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/reciprocal_div.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 struct net_device *packet_cached_dev_get(struct packet_sock *po) 241 { 242 struct net_device *dev; 243 244 rcu_read_lock(); 245 dev = rcu_dereference(po->cached_dev); 246 if (likely(dev)) 247 dev_hold(dev); 248 rcu_read_unlock(); 249 250 return dev; 251 } 252 253 static void packet_cached_dev_assign(struct packet_sock *po, 254 struct net_device *dev) 255 { 256 rcu_assign_pointer(po->cached_dev, dev); 257 } 258 259 static void packet_cached_dev_reset(struct packet_sock *po) 260 { 261 RCU_INIT_POINTER(po->cached_dev, NULL); 262 } 263 264 /* register_prot_hook must be invoked with the po->bind_lock held, 265 * or from a context in which asynchronous accesses to the packet 266 * socket is not possible (packet_create()). 267 */ 268 static void register_prot_hook(struct sock *sk) 269 { 270 struct packet_sock *po = pkt_sk(sk); 271 272 if (!po->running) { 273 if (po->fanout) 274 __fanout_link(sk, po); 275 else 276 dev_add_pack(&po->prot_hook); 277 278 sock_hold(sk); 279 po->running = 1; 280 } 281 } 282 283 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 284 * held. If the sync parameter is true, we will temporarily drop 285 * the po->bind_lock and do a synchronize_net to make sure no 286 * asynchronous packet processing paths still refer to the elements 287 * of po->prot_hook. If the sync parameter is false, it is the 288 * callers responsibility to take care of this. 289 */ 290 static void __unregister_prot_hook(struct sock *sk, bool sync) 291 { 292 struct packet_sock *po = pkt_sk(sk); 293 294 po->running = 0; 295 296 if (po->fanout) 297 __fanout_unlink(sk, po); 298 else 299 __dev_remove_pack(&po->prot_hook); 300 301 __sock_put(sk); 302 303 if (sync) { 304 spin_unlock(&po->bind_lock); 305 synchronize_net(); 306 spin_lock(&po->bind_lock); 307 } 308 } 309 310 static void unregister_prot_hook(struct sock *sk, bool sync) 311 { 312 struct packet_sock *po = pkt_sk(sk); 313 314 if (po->running) 315 __unregister_prot_hook(sk, sync); 316 } 317 318 static inline __pure struct page *pgv_to_page(void *addr) 319 { 320 if (is_vmalloc_addr(addr)) 321 return vmalloc_to_page(addr); 322 return virt_to_page(addr); 323 } 324 325 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 326 { 327 union tpacket_uhdr h; 328 329 h.raw = frame; 330 switch (po->tp_version) { 331 case TPACKET_V1: 332 h.h1->tp_status = status; 333 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 334 break; 335 case TPACKET_V2: 336 h.h2->tp_status = status; 337 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 338 break; 339 case TPACKET_V3: 340 default: 341 WARN(1, "TPACKET version not supported.\n"); 342 BUG(); 343 } 344 345 smp_wmb(); 346 } 347 348 static int __packet_get_status(struct packet_sock *po, void *frame) 349 { 350 union tpacket_uhdr h; 351 352 smp_rmb(); 353 354 h.raw = frame; 355 switch (po->tp_version) { 356 case TPACKET_V1: 357 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 358 return h.h1->tp_status; 359 case TPACKET_V2: 360 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 361 return h.h2->tp_status; 362 case TPACKET_V3: 363 default: 364 WARN(1, "TPACKET version not supported.\n"); 365 BUG(); 366 return 0; 367 } 368 } 369 370 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 371 unsigned int flags) 372 { 373 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 374 375 if (shhwtstamps) { 376 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) && 377 ktime_to_timespec_cond(shhwtstamps->syststamp, ts)) 378 return TP_STATUS_TS_SYS_HARDWARE; 379 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 380 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 381 return TP_STATUS_TS_RAW_HARDWARE; 382 } 383 384 if (ktime_to_timespec_cond(skb->tstamp, ts)) 385 return TP_STATUS_TS_SOFTWARE; 386 387 return 0; 388 } 389 390 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 391 struct sk_buff *skb) 392 { 393 union tpacket_uhdr h; 394 struct timespec ts; 395 __u32 ts_status; 396 397 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 398 return 0; 399 400 h.raw = frame; 401 switch (po->tp_version) { 402 case TPACKET_V1: 403 h.h1->tp_sec = ts.tv_sec; 404 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 405 break; 406 case TPACKET_V2: 407 h.h2->tp_sec = ts.tv_sec; 408 h.h2->tp_nsec = ts.tv_nsec; 409 break; 410 case TPACKET_V3: 411 default: 412 WARN(1, "TPACKET version not supported.\n"); 413 BUG(); 414 } 415 416 /* one flush is safe, as both fields always lie on the same cacheline */ 417 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 418 smp_wmb(); 419 420 return ts_status; 421 } 422 423 static void *packet_lookup_frame(struct packet_sock *po, 424 struct packet_ring_buffer *rb, 425 unsigned int position, 426 int status) 427 { 428 unsigned int pg_vec_pos, frame_offset; 429 union tpacket_uhdr h; 430 431 pg_vec_pos = position / rb->frames_per_block; 432 frame_offset = position % rb->frames_per_block; 433 434 h.raw = rb->pg_vec[pg_vec_pos].buffer + 435 (frame_offset * rb->frame_size); 436 437 if (status != __packet_get_status(po, h.raw)) 438 return NULL; 439 440 return h.raw; 441 } 442 443 static void *packet_current_frame(struct packet_sock *po, 444 struct packet_ring_buffer *rb, 445 int status) 446 { 447 return packet_lookup_frame(po, rb, rb->head, status); 448 } 449 450 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 451 { 452 del_timer_sync(&pkc->retire_blk_timer); 453 } 454 455 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 456 int tx_ring, 457 struct sk_buff_head *rb_queue) 458 { 459 struct tpacket_kbdq_core *pkc; 460 461 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 462 463 spin_lock_bh(&rb_queue->lock); 464 pkc->delete_blk_timer = 1; 465 spin_unlock_bh(&rb_queue->lock); 466 467 prb_del_retire_blk_timer(pkc); 468 } 469 470 static void prb_init_blk_timer(struct packet_sock *po, 471 struct tpacket_kbdq_core *pkc, 472 void (*func) (unsigned long)) 473 { 474 init_timer(&pkc->retire_blk_timer); 475 pkc->retire_blk_timer.data = (long)po; 476 pkc->retire_blk_timer.function = func; 477 pkc->retire_blk_timer.expires = jiffies; 478 } 479 480 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 481 { 482 struct tpacket_kbdq_core *pkc; 483 484 if (tx_ring) 485 BUG(); 486 487 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 488 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 489 } 490 491 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 492 int blk_size_in_bytes) 493 { 494 struct net_device *dev; 495 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 496 struct ethtool_cmd ecmd; 497 int err; 498 u32 speed; 499 500 rtnl_lock(); 501 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 502 if (unlikely(!dev)) { 503 rtnl_unlock(); 504 return DEFAULT_PRB_RETIRE_TOV; 505 } 506 err = __ethtool_get_settings(dev, &ecmd); 507 speed = ethtool_cmd_speed(&ecmd); 508 rtnl_unlock(); 509 if (!err) { 510 /* 511 * If the link speed is so slow you don't really 512 * need to worry about perf anyways 513 */ 514 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 515 return DEFAULT_PRB_RETIRE_TOV; 516 } else { 517 msec = 1; 518 div = speed / 1000; 519 } 520 } 521 522 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 523 524 if (div) 525 mbits /= div; 526 527 tmo = mbits * msec; 528 529 if (div) 530 return tmo+1; 531 return tmo; 532 } 533 534 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 535 union tpacket_req_u *req_u) 536 { 537 p1->feature_req_word = req_u->req3.tp_feature_req_word; 538 } 539 540 static void init_prb_bdqc(struct packet_sock *po, 541 struct packet_ring_buffer *rb, 542 struct pgv *pg_vec, 543 union tpacket_req_u *req_u, int tx_ring) 544 { 545 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 546 struct tpacket_block_desc *pbd; 547 548 memset(p1, 0x0, sizeof(*p1)); 549 550 p1->knxt_seq_num = 1; 551 p1->pkbdq = pg_vec; 552 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 553 p1->pkblk_start = pg_vec[0].buffer; 554 p1->kblk_size = req_u->req3.tp_block_size; 555 p1->knum_blocks = req_u->req3.tp_block_nr; 556 p1->hdrlen = po->tp_hdrlen; 557 p1->version = po->tp_version; 558 p1->last_kactive_blk_num = 0; 559 po->stats.stats3.tp_freeze_q_cnt = 0; 560 if (req_u->req3.tp_retire_blk_tov) 561 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 562 else 563 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 564 req_u->req3.tp_block_size); 565 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 566 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 567 568 prb_init_ft_ops(p1, req_u); 569 prb_setup_retire_blk_timer(po, tx_ring); 570 prb_open_block(p1, pbd); 571 } 572 573 /* Do NOT update the last_blk_num first. 574 * Assumes sk_buff_head lock is held. 575 */ 576 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 577 { 578 mod_timer(&pkc->retire_blk_timer, 579 jiffies + pkc->tov_in_jiffies); 580 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 581 } 582 583 /* 584 * Timer logic: 585 * 1) We refresh the timer only when we open a block. 586 * By doing this we don't waste cycles refreshing the timer 587 * on packet-by-packet basis. 588 * 589 * With a 1MB block-size, on a 1Gbps line, it will take 590 * i) ~8 ms to fill a block + ii) memcpy etc. 591 * In this cut we are not accounting for the memcpy time. 592 * 593 * So, if the user sets the 'tmo' to 10ms then the timer 594 * will never fire while the block is still getting filled 595 * (which is what we want). However, the user could choose 596 * to close a block early and that's fine. 597 * 598 * But when the timer does fire, we check whether or not to refresh it. 599 * Since the tmo granularity is in msecs, it is not too expensive 600 * to refresh the timer, lets say every '8' msecs. 601 * Either the user can set the 'tmo' or we can derive it based on 602 * a) line-speed and b) block-size. 603 * prb_calc_retire_blk_tmo() calculates the tmo. 604 * 605 */ 606 static void prb_retire_rx_blk_timer_expired(unsigned long data) 607 { 608 struct packet_sock *po = (struct packet_sock *)data; 609 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 610 unsigned int frozen; 611 struct tpacket_block_desc *pbd; 612 613 spin_lock(&po->sk.sk_receive_queue.lock); 614 615 frozen = prb_queue_frozen(pkc); 616 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 617 618 if (unlikely(pkc->delete_blk_timer)) 619 goto out; 620 621 /* We only need to plug the race when the block is partially filled. 622 * tpacket_rcv: 623 * lock(); increment BLOCK_NUM_PKTS; unlock() 624 * copy_bits() is in progress ... 625 * timer fires on other cpu: 626 * we can't retire the current block because copy_bits 627 * is in progress. 628 * 629 */ 630 if (BLOCK_NUM_PKTS(pbd)) { 631 while (atomic_read(&pkc->blk_fill_in_prog)) { 632 /* Waiting for skb_copy_bits to finish... */ 633 cpu_relax(); 634 } 635 } 636 637 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 638 if (!frozen) { 639 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 640 if (!prb_dispatch_next_block(pkc, po)) 641 goto refresh_timer; 642 else 643 goto out; 644 } else { 645 /* Case 1. Queue was frozen because user-space was 646 * lagging behind. 647 */ 648 if (prb_curr_blk_in_use(pkc, pbd)) { 649 /* 650 * Ok, user-space is still behind. 651 * So just refresh the timer. 652 */ 653 goto refresh_timer; 654 } else { 655 /* Case 2. queue was frozen,user-space caught up, 656 * now the link went idle && the timer fired. 657 * We don't have a block to close.So we open this 658 * block and restart the timer. 659 * opening a block thaws the queue,restarts timer 660 * Thawing/timer-refresh is a side effect. 661 */ 662 prb_open_block(pkc, pbd); 663 goto out; 664 } 665 } 666 } 667 668 refresh_timer: 669 _prb_refresh_rx_retire_blk_timer(pkc); 670 671 out: 672 spin_unlock(&po->sk.sk_receive_queue.lock); 673 } 674 675 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 676 struct tpacket_block_desc *pbd1, __u32 status) 677 { 678 /* Flush everything minus the block header */ 679 680 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 681 u8 *start, *end; 682 683 start = (u8 *)pbd1; 684 685 /* Skip the block header(we know header WILL fit in 4K) */ 686 start += PAGE_SIZE; 687 688 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 689 for (; start < end; start += PAGE_SIZE) 690 flush_dcache_page(pgv_to_page(start)); 691 692 smp_wmb(); 693 #endif 694 695 /* Now update the block status. */ 696 697 BLOCK_STATUS(pbd1) = status; 698 699 /* Flush the block header */ 700 701 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 702 start = (u8 *)pbd1; 703 flush_dcache_page(pgv_to_page(start)); 704 705 smp_wmb(); 706 #endif 707 } 708 709 /* 710 * Side effect: 711 * 712 * 1) flush the block 713 * 2) Increment active_blk_num 714 * 715 * Note:We DONT refresh the timer on purpose. 716 * Because almost always the next block will be opened. 717 */ 718 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 719 struct tpacket_block_desc *pbd1, 720 struct packet_sock *po, unsigned int stat) 721 { 722 __u32 status = TP_STATUS_USER | stat; 723 724 struct tpacket3_hdr *last_pkt; 725 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 726 727 if (po->stats.stats3.tp_drops) 728 status |= TP_STATUS_LOSING; 729 730 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 731 last_pkt->tp_next_offset = 0; 732 733 /* Get the ts of the last pkt */ 734 if (BLOCK_NUM_PKTS(pbd1)) { 735 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 736 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 737 } else { 738 /* Ok, we tmo'd - so get the current time */ 739 struct timespec ts; 740 getnstimeofday(&ts); 741 h1->ts_last_pkt.ts_sec = ts.tv_sec; 742 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 743 } 744 745 smp_wmb(); 746 747 /* Flush the block */ 748 prb_flush_block(pkc1, pbd1, status); 749 750 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 751 } 752 753 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 754 { 755 pkc->reset_pending_on_curr_blk = 0; 756 } 757 758 /* 759 * Side effect of opening a block: 760 * 761 * 1) prb_queue is thawed. 762 * 2) retire_blk_timer is refreshed. 763 * 764 */ 765 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 766 struct tpacket_block_desc *pbd1) 767 { 768 struct timespec ts; 769 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 770 771 smp_rmb(); 772 773 /* We could have just memset this but we will lose the 774 * flexibility of making the priv area sticky 775 */ 776 777 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 778 BLOCK_NUM_PKTS(pbd1) = 0; 779 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 780 781 getnstimeofday(&ts); 782 783 h1->ts_first_pkt.ts_sec = ts.tv_sec; 784 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 785 786 pkc1->pkblk_start = (char *)pbd1; 787 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 788 789 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 790 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 791 792 pbd1->version = pkc1->version; 793 pkc1->prev = pkc1->nxt_offset; 794 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 795 796 prb_thaw_queue(pkc1); 797 _prb_refresh_rx_retire_blk_timer(pkc1); 798 799 smp_wmb(); 800 } 801 802 /* 803 * Queue freeze logic: 804 * 1) Assume tp_block_nr = 8 blocks. 805 * 2) At time 't0', user opens Rx ring. 806 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 807 * 4) user-space is either sleeping or processing block '0'. 808 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 809 * it will close block-7,loop around and try to fill block '0'. 810 * call-flow: 811 * __packet_lookup_frame_in_block 812 * prb_retire_current_block() 813 * prb_dispatch_next_block() 814 * |->(BLOCK_STATUS == USER) evaluates to true 815 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 816 * 6) Now there are two cases: 817 * 6.1) Link goes idle right after the queue is frozen. 818 * But remember, the last open_block() refreshed the timer. 819 * When this timer expires,it will refresh itself so that we can 820 * re-open block-0 in near future. 821 * 6.2) Link is busy and keeps on receiving packets. This is a simple 822 * case and __packet_lookup_frame_in_block will check if block-0 823 * is free and can now be re-used. 824 */ 825 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 826 struct packet_sock *po) 827 { 828 pkc->reset_pending_on_curr_blk = 1; 829 po->stats.stats3.tp_freeze_q_cnt++; 830 } 831 832 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 833 834 /* 835 * If the next block is free then we will dispatch it 836 * and return a good offset. 837 * Else, we will freeze the queue. 838 * So, caller must check the return value. 839 */ 840 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 841 struct packet_sock *po) 842 { 843 struct tpacket_block_desc *pbd; 844 845 smp_rmb(); 846 847 /* 1. Get current block num */ 848 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 849 850 /* 2. If this block is currently in_use then freeze the queue */ 851 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 852 prb_freeze_queue(pkc, po); 853 return NULL; 854 } 855 856 /* 857 * 3. 858 * open this block and return the offset where the first packet 859 * needs to get stored. 860 */ 861 prb_open_block(pkc, pbd); 862 return (void *)pkc->nxt_offset; 863 } 864 865 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 866 struct packet_sock *po, unsigned int status) 867 { 868 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 869 870 /* retire/close the current block */ 871 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 872 /* 873 * Plug the case where copy_bits() is in progress on 874 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 875 * have space to copy the pkt in the current block and 876 * called prb_retire_current_block() 877 * 878 * We don't need to worry about the TMO case because 879 * the timer-handler already handled this case. 880 */ 881 if (!(status & TP_STATUS_BLK_TMO)) { 882 while (atomic_read(&pkc->blk_fill_in_prog)) { 883 /* Waiting for skb_copy_bits to finish... */ 884 cpu_relax(); 885 } 886 } 887 prb_close_block(pkc, pbd, po, status); 888 return; 889 } 890 } 891 892 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 893 struct tpacket_block_desc *pbd) 894 { 895 return TP_STATUS_USER & BLOCK_STATUS(pbd); 896 } 897 898 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 899 { 900 return pkc->reset_pending_on_curr_blk; 901 } 902 903 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 904 { 905 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 906 atomic_dec(&pkc->blk_fill_in_prog); 907 } 908 909 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 910 struct tpacket3_hdr *ppd) 911 { 912 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 913 } 914 915 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 916 struct tpacket3_hdr *ppd) 917 { 918 ppd->hv1.tp_rxhash = 0; 919 } 920 921 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 922 struct tpacket3_hdr *ppd) 923 { 924 if (vlan_tx_tag_present(pkc->skb)) { 925 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 926 ppd->tp_status = TP_STATUS_VLAN_VALID; 927 } else { 928 ppd->hv1.tp_vlan_tci = 0; 929 ppd->tp_status = TP_STATUS_AVAILABLE; 930 } 931 } 932 933 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 934 struct tpacket3_hdr *ppd) 935 { 936 prb_fill_vlan_info(pkc, ppd); 937 938 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 939 prb_fill_rxhash(pkc, ppd); 940 else 941 prb_clear_rxhash(pkc, ppd); 942 } 943 944 static void prb_fill_curr_block(char *curr, 945 struct tpacket_kbdq_core *pkc, 946 struct tpacket_block_desc *pbd, 947 unsigned int len) 948 { 949 struct tpacket3_hdr *ppd; 950 951 ppd = (struct tpacket3_hdr *)curr; 952 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 953 pkc->prev = curr; 954 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 955 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 956 BLOCK_NUM_PKTS(pbd) += 1; 957 atomic_inc(&pkc->blk_fill_in_prog); 958 prb_run_all_ft_ops(pkc, ppd); 959 } 960 961 /* Assumes caller has the sk->rx_queue.lock */ 962 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 963 struct sk_buff *skb, 964 int status, 965 unsigned int len 966 ) 967 { 968 struct tpacket_kbdq_core *pkc; 969 struct tpacket_block_desc *pbd; 970 char *curr, *end; 971 972 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 973 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 974 975 /* Queue is frozen when user space is lagging behind */ 976 if (prb_queue_frozen(pkc)) { 977 /* 978 * Check if that last block which caused the queue to freeze, 979 * is still in_use by user-space. 980 */ 981 if (prb_curr_blk_in_use(pkc, pbd)) { 982 /* Can't record this packet */ 983 return NULL; 984 } else { 985 /* 986 * Ok, the block was released by user-space. 987 * Now let's open that block. 988 * opening a block also thaws the queue. 989 * Thawing is a side effect. 990 */ 991 prb_open_block(pkc, pbd); 992 } 993 } 994 995 smp_mb(); 996 curr = pkc->nxt_offset; 997 pkc->skb = skb; 998 end = (char *)pbd + pkc->kblk_size; 999 1000 /* first try the current block */ 1001 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1002 prb_fill_curr_block(curr, pkc, pbd, len); 1003 return (void *)curr; 1004 } 1005 1006 /* Ok, close the current block */ 1007 prb_retire_current_block(pkc, po, 0); 1008 1009 /* Now, try to dispatch the next block */ 1010 curr = (char *)prb_dispatch_next_block(pkc, po); 1011 if (curr) { 1012 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1013 prb_fill_curr_block(curr, pkc, pbd, len); 1014 return (void *)curr; 1015 } 1016 1017 /* 1018 * No free blocks are available.user_space hasn't caught up yet. 1019 * Queue was just frozen and now this packet will get dropped. 1020 */ 1021 return NULL; 1022 } 1023 1024 static void *packet_current_rx_frame(struct packet_sock *po, 1025 struct sk_buff *skb, 1026 int status, unsigned int len) 1027 { 1028 char *curr = NULL; 1029 switch (po->tp_version) { 1030 case TPACKET_V1: 1031 case TPACKET_V2: 1032 curr = packet_lookup_frame(po, &po->rx_ring, 1033 po->rx_ring.head, status); 1034 return curr; 1035 case TPACKET_V3: 1036 return __packet_lookup_frame_in_block(po, skb, status, len); 1037 default: 1038 WARN(1, "TPACKET version not supported\n"); 1039 BUG(); 1040 return NULL; 1041 } 1042 } 1043 1044 static void *prb_lookup_block(struct packet_sock *po, 1045 struct packet_ring_buffer *rb, 1046 unsigned int idx, 1047 int status) 1048 { 1049 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1050 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1051 1052 if (status != BLOCK_STATUS(pbd)) 1053 return NULL; 1054 return pbd; 1055 } 1056 1057 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1058 { 1059 unsigned int prev; 1060 if (rb->prb_bdqc.kactive_blk_num) 1061 prev = rb->prb_bdqc.kactive_blk_num-1; 1062 else 1063 prev = rb->prb_bdqc.knum_blocks-1; 1064 return prev; 1065 } 1066 1067 /* Assumes caller has held the rx_queue.lock */ 1068 static void *__prb_previous_block(struct packet_sock *po, 1069 struct packet_ring_buffer *rb, 1070 int status) 1071 { 1072 unsigned int previous = prb_previous_blk_num(rb); 1073 return prb_lookup_block(po, rb, previous, status); 1074 } 1075 1076 static void *packet_previous_rx_frame(struct packet_sock *po, 1077 struct packet_ring_buffer *rb, 1078 int status) 1079 { 1080 if (po->tp_version <= TPACKET_V2) 1081 return packet_previous_frame(po, rb, status); 1082 1083 return __prb_previous_block(po, rb, status); 1084 } 1085 1086 static void packet_increment_rx_head(struct packet_sock *po, 1087 struct packet_ring_buffer *rb) 1088 { 1089 switch (po->tp_version) { 1090 case TPACKET_V1: 1091 case TPACKET_V2: 1092 return packet_increment_head(rb); 1093 case TPACKET_V3: 1094 default: 1095 WARN(1, "TPACKET version not supported.\n"); 1096 BUG(); 1097 return; 1098 } 1099 } 1100 1101 static void *packet_previous_frame(struct packet_sock *po, 1102 struct packet_ring_buffer *rb, 1103 int status) 1104 { 1105 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1106 return packet_lookup_frame(po, rb, previous, status); 1107 } 1108 1109 static void packet_increment_head(struct packet_ring_buffer *buff) 1110 { 1111 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1112 } 1113 1114 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1115 { 1116 struct sock *sk = &po->sk; 1117 bool has_room; 1118 1119 if (po->prot_hook.func != tpacket_rcv) 1120 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize) 1121 <= sk->sk_rcvbuf; 1122 1123 spin_lock(&sk->sk_receive_queue.lock); 1124 if (po->tp_version == TPACKET_V3) 1125 has_room = prb_lookup_block(po, &po->rx_ring, 1126 po->rx_ring.prb_bdqc.kactive_blk_num, 1127 TP_STATUS_KERNEL); 1128 else 1129 has_room = packet_lookup_frame(po, &po->rx_ring, 1130 po->rx_ring.head, 1131 TP_STATUS_KERNEL); 1132 spin_unlock(&sk->sk_receive_queue.lock); 1133 1134 return has_room; 1135 } 1136 1137 static void packet_sock_destruct(struct sock *sk) 1138 { 1139 skb_queue_purge(&sk->sk_error_queue); 1140 1141 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1142 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1143 1144 if (!sock_flag(sk, SOCK_DEAD)) { 1145 pr_err("Attempt to release alive packet socket: %p\n", sk); 1146 return; 1147 } 1148 1149 sk_refcnt_debug_dec(sk); 1150 } 1151 1152 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1153 { 1154 int x = atomic_read(&f->rr_cur) + 1; 1155 1156 if (x >= num) 1157 x = 0; 1158 1159 return x; 1160 } 1161 1162 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1163 struct sk_buff *skb, 1164 unsigned int num) 1165 { 1166 return reciprocal_divide(skb->rxhash, num); 1167 } 1168 1169 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1170 struct sk_buff *skb, 1171 unsigned int num) 1172 { 1173 int cur, old; 1174 1175 cur = atomic_read(&f->rr_cur); 1176 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1177 fanout_rr_next(f, num))) != cur) 1178 cur = old; 1179 return cur; 1180 } 1181 1182 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1183 struct sk_buff *skb, 1184 unsigned int num) 1185 { 1186 return smp_processor_id() % num; 1187 } 1188 1189 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1190 struct sk_buff *skb, 1191 unsigned int num) 1192 { 1193 return reciprocal_divide(prandom_u32(), num); 1194 } 1195 1196 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1197 struct sk_buff *skb, 1198 unsigned int idx, unsigned int skip, 1199 unsigned int num) 1200 { 1201 unsigned int i, j; 1202 1203 i = j = min_t(int, f->next[idx], num - 1); 1204 do { 1205 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) { 1206 if (i != j) 1207 f->next[idx] = i; 1208 return i; 1209 } 1210 if (++i == num) 1211 i = 0; 1212 } while (i != j); 1213 1214 return idx; 1215 } 1216 1217 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1218 { 1219 return f->flags & (flag >> 8); 1220 } 1221 1222 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1223 struct packet_type *pt, struct net_device *orig_dev) 1224 { 1225 struct packet_fanout *f = pt->af_packet_priv; 1226 unsigned int num = f->num_members; 1227 struct packet_sock *po; 1228 unsigned int idx; 1229 1230 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1231 !num) { 1232 kfree_skb(skb); 1233 return 0; 1234 } 1235 1236 switch (f->type) { 1237 case PACKET_FANOUT_HASH: 1238 default: 1239 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1240 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1241 if (!skb) 1242 return 0; 1243 } 1244 skb_get_rxhash(skb); 1245 idx = fanout_demux_hash(f, skb, num); 1246 break; 1247 case PACKET_FANOUT_LB: 1248 idx = fanout_demux_lb(f, skb, num); 1249 break; 1250 case PACKET_FANOUT_CPU: 1251 idx = fanout_demux_cpu(f, skb, num); 1252 break; 1253 case PACKET_FANOUT_RND: 1254 idx = fanout_demux_rnd(f, skb, num); 1255 break; 1256 case PACKET_FANOUT_ROLLOVER: 1257 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num); 1258 break; 1259 } 1260 1261 po = pkt_sk(f->arr[idx]); 1262 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) && 1263 unlikely(!packet_rcv_has_room(po, skb))) { 1264 idx = fanout_demux_rollover(f, skb, idx, idx, num); 1265 po = pkt_sk(f->arr[idx]); 1266 } 1267 1268 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1269 } 1270 1271 DEFINE_MUTEX(fanout_mutex); 1272 EXPORT_SYMBOL_GPL(fanout_mutex); 1273 static LIST_HEAD(fanout_list); 1274 1275 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1276 { 1277 struct packet_fanout *f = po->fanout; 1278 1279 spin_lock(&f->lock); 1280 f->arr[f->num_members] = sk; 1281 smp_wmb(); 1282 f->num_members++; 1283 spin_unlock(&f->lock); 1284 } 1285 1286 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1287 { 1288 struct packet_fanout *f = po->fanout; 1289 int i; 1290 1291 spin_lock(&f->lock); 1292 for (i = 0; i < f->num_members; i++) { 1293 if (f->arr[i] == sk) 1294 break; 1295 } 1296 BUG_ON(i >= f->num_members); 1297 f->arr[i] = f->arr[f->num_members - 1]; 1298 f->num_members--; 1299 spin_unlock(&f->lock); 1300 } 1301 1302 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk) 1303 { 1304 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) 1305 return true; 1306 1307 return false; 1308 } 1309 1310 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1311 { 1312 struct packet_sock *po = pkt_sk(sk); 1313 struct packet_fanout *f, *match; 1314 u8 type = type_flags & 0xff; 1315 u8 flags = type_flags >> 8; 1316 int err; 1317 1318 switch (type) { 1319 case PACKET_FANOUT_ROLLOVER: 1320 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1321 return -EINVAL; 1322 case PACKET_FANOUT_HASH: 1323 case PACKET_FANOUT_LB: 1324 case PACKET_FANOUT_CPU: 1325 case PACKET_FANOUT_RND: 1326 break; 1327 default: 1328 return -EINVAL; 1329 } 1330 1331 if (!po->running) 1332 return -EINVAL; 1333 1334 if (po->fanout) 1335 return -EALREADY; 1336 1337 mutex_lock(&fanout_mutex); 1338 match = NULL; 1339 list_for_each_entry(f, &fanout_list, list) { 1340 if (f->id == id && 1341 read_pnet(&f->net) == sock_net(sk)) { 1342 match = f; 1343 break; 1344 } 1345 } 1346 err = -EINVAL; 1347 if (match && match->flags != flags) 1348 goto out; 1349 if (!match) { 1350 err = -ENOMEM; 1351 match = kzalloc(sizeof(*match), GFP_KERNEL); 1352 if (!match) 1353 goto out; 1354 write_pnet(&match->net, sock_net(sk)); 1355 match->id = id; 1356 match->type = type; 1357 match->flags = flags; 1358 atomic_set(&match->rr_cur, 0); 1359 INIT_LIST_HEAD(&match->list); 1360 spin_lock_init(&match->lock); 1361 atomic_set(&match->sk_ref, 0); 1362 match->prot_hook.type = po->prot_hook.type; 1363 match->prot_hook.dev = po->prot_hook.dev; 1364 match->prot_hook.func = packet_rcv_fanout; 1365 match->prot_hook.af_packet_priv = match; 1366 match->prot_hook.id_match = match_fanout_group; 1367 dev_add_pack(&match->prot_hook); 1368 list_add(&match->list, &fanout_list); 1369 } 1370 err = -EINVAL; 1371 if (match->type == type && 1372 match->prot_hook.type == po->prot_hook.type && 1373 match->prot_hook.dev == po->prot_hook.dev) { 1374 err = -ENOSPC; 1375 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1376 __dev_remove_pack(&po->prot_hook); 1377 po->fanout = match; 1378 atomic_inc(&match->sk_ref); 1379 __fanout_link(sk, po); 1380 err = 0; 1381 } 1382 } 1383 out: 1384 mutex_unlock(&fanout_mutex); 1385 return err; 1386 } 1387 1388 static void fanout_release(struct sock *sk) 1389 { 1390 struct packet_sock *po = pkt_sk(sk); 1391 struct packet_fanout *f; 1392 1393 f = po->fanout; 1394 if (!f) 1395 return; 1396 1397 mutex_lock(&fanout_mutex); 1398 po->fanout = NULL; 1399 1400 if (atomic_dec_and_test(&f->sk_ref)) { 1401 list_del(&f->list); 1402 dev_remove_pack(&f->prot_hook); 1403 kfree(f); 1404 } 1405 mutex_unlock(&fanout_mutex); 1406 } 1407 1408 static const struct proto_ops packet_ops; 1409 1410 static const struct proto_ops packet_ops_spkt; 1411 1412 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1413 struct packet_type *pt, struct net_device *orig_dev) 1414 { 1415 struct sock *sk; 1416 struct sockaddr_pkt *spkt; 1417 1418 /* 1419 * When we registered the protocol we saved the socket in the data 1420 * field for just this event. 1421 */ 1422 1423 sk = pt->af_packet_priv; 1424 1425 /* 1426 * Yank back the headers [hope the device set this 1427 * right or kerboom...] 1428 * 1429 * Incoming packets have ll header pulled, 1430 * push it back. 1431 * 1432 * For outgoing ones skb->data == skb_mac_header(skb) 1433 * so that this procedure is noop. 1434 */ 1435 1436 if (skb->pkt_type == PACKET_LOOPBACK) 1437 goto out; 1438 1439 if (!net_eq(dev_net(dev), sock_net(sk))) 1440 goto out; 1441 1442 skb = skb_share_check(skb, GFP_ATOMIC); 1443 if (skb == NULL) 1444 goto oom; 1445 1446 /* drop any routing info */ 1447 skb_dst_drop(skb); 1448 1449 /* drop conntrack reference */ 1450 nf_reset(skb); 1451 1452 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1453 1454 skb_push(skb, skb->data - skb_mac_header(skb)); 1455 1456 /* 1457 * The SOCK_PACKET socket receives _all_ frames. 1458 */ 1459 1460 spkt->spkt_family = dev->type; 1461 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1462 spkt->spkt_protocol = skb->protocol; 1463 1464 /* 1465 * Charge the memory to the socket. This is done specifically 1466 * to prevent sockets using all the memory up. 1467 */ 1468 1469 if (sock_queue_rcv_skb(sk, skb) == 0) 1470 return 0; 1471 1472 out: 1473 kfree_skb(skb); 1474 oom: 1475 return 0; 1476 } 1477 1478 1479 /* 1480 * Output a raw packet to a device layer. This bypasses all the other 1481 * protocol layers and you must therefore supply it with a complete frame 1482 */ 1483 1484 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1485 struct msghdr *msg, size_t len) 1486 { 1487 struct sock *sk = sock->sk; 1488 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1489 struct sk_buff *skb = NULL; 1490 struct net_device *dev; 1491 __be16 proto = 0; 1492 int err; 1493 int extra_len = 0; 1494 1495 /* 1496 * Get and verify the address. 1497 */ 1498 1499 if (saddr) { 1500 if (msg->msg_namelen < sizeof(struct sockaddr)) 1501 return -EINVAL; 1502 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1503 proto = saddr->spkt_protocol; 1504 } else 1505 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1506 1507 /* 1508 * Find the device first to size check it 1509 */ 1510 1511 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1512 retry: 1513 rcu_read_lock(); 1514 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1515 err = -ENODEV; 1516 if (dev == NULL) 1517 goto out_unlock; 1518 1519 err = -ENETDOWN; 1520 if (!(dev->flags & IFF_UP)) 1521 goto out_unlock; 1522 1523 /* 1524 * You may not queue a frame bigger than the mtu. This is the lowest level 1525 * raw protocol and you must do your own fragmentation at this level. 1526 */ 1527 1528 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1529 if (!netif_supports_nofcs(dev)) { 1530 err = -EPROTONOSUPPORT; 1531 goto out_unlock; 1532 } 1533 extra_len = 4; /* We're doing our own CRC */ 1534 } 1535 1536 err = -EMSGSIZE; 1537 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1538 goto out_unlock; 1539 1540 if (!skb) { 1541 size_t reserved = LL_RESERVED_SPACE(dev); 1542 int tlen = dev->needed_tailroom; 1543 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1544 1545 rcu_read_unlock(); 1546 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1547 if (skb == NULL) 1548 return -ENOBUFS; 1549 /* FIXME: Save some space for broken drivers that write a hard 1550 * header at transmission time by themselves. PPP is the notable 1551 * one here. This should really be fixed at the driver level. 1552 */ 1553 skb_reserve(skb, reserved); 1554 skb_reset_network_header(skb); 1555 1556 /* Try to align data part correctly */ 1557 if (hhlen) { 1558 skb->data -= hhlen; 1559 skb->tail -= hhlen; 1560 if (len < hhlen) 1561 skb_reset_network_header(skb); 1562 } 1563 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1564 if (err) 1565 goto out_free; 1566 goto retry; 1567 } 1568 1569 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1570 /* Earlier code assumed this would be a VLAN pkt, 1571 * double-check this now that we have the actual 1572 * packet in hand. 1573 */ 1574 struct ethhdr *ehdr; 1575 skb_reset_mac_header(skb); 1576 ehdr = eth_hdr(skb); 1577 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1578 err = -EMSGSIZE; 1579 goto out_unlock; 1580 } 1581 } 1582 1583 skb->protocol = proto; 1584 skb->dev = dev; 1585 skb->priority = sk->sk_priority; 1586 skb->mark = sk->sk_mark; 1587 1588 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1589 1590 if (unlikely(extra_len == 4)) 1591 skb->no_fcs = 1; 1592 1593 skb_probe_transport_header(skb, 0); 1594 1595 dev_queue_xmit(skb); 1596 rcu_read_unlock(); 1597 return len; 1598 1599 out_unlock: 1600 rcu_read_unlock(); 1601 out_free: 1602 kfree_skb(skb); 1603 return err; 1604 } 1605 1606 static unsigned int run_filter(const struct sk_buff *skb, 1607 const struct sock *sk, 1608 unsigned int res) 1609 { 1610 struct sk_filter *filter; 1611 1612 rcu_read_lock(); 1613 filter = rcu_dereference(sk->sk_filter); 1614 if (filter != NULL) 1615 res = SK_RUN_FILTER(filter, skb); 1616 rcu_read_unlock(); 1617 1618 return res; 1619 } 1620 1621 /* 1622 * This function makes lazy skb cloning in hope that most of packets 1623 * are discarded by BPF. 1624 * 1625 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1626 * and skb->cb are mangled. It works because (and until) packets 1627 * falling here are owned by current CPU. Output packets are cloned 1628 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1629 * sequencially, so that if we return skb to original state on exit, 1630 * we will not harm anyone. 1631 */ 1632 1633 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1634 struct packet_type *pt, struct net_device *orig_dev) 1635 { 1636 struct sock *sk; 1637 struct sockaddr_ll *sll; 1638 struct packet_sock *po; 1639 u8 *skb_head = skb->data; 1640 int skb_len = skb->len; 1641 unsigned int snaplen, res; 1642 1643 if (skb->pkt_type == PACKET_LOOPBACK) 1644 goto drop; 1645 1646 sk = pt->af_packet_priv; 1647 po = pkt_sk(sk); 1648 1649 if (!net_eq(dev_net(dev), sock_net(sk))) 1650 goto drop; 1651 1652 skb->dev = dev; 1653 1654 if (dev->header_ops) { 1655 /* The device has an explicit notion of ll header, 1656 * exported to higher levels. 1657 * 1658 * Otherwise, the device hides details of its frame 1659 * structure, so that corresponding packet head is 1660 * never delivered to user. 1661 */ 1662 if (sk->sk_type != SOCK_DGRAM) 1663 skb_push(skb, skb->data - skb_mac_header(skb)); 1664 else if (skb->pkt_type == PACKET_OUTGOING) { 1665 /* Special case: outgoing packets have ll header at head */ 1666 skb_pull(skb, skb_network_offset(skb)); 1667 } 1668 } 1669 1670 snaplen = skb->len; 1671 1672 res = run_filter(skb, sk, snaplen); 1673 if (!res) 1674 goto drop_n_restore; 1675 if (snaplen > res) 1676 snaplen = res; 1677 1678 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1679 goto drop_n_acct; 1680 1681 if (skb_shared(skb)) { 1682 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1683 if (nskb == NULL) 1684 goto drop_n_acct; 1685 1686 if (skb_head != skb->data) { 1687 skb->data = skb_head; 1688 skb->len = skb_len; 1689 } 1690 consume_skb(skb); 1691 skb = nskb; 1692 } 1693 1694 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1695 sizeof(skb->cb)); 1696 1697 sll = &PACKET_SKB_CB(skb)->sa.ll; 1698 sll->sll_family = AF_PACKET; 1699 sll->sll_hatype = dev->type; 1700 sll->sll_protocol = skb->protocol; 1701 sll->sll_pkttype = skb->pkt_type; 1702 if (unlikely(po->origdev)) 1703 sll->sll_ifindex = orig_dev->ifindex; 1704 else 1705 sll->sll_ifindex = dev->ifindex; 1706 1707 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1708 1709 PACKET_SKB_CB(skb)->origlen = skb->len; 1710 1711 if (pskb_trim(skb, snaplen)) 1712 goto drop_n_acct; 1713 1714 skb_set_owner_r(skb, sk); 1715 skb->dev = NULL; 1716 skb_dst_drop(skb); 1717 1718 /* drop conntrack reference */ 1719 nf_reset(skb); 1720 1721 spin_lock(&sk->sk_receive_queue.lock); 1722 po->stats.stats1.tp_packets++; 1723 skb->dropcount = atomic_read(&sk->sk_drops); 1724 __skb_queue_tail(&sk->sk_receive_queue, skb); 1725 spin_unlock(&sk->sk_receive_queue.lock); 1726 sk->sk_data_ready(sk, skb->len); 1727 return 0; 1728 1729 drop_n_acct: 1730 spin_lock(&sk->sk_receive_queue.lock); 1731 po->stats.stats1.tp_drops++; 1732 atomic_inc(&sk->sk_drops); 1733 spin_unlock(&sk->sk_receive_queue.lock); 1734 1735 drop_n_restore: 1736 if (skb_head != skb->data && skb_shared(skb)) { 1737 skb->data = skb_head; 1738 skb->len = skb_len; 1739 } 1740 drop: 1741 consume_skb(skb); 1742 return 0; 1743 } 1744 1745 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1746 struct packet_type *pt, struct net_device *orig_dev) 1747 { 1748 struct sock *sk; 1749 struct packet_sock *po; 1750 struct sockaddr_ll *sll; 1751 union tpacket_uhdr h; 1752 u8 *skb_head = skb->data; 1753 int skb_len = skb->len; 1754 unsigned int snaplen, res; 1755 unsigned long status = TP_STATUS_USER; 1756 unsigned short macoff, netoff, hdrlen; 1757 struct sk_buff *copy_skb = NULL; 1758 struct timespec ts; 1759 __u32 ts_status; 1760 1761 if (skb->pkt_type == PACKET_LOOPBACK) 1762 goto drop; 1763 1764 sk = pt->af_packet_priv; 1765 po = pkt_sk(sk); 1766 1767 if (!net_eq(dev_net(dev), sock_net(sk))) 1768 goto drop; 1769 1770 if (dev->header_ops) { 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 if (skb->ip_summed == CHECKSUM_PARTIAL) 1780 status |= TP_STATUS_CSUMNOTREADY; 1781 1782 snaplen = skb->len; 1783 1784 res = run_filter(skb, sk, snaplen); 1785 if (!res) 1786 goto drop_n_restore; 1787 if (snaplen > res) 1788 snaplen = res; 1789 1790 if (sk->sk_type == SOCK_DGRAM) { 1791 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1792 po->tp_reserve; 1793 } else { 1794 unsigned int maclen = skb_network_offset(skb); 1795 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1796 (maclen < 16 ? 16 : maclen)) + 1797 po->tp_reserve; 1798 macoff = netoff - maclen; 1799 } 1800 if (po->tp_version <= TPACKET_V2) { 1801 if (macoff + snaplen > po->rx_ring.frame_size) { 1802 if (po->copy_thresh && 1803 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1804 if (skb_shared(skb)) { 1805 copy_skb = skb_clone(skb, GFP_ATOMIC); 1806 } else { 1807 copy_skb = skb_get(skb); 1808 skb_head = skb->data; 1809 } 1810 if (copy_skb) 1811 skb_set_owner_r(copy_skb, sk); 1812 } 1813 snaplen = po->rx_ring.frame_size - macoff; 1814 if ((int)snaplen < 0) 1815 snaplen = 0; 1816 } 1817 } 1818 spin_lock(&sk->sk_receive_queue.lock); 1819 h.raw = packet_current_rx_frame(po, skb, 1820 TP_STATUS_KERNEL, (macoff+snaplen)); 1821 if (!h.raw) 1822 goto ring_is_full; 1823 if (po->tp_version <= TPACKET_V2) { 1824 packet_increment_rx_head(po, &po->rx_ring); 1825 /* 1826 * LOSING will be reported till you read the stats, 1827 * because it's COR - Clear On Read. 1828 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1829 * at packet level. 1830 */ 1831 if (po->stats.stats1.tp_drops) 1832 status |= TP_STATUS_LOSING; 1833 } 1834 po->stats.stats1.tp_packets++; 1835 if (copy_skb) { 1836 status |= TP_STATUS_COPY; 1837 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1838 } 1839 spin_unlock(&sk->sk_receive_queue.lock); 1840 1841 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1842 1843 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 1844 getnstimeofday(&ts); 1845 1846 status |= ts_status; 1847 1848 switch (po->tp_version) { 1849 case TPACKET_V1: 1850 h.h1->tp_len = skb->len; 1851 h.h1->tp_snaplen = snaplen; 1852 h.h1->tp_mac = macoff; 1853 h.h1->tp_net = netoff; 1854 h.h1->tp_sec = ts.tv_sec; 1855 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 1856 hdrlen = sizeof(*h.h1); 1857 break; 1858 case TPACKET_V2: 1859 h.h2->tp_len = skb->len; 1860 h.h2->tp_snaplen = snaplen; 1861 h.h2->tp_mac = macoff; 1862 h.h2->tp_net = netoff; 1863 h.h2->tp_sec = ts.tv_sec; 1864 h.h2->tp_nsec = ts.tv_nsec; 1865 if (vlan_tx_tag_present(skb)) { 1866 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1867 status |= TP_STATUS_VLAN_VALID; 1868 } else { 1869 h.h2->tp_vlan_tci = 0; 1870 } 1871 h.h2->tp_padding = 0; 1872 hdrlen = sizeof(*h.h2); 1873 break; 1874 case TPACKET_V3: 1875 /* tp_nxt_offset,vlan are already populated above. 1876 * So DONT clear those fields here 1877 */ 1878 h.h3->tp_status |= status; 1879 h.h3->tp_len = skb->len; 1880 h.h3->tp_snaplen = snaplen; 1881 h.h3->tp_mac = macoff; 1882 h.h3->tp_net = netoff; 1883 h.h3->tp_sec = ts.tv_sec; 1884 h.h3->tp_nsec = ts.tv_nsec; 1885 hdrlen = sizeof(*h.h3); 1886 break; 1887 default: 1888 BUG(); 1889 } 1890 1891 sll = h.raw + TPACKET_ALIGN(hdrlen); 1892 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1893 sll->sll_family = AF_PACKET; 1894 sll->sll_hatype = dev->type; 1895 sll->sll_protocol = skb->protocol; 1896 sll->sll_pkttype = skb->pkt_type; 1897 if (unlikely(po->origdev)) 1898 sll->sll_ifindex = orig_dev->ifindex; 1899 else 1900 sll->sll_ifindex = dev->ifindex; 1901 1902 smp_mb(); 1903 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1904 { 1905 u8 *start, *end; 1906 1907 if (po->tp_version <= TPACKET_V2) { 1908 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1909 + macoff + snaplen); 1910 for (start = h.raw; start < end; start += PAGE_SIZE) 1911 flush_dcache_page(pgv_to_page(start)); 1912 } 1913 smp_wmb(); 1914 } 1915 #endif 1916 if (po->tp_version <= TPACKET_V2) 1917 __packet_set_status(po, h.raw, status); 1918 else 1919 prb_clear_blk_fill_status(&po->rx_ring); 1920 1921 sk->sk_data_ready(sk, 0); 1922 1923 drop_n_restore: 1924 if (skb_head != skb->data && skb_shared(skb)) { 1925 skb->data = skb_head; 1926 skb->len = skb_len; 1927 } 1928 drop: 1929 kfree_skb(skb); 1930 return 0; 1931 1932 ring_is_full: 1933 po->stats.stats1.tp_drops++; 1934 spin_unlock(&sk->sk_receive_queue.lock); 1935 1936 sk->sk_data_ready(sk, 0); 1937 kfree_skb(copy_skb); 1938 goto drop_n_restore; 1939 } 1940 1941 static void tpacket_destruct_skb(struct sk_buff *skb) 1942 { 1943 struct packet_sock *po = pkt_sk(skb->sk); 1944 void *ph; 1945 1946 if (likely(po->tx_ring.pg_vec)) { 1947 __u32 ts; 1948 1949 ph = skb_shinfo(skb)->destructor_arg; 1950 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1951 atomic_dec(&po->tx_ring.pending); 1952 1953 ts = __packet_set_timestamp(po, ph, skb); 1954 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 1955 } 1956 1957 sock_wfree(skb); 1958 } 1959 1960 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1961 void *frame, struct net_device *dev, int size_max, 1962 __be16 proto, unsigned char *addr, int hlen) 1963 { 1964 union tpacket_uhdr ph; 1965 int to_write, offset, len, tp_len, nr_frags, len_max; 1966 struct socket *sock = po->sk.sk_socket; 1967 struct page *page; 1968 void *data; 1969 int err; 1970 1971 ph.raw = frame; 1972 1973 skb->protocol = proto; 1974 skb->dev = dev; 1975 skb->priority = po->sk.sk_priority; 1976 skb->mark = po->sk.sk_mark; 1977 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 1978 skb_shinfo(skb)->destructor_arg = ph.raw; 1979 1980 switch (po->tp_version) { 1981 case TPACKET_V2: 1982 tp_len = ph.h2->tp_len; 1983 break; 1984 default: 1985 tp_len = ph.h1->tp_len; 1986 break; 1987 } 1988 if (unlikely(tp_len > size_max)) { 1989 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1990 return -EMSGSIZE; 1991 } 1992 1993 skb_reserve(skb, hlen); 1994 skb_reset_network_header(skb); 1995 skb_probe_transport_header(skb, 0); 1996 1997 if (po->tp_tx_has_off) { 1998 int off_min, off_max, off; 1999 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2000 off_max = po->tx_ring.frame_size - tp_len; 2001 if (sock->type == SOCK_DGRAM) { 2002 switch (po->tp_version) { 2003 case TPACKET_V2: 2004 off = ph.h2->tp_net; 2005 break; 2006 default: 2007 off = ph.h1->tp_net; 2008 break; 2009 } 2010 } else { 2011 switch (po->tp_version) { 2012 case TPACKET_V2: 2013 off = ph.h2->tp_mac; 2014 break; 2015 default: 2016 off = ph.h1->tp_mac; 2017 break; 2018 } 2019 } 2020 if (unlikely((off < off_min) || (off_max < off))) 2021 return -EINVAL; 2022 data = ph.raw + off; 2023 } else { 2024 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 2025 } 2026 to_write = tp_len; 2027 2028 if (sock->type == SOCK_DGRAM) { 2029 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2030 NULL, tp_len); 2031 if (unlikely(err < 0)) 2032 return -EINVAL; 2033 } else if (dev->hard_header_len) { 2034 /* net device doesn't like empty head */ 2035 if (unlikely(tp_len <= dev->hard_header_len)) { 2036 pr_err("packet size is too short (%d < %d)\n", 2037 tp_len, dev->hard_header_len); 2038 return -EINVAL; 2039 } 2040 2041 skb_push(skb, dev->hard_header_len); 2042 err = skb_store_bits(skb, 0, data, 2043 dev->hard_header_len); 2044 if (unlikely(err)) 2045 return err; 2046 2047 data += dev->hard_header_len; 2048 to_write -= dev->hard_header_len; 2049 } 2050 2051 offset = offset_in_page(data); 2052 len_max = PAGE_SIZE - offset; 2053 len = ((to_write > len_max) ? len_max : to_write); 2054 2055 skb->data_len = to_write; 2056 skb->len += to_write; 2057 skb->truesize += to_write; 2058 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2059 2060 while (likely(to_write)) { 2061 nr_frags = skb_shinfo(skb)->nr_frags; 2062 2063 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2064 pr_err("Packet exceed the number of skb frags(%lu)\n", 2065 MAX_SKB_FRAGS); 2066 return -EFAULT; 2067 } 2068 2069 page = pgv_to_page(data); 2070 data += len; 2071 flush_dcache_page(page); 2072 get_page(page); 2073 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2074 to_write -= len; 2075 offset = 0; 2076 len_max = PAGE_SIZE; 2077 len = ((to_write > len_max) ? len_max : to_write); 2078 } 2079 2080 return tp_len; 2081 } 2082 2083 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2084 { 2085 struct sk_buff *skb; 2086 struct net_device *dev; 2087 __be16 proto; 2088 int err, reserve = 0; 2089 void *ph; 2090 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2091 int tp_len, size_max; 2092 unsigned char *addr; 2093 int len_sum = 0; 2094 int status = TP_STATUS_AVAILABLE; 2095 int hlen, tlen; 2096 2097 mutex_lock(&po->pg_vec_lock); 2098 2099 if (likely(saddr == NULL)) { 2100 dev = packet_cached_dev_get(po); 2101 proto = po->num; 2102 addr = NULL; 2103 } else { 2104 err = -EINVAL; 2105 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2106 goto out; 2107 if (msg->msg_namelen < (saddr->sll_halen 2108 + offsetof(struct sockaddr_ll, 2109 sll_addr))) 2110 goto out; 2111 proto = saddr->sll_protocol; 2112 addr = saddr->sll_addr; 2113 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2114 } 2115 2116 err = -ENXIO; 2117 if (unlikely(dev == NULL)) 2118 goto out; 2119 err = -ENETDOWN; 2120 if (unlikely(!(dev->flags & IFF_UP))) 2121 goto out_put; 2122 2123 reserve = dev->hard_header_len; 2124 2125 size_max = po->tx_ring.frame_size 2126 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2127 2128 if (size_max > dev->mtu + reserve) 2129 size_max = dev->mtu + reserve; 2130 2131 do { 2132 ph = packet_current_frame(po, &po->tx_ring, 2133 TP_STATUS_SEND_REQUEST); 2134 2135 if (unlikely(ph == NULL)) { 2136 schedule(); 2137 continue; 2138 } 2139 2140 status = TP_STATUS_SEND_REQUEST; 2141 hlen = LL_RESERVED_SPACE(dev); 2142 tlen = dev->needed_tailroom; 2143 skb = sock_alloc_send_skb(&po->sk, 2144 hlen + tlen + sizeof(struct sockaddr_ll), 2145 0, &err); 2146 2147 if (unlikely(skb == NULL)) 2148 goto out_status; 2149 2150 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2151 addr, hlen); 2152 2153 if (unlikely(tp_len < 0)) { 2154 if (po->tp_loss) { 2155 __packet_set_status(po, ph, 2156 TP_STATUS_AVAILABLE); 2157 packet_increment_head(&po->tx_ring); 2158 kfree_skb(skb); 2159 continue; 2160 } else { 2161 status = TP_STATUS_WRONG_FORMAT; 2162 err = tp_len; 2163 goto out_status; 2164 } 2165 } 2166 2167 skb->destructor = tpacket_destruct_skb; 2168 __packet_set_status(po, ph, TP_STATUS_SENDING); 2169 atomic_inc(&po->tx_ring.pending); 2170 2171 status = TP_STATUS_SEND_REQUEST; 2172 err = dev_queue_xmit(skb); 2173 if (unlikely(err > 0)) { 2174 err = net_xmit_errno(err); 2175 if (err && __packet_get_status(po, ph) == 2176 TP_STATUS_AVAILABLE) { 2177 /* skb was destructed already */ 2178 skb = NULL; 2179 goto out_status; 2180 } 2181 /* 2182 * skb was dropped but not destructed yet; 2183 * let's treat it like congestion or err < 0 2184 */ 2185 err = 0; 2186 } 2187 packet_increment_head(&po->tx_ring); 2188 len_sum += tp_len; 2189 } while (likely((ph != NULL) || 2190 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2191 (atomic_read(&po->tx_ring.pending)))) 2192 ); 2193 2194 err = len_sum; 2195 goto out_put; 2196 2197 out_status: 2198 __packet_set_status(po, ph, status); 2199 kfree_skb(skb); 2200 out_put: 2201 dev_put(dev); 2202 out: 2203 mutex_unlock(&po->pg_vec_lock); 2204 return err; 2205 } 2206 2207 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2208 size_t reserve, size_t len, 2209 size_t linear, int noblock, 2210 int *err) 2211 { 2212 struct sk_buff *skb; 2213 2214 /* Under a page? Don't bother with paged skb. */ 2215 if (prepad + len < PAGE_SIZE || !linear) 2216 linear = len; 2217 2218 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2219 err, 0); 2220 if (!skb) 2221 return NULL; 2222 2223 skb_reserve(skb, reserve); 2224 skb_put(skb, linear); 2225 skb->data_len = len - linear; 2226 skb->len += len - linear; 2227 2228 return skb; 2229 } 2230 2231 static int packet_snd(struct socket *sock, 2232 struct msghdr *msg, size_t len) 2233 { 2234 struct sock *sk = sock->sk; 2235 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2236 struct sk_buff *skb; 2237 struct net_device *dev; 2238 __be16 proto; 2239 unsigned char *addr; 2240 int err, reserve = 0; 2241 struct virtio_net_hdr vnet_hdr = { 0 }; 2242 int offset = 0; 2243 int vnet_hdr_len; 2244 struct packet_sock *po = pkt_sk(sk); 2245 unsigned short gso_type = 0; 2246 int hlen, tlen; 2247 int extra_len = 0; 2248 2249 /* 2250 * Get and verify the address. 2251 */ 2252 2253 if (likely(saddr == NULL)) { 2254 dev = packet_cached_dev_get(po); 2255 proto = po->num; 2256 addr = NULL; 2257 } else { 2258 err = -EINVAL; 2259 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2260 goto out; 2261 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2262 goto out; 2263 proto = saddr->sll_protocol; 2264 addr = saddr->sll_addr; 2265 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2266 } 2267 2268 err = -ENXIO; 2269 if (unlikely(dev == NULL)) 2270 goto out_unlock; 2271 err = -ENETDOWN; 2272 if (unlikely(!(dev->flags & IFF_UP))) 2273 goto out_unlock; 2274 2275 if (sock->type == SOCK_RAW) 2276 reserve = dev->hard_header_len; 2277 if (po->has_vnet_hdr) { 2278 vnet_hdr_len = sizeof(vnet_hdr); 2279 2280 err = -EINVAL; 2281 if (len < vnet_hdr_len) 2282 goto out_unlock; 2283 2284 len -= vnet_hdr_len; 2285 2286 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2287 vnet_hdr_len); 2288 if (err < 0) 2289 goto out_unlock; 2290 2291 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2292 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2293 vnet_hdr.hdr_len)) 2294 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2295 vnet_hdr.csum_offset + 2; 2296 2297 err = -EINVAL; 2298 if (vnet_hdr.hdr_len > len) 2299 goto out_unlock; 2300 2301 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2302 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2303 case VIRTIO_NET_HDR_GSO_TCPV4: 2304 gso_type = SKB_GSO_TCPV4; 2305 break; 2306 case VIRTIO_NET_HDR_GSO_TCPV6: 2307 gso_type = SKB_GSO_TCPV6; 2308 break; 2309 case VIRTIO_NET_HDR_GSO_UDP: 2310 gso_type = SKB_GSO_UDP; 2311 break; 2312 default: 2313 goto out_unlock; 2314 } 2315 2316 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2317 gso_type |= SKB_GSO_TCP_ECN; 2318 2319 if (vnet_hdr.gso_size == 0) 2320 goto out_unlock; 2321 2322 } 2323 } 2324 2325 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2326 if (!netif_supports_nofcs(dev)) { 2327 err = -EPROTONOSUPPORT; 2328 goto out_unlock; 2329 } 2330 extra_len = 4; /* We're doing our own CRC */ 2331 } 2332 2333 err = -EMSGSIZE; 2334 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2335 goto out_unlock; 2336 2337 err = -ENOBUFS; 2338 hlen = LL_RESERVED_SPACE(dev); 2339 tlen = dev->needed_tailroom; 2340 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2341 msg->msg_flags & MSG_DONTWAIT, &err); 2342 if (skb == NULL) 2343 goto out_unlock; 2344 2345 skb_set_network_header(skb, reserve); 2346 2347 err = -EINVAL; 2348 if (sock->type == SOCK_DGRAM && 2349 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2350 goto out_free; 2351 2352 /* Returns -EFAULT on error */ 2353 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2354 if (err) 2355 goto out_free; 2356 2357 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2358 2359 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2360 /* Earlier code assumed this would be a VLAN pkt, 2361 * double-check this now that we have the actual 2362 * packet in hand. 2363 */ 2364 struct ethhdr *ehdr; 2365 skb_reset_mac_header(skb); 2366 ehdr = eth_hdr(skb); 2367 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2368 err = -EMSGSIZE; 2369 goto out_free; 2370 } 2371 } 2372 2373 skb->protocol = proto; 2374 skb->dev = dev; 2375 skb->priority = sk->sk_priority; 2376 skb->mark = sk->sk_mark; 2377 2378 if (po->has_vnet_hdr) { 2379 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2380 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2381 vnet_hdr.csum_offset)) { 2382 err = -EINVAL; 2383 goto out_free; 2384 } 2385 } 2386 2387 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2388 skb_shinfo(skb)->gso_type = gso_type; 2389 2390 /* Header must be checked, and gso_segs computed. */ 2391 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2392 skb_shinfo(skb)->gso_segs = 0; 2393 2394 len += vnet_hdr_len; 2395 } 2396 2397 skb_probe_transport_header(skb, reserve); 2398 2399 if (unlikely(extra_len == 4)) 2400 skb->no_fcs = 1; 2401 2402 /* 2403 * Now send it 2404 */ 2405 2406 err = dev_queue_xmit(skb); 2407 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2408 goto out_unlock; 2409 2410 dev_put(dev); 2411 2412 return len; 2413 2414 out_free: 2415 kfree_skb(skb); 2416 out_unlock: 2417 if (dev) 2418 dev_put(dev); 2419 out: 2420 return err; 2421 } 2422 2423 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2424 struct msghdr *msg, size_t len) 2425 { 2426 struct sock *sk = sock->sk; 2427 struct packet_sock *po = pkt_sk(sk); 2428 if (po->tx_ring.pg_vec) 2429 return tpacket_snd(po, msg); 2430 else 2431 return packet_snd(sock, msg, len); 2432 } 2433 2434 /* 2435 * Close a PACKET socket. This is fairly simple. We immediately go 2436 * to 'closed' state and remove our protocol entry in the device list. 2437 */ 2438 2439 static int packet_release(struct socket *sock) 2440 { 2441 struct sock *sk = sock->sk; 2442 struct packet_sock *po; 2443 struct net *net; 2444 union tpacket_req_u req_u; 2445 2446 if (!sk) 2447 return 0; 2448 2449 net = sock_net(sk); 2450 po = pkt_sk(sk); 2451 2452 mutex_lock(&net->packet.sklist_lock); 2453 sk_del_node_init_rcu(sk); 2454 mutex_unlock(&net->packet.sklist_lock); 2455 2456 preempt_disable(); 2457 sock_prot_inuse_add(net, sk->sk_prot, -1); 2458 preempt_enable(); 2459 2460 spin_lock(&po->bind_lock); 2461 unregister_prot_hook(sk, false); 2462 packet_cached_dev_reset(po); 2463 2464 if (po->prot_hook.dev) { 2465 dev_put(po->prot_hook.dev); 2466 po->prot_hook.dev = NULL; 2467 } 2468 spin_unlock(&po->bind_lock); 2469 2470 packet_flush_mclist(sk); 2471 2472 if (po->rx_ring.pg_vec) { 2473 memset(&req_u, 0, sizeof(req_u)); 2474 packet_set_ring(sk, &req_u, 1, 0); 2475 } 2476 2477 if (po->tx_ring.pg_vec) { 2478 memset(&req_u, 0, sizeof(req_u)); 2479 packet_set_ring(sk, &req_u, 1, 1); 2480 } 2481 2482 fanout_release(sk); 2483 2484 synchronize_net(); 2485 /* 2486 * Now the socket is dead. No more input will appear. 2487 */ 2488 sock_orphan(sk); 2489 sock->sk = NULL; 2490 2491 /* Purge queues */ 2492 2493 skb_queue_purge(&sk->sk_receive_queue); 2494 sk_refcnt_debug_release(sk); 2495 2496 sock_put(sk); 2497 return 0; 2498 } 2499 2500 /* 2501 * Attach a packet hook. 2502 */ 2503 2504 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2505 { 2506 struct packet_sock *po = pkt_sk(sk); 2507 2508 if (po->fanout) { 2509 if (dev) 2510 dev_put(dev); 2511 2512 return -EINVAL; 2513 } 2514 2515 lock_sock(sk); 2516 2517 spin_lock(&po->bind_lock); 2518 unregister_prot_hook(sk, true); 2519 2520 po->num = protocol; 2521 po->prot_hook.type = protocol; 2522 if (po->prot_hook.dev) 2523 dev_put(po->prot_hook.dev); 2524 2525 po->prot_hook.dev = dev; 2526 po->ifindex = dev ? dev->ifindex : 0; 2527 2528 packet_cached_dev_assign(po, dev); 2529 2530 if (protocol == 0) 2531 goto out_unlock; 2532 2533 if (!dev || (dev->flags & IFF_UP)) { 2534 register_prot_hook(sk); 2535 } else { 2536 sk->sk_err = ENETDOWN; 2537 if (!sock_flag(sk, SOCK_DEAD)) 2538 sk->sk_error_report(sk); 2539 } 2540 2541 out_unlock: 2542 spin_unlock(&po->bind_lock); 2543 release_sock(sk); 2544 return 0; 2545 } 2546 2547 /* 2548 * Bind a packet socket to a device 2549 */ 2550 2551 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2552 int addr_len) 2553 { 2554 struct sock *sk = sock->sk; 2555 char name[15]; 2556 struct net_device *dev; 2557 int err = -ENODEV; 2558 2559 /* 2560 * Check legality 2561 */ 2562 2563 if (addr_len != sizeof(struct sockaddr)) 2564 return -EINVAL; 2565 strlcpy(name, uaddr->sa_data, sizeof(name)); 2566 2567 dev = dev_get_by_name(sock_net(sk), name); 2568 if (dev) 2569 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2570 return err; 2571 } 2572 2573 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2574 { 2575 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2576 struct sock *sk = sock->sk; 2577 struct net_device *dev = NULL; 2578 int err; 2579 2580 2581 /* 2582 * Check legality 2583 */ 2584 2585 if (addr_len < sizeof(struct sockaddr_ll)) 2586 return -EINVAL; 2587 if (sll->sll_family != AF_PACKET) 2588 return -EINVAL; 2589 2590 if (sll->sll_ifindex) { 2591 err = -ENODEV; 2592 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2593 if (dev == NULL) 2594 goto out; 2595 } 2596 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2597 2598 out: 2599 return err; 2600 } 2601 2602 static struct proto packet_proto = { 2603 .name = "PACKET", 2604 .owner = THIS_MODULE, 2605 .obj_size = sizeof(struct packet_sock), 2606 }; 2607 2608 /* 2609 * Create a packet of type SOCK_PACKET. 2610 */ 2611 2612 static int packet_create(struct net *net, struct socket *sock, int protocol, 2613 int kern) 2614 { 2615 struct sock *sk; 2616 struct packet_sock *po; 2617 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2618 int err; 2619 2620 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 2621 return -EPERM; 2622 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2623 sock->type != SOCK_PACKET) 2624 return -ESOCKTNOSUPPORT; 2625 2626 sock->state = SS_UNCONNECTED; 2627 2628 err = -ENOBUFS; 2629 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2630 if (sk == NULL) 2631 goto out; 2632 2633 sock->ops = &packet_ops; 2634 if (sock->type == SOCK_PACKET) 2635 sock->ops = &packet_ops_spkt; 2636 2637 sock_init_data(sock, sk); 2638 2639 po = pkt_sk(sk); 2640 sk->sk_family = PF_PACKET; 2641 po->num = proto; 2642 2643 packet_cached_dev_reset(po); 2644 2645 sk->sk_destruct = packet_sock_destruct; 2646 sk_refcnt_debug_inc(sk); 2647 2648 /* 2649 * Attach a protocol block 2650 */ 2651 2652 spin_lock_init(&po->bind_lock); 2653 mutex_init(&po->pg_vec_lock); 2654 po->prot_hook.func = packet_rcv; 2655 2656 if (sock->type == SOCK_PACKET) 2657 po->prot_hook.func = packet_rcv_spkt; 2658 2659 po->prot_hook.af_packet_priv = sk; 2660 2661 if (proto) { 2662 po->prot_hook.type = proto; 2663 register_prot_hook(sk); 2664 } 2665 2666 mutex_lock(&net->packet.sklist_lock); 2667 sk_add_node_rcu(sk, &net->packet.sklist); 2668 mutex_unlock(&net->packet.sklist_lock); 2669 2670 preempt_disable(); 2671 sock_prot_inuse_add(net, &packet_proto, 1); 2672 preempt_enable(); 2673 2674 return 0; 2675 out: 2676 return err; 2677 } 2678 2679 /* 2680 * Pull a packet from our receive queue and hand it to the user. 2681 * If necessary we block. 2682 */ 2683 2684 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2685 struct msghdr *msg, size_t len, int flags) 2686 { 2687 struct sock *sk = sock->sk; 2688 struct sk_buff *skb; 2689 int copied, err; 2690 int vnet_hdr_len = 0; 2691 2692 err = -EINVAL; 2693 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2694 goto out; 2695 2696 #if 0 2697 /* What error should we return now? EUNATTACH? */ 2698 if (pkt_sk(sk)->ifindex < 0) 2699 return -ENODEV; 2700 #endif 2701 2702 if (flags & MSG_ERRQUEUE) { 2703 err = sock_recv_errqueue(sk, msg, len, 2704 SOL_PACKET, PACKET_TX_TIMESTAMP); 2705 goto out; 2706 } 2707 2708 /* 2709 * Call the generic datagram receiver. This handles all sorts 2710 * of horrible races and re-entrancy so we can forget about it 2711 * in the protocol layers. 2712 * 2713 * Now it will return ENETDOWN, if device have just gone down, 2714 * but then it will block. 2715 */ 2716 2717 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2718 2719 /* 2720 * An error occurred so return it. Because skb_recv_datagram() 2721 * handles the blocking we don't see and worry about blocking 2722 * retries. 2723 */ 2724 2725 if (skb == NULL) 2726 goto out; 2727 2728 if (pkt_sk(sk)->has_vnet_hdr) { 2729 struct virtio_net_hdr vnet_hdr = { 0 }; 2730 2731 err = -EINVAL; 2732 vnet_hdr_len = sizeof(vnet_hdr); 2733 if (len < vnet_hdr_len) 2734 goto out_free; 2735 2736 len -= vnet_hdr_len; 2737 2738 if (skb_is_gso(skb)) { 2739 struct skb_shared_info *sinfo = skb_shinfo(skb); 2740 2741 /* This is a hint as to how much should be linear. */ 2742 vnet_hdr.hdr_len = skb_headlen(skb); 2743 vnet_hdr.gso_size = sinfo->gso_size; 2744 if (sinfo->gso_type & SKB_GSO_TCPV4) 2745 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2746 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2747 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2748 else if (sinfo->gso_type & SKB_GSO_UDP) 2749 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2750 else if (sinfo->gso_type & SKB_GSO_FCOE) 2751 goto out_free; 2752 else 2753 BUG(); 2754 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2755 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2756 } else 2757 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2758 2759 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2760 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2761 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2762 vnet_hdr.csum_offset = skb->csum_offset; 2763 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2764 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2765 } /* else everything is zero */ 2766 2767 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2768 vnet_hdr_len); 2769 if (err < 0) 2770 goto out_free; 2771 } 2772 2773 /* You lose any data beyond the buffer you gave. If it worries 2774 * a user program they can ask the device for its MTU 2775 * anyway. 2776 */ 2777 copied = skb->len; 2778 if (copied > len) { 2779 copied = len; 2780 msg->msg_flags |= MSG_TRUNC; 2781 } 2782 2783 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2784 if (err) 2785 goto out_free; 2786 2787 sock_recv_ts_and_drops(msg, sk, skb); 2788 2789 if (msg->msg_name) { 2790 /* If the address length field is there to be filled 2791 * in, we fill it in now. 2792 */ 2793 if (sock->type == SOCK_PACKET) { 2794 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2795 } else { 2796 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 2797 msg->msg_namelen = sll->sll_halen + 2798 offsetof(struct sockaddr_ll, sll_addr); 2799 } 2800 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2801 msg->msg_namelen); 2802 } 2803 2804 if (pkt_sk(sk)->auxdata) { 2805 struct tpacket_auxdata aux; 2806 2807 aux.tp_status = TP_STATUS_USER; 2808 if (skb->ip_summed == CHECKSUM_PARTIAL) 2809 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2810 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2811 aux.tp_snaplen = skb->len; 2812 aux.tp_mac = 0; 2813 aux.tp_net = skb_network_offset(skb); 2814 if (vlan_tx_tag_present(skb)) { 2815 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2816 aux.tp_status |= TP_STATUS_VLAN_VALID; 2817 } else { 2818 aux.tp_vlan_tci = 0; 2819 } 2820 aux.tp_padding = 0; 2821 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2822 } 2823 2824 /* 2825 * Free or return the buffer as appropriate. Again this 2826 * hides all the races and re-entrancy issues from us. 2827 */ 2828 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2829 2830 out_free: 2831 skb_free_datagram(sk, skb); 2832 out: 2833 return err; 2834 } 2835 2836 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2837 int *uaddr_len, int peer) 2838 { 2839 struct net_device *dev; 2840 struct sock *sk = sock->sk; 2841 2842 if (peer) 2843 return -EOPNOTSUPP; 2844 2845 uaddr->sa_family = AF_PACKET; 2846 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 2847 rcu_read_lock(); 2848 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2849 if (dev) 2850 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 2851 rcu_read_unlock(); 2852 *uaddr_len = sizeof(*uaddr); 2853 2854 return 0; 2855 } 2856 2857 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2858 int *uaddr_len, int peer) 2859 { 2860 struct net_device *dev; 2861 struct sock *sk = sock->sk; 2862 struct packet_sock *po = pkt_sk(sk); 2863 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2864 2865 if (peer) 2866 return -EOPNOTSUPP; 2867 2868 sll->sll_family = AF_PACKET; 2869 sll->sll_ifindex = po->ifindex; 2870 sll->sll_protocol = po->num; 2871 sll->sll_pkttype = 0; 2872 rcu_read_lock(); 2873 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2874 if (dev) { 2875 sll->sll_hatype = dev->type; 2876 sll->sll_halen = dev->addr_len; 2877 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2878 } else { 2879 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2880 sll->sll_halen = 0; 2881 } 2882 rcu_read_unlock(); 2883 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2884 2885 return 0; 2886 } 2887 2888 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2889 int what) 2890 { 2891 switch (i->type) { 2892 case PACKET_MR_MULTICAST: 2893 if (i->alen != dev->addr_len) 2894 return -EINVAL; 2895 if (what > 0) 2896 return dev_mc_add(dev, i->addr); 2897 else 2898 return dev_mc_del(dev, i->addr); 2899 break; 2900 case PACKET_MR_PROMISC: 2901 return dev_set_promiscuity(dev, what); 2902 break; 2903 case PACKET_MR_ALLMULTI: 2904 return dev_set_allmulti(dev, what); 2905 break; 2906 case PACKET_MR_UNICAST: 2907 if (i->alen != dev->addr_len) 2908 return -EINVAL; 2909 if (what > 0) 2910 return dev_uc_add(dev, i->addr); 2911 else 2912 return dev_uc_del(dev, i->addr); 2913 break; 2914 default: 2915 break; 2916 } 2917 return 0; 2918 } 2919 2920 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2921 { 2922 for ( ; i; i = i->next) { 2923 if (i->ifindex == dev->ifindex) 2924 packet_dev_mc(dev, i, what); 2925 } 2926 } 2927 2928 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2929 { 2930 struct packet_sock *po = pkt_sk(sk); 2931 struct packet_mclist *ml, *i; 2932 struct net_device *dev; 2933 int err; 2934 2935 rtnl_lock(); 2936 2937 err = -ENODEV; 2938 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2939 if (!dev) 2940 goto done; 2941 2942 err = -EINVAL; 2943 if (mreq->mr_alen > dev->addr_len) 2944 goto done; 2945 2946 err = -ENOBUFS; 2947 i = kmalloc(sizeof(*i), GFP_KERNEL); 2948 if (i == NULL) 2949 goto done; 2950 2951 err = 0; 2952 for (ml = po->mclist; ml; ml = ml->next) { 2953 if (ml->ifindex == mreq->mr_ifindex && 2954 ml->type == mreq->mr_type && 2955 ml->alen == mreq->mr_alen && 2956 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2957 ml->count++; 2958 /* Free the new element ... */ 2959 kfree(i); 2960 goto done; 2961 } 2962 } 2963 2964 i->type = mreq->mr_type; 2965 i->ifindex = mreq->mr_ifindex; 2966 i->alen = mreq->mr_alen; 2967 memcpy(i->addr, mreq->mr_address, i->alen); 2968 i->count = 1; 2969 i->next = po->mclist; 2970 po->mclist = i; 2971 err = packet_dev_mc(dev, i, 1); 2972 if (err) { 2973 po->mclist = i->next; 2974 kfree(i); 2975 } 2976 2977 done: 2978 rtnl_unlock(); 2979 return err; 2980 } 2981 2982 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2983 { 2984 struct packet_mclist *ml, **mlp; 2985 2986 rtnl_lock(); 2987 2988 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 2989 if (ml->ifindex == mreq->mr_ifindex && 2990 ml->type == mreq->mr_type && 2991 ml->alen == mreq->mr_alen && 2992 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2993 if (--ml->count == 0) { 2994 struct net_device *dev; 2995 *mlp = ml->next; 2996 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 2997 if (dev) 2998 packet_dev_mc(dev, ml, -1); 2999 kfree(ml); 3000 } 3001 rtnl_unlock(); 3002 return 0; 3003 } 3004 } 3005 rtnl_unlock(); 3006 return -EADDRNOTAVAIL; 3007 } 3008 3009 static void packet_flush_mclist(struct sock *sk) 3010 { 3011 struct packet_sock *po = pkt_sk(sk); 3012 struct packet_mclist *ml; 3013 3014 if (!po->mclist) 3015 return; 3016 3017 rtnl_lock(); 3018 while ((ml = po->mclist) != NULL) { 3019 struct net_device *dev; 3020 3021 po->mclist = ml->next; 3022 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3023 if (dev != NULL) 3024 packet_dev_mc(dev, ml, -1); 3025 kfree(ml); 3026 } 3027 rtnl_unlock(); 3028 } 3029 3030 static int 3031 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3032 { 3033 struct sock *sk = sock->sk; 3034 struct packet_sock *po = pkt_sk(sk); 3035 int ret; 3036 3037 if (level != SOL_PACKET) 3038 return -ENOPROTOOPT; 3039 3040 switch (optname) { 3041 case PACKET_ADD_MEMBERSHIP: 3042 case PACKET_DROP_MEMBERSHIP: 3043 { 3044 struct packet_mreq_max mreq; 3045 int len = optlen; 3046 memset(&mreq, 0, sizeof(mreq)); 3047 if (len < sizeof(struct packet_mreq)) 3048 return -EINVAL; 3049 if (len > sizeof(mreq)) 3050 len = sizeof(mreq); 3051 if (copy_from_user(&mreq, optval, len)) 3052 return -EFAULT; 3053 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3054 return -EINVAL; 3055 if (optname == PACKET_ADD_MEMBERSHIP) 3056 ret = packet_mc_add(sk, &mreq); 3057 else 3058 ret = packet_mc_drop(sk, &mreq); 3059 return ret; 3060 } 3061 3062 case PACKET_RX_RING: 3063 case PACKET_TX_RING: 3064 { 3065 union tpacket_req_u req_u; 3066 int len; 3067 3068 switch (po->tp_version) { 3069 case TPACKET_V1: 3070 case TPACKET_V2: 3071 len = sizeof(req_u.req); 3072 break; 3073 case TPACKET_V3: 3074 default: 3075 len = sizeof(req_u.req3); 3076 break; 3077 } 3078 if (optlen < len) 3079 return -EINVAL; 3080 if (pkt_sk(sk)->has_vnet_hdr) 3081 return -EINVAL; 3082 if (copy_from_user(&req_u.req, optval, len)) 3083 return -EFAULT; 3084 return packet_set_ring(sk, &req_u, 0, 3085 optname == PACKET_TX_RING); 3086 } 3087 case PACKET_COPY_THRESH: 3088 { 3089 int val; 3090 3091 if (optlen != sizeof(val)) 3092 return -EINVAL; 3093 if (copy_from_user(&val, optval, sizeof(val))) 3094 return -EFAULT; 3095 3096 pkt_sk(sk)->copy_thresh = val; 3097 return 0; 3098 } 3099 case PACKET_VERSION: 3100 { 3101 int val; 3102 3103 if (optlen != sizeof(val)) 3104 return -EINVAL; 3105 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3106 return -EBUSY; 3107 if (copy_from_user(&val, optval, sizeof(val))) 3108 return -EFAULT; 3109 switch (val) { 3110 case TPACKET_V1: 3111 case TPACKET_V2: 3112 case TPACKET_V3: 3113 po->tp_version = val; 3114 return 0; 3115 default: 3116 return -EINVAL; 3117 } 3118 } 3119 case PACKET_RESERVE: 3120 { 3121 unsigned int val; 3122 3123 if (optlen != sizeof(val)) 3124 return -EINVAL; 3125 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3126 return -EBUSY; 3127 if (copy_from_user(&val, optval, sizeof(val))) 3128 return -EFAULT; 3129 po->tp_reserve = val; 3130 return 0; 3131 } 3132 case PACKET_LOSS: 3133 { 3134 unsigned int val; 3135 3136 if (optlen != sizeof(val)) 3137 return -EINVAL; 3138 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3139 return -EBUSY; 3140 if (copy_from_user(&val, optval, sizeof(val))) 3141 return -EFAULT; 3142 po->tp_loss = !!val; 3143 return 0; 3144 } 3145 case PACKET_AUXDATA: 3146 { 3147 int val; 3148 3149 if (optlen < sizeof(val)) 3150 return -EINVAL; 3151 if (copy_from_user(&val, optval, sizeof(val))) 3152 return -EFAULT; 3153 3154 po->auxdata = !!val; 3155 return 0; 3156 } 3157 case PACKET_ORIGDEV: 3158 { 3159 int val; 3160 3161 if (optlen < sizeof(val)) 3162 return -EINVAL; 3163 if (copy_from_user(&val, optval, sizeof(val))) 3164 return -EFAULT; 3165 3166 po->origdev = !!val; 3167 return 0; 3168 } 3169 case PACKET_VNET_HDR: 3170 { 3171 int val; 3172 3173 if (sock->type != SOCK_RAW) 3174 return -EINVAL; 3175 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3176 return -EBUSY; 3177 if (optlen < sizeof(val)) 3178 return -EINVAL; 3179 if (copy_from_user(&val, optval, sizeof(val))) 3180 return -EFAULT; 3181 3182 po->has_vnet_hdr = !!val; 3183 return 0; 3184 } 3185 case PACKET_TIMESTAMP: 3186 { 3187 int val; 3188 3189 if (optlen != sizeof(val)) 3190 return -EINVAL; 3191 if (copy_from_user(&val, optval, sizeof(val))) 3192 return -EFAULT; 3193 3194 po->tp_tstamp = val; 3195 return 0; 3196 } 3197 case PACKET_FANOUT: 3198 { 3199 int val; 3200 3201 if (optlen != sizeof(val)) 3202 return -EINVAL; 3203 if (copy_from_user(&val, optval, sizeof(val))) 3204 return -EFAULT; 3205 3206 return fanout_add(sk, val & 0xffff, val >> 16); 3207 } 3208 case PACKET_TX_HAS_OFF: 3209 { 3210 unsigned int val; 3211 3212 if (optlen != sizeof(val)) 3213 return -EINVAL; 3214 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3215 return -EBUSY; 3216 if (copy_from_user(&val, optval, sizeof(val))) 3217 return -EFAULT; 3218 po->tp_tx_has_off = !!val; 3219 return 0; 3220 } 3221 default: 3222 return -ENOPROTOOPT; 3223 } 3224 } 3225 3226 static int packet_getsockopt(struct socket *sock, int level, int optname, 3227 char __user *optval, int __user *optlen) 3228 { 3229 int len; 3230 int val, lv = sizeof(val); 3231 struct sock *sk = sock->sk; 3232 struct packet_sock *po = pkt_sk(sk); 3233 void *data = &val; 3234 union tpacket_stats_u st; 3235 3236 if (level != SOL_PACKET) 3237 return -ENOPROTOOPT; 3238 3239 if (get_user(len, optlen)) 3240 return -EFAULT; 3241 3242 if (len < 0) 3243 return -EINVAL; 3244 3245 switch (optname) { 3246 case PACKET_STATISTICS: 3247 spin_lock_bh(&sk->sk_receive_queue.lock); 3248 memcpy(&st, &po->stats, sizeof(st)); 3249 memset(&po->stats, 0, sizeof(po->stats)); 3250 spin_unlock_bh(&sk->sk_receive_queue.lock); 3251 3252 if (po->tp_version == TPACKET_V3) { 3253 lv = sizeof(struct tpacket_stats_v3); 3254 st.stats3.tp_packets += st.stats3.tp_drops; 3255 data = &st.stats3; 3256 } else { 3257 lv = sizeof(struct tpacket_stats); 3258 st.stats1.tp_packets += st.stats1.tp_drops; 3259 data = &st.stats1; 3260 } 3261 3262 break; 3263 case PACKET_AUXDATA: 3264 val = po->auxdata; 3265 break; 3266 case PACKET_ORIGDEV: 3267 val = po->origdev; 3268 break; 3269 case PACKET_VNET_HDR: 3270 val = po->has_vnet_hdr; 3271 break; 3272 case PACKET_VERSION: 3273 val = po->tp_version; 3274 break; 3275 case PACKET_HDRLEN: 3276 if (len > sizeof(int)) 3277 len = sizeof(int); 3278 if (copy_from_user(&val, optval, len)) 3279 return -EFAULT; 3280 switch (val) { 3281 case TPACKET_V1: 3282 val = sizeof(struct tpacket_hdr); 3283 break; 3284 case TPACKET_V2: 3285 val = sizeof(struct tpacket2_hdr); 3286 break; 3287 case TPACKET_V3: 3288 val = sizeof(struct tpacket3_hdr); 3289 break; 3290 default: 3291 return -EINVAL; 3292 } 3293 break; 3294 case PACKET_RESERVE: 3295 val = po->tp_reserve; 3296 break; 3297 case PACKET_LOSS: 3298 val = po->tp_loss; 3299 break; 3300 case PACKET_TIMESTAMP: 3301 val = po->tp_tstamp; 3302 break; 3303 case PACKET_FANOUT: 3304 val = (po->fanout ? 3305 ((u32)po->fanout->id | 3306 ((u32)po->fanout->type << 16) | 3307 ((u32)po->fanout->flags << 24)) : 3308 0); 3309 break; 3310 case PACKET_TX_HAS_OFF: 3311 val = po->tp_tx_has_off; 3312 break; 3313 default: 3314 return -ENOPROTOOPT; 3315 } 3316 3317 if (len > lv) 3318 len = lv; 3319 if (put_user(len, optlen)) 3320 return -EFAULT; 3321 if (copy_to_user(optval, data, len)) 3322 return -EFAULT; 3323 return 0; 3324 } 3325 3326 3327 static int packet_notifier(struct notifier_block *this, 3328 unsigned long msg, void *ptr) 3329 { 3330 struct sock *sk; 3331 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3332 struct net *net = dev_net(dev); 3333 3334 rcu_read_lock(); 3335 sk_for_each_rcu(sk, &net->packet.sklist) { 3336 struct packet_sock *po = pkt_sk(sk); 3337 3338 switch (msg) { 3339 case NETDEV_UNREGISTER: 3340 if (po->mclist) 3341 packet_dev_mclist(dev, po->mclist, -1); 3342 /* fallthrough */ 3343 3344 case NETDEV_DOWN: 3345 if (dev->ifindex == po->ifindex) { 3346 spin_lock(&po->bind_lock); 3347 if (po->running) { 3348 __unregister_prot_hook(sk, false); 3349 sk->sk_err = ENETDOWN; 3350 if (!sock_flag(sk, SOCK_DEAD)) 3351 sk->sk_error_report(sk); 3352 } 3353 if (msg == NETDEV_UNREGISTER) { 3354 packet_cached_dev_reset(po); 3355 po->ifindex = -1; 3356 if (po->prot_hook.dev) 3357 dev_put(po->prot_hook.dev); 3358 po->prot_hook.dev = NULL; 3359 } 3360 spin_unlock(&po->bind_lock); 3361 } 3362 break; 3363 case NETDEV_UP: 3364 if (dev->ifindex == po->ifindex) { 3365 spin_lock(&po->bind_lock); 3366 if (po->num) 3367 register_prot_hook(sk); 3368 spin_unlock(&po->bind_lock); 3369 } 3370 break; 3371 } 3372 } 3373 rcu_read_unlock(); 3374 return NOTIFY_DONE; 3375 } 3376 3377 3378 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3379 unsigned long arg) 3380 { 3381 struct sock *sk = sock->sk; 3382 3383 switch (cmd) { 3384 case SIOCOUTQ: 3385 { 3386 int amount = sk_wmem_alloc_get(sk); 3387 3388 return put_user(amount, (int __user *)arg); 3389 } 3390 case SIOCINQ: 3391 { 3392 struct sk_buff *skb; 3393 int amount = 0; 3394 3395 spin_lock_bh(&sk->sk_receive_queue.lock); 3396 skb = skb_peek(&sk->sk_receive_queue); 3397 if (skb) 3398 amount = skb->len; 3399 spin_unlock_bh(&sk->sk_receive_queue.lock); 3400 return put_user(amount, (int __user *)arg); 3401 } 3402 case SIOCGSTAMP: 3403 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3404 case SIOCGSTAMPNS: 3405 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3406 3407 #ifdef CONFIG_INET 3408 case SIOCADDRT: 3409 case SIOCDELRT: 3410 case SIOCDARP: 3411 case SIOCGARP: 3412 case SIOCSARP: 3413 case SIOCGIFADDR: 3414 case SIOCSIFADDR: 3415 case SIOCGIFBRDADDR: 3416 case SIOCSIFBRDADDR: 3417 case SIOCGIFNETMASK: 3418 case SIOCSIFNETMASK: 3419 case SIOCGIFDSTADDR: 3420 case SIOCSIFDSTADDR: 3421 case SIOCSIFFLAGS: 3422 return inet_dgram_ops.ioctl(sock, cmd, arg); 3423 #endif 3424 3425 default: 3426 return -ENOIOCTLCMD; 3427 } 3428 return 0; 3429 } 3430 3431 static unsigned int packet_poll(struct file *file, struct socket *sock, 3432 poll_table *wait) 3433 { 3434 struct sock *sk = sock->sk; 3435 struct packet_sock *po = pkt_sk(sk); 3436 unsigned int mask = datagram_poll(file, sock, wait); 3437 3438 spin_lock_bh(&sk->sk_receive_queue.lock); 3439 if (po->rx_ring.pg_vec) { 3440 if (!packet_previous_rx_frame(po, &po->rx_ring, 3441 TP_STATUS_KERNEL)) 3442 mask |= POLLIN | POLLRDNORM; 3443 } 3444 spin_unlock_bh(&sk->sk_receive_queue.lock); 3445 spin_lock_bh(&sk->sk_write_queue.lock); 3446 if (po->tx_ring.pg_vec) { 3447 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3448 mask |= POLLOUT | POLLWRNORM; 3449 } 3450 spin_unlock_bh(&sk->sk_write_queue.lock); 3451 return mask; 3452 } 3453 3454 3455 /* Dirty? Well, I still did not learn better way to account 3456 * for user mmaps. 3457 */ 3458 3459 static void packet_mm_open(struct vm_area_struct *vma) 3460 { 3461 struct file *file = vma->vm_file; 3462 struct socket *sock = file->private_data; 3463 struct sock *sk = sock->sk; 3464 3465 if (sk) 3466 atomic_inc(&pkt_sk(sk)->mapped); 3467 } 3468 3469 static void packet_mm_close(struct vm_area_struct *vma) 3470 { 3471 struct file *file = vma->vm_file; 3472 struct socket *sock = file->private_data; 3473 struct sock *sk = sock->sk; 3474 3475 if (sk) 3476 atomic_dec(&pkt_sk(sk)->mapped); 3477 } 3478 3479 static const struct vm_operations_struct packet_mmap_ops = { 3480 .open = packet_mm_open, 3481 .close = packet_mm_close, 3482 }; 3483 3484 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3485 unsigned int len) 3486 { 3487 int i; 3488 3489 for (i = 0; i < len; i++) { 3490 if (likely(pg_vec[i].buffer)) { 3491 if (is_vmalloc_addr(pg_vec[i].buffer)) 3492 vfree(pg_vec[i].buffer); 3493 else 3494 free_pages((unsigned long)pg_vec[i].buffer, 3495 order); 3496 pg_vec[i].buffer = NULL; 3497 } 3498 } 3499 kfree(pg_vec); 3500 } 3501 3502 static char *alloc_one_pg_vec_page(unsigned long order) 3503 { 3504 char *buffer = NULL; 3505 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3506 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3507 3508 buffer = (char *) __get_free_pages(gfp_flags, order); 3509 3510 if (buffer) 3511 return buffer; 3512 3513 /* 3514 * __get_free_pages failed, fall back to vmalloc 3515 */ 3516 buffer = vzalloc((1 << order) * PAGE_SIZE); 3517 3518 if (buffer) 3519 return buffer; 3520 3521 /* 3522 * vmalloc failed, lets dig into swap here 3523 */ 3524 gfp_flags &= ~__GFP_NORETRY; 3525 buffer = (char *)__get_free_pages(gfp_flags, order); 3526 if (buffer) 3527 return buffer; 3528 3529 /* 3530 * complete and utter failure 3531 */ 3532 return NULL; 3533 } 3534 3535 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3536 { 3537 unsigned int block_nr = req->tp_block_nr; 3538 struct pgv *pg_vec; 3539 int i; 3540 3541 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3542 if (unlikely(!pg_vec)) 3543 goto out; 3544 3545 for (i = 0; i < block_nr; i++) { 3546 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3547 if (unlikely(!pg_vec[i].buffer)) 3548 goto out_free_pgvec; 3549 } 3550 3551 out: 3552 return pg_vec; 3553 3554 out_free_pgvec: 3555 free_pg_vec(pg_vec, order, block_nr); 3556 pg_vec = NULL; 3557 goto out; 3558 } 3559 3560 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3561 int closing, int tx_ring) 3562 { 3563 struct pgv *pg_vec = NULL; 3564 struct packet_sock *po = pkt_sk(sk); 3565 int was_running, order = 0; 3566 struct packet_ring_buffer *rb; 3567 struct sk_buff_head *rb_queue; 3568 __be16 num; 3569 int err = -EINVAL; 3570 /* Added to avoid minimal code churn */ 3571 struct tpacket_req *req = &req_u->req; 3572 3573 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3574 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3575 WARN(1, "Tx-ring is not supported.\n"); 3576 goto out; 3577 } 3578 3579 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3580 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3581 3582 err = -EBUSY; 3583 if (!closing) { 3584 if (atomic_read(&po->mapped)) 3585 goto out; 3586 if (atomic_read(&rb->pending)) 3587 goto out; 3588 } 3589 3590 if (req->tp_block_nr) { 3591 /* Sanity tests and some calculations */ 3592 err = -EBUSY; 3593 if (unlikely(rb->pg_vec)) 3594 goto out; 3595 3596 switch (po->tp_version) { 3597 case TPACKET_V1: 3598 po->tp_hdrlen = TPACKET_HDRLEN; 3599 break; 3600 case TPACKET_V2: 3601 po->tp_hdrlen = TPACKET2_HDRLEN; 3602 break; 3603 case TPACKET_V3: 3604 po->tp_hdrlen = TPACKET3_HDRLEN; 3605 break; 3606 } 3607 3608 err = -EINVAL; 3609 if (unlikely((int)req->tp_block_size <= 0)) 3610 goto out; 3611 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3612 goto out; 3613 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3614 po->tp_reserve)) 3615 goto out; 3616 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3617 goto out; 3618 3619 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3620 if (unlikely(rb->frames_per_block <= 0)) 3621 goto out; 3622 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3623 req->tp_frame_nr)) 3624 goto out; 3625 3626 err = -ENOMEM; 3627 order = get_order(req->tp_block_size); 3628 pg_vec = alloc_pg_vec(req, order); 3629 if (unlikely(!pg_vec)) 3630 goto out; 3631 switch (po->tp_version) { 3632 case TPACKET_V3: 3633 /* Transmit path is not supported. We checked 3634 * it above but just being paranoid 3635 */ 3636 if (!tx_ring) 3637 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3638 break; 3639 default: 3640 break; 3641 } 3642 } 3643 /* Done */ 3644 else { 3645 err = -EINVAL; 3646 if (unlikely(req->tp_frame_nr)) 3647 goto out; 3648 } 3649 3650 lock_sock(sk); 3651 3652 /* Detach socket from network */ 3653 spin_lock(&po->bind_lock); 3654 was_running = po->running; 3655 num = po->num; 3656 if (was_running) { 3657 po->num = 0; 3658 __unregister_prot_hook(sk, false); 3659 } 3660 spin_unlock(&po->bind_lock); 3661 3662 synchronize_net(); 3663 3664 err = -EBUSY; 3665 mutex_lock(&po->pg_vec_lock); 3666 if (closing || atomic_read(&po->mapped) == 0) { 3667 err = 0; 3668 spin_lock_bh(&rb_queue->lock); 3669 swap(rb->pg_vec, pg_vec); 3670 rb->frame_max = (req->tp_frame_nr - 1); 3671 rb->head = 0; 3672 rb->frame_size = req->tp_frame_size; 3673 spin_unlock_bh(&rb_queue->lock); 3674 3675 swap(rb->pg_vec_order, order); 3676 swap(rb->pg_vec_len, req->tp_block_nr); 3677 3678 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3679 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3680 tpacket_rcv : packet_rcv; 3681 skb_queue_purge(rb_queue); 3682 if (atomic_read(&po->mapped)) 3683 pr_err("packet_mmap: vma is busy: %d\n", 3684 atomic_read(&po->mapped)); 3685 } 3686 mutex_unlock(&po->pg_vec_lock); 3687 3688 spin_lock(&po->bind_lock); 3689 if (was_running) { 3690 po->num = num; 3691 register_prot_hook(sk); 3692 } 3693 spin_unlock(&po->bind_lock); 3694 if (closing && (po->tp_version > TPACKET_V2)) { 3695 /* Because we don't support block-based V3 on tx-ring */ 3696 if (!tx_ring) 3697 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3698 } 3699 release_sock(sk); 3700 3701 if (pg_vec) 3702 free_pg_vec(pg_vec, order, req->tp_block_nr); 3703 out: 3704 return err; 3705 } 3706 3707 static int packet_mmap(struct file *file, struct socket *sock, 3708 struct vm_area_struct *vma) 3709 { 3710 struct sock *sk = sock->sk; 3711 struct packet_sock *po = pkt_sk(sk); 3712 unsigned long size, expected_size; 3713 struct packet_ring_buffer *rb; 3714 unsigned long start; 3715 int err = -EINVAL; 3716 int i; 3717 3718 if (vma->vm_pgoff) 3719 return -EINVAL; 3720 3721 mutex_lock(&po->pg_vec_lock); 3722 3723 expected_size = 0; 3724 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3725 if (rb->pg_vec) { 3726 expected_size += rb->pg_vec_len 3727 * rb->pg_vec_pages 3728 * PAGE_SIZE; 3729 } 3730 } 3731 3732 if (expected_size == 0) 3733 goto out; 3734 3735 size = vma->vm_end - vma->vm_start; 3736 if (size != expected_size) 3737 goto out; 3738 3739 start = vma->vm_start; 3740 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3741 if (rb->pg_vec == NULL) 3742 continue; 3743 3744 for (i = 0; i < rb->pg_vec_len; i++) { 3745 struct page *page; 3746 void *kaddr = rb->pg_vec[i].buffer; 3747 int pg_num; 3748 3749 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3750 page = pgv_to_page(kaddr); 3751 err = vm_insert_page(vma, start, page); 3752 if (unlikely(err)) 3753 goto out; 3754 start += PAGE_SIZE; 3755 kaddr += PAGE_SIZE; 3756 } 3757 } 3758 } 3759 3760 atomic_inc(&po->mapped); 3761 vma->vm_ops = &packet_mmap_ops; 3762 err = 0; 3763 3764 out: 3765 mutex_unlock(&po->pg_vec_lock); 3766 return err; 3767 } 3768 3769 static const struct proto_ops packet_ops_spkt = { 3770 .family = PF_PACKET, 3771 .owner = THIS_MODULE, 3772 .release = packet_release, 3773 .bind = packet_bind_spkt, 3774 .connect = sock_no_connect, 3775 .socketpair = sock_no_socketpair, 3776 .accept = sock_no_accept, 3777 .getname = packet_getname_spkt, 3778 .poll = datagram_poll, 3779 .ioctl = packet_ioctl, 3780 .listen = sock_no_listen, 3781 .shutdown = sock_no_shutdown, 3782 .setsockopt = sock_no_setsockopt, 3783 .getsockopt = sock_no_getsockopt, 3784 .sendmsg = packet_sendmsg_spkt, 3785 .recvmsg = packet_recvmsg, 3786 .mmap = sock_no_mmap, 3787 .sendpage = sock_no_sendpage, 3788 }; 3789 3790 static const struct proto_ops packet_ops = { 3791 .family = PF_PACKET, 3792 .owner = THIS_MODULE, 3793 .release = packet_release, 3794 .bind = packet_bind, 3795 .connect = sock_no_connect, 3796 .socketpair = sock_no_socketpair, 3797 .accept = sock_no_accept, 3798 .getname = packet_getname, 3799 .poll = packet_poll, 3800 .ioctl = packet_ioctl, 3801 .listen = sock_no_listen, 3802 .shutdown = sock_no_shutdown, 3803 .setsockopt = packet_setsockopt, 3804 .getsockopt = packet_getsockopt, 3805 .sendmsg = packet_sendmsg, 3806 .recvmsg = packet_recvmsg, 3807 .mmap = packet_mmap, 3808 .sendpage = sock_no_sendpage, 3809 }; 3810 3811 static const struct net_proto_family packet_family_ops = { 3812 .family = PF_PACKET, 3813 .create = packet_create, 3814 .owner = THIS_MODULE, 3815 }; 3816 3817 static struct notifier_block packet_netdev_notifier = { 3818 .notifier_call = packet_notifier, 3819 }; 3820 3821 #ifdef CONFIG_PROC_FS 3822 3823 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3824 __acquires(RCU) 3825 { 3826 struct net *net = seq_file_net(seq); 3827 3828 rcu_read_lock(); 3829 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3830 } 3831 3832 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3833 { 3834 struct net *net = seq_file_net(seq); 3835 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3836 } 3837 3838 static void packet_seq_stop(struct seq_file *seq, void *v) 3839 __releases(RCU) 3840 { 3841 rcu_read_unlock(); 3842 } 3843 3844 static int packet_seq_show(struct seq_file *seq, void *v) 3845 { 3846 if (v == SEQ_START_TOKEN) 3847 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3848 else { 3849 struct sock *s = sk_entry(v); 3850 const struct packet_sock *po = pkt_sk(s); 3851 3852 seq_printf(seq, 3853 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3854 s, 3855 atomic_read(&s->sk_refcnt), 3856 s->sk_type, 3857 ntohs(po->num), 3858 po->ifindex, 3859 po->running, 3860 atomic_read(&s->sk_rmem_alloc), 3861 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 3862 sock_i_ino(s)); 3863 } 3864 3865 return 0; 3866 } 3867 3868 static const struct seq_operations packet_seq_ops = { 3869 .start = packet_seq_start, 3870 .next = packet_seq_next, 3871 .stop = packet_seq_stop, 3872 .show = packet_seq_show, 3873 }; 3874 3875 static int packet_seq_open(struct inode *inode, struct file *file) 3876 { 3877 return seq_open_net(inode, file, &packet_seq_ops, 3878 sizeof(struct seq_net_private)); 3879 } 3880 3881 static const struct file_operations packet_seq_fops = { 3882 .owner = THIS_MODULE, 3883 .open = packet_seq_open, 3884 .read = seq_read, 3885 .llseek = seq_lseek, 3886 .release = seq_release_net, 3887 }; 3888 3889 #endif 3890 3891 static int __net_init packet_net_init(struct net *net) 3892 { 3893 mutex_init(&net->packet.sklist_lock); 3894 INIT_HLIST_HEAD(&net->packet.sklist); 3895 3896 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 3897 return -ENOMEM; 3898 3899 return 0; 3900 } 3901 3902 static void __net_exit packet_net_exit(struct net *net) 3903 { 3904 remove_proc_entry("packet", net->proc_net); 3905 } 3906 3907 static struct pernet_operations packet_net_ops = { 3908 .init = packet_net_init, 3909 .exit = packet_net_exit, 3910 }; 3911 3912 3913 static void __exit packet_exit(void) 3914 { 3915 unregister_netdevice_notifier(&packet_netdev_notifier); 3916 unregister_pernet_subsys(&packet_net_ops); 3917 sock_unregister(PF_PACKET); 3918 proto_unregister(&packet_proto); 3919 } 3920 3921 static int __init packet_init(void) 3922 { 3923 int rc = proto_register(&packet_proto, 0); 3924 3925 if (rc != 0) 3926 goto out; 3927 3928 sock_register(&packet_family_ops); 3929 register_pernet_subsys(&packet_net_ops); 3930 register_netdevice_notifier(&packet_netdev_notifier); 3931 out: 3932 return rc; 3933 } 3934 3935 module_init(packet_init); 3936 module_exit(packet_exit); 3937 MODULE_LICENSE("GPL"); 3938 MODULE_ALIAS_NETPROTO(PF_PACKET); 3939