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