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 /* We could have just memset this but we will lose the 746 * flexibility of making the priv area sticky 747 */ 748 749 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 750 BLOCK_NUM_PKTS(pbd1) = 0; 751 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 752 753 getnstimeofday(&ts); 754 755 h1->ts_first_pkt.ts_sec = ts.tv_sec; 756 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 757 758 pkc1->pkblk_start = (char *)pbd1; 759 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 760 761 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 762 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 763 764 pbd1->version = pkc1->version; 765 pkc1->prev = pkc1->nxt_offset; 766 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 767 768 prb_thaw_queue(pkc1); 769 _prb_refresh_rx_retire_blk_timer(pkc1); 770 771 smp_wmb(); 772 } 773 774 /* 775 * Queue freeze logic: 776 * 1) Assume tp_block_nr = 8 blocks. 777 * 2) At time 't0', user opens Rx ring. 778 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 779 * 4) user-space is either sleeping or processing block '0'. 780 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 781 * it will close block-7,loop around and try to fill block '0'. 782 * call-flow: 783 * __packet_lookup_frame_in_block 784 * prb_retire_current_block() 785 * prb_dispatch_next_block() 786 * |->(BLOCK_STATUS == USER) evaluates to true 787 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 788 * 6) Now there are two cases: 789 * 6.1) Link goes idle right after the queue is frozen. 790 * But remember, the last open_block() refreshed the timer. 791 * When this timer expires,it will refresh itself so that we can 792 * re-open block-0 in near future. 793 * 6.2) Link is busy and keeps on receiving packets. This is a simple 794 * case and __packet_lookup_frame_in_block will check if block-0 795 * is free and can now be re-used. 796 */ 797 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 798 struct packet_sock *po) 799 { 800 pkc->reset_pending_on_curr_blk = 1; 801 po->stats.stats3.tp_freeze_q_cnt++; 802 } 803 804 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 805 806 /* 807 * If the next block is free then we will dispatch it 808 * and return a good offset. 809 * Else, we will freeze the queue. 810 * So, caller must check the return value. 811 */ 812 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 813 struct packet_sock *po) 814 { 815 struct tpacket_block_desc *pbd; 816 817 smp_rmb(); 818 819 /* 1. Get current block num */ 820 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 821 822 /* 2. If this block is currently in_use then freeze the queue */ 823 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 824 prb_freeze_queue(pkc, po); 825 return NULL; 826 } 827 828 /* 829 * 3. 830 * open this block and return the offset where the first packet 831 * needs to get stored. 832 */ 833 prb_open_block(pkc, pbd); 834 return (void *)pkc->nxt_offset; 835 } 836 837 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 838 struct packet_sock *po, unsigned int status) 839 { 840 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 841 842 /* retire/close the current block */ 843 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 844 /* 845 * Plug the case where copy_bits() is in progress on 846 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 847 * have space to copy the pkt in the current block and 848 * called prb_retire_current_block() 849 * 850 * We don't need to worry about the TMO case because 851 * the timer-handler already handled this case. 852 */ 853 if (!(status & TP_STATUS_BLK_TMO)) { 854 while (atomic_read(&pkc->blk_fill_in_prog)) { 855 /* Waiting for skb_copy_bits to finish... */ 856 cpu_relax(); 857 } 858 } 859 prb_close_block(pkc, pbd, po, status); 860 return; 861 } 862 } 863 864 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 865 struct tpacket_block_desc *pbd) 866 { 867 return TP_STATUS_USER & BLOCK_STATUS(pbd); 868 } 869 870 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 871 { 872 return pkc->reset_pending_on_curr_blk; 873 } 874 875 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 876 { 877 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 878 atomic_dec(&pkc->blk_fill_in_prog); 879 } 880 881 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 882 struct tpacket3_hdr *ppd) 883 { 884 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 885 } 886 887 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 888 struct tpacket3_hdr *ppd) 889 { 890 ppd->hv1.tp_rxhash = 0; 891 } 892 893 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 894 struct tpacket3_hdr *ppd) 895 { 896 if (vlan_tx_tag_present(pkc->skb)) { 897 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 898 ppd->tp_status = TP_STATUS_VLAN_VALID; 899 } else { 900 ppd->hv1.tp_vlan_tci = 0; 901 ppd->tp_status = TP_STATUS_AVAILABLE; 902 } 903 } 904 905 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 906 struct tpacket3_hdr *ppd) 907 { 908 prb_fill_vlan_info(pkc, ppd); 909 910 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 911 prb_fill_rxhash(pkc, ppd); 912 else 913 prb_clear_rxhash(pkc, ppd); 914 } 915 916 static void prb_fill_curr_block(char *curr, 917 struct tpacket_kbdq_core *pkc, 918 struct tpacket_block_desc *pbd, 919 unsigned int len) 920 { 921 struct tpacket3_hdr *ppd; 922 923 ppd = (struct tpacket3_hdr *)curr; 924 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 925 pkc->prev = curr; 926 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 927 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 928 BLOCK_NUM_PKTS(pbd) += 1; 929 atomic_inc(&pkc->blk_fill_in_prog); 930 prb_run_all_ft_ops(pkc, ppd); 931 } 932 933 /* Assumes caller has the sk->rx_queue.lock */ 934 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 935 struct sk_buff *skb, 936 int status, 937 unsigned int len 938 ) 939 { 940 struct tpacket_kbdq_core *pkc; 941 struct tpacket_block_desc *pbd; 942 char *curr, *end; 943 944 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 945 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 946 947 /* Queue is frozen when user space is lagging behind */ 948 if (prb_queue_frozen(pkc)) { 949 /* 950 * Check if that last block which caused the queue to freeze, 951 * is still in_use by user-space. 952 */ 953 if (prb_curr_blk_in_use(pkc, pbd)) { 954 /* Can't record this packet */ 955 return NULL; 956 } else { 957 /* 958 * Ok, the block was released by user-space. 959 * Now let's open that block. 960 * opening a block also thaws the queue. 961 * Thawing is a side effect. 962 */ 963 prb_open_block(pkc, pbd); 964 } 965 } 966 967 smp_mb(); 968 curr = pkc->nxt_offset; 969 pkc->skb = skb; 970 end = (char *)pbd + pkc->kblk_size; 971 972 /* first try the current block */ 973 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 974 prb_fill_curr_block(curr, pkc, pbd, len); 975 return (void *)curr; 976 } 977 978 /* Ok, close the current block */ 979 prb_retire_current_block(pkc, po, 0); 980 981 /* Now, try to dispatch the next block */ 982 curr = (char *)prb_dispatch_next_block(pkc, po); 983 if (curr) { 984 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 985 prb_fill_curr_block(curr, pkc, pbd, len); 986 return (void *)curr; 987 } 988 989 /* 990 * No free blocks are available.user_space hasn't caught up yet. 991 * Queue was just frozen and now this packet will get dropped. 992 */ 993 return NULL; 994 } 995 996 static void *packet_current_rx_frame(struct packet_sock *po, 997 struct sk_buff *skb, 998 int status, unsigned int len) 999 { 1000 char *curr = NULL; 1001 switch (po->tp_version) { 1002 case TPACKET_V1: 1003 case TPACKET_V2: 1004 curr = packet_lookup_frame(po, &po->rx_ring, 1005 po->rx_ring.head, status); 1006 return curr; 1007 case TPACKET_V3: 1008 return __packet_lookup_frame_in_block(po, skb, status, len); 1009 default: 1010 WARN(1, "TPACKET version not supported\n"); 1011 BUG(); 1012 return NULL; 1013 } 1014 } 1015 1016 static void *prb_lookup_block(struct packet_sock *po, 1017 struct packet_ring_buffer *rb, 1018 unsigned int idx, 1019 int status) 1020 { 1021 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1022 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1023 1024 if (status != BLOCK_STATUS(pbd)) 1025 return NULL; 1026 return pbd; 1027 } 1028 1029 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1030 { 1031 unsigned int prev; 1032 if (rb->prb_bdqc.kactive_blk_num) 1033 prev = rb->prb_bdqc.kactive_blk_num-1; 1034 else 1035 prev = rb->prb_bdqc.knum_blocks-1; 1036 return prev; 1037 } 1038 1039 /* Assumes caller has held the rx_queue.lock */ 1040 static void *__prb_previous_block(struct packet_sock *po, 1041 struct packet_ring_buffer *rb, 1042 int status) 1043 { 1044 unsigned int previous = prb_previous_blk_num(rb); 1045 return prb_lookup_block(po, rb, previous, status); 1046 } 1047 1048 static void *packet_previous_rx_frame(struct packet_sock *po, 1049 struct packet_ring_buffer *rb, 1050 int status) 1051 { 1052 if (po->tp_version <= TPACKET_V2) 1053 return packet_previous_frame(po, rb, status); 1054 1055 return __prb_previous_block(po, rb, status); 1056 } 1057 1058 static void packet_increment_rx_head(struct packet_sock *po, 1059 struct packet_ring_buffer *rb) 1060 { 1061 switch (po->tp_version) { 1062 case TPACKET_V1: 1063 case TPACKET_V2: 1064 return packet_increment_head(rb); 1065 case TPACKET_V3: 1066 default: 1067 WARN(1, "TPACKET version not supported.\n"); 1068 BUG(); 1069 return; 1070 } 1071 } 1072 1073 static void *packet_previous_frame(struct packet_sock *po, 1074 struct packet_ring_buffer *rb, 1075 int status) 1076 { 1077 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1078 return packet_lookup_frame(po, rb, previous, status); 1079 } 1080 1081 static void packet_increment_head(struct packet_ring_buffer *buff) 1082 { 1083 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1084 } 1085 1086 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1087 { 1088 struct sock *sk = &po->sk; 1089 bool has_room; 1090 1091 if (po->prot_hook.func != tpacket_rcv) 1092 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize) 1093 <= sk->sk_rcvbuf; 1094 1095 spin_lock(&sk->sk_receive_queue.lock); 1096 if (po->tp_version == TPACKET_V3) 1097 has_room = prb_lookup_block(po, &po->rx_ring, 1098 po->rx_ring.prb_bdqc.kactive_blk_num, 1099 TP_STATUS_KERNEL); 1100 else 1101 has_room = packet_lookup_frame(po, &po->rx_ring, 1102 po->rx_ring.head, 1103 TP_STATUS_KERNEL); 1104 spin_unlock(&sk->sk_receive_queue.lock); 1105 1106 return has_room; 1107 } 1108 1109 static void packet_sock_destruct(struct sock *sk) 1110 { 1111 skb_queue_purge(&sk->sk_error_queue); 1112 1113 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1114 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1115 1116 if (!sock_flag(sk, SOCK_DEAD)) { 1117 pr_err("Attempt to release alive packet socket: %p\n", sk); 1118 return; 1119 } 1120 1121 sk_refcnt_debug_dec(sk); 1122 } 1123 1124 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1125 { 1126 int x = atomic_read(&f->rr_cur) + 1; 1127 1128 if (x >= num) 1129 x = 0; 1130 1131 return x; 1132 } 1133 1134 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1135 struct sk_buff *skb, 1136 unsigned int num) 1137 { 1138 return (((u64)skb->rxhash) * num) >> 32; 1139 } 1140 1141 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1142 struct sk_buff *skb, 1143 unsigned int num) 1144 { 1145 int cur, old; 1146 1147 cur = atomic_read(&f->rr_cur); 1148 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1149 fanout_rr_next(f, num))) != cur) 1150 cur = old; 1151 return cur; 1152 } 1153 1154 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1155 struct sk_buff *skb, 1156 unsigned int num) 1157 { 1158 return smp_processor_id() % num; 1159 } 1160 1161 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1162 struct sk_buff *skb, 1163 unsigned int idx, unsigned int skip, 1164 unsigned int num) 1165 { 1166 unsigned int i, j; 1167 1168 i = j = min_t(int, f->next[idx], num - 1); 1169 do { 1170 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) { 1171 if (i != j) 1172 f->next[idx] = i; 1173 return i; 1174 } 1175 if (++i == num) 1176 i = 0; 1177 } while (i != j); 1178 1179 return idx; 1180 } 1181 1182 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1183 { 1184 return f->flags & (flag >> 8); 1185 } 1186 1187 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1188 struct packet_type *pt, struct net_device *orig_dev) 1189 { 1190 struct packet_fanout *f = pt->af_packet_priv; 1191 unsigned int num = f->num_members; 1192 struct packet_sock *po; 1193 unsigned int idx; 1194 1195 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1196 !num) { 1197 kfree_skb(skb); 1198 return 0; 1199 } 1200 1201 switch (f->type) { 1202 case PACKET_FANOUT_HASH: 1203 default: 1204 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1205 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1206 if (!skb) 1207 return 0; 1208 } 1209 skb_get_rxhash(skb); 1210 idx = fanout_demux_hash(f, skb, num); 1211 break; 1212 case PACKET_FANOUT_LB: 1213 idx = fanout_demux_lb(f, skb, num); 1214 break; 1215 case PACKET_FANOUT_CPU: 1216 idx = fanout_demux_cpu(f, skb, num); 1217 break; 1218 case PACKET_FANOUT_ROLLOVER: 1219 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num); 1220 break; 1221 } 1222 1223 po = pkt_sk(f->arr[idx]); 1224 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) && 1225 unlikely(!packet_rcv_has_room(po, skb))) { 1226 idx = fanout_demux_rollover(f, skb, idx, idx, num); 1227 po = pkt_sk(f->arr[idx]); 1228 } 1229 1230 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1231 } 1232 1233 DEFINE_MUTEX(fanout_mutex); 1234 EXPORT_SYMBOL_GPL(fanout_mutex); 1235 static LIST_HEAD(fanout_list); 1236 1237 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1238 { 1239 struct packet_fanout *f = po->fanout; 1240 1241 spin_lock(&f->lock); 1242 f->arr[f->num_members] = sk; 1243 smp_wmb(); 1244 f->num_members++; 1245 spin_unlock(&f->lock); 1246 } 1247 1248 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1249 { 1250 struct packet_fanout *f = po->fanout; 1251 int i; 1252 1253 spin_lock(&f->lock); 1254 for (i = 0; i < f->num_members; i++) { 1255 if (f->arr[i] == sk) 1256 break; 1257 } 1258 BUG_ON(i >= f->num_members); 1259 f->arr[i] = f->arr[f->num_members - 1]; 1260 f->num_members--; 1261 spin_unlock(&f->lock); 1262 } 1263 1264 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk) 1265 { 1266 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) 1267 return true; 1268 1269 return false; 1270 } 1271 1272 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1273 { 1274 struct packet_sock *po = pkt_sk(sk); 1275 struct packet_fanout *f, *match; 1276 u8 type = type_flags & 0xff; 1277 u8 flags = type_flags >> 8; 1278 int err; 1279 1280 switch (type) { 1281 case PACKET_FANOUT_ROLLOVER: 1282 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1283 return -EINVAL; 1284 case PACKET_FANOUT_HASH: 1285 case PACKET_FANOUT_LB: 1286 case PACKET_FANOUT_CPU: 1287 break; 1288 default: 1289 return -EINVAL; 1290 } 1291 1292 if (!po->running) 1293 return -EINVAL; 1294 1295 if (po->fanout) 1296 return -EALREADY; 1297 1298 mutex_lock(&fanout_mutex); 1299 match = NULL; 1300 list_for_each_entry(f, &fanout_list, list) { 1301 if (f->id == id && 1302 read_pnet(&f->net) == sock_net(sk)) { 1303 match = f; 1304 break; 1305 } 1306 } 1307 err = -EINVAL; 1308 if (match && match->flags != flags) 1309 goto out; 1310 if (!match) { 1311 err = -ENOMEM; 1312 match = kzalloc(sizeof(*match), GFP_KERNEL); 1313 if (!match) 1314 goto out; 1315 write_pnet(&match->net, sock_net(sk)); 1316 match->id = id; 1317 match->type = type; 1318 match->flags = flags; 1319 atomic_set(&match->rr_cur, 0); 1320 INIT_LIST_HEAD(&match->list); 1321 spin_lock_init(&match->lock); 1322 atomic_set(&match->sk_ref, 0); 1323 match->prot_hook.type = po->prot_hook.type; 1324 match->prot_hook.dev = po->prot_hook.dev; 1325 match->prot_hook.func = packet_rcv_fanout; 1326 match->prot_hook.af_packet_priv = match; 1327 match->prot_hook.id_match = match_fanout_group; 1328 dev_add_pack(&match->prot_hook); 1329 list_add(&match->list, &fanout_list); 1330 } 1331 err = -EINVAL; 1332 if (match->type == type && 1333 match->prot_hook.type == po->prot_hook.type && 1334 match->prot_hook.dev == po->prot_hook.dev) { 1335 err = -ENOSPC; 1336 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1337 __dev_remove_pack(&po->prot_hook); 1338 po->fanout = match; 1339 atomic_inc(&match->sk_ref); 1340 __fanout_link(sk, po); 1341 err = 0; 1342 } 1343 } 1344 out: 1345 mutex_unlock(&fanout_mutex); 1346 return err; 1347 } 1348 1349 static void fanout_release(struct sock *sk) 1350 { 1351 struct packet_sock *po = pkt_sk(sk); 1352 struct packet_fanout *f; 1353 1354 f = po->fanout; 1355 if (!f) 1356 return; 1357 1358 mutex_lock(&fanout_mutex); 1359 po->fanout = NULL; 1360 1361 if (atomic_dec_and_test(&f->sk_ref)) { 1362 list_del(&f->list); 1363 dev_remove_pack(&f->prot_hook); 1364 kfree(f); 1365 } 1366 mutex_unlock(&fanout_mutex); 1367 } 1368 1369 static const struct proto_ops packet_ops; 1370 1371 static const struct proto_ops packet_ops_spkt; 1372 1373 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1374 struct packet_type *pt, struct net_device *orig_dev) 1375 { 1376 struct sock *sk; 1377 struct sockaddr_pkt *spkt; 1378 1379 /* 1380 * When we registered the protocol we saved the socket in the data 1381 * field for just this event. 1382 */ 1383 1384 sk = pt->af_packet_priv; 1385 1386 /* 1387 * Yank back the headers [hope the device set this 1388 * right or kerboom...] 1389 * 1390 * Incoming packets have ll header pulled, 1391 * push it back. 1392 * 1393 * For outgoing ones skb->data == skb_mac_header(skb) 1394 * so that this procedure is noop. 1395 */ 1396 1397 if (skb->pkt_type == PACKET_LOOPBACK) 1398 goto out; 1399 1400 if (!net_eq(dev_net(dev), sock_net(sk))) 1401 goto out; 1402 1403 skb = skb_share_check(skb, GFP_ATOMIC); 1404 if (skb == NULL) 1405 goto oom; 1406 1407 /* drop any routing info */ 1408 skb_dst_drop(skb); 1409 1410 /* drop conntrack reference */ 1411 nf_reset(skb); 1412 1413 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1414 1415 skb_push(skb, skb->data - skb_mac_header(skb)); 1416 1417 /* 1418 * The SOCK_PACKET socket receives _all_ frames. 1419 */ 1420 1421 spkt->spkt_family = dev->type; 1422 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1423 spkt->spkt_protocol = skb->protocol; 1424 1425 /* 1426 * Charge the memory to the socket. This is done specifically 1427 * to prevent sockets using all the memory up. 1428 */ 1429 1430 if (sock_queue_rcv_skb(sk, skb) == 0) 1431 return 0; 1432 1433 out: 1434 kfree_skb(skb); 1435 oom: 1436 return 0; 1437 } 1438 1439 1440 /* 1441 * Output a raw packet to a device layer. This bypasses all the other 1442 * protocol layers and you must therefore supply it with a complete frame 1443 */ 1444 1445 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1446 struct msghdr *msg, size_t len) 1447 { 1448 struct sock *sk = sock->sk; 1449 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1450 struct sk_buff *skb = NULL; 1451 struct net_device *dev; 1452 __be16 proto = 0; 1453 int err; 1454 int extra_len = 0; 1455 1456 /* 1457 * Get and verify the address. 1458 */ 1459 1460 if (saddr) { 1461 if (msg->msg_namelen < sizeof(struct sockaddr)) 1462 return -EINVAL; 1463 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1464 proto = saddr->spkt_protocol; 1465 } else 1466 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1467 1468 /* 1469 * Find the device first to size check it 1470 */ 1471 1472 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1473 retry: 1474 rcu_read_lock(); 1475 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1476 err = -ENODEV; 1477 if (dev == NULL) 1478 goto out_unlock; 1479 1480 err = -ENETDOWN; 1481 if (!(dev->flags & IFF_UP)) 1482 goto out_unlock; 1483 1484 /* 1485 * You may not queue a frame bigger than the mtu. This is the lowest level 1486 * raw protocol and you must do your own fragmentation at this level. 1487 */ 1488 1489 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1490 if (!netif_supports_nofcs(dev)) { 1491 err = -EPROTONOSUPPORT; 1492 goto out_unlock; 1493 } 1494 extra_len = 4; /* We're doing our own CRC */ 1495 } 1496 1497 err = -EMSGSIZE; 1498 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1499 goto out_unlock; 1500 1501 if (!skb) { 1502 size_t reserved = LL_RESERVED_SPACE(dev); 1503 int tlen = dev->needed_tailroom; 1504 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1505 1506 rcu_read_unlock(); 1507 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1508 if (skb == NULL) 1509 return -ENOBUFS; 1510 /* FIXME: Save some space for broken drivers that write a hard 1511 * header at transmission time by themselves. PPP is the notable 1512 * one here. This should really be fixed at the driver level. 1513 */ 1514 skb_reserve(skb, reserved); 1515 skb_reset_network_header(skb); 1516 1517 /* Try to align data part correctly */ 1518 if (hhlen) { 1519 skb->data -= hhlen; 1520 skb->tail -= hhlen; 1521 if (len < hhlen) 1522 skb_reset_network_header(skb); 1523 } 1524 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1525 if (err) 1526 goto out_free; 1527 goto retry; 1528 } 1529 1530 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1531 /* Earlier code assumed this would be a VLAN pkt, 1532 * double-check this now that we have the actual 1533 * packet in hand. 1534 */ 1535 struct ethhdr *ehdr; 1536 skb_reset_mac_header(skb); 1537 ehdr = eth_hdr(skb); 1538 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1539 err = -EMSGSIZE; 1540 goto out_unlock; 1541 } 1542 } 1543 1544 skb->protocol = proto; 1545 skb->dev = dev; 1546 skb->priority = sk->sk_priority; 1547 skb->mark = sk->sk_mark; 1548 1549 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1550 1551 if (unlikely(extra_len == 4)) 1552 skb->no_fcs = 1; 1553 1554 skb_probe_transport_header(skb, 0); 1555 1556 dev_queue_xmit(skb); 1557 rcu_read_unlock(); 1558 return len; 1559 1560 out_unlock: 1561 rcu_read_unlock(); 1562 out_free: 1563 kfree_skb(skb); 1564 return err; 1565 } 1566 1567 static unsigned int run_filter(const struct sk_buff *skb, 1568 const struct sock *sk, 1569 unsigned int res) 1570 { 1571 struct sk_filter *filter; 1572 1573 rcu_read_lock(); 1574 filter = rcu_dereference(sk->sk_filter); 1575 if (filter != NULL) 1576 res = SK_RUN_FILTER(filter, skb); 1577 rcu_read_unlock(); 1578 1579 return res; 1580 } 1581 1582 /* 1583 * This function makes lazy skb cloning in hope that most of packets 1584 * are discarded by BPF. 1585 * 1586 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1587 * and skb->cb are mangled. It works because (and until) packets 1588 * falling here are owned by current CPU. Output packets are cloned 1589 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1590 * sequencially, so that if we return skb to original state on exit, 1591 * we will not harm anyone. 1592 */ 1593 1594 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1595 struct packet_type *pt, struct net_device *orig_dev) 1596 { 1597 struct sock *sk; 1598 struct sockaddr_ll *sll; 1599 struct packet_sock *po; 1600 u8 *skb_head = skb->data; 1601 int skb_len = skb->len; 1602 unsigned int snaplen, res; 1603 1604 if (skb->pkt_type == PACKET_LOOPBACK) 1605 goto drop; 1606 1607 sk = pt->af_packet_priv; 1608 po = pkt_sk(sk); 1609 1610 if (!net_eq(dev_net(dev), sock_net(sk))) 1611 goto drop; 1612 1613 skb->dev = dev; 1614 1615 if (dev->header_ops) { 1616 /* The device has an explicit notion of ll header, 1617 * exported to higher levels. 1618 * 1619 * Otherwise, the device hides details of its frame 1620 * structure, so that corresponding packet head is 1621 * never delivered to user. 1622 */ 1623 if (sk->sk_type != SOCK_DGRAM) 1624 skb_push(skb, skb->data - skb_mac_header(skb)); 1625 else if (skb->pkt_type == PACKET_OUTGOING) { 1626 /* Special case: outgoing packets have ll header at head */ 1627 skb_pull(skb, skb_network_offset(skb)); 1628 } 1629 } 1630 1631 snaplen = skb->len; 1632 1633 res = run_filter(skb, sk, snaplen); 1634 if (!res) 1635 goto drop_n_restore; 1636 if (snaplen > res) 1637 snaplen = res; 1638 1639 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1640 goto drop_n_acct; 1641 1642 if (skb_shared(skb)) { 1643 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1644 if (nskb == NULL) 1645 goto drop_n_acct; 1646 1647 if (skb_head != skb->data) { 1648 skb->data = skb_head; 1649 skb->len = skb_len; 1650 } 1651 consume_skb(skb); 1652 skb = nskb; 1653 } 1654 1655 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1656 sizeof(skb->cb)); 1657 1658 sll = &PACKET_SKB_CB(skb)->sa.ll; 1659 sll->sll_family = AF_PACKET; 1660 sll->sll_hatype = dev->type; 1661 sll->sll_protocol = skb->protocol; 1662 sll->sll_pkttype = skb->pkt_type; 1663 if (unlikely(po->origdev)) 1664 sll->sll_ifindex = orig_dev->ifindex; 1665 else 1666 sll->sll_ifindex = dev->ifindex; 1667 1668 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1669 1670 PACKET_SKB_CB(skb)->origlen = skb->len; 1671 1672 if (pskb_trim(skb, snaplen)) 1673 goto drop_n_acct; 1674 1675 skb_set_owner_r(skb, sk); 1676 skb->dev = NULL; 1677 skb_dst_drop(skb); 1678 1679 /* drop conntrack reference */ 1680 nf_reset(skb); 1681 1682 spin_lock(&sk->sk_receive_queue.lock); 1683 po->stats.stats1.tp_packets++; 1684 skb->dropcount = atomic_read(&sk->sk_drops); 1685 __skb_queue_tail(&sk->sk_receive_queue, skb); 1686 spin_unlock(&sk->sk_receive_queue.lock); 1687 sk->sk_data_ready(sk, skb->len); 1688 return 0; 1689 1690 drop_n_acct: 1691 spin_lock(&sk->sk_receive_queue.lock); 1692 po->stats.stats1.tp_drops++; 1693 atomic_inc(&sk->sk_drops); 1694 spin_unlock(&sk->sk_receive_queue.lock); 1695 1696 drop_n_restore: 1697 if (skb_head != skb->data && skb_shared(skb)) { 1698 skb->data = skb_head; 1699 skb->len = skb_len; 1700 } 1701 drop: 1702 consume_skb(skb); 1703 return 0; 1704 } 1705 1706 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1707 struct packet_type *pt, struct net_device *orig_dev) 1708 { 1709 struct sock *sk; 1710 struct packet_sock *po; 1711 struct sockaddr_ll *sll; 1712 union tpacket_uhdr h; 1713 u8 *skb_head = skb->data; 1714 int skb_len = skb->len; 1715 unsigned int snaplen, res; 1716 unsigned long status = TP_STATUS_USER; 1717 unsigned short macoff, netoff, hdrlen; 1718 struct sk_buff *copy_skb = NULL; 1719 struct timespec ts; 1720 __u32 ts_status; 1721 1722 if (skb->pkt_type == PACKET_LOOPBACK) 1723 goto drop; 1724 1725 sk = pt->af_packet_priv; 1726 po = pkt_sk(sk); 1727 1728 if (!net_eq(dev_net(dev), sock_net(sk))) 1729 goto drop; 1730 1731 if (dev->header_ops) { 1732 if (sk->sk_type != SOCK_DGRAM) 1733 skb_push(skb, skb->data - skb_mac_header(skb)); 1734 else if (skb->pkt_type == PACKET_OUTGOING) { 1735 /* Special case: outgoing packets have ll header at head */ 1736 skb_pull(skb, skb_network_offset(skb)); 1737 } 1738 } 1739 1740 if (skb->ip_summed == CHECKSUM_PARTIAL) 1741 status |= TP_STATUS_CSUMNOTREADY; 1742 1743 snaplen = skb->len; 1744 1745 res = run_filter(skb, sk, snaplen); 1746 if (!res) 1747 goto drop_n_restore; 1748 if (snaplen > res) 1749 snaplen = res; 1750 1751 if (sk->sk_type == SOCK_DGRAM) { 1752 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1753 po->tp_reserve; 1754 } else { 1755 unsigned int maclen = skb_network_offset(skb); 1756 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1757 (maclen < 16 ? 16 : maclen)) + 1758 po->tp_reserve; 1759 macoff = netoff - maclen; 1760 } 1761 if (po->tp_version <= TPACKET_V2) { 1762 if (macoff + snaplen > po->rx_ring.frame_size) { 1763 if (po->copy_thresh && 1764 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1765 if (skb_shared(skb)) { 1766 copy_skb = skb_clone(skb, GFP_ATOMIC); 1767 } else { 1768 copy_skb = skb_get(skb); 1769 skb_head = skb->data; 1770 } 1771 if (copy_skb) 1772 skb_set_owner_r(copy_skb, sk); 1773 } 1774 snaplen = po->rx_ring.frame_size - macoff; 1775 if ((int)snaplen < 0) 1776 snaplen = 0; 1777 } 1778 } 1779 spin_lock(&sk->sk_receive_queue.lock); 1780 h.raw = packet_current_rx_frame(po, skb, 1781 TP_STATUS_KERNEL, (macoff+snaplen)); 1782 if (!h.raw) 1783 goto ring_is_full; 1784 if (po->tp_version <= TPACKET_V2) { 1785 packet_increment_rx_head(po, &po->rx_ring); 1786 /* 1787 * LOSING will be reported till you read the stats, 1788 * because it's COR - Clear On Read. 1789 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1790 * at packet level. 1791 */ 1792 if (po->stats.stats1.tp_drops) 1793 status |= TP_STATUS_LOSING; 1794 } 1795 po->stats.stats1.tp_packets++; 1796 if (copy_skb) { 1797 status |= TP_STATUS_COPY; 1798 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1799 } 1800 spin_unlock(&sk->sk_receive_queue.lock); 1801 1802 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1803 1804 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 1805 getnstimeofday(&ts); 1806 1807 status |= ts_status; 1808 1809 switch (po->tp_version) { 1810 case TPACKET_V1: 1811 h.h1->tp_len = skb->len; 1812 h.h1->tp_snaplen = snaplen; 1813 h.h1->tp_mac = macoff; 1814 h.h1->tp_net = netoff; 1815 h.h1->tp_sec = ts.tv_sec; 1816 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 1817 hdrlen = sizeof(*h.h1); 1818 break; 1819 case TPACKET_V2: 1820 h.h2->tp_len = skb->len; 1821 h.h2->tp_snaplen = snaplen; 1822 h.h2->tp_mac = macoff; 1823 h.h2->tp_net = netoff; 1824 h.h2->tp_sec = ts.tv_sec; 1825 h.h2->tp_nsec = ts.tv_nsec; 1826 if (vlan_tx_tag_present(skb)) { 1827 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1828 status |= TP_STATUS_VLAN_VALID; 1829 } else { 1830 h.h2->tp_vlan_tci = 0; 1831 } 1832 h.h2->tp_padding = 0; 1833 hdrlen = sizeof(*h.h2); 1834 break; 1835 case TPACKET_V3: 1836 /* tp_nxt_offset,vlan are already populated above. 1837 * So DONT clear those fields here 1838 */ 1839 h.h3->tp_status |= status; 1840 h.h3->tp_len = skb->len; 1841 h.h3->tp_snaplen = snaplen; 1842 h.h3->tp_mac = macoff; 1843 h.h3->tp_net = netoff; 1844 h.h3->tp_sec = ts.tv_sec; 1845 h.h3->tp_nsec = ts.tv_nsec; 1846 hdrlen = sizeof(*h.h3); 1847 break; 1848 default: 1849 BUG(); 1850 } 1851 1852 sll = h.raw + TPACKET_ALIGN(hdrlen); 1853 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1854 sll->sll_family = AF_PACKET; 1855 sll->sll_hatype = dev->type; 1856 sll->sll_protocol = skb->protocol; 1857 sll->sll_pkttype = skb->pkt_type; 1858 if (unlikely(po->origdev)) 1859 sll->sll_ifindex = orig_dev->ifindex; 1860 else 1861 sll->sll_ifindex = dev->ifindex; 1862 1863 smp_mb(); 1864 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1865 { 1866 u8 *start, *end; 1867 1868 if (po->tp_version <= TPACKET_V2) { 1869 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1870 + macoff + snaplen); 1871 for (start = h.raw; start < end; start += PAGE_SIZE) 1872 flush_dcache_page(pgv_to_page(start)); 1873 } 1874 smp_wmb(); 1875 } 1876 #endif 1877 if (po->tp_version <= TPACKET_V2) 1878 __packet_set_status(po, h.raw, status); 1879 else 1880 prb_clear_blk_fill_status(&po->rx_ring); 1881 1882 sk->sk_data_ready(sk, 0); 1883 1884 drop_n_restore: 1885 if (skb_head != skb->data && skb_shared(skb)) { 1886 skb->data = skb_head; 1887 skb->len = skb_len; 1888 } 1889 drop: 1890 kfree_skb(skb); 1891 return 0; 1892 1893 ring_is_full: 1894 po->stats.stats1.tp_drops++; 1895 spin_unlock(&sk->sk_receive_queue.lock); 1896 1897 sk->sk_data_ready(sk, 0); 1898 kfree_skb(copy_skb); 1899 goto drop_n_restore; 1900 } 1901 1902 static void tpacket_destruct_skb(struct sk_buff *skb) 1903 { 1904 struct packet_sock *po = pkt_sk(skb->sk); 1905 void *ph; 1906 1907 if (likely(po->tx_ring.pg_vec)) { 1908 __u32 ts; 1909 1910 ph = skb_shinfo(skb)->destructor_arg; 1911 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1912 atomic_dec(&po->tx_ring.pending); 1913 1914 ts = __packet_set_timestamp(po, ph, skb); 1915 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 1916 } 1917 1918 sock_wfree(skb); 1919 } 1920 1921 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1922 void *frame, struct net_device *dev, int size_max, 1923 __be16 proto, unsigned char *addr, int hlen) 1924 { 1925 union tpacket_uhdr ph; 1926 int to_write, offset, len, tp_len, nr_frags, len_max; 1927 struct socket *sock = po->sk.sk_socket; 1928 struct page *page; 1929 void *data; 1930 int err; 1931 1932 ph.raw = frame; 1933 1934 skb->protocol = proto; 1935 skb->dev = dev; 1936 skb->priority = po->sk.sk_priority; 1937 skb->mark = po->sk.sk_mark; 1938 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 1939 skb_shinfo(skb)->destructor_arg = ph.raw; 1940 1941 switch (po->tp_version) { 1942 case TPACKET_V2: 1943 tp_len = ph.h2->tp_len; 1944 break; 1945 default: 1946 tp_len = ph.h1->tp_len; 1947 break; 1948 } 1949 if (unlikely(tp_len > size_max)) { 1950 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1951 return -EMSGSIZE; 1952 } 1953 1954 skb_reserve(skb, hlen); 1955 skb_reset_network_header(skb); 1956 skb_probe_transport_header(skb, 0); 1957 1958 if (po->tp_tx_has_off) { 1959 int off_min, off_max, off; 1960 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 1961 off_max = po->tx_ring.frame_size - tp_len; 1962 if (sock->type == SOCK_DGRAM) { 1963 switch (po->tp_version) { 1964 case TPACKET_V2: 1965 off = ph.h2->tp_net; 1966 break; 1967 default: 1968 off = ph.h1->tp_net; 1969 break; 1970 } 1971 } else { 1972 switch (po->tp_version) { 1973 case TPACKET_V2: 1974 off = ph.h2->tp_mac; 1975 break; 1976 default: 1977 off = ph.h1->tp_mac; 1978 break; 1979 } 1980 } 1981 if (unlikely((off < off_min) || (off_max < off))) 1982 return -EINVAL; 1983 data = ph.raw + off; 1984 } else { 1985 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1986 } 1987 to_write = tp_len; 1988 1989 if (sock->type == SOCK_DGRAM) { 1990 err = dev_hard_header(skb, dev, ntohs(proto), addr, 1991 NULL, tp_len); 1992 if (unlikely(err < 0)) 1993 return -EINVAL; 1994 } else if (dev->hard_header_len) { 1995 /* net device doesn't like empty head */ 1996 if (unlikely(tp_len <= dev->hard_header_len)) { 1997 pr_err("packet size is too short (%d < %d)\n", 1998 tp_len, dev->hard_header_len); 1999 return -EINVAL; 2000 } 2001 2002 skb_push(skb, dev->hard_header_len); 2003 err = skb_store_bits(skb, 0, data, 2004 dev->hard_header_len); 2005 if (unlikely(err)) 2006 return err; 2007 2008 data += dev->hard_header_len; 2009 to_write -= dev->hard_header_len; 2010 } 2011 2012 offset = offset_in_page(data); 2013 len_max = PAGE_SIZE - offset; 2014 len = ((to_write > len_max) ? len_max : to_write); 2015 2016 skb->data_len = to_write; 2017 skb->len += to_write; 2018 skb->truesize += to_write; 2019 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2020 2021 while (likely(to_write)) { 2022 nr_frags = skb_shinfo(skb)->nr_frags; 2023 2024 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2025 pr_err("Packet exceed the number of skb frags(%lu)\n", 2026 MAX_SKB_FRAGS); 2027 return -EFAULT; 2028 } 2029 2030 page = pgv_to_page(data); 2031 data += len; 2032 flush_dcache_page(page); 2033 get_page(page); 2034 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2035 to_write -= len; 2036 offset = 0; 2037 len_max = PAGE_SIZE; 2038 len = ((to_write > len_max) ? len_max : to_write); 2039 } 2040 2041 return tp_len; 2042 } 2043 2044 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2045 { 2046 struct sk_buff *skb; 2047 struct net_device *dev; 2048 __be16 proto; 2049 bool need_rls_dev = false; 2050 int err, reserve = 0; 2051 void *ph; 2052 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2053 int tp_len, size_max; 2054 unsigned char *addr; 2055 int len_sum = 0; 2056 int status = TP_STATUS_AVAILABLE; 2057 int hlen, tlen; 2058 2059 mutex_lock(&po->pg_vec_lock); 2060 2061 if (saddr == NULL) { 2062 dev = po->prot_hook.dev; 2063 proto = po->num; 2064 addr = NULL; 2065 } else { 2066 err = -EINVAL; 2067 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2068 goto out; 2069 if (msg->msg_namelen < (saddr->sll_halen 2070 + offsetof(struct sockaddr_ll, 2071 sll_addr))) 2072 goto out; 2073 proto = saddr->sll_protocol; 2074 addr = saddr->sll_addr; 2075 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2076 need_rls_dev = true; 2077 } 2078 2079 err = -ENXIO; 2080 if (unlikely(dev == NULL)) 2081 goto out; 2082 2083 reserve = dev->hard_header_len; 2084 2085 err = -ENETDOWN; 2086 if (unlikely(!(dev->flags & IFF_UP))) 2087 goto out_put; 2088 2089 size_max = po->tx_ring.frame_size 2090 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2091 2092 if (size_max > dev->mtu + reserve) 2093 size_max = dev->mtu + reserve; 2094 2095 do { 2096 ph = packet_current_frame(po, &po->tx_ring, 2097 TP_STATUS_SEND_REQUEST); 2098 2099 if (unlikely(ph == NULL)) { 2100 schedule(); 2101 continue; 2102 } 2103 2104 status = TP_STATUS_SEND_REQUEST; 2105 hlen = LL_RESERVED_SPACE(dev); 2106 tlen = dev->needed_tailroom; 2107 skb = sock_alloc_send_skb(&po->sk, 2108 hlen + tlen + sizeof(struct sockaddr_ll), 2109 0, &err); 2110 2111 if (unlikely(skb == NULL)) 2112 goto out_status; 2113 2114 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2115 addr, hlen); 2116 2117 if (unlikely(tp_len < 0)) { 2118 if (po->tp_loss) { 2119 __packet_set_status(po, ph, 2120 TP_STATUS_AVAILABLE); 2121 packet_increment_head(&po->tx_ring); 2122 kfree_skb(skb); 2123 continue; 2124 } else { 2125 status = TP_STATUS_WRONG_FORMAT; 2126 err = tp_len; 2127 goto out_status; 2128 } 2129 } 2130 2131 skb->destructor = tpacket_destruct_skb; 2132 __packet_set_status(po, ph, TP_STATUS_SENDING); 2133 atomic_inc(&po->tx_ring.pending); 2134 2135 status = TP_STATUS_SEND_REQUEST; 2136 err = dev_queue_xmit(skb); 2137 if (unlikely(err > 0)) { 2138 err = net_xmit_errno(err); 2139 if (err && __packet_get_status(po, ph) == 2140 TP_STATUS_AVAILABLE) { 2141 /* skb was destructed already */ 2142 skb = NULL; 2143 goto out_status; 2144 } 2145 /* 2146 * skb was dropped but not destructed yet; 2147 * let's treat it like congestion or err < 0 2148 */ 2149 err = 0; 2150 } 2151 packet_increment_head(&po->tx_ring); 2152 len_sum += tp_len; 2153 } while (likely((ph != NULL) || 2154 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2155 (atomic_read(&po->tx_ring.pending)))) 2156 ); 2157 2158 err = len_sum; 2159 goto out_put; 2160 2161 out_status: 2162 __packet_set_status(po, ph, status); 2163 kfree_skb(skb); 2164 out_put: 2165 if (need_rls_dev) 2166 dev_put(dev); 2167 out: 2168 mutex_unlock(&po->pg_vec_lock); 2169 return err; 2170 } 2171 2172 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2173 size_t reserve, size_t len, 2174 size_t linear, int noblock, 2175 int *err) 2176 { 2177 struct sk_buff *skb; 2178 2179 /* Under a page? Don't bother with paged skb. */ 2180 if (prepad + len < PAGE_SIZE || !linear) 2181 linear = len; 2182 2183 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2184 err); 2185 if (!skb) 2186 return NULL; 2187 2188 skb_reserve(skb, reserve); 2189 skb_put(skb, linear); 2190 skb->data_len = len - linear; 2191 skb->len += len - linear; 2192 2193 return skb; 2194 } 2195 2196 static int packet_snd(struct socket *sock, 2197 struct msghdr *msg, size_t len) 2198 { 2199 struct sock *sk = sock->sk; 2200 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2201 struct sk_buff *skb; 2202 struct net_device *dev; 2203 __be16 proto; 2204 bool need_rls_dev = false; 2205 unsigned char *addr; 2206 int err, reserve = 0; 2207 struct virtio_net_hdr vnet_hdr = { 0 }; 2208 int offset = 0; 2209 int vnet_hdr_len; 2210 struct packet_sock *po = pkt_sk(sk); 2211 unsigned short gso_type = 0; 2212 int hlen, tlen; 2213 int extra_len = 0; 2214 2215 /* 2216 * Get and verify the address. 2217 */ 2218 2219 if (saddr == NULL) { 2220 dev = po->prot_hook.dev; 2221 proto = po->num; 2222 addr = NULL; 2223 } else { 2224 err = -EINVAL; 2225 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2226 goto out; 2227 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2228 goto out; 2229 proto = saddr->sll_protocol; 2230 addr = saddr->sll_addr; 2231 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2232 need_rls_dev = true; 2233 } 2234 2235 err = -ENXIO; 2236 if (dev == NULL) 2237 goto out_unlock; 2238 if (sock->type == SOCK_RAW) 2239 reserve = dev->hard_header_len; 2240 2241 err = -ENETDOWN; 2242 if (!(dev->flags & IFF_UP)) 2243 goto out_unlock; 2244 2245 if (po->has_vnet_hdr) { 2246 vnet_hdr_len = sizeof(vnet_hdr); 2247 2248 err = -EINVAL; 2249 if (len < vnet_hdr_len) 2250 goto out_unlock; 2251 2252 len -= vnet_hdr_len; 2253 2254 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2255 vnet_hdr_len); 2256 if (err < 0) 2257 goto out_unlock; 2258 2259 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2260 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2261 vnet_hdr.hdr_len)) 2262 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2263 vnet_hdr.csum_offset + 2; 2264 2265 err = -EINVAL; 2266 if (vnet_hdr.hdr_len > len) 2267 goto out_unlock; 2268 2269 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2270 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2271 case VIRTIO_NET_HDR_GSO_TCPV4: 2272 gso_type = SKB_GSO_TCPV4; 2273 break; 2274 case VIRTIO_NET_HDR_GSO_TCPV6: 2275 gso_type = SKB_GSO_TCPV6; 2276 break; 2277 case VIRTIO_NET_HDR_GSO_UDP: 2278 gso_type = SKB_GSO_UDP; 2279 break; 2280 default: 2281 goto out_unlock; 2282 } 2283 2284 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2285 gso_type |= SKB_GSO_TCP_ECN; 2286 2287 if (vnet_hdr.gso_size == 0) 2288 goto out_unlock; 2289 2290 } 2291 } 2292 2293 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2294 if (!netif_supports_nofcs(dev)) { 2295 err = -EPROTONOSUPPORT; 2296 goto out_unlock; 2297 } 2298 extra_len = 4; /* We're doing our own CRC */ 2299 } 2300 2301 err = -EMSGSIZE; 2302 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2303 goto out_unlock; 2304 2305 err = -ENOBUFS; 2306 hlen = LL_RESERVED_SPACE(dev); 2307 tlen = dev->needed_tailroom; 2308 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2309 msg->msg_flags & MSG_DONTWAIT, &err); 2310 if (skb == NULL) 2311 goto out_unlock; 2312 2313 skb_set_network_header(skb, reserve); 2314 2315 err = -EINVAL; 2316 if (sock->type == SOCK_DGRAM && 2317 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2318 goto out_free; 2319 2320 /* Returns -EFAULT on error */ 2321 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2322 if (err) 2323 goto out_free; 2324 2325 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2326 2327 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2328 /* Earlier code assumed this would be a VLAN pkt, 2329 * double-check this now that we have the actual 2330 * packet in hand. 2331 */ 2332 struct ethhdr *ehdr; 2333 skb_reset_mac_header(skb); 2334 ehdr = eth_hdr(skb); 2335 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2336 err = -EMSGSIZE; 2337 goto out_free; 2338 } 2339 } 2340 2341 skb->protocol = proto; 2342 skb->dev = dev; 2343 skb->priority = sk->sk_priority; 2344 skb->mark = sk->sk_mark; 2345 2346 if (po->has_vnet_hdr) { 2347 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2348 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2349 vnet_hdr.csum_offset)) { 2350 err = -EINVAL; 2351 goto out_free; 2352 } 2353 } 2354 2355 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2356 skb_shinfo(skb)->gso_type = gso_type; 2357 2358 /* Header must be checked, and gso_segs computed. */ 2359 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2360 skb_shinfo(skb)->gso_segs = 0; 2361 2362 len += vnet_hdr_len; 2363 } 2364 2365 skb_probe_transport_header(skb, reserve); 2366 2367 if (unlikely(extra_len == 4)) 2368 skb->no_fcs = 1; 2369 2370 /* 2371 * Now send it 2372 */ 2373 2374 err = dev_queue_xmit(skb); 2375 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2376 goto out_unlock; 2377 2378 if (need_rls_dev) 2379 dev_put(dev); 2380 2381 return len; 2382 2383 out_free: 2384 kfree_skb(skb); 2385 out_unlock: 2386 if (dev && need_rls_dev) 2387 dev_put(dev); 2388 out: 2389 return err; 2390 } 2391 2392 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2393 struct msghdr *msg, size_t len) 2394 { 2395 struct sock *sk = sock->sk; 2396 struct packet_sock *po = pkt_sk(sk); 2397 if (po->tx_ring.pg_vec) 2398 return tpacket_snd(po, msg); 2399 else 2400 return packet_snd(sock, msg, len); 2401 } 2402 2403 /* 2404 * Close a PACKET socket. This is fairly simple. We immediately go 2405 * to 'closed' state and remove our protocol entry in the device list. 2406 */ 2407 2408 static int packet_release(struct socket *sock) 2409 { 2410 struct sock *sk = sock->sk; 2411 struct packet_sock *po; 2412 struct net *net; 2413 union tpacket_req_u req_u; 2414 2415 if (!sk) 2416 return 0; 2417 2418 net = sock_net(sk); 2419 po = pkt_sk(sk); 2420 2421 mutex_lock(&net->packet.sklist_lock); 2422 sk_del_node_init_rcu(sk); 2423 mutex_unlock(&net->packet.sklist_lock); 2424 2425 preempt_disable(); 2426 sock_prot_inuse_add(net, sk->sk_prot, -1); 2427 preempt_enable(); 2428 2429 spin_lock(&po->bind_lock); 2430 unregister_prot_hook(sk, false); 2431 if (po->prot_hook.dev) { 2432 dev_put(po->prot_hook.dev); 2433 po->prot_hook.dev = NULL; 2434 } 2435 spin_unlock(&po->bind_lock); 2436 2437 packet_flush_mclist(sk); 2438 2439 if (po->rx_ring.pg_vec) { 2440 memset(&req_u, 0, sizeof(req_u)); 2441 packet_set_ring(sk, &req_u, 1, 0); 2442 } 2443 2444 if (po->tx_ring.pg_vec) { 2445 memset(&req_u, 0, sizeof(req_u)); 2446 packet_set_ring(sk, &req_u, 1, 1); 2447 } 2448 2449 fanout_release(sk); 2450 2451 synchronize_net(); 2452 /* 2453 * Now the socket is dead. No more input will appear. 2454 */ 2455 sock_orphan(sk); 2456 sock->sk = NULL; 2457 2458 /* Purge queues */ 2459 2460 skb_queue_purge(&sk->sk_receive_queue); 2461 sk_refcnt_debug_release(sk); 2462 2463 sock_put(sk); 2464 return 0; 2465 } 2466 2467 /* 2468 * Attach a packet hook. 2469 */ 2470 2471 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2472 { 2473 struct packet_sock *po = pkt_sk(sk); 2474 2475 if (po->fanout) { 2476 if (dev) 2477 dev_put(dev); 2478 2479 return -EINVAL; 2480 } 2481 2482 lock_sock(sk); 2483 2484 spin_lock(&po->bind_lock); 2485 unregister_prot_hook(sk, true); 2486 po->num = protocol; 2487 po->prot_hook.type = protocol; 2488 if (po->prot_hook.dev) 2489 dev_put(po->prot_hook.dev); 2490 po->prot_hook.dev = dev; 2491 2492 po->ifindex = dev ? dev->ifindex : 0; 2493 2494 if (protocol == 0) 2495 goto out_unlock; 2496 2497 if (!dev || (dev->flags & IFF_UP)) { 2498 register_prot_hook(sk); 2499 } else { 2500 sk->sk_err = ENETDOWN; 2501 if (!sock_flag(sk, SOCK_DEAD)) 2502 sk->sk_error_report(sk); 2503 } 2504 2505 out_unlock: 2506 spin_unlock(&po->bind_lock); 2507 release_sock(sk); 2508 return 0; 2509 } 2510 2511 /* 2512 * Bind a packet socket to a device 2513 */ 2514 2515 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2516 int addr_len) 2517 { 2518 struct sock *sk = sock->sk; 2519 char name[15]; 2520 struct net_device *dev; 2521 int err = -ENODEV; 2522 2523 /* 2524 * Check legality 2525 */ 2526 2527 if (addr_len != sizeof(struct sockaddr)) 2528 return -EINVAL; 2529 strlcpy(name, uaddr->sa_data, sizeof(name)); 2530 2531 dev = dev_get_by_name(sock_net(sk), name); 2532 if (dev) 2533 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2534 return err; 2535 } 2536 2537 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2538 { 2539 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2540 struct sock *sk = sock->sk; 2541 struct net_device *dev = NULL; 2542 int err; 2543 2544 2545 /* 2546 * Check legality 2547 */ 2548 2549 if (addr_len < sizeof(struct sockaddr_ll)) 2550 return -EINVAL; 2551 if (sll->sll_family != AF_PACKET) 2552 return -EINVAL; 2553 2554 if (sll->sll_ifindex) { 2555 err = -ENODEV; 2556 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2557 if (dev == NULL) 2558 goto out; 2559 } 2560 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2561 2562 out: 2563 return err; 2564 } 2565 2566 static struct proto packet_proto = { 2567 .name = "PACKET", 2568 .owner = THIS_MODULE, 2569 .obj_size = sizeof(struct packet_sock), 2570 }; 2571 2572 /* 2573 * Create a packet of type SOCK_PACKET. 2574 */ 2575 2576 static int packet_create(struct net *net, struct socket *sock, int protocol, 2577 int kern) 2578 { 2579 struct sock *sk; 2580 struct packet_sock *po; 2581 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2582 int err; 2583 2584 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 2585 return -EPERM; 2586 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2587 sock->type != SOCK_PACKET) 2588 return -ESOCKTNOSUPPORT; 2589 2590 sock->state = SS_UNCONNECTED; 2591 2592 err = -ENOBUFS; 2593 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2594 if (sk == NULL) 2595 goto out; 2596 2597 sock->ops = &packet_ops; 2598 if (sock->type == SOCK_PACKET) 2599 sock->ops = &packet_ops_spkt; 2600 2601 sock_init_data(sock, sk); 2602 2603 po = pkt_sk(sk); 2604 sk->sk_family = PF_PACKET; 2605 po->num = proto; 2606 2607 sk->sk_destruct = packet_sock_destruct; 2608 sk_refcnt_debug_inc(sk); 2609 2610 /* 2611 * Attach a protocol block 2612 */ 2613 2614 spin_lock_init(&po->bind_lock); 2615 mutex_init(&po->pg_vec_lock); 2616 po->prot_hook.func = packet_rcv; 2617 2618 if (sock->type == SOCK_PACKET) 2619 po->prot_hook.func = packet_rcv_spkt; 2620 2621 po->prot_hook.af_packet_priv = sk; 2622 2623 if (proto) { 2624 po->prot_hook.type = proto; 2625 register_prot_hook(sk); 2626 } 2627 2628 mutex_lock(&net->packet.sklist_lock); 2629 sk_add_node_rcu(sk, &net->packet.sklist); 2630 mutex_unlock(&net->packet.sklist_lock); 2631 2632 preempt_disable(); 2633 sock_prot_inuse_add(net, &packet_proto, 1); 2634 preempt_enable(); 2635 2636 return 0; 2637 out: 2638 return err; 2639 } 2640 2641 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2642 { 2643 struct sock_exterr_skb *serr; 2644 struct sk_buff *skb, *skb2; 2645 int copied, err; 2646 2647 err = -EAGAIN; 2648 skb = skb_dequeue(&sk->sk_error_queue); 2649 if (skb == NULL) 2650 goto out; 2651 2652 copied = skb->len; 2653 if (copied > len) { 2654 msg->msg_flags |= MSG_TRUNC; 2655 copied = len; 2656 } 2657 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2658 if (err) 2659 goto out_free_skb; 2660 2661 sock_recv_timestamp(msg, sk, skb); 2662 2663 serr = SKB_EXT_ERR(skb); 2664 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2665 sizeof(serr->ee), &serr->ee); 2666 2667 msg->msg_flags |= MSG_ERRQUEUE; 2668 err = copied; 2669 2670 /* Reset and regenerate socket error */ 2671 spin_lock_bh(&sk->sk_error_queue.lock); 2672 sk->sk_err = 0; 2673 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2674 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2675 spin_unlock_bh(&sk->sk_error_queue.lock); 2676 sk->sk_error_report(sk); 2677 } else 2678 spin_unlock_bh(&sk->sk_error_queue.lock); 2679 2680 out_free_skb: 2681 kfree_skb(skb); 2682 out: 2683 return err; 2684 } 2685 2686 /* 2687 * Pull a packet from our receive queue and hand it to the user. 2688 * If necessary we block. 2689 */ 2690 2691 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2692 struct msghdr *msg, size_t len, int flags) 2693 { 2694 struct sock *sk = sock->sk; 2695 struct sk_buff *skb; 2696 int copied, err; 2697 struct sockaddr_ll *sll; 2698 int vnet_hdr_len = 0; 2699 2700 err = -EINVAL; 2701 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2702 goto out; 2703 2704 #if 0 2705 /* What error should we return now? EUNATTACH? */ 2706 if (pkt_sk(sk)->ifindex < 0) 2707 return -ENODEV; 2708 #endif 2709 2710 if (flags & MSG_ERRQUEUE) { 2711 err = packet_recv_error(sk, msg, len); 2712 goto out; 2713 } 2714 2715 /* 2716 * Call the generic datagram receiver. This handles all sorts 2717 * of horrible races and re-entrancy so we can forget about it 2718 * in the protocol layers. 2719 * 2720 * Now it will return ENETDOWN, if device have just gone down, 2721 * but then it will block. 2722 */ 2723 2724 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2725 2726 /* 2727 * An error occurred so return it. Because skb_recv_datagram() 2728 * handles the blocking we don't see and worry about blocking 2729 * retries. 2730 */ 2731 2732 if (skb == NULL) 2733 goto out; 2734 2735 if (pkt_sk(sk)->has_vnet_hdr) { 2736 struct virtio_net_hdr vnet_hdr = { 0 }; 2737 2738 err = -EINVAL; 2739 vnet_hdr_len = sizeof(vnet_hdr); 2740 if (len < vnet_hdr_len) 2741 goto out_free; 2742 2743 len -= vnet_hdr_len; 2744 2745 if (skb_is_gso(skb)) { 2746 struct skb_shared_info *sinfo = skb_shinfo(skb); 2747 2748 /* This is a hint as to how much should be linear. */ 2749 vnet_hdr.hdr_len = skb_headlen(skb); 2750 vnet_hdr.gso_size = sinfo->gso_size; 2751 if (sinfo->gso_type & SKB_GSO_TCPV4) 2752 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2753 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2754 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2755 else if (sinfo->gso_type & SKB_GSO_UDP) 2756 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2757 else if (sinfo->gso_type & SKB_GSO_FCOE) 2758 goto out_free; 2759 else 2760 BUG(); 2761 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2762 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2763 } else 2764 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2765 2766 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2767 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2768 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2769 vnet_hdr.csum_offset = skb->csum_offset; 2770 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2771 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2772 } /* else everything is zero */ 2773 2774 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2775 vnet_hdr_len); 2776 if (err < 0) 2777 goto out_free; 2778 } 2779 2780 /* 2781 * If the address length field is there to be filled in, we fill 2782 * it in now. 2783 */ 2784 2785 sll = &PACKET_SKB_CB(skb)->sa.ll; 2786 if (sock->type == SOCK_PACKET) 2787 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2788 else 2789 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2790 2791 /* 2792 * You lose any data beyond the buffer you gave. If it worries a 2793 * user program they can ask the device for its MTU anyway. 2794 */ 2795 2796 copied = skb->len; 2797 if (copied > len) { 2798 copied = len; 2799 msg->msg_flags |= MSG_TRUNC; 2800 } 2801 2802 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2803 if (err) 2804 goto out_free; 2805 2806 sock_recv_ts_and_drops(msg, sk, skb); 2807 2808 if (msg->msg_name) 2809 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2810 msg->msg_namelen); 2811 2812 if (pkt_sk(sk)->auxdata) { 2813 struct tpacket_auxdata aux; 2814 2815 aux.tp_status = TP_STATUS_USER; 2816 if (skb->ip_summed == CHECKSUM_PARTIAL) 2817 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2818 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2819 aux.tp_snaplen = skb->len; 2820 aux.tp_mac = 0; 2821 aux.tp_net = skb_network_offset(skb); 2822 if (vlan_tx_tag_present(skb)) { 2823 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2824 aux.tp_status |= TP_STATUS_VLAN_VALID; 2825 } else { 2826 aux.tp_vlan_tci = 0; 2827 } 2828 aux.tp_padding = 0; 2829 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2830 } 2831 2832 /* 2833 * Free or return the buffer as appropriate. Again this 2834 * hides all the races and re-entrancy issues from us. 2835 */ 2836 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2837 2838 out_free: 2839 skb_free_datagram(sk, skb); 2840 out: 2841 return err; 2842 } 2843 2844 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2845 int *uaddr_len, int peer) 2846 { 2847 struct net_device *dev; 2848 struct sock *sk = sock->sk; 2849 2850 if (peer) 2851 return -EOPNOTSUPP; 2852 2853 uaddr->sa_family = AF_PACKET; 2854 rcu_read_lock(); 2855 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2856 if (dev) 2857 strncpy(uaddr->sa_data, dev->name, 14); 2858 else 2859 memset(uaddr->sa_data, 0, 14); 2860 rcu_read_unlock(); 2861 *uaddr_len = sizeof(*uaddr); 2862 2863 return 0; 2864 } 2865 2866 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2867 int *uaddr_len, int peer) 2868 { 2869 struct net_device *dev; 2870 struct sock *sk = sock->sk; 2871 struct packet_sock *po = pkt_sk(sk); 2872 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2873 2874 if (peer) 2875 return -EOPNOTSUPP; 2876 2877 sll->sll_family = AF_PACKET; 2878 sll->sll_ifindex = po->ifindex; 2879 sll->sll_protocol = po->num; 2880 sll->sll_pkttype = 0; 2881 rcu_read_lock(); 2882 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2883 if (dev) { 2884 sll->sll_hatype = dev->type; 2885 sll->sll_halen = dev->addr_len; 2886 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2887 } else { 2888 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2889 sll->sll_halen = 0; 2890 } 2891 rcu_read_unlock(); 2892 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2893 2894 return 0; 2895 } 2896 2897 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2898 int what) 2899 { 2900 switch (i->type) { 2901 case PACKET_MR_MULTICAST: 2902 if (i->alen != dev->addr_len) 2903 return -EINVAL; 2904 if (what > 0) 2905 return dev_mc_add(dev, i->addr); 2906 else 2907 return dev_mc_del(dev, i->addr); 2908 break; 2909 case PACKET_MR_PROMISC: 2910 return dev_set_promiscuity(dev, what); 2911 break; 2912 case PACKET_MR_ALLMULTI: 2913 return dev_set_allmulti(dev, what); 2914 break; 2915 case PACKET_MR_UNICAST: 2916 if (i->alen != dev->addr_len) 2917 return -EINVAL; 2918 if (what > 0) 2919 return dev_uc_add(dev, i->addr); 2920 else 2921 return dev_uc_del(dev, i->addr); 2922 break; 2923 default: 2924 break; 2925 } 2926 return 0; 2927 } 2928 2929 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2930 { 2931 for ( ; i; i = i->next) { 2932 if (i->ifindex == dev->ifindex) 2933 packet_dev_mc(dev, i, what); 2934 } 2935 } 2936 2937 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2938 { 2939 struct packet_sock *po = pkt_sk(sk); 2940 struct packet_mclist *ml, *i; 2941 struct net_device *dev; 2942 int err; 2943 2944 rtnl_lock(); 2945 2946 err = -ENODEV; 2947 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2948 if (!dev) 2949 goto done; 2950 2951 err = -EINVAL; 2952 if (mreq->mr_alen > dev->addr_len) 2953 goto done; 2954 2955 err = -ENOBUFS; 2956 i = kmalloc(sizeof(*i), GFP_KERNEL); 2957 if (i == NULL) 2958 goto done; 2959 2960 err = 0; 2961 for (ml = po->mclist; ml; ml = ml->next) { 2962 if (ml->ifindex == mreq->mr_ifindex && 2963 ml->type == mreq->mr_type && 2964 ml->alen == mreq->mr_alen && 2965 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2966 ml->count++; 2967 /* Free the new element ... */ 2968 kfree(i); 2969 goto done; 2970 } 2971 } 2972 2973 i->type = mreq->mr_type; 2974 i->ifindex = mreq->mr_ifindex; 2975 i->alen = mreq->mr_alen; 2976 memcpy(i->addr, mreq->mr_address, i->alen); 2977 i->count = 1; 2978 i->next = po->mclist; 2979 po->mclist = i; 2980 err = packet_dev_mc(dev, i, 1); 2981 if (err) { 2982 po->mclist = i->next; 2983 kfree(i); 2984 } 2985 2986 done: 2987 rtnl_unlock(); 2988 return err; 2989 } 2990 2991 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2992 { 2993 struct packet_mclist *ml, **mlp; 2994 2995 rtnl_lock(); 2996 2997 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 2998 if (ml->ifindex == mreq->mr_ifindex && 2999 ml->type == mreq->mr_type && 3000 ml->alen == mreq->mr_alen && 3001 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3002 if (--ml->count == 0) { 3003 struct net_device *dev; 3004 *mlp = ml->next; 3005 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3006 if (dev) 3007 packet_dev_mc(dev, ml, -1); 3008 kfree(ml); 3009 } 3010 rtnl_unlock(); 3011 return 0; 3012 } 3013 } 3014 rtnl_unlock(); 3015 return -EADDRNOTAVAIL; 3016 } 3017 3018 static void packet_flush_mclist(struct sock *sk) 3019 { 3020 struct packet_sock *po = pkt_sk(sk); 3021 struct packet_mclist *ml; 3022 3023 if (!po->mclist) 3024 return; 3025 3026 rtnl_lock(); 3027 while ((ml = po->mclist) != NULL) { 3028 struct net_device *dev; 3029 3030 po->mclist = ml->next; 3031 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3032 if (dev != NULL) 3033 packet_dev_mc(dev, ml, -1); 3034 kfree(ml); 3035 } 3036 rtnl_unlock(); 3037 } 3038 3039 static int 3040 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3041 { 3042 struct sock *sk = sock->sk; 3043 struct packet_sock *po = pkt_sk(sk); 3044 int ret; 3045 3046 if (level != SOL_PACKET) 3047 return -ENOPROTOOPT; 3048 3049 switch (optname) { 3050 case PACKET_ADD_MEMBERSHIP: 3051 case PACKET_DROP_MEMBERSHIP: 3052 { 3053 struct packet_mreq_max mreq; 3054 int len = optlen; 3055 memset(&mreq, 0, sizeof(mreq)); 3056 if (len < sizeof(struct packet_mreq)) 3057 return -EINVAL; 3058 if (len > sizeof(mreq)) 3059 len = sizeof(mreq); 3060 if (copy_from_user(&mreq, optval, len)) 3061 return -EFAULT; 3062 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3063 return -EINVAL; 3064 if (optname == PACKET_ADD_MEMBERSHIP) 3065 ret = packet_mc_add(sk, &mreq); 3066 else 3067 ret = packet_mc_drop(sk, &mreq); 3068 return ret; 3069 } 3070 3071 case PACKET_RX_RING: 3072 case PACKET_TX_RING: 3073 { 3074 union tpacket_req_u req_u; 3075 int len; 3076 3077 switch (po->tp_version) { 3078 case TPACKET_V1: 3079 case TPACKET_V2: 3080 len = sizeof(req_u.req); 3081 break; 3082 case TPACKET_V3: 3083 default: 3084 len = sizeof(req_u.req3); 3085 break; 3086 } 3087 if (optlen < len) 3088 return -EINVAL; 3089 if (pkt_sk(sk)->has_vnet_hdr) 3090 return -EINVAL; 3091 if (copy_from_user(&req_u.req, optval, len)) 3092 return -EFAULT; 3093 return packet_set_ring(sk, &req_u, 0, 3094 optname == PACKET_TX_RING); 3095 } 3096 case PACKET_COPY_THRESH: 3097 { 3098 int val; 3099 3100 if (optlen != sizeof(val)) 3101 return -EINVAL; 3102 if (copy_from_user(&val, optval, sizeof(val))) 3103 return -EFAULT; 3104 3105 pkt_sk(sk)->copy_thresh = val; 3106 return 0; 3107 } 3108 case PACKET_VERSION: 3109 { 3110 int val; 3111 3112 if (optlen != sizeof(val)) 3113 return -EINVAL; 3114 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3115 return -EBUSY; 3116 if (copy_from_user(&val, optval, sizeof(val))) 3117 return -EFAULT; 3118 switch (val) { 3119 case TPACKET_V1: 3120 case TPACKET_V2: 3121 case TPACKET_V3: 3122 po->tp_version = val; 3123 return 0; 3124 default: 3125 return -EINVAL; 3126 } 3127 } 3128 case PACKET_RESERVE: 3129 { 3130 unsigned int val; 3131 3132 if (optlen != sizeof(val)) 3133 return -EINVAL; 3134 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3135 return -EBUSY; 3136 if (copy_from_user(&val, optval, sizeof(val))) 3137 return -EFAULT; 3138 po->tp_reserve = val; 3139 return 0; 3140 } 3141 case PACKET_LOSS: 3142 { 3143 unsigned int val; 3144 3145 if (optlen != sizeof(val)) 3146 return -EINVAL; 3147 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3148 return -EBUSY; 3149 if (copy_from_user(&val, optval, sizeof(val))) 3150 return -EFAULT; 3151 po->tp_loss = !!val; 3152 return 0; 3153 } 3154 case PACKET_AUXDATA: 3155 { 3156 int val; 3157 3158 if (optlen < sizeof(val)) 3159 return -EINVAL; 3160 if (copy_from_user(&val, optval, sizeof(val))) 3161 return -EFAULT; 3162 3163 po->auxdata = !!val; 3164 return 0; 3165 } 3166 case PACKET_ORIGDEV: 3167 { 3168 int val; 3169 3170 if (optlen < sizeof(val)) 3171 return -EINVAL; 3172 if (copy_from_user(&val, optval, sizeof(val))) 3173 return -EFAULT; 3174 3175 po->origdev = !!val; 3176 return 0; 3177 } 3178 case PACKET_VNET_HDR: 3179 { 3180 int val; 3181 3182 if (sock->type != SOCK_RAW) 3183 return -EINVAL; 3184 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3185 return -EBUSY; 3186 if (optlen < sizeof(val)) 3187 return -EINVAL; 3188 if (copy_from_user(&val, optval, sizeof(val))) 3189 return -EFAULT; 3190 3191 po->has_vnet_hdr = !!val; 3192 return 0; 3193 } 3194 case PACKET_TIMESTAMP: 3195 { 3196 int val; 3197 3198 if (optlen != sizeof(val)) 3199 return -EINVAL; 3200 if (copy_from_user(&val, optval, sizeof(val))) 3201 return -EFAULT; 3202 3203 po->tp_tstamp = val; 3204 return 0; 3205 } 3206 case PACKET_FANOUT: 3207 { 3208 int val; 3209 3210 if (optlen != sizeof(val)) 3211 return -EINVAL; 3212 if (copy_from_user(&val, optval, sizeof(val))) 3213 return -EFAULT; 3214 3215 return fanout_add(sk, val & 0xffff, val >> 16); 3216 } 3217 case PACKET_TX_HAS_OFF: 3218 { 3219 unsigned int val; 3220 3221 if (optlen != sizeof(val)) 3222 return -EINVAL; 3223 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3224 return -EBUSY; 3225 if (copy_from_user(&val, optval, sizeof(val))) 3226 return -EFAULT; 3227 po->tp_tx_has_off = !!val; 3228 return 0; 3229 } 3230 default: 3231 return -ENOPROTOOPT; 3232 } 3233 } 3234 3235 static int packet_getsockopt(struct socket *sock, int level, int optname, 3236 char __user *optval, int __user *optlen) 3237 { 3238 int len; 3239 int val, lv = sizeof(val); 3240 struct sock *sk = sock->sk; 3241 struct packet_sock *po = pkt_sk(sk); 3242 void *data = &val; 3243 union tpacket_stats_u st; 3244 3245 if (level != SOL_PACKET) 3246 return -ENOPROTOOPT; 3247 3248 if (get_user(len, optlen)) 3249 return -EFAULT; 3250 3251 if (len < 0) 3252 return -EINVAL; 3253 3254 switch (optname) { 3255 case PACKET_STATISTICS: 3256 spin_lock_bh(&sk->sk_receive_queue.lock); 3257 memcpy(&st, &po->stats, sizeof(st)); 3258 memset(&po->stats, 0, sizeof(po->stats)); 3259 spin_unlock_bh(&sk->sk_receive_queue.lock); 3260 3261 if (po->tp_version == TPACKET_V3) { 3262 lv = sizeof(struct tpacket_stats_v3); 3263 data = &st.stats3; 3264 } else { 3265 lv = sizeof(struct tpacket_stats); 3266 data = &st.stats1; 3267 } 3268 3269 break; 3270 case PACKET_AUXDATA: 3271 val = po->auxdata; 3272 break; 3273 case PACKET_ORIGDEV: 3274 val = po->origdev; 3275 break; 3276 case PACKET_VNET_HDR: 3277 val = po->has_vnet_hdr; 3278 break; 3279 case PACKET_VERSION: 3280 val = po->tp_version; 3281 break; 3282 case PACKET_HDRLEN: 3283 if (len > sizeof(int)) 3284 len = sizeof(int); 3285 if (copy_from_user(&val, optval, len)) 3286 return -EFAULT; 3287 switch (val) { 3288 case TPACKET_V1: 3289 val = sizeof(struct tpacket_hdr); 3290 break; 3291 case TPACKET_V2: 3292 val = sizeof(struct tpacket2_hdr); 3293 break; 3294 case TPACKET_V3: 3295 val = sizeof(struct tpacket3_hdr); 3296 break; 3297 default: 3298 return -EINVAL; 3299 } 3300 break; 3301 case PACKET_RESERVE: 3302 val = po->tp_reserve; 3303 break; 3304 case PACKET_LOSS: 3305 val = po->tp_loss; 3306 break; 3307 case PACKET_TIMESTAMP: 3308 val = po->tp_tstamp; 3309 break; 3310 case PACKET_FANOUT: 3311 val = (po->fanout ? 3312 ((u32)po->fanout->id | 3313 ((u32)po->fanout->type << 16) | 3314 ((u32)po->fanout->flags << 24)) : 3315 0); 3316 break; 3317 case PACKET_TX_HAS_OFF: 3318 val = po->tp_tx_has_off; 3319 break; 3320 default: 3321 return -ENOPROTOOPT; 3322 } 3323 3324 if (len > lv) 3325 len = lv; 3326 if (put_user(len, optlen)) 3327 return -EFAULT; 3328 if (copy_to_user(optval, data, len)) 3329 return -EFAULT; 3330 return 0; 3331 } 3332 3333 3334 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3335 { 3336 struct sock *sk; 3337 struct net_device *dev = data; 3338 struct net *net = dev_net(dev); 3339 3340 rcu_read_lock(); 3341 sk_for_each_rcu(sk, &net->packet.sklist) { 3342 struct packet_sock *po = pkt_sk(sk); 3343 3344 switch (msg) { 3345 case NETDEV_UNREGISTER: 3346 if (po->mclist) 3347 packet_dev_mclist(dev, po->mclist, -1); 3348 /* fallthrough */ 3349 3350 case NETDEV_DOWN: 3351 if (dev->ifindex == po->ifindex) { 3352 spin_lock(&po->bind_lock); 3353 if (po->running) { 3354 __unregister_prot_hook(sk, false); 3355 sk->sk_err = ENETDOWN; 3356 if (!sock_flag(sk, SOCK_DEAD)) 3357 sk->sk_error_report(sk); 3358 } 3359 if (msg == NETDEV_UNREGISTER) { 3360 po->ifindex = -1; 3361 if (po->prot_hook.dev) 3362 dev_put(po->prot_hook.dev); 3363 po->prot_hook.dev = NULL; 3364 } 3365 spin_unlock(&po->bind_lock); 3366 } 3367 break; 3368 case NETDEV_UP: 3369 if (dev->ifindex == po->ifindex) { 3370 spin_lock(&po->bind_lock); 3371 if (po->num) 3372 register_prot_hook(sk); 3373 spin_unlock(&po->bind_lock); 3374 } 3375 break; 3376 } 3377 } 3378 rcu_read_unlock(); 3379 return NOTIFY_DONE; 3380 } 3381 3382 3383 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3384 unsigned long arg) 3385 { 3386 struct sock *sk = sock->sk; 3387 3388 switch (cmd) { 3389 case SIOCOUTQ: 3390 { 3391 int amount = sk_wmem_alloc_get(sk); 3392 3393 return put_user(amount, (int __user *)arg); 3394 } 3395 case SIOCINQ: 3396 { 3397 struct sk_buff *skb; 3398 int amount = 0; 3399 3400 spin_lock_bh(&sk->sk_receive_queue.lock); 3401 skb = skb_peek(&sk->sk_receive_queue); 3402 if (skb) 3403 amount = skb->len; 3404 spin_unlock_bh(&sk->sk_receive_queue.lock); 3405 return put_user(amount, (int __user *)arg); 3406 } 3407 case SIOCGSTAMP: 3408 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3409 case SIOCGSTAMPNS: 3410 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3411 3412 #ifdef CONFIG_INET 3413 case SIOCADDRT: 3414 case SIOCDELRT: 3415 case SIOCDARP: 3416 case SIOCGARP: 3417 case SIOCSARP: 3418 case SIOCGIFADDR: 3419 case SIOCSIFADDR: 3420 case SIOCGIFBRDADDR: 3421 case SIOCSIFBRDADDR: 3422 case SIOCGIFNETMASK: 3423 case SIOCSIFNETMASK: 3424 case SIOCGIFDSTADDR: 3425 case SIOCSIFDSTADDR: 3426 case SIOCSIFFLAGS: 3427 return inet_dgram_ops.ioctl(sock, cmd, arg); 3428 #endif 3429 3430 default: 3431 return -ENOIOCTLCMD; 3432 } 3433 return 0; 3434 } 3435 3436 static unsigned int packet_poll(struct file *file, struct socket *sock, 3437 poll_table *wait) 3438 { 3439 struct sock *sk = sock->sk; 3440 struct packet_sock *po = pkt_sk(sk); 3441 unsigned int mask = datagram_poll(file, sock, wait); 3442 3443 spin_lock_bh(&sk->sk_receive_queue.lock); 3444 if (po->rx_ring.pg_vec) { 3445 if (!packet_previous_rx_frame(po, &po->rx_ring, 3446 TP_STATUS_KERNEL)) 3447 mask |= POLLIN | POLLRDNORM; 3448 } 3449 spin_unlock_bh(&sk->sk_receive_queue.lock); 3450 spin_lock_bh(&sk->sk_write_queue.lock); 3451 if (po->tx_ring.pg_vec) { 3452 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3453 mask |= POLLOUT | POLLWRNORM; 3454 } 3455 spin_unlock_bh(&sk->sk_write_queue.lock); 3456 return mask; 3457 } 3458 3459 3460 /* Dirty? Well, I still did not learn better way to account 3461 * for user mmaps. 3462 */ 3463 3464 static void packet_mm_open(struct vm_area_struct *vma) 3465 { 3466 struct file *file = vma->vm_file; 3467 struct socket *sock = file->private_data; 3468 struct sock *sk = sock->sk; 3469 3470 if (sk) 3471 atomic_inc(&pkt_sk(sk)->mapped); 3472 } 3473 3474 static void packet_mm_close(struct vm_area_struct *vma) 3475 { 3476 struct file *file = vma->vm_file; 3477 struct socket *sock = file->private_data; 3478 struct sock *sk = sock->sk; 3479 3480 if (sk) 3481 atomic_dec(&pkt_sk(sk)->mapped); 3482 } 3483 3484 static const struct vm_operations_struct packet_mmap_ops = { 3485 .open = packet_mm_open, 3486 .close = packet_mm_close, 3487 }; 3488 3489 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3490 unsigned int len) 3491 { 3492 int i; 3493 3494 for (i = 0; i < len; i++) { 3495 if (likely(pg_vec[i].buffer)) { 3496 if (is_vmalloc_addr(pg_vec[i].buffer)) 3497 vfree(pg_vec[i].buffer); 3498 else 3499 free_pages((unsigned long)pg_vec[i].buffer, 3500 order); 3501 pg_vec[i].buffer = NULL; 3502 } 3503 } 3504 kfree(pg_vec); 3505 } 3506 3507 static char *alloc_one_pg_vec_page(unsigned long order) 3508 { 3509 char *buffer = NULL; 3510 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3511 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3512 3513 buffer = (char *) __get_free_pages(gfp_flags, order); 3514 3515 if (buffer) 3516 return buffer; 3517 3518 /* 3519 * __get_free_pages failed, fall back to vmalloc 3520 */ 3521 buffer = vzalloc((1 << order) * PAGE_SIZE); 3522 3523 if (buffer) 3524 return buffer; 3525 3526 /* 3527 * vmalloc failed, lets dig into swap here 3528 */ 3529 gfp_flags &= ~__GFP_NORETRY; 3530 buffer = (char *)__get_free_pages(gfp_flags, order); 3531 if (buffer) 3532 return buffer; 3533 3534 /* 3535 * complete and utter failure 3536 */ 3537 return NULL; 3538 } 3539 3540 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3541 { 3542 unsigned int block_nr = req->tp_block_nr; 3543 struct pgv *pg_vec; 3544 int i; 3545 3546 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3547 if (unlikely(!pg_vec)) 3548 goto out; 3549 3550 for (i = 0; i < block_nr; i++) { 3551 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3552 if (unlikely(!pg_vec[i].buffer)) 3553 goto out_free_pgvec; 3554 } 3555 3556 out: 3557 return pg_vec; 3558 3559 out_free_pgvec: 3560 free_pg_vec(pg_vec, order, block_nr); 3561 pg_vec = NULL; 3562 goto out; 3563 } 3564 3565 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3566 int closing, int tx_ring) 3567 { 3568 struct pgv *pg_vec = NULL; 3569 struct packet_sock *po = pkt_sk(sk); 3570 int was_running, order = 0; 3571 struct packet_ring_buffer *rb; 3572 struct sk_buff_head *rb_queue; 3573 __be16 num; 3574 int err = -EINVAL; 3575 /* Added to avoid minimal code churn */ 3576 struct tpacket_req *req = &req_u->req; 3577 3578 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3579 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3580 WARN(1, "Tx-ring is not supported.\n"); 3581 goto out; 3582 } 3583 3584 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3585 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3586 3587 err = -EBUSY; 3588 if (!closing) { 3589 if (atomic_read(&po->mapped)) 3590 goto out; 3591 if (atomic_read(&rb->pending)) 3592 goto out; 3593 } 3594 3595 if (req->tp_block_nr) { 3596 /* Sanity tests and some calculations */ 3597 err = -EBUSY; 3598 if (unlikely(rb->pg_vec)) 3599 goto out; 3600 3601 switch (po->tp_version) { 3602 case TPACKET_V1: 3603 po->tp_hdrlen = TPACKET_HDRLEN; 3604 break; 3605 case TPACKET_V2: 3606 po->tp_hdrlen = TPACKET2_HDRLEN; 3607 break; 3608 case TPACKET_V3: 3609 po->tp_hdrlen = TPACKET3_HDRLEN; 3610 break; 3611 } 3612 3613 err = -EINVAL; 3614 if (unlikely((int)req->tp_block_size <= 0)) 3615 goto out; 3616 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3617 goto out; 3618 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3619 po->tp_reserve)) 3620 goto out; 3621 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3622 goto out; 3623 3624 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3625 if (unlikely(rb->frames_per_block <= 0)) 3626 goto out; 3627 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3628 req->tp_frame_nr)) 3629 goto out; 3630 3631 err = -ENOMEM; 3632 order = get_order(req->tp_block_size); 3633 pg_vec = alloc_pg_vec(req, order); 3634 if (unlikely(!pg_vec)) 3635 goto out; 3636 switch (po->tp_version) { 3637 case TPACKET_V3: 3638 /* Transmit path is not supported. We checked 3639 * it above but just being paranoid 3640 */ 3641 if (!tx_ring) 3642 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3643 break; 3644 default: 3645 break; 3646 } 3647 } 3648 /* Done */ 3649 else { 3650 err = -EINVAL; 3651 if (unlikely(req->tp_frame_nr)) 3652 goto out; 3653 } 3654 3655 lock_sock(sk); 3656 3657 /* Detach socket from network */ 3658 spin_lock(&po->bind_lock); 3659 was_running = po->running; 3660 num = po->num; 3661 if (was_running) { 3662 po->num = 0; 3663 __unregister_prot_hook(sk, false); 3664 } 3665 spin_unlock(&po->bind_lock); 3666 3667 synchronize_net(); 3668 3669 err = -EBUSY; 3670 mutex_lock(&po->pg_vec_lock); 3671 if (closing || atomic_read(&po->mapped) == 0) { 3672 err = 0; 3673 spin_lock_bh(&rb_queue->lock); 3674 swap(rb->pg_vec, pg_vec); 3675 rb->frame_max = (req->tp_frame_nr - 1); 3676 rb->head = 0; 3677 rb->frame_size = req->tp_frame_size; 3678 spin_unlock_bh(&rb_queue->lock); 3679 3680 swap(rb->pg_vec_order, order); 3681 swap(rb->pg_vec_len, req->tp_block_nr); 3682 3683 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3684 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3685 tpacket_rcv : packet_rcv; 3686 skb_queue_purge(rb_queue); 3687 if (atomic_read(&po->mapped)) 3688 pr_err("packet_mmap: vma is busy: %d\n", 3689 atomic_read(&po->mapped)); 3690 } 3691 mutex_unlock(&po->pg_vec_lock); 3692 3693 spin_lock(&po->bind_lock); 3694 if (was_running) { 3695 po->num = num; 3696 register_prot_hook(sk); 3697 } 3698 spin_unlock(&po->bind_lock); 3699 if (closing && (po->tp_version > TPACKET_V2)) { 3700 /* Because we don't support block-based V3 on tx-ring */ 3701 if (!tx_ring) 3702 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3703 } 3704 release_sock(sk); 3705 3706 if (pg_vec) 3707 free_pg_vec(pg_vec, order, req->tp_block_nr); 3708 out: 3709 return err; 3710 } 3711 3712 static int packet_mmap(struct file *file, struct socket *sock, 3713 struct vm_area_struct *vma) 3714 { 3715 struct sock *sk = sock->sk; 3716 struct packet_sock *po = pkt_sk(sk); 3717 unsigned long size, expected_size; 3718 struct packet_ring_buffer *rb; 3719 unsigned long start; 3720 int err = -EINVAL; 3721 int i; 3722 3723 if (vma->vm_pgoff) 3724 return -EINVAL; 3725 3726 mutex_lock(&po->pg_vec_lock); 3727 3728 expected_size = 0; 3729 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3730 if (rb->pg_vec) { 3731 expected_size += rb->pg_vec_len 3732 * rb->pg_vec_pages 3733 * PAGE_SIZE; 3734 } 3735 } 3736 3737 if (expected_size == 0) 3738 goto out; 3739 3740 size = vma->vm_end - vma->vm_start; 3741 if (size != expected_size) 3742 goto out; 3743 3744 start = vma->vm_start; 3745 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3746 if (rb->pg_vec == NULL) 3747 continue; 3748 3749 for (i = 0; i < rb->pg_vec_len; i++) { 3750 struct page *page; 3751 void *kaddr = rb->pg_vec[i].buffer; 3752 int pg_num; 3753 3754 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3755 page = pgv_to_page(kaddr); 3756 err = vm_insert_page(vma, start, page); 3757 if (unlikely(err)) 3758 goto out; 3759 start += PAGE_SIZE; 3760 kaddr += PAGE_SIZE; 3761 } 3762 } 3763 } 3764 3765 atomic_inc(&po->mapped); 3766 vma->vm_ops = &packet_mmap_ops; 3767 err = 0; 3768 3769 out: 3770 mutex_unlock(&po->pg_vec_lock); 3771 return err; 3772 } 3773 3774 static const struct proto_ops packet_ops_spkt = { 3775 .family = PF_PACKET, 3776 .owner = THIS_MODULE, 3777 .release = packet_release, 3778 .bind = packet_bind_spkt, 3779 .connect = sock_no_connect, 3780 .socketpair = sock_no_socketpair, 3781 .accept = sock_no_accept, 3782 .getname = packet_getname_spkt, 3783 .poll = datagram_poll, 3784 .ioctl = packet_ioctl, 3785 .listen = sock_no_listen, 3786 .shutdown = sock_no_shutdown, 3787 .setsockopt = sock_no_setsockopt, 3788 .getsockopt = sock_no_getsockopt, 3789 .sendmsg = packet_sendmsg_spkt, 3790 .recvmsg = packet_recvmsg, 3791 .mmap = sock_no_mmap, 3792 .sendpage = sock_no_sendpage, 3793 }; 3794 3795 static const struct proto_ops packet_ops = { 3796 .family = PF_PACKET, 3797 .owner = THIS_MODULE, 3798 .release = packet_release, 3799 .bind = packet_bind, 3800 .connect = sock_no_connect, 3801 .socketpair = sock_no_socketpair, 3802 .accept = sock_no_accept, 3803 .getname = packet_getname, 3804 .poll = packet_poll, 3805 .ioctl = packet_ioctl, 3806 .listen = sock_no_listen, 3807 .shutdown = sock_no_shutdown, 3808 .setsockopt = packet_setsockopt, 3809 .getsockopt = packet_getsockopt, 3810 .sendmsg = packet_sendmsg, 3811 .recvmsg = packet_recvmsg, 3812 .mmap = packet_mmap, 3813 .sendpage = sock_no_sendpage, 3814 }; 3815 3816 static const struct net_proto_family packet_family_ops = { 3817 .family = PF_PACKET, 3818 .create = packet_create, 3819 .owner = THIS_MODULE, 3820 }; 3821 3822 static struct notifier_block packet_netdev_notifier = { 3823 .notifier_call = packet_notifier, 3824 }; 3825 3826 #ifdef CONFIG_PROC_FS 3827 3828 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3829 __acquires(RCU) 3830 { 3831 struct net *net = seq_file_net(seq); 3832 3833 rcu_read_lock(); 3834 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3835 } 3836 3837 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3838 { 3839 struct net *net = seq_file_net(seq); 3840 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3841 } 3842 3843 static void packet_seq_stop(struct seq_file *seq, void *v) 3844 __releases(RCU) 3845 { 3846 rcu_read_unlock(); 3847 } 3848 3849 static int packet_seq_show(struct seq_file *seq, void *v) 3850 { 3851 if (v == SEQ_START_TOKEN) 3852 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3853 else { 3854 struct sock *s = sk_entry(v); 3855 const struct packet_sock *po = pkt_sk(s); 3856 3857 seq_printf(seq, 3858 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3859 s, 3860 atomic_read(&s->sk_refcnt), 3861 s->sk_type, 3862 ntohs(po->num), 3863 po->ifindex, 3864 po->running, 3865 atomic_read(&s->sk_rmem_alloc), 3866 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 3867 sock_i_ino(s)); 3868 } 3869 3870 return 0; 3871 } 3872 3873 static const struct seq_operations packet_seq_ops = { 3874 .start = packet_seq_start, 3875 .next = packet_seq_next, 3876 .stop = packet_seq_stop, 3877 .show = packet_seq_show, 3878 }; 3879 3880 static int packet_seq_open(struct inode *inode, struct file *file) 3881 { 3882 return seq_open_net(inode, file, &packet_seq_ops, 3883 sizeof(struct seq_net_private)); 3884 } 3885 3886 static const struct file_operations packet_seq_fops = { 3887 .owner = THIS_MODULE, 3888 .open = packet_seq_open, 3889 .read = seq_read, 3890 .llseek = seq_lseek, 3891 .release = seq_release_net, 3892 }; 3893 3894 #endif 3895 3896 static int __net_init packet_net_init(struct net *net) 3897 { 3898 mutex_init(&net->packet.sklist_lock); 3899 INIT_HLIST_HEAD(&net->packet.sklist); 3900 3901 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 3902 return -ENOMEM; 3903 3904 return 0; 3905 } 3906 3907 static void __net_exit packet_net_exit(struct net *net) 3908 { 3909 remove_proc_entry("packet", net->proc_net); 3910 } 3911 3912 static struct pernet_operations packet_net_ops = { 3913 .init = packet_net_init, 3914 .exit = packet_net_exit, 3915 }; 3916 3917 3918 static void __exit packet_exit(void) 3919 { 3920 unregister_netdevice_notifier(&packet_netdev_notifier); 3921 unregister_pernet_subsys(&packet_net_ops); 3922 sock_unregister(PF_PACKET); 3923 proto_unregister(&packet_proto); 3924 } 3925 3926 static int __init packet_init(void) 3927 { 3928 int rc = proto_register(&packet_proto, 0); 3929 3930 if (rc != 0) 3931 goto out; 3932 3933 sock_register(&packet_family_ops); 3934 register_pernet_subsys(&packet_net_ops); 3935 register_netdevice_notifier(&packet_netdev_notifier); 3936 out: 3937 return rc; 3938 } 3939 3940 module_init(packet_init); 3941 module_exit(packet_exit); 3942 MODULE_LICENSE("GPL"); 3943 MODULE_ALIAS_NETPROTO(PF_PACKET); 3944