1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <asm/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 96 /* 97 Assumptions: 98 - if device has no dev->hard_header routine, it adds and removes ll header 99 inside itself. In this case ll header is invisible outside of device, 100 but higher levels still should reserve dev->hard_header_len. 101 Some devices are enough clever to reallocate skb, when header 102 will not fit to reserved space (tunnel), another ones are silly 103 (PPP). 104 - packet socket receives packets with pulled ll header, 105 so that SOCK_RAW should push it back. 106 107 On receive: 108 ----------- 109 110 Incoming, dev->hard_header!=NULL 111 mac_header -> ll header 112 data -> data 113 114 Outgoing, dev->hard_header!=NULL 115 mac_header -> ll header 116 data -> ll header 117 118 Incoming, dev->hard_header==NULL 119 mac_header -> UNKNOWN position. It is very likely, that it points to ll 120 header. PPP makes it, that is wrong, because introduce 121 assymetry between rx and tx paths. 122 data -> data 123 124 Outgoing, dev->hard_header==NULL 125 mac_header -> data. ll header is still not built! 126 data -> data 127 128 Resume 129 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 130 131 132 On transmit: 133 ------------ 134 135 dev->hard_header != NULL 136 mac_header -> ll header 137 data -> ll header 138 139 dev->hard_header == NULL (ll header is added by device, we cannot control it) 140 mac_header -> data 141 data -> data 142 143 We should set nh.raw on output to correct posistion, 144 packet classifier depends on it. 145 */ 146 147 /* Private packet socket structures. */ 148 149 struct packet_mclist { 150 struct packet_mclist *next; 151 int ifindex; 152 int count; 153 unsigned short type; 154 unsigned short alen; 155 unsigned char addr[MAX_ADDR_LEN]; 156 }; 157 /* identical to struct packet_mreq except it has 158 * a longer address field. 159 */ 160 struct packet_mreq_max { 161 int mr_ifindex; 162 unsigned short mr_type; 163 unsigned short mr_alen; 164 unsigned char mr_address[MAX_ADDR_LEN]; 165 }; 166 167 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 168 int closing, int tx_ring); 169 170 171 #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 /* kbdq - kernel block descriptor queue */ 179 struct tpacket_kbdq_core { 180 struct pgv *pkbdq; 181 unsigned int feature_req_word; 182 unsigned int hdrlen; 183 unsigned char reset_pending_on_curr_blk; 184 unsigned char delete_blk_timer; 185 unsigned short kactive_blk_num; 186 unsigned short blk_sizeof_priv; 187 188 /* last_kactive_blk_num: 189 * trick to see if user-space has caught up 190 * in order to avoid refreshing timer when every single pkt arrives. 191 */ 192 unsigned short last_kactive_blk_num; 193 194 char *pkblk_start; 195 char *pkblk_end; 196 int kblk_size; 197 unsigned int knum_blocks; 198 uint64_t knxt_seq_num; 199 char *prev; 200 char *nxt_offset; 201 struct sk_buff *skb; 202 203 atomic_t blk_fill_in_prog; 204 205 /* Default is set to 8ms */ 206 #define DEFAULT_PRB_RETIRE_TOV (8) 207 208 unsigned short retire_blk_tov; 209 unsigned short version; 210 unsigned long tov_in_jiffies; 211 212 /* timer to retire an outstanding block */ 213 struct timer_list retire_blk_timer; 214 }; 215 216 #define PGV_FROM_VMALLOC 1 217 struct pgv { 218 char *buffer; 219 }; 220 221 struct packet_ring_buffer { 222 struct pgv *pg_vec; 223 unsigned int head; 224 unsigned int frames_per_block; 225 unsigned int frame_size; 226 unsigned int frame_max; 227 228 unsigned int pg_vec_order; 229 unsigned int pg_vec_pages; 230 unsigned int pg_vec_len; 231 232 struct tpacket_kbdq_core prb_bdqc; 233 atomic_t pending; 234 }; 235 236 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 237 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 238 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 239 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 240 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 241 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 242 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 243 244 struct packet_sock; 245 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 246 247 static void *packet_previous_frame(struct packet_sock *po, 248 struct packet_ring_buffer *rb, 249 int status); 250 static void packet_increment_head(struct packet_ring_buffer *buff); 251 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 252 struct tpacket_block_desc *); 253 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 254 struct packet_sock *); 255 static void prb_retire_current_block(struct tpacket_kbdq_core *, 256 struct packet_sock *, unsigned int status); 257 static int prb_queue_frozen(struct tpacket_kbdq_core *); 258 static void prb_open_block(struct tpacket_kbdq_core *, 259 struct tpacket_block_desc *); 260 static void prb_retire_rx_blk_timer_expired(unsigned long); 261 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 262 static void prb_init_blk_timer(struct packet_sock *, 263 struct tpacket_kbdq_core *, 264 void (*func) (unsigned long)); 265 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 266 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 267 struct tpacket3_hdr *); 268 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 269 struct tpacket3_hdr *); 270 static void packet_flush_mclist(struct sock *sk); 271 272 struct packet_fanout; 273 struct packet_sock { 274 /* struct sock has to be the first member of packet_sock */ 275 struct sock sk; 276 struct packet_fanout *fanout; 277 struct tpacket_stats stats; 278 union tpacket_stats_u stats_u; 279 struct packet_ring_buffer rx_ring; 280 struct packet_ring_buffer tx_ring; 281 int copy_thresh; 282 spinlock_t bind_lock; 283 struct mutex pg_vec_lock; 284 unsigned int running:1, /* prot_hook is attached*/ 285 auxdata:1, 286 origdev:1, 287 has_vnet_hdr:1; 288 int ifindex; /* bound device */ 289 __be16 num; 290 struct packet_mclist *mclist; 291 atomic_t mapped; 292 enum tpacket_versions tp_version; 293 unsigned int tp_hdrlen; 294 unsigned int tp_reserve; 295 unsigned int tp_loss:1; 296 unsigned int tp_tstamp; 297 struct packet_type prot_hook ____cacheline_aligned_in_smp; 298 }; 299 300 #define PACKET_FANOUT_MAX 256 301 302 struct packet_fanout { 303 #ifdef CONFIG_NET_NS 304 struct net *net; 305 #endif 306 unsigned int num_members; 307 u16 id; 308 u8 type; 309 u8 defrag; 310 atomic_t rr_cur; 311 struct list_head list; 312 struct sock *arr[PACKET_FANOUT_MAX]; 313 spinlock_t lock; 314 atomic_t sk_ref; 315 struct packet_type prot_hook ____cacheline_aligned_in_smp; 316 }; 317 318 struct packet_skb_cb { 319 unsigned int origlen; 320 union { 321 struct sockaddr_pkt pkt; 322 struct sockaddr_ll ll; 323 } sa; 324 }; 325 326 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 327 328 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 329 #define GET_PBLOCK_DESC(x, bid) \ 330 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 331 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 332 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 333 #define GET_NEXT_PRB_BLK_NUM(x) \ 334 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 335 ((x)->kactive_blk_num+1) : 0) 336 337 static struct packet_sock *pkt_sk(struct sock *sk) 338 { 339 return (struct packet_sock *)sk; 340 } 341 342 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 343 static void __fanout_link(struct sock *sk, struct packet_sock *po); 344 345 /* register_prot_hook must be invoked with the po->bind_lock held, 346 * or from a context in which asynchronous accesses to the packet 347 * socket is not possible (packet_create()). 348 */ 349 static void register_prot_hook(struct sock *sk) 350 { 351 struct packet_sock *po = pkt_sk(sk); 352 if (!po->running) { 353 if (po->fanout) 354 __fanout_link(sk, po); 355 else 356 dev_add_pack(&po->prot_hook); 357 sock_hold(sk); 358 po->running = 1; 359 } 360 } 361 362 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 363 * held. If the sync parameter is true, we will temporarily drop 364 * the po->bind_lock and do a synchronize_net to make sure no 365 * asynchronous packet processing paths still refer to the elements 366 * of po->prot_hook. If the sync parameter is false, it is the 367 * callers responsibility to take care of this. 368 */ 369 static void __unregister_prot_hook(struct sock *sk, bool sync) 370 { 371 struct packet_sock *po = pkt_sk(sk); 372 373 po->running = 0; 374 if (po->fanout) 375 __fanout_unlink(sk, po); 376 else 377 __dev_remove_pack(&po->prot_hook); 378 __sock_put(sk); 379 380 if (sync) { 381 spin_unlock(&po->bind_lock); 382 synchronize_net(); 383 spin_lock(&po->bind_lock); 384 } 385 } 386 387 static void unregister_prot_hook(struct sock *sk, bool sync) 388 { 389 struct packet_sock *po = pkt_sk(sk); 390 391 if (po->running) 392 __unregister_prot_hook(sk, sync); 393 } 394 395 static inline __pure struct page *pgv_to_page(void *addr) 396 { 397 if (is_vmalloc_addr(addr)) 398 return vmalloc_to_page(addr); 399 return virt_to_page(addr); 400 } 401 402 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 403 { 404 union { 405 struct tpacket_hdr *h1; 406 struct tpacket2_hdr *h2; 407 void *raw; 408 } h; 409 410 h.raw = frame; 411 switch (po->tp_version) { 412 case TPACKET_V1: 413 h.h1->tp_status = status; 414 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 415 break; 416 case TPACKET_V2: 417 h.h2->tp_status = status; 418 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 419 break; 420 case TPACKET_V3: 421 default: 422 WARN(1, "TPACKET version not supported.\n"); 423 BUG(); 424 } 425 426 smp_wmb(); 427 } 428 429 static int __packet_get_status(struct packet_sock *po, void *frame) 430 { 431 union { 432 struct tpacket_hdr *h1; 433 struct tpacket2_hdr *h2; 434 void *raw; 435 } h; 436 437 smp_rmb(); 438 439 h.raw = frame; 440 switch (po->tp_version) { 441 case TPACKET_V1: 442 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 443 return h.h1->tp_status; 444 case TPACKET_V2: 445 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 446 return h.h2->tp_status; 447 case TPACKET_V3: 448 default: 449 WARN(1, "TPACKET version not supported.\n"); 450 BUG(); 451 return 0; 452 } 453 } 454 455 static void *packet_lookup_frame(struct packet_sock *po, 456 struct packet_ring_buffer *rb, 457 unsigned int position, 458 int status) 459 { 460 unsigned int pg_vec_pos, frame_offset; 461 union { 462 struct tpacket_hdr *h1; 463 struct tpacket2_hdr *h2; 464 void *raw; 465 } h; 466 467 pg_vec_pos = position / rb->frames_per_block; 468 frame_offset = position % rb->frames_per_block; 469 470 h.raw = rb->pg_vec[pg_vec_pos].buffer + 471 (frame_offset * rb->frame_size); 472 473 if (status != __packet_get_status(po, h.raw)) 474 return NULL; 475 476 return h.raw; 477 } 478 479 static void *packet_current_frame(struct packet_sock *po, 480 struct packet_ring_buffer *rb, 481 int status) 482 { 483 return packet_lookup_frame(po, rb, rb->head, status); 484 } 485 486 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 487 { 488 del_timer_sync(&pkc->retire_blk_timer); 489 } 490 491 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 492 int tx_ring, 493 struct sk_buff_head *rb_queue) 494 { 495 struct tpacket_kbdq_core *pkc; 496 497 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 498 499 spin_lock(&rb_queue->lock); 500 pkc->delete_blk_timer = 1; 501 spin_unlock(&rb_queue->lock); 502 503 prb_del_retire_blk_timer(pkc); 504 } 505 506 static void prb_init_blk_timer(struct packet_sock *po, 507 struct tpacket_kbdq_core *pkc, 508 void (*func) (unsigned long)) 509 { 510 init_timer(&pkc->retire_blk_timer); 511 pkc->retire_blk_timer.data = (long)po; 512 pkc->retire_blk_timer.function = func; 513 pkc->retire_blk_timer.expires = jiffies; 514 } 515 516 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 517 { 518 struct tpacket_kbdq_core *pkc; 519 520 if (tx_ring) 521 BUG(); 522 523 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 524 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 525 } 526 527 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 528 int blk_size_in_bytes) 529 { 530 struct net_device *dev; 531 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 532 struct ethtool_cmd ecmd; 533 int err; 534 u32 speed; 535 536 rtnl_lock(); 537 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 538 if (unlikely(!dev)) { 539 rtnl_unlock(); 540 return DEFAULT_PRB_RETIRE_TOV; 541 } 542 err = __ethtool_get_settings(dev, &ecmd); 543 speed = ethtool_cmd_speed(&ecmd); 544 rtnl_unlock(); 545 if (!err) { 546 /* 547 * If the link speed is so slow you don't really 548 * need to worry about perf anyways 549 */ 550 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 551 return DEFAULT_PRB_RETIRE_TOV; 552 } else { 553 msec = 1; 554 div = speed / 1000; 555 } 556 } 557 558 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 559 560 if (div) 561 mbits /= div; 562 563 tmo = mbits * msec; 564 565 if (div) 566 return tmo+1; 567 return tmo; 568 } 569 570 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 571 union tpacket_req_u *req_u) 572 { 573 p1->feature_req_word = req_u->req3.tp_feature_req_word; 574 } 575 576 static void init_prb_bdqc(struct packet_sock *po, 577 struct packet_ring_buffer *rb, 578 struct pgv *pg_vec, 579 union tpacket_req_u *req_u, int tx_ring) 580 { 581 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 582 struct tpacket_block_desc *pbd; 583 584 memset(p1, 0x0, sizeof(*p1)); 585 586 p1->knxt_seq_num = 1; 587 p1->pkbdq = pg_vec; 588 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 589 p1->pkblk_start = pg_vec[0].buffer; 590 p1->kblk_size = req_u->req3.tp_block_size; 591 p1->knum_blocks = req_u->req3.tp_block_nr; 592 p1->hdrlen = po->tp_hdrlen; 593 p1->version = po->tp_version; 594 p1->last_kactive_blk_num = 0; 595 po->stats_u.stats3.tp_freeze_q_cnt = 0; 596 if (req_u->req3.tp_retire_blk_tov) 597 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 598 else 599 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 600 req_u->req3.tp_block_size); 601 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 602 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 603 604 prb_init_ft_ops(p1, req_u); 605 prb_setup_retire_blk_timer(po, tx_ring); 606 prb_open_block(p1, pbd); 607 } 608 609 /* Do NOT update the last_blk_num first. 610 * Assumes sk_buff_head lock is held. 611 */ 612 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 613 { 614 mod_timer(&pkc->retire_blk_timer, 615 jiffies + pkc->tov_in_jiffies); 616 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 617 } 618 619 /* 620 * Timer logic: 621 * 1) We refresh the timer only when we open a block. 622 * By doing this we don't waste cycles refreshing the timer 623 * on packet-by-packet basis. 624 * 625 * With a 1MB block-size, on a 1Gbps line, it will take 626 * i) ~8 ms to fill a block + ii) memcpy etc. 627 * In this cut we are not accounting for the memcpy time. 628 * 629 * So, if the user sets the 'tmo' to 10ms then the timer 630 * will never fire while the block is still getting filled 631 * (which is what we want). However, the user could choose 632 * to close a block early and that's fine. 633 * 634 * But when the timer does fire, we check whether or not to refresh it. 635 * Since the tmo granularity is in msecs, it is not too expensive 636 * to refresh the timer, lets say every '8' msecs. 637 * Either the user can set the 'tmo' or we can derive it based on 638 * a) line-speed and b) block-size. 639 * prb_calc_retire_blk_tmo() calculates the tmo. 640 * 641 */ 642 static void prb_retire_rx_blk_timer_expired(unsigned long data) 643 { 644 struct packet_sock *po = (struct packet_sock *)data; 645 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 646 unsigned int frozen; 647 struct tpacket_block_desc *pbd; 648 649 spin_lock(&po->sk.sk_receive_queue.lock); 650 651 frozen = prb_queue_frozen(pkc); 652 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 653 654 if (unlikely(pkc->delete_blk_timer)) 655 goto out; 656 657 /* We only need to plug the race when the block is partially filled. 658 * tpacket_rcv: 659 * lock(); increment BLOCK_NUM_PKTS; unlock() 660 * copy_bits() is in progress ... 661 * timer fires on other cpu: 662 * we can't retire the current block because copy_bits 663 * is in progress. 664 * 665 */ 666 if (BLOCK_NUM_PKTS(pbd)) { 667 while (atomic_read(&pkc->blk_fill_in_prog)) { 668 /* Waiting for skb_copy_bits to finish... */ 669 cpu_relax(); 670 } 671 } 672 673 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 674 if (!frozen) { 675 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 676 if (!prb_dispatch_next_block(pkc, po)) 677 goto refresh_timer; 678 else 679 goto out; 680 } else { 681 /* Case 1. Queue was frozen because user-space was 682 * lagging behind. 683 */ 684 if (prb_curr_blk_in_use(pkc, pbd)) { 685 /* 686 * Ok, user-space is still behind. 687 * So just refresh the timer. 688 */ 689 goto refresh_timer; 690 } else { 691 /* Case 2. queue was frozen,user-space caught up, 692 * now the link went idle && the timer fired. 693 * We don't have a block to close.So we open this 694 * block and restart the timer. 695 * opening a block thaws the queue,restarts timer 696 * Thawing/timer-refresh is a side effect. 697 */ 698 prb_open_block(pkc, pbd); 699 goto out; 700 } 701 } 702 } 703 704 refresh_timer: 705 _prb_refresh_rx_retire_blk_timer(pkc); 706 707 out: 708 spin_unlock(&po->sk.sk_receive_queue.lock); 709 } 710 711 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 712 struct tpacket_block_desc *pbd1, __u32 status) 713 { 714 /* Flush everything minus the block header */ 715 716 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 717 u8 *start, *end; 718 719 start = (u8 *)pbd1; 720 721 /* Skip the block header(we know header WILL fit in 4K) */ 722 start += PAGE_SIZE; 723 724 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 725 for (; start < end; start += PAGE_SIZE) 726 flush_dcache_page(pgv_to_page(start)); 727 728 smp_wmb(); 729 #endif 730 731 /* Now update the block status. */ 732 733 BLOCK_STATUS(pbd1) = status; 734 735 /* Flush the block header */ 736 737 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 738 start = (u8 *)pbd1; 739 flush_dcache_page(pgv_to_page(start)); 740 741 smp_wmb(); 742 #endif 743 } 744 745 /* 746 * Side effect: 747 * 748 * 1) flush the block 749 * 2) Increment active_blk_num 750 * 751 * Note:We DONT refresh the timer on purpose. 752 * Because almost always the next block will be opened. 753 */ 754 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 755 struct tpacket_block_desc *pbd1, 756 struct packet_sock *po, unsigned int stat) 757 { 758 __u32 status = TP_STATUS_USER | stat; 759 760 struct tpacket3_hdr *last_pkt; 761 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 762 763 if (po->stats.tp_drops) 764 status |= TP_STATUS_LOSING; 765 766 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 767 last_pkt->tp_next_offset = 0; 768 769 /* Get the ts of the last pkt */ 770 if (BLOCK_NUM_PKTS(pbd1)) { 771 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 772 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 773 } else { 774 /* Ok, we tmo'd - so get the current time */ 775 struct timespec ts; 776 getnstimeofday(&ts); 777 h1->ts_last_pkt.ts_sec = ts.tv_sec; 778 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 779 } 780 781 smp_wmb(); 782 783 /* Flush the block */ 784 prb_flush_block(pkc1, pbd1, status); 785 786 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 787 } 788 789 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 790 { 791 pkc->reset_pending_on_curr_blk = 0; 792 } 793 794 /* 795 * Side effect of opening a block: 796 * 797 * 1) prb_queue is thawed. 798 * 2) retire_blk_timer is refreshed. 799 * 800 */ 801 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 802 struct tpacket_block_desc *pbd1) 803 { 804 struct timespec ts; 805 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 806 807 smp_rmb(); 808 809 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { 810 811 /* We could have just memset this but we will lose the 812 * flexibility of making the priv area sticky 813 */ 814 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 815 BLOCK_NUM_PKTS(pbd1) = 0; 816 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 817 getnstimeofday(&ts); 818 h1->ts_first_pkt.ts_sec = ts.tv_sec; 819 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 820 pkc1->pkblk_start = (char *)pbd1; 821 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 822 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 823 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 824 pbd1->version = pkc1->version; 825 pkc1->prev = pkc1->nxt_offset; 826 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 827 prb_thaw_queue(pkc1); 828 _prb_refresh_rx_retire_blk_timer(pkc1); 829 830 smp_wmb(); 831 832 return; 833 } 834 835 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", 836 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); 837 dump_stack(); 838 BUG(); 839 } 840 841 /* 842 * Queue freeze logic: 843 * 1) Assume tp_block_nr = 8 blocks. 844 * 2) At time 't0', user opens Rx ring. 845 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 846 * 4) user-space is either sleeping or processing block '0'. 847 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 848 * it will close block-7,loop around and try to fill block '0'. 849 * call-flow: 850 * __packet_lookup_frame_in_block 851 * prb_retire_current_block() 852 * prb_dispatch_next_block() 853 * |->(BLOCK_STATUS == USER) evaluates to true 854 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 855 * 6) Now there are two cases: 856 * 6.1) Link goes idle right after the queue is frozen. 857 * But remember, the last open_block() refreshed the timer. 858 * When this timer expires,it will refresh itself so that we can 859 * re-open block-0 in near future. 860 * 6.2) Link is busy and keeps on receiving packets. This is a simple 861 * case and __packet_lookup_frame_in_block will check if block-0 862 * is free and can now be re-used. 863 */ 864 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 865 struct packet_sock *po) 866 { 867 pkc->reset_pending_on_curr_blk = 1; 868 po->stats_u.stats3.tp_freeze_q_cnt++; 869 } 870 871 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 872 873 /* 874 * If the next block is free then we will dispatch it 875 * and return a good offset. 876 * Else, we will freeze the queue. 877 * So, caller must check the return value. 878 */ 879 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 880 struct packet_sock *po) 881 { 882 struct tpacket_block_desc *pbd; 883 884 smp_rmb(); 885 886 /* 1. Get current block num */ 887 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 888 889 /* 2. If this block is currently in_use then freeze the queue */ 890 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 891 prb_freeze_queue(pkc, po); 892 return NULL; 893 } 894 895 /* 896 * 3. 897 * open this block and return the offset where the first packet 898 * needs to get stored. 899 */ 900 prb_open_block(pkc, pbd); 901 return (void *)pkc->nxt_offset; 902 } 903 904 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 905 struct packet_sock *po, unsigned int status) 906 { 907 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 908 909 /* retire/close the current block */ 910 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 911 /* 912 * Plug the case where copy_bits() is in progress on 913 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 914 * have space to copy the pkt in the current block and 915 * called prb_retire_current_block() 916 * 917 * We don't need to worry about the TMO case because 918 * the timer-handler already handled this case. 919 */ 920 if (!(status & TP_STATUS_BLK_TMO)) { 921 while (atomic_read(&pkc->blk_fill_in_prog)) { 922 /* Waiting for skb_copy_bits to finish... */ 923 cpu_relax(); 924 } 925 } 926 prb_close_block(pkc, pbd, po, status); 927 return; 928 } 929 930 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); 931 dump_stack(); 932 BUG(); 933 } 934 935 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 936 struct tpacket_block_desc *pbd) 937 { 938 return TP_STATUS_USER & BLOCK_STATUS(pbd); 939 } 940 941 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 942 { 943 return pkc->reset_pending_on_curr_blk; 944 } 945 946 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 947 { 948 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 949 atomic_dec(&pkc->blk_fill_in_prog); 950 } 951 952 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 953 struct tpacket3_hdr *ppd) 954 { 955 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 956 } 957 958 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 959 struct tpacket3_hdr *ppd) 960 { 961 ppd->hv1.tp_rxhash = 0; 962 } 963 964 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 965 struct tpacket3_hdr *ppd) 966 { 967 if (vlan_tx_tag_present(pkc->skb)) { 968 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 969 ppd->tp_status = TP_STATUS_VLAN_VALID; 970 } else { 971 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0; 972 } 973 } 974 975 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 976 struct tpacket3_hdr *ppd) 977 { 978 prb_fill_vlan_info(pkc, ppd); 979 980 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 981 prb_fill_rxhash(pkc, ppd); 982 else 983 prb_clear_rxhash(pkc, ppd); 984 } 985 986 static void prb_fill_curr_block(char *curr, 987 struct tpacket_kbdq_core *pkc, 988 struct tpacket_block_desc *pbd, 989 unsigned int len) 990 { 991 struct tpacket3_hdr *ppd; 992 993 ppd = (struct tpacket3_hdr *)curr; 994 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 995 pkc->prev = curr; 996 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 997 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 998 BLOCK_NUM_PKTS(pbd) += 1; 999 atomic_inc(&pkc->blk_fill_in_prog); 1000 prb_run_all_ft_ops(pkc, ppd); 1001 } 1002 1003 /* Assumes caller has the sk->rx_queue.lock */ 1004 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1005 struct sk_buff *skb, 1006 int status, 1007 unsigned int len 1008 ) 1009 { 1010 struct tpacket_kbdq_core *pkc; 1011 struct tpacket_block_desc *pbd; 1012 char *curr, *end; 1013 1014 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1015 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1016 1017 /* Queue is frozen when user space is lagging behind */ 1018 if (prb_queue_frozen(pkc)) { 1019 /* 1020 * Check if that last block which caused the queue to freeze, 1021 * is still in_use by user-space. 1022 */ 1023 if (prb_curr_blk_in_use(pkc, pbd)) { 1024 /* Can't record this packet */ 1025 return NULL; 1026 } else { 1027 /* 1028 * Ok, the block was released by user-space. 1029 * Now let's open that block. 1030 * opening a block also thaws the queue. 1031 * Thawing is a side effect. 1032 */ 1033 prb_open_block(pkc, pbd); 1034 } 1035 } 1036 1037 smp_mb(); 1038 curr = pkc->nxt_offset; 1039 pkc->skb = skb; 1040 end = (char *)pbd + pkc->kblk_size; 1041 1042 /* first try the current block */ 1043 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1044 prb_fill_curr_block(curr, pkc, pbd, len); 1045 return (void *)curr; 1046 } 1047 1048 /* Ok, close the current block */ 1049 prb_retire_current_block(pkc, po, 0); 1050 1051 /* Now, try to dispatch the next block */ 1052 curr = (char *)prb_dispatch_next_block(pkc, po); 1053 if (curr) { 1054 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1055 prb_fill_curr_block(curr, pkc, pbd, len); 1056 return (void *)curr; 1057 } 1058 1059 /* 1060 * No free blocks are available.user_space hasn't caught up yet. 1061 * Queue was just frozen and now this packet will get dropped. 1062 */ 1063 return NULL; 1064 } 1065 1066 static void *packet_current_rx_frame(struct packet_sock *po, 1067 struct sk_buff *skb, 1068 int status, unsigned int len) 1069 { 1070 char *curr = NULL; 1071 switch (po->tp_version) { 1072 case TPACKET_V1: 1073 case TPACKET_V2: 1074 curr = packet_lookup_frame(po, &po->rx_ring, 1075 po->rx_ring.head, status); 1076 return curr; 1077 case TPACKET_V3: 1078 return __packet_lookup_frame_in_block(po, skb, status, len); 1079 default: 1080 WARN(1, "TPACKET version not supported\n"); 1081 BUG(); 1082 return NULL; 1083 } 1084 } 1085 1086 static void *prb_lookup_block(struct packet_sock *po, 1087 struct packet_ring_buffer *rb, 1088 unsigned int previous, 1089 int status) 1090 { 1091 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1092 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous); 1093 1094 if (status != BLOCK_STATUS(pbd)) 1095 return NULL; 1096 return pbd; 1097 } 1098 1099 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1100 { 1101 unsigned int prev; 1102 if (rb->prb_bdqc.kactive_blk_num) 1103 prev = rb->prb_bdqc.kactive_blk_num-1; 1104 else 1105 prev = rb->prb_bdqc.knum_blocks-1; 1106 return prev; 1107 } 1108 1109 /* Assumes caller has held the rx_queue.lock */ 1110 static void *__prb_previous_block(struct packet_sock *po, 1111 struct packet_ring_buffer *rb, 1112 int status) 1113 { 1114 unsigned int previous = prb_previous_blk_num(rb); 1115 return prb_lookup_block(po, rb, previous, status); 1116 } 1117 1118 static void *packet_previous_rx_frame(struct packet_sock *po, 1119 struct packet_ring_buffer *rb, 1120 int status) 1121 { 1122 if (po->tp_version <= TPACKET_V2) 1123 return packet_previous_frame(po, rb, status); 1124 1125 return __prb_previous_block(po, rb, status); 1126 } 1127 1128 static void packet_increment_rx_head(struct packet_sock *po, 1129 struct packet_ring_buffer *rb) 1130 { 1131 switch (po->tp_version) { 1132 case TPACKET_V1: 1133 case TPACKET_V2: 1134 return packet_increment_head(rb); 1135 case TPACKET_V3: 1136 default: 1137 WARN(1, "TPACKET version not supported.\n"); 1138 BUG(); 1139 return; 1140 } 1141 } 1142 1143 static void *packet_previous_frame(struct packet_sock *po, 1144 struct packet_ring_buffer *rb, 1145 int status) 1146 { 1147 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1148 return packet_lookup_frame(po, rb, previous, status); 1149 } 1150 1151 static void packet_increment_head(struct packet_ring_buffer *buff) 1152 { 1153 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1154 } 1155 1156 static void packet_sock_destruct(struct sock *sk) 1157 { 1158 skb_queue_purge(&sk->sk_error_queue); 1159 1160 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1161 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1162 1163 if (!sock_flag(sk, SOCK_DEAD)) { 1164 pr_err("Attempt to release alive packet socket: %p\n", sk); 1165 return; 1166 } 1167 1168 sk_refcnt_debug_dec(sk); 1169 } 1170 1171 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1172 { 1173 int x = atomic_read(&f->rr_cur) + 1; 1174 1175 if (x >= num) 1176 x = 0; 1177 1178 return x; 1179 } 1180 1181 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1182 { 1183 u32 idx, hash = skb->rxhash; 1184 1185 idx = ((u64)hash * num) >> 32; 1186 1187 return f->arr[idx]; 1188 } 1189 1190 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1191 { 1192 int cur, old; 1193 1194 cur = atomic_read(&f->rr_cur); 1195 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1196 fanout_rr_next(f, num))) != cur) 1197 cur = old; 1198 return f->arr[cur]; 1199 } 1200 1201 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1202 { 1203 unsigned int cpu = smp_processor_id(); 1204 1205 return f->arr[cpu % num]; 1206 } 1207 1208 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1209 struct packet_type *pt, struct net_device *orig_dev) 1210 { 1211 struct packet_fanout *f = pt->af_packet_priv; 1212 unsigned int num = f->num_members; 1213 struct packet_sock *po; 1214 struct sock *sk; 1215 1216 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1217 !num) { 1218 kfree_skb(skb); 1219 return 0; 1220 } 1221 1222 switch (f->type) { 1223 case PACKET_FANOUT_HASH: 1224 default: 1225 if (f->defrag) { 1226 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1227 if (!skb) 1228 return 0; 1229 } 1230 skb_get_rxhash(skb); 1231 sk = fanout_demux_hash(f, skb, num); 1232 break; 1233 case PACKET_FANOUT_LB: 1234 sk = fanout_demux_lb(f, skb, num); 1235 break; 1236 case PACKET_FANOUT_CPU: 1237 sk = fanout_demux_cpu(f, skb, num); 1238 break; 1239 } 1240 1241 po = pkt_sk(sk); 1242 1243 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1244 } 1245 1246 static DEFINE_MUTEX(fanout_mutex); 1247 static LIST_HEAD(fanout_list); 1248 1249 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1250 { 1251 struct packet_fanout *f = po->fanout; 1252 1253 spin_lock(&f->lock); 1254 f->arr[f->num_members] = sk; 1255 smp_wmb(); 1256 f->num_members++; 1257 spin_unlock(&f->lock); 1258 } 1259 1260 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1261 { 1262 struct packet_fanout *f = po->fanout; 1263 int i; 1264 1265 spin_lock(&f->lock); 1266 for (i = 0; i < f->num_members; i++) { 1267 if (f->arr[i] == sk) 1268 break; 1269 } 1270 BUG_ON(i >= f->num_members); 1271 f->arr[i] = f->arr[f->num_members - 1]; 1272 f->num_members--; 1273 spin_unlock(&f->lock); 1274 } 1275 1276 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk) 1277 { 1278 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) 1279 return true; 1280 1281 return false; 1282 } 1283 1284 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1285 { 1286 struct packet_sock *po = pkt_sk(sk); 1287 struct packet_fanout *f, *match; 1288 u8 type = type_flags & 0xff; 1289 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; 1290 int err; 1291 1292 switch (type) { 1293 case PACKET_FANOUT_HASH: 1294 case PACKET_FANOUT_LB: 1295 case PACKET_FANOUT_CPU: 1296 break; 1297 default: 1298 return -EINVAL; 1299 } 1300 1301 if (!po->running) 1302 return -EINVAL; 1303 1304 if (po->fanout) 1305 return -EALREADY; 1306 1307 mutex_lock(&fanout_mutex); 1308 match = NULL; 1309 list_for_each_entry(f, &fanout_list, list) { 1310 if (f->id == id && 1311 read_pnet(&f->net) == sock_net(sk)) { 1312 match = f; 1313 break; 1314 } 1315 } 1316 err = -EINVAL; 1317 if (match && match->defrag != defrag) 1318 goto out; 1319 if (!match) { 1320 err = -ENOMEM; 1321 match = kzalloc(sizeof(*match), GFP_KERNEL); 1322 if (!match) 1323 goto out; 1324 write_pnet(&match->net, sock_net(sk)); 1325 match->id = id; 1326 match->type = type; 1327 match->defrag = defrag; 1328 atomic_set(&match->rr_cur, 0); 1329 INIT_LIST_HEAD(&match->list); 1330 spin_lock_init(&match->lock); 1331 atomic_set(&match->sk_ref, 0); 1332 match->prot_hook.type = po->prot_hook.type; 1333 match->prot_hook.dev = po->prot_hook.dev; 1334 match->prot_hook.func = packet_rcv_fanout; 1335 match->prot_hook.af_packet_priv = match; 1336 match->prot_hook.id_match = match_fanout_group; 1337 dev_add_pack(&match->prot_hook); 1338 list_add(&match->list, &fanout_list); 1339 } 1340 err = -EINVAL; 1341 if (match->type == type && 1342 match->prot_hook.type == po->prot_hook.type && 1343 match->prot_hook.dev == po->prot_hook.dev) { 1344 err = -ENOSPC; 1345 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1346 __dev_remove_pack(&po->prot_hook); 1347 po->fanout = match; 1348 atomic_inc(&match->sk_ref); 1349 __fanout_link(sk, po); 1350 err = 0; 1351 } 1352 } 1353 out: 1354 mutex_unlock(&fanout_mutex); 1355 return err; 1356 } 1357 1358 static void fanout_release(struct sock *sk) 1359 { 1360 struct packet_sock *po = pkt_sk(sk); 1361 struct packet_fanout *f; 1362 1363 f = po->fanout; 1364 if (!f) 1365 return; 1366 1367 po->fanout = NULL; 1368 1369 mutex_lock(&fanout_mutex); 1370 if (atomic_dec_and_test(&f->sk_ref)) { 1371 list_del(&f->list); 1372 dev_remove_pack(&f->prot_hook); 1373 kfree(f); 1374 } 1375 mutex_unlock(&fanout_mutex); 1376 } 1377 1378 static const struct proto_ops packet_ops; 1379 1380 static const struct proto_ops packet_ops_spkt; 1381 1382 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1383 struct packet_type *pt, struct net_device *orig_dev) 1384 { 1385 struct sock *sk; 1386 struct sockaddr_pkt *spkt; 1387 1388 /* 1389 * When we registered the protocol we saved the socket in the data 1390 * field for just this event. 1391 */ 1392 1393 sk = pt->af_packet_priv; 1394 1395 /* 1396 * Yank back the headers [hope the device set this 1397 * right or kerboom...] 1398 * 1399 * Incoming packets have ll header pulled, 1400 * push it back. 1401 * 1402 * For outgoing ones skb->data == skb_mac_header(skb) 1403 * so that this procedure is noop. 1404 */ 1405 1406 if (skb->pkt_type == PACKET_LOOPBACK) 1407 goto out; 1408 1409 if (!net_eq(dev_net(dev), sock_net(sk))) 1410 goto out; 1411 1412 skb = skb_share_check(skb, GFP_ATOMIC); 1413 if (skb == NULL) 1414 goto oom; 1415 1416 /* drop any routing info */ 1417 skb_dst_drop(skb); 1418 1419 /* drop conntrack reference */ 1420 nf_reset(skb); 1421 1422 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1423 1424 skb_push(skb, skb->data - skb_mac_header(skb)); 1425 1426 /* 1427 * The SOCK_PACKET socket receives _all_ frames. 1428 */ 1429 1430 spkt->spkt_family = dev->type; 1431 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1432 spkt->spkt_protocol = skb->protocol; 1433 1434 /* 1435 * Charge the memory to the socket. This is done specifically 1436 * to prevent sockets using all the memory up. 1437 */ 1438 1439 if (sock_queue_rcv_skb(sk, skb) == 0) 1440 return 0; 1441 1442 out: 1443 kfree_skb(skb); 1444 oom: 1445 return 0; 1446 } 1447 1448 1449 /* 1450 * Output a raw packet to a device layer. This bypasses all the other 1451 * protocol layers and you must therefore supply it with a complete frame 1452 */ 1453 1454 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1455 struct msghdr *msg, size_t len) 1456 { 1457 struct sock *sk = sock->sk; 1458 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1459 struct sk_buff *skb = NULL; 1460 struct net_device *dev; 1461 __be16 proto = 0; 1462 int err; 1463 int extra_len = 0; 1464 1465 /* 1466 * Get and verify the address. 1467 */ 1468 1469 if (saddr) { 1470 if (msg->msg_namelen < sizeof(struct sockaddr)) 1471 return -EINVAL; 1472 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1473 proto = saddr->spkt_protocol; 1474 } else 1475 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1476 1477 /* 1478 * Find the device first to size check it 1479 */ 1480 1481 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1482 retry: 1483 rcu_read_lock(); 1484 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1485 err = -ENODEV; 1486 if (dev == NULL) 1487 goto out_unlock; 1488 1489 err = -ENETDOWN; 1490 if (!(dev->flags & IFF_UP)) 1491 goto out_unlock; 1492 1493 /* 1494 * You may not queue a frame bigger than the mtu. This is the lowest level 1495 * raw protocol and you must do your own fragmentation at this level. 1496 */ 1497 1498 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1499 if (!netif_supports_nofcs(dev)) { 1500 err = -EPROTONOSUPPORT; 1501 goto out_unlock; 1502 } 1503 extra_len = 4; /* We're doing our own CRC */ 1504 } 1505 1506 err = -EMSGSIZE; 1507 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1508 goto out_unlock; 1509 1510 if (!skb) { 1511 size_t reserved = LL_RESERVED_SPACE(dev); 1512 int tlen = dev->needed_tailroom; 1513 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1514 1515 rcu_read_unlock(); 1516 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1517 if (skb == NULL) 1518 return -ENOBUFS; 1519 /* FIXME: Save some space for broken drivers that write a hard 1520 * header at transmission time by themselves. PPP is the notable 1521 * one here. This should really be fixed at the driver level. 1522 */ 1523 skb_reserve(skb, reserved); 1524 skb_reset_network_header(skb); 1525 1526 /* Try to align data part correctly */ 1527 if (hhlen) { 1528 skb->data -= hhlen; 1529 skb->tail -= hhlen; 1530 if (len < hhlen) 1531 skb_reset_network_header(skb); 1532 } 1533 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1534 if (err) 1535 goto out_free; 1536 goto retry; 1537 } 1538 1539 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1540 /* Earlier code assumed this would be a VLAN pkt, 1541 * double-check this now that we have the actual 1542 * packet in hand. 1543 */ 1544 struct ethhdr *ehdr; 1545 skb_reset_mac_header(skb); 1546 ehdr = eth_hdr(skb); 1547 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1548 err = -EMSGSIZE; 1549 goto out_unlock; 1550 } 1551 } 1552 1553 skb->protocol = proto; 1554 skb->dev = dev; 1555 skb->priority = sk->sk_priority; 1556 skb->mark = sk->sk_mark; 1557 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1558 if (err < 0) 1559 goto out_unlock; 1560 1561 if (unlikely(extra_len == 4)) 1562 skb->no_fcs = 1; 1563 1564 dev_queue_xmit(skb); 1565 rcu_read_unlock(); 1566 return len; 1567 1568 out_unlock: 1569 rcu_read_unlock(); 1570 out_free: 1571 kfree_skb(skb); 1572 return err; 1573 } 1574 1575 static unsigned int run_filter(const struct sk_buff *skb, 1576 const struct sock *sk, 1577 unsigned int res) 1578 { 1579 struct sk_filter *filter; 1580 1581 rcu_read_lock(); 1582 filter = rcu_dereference(sk->sk_filter); 1583 if (filter != NULL) 1584 res = SK_RUN_FILTER(filter, skb); 1585 rcu_read_unlock(); 1586 1587 return res; 1588 } 1589 1590 /* 1591 * This function makes lazy skb cloning in hope that most of packets 1592 * are discarded by BPF. 1593 * 1594 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1595 * and skb->cb are mangled. It works because (and until) packets 1596 * falling here are owned by current CPU. Output packets are cloned 1597 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1598 * sequencially, so that if we return skb to original state on exit, 1599 * we will not harm anyone. 1600 */ 1601 1602 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1603 struct packet_type *pt, struct net_device *orig_dev) 1604 { 1605 struct sock *sk; 1606 struct sockaddr_ll *sll; 1607 struct packet_sock *po; 1608 u8 *skb_head = skb->data; 1609 int skb_len = skb->len; 1610 unsigned int snaplen, res; 1611 1612 if (skb->pkt_type == PACKET_LOOPBACK) 1613 goto drop; 1614 1615 sk = pt->af_packet_priv; 1616 po = pkt_sk(sk); 1617 1618 if (!net_eq(dev_net(dev), sock_net(sk))) 1619 goto drop; 1620 1621 skb->dev = dev; 1622 1623 if (dev->header_ops) { 1624 /* The device has an explicit notion of ll header, 1625 * exported to higher levels. 1626 * 1627 * Otherwise, the device hides details of its frame 1628 * structure, so that corresponding packet head is 1629 * never delivered to user. 1630 */ 1631 if (sk->sk_type != SOCK_DGRAM) 1632 skb_push(skb, skb->data - skb_mac_header(skb)); 1633 else if (skb->pkt_type == PACKET_OUTGOING) { 1634 /* Special case: outgoing packets have ll header at head */ 1635 skb_pull(skb, skb_network_offset(skb)); 1636 } 1637 } 1638 1639 snaplen = skb->len; 1640 1641 res = run_filter(skb, sk, snaplen); 1642 if (!res) 1643 goto drop_n_restore; 1644 if (snaplen > res) 1645 snaplen = res; 1646 1647 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1648 goto drop_n_acct; 1649 1650 if (skb_shared(skb)) { 1651 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1652 if (nskb == NULL) 1653 goto drop_n_acct; 1654 1655 if (skb_head != skb->data) { 1656 skb->data = skb_head; 1657 skb->len = skb_len; 1658 } 1659 consume_skb(skb); 1660 skb = nskb; 1661 } 1662 1663 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1664 sizeof(skb->cb)); 1665 1666 sll = &PACKET_SKB_CB(skb)->sa.ll; 1667 sll->sll_family = AF_PACKET; 1668 sll->sll_hatype = dev->type; 1669 sll->sll_protocol = skb->protocol; 1670 sll->sll_pkttype = skb->pkt_type; 1671 if (unlikely(po->origdev)) 1672 sll->sll_ifindex = orig_dev->ifindex; 1673 else 1674 sll->sll_ifindex = dev->ifindex; 1675 1676 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1677 1678 PACKET_SKB_CB(skb)->origlen = skb->len; 1679 1680 if (pskb_trim(skb, snaplen)) 1681 goto drop_n_acct; 1682 1683 skb_set_owner_r(skb, sk); 1684 skb->dev = NULL; 1685 skb_dst_drop(skb); 1686 1687 /* drop conntrack reference */ 1688 nf_reset(skb); 1689 1690 spin_lock(&sk->sk_receive_queue.lock); 1691 po->stats.tp_packets++; 1692 skb->dropcount = atomic_read(&sk->sk_drops); 1693 __skb_queue_tail(&sk->sk_receive_queue, skb); 1694 spin_unlock(&sk->sk_receive_queue.lock); 1695 sk->sk_data_ready(sk, skb->len); 1696 return 0; 1697 1698 drop_n_acct: 1699 spin_lock(&sk->sk_receive_queue.lock); 1700 po->stats.tp_drops++; 1701 atomic_inc(&sk->sk_drops); 1702 spin_unlock(&sk->sk_receive_queue.lock); 1703 1704 drop_n_restore: 1705 if (skb_head != skb->data && skb_shared(skb)) { 1706 skb->data = skb_head; 1707 skb->len = skb_len; 1708 } 1709 drop: 1710 consume_skb(skb); 1711 return 0; 1712 } 1713 1714 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1715 struct packet_type *pt, struct net_device *orig_dev) 1716 { 1717 struct sock *sk; 1718 struct packet_sock *po; 1719 struct sockaddr_ll *sll; 1720 union { 1721 struct tpacket_hdr *h1; 1722 struct tpacket2_hdr *h2; 1723 struct tpacket3_hdr *h3; 1724 void *raw; 1725 } h; 1726 u8 *skb_head = skb->data; 1727 int skb_len = skb->len; 1728 unsigned int snaplen, res; 1729 unsigned long status = TP_STATUS_USER; 1730 unsigned short macoff, netoff, hdrlen; 1731 struct sk_buff *copy_skb = NULL; 1732 struct timeval tv; 1733 struct timespec ts; 1734 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 1735 1736 if (skb->pkt_type == PACKET_LOOPBACK) 1737 goto drop; 1738 1739 sk = pt->af_packet_priv; 1740 po = pkt_sk(sk); 1741 1742 if (!net_eq(dev_net(dev), sock_net(sk))) 1743 goto drop; 1744 1745 if (dev->header_ops) { 1746 if (sk->sk_type != SOCK_DGRAM) 1747 skb_push(skb, skb->data - skb_mac_header(skb)); 1748 else if (skb->pkt_type == PACKET_OUTGOING) { 1749 /* Special case: outgoing packets have ll header at head */ 1750 skb_pull(skb, skb_network_offset(skb)); 1751 } 1752 } 1753 1754 if (skb->ip_summed == CHECKSUM_PARTIAL) 1755 status |= TP_STATUS_CSUMNOTREADY; 1756 1757 snaplen = skb->len; 1758 1759 res = run_filter(skb, sk, snaplen); 1760 if (!res) 1761 goto drop_n_restore; 1762 if (snaplen > res) 1763 snaplen = res; 1764 1765 if (sk->sk_type == SOCK_DGRAM) { 1766 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1767 po->tp_reserve; 1768 } else { 1769 unsigned int maclen = skb_network_offset(skb); 1770 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1771 (maclen < 16 ? 16 : maclen)) + 1772 po->tp_reserve; 1773 macoff = netoff - maclen; 1774 } 1775 if (po->tp_version <= TPACKET_V2) { 1776 if (macoff + snaplen > po->rx_ring.frame_size) { 1777 if (po->copy_thresh && 1778 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1779 if (skb_shared(skb)) { 1780 copy_skb = skb_clone(skb, GFP_ATOMIC); 1781 } else { 1782 copy_skb = skb_get(skb); 1783 skb_head = skb->data; 1784 } 1785 if (copy_skb) 1786 skb_set_owner_r(copy_skb, sk); 1787 } 1788 snaplen = po->rx_ring.frame_size - macoff; 1789 if ((int)snaplen < 0) 1790 snaplen = 0; 1791 } 1792 } 1793 spin_lock(&sk->sk_receive_queue.lock); 1794 h.raw = packet_current_rx_frame(po, skb, 1795 TP_STATUS_KERNEL, (macoff+snaplen)); 1796 if (!h.raw) 1797 goto ring_is_full; 1798 if (po->tp_version <= TPACKET_V2) { 1799 packet_increment_rx_head(po, &po->rx_ring); 1800 /* 1801 * LOSING will be reported till you read the stats, 1802 * because it's COR - Clear On Read. 1803 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1804 * at packet level. 1805 */ 1806 if (po->stats.tp_drops) 1807 status |= TP_STATUS_LOSING; 1808 } 1809 po->stats.tp_packets++; 1810 if (copy_skb) { 1811 status |= TP_STATUS_COPY; 1812 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1813 } 1814 spin_unlock(&sk->sk_receive_queue.lock); 1815 1816 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1817 1818 switch (po->tp_version) { 1819 case TPACKET_V1: 1820 h.h1->tp_len = skb->len; 1821 h.h1->tp_snaplen = snaplen; 1822 h.h1->tp_mac = macoff; 1823 h.h1->tp_net = netoff; 1824 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1825 && shhwtstamps->syststamp.tv64) 1826 tv = ktime_to_timeval(shhwtstamps->syststamp); 1827 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1828 && shhwtstamps->hwtstamp.tv64) 1829 tv = ktime_to_timeval(shhwtstamps->hwtstamp); 1830 else if (skb->tstamp.tv64) 1831 tv = ktime_to_timeval(skb->tstamp); 1832 else 1833 do_gettimeofday(&tv); 1834 h.h1->tp_sec = tv.tv_sec; 1835 h.h1->tp_usec = tv.tv_usec; 1836 hdrlen = sizeof(*h.h1); 1837 break; 1838 case TPACKET_V2: 1839 h.h2->tp_len = skb->len; 1840 h.h2->tp_snaplen = snaplen; 1841 h.h2->tp_mac = macoff; 1842 h.h2->tp_net = netoff; 1843 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1844 && shhwtstamps->syststamp.tv64) 1845 ts = ktime_to_timespec(shhwtstamps->syststamp); 1846 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1847 && shhwtstamps->hwtstamp.tv64) 1848 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1849 else if (skb->tstamp.tv64) 1850 ts = ktime_to_timespec(skb->tstamp); 1851 else 1852 getnstimeofday(&ts); 1853 h.h2->tp_sec = ts.tv_sec; 1854 h.h2->tp_nsec = ts.tv_nsec; 1855 if (vlan_tx_tag_present(skb)) { 1856 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1857 status |= TP_STATUS_VLAN_VALID; 1858 } else { 1859 h.h2->tp_vlan_tci = 0; 1860 } 1861 h.h2->tp_padding = 0; 1862 hdrlen = sizeof(*h.h2); 1863 break; 1864 case TPACKET_V3: 1865 /* tp_nxt_offset,vlan are already populated above. 1866 * So DONT clear those fields here 1867 */ 1868 h.h3->tp_status |= status; 1869 h.h3->tp_len = skb->len; 1870 h.h3->tp_snaplen = snaplen; 1871 h.h3->tp_mac = macoff; 1872 h.h3->tp_net = netoff; 1873 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1874 && shhwtstamps->syststamp.tv64) 1875 ts = ktime_to_timespec(shhwtstamps->syststamp); 1876 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1877 && shhwtstamps->hwtstamp.tv64) 1878 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1879 else if (skb->tstamp.tv64) 1880 ts = ktime_to_timespec(skb->tstamp); 1881 else 1882 getnstimeofday(&ts); 1883 h.h3->tp_sec = ts.tv_sec; 1884 h.h3->tp_nsec = ts.tv_nsec; 1885 hdrlen = sizeof(*h.h3); 1886 break; 1887 default: 1888 BUG(); 1889 } 1890 1891 sll = h.raw + TPACKET_ALIGN(hdrlen); 1892 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1893 sll->sll_family = AF_PACKET; 1894 sll->sll_hatype = dev->type; 1895 sll->sll_protocol = skb->protocol; 1896 sll->sll_pkttype = skb->pkt_type; 1897 if (unlikely(po->origdev)) 1898 sll->sll_ifindex = orig_dev->ifindex; 1899 else 1900 sll->sll_ifindex = dev->ifindex; 1901 1902 smp_mb(); 1903 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1904 { 1905 u8 *start, *end; 1906 1907 if (po->tp_version <= TPACKET_V2) { 1908 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1909 + macoff + snaplen); 1910 for (start = h.raw; start < end; start += PAGE_SIZE) 1911 flush_dcache_page(pgv_to_page(start)); 1912 } 1913 smp_wmb(); 1914 } 1915 #endif 1916 if (po->tp_version <= TPACKET_V2) 1917 __packet_set_status(po, h.raw, status); 1918 else 1919 prb_clear_blk_fill_status(&po->rx_ring); 1920 1921 sk->sk_data_ready(sk, 0); 1922 1923 drop_n_restore: 1924 if (skb_head != skb->data && skb_shared(skb)) { 1925 skb->data = skb_head; 1926 skb->len = skb_len; 1927 } 1928 drop: 1929 kfree_skb(skb); 1930 return 0; 1931 1932 ring_is_full: 1933 po->stats.tp_drops++; 1934 spin_unlock(&sk->sk_receive_queue.lock); 1935 1936 sk->sk_data_ready(sk, 0); 1937 kfree_skb(copy_skb); 1938 goto drop_n_restore; 1939 } 1940 1941 static void tpacket_destruct_skb(struct sk_buff *skb) 1942 { 1943 struct packet_sock *po = pkt_sk(skb->sk); 1944 void *ph; 1945 1946 if (likely(po->tx_ring.pg_vec)) { 1947 ph = skb_shinfo(skb)->destructor_arg; 1948 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1949 atomic_dec(&po->tx_ring.pending); 1950 __packet_set_status(po, ph, TP_STATUS_AVAILABLE); 1951 } 1952 1953 sock_wfree(skb); 1954 } 1955 1956 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1957 void *frame, struct net_device *dev, int size_max, 1958 __be16 proto, unsigned char *addr, int hlen) 1959 { 1960 union { 1961 struct tpacket_hdr *h1; 1962 struct tpacket2_hdr *h2; 1963 void *raw; 1964 } ph; 1965 int to_write, offset, len, tp_len, nr_frags, len_max; 1966 struct socket *sock = po->sk.sk_socket; 1967 struct page *page; 1968 void *data; 1969 int err; 1970 1971 ph.raw = frame; 1972 1973 skb->protocol = proto; 1974 skb->dev = dev; 1975 skb->priority = po->sk.sk_priority; 1976 skb->mark = po->sk.sk_mark; 1977 skb_shinfo(skb)->destructor_arg = ph.raw; 1978 1979 switch (po->tp_version) { 1980 case TPACKET_V2: 1981 tp_len = ph.h2->tp_len; 1982 break; 1983 default: 1984 tp_len = ph.h1->tp_len; 1985 break; 1986 } 1987 if (unlikely(tp_len > size_max)) { 1988 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1989 return -EMSGSIZE; 1990 } 1991 1992 skb_reserve(skb, hlen); 1993 skb_reset_network_header(skb); 1994 1995 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1996 to_write = tp_len; 1997 1998 if (sock->type == SOCK_DGRAM) { 1999 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2000 NULL, tp_len); 2001 if (unlikely(err < 0)) 2002 return -EINVAL; 2003 } else if (dev->hard_header_len) { 2004 /* net device doesn't like empty head */ 2005 if (unlikely(tp_len <= dev->hard_header_len)) { 2006 pr_err("packet size is too short (%d < %d)\n", 2007 tp_len, dev->hard_header_len); 2008 return -EINVAL; 2009 } 2010 2011 skb_push(skb, dev->hard_header_len); 2012 err = skb_store_bits(skb, 0, data, 2013 dev->hard_header_len); 2014 if (unlikely(err)) 2015 return err; 2016 2017 data += dev->hard_header_len; 2018 to_write -= dev->hard_header_len; 2019 } 2020 2021 err = -EFAULT; 2022 offset = offset_in_page(data); 2023 len_max = PAGE_SIZE - offset; 2024 len = ((to_write > len_max) ? len_max : to_write); 2025 2026 skb->data_len = to_write; 2027 skb->len += to_write; 2028 skb->truesize += to_write; 2029 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2030 2031 while (likely(to_write)) { 2032 nr_frags = skb_shinfo(skb)->nr_frags; 2033 2034 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2035 pr_err("Packet exceed the number of skb frags(%lu)\n", 2036 MAX_SKB_FRAGS); 2037 return -EFAULT; 2038 } 2039 2040 page = pgv_to_page(data); 2041 data += len; 2042 flush_dcache_page(page); 2043 get_page(page); 2044 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2045 to_write -= len; 2046 offset = 0; 2047 len_max = PAGE_SIZE; 2048 len = ((to_write > len_max) ? len_max : to_write); 2049 } 2050 2051 return tp_len; 2052 } 2053 2054 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2055 { 2056 struct sk_buff *skb; 2057 struct net_device *dev; 2058 __be16 proto; 2059 bool need_rls_dev = false; 2060 int err, reserve = 0; 2061 void *ph; 2062 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2063 int tp_len, size_max; 2064 unsigned char *addr; 2065 int len_sum = 0; 2066 int status = 0; 2067 int hlen, tlen; 2068 2069 mutex_lock(&po->pg_vec_lock); 2070 2071 err = -EBUSY; 2072 if (saddr == NULL) { 2073 dev = po->prot_hook.dev; 2074 proto = po->num; 2075 addr = NULL; 2076 } else { 2077 err = -EINVAL; 2078 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2079 goto out; 2080 if (msg->msg_namelen < (saddr->sll_halen 2081 + offsetof(struct sockaddr_ll, 2082 sll_addr))) 2083 goto out; 2084 proto = saddr->sll_protocol; 2085 addr = saddr->sll_addr; 2086 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2087 need_rls_dev = true; 2088 } 2089 2090 err = -ENXIO; 2091 if (unlikely(dev == NULL)) 2092 goto out; 2093 2094 reserve = dev->hard_header_len; 2095 2096 err = -ENETDOWN; 2097 if (unlikely(!(dev->flags & IFF_UP))) 2098 goto out_put; 2099 2100 size_max = po->tx_ring.frame_size 2101 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2102 2103 if (size_max > dev->mtu + reserve) 2104 size_max = dev->mtu + reserve; 2105 2106 do { 2107 ph = packet_current_frame(po, &po->tx_ring, 2108 TP_STATUS_SEND_REQUEST); 2109 2110 if (unlikely(ph == NULL)) { 2111 schedule(); 2112 continue; 2113 } 2114 2115 status = TP_STATUS_SEND_REQUEST; 2116 hlen = LL_RESERVED_SPACE(dev); 2117 tlen = dev->needed_tailroom; 2118 skb = sock_alloc_send_skb(&po->sk, 2119 hlen + tlen + sizeof(struct sockaddr_ll), 2120 0, &err); 2121 2122 if (unlikely(skb == NULL)) 2123 goto out_status; 2124 2125 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2126 addr, hlen); 2127 2128 if (unlikely(tp_len < 0)) { 2129 if (po->tp_loss) { 2130 __packet_set_status(po, ph, 2131 TP_STATUS_AVAILABLE); 2132 packet_increment_head(&po->tx_ring); 2133 kfree_skb(skb); 2134 continue; 2135 } else { 2136 status = TP_STATUS_WRONG_FORMAT; 2137 err = tp_len; 2138 goto out_status; 2139 } 2140 } 2141 2142 skb->destructor = tpacket_destruct_skb; 2143 __packet_set_status(po, ph, TP_STATUS_SENDING); 2144 atomic_inc(&po->tx_ring.pending); 2145 2146 status = TP_STATUS_SEND_REQUEST; 2147 err = dev_queue_xmit(skb); 2148 if (unlikely(err > 0)) { 2149 err = net_xmit_errno(err); 2150 if (err && __packet_get_status(po, ph) == 2151 TP_STATUS_AVAILABLE) { 2152 /* skb was destructed already */ 2153 skb = NULL; 2154 goto out_status; 2155 } 2156 /* 2157 * skb was dropped but not destructed yet; 2158 * let's treat it like congestion or err < 0 2159 */ 2160 err = 0; 2161 } 2162 packet_increment_head(&po->tx_ring); 2163 len_sum += tp_len; 2164 } while (likely((ph != NULL) || 2165 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2166 (atomic_read(&po->tx_ring.pending)))) 2167 ); 2168 2169 err = len_sum; 2170 goto out_put; 2171 2172 out_status: 2173 __packet_set_status(po, ph, status); 2174 kfree_skb(skb); 2175 out_put: 2176 if (need_rls_dev) 2177 dev_put(dev); 2178 out: 2179 mutex_unlock(&po->pg_vec_lock); 2180 return err; 2181 } 2182 2183 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2184 size_t reserve, size_t len, 2185 size_t linear, int noblock, 2186 int *err) 2187 { 2188 struct sk_buff *skb; 2189 2190 /* Under a page? Don't bother with paged skb. */ 2191 if (prepad + len < PAGE_SIZE || !linear) 2192 linear = len; 2193 2194 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2195 err); 2196 if (!skb) 2197 return NULL; 2198 2199 skb_reserve(skb, reserve); 2200 skb_put(skb, linear); 2201 skb->data_len = len - linear; 2202 skb->len += len - linear; 2203 2204 return skb; 2205 } 2206 2207 static int packet_snd(struct socket *sock, 2208 struct msghdr *msg, size_t len) 2209 { 2210 struct sock *sk = sock->sk; 2211 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2212 struct sk_buff *skb; 2213 struct net_device *dev; 2214 __be16 proto; 2215 bool need_rls_dev = false; 2216 unsigned char *addr; 2217 int err, reserve = 0; 2218 struct virtio_net_hdr vnet_hdr = { 0 }; 2219 int offset = 0; 2220 int vnet_hdr_len; 2221 struct packet_sock *po = pkt_sk(sk); 2222 unsigned short gso_type = 0; 2223 int hlen, tlen; 2224 int extra_len = 0; 2225 2226 /* 2227 * Get and verify the address. 2228 */ 2229 2230 if (saddr == NULL) { 2231 dev = po->prot_hook.dev; 2232 proto = po->num; 2233 addr = NULL; 2234 } else { 2235 err = -EINVAL; 2236 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2237 goto out; 2238 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2239 goto out; 2240 proto = saddr->sll_protocol; 2241 addr = saddr->sll_addr; 2242 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2243 need_rls_dev = true; 2244 } 2245 2246 err = -ENXIO; 2247 if (dev == NULL) 2248 goto out_unlock; 2249 if (sock->type == SOCK_RAW) 2250 reserve = dev->hard_header_len; 2251 2252 err = -ENETDOWN; 2253 if (!(dev->flags & IFF_UP)) 2254 goto out_unlock; 2255 2256 if (po->has_vnet_hdr) { 2257 vnet_hdr_len = sizeof(vnet_hdr); 2258 2259 err = -EINVAL; 2260 if (len < vnet_hdr_len) 2261 goto out_unlock; 2262 2263 len -= vnet_hdr_len; 2264 2265 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2266 vnet_hdr_len); 2267 if (err < 0) 2268 goto out_unlock; 2269 2270 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2271 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2272 vnet_hdr.hdr_len)) 2273 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2274 vnet_hdr.csum_offset + 2; 2275 2276 err = -EINVAL; 2277 if (vnet_hdr.hdr_len > len) 2278 goto out_unlock; 2279 2280 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2281 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2282 case VIRTIO_NET_HDR_GSO_TCPV4: 2283 gso_type = SKB_GSO_TCPV4; 2284 break; 2285 case VIRTIO_NET_HDR_GSO_TCPV6: 2286 gso_type = SKB_GSO_TCPV6; 2287 break; 2288 case VIRTIO_NET_HDR_GSO_UDP: 2289 gso_type = SKB_GSO_UDP; 2290 break; 2291 default: 2292 goto out_unlock; 2293 } 2294 2295 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2296 gso_type |= SKB_GSO_TCP_ECN; 2297 2298 if (vnet_hdr.gso_size == 0) 2299 goto out_unlock; 2300 2301 } 2302 } 2303 2304 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2305 if (!netif_supports_nofcs(dev)) { 2306 err = -EPROTONOSUPPORT; 2307 goto out_unlock; 2308 } 2309 extra_len = 4; /* We're doing our own CRC */ 2310 } 2311 2312 err = -EMSGSIZE; 2313 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2314 goto out_unlock; 2315 2316 err = -ENOBUFS; 2317 hlen = LL_RESERVED_SPACE(dev); 2318 tlen = dev->needed_tailroom; 2319 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2320 msg->msg_flags & MSG_DONTWAIT, &err); 2321 if (skb == NULL) 2322 goto out_unlock; 2323 2324 skb_set_network_header(skb, reserve); 2325 2326 err = -EINVAL; 2327 if (sock->type == SOCK_DGRAM && 2328 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2329 goto out_free; 2330 2331 /* Returns -EFAULT on error */ 2332 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2333 if (err) 2334 goto out_free; 2335 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2336 if (err < 0) 2337 goto out_free; 2338 2339 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2340 /* Earlier code assumed this would be a VLAN pkt, 2341 * double-check this now that we have the actual 2342 * packet in hand. 2343 */ 2344 struct ethhdr *ehdr; 2345 skb_reset_mac_header(skb); 2346 ehdr = eth_hdr(skb); 2347 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2348 err = -EMSGSIZE; 2349 goto out_free; 2350 } 2351 } 2352 2353 skb->protocol = proto; 2354 skb->dev = dev; 2355 skb->priority = sk->sk_priority; 2356 skb->mark = sk->sk_mark; 2357 2358 if (po->has_vnet_hdr) { 2359 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2360 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2361 vnet_hdr.csum_offset)) { 2362 err = -EINVAL; 2363 goto out_free; 2364 } 2365 } 2366 2367 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2368 skb_shinfo(skb)->gso_type = gso_type; 2369 2370 /* Header must be checked, and gso_segs computed. */ 2371 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2372 skb_shinfo(skb)->gso_segs = 0; 2373 2374 len += vnet_hdr_len; 2375 } 2376 2377 if (unlikely(extra_len == 4)) 2378 skb->no_fcs = 1; 2379 2380 /* 2381 * Now send it 2382 */ 2383 2384 err = dev_queue_xmit(skb); 2385 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2386 goto out_unlock; 2387 2388 if (need_rls_dev) 2389 dev_put(dev); 2390 2391 return len; 2392 2393 out_free: 2394 kfree_skb(skb); 2395 out_unlock: 2396 if (dev && need_rls_dev) 2397 dev_put(dev); 2398 out: 2399 return err; 2400 } 2401 2402 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2403 struct msghdr *msg, size_t len) 2404 { 2405 struct sock *sk = sock->sk; 2406 struct packet_sock *po = pkt_sk(sk); 2407 if (po->tx_ring.pg_vec) 2408 return tpacket_snd(po, msg); 2409 else 2410 return packet_snd(sock, msg, len); 2411 } 2412 2413 /* 2414 * Close a PACKET socket. This is fairly simple. We immediately go 2415 * to 'closed' state and remove our protocol entry in the device list. 2416 */ 2417 2418 static int packet_release(struct socket *sock) 2419 { 2420 struct sock *sk = sock->sk; 2421 struct packet_sock *po; 2422 struct net *net; 2423 union tpacket_req_u req_u; 2424 2425 if (!sk) 2426 return 0; 2427 2428 net = sock_net(sk); 2429 po = pkt_sk(sk); 2430 2431 spin_lock_bh(&net->packet.sklist_lock); 2432 sk_del_node_init_rcu(sk); 2433 sock_prot_inuse_add(net, sk->sk_prot, -1); 2434 spin_unlock_bh(&net->packet.sklist_lock); 2435 2436 spin_lock(&po->bind_lock); 2437 unregister_prot_hook(sk, false); 2438 if (po->prot_hook.dev) { 2439 dev_put(po->prot_hook.dev); 2440 po->prot_hook.dev = NULL; 2441 } 2442 spin_unlock(&po->bind_lock); 2443 2444 packet_flush_mclist(sk); 2445 2446 memset(&req_u, 0, sizeof(req_u)); 2447 2448 if (po->rx_ring.pg_vec) 2449 packet_set_ring(sk, &req_u, 1, 0); 2450 2451 if (po->tx_ring.pg_vec) 2452 packet_set_ring(sk, &req_u, 1, 1); 2453 2454 fanout_release(sk); 2455 2456 synchronize_net(); 2457 /* 2458 * Now the socket is dead. No more input will appear. 2459 */ 2460 sock_orphan(sk); 2461 sock->sk = NULL; 2462 2463 /* Purge queues */ 2464 2465 skb_queue_purge(&sk->sk_receive_queue); 2466 sk_refcnt_debug_release(sk); 2467 2468 sock_put(sk); 2469 return 0; 2470 } 2471 2472 /* 2473 * Attach a packet hook. 2474 */ 2475 2476 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2477 { 2478 struct packet_sock *po = pkt_sk(sk); 2479 2480 if (po->fanout) { 2481 if (dev) 2482 dev_put(dev); 2483 2484 return -EINVAL; 2485 } 2486 2487 lock_sock(sk); 2488 2489 spin_lock(&po->bind_lock); 2490 unregister_prot_hook(sk, true); 2491 po->num = protocol; 2492 po->prot_hook.type = protocol; 2493 if (po->prot_hook.dev) 2494 dev_put(po->prot_hook.dev); 2495 po->prot_hook.dev = dev; 2496 2497 po->ifindex = dev ? dev->ifindex : 0; 2498 2499 if (protocol == 0) 2500 goto out_unlock; 2501 2502 if (!dev || (dev->flags & IFF_UP)) { 2503 register_prot_hook(sk); 2504 } else { 2505 sk->sk_err = ENETDOWN; 2506 if (!sock_flag(sk, SOCK_DEAD)) 2507 sk->sk_error_report(sk); 2508 } 2509 2510 out_unlock: 2511 spin_unlock(&po->bind_lock); 2512 release_sock(sk); 2513 return 0; 2514 } 2515 2516 /* 2517 * Bind a packet socket to a device 2518 */ 2519 2520 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2521 int addr_len) 2522 { 2523 struct sock *sk = sock->sk; 2524 char name[15]; 2525 struct net_device *dev; 2526 int err = -ENODEV; 2527 2528 /* 2529 * Check legality 2530 */ 2531 2532 if (addr_len != sizeof(struct sockaddr)) 2533 return -EINVAL; 2534 strlcpy(name, uaddr->sa_data, sizeof(name)); 2535 2536 dev = dev_get_by_name(sock_net(sk), name); 2537 if (dev) 2538 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2539 return err; 2540 } 2541 2542 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2543 { 2544 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2545 struct sock *sk = sock->sk; 2546 struct net_device *dev = NULL; 2547 int err; 2548 2549 2550 /* 2551 * Check legality 2552 */ 2553 2554 if (addr_len < sizeof(struct sockaddr_ll)) 2555 return -EINVAL; 2556 if (sll->sll_family != AF_PACKET) 2557 return -EINVAL; 2558 2559 if (sll->sll_ifindex) { 2560 err = -ENODEV; 2561 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2562 if (dev == NULL) 2563 goto out; 2564 } 2565 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2566 2567 out: 2568 return err; 2569 } 2570 2571 static struct proto packet_proto = { 2572 .name = "PACKET", 2573 .owner = THIS_MODULE, 2574 .obj_size = sizeof(struct packet_sock), 2575 }; 2576 2577 /* 2578 * Create a packet of type SOCK_PACKET. 2579 */ 2580 2581 static int packet_create(struct net *net, struct socket *sock, int protocol, 2582 int kern) 2583 { 2584 struct sock *sk; 2585 struct packet_sock *po; 2586 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2587 int err; 2588 2589 if (!capable(CAP_NET_RAW)) 2590 return -EPERM; 2591 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2592 sock->type != SOCK_PACKET) 2593 return -ESOCKTNOSUPPORT; 2594 2595 sock->state = SS_UNCONNECTED; 2596 2597 err = -ENOBUFS; 2598 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2599 if (sk == NULL) 2600 goto out; 2601 2602 sock->ops = &packet_ops; 2603 if (sock->type == SOCK_PACKET) 2604 sock->ops = &packet_ops_spkt; 2605 2606 sock_init_data(sock, sk); 2607 2608 po = pkt_sk(sk); 2609 sk->sk_family = PF_PACKET; 2610 po->num = proto; 2611 2612 sk->sk_destruct = packet_sock_destruct; 2613 sk_refcnt_debug_inc(sk); 2614 2615 /* 2616 * Attach a protocol block 2617 */ 2618 2619 spin_lock_init(&po->bind_lock); 2620 mutex_init(&po->pg_vec_lock); 2621 po->prot_hook.func = packet_rcv; 2622 2623 if (sock->type == SOCK_PACKET) 2624 po->prot_hook.func = packet_rcv_spkt; 2625 2626 po->prot_hook.af_packet_priv = sk; 2627 2628 if (proto) { 2629 po->prot_hook.type = proto; 2630 register_prot_hook(sk); 2631 } 2632 2633 spin_lock_bh(&net->packet.sklist_lock); 2634 sk_add_node_rcu(sk, &net->packet.sklist); 2635 sock_prot_inuse_add(net, &packet_proto, 1); 2636 spin_unlock_bh(&net->packet.sklist_lock); 2637 2638 return 0; 2639 out: 2640 return err; 2641 } 2642 2643 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2644 { 2645 struct sock_exterr_skb *serr; 2646 struct sk_buff *skb, *skb2; 2647 int copied, err; 2648 2649 err = -EAGAIN; 2650 skb = skb_dequeue(&sk->sk_error_queue); 2651 if (skb == NULL) 2652 goto out; 2653 2654 copied = skb->len; 2655 if (copied > len) { 2656 msg->msg_flags |= MSG_TRUNC; 2657 copied = len; 2658 } 2659 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2660 if (err) 2661 goto out_free_skb; 2662 2663 sock_recv_timestamp(msg, sk, skb); 2664 2665 serr = SKB_EXT_ERR(skb); 2666 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2667 sizeof(serr->ee), &serr->ee); 2668 2669 msg->msg_flags |= MSG_ERRQUEUE; 2670 err = copied; 2671 2672 /* Reset and regenerate socket error */ 2673 spin_lock_bh(&sk->sk_error_queue.lock); 2674 sk->sk_err = 0; 2675 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2676 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2677 spin_unlock_bh(&sk->sk_error_queue.lock); 2678 sk->sk_error_report(sk); 2679 } else 2680 spin_unlock_bh(&sk->sk_error_queue.lock); 2681 2682 out_free_skb: 2683 kfree_skb(skb); 2684 out: 2685 return err; 2686 } 2687 2688 /* 2689 * Pull a packet from our receive queue and hand it to the user. 2690 * If necessary we block. 2691 */ 2692 2693 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2694 struct msghdr *msg, size_t len, int flags) 2695 { 2696 struct sock *sk = sock->sk; 2697 struct sk_buff *skb; 2698 int copied, err; 2699 struct sockaddr_ll *sll; 2700 int vnet_hdr_len = 0; 2701 2702 err = -EINVAL; 2703 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2704 goto out; 2705 2706 #if 0 2707 /* What error should we return now? EUNATTACH? */ 2708 if (pkt_sk(sk)->ifindex < 0) 2709 return -ENODEV; 2710 #endif 2711 2712 if (flags & MSG_ERRQUEUE) { 2713 err = packet_recv_error(sk, msg, len); 2714 goto out; 2715 } 2716 2717 /* 2718 * Call the generic datagram receiver. This handles all sorts 2719 * of horrible races and re-entrancy so we can forget about it 2720 * in the protocol layers. 2721 * 2722 * Now it will return ENETDOWN, if device have just gone down, 2723 * but then it will block. 2724 */ 2725 2726 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2727 2728 /* 2729 * An error occurred so return it. Because skb_recv_datagram() 2730 * handles the blocking we don't see and worry about blocking 2731 * retries. 2732 */ 2733 2734 if (skb == NULL) 2735 goto out; 2736 2737 if (pkt_sk(sk)->has_vnet_hdr) { 2738 struct virtio_net_hdr vnet_hdr = { 0 }; 2739 2740 err = -EINVAL; 2741 vnet_hdr_len = sizeof(vnet_hdr); 2742 if (len < vnet_hdr_len) 2743 goto out_free; 2744 2745 len -= vnet_hdr_len; 2746 2747 if (skb_is_gso(skb)) { 2748 struct skb_shared_info *sinfo = skb_shinfo(skb); 2749 2750 /* This is a hint as to how much should be linear. */ 2751 vnet_hdr.hdr_len = skb_headlen(skb); 2752 vnet_hdr.gso_size = sinfo->gso_size; 2753 if (sinfo->gso_type & SKB_GSO_TCPV4) 2754 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2755 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2756 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2757 else if (sinfo->gso_type & SKB_GSO_UDP) 2758 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2759 else if (sinfo->gso_type & SKB_GSO_FCOE) 2760 goto out_free; 2761 else 2762 BUG(); 2763 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2764 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2765 } else 2766 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2767 2768 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2769 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2770 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2771 vnet_hdr.csum_offset = skb->csum_offset; 2772 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2773 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2774 } /* else everything is zero */ 2775 2776 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2777 vnet_hdr_len); 2778 if (err < 0) 2779 goto out_free; 2780 } 2781 2782 /* 2783 * If the address length field is there to be filled in, we fill 2784 * it in now. 2785 */ 2786 2787 sll = &PACKET_SKB_CB(skb)->sa.ll; 2788 if (sock->type == SOCK_PACKET) 2789 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2790 else 2791 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2792 2793 /* 2794 * You lose any data beyond the buffer you gave. If it worries a 2795 * user program they can ask the device for its MTU anyway. 2796 */ 2797 2798 copied = skb->len; 2799 if (copied > len) { 2800 copied = len; 2801 msg->msg_flags |= MSG_TRUNC; 2802 } 2803 2804 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2805 if (err) 2806 goto out_free; 2807 2808 sock_recv_ts_and_drops(msg, sk, skb); 2809 2810 if (msg->msg_name) 2811 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2812 msg->msg_namelen); 2813 2814 if (pkt_sk(sk)->auxdata) { 2815 struct tpacket_auxdata aux; 2816 2817 aux.tp_status = TP_STATUS_USER; 2818 if (skb->ip_summed == CHECKSUM_PARTIAL) 2819 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2820 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2821 aux.tp_snaplen = skb->len; 2822 aux.tp_mac = 0; 2823 aux.tp_net = skb_network_offset(skb); 2824 if (vlan_tx_tag_present(skb)) { 2825 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2826 aux.tp_status |= TP_STATUS_VLAN_VALID; 2827 } else { 2828 aux.tp_vlan_tci = 0; 2829 } 2830 aux.tp_padding = 0; 2831 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2832 } 2833 2834 /* 2835 * Free or return the buffer as appropriate. Again this 2836 * hides all the races and re-entrancy issues from us. 2837 */ 2838 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2839 2840 out_free: 2841 skb_free_datagram(sk, skb); 2842 out: 2843 return err; 2844 } 2845 2846 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2847 int *uaddr_len, int peer) 2848 { 2849 struct net_device *dev; 2850 struct sock *sk = sock->sk; 2851 2852 if (peer) 2853 return -EOPNOTSUPP; 2854 2855 uaddr->sa_family = AF_PACKET; 2856 rcu_read_lock(); 2857 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2858 if (dev) 2859 strncpy(uaddr->sa_data, dev->name, 14); 2860 else 2861 memset(uaddr->sa_data, 0, 14); 2862 rcu_read_unlock(); 2863 *uaddr_len = sizeof(*uaddr); 2864 2865 return 0; 2866 } 2867 2868 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2869 int *uaddr_len, int peer) 2870 { 2871 struct net_device *dev; 2872 struct sock *sk = sock->sk; 2873 struct packet_sock *po = pkt_sk(sk); 2874 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2875 2876 if (peer) 2877 return -EOPNOTSUPP; 2878 2879 sll->sll_family = AF_PACKET; 2880 sll->sll_ifindex = po->ifindex; 2881 sll->sll_protocol = po->num; 2882 sll->sll_pkttype = 0; 2883 rcu_read_lock(); 2884 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2885 if (dev) { 2886 sll->sll_hatype = dev->type; 2887 sll->sll_halen = dev->addr_len; 2888 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2889 } else { 2890 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2891 sll->sll_halen = 0; 2892 } 2893 rcu_read_unlock(); 2894 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2895 2896 return 0; 2897 } 2898 2899 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2900 int what) 2901 { 2902 switch (i->type) { 2903 case PACKET_MR_MULTICAST: 2904 if (i->alen != dev->addr_len) 2905 return -EINVAL; 2906 if (what > 0) 2907 return dev_mc_add(dev, i->addr); 2908 else 2909 return dev_mc_del(dev, i->addr); 2910 break; 2911 case PACKET_MR_PROMISC: 2912 return dev_set_promiscuity(dev, what); 2913 break; 2914 case PACKET_MR_ALLMULTI: 2915 return dev_set_allmulti(dev, what); 2916 break; 2917 case PACKET_MR_UNICAST: 2918 if (i->alen != dev->addr_len) 2919 return -EINVAL; 2920 if (what > 0) 2921 return dev_uc_add(dev, i->addr); 2922 else 2923 return dev_uc_del(dev, i->addr); 2924 break; 2925 default: 2926 break; 2927 } 2928 return 0; 2929 } 2930 2931 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2932 { 2933 for ( ; i; i = i->next) { 2934 if (i->ifindex == dev->ifindex) 2935 packet_dev_mc(dev, i, what); 2936 } 2937 } 2938 2939 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2940 { 2941 struct packet_sock *po = pkt_sk(sk); 2942 struct packet_mclist *ml, *i; 2943 struct net_device *dev; 2944 int err; 2945 2946 rtnl_lock(); 2947 2948 err = -ENODEV; 2949 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2950 if (!dev) 2951 goto done; 2952 2953 err = -EINVAL; 2954 if (mreq->mr_alen > dev->addr_len) 2955 goto done; 2956 2957 err = -ENOBUFS; 2958 i = kmalloc(sizeof(*i), GFP_KERNEL); 2959 if (i == NULL) 2960 goto done; 2961 2962 err = 0; 2963 for (ml = po->mclist; ml; ml = ml->next) { 2964 if (ml->ifindex == mreq->mr_ifindex && 2965 ml->type == mreq->mr_type && 2966 ml->alen == mreq->mr_alen && 2967 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2968 ml->count++; 2969 /* Free the new element ... */ 2970 kfree(i); 2971 goto done; 2972 } 2973 } 2974 2975 i->type = mreq->mr_type; 2976 i->ifindex = mreq->mr_ifindex; 2977 i->alen = mreq->mr_alen; 2978 memcpy(i->addr, mreq->mr_address, i->alen); 2979 i->count = 1; 2980 i->next = po->mclist; 2981 po->mclist = i; 2982 err = packet_dev_mc(dev, i, 1); 2983 if (err) { 2984 po->mclist = i->next; 2985 kfree(i); 2986 } 2987 2988 done: 2989 rtnl_unlock(); 2990 return err; 2991 } 2992 2993 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2994 { 2995 struct packet_mclist *ml, **mlp; 2996 2997 rtnl_lock(); 2998 2999 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3000 if (ml->ifindex == mreq->mr_ifindex && 3001 ml->type == mreq->mr_type && 3002 ml->alen == mreq->mr_alen && 3003 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3004 if (--ml->count == 0) { 3005 struct net_device *dev; 3006 *mlp = ml->next; 3007 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3008 if (dev) 3009 packet_dev_mc(dev, ml, -1); 3010 kfree(ml); 3011 } 3012 rtnl_unlock(); 3013 return 0; 3014 } 3015 } 3016 rtnl_unlock(); 3017 return -EADDRNOTAVAIL; 3018 } 3019 3020 static void packet_flush_mclist(struct sock *sk) 3021 { 3022 struct packet_sock *po = pkt_sk(sk); 3023 struct packet_mclist *ml; 3024 3025 if (!po->mclist) 3026 return; 3027 3028 rtnl_lock(); 3029 while ((ml = po->mclist) != NULL) { 3030 struct net_device *dev; 3031 3032 po->mclist = ml->next; 3033 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3034 if (dev != NULL) 3035 packet_dev_mc(dev, ml, -1); 3036 kfree(ml); 3037 } 3038 rtnl_unlock(); 3039 } 3040 3041 static int 3042 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3043 { 3044 struct sock *sk = sock->sk; 3045 struct packet_sock *po = pkt_sk(sk); 3046 int ret; 3047 3048 if (level != SOL_PACKET) 3049 return -ENOPROTOOPT; 3050 3051 switch (optname) { 3052 case PACKET_ADD_MEMBERSHIP: 3053 case PACKET_DROP_MEMBERSHIP: 3054 { 3055 struct packet_mreq_max mreq; 3056 int len = optlen; 3057 memset(&mreq, 0, sizeof(mreq)); 3058 if (len < sizeof(struct packet_mreq)) 3059 return -EINVAL; 3060 if (len > sizeof(mreq)) 3061 len = sizeof(mreq); 3062 if (copy_from_user(&mreq, optval, len)) 3063 return -EFAULT; 3064 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3065 return -EINVAL; 3066 if (optname == PACKET_ADD_MEMBERSHIP) 3067 ret = packet_mc_add(sk, &mreq); 3068 else 3069 ret = packet_mc_drop(sk, &mreq); 3070 return ret; 3071 } 3072 3073 case PACKET_RX_RING: 3074 case PACKET_TX_RING: 3075 { 3076 union tpacket_req_u req_u; 3077 int len; 3078 3079 switch (po->tp_version) { 3080 case TPACKET_V1: 3081 case TPACKET_V2: 3082 len = sizeof(req_u.req); 3083 break; 3084 case TPACKET_V3: 3085 default: 3086 len = sizeof(req_u.req3); 3087 break; 3088 } 3089 if (optlen < len) 3090 return -EINVAL; 3091 if (pkt_sk(sk)->has_vnet_hdr) 3092 return -EINVAL; 3093 if (copy_from_user(&req_u.req, optval, len)) 3094 return -EFAULT; 3095 return packet_set_ring(sk, &req_u, 0, 3096 optname == PACKET_TX_RING); 3097 } 3098 case PACKET_COPY_THRESH: 3099 { 3100 int val; 3101 3102 if (optlen != sizeof(val)) 3103 return -EINVAL; 3104 if (copy_from_user(&val, optval, sizeof(val))) 3105 return -EFAULT; 3106 3107 pkt_sk(sk)->copy_thresh = val; 3108 return 0; 3109 } 3110 case PACKET_VERSION: 3111 { 3112 int val; 3113 3114 if (optlen != sizeof(val)) 3115 return -EINVAL; 3116 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3117 return -EBUSY; 3118 if (copy_from_user(&val, optval, sizeof(val))) 3119 return -EFAULT; 3120 switch (val) { 3121 case TPACKET_V1: 3122 case TPACKET_V2: 3123 case TPACKET_V3: 3124 po->tp_version = val; 3125 return 0; 3126 default: 3127 return -EINVAL; 3128 } 3129 } 3130 case PACKET_RESERVE: 3131 { 3132 unsigned int val; 3133 3134 if (optlen != sizeof(val)) 3135 return -EINVAL; 3136 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3137 return -EBUSY; 3138 if (copy_from_user(&val, optval, sizeof(val))) 3139 return -EFAULT; 3140 po->tp_reserve = val; 3141 return 0; 3142 } 3143 case PACKET_LOSS: 3144 { 3145 unsigned int val; 3146 3147 if (optlen != sizeof(val)) 3148 return -EINVAL; 3149 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3150 return -EBUSY; 3151 if (copy_from_user(&val, optval, sizeof(val))) 3152 return -EFAULT; 3153 po->tp_loss = !!val; 3154 return 0; 3155 } 3156 case PACKET_AUXDATA: 3157 { 3158 int val; 3159 3160 if (optlen < sizeof(val)) 3161 return -EINVAL; 3162 if (copy_from_user(&val, optval, sizeof(val))) 3163 return -EFAULT; 3164 3165 po->auxdata = !!val; 3166 return 0; 3167 } 3168 case PACKET_ORIGDEV: 3169 { 3170 int val; 3171 3172 if (optlen < sizeof(val)) 3173 return -EINVAL; 3174 if (copy_from_user(&val, optval, sizeof(val))) 3175 return -EFAULT; 3176 3177 po->origdev = !!val; 3178 return 0; 3179 } 3180 case PACKET_VNET_HDR: 3181 { 3182 int val; 3183 3184 if (sock->type != SOCK_RAW) 3185 return -EINVAL; 3186 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3187 return -EBUSY; 3188 if (optlen < sizeof(val)) 3189 return -EINVAL; 3190 if (copy_from_user(&val, optval, sizeof(val))) 3191 return -EFAULT; 3192 3193 po->has_vnet_hdr = !!val; 3194 return 0; 3195 } 3196 case PACKET_TIMESTAMP: 3197 { 3198 int val; 3199 3200 if (optlen != sizeof(val)) 3201 return -EINVAL; 3202 if (copy_from_user(&val, optval, sizeof(val))) 3203 return -EFAULT; 3204 3205 po->tp_tstamp = val; 3206 return 0; 3207 } 3208 case PACKET_FANOUT: 3209 { 3210 int val; 3211 3212 if (optlen != sizeof(val)) 3213 return -EINVAL; 3214 if (copy_from_user(&val, optval, sizeof(val))) 3215 return -EFAULT; 3216 3217 return fanout_add(sk, val & 0xffff, val >> 16); 3218 } 3219 default: 3220 return -ENOPROTOOPT; 3221 } 3222 } 3223 3224 static int packet_getsockopt(struct socket *sock, int level, int optname, 3225 char __user *optval, int __user *optlen) 3226 { 3227 int len; 3228 int val, lv = sizeof(val); 3229 struct sock *sk = sock->sk; 3230 struct packet_sock *po = pkt_sk(sk); 3231 void *data = &val; 3232 struct tpacket_stats st; 3233 union tpacket_stats_u st_u; 3234 3235 if (level != SOL_PACKET) 3236 return -ENOPROTOOPT; 3237 3238 if (get_user(len, optlen)) 3239 return -EFAULT; 3240 3241 if (len < 0) 3242 return -EINVAL; 3243 3244 switch (optname) { 3245 case PACKET_STATISTICS: 3246 spin_lock_bh(&sk->sk_receive_queue.lock); 3247 if (po->tp_version == TPACKET_V3) { 3248 lv = sizeof(struct tpacket_stats_v3); 3249 memcpy(&st_u.stats3, &po->stats, 3250 sizeof(struct tpacket_stats)); 3251 st_u.stats3.tp_freeze_q_cnt = 3252 po->stats_u.stats3.tp_freeze_q_cnt; 3253 st_u.stats3.tp_packets += po->stats.tp_drops; 3254 data = &st_u.stats3; 3255 } else { 3256 lv = sizeof(struct tpacket_stats); 3257 st = po->stats; 3258 st.tp_packets += st.tp_drops; 3259 data = &st; 3260 } 3261 memset(&po->stats, 0, sizeof(st)); 3262 spin_unlock_bh(&sk->sk_receive_queue.lock); 3263 break; 3264 case PACKET_AUXDATA: 3265 val = po->auxdata; 3266 break; 3267 case PACKET_ORIGDEV: 3268 val = po->origdev; 3269 break; 3270 case PACKET_VNET_HDR: 3271 val = po->has_vnet_hdr; 3272 break; 3273 case PACKET_VERSION: 3274 val = po->tp_version; 3275 break; 3276 case PACKET_HDRLEN: 3277 if (len > sizeof(int)) 3278 len = sizeof(int); 3279 if (copy_from_user(&val, optval, len)) 3280 return -EFAULT; 3281 switch (val) { 3282 case TPACKET_V1: 3283 val = sizeof(struct tpacket_hdr); 3284 break; 3285 case TPACKET_V2: 3286 val = sizeof(struct tpacket2_hdr); 3287 break; 3288 case TPACKET_V3: 3289 val = sizeof(struct tpacket3_hdr); 3290 break; 3291 default: 3292 return -EINVAL; 3293 } 3294 break; 3295 case PACKET_RESERVE: 3296 val = po->tp_reserve; 3297 break; 3298 case PACKET_LOSS: 3299 val = po->tp_loss; 3300 break; 3301 case PACKET_TIMESTAMP: 3302 val = po->tp_tstamp; 3303 break; 3304 case PACKET_FANOUT: 3305 val = (po->fanout ? 3306 ((u32)po->fanout->id | 3307 ((u32)po->fanout->type << 16)) : 3308 0); 3309 break; 3310 default: 3311 return -ENOPROTOOPT; 3312 } 3313 3314 if (len > lv) 3315 len = lv; 3316 if (put_user(len, optlen)) 3317 return -EFAULT; 3318 if (copy_to_user(optval, data, len)) 3319 return -EFAULT; 3320 return 0; 3321 } 3322 3323 3324 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3325 { 3326 struct sock *sk; 3327 struct hlist_node *node; 3328 struct net_device *dev = data; 3329 struct net *net = dev_net(dev); 3330 3331 rcu_read_lock(); 3332 sk_for_each_rcu(sk, node, &net->packet.sklist) { 3333 struct packet_sock *po = pkt_sk(sk); 3334 3335 switch (msg) { 3336 case NETDEV_UNREGISTER: 3337 if (po->mclist) 3338 packet_dev_mclist(dev, po->mclist, -1); 3339 /* fallthrough */ 3340 3341 case NETDEV_DOWN: 3342 if (dev->ifindex == po->ifindex) { 3343 spin_lock(&po->bind_lock); 3344 if (po->running) { 3345 __unregister_prot_hook(sk, false); 3346 sk->sk_err = ENETDOWN; 3347 if (!sock_flag(sk, SOCK_DEAD)) 3348 sk->sk_error_report(sk); 3349 } 3350 if (msg == NETDEV_UNREGISTER) { 3351 po->ifindex = -1; 3352 if (po->prot_hook.dev) 3353 dev_put(po->prot_hook.dev); 3354 po->prot_hook.dev = NULL; 3355 } 3356 spin_unlock(&po->bind_lock); 3357 } 3358 break; 3359 case NETDEV_UP: 3360 if (dev->ifindex == po->ifindex) { 3361 spin_lock(&po->bind_lock); 3362 if (po->num) 3363 register_prot_hook(sk); 3364 spin_unlock(&po->bind_lock); 3365 } 3366 break; 3367 } 3368 } 3369 rcu_read_unlock(); 3370 return NOTIFY_DONE; 3371 } 3372 3373 3374 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3375 unsigned long arg) 3376 { 3377 struct sock *sk = sock->sk; 3378 3379 switch (cmd) { 3380 case SIOCOUTQ: 3381 { 3382 int amount = sk_wmem_alloc_get(sk); 3383 3384 return put_user(amount, (int __user *)arg); 3385 } 3386 case SIOCINQ: 3387 { 3388 struct sk_buff *skb; 3389 int amount = 0; 3390 3391 spin_lock_bh(&sk->sk_receive_queue.lock); 3392 skb = skb_peek(&sk->sk_receive_queue); 3393 if (skb) 3394 amount = skb->len; 3395 spin_unlock_bh(&sk->sk_receive_queue.lock); 3396 return put_user(amount, (int __user *)arg); 3397 } 3398 case SIOCGSTAMP: 3399 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3400 case SIOCGSTAMPNS: 3401 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3402 3403 #ifdef CONFIG_INET 3404 case SIOCADDRT: 3405 case SIOCDELRT: 3406 case SIOCDARP: 3407 case SIOCGARP: 3408 case SIOCSARP: 3409 case SIOCGIFADDR: 3410 case SIOCSIFADDR: 3411 case SIOCGIFBRDADDR: 3412 case SIOCSIFBRDADDR: 3413 case SIOCGIFNETMASK: 3414 case SIOCSIFNETMASK: 3415 case SIOCGIFDSTADDR: 3416 case SIOCSIFDSTADDR: 3417 case SIOCSIFFLAGS: 3418 return inet_dgram_ops.ioctl(sock, cmd, arg); 3419 #endif 3420 3421 default: 3422 return -ENOIOCTLCMD; 3423 } 3424 return 0; 3425 } 3426 3427 static unsigned int packet_poll(struct file *file, struct socket *sock, 3428 poll_table *wait) 3429 { 3430 struct sock *sk = sock->sk; 3431 struct packet_sock *po = pkt_sk(sk); 3432 unsigned int mask = datagram_poll(file, sock, wait); 3433 3434 spin_lock_bh(&sk->sk_receive_queue.lock); 3435 if (po->rx_ring.pg_vec) { 3436 if (!packet_previous_rx_frame(po, &po->rx_ring, 3437 TP_STATUS_KERNEL)) 3438 mask |= POLLIN | POLLRDNORM; 3439 } 3440 spin_unlock_bh(&sk->sk_receive_queue.lock); 3441 spin_lock_bh(&sk->sk_write_queue.lock); 3442 if (po->tx_ring.pg_vec) { 3443 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3444 mask |= POLLOUT | POLLWRNORM; 3445 } 3446 spin_unlock_bh(&sk->sk_write_queue.lock); 3447 return mask; 3448 } 3449 3450 3451 /* Dirty? Well, I still did not learn better way to account 3452 * for user mmaps. 3453 */ 3454 3455 static void packet_mm_open(struct vm_area_struct *vma) 3456 { 3457 struct file *file = vma->vm_file; 3458 struct socket *sock = file->private_data; 3459 struct sock *sk = sock->sk; 3460 3461 if (sk) 3462 atomic_inc(&pkt_sk(sk)->mapped); 3463 } 3464 3465 static void packet_mm_close(struct vm_area_struct *vma) 3466 { 3467 struct file *file = vma->vm_file; 3468 struct socket *sock = file->private_data; 3469 struct sock *sk = sock->sk; 3470 3471 if (sk) 3472 atomic_dec(&pkt_sk(sk)->mapped); 3473 } 3474 3475 static const struct vm_operations_struct packet_mmap_ops = { 3476 .open = packet_mm_open, 3477 .close = packet_mm_close, 3478 }; 3479 3480 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3481 unsigned int len) 3482 { 3483 int i; 3484 3485 for (i = 0; i < len; i++) { 3486 if (likely(pg_vec[i].buffer)) { 3487 if (is_vmalloc_addr(pg_vec[i].buffer)) 3488 vfree(pg_vec[i].buffer); 3489 else 3490 free_pages((unsigned long)pg_vec[i].buffer, 3491 order); 3492 pg_vec[i].buffer = NULL; 3493 } 3494 } 3495 kfree(pg_vec); 3496 } 3497 3498 static char *alloc_one_pg_vec_page(unsigned long order) 3499 { 3500 char *buffer = NULL; 3501 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3502 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3503 3504 buffer = (char *) __get_free_pages(gfp_flags, order); 3505 3506 if (buffer) 3507 return buffer; 3508 3509 /* 3510 * __get_free_pages failed, fall back to vmalloc 3511 */ 3512 buffer = vzalloc((1 << order) * PAGE_SIZE); 3513 3514 if (buffer) 3515 return buffer; 3516 3517 /* 3518 * vmalloc failed, lets dig into swap here 3519 */ 3520 gfp_flags &= ~__GFP_NORETRY; 3521 buffer = (char *)__get_free_pages(gfp_flags, order); 3522 if (buffer) 3523 return buffer; 3524 3525 /* 3526 * complete and utter failure 3527 */ 3528 return NULL; 3529 } 3530 3531 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3532 { 3533 unsigned int block_nr = req->tp_block_nr; 3534 struct pgv *pg_vec; 3535 int i; 3536 3537 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3538 if (unlikely(!pg_vec)) 3539 goto out; 3540 3541 for (i = 0; i < block_nr; i++) { 3542 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3543 if (unlikely(!pg_vec[i].buffer)) 3544 goto out_free_pgvec; 3545 } 3546 3547 out: 3548 return pg_vec; 3549 3550 out_free_pgvec: 3551 free_pg_vec(pg_vec, order, block_nr); 3552 pg_vec = NULL; 3553 goto out; 3554 } 3555 3556 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3557 int closing, int tx_ring) 3558 { 3559 struct pgv *pg_vec = NULL; 3560 struct packet_sock *po = pkt_sk(sk); 3561 int was_running, order = 0; 3562 struct packet_ring_buffer *rb; 3563 struct sk_buff_head *rb_queue; 3564 __be16 num; 3565 int err = -EINVAL; 3566 /* Added to avoid minimal code churn */ 3567 struct tpacket_req *req = &req_u->req; 3568 3569 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3570 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3571 WARN(1, "Tx-ring is not supported.\n"); 3572 goto out; 3573 } 3574 3575 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3576 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3577 3578 err = -EBUSY; 3579 if (!closing) { 3580 if (atomic_read(&po->mapped)) 3581 goto out; 3582 if (atomic_read(&rb->pending)) 3583 goto out; 3584 } 3585 3586 if (req->tp_block_nr) { 3587 /* Sanity tests and some calculations */ 3588 err = -EBUSY; 3589 if (unlikely(rb->pg_vec)) 3590 goto out; 3591 3592 switch (po->tp_version) { 3593 case TPACKET_V1: 3594 po->tp_hdrlen = TPACKET_HDRLEN; 3595 break; 3596 case TPACKET_V2: 3597 po->tp_hdrlen = TPACKET2_HDRLEN; 3598 break; 3599 case TPACKET_V3: 3600 po->tp_hdrlen = TPACKET3_HDRLEN; 3601 break; 3602 } 3603 3604 err = -EINVAL; 3605 if (unlikely((int)req->tp_block_size <= 0)) 3606 goto out; 3607 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3608 goto out; 3609 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3610 po->tp_reserve)) 3611 goto out; 3612 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3613 goto out; 3614 3615 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3616 if (unlikely(rb->frames_per_block <= 0)) 3617 goto out; 3618 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3619 req->tp_frame_nr)) 3620 goto out; 3621 3622 err = -ENOMEM; 3623 order = get_order(req->tp_block_size); 3624 pg_vec = alloc_pg_vec(req, order); 3625 if (unlikely(!pg_vec)) 3626 goto out; 3627 switch (po->tp_version) { 3628 case TPACKET_V3: 3629 /* Transmit path is not supported. We checked 3630 * it above but just being paranoid 3631 */ 3632 if (!tx_ring) 3633 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3634 break; 3635 default: 3636 break; 3637 } 3638 } 3639 /* Done */ 3640 else { 3641 err = -EINVAL; 3642 if (unlikely(req->tp_frame_nr)) 3643 goto out; 3644 } 3645 3646 lock_sock(sk); 3647 3648 /* Detach socket from network */ 3649 spin_lock(&po->bind_lock); 3650 was_running = po->running; 3651 num = po->num; 3652 if (was_running) { 3653 po->num = 0; 3654 __unregister_prot_hook(sk, false); 3655 } 3656 spin_unlock(&po->bind_lock); 3657 3658 synchronize_net(); 3659 3660 err = -EBUSY; 3661 mutex_lock(&po->pg_vec_lock); 3662 if (closing || atomic_read(&po->mapped) == 0) { 3663 err = 0; 3664 spin_lock_bh(&rb_queue->lock); 3665 swap(rb->pg_vec, pg_vec); 3666 rb->frame_max = (req->tp_frame_nr - 1); 3667 rb->head = 0; 3668 rb->frame_size = req->tp_frame_size; 3669 spin_unlock_bh(&rb_queue->lock); 3670 3671 swap(rb->pg_vec_order, order); 3672 swap(rb->pg_vec_len, req->tp_block_nr); 3673 3674 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3675 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3676 tpacket_rcv : packet_rcv; 3677 skb_queue_purge(rb_queue); 3678 if (atomic_read(&po->mapped)) 3679 pr_err("packet_mmap: vma is busy: %d\n", 3680 atomic_read(&po->mapped)); 3681 } 3682 mutex_unlock(&po->pg_vec_lock); 3683 3684 spin_lock(&po->bind_lock); 3685 if (was_running) { 3686 po->num = num; 3687 register_prot_hook(sk); 3688 } 3689 spin_unlock(&po->bind_lock); 3690 if (closing && (po->tp_version > TPACKET_V2)) { 3691 /* Because we don't support block-based V3 on tx-ring */ 3692 if (!tx_ring) 3693 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3694 } 3695 release_sock(sk); 3696 3697 if (pg_vec) 3698 free_pg_vec(pg_vec, order, req->tp_block_nr); 3699 out: 3700 return err; 3701 } 3702 3703 static int packet_mmap(struct file *file, struct socket *sock, 3704 struct vm_area_struct *vma) 3705 { 3706 struct sock *sk = sock->sk; 3707 struct packet_sock *po = pkt_sk(sk); 3708 unsigned long size, expected_size; 3709 struct packet_ring_buffer *rb; 3710 unsigned long start; 3711 int err = -EINVAL; 3712 int i; 3713 3714 if (vma->vm_pgoff) 3715 return -EINVAL; 3716 3717 mutex_lock(&po->pg_vec_lock); 3718 3719 expected_size = 0; 3720 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3721 if (rb->pg_vec) { 3722 expected_size += rb->pg_vec_len 3723 * rb->pg_vec_pages 3724 * PAGE_SIZE; 3725 } 3726 } 3727 3728 if (expected_size == 0) 3729 goto out; 3730 3731 size = vma->vm_end - vma->vm_start; 3732 if (size != expected_size) 3733 goto out; 3734 3735 start = vma->vm_start; 3736 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3737 if (rb->pg_vec == NULL) 3738 continue; 3739 3740 for (i = 0; i < rb->pg_vec_len; i++) { 3741 struct page *page; 3742 void *kaddr = rb->pg_vec[i].buffer; 3743 int pg_num; 3744 3745 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3746 page = pgv_to_page(kaddr); 3747 err = vm_insert_page(vma, start, page); 3748 if (unlikely(err)) 3749 goto out; 3750 start += PAGE_SIZE; 3751 kaddr += PAGE_SIZE; 3752 } 3753 } 3754 } 3755 3756 atomic_inc(&po->mapped); 3757 vma->vm_ops = &packet_mmap_ops; 3758 err = 0; 3759 3760 out: 3761 mutex_unlock(&po->pg_vec_lock); 3762 return err; 3763 } 3764 3765 static const struct proto_ops packet_ops_spkt = { 3766 .family = PF_PACKET, 3767 .owner = THIS_MODULE, 3768 .release = packet_release, 3769 .bind = packet_bind_spkt, 3770 .connect = sock_no_connect, 3771 .socketpair = sock_no_socketpair, 3772 .accept = sock_no_accept, 3773 .getname = packet_getname_spkt, 3774 .poll = datagram_poll, 3775 .ioctl = packet_ioctl, 3776 .listen = sock_no_listen, 3777 .shutdown = sock_no_shutdown, 3778 .setsockopt = sock_no_setsockopt, 3779 .getsockopt = sock_no_getsockopt, 3780 .sendmsg = packet_sendmsg_spkt, 3781 .recvmsg = packet_recvmsg, 3782 .mmap = sock_no_mmap, 3783 .sendpage = sock_no_sendpage, 3784 }; 3785 3786 static const struct proto_ops packet_ops = { 3787 .family = PF_PACKET, 3788 .owner = THIS_MODULE, 3789 .release = packet_release, 3790 .bind = packet_bind, 3791 .connect = sock_no_connect, 3792 .socketpair = sock_no_socketpair, 3793 .accept = sock_no_accept, 3794 .getname = packet_getname, 3795 .poll = packet_poll, 3796 .ioctl = packet_ioctl, 3797 .listen = sock_no_listen, 3798 .shutdown = sock_no_shutdown, 3799 .setsockopt = packet_setsockopt, 3800 .getsockopt = packet_getsockopt, 3801 .sendmsg = packet_sendmsg, 3802 .recvmsg = packet_recvmsg, 3803 .mmap = packet_mmap, 3804 .sendpage = sock_no_sendpage, 3805 }; 3806 3807 static const struct net_proto_family packet_family_ops = { 3808 .family = PF_PACKET, 3809 .create = packet_create, 3810 .owner = THIS_MODULE, 3811 }; 3812 3813 static struct notifier_block packet_netdev_notifier = { 3814 .notifier_call = packet_notifier, 3815 }; 3816 3817 #ifdef CONFIG_PROC_FS 3818 3819 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3820 __acquires(RCU) 3821 { 3822 struct net *net = seq_file_net(seq); 3823 3824 rcu_read_lock(); 3825 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3826 } 3827 3828 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3829 { 3830 struct net *net = seq_file_net(seq); 3831 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3832 } 3833 3834 static void packet_seq_stop(struct seq_file *seq, void *v) 3835 __releases(RCU) 3836 { 3837 rcu_read_unlock(); 3838 } 3839 3840 static int packet_seq_show(struct seq_file *seq, void *v) 3841 { 3842 if (v == SEQ_START_TOKEN) 3843 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3844 else { 3845 struct sock *s = sk_entry(v); 3846 const struct packet_sock *po = pkt_sk(s); 3847 3848 seq_printf(seq, 3849 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3850 s, 3851 atomic_read(&s->sk_refcnt), 3852 s->sk_type, 3853 ntohs(po->num), 3854 po->ifindex, 3855 po->running, 3856 atomic_read(&s->sk_rmem_alloc), 3857 sock_i_uid(s), 3858 sock_i_ino(s)); 3859 } 3860 3861 return 0; 3862 } 3863 3864 static const struct seq_operations packet_seq_ops = { 3865 .start = packet_seq_start, 3866 .next = packet_seq_next, 3867 .stop = packet_seq_stop, 3868 .show = packet_seq_show, 3869 }; 3870 3871 static int packet_seq_open(struct inode *inode, struct file *file) 3872 { 3873 return seq_open_net(inode, file, &packet_seq_ops, 3874 sizeof(struct seq_net_private)); 3875 } 3876 3877 static const struct file_operations packet_seq_fops = { 3878 .owner = THIS_MODULE, 3879 .open = packet_seq_open, 3880 .read = seq_read, 3881 .llseek = seq_lseek, 3882 .release = seq_release_net, 3883 }; 3884 3885 #endif 3886 3887 static int __net_init packet_net_init(struct net *net) 3888 { 3889 spin_lock_init(&net->packet.sklist_lock); 3890 INIT_HLIST_HEAD(&net->packet.sklist); 3891 3892 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops)) 3893 return -ENOMEM; 3894 3895 return 0; 3896 } 3897 3898 static void __net_exit packet_net_exit(struct net *net) 3899 { 3900 proc_net_remove(net, "packet"); 3901 } 3902 3903 static struct pernet_operations packet_net_ops = { 3904 .init = packet_net_init, 3905 .exit = packet_net_exit, 3906 }; 3907 3908 3909 static void __exit packet_exit(void) 3910 { 3911 unregister_netdevice_notifier(&packet_netdev_notifier); 3912 unregister_pernet_subsys(&packet_net_ops); 3913 sock_unregister(PF_PACKET); 3914 proto_unregister(&packet_proto); 3915 } 3916 3917 static int __init packet_init(void) 3918 { 3919 int rc = proto_register(&packet_proto, 0); 3920 3921 if (rc != 0) 3922 goto out; 3923 3924 sock_register(&packet_family_ops); 3925 register_pernet_subsys(&packet_net_ops); 3926 register_netdevice_notifier(&packet_netdev_notifier); 3927 out: 3928 return rc; 3929 } 3930 3931 module_init(packet_init); 3932 module_exit(packet_exit); 3933 MODULE_LICENSE("GPL"); 3934 MODULE_ALIAS_NETPROTO(PF_PACKET); 3935