2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * PACKET - implements raw packet sockets.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
55 #include <linux/types.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
79 #include <asm/cacheflush.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/percpu.h>
93 #include <net/inet_common.h>
95 #include <linux/bpf.h>
101 - if device has no dev->hard_header routine, it adds and removes ll header
102 inside itself. In this case ll header is invisible outside of device,
103 but higher levels still should reserve dev->hard_header_len.
104 Some devices are enough clever to reallocate skb, when header
105 will not fit to reserved space (tunnel), another ones are silly
107 - packet socket receives packets with pulled ll header,
108 so that SOCK_RAW should push it back.
113 Incoming, dev->hard_header!=NULL
114 mac_header -> ll header
117 Outgoing, dev->hard_header!=NULL
118 mac_header -> ll header
121 Incoming, dev->hard_header==NULL
122 mac_header -> UNKNOWN position. It is very likely, that it points to ll
123 header. PPP makes it, that is wrong, because introduce
124 assymetry between rx and tx paths.
127 Outgoing, dev->hard_header==NULL
128 mac_header -> data. ll header is still not built!
132 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
138 dev->hard_header != NULL
139 mac_header -> ll header
142 dev->hard_header == NULL (ll header is added by device, we cannot control it)
146 We should set nh.raw on output to correct posistion,
147 packet classifier depends on it.
150 /* Private packet socket structures. */
152 /* identical to struct packet_mreq except it has
153 * a longer address field.
155 struct packet_mreq_max {
157 unsigned short mr_type;
158 unsigned short mr_alen;
159 unsigned char mr_address[MAX_ADDR_LEN];
163 struct tpacket_hdr *h1;
164 struct tpacket2_hdr *h2;
165 struct tpacket3_hdr *h3;
169 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
170 int closing, int tx_ring);
172 #define V3_ALIGNMENT (8)
174 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
176 #define BLK_PLUS_PRIV(sz_of_priv) \
177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
179 #define PGV_FROM_VMALLOC 1
181 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
182 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
183 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
184 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
185 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
186 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
187 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
190 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
192 struct packet_type *pt, struct net_device *orig_dev);
194 static void *packet_previous_frame(struct packet_sock *po,
195 struct packet_ring_buffer *rb,
197 static void packet_increment_head(struct packet_ring_buffer *buff);
198 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
199 struct tpacket_block_desc *);
200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
201 struct packet_sock *);
202 static void prb_retire_current_block(struct tpacket_kbdq_core *,
203 struct packet_sock *, unsigned int status);
204 static int prb_queue_frozen(struct tpacket_kbdq_core *);
205 static void prb_open_block(struct tpacket_kbdq_core *,
206 struct tpacket_block_desc *);
207 static void prb_retire_rx_blk_timer_expired(unsigned long);
208 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
209 static void prb_init_blk_timer(struct packet_sock *,
210 struct tpacket_kbdq_core *,
211 void (*func) (unsigned long));
212 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
213 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
214 struct tpacket3_hdr *);
215 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
216 struct tpacket3_hdr *);
217 static void packet_flush_mclist(struct sock *sk);
219 struct packet_skb_cb {
221 struct sockaddr_pkt pkt;
223 /* Trick: alias skb original length with
224 * ll.sll_family and ll.protocol in order
227 unsigned int origlen;
228 struct sockaddr_ll ll;
233 #define vio_le() virtio_legacy_is_little_endian()
235 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
237 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
238 #define GET_PBLOCK_DESC(x, bid) \
239 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
240 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
241 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
242 #define GET_NEXT_PRB_BLK_NUM(x) \
243 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
244 ((x)->kactive_blk_num+1) : 0)
246 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
247 static void __fanout_link(struct sock *sk, struct packet_sock *po);
249 static int packet_direct_xmit(struct sk_buff *skb)
251 struct net_device *dev = skb->dev;
252 netdev_features_t features;
253 struct netdev_queue *txq;
254 int ret = NETDEV_TX_BUSY;
256 if (unlikely(!netif_running(dev) ||
257 !netif_carrier_ok(dev)))
260 features = netif_skb_features(skb);
261 if (skb_needs_linearize(skb, features) &&
262 __skb_linearize(skb))
265 txq = skb_get_tx_queue(dev, skb);
269 HARD_TX_LOCK(dev, txq, smp_processor_id());
270 if (!netif_xmit_frozen_or_drv_stopped(txq))
271 ret = netdev_start_xmit(skb, dev, txq, false);
272 HARD_TX_UNLOCK(dev, txq);
276 if (!dev_xmit_complete(ret))
281 atomic_long_inc(&dev->tx_dropped);
283 return NET_XMIT_DROP;
286 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
288 struct net_device *dev;
291 dev = rcu_dereference(po->cached_dev);
299 static void packet_cached_dev_assign(struct packet_sock *po,
300 struct net_device *dev)
302 rcu_assign_pointer(po->cached_dev, dev);
305 static void packet_cached_dev_reset(struct packet_sock *po)
307 RCU_INIT_POINTER(po->cached_dev, NULL);
310 static bool packet_use_direct_xmit(const struct packet_sock *po)
312 return po->xmit == packet_direct_xmit;
315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
317 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
322 const struct net_device_ops *ops = dev->netdev_ops;
325 if (ops->ndo_select_queue) {
326 queue_index = ops->ndo_select_queue(dev, skb, NULL,
327 __packet_pick_tx_queue);
328 queue_index = netdev_cap_txqueue(dev, queue_index);
330 queue_index = __packet_pick_tx_queue(dev, skb);
333 skb_set_queue_mapping(skb, queue_index);
336 /* register_prot_hook must be invoked with the po->bind_lock held,
337 * or from a context in which asynchronous accesses to the packet
338 * socket is not possible (packet_create()).
340 static void register_prot_hook(struct sock *sk)
342 struct packet_sock *po = pkt_sk(sk);
346 __fanout_link(sk, po);
348 dev_add_pack(&po->prot_hook);
355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
356 * held. If the sync parameter is true, we will temporarily drop
357 * the po->bind_lock and do a synchronize_net to make sure no
358 * asynchronous packet processing paths still refer to the elements
359 * of po->prot_hook. If the sync parameter is false, it is the
360 * callers responsibility to take care of this.
362 static void __unregister_prot_hook(struct sock *sk, bool sync)
364 struct packet_sock *po = pkt_sk(sk);
369 __fanout_unlink(sk, po);
371 __dev_remove_pack(&po->prot_hook);
376 spin_unlock(&po->bind_lock);
378 spin_lock(&po->bind_lock);
382 static void unregister_prot_hook(struct sock *sk, bool sync)
384 struct packet_sock *po = pkt_sk(sk);
387 __unregister_prot_hook(sk, sync);
390 static inline struct page * __pure pgv_to_page(void *addr)
392 if (is_vmalloc_addr(addr))
393 return vmalloc_to_page(addr);
394 return virt_to_page(addr);
397 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
399 union tpacket_uhdr h;
402 switch (po->tp_version) {
404 h.h1->tp_status = status;
405 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
408 h.h2->tp_status = status;
409 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
413 WARN(1, "TPACKET version not supported.\n");
420 static int __packet_get_status(struct packet_sock *po, void *frame)
422 union tpacket_uhdr h;
427 switch (po->tp_version) {
429 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
430 return h.h1->tp_status;
432 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
433 return h.h2->tp_status;
436 WARN(1, "TPACKET version not supported.\n");
442 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
445 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
448 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
449 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
450 return TP_STATUS_TS_RAW_HARDWARE;
452 if (ktime_to_timespec_cond(skb->tstamp, ts))
453 return TP_STATUS_TS_SOFTWARE;
458 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
461 union tpacket_uhdr h;
465 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
469 switch (po->tp_version) {
471 h.h1->tp_sec = ts.tv_sec;
472 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
475 h.h2->tp_sec = ts.tv_sec;
476 h.h2->tp_nsec = ts.tv_nsec;
480 WARN(1, "TPACKET version not supported.\n");
484 /* one flush is safe, as both fields always lie on the same cacheline */
485 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
491 static void *packet_lookup_frame(struct packet_sock *po,
492 struct packet_ring_buffer *rb,
493 unsigned int position,
496 unsigned int pg_vec_pos, frame_offset;
497 union tpacket_uhdr h;
499 pg_vec_pos = position / rb->frames_per_block;
500 frame_offset = position % rb->frames_per_block;
502 h.raw = rb->pg_vec[pg_vec_pos].buffer +
503 (frame_offset * rb->frame_size);
505 if (status != __packet_get_status(po, h.raw))
511 static void *packet_current_frame(struct packet_sock *po,
512 struct packet_ring_buffer *rb,
515 return packet_lookup_frame(po, rb, rb->head, status);
518 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
520 del_timer_sync(&pkc->retire_blk_timer);
523 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
524 struct sk_buff_head *rb_queue)
526 struct tpacket_kbdq_core *pkc;
528 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
530 spin_lock_bh(&rb_queue->lock);
531 pkc->delete_blk_timer = 1;
532 spin_unlock_bh(&rb_queue->lock);
534 prb_del_retire_blk_timer(pkc);
537 static void prb_init_blk_timer(struct packet_sock *po,
538 struct tpacket_kbdq_core *pkc,
539 void (*func) (unsigned long))
541 init_timer(&pkc->retire_blk_timer);
542 pkc->retire_blk_timer.data = (long)po;
543 pkc->retire_blk_timer.function = func;
544 pkc->retire_blk_timer.expires = jiffies;
547 static void prb_setup_retire_blk_timer(struct packet_sock *po)
549 struct tpacket_kbdq_core *pkc;
551 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
552 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
555 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
556 int blk_size_in_bytes)
558 struct net_device *dev;
559 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
560 struct ethtool_cmd ecmd;
565 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
566 if (unlikely(!dev)) {
568 return DEFAULT_PRB_RETIRE_TOV;
570 err = __ethtool_get_settings(dev, &ecmd);
571 speed = ethtool_cmd_speed(&ecmd);
575 * If the link speed is so slow you don't really
576 * need to worry about perf anyways
578 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
579 return DEFAULT_PRB_RETIRE_TOV;
586 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
598 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
599 union tpacket_req_u *req_u)
601 p1->feature_req_word = req_u->req3.tp_feature_req_word;
604 static void init_prb_bdqc(struct packet_sock *po,
605 struct packet_ring_buffer *rb,
607 union tpacket_req_u *req_u)
609 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
610 struct tpacket_block_desc *pbd;
612 memset(p1, 0x0, sizeof(*p1));
614 p1->knxt_seq_num = 1;
616 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
617 p1->pkblk_start = pg_vec[0].buffer;
618 p1->kblk_size = req_u->req3.tp_block_size;
619 p1->knum_blocks = req_u->req3.tp_block_nr;
620 p1->hdrlen = po->tp_hdrlen;
621 p1->version = po->tp_version;
622 p1->last_kactive_blk_num = 0;
623 po->stats.stats3.tp_freeze_q_cnt = 0;
624 if (req_u->req3.tp_retire_blk_tov)
625 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
627 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
628 req_u->req3.tp_block_size);
629 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
630 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
632 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
633 prb_init_ft_ops(p1, req_u);
634 prb_setup_retire_blk_timer(po);
635 prb_open_block(p1, pbd);
638 /* Do NOT update the last_blk_num first.
639 * Assumes sk_buff_head lock is held.
641 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
643 mod_timer(&pkc->retire_blk_timer,
644 jiffies + pkc->tov_in_jiffies);
645 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
650 * 1) We refresh the timer only when we open a block.
651 * By doing this we don't waste cycles refreshing the timer
652 * on packet-by-packet basis.
654 * With a 1MB block-size, on a 1Gbps line, it will take
655 * i) ~8 ms to fill a block + ii) memcpy etc.
656 * In this cut we are not accounting for the memcpy time.
658 * So, if the user sets the 'tmo' to 10ms then the timer
659 * will never fire while the block is still getting filled
660 * (which is what we want). However, the user could choose
661 * to close a block early and that's fine.
663 * But when the timer does fire, we check whether or not to refresh it.
664 * Since the tmo granularity is in msecs, it is not too expensive
665 * to refresh the timer, lets say every '8' msecs.
666 * Either the user can set the 'tmo' or we can derive it based on
667 * a) line-speed and b) block-size.
668 * prb_calc_retire_blk_tmo() calculates the tmo.
671 static void prb_retire_rx_blk_timer_expired(unsigned long data)
673 struct packet_sock *po = (struct packet_sock *)data;
674 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
676 struct tpacket_block_desc *pbd;
678 spin_lock(&po->sk.sk_receive_queue.lock);
680 frozen = prb_queue_frozen(pkc);
681 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
683 if (unlikely(pkc->delete_blk_timer))
686 /* We only need to plug the race when the block is partially filled.
688 * lock(); increment BLOCK_NUM_PKTS; unlock()
689 * copy_bits() is in progress ...
690 * timer fires on other cpu:
691 * we can't retire the current block because copy_bits
695 if (BLOCK_NUM_PKTS(pbd)) {
696 while (atomic_read(&pkc->blk_fill_in_prog)) {
697 /* Waiting for skb_copy_bits to finish... */
702 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
704 if (!BLOCK_NUM_PKTS(pbd)) {
705 /* An empty block. Just refresh the timer. */
708 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
709 if (!prb_dispatch_next_block(pkc, po))
714 /* Case 1. Queue was frozen because user-space was
717 if (prb_curr_blk_in_use(pkc, pbd)) {
719 * Ok, user-space is still behind.
720 * So just refresh the timer.
724 /* Case 2. queue was frozen,user-space caught up,
725 * now the link went idle && the timer fired.
726 * We don't have a block to close.So we open this
727 * block and restart the timer.
728 * opening a block thaws the queue,restarts timer
729 * Thawing/timer-refresh is a side effect.
731 prb_open_block(pkc, pbd);
738 _prb_refresh_rx_retire_blk_timer(pkc);
741 spin_unlock(&po->sk.sk_receive_queue.lock);
744 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
745 struct tpacket_block_desc *pbd1, __u32 status)
747 /* Flush everything minus the block header */
749 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
754 /* Skip the block header(we know header WILL fit in 4K) */
757 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
758 for (; start < end; start += PAGE_SIZE)
759 flush_dcache_page(pgv_to_page(start));
764 /* Now update the block status. */
766 BLOCK_STATUS(pbd1) = status;
768 /* Flush the block header */
770 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
772 flush_dcache_page(pgv_to_page(start));
782 * 2) Increment active_blk_num
784 * Note:We DONT refresh the timer on purpose.
785 * Because almost always the next block will be opened.
787 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
788 struct tpacket_block_desc *pbd1,
789 struct packet_sock *po, unsigned int stat)
791 __u32 status = TP_STATUS_USER | stat;
793 struct tpacket3_hdr *last_pkt;
794 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
795 struct sock *sk = &po->sk;
797 if (po->stats.stats3.tp_drops)
798 status |= TP_STATUS_LOSING;
800 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
801 last_pkt->tp_next_offset = 0;
803 /* Get the ts of the last pkt */
804 if (BLOCK_NUM_PKTS(pbd1)) {
805 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
806 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
808 /* Ok, we tmo'd - so get the current time.
810 * It shouldn't really happen as we don't close empty
811 * blocks. See prb_retire_rx_blk_timer_expired().
815 h1->ts_last_pkt.ts_sec = ts.tv_sec;
816 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
821 /* Flush the block */
822 prb_flush_block(pkc1, pbd1, status);
824 sk->sk_data_ready(sk);
826 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
829 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
831 pkc->reset_pending_on_curr_blk = 0;
835 * Side effect of opening a block:
837 * 1) prb_queue is thawed.
838 * 2) retire_blk_timer is refreshed.
841 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
842 struct tpacket_block_desc *pbd1)
845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
849 /* We could have just memset this but we will lose the
850 * flexibility of making the priv area sticky
853 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
854 BLOCK_NUM_PKTS(pbd1) = 0;
855 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
859 h1->ts_first_pkt.ts_sec = ts.tv_sec;
860 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
862 pkc1->pkblk_start = (char *)pbd1;
863 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
865 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
866 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
868 pbd1->version = pkc1->version;
869 pkc1->prev = pkc1->nxt_offset;
870 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
872 prb_thaw_queue(pkc1);
873 _prb_refresh_rx_retire_blk_timer(pkc1);
879 * Queue freeze logic:
880 * 1) Assume tp_block_nr = 8 blocks.
881 * 2) At time 't0', user opens Rx ring.
882 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
883 * 4) user-space is either sleeping or processing block '0'.
884 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
885 * it will close block-7,loop around and try to fill block '0'.
887 * __packet_lookup_frame_in_block
888 * prb_retire_current_block()
889 * prb_dispatch_next_block()
890 * |->(BLOCK_STATUS == USER) evaluates to true
891 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
892 * 6) Now there are two cases:
893 * 6.1) Link goes idle right after the queue is frozen.
894 * But remember, the last open_block() refreshed the timer.
895 * When this timer expires,it will refresh itself so that we can
896 * re-open block-0 in near future.
897 * 6.2) Link is busy and keeps on receiving packets. This is a simple
898 * case and __packet_lookup_frame_in_block will check if block-0
899 * is free and can now be re-used.
901 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
902 struct packet_sock *po)
904 pkc->reset_pending_on_curr_blk = 1;
905 po->stats.stats3.tp_freeze_q_cnt++;
908 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
911 * If the next block is free then we will dispatch it
912 * and return a good offset.
913 * Else, we will freeze the queue.
914 * So, caller must check the return value.
916 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
917 struct packet_sock *po)
919 struct tpacket_block_desc *pbd;
923 /* 1. Get current block num */
924 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
926 /* 2. If this block is currently in_use then freeze the queue */
927 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
928 prb_freeze_queue(pkc, po);
934 * open this block and return the offset where the first packet
935 * needs to get stored.
937 prb_open_block(pkc, pbd);
938 return (void *)pkc->nxt_offset;
941 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
942 struct packet_sock *po, unsigned int status)
944 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
946 /* retire/close the current block */
947 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
949 * Plug the case where copy_bits() is in progress on
950 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
951 * have space to copy the pkt in the current block and
952 * called prb_retire_current_block()
954 * We don't need to worry about the TMO case because
955 * the timer-handler already handled this case.
957 if (!(status & TP_STATUS_BLK_TMO)) {
958 while (atomic_read(&pkc->blk_fill_in_prog)) {
959 /* Waiting for skb_copy_bits to finish... */
963 prb_close_block(pkc, pbd, po, status);
968 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
969 struct tpacket_block_desc *pbd)
971 return TP_STATUS_USER & BLOCK_STATUS(pbd);
974 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
976 return pkc->reset_pending_on_curr_blk;
979 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
981 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
982 atomic_dec(&pkc->blk_fill_in_prog);
985 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
986 struct tpacket3_hdr *ppd)
988 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
991 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
992 struct tpacket3_hdr *ppd)
994 ppd->hv1.tp_rxhash = 0;
997 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
998 struct tpacket3_hdr *ppd)
1000 if (skb_vlan_tag_present(pkc->skb)) {
1001 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1002 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1003 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1005 ppd->hv1.tp_vlan_tci = 0;
1006 ppd->hv1.tp_vlan_tpid = 0;
1007 ppd->tp_status = TP_STATUS_AVAILABLE;
1011 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1012 struct tpacket3_hdr *ppd)
1014 ppd->hv1.tp_padding = 0;
1015 prb_fill_vlan_info(pkc, ppd);
1017 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1018 prb_fill_rxhash(pkc, ppd);
1020 prb_clear_rxhash(pkc, ppd);
1023 static void prb_fill_curr_block(char *curr,
1024 struct tpacket_kbdq_core *pkc,
1025 struct tpacket_block_desc *pbd,
1028 struct tpacket3_hdr *ppd;
1030 ppd = (struct tpacket3_hdr *)curr;
1031 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1033 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1034 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1035 BLOCK_NUM_PKTS(pbd) += 1;
1036 atomic_inc(&pkc->blk_fill_in_prog);
1037 prb_run_all_ft_ops(pkc, ppd);
1040 /* Assumes caller has the sk->rx_queue.lock */
1041 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1042 struct sk_buff *skb,
1047 struct tpacket_kbdq_core *pkc;
1048 struct tpacket_block_desc *pbd;
1051 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1052 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1054 /* Queue is frozen when user space is lagging behind */
1055 if (prb_queue_frozen(pkc)) {
1057 * Check if that last block which caused the queue to freeze,
1058 * is still in_use by user-space.
1060 if (prb_curr_blk_in_use(pkc, pbd)) {
1061 /* Can't record this packet */
1065 * Ok, the block was released by user-space.
1066 * Now let's open that block.
1067 * opening a block also thaws the queue.
1068 * Thawing is a side effect.
1070 prb_open_block(pkc, pbd);
1075 curr = pkc->nxt_offset;
1077 end = (char *)pbd + pkc->kblk_size;
1079 /* first try the current block */
1080 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1081 prb_fill_curr_block(curr, pkc, pbd, len);
1082 return (void *)curr;
1085 /* Ok, close the current block */
1086 prb_retire_current_block(pkc, po, 0);
1088 /* Now, try to dispatch the next block */
1089 curr = (char *)prb_dispatch_next_block(pkc, po);
1091 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1092 prb_fill_curr_block(curr, pkc, pbd, len);
1093 return (void *)curr;
1097 * No free blocks are available.user_space hasn't caught up yet.
1098 * Queue was just frozen and now this packet will get dropped.
1103 static void *packet_current_rx_frame(struct packet_sock *po,
1104 struct sk_buff *skb,
1105 int status, unsigned int len)
1108 switch (po->tp_version) {
1111 curr = packet_lookup_frame(po, &po->rx_ring,
1112 po->rx_ring.head, status);
1115 return __packet_lookup_frame_in_block(po, skb, status, len);
1117 WARN(1, "TPACKET version not supported\n");
1123 static void *prb_lookup_block(struct packet_sock *po,
1124 struct packet_ring_buffer *rb,
1128 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1129 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1131 if (status != BLOCK_STATUS(pbd))
1136 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1139 if (rb->prb_bdqc.kactive_blk_num)
1140 prev = rb->prb_bdqc.kactive_blk_num-1;
1142 prev = rb->prb_bdqc.knum_blocks-1;
1146 /* Assumes caller has held the rx_queue.lock */
1147 static void *__prb_previous_block(struct packet_sock *po,
1148 struct packet_ring_buffer *rb,
1151 unsigned int previous = prb_previous_blk_num(rb);
1152 return prb_lookup_block(po, rb, previous, status);
1155 static void *packet_previous_rx_frame(struct packet_sock *po,
1156 struct packet_ring_buffer *rb,
1159 if (po->tp_version <= TPACKET_V2)
1160 return packet_previous_frame(po, rb, status);
1162 return __prb_previous_block(po, rb, status);
1165 static void packet_increment_rx_head(struct packet_sock *po,
1166 struct packet_ring_buffer *rb)
1168 switch (po->tp_version) {
1171 return packet_increment_head(rb);
1174 WARN(1, "TPACKET version not supported.\n");
1180 static void *packet_previous_frame(struct packet_sock *po,
1181 struct packet_ring_buffer *rb,
1184 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1185 return packet_lookup_frame(po, rb, previous, status);
1188 static void packet_increment_head(struct packet_ring_buffer *buff)
1190 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1193 static void packet_inc_pending(struct packet_ring_buffer *rb)
1195 this_cpu_inc(*rb->pending_refcnt);
1198 static void packet_dec_pending(struct packet_ring_buffer *rb)
1200 this_cpu_dec(*rb->pending_refcnt);
1203 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1205 unsigned int refcnt = 0;
1208 /* We don't use pending refcount in rx_ring. */
1209 if (rb->pending_refcnt == NULL)
1212 for_each_possible_cpu(cpu)
1213 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1218 static int packet_alloc_pending(struct packet_sock *po)
1220 po->rx_ring.pending_refcnt = NULL;
1222 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1223 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1229 static void packet_free_pending(struct packet_sock *po)
1231 free_percpu(po->tx_ring.pending_refcnt);
1234 #define ROOM_POW_OFF 2
1235 #define ROOM_NONE 0x0
1236 #define ROOM_LOW 0x1
1237 #define ROOM_NORMAL 0x2
1239 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1243 len = po->rx_ring.frame_max + 1;
1244 idx = po->rx_ring.head;
1246 idx += len >> pow_off;
1249 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1252 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1256 len = po->rx_ring.prb_bdqc.knum_blocks;
1257 idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1259 idx += len >> pow_off;
1262 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1265 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1267 struct sock *sk = &po->sk;
1268 int ret = ROOM_NONE;
1270 if (po->prot_hook.func != tpacket_rcv) {
1271 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1272 - (skb ? skb->truesize : 0);
1273 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1281 if (po->tp_version == TPACKET_V3) {
1282 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1284 else if (__tpacket_v3_has_room(po, 0))
1287 if (__tpacket_has_room(po, ROOM_POW_OFF))
1289 else if (__tpacket_has_room(po, 0))
1296 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1301 spin_lock_bh(&po->sk.sk_receive_queue.lock);
1302 ret = __packet_rcv_has_room(po, skb);
1303 has_room = ret == ROOM_NORMAL;
1304 if (po->pressure == has_room)
1305 po->pressure = !has_room;
1306 spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1311 static void packet_sock_destruct(struct sock *sk)
1313 skb_queue_purge(&sk->sk_error_queue);
1315 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1316 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1318 if (!sock_flag(sk, SOCK_DEAD)) {
1319 pr_err("Attempt to release alive packet socket: %p\n", sk);
1323 sk_refcnt_debug_dec(sk);
1326 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1331 rxhash = skb_get_hash(skb);
1332 for (i = 0; i < ROLLOVER_HLEN; i++)
1333 if (po->rollover->history[i] == rxhash)
1336 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1337 return count > (ROLLOVER_HLEN >> 1);
1340 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1341 struct sk_buff *skb,
1344 return reciprocal_scale(skb_get_hash(skb), num);
1347 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1348 struct sk_buff *skb,
1351 unsigned int val = atomic_inc_return(&f->rr_cur);
1356 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1357 struct sk_buff *skb,
1360 return smp_processor_id() % num;
1363 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1364 struct sk_buff *skb,
1367 return prandom_u32_max(num);
1370 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1371 struct sk_buff *skb,
1372 unsigned int idx, bool try_self,
1375 struct packet_sock *po, *po_next, *po_skip = NULL;
1376 unsigned int i, j, room = ROOM_NONE;
1378 po = pkt_sk(f->arr[idx]);
1381 room = packet_rcv_has_room(po, skb);
1382 if (room == ROOM_NORMAL ||
1383 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1388 i = j = min_t(int, po->rollover->sock, num - 1);
1390 po_next = pkt_sk(f->arr[i]);
1391 if (po_next != po_skip && !po_next->pressure &&
1392 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1394 po->rollover->sock = i;
1395 atomic_long_inc(&po->rollover->num);
1396 if (room == ROOM_LOW)
1397 atomic_long_inc(&po->rollover->num_huge);
1405 atomic_long_inc(&po->rollover->num_failed);
1409 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1410 struct sk_buff *skb,
1413 return skb_get_queue_mapping(skb) % num;
1416 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1417 struct sk_buff *skb,
1420 struct bpf_prog *prog;
1421 unsigned int ret = 0;
1424 prog = rcu_dereference(f->bpf_prog);
1426 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1432 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1434 return f->flags & (flag >> 8);
1437 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1438 struct packet_type *pt, struct net_device *orig_dev)
1440 struct packet_fanout *f = pt->af_packet_priv;
1441 unsigned int num = READ_ONCE(f->num_members);
1442 struct net *net = read_pnet(&f->net);
1443 struct packet_sock *po;
1446 if (!net_eq(dev_net(dev), net) || !num) {
1451 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1452 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1457 case PACKET_FANOUT_HASH:
1459 idx = fanout_demux_hash(f, skb, num);
1461 case PACKET_FANOUT_LB:
1462 idx = fanout_demux_lb(f, skb, num);
1464 case PACKET_FANOUT_CPU:
1465 idx = fanout_demux_cpu(f, skb, num);
1467 case PACKET_FANOUT_RND:
1468 idx = fanout_demux_rnd(f, skb, num);
1470 case PACKET_FANOUT_QM:
1471 idx = fanout_demux_qm(f, skb, num);
1473 case PACKET_FANOUT_ROLLOVER:
1474 idx = fanout_demux_rollover(f, skb, 0, false, num);
1476 case PACKET_FANOUT_CBPF:
1477 case PACKET_FANOUT_EBPF:
1478 idx = fanout_demux_bpf(f, skb, num);
1482 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1483 idx = fanout_demux_rollover(f, skb, idx, true, num);
1485 po = pkt_sk(f->arr[idx]);
1486 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1489 DEFINE_MUTEX(fanout_mutex);
1490 EXPORT_SYMBOL_GPL(fanout_mutex);
1491 static LIST_HEAD(fanout_list);
1493 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1495 struct packet_fanout *f = po->fanout;
1497 spin_lock(&f->lock);
1498 f->arr[f->num_members] = sk;
1501 spin_unlock(&f->lock);
1504 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1506 struct packet_fanout *f = po->fanout;
1509 spin_lock(&f->lock);
1510 for (i = 0; i < f->num_members; i++) {
1511 if (f->arr[i] == sk)
1514 BUG_ON(i >= f->num_members);
1515 f->arr[i] = f->arr[f->num_members - 1];
1517 spin_unlock(&f->lock);
1520 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1522 if (sk->sk_family != PF_PACKET)
1525 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1528 static void fanout_init_data(struct packet_fanout *f)
1531 case PACKET_FANOUT_LB:
1532 atomic_set(&f->rr_cur, 0);
1534 case PACKET_FANOUT_CBPF:
1535 case PACKET_FANOUT_EBPF:
1536 RCU_INIT_POINTER(f->bpf_prog, NULL);
1541 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1543 struct bpf_prog *old;
1545 spin_lock(&f->lock);
1546 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1547 rcu_assign_pointer(f->bpf_prog, new);
1548 spin_unlock(&f->lock);
1552 bpf_prog_destroy(old);
1556 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1559 struct bpf_prog *new;
1560 struct sock_fprog fprog;
1563 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1565 if (len != sizeof(fprog))
1567 if (copy_from_user(&fprog, data, len))
1570 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1574 __fanout_set_data_bpf(po->fanout, new);
1578 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1581 struct bpf_prog *new;
1584 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1586 if (len != sizeof(fd))
1588 if (copy_from_user(&fd, data, len))
1591 new = bpf_prog_get(fd);
1593 return PTR_ERR(new);
1594 if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) {
1599 __fanout_set_data_bpf(po->fanout, new);
1603 static int fanout_set_data(struct packet_sock *po, char __user *data,
1606 switch (po->fanout->type) {
1607 case PACKET_FANOUT_CBPF:
1608 return fanout_set_data_cbpf(po, data, len);
1609 case PACKET_FANOUT_EBPF:
1610 return fanout_set_data_ebpf(po, data, len);
1616 static void fanout_release_data(struct packet_fanout *f)
1619 case PACKET_FANOUT_CBPF:
1620 case PACKET_FANOUT_EBPF:
1621 __fanout_set_data_bpf(f, NULL);
1625 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1627 struct packet_sock *po = pkt_sk(sk);
1628 struct packet_fanout *f, *match;
1629 u8 type = type_flags & 0xff;
1630 u8 flags = type_flags >> 8;
1634 case PACKET_FANOUT_ROLLOVER:
1635 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1637 case PACKET_FANOUT_HASH:
1638 case PACKET_FANOUT_LB:
1639 case PACKET_FANOUT_CPU:
1640 case PACKET_FANOUT_RND:
1641 case PACKET_FANOUT_QM:
1642 case PACKET_FANOUT_CBPF:
1643 case PACKET_FANOUT_EBPF:
1655 if (type == PACKET_FANOUT_ROLLOVER ||
1656 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1657 po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL);
1660 atomic_long_set(&po->rollover->num, 0);
1661 atomic_long_set(&po->rollover->num_huge, 0);
1662 atomic_long_set(&po->rollover->num_failed, 0);
1665 mutex_lock(&fanout_mutex);
1667 list_for_each_entry(f, &fanout_list, list) {
1669 read_pnet(&f->net) == sock_net(sk)) {
1675 if (match && match->flags != flags)
1679 match = kzalloc(sizeof(*match), GFP_KERNEL);
1682 write_pnet(&match->net, sock_net(sk));
1685 match->flags = flags;
1686 INIT_LIST_HEAD(&match->list);
1687 spin_lock_init(&match->lock);
1688 atomic_set(&match->sk_ref, 0);
1689 fanout_init_data(match);
1690 match->prot_hook.type = po->prot_hook.type;
1691 match->prot_hook.dev = po->prot_hook.dev;
1692 match->prot_hook.func = packet_rcv_fanout;
1693 match->prot_hook.af_packet_priv = match;
1694 match->prot_hook.id_match = match_fanout_group;
1695 dev_add_pack(&match->prot_hook);
1696 list_add(&match->list, &fanout_list);
1699 if (match->type == type &&
1700 match->prot_hook.type == po->prot_hook.type &&
1701 match->prot_hook.dev == po->prot_hook.dev) {
1703 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1704 __dev_remove_pack(&po->prot_hook);
1706 atomic_inc(&match->sk_ref);
1707 __fanout_link(sk, po);
1712 mutex_unlock(&fanout_mutex);
1714 kfree(po->rollover);
1715 po->rollover = NULL;
1720 static void fanout_release(struct sock *sk)
1722 struct packet_sock *po = pkt_sk(sk);
1723 struct packet_fanout *f;
1729 mutex_lock(&fanout_mutex);
1732 if (atomic_dec_and_test(&f->sk_ref)) {
1734 dev_remove_pack(&f->prot_hook);
1735 fanout_release_data(f);
1738 mutex_unlock(&fanout_mutex);
1741 kfree_rcu(po->rollover, rcu);
1744 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1745 struct sk_buff *skb)
1747 /* Earlier code assumed this would be a VLAN pkt, double-check
1748 * this now that we have the actual packet in hand. We can only
1749 * do this check on Ethernet devices.
1751 if (unlikely(dev->type != ARPHRD_ETHER))
1754 skb_reset_mac_header(skb);
1755 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1758 static const struct proto_ops packet_ops;
1760 static const struct proto_ops packet_ops_spkt;
1762 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1763 struct packet_type *pt, struct net_device *orig_dev)
1766 struct sockaddr_pkt *spkt;
1769 * When we registered the protocol we saved the socket in the data
1770 * field for just this event.
1773 sk = pt->af_packet_priv;
1776 * Yank back the headers [hope the device set this
1777 * right or kerboom...]
1779 * Incoming packets have ll header pulled,
1782 * For outgoing ones skb->data == skb_mac_header(skb)
1783 * so that this procedure is noop.
1786 if (skb->pkt_type == PACKET_LOOPBACK)
1789 if (!net_eq(dev_net(dev), sock_net(sk)))
1792 skb = skb_share_check(skb, GFP_ATOMIC);
1796 /* drop any routing info */
1799 /* drop conntrack reference */
1802 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1804 skb_push(skb, skb->data - skb_mac_header(skb));
1807 * The SOCK_PACKET socket receives _all_ frames.
1810 spkt->spkt_family = dev->type;
1811 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1812 spkt->spkt_protocol = skb->protocol;
1815 * Charge the memory to the socket. This is done specifically
1816 * to prevent sockets using all the memory up.
1819 if (sock_queue_rcv_skb(sk, skb) == 0)
1830 * Output a raw packet to a device layer. This bypasses all the other
1831 * protocol layers and you must therefore supply it with a complete frame
1834 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1837 struct sock *sk = sock->sk;
1838 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1839 struct sk_buff *skb = NULL;
1840 struct net_device *dev;
1846 * Get and verify the address.
1850 if (msg->msg_namelen < sizeof(struct sockaddr))
1852 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1853 proto = saddr->spkt_protocol;
1855 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1858 * Find the device first to size check it
1861 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1864 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1870 if (!(dev->flags & IFF_UP))
1874 * You may not queue a frame bigger than the mtu. This is the lowest level
1875 * raw protocol and you must do your own fragmentation at this level.
1878 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1879 if (!netif_supports_nofcs(dev)) {
1880 err = -EPROTONOSUPPORT;
1883 extra_len = 4; /* We're doing our own CRC */
1887 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1891 size_t reserved = LL_RESERVED_SPACE(dev);
1892 int tlen = dev->needed_tailroom;
1893 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1896 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1899 /* FIXME: Save some space for broken drivers that write a hard
1900 * header at transmission time by themselves. PPP is the notable
1901 * one here. This should really be fixed at the driver level.
1903 skb_reserve(skb, reserved);
1904 skb_reset_network_header(skb);
1906 /* Try to align data part correctly */
1911 skb_reset_network_header(skb);
1913 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1919 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1920 !packet_extra_vlan_len_allowed(dev, skb)) {
1925 skb->protocol = proto;
1927 skb->priority = sk->sk_priority;
1928 skb->mark = sk->sk_mark;
1930 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1932 if (unlikely(extra_len == 4))
1935 skb_probe_transport_header(skb, 0);
1937 dev_queue_xmit(skb);
1948 static unsigned int run_filter(struct sk_buff *skb,
1949 const struct sock *sk,
1952 struct sk_filter *filter;
1955 filter = rcu_dereference(sk->sk_filter);
1957 res = bpf_prog_run_clear_cb(filter->prog, skb);
1963 static int __packet_rcv_vnet(const struct sk_buff *skb,
1964 struct virtio_net_hdr *vnet_hdr)
1966 *vnet_hdr = (const struct virtio_net_hdr) { 0 };
1968 if (skb_is_gso(skb)) {
1969 struct skb_shared_info *sinfo = skb_shinfo(skb);
1971 /* This is a hint as to how much should be linear. */
1973 __cpu_to_virtio16(vio_le(), skb_headlen(skb));
1974 vnet_hdr->gso_size =
1975 __cpu_to_virtio16(vio_le(), sinfo->gso_size);
1977 if (sinfo->gso_type & SKB_GSO_TCPV4)
1978 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1979 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1980 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1981 else if (sinfo->gso_type & SKB_GSO_UDP)
1982 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
1983 else if (sinfo->gso_type & SKB_GSO_FCOE)
1988 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1989 vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1991 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
1993 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1994 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1995 vnet_hdr->csum_start = __cpu_to_virtio16(vio_le(),
1996 skb_checksum_start_offset(skb));
1997 vnet_hdr->csum_offset = __cpu_to_virtio16(vio_le(),
1999 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2000 vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
2001 } /* else everything is zero */
2006 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2009 struct virtio_net_hdr vnet_hdr;
2011 if (*len < sizeof(vnet_hdr))
2013 *len -= sizeof(vnet_hdr);
2015 if (__packet_rcv_vnet(skb, &vnet_hdr))
2018 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2022 * This function makes lazy skb cloning in hope that most of packets
2023 * are discarded by BPF.
2025 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2026 * and skb->cb are mangled. It works because (and until) packets
2027 * falling here are owned by current CPU. Output packets are cloned
2028 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2029 * sequencially, so that if we return skb to original state on exit,
2030 * we will not harm anyone.
2033 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2034 struct packet_type *pt, struct net_device *orig_dev)
2037 struct sockaddr_ll *sll;
2038 struct packet_sock *po;
2039 u8 *skb_head = skb->data;
2040 int skb_len = skb->len;
2041 unsigned int snaplen, res;
2043 if (skb->pkt_type == PACKET_LOOPBACK)
2046 sk = pt->af_packet_priv;
2049 if (!net_eq(dev_net(dev), sock_net(sk)))
2054 if (dev->header_ops) {
2055 /* The device has an explicit notion of ll header,
2056 * exported to higher levels.
2058 * Otherwise, the device hides details of its frame
2059 * structure, so that corresponding packet head is
2060 * never delivered to user.
2062 if (sk->sk_type != SOCK_DGRAM)
2063 skb_push(skb, skb->data - skb_mac_header(skb));
2064 else if (skb->pkt_type == PACKET_OUTGOING) {
2065 /* Special case: outgoing packets have ll header at head */
2066 skb_pull(skb, skb_network_offset(skb));
2072 res = run_filter(skb, sk, snaplen);
2074 goto drop_n_restore;
2078 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2081 if (skb_shared(skb)) {
2082 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2086 if (skb_head != skb->data) {
2087 skb->data = skb_head;
2094 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2096 sll = &PACKET_SKB_CB(skb)->sa.ll;
2097 sll->sll_hatype = dev->type;
2098 sll->sll_pkttype = skb->pkt_type;
2099 if (unlikely(po->origdev))
2100 sll->sll_ifindex = orig_dev->ifindex;
2102 sll->sll_ifindex = dev->ifindex;
2104 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2106 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2107 * Use their space for storing the original skb length.
2109 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2111 if (pskb_trim(skb, snaplen))
2114 skb_set_owner_r(skb, sk);
2118 /* drop conntrack reference */
2121 spin_lock(&sk->sk_receive_queue.lock);
2122 po->stats.stats1.tp_packets++;
2123 sock_skb_set_dropcount(sk, skb);
2124 __skb_queue_tail(&sk->sk_receive_queue, skb);
2125 spin_unlock(&sk->sk_receive_queue.lock);
2126 sk->sk_data_ready(sk);
2130 spin_lock(&sk->sk_receive_queue.lock);
2131 po->stats.stats1.tp_drops++;
2132 atomic_inc(&sk->sk_drops);
2133 spin_unlock(&sk->sk_receive_queue.lock);
2136 if (skb_head != skb->data && skb_shared(skb)) {
2137 skb->data = skb_head;
2145 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2146 struct packet_type *pt, struct net_device *orig_dev)
2149 struct packet_sock *po;
2150 struct sockaddr_ll *sll;
2151 union tpacket_uhdr h;
2152 u8 *skb_head = skb->data;
2153 int skb_len = skb->len;
2154 unsigned int snaplen, res;
2155 unsigned long status = TP_STATUS_USER;
2156 unsigned short macoff, netoff, hdrlen;
2157 struct sk_buff *copy_skb = NULL;
2161 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2162 * We may add members to them until current aligned size without forcing
2163 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2165 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2166 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2168 if (skb->pkt_type == PACKET_LOOPBACK)
2171 sk = pt->af_packet_priv;
2174 if (!net_eq(dev_net(dev), sock_net(sk)))
2177 if (dev->header_ops) {
2178 if (sk->sk_type != SOCK_DGRAM)
2179 skb_push(skb, skb->data - skb_mac_header(skb));
2180 else if (skb->pkt_type == PACKET_OUTGOING) {
2181 /* Special case: outgoing packets have ll header at head */
2182 skb_pull(skb, skb_network_offset(skb));
2188 res = run_filter(skb, sk, snaplen);
2190 goto drop_n_restore;
2192 if (skb->ip_summed == CHECKSUM_PARTIAL)
2193 status |= TP_STATUS_CSUMNOTREADY;
2194 else if (skb->pkt_type != PACKET_OUTGOING &&
2195 (skb->ip_summed == CHECKSUM_COMPLETE ||
2196 skb_csum_unnecessary(skb)))
2197 status |= TP_STATUS_CSUM_VALID;
2202 if (sk->sk_type == SOCK_DGRAM) {
2203 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2206 unsigned int maclen = skb_network_offset(skb);
2207 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2208 (maclen < 16 ? 16 : maclen)) +
2210 if (po->has_vnet_hdr)
2211 netoff += sizeof(struct virtio_net_hdr);
2212 macoff = netoff - maclen;
2214 if (po->tp_version <= TPACKET_V2) {
2215 if (macoff + snaplen > po->rx_ring.frame_size) {
2216 if (po->copy_thresh &&
2217 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2218 if (skb_shared(skb)) {
2219 copy_skb = skb_clone(skb, GFP_ATOMIC);
2221 copy_skb = skb_get(skb);
2222 skb_head = skb->data;
2225 skb_set_owner_r(copy_skb, sk);
2227 snaplen = po->rx_ring.frame_size - macoff;
2228 if ((int)snaplen < 0)
2231 } else if (unlikely(macoff + snaplen >
2232 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2235 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2236 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2237 snaplen, nval, macoff);
2239 if (unlikely((int)snaplen < 0)) {
2241 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2244 spin_lock(&sk->sk_receive_queue.lock);
2245 h.raw = packet_current_rx_frame(po, skb,
2246 TP_STATUS_KERNEL, (macoff+snaplen));
2248 goto drop_n_account;
2249 if (po->tp_version <= TPACKET_V2) {
2250 packet_increment_rx_head(po, &po->rx_ring);
2252 * LOSING will be reported till you read the stats,
2253 * because it's COR - Clear On Read.
2254 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2257 if (po->stats.stats1.tp_drops)
2258 status |= TP_STATUS_LOSING;
2260 po->stats.stats1.tp_packets++;
2262 status |= TP_STATUS_COPY;
2263 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2265 spin_unlock(&sk->sk_receive_queue.lock);
2267 if (po->has_vnet_hdr) {
2268 if (__packet_rcv_vnet(skb, h.raw + macoff -
2269 sizeof(struct virtio_net_hdr))) {
2270 spin_lock(&sk->sk_receive_queue.lock);
2271 goto drop_n_account;
2275 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2277 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2278 getnstimeofday(&ts);
2280 status |= ts_status;
2282 switch (po->tp_version) {
2284 h.h1->tp_len = skb->len;
2285 h.h1->tp_snaplen = snaplen;
2286 h.h1->tp_mac = macoff;
2287 h.h1->tp_net = netoff;
2288 h.h1->tp_sec = ts.tv_sec;
2289 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2290 hdrlen = sizeof(*h.h1);
2293 h.h2->tp_len = skb->len;
2294 h.h2->tp_snaplen = snaplen;
2295 h.h2->tp_mac = macoff;
2296 h.h2->tp_net = netoff;
2297 h.h2->tp_sec = ts.tv_sec;
2298 h.h2->tp_nsec = ts.tv_nsec;
2299 if (skb_vlan_tag_present(skb)) {
2300 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2301 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2302 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2304 h.h2->tp_vlan_tci = 0;
2305 h.h2->tp_vlan_tpid = 0;
2307 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2308 hdrlen = sizeof(*h.h2);
2311 /* tp_nxt_offset,vlan are already populated above.
2312 * So DONT clear those fields here
2314 h.h3->tp_status |= status;
2315 h.h3->tp_len = skb->len;
2316 h.h3->tp_snaplen = snaplen;
2317 h.h3->tp_mac = macoff;
2318 h.h3->tp_net = netoff;
2319 h.h3->tp_sec = ts.tv_sec;
2320 h.h3->tp_nsec = ts.tv_nsec;
2321 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2322 hdrlen = sizeof(*h.h3);
2328 sll = h.raw + TPACKET_ALIGN(hdrlen);
2329 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2330 sll->sll_family = AF_PACKET;
2331 sll->sll_hatype = dev->type;
2332 sll->sll_protocol = skb->protocol;
2333 sll->sll_pkttype = skb->pkt_type;
2334 if (unlikely(po->origdev))
2335 sll->sll_ifindex = orig_dev->ifindex;
2337 sll->sll_ifindex = dev->ifindex;
2341 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2342 if (po->tp_version <= TPACKET_V2) {
2345 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2348 for (start = h.raw; start < end; start += PAGE_SIZE)
2349 flush_dcache_page(pgv_to_page(start));
2354 if (po->tp_version <= TPACKET_V2) {
2355 __packet_set_status(po, h.raw, status);
2356 sk->sk_data_ready(sk);
2358 prb_clear_blk_fill_status(&po->rx_ring);
2362 if (skb_head != skb->data && skb_shared(skb)) {
2363 skb->data = skb_head;
2371 po->stats.stats1.tp_drops++;
2372 spin_unlock(&sk->sk_receive_queue.lock);
2374 sk->sk_data_ready(sk);
2375 kfree_skb(copy_skb);
2376 goto drop_n_restore;
2379 static void tpacket_destruct_skb(struct sk_buff *skb)
2381 struct packet_sock *po = pkt_sk(skb->sk);
2383 if (likely(po->tx_ring.pg_vec)) {
2387 ph = skb_shinfo(skb)->destructor_arg;
2388 packet_dec_pending(&po->tx_ring);
2390 ts = __packet_set_timestamp(po, ph, skb);
2391 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2397 static bool ll_header_truncated(const struct net_device *dev, int len)
2399 /* net device doesn't like empty head */
2400 if (unlikely(len < dev->hard_header_len)) {
2401 net_warn_ratelimited("%s: packet size is too short (%d < %d)\n",
2402 current->comm, len, dev->hard_header_len);
2409 static void tpacket_set_protocol(const struct net_device *dev,
2410 struct sk_buff *skb)
2412 if (dev->type == ARPHRD_ETHER) {
2413 skb_reset_mac_header(skb);
2414 skb->protocol = eth_hdr(skb)->h_proto;
2418 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2420 unsigned short gso_type = 0;
2422 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2423 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2424 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2425 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2426 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2427 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2428 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2430 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2433 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2434 switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2435 case VIRTIO_NET_HDR_GSO_TCPV4:
2436 gso_type = SKB_GSO_TCPV4;
2438 case VIRTIO_NET_HDR_GSO_TCPV6:
2439 gso_type = SKB_GSO_TCPV6;
2441 case VIRTIO_NET_HDR_GSO_UDP:
2442 gso_type = SKB_GSO_UDP;
2448 if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
2449 gso_type |= SKB_GSO_TCP_ECN;
2451 if (vnet_hdr->gso_size == 0)
2455 vnet_hdr->gso_type = gso_type; /* changes type, temporary storage */
2459 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2460 struct virtio_net_hdr *vnet_hdr)
2464 if (*len < sizeof(*vnet_hdr))
2466 *len -= sizeof(*vnet_hdr);
2468 n = copy_from_iter(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter);
2469 if (n != sizeof(*vnet_hdr))
2472 return __packet_snd_vnet_parse(vnet_hdr, *len);
2475 static int packet_snd_vnet_gso(struct sk_buff *skb,
2476 struct virtio_net_hdr *vnet_hdr)
2478 if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2479 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start);
2480 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset);
2482 if (!skb_partial_csum_set(skb, s, o))
2486 skb_shinfo(skb)->gso_size =
2487 __virtio16_to_cpu(vio_le(), vnet_hdr->gso_size);
2488 skb_shinfo(skb)->gso_type = vnet_hdr->gso_type;
2490 /* Header must be checked, and gso_segs computed. */
2491 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2492 skb_shinfo(skb)->gso_segs = 0;
2496 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2497 void *frame, struct net_device *dev, void *data, int tp_len,
2498 __be16 proto, unsigned char *addr, int hlen)
2500 union tpacket_uhdr ph;
2501 int to_write, offset, len, nr_frags, len_max;
2502 struct socket *sock = po->sk.sk_socket;
2508 skb->protocol = proto;
2510 skb->priority = po->sk.sk_priority;
2511 skb->mark = po->sk.sk_mark;
2512 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2513 skb_shinfo(skb)->destructor_arg = ph.raw;
2515 skb_reserve(skb, hlen);
2516 skb_reset_network_header(skb);
2520 if (sock->type == SOCK_DGRAM) {
2521 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2523 if (unlikely(err < 0))
2525 } else if (dev->hard_header_len) {
2526 if (ll_header_truncated(dev, tp_len))
2529 skb_push(skb, dev->hard_header_len);
2530 err = skb_store_bits(skb, 0, data,
2531 dev->hard_header_len);
2535 tpacket_set_protocol(dev, skb);
2537 data += dev->hard_header_len;
2538 to_write -= dev->hard_header_len;
2541 offset = offset_in_page(data);
2542 len_max = PAGE_SIZE - offset;
2543 len = ((to_write > len_max) ? len_max : to_write);
2545 skb->data_len = to_write;
2546 skb->len += to_write;
2547 skb->truesize += to_write;
2548 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2550 while (likely(to_write)) {
2551 nr_frags = skb_shinfo(skb)->nr_frags;
2553 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2554 pr_err("Packet exceed the number of skb frags(%lu)\n",
2559 page = pgv_to_page(data);
2561 flush_dcache_page(page);
2563 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2566 len_max = PAGE_SIZE;
2567 len = ((to_write > len_max) ? len_max : to_write);
2570 skb_probe_transport_header(skb, 0);
2575 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2576 int size_max, void **data)
2578 union tpacket_uhdr ph;
2583 switch (po->tp_version) {
2585 tp_len = ph.h2->tp_len;
2588 tp_len = ph.h1->tp_len;
2591 if (unlikely(tp_len > size_max)) {
2592 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2596 if (unlikely(po->tp_tx_has_off)) {
2597 int off_min, off_max;
2599 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2600 off_max = po->tx_ring.frame_size - tp_len;
2601 if (po->sk.sk_type == SOCK_DGRAM) {
2602 switch (po->tp_version) {
2604 off = ph.h2->tp_net;
2607 off = ph.h1->tp_net;
2611 switch (po->tp_version) {
2613 off = ph.h2->tp_mac;
2616 off = ph.h1->tp_mac;
2620 if (unlikely((off < off_min) || (off_max < off)))
2623 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2626 *data = frame + off;
2630 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2632 struct sk_buff *skb;
2633 struct net_device *dev;
2635 int err, reserve = 0;
2637 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2638 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2639 int tp_len, size_max;
2640 unsigned char *addr;
2643 int status = TP_STATUS_AVAILABLE;
2646 mutex_lock(&po->pg_vec_lock);
2648 if (likely(saddr == NULL)) {
2649 dev = packet_cached_dev_get(po);
2654 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2656 if (msg->msg_namelen < (saddr->sll_halen
2657 + offsetof(struct sockaddr_ll,
2660 proto = saddr->sll_protocol;
2661 addr = saddr->sll_addr;
2662 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2666 if (unlikely(dev == NULL))
2669 if (unlikely(!(dev->flags & IFF_UP)))
2672 if (po->sk.sk_socket->type == SOCK_RAW)
2673 reserve = dev->hard_header_len;
2674 size_max = po->tx_ring.frame_size
2675 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2677 if (size_max > dev->mtu + reserve + VLAN_HLEN)
2678 size_max = dev->mtu + reserve + VLAN_HLEN;
2681 ph = packet_current_frame(po, &po->tx_ring,
2682 TP_STATUS_SEND_REQUEST);
2683 if (unlikely(ph == NULL)) {
2684 if (need_wait && need_resched())
2690 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2694 status = TP_STATUS_SEND_REQUEST;
2695 hlen = LL_RESERVED_SPACE(dev);
2696 tlen = dev->needed_tailroom;
2697 skb = sock_alloc_send_skb(&po->sk,
2698 hlen + tlen + sizeof(struct sockaddr_ll),
2701 if (unlikely(skb == NULL)) {
2702 /* we assume the socket was initially writeable ... */
2703 if (likely(len_sum > 0))
2707 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2709 if (likely(tp_len >= 0) &&
2710 tp_len > dev->mtu + reserve &&
2711 !packet_extra_vlan_len_allowed(dev, skb))
2714 if (unlikely(tp_len < 0)) {
2717 __packet_set_status(po, ph,
2718 TP_STATUS_AVAILABLE);
2719 packet_increment_head(&po->tx_ring);
2723 status = TP_STATUS_WRONG_FORMAT;
2729 packet_pick_tx_queue(dev, skb);
2731 skb->destructor = tpacket_destruct_skb;
2732 __packet_set_status(po, ph, TP_STATUS_SENDING);
2733 packet_inc_pending(&po->tx_ring);
2735 status = TP_STATUS_SEND_REQUEST;
2736 err = po->xmit(skb);
2737 if (unlikely(err > 0)) {
2738 err = net_xmit_errno(err);
2739 if (err && __packet_get_status(po, ph) ==
2740 TP_STATUS_AVAILABLE) {
2741 /* skb was destructed already */
2746 * skb was dropped but not destructed yet;
2747 * let's treat it like congestion or err < 0
2751 packet_increment_head(&po->tx_ring);
2753 } while (likely((ph != NULL) ||
2754 /* Note: packet_read_pending() might be slow if we have
2755 * to call it as it's per_cpu variable, but in fast-path
2756 * we already short-circuit the loop with the first
2757 * condition, and luckily don't have to go that path
2760 (need_wait && packet_read_pending(&po->tx_ring))));
2766 __packet_set_status(po, ph, status);
2771 mutex_unlock(&po->pg_vec_lock);
2775 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2776 size_t reserve, size_t len,
2777 size_t linear, int noblock,
2780 struct sk_buff *skb;
2782 /* Under a page? Don't bother with paged skb. */
2783 if (prepad + len < PAGE_SIZE || !linear)
2786 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2791 skb_reserve(skb, reserve);
2792 skb_put(skb, linear);
2793 skb->data_len = len - linear;
2794 skb->len += len - linear;
2799 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2801 struct sock *sk = sock->sk;
2802 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2803 struct sk_buff *skb;
2804 struct net_device *dev;
2806 unsigned char *addr;
2807 int err, reserve = 0;
2808 struct sockcm_cookie sockc;
2809 struct virtio_net_hdr vnet_hdr = { 0 };
2811 struct packet_sock *po = pkt_sk(sk);
2816 * Get and verify the address.
2819 if (likely(saddr == NULL)) {
2820 dev = packet_cached_dev_get(po);
2825 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2827 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2829 proto = saddr->sll_protocol;
2830 addr = saddr->sll_addr;
2831 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2835 if (unlikely(dev == NULL))
2838 if (unlikely(!(dev->flags & IFF_UP)))
2841 sockc.mark = sk->sk_mark;
2842 if (msg->msg_controllen) {
2843 err = sock_cmsg_send(sk, msg, &sockc);
2848 if (sock->type == SOCK_RAW)
2849 reserve = dev->hard_header_len;
2850 if (po->has_vnet_hdr) {
2851 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2856 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2857 if (!netif_supports_nofcs(dev)) {
2858 err = -EPROTONOSUPPORT;
2861 extra_len = 4; /* We're doing our own CRC */
2865 if (!vnet_hdr.gso_type &&
2866 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2870 hlen = LL_RESERVED_SPACE(dev);
2871 tlen = dev->needed_tailroom;
2872 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
2873 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len),
2874 msg->msg_flags & MSG_DONTWAIT, &err);
2878 skb_set_network_header(skb, reserve);
2881 if (sock->type == SOCK_DGRAM) {
2882 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2883 if (unlikely(offset < 0))
2886 if (ll_header_truncated(dev, len))
2890 /* Returns -EFAULT on error */
2891 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2895 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2897 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2898 !packet_extra_vlan_len_allowed(dev, skb)) {
2903 skb->protocol = proto;
2905 skb->priority = sk->sk_priority;
2906 skb->mark = sockc.mark;
2908 packet_pick_tx_queue(dev, skb);
2910 if (po->has_vnet_hdr) {
2911 err = packet_snd_vnet_gso(skb, &vnet_hdr);
2914 len += sizeof(vnet_hdr);
2917 skb_probe_transport_header(skb, reserve);
2919 if (unlikely(extra_len == 4))
2922 err = po->xmit(skb);
2923 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2939 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2941 struct sock *sk = sock->sk;
2942 struct packet_sock *po = pkt_sk(sk);
2944 if (po->tx_ring.pg_vec)
2945 return tpacket_snd(po, msg);
2947 return packet_snd(sock, msg, len);
2951 * Close a PACKET socket. This is fairly simple. We immediately go
2952 * to 'closed' state and remove our protocol entry in the device list.
2955 static int packet_release(struct socket *sock)
2957 struct sock *sk = sock->sk;
2958 struct packet_sock *po;
2960 union tpacket_req_u req_u;
2968 mutex_lock(&net->packet.sklist_lock);
2969 sk_del_node_init_rcu(sk);
2970 mutex_unlock(&net->packet.sklist_lock);
2973 sock_prot_inuse_add(net, sk->sk_prot, -1);
2976 spin_lock(&po->bind_lock);
2977 unregister_prot_hook(sk, false);
2978 packet_cached_dev_reset(po);
2980 if (po->prot_hook.dev) {
2981 dev_put(po->prot_hook.dev);
2982 po->prot_hook.dev = NULL;
2984 spin_unlock(&po->bind_lock);
2986 packet_flush_mclist(sk);
2988 if (po->rx_ring.pg_vec) {
2989 memset(&req_u, 0, sizeof(req_u));
2990 packet_set_ring(sk, &req_u, 1, 0);
2993 if (po->tx_ring.pg_vec) {
2994 memset(&req_u, 0, sizeof(req_u));
2995 packet_set_ring(sk, &req_u, 1, 1);
3002 * Now the socket is dead. No more input will appear.
3009 skb_queue_purge(&sk->sk_receive_queue);
3010 packet_free_pending(po);
3011 sk_refcnt_debug_release(sk);
3018 * Attach a packet hook.
3021 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3024 struct packet_sock *po = pkt_sk(sk);
3025 struct net_device *dev_curr;
3028 struct net_device *dev = NULL;
3030 bool unlisted = false;
3036 spin_lock(&po->bind_lock);
3040 dev = dev_get_by_name_rcu(sock_net(sk), name);
3045 } else if (ifindex) {
3046 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3056 proto_curr = po->prot_hook.type;
3057 dev_curr = po->prot_hook.dev;
3059 need_rehook = proto_curr != proto || dev_curr != dev;
3064 __unregister_prot_hook(sk, true);
3066 dev_curr = po->prot_hook.dev;
3068 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3073 po->prot_hook.type = proto;
3075 if (unlikely(unlisted)) {
3077 po->prot_hook.dev = NULL;
3079 packet_cached_dev_reset(po);
3081 po->prot_hook.dev = dev;
3082 po->ifindex = dev ? dev->ifindex : 0;
3083 packet_cached_dev_assign(po, dev);
3089 if (proto == 0 || !need_rehook)
3092 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3093 register_prot_hook(sk);
3095 sk->sk_err = ENETDOWN;
3096 if (!sock_flag(sk, SOCK_DEAD))
3097 sk->sk_error_report(sk);
3102 spin_unlock(&po->bind_lock);
3108 * Bind a packet socket to a device
3111 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3114 struct sock *sk = sock->sk;
3121 if (addr_len != sizeof(struct sockaddr))
3123 strlcpy(name, uaddr->sa_data, sizeof(name));
3125 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3128 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3130 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3131 struct sock *sk = sock->sk;
3137 if (addr_len < sizeof(struct sockaddr_ll))
3139 if (sll->sll_family != AF_PACKET)
3142 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3143 sll->sll_protocol ? : pkt_sk(sk)->num);
3146 static struct proto packet_proto = {
3148 .owner = THIS_MODULE,
3149 .obj_size = sizeof(struct packet_sock),
3153 * Create a packet of type SOCK_PACKET.
3156 static int packet_create(struct net *net, struct socket *sock, int protocol,
3160 struct packet_sock *po;
3161 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3164 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3166 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3167 sock->type != SOCK_PACKET)
3168 return -ESOCKTNOSUPPORT;
3170 sock->state = SS_UNCONNECTED;
3173 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3177 sock->ops = &packet_ops;
3178 if (sock->type == SOCK_PACKET)
3179 sock->ops = &packet_ops_spkt;
3181 sock_init_data(sock, sk);
3184 sk->sk_family = PF_PACKET;
3186 po->xmit = dev_queue_xmit;
3188 err = packet_alloc_pending(po);
3192 packet_cached_dev_reset(po);
3194 sk->sk_destruct = packet_sock_destruct;
3195 sk_refcnt_debug_inc(sk);
3198 * Attach a protocol block
3201 spin_lock_init(&po->bind_lock);
3202 mutex_init(&po->pg_vec_lock);
3203 po->rollover = NULL;
3204 po->prot_hook.func = packet_rcv;
3206 if (sock->type == SOCK_PACKET)
3207 po->prot_hook.func = packet_rcv_spkt;
3209 po->prot_hook.af_packet_priv = sk;
3212 po->prot_hook.type = proto;
3213 register_prot_hook(sk);
3216 mutex_lock(&net->packet.sklist_lock);
3217 sk_add_node_rcu(sk, &net->packet.sklist);
3218 mutex_unlock(&net->packet.sklist_lock);
3221 sock_prot_inuse_add(net, &packet_proto, 1);
3232 * Pull a packet from our receive queue and hand it to the user.
3233 * If necessary we block.
3236 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3239 struct sock *sk = sock->sk;
3240 struct sk_buff *skb;
3242 int vnet_hdr_len = 0;
3243 unsigned int origlen = 0;
3246 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3250 /* What error should we return now? EUNATTACH? */
3251 if (pkt_sk(sk)->ifindex < 0)
3255 if (flags & MSG_ERRQUEUE) {
3256 err = sock_recv_errqueue(sk, msg, len,
3257 SOL_PACKET, PACKET_TX_TIMESTAMP);
3262 * Call the generic datagram receiver. This handles all sorts
3263 * of horrible races and re-entrancy so we can forget about it
3264 * in the protocol layers.
3266 * Now it will return ENETDOWN, if device have just gone down,
3267 * but then it will block.
3270 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3273 * An error occurred so return it. Because skb_recv_datagram()
3274 * handles the blocking we don't see and worry about blocking
3281 if (pkt_sk(sk)->pressure)
3282 packet_rcv_has_room(pkt_sk(sk), NULL);
3284 if (pkt_sk(sk)->has_vnet_hdr) {
3285 err = packet_rcv_vnet(msg, skb, &len);
3288 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3291 /* You lose any data beyond the buffer you gave. If it worries
3292 * a user program they can ask the device for its MTU
3298 msg->msg_flags |= MSG_TRUNC;
3301 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3305 if (sock->type != SOCK_PACKET) {
3306 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3308 /* Original length was stored in sockaddr_ll fields */
3309 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3310 sll->sll_family = AF_PACKET;
3311 sll->sll_protocol = skb->protocol;
3314 sock_recv_ts_and_drops(msg, sk, skb);
3316 if (msg->msg_name) {
3317 /* If the address length field is there to be filled
3318 * in, we fill it in now.
3320 if (sock->type == SOCK_PACKET) {
3321 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3322 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3324 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3326 msg->msg_namelen = sll->sll_halen +
3327 offsetof(struct sockaddr_ll, sll_addr);
3329 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3333 if (pkt_sk(sk)->auxdata) {
3334 struct tpacket_auxdata aux;
3336 aux.tp_status = TP_STATUS_USER;
3337 if (skb->ip_summed == CHECKSUM_PARTIAL)
3338 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3339 else if (skb->pkt_type != PACKET_OUTGOING &&
3340 (skb->ip_summed == CHECKSUM_COMPLETE ||
3341 skb_csum_unnecessary(skb)))
3342 aux.tp_status |= TP_STATUS_CSUM_VALID;
3344 aux.tp_len = origlen;
3345 aux.tp_snaplen = skb->len;
3347 aux.tp_net = skb_network_offset(skb);
3348 if (skb_vlan_tag_present(skb)) {
3349 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3350 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3351 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3353 aux.tp_vlan_tci = 0;
3354 aux.tp_vlan_tpid = 0;
3356 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3360 * Free or return the buffer as appropriate. Again this
3361 * hides all the races and re-entrancy issues from us.
3363 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3366 skb_free_datagram(sk, skb);
3371 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3372 int *uaddr_len, int peer)
3374 struct net_device *dev;
3375 struct sock *sk = sock->sk;
3380 uaddr->sa_family = AF_PACKET;
3381 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3383 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3385 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3387 *uaddr_len = sizeof(*uaddr);
3392 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3393 int *uaddr_len, int peer)
3395 struct net_device *dev;
3396 struct sock *sk = sock->sk;
3397 struct packet_sock *po = pkt_sk(sk);
3398 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3403 sll->sll_family = AF_PACKET;
3404 sll->sll_ifindex = po->ifindex;
3405 sll->sll_protocol = po->num;
3406 sll->sll_pkttype = 0;
3408 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3410 sll->sll_hatype = dev->type;
3411 sll->sll_halen = dev->addr_len;
3412 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3414 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3418 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3423 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3427 case PACKET_MR_MULTICAST:
3428 if (i->alen != dev->addr_len)
3431 return dev_mc_add(dev, i->addr);
3433 return dev_mc_del(dev, i->addr);
3435 case PACKET_MR_PROMISC:
3436 return dev_set_promiscuity(dev, what);
3437 case PACKET_MR_ALLMULTI:
3438 return dev_set_allmulti(dev, what);
3439 case PACKET_MR_UNICAST:
3440 if (i->alen != dev->addr_len)
3443 return dev_uc_add(dev, i->addr);
3445 return dev_uc_del(dev, i->addr);
3453 static void packet_dev_mclist_delete(struct net_device *dev,
3454 struct packet_mclist **mlp)
3456 struct packet_mclist *ml;
3458 while ((ml = *mlp) != NULL) {
3459 if (ml->ifindex == dev->ifindex) {
3460 packet_dev_mc(dev, ml, -1);
3468 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3470 struct packet_sock *po = pkt_sk(sk);
3471 struct packet_mclist *ml, *i;
3472 struct net_device *dev;
3478 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3483 if (mreq->mr_alen > dev->addr_len)
3487 i = kmalloc(sizeof(*i), GFP_KERNEL);
3492 for (ml = po->mclist; ml; ml = ml->next) {
3493 if (ml->ifindex == mreq->mr_ifindex &&
3494 ml->type == mreq->mr_type &&
3495 ml->alen == mreq->mr_alen &&
3496 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3498 /* Free the new element ... */
3504 i->type = mreq->mr_type;
3505 i->ifindex = mreq->mr_ifindex;
3506 i->alen = mreq->mr_alen;
3507 memcpy(i->addr, mreq->mr_address, i->alen);
3509 i->next = po->mclist;
3511 err = packet_dev_mc(dev, i, 1);
3513 po->mclist = i->next;
3522 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3524 struct packet_mclist *ml, **mlp;
3528 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3529 if (ml->ifindex == mreq->mr_ifindex &&
3530 ml->type == mreq->mr_type &&
3531 ml->alen == mreq->mr_alen &&
3532 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3533 if (--ml->count == 0) {
3534 struct net_device *dev;
3536 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3538 packet_dev_mc(dev, ml, -1);
3548 static void packet_flush_mclist(struct sock *sk)
3550 struct packet_sock *po = pkt_sk(sk);
3551 struct packet_mclist *ml;
3557 while ((ml = po->mclist) != NULL) {
3558 struct net_device *dev;
3560 po->mclist = ml->next;
3561 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3563 packet_dev_mc(dev, ml, -1);
3570 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3572 struct sock *sk = sock->sk;
3573 struct packet_sock *po = pkt_sk(sk);
3576 if (level != SOL_PACKET)
3577 return -ENOPROTOOPT;
3580 case PACKET_ADD_MEMBERSHIP:
3581 case PACKET_DROP_MEMBERSHIP:
3583 struct packet_mreq_max mreq;
3585 memset(&mreq, 0, sizeof(mreq));
3586 if (len < sizeof(struct packet_mreq))
3588 if (len > sizeof(mreq))
3590 if (copy_from_user(&mreq, optval, len))
3592 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3594 if (optname == PACKET_ADD_MEMBERSHIP)
3595 ret = packet_mc_add(sk, &mreq);
3597 ret = packet_mc_drop(sk, &mreq);
3601 case PACKET_RX_RING:
3602 case PACKET_TX_RING:
3604 union tpacket_req_u req_u;
3607 switch (po->tp_version) {
3610 len = sizeof(req_u.req);
3614 len = sizeof(req_u.req3);
3619 if (pkt_sk(sk)->has_vnet_hdr &&
3620 optname == PACKET_TX_RING)
3622 if (copy_from_user(&req_u.req, optval, len))
3624 return packet_set_ring(sk, &req_u, 0,
3625 optname == PACKET_TX_RING);
3627 case PACKET_COPY_THRESH:
3631 if (optlen != sizeof(val))
3633 if (copy_from_user(&val, optval, sizeof(val)))
3636 pkt_sk(sk)->copy_thresh = val;
3639 case PACKET_VERSION:
3643 if (optlen != sizeof(val))
3645 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3647 if (copy_from_user(&val, optval, sizeof(val)))
3653 po->tp_version = val;
3659 case PACKET_RESERVE:
3663 if (optlen != sizeof(val))
3665 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3667 if (copy_from_user(&val, optval, sizeof(val)))
3669 po->tp_reserve = val;
3676 if (optlen != sizeof(val))
3678 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3680 if (copy_from_user(&val, optval, sizeof(val)))
3682 po->tp_loss = !!val;
3685 case PACKET_AUXDATA:
3689 if (optlen < sizeof(val))
3691 if (copy_from_user(&val, optval, sizeof(val)))
3694 po->auxdata = !!val;
3697 case PACKET_ORIGDEV:
3701 if (optlen < sizeof(val))
3703 if (copy_from_user(&val, optval, sizeof(val)))
3706 po->origdev = !!val;
3709 case PACKET_VNET_HDR:
3713 if (sock->type != SOCK_RAW)
3715 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3717 if (optlen < sizeof(val))
3719 if (copy_from_user(&val, optval, sizeof(val)))
3722 po->has_vnet_hdr = !!val;
3725 case PACKET_TIMESTAMP:
3729 if (optlen != sizeof(val))
3731 if (copy_from_user(&val, optval, sizeof(val)))
3734 po->tp_tstamp = val;
3741 if (optlen != sizeof(val))
3743 if (copy_from_user(&val, optval, sizeof(val)))
3746 return fanout_add(sk, val & 0xffff, val >> 16);
3748 case PACKET_FANOUT_DATA:
3753 return fanout_set_data(po, optval, optlen);
3755 case PACKET_TX_HAS_OFF:
3759 if (optlen != sizeof(val))
3761 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3763 if (copy_from_user(&val, optval, sizeof(val)))
3765 po->tp_tx_has_off = !!val;
3768 case PACKET_QDISC_BYPASS:
3772 if (optlen != sizeof(val))
3774 if (copy_from_user(&val, optval, sizeof(val)))
3777 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3781 return -ENOPROTOOPT;
3785 static int packet_getsockopt(struct socket *sock, int level, int optname,
3786 char __user *optval, int __user *optlen)
3789 int val, lv = sizeof(val);
3790 struct sock *sk = sock->sk;
3791 struct packet_sock *po = pkt_sk(sk);
3793 union tpacket_stats_u st;
3794 struct tpacket_rollover_stats rstats;
3796 if (level != SOL_PACKET)
3797 return -ENOPROTOOPT;
3799 if (get_user(len, optlen))
3806 case PACKET_STATISTICS:
3807 spin_lock_bh(&sk->sk_receive_queue.lock);
3808 memcpy(&st, &po->stats, sizeof(st));
3809 memset(&po->stats, 0, sizeof(po->stats));
3810 spin_unlock_bh(&sk->sk_receive_queue.lock);
3812 if (po->tp_version == TPACKET_V3) {
3813 lv = sizeof(struct tpacket_stats_v3);
3814 st.stats3.tp_packets += st.stats3.tp_drops;
3817 lv = sizeof(struct tpacket_stats);
3818 st.stats1.tp_packets += st.stats1.tp_drops;
3823 case PACKET_AUXDATA:
3826 case PACKET_ORIGDEV:
3829 case PACKET_VNET_HDR:
3830 val = po->has_vnet_hdr;
3832 case PACKET_VERSION:
3833 val = po->tp_version;
3836 if (len > sizeof(int))
3838 if (copy_from_user(&val, optval, len))
3842 val = sizeof(struct tpacket_hdr);
3845 val = sizeof(struct tpacket2_hdr);
3848 val = sizeof(struct tpacket3_hdr);
3854 case PACKET_RESERVE:
3855 val = po->tp_reserve;
3860 case PACKET_TIMESTAMP:
3861 val = po->tp_tstamp;
3865 ((u32)po->fanout->id |
3866 ((u32)po->fanout->type << 16) |
3867 ((u32)po->fanout->flags << 24)) :
3870 case PACKET_ROLLOVER_STATS:
3873 rstats.tp_all = atomic_long_read(&po->rollover->num);
3874 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3875 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3877 lv = sizeof(rstats);
3879 case PACKET_TX_HAS_OFF:
3880 val = po->tp_tx_has_off;
3882 case PACKET_QDISC_BYPASS:
3883 val = packet_use_direct_xmit(po);
3886 return -ENOPROTOOPT;
3891 if (put_user(len, optlen))
3893 if (copy_to_user(optval, data, len))
3899 static int packet_notifier(struct notifier_block *this,
3900 unsigned long msg, void *ptr)
3903 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3904 struct net *net = dev_net(dev);
3907 sk_for_each_rcu(sk, &net->packet.sklist) {
3908 struct packet_sock *po = pkt_sk(sk);
3911 case NETDEV_UNREGISTER:
3913 packet_dev_mclist_delete(dev, &po->mclist);
3917 if (dev->ifindex == po->ifindex) {
3918 spin_lock(&po->bind_lock);
3920 __unregister_prot_hook(sk, false);
3921 sk->sk_err = ENETDOWN;
3922 if (!sock_flag(sk, SOCK_DEAD))
3923 sk->sk_error_report(sk);
3925 if (msg == NETDEV_UNREGISTER) {
3926 packet_cached_dev_reset(po);
3928 if (po->prot_hook.dev)
3929 dev_put(po->prot_hook.dev);
3930 po->prot_hook.dev = NULL;
3932 spin_unlock(&po->bind_lock);
3936 if (dev->ifindex == po->ifindex) {
3937 spin_lock(&po->bind_lock);
3939 register_prot_hook(sk);
3940 spin_unlock(&po->bind_lock);
3950 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3953 struct sock *sk = sock->sk;
3958 int amount = sk_wmem_alloc_get(sk);
3960 return put_user(amount, (int __user *)arg);
3964 struct sk_buff *skb;
3967 spin_lock_bh(&sk->sk_receive_queue.lock);
3968 skb = skb_peek(&sk->sk_receive_queue);
3971 spin_unlock_bh(&sk->sk_receive_queue.lock);
3972 return put_user(amount, (int __user *)arg);
3975 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3977 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3987 case SIOCGIFBRDADDR:
3988 case SIOCSIFBRDADDR:
3989 case SIOCGIFNETMASK:
3990 case SIOCSIFNETMASK:
3991 case SIOCGIFDSTADDR:
3992 case SIOCSIFDSTADDR:
3994 return inet_dgram_ops.ioctl(sock, cmd, arg);
3998 return -ENOIOCTLCMD;
4003 static unsigned int packet_poll(struct file *file, struct socket *sock,
4006 struct sock *sk = sock->sk;
4007 struct packet_sock *po = pkt_sk(sk);
4008 unsigned int mask = datagram_poll(file, sock, wait);
4010 spin_lock_bh(&sk->sk_receive_queue.lock);
4011 if (po->rx_ring.pg_vec) {
4012 if (!packet_previous_rx_frame(po, &po->rx_ring,
4014 mask |= POLLIN | POLLRDNORM;
4016 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
4018 spin_unlock_bh(&sk->sk_receive_queue.lock);
4019 spin_lock_bh(&sk->sk_write_queue.lock);
4020 if (po->tx_ring.pg_vec) {
4021 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4022 mask |= POLLOUT | POLLWRNORM;
4024 spin_unlock_bh(&sk->sk_write_queue.lock);
4029 /* Dirty? Well, I still did not learn better way to account
4033 static void packet_mm_open(struct vm_area_struct *vma)
4035 struct file *file = vma->vm_file;
4036 struct socket *sock = file->private_data;
4037 struct sock *sk = sock->sk;
4040 atomic_inc(&pkt_sk(sk)->mapped);
4043 static void packet_mm_close(struct vm_area_struct *vma)
4045 struct file *file = vma->vm_file;
4046 struct socket *sock = file->private_data;
4047 struct sock *sk = sock->sk;
4050 atomic_dec(&pkt_sk(sk)->mapped);
4053 static const struct vm_operations_struct packet_mmap_ops = {
4054 .open = packet_mm_open,
4055 .close = packet_mm_close,
4058 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4063 for (i = 0; i < len; i++) {
4064 if (likely(pg_vec[i].buffer)) {
4065 if (is_vmalloc_addr(pg_vec[i].buffer))
4066 vfree(pg_vec[i].buffer);
4068 free_pages((unsigned long)pg_vec[i].buffer,
4070 pg_vec[i].buffer = NULL;
4076 static char *alloc_one_pg_vec_page(unsigned long order)
4079 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4080 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4082 buffer = (char *) __get_free_pages(gfp_flags, order);
4086 /* __get_free_pages failed, fall back to vmalloc */
4087 buffer = vzalloc((1 << order) * PAGE_SIZE);
4091 /* vmalloc failed, lets dig into swap here */
4092 gfp_flags &= ~__GFP_NORETRY;
4093 buffer = (char *) __get_free_pages(gfp_flags, order);
4097 /* complete and utter failure */
4101 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4103 unsigned int block_nr = req->tp_block_nr;
4107 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4108 if (unlikely(!pg_vec))
4111 for (i = 0; i < block_nr; i++) {
4112 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4113 if (unlikely(!pg_vec[i].buffer))
4114 goto out_free_pgvec;
4121 free_pg_vec(pg_vec, order, block_nr);
4126 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4127 int closing, int tx_ring)
4129 struct pgv *pg_vec = NULL;
4130 struct packet_sock *po = pkt_sk(sk);
4131 int was_running, order = 0;
4132 struct packet_ring_buffer *rb;
4133 struct sk_buff_head *rb_queue;
4136 /* Added to avoid minimal code churn */
4137 struct tpacket_req *req = &req_u->req;
4139 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4140 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4141 WARN(1, "Tx-ring is not supported.\n");
4145 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4146 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4150 if (atomic_read(&po->mapped))
4152 if (packet_read_pending(rb))
4156 if (req->tp_block_nr) {
4157 /* Sanity tests and some calculations */
4159 if (unlikely(rb->pg_vec))
4162 switch (po->tp_version) {
4164 po->tp_hdrlen = TPACKET_HDRLEN;
4167 po->tp_hdrlen = TPACKET2_HDRLEN;
4170 po->tp_hdrlen = TPACKET3_HDRLEN;
4175 if (unlikely((int)req->tp_block_size <= 0))
4177 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4179 if (po->tp_version >= TPACKET_V3 &&
4180 (int)(req->tp_block_size -
4181 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4183 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4186 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4189 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4190 if (unlikely(rb->frames_per_block == 0))
4192 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4197 order = get_order(req->tp_block_size);
4198 pg_vec = alloc_pg_vec(req, order);
4199 if (unlikely(!pg_vec))
4201 switch (po->tp_version) {
4203 /* Transmit path is not supported. We checked
4204 * it above but just being paranoid
4207 init_prb_bdqc(po, rb, pg_vec, req_u);
4216 if (unlikely(req->tp_frame_nr))
4222 /* Detach socket from network */
4223 spin_lock(&po->bind_lock);
4224 was_running = po->running;
4228 __unregister_prot_hook(sk, false);
4230 spin_unlock(&po->bind_lock);
4235 mutex_lock(&po->pg_vec_lock);
4236 if (closing || atomic_read(&po->mapped) == 0) {
4238 spin_lock_bh(&rb_queue->lock);
4239 swap(rb->pg_vec, pg_vec);
4240 rb->frame_max = (req->tp_frame_nr - 1);
4242 rb->frame_size = req->tp_frame_size;
4243 spin_unlock_bh(&rb_queue->lock);
4245 swap(rb->pg_vec_order, order);
4246 swap(rb->pg_vec_len, req->tp_block_nr);
4248 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4249 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4250 tpacket_rcv : packet_rcv;
4251 skb_queue_purge(rb_queue);
4252 if (atomic_read(&po->mapped))
4253 pr_err("packet_mmap: vma is busy: %d\n",
4254 atomic_read(&po->mapped));
4256 mutex_unlock(&po->pg_vec_lock);
4258 spin_lock(&po->bind_lock);
4261 register_prot_hook(sk);
4263 spin_unlock(&po->bind_lock);
4264 if (closing && (po->tp_version > TPACKET_V2)) {
4265 /* Because we don't support block-based V3 on tx-ring */
4267 prb_shutdown_retire_blk_timer(po, rb_queue);
4272 free_pg_vec(pg_vec, order, req->tp_block_nr);
4277 static int packet_mmap(struct file *file, struct socket *sock,
4278 struct vm_area_struct *vma)
4280 struct sock *sk = sock->sk;
4281 struct packet_sock *po = pkt_sk(sk);
4282 unsigned long size, expected_size;
4283 struct packet_ring_buffer *rb;
4284 unsigned long start;
4291 mutex_lock(&po->pg_vec_lock);
4294 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4296 expected_size += rb->pg_vec_len
4302 if (expected_size == 0)
4305 size = vma->vm_end - vma->vm_start;
4306 if (size != expected_size)
4309 start = vma->vm_start;
4310 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4311 if (rb->pg_vec == NULL)
4314 for (i = 0; i < rb->pg_vec_len; i++) {
4316 void *kaddr = rb->pg_vec[i].buffer;
4319 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4320 page = pgv_to_page(kaddr);
4321 err = vm_insert_page(vma, start, page);
4330 atomic_inc(&po->mapped);
4331 vma->vm_ops = &packet_mmap_ops;
4335 mutex_unlock(&po->pg_vec_lock);
4339 static const struct proto_ops packet_ops_spkt = {
4340 .family = PF_PACKET,
4341 .owner = THIS_MODULE,
4342 .release = packet_release,
4343 .bind = packet_bind_spkt,
4344 .connect = sock_no_connect,
4345 .socketpair = sock_no_socketpair,
4346 .accept = sock_no_accept,
4347 .getname = packet_getname_spkt,
4348 .poll = datagram_poll,
4349 .ioctl = packet_ioctl,
4350 .listen = sock_no_listen,
4351 .shutdown = sock_no_shutdown,
4352 .setsockopt = sock_no_setsockopt,
4353 .getsockopt = sock_no_getsockopt,
4354 .sendmsg = packet_sendmsg_spkt,
4355 .recvmsg = packet_recvmsg,
4356 .mmap = sock_no_mmap,
4357 .sendpage = sock_no_sendpage,
4360 static const struct proto_ops packet_ops = {
4361 .family = PF_PACKET,
4362 .owner = THIS_MODULE,
4363 .release = packet_release,
4364 .bind = packet_bind,
4365 .connect = sock_no_connect,
4366 .socketpair = sock_no_socketpair,
4367 .accept = sock_no_accept,
4368 .getname = packet_getname,
4369 .poll = packet_poll,
4370 .ioctl = packet_ioctl,
4371 .listen = sock_no_listen,
4372 .shutdown = sock_no_shutdown,
4373 .setsockopt = packet_setsockopt,
4374 .getsockopt = packet_getsockopt,
4375 .sendmsg = packet_sendmsg,
4376 .recvmsg = packet_recvmsg,
4377 .mmap = packet_mmap,
4378 .sendpage = sock_no_sendpage,
4381 static const struct net_proto_family packet_family_ops = {
4382 .family = PF_PACKET,
4383 .create = packet_create,
4384 .owner = THIS_MODULE,
4387 static struct notifier_block packet_netdev_notifier = {
4388 .notifier_call = packet_notifier,
4391 #ifdef CONFIG_PROC_FS
4393 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4396 struct net *net = seq_file_net(seq);
4399 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4402 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4404 struct net *net = seq_file_net(seq);
4405 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4408 static void packet_seq_stop(struct seq_file *seq, void *v)
4414 static int packet_seq_show(struct seq_file *seq, void *v)
4416 if (v == SEQ_START_TOKEN)
4417 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4419 struct sock *s = sk_entry(v);
4420 const struct packet_sock *po = pkt_sk(s);
4423 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4425 atomic_read(&s->sk_refcnt),
4430 atomic_read(&s->sk_rmem_alloc),
4431 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4438 static const struct seq_operations packet_seq_ops = {
4439 .start = packet_seq_start,
4440 .next = packet_seq_next,
4441 .stop = packet_seq_stop,
4442 .show = packet_seq_show,
4445 static int packet_seq_open(struct inode *inode, struct file *file)
4447 return seq_open_net(inode, file, &packet_seq_ops,
4448 sizeof(struct seq_net_private));
4451 static const struct file_operations packet_seq_fops = {
4452 .owner = THIS_MODULE,
4453 .open = packet_seq_open,
4455 .llseek = seq_lseek,
4456 .release = seq_release_net,
4461 static int __net_init packet_net_init(struct net *net)
4463 mutex_init(&net->packet.sklist_lock);
4464 INIT_HLIST_HEAD(&net->packet.sklist);
4466 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4472 static void __net_exit packet_net_exit(struct net *net)
4474 remove_proc_entry("packet", net->proc_net);
4477 static struct pernet_operations packet_net_ops = {
4478 .init = packet_net_init,
4479 .exit = packet_net_exit,
4483 static void __exit packet_exit(void)
4485 unregister_netdevice_notifier(&packet_netdev_notifier);
4486 unregister_pernet_subsys(&packet_net_ops);
4487 sock_unregister(PF_PACKET);
4488 proto_unregister(&packet_proto);
4491 static int __init packet_init(void)
4493 int rc = proto_register(&packet_proto, 0);
4498 sock_register(&packet_family_ops);
4499 register_pernet_subsys(&packet_net_ops);
4500 register_netdevice_notifier(&packet_netdev_notifier);
4505 module_init(packet_init);
4506 module_exit(packet_exit);
4507 MODULE_LICENSE("GPL");
4508 MODULE_ALIAS_NETPROTO(PF_PACKET);