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 union tpacket_uhdr { 162 struct tpacket_hdr *h1; 163 struct tpacket2_hdr *h2; 164 struct tpacket3_hdr *h3; 165 void *raw; 166 }; 167 168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 169 int closing, int tx_ring); 170 171 #define V3_ALIGNMENT (8) 172 173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 174 175 #define BLK_PLUS_PRIV(sz_of_priv) \ 176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 177 178 #define PGV_FROM_VMALLOC 1 179 180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 187 188 struct packet_sock; 189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 191 struct packet_type *pt, struct net_device *orig_dev); 192 193 static void *packet_previous_frame(struct packet_sock *po, 194 struct packet_ring_buffer *rb, 195 int status); 196 static void packet_increment_head(struct packet_ring_buffer *buff); 197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 198 struct tpacket_block_desc *); 199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 200 struct packet_sock *); 201 static void prb_retire_current_block(struct tpacket_kbdq_core *, 202 struct packet_sock *, unsigned int status); 203 static int prb_queue_frozen(struct tpacket_kbdq_core *); 204 static void prb_open_block(struct tpacket_kbdq_core *, 205 struct tpacket_block_desc *); 206 static void prb_retire_rx_blk_timer_expired(unsigned long); 207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 208 static void prb_init_blk_timer(struct packet_sock *, 209 struct tpacket_kbdq_core *, 210 void (*func) (unsigned long)); 211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 212 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 213 struct tpacket3_hdr *); 214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 215 struct tpacket3_hdr *); 216 static void packet_flush_mclist(struct sock *sk); 217 218 struct packet_skb_cb { 219 unsigned int origlen; 220 union { 221 struct sockaddr_pkt pkt; 222 struct sockaddr_ll ll; 223 } sa; 224 }; 225 226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 227 228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 229 #define GET_PBLOCK_DESC(x, bid) \ 230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 233 #define GET_NEXT_PRB_BLK_NUM(x) \ 234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 235 ((x)->kactive_blk_num+1) : 0) 236 237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 238 static void __fanout_link(struct sock *sk, struct packet_sock *po); 239 240 /* register_prot_hook must be invoked with the po->bind_lock held, 241 * or from a context in which asynchronous accesses to the packet 242 * socket is not possible (packet_create()). 243 */ 244 static void register_prot_hook(struct sock *sk) 245 { 246 struct packet_sock *po = pkt_sk(sk); 247 if (!po->running) { 248 if (po->fanout) 249 __fanout_link(sk, po); 250 else 251 dev_add_pack(&po->prot_hook); 252 sock_hold(sk); 253 po->running = 1; 254 } 255 } 256 257 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 258 * held. If the sync parameter is true, we will temporarily drop 259 * the po->bind_lock and do a synchronize_net to make sure no 260 * asynchronous packet processing paths still refer to the elements 261 * of po->prot_hook. If the sync parameter is false, it is the 262 * callers responsibility to take care of this. 263 */ 264 static void __unregister_prot_hook(struct sock *sk, bool sync) 265 { 266 struct packet_sock *po = pkt_sk(sk); 267 268 po->running = 0; 269 if (po->fanout) 270 __fanout_unlink(sk, po); 271 else 272 __dev_remove_pack(&po->prot_hook); 273 __sock_put(sk); 274 275 if (sync) { 276 spin_unlock(&po->bind_lock); 277 synchronize_net(); 278 spin_lock(&po->bind_lock); 279 } 280 } 281 282 static void unregister_prot_hook(struct sock *sk, bool sync) 283 { 284 struct packet_sock *po = pkt_sk(sk); 285 286 if (po->running) 287 __unregister_prot_hook(sk, sync); 288 } 289 290 static inline __pure struct page *pgv_to_page(void *addr) 291 { 292 if (is_vmalloc_addr(addr)) 293 return vmalloc_to_page(addr); 294 return virt_to_page(addr); 295 } 296 297 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 298 { 299 union tpacket_uhdr h; 300 301 h.raw = frame; 302 switch (po->tp_version) { 303 case TPACKET_V1: 304 h.h1->tp_status = status; 305 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 306 break; 307 case TPACKET_V2: 308 h.h2->tp_status = status; 309 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 310 break; 311 case TPACKET_V3: 312 default: 313 WARN(1, "TPACKET version not supported.\n"); 314 BUG(); 315 } 316 317 smp_wmb(); 318 } 319 320 static int __packet_get_status(struct packet_sock *po, void *frame) 321 { 322 union tpacket_uhdr 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 __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 343 unsigned int flags) 344 { 345 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 346 347 if (shhwtstamps) { 348 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) && 349 ktime_to_timespec_cond(shhwtstamps->syststamp, ts)) 350 return TP_STATUS_TS_SYS_HARDWARE; 351 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 352 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 353 return TP_STATUS_TS_RAW_HARDWARE; 354 } 355 356 if (ktime_to_timespec_cond(skb->tstamp, ts)) 357 return TP_STATUS_TS_SOFTWARE; 358 359 return 0; 360 } 361 362 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 363 struct sk_buff *skb) 364 { 365 union tpacket_uhdr h; 366 struct timespec ts; 367 __u32 ts_status; 368 369 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 370 return 0; 371 372 h.raw = frame; 373 switch (po->tp_version) { 374 case TPACKET_V1: 375 h.h1->tp_sec = ts.tv_sec; 376 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 377 break; 378 case TPACKET_V2: 379 h.h2->tp_sec = ts.tv_sec; 380 h.h2->tp_nsec = ts.tv_nsec; 381 break; 382 case TPACKET_V3: 383 default: 384 WARN(1, "TPACKET version not supported.\n"); 385 BUG(); 386 } 387 388 /* one flush is safe, as both fields always lie on the same cacheline */ 389 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 390 smp_wmb(); 391 392 return ts_status; 393 } 394 395 static void *packet_lookup_frame(struct packet_sock *po, 396 struct packet_ring_buffer *rb, 397 unsigned int position, 398 int status) 399 { 400 unsigned int pg_vec_pos, frame_offset; 401 union tpacket_uhdr h; 402 403 pg_vec_pos = position / rb->frames_per_block; 404 frame_offset = position % rb->frames_per_block; 405 406 h.raw = rb->pg_vec[pg_vec_pos].buffer + 407 (frame_offset * rb->frame_size); 408 409 if (status != __packet_get_status(po, h.raw)) 410 return NULL; 411 412 return h.raw; 413 } 414 415 static void *packet_current_frame(struct packet_sock *po, 416 struct packet_ring_buffer *rb, 417 int status) 418 { 419 return packet_lookup_frame(po, rb, rb->head, status); 420 } 421 422 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 423 { 424 del_timer_sync(&pkc->retire_blk_timer); 425 } 426 427 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 428 int tx_ring, 429 struct sk_buff_head *rb_queue) 430 { 431 struct tpacket_kbdq_core *pkc; 432 433 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 434 435 spin_lock(&rb_queue->lock); 436 pkc->delete_blk_timer = 1; 437 spin_unlock(&rb_queue->lock); 438 439 prb_del_retire_blk_timer(pkc); 440 } 441 442 static void prb_init_blk_timer(struct packet_sock *po, 443 struct tpacket_kbdq_core *pkc, 444 void (*func) (unsigned long)) 445 { 446 init_timer(&pkc->retire_blk_timer); 447 pkc->retire_blk_timer.data = (long)po; 448 pkc->retire_blk_timer.function = func; 449 pkc->retire_blk_timer.expires = jiffies; 450 } 451 452 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 453 { 454 struct tpacket_kbdq_core *pkc; 455 456 if (tx_ring) 457 BUG(); 458 459 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 460 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 461 } 462 463 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 464 int blk_size_in_bytes) 465 { 466 struct net_device *dev; 467 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 468 struct ethtool_cmd ecmd; 469 int err; 470 u32 speed; 471 472 rtnl_lock(); 473 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 474 if (unlikely(!dev)) { 475 rtnl_unlock(); 476 return DEFAULT_PRB_RETIRE_TOV; 477 } 478 err = __ethtool_get_settings(dev, &ecmd); 479 speed = ethtool_cmd_speed(&ecmd); 480 rtnl_unlock(); 481 if (!err) { 482 /* 483 * If the link speed is so slow you don't really 484 * need to worry about perf anyways 485 */ 486 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 487 return DEFAULT_PRB_RETIRE_TOV; 488 } else { 489 msec = 1; 490 div = speed / 1000; 491 } 492 } 493 494 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 495 496 if (div) 497 mbits /= div; 498 499 tmo = mbits * msec; 500 501 if (div) 502 return tmo+1; 503 return tmo; 504 } 505 506 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 507 union tpacket_req_u *req_u) 508 { 509 p1->feature_req_word = req_u->req3.tp_feature_req_word; 510 } 511 512 static void init_prb_bdqc(struct packet_sock *po, 513 struct packet_ring_buffer *rb, 514 struct pgv *pg_vec, 515 union tpacket_req_u *req_u, int tx_ring) 516 { 517 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 518 struct tpacket_block_desc *pbd; 519 520 memset(p1, 0x0, sizeof(*p1)); 521 522 p1->knxt_seq_num = 1; 523 p1->pkbdq = pg_vec; 524 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 525 p1->pkblk_start = pg_vec[0].buffer; 526 p1->kblk_size = req_u->req3.tp_block_size; 527 p1->knum_blocks = req_u->req3.tp_block_nr; 528 p1->hdrlen = po->tp_hdrlen; 529 p1->version = po->tp_version; 530 p1->last_kactive_blk_num = 0; 531 po->stats.stats3.tp_freeze_q_cnt = 0; 532 if (req_u->req3.tp_retire_blk_tov) 533 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 534 else 535 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 536 req_u->req3.tp_block_size); 537 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 538 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 539 540 prb_init_ft_ops(p1, req_u); 541 prb_setup_retire_blk_timer(po, tx_ring); 542 prb_open_block(p1, pbd); 543 } 544 545 /* Do NOT update the last_blk_num first. 546 * Assumes sk_buff_head lock is held. 547 */ 548 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 549 { 550 mod_timer(&pkc->retire_blk_timer, 551 jiffies + pkc->tov_in_jiffies); 552 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 553 } 554 555 /* 556 * Timer logic: 557 * 1) We refresh the timer only when we open a block. 558 * By doing this we don't waste cycles refreshing the timer 559 * on packet-by-packet basis. 560 * 561 * With a 1MB block-size, on a 1Gbps line, it will take 562 * i) ~8 ms to fill a block + ii) memcpy etc. 563 * In this cut we are not accounting for the memcpy time. 564 * 565 * So, if the user sets the 'tmo' to 10ms then the timer 566 * will never fire while the block is still getting filled 567 * (which is what we want). However, the user could choose 568 * to close a block early and that's fine. 569 * 570 * But when the timer does fire, we check whether or not to refresh it. 571 * Since the tmo granularity is in msecs, it is not too expensive 572 * to refresh the timer, lets say every '8' msecs. 573 * Either the user can set the 'tmo' or we can derive it based on 574 * a) line-speed and b) block-size. 575 * prb_calc_retire_blk_tmo() calculates the tmo. 576 * 577 */ 578 static void prb_retire_rx_blk_timer_expired(unsigned long data) 579 { 580 struct packet_sock *po = (struct packet_sock *)data; 581 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 582 unsigned int frozen; 583 struct tpacket_block_desc *pbd; 584 585 spin_lock(&po->sk.sk_receive_queue.lock); 586 587 frozen = prb_queue_frozen(pkc); 588 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 589 590 if (unlikely(pkc->delete_blk_timer)) 591 goto out; 592 593 /* We only need to plug the race when the block is partially filled. 594 * tpacket_rcv: 595 * lock(); increment BLOCK_NUM_PKTS; unlock() 596 * copy_bits() is in progress ... 597 * timer fires on other cpu: 598 * we can't retire the current block because copy_bits 599 * is in progress. 600 * 601 */ 602 if (BLOCK_NUM_PKTS(pbd)) { 603 while (atomic_read(&pkc->blk_fill_in_prog)) { 604 /* Waiting for skb_copy_bits to finish... */ 605 cpu_relax(); 606 } 607 } 608 609 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 610 if (!frozen) { 611 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 612 if (!prb_dispatch_next_block(pkc, po)) 613 goto refresh_timer; 614 else 615 goto out; 616 } else { 617 /* Case 1. Queue was frozen because user-space was 618 * lagging behind. 619 */ 620 if (prb_curr_blk_in_use(pkc, pbd)) { 621 /* 622 * Ok, user-space is still behind. 623 * So just refresh the timer. 624 */ 625 goto refresh_timer; 626 } else { 627 /* Case 2. queue was frozen,user-space caught up, 628 * now the link went idle && the timer fired. 629 * We don't have a block to close.So we open this 630 * block and restart the timer. 631 * opening a block thaws the queue,restarts timer 632 * Thawing/timer-refresh is a side effect. 633 */ 634 prb_open_block(pkc, pbd); 635 goto out; 636 } 637 } 638 } 639 640 refresh_timer: 641 _prb_refresh_rx_retire_blk_timer(pkc); 642 643 out: 644 spin_unlock(&po->sk.sk_receive_queue.lock); 645 } 646 647 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 648 struct tpacket_block_desc *pbd1, __u32 status) 649 { 650 /* Flush everything minus the block header */ 651 652 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 653 u8 *start, *end; 654 655 start = (u8 *)pbd1; 656 657 /* Skip the block header(we know header WILL fit in 4K) */ 658 start += PAGE_SIZE; 659 660 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 661 for (; start < end; start += PAGE_SIZE) 662 flush_dcache_page(pgv_to_page(start)); 663 664 smp_wmb(); 665 #endif 666 667 /* Now update the block status. */ 668 669 BLOCK_STATUS(pbd1) = status; 670 671 /* Flush the block header */ 672 673 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 674 start = (u8 *)pbd1; 675 flush_dcache_page(pgv_to_page(start)); 676 677 smp_wmb(); 678 #endif 679 } 680 681 /* 682 * Side effect: 683 * 684 * 1) flush the block 685 * 2) Increment active_blk_num 686 * 687 * Note:We DONT refresh the timer on purpose. 688 * Because almost always the next block will be opened. 689 */ 690 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 691 struct tpacket_block_desc *pbd1, 692 struct packet_sock *po, unsigned int stat) 693 { 694 __u32 status = TP_STATUS_USER | stat; 695 696 struct tpacket3_hdr *last_pkt; 697 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 698 699 if (po->stats.stats3.tp_drops) 700 status |= TP_STATUS_LOSING; 701 702 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 703 last_pkt->tp_next_offset = 0; 704 705 /* Get the ts of the last pkt */ 706 if (BLOCK_NUM_PKTS(pbd1)) { 707 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 708 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 709 } else { 710 /* Ok, we tmo'd - so get the current time */ 711 struct timespec ts; 712 getnstimeofday(&ts); 713 h1->ts_last_pkt.ts_sec = ts.tv_sec; 714 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 715 } 716 717 smp_wmb(); 718 719 /* Flush the block */ 720 prb_flush_block(pkc1, pbd1, status); 721 722 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 723 } 724 725 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 726 { 727 pkc->reset_pending_on_curr_blk = 0; 728 } 729 730 /* 731 * Side effect of opening a block: 732 * 733 * 1) prb_queue is thawed. 734 * 2) retire_blk_timer is refreshed. 735 * 736 */ 737 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 738 struct tpacket_block_desc *pbd1) 739 { 740 struct timespec ts; 741 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 742 743 smp_rmb(); 744 745 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { 746 747 /* We could have just memset this but we will lose the 748 * flexibility of making the priv area sticky 749 */ 750 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 751 BLOCK_NUM_PKTS(pbd1) = 0; 752 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 753 getnstimeofday(&ts); 754 h1->ts_first_pkt.ts_sec = ts.tv_sec; 755 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 756 pkc1->pkblk_start = (char *)pbd1; 757 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 758 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 759 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 760 pbd1->version = pkc1->version; 761 pkc1->prev = pkc1->nxt_offset; 762 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 763 prb_thaw_queue(pkc1); 764 _prb_refresh_rx_retire_blk_timer(pkc1); 765 766 smp_wmb(); 767 768 return; 769 } 770 771 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", 772 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); 773 dump_stack(); 774 BUG(); 775 } 776 777 /* 778 * Queue freeze logic: 779 * 1) Assume tp_block_nr = 8 blocks. 780 * 2) At time 't0', user opens Rx ring. 781 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 782 * 4) user-space is either sleeping or processing block '0'. 783 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 784 * it will close block-7,loop around and try to fill block '0'. 785 * call-flow: 786 * __packet_lookup_frame_in_block 787 * prb_retire_current_block() 788 * prb_dispatch_next_block() 789 * |->(BLOCK_STATUS == USER) evaluates to true 790 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 791 * 6) Now there are two cases: 792 * 6.1) Link goes idle right after the queue is frozen. 793 * But remember, the last open_block() refreshed the timer. 794 * When this timer expires,it will refresh itself so that we can 795 * re-open block-0 in near future. 796 * 6.2) Link is busy and keeps on receiving packets. This is a simple 797 * case and __packet_lookup_frame_in_block will check if block-0 798 * is free and can now be re-used. 799 */ 800 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 801 struct packet_sock *po) 802 { 803 pkc->reset_pending_on_curr_blk = 1; 804 po->stats.stats3.tp_freeze_q_cnt++; 805 } 806 807 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 808 809 /* 810 * If the next block is free then we will dispatch it 811 * and return a good offset. 812 * Else, we will freeze the queue. 813 * So, caller must check the return value. 814 */ 815 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 816 struct packet_sock *po) 817 { 818 struct tpacket_block_desc *pbd; 819 820 smp_rmb(); 821 822 /* 1. Get current block num */ 823 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 824 825 /* 2. If this block is currently in_use then freeze the queue */ 826 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 827 prb_freeze_queue(pkc, po); 828 return NULL; 829 } 830 831 /* 832 * 3. 833 * open this block and return the offset where the first packet 834 * needs to get stored. 835 */ 836 prb_open_block(pkc, pbd); 837 return (void *)pkc->nxt_offset; 838 } 839 840 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 841 struct packet_sock *po, unsigned int status) 842 { 843 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 844 845 /* retire/close the current block */ 846 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 847 /* 848 * Plug the case where copy_bits() is in progress on 849 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 850 * have space to copy the pkt in the current block and 851 * called prb_retire_current_block() 852 * 853 * We don't need to worry about the TMO case because 854 * the timer-handler already handled this case. 855 */ 856 if (!(status & TP_STATUS_BLK_TMO)) { 857 while (atomic_read(&pkc->blk_fill_in_prog)) { 858 /* Waiting for skb_copy_bits to finish... */ 859 cpu_relax(); 860 } 861 } 862 prb_close_block(pkc, pbd, po, status); 863 return; 864 } 865 866 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); 867 dump_stack(); 868 BUG(); 869 } 870 871 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 872 struct tpacket_block_desc *pbd) 873 { 874 return TP_STATUS_USER & BLOCK_STATUS(pbd); 875 } 876 877 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 878 { 879 return pkc->reset_pending_on_curr_blk; 880 } 881 882 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 883 { 884 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 885 atomic_dec(&pkc->blk_fill_in_prog); 886 } 887 888 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 889 struct tpacket3_hdr *ppd) 890 { 891 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 892 } 893 894 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 895 struct tpacket3_hdr *ppd) 896 { 897 ppd->hv1.tp_rxhash = 0; 898 } 899 900 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 901 struct tpacket3_hdr *ppd) 902 { 903 if (vlan_tx_tag_present(pkc->skb)) { 904 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 905 ppd->tp_status = TP_STATUS_VLAN_VALID; 906 } else { 907 ppd->hv1.tp_vlan_tci = 0; 908 ppd->tp_status = TP_STATUS_AVAILABLE; 909 } 910 } 911 912 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 913 struct tpacket3_hdr *ppd) 914 { 915 prb_fill_vlan_info(pkc, ppd); 916 917 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 918 prb_fill_rxhash(pkc, ppd); 919 else 920 prb_clear_rxhash(pkc, ppd); 921 } 922 923 static void prb_fill_curr_block(char *curr, 924 struct tpacket_kbdq_core *pkc, 925 struct tpacket_block_desc *pbd, 926 unsigned int len) 927 { 928 struct tpacket3_hdr *ppd; 929 930 ppd = (struct tpacket3_hdr *)curr; 931 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 932 pkc->prev = curr; 933 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 934 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 935 BLOCK_NUM_PKTS(pbd) += 1; 936 atomic_inc(&pkc->blk_fill_in_prog); 937 prb_run_all_ft_ops(pkc, ppd); 938 } 939 940 /* Assumes caller has the sk->rx_queue.lock */ 941 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 942 struct sk_buff *skb, 943 int status, 944 unsigned int len 945 ) 946 { 947 struct tpacket_kbdq_core *pkc; 948 struct tpacket_block_desc *pbd; 949 char *curr, *end; 950 951 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 952 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 953 954 /* Queue is frozen when user space is lagging behind */ 955 if (prb_queue_frozen(pkc)) { 956 /* 957 * Check if that last block which caused the queue to freeze, 958 * is still in_use by user-space. 959 */ 960 if (prb_curr_blk_in_use(pkc, pbd)) { 961 /* Can't record this packet */ 962 return NULL; 963 } else { 964 /* 965 * Ok, the block was released by user-space. 966 * Now let's open that block. 967 * opening a block also thaws the queue. 968 * Thawing is a side effect. 969 */ 970 prb_open_block(pkc, pbd); 971 } 972 } 973 974 smp_mb(); 975 curr = pkc->nxt_offset; 976 pkc->skb = skb; 977 end = (char *)pbd + pkc->kblk_size; 978 979 /* first try the current block */ 980 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 981 prb_fill_curr_block(curr, pkc, pbd, len); 982 return (void *)curr; 983 } 984 985 /* Ok, close the current block */ 986 prb_retire_current_block(pkc, po, 0); 987 988 /* Now, try to dispatch the next block */ 989 curr = (char *)prb_dispatch_next_block(pkc, po); 990 if (curr) { 991 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 992 prb_fill_curr_block(curr, pkc, pbd, len); 993 return (void *)curr; 994 } 995 996 /* 997 * No free blocks are available.user_space hasn't caught up yet. 998 * Queue was just frozen and now this packet will get dropped. 999 */ 1000 return NULL; 1001 } 1002 1003 static void *packet_current_rx_frame(struct packet_sock *po, 1004 struct sk_buff *skb, 1005 int status, unsigned int len) 1006 { 1007 char *curr = NULL; 1008 switch (po->tp_version) { 1009 case TPACKET_V1: 1010 case TPACKET_V2: 1011 curr = packet_lookup_frame(po, &po->rx_ring, 1012 po->rx_ring.head, status); 1013 return curr; 1014 case TPACKET_V3: 1015 return __packet_lookup_frame_in_block(po, skb, status, len); 1016 default: 1017 WARN(1, "TPACKET version not supported\n"); 1018 BUG(); 1019 return NULL; 1020 } 1021 } 1022 1023 static void *prb_lookup_block(struct packet_sock *po, 1024 struct packet_ring_buffer *rb, 1025 unsigned int idx, 1026 int status) 1027 { 1028 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1029 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1030 1031 if (status != BLOCK_STATUS(pbd)) 1032 return NULL; 1033 return pbd; 1034 } 1035 1036 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1037 { 1038 unsigned int prev; 1039 if (rb->prb_bdqc.kactive_blk_num) 1040 prev = rb->prb_bdqc.kactive_blk_num-1; 1041 else 1042 prev = rb->prb_bdqc.knum_blocks-1; 1043 return prev; 1044 } 1045 1046 /* Assumes caller has held the rx_queue.lock */ 1047 static void *__prb_previous_block(struct packet_sock *po, 1048 struct packet_ring_buffer *rb, 1049 int status) 1050 { 1051 unsigned int previous = prb_previous_blk_num(rb); 1052 return prb_lookup_block(po, rb, previous, status); 1053 } 1054 1055 static void *packet_previous_rx_frame(struct packet_sock *po, 1056 struct packet_ring_buffer *rb, 1057 int status) 1058 { 1059 if (po->tp_version <= TPACKET_V2) 1060 return packet_previous_frame(po, rb, status); 1061 1062 return __prb_previous_block(po, rb, status); 1063 } 1064 1065 static void packet_increment_rx_head(struct packet_sock *po, 1066 struct packet_ring_buffer *rb) 1067 { 1068 switch (po->tp_version) { 1069 case TPACKET_V1: 1070 case TPACKET_V2: 1071 return packet_increment_head(rb); 1072 case TPACKET_V3: 1073 default: 1074 WARN(1, "TPACKET version not supported.\n"); 1075 BUG(); 1076 return; 1077 } 1078 } 1079 1080 static void *packet_previous_frame(struct packet_sock *po, 1081 struct packet_ring_buffer *rb, 1082 int status) 1083 { 1084 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1085 return packet_lookup_frame(po, rb, previous, status); 1086 } 1087 1088 static void packet_increment_head(struct packet_ring_buffer *buff) 1089 { 1090 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1091 } 1092 1093 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1094 { 1095 struct sock *sk = &po->sk; 1096 bool has_room; 1097 1098 if (po->prot_hook.func != tpacket_rcv) 1099 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize) 1100 <= sk->sk_rcvbuf; 1101 1102 spin_lock(&sk->sk_receive_queue.lock); 1103 if (po->tp_version == TPACKET_V3) 1104 has_room = prb_lookup_block(po, &po->rx_ring, 1105 po->rx_ring.prb_bdqc.kactive_blk_num, 1106 TP_STATUS_KERNEL); 1107 else 1108 has_room = packet_lookup_frame(po, &po->rx_ring, 1109 po->rx_ring.head, 1110 TP_STATUS_KERNEL); 1111 spin_unlock(&sk->sk_receive_queue.lock); 1112 1113 return has_room; 1114 } 1115 1116 static void packet_sock_destruct(struct sock *sk) 1117 { 1118 skb_queue_purge(&sk->sk_error_queue); 1119 1120 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1121 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1122 1123 if (!sock_flag(sk, SOCK_DEAD)) { 1124 pr_err("Attempt to release alive packet socket: %p\n", sk); 1125 return; 1126 } 1127 1128 sk_refcnt_debug_dec(sk); 1129 } 1130 1131 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1132 { 1133 int x = atomic_read(&f->rr_cur) + 1; 1134 1135 if (x >= num) 1136 x = 0; 1137 1138 return x; 1139 } 1140 1141 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1142 struct sk_buff *skb, 1143 unsigned int num) 1144 { 1145 return (((u64)skb->rxhash) * num) >> 32; 1146 } 1147 1148 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1149 struct sk_buff *skb, 1150 unsigned int num) 1151 { 1152 int cur, old; 1153 1154 cur = atomic_read(&f->rr_cur); 1155 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1156 fanout_rr_next(f, num))) != cur) 1157 cur = old; 1158 return cur; 1159 } 1160 1161 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1162 struct sk_buff *skb, 1163 unsigned int num) 1164 { 1165 return smp_processor_id() % num; 1166 } 1167 1168 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1169 struct sk_buff *skb, 1170 unsigned int idx, unsigned int skip, 1171 unsigned int num) 1172 { 1173 unsigned int i, j; 1174 1175 i = j = min_t(int, f->next[idx], num - 1); 1176 do { 1177 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) { 1178 if (i != j) 1179 f->next[idx] = i; 1180 return i; 1181 } 1182 if (++i == num) 1183 i = 0; 1184 } while (i != j); 1185 1186 return idx; 1187 } 1188 1189 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1190 { 1191 return f->flags & (flag >> 8); 1192 } 1193 1194 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1195 struct packet_type *pt, struct net_device *orig_dev) 1196 { 1197 struct packet_fanout *f = pt->af_packet_priv; 1198 unsigned int num = f->num_members; 1199 struct packet_sock *po; 1200 unsigned int idx; 1201 1202 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1203 !num) { 1204 kfree_skb(skb); 1205 return 0; 1206 } 1207 1208 switch (f->type) { 1209 case PACKET_FANOUT_HASH: 1210 default: 1211 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1212 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1213 if (!skb) 1214 return 0; 1215 } 1216 skb_get_rxhash(skb); 1217 idx = fanout_demux_hash(f, skb, num); 1218 break; 1219 case PACKET_FANOUT_LB: 1220 idx = fanout_demux_lb(f, skb, num); 1221 break; 1222 case PACKET_FANOUT_CPU: 1223 idx = fanout_demux_cpu(f, skb, num); 1224 break; 1225 case PACKET_FANOUT_ROLLOVER: 1226 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num); 1227 break; 1228 } 1229 1230 po = pkt_sk(f->arr[idx]); 1231 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) && 1232 unlikely(!packet_rcv_has_room(po, skb))) { 1233 idx = fanout_demux_rollover(f, skb, idx, idx, num); 1234 po = pkt_sk(f->arr[idx]); 1235 } 1236 1237 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1238 } 1239 1240 DEFINE_MUTEX(fanout_mutex); 1241 EXPORT_SYMBOL_GPL(fanout_mutex); 1242 static LIST_HEAD(fanout_list); 1243 1244 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1245 { 1246 struct packet_fanout *f = po->fanout; 1247 1248 spin_lock(&f->lock); 1249 f->arr[f->num_members] = sk; 1250 smp_wmb(); 1251 f->num_members++; 1252 spin_unlock(&f->lock); 1253 } 1254 1255 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1256 { 1257 struct packet_fanout *f = po->fanout; 1258 int i; 1259 1260 spin_lock(&f->lock); 1261 for (i = 0; i < f->num_members; i++) { 1262 if (f->arr[i] == sk) 1263 break; 1264 } 1265 BUG_ON(i >= f->num_members); 1266 f->arr[i] = f->arr[f->num_members - 1]; 1267 f->num_members--; 1268 spin_unlock(&f->lock); 1269 } 1270 1271 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk) 1272 { 1273 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) 1274 return true; 1275 1276 return false; 1277 } 1278 1279 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1280 { 1281 struct packet_sock *po = pkt_sk(sk); 1282 struct packet_fanout *f, *match; 1283 u8 type = type_flags & 0xff; 1284 u8 flags = type_flags >> 8; 1285 int err; 1286 1287 switch (type) { 1288 case PACKET_FANOUT_ROLLOVER: 1289 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1290 return -EINVAL; 1291 case PACKET_FANOUT_HASH: 1292 case PACKET_FANOUT_LB: 1293 case PACKET_FANOUT_CPU: 1294 break; 1295 default: 1296 return -EINVAL; 1297 } 1298 1299 if (!po->running) 1300 return -EINVAL; 1301 1302 if (po->fanout) 1303 return -EALREADY; 1304 1305 mutex_lock(&fanout_mutex); 1306 match = NULL; 1307 list_for_each_entry(f, &fanout_list, list) { 1308 if (f->id == id && 1309 read_pnet(&f->net) == sock_net(sk)) { 1310 match = f; 1311 break; 1312 } 1313 } 1314 err = -EINVAL; 1315 if (match && match->flags != flags) 1316 goto out; 1317 if (!match) { 1318 err = -ENOMEM; 1319 match = kzalloc(sizeof(*match), GFP_KERNEL); 1320 if (!match) 1321 goto out; 1322 write_pnet(&match->net, sock_net(sk)); 1323 match->id = id; 1324 match->type = type; 1325 match->flags = flags; 1326 atomic_set(&match->rr_cur, 0); 1327 INIT_LIST_HEAD(&match->list); 1328 spin_lock_init(&match->lock); 1329 atomic_set(&match->sk_ref, 0); 1330 match->prot_hook.type = po->prot_hook.type; 1331 match->prot_hook.dev = po->prot_hook.dev; 1332 match->prot_hook.func = packet_rcv_fanout; 1333 match->prot_hook.af_packet_priv = match; 1334 match->prot_hook.id_match = match_fanout_group; 1335 dev_add_pack(&match->prot_hook); 1336 list_add(&match->list, &fanout_list); 1337 } 1338 err = -EINVAL; 1339 if (match->type == type && 1340 match->prot_hook.type == po->prot_hook.type && 1341 match->prot_hook.dev == po->prot_hook.dev) { 1342 err = -ENOSPC; 1343 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1344 __dev_remove_pack(&po->prot_hook); 1345 po->fanout = match; 1346 atomic_inc(&match->sk_ref); 1347 __fanout_link(sk, po); 1348 err = 0; 1349 } 1350 } 1351 out: 1352 mutex_unlock(&fanout_mutex); 1353 return err; 1354 } 1355 1356 static void fanout_release(struct sock *sk) 1357 { 1358 struct packet_sock *po = pkt_sk(sk); 1359 struct packet_fanout *f; 1360 1361 f = po->fanout; 1362 if (!f) 1363 return; 1364 1365 mutex_lock(&fanout_mutex); 1366 po->fanout = NULL; 1367 1368 if (atomic_dec_and_test(&f->sk_ref)) { 1369 list_del(&f->list); 1370 dev_remove_pack(&f->prot_hook); 1371 kfree(f); 1372 } 1373 mutex_unlock(&fanout_mutex); 1374 } 1375 1376 static const struct proto_ops packet_ops; 1377 1378 static const struct proto_ops packet_ops_spkt; 1379 1380 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1381 struct packet_type *pt, struct net_device *orig_dev) 1382 { 1383 struct sock *sk; 1384 struct sockaddr_pkt *spkt; 1385 1386 /* 1387 * When we registered the protocol we saved the socket in the data 1388 * field for just this event. 1389 */ 1390 1391 sk = pt->af_packet_priv; 1392 1393 /* 1394 * Yank back the headers [hope the device set this 1395 * right or kerboom...] 1396 * 1397 * Incoming packets have ll header pulled, 1398 * push it back. 1399 * 1400 * For outgoing ones skb->data == skb_mac_header(skb) 1401 * so that this procedure is noop. 1402 */ 1403 1404 if (skb->pkt_type == PACKET_LOOPBACK) 1405 goto out; 1406 1407 if (!net_eq(dev_net(dev), sock_net(sk))) 1408 goto out; 1409 1410 skb = skb_share_check(skb, GFP_ATOMIC); 1411 if (skb == NULL) 1412 goto oom; 1413 1414 /* drop any routing info */ 1415 skb_dst_drop(skb); 1416 1417 /* drop conntrack reference */ 1418 nf_reset(skb); 1419 1420 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1421 1422 skb_push(skb, skb->data - skb_mac_header(skb)); 1423 1424 /* 1425 * The SOCK_PACKET socket receives _all_ frames. 1426 */ 1427 1428 spkt->spkt_family = dev->type; 1429 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1430 spkt->spkt_protocol = skb->protocol; 1431 1432 /* 1433 * Charge the memory to the socket. This is done specifically 1434 * to prevent sockets using all the memory up. 1435 */ 1436 1437 if (sock_queue_rcv_skb(sk, skb) == 0) 1438 return 0; 1439 1440 out: 1441 kfree_skb(skb); 1442 oom: 1443 return 0; 1444 } 1445 1446 1447 /* 1448 * Output a raw packet to a device layer. This bypasses all the other 1449 * protocol layers and you must therefore supply it with a complete frame 1450 */ 1451 1452 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1453 struct msghdr *msg, size_t len) 1454 { 1455 struct sock *sk = sock->sk; 1456 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1457 struct sk_buff *skb = NULL; 1458 struct net_device *dev; 1459 __be16 proto = 0; 1460 int err; 1461 int extra_len = 0; 1462 1463 /* 1464 * Get and verify the address. 1465 */ 1466 1467 if (saddr) { 1468 if (msg->msg_namelen < sizeof(struct sockaddr)) 1469 return -EINVAL; 1470 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1471 proto = saddr->spkt_protocol; 1472 } else 1473 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1474 1475 /* 1476 * Find the device first to size check it 1477 */ 1478 1479 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1480 retry: 1481 rcu_read_lock(); 1482 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1483 err = -ENODEV; 1484 if (dev == NULL) 1485 goto out_unlock; 1486 1487 err = -ENETDOWN; 1488 if (!(dev->flags & IFF_UP)) 1489 goto out_unlock; 1490 1491 /* 1492 * You may not queue a frame bigger than the mtu. This is the lowest level 1493 * raw protocol and you must do your own fragmentation at this level. 1494 */ 1495 1496 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1497 if (!netif_supports_nofcs(dev)) { 1498 err = -EPROTONOSUPPORT; 1499 goto out_unlock; 1500 } 1501 extra_len = 4; /* We're doing our own CRC */ 1502 } 1503 1504 err = -EMSGSIZE; 1505 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1506 goto out_unlock; 1507 1508 if (!skb) { 1509 size_t reserved = LL_RESERVED_SPACE(dev); 1510 int tlen = dev->needed_tailroom; 1511 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1512 1513 rcu_read_unlock(); 1514 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1515 if (skb == NULL) 1516 return -ENOBUFS; 1517 /* FIXME: Save some space for broken drivers that write a hard 1518 * header at transmission time by themselves. PPP is the notable 1519 * one here. This should really be fixed at the driver level. 1520 */ 1521 skb_reserve(skb, reserved); 1522 skb_reset_network_header(skb); 1523 1524 /* Try to align data part correctly */ 1525 if (hhlen) { 1526 skb->data -= hhlen; 1527 skb->tail -= hhlen; 1528 if (len < hhlen) 1529 skb_reset_network_header(skb); 1530 } 1531 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1532 if (err) 1533 goto out_free; 1534 goto retry; 1535 } 1536 1537 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1538 /* Earlier code assumed this would be a VLAN pkt, 1539 * double-check this now that we have the actual 1540 * packet in hand. 1541 */ 1542 struct ethhdr *ehdr; 1543 skb_reset_mac_header(skb); 1544 ehdr = eth_hdr(skb); 1545 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1546 err = -EMSGSIZE; 1547 goto out_unlock; 1548 } 1549 } 1550 1551 skb->protocol = proto; 1552 skb->dev = dev; 1553 skb->priority = sk->sk_priority; 1554 skb->mark = sk->sk_mark; 1555 1556 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1557 1558 if (unlikely(extra_len == 4)) 1559 skb->no_fcs = 1; 1560 1561 skb_probe_transport_header(skb, 0); 1562 1563 dev_queue_xmit(skb); 1564 rcu_read_unlock(); 1565 return len; 1566 1567 out_unlock: 1568 rcu_read_unlock(); 1569 out_free: 1570 kfree_skb(skb); 1571 return err; 1572 } 1573 1574 static unsigned int run_filter(const struct sk_buff *skb, 1575 const struct sock *sk, 1576 unsigned int res) 1577 { 1578 struct sk_filter *filter; 1579 1580 rcu_read_lock(); 1581 filter = rcu_dereference(sk->sk_filter); 1582 if (filter != NULL) 1583 res = SK_RUN_FILTER(filter, skb); 1584 rcu_read_unlock(); 1585 1586 return res; 1587 } 1588 1589 /* 1590 * This function makes lazy skb cloning in hope that most of packets 1591 * are discarded by BPF. 1592 * 1593 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1594 * and skb->cb are mangled. It works because (and until) packets 1595 * falling here are owned by current CPU. Output packets are cloned 1596 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1597 * sequencially, so that if we return skb to original state on exit, 1598 * we will not harm anyone. 1599 */ 1600 1601 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1602 struct packet_type *pt, struct net_device *orig_dev) 1603 { 1604 struct sock *sk; 1605 struct sockaddr_ll *sll; 1606 struct packet_sock *po; 1607 u8 *skb_head = skb->data; 1608 int skb_len = skb->len; 1609 unsigned int snaplen, res; 1610 1611 if (skb->pkt_type == PACKET_LOOPBACK) 1612 goto drop; 1613 1614 sk = pt->af_packet_priv; 1615 po = pkt_sk(sk); 1616 1617 if (!net_eq(dev_net(dev), sock_net(sk))) 1618 goto drop; 1619 1620 skb->dev = dev; 1621 1622 if (dev->header_ops) { 1623 /* The device has an explicit notion of ll header, 1624 * exported to higher levels. 1625 * 1626 * Otherwise, the device hides details of its frame 1627 * structure, so that corresponding packet head is 1628 * never delivered to user. 1629 */ 1630 if (sk->sk_type != SOCK_DGRAM) 1631 skb_push(skb, skb->data - skb_mac_header(skb)); 1632 else if (skb->pkt_type == PACKET_OUTGOING) { 1633 /* Special case: outgoing packets have ll header at head */ 1634 skb_pull(skb, skb_network_offset(skb)); 1635 } 1636 } 1637 1638 snaplen = skb->len; 1639 1640 res = run_filter(skb, sk, snaplen); 1641 if (!res) 1642 goto drop_n_restore; 1643 if (snaplen > res) 1644 snaplen = res; 1645 1646 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1647 goto drop_n_acct; 1648 1649 if (skb_shared(skb)) { 1650 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1651 if (nskb == NULL) 1652 goto drop_n_acct; 1653 1654 if (skb_head != skb->data) { 1655 skb->data = skb_head; 1656 skb->len = skb_len; 1657 } 1658 consume_skb(skb); 1659 skb = nskb; 1660 } 1661 1662 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1663 sizeof(skb->cb)); 1664 1665 sll = &PACKET_SKB_CB(skb)->sa.ll; 1666 sll->sll_family = AF_PACKET; 1667 sll->sll_hatype = dev->type; 1668 sll->sll_protocol = skb->protocol; 1669 sll->sll_pkttype = skb->pkt_type; 1670 if (unlikely(po->origdev)) 1671 sll->sll_ifindex = orig_dev->ifindex; 1672 else 1673 sll->sll_ifindex = dev->ifindex; 1674 1675 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1676 1677 PACKET_SKB_CB(skb)->origlen = skb->len; 1678 1679 if (pskb_trim(skb, snaplen)) 1680 goto drop_n_acct; 1681 1682 skb_set_owner_r(skb, sk); 1683 skb->dev = NULL; 1684 skb_dst_drop(skb); 1685 1686 /* drop conntrack reference */ 1687 nf_reset(skb); 1688 1689 spin_lock(&sk->sk_receive_queue.lock); 1690 po->stats.stats1.tp_packets++; 1691 skb->dropcount = atomic_read(&sk->sk_drops); 1692 __skb_queue_tail(&sk->sk_receive_queue, skb); 1693 spin_unlock(&sk->sk_receive_queue.lock); 1694 sk->sk_data_ready(sk, skb->len); 1695 return 0; 1696 1697 drop_n_acct: 1698 spin_lock(&sk->sk_receive_queue.lock); 1699 po->stats.stats1.tp_drops++; 1700 atomic_inc(&sk->sk_drops); 1701 spin_unlock(&sk->sk_receive_queue.lock); 1702 1703 drop_n_restore: 1704 if (skb_head != skb->data && skb_shared(skb)) { 1705 skb->data = skb_head; 1706 skb->len = skb_len; 1707 } 1708 drop: 1709 consume_skb(skb); 1710 return 0; 1711 } 1712 1713 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1714 struct packet_type *pt, struct net_device *orig_dev) 1715 { 1716 struct sock *sk; 1717 struct packet_sock *po; 1718 struct sockaddr_ll *sll; 1719 union tpacket_uhdr h; 1720 u8 *skb_head = skb->data; 1721 int skb_len = skb->len; 1722 unsigned int snaplen, res; 1723 unsigned long status = TP_STATUS_USER; 1724 unsigned short macoff, netoff, hdrlen; 1725 struct sk_buff *copy_skb = NULL; 1726 struct timespec ts; 1727 __u32 ts_status; 1728 1729 if (skb->pkt_type == PACKET_LOOPBACK) 1730 goto drop; 1731 1732 sk = pt->af_packet_priv; 1733 po = pkt_sk(sk); 1734 1735 if (!net_eq(dev_net(dev), sock_net(sk))) 1736 goto drop; 1737 1738 if (dev->header_ops) { 1739 if (sk->sk_type != SOCK_DGRAM) 1740 skb_push(skb, skb->data - skb_mac_header(skb)); 1741 else if (skb->pkt_type == PACKET_OUTGOING) { 1742 /* Special case: outgoing packets have ll header at head */ 1743 skb_pull(skb, skb_network_offset(skb)); 1744 } 1745 } 1746 1747 if (skb->ip_summed == CHECKSUM_PARTIAL) 1748 status |= TP_STATUS_CSUMNOTREADY; 1749 1750 snaplen = skb->len; 1751 1752 res = run_filter(skb, sk, snaplen); 1753 if (!res) 1754 goto drop_n_restore; 1755 if (snaplen > res) 1756 snaplen = res; 1757 1758 if (sk->sk_type == SOCK_DGRAM) { 1759 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1760 po->tp_reserve; 1761 } else { 1762 unsigned int maclen = skb_network_offset(skb); 1763 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1764 (maclen < 16 ? 16 : maclen)) + 1765 po->tp_reserve; 1766 macoff = netoff - maclen; 1767 } 1768 if (po->tp_version <= TPACKET_V2) { 1769 if (macoff + snaplen > po->rx_ring.frame_size) { 1770 if (po->copy_thresh && 1771 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1772 if (skb_shared(skb)) { 1773 copy_skb = skb_clone(skb, GFP_ATOMIC); 1774 } else { 1775 copy_skb = skb_get(skb); 1776 skb_head = skb->data; 1777 } 1778 if (copy_skb) 1779 skb_set_owner_r(copy_skb, sk); 1780 } 1781 snaplen = po->rx_ring.frame_size - macoff; 1782 if ((int)snaplen < 0) 1783 snaplen = 0; 1784 } 1785 } 1786 spin_lock(&sk->sk_receive_queue.lock); 1787 h.raw = packet_current_rx_frame(po, skb, 1788 TP_STATUS_KERNEL, (macoff+snaplen)); 1789 if (!h.raw) 1790 goto ring_is_full; 1791 if (po->tp_version <= TPACKET_V2) { 1792 packet_increment_rx_head(po, &po->rx_ring); 1793 /* 1794 * LOSING will be reported till you read the stats, 1795 * because it's COR - Clear On Read. 1796 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1797 * at packet level. 1798 */ 1799 if (po->stats.stats1.tp_drops) 1800 status |= TP_STATUS_LOSING; 1801 } 1802 po->stats.stats1.tp_packets++; 1803 if (copy_skb) { 1804 status |= TP_STATUS_COPY; 1805 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1806 } 1807 spin_unlock(&sk->sk_receive_queue.lock); 1808 1809 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1810 1811 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 1812 getnstimeofday(&ts); 1813 1814 status |= ts_status; 1815 1816 switch (po->tp_version) { 1817 case TPACKET_V1: 1818 h.h1->tp_len = skb->len; 1819 h.h1->tp_snaplen = snaplen; 1820 h.h1->tp_mac = macoff; 1821 h.h1->tp_net = netoff; 1822 h.h1->tp_sec = ts.tv_sec; 1823 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 1824 hdrlen = sizeof(*h.h1); 1825 break; 1826 case TPACKET_V2: 1827 h.h2->tp_len = skb->len; 1828 h.h2->tp_snaplen = snaplen; 1829 h.h2->tp_mac = macoff; 1830 h.h2->tp_net = netoff; 1831 h.h2->tp_sec = ts.tv_sec; 1832 h.h2->tp_nsec = ts.tv_nsec; 1833 if (vlan_tx_tag_present(skb)) { 1834 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1835 status |= TP_STATUS_VLAN_VALID; 1836 } else { 1837 h.h2->tp_vlan_tci = 0; 1838 } 1839 h.h2->tp_padding = 0; 1840 hdrlen = sizeof(*h.h2); 1841 break; 1842 case TPACKET_V3: 1843 /* tp_nxt_offset,vlan are already populated above. 1844 * So DONT clear those fields here 1845 */ 1846 h.h3->tp_status |= status; 1847 h.h3->tp_len = skb->len; 1848 h.h3->tp_snaplen = snaplen; 1849 h.h3->tp_mac = macoff; 1850 h.h3->tp_net = netoff; 1851 h.h3->tp_sec = ts.tv_sec; 1852 h.h3->tp_nsec = ts.tv_nsec; 1853 hdrlen = sizeof(*h.h3); 1854 break; 1855 default: 1856 BUG(); 1857 } 1858 1859 sll = h.raw + TPACKET_ALIGN(hdrlen); 1860 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1861 sll->sll_family = AF_PACKET; 1862 sll->sll_hatype = dev->type; 1863 sll->sll_protocol = skb->protocol; 1864 sll->sll_pkttype = skb->pkt_type; 1865 if (unlikely(po->origdev)) 1866 sll->sll_ifindex = orig_dev->ifindex; 1867 else 1868 sll->sll_ifindex = dev->ifindex; 1869 1870 smp_mb(); 1871 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1872 { 1873 u8 *start, *end; 1874 1875 if (po->tp_version <= TPACKET_V2) { 1876 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1877 + macoff + snaplen); 1878 for (start = h.raw; start < end; start += PAGE_SIZE) 1879 flush_dcache_page(pgv_to_page(start)); 1880 } 1881 smp_wmb(); 1882 } 1883 #endif 1884 if (po->tp_version <= TPACKET_V2) 1885 __packet_set_status(po, h.raw, status); 1886 else 1887 prb_clear_blk_fill_status(&po->rx_ring); 1888 1889 sk->sk_data_ready(sk, 0); 1890 1891 drop_n_restore: 1892 if (skb_head != skb->data && skb_shared(skb)) { 1893 skb->data = skb_head; 1894 skb->len = skb_len; 1895 } 1896 drop: 1897 kfree_skb(skb); 1898 return 0; 1899 1900 ring_is_full: 1901 po->stats.stats1.tp_drops++; 1902 spin_unlock(&sk->sk_receive_queue.lock); 1903 1904 sk->sk_data_ready(sk, 0); 1905 kfree_skb(copy_skb); 1906 goto drop_n_restore; 1907 } 1908 1909 static void tpacket_destruct_skb(struct sk_buff *skb) 1910 { 1911 struct packet_sock *po = pkt_sk(skb->sk); 1912 void *ph; 1913 1914 if (likely(po->tx_ring.pg_vec)) { 1915 __u32 ts; 1916 1917 ph = skb_shinfo(skb)->destructor_arg; 1918 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1919 atomic_dec(&po->tx_ring.pending); 1920 1921 ts = __packet_set_timestamp(po, ph, skb); 1922 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 1923 } 1924 1925 sock_wfree(skb); 1926 } 1927 1928 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1929 void *frame, struct net_device *dev, int size_max, 1930 __be16 proto, unsigned char *addr, int hlen) 1931 { 1932 union tpacket_uhdr ph; 1933 int to_write, offset, len, tp_len, nr_frags, len_max; 1934 struct socket *sock = po->sk.sk_socket; 1935 struct page *page; 1936 void *data; 1937 int err; 1938 1939 ph.raw = frame; 1940 1941 skb->protocol = proto; 1942 skb->dev = dev; 1943 skb->priority = po->sk.sk_priority; 1944 skb->mark = po->sk.sk_mark; 1945 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 1946 skb_shinfo(skb)->destructor_arg = ph.raw; 1947 1948 switch (po->tp_version) { 1949 case TPACKET_V2: 1950 tp_len = ph.h2->tp_len; 1951 break; 1952 default: 1953 tp_len = ph.h1->tp_len; 1954 break; 1955 } 1956 if (unlikely(tp_len > size_max)) { 1957 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1958 return -EMSGSIZE; 1959 } 1960 1961 skb_reserve(skb, hlen); 1962 skb_reset_network_header(skb); 1963 skb_probe_transport_header(skb, 0); 1964 1965 if (po->tp_tx_has_off) { 1966 int off_min, off_max, off; 1967 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 1968 off_max = po->tx_ring.frame_size - tp_len; 1969 if (sock->type == SOCK_DGRAM) { 1970 switch (po->tp_version) { 1971 case TPACKET_V2: 1972 off = ph.h2->tp_net; 1973 break; 1974 default: 1975 off = ph.h1->tp_net; 1976 break; 1977 } 1978 } else { 1979 switch (po->tp_version) { 1980 case TPACKET_V2: 1981 off = ph.h2->tp_mac; 1982 break; 1983 default: 1984 off = ph.h1->tp_mac; 1985 break; 1986 } 1987 } 1988 if (unlikely((off < off_min) || (off_max < off))) 1989 return -EINVAL; 1990 data = ph.raw + off; 1991 } else { 1992 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1993 } 1994 to_write = tp_len; 1995 1996 if (sock->type == SOCK_DGRAM) { 1997 err = dev_hard_header(skb, dev, ntohs(proto), addr, 1998 NULL, tp_len); 1999 if (unlikely(err < 0)) 2000 return -EINVAL; 2001 } else if (dev->hard_header_len) { 2002 /* net device doesn't like empty head */ 2003 if (unlikely(tp_len <= dev->hard_header_len)) { 2004 pr_err("packet size is too short (%d < %d)\n", 2005 tp_len, dev->hard_header_len); 2006 return -EINVAL; 2007 } 2008 2009 skb_push(skb, dev->hard_header_len); 2010 err = skb_store_bits(skb, 0, data, 2011 dev->hard_header_len); 2012 if (unlikely(err)) 2013 return err; 2014 2015 data += dev->hard_header_len; 2016 to_write -= dev->hard_header_len; 2017 } 2018 2019 offset = offset_in_page(data); 2020 len_max = PAGE_SIZE - offset; 2021 len = ((to_write > len_max) ? len_max : to_write); 2022 2023 skb->data_len = to_write; 2024 skb->len += to_write; 2025 skb->truesize += to_write; 2026 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2027 2028 while (likely(to_write)) { 2029 nr_frags = skb_shinfo(skb)->nr_frags; 2030 2031 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2032 pr_err("Packet exceed the number of skb frags(%lu)\n", 2033 MAX_SKB_FRAGS); 2034 return -EFAULT; 2035 } 2036 2037 page = pgv_to_page(data); 2038 data += len; 2039 flush_dcache_page(page); 2040 get_page(page); 2041 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2042 to_write -= len; 2043 offset = 0; 2044 len_max = PAGE_SIZE; 2045 len = ((to_write > len_max) ? len_max : to_write); 2046 } 2047 2048 return tp_len; 2049 } 2050 2051 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2052 { 2053 struct sk_buff *skb; 2054 struct net_device *dev; 2055 __be16 proto; 2056 bool need_rls_dev = false; 2057 int err, reserve = 0; 2058 void *ph; 2059 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2060 int tp_len, size_max; 2061 unsigned char *addr; 2062 int len_sum = 0; 2063 int status = TP_STATUS_AVAILABLE; 2064 int hlen, tlen; 2065 2066 mutex_lock(&po->pg_vec_lock); 2067 2068 if (saddr == NULL) { 2069 dev = po->prot_hook.dev; 2070 proto = po->num; 2071 addr = NULL; 2072 } else { 2073 err = -EINVAL; 2074 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2075 goto out; 2076 if (msg->msg_namelen < (saddr->sll_halen 2077 + offsetof(struct sockaddr_ll, 2078 sll_addr))) 2079 goto out; 2080 proto = saddr->sll_protocol; 2081 addr = saddr->sll_addr; 2082 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2083 need_rls_dev = true; 2084 } 2085 2086 err = -ENXIO; 2087 if (unlikely(dev == NULL)) 2088 goto out; 2089 2090 reserve = dev->hard_header_len; 2091 2092 err = -ENETDOWN; 2093 if (unlikely(!(dev->flags & IFF_UP))) 2094 goto out_put; 2095 2096 size_max = po->tx_ring.frame_size 2097 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2098 2099 if (size_max > dev->mtu + reserve) 2100 size_max = dev->mtu + reserve; 2101 2102 do { 2103 ph = packet_current_frame(po, &po->tx_ring, 2104 TP_STATUS_SEND_REQUEST); 2105 2106 if (unlikely(ph == NULL)) { 2107 schedule(); 2108 continue; 2109 } 2110 2111 status = TP_STATUS_SEND_REQUEST; 2112 hlen = LL_RESERVED_SPACE(dev); 2113 tlen = dev->needed_tailroom; 2114 skb = sock_alloc_send_skb(&po->sk, 2115 hlen + tlen + sizeof(struct sockaddr_ll), 2116 0, &err); 2117 2118 if (unlikely(skb == NULL)) 2119 goto out_status; 2120 2121 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2122 addr, hlen); 2123 2124 if (unlikely(tp_len < 0)) { 2125 if (po->tp_loss) { 2126 __packet_set_status(po, ph, 2127 TP_STATUS_AVAILABLE); 2128 packet_increment_head(&po->tx_ring); 2129 kfree_skb(skb); 2130 continue; 2131 } else { 2132 status = TP_STATUS_WRONG_FORMAT; 2133 err = tp_len; 2134 goto out_status; 2135 } 2136 } 2137 2138 skb->destructor = tpacket_destruct_skb; 2139 __packet_set_status(po, ph, TP_STATUS_SENDING); 2140 atomic_inc(&po->tx_ring.pending); 2141 2142 status = TP_STATUS_SEND_REQUEST; 2143 err = dev_queue_xmit(skb); 2144 if (unlikely(err > 0)) { 2145 err = net_xmit_errno(err); 2146 if (err && __packet_get_status(po, ph) == 2147 TP_STATUS_AVAILABLE) { 2148 /* skb was destructed already */ 2149 skb = NULL; 2150 goto out_status; 2151 } 2152 /* 2153 * skb was dropped but not destructed yet; 2154 * let's treat it like congestion or err < 0 2155 */ 2156 err = 0; 2157 } 2158 packet_increment_head(&po->tx_ring); 2159 len_sum += tp_len; 2160 } while (likely((ph != NULL) || 2161 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2162 (atomic_read(&po->tx_ring.pending)))) 2163 ); 2164 2165 err = len_sum; 2166 goto out_put; 2167 2168 out_status: 2169 __packet_set_status(po, ph, status); 2170 kfree_skb(skb); 2171 out_put: 2172 if (need_rls_dev) 2173 dev_put(dev); 2174 out: 2175 mutex_unlock(&po->pg_vec_lock); 2176 return err; 2177 } 2178 2179 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2180 size_t reserve, size_t len, 2181 size_t linear, int noblock, 2182 int *err) 2183 { 2184 struct sk_buff *skb; 2185 2186 /* Under a page? Don't bother with paged skb. */ 2187 if (prepad + len < PAGE_SIZE || !linear) 2188 linear = len; 2189 2190 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2191 err); 2192 if (!skb) 2193 return NULL; 2194 2195 skb_reserve(skb, reserve); 2196 skb_put(skb, linear); 2197 skb->data_len = len - linear; 2198 skb->len += len - linear; 2199 2200 return skb; 2201 } 2202 2203 static int packet_snd(struct socket *sock, 2204 struct msghdr *msg, size_t len) 2205 { 2206 struct sock *sk = sock->sk; 2207 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2208 struct sk_buff *skb; 2209 struct net_device *dev; 2210 __be16 proto; 2211 bool need_rls_dev = false; 2212 unsigned char *addr; 2213 int err, reserve = 0; 2214 struct virtio_net_hdr vnet_hdr = { 0 }; 2215 int offset = 0; 2216 int vnet_hdr_len; 2217 struct packet_sock *po = pkt_sk(sk); 2218 unsigned short gso_type = 0; 2219 int hlen, tlen; 2220 int extra_len = 0; 2221 2222 /* 2223 * Get and verify the address. 2224 */ 2225 2226 if (saddr == NULL) { 2227 dev = po->prot_hook.dev; 2228 proto = po->num; 2229 addr = NULL; 2230 } else { 2231 err = -EINVAL; 2232 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2233 goto out; 2234 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2235 goto out; 2236 proto = saddr->sll_protocol; 2237 addr = saddr->sll_addr; 2238 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2239 need_rls_dev = true; 2240 } 2241 2242 err = -ENXIO; 2243 if (dev == NULL) 2244 goto out_unlock; 2245 if (sock->type == SOCK_RAW) 2246 reserve = dev->hard_header_len; 2247 2248 err = -ENETDOWN; 2249 if (!(dev->flags & IFF_UP)) 2250 goto out_unlock; 2251 2252 if (po->has_vnet_hdr) { 2253 vnet_hdr_len = sizeof(vnet_hdr); 2254 2255 err = -EINVAL; 2256 if (len < vnet_hdr_len) 2257 goto out_unlock; 2258 2259 len -= vnet_hdr_len; 2260 2261 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2262 vnet_hdr_len); 2263 if (err < 0) 2264 goto out_unlock; 2265 2266 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2267 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2268 vnet_hdr.hdr_len)) 2269 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2270 vnet_hdr.csum_offset + 2; 2271 2272 err = -EINVAL; 2273 if (vnet_hdr.hdr_len > len) 2274 goto out_unlock; 2275 2276 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2277 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2278 case VIRTIO_NET_HDR_GSO_TCPV4: 2279 gso_type = SKB_GSO_TCPV4; 2280 break; 2281 case VIRTIO_NET_HDR_GSO_TCPV6: 2282 gso_type = SKB_GSO_TCPV6; 2283 break; 2284 case VIRTIO_NET_HDR_GSO_UDP: 2285 gso_type = SKB_GSO_UDP; 2286 break; 2287 default: 2288 goto out_unlock; 2289 } 2290 2291 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2292 gso_type |= SKB_GSO_TCP_ECN; 2293 2294 if (vnet_hdr.gso_size == 0) 2295 goto out_unlock; 2296 2297 } 2298 } 2299 2300 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2301 if (!netif_supports_nofcs(dev)) { 2302 err = -EPROTONOSUPPORT; 2303 goto out_unlock; 2304 } 2305 extra_len = 4; /* We're doing our own CRC */ 2306 } 2307 2308 err = -EMSGSIZE; 2309 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2310 goto out_unlock; 2311 2312 err = -ENOBUFS; 2313 hlen = LL_RESERVED_SPACE(dev); 2314 tlen = dev->needed_tailroom; 2315 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2316 msg->msg_flags & MSG_DONTWAIT, &err); 2317 if (skb == NULL) 2318 goto out_unlock; 2319 2320 skb_set_network_header(skb, reserve); 2321 2322 err = -EINVAL; 2323 if (sock->type == SOCK_DGRAM && 2324 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2325 goto out_free; 2326 2327 /* Returns -EFAULT on error */ 2328 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2329 if (err) 2330 goto out_free; 2331 2332 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2333 2334 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2335 /* Earlier code assumed this would be a VLAN pkt, 2336 * double-check this now that we have the actual 2337 * packet in hand. 2338 */ 2339 struct ethhdr *ehdr; 2340 skb_reset_mac_header(skb); 2341 ehdr = eth_hdr(skb); 2342 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2343 err = -EMSGSIZE; 2344 goto out_free; 2345 } 2346 } 2347 2348 skb->protocol = proto; 2349 skb->dev = dev; 2350 skb->priority = sk->sk_priority; 2351 skb->mark = sk->sk_mark; 2352 2353 if (po->has_vnet_hdr) { 2354 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2355 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2356 vnet_hdr.csum_offset)) { 2357 err = -EINVAL; 2358 goto out_free; 2359 } 2360 } 2361 2362 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2363 skb_shinfo(skb)->gso_type = gso_type; 2364 2365 /* Header must be checked, and gso_segs computed. */ 2366 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2367 skb_shinfo(skb)->gso_segs = 0; 2368 2369 len += vnet_hdr_len; 2370 } 2371 2372 skb_probe_transport_header(skb, reserve); 2373 2374 if (unlikely(extra_len == 4)) 2375 skb->no_fcs = 1; 2376 2377 /* 2378 * Now send it 2379 */ 2380 2381 err = dev_queue_xmit(skb); 2382 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2383 goto out_unlock; 2384 2385 if (need_rls_dev) 2386 dev_put(dev); 2387 2388 return len; 2389 2390 out_free: 2391 kfree_skb(skb); 2392 out_unlock: 2393 if (dev && need_rls_dev) 2394 dev_put(dev); 2395 out: 2396 return err; 2397 } 2398 2399 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2400 struct msghdr *msg, size_t len) 2401 { 2402 struct sock *sk = sock->sk; 2403 struct packet_sock *po = pkt_sk(sk); 2404 if (po->tx_ring.pg_vec) 2405 return tpacket_snd(po, msg); 2406 else 2407 return packet_snd(sock, msg, len); 2408 } 2409 2410 /* 2411 * Close a PACKET socket. This is fairly simple. We immediately go 2412 * to 'closed' state and remove our protocol entry in the device list. 2413 */ 2414 2415 static int packet_release(struct socket *sock) 2416 { 2417 struct sock *sk = sock->sk; 2418 struct packet_sock *po; 2419 struct net *net; 2420 union tpacket_req_u req_u; 2421 2422 if (!sk) 2423 return 0; 2424 2425 net = sock_net(sk); 2426 po = pkt_sk(sk); 2427 2428 mutex_lock(&net->packet.sklist_lock); 2429 sk_del_node_init_rcu(sk); 2430 mutex_unlock(&net->packet.sklist_lock); 2431 2432 preempt_disable(); 2433 sock_prot_inuse_add(net, sk->sk_prot, -1); 2434 preempt_enable(); 2435 2436 spin_lock(&po->bind_lock); 2437 unregister_prot_hook(sk, false); 2438 if (po->prot_hook.dev) { 2439 dev_put(po->prot_hook.dev); 2440 po->prot_hook.dev = NULL; 2441 } 2442 spin_unlock(&po->bind_lock); 2443 2444 packet_flush_mclist(sk); 2445 2446 if (po->rx_ring.pg_vec) { 2447 memset(&req_u, 0, sizeof(req_u)); 2448 packet_set_ring(sk, &req_u, 1, 0); 2449 } 2450 2451 if (po->tx_ring.pg_vec) { 2452 memset(&req_u, 0, sizeof(req_u)); 2453 packet_set_ring(sk, &req_u, 1, 1); 2454 } 2455 2456 fanout_release(sk); 2457 2458 synchronize_net(); 2459 /* 2460 * Now the socket is dead. No more input will appear. 2461 */ 2462 sock_orphan(sk); 2463 sock->sk = NULL; 2464 2465 /* Purge queues */ 2466 2467 skb_queue_purge(&sk->sk_receive_queue); 2468 sk_refcnt_debug_release(sk); 2469 2470 sock_put(sk); 2471 return 0; 2472 } 2473 2474 /* 2475 * Attach a packet hook. 2476 */ 2477 2478 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2479 { 2480 struct packet_sock *po = pkt_sk(sk); 2481 2482 if (po->fanout) { 2483 if (dev) 2484 dev_put(dev); 2485 2486 return -EINVAL; 2487 } 2488 2489 lock_sock(sk); 2490 2491 spin_lock(&po->bind_lock); 2492 unregister_prot_hook(sk, true); 2493 po->num = protocol; 2494 po->prot_hook.type = protocol; 2495 if (po->prot_hook.dev) 2496 dev_put(po->prot_hook.dev); 2497 po->prot_hook.dev = dev; 2498 2499 po->ifindex = dev ? dev->ifindex : 0; 2500 2501 if (protocol == 0) 2502 goto out_unlock; 2503 2504 if (!dev || (dev->flags & IFF_UP)) { 2505 register_prot_hook(sk); 2506 } else { 2507 sk->sk_err = ENETDOWN; 2508 if (!sock_flag(sk, SOCK_DEAD)) 2509 sk->sk_error_report(sk); 2510 } 2511 2512 out_unlock: 2513 spin_unlock(&po->bind_lock); 2514 release_sock(sk); 2515 return 0; 2516 } 2517 2518 /* 2519 * Bind a packet socket to a device 2520 */ 2521 2522 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2523 int addr_len) 2524 { 2525 struct sock *sk = sock->sk; 2526 char name[15]; 2527 struct net_device *dev; 2528 int err = -ENODEV; 2529 2530 /* 2531 * Check legality 2532 */ 2533 2534 if (addr_len != sizeof(struct sockaddr)) 2535 return -EINVAL; 2536 strlcpy(name, uaddr->sa_data, sizeof(name)); 2537 2538 dev = dev_get_by_name(sock_net(sk), name); 2539 if (dev) 2540 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2541 return err; 2542 } 2543 2544 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2545 { 2546 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2547 struct sock *sk = sock->sk; 2548 struct net_device *dev = NULL; 2549 int err; 2550 2551 2552 /* 2553 * Check legality 2554 */ 2555 2556 if (addr_len < sizeof(struct sockaddr_ll)) 2557 return -EINVAL; 2558 if (sll->sll_family != AF_PACKET) 2559 return -EINVAL; 2560 2561 if (sll->sll_ifindex) { 2562 err = -ENODEV; 2563 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2564 if (dev == NULL) 2565 goto out; 2566 } 2567 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2568 2569 out: 2570 return err; 2571 } 2572 2573 static struct proto packet_proto = { 2574 .name = "PACKET", 2575 .owner = THIS_MODULE, 2576 .obj_size = sizeof(struct packet_sock), 2577 }; 2578 2579 /* 2580 * Create a packet of type SOCK_PACKET. 2581 */ 2582 2583 static int packet_create(struct net *net, struct socket *sock, int protocol, 2584 int kern) 2585 { 2586 struct sock *sk; 2587 struct packet_sock *po; 2588 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2589 int err; 2590 2591 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 2592 return -EPERM; 2593 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2594 sock->type != SOCK_PACKET) 2595 return -ESOCKTNOSUPPORT; 2596 2597 sock->state = SS_UNCONNECTED; 2598 2599 err = -ENOBUFS; 2600 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2601 if (sk == NULL) 2602 goto out; 2603 2604 sock->ops = &packet_ops; 2605 if (sock->type == SOCK_PACKET) 2606 sock->ops = &packet_ops_spkt; 2607 2608 sock_init_data(sock, sk); 2609 2610 po = pkt_sk(sk); 2611 sk->sk_family = PF_PACKET; 2612 po->num = proto; 2613 2614 sk->sk_destruct = packet_sock_destruct; 2615 sk_refcnt_debug_inc(sk); 2616 2617 /* 2618 * Attach a protocol block 2619 */ 2620 2621 spin_lock_init(&po->bind_lock); 2622 mutex_init(&po->pg_vec_lock); 2623 po->prot_hook.func = packet_rcv; 2624 2625 if (sock->type == SOCK_PACKET) 2626 po->prot_hook.func = packet_rcv_spkt; 2627 2628 po->prot_hook.af_packet_priv = sk; 2629 2630 if (proto) { 2631 po->prot_hook.type = proto; 2632 register_prot_hook(sk); 2633 } 2634 2635 mutex_lock(&net->packet.sklist_lock); 2636 sk_add_node_rcu(sk, &net->packet.sklist); 2637 mutex_unlock(&net->packet.sklist_lock); 2638 2639 preempt_disable(); 2640 sock_prot_inuse_add(net, &packet_proto, 1); 2641 preempt_enable(); 2642 2643 return 0; 2644 out: 2645 return err; 2646 } 2647 2648 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2649 { 2650 struct sock_exterr_skb *serr; 2651 struct sk_buff *skb, *skb2; 2652 int copied, err; 2653 2654 err = -EAGAIN; 2655 skb = skb_dequeue(&sk->sk_error_queue); 2656 if (skb == NULL) 2657 goto out; 2658 2659 copied = skb->len; 2660 if (copied > len) { 2661 msg->msg_flags |= MSG_TRUNC; 2662 copied = len; 2663 } 2664 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2665 if (err) 2666 goto out_free_skb; 2667 2668 sock_recv_timestamp(msg, sk, skb); 2669 2670 serr = SKB_EXT_ERR(skb); 2671 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2672 sizeof(serr->ee), &serr->ee); 2673 2674 msg->msg_flags |= MSG_ERRQUEUE; 2675 err = copied; 2676 2677 /* Reset and regenerate socket error */ 2678 spin_lock_bh(&sk->sk_error_queue.lock); 2679 sk->sk_err = 0; 2680 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2681 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2682 spin_unlock_bh(&sk->sk_error_queue.lock); 2683 sk->sk_error_report(sk); 2684 } else 2685 spin_unlock_bh(&sk->sk_error_queue.lock); 2686 2687 out_free_skb: 2688 kfree_skb(skb); 2689 out: 2690 return err; 2691 } 2692 2693 /* 2694 * Pull a packet from our receive queue and hand it to the user. 2695 * If necessary we block. 2696 */ 2697 2698 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2699 struct msghdr *msg, size_t len, int flags) 2700 { 2701 struct sock *sk = sock->sk; 2702 struct sk_buff *skb; 2703 int copied, err; 2704 struct sockaddr_ll *sll; 2705 int vnet_hdr_len = 0; 2706 2707 err = -EINVAL; 2708 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2709 goto out; 2710 2711 #if 0 2712 /* What error should we return now? EUNATTACH? */ 2713 if (pkt_sk(sk)->ifindex < 0) 2714 return -ENODEV; 2715 #endif 2716 2717 if (flags & MSG_ERRQUEUE) { 2718 err = packet_recv_error(sk, msg, len); 2719 goto out; 2720 } 2721 2722 /* 2723 * Call the generic datagram receiver. This handles all sorts 2724 * of horrible races and re-entrancy so we can forget about it 2725 * in the protocol layers. 2726 * 2727 * Now it will return ENETDOWN, if device have just gone down, 2728 * but then it will block. 2729 */ 2730 2731 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2732 2733 /* 2734 * An error occurred so return it. Because skb_recv_datagram() 2735 * handles the blocking we don't see and worry about blocking 2736 * retries. 2737 */ 2738 2739 if (skb == NULL) 2740 goto out; 2741 2742 if (pkt_sk(sk)->has_vnet_hdr) { 2743 struct virtio_net_hdr vnet_hdr = { 0 }; 2744 2745 err = -EINVAL; 2746 vnet_hdr_len = sizeof(vnet_hdr); 2747 if (len < vnet_hdr_len) 2748 goto out_free; 2749 2750 len -= vnet_hdr_len; 2751 2752 if (skb_is_gso(skb)) { 2753 struct skb_shared_info *sinfo = skb_shinfo(skb); 2754 2755 /* This is a hint as to how much should be linear. */ 2756 vnet_hdr.hdr_len = skb_headlen(skb); 2757 vnet_hdr.gso_size = sinfo->gso_size; 2758 if (sinfo->gso_type & SKB_GSO_TCPV4) 2759 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2760 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2761 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2762 else if (sinfo->gso_type & SKB_GSO_UDP) 2763 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2764 else if (sinfo->gso_type & SKB_GSO_FCOE) 2765 goto out_free; 2766 else 2767 BUG(); 2768 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2769 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2770 } else 2771 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2772 2773 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2774 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2775 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2776 vnet_hdr.csum_offset = skb->csum_offset; 2777 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2778 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2779 } /* else everything is zero */ 2780 2781 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2782 vnet_hdr_len); 2783 if (err < 0) 2784 goto out_free; 2785 } 2786 2787 /* 2788 * If the address length field is there to be filled in, we fill 2789 * it in now. 2790 */ 2791 2792 sll = &PACKET_SKB_CB(skb)->sa.ll; 2793 if (sock->type == SOCK_PACKET) 2794 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2795 else 2796 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2797 2798 /* 2799 * You lose any data beyond the buffer you gave. If it worries a 2800 * user program they can ask the device for its MTU anyway. 2801 */ 2802 2803 copied = skb->len; 2804 if (copied > len) { 2805 copied = len; 2806 msg->msg_flags |= MSG_TRUNC; 2807 } 2808 2809 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2810 if (err) 2811 goto out_free; 2812 2813 sock_recv_ts_and_drops(msg, sk, skb); 2814 2815 if (msg->msg_name) 2816 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2817 msg->msg_namelen); 2818 2819 if (pkt_sk(sk)->auxdata) { 2820 struct tpacket_auxdata aux; 2821 2822 aux.tp_status = TP_STATUS_USER; 2823 if (skb->ip_summed == CHECKSUM_PARTIAL) 2824 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2825 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2826 aux.tp_snaplen = skb->len; 2827 aux.tp_mac = 0; 2828 aux.tp_net = skb_network_offset(skb); 2829 if (vlan_tx_tag_present(skb)) { 2830 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2831 aux.tp_status |= TP_STATUS_VLAN_VALID; 2832 } else { 2833 aux.tp_vlan_tci = 0; 2834 } 2835 aux.tp_padding = 0; 2836 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2837 } 2838 2839 /* 2840 * Free or return the buffer as appropriate. Again this 2841 * hides all the races and re-entrancy issues from us. 2842 */ 2843 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2844 2845 out_free: 2846 skb_free_datagram(sk, skb); 2847 out: 2848 return err; 2849 } 2850 2851 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2852 int *uaddr_len, int peer) 2853 { 2854 struct net_device *dev; 2855 struct sock *sk = sock->sk; 2856 2857 if (peer) 2858 return -EOPNOTSUPP; 2859 2860 uaddr->sa_family = AF_PACKET; 2861 rcu_read_lock(); 2862 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2863 if (dev) 2864 strncpy(uaddr->sa_data, dev->name, 14); 2865 else 2866 memset(uaddr->sa_data, 0, 14); 2867 rcu_read_unlock(); 2868 *uaddr_len = sizeof(*uaddr); 2869 2870 return 0; 2871 } 2872 2873 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2874 int *uaddr_len, int peer) 2875 { 2876 struct net_device *dev; 2877 struct sock *sk = sock->sk; 2878 struct packet_sock *po = pkt_sk(sk); 2879 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2880 2881 if (peer) 2882 return -EOPNOTSUPP; 2883 2884 sll->sll_family = AF_PACKET; 2885 sll->sll_ifindex = po->ifindex; 2886 sll->sll_protocol = po->num; 2887 sll->sll_pkttype = 0; 2888 rcu_read_lock(); 2889 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2890 if (dev) { 2891 sll->sll_hatype = dev->type; 2892 sll->sll_halen = dev->addr_len; 2893 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2894 } else { 2895 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2896 sll->sll_halen = 0; 2897 } 2898 rcu_read_unlock(); 2899 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2900 2901 return 0; 2902 } 2903 2904 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2905 int what) 2906 { 2907 switch (i->type) { 2908 case PACKET_MR_MULTICAST: 2909 if (i->alen != dev->addr_len) 2910 return -EINVAL; 2911 if (what > 0) 2912 return dev_mc_add(dev, i->addr); 2913 else 2914 return dev_mc_del(dev, i->addr); 2915 break; 2916 case PACKET_MR_PROMISC: 2917 return dev_set_promiscuity(dev, what); 2918 break; 2919 case PACKET_MR_ALLMULTI: 2920 return dev_set_allmulti(dev, what); 2921 break; 2922 case PACKET_MR_UNICAST: 2923 if (i->alen != dev->addr_len) 2924 return -EINVAL; 2925 if (what > 0) 2926 return dev_uc_add(dev, i->addr); 2927 else 2928 return dev_uc_del(dev, i->addr); 2929 break; 2930 default: 2931 break; 2932 } 2933 return 0; 2934 } 2935 2936 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2937 { 2938 for ( ; i; i = i->next) { 2939 if (i->ifindex == dev->ifindex) 2940 packet_dev_mc(dev, i, what); 2941 } 2942 } 2943 2944 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2945 { 2946 struct packet_sock *po = pkt_sk(sk); 2947 struct packet_mclist *ml, *i; 2948 struct net_device *dev; 2949 int err; 2950 2951 rtnl_lock(); 2952 2953 err = -ENODEV; 2954 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2955 if (!dev) 2956 goto done; 2957 2958 err = -EINVAL; 2959 if (mreq->mr_alen > dev->addr_len) 2960 goto done; 2961 2962 err = -ENOBUFS; 2963 i = kmalloc(sizeof(*i), GFP_KERNEL); 2964 if (i == NULL) 2965 goto done; 2966 2967 err = 0; 2968 for (ml = po->mclist; ml; ml = ml->next) { 2969 if (ml->ifindex == mreq->mr_ifindex && 2970 ml->type == mreq->mr_type && 2971 ml->alen == mreq->mr_alen && 2972 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2973 ml->count++; 2974 /* Free the new element ... */ 2975 kfree(i); 2976 goto done; 2977 } 2978 } 2979 2980 i->type = mreq->mr_type; 2981 i->ifindex = mreq->mr_ifindex; 2982 i->alen = mreq->mr_alen; 2983 memcpy(i->addr, mreq->mr_address, i->alen); 2984 i->count = 1; 2985 i->next = po->mclist; 2986 po->mclist = i; 2987 err = packet_dev_mc(dev, i, 1); 2988 if (err) { 2989 po->mclist = i->next; 2990 kfree(i); 2991 } 2992 2993 done: 2994 rtnl_unlock(); 2995 return err; 2996 } 2997 2998 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2999 { 3000 struct packet_mclist *ml, **mlp; 3001 3002 rtnl_lock(); 3003 3004 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3005 if (ml->ifindex == mreq->mr_ifindex && 3006 ml->type == mreq->mr_type && 3007 ml->alen == mreq->mr_alen && 3008 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3009 if (--ml->count == 0) { 3010 struct net_device *dev; 3011 *mlp = ml->next; 3012 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3013 if (dev) 3014 packet_dev_mc(dev, ml, -1); 3015 kfree(ml); 3016 } 3017 rtnl_unlock(); 3018 return 0; 3019 } 3020 } 3021 rtnl_unlock(); 3022 return -EADDRNOTAVAIL; 3023 } 3024 3025 static void packet_flush_mclist(struct sock *sk) 3026 { 3027 struct packet_sock *po = pkt_sk(sk); 3028 struct packet_mclist *ml; 3029 3030 if (!po->mclist) 3031 return; 3032 3033 rtnl_lock(); 3034 while ((ml = po->mclist) != NULL) { 3035 struct net_device *dev; 3036 3037 po->mclist = ml->next; 3038 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3039 if (dev != NULL) 3040 packet_dev_mc(dev, ml, -1); 3041 kfree(ml); 3042 } 3043 rtnl_unlock(); 3044 } 3045 3046 static int 3047 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3048 { 3049 struct sock *sk = sock->sk; 3050 struct packet_sock *po = pkt_sk(sk); 3051 int ret; 3052 3053 if (level != SOL_PACKET) 3054 return -ENOPROTOOPT; 3055 3056 switch (optname) { 3057 case PACKET_ADD_MEMBERSHIP: 3058 case PACKET_DROP_MEMBERSHIP: 3059 { 3060 struct packet_mreq_max mreq; 3061 int len = optlen; 3062 memset(&mreq, 0, sizeof(mreq)); 3063 if (len < sizeof(struct packet_mreq)) 3064 return -EINVAL; 3065 if (len > sizeof(mreq)) 3066 len = sizeof(mreq); 3067 if (copy_from_user(&mreq, optval, len)) 3068 return -EFAULT; 3069 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3070 return -EINVAL; 3071 if (optname == PACKET_ADD_MEMBERSHIP) 3072 ret = packet_mc_add(sk, &mreq); 3073 else 3074 ret = packet_mc_drop(sk, &mreq); 3075 return ret; 3076 } 3077 3078 case PACKET_RX_RING: 3079 case PACKET_TX_RING: 3080 { 3081 union tpacket_req_u req_u; 3082 int len; 3083 3084 switch (po->tp_version) { 3085 case TPACKET_V1: 3086 case TPACKET_V2: 3087 len = sizeof(req_u.req); 3088 break; 3089 case TPACKET_V3: 3090 default: 3091 len = sizeof(req_u.req3); 3092 break; 3093 } 3094 if (optlen < len) 3095 return -EINVAL; 3096 if (pkt_sk(sk)->has_vnet_hdr) 3097 return -EINVAL; 3098 if (copy_from_user(&req_u.req, optval, len)) 3099 return -EFAULT; 3100 return packet_set_ring(sk, &req_u, 0, 3101 optname == PACKET_TX_RING); 3102 } 3103 case PACKET_COPY_THRESH: 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 pkt_sk(sk)->copy_thresh = val; 3113 return 0; 3114 } 3115 case PACKET_VERSION: 3116 { 3117 int val; 3118 3119 if (optlen != sizeof(val)) 3120 return -EINVAL; 3121 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3122 return -EBUSY; 3123 if (copy_from_user(&val, optval, sizeof(val))) 3124 return -EFAULT; 3125 switch (val) { 3126 case TPACKET_V1: 3127 case TPACKET_V2: 3128 case TPACKET_V3: 3129 po->tp_version = val; 3130 return 0; 3131 default: 3132 return -EINVAL; 3133 } 3134 } 3135 case PACKET_RESERVE: 3136 { 3137 unsigned int val; 3138 3139 if (optlen != sizeof(val)) 3140 return -EINVAL; 3141 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3142 return -EBUSY; 3143 if (copy_from_user(&val, optval, sizeof(val))) 3144 return -EFAULT; 3145 po->tp_reserve = val; 3146 return 0; 3147 } 3148 case PACKET_LOSS: 3149 { 3150 unsigned int val; 3151 3152 if (optlen != sizeof(val)) 3153 return -EINVAL; 3154 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3155 return -EBUSY; 3156 if (copy_from_user(&val, optval, sizeof(val))) 3157 return -EFAULT; 3158 po->tp_loss = !!val; 3159 return 0; 3160 } 3161 case PACKET_AUXDATA: 3162 { 3163 int val; 3164 3165 if (optlen < sizeof(val)) 3166 return -EINVAL; 3167 if (copy_from_user(&val, optval, sizeof(val))) 3168 return -EFAULT; 3169 3170 po->auxdata = !!val; 3171 return 0; 3172 } 3173 case PACKET_ORIGDEV: 3174 { 3175 int val; 3176 3177 if (optlen < sizeof(val)) 3178 return -EINVAL; 3179 if (copy_from_user(&val, optval, sizeof(val))) 3180 return -EFAULT; 3181 3182 po->origdev = !!val; 3183 return 0; 3184 } 3185 case PACKET_VNET_HDR: 3186 { 3187 int val; 3188 3189 if (sock->type != SOCK_RAW) 3190 return -EINVAL; 3191 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3192 return -EBUSY; 3193 if (optlen < sizeof(val)) 3194 return -EINVAL; 3195 if (copy_from_user(&val, optval, sizeof(val))) 3196 return -EFAULT; 3197 3198 po->has_vnet_hdr = !!val; 3199 return 0; 3200 } 3201 case PACKET_TIMESTAMP: 3202 { 3203 int val; 3204 3205 if (optlen != sizeof(val)) 3206 return -EINVAL; 3207 if (copy_from_user(&val, optval, sizeof(val))) 3208 return -EFAULT; 3209 3210 po->tp_tstamp = val; 3211 return 0; 3212 } 3213 case PACKET_FANOUT: 3214 { 3215 int val; 3216 3217 if (optlen != sizeof(val)) 3218 return -EINVAL; 3219 if (copy_from_user(&val, optval, sizeof(val))) 3220 return -EFAULT; 3221 3222 return fanout_add(sk, val & 0xffff, val >> 16); 3223 } 3224 case PACKET_TX_HAS_OFF: 3225 { 3226 unsigned int val; 3227 3228 if (optlen != sizeof(val)) 3229 return -EINVAL; 3230 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3231 return -EBUSY; 3232 if (copy_from_user(&val, optval, sizeof(val))) 3233 return -EFAULT; 3234 po->tp_tx_has_off = !!val; 3235 return 0; 3236 } 3237 default: 3238 return -ENOPROTOOPT; 3239 } 3240 } 3241 3242 static int packet_getsockopt(struct socket *sock, int level, int optname, 3243 char __user *optval, int __user *optlen) 3244 { 3245 int len; 3246 int val, lv = sizeof(val); 3247 struct sock *sk = sock->sk; 3248 struct packet_sock *po = pkt_sk(sk); 3249 void *data = &val; 3250 union tpacket_stats_u st; 3251 3252 if (level != SOL_PACKET) 3253 return -ENOPROTOOPT; 3254 3255 if (get_user(len, optlen)) 3256 return -EFAULT; 3257 3258 if (len < 0) 3259 return -EINVAL; 3260 3261 switch (optname) { 3262 case PACKET_STATISTICS: 3263 spin_lock_bh(&sk->sk_receive_queue.lock); 3264 memcpy(&st, &po->stats, sizeof(st)); 3265 memset(&po->stats, 0, sizeof(po->stats)); 3266 spin_unlock_bh(&sk->sk_receive_queue.lock); 3267 3268 if (po->tp_version == TPACKET_V3) { 3269 lv = sizeof(struct tpacket_stats_v3); 3270 data = &st.stats3; 3271 } else { 3272 lv = sizeof(struct tpacket_stats); 3273 data = &st.stats1; 3274 } 3275 3276 break; 3277 case PACKET_AUXDATA: 3278 val = po->auxdata; 3279 break; 3280 case PACKET_ORIGDEV: 3281 val = po->origdev; 3282 break; 3283 case PACKET_VNET_HDR: 3284 val = po->has_vnet_hdr; 3285 break; 3286 case PACKET_VERSION: 3287 val = po->tp_version; 3288 break; 3289 case PACKET_HDRLEN: 3290 if (len > sizeof(int)) 3291 len = sizeof(int); 3292 if (copy_from_user(&val, optval, len)) 3293 return -EFAULT; 3294 switch (val) { 3295 case TPACKET_V1: 3296 val = sizeof(struct tpacket_hdr); 3297 break; 3298 case TPACKET_V2: 3299 val = sizeof(struct tpacket2_hdr); 3300 break; 3301 case TPACKET_V3: 3302 val = sizeof(struct tpacket3_hdr); 3303 break; 3304 default: 3305 return -EINVAL; 3306 } 3307 break; 3308 case PACKET_RESERVE: 3309 val = po->tp_reserve; 3310 break; 3311 case PACKET_LOSS: 3312 val = po->tp_loss; 3313 break; 3314 case PACKET_TIMESTAMP: 3315 val = po->tp_tstamp; 3316 break; 3317 case PACKET_FANOUT: 3318 val = (po->fanout ? 3319 ((u32)po->fanout->id | 3320 ((u32)po->fanout->type << 16) | 3321 ((u32)po->fanout->flags << 24)) : 3322 0); 3323 break; 3324 case PACKET_TX_HAS_OFF: 3325 val = po->tp_tx_has_off; 3326 break; 3327 default: 3328 return -ENOPROTOOPT; 3329 } 3330 3331 if (len > lv) 3332 len = lv; 3333 if (put_user(len, optlen)) 3334 return -EFAULT; 3335 if (copy_to_user(optval, data, len)) 3336 return -EFAULT; 3337 return 0; 3338 } 3339 3340 3341 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3342 { 3343 struct sock *sk; 3344 struct net_device *dev = data; 3345 struct net *net = dev_net(dev); 3346 3347 rcu_read_lock(); 3348 sk_for_each_rcu(sk, &net->packet.sklist) { 3349 struct packet_sock *po = pkt_sk(sk); 3350 3351 switch (msg) { 3352 case NETDEV_UNREGISTER: 3353 if (po->mclist) 3354 packet_dev_mclist(dev, po->mclist, -1); 3355 /* fallthrough */ 3356 3357 case NETDEV_DOWN: 3358 if (dev->ifindex == po->ifindex) { 3359 spin_lock(&po->bind_lock); 3360 if (po->running) { 3361 __unregister_prot_hook(sk, false); 3362 sk->sk_err = ENETDOWN; 3363 if (!sock_flag(sk, SOCK_DEAD)) 3364 sk->sk_error_report(sk); 3365 } 3366 if (msg == NETDEV_UNREGISTER) { 3367 po->ifindex = -1; 3368 if (po->prot_hook.dev) 3369 dev_put(po->prot_hook.dev); 3370 po->prot_hook.dev = NULL; 3371 } 3372 spin_unlock(&po->bind_lock); 3373 } 3374 break; 3375 case NETDEV_UP: 3376 if (dev->ifindex == po->ifindex) { 3377 spin_lock(&po->bind_lock); 3378 if (po->num) 3379 register_prot_hook(sk); 3380 spin_unlock(&po->bind_lock); 3381 } 3382 break; 3383 } 3384 } 3385 rcu_read_unlock(); 3386 return NOTIFY_DONE; 3387 } 3388 3389 3390 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3391 unsigned long arg) 3392 { 3393 struct sock *sk = sock->sk; 3394 3395 switch (cmd) { 3396 case SIOCOUTQ: 3397 { 3398 int amount = sk_wmem_alloc_get(sk); 3399 3400 return put_user(amount, (int __user *)arg); 3401 } 3402 case SIOCINQ: 3403 { 3404 struct sk_buff *skb; 3405 int amount = 0; 3406 3407 spin_lock_bh(&sk->sk_receive_queue.lock); 3408 skb = skb_peek(&sk->sk_receive_queue); 3409 if (skb) 3410 amount = skb->len; 3411 spin_unlock_bh(&sk->sk_receive_queue.lock); 3412 return put_user(amount, (int __user *)arg); 3413 } 3414 case SIOCGSTAMP: 3415 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3416 case SIOCGSTAMPNS: 3417 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3418 3419 #ifdef CONFIG_INET 3420 case SIOCADDRT: 3421 case SIOCDELRT: 3422 case SIOCDARP: 3423 case SIOCGARP: 3424 case SIOCSARP: 3425 case SIOCGIFADDR: 3426 case SIOCSIFADDR: 3427 case SIOCGIFBRDADDR: 3428 case SIOCSIFBRDADDR: 3429 case SIOCGIFNETMASK: 3430 case SIOCSIFNETMASK: 3431 case SIOCGIFDSTADDR: 3432 case SIOCSIFDSTADDR: 3433 case SIOCSIFFLAGS: 3434 return inet_dgram_ops.ioctl(sock, cmd, arg); 3435 #endif 3436 3437 default: 3438 return -ENOIOCTLCMD; 3439 } 3440 return 0; 3441 } 3442 3443 static unsigned int packet_poll(struct file *file, struct socket *sock, 3444 poll_table *wait) 3445 { 3446 struct sock *sk = sock->sk; 3447 struct packet_sock *po = pkt_sk(sk); 3448 unsigned int mask = datagram_poll(file, sock, wait); 3449 3450 spin_lock_bh(&sk->sk_receive_queue.lock); 3451 if (po->rx_ring.pg_vec) { 3452 if (!packet_previous_rx_frame(po, &po->rx_ring, 3453 TP_STATUS_KERNEL)) 3454 mask |= POLLIN | POLLRDNORM; 3455 } 3456 spin_unlock_bh(&sk->sk_receive_queue.lock); 3457 spin_lock_bh(&sk->sk_write_queue.lock); 3458 if (po->tx_ring.pg_vec) { 3459 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3460 mask |= POLLOUT | POLLWRNORM; 3461 } 3462 spin_unlock_bh(&sk->sk_write_queue.lock); 3463 return mask; 3464 } 3465 3466 3467 /* Dirty? Well, I still did not learn better way to account 3468 * for user mmaps. 3469 */ 3470 3471 static void packet_mm_open(struct vm_area_struct *vma) 3472 { 3473 struct file *file = vma->vm_file; 3474 struct socket *sock = file->private_data; 3475 struct sock *sk = sock->sk; 3476 3477 if (sk) 3478 atomic_inc(&pkt_sk(sk)->mapped); 3479 } 3480 3481 static void packet_mm_close(struct vm_area_struct *vma) 3482 { 3483 struct file *file = vma->vm_file; 3484 struct socket *sock = file->private_data; 3485 struct sock *sk = sock->sk; 3486 3487 if (sk) 3488 atomic_dec(&pkt_sk(sk)->mapped); 3489 } 3490 3491 static const struct vm_operations_struct packet_mmap_ops = { 3492 .open = packet_mm_open, 3493 .close = packet_mm_close, 3494 }; 3495 3496 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3497 unsigned int len) 3498 { 3499 int i; 3500 3501 for (i = 0; i < len; i++) { 3502 if (likely(pg_vec[i].buffer)) { 3503 if (is_vmalloc_addr(pg_vec[i].buffer)) 3504 vfree(pg_vec[i].buffer); 3505 else 3506 free_pages((unsigned long)pg_vec[i].buffer, 3507 order); 3508 pg_vec[i].buffer = NULL; 3509 } 3510 } 3511 kfree(pg_vec); 3512 } 3513 3514 static char *alloc_one_pg_vec_page(unsigned long order) 3515 { 3516 char *buffer = NULL; 3517 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3518 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3519 3520 buffer = (char *) __get_free_pages(gfp_flags, order); 3521 3522 if (buffer) 3523 return buffer; 3524 3525 /* 3526 * __get_free_pages failed, fall back to vmalloc 3527 */ 3528 buffer = vzalloc((1 << order) * PAGE_SIZE); 3529 3530 if (buffer) 3531 return buffer; 3532 3533 /* 3534 * vmalloc failed, lets dig into swap here 3535 */ 3536 gfp_flags &= ~__GFP_NORETRY; 3537 buffer = (char *)__get_free_pages(gfp_flags, order); 3538 if (buffer) 3539 return buffer; 3540 3541 /* 3542 * complete and utter failure 3543 */ 3544 return NULL; 3545 } 3546 3547 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3548 { 3549 unsigned int block_nr = req->tp_block_nr; 3550 struct pgv *pg_vec; 3551 int i; 3552 3553 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3554 if (unlikely(!pg_vec)) 3555 goto out; 3556 3557 for (i = 0; i < block_nr; i++) { 3558 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3559 if (unlikely(!pg_vec[i].buffer)) 3560 goto out_free_pgvec; 3561 } 3562 3563 out: 3564 return pg_vec; 3565 3566 out_free_pgvec: 3567 free_pg_vec(pg_vec, order, block_nr); 3568 pg_vec = NULL; 3569 goto out; 3570 } 3571 3572 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3573 int closing, int tx_ring) 3574 { 3575 struct pgv *pg_vec = NULL; 3576 struct packet_sock *po = pkt_sk(sk); 3577 int was_running, order = 0; 3578 struct packet_ring_buffer *rb; 3579 struct sk_buff_head *rb_queue; 3580 __be16 num; 3581 int err = -EINVAL; 3582 /* Added to avoid minimal code churn */ 3583 struct tpacket_req *req = &req_u->req; 3584 3585 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3586 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3587 WARN(1, "Tx-ring is not supported.\n"); 3588 goto out; 3589 } 3590 3591 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3592 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3593 3594 err = -EBUSY; 3595 if (!closing) { 3596 if (atomic_read(&po->mapped)) 3597 goto out; 3598 if (atomic_read(&rb->pending)) 3599 goto out; 3600 } 3601 3602 if (req->tp_block_nr) { 3603 /* Sanity tests and some calculations */ 3604 err = -EBUSY; 3605 if (unlikely(rb->pg_vec)) 3606 goto out; 3607 3608 switch (po->tp_version) { 3609 case TPACKET_V1: 3610 po->tp_hdrlen = TPACKET_HDRLEN; 3611 break; 3612 case TPACKET_V2: 3613 po->tp_hdrlen = TPACKET2_HDRLEN; 3614 break; 3615 case TPACKET_V3: 3616 po->tp_hdrlen = TPACKET3_HDRLEN; 3617 break; 3618 } 3619 3620 err = -EINVAL; 3621 if (unlikely((int)req->tp_block_size <= 0)) 3622 goto out; 3623 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3624 goto out; 3625 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3626 po->tp_reserve)) 3627 goto out; 3628 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3629 goto out; 3630 3631 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3632 if (unlikely(rb->frames_per_block <= 0)) 3633 goto out; 3634 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3635 req->tp_frame_nr)) 3636 goto out; 3637 3638 err = -ENOMEM; 3639 order = get_order(req->tp_block_size); 3640 pg_vec = alloc_pg_vec(req, order); 3641 if (unlikely(!pg_vec)) 3642 goto out; 3643 switch (po->tp_version) { 3644 case TPACKET_V3: 3645 /* Transmit path is not supported. We checked 3646 * it above but just being paranoid 3647 */ 3648 if (!tx_ring) 3649 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3650 break; 3651 default: 3652 break; 3653 } 3654 } 3655 /* Done */ 3656 else { 3657 err = -EINVAL; 3658 if (unlikely(req->tp_frame_nr)) 3659 goto out; 3660 } 3661 3662 lock_sock(sk); 3663 3664 /* Detach socket from network */ 3665 spin_lock(&po->bind_lock); 3666 was_running = po->running; 3667 num = po->num; 3668 if (was_running) { 3669 po->num = 0; 3670 __unregister_prot_hook(sk, false); 3671 } 3672 spin_unlock(&po->bind_lock); 3673 3674 synchronize_net(); 3675 3676 err = -EBUSY; 3677 mutex_lock(&po->pg_vec_lock); 3678 if (closing || atomic_read(&po->mapped) == 0) { 3679 err = 0; 3680 spin_lock_bh(&rb_queue->lock); 3681 swap(rb->pg_vec, pg_vec); 3682 rb->frame_max = (req->tp_frame_nr - 1); 3683 rb->head = 0; 3684 rb->frame_size = req->tp_frame_size; 3685 spin_unlock_bh(&rb_queue->lock); 3686 3687 swap(rb->pg_vec_order, order); 3688 swap(rb->pg_vec_len, req->tp_block_nr); 3689 3690 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3691 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3692 tpacket_rcv : packet_rcv; 3693 skb_queue_purge(rb_queue); 3694 if (atomic_read(&po->mapped)) 3695 pr_err("packet_mmap: vma is busy: %d\n", 3696 atomic_read(&po->mapped)); 3697 } 3698 mutex_unlock(&po->pg_vec_lock); 3699 3700 spin_lock(&po->bind_lock); 3701 if (was_running) { 3702 po->num = num; 3703 register_prot_hook(sk); 3704 } 3705 spin_unlock(&po->bind_lock); 3706 if (closing && (po->tp_version > TPACKET_V2)) { 3707 /* Because we don't support block-based V3 on tx-ring */ 3708 if (!tx_ring) 3709 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3710 } 3711 release_sock(sk); 3712 3713 if (pg_vec) 3714 free_pg_vec(pg_vec, order, req->tp_block_nr); 3715 out: 3716 return err; 3717 } 3718 3719 static int packet_mmap(struct file *file, struct socket *sock, 3720 struct vm_area_struct *vma) 3721 { 3722 struct sock *sk = sock->sk; 3723 struct packet_sock *po = pkt_sk(sk); 3724 unsigned long size, expected_size; 3725 struct packet_ring_buffer *rb; 3726 unsigned long start; 3727 int err = -EINVAL; 3728 int i; 3729 3730 if (vma->vm_pgoff) 3731 return -EINVAL; 3732 3733 mutex_lock(&po->pg_vec_lock); 3734 3735 expected_size = 0; 3736 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3737 if (rb->pg_vec) { 3738 expected_size += rb->pg_vec_len 3739 * rb->pg_vec_pages 3740 * PAGE_SIZE; 3741 } 3742 } 3743 3744 if (expected_size == 0) 3745 goto out; 3746 3747 size = vma->vm_end - vma->vm_start; 3748 if (size != expected_size) 3749 goto out; 3750 3751 start = vma->vm_start; 3752 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3753 if (rb->pg_vec == NULL) 3754 continue; 3755 3756 for (i = 0; i < rb->pg_vec_len; i++) { 3757 struct page *page; 3758 void *kaddr = rb->pg_vec[i].buffer; 3759 int pg_num; 3760 3761 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3762 page = pgv_to_page(kaddr); 3763 err = vm_insert_page(vma, start, page); 3764 if (unlikely(err)) 3765 goto out; 3766 start += PAGE_SIZE; 3767 kaddr += PAGE_SIZE; 3768 } 3769 } 3770 } 3771 3772 atomic_inc(&po->mapped); 3773 vma->vm_ops = &packet_mmap_ops; 3774 err = 0; 3775 3776 out: 3777 mutex_unlock(&po->pg_vec_lock); 3778 return err; 3779 } 3780 3781 static const struct proto_ops packet_ops_spkt = { 3782 .family = PF_PACKET, 3783 .owner = THIS_MODULE, 3784 .release = packet_release, 3785 .bind = packet_bind_spkt, 3786 .connect = sock_no_connect, 3787 .socketpair = sock_no_socketpair, 3788 .accept = sock_no_accept, 3789 .getname = packet_getname_spkt, 3790 .poll = datagram_poll, 3791 .ioctl = packet_ioctl, 3792 .listen = sock_no_listen, 3793 .shutdown = sock_no_shutdown, 3794 .setsockopt = sock_no_setsockopt, 3795 .getsockopt = sock_no_getsockopt, 3796 .sendmsg = packet_sendmsg_spkt, 3797 .recvmsg = packet_recvmsg, 3798 .mmap = sock_no_mmap, 3799 .sendpage = sock_no_sendpage, 3800 }; 3801 3802 static const struct proto_ops packet_ops = { 3803 .family = PF_PACKET, 3804 .owner = THIS_MODULE, 3805 .release = packet_release, 3806 .bind = packet_bind, 3807 .connect = sock_no_connect, 3808 .socketpair = sock_no_socketpair, 3809 .accept = sock_no_accept, 3810 .getname = packet_getname, 3811 .poll = packet_poll, 3812 .ioctl = packet_ioctl, 3813 .listen = sock_no_listen, 3814 .shutdown = sock_no_shutdown, 3815 .setsockopt = packet_setsockopt, 3816 .getsockopt = packet_getsockopt, 3817 .sendmsg = packet_sendmsg, 3818 .recvmsg = packet_recvmsg, 3819 .mmap = packet_mmap, 3820 .sendpage = sock_no_sendpage, 3821 }; 3822 3823 static const struct net_proto_family packet_family_ops = { 3824 .family = PF_PACKET, 3825 .create = packet_create, 3826 .owner = THIS_MODULE, 3827 }; 3828 3829 static struct notifier_block packet_netdev_notifier = { 3830 .notifier_call = packet_notifier, 3831 }; 3832 3833 #ifdef CONFIG_PROC_FS 3834 3835 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3836 __acquires(RCU) 3837 { 3838 struct net *net = seq_file_net(seq); 3839 3840 rcu_read_lock(); 3841 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3842 } 3843 3844 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3845 { 3846 struct net *net = seq_file_net(seq); 3847 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3848 } 3849 3850 static void packet_seq_stop(struct seq_file *seq, void *v) 3851 __releases(RCU) 3852 { 3853 rcu_read_unlock(); 3854 } 3855 3856 static int packet_seq_show(struct seq_file *seq, void *v) 3857 { 3858 if (v == SEQ_START_TOKEN) 3859 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3860 else { 3861 struct sock *s = sk_entry(v); 3862 const struct packet_sock *po = pkt_sk(s); 3863 3864 seq_printf(seq, 3865 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3866 s, 3867 atomic_read(&s->sk_refcnt), 3868 s->sk_type, 3869 ntohs(po->num), 3870 po->ifindex, 3871 po->running, 3872 atomic_read(&s->sk_rmem_alloc), 3873 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 3874 sock_i_ino(s)); 3875 } 3876 3877 return 0; 3878 } 3879 3880 static const struct seq_operations packet_seq_ops = { 3881 .start = packet_seq_start, 3882 .next = packet_seq_next, 3883 .stop = packet_seq_stop, 3884 .show = packet_seq_show, 3885 }; 3886 3887 static int packet_seq_open(struct inode *inode, struct file *file) 3888 { 3889 return seq_open_net(inode, file, &packet_seq_ops, 3890 sizeof(struct seq_net_private)); 3891 } 3892 3893 static const struct file_operations packet_seq_fops = { 3894 .owner = THIS_MODULE, 3895 .open = packet_seq_open, 3896 .read = seq_read, 3897 .llseek = seq_lseek, 3898 .release = seq_release_net, 3899 }; 3900 3901 #endif 3902 3903 static int __net_init packet_net_init(struct net *net) 3904 { 3905 mutex_init(&net->packet.sklist_lock); 3906 INIT_HLIST_HEAD(&net->packet.sklist); 3907 3908 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 3909 return -ENOMEM; 3910 3911 return 0; 3912 } 3913 3914 static void __net_exit packet_net_exit(struct net *net) 3915 { 3916 remove_proc_entry("packet", net->proc_net); 3917 } 3918 3919 static struct pernet_operations packet_net_ops = { 3920 .init = packet_net_init, 3921 .exit = packet_net_exit, 3922 }; 3923 3924 3925 static void __exit packet_exit(void) 3926 { 3927 unregister_netdevice_notifier(&packet_netdev_notifier); 3928 unregister_pernet_subsys(&packet_net_ops); 3929 sock_unregister(PF_PACKET); 3930 proto_unregister(&packet_proto); 3931 } 3932 3933 static int __init packet_init(void) 3934 { 3935 int rc = proto_register(&packet_proto, 0); 3936 3937 if (rc != 0) 3938 goto out; 3939 3940 sock_register(&packet_family_ops); 3941 register_pernet_subsys(&packet_net_ops); 3942 register_netdevice_notifier(&packet_netdev_notifier); 3943 out: 3944 return rc; 3945 } 3946 3947 module_init(packet_init); 3948 module_exit(packet_exit); 3949 MODULE_LICENSE("GPL"); 3950 MODULE_ALIAS_NETPROTO(PF_PACKET); 3951