1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <asm/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 96 /* 97 Assumptions: 98 - if device has no dev->hard_header routine, it adds and removes ll header 99 inside itself. In this case ll header is invisible outside of device, 100 but higher levels still should reserve dev->hard_header_len. 101 Some devices are enough clever to reallocate skb, when header 102 will not fit to reserved space (tunnel), another ones are silly 103 (PPP). 104 - packet socket receives packets with pulled ll header, 105 so that SOCK_RAW should push it back. 106 107 On receive: 108 ----------- 109 110 Incoming, dev->hard_header!=NULL 111 mac_header -> ll header 112 data -> data 113 114 Outgoing, dev->hard_header!=NULL 115 mac_header -> ll header 116 data -> ll header 117 118 Incoming, dev->hard_header==NULL 119 mac_header -> UNKNOWN position. It is very likely, that it points to ll 120 header. PPP makes it, that is wrong, because introduce 121 assymetry between rx and tx paths. 122 data -> data 123 124 Outgoing, dev->hard_header==NULL 125 mac_header -> data. ll header is still not built! 126 data -> data 127 128 Resume 129 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 130 131 132 On transmit: 133 ------------ 134 135 dev->hard_header != NULL 136 mac_header -> ll header 137 data -> ll header 138 139 dev->hard_header == NULL (ll header is added by device, we cannot control it) 140 mac_header -> data 141 data -> data 142 143 We should set nh.raw on output to correct posistion, 144 packet classifier depends on it. 145 */ 146 147 /* Private packet socket structures. */ 148 149 struct packet_mclist { 150 struct packet_mclist *next; 151 int ifindex; 152 int count; 153 unsigned short type; 154 unsigned short alen; 155 unsigned char addr[MAX_ADDR_LEN]; 156 }; 157 /* identical to struct packet_mreq except it has 158 * a longer address field. 159 */ 160 struct packet_mreq_max { 161 int mr_ifindex; 162 unsigned short mr_type; 163 unsigned short mr_alen; 164 unsigned char mr_address[MAX_ADDR_LEN]; 165 }; 166 167 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 168 int closing, int tx_ring); 169 170 171 #define V3_ALIGNMENT (8) 172 173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 174 175 #define BLK_PLUS_PRIV(sz_of_priv) \ 176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 177 178 /* kbdq - kernel block descriptor queue */ 179 struct tpacket_kbdq_core { 180 struct pgv *pkbdq; 181 unsigned int feature_req_word; 182 unsigned int hdrlen; 183 unsigned char reset_pending_on_curr_blk; 184 unsigned char delete_blk_timer; 185 unsigned short kactive_blk_num; 186 unsigned short blk_sizeof_priv; 187 188 /* last_kactive_blk_num: 189 * trick to see if user-space has caught up 190 * in order to avoid refreshing timer when every single pkt arrives. 191 */ 192 unsigned short last_kactive_blk_num; 193 194 char *pkblk_start; 195 char *pkblk_end; 196 int kblk_size; 197 unsigned int knum_blocks; 198 uint64_t knxt_seq_num; 199 char *prev; 200 char *nxt_offset; 201 struct sk_buff *skb; 202 203 atomic_t blk_fill_in_prog; 204 205 /* Default is set to 8ms */ 206 #define DEFAULT_PRB_RETIRE_TOV (8) 207 208 unsigned short retire_blk_tov; 209 unsigned short version; 210 unsigned long tov_in_jiffies; 211 212 /* timer to retire an outstanding block */ 213 struct timer_list retire_blk_timer; 214 }; 215 216 #define PGV_FROM_VMALLOC 1 217 struct pgv { 218 char *buffer; 219 }; 220 221 struct packet_ring_buffer { 222 struct pgv *pg_vec; 223 unsigned int head; 224 unsigned int frames_per_block; 225 unsigned int frame_size; 226 unsigned int frame_max; 227 228 unsigned int pg_vec_order; 229 unsigned int pg_vec_pages; 230 unsigned int pg_vec_len; 231 232 struct tpacket_kbdq_core prb_bdqc; 233 atomic_t pending; 234 }; 235 236 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 237 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 238 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 239 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 240 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 241 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 242 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 243 244 struct packet_sock; 245 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 246 247 static void *packet_previous_frame(struct packet_sock *po, 248 struct packet_ring_buffer *rb, 249 int status); 250 static void packet_increment_head(struct packet_ring_buffer *buff); 251 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 252 struct tpacket_block_desc *); 253 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 254 struct packet_sock *); 255 static void prb_retire_current_block(struct tpacket_kbdq_core *, 256 struct packet_sock *, unsigned int status); 257 static int prb_queue_frozen(struct tpacket_kbdq_core *); 258 static void prb_open_block(struct tpacket_kbdq_core *, 259 struct tpacket_block_desc *); 260 static void prb_retire_rx_blk_timer_expired(unsigned long); 261 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 262 static void prb_init_blk_timer(struct packet_sock *, 263 struct tpacket_kbdq_core *, 264 void (*func) (unsigned long)); 265 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 266 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 267 struct tpacket3_hdr *); 268 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 269 struct tpacket3_hdr *); 270 static void packet_flush_mclist(struct sock *sk); 271 272 struct packet_fanout; 273 struct packet_sock { 274 /* struct sock has to be the first member of packet_sock */ 275 struct sock sk; 276 struct packet_fanout *fanout; 277 struct tpacket_stats stats; 278 union tpacket_stats_u stats_u; 279 struct packet_ring_buffer rx_ring; 280 struct packet_ring_buffer tx_ring; 281 int copy_thresh; 282 spinlock_t bind_lock; 283 struct mutex pg_vec_lock; 284 unsigned int running:1, /* prot_hook is attached*/ 285 auxdata:1, 286 origdev:1, 287 has_vnet_hdr:1; 288 int ifindex; /* bound device */ 289 __be16 num; 290 struct packet_mclist *mclist; 291 atomic_t mapped; 292 enum tpacket_versions tp_version; 293 unsigned int tp_hdrlen; 294 unsigned int tp_reserve; 295 unsigned int tp_loss:1; 296 unsigned int tp_tstamp; 297 struct packet_type prot_hook ____cacheline_aligned_in_smp; 298 }; 299 300 #define PACKET_FANOUT_MAX 256 301 302 struct packet_fanout { 303 #ifdef CONFIG_NET_NS 304 struct net *net; 305 #endif 306 unsigned int num_members; 307 u16 id; 308 u8 type; 309 u8 defrag; 310 atomic_t rr_cur; 311 struct list_head list; 312 struct sock *arr[PACKET_FANOUT_MAX]; 313 spinlock_t lock; 314 atomic_t sk_ref; 315 struct packet_type prot_hook ____cacheline_aligned_in_smp; 316 }; 317 318 struct packet_skb_cb { 319 unsigned int origlen; 320 union { 321 struct sockaddr_pkt pkt; 322 struct sockaddr_ll ll; 323 } sa; 324 }; 325 326 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 327 328 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 329 #define GET_PBLOCK_DESC(x, bid) \ 330 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 331 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 332 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 333 #define GET_NEXT_PRB_BLK_NUM(x) \ 334 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 335 ((x)->kactive_blk_num+1) : 0) 336 337 static struct packet_sock *pkt_sk(struct sock *sk) 338 { 339 return (struct packet_sock *)sk; 340 } 341 342 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 343 static void __fanout_link(struct sock *sk, struct packet_sock *po); 344 345 /* register_prot_hook must be invoked with the po->bind_lock held, 346 * or from a context in which asynchronous accesses to the packet 347 * socket is not possible (packet_create()). 348 */ 349 static void register_prot_hook(struct sock *sk) 350 { 351 struct packet_sock *po = pkt_sk(sk); 352 if (!po->running) { 353 if (po->fanout) 354 __fanout_link(sk, po); 355 else 356 dev_add_pack(&po->prot_hook); 357 sock_hold(sk); 358 po->running = 1; 359 } 360 } 361 362 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 363 * held. If the sync parameter is true, we will temporarily drop 364 * the po->bind_lock and do a synchronize_net to make sure no 365 * asynchronous packet processing paths still refer to the elements 366 * of po->prot_hook. If the sync parameter is false, it is the 367 * callers responsibility to take care of this. 368 */ 369 static void __unregister_prot_hook(struct sock *sk, bool sync) 370 { 371 struct packet_sock *po = pkt_sk(sk); 372 373 po->running = 0; 374 if (po->fanout) 375 __fanout_unlink(sk, po); 376 else 377 __dev_remove_pack(&po->prot_hook); 378 __sock_put(sk); 379 380 if (sync) { 381 spin_unlock(&po->bind_lock); 382 synchronize_net(); 383 spin_lock(&po->bind_lock); 384 } 385 } 386 387 static void unregister_prot_hook(struct sock *sk, bool sync) 388 { 389 struct packet_sock *po = pkt_sk(sk); 390 391 if (po->running) 392 __unregister_prot_hook(sk, sync); 393 } 394 395 static inline __pure struct page *pgv_to_page(void *addr) 396 { 397 if (is_vmalloc_addr(addr)) 398 return vmalloc_to_page(addr); 399 return virt_to_page(addr); 400 } 401 402 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 403 { 404 union { 405 struct tpacket_hdr *h1; 406 struct tpacket2_hdr *h2; 407 void *raw; 408 } h; 409 410 h.raw = frame; 411 switch (po->tp_version) { 412 case TPACKET_V1: 413 h.h1->tp_status = status; 414 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 415 break; 416 case TPACKET_V2: 417 h.h2->tp_status = status; 418 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 419 break; 420 case TPACKET_V3: 421 default: 422 WARN(1, "TPACKET version not supported.\n"); 423 BUG(); 424 } 425 426 smp_wmb(); 427 } 428 429 static int __packet_get_status(struct packet_sock *po, void *frame) 430 { 431 union { 432 struct tpacket_hdr *h1; 433 struct tpacket2_hdr *h2; 434 void *raw; 435 } h; 436 437 smp_rmb(); 438 439 h.raw = frame; 440 switch (po->tp_version) { 441 case TPACKET_V1: 442 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 443 return h.h1->tp_status; 444 case TPACKET_V2: 445 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 446 return h.h2->tp_status; 447 case TPACKET_V3: 448 default: 449 WARN(1, "TPACKET version not supported.\n"); 450 BUG(); 451 return 0; 452 } 453 } 454 455 static void *packet_lookup_frame(struct packet_sock *po, 456 struct packet_ring_buffer *rb, 457 unsigned int position, 458 int status) 459 { 460 unsigned int pg_vec_pos, frame_offset; 461 union { 462 struct tpacket_hdr *h1; 463 struct tpacket2_hdr *h2; 464 void *raw; 465 } h; 466 467 pg_vec_pos = position / rb->frames_per_block; 468 frame_offset = position % rb->frames_per_block; 469 470 h.raw = rb->pg_vec[pg_vec_pos].buffer + 471 (frame_offset * rb->frame_size); 472 473 if (status != __packet_get_status(po, h.raw)) 474 return NULL; 475 476 return h.raw; 477 } 478 479 static void *packet_current_frame(struct packet_sock *po, 480 struct packet_ring_buffer *rb, 481 int status) 482 { 483 return packet_lookup_frame(po, rb, rb->head, status); 484 } 485 486 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 487 { 488 del_timer_sync(&pkc->retire_blk_timer); 489 } 490 491 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 492 int tx_ring, 493 struct sk_buff_head *rb_queue) 494 { 495 struct tpacket_kbdq_core *pkc; 496 497 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 498 499 spin_lock(&rb_queue->lock); 500 pkc->delete_blk_timer = 1; 501 spin_unlock(&rb_queue->lock); 502 503 prb_del_retire_blk_timer(pkc); 504 } 505 506 static void prb_init_blk_timer(struct packet_sock *po, 507 struct tpacket_kbdq_core *pkc, 508 void (*func) (unsigned long)) 509 { 510 init_timer(&pkc->retire_blk_timer); 511 pkc->retire_blk_timer.data = (long)po; 512 pkc->retire_blk_timer.function = func; 513 pkc->retire_blk_timer.expires = jiffies; 514 } 515 516 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) 517 { 518 struct tpacket_kbdq_core *pkc; 519 520 if (tx_ring) 521 BUG(); 522 523 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; 524 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 525 } 526 527 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 528 int blk_size_in_bytes) 529 { 530 struct net_device *dev; 531 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 532 struct ethtool_cmd ecmd; 533 int err; 534 535 rtnl_lock(); 536 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 537 if (unlikely(!dev)) { 538 rtnl_unlock(); 539 return DEFAULT_PRB_RETIRE_TOV; 540 } 541 err = __ethtool_get_settings(dev, &ecmd); 542 rtnl_unlock(); 543 if (!err) { 544 switch (ecmd.speed) { 545 case SPEED_10000: 546 msec = 1; 547 div = 10000/1000; 548 break; 549 case SPEED_1000: 550 msec = 1; 551 div = 1000/1000; 552 break; 553 /* 554 * If the link speed is so slow you don't really 555 * need to worry about perf anyways 556 */ 557 case SPEED_100: 558 case SPEED_10: 559 default: 560 return DEFAULT_PRB_RETIRE_TOV; 561 } 562 } 563 564 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 565 566 if (div) 567 mbits /= div; 568 569 tmo = mbits * msec; 570 571 if (div) 572 return tmo+1; 573 return tmo; 574 } 575 576 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 577 union tpacket_req_u *req_u) 578 { 579 p1->feature_req_word = req_u->req3.tp_feature_req_word; 580 } 581 582 static void init_prb_bdqc(struct packet_sock *po, 583 struct packet_ring_buffer *rb, 584 struct pgv *pg_vec, 585 union tpacket_req_u *req_u, int tx_ring) 586 { 587 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; 588 struct tpacket_block_desc *pbd; 589 590 memset(p1, 0x0, sizeof(*p1)); 591 592 p1->knxt_seq_num = 1; 593 p1->pkbdq = pg_vec; 594 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 595 p1->pkblk_start = (char *)pg_vec[0].buffer; 596 p1->kblk_size = req_u->req3.tp_block_size; 597 p1->knum_blocks = req_u->req3.tp_block_nr; 598 p1->hdrlen = po->tp_hdrlen; 599 p1->version = po->tp_version; 600 p1->last_kactive_blk_num = 0; 601 po->stats_u.stats3.tp_freeze_q_cnt = 0; 602 if (req_u->req3.tp_retire_blk_tov) 603 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 604 else 605 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 606 req_u->req3.tp_block_size); 607 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 608 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 609 610 prb_init_ft_ops(p1, req_u); 611 prb_setup_retire_blk_timer(po, tx_ring); 612 prb_open_block(p1, pbd); 613 } 614 615 /* Do NOT update the last_blk_num first. 616 * Assumes sk_buff_head lock is held. 617 */ 618 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 619 { 620 mod_timer(&pkc->retire_blk_timer, 621 jiffies + pkc->tov_in_jiffies); 622 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 623 } 624 625 /* 626 * Timer logic: 627 * 1) We refresh the timer only when we open a block. 628 * By doing this we don't waste cycles refreshing the timer 629 * on packet-by-packet basis. 630 * 631 * With a 1MB block-size, on a 1Gbps line, it will take 632 * i) ~8 ms to fill a block + ii) memcpy etc. 633 * In this cut we are not accounting for the memcpy time. 634 * 635 * So, if the user sets the 'tmo' to 10ms then the timer 636 * will never fire while the block is still getting filled 637 * (which is what we want). However, the user could choose 638 * to close a block early and that's fine. 639 * 640 * But when the timer does fire, we check whether or not to refresh it. 641 * Since the tmo granularity is in msecs, it is not too expensive 642 * to refresh the timer, lets say every '8' msecs. 643 * Either the user can set the 'tmo' or we can derive it based on 644 * a) line-speed and b) block-size. 645 * prb_calc_retire_blk_tmo() calculates the tmo. 646 * 647 */ 648 static void prb_retire_rx_blk_timer_expired(unsigned long data) 649 { 650 struct packet_sock *po = (struct packet_sock *)data; 651 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; 652 unsigned int frozen; 653 struct tpacket_block_desc *pbd; 654 655 spin_lock(&po->sk.sk_receive_queue.lock); 656 657 frozen = prb_queue_frozen(pkc); 658 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 659 660 if (unlikely(pkc->delete_blk_timer)) 661 goto out; 662 663 /* We only need to plug the race when the block is partially filled. 664 * tpacket_rcv: 665 * lock(); increment BLOCK_NUM_PKTS; unlock() 666 * copy_bits() is in progress ... 667 * timer fires on other cpu: 668 * we can't retire the current block because copy_bits 669 * is in progress. 670 * 671 */ 672 if (BLOCK_NUM_PKTS(pbd)) { 673 while (atomic_read(&pkc->blk_fill_in_prog)) { 674 /* Waiting for skb_copy_bits to finish... */ 675 cpu_relax(); 676 } 677 } 678 679 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 680 if (!frozen) { 681 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 682 if (!prb_dispatch_next_block(pkc, po)) 683 goto refresh_timer; 684 else 685 goto out; 686 } else { 687 /* Case 1. Queue was frozen because user-space was 688 * lagging behind. 689 */ 690 if (prb_curr_blk_in_use(pkc, pbd)) { 691 /* 692 * Ok, user-space is still behind. 693 * So just refresh the timer. 694 */ 695 goto refresh_timer; 696 } else { 697 /* Case 2. queue was frozen,user-space caught up, 698 * now the link went idle && the timer fired. 699 * We don't have a block to close.So we open this 700 * block and restart the timer. 701 * opening a block thaws the queue,restarts timer 702 * Thawing/timer-refresh is a side effect. 703 */ 704 prb_open_block(pkc, pbd); 705 goto out; 706 } 707 } 708 } 709 710 refresh_timer: 711 _prb_refresh_rx_retire_blk_timer(pkc); 712 713 out: 714 spin_unlock(&po->sk.sk_receive_queue.lock); 715 } 716 717 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 718 struct tpacket_block_desc *pbd1, __u32 status) 719 { 720 /* Flush everything minus the block header */ 721 722 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 723 u8 *start, *end; 724 725 start = (u8 *)pbd1; 726 727 /* Skip the block header(we know header WILL fit in 4K) */ 728 start += PAGE_SIZE; 729 730 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 731 for (; start < end; start += PAGE_SIZE) 732 flush_dcache_page(pgv_to_page(start)); 733 734 smp_wmb(); 735 #endif 736 737 /* Now update the block status. */ 738 739 BLOCK_STATUS(pbd1) = status; 740 741 /* Flush the block header */ 742 743 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 744 start = (u8 *)pbd1; 745 flush_dcache_page(pgv_to_page(start)); 746 747 smp_wmb(); 748 #endif 749 } 750 751 /* 752 * Side effect: 753 * 754 * 1) flush the block 755 * 2) Increment active_blk_num 756 * 757 * Note:We DONT refresh the timer on purpose. 758 * Because almost always the next block will be opened. 759 */ 760 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 761 struct tpacket_block_desc *pbd1, 762 struct packet_sock *po, unsigned int stat) 763 { 764 __u32 status = TP_STATUS_USER | stat; 765 766 struct tpacket3_hdr *last_pkt; 767 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 768 769 if (po->stats.tp_drops) 770 status |= TP_STATUS_LOSING; 771 772 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 773 last_pkt->tp_next_offset = 0; 774 775 /* Get the ts of the last pkt */ 776 if (BLOCK_NUM_PKTS(pbd1)) { 777 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 778 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 779 } else { 780 /* Ok, we tmo'd - so get the current time */ 781 struct timespec ts; 782 getnstimeofday(&ts); 783 h1->ts_last_pkt.ts_sec = ts.tv_sec; 784 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 785 } 786 787 smp_wmb(); 788 789 /* Flush the block */ 790 prb_flush_block(pkc1, pbd1, status); 791 792 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 793 } 794 795 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 796 { 797 pkc->reset_pending_on_curr_blk = 0; 798 } 799 800 /* 801 * Side effect of opening a block: 802 * 803 * 1) prb_queue is thawed. 804 * 2) retire_blk_timer is refreshed. 805 * 806 */ 807 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 808 struct tpacket_block_desc *pbd1) 809 { 810 struct timespec ts; 811 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 812 813 smp_rmb(); 814 815 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { 816 817 /* We could have just memset this but we will lose the 818 * flexibility of making the priv area sticky 819 */ 820 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 821 BLOCK_NUM_PKTS(pbd1) = 0; 822 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 823 getnstimeofday(&ts); 824 h1->ts_first_pkt.ts_sec = ts.tv_sec; 825 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 826 pkc1->pkblk_start = (char *)pbd1; 827 pkc1->nxt_offset = (char *)(pkc1->pkblk_start + 828 BLK_PLUS_PRIV(pkc1->blk_sizeof_priv)); 829 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 830 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 831 pbd1->version = pkc1->version; 832 pkc1->prev = pkc1->nxt_offset; 833 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 834 prb_thaw_queue(pkc1); 835 _prb_refresh_rx_retire_blk_timer(pkc1); 836 837 smp_wmb(); 838 839 return; 840 } 841 842 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", 843 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); 844 dump_stack(); 845 BUG(); 846 } 847 848 /* 849 * Queue freeze logic: 850 * 1) Assume tp_block_nr = 8 blocks. 851 * 2) At time 't0', user opens Rx ring. 852 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 853 * 4) user-space is either sleeping or processing block '0'. 854 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 855 * it will close block-7,loop around and try to fill block '0'. 856 * call-flow: 857 * __packet_lookup_frame_in_block 858 * prb_retire_current_block() 859 * prb_dispatch_next_block() 860 * |->(BLOCK_STATUS == USER) evaluates to true 861 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 862 * 6) Now there are two cases: 863 * 6.1) Link goes idle right after the queue is frozen. 864 * But remember, the last open_block() refreshed the timer. 865 * When this timer expires,it will refresh itself so that we can 866 * re-open block-0 in near future. 867 * 6.2) Link is busy and keeps on receiving packets. This is a simple 868 * case and __packet_lookup_frame_in_block will check if block-0 869 * is free and can now be re-used. 870 */ 871 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 872 struct packet_sock *po) 873 { 874 pkc->reset_pending_on_curr_blk = 1; 875 po->stats_u.stats3.tp_freeze_q_cnt++; 876 } 877 878 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 879 880 /* 881 * If the next block is free then we will dispatch it 882 * and return a good offset. 883 * Else, we will freeze the queue. 884 * So, caller must check the return value. 885 */ 886 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 887 struct packet_sock *po) 888 { 889 struct tpacket_block_desc *pbd; 890 891 smp_rmb(); 892 893 /* 1. Get current block num */ 894 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 895 896 /* 2. If this block is currently in_use then freeze the queue */ 897 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 898 prb_freeze_queue(pkc, po); 899 return NULL; 900 } 901 902 /* 903 * 3. 904 * open this block and return the offset where the first packet 905 * needs to get stored. 906 */ 907 prb_open_block(pkc, pbd); 908 return (void *)pkc->nxt_offset; 909 } 910 911 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 912 struct packet_sock *po, unsigned int status) 913 { 914 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 915 916 /* retire/close the current block */ 917 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 918 /* 919 * Plug the case where copy_bits() is in progress on 920 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 921 * have space to copy the pkt in the current block and 922 * called prb_retire_current_block() 923 * 924 * We don't need to worry about the TMO case because 925 * the timer-handler already handled this case. 926 */ 927 if (!(status & TP_STATUS_BLK_TMO)) { 928 while (atomic_read(&pkc->blk_fill_in_prog)) { 929 /* Waiting for skb_copy_bits to finish... */ 930 cpu_relax(); 931 } 932 } 933 prb_close_block(pkc, pbd, po, status); 934 return; 935 } 936 937 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); 938 dump_stack(); 939 BUG(); 940 } 941 942 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 943 struct tpacket_block_desc *pbd) 944 { 945 return TP_STATUS_USER & BLOCK_STATUS(pbd); 946 } 947 948 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 949 { 950 return pkc->reset_pending_on_curr_blk; 951 } 952 953 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 954 { 955 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 956 atomic_dec(&pkc->blk_fill_in_prog); 957 } 958 959 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 960 struct tpacket3_hdr *ppd) 961 { 962 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); 963 } 964 965 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 966 struct tpacket3_hdr *ppd) 967 { 968 ppd->hv1.tp_rxhash = 0; 969 } 970 971 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 972 struct tpacket3_hdr *ppd) 973 { 974 if (vlan_tx_tag_present(pkc->skb)) { 975 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); 976 ppd->tp_status = TP_STATUS_VLAN_VALID; 977 } else { 978 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0; 979 } 980 } 981 982 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 983 struct tpacket3_hdr *ppd) 984 { 985 prb_fill_vlan_info(pkc, ppd); 986 987 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 988 prb_fill_rxhash(pkc, ppd); 989 else 990 prb_clear_rxhash(pkc, ppd); 991 } 992 993 static void prb_fill_curr_block(char *curr, 994 struct tpacket_kbdq_core *pkc, 995 struct tpacket_block_desc *pbd, 996 unsigned int len) 997 { 998 struct tpacket3_hdr *ppd; 999 1000 ppd = (struct tpacket3_hdr *)curr; 1001 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1002 pkc->prev = curr; 1003 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1004 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1005 BLOCK_NUM_PKTS(pbd) += 1; 1006 atomic_inc(&pkc->blk_fill_in_prog); 1007 prb_run_all_ft_ops(pkc, ppd); 1008 } 1009 1010 /* Assumes caller has the sk->rx_queue.lock */ 1011 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1012 struct sk_buff *skb, 1013 int status, 1014 unsigned int len 1015 ) 1016 { 1017 struct tpacket_kbdq_core *pkc; 1018 struct tpacket_block_desc *pbd; 1019 char *curr, *end; 1020 1021 pkc = GET_PBDQC_FROM_RB(((struct packet_ring_buffer *)&po->rx_ring)); 1022 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1023 1024 /* Queue is frozen when user space is lagging behind */ 1025 if (prb_queue_frozen(pkc)) { 1026 /* 1027 * Check if that last block which caused the queue to freeze, 1028 * is still in_use by user-space. 1029 */ 1030 if (prb_curr_blk_in_use(pkc, pbd)) { 1031 /* Can't record this packet */ 1032 return NULL; 1033 } else { 1034 /* 1035 * Ok, the block was released by user-space. 1036 * Now let's open that block. 1037 * opening a block also thaws the queue. 1038 * Thawing is a side effect. 1039 */ 1040 prb_open_block(pkc, pbd); 1041 } 1042 } 1043 1044 smp_mb(); 1045 curr = pkc->nxt_offset; 1046 pkc->skb = skb; 1047 end = (char *) ((char *)pbd + pkc->kblk_size); 1048 1049 /* first try the current block */ 1050 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1051 prb_fill_curr_block(curr, pkc, pbd, len); 1052 return (void *)curr; 1053 } 1054 1055 /* Ok, close the current block */ 1056 prb_retire_current_block(pkc, po, 0); 1057 1058 /* Now, try to dispatch the next block */ 1059 curr = (char *)prb_dispatch_next_block(pkc, po); 1060 if (curr) { 1061 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1062 prb_fill_curr_block(curr, pkc, pbd, len); 1063 return (void *)curr; 1064 } 1065 1066 /* 1067 * No free blocks are available.user_space hasn't caught up yet. 1068 * Queue was just frozen and now this packet will get dropped. 1069 */ 1070 return NULL; 1071 } 1072 1073 static void *packet_current_rx_frame(struct packet_sock *po, 1074 struct sk_buff *skb, 1075 int status, unsigned int len) 1076 { 1077 char *curr = NULL; 1078 switch (po->tp_version) { 1079 case TPACKET_V1: 1080 case TPACKET_V2: 1081 curr = packet_lookup_frame(po, &po->rx_ring, 1082 po->rx_ring.head, status); 1083 return curr; 1084 case TPACKET_V3: 1085 return __packet_lookup_frame_in_block(po, skb, status, len); 1086 default: 1087 WARN(1, "TPACKET version not supported\n"); 1088 BUG(); 1089 return 0; 1090 } 1091 } 1092 1093 static void *prb_lookup_block(struct packet_sock *po, 1094 struct packet_ring_buffer *rb, 1095 unsigned int previous, 1096 int status) 1097 { 1098 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1099 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous); 1100 1101 if (status != BLOCK_STATUS(pbd)) 1102 return NULL; 1103 return pbd; 1104 } 1105 1106 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1107 { 1108 unsigned int prev; 1109 if (rb->prb_bdqc.kactive_blk_num) 1110 prev = rb->prb_bdqc.kactive_blk_num-1; 1111 else 1112 prev = rb->prb_bdqc.knum_blocks-1; 1113 return prev; 1114 } 1115 1116 /* Assumes caller has held the rx_queue.lock */ 1117 static void *__prb_previous_block(struct packet_sock *po, 1118 struct packet_ring_buffer *rb, 1119 int status) 1120 { 1121 unsigned int previous = prb_previous_blk_num(rb); 1122 return prb_lookup_block(po, rb, previous, status); 1123 } 1124 1125 static void *packet_previous_rx_frame(struct packet_sock *po, 1126 struct packet_ring_buffer *rb, 1127 int status) 1128 { 1129 if (po->tp_version <= TPACKET_V2) 1130 return packet_previous_frame(po, rb, status); 1131 1132 return __prb_previous_block(po, rb, status); 1133 } 1134 1135 static void packet_increment_rx_head(struct packet_sock *po, 1136 struct packet_ring_buffer *rb) 1137 { 1138 switch (po->tp_version) { 1139 case TPACKET_V1: 1140 case TPACKET_V2: 1141 return packet_increment_head(rb); 1142 case TPACKET_V3: 1143 default: 1144 WARN(1, "TPACKET version not supported.\n"); 1145 BUG(); 1146 return; 1147 } 1148 } 1149 1150 static void *packet_previous_frame(struct packet_sock *po, 1151 struct packet_ring_buffer *rb, 1152 int status) 1153 { 1154 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1155 return packet_lookup_frame(po, rb, previous, status); 1156 } 1157 1158 static void packet_increment_head(struct packet_ring_buffer *buff) 1159 { 1160 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1161 } 1162 1163 static void packet_sock_destruct(struct sock *sk) 1164 { 1165 skb_queue_purge(&sk->sk_error_queue); 1166 1167 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1168 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1169 1170 if (!sock_flag(sk, SOCK_DEAD)) { 1171 pr_err("Attempt to release alive packet socket: %p\n", sk); 1172 return; 1173 } 1174 1175 sk_refcnt_debug_dec(sk); 1176 } 1177 1178 static int fanout_rr_next(struct packet_fanout *f, unsigned int num) 1179 { 1180 int x = atomic_read(&f->rr_cur) + 1; 1181 1182 if (x >= num) 1183 x = 0; 1184 1185 return x; 1186 } 1187 1188 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1189 { 1190 u32 idx, hash = skb->rxhash; 1191 1192 idx = ((u64)hash * num) >> 32; 1193 1194 return f->arr[idx]; 1195 } 1196 1197 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1198 { 1199 int cur, old; 1200 1201 cur = atomic_read(&f->rr_cur); 1202 while ((old = atomic_cmpxchg(&f->rr_cur, cur, 1203 fanout_rr_next(f, num))) != cur) 1204 cur = old; 1205 return f->arr[cur]; 1206 } 1207 1208 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) 1209 { 1210 unsigned int cpu = smp_processor_id(); 1211 1212 return f->arr[cpu % num]; 1213 } 1214 1215 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1216 struct packet_type *pt, struct net_device *orig_dev) 1217 { 1218 struct packet_fanout *f = pt->af_packet_priv; 1219 unsigned int num = f->num_members; 1220 struct packet_sock *po; 1221 struct sock *sk; 1222 1223 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1224 !num) { 1225 kfree_skb(skb); 1226 return 0; 1227 } 1228 1229 switch (f->type) { 1230 case PACKET_FANOUT_HASH: 1231 default: 1232 if (f->defrag) { 1233 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); 1234 if (!skb) 1235 return 0; 1236 } 1237 skb_get_rxhash(skb); 1238 sk = fanout_demux_hash(f, skb, num); 1239 break; 1240 case PACKET_FANOUT_LB: 1241 sk = fanout_demux_lb(f, skb, num); 1242 break; 1243 case PACKET_FANOUT_CPU: 1244 sk = fanout_demux_cpu(f, skb, num); 1245 break; 1246 } 1247 1248 po = pkt_sk(sk); 1249 1250 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1251 } 1252 1253 static DEFINE_MUTEX(fanout_mutex); 1254 static LIST_HEAD(fanout_list); 1255 1256 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1257 { 1258 struct packet_fanout *f = po->fanout; 1259 1260 spin_lock(&f->lock); 1261 f->arr[f->num_members] = sk; 1262 smp_wmb(); 1263 f->num_members++; 1264 spin_unlock(&f->lock); 1265 } 1266 1267 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1268 { 1269 struct packet_fanout *f = po->fanout; 1270 int i; 1271 1272 spin_lock(&f->lock); 1273 for (i = 0; i < f->num_members; i++) { 1274 if (f->arr[i] == sk) 1275 break; 1276 } 1277 BUG_ON(i >= f->num_members); 1278 f->arr[i] = f->arr[f->num_members - 1]; 1279 f->num_members--; 1280 spin_unlock(&f->lock); 1281 } 1282 1283 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1284 { 1285 struct packet_sock *po = pkt_sk(sk); 1286 struct packet_fanout *f, *match; 1287 u8 type = type_flags & 0xff; 1288 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; 1289 int err; 1290 1291 switch (type) { 1292 case PACKET_FANOUT_HASH: 1293 case PACKET_FANOUT_LB: 1294 case PACKET_FANOUT_CPU: 1295 break; 1296 default: 1297 return -EINVAL; 1298 } 1299 1300 if (!po->running) 1301 return -EINVAL; 1302 1303 if (po->fanout) 1304 return -EALREADY; 1305 1306 mutex_lock(&fanout_mutex); 1307 match = NULL; 1308 list_for_each_entry(f, &fanout_list, list) { 1309 if (f->id == id && 1310 read_pnet(&f->net) == sock_net(sk)) { 1311 match = f; 1312 break; 1313 } 1314 } 1315 err = -EINVAL; 1316 if (match && match->defrag != defrag) 1317 goto out; 1318 if (!match) { 1319 err = -ENOMEM; 1320 match = kzalloc(sizeof(*match), GFP_KERNEL); 1321 if (!match) 1322 goto out; 1323 write_pnet(&match->net, sock_net(sk)); 1324 match->id = id; 1325 match->type = type; 1326 match->defrag = defrag; 1327 atomic_set(&match->rr_cur, 0); 1328 INIT_LIST_HEAD(&match->list); 1329 spin_lock_init(&match->lock); 1330 atomic_set(&match->sk_ref, 0); 1331 match->prot_hook.type = po->prot_hook.type; 1332 match->prot_hook.dev = po->prot_hook.dev; 1333 match->prot_hook.func = packet_rcv_fanout; 1334 match->prot_hook.af_packet_priv = match; 1335 dev_add_pack(&match->prot_hook); 1336 list_add(&match->list, &fanout_list); 1337 } 1338 err = -EINVAL; 1339 if (match->type == type && 1340 match->prot_hook.type == po->prot_hook.type && 1341 match->prot_hook.dev == po->prot_hook.dev) { 1342 err = -ENOSPC; 1343 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1344 __dev_remove_pack(&po->prot_hook); 1345 po->fanout = match; 1346 atomic_inc(&match->sk_ref); 1347 __fanout_link(sk, po); 1348 err = 0; 1349 } 1350 } 1351 out: 1352 mutex_unlock(&fanout_mutex); 1353 return err; 1354 } 1355 1356 static void fanout_release(struct sock *sk) 1357 { 1358 struct packet_sock *po = pkt_sk(sk); 1359 struct packet_fanout *f; 1360 1361 f = po->fanout; 1362 if (!f) 1363 return; 1364 1365 po->fanout = NULL; 1366 1367 mutex_lock(&fanout_mutex); 1368 if (atomic_dec_and_test(&f->sk_ref)) { 1369 list_del(&f->list); 1370 dev_remove_pack(&f->prot_hook); 1371 kfree(f); 1372 } 1373 mutex_unlock(&fanout_mutex); 1374 } 1375 1376 static const struct proto_ops packet_ops; 1377 1378 static const struct proto_ops packet_ops_spkt; 1379 1380 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1381 struct packet_type *pt, struct net_device *orig_dev) 1382 { 1383 struct sock *sk; 1384 struct sockaddr_pkt *spkt; 1385 1386 /* 1387 * When we registered the protocol we saved the socket in the data 1388 * field for just this event. 1389 */ 1390 1391 sk = pt->af_packet_priv; 1392 1393 /* 1394 * Yank back the headers [hope the device set this 1395 * right or kerboom...] 1396 * 1397 * Incoming packets have ll header pulled, 1398 * push it back. 1399 * 1400 * For outgoing ones skb->data == skb_mac_header(skb) 1401 * so that this procedure is noop. 1402 */ 1403 1404 if (skb->pkt_type == PACKET_LOOPBACK) 1405 goto out; 1406 1407 if (!net_eq(dev_net(dev), sock_net(sk))) 1408 goto out; 1409 1410 skb = skb_share_check(skb, GFP_ATOMIC); 1411 if (skb == NULL) 1412 goto oom; 1413 1414 /* drop any routing info */ 1415 skb_dst_drop(skb); 1416 1417 /* drop conntrack reference */ 1418 nf_reset(skb); 1419 1420 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1421 1422 skb_push(skb, skb->data - skb_mac_header(skb)); 1423 1424 /* 1425 * The SOCK_PACKET socket receives _all_ frames. 1426 */ 1427 1428 spkt->spkt_family = dev->type; 1429 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1430 spkt->spkt_protocol = skb->protocol; 1431 1432 /* 1433 * Charge the memory to the socket. This is done specifically 1434 * to prevent sockets using all the memory up. 1435 */ 1436 1437 if (sock_queue_rcv_skb(sk, skb) == 0) 1438 return 0; 1439 1440 out: 1441 kfree_skb(skb); 1442 oom: 1443 return 0; 1444 } 1445 1446 1447 /* 1448 * Output a raw packet to a device layer. This bypasses all the other 1449 * protocol layers and you must therefore supply it with a complete frame 1450 */ 1451 1452 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 1453 struct msghdr *msg, size_t len) 1454 { 1455 struct sock *sk = sock->sk; 1456 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; 1457 struct sk_buff *skb = NULL; 1458 struct net_device *dev; 1459 __be16 proto = 0; 1460 int err; 1461 int extra_len = 0; 1462 1463 /* 1464 * Get and verify the address. 1465 */ 1466 1467 if (saddr) { 1468 if (msg->msg_namelen < sizeof(struct sockaddr)) 1469 return -EINVAL; 1470 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1471 proto = saddr->spkt_protocol; 1472 } else 1473 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1474 1475 /* 1476 * Find the device first to size check it 1477 */ 1478 1479 saddr->spkt_device[13] = 0; 1480 retry: 1481 rcu_read_lock(); 1482 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1483 err = -ENODEV; 1484 if (dev == NULL) 1485 goto out_unlock; 1486 1487 err = -ENETDOWN; 1488 if (!(dev->flags & IFF_UP)) 1489 goto out_unlock; 1490 1491 /* 1492 * You may not queue a frame bigger than the mtu. This is the lowest level 1493 * raw protocol and you must do your own fragmentation at this level. 1494 */ 1495 1496 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1497 if (!netif_supports_nofcs(dev)) { 1498 err = -EPROTONOSUPPORT; 1499 goto out_unlock; 1500 } 1501 extra_len = 4; /* We're doing our own CRC */ 1502 } 1503 1504 err = -EMSGSIZE; 1505 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1506 goto out_unlock; 1507 1508 if (!skb) { 1509 size_t reserved = LL_RESERVED_SPACE(dev); 1510 int tlen = dev->needed_tailroom; 1511 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1512 1513 rcu_read_unlock(); 1514 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1515 if (skb == NULL) 1516 return -ENOBUFS; 1517 /* FIXME: Save some space for broken drivers that write a hard 1518 * header at transmission time by themselves. PPP is the notable 1519 * one here. This should really be fixed at the driver level. 1520 */ 1521 skb_reserve(skb, reserved); 1522 skb_reset_network_header(skb); 1523 1524 /* Try to align data part correctly */ 1525 if (hhlen) { 1526 skb->data -= hhlen; 1527 skb->tail -= hhlen; 1528 if (len < hhlen) 1529 skb_reset_network_header(skb); 1530 } 1531 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 1532 if (err) 1533 goto out_free; 1534 goto retry; 1535 } 1536 1537 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1538 /* Earlier code assumed this would be a VLAN pkt, 1539 * double-check this now that we have the actual 1540 * packet in hand. 1541 */ 1542 struct ethhdr *ehdr; 1543 skb_reset_mac_header(skb); 1544 ehdr = eth_hdr(skb); 1545 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1546 err = -EMSGSIZE; 1547 goto out_unlock; 1548 } 1549 } 1550 1551 skb->protocol = proto; 1552 skb->dev = dev; 1553 skb->priority = sk->sk_priority; 1554 skb->mark = sk->sk_mark; 1555 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1556 if (err < 0) 1557 goto out_unlock; 1558 1559 if (unlikely(extra_len == 4)) 1560 skb->no_fcs = 1; 1561 1562 dev_queue_xmit(skb); 1563 rcu_read_unlock(); 1564 return len; 1565 1566 out_unlock: 1567 rcu_read_unlock(); 1568 out_free: 1569 kfree_skb(skb); 1570 return err; 1571 } 1572 1573 static unsigned int run_filter(const struct sk_buff *skb, 1574 const struct sock *sk, 1575 unsigned int res) 1576 { 1577 struct sk_filter *filter; 1578 1579 rcu_read_lock(); 1580 filter = rcu_dereference(sk->sk_filter); 1581 if (filter != NULL) 1582 res = SK_RUN_FILTER(filter, skb); 1583 rcu_read_unlock(); 1584 1585 return res; 1586 } 1587 1588 /* 1589 * This function makes lazy skb cloning in hope that most of packets 1590 * are discarded by BPF. 1591 * 1592 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1593 * and skb->cb are mangled. It works because (and until) packets 1594 * falling here are owned by current CPU. Output packets are cloned 1595 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1596 * sequencially, so that if we return skb to original state on exit, 1597 * we will not harm anyone. 1598 */ 1599 1600 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1601 struct packet_type *pt, struct net_device *orig_dev) 1602 { 1603 struct sock *sk; 1604 struct sockaddr_ll *sll; 1605 struct packet_sock *po; 1606 u8 *skb_head = skb->data; 1607 int skb_len = skb->len; 1608 unsigned int snaplen, res; 1609 1610 if (skb->pkt_type == PACKET_LOOPBACK) 1611 goto drop; 1612 1613 sk = pt->af_packet_priv; 1614 po = pkt_sk(sk); 1615 1616 if (!net_eq(dev_net(dev), sock_net(sk))) 1617 goto drop; 1618 1619 skb->dev = dev; 1620 1621 if (dev->header_ops) { 1622 /* The device has an explicit notion of ll header, 1623 * exported to higher levels. 1624 * 1625 * Otherwise, the device hides details of its frame 1626 * structure, so that corresponding packet head is 1627 * never delivered to user. 1628 */ 1629 if (sk->sk_type != SOCK_DGRAM) 1630 skb_push(skb, skb->data - skb_mac_header(skb)); 1631 else if (skb->pkt_type == PACKET_OUTGOING) { 1632 /* Special case: outgoing packets have ll header at head */ 1633 skb_pull(skb, skb_network_offset(skb)); 1634 } 1635 } 1636 1637 snaplen = skb->len; 1638 1639 res = run_filter(skb, sk, snaplen); 1640 if (!res) 1641 goto drop_n_restore; 1642 if (snaplen > res) 1643 snaplen = res; 1644 1645 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 1646 goto drop_n_acct; 1647 1648 if (skb_shared(skb)) { 1649 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 1650 if (nskb == NULL) 1651 goto drop_n_acct; 1652 1653 if (skb_head != skb->data) { 1654 skb->data = skb_head; 1655 skb->len = skb_len; 1656 } 1657 kfree_skb(skb); 1658 skb = nskb; 1659 } 1660 1661 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > 1662 sizeof(skb->cb)); 1663 1664 sll = &PACKET_SKB_CB(skb)->sa.ll; 1665 sll->sll_family = AF_PACKET; 1666 sll->sll_hatype = dev->type; 1667 sll->sll_protocol = skb->protocol; 1668 sll->sll_pkttype = skb->pkt_type; 1669 if (unlikely(po->origdev)) 1670 sll->sll_ifindex = orig_dev->ifindex; 1671 else 1672 sll->sll_ifindex = dev->ifindex; 1673 1674 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1675 1676 PACKET_SKB_CB(skb)->origlen = skb->len; 1677 1678 if (pskb_trim(skb, snaplen)) 1679 goto drop_n_acct; 1680 1681 skb_set_owner_r(skb, sk); 1682 skb->dev = NULL; 1683 skb_dst_drop(skb); 1684 1685 /* drop conntrack reference */ 1686 nf_reset(skb); 1687 1688 spin_lock(&sk->sk_receive_queue.lock); 1689 po->stats.tp_packets++; 1690 skb->dropcount = atomic_read(&sk->sk_drops); 1691 __skb_queue_tail(&sk->sk_receive_queue, skb); 1692 spin_unlock(&sk->sk_receive_queue.lock); 1693 sk->sk_data_ready(sk, skb->len); 1694 return 0; 1695 1696 drop_n_acct: 1697 spin_lock(&sk->sk_receive_queue.lock); 1698 po->stats.tp_drops++; 1699 atomic_inc(&sk->sk_drops); 1700 spin_unlock(&sk->sk_receive_queue.lock); 1701 1702 drop_n_restore: 1703 if (skb_head != skb->data && skb_shared(skb)) { 1704 skb->data = skb_head; 1705 skb->len = skb_len; 1706 } 1707 drop: 1708 consume_skb(skb); 1709 return 0; 1710 } 1711 1712 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 1713 struct packet_type *pt, struct net_device *orig_dev) 1714 { 1715 struct sock *sk; 1716 struct packet_sock *po; 1717 struct sockaddr_ll *sll; 1718 union { 1719 struct tpacket_hdr *h1; 1720 struct tpacket2_hdr *h2; 1721 struct tpacket3_hdr *h3; 1722 void *raw; 1723 } h; 1724 u8 *skb_head = skb->data; 1725 int skb_len = skb->len; 1726 unsigned int snaplen, res; 1727 unsigned long status = TP_STATUS_USER; 1728 unsigned short macoff, netoff, hdrlen; 1729 struct sk_buff *copy_skb = NULL; 1730 struct timeval tv; 1731 struct timespec ts; 1732 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 1733 1734 if (skb->pkt_type == PACKET_LOOPBACK) 1735 goto drop; 1736 1737 sk = pt->af_packet_priv; 1738 po = pkt_sk(sk); 1739 1740 if (!net_eq(dev_net(dev), sock_net(sk))) 1741 goto drop; 1742 1743 if (dev->header_ops) { 1744 if (sk->sk_type != SOCK_DGRAM) 1745 skb_push(skb, skb->data - skb_mac_header(skb)); 1746 else if (skb->pkt_type == PACKET_OUTGOING) { 1747 /* Special case: outgoing packets have ll header at head */ 1748 skb_pull(skb, skb_network_offset(skb)); 1749 } 1750 } 1751 1752 if (skb->ip_summed == CHECKSUM_PARTIAL) 1753 status |= TP_STATUS_CSUMNOTREADY; 1754 1755 snaplen = skb->len; 1756 1757 res = run_filter(skb, sk, snaplen); 1758 if (!res) 1759 goto drop_n_restore; 1760 if (snaplen > res) 1761 snaplen = res; 1762 1763 if (sk->sk_type == SOCK_DGRAM) { 1764 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 1765 po->tp_reserve; 1766 } else { 1767 unsigned maclen = skb_network_offset(skb); 1768 netoff = TPACKET_ALIGN(po->tp_hdrlen + 1769 (maclen < 16 ? 16 : maclen)) + 1770 po->tp_reserve; 1771 macoff = netoff - maclen; 1772 } 1773 if (po->tp_version <= TPACKET_V2) { 1774 if (macoff + snaplen > po->rx_ring.frame_size) { 1775 if (po->copy_thresh && 1776 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 1777 if (skb_shared(skb)) { 1778 copy_skb = skb_clone(skb, GFP_ATOMIC); 1779 } else { 1780 copy_skb = skb_get(skb); 1781 skb_head = skb->data; 1782 } 1783 if (copy_skb) 1784 skb_set_owner_r(copy_skb, sk); 1785 } 1786 snaplen = po->rx_ring.frame_size - macoff; 1787 if ((int)snaplen < 0) 1788 snaplen = 0; 1789 } 1790 } 1791 spin_lock(&sk->sk_receive_queue.lock); 1792 h.raw = packet_current_rx_frame(po, skb, 1793 TP_STATUS_KERNEL, (macoff+snaplen)); 1794 if (!h.raw) 1795 goto ring_is_full; 1796 if (po->tp_version <= TPACKET_V2) { 1797 packet_increment_rx_head(po, &po->rx_ring); 1798 /* 1799 * LOSING will be reported till you read the stats, 1800 * because it's COR - Clear On Read. 1801 * Anyways, moving it for V1/V2 only as V3 doesn't need this 1802 * at packet level. 1803 */ 1804 if (po->stats.tp_drops) 1805 status |= TP_STATUS_LOSING; 1806 } 1807 po->stats.tp_packets++; 1808 if (copy_skb) { 1809 status |= TP_STATUS_COPY; 1810 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 1811 } 1812 spin_unlock(&sk->sk_receive_queue.lock); 1813 1814 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 1815 1816 switch (po->tp_version) { 1817 case TPACKET_V1: 1818 h.h1->tp_len = skb->len; 1819 h.h1->tp_snaplen = snaplen; 1820 h.h1->tp_mac = macoff; 1821 h.h1->tp_net = netoff; 1822 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1823 && shhwtstamps->syststamp.tv64) 1824 tv = ktime_to_timeval(shhwtstamps->syststamp); 1825 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1826 && shhwtstamps->hwtstamp.tv64) 1827 tv = ktime_to_timeval(shhwtstamps->hwtstamp); 1828 else if (skb->tstamp.tv64) 1829 tv = ktime_to_timeval(skb->tstamp); 1830 else 1831 do_gettimeofday(&tv); 1832 h.h1->tp_sec = tv.tv_sec; 1833 h.h1->tp_usec = tv.tv_usec; 1834 hdrlen = sizeof(*h.h1); 1835 break; 1836 case TPACKET_V2: 1837 h.h2->tp_len = skb->len; 1838 h.h2->tp_snaplen = snaplen; 1839 h.h2->tp_mac = macoff; 1840 h.h2->tp_net = netoff; 1841 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1842 && shhwtstamps->syststamp.tv64) 1843 ts = ktime_to_timespec(shhwtstamps->syststamp); 1844 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1845 && shhwtstamps->hwtstamp.tv64) 1846 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1847 else if (skb->tstamp.tv64) 1848 ts = ktime_to_timespec(skb->tstamp); 1849 else 1850 getnstimeofday(&ts); 1851 h.h2->tp_sec = ts.tv_sec; 1852 h.h2->tp_nsec = ts.tv_nsec; 1853 if (vlan_tx_tag_present(skb)) { 1854 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); 1855 status |= TP_STATUS_VLAN_VALID; 1856 } else { 1857 h.h2->tp_vlan_tci = 0; 1858 } 1859 h.h2->tp_padding = 0; 1860 hdrlen = sizeof(*h.h2); 1861 break; 1862 case TPACKET_V3: 1863 /* tp_nxt_offset,vlan are already populated above. 1864 * So DONT clear those fields here 1865 */ 1866 h.h3->tp_status |= status; 1867 h.h3->tp_len = skb->len; 1868 h.h3->tp_snaplen = snaplen; 1869 h.h3->tp_mac = macoff; 1870 h.h3->tp_net = netoff; 1871 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) 1872 && shhwtstamps->syststamp.tv64) 1873 ts = ktime_to_timespec(shhwtstamps->syststamp); 1874 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) 1875 && shhwtstamps->hwtstamp.tv64) 1876 ts = ktime_to_timespec(shhwtstamps->hwtstamp); 1877 else if (skb->tstamp.tv64) 1878 ts = ktime_to_timespec(skb->tstamp); 1879 else 1880 getnstimeofday(&ts); 1881 h.h3->tp_sec = ts.tv_sec; 1882 h.h3->tp_nsec = ts.tv_nsec; 1883 hdrlen = sizeof(*h.h3); 1884 break; 1885 default: 1886 BUG(); 1887 } 1888 1889 sll = h.raw + TPACKET_ALIGN(hdrlen); 1890 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 1891 sll->sll_family = AF_PACKET; 1892 sll->sll_hatype = dev->type; 1893 sll->sll_protocol = skb->protocol; 1894 sll->sll_pkttype = skb->pkt_type; 1895 if (unlikely(po->origdev)) 1896 sll->sll_ifindex = orig_dev->ifindex; 1897 else 1898 sll->sll_ifindex = dev->ifindex; 1899 1900 smp_mb(); 1901 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 1902 { 1903 u8 *start, *end; 1904 1905 if (po->tp_version <= TPACKET_V2) { 1906 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw 1907 + macoff + snaplen); 1908 for (start = h.raw; start < end; start += PAGE_SIZE) 1909 flush_dcache_page(pgv_to_page(start)); 1910 } 1911 smp_wmb(); 1912 } 1913 #endif 1914 if (po->tp_version <= TPACKET_V2) 1915 __packet_set_status(po, h.raw, status); 1916 else 1917 prb_clear_blk_fill_status(&po->rx_ring); 1918 1919 sk->sk_data_ready(sk, 0); 1920 1921 drop_n_restore: 1922 if (skb_head != skb->data && skb_shared(skb)) { 1923 skb->data = skb_head; 1924 skb->len = skb_len; 1925 } 1926 drop: 1927 kfree_skb(skb); 1928 return 0; 1929 1930 ring_is_full: 1931 po->stats.tp_drops++; 1932 spin_unlock(&sk->sk_receive_queue.lock); 1933 1934 sk->sk_data_ready(sk, 0); 1935 kfree_skb(copy_skb); 1936 goto drop_n_restore; 1937 } 1938 1939 static void tpacket_destruct_skb(struct sk_buff *skb) 1940 { 1941 struct packet_sock *po = pkt_sk(skb->sk); 1942 void *ph; 1943 1944 if (likely(po->tx_ring.pg_vec)) { 1945 ph = skb_shinfo(skb)->destructor_arg; 1946 BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING); 1947 BUG_ON(atomic_read(&po->tx_ring.pending) == 0); 1948 atomic_dec(&po->tx_ring.pending); 1949 __packet_set_status(po, ph, TP_STATUS_AVAILABLE); 1950 } 1951 1952 sock_wfree(skb); 1953 } 1954 1955 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 1956 void *frame, struct net_device *dev, int size_max, 1957 __be16 proto, unsigned char *addr, int hlen) 1958 { 1959 union { 1960 struct tpacket_hdr *h1; 1961 struct tpacket2_hdr *h2; 1962 void *raw; 1963 } ph; 1964 int to_write, offset, len, tp_len, nr_frags, len_max; 1965 struct socket *sock = po->sk.sk_socket; 1966 struct page *page; 1967 void *data; 1968 int err; 1969 1970 ph.raw = frame; 1971 1972 skb->protocol = proto; 1973 skb->dev = dev; 1974 skb->priority = po->sk.sk_priority; 1975 skb->mark = po->sk.sk_mark; 1976 skb_shinfo(skb)->destructor_arg = ph.raw; 1977 1978 switch (po->tp_version) { 1979 case TPACKET_V2: 1980 tp_len = ph.h2->tp_len; 1981 break; 1982 default: 1983 tp_len = ph.h1->tp_len; 1984 break; 1985 } 1986 if (unlikely(tp_len > size_max)) { 1987 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 1988 return -EMSGSIZE; 1989 } 1990 1991 skb_reserve(skb, hlen); 1992 skb_reset_network_header(skb); 1993 1994 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 1995 to_write = tp_len; 1996 1997 if (sock->type == SOCK_DGRAM) { 1998 err = dev_hard_header(skb, dev, ntohs(proto), addr, 1999 NULL, tp_len); 2000 if (unlikely(err < 0)) 2001 return -EINVAL; 2002 } else if (dev->hard_header_len) { 2003 /* net device doesn't like empty head */ 2004 if (unlikely(tp_len <= dev->hard_header_len)) { 2005 pr_err("packet size is too short (%d < %d)\n", 2006 tp_len, dev->hard_header_len); 2007 return -EINVAL; 2008 } 2009 2010 skb_push(skb, dev->hard_header_len); 2011 err = skb_store_bits(skb, 0, data, 2012 dev->hard_header_len); 2013 if (unlikely(err)) 2014 return err; 2015 2016 data += dev->hard_header_len; 2017 to_write -= dev->hard_header_len; 2018 } 2019 2020 err = -EFAULT; 2021 offset = offset_in_page(data); 2022 len_max = PAGE_SIZE - offset; 2023 len = ((to_write > len_max) ? len_max : to_write); 2024 2025 skb->data_len = to_write; 2026 skb->len += to_write; 2027 skb->truesize += to_write; 2028 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2029 2030 while (likely(to_write)) { 2031 nr_frags = skb_shinfo(skb)->nr_frags; 2032 2033 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2034 pr_err("Packet exceed the number of skb frags(%lu)\n", 2035 MAX_SKB_FRAGS); 2036 return -EFAULT; 2037 } 2038 2039 page = pgv_to_page(data); 2040 data += len; 2041 flush_dcache_page(page); 2042 get_page(page); 2043 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2044 to_write -= len; 2045 offset = 0; 2046 len_max = PAGE_SIZE; 2047 len = ((to_write > len_max) ? len_max : to_write); 2048 } 2049 2050 return tp_len; 2051 } 2052 2053 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2054 { 2055 struct sk_buff *skb; 2056 struct net_device *dev; 2057 __be16 proto; 2058 bool need_rls_dev = false; 2059 int err, reserve = 0; 2060 void *ph; 2061 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2062 int tp_len, size_max; 2063 unsigned char *addr; 2064 int len_sum = 0; 2065 int status = 0; 2066 int hlen, tlen; 2067 2068 mutex_lock(&po->pg_vec_lock); 2069 2070 err = -EBUSY; 2071 if (saddr == NULL) { 2072 dev = po->prot_hook.dev; 2073 proto = po->num; 2074 addr = NULL; 2075 } else { 2076 err = -EINVAL; 2077 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2078 goto out; 2079 if (msg->msg_namelen < (saddr->sll_halen 2080 + offsetof(struct sockaddr_ll, 2081 sll_addr))) 2082 goto out; 2083 proto = saddr->sll_protocol; 2084 addr = saddr->sll_addr; 2085 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2086 need_rls_dev = true; 2087 } 2088 2089 err = -ENXIO; 2090 if (unlikely(dev == NULL)) 2091 goto out; 2092 2093 reserve = dev->hard_header_len; 2094 2095 err = -ENETDOWN; 2096 if (unlikely(!(dev->flags & IFF_UP))) 2097 goto out_put; 2098 2099 size_max = po->tx_ring.frame_size 2100 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2101 2102 if (size_max > dev->mtu + reserve) 2103 size_max = dev->mtu + reserve; 2104 2105 do { 2106 ph = packet_current_frame(po, &po->tx_ring, 2107 TP_STATUS_SEND_REQUEST); 2108 2109 if (unlikely(ph == NULL)) { 2110 schedule(); 2111 continue; 2112 } 2113 2114 status = TP_STATUS_SEND_REQUEST; 2115 hlen = LL_RESERVED_SPACE(dev); 2116 tlen = dev->needed_tailroom; 2117 skb = sock_alloc_send_skb(&po->sk, 2118 hlen + tlen + sizeof(struct sockaddr_ll), 2119 0, &err); 2120 2121 if (unlikely(skb == NULL)) 2122 goto out_status; 2123 2124 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2125 addr, hlen); 2126 2127 if (unlikely(tp_len < 0)) { 2128 if (po->tp_loss) { 2129 __packet_set_status(po, ph, 2130 TP_STATUS_AVAILABLE); 2131 packet_increment_head(&po->tx_ring); 2132 kfree_skb(skb); 2133 continue; 2134 } else { 2135 status = TP_STATUS_WRONG_FORMAT; 2136 err = tp_len; 2137 goto out_status; 2138 } 2139 } 2140 2141 skb->destructor = tpacket_destruct_skb; 2142 __packet_set_status(po, ph, TP_STATUS_SENDING); 2143 atomic_inc(&po->tx_ring.pending); 2144 2145 status = TP_STATUS_SEND_REQUEST; 2146 err = dev_queue_xmit(skb); 2147 if (unlikely(err > 0)) { 2148 err = net_xmit_errno(err); 2149 if (err && __packet_get_status(po, ph) == 2150 TP_STATUS_AVAILABLE) { 2151 /* skb was destructed already */ 2152 skb = NULL; 2153 goto out_status; 2154 } 2155 /* 2156 * skb was dropped but not destructed yet; 2157 * let's treat it like congestion or err < 0 2158 */ 2159 err = 0; 2160 } 2161 packet_increment_head(&po->tx_ring); 2162 len_sum += tp_len; 2163 } while (likely((ph != NULL) || 2164 ((!(msg->msg_flags & MSG_DONTWAIT)) && 2165 (atomic_read(&po->tx_ring.pending)))) 2166 ); 2167 2168 err = len_sum; 2169 goto out_put; 2170 2171 out_status: 2172 __packet_set_status(po, ph, status); 2173 kfree_skb(skb); 2174 out_put: 2175 if (need_rls_dev) 2176 dev_put(dev); 2177 out: 2178 mutex_unlock(&po->pg_vec_lock); 2179 return err; 2180 } 2181 2182 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2183 size_t reserve, size_t len, 2184 size_t linear, int noblock, 2185 int *err) 2186 { 2187 struct sk_buff *skb; 2188 2189 /* Under a page? Don't bother with paged skb. */ 2190 if (prepad + len < PAGE_SIZE || !linear) 2191 linear = len; 2192 2193 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2194 err); 2195 if (!skb) 2196 return NULL; 2197 2198 skb_reserve(skb, reserve); 2199 skb_put(skb, linear); 2200 skb->data_len = len - linear; 2201 skb->len += len - linear; 2202 2203 return skb; 2204 } 2205 2206 static int packet_snd(struct socket *sock, 2207 struct msghdr *msg, size_t len) 2208 { 2209 struct sock *sk = sock->sk; 2210 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; 2211 struct sk_buff *skb; 2212 struct net_device *dev; 2213 __be16 proto; 2214 bool need_rls_dev = false; 2215 unsigned char *addr; 2216 int err, reserve = 0; 2217 struct virtio_net_hdr vnet_hdr = { 0 }; 2218 int offset = 0; 2219 int vnet_hdr_len; 2220 struct packet_sock *po = pkt_sk(sk); 2221 unsigned short gso_type = 0; 2222 int hlen, tlen; 2223 int extra_len = 0; 2224 2225 /* 2226 * Get and verify the address. 2227 */ 2228 2229 if (saddr == NULL) { 2230 dev = po->prot_hook.dev; 2231 proto = po->num; 2232 addr = NULL; 2233 } else { 2234 err = -EINVAL; 2235 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2236 goto out; 2237 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2238 goto out; 2239 proto = saddr->sll_protocol; 2240 addr = saddr->sll_addr; 2241 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2242 need_rls_dev = true; 2243 } 2244 2245 err = -ENXIO; 2246 if (dev == NULL) 2247 goto out_unlock; 2248 if (sock->type == SOCK_RAW) 2249 reserve = dev->hard_header_len; 2250 2251 err = -ENETDOWN; 2252 if (!(dev->flags & IFF_UP)) 2253 goto out_unlock; 2254 2255 if (po->has_vnet_hdr) { 2256 vnet_hdr_len = sizeof(vnet_hdr); 2257 2258 err = -EINVAL; 2259 if (len < vnet_hdr_len) 2260 goto out_unlock; 2261 2262 len -= vnet_hdr_len; 2263 2264 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, 2265 vnet_hdr_len); 2266 if (err < 0) 2267 goto out_unlock; 2268 2269 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2270 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > 2271 vnet_hdr.hdr_len)) 2272 vnet_hdr.hdr_len = vnet_hdr.csum_start + 2273 vnet_hdr.csum_offset + 2; 2274 2275 err = -EINVAL; 2276 if (vnet_hdr.hdr_len > len) 2277 goto out_unlock; 2278 2279 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2280 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2281 case VIRTIO_NET_HDR_GSO_TCPV4: 2282 gso_type = SKB_GSO_TCPV4; 2283 break; 2284 case VIRTIO_NET_HDR_GSO_TCPV6: 2285 gso_type = SKB_GSO_TCPV6; 2286 break; 2287 case VIRTIO_NET_HDR_GSO_UDP: 2288 gso_type = SKB_GSO_UDP; 2289 break; 2290 default: 2291 goto out_unlock; 2292 } 2293 2294 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2295 gso_type |= SKB_GSO_TCP_ECN; 2296 2297 if (vnet_hdr.gso_size == 0) 2298 goto out_unlock; 2299 2300 } 2301 } 2302 2303 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2304 if (!netif_supports_nofcs(dev)) { 2305 err = -EPROTONOSUPPORT; 2306 goto out_unlock; 2307 } 2308 extra_len = 4; /* We're doing our own CRC */ 2309 } 2310 2311 err = -EMSGSIZE; 2312 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2313 goto out_unlock; 2314 2315 err = -ENOBUFS; 2316 hlen = LL_RESERVED_SPACE(dev); 2317 tlen = dev->needed_tailroom; 2318 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, 2319 msg->msg_flags & MSG_DONTWAIT, &err); 2320 if (skb == NULL) 2321 goto out_unlock; 2322 2323 skb_set_network_header(skb, reserve); 2324 2325 err = -EINVAL; 2326 if (sock->type == SOCK_DGRAM && 2327 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) 2328 goto out_free; 2329 2330 /* Returns -EFAULT on error */ 2331 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); 2332 if (err) 2333 goto out_free; 2334 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2335 if (err < 0) 2336 goto out_free; 2337 2338 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2339 /* Earlier code assumed this would be a VLAN pkt, 2340 * double-check this now that we have the actual 2341 * packet in hand. 2342 */ 2343 struct ethhdr *ehdr; 2344 skb_reset_mac_header(skb); 2345 ehdr = eth_hdr(skb); 2346 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2347 err = -EMSGSIZE; 2348 goto out_free; 2349 } 2350 } 2351 2352 skb->protocol = proto; 2353 skb->dev = dev; 2354 skb->priority = sk->sk_priority; 2355 skb->mark = sk->sk_mark; 2356 2357 if (po->has_vnet_hdr) { 2358 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2359 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, 2360 vnet_hdr.csum_offset)) { 2361 err = -EINVAL; 2362 goto out_free; 2363 } 2364 } 2365 2366 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; 2367 skb_shinfo(skb)->gso_type = gso_type; 2368 2369 /* Header must be checked, and gso_segs computed. */ 2370 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2371 skb_shinfo(skb)->gso_segs = 0; 2372 2373 len += vnet_hdr_len; 2374 } 2375 2376 if (unlikely(extra_len == 4)) 2377 skb->no_fcs = 1; 2378 2379 /* 2380 * Now send it 2381 */ 2382 2383 err = dev_queue_xmit(skb); 2384 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2385 goto out_unlock; 2386 2387 if (need_rls_dev) 2388 dev_put(dev); 2389 2390 return len; 2391 2392 out_free: 2393 kfree_skb(skb); 2394 out_unlock: 2395 if (dev && need_rls_dev) 2396 dev_put(dev); 2397 out: 2398 return err; 2399 } 2400 2401 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 2402 struct msghdr *msg, size_t len) 2403 { 2404 struct sock *sk = sock->sk; 2405 struct packet_sock *po = pkt_sk(sk); 2406 if (po->tx_ring.pg_vec) 2407 return tpacket_snd(po, msg); 2408 else 2409 return packet_snd(sock, msg, len); 2410 } 2411 2412 /* 2413 * Close a PACKET socket. This is fairly simple. We immediately go 2414 * to 'closed' state and remove our protocol entry in the device list. 2415 */ 2416 2417 static int packet_release(struct socket *sock) 2418 { 2419 struct sock *sk = sock->sk; 2420 struct packet_sock *po; 2421 struct net *net; 2422 union tpacket_req_u req_u; 2423 2424 if (!sk) 2425 return 0; 2426 2427 net = sock_net(sk); 2428 po = pkt_sk(sk); 2429 2430 spin_lock_bh(&net->packet.sklist_lock); 2431 sk_del_node_init_rcu(sk); 2432 sock_prot_inuse_add(net, sk->sk_prot, -1); 2433 spin_unlock_bh(&net->packet.sklist_lock); 2434 2435 spin_lock(&po->bind_lock); 2436 unregister_prot_hook(sk, false); 2437 if (po->prot_hook.dev) { 2438 dev_put(po->prot_hook.dev); 2439 po->prot_hook.dev = NULL; 2440 } 2441 spin_unlock(&po->bind_lock); 2442 2443 packet_flush_mclist(sk); 2444 2445 memset(&req_u, 0, sizeof(req_u)); 2446 2447 if (po->rx_ring.pg_vec) 2448 packet_set_ring(sk, &req_u, 1, 0); 2449 2450 if (po->tx_ring.pg_vec) 2451 packet_set_ring(sk, &req_u, 1, 1); 2452 2453 fanout_release(sk); 2454 2455 synchronize_net(); 2456 /* 2457 * Now the socket is dead. No more input will appear. 2458 */ 2459 sock_orphan(sk); 2460 sock->sk = NULL; 2461 2462 /* Purge queues */ 2463 2464 skb_queue_purge(&sk->sk_receive_queue); 2465 sk_refcnt_debug_release(sk); 2466 2467 sock_put(sk); 2468 return 0; 2469 } 2470 2471 /* 2472 * Attach a packet hook. 2473 */ 2474 2475 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) 2476 { 2477 struct packet_sock *po = pkt_sk(sk); 2478 2479 if (po->fanout) { 2480 if (dev) 2481 dev_put(dev); 2482 2483 return -EINVAL; 2484 } 2485 2486 lock_sock(sk); 2487 2488 spin_lock(&po->bind_lock); 2489 unregister_prot_hook(sk, true); 2490 po->num = protocol; 2491 po->prot_hook.type = protocol; 2492 if (po->prot_hook.dev) 2493 dev_put(po->prot_hook.dev); 2494 po->prot_hook.dev = dev; 2495 2496 po->ifindex = dev ? dev->ifindex : 0; 2497 2498 if (protocol == 0) 2499 goto out_unlock; 2500 2501 if (!dev || (dev->flags & IFF_UP)) { 2502 register_prot_hook(sk); 2503 } else { 2504 sk->sk_err = ENETDOWN; 2505 if (!sock_flag(sk, SOCK_DEAD)) 2506 sk->sk_error_report(sk); 2507 } 2508 2509 out_unlock: 2510 spin_unlock(&po->bind_lock); 2511 release_sock(sk); 2512 return 0; 2513 } 2514 2515 /* 2516 * Bind a packet socket to a device 2517 */ 2518 2519 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2520 int addr_len) 2521 { 2522 struct sock *sk = sock->sk; 2523 char name[15]; 2524 struct net_device *dev; 2525 int err = -ENODEV; 2526 2527 /* 2528 * Check legality 2529 */ 2530 2531 if (addr_len != sizeof(struct sockaddr)) 2532 return -EINVAL; 2533 strlcpy(name, uaddr->sa_data, sizeof(name)); 2534 2535 dev = dev_get_by_name(sock_net(sk), name); 2536 if (dev) 2537 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2538 return err; 2539 } 2540 2541 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2542 { 2543 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2544 struct sock *sk = sock->sk; 2545 struct net_device *dev = NULL; 2546 int err; 2547 2548 2549 /* 2550 * Check legality 2551 */ 2552 2553 if (addr_len < sizeof(struct sockaddr_ll)) 2554 return -EINVAL; 2555 if (sll->sll_family != AF_PACKET) 2556 return -EINVAL; 2557 2558 if (sll->sll_ifindex) { 2559 err = -ENODEV; 2560 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 2561 if (dev == NULL) 2562 goto out; 2563 } 2564 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 2565 2566 out: 2567 return err; 2568 } 2569 2570 static struct proto packet_proto = { 2571 .name = "PACKET", 2572 .owner = THIS_MODULE, 2573 .obj_size = sizeof(struct packet_sock), 2574 }; 2575 2576 /* 2577 * Create a packet of type SOCK_PACKET. 2578 */ 2579 2580 static int packet_create(struct net *net, struct socket *sock, int protocol, 2581 int kern) 2582 { 2583 struct sock *sk; 2584 struct packet_sock *po; 2585 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 2586 int err; 2587 2588 if (!capable(CAP_NET_RAW)) 2589 return -EPERM; 2590 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 2591 sock->type != SOCK_PACKET) 2592 return -ESOCKTNOSUPPORT; 2593 2594 sock->state = SS_UNCONNECTED; 2595 2596 err = -ENOBUFS; 2597 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); 2598 if (sk == NULL) 2599 goto out; 2600 2601 sock->ops = &packet_ops; 2602 if (sock->type == SOCK_PACKET) 2603 sock->ops = &packet_ops_spkt; 2604 2605 sock_init_data(sock, sk); 2606 2607 po = pkt_sk(sk); 2608 sk->sk_family = PF_PACKET; 2609 po->num = proto; 2610 2611 sk->sk_destruct = packet_sock_destruct; 2612 sk_refcnt_debug_inc(sk); 2613 2614 /* 2615 * Attach a protocol block 2616 */ 2617 2618 spin_lock_init(&po->bind_lock); 2619 mutex_init(&po->pg_vec_lock); 2620 po->prot_hook.func = packet_rcv; 2621 2622 if (sock->type == SOCK_PACKET) 2623 po->prot_hook.func = packet_rcv_spkt; 2624 2625 po->prot_hook.af_packet_priv = sk; 2626 2627 if (proto) { 2628 po->prot_hook.type = proto; 2629 register_prot_hook(sk); 2630 } 2631 2632 spin_lock_bh(&net->packet.sklist_lock); 2633 sk_add_node_rcu(sk, &net->packet.sklist); 2634 sock_prot_inuse_add(net, &packet_proto, 1); 2635 spin_unlock_bh(&net->packet.sklist_lock); 2636 2637 return 0; 2638 out: 2639 return err; 2640 } 2641 2642 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) 2643 { 2644 struct sock_exterr_skb *serr; 2645 struct sk_buff *skb, *skb2; 2646 int copied, err; 2647 2648 err = -EAGAIN; 2649 skb = skb_dequeue(&sk->sk_error_queue); 2650 if (skb == NULL) 2651 goto out; 2652 2653 copied = skb->len; 2654 if (copied > len) { 2655 msg->msg_flags |= MSG_TRUNC; 2656 copied = len; 2657 } 2658 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2659 if (err) 2660 goto out_free_skb; 2661 2662 sock_recv_timestamp(msg, sk, skb); 2663 2664 serr = SKB_EXT_ERR(skb); 2665 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, 2666 sizeof(serr->ee), &serr->ee); 2667 2668 msg->msg_flags |= MSG_ERRQUEUE; 2669 err = copied; 2670 2671 /* Reset and regenerate socket error */ 2672 spin_lock_bh(&sk->sk_error_queue.lock); 2673 sk->sk_err = 0; 2674 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 2675 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 2676 spin_unlock_bh(&sk->sk_error_queue.lock); 2677 sk->sk_error_report(sk); 2678 } else 2679 spin_unlock_bh(&sk->sk_error_queue.lock); 2680 2681 out_free_skb: 2682 kfree_skb(skb); 2683 out: 2684 return err; 2685 } 2686 2687 /* 2688 * Pull a packet from our receive queue and hand it to the user. 2689 * If necessary we block. 2690 */ 2691 2692 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 2693 struct msghdr *msg, size_t len, int flags) 2694 { 2695 struct sock *sk = sock->sk; 2696 struct sk_buff *skb; 2697 int copied, err; 2698 struct sockaddr_ll *sll; 2699 int vnet_hdr_len = 0; 2700 2701 err = -EINVAL; 2702 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 2703 goto out; 2704 2705 #if 0 2706 /* What error should we return now? EUNATTACH? */ 2707 if (pkt_sk(sk)->ifindex < 0) 2708 return -ENODEV; 2709 #endif 2710 2711 if (flags & MSG_ERRQUEUE) { 2712 err = packet_recv_error(sk, msg, len); 2713 goto out; 2714 } 2715 2716 /* 2717 * Call the generic datagram receiver. This handles all sorts 2718 * of horrible races and re-entrancy so we can forget about it 2719 * in the protocol layers. 2720 * 2721 * Now it will return ENETDOWN, if device have just gone down, 2722 * but then it will block. 2723 */ 2724 2725 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 2726 2727 /* 2728 * An error occurred so return it. Because skb_recv_datagram() 2729 * handles the blocking we don't see and worry about blocking 2730 * retries. 2731 */ 2732 2733 if (skb == NULL) 2734 goto out; 2735 2736 if (pkt_sk(sk)->has_vnet_hdr) { 2737 struct virtio_net_hdr vnet_hdr = { 0 }; 2738 2739 err = -EINVAL; 2740 vnet_hdr_len = sizeof(vnet_hdr); 2741 if (len < vnet_hdr_len) 2742 goto out_free; 2743 2744 len -= vnet_hdr_len; 2745 2746 if (skb_is_gso(skb)) { 2747 struct skb_shared_info *sinfo = skb_shinfo(skb); 2748 2749 /* This is a hint as to how much should be linear. */ 2750 vnet_hdr.hdr_len = skb_headlen(skb); 2751 vnet_hdr.gso_size = sinfo->gso_size; 2752 if (sinfo->gso_type & SKB_GSO_TCPV4) 2753 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 2754 else if (sinfo->gso_type & SKB_GSO_TCPV6) 2755 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 2756 else if (sinfo->gso_type & SKB_GSO_UDP) 2757 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 2758 else if (sinfo->gso_type & SKB_GSO_FCOE) 2759 goto out_free; 2760 else 2761 BUG(); 2762 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 2763 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 2764 } else 2765 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 2766 2767 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2768 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 2769 vnet_hdr.csum_start = skb_checksum_start_offset(skb); 2770 vnet_hdr.csum_offset = skb->csum_offset; 2771 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 2772 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 2773 } /* else everything is zero */ 2774 2775 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, 2776 vnet_hdr_len); 2777 if (err < 0) 2778 goto out_free; 2779 } 2780 2781 /* 2782 * If the address length field is there to be filled in, we fill 2783 * it in now. 2784 */ 2785 2786 sll = &PACKET_SKB_CB(skb)->sa.ll; 2787 if (sock->type == SOCK_PACKET) 2788 msg->msg_namelen = sizeof(struct sockaddr_pkt); 2789 else 2790 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 2791 2792 /* 2793 * You lose any data beyond the buffer you gave. If it worries a 2794 * user program they can ask the device for its MTU anyway. 2795 */ 2796 2797 copied = skb->len; 2798 if (copied > len) { 2799 copied = len; 2800 msg->msg_flags |= MSG_TRUNC; 2801 } 2802 2803 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 2804 if (err) 2805 goto out_free; 2806 2807 sock_recv_ts_and_drops(msg, sk, skb); 2808 2809 if (msg->msg_name) 2810 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 2811 msg->msg_namelen); 2812 2813 if (pkt_sk(sk)->auxdata) { 2814 struct tpacket_auxdata aux; 2815 2816 aux.tp_status = TP_STATUS_USER; 2817 if (skb->ip_summed == CHECKSUM_PARTIAL) 2818 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 2819 aux.tp_len = PACKET_SKB_CB(skb)->origlen; 2820 aux.tp_snaplen = skb->len; 2821 aux.tp_mac = 0; 2822 aux.tp_net = skb_network_offset(skb); 2823 if (vlan_tx_tag_present(skb)) { 2824 aux.tp_vlan_tci = vlan_tx_tag_get(skb); 2825 aux.tp_status |= TP_STATUS_VLAN_VALID; 2826 } else { 2827 aux.tp_vlan_tci = 0; 2828 } 2829 aux.tp_padding = 0; 2830 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 2831 } 2832 2833 /* 2834 * Free or return the buffer as appropriate. Again this 2835 * hides all the races and re-entrancy issues from us. 2836 */ 2837 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 2838 2839 out_free: 2840 skb_free_datagram(sk, skb); 2841 out: 2842 return err; 2843 } 2844 2845 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 2846 int *uaddr_len, int peer) 2847 { 2848 struct net_device *dev; 2849 struct sock *sk = sock->sk; 2850 2851 if (peer) 2852 return -EOPNOTSUPP; 2853 2854 uaddr->sa_family = AF_PACKET; 2855 rcu_read_lock(); 2856 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 2857 if (dev) 2858 strncpy(uaddr->sa_data, dev->name, 14); 2859 else 2860 memset(uaddr->sa_data, 0, 14); 2861 rcu_read_unlock(); 2862 *uaddr_len = sizeof(*uaddr); 2863 2864 return 0; 2865 } 2866 2867 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 2868 int *uaddr_len, int peer) 2869 { 2870 struct net_device *dev; 2871 struct sock *sk = sock->sk; 2872 struct packet_sock *po = pkt_sk(sk); 2873 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 2874 2875 if (peer) 2876 return -EOPNOTSUPP; 2877 2878 sll->sll_family = AF_PACKET; 2879 sll->sll_ifindex = po->ifindex; 2880 sll->sll_protocol = po->num; 2881 sll->sll_pkttype = 0; 2882 rcu_read_lock(); 2883 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 2884 if (dev) { 2885 sll->sll_hatype = dev->type; 2886 sll->sll_halen = dev->addr_len; 2887 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 2888 } else { 2889 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 2890 sll->sll_halen = 0; 2891 } 2892 rcu_read_unlock(); 2893 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 2894 2895 return 0; 2896 } 2897 2898 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 2899 int what) 2900 { 2901 switch (i->type) { 2902 case PACKET_MR_MULTICAST: 2903 if (i->alen != dev->addr_len) 2904 return -EINVAL; 2905 if (what > 0) 2906 return dev_mc_add(dev, i->addr); 2907 else 2908 return dev_mc_del(dev, i->addr); 2909 break; 2910 case PACKET_MR_PROMISC: 2911 return dev_set_promiscuity(dev, what); 2912 break; 2913 case PACKET_MR_ALLMULTI: 2914 return dev_set_allmulti(dev, what); 2915 break; 2916 case PACKET_MR_UNICAST: 2917 if (i->alen != dev->addr_len) 2918 return -EINVAL; 2919 if (what > 0) 2920 return dev_uc_add(dev, i->addr); 2921 else 2922 return dev_uc_del(dev, i->addr); 2923 break; 2924 default: 2925 break; 2926 } 2927 return 0; 2928 } 2929 2930 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 2931 { 2932 for ( ; i; i = i->next) { 2933 if (i->ifindex == dev->ifindex) 2934 packet_dev_mc(dev, i, what); 2935 } 2936 } 2937 2938 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 2939 { 2940 struct packet_sock *po = pkt_sk(sk); 2941 struct packet_mclist *ml, *i; 2942 struct net_device *dev; 2943 int err; 2944 2945 rtnl_lock(); 2946 2947 err = -ENODEV; 2948 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 2949 if (!dev) 2950 goto done; 2951 2952 err = -EINVAL; 2953 if (mreq->mr_alen > dev->addr_len) 2954 goto done; 2955 2956 err = -ENOBUFS; 2957 i = kmalloc(sizeof(*i), GFP_KERNEL); 2958 if (i == NULL) 2959 goto done; 2960 2961 err = 0; 2962 for (ml = po->mclist; ml; ml = ml->next) { 2963 if (ml->ifindex == mreq->mr_ifindex && 2964 ml->type == mreq->mr_type && 2965 ml->alen == mreq->mr_alen && 2966 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 2967 ml->count++; 2968 /* Free the new element ... */ 2969 kfree(i); 2970 goto done; 2971 } 2972 } 2973 2974 i->type = mreq->mr_type; 2975 i->ifindex = mreq->mr_ifindex; 2976 i->alen = mreq->mr_alen; 2977 memcpy(i->addr, mreq->mr_address, i->alen); 2978 i->count = 1; 2979 i->next = po->mclist; 2980 po->mclist = i; 2981 err = packet_dev_mc(dev, i, 1); 2982 if (err) { 2983 po->mclist = i->next; 2984 kfree(i); 2985 } 2986 2987 done: 2988 rtnl_unlock(); 2989 return err; 2990 } 2991 2992 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 2993 { 2994 struct packet_mclist *ml, **mlp; 2995 2996 rtnl_lock(); 2997 2998 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 2999 if (ml->ifindex == mreq->mr_ifindex && 3000 ml->type == mreq->mr_type && 3001 ml->alen == mreq->mr_alen && 3002 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3003 if (--ml->count == 0) { 3004 struct net_device *dev; 3005 *mlp = ml->next; 3006 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3007 if (dev) 3008 packet_dev_mc(dev, ml, -1); 3009 kfree(ml); 3010 } 3011 rtnl_unlock(); 3012 return 0; 3013 } 3014 } 3015 rtnl_unlock(); 3016 return -EADDRNOTAVAIL; 3017 } 3018 3019 static void packet_flush_mclist(struct sock *sk) 3020 { 3021 struct packet_sock *po = pkt_sk(sk); 3022 struct packet_mclist *ml; 3023 3024 if (!po->mclist) 3025 return; 3026 3027 rtnl_lock(); 3028 while ((ml = po->mclist) != NULL) { 3029 struct net_device *dev; 3030 3031 po->mclist = ml->next; 3032 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3033 if (dev != NULL) 3034 packet_dev_mc(dev, ml, -1); 3035 kfree(ml); 3036 } 3037 rtnl_unlock(); 3038 } 3039 3040 static int 3041 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3042 { 3043 struct sock *sk = sock->sk; 3044 struct packet_sock *po = pkt_sk(sk); 3045 int ret; 3046 3047 if (level != SOL_PACKET) 3048 return -ENOPROTOOPT; 3049 3050 switch (optname) { 3051 case PACKET_ADD_MEMBERSHIP: 3052 case PACKET_DROP_MEMBERSHIP: 3053 { 3054 struct packet_mreq_max mreq; 3055 int len = optlen; 3056 memset(&mreq, 0, sizeof(mreq)); 3057 if (len < sizeof(struct packet_mreq)) 3058 return -EINVAL; 3059 if (len > sizeof(mreq)) 3060 len = sizeof(mreq); 3061 if (copy_from_user(&mreq, optval, len)) 3062 return -EFAULT; 3063 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3064 return -EINVAL; 3065 if (optname == PACKET_ADD_MEMBERSHIP) 3066 ret = packet_mc_add(sk, &mreq); 3067 else 3068 ret = packet_mc_drop(sk, &mreq); 3069 return ret; 3070 } 3071 3072 case PACKET_RX_RING: 3073 case PACKET_TX_RING: 3074 { 3075 union tpacket_req_u req_u; 3076 int len; 3077 3078 switch (po->tp_version) { 3079 case TPACKET_V1: 3080 case TPACKET_V2: 3081 len = sizeof(req_u.req); 3082 break; 3083 case TPACKET_V3: 3084 default: 3085 len = sizeof(req_u.req3); 3086 break; 3087 } 3088 if (optlen < len) 3089 return -EINVAL; 3090 if (pkt_sk(sk)->has_vnet_hdr) 3091 return -EINVAL; 3092 if (copy_from_user(&req_u.req, optval, len)) 3093 return -EFAULT; 3094 return packet_set_ring(sk, &req_u, 0, 3095 optname == PACKET_TX_RING); 3096 } 3097 case PACKET_COPY_THRESH: 3098 { 3099 int val; 3100 3101 if (optlen != sizeof(val)) 3102 return -EINVAL; 3103 if (copy_from_user(&val, optval, sizeof(val))) 3104 return -EFAULT; 3105 3106 pkt_sk(sk)->copy_thresh = val; 3107 return 0; 3108 } 3109 case PACKET_VERSION: 3110 { 3111 int val; 3112 3113 if (optlen != sizeof(val)) 3114 return -EINVAL; 3115 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3116 return -EBUSY; 3117 if (copy_from_user(&val, optval, sizeof(val))) 3118 return -EFAULT; 3119 switch (val) { 3120 case TPACKET_V1: 3121 case TPACKET_V2: 3122 case TPACKET_V3: 3123 po->tp_version = val; 3124 return 0; 3125 default: 3126 return -EINVAL; 3127 } 3128 } 3129 case PACKET_RESERVE: 3130 { 3131 unsigned int val; 3132 3133 if (optlen != sizeof(val)) 3134 return -EINVAL; 3135 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3136 return -EBUSY; 3137 if (copy_from_user(&val, optval, sizeof(val))) 3138 return -EFAULT; 3139 po->tp_reserve = val; 3140 return 0; 3141 } 3142 case PACKET_LOSS: 3143 { 3144 unsigned int val; 3145 3146 if (optlen != sizeof(val)) 3147 return -EINVAL; 3148 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3149 return -EBUSY; 3150 if (copy_from_user(&val, optval, sizeof(val))) 3151 return -EFAULT; 3152 po->tp_loss = !!val; 3153 return 0; 3154 } 3155 case PACKET_AUXDATA: 3156 { 3157 int val; 3158 3159 if (optlen < sizeof(val)) 3160 return -EINVAL; 3161 if (copy_from_user(&val, optval, sizeof(val))) 3162 return -EFAULT; 3163 3164 po->auxdata = !!val; 3165 return 0; 3166 } 3167 case PACKET_ORIGDEV: 3168 { 3169 int val; 3170 3171 if (optlen < sizeof(val)) 3172 return -EINVAL; 3173 if (copy_from_user(&val, optval, sizeof(val))) 3174 return -EFAULT; 3175 3176 po->origdev = !!val; 3177 return 0; 3178 } 3179 case PACKET_VNET_HDR: 3180 { 3181 int val; 3182 3183 if (sock->type != SOCK_RAW) 3184 return -EINVAL; 3185 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3186 return -EBUSY; 3187 if (optlen < sizeof(val)) 3188 return -EINVAL; 3189 if (copy_from_user(&val, optval, sizeof(val))) 3190 return -EFAULT; 3191 3192 po->has_vnet_hdr = !!val; 3193 return 0; 3194 } 3195 case PACKET_TIMESTAMP: 3196 { 3197 int val; 3198 3199 if (optlen != sizeof(val)) 3200 return -EINVAL; 3201 if (copy_from_user(&val, optval, sizeof(val))) 3202 return -EFAULT; 3203 3204 po->tp_tstamp = val; 3205 return 0; 3206 } 3207 case PACKET_FANOUT: 3208 { 3209 int val; 3210 3211 if (optlen != sizeof(val)) 3212 return -EINVAL; 3213 if (copy_from_user(&val, optval, sizeof(val))) 3214 return -EFAULT; 3215 3216 return fanout_add(sk, val & 0xffff, val >> 16); 3217 } 3218 default: 3219 return -ENOPROTOOPT; 3220 } 3221 } 3222 3223 static int packet_getsockopt(struct socket *sock, int level, int optname, 3224 char __user *optval, int __user *optlen) 3225 { 3226 int len; 3227 int val; 3228 struct sock *sk = sock->sk; 3229 struct packet_sock *po = pkt_sk(sk); 3230 void *data; 3231 struct tpacket_stats st; 3232 union tpacket_stats_u st_u; 3233 3234 if (level != SOL_PACKET) 3235 return -ENOPROTOOPT; 3236 3237 if (get_user(len, optlen)) 3238 return -EFAULT; 3239 3240 if (len < 0) 3241 return -EINVAL; 3242 3243 switch (optname) { 3244 case PACKET_STATISTICS: 3245 if (po->tp_version == TPACKET_V3) { 3246 len = sizeof(struct tpacket_stats_v3); 3247 } else { 3248 if (len > sizeof(struct tpacket_stats)) 3249 len = sizeof(struct tpacket_stats); 3250 } 3251 spin_lock_bh(&sk->sk_receive_queue.lock); 3252 if (po->tp_version == TPACKET_V3) { 3253 memcpy(&st_u.stats3, &po->stats, 3254 sizeof(struct tpacket_stats)); 3255 st_u.stats3.tp_freeze_q_cnt = 3256 po->stats_u.stats3.tp_freeze_q_cnt; 3257 st_u.stats3.tp_packets += po->stats.tp_drops; 3258 data = &st_u.stats3; 3259 } else { 3260 st = po->stats; 3261 st.tp_packets += st.tp_drops; 3262 data = &st; 3263 } 3264 memset(&po->stats, 0, sizeof(st)); 3265 spin_unlock_bh(&sk->sk_receive_queue.lock); 3266 break; 3267 case PACKET_AUXDATA: 3268 if (len > sizeof(int)) 3269 len = sizeof(int); 3270 val = po->auxdata; 3271 3272 data = &val; 3273 break; 3274 case PACKET_ORIGDEV: 3275 if (len > sizeof(int)) 3276 len = sizeof(int); 3277 val = po->origdev; 3278 3279 data = &val; 3280 break; 3281 case PACKET_VNET_HDR: 3282 if (len > sizeof(int)) 3283 len = sizeof(int); 3284 val = po->has_vnet_hdr; 3285 3286 data = &val; 3287 break; 3288 case PACKET_VERSION: 3289 if (len > sizeof(int)) 3290 len = sizeof(int); 3291 val = po->tp_version; 3292 data = &val; 3293 break; 3294 case PACKET_HDRLEN: 3295 if (len > sizeof(int)) 3296 len = sizeof(int); 3297 if (copy_from_user(&val, optval, len)) 3298 return -EFAULT; 3299 switch (val) { 3300 case TPACKET_V1: 3301 val = sizeof(struct tpacket_hdr); 3302 break; 3303 case TPACKET_V2: 3304 val = sizeof(struct tpacket2_hdr); 3305 break; 3306 case TPACKET_V3: 3307 val = sizeof(struct tpacket3_hdr); 3308 break; 3309 default: 3310 return -EINVAL; 3311 } 3312 data = &val; 3313 break; 3314 case PACKET_RESERVE: 3315 if (len > sizeof(unsigned int)) 3316 len = sizeof(unsigned int); 3317 val = po->tp_reserve; 3318 data = &val; 3319 break; 3320 case PACKET_LOSS: 3321 if (len > sizeof(unsigned int)) 3322 len = sizeof(unsigned int); 3323 val = po->tp_loss; 3324 data = &val; 3325 break; 3326 case PACKET_TIMESTAMP: 3327 if (len > sizeof(int)) 3328 len = sizeof(int); 3329 val = po->tp_tstamp; 3330 data = &val; 3331 break; 3332 case PACKET_FANOUT: 3333 if (len > sizeof(int)) 3334 len = sizeof(int); 3335 val = (po->fanout ? 3336 ((u32)po->fanout->id | 3337 ((u32)po->fanout->type << 16)) : 3338 0); 3339 data = &val; 3340 break; 3341 default: 3342 return -ENOPROTOOPT; 3343 } 3344 3345 if (put_user(len, optlen)) 3346 return -EFAULT; 3347 if (copy_to_user(optval, data, len)) 3348 return -EFAULT; 3349 return 0; 3350 } 3351 3352 3353 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 3354 { 3355 struct sock *sk; 3356 struct hlist_node *node; 3357 struct net_device *dev = data; 3358 struct net *net = dev_net(dev); 3359 3360 rcu_read_lock(); 3361 sk_for_each_rcu(sk, node, &net->packet.sklist) { 3362 struct packet_sock *po = pkt_sk(sk); 3363 3364 switch (msg) { 3365 case NETDEV_UNREGISTER: 3366 if (po->mclist) 3367 packet_dev_mclist(dev, po->mclist, -1); 3368 /* fallthrough */ 3369 3370 case NETDEV_DOWN: 3371 if (dev->ifindex == po->ifindex) { 3372 spin_lock(&po->bind_lock); 3373 if (po->running) { 3374 __unregister_prot_hook(sk, false); 3375 sk->sk_err = ENETDOWN; 3376 if (!sock_flag(sk, SOCK_DEAD)) 3377 sk->sk_error_report(sk); 3378 } 3379 if (msg == NETDEV_UNREGISTER) { 3380 po->ifindex = -1; 3381 if (po->prot_hook.dev) 3382 dev_put(po->prot_hook.dev); 3383 po->prot_hook.dev = NULL; 3384 } 3385 spin_unlock(&po->bind_lock); 3386 } 3387 break; 3388 case NETDEV_UP: 3389 if (dev->ifindex == po->ifindex) { 3390 spin_lock(&po->bind_lock); 3391 if (po->num) 3392 register_prot_hook(sk); 3393 spin_unlock(&po->bind_lock); 3394 } 3395 break; 3396 } 3397 } 3398 rcu_read_unlock(); 3399 return NOTIFY_DONE; 3400 } 3401 3402 3403 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3404 unsigned long arg) 3405 { 3406 struct sock *sk = sock->sk; 3407 3408 switch (cmd) { 3409 case SIOCOUTQ: 3410 { 3411 int amount = sk_wmem_alloc_get(sk); 3412 3413 return put_user(amount, (int __user *)arg); 3414 } 3415 case SIOCINQ: 3416 { 3417 struct sk_buff *skb; 3418 int amount = 0; 3419 3420 spin_lock_bh(&sk->sk_receive_queue.lock); 3421 skb = skb_peek(&sk->sk_receive_queue); 3422 if (skb) 3423 amount = skb->len; 3424 spin_unlock_bh(&sk->sk_receive_queue.lock); 3425 return put_user(amount, (int __user *)arg); 3426 } 3427 case SIOCGSTAMP: 3428 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3429 case SIOCGSTAMPNS: 3430 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3431 3432 #ifdef CONFIG_INET 3433 case SIOCADDRT: 3434 case SIOCDELRT: 3435 case SIOCDARP: 3436 case SIOCGARP: 3437 case SIOCSARP: 3438 case SIOCGIFADDR: 3439 case SIOCSIFADDR: 3440 case SIOCGIFBRDADDR: 3441 case SIOCSIFBRDADDR: 3442 case SIOCGIFNETMASK: 3443 case SIOCSIFNETMASK: 3444 case SIOCGIFDSTADDR: 3445 case SIOCSIFDSTADDR: 3446 case SIOCSIFFLAGS: 3447 return inet_dgram_ops.ioctl(sock, cmd, arg); 3448 #endif 3449 3450 default: 3451 return -ENOIOCTLCMD; 3452 } 3453 return 0; 3454 } 3455 3456 static unsigned int packet_poll(struct file *file, struct socket *sock, 3457 poll_table *wait) 3458 { 3459 struct sock *sk = sock->sk; 3460 struct packet_sock *po = pkt_sk(sk); 3461 unsigned int mask = datagram_poll(file, sock, wait); 3462 3463 spin_lock_bh(&sk->sk_receive_queue.lock); 3464 if (po->rx_ring.pg_vec) { 3465 if (!packet_previous_rx_frame(po, &po->rx_ring, 3466 TP_STATUS_KERNEL)) 3467 mask |= POLLIN | POLLRDNORM; 3468 } 3469 spin_unlock_bh(&sk->sk_receive_queue.lock); 3470 spin_lock_bh(&sk->sk_write_queue.lock); 3471 if (po->tx_ring.pg_vec) { 3472 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3473 mask |= POLLOUT | POLLWRNORM; 3474 } 3475 spin_unlock_bh(&sk->sk_write_queue.lock); 3476 return mask; 3477 } 3478 3479 3480 /* Dirty? Well, I still did not learn better way to account 3481 * for user mmaps. 3482 */ 3483 3484 static void packet_mm_open(struct vm_area_struct *vma) 3485 { 3486 struct file *file = vma->vm_file; 3487 struct socket *sock = file->private_data; 3488 struct sock *sk = sock->sk; 3489 3490 if (sk) 3491 atomic_inc(&pkt_sk(sk)->mapped); 3492 } 3493 3494 static void packet_mm_close(struct vm_area_struct *vma) 3495 { 3496 struct file *file = vma->vm_file; 3497 struct socket *sock = file->private_data; 3498 struct sock *sk = sock->sk; 3499 3500 if (sk) 3501 atomic_dec(&pkt_sk(sk)->mapped); 3502 } 3503 3504 static const struct vm_operations_struct packet_mmap_ops = { 3505 .open = packet_mm_open, 3506 .close = packet_mm_close, 3507 }; 3508 3509 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3510 unsigned int len) 3511 { 3512 int i; 3513 3514 for (i = 0; i < len; i++) { 3515 if (likely(pg_vec[i].buffer)) { 3516 if (is_vmalloc_addr(pg_vec[i].buffer)) 3517 vfree(pg_vec[i].buffer); 3518 else 3519 free_pages((unsigned long)pg_vec[i].buffer, 3520 order); 3521 pg_vec[i].buffer = NULL; 3522 } 3523 } 3524 kfree(pg_vec); 3525 } 3526 3527 static char *alloc_one_pg_vec_page(unsigned long order) 3528 { 3529 char *buffer = NULL; 3530 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3531 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3532 3533 buffer = (char *) __get_free_pages(gfp_flags, order); 3534 3535 if (buffer) 3536 return buffer; 3537 3538 /* 3539 * __get_free_pages failed, fall back to vmalloc 3540 */ 3541 buffer = vzalloc((1 << order) * PAGE_SIZE); 3542 3543 if (buffer) 3544 return buffer; 3545 3546 /* 3547 * vmalloc failed, lets dig into swap here 3548 */ 3549 gfp_flags &= ~__GFP_NORETRY; 3550 buffer = (char *)__get_free_pages(gfp_flags, order); 3551 if (buffer) 3552 return buffer; 3553 3554 /* 3555 * complete and utter failure 3556 */ 3557 return NULL; 3558 } 3559 3560 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 3561 { 3562 unsigned int block_nr = req->tp_block_nr; 3563 struct pgv *pg_vec; 3564 int i; 3565 3566 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 3567 if (unlikely(!pg_vec)) 3568 goto out; 3569 3570 for (i = 0; i < block_nr; i++) { 3571 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 3572 if (unlikely(!pg_vec[i].buffer)) 3573 goto out_free_pgvec; 3574 } 3575 3576 out: 3577 return pg_vec; 3578 3579 out_free_pgvec: 3580 free_pg_vec(pg_vec, order, block_nr); 3581 pg_vec = NULL; 3582 goto out; 3583 } 3584 3585 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 3586 int closing, int tx_ring) 3587 { 3588 struct pgv *pg_vec = NULL; 3589 struct packet_sock *po = pkt_sk(sk); 3590 int was_running, order = 0; 3591 struct packet_ring_buffer *rb; 3592 struct sk_buff_head *rb_queue; 3593 __be16 num; 3594 int err = -EINVAL; 3595 /* Added to avoid minimal code churn */ 3596 struct tpacket_req *req = &req_u->req; 3597 3598 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 3599 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 3600 WARN(1, "Tx-ring is not supported.\n"); 3601 goto out; 3602 } 3603 3604 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 3605 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 3606 3607 err = -EBUSY; 3608 if (!closing) { 3609 if (atomic_read(&po->mapped)) 3610 goto out; 3611 if (atomic_read(&rb->pending)) 3612 goto out; 3613 } 3614 3615 if (req->tp_block_nr) { 3616 /* Sanity tests and some calculations */ 3617 err = -EBUSY; 3618 if (unlikely(rb->pg_vec)) 3619 goto out; 3620 3621 switch (po->tp_version) { 3622 case TPACKET_V1: 3623 po->tp_hdrlen = TPACKET_HDRLEN; 3624 break; 3625 case TPACKET_V2: 3626 po->tp_hdrlen = TPACKET2_HDRLEN; 3627 break; 3628 case TPACKET_V3: 3629 po->tp_hdrlen = TPACKET3_HDRLEN; 3630 break; 3631 } 3632 3633 err = -EINVAL; 3634 if (unlikely((int)req->tp_block_size <= 0)) 3635 goto out; 3636 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 3637 goto out; 3638 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 3639 po->tp_reserve)) 3640 goto out; 3641 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 3642 goto out; 3643 3644 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 3645 if (unlikely(rb->frames_per_block <= 0)) 3646 goto out; 3647 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 3648 req->tp_frame_nr)) 3649 goto out; 3650 3651 err = -ENOMEM; 3652 order = get_order(req->tp_block_size); 3653 pg_vec = alloc_pg_vec(req, order); 3654 if (unlikely(!pg_vec)) 3655 goto out; 3656 switch (po->tp_version) { 3657 case TPACKET_V3: 3658 /* Transmit path is not supported. We checked 3659 * it above but just being paranoid 3660 */ 3661 if (!tx_ring) 3662 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); 3663 break; 3664 default: 3665 break; 3666 } 3667 } 3668 /* Done */ 3669 else { 3670 err = -EINVAL; 3671 if (unlikely(req->tp_frame_nr)) 3672 goto out; 3673 } 3674 3675 lock_sock(sk); 3676 3677 /* Detach socket from network */ 3678 spin_lock(&po->bind_lock); 3679 was_running = po->running; 3680 num = po->num; 3681 if (was_running) { 3682 po->num = 0; 3683 __unregister_prot_hook(sk, false); 3684 } 3685 spin_unlock(&po->bind_lock); 3686 3687 synchronize_net(); 3688 3689 err = -EBUSY; 3690 mutex_lock(&po->pg_vec_lock); 3691 if (closing || atomic_read(&po->mapped) == 0) { 3692 err = 0; 3693 spin_lock_bh(&rb_queue->lock); 3694 swap(rb->pg_vec, pg_vec); 3695 rb->frame_max = (req->tp_frame_nr - 1); 3696 rb->head = 0; 3697 rb->frame_size = req->tp_frame_size; 3698 spin_unlock_bh(&rb_queue->lock); 3699 3700 swap(rb->pg_vec_order, order); 3701 swap(rb->pg_vec_len, req->tp_block_nr); 3702 3703 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 3704 po->prot_hook.func = (po->rx_ring.pg_vec) ? 3705 tpacket_rcv : packet_rcv; 3706 skb_queue_purge(rb_queue); 3707 if (atomic_read(&po->mapped)) 3708 pr_err("packet_mmap: vma is busy: %d\n", 3709 atomic_read(&po->mapped)); 3710 } 3711 mutex_unlock(&po->pg_vec_lock); 3712 3713 spin_lock(&po->bind_lock); 3714 if (was_running) { 3715 po->num = num; 3716 register_prot_hook(sk); 3717 } 3718 spin_unlock(&po->bind_lock); 3719 if (closing && (po->tp_version > TPACKET_V2)) { 3720 /* Because we don't support block-based V3 on tx-ring */ 3721 if (!tx_ring) 3722 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); 3723 } 3724 release_sock(sk); 3725 3726 if (pg_vec) 3727 free_pg_vec(pg_vec, order, req->tp_block_nr); 3728 out: 3729 return err; 3730 } 3731 3732 static int packet_mmap(struct file *file, struct socket *sock, 3733 struct vm_area_struct *vma) 3734 { 3735 struct sock *sk = sock->sk; 3736 struct packet_sock *po = pkt_sk(sk); 3737 unsigned long size, expected_size; 3738 struct packet_ring_buffer *rb; 3739 unsigned long start; 3740 int err = -EINVAL; 3741 int i; 3742 3743 if (vma->vm_pgoff) 3744 return -EINVAL; 3745 3746 mutex_lock(&po->pg_vec_lock); 3747 3748 expected_size = 0; 3749 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3750 if (rb->pg_vec) { 3751 expected_size += rb->pg_vec_len 3752 * rb->pg_vec_pages 3753 * PAGE_SIZE; 3754 } 3755 } 3756 3757 if (expected_size == 0) 3758 goto out; 3759 3760 size = vma->vm_end - vma->vm_start; 3761 if (size != expected_size) 3762 goto out; 3763 3764 start = vma->vm_start; 3765 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 3766 if (rb->pg_vec == NULL) 3767 continue; 3768 3769 for (i = 0; i < rb->pg_vec_len; i++) { 3770 struct page *page; 3771 void *kaddr = rb->pg_vec[i].buffer; 3772 int pg_num; 3773 3774 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 3775 page = pgv_to_page(kaddr); 3776 err = vm_insert_page(vma, start, page); 3777 if (unlikely(err)) 3778 goto out; 3779 start += PAGE_SIZE; 3780 kaddr += PAGE_SIZE; 3781 } 3782 } 3783 } 3784 3785 atomic_inc(&po->mapped); 3786 vma->vm_ops = &packet_mmap_ops; 3787 err = 0; 3788 3789 out: 3790 mutex_unlock(&po->pg_vec_lock); 3791 return err; 3792 } 3793 3794 static const struct proto_ops packet_ops_spkt = { 3795 .family = PF_PACKET, 3796 .owner = THIS_MODULE, 3797 .release = packet_release, 3798 .bind = packet_bind_spkt, 3799 .connect = sock_no_connect, 3800 .socketpair = sock_no_socketpair, 3801 .accept = sock_no_accept, 3802 .getname = packet_getname_spkt, 3803 .poll = datagram_poll, 3804 .ioctl = packet_ioctl, 3805 .listen = sock_no_listen, 3806 .shutdown = sock_no_shutdown, 3807 .setsockopt = sock_no_setsockopt, 3808 .getsockopt = sock_no_getsockopt, 3809 .sendmsg = packet_sendmsg_spkt, 3810 .recvmsg = packet_recvmsg, 3811 .mmap = sock_no_mmap, 3812 .sendpage = sock_no_sendpage, 3813 }; 3814 3815 static const struct proto_ops packet_ops = { 3816 .family = PF_PACKET, 3817 .owner = THIS_MODULE, 3818 .release = packet_release, 3819 .bind = packet_bind, 3820 .connect = sock_no_connect, 3821 .socketpair = sock_no_socketpair, 3822 .accept = sock_no_accept, 3823 .getname = packet_getname, 3824 .poll = packet_poll, 3825 .ioctl = packet_ioctl, 3826 .listen = sock_no_listen, 3827 .shutdown = sock_no_shutdown, 3828 .setsockopt = packet_setsockopt, 3829 .getsockopt = packet_getsockopt, 3830 .sendmsg = packet_sendmsg, 3831 .recvmsg = packet_recvmsg, 3832 .mmap = packet_mmap, 3833 .sendpage = sock_no_sendpage, 3834 }; 3835 3836 static const struct net_proto_family packet_family_ops = { 3837 .family = PF_PACKET, 3838 .create = packet_create, 3839 .owner = THIS_MODULE, 3840 }; 3841 3842 static struct notifier_block packet_netdev_notifier = { 3843 .notifier_call = packet_notifier, 3844 }; 3845 3846 #ifdef CONFIG_PROC_FS 3847 3848 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 3849 __acquires(RCU) 3850 { 3851 struct net *net = seq_file_net(seq); 3852 3853 rcu_read_lock(); 3854 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 3855 } 3856 3857 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 3858 { 3859 struct net *net = seq_file_net(seq); 3860 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 3861 } 3862 3863 static void packet_seq_stop(struct seq_file *seq, void *v) 3864 __releases(RCU) 3865 { 3866 rcu_read_unlock(); 3867 } 3868 3869 static int packet_seq_show(struct seq_file *seq, void *v) 3870 { 3871 if (v == SEQ_START_TOKEN) 3872 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 3873 else { 3874 struct sock *s = sk_entry(v); 3875 const struct packet_sock *po = pkt_sk(s); 3876 3877 seq_printf(seq, 3878 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 3879 s, 3880 atomic_read(&s->sk_refcnt), 3881 s->sk_type, 3882 ntohs(po->num), 3883 po->ifindex, 3884 po->running, 3885 atomic_read(&s->sk_rmem_alloc), 3886 sock_i_uid(s), 3887 sock_i_ino(s)); 3888 } 3889 3890 return 0; 3891 } 3892 3893 static const struct seq_operations packet_seq_ops = { 3894 .start = packet_seq_start, 3895 .next = packet_seq_next, 3896 .stop = packet_seq_stop, 3897 .show = packet_seq_show, 3898 }; 3899 3900 static int packet_seq_open(struct inode *inode, struct file *file) 3901 { 3902 return seq_open_net(inode, file, &packet_seq_ops, 3903 sizeof(struct seq_net_private)); 3904 } 3905 3906 static const struct file_operations packet_seq_fops = { 3907 .owner = THIS_MODULE, 3908 .open = packet_seq_open, 3909 .read = seq_read, 3910 .llseek = seq_lseek, 3911 .release = seq_release_net, 3912 }; 3913 3914 #endif 3915 3916 static int __net_init packet_net_init(struct net *net) 3917 { 3918 spin_lock_init(&net->packet.sklist_lock); 3919 INIT_HLIST_HEAD(&net->packet.sklist); 3920 3921 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops)) 3922 return -ENOMEM; 3923 3924 return 0; 3925 } 3926 3927 static void __net_exit packet_net_exit(struct net *net) 3928 { 3929 proc_net_remove(net, "packet"); 3930 } 3931 3932 static struct pernet_operations packet_net_ops = { 3933 .init = packet_net_init, 3934 .exit = packet_net_exit, 3935 }; 3936 3937 3938 static void __exit packet_exit(void) 3939 { 3940 unregister_netdevice_notifier(&packet_netdev_notifier); 3941 unregister_pernet_subsys(&packet_net_ops); 3942 sock_unregister(PF_PACKET); 3943 proto_unregister(&packet_proto); 3944 } 3945 3946 static int __init packet_init(void) 3947 { 3948 int rc = proto_register(&packet_proto, 0); 3949 3950 if (rc != 0) 3951 goto out; 3952 3953 sock_register(&packet_family_ops); 3954 register_pernet_subsys(&packet_net_ops); 3955 register_netdevice_notifier(&packet_netdev_notifier); 3956 out: 3957 return rc; 3958 } 3959 3960 module_init(packet_init); 3961 module_exit(packet_exit); 3962 MODULE_LICENSE("GPL"); 3963 MODULE_ALIAS_NETPROTO(PF_PACKET); 3964