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/system.h> 77 #include <asm/uaccess.h> 78 #include <asm/ioctls.h> 79 #include <asm/page.h> 80 #include <asm/cacheflush.h> 81 #include <asm/io.h> 82 #include <linux/proc_fs.h> 83 #include <linux/seq_file.h> 84 #include <linux/poll.h> 85 #include <linux/module.h> 86 #include <linux/init.h> 87 #include <linux/mutex.h> 88 #include <linux/if_vlan.h> 89 #include <linux/virtio_net.h> 90 #include <linux/errqueue.h> 91 #include <linux/net_tstamp.h> 92 93 #ifdef CONFIG_INET 94 #include <net/inet_common.h> 95 #endif 96 97 /* 98 Assumptions: 99 - if device has no dev->hard_header routine, it adds and removes ll header 100 inside itself. In this case ll header is invisible outside of device, 101 but higher levels still should reserve dev->hard_header_len. 102 Some devices are enough clever to reallocate skb, when header 103 will not fit to reserved space (tunnel), another ones are silly 104 (PPP). 105 - packet socket receives packets with pulled ll header, 106 so that SOCK_RAW should push it back. 107 108 On receive: 109 ----------- 110 111 Incoming, dev->hard_header!=NULL 112 mac_header -> ll header 113 data -> data 114 115 Outgoing, dev->hard_header!=NULL 116 mac_header -> ll header 117 data -> ll header 118 119 Incoming, dev->hard_header==NULL 120 mac_header -> UNKNOWN position. It is very likely, that it points to ll 121 header. PPP makes it, that is wrong, because introduce 122 assymetry between rx and tx paths. 123 data -> data 124 125 Outgoing, dev->hard_header==NULL 126 mac_header -> data. ll header is still not built! 127 data -> data 128 129 Resume 130 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 131 132 133 On transmit: 134 ------------ 135 136 dev->hard_header != NULL 137 mac_header -> ll header 138 data -> ll header 139 140 dev->hard_header == NULL (ll header is added by device, we cannot control it) 141 mac_header -> data 142 data -> data 143 144 We should set nh.raw on output to correct posistion, 145 packet classifier depends on it. 146 */ 147 148 /* Private packet socket structures. */ 149 150 struct packet_mclist { 151 struct packet_mclist *next; 152 int ifindex; 153 int count; 154 unsigned short type; 155 unsigned short alen; 156 unsigned char addr[MAX_ADDR_LEN]; 157 }; 158 /* identical to struct packet_mreq except it has 159 * a longer address field. 160 */ 161 struct packet_mreq_max { 162 int mr_ifindex; 163 unsigned short mr_type; 164 unsigned short mr_alen; 165 unsigned char mr_address[MAX_ADDR_LEN]; 166 }; 167 168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 169 int closing, int tx_ring); 170 171 172 #define V3_ALIGNMENT (8) 173 174 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 175 176 #define BLK_PLUS_PRIV(sz_of_priv) \ 177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 178 179 /* kbdq - kernel block descriptor queue */ 180 struct tpacket_kbdq_core { 181 struct pgv *pkbdq; 182 unsigned int feature_req_word; 183 unsigned int hdrlen; 184 unsigned char reset_pending_on_curr_blk; 185 unsigned char delete_blk_timer; 186 unsigned short kactive_blk_num; 187 unsigned short blk_sizeof_priv; 188 189 /* last_kactive_blk_num: 190 * trick to see if user-space has caught up 191 * in order to avoid refreshing timer when every single pkt arrives. 192 */ 193 unsigned short last_kactive_blk_num; 194 195 char *pkblk_start; 196 char *pkblk_end; 197 int kblk_size; 198 unsigned int knum_blocks; 199 uint64_t knxt_seq_num; 200 char *prev; 201 char *nxt_offset; 202 struct sk_buff *skb; 203 204 atomic_t blk_fill_in_prog; 205 206 /* Default is set to 8ms */ 207 #define DEFAULT_PRB_RETIRE_TOV (8) 208 209 unsigned short retire_blk_tov; 210 unsigned short version; 211 unsigned long tov_in_jiffies; 212 213 /* timer to retire an outstanding block */ 214 struct timer_list retire_blk_timer; 215 }; 216 217 #define PGV_FROM_VMALLOC 1 218 struct pgv { 219 char *buffer; 220 }; 221 222 struct packet_ring_buffer { 223 struct pgv *pg_vec; 224 unsigned int head; 225 unsigned int frames_per_block; 226 unsigned int frame_size; 227 unsigned int frame_max; 228 229 unsigned int pg_vec_order; 230 unsigned int pg_vec_pages; 231 unsigned int pg_vec_len; 232 233 struct tpacket_kbdq_core prb_bdqc; 234 atomic_t pending; 235 }; 236 237 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 238 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 239 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 240 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 241 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 242 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 243 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 244 245 struct packet_sock; 246 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 247 248 static void *packet_previous_frame(struct packet_sock *po, 249 struct packet_ring_buffer *rb, 250 int status); 251 static void packet_increment_head(struct packet_ring_buffer *buff); 252 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 253 struct tpacket_block_desc *); 254 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 255 struct packet_sock *); 256 static void prb_retire_current_block(struct tpacket_kbdq_core *, 257 struct packet_sock *, unsigned int status); 258 static int prb_queue_frozen(struct tpacket_kbdq_core *); 259 static void prb_open_block(struct tpacket_kbdq_core *, 260 struct tpacket_block_desc *); 261 static void prb_retire_rx_blk_timer_expired(unsigned long); 262 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 263 static void prb_init_blk_timer(struct packet_sock *, 264 struct tpacket_kbdq_core *, 265 void (*func) (unsigned long)); 266 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 267 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 268 struct tpacket3_hdr *); 269 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 270 struct tpacket3_hdr *); 271 static void packet_flush_mclist(struct sock *sk); 272 273 struct packet_fanout; 274 struct packet_sock { 275 /* struct sock has to be the first member of packet_sock */ 276 struct sock sk; 277 struct packet_fanout *fanout; 278 struct tpacket_stats stats; 279 union tpacket_stats_u stats_u; 280 struct packet_ring_buffer rx_ring; 281 struct packet_ring_buffer tx_ring; 282 int copy_thresh; 283 spinlock_t bind_lock; 284 struct mutex pg_vec_lock; 285 unsigned int running:1, /* prot_hook is attached*/ 286 auxdata:1, 287 origdev:1, 288 has_vnet_hdr:1; 289 int ifindex; /* bound device */ 290 __be16 num; 291 struct packet_mclist *mclist; 292 atomic_t mapped; 293 enum tpacket_versions tp_version; 294 unsigned int tp_hdrlen; 295 unsigned int tp_reserve; 296 unsigned int tp_loss:1; 297 unsigned int tp_tstamp; 298 struct packet_type prot_hook ____cacheline_aligned_in_smp; 299 }; 300 301 #define PACKET_FANOUT_MAX 256 302 303 struct packet_fanout { 304 #ifdef CONFIG_NET_NS 305 struct net *net; 306 #endif 307 unsigned int num_members; 308 u16 id; 309 u8 type; 310 u8 defrag; 311 atomic_t rr_cur; 312 struct list_head list; 313 struct sock *arr[PACKET_FANOUT_MAX]; 314 spinlock_t lock; 315 atomic_t sk_ref; 316 struct packet_type prot_hook ____cacheline_aligned_in_smp; 317 }; 318 319 struct packet_skb_cb { 320 unsigned int origlen; 321 union { 322 struct sockaddr_pkt pkt; 323 struct sockaddr_ll ll; 324 } sa; 325 }; 326 327 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 328 329 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 330 #define GET_PBLOCK_DESC(x, bid) \ 331 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 332 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 333 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 334 #define GET_NEXT_PRB_BLK_NUM(x) \ 335 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 336 ((x)->kactive_blk_num+1) : 0) 337 338 static struct packet_sock *pkt_sk(struct sock *sk) 339 { 340 return (struct packet_sock *)sk; 341 } 342 343 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 344 static void __fanout_link(struct sock *sk, struct packet_sock *po); 345 346 /* register_prot_hook must be invoked with the po->bind_lock held, 347 * or from a context in which asynchronous accesses to the packet 348 * socket is not possible (packet_create()). 349 */ 350 static void register_prot_hook(struct sock *sk) 351 { 352 struct packet_sock *po = pkt_sk(sk); 353 if (!po->running) { 354 if (po->fanout) 355 __fanout_link(sk, po); 356 else 357 dev_add_pack(&po->prot_hook); 358 sock_hold(sk); 359 po->running = 1; 360 } 361 } 362 363 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 364 * held. If the sync parameter is true, we will temporarily drop 365 * the po->bind_lock and do a synchronize_net to make sure no 366 * asynchronous packet processing paths still refer to the elements 367 * of po->prot_hook. If the sync parameter is false, it is the 368 * callers responsibility to take care of this. 369 */ 370 static void __unregister_prot_hook(struct sock *sk, bool sync) 371 { 372 struct packet_sock *po = pkt_sk(sk); 373 374 po->running = 0; 375 if (po->fanout) 376 __fanout_unlink(sk, po); 377 else 378 __dev_remove_pack(&po->prot_hook); 379 __sock_put(sk); 380 381 if (sync) { 382 spin_unlock(&po->bind_lock); 383 synchronize_net(); 384 spin_lock(&po->bind_lock); 385 } 386 } 387 388 static void unregister_prot_hook(struct sock *sk, bool sync) 389 { 390 struct packet_sock *po = pkt_sk(sk); 391 392 if (po->running) 393 __unregister_prot_hook(sk, sync); 394 } 395 396 static inline __pure struct page *pgv_to_page(void *addr) 397 { 398 if (is_vmalloc_addr(addr)) 399 return vmalloc_to_page(addr); 400 return virt_to_page(addr); 401 } 402 403 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 404 { 405 union { 406 struct tpacket_hdr *h1; 407 struct tpacket2_hdr *h2; 408 void *raw; 409 } h; 410 411 h.raw = frame; 412 switch (po->tp_version) { 413 case TPACKET_V1: 414 h.h1->tp_status = status; 415 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 416 break; 417 case TPACKET_V2: 418 h.h2->tp_status = status; 419 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 420 break; 421 case TPACKET_V3: 422 default: 423 WARN(1, "TPACKET version not supported.\n"); 424 BUG(); 425 } 426 427 smp_wmb(); 428 } 429 430 static int __packet_get_status(struct packet_sock *po, void *frame) 431 { 432 union { 433 struct tpacket_hdr *h1; 434 struct tpacket2_hdr *h2; 435 void *raw; 436 } h; 437 438 smp_rmb(); 439 440 h.raw = frame; 441 switch (po->tp_version) { 442 case TPACKET_V1: 443 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 444 return h.h1->tp_status; 445 case TPACKET_V2: 446 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 447 return h.h2->tp_status; 448 case TPACKET_V3: 449 default: 450 WARN(1, "TPACKET version not supported.\n"); 451 BUG(); 452 return 0; 453 } 454 } 455 456 static void *packet_lookup_frame(struct packet_sock *po, 457 struct packet_ring_buffer *rb, 458 unsigned int position, 459 int status) 460 { 461 unsigned int pg_vec_pos, frame_offset; 462 union { 463 struct tpacket_hdr *h1; 464 struct tpacket2_hdr *h2; 465 void *raw; 466 } h; 467 468 pg_vec_pos = position / rb->frames_per_block; 469 frame_offset = position % rb->frames_per_block; 470 471 h.raw = rb->pg_vec[pg_vec_pos].buffer + 472 (frame_offset * rb->frame_size); 473 474 if (status != __packet_get_status(po, h.raw)) 475 return NULL; 476 477 return h.raw; 478 } 479 480 static void *packet_current_frame(struct packet_sock *po, 481 struct packet_ring_buffer *rb, 482 int status) 483 { 484 return packet_lookup_frame(po, rb, rb->head, status); 485 } 486 487 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 488 { 489 del_timer_sync(&pkc->retire_blk_timer); 490 } 491 492 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 493 int tx_ring, 494 struct sk_buff_head *rb_queue) 495 { 496 struct tpacket_kbdq_core *pkc; 497 498 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 499 500 spin_lock(&rb_queue->lock); 501 pkc->delete_blk_timer = 1; 502 spin_unlock(&rb_queue->lock); 503 504 prb_del_retire_blk_timer(pkc); 505 } 506 507 static void prb_init_blk_timer(struct packet_sock *po, 508 struct tpacket_kbdq_core *pkc, 509 void (*func) (unsigned long)) 510 { 511 init_timer(&pkc->retire_blk_timer); 512 pkc->retire_blk_timer.data = (long)po; 513 pkc->retire_blk_timer.function = func; 514 pkc->retire_blk_timer.expires = jiffies; 515 } 516 517 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 518 { 519 struct tpacket_kbdq_core *pkc; 520 521 if (tx_ring) 522 BUG(); 523 524 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 525 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 526 } 527 528 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 529 int blk_size_in_bytes) 530 { 531 struct net_device *dev; 532 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 533 struct ethtool_cmd ecmd; 534 int err; 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 rtnl_unlock(); 544 if (!err) { 545 switch (ecmd.speed) { 546 case SPEED_10000: 547 msec = 1; 548 div = 10000/1000; 549 break; 550 case SPEED_1000: 551 msec = 1; 552 div = 1000/1000; 553 break; 554 /* 555 * If the link speed is so slow you don't really 556 * need to worry about perf anyways 557 */ 558 case SPEED_100: 559 case SPEED_10: 560 default: 561 return DEFAULT_PRB_RETIRE_TOV; 562 } 563 } 564 565 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 566 567 if (div) 568 mbits /= div; 569 570 tmo = mbits * msec; 571 572 if (div) 573 return tmo+1; 574 return tmo; 575 } 576 577 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 578 union tpacket_req_u *req_u) 579 { 580 p1->feature_req_word = req_u->req3.tp_feature_req_word; 581 } 582 583 static void init_prb_bdqc(struct packet_sock *po, 584 struct packet_ring_buffer *rb, 585 struct pgv *pg_vec, 586 union tpacket_req_u *req_u, int tx_ring) 587 { 588 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 589 struct tpacket_block_desc *pbd; 590 591 memset(p1, 0x0, sizeof(*p1)); 592 593 p1->knxt_seq_num = 1; 594 p1->pkbdq = pg_vec; 595 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 596 p1->pkblk_start = (char *)pg_vec[0].buffer; 597 p1->kblk_size = req_u->req3.tp_block_size; 598 p1->knum_blocks = req_u->req3.tp_block_nr; 599 p1->hdrlen = po->tp_hdrlen; 600 p1->version = po->tp_version; 601 p1->last_kactive_blk_num = 0; 602 po->stats_u.stats3.tp_freeze_q_cnt = 0; 603 if (req_u->req3.tp_retire_blk_tov) 604 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 605 else 606 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 607 req_u->req3.tp_block_size); 608 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 609 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 610 611 prb_init_ft_ops(p1, req_u); 612 prb_setup_retire_blk_timer(po, tx_ring); 613 prb_open_block(p1, pbd); 614 } 615 616 /* Do NOT update the last_blk_num first. 617 * Assumes sk_buff_head lock is held. 618 */ 619 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 620 { 621 mod_timer(&pkc->retire_blk_timer, 622 jiffies + pkc->tov_in_jiffies); 623 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 624 } 625 626 /* 627 * Timer logic: 628 * 1) We refresh the timer only when we open a block. 629 * By doing this we don't waste cycles refreshing the timer 630 * on packet-by-packet basis. 631 * 632 * With a 1MB block-size, on a 1Gbps line, it will take 633 * i) ~8 ms to fill a block + ii) memcpy etc. 634 * In this cut we are not accounting for the memcpy time. 635 * 636 * So, if the user sets the 'tmo' to 10ms then the timer 637 * will never fire while the block is still getting filled 638 * (which is what we want). However, the user could choose 639 * to close a block early and that's fine. 640 * 641 * But when the timer does fire, we check whether or not to refresh it. 642 * Since the tmo granularity is in msecs, it is not too expensive 643 * to refresh the timer, lets say every '8' msecs. 644 * Either the user can set the 'tmo' or we can derive it based on 645 * a) line-speed and b) block-size. 646 * prb_calc_retire_blk_tmo() calculates the tmo. 647 * 648 */ 649 static void prb_retire_rx_blk_timer_expired(unsigned long data) 650 { 651 struct packet_sock *po = (struct packet_sock *)data; 652 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 653 unsigned int frozen; 654 struct tpacket_block_desc *pbd; 655 656 spin_lock(&po->sk.sk_receive_queue.lock); 657 658 frozen = prb_queue_frozen(pkc); 659 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 660 661 if (unlikely(pkc->delete_blk_timer)) 662 goto out; 663 664 /* We only need to plug the race when the block is partially filled. 665 * tpacket_rcv: 666 * lock(); increment BLOCK_NUM_PKTS; unlock() 667 * copy_bits() is in progress ... 668 * timer fires on other cpu: 669 * we can't retire the current block because copy_bits 670 * is in progress. 671 * 672 */ 673 if (BLOCK_NUM_PKTS(pbd)) { 674 while (atomic_read(&pkc->blk_fill_in_prog)) { 675 /* Waiting for skb_copy_bits to finish... */ 676 cpu_relax(); 677 } 678 } 679 680 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 681 if (!frozen) { 682 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 683 if (!prb_dispatch_next_block(pkc, po)) 684 goto refresh_timer; 685 else 686 goto out; 687 } else { 688 /* Case 1. Queue was frozen because user-space was 689 * lagging behind. 690 */ 691 if (prb_curr_blk_in_use(pkc, pbd)) { 692 /* 693 * Ok, user-space is still behind. 694 * So just refresh the timer. 695 */ 696 goto refresh_timer; 697 } else { 698 /* Case 2. queue was frozen,user-space caught up, 699 * now the link went idle && the timer fired. 700 * We don't have a block to close.So we open this 701 * block and restart the timer. 702 * opening a block thaws the queue,restarts timer 703 * Thawing/timer-refresh is a side effect. 704 */ 705 prb_open_block(pkc, pbd); 706 goto out; 707 } 708 } 709 } 710 711 refresh_timer: 712 _prb_refresh_rx_retire_blk_timer(pkc); 713 714 out: 715 spin_unlock(&po->sk.sk_receive_queue.lock); 716 } 717 718 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 719 struct tpacket_block_desc *pbd1, __u32 status) 720 { 721 /* Flush everything minus the block header */ 722 723 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 724 u8 *start, *end; 725 726 start = (u8 *)pbd1; 727 728 /* Skip the block header(we know header WILL fit in 4K) */ 729 start += PAGE_SIZE; 730 731 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 732 for (; start < end; start += PAGE_SIZE) 733 flush_dcache_page(pgv_to_page(start)); 734 735 smp_wmb(); 736 #endif 737 738 /* Now update the block status. */ 739 740 BLOCK_STATUS(pbd1) = status; 741 742 /* Flush the block header */ 743 744 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 745 start = (u8 *)pbd1; 746 flush_dcache_page(pgv_to_page(start)); 747 748 smp_wmb(); 749 #endif 750 } 751 752 /* 753 * Side effect: 754 * 755 * 1) flush the block 756 * 2) Increment active_blk_num 757 * 758 * Note:We DONT refresh the timer on purpose. 759 * Because almost always the next block will be opened. 760 */ 761 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 762 struct tpacket_block_desc *pbd1, 763 struct packet_sock *po, unsigned int stat) 764 { 765 __u32 status = TP_STATUS_USER | stat; 766 767 struct tpacket3_hdr *last_pkt; 768 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 769 770 if (po->stats.tp_drops) 771 status |= TP_STATUS_LOSING; 772 773 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 774 last_pkt->tp_next_offset = 0; 775 776 /* Get the ts of the last pkt */ 777 if (BLOCK_NUM_PKTS(pbd1)) { 778 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 779 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 780 } else { 781 /* Ok, we tmo'd - so get the current time */ 782 struct timespec ts; 783 getnstimeofday(&ts); 784 h1->ts_last_pkt.ts_sec = ts.tv_sec; 785 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 786 } 787 788 smp_wmb(); 789 790 /* Flush the block */ 791 prb_flush_block(pkc1, pbd1, status); 792 793 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 794 } 795 796 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 797 { 798 pkc->reset_pending_on_curr_blk = 0; 799 } 800 801 /* 802 * Side effect of opening a block: 803 * 804 * 1) prb_queue is thawed. 805 * 2) retire_blk_timer is refreshed. 806 * 807 */ 808 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 809 struct tpacket_block_desc *pbd1) 810 { 811 struct timespec ts; 812 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 813 814 smp_rmb(); 815 816 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { 817 818 /* We could have just memset this but we will lose the 819 * flexibility of making the priv area sticky 820 */ 821 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 822 BLOCK_NUM_PKTS(pbd1) = 0; 823 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 824 getnstimeofday(&ts); 825 h1->ts_first_pkt.ts_sec = ts.tv_sec; 826 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 827 pkc1->pkblk_start = (char *)pbd1; 828 pkc1->nxt_offset = (char *)(pkc1->pkblk_start + 829 BLK_PLUS_PRIV(pkc1->blk_sizeof_priv)); 830 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 831 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 832 pbd1->version = pkc1->version; 833 pkc1->prev = pkc1->nxt_offset; 834 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 835 prb_thaw_queue(pkc1); 836 _prb_refresh_rx_retire_blk_timer(pkc1); 837 838 smp_wmb(); 839 840 return; 841 } 842 843 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", 844 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); 845 dump_stack(); 846 BUG(); 847 } 848 849 /* 850 * Queue freeze logic: 851 * 1) Assume tp_block_nr = 8 blocks. 852 * 2) At time 't0', user opens Rx ring. 853 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 854 * 4) user-space is either sleeping or processing block '0'. 855 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 856 * it will close block-7,loop around and try to fill block '0'. 857 * call-flow: 858 * __packet_lookup_frame_in_block 859 * prb_retire_current_block() 860 * prb_dispatch_next_block() 861 * |->(BLOCK_STATUS == USER) evaluates to true 862 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 863 * 6) Now there are two cases: 864 * 6.1) Link goes idle right after the queue is frozen. 865 * But remember, the last open_block() refreshed the timer. 866 * When this timer expires,it will refresh itself so that we can 867 * re-open block-0 in near future. 868 * 6.2) Link is busy and keeps on receiving packets. This is a simple 869 * case and __packet_lookup_frame_in_block will check if block-0 870 * is free and can now be re-used. 871 */ 872 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 873 struct packet_sock *po) 874 { 875 pkc->reset_pending_on_curr_blk = 1; 876 po->stats_u.stats3.tp_freeze_q_cnt++; 877 } 878 879 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 880 881 /* 882 * If the next block is free then we will dispatch it 883 * and return a good offset. 884 * Else, we will freeze the queue. 885 * So, caller must check the return value. 886 */ 887 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 888 struct packet_sock *po) 889 { 890 struct tpacket_block_desc *pbd; 891 892 smp_rmb(); 893 894 /* 1. Get current block num */ 895 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 896 897 /* 2. If this block is currently in_use then freeze the queue */ 898 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 899 prb_freeze_queue(pkc, po); 900 return NULL; 901 } 902 903 /* 904 * 3. 905 * open this block and return the offset where the first packet 906 * needs to get stored. 907 */ 908 prb_open_block(pkc, pbd); 909 return (void *)pkc->nxt_offset; 910 } 911 912 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 913 struct packet_sock *po, unsigned int status) 914 { 915 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 916 917 /* retire/close the current block */ 918 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 919 /* 920 * Plug the case where copy_bits() is in progress on 921 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 922 * have space to copy the pkt in the current block and 923 * called prb_retire_current_block() 924 * 925 * We don't need to worry about the TMO case because 926 * the timer-handler already handled this case. 927 */ 928 if (!(status & TP_STATUS_BLK_TMO)) { 929 while (atomic_read(&pkc->blk_fill_in_prog)) { 930 /* Waiting for skb_copy_bits to finish... */ 931 cpu_relax(); 932 } 933 } 934 prb_close_block(pkc, pbd, po, status); 935 return; 936 } 937 938 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); 939 dump_stack(); 940 BUG(); 941 } 942 943 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 944 struct tpacket_block_desc *pbd) 945 { 946 return TP_STATUS_USER & BLOCK_STATUS(pbd); 947 } 948 949 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 950 { 951 return pkc->reset_pending_on_curr_blk; 952 } 953 954 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 955 { 956 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 957 atomic_dec(&pkc->blk_fill_in_prog); 958 } 959 960 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 961 struct tpacket3_hdr *ppd) 962 { 963 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 964 } 965 966 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 967 struct tpacket3_hdr *ppd) 968 { 969 ppd->hv1.tp_rxhash = 0; 970 } 971 972 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 973 struct tpacket3_hdr *ppd) 974 { 975 if (vlan_tx_tag_present(pkc->skb)) { 976 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 977 ppd->tp_status = TP_STATUS_VLAN_VALID; 978 } else { 979 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0; 980 } 981 } 982 983 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 984 struct tpacket3_hdr *ppd) 985 { 986 prb_fill_vlan_info(pkc, ppd); 987 988 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 989 prb_fill_rxhash(pkc, ppd); 990 else 991 prb_clear_rxhash(pkc, ppd); 992 } 993 994 static void prb_fill_curr_block(char *curr, 995 struct tpacket_kbdq_core *pkc, 996 struct tpacket_block_desc *pbd, 997 unsigned int len) 998 { 999 struct tpacket3_hdr *ppd; 1000 1001 ppd = (struct tpacket3_hdr *)curr; 1002 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1003 pkc->prev = curr; 1004 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1005 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1006 BLOCK_NUM_PKTS(pbd) += 1; 1007 atomic_inc(&pkc->blk_fill_in_prog); 1008 prb_run_all_ft_ops(pkc, ppd); 1009 } 1010 1011 /* Assumes caller has the sk->rx_queue.lock */ 1012 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1013 struct sk_buff *skb, 1014 int status, 1015 unsigned int len 1016 ) 1017 { 1018 struct tpacket_kbdq_core *pkc; 1019 struct tpacket_block_desc *pbd; 1020 char *curr, *end; 1021 1022 pkc = GET_PBDQC_FROM_RB(((struct packet_ring_buffer *)&po->rx_ring)); 1023 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1024 1025 /* Queue is frozen when user space is lagging behind */ 1026 if (prb_queue_frozen(pkc)) { 1027 /* 1028 * Check if that last block which caused the queue to freeze, 1029 * is still in_use by user-space. 1030 */ 1031 if (prb_curr_blk_in_use(pkc, pbd)) { 1032 /* Can't record this packet */ 1033 return NULL; 1034 } else { 1035 /* 1036 * Ok, the block was released by user-space. 1037 * Now let's open that block. 1038 * opening a block also thaws the queue. 1039 * Thawing is a side effect. 1040 */ 1041 prb_open_block(pkc, pbd); 1042 } 1043 } 1044 1045 smp_mb(); 1046 curr = pkc->nxt_offset; 1047 pkc->skb = skb; 1048 end = (char *) ((char *)pbd + pkc->kblk_size); 1049 1050 /* first try the current block */ 1051 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1052 prb_fill_curr_block(curr, pkc, pbd, len); 1053 return (void *)curr; 1054 } 1055 1056 /* Ok, close the current block */ 1057 prb_retire_current_block(pkc, po, 0); 1058 1059 /* Now, try to dispatch the next block */ 1060 curr = (char *)prb_dispatch_next_block(pkc, po); 1061 if (curr) { 1062 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1063 prb_fill_curr_block(curr, pkc, pbd, len); 1064 return (void *)curr; 1065 } 1066 1067 /* 1068 * No free blocks are available.user_space hasn't caught up yet. 1069 * Queue was just frozen and now this packet will get dropped. 1070 */ 1071 return NULL; 1072 } 1073 1074 static void *packet_current_rx_frame(struct packet_sock *po, 1075 struct sk_buff *skb, 1076 int status, unsigned int len) 1077 { 1078 char *curr = NULL; 1079 switch (po->tp_version) { 1080 case TPACKET_V1: 1081 case TPACKET_V2: 1082 curr = packet_lookup_frame(po, &po->rx_ring, 1083 po->rx_ring.head, status); 1084 return curr; 1085 case TPACKET_V3: 1086 return __packet_lookup_frame_in_block(po, skb, status, len); 1087 default: 1088 WARN(1, "TPACKET version not supported\n"); 1089 BUG(); 1090 return 0; 1091 } 1092 } 1093 1094 static void *prb_lookup_block(struct packet_sock *po, 1095 struct packet_ring_buffer *rb, 1096 unsigned int previous, 1097 int status) 1098 { 1099 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1100 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous); 1101 1102 if (status != BLOCK_STATUS(pbd)) 1103 return NULL; 1104 return pbd; 1105 } 1106 1107 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1108 { 1109 unsigned int prev; 1110 if (rb->prb_bdqc.kactive_blk_num) 1111 prev = rb->prb_bdqc.kactive_blk_num-1; 1112 else 1113 prev = rb->prb_bdqc.knum_blocks-1; 1114 return prev; 1115 } 1116 1117 /* Assumes caller has held the rx_queue.lock */ 1118 static void *__prb_previous_block(struct packet_sock *po, 1119 struct packet_ring_buffer *rb, 1120 int status) 1121 { 1122 unsigned int previous = prb_previous_blk_num(rb); 1123 return prb_lookup_block(po, rb, previous, status); 1124 } 1125 1126 static void *packet_previous_rx_frame(struct packet_sock *po, 1127 struct packet_ring_buffer *rb, 1128 int status) 1129 { 1130 if (po->tp_version <= TPACKET_V2) 1131 return packet_previous_frame(po, rb, status); 1132 1133 return __prb_previous_block(po, rb, status); 1134 } 1135 1136 static void packet_increment_rx_head(struct packet_sock *po, 1137 struct packet_ring_buffer *rb) 1138 { 1139 switch (po->tp_version) { 1140 case TPACKET_V1: 1141 case TPACKET_V2: 1142 return packet_increment_head(rb); 1143 case TPACKET_V3: 1144 default: 1145 WARN(1, "TPACKET version not supported.\n"); 1146 BUG(); 1147 return; 1148 } 1149 } 1150 1151 static void *packet_previous_frame(struct packet_sock *po, 1152 struct packet_ring_buffer *rb, 1153 int status) 1154 { 1155 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1156 return packet_lookup_frame(po, rb, previous, status); 1157 } 1158 1159 static void packet_increment_head(struct packet_ring_buffer *buff) 1160 { 1161 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1162 } 1163 1164 static void packet_sock_destruct(struct sock *sk) 1165 { 1166 skb_queue_purge(&sk->sk_error_queue); 1167 1168 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1169 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1170 1171 if (!sock_flag(sk, SOCK_DEAD)) { 1172 pr_err("Attempt to release alive packet socket: %p\n", sk); 1173 return; 1174 } 1175 1176 sk_refcnt_debug_dec(sk); 1177 } 1178 1179 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1180 { 1181 int x = atomic_read(&f->rr_cur) + 1; 1182 1183 if (x >= num) 1184 x = 0; 1185 1186 return x; 1187 } 1188 1189 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1190 { 1191 u32 idx, hash = skb->rxhash; 1192 1193 idx = ((u64)hash * num) >> 32; 1194 1195 return f->arr[idx]; 1196 } 1197 1198 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1199 { 1200 int cur, old; 1201 1202 cur = atomic_read(&f->rr_cur); 1203 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1204 fanout_rr_next(f, num))) != cur) 1205 cur = old; 1206 return f->arr[cur]; 1207 } 1208 1209 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1210 { 1211 unsigned int cpu = smp_processor_id(); 1212 1213 return f->arr[cpu % num]; 1214 } 1215 1216 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1217 struct packet_type *pt, struct net_device *orig_dev) 1218 { 1219 struct packet_fanout *f = pt->af_packet_priv; 1220 unsigned int num = f->num_members; 1221 struct packet_sock *po; 1222 struct sock *sk; 1223 1224 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1225 !num) { 1226 kfree_skb(skb); 1227 return 0; 1228 } 1229 1230 switch (f->type) { 1231 case PACKET_FANOUT_HASH: 1232 default: 1233 if (f->defrag) { 1234 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1235 if (!skb) 1236 return 0; 1237 } 1238 skb_get_rxhash(skb); 1239 sk = fanout_demux_hash(f, skb, num); 1240 break; 1241 case PACKET_FANOUT_LB: 1242 sk = fanout_demux_lb(f, skb, num); 1243 break; 1244 case PACKET_FANOUT_CPU: 1245 sk = fanout_demux_cpu(f, skb, num); 1246 break; 1247 } 1248 1249 po = pkt_sk(sk); 1250 1251 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1252 } 1253 1254 static DEFINE_MUTEX(fanout_mutex); 1255 static LIST_HEAD(fanout_list); 1256 1257 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1258 { 1259 struct packet_fanout *f = po->fanout; 1260 1261 spin_lock(&f->lock); 1262 f->arr[f->num_members] = sk; 1263 smp_wmb(); 1264 f->num_members++; 1265 spin_unlock(&f->lock); 1266 } 1267 1268 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1269 { 1270 struct packet_fanout *f = po->fanout; 1271 int i; 1272 1273 spin_lock(&f->lock); 1274 for (i = 0; i < f->num_members; i++) { 1275 if (f->arr[i] == sk) 1276 break; 1277 } 1278 BUG_ON(i >= f->num_members); 1279 f->arr[i] = f->arr[f->num_members - 1]; 1280 f->num_members--; 1281 spin_unlock(&f->lock); 1282 } 1283 1284 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1285 { 1286 struct packet_sock *po = pkt_sk(sk); 1287 struct packet_fanout *f, *match; 1288 u8 type = type_flags & 0xff; 1289 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; 1290 int err; 1291 1292 switch (type) { 1293 case PACKET_FANOUT_HASH: 1294 case PACKET_FANOUT_LB: 1295 case PACKET_FANOUT_CPU: 1296 break; 1297 default: 1298 return -EINVAL; 1299 } 1300 1301 if (!po->running) 1302 return -EINVAL; 1303 1304 if (po->fanout) 1305 return -EALREADY; 1306 1307 mutex_lock(&fanout_mutex); 1308 match = NULL; 1309 list_for_each_entry(f, &fanout_list, list) { 1310 if (f->id == id && 1311 read_pnet(&f->net) == sock_net(sk)) { 1312 match = f; 1313 break; 1314 } 1315 } 1316 err = -EINVAL; 1317 if (match && match->defrag != defrag) 1318 goto out; 1319 if (!match) { 1320 err = -ENOMEM; 1321 match = kzalloc(sizeof(*match), GFP_KERNEL); 1322 if (!match) 1323 goto out; 1324 write_pnet(&match->net, sock_net(sk)); 1325 match->id = id; 1326 match->type = type; 1327 match->defrag = defrag; 1328 atomic_set(&match->rr_cur, 0); 1329 INIT_LIST_HEAD(&match->list); 1330 spin_lock_init(&match->lock); 1331 atomic_set(&match->sk_ref, 0); 1332 match->prot_hook.type = po->prot_hook.type; 1333 match->prot_hook.dev = po->prot_hook.dev; 1334 match->prot_hook.func = packet_rcv_fanout; 1335 match->prot_hook.af_packet_priv = match; 1336 dev_add_pack(&match->prot_hook); 1337 list_add(&match->list, &fanout_list); 1338 } 1339 err = -EINVAL; 1340 if (match->type == type && 1341 match->prot_hook.type == po->prot_hook.type && 1342 match->prot_hook.dev == po->prot_hook.dev) { 1343 err = -ENOSPC; 1344 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1345 __dev_remove_pack(&po->prot_hook); 1346 po->fanout = match; 1347 atomic_inc(&match->sk_ref); 1348 __fanout_link(sk, po); 1349 err = 0; 1350 } 1351 } 1352 out: 1353 mutex_unlock(&fanout_mutex); 1354 return err; 1355 } 1356 1357 static void fanout_release(struct sock *sk) 1358 { 1359 struct packet_sock *po = pkt_sk(sk); 1360 struct packet_fanout *f; 1361 1362 f = po->fanout; 1363 if (!f) 1364 return; 1365 1366 po->fanout = NULL; 1367 1368 mutex_lock(&fanout_mutex); 1369 if (atomic_dec_and_test(&f->sk_ref)) { 1370 list_del(&f->list); 1371 dev_remove_pack(&f->prot_hook); 1372 kfree(f); 1373 } 1374 mutex_unlock(&fanout_mutex); 1375 } 1376 1377 static const struct proto_ops packet_ops; 1378 1379 static const struct proto_ops packet_ops_spkt; 1380 1381 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1382 struct packet_type *pt, struct net_device *orig_dev) 1383 { 1384 struct sock *sk; 1385 struct sockaddr_pkt *spkt; 1386 1387 /* 1388 * When we registered the protocol we saved the socket in the data 1389 * field for just this event. 1390 */ 1391 1392 sk = pt->af_packet_priv; 1393 1394 /* 1395 * Yank back the headers [hope the device set this 1396 * right or kerboom...] 1397 * 1398 * Incoming packets have ll header pulled, 1399 * push it back. 1400 * 1401 * For outgoing ones skb->data == skb_mac_header(skb) 1402 * so that this procedure is noop. 1403 */ 1404 1405 if (skb->pkt_type == PACKET_LOOPBACK) 1406 goto out; 1407 1408 if (!net_eq(dev_net(dev), sock_net(sk))) 1409 goto out; 1410 1411 skb = skb_share_check(skb, GFP_ATOMIC); 1412 if (skb == NULL) 1413 goto oom; 1414 1415 /* drop any routing info */ 1416 skb_dst_drop(skb); 1417 1418 /* drop conntrack reference */ 1419 nf_reset(skb); 1420 1421 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1422 1423 skb_push(skb, skb->data - skb_mac_header(skb)); 1424 1425 /* 1426 * The SOCK_PACKET socket receives _all_ frames. 1427 */ 1428 1429 spkt->spkt_family = dev->type; 1430 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1431 spkt->spkt_protocol = skb->protocol; 1432 1433 /* 1434 * Charge the memory to the socket. This is done specifically 1435 * to prevent sockets using all the memory up. 1436 */ 1437 1438 if (sock_queue_rcv_skb(sk, skb) == 0) 1439 return 0; 1440 1441 out: 1442 kfree_skb(skb); 1443 oom: 1444 return 0; 1445 } 1446 1447 1448 /* 1449 * Output a raw packet to a device layer. This bypasses all the other 1450 * protocol layers and you must therefore supply it with a complete frame 1451 */ 1452 1453 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1454 struct msghdr *msg, size_t len) 1455 { 1456 struct sock *sk = sock->sk; 1457 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1458 struct sk_buff *skb = NULL; 1459 struct net_device *dev; 1460 __be16 proto = 0; 1461 int err; 1462 int extra_len = 0; 1463 1464 /* 1465 * Get and verify the address. 1466 */ 1467 1468 if (saddr) { 1469 if (msg->msg_namelen < sizeof(struct sockaddr)) 1470 return -EINVAL; 1471 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1472 proto = saddr->spkt_protocol; 1473 } else 1474 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1475 1476 /* 1477 * Find the device first to size check it 1478 */ 1479 1480 saddr->spkt_device[13] = 0; 1481 retry: 1482 rcu_read_lock(); 1483 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1484 err = -ENODEV; 1485 if (dev == NULL) 1486 goto out_unlock; 1487 1488 err = -ENETDOWN; 1489 if (!(dev->flags & IFF_UP)) 1490 goto out_unlock; 1491 1492 /* 1493 * You may not queue a frame bigger than the mtu. This is the lowest level 1494 * raw protocol and you must do your own fragmentation at this level. 1495 */ 1496 1497 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1498 if (!netif_supports_nofcs(dev)) { 1499 err = -EPROTONOSUPPORT; 1500 goto out_unlock; 1501 } 1502 extra_len = 4; /* We're doing our own CRC */ 1503 } 1504 1505 err = -EMSGSIZE; 1506 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1507 goto out_unlock; 1508 1509 if (!skb) { 1510 size_t reserved = LL_RESERVED_SPACE(dev); 1511 int tlen = dev->needed_tailroom; 1512 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1513 1514 rcu_read_unlock(); 1515 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1516 if (skb == NULL) 1517 return -ENOBUFS; 1518 /* FIXME: Save some space for broken drivers that write a hard 1519 * header at transmission time by themselves. PPP is the notable 1520 * one here. This should really be fixed at the driver level. 1521 */ 1522 skb_reserve(skb, reserved); 1523 skb_reset_network_header(skb); 1524 1525 /* Try to align data part correctly */ 1526 if (hhlen) { 1527 skb->data -= hhlen; 1528 skb->tail -= hhlen; 1529 if (len < hhlen) 1530 skb_reset_network_header(skb); 1531 } 1532 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1533 if (err) 1534 goto out_free; 1535 goto retry; 1536 } 1537 1538 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1539 /* Earlier code assumed this would be a VLAN pkt, 1540 * double-check this now that we have the actual 1541 * packet in hand. 1542 */ 1543 struct ethhdr *ehdr; 1544 skb_reset_mac_header(skb); 1545 ehdr = eth_hdr(skb); 1546 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1547 err = -EMSGSIZE; 1548 goto out_unlock; 1549 } 1550 } 1551 1552 skb->protocol = proto; 1553 skb->dev = dev; 1554 skb->priority = sk->sk_priority; 1555 skb->mark = sk->sk_mark; 1556 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1557 if (err < 0) 1558 goto out_unlock; 1559 1560 if (unlikely(extra_len == 4)) 1561 skb->no_fcs = 1; 1562 1563 dev_queue_xmit(skb); 1564 rcu_read_unlock(); 1565 return len; 1566 1567 out_unlock: 1568 rcu_read_unlock(); 1569 out_free: 1570 kfree_skb(skb); 1571 return err; 1572 } 1573 1574 static unsigned int run_filter(const struct sk_buff *skb, 1575 const struct sock *sk, 1576 unsigned int res) 1577 { 1578 struct sk_filter *filter; 1579 1580 rcu_read_lock(); 1581 filter = rcu_dereference(sk->sk_filter); 1582 if (filter != NULL) 1583 res = SK_RUN_FILTER(filter, skb); 1584 rcu_read_unlock(); 1585 1586 return res; 1587 } 1588 1589 /* 1590 * This function makes lazy skb cloning in hope that most of packets 1591 * are discarded by BPF. 1592 * 1593 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1594 * and skb->cb are mangled. It works because (and until) packets 1595 * falling here are owned by current CPU. Output packets are cloned 1596 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1597 * sequencially, so that if we return skb to original state on exit, 1598 * we will not harm anyone. 1599 */ 1600 1601 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1602 struct packet_type *pt, struct net_device *orig_dev) 1603 { 1604 struct sock *sk; 1605 struct sockaddr_ll *sll; 1606 struct packet_sock *po; 1607 u8 *skb_head = skb->data; 1608 int skb_len = skb->len; 1609 unsigned int snaplen, res; 1610 1611 if (skb->pkt_type == PACKET_LOOPBACK) 1612 goto drop; 1613 1614 sk = pt->af_packet_priv; 1615 po = pkt_sk(sk); 1616 1617 if (!net_eq(dev_net(dev), sock_net(sk))) 1618 goto drop; 1619 1620 skb->dev = dev; 1621 1622 if (dev->header_ops) { 1623 /* The device has an explicit notion of ll header, 1624 * exported to higher levels. 1625 * 1626 * Otherwise, the device hides details of its frame 1627 * structure, so that corresponding packet head is 1628 * never delivered to user. 1629 */ 1630 if (sk->sk_type != SOCK_DGRAM) 1631 skb_push(skb, skb->data - skb_mac_header(skb)); 1632 else if (skb->pkt_type == PACKET_OUTGOING) { 1633 /* Special case: outgoing packets have ll header at head */ 1634 skb_pull(skb, skb_network_offset(skb)); 1635 } 1636 } 1637 1638 snaplen = skb->len; 1639 1640 res = run_filter(skb, sk, snaplen); 1641 if (!res) 1642 goto drop_n_restore; 1643 if (snaplen > res) 1644 snaplen = res; 1645 1646 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1647 goto drop_n_acct; 1648 1649 if (skb_shared(skb)) { 1650 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1651 if (nskb == NULL) 1652 goto drop_n_acct; 1653 1654 if (skb_head != skb->data) { 1655 skb->data = skb_head; 1656 skb->len = skb_len; 1657 } 1658 kfree_skb(skb); 1659 skb = nskb; 1660 } 1661 1662 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1663 sizeof(skb->cb)); 1664 1665 sll = &PACKET_SKB_CB(skb)->sa.ll; 1666 sll->sll_family = AF_PACKET; 1667 sll->sll_hatype = dev->type; 1668 sll->sll_protocol = skb->protocol; 1669 sll->sll_pkttype = skb->pkt_type; 1670 if (unlikely(po->origdev)) 1671 sll->sll_ifindex = orig_dev->ifindex; 1672 else 1673 sll->sll_ifindex = dev->ifindex; 1674 1675 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1676 1677 PACKET_SKB_CB(skb)->origlen = skb->len; 1678 1679 if (pskb_trim(skb, snaplen)) 1680 goto drop_n_acct; 1681 1682 skb_set_owner_r(skb, sk); 1683 skb->dev = NULL; 1684 skb_dst_drop(skb); 1685 1686 /* drop conntrack reference */ 1687 nf_reset(skb); 1688 1689 spin_lock(&sk->sk_receive_queue.lock); 1690 po->stats.tp_packets++; 1691 skb->dropcount = atomic_read(&sk->sk_drops); 1692 __skb_queue_tail(&sk->sk_receive_queue, skb); 1693 spin_unlock(&sk->sk_receive_queue.lock); 1694 sk->sk_data_ready(sk, skb->len); 1695 return 0; 1696 1697 drop_n_acct: 1698 spin_lock(&sk->sk_receive_queue.lock); 1699 po->stats.tp_drops++; 1700 atomic_inc(&sk->sk_drops); 1701 spin_unlock(&sk->sk_receive_queue.lock); 1702 1703 drop_n_restore: 1704 if (skb_head != skb->data && skb_shared(skb)) { 1705 skb->data = skb_head; 1706 skb->len = skb_len; 1707 } 1708 drop: 1709 consume_skb(skb); 1710 return 0; 1711 } 1712 1713 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1714 struct packet_type *pt, struct net_device *orig_dev) 1715 { 1716 struct sock *sk; 1717 struct packet_sock *po; 1718 struct sockaddr_ll *sll; 1719 union { 1720 struct tpacket_hdr *h1; 1721 struct tpacket2_hdr *h2; 1722 struct tpacket3_hdr *h3; 1723 void *raw; 1724 } h; 1725 u8 *skb_head = skb->data; 1726 int skb_len = skb->len; 1727 unsigned int snaplen, res; 1728 unsigned long status = TP_STATUS_USER; 1729 unsigned short macoff, netoff, hdrlen; 1730 struct sk_buff *copy_skb = NULL; 1731 struct timeval tv; 1732 struct timespec ts; 1733 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 1734 1735 if (skb->pkt_type == PACKET_LOOPBACK) 1736 goto drop; 1737 1738 sk = pt->af_packet_priv; 1739 po = pkt_sk(sk); 1740 1741 if (!net_eq(dev_net(dev), sock_net(sk))) 1742 goto drop; 1743 1744 if (dev->header_ops) { 1745 if (sk->sk_type != SOCK_DGRAM) 1746 skb_push(skb, skb->data - skb_mac_header(skb)); 1747 else if (skb->pkt_type == PACKET_OUTGOING) { 1748 /* Special case: outgoing packets have ll header at head */ 1749 skb_pull(skb, skb_network_offset(skb)); 1750 } 1751 } 1752 1753 if (skb->ip_summed == CHECKSUM_PARTIAL) 1754 status |= TP_STATUS_CSUMNOTREADY; 1755 1756 snaplen = skb->len; 1757 1758 res = run_filter(skb, sk, snaplen); 1759 if (!res) 1760 goto drop_n_restore; 1761 if (snaplen > res) 1762 snaplen = res; 1763 1764 if (sk->sk_type == SOCK_DGRAM) { 1765 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1766 po->tp_reserve; 1767 } else { 1768 unsigned maclen = skb_network_offset(skb); 1769 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1770 (maclen < 16 ? 16 : maclen)) + 1771 po->tp_reserve; 1772 macoff = netoff - maclen; 1773 } 1774 if (po->tp_version <= TPACKET_V2) { 1775 if (macoff + snaplen > po->rx_ring.frame_size) { 1776 if (po->copy_thresh && 1777 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1778 if (skb_shared(skb)) { 1779 copy_skb = skb_clone(skb, GFP_ATOMIC); 1780 } else { 1781 copy_skb = skb_get(skb); 1782 skb_head = skb->data; 1783 } 1784 if (copy_skb) 1785 skb_set_owner_r(copy_skb, sk); 1786 } 1787 snaplen = po->rx_ring.frame_size - macoff; 1788 if ((int)snaplen < 0) 1789 snaplen = 0; 1790 } 1791 } 1792 spin_lock(&sk->sk_receive_queue.lock); 1793 h.raw = packet_current_rx_frame(po, skb, 1794 TP_STATUS_KERNEL, (macoff+snaplen)); 1795 if (!h.raw) 1796 goto ring_is_full; 1797 if (po->tp_version <= TPACKET_V2) { 1798 packet_increment_rx_head(po, &po->rx_ring); 1799 /* 1800 * LOSING will be reported till you read the stats, 1801 * because it's COR - Clear On Read. 1802 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1803 * at packet level. 1804 */ 1805 if (po->stats.tp_drops) 1806 status |= TP_STATUS_LOSING; 1807 } 1808 po->stats.tp_packets++; 1809 if (copy_skb) { 1810 status |= TP_STATUS_COPY; 1811 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1812 } 1813 spin_unlock(&sk->sk_receive_queue.lock); 1814 1815 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1816 1817 switch (po->tp_version) { 1818 case TPACKET_V1: 1819 h.h1->tp_len = skb->len; 1820 h.h1->tp_snaplen = snaplen; 1821 h.h1->tp_mac = macoff; 1822 h.h1->tp_net = netoff; 1823 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1824 && shhwtstamps->syststamp.tv64) 1825 tv = ktime_to_timeval(shhwtstamps->syststamp); 1826 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1827 && shhwtstamps->hwtstamp.tv64) 1828 tv = ktime_to_timeval(shhwtstamps->hwtstamp); 1829 else if (skb->tstamp.tv64) 1830 tv = ktime_to_timeval(skb->tstamp); 1831 else 1832 do_gettimeofday(&tv); 1833 h.h1->tp_sec = tv.tv_sec; 1834 h.h1->tp_usec = tv.tv_usec; 1835 hdrlen = sizeof(*h.h1); 1836 break; 1837 case TPACKET_V2: 1838 h.h2->tp_len = skb->len; 1839 h.h2->tp_snaplen = snaplen; 1840 h.h2->tp_mac = macoff; 1841 h.h2->tp_net = netoff; 1842 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1843 && shhwtstamps->syststamp.tv64) 1844 ts = ktime_to_timespec(shhwtstamps->syststamp); 1845 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1846 && shhwtstamps->hwtstamp.tv64) 1847 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1848 else if (skb->tstamp.tv64) 1849 ts = ktime_to_timespec(skb->tstamp); 1850 else 1851 getnstimeofday(&ts); 1852 h.h2->tp_sec = ts.tv_sec; 1853 h.h2->tp_nsec = ts.tv_nsec; 1854 if (vlan_tx_tag_present(skb)) { 1855 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1856 status |= TP_STATUS_VLAN_VALID; 1857 } else { 1858 h.h2->tp_vlan_tci = 0; 1859 } 1860 h.h2->tp_padding = 0; 1861 hdrlen = sizeof(*h.h2); 1862 break; 1863 case TPACKET_V3: 1864 /* tp_nxt_offset,vlan are already populated above. 1865 * So DONT clear those fields here 1866 */ 1867 h.h3->tp_status |= status; 1868 h.h3->tp_len = skb->len; 1869 h.h3->tp_snaplen = snaplen; 1870 h.h3->tp_mac = macoff; 1871 h.h3->tp_net = netoff; 1872 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1873 && shhwtstamps->syststamp.tv64) 1874 ts = ktime_to_timespec(shhwtstamps->syststamp); 1875 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1876 && shhwtstamps->hwtstamp.tv64) 1877 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1878 else if (skb->tstamp.tv64) 1879 ts = ktime_to_timespec(skb->tstamp); 1880 else 1881 getnstimeofday(&ts); 1882 h.h3->tp_sec = ts.tv_sec; 1883 h.h3->tp_nsec = ts.tv_nsec; 1884 hdrlen = sizeof(*h.h3); 1885 break; 1886 default: 1887 BUG(); 1888 } 1889 1890 sll = h.raw + TPACKET_ALIGN(hdrlen); 1891 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1892 sll->sll_family = AF_PACKET; 1893 sll->sll_hatype = dev->type; 1894 sll->sll_protocol = skb->protocol; 1895 sll->sll_pkttype = skb->pkt_type; 1896 if (unlikely(po->origdev)) 1897 sll->sll_ifindex = orig_dev->ifindex; 1898 else 1899 sll->sll_ifindex = dev->ifindex; 1900 1901 smp_mb(); 1902 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1903 { 1904 u8 *start, *end; 1905 1906 if (po->tp_version <= TPACKET_V2) { 1907 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1908 + macoff + snaplen); 1909 for (start = h.raw; start < end; start += PAGE_SIZE) 1910 flush_dcache_page(pgv_to_page(start)); 1911 } 1912 smp_wmb(); 1913 } 1914 #endif 1915 if (po->tp_version <= TPACKET_V2) 1916 __packet_set_status(po, h.raw, status); 1917 else 1918 prb_clear_blk_fill_status(&po->rx_ring); 1919 1920 sk->sk_data_ready(sk, 0); 1921 1922 drop_n_restore: 1923 if (skb_head != skb->data && skb_shared(skb)) { 1924 skb->data = skb_head; 1925 skb->len = skb_len; 1926 } 1927 drop: 1928 kfree_skb(skb); 1929 return 0; 1930 1931 ring_is_full: 1932 po->stats.tp_drops++; 1933 spin_unlock(&sk->sk_receive_queue.lock); 1934 1935 sk->sk_data_ready(sk, 0); 1936 kfree_skb(copy_skb); 1937 goto drop_n_restore; 1938 } 1939 1940 static void tpacket_destruct_skb(struct sk_buff *skb) 1941 { 1942 struct packet_sock *po = pkt_sk(skb->sk); 1943 void *ph; 1944 1945 if (likely(po->tx_ring.pg_vec)) { 1946 ph = skb_shinfo(skb)->destructor_arg; 1947 BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING); 1948 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1949 atomic_dec(&po->tx_ring.pending); 1950 __packet_set_status(po, ph, TP_STATUS_AVAILABLE); 1951 } 1952 1953 sock_wfree(skb); 1954 } 1955 1956 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1957 void *frame, struct net_device *dev, int size_max, 1958 __be16 proto, unsigned char *addr, int hlen) 1959 { 1960 union { 1961 struct tpacket_hdr *h1; 1962 struct tpacket2_hdr *h2; 1963 void *raw; 1964 } ph; 1965 int to_write, offset, len, tp_len, nr_frags, len_max; 1966 struct socket *sock = po->sk.sk_socket; 1967 struct page *page; 1968 void *data; 1969 int err; 1970 1971 ph.raw = frame; 1972 1973 skb->protocol = proto; 1974 skb->dev = dev; 1975 skb->priority = po->sk.sk_priority; 1976 skb->mark = po->sk.sk_mark; 1977 skb_shinfo(skb)->destructor_arg = ph.raw; 1978 1979 switch (po->tp_version) { 1980 case TPACKET_V2: 1981 tp_len = ph.h2->tp_len; 1982 break; 1983 default: 1984 tp_len = ph.h1->tp_len; 1985 break; 1986 } 1987 if (unlikely(tp_len > size_max)) { 1988 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1989 return -EMSGSIZE; 1990 } 1991 1992 skb_reserve(skb, hlen); 1993 skb_reset_network_header(skb); 1994 1995 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1996 to_write = tp_len; 1997 1998 if (sock->type == SOCK_DGRAM) { 1999 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2000 NULL, tp_len); 2001 if (unlikely(err < 0)) 2002 return -EINVAL; 2003 } else if (dev->hard_header_len) { 2004 /* net device doesn't like empty head */ 2005 if (unlikely(tp_len <= dev->hard_header_len)) { 2006 pr_err("packet size is too short (%d < %d)\n", 2007 tp_len, dev->hard_header_len); 2008 return -EINVAL; 2009 } 2010 2011 skb_push(skb, dev->hard_header_len); 2012 err = skb_store_bits(skb, 0, data, 2013 dev->hard_header_len); 2014 if (unlikely(err)) 2015 return err; 2016 2017 data += dev->hard_header_len; 2018 to_write -= dev->hard_header_len; 2019 } 2020 2021 err = -EFAULT; 2022 offset = offset_in_page(data); 2023 len_max = PAGE_SIZE - offset; 2024 len = ((to_write > len_max) ? len_max : to_write); 2025 2026 skb->data_len = to_write; 2027 skb->len += to_write; 2028 skb->truesize += to_write; 2029 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2030 2031 while (likely(to_write)) { 2032 nr_frags = skb_shinfo(skb)->nr_frags; 2033 2034 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2035 pr_err("Packet exceed the number of skb frags(%lu)\n", 2036 MAX_SKB_FRAGS); 2037 return -EFAULT; 2038 } 2039 2040 page = pgv_to_page(data); 2041 data += len; 2042 flush_dcache_page(page); 2043 get_page(page); 2044 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2045 to_write -= len; 2046 offset = 0; 2047 len_max = PAGE_SIZE; 2048 len = ((to_write > len_max) ? len_max : to_write); 2049 } 2050 2051 return tp_len; 2052 } 2053 2054 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2055 { 2056 struct sk_buff *skb; 2057 struct net_device *dev; 2058 __be16 proto; 2059 bool need_rls_dev = false; 2060 int err, reserve = 0; 2061 void *ph; 2062 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2063 int tp_len, size_max; 2064 unsigned char *addr; 2065 int len_sum = 0; 2066 int status = 0; 2067 int hlen, tlen; 2068 2069 mutex_lock(&po->pg_vec_lock); 2070 2071 err = -EBUSY; 2072 if (saddr == NULL) { 2073 dev = po->prot_hook.dev; 2074 proto = po->num; 2075 addr = NULL; 2076 } else { 2077 err = -EINVAL; 2078 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2079 goto out; 2080 if (msg->msg_namelen < (saddr->sll_halen 2081 + offsetof(struct sockaddr_ll, 2082 sll_addr))) 2083 goto out; 2084 proto = saddr->sll_protocol; 2085 addr = saddr->sll_addr; 2086 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2087 need_rls_dev = true; 2088 } 2089 2090 err = -ENXIO; 2091 if (unlikely(dev == NULL)) 2092 goto out; 2093 2094 reserve = dev->hard_header_len; 2095 2096 err = -ENETDOWN; 2097 if (unlikely(!(dev->flags & IFF_UP))) 2098 goto out_put; 2099 2100 size_max = po->tx_ring.frame_size 2101 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2102 2103 if (size_max > dev->mtu + reserve) 2104 size_max = dev->mtu + reserve; 2105 2106 do { 2107 ph = packet_current_frame(po, &po->tx_ring, 2108 TP_STATUS_SEND_REQUEST); 2109 2110 if (unlikely(ph == NULL)) { 2111 schedule(); 2112 continue; 2113 } 2114 2115 status = TP_STATUS_SEND_REQUEST; 2116 hlen = LL_RESERVED_SPACE(dev); 2117 tlen = dev->needed_tailroom; 2118 skb = sock_alloc_send_skb(&po->sk, 2119 hlen + tlen + sizeof(struct sockaddr_ll), 2120 0, &err); 2121 2122 if (unlikely(skb == NULL)) 2123 goto out_status; 2124 2125 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2126 addr, hlen); 2127 2128 if (unlikely(tp_len < 0)) { 2129 if (po->tp_loss) { 2130 __packet_set_status(po, ph, 2131 TP_STATUS_AVAILABLE); 2132 packet_increment_head(&po->tx_ring); 2133 kfree_skb(skb); 2134 continue; 2135 } else { 2136 status = TP_STATUS_WRONG_FORMAT; 2137 err = tp_len; 2138 goto out_status; 2139 } 2140 } 2141 2142 skb->destructor = tpacket_destruct_skb; 2143 __packet_set_status(po, ph, TP_STATUS_SENDING); 2144 atomic_inc(&po->tx_ring.pending); 2145 2146 status = TP_STATUS_SEND_REQUEST; 2147 err = dev_queue_xmit(skb); 2148 if (unlikely(err > 0)) { 2149 err = net_xmit_errno(err); 2150 if (err && __packet_get_status(po, ph) == 2151 TP_STATUS_AVAILABLE) { 2152 /* skb was destructed already */ 2153 skb = NULL; 2154 goto out_status; 2155 } 2156 /* 2157 * skb was dropped but not destructed yet; 2158 * let's treat it like congestion or err < 0 2159 */ 2160 err = 0; 2161 } 2162 packet_increment_head(&po->tx_ring); 2163 len_sum += tp_len; 2164 } while (likely((ph != NULL) || 2165 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2166 (atomic_read(&po->tx_ring.pending)))) 2167 ); 2168 2169 err = len_sum; 2170 goto out_put; 2171 2172 out_status: 2173 __packet_set_status(po, ph, status); 2174 kfree_skb(skb); 2175 out_put: 2176 if (need_rls_dev) 2177 dev_put(dev); 2178 out: 2179 mutex_unlock(&po->pg_vec_lock); 2180 return err; 2181 } 2182 2183 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2184 size_t reserve, size_t len, 2185 size_t linear, int noblock, 2186 int *err) 2187 { 2188 struct sk_buff *skb; 2189 2190 /* Under a page? Don't bother with paged skb. */ 2191 if (prepad + len < PAGE_SIZE || !linear) 2192 linear = len; 2193 2194 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2195 err); 2196 if (!skb) 2197 return NULL; 2198 2199 skb_reserve(skb, reserve); 2200 skb_put(skb, linear); 2201 skb->data_len = len - linear; 2202 skb->len += len - linear; 2203 2204 return skb; 2205 } 2206 2207 static int packet_snd(struct socket *sock, 2208 struct msghdr *msg, size_t len) 2209 { 2210 struct sock *sk = sock->sk; 2211 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2212 struct sk_buff *skb; 2213 struct net_device *dev; 2214 __be16 proto; 2215 bool need_rls_dev = false; 2216 unsigned char *addr; 2217 int err, reserve = 0; 2218 struct virtio_net_hdr vnet_hdr = { 0 }; 2219 int offset = 0; 2220 int vnet_hdr_len; 2221 struct packet_sock *po = pkt_sk(sk); 2222 unsigned short gso_type = 0; 2223 int hlen, tlen; 2224 int extra_len = 0; 2225 2226 /* 2227 * Get and verify the address. 2228 */ 2229 2230 if (saddr == NULL) { 2231 dev = po->prot_hook.dev; 2232 proto = po->num; 2233 addr = NULL; 2234 } else { 2235 err = -EINVAL; 2236 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2237 goto out; 2238 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2239 goto out; 2240 proto = saddr->sll_protocol; 2241 addr = saddr->sll_addr; 2242 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2243 need_rls_dev = true; 2244 } 2245 2246 err = -ENXIO; 2247 if (dev == NULL) 2248 goto out_unlock; 2249 if (sock->type == SOCK_RAW) 2250 reserve = dev->hard_header_len; 2251 2252 err = -ENETDOWN; 2253 if (!(dev->flags & IFF_UP)) 2254 goto out_unlock; 2255 2256 if (po->has_vnet_hdr) { 2257 vnet_hdr_len = sizeof(vnet_hdr); 2258 2259 err = -EINVAL; 2260 if (len < vnet_hdr_len) 2261 goto out_unlock; 2262 2263 len -= vnet_hdr_len; 2264 2265 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2266 vnet_hdr_len); 2267 if (err < 0) 2268 goto out_unlock; 2269 2270 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2271 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2272 vnet_hdr.hdr_len)) 2273 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2274 vnet_hdr.csum_offset + 2; 2275 2276 err = -EINVAL; 2277 if (vnet_hdr.hdr_len > len) 2278 goto out_unlock; 2279 2280 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2281 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2282 case VIRTIO_NET_HDR_GSO_TCPV4: 2283 gso_type = SKB_GSO_TCPV4; 2284 break; 2285 case VIRTIO_NET_HDR_GSO_TCPV6: 2286 gso_type = SKB_GSO_TCPV6; 2287 break; 2288 case VIRTIO_NET_HDR_GSO_UDP: 2289 gso_type = SKB_GSO_UDP; 2290 break; 2291 default: 2292 goto out_unlock; 2293 } 2294 2295 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2296 gso_type |= SKB_GSO_TCP_ECN; 2297 2298 if (vnet_hdr.gso_size == 0) 2299 goto out_unlock; 2300 2301 } 2302 } 2303 2304 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2305 if (!netif_supports_nofcs(dev)) { 2306 err = -EPROTONOSUPPORT; 2307 goto out_unlock; 2308 } 2309 extra_len = 4; /* We're doing our own CRC */ 2310 } 2311 2312 err = -EMSGSIZE; 2313 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2314 goto out_unlock; 2315 2316 err = -ENOBUFS; 2317 hlen = LL_RESERVED_SPACE(dev); 2318 tlen = dev->needed_tailroom; 2319 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2320 msg->msg_flags & MSG_DONTWAIT, &err); 2321 if (skb == NULL) 2322 goto out_unlock; 2323 2324 skb_set_network_header(skb, reserve); 2325 2326 err = -EINVAL; 2327 if (sock->type == SOCK_DGRAM && 2328 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2329 goto out_free; 2330 2331 /* Returns -EFAULT on error */ 2332 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2333 if (err) 2334 goto out_free; 2335 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2336 if (err < 0) 2337 goto out_free; 2338 2339 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2340 /* Earlier code assumed this would be a VLAN pkt, 2341 * double-check this now that we have the actual 2342 * packet in hand. 2343 */ 2344 struct ethhdr *ehdr; 2345 skb_reset_mac_header(skb); 2346 ehdr = eth_hdr(skb); 2347 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2348 err = -EMSGSIZE; 2349 goto out_free; 2350 } 2351 } 2352 2353 skb->protocol = proto; 2354 skb->dev = dev; 2355 skb->priority = sk->sk_priority; 2356 skb->mark = sk->sk_mark; 2357 2358 if (po->has_vnet_hdr) { 2359 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2360 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2361 vnet_hdr.csum_offset)) { 2362 err = -EINVAL; 2363 goto out_free; 2364 } 2365 } 2366 2367 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2368 skb_shinfo(skb)->gso_type = gso_type; 2369 2370 /* Header must be checked, and gso_segs computed. */ 2371 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2372 skb_shinfo(skb)->gso_segs = 0; 2373 2374 len += vnet_hdr_len; 2375 } 2376 2377 if (unlikely(extra_len == 4)) 2378 skb->no_fcs = 1; 2379 2380 /* 2381 * Now send it 2382 */ 2383 2384 err = dev_queue_xmit(skb); 2385 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2386 goto out_unlock; 2387 2388 if (need_rls_dev) 2389 dev_put(dev); 2390 2391 return len; 2392 2393 out_free: 2394 kfree_skb(skb); 2395 out_unlock: 2396 if (dev && need_rls_dev) 2397 dev_put(dev); 2398 out: 2399 return err; 2400 } 2401 2402 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2403 struct msghdr *msg, size_t len) 2404 { 2405 struct sock *sk = sock->sk; 2406 struct packet_sock *po = pkt_sk(sk); 2407 if (po->tx_ring.pg_vec) 2408 return tpacket_snd(po, msg); 2409 else 2410 return packet_snd(sock, msg, len); 2411 } 2412 2413 /* 2414 * Close a PACKET socket. This is fairly simple. We immediately go 2415 * to 'closed' state and remove our protocol entry in the device list. 2416 */ 2417 2418 static int packet_release(struct socket *sock) 2419 { 2420 struct sock *sk = sock->sk; 2421 struct packet_sock *po; 2422 struct net *net; 2423 union tpacket_req_u req_u; 2424 2425 if (!sk) 2426 return 0; 2427 2428 net = sock_net(sk); 2429 po = pkt_sk(sk); 2430 2431 spin_lock_bh(&net->packet.sklist_lock); 2432 sk_del_node_init_rcu(sk); 2433 sock_prot_inuse_add(net, sk->sk_prot, -1); 2434 spin_unlock_bh(&net->packet.sklist_lock); 2435 2436 spin_lock(&po->bind_lock); 2437 unregister_prot_hook(sk, false); 2438 if (po->prot_hook.dev) { 2439 dev_put(po->prot_hook.dev); 2440 po->prot_hook.dev = NULL; 2441 } 2442 spin_unlock(&po->bind_lock); 2443 2444 packet_flush_mclist(sk); 2445 2446 memset(&req_u, 0, sizeof(req_u)); 2447 2448 if (po->rx_ring.pg_vec) 2449 packet_set_ring(sk, &req_u, 1, 0); 2450 2451 if (po->tx_ring.pg_vec) 2452 packet_set_ring(sk, &req_u, 1, 1); 2453 2454 fanout_release(sk); 2455 2456 synchronize_net(); 2457 /* 2458 * Now the socket is dead. No more input will appear. 2459 */ 2460 sock_orphan(sk); 2461 sock->sk = NULL; 2462 2463 /* Purge queues */ 2464 2465 skb_queue_purge(&sk->sk_receive_queue); 2466 sk_refcnt_debug_release(sk); 2467 2468 sock_put(sk); 2469 return 0; 2470 } 2471 2472 /* 2473 * Attach a packet hook. 2474 */ 2475 2476 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2477 { 2478 struct packet_sock *po = pkt_sk(sk); 2479 2480 if (po->fanout) { 2481 if (dev) 2482 dev_put(dev); 2483 2484 return -EINVAL; 2485 } 2486 2487 lock_sock(sk); 2488 2489 spin_lock(&po->bind_lock); 2490 unregister_prot_hook(sk, true); 2491 po->num = protocol; 2492 po->prot_hook.type = protocol; 2493 if (po->prot_hook.dev) 2494 dev_put(po->prot_hook.dev); 2495 po->prot_hook.dev = dev; 2496 2497 po->ifindex = dev ? dev->ifindex : 0; 2498 2499 if (protocol == 0) 2500 goto out_unlock; 2501 2502 if (!dev || (dev->flags & IFF_UP)) { 2503 register_prot_hook(sk); 2504 } else { 2505 sk->sk_err = ENETDOWN; 2506 if (!sock_flag(sk, SOCK_DEAD)) 2507 sk->sk_error_report(sk); 2508 } 2509 2510 out_unlock: 2511 spin_unlock(&po->bind_lock); 2512 release_sock(sk); 2513 return 0; 2514 } 2515 2516 /* 2517 * Bind a packet socket to a device 2518 */ 2519 2520 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2521 int addr_len) 2522 { 2523 struct sock *sk = sock->sk; 2524 char name[15]; 2525 struct net_device *dev; 2526 int err = -ENODEV; 2527 2528 /* 2529 * Check legality 2530 */ 2531 2532 if (addr_len != sizeof(struct sockaddr)) 2533 return -EINVAL; 2534 strlcpy(name, uaddr->sa_data, sizeof(name)); 2535 2536 dev = dev_get_by_name(sock_net(sk), name); 2537 if (dev) 2538 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2539 return err; 2540 } 2541 2542 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2543 { 2544 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2545 struct sock *sk = sock->sk; 2546 struct net_device *dev = NULL; 2547 int err; 2548 2549 2550 /* 2551 * Check legality 2552 */ 2553 2554 if (addr_len < sizeof(struct sockaddr_ll)) 2555 return -EINVAL; 2556 if (sll->sll_family != AF_PACKET) 2557 return -EINVAL; 2558 2559 if (sll->sll_ifindex) { 2560 err = -ENODEV; 2561 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2562 if (dev == NULL) 2563 goto out; 2564 } 2565 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2566 2567 out: 2568 return err; 2569 } 2570 2571 static struct proto packet_proto = { 2572 .name = "PACKET", 2573 .owner = THIS_MODULE, 2574 .obj_size = sizeof(struct packet_sock), 2575 }; 2576 2577 /* 2578 * Create a packet of type SOCK_PACKET. 2579 */ 2580 2581 static int packet_create(struct net *net, struct socket *sock, int protocol, 2582 int kern) 2583 { 2584 struct sock *sk; 2585 struct packet_sock *po; 2586 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2587 int err; 2588 2589 if (!capable(CAP_NET_RAW)) 2590 return -EPERM; 2591 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2592 sock->type != SOCK_PACKET) 2593 return -ESOCKTNOSUPPORT; 2594 2595 sock->state = SS_UNCONNECTED; 2596 2597 err = -ENOBUFS; 2598 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2599 if (sk == NULL) 2600 goto out; 2601 2602 sock->ops = &packet_ops; 2603 if (sock->type == SOCK_PACKET) 2604 sock->ops = &packet_ops_spkt; 2605 2606 sock_init_data(sock, sk); 2607 2608 po = pkt_sk(sk); 2609 sk->sk_family = PF_PACKET; 2610 po->num = proto; 2611 2612 sk->sk_destruct = packet_sock_destruct; 2613 sk_refcnt_debug_inc(sk); 2614 2615 /* 2616 * Attach a protocol block 2617 */ 2618 2619 spin_lock_init(&po->bind_lock); 2620 mutex_init(&po->pg_vec_lock); 2621 po->prot_hook.func = packet_rcv; 2622 2623 if (sock->type == SOCK_PACKET) 2624 po->prot_hook.func = packet_rcv_spkt; 2625 2626 po->prot_hook.af_packet_priv = sk; 2627 2628 if (proto) { 2629 po->prot_hook.type = proto; 2630 register_prot_hook(sk); 2631 } 2632 2633 spin_lock_bh(&net->packet.sklist_lock); 2634 sk_add_node_rcu(sk, &net->packet.sklist); 2635 sock_prot_inuse_add(net, &packet_proto, 1); 2636 spin_unlock_bh(&net->packet.sklist_lock); 2637 2638 return 0; 2639 out: 2640 return err; 2641 } 2642 2643 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2644 { 2645 struct sock_exterr_skb *serr; 2646 struct sk_buff *skb, *skb2; 2647 int copied, err; 2648 2649 err = -EAGAIN; 2650 skb = skb_dequeue(&sk->sk_error_queue); 2651 if (skb == NULL) 2652 goto out; 2653 2654 copied = skb->len; 2655 if (copied > len) { 2656 msg->msg_flags |= MSG_TRUNC; 2657 copied = len; 2658 } 2659 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2660 if (err) 2661 goto out_free_skb; 2662 2663 sock_recv_timestamp(msg, sk, skb); 2664 2665 serr = SKB_EXT_ERR(skb); 2666 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2667 sizeof(serr->ee), &serr->ee); 2668 2669 msg->msg_flags |= MSG_ERRQUEUE; 2670 err = copied; 2671 2672 /* Reset and regenerate socket error */ 2673 spin_lock_bh(&sk->sk_error_queue.lock); 2674 sk->sk_err = 0; 2675 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2676 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2677 spin_unlock_bh(&sk->sk_error_queue.lock); 2678 sk->sk_error_report(sk); 2679 } else 2680 spin_unlock_bh(&sk->sk_error_queue.lock); 2681 2682 out_free_skb: 2683 kfree_skb(skb); 2684 out: 2685 return err; 2686 } 2687 2688 /* 2689 * Pull a packet from our receive queue and hand it to the user. 2690 * If necessary we block. 2691 */ 2692 2693 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2694 struct msghdr *msg, size_t len, int flags) 2695 { 2696 struct sock *sk = sock->sk; 2697 struct sk_buff *skb; 2698 int copied, err; 2699 struct sockaddr_ll *sll; 2700 int vnet_hdr_len = 0; 2701 2702 err = -EINVAL; 2703 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2704 goto out; 2705 2706 #if 0 2707 /* What error should we return now? EUNATTACH? */ 2708 if (pkt_sk(sk)->ifindex < 0) 2709 return -ENODEV; 2710 #endif 2711 2712 if (flags & MSG_ERRQUEUE) { 2713 err = packet_recv_error(sk, msg, len); 2714 goto out; 2715 } 2716 2717 /* 2718 * Call the generic datagram receiver. This handles all sorts 2719 * of horrible races and re-entrancy so we can forget about it 2720 * in the protocol layers. 2721 * 2722 * Now it will return ENETDOWN, if device have just gone down, 2723 * but then it will block. 2724 */ 2725 2726 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2727 2728 /* 2729 * An error occurred so return it. Because skb_recv_datagram() 2730 * handles the blocking we don't see and worry about blocking 2731 * retries. 2732 */ 2733 2734 if (skb == NULL) 2735 goto out; 2736 2737 if (pkt_sk(sk)->has_vnet_hdr) { 2738 struct virtio_net_hdr vnet_hdr = { 0 }; 2739 2740 err = -EINVAL; 2741 vnet_hdr_len = sizeof(vnet_hdr); 2742 if (len < vnet_hdr_len) 2743 goto out_free; 2744 2745 len -= vnet_hdr_len; 2746 2747 if (skb_is_gso(skb)) { 2748 struct skb_shared_info *sinfo = skb_shinfo(skb); 2749 2750 /* This is a hint as to how much should be linear. */ 2751 vnet_hdr.hdr_len = skb_headlen(skb); 2752 vnet_hdr.gso_size = sinfo->gso_size; 2753 if (sinfo->gso_type & SKB_GSO_TCPV4) 2754 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2755 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2756 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2757 else if (sinfo->gso_type & SKB_GSO_UDP) 2758 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2759 else if (sinfo->gso_type & SKB_GSO_FCOE) 2760 goto out_free; 2761 else 2762 BUG(); 2763 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2764 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2765 } else 2766 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2767 2768 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2769 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2770 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2771 vnet_hdr.csum_offset = skb->csum_offset; 2772 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2773 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2774 } /* else everything is zero */ 2775 2776 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2777 vnet_hdr_len); 2778 if (err < 0) 2779 goto out_free; 2780 } 2781 2782 /* 2783 * If the address length field is there to be filled in, we fill 2784 * it in now. 2785 */ 2786 2787 sll = &PACKET_SKB_CB(skb)->sa.ll; 2788 if (sock->type == SOCK_PACKET) 2789 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2790 else 2791 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2792 2793 /* 2794 * You lose any data beyond the buffer you gave. If it worries a 2795 * user program they can ask the device for its MTU anyway. 2796 */ 2797 2798 copied = skb->len; 2799 if (copied > len) { 2800 copied = len; 2801 msg->msg_flags |= MSG_TRUNC; 2802 } 2803 2804 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2805 if (err) 2806 goto out_free; 2807 2808 sock_recv_ts_and_drops(msg, sk, skb); 2809 2810 if (msg->msg_name) 2811 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2812 msg->msg_namelen); 2813 2814 if (pkt_sk(sk)->auxdata) { 2815 struct tpacket_auxdata aux; 2816 2817 aux.tp_status = TP_STATUS_USER; 2818 if (skb->ip_summed == CHECKSUM_PARTIAL) 2819 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2820 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2821 aux.tp_snaplen = skb->len; 2822 aux.tp_mac = 0; 2823 aux.tp_net = skb_network_offset(skb); 2824 if (vlan_tx_tag_present(skb)) { 2825 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2826 aux.tp_status |= TP_STATUS_VLAN_VALID; 2827 } else { 2828 aux.tp_vlan_tci = 0; 2829 } 2830 aux.tp_padding = 0; 2831 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2832 } 2833 2834 /* 2835 * Free or return the buffer as appropriate. Again this 2836 * hides all the races and re-entrancy issues from us. 2837 */ 2838 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2839 2840 out_free: 2841 skb_free_datagram(sk, skb); 2842 out: 2843 return err; 2844 } 2845 2846 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2847 int *uaddr_len, int peer) 2848 { 2849 struct net_device *dev; 2850 struct sock *sk = sock->sk; 2851 2852 if (peer) 2853 return -EOPNOTSUPP; 2854 2855 uaddr->sa_family = AF_PACKET; 2856 rcu_read_lock(); 2857 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2858 if (dev) 2859 strncpy(uaddr->sa_data, dev->name, 14); 2860 else 2861 memset(uaddr->sa_data, 0, 14); 2862 rcu_read_unlock(); 2863 *uaddr_len = sizeof(*uaddr); 2864 2865 return 0; 2866 } 2867 2868 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2869 int *uaddr_len, int peer) 2870 { 2871 struct net_device *dev; 2872 struct sock *sk = sock->sk; 2873 struct packet_sock *po = pkt_sk(sk); 2874 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2875 2876 if (peer) 2877 return -EOPNOTSUPP; 2878 2879 sll->sll_family = AF_PACKET; 2880 sll->sll_ifindex = po->ifindex; 2881 sll->sll_protocol = po->num; 2882 sll->sll_pkttype = 0; 2883 rcu_read_lock(); 2884 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2885 if (dev) { 2886 sll->sll_hatype = dev->type; 2887 sll->sll_halen = dev->addr_len; 2888 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2889 } else { 2890 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2891 sll->sll_halen = 0; 2892 } 2893 rcu_read_unlock(); 2894 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2895 2896 return 0; 2897 } 2898 2899 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2900 int what) 2901 { 2902 switch (i->type) { 2903 case PACKET_MR_MULTICAST: 2904 if (i->alen != dev->addr_len) 2905 return -EINVAL; 2906 if (what > 0) 2907 return dev_mc_add(dev, i->addr); 2908 else 2909 return dev_mc_del(dev, i->addr); 2910 break; 2911 case PACKET_MR_PROMISC: 2912 return dev_set_promiscuity(dev, what); 2913 break; 2914 case PACKET_MR_ALLMULTI: 2915 return dev_set_allmulti(dev, what); 2916 break; 2917 case PACKET_MR_UNICAST: 2918 if (i->alen != dev->addr_len) 2919 return -EINVAL; 2920 if (what > 0) 2921 return dev_uc_add(dev, i->addr); 2922 else 2923 return dev_uc_del(dev, i->addr); 2924 break; 2925 default: 2926 break; 2927 } 2928 return 0; 2929 } 2930 2931 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2932 { 2933 for ( ; i; i = i->next) { 2934 if (i->ifindex == dev->ifindex) 2935 packet_dev_mc(dev, i, what); 2936 } 2937 } 2938 2939 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2940 { 2941 struct packet_sock *po = pkt_sk(sk); 2942 struct packet_mclist *ml, *i; 2943 struct net_device *dev; 2944 int err; 2945 2946 rtnl_lock(); 2947 2948 err = -ENODEV; 2949 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2950 if (!dev) 2951 goto done; 2952 2953 err = -EINVAL; 2954 if (mreq->mr_alen > dev->addr_len) 2955 goto done; 2956 2957 err = -ENOBUFS; 2958 i = kmalloc(sizeof(*i), GFP_KERNEL); 2959 if (i == NULL) 2960 goto done; 2961 2962 err = 0; 2963 for (ml = po->mclist; ml; ml = ml->next) { 2964 if (ml->ifindex == mreq->mr_ifindex && 2965 ml->type == mreq->mr_type && 2966 ml->alen == mreq->mr_alen && 2967 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2968 ml->count++; 2969 /* Free the new element ... */ 2970 kfree(i); 2971 goto done; 2972 } 2973 } 2974 2975 i->type = mreq->mr_type; 2976 i->ifindex = mreq->mr_ifindex; 2977 i->alen = mreq->mr_alen; 2978 memcpy(i->addr, mreq->mr_address, i->alen); 2979 i->count = 1; 2980 i->next = po->mclist; 2981 po->mclist = i; 2982 err = packet_dev_mc(dev, i, 1); 2983 if (err) { 2984 po->mclist = i->next; 2985 kfree(i); 2986 } 2987 2988 done: 2989 rtnl_unlock(); 2990 return err; 2991 } 2992 2993 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2994 { 2995 struct packet_mclist *ml, **mlp; 2996 2997 rtnl_lock(); 2998 2999 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3000 if (ml->ifindex == mreq->mr_ifindex && 3001 ml->type == mreq->mr_type && 3002 ml->alen == mreq->mr_alen && 3003 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3004 if (--ml->count == 0) { 3005 struct net_device *dev; 3006 *mlp = ml->next; 3007 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3008 if (dev) 3009 packet_dev_mc(dev, ml, -1); 3010 kfree(ml); 3011 } 3012 rtnl_unlock(); 3013 return 0; 3014 } 3015 } 3016 rtnl_unlock(); 3017 return -EADDRNOTAVAIL; 3018 } 3019 3020 static void packet_flush_mclist(struct sock *sk) 3021 { 3022 struct packet_sock *po = pkt_sk(sk); 3023 struct packet_mclist *ml; 3024 3025 if (!po->mclist) 3026 return; 3027 3028 rtnl_lock(); 3029 while ((ml = po->mclist) != NULL) { 3030 struct net_device *dev; 3031 3032 po->mclist = ml->next; 3033 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3034 if (dev != NULL) 3035 packet_dev_mc(dev, ml, -1); 3036 kfree(ml); 3037 } 3038 rtnl_unlock(); 3039 } 3040 3041 static int 3042 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3043 { 3044 struct sock *sk = sock->sk; 3045 struct packet_sock *po = pkt_sk(sk); 3046 int ret; 3047 3048 if (level != SOL_PACKET) 3049 return -ENOPROTOOPT; 3050 3051 switch (optname) { 3052 case PACKET_ADD_MEMBERSHIP: 3053 case PACKET_DROP_MEMBERSHIP: 3054 { 3055 struct packet_mreq_max mreq; 3056 int len = optlen; 3057 memset(&mreq, 0, sizeof(mreq)); 3058 if (len < sizeof(struct packet_mreq)) 3059 return -EINVAL; 3060 if (len > sizeof(mreq)) 3061 len = sizeof(mreq); 3062 if (copy_from_user(&mreq, optval, len)) 3063 return -EFAULT; 3064 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3065 return -EINVAL; 3066 if (optname == PACKET_ADD_MEMBERSHIP) 3067 ret = packet_mc_add(sk, &mreq); 3068 else 3069 ret = packet_mc_drop(sk, &mreq); 3070 return ret; 3071 } 3072 3073 case PACKET_RX_RING: 3074 case PACKET_TX_RING: 3075 { 3076 union tpacket_req_u req_u; 3077 int len; 3078 3079 switch (po->tp_version) { 3080 case TPACKET_V1: 3081 case TPACKET_V2: 3082 len = sizeof(req_u.req); 3083 break; 3084 case TPACKET_V3: 3085 default: 3086 len = sizeof(req_u.req3); 3087 break; 3088 } 3089 if (optlen < len) 3090 return -EINVAL; 3091 if (pkt_sk(sk)->has_vnet_hdr) 3092 return -EINVAL; 3093 if (copy_from_user(&req_u.req, optval, len)) 3094 return -EFAULT; 3095 return packet_set_ring(sk, &req_u, 0, 3096 optname == PACKET_TX_RING); 3097 } 3098 case PACKET_COPY_THRESH: 3099 { 3100 int val; 3101 3102 if (optlen != sizeof(val)) 3103 return -EINVAL; 3104 if (copy_from_user(&val, optval, sizeof(val))) 3105 return -EFAULT; 3106 3107 pkt_sk(sk)->copy_thresh = val; 3108 return 0; 3109 } 3110 case PACKET_VERSION: 3111 { 3112 int val; 3113 3114 if (optlen != sizeof(val)) 3115 return -EINVAL; 3116 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3117 return -EBUSY; 3118 if (copy_from_user(&val, optval, sizeof(val))) 3119 return -EFAULT; 3120 switch (val) { 3121 case TPACKET_V1: 3122 case TPACKET_V2: 3123 case TPACKET_V3: 3124 po->tp_version = val; 3125 return 0; 3126 default: 3127 return -EINVAL; 3128 } 3129 } 3130 case PACKET_RESERVE: 3131 { 3132 unsigned int val; 3133 3134 if (optlen != sizeof(val)) 3135 return -EINVAL; 3136 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3137 return -EBUSY; 3138 if (copy_from_user(&val, optval, sizeof(val))) 3139 return -EFAULT; 3140 po->tp_reserve = val; 3141 return 0; 3142 } 3143 case PACKET_LOSS: 3144 { 3145 unsigned int val; 3146 3147 if (optlen != sizeof(val)) 3148 return -EINVAL; 3149 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3150 return -EBUSY; 3151 if (copy_from_user(&val, optval, sizeof(val))) 3152 return -EFAULT; 3153 po->tp_loss = !!val; 3154 return 0; 3155 } 3156 case PACKET_AUXDATA: 3157 { 3158 int val; 3159 3160 if (optlen < sizeof(val)) 3161 return -EINVAL; 3162 if (copy_from_user(&val, optval, sizeof(val))) 3163 return -EFAULT; 3164 3165 po->auxdata = !!val; 3166 return 0; 3167 } 3168 case PACKET_ORIGDEV: 3169 { 3170 int val; 3171 3172 if (optlen < sizeof(val)) 3173 return -EINVAL; 3174 if (copy_from_user(&val, optval, sizeof(val))) 3175 return -EFAULT; 3176 3177 po->origdev = !!val; 3178 return 0; 3179 } 3180 case PACKET_VNET_HDR: 3181 { 3182 int val; 3183 3184 if (sock->type != SOCK_RAW) 3185 return -EINVAL; 3186 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3187 return -EBUSY; 3188 if (optlen < sizeof(val)) 3189 return -EINVAL; 3190 if (copy_from_user(&val, optval, sizeof(val))) 3191 return -EFAULT; 3192 3193 po->has_vnet_hdr = !!val; 3194 return 0; 3195 } 3196 case PACKET_TIMESTAMP: 3197 { 3198 int val; 3199 3200 if (optlen != sizeof(val)) 3201 return -EINVAL; 3202 if (copy_from_user(&val, optval, sizeof(val))) 3203 return -EFAULT; 3204 3205 po->tp_tstamp = val; 3206 return 0; 3207 } 3208 case PACKET_FANOUT: 3209 { 3210 int val; 3211 3212 if (optlen != sizeof(val)) 3213 return -EINVAL; 3214 if (copy_from_user(&val, optval, sizeof(val))) 3215 return -EFAULT; 3216 3217 return fanout_add(sk, val & 0xffff, val >> 16); 3218 } 3219 default: 3220 return -ENOPROTOOPT; 3221 } 3222 } 3223 3224 static int packet_getsockopt(struct socket *sock, int level, int optname, 3225 char __user *optval, int __user *optlen) 3226 { 3227 int len; 3228 int val; 3229 struct sock *sk = sock->sk; 3230 struct packet_sock *po = pkt_sk(sk); 3231 void *data; 3232 struct tpacket_stats st; 3233 union tpacket_stats_u st_u; 3234 3235 if (level != SOL_PACKET) 3236 return -ENOPROTOOPT; 3237 3238 if (get_user(len, optlen)) 3239 return -EFAULT; 3240 3241 if (len < 0) 3242 return -EINVAL; 3243 3244 switch (optname) { 3245 case PACKET_STATISTICS: 3246 if (po->tp_version == TPACKET_V3) { 3247 len = sizeof(struct tpacket_stats_v3); 3248 } else { 3249 if (len > sizeof(struct tpacket_stats)) 3250 len = sizeof(struct tpacket_stats); 3251 } 3252 spin_lock_bh(&sk->sk_receive_queue.lock); 3253 if (po->tp_version == TPACKET_V3) { 3254 memcpy(&st_u.stats3, &po->stats, 3255 sizeof(struct tpacket_stats)); 3256 st_u.stats3.tp_freeze_q_cnt = 3257 po->stats_u.stats3.tp_freeze_q_cnt; 3258 st_u.stats3.tp_packets += po->stats.tp_drops; 3259 data = &st_u.stats3; 3260 } else { 3261 st = po->stats; 3262 st.tp_packets += st.tp_drops; 3263 data = &st; 3264 } 3265 memset(&po->stats, 0, sizeof(st)); 3266 spin_unlock_bh(&sk->sk_receive_queue.lock); 3267 break; 3268 case PACKET_AUXDATA: 3269 if (len > sizeof(int)) 3270 len = sizeof(int); 3271 val = po->auxdata; 3272 3273 data = &val; 3274 break; 3275 case PACKET_ORIGDEV: 3276 if (len > sizeof(int)) 3277 len = sizeof(int); 3278 val = po->origdev; 3279 3280 data = &val; 3281 break; 3282 case PACKET_VNET_HDR: 3283 if (len > sizeof(int)) 3284 len = sizeof(int); 3285 val = po->has_vnet_hdr; 3286 3287 data = &val; 3288 break; 3289 case PACKET_VERSION: 3290 if (len > sizeof(int)) 3291 len = sizeof(int); 3292 val = po->tp_version; 3293 data = &val; 3294 break; 3295 case PACKET_HDRLEN: 3296 if (len > sizeof(int)) 3297 len = sizeof(int); 3298 if (copy_from_user(&val, optval, len)) 3299 return -EFAULT; 3300 switch (val) { 3301 case TPACKET_V1: 3302 val = sizeof(struct tpacket_hdr); 3303 break; 3304 case TPACKET_V2: 3305 val = sizeof(struct tpacket2_hdr); 3306 break; 3307 case TPACKET_V3: 3308 val = sizeof(struct tpacket3_hdr); 3309 break; 3310 default: 3311 return -EINVAL; 3312 } 3313 data = &val; 3314 break; 3315 case PACKET_RESERVE: 3316 if (len > sizeof(unsigned int)) 3317 len = sizeof(unsigned int); 3318 val = po->tp_reserve; 3319 data = &val; 3320 break; 3321 case PACKET_LOSS: 3322 if (len > sizeof(unsigned int)) 3323 len = sizeof(unsigned int); 3324 val = po->tp_loss; 3325 data = &val; 3326 break; 3327 case PACKET_TIMESTAMP: 3328 if (len > sizeof(int)) 3329 len = sizeof(int); 3330 val = po->tp_tstamp; 3331 data = &val; 3332 break; 3333 case PACKET_FANOUT: 3334 if (len > sizeof(int)) 3335 len = sizeof(int); 3336 val = (po->fanout ? 3337 ((u32)po->fanout->id | 3338 ((u32)po->fanout->type << 16)) : 3339 0); 3340 data = &val; 3341 break; 3342 default: 3343 return -ENOPROTOOPT; 3344 } 3345 3346 if (put_user(len, optlen)) 3347 return -EFAULT; 3348 if (copy_to_user(optval, data, len)) 3349 return -EFAULT; 3350 return 0; 3351 } 3352 3353 3354 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3355 { 3356 struct sock *sk; 3357 struct hlist_node *node; 3358 struct net_device *dev = data; 3359 struct net *net = dev_net(dev); 3360 3361 rcu_read_lock(); 3362 sk_for_each_rcu(sk, node, &net->packet.sklist) { 3363 struct packet_sock *po = pkt_sk(sk); 3364 3365 switch (msg) { 3366 case NETDEV_UNREGISTER: 3367 if (po->mclist) 3368 packet_dev_mclist(dev, po->mclist, -1); 3369 /* fallthrough */ 3370 3371 case NETDEV_DOWN: 3372 if (dev->ifindex == po->ifindex) { 3373 spin_lock(&po->bind_lock); 3374 if (po->running) { 3375 __unregister_prot_hook(sk, false); 3376 sk->sk_err = ENETDOWN; 3377 if (!sock_flag(sk, SOCK_DEAD)) 3378 sk->sk_error_report(sk); 3379 } 3380 if (msg == NETDEV_UNREGISTER) { 3381 po->ifindex = -1; 3382 if (po->prot_hook.dev) 3383 dev_put(po->prot_hook.dev); 3384 po->prot_hook.dev = NULL; 3385 } 3386 spin_unlock(&po->bind_lock); 3387 } 3388 break; 3389 case NETDEV_UP: 3390 if (dev->ifindex == po->ifindex) { 3391 spin_lock(&po->bind_lock); 3392 if (po->num) 3393 register_prot_hook(sk); 3394 spin_unlock(&po->bind_lock); 3395 } 3396 break; 3397 } 3398 } 3399 rcu_read_unlock(); 3400 return NOTIFY_DONE; 3401 } 3402 3403 3404 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3405 unsigned long arg) 3406 { 3407 struct sock *sk = sock->sk; 3408 3409 switch (cmd) { 3410 case SIOCOUTQ: 3411 { 3412 int amount = sk_wmem_alloc_get(sk); 3413 3414 return put_user(amount, (int __user *)arg); 3415 } 3416 case SIOCINQ: 3417 { 3418 struct sk_buff *skb; 3419 int amount = 0; 3420 3421 spin_lock_bh(&sk->sk_receive_queue.lock); 3422 skb = skb_peek(&sk->sk_receive_queue); 3423 if (skb) 3424 amount = skb->len; 3425 spin_unlock_bh(&sk->sk_receive_queue.lock); 3426 return put_user(amount, (int __user *)arg); 3427 } 3428 case SIOCGSTAMP: 3429 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3430 case SIOCGSTAMPNS: 3431 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3432 3433 #ifdef CONFIG_INET 3434 case SIOCADDRT: 3435 case SIOCDELRT: 3436 case SIOCDARP: 3437 case SIOCGARP: 3438 case SIOCSARP: 3439 case SIOCGIFADDR: 3440 case SIOCSIFADDR: 3441 case SIOCGIFBRDADDR: 3442 case SIOCSIFBRDADDR: 3443 case SIOCGIFNETMASK: 3444 case SIOCSIFNETMASK: 3445 case SIOCGIFDSTADDR: 3446 case SIOCSIFDSTADDR: 3447 case SIOCSIFFLAGS: 3448 return inet_dgram_ops.ioctl(sock, cmd, arg); 3449 #endif 3450 3451 default: 3452 return -ENOIOCTLCMD; 3453 } 3454 return 0; 3455 } 3456 3457 static unsigned int packet_poll(struct file *file, struct socket *sock, 3458 poll_table *wait) 3459 { 3460 struct sock *sk = sock->sk; 3461 struct packet_sock *po = pkt_sk(sk); 3462 unsigned int mask = datagram_poll(file, sock, wait); 3463 3464 spin_lock_bh(&sk->sk_receive_queue.lock); 3465 if (po->rx_ring.pg_vec) { 3466 if (!packet_previous_rx_frame(po, &po->rx_ring, 3467 TP_STATUS_KERNEL)) 3468 mask |= POLLIN | POLLRDNORM; 3469 } 3470 spin_unlock_bh(&sk->sk_receive_queue.lock); 3471 spin_lock_bh(&sk->sk_write_queue.lock); 3472 if (po->tx_ring.pg_vec) { 3473 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3474 mask |= POLLOUT | POLLWRNORM; 3475 } 3476 spin_unlock_bh(&sk->sk_write_queue.lock); 3477 return mask; 3478 } 3479 3480 3481 /* Dirty? Well, I still did not learn better way to account 3482 * for user mmaps. 3483 */ 3484 3485 static void packet_mm_open(struct vm_area_struct *vma) 3486 { 3487 struct file *file = vma->vm_file; 3488 struct socket *sock = file->private_data; 3489 struct sock *sk = sock->sk; 3490 3491 if (sk) 3492 atomic_inc(&pkt_sk(sk)->mapped); 3493 } 3494 3495 static void packet_mm_close(struct vm_area_struct *vma) 3496 { 3497 struct file *file = vma->vm_file; 3498 struct socket *sock = file->private_data; 3499 struct sock *sk = sock->sk; 3500 3501 if (sk) 3502 atomic_dec(&pkt_sk(sk)->mapped); 3503 } 3504 3505 static const struct vm_operations_struct packet_mmap_ops = { 3506 .open = packet_mm_open, 3507 .close = packet_mm_close, 3508 }; 3509 3510 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3511 unsigned int len) 3512 { 3513 int i; 3514 3515 for (i = 0; i < len; i++) { 3516 if (likely(pg_vec[i].buffer)) { 3517 if (is_vmalloc_addr(pg_vec[i].buffer)) 3518 vfree(pg_vec[i].buffer); 3519 else 3520 free_pages((unsigned long)pg_vec[i].buffer, 3521 order); 3522 pg_vec[i].buffer = NULL; 3523 } 3524 } 3525 kfree(pg_vec); 3526 } 3527 3528 static char *alloc_one_pg_vec_page(unsigned long order) 3529 { 3530 char *buffer = NULL; 3531 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3532 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3533 3534 buffer = (char *) __get_free_pages(gfp_flags, order); 3535 3536 if (buffer) 3537 return buffer; 3538 3539 /* 3540 * __get_free_pages failed, fall back to vmalloc 3541 */ 3542 buffer = vzalloc((1 << order) * PAGE_SIZE); 3543 3544 if (buffer) 3545 return buffer; 3546 3547 /* 3548 * vmalloc failed, lets dig into swap here 3549 */ 3550 gfp_flags &= ~__GFP_NORETRY; 3551 buffer = (char *)__get_free_pages(gfp_flags, order); 3552 if (buffer) 3553 return buffer; 3554 3555 /* 3556 * complete and utter failure 3557 */ 3558 return NULL; 3559 } 3560 3561 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3562 { 3563 unsigned int block_nr = req->tp_block_nr; 3564 struct pgv *pg_vec; 3565 int i; 3566 3567 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3568 if (unlikely(!pg_vec)) 3569 goto out; 3570 3571 for (i = 0; i < block_nr; i++) { 3572 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3573 if (unlikely(!pg_vec[i].buffer)) 3574 goto out_free_pgvec; 3575 } 3576 3577 out: 3578 return pg_vec; 3579 3580 out_free_pgvec: 3581 free_pg_vec(pg_vec, order, block_nr); 3582 pg_vec = NULL; 3583 goto out; 3584 } 3585 3586 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3587 int closing, int tx_ring) 3588 { 3589 struct pgv *pg_vec = NULL; 3590 struct packet_sock *po = pkt_sk(sk); 3591 int was_running, order = 0; 3592 struct packet_ring_buffer *rb; 3593 struct sk_buff_head *rb_queue; 3594 __be16 num; 3595 int err = -EINVAL; 3596 /* Added to avoid minimal code churn */ 3597 struct tpacket_req *req = &req_u->req; 3598 3599 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3600 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3601 WARN(1, "Tx-ring is not supported.\n"); 3602 goto out; 3603 } 3604 3605 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3606 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3607 3608 err = -EBUSY; 3609 if (!closing) { 3610 if (atomic_read(&po->mapped)) 3611 goto out; 3612 if (atomic_read(&rb->pending)) 3613 goto out; 3614 } 3615 3616 if (req->tp_block_nr) { 3617 /* Sanity tests and some calculations */ 3618 err = -EBUSY; 3619 if (unlikely(rb->pg_vec)) 3620 goto out; 3621 3622 switch (po->tp_version) { 3623 case TPACKET_V1: 3624 po->tp_hdrlen = TPACKET_HDRLEN; 3625 break; 3626 case TPACKET_V2: 3627 po->tp_hdrlen = TPACKET2_HDRLEN; 3628 break; 3629 case TPACKET_V3: 3630 po->tp_hdrlen = TPACKET3_HDRLEN; 3631 break; 3632 } 3633 3634 err = -EINVAL; 3635 if (unlikely((int)req->tp_block_size <= 0)) 3636 goto out; 3637 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3638 goto out; 3639 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3640 po->tp_reserve)) 3641 goto out; 3642 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3643 goto out; 3644 3645 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3646 if (unlikely(rb->frames_per_block <= 0)) 3647 goto out; 3648 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3649 req->tp_frame_nr)) 3650 goto out; 3651 3652 err = -ENOMEM; 3653 order = get_order(req->tp_block_size); 3654 pg_vec = alloc_pg_vec(req, order); 3655 if (unlikely(!pg_vec)) 3656 goto out; 3657 switch (po->tp_version) { 3658 case TPACKET_V3: 3659 /* Transmit path is not supported. We checked 3660 * it above but just being paranoid 3661 */ 3662 if (!tx_ring) 3663 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3664 break; 3665 default: 3666 break; 3667 } 3668 } 3669 /* Done */ 3670 else { 3671 err = -EINVAL; 3672 if (unlikely(req->tp_frame_nr)) 3673 goto out; 3674 } 3675 3676 lock_sock(sk); 3677 3678 /* Detach socket from network */ 3679 spin_lock(&po->bind_lock); 3680 was_running = po->running; 3681 num = po->num; 3682 if (was_running) { 3683 po->num = 0; 3684 __unregister_prot_hook(sk, false); 3685 } 3686 spin_unlock(&po->bind_lock); 3687 3688 synchronize_net(); 3689 3690 err = -EBUSY; 3691 mutex_lock(&po->pg_vec_lock); 3692 if (closing || atomic_read(&po->mapped) == 0) { 3693 err = 0; 3694 spin_lock_bh(&rb_queue->lock); 3695 swap(rb->pg_vec, pg_vec); 3696 rb->frame_max = (req->tp_frame_nr - 1); 3697 rb->head = 0; 3698 rb->frame_size = req->tp_frame_size; 3699 spin_unlock_bh(&rb_queue->lock); 3700 3701 swap(rb->pg_vec_order, order); 3702 swap(rb->pg_vec_len, req->tp_block_nr); 3703 3704 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3705 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3706 tpacket_rcv : packet_rcv; 3707 skb_queue_purge(rb_queue); 3708 if (atomic_read(&po->mapped)) 3709 pr_err("packet_mmap: vma is busy: %d\n", 3710 atomic_read(&po->mapped)); 3711 } 3712 mutex_unlock(&po->pg_vec_lock); 3713 3714 spin_lock(&po->bind_lock); 3715 if (was_running) { 3716 po->num = num; 3717 register_prot_hook(sk); 3718 } 3719 spin_unlock(&po->bind_lock); 3720 if (closing && (po->tp_version > TPACKET_V2)) { 3721 /* Because we don't support block-based V3 on tx-ring */ 3722 if (!tx_ring) 3723 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3724 } 3725 release_sock(sk); 3726 3727 if (pg_vec) 3728 free_pg_vec(pg_vec, order, req->tp_block_nr); 3729 out: 3730 return err; 3731 } 3732 3733 static int packet_mmap(struct file *file, struct socket *sock, 3734 struct vm_area_struct *vma) 3735 { 3736 struct sock *sk = sock->sk; 3737 struct packet_sock *po = pkt_sk(sk); 3738 unsigned long size, expected_size; 3739 struct packet_ring_buffer *rb; 3740 unsigned long start; 3741 int err = -EINVAL; 3742 int i; 3743 3744 if (vma->vm_pgoff) 3745 return -EINVAL; 3746 3747 mutex_lock(&po->pg_vec_lock); 3748 3749 expected_size = 0; 3750 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3751 if (rb->pg_vec) { 3752 expected_size += rb->pg_vec_len 3753 * rb->pg_vec_pages 3754 * PAGE_SIZE; 3755 } 3756 } 3757 3758 if (expected_size == 0) 3759 goto out; 3760 3761 size = vma->vm_end - vma->vm_start; 3762 if (size != expected_size) 3763 goto out; 3764 3765 start = vma->vm_start; 3766 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3767 if (rb->pg_vec == NULL) 3768 continue; 3769 3770 for (i = 0; i < rb->pg_vec_len; i++) { 3771 struct page *page; 3772 void *kaddr = rb->pg_vec[i].buffer; 3773 int pg_num; 3774 3775 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3776 page = pgv_to_page(kaddr); 3777 err = vm_insert_page(vma, start, page); 3778 if (unlikely(err)) 3779 goto out; 3780 start += PAGE_SIZE; 3781 kaddr += PAGE_SIZE; 3782 } 3783 } 3784 } 3785 3786 atomic_inc(&po->mapped); 3787 vma->vm_ops = &packet_mmap_ops; 3788 err = 0; 3789 3790 out: 3791 mutex_unlock(&po->pg_vec_lock); 3792 return err; 3793 } 3794 3795 static const struct proto_ops packet_ops_spkt = { 3796 .family = PF_PACKET, 3797 .owner = THIS_MODULE, 3798 .release = packet_release, 3799 .bind = packet_bind_spkt, 3800 .connect = sock_no_connect, 3801 .socketpair = sock_no_socketpair, 3802 .accept = sock_no_accept, 3803 .getname = packet_getname_spkt, 3804 .poll = datagram_poll, 3805 .ioctl = packet_ioctl, 3806 .listen = sock_no_listen, 3807 .shutdown = sock_no_shutdown, 3808 .setsockopt = sock_no_setsockopt, 3809 .getsockopt = sock_no_getsockopt, 3810 .sendmsg = packet_sendmsg_spkt, 3811 .recvmsg = packet_recvmsg, 3812 .mmap = sock_no_mmap, 3813 .sendpage = sock_no_sendpage, 3814 }; 3815 3816 static const struct proto_ops packet_ops = { 3817 .family = PF_PACKET, 3818 .owner = THIS_MODULE, 3819 .release = packet_release, 3820 .bind = packet_bind, 3821 .connect = sock_no_connect, 3822 .socketpair = sock_no_socketpair, 3823 .accept = sock_no_accept, 3824 .getname = packet_getname, 3825 .poll = packet_poll, 3826 .ioctl = packet_ioctl, 3827 .listen = sock_no_listen, 3828 .shutdown = sock_no_shutdown, 3829 .setsockopt = packet_setsockopt, 3830 .getsockopt = packet_getsockopt, 3831 .sendmsg = packet_sendmsg, 3832 .recvmsg = packet_recvmsg, 3833 .mmap = packet_mmap, 3834 .sendpage = sock_no_sendpage, 3835 }; 3836 3837 static const struct net_proto_family packet_family_ops = { 3838 .family = PF_PACKET, 3839 .create = packet_create, 3840 .owner = THIS_MODULE, 3841 }; 3842 3843 static struct notifier_block packet_netdev_notifier = { 3844 .notifier_call = packet_notifier, 3845 }; 3846 3847 #ifdef CONFIG_PROC_FS 3848 3849 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3850 __acquires(RCU) 3851 { 3852 struct net *net = seq_file_net(seq); 3853 3854 rcu_read_lock(); 3855 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3856 } 3857 3858 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3859 { 3860 struct net *net = seq_file_net(seq); 3861 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3862 } 3863 3864 static void packet_seq_stop(struct seq_file *seq, void *v) 3865 __releases(RCU) 3866 { 3867 rcu_read_unlock(); 3868 } 3869 3870 static int packet_seq_show(struct seq_file *seq, void *v) 3871 { 3872 if (v == SEQ_START_TOKEN) 3873 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3874 else { 3875 struct sock *s = sk_entry(v); 3876 const struct packet_sock *po = pkt_sk(s); 3877 3878 seq_printf(seq, 3879 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3880 s, 3881 atomic_read(&s->sk_refcnt), 3882 s->sk_type, 3883 ntohs(po->num), 3884 po->ifindex, 3885 po->running, 3886 atomic_read(&s->sk_rmem_alloc), 3887 sock_i_uid(s), 3888 sock_i_ino(s)); 3889 } 3890 3891 return 0; 3892 } 3893 3894 static const struct seq_operations packet_seq_ops = { 3895 .start = packet_seq_start, 3896 .next = packet_seq_next, 3897 .stop = packet_seq_stop, 3898 .show = packet_seq_show, 3899 }; 3900 3901 static int packet_seq_open(struct inode *inode, struct file *file) 3902 { 3903 return seq_open_net(inode, file, &packet_seq_ops, 3904 sizeof(struct seq_net_private)); 3905 } 3906 3907 static const struct file_operations packet_seq_fops = { 3908 .owner = THIS_MODULE, 3909 .open = packet_seq_open, 3910 .read = seq_read, 3911 .llseek = seq_lseek, 3912 .release = seq_release_net, 3913 }; 3914 3915 #endif 3916 3917 static int __net_init packet_net_init(struct net *net) 3918 { 3919 spin_lock_init(&net->packet.sklist_lock); 3920 INIT_HLIST_HEAD(&net->packet.sklist); 3921 3922 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops)) 3923 return -ENOMEM; 3924 3925 return 0; 3926 } 3927 3928 static void __net_exit packet_net_exit(struct net *net) 3929 { 3930 proc_net_remove(net, "packet"); 3931 } 3932 3933 static struct pernet_operations packet_net_ops = { 3934 .init = packet_net_init, 3935 .exit = packet_net_exit, 3936 }; 3937 3938 3939 static void __exit packet_exit(void) 3940 { 3941 unregister_netdevice_notifier(&packet_netdev_notifier); 3942 unregister_pernet_subsys(&packet_net_ops); 3943 sock_unregister(PF_PACKET); 3944 proto_unregister(&packet_proto); 3945 } 3946 3947 static int __init packet_init(void) 3948 { 3949 int rc = proto_register(&packet_proto, 0); 3950 3951 if (rc != 0) 3952 goto out; 3953 3954 sock_register(&packet_family_ops); 3955 register_pernet_subsys(&packet_net_ops); 3956 register_netdevice_notifier(&packet_netdev_notifier); 3957 out: 3958 return rc; 3959 } 3960 3961 module_init(packet_init); 3962 module_exit(packet_exit); 3963 MODULE_LICENSE("GPL"); 3964 MODULE_ALIAS_NETPROTO(PF_PACKET); 3965