err && __packet_get_status(po, ph) ==
2567 TP_STATUS_AVAILABLE) {
2568 /* skb was destructed already */
2573 * skb was dropped but not destructed yet;
2574 * let's treat it like congestion or err < 0
2578 packet_increment_head(&po->tx_ring);
2580 } while (likely((ph != NULL) ||
2581 /* Note: packet_read_pending() might be slow if we have
2582 * to call it as it's per_cpu variable, but in fast-path
2583 * we already short-circuit the loop with the first
2584 * condition, and luckily don't have to go that path
2587 (need_wait && packet_read_pending(&po->tx_ring))));
2593 __packet_set_status(po, ph, status);
2598 mutex_unlock(&po->pg_vec_lock);
2602 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2603 size_t reserve, size_t len,
2604 size_t linear, int noblock,
2607 struct sk_buff *skb;
2609 /* Under a page? Don't bother with paged skb. */
2610 if (prepad + len < PAGE_SIZE || !linear)
2613 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2618 skb_reserve(skb, reserve);
2619 skb_put(skb, linear);
2620 skb->data_len = len - linear;
2621 skb->len += len - linear;
2626 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2628 struct sock *sk = sock->sk;
2629 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2630 struct sk_buff *skb;
2631 struct net_device *dev;
2633 unsigned char *addr;
2634 int err, reserve = 0;
2635 struct sockcm_cookie sockc;
2636 struct virtio_net_hdr vnet_hdr = { 0 };
2639 struct packet_sock *po = pkt_sk(sk);
2640 unsigned short gso_type = 0;
2641 int hlen, tlen, linear;
2646 * Get and verify the address.
2649 if (likely(saddr == NULL)) {
2650 dev = packet_cached_dev_get(po);
2655 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2657 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2659 proto = saddr->sll_protocol;
2660 addr = saddr->sll_addr;
2661 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2665 if (unlikely(dev == NULL))
2668 if (unlikely(!(dev->flags & IFF_UP)))
2671 sockc.mark = sk->sk_mark;
2672 if (msg->msg_controllen) {
2673 err = sock_cmsg_send(sk, msg, &sockc);
2678 if (sock->type == SOCK_RAW)
2679 reserve = dev->hard_header_len;
2680 if (po->has_vnet_hdr) {
2681 vnet_hdr_len = sizeof(vnet_hdr);
2684 if (len < vnet_hdr_len)
2687 len -= vnet_hdr_len;
2690 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter);
2691 if (n != vnet_hdr_len)
2694 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2695 (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2696 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 >
2697 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len)))
2698 vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(),
2699 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2700 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2);
2703 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len)
2706 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2707 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2708 case VIRTIO_NET_HDR_GSO_TCPV4:
2709 gso_type = SKB_GSO_TCPV4;
2711 case VIRTIO_NET_HDR_GSO_TCPV6:
2712 gso_type = SKB_GSO_TCPV6;
2714 case VIRTIO_NET_HDR_GSO_UDP:
2715 gso_type = SKB_GSO_UDP;
2721 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2722 gso_type |= SKB_GSO_TCP_ECN;
2724 if (vnet_hdr.gso_size == 0)
2730 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2731 if (!netif_supports_nofcs(dev)) {
2732 err = -EPROTONOSUPPORT;
2735 extra_len = 4; /* We're doing our own CRC */
2739 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2743 hlen = LL_RESERVED_SPACE(dev);
2744 tlen = dev->needed_tailroom;
2745 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2746 linear = max(linear, min_t(int, len, dev->hard_header_len));
2747 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2748 msg->msg_flags & MSG_DONTWAIT, &err);
2752 skb_set_network_header(skb, reserve);
2755 if (sock->type == SOCK_DGRAM) {
2756 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2757 if (unlikely(offset < 0))
2761 /* Returns -EFAULT on error */
2762 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2766 if (sock->type == SOCK_RAW &&
2767 !dev_validate_header(dev, skb->data, len)) {
2772 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2774 if (!gso_type && (len > dev->mtu + reserve + extra_len) &&
2775 !packet_extra_vlan_len_allowed(dev, skb)) {
2780 skb->protocol = proto;
2782 skb->priority = sk->sk_priority;
2783 skb->mark = sockc.mark;
2785 packet_pick_tx_queue(dev, skb);
2787 if (po->has_vnet_hdr) {
2788 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2789 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start);
2790 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset);
2791 if (!skb_partial_csum_set(skb, s, o)) {
2797 skb_shinfo(skb)->gso_size =
2798 __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size);
2799 skb_shinfo(skb)->gso_type = gso_type;
2801 /* Header must be checked, and gso_segs computed. */
2802 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2803 skb_shinfo(skb)->gso_segs = 0;
2805 len += vnet_hdr_len;
2808 skb_probe_transport_header(skb, reserve);
2810 if (unlikely(extra_len == 4))
2813 err = po->xmit(skb);
2814 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2830 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2832 struct sock *sk = sock->sk;
2833 struct packet_sock *po = pkt_sk(sk);
2835 if (po->tx_ring.pg_vec)
2836 return tpacket_snd(po, msg);
2838 return packet_snd(sock, msg, len);
2842 * Close a PACKET socket. This is fairly simple. We immediately go
2843 * to 'closed' state and remove our protocol entry in the device list.
2846 static int packet_release(struct socket *sock)
2848 struct sock *sk = sock->sk;
2849 struct packet_sock *po;
2851 union tpacket_req_u req_u;
2859 mutex_lock(&net->packet.sklist_lock);
2860 sk_del_node_init_rcu(sk);
2861 mutex_unlock(&net->packet.sklist_lock);
2864 sock_prot_inuse_add(net, sk->sk_prot, -1);
2867 spin_lock(&po->bind_lock);
2868 unregister_prot_hook(sk, false);
2869 packet_cached_dev_reset(po);
2871 if (po->prot_hook.dev) {
2872 dev_put(po->prot_hook.dev);
2873 po->prot_hook.dev = NULL;
2875 spin_unlock(&po->bind_lock);
2877 packet_flush_mclist(sk);
2879 if (po->rx_ring.pg_vec) {
2880 memset(&req_u, 0, sizeof(req_u));
2881 packet_set_ring(sk, &req_u, 1, 0);
2884 if (po->tx_ring.pg_vec) {
2885 memset(&req_u, 0, sizeof(req_u));
2886 packet_set_ring(sk, &req_u, 1, 1);
2893 * Now the socket is dead. No more input will appear.
2900 skb_queue_purge(&sk->sk_receive_queue);
2901 packet_free_pending(po);
2902 sk_refcnt_debug_release(sk);
2909 * Attach a packet hook.
2912 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2915 struct packet_sock *po = pkt_sk(sk);
2916 struct net_device *dev_curr;
2919 struct net_device *dev = NULL;
2921 bool unlisted = false;
2927 spin_lock(&po->bind_lock);
2931 dev = dev_get_by_name_rcu(sock_net(sk), name);
2936 } else if (ifindex) {
2937 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
2947 proto_curr = po->prot_hook.type;
2948 dev_curr = po->prot_hook.dev;
2950 need_rehook = proto_curr != proto || dev_curr != dev;
2955 __unregister_prot_hook(sk, true);
2957 dev_curr = po->prot_hook.dev;
2959 unlisted = !dev_get_by_index_rcu(sock_net(sk),
2964 po->prot_hook.type = proto;
2966 if (unlikely(unlisted)) {
2968 po->prot_hook.dev = NULL;
2970 packet_cached_dev_reset(po);
2972 po->prot_hook.dev = dev;
2973 po->ifindex = dev ? dev->ifindex : 0;
2974 packet_cached_dev_assign(po, dev);
2980 if (proto == 0 || !need_rehook)
2983 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
2984 register_prot_hook(sk);
2986 sk->sk_err = ENETDOWN;
2987 if (!sock_flag(sk, SOCK_DEAD))
2988 sk->sk_error_report(sk);
2993 spin_unlock(&po->bind_lock);
2999 * Bind a packet socket to a device
3002 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3005 struct sock *sk = sock->sk;
3012 if (addr_len != sizeof(struct sockaddr))
3014 strlcpy(name, uaddr->sa_data, sizeof(name));
3016 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3019 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3021 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3022 struct sock *sk = sock->sk;
3028 if (addr_len < sizeof(struct sockaddr_ll))
3030 if (sll->sll_family != AF_PACKET)
3033 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3034 sll->sll_protocol ? : pkt_sk(sk)->num);
3037 static struct proto packet_proto = {
3039 .owner = THIS_MODULE,
3040 .obj_size = sizeof(struct packet_sock),
3044 * Create a packet of type SOCK_PACKET.
3047 static int packet_create(struct net *net, struct socket *sock, int protocol,
3051 struct packet_sock *po;
3052 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3055 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3057 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3058 sock->type != SOCK_PACKET)
3059 return -ESOCKTNOSUPPORT;
3061 sock->state = SS_UNCONNECTED;
3064 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3068 sock->ops = &packet_ops;
3069 if (sock->type == SOCK_PACKET)
3070 sock->ops = &packet_ops_spkt;
3072 sock_init_data(sock, sk);
3075 sk->sk_family = PF_PACKET;
3077 po->xmit = dev_queue_xmit;
3079 err = packet_alloc_pending(po);
3083 packet_cached_dev_reset(po);
3085 sk->sk_destruct = packet_sock_destruct;
3086 sk_refcnt_debug_inc(sk);
3089 * Attach a protocol block
3092 spin_lock_init(&po->bind_lock);
3093 mutex_init(&po->pg_vec_lock);
3094 po->rollover = NULL;
3095 po->prot_hook.func = packet_rcv;
3097 if (sock->type == SOCK_PACKET)
3098 po->prot_hook.func = packet_rcv_spkt;
3100 po->prot_hook.af_packet_priv = sk;
3103 po->prot_hook.type = proto;
3104 register_prot_hook(sk);
3107 mutex_lock(&net->packet.sklist_lock);
3108 sk_add_node_rcu(sk, &net->packet.sklist);
3109 mutex_unlock(&net->packet.sklist_lock);
3112 sock_prot_inuse_add(net, &packet_proto, 1);
3123 * Pull a packet from our receive queue and hand it to the user.
3124 * If necessary we block.
3127 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3130 struct sock *sk = sock->sk;
3131 struct sk_buff *skb;
3133 int vnet_hdr_len = 0;
3134 unsigned int origlen = 0;
3137 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3141 /* What error should we return now? EUNATTACH? */
3142 if (pkt_sk(sk)->ifindex < 0)
3146 if (flags & MSG_ERRQUEUE) {
3147 err = sock_recv_errqueue(sk, msg, len,
3148 SOL_PACKET, PACKET_TX_TIMESTAMP);
3153 * Call the generic datagram receiver. This handles all sorts
3154 * of horrible races and re-entrancy so we can forget about it
3155 * in the protocol layers.
3157 * Now it will return ENETDOWN, if device have just gone down,
3158 * but then it will block.
3161 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3164 * An error occurred so return it. Because skb_recv_datagram()
3165 * handles the blocking we don't see and worry about blocking
3172 if (pkt_sk(sk)->pressure)
3173 packet_rcv_has_room(pkt_sk(sk), NULL);
3175 if (pkt_sk(sk)->has_vnet_hdr) {
3176 struct virtio_net_hdr vnet_hdr = { 0 };
3179 vnet_hdr_len = sizeof(vnet_hdr);
3180 if (len < vnet_hdr_len)
3183 len -= vnet_hdr_len;
3185 if (skb_is_gso(skb)) {
3186 struct skb_shared_info *sinfo = skb_shinfo(skb);
3188 /* This is a hint as to how much should be linear. */
3190 __cpu_to_virtio16(vio_le(), skb_headlen(skb));
3192 __cpu_to_virtio16(vio_le(), sinfo->gso_size);
3193 if (sinfo->gso_type & SKB_GSO_TCPV4)
3194 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
3195 else if (sinfo->gso_type & SKB_GSO_TCPV6)
3196 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
3197 else if (sinfo->gso_type & SKB_GSO_UDP)
3198 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
3199 else if (sinfo->gso_type & SKB_GSO_FCOE)
3203 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
3204 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
3206 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
3208 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3209 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
3210 vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(),
3211 skb_checksum_start_offset(skb));
3212 vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(),
3214 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3215 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
3216 } /* else everything is zero */
3218 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);
3223 /* You lose any data beyond the buffer you gave. If it worries
3224 * a user program they can ask the device for its MTU
3230 msg->msg_flags |= MSG_TRUNC;
3233 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3237 if (sock->type != SOCK_PACKET) {
3238 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3240 /* Original length was stored in sockaddr_ll fields */
3241 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3242 sll->sll_family = AF_PACKET;
3243 sll->sll_protocol = skb->protocol;
3246 sock_recv_ts_and_drops(msg, sk, skb);
3248 if (msg->msg_name) {
3249 /* If the address length field is there to be filled
3250 * in, we fill it in now.
3252 if (sock->type == SOCK_PACKET) {
3253 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3254 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3256 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3258 msg->msg_namelen = sll->sll_halen +
3259 offsetof(struct sockaddr_ll, sll_addr);
3261 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3265 if (pkt_sk(sk)->auxdata) {
3266 struct tpacket_auxdata aux;
3268 aux.tp_status = TP_STATUS_USER;
3269 if (skb->ip_summed == CHECKSUM_PARTIAL)
3270 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3271 else if (skb->pkt_type != PACKET_OUTGOING &&
3272 (skb->ip_summed == CHECKSUM_COMPLETE ||
3273 skb_csum_unnecessary(skb)))
3274 aux.tp_status |= TP_STATUS_CSUM_VALID;
3276 aux.tp_len = origlen;
3277 aux.tp_snaplen = skb->len;
3279 aux.tp_net = skb_network_offset(skb);
3280 if (skb_vlan_tag_present(skb)) {
3281 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3282 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3283 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3285 aux.tp_vlan_tci = 0;
3286 aux.tp_vlan_tpid = 0;
3288 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3292 * Free or return the buffer as appropriate. Again this
3293 * hides all the races and re-entrancy issues from us.
3295 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3298 skb_free_datagram(sk, skb);
3303 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3304 int *uaddr_len, int peer)
3306 struct net_device *dev;
3307 struct sock *sk = sock->sk;
3312 uaddr->sa_family = AF_PACKET;
3313 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3315 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3317 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3319 *uaddr_len = sizeof(*uaddr);
3324 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3325 int *uaddr_len, int peer)
3327 struct net_device *dev;
3328 struct sock *sk = sock->sk;
3329 struct packet_sock *po = pkt_sk(sk);
3330 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3335 sll->sll_family = AF_PACKET;
3336 sll->sll_ifindex = po->ifindex;
3337 sll->sll_protocol = po->num;
3338 sll->sll_pkttype = 0;
3340 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3342 sll->sll_hatype = dev->type;
3343 sll->sll_halen = dev->addr_len;
3344 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3346 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3350 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3355 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3359 case PACKET_MR_MULTICAST:
3360 if (i->alen != dev->addr_len)
3363 return dev_mc_add(dev, i->addr);
3365 return dev_mc_del(dev, i->addr);
3367 case PACKET_MR_PROMISC:
3368 return dev_set_promiscuity(dev, what);
3369 case PACKET_MR_ALLMULTI:
3370 return dev_set_allmulti(dev, what);
3371 case PACKET_MR_UNICAST:
3372 if (i->alen != dev->addr_len)
3375 return dev_uc_add(dev, i->addr);
3377 return dev_uc_del(dev, i->addr);
3385 static void packet_dev_mclist_delete(struct net_device *dev,
3386 struct packet_mclist **mlp)
3388 struct packet_mclist *ml;
3390 while ((ml = *mlp) != NULL) {
3391 if (ml->ifindex == dev->ifindex) {
3392 packet_dev_mc(dev, ml, -1);
3400 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3402 struct packet_sock *po = pkt_sk(sk);
3403 struct packet_mclist *ml, *i;
3404 struct net_device *dev;
3410 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3415 if (mreq->mr_alen > dev->addr_len)
3419 i = kmalloc(sizeof(*i), GFP_KERNEL);
3424 for (ml = po->mclist; ml; ml = ml->next) {
3425 if (ml->ifindex == mreq->mr_ifindex &&
3426 ml->type == mreq->mr_type &&
3427 ml->alen == mreq->mr_alen &&
3428 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3430 /* Free the new element ... */
3436 i->type = mreq->mr_type;
3437 i->ifindex = mreq->mr_ifindex;
3438 i->alen = mreq->mr_alen;
3439 memcpy(i->addr, mreq->mr_address, i->alen);
3440 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3442 i->next = po->mclist;
3444 err = packet_dev_mc(dev, i, 1);
3446 po->mclist = i->next;
3455 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3457 struct packet_mclist *ml, **mlp;
3461 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3462 if (ml->ifindex == mreq->mr_ifindex &&
3463 ml->type == mreq->mr_type &&
3464 ml->alen == mreq->mr_alen &&
3465 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3466 if (--ml->count == 0) {
3467 struct net_device *dev;
3469 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3471 packet_dev_mc(dev, ml, -1);
3481 static void packet_flush_mclist(struct sock *sk)
3483 struct packet_sock *po = pkt_sk(sk);
3484 struct packet_mclist *ml;
3490 while ((ml = po->mclist) != NULL) {
3491 struct net_device *dev;
3493 po->mclist = ml->next;
3494 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3496 packet_dev_mc(dev, ml, -1);
3503 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3505 struct sock *sk = sock->sk;
3506 struct packet_sock *po = pkt_sk(sk);
3509 if (level != SOL_PACKET)
3510 return -ENOPROTOOPT;
3513 case PACKET_ADD_MEMBERSHIP:
3514 case PACKET_DROP_MEMBERSHIP:
3516 struct packet_mreq_max mreq;
3518 memset(&mreq, 0, sizeof(mreq));
3519 if (len < sizeof(struct packet_mreq))
3521 if (len > sizeof(mreq))
3523 if (copy_from_user(&mreq, optval, len))
3525 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3527 if (optname == PACKET_ADD_MEMBERSHIP)
3528 ret = packet_mc_add(sk, &mreq);
3530 ret = packet_mc_drop(sk, &mreq);
3534 case PACKET_RX_RING:
3535 case PACKET_TX_RING:
3537 union tpacket_req_u req_u;
3540 switch (po->tp_version) {
3543 len = sizeof(req_u.req);
3547 len = sizeof(req_u.req3);
3552 if (pkt_sk(sk)->has_vnet_hdr)
3554 if (copy_from_user(&req_u.req, optval, len))
3556 return packet_set_ring(sk, &req_u, 0,
3557 optname == PACKET_TX_RING);
3559 case PACKET_COPY_THRESH:
3563 if (optlen != sizeof(val))
3565 if (copy_from_user(&val, optval, sizeof(val)))
3568 pkt_sk(sk)->copy_thresh = val;
3571 case PACKET_VERSION:
3575 if (optlen != sizeof(val))
3577 if (copy_from_user(&val, optval, sizeof(val)))
3588 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3591 po->tp_version = val;
3597 case PACKET_RESERVE:
3601 if (optlen != sizeof(val))
3603 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3605 if (copy_from_user(&val, optval, sizeof(val)))
3607 po->tp_reserve = val;
3614 if (optlen != sizeof(val))
3616 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3618 if (copy_from_user(&val, optval, sizeof(val)))
3620 po->tp_loss = !!val;
3623 case PACKET_AUXDATA:
3627 if (optlen < sizeof(val))
3629 if (copy_from_user(&val, optval, sizeof(val)))
3632 po->auxdata = !!val;
3635 case PACKET_ORIGDEV:
3639 if (optlen < sizeof(val))
3641 if (copy_from_user(&val, optval, sizeof(val)))
3644 po->origdev = !!val;
3647 case PACKET_VNET_HDR:
3651 if (sock->type != SOCK_RAW)
3653 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3655 if (optlen < sizeof(val))
3657 if (copy_from_user(&val, optval, sizeof(val)))
3660 po->has_vnet_hdr = !!val;
3663 case PACKET_TIMESTAMP:
3667 if (optlen != sizeof(val))
3669 if (copy_from_user(&val, optval, sizeof(val)))
3672 po->tp_tstamp = val;
3679 if (optlen != sizeof(val))
3681 if (copy_from_user(&val, optval, sizeof(val)))
3684 return fanout_add(sk, val & 0xffff, val >> 16);
3686 case PACKET_FANOUT_DATA:
3691 return fanout_set_data(po, optval, optlen);
3693 case PACKET_TX_HAS_OFF:
3697 if (optlen != sizeof(val))
3699 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3701 if (copy_from_user(&val, optval, sizeof(val)))
3703 po->tp_tx_has_off = !!val;
3706 case PACKET_QDISC_BYPASS:
3710 if (optlen != sizeof(val))
3712 if (copy_from_user(&val, optval, sizeof(val)))
3715 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3719 return -ENOPROTOOPT;
3723 static int packet_getsockopt(struct socket *sock, int level, int optname,
3724 char __user *optval, int __user *optlen)
3727 int val, lv = sizeof(val);
3728 struct sock *sk = sock->sk;
3729 struct packet_sock *po = pkt_sk(sk);
3731 union tpacket_stats_u st;
3732 struct tpacket_rollover_stats rstats;
3734 if (level != SOL_PACKET)
3735 return -ENOPROTOOPT;
3737 if (get_user(len, optlen))
3744 case PACKET_STATISTICS:
3745 spin_lock_bh(&sk->sk_receive_queue.lock);
3746 memcpy(&st, &po->stats, sizeof(st));
3747 memset(&po->stats, 0, sizeof(po->stats));
3748 spin_unlock_bh(&sk->sk_receive_queue.lock);
3750 if (po->tp_version == TPACKET_V3) {
3751 lv = sizeof(struct tpacket_stats_v3);
3752 st.stats3.tp_packets += st.stats3.tp_drops;
3755 lv = sizeof(struct tpacket_stats);
3756 st.stats1.tp_packets += st.stats1.tp_drops;
3761 case PACKET_AUXDATA:
3764 case PACKET_ORIGDEV:
3767 case PACKET_VNET_HDR:
3768 val = po->has_vnet_hdr;
3770 case PACKET_VERSION:
3771 val = po->tp_version;
3774 if (len > sizeof(int))
3776 if (copy_from_user(&val, optval, len))
3780 val = sizeof(struct tpacket_hdr);
3783 val = sizeof(struct tpacket2_hdr);
3786 val = sizeof(struct tpacket3_hdr);
3792 case PACKET_RESERVE:
3793 val = po->tp_reserve;
3798 case PACKET_TIMESTAMP:
3799 val = po->tp_tstamp;
3803 ((u32)po->fanout->id |
3804 ((u32)po->fanout->type << 16) |
3805 ((u32)po->fanout->flags << 24)) :
3808 case PACKET_ROLLOVER_STATS:
3811 rstats.tp_all = atomic_long_read(&po->rollover->num);
3812 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3813 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3815 lv = sizeof(rstats);
3817 case PACKET_TX_HAS_OFF:
3818 val = po->tp_tx_has_off;
3820 case PACKET_QDISC_BYPASS:
3821 val = packet_use_direct_xmit(po);
3824 return -ENOPROTOOPT;
3829 if (put_user(len, optlen))
3831 if (copy_to_user(optval, data, len))
3837 static int packet_notifier(struct notifier_block *this,
3838 unsigned long msg, void *ptr)
3841 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3842 struct net *net = dev_net(dev);
3845 sk_for_each_rcu(sk, &net->packet.sklist) {
3846 struct packet_sock *po = pkt_sk(sk);
3849 case NETDEV_UNREGISTER:
3851 packet_dev_mclist_delete(dev, &po->mclist);
3855 if (dev->ifindex == po->ifindex) {
3856 spin_lock(&po->bind_lock);
3858 __unregister_prot_hook(sk, false);
3859 sk->sk_err = ENETDOWN;
3860 if (!sock_flag(sk, SOCK_DEAD))
3861 sk->sk_error_report(sk);
3863 if (msg == NETDEV_UNREGISTER) {
3864 packet_cached_dev_reset(po);
3867 if (po->prot_hook.dev)
3868 dev_put(po->prot_hook.dev);
3869 po->prot_hook.dev = NULL;
3871 spin_unlock(&po->bind_lock);
3875 if (dev->ifindex == po->ifindex) {
3876 spin_lock(&po->bind_lock);
3878 register_prot_hook(sk);
3879 spin_unlock(&po->bind_lock);
3889 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3892 struct sock *sk = sock->sk;
3897 int amount = sk_wmem_alloc_get(sk);
3899 return put_user(amount, (int __user *)arg);
3903 struct sk_buff *skb;
3906 spin_lock_bh(&sk->sk_receive_queue.lock);
3907 skb = skb_peek(&sk->sk_receive_queue);
3910 spin_unlock_bh(&sk->sk_receive_queue.lock);
3911 return put_user(amount, (int __user *)arg);
3914 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3916 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3926 case SIOCGIFBRDADDR:
3927 case SIOCSIFBRDADDR:
3928 case SIOCGIFNETMASK:
3929 case SIOCSIFNETMASK:
3930 case SIOCGIFDSTADDR:
3931 case SIOCSIFDSTADDR:
3933 return inet_dgram_ops.ioctl(sock, cmd, arg);
3937 return -ENOIOCTLCMD;
3942 static unsigned int packet_poll(struct file *file, struct socket *sock,
3945 struct sock *sk = sock->sk;
3946 struct packet_sock *po = pkt_sk(sk);
3947 unsigned int mask = datagram_poll(file, sock, wait);
3949 spin_lock_bh(&sk->sk_receive_queue.lock);
3950 if (po->rx_ring.pg_vec) {
3951 if (!packet_previous_rx_frame(po, &po->rx_ring,
3953 mask |= POLLIN | POLLRDNORM;
3955 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
3957 spin_unlock_bh(&sk->sk_receive_queue.lock);
3958 spin_lock_bh(&sk->sk_write_queue.lock);
3959 if (po->tx_ring.pg_vec) {
3960 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3961 mask |= POLLOUT | POLLWRNORM;
3963 spin_unlock_bh(&sk->sk_write_queue.lock);
3968 /* Dirty? Well, I still did not learn better way to account
3972 static void packet_mm_open(struct vm_area_struct *vma)
3974 struct file *file = vma->vm_file;
3975 struct socket *sock = file->private_data;
3976 struct sock *sk = sock->sk;
3979 atomic_inc(&pkt_sk(sk)->mapped);
3982 static void packet_mm_close(struct vm_area_struct *vma)
3984 struct file *file = vma->vm_file;
3985 struct socket *sock = file->private_data;
3986 struct sock *sk = sock->sk;
3989 atomic_dec(&pkt_sk(sk)->mapped);
3992 static const struct vm_operations_struct packet_mmap_ops = {
3993 .open = packet_mm_open,
3994 .close = packet_mm_close,
3997 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4002 for (i = 0; i < len; i++) {
4003 if (likely(pg_vec[i].buffer)) {
4004 if (is_vmalloc_addr(pg_vec[i].buffer))
4005 vfree(pg_vec[i].buffer);
4007 free_pages((unsigned long)pg_vec[i].buffer,
4009 pg_vec[i].buffer = NULL;
4015 static char *alloc_one_pg_vec_page(unsigned long order)
4018 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4019 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4021 buffer = (char *) __get_free_pages(gfp_flags, order);
4025 /* __get_free_pages failed, fall back to vmalloc */
4026 buffer = vzalloc((1 << order) * PAGE_SIZE);
4030 /* vmalloc failed, lets dig into swap here */
4031 gfp_flags &= ~__GFP_NORETRY;
4032 buffer = (char *) __get_free_pages(gfp_flags, order);
4036 /* complete and utter failure */
4040 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4042 unsigned int block_nr = req->tp_block_nr;
4046 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4047 if (unlikely(!pg_vec))
4050 for (i = 0; i < block_nr; i++) {
4051 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4052 if (unlikely(!pg_vec[i].buffer))
4053 goto out_free_pgvec;
4060 free_pg_vec(pg_vec, order, block_nr);
4065 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4066 int closing, int tx_ring)
4068 struct pgv *pg_vec = NULL;
4069 struct packet_sock *po = pkt_sk(sk);
4070 int was_running, order = 0;
4071 struct packet_ring_buffer *rb;
4072 struct sk_buff_head *rb_queue;
4075 /* Added to avoid minimal code churn */
4076 struct tpacket_req *req = &req_u->req;
4079 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4080 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4081 WARN(1, "Tx-ring is not supported.\n");
4085 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4086 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4090 if (atomic_read(&po->mapped))
4092 if (packet_read_pending(rb))
4096 if (req->tp_block_nr) {
4097 /* Sanity tests and some calculations */
4099 if (unlikely(rb->pg_vec))
4102 switch (po->tp_version) {
4104 po->tp_hdrlen = TPACKET_HDRLEN;
4107 po->tp_hdrlen = TPACKET2_HDRLEN;
4110 po->tp_hdrlen = TPACKET3_HDRLEN;
4115 if (unlikely((int)req->tp_block_size <= 0))
4117 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4119 if (po->tp_version >= TPACKET_V3 &&
4120 (int)(req->tp_block_size -
4121 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4123 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4126 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4129 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4130 if (unlikely(rb->frames_per_block == 0))
4132 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4137 order = get_order(req->tp_block_size);
4138 pg_vec = alloc_pg_vec(req, order);
4139 if (unlikely(!pg_vec))
4141 switch (po->tp_version) {
4143 /* Transmit path is not supported. We checked
4144 * it above but just being paranoid
4147 init_prb_bdqc(po, rb, pg_vec, req_u);
4156 if (unlikely(req->tp_frame_nr))
4161 /* Detach socket from network */
4162 spin_lock(&po->bind_lock);
4163 was_running = po->running;
4167 __unregister_prot_hook(sk, false);
4169 spin_unlock(&po->bind_lock);
4174 mutex_lock(&po->pg_vec_lock);
4175 if (closing || atomic_read(&po->mapped) == 0) {
4177 spin_lock_bh(&rb_queue->lock);
4178 swap(rb->pg_vec, pg_vec);
4179 rb->frame_max = (req->tp_frame_nr - 1);
4181 rb->frame_size = req->tp_frame_size;
4182 spin_unlock_bh(&rb_queue->lock);
4184 swap(rb->pg_vec_order, order);
4185 swap(rb->pg_vec_len, req->tp_block_nr);
4187 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4188 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4189 tpacket_rcv : packet_rcv;
4190 skb_queue_purge(rb_queue);
4191 if (atomic_read(&po->mapped))
4192 pr_err("packet_mmap: vma is busy: %d\n",
4193 atomic_read(&po->mapped));
4195 mutex_unlock(&po->pg_vec_lock);
4197 spin_lock(&po->bind_lock);
4200 register_prot_hook(sk);
4202 spin_unlock(&po->bind_lock);
4203 if (closing && (po->tp_version > TPACKET_V2)) {
4204 /* Because we don't support block-based V3 on tx-ring */
4206 prb_shutdown_retire_blk_timer(po, rb_queue);
4210 free_pg_vec(pg_vec, order, req->tp_block_nr);
4216 static int packet_mmap(struct file *file, struct socket *sock,
4217 struct vm_area_struct *vma)
4219 struct sock *sk = sock->sk;
4220 struct packet_sock *po = pkt_sk(sk);
4221 unsigned long size, expected_size;
4222 struct packet_ring_buffer *rb;
4223 unsigned long start;
4230 mutex_lock(&po->pg_vec_lock);
4233 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4235 expected_size += rb->pg_vec_len
4241 if (expected_size == 0)
4244 size = vma->vm_end - vma->vm_start;
4245 if (size != expected_size)
4248 start = vma->vm_start;
4249 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4250 if (rb->pg_vec == NULL)
4253 for (i = 0; i < rb->pg_vec_len; i++) {
4255 void *kaddr = rb->pg_vec[i].buffer;
4258 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4259 page = pgv_to_page(kaddr);
4260 err = vm_insert_page(vma, start, page);
4269 atomic_inc(&po->mapped);
4270 vma->vm_ops = &packet_mmap_ops;
4274 mutex_unlock(&po->pg_vec_lock);
4278 static const struct proto_ops packet_ops_spkt = {
4279 .family = PF_PACKET,
4280 .owner = THIS_MODULE,
4281 .release = packet_release,
4282 .bind = packet_bind_spkt,
4283 .connect = sock_no_connect,
4284 .socketpair = sock_no_socketpair,
4285 .accept = sock_no_accept,
4286 .getname = packet_getname_spkt,
4287 .poll = datagram_poll,
4288 .ioctl = packet_ioctl,
4289 .listen = sock_no_listen,
4290 .shutdown = sock_no_shutdown,
4291 .setsockopt = sock_no_setsockopt,
4292 .getsockopt = sock_no_getsockopt,
4293 .sendmsg = packet_sendmsg_spkt,
4294 .recvmsg = packet_recvmsg,
4295 .mmap = sock_no_mmap,
4296 .sendpage = sock_no_sendpage,
4299 static const struct proto_ops packet_ops = {
4300 .family = PF_PACKET,
4301 .owner = THIS_MODULE,
4302 .release = packet_release,
4303 .bind = packet_bind,
4304 .connect = sock_no_connect,
4305 .socketpair = sock_no_socketpair,
4306 .accept = sock_no_accept,
4307 .getname = packet_getname,
4308 .poll = packet_poll,
4309 .ioctl = packet_ioctl,
4310 .listen = sock_no_listen,
4311 .shutdown = sock_no_shutdown,
4312 .setsockopt = packet_setsockopt,
4313 .getsockopt = packet_getsockopt,
4314 .sendmsg = packet_sendmsg,
4315 .recvmsg = packet_recvmsg,
4316 .mmap = packet_mmap,
4317 .sendpage = sock_no_sendpage,
4320 static const struct net_proto_family packet_family_ops = {
4321 .family = PF_PACKET,
4322 .create = packet_create,
4323 .owner = THIS_MODULE,
4326 static struct notifier_block packet_netdev_notifier = {
4327 .notifier_call = packet_notifier,
4330 #ifdef CONFIG_PROC_FS
4332 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4335 struct net *net = seq_file_net(seq);
4338 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4341 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4343 struct net *net = seq_file_net(seq);
4344 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4347 static void packet_seq_stop(struct seq_file *seq, void *v)
4353 static int packet_seq_show(struct seq_file *seq, void *v)
4355 if (v == SEQ_START_TOKEN)
4356 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4358 struct sock *s = sk_entry(v);
4359 const struct packet_sock *po = pkt_sk(s);
4362 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4364 atomic_read(&s->sk_refcnt),
4369 atomic_read(&s->sk_rmem_alloc),
4370 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4377 static const struct seq_operations packet_seq_ops = {
4378 .start = packet_seq_start,
4379 .next = packet_seq_next,
4380 .stop = packet_seq_stop,
4381 .show = packet_seq_show,
4384 static int packet_seq_open(struct inode *inode, struct file *file)
4386 return seq_open_net(inode, file, &packet_seq_ops,
4387 sizeof(struct seq_net_private));
4390 static const struct file_operations packet_seq_fops = {
4391 .owner = THIS_MODULE,
4392 .open = packet_seq_open,
4394 .llseek = seq_lseek,
4395 .release = seq_release_net,
4400 static int __net_init packet_net_init(struct net *net)
4402 mutex_init(&net->packet.sklist_lock);
4403 INIT_HLIST_HEAD(&net->packet.sklist);
4405 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4411 static void __net_exit packet_net_exit(struct net *net)
4413 remove_proc_entry("packet", net->proc_net);
4416 static struct pernet_operations packet_net_ops = {
4417 .init = packet_net_init,
4418 .exit = packet_net_exit,
4422 static void __exit packet_exit(void)
4424 unregister_netdevice_notifier(&packet_netdev_notifier);
4425 unregister_pernet_subsys(&packet_net_ops);
4426 sock_unregister(PF_PACKET);
4427 proto_unregister(&packet_proto);
4430 static int __init packet_init(void)
4432 int rc = proto_register(&packet_proto, 0);
4437 sock_register(&packet_family_ops);
4438 register_pernet_subsys(&packet_net_ops);
4439 register_netdevice_notifier(&packet_netdev_notifier);
4444 module_init(packet_init);
4445 module_exit(packet_exit);
4446 MODULE_LICENSE("GPL");
4447 MODULE_ALIAS_NETPROTO(PF_PACKET);