1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <asm/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/percpu.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 96 #include "internal.h" 97 98 /* 99 Assumptions: 100 - if device has no dev->hard_header routine, it adds and removes ll header 101 inside itself. In this case ll header is invisible outside of device, 102 but higher levels still should reserve dev->hard_header_len. 103 Some devices are enough clever to reallocate skb, when header 104 will not fit to reserved space (tunnel), another ones are silly 105 (PPP). 106 - packet socket receives packets with pulled ll header, 107 so that SOCK_RAW should push it back. 108 109 On receive: 110 ----------- 111 112 Incoming, dev->hard_header!=NULL 113 mac_header -> ll header 114 data -> data 115 116 Outgoing, dev->hard_header!=NULL 117 mac_header -> ll header 118 data -> ll header 119 120 Incoming, dev->hard_header==NULL 121 mac_header -> UNKNOWN position. It is very likely, that it points to ll 122 header. PPP makes it, that is wrong, because introduce 123 assymetry between rx and tx paths. 124 data -> data 125 126 Outgoing, dev->hard_header==NULL 127 mac_header -> data. ll header is still not built! 128 data -> data 129 130 Resume 131 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 132 133 134 On transmit: 135 ------------ 136 137 dev->hard_header != NULL 138 mac_header -> ll header 139 data -> ll header 140 141 dev->hard_header == NULL (ll header is added by device, we cannot control it) 142 mac_header -> data 143 data -> data 144 145 We should set nh.raw on output to correct posistion, 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 PGV_FROM_VMALLOC 1 179 180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 187 188 struct packet_sock; 189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 191 struct packet_type *pt, struct net_device *orig_dev); 192 193 static void *packet_previous_frame(struct packet_sock *po, 194 struct packet_ring_buffer *rb, 195 int status); 196 static void packet_increment_head(struct packet_ring_buffer *buff); 197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 198 struct tpacket_block_desc *); 199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 200 struct packet_sock *); 201 static void prb_retire_current_block(struct tpacket_kbdq_core *, 202 struct packet_sock *, unsigned int status); 203 static int prb_queue_frozen(struct tpacket_kbdq_core *); 204 static void prb_open_block(struct tpacket_kbdq_core *, 205 struct tpacket_block_desc *); 206 static void prb_retire_rx_blk_timer_expired(unsigned long); 207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 208 static void prb_init_blk_timer(struct packet_sock *, 209 struct tpacket_kbdq_core *, 210 void (*func) (unsigned long)); 211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 212 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 213 struct tpacket3_hdr *); 214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 215 struct tpacket3_hdr *); 216 static void packet_flush_mclist(struct sock *sk); 217 218 struct packet_skb_cb { 219 unsigned int origlen; 220 union { 221 struct sockaddr_pkt pkt; 222 struct sockaddr_ll ll; 223 } sa; 224 }; 225 226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 227 228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 229 #define GET_PBLOCK_DESC(x, bid) \ 230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 233 #define GET_NEXT_PRB_BLK_NUM(x) \ 234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 235 ((x)->kactive_blk_num+1) : 0) 236 237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 238 static void __fanout_link(struct sock *sk, struct packet_sock *po); 239 240 static int packet_direct_xmit(struct sk_buff *skb) 241 { 242 struct net_device *dev = skb->dev; 243 netdev_features_t features; 244 struct netdev_queue *txq; 245 int ret = NETDEV_TX_BUSY; 246 247 if (unlikely(!netif_running(dev) || 248 !netif_carrier_ok(dev))) 249 goto drop; 250 251 features = netif_skb_features(skb); 252 if (skb_needs_linearize(skb, features) && 253 __skb_linearize(skb)) 254 goto drop; 255 256 txq = skb_get_tx_queue(dev, skb); 257 258 local_bh_disable(); 259 260 HARD_TX_LOCK(dev, txq, smp_processor_id()); 261 if (!netif_xmit_frozen_or_drv_stopped(txq)) 262 ret = netdev_start_xmit(skb, dev, txq, false); 263 HARD_TX_UNLOCK(dev, txq); 264 265 local_bh_enable(); 266 267 if (!dev_xmit_complete(ret)) 268 kfree_skb(skb); 269 270 return ret; 271 drop: 272 atomic_long_inc(&dev->tx_dropped); 273 kfree_skb(skb); 274 return NET_XMIT_DROP; 275 } 276 277 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 278 { 279 struct net_device *dev; 280 281 rcu_read_lock(); 282 dev = rcu_dereference(po->cached_dev); 283 if (likely(dev)) 284 dev_hold(dev); 285 rcu_read_unlock(); 286 287 return dev; 288 } 289 290 static void packet_cached_dev_assign(struct packet_sock *po, 291 struct net_device *dev) 292 { 293 rcu_assign_pointer(po->cached_dev, dev); 294 } 295 296 static void packet_cached_dev_reset(struct packet_sock *po) 297 { 298 RCU_INIT_POINTER(po->cached_dev, NULL); 299 } 300 301 static bool packet_use_direct_xmit(const struct packet_sock *po) 302 { 303 return po->xmit == packet_direct_xmit; 304 } 305 306 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 307 { 308 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues; 309 } 310 311 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 312 { 313 const struct net_device_ops *ops = dev->netdev_ops; 314 u16 queue_index; 315 316 if (ops->ndo_select_queue) { 317 queue_index = ops->ndo_select_queue(dev, skb, NULL, 318 __packet_pick_tx_queue); 319 queue_index = netdev_cap_txqueue(dev, queue_index); 320 } else { 321 queue_index = __packet_pick_tx_queue(dev, skb); 322 } 323 324 skb_set_queue_mapping(skb, queue_index); 325 } 326 327 /* register_prot_hook must be invoked with the po->bind_lock held, 328 * or from a context in which asynchronous accesses to the packet 329 * socket is not possible (packet_create()). 330 */ 331 static void register_prot_hook(struct sock *sk) 332 { 333 struct packet_sock *po = pkt_sk(sk); 334 335 if (!po->running) { 336 if (po->fanout) 337 __fanout_link(sk, po); 338 else 339 dev_add_pack(&po->prot_hook); 340 341 sock_hold(sk); 342 po->running = 1; 343 } 344 } 345 346 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 347 * held. If the sync parameter is true, we will temporarily drop 348 * the po->bind_lock and do a synchronize_net to make sure no 349 * asynchronous packet processing paths still refer to the elements 350 * of po->prot_hook. If the sync parameter is false, it is the 351 * callers responsibility to take care of this. 352 */ 353 static void __unregister_prot_hook(struct sock *sk, bool sync) 354 { 355 struct packet_sock *po = pkt_sk(sk); 356 357 po->running = 0; 358 359 if (po->fanout) 360 __fanout_unlink(sk, po); 361 else 362 __dev_remove_pack(&po->prot_hook); 363 364 __sock_put(sk); 365 366 if (sync) { 367 spin_unlock(&po->bind_lock); 368 synchronize_net(); 369 spin_lock(&po->bind_lock); 370 } 371 } 372 373 static void unregister_prot_hook(struct sock *sk, bool sync) 374 { 375 struct packet_sock *po = pkt_sk(sk); 376 377 if (po->running) 378 __unregister_prot_hook(sk, sync); 379 } 380 381 static inline __pure struct page *pgv_to_page(void *addr) 382 { 383 if (is_vmalloc_addr(addr)) 384 return vmalloc_to_page(addr); 385 return virt_to_page(addr); 386 } 387 388 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 389 { 390 union tpacket_uhdr h; 391 392 h.raw = frame; 393 switch (po->tp_version) { 394 case TPACKET_V1: 395 h.h1->tp_status = status; 396 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 397 break; 398 case TPACKET_V2: 399 h.h2->tp_status = status; 400 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 401 break; 402 case TPACKET_V3: 403 default: 404 WARN(1, "TPACKET version not supported.\n"); 405 BUG(); 406 } 407 408 smp_wmb(); 409 } 410 411 static int __packet_get_status(struct packet_sock *po, void *frame) 412 { 413 union tpacket_uhdr h; 414 415 smp_rmb(); 416 417 h.raw = frame; 418 switch (po->tp_version) { 419 case TPACKET_V1: 420 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 421 return h.h1->tp_status; 422 case TPACKET_V2: 423 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 424 return h.h2->tp_status; 425 case TPACKET_V3: 426 default: 427 WARN(1, "TPACKET version not supported.\n"); 428 BUG(); 429 return 0; 430 } 431 } 432 433 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 434 unsigned int flags) 435 { 436 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 437 438 if (shhwtstamps && 439 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 440 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 441 return TP_STATUS_TS_RAW_HARDWARE; 442 443 if (ktime_to_timespec_cond(skb->tstamp, ts)) 444 return TP_STATUS_TS_SOFTWARE; 445 446 return 0; 447 } 448 449 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 450 struct sk_buff *skb) 451 { 452 union tpacket_uhdr h; 453 struct timespec ts; 454 __u32 ts_status; 455 456 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 457 return 0; 458 459 h.raw = frame; 460 switch (po->tp_version) { 461 case TPACKET_V1: 462 h.h1->tp_sec = ts.tv_sec; 463 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 464 break; 465 case TPACKET_V2: 466 h.h2->tp_sec = ts.tv_sec; 467 h.h2->tp_nsec = ts.tv_nsec; 468 break; 469 case TPACKET_V3: 470 default: 471 WARN(1, "TPACKET version not supported.\n"); 472 BUG(); 473 } 474 475 /* one flush is safe, as both fields always lie on the same cacheline */ 476 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 477 smp_wmb(); 478 479 return ts_status; 480 } 481 482 static void *packet_lookup_frame(struct packet_sock *po, 483 struct packet_ring_buffer *rb, 484 unsigned int position, 485 int status) 486 { 487 unsigned int pg_vec_pos, frame_offset; 488 union tpacket_uhdr h; 489 490 pg_vec_pos = position / rb->frames_per_block; 491 frame_offset = position % rb->frames_per_block; 492 493 h.raw = rb->pg_vec[pg_vec_pos].buffer + 494 (frame_offset * rb->frame_size); 495 496 if (status != __packet_get_status(po, h.raw)) 497 return NULL; 498 499 return h.raw; 500 } 501 502 static void *packet_current_frame(struct packet_sock *po, 503 struct packet_ring_buffer *rb, 504 int status) 505 { 506 return packet_lookup_frame(po, rb, rb->head, status); 507 } 508 509 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 510 { 511 del_timer_sync(&pkc->retire_blk_timer); 512 } 513 514 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 515 int tx_ring, 516 struct sk_buff_head *rb_queue) 517 { 518 struct tpacket_kbdq_core *pkc; 519 520 pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) : 521 GET_PBDQC_FROM_RB(&po->rx_ring); 522 523 spin_lock_bh(&rb_queue->lock); 524 pkc->delete_blk_timer = 1; 525 spin_unlock_bh(&rb_queue->lock); 526 527 prb_del_retire_blk_timer(pkc); 528 } 529 530 static void prb_init_blk_timer(struct packet_sock *po, 531 struct tpacket_kbdq_core *pkc, 532 void (*func) (unsigned long)) 533 { 534 init_timer(&pkc->retire_blk_timer); 535 pkc->retire_blk_timer.data = (long)po; 536 pkc->retire_blk_timer.function = func; 537 pkc->retire_blk_timer.expires = jiffies; 538 } 539 540 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 541 { 542 struct tpacket_kbdq_core *pkc; 543 544 if (tx_ring) 545 BUG(); 546 547 pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) : 548 GET_PBDQC_FROM_RB(&po->rx_ring); 549 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 550 } 551 552 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 553 int blk_size_in_bytes) 554 { 555 struct net_device *dev; 556 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 557 struct ethtool_cmd ecmd; 558 int err; 559 u32 speed; 560 561 rtnl_lock(); 562 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 563 if (unlikely(!dev)) { 564 rtnl_unlock(); 565 return DEFAULT_PRB_RETIRE_TOV; 566 } 567 err = __ethtool_get_settings(dev, &ecmd); 568 speed = ethtool_cmd_speed(&ecmd); 569 rtnl_unlock(); 570 if (!err) { 571 /* 572 * If the link speed is so slow you don't really 573 * need to worry about perf anyways 574 */ 575 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 576 return DEFAULT_PRB_RETIRE_TOV; 577 } else { 578 msec = 1; 579 div = speed / 1000; 580 } 581 } 582 583 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 584 585 if (div) 586 mbits /= div; 587 588 tmo = mbits * msec; 589 590 if (div) 591 return tmo+1; 592 return tmo; 593 } 594 595 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 596 union tpacket_req_u *req_u) 597 { 598 p1->feature_req_word = req_u->req3.tp_feature_req_word; 599 } 600 601 static void init_prb_bdqc(struct packet_sock *po, 602 struct packet_ring_buffer *rb, 603 struct pgv *pg_vec, 604 union tpacket_req_u *req_u, int tx_ring) 605 { 606 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 607 struct tpacket_block_desc *pbd; 608 609 memset(p1, 0x0, sizeof(*p1)); 610 611 p1->knxt_seq_num = 1; 612 p1->pkbdq = pg_vec; 613 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 614 p1->pkblk_start = pg_vec[0].buffer; 615 p1->kblk_size = req_u->req3.tp_block_size; 616 p1->knum_blocks = req_u->req3.tp_block_nr; 617 p1->hdrlen = po->tp_hdrlen; 618 p1->version = po->tp_version; 619 p1->last_kactive_blk_num = 0; 620 po->stats.stats3.tp_freeze_q_cnt = 0; 621 if (req_u->req3.tp_retire_blk_tov) 622 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 623 else 624 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 625 req_u->req3.tp_block_size); 626 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 627 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 628 629 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 630 prb_init_ft_ops(p1, req_u); 631 prb_setup_retire_blk_timer(po, tx_ring); 632 prb_open_block(p1, pbd); 633 } 634 635 /* Do NOT update the last_blk_num first. 636 * Assumes sk_buff_head lock is held. 637 */ 638 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 639 { 640 mod_timer(&pkc->retire_blk_timer, 641 jiffies + pkc->tov_in_jiffies); 642 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 643 } 644 645 /* 646 * Timer logic: 647 * 1) We refresh the timer only when we open a block. 648 * By doing this we don't waste cycles refreshing the timer 649 * on packet-by-packet basis. 650 * 651 * With a 1MB block-size, on a 1Gbps line, it will take 652 * i) ~8 ms to fill a block + ii) memcpy etc. 653 * In this cut we are not accounting for the memcpy time. 654 * 655 * So, if the user sets the 'tmo' to 10ms then the timer 656 * will never fire while the block is still getting filled 657 * (which is what we want). However, the user could choose 658 * to close a block early and that's fine. 659 * 660 * But when the timer does fire, we check whether or not to refresh it. 661 * Since the tmo granularity is in msecs, it is not too expensive 662 * to refresh the timer, lets say every '8' msecs. 663 * Either the user can set the 'tmo' or we can derive it based on 664 * a) line-speed and b) block-size. 665 * prb_calc_retire_blk_tmo() calculates the tmo. 666 * 667 */ 668 static void prb_retire_rx_blk_timer_expired(unsigned long data) 669 { 670 struct packet_sock *po = (struct packet_sock *)data; 671 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 672 unsigned int frozen; 673 struct tpacket_block_desc *pbd; 674 675 spin_lock(&po->sk.sk_receive_queue.lock); 676 677 frozen = prb_queue_frozen(pkc); 678 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 679 680 if (unlikely(pkc->delete_blk_timer)) 681 goto out; 682 683 /* We only need to plug the race when the block is partially filled. 684 * tpacket_rcv: 685 * lock(); increment BLOCK_NUM_PKTS; unlock() 686 * copy_bits() is in progress ... 687 * timer fires on other cpu: 688 * we can't retire the current block because copy_bits 689 * is in progress. 690 * 691 */ 692 if (BLOCK_NUM_PKTS(pbd)) { 693 while (atomic_read(&pkc->blk_fill_in_prog)) { 694 /* Waiting for skb_copy_bits to finish... */ 695 cpu_relax(); 696 } 697 } 698 699 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 700 if (!frozen) { 701 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 702 if (!prb_dispatch_next_block(pkc, po)) 703 goto refresh_timer; 704 else 705 goto out; 706 } else { 707 /* Case 1. Queue was frozen because user-space was 708 * lagging behind. 709 */ 710 if (prb_curr_blk_in_use(pkc, pbd)) { 711 /* 712 * Ok, user-space is still behind. 713 * So just refresh the timer. 714 */ 715 goto refresh_timer; 716 } else { 717 /* Case 2. queue was frozen,user-space caught up, 718 * now the link went idle && the timer fired. 719 * We don't have a block to close.So we open this 720 * block and restart the timer. 721 * opening a block thaws the queue,restarts timer 722 * Thawing/timer-refresh is a side effect. 723 */ 724 prb_open_block(pkc, pbd); 725 goto out; 726 } 727 } 728 } 729 730 refresh_timer: 731 _prb_refresh_rx_retire_blk_timer(pkc); 732 733 out: 734 spin_unlock(&po->sk.sk_receive_queue.lock); 735 } 736 737 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 738 struct tpacket_block_desc *pbd1, __u32 status) 739 { 740 /* Flush everything minus the block header */ 741 742 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 743 u8 *start, *end; 744 745 start = (u8 *)pbd1; 746 747 /* Skip the block header(we know header WILL fit in 4K) */ 748 start += PAGE_SIZE; 749 750 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 751 for (; start < end; start += PAGE_SIZE) 752 flush_dcache_page(pgv_to_page(start)); 753 754 smp_wmb(); 755 #endif 756 757 /* Now update the block status. */ 758 759 BLOCK_STATUS(pbd1) = status; 760 761 /* Flush the block header */ 762 763 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 764 start = (u8 *)pbd1; 765 flush_dcache_page(pgv_to_page(start)); 766 767 smp_wmb(); 768 #endif 769 } 770 771 /* 772 * Side effect: 773 * 774 * 1) flush the block 775 * 2) Increment active_blk_num 776 * 777 * Note:We DONT refresh the timer on purpose. 778 * Because almost always the next block will be opened. 779 */ 780 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 781 struct tpacket_block_desc *pbd1, 782 struct packet_sock *po, unsigned int stat) 783 { 784 __u32 status = TP_STATUS_USER | stat; 785 786 struct tpacket3_hdr *last_pkt; 787 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 788 789 if (po->stats.stats3.tp_drops) 790 status |= TP_STATUS_LOSING; 791 792 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 793 last_pkt->tp_next_offset = 0; 794 795 /* Get the ts of the last pkt */ 796 if (BLOCK_NUM_PKTS(pbd1)) { 797 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 798 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 799 } else { 800 /* Ok, we tmo'd - so get the current time */ 801 struct timespec ts; 802 getnstimeofday(&ts); 803 h1->ts_last_pkt.ts_sec = ts.tv_sec; 804 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 805 } 806 807 smp_wmb(); 808 809 /* Flush the block */ 810 prb_flush_block(pkc1, pbd1, status); 811 812 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 813 } 814 815 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 816 { 817 pkc->reset_pending_on_curr_blk = 0; 818 } 819 820 /* 821 * Side effect of opening a block: 822 * 823 * 1) prb_queue is thawed. 824 * 2) retire_blk_timer is refreshed. 825 * 826 */ 827 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 828 struct tpacket_block_desc *pbd1) 829 { 830 struct timespec ts; 831 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 832 833 smp_rmb(); 834 835 /* We could have just memset this but we will lose the 836 * flexibility of making the priv area sticky 837 */ 838 839 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 840 BLOCK_NUM_PKTS(pbd1) = 0; 841 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 842 843 getnstimeofday(&ts); 844 845 h1->ts_first_pkt.ts_sec = ts.tv_sec; 846 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 847 848 pkc1->pkblk_start = (char *)pbd1; 849 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 850 851 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 852 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 853 854 pbd1->version = pkc1->version; 855 pkc1->prev = pkc1->nxt_offset; 856 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 857 858 prb_thaw_queue(pkc1); 859 _prb_refresh_rx_retire_blk_timer(pkc1); 860 861 smp_wmb(); 862 } 863 864 /* 865 * Queue freeze logic: 866 * 1) Assume tp_block_nr = 8 blocks. 867 * 2) At time 't0', user opens Rx ring. 868 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 869 * 4) user-space is either sleeping or processing block '0'. 870 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 871 * it will close block-7,loop around and try to fill block '0'. 872 * call-flow: 873 * __packet_lookup_frame_in_block 874 * prb_retire_current_block() 875 * prb_dispatch_next_block() 876 * |->(BLOCK_STATUS == USER) evaluates to true 877 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 878 * 6) Now there are two cases: 879 * 6.1) Link goes idle right after the queue is frozen. 880 * But remember, the last open_block() refreshed the timer. 881 * When this timer expires,it will refresh itself so that we can 882 * re-open block-0 in near future. 883 * 6.2) Link is busy and keeps on receiving packets. This is a simple 884 * case and __packet_lookup_frame_in_block will check if block-0 885 * is free and can now be re-used. 886 */ 887 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 888 struct packet_sock *po) 889 { 890 pkc->reset_pending_on_curr_blk = 1; 891 po->stats.stats3.tp_freeze_q_cnt++; 892 } 893 894 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 895 896 /* 897 * If the next block is free then we will dispatch it 898 * and return a good offset. 899 * Else, we will freeze the queue. 900 * So, caller must check the return value. 901 */ 902 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 903 struct packet_sock *po) 904 { 905 struct tpacket_block_desc *pbd; 906 907 smp_rmb(); 908 909 /* 1. Get current block num */ 910 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 911 912 /* 2. If this block is currently in_use then freeze the queue */ 913 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 914 prb_freeze_queue(pkc, po); 915 return NULL; 916 } 917 918 /* 919 * 3. 920 * open this block and return the offset where the first packet 921 * needs to get stored. 922 */ 923 prb_open_block(pkc, pbd); 924 return (void *)pkc->nxt_offset; 925 } 926 927 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 928 struct packet_sock *po, unsigned int status) 929 { 930 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 931 932 /* retire/close the current block */ 933 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 934 /* 935 * Plug the case where copy_bits() is in progress on 936 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 937 * have space to copy the pkt in the current block and 938 * called prb_retire_current_block() 939 * 940 * We don't need to worry about the TMO case because 941 * the timer-handler already handled this case. 942 */ 943 if (!(status & TP_STATUS_BLK_TMO)) { 944 while (atomic_read(&pkc->blk_fill_in_prog)) { 945 /* Waiting for skb_copy_bits to finish... */ 946 cpu_relax(); 947 } 948 } 949 prb_close_block(pkc, pbd, po, status); 950 return; 951 } 952 } 953 954 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 955 struct tpacket_block_desc *pbd) 956 { 957 return TP_STATUS_USER & BLOCK_STATUS(pbd); 958 } 959 960 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 961 { 962 return pkc->reset_pending_on_curr_blk; 963 } 964 965 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 966 { 967 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 968 atomic_dec(&pkc->blk_fill_in_prog); 969 } 970 971 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 972 struct tpacket3_hdr *ppd) 973 { 974 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 975 } 976 977 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 978 struct tpacket3_hdr *ppd) 979 { 980 ppd->hv1.tp_rxhash = 0; 981 } 982 983 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 984 struct tpacket3_hdr *ppd) 985 { 986 if (vlan_tx_tag_present(pkc->skb)) { 987 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 988 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 989 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 990 } else { 991 ppd->hv1.tp_vlan_tci = 0; 992 ppd->hv1.tp_vlan_tpid = 0; 993 ppd->tp_status = TP_STATUS_AVAILABLE; 994 } 995 } 996 997 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 998 struct tpacket3_hdr *ppd) 999 { 1000 ppd->hv1.tp_padding = 0; 1001 prb_fill_vlan_info(pkc, ppd); 1002 1003 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1004 prb_fill_rxhash(pkc, ppd); 1005 else 1006 prb_clear_rxhash(pkc, ppd); 1007 } 1008 1009 static void prb_fill_curr_block(char *curr, 1010 struct tpacket_kbdq_core *pkc, 1011 struct tpacket_block_desc *pbd, 1012 unsigned int len) 1013 { 1014 struct tpacket3_hdr *ppd; 1015 1016 ppd = (struct tpacket3_hdr *)curr; 1017 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1018 pkc->prev = curr; 1019 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1020 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1021 BLOCK_NUM_PKTS(pbd) += 1; 1022 atomic_inc(&pkc->blk_fill_in_prog); 1023 prb_run_all_ft_ops(pkc, ppd); 1024 } 1025 1026 /* Assumes caller has the sk->rx_queue.lock */ 1027 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1028 struct sk_buff *skb, 1029 int status, 1030 unsigned int len 1031 ) 1032 { 1033 struct tpacket_kbdq_core *pkc; 1034 struct tpacket_block_desc *pbd; 1035 char *curr, *end; 1036 1037 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1038 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1039 1040 /* Queue is frozen when user space is lagging behind */ 1041 if (prb_queue_frozen(pkc)) { 1042 /* 1043 * Check if that last block which caused the queue to freeze, 1044 * is still in_use by user-space. 1045 */ 1046 if (prb_curr_blk_in_use(pkc, pbd)) { 1047 /* Can't record this packet */ 1048 return NULL; 1049 } else { 1050 /* 1051 * Ok, the block was released by user-space. 1052 * Now let's open that block. 1053 * opening a block also thaws the queue. 1054 * Thawing is a side effect. 1055 */ 1056 prb_open_block(pkc, pbd); 1057 } 1058 } 1059 1060 smp_mb(); 1061 curr = pkc->nxt_offset; 1062 pkc->skb = skb; 1063 end = (char *)pbd + pkc->kblk_size; 1064 1065 /* first try the current block */ 1066 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1067 prb_fill_curr_block(curr, pkc, pbd, len); 1068 return (void *)curr; 1069 } 1070 1071 /* Ok, close the current block */ 1072 prb_retire_current_block(pkc, po, 0); 1073 1074 /* Now, try to dispatch the next block */ 1075 curr = (char *)prb_dispatch_next_block(pkc, po); 1076 if (curr) { 1077 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1078 prb_fill_curr_block(curr, pkc, pbd, len); 1079 return (void *)curr; 1080 } 1081 1082 /* 1083 * No free blocks are available.user_space hasn't caught up yet. 1084 * Queue was just frozen and now this packet will get dropped. 1085 */ 1086 return NULL; 1087 } 1088 1089 static void *packet_current_rx_frame(struct packet_sock *po, 1090 struct sk_buff *skb, 1091 int status, unsigned int len) 1092 { 1093 char *curr = NULL; 1094 switch (po->tp_version) { 1095 case TPACKET_V1: 1096 case TPACKET_V2: 1097 curr = packet_lookup_frame(po, &po->rx_ring, 1098 po->rx_ring.head, status); 1099 return curr; 1100 case TPACKET_V3: 1101 return __packet_lookup_frame_in_block(po, skb, status, len); 1102 default: 1103 WARN(1, "TPACKET version not supported\n"); 1104 BUG(); 1105 return NULL; 1106 } 1107 } 1108 1109 static void *prb_lookup_block(struct packet_sock *po, 1110 struct packet_ring_buffer *rb, 1111 unsigned int idx, 1112 int status) 1113 { 1114 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1115 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1116 1117 if (status != BLOCK_STATUS(pbd)) 1118 return NULL; 1119 return pbd; 1120 } 1121 1122 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1123 { 1124 unsigned int prev; 1125 if (rb->prb_bdqc.kactive_blk_num) 1126 prev = rb->prb_bdqc.kactive_blk_num-1; 1127 else 1128 prev = rb->prb_bdqc.knum_blocks-1; 1129 return prev; 1130 } 1131 1132 /* Assumes caller has held the rx_queue.lock */ 1133 static void *__prb_previous_block(struct packet_sock *po, 1134 struct packet_ring_buffer *rb, 1135 int status) 1136 { 1137 unsigned int previous = prb_previous_blk_num(rb); 1138 return prb_lookup_block(po, rb, previous, status); 1139 } 1140 1141 static void *packet_previous_rx_frame(struct packet_sock *po, 1142 struct packet_ring_buffer *rb, 1143 int status) 1144 { 1145 if (po->tp_version <= TPACKET_V2) 1146 return packet_previous_frame(po, rb, status); 1147 1148 return __prb_previous_block(po, rb, status); 1149 } 1150 1151 static void packet_increment_rx_head(struct packet_sock *po, 1152 struct packet_ring_buffer *rb) 1153 { 1154 switch (po->tp_version) { 1155 case TPACKET_V1: 1156 case TPACKET_V2: 1157 return packet_increment_head(rb); 1158 case TPACKET_V3: 1159 default: 1160 WARN(1, "TPACKET version not supported.\n"); 1161 BUG(); 1162 return; 1163 } 1164 } 1165 1166 static void *packet_previous_frame(struct packet_sock *po, 1167 struct packet_ring_buffer *rb, 1168 int status) 1169 { 1170 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1171 return packet_lookup_frame(po, rb, previous, status); 1172 } 1173 1174 static void packet_increment_head(struct packet_ring_buffer *buff) 1175 { 1176 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1177 } 1178 1179 static void packet_inc_pending(struct packet_ring_buffer *rb) 1180 { 1181 this_cpu_inc(*rb->pending_refcnt); 1182 } 1183 1184 static void packet_dec_pending(struct packet_ring_buffer *rb) 1185 { 1186 this_cpu_dec(*rb->pending_refcnt); 1187 } 1188 1189 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1190 { 1191 unsigned int refcnt = 0; 1192 int cpu; 1193 1194 /* We don't use pending refcount in rx_ring. */ 1195 if (rb->pending_refcnt == NULL) 1196 return 0; 1197 1198 for_each_possible_cpu(cpu) 1199 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1200 1201 return refcnt; 1202 } 1203 1204 static int packet_alloc_pending(struct packet_sock *po) 1205 { 1206 po->rx_ring.pending_refcnt = NULL; 1207 1208 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1209 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1210 return -ENOBUFS; 1211 1212 return 0; 1213 } 1214 1215 static void packet_free_pending(struct packet_sock *po) 1216 { 1217 free_percpu(po->tx_ring.pending_refcnt); 1218 } 1219 1220 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1221 { 1222 struct sock *sk = &po->sk; 1223 bool has_room; 1224 1225 if (po->prot_hook.func != tpacket_rcv) 1226 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize) 1227 <= sk->sk_rcvbuf; 1228 1229 spin_lock(&sk->sk_receive_queue.lock); 1230 if (po->tp_version == TPACKET_V3) 1231 has_room = prb_lookup_block(po, &po->rx_ring, 1232 po->rx_ring.prb_bdqc.kactive_blk_num, 1233 TP_STATUS_KERNEL); 1234 else 1235 has_room = packet_lookup_frame(po, &po->rx_ring, 1236 po->rx_ring.head, 1237 TP_STATUS_KERNEL); 1238 spin_unlock(&sk->sk_receive_queue.lock); 1239 1240 return has_room; 1241 } 1242 1243 static void packet_sock_destruct(struct sock *sk) 1244 { 1245 skb_queue_purge(&sk->sk_error_queue); 1246 1247 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1248 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1249 1250 if (!sock_flag(sk, SOCK_DEAD)) { 1251 pr_err("Attempt to release alive packet socket: %p\n", sk); 1252 return; 1253 } 1254 1255 sk_refcnt_debug_dec(sk); 1256 } 1257 1258 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1259 { 1260 int x = atomic_read(&f->rr_cur) + 1; 1261 1262 if (x >= num) 1263 x = 0; 1264 1265 return x; 1266 } 1267 1268 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1269 struct sk_buff *skb, 1270 unsigned int num) 1271 { 1272 return reciprocal_scale(skb_get_hash(skb), num); 1273 } 1274 1275 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1276 struct sk_buff *skb, 1277 unsigned int num) 1278 { 1279 int cur, old; 1280 1281 cur = atomic_read(&f->rr_cur); 1282 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1283 fanout_rr_next(f, num))) != cur) 1284 cur = old; 1285 return cur; 1286 } 1287 1288 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1289 struct sk_buff *skb, 1290 unsigned int num) 1291 { 1292 return smp_processor_id() % num; 1293 } 1294 1295 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1296 struct sk_buff *skb, 1297 unsigned int num) 1298 { 1299 return prandom_u32_max(num); 1300 } 1301 1302 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1303 struct sk_buff *skb, 1304 unsigned int idx, unsigned int skip, 1305 unsigned int num) 1306 { 1307 unsigned int i, j; 1308 1309 i = j = min_t(int, f->next[idx], num - 1); 1310 do { 1311 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) { 1312 if (i != j) 1313 f->next[idx] = i; 1314 return i; 1315 } 1316 if (++i == num) 1317 i = 0; 1318 } while (i != j); 1319 1320 return idx; 1321 } 1322 1323 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1324 struct sk_buff *skb, 1325 unsigned int num) 1326 { 1327 return skb_get_queue_mapping(skb) % num; 1328 } 1329 1330 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1331 { 1332 return f->flags & (flag >> 8); 1333 } 1334 1335 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1336 struct packet_type *pt, struct net_device *orig_dev) 1337 { 1338 struct packet_fanout *f = pt->af_packet_priv; 1339 unsigned int num = f->num_members; 1340 struct packet_sock *po; 1341 unsigned int idx; 1342 1343 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1344 !num) { 1345 kfree_skb(skb); 1346 return 0; 1347 } 1348 1349 switch (f->type) { 1350 case PACKET_FANOUT_HASH: 1351 default: 1352 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1353 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1354 if (!skb) 1355 return 0; 1356 } 1357 idx = fanout_demux_hash(f, skb, num); 1358 break; 1359 case PACKET_FANOUT_LB: 1360 idx = fanout_demux_lb(f, skb, num); 1361 break; 1362 case PACKET_FANOUT_CPU: 1363 idx = fanout_demux_cpu(f, skb, num); 1364 break; 1365 case PACKET_FANOUT_RND: 1366 idx = fanout_demux_rnd(f, skb, num); 1367 break; 1368 case PACKET_FANOUT_QM: 1369 idx = fanout_demux_qm(f, skb, num); 1370 break; 1371 case PACKET_FANOUT_ROLLOVER: 1372 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num); 1373 break; 1374 } 1375 1376 po = pkt_sk(f->arr[idx]); 1377 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) && 1378 unlikely(!packet_rcv_has_room(po, skb))) { 1379 idx = fanout_demux_rollover(f, skb, idx, idx, num); 1380 po = pkt_sk(f->arr[idx]); 1381 } 1382 1383 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1384 } 1385 1386 DEFINE_MUTEX(fanout_mutex); 1387 EXPORT_SYMBOL_GPL(fanout_mutex); 1388 static LIST_HEAD(fanout_list); 1389 1390 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1391 { 1392 struct packet_fanout *f = po->fanout; 1393 1394 spin_lock(&f->lock); 1395 f->arr[f->num_members] = sk; 1396 smp_wmb(); 1397 f->num_members++; 1398 spin_unlock(&f->lock); 1399 } 1400 1401 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1402 { 1403 struct packet_fanout *f = po->fanout; 1404 int i; 1405 1406 spin_lock(&f->lock); 1407 for (i = 0; i < f->num_members; i++) { 1408 if (f->arr[i] == sk) 1409 break; 1410 } 1411 BUG_ON(i >= f->num_members); 1412 f->arr[i] = f->arr[f->num_members - 1]; 1413 f->num_members--; 1414 spin_unlock(&f->lock); 1415 } 1416 1417 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1418 { 1419 if (ptype->af_packet_priv == (void *)((struct packet_sock *)sk)->fanout) 1420 return true; 1421 1422 return false; 1423 } 1424 1425 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1426 { 1427 struct packet_sock *po = pkt_sk(sk); 1428 struct packet_fanout *f, *match; 1429 u8 type = type_flags & 0xff; 1430 u8 flags = type_flags >> 8; 1431 int err; 1432 1433 switch (type) { 1434 case PACKET_FANOUT_ROLLOVER: 1435 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1436 return -EINVAL; 1437 case PACKET_FANOUT_HASH: 1438 case PACKET_FANOUT_LB: 1439 case PACKET_FANOUT_CPU: 1440 case PACKET_FANOUT_RND: 1441 case PACKET_FANOUT_QM: 1442 break; 1443 default: 1444 return -EINVAL; 1445 } 1446 1447 if (!po->running) 1448 return -EINVAL; 1449 1450 if (po->fanout) 1451 return -EALREADY; 1452 1453 mutex_lock(&fanout_mutex); 1454 match = NULL; 1455 list_for_each_entry(f, &fanout_list, list) { 1456 if (f->id == id && 1457 read_pnet(&f->net) == sock_net(sk)) { 1458 match = f; 1459 break; 1460 } 1461 } 1462 err = -EINVAL; 1463 if (match && match->flags != flags) 1464 goto out; 1465 if (!match) { 1466 err = -ENOMEM; 1467 match = kzalloc(sizeof(*match), GFP_KERNEL); 1468 if (!match) 1469 goto out; 1470 write_pnet(&match->net, sock_net(sk)); 1471 match->id = id; 1472 match->type = type; 1473 match->flags = flags; 1474 atomic_set(&match->rr_cur, 0); 1475 INIT_LIST_HEAD(&match->list); 1476 spin_lock_init(&match->lock); 1477 atomic_set(&match->sk_ref, 0); 1478 match->prot_hook.type = po->prot_hook.type; 1479 match->prot_hook.dev = po->prot_hook.dev; 1480 match->prot_hook.func = packet_rcv_fanout; 1481 match->prot_hook.af_packet_priv = match; 1482 match->prot_hook.id_match = match_fanout_group; 1483 dev_add_pack(&match->prot_hook); 1484 list_add(&match->list, &fanout_list); 1485 } 1486 err = -EINVAL; 1487 if (match->type == type && 1488 match->prot_hook.type == po->prot_hook.type && 1489 match->prot_hook.dev == po->prot_hook.dev) { 1490 err = -ENOSPC; 1491 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1492 __dev_remove_pack(&po->prot_hook); 1493 po->fanout = match; 1494 atomic_inc(&match->sk_ref); 1495 __fanout_link(sk, po); 1496 err = 0; 1497 } 1498 } 1499 out: 1500 mutex_unlock(&fanout_mutex); 1501 return err; 1502 } 1503 1504 static void fanout_release(struct sock *sk) 1505 { 1506 struct packet_sock *po = pkt_sk(sk); 1507 struct packet_fanout *f; 1508 1509 f = po->fanout; 1510 if (!f) 1511 return; 1512 1513 mutex_lock(&fanout_mutex); 1514 po->fanout = NULL; 1515 1516 if (atomic_dec_and_test(&f->sk_ref)) { 1517 list_del(&f->list); 1518 dev_remove_pack(&f->prot_hook); 1519 kfree(f); 1520 } 1521 mutex_unlock(&fanout_mutex); 1522 } 1523 1524 static const struct proto_ops packet_ops; 1525 1526 static const struct proto_ops packet_ops_spkt; 1527 1528 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1529 struct packet_type *pt, struct net_device *orig_dev) 1530 { 1531 struct sock *sk; 1532 struct sockaddr_pkt *spkt; 1533 1534 /* 1535 * When we registered the protocol we saved the socket in the data 1536 * field for just this event. 1537 */ 1538 1539 sk = pt->af_packet_priv; 1540 1541 /* 1542 * Yank back the headers [hope the device set this 1543 * right or kerboom...] 1544 * 1545 * Incoming packets have ll header pulled, 1546 * push it back. 1547 * 1548 * For outgoing ones skb->data == skb_mac_header(skb) 1549 * so that this procedure is noop. 1550 */ 1551 1552 if (skb->pkt_type == PACKET_LOOPBACK) 1553 goto out; 1554 1555 if (!net_eq(dev_net(dev), sock_net(sk))) 1556 goto out; 1557 1558 skb = skb_share_check(skb, GFP_ATOMIC); 1559 if (skb == NULL) 1560 goto oom; 1561 1562 /* drop any routing info */ 1563 skb_dst_drop(skb); 1564 1565 /* drop conntrack reference */ 1566 nf_reset(skb); 1567 1568 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1569 1570 skb_push(skb, skb->data - skb_mac_header(skb)); 1571 1572 /* 1573 * The SOCK_PACKET socket receives _all_ frames. 1574 */ 1575 1576 spkt->spkt_family = dev->type; 1577 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1578 spkt->spkt_protocol = skb->protocol; 1579 1580 /* 1581 * Charge the memory to the socket. This is done specifically 1582 * to prevent sockets using all the memory up. 1583 */ 1584 1585 if (sock_queue_rcv_skb(sk, skb) == 0) 1586 return 0; 1587 1588 out: 1589 kfree_skb(skb); 1590 oom: 1591 return 0; 1592 } 1593 1594 1595 /* 1596 * Output a raw packet to a device layer. This bypasses all the other 1597 * protocol layers and you must therefore supply it with a complete frame 1598 */ 1599 1600 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1601 struct msghdr *msg, size_t len) 1602 { 1603 struct sock *sk = sock->sk; 1604 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1605 struct sk_buff *skb = NULL; 1606 struct net_device *dev; 1607 __be16 proto = 0; 1608 int err; 1609 int extra_len = 0; 1610 1611 /* 1612 * Get and verify the address. 1613 */ 1614 1615 if (saddr) { 1616 if (msg->msg_namelen < sizeof(struct sockaddr)) 1617 return -EINVAL; 1618 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1619 proto = saddr->spkt_protocol; 1620 } else 1621 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1622 1623 /* 1624 * Find the device first to size check it 1625 */ 1626 1627 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1628 retry: 1629 rcu_read_lock(); 1630 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1631 err = -ENODEV; 1632 if (dev == NULL) 1633 goto out_unlock; 1634 1635 err = -ENETDOWN; 1636 if (!(dev->flags & IFF_UP)) 1637 goto out_unlock; 1638 1639 /* 1640 * You may not queue a frame bigger than the mtu. This is the lowest level 1641 * raw protocol and you must do your own fragmentation at this level. 1642 */ 1643 1644 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1645 if (!netif_supports_nofcs(dev)) { 1646 err = -EPROTONOSUPPORT; 1647 goto out_unlock; 1648 } 1649 extra_len = 4; /* We're doing our own CRC */ 1650 } 1651 1652 err = -EMSGSIZE; 1653 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1654 goto out_unlock; 1655 1656 if (!skb) { 1657 size_t reserved = LL_RESERVED_SPACE(dev); 1658 int tlen = dev->needed_tailroom; 1659 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1660 1661 rcu_read_unlock(); 1662 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1663 if (skb == NULL) 1664 return -ENOBUFS; 1665 /* FIXME: Save some space for broken drivers that write a hard 1666 * header at transmission time by themselves. PPP is the notable 1667 * one here. This should really be fixed at the driver level. 1668 */ 1669 skb_reserve(skb, reserved); 1670 skb_reset_network_header(skb); 1671 1672 /* Try to align data part correctly */ 1673 if (hhlen) { 1674 skb->data -= hhlen; 1675 skb->tail -= hhlen; 1676 if (len < hhlen) 1677 skb_reset_network_header(skb); 1678 } 1679 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1680 if (err) 1681 goto out_free; 1682 goto retry; 1683 } 1684 1685 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1686 /* Earlier code assumed this would be a VLAN pkt, 1687 * double-check this now that we have the actual 1688 * packet in hand. 1689 */ 1690 struct ethhdr *ehdr; 1691 skb_reset_mac_header(skb); 1692 ehdr = eth_hdr(skb); 1693 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1694 err = -EMSGSIZE; 1695 goto out_unlock; 1696 } 1697 } 1698 1699 skb->protocol = proto; 1700 skb->dev = dev; 1701 skb->priority = sk->sk_priority; 1702 skb->mark = sk->sk_mark; 1703 1704 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1705 1706 if (unlikely(extra_len == 4)) 1707 skb->no_fcs = 1; 1708 1709 skb_probe_transport_header(skb, 0); 1710 1711 dev_queue_xmit(skb); 1712 rcu_read_unlock(); 1713 return len; 1714 1715 out_unlock: 1716 rcu_read_unlock(); 1717 out_free: 1718 kfree_skb(skb); 1719 return err; 1720 } 1721 1722 static unsigned int run_filter(const struct sk_buff *skb, 1723 const struct sock *sk, 1724 unsigned int res) 1725 { 1726 struct sk_filter *filter; 1727 1728 rcu_read_lock(); 1729 filter = rcu_dereference(sk->sk_filter); 1730 if (filter != NULL) 1731 res = SK_RUN_FILTER(filter, skb); 1732 rcu_read_unlock(); 1733 1734 return res; 1735 } 1736 1737 /* 1738 * This function makes lazy skb cloning in hope that most of packets 1739 * are discarded by BPF. 1740 * 1741 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1742 * and skb->cb are mangled. It works because (and until) packets 1743 * falling here are owned by current CPU. Output packets are cloned 1744 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1745 * sequencially, so that if we return skb to original state on exit, 1746 * we will not harm anyone. 1747 */ 1748 1749 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1750 struct packet_type *pt, struct net_device *orig_dev) 1751 { 1752 struct sock *sk; 1753 struct sockaddr_ll *sll; 1754 struct packet_sock *po; 1755 u8 *skb_head = skb->data; 1756 int skb_len = skb->len; 1757 unsigned int snaplen, res; 1758 1759 if (skb->pkt_type == PACKET_LOOPBACK) 1760 goto drop; 1761 1762 sk = pt->af_packet_priv; 1763 po = pkt_sk(sk); 1764 1765 if (!net_eq(dev_net(dev), sock_net(sk))) 1766 goto drop; 1767 1768 skb->dev = dev; 1769 1770 if (dev->header_ops) { 1771 /* The device has an explicit notion of ll header, 1772 * exported to higher levels. 1773 * 1774 * Otherwise, the device hides details of its frame 1775 * structure, so that corresponding packet head is 1776 * never delivered to user. 1777 */ 1778 if (sk->sk_type != SOCK_DGRAM) 1779 skb_push(skb, skb->data - skb_mac_header(skb)); 1780 else if (skb->pkt_type == PACKET_OUTGOING) { 1781 /* Special case: outgoing packets have ll header at head */ 1782 skb_pull(skb, skb_network_offset(skb)); 1783 } 1784 } 1785 1786 snaplen = skb->len; 1787 1788 res = run_filter(skb, sk, snaplen); 1789 if (!res) 1790 goto drop_n_restore; 1791 if (snaplen > res) 1792 snaplen = res; 1793 1794 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1795 goto drop_n_acct; 1796 1797 if (skb_shared(skb)) { 1798 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1799 if (nskb == NULL) 1800 goto drop_n_acct; 1801 1802 if (skb_head != skb->data) { 1803 skb->data = skb_head; 1804 skb->len = skb_len; 1805 } 1806 consume_skb(skb); 1807 skb = nskb; 1808 } 1809 1810 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1811 sizeof(skb->cb)); 1812 1813 sll = &PACKET_SKB_CB(skb)->sa.ll; 1814 sll->sll_family = AF_PACKET; 1815 sll->sll_hatype = dev->type; 1816 sll->sll_protocol = skb->protocol; 1817 sll->sll_pkttype = skb->pkt_type; 1818 if (unlikely(po->origdev)) 1819 sll->sll_ifindex = orig_dev->ifindex; 1820 else 1821 sll->sll_ifindex = dev->ifindex; 1822 1823 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1824 1825 PACKET_SKB_CB(skb)->origlen = skb->len; 1826 1827 if (pskb_trim(skb, snaplen)) 1828 goto drop_n_acct; 1829 1830 skb_set_owner_r(skb, sk); 1831 skb->dev = NULL; 1832 skb_dst_drop(skb); 1833 1834 /* drop conntrack reference */ 1835 nf_reset(skb); 1836 1837 spin_lock(&sk->sk_receive_queue.lock); 1838 po->stats.stats1.tp_packets++; 1839 skb->dropcount = atomic_read(&sk->sk_drops); 1840 __skb_queue_tail(&sk->sk_receive_queue, skb); 1841 spin_unlock(&sk->sk_receive_queue.lock); 1842 sk->sk_data_ready(sk); 1843 return 0; 1844 1845 drop_n_acct: 1846 spin_lock(&sk->sk_receive_queue.lock); 1847 po->stats.stats1.tp_drops++; 1848 atomic_inc(&sk->sk_drops); 1849 spin_unlock(&sk->sk_receive_queue.lock); 1850 1851 drop_n_restore: 1852 if (skb_head != skb->data && skb_shared(skb)) { 1853 skb->data = skb_head; 1854 skb->len = skb_len; 1855 } 1856 drop: 1857 consume_skb(skb); 1858 return 0; 1859 } 1860 1861 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1862 struct packet_type *pt, struct net_device *orig_dev) 1863 { 1864 struct sock *sk; 1865 struct packet_sock *po; 1866 struct sockaddr_ll *sll; 1867 union tpacket_uhdr h; 1868 u8 *skb_head = skb->data; 1869 int skb_len = skb->len; 1870 unsigned int snaplen, res; 1871 unsigned long status = TP_STATUS_USER; 1872 unsigned short macoff, netoff, hdrlen; 1873 struct sk_buff *copy_skb = NULL; 1874 struct timespec ts; 1875 __u32 ts_status; 1876 1877 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 1878 * We may add members to them until current aligned size without forcing 1879 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 1880 */ 1881 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 1882 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 1883 1884 if (skb->pkt_type == PACKET_LOOPBACK) 1885 goto drop; 1886 1887 sk = pt->af_packet_priv; 1888 po = pkt_sk(sk); 1889 1890 if (!net_eq(dev_net(dev), sock_net(sk))) 1891 goto drop; 1892 1893 if (dev->header_ops) { 1894 if (sk->sk_type != SOCK_DGRAM) 1895 skb_push(skb, skb->data - skb_mac_header(skb)); 1896 else if (skb->pkt_type == PACKET_OUTGOING) { 1897 /* Special case: outgoing packets have ll header at head */ 1898 skb_pull(skb, skb_network_offset(skb)); 1899 } 1900 } 1901 1902 if (skb->ip_summed == CHECKSUM_PARTIAL) 1903 status |= TP_STATUS_CSUMNOTREADY; 1904 1905 snaplen = skb->len; 1906 1907 res = run_filter(skb, sk, snaplen); 1908 if (!res) 1909 goto drop_n_restore; 1910 if (snaplen > res) 1911 snaplen = res; 1912 1913 if (sk->sk_type == SOCK_DGRAM) { 1914 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1915 po->tp_reserve; 1916 } else { 1917 unsigned int maclen = skb_network_offset(skb); 1918 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1919 (maclen < 16 ? 16 : maclen)) + 1920 po->tp_reserve; 1921 macoff = netoff - maclen; 1922 } 1923 if (po->tp_version <= TPACKET_V2) { 1924 if (macoff + snaplen > po->rx_ring.frame_size) { 1925 if (po->copy_thresh && 1926 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1927 if (skb_shared(skb)) { 1928 copy_skb = skb_clone(skb, GFP_ATOMIC); 1929 } else { 1930 copy_skb = skb_get(skb); 1931 skb_head = skb->data; 1932 } 1933 if (copy_skb) 1934 skb_set_owner_r(copy_skb, sk); 1935 } 1936 snaplen = po->rx_ring.frame_size - macoff; 1937 if ((int)snaplen < 0) 1938 snaplen = 0; 1939 } 1940 } else if (unlikely(macoff + snaplen > 1941 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 1942 u32 nval; 1943 1944 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 1945 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 1946 snaplen, nval, macoff); 1947 snaplen = nval; 1948 if (unlikely((int)snaplen < 0)) { 1949 snaplen = 0; 1950 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 1951 } 1952 } 1953 spin_lock(&sk->sk_receive_queue.lock); 1954 h.raw = packet_current_rx_frame(po, skb, 1955 TP_STATUS_KERNEL, (macoff+snaplen)); 1956 if (!h.raw) 1957 goto ring_is_full; 1958 if (po->tp_version <= TPACKET_V2) { 1959 packet_increment_rx_head(po, &po->rx_ring); 1960 /* 1961 * LOSING will be reported till you read the stats, 1962 * because it's COR - Clear On Read. 1963 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1964 * at packet level. 1965 */ 1966 if (po->stats.stats1.tp_drops) 1967 status |= TP_STATUS_LOSING; 1968 } 1969 po->stats.stats1.tp_packets++; 1970 if (copy_skb) { 1971 status |= TP_STATUS_COPY; 1972 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1973 } 1974 spin_unlock(&sk->sk_receive_queue.lock); 1975 1976 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1977 1978 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 1979 getnstimeofday(&ts); 1980 1981 status |= ts_status; 1982 1983 switch (po->tp_version) { 1984 case TPACKET_V1: 1985 h.h1->tp_len = skb->len; 1986 h.h1->tp_snaplen = snaplen; 1987 h.h1->tp_mac = macoff; 1988 h.h1->tp_net = netoff; 1989 h.h1->tp_sec = ts.tv_sec; 1990 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 1991 hdrlen = sizeof(*h.h1); 1992 break; 1993 case TPACKET_V2: 1994 h.h2->tp_len = skb->len; 1995 h.h2->tp_snaplen = snaplen; 1996 h.h2->tp_mac = macoff; 1997 h.h2->tp_net = netoff; 1998 h.h2->tp_sec = ts.tv_sec; 1999 h.h2->tp_nsec = ts.tv_nsec; 2000 if (vlan_tx_tag_present(skb)) { 2001 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 2002 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2003 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2004 } else { 2005 h.h2->tp_vlan_tci = 0; 2006 h.h2->tp_vlan_tpid = 0; 2007 } 2008 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2009 hdrlen = sizeof(*h.h2); 2010 break; 2011 case TPACKET_V3: 2012 /* tp_nxt_offset,vlan are already populated above. 2013 * So DONT clear those fields here 2014 */ 2015 h.h3->tp_status |= status; 2016 h.h3->tp_len = skb->len; 2017 h.h3->tp_snaplen = snaplen; 2018 h.h3->tp_mac = macoff; 2019 h.h3->tp_net = netoff; 2020 h.h3->tp_sec = ts.tv_sec; 2021 h.h3->tp_nsec = ts.tv_nsec; 2022 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2023 hdrlen = sizeof(*h.h3); 2024 break; 2025 default: 2026 BUG(); 2027 } 2028 2029 sll = h.raw + TPACKET_ALIGN(hdrlen); 2030 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2031 sll->sll_family = AF_PACKET; 2032 sll->sll_hatype = dev->type; 2033 sll->sll_protocol = skb->protocol; 2034 sll->sll_pkttype = skb->pkt_type; 2035 if (unlikely(po->origdev)) 2036 sll->sll_ifindex = orig_dev->ifindex; 2037 else 2038 sll->sll_ifindex = dev->ifindex; 2039 2040 smp_mb(); 2041 2042 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2043 if (po->tp_version <= TPACKET_V2) { 2044 u8 *start, *end; 2045 2046 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2047 macoff + snaplen); 2048 2049 for (start = h.raw; start < end; start += PAGE_SIZE) 2050 flush_dcache_page(pgv_to_page(start)); 2051 } 2052 smp_wmb(); 2053 #endif 2054 2055 if (po->tp_version <= TPACKET_V2) 2056 __packet_set_status(po, h.raw, status); 2057 else 2058 prb_clear_blk_fill_status(&po->rx_ring); 2059 2060 sk->sk_data_ready(sk); 2061 2062 drop_n_restore: 2063 if (skb_head != skb->data && skb_shared(skb)) { 2064 skb->data = skb_head; 2065 skb->len = skb_len; 2066 } 2067 drop: 2068 kfree_skb(skb); 2069 return 0; 2070 2071 ring_is_full: 2072 po->stats.stats1.tp_drops++; 2073 spin_unlock(&sk->sk_receive_queue.lock); 2074 2075 sk->sk_data_ready(sk); 2076 kfree_skb(copy_skb); 2077 goto drop_n_restore; 2078 } 2079 2080 static void tpacket_destruct_skb(struct sk_buff *skb) 2081 { 2082 struct packet_sock *po = pkt_sk(skb->sk); 2083 2084 if (likely(po->tx_ring.pg_vec)) { 2085 void *ph; 2086 __u32 ts; 2087 2088 ph = skb_shinfo(skb)->destructor_arg; 2089 packet_dec_pending(&po->tx_ring); 2090 2091 ts = __packet_set_timestamp(po, ph, skb); 2092 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2093 } 2094 2095 sock_wfree(skb); 2096 } 2097 2098 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2099 void *frame, struct net_device *dev, int size_max, 2100 __be16 proto, unsigned char *addr, int hlen) 2101 { 2102 union tpacket_uhdr ph; 2103 int to_write, offset, len, tp_len, nr_frags, len_max; 2104 struct socket *sock = po->sk.sk_socket; 2105 struct page *page; 2106 void *data; 2107 int err; 2108 2109 ph.raw = frame; 2110 2111 skb->protocol = proto; 2112 skb->dev = dev; 2113 skb->priority = po->sk.sk_priority; 2114 skb->mark = po->sk.sk_mark; 2115 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 2116 skb_shinfo(skb)->destructor_arg = ph.raw; 2117 2118 switch (po->tp_version) { 2119 case TPACKET_V2: 2120 tp_len = ph.h2->tp_len; 2121 break; 2122 default: 2123 tp_len = ph.h1->tp_len; 2124 break; 2125 } 2126 if (unlikely(tp_len > size_max)) { 2127 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2128 return -EMSGSIZE; 2129 } 2130 2131 skb_reserve(skb, hlen); 2132 skb_reset_network_header(skb); 2133 2134 if (!packet_use_direct_xmit(po)) 2135 skb_probe_transport_header(skb, 0); 2136 if (unlikely(po->tp_tx_has_off)) { 2137 int off_min, off_max, off; 2138 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2139 off_max = po->tx_ring.frame_size - tp_len; 2140 if (sock->type == SOCK_DGRAM) { 2141 switch (po->tp_version) { 2142 case TPACKET_V2: 2143 off = ph.h2->tp_net; 2144 break; 2145 default: 2146 off = ph.h1->tp_net; 2147 break; 2148 } 2149 } else { 2150 switch (po->tp_version) { 2151 case TPACKET_V2: 2152 off = ph.h2->tp_mac; 2153 break; 2154 default: 2155 off = ph.h1->tp_mac; 2156 break; 2157 } 2158 } 2159 if (unlikely((off < off_min) || (off_max < off))) 2160 return -EINVAL; 2161 data = ph.raw + off; 2162 } else { 2163 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 2164 } 2165 to_write = tp_len; 2166 2167 if (sock->type == SOCK_DGRAM) { 2168 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2169 NULL, tp_len); 2170 if (unlikely(err < 0)) 2171 return -EINVAL; 2172 } else if (dev->hard_header_len) { 2173 /* net device doesn't like empty head */ 2174 if (unlikely(tp_len <= dev->hard_header_len)) { 2175 pr_err("packet size is too short (%d < %d)\n", 2176 tp_len, dev->hard_header_len); 2177 return -EINVAL; 2178 } 2179 2180 skb_push(skb, dev->hard_header_len); 2181 err = skb_store_bits(skb, 0, data, 2182 dev->hard_header_len); 2183 if (unlikely(err)) 2184 return err; 2185 2186 data += dev->hard_header_len; 2187 to_write -= dev->hard_header_len; 2188 } 2189 2190 offset = offset_in_page(data); 2191 len_max = PAGE_SIZE - offset; 2192 len = ((to_write > len_max) ? len_max : to_write); 2193 2194 skb->data_len = to_write; 2195 skb->len += to_write; 2196 skb->truesize += to_write; 2197 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2198 2199 while (likely(to_write)) { 2200 nr_frags = skb_shinfo(skb)->nr_frags; 2201 2202 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2203 pr_err("Packet exceed the number of skb frags(%lu)\n", 2204 MAX_SKB_FRAGS); 2205 return -EFAULT; 2206 } 2207 2208 page = pgv_to_page(data); 2209 data += len; 2210 flush_dcache_page(page); 2211 get_page(page); 2212 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2213 to_write -= len; 2214 offset = 0; 2215 len_max = PAGE_SIZE; 2216 len = ((to_write > len_max) ? len_max : to_write); 2217 } 2218 2219 return tp_len; 2220 } 2221 2222 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2223 { 2224 struct sk_buff *skb; 2225 struct net_device *dev; 2226 __be16 proto; 2227 int err, reserve = 0; 2228 void *ph; 2229 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2230 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2231 int tp_len, size_max; 2232 unsigned char *addr; 2233 int len_sum = 0; 2234 int status = TP_STATUS_AVAILABLE; 2235 int hlen, tlen; 2236 2237 mutex_lock(&po->pg_vec_lock); 2238 2239 if (likely(saddr == NULL)) { 2240 dev = packet_cached_dev_get(po); 2241 proto = po->num; 2242 addr = NULL; 2243 } else { 2244 err = -EINVAL; 2245 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2246 goto out; 2247 if (msg->msg_namelen < (saddr->sll_halen 2248 + offsetof(struct sockaddr_ll, 2249 sll_addr))) 2250 goto out; 2251 proto = saddr->sll_protocol; 2252 addr = saddr->sll_addr; 2253 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2254 } 2255 2256 err = -ENXIO; 2257 if (unlikely(dev == NULL)) 2258 goto out; 2259 err = -ENETDOWN; 2260 if (unlikely(!(dev->flags & IFF_UP))) 2261 goto out_put; 2262 2263 reserve = dev->hard_header_len + VLAN_HLEN; 2264 size_max = po->tx_ring.frame_size 2265 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2266 2267 if (size_max > dev->mtu + reserve) 2268 size_max = dev->mtu + reserve; 2269 2270 do { 2271 ph = packet_current_frame(po, &po->tx_ring, 2272 TP_STATUS_SEND_REQUEST); 2273 if (unlikely(ph == NULL)) { 2274 if (need_wait && need_resched()) 2275 schedule(); 2276 continue; 2277 } 2278 2279 status = TP_STATUS_SEND_REQUEST; 2280 hlen = LL_RESERVED_SPACE(dev); 2281 tlen = dev->needed_tailroom; 2282 skb = sock_alloc_send_skb(&po->sk, 2283 hlen + tlen + sizeof(struct sockaddr_ll), 2284 0, &err); 2285 2286 if (unlikely(skb == NULL)) 2287 goto out_status; 2288 2289 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2290 addr, hlen); 2291 if (tp_len > dev->mtu + dev->hard_header_len) { 2292 struct ethhdr *ehdr; 2293 /* Earlier code assumed this would be a VLAN pkt, 2294 * double-check this now that we have the actual 2295 * packet in hand. 2296 */ 2297 2298 skb_reset_mac_header(skb); 2299 ehdr = eth_hdr(skb); 2300 if (ehdr->h_proto != htons(ETH_P_8021Q)) 2301 tp_len = -EMSGSIZE; 2302 } 2303 if (unlikely(tp_len < 0)) { 2304 if (po->tp_loss) { 2305 __packet_set_status(po, ph, 2306 TP_STATUS_AVAILABLE); 2307 packet_increment_head(&po->tx_ring); 2308 kfree_skb(skb); 2309 continue; 2310 } else { 2311 status = TP_STATUS_WRONG_FORMAT; 2312 err = tp_len; 2313 goto out_status; 2314 } 2315 } 2316 2317 packet_pick_tx_queue(dev, skb); 2318 2319 skb->destructor = tpacket_destruct_skb; 2320 __packet_set_status(po, ph, TP_STATUS_SENDING); 2321 packet_inc_pending(&po->tx_ring); 2322 2323 status = TP_STATUS_SEND_REQUEST; 2324 err = po->xmit(skb); 2325 if (unlikely(err > 0)) { 2326 err = net_xmit_errno(err); 2327 if (err && __packet_get_status(po, ph) == 2328 TP_STATUS_AVAILABLE) { 2329 /* skb was destructed already */ 2330 skb = NULL; 2331 goto out_status; 2332 } 2333 /* 2334 * skb was dropped but not destructed yet; 2335 * let's treat it like congestion or err < 0 2336 */ 2337 err = 0; 2338 } 2339 packet_increment_head(&po->tx_ring); 2340 len_sum += tp_len; 2341 } while (likely((ph != NULL) || 2342 /* Note: packet_read_pending() might be slow if we have 2343 * to call it as it's per_cpu variable, but in fast-path 2344 * we already short-circuit the loop with the first 2345 * condition, and luckily don't have to go that path 2346 * anyway. 2347 */ 2348 (need_wait && packet_read_pending(&po->tx_ring)))); 2349 2350 err = len_sum; 2351 goto out_put; 2352 2353 out_status: 2354 __packet_set_status(po, ph, status); 2355 kfree_skb(skb); 2356 out_put: 2357 dev_put(dev); 2358 out: 2359 mutex_unlock(&po->pg_vec_lock); 2360 return err; 2361 } 2362 2363 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2364 size_t reserve, size_t len, 2365 size_t linear, int noblock, 2366 int *err) 2367 { 2368 struct sk_buff *skb; 2369 2370 /* Under a page? Don't bother with paged skb. */ 2371 if (prepad + len < PAGE_SIZE || !linear) 2372 linear = len; 2373 2374 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2375 err, 0); 2376 if (!skb) 2377 return NULL; 2378 2379 skb_reserve(skb, reserve); 2380 skb_put(skb, linear); 2381 skb->data_len = len - linear; 2382 skb->len += len - linear; 2383 2384 return skb; 2385 } 2386 2387 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2388 { 2389 struct sock *sk = sock->sk; 2390 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2391 struct sk_buff *skb; 2392 struct net_device *dev; 2393 __be16 proto; 2394 unsigned char *addr; 2395 int err, reserve = 0; 2396 struct virtio_net_hdr vnet_hdr = { 0 }; 2397 int offset = 0; 2398 int vnet_hdr_len; 2399 struct packet_sock *po = pkt_sk(sk); 2400 unsigned short gso_type = 0; 2401 int hlen, tlen; 2402 int extra_len = 0; 2403 2404 /* 2405 * Get and verify the address. 2406 */ 2407 2408 if (likely(saddr == NULL)) { 2409 dev = packet_cached_dev_get(po); 2410 proto = po->num; 2411 addr = NULL; 2412 } else { 2413 err = -EINVAL; 2414 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2415 goto out; 2416 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2417 goto out; 2418 proto = saddr->sll_protocol; 2419 addr = saddr->sll_addr; 2420 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2421 } 2422 2423 err = -ENXIO; 2424 if (unlikely(dev == NULL)) 2425 goto out_unlock; 2426 err = -ENETDOWN; 2427 if (unlikely(!(dev->flags & IFF_UP))) 2428 goto out_unlock; 2429 2430 if (sock->type == SOCK_RAW) 2431 reserve = dev->hard_header_len; 2432 if (po->has_vnet_hdr) { 2433 vnet_hdr_len = sizeof(vnet_hdr); 2434 2435 err = -EINVAL; 2436 if (len < vnet_hdr_len) 2437 goto out_unlock; 2438 2439 len -= vnet_hdr_len; 2440 2441 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2442 vnet_hdr_len); 2443 if (err < 0) 2444 goto out_unlock; 2445 2446 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2447 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2448 vnet_hdr.hdr_len)) 2449 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2450 vnet_hdr.csum_offset + 2; 2451 2452 err = -EINVAL; 2453 if (vnet_hdr.hdr_len > len) 2454 goto out_unlock; 2455 2456 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2457 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2458 case VIRTIO_NET_HDR_GSO_TCPV4: 2459 gso_type = SKB_GSO_TCPV4; 2460 break; 2461 case VIRTIO_NET_HDR_GSO_TCPV6: 2462 gso_type = SKB_GSO_TCPV6; 2463 break; 2464 case VIRTIO_NET_HDR_GSO_UDP: 2465 gso_type = SKB_GSO_UDP; 2466 break; 2467 default: 2468 goto out_unlock; 2469 } 2470 2471 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2472 gso_type |= SKB_GSO_TCP_ECN; 2473 2474 if (vnet_hdr.gso_size == 0) 2475 goto out_unlock; 2476 2477 } 2478 } 2479 2480 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2481 if (!netif_supports_nofcs(dev)) { 2482 err = -EPROTONOSUPPORT; 2483 goto out_unlock; 2484 } 2485 extra_len = 4; /* We're doing our own CRC */ 2486 } 2487 2488 err = -EMSGSIZE; 2489 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2490 goto out_unlock; 2491 2492 err = -ENOBUFS; 2493 hlen = LL_RESERVED_SPACE(dev); 2494 tlen = dev->needed_tailroom; 2495 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2496 msg->msg_flags & MSG_DONTWAIT, &err); 2497 if (skb == NULL) 2498 goto out_unlock; 2499 2500 skb_set_network_header(skb, reserve); 2501 2502 err = -EINVAL; 2503 if (sock->type == SOCK_DGRAM && 2504 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2505 goto out_free; 2506 2507 /* Returns -EFAULT on error */ 2508 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2509 if (err) 2510 goto out_free; 2511 2512 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2513 2514 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2515 /* Earlier code assumed this would be a VLAN pkt, 2516 * double-check this now that we have the actual 2517 * packet in hand. 2518 */ 2519 struct ethhdr *ehdr; 2520 skb_reset_mac_header(skb); 2521 ehdr = eth_hdr(skb); 2522 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2523 err = -EMSGSIZE; 2524 goto out_free; 2525 } 2526 } 2527 2528 skb->protocol = proto; 2529 skb->dev = dev; 2530 skb->priority = sk->sk_priority; 2531 skb->mark = sk->sk_mark; 2532 2533 packet_pick_tx_queue(dev, skb); 2534 2535 if (po->has_vnet_hdr) { 2536 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2537 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2538 vnet_hdr.csum_offset)) { 2539 err = -EINVAL; 2540 goto out_free; 2541 } 2542 } 2543 2544 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2545 skb_shinfo(skb)->gso_type = gso_type; 2546 2547 /* Header must be checked, and gso_segs computed. */ 2548 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2549 skb_shinfo(skb)->gso_segs = 0; 2550 2551 len += vnet_hdr_len; 2552 } 2553 2554 if (!packet_use_direct_xmit(po)) 2555 skb_probe_transport_header(skb, reserve); 2556 if (unlikely(extra_len == 4)) 2557 skb->no_fcs = 1; 2558 2559 err = po->xmit(skb); 2560 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2561 goto out_unlock; 2562 2563 dev_put(dev); 2564 2565 return len; 2566 2567 out_free: 2568 kfree_skb(skb); 2569 out_unlock: 2570 if (dev) 2571 dev_put(dev); 2572 out: 2573 return err; 2574 } 2575 2576 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2577 struct msghdr *msg, size_t len) 2578 { 2579 struct sock *sk = sock->sk; 2580 struct packet_sock *po = pkt_sk(sk); 2581 2582 if (po->tx_ring.pg_vec) 2583 return tpacket_snd(po, msg); 2584 else 2585 return packet_snd(sock, msg, len); 2586 } 2587 2588 /* 2589 * Close a PACKET socket. This is fairly simple. We immediately go 2590 * to 'closed' state and remove our protocol entry in the device list. 2591 */ 2592 2593 static int packet_release(struct socket *sock) 2594 { 2595 struct sock *sk = sock->sk; 2596 struct packet_sock *po; 2597 struct net *net; 2598 union tpacket_req_u req_u; 2599 2600 if (!sk) 2601 return 0; 2602 2603 net = sock_net(sk); 2604 po = pkt_sk(sk); 2605 2606 mutex_lock(&net->packet.sklist_lock); 2607 sk_del_node_init_rcu(sk); 2608 mutex_unlock(&net->packet.sklist_lock); 2609 2610 preempt_disable(); 2611 sock_prot_inuse_add(net, sk->sk_prot, -1); 2612 preempt_enable(); 2613 2614 spin_lock(&po->bind_lock); 2615 unregister_prot_hook(sk, false); 2616 packet_cached_dev_reset(po); 2617 2618 if (po->prot_hook.dev) { 2619 dev_put(po->prot_hook.dev); 2620 po->prot_hook.dev = NULL; 2621 } 2622 spin_unlock(&po->bind_lock); 2623 2624 packet_flush_mclist(sk); 2625 2626 if (po->rx_ring.pg_vec) { 2627 memset(&req_u, 0, sizeof(req_u)); 2628 packet_set_ring(sk, &req_u, 1, 0); 2629 } 2630 2631 if (po->tx_ring.pg_vec) { 2632 memset(&req_u, 0, sizeof(req_u)); 2633 packet_set_ring(sk, &req_u, 1, 1); 2634 } 2635 2636 fanout_release(sk); 2637 2638 synchronize_net(); 2639 /* 2640 * Now the socket is dead. No more input will appear. 2641 */ 2642 sock_orphan(sk); 2643 sock->sk = NULL; 2644 2645 /* Purge queues */ 2646 2647 skb_queue_purge(&sk->sk_receive_queue); 2648 packet_free_pending(po); 2649 sk_refcnt_debug_release(sk); 2650 2651 sock_put(sk); 2652 return 0; 2653 } 2654 2655 /* 2656 * Attach a packet hook. 2657 */ 2658 2659 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto) 2660 { 2661 struct packet_sock *po = pkt_sk(sk); 2662 const struct net_device *dev_curr; 2663 __be16 proto_curr; 2664 bool need_rehook; 2665 2666 if (po->fanout) { 2667 if (dev) 2668 dev_put(dev); 2669 2670 return -EINVAL; 2671 } 2672 2673 lock_sock(sk); 2674 spin_lock(&po->bind_lock); 2675 2676 proto_curr = po->prot_hook.type; 2677 dev_curr = po->prot_hook.dev; 2678 2679 need_rehook = proto_curr != proto || dev_curr != dev; 2680 2681 if (need_rehook) { 2682 unregister_prot_hook(sk, true); 2683 2684 po->num = proto; 2685 po->prot_hook.type = proto; 2686 2687 if (po->prot_hook.dev) 2688 dev_put(po->prot_hook.dev); 2689 2690 po->prot_hook.dev = dev; 2691 2692 po->ifindex = dev ? dev->ifindex : 0; 2693 packet_cached_dev_assign(po, dev); 2694 } 2695 2696 if (proto == 0 || !need_rehook) 2697 goto out_unlock; 2698 2699 if (!dev || (dev->flags & IFF_UP)) { 2700 register_prot_hook(sk); 2701 } else { 2702 sk->sk_err = ENETDOWN; 2703 if (!sock_flag(sk, SOCK_DEAD)) 2704 sk->sk_error_report(sk); 2705 } 2706 2707 out_unlock: 2708 spin_unlock(&po->bind_lock); 2709 release_sock(sk); 2710 return 0; 2711 } 2712 2713 /* 2714 * Bind a packet socket to a device 2715 */ 2716 2717 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2718 int addr_len) 2719 { 2720 struct sock *sk = sock->sk; 2721 char name[15]; 2722 struct net_device *dev; 2723 int err = -ENODEV; 2724 2725 /* 2726 * Check legality 2727 */ 2728 2729 if (addr_len != sizeof(struct sockaddr)) 2730 return -EINVAL; 2731 strlcpy(name, uaddr->sa_data, sizeof(name)); 2732 2733 dev = dev_get_by_name(sock_net(sk), name); 2734 if (dev) 2735 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2736 return err; 2737 } 2738 2739 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2740 { 2741 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2742 struct sock *sk = sock->sk; 2743 struct net_device *dev = NULL; 2744 int err; 2745 2746 2747 /* 2748 * Check legality 2749 */ 2750 2751 if (addr_len < sizeof(struct sockaddr_ll)) 2752 return -EINVAL; 2753 if (sll->sll_family != AF_PACKET) 2754 return -EINVAL; 2755 2756 if (sll->sll_ifindex) { 2757 err = -ENODEV; 2758 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2759 if (dev == NULL) 2760 goto out; 2761 } 2762 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2763 2764 out: 2765 return err; 2766 } 2767 2768 static struct proto packet_proto = { 2769 .name = "PACKET", 2770 .owner = THIS_MODULE, 2771 .obj_size = sizeof(struct packet_sock), 2772 }; 2773 2774 /* 2775 * Create a packet of type SOCK_PACKET. 2776 */ 2777 2778 static int packet_create(struct net *net, struct socket *sock, int protocol, 2779 int kern) 2780 { 2781 struct sock *sk; 2782 struct packet_sock *po; 2783 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2784 int err; 2785 2786 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 2787 return -EPERM; 2788 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2789 sock->type != SOCK_PACKET) 2790 return -ESOCKTNOSUPPORT; 2791 2792 sock->state = SS_UNCONNECTED; 2793 2794 err = -ENOBUFS; 2795 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2796 if (sk == NULL) 2797 goto out; 2798 2799 sock->ops = &packet_ops; 2800 if (sock->type == SOCK_PACKET) 2801 sock->ops = &packet_ops_spkt; 2802 2803 sock_init_data(sock, sk); 2804 2805 po = pkt_sk(sk); 2806 sk->sk_family = PF_PACKET; 2807 po->num = proto; 2808 po->xmit = dev_queue_xmit; 2809 2810 err = packet_alloc_pending(po); 2811 if (err) 2812 goto out2; 2813 2814 packet_cached_dev_reset(po); 2815 2816 sk->sk_destruct = packet_sock_destruct; 2817 sk_refcnt_debug_inc(sk); 2818 2819 /* 2820 * Attach a protocol block 2821 */ 2822 2823 spin_lock_init(&po->bind_lock); 2824 mutex_init(&po->pg_vec_lock); 2825 po->prot_hook.func = packet_rcv; 2826 2827 if (sock->type == SOCK_PACKET) 2828 po->prot_hook.func = packet_rcv_spkt; 2829 2830 po->prot_hook.af_packet_priv = sk; 2831 2832 if (proto) { 2833 po->prot_hook.type = proto; 2834 register_prot_hook(sk); 2835 } 2836 2837 mutex_lock(&net->packet.sklist_lock); 2838 sk_add_node_rcu(sk, &net->packet.sklist); 2839 mutex_unlock(&net->packet.sklist_lock); 2840 2841 preempt_disable(); 2842 sock_prot_inuse_add(net, &packet_proto, 1); 2843 preempt_enable(); 2844 2845 return 0; 2846 out2: 2847 sk_free(sk); 2848 out: 2849 return err; 2850 } 2851 2852 /* 2853 * Pull a packet from our receive queue and hand it to the user. 2854 * If necessary we block. 2855 */ 2856 2857 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2858 struct msghdr *msg, size_t len, int flags) 2859 { 2860 struct sock *sk = sock->sk; 2861 struct sk_buff *skb; 2862 int copied, err; 2863 int vnet_hdr_len = 0; 2864 2865 err = -EINVAL; 2866 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2867 goto out; 2868 2869 #if 0 2870 /* What error should we return now? EUNATTACH? */ 2871 if (pkt_sk(sk)->ifindex < 0) 2872 return -ENODEV; 2873 #endif 2874 2875 if (flags & MSG_ERRQUEUE) { 2876 err = sock_recv_errqueue(sk, msg, len, 2877 SOL_PACKET, PACKET_TX_TIMESTAMP); 2878 goto out; 2879 } 2880 2881 /* 2882 * Call the generic datagram receiver. This handles all sorts 2883 * of horrible races and re-entrancy so we can forget about it 2884 * in the protocol layers. 2885 * 2886 * Now it will return ENETDOWN, if device have just gone down, 2887 * but then it will block. 2888 */ 2889 2890 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2891 2892 /* 2893 * An error occurred so return it. Because skb_recv_datagram() 2894 * handles the blocking we don't see and worry about blocking 2895 * retries. 2896 */ 2897 2898 if (skb == NULL) 2899 goto out; 2900 2901 if (pkt_sk(sk)->has_vnet_hdr) { 2902 struct virtio_net_hdr vnet_hdr = { 0 }; 2903 2904 err = -EINVAL; 2905 vnet_hdr_len = sizeof(vnet_hdr); 2906 if (len < vnet_hdr_len) 2907 goto out_free; 2908 2909 len -= vnet_hdr_len; 2910 2911 if (skb_is_gso(skb)) { 2912 struct skb_shared_info *sinfo = skb_shinfo(skb); 2913 2914 /* This is a hint as to how much should be linear. */ 2915 vnet_hdr.hdr_len = skb_headlen(skb); 2916 vnet_hdr.gso_size = sinfo->gso_size; 2917 if (sinfo->gso_type & SKB_GSO_TCPV4) 2918 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2919 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2920 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2921 else if (sinfo->gso_type & SKB_GSO_UDP) 2922 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2923 else if (sinfo->gso_type & SKB_GSO_FCOE) 2924 goto out_free; 2925 else 2926 BUG(); 2927 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2928 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2929 } else 2930 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2931 2932 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2933 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2934 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2935 vnet_hdr.csum_offset = skb->csum_offset; 2936 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2937 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2938 } /* else everything is zero */ 2939 2940 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2941 vnet_hdr_len); 2942 if (err < 0) 2943 goto out_free; 2944 } 2945 2946 /* You lose any data beyond the buffer you gave. If it worries 2947 * a user program they can ask the device for its MTU 2948 * anyway. 2949 */ 2950 copied = skb->len; 2951 if (copied > len) { 2952 copied = len; 2953 msg->msg_flags |= MSG_TRUNC; 2954 } 2955 2956 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2957 if (err) 2958 goto out_free; 2959 2960 sock_recv_ts_and_drops(msg, sk, skb); 2961 2962 if (msg->msg_name) { 2963 /* If the address length field is there to be filled 2964 * in, we fill it in now. 2965 */ 2966 if (sock->type == SOCK_PACKET) { 2967 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 2968 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2969 } else { 2970 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 2971 msg->msg_namelen = sll->sll_halen + 2972 offsetof(struct sockaddr_ll, sll_addr); 2973 } 2974 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2975 msg->msg_namelen); 2976 } 2977 2978 if (pkt_sk(sk)->auxdata) { 2979 struct tpacket_auxdata aux; 2980 2981 aux.tp_status = TP_STATUS_USER; 2982 if (skb->ip_summed == CHECKSUM_PARTIAL) 2983 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2984 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2985 aux.tp_snaplen = skb->len; 2986 aux.tp_mac = 0; 2987 aux.tp_net = skb_network_offset(skb); 2988 if (vlan_tx_tag_present(skb)) { 2989 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2990 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 2991 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2992 } else { 2993 aux.tp_vlan_tci = 0; 2994 aux.tp_vlan_tpid = 0; 2995 } 2996 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2997 } 2998 2999 /* 3000 * Free or return the buffer as appropriate. Again this 3001 * hides all the races and re-entrancy issues from us. 3002 */ 3003 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3004 3005 out_free: 3006 skb_free_datagram(sk, skb); 3007 out: 3008 return err; 3009 } 3010 3011 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3012 int *uaddr_len, int peer) 3013 { 3014 struct net_device *dev; 3015 struct sock *sk = sock->sk; 3016 3017 if (peer) 3018 return -EOPNOTSUPP; 3019 3020 uaddr->sa_family = AF_PACKET; 3021 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3022 rcu_read_lock(); 3023 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3024 if (dev) 3025 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3026 rcu_read_unlock(); 3027 *uaddr_len = sizeof(*uaddr); 3028 3029 return 0; 3030 } 3031 3032 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3033 int *uaddr_len, int peer) 3034 { 3035 struct net_device *dev; 3036 struct sock *sk = sock->sk; 3037 struct packet_sock *po = pkt_sk(sk); 3038 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3039 3040 if (peer) 3041 return -EOPNOTSUPP; 3042 3043 sll->sll_family = AF_PACKET; 3044 sll->sll_ifindex = po->ifindex; 3045 sll->sll_protocol = po->num; 3046 sll->sll_pkttype = 0; 3047 rcu_read_lock(); 3048 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3049 if (dev) { 3050 sll->sll_hatype = dev->type; 3051 sll->sll_halen = dev->addr_len; 3052 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3053 } else { 3054 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3055 sll->sll_halen = 0; 3056 } 3057 rcu_read_unlock(); 3058 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3059 3060 return 0; 3061 } 3062 3063 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3064 int what) 3065 { 3066 switch (i->type) { 3067 case PACKET_MR_MULTICAST: 3068 if (i->alen != dev->addr_len) 3069 return -EINVAL; 3070 if (what > 0) 3071 return dev_mc_add(dev, i->addr); 3072 else 3073 return dev_mc_del(dev, i->addr); 3074 break; 3075 case PACKET_MR_PROMISC: 3076 return dev_set_promiscuity(dev, what); 3077 case PACKET_MR_ALLMULTI: 3078 return dev_set_allmulti(dev, what); 3079 case PACKET_MR_UNICAST: 3080 if (i->alen != dev->addr_len) 3081 return -EINVAL; 3082 if (what > 0) 3083 return dev_uc_add(dev, i->addr); 3084 else 3085 return dev_uc_del(dev, i->addr); 3086 break; 3087 default: 3088 break; 3089 } 3090 return 0; 3091 } 3092 3093 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 3094 { 3095 for ( ; i; i = i->next) { 3096 if (i->ifindex == dev->ifindex) 3097 packet_dev_mc(dev, i, what); 3098 } 3099 } 3100 3101 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3102 { 3103 struct packet_sock *po = pkt_sk(sk); 3104 struct packet_mclist *ml, *i; 3105 struct net_device *dev; 3106 int err; 3107 3108 rtnl_lock(); 3109 3110 err = -ENODEV; 3111 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3112 if (!dev) 3113 goto done; 3114 3115 err = -EINVAL; 3116 if (mreq->mr_alen > dev->addr_len) 3117 goto done; 3118 3119 err = -ENOBUFS; 3120 i = kmalloc(sizeof(*i), GFP_KERNEL); 3121 if (i == NULL) 3122 goto done; 3123 3124 err = 0; 3125 for (ml = po->mclist; ml; ml = ml->next) { 3126 if (ml->ifindex == mreq->mr_ifindex && 3127 ml->type == mreq->mr_type && 3128 ml->alen == mreq->mr_alen && 3129 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3130 ml->count++; 3131 /* Free the new element ... */ 3132 kfree(i); 3133 goto done; 3134 } 3135 } 3136 3137 i->type = mreq->mr_type; 3138 i->ifindex = mreq->mr_ifindex; 3139 i->alen = mreq->mr_alen; 3140 memcpy(i->addr, mreq->mr_address, i->alen); 3141 i->count = 1; 3142 i->next = po->mclist; 3143 po->mclist = i; 3144 err = packet_dev_mc(dev, i, 1); 3145 if (err) { 3146 po->mclist = i->next; 3147 kfree(i); 3148 } 3149 3150 done: 3151 rtnl_unlock(); 3152 return err; 3153 } 3154 3155 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3156 { 3157 struct packet_mclist *ml, **mlp; 3158 3159 rtnl_lock(); 3160 3161 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3162 if (ml->ifindex == mreq->mr_ifindex && 3163 ml->type == mreq->mr_type && 3164 ml->alen == mreq->mr_alen && 3165 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3166 if (--ml->count == 0) { 3167 struct net_device *dev; 3168 *mlp = ml->next; 3169 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3170 if (dev) 3171 packet_dev_mc(dev, ml, -1); 3172 kfree(ml); 3173 } 3174 rtnl_unlock(); 3175 return 0; 3176 } 3177 } 3178 rtnl_unlock(); 3179 return -EADDRNOTAVAIL; 3180 } 3181 3182 static void packet_flush_mclist(struct sock *sk) 3183 { 3184 struct packet_sock *po = pkt_sk(sk); 3185 struct packet_mclist *ml; 3186 3187 if (!po->mclist) 3188 return; 3189 3190 rtnl_lock(); 3191 while ((ml = po->mclist) != NULL) { 3192 struct net_device *dev; 3193 3194 po->mclist = ml->next; 3195 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3196 if (dev != NULL) 3197 packet_dev_mc(dev, ml, -1); 3198 kfree(ml); 3199 } 3200 rtnl_unlock(); 3201 } 3202 3203 static int 3204 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3205 { 3206 struct sock *sk = sock->sk; 3207 struct packet_sock *po = pkt_sk(sk); 3208 int ret; 3209 3210 if (level != SOL_PACKET) 3211 return -ENOPROTOOPT; 3212 3213 switch (optname) { 3214 case PACKET_ADD_MEMBERSHIP: 3215 case PACKET_DROP_MEMBERSHIP: 3216 { 3217 struct packet_mreq_max mreq; 3218 int len = optlen; 3219 memset(&mreq, 0, sizeof(mreq)); 3220 if (len < sizeof(struct packet_mreq)) 3221 return -EINVAL; 3222 if (len > sizeof(mreq)) 3223 len = sizeof(mreq); 3224 if (copy_from_user(&mreq, optval, len)) 3225 return -EFAULT; 3226 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3227 return -EINVAL; 3228 if (optname == PACKET_ADD_MEMBERSHIP) 3229 ret = packet_mc_add(sk, &mreq); 3230 else 3231 ret = packet_mc_drop(sk, &mreq); 3232 return ret; 3233 } 3234 3235 case PACKET_RX_RING: 3236 case PACKET_TX_RING: 3237 { 3238 union tpacket_req_u req_u; 3239 int len; 3240 3241 switch (po->tp_version) { 3242 case TPACKET_V1: 3243 case TPACKET_V2: 3244 len = sizeof(req_u.req); 3245 break; 3246 case TPACKET_V3: 3247 default: 3248 len = sizeof(req_u.req3); 3249 break; 3250 } 3251 if (optlen < len) 3252 return -EINVAL; 3253 if (pkt_sk(sk)->has_vnet_hdr) 3254 return -EINVAL; 3255 if (copy_from_user(&req_u.req, optval, len)) 3256 return -EFAULT; 3257 return packet_set_ring(sk, &req_u, 0, 3258 optname == PACKET_TX_RING); 3259 } 3260 case PACKET_COPY_THRESH: 3261 { 3262 int val; 3263 3264 if (optlen != sizeof(val)) 3265 return -EINVAL; 3266 if (copy_from_user(&val, optval, sizeof(val))) 3267 return -EFAULT; 3268 3269 pkt_sk(sk)->copy_thresh = val; 3270 return 0; 3271 } 3272 case PACKET_VERSION: 3273 { 3274 int val; 3275 3276 if (optlen != sizeof(val)) 3277 return -EINVAL; 3278 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3279 return -EBUSY; 3280 if (copy_from_user(&val, optval, sizeof(val))) 3281 return -EFAULT; 3282 switch (val) { 3283 case TPACKET_V1: 3284 case TPACKET_V2: 3285 case TPACKET_V3: 3286 po->tp_version = val; 3287 return 0; 3288 default: 3289 return -EINVAL; 3290 } 3291 } 3292 case PACKET_RESERVE: 3293 { 3294 unsigned int val; 3295 3296 if (optlen != sizeof(val)) 3297 return -EINVAL; 3298 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3299 return -EBUSY; 3300 if (copy_from_user(&val, optval, sizeof(val))) 3301 return -EFAULT; 3302 po->tp_reserve = val; 3303 return 0; 3304 } 3305 case PACKET_LOSS: 3306 { 3307 unsigned int val; 3308 3309 if (optlen != sizeof(val)) 3310 return -EINVAL; 3311 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3312 return -EBUSY; 3313 if (copy_from_user(&val, optval, sizeof(val))) 3314 return -EFAULT; 3315 po->tp_loss = !!val; 3316 return 0; 3317 } 3318 case PACKET_AUXDATA: 3319 { 3320 int val; 3321 3322 if (optlen < sizeof(val)) 3323 return -EINVAL; 3324 if (copy_from_user(&val, optval, sizeof(val))) 3325 return -EFAULT; 3326 3327 po->auxdata = !!val; 3328 return 0; 3329 } 3330 case PACKET_ORIGDEV: 3331 { 3332 int val; 3333 3334 if (optlen < sizeof(val)) 3335 return -EINVAL; 3336 if (copy_from_user(&val, optval, sizeof(val))) 3337 return -EFAULT; 3338 3339 po->origdev = !!val; 3340 return 0; 3341 } 3342 case PACKET_VNET_HDR: 3343 { 3344 int val; 3345 3346 if (sock->type != SOCK_RAW) 3347 return -EINVAL; 3348 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3349 return -EBUSY; 3350 if (optlen < sizeof(val)) 3351 return -EINVAL; 3352 if (copy_from_user(&val, optval, sizeof(val))) 3353 return -EFAULT; 3354 3355 po->has_vnet_hdr = !!val; 3356 return 0; 3357 } 3358 case PACKET_TIMESTAMP: 3359 { 3360 int val; 3361 3362 if (optlen != sizeof(val)) 3363 return -EINVAL; 3364 if (copy_from_user(&val, optval, sizeof(val))) 3365 return -EFAULT; 3366 3367 po->tp_tstamp = val; 3368 return 0; 3369 } 3370 case PACKET_FANOUT: 3371 { 3372 int val; 3373 3374 if (optlen != sizeof(val)) 3375 return -EINVAL; 3376 if (copy_from_user(&val, optval, sizeof(val))) 3377 return -EFAULT; 3378 3379 return fanout_add(sk, val & 0xffff, val >> 16); 3380 } 3381 case PACKET_TX_HAS_OFF: 3382 { 3383 unsigned int val; 3384 3385 if (optlen != sizeof(val)) 3386 return -EINVAL; 3387 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3388 return -EBUSY; 3389 if (copy_from_user(&val, optval, sizeof(val))) 3390 return -EFAULT; 3391 po->tp_tx_has_off = !!val; 3392 return 0; 3393 } 3394 case PACKET_QDISC_BYPASS: 3395 { 3396 int val; 3397 3398 if (optlen != sizeof(val)) 3399 return -EINVAL; 3400 if (copy_from_user(&val, optval, sizeof(val))) 3401 return -EFAULT; 3402 3403 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3404 return 0; 3405 } 3406 default: 3407 return -ENOPROTOOPT; 3408 } 3409 } 3410 3411 static int packet_getsockopt(struct socket *sock, int level, int optname, 3412 char __user *optval, int __user *optlen) 3413 { 3414 int len; 3415 int val, lv = sizeof(val); 3416 struct sock *sk = sock->sk; 3417 struct packet_sock *po = pkt_sk(sk); 3418 void *data = &val; 3419 union tpacket_stats_u st; 3420 3421 if (level != SOL_PACKET) 3422 return -ENOPROTOOPT; 3423 3424 if (get_user(len, optlen)) 3425 return -EFAULT; 3426 3427 if (len < 0) 3428 return -EINVAL; 3429 3430 switch (optname) { 3431 case PACKET_STATISTICS: 3432 spin_lock_bh(&sk->sk_receive_queue.lock); 3433 memcpy(&st, &po->stats, sizeof(st)); 3434 memset(&po->stats, 0, sizeof(po->stats)); 3435 spin_unlock_bh(&sk->sk_receive_queue.lock); 3436 3437 if (po->tp_version == TPACKET_V3) { 3438 lv = sizeof(struct tpacket_stats_v3); 3439 st.stats3.tp_packets += st.stats3.tp_drops; 3440 data = &st.stats3; 3441 } else { 3442 lv = sizeof(struct tpacket_stats); 3443 st.stats1.tp_packets += st.stats1.tp_drops; 3444 data = &st.stats1; 3445 } 3446 3447 break; 3448 case PACKET_AUXDATA: 3449 val = po->auxdata; 3450 break; 3451 case PACKET_ORIGDEV: 3452 val = po->origdev; 3453 break; 3454 case PACKET_VNET_HDR: 3455 val = po->has_vnet_hdr; 3456 break; 3457 case PACKET_VERSION: 3458 val = po->tp_version; 3459 break; 3460 case PACKET_HDRLEN: 3461 if (len > sizeof(int)) 3462 len = sizeof(int); 3463 if (copy_from_user(&val, optval, len)) 3464 return -EFAULT; 3465 switch (val) { 3466 case TPACKET_V1: 3467 val = sizeof(struct tpacket_hdr); 3468 break; 3469 case TPACKET_V2: 3470 val = sizeof(struct tpacket2_hdr); 3471 break; 3472 case TPACKET_V3: 3473 val = sizeof(struct tpacket3_hdr); 3474 break; 3475 default: 3476 return -EINVAL; 3477 } 3478 break; 3479 case PACKET_RESERVE: 3480 val = po->tp_reserve; 3481 break; 3482 case PACKET_LOSS: 3483 val = po->tp_loss; 3484 break; 3485 case PACKET_TIMESTAMP: 3486 val = po->tp_tstamp; 3487 break; 3488 case PACKET_FANOUT: 3489 val = (po->fanout ? 3490 ((u32)po->fanout->id | 3491 ((u32)po->fanout->type << 16) | 3492 ((u32)po->fanout->flags << 24)) : 3493 0); 3494 break; 3495 case PACKET_TX_HAS_OFF: 3496 val = po->tp_tx_has_off; 3497 break; 3498 case PACKET_QDISC_BYPASS: 3499 val = packet_use_direct_xmit(po); 3500 break; 3501 default: 3502 return -ENOPROTOOPT; 3503 } 3504 3505 if (len > lv) 3506 len = lv; 3507 if (put_user(len, optlen)) 3508 return -EFAULT; 3509 if (copy_to_user(optval, data, len)) 3510 return -EFAULT; 3511 return 0; 3512 } 3513 3514 3515 static int packet_notifier(struct notifier_block *this, 3516 unsigned long msg, void *ptr) 3517 { 3518 struct sock *sk; 3519 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3520 struct net *net = dev_net(dev); 3521 3522 rcu_read_lock(); 3523 sk_for_each_rcu(sk, &net->packet.sklist) { 3524 struct packet_sock *po = pkt_sk(sk); 3525 3526 switch (msg) { 3527 case NETDEV_UNREGISTER: 3528 if (po->mclist) 3529 packet_dev_mclist(dev, po->mclist, -1); 3530 /* fallthrough */ 3531 3532 case NETDEV_DOWN: 3533 if (dev->ifindex == po->ifindex) { 3534 spin_lock(&po->bind_lock); 3535 if (po->running) { 3536 __unregister_prot_hook(sk, false); 3537 sk->sk_err = ENETDOWN; 3538 if (!sock_flag(sk, SOCK_DEAD)) 3539 sk->sk_error_report(sk); 3540 } 3541 if (msg == NETDEV_UNREGISTER) { 3542 packet_cached_dev_reset(po); 3543 po->ifindex = -1; 3544 if (po->prot_hook.dev) 3545 dev_put(po->prot_hook.dev); 3546 po->prot_hook.dev = NULL; 3547 } 3548 spin_unlock(&po->bind_lock); 3549 } 3550 break; 3551 case NETDEV_UP: 3552 if (dev->ifindex == po->ifindex) { 3553 spin_lock(&po->bind_lock); 3554 if (po->num) 3555 register_prot_hook(sk); 3556 spin_unlock(&po->bind_lock); 3557 } 3558 break; 3559 } 3560 } 3561 rcu_read_unlock(); 3562 return NOTIFY_DONE; 3563 } 3564 3565 3566 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3567 unsigned long arg) 3568 { 3569 struct sock *sk = sock->sk; 3570 3571 switch (cmd) { 3572 case SIOCOUTQ: 3573 { 3574 int amount = sk_wmem_alloc_get(sk); 3575 3576 return put_user(amount, (int __user *)arg); 3577 } 3578 case SIOCINQ: 3579 { 3580 struct sk_buff *skb; 3581 int amount = 0; 3582 3583 spin_lock_bh(&sk->sk_receive_queue.lock); 3584 skb = skb_peek(&sk->sk_receive_queue); 3585 if (skb) 3586 amount = skb->len; 3587 spin_unlock_bh(&sk->sk_receive_queue.lock); 3588 return put_user(amount, (int __user *)arg); 3589 } 3590 case SIOCGSTAMP: 3591 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3592 case SIOCGSTAMPNS: 3593 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3594 3595 #ifdef CONFIG_INET 3596 case SIOCADDRT: 3597 case SIOCDELRT: 3598 case SIOCDARP: 3599 case SIOCGARP: 3600 case SIOCSARP: 3601 case SIOCGIFADDR: 3602 case SIOCSIFADDR: 3603 case SIOCGIFBRDADDR: 3604 case SIOCSIFBRDADDR: 3605 case SIOCGIFNETMASK: 3606 case SIOCSIFNETMASK: 3607 case SIOCGIFDSTADDR: 3608 case SIOCSIFDSTADDR: 3609 case SIOCSIFFLAGS: 3610 return inet_dgram_ops.ioctl(sock, cmd, arg); 3611 #endif 3612 3613 default: 3614 return -ENOIOCTLCMD; 3615 } 3616 return 0; 3617 } 3618 3619 static unsigned int packet_poll(struct file *file, struct socket *sock, 3620 poll_table *wait) 3621 { 3622 struct sock *sk = sock->sk; 3623 struct packet_sock *po = pkt_sk(sk); 3624 unsigned int mask = datagram_poll(file, sock, wait); 3625 3626 spin_lock_bh(&sk->sk_receive_queue.lock); 3627 if (po->rx_ring.pg_vec) { 3628 if (!packet_previous_rx_frame(po, &po->rx_ring, 3629 TP_STATUS_KERNEL)) 3630 mask |= POLLIN | POLLRDNORM; 3631 } 3632 spin_unlock_bh(&sk->sk_receive_queue.lock); 3633 spin_lock_bh(&sk->sk_write_queue.lock); 3634 if (po->tx_ring.pg_vec) { 3635 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3636 mask |= POLLOUT | POLLWRNORM; 3637 } 3638 spin_unlock_bh(&sk->sk_write_queue.lock); 3639 return mask; 3640 } 3641 3642 3643 /* Dirty? Well, I still did not learn better way to account 3644 * for user mmaps. 3645 */ 3646 3647 static void packet_mm_open(struct vm_area_struct *vma) 3648 { 3649 struct file *file = vma->vm_file; 3650 struct socket *sock = file->private_data; 3651 struct sock *sk = sock->sk; 3652 3653 if (sk) 3654 atomic_inc(&pkt_sk(sk)->mapped); 3655 } 3656 3657 static void packet_mm_close(struct vm_area_struct *vma) 3658 { 3659 struct file *file = vma->vm_file; 3660 struct socket *sock = file->private_data; 3661 struct sock *sk = sock->sk; 3662 3663 if (sk) 3664 atomic_dec(&pkt_sk(sk)->mapped); 3665 } 3666 3667 static const struct vm_operations_struct packet_mmap_ops = { 3668 .open = packet_mm_open, 3669 .close = packet_mm_close, 3670 }; 3671 3672 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3673 unsigned int len) 3674 { 3675 int i; 3676 3677 for (i = 0; i < len; i++) { 3678 if (likely(pg_vec[i].buffer)) { 3679 if (is_vmalloc_addr(pg_vec[i].buffer)) 3680 vfree(pg_vec[i].buffer); 3681 else 3682 free_pages((unsigned long)pg_vec[i].buffer, 3683 order); 3684 pg_vec[i].buffer = NULL; 3685 } 3686 } 3687 kfree(pg_vec); 3688 } 3689 3690 static char *alloc_one_pg_vec_page(unsigned long order) 3691 { 3692 char *buffer; 3693 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3694 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3695 3696 buffer = (char *) __get_free_pages(gfp_flags, order); 3697 if (buffer) 3698 return buffer; 3699 3700 /* __get_free_pages failed, fall back to vmalloc */ 3701 buffer = vzalloc((1 << order) * PAGE_SIZE); 3702 if (buffer) 3703 return buffer; 3704 3705 /* vmalloc failed, lets dig into swap here */ 3706 gfp_flags &= ~__GFP_NORETRY; 3707 buffer = (char *) __get_free_pages(gfp_flags, order); 3708 if (buffer) 3709 return buffer; 3710 3711 /* complete and utter failure */ 3712 return NULL; 3713 } 3714 3715 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3716 { 3717 unsigned int block_nr = req->tp_block_nr; 3718 struct pgv *pg_vec; 3719 int i; 3720 3721 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3722 if (unlikely(!pg_vec)) 3723 goto out; 3724 3725 for (i = 0; i < block_nr; i++) { 3726 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3727 if (unlikely(!pg_vec[i].buffer)) 3728 goto out_free_pgvec; 3729 } 3730 3731 out: 3732 return pg_vec; 3733 3734 out_free_pgvec: 3735 free_pg_vec(pg_vec, order, block_nr); 3736 pg_vec = NULL; 3737 goto out; 3738 } 3739 3740 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3741 int closing, int tx_ring) 3742 { 3743 struct pgv *pg_vec = NULL; 3744 struct packet_sock *po = pkt_sk(sk); 3745 int was_running, order = 0; 3746 struct packet_ring_buffer *rb; 3747 struct sk_buff_head *rb_queue; 3748 __be16 num; 3749 int err = -EINVAL; 3750 /* Added to avoid minimal code churn */ 3751 struct tpacket_req *req = &req_u->req; 3752 3753 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3754 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3755 WARN(1, "Tx-ring is not supported.\n"); 3756 goto out; 3757 } 3758 3759 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3760 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3761 3762 err = -EBUSY; 3763 if (!closing) { 3764 if (atomic_read(&po->mapped)) 3765 goto out; 3766 if (packet_read_pending(rb)) 3767 goto out; 3768 } 3769 3770 if (req->tp_block_nr) { 3771 /* Sanity tests and some calculations */ 3772 err = -EBUSY; 3773 if (unlikely(rb->pg_vec)) 3774 goto out; 3775 3776 switch (po->tp_version) { 3777 case TPACKET_V1: 3778 po->tp_hdrlen = TPACKET_HDRLEN; 3779 break; 3780 case TPACKET_V2: 3781 po->tp_hdrlen = TPACKET2_HDRLEN; 3782 break; 3783 case TPACKET_V3: 3784 po->tp_hdrlen = TPACKET3_HDRLEN; 3785 break; 3786 } 3787 3788 err = -EINVAL; 3789 if (unlikely((int)req->tp_block_size <= 0)) 3790 goto out; 3791 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3792 goto out; 3793 if (po->tp_version >= TPACKET_V3 && 3794 (int)(req->tp_block_size - 3795 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) 3796 goto out; 3797 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3798 po->tp_reserve)) 3799 goto out; 3800 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3801 goto out; 3802 3803 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3804 if (unlikely(rb->frames_per_block <= 0)) 3805 goto out; 3806 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3807 req->tp_frame_nr)) 3808 goto out; 3809 3810 err = -ENOMEM; 3811 order = get_order(req->tp_block_size); 3812 pg_vec = alloc_pg_vec(req, order); 3813 if (unlikely(!pg_vec)) 3814 goto out; 3815 switch (po->tp_version) { 3816 case TPACKET_V3: 3817 /* Transmit path is not supported. We checked 3818 * it above but just being paranoid 3819 */ 3820 if (!tx_ring) 3821 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3822 break; 3823 default: 3824 break; 3825 } 3826 } 3827 /* Done */ 3828 else { 3829 err = -EINVAL; 3830 if (unlikely(req->tp_frame_nr)) 3831 goto out; 3832 } 3833 3834 lock_sock(sk); 3835 3836 /* Detach socket from network */ 3837 spin_lock(&po->bind_lock); 3838 was_running = po->running; 3839 num = po->num; 3840 if (was_running) { 3841 po->num = 0; 3842 __unregister_prot_hook(sk, false); 3843 } 3844 spin_unlock(&po->bind_lock); 3845 3846 synchronize_net(); 3847 3848 err = -EBUSY; 3849 mutex_lock(&po->pg_vec_lock); 3850 if (closing || atomic_read(&po->mapped) == 0) { 3851 err = 0; 3852 spin_lock_bh(&rb_queue->lock); 3853 swap(rb->pg_vec, pg_vec); 3854 rb->frame_max = (req->tp_frame_nr - 1); 3855 rb->head = 0; 3856 rb->frame_size = req->tp_frame_size; 3857 spin_unlock_bh(&rb_queue->lock); 3858 3859 swap(rb->pg_vec_order, order); 3860 swap(rb->pg_vec_len, req->tp_block_nr); 3861 3862 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3863 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3864 tpacket_rcv : packet_rcv; 3865 skb_queue_purge(rb_queue); 3866 if (atomic_read(&po->mapped)) 3867 pr_err("packet_mmap: vma is busy: %d\n", 3868 atomic_read(&po->mapped)); 3869 } 3870 mutex_unlock(&po->pg_vec_lock); 3871 3872 spin_lock(&po->bind_lock); 3873 if (was_running) { 3874 po->num = num; 3875 register_prot_hook(sk); 3876 } 3877 spin_unlock(&po->bind_lock); 3878 if (closing && (po->tp_version > TPACKET_V2)) { 3879 /* Because we don't support block-based V3 on tx-ring */ 3880 if (!tx_ring) 3881 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3882 } 3883 release_sock(sk); 3884 3885 if (pg_vec) 3886 free_pg_vec(pg_vec, order, req->tp_block_nr); 3887 out: 3888 return err; 3889 } 3890 3891 static int packet_mmap(struct file *file, struct socket *sock, 3892 struct vm_area_struct *vma) 3893 { 3894 struct sock *sk = sock->sk; 3895 struct packet_sock *po = pkt_sk(sk); 3896 unsigned long size, expected_size; 3897 struct packet_ring_buffer *rb; 3898 unsigned long start; 3899 int err = -EINVAL; 3900 int i; 3901 3902 if (vma->vm_pgoff) 3903 return -EINVAL; 3904 3905 mutex_lock(&po->pg_vec_lock); 3906 3907 expected_size = 0; 3908 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3909 if (rb->pg_vec) { 3910 expected_size += rb->pg_vec_len 3911 * rb->pg_vec_pages 3912 * PAGE_SIZE; 3913 } 3914 } 3915 3916 if (expected_size == 0) 3917 goto out; 3918 3919 size = vma->vm_end - vma->vm_start; 3920 if (size != expected_size) 3921 goto out; 3922 3923 start = vma->vm_start; 3924 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3925 if (rb->pg_vec == NULL) 3926 continue; 3927 3928 for (i = 0; i < rb->pg_vec_len; i++) { 3929 struct page *page; 3930 void *kaddr = rb->pg_vec[i].buffer; 3931 int pg_num; 3932 3933 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3934 page = pgv_to_page(kaddr); 3935 err = vm_insert_page(vma, start, page); 3936 if (unlikely(err)) 3937 goto out; 3938 start += PAGE_SIZE; 3939 kaddr += PAGE_SIZE; 3940 } 3941 } 3942 } 3943 3944 atomic_inc(&po->mapped); 3945 vma->vm_ops = &packet_mmap_ops; 3946 err = 0; 3947 3948 out: 3949 mutex_unlock(&po->pg_vec_lock); 3950 return err; 3951 } 3952 3953 static const struct proto_ops packet_ops_spkt = { 3954 .family = PF_PACKET, 3955 .owner = THIS_MODULE, 3956 .release = packet_release, 3957 .bind = packet_bind_spkt, 3958 .connect = sock_no_connect, 3959 .socketpair = sock_no_socketpair, 3960 .accept = sock_no_accept, 3961 .getname = packet_getname_spkt, 3962 .poll = datagram_poll, 3963 .ioctl = packet_ioctl, 3964 .listen = sock_no_listen, 3965 .shutdown = sock_no_shutdown, 3966 .setsockopt = sock_no_setsockopt, 3967 .getsockopt = sock_no_getsockopt, 3968 .sendmsg = packet_sendmsg_spkt, 3969 .recvmsg = packet_recvmsg, 3970 .mmap = sock_no_mmap, 3971 .sendpage = sock_no_sendpage, 3972 }; 3973 3974 static const struct proto_ops packet_ops = { 3975 .family = PF_PACKET, 3976 .owner = THIS_MODULE, 3977 .release = packet_release, 3978 .bind = packet_bind, 3979 .connect = sock_no_connect, 3980 .socketpair = sock_no_socketpair, 3981 .accept = sock_no_accept, 3982 .getname = packet_getname, 3983 .poll = packet_poll, 3984 .ioctl = packet_ioctl, 3985 .listen = sock_no_listen, 3986 .shutdown = sock_no_shutdown, 3987 .setsockopt = packet_setsockopt, 3988 .getsockopt = packet_getsockopt, 3989 .sendmsg = packet_sendmsg, 3990 .recvmsg = packet_recvmsg, 3991 .mmap = packet_mmap, 3992 .sendpage = sock_no_sendpage, 3993 }; 3994 3995 static const struct net_proto_family packet_family_ops = { 3996 .family = PF_PACKET, 3997 .create = packet_create, 3998 .owner = THIS_MODULE, 3999 }; 4000 4001 static struct notifier_block packet_netdev_notifier = { 4002 .notifier_call = packet_notifier, 4003 }; 4004 4005 #ifdef CONFIG_PROC_FS 4006 4007 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4008 __acquires(RCU) 4009 { 4010 struct net *net = seq_file_net(seq); 4011 4012 rcu_read_lock(); 4013 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4014 } 4015 4016 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4017 { 4018 struct net *net = seq_file_net(seq); 4019 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4020 } 4021 4022 static void packet_seq_stop(struct seq_file *seq, void *v) 4023 __releases(RCU) 4024 { 4025 rcu_read_unlock(); 4026 } 4027 4028 static int packet_seq_show(struct seq_file *seq, void *v) 4029 { 4030 if (v == SEQ_START_TOKEN) 4031 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4032 else { 4033 struct sock *s = sk_entry(v); 4034 const struct packet_sock *po = pkt_sk(s); 4035 4036 seq_printf(seq, 4037 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4038 s, 4039 atomic_read(&s->sk_refcnt), 4040 s->sk_type, 4041 ntohs(po->num), 4042 po->ifindex, 4043 po->running, 4044 atomic_read(&s->sk_rmem_alloc), 4045 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4046 sock_i_ino(s)); 4047 } 4048 4049 return 0; 4050 } 4051 4052 static const struct seq_operations packet_seq_ops = { 4053 .start = packet_seq_start, 4054 .next = packet_seq_next, 4055 .stop = packet_seq_stop, 4056 .show = packet_seq_show, 4057 }; 4058 4059 static int packet_seq_open(struct inode *inode, struct file *file) 4060 { 4061 return seq_open_net(inode, file, &packet_seq_ops, 4062 sizeof(struct seq_net_private)); 4063 } 4064 4065 static const struct file_operations packet_seq_fops = { 4066 .owner = THIS_MODULE, 4067 .open = packet_seq_open, 4068 .read = seq_read, 4069 .llseek = seq_lseek, 4070 .release = seq_release_net, 4071 }; 4072 4073 #endif 4074 4075 static int __net_init packet_net_init(struct net *net) 4076 { 4077 mutex_init(&net->packet.sklist_lock); 4078 INIT_HLIST_HEAD(&net->packet.sklist); 4079 4080 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4081 return -ENOMEM; 4082 4083 return 0; 4084 } 4085 4086 static void __net_exit packet_net_exit(struct net *net) 4087 { 4088 remove_proc_entry("packet", net->proc_net); 4089 } 4090 4091 static struct pernet_operations packet_net_ops = { 4092 .init = packet_net_init, 4093 .exit = packet_net_exit, 4094 }; 4095 4096 4097 static void __exit packet_exit(void) 4098 { 4099 unregister_netdevice_notifier(&packet_netdev_notifier); 4100 unregister_pernet_subsys(&packet_net_ops); 4101 sock_unregister(PF_PACKET); 4102 proto_unregister(&packet_proto); 4103 } 4104 4105 static int __init packet_init(void) 4106 { 4107 int rc = proto_register(&packet_proto, 0); 4108 4109 if (rc != 0) 4110 goto out; 4111 4112 sock_register(&packet_family_ops); 4113 register_pernet_subsys(&packet_net_ops); 4114 register_netdevice_notifier(&packet_netdev_notifier); 4115 out: 4116 return rc; 4117 } 4118 4119 module_init(packet_init); 4120 module_exit(packet_exit); 4121 MODULE_LICENSE("GPL"); 4122 MODULE_ALIAS_NETPROTO(PF_PACKET); 4123