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 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 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 162 int closing, int tx_ring); 163 164 165 #define V3_ALIGNMENT (8) 166 167 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 168 169 #define BLK_PLUS_PRIV(sz_of_priv) \ 170 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 171 172 #define PGV_FROM_VMALLOC 1 173 174 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 175 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 176 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 177 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 178 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 179 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 180 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 181 182 struct packet_sock; 183 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 184 185 static void *packet_previous_frame(struct packet_sock *po, 186 struct packet_ring_buffer *rb, 187 int status); 188 static void packet_increment_head(struct packet_ring_buffer *buff); 189 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 190 struct tpacket_block_desc *); 191 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 192 struct packet_sock *); 193 static void prb_retire_current_block(struct tpacket_kbdq_core *, 194 struct packet_sock *, unsigned int status); 195 static int prb_queue_frozen(struct tpacket_kbdq_core *); 196 static void prb_open_block(struct tpacket_kbdq_core *, 197 struct tpacket_block_desc *); 198 static void prb_retire_rx_blk_timer_expired(unsigned long); 199 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 200 static void prb_init_blk_timer(struct packet_sock *, 201 struct tpacket_kbdq_core *, 202 void (*func) (unsigned long)); 203 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 204 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 205 struct tpacket3_hdr *); 206 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 207 struct tpacket3_hdr *); 208 static void packet_flush_mclist(struct sock *sk); 209 210 struct packet_skb_cb { 211 unsigned int origlen; 212 union { 213 struct sockaddr_pkt pkt; 214 struct sockaddr_ll ll; 215 } sa; 216 }; 217 218 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 219 220 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 221 #define GET_PBLOCK_DESC(x, bid) \ 222 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 223 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 224 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 225 #define GET_NEXT_PRB_BLK_NUM(x) \ 226 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 227 ((x)->kactive_blk_num+1) : 0) 228 229 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 230 static void __fanout_link(struct sock *sk, struct packet_sock *po); 231 232 /* register_prot_hook must be invoked with the po->bind_lock held, 233 * or from a context in which asynchronous accesses to the packet 234 * socket is not possible (packet_create()). 235 */ 236 static void register_prot_hook(struct sock *sk) 237 { 238 struct packet_sock *po = pkt_sk(sk); 239 if (!po->running) { 240 if (po->fanout) 241 __fanout_link(sk, po); 242 else 243 dev_add_pack(&po->prot_hook); 244 sock_hold(sk); 245 po->running = 1; 246 } 247 } 248 249 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 250 * held. If the sync parameter is true, we will temporarily drop 251 * the po->bind_lock and do a synchronize_net to make sure no 252 * asynchronous packet processing paths still refer to the elements 253 * of po->prot_hook. If the sync parameter is false, it is the 254 * callers responsibility to take care of this. 255 */ 256 static void __unregister_prot_hook(struct sock *sk, bool sync) 257 { 258 struct packet_sock *po = pkt_sk(sk); 259 260 po->running = 0; 261 if (po->fanout) 262 __fanout_unlink(sk, po); 263 else 264 __dev_remove_pack(&po->prot_hook); 265 __sock_put(sk); 266 267 if (sync) { 268 spin_unlock(&po->bind_lock); 269 synchronize_net(); 270 spin_lock(&po->bind_lock); 271 } 272 } 273 274 static void unregister_prot_hook(struct sock *sk, bool sync) 275 { 276 struct packet_sock *po = pkt_sk(sk); 277 278 if (po->running) 279 __unregister_prot_hook(sk, sync); 280 } 281 282 static inline __pure struct page *pgv_to_page(void *addr) 283 { 284 if (is_vmalloc_addr(addr)) 285 return vmalloc_to_page(addr); 286 return virt_to_page(addr); 287 } 288 289 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 290 { 291 union { 292 struct tpacket_hdr *h1; 293 struct tpacket2_hdr *h2; 294 void *raw; 295 } h; 296 297 h.raw = frame; 298 switch (po->tp_version) { 299 case TPACKET_V1: 300 h.h1->tp_status = status; 301 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 302 break; 303 case TPACKET_V2: 304 h.h2->tp_status = status; 305 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 306 break; 307 case TPACKET_V3: 308 default: 309 WARN(1, "TPACKET version not supported.\n"); 310 BUG(); 311 } 312 313 smp_wmb(); 314 } 315 316 static int __packet_get_status(struct packet_sock *po, void *frame) 317 { 318 union { 319 struct tpacket_hdr *h1; 320 struct tpacket2_hdr *h2; 321 void *raw; 322 } h; 323 324 smp_rmb(); 325 326 h.raw = frame; 327 switch (po->tp_version) { 328 case TPACKET_V1: 329 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 330 return h.h1->tp_status; 331 case TPACKET_V2: 332 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 333 return h.h2->tp_status; 334 case TPACKET_V3: 335 default: 336 WARN(1, "TPACKET version not supported.\n"); 337 BUG(); 338 return 0; 339 } 340 } 341 342 static void *packet_lookup_frame(struct packet_sock *po, 343 struct packet_ring_buffer *rb, 344 unsigned int position, 345 int status) 346 { 347 unsigned int pg_vec_pos, frame_offset; 348 union { 349 struct tpacket_hdr *h1; 350 struct tpacket2_hdr *h2; 351 void *raw; 352 } h; 353 354 pg_vec_pos = position / rb->frames_per_block; 355 frame_offset = position % rb->frames_per_block; 356 357 h.raw = rb->pg_vec[pg_vec_pos].buffer + 358 (frame_offset * rb->frame_size); 359 360 if (status != __packet_get_status(po, h.raw)) 361 return NULL; 362 363 return h.raw; 364 } 365 366 static void *packet_current_frame(struct packet_sock *po, 367 struct packet_ring_buffer *rb, 368 int status) 369 { 370 return packet_lookup_frame(po, rb, rb->head, status); 371 } 372 373 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 374 { 375 del_timer_sync(&pkc->retire_blk_timer); 376 } 377 378 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 379 int tx_ring, 380 struct sk_buff_head *rb_queue) 381 { 382 struct tpacket_kbdq_core *pkc; 383 384 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 385 386 spin_lock(&rb_queue->lock); 387 pkc->delete_blk_timer = 1; 388 spin_unlock(&rb_queue->lock); 389 390 prb_del_retire_blk_timer(pkc); 391 } 392 393 static void prb_init_blk_timer(struct packet_sock *po, 394 struct tpacket_kbdq_core *pkc, 395 void (*func) (unsigned long)) 396 { 397 init_timer(&pkc->retire_blk_timer); 398 pkc->retire_blk_timer.data = (long)po; 399 pkc->retire_blk_timer.function = func; 400 pkc->retire_blk_timer.expires = jiffies; 401 } 402 403 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 404 { 405 struct tpacket_kbdq_core *pkc; 406 407 if (tx_ring) 408 BUG(); 409 410 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 411 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 412 } 413 414 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 415 int blk_size_in_bytes) 416 { 417 struct net_device *dev; 418 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 419 struct ethtool_cmd ecmd; 420 int err; 421 u32 speed; 422 423 rtnl_lock(); 424 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 425 if (unlikely(!dev)) { 426 rtnl_unlock(); 427 return DEFAULT_PRB_RETIRE_TOV; 428 } 429 err = __ethtool_get_settings(dev, &ecmd); 430 speed = ethtool_cmd_speed(&ecmd); 431 rtnl_unlock(); 432 if (!err) { 433 /* 434 * If the link speed is so slow you don't really 435 * need to worry about perf anyways 436 */ 437 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 438 return DEFAULT_PRB_RETIRE_TOV; 439 } else { 440 msec = 1; 441 div = speed / 1000; 442 } 443 } 444 445 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 446 447 if (div) 448 mbits /= div; 449 450 tmo = mbits * msec; 451 452 if (div) 453 return tmo+1; 454 return tmo; 455 } 456 457 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 458 union tpacket_req_u *req_u) 459 { 460 p1->feature_req_word = req_u->req3.tp_feature_req_word; 461 } 462 463 static void init_prb_bdqc(struct packet_sock *po, 464 struct packet_ring_buffer *rb, 465 struct pgv *pg_vec, 466 union tpacket_req_u *req_u, int tx_ring) 467 { 468 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 469 struct tpacket_block_desc *pbd; 470 471 memset(p1, 0x0, sizeof(*p1)); 472 473 p1->knxt_seq_num = 1; 474 p1->pkbdq = pg_vec; 475 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 476 p1->pkblk_start = pg_vec[0].buffer; 477 p1->kblk_size = req_u->req3.tp_block_size; 478 p1->knum_blocks = req_u->req3.tp_block_nr; 479 p1->hdrlen = po->tp_hdrlen; 480 p1->version = po->tp_version; 481 p1->last_kactive_blk_num = 0; 482 po->stats_u.stats3.tp_freeze_q_cnt = 0; 483 if (req_u->req3.tp_retire_blk_tov) 484 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 485 else 486 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 487 req_u->req3.tp_block_size); 488 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 489 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 490 491 prb_init_ft_ops(p1, req_u); 492 prb_setup_retire_blk_timer(po, tx_ring); 493 prb_open_block(p1, pbd); 494 } 495 496 /* Do NOT update the last_blk_num first. 497 * Assumes sk_buff_head lock is held. 498 */ 499 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 500 { 501 mod_timer(&pkc->retire_blk_timer, 502 jiffies + pkc->tov_in_jiffies); 503 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 504 } 505 506 /* 507 * Timer logic: 508 * 1) We refresh the timer only when we open a block. 509 * By doing this we don't waste cycles refreshing the timer 510 * on packet-by-packet basis. 511 * 512 * With a 1MB block-size, on a 1Gbps line, it will take 513 * i) ~8 ms to fill a block + ii) memcpy etc. 514 * In this cut we are not accounting for the memcpy time. 515 * 516 * So, if the user sets the 'tmo' to 10ms then the timer 517 * will never fire while the block is still getting filled 518 * (which is what we want). However, the user could choose 519 * to close a block early and that's fine. 520 * 521 * But when the timer does fire, we check whether or not to refresh it. 522 * Since the tmo granularity is in msecs, it is not too expensive 523 * to refresh the timer, lets say every '8' msecs. 524 * Either the user can set the 'tmo' or we can derive it based on 525 * a) line-speed and b) block-size. 526 * prb_calc_retire_blk_tmo() calculates the tmo. 527 * 528 */ 529 static void prb_retire_rx_blk_timer_expired(unsigned long data) 530 { 531 struct packet_sock *po = (struct packet_sock *)data; 532 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 533 unsigned int frozen; 534 struct tpacket_block_desc *pbd; 535 536 spin_lock(&po->sk.sk_receive_queue.lock); 537 538 frozen = prb_queue_frozen(pkc); 539 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 540 541 if (unlikely(pkc->delete_blk_timer)) 542 goto out; 543 544 /* We only need to plug the race when the block is partially filled. 545 * tpacket_rcv: 546 * lock(); increment BLOCK_NUM_PKTS; unlock() 547 * copy_bits() is in progress ... 548 * timer fires on other cpu: 549 * we can't retire the current block because copy_bits 550 * is in progress. 551 * 552 */ 553 if (BLOCK_NUM_PKTS(pbd)) { 554 while (atomic_read(&pkc->blk_fill_in_prog)) { 555 /* Waiting for skb_copy_bits to finish... */ 556 cpu_relax(); 557 } 558 } 559 560 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 561 if (!frozen) { 562 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 563 if (!prb_dispatch_next_block(pkc, po)) 564 goto refresh_timer; 565 else 566 goto out; 567 } else { 568 /* Case 1. Queue was frozen because user-space was 569 * lagging behind. 570 */ 571 if (prb_curr_blk_in_use(pkc, pbd)) { 572 /* 573 * Ok, user-space is still behind. 574 * So just refresh the timer. 575 */ 576 goto refresh_timer; 577 } else { 578 /* Case 2. queue was frozen,user-space caught up, 579 * now the link went idle && the timer fired. 580 * We don't have a block to close.So we open this 581 * block and restart the timer. 582 * opening a block thaws the queue,restarts timer 583 * Thawing/timer-refresh is a side effect. 584 */ 585 prb_open_block(pkc, pbd); 586 goto out; 587 } 588 } 589 } 590 591 refresh_timer: 592 _prb_refresh_rx_retire_blk_timer(pkc); 593 594 out: 595 spin_unlock(&po->sk.sk_receive_queue.lock); 596 } 597 598 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 599 struct tpacket_block_desc *pbd1, __u32 status) 600 { 601 /* Flush everything minus the block header */ 602 603 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 604 u8 *start, *end; 605 606 start = (u8 *)pbd1; 607 608 /* Skip the block header(we know header WILL fit in 4K) */ 609 start += PAGE_SIZE; 610 611 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 612 for (; start < end; start += PAGE_SIZE) 613 flush_dcache_page(pgv_to_page(start)); 614 615 smp_wmb(); 616 #endif 617 618 /* Now update the block status. */ 619 620 BLOCK_STATUS(pbd1) = status; 621 622 /* Flush the block header */ 623 624 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 625 start = (u8 *)pbd1; 626 flush_dcache_page(pgv_to_page(start)); 627 628 smp_wmb(); 629 #endif 630 } 631 632 /* 633 * Side effect: 634 * 635 * 1) flush the block 636 * 2) Increment active_blk_num 637 * 638 * Note:We DONT refresh the timer on purpose. 639 * Because almost always the next block will be opened. 640 */ 641 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 642 struct tpacket_block_desc *pbd1, 643 struct packet_sock *po, unsigned int stat) 644 { 645 __u32 status = TP_STATUS_USER | stat; 646 647 struct tpacket3_hdr *last_pkt; 648 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 649 650 if (po->stats.tp_drops) 651 status |= TP_STATUS_LOSING; 652 653 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 654 last_pkt->tp_next_offset = 0; 655 656 /* Get the ts of the last pkt */ 657 if (BLOCK_NUM_PKTS(pbd1)) { 658 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 659 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 660 } else { 661 /* Ok, we tmo'd - so get the current time */ 662 struct timespec ts; 663 getnstimeofday(&ts); 664 h1->ts_last_pkt.ts_sec = ts.tv_sec; 665 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 666 } 667 668 smp_wmb(); 669 670 /* Flush the block */ 671 prb_flush_block(pkc1, pbd1, status); 672 673 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 674 } 675 676 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 677 { 678 pkc->reset_pending_on_curr_blk = 0; 679 } 680 681 /* 682 * Side effect of opening a block: 683 * 684 * 1) prb_queue is thawed. 685 * 2) retire_blk_timer is refreshed. 686 * 687 */ 688 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 689 struct tpacket_block_desc *pbd1) 690 { 691 struct timespec ts; 692 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 693 694 smp_rmb(); 695 696 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { 697 698 /* We could have just memset this but we will lose the 699 * flexibility of making the priv area sticky 700 */ 701 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 702 BLOCK_NUM_PKTS(pbd1) = 0; 703 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 704 getnstimeofday(&ts); 705 h1->ts_first_pkt.ts_sec = ts.tv_sec; 706 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 707 pkc1->pkblk_start = (char *)pbd1; 708 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 709 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 710 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 711 pbd1->version = pkc1->version; 712 pkc1->prev = pkc1->nxt_offset; 713 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 714 prb_thaw_queue(pkc1); 715 _prb_refresh_rx_retire_blk_timer(pkc1); 716 717 smp_wmb(); 718 719 return; 720 } 721 722 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", 723 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); 724 dump_stack(); 725 BUG(); 726 } 727 728 /* 729 * Queue freeze logic: 730 * 1) Assume tp_block_nr = 8 blocks. 731 * 2) At time 't0', user opens Rx ring. 732 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 733 * 4) user-space is either sleeping or processing block '0'. 734 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 735 * it will close block-7,loop around and try to fill block '0'. 736 * call-flow: 737 * __packet_lookup_frame_in_block 738 * prb_retire_current_block() 739 * prb_dispatch_next_block() 740 * |->(BLOCK_STATUS == USER) evaluates to true 741 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 742 * 6) Now there are two cases: 743 * 6.1) Link goes idle right after the queue is frozen. 744 * But remember, the last open_block() refreshed the timer. 745 * When this timer expires,it will refresh itself so that we can 746 * re-open block-0 in near future. 747 * 6.2) Link is busy and keeps on receiving packets. This is a simple 748 * case and __packet_lookup_frame_in_block will check if block-0 749 * is free and can now be re-used. 750 */ 751 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 752 struct packet_sock *po) 753 { 754 pkc->reset_pending_on_curr_blk = 1; 755 po->stats_u.stats3.tp_freeze_q_cnt++; 756 } 757 758 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 759 760 /* 761 * If the next block is free then we will dispatch it 762 * and return a good offset. 763 * Else, we will freeze the queue. 764 * So, caller must check the return value. 765 */ 766 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 767 struct packet_sock *po) 768 { 769 struct tpacket_block_desc *pbd; 770 771 smp_rmb(); 772 773 /* 1. Get current block num */ 774 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 775 776 /* 2. If this block is currently in_use then freeze the queue */ 777 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 778 prb_freeze_queue(pkc, po); 779 return NULL; 780 } 781 782 /* 783 * 3. 784 * open this block and return the offset where the first packet 785 * needs to get stored. 786 */ 787 prb_open_block(pkc, pbd); 788 return (void *)pkc->nxt_offset; 789 } 790 791 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 792 struct packet_sock *po, unsigned int status) 793 { 794 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 795 796 /* retire/close the current block */ 797 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 798 /* 799 * Plug the case where copy_bits() is in progress on 800 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 801 * have space to copy the pkt in the current block and 802 * called prb_retire_current_block() 803 * 804 * We don't need to worry about the TMO case because 805 * the timer-handler already handled this case. 806 */ 807 if (!(status & TP_STATUS_BLK_TMO)) { 808 while (atomic_read(&pkc->blk_fill_in_prog)) { 809 /* Waiting for skb_copy_bits to finish... */ 810 cpu_relax(); 811 } 812 } 813 prb_close_block(pkc, pbd, po, status); 814 return; 815 } 816 817 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); 818 dump_stack(); 819 BUG(); 820 } 821 822 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 823 struct tpacket_block_desc *pbd) 824 { 825 return TP_STATUS_USER & BLOCK_STATUS(pbd); 826 } 827 828 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 829 { 830 return pkc->reset_pending_on_curr_blk; 831 } 832 833 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 834 { 835 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 836 atomic_dec(&pkc->blk_fill_in_prog); 837 } 838 839 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 840 struct tpacket3_hdr *ppd) 841 { 842 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 843 } 844 845 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 846 struct tpacket3_hdr *ppd) 847 { 848 ppd->hv1.tp_rxhash = 0; 849 } 850 851 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 852 struct tpacket3_hdr *ppd) 853 { 854 if (vlan_tx_tag_present(pkc->skb)) { 855 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 856 ppd->tp_status = TP_STATUS_VLAN_VALID; 857 } else { 858 ppd->hv1.tp_vlan_tci = 0; 859 ppd->tp_status = TP_STATUS_AVAILABLE; 860 } 861 } 862 863 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 864 struct tpacket3_hdr *ppd) 865 { 866 prb_fill_vlan_info(pkc, ppd); 867 868 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 869 prb_fill_rxhash(pkc, ppd); 870 else 871 prb_clear_rxhash(pkc, ppd); 872 } 873 874 static void prb_fill_curr_block(char *curr, 875 struct tpacket_kbdq_core *pkc, 876 struct tpacket_block_desc *pbd, 877 unsigned int len) 878 { 879 struct tpacket3_hdr *ppd; 880 881 ppd = (struct tpacket3_hdr *)curr; 882 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 883 pkc->prev = curr; 884 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 885 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 886 BLOCK_NUM_PKTS(pbd) += 1; 887 atomic_inc(&pkc->blk_fill_in_prog); 888 prb_run_all_ft_ops(pkc, ppd); 889 } 890 891 /* Assumes caller has the sk->rx_queue.lock */ 892 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 893 struct sk_buff *skb, 894 int status, 895 unsigned int len 896 ) 897 { 898 struct tpacket_kbdq_core *pkc; 899 struct tpacket_block_desc *pbd; 900 char *curr, *end; 901 902 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 903 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 904 905 /* Queue is frozen when user space is lagging behind */ 906 if (prb_queue_frozen(pkc)) { 907 /* 908 * Check if that last block which caused the queue to freeze, 909 * is still in_use by user-space. 910 */ 911 if (prb_curr_blk_in_use(pkc, pbd)) { 912 /* Can't record this packet */ 913 return NULL; 914 } else { 915 /* 916 * Ok, the block was released by user-space. 917 * Now let's open that block. 918 * opening a block also thaws the queue. 919 * Thawing is a side effect. 920 */ 921 prb_open_block(pkc, pbd); 922 } 923 } 924 925 smp_mb(); 926 curr = pkc->nxt_offset; 927 pkc->skb = skb; 928 end = (char *)pbd + pkc->kblk_size; 929 930 /* first try the current block */ 931 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 932 prb_fill_curr_block(curr, pkc, pbd, len); 933 return (void *)curr; 934 } 935 936 /* Ok, close the current block */ 937 prb_retire_current_block(pkc, po, 0); 938 939 /* Now, try to dispatch the next block */ 940 curr = (char *)prb_dispatch_next_block(pkc, po); 941 if (curr) { 942 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 943 prb_fill_curr_block(curr, pkc, pbd, len); 944 return (void *)curr; 945 } 946 947 /* 948 * No free blocks are available.user_space hasn't caught up yet. 949 * Queue was just frozen and now this packet will get dropped. 950 */ 951 return NULL; 952 } 953 954 static void *packet_current_rx_frame(struct packet_sock *po, 955 struct sk_buff *skb, 956 int status, unsigned int len) 957 { 958 char *curr = NULL; 959 switch (po->tp_version) { 960 case TPACKET_V1: 961 case TPACKET_V2: 962 curr = packet_lookup_frame(po, &po->rx_ring, 963 po->rx_ring.head, status); 964 return curr; 965 case TPACKET_V3: 966 return __packet_lookup_frame_in_block(po, skb, status, len); 967 default: 968 WARN(1, "TPACKET version not supported\n"); 969 BUG(); 970 return NULL; 971 } 972 } 973 974 static void *prb_lookup_block(struct packet_sock *po, 975 struct packet_ring_buffer *rb, 976 unsigned int previous, 977 int status) 978 { 979 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 980 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous); 981 982 if (status != BLOCK_STATUS(pbd)) 983 return NULL; 984 return pbd; 985 } 986 987 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 988 { 989 unsigned int prev; 990 if (rb->prb_bdqc.kactive_blk_num) 991 prev = rb->prb_bdqc.kactive_blk_num-1; 992 else 993 prev = rb->prb_bdqc.knum_blocks-1; 994 return prev; 995 } 996 997 /* Assumes caller has held the rx_queue.lock */ 998 static void *__prb_previous_block(struct packet_sock *po, 999 struct packet_ring_buffer *rb, 1000 int status) 1001 { 1002 unsigned int previous = prb_previous_blk_num(rb); 1003 return prb_lookup_block(po, rb, previous, status); 1004 } 1005 1006 static void *packet_previous_rx_frame(struct packet_sock *po, 1007 struct packet_ring_buffer *rb, 1008 int status) 1009 { 1010 if (po->tp_version <= TPACKET_V2) 1011 return packet_previous_frame(po, rb, status); 1012 1013 return __prb_previous_block(po, rb, status); 1014 } 1015 1016 static void packet_increment_rx_head(struct packet_sock *po, 1017 struct packet_ring_buffer *rb) 1018 { 1019 switch (po->tp_version) { 1020 case TPACKET_V1: 1021 case TPACKET_V2: 1022 return packet_increment_head(rb); 1023 case TPACKET_V3: 1024 default: 1025 WARN(1, "TPACKET version not supported.\n"); 1026 BUG(); 1027 return; 1028 } 1029 } 1030 1031 static void *packet_previous_frame(struct packet_sock *po, 1032 struct packet_ring_buffer *rb, 1033 int status) 1034 { 1035 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1036 return packet_lookup_frame(po, rb, previous, status); 1037 } 1038 1039 static void packet_increment_head(struct packet_ring_buffer *buff) 1040 { 1041 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1042 } 1043 1044 static void packet_sock_destruct(struct sock *sk) 1045 { 1046 skb_queue_purge(&sk->sk_error_queue); 1047 1048 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1049 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1050 1051 if (!sock_flag(sk, SOCK_DEAD)) { 1052 pr_err("Attempt to release alive packet socket: %p\n", sk); 1053 return; 1054 } 1055 1056 sk_refcnt_debug_dec(sk); 1057 } 1058 1059 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1060 { 1061 int x = atomic_read(&f->rr_cur) + 1; 1062 1063 if (x >= num) 1064 x = 0; 1065 1066 return x; 1067 } 1068 1069 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1070 { 1071 u32 idx, hash = skb->rxhash; 1072 1073 idx = ((u64)hash * num) >> 32; 1074 1075 return f->arr[idx]; 1076 } 1077 1078 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1079 { 1080 int cur, old; 1081 1082 cur = atomic_read(&f->rr_cur); 1083 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1084 fanout_rr_next(f, num))) != cur) 1085 cur = old; 1086 return f->arr[cur]; 1087 } 1088 1089 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1090 { 1091 unsigned int cpu = smp_processor_id(); 1092 1093 return f->arr[cpu % num]; 1094 } 1095 1096 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1097 struct packet_type *pt, struct net_device *orig_dev) 1098 { 1099 struct packet_fanout *f = pt->af_packet_priv; 1100 unsigned int num = f->num_members; 1101 struct packet_sock *po; 1102 struct sock *sk; 1103 1104 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1105 !num) { 1106 kfree_skb(skb); 1107 return 0; 1108 } 1109 1110 switch (f->type) { 1111 case PACKET_FANOUT_HASH: 1112 default: 1113 if (f->defrag) { 1114 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1115 if (!skb) 1116 return 0; 1117 } 1118 skb_get_rxhash(skb); 1119 sk = fanout_demux_hash(f, skb, num); 1120 break; 1121 case PACKET_FANOUT_LB: 1122 sk = fanout_demux_lb(f, skb, num); 1123 break; 1124 case PACKET_FANOUT_CPU: 1125 sk = fanout_demux_cpu(f, skb, num); 1126 break; 1127 } 1128 1129 po = pkt_sk(sk); 1130 1131 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1132 } 1133 1134 DEFINE_MUTEX(fanout_mutex); 1135 EXPORT_SYMBOL_GPL(fanout_mutex); 1136 static LIST_HEAD(fanout_list); 1137 1138 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1139 { 1140 struct packet_fanout *f = po->fanout; 1141 1142 spin_lock(&f->lock); 1143 f->arr[f->num_members] = sk; 1144 smp_wmb(); 1145 f->num_members++; 1146 spin_unlock(&f->lock); 1147 } 1148 1149 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1150 { 1151 struct packet_fanout *f = po->fanout; 1152 int i; 1153 1154 spin_lock(&f->lock); 1155 for (i = 0; i < f->num_members; i++) { 1156 if (f->arr[i] == sk) 1157 break; 1158 } 1159 BUG_ON(i >= f->num_members); 1160 f->arr[i] = f->arr[f->num_members - 1]; 1161 f->num_members--; 1162 spin_unlock(&f->lock); 1163 } 1164 1165 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk) 1166 { 1167 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) 1168 return true; 1169 1170 return false; 1171 } 1172 1173 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1174 { 1175 struct packet_sock *po = pkt_sk(sk); 1176 struct packet_fanout *f, *match; 1177 u8 type = type_flags & 0xff; 1178 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; 1179 int err; 1180 1181 switch (type) { 1182 case PACKET_FANOUT_HASH: 1183 case PACKET_FANOUT_LB: 1184 case PACKET_FANOUT_CPU: 1185 break; 1186 default: 1187 return -EINVAL; 1188 } 1189 1190 if (!po->running) 1191 return -EINVAL; 1192 1193 if (po->fanout) 1194 return -EALREADY; 1195 1196 mutex_lock(&fanout_mutex); 1197 match = NULL; 1198 list_for_each_entry(f, &fanout_list, list) { 1199 if (f->id == id && 1200 read_pnet(&f->net) == sock_net(sk)) { 1201 match = f; 1202 break; 1203 } 1204 } 1205 err = -EINVAL; 1206 if (match && match->defrag != defrag) 1207 goto out; 1208 if (!match) { 1209 err = -ENOMEM; 1210 match = kzalloc(sizeof(*match), GFP_KERNEL); 1211 if (!match) 1212 goto out; 1213 write_pnet(&match->net, sock_net(sk)); 1214 match->id = id; 1215 match->type = type; 1216 match->defrag = defrag; 1217 atomic_set(&match->rr_cur, 0); 1218 INIT_LIST_HEAD(&match->list); 1219 spin_lock_init(&match->lock); 1220 atomic_set(&match->sk_ref, 0); 1221 match->prot_hook.type = po->prot_hook.type; 1222 match->prot_hook.dev = po->prot_hook.dev; 1223 match->prot_hook.func = packet_rcv_fanout; 1224 match->prot_hook.af_packet_priv = match; 1225 match->prot_hook.id_match = match_fanout_group; 1226 dev_add_pack(&match->prot_hook); 1227 list_add(&match->list, &fanout_list); 1228 } 1229 err = -EINVAL; 1230 if (match->type == type && 1231 match->prot_hook.type == po->prot_hook.type && 1232 match->prot_hook.dev == po->prot_hook.dev) { 1233 err = -ENOSPC; 1234 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1235 __dev_remove_pack(&po->prot_hook); 1236 po->fanout = match; 1237 atomic_inc(&match->sk_ref); 1238 __fanout_link(sk, po); 1239 err = 0; 1240 } 1241 } 1242 out: 1243 mutex_unlock(&fanout_mutex); 1244 return err; 1245 } 1246 1247 static void fanout_release(struct sock *sk) 1248 { 1249 struct packet_sock *po = pkt_sk(sk); 1250 struct packet_fanout *f; 1251 1252 f = po->fanout; 1253 if (!f) 1254 return; 1255 1256 mutex_lock(&fanout_mutex); 1257 po->fanout = NULL; 1258 1259 if (atomic_dec_and_test(&f->sk_ref)) { 1260 list_del(&f->list); 1261 dev_remove_pack(&f->prot_hook); 1262 kfree(f); 1263 } 1264 mutex_unlock(&fanout_mutex); 1265 } 1266 1267 static const struct proto_ops packet_ops; 1268 1269 static const struct proto_ops packet_ops_spkt; 1270 1271 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1272 struct packet_type *pt, struct net_device *orig_dev) 1273 { 1274 struct sock *sk; 1275 struct sockaddr_pkt *spkt; 1276 1277 /* 1278 * When we registered the protocol we saved the socket in the data 1279 * field for just this event. 1280 */ 1281 1282 sk = pt->af_packet_priv; 1283 1284 /* 1285 * Yank back the headers [hope the device set this 1286 * right or kerboom...] 1287 * 1288 * Incoming packets have ll header pulled, 1289 * push it back. 1290 * 1291 * For outgoing ones skb->data == skb_mac_header(skb) 1292 * so that this procedure is noop. 1293 */ 1294 1295 if (skb->pkt_type == PACKET_LOOPBACK) 1296 goto out; 1297 1298 if (!net_eq(dev_net(dev), sock_net(sk))) 1299 goto out; 1300 1301 skb = skb_share_check(skb, GFP_ATOMIC); 1302 if (skb == NULL) 1303 goto oom; 1304 1305 /* drop any routing info */ 1306 skb_dst_drop(skb); 1307 1308 /* drop conntrack reference */ 1309 nf_reset(skb); 1310 1311 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1312 1313 skb_push(skb, skb->data - skb_mac_header(skb)); 1314 1315 /* 1316 * The SOCK_PACKET socket receives _all_ frames. 1317 */ 1318 1319 spkt->spkt_family = dev->type; 1320 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1321 spkt->spkt_protocol = skb->protocol; 1322 1323 /* 1324 * Charge the memory to the socket. This is done specifically 1325 * to prevent sockets using all the memory up. 1326 */ 1327 1328 if (sock_queue_rcv_skb(sk, skb) == 0) 1329 return 0; 1330 1331 out: 1332 kfree_skb(skb); 1333 oom: 1334 return 0; 1335 } 1336 1337 1338 /* 1339 * Output a raw packet to a device layer. This bypasses all the other 1340 * protocol layers and you must therefore supply it with a complete frame 1341 */ 1342 1343 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1344 struct msghdr *msg, size_t len) 1345 { 1346 struct sock *sk = sock->sk; 1347 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1348 struct sk_buff *skb = NULL; 1349 struct net_device *dev; 1350 __be16 proto = 0; 1351 int err; 1352 int extra_len = 0; 1353 1354 /* 1355 * Get and verify the address. 1356 */ 1357 1358 if (saddr) { 1359 if (msg->msg_namelen < sizeof(struct sockaddr)) 1360 return -EINVAL; 1361 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1362 proto = saddr->spkt_protocol; 1363 } else 1364 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1365 1366 /* 1367 * Find the device first to size check it 1368 */ 1369 1370 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1371 retry: 1372 rcu_read_lock(); 1373 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1374 err = -ENODEV; 1375 if (dev == NULL) 1376 goto out_unlock; 1377 1378 err = -ENETDOWN; 1379 if (!(dev->flags & IFF_UP)) 1380 goto out_unlock; 1381 1382 /* 1383 * You may not queue a frame bigger than the mtu. This is the lowest level 1384 * raw protocol and you must do your own fragmentation at this level. 1385 */ 1386 1387 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1388 if (!netif_supports_nofcs(dev)) { 1389 err = -EPROTONOSUPPORT; 1390 goto out_unlock; 1391 } 1392 extra_len = 4; /* We're doing our own CRC */ 1393 } 1394 1395 err = -EMSGSIZE; 1396 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1397 goto out_unlock; 1398 1399 if (!skb) { 1400 size_t reserved = LL_RESERVED_SPACE(dev); 1401 int tlen = dev->needed_tailroom; 1402 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1403 1404 rcu_read_unlock(); 1405 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1406 if (skb == NULL) 1407 return -ENOBUFS; 1408 /* FIXME: Save some space for broken drivers that write a hard 1409 * header at transmission time by themselves. PPP is the notable 1410 * one here. This should really be fixed at the driver level. 1411 */ 1412 skb_reserve(skb, reserved); 1413 skb_reset_network_header(skb); 1414 1415 /* Try to align data part correctly */ 1416 if (hhlen) { 1417 skb->data -= hhlen; 1418 skb->tail -= hhlen; 1419 if (len < hhlen) 1420 skb_reset_network_header(skb); 1421 } 1422 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1423 if (err) 1424 goto out_free; 1425 goto retry; 1426 } 1427 1428 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1429 /* Earlier code assumed this would be a VLAN pkt, 1430 * double-check this now that we have the actual 1431 * packet in hand. 1432 */ 1433 struct ethhdr *ehdr; 1434 skb_reset_mac_header(skb); 1435 ehdr = eth_hdr(skb); 1436 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1437 err = -EMSGSIZE; 1438 goto out_unlock; 1439 } 1440 } 1441 1442 skb->protocol = proto; 1443 skb->dev = dev; 1444 skb->priority = sk->sk_priority; 1445 skb->mark = sk->sk_mark; 1446 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1447 if (err < 0) 1448 goto out_unlock; 1449 1450 if (unlikely(extra_len == 4)) 1451 skb->no_fcs = 1; 1452 1453 dev_queue_xmit(skb); 1454 rcu_read_unlock(); 1455 return len; 1456 1457 out_unlock: 1458 rcu_read_unlock(); 1459 out_free: 1460 kfree_skb(skb); 1461 return err; 1462 } 1463 1464 static unsigned int run_filter(const struct sk_buff *skb, 1465 const struct sock *sk, 1466 unsigned int res) 1467 { 1468 struct sk_filter *filter; 1469 1470 rcu_read_lock(); 1471 filter = rcu_dereference(sk->sk_filter); 1472 if (filter != NULL) 1473 res = SK_RUN_FILTER(filter, skb); 1474 rcu_read_unlock(); 1475 1476 return res; 1477 } 1478 1479 /* 1480 * This function makes lazy skb cloning in hope that most of packets 1481 * are discarded by BPF. 1482 * 1483 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1484 * and skb->cb are mangled. It works because (and until) packets 1485 * falling here are owned by current CPU. Output packets are cloned 1486 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1487 * sequencially, so that if we return skb to original state on exit, 1488 * we will not harm anyone. 1489 */ 1490 1491 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1492 struct packet_type *pt, struct net_device *orig_dev) 1493 { 1494 struct sock *sk; 1495 struct sockaddr_ll *sll; 1496 struct packet_sock *po; 1497 u8 *skb_head = skb->data; 1498 int skb_len = skb->len; 1499 unsigned int snaplen, res; 1500 1501 if (skb->pkt_type == PACKET_LOOPBACK) 1502 goto drop; 1503 1504 sk = pt->af_packet_priv; 1505 po = pkt_sk(sk); 1506 1507 if (!net_eq(dev_net(dev), sock_net(sk))) 1508 goto drop; 1509 1510 skb->dev = dev; 1511 1512 if (dev->header_ops) { 1513 /* The device has an explicit notion of ll header, 1514 * exported to higher levels. 1515 * 1516 * Otherwise, the device hides details of its frame 1517 * structure, so that corresponding packet head is 1518 * never delivered to user. 1519 */ 1520 if (sk->sk_type != SOCK_DGRAM) 1521 skb_push(skb, skb->data - skb_mac_header(skb)); 1522 else if (skb->pkt_type == PACKET_OUTGOING) { 1523 /* Special case: outgoing packets have ll header at head */ 1524 skb_pull(skb, skb_network_offset(skb)); 1525 } 1526 } 1527 1528 snaplen = skb->len; 1529 1530 res = run_filter(skb, sk, snaplen); 1531 if (!res) 1532 goto drop_n_restore; 1533 if (snaplen > res) 1534 snaplen = res; 1535 1536 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1537 goto drop_n_acct; 1538 1539 if (skb_shared(skb)) { 1540 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1541 if (nskb == NULL) 1542 goto drop_n_acct; 1543 1544 if (skb_head != skb->data) { 1545 skb->data = skb_head; 1546 skb->len = skb_len; 1547 } 1548 consume_skb(skb); 1549 skb = nskb; 1550 } 1551 1552 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1553 sizeof(skb->cb)); 1554 1555 sll = &PACKET_SKB_CB(skb)->sa.ll; 1556 sll->sll_family = AF_PACKET; 1557 sll->sll_hatype = dev->type; 1558 sll->sll_protocol = skb->protocol; 1559 sll->sll_pkttype = skb->pkt_type; 1560 if (unlikely(po->origdev)) 1561 sll->sll_ifindex = orig_dev->ifindex; 1562 else 1563 sll->sll_ifindex = dev->ifindex; 1564 1565 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1566 1567 PACKET_SKB_CB(skb)->origlen = skb->len; 1568 1569 if (pskb_trim(skb, snaplen)) 1570 goto drop_n_acct; 1571 1572 skb_set_owner_r(skb, sk); 1573 skb->dev = NULL; 1574 skb_dst_drop(skb); 1575 1576 /* drop conntrack reference */ 1577 nf_reset(skb); 1578 1579 spin_lock(&sk->sk_receive_queue.lock); 1580 po->stats.tp_packets++; 1581 skb->dropcount = atomic_read(&sk->sk_drops); 1582 __skb_queue_tail(&sk->sk_receive_queue, skb); 1583 spin_unlock(&sk->sk_receive_queue.lock); 1584 sk->sk_data_ready(sk, skb->len); 1585 return 0; 1586 1587 drop_n_acct: 1588 spin_lock(&sk->sk_receive_queue.lock); 1589 po->stats.tp_drops++; 1590 atomic_inc(&sk->sk_drops); 1591 spin_unlock(&sk->sk_receive_queue.lock); 1592 1593 drop_n_restore: 1594 if (skb_head != skb->data && skb_shared(skb)) { 1595 skb->data = skb_head; 1596 skb->len = skb_len; 1597 } 1598 drop: 1599 consume_skb(skb); 1600 return 0; 1601 } 1602 1603 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1604 struct packet_type *pt, struct net_device *orig_dev) 1605 { 1606 struct sock *sk; 1607 struct packet_sock *po; 1608 struct sockaddr_ll *sll; 1609 union { 1610 struct tpacket_hdr *h1; 1611 struct tpacket2_hdr *h2; 1612 struct tpacket3_hdr *h3; 1613 void *raw; 1614 } h; 1615 u8 *skb_head = skb->data; 1616 int skb_len = skb->len; 1617 unsigned int snaplen, res; 1618 unsigned long status = TP_STATUS_USER; 1619 unsigned short macoff, netoff, hdrlen; 1620 struct sk_buff *copy_skb = NULL; 1621 struct timeval tv; 1622 struct timespec ts; 1623 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 1624 1625 if (skb->pkt_type == PACKET_LOOPBACK) 1626 goto drop; 1627 1628 sk = pt->af_packet_priv; 1629 po = pkt_sk(sk); 1630 1631 if (!net_eq(dev_net(dev), sock_net(sk))) 1632 goto drop; 1633 1634 if (dev->header_ops) { 1635 if (sk->sk_type != SOCK_DGRAM) 1636 skb_push(skb, skb->data - skb_mac_header(skb)); 1637 else if (skb->pkt_type == PACKET_OUTGOING) { 1638 /* Special case: outgoing packets have ll header at head */ 1639 skb_pull(skb, skb_network_offset(skb)); 1640 } 1641 } 1642 1643 if (skb->ip_summed == CHECKSUM_PARTIAL) 1644 status |= TP_STATUS_CSUMNOTREADY; 1645 1646 snaplen = skb->len; 1647 1648 res = run_filter(skb, sk, snaplen); 1649 if (!res) 1650 goto drop_n_restore; 1651 if (snaplen > res) 1652 snaplen = res; 1653 1654 if (sk->sk_type == SOCK_DGRAM) { 1655 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1656 po->tp_reserve; 1657 } else { 1658 unsigned int maclen = skb_network_offset(skb); 1659 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1660 (maclen < 16 ? 16 : maclen)) + 1661 po->tp_reserve; 1662 macoff = netoff - maclen; 1663 } 1664 if (po->tp_version <= TPACKET_V2) { 1665 if (macoff + snaplen > po->rx_ring.frame_size) { 1666 if (po->copy_thresh && 1667 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1668 if (skb_shared(skb)) { 1669 copy_skb = skb_clone(skb, GFP_ATOMIC); 1670 } else { 1671 copy_skb = skb_get(skb); 1672 skb_head = skb->data; 1673 } 1674 if (copy_skb) 1675 skb_set_owner_r(copy_skb, sk); 1676 } 1677 snaplen = po->rx_ring.frame_size - macoff; 1678 if ((int)snaplen < 0) 1679 snaplen = 0; 1680 } 1681 } 1682 spin_lock(&sk->sk_receive_queue.lock); 1683 h.raw = packet_current_rx_frame(po, skb, 1684 TP_STATUS_KERNEL, (macoff+snaplen)); 1685 if (!h.raw) 1686 goto ring_is_full; 1687 if (po->tp_version <= TPACKET_V2) { 1688 packet_increment_rx_head(po, &po->rx_ring); 1689 /* 1690 * LOSING will be reported till you read the stats, 1691 * because it's COR - Clear On Read. 1692 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1693 * at packet level. 1694 */ 1695 if (po->stats.tp_drops) 1696 status |= TP_STATUS_LOSING; 1697 } 1698 po->stats.tp_packets++; 1699 if (copy_skb) { 1700 status |= TP_STATUS_COPY; 1701 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1702 } 1703 spin_unlock(&sk->sk_receive_queue.lock); 1704 1705 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1706 1707 switch (po->tp_version) { 1708 case TPACKET_V1: 1709 h.h1->tp_len = skb->len; 1710 h.h1->tp_snaplen = snaplen; 1711 h.h1->tp_mac = macoff; 1712 h.h1->tp_net = netoff; 1713 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1714 && shhwtstamps->syststamp.tv64) 1715 tv = ktime_to_timeval(shhwtstamps->syststamp); 1716 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1717 && shhwtstamps->hwtstamp.tv64) 1718 tv = ktime_to_timeval(shhwtstamps->hwtstamp); 1719 else if (skb->tstamp.tv64) 1720 tv = ktime_to_timeval(skb->tstamp); 1721 else 1722 do_gettimeofday(&tv); 1723 h.h1->tp_sec = tv.tv_sec; 1724 h.h1->tp_usec = tv.tv_usec; 1725 hdrlen = sizeof(*h.h1); 1726 break; 1727 case TPACKET_V2: 1728 h.h2->tp_len = skb->len; 1729 h.h2->tp_snaplen = snaplen; 1730 h.h2->tp_mac = macoff; 1731 h.h2->tp_net = netoff; 1732 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1733 && shhwtstamps->syststamp.tv64) 1734 ts = ktime_to_timespec(shhwtstamps->syststamp); 1735 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1736 && shhwtstamps->hwtstamp.tv64) 1737 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1738 else if (skb->tstamp.tv64) 1739 ts = ktime_to_timespec(skb->tstamp); 1740 else 1741 getnstimeofday(&ts); 1742 h.h2->tp_sec = ts.tv_sec; 1743 h.h2->tp_nsec = ts.tv_nsec; 1744 if (vlan_tx_tag_present(skb)) { 1745 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1746 status |= TP_STATUS_VLAN_VALID; 1747 } else { 1748 h.h2->tp_vlan_tci = 0; 1749 } 1750 h.h2->tp_padding = 0; 1751 hdrlen = sizeof(*h.h2); 1752 break; 1753 case TPACKET_V3: 1754 /* tp_nxt_offset,vlan are already populated above. 1755 * So DONT clear those fields here 1756 */ 1757 h.h3->tp_status |= status; 1758 h.h3->tp_len = skb->len; 1759 h.h3->tp_snaplen = snaplen; 1760 h.h3->tp_mac = macoff; 1761 h.h3->tp_net = netoff; 1762 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1763 && shhwtstamps->syststamp.tv64) 1764 ts = ktime_to_timespec(shhwtstamps->syststamp); 1765 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1766 && shhwtstamps->hwtstamp.tv64) 1767 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1768 else if (skb->tstamp.tv64) 1769 ts = ktime_to_timespec(skb->tstamp); 1770 else 1771 getnstimeofday(&ts); 1772 h.h3->tp_sec = ts.tv_sec; 1773 h.h3->tp_nsec = ts.tv_nsec; 1774 hdrlen = sizeof(*h.h3); 1775 break; 1776 default: 1777 BUG(); 1778 } 1779 1780 sll = h.raw + TPACKET_ALIGN(hdrlen); 1781 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1782 sll->sll_family = AF_PACKET; 1783 sll->sll_hatype = dev->type; 1784 sll->sll_protocol = skb->protocol; 1785 sll->sll_pkttype = skb->pkt_type; 1786 if (unlikely(po->origdev)) 1787 sll->sll_ifindex = orig_dev->ifindex; 1788 else 1789 sll->sll_ifindex = dev->ifindex; 1790 1791 smp_mb(); 1792 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1793 { 1794 u8 *start, *end; 1795 1796 if (po->tp_version <= TPACKET_V2) { 1797 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1798 + macoff + snaplen); 1799 for (start = h.raw; start < end; start += PAGE_SIZE) 1800 flush_dcache_page(pgv_to_page(start)); 1801 } 1802 smp_wmb(); 1803 } 1804 #endif 1805 if (po->tp_version <= TPACKET_V2) 1806 __packet_set_status(po, h.raw, status); 1807 else 1808 prb_clear_blk_fill_status(&po->rx_ring); 1809 1810 sk->sk_data_ready(sk, 0); 1811 1812 drop_n_restore: 1813 if (skb_head != skb->data && skb_shared(skb)) { 1814 skb->data = skb_head; 1815 skb->len = skb_len; 1816 } 1817 drop: 1818 kfree_skb(skb); 1819 return 0; 1820 1821 ring_is_full: 1822 po->stats.tp_drops++; 1823 spin_unlock(&sk->sk_receive_queue.lock); 1824 1825 sk->sk_data_ready(sk, 0); 1826 kfree_skb(copy_skb); 1827 goto drop_n_restore; 1828 } 1829 1830 static void tpacket_destruct_skb(struct sk_buff *skb) 1831 { 1832 struct packet_sock *po = pkt_sk(skb->sk); 1833 void *ph; 1834 1835 if (likely(po->tx_ring.pg_vec)) { 1836 ph = skb_shinfo(skb)->destructor_arg; 1837 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1838 atomic_dec(&po->tx_ring.pending); 1839 __packet_set_status(po, ph, TP_STATUS_AVAILABLE); 1840 } 1841 1842 sock_wfree(skb); 1843 } 1844 1845 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1846 void *frame, struct net_device *dev, int size_max, 1847 __be16 proto, unsigned char *addr, int hlen) 1848 { 1849 union { 1850 struct tpacket_hdr *h1; 1851 struct tpacket2_hdr *h2; 1852 void *raw; 1853 } ph; 1854 int to_write, offset, len, tp_len, nr_frags, len_max; 1855 struct socket *sock = po->sk.sk_socket; 1856 struct page *page; 1857 void *data; 1858 int err; 1859 1860 ph.raw = frame; 1861 1862 skb->protocol = proto; 1863 skb->dev = dev; 1864 skb->priority = po->sk.sk_priority; 1865 skb->mark = po->sk.sk_mark; 1866 skb_shinfo(skb)->destructor_arg = ph.raw; 1867 1868 switch (po->tp_version) { 1869 case TPACKET_V2: 1870 tp_len = ph.h2->tp_len; 1871 break; 1872 default: 1873 tp_len = ph.h1->tp_len; 1874 break; 1875 } 1876 if (unlikely(tp_len > size_max)) { 1877 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1878 return -EMSGSIZE; 1879 } 1880 1881 skb_reserve(skb, hlen); 1882 skb_reset_network_header(skb); 1883 1884 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1885 to_write = tp_len; 1886 1887 if (sock->type == SOCK_DGRAM) { 1888 err = dev_hard_header(skb, dev, ntohs(proto), addr, 1889 NULL, tp_len); 1890 if (unlikely(err < 0)) 1891 return -EINVAL; 1892 } else if (dev->hard_header_len) { 1893 /* net device doesn't like empty head */ 1894 if (unlikely(tp_len <= dev->hard_header_len)) { 1895 pr_err("packet size is too short (%d < %d)\n", 1896 tp_len, dev->hard_header_len); 1897 return -EINVAL; 1898 } 1899 1900 skb_push(skb, dev->hard_header_len); 1901 err = skb_store_bits(skb, 0, data, 1902 dev->hard_header_len); 1903 if (unlikely(err)) 1904 return err; 1905 1906 data += dev->hard_header_len; 1907 to_write -= dev->hard_header_len; 1908 } 1909 1910 err = -EFAULT; 1911 offset = offset_in_page(data); 1912 len_max = PAGE_SIZE - offset; 1913 len = ((to_write > len_max) ? len_max : to_write); 1914 1915 skb->data_len = to_write; 1916 skb->len += to_write; 1917 skb->truesize += to_write; 1918 atomic_add(to_write, &po->sk.sk_wmem_alloc); 1919 1920 while (likely(to_write)) { 1921 nr_frags = skb_shinfo(skb)->nr_frags; 1922 1923 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 1924 pr_err("Packet exceed the number of skb frags(%lu)\n", 1925 MAX_SKB_FRAGS); 1926 return -EFAULT; 1927 } 1928 1929 page = pgv_to_page(data); 1930 data += len; 1931 flush_dcache_page(page); 1932 get_page(page); 1933 skb_fill_page_desc(skb, nr_frags, page, offset, len); 1934 to_write -= len; 1935 offset = 0; 1936 len_max = PAGE_SIZE; 1937 len = ((to_write > len_max) ? len_max : to_write); 1938 } 1939 1940 return tp_len; 1941 } 1942 1943 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 1944 { 1945 struct sk_buff *skb; 1946 struct net_device *dev; 1947 __be16 proto; 1948 bool need_rls_dev = false; 1949 int err, reserve = 0; 1950 void *ph; 1951 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 1952 int tp_len, size_max; 1953 unsigned char *addr; 1954 int len_sum = 0; 1955 int status = TP_STATUS_AVAILABLE; 1956 int hlen, tlen; 1957 1958 mutex_lock(&po->pg_vec_lock); 1959 1960 err = -EBUSY; 1961 if (saddr == NULL) { 1962 dev = po->prot_hook.dev; 1963 proto = po->num; 1964 addr = NULL; 1965 } else { 1966 err = -EINVAL; 1967 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 1968 goto out; 1969 if (msg->msg_namelen < (saddr->sll_halen 1970 + offsetof(struct sockaddr_ll, 1971 sll_addr))) 1972 goto out; 1973 proto = saddr->sll_protocol; 1974 addr = saddr->sll_addr; 1975 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 1976 need_rls_dev = true; 1977 } 1978 1979 err = -ENXIO; 1980 if (unlikely(dev == NULL)) 1981 goto out; 1982 1983 reserve = dev->hard_header_len; 1984 1985 err = -ENETDOWN; 1986 if (unlikely(!(dev->flags & IFF_UP))) 1987 goto out_put; 1988 1989 size_max = po->tx_ring.frame_size 1990 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 1991 1992 if (size_max > dev->mtu + reserve) 1993 size_max = dev->mtu + reserve; 1994 1995 do { 1996 ph = packet_current_frame(po, &po->tx_ring, 1997 TP_STATUS_SEND_REQUEST); 1998 1999 if (unlikely(ph == NULL)) { 2000 schedule(); 2001 continue; 2002 } 2003 2004 status = TP_STATUS_SEND_REQUEST; 2005 hlen = LL_RESERVED_SPACE(dev); 2006 tlen = dev->needed_tailroom; 2007 skb = sock_alloc_send_skb(&po->sk, 2008 hlen + tlen + sizeof(struct sockaddr_ll), 2009 0, &err); 2010 2011 if (unlikely(skb == NULL)) 2012 goto out_status; 2013 2014 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2015 addr, hlen); 2016 2017 if (unlikely(tp_len < 0)) { 2018 if (po->tp_loss) { 2019 __packet_set_status(po, ph, 2020 TP_STATUS_AVAILABLE); 2021 packet_increment_head(&po->tx_ring); 2022 kfree_skb(skb); 2023 continue; 2024 } else { 2025 status = TP_STATUS_WRONG_FORMAT; 2026 err = tp_len; 2027 goto out_status; 2028 } 2029 } 2030 2031 skb->destructor = tpacket_destruct_skb; 2032 __packet_set_status(po, ph, TP_STATUS_SENDING); 2033 atomic_inc(&po->tx_ring.pending); 2034 2035 status = TP_STATUS_SEND_REQUEST; 2036 err = dev_queue_xmit(skb); 2037 if (unlikely(err > 0)) { 2038 err = net_xmit_errno(err); 2039 if (err && __packet_get_status(po, ph) == 2040 TP_STATUS_AVAILABLE) { 2041 /* skb was destructed already */ 2042 skb = NULL; 2043 goto out_status; 2044 } 2045 /* 2046 * skb was dropped but not destructed yet; 2047 * let's treat it like congestion or err < 0 2048 */ 2049 err = 0; 2050 } 2051 packet_increment_head(&po->tx_ring); 2052 len_sum += tp_len; 2053 } while (likely((ph != NULL) || 2054 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2055 (atomic_read(&po->tx_ring.pending)))) 2056 ); 2057 2058 err = len_sum; 2059 goto out_put; 2060 2061 out_status: 2062 __packet_set_status(po, ph, status); 2063 kfree_skb(skb); 2064 out_put: 2065 if (need_rls_dev) 2066 dev_put(dev); 2067 out: 2068 mutex_unlock(&po->pg_vec_lock); 2069 return err; 2070 } 2071 2072 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2073 size_t reserve, size_t len, 2074 size_t linear, int noblock, 2075 int *err) 2076 { 2077 struct sk_buff *skb; 2078 2079 /* Under a page? Don't bother with paged skb. */ 2080 if (prepad + len < PAGE_SIZE || !linear) 2081 linear = len; 2082 2083 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2084 err); 2085 if (!skb) 2086 return NULL; 2087 2088 skb_reserve(skb, reserve); 2089 skb_put(skb, linear); 2090 skb->data_len = len - linear; 2091 skb->len += len - linear; 2092 2093 return skb; 2094 } 2095 2096 static int packet_snd(struct socket *sock, 2097 struct msghdr *msg, size_t len) 2098 { 2099 struct sock *sk = sock->sk; 2100 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2101 struct sk_buff *skb; 2102 struct net_device *dev; 2103 __be16 proto; 2104 bool need_rls_dev = false; 2105 unsigned char *addr; 2106 int err, reserve = 0; 2107 struct virtio_net_hdr vnet_hdr = { 0 }; 2108 int offset = 0; 2109 int vnet_hdr_len; 2110 struct packet_sock *po = pkt_sk(sk); 2111 unsigned short gso_type = 0; 2112 int hlen, tlen; 2113 int extra_len = 0; 2114 2115 /* 2116 * Get and verify the address. 2117 */ 2118 2119 if (saddr == NULL) { 2120 dev = po->prot_hook.dev; 2121 proto = po->num; 2122 addr = NULL; 2123 } else { 2124 err = -EINVAL; 2125 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2126 goto out; 2127 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2128 goto out; 2129 proto = saddr->sll_protocol; 2130 addr = saddr->sll_addr; 2131 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2132 need_rls_dev = true; 2133 } 2134 2135 err = -ENXIO; 2136 if (dev == NULL) 2137 goto out_unlock; 2138 if (sock->type == SOCK_RAW) 2139 reserve = dev->hard_header_len; 2140 2141 err = -ENETDOWN; 2142 if (!(dev->flags & IFF_UP)) 2143 goto out_unlock; 2144 2145 if (po->has_vnet_hdr) { 2146 vnet_hdr_len = sizeof(vnet_hdr); 2147 2148 err = -EINVAL; 2149 if (len < vnet_hdr_len) 2150 goto out_unlock; 2151 2152 len -= vnet_hdr_len; 2153 2154 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2155 vnet_hdr_len); 2156 if (err < 0) 2157 goto out_unlock; 2158 2159 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2160 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2161 vnet_hdr.hdr_len)) 2162 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2163 vnet_hdr.csum_offset + 2; 2164 2165 err = -EINVAL; 2166 if (vnet_hdr.hdr_len > len) 2167 goto out_unlock; 2168 2169 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2170 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2171 case VIRTIO_NET_HDR_GSO_TCPV4: 2172 gso_type = SKB_GSO_TCPV4; 2173 break; 2174 case VIRTIO_NET_HDR_GSO_TCPV6: 2175 gso_type = SKB_GSO_TCPV6; 2176 break; 2177 case VIRTIO_NET_HDR_GSO_UDP: 2178 gso_type = SKB_GSO_UDP; 2179 break; 2180 default: 2181 goto out_unlock; 2182 } 2183 2184 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2185 gso_type |= SKB_GSO_TCP_ECN; 2186 2187 if (vnet_hdr.gso_size == 0) 2188 goto out_unlock; 2189 2190 } 2191 } 2192 2193 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2194 if (!netif_supports_nofcs(dev)) { 2195 err = -EPROTONOSUPPORT; 2196 goto out_unlock; 2197 } 2198 extra_len = 4; /* We're doing our own CRC */ 2199 } 2200 2201 err = -EMSGSIZE; 2202 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2203 goto out_unlock; 2204 2205 err = -ENOBUFS; 2206 hlen = LL_RESERVED_SPACE(dev); 2207 tlen = dev->needed_tailroom; 2208 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2209 msg->msg_flags & MSG_DONTWAIT, &err); 2210 if (skb == NULL) 2211 goto out_unlock; 2212 2213 skb_set_network_header(skb, reserve); 2214 2215 err = -EINVAL; 2216 if (sock->type == SOCK_DGRAM && 2217 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2218 goto out_free; 2219 2220 /* Returns -EFAULT on error */ 2221 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2222 if (err) 2223 goto out_free; 2224 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2225 if (err < 0) 2226 goto out_free; 2227 2228 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2229 /* Earlier code assumed this would be a VLAN pkt, 2230 * double-check this now that we have the actual 2231 * packet in hand. 2232 */ 2233 struct ethhdr *ehdr; 2234 skb_reset_mac_header(skb); 2235 ehdr = eth_hdr(skb); 2236 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2237 err = -EMSGSIZE; 2238 goto out_free; 2239 } 2240 } 2241 2242 skb->protocol = proto; 2243 skb->dev = dev; 2244 skb->priority = sk->sk_priority; 2245 skb->mark = sk->sk_mark; 2246 2247 if (po->has_vnet_hdr) { 2248 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2249 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2250 vnet_hdr.csum_offset)) { 2251 err = -EINVAL; 2252 goto out_free; 2253 } 2254 } 2255 2256 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2257 skb_shinfo(skb)->gso_type = gso_type; 2258 2259 /* Header must be checked, and gso_segs computed. */ 2260 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2261 skb_shinfo(skb)->gso_segs = 0; 2262 2263 len += vnet_hdr_len; 2264 } 2265 2266 if (unlikely(extra_len == 4)) 2267 skb->no_fcs = 1; 2268 2269 /* 2270 * Now send it 2271 */ 2272 2273 err = dev_queue_xmit(skb); 2274 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2275 goto out_unlock; 2276 2277 if (need_rls_dev) 2278 dev_put(dev); 2279 2280 return len; 2281 2282 out_free: 2283 kfree_skb(skb); 2284 out_unlock: 2285 if (dev && need_rls_dev) 2286 dev_put(dev); 2287 out: 2288 return err; 2289 } 2290 2291 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2292 struct msghdr *msg, size_t len) 2293 { 2294 struct sock *sk = sock->sk; 2295 struct packet_sock *po = pkt_sk(sk); 2296 if (po->tx_ring.pg_vec) 2297 return tpacket_snd(po, msg); 2298 else 2299 return packet_snd(sock, msg, len); 2300 } 2301 2302 /* 2303 * Close a PACKET socket. This is fairly simple. We immediately go 2304 * to 'closed' state and remove our protocol entry in the device list. 2305 */ 2306 2307 static int packet_release(struct socket *sock) 2308 { 2309 struct sock *sk = sock->sk; 2310 struct packet_sock *po; 2311 struct net *net; 2312 union tpacket_req_u req_u; 2313 2314 if (!sk) 2315 return 0; 2316 2317 net = sock_net(sk); 2318 po = pkt_sk(sk); 2319 2320 mutex_lock(&net->packet.sklist_lock); 2321 sk_del_node_init_rcu(sk); 2322 mutex_unlock(&net->packet.sklist_lock); 2323 2324 preempt_disable(); 2325 sock_prot_inuse_add(net, sk->sk_prot, -1); 2326 preempt_enable(); 2327 2328 spin_lock(&po->bind_lock); 2329 unregister_prot_hook(sk, false); 2330 if (po->prot_hook.dev) { 2331 dev_put(po->prot_hook.dev); 2332 po->prot_hook.dev = NULL; 2333 } 2334 spin_unlock(&po->bind_lock); 2335 2336 packet_flush_mclist(sk); 2337 2338 memset(&req_u, 0, sizeof(req_u)); 2339 2340 if (po->rx_ring.pg_vec) 2341 packet_set_ring(sk, &req_u, 1, 0); 2342 2343 if (po->tx_ring.pg_vec) 2344 packet_set_ring(sk, &req_u, 1, 1); 2345 2346 fanout_release(sk); 2347 2348 synchronize_net(); 2349 /* 2350 * Now the socket is dead. No more input will appear. 2351 */ 2352 sock_orphan(sk); 2353 sock->sk = NULL; 2354 2355 /* Purge queues */ 2356 2357 skb_queue_purge(&sk->sk_receive_queue); 2358 sk_refcnt_debug_release(sk); 2359 2360 sock_put(sk); 2361 return 0; 2362 } 2363 2364 /* 2365 * Attach a packet hook. 2366 */ 2367 2368 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2369 { 2370 struct packet_sock *po = pkt_sk(sk); 2371 2372 if (po->fanout) { 2373 if (dev) 2374 dev_put(dev); 2375 2376 return -EINVAL; 2377 } 2378 2379 lock_sock(sk); 2380 2381 spin_lock(&po->bind_lock); 2382 unregister_prot_hook(sk, true); 2383 po->num = protocol; 2384 po->prot_hook.type = protocol; 2385 if (po->prot_hook.dev) 2386 dev_put(po->prot_hook.dev); 2387 po->prot_hook.dev = dev; 2388 2389 po->ifindex = dev ? dev->ifindex : 0; 2390 2391 if (protocol == 0) 2392 goto out_unlock; 2393 2394 if (!dev || (dev->flags & IFF_UP)) { 2395 register_prot_hook(sk); 2396 } else { 2397 sk->sk_err = ENETDOWN; 2398 if (!sock_flag(sk, SOCK_DEAD)) 2399 sk->sk_error_report(sk); 2400 } 2401 2402 out_unlock: 2403 spin_unlock(&po->bind_lock); 2404 release_sock(sk); 2405 return 0; 2406 } 2407 2408 /* 2409 * Bind a packet socket to a device 2410 */ 2411 2412 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2413 int addr_len) 2414 { 2415 struct sock *sk = sock->sk; 2416 char name[15]; 2417 struct net_device *dev; 2418 int err = -ENODEV; 2419 2420 /* 2421 * Check legality 2422 */ 2423 2424 if (addr_len != sizeof(struct sockaddr)) 2425 return -EINVAL; 2426 strlcpy(name, uaddr->sa_data, sizeof(name)); 2427 2428 dev = dev_get_by_name(sock_net(sk), name); 2429 if (dev) 2430 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2431 return err; 2432 } 2433 2434 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2435 { 2436 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2437 struct sock *sk = sock->sk; 2438 struct net_device *dev = NULL; 2439 int err; 2440 2441 2442 /* 2443 * Check legality 2444 */ 2445 2446 if (addr_len < sizeof(struct sockaddr_ll)) 2447 return -EINVAL; 2448 if (sll->sll_family != AF_PACKET) 2449 return -EINVAL; 2450 2451 if (sll->sll_ifindex) { 2452 err = -ENODEV; 2453 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2454 if (dev == NULL) 2455 goto out; 2456 } 2457 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2458 2459 out: 2460 return err; 2461 } 2462 2463 static struct proto packet_proto = { 2464 .name = "PACKET", 2465 .owner = THIS_MODULE, 2466 .obj_size = sizeof(struct packet_sock), 2467 }; 2468 2469 /* 2470 * Create a packet of type SOCK_PACKET. 2471 */ 2472 2473 static int packet_create(struct net *net, struct socket *sock, int protocol, 2474 int kern) 2475 { 2476 struct sock *sk; 2477 struct packet_sock *po; 2478 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2479 int err; 2480 2481 if (!capable(CAP_NET_RAW)) 2482 return -EPERM; 2483 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2484 sock->type != SOCK_PACKET) 2485 return -ESOCKTNOSUPPORT; 2486 2487 sock->state = SS_UNCONNECTED; 2488 2489 err = -ENOBUFS; 2490 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2491 if (sk == NULL) 2492 goto out; 2493 2494 sock->ops = &packet_ops; 2495 if (sock->type == SOCK_PACKET) 2496 sock->ops = &packet_ops_spkt; 2497 2498 sock_init_data(sock, sk); 2499 2500 po = pkt_sk(sk); 2501 sk->sk_family = PF_PACKET; 2502 po->num = proto; 2503 2504 sk->sk_destruct = packet_sock_destruct; 2505 sk_refcnt_debug_inc(sk); 2506 2507 /* 2508 * Attach a protocol block 2509 */ 2510 2511 spin_lock_init(&po->bind_lock); 2512 mutex_init(&po->pg_vec_lock); 2513 po->prot_hook.func = packet_rcv; 2514 2515 if (sock->type == SOCK_PACKET) 2516 po->prot_hook.func = packet_rcv_spkt; 2517 2518 po->prot_hook.af_packet_priv = sk; 2519 2520 if (proto) { 2521 po->prot_hook.type = proto; 2522 register_prot_hook(sk); 2523 } 2524 2525 mutex_lock(&net->packet.sklist_lock); 2526 sk_add_node_rcu(sk, &net->packet.sklist); 2527 mutex_unlock(&net->packet.sklist_lock); 2528 2529 preempt_disable(); 2530 sock_prot_inuse_add(net, &packet_proto, 1); 2531 preempt_enable(); 2532 2533 return 0; 2534 out: 2535 return err; 2536 } 2537 2538 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2539 { 2540 struct sock_exterr_skb *serr; 2541 struct sk_buff *skb, *skb2; 2542 int copied, err; 2543 2544 err = -EAGAIN; 2545 skb = skb_dequeue(&sk->sk_error_queue); 2546 if (skb == NULL) 2547 goto out; 2548 2549 copied = skb->len; 2550 if (copied > len) { 2551 msg->msg_flags |= MSG_TRUNC; 2552 copied = len; 2553 } 2554 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2555 if (err) 2556 goto out_free_skb; 2557 2558 sock_recv_timestamp(msg, sk, skb); 2559 2560 serr = SKB_EXT_ERR(skb); 2561 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2562 sizeof(serr->ee), &serr->ee); 2563 2564 msg->msg_flags |= MSG_ERRQUEUE; 2565 err = copied; 2566 2567 /* Reset and regenerate socket error */ 2568 spin_lock_bh(&sk->sk_error_queue.lock); 2569 sk->sk_err = 0; 2570 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2571 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2572 spin_unlock_bh(&sk->sk_error_queue.lock); 2573 sk->sk_error_report(sk); 2574 } else 2575 spin_unlock_bh(&sk->sk_error_queue.lock); 2576 2577 out_free_skb: 2578 kfree_skb(skb); 2579 out: 2580 return err; 2581 } 2582 2583 /* 2584 * Pull a packet from our receive queue and hand it to the user. 2585 * If necessary we block. 2586 */ 2587 2588 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2589 struct msghdr *msg, size_t len, int flags) 2590 { 2591 struct sock *sk = sock->sk; 2592 struct sk_buff *skb; 2593 int copied, err; 2594 struct sockaddr_ll *sll; 2595 int vnet_hdr_len = 0; 2596 2597 err = -EINVAL; 2598 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2599 goto out; 2600 2601 #if 0 2602 /* What error should we return now? EUNATTACH? */ 2603 if (pkt_sk(sk)->ifindex < 0) 2604 return -ENODEV; 2605 #endif 2606 2607 if (flags & MSG_ERRQUEUE) { 2608 err = packet_recv_error(sk, msg, len); 2609 goto out; 2610 } 2611 2612 /* 2613 * Call the generic datagram receiver. This handles all sorts 2614 * of horrible races and re-entrancy so we can forget about it 2615 * in the protocol layers. 2616 * 2617 * Now it will return ENETDOWN, if device have just gone down, 2618 * but then it will block. 2619 */ 2620 2621 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2622 2623 /* 2624 * An error occurred so return it. Because skb_recv_datagram() 2625 * handles the blocking we don't see and worry about blocking 2626 * retries. 2627 */ 2628 2629 if (skb == NULL) 2630 goto out; 2631 2632 if (pkt_sk(sk)->has_vnet_hdr) { 2633 struct virtio_net_hdr vnet_hdr = { 0 }; 2634 2635 err = -EINVAL; 2636 vnet_hdr_len = sizeof(vnet_hdr); 2637 if (len < vnet_hdr_len) 2638 goto out_free; 2639 2640 len -= vnet_hdr_len; 2641 2642 if (skb_is_gso(skb)) { 2643 struct skb_shared_info *sinfo = skb_shinfo(skb); 2644 2645 /* This is a hint as to how much should be linear. */ 2646 vnet_hdr.hdr_len = skb_headlen(skb); 2647 vnet_hdr.gso_size = sinfo->gso_size; 2648 if (sinfo->gso_type & SKB_GSO_TCPV4) 2649 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2650 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2651 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2652 else if (sinfo->gso_type & SKB_GSO_UDP) 2653 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2654 else if (sinfo->gso_type & SKB_GSO_FCOE) 2655 goto out_free; 2656 else 2657 BUG(); 2658 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2659 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2660 } else 2661 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2662 2663 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2664 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2665 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2666 vnet_hdr.csum_offset = skb->csum_offset; 2667 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2668 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2669 } /* else everything is zero */ 2670 2671 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2672 vnet_hdr_len); 2673 if (err < 0) 2674 goto out_free; 2675 } 2676 2677 /* 2678 * If the address length field is there to be filled in, we fill 2679 * it in now. 2680 */ 2681 2682 sll = &PACKET_SKB_CB(skb)->sa.ll; 2683 if (sock->type == SOCK_PACKET) 2684 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2685 else 2686 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2687 2688 /* 2689 * You lose any data beyond the buffer you gave. If it worries a 2690 * user program they can ask the device for its MTU anyway. 2691 */ 2692 2693 copied = skb->len; 2694 if (copied > len) { 2695 copied = len; 2696 msg->msg_flags |= MSG_TRUNC; 2697 } 2698 2699 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2700 if (err) 2701 goto out_free; 2702 2703 sock_recv_ts_and_drops(msg, sk, skb); 2704 2705 if (msg->msg_name) 2706 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2707 msg->msg_namelen); 2708 2709 if (pkt_sk(sk)->auxdata) { 2710 struct tpacket_auxdata aux; 2711 2712 aux.tp_status = TP_STATUS_USER; 2713 if (skb->ip_summed == CHECKSUM_PARTIAL) 2714 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2715 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2716 aux.tp_snaplen = skb->len; 2717 aux.tp_mac = 0; 2718 aux.tp_net = skb_network_offset(skb); 2719 if (vlan_tx_tag_present(skb)) { 2720 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2721 aux.tp_status |= TP_STATUS_VLAN_VALID; 2722 } else { 2723 aux.tp_vlan_tci = 0; 2724 } 2725 aux.tp_padding = 0; 2726 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2727 } 2728 2729 /* 2730 * Free or return the buffer as appropriate. Again this 2731 * hides all the races and re-entrancy issues from us. 2732 */ 2733 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2734 2735 out_free: 2736 skb_free_datagram(sk, skb); 2737 out: 2738 return err; 2739 } 2740 2741 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2742 int *uaddr_len, int peer) 2743 { 2744 struct net_device *dev; 2745 struct sock *sk = sock->sk; 2746 2747 if (peer) 2748 return -EOPNOTSUPP; 2749 2750 uaddr->sa_family = AF_PACKET; 2751 rcu_read_lock(); 2752 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2753 if (dev) 2754 strncpy(uaddr->sa_data, dev->name, 14); 2755 else 2756 memset(uaddr->sa_data, 0, 14); 2757 rcu_read_unlock(); 2758 *uaddr_len = sizeof(*uaddr); 2759 2760 return 0; 2761 } 2762 2763 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2764 int *uaddr_len, int peer) 2765 { 2766 struct net_device *dev; 2767 struct sock *sk = sock->sk; 2768 struct packet_sock *po = pkt_sk(sk); 2769 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2770 2771 if (peer) 2772 return -EOPNOTSUPP; 2773 2774 sll->sll_family = AF_PACKET; 2775 sll->sll_ifindex = po->ifindex; 2776 sll->sll_protocol = po->num; 2777 sll->sll_pkttype = 0; 2778 rcu_read_lock(); 2779 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2780 if (dev) { 2781 sll->sll_hatype = dev->type; 2782 sll->sll_halen = dev->addr_len; 2783 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2784 } else { 2785 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2786 sll->sll_halen = 0; 2787 } 2788 rcu_read_unlock(); 2789 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2790 2791 return 0; 2792 } 2793 2794 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2795 int what) 2796 { 2797 switch (i->type) { 2798 case PACKET_MR_MULTICAST: 2799 if (i->alen != dev->addr_len) 2800 return -EINVAL; 2801 if (what > 0) 2802 return dev_mc_add(dev, i->addr); 2803 else 2804 return dev_mc_del(dev, i->addr); 2805 break; 2806 case PACKET_MR_PROMISC: 2807 return dev_set_promiscuity(dev, what); 2808 break; 2809 case PACKET_MR_ALLMULTI: 2810 return dev_set_allmulti(dev, what); 2811 break; 2812 case PACKET_MR_UNICAST: 2813 if (i->alen != dev->addr_len) 2814 return -EINVAL; 2815 if (what > 0) 2816 return dev_uc_add(dev, i->addr); 2817 else 2818 return dev_uc_del(dev, i->addr); 2819 break; 2820 default: 2821 break; 2822 } 2823 return 0; 2824 } 2825 2826 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2827 { 2828 for ( ; i; i = i->next) { 2829 if (i->ifindex == dev->ifindex) 2830 packet_dev_mc(dev, i, what); 2831 } 2832 } 2833 2834 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2835 { 2836 struct packet_sock *po = pkt_sk(sk); 2837 struct packet_mclist *ml, *i; 2838 struct net_device *dev; 2839 int err; 2840 2841 rtnl_lock(); 2842 2843 err = -ENODEV; 2844 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2845 if (!dev) 2846 goto done; 2847 2848 err = -EINVAL; 2849 if (mreq->mr_alen > dev->addr_len) 2850 goto done; 2851 2852 err = -ENOBUFS; 2853 i = kmalloc(sizeof(*i), GFP_KERNEL); 2854 if (i == NULL) 2855 goto done; 2856 2857 err = 0; 2858 for (ml = po->mclist; ml; ml = ml->next) { 2859 if (ml->ifindex == mreq->mr_ifindex && 2860 ml->type == mreq->mr_type && 2861 ml->alen == mreq->mr_alen && 2862 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2863 ml->count++; 2864 /* Free the new element ... */ 2865 kfree(i); 2866 goto done; 2867 } 2868 } 2869 2870 i->type = mreq->mr_type; 2871 i->ifindex = mreq->mr_ifindex; 2872 i->alen = mreq->mr_alen; 2873 memcpy(i->addr, mreq->mr_address, i->alen); 2874 i->count = 1; 2875 i->next = po->mclist; 2876 po->mclist = i; 2877 err = packet_dev_mc(dev, i, 1); 2878 if (err) { 2879 po->mclist = i->next; 2880 kfree(i); 2881 } 2882 2883 done: 2884 rtnl_unlock(); 2885 return err; 2886 } 2887 2888 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2889 { 2890 struct packet_mclist *ml, **mlp; 2891 2892 rtnl_lock(); 2893 2894 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 2895 if (ml->ifindex == mreq->mr_ifindex && 2896 ml->type == mreq->mr_type && 2897 ml->alen == mreq->mr_alen && 2898 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2899 if (--ml->count == 0) { 2900 struct net_device *dev; 2901 *mlp = ml->next; 2902 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 2903 if (dev) 2904 packet_dev_mc(dev, ml, -1); 2905 kfree(ml); 2906 } 2907 rtnl_unlock(); 2908 return 0; 2909 } 2910 } 2911 rtnl_unlock(); 2912 return -EADDRNOTAVAIL; 2913 } 2914 2915 static void packet_flush_mclist(struct sock *sk) 2916 { 2917 struct packet_sock *po = pkt_sk(sk); 2918 struct packet_mclist *ml; 2919 2920 if (!po->mclist) 2921 return; 2922 2923 rtnl_lock(); 2924 while ((ml = po->mclist) != NULL) { 2925 struct net_device *dev; 2926 2927 po->mclist = ml->next; 2928 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 2929 if (dev != NULL) 2930 packet_dev_mc(dev, ml, -1); 2931 kfree(ml); 2932 } 2933 rtnl_unlock(); 2934 } 2935 2936 static int 2937 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 2938 { 2939 struct sock *sk = sock->sk; 2940 struct packet_sock *po = pkt_sk(sk); 2941 int ret; 2942 2943 if (level != SOL_PACKET) 2944 return -ENOPROTOOPT; 2945 2946 switch (optname) { 2947 case PACKET_ADD_MEMBERSHIP: 2948 case PACKET_DROP_MEMBERSHIP: 2949 { 2950 struct packet_mreq_max mreq; 2951 int len = optlen; 2952 memset(&mreq, 0, sizeof(mreq)); 2953 if (len < sizeof(struct packet_mreq)) 2954 return -EINVAL; 2955 if (len > sizeof(mreq)) 2956 len = sizeof(mreq); 2957 if (copy_from_user(&mreq, optval, len)) 2958 return -EFAULT; 2959 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 2960 return -EINVAL; 2961 if (optname == PACKET_ADD_MEMBERSHIP) 2962 ret = packet_mc_add(sk, &mreq); 2963 else 2964 ret = packet_mc_drop(sk, &mreq); 2965 return ret; 2966 } 2967 2968 case PACKET_RX_RING: 2969 case PACKET_TX_RING: 2970 { 2971 union tpacket_req_u req_u; 2972 int len; 2973 2974 switch (po->tp_version) { 2975 case TPACKET_V1: 2976 case TPACKET_V2: 2977 len = sizeof(req_u.req); 2978 break; 2979 case TPACKET_V3: 2980 default: 2981 len = sizeof(req_u.req3); 2982 break; 2983 } 2984 if (optlen < len) 2985 return -EINVAL; 2986 if (pkt_sk(sk)->has_vnet_hdr) 2987 return -EINVAL; 2988 if (copy_from_user(&req_u.req, optval, len)) 2989 return -EFAULT; 2990 return packet_set_ring(sk, &req_u, 0, 2991 optname == PACKET_TX_RING); 2992 } 2993 case PACKET_COPY_THRESH: 2994 { 2995 int val; 2996 2997 if (optlen != sizeof(val)) 2998 return -EINVAL; 2999 if (copy_from_user(&val, optval, sizeof(val))) 3000 return -EFAULT; 3001 3002 pkt_sk(sk)->copy_thresh = val; 3003 return 0; 3004 } 3005 case PACKET_VERSION: 3006 { 3007 int val; 3008 3009 if (optlen != sizeof(val)) 3010 return -EINVAL; 3011 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3012 return -EBUSY; 3013 if (copy_from_user(&val, optval, sizeof(val))) 3014 return -EFAULT; 3015 switch (val) { 3016 case TPACKET_V1: 3017 case TPACKET_V2: 3018 case TPACKET_V3: 3019 po->tp_version = val; 3020 return 0; 3021 default: 3022 return -EINVAL; 3023 } 3024 } 3025 case PACKET_RESERVE: 3026 { 3027 unsigned int val; 3028 3029 if (optlen != sizeof(val)) 3030 return -EINVAL; 3031 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3032 return -EBUSY; 3033 if (copy_from_user(&val, optval, sizeof(val))) 3034 return -EFAULT; 3035 po->tp_reserve = val; 3036 return 0; 3037 } 3038 case PACKET_LOSS: 3039 { 3040 unsigned int val; 3041 3042 if (optlen != sizeof(val)) 3043 return -EINVAL; 3044 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3045 return -EBUSY; 3046 if (copy_from_user(&val, optval, sizeof(val))) 3047 return -EFAULT; 3048 po->tp_loss = !!val; 3049 return 0; 3050 } 3051 case PACKET_AUXDATA: 3052 { 3053 int val; 3054 3055 if (optlen < sizeof(val)) 3056 return -EINVAL; 3057 if (copy_from_user(&val, optval, sizeof(val))) 3058 return -EFAULT; 3059 3060 po->auxdata = !!val; 3061 return 0; 3062 } 3063 case PACKET_ORIGDEV: 3064 { 3065 int val; 3066 3067 if (optlen < sizeof(val)) 3068 return -EINVAL; 3069 if (copy_from_user(&val, optval, sizeof(val))) 3070 return -EFAULT; 3071 3072 po->origdev = !!val; 3073 return 0; 3074 } 3075 case PACKET_VNET_HDR: 3076 { 3077 int val; 3078 3079 if (sock->type != SOCK_RAW) 3080 return -EINVAL; 3081 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3082 return -EBUSY; 3083 if (optlen < sizeof(val)) 3084 return -EINVAL; 3085 if (copy_from_user(&val, optval, sizeof(val))) 3086 return -EFAULT; 3087 3088 po->has_vnet_hdr = !!val; 3089 return 0; 3090 } 3091 case PACKET_TIMESTAMP: 3092 { 3093 int val; 3094 3095 if (optlen != sizeof(val)) 3096 return -EINVAL; 3097 if (copy_from_user(&val, optval, sizeof(val))) 3098 return -EFAULT; 3099 3100 po->tp_tstamp = val; 3101 return 0; 3102 } 3103 case PACKET_FANOUT: 3104 { 3105 int val; 3106 3107 if (optlen != sizeof(val)) 3108 return -EINVAL; 3109 if (copy_from_user(&val, optval, sizeof(val))) 3110 return -EFAULT; 3111 3112 return fanout_add(sk, val & 0xffff, val >> 16); 3113 } 3114 default: 3115 return -ENOPROTOOPT; 3116 } 3117 } 3118 3119 static int packet_getsockopt(struct socket *sock, int level, int optname, 3120 char __user *optval, int __user *optlen) 3121 { 3122 int len; 3123 int val, lv = sizeof(val); 3124 struct sock *sk = sock->sk; 3125 struct packet_sock *po = pkt_sk(sk); 3126 void *data = &val; 3127 struct tpacket_stats st; 3128 union tpacket_stats_u st_u; 3129 3130 if (level != SOL_PACKET) 3131 return -ENOPROTOOPT; 3132 3133 if (get_user(len, optlen)) 3134 return -EFAULT; 3135 3136 if (len < 0) 3137 return -EINVAL; 3138 3139 switch (optname) { 3140 case PACKET_STATISTICS: 3141 spin_lock_bh(&sk->sk_receive_queue.lock); 3142 if (po->tp_version == TPACKET_V3) { 3143 lv = sizeof(struct tpacket_stats_v3); 3144 memcpy(&st_u.stats3, &po->stats, 3145 sizeof(struct tpacket_stats)); 3146 st_u.stats3.tp_freeze_q_cnt = 3147 po->stats_u.stats3.tp_freeze_q_cnt; 3148 st_u.stats3.tp_packets += po->stats.tp_drops; 3149 data = &st_u.stats3; 3150 } else { 3151 lv = sizeof(struct tpacket_stats); 3152 st = po->stats; 3153 st.tp_packets += st.tp_drops; 3154 data = &st; 3155 } 3156 memset(&po->stats, 0, sizeof(st)); 3157 spin_unlock_bh(&sk->sk_receive_queue.lock); 3158 break; 3159 case PACKET_AUXDATA: 3160 val = po->auxdata; 3161 break; 3162 case PACKET_ORIGDEV: 3163 val = po->origdev; 3164 break; 3165 case PACKET_VNET_HDR: 3166 val = po->has_vnet_hdr; 3167 break; 3168 case PACKET_VERSION: 3169 val = po->tp_version; 3170 break; 3171 case PACKET_HDRLEN: 3172 if (len > sizeof(int)) 3173 len = sizeof(int); 3174 if (copy_from_user(&val, optval, len)) 3175 return -EFAULT; 3176 switch (val) { 3177 case TPACKET_V1: 3178 val = sizeof(struct tpacket_hdr); 3179 break; 3180 case TPACKET_V2: 3181 val = sizeof(struct tpacket2_hdr); 3182 break; 3183 case TPACKET_V3: 3184 val = sizeof(struct tpacket3_hdr); 3185 break; 3186 default: 3187 return -EINVAL; 3188 } 3189 break; 3190 case PACKET_RESERVE: 3191 val = po->tp_reserve; 3192 break; 3193 case PACKET_LOSS: 3194 val = po->tp_loss; 3195 break; 3196 case PACKET_TIMESTAMP: 3197 val = po->tp_tstamp; 3198 break; 3199 case PACKET_FANOUT: 3200 val = (po->fanout ? 3201 ((u32)po->fanout->id | 3202 ((u32)po->fanout->type << 16)) : 3203 0); 3204 break; 3205 default: 3206 return -ENOPROTOOPT; 3207 } 3208 3209 if (len > lv) 3210 len = lv; 3211 if (put_user(len, optlen)) 3212 return -EFAULT; 3213 if (copy_to_user(optval, data, len)) 3214 return -EFAULT; 3215 return 0; 3216 } 3217 3218 3219 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3220 { 3221 struct sock *sk; 3222 struct hlist_node *node; 3223 struct net_device *dev = data; 3224 struct net *net = dev_net(dev); 3225 3226 rcu_read_lock(); 3227 sk_for_each_rcu(sk, node, &net->packet.sklist) { 3228 struct packet_sock *po = pkt_sk(sk); 3229 3230 switch (msg) { 3231 case NETDEV_UNREGISTER: 3232 if (po->mclist) 3233 packet_dev_mclist(dev, po->mclist, -1); 3234 /* fallthrough */ 3235 3236 case NETDEV_DOWN: 3237 if (dev->ifindex == po->ifindex) { 3238 spin_lock(&po->bind_lock); 3239 if (po->running) { 3240 __unregister_prot_hook(sk, false); 3241 sk->sk_err = ENETDOWN; 3242 if (!sock_flag(sk, SOCK_DEAD)) 3243 sk->sk_error_report(sk); 3244 } 3245 if (msg == NETDEV_UNREGISTER) { 3246 po->ifindex = -1; 3247 if (po->prot_hook.dev) 3248 dev_put(po->prot_hook.dev); 3249 po->prot_hook.dev = NULL; 3250 } 3251 spin_unlock(&po->bind_lock); 3252 } 3253 break; 3254 case NETDEV_UP: 3255 if (dev->ifindex == po->ifindex) { 3256 spin_lock(&po->bind_lock); 3257 if (po->num) 3258 register_prot_hook(sk); 3259 spin_unlock(&po->bind_lock); 3260 } 3261 break; 3262 } 3263 } 3264 rcu_read_unlock(); 3265 return NOTIFY_DONE; 3266 } 3267 3268 3269 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3270 unsigned long arg) 3271 { 3272 struct sock *sk = sock->sk; 3273 3274 switch (cmd) { 3275 case SIOCOUTQ: 3276 { 3277 int amount = sk_wmem_alloc_get(sk); 3278 3279 return put_user(amount, (int __user *)arg); 3280 } 3281 case SIOCINQ: 3282 { 3283 struct sk_buff *skb; 3284 int amount = 0; 3285 3286 spin_lock_bh(&sk->sk_receive_queue.lock); 3287 skb = skb_peek(&sk->sk_receive_queue); 3288 if (skb) 3289 amount = skb->len; 3290 spin_unlock_bh(&sk->sk_receive_queue.lock); 3291 return put_user(amount, (int __user *)arg); 3292 } 3293 case SIOCGSTAMP: 3294 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3295 case SIOCGSTAMPNS: 3296 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3297 3298 #ifdef CONFIG_INET 3299 case SIOCADDRT: 3300 case SIOCDELRT: 3301 case SIOCDARP: 3302 case SIOCGARP: 3303 case SIOCSARP: 3304 case SIOCGIFADDR: 3305 case SIOCSIFADDR: 3306 case SIOCGIFBRDADDR: 3307 case SIOCSIFBRDADDR: 3308 case SIOCGIFNETMASK: 3309 case SIOCSIFNETMASK: 3310 case SIOCGIFDSTADDR: 3311 case SIOCSIFDSTADDR: 3312 case SIOCSIFFLAGS: 3313 return inet_dgram_ops.ioctl(sock, cmd, arg); 3314 #endif 3315 3316 default: 3317 return -ENOIOCTLCMD; 3318 } 3319 return 0; 3320 } 3321 3322 static unsigned int packet_poll(struct file *file, struct socket *sock, 3323 poll_table *wait) 3324 { 3325 struct sock *sk = sock->sk; 3326 struct packet_sock *po = pkt_sk(sk); 3327 unsigned int mask = datagram_poll(file, sock, wait); 3328 3329 spin_lock_bh(&sk->sk_receive_queue.lock); 3330 if (po->rx_ring.pg_vec) { 3331 if (!packet_previous_rx_frame(po, &po->rx_ring, 3332 TP_STATUS_KERNEL)) 3333 mask |= POLLIN | POLLRDNORM; 3334 } 3335 spin_unlock_bh(&sk->sk_receive_queue.lock); 3336 spin_lock_bh(&sk->sk_write_queue.lock); 3337 if (po->tx_ring.pg_vec) { 3338 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3339 mask |= POLLOUT | POLLWRNORM; 3340 } 3341 spin_unlock_bh(&sk->sk_write_queue.lock); 3342 return mask; 3343 } 3344 3345 3346 /* Dirty? Well, I still did not learn better way to account 3347 * for user mmaps. 3348 */ 3349 3350 static void packet_mm_open(struct vm_area_struct *vma) 3351 { 3352 struct file *file = vma->vm_file; 3353 struct socket *sock = file->private_data; 3354 struct sock *sk = sock->sk; 3355 3356 if (sk) 3357 atomic_inc(&pkt_sk(sk)->mapped); 3358 } 3359 3360 static void packet_mm_close(struct vm_area_struct *vma) 3361 { 3362 struct file *file = vma->vm_file; 3363 struct socket *sock = file->private_data; 3364 struct sock *sk = sock->sk; 3365 3366 if (sk) 3367 atomic_dec(&pkt_sk(sk)->mapped); 3368 } 3369 3370 static const struct vm_operations_struct packet_mmap_ops = { 3371 .open = packet_mm_open, 3372 .close = packet_mm_close, 3373 }; 3374 3375 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3376 unsigned int len) 3377 { 3378 int i; 3379 3380 for (i = 0; i < len; i++) { 3381 if (likely(pg_vec[i].buffer)) { 3382 if (is_vmalloc_addr(pg_vec[i].buffer)) 3383 vfree(pg_vec[i].buffer); 3384 else 3385 free_pages((unsigned long)pg_vec[i].buffer, 3386 order); 3387 pg_vec[i].buffer = NULL; 3388 } 3389 } 3390 kfree(pg_vec); 3391 } 3392 3393 static char *alloc_one_pg_vec_page(unsigned long order) 3394 { 3395 char *buffer = NULL; 3396 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3397 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3398 3399 buffer = (char *) __get_free_pages(gfp_flags, order); 3400 3401 if (buffer) 3402 return buffer; 3403 3404 /* 3405 * __get_free_pages failed, fall back to vmalloc 3406 */ 3407 buffer = vzalloc((1 << order) * PAGE_SIZE); 3408 3409 if (buffer) 3410 return buffer; 3411 3412 /* 3413 * vmalloc failed, lets dig into swap here 3414 */ 3415 gfp_flags &= ~__GFP_NORETRY; 3416 buffer = (char *)__get_free_pages(gfp_flags, order); 3417 if (buffer) 3418 return buffer; 3419 3420 /* 3421 * complete and utter failure 3422 */ 3423 return NULL; 3424 } 3425 3426 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3427 { 3428 unsigned int block_nr = req->tp_block_nr; 3429 struct pgv *pg_vec; 3430 int i; 3431 3432 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3433 if (unlikely(!pg_vec)) 3434 goto out; 3435 3436 for (i = 0; i < block_nr; i++) { 3437 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3438 if (unlikely(!pg_vec[i].buffer)) 3439 goto out_free_pgvec; 3440 } 3441 3442 out: 3443 return pg_vec; 3444 3445 out_free_pgvec: 3446 free_pg_vec(pg_vec, order, block_nr); 3447 pg_vec = NULL; 3448 goto out; 3449 } 3450 3451 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3452 int closing, int tx_ring) 3453 { 3454 struct pgv *pg_vec = NULL; 3455 struct packet_sock *po = pkt_sk(sk); 3456 int was_running, order = 0; 3457 struct packet_ring_buffer *rb; 3458 struct sk_buff_head *rb_queue; 3459 __be16 num; 3460 int err = -EINVAL; 3461 /* Added to avoid minimal code churn */ 3462 struct tpacket_req *req = &req_u->req; 3463 3464 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3465 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3466 WARN(1, "Tx-ring is not supported.\n"); 3467 goto out; 3468 } 3469 3470 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3471 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3472 3473 err = -EBUSY; 3474 if (!closing) { 3475 if (atomic_read(&po->mapped)) 3476 goto out; 3477 if (atomic_read(&rb->pending)) 3478 goto out; 3479 } 3480 3481 if (req->tp_block_nr) { 3482 /* Sanity tests and some calculations */ 3483 err = -EBUSY; 3484 if (unlikely(rb->pg_vec)) 3485 goto out; 3486 3487 switch (po->tp_version) { 3488 case TPACKET_V1: 3489 po->tp_hdrlen = TPACKET_HDRLEN; 3490 break; 3491 case TPACKET_V2: 3492 po->tp_hdrlen = TPACKET2_HDRLEN; 3493 break; 3494 case TPACKET_V3: 3495 po->tp_hdrlen = TPACKET3_HDRLEN; 3496 break; 3497 } 3498 3499 err = -EINVAL; 3500 if (unlikely((int)req->tp_block_size <= 0)) 3501 goto out; 3502 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3503 goto out; 3504 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3505 po->tp_reserve)) 3506 goto out; 3507 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3508 goto out; 3509 3510 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3511 if (unlikely(rb->frames_per_block <= 0)) 3512 goto out; 3513 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3514 req->tp_frame_nr)) 3515 goto out; 3516 3517 err = -ENOMEM; 3518 order = get_order(req->tp_block_size); 3519 pg_vec = alloc_pg_vec(req, order); 3520 if (unlikely(!pg_vec)) 3521 goto out; 3522 switch (po->tp_version) { 3523 case TPACKET_V3: 3524 /* Transmit path is not supported. We checked 3525 * it above but just being paranoid 3526 */ 3527 if (!tx_ring) 3528 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3529 break; 3530 default: 3531 break; 3532 } 3533 } 3534 /* Done */ 3535 else { 3536 err = -EINVAL; 3537 if (unlikely(req->tp_frame_nr)) 3538 goto out; 3539 } 3540 3541 lock_sock(sk); 3542 3543 /* Detach socket from network */ 3544 spin_lock(&po->bind_lock); 3545 was_running = po->running; 3546 num = po->num; 3547 if (was_running) { 3548 po->num = 0; 3549 __unregister_prot_hook(sk, false); 3550 } 3551 spin_unlock(&po->bind_lock); 3552 3553 synchronize_net(); 3554 3555 err = -EBUSY; 3556 mutex_lock(&po->pg_vec_lock); 3557 if (closing || atomic_read(&po->mapped) == 0) { 3558 err = 0; 3559 spin_lock_bh(&rb_queue->lock); 3560 swap(rb->pg_vec, pg_vec); 3561 rb->frame_max = (req->tp_frame_nr - 1); 3562 rb->head = 0; 3563 rb->frame_size = req->tp_frame_size; 3564 spin_unlock_bh(&rb_queue->lock); 3565 3566 swap(rb->pg_vec_order, order); 3567 swap(rb->pg_vec_len, req->tp_block_nr); 3568 3569 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3570 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3571 tpacket_rcv : packet_rcv; 3572 skb_queue_purge(rb_queue); 3573 if (atomic_read(&po->mapped)) 3574 pr_err("packet_mmap: vma is busy: %d\n", 3575 atomic_read(&po->mapped)); 3576 } 3577 mutex_unlock(&po->pg_vec_lock); 3578 3579 spin_lock(&po->bind_lock); 3580 if (was_running) { 3581 po->num = num; 3582 register_prot_hook(sk); 3583 } 3584 spin_unlock(&po->bind_lock); 3585 if (closing && (po->tp_version > TPACKET_V2)) { 3586 /* Because we don't support block-based V3 on tx-ring */ 3587 if (!tx_ring) 3588 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3589 } 3590 release_sock(sk); 3591 3592 if (pg_vec) 3593 free_pg_vec(pg_vec, order, req->tp_block_nr); 3594 out: 3595 return err; 3596 } 3597 3598 static int packet_mmap(struct file *file, struct socket *sock, 3599 struct vm_area_struct *vma) 3600 { 3601 struct sock *sk = sock->sk; 3602 struct packet_sock *po = pkt_sk(sk); 3603 unsigned long size, expected_size; 3604 struct packet_ring_buffer *rb; 3605 unsigned long start; 3606 int err = -EINVAL; 3607 int i; 3608 3609 if (vma->vm_pgoff) 3610 return -EINVAL; 3611 3612 mutex_lock(&po->pg_vec_lock); 3613 3614 expected_size = 0; 3615 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3616 if (rb->pg_vec) { 3617 expected_size += rb->pg_vec_len 3618 * rb->pg_vec_pages 3619 * PAGE_SIZE; 3620 } 3621 } 3622 3623 if (expected_size == 0) 3624 goto out; 3625 3626 size = vma->vm_end - vma->vm_start; 3627 if (size != expected_size) 3628 goto out; 3629 3630 start = vma->vm_start; 3631 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3632 if (rb->pg_vec == NULL) 3633 continue; 3634 3635 for (i = 0; i < rb->pg_vec_len; i++) { 3636 struct page *page; 3637 void *kaddr = rb->pg_vec[i].buffer; 3638 int pg_num; 3639 3640 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3641 page = pgv_to_page(kaddr); 3642 err = vm_insert_page(vma, start, page); 3643 if (unlikely(err)) 3644 goto out; 3645 start += PAGE_SIZE; 3646 kaddr += PAGE_SIZE; 3647 } 3648 } 3649 } 3650 3651 atomic_inc(&po->mapped); 3652 vma->vm_ops = &packet_mmap_ops; 3653 err = 0; 3654 3655 out: 3656 mutex_unlock(&po->pg_vec_lock); 3657 return err; 3658 } 3659 3660 static const struct proto_ops packet_ops_spkt = { 3661 .family = PF_PACKET, 3662 .owner = THIS_MODULE, 3663 .release = packet_release, 3664 .bind = packet_bind_spkt, 3665 .connect = sock_no_connect, 3666 .socketpair = sock_no_socketpair, 3667 .accept = sock_no_accept, 3668 .getname = packet_getname_spkt, 3669 .poll = datagram_poll, 3670 .ioctl = packet_ioctl, 3671 .listen = sock_no_listen, 3672 .shutdown = sock_no_shutdown, 3673 .setsockopt = sock_no_setsockopt, 3674 .getsockopt = sock_no_getsockopt, 3675 .sendmsg = packet_sendmsg_spkt, 3676 .recvmsg = packet_recvmsg, 3677 .mmap = sock_no_mmap, 3678 .sendpage = sock_no_sendpage, 3679 }; 3680 3681 static const struct proto_ops packet_ops = { 3682 .family = PF_PACKET, 3683 .owner = THIS_MODULE, 3684 .release = packet_release, 3685 .bind = packet_bind, 3686 .connect = sock_no_connect, 3687 .socketpair = sock_no_socketpair, 3688 .accept = sock_no_accept, 3689 .getname = packet_getname, 3690 .poll = packet_poll, 3691 .ioctl = packet_ioctl, 3692 .listen = sock_no_listen, 3693 .shutdown = sock_no_shutdown, 3694 .setsockopt = packet_setsockopt, 3695 .getsockopt = packet_getsockopt, 3696 .sendmsg = packet_sendmsg, 3697 .recvmsg = packet_recvmsg, 3698 .mmap = packet_mmap, 3699 .sendpage = sock_no_sendpage, 3700 }; 3701 3702 static const struct net_proto_family packet_family_ops = { 3703 .family = PF_PACKET, 3704 .create = packet_create, 3705 .owner = THIS_MODULE, 3706 }; 3707 3708 static struct notifier_block packet_netdev_notifier = { 3709 .notifier_call = packet_notifier, 3710 }; 3711 3712 #ifdef CONFIG_PROC_FS 3713 3714 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3715 __acquires(RCU) 3716 { 3717 struct net *net = seq_file_net(seq); 3718 3719 rcu_read_lock(); 3720 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3721 } 3722 3723 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3724 { 3725 struct net *net = seq_file_net(seq); 3726 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3727 } 3728 3729 static void packet_seq_stop(struct seq_file *seq, void *v) 3730 __releases(RCU) 3731 { 3732 rcu_read_unlock(); 3733 } 3734 3735 static int packet_seq_show(struct seq_file *seq, void *v) 3736 { 3737 if (v == SEQ_START_TOKEN) 3738 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3739 else { 3740 struct sock *s = sk_entry(v); 3741 const struct packet_sock *po = pkt_sk(s); 3742 3743 seq_printf(seq, 3744 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3745 s, 3746 atomic_read(&s->sk_refcnt), 3747 s->sk_type, 3748 ntohs(po->num), 3749 po->ifindex, 3750 po->running, 3751 atomic_read(&s->sk_rmem_alloc), 3752 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 3753 sock_i_ino(s)); 3754 } 3755 3756 return 0; 3757 } 3758 3759 static const struct seq_operations packet_seq_ops = { 3760 .start = packet_seq_start, 3761 .next = packet_seq_next, 3762 .stop = packet_seq_stop, 3763 .show = packet_seq_show, 3764 }; 3765 3766 static int packet_seq_open(struct inode *inode, struct file *file) 3767 { 3768 return seq_open_net(inode, file, &packet_seq_ops, 3769 sizeof(struct seq_net_private)); 3770 } 3771 3772 static const struct file_operations packet_seq_fops = { 3773 .owner = THIS_MODULE, 3774 .open = packet_seq_open, 3775 .read = seq_read, 3776 .llseek = seq_lseek, 3777 .release = seq_release_net, 3778 }; 3779 3780 #endif 3781 3782 static int __net_init packet_net_init(struct net *net) 3783 { 3784 mutex_init(&net->packet.sklist_lock); 3785 INIT_HLIST_HEAD(&net->packet.sklist); 3786 3787 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops)) 3788 return -ENOMEM; 3789 3790 return 0; 3791 } 3792 3793 static void __net_exit packet_net_exit(struct net *net) 3794 { 3795 proc_net_remove(net, "packet"); 3796 } 3797 3798 static struct pernet_operations packet_net_ops = { 3799 .init = packet_net_init, 3800 .exit = packet_net_exit, 3801 }; 3802 3803 3804 static void __exit packet_exit(void) 3805 { 3806 unregister_netdevice_notifier(&packet_netdev_notifier); 3807 unregister_pernet_subsys(&packet_net_ops); 3808 sock_unregister(PF_PACKET); 3809 proto_unregister(&packet_proto); 3810 } 3811 3812 static int __init packet_init(void) 3813 { 3814 int rc = proto_register(&packet_proto, 0); 3815 3816 if (rc != 0) 3817 goto out; 3818 3819 sock_register(&packet_family_ops); 3820 register_pernet_subsys(&packet_net_ops); 3821 register_netdevice_notifier(&packet_netdev_notifier); 3822 out: 3823 return rc; 3824 } 3825 3826 module_init(packet_init); 3827 module_exit(packet_exit); 3828 MODULE_LICENSE("GPL"); 3829 MODULE_ALIAS_NETPROTO(PF_PACKET); 3830