1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <asm/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/reciprocal_div.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 96 #include "internal.h" 97 98 /* 99 Assumptions: 100 - if device has no dev->hard_header routine, it adds and removes ll header 101 inside itself. In this case ll header is invisible outside of device, 102 but higher levels still should reserve dev->hard_header_len. 103 Some devices are enough clever to reallocate skb, when header 104 will not fit to reserved space (tunnel), another ones are silly 105 (PPP). 106 - packet socket receives packets with pulled ll header, 107 so that SOCK_RAW should push it back. 108 109 On receive: 110 ----------- 111 112 Incoming, dev->hard_header!=NULL 113 mac_header -> ll header 114 data -> data 115 116 Outgoing, dev->hard_header!=NULL 117 mac_header -> ll header 118 data -> ll header 119 120 Incoming, dev->hard_header==NULL 121 mac_header -> UNKNOWN position. It is very likely, that it points to ll 122 header. PPP makes it, that is wrong, because introduce 123 assymetry between rx and tx paths. 124 data -> data 125 126 Outgoing, dev->hard_header==NULL 127 mac_header -> data. ll header is still not built! 128 data -> data 129 130 Resume 131 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 132 133 134 On transmit: 135 ------------ 136 137 dev->hard_header != NULL 138 mac_header -> ll header 139 data -> ll header 140 141 dev->hard_header == NULL (ll header is added by device, we cannot control it) 142 mac_header -> data 143 data -> data 144 145 We should set nh.raw on output to correct posistion, 146 packet classifier depends on it. 147 */ 148 149 /* Private packet socket structures. */ 150 151 /* identical to struct packet_mreq except it has 152 * a longer address field. 153 */ 154 struct packet_mreq_max { 155 int mr_ifindex; 156 unsigned short mr_type; 157 unsigned short mr_alen; 158 unsigned char mr_address[MAX_ADDR_LEN]; 159 }; 160 161 union tpacket_uhdr { 162 struct tpacket_hdr *h1; 163 struct tpacket2_hdr *h2; 164 struct tpacket3_hdr *h3; 165 void *raw; 166 }; 167 168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 169 int closing, int tx_ring); 170 171 #define V3_ALIGNMENT (8) 172 173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 174 175 #define BLK_PLUS_PRIV(sz_of_priv) \ 176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 177 178 #define PGV_FROM_VMALLOC 1 179 180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 187 188 struct packet_sock; 189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 191 struct packet_type *pt, struct net_device *orig_dev); 192 193 static void *packet_previous_frame(struct packet_sock *po, 194 struct packet_ring_buffer *rb, 195 int status); 196 static void packet_increment_head(struct packet_ring_buffer *buff); 197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 198 struct tpacket_block_desc *); 199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 200 struct packet_sock *); 201 static void prb_retire_current_block(struct tpacket_kbdq_core *, 202 struct packet_sock *, unsigned int status); 203 static int prb_queue_frozen(struct tpacket_kbdq_core *); 204 static void prb_open_block(struct tpacket_kbdq_core *, 205 struct tpacket_block_desc *); 206 static void prb_retire_rx_blk_timer_expired(unsigned long); 207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 208 static void prb_init_blk_timer(struct packet_sock *, 209 struct tpacket_kbdq_core *, 210 void (*func) (unsigned long)); 211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 212 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 213 struct tpacket3_hdr *); 214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 215 struct tpacket3_hdr *); 216 static void packet_flush_mclist(struct sock *sk); 217 218 struct packet_skb_cb { 219 unsigned int origlen; 220 union { 221 struct sockaddr_pkt pkt; 222 struct sockaddr_ll ll; 223 } sa; 224 }; 225 226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 227 228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 229 #define GET_PBLOCK_DESC(x, bid) \ 230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 233 #define GET_NEXT_PRB_BLK_NUM(x) \ 234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 235 ((x)->kactive_blk_num+1) : 0) 236 237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 238 static void __fanout_link(struct sock *sk, struct packet_sock *po); 239 240 /* 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); 247 248 if (!po->running) { 249 if (po->fanout) { 250 __fanout_link(sk, po); 251 } else { 252 dev_add_pack(&po->prot_hook); 253 rcu_assign_pointer(po->cached_dev, po->prot_hook.dev); 254 } 255 256 sock_hold(sk); 257 po->running = 1; 258 } 259 } 260 261 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 262 * held. If the sync parameter is true, we will temporarily drop 263 * the po->bind_lock and do a synchronize_net to make sure no 264 * asynchronous packet processing paths still refer to the elements 265 * of po->prot_hook. If the sync parameter is false, it is the 266 * callers responsibility to take care of this. 267 */ 268 static void __unregister_prot_hook(struct sock *sk, bool sync) 269 { 270 struct packet_sock *po = pkt_sk(sk); 271 272 po->running = 0; 273 if (po->fanout) { 274 __fanout_unlink(sk, po); 275 } else { 276 __dev_remove_pack(&po->prot_hook); 277 RCU_INIT_POINTER(po->cached_dev, NULL); 278 } 279 280 __sock_put(sk); 281 282 if (sync) { 283 spin_unlock(&po->bind_lock); 284 synchronize_net(); 285 spin_lock(&po->bind_lock); 286 } 287 } 288 289 static void unregister_prot_hook(struct sock *sk, bool sync) 290 { 291 struct packet_sock *po = pkt_sk(sk); 292 293 if (po->running) 294 __unregister_prot_hook(sk, sync); 295 } 296 297 static inline __pure struct page *pgv_to_page(void *addr) 298 { 299 if (is_vmalloc_addr(addr)) 300 return vmalloc_to_page(addr); 301 return virt_to_page(addr); 302 } 303 304 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 305 { 306 union tpacket_uhdr h; 307 308 h.raw = frame; 309 switch (po->tp_version) { 310 case TPACKET_V1: 311 h.h1->tp_status = status; 312 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 313 break; 314 case TPACKET_V2: 315 h.h2->tp_status = status; 316 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 317 break; 318 case TPACKET_V3: 319 default: 320 WARN(1, "TPACKET version not supported.\n"); 321 BUG(); 322 } 323 324 smp_wmb(); 325 } 326 327 static int __packet_get_status(struct packet_sock *po, void *frame) 328 { 329 union tpacket_uhdr h; 330 331 smp_rmb(); 332 333 h.raw = frame; 334 switch (po->tp_version) { 335 case TPACKET_V1: 336 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 337 return h.h1->tp_status; 338 case TPACKET_V2: 339 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 340 return h.h2->tp_status; 341 case TPACKET_V3: 342 default: 343 WARN(1, "TPACKET version not supported.\n"); 344 BUG(); 345 return 0; 346 } 347 } 348 349 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 350 unsigned int flags) 351 { 352 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 353 354 if (shhwtstamps) { 355 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) && 356 ktime_to_timespec_cond(shhwtstamps->syststamp, ts)) 357 return TP_STATUS_TS_SYS_HARDWARE; 358 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 359 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 360 return TP_STATUS_TS_RAW_HARDWARE; 361 } 362 363 if (ktime_to_timespec_cond(skb->tstamp, ts)) 364 return TP_STATUS_TS_SOFTWARE; 365 366 return 0; 367 } 368 369 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 370 struct sk_buff *skb) 371 { 372 union tpacket_uhdr h; 373 struct timespec ts; 374 __u32 ts_status; 375 376 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 377 return 0; 378 379 h.raw = frame; 380 switch (po->tp_version) { 381 case TPACKET_V1: 382 h.h1->tp_sec = ts.tv_sec; 383 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 384 break; 385 case TPACKET_V2: 386 h.h2->tp_sec = ts.tv_sec; 387 h.h2->tp_nsec = ts.tv_nsec; 388 break; 389 case TPACKET_V3: 390 default: 391 WARN(1, "TPACKET version not supported.\n"); 392 BUG(); 393 } 394 395 /* one flush is safe, as both fields always lie on the same cacheline */ 396 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 397 smp_wmb(); 398 399 return ts_status; 400 } 401 402 static void *packet_lookup_frame(struct packet_sock *po, 403 struct packet_ring_buffer *rb, 404 unsigned int position, 405 int status) 406 { 407 unsigned int pg_vec_pos, frame_offset; 408 union tpacket_uhdr h; 409 410 pg_vec_pos = position / rb->frames_per_block; 411 frame_offset = position % rb->frames_per_block; 412 413 h.raw = rb->pg_vec[pg_vec_pos].buffer + 414 (frame_offset * rb->frame_size); 415 416 if (status != __packet_get_status(po, h.raw)) 417 return NULL; 418 419 return h.raw; 420 } 421 422 static void *packet_current_frame(struct packet_sock *po, 423 struct packet_ring_buffer *rb, 424 int status) 425 { 426 return packet_lookup_frame(po, rb, rb->head, status); 427 } 428 429 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 430 { 431 del_timer_sync(&pkc->retire_blk_timer); 432 } 433 434 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 435 int tx_ring, 436 struct sk_buff_head *rb_queue) 437 { 438 struct tpacket_kbdq_core *pkc; 439 440 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 441 442 spin_lock(&rb_queue->lock); 443 pkc->delete_blk_timer = 1; 444 spin_unlock(&rb_queue->lock); 445 446 prb_del_retire_blk_timer(pkc); 447 } 448 449 static void prb_init_blk_timer(struct packet_sock *po, 450 struct tpacket_kbdq_core *pkc, 451 void (*func) (unsigned long)) 452 { 453 init_timer(&pkc->retire_blk_timer); 454 pkc->retire_blk_timer.data = (long)po; 455 pkc->retire_blk_timer.function = func; 456 pkc->retire_blk_timer.expires = jiffies; 457 } 458 459 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 460 { 461 struct tpacket_kbdq_core *pkc; 462 463 if (tx_ring) 464 BUG(); 465 466 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 467 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 468 } 469 470 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 471 int blk_size_in_bytes) 472 { 473 struct net_device *dev; 474 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 475 struct ethtool_cmd ecmd; 476 int err; 477 u32 speed; 478 479 rtnl_lock(); 480 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 481 if (unlikely(!dev)) { 482 rtnl_unlock(); 483 return DEFAULT_PRB_RETIRE_TOV; 484 } 485 err = __ethtool_get_settings(dev, &ecmd); 486 speed = ethtool_cmd_speed(&ecmd); 487 rtnl_unlock(); 488 if (!err) { 489 /* 490 * If the link speed is so slow you don't really 491 * need to worry about perf anyways 492 */ 493 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 494 return DEFAULT_PRB_RETIRE_TOV; 495 } else { 496 msec = 1; 497 div = speed / 1000; 498 } 499 } 500 501 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 502 503 if (div) 504 mbits /= div; 505 506 tmo = mbits * msec; 507 508 if (div) 509 return tmo+1; 510 return tmo; 511 } 512 513 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 514 union tpacket_req_u *req_u) 515 { 516 p1->feature_req_word = req_u->req3.tp_feature_req_word; 517 } 518 519 static void init_prb_bdqc(struct packet_sock *po, 520 struct packet_ring_buffer *rb, 521 struct pgv *pg_vec, 522 union tpacket_req_u *req_u, int tx_ring) 523 { 524 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 525 struct tpacket_block_desc *pbd; 526 527 memset(p1, 0x0, sizeof(*p1)); 528 529 p1->knxt_seq_num = 1; 530 p1->pkbdq = pg_vec; 531 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 532 p1->pkblk_start = pg_vec[0].buffer; 533 p1->kblk_size = req_u->req3.tp_block_size; 534 p1->knum_blocks = req_u->req3.tp_block_nr; 535 p1->hdrlen = po->tp_hdrlen; 536 p1->version = po->tp_version; 537 p1->last_kactive_blk_num = 0; 538 po->stats.stats3.tp_freeze_q_cnt = 0; 539 if (req_u->req3.tp_retire_blk_tov) 540 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 541 else 542 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 543 req_u->req3.tp_block_size); 544 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 545 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 546 547 prb_init_ft_ops(p1, req_u); 548 prb_setup_retire_blk_timer(po, tx_ring); 549 prb_open_block(p1, pbd); 550 } 551 552 /* Do NOT update the last_blk_num first. 553 * Assumes sk_buff_head lock is held. 554 */ 555 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 556 { 557 mod_timer(&pkc->retire_blk_timer, 558 jiffies + pkc->tov_in_jiffies); 559 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 560 } 561 562 /* 563 * Timer logic: 564 * 1) We refresh the timer only when we open a block. 565 * By doing this we don't waste cycles refreshing the timer 566 * on packet-by-packet basis. 567 * 568 * With a 1MB block-size, on a 1Gbps line, it will take 569 * i) ~8 ms to fill a block + ii) memcpy etc. 570 * In this cut we are not accounting for the memcpy time. 571 * 572 * So, if the user sets the 'tmo' to 10ms then the timer 573 * will never fire while the block is still getting filled 574 * (which is what we want). However, the user could choose 575 * to close a block early and that's fine. 576 * 577 * But when the timer does fire, we check whether or not to refresh it. 578 * Since the tmo granularity is in msecs, it is not too expensive 579 * to refresh the timer, lets say every '8' msecs. 580 * Either the user can set the 'tmo' or we can derive it based on 581 * a) line-speed and b) block-size. 582 * prb_calc_retire_blk_tmo() calculates the tmo. 583 * 584 */ 585 static void prb_retire_rx_blk_timer_expired(unsigned long data) 586 { 587 struct packet_sock *po = (struct packet_sock *)data; 588 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 589 unsigned int frozen; 590 struct tpacket_block_desc *pbd; 591 592 spin_lock(&po->sk.sk_receive_queue.lock); 593 594 frozen = prb_queue_frozen(pkc); 595 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 596 597 if (unlikely(pkc->delete_blk_timer)) 598 goto out; 599 600 /* We only need to plug the race when the block is partially filled. 601 * tpacket_rcv: 602 * lock(); increment BLOCK_NUM_PKTS; unlock() 603 * copy_bits() is in progress ... 604 * timer fires on other cpu: 605 * we can't retire the current block because copy_bits 606 * is in progress. 607 * 608 */ 609 if (BLOCK_NUM_PKTS(pbd)) { 610 while (atomic_read(&pkc->blk_fill_in_prog)) { 611 /* Waiting for skb_copy_bits to finish... */ 612 cpu_relax(); 613 } 614 } 615 616 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 617 if (!frozen) { 618 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 619 if (!prb_dispatch_next_block(pkc, po)) 620 goto refresh_timer; 621 else 622 goto out; 623 } else { 624 /* Case 1. Queue was frozen because user-space was 625 * lagging behind. 626 */ 627 if (prb_curr_blk_in_use(pkc, pbd)) { 628 /* 629 * Ok, user-space is still behind. 630 * So just refresh the timer. 631 */ 632 goto refresh_timer; 633 } else { 634 /* Case 2. queue was frozen,user-space caught up, 635 * now the link went idle && the timer fired. 636 * We don't have a block to close.So we open this 637 * block and restart the timer. 638 * opening a block thaws the queue,restarts timer 639 * Thawing/timer-refresh is a side effect. 640 */ 641 prb_open_block(pkc, pbd); 642 goto out; 643 } 644 } 645 } 646 647 refresh_timer: 648 _prb_refresh_rx_retire_blk_timer(pkc); 649 650 out: 651 spin_unlock(&po->sk.sk_receive_queue.lock); 652 } 653 654 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 655 struct tpacket_block_desc *pbd1, __u32 status) 656 { 657 /* Flush everything minus the block header */ 658 659 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 660 u8 *start, *end; 661 662 start = (u8 *)pbd1; 663 664 /* Skip the block header(we know header WILL fit in 4K) */ 665 start += PAGE_SIZE; 666 667 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 668 for (; start < end; start += PAGE_SIZE) 669 flush_dcache_page(pgv_to_page(start)); 670 671 smp_wmb(); 672 #endif 673 674 /* Now update the block status. */ 675 676 BLOCK_STATUS(pbd1) = status; 677 678 /* Flush the block header */ 679 680 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 681 start = (u8 *)pbd1; 682 flush_dcache_page(pgv_to_page(start)); 683 684 smp_wmb(); 685 #endif 686 } 687 688 /* 689 * Side effect: 690 * 691 * 1) flush the block 692 * 2) Increment active_blk_num 693 * 694 * Note:We DONT refresh the timer on purpose. 695 * Because almost always the next block will be opened. 696 */ 697 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 698 struct tpacket_block_desc *pbd1, 699 struct packet_sock *po, unsigned int stat) 700 { 701 __u32 status = TP_STATUS_USER | stat; 702 703 struct tpacket3_hdr *last_pkt; 704 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 705 706 if (po->stats.stats3.tp_drops) 707 status |= TP_STATUS_LOSING; 708 709 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 710 last_pkt->tp_next_offset = 0; 711 712 /* Get the ts of the last pkt */ 713 if (BLOCK_NUM_PKTS(pbd1)) { 714 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 715 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 716 } else { 717 /* Ok, we tmo'd - so get the current time */ 718 struct timespec ts; 719 getnstimeofday(&ts); 720 h1->ts_last_pkt.ts_sec = ts.tv_sec; 721 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 722 } 723 724 smp_wmb(); 725 726 /* Flush the block */ 727 prb_flush_block(pkc1, pbd1, status); 728 729 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 730 } 731 732 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 733 { 734 pkc->reset_pending_on_curr_blk = 0; 735 } 736 737 /* 738 * Side effect of opening a block: 739 * 740 * 1) prb_queue is thawed. 741 * 2) retire_blk_timer is refreshed. 742 * 743 */ 744 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 745 struct tpacket_block_desc *pbd1) 746 { 747 struct timespec ts; 748 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 749 750 smp_rmb(); 751 752 /* We could have just memset this but we will lose the 753 * flexibility of making the priv area sticky 754 */ 755 756 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 757 BLOCK_NUM_PKTS(pbd1) = 0; 758 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 759 760 getnstimeofday(&ts); 761 762 h1->ts_first_pkt.ts_sec = ts.tv_sec; 763 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 764 765 pkc1->pkblk_start = (char *)pbd1; 766 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 767 768 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 769 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 770 771 pbd1->version = pkc1->version; 772 pkc1->prev = pkc1->nxt_offset; 773 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 774 775 prb_thaw_queue(pkc1); 776 _prb_refresh_rx_retire_blk_timer(pkc1); 777 778 smp_wmb(); 779 } 780 781 /* 782 * Queue freeze logic: 783 * 1) Assume tp_block_nr = 8 blocks. 784 * 2) At time 't0', user opens Rx ring. 785 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 786 * 4) user-space is either sleeping or processing block '0'. 787 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 788 * it will close block-7,loop around and try to fill block '0'. 789 * call-flow: 790 * __packet_lookup_frame_in_block 791 * prb_retire_current_block() 792 * prb_dispatch_next_block() 793 * |->(BLOCK_STATUS == USER) evaluates to true 794 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 795 * 6) Now there are two cases: 796 * 6.1) Link goes idle right after the queue is frozen. 797 * But remember, the last open_block() refreshed the timer. 798 * When this timer expires,it will refresh itself so that we can 799 * re-open block-0 in near future. 800 * 6.2) Link is busy and keeps on receiving packets. This is a simple 801 * case and __packet_lookup_frame_in_block will check if block-0 802 * is free and can now be re-used. 803 */ 804 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 805 struct packet_sock *po) 806 { 807 pkc->reset_pending_on_curr_blk = 1; 808 po->stats.stats3.tp_freeze_q_cnt++; 809 } 810 811 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 812 813 /* 814 * If the next block is free then we will dispatch it 815 * and return a good offset. 816 * Else, we will freeze the queue. 817 * So, caller must check the return value. 818 */ 819 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 820 struct packet_sock *po) 821 { 822 struct tpacket_block_desc *pbd; 823 824 smp_rmb(); 825 826 /* 1. Get current block num */ 827 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 828 829 /* 2. If this block is currently in_use then freeze the queue */ 830 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 831 prb_freeze_queue(pkc, po); 832 return NULL; 833 } 834 835 /* 836 * 3. 837 * open this block and return the offset where the first packet 838 * needs to get stored. 839 */ 840 prb_open_block(pkc, pbd); 841 return (void *)pkc->nxt_offset; 842 } 843 844 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 845 struct packet_sock *po, unsigned int status) 846 { 847 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 848 849 /* retire/close the current block */ 850 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 851 /* 852 * Plug the case where copy_bits() is in progress on 853 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 854 * have space to copy the pkt in the current block and 855 * called prb_retire_current_block() 856 * 857 * We don't need to worry about the TMO case because 858 * the timer-handler already handled this case. 859 */ 860 if (!(status & TP_STATUS_BLK_TMO)) { 861 while (atomic_read(&pkc->blk_fill_in_prog)) { 862 /* Waiting for skb_copy_bits to finish... */ 863 cpu_relax(); 864 } 865 } 866 prb_close_block(pkc, pbd, po, status); 867 return; 868 } 869 } 870 871 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 872 struct tpacket_block_desc *pbd) 873 { 874 return TP_STATUS_USER & BLOCK_STATUS(pbd); 875 } 876 877 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 878 { 879 return pkc->reset_pending_on_curr_blk; 880 } 881 882 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 883 { 884 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 885 atomic_dec(&pkc->blk_fill_in_prog); 886 } 887 888 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 889 struct tpacket3_hdr *ppd) 890 { 891 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 892 } 893 894 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 895 struct tpacket3_hdr *ppd) 896 { 897 ppd->hv1.tp_rxhash = 0; 898 } 899 900 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 901 struct tpacket3_hdr *ppd) 902 { 903 if (vlan_tx_tag_present(pkc->skb)) { 904 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 905 ppd->tp_status = TP_STATUS_VLAN_VALID; 906 } else { 907 ppd->hv1.tp_vlan_tci = 0; 908 ppd->tp_status = TP_STATUS_AVAILABLE; 909 } 910 } 911 912 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 913 struct tpacket3_hdr *ppd) 914 { 915 prb_fill_vlan_info(pkc, ppd); 916 917 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 918 prb_fill_rxhash(pkc, ppd); 919 else 920 prb_clear_rxhash(pkc, ppd); 921 } 922 923 static void prb_fill_curr_block(char *curr, 924 struct tpacket_kbdq_core *pkc, 925 struct tpacket_block_desc *pbd, 926 unsigned int len) 927 { 928 struct tpacket3_hdr *ppd; 929 930 ppd = (struct tpacket3_hdr *)curr; 931 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 932 pkc->prev = curr; 933 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 934 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 935 BLOCK_NUM_PKTS(pbd) += 1; 936 atomic_inc(&pkc->blk_fill_in_prog); 937 prb_run_all_ft_ops(pkc, ppd); 938 } 939 940 /* Assumes caller has the sk->rx_queue.lock */ 941 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 942 struct sk_buff *skb, 943 int status, 944 unsigned int len 945 ) 946 { 947 struct tpacket_kbdq_core *pkc; 948 struct tpacket_block_desc *pbd; 949 char *curr, *end; 950 951 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 952 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 953 954 /* Queue is frozen when user space is lagging behind */ 955 if (prb_queue_frozen(pkc)) { 956 /* 957 * Check if that last block which caused the queue to freeze, 958 * is still in_use by user-space. 959 */ 960 if (prb_curr_blk_in_use(pkc, pbd)) { 961 /* Can't record this packet */ 962 return NULL; 963 } else { 964 /* 965 * Ok, the block was released by user-space. 966 * Now let's open that block. 967 * opening a block also thaws the queue. 968 * Thawing is a side effect. 969 */ 970 prb_open_block(pkc, pbd); 971 } 972 } 973 974 smp_mb(); 975 curr = pkc->nxt_offset; 976 pkc->skb = skb; 977 end = (char *)pbd + pkc->kblk_size; 978 979 /* first try the current block */ 980 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 981 prb_fill_curr_block(curr, pkc, pbd, len); 982 return (void *)curr; 983 } 984 985 /* Ok, close the current block */ 986 prb_retire_current_block(pkc, po, 0); 987 988 /* Now, try to dispatch the next block */ 989 curr = (char *)prb_dispatch_next_block(pkc, po); 990 if (curr) { 991 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 992 prb_fill_curr_block(curr, pkc, pbd, len); 993 return (void *)curr; 994 } 995 996 /* 997 * No free blocks are available.user_space hasn't caught up yet. 998 * Queue was just frozen and now this packet will get dropped. 999 */ 1000 return NULL; 1001 } 1002 1003 static void *packet_current_rx_frame(struct packet_sock *po, 1004 struct sk_buff *skb, 1005 int status, unsigned int len) 1006 { 1007 char *curr = NULL; 1008 switch (po->tp_version) { 1009 case TPACKET_V1: 1010 case TPACKET_V2: 1011 curr = packet_lookup_frame(po, &po->rx_ring, 1012 po->rx_ring.head, status); 1013 return curr; 1014 case TPACKET_V3: 1015 return __packet_lookup_frame_in_block(po, skb, status, len); 1016 default: 1017 WARN(1, "TPACKET version not supported\n"); 1018 BUG(); 1019 return NULL; 1020 } 1021 } 1022 1023 static void *prb_lookup_block(struct packet_sock *po, 1024 struct packet_ring_buffer *rb, 1025 unsigned int idx, 1026 int status) 1027 { 1028 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1029 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1030 1031 if (status != BLOCK_STATUS(pbd)) 1032 return NULL; 1033 return pbd; 1034 } 1035 1036 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1037 { 1038 unsigned int prev; 1039 if (rb->prb_bdqc.kactive_blk_num) 1040 prev = rb->prb_bdqc.kactive_blk_num-1; 1041 else 1042 prev = rb->prb_bdqc.knum_blocks-1; 1043 return prev; 1044 } 1045 1046 /* Assumes caller has held the rx_queue.lock */ 1047 static void *__prb_previous_block(struct packet_sock *po, 1048 struct packet_ring_buffer *rb, 1049 int status) 1050 { 1051 unsigned int previous = prb_previous_blk_num(rb); 1052 return prb_lookup_block(po, rb, previous, status); 1053 } 1054 1055 static void *packet_previous_rx_frame(struct packet_sock *po, 1056 struct packet_ring_buffer *rb, 1057 int status) 1058 { 1059 if (po->tp_version <= TPACKET_V2) 1060 return packet_previous_frame(po, rb, status); 1061 1062 return __prb_previous_block(po, rb, status); 1063 } 1064 1065 static void packet_increment_rx_head(struct packet_sock *po, 1066 struct packet_ring_buffer *rb) 1067 { 1068 switch (po->tp_version) { 1069 case TPACKET_V1: 1070 case TPACKET_V2: 1071 return packet_increment_head(rb); 1072 case TPACKET_V3: 1073 default: 1074 WARN(1, "TPACKET version not supported.\n"); 1075 BUG(); 1076 return; 1077 } 1078 } 1079 1080 static void *packet_previous_frame(struct packet_sock *po, 1081 struct packet_ring_buffer *rb, 1082 int status) 1083 { 1084 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1085 return packet_lookup_frame(po, rb, previous, status); 1086 } 1087 1088 static void packet_increment_head(struct packet_ring_buffer *buff) 1089 { 1090 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1091 } 1092 1093 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1094 { 1095 struct sock *sk = &po->sk; 1096 bool has_room; 1097 1098 if (po->prot_hook.func != tpacket_rcv) 1099 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize) 1100 <= sk->sk_rcvbuf; 1101 1102 spin_lock(&sk->sk_receive_queue.lock); 1103 if (po->tp_version == TPACKET_V3) 1104 has_room = prb_lookup_block(po, &po->rx_ring, 1105 po->rx_ring.prb_bdqc.kactive_blk_num, 1106 TP_STATUS_KERNEL); 1107 else 1108 has_room = packet_lookup_frame(po, &po->rx_ring, 1109 po->rx_ring.head, 1110 TP_STATUS_KERNEL); 1111 spin_unlock(&sk->sk_receive_queue.lock); 1112 1113 return has_room; 1114 } 1115 1116 static void packet_sock_destruct(struct sock *sk) 1117 { 1118 skb_queue_purge(&sk->sk_error_queue); 1119 1120 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1121 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1122 1123 if (!sock_flag(sk, SOCK_DEAD)) { 1124 pr_err("Attempt to release alive packet socket: %p\n", sk); 1125 return; 1126 } 1127 1128 sk_refcnt_debug_dec(sk); 1129 } 1130 1131 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1132 { 1133 int x = atomic_read(&f->rr_cur) + 1; 1134 1135 if (x >= num) 1136 x = 0; 1137 1138 return x; 1139 } 1140 1141 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1142 struct sk_buff *skb, 1143 unsigned int num) 1144 { 1145 return reciprocal_divide(skb->rxhash, num); 1146 } 1147 1148 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1149 struct sk_buff *skb, 1150 unsigned int num) 1151 { 1152 int cur, old; 1153 1154 cur = atomic_read(&f->rr_cur); 1155 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1156 fanout_rr_next(f, num))) != cur) 1157 cur = old; 1158 return cur; 1159 } 1160 1161 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1162 struct sk_buff *skb, 1163 unsigned int num) 1164 { 1165 return smp_processor_id() % num; 1166 } 1167 1168 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1169 struct sk_buff *skb, 1170 unsigned int num) 1171 { 1172 return reciprocal_divide(prandom_u32(), num); 1173 } 1174 1175 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1176 struct sk_buff *skb, 1177 unsigned int idx, unsigned int skip, 1178 unsigned int num) 1179 { 1180 unsigned int i, j; 1181 1182 i = j = min_t(int, f->next[idx], num - 1); 1183 do { 1184 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) { 1185 if (i != j) 1186 f->next[idx] = i; 1187 return i; 1188 } 1189 if (++i == num) 1190 i = 0; 1191 } while (i != j); 1192 1193 return idx; 1194 } 1195 1196 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1197 { 1198 return f->flags & (flag >> 8); 1199 } 1200 1201 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1202 struct packet_type *pt, struct net_device *orig_dev) 1203 { 1204 struct packet_fanout *f = pt->af_packet_priv; 1205 unsigned int num = f->num_members; 1206 struct packet_sock *po; 1207 unsigned int idx; 1208 1209 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1210 !num) { 1211 kfree_skb(skb); 1212 return 0; 1213 } 1214 1215 switch (f->type) { 1216 case PACKET_FANOUT_HASH: 1217 default: 1218 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1219 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1220 if (!skb) 1221 return 0; 1222 } 1223 skb_get_rxhash(skb); 1224 idx = fanout_demux_hash(f, skb, num); 1225 break; 1226 case PACKET_FANOUT_LB: 1227 idx = fanout_demux_lb(f, skb, num); 1228 break; 1229 case PACKET_FANOUT_CPU: 1230 idx = fanout_demux_cpu(f, skb, num); 1231 break; 1232 case PACKET_FANOUT_RND: 1233 idx = fanout_demux_rnd(f, skb, num); 1234 break; 1235 case PACKET_FANOUT_ROLLOVER: 1236 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num); 1237 break; 1238 } 1239 1240 po = pkt_sk(f->arr[idx]); 1241 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) && 1242 unlikely(!packet_rcv_has_room(po, skb))) { 1243 idx = fanout_demux_rollover(f, skb, idx, idx, num); 1244 po = pkt_sk(f->arr[idx]); 1245 } 1246 1247 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1248 } 1249 1250 DEFINE_MUTEX(fanout_mutex); 1251 EXPORT_SYMBOL_GPL(fanout_mutex); 1252 static LIST_HEAD(fanout_list); 1253 1254 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1255 { 1256 struct packet_fanout *f = po->fanout; 1257 1258 spin_lock(&f->lock); 1259 f->arr[f->num_members] = sk; 1260 smp_wmb(); 1261 f->num_members++; 1262 spin_unlock(&f->lock); 1263 } 1264 1265 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1266 { 1267 struct packet_fanout *f = po->fanout; 1268 int i; 1269 1270 spin_lock(&f->lock); 1271 for (i = 0; i < f->num_members; i++) { 1272 if (f->arr[i] == sk) 1273 break; 1274 } 1275 BUG_ON(i >= f->num_members); 1276 f->arr[i] = f->arr[f->num_members - 1]; 1277 f->num_members--; 1278 spin_unlock(&f->lock); 1279 } 1280 1281 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk) 1282 { 1283 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) 1284 return true; 1285 1286 return false; 1287 } 1288 1289 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1290 { 1291 struct packet_sock *po = pkt_sk(sk); 1292 struct packet_fanout *f, *match; 1293 u8 type = type_flags & 0xff; 1294 u8 flags = type_flags >> 8; 1295 int err; 1296 1297 switch (type) { 1298 case PACKET_FANOUT_ROLLOVER: 1299 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1300 return -EINVAL; 1301 case PACKET_FANOUT_HASH: 1302 case PACKET_FANOUT_LB: 1303 case PACKET_FANOUT_CPU: 1304 case PACKET_FANOUT_RND: 1305 break; 1306 default: 1307 return -EINVAL; 1308 } 1309 1310 if (!po->running) 1311 return -EINVAL; 1312 1313 if (po->fanout) 1314 return -EALREADY; 1315 1316 mutex_lock(&fanout_mutex); 1317 match = NULL; 1318 list_for_each_entry(f, &fanout_list, list) { 1319 if (f->id == id && 1320 read_pnet(&f->net) == sock_net(sk)) { 1321 match = f; 1322 break; 1323 } 1324 } 1325 err = -EINVAL; 1326 if (match && match->flags != flags) 1327 goto out; 1328 if (!match) { 1329 err = -ENOMEM; 1330 match = kzalloc(sizeof(*match), GFP_KERNEL); 1331 if (!match) 1332 goto out; 1333 write_pnet(&match->net, sock_net(sk)); 1334 match->id = id; 1335 match->type = type; 1336 match->flags = flags; 1337 atomic_set(&match->rr_cur, 0); 1338 INIT_LIST_HEAD(&match->list); 1339 spin_lock_init(&match->lock); 1340 atomic_set(&match->sk_ref, 0); 1341 match->prot_hook.type = po->prot_hook.type; 1342 match->prot_hook.dev = po->prot_hook.dev; 1343 match->prot_hook.func = packet_rcv_fanout; 1344 match->prot_hook.af_packet_priv = match; 1345 match->prot_hook.id_match = match_fanout_group; 1346 dev_add_pack(&match->prot_hook); 1347 list_add(&match->list, &fanout_list); 1348 } 1349 err = -EINVAL; 1350 if (match->type == type && 1351 match->prot_hook.type == po->prot_hook.type && 1352 match->prot_hook.dev == po->prot_hook.dev) { 1353 err = -ENOSPC; 1354 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1355 __dev_remove_pack(&po->prot_hook); 1356 po->fanout = match; 1357 atomic_inc(&match->sk_ref); 1358 __fanout_link(sk, po); 1359 err = 0; 1360 } 1361 } 1362 out: 1363 mutex_unlock(&fanout_mutex); 1364 return err; 1365 } 1366 1367 static void fanout_release(struct sock *sk) 1368 { 1369 struct packet_sock *po = pkt_sk(sk); 1370 struct packet_fanout *f; 1371 1372 f = po->fanout; 1373 if (!f) 1374 return; 1375 1376 mutex_lock(&fanout_mutex); 1377 po->fanout = NULL; 1378 1379 if (atomic_dec_and_test(&f->sk_ref)) { 1380 list_del(&f->list); 1381 dev_remove_pack(&f->prot_hook); 1382 kfree(f); 1383 } 1384 mutex_unlock(&fanout_mutex); 1385 } 1386 1387 static const struct proto_ops packet_ops; 1388 1389 static const struct proto_ops packet_ops_spkt; 1390 1391 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1392 struct packet_type *pt, struct net_device *orig_dev) 1393 { 1394 struct sock *sk; 1395 struct sockaddr_pkt *spkt; 1396 1397 /* 1398 * When we registered the protocol we saved the socket in the data 1399 * field for just this event. 1400 */ 1401 1402 sk = pt->af_packet_priv; 1403 1404 /* 1405 * Yank back the headers [hope the device set this 1406 * right or kerboom...] 1407 * 1408 * Incoming packets have ll header pulled, 1409 * push it back. 1410 * 1411 * For outgoing ones skb->data == skb_mac_header(skb) 1412 * so that this procedure is noop. 1413 */ 1414 1415 if (skb->pkt_type == PACKET_LOOPBACK) 1416 goto out; 1417 1418 if (!net_eq(dev_net(dev), sock_net(sk))) 1419 goto out; 1420 1421 skb = skb_share_check(skb, GFP_ATOMIC); 1422 if (skb == NULL) 1423 goto oom; 1424 1425 /* drop any routing info */ 1426 skb_dst_drop(skb); 1427 1428 /* drop conntrack reference */ 1429 nf_reset(skb); 1430 1431 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1432 1433 skb_push(skb, skb->data - skb_mac_header(skb)); 1434 1435 /* 1436 * The SOCK_PACKET socket receives _all_ frames. 1437 */ 1438 1439 spkt->spkt_family = dev->type; 1440 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1441 spkt->spkt_protocol = skb->protocol; 1442 1443 /* 1444 * Charge the memory to the socket. This is done specifically 1445 * to prevent sockets using all the memory up. 1446 */ 1447 1448 if (sock_queue_rcv_skb(sk, skb) == 0) 1449 return 0; 1450 1451 out: 1452 kfree_skb(skb); 1453 oom: 1454 return 0; 1455 } 1456 1457 1458 /* 1459 * Output a raw packet to a device layer. This bypasses all the other 1460 * protocol layers and you must therefore supply it with a complete frame 1461 */ 1462 1463 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1464 struct msghdr *msg, size_t len) 1465 { 1466 struct sock *sk = sock->sk; 1467 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1468 struct sk_buff *skb = NULL; 1469 struct net_device *dev; 1470 __be16 proto = 0; 1471 int err; 1472 int extra_len = 0; 1473 1474 /* 1475 * Get and verify the address. 1476 */ 1477 1478 if (saddr) { 1479 if (msg->msg_namelen < sizeof(struct sockaddr)) 1480 return -EINVAL; 1481 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1482 proto = saddr->spkt_protocol; 1483 } else 1484 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1485 1486 /* 1487 * Find the device first to size check it 1488 */ 1489 1490 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1491 retry: 1492 rcu_read_lock(); 1493 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1494 err = -ENODEV; 1495 if (dev == NULL) 1496 goto out_unlock; 1497 1498 err = -ENETDOWN; 1499 if (!(dev->flags & IFF_UP)) 1500 goto out_unlock; 1501 1502 /* 1503 * You may not queue a frame bigger than the mtu. This is the lowest level 1504 * raw protocol and you must do your own fragmentation at this level. 1505 */ 1506 1507 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1508 if (!netif_supports_nofcs(dev)) { 1509 err = -EPROTONOSUPPORT; 1510 goto out_unlock; 1511 } 1512 extra_len = 4; /* We're doing our own CRC */ 1513 } 1514 1515 err = -EMSGSIZE; 1516 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1517 goto out_unlock; 1518 1519 if (!skb) { 1520 size_t reserved = LL_RESERVED_SPACE(dev); 1521 int tlen = dev->needed_tailroom; 1522 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1523 1524 rcu_read_unlock(); 1525 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1526 if (skb == NULL) 1527 return -ENOBUFS; 1528 /* FIXME: Save some space for broken drivers that write a hard 1529 * header at transmission time by themselves. PPP is the notable 1530 * one here. This should really be fixed at the driver level. 1531 */ 1532 skb_reserve(skb, reserved); 1533 skb_reset_network_header(skb); 1534 1535 /* Try to align data part correctly */ 1536 if (hhlen) { 1537 skb->data -= hhlen; 1538 skb->tail -= hhlen; 1539 if (len < hhlen) 1540 skb_reset_network_header(skb); 1541 } 1542 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1543 if (err) 1544 goto out_free; 1545 goto retry; 1546 } 1547 1548 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1549 /* Earlier code assumed this would be a VLAN pkt, 1550 * double-check this now that we have the actual 1551 * packet in hand. 1552 */ 1553 struct ethhdr *ehdr; 1554 skb_reset_mac_header(skb); 1555 ehdr = eth_hdr(skb); 1556 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1557 err = -EMSGSIZE; 1558 goto out_unlock; 1559 } 1560 } 1561 1562 skb->protocol = proto; 1563 skb->dev = dev; 1564 skb->priority = sk->sk_priority; 1565 skb->mark = sk->sk_mark; 1566 1567 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1568 1569 if (unlikely(extra_len == 4)) 1570 skb->no_fcs = 1; 1571 1572 skb_probe_transport_header(skb, 0); 1573 1574 dev_queue_xmit(skb); 1575 rcu_read_unlock(); 1576 return len; 1577 1578 out_unlock: 1579 rcu_read_unlock(); 1580 out_free: 1581 kfree_skb(skb); 1582 return err; 1583 } 1584 1585 static unsigned int run_filter(const struct sk_buff *skb, 1586 const struct sock *sk, 1587 unsigned int res) 1588 { 1589 struct sk_filter *filter; 1590 1591 rcu_read_lock(); 1592 filter = rcu_dereference(sk->sk_filter); 1593 if (filter != NULL) 1594 res = SK_RUN_FILTER(filter, skb); 1595 rcu_read_unlock(); 1596 1597 return res; 1598 } 1599 1600 /* 1601 * This function makes lazy skb cloning in hope that most of packets 1602 * are discarded by BPF. 1603 * 1604 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1605 * and skb->cb are mangled. It works because (and until) packets 1606 * falling here are owned by current CPU. Output packets are cloned 1607 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1608 * sequencially, so that if we return skb to original state on exit, 1609 * we will not harm anyone. 1610 */ 1611 1612 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1613 struct packet_type *pt, struct net_device *orig_dev) 1614 { 1615 struct sock *sk; 1616 struct sockaddr_ll *sll; 1617 struct packet_sock *po; 1618 u8 *skb_head = skb->data; 1619 int skb_len = skb->len; 1620 unsigned int snaplen, res; 1621 1622 if (skb->pkt_type == PACKET_LOOPBACK) 1623 goto drop; 1624 1625 sk = pt->af_packet_priv; 1626 po = pkt_sk(sk); 1627 1628 if (!net_eq(dev_net(dev), sock_net(sk))) 1629 goto drop; 1630 1631 skb->dev = dev; 1632 1633 if (dev->header_ops) { 1634 /* The device has an explicit notion of ll header, 1635 * exported to higher levels. 1636 * 1637 * Otherwise, the device hides details of its frame 1638 * structure, so that corresponding packet head is 1639 * never delivered to user. 1640 */ 1641 if (sk->sk_type != SOCK_DGRAM) 1642 skb_push(skb, skb->data - skb_mac_header(skb)); 1643 else if (skb->pkt_type == PACKET_OUTGOING) { 1644 /* Special case: outgoing packets have ll header at head */ 1645 skb_pull(skb, skb_network_offset(skb)); 1646 } 1647 } 1648 1649 snaplen = skb->len; 1650 1651 res = run_filter(skb, sk, snaplen); 1652 if (!res) 1653 goto drop_n_restore; 1654 if (snaplen > res) 1655 snaplen = res; 1656 1657 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1658 goto drop_n_acct; 1659 1660 if (skb_shared(skb)) { 1661 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1662 if (nskb == NULL) 1663 goto drop_n_acct; 1664 1665 if (skb_head != skb->data) { 1666 skb->data = skb_head; 1667 skb->len = skb_len; 1668 } 1669 consume_skb(skb); 1670 skb = nskb; 1671 } 1672 1673 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1674 sizeof(skb->cb)); 1675 1676 sll = &PACKET_SKB_CB(skb)->sa.ll; 1677 sll->sll_family = AF_PACKET; 1678 sll->sll_hatype = dev->type; 1679 sll->sll_protocol = skb->protocol; 1680 sll->sll_pkttype = skb->pkt_type; 1681 if (unlikely(po->origdev)) 1682 sll->sll_ifindex = orig_dev->ifindex; 1683 else 1684 sll->sll_ifindex = dev->ifindex; 1685 1686 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1687 1688 PACKET_SKB_CB(skb)->origlen = skb->len; 1689 1690 if (pskb_trim(skb, snaplen)) 1691 goto drop_n_acct; 1692 1693 skb_set_owner_r(skb, sk); 1694 skb->dev = NULL; 1695 skb_dst_drop(skb); 1696 1697 /* drop conntrack reference */ 1698 nf_reset(skb); 1699 1700 spin_lock(&sk->sk_receive_queue.lock); 1701 po->stats.stats1.tp_packets++; 1702 skb->dropcount = atomic_read(&sk->sk_drops); 1703 __skb_queue_tail(&sk->sk_receive_queue, skb); 1704 spin_unlock(&sk->sk_receive_queue.lock); 1705 sk->sk_data_ready(sk, skb->len); 1706 return 0; 1707 1708 drop_n_acct: 1709 spin_lock(&sk->sk_receive_queue.lock); 1710 po->stats.stats1.tp_drops++; 1711 atomic_inc(&sk->sk_drops); 1712 spin_unlock(&sk->sk_receive_queue.lock); 1713 1714 drop_n_restore: 1715 if (skb_head != skb->data && skb_shared(skb)) { 1716 skb->data = skb_head; 1717 skb->len = skb_len; 1718 } 1719 drop: 1720 consume_skb(skb); 1721 return 0; 1722 } 1723 1724 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1725 struct packet_type *pt, struct net_device *orig_dev) 1726 { 1727 struct sock *sk; 1728 struct packet_sock *po; 1729 struct sockaddr_ll *sll; 1730 union tpacket_uhdr h; 1731 u8 *skb_head = skb->data; 1732 int skb_len = skb->len; 1733 unsigned int snaplen, res; 1734 unsigned long status = TP_STATUS_USER; 1735 unsigned short macoff, netoff, hdrlen; 1736 struct sk_buff *copy_skb = NULL; 1737 struct timespec ts; 1738 __u32 ts_status; 1739 1740 if (skb->pkt_type == PACKET_LOOPBACK) 1741 goto drop; 1742 1743 sk = pt->af_packet_priv; 1744 po = pkt_sk(sk); 1745 1746 if (!net_eq(dev_net(dev), sock_net(sk))) 1747 goto drop; 1748 1749 if (dev->header_ops) { 1750 if (sk->sk_type != SOCK_DGRAM) 1751 skb_push(skb, skb->data - skb_mac_header(skb)); 1752 else if (skb->pkt_type == PACKET_OUTGOING) { 1753 /* Special case: outgoing packets have ll header at head */ 1754 skb_pull(skb, skb_network_offset(skb)); 1755 } 1756 } 1757 1758 if (skb->ip_summed == CHECKSUM_PARTIAL) 1759 status |= TP_STATUS_CSUMNOTREADY; 1760 1761 snaplen = skb->len; 1762 1763 res = run_filter(skb, sk, snaplen); 1764 if (!res) 1765 goto drop_n_restore; 1766 if (snaplen > res) 1767 snaplen = res; 1768 1769 if (sk->sk_type == SOCK_DGRAM) { 1770 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1771 po->tp_reserve; 1772 } else { 1773 unsigned int maclen = skb_network_offset(skb); 1774 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1775 (maclen < 16 ? 16 : maclen)) + 1776 po->tp_reserve; 1777 macoff = netoff - maclen; 1778 } 1779 if (po->tp_version <= TPACKET_V2) { 1780 if (macoff + snaplen > po->rx_ring.frame_size) { 1781 if (po->copy_thresh && 1782 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1783 if (skb_shared(skb)) { 1784 copy_skb = skb_clone(skb, GFP_ATOMIC); 1785 } else { 1786 copy_skb = skb_get(skb); 1787 skb_head = skb->data; 1788 } 1789 if (copy_skb) 1790 skb_set_owner_r(copy_skb, sk); 1791 } 1792 snaplen = po->rx_ring.frame_size - macoff; 1793 if ((int)snaplen < 0) 1794 snaplen = 0; 1795 } 1796 } 1797 spin_lock(&sk->sk_receive_queue.lock); 1798 h.raw = packet_current_rx_frame(po, skb, 1799 TP_STATUS_KERNEL, (macoff+snaplen)); 1800 if (!h.raw) 1801 goto ring_is_full; 1802 if (po->tp_version <= TPACKET_V2) { 1803 packet_increment_rx_head(po, &po->rx_ring); 1804 /* 1805 * LOSING will be reported till you read the stats, 1806 * because it's COR - Clear On Read. 1807 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1808 * at packet level. 1809 */ 1810 if (po->stats.stats1.tp_drops) 1811 status |= TP_STATUS_LOSING; 1812 } 1813 po->stats.stats1.tp_packets++; 1814 if (copy_skb) { 1815 status |= TP_STATUS_COPY; 1816 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1817 } 1818 spin_unlock(&sk->sk_receive_queue.lock); 1819 1820 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1821 1822 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 1823 getnstimeofday(&ts); 1824 1825 status |= ts_status; 1826 1827 switch (po->tp_version) { 1828 case TPACKET_V1: 1829 h.h1->tp_len = skb->len; 1830 h.h1->tp_snaplen = snaplen; 1831 h.h1->tp_mac = macoff; 1832 h.h1->tp_net = netoff; 1833 h.h1->tp_sec = ts.tv_sec; 1834 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 1835 hdrlen = sizeof(*h.h1); 1836 break; 1837 case TPACKET_V2: 1838 h.h2->tp_len = skb->len; 1839 h.h2->tp_snaplen = snaplen; 1840 h.h2->tp_mac = macoff; 1841 h.h2->tp_net = netoff; 1842 h.h2->tp_sec = ts.tv_sec; 1843 h.h2->tp_nsec = ts.tv_nsec; 1844 if (vlan_tx_tag_present(skb)) { 1845 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1846 status |= TP_STATUS_VLAN_VALID; 1847 } else { 1848 h.h2->tp_vlan_tci = 0; 1849 } 1850 h.h2->tp_padding = 0; 1851 hdrlen = sizeof(*h.h2); 1852 break; 1853 case TPACKET_V3: 1854 /* tp_nxt_offset,vlan are already populated above. 1855 * So DONT clear those fields here 1856 */ 1857 h.h3->tp_status |= status; 1858 h.h3->tp_len = skb->len; 1859 h.h3->tp_snaplen = snaplen; 1860 h.h3->tp_mac = macoff; 1861 h.h3->tp_net = netoff; 1862 h.h3->tp_sec = ts.tv_sec; 1863 h.h3->tp_nsec = ts.tv_nsec; 1864 hdrlen = sizeof(*h.h3); 1865 break; 1866 default: 1867 BUG(); 1868 } 1869 1870 sll = h.raw + TPACKET_ALIGN(hdrlen); 1871 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1872 sll->sll_family = AF_PACKET; 1873 sll->sll_hatype = dev->type; 1874 sll->sll_protocol = skb->protocol; 1875 sll->sll_pkttype = skb->pkt_type; 1876 if (unlikely(po->origdev)) 1877 sll->sll_ifindex = orig_dev->ifindex; 1878 else 1879 sll->sll_ifindex = dev->ifindex; 1880 1881 smp_mb(); 1882 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1883 { 1884 u8 *start, *end; 1885 1886 if (po->tp_version <= TPACKET_V2) { 1887 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1888 + macoff + snaplen); 1889 for (start = h.raw; start < end; start += PAGE_SIZE) 1890 flush_dcache_page(pgv_to_page(start)); 1891 } 1892 smp_wmb(); 1893 } 1894 #endif 1895 if (po->tp_version <= TPACKET_V2) 1896 __packet_set_status(po, h.raw, status); 1897 else 1898 prb_clear_blk_fill_status(&po->rx_ring); 1899 1900 sk->sk_data_ready(sk, 0); 1901 1902 drop_n_restore: 1903 if (skb_head != skb->data && skb_shared(skb)) { 1904 skb->data = skb_head; 1905 skb->len = skb_len; 1906 } 1907 drop: 1908 kfree_skb(skb); 1909 return 0; 1910 1911 ring_is_full: 1912 po->stats.stats1.tp_drops++; 1913 spin_unlock(&sk->sk_receive_queue.lock); 1914 1915 sk->sk_data_ready(sk, 0); 1916 kfree_skb(copy_skb); 1917 goto drop_n_restore; 1918 } 1919 1920 static void tpacket_destruct_skb(struct sk_buff *skb) 1921 { 1922 struct packet_sock *po = pkt_sk(skb->sk); 1923 void *ph; 1924 1925 if (likely(po->tx_ring.pg_vec)) { 1926 __u32 ts; 1927 1928 ph = skb_shinfo(skb)->destructor_arg; 1929 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1930 atomic_dec(&po->tx_ring.pending); 1931 1932 ts = __packet_set_timestamp(po, ph, skb); 1933 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 1934 } 1935 1936 sock_wfree(skb); 1937 } 1938 1939 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1940 void *frame, struct net_device *dev, int size_max, 1941 __be16 proto, unsigned char *addr, int hlen) 1942 { 1943 union tpacket_uhdr ph; 1944 int to_write, offset, len, tp_len, nr_frags, len_max; 1945 struct socket *sock = po->sk.sk_socket; 1946 struct page *page; 1947 void *data; 1948 int err; 1949 1950 ph.raw = frame; 1951 1952 skb->protocol = proto; 1953 skb->dev = dev; 1954 skb->priority = po->sk.sk_priority; 1955 skb->mark = po->sk.sk_mark; 1956 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 1957 skb_shinfo(skb)->destructor_arg = ph.raw; 1958 1959 switch (po->tp_version) { 1960 case TPACKET_V2: 1961 tp_len = ph.h2->tp_len; 1962 break; 1963 default: 1964 tp_len = ph.h1->tp_len; 1965 break; 1966 } 1967 if (unlikely(tp_len > size_max)) { 1968 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1969 return -EMSGSIZE; 1970 } 1971 1972 skb_reserve(skb, hlen); 1973 skb_reset_network_header(skb); 1974 skb_probe_transport_header(skb, 0); 1975 1976 if (po->tp_tx_has_off) { 1977 int off_min, off_max, off; 1978 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 1979 off_max = po->tx_ring.frame_size - tp_len; 1980 if (sock->type == SOCK_DGRAM) { 1981 switch (po->tp_version) { 1982 case TPACKET_V2: 1983 off = ph.h2->tp_net; 1984 break; 1985 default: 1986 off = ph.h1->tp_net; 1987 break; 1988 } 1989 } else { 1990 switch (po->tp_version) { 1991 case TPACKET_V2: 1992 off = ph.h2->tp_mac; 1993 break; 1994 default: 1995 off = ph.h1->tp_mac; 1996 break; 1997 } 1998 } 1999 if (unlikely((off < off_min) || (off_max < off))) 2000 return -EINVAL; 2001 data = ph.raw + off; 2002 } else { 2003 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 2004 } 2005 to_write = tp_len; 2006 2007 if (sock->type == SOCK_DGRAM) { 2008 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2009 NULL, tp_len); 2010 if (unlikely(err < 0)) 2011 return -EINVAL; 2012 } else if (dev->hard_header_len) { 2013 /* net device doesn't like empty head */ 2014 if (unlikely(tp_len <= dev->hard_header_len)) { 2015 pr_err("packet size is too short (%d < %d)\n", 2016 tp_len, dev->hard_header_len); 2017 return -EINVAL; 2018 } 2019 2020 skb_push(skb, dev->hard_header_len); 2021 err = skb_store_bits(skb, 0, data, 2022 dev->hard_header_len); 2023 if (unlikely(err)) 2024 return err; 2025 2026 data += dev->hard_header_len; 2027 to_write -= dev->hard_header_len; 2028 } 2029 2030 offset = offset_in_page(data); 2031 len_max = PAGE_SIZE - offset; 2032 len = ((to_write > len_max) ? len_max : to_write); 2033 2034 skb->data_len = to_write; 2035 skb->len += to_write; 2036 skb->truesize += to_write; 2037 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2038 2039 while (likely(to_write)) { 2040 nr_frags = skb_shinfo(skb)->nr_frags; 2041 2042 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2043 pr_err("Packet exceed the number of skb frags(%lu)\n", 2044 MAX_SKB_FRAGS); 2045 return -EFAULT; 2046 } 2047 2048 page = pgv_to_page(data); 2049 data += len; 2050 flush_dcache_page(page); 2051 get_page(page); 2052 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2053 to_write -= len; 2054 offset = 0; 2055 len_max = PAGE_SIZE; 2056 len = ((to_write > len_max) ? len_max : to_write); 2057 } 2058 2059 return tp_len; 2060 } 2061 2062 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 2063 { 2064 struct net_device *dev; 2065 2066 rcu_read_lock(); 2067 dev = rcu_dereference(po->cached_dev); 2068 if (dev) 2069 dev_hold(dev); 2070 rcu_read_unlock(); 2071 2072 return dev; 2073 } 2074 2075 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2076 { 2077 struct sk_buff *skb; 2078 struct net_device *dev; 2079 __be16 proto; 2080 int err, reserve = 0; 2081 void *ph; 2082 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2083 int tp_len, size_max; 2084 unsigned char *addr; 2085 int len_sum = 0; 2086 int status = TP_STATUS_AVAILABLE; 2087 int hlen, tlen; 2088 2089 mutex_lock(&po->pg_vec_lock); 2090 2091 if (saddr == NULL) { 2092 dev = packet_cached_dev_get(po); 2093 proto = po->num; 2094 addr = NULL; 2095 } else { 2096 err = -EINVAL; 2097 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2098 goto out; 2099 if (msg->msg_namelen < (saddr->sll_halen 2100 + offsetof(struct sockaddr_ll, 2101 sll_addr))) 2102 goto out; 2103 proto = saddr->sll_protocol; 2104 addr = saddr->sll_addr; 2105 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2106 } 2107 2108 err = -ENXIO; 2109 if (unlikely(dev == NULL)) 2110 goto out; 2111 err = -ENETDOWN; 2112 if (unlikely(!(dev->flags & IFF_UP))) 2113 goto out_put; 2114 2115 reserve = dev->hard_header_len; 2116 2117 size_max = po->tx_ring.frame_size 2118 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2119 2120 if (size_max > dev->mtu + reserve) 2121 size_max = dev->mtu + reserve; 2122 2123 do { 2124 ph = packet_current_frame(po, &po->tx_ring, 2125 TP_STATUS_SEND_REQUEST); 2126 2127 if (unlikely(ph == NULL)) { 2128 schedule(); 2129 continue; 2130 } 2131 2132 status = TP_STATUS_SEND_REQUEST; 2133 hlen = LL_RESERVED_SPACE(dev); 2134 tlen = dev->needed_tailroom; 2135 skb = sock_alloc_send_skb(&po->sk, 2136 hlen + tlen + sizeof(struct sockaddr_ll), 2137 0, &err); 2138 2139 if (unlikely(skb == NULL)) 2140 goto out_status; 2141 2142 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2143 addr, hlen); 2144 2145 if (unlikely(tp_len < 0)) { 2146 if (po->tp_loss) { 2147 __packet_set_status(po, ph, 2148 TP_STATUS_AVAILABLE); 2149 packet_increment_head(&po->tx_ring); 2150 kfree_skb(skb); 2151 continue; 2152 } else { 2153 status = TP_STATUS_WRONG_FORMAT; 2154 err = tp_len; 2155 goto out_status; 2156 } 2157 } 2158 2159 skb->destructor = tpacket_destruct_skb; 2160 __packet_set_status(po, ph, TP_STATUS_SENDING); 2161 atomic_inc(&po->tx_ring.pending); 2162 2163 status = TP_STATUS_SEND_REQUEST; 2164 err = dev_queue_xmit(skb); 2165 if (unlikely(err > 0)) { 2166 err = net_xmit_errno(err); 2167 if (err && __packet_get_status(po, ph) == 2168 TP_STATUS_AVAILABLE) { 2169 /* skb was destructed already */ 2170 skb = NULL; 2171 goto out_status; 2172 } 2173 /* 2174 * skb was dropped but not destructed yet; 2175 * let's treat it like congestion or err < 0 2176 */ 2177 err = 0; 2178 } 2179 packet_increment_head(&po->tx_ring); 2180 len_sum += tp_len; 2181 } while (likely((ph != NULL) || 2182 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2183 (atomic_read(&po->tx_ring.pending)))) 2184 ); 2185 2186 err = len_sum; 2187 goto out_put; 2188 2189 out_status: 2190 __packet_set_status(po, ph, status); 2191 kfree_skb(skb); 2192 out_put: 2193 dev_put(dev); 2194 out: 2195 mutex_unlock(&po->pg_vec_lock); 2196 return err; 2197 } 2198 2199 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2200 size_t reserve, size_t len, 2201 size_t linear, int noblock, 2202 int *err) 2203 { 2204 struct sk_buff *skb; 2205 2206 /* Under a page? Don't bother with paged skb. */ 2207 if (prepad + len < PAGE_SIZE || !linear) 2208 linear = len; 2209 2210 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2211 err, 0); 2212 if (!skb) 2213 return NULL; 2214 2215 skb_reserve(skb, reserve); 2216 skb_put(skb, linear); 2217 skb->data_len = len - linear; 2218 skb->len += len - linear; 2219 2220 return skb; 2221 } 2222 2223 static int packet_snd(struct socket *sock, 2224 struct msghdr *msg, size_t len) 2225 { 2226 struct sock *sk = sock->sk; 2227 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2228 struct sk_buff *skb; 2229 struct net_device *dev; 2230 __be16 proto; 2231 unsigned char *addr; 2232 int err, reserve = 0; 2233 struct virtio_net_hdr vnet_hdr = { 0 }; 2234 int offset = 0; 2235 int vnet_hdr_len; 2236 struct packet_sock *po = pkt_sk(sk); 2237 unsigned short gso_type = 0; 2238 int hlen, tlen; 2239 int extra_len = 0; 2240 2241 /* 2242 * Get and verify the address. 2243 */ 2244 2245 if (saddr == NULL) { 2246 dev = packet_cached_dev_get(po); 2247 proto = po->num; 2248 addr = NULL; 2249 } else { 2250 err = -EINVAL; 2251 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2252 goto out; 2253 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2254 goto out; 2255 proto = saddr->sll_protocol; 2256 addr = saddr->sll_addr; 2257 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2258 } 2259 2260 err = -ENXIO; 2261 if (unlikely(dev == NULL)) 2262 goto out_unlock; 2263 err = -ENETDOWN; 2264 if (unlikely(!(dev->flags & IFF_UP))) 2265 goto out_unlock; 2266 2267 if (sock->type == SOCK_RAW) 2268 reserve = dev->hard_header_len; 2269 if (po->has_vnet_hdr) { 2270 vnet_hdr_len = sizeof(vnet_hdr); 2271 2272 err = -EINVAL; 2273 if (len < vnet_hdr_len) 2274 goto out_unlock; 2275 2276 len -= vnet_hdr_len; 2277 2278 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2279 vnet_hdr_len); 2280 if (err < 0) 2281 goto out_unlock; 2282 2283 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2284 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2285 vnet_hdr.hdr_len)) 2286 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2287 vnet_hdr.csum_offset + 2; 2288 2289 err = -EINVAL; 2290 if (vnet_hdr.hdr_len > len) 2291 goto out_unlock; 2292 2293 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2294 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2295 case VIRTIO_NET_HDR_GSO_TCPV4: 2296 gso_type = SKB_GSO_TCPV4; 2297 break; 2298 case VIRTIO_NET_HDR_GSO_TCPV6: 2299 gso_type = SKB_GSO_TCPV6; 2300 break; 2301 case VIRTIO_NET_HDR_GSO_UDP: 2302 gso_type = SKB_GSO_UDP; 2303 break; 2304 default: 2305 goto out_unlock; 2306 } 2307 2308 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2309 gso_type |= SKB_GSO_TCP_ECN; 2310 2311 if (vnet_hdr.gso_size == 0) 2312 goto out_unlock; 2313 2314 } 2315 } 2316 2317 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2318 if (!netif_supports_nofcs(dev)) { 2319 err = -EPROTONOSUPPORT; 2320 goto out_unlock; 2321 } 2322 extra_len = 4; /* We're doing our own CRC */ 2323 } 2324 2325 err = -EMSGSIZE; 2326 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2327 goto out_unlock; 2328 2329 err = -ENOBUFS; 2330 hlen = LL_RESERVED_SPACE(dev); 2331 tlen = dev->needed_tailroom; 2332 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2333 msg->msg_flags & MSG_DONTWAIT, &err); 2334 if (skb == NULL) 2335 goto out_unlock; 2336 2337 skb_set_network_header(skb, reserve); 2338 2339 err = -EINVAL; 2340 if (sock->type == SOCK_DGRAM && 2341 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2342 goto out_free; 2343 2344 /* Returns -EFAULT on error */ 2345 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2346 if (err) 2347 goto out_free; 2348 2349 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2350 2351 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2352 /* Earlier code assumed this would be a VLAN pkt, 2353 * double-check this now that we have the actual 2354 * packet in hand. 2355 */ 2356 struct ethhdr *ehdr; 2357 skb_reset_mac_header(skb); 2358 ehdr = eth_hdr(skb); 2359 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2360 err = -EMSGSIZE; 2361 goto out_free; 2362 } 2363 } 2364 2365 skb->protocol = proto; 2366 skb->dev = dev; 2367 skb->priority = sk->sk_priority; 2368 skb->mark = sk->sk_mark; 2369 2370 if (po->has_vnet_hdr) { 2371 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2372 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2373 vnet_hdr.csum_offset)) { 2374 err = -EINVAL; 2375 goto out_free; 2376 } 2377 } 2378 2379 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2380 skb_shinfo(skb)->gso_type = gso_type; 2381 2382 /* Header must be checked, and gso_segs computed. */ 2383 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2384 skb_shinfo(skb)->gso_segs = 0; 2385 2386 len += vnet_hdr_len; 2387 } 2388 2389 skb_probe_transport_header(skb, reserve); 2390 2391 if (unlikely(extra_len == 4)) 2392 skb->no_fcs = 1; 2393 2394 /* 2395 * Now send it 2396 */ 2397 2398 err = dev_queue_xmit(skb); 2399 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2400 goto out_unlock; 2401 2402 dev_put(dev); 2403 2404 return len; 2405 2406 out_free: 2407 kfree_skb(skb); 2408 out_unlock: 2409 if (dev) 2410 dev_put(dev); 2411 out: 2412 return err; 2413 } 2414 2415 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2416 struct msghdr *msg, size_t len) 2417 { 2418 struct sock *sk = sock->sk; 2419 struct packet_sock *po = pkt_sk(sk); 2420 if (po->tx_ring.pg_vec) 2421 return tpacket_snd(po, msg); 2422 else 2423 return packet_snd(sock, msg, len); 2424 } 2425 2426 /* 2427 * Close a PACKET socket. This is fairly simple. We immediately go 2428 * to 'closed' state and remove our protocol entry in the device list. 2429 */ 2430 2431 static int packet_release(struct socket *sock) 2432 { 2433 struct sock *sk = sock->sk; 2434 struct packet_sock *po; 2435 struct net *net; 2436 union tpacket_req_u req_u; 2437 2438 if (!sk) 2439 return 0; 2440 2441 net = sock_net(sk); 2442 po = pkt_sk(sk); 2443 2444 mutex_lock(&net->packet.sklist_lock); 2445 sk_del_node_init_rcu(sk); 2446 mutex_unlock(&net->packet.sklist_lock); 2447 2448 preempt_disable(); 2449 sock_prot_inuse_add(net, sk->sk_prot, -1); 2450 preempt_enable(); 2451 2452 spin_lock(&po->bind_lock); 2453 unregister_prot_hook(sk, false); 2454 if (po->prot_hook.dev) { 2455 dev_put(po->prot_hook.dev); 2456 po->prot_hook.dev = NULL; 2457 } 2458 spin_unlock(&po->bind_lock); 2459 2460 packet_flush_mclist(sk); 2461 2462 if (po->rx_ring.pg_vec) { 2463 memset(&req_u, 0, sizeof(req_u)); 2464 packet_set_ring(sk, &req_u, 1, 0); 2465 } 2466 2467 if (po->tx_ring.pg_vec) { 2468 memset(&req_u, 0, sizeof(req_u)); 2469 packet_set_ring(sk, &req_u, 1, 1); 2470 } 2471 2472 fanout_release(sk); 2473 2474 synchronize_net(); 2475 /* 2476 * Now the socket is dead. No more input will appear. 2477 */ 2478 sock_orphan(sk); 2479 sock->sk = NULL; 2480 2481 /* Purge queues */ 2482 2483 skb_queue_purge(&sk->sk_receive_queue); 2484 sk_refcnt_debug_release(sk); 2485 2486 sock_put(sk); 2487 return 0; 2488 } 2489 2490 /* 2491 * Attach a packet hook. 2492 */ 2493 2494 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2495 { 2496 struct packet_sock *po = pkt_sk(sk); 2497 2498 if (po->fanout) { 2499 if (dev) 2500 dev_put(dev); 2501 2502 return -EINVAL; 2503 } 2504 2505 lock_sock(sk); 2506 2507 spin_lock(&po->bind_lock); 2508 unregister_prot_hook(sk, true); 2509 po->num = protocol; 2510 po->prot_hook.type = protocol; 2511 if (po->prot_hook.dev) 2512 dev_put(po->prot_hook.dev); 2513 po->prot_hook.dev = dev; 2514 2515 po->ifindex = dev ? dev->ifindex : 0; 2516 2517 if (protocol == 0) 2518 goto out_unlock; 2519 2520 if (!dev || (dev->flags & IFF_UP)) { 2521 register_prot_hook(sk); 2522 } else { 2523 sk->sk_err = ENETDOWN; 2524 if (!sock_flag(sk, SOCK_DEAD)) 2525 sk->sk_error_report(sk); 2526 } 2527 2528 out_unlock: 2529 spin_unlock(&po->bind_lock); 2530 release_sock(sk); 2531 return 0; 2532 } 2533 2534 /* 2535 * Bind a packet socket to a device 2536 */ 2537 2538 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2539 int addr_len) 2540 { 2541 struct sock *sk = sock->sk; 2542 char name[15]; 2543 struct net_device *dev; 2544 int err = -ENODEV; 2545 2546 /* 2547 * Check legality 2548 */ 2549 2550 if (addr_len != sizeof(struct sockaddr)) 2551 return -EINVAL; 2552 strlcpy(name, uaddr->sa_data, sizeof(name)); 2553 2554 dev = dev_get_by_name(sock_net(sk), name); 2555 if (dev) 2556 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2557 return err; 2558 } 2559 2560 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2561 { 2562 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2563 struct sock *sk = sock->sk; 2564 struct net_device *dev = NULL; 2565 int err; 2566 2567 2568 /* 2569 * Check legality 2570 */ 2571 2572 if (addr_len < sizeof(struct sockaddr_ll)) 2573 return -EINVAL; 2574 if (sll->sll_family != AF_PACKET) 2575 return -EINVAL; 2576 2577 if (sll->sll_ifindex) { 2578 err = -ENODEV; 2579 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2580 if (dev == NULL) 2581 goto out; 2582 } 2583 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2584 2585 out: 2586 return err; 2587 } 2588 2589 static struct proto packet_proto = { 2590 .name = "PACKET", 2591 .owner = THIS_MODULE, 2592 .obj_size = sizeof(struct packet_sock), 2593 }; 2594 2595 /* 2596 * Create a packet of type SOCK_PACKET. 2597 */ 2598 2599 static int packet_create(struct net *net, struct socket *sock, int protocol, 2600 int kern) 2601 { 2602 struct sock *sk; 2603 struct packet_sock *po; 2604 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2605 int err; 2606 2607 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 2608 return -EPERM; 2609 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2610 sock->type != SOCK_PACKET) 2611 return -ESOCKTNOSUPPORT; 2612 2613 sock->state = SS_UNCONNECTED; 2614 2615 err = -ENOBUFS; 2616 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2617 if (sk == NULL) 2618 goto out; 2619 2620 sock->ops = &packet_ops; 2621 if (sock->type == SOCK_PACKET) 2622 sock->ops = &packet_ops_spkt; 2623 2624 sock_init_data(sock, sk); 2625 2626 po = pkt_sk(sk); 2627 sk->sk_family = PF_PACKET; 2628 po->num = proto; 2629 RCU_INIT_POINTER(po->cached_dev, NULL); 2630 2631 sk->sk_destruct = packet_sock_destruct; 2632 sk_refcnt_debug_inc(sk); 2633 2634 /* 2635 * Attach a protocol block 2636 */ 2637 2638 spin_lock_init(&po->bind_lock); 2639 mutex_init(&po->pg_vec_lock); 2640 po->prot_hook.func = packet_rcv; 2641 2642 if (sock->type == SOCK_PACKET) 2643 po->prot_hook.func = packet_rcv_spkt; 2644 2645 po->prot_hook.af_packet_priv = sk; 2646 2647 if (proto) { 2648 po->prot_hook.type = proto; 2649 register_prot_hook(sk); 2650 } 2651 2652 mutex_lock(&net->packet.sklist_lock); 2653 sk_add_node_rcu(sk, &net->packet.sklist); 2654 mutex_unlock(&net->packet.sklist_lock); 2655 2656 preempt_disable(); 2657 sock_prot_inuse_add(net, &packet_proto, 1); 2658 preempt_enable(); 2659 2660 return 0; 2661 out: 2662 return err; 2663 } 2664 2665 /* 2666 * Pull a packet from our receive queue and hand it to the user. 2667 * If necessary we block. 2668 */ 2669 2670 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2671 struct msghdr *msg, size_t len, int flags) 2672 { 2673 struct sock *sk = sock->sk; 2674 struct sk_buff *skb; 2675 int copied, err; 2676 int vnet_hdr_len = 0; 2677 2678 err = -EINVAL; 2679 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2680 goto out; 2681 2682 #if 0 2683 /* What error should we return now? EUNATTACH? */ 2684 if (pkt_sk(sk)->ifindex < 0) 2685 return -ENODEV; 2686 #endif 2687 2688 if (flags & MSG_ERRQUEUE) { 2689 err = sock_recv_errqueue(sk, msg, len, 2690 SOL_PACKET, PACKET_TX_TIMESTAMP); 2691 goto out; 2692 } 2693 2694 /* 2695 * Call the generic datagram receiver. This handles all sorts 2696 * of horrible races and re-entrancy so we can forget about it 2697 * in the protocol layers. 2698 * 2699 * Now it will return ENETDOWN, if device have just gone down, 2700 * but then it will block. 2701 */ 2702 2703 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2704 2705 /* 2706 * An error occurred so return it. Because skb_recv_datagram() 2707 * handles the blocking we don't see and worry about blocking 2708 * retries. 2709 */ 2710 2711 if (skb == NULL) 2712 goto out; 2713 2714 if (pkt_sk(sk)->has_vnet_hdr) { 2715 struct virtio_net_hdr vnet_hdr = { 0 }; 2716 2717 err = -EINVAL; 2718 vnet_hdr_len = sizeof(vnet_hdr); 2719 if (len < vnet_hdr_len) 2720 goto out_free; 2721 2722 len -= vnet_hdr_len; 2723 2724 if (skb_is_gso(skb)) { 2725 struct skb_shared_info *sinfo = skb_shinfo(skb); 2726 2727 /* This is a hint as to how much should be linear. */ 2728 vnet_hdr.hdr_len = skb_headlen(skb); 2729 vnet_hdr.gso_size = sinfo->gso_size; 2730 if (sinfo->gso_type & SKB_GSO_TCPV4) 2731 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2732 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2733 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2734 else if (sinfo->gso_type & SKB_GSO_UDP) 2735 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2736 else if (sinfo->gso_type & SKB_GSO_FCOE) 2737 goto out_free; 2738 else 2739 BUG(); 2740 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2741 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2742 } else 2743 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2744 2745 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2746 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2747 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2748 vnet_hdr.csum_offset = skb->csum_offset; 2749 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2750 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2751 } /* else everything is zero */ 2752 2753 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2754 vnet_hdr_len); 2755 if (err < 0) 2756 goto out_free; 2757 } 2758 2759 /* You lose any data beyond the buffer you gave. If it worries 2760 * a user program they can ask the device for its MTU 2761 * anyway. 2762 */ 2763 copied = skb->len; 2764 if (copied > len) { 2765 copied = len; 2766 msg->msg_flags |= MSG_TRUNC; 2767 } 2768 2769 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2770 if (err) 2771 goto out_free; 2772 2773 sock_recv_ts_and_drops(msg, sk, skb); 2774 2775 if (msg->msg_name) { 2776 /* If the address length field is there to be filled 2777 * in, we fill it in now. 2778 */ 2779 if (sock->type == SOCK_PACKET) { 2780 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2781 } else { 2782 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 2783 msg->msg_namelen = sll->sll_halen + 2784 offsetof(struct sockaddr_ll, sll_addr); 2785 } 2786 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2787 msg->msg_namelen); 2788 } 2789 2790 if (pkt_sk(sk)->auxdata) { 2791 struct tpacket_auxdata aux; 2792 2793 aux.tp_status = TP_STATUS_USER; 2794 if (skb->ip_summed == CHECKSUM_PARTIAL) 2795 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2796 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2797 aux.tp_snaplen = skb->len; 2798 aux.tp_mac = 0; 2799 aux.tp_net = skb_network_offset(skb); 2800 if (vlan_tx_tag_present(skb)) { 2801 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2802 aux.tp_status |= TP_STATUS_VLAN_VALID; 2803 } else { 2804 aux.tp_vlan_tci = 0; 2805 } 2806 aux.tp_padding = 0; 2807 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2808 } 2809 2810 /* 2811 * Free or return the buffer as appropriate. Again this 2812 * hides all the races and re-entrancy issues from us. 2813 */ 2814 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2815 2816 out_free: 2817 skb_free_datagram(sk, skb); 2818 out: 2819 return err; 2820 } 2821 2822 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2823 int *uaddr_len, int peer) 2824 { 2825 struct net_device *dev; 2826 struct sock *sk = sock->sk; 2827 2828 if (peer) 2829 return -EOPNOTSUPP; 2830 2831 uaddr->sa_family = AF_PACKET; 2832 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 2833 rcu_read_lock(); 2834 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2835 if (dev) 2836 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 2837 rcu_read_unlock(); 2838 *uaddr_len = sizeof(*uaddr); 2839 2840 return 0; 2841 } 2842 2843 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2844 int *uaddr_len, int peer) 2845 { 2846 struct net_device *dev; 2847 struct sock *sk = sock->sk; 2848 struct packet_sock *po = pkt_sk(sk); 2849 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2850 2851 if (peer) 2852 return -EOPNOTSUPP; 2853 2854 sll->sll_family = AF_PACKET; 2855 sll->sll_ifindex = po->ifindex; 2856 sll->sll_protocol = po->num; 2857 sll->sll_pkttype = 0; 2858 rcu_read_lock(); 2859 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2860 if (dev) { 2861 sll->sll_hatype = dev->type; 2862 sll->sll_halen = dev->addr_len; 2863 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2864 } else { 2865 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2866 sll->sll_halen = 0; 2867 } 2868 rcu_read_unlock(); 2869 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2870 2871 return 0; 2872 } 2873 2874 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2875 int what) 2876 { 2877 switch (i->type) { 2878 case PACKET_MR_MULTICAST: 2879 if (i->alen != dev->addr_len) 2880 return -EINVAL; 2881 if (what > 0) 2882 return dev_mc_add(dev, i->addr); 2883 else 2884 return dev_mc_del(dev, i->addr); 2885 break; 2886 case PACKET_MR_PROMISC: 2887 return dev_set_promiscuity(dev, what); 2888 break; 2889 case PACKET_MR_ALLMULTI: 2890 return dev_set_allmulti(dev, what); 2891 break; 2892 case PACKET_MR_UNICAST: 2893 if (i->alen != dev->addr_len) 2894 return -EINVAL; 2895 if (what > 0) 2896 return dev_uc_add(dev, i->addr); 2897 else 2898 return dev_uc_del(dev, i->addr); 2899 break; 2900 default: 2901 break; 2902 } 2903 return 0; 2904 } 2905 2906 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2907 { 2908 for ( ; i; i = i->next) { 2909 if (i->ifindex == dev->ifindex) 2910 packet_dev_mc(dev, i, what); 2911 } 2912 } 2913 2914 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2915 { 2916 struct packet_sock *po = pkt_sk(sk); 2917 struct packet_mclist *ml, *i; 2918 struct net_device *dev; 2919 int err; 2920 2921 rtnl_lock(); 2922 2923 err = -ENODEV; 2924 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2925 if (!dev) 2926 goto done; 2927 2928 err = -EINVAL; 2929 if (mreq->mr_alen > dev->addr_len) 2930 goto done; 2931 2932 err = -ENOBUFS; 2933 i = kmalloc(sizeof(*i), GFP_KERNEL); 2934 if (i == NULL) 2935 goto done; 2936 2937 err = 0; 2938 for (ml = po->mclist; ml; ml = ml->next) { 2939 if (ml->ifindex == mreq->mr_ifindex && 2940 ml->type == mreq->mr_type && 2941 ml->alen == mreq->mr_alen && 2942 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2943 ml->count++; 2944 /* Free the new element ... */ 2945 kfree(i); 2946 goto done; 2947 } 2948 } 2949 2950 i->type = mreq->mr_type; 2951 i->ifindex = mreq->mr_ifindex; 2952 i->alen = mreq->mr_alen; 2953 memcpy(i->addr, mreq->mr_address, i->alen); 2954 i->count = 1; 2955 i->next = po->mclist; 2956 po->mclist = i; 2957 err = packet_dev_mc(dev, i, 1); 2958 if (err) { 2959 po->mclist = i->next; 2960 kfree(i); 2961 } 2962 2963 done: 2964 rtnl_unlock(); 2965 return err; 2966 } 2967 2968 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2969 { 2970 struct packet_mclist *ml, **mlp; 2971 2972 rtnl_lock(); 2973 2974 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 2975 if (ml->ifindex == mreq->mr_ifindex && 2976 ml->type == mreq->mr_type && 2977 ml->alen == mreq->mr_alen && 2978 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2979 if (--ml->count == 0) { 2980 struct net_device *dev; 2981 *mlp = ml->next; 2982 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 2983 if (dev) 2984 packet_dev_mc(dev, ml, -1); 2985 kfree(ml); 2986 } 2987 rtnl_unlock(); 2988 return 0; 2989 } 2990 } 2991 rtnl_unlock(); 2992 return -EADDRNOTAVAIL; 2993 } 2994 2995 static void packet_flush_mclist(struct sock *sk) 2996 { 2997 struct packet_sock *po = pkt_sk(sk); 2998 struct packet_mclist *ml; 2999 3000 if (!po->mclist) 3001 return; 3002 3003 rtnl_lock(); 3004 while ((ml = po->mclist) != NULL) { 3005 struct net_device *dev; 3006 3007 po->mclist = ml->next; 3008 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3009 if (dev != NULL) 3010 packet_dev_mc(dev, ml, -1); 3011 kfree(ml); 3012 } 3013 rtnl_unlock(); 3014 } 3015 3016 static int 3017 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3018 { 3019 struct sock *sk = sock->sk; 3020 struct packet_sock *po = pkt_sk(sk); 3021 int ret; 3022 3023 if (level != SOL_PACKET) 3024 return -ENOPROTOOPT; 3025 3026 switch (optname) { 3027 case PACKET_ADD_MEMBERSHIP: 3028 case PACKET_DROP_MEMBERSHIP: 3029 { 3030 struct packet_mreq_max mreq; 3031 int len = optlen; 3032 memset(&mreq, 0, sizeof(mreq)); 3033 if (len < sizeof(struct packet_mreq)) 3034 return -EINVAL; 3035 if (len > sizeof(mreq)) 3036 len = sizeof(mreq); 3037 if (copy_from_user(&mreq, optval, len)) 3038 return -EFAULT; 3039 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3040 return -EINVAL; 3041 if (optname == PACKET_ADD_MEMBERSHIP) 3042 ret = packet_mc_add(sk, &mreq); 3043 else 3044 ret = packet_mc_drop(sk, &mreq); 3045 return ret; 3046 } 3047 3048 case PACKET_RX_RING: 3049 case PACKET_TX_RING: 3050 { 3051 union tpacket_req_u req_u; 3052 int len; 3053 3054 switch (po->tp_version) { 3055 case TPACKET_V1: 3056 case TPACKET_V2: 3057 len = sizeof(req_u.req); 3058 break; 3059 case TPACKET_V3: 3060 default: 3061 len = sizeof(req_u.req3); 3062 break; 3063 } 3064 if (optlen < len) 3065 return -EINVAL; 3066 if (pkt_sk(sk)->has_vnet_hdr) 3067 return -EINVAL; 3068 if (copy_from_user(&req_u.req, optval, len)) 3069 return -EFAULT; 3070 return packet_set_ring(sk, &req_u, 0, 3071 optname == PACKET_TX_RING); 3072 } 3073 case PACKET_COPY_THRESH: 3074 { 3075 int val; 3076 3077 if (optlen != sizeof(val)) 3078 return -EINVAL; 3079 if (copy_from_user(&val, optval, sizeof(val))) 3080 return -EFAULT; 3081 3082 pkt_sk(sk)->copy_thresh = val; 3083 return 0; 3084 } 3085 case PACKET_VERSION: 3086 { 3087 int val; 3088 3089 if (optlen != sizeof(val)) 3090 return -EINVAL; 3091 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3092 return -EBUSY; 3093 if (copy_from_user(&val, optval, sizeof(val))) 3094 return -EFAULT; 3095 switch (val) { 3096 case TPACKET_V1: 3097 case TPACKET_V2: 3098 case TPACKET_V3: 3099 po->tp_version = val; 3100 return 0; 3101 default: 3102 return -EINVAL; 3103 } 3104 } 3105 case PACKET_RESERVE: 3106 { 3107 unsigned int val; 3108 3109 if (optlen != sizeof(val)) 3110 return -EINVAL; 3111 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3112 return -EBUSY; 3113 if (copy_from_user(&val, optval, sizeof(val))) 3114 return -EFAULT; 3115 po->tp_reserve = val; 3116 return 0; 3117 } 3118 case PACKET_LOSS: 3119 { 3120 unsigned int val; 3121 3122 if (optlen != sizeof(val)) 3123 return -EINVAL; 3124 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3125 return -EBUSY; 3126 if (copy_from_user(&val, optval, sizeof(val))) 3127 return -EFAULT; 3128 po->tp_loss = !!val; 3129 return 0; 3130 } 3131 case PACKET_AUXDATA: 3132 { 3133 int val; 3134 3135 if (optlen < sizeof(val)) 3136 return -EINVAL; 3137 if (copy_from_user(&val, optval, sizeof(val))) 3138 return -EFAULT; 3139 3140 po->auxdata = !!val; 3141 return 0; 3142 } 3143 case PACKET_ORIGDEV: 3144 { 3145 int val; 3146 3147 if (optlen < sizeof(val)) 3148 return -EINVAL; 3149 if (copy_from_user(&val, optval, sizeof(val))) 3150 return -EFAULT; 3151 3152 po->origdev = !!val; 3153 return 0; 3154 } 3155 case PACKET_VNET_HDR: 3156 { 3157 int val; 3158 3159 if (sock->type != SOCK_RAW) 3160 return -EINVAL; 3161 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3162 return -EBUSY; 3163 if (optlen < sizeof(val)) 3164 return -EINVAL; 3165 if (copy_from_user(&val, optval, sizeof(val))) 3166 return -EFAULT; 3167 3168 po->has_vnet_hdr = !!val; 3169 return 0; 3170 } 3171 case PACKET_TIMESTAMP: 3172 { 3173 int val; 3174 3175 if (optlen != sizeof(val)) 3176 return -EINVAL; 3177 if (copy_from_user(&val, optval, sizeof(val))) 3178 return -EFAULT; 3179 3180 po->tp_tstamp = val; 3181 return 0; 3182 } 3183 case PACKET_FANOUT: 3184 { 3185 int val; 3186 3187 if (optlen != sizeof(val)) 3188 return -EINVAL; 3189 if (copy_from_user(&val, optval, sizeof(val))) 3190 return -EFAULT; 3191 3192 return fanout_add(sk, val & 0xffff, val >> 16); 3193 } 3194 case PACKET_TX_HAS_OFF: 3195 { 3196 unsigned int val; 3197 3198 if (optlen != sizeof(val)) 3199 return -EINVAL; 3200 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3201 return -EBUSY; 3202 if (copy_from_user(&val, optval, sizeof(val))) 3203 return -EFAULT; 3204 po->tp_tx_has_off = !!val; 3205 return 0; 3206 } 3207 default: 3208 return -ENOPROTOOPT; 3209 } 3210 } 3211 3212 static int packet_getsockopt(struct socket *sock, int level, int optname, 3213 char __user *optval, int __user *optlen) 3214 { 3215 int len; 3216 int val, lv = sizeof(val); 3217 struct sock *sk = sock->sk; 3218 struct packet_sock *po = pkt_sk(sk); 3219 void *data = &val; 3220 union tpacket_stats_u st; 3221 3222 if (level != SOL_PACKET) 3223 return -ENOPROTOOPT; 3224 3225 if (get_user(len, optlen)) 3226 return -EFAULT; 3227 3228 if (len < 0) 3229 return -EINVAL; 3230 3231 switch (optname) { 3232 case PACKET_STATISTICS: 3233 spin_lock_bh(&sk->sk_receive_queue.lock); 3234 memcpy(&st, &po->stats, sizeof(st)); 3235 memset(&po->stats, 0, sizeof(po->stats)); 3236 spin_unlock_bh(&sk->sk_receive_queue.lock); 3237 3238 if (po->tp_version == TPACKET_V3) { 3239 lv = sizeof(struct tpacket_stats_v3); 3240 st.stats3.tp_packets += st.stats3.tp_drops; 3241 data = &st.stats3; 3242 } else { 3243 lv = sizeof(struct tpacket_stats); 3244 st.stats1.tp_packets += st.stats1.tp_drops; 3245 data = &st.stats1; 3246 } 3247 3248 break; 3249 case PACKET_AUXDATA: 3250 val = po->auxdata; 3251 break; 3252 case PACKET_ORIGDEV: 3253 val = po->origdev; 3254 break; 3255 case PACKET_VNET_HDR: 3256 val = po->has_vnet_hdr; 3257 break; 3258 case PACKET_VERSION: 3259 val = po->tp_version; 3260 break; 3261 case PACKET_HDRLEN: 3262 if (len > sizeof(int)) 3263 len = sizeof(int); 3264 if (copy_from_user(&val, optval, len)) 3265 return -EFAULT; 3266 switch (val) { 3267 case TPACKET_V1: 3268 val = sizeof(struct tpacket_hdr); 3269 break; 3270 case TPACKET_V2: 3271 val = sizeof(struct tpacket2_hdr); 3272 break; 3273 case TPACKET_V3: 3274 val = sizeof(struct tpacket3_hdr); 3275 break; 3276 default: 3277 return -EINVAL; 3278 } 3279 break; 3280 case PACKET_RESERVE: 3281 val = po->tp_reserve; 3282 break; 3283 case PACKET_LOSS: 3284 val = po->tp_loss; 3285 break; 3286 case PACKET_TIMESTAMP: 3287 val = po->tp_tstamp; 3288 break; 3289 case PACKET_FANOUT: 3290 val = (po->fanout ? 3291 ((u32)po->fanout->id | 3292 ((u32)po->fanout->type << 16) | 3293 ((u32)po->fanout->flags << 24)) : 3294 0); 3295 break; 3296 case PACKET_TX_HAS_OFF: 3297 val = po->tp_tx_has_off; 3298 break; 3299 default: 3300 return -ENOPROTOOPT; 3301 } 3302 3303 if (len > lv) 3304 len = lv; 3305 if (put_user(len, optlen)) 3306 return -EFAULT; 3307 if (copy_to_user(optval, data, len)) 3308 return -EFAULT; 3309 return 0; 3310 } 3311 3312 3313 static int packet_notifier(struct notifier_block *this, 3314 unsigned long msg, void *ptr) 3315 { 3316 struct sock *sk; 3317 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3318 struct net *net = dev_net(dev); 3319 3320 rcu_read_lock(); 3321 sk_for_each_rcu(sk, &net->packet.sklist) { 3322 struct packet_sock *po = pkt_sk(sk); 3323 3324 switch (msg) { 3325 case NETDEV_UNREGISTER: 3326 if (po->mclist) 3327 packet_dev_mclist(dev, po->mclist, -1); 3328 /* fallthrough */ 3329 3330 case NETDEV_DOWN: 3331 if (dev->ifindex == po->ifindex) { 3332 spin_lock(&po->bind_lock); 3333 if (po->running) { 3334 __unregister_prot_hook(sk, false); 3335 sk->sk_err = ENETDOWN; 3336 if (!sock_flag(sk, SOCK_DEAD)) 3337 sk->sk_error_report(sk); 3338 } 3339 if (msg == NETDEV_UNREGISTER) { 3340 po->ifindex = -1; 3341 if (po->prot_hook.dev) 3342 dev_put(po->prot_hook.dev); 3343 po->prot_hook.dev = NULL; 3344 } 3345 spin_unlock(&po->bind_lock); 3346 } 3347 break; 3348 case NETDEV_UP: 3349 if (dev->ifindex == po->ifindex) { 3350 spin_lock(&po->bind_lock); 3351 if (po->num) 3352 register_prot_hook(sk); 3353 spin_unlock(&po->bind_lock); 3354 } 3355 break; 3356 } 3357 } 3358 rcu_read_unlock(); 3359 return NOTIFY_DONE; 3360 } 3361 3362 3363 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3364 unsigned long arg) 3365 { 3366 struct sock *sk = sock->sk; 3367 3368 switch (cmd) { 3369 case SIOCOUTQ: 3370 { 3371 int amount = sk_wmem_alloc_get(sk); 3372 3373 return put_user(amount, (int __user *)arg); 3374 } 3375 case SIOCINQ: 3376 { 3377 struct sk_buff *skb; 3378 int amount = 0; 3379 3380 spin_lock_bh(&sk->sk_receive_queue.lock); 3381 skb = skb_peek(&sk->sk_receive_queue); 3382 if (skb) 3383 amount = skb->len; 3384 spin_unlock_bh(&sk->sk_receive_queue.lock); 3385 return put_user(amount, (int __user *)arg); 3386 } 3387 case SIOCGSTAMP: 3388 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3389 case SIOCGSTAMPNS: 3390 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3391 3392 #ifdef CONFIG_INET 3393 case SIOCADDRT: 3394 case SIOCDELRT: 3395 case SIOCDARP: 3396 case SIOCGARP: 3397 case SIOCSARP: 3398 case SIOCGIFADDR: 3399 case SIOCSIFADDR: 3400 case SIOCGIFBRDADDR: 3401 case SIOCSIFBRDADDR: 3402 case SIOCGIFNETMASK: 3403 case SIOCSIFNETMASK: 3404 case SIOCGIFDSTADDR: 3405 case SIOCSIFDSTADDR: 3406 case SIOCSIFFLAGS: 3407 return inet_dgram_ops.ioctl(sock, cmd, arg); 3408 #endif 3409 3410 default: 3411 return -ENOIOCTLCMD; 3412 } 3413 return 0; 3414 } 3415 3416 static unsigned int packet_poll(struct file *file, struct socket *sock, 3417 poll_table *wait) 3418 { 3419 struct sock *sk = sock->sk; 3420 struct packet_sock *po = pkt_sk(sk); 3421 unsigned int mask = datagram_poll(file, sock, wait); 3422 3423 spin_lock_bh(&sk->sk_receive_queue.lock); 3424 if (po->rx_ring.pg_vec) { 3425 if (!packet_previous_rx_frame(po, &po->rx_ring, 3426 TP_STATUS_KERNEL)) 3427 mask |= POLLIN | POLLRDNORM; 3428 } 3429 spin_unlock_bh(&sk->sk_receive_queue.lock); 3430 spin_lock_bh(&sk->sk_write_queue.lock); 3431 if (po->tx_ring.pg_vec) { 3432 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3433 mask |= POLLOUT | POLLWRNORM; 3434 } 3435 spin_unlock_bh(&sk->sk_write_queue.lock); 3436 return mask; 3437 } 3438 3439 3440 /* Dirty? Well, I still did not learn better way to account 3441 * for user mmaps. 3442 */ 3443 3444 static void packet_mm_open(struct vm_area_struct *vma) 3445 { 3446 struct file *file = vma->vm_file; 3447 struct socket *sock = file->private_data; 3448 struct sock *sk = sock->sk; 3449 3450 if (sk) 3451 atomic_inc(&pkt_sk(sk)->mapped); 3452 } 3453 3454 static void packet_mm_close(struct vm_area_struct *vma) 3455 { 3456 struct file *file = vma->vm_file; 3457 struct socket *sock = file->private_data; 3458 struct sock *sk = sock->sk; 3459 3460 if (sk) 3461 atomic_dec(&pkt_sk(sk)->mapped); 3462 } 3463 3464 static const struct vm_operations_struct packet_mmap_ops = { 3465 .open = packet_mm_open, 3466 .close = packet_mm_close, 3467 }; 3468 3469 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3470 unsigned int len) 3471 { 3472 int i; 3473 3474 for (i = 0; i < len; i++) { 3475 if (likely(pg_vec[i].buffer)) { 3476 if (is_vmalloc_addr(pg_vec[i].buffer)) 3477 vfree(pg_vec[i].buffer); 3478 else 3479 free_pages((unsigned long)pg_vec[i].buffer, 3480 order); 3481 pg_vec[i].buffer = NULL; 3482 } 3483 } 3484 kfree(pg_vec); 3485 } 3486 3487 static char *alloc_one_pg_vec_page(unsigned long order) 3488 { 3489 char *buffer = NULL; 3490 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3491 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3492 3493 buffer = (char *) __get_free_pages(gfp_flags, order); 3494 3495 if (buffer) 3496 return buffer; 3497 3498 /* 3499 * __get_free_pages failed, fall back to vmalloc 3500 */ 3501 buffer = vzalloc((1 << order) * PAGE_SIZE); 3502 3503 if (buffer) 3504 return buffer; 3505 3506 /* 3507 * vmalloc failed, lets dig into swap here 3508 */ 3509 gfp_flags &= ~__GFP_NORETRY; 3510 buffer = (char *)__get_free_pages(gfp_flags, order); 3511 if (buffer) 3512 return buffer; 3513 3514 /* 3515 * complete and utter failure 3516 */ 3517 return NULL; 3518 } 3519 3520 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3521 { 3522 unsigned int block_nr = req->tp_block_nr; 3523 struct pgv *pg_vec; 3524 int i; 3525 3526 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3527 if (unlikely(!pg_vec)) 3528 goto out; 3529 3530 for (i = 0; i < block_nr; i++) { 3531 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3532 if (unlikely(!pg_vec[i].buffer)) 3533 goto out_free_pgvec; 3534 } 3535 3536 out: 3537 return pg_vec; 3538 3539 out_free_pgvec: 3540 free_pg_vec(pg_vec, order, block_nr); 3541 pg_vec = NULL; 3542 goto out; 3543 } 3544 3545 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3546 int closing, int tx_ring) 3547 { 3548 struct pgv *pg_vec = NULL; 3549 struct packet_sock *po = pkt_sk(sk); 3550 int was_running, order = 0; 3551 struct packet_ring_buffer *rb; 3552 struct sk_buff_head *rb_queue; 3553 __be16 num; 3554 int err = -EINVAL; 3555 /* Added to avoid minimal code churn */ 3556 struct tpacket_req *req = &req_u->req; 3557 3558 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3559 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3560 WARN(1, "Tx-ring is not supported.\n"); 3561 goto out; 3562 } 3563 3564 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3565 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3566 3567 err = -EBUSY; 3568 if (!closing) { 3569 if (atomic_read(&po->mapped)) 3570 goto out; 3571 if (atomic_read(&rb->pending)) 3572 goto out; 3573 } 3574 3575 if (req->tp_block_nr) { 3576 /* Sanity tests and some calculations */ 3577 err = -EBUSY; 3578 if (unlikely(rb->pg_vec)) 3579 goto out; 3580 3581 switch (po->tp_version) { 3582 case TPACKET_V1: 3583 po->tp_hdrlen = TPACKET_HDRLEN; 3584 break; 3585 case TPACKET_V2: 3586 po->tp_hdrlen = TPACKET2_HDRLEN; 3587 break; 3588 case TPACKET_V3: 3589 po->tp_hdrlen = TPACKET3_HDRLEN; 3590 break; 3591 } 3592 3593 err = -EINVAL; 3594 if (unlikely((int)req->tp_block_size <= 0)) 3595 goto out; 3596 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3597 goto out; 3598 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3599 po->tp_reserve)) 3600 goto out; 3601 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3602 goto out; 3603 3604 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3605 if (unlikely(rb->frames_per_block <= 0)) 3606 goto out; 3607 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3608 req->tp_frame_nr)) 3609 goto out; 3610 3611 err = -ENOMEM; 3612 order = get_order(req->tp_block_size); 3613 pg_vec = alloc_pg_vec(req, order); 3614 if (unlikely(!pg_vec)) 3615 goto out; 3616 switch (po->tp_version) { 3617 case TPACKET_V3: 3618 /* Transmit path is not supported. We checked 3619 * it above but just being paranoid 3620 */ 3621 if (!tx_ring) 3622 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3623 break; 3624 default: 3625 break; 3626 } 3627 } 3628 /* Done */ 3629 else { 3630 err = -EINVAL; 3631 if (unlikely(req->tp_frame_nr)) 3632 goto out; 3633 } 3634 3635 lock_sock(sk); 3636 3637 /* Detach socket from network */ 3638 spin_lock(&po->bind_lock); 3639 was_running = po->running; 3640 num = po->num; 3641 if (was_running) { 3642 po->num = 0; 3643 __unregister_prot_hook(sk, false); 3644 } 3645 spin_unlock(&po->bind_lock); 3646 3647 synchronize_net(); 3648 3649 err = -EBUSY; 3650 mutex_lock(&po->pg_vec_lock); 3651 if (closing || atomic_read(&po->mapped) == 0) { 3652 err = 0; 3653 spin_lock_bh(&rb_queue->lock); 3654 swap(rb->pg_vec, pg_vec); 3655 rb->frame_max = (req->tp_frame_nr - 1); 3656 rb->head = 0; 3657 rb->frame_size = req->tp_frame_size; 3658 spin_unlock_bh(&rb_queue->lock); 3659 3660 swap(rb->pg_vec_order, order); 3661 swap(rb->pg_vec_len, req->tp_block_nr); 3662 3663 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3664 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3665 tpacket_rcv : packet_rcv; 3666 skb_queue_purge(rb_queue); 3667 if (atomic_read(&po->mapped)) 3668 pr_err("packet_mmap: vma is busy: %d\n", 3669 atomic_read(&po->mapped)); 3670 } 3671 mutex_unlock(&po->pg_vec_lock); 3672 3673 spin_lock(&po->bind_lock); 3674 if (was_running) { 3675 po->num = num; 3676 register_prot_hook(sk); 3677 } 3678 spin_unlock(&po->bind_lock); 3679 if (closing && (po->tp_version > TPACKET_V2)) { 3680 /* Because we don't support block-based V3 on tx-ring */ 3681 if (!tx_ring) 3682 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3683 } 3684 release_sock(sk); 3685 3686 if (pg_vec) 3687 free_pg_vec(pg_vec, order, req->tp_block_nr); 3688 out: 3689 return err; 3690 } 3691 3692 static int packet_mmap(struct file *file, struct socket *sock, 3693 struct vm_area_struct *vma) 3694 { 3695 struct sock *sk = sock->sk; 3696 struct packet_sock *po = pkt_sk(sk); 3697 unsigned long size, expected_size; 3698 struct packet_ring_buffer *rb; 3699 unsigned long start; 3700 int err = -EINVAL; 3701 int i; 3702 3703 if (vma->vm_pgoff) 3704 return -EINVAL; 3705 3706 mutex_lock(&po->pg_vec_lock); 3707 3708 expected_size = 0; 3709 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3710 if (rb->pg_vec) { 3711 expected_size += rb->pg_vec_len 3712 * rb->pg_vec_pages 3713 * PAGE_SIZE; 3714 } 3715 } 3716 3717 if (expected_size == 0) 3718 goto out; 3719 3720 size = vma->vm_end - vma->vm_start; 3721 if (size != expected_size) 3722 goto out; 3723 3724 start = vma->vm_start; 3725 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3726 if (rb->pg_vec == NULL) 3727 continue; 3728 3729 for (i = 0; i < rb->pg_vec_len; i++) { 3730 struct page *page; 3731 void *kaddr = rb->pg_vec[i].buffer; 3732 int pg_num; 3733 3734 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3735 page = pgv_to_page(kaddr); 3736 err = vm_insert_page(vma, start, page); 3737 if (unlikely(err)) 3738 goto out; 3739 start += PAGE_SIZE; 3740 kaddr += PAGE_SIZE; 3741 } 3742 } 3743 } 3744 3745 atomic_inc(&po->mapped); 3746 vma->vm_ops = &packet_mmap_ops; 3747 err = 0; 3748 3749 out: 3750 mutex_unlock(&po->pg_vec_lock); 3751 return err; 3752 } 3753 3754 static const struct proto_ops packet_ops_spkt = { 3755 .family = PF_PACKET, 3756 .owner = THIS_MODULE, 3757 .release = packet_release, 3758 .bind = packet_bind_spkt, 3759 .connect = sock_no_connect, 3760 .socketpair = sock_no_socketpair, 3761 .accept = sock_no_accept, 3762 .getname = packet_getname_spkt, 3763 .poll = datagram_poll, 3764 .ioctl = packet_ioctl, 3765 .listen = sock_no_listen, 3766 .shutdown = sock_no_shutdown, 3767 .setsockopt = sock_no_setsockopt, 3768 .getsockopt = sock_no_getsockopt, 3769 .sendmsg = packet_sendmsg_spkt, 3770 .recvmsg = packet_recvmsg, 3771 .mmap = sock_no_mmap, 3772 .sendpage = sock_no_sendpage, 3773 }; 3774 3775 static const struct proto_ops packet_ops = { 3776 .family = PF_PACKET, 3777 .owner = THIS_MODULE, 3778 .release = packet_release, 3779 .bind = packet_bind, 3780 .connect = sock_no_connect, 3781 .socketpair = sock_no_socketpair, 3782 .accept = sock_no_accept, 3783 .getname = packet_getname, 3784 .poll = packet_poll, 3785 .ioctl = packet_ioctl, 3786 .listen = sock_no_listen, 3787 .shutdown = sock_no_shutdown, 3788 .setsockopt = packet_setsockopt, 3789 .getsockopt = packet_getsockopt, 3790 .sendmsg = packet_sendmsg, 3791 .recvmsg = packet_recvmsg, 3792 .mmap = packet_mmap, 3793 .sendpage = sock_no_sendpage, 3794 }; 3795 3796 static const struct net_proto_family packet_family_ops = { 3797 .family = PF_PACKET, 3798 .create = packet_create, 3799 .owner = THIS_MODULE, 3800 }; 3801 3802 static struct notifier_block packet_netdev_notifier = { 3803 .notifier_call = packet_notifier, 3804 }; 3805 3806 #ifdef CONFIG_PROC_FS 3807 3808 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3809 __acquires(RCU) 3810 { 3811 struct net *net = seq_file_net(seq); 3812 3813 rcu_read_lock(); 3814 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3815 } 3816 3817 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3818 { 3819 struct net *net = seq_file_net(seq); 3820 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3821 } 3822 3823 static void packet_seq_stop(struct seq_file *seq, void *v) 3824 __releases(RCU) 3825 { 3826 rcu_read_unlock(); 3827 } 3828 3829 static int packet_seq_show(struct seq_file *seq, void *v) 3830 { 3831 if (v == SEQ_START_TOKEN) 3832 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3833 else { 3834 struct sock *s = sk_entry(v); 3835 const struct packet_sock *po = pkt_sk(s); 3836 3837 seq_printf(seq, 3838 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3839 s, 3840 atomic_read(&s->sk_refcnt), 3841 s->sk_type, 3842 ntohs(po->num), 3843 po->ifindex, 3844 po->running, 3845 atomic_read(&s->sk_rmem_alloc), 3846 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 3847 sock_i_ino(s)); 3848 } 3849 3850 return 0; 3851 } 3852 3853 static const struct seq_operations packet_seq_ops = { 3854 .start = packet_seq_start, 3855 .next = packet_seq_next, 3856 .stop = packet_seq_stop, 3857 .show = packet_seq_show, 3858 }; 3859 3860 static int packet_seq_open(struct inode *inode, struct file *file) 3861 { 3862 return seq_open_net(inode, file, &packet_seq_ops, 3863 sizeof(struct seq_net_private)); 3864 } 3865 3866 static const struct file_operations packet_seq_fops = { 3867 .owner = THIS_MODULE, 3868 .open = packet_seq_open, 3869 .read = seq_read, 3870 .llseek = seq_lseek, 3871 .release = seq_release_net, 3872 }; 3873 3874 #endif 3875 3876 static int __net_init packet_net_init(struct net *net) 3877 { 3878 mutex_init(&net->packet.sklist_lock); 3879 INIT_HLIST_HEAD(&net->packet.sklist); 3880 3881 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 3882 return -ENOMEM; 3883 3884 return 0; 3885 } 3886 3887 static void __net_exit packet_net_exit(struct net *net) 3888 { 3889 remove_proc_entry("packet", net->proc_net); 3890 } 3891 3892 static struct pernet_operations packet_net_ops = { 3893 .init = packet_net_init, 3894 .exit = packet_net_exit, 3895 }; 3896 3897 3898 static void __exit packet_exit(void) 3899 { 3900 unregister_netdevice_notifier(&packet_netdev_notifier); 3901 unregister_pernet_subsys(&packet_net_ops); 3902 sock_unregister(PF_PACKET); 3903 proto_unregister(&packet_proto); 3904 } 3905 3906 static int __init packet_init(void) 3907 { 3908 int rc = proto_register(&packet_proto, 0); 3909 3910 if (rc != 0) 3911 goto out; 3912 3913 sock_register(&packet_family_ops); 3914 register_pernet_subsys(&packet_net_ops); 3915 register_netdevice_notifier(&packet_netdev_notifier); 3916 out: 3917 return rc; 3918 } 3919 3920 module_init(packet_init); 3921 module_exit(packet_exit); 3922 MODULE_LICENSE("GPL"); 3923 MODULE_ALIAS_NETPROTO(PF_PACKET); 3924