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