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);
1964 * This function makes lazy skb cloning in hope that most of packets
1965 * are discarded by BPF.
1967 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1968 * and skb->cb are mangled. It works because (and until) packets
1969 * falling here are owned by current CPU. Output packets are cloned
1970 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1971 * sequencially, so that if we return skb to original state on exit,
1972 * we will not harm anyone.
1975 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1976 struct packet_type *pt, struct net_device *orig_dev)
1979 struct sockaddr_ll *sll;
1980 struct packet_sock *po;
1981 u8 *skb_head = skb->data;
1982 int skb_len = skb->len;
1983 unsigned int snaplen, res;
1985 if (skb->pkt_type == PACKET_LOOPBACK)
1988 sk = pt->af_packet_priv;
1991 if (!net_eq(dev_net(dev), sock_net(sk)))
1996 if (dev->header_ops) {
1997 /* The device has an explicit notion of ll header,
1998 * exported to higher levels.
2000 * Otherwise, the device hides details of its frame
2001 * structure, so that corresponding packet head is
2002 * never delivered to user.
2004 if (sk->sk_type != SOCK_DGRAM)
2005 skb_push(skb, skb->data - skb_mac_header(skb));
2006 else if (skb->pkt_type == PACKET_OUTGOING) {
2007 /* Special case: outgoing packets have ll header at head */
2008 skb_pull(skb, skb_network_offset(skb));
2014 res = run_filter(skb, sk, snaplen);
2016 goto drop_n_restore;
2020 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2023 if (skb_shared(skb)) {
2024 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2028 if (skb_head != skb->data) {
2029 skb->data = skb_head;
2036 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2038 sll = &PACKET_SKB_CB(skb)->sa.ll;
2039 sll->sll_hatype = dev->type;
2040 sll->sll_pkttype = skb->pkt_type;
2041 if (unlikely(po->origdev))
2042 sll->sll_ifindex = orig_dev->ifindex;
2044 sll->sll_ifindex = dev->ifindex;
2046 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2048 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2049 * Use their space for storing the original skb length.
2051 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2053 if (pskb_trim(skb, snaplen))
2056 skb_set_owner_r(skb, sk);
2060 /* drop conntrack reference */
2063 spin_lock(&sk->sk_receive_queue.lock);
2064 po->stats.stats1.tp_packets++;
2065 sock_skb_set_dropcount(sk, skb);
2066 __skb_queue_tail(&sk->sk_receive_queue, skb);
2067 spin_unlock(&sk->sk_receive_queue.lock);
2068 sk->sk_data_ready(sk);
2072 spin_lock(&sk->sk_receive_queue.lock);
2073 po->stats.stats1.tp_drops++;
2074 atomic_inc(&sk->sk_drops);
2075 spin_unlock(&sk->sk_receive_queue.lock);
2078 if (skb_head != skb->data && skb_shared(skb)) {
2079 skb->data = skb_head;
2087 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2088 struct packet_type *pt, struct net_device *orig_dev)
2091 struct packet_sock *po;
2092 struct sockaddr_ll *sll;
2093 union tpacket_uhdr h;
2094 u8 *skb_head = skb->data;
2095 int skb_len = skb->len;
2096 unsigned int snaplen, res;
2097 unsigned long status = TP_STATUS_USER;
2098 unsigned short macoff, netoff, hdrlen;
2099 struct sk_buff *copy_skb = NULL;
2103 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2104 * We may add members to them until current aligned size without forcing
2105 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2107 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2108 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2110 if (skb->pkt_type == PACKET_LOOPBACK)
2113 sk = pt->af_packet_priv;
2116 if (!net_eq(dev_net(dev), sock_net(sk)))
2119 if (dev->header_ops) {
2120 if (sk->sk_type != SOCK_DGRAM)
2121 skb_push(skb, skb->data - skb_mac_header(skb));
2122 else if (skb->pkt_type == PACKET_OUTGOING) {
2123 /* Special case: outgoing packets have ll header at head */
2124 skb_pull(skb, skb_network_offset(skb));
2130 res = run_filter(skb, sk, snaplen);
2132 goto drop_n_restore;
2134 if (skb->ip_summed == CHECKSUM_PARTIAL)
2135 status |= TP_STATUS_CSUMNOTREADY;
2136 else if (skb->pkt_type != PACKET_OUTGOING &&
2137 (skb->ip_summed == CHECKSUM_COMPLETE ||
2138 skb_csum_unnecessary(skb)))
2139 status |= TP_STATUS_CSUM_VALID;
2144 if (sk->sk_type == SOCK_DGRAM) {
2145 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2148 unsigned int maclen = skb_network_offset(skb);
2149 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2150 (maclen < 16 ? 16 : maclen)) +
2152 macoff = netoff - maclen;
2154 if (po->tp_version <= TPACKET_V2) {
2155 if (macoff + snaplen > po->rx_ring.frame_size) {
2156 if (po->copy_thresh &&
2157 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2158 if (skb_shared(skb)) {
2159 copy_skb = skb_clone(skb, GFP_ATOMIC);
2161 copy_skb = skb_get(skb);
2162 skb_head = skb->data;
2165 skb_set_owner_r(copy_skb, sk);
2167 snaplen = po->rx_ring.frame_size - macoff;
2168 if ((int)snaplen < 0)
2171 } else if (unlikely(macoff + snaplen >
2172 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2175 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2176 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2177 snaplen, nval, macoff);
2179 if (unlikely((int)snaplen < 0)) {
2181 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2184 spin_lock(&sk->sk_receive_queue.lock);
2185 h.raw = packet_current_rx_frame(po, skb,
2186 TP_STATUS_KERNEL, (macoff+snaplen));
2189 if (po->tp_version <= TPACKET_V2) {
2190 packet_increment_rx_head(po, &po->rx_ring);
2192 * LOSING will be reported till you read the stats,
2193 * because it's COR - Clear On Read.
2194 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2197 if (po->stats.stats1.tp_drops)
2198 status |= TP_STATUS_LOSING;
2200 po->stats.stats1.tp_packets++;
2202 status |= TP_STATUS_COPY;
2203 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2205 spin_unlock(&sk->sk_receive_queue.lock);
2207 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2209 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2210 getnstimeofday(&ts);
2212 status |= ts_status;
2214 switch (po->tp_version) {
2216 h.h1->tp_len = skb->len;
2217 h.h1->tp_snaplen = snaplen;
2218 h.h1->tp_mac = macoff;
2219 h.h1->tp_net = netoff;
2220 h.h1->tp_sec = ts.tv_sec;
2221 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2222 hdrlen = sizeof(*h.h1);
2225 h.h2->tp_len = skb->len;
2226 h.h2->tp_snaplen = snaplen;
2227 h.h2->tp_mac = macoff;
2228 h.h2->tp_net = netoff;
2229 h.h2->tp_sec = ts.tv_sec;
2230 h.h2->tp_nsec = ts.tv_nsec;
2231 if (skb_vlan_tag_present(skb)) {
2232 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2233 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2234 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2236 h.h2->tp_vlan_tci = 0;
2237 h.h2->tp_vlan_tpid = 0;
2239 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2240 hdrlen = sizeof(*h.h2);
2243 /* tp_nxt_offset,vlan are already populated above.
2244 * So DONT clear those fields here
2246 h.h3->tp_status |= status;
2247 h.h3->tp_len = skb->len;
2248 h.h3->tp_snaplen = snaplen;
2249 h.h3->tp_mac = macoff;
2250 h.h3->tp_net = netoff;
2251 h.h3->tp_sec = ts.tv_sec;
2252 h.h3->tp_nsec = ts.tv_nsec;
2253 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2254 hdrlen = sizeof(*h.h3);
2260 sll = h.raw + TPACKET_ALIGN(hdrlen);
2261 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2262 sll->sll_family = AF_PACKET;
2263 sll->sll_hatype = dev->type;
2264 sll->sll_protocol = skb->protocol;
2265 sll->sll_pkttype = skb->pkt_type;
2266 if (unlikely(po->origdev))
2267 sll->sll_ifindex = orig_dev->ifindex;
2269 sll->sll_ifindex = dev->ifindex;
2273 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2274 if (po->tp_version <= TPACKET_V2) {
2277 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2280 for (start = h.raw; start < end; start += PAGE_SIZE)
2281 flush_dcache_page(pgv_to_page(start));
2286 if (po->tp_version <= TPACKET_V2) {
2287 __packet_set_status(po, h.raw, status);
2288 sk->sk_data_ready(sk);
2290 prb_clear_blk_fill_status(&po->rx_ring);
2294 if (skb_head != skb->data && skb_shared(skb)) {
2295 skb->data = skb_head;
2303 po->stats.stats1.tp_drops++;
2304 spin_unlock(&sk->sk_receive_queue.lock);
2306 sk->sk_data_ready(sk);
2307 kfree_skb(copy_skb);
2308 goto drop_n_restore;
2311 static void tpacket_destruct_skb(struct sk_buff *skb)
2313 struct packet_sock *po = pkt_sk(skb->sk);
2315 if (likely(po->tx_ring.pg_vec)) {
2319 ph = skb_shinfo(skb)->destructor_arg;
2320 packet_dec_pending(&po->tx_ring);
2322 ts = __packet_set_timestamp(po, ph, skb);
2323 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2329 static bool ll_header_truncated(const struct net_device *dev, int len)
2331 /* net device doesn't like empty head */
2332 if (unlikely(len <= dev->hard_header_len)) {
2333 net_warn_ratelimited("%s: packet size is too short (%d <= %d)\n",
2334 current->comm, len, dev->hard_header_len);
2341 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2342 void *frame, struct net_device *dev, int size_max,
2343 __be16 proto, unsigned char *addr, int hlen)
2345 union tpacket_uhdr ph;
2346 int to_write, offset, len, tp_len, nr_frags, len_max;
2347 struct socket *sock = po->sk.sk_socket;
2354 skb->protocol = proto;
2356 skb->priority = po->sk.sk_priority;
2357 skb->mark = po->sk.sk_mark;
2358 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2359 skb_shinfo(skb)->destructor_arg = ph.raw;
2361 switch (po->tp_version) {
2363 tp_len = ph.h2->tp_len;
2366 tp_len = ph.h1->tp_len;
2369 if (unlikely(tp_len > size_max)) {
2370 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2374 skb_reserve(skb, hlen);
2375 skb_reset_network_header(skb);
2377 if (unlikely(po->tp_tx_has_off)) {
2378 int off_min, off_max, off;
2379 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2380 off_max = po->tx_ring.frame_size - tp_len;
2381 if (sock->type == SOCK_DGRAM) {
2382 switch (po->tp_version) {
2384 off = ph.h2->tp_net;
2387 off = ph.h1->tp_net;
2391 switch (po->tp_version) {
2393 off = ph.h2->tp_mac;
2396 off = ph.h1->tp_mac;
2400 if (unlikely((off < off_min) || (off_max < off)))
2402 data = ph.raw + off;
2404 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2408 if (sock->type == SOCK_DGRAM) {
2409 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2411 if (unlikely(err < 0))
2413 } else if (dev->hard_header_len) {
2414 if (ll_header_truncated(dev, tp_len))
2417 skb_push(skb, dev->hard_header_len);
2418 err = skb_store_bits(skb, 0, data,
2419 dev->hard_header_len);
2423 data += dev->hard_header_len;
2424 to_write -= dev->hard_header_len;
2427 offset = offset_in_page(data);
2428 len_max = PAGE_SIZE - offset;
2429 len = ((to_write > len_max) ? len_max : to_write);
2431 skb->data_len = to_write;
2432 skb->len += to_write;
2433 skb->truesize += to_write;
2434 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2436 while (likely(to_write)) {
2437 nr_frags = skb_shinfo(skb)->nr_frags;
2439 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2440 pr_err("Packet exceed the number of skb frags(%lu)\n",
2445 page = pgv_to_page(data);
2447 flush_dcache_page(page);
2449 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2452 len_max = PAGE_SIZE;
2453 len = ((to_write > len_max) ? len_max : to_write);
2456 skb_probe_transport_header(skb, 0);
2461 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2463 struct sk_buff *skb;
2464 struct net_device *dev;
2466 int err, reserve = 0;
2468 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2469 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2470 int tp_len, size_max;
2471 unsigned char *addr;
2473 int status = TP_STATUS_AVAILABLE;
2476 mutex_lock(&po->pg_vec_lock);
2478 if (likely(saddr == NULL)) {
2479 dev = packet_cached_dev_get(po);
2484 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2486 if (msg->msg_namelen < (saddr->sll_halen
2487 + offsetof(struct sockaddr_ll,
2490 proto = saddr->sll_protocol;
2491 addr = saddr->sll_addr;
2492 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2496 if (unlikely(dev == NULL))
2499 if (unlikely(!(dev->flags & IFF_UP)))
2502 reserve = dev->hard_header_len + VLAN_HLEN;
2503 size_max = po->tx_ring.frame_size
2504 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2506 if (size_max > dev->mtu + reserve)
2507 size_max = dev->mtu + reserve;
2510 ph = packet_current_frame(po, &po->tx_ring,
2511 TP_STATUS_SEND_REQUEST);
2512 if (unlikely(ph == NULL)) {
2513 if (need_wait && need_resched())
2518 status = TP_STATUS_SEND_REQUEST;
2519 hlen = LL_RESERVED_SPACE(dev);
2520 tlen = dev->needed_tailroom;
2521 skb = sock_alloc_send_skb(&po->sk,
2522 hlen + tlen + sizeof(struct sockaddr_ll),
2525 if (unlikely(skb == NULL)) {
2526 /* we assume the socket was initially writeable ... */
2527 if (likely(len_sum > 0))
2531 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2533 if (likely(tp_len >= 0) &&
2534 tp_len > dev->mtu + dev->hard_header_len &&
2535 !packet_extra_vlan_len_allowed(dev, skb))
2538 if (unlikely(tp_len < 0)) {
2540 __packet_set_status(po, ph,
2541 TP_STATUS_AVAILABLE);
2542 packet_increment_head(&po->tx_ring);
2546 status = TP_STATUS_WRONG_FORMAT;
2552 packet_pick_tx_queue(dev, skb);
2554 skb->destructor = tpacket_destruct_skb;
2555 __packet_set_status(po, ph, TP_STATUS_SENDING);
2556 packet_inc_pending(&po->tx_ring);
2558 status = TP_STATUS_SEND_REQUEST;
2559 err = po->xmit(skb);
2560 if (unlikely(err > 0)) {
2561 err = net_xmit_errno(err);
2562 if (err && __packet_get_status(po, ph) ==
2563 TP_STATUS_AVAILABLE) {
2564 /* skb was destructed already */
2569 * skb was dropped but not destructed yet;
2570 * let's treat it like congestion or err < 0
2574 packet_increment_head(&po->tx_ring);
2576 } while (likely((ph != NULL) ||
2577 /* Note: packet_read_pending() might be slow if we have
2578 * to call it as it's per_cpu variable, but in fast-path
2579 * we already short-circuit the loop with the first
2580 * condition, and luckily don't have to go that path
2583 (need_wait && packet_read_pending(&po->tx_ring))));
2589 __packet_set_status(po, ph, status);
2594 mutex_unlock(&po->pg_vec_lock);
2598 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2599 size_t reserve, size_t len,
2600 size_t linear, int noblock,
2603 struct sk_buff *skb;
2605 /* Under a page? Don't bother with paged skb. */
2606 if (prepad + len < PAGE_SIZE || !linear)
2609 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2614 skb_reserve(skb, reserve);
2615 skb_put(skb, linear);
2616 skb->data_len = len - linear;
2617 skb->len += len - linear;
2622 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2624 struct sock *sk = sock->sk;
2625 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2626 struct sk_buff *skb;
2627 struct net_device *dev;
2629 unsigned char *addr;
2630 int err, reserve = 0;
2631 struct sockcm_cookie sockc;
2632 struct virtio_net_hdr vnet_hdr = { 0 };
2635 struct packet_sock *po = pkt_sk(sk);
2636 unsigned short gso_type = 0;
2642 * Get and verify the address.
2645 if (likely(saddr == NULL)) {
2646 dev = packet_cached_dev_get(po);
2651 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2653 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2655 proto = saddr->sll_protocol;
2656 addr = saddr->sll_addr;
2657 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2661 if (unlikely(dev == NULL))
2664 if (unlikely(!(dev->flags & IFF_UP)))
2667 sockc.mark = sk->sk_mark;
2668 if (msg->msg_controllen) {
2669 err = sock_cmsg_send(sk, msg, &sockc);
2674 if (sock->type == SOCK_RAW)
2675 reserve = dev->hard_header_len;
2676 if (po->has_vnet_hdr) {
2677 vnet_hdr_len = sizeof(vnet_hdr);
2680 if (len < vnet_hdr_len)
2683 len -= vnet_hdr_len;
2686 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter);
2687 if (n != vnet_hdr_len)
2690 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2691 (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2692 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 >
2693 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len)))
2694 vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(),
2695 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2696 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2);
2699 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len)
2702 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2703 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2704 case VIRTIO_NET_HDR_GSO_TCPV4:
2705 gso_type = SKB_GSO_TCPV4;
2707 case VIRTIO_NET_HDR_GSO_TCPV6:
2708 gso_type = SKB_GSO_TCPV6;
2710 case VIRTIO_NET_HDR_GSO_UDP:
2711 gso_type = SKB_GSO_UDP;
2717 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2718 gso_type |= SKB_GSO_TCP_ECN;
2720 if (vnet_hdr.gso_size == 0)
2726 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2727 if (!netif_supports_nofcs(dev)) {
2728 err = -EPROTONOSUPPORT;
2731 extra_len = 4; /* We're doing our own CRC */
2735 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2739 hlen = LL_RESERVED_SPACE(dev);
2740 tlen = dev->needed_tailroom;
2741 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
2742 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len),
2743 msg->msg_flags & MSG_DONTWAIT, &err);
2747 skb_set_network_header(skb, reserve);
2750 if (sock->type == SOCK_DGRAM) {
2751 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2752 if (unlikely(offset < 0))
2755 if (ll_header_truncated(dev, len))
2759 /* Returns -EFAULT on error */
2760 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2764 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2766 if (!gso_type && (len > dev->mtu + reserve + extra_len) &&
2767 !packet_extra_vlan_len_allowed(dev, skb)) {
2772 skb->protocol = proto;
2774 skb->priority = sk->sk_priority;
2775 skb->mark = sockc.mark;
2777 packet_pick_tx_queue(dev, skb);
2779 if (po->has_vnet_hdr) {
2780 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2781 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start);
2782 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset);
2783 if (!skb_partial_csum_set(skb, s, o)) {
2789 skb_shinfo(skb)->gso_size =
2790 __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size);
2791 skb_shinfo(skb)->gso_type = gso_type;
2793 /* Header must be checked, and gso_segs computed. */
2794 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2795 skb_shinfo(skb)->gso_segs = 0;
2797 len += vnet_hdr_len;
2800 skb_probe_transport_header(skb, reserve);
2802 if (unlikely(extra_len == 4))
2805 err = po->xmit(skb);
2806 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2822 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2824 struct sock *sk = sock->sk;
2825 struct packet_sock *po = pkt_sk(sk);
2827 if (po->tx_ring.pg_vec)
2828 return tpacket_snd(po, msg);
2830 return packet_snd(sock, msg, len);
2834 * Close a PACKET socket. This is fairly simple. We immediately go
2835 * to 'closed' state and remove our protocol entry in the device list.
2838 static int packet_release(struct socket *sock)
2840 struct sock *sk = sock->sk;
2841 struct packet_sock *po;
2843 union tpacket_req_u req_u;
2851 mutex_lock(&net->packet.sklist_lock);
2852 sk_del_node_init_rcu(sk);
2853 mutex_unlock(&net->packet.sklist_lock);
2856 sock_prot_inuse_add(net, sk->sk_prot, -1);
2859 spin_lock(&po->bind_lock);
2860 unregister_prot_hook(sk, false);
2861 packet_cached_dev_reset(po);
2863 if (po->prot_hook.dev) {
2864 dev_put(po->prot_hook.dev);
2865 po->prot_hook.dev = NULL;
2867 spin_unlock(&po->bind_lock);
2869 packet_flush_mclist(sk);
2871 if (po->rx_ring.pg_vec) {
2872 memset(&req_u, 0, sizeof(req_u));
2873 packet_set_ring(sk, &req_u, 1, 0);
2876 if (po->tx_ring.pg_vec) {
2877 memset(&req_u, 0, sizeof(req_u));
2878 packet_set_ring(sk, &req_u, 1, 1);
2885 * Now the socket is dead. No more input will appear.
2892 skb_queue_purge(&sk->sk_receive_queue);
2893 packet_free_pending(po);
2894 sk_refcnt_debug_release(sk);
2901 * Attach a packet hook.
2904 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2907 struct packet_sock *po = pkt_sk(sk);
2908 struct net_device *dev_curr;
2911 struct net_device *dev = NULL;
2913 bool unlisted = false;
2919 spin_lock(&po->bind_lock);
2923 dev = dev_get_by_name_rcu(sock_net(sk), name);
2928 } else if (ifindex) {
2929 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
2939 proto_curr = po->prot_hook.type;
2940 dev_curr = po->prot_hook.dev;
2942 need_rehook = proto_curr != proto || dev_curr != dev;
2947 __unregister_prot_hook(sk, true);
2949 dev_curr = po->prot_hook.dev;
2951 unlisted = !dev_get_by_index_rcu(sock_net(sk),
2956 po->prot_hook.type = proto;
2958 if (unlikely(unlisted)) {
2960 po->prot_hook.dev = NULL;
2962 packet_cached_dev_reset(po);
2964 po->prot_hook.dev = dev;
2965 po->ifindex = dev ? dev->ifindex : 0;
2966 packet_cached_dev_assign(po, dev);
2972 if (proto == 0 || !need_rehook)
2975 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
2976 register_prot_hook(sk);
2978 sk->sk_err = ENETDOWN;
2979 if (!sock_flag(sk, SOCK_DEAD))
2980 sk->sk_error_report(sk);
2985 spin_unlock(&po->bind_lock);
2991 * Bind a packet socket to a device
2994 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2997 struct sock *sk = sock->sk;
3004 if (addr_len != sizeof(struct sockaddr))
3006 strlcpy(name, uaddr->sa_data, sizeof(name));
3008 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3011 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3013 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3014 struct sock *sk = sock->sk;
3020 if (addr_len < sizeof(struct sockaddr_ll))
3022 if (sll->sll_family != AF_PACKET)
3025 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3026 sll->sll_protocol ? : pkt_sk(sk)->num);
3029 static struct proto packet_proto = {
3031 .owner = THIS_MODULE,
3032 .obj_size = sizeof(struct packet_sock),
3036 * Create a packet of type SOCK_PACKET.
3039 static int packet_create(struct net *net, struct socket *sock, int protocol,
3043 struct packet_sock *po;
3044 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3047 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3049 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3050 sock->type != SOCK_PACKET)
3051 return -ESOCKTNOSUPPORT;
3053 sock->state = SS_UNCONNECTED;
3056 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3060 sock->ops = &packet_ops;
3061 if (sock->type == SOCK_PACKET)
3062 sock->ops = &packet_ops_spkt;
3064 sock_init_data(sock, sk);
3067 sk->sk_family = PF_PACKET;
3069 po->xmit = dev_queue_xmit;
3071 err = packet_alloc_pending(po);
3075 packet_cached_dev_reset(po);
3077 sk->sk_destruct = packet_sock_destruct;
3078 sk_refcnt_debug_inc(sk);
3081 * Attach a protocol block
3084 spin_lock_init(&po->bind_lock);
3085 mutex_init(&po->pg_vec_lock);
3086 po->rollover = NULL;
3087 po->prot_hook.func = packet_rcv;
3089 if (sock->type == SOCK_PACKET)
3090 po->prot_hook.func = packet_rcv_spkt;
3092 po->prot_hook.af_packet_priv = sk;
3095 po->prot_hook.type = proto;
3096 register_prot_hook(sk);
3099 mutex_lock(&net->packet.sklist_lock);
3100 sk_add_node_rcu(sk, &net->packet.sklist);
3101 mutex_unlock(&net->packet.sklist_lock);
3104 sock_prot_inuse_add(net, &packet_proto, 1);
3115 * Pull a packet from our receive queue and hand it to the user.
3116 * If necessary we block.
3119 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3122 struct sock *sk = sock->sk;
3123 struct sk_buff *skb;
3125 int vnet_hdr_len = 0;
3126 unsigned int origlen = 0;
3129 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3133 /* What error should we return now? EUNATTACH? */
3134 if (pkt_sk(sk)->ifindex < 0)
3138 if (flags & MSG_ERRQUEUE) {
3139 err = sock_recv_errqueue(sk, msg, len,
3140 SOL_PACKET, PACKET_TX_TIMESTAMP);
3145 * Call the generic datagram receiver. This handles all sorts
3146 * of horrible races and re-entrancy so we can forget about it
3147 * in the protocol layers.
3149 * Now it will return ENETDOWN, if device have just gone down,
3150 * but then it will block.
3153 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3156 * An error occurred so return it. Because skb_recv_datagram()
3157 * handles the blocking we don't see and worry about blocking
3164 if (pkt_sk(sk)->pressure)
3165 packet_rcv_has_room(pkt_sk(sk), NULL);
3167 if (pkt_sk(sk)->has_vnet_hdr) {
3168 struct virtio_net_hdr vnet_hdr = { 0 };
3171 vnet_hdr_len = sizeof(vnet_hdr);
3172 if (len < vnet_hdr_len)
3175 len -= vnet_hdr_len;
3177 if (skb_is_gso(skb)) {
3178 struct skb_shared_info *sinfo = skb_shinfo(skb);
3180 /* This is a hint as to how much should be linear. */
3182 __cpu_to_virtio16(vio_le(), skb_headlen(skb));
3184 __cpu_to_virtio16(vio_le(), sinfo->gso_size);
3185 if (sinfo->gso_type & SKB_GSO_TCPV4)
3186 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
3187 else if (sinfo->gso_type & SKB_GSO_TCPV6)
3188 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
3189 else if (sinfo->gso_type & SKB_GSO_UDP)
3190 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
3191 else if (sinfo->gso_type & SKB_GSO_FCOE)
3195 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
3196 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
3198 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
3200 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3201 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
3202 vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(),
3203 skb_checksum_start_offset(skb));
3204 vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(),
3206 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3207 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
3208 } /* else everything is zero */
3210 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);
3215 /* You lose any data beyond the buffer you gave. If it worries
3216 * a user program they can ask the device for its MTU
3222 msg->msg_flags |= MSG_TRUNC;
3225 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3229 if (sock->type != SOCK_PACKET) {
3230 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3232 /* Original length was stored in sockaddr_ll fields */
3233 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3234 sll->sll_family = AF_PACKET;
3235 sll->sll_protocol = skb->protocol;
3238 sock_recv_ts_and_drops(msg, sk, skb);
3240 if (msg->msg_name) {
3241 /* If the address length field is there to be filled
3242 * in, we fill it in now.
3244 if (sock->type == SOCK_PACKET) {
3245 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3246 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3248 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3250 msg->msg_namelen = sll->sll_halen +
3251 offsetof(struct sockaddr_ll, sll_addr);
3253 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3257 if (pkt_sk(sk)->auxdata) {
3258 struct tpacket_auxdata aux;
3260 aux.tp_status = TP_STATUS_USER;
3261 if (skb->ip_summed == CHECKSUM_PARTIAL)
3262 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3263 else if (skb->pkt_type != PACKET_OUTGOING &&
3264 (skb->ip_summed == CHECKSUM_COMPLETE ||
3265 skb_csum_unnecessary(skb)))
3266 aux.tp_status |= TP_STATUS_CSUM_VALID;
3268 aux.tp_len = origlen;
3269 aux.tp_snaplen = skb->len;
3271 aux.tp_net = skb_network_offset(skb);
3272 if (skb_vlan_tag_present(skb)) {
3273 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3274 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3275 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3277 aux.tp_vlan_tci = 0;
3278 aux.tp_vlan_tpid = 0;
3280 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3284 * Free or return the buffer as appropriate. Again this
3285 * hides all the races and re-entrancy issues from us.
3287 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3290 skb_free_datagram(sk, skb);
3295 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3296 int *uaddr_len, int peer)
3298 struct net_device *dev;
3299 struct sock *sk = sock->sk;
3304 uaddr->sa_family = AF_PACKET;
3305 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3307 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3309 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3311 *uaddr_len = sizeof(*uaddr);
3316 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3317 int *uaddr_len, int peer)
3319 struct net_device *dev;
3320 struct sock *sk = sock->sk;
3321 struct packet_sock *po = pkt_sk(sk);
3322 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3327 sll->sll_family = AF_PACKET;
3328 sll->sll_ifindex = po->ifindex;
3329 sll->sll_protocol = po->num;
3330 sll->sll_pkttype = 0;
3332 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3334 sll->sll_hatype = dev->type;
3335 sll->sll_halen = dev->addr_len;
3336 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3338 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3342 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3347 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3351 case PACKET_MR_MULTICAST:
3352 if (i->alen != dev->addr_len)
3355 return dev_mc_add(dev, i->addr);
3357 return dev_mc_del(dev, i->addr);
3359 case PACKET_MR_PROMISC:
3360 return dev_set_promiscuity(dev, what);
3361 case PACKET_MR_ALLMULTI:
3362 return dev_set_allmulti(dev, what);
3363 case PACKET_MR_UNICAST:
3364 if (i->alen != dev->addr_len)
3367 return dev_uc_add(dev, i->addr);
3369 return dev_uc_del(dev, i->addr);
3377 static void packet_dev_mclist_delete(struct net_device *dev,
3378 struct packet_mclist **mlp)
3380 struct packet_mclist *ml;
3382 while ((ml = *mlp) != NULL) {
3383 if (ml->ifindex == dev->ifindex) {
3384 packet_dev_mc(dev, ml, -1);
3392 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3394 struct packet_sock *po = pkt_sk(sk);
3395 struct packet_mclist *ml, *i;
3396 struct net_device *dev;
3402 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3407 if (mreq->mr_alen > dev->addr_len)
3411 i = kmalloc(sizeof(*i), GFP_KERNEL);
3416 for (ml = po->mclist; ml; ml = ml->next) {
3417 if (ml->ifindex == mreq->mr_ifindex &&
3418 ml->type == mreq->mr_type &&
3419 ml->alen == mreq->mr_alen &&
3420 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3422 /* Free the new element ... */
3428 i->type = mreq->mr_type;
3429 i->ifindex = mreq->mr_ifindex;
3430 i->alen = mreq->mr_alen;
3431 memcpy(i->addr, mreq->mr_address, i->alen);
3433 i->next = po->mclist;
3435 err = packet_dev_mc(dev, i, 1);
3437 po->mclist = i->next;
3446 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3448 struct packet_mclist *ml, **mlp;
3452 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3453 if (ml->ifindex == mreq->mr_ifindex &&
3454 ml->type == mreq->mr_type &&
3455 ml->alen == mreq->mr_alen &&
3456 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3457 if (--ml->count == 0) {
3458 struct net_device *dev;
3460 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3462 packet_dev_mc(dev, ml, -1);
3472 static void packet_flush_mclist(struct sock *sk)
3474 struct packet_sock *po = pkt_sk(sk);
3475 struct packet_mclist *ml;
3481 while ((ml = po->mclist) != NULL) {
3482 struct net_device *dev;
3484 po->mclist = ml->next;
3485 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3487 packet_dev_mc(dev, ml, -1);
3494 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3496 struct sock *sk = sock->sk;
3497 struct packet_sock *po = pkt_sk(sk);
3500 if (level != SOL_PACKET)
3501 return -ENOPROTOOPT;
3504 case PACKET_ADD_MEMBERSHIP:
3505 case PACKET_DROP_MEMBERSHIP:
3507 struct packet_mreq_max mreq;
3509 memset(&mreq, 0, sizeof(mreq));
3510 if (len < sizeof(struct packet_mreq))
3512 if (len > sizeof(mreq))
3514 if (copy_from_user(&mreq, optval, len))
3516 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3518 if (optname == PACKET_ADD_MEMBERSHIP)
3519 ret = packet_mc_add(sk, &mreq);
3521 ret = packet_mc_drop(sk, &mreq);
3525 case PACKET_RX_RING:
3526 case PACKET_TX_RING:
3528 union tpacket_req_u req_u;
3531 switch (po->tp_version) {
3534 len = sizeof(req_u.req);
3538 len = sizeof(req_u.req3);
3543 if (pkt_sk(sk)->has_vnet_hdr)
3545 if (copy_from_user(&req_u.req, optval, len))
3547 return packet_set_ring(sk, &req_u, 0,
3548 optname == PACKET_TX_RING);
3550 case PACKET_COPY_THRESH:
3554 if (optlen != sizeof(val))
3556 if (copy_from_user(&val, optval, sizeof(val)))
3559 pkt_sk(sk)->copy_thresh = val;
3562 case PACKET_VERSION:
3566 if (optlen != sizeof(val))
3568 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3570 if (copy_from_user(&val, optval, sizeof(val)))
3576 po->tp_version = val;
3582 case PACKET_RESERVE:
3586 if (optlen != sizeof(val))
3588 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3590 if (copy_from_user(&val, optval, sizeof(val)))
3592 po->tp_reserve = val;
3599 if (optlen != sizeof(val))
3601 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3603 if (copy_from_user(&val, optval, sizeof(val)))
3605 po->tp_loss = !!val;
3608 case PACKET_AUXDATA:
3612 if (optlen < sizeof(val))
3614 if (copy_from_user(&val, optval, sizeof(val)))
3617 po->auxdata = !!val;
3620 case PACKET_ORIGDEV:
3624 if (optlen < sizeof(val))
3626 if (copy_from_user(&val, optval, sizeof(val)))
3629 po->origdev = !!val;
3632 case PACKET_VNET_HDR:
3636 if (sock->type != SOCK_RAW)
3638 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3640 if (optlen < sizeof(val))
3642 if (copy_from_user(&val, optval, sizeof(val)))
3645 po->has_vnet_hdr = !!val;
3648 case PACKET_TIMESTAMP:
3652 if (optlen != sizeof(val))
3654 if (copy_from_user(&val, optval, sizeof(val)))
3657 po->tp_tstamp = val;
3664 if (optlen != sizeof(val))
3666 if (copy_from_user(&val, optval, sizeof(val)))
3669 return fanout_add(sk, val & 0xffff, val >> 16);
3671 case PACKET_FANOUT_DATA:
3676 return fanout_set_data(po, optval, optlen);
3678 case PACKET_TX_HAS_OFF:
3682 if (optlen != sizeof(val))
3684 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3686 if (copy_from_user(&val, optval, sizeof(val)))
3688 po->tp_tx_has_off = !!val;
3691 case PACKET_QDISC_BYPASS:
3695 if (optlen != sizeof(val))
3697 if (copy_from_user(&val, optval, sizeof(val)))
3700 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3704 return -ENOPROTOOPT;
3708 static int packet_getsockopt(struct socket *sock, int level, int optname,
3709 char __user *optval, int __user *optlen)
3712 int val, lv = sizeof(val);
3713 struct sock *sk = sock->sk;
3714 struct packet_sock *po = pkt_sk(sk);
3716 union tpacket_stats_u st;
3717 struct tpacket_rollover_stats rstats;
3719 if (level != SOL_PACKET)
3720 return -ENOPROTOOPT;
3722 if (get_user(len, optlen))
3729 case PACKET_STATISTICS:
3730 spin_lock_bh(&sk->sk_receive_queue.lock);
3731 memcpy(&st, &po->stats, sizeof(st));
3732 memset(&po->stats, 0, sizeof(po->stats));
3733 spin_unlock_bh(&sk->sk_receive_queue.lock);
3735 if (po->tp_version == TPACKET_V3) {
3736 lv = sizeof(struct tpacket_stats_v3);
3737 st.stats3.tp_packets += st.stats3.tp_drops;
3740 lv = sizeof(struct tpacket_stats);
3741 st.stats1.tp_packets += st.stats1.tp_drops;
3746 case PACKET_AUXDATA:
3749 case PACKET_ORIGDEV:
3752 case PACKET_VNET_HDR:
3753 val = po->has_vnet_hdr;
3755 case PACKET_VERSION:
3756 val = po->tp_version;
3759 if (len > sizeof(int))
3761 if (copy_from_user(&val, optval, len))
3765 val = sizeof(struct tpacket_hdr);
3768 val = sizeof(struct tpacket2_hdr);
3771 val = sizeof(struct tpacket3_hdr);
3777 case PACKET_RESERVE:
3778 val = po->tp_reserve;
3783 case PACKET_TIMESTAMP:
3784 val = po->tp_tstamp;
3788 ((u32)po->fanout->id |
3789 ((u32)po->fanout->type << 16) |
3790 ((u32)po->fanout->flags << 24)) :
3793 case PACKET_ROLLOVER_STATS:
3796 rstats.tp_all = atomic_long_read(&po->rollover->num);
3797 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3798 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3800 lv = sizeof(rstats);
3802 case PACKET_TX_HAS_OFF:
3803 val = po->tp_tx_has_off;
3805 case PACKET_QDISC_BYPASS:
3806 val = packet_use_direct_xmit(po);
3809 return -ENOPROTOOPT;
3814 if (put_user(len, optlen))
3816 if (copy_to_user(optval, data, len))
3822 static int packet_notifier(struct notifier_block *this,
3823 unsigned long msg, void *ptr)
3826 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3827 struct net *net = dev_net(dev);
3830 sk_for_each_rcu(sk, &net->packet.sklist) {
3831 struct packet_sock *po = pkt_sk(sk);
3834 case NETDEV_UNREGISTER:
3836 packet_dev_mclist_delete(dev, &po->mclist);
3840 if (dev->ifindex == po->ifindex) {
3841 spin_lock(&po->bind_lock);
3843 __unregister_prot_hook(sk, false);
3844 sk->sk_err = ENETDOWN;
3845 if (!sock_flag(sk, SOCK_DEAD))
3846 sk->sk_error_report(sk);
3848 if (msg == NETDEV_UNREGISTER) {
3849 packet_cached_dev_reset(po);
3851 if (po->prot_hook.dev)
3852 dev_put(po->prot_hook.dev);
3853 po->prot_hook.dev = NULL;
3855 spin_unlock(&po->bind_lock);
3859 if (dev->ifindex == po->ifindex) {
3860 spin_lock(&po->bind_lock);
3862 register_prot_hook(sk);
3863 spin_unlock(&po->bind_lock);
3873 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3876 struct sock *sk = sock->sk;
3881 int amount = sk_wmem_alloc_get(sk);
3883 return put_user(amount, (int __user *)arg);
3887 struct sk_buff *skb;
3890 spin_lock_bh(&sk->sk_receive_queue.lock);
3891 skb = skb_peek(&sk->sk_receive_queue);
3894 spin_unlock_bh(&sk->sk_receive_queue.lock);
3895 return put_user(amount, (int __user *)arg);
3898 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3900 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3910 case SIOCGIFBRDADDR:
3911 case SIOCSIFBRDADDR:
3912 case SIOCGIFNETMASK:
3913 case SIOCSIFNETMASK:
3914 case SIOCGIFDSTADDR:
3915 case SIOCSIFDSTADDR:
3917 return inet_dgram_ops.ioctl(sock, cmd, arg);
3921 return -ENOIOCTLCMD;
3926 static unsigned int packet_poll(struct file *file, struct socket *sock,
3929 struct sock *sk = sock->sk;
3930 struct packet_sock *po = pkt_sk(sk);
3931 unsigned int mask = datagram_poll(file, sock, wait);
3933 spin_lock_bh(&sk->sk_receive_queue.lock);
3934 if (po->rx_ring.pg_vec) {
3935 if (!packet_previous_rx_frame(po, &po->rx_ring,
3937 mask |= POLLIN | POLLRDNORM;
3939 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
3941 spin_unlock_bh(&sk->sk_receive_queue.lock);
3942 spin_lock_bh(&sk->sk_write_queue.lock);
3943 if (po->tx_ring.pg_vec) {
3944 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3945 mask |= POLLOUT | POLLWRNORM;
3947 spin_unlock_bh(&sk->sk_write_queue.lock);
3952 /* Dirty? Well, I still did not learn better way to account
3956 static void packet_mm_open(struct vm_area_struct *vma)
3958 struct file *file = vma->vm_file;
3959 struct socket *sock = file->private_data;
3960 struct sock *sk = sock->sk;
3963 atomic_inc(&pkt_sk(sk)->mapped);
3966 static void packet_mm_close(struct vm_area_struct *vma)
3968 struct file *file = vma->vm_file;
3969 struct socket *sock = file->private_data;
3970 struct sock *sk = sock->sk;
3973 atomic_dec(&pkt_sk(sk)->mapped);
3976 static const struct vm_operations_struct packet_mmap_ops = {
3977 .open = packet_mm_open,
3978 .close = packet_mm_close,
3981 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3986 for (i = 0; i < len; i++) {
3987 if (likely(pg_vec[i].buffer)) {
3988 if (is_vmalloc_addr(pg_vec[i].buffer))
3989 vfree(pg_vec[i].buffer);
3991 free_pages((unsigned long)pg_vec[i].buffer,
3993 pg_vec[i].buffer = NULL;
3999 static char *alloc_one_pg_vec_page(unsigned long order)
4002 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4003 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4005 buffer = (char *) __get_free_pages(gfp_flags, order);
4009 /* __get_free_pages failed, fall back to vmalloc */
4010 buffer = vzalloc((1 << order) * PAGE_SIZE);
4014 /* vmalloc failed, lets dig into swap here */
4015 gfp_flags &= ~__GFP_NORETRY;
4016 buffer = (char *) __get_free_pages(gfp_flags, order);
4020 /* complete and utter failure */
4024 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4026 unsigned int block_nr = req->tp_block_nr;
4030 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4031 if (unlikely(!pg_vec))
4034 for (i = 0; i < block_nr; i++) {
4035 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4036 if (unlikely(!pg_vec[i].buffer))
4037 goto out_free_pgvec;
4044 free_pg_vec(pg_vec, order, block_nr);
4049 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4050 int closing, int tx_ring)
4052 struct pgv *pg_vec = NULL;
4053 struct packet_sock *po = pkt_sk(sk);
4054 int was_running, order = 0;
4055 struct packet_ring_buffer *rb;
4056 struct sk_buff_head *rb_queue;
4059 /* Added to avoid minimal code churn */
4060 struct tpacket_req *req = &req_u->req;
4062 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4063 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4064 WARN(1, "Tx-ring is not supported.\n");
4068 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4069 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4073 if (atomic_read(&po->mapped))
4075 if (packet_read_pending(rb))
4079 if (req->tp_block_nr) {
4080 /* Sanity tests and some calculations */
4082 if (unlikely(rb->pg_vec))
4085 switch (po->tp_version) {
4087 po->tp_hdrlen = TPACKET_HDRLEN;
4090 po->tp_hdrlen = TPACKET2_HDRLEN;
4093 po->tp_hdrlen = TPACKET3_HDRLEN;
4098 if (unlikely((int)req->tp_block_size <= 0))
4100 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
4102 if (po->tp_version >= TPACKET_V3 &&
4103 (int)(req->tp_block_size -
4104 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4106 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4109 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4112 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
4113 if (unlikely(rb->frames_per_block <= 0))
4115 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4120 order = get_order(req->tp_block_size);
4121 pg_vec = alloc_pg_vec(req, order);
4122 if (unlikely(!pg_vec))
4124 switch (po->tp_version) {
4126 /* Transmit path is not supported. We checked
4127 * it above but just being paranoid
4130 init_prb_bdqc(po, rb, pg_vec, req_u);
4139 if (unlikely(req->tp_frame_nr))
4145 /* Detach socket from network */
4146 spin_lock(&po->bind_lock);
4147 was_running = po->running;
4151 __unregister_prot_hook(sk, false);
4153 spin_unlock(&po->bind_lock);
4158 mutex_lock(&po->pg_vec_lock);
4159 if (closing || atomic_read(&po->mapped) == 0) {
4161 spin_lock_bh(&rb_queue->lock);
4162 swap(rb->pg_vec, pg_vec);
4163 rb->frame_max = (req->tp_frame_nr - 1);
4165 rb->frame_size = req->tp_frame_size;
4166 spin_unlock_bh(&rb_queue->lock);
4168 swap(rb->pg_vec_order, order);
4169 swap(rb->pg_vec_len, req->tp_block_nr);
4171 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4172 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4173 tpacket_rcv : packet_rcv;
4174 skb_queue_purge(rb_queue);
4175 if (atomic_read(&po->mapped))
4176 pr_err("packet_mmap: vma is busy: %d\n",
4177 atomic_read(&po->mapped));
4179 mutex_unlock(&po->pg_vec_lock);
4181 spin_lock(&po->bind_lock);
4184 register_prot_hook(sk);
4186 spin_unlock(&po->bind_lock);
4187 if (closing && (po->tp_version > TPACKET_V2)) {
4188 /* Because we don't support block-based V3 on tx-ring */
4190 prb_shutdown_retire_blk_timer(po, rb_queue);
4195 free_pg_vec(pg_vec, order, req->tp_block_nr);
4200 static int packet_mmap(struct file *file, struct socket *sock,
4201 struct vm_area_struct *vma)
4203 struct sock *sk = sock->sk;
4204 struct packet_sock *po = pkt_sk(sk);
4205 unsigned long size, expected_size;
4206 struct packet_ring_buffer *rb;
4207 unsigned long start;
4214 mutex_lock(&po->pg_vec_lock);
4217 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4219 expected_size += rb->pg_vec_len
4225 if (expected_size == 0)
4228 size = vma->vm_end - vma->vm_start;
4229 if (size != expected_size)
4232 start = vma->vm_start;
4233 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4234 if (rb->pg_vec == NULL)
4237 for (i = 0; i < rb->pg_vec_len; i++) {
4239 void *kaddr = rb->pg_vec[i].buffer;
4242 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4243 page = pgv_to_page(kaddr);
4244 err = vm_insert_page(vma, start, page);
4253 atomic_inc(&po->mapped);
4254 vma->vm_ops = &packet_mmap_ops;
4258 mutex_unlock(&po->pg_vec_lock);
4262 static const struct proto_ops packet_ops_spkt = {
4263 .family = PF_PACKET,
4264 .owner = THIS_MODULE,
4265 .release = packet_release,
4266 .bind = packet_bind_spkt,
4267 .connect = sock_no_connect,
4268 .socketpair = sock_no_socketpair,
4269 .accept = sock_no_accept,
4270 .getname = packet_getname_spkt,
4271 .poll = datagram_poll,
4272 .ioctl = packet_ioctl,
4273 .listen = sock_no_listen,
4274 .shutdown = sock_no_shutdown,
4275 .setsockopt = sock_no_setsockopt,
4276 .getsockopt = sock_no_getsockopt,
4277 .sendmsg = packet_sendmsg_spkt,
4278 .recvmsg = packet_recvmsg,
4279 .mmap = sock_no_mmap,
4280 .sendpage = sock_no_sendpage,
4283 static const struct proto_ops packet_ops = {
4284 .family = PF_PACKET,
4285 .owner = THIS_MODULE,
4286 .release = packet_release,
4287 .bind = packet_bind,
4288 .connect = sock_no_connect,
4289 .socketpair = sock_no_socketpair,
4290 .accept = sock_no_accept,
4291 .getname = packet_getname,
4292 .poll = packet_poll,
4293 .ioctl = packet_ioctl,
4294 .listen = sock_no_listen,
4295 .shutdown = sock_no_shutdown,
4296 .setsockopt = packet_setsockopt,
4297 .getsockopt = packet_getsockopt,
4298 .sendmsg = packet_sendmsg,
4299 .recvmsg = packet_recvmsg,
4300 .mmap = packet_mmap,
4301 .sendpage = sock_no_sendpage,
4304 static const struct net_proto_family packet_family_ops = {
4305 .family = PF_PACKET,
4306 .create = packet_create,
4307 .owner = THIS_MODULE,
4310 static struct notifier_block packet_netdev_notifier = {
4311 .notifier_call = packet_notifier,
4314 #ifdef CONFIG_PROC_FS
4316 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4319 struct net *net = seq_file_net(seq);
4322 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4325 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4327 struct net *net = seq_file_net(seq);
4328 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4331 static void packet_seq_stop(struct seq_file *seq, void *v)
4337 static int packet_seq_show(struct seq_file *seq, void *v)
4339 if (v == SEQ_START_TOKEN)
4340 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4342 struct sock *s = sk_entry(v);
4343 const struct packet_sock *po = pkt_sk(s);
4346 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4348 atomic_read(&s->sk_refcnt),
4353 atomic_read(&s->sk_rmem_alloc),
4354 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4361 static const struct seq_operations packet_seq_ops = {
4362 .start = packet_seq_start,
4363 .next = packet_seq_next,
4364 .stop = packet_seq_stop,
4365 .show = packet_seq_show,
4368 static int packet_seq_open(struct inode *inode, struct file *file)
4370 return seq_open_net(inode, file, &packet_seq_ops,
4371 sizeof(struct seq_net_private));
4374 static const struct file_operations packet_seq_fops = {
4375 .owner = THIS_MODULE,
4376 .open = packet_seq_open,
4378 .llseek = seq_lseek,
4379 .release = seq_release_net,
4384 static int __net_init packet_net_init(struct net *net)
4386 mutex_init(&net->packet.sklist_lock);
4387 INIT_HLIST_HEAD(&net->packet.sklist);
4389 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4395 static void __net_exit packet_net_exit(struct net *net)
4397 remove_proc_entry("packet", net->proc_net);
4400 static struct pernet_operations packet_net_ops = {
4401 .init = packet_net_init,
4402 .exit = packet_net_exit,
4406 static void __exit packet_exit(void)
4408 unregister_netdevice_notifier(&packet_netdev_notifier);
4409 unregister_pernet_subsys(&packet_net_ops);
4410 sock_unregister(PF_PACKET);
4411 proto_unregister(&packet_proto);
4414 static int __init packet_init(void)
4416 int rc = proto_register(&packet_proto, 0);
4421 sock_register(&packet_family_ops);
4422 register_pernet_subsys(&packet_net_ops);
4423 register_netdevice_notifier(&packet_netdev_notifier);
4428 module_init(packet_init);
4429 module_exit(packet_exit);
4430 MODULE_LICENSE("GPL");
4431 MODULE_ALIAS_NETPROTO(PF_PACKET);