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 0; 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 int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1277 { 1278 struct packet_sock *po = pkt_sk(sk); 1279 struct packet_fanout *f, *match; 1280 u8 type = type_flags & 0xff; 1281 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; 1282 int err; 1283 1284 switch (type) { 1285 case PACKET_FANOUT_HASH: 1286 case PACKET_FANOUT_LB: 1287 case PACKET_FANOUT_CPU: 1288 break; 1289 default: 1290 return -EINVAL; 1291 } 1292 1293 if (!po->running) 1294 return -EINVAL; 1295 1296 if (po->fanout) 1297 return -EALREADY; 1298 1299 mutex_lock(&fanout_mutex); 1300 match = NULL; 1301 list_for_each_entry(f, &fanout_list, list) { 1302 if (f->id == id && 1303 read_pnet(&f->net) == sock_net(sk)) { 1304 match = f; 1305 break; 1306 } 1307 } 1308 err = -EINVAL; 1309 if (match && match->defrag != defrag) 1310 goto out; 1311 if (!match) { 1312 err = -ENOMEM; 1313 match = kzalloc(sizeof(*match), GFP_KERNEL); 1314 if (!match) 1315 goto out; 1316 write_pnet(&match->net, sock_net(sk)); 1317 match->id = id; 1318 match->type = type; 1319 match->defrag = defrag; 1320 atomic_set(&match->rr_cur, 0); 1321 INIT_LIST_HEAD(&match->list); 1322 spin_lock_init(&match->lock); 1323 atomic_set(&match->sk_ref, 0); 1324 match->prot_hook.type = po->prot_hook.type; 1325 match->prot_hook.dev = po->prot_hook.dev; 1326 match->prot_hook.func = packet_rcv_fanout; 1327 match->prot_hook.af_packet_priv = match; 1328 dev_add_pack(&match->prot_hook); 1329 list_add(&match->list, &fanout_list); 1330 } 1331 err = -EINVAL; 1332 if (match->type == type && 1333 match->prot_hook.type == po->prot_hook.type && 1334 match->prot_hook.dev == po->prot_hook.dev) { 1335 err = -ENOSPC; 1336 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1337 __dev_remove_pack(&po->prot_hook); 1338 po->fanout = match; 1339 atomic_inc(&match->sk_ref); 1340 __fanout_link(sk, po); 1341 err = 0; 1342 } 1343 } 1344 out: 1345 mutex_unlock(&fanout_mutex); 1346 return err; 1347 } 1348 1349 static void fanout_release(struct sock *sk) 1350 { 1351 struct packet_sock *po = pkt_sk(sk); 1352 struct packet_fanout *f; 1353 1354 f = po->fanout; 1355 if (!f) 1356 return; 1357 1358 po->fanout = NULL; 1359 1360 mutex_lock(&fanout_mutex); 1361 if (atomic_dec_and_test(&f->sk_ref)) { 1362 list_del(&f->list); 1363 dev_remove_pack(&f->prot_hook); 1364 kfree(f); 1365 } 1366 mutex_unlock(&fanout_mutex); 1367 } 1368 1369 static const struct proto_ops packet_ops; 1370 1371 static const struct proto_ops packet_ops_spkt; 1372 1373 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1374 struct packet_type *pt, struct net_device *orig_dev) 1375 { 1376 struct sock *sk; 1377 struct sockaddr_pkt *spkt; 1378 1379 /* 1380 * When we registered the protocol we saved the socket in the data 1381 * field for just this event. 1382 */ 1383 1384 sk = pt->af_packet_priv; 1385 1386 /* 1387 * Yank back the headers [hope the device set this 1388 * right or kerboom...] 1389 * 1390 * Incoming packets have ll header pulled, 1391 * push it back. 1392 * 1393 * For outgoing ones skb->data == skb_mac_header(skb) 1394 * so that this procedure is noop. 1395 */ 1396 1397 if (skb->pkt_type == PACKET_LOOPBACK) 1398 goto out; 1399 1400 if (!net_eq(dev_net(dev), sock_net(sk))) 1401 goto out; 1402 1403 skb = skb_share_check(skb, GFP_ATOMIC); 1404 if (skb == NULL) 1405 goto oom; 1406 1407 /* drop any routing info */ 1408 skb_dst_drop(skb); 1409 1410 /* drop conntrack reference */ 1411 nf_reset(skb); 1412 1413 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1414 1415 skb_push(skb, skb->data - skb_mac_header(skb)); 1416 1417 /* 1418 * The SOCK_PACKET socket receives _all_ frames. 1419 */ 1420 1421 spkt->spkt_family = dev->type; 1422 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1423 spkt->spkt_protocol = skb->protocol; 1424 1425 /* 1426 * Charge the memory to the socket. This is done specifically 1427 * to prevent sockets using all the memory up. 1428 */ 1429 1430 if (sock_queue_rcv_skb(sk, skb) == 0) 1431 return 0; 1432 1433 out: 1434 kfree_skb(skb); 1435 oom: 1436 return 0; 1437 } 1438 1439 1440 /* 1441 * Output a raw packet to a device layer. This bypasses all the other 1442 * protocol layers and you must therefore supply it with a complete frame 1443 */ 1444 1445 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1446 struct msghdr *msg, size_t len) 1447 { 1448 struct sock *sk = sock->sk; 1449 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1450 struct sk_buff *skb = NULL; 1451 struct net_device *dev; 1452 __be16 proto = 0; 1453 int err; 1454 int extra_len = 0; 1455 1456 /* 1457 * Get and verify the address. 1458 */ 1459 1460 if (saddr) { 1461 if (msg->msg_namelen < sizeof(struct sockaddr)) 1462 return -EINVAL; 1463 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1464 proto = saddr->spkt_protocol; 1465 } else 1466 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1467 1468 /* 1469 * Find the device first to size check it 1470 */ 1471 1472 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1473 retry: 1474 rcu_read_lock(); 1475 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1476 err = -ENODEV; 1477 if (dev == NULL) 1478 goto out_unlock; 1479 1480 err = -ENETDOWN; 1481 if (!(dev->flags & IFF_UP)) 1482 goto out_unlock; 1483 1484 /* 1485 * You may not queue a frame bigger than the mtu. This is the lowest level 1486 * raw protocol and you must do your own fragmentation at this level. 1487 */ 1488 1489 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1490 if (!netif_supports_nofcs(dev)) { 1491 err = -EPROTONOSUPPORT; 1492 goto out_unlock; 1493 } 1494 extra_len = 4; /* We're doing our own CRC */ 1495 } 1496 1497 err = -EMSGSIZE; 1498 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1499 goto out_unlock; 1500 1501 if (!skb) { 1502 size_t reserved = LL_RESERVED_SPACE(dev); 1503 int tlen = dev->needed_tailroom; 1504 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1505 1506 rcu_read_unlock(); 1507 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1508 if (skb == NULL) 1509 return -ENOBUFS; 1510 /* FIXME: Save some space for broken drivers that write a hard 1511 * header at transmission time by themselves. PPP is the notable 1512 * one here. This should really be fixed at the driver level. 1513 */ 1514 skb_reserve(skb, reserved); 1515 skb_reset_network_header(skb); 1516 1517 /* Try to align data part correctly */ 1518 if (hhlen) { 1519 skb->data -= hhlen; 1520 skb->tail -= hhlen; 1521 if (len < hhlen) 1522 skb_reset_network_header(skb); 1523 } 1524 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1525 if (err) 1526 goto out_free; 1527 goto retry; 1528 } 1529 1530 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1531 /* Earlier code assumed this would be a VLAN pkt, 1532 * double-check this now that we have the actual 1533 * packet in hand. 1534 */ 1535 struct ethhdr *ehdr; 1536 skb_reset_mac_header(skb); 1537 ehdr = eth_hdr(skb); 1538 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1539 err = -EMSGSIZE; 1540 goto out_unlock; 1541 } 1542 } 1543 1544 skb->protocol = proto; 1545 skb->dev = dev; 1546 skb->priority = sk->sk_priority; 1547 skb->mark = sk->sk_mark; 1548 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1549 if (err < 0) 1550 goto out_unlock; 1551 1552 if (unlikely(extra_len == 4)) 1553 skb->no_fcs = 1; 1554 1555 dev_queue_xmit(skb); 1556 rcu_read_unlock(); 1557 return len; 1558 1559 out_unlock: 1560 rcu_read_unlock(); 1561 out_free: 1562 kfree_skb(skb); 1563 return err; 1564 } 1565 1566 static unsigned int run_filter(const struct sk_buff *skb, 1567 const struct sock *sk, 1568 unsigned int res) 1569 { 1570 struct sk_filter *filter; 1571 1572 rcu_read_lock(); 1573 filter = rcu_dereference(sk->sk_filter); 1574 if (filter != NULL) 1575 res = SK_RUN_FILTER(filter, skb); 1576 rcu_read_unlock(); 1577 1578 return res; 1579 } 1580 1581 /* 1582 * This function makes lazy skb cloning in hope that most of packets 1583 * are discarded by BPF. 1584 * 1585 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1586 * and skb->cb are mangled. It works because (and until) packets 1587 * falling here are owned by current CPU. Output packets are cloned 1588 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1589 * sequencially, so that if we return skb to original state on exit, 1590 * we will not harm anyone. 1591 */ 1592 1593 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1594 struct packet_type *pt, struct net_device *orig_dev) 1595 { 1596 struct sock *sk; 1597 struct sockaddr_ll *sll; 1598 struct packet_sock *po; 1599 u8 *skb_head = skb->data; 1600 int skb_len = skb->len; 1601 unsigned int snaplen, res; 1602 1603 if (skb->pkt_type == PACKET_LOOPBACK) 1604 goto drop; 1605 1606 sk = pt->af_packet_priv; 1607 po = pkt_sk(sk); 1608 1609 if (!net_eq(dev_net(dev), sock_net(sk))) 1610 goto drop; 1611 1612 skb->dev = dev; 1613 1614 if (dev->header_ops) { 1615 /* The device has an explicit notion of ll header, 1616 * exported to higher levels. 1617 * 1618 * Otherwise, the device hides details of its frame 1619 * structure, so that corresponding packet head is 1620 * never delivered to user. 1621 */ 1622 if (sk->sk_type != SOCK_DGRAM) 1623 skb_push(skb, skb->data - skb_mac_header(skb)); 1624 else if (skb->pkt_type == PACKET_OUTGOING) { 1625 /* Special case: outgoing packets have ll header at head */ 1626 skb_pull(skb, skb_network_offset(skb)); 1627 } 1628 } 1629 1630 snaplen = skb->len; 1631 1632 res = run_filter(skb, sk, snaplen); 1633 if (!res) 1634 goto drop_n_restore; 1635 if (snaplen > res) 1636 snaplen = res; 1637 1638 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1639 goto drop_n_acct; 1640 1641 if (skb_shared(skb)) { 1642 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1643 if (nskb == NULL) 1644 goto drop_n_acct; 1645 1646 if (skb_head != skb->data) { 1647 skb->data = skb_head; 1648 skb->len = skb_len; 1649 } 1650 consume_skb(skb); 1651 skb = nskb; 1652 } 1653 1654 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1655 sizeof(skb->cb)); 1656 1657 sll = &PACKET_SKB_CB(skb)->sa.ll; 1658 sll->sll_family = AF_PACKET; 1659 sll->sll_hatype = dev->type; 1660 sll->sll_protocol = skb->protocol; 1661 sll->sll_pkttype = skb->pkt_type; 1662 if (unlikely(po->origdev)) 1663 sll->sll_ifindex = orig_dev->ifindex; 1664 else 1665 sll->sll_ifindex = dev->ifindex; 1666 1667 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1668 1669 PACKET_SKB_CB(skb)->origlen = skb->len; 1670 1671 if (pskb_trim(skb, snaplen)) 1672 goto drop_n_acct; 1673 1674 skb_set_owner_r(skb, sk); 1675 skb->dev = NULL; 1676 skb_dst_drop(skb); 1677 1678 /* drop conntrack reference */ 1679 nf_reset(skb); 1680 1681 spin_lock(&sk->sk_receive_queue.lock); 1682 po->stats.tp_packets++; 1683 skb->dropcount = atomic_read(&sk->sk_drops); 1684 __skb_queue_tail(&sk->sk_receive_queue, skb); 1685 spin_unlock(&sk->sk_receive_queue.lock); 1686 sk->sk_data_ready(sk, skb->len); 1687 return 0; 1688 1689 drop_n_acct: 1690 spin_lock(&sk->sk_receive_queue.lock); 1691 po->stats.tp_drops++; 1692 atomic_inc(&sk->sk_drops); 1693 spin_unlock(&sk->sk_receive_queue.lock); 1694 1695 drop_n_restore: 1696 if (skb_head != skb->data && skb_shared(skb)) { 1697 skb->data = skb_head; 1698 skb->len = skb_len; 1699 } 1700 drop: 1701 consume_skb(skb); 1702 return 0; 1703 } 1704 1705 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1706 struct packet_type *pt, struct net_device *orig_dev) 1707 { 1708 struct sock *sk; 1709 struct packet_sock *po; 1710 struct sockaddr_ll *sll; 1711 union { 1712 struct tpacket_hdr *h1; 1713 struct tpacket2_hdr *h2; 1714 struct tpacket3_hdr *h3; 1715 void *raw; 1716 } h; 1717 u8 *skb_head = skb->data; 1718 int skb_len = skb->len; 1719 unsigned int snaplen, res; 1720 unsigned long status = TP_STATUS_USER; 1721 unsigned short macoff, netoff, hdrlen; 1722 struct sk_buff *copy_skb = NULL; 1723 struct timeval tv; 1724 struct timespec ts; 1725 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 1726 1727 if (skb->pkt_type == PACKET_LOOPBACK) 1728 goto drop; 1729 1730 sk = pt->af_packet_priv; 1731 po = pkt_sk(sk); 1732 1733 if (!net_eq(dev_net(dev), sock_net(sk))) 1734 goto drop; 1735 1736 if (dev->header_ops) { 1737 if (sk->sk_type != SOCK_DGRAM) 1738 skb_push(skb, skb->data - skb_mac_header(skb)); 1739 else if (skb->pkt_type == PACKET_OUTGOING) { 1740 /* Special case: outgoing packets have ll header at head */ 1741 skb_pull(skb, skb_network_offset(skb)); 1742 } 1743 } 1744 1745 if (skb->ip_summed == CHECKSUM_PARTIAL) 1746 status |= TP_STATUS_CSUMNOTREADY; 1747 1748 snaplen = skb->len; 1749 1750 res = run_filter(skb, sk, snaplen); 1751 if (!res) 1752 goto drop_n_restore; 1753 if (snaplen > res) 1754 snaplen = res; 1755 1756 if (sk->sk_type == SOCK_DGRAM) { 1757 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1758 po->tp_reserve; 1759 } else { 1760 unsigned int maclen = skb_network_offset(skb); 1761 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1762 (maclen < 16 ? 16 : maclen)) + 1763 po->tp_reserve; 1764 macoff = netoff - maclen; 1765 } 1766 if (po->tp_version <= TPACKET_V2) { 1767 if (macoff + snaplen > po->rx_ring.frame_size) { 1768 if (po->copy_thresh && 1769 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1770 if (skb_shared(skb)) { 1771 copy_skb = skb_clone(skb, GFP_ATOMIC); 1772 } else { 1773 copy_skb = skb_get(skb); 1774 skb_head = skb->data; 1775 } 1776 if (copy_skb) 1777 skb_set_owner_r(copy_skb, sk); 1778 } 1779 snaplen = po->rx_ring.frame_size - macoff; 1780 if ((int)snaplen < 0) 1781 snaplen = 0; 1782 } 1783 } 1784 spin_lock(&sk->sk_receive_queue.lock); 1785 h.raw = packet_current_rx_frame(po, skb, 1786 TP_STATUS_KERNEL, (macoff+snaplen)); 1787 if (!h.raw) 1788 goto ring_is_full; 1789 if (po->tp_version <= TPACKET_V2) { 1790 packet_increment_rx_head(po, &po->rx_ring); 1791 /* 1792 * LOSING will be reported till you read the stats, 1793 * because it's COR - Clear On Read. 1794 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1795 * at packet level. 1796 */ 1797 if (po->stats.tp_drops) 1798 status |= TP_STATUS_LOSING; 1799 } 1800 po->stats.tp_packets++; 1801 if (copy_skb) { 1802 status |= TP_STATUS_COPY; 1803 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1804 } 1805 spin_unlock(&sk->sk_receive_queue.lock); 1806 1807 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1808 1809 switch (po->tp_version) { 1810 case TPACKET_V1: 1811 h.h1->tp_len = skb->len; 1812 h.h1->tp_snaplen = snaplen; 1813 h.h1->tp_mac = macoff; 1814 h.h1->tp_net = netoff; 1815 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1816 && shhwtstamps->syststamp.tv64) 1817 tv = ktime_to_timeval(shhwtstamps->syststamp); 1818 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1819 && shhwtstamps->hwtstamp.tv64) 1820 tv = ktime_to_timeval(shhwtstamps->hwtstamp); 1821 else if (skb->tstamp.tv64) 1822 tv = ktime_to_timeval(skb->tstamp); 1823 else 1824 do_gettimeofday(&tv); 1825 h.h1->tp_sec = tv.tv_sec; 1826 h.h1->tp_usec = tv.tv_usec; 1827 hdrlen = sizeof(*h.h1); 1828 break; 1829 case TPACKET_V2: 1830 h.h2->tp_len = skb->len; 1831 h.h2->tp_snaplen = snaplen; 1832 h.h2->tp_mac = macoff; 1833 h.h2->tp_net = netoff; 1834 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1835 && shhwtstamps->syststamp.tv64) 1836 ts = ktime_to_timespec(shhwtstamps->syststamp); 1837 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1838 && shhwtstamps->hwtstamp.tv64) 1839 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1840 else if (skb->tstamp.tv64) 1841 ts = ktime_to_timespec(skb->tstamp); 1842 else 1843 getnstimeofday(&ts); 1844 h.h2->tp_sec = ts.tv_sec; 1845 h.h2->tp_nsec = ts.tv_nsec; 1846 if (vlan_tx_tag_present(skb)) { 1847 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1848 status |= TP_STATUS_VLAN_VALID; 1849 } else { 1850 h.h2->tp_vlan_tci = 0; 1851 } 1852 h.h2->tp_padding = 0; 1853 hdrlen = sizeof(*h.h2); 1854 break; 1855 case TPACKET_V3: 1856 /* tp_nxt_offset,vlan are already populated above. 1857 * So DONT clear those fields here 1858 */ 1859 h.h3->tp_status |= status; 1860 h.h3->tp_len = skb->len; 1861 h.h3->tp_snaplen = snaplen; 1862 h.h3->tp_mac = macoff; 1863 h.h3->tp_net = netoff; 1864 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1865 && shhwtstamps->syststamp.tv64) 1866 ts = ktime_to_timespec(shhwtstamps->syststamp); 1867 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1868 && shhwtstamps->hwtstamp.tv64) 1869 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1870 else if (skb->tstamp.tv64) 1871 ts = ktime_to_timespec(skb->tstamp); 1872 else 1873 getnstimeofday(&ts); 1874 h.h3->tp_sec = ts.tv_sec; 1875 h.h3->tp_nsec = ts.tv_nsec; 1876 hdrlen = sizeof(*h.h3); 1877 break; 1878 default: 1879 BUG(); 1880 } 1881 1882 sll = h.raw + TPACKET_ALIGN(hdrlen); 1883 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1884 sll->sll_family = AF_PACKET; 1885 sll->sll_hatype = dev->type; 1886 sll->sll_protocol = skb->protocol; 1887 sll->sll_pkttype = skb->pkt_type; 1888 if (unlikely(po->origdev)) 1889 sll->sll_ifindex = orig_dev->ifindex; 1890 else 1891 sll->sll_ifindex = dev->ifindex; 1892 1893 smp_mb(); 1894 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1895 { 1896 u8 *start, *end; 1897 1898 if (po->tp_version <= TPACKET_V2) { 1899 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1900 + macoff + snaplen); 1901 for (start = h.raw; start < end; start += PAGE_SIZE) 1902 flush_dcache_page(pgv_to_page(start)); 1903 } 1904 smp_wmb(); 1905 } 1906 #endif 1907 if (po->tp_version <= TPACKET_V2) 1908 __packet_set_status(po, h.raw, status); 1909 else 1910 prb_clear_blk_fill_status(&po->rx_ring); 1911 1912 sk->sk_data_ready(sk, 0); 1913 1914 drop_n_restore: 1915 if (skb_head != skb->data && skb_shared(skb)) { 1916 skb->data = skb_head; 1917 skb->len = skb_len; 1918 } 1919 drop: 1920 kfree_skb(skb); 1921 return 0; 1922 1923 ring_is_full: 1924 po->stats.tp_drops++; 1925 spin_unlock(&sk->sk_receive_queue.lock); 1926 1927 sk->sk_data_ready(sk, 0); 1928 kfree_skb(copy_skb); 1929 goto drop_n_restore; 1930 } 1931 1932 static void tpacket_destruct_skb(struct sk_buff *skb) 1933 { 1934 struct packet_sock *po = pkt_sk(skb->sk); 1935 void *ph; 1936 1937 if (likely(po->tx_ring.pg_vec)) { 1938 ph = skb_shinfo(skb)->destructor_arg; 1939 BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING); 1940 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1941 atomic_dec(&po->tx_ring.pending); 1942 __packet_set_status(po, ph, TP_STATUS_AVAILABLE); 1943 } 1944 1945 sock_wfree(skb); 1946 } 1947 1948 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1949 void *frame, struct net_device *dev, int size_max, 1950 __be16 proto, unsigned char *addr, int hlen) 1951 { 1952 union { 1953 struct tpacket_hdr *h1; 1954 struct tpacket2_hdr *h2; 1955 void *raw; 1956 } ph; 1957 int to_write, offset, len, tp_len, nr_frags, len_max; 1958 struct socket *sock = po->sk.sk_socket; 1959 struct page *page; 1960 void *data; 1961 int err; 1962 1963 ph.raw = frame; 1964 1965 skb->protocol = proto; 1966 skb->dev = dev; 1967 skb->priority = po->sk.sk_priority; 1968 skb->mark = po->sk.sk_mark; 1969 skb_shinfo(skb)->destructor_arg = ph.raw; 1970 1971 switch (po->tp_version) { 1972 case TPACKET_V2: 1973 tp_len = ph.h2->tp_len; 1974 break; 1975 default: 1976 tp_len = ph.h1->tp_len; 1977 break; 1978 } 1979 if (unlikely(tp_len > size_max)) { 1980 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1981 return -EMSGSIZE; 1982 } 1983 1984 skb_reserve(skb, hlen); 1985 skb_reset_network_header(skb); 1986 1987 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1988 to_write = tp_len; 1989 1990 if (sock->type == SOCK_DGRAM) { 1991 err = dev_hard_header(skb, dev, ntohs(proto), addr, 1992 NULL, tp_len); 1993 if (unlikely(err < 0)) 1994 return -EINVAL; 1995 } else if (dev->hard_header_len) { 1996 /* net device doesn't like empty head */ 1997 if (unlikely(tp_len <= dev->hard_header_len)) { 1998 pr_err("packet size is too short (%d < %d)\n", 1999 tp_len, dev->hard_header_len); 2000 return -EINVAL; 2001 } 2002 2003 skb_push(skb, dev->hard_header_len); 2004 err = skb_store_bits(skb, 0, data, 2005 dev->hard_header_len); 2006 if (unlikely(err)) 2007 return err; 2008 2009 data += dev->hard_header_len; 2010 to_write -= dev->hard_header_len; 2011 } 2012 2013 err = -EFAULT; 2014 offset = offset_in_page(data); 2015 len_max = PAGE_SIZE - offset; 2016 len = ((to_write > len_max) ? len_max : to_write); 2017 2018 skb->data_len = to_write; 2019 skb->len += to_write; 2020 skb->truesize += to_write; 2021 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2022 2023 while (likely(to_write)) { 2024 nr_frags = skb_shinfo(skb)->nr_frags; 2025 2026 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2027 pr_err("Packet exceed the number of skb frags(%lu)\n", 2028 MAX_SKB_FRAGS); 2029 return -EFAULT; 2030 } 2031 2032 page = pgv_to_page(data); 2033 data += len; 2034 flush_dcache_page(page); 2035 get_page(page); 2036 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2037 to_write -= len; 2038 offset = 0; 2039 len_max = PAGE_SIZE; 2040 len = ((to_write > len_max) ? len_max : to_write); 2041 } 2042 2043 return tp_len; 2044 } 2045 2046 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2047 { 2048 struct sk_buff *skb; 2049 struct net_device *dev; 2050 __be16 proto; 2051 bool need_rls_dev = false; 2052 int err, reserve = 0; 2053 void *ph; 2054 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2055 int tp_len, size_max; 2056 unsigned char *addr; 2057 int len_sum = 0; 2058 int status = 0; 2059 int hlen, tlen; 2060 2061 mutex_lock(&po->pg_vec_lock); 2062 2063 err = -EBUSY; 2064 if (saddr == NULL) { 2065 dev = po->prot_hook.dev; 2066 proto = po->num; 2067 addr = NULL; 2068 } else { 2069 err = -EINVAL; 2070 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2071 goto out; 2072 if (msg->msg_namelen < (saddr->sll_halen 2073 + offsetof(struct sockaddr_ll, 2074 sll_addr))) 2075 goto out; 2076 proto = saddr->sll_protocol; 2077 addr = saddr->sll_addr; 2078 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2079 need_rls_dev = true; 2080 } 2081 2082 err = -ENXIO; 2083 if (unlikely(dev == NULL)) 2084 goto out; 2085 2086 reserve = dev->hard_header_len; 2087 2088 err = -ENETDOWN; 2089 if (unlikely(!(dev->flags & IFF_UP))) 2090 goto out_put; 2091 2092 size_max = po->tx_ring.frame_size 2093 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2094 2095 if (size_max > dev->mtu + reserve) 2096 size_max = dev->mtu + reserve; 2097 2098 do { 2099 ph = packet_current_frame(po, &po->tx_ring, 2100 TP_STATUS_SEND_REQUEST); 2101 2102 if (unlikely(ph == NULL)) { 2103 schedule(); 2104 continue; 2105 } 2106 2107 status = TP_STATUS_SEND_REQUEST; 2108 hlen = LL_RESERVED_SPACE(dev); 2109 tlen = dev->needed_tailroom; 2110 skb = sock_alloc_send_skb(&po->sk, 2111 hlen + tlen + sizeof(struct sockaddr_ll), 2112 0, &err); 2113 2114 if (unlikely(skb == NULL)) 2115 goto out_status; 2116 2117 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2118 addr, hlen); 2119 2120 if (unlikely(tp_len < 0)) { 2121 if (po->tp_loss) { 2122 __packet_set_status(po, ph, 2123 TP_STATUS_AVAILABLE); 2124 packet_increment_head(&po->tx_ring); 2125 kfree_skb(skb); 2126 continue; 2127 } else { 2128 status = TP_STATUS_WRONG_FORMAT; 2129 err = tp_len; 2130 goto out_status; 2131 } 2132 } 2133 2134 skb->destructor = tpacket_destruct_skb; 2135 __packet_set_status(po, ph, TP_STATUS_SENDING); 2136 atomic_inc(&po->tx_ring.pending); 2137 2138 status = TP_STATUS_SEND_REQUEST; 2139 err = dev_queue_xmit(skb); 2140 if (unlikely(err > 0)) { 2141 err = net_xmit_errno(err); 2142 if (err && __packet_get_status(po, ph) == 2143 TP_STATUS_AVAILABLE) { 2144 /* skb was destructed already */ 2145 skb = NULL; 2146 goto out_status; 2147 } 2148 /* 2149 * skb was dropped but not destructed yet; 2150 * let's treat it like congestion or err < 0 2151 */ 2152 err = 0; 2153 } 2154 packet_increment_head(&po->tx_ring); 2155 len_sum += tp_len; 2156 } while (likely((ph != NULL) || 2157 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2158 (atomic_read(&po->tx_ring.pending)))) 2159 ); 2160 2161 err = len_sum; 2162 goto out_put; 2163 2164 out_status: 2165 __packet_set_status(po, ph, status); 2166 kfree_skb(skb); 2167 out_put: 2168 if (need_rls_dev) 2169 dev_put(dev); 2170 out: 2171 mutex_unlock(&po->pg_vec_lock); 2172 return err; 2173 } 2174 2175 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2176 size_t reserve, size_t len, 2177 size_t linear, int noblock, 2178 int *err) 2179 { 2180 struct sk_buff *skb; 2181 2182 /* Under a page? Don't bother with paged skb. */ 2183 if (prepad + len < PAGE_SIZE || !linear) 2184 linear = len; 2185 2186 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2187 err); 2188 if (!skb) 2189 return NULL; 2190 2191 skb_reserve(skb, reserve); 2192 skb_put(skb, linear); 2193 skb->data_len = len - linear; 2194 skb->len += len - linear; 2195 2196 return skb; 2197 } 2198 2199 static int packet_snd(struct socket *sock, 2200 struct msghdr *msg, size_t len) 2201 { 2202 struct sock *sk = sock->sk; 2203 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2204 struct sk_buff *skb; 2205 struct net_device *dev; 2206 __be16 proto; 2207 bool need_rls_dev = false; 2208 unsigned char *addr; 2209 int err, reserve = 0; 2210 struct virtio_net_hdr vnet_hdr = { 0 }; 2211 int offset = 0; 2212 int vnet_hdr_len; 2213 struct packet_sock *po = pkt_sk(sk); 2214 unsigned short gso_type = 0; 2215 int hlen, tlen; 2216 int extra_len = 0; 2217 2218 /* 2219 * Get and verify the address. 2220 */ 2221 2222 if (saddr == NULL) { 2223 dev = po->prot_hook.dev; 2224 proto = po->num; 2225 addr = NULL; 2226 } else { 2227 err = -EINVAL; 2228 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2229 goto out; 2230 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2231 goto out; 2232 proto = saddr->sll_protocol; 2233 addr = saddr->sll_addr; 2234 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2235 need_rls_dev = true; 2236 } 2237 2238 err = -ENXIO; 2239 if (dev == NULL) 2240 goto out_unlock; 2241 if (sock->type == SOCK_RAW) 2242 reserve = dev->hard_header_len; 2243 2244 err = -ENETDOWN; 2245 if (!(dev->flags & IFF_UP)) 2246 goto out_unlock; 2247 2248 if (po->has_vnet_hdr) { 2249 vnet_hdr_len = sizeof(vnet_hdr); 2250 2251 err = -EINVAL; 2252 if (len < vnet_hdr_len) 2253 goto out_unlock; 2254 2255 len -= vnet_hdr_len; 2256 2257 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2258 vnet_hdr_len); 2259 if (err < 0) 2260 goto out_unlock; 2261 2262 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2263 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2264 vnet_hdr.hdr_len)) 2265 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2266 vnet_hdr.csum_offset + 2; 2267 2268 err = -EINVAL; 2269 if (vnet_hdr.hdr_len > len) 2270 goto out_unlock; 2271 2272 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2273 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2274 case VIRTIO_NET_HDR_GSO_TCPV4: 2275 gso_type = SKB_GSO_TCPV4; 2276 break; 2277 case VIRTIO_NET_HDR_GSO_TCPV6: 2278 gso_type = SKB_GSO_TCPV6; 2279 break; 2280 case VIRTIO_NET_HDR_GSO_UDP: 2281 gso_type = SKB_GSO_UDP; 2282 break; 2283 default: 2284 goto out_unlock; 2285 } 2286 2287 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2288 gso_type |= SKB_GSO_TCP_ECN; 2289 2290 if (vnet_hdr.gso_size == 0) 2291 goto out_unlock; 2292 2293 } 2294 } 2295 2296 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2297 if (!netif_supports_nofcs(dev)) { 2298 err = -EPROTONOSUPPORT; 2299 goto out_unlock; 2300 } 2301 extra_len = 4; /* We're doing our own CRC */ 2302 } 2303 2304 err = -EMSGSIZE; 2305 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2306 goto out_unlock; 2307 2308 err = -ENOBUFS; 2309 hlen = LL_RESERVED_SPACE(dev); 2310 tlen = dev->needed_tailroom; 2311 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2312 msg->msg_flags & MSG_DONTWAIT, &err); 2313 if (skb == NULL) 2314 goto out_unlock; 2315 2316 skb_set_network_header(skb, reserve); 2317 2318 err = -EINVAL; 2319 if (sock->type == SOCK_DGRAM && 2320 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2321 goto out_free; 2322 2323 /* Returns -EFAULT on error */ 2324 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2325 if (err) 2326 goto out_free; 2327 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2328 if (err < 0) 2329 goto out_free; 2330 2331 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2332 /* Earlier code assumed this would be a VLAN pkt, 2333 * double-check this now that we have the actual 2334 * packet in hand. 2335 */ 2336 struct ethhdr *ehdr; 2337 skb_reset_mac_header(skb); 2338 ehdr = eth_hdr(skb); 2339 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2340 err = -EMSGSIZE; 2341 goto out_free; 2342 } 2343 } 2344 2345 skb->protocol = proto; 2346 skb->dev = dev; 2347 skb->priority = sk->sk_priority; 2348 skb->mark = sk->sk_mark; 2349 2350 if (po->has_vnet_hdr) { 2351 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2352 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2353 vnet_hdr.csum_offset)) { 2354 err = -EINVAL; 2355 goto out_free; 2356 } 2357 } 2358 2359 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2360 skb_shinfo(skb)->gso_type = gso_type; 2361 2362 /* Header must be checked, and gso_segs computed. */ 2363 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2364 skb_shinfo(skb)->gso_segs = 0; 2365 2366 len += vnet_hdr_len; 2367 } 2368 2369 if (unlikely(extra_len == 4)) 2370 skb->no_fcs = 1; 2371 2372 /* 2373 * Now send it 2374 */ 2375 2376 err = dev_queue_xmit(skb); 2377 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2378 goto out_unlock; 2379 2380 if (need_rls_dev) 2381 dev_put(dev); 2382 2383 return len; 2384 2385 out_free: 2386 kfree_skb(skb); 2387 out_unlock: 2388 if (dev && need_rls_dev) 2389 dev_put(dev); 2390 out: 2391 return err; 2392 } 2393 2394 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2395 struct msghdr *msg, size_t len) 2396 { 2397 struct sock *sk = sock->sk; 2398 struct packet_sock *po = pkt_sk(sk); 2399 if (po->tx_ring.pg_vec) 2400 return tpacket_snd(po, msg); 2401 else 2402 return packet_snd(sock, msg, len); 2403 } 2404 2405 /* 2406 * Close a PACKET socket. This is fairly simple. We immediately go 2407 * to 'closed' state and remove our protocol entry in the device list. 2408 */ 2409 2410 static int packet_release(struct socket *sock) 2411 { 2412 struct sock *sk = sock->sk; 2413 struct packet_sock *po; 2414 struct net *net; 2415 union tpacket_req_u req_u; 2416 2417 if (!sk) 2418 return 0; 2419 2420 net = sock_net(sk); 2421 po = pkt_sk(sk); 2422 2423 spin_lock_bh(&net->packet.sklist_lock); 2424 sk_del_node_init_rcu(sk); 2425 sock_prot_inuse_add(net, sk->sk_prot, -1); 2426 spin_unlock_bh(&net->packet.sklist_lock); 2427 2428 spin_lock(&po->bind_lock); 2429 unregister_prot_hook(sk, false); 2430 if (po->prot_hook.dev) { 2431 dev_put(po->prot_hook.dev); 2432 po->prot_hook.dev = NULL; 2433 } 2434 spin_unlock(&po->bind_lock); 2435 2436 packet_flush_mclist(sk); 2437 2438 memset(&req_u, 0, sizeof(req_u)); 2439 2440 if (po->rx_ring.pg_vec) 2441 packet_set_ring(sk, &req_u, 1, 0); 2442 2443 if (po->tx_ring.pg_vec) 2444 packet_set_ring(sk, &req_u, 1, 1); 2445 2446 fanout_release(sk); 2447 2448 synchronize_net(); 2449 /* 2450 * Now the socket is dead. No more input will appear. 2451 */ 2452 sock_orphan(sk); 2453 sock->sk = NULL; 2454 2455 /* Purge queues */ 2456 2457 skb_queue_purge(&sk->sk_receive_queue); 2458 sk_refcnt_debug_release(sk); 2459 2460 sock_put(sk); 2461 return 0; 2462 } 2463 2464 /* 2465 * Attach a packet hook. 2466 */ 2467 2468 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2469 { 2470 struct packet_sock *po = pkt_sk(sk); 2471 2472 if (po->fanout) { 2473 if (dev) 2474 dev_put(dev); 2475 2476 return -EINVAL; 2477 } 2478 2479 lock_sock(sk); 2480 2481 spin_lock(&po->bind_lock); 2482 unregister_prot_hook(sk, true); 2483 po->num = protocol; 2484 po->prot_hook.type = protocol; 2485 if (po->prot_hook.dev) 2486 dev_put(po->prot_hook.dev); 2487 po->prot_hook.dev = dev; 2488 2489 po->ifindex = dev ? dev->ifindex : 0; 2490 2491 if (protocol == 0) 2492 goto out_unlock; 2493 2494 if (!dev || (dev->flags & IFF_UP)) { 2495 register_prot_hook(sk); 2496 } else { 2497 sk->sk_err = ENETDOWN; 2498 if (!sock_flag(sk, SOCK_DEAD)) 2499 sk->sk_error_report(sk); 2500 } 2501 2502 out_unlock: 2503 spin_unlock(&po->bind_lock); 2504 release_sock(sk); 2505 return 0; 2506 } 2507 2508 /* 2509 * Bind a packet socket to a device 2510 */ 2511 2512 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2513 int addr_len) 2514 { 2515 struct sock *sk = sock->sk; 2516 char name[15]; 2517 struct net_device *dev; 2518 int err = -ENODEV; 2519 2520 /* 2521 * Check legality 2522 */ 2523 2524 if (addr_len != sizeof(struct sockaddr)) 2525 return -EINVAL; 2526 strlcpy(name, uaddr->sa_data, sizeof(name)); 2527 2528 dev = dev_get_by_name(sock_net(sk), name); 2529 if (dev) 2530 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2531 return err; 2532 } 2533 2534 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2535 { 2536 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2537 struct sock *sk = sock->sk; 2538 struct net_device *dev = NULL; 2539 int err; 2540 2541 2542 /* 2543 * Check legality 2544 */ 2545 2546 if (addr_len < sizeof(struct sockaddr_ll)) 2547 return -EINVAL; 2548 if (sll->sll_family != AF_PACKET) 2549 return -EINVAL; 2550 2551 if (sll->sll_ifindex) { 2552 err = -ENODEV; 2553 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2554 if (dev == NULL) 2555 goto out; 2556 } 2557 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2558 2559 out: 2560 return err; 2561 } 2562 2563 static struct proto packet_proto = { 2564 .name = "PACKET", 2565 .owner = THIS_MODULE, 2566 .obj_size = sizeof(struct packet_sock), 2567 }; 2568 2569 /* 2570 * Create a packet of type SOCK_PACKET. 2571 */ 2572 2573 static int packet_create(struct net *net, struct socket *sock, int protocol, 2574 int kern) 2575 { 2576 struct sock *sk; 2577 struct packet_sock *po; 2578 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2579 int err; 2580 2581 if (!capable(CAP_NET_RAW)) 2582 return -EPERM; 2583 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2584 sock->type != SOCK_PACKET) 2585 return -ESOCKTNOSUPPORT; 2586 2587 sock->state = SS_UNCONNECTED; 2588 2589 err = -ENOBUFS; 2590 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2591 if (sk == NULL) 2592 goto out; 2593 2594 sock->ops = &packet_ops; 2595 if (sock->type == SOCK_PACKET) 2596 sock->ops = &packet_ops_spkt; 2597 2598 sock_init_data(sock, sk); 2599 2600 po = pkt_sk(sk); 2601 sk->sk_family = PF_PACKET; 2602 po->num = proto; 2603 2604 sk->sk_destruct = packet_sock_destruct; 2605 sk_refcnt_debug_inc(sk); 2606 2607 /* 2608 * Attach a protocol block 2609 */ 2610 2611 spin_lock_init(&po->bind_lock); 2612 mutex_init(&po->pg_vec_lock); 2613 po->prot_hook.func = packet_rcv; 2614 2615 if (sock->type == SOCK_PACKET) 2616 po->prot_hook.func = packet_rcv_spkt; 2617 2618 po->prot_hook.af_packet_priv = sk; 2619 2620 if (proto) { 2621 po->prot_hook.type = proto; 2622 register_prot_hook(sk); 2623 } 2624 2625 spin_lock_bh(&net->packet.sklist_lock); 2626 sk_add_node_rcu(sk, &net->packet.sklist); 2627 sock_prot_inuse_add(net, &packet_proto, 1); 2628 spin_unlock_bh(&net->packet.sklist_lock); 2629 2630 return 0; 2631 out: 2632 return err; 2633 } 2634 2635 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2636 { 2637 struct sock_exterr_skb *serr; 2638 struct sk_buff *skb, *skb2; 2639 int copied, err; 2640 2641 err = -EAGAIN; 2642 skb = skb_dequeue(&sk->sk_error_queue); 2643 if (skb == NULL) 2644 goto out; 2645 2646 copied = skb->len; 2647 if (copied > len) { 2648 msg->msg_flags |= MSG_TRUNC; 2649 copied = len; 2650 } 2651 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2652 if (err) 2653 goto out_free_skb; 2654 2655 sock_recv_timestamp(msg, sk, skb); 2656 2657 serr = SKB_EXT_ERR(skb); 2658 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2659 sizeof(serr->ee), &serr->ee); 2660 2661 msg->msg_flags |= MSG_ERRQUEUE; 2662 err = copied; 2663 2664 /* Reset and regenerate socket error */ 2665 spin_lock_bh(&sk->sk_error_queue.lock); 2666 sk->sk_err = 0; 2667 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2668 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2669 spin_unlock_bh(&sk->sk_error_queue.lock); 2670 sk->sk_error_report(sk); 2671 } else 2672 spin_unlock_bh(&sk->sk_error_queue.lock); 2673 2674 out_free_skb: 2675 kfree_skb(skb); 2676 out: 2677 return err; 2678 } 2679 2680 /* 2681 * Pull a packet from our receive queue and hand it to the user. 2682 * If necessary we block. 2683 */ 2684 2685 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2686 struct msghdr *msg, size_t len, int flags) 2687 { 2688 struct sock *sk = sock->sk; 2689 struct sk_buff *skb; 2690 int copied, err; 2691 struct sockaddr_ll *sll; 2692 int vnet_hdr_len = 0; 2693 2694 err = -EINVAL; 2695 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2696 goto out; 2697 2698 #if 0 2699 /* What error should we return now? EUNATTACH? */ 2700 if (pkt_sk(sk)->ifindex < 0) 2701 return -ENODEV; 2702 #endif 2703 2704 if (flags & MSG_ERRQUEUE) { 2705 err = packet_recv_error(sk, msg, len); 2706 goto out; 2707 } 2708 2709 /* 2710 * Call the generic datagram receiver. This handles all sorts 2711 * of horrible races and re-entrancy so we can forget about it 2712 * in the protocol layers. 2713 * 2714 * Now it will return ENETDOWN, if device have just gone down, 2715 * but then it will block. 2716 */ 2717 2718 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2719 2720 /* 2721 * An error occurred so return it. Because skb_recv_datagram() 2722 * handles the blocking we don't see and worry about blocking 2723 * retries. 2724 */ 2725 2726 if (skb == NULL) 2727 goto out; 2728 2729 if (pkt_sk(sk)->has_vnet_hdr) { 2730 struct virtio_net_hdr vnet_hdr = { 0 }; 2731 2732 err = -EINVAL; 2733 vnet_hdr_len = sizeof(vnet_hdr); 2734 if (len < vnet_hdr_len) 2735 goto out_free; 2736 2737 len -= vnet_hdr_len; 2738 2739 if (skb_is_gso(skb)) { 2740 struct skb_shared_info *sinfo = skb_shinfo(skb); 2741 2742 /* This is a hint as to how much should be linear. */ 2743 vnet_hdr.hdr_len = skb_headlen(skb); 2744 vnet_hdr.gso_size = sinfo->gso_size; 2745 if (sinfo->gso_type & SKB_GSO_TCPV4) 2746 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2747 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2748 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2749 else if (sinfo->gso_type & SKB_GSO_UDP) 2750 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2751 else if (sinfo->gso_type & SKB_GSO_FCOE) 2752 goto out_free; 2753 else 2754 BUG(); 2755 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2756 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2757 } else 2758 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2759 2760 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2761 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2762 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2763 vnet_hdr.csum_offset = skb->csum_offset; 2764 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2765 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2766 } /* else everything is zero */ 2767 2768 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2769 vnet_hdr_len); 2770 if (err < 0) 2771 goto out_free; 2772 } 2773 2774 /* 2775 * If the address length field is there to be filled in, we fill 2776 * it in now. 2777 */ 2778 2779 sll = &PACKET_SKB_CB(skb)->sa.ll; 2780 if (sock->type == SOCK_PACKET) 2781 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2782 else 2783 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2784 2785 /* 2786 * You lose any data beyond the buffer you gave. If it worries a 2787 * user program they can ask the device for its MTU anyway. 2788 */ 2789 2790 copied = skb->len; 2791 if (copied > len) { 2792 copied = len; 2793 msg->msg_flags |= MSG_TRUNC; 2794 } 2795 2796 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2797 if (err) 2798 goto out_free; 2799 2800 sock_recv_ts_and_drops(msg, sk, skb); 2801 2802 if (msg->msg_name) 2803 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2804 msg->msg_namelen); 2805 2806 if (pkt_sk(sk)->auxdata) { 2807 struct tpacket_auxdata aux; 2808 2809 aux.tp_status = TP_STATUS_USER; 2810 if (skb->ip_summed == CHECKSUM_PARTIAL) 2811 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2812 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2813 aux.tp_snaplen = skb->len; 2814 aux.tp_mac = 0; 2815 aux.tp_net = skb_network_offset(skb); 2816 if (vlan_tx_tag_present(skb)) { 2817 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2818 aux.tp_status |= TP_STATUS_VLAN_VALID; 2819 } else { 2820 aux.tp_vlan_tci = 0; 2821 } 2822 aux.tp_padding = 0; 2823 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2824 } 2825 2826 /* 2827 * Free or return the buffer as appropriate. Again this 2828 * hides all the races and re-entrancy issues from us. 2829 */ 2830 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2831 2832 out_free: 2833 skb_free_datagram(sk, skb); 2834 out: 2835 return err; 2836 } 2837 2838 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2839 int *uaddr_len, int peer) 2840 { 2841 struct net_device *dev; 2842 struct sock *sk = sock->sk; 2843 2844 if (peer) 2845 return -EOPNOTSUPP; 2846 2847 uaddr->sa_family = AF_PACKET; 2848 rcu_read_lock(); 2849 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2850 if (dev) 2851 strncpy(uaddr->sa_data, dev->name, 14); 2852 else 2853 memset(uaddr->sa_data, 0, 14); 2854 rcu_read_unlock(); 2855 *uaddr_len = sizeof(*uaddr); 2856 2857 return 0; 2858 } 2859 2860 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2861 int *uaddr_len, int peer) 2862 { 2863 struct net_device *dev; 2864 struct sock *sk = sock->sk; 2865 struct packet_sock *po = pkt_sk(sk); 2866 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2867 2868 if (peer) 2869 return -EOPNOTSUPP; 2870 2871 sll->sll_family = AF_PACKET; 2872 sll->sll_ifindex = po->ifindex; 2873 sll->sll_protocol = po->num; 2874 sll->sll_pkttype = 0; 2875 rcu_read_lock(); 2876 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2877 if (dev) { 2878 sll->sll_hatype = dev->type; 2879 sll->sll_halen = dev->addr_len; 2880 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2881 } else { 2882 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2883 sll->sll_halen = 0; 2884 } 2885 rcu_read_unlock(); 2886 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2887 2888 return 0; 2889 } 2890 2891 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2892 int what) 2893 { 2894 switch (i->type) { 2895 case PACKET_MR_MULTICAST: 2896 if (i->alen != dev->addr_len) 2897 return -EINVAL; 2898 if (what > 0) 2899 return dev_mc_add(dev, i->addr); 2900 else 2901 return dev_mc_del(dev, i->addr); 2902 break; 2903 case PACKET_MR_PROMISC: 2904 return dev_set_promiscuity(dev, what); 2905 break; 2906 case PACKET_MR_ALLMULTI: 2907 return dev_set_allmulti(dev, what); 2908 break; 2909 case PACKET_MR_UNICAST: 2910 if (i->alen != dev->addr_len) 2911 return -EINVAL; 2912 if (what > 0) 2913 return dev_uc_add(dev, i->addr); 2914 else 2915 return dev_uc_del(dev, i->addr); 2916 break; 2917 default: 2918 break; 2919 } 2920 return 0; 2921 } 2922 2923 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2924 { 2925 for ( ; i; i = i->next) { 2926 if (i->ifindex == dev->ifindex) 2927 packet_dev_mc(dev, i, what); 2928 } 2929 } 2930 2931 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2932 { 2933 struct packet_sock *po = pkt_sk(sk); 2934 struct packet_mclist *ml, *i; 2935 struct net_device *dev; 2936 int err; 2937 2938 rtnl_lock(); 2939 2940 err = -ENODEV; 2941 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2942 if (!dev) 2943 goto done; 2944 2945 err = -EINVAL; 2946 if (mreq->mr_alen > dev->addr_len) 2947 goto done; 2948 2949 err = -ENOBUFS; 2950 i = kmalloc(sizeof(*i), GFP_KERNEL); 2951 if (i == NULL) 2952 goto done; 2953 2954 err = 0; 2955 for (ml = po->mclist; ml; ml = ml->next) { 2956 if (ml->ifindex == mreq->mr_ifindex && 2957 ml->type == mreq->mr_type && 2958 ml->alen == mreq->mr_alen && 2959 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2960 ml->count++; 2961 /* Free the new element ... */ 2962 kfree(i); 2963 goto done; 2964 } 2965 } 2966 2967 i->type = mreq->mr_type; 2968 i->ifindex = mreq->mr_ifindex; 2969 i->alen = mreq->mr_alen; 2970 memcpy(i->addr, mreq->mr_address, i->alen); 2971 i->count = 1; 2972 i->next = po->mclist; 2973 po->mclist = i; 2974 err = packet_dev_mc(dev, i, 1); 2975 if (err) { 2976 po->mclist = i->next; 2977 kfree(i); 2978 } 2979 2980 done: 2981 rtnl_unlock(); 2982 return err; 2983 } 2984 2985 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2986 { 2987 struct packet_mclist *ml, **mlp; 2988 2989 rtnl_lock(); 2990 2991 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 2992 if (ml->ifindex == mreq->mr_ifindex && 2993 ml->type == mreq->mr_type && 2994 ml->alen == mreq->mr_alen && 2995 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2996 if (--ml->count == 0) { 2997 struct net_device *dev; 2998 *mlp = ml->next; 2999 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3000 if (dev) 3001 packet_dev_mc(dev, ml, -1); 3002 kfree(ml); 3003 } 3004 rtnl_unlock(); 3005 return 0; 3006 } 3007 } 3008 rtnl_unlock(); 3009 return -EADDRNOTAVAIL; 3010 } 3011 3012 static void packet_flush_mclist(struct sock *sk) 3013 { 3014 struct packet_sock *po = pkt_sk(sk); 3015 struct packet_mclist *ml; 3016 3017 if (!po->mclist) 3018 return; 3019 3020 rtnl_lock(); 3021 while ((ml = po->mclist) != NULL) { 3022 struct net_device *dev; 3023 3024 po->mclist = ml->next; 3025 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3026 if (dev != NULL) 3027 packet_dev_mc(dev, ml, -1); 3028 kfree(ml); 3029 } 3030 rtnl_unlock(); 3031 } 3032 3033 static int 3034 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3035 { 3036 struct sock *sk = sock->sk; 3037 struct packet_sock *po = pkt_sk(sk); 3038 int ret; 3039 3040 if (level != SOL_PACKET) 3041 return -ENOPROTOOPT; 3042 3043 switch (optname) { 3044 case PACKET_ADD_MEMBERSHIP: 3045 case PACKET_DROP_MEMBERSHIP: 3046 { 3047 struct packet_mreq_max mreq; 3048 int len = optlen; 3049 memset(&mreq, 0, sizeof(mreq)); 3050 if (len < sizeof(struct packet_mreq)) 3051 return -EINVAL; 3052 if (len > sizeof(mreq)) 3053 len = sizeof(mreq); 3054 if (copy_from_user(&mreq, optval, len)) 3055 return -EFAULT; 3056 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3057 return -EINVAL; 3058 if (optname == PACKET_ADD_MEMBERSHIP) 3059 ret = packet_mc_add(sk, &mreq); 3060 else 3061 ret = packet_mc_drop(sk, &mreq); 3062 return ret; 3063 } 3064 3065 case PACKET_RX_RING: 3066 case PACKET_TX_RING: 3067 { 3068 union tpacket_req_u req_u; 3069 int len; 3070 3071 switch (po->tp_version) { 3072 case TPACKET_V1: 3073 case TPACKET_V2: 3074 len = sizeof(req_u.req); 3075 break; 3076 case TPACKET_V3: 3077 default: 3078 len = sizeof(req_u.req3); 3079 break; 3080 } 3081 if (optlen < len) 3082 return -EINVAL; 3083 if (pkt_sk(sk)->has_vnet_hdr) 3084 return -EINVAL; 3085 if (copy_from_user(&req_u.req, optval, len)) 3086 return -EFAULT; 3087 return packet_set_ring(sk, &req_u, 0, 3088 optname == PACKET_TX_RING); 3089 } 3090 case PACKET_COPY_THRESH: 3091 { 3092 int val; 3093 3094 if (optlen != sizeof(val)) 3095 return -EINVAL; 3096 if (copy_from_user(&val, optval, sizeof(val))) 3097 return -EFAULT; 3098 3099 pkt_sk(sk)->copy_thresh = val; 3100 return 0; 3101 } 3102 case PACKET_VERSION: 3103 { 3104 int val; 3105 3106 if (optlen != sizeof(val)) 3107 return -EINVAL; 3108 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3109 return -EBUSY; 3110 if (copy_from_user(&val, optval, sizeof(val))) 3111 return -EFAULT; 3112 switch (val) { 3113 case TPACKET_V1: 3114 case TPACKET_V2: 3115 case TPACKET_V3: 3116 po->tp_version = val; 3117 return 0; 3118 default: 3119 return -EINVAL; 3120 } 3121 } 3122 case PACKET_RESERVE: 3123 { 3124 unsigned int val; 3125 3126 if (optlen != sizeof(val)) 3127 return -EINVAL; 3128 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3129 return -EBUSY; 3130 if (copy_from_user(&val, optval, sizeof(val))) 3131 return -EFAULT; 3132 po->tp_reserve = val; 3133 return 0; 3134 } 3135 case PACKET_LOSS: 3136 { 3137 unsigned int val; 3138 3139 if (optlen != sizeof(val)) 3140 return -EINVAL; 3141 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3142 return -EBUSY; 3143 if (copy_from_user(&val, optval, sizeof(val))) 3144 return -EFAULT; 3145 po->tp_loss = !!val; 3146 return 0; 3147 } 3148 case PACKET_AUXDATA: 3149 { 3150 int val; 3151 3152 if (optlen < sizeof(val)) 3153 return -EINVAL; 3154 if (copy_from_user(&val, optval, sizeof(val))) 3155 return -EFAULT; 3156 3157 po->auxdata = !!val; 3158 return 0; 3159 } 3160 case PACKET_ORIGDEV: 3161 { 3162 int val; 3163 3164 if (optlen < sizeof(val)) 3165 return -EINVAL; 3166 if (copy_from_user(&val, optval, sizeof(val))) 3167 return -EFAULT; 3168 3169 po->origdev = !!val; 3170 return 0; 3171 } 3172 case PACKET_VNET_HDR: 3173 { 3174 int val; 3175 3176 if (sock->type != SOCK_RAW) 3177 return -EINVAL; 3178 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3179 return -EBUSY; 3180 if (optlen < sizeof(val)) 3181 return -EINVAL; 3182 if (copy_from_user(&val, optval, sizeof(val))) 3183 return -EFAULT; 3184 3185 po->has_vnet_hdr = !!val; 3186 return 0; 3187 } 3188 case PACKET_TIMESTAMP: 3189 { 3190 int val; 3191 3192 if (optlen != sizeof(val)) 3193 return -EINVAL; 3194 if (copy_from_user(&val, optval, sizeof(val))) 3195 return -EFAULT; 3196 3197 po->tp_tstamp = val; 3198 return 0; 3199 } 3200 case PACKET_FANOUT: 3201 { 3202 int val; 3203 3204 if (optlen != sizeof(val)) 3205 return -EINVAL; 3206 if (copy_from_user(&val, optval, sizeof(val))) 3207 return -EFAULT; 3208 3209 return fanout_add(sk, val & 0xffff, val >> 16); 3210 } 3211 default: 3212 return -ENOPROTOOPT; 3213 } 3214 } 3215 3216 static int packet_getsockopt(struct socket *sock, int level, int optname, 3217 char __user *optval, int __user *optlen) 3218 { 3219 int len; 3220 int val, lv = sizeof(val); 3221 struct sock *sk = sock->sk; 3222 struct packet_sock *po = pkt_sk(sk); 3223 void *data = &val; 3224 struct tpacket_stats st; 3225 union tpacket_stats_u st_u; 3226 3227 if (level != SOL_PACKET) 3228 return -ENOPROTOOPT; 3229 3230 if (get_user(len, optlen)) 3231 return -EFAULT; 3232 3233 if (len < 0) 3234 return -EINVAL; 3235 3236 switch (optname) { 3237 case PACKET_STATISTICS: 3238 spin_lock_bh(&sk->sk_receive_queue.lock); 3239 if (po->tp_version == TPACKET_V3) { 3240 lv = sizeof(struct tpacket_stats_v3); 3241 memcpy(&st_u.stats3, &po->stats, 3242 sizeof(struct tpacket_stats)); 3243 st_u.stats3.tp_freeze_q_cnt = 3244 po->stats_u.stats3.tp_freeze_q_cnt; 3245 st_u.stats3.tp_packets += po->stats.tp_drops; 3246 data = &st_u.stats3; 3247 } else { 3248 lv = sizeof(struct tpacket_stats); 3249 st = po->stats; 3250 st.tp_packets += st.tp_drops; 3251 data = &st; 3252 } 3253 memset(&po->stats, 0, sizeof(st)); 3254 spin_unlock_bh(&sk->sk_receive_queue.lock); 3255 break; 3256 case PACKET_AUXDATA: 3257 val = po->auxdata; 3258 break; 3259 case PACKET_ORIGDEV: 3260 val = po->origdev; 3261 break; 3262 case PACKET_VNET_HDR: 3263 val = po->has_vnet_hdr; 3264 break; 3265 case PACKET_VERSION: 3266 val = po->tp_version; 3267 break; 3268 case PACKET_HDRLEN: 3269 if (len > sizeof(int)) 3270 len = sizeof(int); 3271 if (copy_from_user(&val, optval, len)) 3272 return -EFAULT; 3273 switch (val) { 3274 case TPACKET_V1: 3275 val = sizeof(struct tpacket_hdr); 3276 break; 3277 case TPACKET_V2: 3278 val = sizeof(struct tpacket2_hdr); 3279 break; 3280 case TPACKET_V3: 3281 val = sizeof(struct tpacket3_hdr); 3282 break; 3283 default: 3284 return -EINVAL; 3285 } 3286 break; 3287 case PACKET_RESERVE: 3288 val = po->tp_reserve; 3289 break; 3290 case PACKET_LOSS: 3291 val = po->tp_loss; 3292 break; 3293 case PACKET_TIMESTAMP: 3294 val = po->tp_tstamp; 3295 break; 3296 case PACKET_FANOUT: 3297 val = (po->fanout ? 3298 ((u32)po->fanout->id | 3299 ((u32)po->fanout->type << 16)) : 3300 0); 3301 break; 3302 default: 3303 return -ENOPROTOOPT; 3304 } 3305 3306 if (len > lv) 3307 len = lv; 3308 if (put_user(len, optlen)) 3309 return -EFAULT; 3310 if (copy_to_user(optval, data, len)) 3311 return -EFAULT; 3312 return 0; 3313 } 3314 3315 3316 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3317 { 3318 struct sock *sk; 3319 struct hlist_node *node; 3320 struct net_device *dev = data; 3321 struct net *net = dev_net(dev); 3322 3323 rcu_read_lock(); 3324 sk_for_each_rcu(sk, node, &net->packet.sklist) { 3325 struct packet_sock *po = pkt_sk(sk); 3326 3327 switch (msg) { 3328 case NETDEV_UNREGISTER: 3329 if (po->mclist) 3330 packet_dev_mclist(dev, po->mclist, -1); 3331 /* fallthrough */ 3332 3333 case NETDEV_DOWN: 3334 if (dev->ifindex == po->ifindex) { 3335 spin_lock(&po->bind_lock); 3336 if (po->running) { 3337 __unregister_prot_hook(sk, false); 3338 sk->sk_err = ENETDOWN; 3339 if (!sock_flag(sk, SOCK_DEAD)) 3340 sk->sk_error_report(sk); 3341 } 3342 if (msg == NETDEV_UNREGISTER) { 3343 po->ifindex = -1; 3344 if (po->prot_hook.dev) 3345 dev_put(po->prot_hook.dev); 3346 po->prot_hook.dev = NULL; 3347 } 3348 spin_unlock(&po->bind_lock); 3349 } 3350 break; 3351 case NETDEV_UP: 3352 if (dev->ifindex == po->ifindex) { 3353 spin_lock(&po->bind_lock); 3354 if (po->num) 3355 register_prot_hook(sk); 3356 spin_unlock(&po->bind_lock); 3357 } 3358 break; 3359 } 3360 } 3361 rcu_read_unlock(); 3362 return NOTIFY_DONE; 3363 } 3364 3365 3366 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3367 unsigned long arg) 3368 { 3369 struct sock *sk = sock->sk; 3370 3371 switch (cmd) { 3372 case SIOCOUTQ: 3373 { 3374 int amount = sk_wmem_alloc_get(sk); 3375 3376 return put_user(amount, (int __user *)arg); 3377 } 3378 case SIOCINQ: 3379 { 3380 struct sk_buff *skb; 3381 int amount = 0; 3382 3383 spin_lock_bh(&sk->sk_receive_queue.lock); 3384 skb = skb_peek(&sk->sk_receive_queue); 3385 if (skb) 3386 amount = skb->len; 3387 spin_unlock_bh(&sk->sk_receive_queue.lock); 3388 return put_user(amount, (int __user *)arg); 3389 } 3390 case SIOCGSTAMP: 3391 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3392 case SIOCGSTAMPNS: 3393 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3394 3395 #ifdef CONFIG_INET 3396 case SIOCADDRT: 3397 case SIOCDELRT: 3398 case SIOCDARP: 3399 case SIOCGARP: 3400 case SIOCSARP: 3401 case SIOCGIFADDR: 3402 case SIOCSIFADDR: 3403 case SIOCGIFBRDADDR: 3404 case SIOCSIFBRDADDR: 3405 case SIOCGIFNETMASK: 3406 case SIOCSIFNETMASK: 3407 case SIOCGIFDSTADDR: 3408 case SIOCSIFDSTADDR: 3409 case SIOCSIFFLAGS: 3410 return inet_dgram_ops.ioctl(sock, cmd, arg); 3411 #endif 3412 3413 default: 3414 return -ENOIOCTLCMD; 3415 } 3416 return 0; 3417 } 3418 3419 static unsigned int packet_poll(struct file *file, struct socket *sock, 3420 poll_table *wait) 3421 { 3422 struct sock *sk = sock->sk; 3423 struct packet_sock *po = pkt_sk(sk); 3424 unsigned int mask = datagram_poll(file, sock, wait); 3425 3426 spin_lock_bh(&sk->sk_receive_queue.lock); 3427 if (po->rx_ring.pg_vec) { 3428 if (!packet_previous_rx_frame(po, &po->rx_ring, 3429 TP_STATUS_KERNEL)) 3430 mask |= POLLIN | POLLRDNORM; 3431 } 3432 spin_unlock_bh(&sk->sk_receive_queue.lock); 3433 spin_lock_bh(&sk->sk_write_queue.lock); 3434 if (po->tx_ring.pg_vec) { 3435 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3436 mask |= POLLOUT | POLLWRNORM; 3437 } 3438 spin_unlock_bh(&sk->sk_write_queue.lock); 3439 return mask; 3440 } 3441 3442 3443 /* Dirty? Well, I still did not learn better way to account 3444 * for user mmaps. 3445 */ 3446 3447 static void packet_mm_open(struct vm_area_struct *vma) 3448 { 3449 struct file *file = vma->vm_file; 3450 struct socket *sock = file->private_data; 3451 struct sock *sk = sock->sk; 3452 3453 if (sk) 3454 atomic_inc(&pkt_sk(sk)->mapped); 3455 } 3456 3457 static void packet_mm_close(struct vm_area_struct *vma) 3458 { 3459 struct file *file = vma->vm_file; 3460 struct socket *sock = file->private_data; 3461 struct sock *sk = sock->sk; 3462 3463 if (sk) 3464 atomic_dec(&pkt_sk(sk)->mapped); 3465 } 3466 3467 static const struct vm_operations_struct packet_mmap_ops = { 3468 .open = packet_mm_open, 3469 .close = packet_mm_close, 3470 }; 3471 3472 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3473 unsigned int len) 3474 { 3475 int i; 3476 3477 for (i = 0; i < len; i++) { 3478 if (likely(pg_vec[i].buffer)) { 3479 if (is_vmalloc_addr(pg_vec[i].buffer)) 3480 vfree(pg_vec[i].buffer); 3481 else 3482 free_pages((unsigned long)pg_vec[i].buffer, 3483 order); 3484 pg_vec[i].buffer = NULL; 3485 } 3486 } 3487 kfree(pg_vec); 3488 } 3489 3490 static char *alloc_one_pg_vec_page(unsigned long order) 3491 { 3492 char *buffer = NULL; 3493 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3494 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3495 3496 buffer = (char *) __get_free_pages(gfp_flags, order); 3497 3498 if (buffer) 3499 return buffer; 3500 3501 /* 3502 * __get_free_pages failed, fall back to vmalloc 3503 */ 3504 buffer = vzalloc((1 << order) * PAGE_SIZE); 3505 3506 if (buffer) 3507 return buffer; 3508 3509 /* 3510 * vmalloc failed, lets dig into swap here 3511 */ 3512 gfp_flags &= ~__GFP_NORETRY; 3513 buffer = (char *)__get_free_pages(gfp_flags, order); 3514 if (buffer) 3515 return buffer; 3516 3517 /* 3518 * complete and utter failure 3519 */ 3520 return NULL; 3521 } 3522 3523 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3524 { 3525 unsigned int block_nr = req->tp_block_nr; 3526 struct pgv *pg_vec; 3527 int i; 3528 3529 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3530 if (unlikely(!pg_vec)) 3531 goto out; 3532 3533 for (i = 0; i < block_nr; i++) { 3534 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3535 if (unlikely(!pg_vec[i].buffer)) 3536 goto out_free_pgvec; 3537 } 3538 3539 out: 3540 return pg_vec; 3541 3542 out_free_pgvec: 3543 free_pg_vec(pg_vec, order, block_nr); 3544 pg_vec = NULL; 3545 goto out; 3546 } 3547 3548 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3549 int closing, int tx_ring) 3550 { 3551 struct pgv *pg_vec = NULL; 3552 struct packet_sock *po = pkt_sk(sk); 3553 int was_running, order = 0; 3554 struct packet_ring_buffer *rb; 3555 struct sk_buff_head *rb_queue; 3556 __be16 num; 3557 int err = -EINVAL; 3558 /* Added to avoid minimal code churn */ 3559 struct tpacket_req *req = &req_u->req; 3560 3561 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3562 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3563 WARN(1, "Tx-ring is not supported.\n"); 3564 goto out; 3565 } 3566 3567 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3568 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3569 3570 err = -EBUSY; 3571 if (!closing) { 3572 if (atomic_read(&po->mapped)) 3573 goto out; 3574 if (atomic_read(&rb->pending)) 3575 goto out; 3576 } 3577 3578 if (req->tp_block_nr) { 3579 /* Sanity tests and some calculations */ 3580 err = -EBUSY; 3581 if (unlikely(rb->pg_vec)) 3582 goto out; 3583 3584 switch (po->tp_version) { 3585 case TPACKET_V1: 3586 po->tp_hdrlen = TPACKET_HDRLEN; 3587 break; 3588 case TPACKET_V2: 3589 po->tp_hdrlen = TPACKET2_HDRLEN; 3590 break; 3591 case TPACKET_V3: 3592 po->tp_hdrlen = TPACKET3_HDRLEN; 3593 break; 3594 } 3595 3596 err = -EINVAL; 3597 if (unlikely((int)req->tp_block_size <= 0)) 3598 goto out; 3599 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3600 goto out; 3601 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3602 po->tp_reserve)) 3603 goto out; 3604 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3605 goto out; 3606 3607 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3608 if (unlikely(rb->frames_per_block <= 0)) 3609 goto out; 3610 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3611 req->tp_frame_nr)) 3612 goto out; 3613 3614 err = -ENOMEM; 3615 order = get_order(req->tp_block_size); 3616 pg_vec = alloc_pg_vec(req, order); 3617 if (unlikely(!pg_vec)) 3618 goto out; 3619 switch (po->tp_version) { 3620 case TPACKET_V3: 3621 /* Transmit path is not supported. We checked 3622 * it above but just being paranoid 3623 */ 3624 if (!tx_ring) 3625 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3626 break; 3627 default: 3628 break; 3629 } 3630 } 3631 /* Done */ 3632 else { 3633 err = -EINVAL; 3634 if (unlikely(req->tp_frame_nr)) 3635 goto out; 3636 } 3637 3638 lock_sock(sk); 3639 3640 /* Detach socket from network */ 3641 spin_lock(&po->bind_lock); 3642 was_running = po->running; 3643 num = po->num; 3644 if (was_running) { 3645 po->num = 0; 3646 __unregister_prot_hook(sk, false); 3647 } 3648 spin_unlock(&po->bind_lock); 3649 3650 synchronize_net(); 3651 3652 err = -EBUSY; 3653 mutex_lock(&po->pg_vec_lock); 3654 if (closing || atomic_read(&po->mapped) == 0) { 3655 err = 0; 3656 spin_lock_bh(&rb_queue->lock); 3657 swap(rb->pg_vec, pg_vec); 3658 rb->frame_max = (req->tp_frame_nr - 1); 3659 rb->head = 0; 3660 rb->frame_size = req->tp_frame_size; 3661 spin_unlock_bh(&rb_queue->lock); 3662 3663 swap(rb->pg_vec_order, order); 3664 swap(rb->pg_vec_len, req->tp_block_nr); 3665 3666 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3667 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3668 tpacket_rcv : packet_rcv; 3669 skb_queue_purge(rb_queue); 3670 if (atomic_read(&po->mapped)) 3671 pr_err("packet_mmap: vma is busy: %d\n", 3672 atomic_read(&po->mapped)); 3673 } 3674 mutex_unlock(&po->pg_vec_lock); 3675 3676 spin_lock(&po->bind_lock); 3677 if (was_running) { 3678 po->num = num; 3679 register_prot_hook(sk); 3680 } 3681 spin_unlock(&po->bind_lock); 3682 if (closing && (po->tp_version > TPACKET_V2)) { 3683 /* Because we don't support block-based V3 on tx-ring */ 3684 if (!tx_ring) 3685 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3686 } 3687 release_sock(sk); 3688 3689 if (pg_vec) 3690 free_pg_vec(pg_vec, order, req->tp_block_nr); 3691 out: 3692 return err; 3693 } 3694 3695 static int packet_mmap(struct file *file, struct socket *sock, 3696 struct vm_area_struct *vma) 3697 { 3698 struct sock *sk = sock->sk; 3699 struct packet_sock *po = pkt_sk(sk); 3700 unsigned long size, expected_size; 3701 struct packet_ring_buffer *rb; 3702 unsigned long start; 3703 int err = -EINVAL; 3704 int i; 3705 3706 if (vma->vm_pgoff) 3707 return -EINVAL; 3708 3709 mutex_lock(&po->pg_vec_lock); 3710 3711 expected_size = 0; 3712 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3713 if (rb->pg_vec) { 3714 expected_size += rb->pg_vec_len 3715 * rb->pg_vec_pages 3716 * PAGE_SIZE; 3717 } 3718 } 3719 3720 if (expected_size == 0) 3721 goto out; 3722 3723 size = vma->vm_end - vma->vm_start; 3724 if (size != expected_size) 3725 goto out; 3726 3727 start = vma->vm_start; 3728 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3729 if (rb->pg_vec == NULL) 3730 continue; 3731 3732 for (i = 0; i < rb->pg_vec_len; i++) { 3733 struct page *page; 3734 void *kaddr = rb->pg_vec[i].buffer; 3735 int pg_num; 3736 3737 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3738 page = pgv_to_page(kaddr); 3739 err = vm_insert_page(vma, start, page); 3740 if (unlikely(err)) 3741 goto out; 3742 start += PAGE_SIZE; 3743 kaddr += PAGE_SIZE; 3744 } 3745 } 3746 } 3747 3748 atomic_inc(&po->mapped); 3749 vma->vm_ops = &packet_mmap_ops; 3750 err = 0; 3751 3752 out: 3753 mutex_unlock(&po->pg_vec_lock); 3754 return err; 3755 } 3756 3757 static const struct proto_ops packet_ops_spkt = { 3758 .family = PF_PACKET, 3759 .owner = THIS_MODULE, 3760 .release = packet_release, 3761 .bind = packet_bind_spkt, 3762 .connect = sock_no_connect, 3763 .socketpair = sock_no_socketpair, 3764 .accept = sock_no_accept, 3765 .getname = packet_getname_spkt, 3766 .poll = datagram_poll, 3767 .ioctl = packet_ioctl, 3768 .listen = sock_no_listen, 3769 .shutdown = sock_no_shutdown, 3770 .setsockopt = sock_no_setsockopt, 3771 .getsockopt = sock_no_getsockopt, 3772 .sendmsg = packet_sendmsg_spkt, 3773 .recvmsg = packet_recvmsg, 3774 .mmap = sock_no_mmap, 3775 .sendpage = sock_no_sendpage, 3776 }; 3777 3778 static const struct proto_ops packet_ops = { 3779 .family = PF_PACKET, 3780 .owner = THIS_MODULE, 3781 .release = packet_release, 3782 .bind = packet_bind, 3783 .connect = sock_no_connect, 3784 .socketpair = sock_no_socketpair, 3785 .accept = sock_no_accept, 3786 .getname = packet_getname, 3787 .poll = packet_poll, 3788 .ioctl = packet_ioctl, 3789 .listen = sock_no_listen, 3790 .shutdown = sock_no_shutdown, 3791 .setsockopt = packet_setsockopt, 3792 .getsockopt = packet_getsockopt, 3793 .sendmsg = packet_sendmsg, 3794 .recvmsg = packet_recvmsg, 3795 .mmap = packet_mmap, 3796 .sendpage = sock_no_sendpage, 3797 }; 3798 3799 static const struct net_proto_family packet_family_ops = { 3800 .family = PF_PACKET, 3801 .create = packet_create, 3802 .owner = THIS_MODULE, 3803 }; 3804 3805 static struct notifier_block packet_netdev_notifier = { 3806 .notifier_call = packet_notifier, 3807 }; 3808 3809 #ifdef CONFIG_PROC_FS 3810 3811 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3812 __acquires(RCU) 3813 { 3814 struct net *net = seq_file_net(seq); 3815 3816 rcu_read_lock(); 3817 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3818 } 3819 3820 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3821 { 3822 struct net *net = seq_file_net(seq); 3823 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3824 } 3825 3826 static void packet_seq_stop(struct seq_file *seq, void *v) 3827 __releases(RCU) 3828 { 3829 rcu_read_unlock(); 3830 } 3831 3832 static int packet_seq_show(struct seq_file *seq, void *v) 3833 { 3834 if (v == SEQ_START_TOKEN) 3835 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3836 else { 3837 struct sock *s = sk_entry(v); 3838 const struct packet_sock *po = pkt_sk(s); 3839 3840 seq_printf(seq, 3841 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3842 s, 3843 atomic_read(&s->sk_refcnt), 3844 s->sk_type, 3845 ntohs(po->num), 3846 po->ifindex, 3847 po->running, 3848 atomic_read(&s->sk_rmem_alloc), 3849 sock_i_uid(s), 3850 sock_i_ino(s)); 3851 } 3852 3853 return 0; 3854 } 3855 3856 static const struct seq_operations packet_seq_ops = { 3857 .start = packet_seq_start, 3858 .next = packet_seq_next, 3859 .stop = packet_seq_stop, 3860 .show = packet_seq_show, 3861 }; 3862 3863 static int packet_seq_open(struct inode *inode, struct file *file) 3864 { 3865 return seq_open_net(inode, file, &packet_seq_ops, 3866 sizeof(struct seq_net_private)); 3867 } 3868 3869 static const struct file_operations packet_seq_fops = { 3870 .owner = THIS_MODULE, 3871 .open = packet_seq_open, 3872 .read = seq_read, 3873 .llseek = seq_lseek, 3874 .release = seq_release_net, 3875 }; 3876 3877 #endif 3878 3879 static int __net_init packet_net_init(struct net *net) 3880 { 3881 spin_lock_init(&net->packet.sklist_lock); 3882 INIT_HLIST_HEAD(&net->packet.sklist); 3883 3884 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops)) 3885 return -ENOMEM; 3886 3887 return 0; 3888 } 3889 3890 static void __net_exit packet_net_exit(struct net *net) 3891 { 3892 proc_net_remove(net, "packet"); 3893 } 3894 3895 static struct pernet_operations packet_net_ops = { 3896 .init = packet_net_init, 3897 .exit = packet_net_exit, 3898 }; 3899 3900 3901 static void __exit packet_exit(void) 3902 { 3903 unregister_netdevice_notifier(&packet_netdev_notifier); 3904 unregister_pernet_subsys(&packet_net_ops); 3905 sock_unregister(PF_PACKET); 3906 proto_unregister(&packet_proto); 3907 } 3908 3909 static int __init packet_init(void) 3910 { 3911 int rc = proto_register(&packet_proto, 0); 3912 3913 if (rc != 0) 3914 goto out; 3915 3916 sock_register(&packet_family_ops); 3917 register_pernet_subsys(&packet_net_ops); 3918 register_netdevice_notifier(&packet_netdev_notifier); 3919 out: 3920 return rc; 3921 } 3922 3923 module_init(packet_init); 3924 module_exit(packet_exit); 3925 MODULE_LICENSE("GPL"); 3926 MODULE_ALIAS_NETPROTO(PF_PACKET); 3927