1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * PACKET - implements raw packet sockets.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 *
13 * Fixes:
14 * Alan Cox : verify_area() now used correctly
15 * Alan Cox : new skbuff lists, look ma no backlogs!
16 * Alan Cox : tidied skbuff lists.
17 * Alan Cox : Now uses generic datagram routines I
18 * added. Also fixed the peek/read crash
19 * from all old Linux datagram code.
20 * Alan Cox : Uses the improved datagram code.
21 * Alan Cox : Added NULL's for socket options.
22 * Alan Cox : Re-commented the code.
23 * Alan Cox : Use new kernel side addressing
24 * Rob Janssen : Correct MTU usage.
25 * Dave Platt : Counter leaks caused by incorrect
26 * interrupt locking and some slightly
27 * dubious gcc output. Can you read
28 * compiler: it said _VOLATILE_
29 * Richard Kooijman : Timestamp fixes.
30 * Alan Cox : New buffers. Use sk->mac.raw.
31 * Alan Cox : sendmsg/recvmsg support.
32 * Alan Cox : Protocol setting support
33 * Alexey Kuznetsov : Untied from IPv4 stack.
34 * Cyrus Durgin : Fixed kerneld for kmod.
35 * Michal Ostrowski : Module initialization cleanup.
36 * Ulises Alonso : Frame number limit removal and
37 * packet_set_ring memory leak.
38 * Eric Biederman : Allow for > 8 byte hardware addresses.
39 * The convention is that longer addresses
40 * will simply extend the hardware address
41 * byte arrays at the end of sockaddr_ll
42 * and packet_mreq.
43 * Johann Baudy : Added TX RING.
44 * Chetan Loke : Implemented TPACKET_V3 block abstraction
45 * layer.
46 * Copyright (C) 2011, <lokec@ccs.neu.edu>
47 */
48
49 #include <linux/types.h>
50 #include <linux/mm.h>
51 #include <linux/capability.h>
52 #include <linux/fcntl.h>
53 #include <linux/socket.h>
54 #include <linux/in.h>
55 #include <linux/inet.h>
56 #include <linux/netdevice.h>
57 #include <linux/if_packet.h>
58 #include <linux/wireless.h>
59 #include <linux/kernel.h>
60 #include <linux/kmod.h>
61 #include <linux/slab.h>
62 #include <linux/vmalloc.h>
63 #include <net/net_namespace.h>
64 #include <net/ip.h>
65 #include <net/protocol.h>
66 #include <linux/skbuff.h>
67 #include <net/sock.h>
68 #include <linux/errno.h>
69 #include <linux/timer.h>
70 #include <linux/uaccess.h>
71 #include <asm/ioctls.h>
72 #include <asm/page.h>
73 #include <asm/cacheflush.h>
74 #include <asm/io.h>
75 #include <linux/proc_fs.h>
76 #include <linux/seq_file.h>
77 #include <linux/poll.h>
78 #include <linux/module.h>
79 #include <linux/init.h>
80 #include <linux/mutex.h>
81 #include <linux/if_vlan.h>
82 #include <linux/virtio_net.h>
83 #include <linux/errqueue.h>
84 #include <linux/net_tstamp.h>
85 #include <linux/percpu.h>
86 #ifdef CONFIG_INET
87 #include <net/inet_common.h>
88 #endif
89 #include <linux/bpf.h>
90 #include <net/compat.h>
91
92 #include "internal.h"
93
94 /*
95 Assumptions:
96 - If the device has no dev->header_ops->create, there is no LL header
97 visible above the device. In this case, its hard_header_len should be 0.
98 The device may prepend its own header internally. In this case, its
99 needed_headroom should be set to the space needed for it to add its
100 internal header.
101 For example, a WiFi driver pretending to be an Ethernet driver should
102 set its hard_header_len to be the Ethernet header length, and set its
103 needed_headroom to be (the real WiFi header length - the fake Ethernet
104 header length).
105 - packet socket receives packets with pulled ll header,
106 so that SOCK_RAW should push it back.
107
108 On receive:
109 -----------
110
111 Incoming, dev_has_header(dev) == true
112 mac_header -> ll header
113 data -> data
114
115 Outgoing, dev_has_header(dev) == true
116 mac_header -> ll header
117 data -> ll header
118
119 Incoming, dev_has_header(dev) == false
120 mac_header -> data
121 However drivers often make it point to the ll header.
122 This is incorrect because the ll header should be invisible to us.
123 data -> data
124
125 Outgoing, dev_has_header(dev) == false
126 mac_header -> data. ll header is invisible to us.
127 data -> data
128
129 Resume
130 If dev_has_header(dev) == false we are unable to restore the ll header,
131 because it is invisible to us.
132
133
134 On transmit:
135 ------------
136
137 dev->header_ops != NULL
138 mac_header -> ll header
139 data -> ll header
140
141 dev->header_ops == NULL (ll header is invisible to us)
142 mac_header -> data
143 data -> data
144
145 We should set network_header on output to the correct position,
146 packet classifier depends on it.
147 */
148
149 /* Private packet socket structures. */
150
151 /* identical to struct packet_mreq except it has
152 * a longer address field.
153 */
154 struct packet_mreq_max {
155 int mr_ifindex;
156 unsigned short mr_type;
157 unsigned short mr_alen;
158 unsigned char mr_address[MAX_ADDR_LEN];
159 };
160
161 union tpacket_uhdr {
162 struct tpacket_hdr *h1;
163 struct tpacket2_hdr *h2;
164 struct tpacket3_hdr *h3;
165 void *raw;
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169 int closing, int tx_ring);
170
171 #define V3_ALIGNMENT (8)
172
173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
179 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
180 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
181 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
182 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
183 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
184
185 struct packet_sock;
186 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
187 struct packet_type *pt, struct net_device *orig_dev);
188
189 static void *packet_previous_frame(struct packet_sock *po,
190 struct packet_ring_buffer *rb,
191 int status);
192 static void packet_increment_head(struct packet_ring_buffer *buff);
193 static int prb_curr_blk_in_use(struct tpacket_block_desc *);
194 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
195 struct packet_sock *);
196 static void prb_retire_current_block(struct tpacket_kbdq_core *,
197 struct packet_sock *, unsigned int status);
198 static int prb_queue_frozen(struct tpacket_kbdq_core *);
199 static void prb_open_block(struct tpacket_kbdq_core *,
200 struct tpacket_block_desc *);
201 static void prb_retire_rx_blk_timer_expired(struct timer_list *);
202 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
203 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
204 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
205 struct tpacket3_hdr *);
206 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
207 struct tpacket3_hdr *);
208 static void packet_flush_mclist(struct sock *sk);
209 static u16 packet_pick_tx_queue(struct sk_buff *skb);
210
211 struct packet_skb_cb {
212 union {
213 struct sockaddr_pkt pkt;
214 union {
215 /* Trick: alias skb original length with
216 * ll.sll_family and ll.protocol in order
217 * to save room.
218 */
219 unsigned int origlen;
220 struct sockaddr_ll ll;
221 };
222 } sa;
223 };
224
225 #define vio_le() virtio_legacy_is_little_endian()
226
227 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
228
229 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
230 #define GET_PBLOCK_DESC(x, bid) \
231 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
232 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
233 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
234 #define GET_NEXT_PRB_BLK_NUM(x) \
235 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
236 ((x)->kactive_blk_num+1) : 0)
237
238 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
239 static void __fanout_link(struct sock *sk, struct packet_sock *po);
240
packet_direct_xmit(struct sk_buff * skb)241 static int packet_direct_xmit(struct sk_buff *skb)
242 {
243 return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
244 }
245
packet_cached_dev_get(struct packet_sock * po)246 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
247 {
248 struct net_device *dev;
249
250 rcu_read_lock();
251 dev = rcu_dereference(po->cached_dev);
252 if (likely(dev))
253 dev_hold(dev);
254 rcu_read_unlock();
255
256 return dev;
257 }
258
packet_cached_dev_assign(struct packet_sock * po,struct net_device * dev)259 static void packet_cached_dev_assign(struct packet_sock *po,
260 struct net_device *dev)
261 {
262 rcu_assign_pointer(po->cached_dev, dev);
263 }
264
packet_cached_dev_reset(struct packet_sock * po)265 static void packet_cached_dev_reset(struct packet_sock *po)
266 {
267 RCU_INIT_POINTER(po->cached_dev, NULL);
268 }
269
packet_use_direct_xmit(const struct packet_sock * po)270 static bool packet_use_direct_xmit(const struct packet_sock *po)
271 {
272 return po->xmit == packet_direct_xmit;
273 }
274
packet_pick_tx_queue(struct sk_buff * skb)275 static u16 packet_pick_tx_queue(struct sk_buff *skb)
276 {
277 struct net_device *dev = skb->dev;
278 const struct net_device_ops *ops = dev->netdev_ops;
279 int cpu = raw_smp_processor_id();
280 u16 queue_index;
281
282 #ifdef CONFIG_XPS
283 skb->sender_cpu = cpu + 1;
284 #endif
285 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
286 if (ops->ndo_select_queue) {
287 queue_index = ops->ndo_select_queue(dev, skb, NULL);
288 queue_index = netdev_cap_txqueue(dev, queue_index);
289 } else {
290 queue_index = netdev_pick_tx(dev, skb, NULL);
291 }
292
293 return queue_index;
294 }
295
296 /* __register_prot_hook must be invoked through register_prot_hook
297 * or from a context in which asynchronous accesses to the packet
298 * socket is not possible (packet_create()).
299 */
__register_prot_hook(struct sock * sk)300 static void __register_prot_hook(struct sock *sk)
301 {
302 struct packet_sock *po = pkt_sk(sk);
303
304 if (!po->running) {
305 if (po->fanout)
306 __fanout_link(sk, po);
307 else
308 dev_add_pack(&po->prot_hook);
309
310 sock_hold(sk);
311 po->running = 1;
312 }
313 }
314
register_prot_hook(struct sock * sk)315 static void register_prot_hook(struct sock *sk)
316 {
317 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
318 __register_prot_hook(sk);
319 }
320
321 /* If the sync parameter is true, we will temporarily drop
322 * the po->bind_lock and do a synchronize_net to make sure no
323 * asynchronous packet processing paths still refer to the elements
324 * of po->prot_hook. If the sync parameter is false, it is the
325 * callers responsibility to take care of this.
326 */
__unregister_prot_hook(struct sock * sk,bool sync)327 static void __unregister_prot_hook(struct sock *sk, bool sync)
328 {
329 struct packet_sock *po = pkt_sk(sk);
330
331 lockdep_assert_held_once(&po->bind_lock);
332
333 po->running = 0;
334
335 if (po->fanout)
336 __fanout_unlink(sk, po);
337 else
338 __dev_remove_pack(&po->prot_hook);
339
340 __sock_put(sk);
341
342 if (sync) {
343 spin_unlock(&po->bind_lock);
344 synchronize_net();
345 spin_lock(&po->bind_lock);
346 }
347 }
348
unregister_prot_hook(struct sock * sk,bool sync)349 static void unregister_prot_hook(struct sock *sk, bool sync)
350 {
351 struct packet_sock *po = pkt_sk(sk);
352
353 if (po->running)
354 __unregister_prot_hook(sk, sync);
355 }
356
pgv_to_page(void * addr)357 static inline struct page * __pure pgv_to_page(void *addr)
358 {
359 if (is_vmalloc_addr(addr))
360 return vmalloc_to_page(addr);
361 return virt_to_page(addr);
362 }
363
__packet_set_status(struct packet_sock * po,void * frame,int status)364 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
365 {
366 union tpacket_uhdr h;
367
368 h.raw = frame;
369 switch (po->tp_version) {
370 case TPACKET_V1:
371 h.h1->tp_status = status;
372 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
373 break;
374 case TPACKET_V2:
375 h.h2->tp_status = status;
376 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
377 break;
378 case TPACKET_V3:
379 h.h3->tp_status = status;
380 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
381 break;
382 default:
383 WARN(1, "TPACKET version not supported.\n");
384 BUG();
385 }
386
387 smp_wmb();
388 }
389
__packet_get_status(const struct packet_sock * po,void * frame)390 static int __packet_get_status(const struct packet_sock *po, void *frame)
391 {
392 union tpacket_uhdr h;
393
394 smp_rmb();
395
396 h.raw = frame;
397 switch (po->tp_version) {
398 case TPACKET_V1:
399 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
400 return h.h1->tp_status;
401 case TPACKET_V2:
402 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
403 return h.h2->tp_status;
404 case TPACKET_V3:
405 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
406 return h.h3->tp_status;
407 default:
408 WARN(1, "TPACKET version not supported.\n");
409 BUG();
410 return 0;
411 }
412 }
413
tpacket_get_timestamp(struct sk_buff * skb,struct timespec64 * ts,unsigned int flags)414 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
415 unsigned int flags)
416 {
417 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
418
419 if (shhwtstamps &&
420 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
421 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
422 return TP_STATUS_TS_RAW_HARDWARE;
423
424 if ((flags & SOF_TIMESTAMPING_SOFTWARE) &&
425 ktime_to_timespec64_cond(skb->tstamp, ts))
426 return TP_STATUS_TS_SOFTWARE;
427
428 return 0;
429 }
430
__packet_set_timestamp(struct packet_sock * po,void * frame,struct sk_buff * skb)431 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
432 struct sk_buff *skb)
433 {
434 union tpacket_uhdr h;
435 struct timespec64 ts;
436 __u32 ts_status;
437
438 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
439 return 0;
440
441 h.raw = frame;
442 /*
443 * versions 1 through 3 overflow the timestamps in y2106, since they
444 * all store the seconds in a 32-bit unsigned integer.
445 * If we create a version 4, that should have a 64-bit timestamp,
446 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
447 * nanoseconds.
448 */
449 switch (po->tp_version) {
450 case TPACKET_V1:
451 h.h1->tp_sec = ts.tv_sec;
452 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
453 break;
454 case TPACKET_V2:
455 h.h2->tp_sec = ts.tv_sec;
456 h.h2->tp_nsec = ts.tv_nsec;
457 break;
458 case TPACKET_V3:
459 h.h3->tp_sec = ts.tv_sec;
460 h.h3->tp_nsec = ts.tv_nsec;
461 break;
462 default:
463 WARN(1, "TPACKET version not supported.\n");
464 BUG();
465 }
466
467 /* one flush is safe, as both fields always lie on the same cacheline */
468 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
469 smp_wmb();
470
471 return ts_status;
472 }
473
packet_lookup_frame(const struct packet_sock * po,const struct packet_ring_buffer * rb,unsigned int position,int status)474 static void *packet_lookup_frame(const struct packet_sock *po,
475 const struct packet_ring_buffer *rb,
476 unsigned int position,
477 int status)
478 {
479 unsigned int pg_vec_pos, frame_offset;
480 union tpacket_uhdr h;
481
482 pg_vec_pos = position / rb->frames_per_block;
483 frame_offset = position % rb->frames_per_block;
484
485 h.raw = rb->pg_vec[pg_vec_pos].buffer +
486 (frame_offset * rb->frame_size);
487
488 if (status != __packet_get_status(po, h.raw))
489 return NULL;
490
491 return h.raw;
492 }
493
packet_current_frame(struct packet_sock * po,struct packet_ring_buffer * rb,int status)494 static void *packet_current_frame(struct packet_sock *po,
495 struct packet_ring_buffer *rb,
496 int status)
497 {
498 return packet_lookup_frame(po, rb, rb->head, status);
499 }
500
prb_del_retire_blk_timer(struct tpacket_kbdq_core * pkc)501 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
502 {
503 del_timer_sync(&pkc->retire_blk_timer);
504 }
505
prb_shutdown_retire_blk_timer(struct packet_sock * po,struct sk_buff_head * rb_queue)506 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
507 struct sk_buff_head *rb_queue)
508 {
509 struct tpacket_kbdq_core *pkc;
510
511 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
512
513 spin_lock_bh(&rb_queue->lock);
514 pkc->delete_blk_timer = 1;
515 spin_unlock_bh(&rb_queue->lock);
516
517 prb_del_retire_blk_timer(pkc);
518 }
519
prb_setup_retire_blk_timer(struct packet_sock * po)520 static void prb_setup_retire_blk_timer(struct packet_sock *po)
521 {
522 struct tpacket_kbdq_core *pkc;
523
524 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
525 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
526 0);
527 pkc->retire_blk_timer.expires = jiffies;
528 }
529
prb_calc_retire_blk_tmo(struct packet_sock * po,int blk_size_in_bytes)530 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
531 int blk_size_in_bytes)
532 {
533 struct net_device *dev;
534 unsigned int mbits, div;
535 struct ethtool_link_ksettings ecmd;
536 int err;
537
538 rtnl_lock();
539 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
540 if (unlikely(!dev)) {
541 rtnl_unlock();
542 return DEFAULT_PRB_RETIRE_TOV;
543 }
544 err = __ethtool_get_link_ksettings(dev, &ecmd);
545 rtnl_unlock();
546 if (err)
547 return DEFAULT_PRB_RETIRE_TOV;
548
549 /* If the link speed is so slow you don't really
550 * need to worry about perf anyways
551 */
552 if (ecmd.base.speed < SPEED_1000 ||
553 ecmd.base.speed == SPEED_UNKNOWN)
554 return DEFAULT_PRB_RETIRE_TOV;
555
556 div = ecmd.base.speed / 1000;
557 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
558
559 if (div)
560 mbits /= div;
561
562 if (div)
563 return mbits + 1;
564 return mbits;
565 }
566
prb_init_ft_ops(struct tpacket_kbdq_core * p1,union tpacket_req_u * req_u)567 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
568 union tpacket_req_u *req_u)
569 {
570 p1->feature_req_word = req_u->req3.tp_feature_req_word;
571 }
572
init_prb_bdqc(struct packet_sock * po,struct packet_ring_buffer * rb,struct pgv * pg_vec,union tpacket_req_u * req_u)573 static void init_prb_bdqc(struct packet_sock *po,
574 struct packet_ring_buffer *rb,
575 struct pgv *pg_vec,
576 union tpacket_req_u *req_u)
577 {
578 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
579 struct tpacket_block_desc *pbd;
580
581 memset(p1, 0x0, sizeof(*p1));
582
583 p1->knxt_seq_num = 1;
584 p1->pkbdq = pg_vec;
585 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
586 p1->pkblk_start = pg_vec[0].buffer;
587 p1->kblk_size = req_u->req3.tp_block_size;
588 p1->knum_blocks = req_u->req3.tp_block_nr;
589 p1->hdrlen = po->tp_hdrlen;
590 p1->version = po->tp_version;
591 p1->last_kactive_blk_num = 0;
592 po->stats.stats3.tp_freeze_q_cnt = 0;
593 if (req_u->req3.tp_retire_blk_tov)
594 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
595 else
596 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
597 req_u->req3.tp_block_size);
598 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
599 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
600 rwlock_init(&p1->blk_fill_in_prog_lock);
601
602 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
603 prb_init_ft_ops(p1, req_u);
604 prb_setup_retire_blk_timer(po);
605 prb_open_block(p1, pbd);
606 }
607
608 /* Do NOT update the last_blk_num first.
609 * Assumes sk_buff_head lock is held.
610 */
_prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core * pkc)611 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
612 {
613 mod_timer(&pkc->retire_blk_timer,
614 jiffies + pkc->tov_in_jiffies);
615 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
616 }
617
618 /*
619 * Timer logic:
620 * 1) We refresh the timer only when we open a block.
621 * By doing this we don't waste cycles refreshing the timer
622 * on packet-by-packet basis.
623 *
624 * With a 1MB block-size, on a 1Gbps line, it will take
625 * i) ~8 ms to fill a block + ii) memcpy etc.
626 * In this cut we are not accounting for the memcpy time.
627 *
628 * So, if the user sets the 'tmo' to 10ms then the timer
629 * will never fire while the block is still getting filled
630 * (which is what we want). However, the user could choose
631 * to close a block early and that's fine.
632 *
633 * But when the timer does fire, we check whether or not to refresh it.
634 * Since the tmo granularity is in msecs, it is not too expensive
635 * to refresh the timer, lets say every '8' msecs.
636 * Either the user can set the 'tmo' or we can derive it based on
637 * a) line-speed and b) block-size.
638 * prb_calc_retire_blk_tmo() calculates the tmo.
639 *
640 */
prb_retire_rx_blk_timer_expired(struct timer_list * t)641 static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
642 {
643 struct packet_sock *po =
644 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
645 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
646 unsigned int frozen;
647 struct tpacket_block_desc *pbd;
648
649 spin_lock(&po->sk.sk_receive_queue.lock);
650
651 frozen = prb_queue_frozen(pkc);
652 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
653
654 if (unlikely(pkc->delete_blk_timer))
655 goto out;
656
657 /* We only need to plug the race when the block is partially filled.
658 * tpacket_rcv:
659 * lock(); increment BLOCK_NUM_PKTS; unlock()
660 * copy_bits() is in progress ...
661 * timer fires on other cpu:
662 * we can't retire the current block because copy_bits
663 * is in progress.
664 *
665 */
666 if (BLOCK_NUM_PKTS(pbd)) {
667 /* Waiting for skb_copy_bits to finish... */
668 write_lock(&pkc->blk_fill_in_prog_lock);
669 write_unlock(&pkc->blk_fill_in_prog_lock);
670 }
671
672 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
673 if (!frozen) {
674 if (!BLOCK_NUM_PKTS(pbd)) {
675 /* An empty block. Just refresh the timer. */
676 goto refresh_timer;
677 }
678 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
679 if (!prb_dispatch_next_block(pkc, po))
680 goto refresh_timer;
681 else
682 goto out;
683 } else {
684 /* Case 1. Queue was frozen because user-space was
685 * lagging behind.
686 */
687 if (prb_curr_blk_in_use(pbd)) {
688 /*
689 * Ok, user-space is still behind.
690 * So just refresh the timer.
691 */
692 goto refresh_timer;
693 } else {
694 /* Case 2. queue was frozen,user-space caught up,
695 * now the link went idle && the timer fired.
696 * We don't have a block to close.So we open this
697 * block and restart the timer.
698 * opening a block thaws the queue,restarts timer
699 * Thawing/timer-refresh is a side effect.
700 */
701 prb_open_block(pkc, pbd);
702 goto out;
703 }
704 }
705 }
706
707 refresh_timer:
708 _prb_refresh_rx_retire_blk_timer(pkc);
709
710 out:
711 spin_unlock(&po->sk.sk_receive_queue.lock);
712 }
713
prb_flush_block(struct tpacket_kbdq_core * pkc1,struct tpacket_block_desc * pbd1,__u32 status)714 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
715 struct tpacket_block_desc *pbd1, __u32 status)
716 {
717 /* Flush everything minus the block header */
718
719 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
720 u8 *start, *end;
721
722 start = (u8 *)pbd1;
723
724 /* Skip the block header(we know header WILL fit in 4K) */
725 start += PAGE_SIZE;
726
727 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
728 for (; start < end; start += PAGE_SIZE)
729 flush_dcache_page(pgv_to_page(start));
730
731 smp_wmb();
732 #endif
733
734 /* Now update the block status. */
735
736 BLOCK_STATUS(pbd1) = status;
737
738 /* Flush the block header */
739
740 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
741 start = (u8 *)pbd1;
742 flush_dcache_page(pgv_to_page(start));
743
744 smp_wmb();
745 #endif
746 }
747
748 /*
749 * Side effect:
750 *
751 * 1) flush the block
752 * 2) Increment active_blk_num
753 *
754 * Note:We DONT refresh the timer on purpose.
755 * Because almost always the next block will be opened.
756 */
prb_close_block(struct tpacket_kbdq_core * pkc1,struct tpacket_block_desc * pbd1,struct packet_sock * po,unsigned int stat)757 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
758 struct tpacket_block_desc *pbd1,
759 struct packet_sock *po, unsigned int stat)
760 {
761 __u32 status = TP_STATUS_USER | stat;
762
763 struct tpacket3_hdr *last_pkt;
764 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
765 struct sock *sk = &po->sk;
766
767 if (atomic_read(&po->tp_drops))
768 status |= TP_STATUS_LOSING;
769
770 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
771 last_pkt->tp_next_offset = 0;
772
773 /* Get the ts of the last pkt */
774 if (BLOCK_NUM_PKTS(pbd1)) {
775 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
776 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
777 } else {
778 /* Ok, we tmo'd - so get the current time.
779 *
780 * It shouldn't really happen as we don't close empty
781 * blocks. See prb_retire_rx_blk_timer_expired().
782 */
783 struct timespec64 ts;
784 ktime_get_real_ts64(&ts);
785 h1->ts_last_pkt.ts_sec = ts.tv_sec;
786 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
787 }
788
789 smp_wmb();
790
791 /* Flush the block */
792 prb_flush_block(pkc1, pbd1, status);
793
794 sk->sk_data_ready(sk);
795
796 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
797 }
798
prb_thaw_queue(struct tpacket_kbdq_core * pkc)799 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
800 {
801 pkc->reset_pending_on_curr_blk = 0;
802 }
803
804 /*
805 * Side effect of opening a block:
806 *
807 * 1) prb_queue is thawed.
808 * 2) retire_blk_timer is refreshed.
809 *
810 */
prb_open_block(struct tpacket_kbdq_core * pkc1,struct tpacket_block_desc * pbd1)811 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
812 struct tpacket_block_desc *pbd1)
813 {
814 struct timespec64 ts;
815 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
816
817 smp_rmb();
818
819 /* We could have just memset this but we will lose the
820 * flexibility of making the priv area sticky
821 */
822
823 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
824 BLOCK_NUM_PKTS(pbd1) = 0;
825 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
826
827 ktime_get_real_ts64(&ts);
828
829 h1->ts_first_pkt.ts_sec = ts.tv_sec;
830 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
831
832 pkc1->pkblk_start = (char *)pbd1;
833 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
834
835 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
836 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
837
838 pbd1->version = pkc1->version;
839 pkc1->prev = pkc1->nxt_offset;
840 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
841
842 prb_thaw_queue(pkc1);
843 _prb_refresh_rx_retire_blk_timer(pkc1);
844
845 smp_wmb();
846 }
847
848 /*
849 * Queue freeze logic:
850 * 1) Assume tp_block_nr = 8 blocks.
851 * 2) At time 't0', user opens Rx ring.
852 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
853 * 4) user-space is either sleeping or processing block '0'.
854 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
855 * it will close block-7,loop around and try to fill block '0'.
856 * call-flow:
857 * __packet_lookup_frame_in_block
858 * prb_retire_current_block()
859 * prb_dispatch_next_block()
860 * |->(BLOCK_STATUS == USER) evaluates to true
861 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
862 * 6) Now there are two cases:
863 * 6.1) Link goes idle right after the queue is frozen.
864 * But remember, the last open_block() refreshed the timer.
865 * When this timer expires,it will refresh itself so that we can
866 * re-open block-0 in near future.
867 * 6.2) Link is busy and keeps on receiving packets. This is a simple
868 * case and __packet_lookup_frame_in_block will check if block-0
869 * is free and can now be re-used.
870 */
prb_freeze_queue(struct tpacket_kbdq_core * pkc,struct packet_sock * po)871 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
872 struct packet_sock *po)
873 {
874 pkc->reset_pending_on_curr_blk = 1;
875 po->stats.stats3.tp_freeze_q_cnt++;
876 }
877
878 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
879
880 /*
881 * If the next block is free then we will dispatch it
882 * and return a good offset.
883 * Else, we will freeze the queue.
884 * So, caller must check the return value.
885 */
prb_dispatch_next_block(struct tpacket_kbdq_core * pkc,struct packet_sock * po)886 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
887 struct packet_sock *po)
888 {
889 struct tpacket_block_desc *pbd;
890
891 smp_rmb();
892
893 /* 1. Get current block num */
894 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
895
896 /* 2. If this block is currently in_use then freeze the queue */
897 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
898 prb_freeze_queue(pkc, po);
899 return NULL;
900 }
901
902 /*
903 * 3.
904 * open this block and return the offset where the first packet
905 * needs to get stored.
906 */
907 prb_open_block(pkc, pbd);
908 return (void *)pkc->nxt_offset;
909 }
910
prb_retire_current_block(struct tpacket_kbdq_core * pkc,struct packet_sock * po,unsigned int status)911 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
912 struct packet_sock *po, unsigned int status)
913 {
914 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
915
916 /* retire/close the current block */
917 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
918 /*
919 * Plug the case where copy_bits() is in progress on
920 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
921 * have space to copy the pkt in the current block and
922 * called prb_retire_current_block()
923 *
924 * We don't need to worry about the TMO case because
925 * the timer-handler already handled this case.
926 */
927 if (!(status & TP_STATUS_BLK_TMO)) {
928 /* Waiting for skb_copy_bits to finish... */
929 write_lock(&pkc->blk_fill_in_prog_lock);
930 write_unlock(&pkc->blk_fill_in_prog_lock);
931 }
932 prb_close_block(pkc, pbd, po, status);
933 return;
934 }
935 }
936
prb_curr_blk_in_use(struct tpacket_block_desc * pbd)937 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
938 {
939 return TP_STATUS_USER & BLOCK_STATUS(pbd);
940 }
941
prb_queue_frozen(struct tpacket_kbdq_core * pkc)942 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
943 {
944 return pkc->reset_pending_on_curr_blk;
945 }
946
prb_clear_blk_fill_status(struct packet_ring_buffer * rb)947 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
948 __releases(&pkc->blk_fill_in_prog_lock)
949 {
950 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
951
952 read_unlock(&pkc->blk_fill_in_prog_lock);
953 }
954
prb_fill_rxhash(struct tpacket_kbdq_core * pkc,struct tpacket3_hdr * ppd)955 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
956 struct tpacket3_hdr *ppd)
957 {
958 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
959 }
960
prb_clear_rxhash(struct tpacket_kbdq_core * pkc,struct tpacket3_hdr * ppd)961 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
962 struct tpacket3_hdr *ppd)
963 {
964 ppd->hv1.tp_rxhash = 0;
965 }
966
prb_fill_vlan_info(struct tpacket_kbdq_core * pkc,struct tpacket3_hdr * ppd)967 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
968 struct tpacket3_hdr *ppd)
969 {
970 if (skb_vlan_tag_present(pkc->skb)) {
971 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
972 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
973 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
974 } else {
975 ppd->hv1.tp_vlan_tci = 0;
976 ppd->hv1.tp_vlan_tpid = 0;
977 ppd->tp_status = TP_STATUS_AVAILABLE;
978 }
979 }
980
prb_run_all_ft_ops(struct tpacket_kbdq_core * pkc,struct tpacket3_hdr * ppd)981 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
982 struct tpacket3_hdr *ppd)
983 {
984 ppd->hv1.tp_padding = 0;
985 prb_fill_vlan_info(pkc, ppd);
986
987 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
988 prb_fill_rxhash(pkc, ppd);
989 else
990 prb_clear_rxhash(pkc, ppd);
991 }
992
prb_fill_curr_block(char * curr,struct tpacket_kbdq_core * pkc,struct tpacket_block_desc * pbd,unsigned int len)993 static void prb_fill_curr_block(char *curr,
994 struct tpacket_kbdq_core *pkc,
995 struct tpacket_block_desc *pbd,
996 unsigned int len)
997 __acquires(&pkc->blk_fill_in_prog_lock)
998 {
999 struct tpacket3_hdr *ppd;
1000
1001 ppd = (struct tpacket3_hdr *)curr;
1002 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1003 pkc->prev = curr;
1004 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1005 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1006 BLOCK_NUM_PKTS(pbd) += 1;
1007 read_lock(&pkc->blk_fill_in_prog_lock);
1008 prb_run_all_ft_ops(pkc, ppd);
1009 }
1010
1011 /* Assumes caller has the sk->rx_queue.lock */
__packet_lookup_frame_in_block(struct packet_sock * po,struct sk_buff * skb,unsigned int len)1012 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1013 struct sk_buff *skb,
1014 unsigned int len
1015 )
1016 {
1017 struct tpacket_kbdq_core *pkc;
1018 struct tpacket_block_desc *pbd;
1019 char *curr, *end;
1020
1021 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1022 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1023
1024 /* Queue is frozen when user space is lagging behind */
1025 if (prb_queue_frozen(pkc)) {
1026 /*
1027 * Check if that last block which caused the queue to freeze,
1028 * is still in_use by user-space.
1029 */
1030 if (prb_curr_blk_in_use(pbd)) {
1031 /* Can't record this packet */
1032 return NULL;
1033 } else {
1034 /*
1035 * Ok, the block was released by user-space.
1036 * Now let's open that block.
1037 * opening a block also thaws the queue.
1038 * Thawing is a side effect.
1039 */
1040 prb_open_block(pkc, pbd);
1041 }
1042 }
1043
1044 smp_mb();
1045 curr = pkc->nxt_offset;
1046 pkc->skb = skb;
1047 end = (char *)pbd + pkc->kblk_size;
1048
1049 /* first try the current block */
1050 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1051 prb_fill_curr_block(curr, pkc, pbd, len);
1052 return (void *)curr;
1053 }
1054
1055 /* Ok, close the current block */
1056 prb_retire_current_block(pkc, po, 0);
1057
1058 /* Now, try to dispatch the next block */
1059 curr = (char *)prb_dispatch_next_block(pkc, po);
1060 if (curr) {
1061 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1062 prb_fill_curr_block(curr, pkc, pbd, len);
1063 return (void *)curr;
1064 }
1065
1066 /*
1067 * No free blocks are available.user_space hasn't caught up yet.
1068 * Queue was just frozen and now this packet will get dropped.
1069 */
1070 return NULL;
1071 }
1072
packet_current_rx_frame(struct packet_sock * po,struct sk_buff * skb,int status,unsigned int len)1073 static void *packet_current_rx_frame(struct packet_sock *po,
1074 struct sk_buff *skb,
1075 int status, unsigned int len)
1076 {
1077 char *curr = NULL;
1078 switch (po->tp_version) {
1079 case TPACKET_V1:
1080 case TPACKET_V2:
1081 curr = packet_lookup_frame(po, &po->rx_ring,
1082 po->rx_ring.head, status);
1083 return curr;
1084 case TPACKET_V3:
1085 return __packet_lookup_frame_in_block(po, skb, len);
1086 default:
1087 WARN(1, "TPACKET version not supported\n");
1088 BUG();
1089 return NULL;
1090 }
1091 }
1092
prb_lookup_block(const struct packet_sock * po,const struct packet_ring_buffer * rb,unsigned int idx,int status)1093 static void *prb_lookup_block(const struct packet_sock *po,
1094 const struct packet_ring_buffer *rb,
1095 unsigned int idx,
1096 int status)
1097 {
1098 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1099 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1100
1101 if (status != BLOCK_STATUS(pbd))
1102 return NULL;
1103 return pbd;
1104 }
1105
prb_previous_blk_num(struct packet_ring_buffer * rb)1106 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1107 {
1108 unsigned int prev;
1109 if (rb->prb_bdqc.kactive_blk_num)
1110 prev = rb->prb_bdqc.kactive_blk_num-1;
1111 else
1112 prev = rb->prb_bdqc.knum_blocks-1;
1113 return prev;
1114 }
1115
1116 /* Assumes caller has held the rx_queue.lock */
__prb_previous_block(struct packet_sock * po,struct packet_ring_buffer * rb,int status)1117 static void *__prb_previous_block(struct packet_sock *po,
1118 struct packet_ring_buffer *rb,
1119 int status)
1120 {
1121 unsigned int previous = prb_previous_blk_num(rb);
1122 return prb_lookup_block(po, rb, previous, status);
1123 }
1124
packet_previous_rx_frame(struct packet_sock * po,struct packet_ring_buffer * rb,int status)1125 static void *packet_previous_rx_frame(struct packet_sock *po,
1126 struct packet_ring_buffer *rb,
1127 int status)
1128 {
1129 if (po->tp_version <= TPACKET_V2)
1130 return packet_previous_frame(po, rb, status);
1131
1132 return __prb_previous_block(po, rb, status);
1133 }
1134
packet_increment_rx_head(struct packet_sock * po,struct packet_ring_buffer * rb)1135 static void packet_increment_rx_head(struct packet_sock *po,
1136 struct packet_ring_buffer *rb)
1137 {
1138 switch (po->tp_version) {
1139 case TPACKET_V1:
1140 case TPACKET_V2:
1141 return packet_increment_head(rb);
1142 case TPACKET_V3:
1143 default:
1144 WARN(1, "TPACKET version not supported.\n");
1145 BUG();
1146 return;
1147 }
1148 }
1149
packet_previous_frame(struct packet_sock * po,struct packet_ring_buffer * rb,int status)1150 static void *packet_previous_frame(struct packet_sock *po,
1151 struct packet_ring_buffer *rb,
1152 int status)
1153 {
1154 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1155 return packet_lookup_frame(po, rb, previous, status);
1156 }
1157
packet_increment_head(struct packet_ring_buffer * buff)1158 static void packet_increment_head(struct packet_ring_buffer *buff)
1159 {
1160 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1161 }
1162
packet_inc_pending(struct packet_ring_buffer * rb)1163 static void packet_inc_pending(struct packet_ring_buffer *rb)
1164 {
1165 this_cpu_inc(*rb->pending_refcnt);
1166 }
1167
packet_dec_pending(struct packet_ring_buffer * rb)1168 static void packet_dec_pending(struct packet_ring_buffer *rb)
1169 {
1170 this_cpu_dec(*rb->pending_refcnt);
1171 }
1172
packet_read_pending(const struct packet_ring_buffer * rb)1173 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1174 {
1175 unsigned int refcnt = 0;
1176 int cpu;
1177
1178 /* We don't use pending refcount in rx_ring. */
1179 if (rb->pending_refcnt == NULL)
1180 return 0;
1181
1182 for_each_possible_cpu(cpu)
1183 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1184
1185 return refcnt;
1186 }
1187
packet_alloc_pending(struct packet_sock * po)1188 static int packet_alloc_pending(struct packet_sock *po)
1189 {
1190 po->rx_ring.pending_refcnt = NULL;
1191
1192 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1193 if (unlikely(po->tx_ring.pending_refcnt == NULL))
1194 return -ENOBUFS;
1195
1196 return 0;
1197 }
1198
packet_free_pending(struct packet_sock * po)1199 static void packet_free_pending(struct packet_sock *po)
1200 {
1201 free_percpu(po->tx_ring.pending_refcnt);
1202 }
1203
1204 #define ROOM_POW_OFF 2
1205 #define ROOM_NONE 0x0
1206 #define ROOM_LOW 0x1
1207 #define ROOM_NORMAL 0x2
1208
__tpacket_has_room(const struct packet_sock * po,int pow_off)1209 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1210 {
1211 int idx, len;
1212
1213 len = READ_ONCE(po->rx_ring.frame_max) + 1;
1214 idx = READ_ONCE(po->rx_ring.head);
1215 if (pow_off)
1216 idx += len >> pow_off;
1217 if (idx >= len)
1218 idx -= len;
1219 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1220 }
1221
__tpacket_v3_has_room(const struct packet_sock * po,int pow_off)1222 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1223 {
1224 int idx, len;
1225
1226 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1227 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1228 if (pow_off)
1229 idx += len >> pow_off;
1230 if (idx >= len)
1231 idx -= len;
1232 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1233 }
1234
__packet_rcv_has_room(const struct packet_sock * po,const struct sk_buff * skb)1235 static int __packet_rcv_has_room(const struct packet_sock *po,
1236 const struct sk_buff *skb)
1237 {
1238 const struct sock *sk = &po->sk;
1239 int ret = ROOM_NONE;
1240
1241 if (po->prot_hook.func != tpacket_rcv) {
1242 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1243 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1244 - (skb ? skb->truesize : 0);
1245
1246 if (avail > (rcvbuf >> ROOM_POW_OFF))
1247 return ROOM_NORMAL;
1248 else if (avail > 0)
1249 return ROOM_LOW;
1250 else
1251 return ROOM_NONE;
1252 }
1253
1254 if (po->tp_version == TPACKET_V3) {
1255 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1256 ret = ROOM_NORMAL;
1257 else if (__tpacket_v3_has_room(po, 0))
1258 ret = ROOM_LOW;
1259 } else {
1260 if (__tpacket_has_room(po, ROOM_POW_OFF))
1261 ret = ROOM_NORMAL;
1262 else if (__tpacket_has_room(po, 0))
1263 ret = ROOM_LOW;
1264 }
1265
1266 return ret;
1267 }
1268
packet_rcv_has_room(struct packet_sock * po,struct sk_buff * skb)1269 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1270 {
1271 int pressure, ret;
1272
1273 ret = __packet_rcv_has_room(po, skb);
1274 pressure = ret != ROOM_NORMAL;
1275
1276 if (READ_ONCE(po->pressure) != pressure)
1277 WRITE_ONCE(po->pressure, pressure);
1278
1279 return ret;
1280 }
1281
packet_rcv_try_clear_pressure(struct packet_sock * po)1282 static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1283 {
1284 if (READ_ONCE(po->pressure) &&
1285 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1286 WRITE_ONCE(po->pressure, 0);
1287 }
1288
packet_sock_destruct(struct sock * sk)1289 static void packet_sock_destruct(struct sock *sk)
1290 {
1291 skb_queue_purge(&sk->sk_error_queue);
1292
1293 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1294 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1295
1296 if (!sock_flag(sk, SOCK_DEAD)) {
1297 pr_err("Attempt to release alive packet socket: %p\n", sk);
1298 return;
1299 }
1300
1301 sk_refcnt_debug_dec(sk);
1302 }
1303
fanout_flow_is_huge(struct packet_sock * po,struct sk_buff * skb)1304 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1305 {
1306 u32 *history = po->rollover->history;
1307 u32 victim, rxhash;
1308 int i, count = 0;
1309
1310 rxhash = skb_get_hash(skb);
1311 for (i = 0; i < ROLLOVER_HLEN; i++)
1312 if (READ_ONCE(history[i]) == rxhash)
1313 count++;
1314
1315 victim = prandom_u32() % ROLLOVER_HLEN;
1316
1317 /* Avoid dirtying the cache line if possible */
1318 if (READ_ONCE(history[victim]) != rxhash)
1319 WRITE_ONCE(history[victim], rxhash);
1320
1321 return count > (ROLLOVER_HLEN >> 1);
1322 }
1323
fanout_demux_hash(struct packet_fanout * f,struct sk_buff * skb,unsigned int num)1324 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1325 struct sk_buff *skb,
1326 unsigned int num)
1327 {
1328 return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1329 }
1330
fanout_demux_lb(struct packet_fanout * f,struct sk_buff * skb,unsigned int num)1331 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1332 struct sk_buff *skb,
1333 unsigned int num)
1334 {
1335 unsigned int val = atomic_inc_return(&f->rr_cur);
1336
1337 return val % num;
1338 }
1339
fanout_demux_cpu(struct packet_fanout * f,struct sk_buff * skb,unsigned int num)1340 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1341 struct sk_buff *skb,
1342 unsigned int num)
1343 {
1344 return smp_processor_id() % num;
1345 }
1346
fanout_demux_rnd(struct packet_fanout * f,struct sk_buff * skb,unsigned int num)1347 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1348 struct sk_buff *skb,
1349 unsigned int num)
1350 {
1351 return prandom_u32_max(num);
1352 }
1353
fanout_demux_rollover(struct packet_fanout * f,struct sk_buff * skb,unsigned int idx,bool try_self,unsigned int num)1354 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1355 struct sk_buff *skb,
1356 unsigned int idx, bool try_self,
1357 unsigned int num)
1358 {
1359 struct packet_sock *po, *po_next, *po_skip = NULL;
1360 unsigned int i, j, room = ROOM_NONE;
1361
1362 po = pkt_sk(rcu_dereference(f->arr[idx]));
1363
1364 if (try_self) {
1365 room = packet_rcv_has_room(po, skb);
1366 if (room == ROOM_NORMAL ||
1367 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1368 return idx;
1369 po_skip = po;
1370 }
1371
1372 i = j = min_t(int, po->rollover->sock, num - 1);
1373 do {
1374 po_next = pkt_sk(rcu_dereference(f->arr[i]));
1375 if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1376 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1377 if (i != j)
1378 po->rollover->sock = i;
1379 atomic_long_inc(&po->rollover->num);
1380 if (room == ROOM_LOW)
1381 atomic_long_inc(&po->rollover->num_huge);
1382 return i;
1383 }
1384
1385 if (++i == num)
1386 i = 0;
1387 } while (i != j);
1388
1389 atomic_long_inc(&po->rollover->num_failed);
1390 return idx;
1391 }
1392
fanout_demux_qm(struct packet_fanout * f,struct sk_buff * skb,unsigned int num)1393 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1394 struct sk_buff *skb,
1395 unsigned int num)
1396 {
1397 return skb_get_queue_mapping(skb) % num;
1398 }
1399
fanout_demux_bpf(struct packet_fanout * f,struct sk_buff * skb,unsigned int num)1400 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1401 struct sk_buff *skb,
1402 unsigned int num)
1403 {
1404 struct bpf_prog *prog;
1405 unsigned int ret = 0;
1406
1407 rcu_read_lock();
1408 prog = rcu_dereference(f->bpf_prog);
1409 if (prog)
1410 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1411 rcu_read_unlock();
1412
1413 return ret;
1414 }
1415
fanout_has_flag(struct packet_fanout * f,u16 flag)1416 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1417 {
1418 return f->flags & (flag >> 8);
1419 }
1420
packet_rcv_fanout(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1421 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1422 struct packet_type *pt, struct net_device *orig_dev)
1423 {
1424 struct packet_fanout *f = pt->af_packet_priv;
1425 unsigned int num = READ_ONCE(f->num_members);
1426 struct net *net = read_pnet(&f->net);
1427 struct packet_sock *po;
1428 unsigned int idx;
1429
1430 if (!net_eq(dev_net(dev), net) || !num) {
1431 kfree_skb(skb);
1432 return 0;
1433 }
1434
1435 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1436 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1437 if (!skb)
1438 return 0;
1439 }
1440 switch (f->type) {
1441 case PACKET_FANOUT_HASH:
1442 default:
1443 idx = fanout_demux_hash(f, skb, num);
1444 break;
1445 case PACKET_FANOUT_LB:
1446 idx = fanout_demux_lb(f, skb, num);
1447 break;
1448 case PACKET_FANOUT_CPU:
1449 idx = fanout_demux_cpu(f, skb, num);
1450 break;
1451 case PACKET_FANOUT_RND:
1452 idx = fanout_demux_rnd(f, skb, num);
1453 break;
1454 case PACKET_FANOUT_QM:
1455 idx = fanout_demux_qm(f, skb, num);
1456 break;
1457 case PACKET_FANOUT_ROLLOVER:
1458 idx = fanout_demux_rollover(f, skb, 0, false, num);
1459 break;
1460 case PACKET_FANOUT_CBPF:
1461 case PACKET_FANOUT_EBPF:
1462 idx = fanout_demux_bpf(f, skb, num);
1463 break;
1464 }
1465
1466 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1467 idx = fanout_demux_rollover(f, skb, idx, true, num);
1468
1469 po = pkt_sk(rcu_dereference(f->arr[idx]));
1470 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1471 }
1472
1473 DEFINE_MUTEX(fanout_mutex);
1474 EXPORT_SYMBOL_GPL(fanout_mutex);
1475 static LIST_HEAD(fanout_list);
1476 static u16 fanout_next_id;
1477
__fanout_link(struct sock * sk,struct packet_sock * po)1478 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1479 {
1480 struct packet_fanout *f = po->fanout;
1481
1482 spin_lock(&f->lock);
1483 rcu_assign_pointer(f->arr[f->num_members], sk);
1484 smp_wmb();
1485 f->num_members++;
1486 if (f->num_members == 1)
1487 dev_add_pack(&f->prot_hook);
1488 spin_unlock(&f->lock);
1489 }
1490
__fanout_unlink(struct sock * sk,struct packet_sock * po)1491 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1492 {
1493 struct packet_fanout *f = po->fanout;
1494 int i;
1495
1496 spin_lock(&f->lock);
1497 for (i = 0; i < f->num_members; i++) {
1498 if (rcu_dereference_protected(f->arr[i],
1499 lockdep_is_held(&f->lock)) == sk)
1500 break;
1501 }
1502 BUG_ON(i >= f->num_members);
1503 rcu_assign_pointer(f->arr[i],
1504 rcu_dereference_protected(f->arr[f->num_members - 1],
1505 lockdep_is_held(&f->lock)));
1506 f->num_members--;
1507 if (f->num_members == 0)
1508 __dev_remove_pack(&f->prot_hook);
1509 spin_unlock(&f->lock);
1510 }
1511
match_fanout_group(struct packet_type * ptype,struct sock * sk)1512 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1513 {
1514 if (sk->sk_family != PF_PACKET)
1515 return false;
1516
1517 return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1518 }
1519
fanout_init_data(struct packet_fanout * f)1520 static void fanout_init_data(struct packet_fanout *f)
1521 {
1522 switch (f->type) {
1523 case PACKET_FANOUT_LB:
1524 atomic_set(&f->rr_cur, 0);
1525 break;
1526 case PACKET_FANOUT_CBPF:
1527 case PACKET_FANOUT_EBPF:
1528 RCU_INIT_POINTER(f->bpf_prog, NULL);
1529 break;
1530 }
1531 }
1532
__fanout_set_data_bpf(struct packet_fanout * f,struct bpf_prog * new)1533 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1534 {
1535 struct bpf_prog *old;
1536
1537 spin_lock(&f->lock);
1538 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1539 rcu_assign_pointer(f->bpf_prog, new);
1540 spin_unlock(&f->lock);
1541
1542 if (old) {
1543 synchronize_net();
1544 bpf_prog_destroy(old);
1545 }
1546 }
1547
fanout_set_data_cbpf(struct packet_sock * po,sockptr_t data,unsigned int len)1548 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1549 unsigned int len)
1550 {
1551 struct bpf_prog *new;
1552 struct sock_fprog fprog;
1553 int ret;
1554
1555 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1556 return -EPERM;
1557
1558 ret = copy_bpf_fprog_from_user(&fprog, data, len);
1559 if (ret)
1560 return ret;
1561
1562 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1563 if (ret)
1564 return ret;
1565
1566 __fanout_set_data_bpf(po->fanout, new);
1567 return 0;
1568 }
1569
fanout_set_data_ebpf(struct packet_sock * po,sockptr_t data,unsigned int len)1570 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1571 unsigned int len)
1572 {
1573 struct bpf_prog *new;
1574 u32 fd;
1575
1576 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1577 return -EPERM;
1578 if (len != sizeof(fd))
1579 return -EINVAL;
1580 if (copy_from_sockptr(&fd, data, len))
1581 return -EFAULT;
1582
1583 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1584 if (IS_ERR(new))
1585 return PTR_ERR(new);
1586
1587 __fanout_set_data_bpf(po->fanout, new);
1588 return 0;
1589 }
1590
fanout_set_data(struct packet_sock * po,sockptr_t data,unsigned int len)1591 static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1592 unsigned int len)
1593 {
1594 switch (po->fanout->type) {
1595 case PACKET_FANOUT_CBPF:
1596 return fanout_set_data_cbpf(po, data, len);
1597 case PACKET_FANOUT_EBPF:
1598 return fanout_set_data_ebpf(po, data, len);
1599 default:
1600 return -EINVAL;
1601 }
1602 }
1603
fanout_release_data(struct packet_fanout * f)1604 static void fanout_release_data(struct packet_fanout *f)
1605 {
1606 switch (f->type) {
1607 case PACKET_FANOUT_CBPF:
1608 case PACKET_FANOUT_EBPF:
1609 __fanout_set_data_bpf(f, NULL);
1610 }
1611 }
1612
__fanout_id_is_free(struct sock * sk,u16 candidate_id)1613 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1614 {
1615 struct packet_fanout *f;
1616
1617 list_for_each_entry(f, &fanout_list, list) {
1618 if (f->id == candidate_id &&
1619 read_pnet(&f->net) == sock_net(sk)) {
1620 return false;
1621 }
1622 }
1623 return true;
1624 }
1625
fanout_find_new_id(struct sock * sk,u16 * new_id)1626 static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1627 {
1628 u16 id = fanout_next_id;
1629
1630 do {
1631 if (__fanout_id_is_free(sk, id)) {
1632 *new_id = id;
1633 fanout_next_id = id + 1;
1634 return true;
1635 }
1636
1637 id++;
1638 } while (id != fanout_next_id);
1639
1640 return false;
1641 }
1642
fanout_add(struct sock * sk,struct fanout_args * args)1643 static int fanout_add(struct sock *sk, struct fanout_args *args)
1644 {
1645 struct packet_rollover *rollover = NULL;
1646 struct packet_sock *po = pkt_sk(sk);
1647 u16 type_flags = args->type_flags;
1648 struct packet_fanout *f, *match;
1649 u8 type = type_flags & 0xff;
1650 u8 flags = type_flags >> 8;
1651 u16 id = args->id;
1652 int err;
1653
1654 switch (type) {
1655 case PACKET_FANOUT_ROLLOVER:
1656 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1657 return -EINVAL;
1658 case PACKET_FANOUT_HASH:
1659 case PACKET_FANOUT_LB:
1660 case PACKET_FANOUT_CPU:
1661 case PACKET_FANOUT_RND:
1662 case PACKET_FANOUT_QM:
1663 case PACKET_FANOUT_CBPF:
1664 case PACKET_FANOUT_EBPF:
1665 break;
1666 default:
1667 return -EINVAL;
1668 }
1669
1670 mutex_lock(&fanout_mutex);
1671
1672 err = -EALREADY;
1673 if (po->fanout)
1674 goto out;
1675
1676 if (type == PACKET_FANOUT_ROLLOVER ||
1677 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1678 err = -ENOMEM;
1679 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1680 if (!rollover)
1681 goto out;
1682 atomic_long_set(&rollover->num, 0);
1683 atomic_long_set(&rollover->num_huge, 0);
1684 atomic_long_set(&rollover->num_failed, 0);
1685 }
1686
1687 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1688 if (id != 0) {
1689 err = -EINVAL;
1690 goto out;
1691 }
1692 if (!fanout_find_new_id(sk, &id)) {
1693 err = -ENOMEM;
1694 goto out;
1695 }
1696 /* ephemeral flag for the first socket in the group: drop it */
1697 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1698 }
1699
1700 match = NULL;
1701 list_for_each_entry(f, &fanout_list, list) {
1702 if (f->id == id &&
1703 read_pnet(&f->net) == sock_net(sk)) {
1704 match = f;
1705 break;
1706 }
1707 }
1708 err = -EINVAL;
1709 if (match) {
1710 if (match->flags != flags)
1711 goto out;
1712 if (args->max_num_members &&
1713 args->max_num_members != match->max_num_members)
1714 goto out;
1715 } else {
1716 if (args->max_num_members > PACKET_FANOUT_MAX)
1717 goto out;
1718 if (!args->max_num_members)
1719 /* legacy PACKET_FANOUT_MAX */
1720 args->max_num_members = 256;
1721 err = -ENOMEM;
1722 match = kvzalloc(struct_size(match, arr, args->max_num_members),
1723 GFP_KERNEL);
1724 if (!match)
1725 goto out;
1726 write_pnet(&match->net, sock_net(sk));
1727 match->id = id;
1728 match->type = type;
1729 match->flags = flags;
1730 INIT_LIST_HEAD(&match->list);
1731 spin_lock_init(&match->lock);
1732 refcount_set(&match->sk_ref, 0);
1733 fanout_init_data(match);
1734 match->prot_hook.type = po->prot_hook.type;
1735 match->prot_hook.dev = po->prot_hook.dev;
1736 match->prot_hook.func = packet_rcv_fanout;
1737 match->prot_hook.af_packet_priv = match;
1738 match->prot_hook.af_packet_net = read_pnet(&match->net);
1739 match->prot_hook.id_match = match_fanout_group;
1740 match->max_num_members = args->max_num_members;
1741 list_add(&match->list, &fanout_list);
1742 }
1743 err = -EINVAL;
1744
1745 spin_lock(&po->bind_lock);
1746 if (po->running &&
1747 match->type == type &&
1748 match->prot_hook.type == po->prot_hook.type &&
1749 match->prot_hook.dev == po->prot_hook.dev) {
1750 err = -ENOSPC;
1751 if (refcount_read(&match->sk_ref) < match->max_num_members) {
1752 __dev_remove_pack(&po->prot_hook);
1753
1754 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
1755 WRITE_ONCE(po->fanout, match);
1756
1757 po->rollover = rollover;
1758 rollover = NULL;
1759 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1760 __fanout_link(sk, po);
1761 err = 0;
1762 }
1763 }
1764 spin_unlock(&po->bind_lock);
1765
1766 if (err && !refcount_read(&match->sk_ref)) {
1767 list_del(&match->list);
1768 kvfree(match);
1769 }
1770
1771 out:
1772 kfree(rollover);
1773 mutex_unlock(&fanout_mutex);
1774 return err;
1775 }
1776
1777 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1778 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1779 * It is the responsibility of the caller to call fanout_release_data() and
1780 * free the returned packet_fanout (after synchronize_net())
1781 */
fanout_release(struct sock * sk)1782 static struct packet_fanout *fanout_release(struct sock *sk)
1783 {
1784 struct packet_sock *po = pkt_sk(sk);
1785 struct packet_fanout *f;
1786
1787 mutex_lock(&fanout_mutex);
1788 f = po->fanout;
1789 if (f) {
1790 po->fanout = NULL;
1791
1792 if (refcount_dec_and_test(&f->sk_ref))
1793 list_del(&f->list);
1794 else
1795 f = NULL;
1796 }
1797 mutex_unlock(&fanout_mutex);
1798
1799 return f;
1800 }
1801
packet_extra_vlan_len_allowed(const struct net_device * dev,struct sk_buff * skb)1802 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1803 struct sk_buff *skb)
1804 {
1805 /* Earlier code assumed this would be a VLAN pkt, double-check
1806 * this now that we have the actual packet in hand. We can only
1807 * do this check on Ethernet devices.
1808 */
1809 if (unlikely(dev->type != ARPHRD_ETHER))
1810 return false;
1811
1812 skb_reset_mac_header(skb);
1813 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1814 }
1815
1816 static const struct proto_ops packet_ops;
1817
1818 static const struct proto_ops packet_ops_spkt;
1819
packet_rcv_spkt(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1820 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1821 struct packet_type *pt, struct net_device *orig_dev)
1822 {
1823 struct sock *sk;
1824 struct sockaddr_pkt *spkt;
1825
1826 /*
1827 * When we registered the protocol we saved the socket in the data
1828 * field for just this event.
1829 */
1830
1831 sk = pt->af_packet_priv;
1832
1833 /*
1834 * Yank back the headers [hope the device set this
1835 * right or kerboom...]
1836 *
1837 * Incoming packets have ll header pulled,
1838 * push it back.
1839 *
1840 * For outgoing ones skb->data == skb_mac_header(skb)
1841 * so that this procedure is noop.
1842 */
1843
1844 if (skb->pkt_type == PACKET_LOOPBACK)
1845 goto out;
1846
1847 if (!net_eq(dev_net(dev), sock_net(sk)))
1848 goto out;
1849
1850 skb = skb_share_check(skb, GFP_ATOMIC);
1851 if (skb == NULL)
1852 goto oom;
1853
1854 /* drop any routing info */
1855 skb_dst_drop(skb);
1856
1857 /* drop conntrack reference */
1858 nf_reset_ct(skb);
1859
1860 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1861
1862 skb_push(skb, skb->data - skb_mac_header(skb));
1863
1864 /*
1865 * The SOCK_PACKET socket receives _all_ frames.
1866 */
1867
1868 spkt->spkt_family = dev->type;
1869 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1870 spkt->spkt_protocol = skb->protocol;
1871
1872 /*
1873 * Charge the memory to the socket. This is done specifically
1874 * to prevent sockets using all the memory up.
1875 */
1876
1877 if (sock_queue_rcv_skb(sk, skb) == 0)
1878 return 0;
1879
1880 out:
1881 kfree_skb(skb);
1882 oom:
1883 return 0;
1884 }
1885
packet_parse_headers(struct sk_buff * skb,struct socket * sock)1886 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1887 {
1888 int depth;
1889
1890 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1891 sock->type == SOCK_RAW) {
1892 skb_reset_mac_header(skb);
1893 skb->protocol = dev_parse_header_protocol(skb);
1894 }
1895
1896 /* Move network header to the right position for VLAN tagged packets */
1897 if (likely(skb->dev->type == ARPHRD_ETHER) &&
1898 eth_type_vlan(skb->protocol) &&
1899 __vlan_get_protocol(skb, skb->protocol, &depth) != 0) {
1900 if (pskb_may_pull(skb, depth))
1901 skb_set_network_header(skb, depth);
1902 }
1903
1904 skb_probe_transport_header(skb);
1905 }
1906
1907 /*
1908 * Output a raw packet to a device layer. This bypasses all the other
1909 * protocol layers and you must therefore supply it with a complete frame
1910 */
1911
packet_sendmsg_spkt(struct socket * sock,struct msghdr * msg,size_t len)1912 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1913 size_t len)
1914 {
1915 struct sock *sk = sock->sk;
1916 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1917 struct sk_buff *skb = NULL;
1918 struct net_device *dev;
1919 struct sockcm_cookie sockc;
1920 __be16 proto = 0;
1921 int err;
1922 int extra_len = 0;
1923
1924 /*
1925 * Get and verify the address.
1926 */
1927
1928 if (saddr) {
1929 if (msg->msg_namelen < sizeof(struct sockaddr))
1930 return -EINVAL;
1931 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1932 proto = saddr->spkt_protocol;
1933 } else
1934 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1935
1936 /*
1937 * Find the device first to size check it
1938 */
1939
1940 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1941 retry:
1942 rcu_read_lock();
1943 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1944 err = -ENODEV;
1945 if (dev == NULL)
1946 goto out_unlock;
1947
1948 err = -ENETDOWN;
1949 if (!(dev->flags & IFF_UP))
1950 goto out_unlock;
1951
1952 /*
1953 * You may not queue a frame bigger than the mtu. This is the lowest level
1954 * raw protocol and you must do your own fragmentation at this level.
1955 */
1956
1957 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1958 if (!netif_supports_nofcs(dev)) {
1959 err = -EPROTONOSUPPORT;
1960 goto out_unlock;
1961 }
1962 extra_len = 4; /* We're doing our own CRC */
1963 }
1964
1965 err = -EMSGSIZE;
1966 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1967 goto out_unlock;
1968
1969 if (!skb) {
1970 size_t reserved = LL_RESERVED_SPACE(dev);
1971 int tlen = dev->needed_tailroom;
1972 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1973
1974 rcu_read_unlock();
1975 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1976 if (skb == NULL)
1977 return -ENOBUFS;
1978 /* FIXME: Save some space for broken drivers that write a hard
1979 * header at transmission time by themselves. PPP is the notable
1980 * one here. This should really be fixed at the driver level.
1981 */
1982 skb_reserve(skb, reserved);
1983 skb_reset_network_header(skb);
1984
1985 /* Try to align data part correctly */
1986 if (hhlen) {
1987 skb->data -= hhlen;
1988 skb->tail -= hhlen;
1989 if (len < hhlen)
1990 skb_reset_network_header(skb);
1991 }
1992 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1993 if (err)
1994 goto out_free;
1995 goto retry;
1996 }
1997
1998 if (!dev_validate_header(dev, skb->data, len)) {
1999 err = -EINVAL;
2000 goto out_unlock;
2001 }
2002 if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
2003 !packet_extra_vlan_len_allowed(dev, skb)) {
2004 err = -EMSGSIZE;
2005 goto out_unlock;
2006 }
2007
2008 sockcm_init(&sockc, sk);
2009 if (msg->msg_controllen) {
2010 err = sock_cmsg_send(sk, msg, &sockc);
2011 if (unlikely(err))
2012 goto out_unlock;
2013 }
2014
2015 skb->protocol = proto;
2016 skb->dev = dev;
2017 skb->priority = sk->sk_priority;
2018 skb->mark = sk->sk_mark;
2019 skb->tstamp = sockc.transmit_time;
2020
2021 skb_setup_tx_timestamp(skb, sockc.tsflags);
2022
2023 if (unlikely(extra_len == 4))
2024 skb->no_fcs = 1;
2025
2026 packet_parse_headers(skb, sock);
2027
2028 dev_queue_xmit(skb);
2029 rcu_read_unlock();
2030 return len;
2031
2032 out_unlock:
2033 rcu_read_unlock();
2034 out_free:
2035 kfree_skb(skb);
2036 return err;
2037 }
2038
run_filter(struct sk_buff * skb,const struct sock * sk,unsigned int res)2039 static unsigned int run_filter(struct sk_buff *skb,
2040 const struct sock *sk,
2041 unsigned int res)
2042 {
2043 struct sk_filter *filter;
2044
2045 rcu_read_lock();
2046 filter = rcu_dereference(sk->sk_filter);
2047 if (filter != NULL)
2048 res = bpf_prog_run_clear_cb(filter->prog, skb);
2049 rcu_read_unlock();
2050
2051 return res;
2052 }
2053
packet_rcv_vnet(struct msghdr * msg,const struct sk_buff * skb,size_t * len)2054 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2055 size_t *len)
2056 {
2057 struct virtio_net_hdr vnet_hdr;
2058
2059 if (*len < sizeof(vnet_hdr))
2060 return -EINVAL;
2061 *len -= sizeof(vnet_hdr);
2062
2063 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2064 return -EINVAL;
2065
2066 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2067 }
2068
2069 /*
2070 * This function makes lazy skb cloning in hope that most of packets
2071 * are discarded by BPF.
2072 *
2073 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2074 * and skb->cb are mangled. It works because (and until) packets
2075 * falling here are owned by current CPU. Output packets are cloned
2076 * by dev_queue_xmit_nit(), input packets are processed by net_bh
2077 * sequencially, so that if we return skb to original state on exit,
2078 * we will not harm anyone.
2079 */
2080
packet_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)2081 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2082 struct packet_type *pt, struct net_device *orig_dev)
2083 {
2084 struct sock *sk;
2085 struct sockaddr_ll *sll;
2086 struct packet_sock *po;
2087 u8 *skb_head = skb->data;
2088 int skb_len = skb->len;
2089 unsigned int snaplen, res;
2090 bool is_drop_n_account = false;
2091
2092 if (skb->pkt_type == PACKET_LOOPBACK)
2093 goto drop;
2094
2095 sk = pt->af_packet_priv;
2096 po = pkt_sk(sk);
2097
2098 if (!net_eq(dev_net(dev), sock_net(sk)))
2099 goto drop;
2100
2101 skb->dev = dev;
2102
2103 if (dev_has_header(dev)) {
2104 /* The device has an explicit notion of ll header,
2105 * exported to higher levels.
2106 *
2107 * Otherwise, the device hides details of its frame
2108 * structure, so that corresponding packet head is
2109 * never delivered to user.
2110 */
2111 if (sk->sk_type != SOCK_DGRAM)
2112 skb_push(skb, skb->data - skb_mac_header(skb));
2113 else if (skb->pkt_type == PACKET_OUTGOING) {
2114 /* Special case: outgoing packets have ll header at head */
2115 skb_pull(skb, skb_network_offset(skb));
2116 }
2117 }
2118
2119 snaplen = skb->len;
2120
2121 res = run_filter(skb, sk, snaplen);
2122 if (!res)
2123 goto drop_n_restore;
2124 if (snaplen > res)
2125 snaplen = res;
2126
2127 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2128 goto drop_n_acct;
2129
2130 if (skb_shared(skb)) {
2131 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2132 if (nskb == NULL)
2133 goto drop_n_acct;
2134
2135 if (skb_head != skb->data) {
2136 skb->data = skb_head;
2137 skb->len = skb_len;
2138 }
2139 consume_skb(skb);
2140 skb = nskb;
2141 }
2142
2143 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2144
2145 sll = &PACKET_SKB_CB(skb)->sa.ll;
2146 sll->sll_hatype = dev->type;
2147 sll->sll_pkttype = skb->pkt_type;
2148 if (unlikely(po->origdev))
2149 sll->sll_ifindex = orig_dev->ifindex;
2150 else
2151 sll->sll_ifindex = dev->ifindex;
2152
2153 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2154
2155 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2156 * Use their space for storing the original skb length.
2157 */
2158 PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2159
2160 if (pskb_trim(skb, snaplen))
2161 goto drop_n_acct;
2162
2163 skb_set_owner_r(skb, sk);
2164 skb->dev = NULL;
2165 skb_dst_drop(skb);
2166
2167 /* drop conntrack reference */
2168 nf_reset_ct(skb);
2169
2170 spin_lock(&sk->sk_receive_queue.lock);
2171 po->stats.stats1.tp_packets++;
2172 sock_skb_set_dropcount(sk, skb);
2173 __skb_queue_tail(&sk->sk_receive_queue, skb);
2174 spin_unlock(&sk->sk_receive_queue.lock);
2175 sk->sk_data_ready(sk);
2176 return 0;
2177
2178 drop_n_acct:
2179 is_drop_n_account = true;
2180 atomic_inc(&po->tp_drops);
2181 atomic_inc(&sk->sk_drops);
2182
2183 drop_n_restore:
2184 if (skb_head != skb->data && skb_shared(skb)) {
2185 skb->data = skb_head;
2186 skb->len = skb_len;
2187 }
2188 drop:
2189 if (!is_drop_n_account)
2190 consume_skb(skb);
2191 else
2192 kfree_skb(skb);
2193 return 0;
2194 }
2195
tpacket_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)2196 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2197 struct packet_type *pt, struct net_device *orig_dev)
2198 {
2199 struct sock *sk;
2200 struct packet_sock *po;
2201 struct sockaddr_ll *sll;
2202 union tpacket_uhdr h;
2203 u8 *skb_head = skb->data;
2204 int skb_len = skb->len;
2205 unsigned int snaplen, res;
2206 unsigned long status = TP_STATUS_USER;
2207 unsigned short macoff, hdrlen;
2208 unsigned int netoff;
2209 struct sk_buff *copy_skb = NULL;
2210 struct timespec64 ts;
2211 __u32 ts_status;
2212 bool is_drop_n_account = false;
2213 unsigned int slot_id = 0;
2214 bool do_vnet = false;
2215
2216 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2217 * We may add members to them until current aligned size without forcing
2218 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2219 */
2220 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2221 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2222
2223 if (skb->pkt_type == PACKET_LOOPBACK)
2224 goto drop;
2225
2226 sk = pt->af_packet_priv;
2227 po = pkt_sk(sk);
2228
2229 if (!net_eq(dev_net(dev), sock_net(sk)))
2230 goto drop;
2231
2232 if (dev_has_header(dev)) {
2233 if (sk->sk_type != SOCK_DGRAM)
2234 skb_push(skb, skb->data - skb_mac_header(skb));
2235 else if (skb->pkt_type == PACKET_OUTGOING) {
2236 /* Special case: outgoing packets have ll header at head */
2237 skb_pull(skb, skb_network_offset(skb));
2238 }
2239 }
2240
2241 snaplen = skb->len;
2242
2243 res = run_filter(skb, sk, snaplen);
2244 if (!res)
2245 goto drop_n_restore;
2246
2247 /* If we are flooded, just give up */
2248 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2249 atomic_inc(&po->tp_drops);
2250 goto drop_n_restore;
2251 }
2252
2253 if (skb->ip_summed == CHECKSUM_PARTIAL)
2254 status |= TP_STATUS_CSUMNOTREADY;
2255 else if (skb->pkt_type != PACKET_OUTGOING &&
2256 skb_csum_unnecessary(skb))
2257 status |= TP_STATUS_CSUM_VALID;
2258
2259 if (snaplen > res)
2260 snaplen = res;
2261
2262 if (sk->sk_type == SOCK_DGRAM) {
2263 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2264 po->tp_reserve;
2265 } else {
2266 unsigned int maclen = skb_network_offset(skb);
2267 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2268 (maclen < 16 ? 16 : maclen)) +
2269 po->tp_reserve;
2270 if (po->has_vnet_hdr) {
2271 netoff += sizeof(struct virtio_net_hdr);
2272 do_vnet = true;
2273 }
2274 macoff = netoff - maclen;
2275 }
2276 if (netoff > USHRT_MAX) {
2277 atomic_inc(&po->tp_drops);
2278 goto drop_n_restore;
2279 }
2280 if (po->tp_version <= TPACKET_V2) {
2281 if (macoff + snaplen > po->rx_ring.frame_size) {
2282 if (po->copy_thresh &&
2283 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2284 if (skb_shared(skb)) {
2285 copy_skb = skb_clone(skb, GFP_ATOMIC);
2286 } else {
2287 copy_skb = skb_get(skb);
2288 skb_head = skb->data;
2289 }
2290 if (copy_skb) {
2291 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0,
2292 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll));
2293 skb_set_owner_r(copy_skb, sk);
2294 }
2295 }
2296 snaplen = po->rx_ring.frame_size - macoff;
2297 if ((int)snaplen < 0) {
2298 snaplen = 0;
2299 do_vnet = false;
2300 }
2301 }
2302 } else if (unlikely(macoff + snaplen >
2303 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2304 u32 nval;
2305
2306 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2307 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2308 snaplen, nval, macoff);
2309 snaplen = nval;
2310 if (unlikely((int)snaplen < 0)) {
2311 snaplen = 0;
2312 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2313 do_vnet = false;
2314 }
2315 }
2316 spin_lock(&sk->sk_receive_queue.lock);
2317 h.raw = packet_current_rx_frame(po, skb,
2318 TP_STATUS_KERNEL, (macoff+snaplen));
2319 if (!h.raw)
2320 goto drop_n_account;
2321
2322 if (po->tp_version <= TPACKET_V2) {
2323 slot_id = po->rx_ring.head;
2324 if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2325 goto drop_n_account;
2326 __set_bit(slot_id, po->rx_ring.rx_owner_map);
2327 }
2328
2329 if (do_vnet &&
2330 virtio_net_hdr_from_skb(skb, h.raw + macoff -
2331 sizeof(struct virtio_net_hdr),
2332 vio_le(), true, 0)) {
2333 if (po->tp_version == TPACKET_V3)
2334 prb_clear_blk_fill_status(&po->rx_ring);
2335 goto drop_n_account;
2336 }
2337
2338 if (po->tp_version <= TPACKET_V2) {
2339 packet_increment_rx_head(po, &po->rx_ring);
2340 /*
2341 * LOSING will be reported till you read the stats,
2342 * because it's COR - Clear On Read.
2343 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2344 * at packet level.
2345 */
2346 if (atomic_read(&po->tp_drops))
2347 status |= TP_STATUS_LOSING;
2348 }
2349
2350 po->stats.stats1.tp_packets++;
2351 if (copy_skb) {
2352 status |= TP_STATUS_COPY;
2353 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2354 }
2355 spin_unlock(&sk->sk_receive_queue.lock);
2356
2357 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2358
2359 /* Always timestamp; prefer an existing software timestamp taken
2360 * closer to the time of capture.
2361 */
2362 ts_status = tpacket_get_timestamp(skb, &ts,
2363 po->tp_tstamp | SOF_TIMESTAMPING_SOFTWARE);
2364 if (!ts_status)
2365 ktime_get_real_ts64(&ts);
2366
2367 status |= ts_status;
2368
2369 switch (po->tp_version) {
2370 case TPACKET_V1:
2371 h.h1->tp_len = skb->len;
2372 h.h1->tp_snaplen = snaplen;
2373 h.h1->tp_mac = macoff;
2374 h.h1->tp_net = netoff;
2375 h.h1->tp_sec = ts.tv_sec;
2376 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2377 hdrlen = sizeof(*h.h1);
2378 break;
2379 case TPACKET_V2:
2380 h.h2->tp_len = skb->len;
2381 h.h2->tp_snaplen = snaplen;
2382 h.h2->tp_mac = macoff;
2383 h.h2->tp_net = netoff;
2384 h.h2->tp_sec = ts.tv_sec;
2385 h.h2->tp_nsec = ts.tv_nsec;
2386 if (skb_vlan_tag_present(skb)) {
2387 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2388 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2389 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2390 } else {
2391 h.h2->tp_vlan_tci = 0;
2392 h.h2->tp_vlan_tpid = 0;
2393 }
2394 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2395 hdrlen = sizeof(*h.h2);
2396 break;
2397 case TPACKET_V3:
2398 /* tp_nxt_offset,vlan are already populated above.
2399 * So DONT clear those fields here
2400 */
2401 h.h3->tp_status |= status;
2402 h.h3->tp_len = skb->len;
2403 h.h3->tp_snaplen = snaplen;
2404 h.h3->tp_mac = macoff;
2405 h.h3->tp_net = netoff;
2406 h.h3->tp_sec = ts.tv_sec;
2407 h.h3->tp_nsec = ts.tv_nsec;
2408 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2409 hdrlen = sizeof(*h.h3);
2410 break;
2411 default:
2412 BUG();
2413 }
2414
2415 sll = h.raw + TPACKET_ALIGN(hdrlen);
2416 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2417 sll->sll_family = AF_PACKET;
2418 sll->sll_hatype = dev->type;
2419 sll->sll_protocol = skb->protocol;
2420 sll->sll_pkttype = skb->pkt_type;
2421 if (unlikely(po->origdev))
2422 sll->sll_ifindex = orig_dev->ifindex;
2423 else
2424 sll->sll_ifindex = dev->ifindex;
2425
2426 smp_mb();
2427
2428 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2429 if (po->tp_version <= TPACKET_V2) {
2430 u8 *start, *end;
2431
2432 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2433 macoff + snaplen);
2434
2435 for (start = h.raw; start < end; start += PAGE_SIZE)
2436 flush_dcache_page(pgv_to_page(start));
2437 }
2438 smp_wmb();
2439 #endif
2440
2441 if (po->tp_version <= TPACKET_V2) {
2442 spin_lock(&sk->sk_receive_queue.lock);
2443 __packet_set_status(po, h.raw, status);
2444 __clear_bit(slot_id, po->rx_ring.rx_owner_map);
2445 spin_unlock(&sk->sk_receive_queue.lock);
2446 sk->sk_data_ready(sk);
2447 } else if (po->tp_version == TPACKET_V3) {
2448 prb_clear_blk_fill_status(&po->rx_ring);
2449 }
2450
2451 drop_n_restore:
2452 if (skb_head != skb->data && skb_shared(skb)) {
2453 skb->data = skb_head;
2454 skb->len = skb_len;
2455 }
2456 drop:
2457 if (!is_drop_n_account)
2458 consume_skb(skb);
2459 else
2460 kfree_skb(skb);
2461 return 0;
2462
2463 drop_n_account:
2464 spin_unlock(&sk->sk_receive_queue.lock);
2465 atomic_inc(&po->tp_drops);
2466 is_drop_n_account = true;
2467
2468 sk->sk_data_ready(sk);
2469 kfree_skb(copy_skb);
2470 goto drop_n_restore;
2471 }
2472
tpacket_destruct_skb(struct sk_buff * skb)2473 static void tpacket_destruct_skb(struct sk_buff *skb)
2474 {
2475 struct packet_sock *po = pkt_sk(skb->sk);
2476
2477 if (likely(po->tx_ring.pg_vec)) {
2478 void *ph;
2479 __u32 ts;
2480
2481 ph = skb_zcopy_get_nouarg(skb);
2482 packet_dec_pending(&po->tx_ring);
2483
2484 ts = __packet_set_timestamp(po, ph, skb);
2485 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2486
2487 if (!packet_read_pending(&po->tx_ring))
2488 complete(&po->skb_completion);
2489 }
2490
2491 sock_wfree(skb);
2492 }
2493
__packet_snd_vnet_parse(struct virtio_net_hdr * vnet_hdr,size_t len)2494 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2495 {
2496 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2497 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2498 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2499 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2500 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2501 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2502 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2503
2504 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2505 return -EINVAL;
2506
2507 return 0;
2508 }
2509
packet_snd_vnet_parse(struct msghdr * msg,size_t * len,struct virtio_net_hdr * vnet_hdr)2510 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2511 struct virtio_net_hdr *vnet_hdr)
2512 {
2513 if (*len < sizeof(*vnet_hdr))
2514 return -EINVAL;
2515 *len -= sizeof(*vnet_hdr);
2516
2517 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2518 return -EFAULT;
2519
2520 return __packet_snd_vnet_parse(vnet_hdr, *len);
2521 }
2522
tpacket_fill_skb(struct packet_sock * po,struct sk_buff * skb,void * frame,struct net_device * dev,void * data,int tp_len,__be16 proto,unsigned char * addr,int hlen,int copylen,const struct sockcm_cookie * sockc)2523 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2524 void *frame, struct net_device *dev, void *data, int tp_len,
2525 __be16 proto, unsigned char *addr, int hlen, int copylen,
2526 const struct sockcm_cookie *sockc)
2527 {
2528 union tpacket_uhdr ph;
2529 int to_write, offset, len, nr_frags, len_max;
2530 struct socket *sock = po->sk.sk_socket;
2531 struct page *page;
2532 int err;
2533
2534 ph.raw = frame;
2535
2536 skb->protocol = proto;
2537 skb->dev = dev;
2538 skb->priority = po->sk.sk_priority;
2539 skb->mark = po->sk.sk_mark;
2540 skb->tstamp = sockc->transmit_time;
2541 skb_setup_tx_timestamp(skb, sockc->tsflags);
2542 skb_zcopy_set_nouarg(skb, ph.raw);
2543
2544 skb_reserve(skb, hlen);
2545 skb_reset_network_header(skb);
2546
2547 to_write = tp_len;
2548
2549 if (sock->type == SOCK_DGRAM) {
2550 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2551 NULL, tp_len);
2552 if (unlikely(err < 0))
2553 return -EINVAL;
2554 } else if (copylen) {
2555 int hdrlen = min_t(int, copylen, tp_len);
2556
2557 skb_push(skb, dev->hard_header_len);
2558 skb_put(skb, copylen - dev->hard_header_len);
2559 err = skb_store_bits(skb, 0, data, hdrlen);
2560 if (unlikely(err))
2561 return err;
2562 if (!dev_validate_header(dev, skb->data, hdrlen))
2563 return -EINVAL;
2564
2565 data += hdrlen;
2566 to_write -= hdrlen;
2567 }
2568
2569 offset = offset_in_page(data);
2570 len_max = PAGE_SIZE - offset;
2571 len = ((to_write > len_max) ? len_max : to_write);
2572
2573 skb->data_len = to_write;
2574 skb->len += to_write;
2575 skb->truesize += to_write;
2576 refcount_add(to_write, &po->sk.sk_wmem_alloc);
2577
2578 while (likely(to_write)) {
2579 nr_frags = skb_shinfo(skb)->nr_frags;
2580
2581 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2582 pr_err("Packet exceed the number of skb frags(%lu)\n",
2583 MAX_SKB_FRAGS);
2584 return -EFAULT;
2585 }
2586
2587 page = pgv_to_page(data);
2588 data += len;
2589 flush_dcache_page(page);
2590 get_page(page);
2591 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2592 to_write -= len;
2593 offset = 0;
2594 len_max = PAGE_SIZE;
2595 len = ((to_write > len_max) ? len_max : to_write);
2596 }
2597
2598 packet_parse_headers(skb, sock);
2599
2600 return tp_len;
2601 }
2602
tpacket_parse_header(struct packet_sock * po,void * frame,int size_max,void ** data)2603 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2604 int size_max, void **data)
2605 {
2606 union tpacket_uhdr ph;
2607 int tp_len, off;
2608
2609 ph.raw = frame;
2610
2611 switch (po->tp_version) {
2612 case TPACKET_V3:
2613 if (ph.h3->tp_next_offset != 0) {
2614 pr_warn_once("variable sized slot not supported");
2615 return -EINVAL;
2616 }
2617 tp_len = ph.h3->tp_len;
2618 break;
2619 case TPACKET_V2:
2620 tp_len = ph.h2->tp_len;
2621 break;
2622 default:
2623 tp_len = ph.h1->tp_len;
2624 break;
2625 }
2626 if (unlikely(tp_len > size_max)) {
2627 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2628 return -EMSGSIZE;
2629 }
2630
2631 if (unlikely(po->tp_tx_has_off)) {
2632 int off_min, off_max;
2633
2634 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2635 off_max = po->tx_ring.frame_size - tp_len;
2636 if (po->sk.sk_type == SOCK_DGRAM) {
2637 switch (po->tp_version) {
2638 case TPACKET_V3:
2639 off = ph.h3->tp_net;
2640 break;
2641 case TPACKET_V2:
2642 off = ph.h2->tp_net;
2643 break;
2644 default:
2645 off = ph.h1->tp_net;
2646 break;
2647 }
2648 } else {
2649 switch (po->tp_version) {
2650 case TPACKET_V3:
2651 off = ph.h3->tp_mac;
2652 break;
2653 case TPACKET_V2:
2654 off = ph.h2->tp_mac;
2655 break;
2656 default:
2657 off = ph.h1->tp_mac;
2658 break;
2659 }
2660 }
2661 if (unlikely((off < off_min) || (off_max < off)))
2662 return -EINVAL;
2663 } else {
2664 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2665 }
2666
2667 *data = frame + off;
2668 return tp_len;
2669 }
2670
tpacket_snd(struct packet_sock * po,struct msghdr * msg)2671 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2672 {
2673 struct sk_buff *skb = NULL;
2674 struct net_device *dev;
2675 struct virtio_net_hdr *vnet_hdr = NULL;
2676 struct sockcm_cookie sockc;
2677 __be16 proto;
2678 int err, reserve = 0;
2679 void *ph;
2680 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2681 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2682 unsigned char *addr = NULL;
2683 int tp_len, size_max;
2684 void *data;
2685 int len_sum = 0;
2686 int status = TP_STATUS_AVAILABLE;
2687 int hlen, tlen, copylen = 0;
2688 long timeo = 0;
2689
2690 mutex_lock(&po->pg_vec_lock);
2691
2692 /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2693 * we need to confirm it under protection of pg_vec_lock.
2694 */
2695 if (unlikely(!po->tx_ring.pg_vec)) {
2696 err = -EBUSY;
2697 goto out;
2698 }
2699 if (likely(saddr == NULL)) {
2700 dev = packet_cached_dev_get(po);
2701 proto = READ_ONCE(po->num);
2702 } else {
2703 err = -EINVAL;
2704 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2705 goto out;
2706 if (msg->msg_namelen < (saddr->sll_halen
2707 + offsetof(struct sockaddr_ll,
2708 sll_addr)))
2709 goto out;
2710 proto = saddr->sll_protocol;
2711 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2712 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2713 if (dev && msg->msg_namelen < dev->addr_len +
2714 offsetof(struct sockaddr_ll, sll_addr))
2715 goto out_put;
2716 addr = saddr->sll_addr;
2717 }
2718 }
2719
2720 err = -ENXIO;
2721 if (unlikely(dev == NULL))
2722 goto out;
2723 err = -ENETDOWN;
2724 if (unlikely(!(dev->flags & IFF_UP)))
2725 goto out_put;
2726
2727 sockcm_init(&sockc, &po->sk);
2728 if (msg->msg_controllen) {
2729 err = sock_cmsg_send(&po->sk, msg, &sockc);
2730 if (unlikely(err))
2731 goto out_put;
2732 }
2733
2734 if (po->sk.sk_socket->type == SOCK_RAW)
2735 reserve = dev->hard_header_len;
2736 size_max = po->tx_ring.frame_size
2737 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2738
2739 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2740 size_max = dev->mtu + reserve + VLAN_HLEN;
2741
2742 reinit_completion(&po->skb_completion);
2743
2744 do {
2745 ph = packet_current_frame(po, &po->tx_ring,
2746 TP_STATUS_SEND_REQUEST);
2747 if (unlikely(ph == NULL)) {
2748 if (need_wait && skb) {
2749 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2750 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2751 if (timeo <= 0) {
2752 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2753 goto out_put;
2754 }
2755 }
2756 /* check for additional frames */
2757 continue;
2758 }
2759
2760 skb = NULL;
2761 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2762 if (tp_len < 0)
2763 goto tpacket_error;
2764
2765 status = TP_STATUS_SEND_REQUEST;
2766 hlen = LL_RESERVED_SPACE(dev);
2767 tlen = dev->needed_tailroom;
2768 if (po->has_vnet_hdr) {
2769 vnet_hdr = data;
2770 data += sizeof(*vnet_hdr);
2771 tp_len -= sizeof(*vnet_hdr);
2772 if (tp_len < 0 ||
2773 __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2774 tp_len = -EINVAL;
2775 goto tpacket_error;
2776 }
2777 copylen = __virtio16_to_cpu(vio_le(),
2778 vnet_hdr->hdr_len);
2779 }
2780 copylen = max_t(int, copylen, dev->hard_header_len);
2781 skb = sock_alloc_send_skb(&po->sk,
2782 hlen + tlen + sizeof(struct sockaddr_ll) +
2783 (copylen - dev->hard_header_len),
2784 !need_wait, &err);
2785
2786 if (unlikely(skb == NULL)) {
2787 /* we assume the socket was initially writeable ... */
2788 if (likely(len_sum > 0))
2789 err = len_sum;
2790 goto out_status;
2791 }
2792 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2793 addr, hlen, copylen, &sockc);
2794 if (likely(tp_len >= 0) &&
2795 tp_len > dev->mtu + reserve &&
2796 !po->has_vnet_hdr &&
2797 !packet_extra_vlan_len_allowed(dev, skb))
2798 tp_len = -EMSGSIZE;
2799
2800 if (unlikely(tp_len < 0)) {
2801 tpacket_error:
2802 if (po->tp_loss) {
2803 __packet_set_status(po, ph,
2804 TP_STATUS_AVAILABLE);
2805 packet_increment_head(&po->tx_ring);
2806 kfree_skb(skb);
2807 continue;
2808 } else {
2809 status = TP_STATUS_WRONG_FORMAT;
2810 err = tp_len;
2811 goto out_status;
2812 }
2813 }
2814
2815 if (po->has_vnet_hdr) {
2816 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2817 tp_len = -EINVAL;
2818 goto tpacket_error;
2819 }
2820 virtio_net_hdr_set_proto(skb, vnet_hdr);
2821 }
2822
2823 skb->destructor = tpacket_destruct_skb;
2824 __packet_set_status(po, ph, TP_STATUS_SENDING);
2825 packet_inc_pending(&po->tx_ring);
2826
2827 status = TP_STATUS_SEND_REQUEST;
2828 err = po->xmit(skb);
2829 if (unlikely(err != 0)) {
2830 if (err > 0)
2831 err = net_xmit_errno(err);
2832 if (err && __packet_get_status(po, ph) ==
2833 TP_STATUS_AVAILABLE) {
2834 /* skb was destructed already */
2835 skb = NULL;
2836 goto out_status;
2837 }
2838 /*
2839 * skb was dropped but not destructed yet;
2840 * let's treat it like congestion or err < 0
2841 */
2842 err = 0;
2843 }
2844 packet_increment_head(&po->tx_ring);
2845 len_sum += tp_len;
2846 } while (likely((ph != NULL) ||
2847 /* Note: packet_read_pending() might be slow if we have
2848 * to call it as it's per_cpu variable, but in fast-path
2849 * we already short-circuit the loop with the first
2850 * condition, and luckily don't have to go that path
2851 * anyway.
2852 */
2853 (need_wait && packet_read_pending(&po->tx_ring))));
2854
2855 err = len_sum;
2856 goto out_put;
2857
2858 out_status:
2859 __packet_set_status(po, ph, status);
2860 kfree_skb(skb);
2861 out_put:
2862 dev_put(dev);
2863 out:
2864 mutex_unlock(&po->pg_vec_lock);
2865 return err;
2866 }
2867
packet_alloc_skb(struct sock * sk,size_t prepad,size_t reserve,size_t len,size_t linear,int noblock,int * err)2868 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2869 size_t reserve, size_t len,
2870 size_t linear, int noblock,
2871 int *err)
2872 {
2873 struct sk_buff *skb;
2874
2875 /* Under a page? Don't bother with paged skb. */
2876 if (prepad + len < PAGE_SIZE || !linear)
2877 linear = len;
2878
2879 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2880 err, 0);
2881 if (!skb)
2882 return NULL;
2883
2884 skb_reserve(skb, reserve);
2885 skb_put(skb, linear);
2886 skb->data_len = len - linear;
2887 skb->len += len - linear;
2888
2889 return skb;
2890 }
2891
packet_snd(struct socket * sock,struct msghdr * msg,size_t len)2892 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2893 {
2894 struct sock *sk = sock->sk;
2895 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2896 struct sk_buff *skb;
2897 struct net_device *dev;
2898 __be16 proto;
2899 unsigned char *addr = NULL;
2900 int err, reserve = 0;
2901 struct sockcm_cookie sockc;
2902 struct virtio_net_hdr vnet_hdr = { 0 };
2903 int offset = 0;
2904 struct packet_sock *po = pkt_sk(sk);
2905 bool has_vnet_hdr = false;
2906 int hlen, tlen, linear;
2907 int extra_len = 0;
2908
2909 /*
2910 * Get and verify the address.
2911 */
2912
2913 if (likely(saddr == NULL)) {
2914 dev = packet_cached_dev_get(po);
2915 proto = READ_ONCE(po->num);
2916 } else {
2917 err = -EINVAL;
2918 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2919 goto out;
2920 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2921 goto out;
2922 proto = saddr->sll_protocol;
2923 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2924 if (sock->type == SOCK_DGRAM) {
2925 if (dev && msg->msg_namelen < dev->addr_len +
2926 offsetof(struct sockaddr_ll, sll_addr))
2927 goto out_unlock;
2928 addr = saddr->sll_addr;
2929 }
2930 }
2931
2932 err = -ENXIO;
2933 if (unlikely(dev == NULL))
2934 goto out_unlock;
2935 err = -ENETDOWN;
2936 if (unlikely(!(dev->flags & IFF_UP)))
2937 goto out_unlock;
2938
2939 sockcm_init(&sockc, sk);
2940 sockc.mark = sk->sk_mark;
2941 if (msg->msg_controllen) {
2942 err = sock_cmsg_send(sk, msg, &sockc);
2943 if (unlikely(err))
2944 goto out_unlock;
2945 }
2946
2947 if (sock->type == SOCK_RAW)
2948 reserve = dev->hard_header_len;
2949 if (po->has_vnet_hdr) {
2950 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2951 if (err)
2952 goto out_unlock;
2953 has_vnet_hdr = true;
2954 }
2955
2956 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2957 if (!netif_supports_nofcs(dev)) {
2958 err = -EPROTONOSUPPORT;
2959 goto out_unlock;
2960 }
2961 extra_len = 4; /* We're doing our own CRC */
2962 }
2963
2964 err = -EMSGSIZE;
2965 if (!vnet_hdr.gso_type &&
2966 (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2967 goto out_unlock;
2968
2969 err = -ENOBUFS;
2970 hlen = LL_RESERVED_SPACE(dev);
2971 tlen = dev->needed_tailroom;
2972 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2973 linear = max(linear, min_t(int, len, dev->hard_header_len));
2974 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2975 msg->msg_flags & MSG_DONTWAIT, &err);
2976 if (skb == NULL)
2977 goto out_unlock;
2978
2979 skb_reset_network_header(skb);
2980
2981 err = -EINVAL;
2982 if (sock->type == SOCK_DGRAM) {
2983 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2984 if (unlikely(offset < 0))
2985 goto out_free;
2986 } else if (reserve) {
2987 skb_reserve(skb, -reserve);
2988 if (len < reserve + sizeof(struct ipv6hdr) &&
2989 dev->min_header_len != dev->hard_header_len)
2990 skb_reset_network_header(skb);
2991 }
2992
2993 /* Returns -EFAULT on error */
2994 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2995 if (err)
2996 goto out_free;
2997
2998 if ((sock->type == SOCK_RAW &&
2999 !dev_validate_header(dev, skb->data, len)) || !skb->len) {
3000 err = -EINVAL;
3001 goto out_free;
3002 }
3003
3004 skb_setup_tx_timestamp(skb, sockc.tsflags);
3005
3006 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
3007 !packet_extra_vlan_len_allowed(dev, skb)) {
3008 err = -EMSGSIZE;
3009 goto out_free;
3010 }
3011
3012 skb->protocol = proto;
3013 skb->dev = dev;
3014 skb->priority = sk->sk_priority;
3015 skb->mark = sockc.mark;
3016 skb->tstamp = sockc.transmit_time;
3017
3018 if (unlikely(extra_len == 4))
3019 skb->no_fcs = 1;
3020
3021 packet_parse_headers(skb, sock);
3022
3023 if (has_vnet_hdr) {
3024 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
3025 if (err)
3026 goto out_free;
3027 len += sizeof(vnet_hdr);
3028 virtio_net_hdr_set_proto(skb, &vnet_hdr);
3029 }
3030
3031 err = po->xmit(skb);
3032 if (unlikely(err != 0)) {
3033 if (err > 0)
3034 err = net_xmit_errno(err);
3035 if (err)
3036 goto out_unlock;
3037 }
3038
3039 dev_put(dev);
3040
3041 return len;
3042
3043 out_free:
3044 kfree_skb(skb);
3045 out_unlock:
3046 if (dev)
3047 dev_put(dev);
3048 out:
3049 return err;
3050 }
3051
packet_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)3052 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3053 {
3054 struct sock *sk = sock->sk;
3055 struct packet_sock *po = pkt_sk(sk);
3056
3057 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
3058 * tpacket_snd() will redo the check safely.
3059 */
3060 if (data_race(po->tx_ring.pg_vec))
3061 return tpacket_snd(po, msg);
3062
3063 return packet_snd(sock, msg, len);
3064 }
3065
3066 /*
3067 * Close a PACKET socket. This is fairly simple. We immediately go
3068 * to 'closed' state and remove our protocol entry in the device list.
3069 */
3070
packet_release(struct socket * sock)3071 static int packet_release(struct socket *sock)
3072 {
3073 struct sock *sk = sock->sk;
3074 struct packet_sock *po;
3075 struct packet_fanout *f;
3076 struct net *net;
3077 union tpacket_req_u req_u;
3078
3079 if (!sk)
3080 return 0;
3081
3082 net = sock_net(sk);
3083 po = pkt_sk(sk);
3084
3085 mutex_lock(&net->packet.sklist_lock);
3086 sk_del_node_init_rcu(sk);
3087 mutex_unlock(&net->packet.sklist_lock);
3088
3089 preempt_disable();
3090 sock_prot_inuse_add(net, sk->sk_prot, -1);
3091 preempt_enable();
3092
3093 spin_lock(&po->bind_lock);
3094 unregister_prot_hook(sk, false);
3095 packet_cached_dev_reset(po);
3096
3097 if (po->prot_hook.dev) {
3098 dev_put(po->prot_hook.dev);
3099 po->prot_hook.dev = NULL;
3100 }
3101 spin_unlock(&po->bind_lock);
3102
3103 packet_flush_mclist(sk);
3104
3105 lock_sock(sk);
3106 if (po->rx_ring.pg_vec) {
3107 memset(&req_u, 0, sizeof(req_u));
3108 packet_set_ring(sk, &req_u, 1, 0);
3109 }
3110
3111 if (po->tx_ring.pg_vec) {
3112 memset(&req_u, 0, sizeof(req_u));
3113 packet_set_ring(sk, &req_u, 1, 1);
3114 }
3115 release_sock(sk);
3116
3117 f = fanout_release(sk);
3118
3119 synchronize_net();
3120
3121 kfree(po->rollover);
3122 if (f) {
3123 fanout_release_data(f);
3124 kvfree(f);
3125 }
3126 /*
3127 * Now the socket is dead. No more input will appear.
3128 */
3129 sock_orphan(sk);
3130 sock->sk = NULL;
3131
3132 /* Purge queues */
3133
3134 skb_queue_purge(&sk->sk_receive_queue);
3135 packet_free_pending(po);
3136 sk_refcnt_debug_release(sk);
3137
3138 sock_put(sk);
3139 return 0;
3140 }
3141
3142 /*
3143 * Attach a packet hook.
3144 */
3145
packet_do_bind(struct sock * sk,const char * name,int ifindex,__be16 proto)3146 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3147 __be16 proto)
3148 {
3149 struct packet_sock *po = pkt_sk(sk);
3150 struct net_device *dev_curr;
3151 __be16 proto_curr;
3152 bool need_rehook;
3153 struct net_device *dev = NULL;
3154 int ret = 0;
3155 bool unlisted = false;
3156
3157 lock_sock(sk);
3158 spin_lock(&po->bind_lock);
3159 rcu_read_lock();
3160
3161 if (po->fanout) {
3162 ret = -EINVAL;
3163 goto out_unlock;
3164 }
3165
3166 if (name) {
3167 dev = dev_get_by_name_rcu(sock_net(sk), name);
3168 if (!dev) {
3169 ret = -ENODEV;
3170 goto out_unlock;
3171 }
3172 } else if (ifindex) {
3173 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3174 if (!dev) {
3175 ret = -ENODEV;
3176 goto out_unlock;
3177 }
3178 }
3179
3180 if (dev)
3181 dev_hold(dev);
3182
3183 proto_curr = po->prot_hook.type;
3184 dev_curr = po->prot_hook.dev;
3185
3186 need_rehook = proto_curr != proto || dev_curr != dev;
3187
3188 if (need_rehook) {
3189 if (po->running) {
3190 rcu_read_unlock();
3191 /* prevents packet_notifier() from calling
3192 * register_prot_hook()
3193 */
3194 WRITE_ONCE(po->num, 0);
3195 __unregister_prot_hook(sk, true);
3196 rcu_read_lock();
3197 dev_curr = po->prot_hook.dev;
3198 if (dev)
3199 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3200 dev->ifindex);
3201 }
3202
3203 BUG_ON(po->running);
3204 WRITE_ONCE(po->num, proto);
3205 po->prot_hook.type = proto;
3206
3207 if (unlikely(unlisted)) {
3208 dev_put(dev);
3209 po->prot_hook.dev = NULL;
3210 WRITE_ONCE(po->ifindex, -1);
3211 packet_cached_dev_reset(po);
3212 } else {
3213 po->prot_hook.dev = dev;
3214 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
3215 packet_cached_dev_assign(po, dev);
3216 }
3217 }
3218 if (dev_curr)
3219 dev_put(dev_curr);
3220
3221 if (proto == 0 || !need_rehook)
3222 goto out_unlock;
3223
3224 if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3225 register_prot_hook(sk);
3226 } else {
3227 sk->sk_err = ENETDOWN;
3228 if (!sock_flag(sk, SOCK_DEAD))
3229 sk->sk_error_report(sk);
3230 }
3231
3232 out_unlock:
3233 rcu_read_unlock();
3234 spin_unlock(&po->bind_lock);
3235 release_sock(sk);
3236 return ret;
3237 }
3238
3239 /*
3240 * Bind a packet socket to a device
3241 */
3242
packet_bind_spkt(struct socket * sock,struct sockaddr * uaddr,int addr_len)3243 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3244 int addr_len)
3245 {
3246 struct sock *sk = sock->sk;
3247 char name[sizeof(uaddr->sa_data) + 1];
3248
3249 /*
3250 * Check legality
3251 */
3252
3253 if (addr_len != sizeof(struct sockaddr))
3254 return -EINVAL;
3255 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3256 * zero-terminated.
3257 */
3258 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3259 name[sizeof(uaddr->sa_data)] = 0;
3260
3261 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3262 }
3263
packet_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)3264 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3265 {
3266 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3267 struct sock *sk = sock->sk;
3268
3269 /*
3270 * Check legality
3271 */
3272
3273 if (addr_len < sizeof(struct sockaddr_ll))
3274 return -EINVAL;
3275 if (sll->sll_family != AF_PACKET)
3276 return -EINVAL;
3277
3278 return packet_do_bind(sk, NULL, sll->sll_ifindex,
3279 sll->sll_protocol ? : pkt_sk(sk)->num);
3280 }
3281
3282 static struct proto packet_proto = {
3283 .name = "PACKET",
3284 .owner = THIS_MODULE,
3285 .obj_size = sizeof(struct packet_sock),
3286 };
3287
3288 /*
3289 * Create a packet of type SOCK_PACKET.
3290 */
3291
packet_create(struct net * net,struct socket * sock,int protocol,int kern)3292 static int packet_create(struct net *net, struct socket *sock, int protocol,
3293 int kern)
3294 {
3295 struct sock *sk;
3296 struct packet_sock *po;
3297 __be16 proto = (__force __be16)protocol; /* weird, but documented */
3298 int err;
3299
3300 if (!ns_capable(net->user_ns, CAP_NET_RAW))
3301 return -EPERM;
3302 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3303 sock->type != SOCK_PACKET)
3304 return -ESOCKTNOSUPPORT;
3305
3306 sock->state = SS_UNCONNECTED;
3307
3308 err = -ENOBUFS;
3309 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3310 if (sk == NULL)
3311 goto out;
3312
3313 sock->ops = &packet_ops;
3314 if (sock->type == SOCK_PACKET)
3315 sock->ops = &packet_ops_spkt;
3316
3317 sock_init_data(sock, sk);
3318
3319 po = pkt_sk(sk);
3320 init_completion(&po->skb_completion);
3321 sk->sk_family = PF_PACKET;
3322 po->num = proto;
3323 po->xmit = dev_queue_xmit;
3324
3325 err = packet_alloc_pending(po);
3326 if (err)
3327 goto out2;
3328
3329 packet_cached_dev_reset(po);
3330
3331 sk->sk_destruct = packet_sock_destruct;
3332 sk_refcnt_debug_inc(sk);
3333
3334 /*
3335 * Attach a protocol block
3336 */
3337
3338 spin_lock_init(&po->bind_lock);
3339 mutex_init(&po->pg_vec_lock);
3340 po->rollover = NULL;
3341 po->prot_hook.func = packet_rcv;
3342
3343 if (sock->type == SOCK_PACKET)
3344 po->prot_hook.func = packet_rcv_spkt;
3345
3346 po->prot_hook.af_packet_priv = sk;
3347 po->prot_hook.af_packet_net = sock_net(sk);
3348
3349 if (proto) {
3350 po->prot_hook.type = proto;
3351 __register_prot_hook(sk);
3352 }
3353
3354 mutex_lock(&net->packet.sklist_lock);
3355 sk_add_node_tail_rcu(sk, &net->packet.sklist);
3356 mutex_unlock(&net->packet.sklist_lock);
3357
3358 preempt_disable();
3359 sock_prot_inuse_add(net, &packet_proto, 1);
3360 preempt_enable();
3361
3362 return 0;
3363 out2:
3364 sk_free(sk);
3365 out:
3366 return err;
3367 }
3368
3369 /*
3370 * Pull a packet from our receive queue and hand it to the user.
3371 * If necessary we block.
3372 */
3373
packet_recvmsg(struct socket * sock,struct msghdr * msg,size_t len,int flags)3374 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3375 int flags)
3376 {
3377 struct sock *sk = sock->sk;
3378 struct sk_buff *skb;
3379 int copied, err;
3380 int vnet_hdr_len = 0;
3381 unsigned int origlen = 0;
3382
3383 err = -EINVAL;
3384 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3385 goto out;
3386
3387 #if 0
3388 /* What error should we return now? EUNATTACH? */
3389 if (pkt_sk(sk)->ifindex < 0)
3390 return -ENODEV;
3391 #endif
3392
3393 if (flags & MSG_ERRQUEUE) {
3394 err = sock_recv_errqueue(sk, msg, len,
3395 SOL_PACKET, PACKET_TX_TIMESTAMP);
3396 goto out;
3397 }
3398
3399 /*
3400 * Call the generic datagram receiver. This handles all sorts
3401 * of horrible races and re-entrancy so we can forget about it
3402 * in the protocol layers.
3403 *
3404 * Now it will return ENETDOWN, if device have just gone down,
3405 * but then it will block.
3406 */
3407
3408 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3409
3410 /*
3411 * An error occurred so return it. Because skb_recv_datagram()
3412 * handles the blocking we don't see and worry about blocking
3413 * retries.
3414 */
3415
3416 if (skb == NULL)
3417 goto out;
3418
3419 packet_rcv_try_clear_pressure(pkt_sk(sk));
3420
3421 if (pkt_sk(sk)->has_vnet_hdr) {
3422 err = packet_rcv_vnet(msg, skb, &len);
3423 if (err)
3424 goto out_free;
3425 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3426 }
3427
3428 /* You lose any data beyond the buffer you gave. If it worries
3429 * a user program they can ask the device for its MTU
3430 * anyway.
3431 */
3432 copied = skb->len;
3433 if (copied > len) {
3434 copied = len;
3435 msg->msg_flags |= MSG_TRUNC;
3436 }
3437
3438 err = skb_copy_datagram_msg(skb, 0, msg, copied);
3439 if (err)
3440 goto out_free;
3441
3442 if (sock->type != SOCK_PACKET) {
3443 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3444
3445 /* Original length was stored in sockaddr_ll fields */
3446 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3447 sll->sll_family = AF_PACKET;
3448 sll->sll_protocol = skb->protocol;
3449 }
3450
3451 sock_recv_ts_and_drops(msg, sk, skb);
3452
3453 if (msg->msg_name) {
3454 const size_t max_len = min(sizeof(skb->cb),
3455 sizeof(struct sockaddr_storage));
3456 int copy_len;
3457
3458 /* If the address length field is there to be filled
3459 * in, we fill it in now.
3460 */
3461 if (sock->type == SOCK_PACKET) {
3462 __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3463 msg->msg_namelen = sizeof(struct sockaddr_pkt);
3464 copy_len = msg->msg_namelen;
3465 } else {
3466 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3467
3468 msg->msg_namelen = sll->sll_halen +
3469 offsetof(struct sockaddr_ll, sll_addr);
3470 copy_len = msg->msg_namelen;
3471 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3472 memset(msg->msg_name +
3473 offsetof(struct sockaddr_ll, sll_addr),
3474 0, sizeof(sll->sll_addr));
3475 msg->msg_namelen = sizeof(struct sockaddr_ll);
3476 }
3477 }
3478 if (WARN_ON_ONCE(copy_len > max_len)) {
3479 copy_len = max_len;
3480 msg->msg_namelen = copy_len;
3481 }
3482 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3483 }
3484
3485 if (pkt_sk(sk)->auxdata) {
3486 struct tpacket_auxdata aux;
3487
3488 aux.tp_status = TP_STATUS_USER;
3489 if (skb->ip_summed == CHECKSUM_PARTIAL)
3490 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3491 else if (skb->pkt_type != PACKET_OUTGOING &&
3492 skb_csum_unnecessary(skb))
3493 aux.tp_status |= TP_STATUS_CSUM_VALID;
3494
3495 aux.tp_len = origlen;
3496 aux.tp_snaplen = skb->len;
3497 aux.tp_mac = 0;
3498 aux.tp_net = skb_network_offset(skb);
3499 if (skb_vlan_tag_present(skb)) {
3500 aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3501 aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3502 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3503 } else {
3504 aux.tp_vlan_tci = 0;
3505 aux.tp_vlan_tpid = 0;
3506 }
3507 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3508 }
3509
3510 /*
3511 * Free or return the buffer as appropriate. Again this
3512 * hides all the races and re-entrancy issues from us.
3513 */
3514 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3515
3516 out_free:
3517 skb_free_datagram(sk, skb);
3518 out:
3519 return err;
3520 }
3521
packet_getname_spkt(struct socket * sock,struct sockaddr * uaddr,int peer)3522 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3523 int peer)
3524 {
3525 struct net_device *dev;
3526 struct sock *sk = sock->sk;
3527
3528 if (peer)
3529 return -EOPNOTSUPP;
3530
3531 uaddr->sa_family = AF_PACKET;
3532 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3533 rcu_read_lock();
3534 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
3535 if (dev)
3536 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3537 rcu_read_unlock();
3538
3539 return sizeof(*uaddr);
3540 }
3541
packet_getname(struct socket * sock,struct sockaddr * uaddr,int peer)3542 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3543 int peer)
3544 {
3545 struct net_device *dev;
3546 struct sock *sk = sock->sk;
3547 struct packet_sock *po = pkt_sk(sk);
3548 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3549 int ifindex;
3550
3551 if (peer)
3552 return -EOPNOTSUPP;
3553
3554 ifindex = READ_ONCE(po->ifindex);
3555 sll->sll_family = AF_PACKET;
3556 sll->sll_ifindex = ifindex;
3557 sll->sll_protocol = READ_ONCE(po->num);
3558 sll->sll_pkttype = 0;
3559 rcu_read_lock();
3560 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3561 if (dev) {
3562 sll->sll_hatype = dev->type;
3563 sll->sll_halen = dev->addr_len;
3564 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3565 } else {
3566 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
3567 sll->sll_halen = 0;
3568 }
3569 rcu_read_unlock();
3570
3571 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3572 }
3573
packet_dev_mc(struct net_device * dev,struct packet_mclist * i,int what)3574 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3575 int what)
3576 {
3577 switch (i->type) {
3578 case PACKET_MR_MULTICAST:
3579 if (i->alen != dev->addr_len)
3580 return -EINVAL;
3581 if (what > 0)
3582 return dev_mc_add(dev, i->addr);
3583 else
3584 return dev_mc_del(dev, i->addr);
3585 break;
3586 case PACKET_MR_PROMISC:
3587 return dev_set_promiscuity(dev, what);
3588 case PACKET_MR_ALLMULTI:
3589 return dev_set_allmulti(dev, what);
3590 case PACKET_MR_UNICAST:
3591 if (i->alen != dev->addr_len)
3592 return -EINVAL;
3593 if (what > 0)
3594 return dev_uc_add(dev, i->addr);
3595 else
3596 return dev_uc_del(dev, i->addr);
3597 break;
3598 default:
3599 break;
3600 }
3601 return 0;
3602 }
3603
packet_dev_mclist_delete(struct net_device * dev,struct packet_mclist ** mlp)3604 static void packet_dev_mclist_delete(struct net_device *dev,
3605 struct packet_mclist **mlp)
3606 {
3607 struct packet_mclist *ml;
3608
3609 while ((ml = *mlp) != NULL) {
3610 if (ml->ifindex == dev->ifindex) {
3611 packet_dev_mc(dev, ml, -1);
3612 *mlp = ml->next;
3613 kfree(ml);
3614 } else
3615 mlp = &ml->next;
3616 }
3617 }
3618
packet_mc_add(struct sock * sk,struct packet_mreq_max * mreq)3619 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3620 {
3621 struct packet_sock *po = pkt_sk(sk);
3622 struct packet_mclist *ml, *i;
3623 struct net_device *dev;
3624 int err;
3625
3626 rtnl_lock();
3627
3628 err = -ENODEV;
3629 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3630 if (!dev)
3631 goto done;
3632
3633 err = -EINVAL;
3634 if (mreq->mr_alen > dev->addr_len)
3635 goto done;
3636
3637 err = -ENOBUFS;
3638 i = kmalloc(sizeof(*i), GFP_KERNEL);
3639 if (i == NULL)
3640 goto done;
3641
3642 err = 0;
3643 for (ml = po->mclist; ml; ml = ml->next) {
3644 if (ml->ifindex == mreq->mr_ifindex &&
3645 ml->type == mreq->mr_type &&
3646 ml->alen == mreq->mr_alen &&
3647 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3648 ml->count++;
3649 /* Free the new element ... */
3650 kfree(i);
3651 goto done;
3652 }
3653 }
3654
3655 i->type = mreq->mr_type;
3656 i->ifindex = mreq->mr_ifindex;
3657 i->alen = mreq->mr_alen;
3658 memcpy(i->addr, mreq->mr_address, i->alen);
3659 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3660 i->count = 1;
3661 i->next = po->mclist;
3662 po->mclist = i;
3663 err = packet_dev_mc(dev, i, 1);
3664 if (err) {
3665 po->mclist = i->next;
3666 kfree(i);
3667 }
3668
3669 done:
3670 rtnl_unlock();
3671 return err;
3672 }
3673
packet_mc_drop(struct sock * sk,struct packet_mreq_max * mreq)3674 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3675 {
3676 struct packet_mclist *ml, **mlp;
3677
3678 rtnl_lock();
3679
3680 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3681 if (ml->ifindex == mreq->mr_ifindex &&
3682 ml->type == mreq->mr_type &&
3683 ml->alen == mreq->mr_alen &&
3684 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3685 if (--ml->count == 0) {
3686 struct net_device *dev;
3687 *mlp = ml->next;
3688 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3689 if (dev)
3690 packet_dev_mc(dev, ml, -1);
3691 kfree(ml);
3692 }
3693 break;
3694 }
3695 }
3696 rtnl_unlock();
3697 return 0;
3698 }
3699
packet_flush_mclist(struct sock * sk)3700 static void packet_flush_mclist(struct sock *sk)
3701 {
3702 struct packet_sock *po = pkt_sk(sk);
3703 struct packet_mclist *ml;
3704
3705 if (!po->mclist)
3706 return;
3707
3708 rtnl_lock();
3709 while ((ml = po->mclist) != NULL) {
3710 struct net_device *dev;
3711
3712 po->mclist = ml->next;
3713 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3714 if (dev != NULL)
3715 packet_dev_mc(dev, ml, -1);
3716 kfree(ml);
3717 }
3718 rtnl_unlock();
3719 }
3720
3721 static int
packet_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)3722 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3723 unsigned int optlen)
3724 {
3725 struct sock *sk = sock->sk;
3726 struct packet_sock *po = pkt_sk(sk);
3727 int ret;
3728
3729 if (level != SOL_PACKET)
3730 return -ENOPROTOOPT;
3731
3732 switch (optname) {
3733 case PACKET_ADD_MEMBERSHIP:
3734 case PACKET_DROP_MEMBERSHIP:
3735 {
3736 struct packet_mreq_max mreq;
3737 int len = optlen;
3738 memset(&mreq, 0, sizeof(mreq));
3739 if (len < sizeof(struct packet_mreq))
3740 return -EINVAL;
3741 if (len > sizeof(mreq))
3742 len = sizeof(mreq);
3743 if (copy_from_sockptr(&mreq, optval, len))
3744 return -EFAULT;
3745 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3746 return -EINVAL;
3747 if (optname == PACKET_ADD_MEMBERSHIP)
3748 ret = packet_mc_add(sk, &mreq);
3749 else
3750 ret = packet_mc_drop(sk, &mreq);
3751 return ret;
3752 }
3753
3754 case PACKET_RX_RING:
3755 case PACKET_TX_RING:
3756 {
3757 union tpacket_req_u req_u;
3758 int len;
3759
3760 lock_sock(sk);
3761 switch (po->tp_version) {
3762 case TPACKET_V1:
3763 case TPACKET_V2:
3764 len = sizeof(req_u.req);
3765 break;
3766 case TPACKET_V3:
3767 default:
3768 len = sizeof(req_u.req3);
3769 break;
3770 }
3771 if (optlen < len) {
3772 ret = -EINVAL;
3773 } else {
3774 if (copy_from_sockptr(&req_u.req, optval, len))
3775 ret = -EFAULT;
3776 else
3777 ret = packet_set_ring(sk, &req_u, 0,
3778 optname == PACKET_TX_RING);
3779 }
3780 release_sock(sk);
3781 return ret;
3782 }
3783 case PACKET_COPY_THRESH:
3784 {
3785 int val;
3786
3787 if (optlen != sizeof(val))
3788 return -EINVAL;
3789 if (copy_from_sockptr(&val, optval, sizeof(val)))
3790 return -EFAULT;
3791
3792 pkt_sk(sk)->copy_thresh = val;
3793 return 0;
3794 }
3795 case PACKET_VERSION:
3796 {
3797 int val;
3798
3799 if (optlen != sizeof(val))
3800 return -EINVAL;
3801 if (copy_from_sockptr(&val, optval, sizeof(val)))
3802 return -EFAULT;
3803 switch (val) {
3804 case TPACKET_V1:
3805 case TPACKET_V2:
3806 case TPACKET_V3:
3807 break;
3808 default:
3809 return -EINVAL;
3810 }
3811 lock_sock(sk);
3812 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3813 ret = -EBUSY;
3814 } else {
3815 po->tp_version = val;
3816 ret = 0;
3817 }
3818 release_sock(sk);
3819 return ret;
3820 }
3821 case PACKET_RESERVE:
3822 {
3823 unsigned int val;
3824
3825 if (optlen != sizeof(val))
3826 return -EINVAL;
3827 if (copy_from_sockptr(&val, optval, sizeof(val)))
3828 return -EFAULT;
3829 if (val > INT_MAX)
3830 return -EINVAL;
3831 lock_sock(sk);
3832 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3833 ret = -EBUSY;
3834 } else {
3835 po->tp_reserve = val;
3836 ret = 0;
3837 }
3838 release_sock(sk);
3839 return ret;
3840 }
3841 case PACKET_LOSS:
3842 {
3843 unsigned int val;
3844
3845 if (optlen != sizeof(val))
3846 return -EINVAL;
3847 if (copy_from_sockptr(&val, optval, sizeof(val)))
3848 return -EFAULT;
3849
3850 lock_sock(sk);
3851 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3852 ret = -EBUSY;
3853 } else {
3854 po->tp_loss = !!val;
3855 ret = 0;
3856 }
3857 release_sock(sk);
3858 return ret;
3859 }
3860 case PACKET_AUXDATA:
3861 {
3862 int val;
3863
3864 if (optlen < sizeof(val))
3865 return -EINVAL;
3866 if (copy_from_sockptr(&val, optval, sizeof(val)))
3867 return -EFAULT;
3868
3869 lock_sock(sk);
3870 po->auxdata = !!val;
3871 release_sock(sk);
3872 return 0;
3873 }
3874 case PACKET_ORIGDEV:
3875 {
3876 int val;
3877
3878 if (optlen < sizeof(val))
3879 return -EINVAL;
3880 if (copy_from_sockptr(&val, optval, sizeof(val)))
3881 return -EFAULT;
3882
3883 lock_sock(sk);
3884 po->origdev = !!val;
3885 release_sock(sk);
3886 return 0;
3887 }
3888 case PACKET_VNET_HDR:
3889 {
3890 int val;
3891
3892 if (sock->type != SOCK_RAW)
3893 return -EINVAL;
3894 if (optlen < sizeof(val))
3895 return -EINVAL;
3896 if (copy_from_sockptr(&val, optval, sizeof(val)))
3897 return -EFAULT;
3898
3899 lock_sock(sk);
3900 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3901 ret = -EBUSY;
3902 } else {
3903 po->has_vnet_hdr = !!val;
3904 ret = 0;
3905 }
3906 release_sock(sk);
3907 return ret;
3908 }
3909 case PACKET_TIMESTAMP:
3910 {
3911 int val;
3912
3913 if (optlen != sizeof(val))
3914 return -EINVAL;
3915 if (copy_from_sockptr(&val, optval, sizeof(val)))
3916 return -EFAULT;
3917
3918 po->tp_tstamp = val;
3919 return 0;
3920 }
3921 case PACKET_FANOUT:
3922 {
3923 struct fanout_args args = { 0 };
3924
3925 if (optlen != sizeof(int) && optlen != sizeof(args))
3926 return -EINVAL;
3927 if (copy_from_sockptr(&args, optval, optlen))
3928 return -EFAULT;
3929
3930 return fanout_add(sk, &args);
3931 }
3932 case PACKET_FANOUT_DATA:
3933 {
3934 /* Paired with the WRITE_ONCE() in fanout_add() */
3935 if (!READ_ONCE(po->fanout))
3936 return -EINVAL;
3937
3938 return fanout_set_data(po, optval, optlen);
3939 }
3940 case PACKET_IGNORE_OUTGOING:
3941 {
3942 int val;
3943
3944 if (optlen != sizeof(val))
3945 return -EINVAL;
3946 if (copy_from_sockptr(&val, optval, sizeof(val)))
3947 return -EFAULT;
3948 if (val < 0 || val > 1)
3949 return -EINVAL;
3950
3951 po->prot_hook.ignore_outgoing = !!val;
3952 return 0;
3953 }
3954 case PACKET_TX_HAS_OFF:
3955 {
3956 unsigned int val;
3957
3958 if (optlen != sizeof(val))
3959 return -EINVAL;
3960 if (copy_from_sockptr(&val, optval, sizeof(val)))
3961 return -EFAULT;
3962
3963 lock_sock(sk);
3964 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3965 ret = -EBUSY;
3966 } else {
3967 po->tp_tx_has_off = !!val;
3968 ret = 0;
3969 }
3970 release_sock(sk);
3971 return 0;
3972 }
3973 case PACKET_QDISC_BYPASS:
3974 {
3975 int val;
3976
3977 if (optlen != sizeof(val))
3978 return -EINVAL;
3979 if (copy_from_sockptr(&val, optval, sizeof(val)))
3980 return -EFAULT;
3981
3982 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3983 return 0;
3984 }
3985 default:
3986 return -ENOPROTOOPT;
3987 }
3988 }
3989
packet_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)3990 static int packet_getsockopt(struct socket *sock, int level, int optname,
3991 char __user *optval, int __user *optlen)
3992 {
3993 int len;
3994 int val, lv = sizeof(val);
3995 struct sock *sk = sock->sk;
3996 struct packet_sock *po = pkt_sk(sk);
3997 void *data = &val;
3998 union tpacket_stats_u st;
3999 struct tpacket_rollover_stats rstats;
4000 int drops;
4001
4002 if (level != SOL_PACKET)
4003 return -ENOPROTOOPT;
4004
4005 if (get_user(len, optlen))
4006 return -EFAULT;
4007
4008 if (len < 0)
4009 return -EINVAL;
4010
4011 switch (optname) {
4012 case PACKET_STATISTICS:
4013 spin_lock_bh(&sk->sk_receive_queue.lock);
4014 memcpy(&st, &po->stats, sizeof(st));
4015 memset(&po->stats, 0, sizeof(po->stats));
4016 spin_unlock_bh(&sk->sk_receive_queue.lock);
4017 drops = atomic_xchg(&po->tp_drops, 0);
4018
4019 if (po->tp_version == TPACKET_V3) {
4020 lv = sizeof(struct tpacket_stats_v3);
4021 st.stats3.tp_drops = drops;
4022 st.stats3.tp_packets += drops;
4023 data = &st.stats3;
4024 } else {
4025 lv = sizeof(struct tpacket_stats);
4026 st.stats1.tp_drops = drops;
4027 st.stats1.tp_packets += drops;
4028 data = &st.stats1;
4029 }
4030
4031 break;
4032 case PACKET_AUXDATA:
4033 val = po->auxdata;
4034 break;
4035 case PACKET_ORIGDEV:
4036 val = po->origdev;
4037 break;
4038 case PACKET_VNET_HDR:
4039 val = po->has_vnet_hdr;
4040 break;
4041 case PACKET_VERSION:
4042 val = po->tp_version;
4043 break;
4044 case PACKET_HDRLEN:
4045 if (len > sizeof(int))
4046 len = sizeof(int);
4047 if (len < sizeof(int))
4048 return -EINVAL;
4049 if (copy_from_user(&val, optval, len))
4050 return -EFAULT;
4051 switch (val) {
4052 case TPACKET_V1:
4053 val = sizeof(struct tpacket_hdr);
4054 break;
4055 case TPACKET_V2:
4056 val = sizeof(struct tpacket2_hdr);
4057 break;
4058 case TPACKET_V3:
4059 val = sizeof(struct tpacket3_hdr);
4060 break;
4061 default:
4062 return -EINVAL;
4063 }
4064 break;
4065 case PACKET_RESERVE:
4066 val = po->tp_reserve;
4067 break;
4068 case PACKET_LOSS:
4069 val = po->tp_loss;
4070 break;
4071 case PACKET_TIMESTAMP:
4072 val = po->tp_tstamp;
4073 break;
4074 case PACKET_FANOUT:
4075 val = (po->fanout ?
4076 ((u32)po->fanout->id |
4077 ((u32)po->fanout->type << 16) |
4078 ((u32)po->fanout->flags << 24)) :
4079 0);
4080 break;
4081 case PACKET_IGNORE_OUTGOING:
4082 val = po->prot_hook.ignore_outgoing;
4083 break;
4084 case PACKET_ROLLOVER_STATS:
4085 if (!po->rollover)
4086 return -EINVAL;
4087 rstats.tp_all = atomic_long_read(&po->rollover->num);
4088 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4089 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4090 data = &rstats;
4091 lv = sizeof(rstats);
4092 break;
4093 case PACKET_TX_HAS_OFF:
4094 val = po->tp_tx_has_off;
4095 break;
4096 case PACKET_QDISC_BYPASS:
4097 val = packet_use_direct_xmit(po);
4098 break;
4099 default:
4100 return -ENOPROTOOPT;
4101 }
4102
4103 if (len > lv)
4104 len = lv;
4105 if (put_user(len, optlen))
4106 return -EFAULT;
4107 if (copy_to_user(optval, data, len))
4108 return -EFAULT;
4109 return 0;
4110 }
4111
packet_notifier(struct notifier_block * this,unsigned long msg,void * ptr)4112 static int packet_notifier(struct notifier_block *this,
4113 unsigned long msg, void *ptr)
4114 {
4115 struct sock *sk;
4116 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4117 struct net *net = dev_net(dev);
4118
4119 rcu_read_lock();
4120 sk_for_each_rcu(sk, &net->packet.sklist) {
4121 struct packet_sock *po = pkt_sk(sk);
4122
4123 switch (msg) {
4124 case NETDEV_UNREGISTER:
4125 if (po->mclist)
4126 packet_dev_mclist_delete(dev, &po->mclist);
4127 fallthrough;
4128
4129 case NETDEV_DOWN:
4130 if (dev->ifindex == po->ifindex) {
4131 spin_lock(&po->bind_lock);
4132 if (po->running) {
4133 __unregister_prot_hook(sk, false);
4134 sk->sk_err = ENETDOWN;
4135 if (!sock_flag(sk, SOCK_DEAD))
4136 sk->sk_error_report(sk);
4137 }
4138 if (msg == NETDEV_UNREGISTER) {
4139 packet_cached_dev_reset(po);
4140 WRITE_ONCE(po->ifindex, -1);
4141 if (po->prot_hook.dev)
4142 dev_put(po->prot_hook.dev);
4143 po->prot_hook.dev = NULL;
4144 }
4145 spin_unlock(&po->bind_lock);
4146 }
4147 break;
4148 case NETDEV_UP:
4149 if (dev->ifindex == po->ifindex) {
4150 spin_lock(&po->bind_lock);
4151 if (po->num)
4152 register_prot_hook(sk);
4153 spin_unlock(&po->bind_lock);
4154 }
4155 break;
4156 }
4157 }
4158 rcu_read_unlock();
4159 return NOTIFY_DONE;
4160 }
4161
4162
packet_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)4163 static int packet_ioctl(struct socket *sock, unsigned int cmd,
4164 unsigned long arg)
4165 {
4166 struct sock *sk = sock->sk;
4167
4168 switch (cmd) {
4169 case SIOCOUTQ:
4170 {
4171 int amount = sk_wmem_alloc_get(sk);
4172
4173 return put_user(amount, (int __user *)arg);
4174 }
4175 case SIOCINQ:
4176 {
4177 struct sk_buff *skb;
4178 int amount = 0;
4179
4180 spin_lock_bh(&sk->sk_receive_queue.lock);
4181 skb = skb_peek(&sk->sk_receive_queue);
4182 if (skb)
4183 amount = skb->len;
4184 spin_unlock_bh(&sk->sk_receive_queue.lock);
4185 return put_user(amount, (int __user *)arg);
4186 }
4187 #ifdef CONFIG_INET
4188 case SIOCADDRT:
4189 case SIOCDELRT:
4190 case SIOCDARP:
4191 case SIOCGARP:
4192 case SIOCSARP:
4193 case SIOCGIFADDR:
4194 case SIOCSIFADDR:
4195 case SIOCGIFBRDADDR:
4196 case SIOCSIFBRDADDR:
4197 case SIOCGIFNETMASK:
4198 case SIOCSIFNETMASK:
4199 case SIOCGIFDSTADDR:
4200 case SIOCSIFDSTADDR:
4201 case SIOCSIFFLAGS:
4202 return inet_dgram_ops.ioctl(sock, cmd, arg);
4203 #endif
4204
4205 default:
4206 return -ENOIOCTLCMD;
4207 }
4208 return 0;
4209 }
4210
packet_poll(struct file * file,struct socket * sock,poll_table * wait)4211 static __poll_t packet_poll(struct file *file, struct socket *sock,
4212 poll_table *wait)
4213 {
4214 struct sock *sk = sock->sk;
4215 struct packet_sock *po = pkt_sk(sk);
4216 __poll_t mask = datagram_poll(file, sock, wait);
4217
4218 spin_lock_bh(&sk->sk_receive_queue.lock);
4219 if (po->rx_ring.pg_vec) {
4220 if (!packet_previous_rx_frame(po, &po->rx_ring,
4221 TP_STATUS_KERNEL))
4222 mask |= EPOLLIN | EPOLLRDNORM;
4223 }
4224 packet_rcv_try_clear_pressure(po);
4225 spin_unlock_bh(&sk->sk_receive_queue.lock);
4226 spin_lock_bh(&sk->sk_write_queue.lock);
4227 if (po->tx_ring.pg_vec) {
4228 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4229 mask |= EPOLLOUT | EPOLLWRNORM;
4230 }
4231 spin_unlock_bh(&sk->sk_write_queue.lock);
4232 return mask;
4233 }
4234
4235
4236 /* Dirty? Well, I still did not learn better way to account
4237 * for user mmaps.
4238 */
4239
packet_mm_open(struct vm_area_struct * vma)4240 static void packet_mm_open(struct vm_area_struct *vma)
4241 {
4242 struct file *file = vma->vm_file;
4243 struct socket *sock = file->private_data;
4244 struct sock *sk = sock->sk;
4245
4246 if (sk)
4247 atomic_inc(&pkt_sk(sk)->mapped);
4248 }
4249
packet_mm_close(struct vm_area_struct * vma)4250 static void packet_mm_close(struct vm_area_struct *vma)
4251 {
4252 struct file *file = vma->vm_file;
4253 struct socket *sock = file->private_data;
4254 struct sock *sk = sock->sk;
4255
4256 if (sk)
4257 atomic_dec(&pkt_sk(sk)->mapped);
4258 }
4259
4260 static const struct vm_operations_struct packet_mmap_ops = {
4261 .open = packet_mm_open,
4262 .close = packet_mm_close,
4263 };
4264
free_pg_vec(struct pgv * pg_vec,unsigned int order,unsigned int len)4265 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4266 unsigned int len)
4267 {
4268 int i;
4269
4270 for (i = 0; i < len; i++) {
4271 if (likely(pg_vec[i].buffer)) {
4272 if (is_vmalloc_addr(pg_vec[i].buffer))
4273 vfree(pg_vec[i].buffer);
4274 else
4275 free_pages((unsigned long)pg_vec[i].buffer,
4276 order);
4277 pg_vec[i].buffer = NULL;
4278 }
4279 }
4280 kfree(pg_vec);
4281 }
4282
alloc_one_pg_vec_page(unsigned long order)4283 static char *alloc_one_pg_vec_page(unsigned long order)
4284 {
4285 char *buffer;
4286 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4287 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4288
4289 buffer = (char *) __get_free_pages(gfp_flags, order);
4290 if (buffer)
4291 return buffer;
4292
4293 /* __get_free_pages failed, fall back to vmalloc */
4294 buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4295 if (buffer)
4296 return buffer;
4297
4298 /* vmalloc failed, lets dig into swap here */
4299 gfp_flags &= ~__GFP_NORETRY;
4300 buffer = (char *) __get_free_pages(gfp_flags, order);
4301 if (buffer)
4302 return buffer;
4303
4304 /* complete and utter failure */
4305 return NULL;
4306 }
4307
alloc_pg_vec(struct tpacket_req * req,int order)4308 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4309 {
4310 unsigned int block_nr = req->tp_block_nr;
4311 struct pgv *pg_vec;
4312 int i;
4313
4314 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4315 if (unlikely(!pg_vec))
4316 goto out;
4317
4318 for (i = 0; i < block_nr; i++) {
4319 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4320 if (unlikely(!pg_vec[i].buffer))
4321 goto out_free_pgvec;
4322 }
4323
4324 out:
4325 return pg_vec;
4326
4327 out_free_pgvec:
4328 free_pg_vec(pg_vec, order, block_nr);
4329 pg_vec = NULL;
4330 goto out;
4331 }
4332
packet_set_ring(struct sock * sk,union tpacket_req_u * req_u,int closing,int tx_ring)4333 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4334 int closing, int tx_ring)
4335 {
4336 struct pgv *pg_vec = NULL;
4337 struct packet_sock *po = pkt_sk(sk);
4338 unsigned long *rx_owner_map = NULL;
4339 int was_running, order = 0;
4340 struct packet_ring_buffer *rb;
4341 struct sk_buff_head *rb_queue;
4342 __be16 num;
4343 int err;
4344 /* Added to avoid minimal code churn */
4345 struct tpacket_req *req = &req_u->req;
4346
4347 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4348 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4349
4350 err = -EBUSY;
4351 if (!closing) {
4352 if (atomic_read(&po->mapped))
4353 goto out;
4354 if (packet_read_pending(rb))
4355 goto out;
4356 }
4357
4358 if (req->tp_block_nr) {
4359 unsigned int min_frame_size;
4360
4361 /* Sanity tests and some calculations */
4362 err = -EBUSY;
4363 if (unlikely(rb->pg_vec))
4364 goto out;
4365
4366 switch (po->tp_version) {
4367 case TPACKET_V1:
4368 po->tp_hdrlen = TPACKET_HDRLEN;
4369 break;
4370 case TPACKET_V2:
4371 po->tp_hdrlen = TPACKET2_HDRLEN;
4372 break;
4373 case TPACKET_V3:
4374 po->tp_hdrlen = TPACKET3_HDRLEN;
4375 break;
4376 }
4377
4378 err = -EINVAL;
4379 if (unlikely((int)req->tp_block_size <= 0))
4380 goto out;
4381 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4382 goto out;
4383 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4384 if (po->tp_version >= TPACKET_V3 &&
4385 req->tp_block_size <
4386 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4387 goto out;
4388 if (unlikely(req->tp_frame_size < min_frame_size))
4389 goto out;
4390 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4391 goto out;
4392
4393 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4394 if (unlikely(rb->frames_per_block == 0))
4395 goto out;
4396 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4397 goto out;
4398 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4399 req->tp_frame_nr))
4400 goto out;
4401
4402 err = -ENOMEM;
4403 order = get_order(req->tp_block_size);
4404 pg_vec = alloc_pg_vec(req, order);
4405 if (unlikely(!pg_vec))
4406 goto out;
4407 switch (po->tp_version) {
4408 case TPACKET_V3:
4409 /* Block transmit is not supported yet */
4410 if (!tx_ring) {
4411 init_prb_bdqc(po, rb, pg_vec, req_u);
4412 } else {
4413 struct tpacket_req3 *req3 = &req_u->req3;
4414
4415 if (req3->tp_retire_blk_tov ||
4416 req3->tp_sizeof_priv ||
4417 req3->tp_feature_req_word) {
4418 err = -EINVAL;
4419 goto out_free_pg_vec;
4420 }
4421 }
4422 break;
4423 default:
4424 if (!tx_ring) {
4425 rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4426 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4427 if (!rx_owner_map)
4428 goto out_free_pg_vec;
4429 }
4430 break;
4431 }
4432 }
4433 /* Done */
4434 else {
4435 err = -EINVAL;
4436 if (unlikely(req->tp_frame_nr))
4437 goto out;
4438 }
4439
4440
4441 /* Detach socket from network */
4442 spin_lock(&po->bind_lock);
4443 was_running = po->running;
4444 num = po->num;
4445 if (was_running) {
4446 WRITE_ONCE(po->num, 0);
4447 __unregister_prot_hook(sk, false);
4448 }
4449 spin_unlock(&po->bind_lock);
4450
4451 synchronize_net();
4452
4453 err = -EBUSY;
4454 mutex_lock(&po->pg_vec_lock);
4455 if (closing || atomic_read(&po->mapped) == 0) {
4456 err = 0;
4457 spin_lock_bh(&rb_queue->lock);
4458 swap(rb->pg_vec, pg_vec);
4459 if (po->tp_version <= TPACKET_V2)
4460 swap(rb->rx_owner_map, rx_owner_map);
4461 rb->frame_max = (req->tp_frame_nr - 1);
4462 rb->head = 0;
4463 rb->frame_size = req->tp_frame_size;
4464 spin_unlock_bh(&rb_queue->lock);
4465
4466 swap(rb->pg_vec_order, order);
4467 swap(rb->pg_vec_len, req->tp_block_nr);
4468
4469 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4470 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4471 tpacket_rcv : packet_rcv;
4472 skb_queue_purge(rb_queue);
4473 if (atomic_read(&po->mapped))
4474 pr_err("packet_mmap: vma is busy: %d\n",
4475 atomic_read(&po->mapped));
4476 }
4477 mutex_unlock(&po->pg_vec_lock);
4478
4479 spin_lock(&po->bind_lock);
4480 if (was_running) {
4481 WRITE_ONCE(po->num, num);
4482 register_prot_hook(sk);
4483 }
4484 spin_unlock(&po->bind_lock);
4485 if (pg_vec && (po->tp_version > TPACKET_V2)) {
4486 /* Because we don't support block-based V3 on tx-ring */
4487 if (!tx_ring)
4488 prb_shutdown_retire_blk_timer(po, rb_queue);
4489 }
4490
4491 out_free_pg_vec:
4492 if (pg_vec) {
4493 bitmap_free(rx_owner_map);
4494 free_pg_vec(pg_vec, order, req->tp_block_nr);
4495 }
4496 out:
4497 return err;
4498 }
4499
packet_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)4500 static int packet_mmap(struct file *file, struct socket *sock,
4501 struct vm_area_struct *vma)
4502 {
4503 struct sock *sk = sock->sk;
4504 struct packet_sock *po = pkt_sk(sk);
4505 unsigned long size, expected_size;
4506 struct packet_ring_buffer *rb;
4507 unsigned long start;
4508 int err = -EINVAL;
4509 int i;
4510
4511 if (vma->vm_pgoff)
4512 return -EINVAL;
4513
4514 mutex_lock(&po->pg_vec_lock);
4515
4516 expected_size = 0;
4517 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4518 if (rb->pg_vec) {
4519 expected_size += rb->pg_vec_len
4520 * rb->pg_vec_pages
4521 * PAGE_SIZE;
4522 }
4523 }
4524
4525 if (expected_size == 0)
4526 goto out;
4527
4528 size = vma->vm_end - vma->vm_start;
4529 if (size != expected_size)
4530 goto out;
4531
4532 start = vma->vm_start;
4533 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4534 if (rb->pg_vec == NULL)
4535 continue;
4536
4537 for (i = 0; i < rb->pg_vec_len; i++) {
4538 struct page *page;
4539 void *kaddr = rb->pg_vec[i].buffer;
4540 int pg_num;
4541
4542 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4543 page = pgv_to_page(kaddr);
4544 err = vm_insert_page(vma, start, page);
4545 if (unlikely(err))
4546 goto out;
4547 start += PAGE_SIZE;
4548 kaddr += PAGE_SIZE;
4549 }
4550 }
4551 }
4552
4553 atomic_inc(&po->mapped);
4554 vma->vm_ops = &packet_mmap_ops;
4555 err = 0;
4556
4557 out:
4558 mutex_unlock(&po->pg_vec_lock);
4559 return err;
4560 }
4561
4562 static const struct proto_ops packet_ops_spkt = {
4563 .family = PF_PACKET,
4564 .owner = THIS_MODULE,
4565 .release = packet_release,
4566 .bind = packet_bind_spkt,
4567 .connect = sock_no_connect,
4568 .socketpair = sock_no_socketpair,
4569 .accept = sock_no_accept,
4570 .getname = packet_getname_spkt,
4571 .poll = datagram_poll,
4572 .ioctl = packet_ioctl,
4573 .gettstamp = sock_gettstamp,
4574 .listen = sock_no_listen,
4575 .shutdown = sock_no_shutdown,
4576 .sendmsg = packet_sendmsg_spkt,
4577 .recvmsg = packet_recvmsg,
4578 .mmap = sock_no_mmap,
4579 .sendpage = sock_no_sendpage,
4580 };
4581
4582 static const struct proto_ops packet_ops = {
4583 .family = PF_PACKET,
4584 .owner = THIS_MODULE,
4585 .release = packet_release,
4586 .bind = packet_bind,
4587 .connect = sock_no_connect,
4588 .socketpair = sock_no_socketpair,
4589 .accept = sock_no_accept,
4590 .getname = packet_getname,
4591 .poll = packet_poll,
4592 .ioctl = packet_ioctl,
4593 .gettstamp = sock_gettstamp,
4594 .listen = sock_no_listen,
4595 .shutdown = sock_no_shutdown,
4596 .setsockopt = packet_setsockopt,
4597 .getsockopt = packet_getsockopt,
4598 .sendmsg = packet_sendmsg,
4599 .recvmsg = packet_recvmsg,
4600 .mmap = packet_mmap,
4601 .sendpage = sock_no_sendpage,
4602 };
4603
4604 static const struct net_proto_family packet_family_ops = {
4605 .family = PF_PACKET,
4606 .create = packet_create,
4607 .owner = THIS_MODULE,
4608 };
4609
4610 static struct notifier_block packet_netdev_notifier = {
4611 .notifier_call = packet_notifier,
4612 };
4613
4614 #ifdef CONFIG_PROC_FS
4615
packet_seq_start(struct seq_file * seq,loff_t * pos)4616 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4617 __acquires(RCU)
4618 {
4619 struct net *net = seq_file_net(seq);
4620
4621 rcu_read_lock();
4622 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4623 }
4624
packet_seq_next(struct seq_file * seq,void * v,loff_t * pos)4625 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4626 {
4627 struct net *net = seq_file_net(seq);
4628 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4629 }
4630
packet_seq_stop(struct seq_file * seq,void * v)4631 static void packet_seq_stop(struct seq_file *seq, void *v)
4632 __releases(RCU)
4633 {
4634 rcu_read_unlock();
4635 }
4636
packet_seq_show(struct seq_file * seq,void * v)4637 static int packet_seq_show(struct seq_file *seq, void *v)
4638 {
4639 if (v == SEQ_START_TOKEN)
4640 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
4641 else {
4642 struct sock *s = sk_entry(v);
4643 const struct packet_sock *po = pkt_sk(s);
4644
4645 seq_printf(seq,
4646 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
4647 s,
4648 refcount_read(&s->sk_refcnt),
4649 s->sk_type,
4650 ntohs(READ_ONCE(po->num)),
4651 READ_ONCE(po->ifindex),
4652 po->running,
4653 atomic_read(&s->sk_rmem_alloc),
4654 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4655 sock_i_ino(s));
4656 }
4657
4658 return 0;
4659 }
4660
4661 static const struct seq_operations packet_seq_ops = {
4662 .start = packet_seq_start,
4663 .next = packet_seq_next,
4664 .stop = packet_seq_stop,
4665 .show = packet_seq_show,
4666 };
4667 #endif
4668
packet_net_init(struct net * net)4669 static int __net_init packet_net_init(struct net *net)
4670 {
4671 mutex_init(&net->packet.sklist_lock);
4672 INIT_HLIST_HEAD(&net->packet.sklist);
4673
4674 #ifdef CONFIG_PROC_FS
4675 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4676 sizeof(struct seq_net_private)))
4677 return -ENOMEM;
4678 #endif /* CONFIG_PROC_FS */
4679
4680 return 0;
4681 }
4682
packet_net_exit(struct net * net)4683 static void __net_exit packet_net_exit(struct net *net)
4684 {
4685 remove_proc_entry("packet", net->proc_net);
4686 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4687 }
4688
4689 static struct pernet_operations packet_net_ops = {
4690 .init = packet_net_init,
4691 .exit = packet_net_exit,
4692 };
4693
4694
packet_exit(void)4695 static void __exit packet_exit(void)
4696 {
4697 unregister_netdevice_notifier(&packet_netdev_notifier);
4698 unregister_pernet_subsys(&packet_net_ops);
4699 sock_unregister(PF_PACKET);
4700 proto_unregister(&packet_proto);
4701 }
4702
packet_init(void)4703 static int __init packet_init(void)
4704 {
4705 int rc;
4706
4707 rc = proto_register(&packet_proto, 0);
4708 if (rc)
4709 goto out;
4710 rc = sock_register(&packet_family_ops);
4711 if (rc)
4712 goto out_proto;
4713 rc = register_pernet_subsys(&packet_net_ops);
4714 if (rc)
4715 goto out_sock;
4716 rc = register_netdevice_notifier(&packet_netdev_notifier);
4717 if (rc)
4718 goto out_pernet;
4719
4720 return 0;
4721
4722 out_pernet:
4723 unregister_pernet_subsys(&packet_net_ops);
4724 out_sock:
4725 sock_unregister(PF_PACKET);
4726 out_proto:
4727 proto_unregister(&packet_proto);
4728 out:
4729 return rc;
4730 }
4731
4732 module_init(packet_init);
4733 module_exit(packet_exit);
4734 MODULE_LICENSE("GPL");
4735 MODULE_ALIAS_NETPROTO(PF_PACKET);
4736