2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * PACKET - implements raw packet sockets.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
55 #include <linux/types.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
79 #include <asm/cacheflush.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/percpu.h>
93 #include <net/inet_common.h>
95 #include <linux/bpf.h>
101 - if device has no dev->hard_header routine, it adds and removes ll header
102 inside itself. In this case ll header is invisible outside of device,
103 but higher levels still should reserve dev->hard_header_len.
104 Some devices are enough clever to reallocate skb, when header
105 will not fit to reserved space (tunnel), another ones are silly
107 - packet socket receives packets with pulled ll header,
108 so that SOCK_RAW should push it back.
113 Incoming, dev->hard_header!=NULL
114 mac_header -> ll header
117 Outgoing, dev->hard_header!=NULL
118 mac_header -> ll header
121 Incoming, dev->hard_header==NULL
122 mac_header -> UNKNOWN position. It is very likely, that it points to ll
123 header. PPP makes it, that is wrong, because introduce
124 assymetry between rx and tx paths.
127 Outgoing, dev->hard_header==NULL
128 mac_header -> data. ll header is still not built!
132 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
138 dev->hard_header != NULL
139 mac_header -> ll header
142 dev->hard_header == NULL (ll header is added by device, we cannot control it)
146 We should set nh.raw on output to correct posistion,
147 packet classifier depends on it.
150 /* Private packet socket structures. */
152 /* identical to struct packet_mreq except it has
153 * a longer address field.
155 struct packet_mreq_max {
157 unsigned short mr_type;
158 unsigned short mr_alen;
159 unsigned char mr_address[MAX_ADDR_LEN];
163 struct tpacket_hdr *h1;
164 struct tpacket2_hdr *h2;
165 struct tpacket3_hdr *h3;
169 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
170 int closing, int tx_ring);
172 #define V3_ALIGNMENT (8)
174 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
176 #define BLK_PLUS_PRIV(sz_of_priv) \
177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
179 #define PGV_FROM_VMALLOC 1
181 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
182 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
183 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
184 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
185 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
186 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
187 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
190 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
192 struct packet_type *pt, struct net_device *orig_dev);
194 static void *packet_previous_frame(struct packet_sock *po,
195 struct packet_ring_buffer *rb,
197 static void packet_increment_head(struct packet_ring_buffer *buff);
198 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
199 struct tpacket_block_desc *);
200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
201 struct packet_sock *);
202 static void prb_retire_current_block(struct tpacket_kbdq_core *,
203 struct packet_sock *, unsigned int status);
204 static int prb_queue_frozen(struct tpacket_kbdq_core *);
205 static void prb_open_block(struct tpacket_kbdq_core *,
206 struct tpacket_block_desc *);
207 static void prb_retire_rx_blk_timer_expired(unsigned long);
208 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
209 static void prb_init_blk_timer(struct packet_sock *,
210 struct tpacket_kbdq_core *,
211 void (*func) (unsigned long));
212 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
213 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
214 struct tpacket3_hdr *);
215 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
216 struct tpacket3_hdr *);
217 static void packet_flush_mclist(struct sock *sk);
219 struct packet_skb_cb {
221 struct sockaddr_pkt pkt;
223 /* Trick: alias skb original length with
224 * ll.sll_family and ll.protocol in order
227 unsigned int origlen;
228 struct sockaddr_ll ll;
233 #define vio_le() virtio_legacy_is_little_endian()
235 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
237 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
238 #define GET_PBLOCK_DESC(x, bid) \
239 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
240 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
241 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
242 #define GET_NEXT_PRB_BLK_NUM(x) \
243 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
244 ((x)->kactive_blk_num+1) : 0)
246 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
247 static void __fanout_link(struct sock *sk, struct packet_sock *po);
249 static int packet_direct_xmit(struct sk_buff *skb)
251 struct net_device *dev = skb->dev;
252 netdev_features_t features;
253 struct netdev_queue *txq;
254 int ret = NETDEV_TX_BUSY;
256 if (unlikely(!netif_running(dev) ||
257 !netif_carrier_ok(dev)))
260 features = netif_skb_features(skb);
261 if (skb_needs_linearize(skb, features) &&
262 __skb_linearize(skb))
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(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 (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1920 !packet_extra_vlan_len_allowed(dev, skb)) {
1925 skb->protocol = proto;
1927 skb->priority = sk->sk_priority;
1928 skb->mark = sk->sk_mark;
1930 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1932 if (unlikely(extra_len == 4))
1935 skb_probe_transport_header(skb, 0);
1937 dev_queue_xmit(skb);
1948 static unsigned int run_filter(struct sk_buff *skb,
1949 const struct sock *sk,
1952 struct sk_filter *filter;
1955 filter = rcu_dereference(sk->sk_filter);
1957 res = bpf_prog_run_clear_cb(filter->prog, skb);
1963 static int __packet_rcv_vnet(const struct sk_buff *skb,
1964 struct virtio_net_hdr *vnet_hdr)
1966 *vnet_hdr = (const struct virtio_net_hdr) { 0 };
1968 if (skb_is_gso(skb)) {
1969 struct skb_shared_info *sinfo = skb_shinfo(skb);
1971 /* This is a hint as to how much should be linear. */
1973 __cpu_to_virtio16(vio_le(), skb_headlen(skb));
1974 vnet_hdr->gso_size =
1975 __cpu_to_virtio16(vio_le(), sinfo->gso_size);
1977 if (sinfo->gso_type & SKB_GSO_TCPV4)
1978 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1979 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1980 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1981 else if (sinfo->gso_type & SKB_GSO_UDP)
1982 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
1983 else if (sinfo->gso_type & SKB_GSO_FCOE)
1988 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1989 vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1991 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
1993 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1994 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1995 vnet_hdr->csum_start = __cpu_to_virtio16(vio_le(),
1996 skb_checksum_start_offset(skb));
1997 vnet_hdr->csum_offset = __cpu_to_virtio16(vio_le(),
1999 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2000 vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
2001 } /* else everything is zero */
2006 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2009 struct virtio_net_hdr vnet_hdr;
2011 if (*len < sizeof(vnet_hdr))
2013 *len -= sizeof(vnet_hdr);
2015 if (__packet_rcv_vnet(skb, &vnet_hdr))
2018 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2022 * This function makes lazy skb cloning in hope that most of packets
2023 * are discarded by BPF.
2025 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2026 * and skb->cb are mangled. It works because (and until) packets
2027 * falling here are owned by current CPU. Output packets are cloned
2028 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2029 * sequencially, so that if we return skb to original state on exit,
2030 * we will not harm anyone.
2033 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2034 struct packet_type *pt, struct net_device *orig_dev)
2037 struct sockaddr_ll *sll;
2038 struct packet_sock *po;
2039 u8 *skb_head = skb->data;
2040 int skb_len = skb->len;
2041 unsigned int snaplen, res;
2043 if (skb->pkt_type == PACKET_LOOPBACK)
2046 sk = pt->af_packet_priv;
2049 if (!net_eq(dev_net(dev), sock_net(sk)))
2054 if (dev->header_ops) {
2055 /* The device has an explicit notion of ll header,
2056 * exported to higher levels.
2058 * Otherwise, the device hides details of its frame
2059 * structure, so that corresponding packet head is
2060 * never delivered to user.
2062 if (sk->sk_type != SOCK_DGRAM)
2063 skb_push(skb, skb->data - skb_mac_header(skb));
2064 else if (skb->pkt_type == PACKET_OUTGOING) {
2065 /* Special case: outgoing packets have ll header at head */
2066 skb_pull(skb, skb_network_offset(skb));
2072 res = run_filter(skb, sk, snaplen);
2074 goto drop_n_restore;
2078 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2081 if (skb_shared(skb)) {
2082 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2086 if (skb_head != skb->data) {
2087 skb->data = skb_head;
2094 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2096 sll = &PACKET_SKB_CB(skb)->sa.ll;
2097 sll->sll_hatype = dev->type;
2098 sll->sll_pkttype = skb->pkt_type;
2099 if (unlikely(po->origdev))
2100 sll->sll_ifindex = orig_dev->ifindex;
2102 sll->sll_ifindex = dev->ifindex;
2104 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2106 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2107 * Use their space for storing the original skb length.
2109 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2111 if (pskb_trim(skb, snaplen))
2114 skb_set_owner_r(skb, sk);
2118 /* drop conntrack reference */
2121 spin_lock(&sk->sk_receive_queue.lock);
2122 po->stats.stats1.tp_packets++;
2123 sock_skb_set_dropcount(sk, skb);
2124 __skb_queue_tail(&sk->sk_receive_queue, skb);
2125 spin_unlock(&sk->sk_receive_queue.lock);
2126 sk->sk_data_ready(sk);
2130 spin_lock(&sk->sk_receive_queue.lock);
2131 po->stats.stats1.tp_drops++;
2132 atomic_inc(&sk->sk_drops);
2133 spin_unlock(&sk->sk_receive_queue.lock);
2136 if (skb_head != skb->data && skb_shared(skb)) {
2137 skb->data = skb_head;
2145 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2146 struct packet_type *pt, struct net_device *orig_dev)
2149 struct packet_sock *po;
2150 struct sockaddr_ll *sll;
2151 union tpacket_uhdr h;
2152 u8 *skb_head = skb->data;
2153 int skb_len = skb->len;
2154 unsigned int snaplen, res;
2155 unsigned long status = TP_STATUS_USER;
2156 unsigned short macoff, netoff, hdrlen;
2157 struct sk_buff *copy_skb = NULL;
2161 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2162 * We may add members to them until current aligned size without forcing
2163 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2165 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2166 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2168 if (skb->pkt_type == PACKET_LOOPBACK)
2171 sk = pt->af_packet_priv;
2174 if (!net_eq(dev_net(dev), sock_net(sk)))
2177 if (dev->header_ops) {
2178 if (sk->sk_type != SOCK_DGRAM)
2179 skb_push(skb, skb->data - skb_mac_header(skb));
2180 else if (skb->pkt_type == PACKET_OUTGOING) {
2181 /* Special case: outgoing packets have ll header at head */
2182 skb_pull(skb, skb_network_offset(skb));
2188 res = run_filter(skb, sk, snaplen);
2190 goto drop_n_restore;
2192 if (skb->ip_summed == CHECKSUM_PARTIAL)
2193 status |= TP_STATUS_CSUMNOTREADY;
2194 else if (skb->pkt_type != PACKET_OUTGOING &&
2195 (skb->ip_summed == CHECKSUM_COMPLETE ||
2196 skb_csum_unnecessary(skb)))
2197 status |= TP_STATUS_CSUM_VALID;
2202 if (sk->sk_type == SOCK_DGRAM) {
2203 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2206 unsigned int maclen = skb_network_offset(skb);
2207 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2208 (maclen < 16 ? 16 : maclen)) +
2210 macoff = netoff - maclen;
2212 if (po->tp_version <= TPACKET_V2) {
2213 if (macoff + snaplen > po->rx_ring.frame_size) {
2214 if (po->copy_thresh &&
2215 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2216 if (skb_shared(skb)) {
2217 copy_skb = skb_clone(skb, GFP_ATOMIC);
2219 copy_skb = skb_get(skb);
2220 skb_head = skb->data;
2223 skb_set_owner_r(copy_skb, sk);
2225 snaplen = po->rx_ring.frame_size - macoff;
2226 if ((int)snaplen < 0)
2229 } else if (unlikely(macoff + snaplen >
2230 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2233 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2234 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2235 snaplen, nval, macoff);
2237 if (unlikely((int)snaplen < 0)) {
2239 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2242 spin_lock(&sk->sk_receive_queue.lock);
2243 h.raw = packet_current_rx_frame(po, skb,
2244 TP_STATUS_KERNEL, (macoff+snaplen));
2247 if (po->tp_version <= TPACKET_V2) {
2248 packet_increment_rx_head(po, &po->rx_ring);
2250 * LOSING will be reported till you read the stats,
2251 * because it's COR - Clear On Read.
2252 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2255 if (po->stats.stats1.tp_drops)
2256 status |= TP_STATUS_LOSING;
2258 po->stats.stats1.tp_packets++;
2260 status |= TP_STATUS_COPY;
2261 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2263 spin_unlock(&sk->sk_receive_queue.lock);
2265 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2267 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2268 getnstimeofday(&ts);
2270 status |= ts_status;
2272 switch (po->tp_version) {
2274 h.h1->tp_len = skb->len;
2275 h.h1->tp_snaplen = snaplen;
2276 h.h1->tp_mac = macoff;
2277 h.h1->tp_net = netoff;
2278 h.h1->tp_sec = ts.tv_sec;
2279 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2280 hdrlen = sizeof(*h.h1);
2283 h.h2->tp_len = skb->len;
2284 h.h2->tp_snaplen = snaplen;
2285 h.h2->tp_mac = macoff;
2286 h.h2->tp_net = netoff;
2287 h.h2->tp_sec = ts.tv_sec;
2288 h.h2->tp_nsec = ts.tv_nsec;
2289 if (skb_vlan_tag_present(skb)) {
2290 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2291 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2292 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2294 h.h2->tp_vlan_tci = 0;
2295 h.h2->tp_vlan_tpid = 0;
2297 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2298 hdrlen = sizeof(*h.h2);
2301 /* tp_nxt_offset,vlan are already populated above.
2302 * So DONT clear those fields here
2304 h.h3->tp_status |= status;
2305 h.h3->tp_len = skb->len;
2306 h.h3->tp_snaplen = snaplen;
2307 h.h3->tp_mac = macoff;
2308 h.h3->tp_net = netoff;
2309 h.h3->tp_sec = ts.tv_sec;
2310 h.h3->tp_nsec = ts.tv_nsec;
2311 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2312 hdrlen = sizeof(*h.h3);
2318 sll = h.raw + TPACKET_ALIGN(hdrlen);
2319 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2320 sll->sll_family = AF_PACKET;
2321 sll->sll_hatype = dev->type;
2322 sll->sll_protocol = skb->protocol;
2323 sll->sll_pkttype = skb->pkt_type;
2324 if (unlikely(po->origdev))
2325 sll->sll_ifindex = orig_dev->ifindex;
2327 sll->sll_ifindex = dev->ifindex;
2331 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2332 if (po->tp_version <= TPACKET_V2) {
2335 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2338 for (start = h.raw; start < end; start += PAGE_SIZE)
2339 flush_dcache_page(pgv_to_page(start));
2344 if (po->tp_version <= TPACKET_V2) {
2345 __packet_set_status(po, h.raw, status);
2346 sk->sk_data_ready(sk);
2348 prb_clear_blk_fill_status(&po->rx_ring);
2352 if (skb_head != skb->data && skb_shared(skb)) {
2353 skb->data = skb_head;
2361 po->stats.stats1.tp_drops++;
2362 spin_unlock(&sk->sk_receive_queue.lock);
2364 sk->sk_data_ready(sk);
2365 kfree_skb(copy_skb);
2366 goto drop_n_restore;
2369 static void tpacket_destruct_skb(struct sk_buff *skb)
2371 struct packet_sock *po = pkt_sk(skb->sk);
2373 if (likely(po->tx_ring.pg_vec)) {
2377 ph = skb_shinfo(skb)->destructor_arg;
2378 packet_dec_pending(&po->tx_ring);
2380 ts = __packet_set_timestamp(po, ph, skb);
2381 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2387 static bool ll_header_truncated(const struct net_device *dev, int len)
2389 /* net device doesn't like empty head */
2390 if (unlikely(len < dev->hard_header_len)) {
2391 net_warn_ratelimited("%s: packet size is too short (%d < %d)\n",
2392 current->comm, len, dev->hard_header_len);
2399 static void tpacket_set_protocol(const struct net_device *dev,
2400 struct sk_buff *skb)
2402 if (dev->type == ARPHRD_ETHER) {
2403 skb_reset_mac_header(skb);
2404 skb->protocol = eth_hdr(skb)->h_proto;
2408 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2410 unsigned short gso_type = 0;
2412 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2413 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2414 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2415 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2416 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2417 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2418 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2420 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2423 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2424 switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2425 case VIRTIO_NET_HDR_GSO_TCPV4:
2426 gso_type = SKB_GSO_TCPV4;
2428 case VIRTIO_NET_HDR_GSO_TCPV6:
2429 gso_type = SKB_GSO_TCPV6;
2431 case VIRTIO_NET_HDR_GSO_UDP:
2432 gso_type = SKB_GSO_UDP;
2438 if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
2439 gso_type |= SKB_GSO_TCP_ECN;
2441 if (vnet_hdr->gso_size == 0)
2445 vnet_hdr->gso_type = gso_type; /* changes type, temporary storage */
2449 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2450 struct virtio_net_hdr *vnet_hdr)
2454 if (*len < sizeof(*vnet_hdr))
2456 *len -= sizeof(*vnet_hdr);
2458 n = copy_from_iter(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter);
2459 if (n != sizeof(*vnet_hdr))
2462 return __packet_snd_vnet_parse(vnet_hdr, *len);
2465 static int packet_snd_vnet_gso(struct sk_buff *skb,
2466 struct virtio_net_hdr *vnet_hdr)
2468 if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2469 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start);
2470 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset);
2472 if (!skb_partial_csum_set(skb, s, o))
2476 skb_shinfo(skb)->gso_size =
2477 __virtio16_to_cpu(vio_le(), vnet_hdr->gso_size);
2478 skb_shinfo(skb)->gso_type = vnet_hdr->gso_type;
2480 /* Header must be checked, and gso_segs computed. */
2481 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2482 skb_shinfo(skb)->gso_segs = 0;
2486 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2487 void *frame, struct net_device *dev, int size_max,
2488 __be16 proto, unsigned char *addr, int hlen)
2490 union tpacket_uhdr ph;
2491 int to_write, offset, len, tp_len, nr_frags, len_max;
2492 struct socket *sock = po->sk.sk_socket;
2499 skb->protocol = proto;
2501 skb->priority = po->sk.sk_priority;
2502 skb->mark = po->sk.sk_mark;
2503 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2504 skb_shinfo(skb)->destructor_arg = ph.raw;
2506 switch (po->tp_version) {
2508 tp_len = ph.h2->tp_len;
2511 tp_len = ph.h1->tp_len;
2514 if (unlikely(tp_len > size_max)) {
2515 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2519 skb_reserve(skb, hlen);
2520 skb_reset_network_header(skb);
2522 if (unlikely(po->tp_tx_has_off)) {
2523 int off_min, off_max, off;
2524 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2525 off_max = po->tx_ring.frame_size - tp_len;
2526 if (sock->type == SOCK_DGRAM) {
2527 switch (po->tp_version) {
2529 off = ph.h2->tp_net;
2532 off = ph.h1->tp_net;
2536 switch (po->tp_version) {
2538 off = ph.h2->tp_mac;
2541 off = ph.h1->tp_mac;
2545 if (unlikely((off < off_min) || (off_max < off)))
2547 data = ph.raw + off;
2549 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2553 if (sock->type == SOCK_DGRAM) {
2554 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2556 if (unlikely(err < 0))
2558 } else if (dev->hard_header_len) {
2559 if (ll_header_truncated(dev, tp_len))
2562 skb_push(skb, dev->hard_header_len);
2563 err = skb_store_bits(skb, 0, data,
2564 dev->hard_header_len);
2568 tpacket_set_protocol(dev, skb);
2570 data += dev->hard_header_len;
2571 to_write -= dev->hard_header_len;
2574 offset = offset_in_page(data);
2575 len_max = PAGE_SIZE - offset;
2576 len = ((to_write > len_max) ? len_max : to_write);
2578 skb->data_len = to_write;
2579 skb->len += to_write;
2580 skb->truesize += to_write;
2581 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2583 while (likely(to_write)) {
2584 nr_frags = skb_shinfo(skb)->nr_frags;
2586 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2587 pr_err("Packet exceed the number of skb frags(%lu)\n",
2592 page = pgv_to_page(data);
2594 flush_dcache_page(page);
2596 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2599 len_max = PAGE_SIZE;
2600 len = ((to_write > len_max) ? len_max : to_write);
2603 skb_probe_transport_header(skb, 0);
2608 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2610 struct sk_buff *skb;
2611 struct net_device *dev;
2613 int err, reserve = 0;
2615 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2616 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2617 int tp_len, size_max;
2618 unsigned char *addr;
2620 int status = TP_STATUS_AVAILABLE;
2623 mutex_lock(&po->pg_vec_lock);
2625 if (likely(saddr == NULL)) {
2626 dev = packet_cached_dev_get(po);
2631 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2633 if (msg->msg_namelen < (saddr->sll_halen
2634 + offsetof(struct sockaddr_ll,
2637 proto = saddr->sll_protocol;
2638 addr = saddr->sll_addr;
2639 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2643 if (unlikely(dev == NULL))
2646 if (unlikely(!(dev->flags & IFF_UP)))
2649 if (po->sk.sk_socket->type == SOCK_RAW)
2650 reserve = dev->hard_header_len;
2651 size_max = po->tx_ring.frame_size
2652 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2654 if (size_max > dev->mtu + reserve + VLAN_HLEN)
2655 size_max = dev->mtu + reserve + VLAN_HLEN;
2658 ph = packet_current_frame(po, &po->tx_ring,
2659 TP_STATUS_SEND_REQUEST);
2660 if (unlikely(ph == NULL)) {
2661 if (need_wait && need_resched())
2666 status = TP_STATUS_SEND_REQUEST;
2667 hlen = LL_RESERVED_SPACE(dev);
2668 tlen = dev->needed_tailroom;
2669 skb = sock_alloc_send_skb(&po->sk,
2670 hlen + tlen + sizeof(struct sockaddr_ll),
2673 if (unlikely(skb == NULL)) {
2674 /* we assume the socket was initially writeable ... */
2675 if (likely(len_sum > 0))
2679 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2681 if (likely(tp_len >= 0) &&
2682 tp_len > dev->mtu + reserve &&
2683 !packet_extra_vlan_len_allowed(dev, skb))
2686 if (unlikely(tp_len < 0)) {
2688 __packet_set_status(po, ph,
2689 TP_STATUS_AVAILABLE);
2690 packet_increment_head(&po->tx_ring);
2694 status = TP_STATUS_WRONG_FORMAT;
2700 packet_pick_tx_queue(dev, skb);
2702 skb->destructor = tpacket_destruct_skb;
2703 __packet_set_status(po, ph, TP_STATUS_SENDING);
2704 packet_inc_pending(&po->tx_ring);
2706 status = TP_STATUS_SEND_REQUEST;
2707 err = po->xmit(skb);
2708 if (unlikely(err > 0)) {
2709 err = net_xmit_errno(err);
2710 if (err && __packet_get_status(po, ph) ==
2711 TP_STATUS_AVAILABLE) {
2712 /* skb was destructed already */
2717 * skb was dropped but not destructed yet;
2718 * let's treat it like congestion or err < 0
2722 packet_increment_head(&po->tx_ring);
2724 } while (likely((ph != NULL) ||
2725 /* Note: packet_read_pending() might be slow if we have
2726 * to call it as it's per_cpu variable, but in fast-path
2727 * we already short-circuit the loop with the first
2728 * condition, and luckily don't have to go that path
2731 (need_wait && packet_read_pending(&po->tx_ring))));
2737 __packet_set_status(po, ph, status);
2742 mutex_unlock(&po->pg_vec_lock);
2746 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2747 size_t reserve, size_t len,
2748 size_t linear, int noblock,
2751 struct sk_buff *skb;
2753 /* Under a page? Don't bother with paged skb. */
2754 if (prepad + len < PAGE_SIZE || !linear)
2757 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2762 skb_reserve(skb, reserve);
2763 skb_put(skb, linear);
2764 skb->data_len = len - linear;
2765 skb->len += len - linear;
2770 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2772 struct sock *sk = sock->sk;
2773 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2774 struct sk_buff *skb;
2775 struct net_device *dev;
2777 unsigned char *addr;
2778 int err, reserve = 0;
2779 struct sockcm_cookie sockc;
2780 struct virtio_net_hdr vnet_hdr = { 0 };
2782 struct packet_sock *po = pkt_sk(sk);
2787 * Get and verify the address.
2790 if (likely(saddr == NULL)) {
2791 dev = packet_cached_dev_get(po);
2796 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2798 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2800 proto = saddr->sll_protocol;
2801 addr = saddr->sll_addr;
2802 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2806 if (unlikely(dev == NULL))
2809 if (unlikely(!(dev->flags & IFF_UP)))
2812 sockc.mark = sk->sk_mark;
2813 if (msg->msg_controllen) {
2814 err = sock_cmsg_send(sk, msg, &sockc);
2819 if (sock->type == SOCK_RAW)
2820 reserve = dev->hard_header_len;
2821 if (po->has_vnet_hdr) {
2822 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2827 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2828 if (!netif_supports_nofcs(dev)) {
2829 err = -EPROTONOSUPPORT;
2832 extra_len = 4; /* We're doing our own CRC */
2836 if (!vnet_hdr.gso_type &&
2837 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2841 hlen = LL_RESERVED_SPACE(dev);
2842 tlen = dev->needed_tailroom;
2843 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
2844 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len),
2845 msg->msg_flags & MSG_DONTWAIT, &err);
2849 skb_set_network_header(skb, reserve);
2852 if (sock->type == SOCK_DGRAM) {
2853 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2854 if (unlikely(offset < 0))
2857 if (ll_header_truncated(dev, len))
2861 /* Returns -EFAULT on error */
2862 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2866 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2868 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2869 !packet_extra_vlan_len_allowed(dev, skb)) {
2874 skb->protocol = proto;
2876 skb->priority = sk->sk_priority;
2877 skb->mark = sockc.mark;
2879 packet_pick_tx_queue(dev, skb);
2881 if (po->has_vnet_hdr) {
2882 err = packet_snd_vnet_gso(skb, &vnet_hdr);
2885 len += sizeof(vnet_hdr);
2888 skb_probe_transport_header(skb, reserve);
2890 if (unlikely(extra_len == 4))
2893 err = po->xmit(skb);
2894 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2910 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2912 struct sock *sk = sock->sk;
2913 struct packet_sock *po = pkt_sk(sk);
2915 if (po->tx_ring.pg_vec)
2916 return tpacket_snd(po, msg);
2918 return packet_snd(sock, msg, len);
2922 * Close a PACKET socket. This is fairly simple. We immediately go
2923 * to 'closed' state and remove our protocol entry in the device list.
2926 static int packet_release(struct socket *sock)
2928 struct sock *sk = sock->sk;
2929 struct packet_sock *po;
2931 union tpacket_req_u req_u;
2939 mutex_lock(&net->packet.sklist_lock);
2940 sk_del_node_init_rcu(sk);
2941 mutex_unlock(&net->packet.sklist_lock);
2944 sock_prot_inuse_add(net, sk->sk_prot, -1);
2947 spin_lock(&po->bind_lock);
2948 unregister_prot_hook(sk, false);
2949 packet_cached_dev_reset(po);
2951 if (po->prot_hook.dev) {
2952 dev_put(po->prot_hook.dev);
2953 po->prot_hook.dev = NULL;
2955 spin_unlock(&po->bind_lock);
2957 packet_flush_mclist(sk);
2959 if (po->rx_ring.pg_vec) {
2960 memset(&req_u, 0, sizeof(req_u));
2961 packet_set_ring(sk, &req_u, 1, 0);
2964 if (po->tx_ring.pg_vec) {
2965 memset(&req_u, 0, sizeof(req_u));
2966 packet_set_ring(sk, &req_u, 1, 1);
2973 * Now the socket is dead. No more input will appear.
2980 skb_queue_purge(&sk->sk_receive_queue);
2981 packet_free_pending(po);
2982 sk_refcnt_debug_release(sk);
2989 * Attach a packet hook.
2992 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2995 struct packet_sock *po = pkt_sk(sk);
2996 struct net_device *dev_curr;
2999 struct net_device *dev = NULL;
3001 bool unlisted = false;
3007 spin_lock(&po->bind_lock);
3011 dev = dev_get_by_name_rcu(sock_net(sk), name);
3016 } else if (ifindex) {
3017 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3027 proto_curr = po->prot_hook.type;
3028 dev_curr = po->prot_hook.dev;
3030 need_rehook = proto_curr != proto || dev_curr != dev;
3035 __unregister_prot_hook(sk, true);
3037 dev_curr = po->prot_hook.dev;
3039 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3044 po->prot_hook.type = proto;
3046 if (unlikely(unlisted)) {
3048 po->prot_hook.dev = NULL;
3050 packet_cached_dev_reset(po);
3052 po->prot_hook.dev = dev;
3053 po->ifindex = dev ? dev->ifindex : 0;
3054 packet_cached_dev_assign(po, dev);
3060 if (proto == 0 || !need_rehook)
3063 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3064 register_prot_hook(sk);
3066 sk->sk_err = ENETDOWN;
3067 if (!sock_flag(sk, SOCK_DEAD))
3068 sk->sk_error_report(sk);
3073 spin_unlock(&po->bind_lock);
3079 * Bind a packet socket to a device
3082 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3085 struct sock *sk = sock->sk;
3092 if (addr_len != sizeof(struct sockaddr))
3094 strlcpy(name, uaddr->sa_data, sizeof(name));
3096 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3099 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3101 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3102 struct sock *sk = sock->sk;
3108 if (addr_len < sizeof(struct sockaddr_ll))
3110 if (sll->sll_family != AF_PACKET)
3113 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3114 sll->sll_protocol ? : pkt_sk(sk)->num);
3117 static struct proto packet_proto = {
3119 .owner = THIS_MODULE,
3120 .obj_size = sizeof(struct packet_sock),
3124 * Create a packet of type SOCK_PACKET.
3127 static int packet_create(struct net *net, struct socket *sock, int protocol,
3131 struct packet_sock *po;
3132 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3135 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3137 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3138 sock->type != SOCK_PACKET)
3139 return -ESOCKTNOSUPPORT;
3141 sock->state = SS_UNCONNECTED;
3144 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3148 sock->ops = &packet_ops;
3149 if (sock->type == SOCK_PACKET)
3150 sock->ops = &packet_ops_spkt;
3152 sock_init_data(sock, sk);
3155 sk->sk_family = PF_PACKET;
3157 po->xmit = dev_queue_xmit;
3159 err = packet_alloc_pending(po);
3163 packet_cached_dev_reset(po);
3165 sk->sk_destruct = packet_sock_destruct;
3166 sk_refcnt_debug_inc(sk);
3169 * Attach a protocol block
3172 spin_lock_init(&po->bind_lock);
3173 mutex_init(&po->pg_vec_lock);
3174 po->rollover = NULL;
3175 po->prot_hook.func = packet_rcv;
3177 if (sock->type == SOCK_PACKET)
3178 po->prot_hook.func = packet_rcv_spkt;
3180 po->prot_hook.af_packet_priv = sk;
3183 po->prot_hook.type = proto;
3184 register_prot_hook(sk);
3187 mutex_lock(&net->packet.sklist_lock);
3188 sk_add_node_rcu(sk, &net->packet.sklist);
3189 mutex_unlock(&net->packet.sklist_lock);
3192 sock_prot_inuse_add(net, &packet_proto, 1);
3203 * Pull a packet from our receive queue and hand it to the user.
3204 * If necessary we block.
3207 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3210 struct sock *sk = sock->sk;
3211 struct sk_buff *skb;
3213 int vnet_hdr_len = 0;
3214 unsigned int origlen = 0;
3217 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3221 /* What error should we return now? EUNATTACH? */
3222 if (pkt_sk(sk)->ifindex < 0)
3226 if (flags & MSG_ERRQUEUE) {
3227 err = sock_recv_errqueue(sk, msg, len,
3228 SOL_PACKET, PACKET_TX_TIMESTAMP);
3233 * Call the generic datagram receiver. This handles all sorts
3234 * of horrible races and re-entrancy so we can forget about it
3235 * in the protocol layers.
3237 * Now it will return ENETDOWN, if device have just gone down,
3238 * but then it will block.
3241 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3244 * An error occurred so return it. Because skb_recv_datagram()
3245 * handles the blocking we don't see and worry about blocking
3252 if (pkt_sk(sk)->pressure)
3253 packet_rcv_has_room(pkt_sk(sk), NULL);
3255 if (pkt_sk(sk)->has_vnet_hdr) {
3256 err = packet_rcv_vnet(msg, skb, &len);
3259 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3262 /* You lose any data beyond the buffer you gave. If it worries
3263 * a user program they can ask the device for its MTU
3269 msg->msg_flags |= MSG_TRUNC;
3272 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3276 if (sock->type != SOCK_PACKET) {
3277 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3279 /* Original length was stored in sockaddr_ll fields */
3280 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3281 sll->sll_family = AF_PACKET;
3282 sll->sll_protocol = skb->protocol;
3285 sock_recv_ts_and_drops(msg, sk, skb);
3287 if (msg->msg_name) {
3288 /* If the address length field is there to be filled
3289 * in, we fill it in now.
3291 if (sock->type == SOCK_PACKET) {
3292 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3293 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3295 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3297 msg->msg_namelen = sll->sll_halen +
3298 offsetof(struct sockaddr_ll, sll_addr);
3300 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3304 if (pkt_sk(sk)->auxdata) {
3305 struct tpacket_auxdata aux;
3307 aux.tp_status = TP_STATUS_USER;
3308 if (skb->ip_summed == CHECKSUM_PARTIAL)
3309 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3310 else if (skb->pkt_type != PACKET_OUTGOING &&
3311 (skb->ip_summed == CHECKSUM_COMPLETE ||
3312 skb_csum_unnecessary(skb)))
3313 aux.tp_status |= TP_STATUS_CSUM_VALID;
3315 aux.tp_len = origlen;
3316 aux.tp_snaplen = skb->len;
3318 aux.tp_net = skb_network_offset(skb);
3319 if (skb_vlan_tag_present(skb)) {
3320 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3321 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3322 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3324 aux.tp_vlan_tci = 0;
3325 aux.tp_vlan_tpid = 0;
3327 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3331 * Free or return the buffer as appropriate. Again this
3332 * hides all the races and re-entrancy issues from us.
3334 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3337 skb_free_datagram(sk, skb);
3342 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3343 int *uaddr_len, int peer)
3345 struct net_device *dev;
3346 struct sock *sk = sock->sk;
3351 uaddr->sa_family = AF_PACKET;
3352 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3354 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3356 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3358 *uaddr_len = sizeof(*uaddr);
3363 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3364 int *uaddr_len, int peer)
3366 struct net_device *dev;
3367 struct sock *sk = sock->sk;
3368 struct packet_sock *po = pkt_sk(sk);
3369 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3374 sll->sll_family = AF_PACKET;
3375 sll->sll_ifindex = po->ifindex;
3376 sll->sll_protocol = po->num;
3377 sll->sll_pkttype = 0;
3379 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3381 sll->sll_hatype = dev->type;
3382 sll->sll_halen = dev->addr_len;
3383 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3385 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3389 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3394 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3398 case PACKET_MR_MULTICAST:
3399 if (i->alen != dev->addr_len)
3402 return dev_mc_add(dev, i->addr);
3404 return dev_mc_del(dev, i->addr);
3406 case PACKET_MR_PROMISC:
3407 return dev_set_promiscuity(dev, what);
3408 case PACKET_MR_ALLMULTI:
3409 return dev_set_allmulti(dev, what);
3410 case PACKET_MR_UNICAST:
3411 if (i->alen != dev->addr_len)
3414 return dev_uc_add(dev, i->addr);
3416 return dev_uc_del(dev, i->addr);
3424 static void packet_dev_mclist_delete(struct net_device *dev,
3425 struct packet_mclist **mlp)
3427 struct packet_mclist *ml;
3429 while ((ml = *mlp) != NULL) {
3430 if (ml->ifindex == dev->ifindex) {
3431 packet_dev_mc(dev, ml, -1);
3439 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3441 struct packet_sock *po = pkt_sk(sk);
3442 struct packet_mclist *ml, *i;
3443 struct net_device *dev;
3449 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3454 if (mreq->mr_alen > dev->addr_len)
3458 i = kmalloc(sizeof(*i), GFP_KERNEL);
3463 for (ml = po->mclist; ml; ml = ml->next) {
3464 if (ml->ifindex == mreq->mr_ifindex &&
3465 ml->type == mreq->mr_type &&
3466 ml->alen == mreq->mr_alen &&
3467 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3469 /* Free the new element ... */
3475 i->type = mreq->mr_type;
3476 i->ifindex = mreq->mr_ifindex;
3477 i->alen = mreq->mr_alen;
3478 memcpy(i->addr, mreq->mr_address, i->alen);
3480 i->next = po->mclist;
3482 err = packet_dev_mc(dev, i, 1);
3484 po->mclist = i->next;
3493 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3495 struct packet_mclist *ml, **mlp;
3499 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3500 if (ml->ifindex == mreq->mr_ifindex &&
3501 ml->type == mreq->mr_type &&
3502 ml->alen == mreq->mr_alen &&
3503 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3504 if (--ml->count == 0) {
3505 struct net_device *dev;
3507 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3509 packet_dev_mc(dev, ml, -1);
3519 static void packet_flush_mclist(struct sock *sk)
3521 struct packet_sock *po = pkt_sk(sk);
3522 struct packet_mclist *ml;
3528 while ((ml = po->mclist) != NULL) {
3529 struct net_device *dev;
3531 po->mclist = ml->next;
3532 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3534 packet_dev_mc(dev, ml, -1);
3541 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3543 struct sock *sk = sock->sk;
3544 struct packet_sock *po = pkt_sk(sk);
3547 if (level != SOL_PACKET)
3548 return -ENOPROTOOPT;
3551 case PACKET_ADD_MEMBERSHIP:
3552 case PACKET_DROP_MEMBERSHIP:
3554 struct packet_mreq_max mreq;
3556 memset(&mreq, 0, sizeof(mreq));
3557 if (len < sizeof(struct packet_mreq))
3559 if (len > sizeof(mreq))
3561 if (copy_from_user(&mreq, optval, len))
3563 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3565 if (optname == PACKET_ADD_MEMBERSHIP)
3566 ret = packet_mc_add(sk, &mreq);
3568 ret = packet_mc_drop(sk, &mreq);
3572 case PACKET_RX_RING:
3573 case PACKET_TX_RING:
3575 union tpacket_req_u req_u;
3578 switch (po->tp_version) {
3581 len = sizeof(req_u.req);
3585 len = sizeof(req_u.req3);
3590 if (pkt_sk(sk)->has_vnet_hdr)
3592 if (copy_from_user(&req_u.req, optval, len))
3594 return packet_set_ring(sk, &req_u, 0,
3595 optname == PACKET_TX_RING);
3597 case PACKET_COPY_THRESH:
3601 if (optlen != sizeof(val))
3603 if (copy_from_user(&val, optval, sizeof(val)))
3606 pkt_sk(sk)->copy_thresh = val;
3609 case PACKET_VERSION:
3613 if (optlen != sizeof(val))
3615 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3617 if (copy_from_user(&val, optval, sizeof(val)))
3623 po->tp_version = val;
3629 case PACKET_RESERVE:
3633 if (optlen != sizeof(val))
3635 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3637 if (copy_from_user(&val, optval, sizeof(val)))
3639 po->tp_reserve = val;
3646 if (optlen != sizeof(val))
3648 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3650 if (copy_from_user(&val, optval, sizeof(val)))
3652 po->tp_loss = !!val;
3655 case PACKET_AUXDATA:
3659 if (optlen < sizeof(val))
3661 if (copy_from_user(&val, optval, sizeof(val)))
3664 po->auxdata = !!val;
3667 case PACKET_ORIGDEV:
3671 if (optlen < sizeof(val))
3673 if (copy_from_user(&val, optval, sizeof(val)))
3676 po->origdev = !!val;
3679 case PACKET_VNET_HDR:
3683 if (sock->type != SOCK_RAW)
3685 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3687 if (optlen < sizeof(val))
3689 if (copy_from_user(&val, optval, sizeof(val)))
3692 po->has_vnet_hdr = !!val;
3695 case PACKET_TIMESTAMP:
3699 if (optlen != sizeof(val))
3701 if (copy_from_user(&val, optval, sizeof(val)))
3704 po->tp_tstamp = val;
3711 if (optlen != sizeof(val))
3713 if (copy_from_user(&val, optval, sizeof(val)))
3716 return fanout_add(sk, val & 0xffff, val >> 16);
3718 case PACKET_FANOUT_DATA:
3723 return fanout_set_data(po, optval, optlen);
3725 case PACKET_TX_HAS_OFF:
3729 if (optlen != sizeof(val))
3731 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3733 if (copy_from_user(&val, optval, sizeof(val)))
3735 po->tp_tx_has_off = !!val;
3738 case PACKET_QDISC_BYPASS:
3742 if (optlen != sizeof(val))
3744 if (copy_from_user(&val, optval, sizeof(val)))
3747 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3751 return -ENOPROTOOPT;
3755 static int packet_getsockopt(struct socket *sock, int level, int optname,
3756 char __user *optval, int __user *optlen)
3759 int val, lv = sizeof(val);
3760 struct sock *sk = sock->sk;
3761 struct packet_sock *po = pkt_sk(sk);
3763 union tpacket_stats_u st;
3764 struct tpacket_rollover_stats rstats;
3766 if (level != SOL_PACKET)
3767 return -ENOPROTOOPT;
3769 if (get_user(len, optlen))
3776 case PACKET_STATISTICS:
3777 spin_lock_bh(&sk->sk_receive_queue.lock);
3778 memcpy(&st, &po->stats, sizeof(st));
3779 memset(&po->stats, 0, sizeof(po->stats));
3780 spin_unlock_bh(&sk->sk_receive_queue.lock);
3782 if (po->tp_version == TPACKET_V3) {
3783 lv = sizeof(struct tpacket_stats_v3);
3784 st.stats3.tp_packets += st.stats3.tp_drops;
3787 lv = sizeof(struct tpacket_stats);
3788 st.stats1.tp_packets += st.stats1.tp_drops;
3793 case PACKET_AUXDATA:
3796 case PACKET_ORIGDEV:
3799 case PACKET_VNET_HDR:
3800 val = po->has_vnet_hdr;
3802 case PACKET_VERSION:
3803 val = po->tp_version;
3806 if (len > sizeof(int))
3808 if (copy_from_user(&val, optval, len))
3812 val = sizeof(struct tpacket_hdr);
3815 val = sizeof(struct tpacket2_hdr);
3818 val = sizeof(struct tpacket3_hdr);
3824 case PACKET_RESERVE:
3825 val = po->tp_reserve;
3830 case PACKET_TIMESTAMP:
3831 val = po->tp_tstamp;
3835 ((u32)po->fanout->id |
3836 ((u32)po->fanout->type << 16) |
3837 ((u32)po->fanout->flags << 24)) :
3840 case PACKET_ROLLOVER_STATS:
3843 rstats.tp_all = atomic_long_read(&po->rollover->num);
3844 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3845 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3847 lv = sizeof(rstats);
3849 case PACKET_TX_HAS_OFF:
3850 val = po->tp_tx_has_off;
3852 case PACKET_QDISC_BYPASS:
3853 val = packet_use_direct_xmit(po);
3856 return -ENOPROTOOPT;
3861 if (put_user(len, optlen))
3863 if (copy_to_user(optval, data, len))
3869 static int packet_notifier(struct notifier_block *this,
3870 unsigned long msg, void *ptr)
3873 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3874 struct net *net = dev_net(dev);
3877 sk_for_each_rcu(sk, &net->packet.sklist) {
3878 struct packet_sock *po = pkt_sk(sk);
3881 case NETDEV_UNREGISTER:
3883 packet_dev_mclist_delete(dev, &po->mclist);
3887 if (dev->ifindex == po->ifindex) {
3888 spin_lock(&po->bind_lock);
3890 __unregister_prot_hook(sk, false);
3891 sk->sk_err = ENETDOWN;
3892 if (!sock_flag(sk, SOCK_DEAD))
3893 sk->sk_error_report(sk);
3895 if (msg == NETDEV_UNREGISTER) {
3896 packet_cached_dev_reset(po);
3898 if (po->prot_hook.dev)
3899 dev_put(po->prot_hook.dev);
3900 po->prot_hook.dev = NULL;
3902 spin_unlock(&po->bind_lock);
3906 if (dev->ifindex == po->ifindex) {
3907 spin_lock(&po->bind_lock);
3909 register_prot_hook(sk);
3910 spin_unlock(&po->bind_lock);
3920 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3923 struct sock *sk = sock->sk;
3928 int amount = sk_wmem_alloc_get(sk);
3930 return put_user(amount, (int __user *)arg);
3934 struct sk_buff *skb;
3937 spin_lock_bh(&sk->sk_receive_queue.lock);
3938 skb = skb_peek(&sk->sk_receive_queue);
3941 spin_unlock_bh(&sk->sk_receive_queue.lock);
3942 return put_user(amount, (int __user *)arg);
3945 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3947 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3957 case SIOCGIFBRDADDR:
3958 case SIOCSIFBRDADDR:
3959 case SIOCGIFNETMASK:
3960 case SIOCSIFNETMASK:
3961 case SIOCGIFDSTADDR:
3962 case SIOCSIFDSTADDR:
3964 return inet_dgram_ops.ioctl(sock, cmd, arg);
3968 return -ENOIOCTLCMD;
3973 static unsigned int packet_poll(struct file *file, struct socket *sock,
3976 struct sock *sk = sock->sk;
3977 struct packet_sock *po = pkt_sk(sk);
3978 unsigned int mask = datagram_poll(file, sock, wait);
3980 spin_lock_bh(&sk->sk_receive_queue.lock);
3981 if (po->rx_ring.pg_vec) {
3982 if (!packet_previous_rx_frame(po, &po->rx_ring,
3984 mask |= POLLIN | POLLRDNORM;
3986 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
3988 spin_unlock_bh(&sk->sk_receive_queue.lock);
3989 spin_lock_bh(&sk->sk_write_queue.lock);
3990 if (po->tx_ring.pg_vec) {
3991 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3992 mask |= POLLOUT | POLLWRNORM;
3994 spin_unlock_bh(&sk->sk_write_queue.lock);
3999 /* Dirty? Well, I still did not learn better way to account
4003 static void packet_mm_open(struct vm_area_struct *vma)
4005 struct file *file = vma->vm_file;
4006 struct socket *sock = file->private_data;
4007 struct sock *sk = sock->sk;
4010 atomic_inc(&pkt_sk(sk)->mapped);
4013 static void packet_mm_close(struct vm_area_struct *vma)
4015 struct file *file = vma->vm_file;
4016 struct socket *sock = file->private_data;
4017 struct sock *sk = sock->sk;
4020 atomic_dec(&pkt_sk(sk)->mapped);
4023 static const struct vm_operations_struct packet_mmap_ops = {
4024 .open = packet_mm_open,
4025 .close = packet_mm_close,
4028 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4033 for (i = 0; i < len; i++) {
4034 if (likely(pg_vec[i].buffer)) {
4035 if (is_vmalloc_addr(pg_vec[i].buffer))
4036 vfree(pg_vec[i].buffer);
4038 free_pages((unsigned long)pg_vec[i].buffer,
4040 pg_vec[i].buffer = NULL;
4046 static char *alloc_one_pg_vec_page(unsigned long order)
4049 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4050 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4052 buffer = (char *) __get_free_pages(gfp_flags, order);
4056 /* __get_free_pages failed, fall back to vmalloc */
4057 buffer = vzalloc((1 << order) * PAGE_SIZE);
4061 /* vmalloc failed, lets dig into swap here */
4062 gfp_flags &= ~__GFP_NORETRY;
4063 buffer = (char *) __get_free_pages(gfp_flags, order);
4067 /* complete and utter failure */
4071 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4073 unsigned int block_nr = req->tp_block_nr;
4077 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4078 if (unlikely(!pg_vec))
4081 for (i = 0; i < block_nr; i++) {
4082 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4083 if (unlikely(!pg_vec[i].buffer))
4084 goto out_free_pgvec;
4091 free_pg_vec(pg_vec, order, block_nr);
4096 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4097 int closing, int tx_ring)
4099 struct pgv *pg_vec = NULL;
4100 struct packet_sock *po = pkt_sk(sk);
4101 int was_running, order = 0;
4102 struct packet_ring_buffer *rb;
4103 struct sk_buff_head *rb_queue;
4106 /* Added to avoid minimal code churn */
4107 struct tpacket_req *req = &req_u->req;
4109 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4110 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4111 WARN(1, "Tx-ring is not supported.\n");
4115 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4116 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4120 if (atomic_read(&po->mapped))
4122 if (packet_read_pending(rb))
4126 if (req->tp_block_nr) {
4127 /* Sanity tests and some calculations */
4129 if (unlikely(rb->pg_vec))
4132 switch (po->tp_version) {
4134 po->tp_hdrlen = TPACKET_HDRLEN;
4137 po->tp_hdrlen = TPACKET2_HDRLEN;
4140 po->tp_hdrlen = TPACKET3_HDRLEN;
4145 if (unlikely((int)req->tp_block_size <= 0))
4147 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4149 if (po->tp_version >= TPACKET_V3 &&
4150 (int)(req->tp_block_size -
4151 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4153 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4156 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4159 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4160 if (unlikely(rb->frames_per_block == 0))
4162 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4167 order = get_order(req->tp_block_size);
4168 pg_vec = alloc_pg_vec(req, order);
4169 if (unlikely(!pg_vec))
4171 switch (po->tp_version) {
4173 /* Transmit path is not supported. We checked
4174 * it above but just being paranoid
4177 init_prb_bdqc(po, rb, pg_vec, req_u);
4186 if (unlikely(req->tp_frame_nr))
4192 /* Detach socket from network */
4193 spin_lock(&po->bind_lock);
4194 was_running = po->running;
4198 __unregister_prot_hook(sk, false);
4200 spin_unlock(&po->bind_lock);
4205 mutex_lock(&po->pg_vec_lock);
4206 if (closing || atomic_read(&po->mapped) == 0) {
4208 spin_lock_bh(&rb_queue->lock);
4209 swap(rb->pg_vec, pg_vec);
4210 rb->frame_max = (req->tp_frame_nr - 1);
4212 rb->frame_size = req->tp_frame_size;
4213 spin_unlock_bh(&rb_queue->lock);
4215 swap(rb->pg_vec_order, order);
4216 swap(rb->pg_vec_len, req->tp_block_nr);
4218 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4219 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4220 tpacket_rcv : packet_rcv;
4221 skb_queue_purge(rb_queue);
4222 if (atomic_read(&po->mapped))
4223 pr_err("packet_mmap: vma is busy: %d\n",
4224 atomic_read(&po->mapped));
4226 mutex_unlock(&po->pg_vec_lock);
4228 spin_lock(&po->bind_lock);
4231 register_prot_hook(sk);
4233 spin_unlock(&po->bind_lock);
4234 if (closing && (po->tp_version > TPACKET_V2)) {
4235 /* Because we don't support block-based V3 on tx-ring */
4237 prb_shutdown_retire_blk_timer(po, rb_queue);
4242 free_pg_vec(pg_vec, order, req->tp_block_nr);
4247 static int packet_mmap(struct file *file, struct socket *sock,
4248 struct vm_area_struct *vma)
4250 struct sock *sk = sock->sk;
4251 struct packet_sock *po = pkt_sk(sk);
4252 unsigned long size, expected_size;
4253 struct packet_ring_buffer *rb;
4254 unsigned long start;
4261 mutex_lock(&po->pg_vec_lock);
4264 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4266 expected_size += rb->pg_vec_len
4272 if (expected_size == 0)
4275 size = vma->vm_end - vma->vm_start;
4276 if (size != expected_size)
4279 start = vma->vm_start;
4280 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4281 if (rb->pg_vec == NULL)
4284 for (i = 0; i < rb->pg_vec_len; i++) {
4286 void *kaddr = rb->pg_vec[i].buffer;
4289 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4290 page = pgv_to_page(kaddr);
4291 err = vm_insert_page(vma, start, page);
4300 atomic_inc(&po->mapped);
4301 vma->vm_ops = &packet_mmap_ops;
4305 mutex_unlock(&po->pg_vec_lock);
4309 static const struct proto_ops packet_ops_spkt = {
4310 .family = PF_PACKET,
4311 .owner = THIS_MODULE,
4312 .release = packet_release,
4313 .bind = packet_bind_spkt,
4314 .connect = sock_no_connect,
4315 .socketpair = sock_no_socketpair,
4316 .accept = sock_no_accept,
4317 .getname = packet_getname_spkt,
4318 .poll = datagram_poll,
4319 .ioctl = packet_ioctl,
4320 .listen = sock_no_listen,
4321 .shutdown = sock_no_shutdown,
4322 .setsockopt = sock_no_setsockopt,
4323 .getsockopt = sock_no_getsockopt,
4324 .sendmsg = packet_sendmsg_spkt,
4325 .recvmsg = packet_recvmsg,
4326 .mmap = sock_no_mmap,
4327 .sendpage = sock_no_sendpage,
4330 static const struct proto_ops packet_ops = {
4331 .family = PF_PACKET,
4332 .owner = THIS_MODULE,
4333 .release = packet_release,
4334 .bind = packet_bind,
4335 .connect = sock_no_connect,
4336 .socketpair = sock_no_socketpair,
4337 .accept = sock_no_accept,
4338 .getname = packet_getname,
4339 .poll = packet_poll,
4340 .ioctl = packet_ioctl,
4341 .listen = sock_no_listen,
4342 .shutdown = sock_no_shutdown,
4343 .setsockopt = packet_setsockopt,
4344 .getsockopt = packet_getsockopt,
4345 .sendmsg = packet_sendmsg,
4346 .recvmsg = packet_recvmsg,
4347 .mmap = packet_mmap,
4348 .sendpage = sock_no_sendpage,
4351 static const struct net_proto_family packet_family_ops = {
4352 .family = PF_PACKET,
4353 .create = packet_create,
4354 .owner = THIS_MODULE,
4357 static struct notifier_block packet_netdev_notifier = {
4358 .notifier_call = packet_notifier,
4361 #ifdef CONFIG_PROC_FS
4363 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4366 struct net *net = seq_file_net(seq);
4369 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4372 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4374 struct net *net = seq_file_net(seq);
4375 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4378 static void packet_seq_stop(struct seq_file *seq, void *v)
4384 static int packet_seq_show(struct seq_file *seq, void *v)
4386 if (v == SEQ_START_TOKEN)
4387 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4389 struct sock *s = sk_entry(v);
4390 const struct packet_sock *po = pkt_sk(s);
4393 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4395 atomic_read(&s->sk_refcnt),
4400 atomic_read(&s->sk_rmem_alloc),
4401 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4408 static const struct seq_operations packet_seq_ops = {
4409 .start = packet_seq_start,
4410 .next = packet_seq_next,
4411 .stop = packet_seq_stop,
4412 .show = packet_seq_show,
4415 static int packet_seq_open(struct inode *inode, struct file *file)
4417 return seq_open_net(inode, file, &packet_seq_ops,
4418 sizeof(struct seq_net_private));
4421 static const struct file_operations packet_seq_fops = {
4422 .owner = THIS_MODULE,
4423 .open = packet_seq_open,
4425 .llseek = seq_lseek,
4426 .release = seq_release_net,
4431 static int __net_init packet_net_init(struct net *net)
4433 mutex_init(&net->packet.sklist_lock);
4434 INIT_HLIST_HEAD(&net->packet.sklist);
4436 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4442 static void __net_exit packet_net_exit(struct net *net)
4444 remove_proc_entry("packet", net->proc_net);
4447 static struct pernet_operations packet_net_ops = {
4448 .init = packet_net_init,
4449 .exit = packet_net_exit,
4453 static void __exit packet_exit(void)
4455 unregister_netdevice_notifier(&packet_netdev_notifier);
4456 unregister_pernet_subsys(&packet_net_ops);
4457 sock_unregister(PF_PACKET);
4458 proto_unregister(&packet_proto);
4461 static int __init packet_init(void)
4463 int rc = proto_register(&packet_proto, 0);
4468 sock_register(&packet_family_ops);
4469 register_pernet_subsys(&packet_net_ops);
4470 register_netdevice_notifier(&packet_netdev_notifier);
4475 module_init(packet_init);
4476 module_exit(packet_exit);
4477 MODULE_LICENSE("GPL");
4478 MODULE_ALIAS_NETPROTO(PF_PACKET);