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 <linux/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/percpu.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 #include <linux/bpf.h> 96 #include <net/compat.h> 97 98 #include "internal.h" 99 100 /* 101 Assumptions: 102 - if device has no dev->hard_header routine, it adds and removes ll header 103 inside itself. In this case ll header is invisible outside of device, 104 but higher levels still should reserve dev->hard_header_len. 105 Some devices are enough clever to reallocate skb, when header 106 will not fit to reserved space (tunnel), another ones are silly 107 (PPP). 108 - packet socket receives packets with pulled ll header, 109 so that SOCK_RAW should push it back. 110 111 On receive: 112 ----------- 113 114 Incoming, dev->hard_header!=NULL 115 mac_header -> ll header 116 data -> data 117 118 Outgoing, dev->hard_header!=NULL 119 mac_header -> ll header 120 data -> ll header 121 122 Incoming, dev->hard_header==NULL 123 mac_header -> UNKNOWN position. It is very likely, that it points to ll 124 header. PPP makes it, that is wrong, because introduce 125 assymetry between rx and tx paths. 126 data -> data 127 128 Outgoing, dev->hard_header==NULL 129 mac_header -> data. ll header is still not built! 130 data -> data 131 132 Resume 133 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 134 135 136 On transmit: 137 ------------ 138 139 dev->hard_header != NULL 140 mac_header -> ll header 141 data -> ll header 142 143 dev->hard_header == NULL (ll header is added by device, we cannot control it) 144 mac_header -> data 145 data -> data 146 147 We should set nh.raw on output to correct posistion, 148 packet classifier depends on it. 149 */ 150 151 /* Private packet socket structures. */ 152 153 /* identical to struct packet_mreq except it has 154 * a longer address field. 155 */ 156 struct packet_mreq_max { 157 int mr_ifindex; 158 unsigned short mr_type; 159 unsigned short mr_alen; 160 unsigned char mr_address[MAX_ADDR_LEN]; 161 }; 162 163 union tpacket_uhdr { 164 struct tpacket_hdr *h1; 165 struct tpacket2_hdr *h2; 166 struct tpacket3_hdr *h3; 167 void *raw; 168 }; 169 170 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 171 int closing, int tx_ring); 172 173 #define V3_ALIGNMENT (8) 174 175 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 176 177 #define BLK_PLUS_PRIV(sz_of_priv) \ 178 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 179 180 #define PGV_FROM_VMALLOC 1 181 182 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 183 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 184 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 185 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 186 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 187 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 188 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 189 190 struct packet_sock; 191 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 192 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 193 struct packet_type *pt, struct net_device *orig_dev); 194 195 static void *packet_previous_frame(struct packet_sock *po, 196 struct packet_ring_buffer *rb, 197 int status); 198 static void packet_increment_head(struct packet_ring_buffer *buff); 199 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 200 struct tpacket_block_desc *); 201 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 202 struct packet_sock *); 203 static void prb_retire_current_block(struct tpacket_kbdq_core *, 204 struct packet_sock *, unsigned int status); 205 static int prb_queue_frozen(struct tpacket_kbdq_core *); 206 static void prb_open_block(struct tpacket_kbdq_core *, 207 struct tpacket_block_desc *); 208 static void prb_retire_rx_blk_timer_expired(unsigned long); 209 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 210 static void prb_init_blk_timer(struct packet_sock *, 211 struct tpacket_kbdq_core *, 212 void (*func) (unsigned long)); 213 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 214 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 215 struct tpacket3_hdr *); 216 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 217 struct tpacket3_hdr *); 218 static void packet_flush_mclist(struct sock *sk); 219 220 struct packet_skb_cb { 221 union { 222 struct sockaddr_pkt pkt; 223 union { 224 /* Trick: alias skb original length with 225 * ll.sll_family and ll.protocol in order 226 * to save room. 227 */ 228 unsigned int origlen; 229 struct sockaddr_ll ll; 230 }; 231 } sa; 232 }; 233 234 #define vio_le() virtio_legacy_is_little_endian() 235 236 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 237 238 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 239 #define GET_PBLOCK_DESC(x, bid) \ 240 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 241 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 242 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 243 #define GET_NEXT_PRB_BLK_NUM(x) \ 244 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 245 ((x)->kactive_blk_num+1) : 0) 246 247 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 248 static void __fanout_link(struct sock *sk, struct packet_sock *po); 249 250 static int packet_direct_xmit(struct sk_buff *skb) 251 { 252 struct net_device *dev = skb->dev; 253 struct sk_buff *orig_skb = skb; 254 struct netdev_queue *txq; 255 int ret = NETDEV_TX_BUSY; 256 257 if (unlikely(!netif_running(dev) || 258 !netif_carrier_ok(dev))) 259 goto drop; 260 261 skb = validate_xmit_skb_list(skb, dev); 262 if (skb != orig_skb) 263 goto drop; 264 265 txq = skb_get_tx_queue(dev, skb); 266 267 local_bh_disable(); 268 269 HARD_TX_LOCK(dev, txq, smp_processor_id()); 270 if (!netif_xmit_frozen_or_drv_stopped(txq)) 271 ret = netdev_start_xmit(skb, dev, txq, false); 272 HARD_TX_UNLOCK(dev, txq); 273 274 local_bh_enable(); 275 276 if (!dev_xmit_complete(ret)) 277 kfree_skb(skb); 278 279 return ret; 280 drop: 281 atomic_long_inc(&dev->tx_dropped); 282 kfree_skb_list(skb); 283 return NET_XMIT_DROP; 284 } 285 286 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 287 { 288 struct net_device *dev; 289 290 rcu_read_lock(); 291 dev = rcu_dereference(po->cached_dev); 292 if (likely(dev)) 293 dev_hold(dev); 294 rcu_read_unlock(); 295 296 return dev; 297 } 298 299 static void packet_cached_dev_assign(struct packet_sock *po, 300 struct net_device *dev) 301 { 302 rcu_assign_pointer(po->cached_dev, dev); 303 } 304 305 static void packet_cached_dev_reset(struct packet_sock *po) 306 { 307 RCU_INIT_POINTER(po->cached_dev, NULL); 308 } 309 310 static bool packet_use_direct_xmit(const struct packet_sock *po) 311 { 312 return po->xmit == packet_direct_xmit; 313 } 314 315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 316 { 317 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues; 318 } 319 320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 321 { 322 const struct net_device_ops *ops = dev->netdev_ops; 323 u16 queue_index; 324 325 if (ops->ndo_select_queue) { 326 queue_index = ops->ndo_select_queue(dev, skb, NULL, 327 __packet_pick_tx_queue); 328 queue_index = netdev_cap_txqueue(dev, queue_index); 329 } else { 330 queue_index = __packet_pick_tx_queue(dev, skb); 331 } 332 333 skb_set_queue_mapping(skb, queue_index); 334 } 335 336 /* register_prot_hook must be invoked with the po->bind_lock held, 337 * or from a context in which asynchronous accesses to the packet 338 * socket is not possible (packet_create()). 339 */ 340 static void register_prot_hook(struct sock *sk) 341 { 342 struct packet_sock *po = pkt_sk(sk); 343 344 if (!po->running) { 345 if (po->fanout) 346 __fanout_link(sk, po); 347 else 348 dev_add_pack(&po->prot_hook); 349 350 sock_hold(sk); 351 po->running = 1; 352 } 353 } 354 355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 356 * held. If the sync parameter is true, we will temporarily drop 357 * the po->bind_lock and do a synchronize_net to make sure no 358 * asynchronous packet processing paths still refer to the elements 359 * of po->prot_hook. If the sync parameter is false, it is the 360 * callers responsibility to take care of this. 361 */ 362 static void __unregister_prot_hook(struct sock *sk, bool sync) 363 { 364 struct packet_sock *po = pkt_sk(sk); 365 366 po->running = 0; 367 368 if (po->fanout) 369 __fanout_unlink(sk, po); 370 else 371 __dev_remove_pack(&po->prot_hook); 372 373 __sock_put(sk); 374 375 if (sync) { 376 spin_unlock(&po->bind_lock); 377 synchronize_net(); 378 spin_lock(&po->bind_lock); 379 } 380 } 381 382 static void unregister_prot_hook(struct sock *sk, bool sync) 383 { 384 struct packet_sock *po = pkt_sk(sk); 385 386 if (po->running) 387 __unregister_prot_hook(sk, sync); 388 } 389 390 static inline struct page * __pure pgv_to_page(void *addr) 391 { 392 if (is_vmalloc_addr(addr)) 393 return vmalloc_to_page(addr); 394 return virt_to_page(addr); 395 } 396 397 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 398 { 399 union tpacket_uhdr h; 400 401 h.raw = frame; 402 switch (po->tp_version) { 403 case TPACKET_V1: 404 h.h1->tp_status = status; 405 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 406 break; 407 case TPACKET_V2: 408 h.h2->tp_status = status; 409 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 410 break; 411 case TPACKET_V3: 412 h.h3->tp_status = status; 413 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 414 break; 415 default: 416 WARN(1, "TPACKET version not supported.\n"); 417 BUG(); 418 } 419 420 smp_wmb(); 421 } 422 423 static int __packet_get_status(struct packet_sock *po, void *frame) 424 { 425 union tpacket_uhdr h; 426 427 smp_rmb(); 428 429 h.raw = frame; 430 switch (po->tp_version) { 431 case TPACKET_V1: 432 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 433 return h.h1->tp_status; 434 case TPACKET_V2: 435 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 436 return h.h2->tp_status; 437 case TPACKET_V3: 438 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 439 return h.h3->tp_status; 440 default: 441 WARN(1, "TPACKET version not supported.\n"); 442 BUG(); 443 return 0; 444 } 445 } 446 447 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 448 unsigned int flags) 449 { 450 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 451 452 if (shhwtstamps && 453 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 454 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 455 return TP_STATUS_TS_RAW_HARDWARE; 456 457 if (ktime_to_timespec_cond(skb->tstamp, ts)) 458 return TP_STATUS_TS_SOFTWARE; 459 460 return 0; 461 } 462 463 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 464 struct sk_buff *skb) 465 { 466 union tpacket_uhdr h; 467 struct timespec ts; 468 __u32 ts_status; 469 470 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 471 return 0; 472 473 h.raw = frame; 474 switch (po->tp_version) { 475 case TPACKET_V1: 476 h.h1->tp_sec = ts.tv_sec; 477 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 478 break; 479 case TPACKET_V2: 480 h.h2->tp_sec = ts.tv_sec; 481 h.h2->tp_nsec = ts.tv_nsec; 482 break; 483 case TPACKET_V3: 484 h.h3->tp_sec = ts.tv_sec; 485 h.h3->tp_nsec = ts.tv_nsec; 486 break; 487 default: 488 WARN(1, "TPACKET version not supported.\n"); 489 BUG(); 490 } 491 492 /* one flush is safe, as both fields always lie on the same cacheline */ 493 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 494 smp_wmb(); 495 496 return ts_status; 497 } 498 499 static void *packet_lookup_frame(struct packet_sock *po, 500 struct packet_ring_buffer *rb, 501 unsigned int position, 502 int status) 503 { 504 unsigned int pg_vec_pos, frame_offset; 505 union tpacket_uhdr h; 506 507 pg_vec_pos = position / rb->frames_per_block; 508 frame_offset = position % rb->frames_per_block; 509 510 h.raw = rb->pg_vec[pg_vec_pos].buffer + 511 (frame_offset * rb->frame_size); 512 513 if (status != __packet_get_status(po, h.raw)) 514 return NULL; 515 516 return h.raw; 517 } 518 519 static void *packet_current_frame(struct packet_sock *po, 520 struct packet_ring_buffer *rb, 521 int status) 522 { 523 return packet_lookup_frame(po, rb, rb->head, status); 524 } 525 526 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 527 { 528 del_timer_sync(&pkc->retire_blk_timer); 529 } 530 531 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 532 struct sk_buff_head *rb_queue) 533 { 534 struct tpacket_kbdq_core *pkc; 535 536 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 537 538 spin_lock_bh(&rb_queue->lock); 539 pkc->delete_blk_timer = 1; 540 spin_unlock_bh(&rb_queue->lock); 541 542 prb_del_retire_blk_timer(pkc); 543 } 544 545 static void prb_init_blk_timer(struct packet_sock *po, 546 struct tpacket_kbdq_core *pkc, 547 void (*func) (unsigned long)) 548 { 549 init_timer(&pkc->retire_blk_timer); 550 pkc->retire_blk_timer.data = (long)po; 551 pkc->retire_blk_timer.function = func; 552 pkc->retire_blk_timer.expires = jiffies; 553 } 554 555 static void prb_setup_retire_blk_timer(struct packet_sock *po) 556 { 557 struct tpacket_kbdq_core *pkc; 558 559 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 560 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 561 } 562 563 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 564 int blk_size_in_bytes) 565 { 566 struct net_device *dev; 567 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 568 struct ethtool_link_ksettings ecmd; 569 int err; 570 571 rtnl_lock(); 572 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 573 if (unlikely(!dev)) { 574 rtnl_unlock(); 575 return DEFAULT_PRB_RETIRE_TOV; 576 } 577 err = __ethtool_get_link_ksettings(dev, &ecmd); 578 rtnl_unlock(); 579 if (!err) { 580 /* 581 * If the link speed is so slow you don't really 582 * need to worry about perf anyways 583 */ 584 if (ecmd.base.speed < SPEED_1000 || 585 ecmd.base.speed == SPEED_UNKNOWN) { 586 return DEFAULT_PRB_RETIRE_TOV; 587 } else { 588 msec = 1; 589 div = ecmd.base.speed / 1000; 590 } 591 } 592 593 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 594 595 if (div) 596 mbits /= div; 597 598 tmo = mbits * msec; 599 600 if (div) 601 return tmo+1; 602 return tmo; 603 } 604 605 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 606 union tpacket_req_u *req_u) 607 { 608 p1->feature_req_word = req_u->req3.tp_feature_req_word; 609 } 610 611 static void init_prb_bdqc(struct packet_sock *po, 612 struct packet_ring_buffer *rb, 613 struct pgv *pg_vec, 614 union tpacket_req_u *req_u) 615 { 616 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 617 struct tpacket_block_desc *pbd; 618 619 memset(p1, 0x0, sizeof(*p1)); 620 621 p1->knxt_seq_num = 1; 622 p1->pkbdq = pg_vec; 623 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 624 p1->pkblk_start = pg_vec[0].buffer; 625 p1->kblk_size = req_u->req3.tp_block_size; 626 p1->knum_blocks = req_u->req3.tp_block_nr; 627 p1->hdrlen = po->tp_hdrlen; 628 p1->version = po->tp_version; 629 p1->last_kactive_blk_num = 0; 630 po->stats.stats3.tp_freeze_q_cnt = 0; 631 if (req_u->req3.tp_retire_blk_tov) 632 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 633 else 634 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 635 req_u->req3.tp_block_size); 636 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 637 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 638 639 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 640 prb_init_ft_ops(p1, req_u); 641 prb_setup_retire_blk_timer(po); 642 prb_open_block(p1, pbd); 643 } 644 645 /* Do NOT update the last_blk_num first. 646 * Assumes sk_buff_head lock is held. 647 */ 648 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 649 { 650 mod_timer(&pkc->retire_blk_timer, 651 jiffies + pkc->tov_in_jiffies); 652 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 653 } 654 655 /* 656 * Timer logic: 657 * 1) We refresh the timer only when we open a block. 658 * By doing this we don't waste cycles refreshing the timer 659 * on packet-by-packet basis. 660 * 661 * With a 1MB block-size, on a 1Gbps line, it will take 662 * i) ~8 ms to fill a block + ii) memcpy etc. 663 * In this cut we are not accounting for the memcpy time. 664 * 665 * So, if the user sets the 'tmo' to 10ms then the timer 666 * will never fire while the block is still getting filled 667 * (which is what we want). However, the user could choose 668 * to close a block early and that's fine. 669 * 670 * But when the timer does fire, we check whether or not to refresh it. 671 * Since the tmo granularity is in msecs, it is not too expensive 672 * to refresh the timer, lets say every '8' msecs. 673 * Either the user can set the 'tmo' or we can derive it based on 674 * a) line-speed and b) block-size. 675 * prb_calc_retire_blk_tmo() calculates the tmo. 676 * 677 */ 678 static void prb_retire_rx_blk_timer_expired(unsigned long data) 679 { 680 struct packet_sock *po = (struct packet_sock *)data; 681 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 682 unsigned int frozen; 683 struct tpacket_block_desc *pbd; 684 685 spin_lock(&po->sk.sk_receive_queue.lock); 686 687 frozen = prb_queue_frozen(pkc); 688 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 689 690 if (unlikely(pkc->delete_blk_timer)) 691 goto out; 692 693 /* We only need to plug the race when the block is partially filled. 694 * tpacket_rcv: 695 * lock(); increment BLOCK_NUM_PKTS; unlock() 696 * copy_bits() is in progress ... 697 * timer fires on other cpu: 698 * we can't retire the current block because copy_bits 699 * is in progress. 700 * 701 */ 702 if (BLOCK_NUM_PKTS(pbd)) { 703 while (atomic_read(&pkc->blk_fill_in_prog)) { 704 /* Waiting for skb_copy_bits to finish... */ 705 cpu_relax(); 706 } 707 } 708 709 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 710 if (!frozen) { 711 if (!BLOCK_NUM_PKTS(pbd)) { 712 /* An empty block. Just refresh the timer. */ 713 goto refresh_timer; 714 } 715 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 716 if (!prb_dispatch_next_block(pkc, po)) 717 goto refresh_timer; 718 else 719 goto out; 720 } else { 721 /* Case 1. Queue was frozen because user-space was 722 * lagging behind. 723 */ 724 if (prb_curr_blk_in_use(pkc, pbd)) { 725 /* 726 * Ok, user-space is still behind. 727 * So just refresh the timer. 728 */ 729 goto refresh_timer; 730 } else { 731 /* Case 2. queue was frozen,user-space caught up, 732 * now the link went idle && the timer fired. 733 * We don't have a block to close.So we open this 734 * block and restart the timer. 735 * opening a block thaws the queue,restarts timer 736 * Thawing/timer-refresh is a side effect. 737 */ 738 prb_open_block(pkc, pbd); 739 goto out; 740 } 741 } 742 } 743 744 refresh_timer: 745 _prb_refresh_rx_retire_blk_timer(pkc); 746 747 out: 748 spin_unlock(&po->sk.sk_receive_queue.lock); 749 } 750 751 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 752 struct tpacket_block_desc *pbd1, __u32 status) 753 { 754 /* Flush everything minus the block header */ 755 756 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 757 u8 *start, *end; 758 759 start = (u8 *)pbd1; 760 761 /* Skip the block header(we know header WILL fit in 4K) */ 762 start += PAGE_SIZE; 763 764 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 765 for (; start < end; start += PAGE_SIZE) 766 flush_dcache_page(pgv_to_page(start)); 767 768 smp_wmb(); 769 #endif 770 771 /* Now update the block status. */ 772 773 BLOCK_STATUS(pbd1) = status; 774 775 /* Flush the block header */ 776 777 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 778 start = (u8 *)pbd1; 779 flush_dcache_page(pgv_to_page(start)); 780 781 smp_wmb(); 782 #endif 783 } 784 785 /* 786 * Side effect: 787 * 788 * 1) flush the block 789 * 2) Increment active_blk_num 790 * 791 * Note:We DONT refresh the timer on purpose. 792 * Because almost always the next block will be opened. 793 */ 794 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 795 struct tpacket_block_desc *pbd1, 796 struct packet_sock *po, unsigned int stat) 797 { 798 __u32 status = TP_STATUS_USER | stat; 799 800 struct tpacket3_hdr *last_pkt; 801 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 802 struct sock *sk = &po->sk; 803 804 if (po->stats.stats3.tp_drops) 805 status |= TP_STATUS_LOSING; 806 807 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 808 last_pkt->tp_next_offset = 0; 809 810 /* Get the ts of the last pkt */ 811 if (BLOCK_NUM_PKTS(pbd1)) { 812 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 813 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 814 } else { 815 /* Ok, we tmo'd - so get the current time. 816 * 817 * It shouldn't really happen as we don't close empty 818 * blocks. See prb_retire_rx_blk_timer_expired(). 819 */ 820 struct timespec ts; 821 getnstimeofday(&ts); 822 h1->ts_last_pkt.ts_sec = ts.tv_sec; 823 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 824 } 825 826 smp_wmb(); 827 828 /* Flush the block */ 829 prb_flush_block(pkc1, pbd1, status); 830 831 sk->sk_data_ready(sk); 832 833 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 834 } 835 836 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 837 { 838 pkc->reset_pending_on_curr_blk = 0; 839 } 840 841 /* 842 * Side effect of opening a block: 843 * 844 * 1) prb_queue is thawed. 845 * 2) retire_blk_timer is refreshed. 846 * 847 */ 848 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 849 struct tpacket_block_desc *pbd1) 850 { 851 struct timespec ts; 852 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 853 854 smp_rmb(); 855 856 /* We could have just memset this but we will lose the 857 * flexibility of making the priv area sticky 858 */ 859 860 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 861 BLOCK_NUM_PKTS(pbd1) = 0; 862 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 863 864 getnstimeofday(&ts); 865 866 h1->ts_first_pkt.ts_sec = ts.tv_sec; 867 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 868 869 pkc1->pkblk_start = (char *)pbd1; 870 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 871 872 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 873 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 874 875 pbd1->version = pkc1->version; 876 pkc1->prev = pkc1->nxt_offset; 877 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 878 879 prb_thaw_queue(pkc1); 880 _prb_refresh_rx_retire_blk_timer(pkc1); 881 882 smp_wmb(); 883 } 884 885 /* 886 * Queue freeze logic: 887 * 1) Assume tp_block_nr = 8 blocks. 888 * 2) At time 't0', user opens Rx ring. 889 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 890 * 4) user-space is either sleeping or processing block '0'. 891 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 892 * it will close block-7,loop around and try to fill block '0'. 893 * call-flow: 894 * __packet_lookup_frame_in_block 895 * prb_retire_current_block() 896 * prb_dispatch_next_block() 897 * |->(BLOCK_STATUS == USER) evaluates to true 898 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 899 * 6) Now there are two cases: 900 * 6.1) Link goes idle right after the queue is frozen. 901 * But remember, the last open_block() refreshed the timer. 902 * When this timer expires,it will refresh itself so that we can 903 * re-open block-0 in near future. 904 * 6.2) Link is busy and keeps on receiving packets. This is a simple 905 * case and __packet_lookup_frame_in_block will check if block-0 906 * is free and can now be re-used. 907 */ 908 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 909 struct packet_sock *po) 910 { 911 pkc->reset_pending_on_curr_blk = 1; 912 po->stats.stats3.tp_freeze_q_cnt++; 913 } 914 915 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 916 917 /* 918 * If the next block is free then we will dispatch it 919 * and return a good offset. 920 * Else, we will freeze the queue. 921 * So, caller must check the return value. 922 */ 923 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 924 struct packet_sock *po) 925 { 926 struct tpacket_block_desc *pbd; 927 928 smp_rmb(); 929 930 /* 1. Get current block num */ 931 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 932 933 /* 2. If this block is currently in_use then freeze the queue */ 934 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 935 prb_freeze_queue(pkc, po); 936 return NULL; 937 } 938 939 /* 940 * 3. 941 * open this block and return the offset where the first packet 942 * needs to get stored. 943 */ 944 prb_open_block(pkc, pbd); 945 return (void *)pkc->nxt_offset; 946 } 947 948 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 949 struct packet_sock *po, unsigned int status) 950 { 951 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 952 953 /* retire/close the current block */ 954 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 955 /* 956 * Plug the case where copy_bits() is in progress on 957 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 958 * have space to copy the pkt in the current block and 959 * called prb_retire_current_block() 960 * 961 * We don't need to worry about the TMO case because 962 * the timer-handler already handled this case. 963 */ 964 if (!(status & TP_STATUS_BLK_TMO)) { 965 while (atomic_read(&pkc->blk_fill_in_prog)) { 966 /* Waiting for skb_copy_bits to finish... */ 967 cpu_relax(); 968 } 969 } 970 prb_close_block(pkc, pbd, po, status); 971 return; 972 } 973 } 974 975 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 976 struct tpacket_block_desc *pbd) 977 { 978 return TP_STATUS_USER & BLOCK_STATUS(pbd); 979 } 980 981 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 982 { 983 return pkc->reset_pending_on_curr_blk; 984 } 985 986 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 987 { 988 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 989 atomic_dec(&pkc->blk_fill_in_prog); 990 } 991 992 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 993 struct tpacket3_hdr *ppd) 994 { 995 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 996 } 997 998 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 999 struct tpacket3_hdr *ppd) 1000 { 1001 ppd->hv1.tp_rxhash = 0; 1002 } 1003 1004 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 1005 struct tpacket3_hdr *ppd) 1006 { 1007 if (skb_vlan_tag_present(pkc->skb)) { 1008 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1009 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1010 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1011 } else { 1012 ppd->hv1.tp_vlan_tci = 0; 1013 ppd->hv1.tp_vlan_tpid = 0; 1014 ppd->tp_status = TP_STATUS_AVAILABLE; 1015 } 1016 } 1017 1018 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1019 struct tpacket3_hdr *ppd) 1020 { 1021 ppd->hv1.tp_padding = 0; 1022 prb_fill_vlan_info(pkc, ppd); 1023 1024 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1025 prb_fill_rxhash(pkc, ppd); 1026 else 1027 prb_clear_rxhash(pkc, ppd); 1028 } 1029 1030 static void prb_fill_curr_block(char *curr, 1031 struct tpacket_kbdq_core *pkc, 1032 struct tpacket_block_desc *pbd, 1033 unsigned int len) 1034 { 1035 struct tpacket3_hdr *ppd; 1036 1037 ppd = (struct tpacket3_hdr *)curr; 1038 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1039 pkc->prev = curr; 1040 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1041 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1042 BLOCK_NUM_PKTS(pbd) += 1; 1043 atomic_inc(&pkc->blk_fill_in_prog); 1044 prb_run_all_ft_ops(pkc, ppd); 1045 } 1046 1047 /* Assumes caller has the sk->rx_queue.lock */ 1048 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1049 struct sk_buff *skb, 1050 int status, 1051 unsigned int len 1052 ) 1053 { 1054 struct tpacket_kbdq_core *pkc; 1055 struct tpacket_block_desc *pbd; 1056 char *curr, *end; 1057 1058 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1059 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1060 1061 /* Queue is frozen when user space is lagging behind */ 1062 if (prb_queue_frozen(pkc)) { 1063 /* 1064 * Check if that last block which caused the queue to freeze, 1065 * is still in_use by user-space. 1066 */ 1067 if (prb_curr_blk_in_use(pkc, pbd)) { 1068 /* Can't record this packet */ 1069 return NULL; 1070 } else { 1071 /* 1072 * Ok, the block was released by user-space. 1073 * Now let's open that block. 1074 * opening a block also thaws the queue. 1075 * Thawing is a side effect. 1076 */ 1077 prb_open_block(pkc, pbd); 1078 } 1079 } 1080 1081 smp_mb(); 1082 curr = pkc->nxt_offset; 1083 pkc->skb = skb; 1084 end = (char *)pbd + pkc->kblk_size; 1085 1086 /* first try the current block */ 1087 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1088 prb_fill_curr_block(curr, pkc, pbd, len); 1089 return (void *)curr; 1090 } 1091 1092 /* Ok, close the current block */ 1093 prb_retire_current_block(pkc, po, 0); 1094 1095 /* Now, try to dispatch the next block */ 1096 curr = (char *)prb_dispatch_next_block(pkc, po); 1097 if (curr) { 1098 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1099 prb_fill_curr_block(curr, pkc, pbd, len); 1100 return (void *)curr; 1101 } 1102 1103 /* 1104 * No free blocks are available.user_space hasn't caught up yet. 1105 * Queue was just frozen and now this packet will get dropped. 1106 */ 1107 return NULL; 1108 } 1109 1110 static void *packet_current_rx_frame(struct packet_sock *po, 1111 struct sk_buff *skb, 1112 int status, unsigned int len) 1113 { 1114 char *curr = NULL; 1115 switch (po->tp_version) { 1116 case TPACKET_V1: 1117 case TPACKET_V2: 1118 curr = packet_lookup_frame(po, &po->rx_ring, 1119 po->rx_ring.head, status); 1120 return curr; 1121 case TPACKET_V3: 1122 return __packet_lookup_frame_in_block(po, skb, status, len); 1123 default: 1124 WARN(1, "TPACKET version not supported\n"); 1125 BUG(); 1126 return NULL; 1127 } 1128 } 1129 1130 static void *prb_lookup_block(struct packet_sock *po, 1131 struct packet_ring_buffer *rb, 1132 unsigned int idx, 1133 int status) 1134 { 1135 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1136 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1137 1138 if (status != BLOCK_STATUS(pbd)) 1139 return NULL; 1140 return pbd; 1141 } 1142 1143 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1144 { 1145 unsigned int prev; 1146 if (rb->prb_bdqc.kactive_blk_num) 1147 prev = rb->prb_bdqc.kactive_blk_num-1; 1148 else 1149 prev = rb->prb_bdqc.knum_blocks-1; 1150 return prev; 1151 } 1152 1153 /* Assumes caller has held the rx_queue.lock */ 1154 static void *__prb_previous_block(struct packet_sock *po, 1155 struct packet_ring_buffer *rb, 1156 int status) 1157 { 1158 unsigned int previous = prb_previous_blk_num(rb); 1159 return prb_lookup_block(po, rb, previous, status); 1160 } 1161 1162 static void *packet_previous_rx_frame(struct packet_sock *po, 1163 struct packet_ring_buffer *rb, 1164 int status) 1165 { 1166 if (po->tp_version <= TPACKET_V2) 1167 return packet_previous_frame(po, rb, status); 1168 1169 return __prb_previous_block(po, rb, status); 1170 } 1171 1172 static void packet_increment_rx_head(struct packet_sock *po, 1173 struct packet_ring_buffer *rb) 1174 { 1175 switch (po->tp_version) { 1176 case TPACKET_V1: 1177 case TPACKET_V2: 1178 return packet_increment_head(rb); 1179 case TPACKET_V3: 1180 default: 1181 WARN(1, "TPACKET version not supported.\n"); 1182 BUG(); 1183 return; 1184 } 1185 } 1186 1187 static void *packet_previous_frame(struct packet_sock *po, 1188 struct packet_ring_buffer *rb, 1189 int status) 1190 { 1191 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1192 return packet_lookup_frame(po, rb, previous, status); 1193 } 1194 1195 static void packet_increment_head(struct packet_ring_buffer *buff) 1196 { 1197 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1198 } 1199 1200 static void packet_inc_pending(struct packet_ring_buffer *rb) 1201 { 1202 this_cpu_inc(*rb->pending_refcnt); 1203 } 1204 1205 static void packet_dec_pending(struct packet_ring_buffer *rb) 1206 { 1207 this_cpu_dec(*rb->pending_refcnt); 1208 } 1209 1210 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1211 { 1212 unsigned int refcnt = 0; 1213 int cpu; 1214 1215 /* We don't use pending refcount in rx_ring. */ 1216 if (rb->pending_refcnt == NULL) 1217 return 0; 1218 1219 for_each_possible_cpu(cpu) 1220 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1221 1222 return refcnt; 1223 } 1224 1225 static int packet_alloc_pending(struct packet_sock *po) 1226 { 1227 po->rx_ring.pending_refcnt = NULL; 1228 1229 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1230 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1231 return -ENOBUFS; 1232 1233 return 0; 1234 } 1235 1236 static void packet_free_pending(struct packet_sock *po) 1237 { 1238 free_percpu(po->tx_ring.pending_refcnt); 1239 } 1240 1241 #define ROOM_POW_OFF 2 1242 #define ROOM_NONE 0x0 1243 #define ROOM_LOW 0x1 1244 #define ROOM_NORMAL 0x2 1245 1246 static bool __tpacket_has_room(struct packet_sock *po, int pow_off) 1247 { 1248 int idx, len; 1249 1250 len = po->rx_ring.frame_max + 1; 1251 idx = po->rx_ring.head; 1252 if (pow_off) 1253 idx += len >> pow_off; 1254 if (idx >= len) 1255 idx -= len; 1256 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1257 } 1258 1259 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off) 1260 { 1261 int idx, len; 1262 1263 len = po->rx_ring.prb_bdqc.knum_blocks; 1264 idx = po->rx_ring.prb_bdqc.kactive_blk_num; 1265 if (pow_off) 1266 idx += len >> pow_off; 1267 if (idx >= len) 1268 idx -= len; 1269 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1270 } 1271 1272 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1273 { 1274 struct sock *sk = &po->sk; 1275 int ret = ROOM_NONE; 1276 1277 if (po->prot_hook.func != tpacket_rcv) { 1278 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1279 - (skb ? skb->truesize : 0); 1280 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF)) 1281 return ROOM_NORMAL; 1282 else if (avail > 0) 1283 return ROOM_LOW; 1284 else 1285 return ROOM_NONE; 1286 } 1287 1288 if (po->tp_version == TPACKET_V3) { 1289 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1290 ret = ROOM_NORMAL; 1291 else if (__tpacket_v3_has_room(po, 0)) 1292 ret = ROOM_LOW; 1293 } else { 1294 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1295 ret = ROOM_NORMAL; 1296 else if (__tpacket_has_room(po, 0)) 1297 ret = ROOM_LOW; 1298 } 1299 1300 return ret; 1301 } 1302 1303 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1304 { 1305 int ret; 1306 bool has_room; 1307 1308 spin_lock_bh(&po->sk.sk_receive_queue.lock); 1309 ret = __packet_rcv_has_room(po, skb); 1310 has_room = ret == ROOM_NORMAL; 1311 if (po->pressure == has_room) 1312 po->pressure = !has_room; 1313 spin_unlock_bh(&po->sk.sk_receive_queue.lock); 1314 1315 return ret; 1316 } 1317 1318 static void packet_sock_destruct(struct sock *sk) 1319 { 1320 skb_queue_purge(&sk->sk_error_queue); 1321 1322 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1323 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1324 1325 if (!sock_flag(sk, SOCK_DEAD)) { 1326 pr_err("Attempt to release alive packet socket: %p\n", sk); 1327 return; 1328 } 1329 1330 sk_refcnt_debug_dec(sk); 1331 } 1332 1333 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1334 { 1335 u32 rxhash; 1336 int i, count = 0; 1337 1338 rxhash = skb_get_hash(skb); 1339 for (i = 0; i < ROLLOVER_HLEN; i++) 1340 if (po->rollover->history[i] == rxhash) 1341 count++; 1342 1343 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash; 1344 return count > (ROLLOVER_HLEN >> 1); 1345 } 1346 1347 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1348 struct sk_buff *skb, 1349 unsigned int num) 1350 { 1351 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1352 } 1353 1354 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1355 struct sk_buff *skb, 1356 unsigned int num) 1357 { 1358 unsigned int val = atomic_inc_return(&f->rr_cur); 1359 1360 return val % num; 1361 } 1362 1363 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1364 struct sk_buff *skb, 1365 unsigned int num) 1366 { 1367 return smp_processor_id() % num; 1368 } 1369 1370 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1371 struct sk_buff *skb, 1372 unsigned int num) 1373 { 1374 return prandom_u32_max(num); 1375 } 1376 1377 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1378 struct sk_buff *skb, 1379 unsigned int idx, bool try_self, 1380 unsigned int num) 1381 { 1382 struct packet_sock *po, *po_next, *po_skip = NULL; 1383 unsigned int i, j, room = ROOM_NONE; 1384 1385 po = pkt_sk(f->arr[idx]); 1386 1387 if (try_self) { 1388 room = packet_rcv_has_room(po, skb); 1389 if (room == ROOM_NORMAL || 1390 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1391 return idx; 1392 po_skip = po; 1393 } 1394 1395 i = j = min_t(int, po->rollover->sock, num - 1); 1396 do { 1397 po_next = pkt_sk(f->arr[i]); 1398 if (po_next != po_skip && !po_next->pressure && 1399 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1400 if (i != j) 1401 po->rollover->sock = i; 1402 atomic_long_inc(&po->rollover->num); 1403 if (room == ROOM_LOW) 1404 atomic_long_inc(&po->rollover->num_huge); 1405 return i; 1406 } 1407 1408 if (++i == num) 1409 i = 0; 1410 } while (i != j); 1411 1412 atomic_long_inc(&po->rollover->num_failed); 1413 return idx; 1414 } 1415 1416 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1417 struct sk_buff *skb, 1418 unsigned int num) 1419 { 1420 return skb_get_queue_mapping(skb) % num; 1421 } 1422 1423 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1424 struct sk_buff *skb, 1425 unsigned int num) 1426 { 1427 struct bpf_prog *prog; 1428 unsigned int ret = 0; 1429 1430 rcu_read_lock(); 1431 prog = rcu_dereference(f->bpf_prog); 1432 if (prog) 1433 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1434 rcu_read_unlock(); 1435 1436 return ret; 1437 } 1438 1439 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1440 { 1441 return f->flags & (flag >> 8); 1442 } 1443 1444 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1445 struct packet_type *pt, struct net_device *orig_dev) 1446 { 1447 struct packet_fanout *f = pt->af_packet_priv; 1448 unsigned int num = READ_ONCE(f->num_members); 1449 struct net *net = read_pnet(&f->net); 1450 struct packet_sock *po; 1451 unsigned int idx; 1452 1453 if (!net_eq(dev_net(dev), net) || !num) { 1454 kfree_skb(skb); 1455 return 0; 1456 } 1457 1458 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1459 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1460 if (!skb) 1461 return 0; 1462 } 1463 switch (f->type) { 1464 case PACKET_FANOUT_HASH: 1465 default: 1466 idx = fanout_demux_hash(f, skb, num); 1467 break; 1468 case PACKET_FANOUT_LB: 1469 idx = fanout_demux_lb(f, skb, num); 1470 break; 1471 case PACKET_FANOUT_CPU: 1472 idx = fanout_demux_cpu(f, skb, num); 1473 break; 1474 case PACKET_FANOUT_RND: 1475 idx = fanout_demux_rnd(f, skb, num); 1476 break; 1477 case PACKET_FANOUT_QM: 1478 idx = fanout_demux_qm(f, skb, num); 1479 break; 1480 case PACKET_FANOUT_ROLLOVER: 1481 idx = fanout_demux_rollover(f, skb, 0, false, num); 1482 break; 1483 case PACKET_FANOUT_CBPF: 1484 case PACKET_FANOUT_EBPF: 1485 idx = fanout_demux_bpf(f, skb, num); 1486 break; 1487 } 1488 1489 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1490 idx = fanout_demux_rollover(f, skb, idx, true, num); 1491 1492 po = pkt_sk(f->arr[idx]); 1493 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1494 } 1495 1496 DEFINE_MUTEX(fanout_mutex); 1497 EXPORT_SYMBOL_GPL(fanout_mutex); 1498 static LIST_HEAD(fanout_list); 1499 static u16 fanout_next_id; 1500 1501 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1502 { 1503 struct packet_fanout *f = po->fanout; 1504 1505 spin_lock(&f->lock); 1506 f->arr[f->num_members] = sk; 1507 smp_wmb(); 1508 f->num_members++; 1509 if (f->num_members == 1) 1510 dev_add_pack(&f->prot_hook); 1511 spin_unlock(&f->lock); 1512 } 1513 1514 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1515 { 1516 struct packet_fanout *f = po->fanout; 1517 int i; 1518 1519 spin_lock(&f->lock); 1520 for (i = 0; i < f->num_members; i++) { 1521 if (f->arr[i] == sk) 1522 break; 1523 } 1524 BUG_ON(i >= f->num_members); 1525 f->arr[i] = f->arr[f->num_members - 1]; 1526 f->num_members--; 1527 if (f->num_members == 0) 1528 __dev_remove_pack(&f->prot_hook); 1529 spin_unlock(&f->lock); 1530 } 1531 1532 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1533 { 1534 if (sk->sk_family != PF_PACKET) 1535 return false; 1536 1537 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1538 } 1539 1540 static void fanout_init_data(struct packet_fanout *f) 1541 { 1542 switch (f->type) { 1543 case PACKET_FANOUT_LB: 1544 atomic_set(&f->rr_cur, 0); 1545 break; 1546 case PACKET_FANOUT_CBPF: 1547 case PACKET_FANOUT_EBPF: 1548 RCU_INIT_POINTER(f->bpf_prog, NULL); 1549 break; 1550 } 1551 } 1552 1553 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1554 { 1555 struct bpf_prog *old; 1556 1557 spin_lock(&f->lock); 1558 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1559 rcu_assign_pointer(f->bpf_prog, new); 1560 spin_unlock(&f->lock); 1561 1562 if (old) { 1563 synchronize_net(); 1564 bpf_prog_destroy(old); 1565 } 1566 } 1567 1568 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data, 1569 unsigned int len) 1570 { 1571 struct bpf_prog *new; 1572 struct sock_fprog fprog; 1573 int ret; 1574 1575 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1576 return -EPERM; 1577 if (len != sizeof(fprog)) 1578 return -EINVAL; 1579 if (copy_from_user(&fprog, data, len)) 1580 return -EFAULT; 1581 1582 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1583 if (ret) 1584 return ret; 1585 1586 __fanout_set_data_bpf(po->fanout, new); 1587 return 0; 1588 } 1589 1590 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data, 1591 unsigned int len) 1592 { 1593 struct bpf_prog *new; 1594 u32 fd; 1595 1596 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1597 return -EPERM; 1598 if (len != sizeof(fd)) 1599 return -EINVAL; 1600 if (copy_from_user(&fd, data, len)) 1601 return -EFAULT; 1602 1603 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1604 if (IS_ERR(new)) 1605 return PTR_ERR(new); 1606 1607 __fanout_set_data_bpf(po->fanout, new); 1608 return 0; 1609 } 1610 1611 static int fanout_set_data(struct packet_sock *po, char __user *data, 1612 unsigned int len) 1613 { 1614 switch (po->fanout->type) { 1615 case PACKET_FANOUT_CBPF: 1616 return fanout_set_data_cbpf(po, data, len); 1617 case PACKET_FANOUT_EBPF: 1618 return fanout_set_data_ebpf(po, data, len); 1619 default: 1620 return -EINVAL; 1621 }; 1622 } 1623 1624 static void fanout_release_data(struct packet_fanout *f) 1625 { 1626 switch (f->type) { 1627 case PACKET_FANOUT_CBPF: 1628 case PACKET_FANOUT_EBPF: 1629 __fanout_set_data_bpf(f, NULL); 1630 }; 1631 } 1632 1633 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1634 { 1635 struct packet_fanout *f; 1636 1637 list_for_each_entry(f, &fanout_list, list) { 1638 if (f->id == candidate_id && 1639 read_pnet(&f->net) == sock_net(sk)) { 1640 return false; 1641 } 1642 } 1643 return true; 1644 } 1645 1646 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1647 { 1648 u16 id = fanout_next_id; 1649 1650 do { 1651 if (__fanout_id_is_free(sk, id)) { 1652 *new_id = id; 1653 fanout_next_id = id + 1; 1654 return true; 1655 } 1656 1657 id++; 1658 } while (id != fanout_next_id); 1659 1660 return false; 1661 } 1662 1663 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1664 { 1665 struct packet_rollover *rollover = NULL; 1666 struct packet_sock *po = pkt_sk(sk); 1667 struct packet_fanout *f, *match; 1668 u8 type = type_flags & 0xff; 1669 u8 flags = type_flags >> 8; 1670 int err; 1671 1672 switch (type) { 1673 case PACKET_FANOUT_ROLLOVER: 1674 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1675 return -EINVAL; 1676 case PACKET_FANOUT_HASH: 1677 case PACKET_FANOUT_LB: 1678 case PACKET_FANOUT_CPU: 1679 case PACKET_FANOUT_RND: 1680 case PACKET_FANOUT_QM: 1681 case PACKET_FANOUT_CBPF: 1682 case PACKET_FANOUT_EBPF: 1683 break; 1684 default: 1685 return -EINVAL; 1686 } 1687 1688 mutex_lock(&fanout_mutex); 1689 1690 err = -EINVAL; 1691 if (!po->running) 1692 goto out; 1693 1694 err = -EALREADY; 1695 if (po->fanout) 1696 goto out; 1697 1698 if (type == PACKET_FANOUT_ROLLOVER || 1699 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1700 err = -ENOMEM; 1701 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); 1702 if (!rollover) 1703 goto out; 1704 atomic_long_set(&rollover->num, 0); 1705 atomic_long_set(&rollover->num_huge, 0); 1706 atomic_long_set(&rollover->num_failed, 0); 1707 po->rollover = rollover; 1708 } 1709 1710 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1711 if (id != 0) { 1712 err = -EINVAL; 1713 goto out; 1714 } 1715 if (!fanout_find_new_id(sk, &id)) { 1716 err = -ENOMEM; 1717 goto out; 1718 } 1719 /* ephemeral flag for the first socket in the group: drop it */ 1720 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1721 } 1722 1723 match = NULL; 1724 list_for_each_entry(f, &fanout_list, list) { 1725 if (f->id == id && 1726 read_pnet(&f->net) == sock_net(sk)) { 1727 match = f; 1728 break; 1729 } 1730 } 1731 err = -EINVAL; 1732 if (match && match->flags != flags) 1733 goto out; 1734 if (!match) { 1735 err = -ENOMEM; 1736 match = kzalloc(sizeof(*match), GFP_KERNEL); 1737 if (!match) 1738 goto out; 1739 write_pnet(&match->net, sock_net(sk)); 1740 match->id = id; 1741 match->type = type; 1742 match->flags = flags; 1743 INIT_LIST_HEAD(&match->list); 1744 spin_lock_init(&match->lock); 1745 atomic_set(&match->sk_ref, 0); 1746 fanout_init_data(match); 1747 match->prot_hook.type = po->prot_hook.type; 1748 match->prot_hook.dev = po->prot_hook.dev; 1749 match->prot_hook.func = packet_rcv_fanout; 1750 match->prot_hook.af_packet_priv = match; 1751 match->prot_hook.id_match = match_fanout_group; 1752 list_add(&match->list, &fanout_list); 1753 } 1754 err = -EINVAL; 1755 if (match->type == type && 1756 match->prot_hook.type == po->prot_hook.type && 1757 match->prot_hook.dev == po->prot_hook.dev) { 1758 err = -ENOSPC; 1759 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1760 __dev_remove_pack(&po->prot_hook); 1761 po->fanout = match; 1762 atomic_inc(&match->sk_ref); 1763 __fanout_link(sk, po); 1764 err = 0; 1765 } 1766 } 1767 out: 1768 if (err && rollover) { 1769 kfree(rollover); 1770 po->rollover = NULL; 1771 } 1772 mutex_unlock(&fanout_mutex); 1773 return err; 1774 } 1775 1776 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1777 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1778 * It is the responsibility of the caller to call fanout_release_data() and 1779 * free the returned packet_fanout (after synchronize_net()) 1780 */ 1781 static struct packet_fanout *fanout_release(struct sock *sk) 1782 { 1783 struct packet_sock *po = pkt_sk(sk); 1784 struct packet_fanout *f; 1785 1786 mutex_lock(&fanout_mutex); 1787 f = po->fanout; 1788 if (f) { 1789 po->fanout = NULL; 1790 1791 if (atomic_dec_and_test(&f->sk_ref)) 1792 list_del(&f->list); 1793 else 1794 f = NULL; 1795 1796 if (po->rollover) 1797 kfree_rcu(po->rollover, rcu); 1798 } 1799 mutex_unlock(&fanout_mutex); 1800 1801 return f; 1802 } 1803 1804 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1805 struct sk_buff *skb) 1806 { 1807 /* Earlier code assumed this would be a VLAN pkt, double-check 1808 * this now that we have the actual packet in hand. We can only 1809 * do this check on Ethernet devices. 1810 */ 1811 if (unlikely(dev->type != ARPHRD_ETHER)) 1812 return false; 1813 1814 skb_reset_mac_header(skb); 1815 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1816 } 1817 1818 static const struct proto_ops packet_ops; 1819 1820 static const struct proto_ops packet_ops_spkt; 1821 1822 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1823 struct packet_type *pt, struct net_device *orig_dev) 1824 { 1825 struct sock *sk; 1826 struct sockaddr_pkt *spkt; 1827 1828 /* 1829 * When we registered the protocol we saved the socket in the data 1830 * field for just this event. 1831 */ 1832 1833 sk = pt->af_packet_priv; 1834 1835 /* 1836 * Yank back the headers [hope the device set this 1837 * right or kerboom...] 1838 * 1839 * Incoming packets have ll header pulled, 1840 * push it back. 1841 * 1842 * For outgoing ones skb->data == skb_mac_header(skb) 1843 * so that this procedure is noop. 1844 */ 1845 1846 if (skb->pkt_type == PACKET_LOOPBACK) 1847 goto out; 1848 1849 if (!net_eq(dev_net(dev), sock_net(sk))) 1850 goto out; 1851 1852 skb = skb_share_check(skb, GFP_ATOMIC); 1853 if (skb == NULL) 1854 goto oom; 1855 1856 /* drop any routing info */ 1857 skb_dst_drop(skb); 1858 1859 /* drop conntrack reference */ 1860 nf_reset(skb); 1861 1862 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1863 1864 skb_push(skb, skb->data - skb_mac_header(skb)); 1865 1866 /* 1867 * The SOCK_PACKET socket receives _all_ frames. 1868 */ 1869 1870 spkt->spkt_family = dev->type; 1871 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1872 spkt->spkt_protocol = skb->protocol; 1873 1874 /* 1875 * Charge the memory to the socket. This is done specifically 1876 * to prevent sockets using all the memory up. 1877 */ 1878 1879 if (sock_queue_rcv_skb(sk, skb) == 0) 1880 return 0; 1881 1882 out: 1883 kfree_skb(skb); 1884 oom: 1885 return 0; 1886 } 1887 1888 1889 /* 1890 * Output a raw packet to a device layer. This bypasses all the other 1891 * protocol layers and you must therefore supply it with a complete frame 1892 */ 1893 1894 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1895 size_t len) 1896 { 1897 struct sock *sk = sock->sk; 1898 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1899 struct sk_buff *skb = NULL; 1900 struct net_device *dev; 1901 struct sockcm_cookie sockc; 1902 __be16 proto = 0; 1903 int err; 1904 int extra_len = 0; 1905 1906 /* 1907 * Get and verify the address. 1908 */ 1909 1910 if (saddr) { 1911 if (msg->msg_namelen < sizeof(struct sockaddr)) 1912 return -EINVAL; 1913 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1914 proto = saddr->spkt_protocol; 1915 } else 1916 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1917 1918 /* 1919 * Find the device first to size check it 1920 */ 1921 1922 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1923 retry: 1924 rcu_read_lock(); 1925 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1926 err = -ENODEV; 1927 if (dev == NULL) 1928 goto out_unlock; 1929 1930 err = -ENETDOWN; 1931 if (!(dev->flags & IFF_UP)) 1932 goto out_unlock; 1933 1934 /* 1935 * You may not queue a frame bigger than the mtu. This is the lowest level 1936 * raw protocol and you must do your own fragmentation at this level. 1937 */ 1938 1939 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1940 if (!netif_supports_nofcs(dev)) { 1941 err = -EPROTONOSUPPORT; 1942 goto out_unlock; 1943 } 1944 extra_len = 4; /* We're doing our own CRC */ 1945 } 1946 1947 err = -EMSGSIZE; 1948 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1949 goto out_unlock; 1950 1951 if (!skb) { 1952 size_t reserved = LL_RESERVED_SPACE(dev); 1953 int tlen = dev->needed_tailroom; 1954 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1955 1956 rcu_read_unlock(); 1957 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1958 if (skb == NULL) 1959 return -ENOBUFS; 1960 /* FIXME: Save some space for broken drivers that write a hard 1961 * header at transmission time by themselves. PPP is the notable 1962 * one here. This should really be fixed at the driver level. 1963 */ 1964 skb_reserve(skb, reserved); 1965 skb_reset_network_header(skb); 1966 1967 /* Try to align data part correctly */ 1968 if (hhlen) { 1969 skb->data -= hhlen; 1970 skb->tail -= hhlen; 1971 if (len < hhlen) 1972 skb_reset_network_header(skb); 1973 } 1974 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1975 if (err) 1976 goto out_free; 1977 goto retry; 1978 } 1979 1980 if (!dev_validate_header(dev, skb->data, len)) { 1981 err = -EINVAL; 1982 goto out_unlock; 1983 } 1984 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 1985 !packet_extra_vlan_len_allowed(dev, skb)) { 1986 err = -EMSGSIZE; 1987 goto out_unlock; 1988 } 1989 1990 sockc.tsflags = sk->sk_tsflags; 1991 if (msg->msg_controllen) { 1992 err = sock_cmsg_send(sk, msg, &sockc); 1993 if (unlikely(err)) 1994 goto out_unlock; 1995 } 1996 1997 skb->protocol = proto; 1998 skb->dev = dev; 1999 skb->priority = sk->sk_priority; 2000 skb->mark = sk->sk_mark; 2001 2002 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags); 2003 2004 if (unlikely(extra_len == 4)) 2005 skb->no_fcs = 1; 2006 2007 skb_probe_transport_header(skb, 0); 2008 2009 dev_queue_xmit(skb); 2010 rcu_read_unlock(); 2011 return len; 2012 2013 out_unlock: 2014 rcu_read_unlock(); 2015 out_free: 2016 kfree_skb(skb); 2017 return err; 2018 } 2019 2020 static unsigned int run_filter(struct sk_buff *skb, 2021 const struct sock *sk, 2022 unsigned int res) 2023 { 2024 struct sk_filter *filter; 2025 2026 rcu_read_lock(); 2027 filter = rcu_dereference(sk->sk_filter); 2028 if (filter != NULL) 2029 res = bpf_prog_run_clear_cb(filter->prog, skb); 2030 rcu_read_unlock(); 2031 2032 return res; 2033 } 2034 2035 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2036 size_t *len) 2037 { 2038 struct virtio_net_hdr vnet_hdr; 2039 2040 if (*len < sizeof(vnet_hdr)) 2041 return -EINVAL; 2042 *len -= sizeof(vnet_hdr); 2043 2044 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true)) 2045 return -EINVAL; 2046 2047 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr)); 2048 } 2049 2050 /* 2051 * This function makes lazy skb cloning in hope that most of packets 2052 * are discarded by BPF. 2053 * 2054 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2055 * and skb->cb are mangled. It works because (and until) packets 2056 * falling here are owned by current CPU. Output packets are cloned 2057 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2058 * sequencially, so that if we return skb to original state on exit, 2059 * we will not harm anyone. 2060 */ 2061 2062 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2063 struct packet_type *pt, struct net_device *orig_dev) 2064 { 2065 struct sock *sk; 2066 struct sockaddr_ll *sll; 2067 struct packet_sock *po; 2068 u8 *skb_head = skb->data; 2069 int skb_len = skb->len; 2070 unsigned int snaplen, res; 2071 bool is_drop_n_account = false; 2072 2073 if (skb->pkt_type == PACKET_LOOPBACK) 2074 goto drop; 2075 2076 sk = pt->af_packet_priv; 2077 po = pkt_sk(sk); 2078 2079 if (!net_eq(dev_net(dev), sock_net(sk))) 2080 goto drop; 2081 2082 skb->dev = dev; 2083 2084 if (dev->header_ops) { 2085 /* The device has an explicit notion of ll header, 2086 * exported to higher levels. 2087 * 2088 * Otherwise, the device hides details of its frame 2089 * structure, so that corresponding packet head is 2090 * never delivered to user. 2091 */ 2092 if (sk->sk_type != SOCK_DGRAM) 2093 skb_push(skb, skb->data - skb_mac_header(skb)); 2094 else if (skb->pkt_type == PACKET_OUTGOING) { 2095 /* Special case: outgoing packets have ll header at head */ 2096 skb_pull(skb, skb_network_offset(skb)); 2097 } 2098 } 2099 2100 snaplen = skb->len; 2101 2102 res = run_filter(skb, sk, snaplen); 2103 if (!res) 2104 goto drop_n_restore; 2105 if (snaplen > res) 2106 snaplen = res; 2107 2108 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2109 goto drop_n_acct; 2110 2111 if (skb_shared(skb)) { 2112 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2113 if (nskb == NULL) 2114 goto drop_n_acct; 2115 2116 if (skb_head != skb->data) { 2117 skb->data = skb_head; 2118 skb->len = skb_len; 2119 } 2120 consume_skb(skb); 2121 skb = nskb; 2122 } 2123 2124 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2125 2126 sll = &PACKET_SKB_CB(skb)->sa.ll; 2127 sll->sll_hatype = dev->type; 2128 sll->sll_pkttype = skb->pkt_type; 2129 if (unlikely(po->origdev)) 2130 sll->sll_ifindex = orig_dev->ifindex; 2131 else 2132 sll->sll_ifindex = dev->ifindex; 2133 2134 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2135 2136 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2137 * Use their space for storing the original skb length. 2138 */ 2139 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2140 2141 if (pskb_trim(skb, snaplen)) 2142 goto drop_n_acct; 2143 2144 skb_set_owner_r(skb, sk); 2145 skb->dev = NULL; 2146 skb_dst_drop(skb); 2147 2148 /* drop conntrack reference */ 2149 nf_reset(skb); 2150 2151 spin_lock(&sk->sk_receive_queue.lock); 2152 po->stats.stats1.tp_packets++; 2153 sock_skb_set_dropcount(sk, skb); 2154 __skb_queue_tail(&sk->sk_receive_queue, skb); 2155 spin_unlock(&sk->sk_receive_queue.lock); 2156 sk->sk_data_ready(sk); 2157 return 0; 2158 2159 drop_n_acct: 2160 is_drop_n_account = true; 2161 spin_lock(&sk->sk_receive_queue.lock); 2162 po->stats.stats1.tp_drops++; 2163 atomic_inc(&sk->sk_drops); 2164 spin_unlock(&sk->sk_receive_queue.lock); 2165 2166 drop_n_restore: 2167 if (skb_head != skb->data && skb_shared(skb)) { 2168 skb->data = skb_head; 2169 skb->len = skb_len; 2170 } 2171 drop: 2172 if (!is_drop_n_account) 2173 consume_skb(skb); 2174 else 2175 kfree_skb(skb); 2176 return 0; 2177 } 2178 2179 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2180 struct packet_type *pt, struct net_device *orig_dev) 2181 { 2182 struct sock *sk; 2183 struct packet_sock *po; 2184 struct sockaddr_ll *sll; 2185 union tpacket_uhdr h; 2186 u8 *skb_head = skb->data; 2187 int skb_len = skb->len; 2188 unsigned int snaplen, res; 2189 unsigned long status = TP_STATUS_USER; 2190 unsigned short macoff, netoff, hdrlen; 2191 struct sk_buff *copy_skb = NULL; 2192 struct timespec ts; 2193 __u32 ts_status; 2194 bool is_drop_n_account = false; 2195 2196 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2197 * We may add members to them until current aligned size without forcing 2198 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2199 */ 2200 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2201 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2202 2203 if (skb->pkt_type == PACKET_LOOPBACK) 2204 goto drop; 2205 2206 sk = pt->af_packet_priv; 2207 po = pkt_sk(sk); 2208 2209 if (!net_eq(dev_net(dev), sock_net(sk))) 2210 goto drop; 2211 2212 if (dev->header_ops) { 2213 if (sk->sk_type != SOCK_DGRAM) 2214 skb_push(skb, skb->data - skb_mac_header(skb)); 2215 else if (skb->pkt_type == PACKET_OUTGOING) { 2216 /* Special case: outgoing packets have ll header at head */ 2217 skb_pull(skb, skb_network_offset(skb)); 2218 } 2219 } 2220 2221 snaplen = skb->len; 2222 2223 res = run_filter(skb, sk, snaplen); 2224 if (!res) 2225 goto drop_n_restore; 2226 2227 if (skb->ip_summed == CHECKSUM_PARTIAL) 2228 status |= TP_STATUS_CSUMNOTREADY; 2229 else if (skb->pkt_type != PACKET_OUTGOING && 2230 (skb->ip_summed == CHECKSUM_COMPLETE || 2231 skb_csum_unnecessary(skb))) 2232 status |= TP_STATUS_CSUM_VALID; 2233 2234 if (snaplen > res) 2235 snaplen = res; 2236 2237 if (sk->sk_type == SOCK_DGRAM) { 2238 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2239 po->tp_reserve; 2240 } else { 2241 unsigned int maclen = skb_network_offset(skb); 2242 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2243 (maclen < 16 ? 16 : maclen)) + 2244 po->tp_reserve; 2245 if (po->has_vnet_hdr) 2246 netoff += sizeof(struct virtio_net_hdr); 2247 macoff = netoff - maclen; 2248 } 2249 if (po->tp_version <= TPACKET_V2) { 2250 if (macoff + snaplen > po->rx_ring.frame_size) { 2251 if (po->copy_thresh && 2252 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2253 if (skb_shared(skb)) { 2254 copy_skb = skb_clone(skb, GFP_ATOMIC); 2255 } else { 2256 copy_skb = skb_get(skb); 2257 skb_head = skb->data; 2258 } 2259 if (copy_skb) 2260 skb_set_owner_r(copy_skb, sk); 2261 } 2262 snaplen = po->rx_ring.frame_size - macoff; 2263 if ((int)snaplen < 0) 2264 snaplen = 0; 2265 } 2266 } else if (unlikely(macoff + snaplen > 2267 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2268 u32 nval; 2269 2270 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2271 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2272 snaplen, nval, macoff); 2273 snaplen = nval; 2274 if (unlikely((int)snaplen < 0)) { 2275 snaplen = 0; 2276 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2277 } 2278 } 2279 spin_lock(&sk->sk_receive_queue.lock); 2280 h.raw = packet_current_rx_frame(po, skb, 2281 TP_STATUS_KERNEL, (macoff+snaplen)); 2282 if (!h.raw) 2283 goto drop_n_account; 2284 if (po->tp_version <= TPACKET_V2) { 2285 packet_increment_rx_head(po, &po->rx_ring); 2286 /* 2287 * LOSING will be reported till you read the stats, 2288 * because it's COR - Clear On Read. 2289 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2290 * at packet level. 2291 */ 2292 if (po->stats.stats1.tp_drops) 2293 status |= TP_STATUS_LOSING; 2294 } 2295 po->stats.stats1.tp_packets++; 2296 if (copy_skb) { 2297 status |= TP_STATUS_COPY; 2298 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2299 } 2300 spin_unlock(&sk->sk_receive_queue.lock); 2301 2302 if (po->has_vnet_hdr) { 2303 if (virtio_net_hdr_from_skb(skb, h.raw + macoff - 2304 sizeof(struct virtio_net_hdr), 2305 vio_le(), true)) { 2306 spin_lock(&sk->sk_receive_queue.lock); 2307 goto drop_n_account; 2308 } 2309 } 2310 2311 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2312 2313 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 2314 getnstimeofday(&ts); 2315 2316 status |= ts_status; 2317 2318 switch (po->tp_version) { 2319 case TPACKET_V1: 2320 h.h1->tp_len = skb->len; 2321 h.h1->tp_snaplen = snaplen; 2322 h.h1->tp_mac = macoff; 2323 h.h1->tp_net = netoff; 2324 h.h1->tp_sec = ts.tv_sec; 2325 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2326 hdrlen = sizeof(*h.h1); 2327 break; 2328 case TPACKET_V2: 2329 h.h2->tp_len = skb->len; 2330 h.h2->tp_snaplen = snaplen; 2331 h.h2->tp_mac = macoff; 2332 h.h2->tp_net = netoff; 2333 h.h2->tp_sec = ts.tv_sec; 2334 h.h2->tp_nsec = ts.tv_nsec; 2335 if (skb_vlan_tag_present(skb)) { 2336 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2337 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2338 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2339 } else { 2340 h.h2->tp_vlan_tci = 0; 2341 h.h2->tp_vlan_tpid = 0; 2342 } 2343 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2344 hdrlen = sizeof(*h.h2); 2345 break; 2346 case TPACKET_V3: 2347 /* tp_nxt_offset,vlan are already populated above. 2348 * So DONT clear those fields here 2349 */ 2350 h.h3->tp_status |= status; 2351 h.h3->tp_len = skb->len; 2352 h.h3->tp_snaplen = snaplen; 2353 h.h3->tp_mac = macoff; 2354 h.h3->tp_net = netoff; 2355 h.h3->tp_sec = ts.tv_sec; 2356 h.h3->tp_nsec = ts.tv_nsec; 2357 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2358 hdrlen = sizeof(*h.h3); 2359 break; 2360 default: 2361 BUG(); 2362 } 2363 2364 sll = h.raw + TPACKET_ALIGN(hdrlen); 2365 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2366 sll->sll_family = AF_PACKET; 2367 sll->sll_hatype = dev->type; 2368 sll->sll_protocol = skb->protocol; 2369 sll->sll_pkttype = skb->pkt_type; 2370 if (unlikely(po->origdev)) 2371 sll->sll_ifindex = orig_dev->ifindex; 2372 else 2373 sll->sll_ifindex = dev->ifindex; 2374 2375 smp_mb(); 2376 2377 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2378 if (po->tp_version <= TPACKET_V2) { 2379 u8 *start, *end; 2380 2381 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2382 macoff + snaplen); 2383 2384 for (start = h.raw; start < end; start += PAGE_SIZE) 2385 flush_dcache_page(pgv_to_page(start)); 2386 } 2387 smp_wmb(); 2388 #endif 2389 2390 if (po->tp_version <= TPACKET_V2) { 2391 __packet_set_status(po, h.raw, status); 2392 sk->sk_data_ready(sk); 2393 } else { 2394 prb_clear_blk_fill_status(&po->rx_ring); 2395 } 2396 2397 drop_n_restore: 2398 if (skb_head != skb->data && skb_shared(skb)) { 2399 skb->data = skb_head; 2400 skb->len = skb_len; 2401 } 2402 drop: 2403 if (!is_drop_n_account) 2404 consume_skb(skb); 2405 else 2406 kfree_skb(skb); 2407 return 0; 2408 2409 drop_n_account: 2410 is_drop_n_account = true; 2411 po->stats.stats1.tp_drops++; 2412 spin_unlock(&sk->sk_receive_queue.lock); 2413 2414 sk->sk_data_ready(sk); 2415 kfree_skb(copy_skb); 2416 goto drop_n_restore; 2417 } 2418 2419 static void tpacket_destruct_skb(struct sk_buff *skb) 2420 { 2421 struct packet_sock *po = pkt_sk(skb->sk); 2422 2423 if (likely(po->tx_ring.pg_vec)) { 2424 void *ph; 2425 __u32 ts; 2426 2427 ph = skb_shinfo(skb)->destructor_arg; 2428 packet_dec_pending(&po->tx_ring); 2429 2430 ts = __packet_set_timestamp(po, ph, skb); 2431 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2432 } 2433 2434 sock_wfree(skb); 2435 } 2436 2437 static void tpacket_set_protocol(const struct net_device *dev, 2438 struct sk_buff *skb) 2439 { 2440 if (dev->type == ARPHRD_ETHER) { 2441 skb_reset_mac_header(skb); 2442 skb->protocol = eth_hdr(skb)->h_proto; 2443 } 2444 } 2445 2446 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2447 { 2448 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2449 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2450 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2451 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2452 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2453 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2454 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2455 2456 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2457 return -EINVAL; 2458 2459 return 0; 2460 } 2461 2462 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2463 struct virtio_net_hdr *vnet_hdr) 2464 { 2465 if (*len < sizeof(*vnet_hdr)) 2466 return -EINVAL; 2467 *len -= sizeof(*vnet_hdr); 2468 2469 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2470 return -EFAULT; 2471 2472 return __packet_snd_vnet_parse(vnet_hdr, *len); 2473 } 2474 2475 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2476 void *frame, struct net_device *dev, void *data, int tp_len, 2477 __be16 proto, unsigned char *addr, int hlen, int copylen, 2478 const struct sockcm_cookie *sockc) 2479 { 2480 union tpacket_uhdr ph; 2481 int to_write, offset, len, nr_frags, len_max; 2482 struct socket *sock = po->sk.sk_socket; 2483 struct page *page; 2484 int err; 2485 2486 ph.raw = frame; 2487 2488 skb->protocol = proto; 2489 skb->dev = dev; 2490 skb->priority = po->sk.sk_priority; 2491 skb->mark = po->sk.sk_mark; 2492 sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags); 2493 skb_shinfo(skb)->destructor_arg = ph.raw; 2494 2495 skb_reserve(skb, hlen); 2496 skb_reset_network_header(skb); 2497 2498 to_write = tp_len; 2499 2500 if (sock->type == SOCK_DGRAM) { 2501 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2502 NULL, tp_len); 2503 if (unlikely(err < 0)) 2504 return -EINVAL; 2505 } else if (copylen) { 2506 int hdrlen = min_t(int, copylen, tp_len); 2507 2508 skb_push(skb, dev->hard_header_len); 2509 skb_put(skb, copylen - dev->hard_header_len); 2510 err = skb_store_bits(skb, 0, data, hdrlen); 2511 if (unlikely(err)) 2512 return err; 2513 if (!dev_validate_header(dev, skb->data, hdrlen)) 2514 return -EINVAL; 2515 if (!skb->protocol) 2516 tpacket_set_protocol(dev, skb); 2517 2518 data += hdrlen; 2519 to_write -= hdrlen; 2520 } 2521 2522 offset = offset_in_page(data); 2523 len_max = PAGE_SIZE - offset; 2524 len = ((to_write > len_max) ? len_max : to_write); 2525 2526 skb->data_len = to_write; 2527 skb->len += to_write; 2528 skb->truesize += to_write; 2529 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2530 2531 while (likely(to_write)) { 2532 nr_frags = skb_shinfo(skb)->nr_frags; 2533 2534 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2535 pr_err("Packet exceed the number of skb frags(%lu)\n", 2536 MAX_SKB_FRAGS); 2537 return -EFAULT; 2538 } 2539 2540 page = pgv_to_page(data); 2541 data += len; 2542 flush_dcache_page(page); 2543 get_page(page); 2544 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2545 to_write -= len; 2546 offset = 0; 2547 len_max = PAGE_SIZE; 2548 len = ((to_write > len_max) ? len_max : to_write); 2549 } 2550 2551 skb_probe_transport_header(skb, 0); 2552 2553 return tp_len; 2554 } 2555 2556 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2557 int size_max, void **data) 2558 { 2559 union tpacket_uhdr ph; 2560 int tp_len, off; 2561 2562 ph.raw = frame; 2563 2564 switch (po->tp_version) { 2565 case TPACKET_V3: 2566 if (ph.h3->tp_next_offset != 0) { 2567 pr_warn_once("variable sized slot not supported"); 2568 return -EINVAL; 2569 } 2570 tp_len = ph.h3->tp_len; 2571 break; 2572 case TPACKET_V2: 2573 tp_len = ph.h2->tp_len; 2574 break; 2575 default: 2576 tp_len = ph.h1->tp_len; 2577 break; 2578 } 2579 if (unlikely(tp_len > size_max)) { 2580 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2581 return -EMSGSIZE; 2582 } 2583 2584 if (unlikely(po->tp_tx_has_off)) { 2585 int off_min, off_max; 2586 2587 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2588 off_max = po->tx_ring.frame_size - tp_len; 2589 if (po->sk.sk_type == SOCK_DGRAM) { 2590 switch (po->tp_version) { 2591 case TPACKET_V3: 2592 off = ph.h3->tp_net; 2593 break; 2594 case TPACKET_V2: 2595 off = ph.h2->tp_net; 2596 break; 2597 default: 2598 off = ph.h1->tp_net; 2599 break; 2600 } 2601 } else { 2602 switch (po->tp_version) { 2603 case TPACKET_V3: 2604 off = ph.h3->tp_mac; 2605 break; 2606 case TPACKET_V2: 2607 off = ph.h2->tp_mac; 2608 break; 2609 default: 2610 off = ph.h1->tp_mac; 2611 break; 2612 } 2613 } 2614 if (unlikely((off < off_min) || (off_max < off))) 2615 return -EINVAL; 2616 } else { 2617 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2618 } 2619 2620 *data = frame + off; 2621 return tp_len; 2622 } 2623 2624 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2625 { 2626 struct sk_buff *skb; 2627 struct net_device *dev; 2628 struct virtio_net_hdr *vnet_hdr = NULL; 2629 struct sockcm_cookie sockc; 2630 __be16 proto; 2631 int err, reserve = 0; 2632 void *ph; 2633 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2634 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2635 int tp_len, size_max; 2636 unsigned char *addr; 2637 void *data; 2638 int len_sum = 0; 2639 int status = TP_STATUS_AVAILABLE; 2640 int hlen, tlen, copylen = 0; 2641 2642 mutex_lock(&po->pg_vec_lock); 2643 2644 if (likely(saddr == NULL)) { 2645 dev = packet_cached_dev_get(po); 2646 proto = po->num; 2647 addr = NULL; 2648 } else { 2649 err = -EINVAL; 2650 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2651 goto out; 2652 if (msg->msg_namelen < (saddr->sll_halen 2653 + offsetof(struct sockaddr_ll, 2654 sll_addr))) 2655 goto out; 2656 proto = saddr->sll_protocol; 2657 addr = saddr->sll_addr; 2658 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2659 } 2660 2661 sockc.tsflags = po->sk.sk_tsflags; 2662 if (msg->msg_controllen) { 2663 err = sock_cmsg_send(&po->sk, msg, &sockc); 2664 if (unlikely(err)) 2665 goto out; 2666 } 2667 2668 err = -ENXIO; 2669 if (unlikely(dev == NULL)) 2670 goto out; 2671 err = -ENETDOWN; 2672 if (unlikely(!(dev->flags & IFF_UP))) 2673 goto out_put; 2674 2675 if (po->sk.sk_socket->type == SOCK_RAW) 2676 reserve = dev->hard_header_len; 2677 size_max = po->tx_ring.frame_size 2678 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2679 2680 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr) 2681 size_max = dev->mtu + reserve + VLAN_HLEN; 2682 2683 do { 2684 ph = packet_current_frame(po, &po->tx_ring, 2685 TP_STATUS_SEND_REQUEST); 2686 if (unlikely(ph == NULL)) { 2687 if (need_wait && need_resched()) 2688 schedule(); 2689 continue; 2690 } 2691 2692 skb = NULL; 2693 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2694 if (tp_len < 0) 2695 goto tpacket_error; 2696 2697 status = TP_STATUS_SEND_REQUEST; 2698 hlen = LL_RESERVED_SPACE(dev); 2699 tlen = dev->needed_tailroom; 2700 if (po->has_vnet_hdr) { 2701 vnet_hdr = data; 2702 data += sizeof(*vnet_hdr); 2703 tp_len -= sizeof(*vnet_hdr); 2704 if (tp_len < 0 || 2705 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2706 tp_len = -EINVAL; 2707 goto tpacket_error; 2708 } 2709 copylen = __virtio16_to_cpu(vio_le(), 2710 vnet_hdr->hdr_len); 2711 } 2712 copylen = max_t(int, copylen, dev->hard_header_len); 2713 skb = sock_alloc_send_skb(&po->sk, 2714 hlen + tlen + sizeof(struct sockaddr_ll) + 2715 (copylen - dev->hard_header_len), 2716 !need_wait, &err); 2717 2718 if (unlikely(skb == NULL)) { 2719 /* we assume the socket was initially writeable ... */ 2720 if (likely(len_sum > 0)) 2721 err = len_sum; 2722 goto out_status; 2723 } 2724 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2725 addr, hlen, copylen, &sockc); 2726 if (likely(tp_len >= 0) && 2727 tp_len > dev->mtu + reserve && 2728 !po->has_vnet_hdr && 2729 !packet_extra_vlan_len_allowed(dev, skb)) 2730 tp_len = -EMSGSIZE; 2731 2732 if (unlikely(tp_len < 0)) { 2733 tpacket_error: 2734 if (po->tp_loss) { 2735 __packet_set_status(po, ph, 2736 TP_STATUS_AVAILABLE); 2737 packet_increment_head(&po->tx_ring); 2738 kfree_skb(skb); 2739 continue; 2740 } else { 2741 status = TP_STATUS_WRONG_FORMAT; 2742 err = tp_len; 2743 goto out_status; 2744 } 2745 } 2746 2747 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr, 2748 vio_le())) { 2749 tp_len = -EINVAL; 2750 goto tpacket_error; 2751 } 2752 2753 packet_pick_tx_queue(dev, skb); 2754 2755 skb->destructor = tpacket_destruct_skb; 2756 __packet_set_status(po, ph, TP_STATUS_SENDING); 2757 packet_inc_pending(&po->tx_ring); 2758 2759 status = TP_STATUS_SEND_REQUEST; 2760 err = po->xmit(skb); 2761 if (unlikely(err > 0)) { 2762 err = net_xmit_errno(err); 2763 if (err && __packet_get_status(po, ph) == 2764 TP_STATUS_AVAILABLE) { 2765 /* skb was destructed already */ 2766 skb = NULL; 2767 goto out_status; 2768 } 2769 /* 2770 * skb was dropped but not destructed yet; 2771 * let's treat it like congestion or err < 0 2772 */ 2773 err = 0; 2774 } 2775 packet_increment_head(&po->tx_ring); 2776 len_sum += tp_len; 2777 } while (likely((ph != NULL) || 2778 /* Note: packet_read_pending() might be slow if we have 2779 * to call it as it's per_cpu variable, but in fast-path 2780 * we already short-circuit the loop with the first 2781 * condition, and luckily don't have to go that path 2782 * anyway. 2783 */ 2784 (need_wait && packet_read_pending(&po->tx_ring)))); 2785 2786 err = len_sum; 2787 goto out_put; 2788 2789 out_status: 2790 __packet_set_status(po, ph, status); 2791 kfree_skb(skb); 2792 out_put: 2793 dev_put(dev); 2794 out: 2795 mutex_unlock(&po->pg_vec_lock); 2796 return err; 2797 } 2798 2799 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2800 size_t reserve, size_t len, 2801 size_t linear, int noblock, 2802 int *err) 2803 { 2804 struct sk_buff *skb; 2805 2806 /* Under a page? Don't bother with paged skb. */ 2807 if (prepad + len < PAGE_SIZE || !linear) 2808 linear = len; 2809 2810 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2811 err, 0); 2812 if (!skb) 2813 return NULL; 2814 2815 skb_reserve(skb, reserve); 2816 skb_put(skb, linear); 2817 skb->data_len = len - linear; 2818 skb->len += len - linear; 2819 2820 return skb; 2821 } 2822 2823 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2824 { 2825 struct sock *sk = sock->sk; 2826 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2827 struct sk_buff *skb; 2828 struct net_device *dev; 2829 __be16 proto; 2830 unsigned char *addr; 2831 int err, reserve = 0; 2832 struct sockcm_cookie sockc; 2833 struct virtio_net_hdr vnet_hdr = { 0 }; 2834 int offset = 0; 2835 struct packet_sock *po = pkt_sk(sk); 2836 int hlen, tlen, linear; 2837 int extra_len = 0; 2838 2839 /* 2840 * Get and verify the address. 2841 */ 2842 2843 if (likely(saddr == NULL)) { 2844 dev = packet_cached_dev_get(po); 2845 proto = po->num; 2846 addr = NULL; 2847 } else { 2848 err = -EINVAL; 2849 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2850 goto out; 2851 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2852 goto out; 2853 proto = saddr->sll_protocol; 2854 addr = saddr->sll_addr; 2855 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2856 } 2857 2858 err = -ENXIO; 2859 if (unlikely(dev == NULL)) 2860 goto out_unlock; 2861 err = -ENETDOWN; 2862 if (unlikely(!(dev->flags & IFF_UP))) 2863 goto out_unlock; 2864 2865 sockc.tsflags = sk->sk_tsflags; 2866 sockc.mark = sk->sk_mark; 2867 if (msg->msg_controllen) { 2868 err = sock_cmsg_send(sk, msg, &sockc); 2869 if (unlikely(err)) 2870 goto out_unlock; 2871 } 2872 2873 if (sock->type == SOCK_RAW) 2874 reserve = dev->hard_header_len; 2875 if (po->has_vnet_hdr) { 2876 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); 2877 if (err) 2878 goto out_unlock; 2879 } 2880 2881 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2882 if (!netif_supports_nofcs(dev)) { 2883 err = -EPROTONOSUPPORT; 2884 goto out_unlock; 2885 } 2886 extra_len = 4; /* We're doing our own CRC */ 2887 } 2888 2889 err = -EMSGSIZE; 2890 if (!vnet_hdr.gso_type && 2891 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2892 goto out_unlock; 2893 2894 err = -ENOBUFS; 2895 hlen = LL_RESERVED_SPACE(dev); 2896 tlen = dev->needed_tailroom; 2897 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 2898 linear = max(linear, min_t(int, len, dev->hard_header_len)); 2899 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 2900 msg->msg_flags & MSG_DONTWAIT, &err); 2901 if (skb == NULL) 2902 goto out_unlock; 2903 2904 skb_set_network_header(skb, reserve); 2905 2906 err = -EINVAL; 2907 if (sock->type == SOCK_DGRAM) { 2908 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2909 if (unlikely(offset < 0)) 2910 goto out_free; 2911 } 2912 2913 /* Returns -EFAULT on error */ 2914 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2915 if (err) 2916 goto out_free; 2917 2918 if (sock->type == SOCK_RAW && 2919 !dev_validate_header(dev, skb->data, len)) { 2920 err = -EINVAL; 2921 goto out_free; 2922 } 2923 2924 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags); 2925 2926 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 2927 !packet_extra_vlan_len_allowed(dev, skb)) { 2928 err = -EMSGSIZE; 2929 goto out_free; 2930 } 2931 2932 skb->protocol = proto; 2933 skb->dev = dev; 2934 skb->priority = sk->sk_priority; 2935 skb->mark = sockc.mark; 2936 2937 packet_pick_tx_queue(dev, skb); 2938 2939 if (po->has_vnet_hdr) { 2940 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 2941 if (err) 2942 goto out_free; 2943 len += sizeof(vnet_hdr); 2944 } 2945 2946 skb_probe_transport_header(skb, reserve); 2947 2948 if (unlikely(extra_len == 4)) 2949 skb->no_fcs = 1; 2950 2951 err = po->xmit(skb); 2952 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2953 goto out_unlock; 2954 2955 dev_put(dev); 2956 2957 return len; 2958 2959 out_free: 2960 kfree_skb(skb); 2961 out_unlock: 2962 if (dev) 2963 dev_put(dev); 2964 out: 2965 return err; 2966 } 2967 2968 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 2969 { 2970 struct sock *sk = sock->sk; 2971 struct packet_sock *po = pkt_sk(sk); 2972 2973 if (po->tx_ring.pg_vec) 2974 return tpacket_snd(po, msg); 2975 else 2976 return packet_snd(sock, msg, len); 2977 } 2978 2979 /* 2980 * Close a PACKET socket. This is fairly simple. We immediately go 2981 * to 'closed' state and remove our protocol entry in the device list. 2982 */ 2983 2984 static int packet_release(struct socket *sock) 2985 { 2986 struct sock *sk = sock->sk; 2987 struct packet_sock *po; 2988 struct packet_fanout *f; 2989 struct net *net; 2990 union tpacket_req_u req_u; 2991 2992 if (!sk) 2993 return 0; 2994 2995 net = sock_net(sk); 2996 po = pkt_sk(sk); 2997 2998 mutex_lock(&net->packet.sklist_lock); 2999 sk_del_node_init_rcu(sk); 3000 mutex_unlock(&net->packet.sklist_lock); 3001 3002 preempt_disable(); 3003 sock_prot_inuse_add(net, sk->sk_prot, -1); 3004 preempt_enable(); 3005 3006 spin_lock(&po->bind_lock); 3007 unregister_prot_hook(sk, false); 3008 packet_cached_dev_reset(po); 3009 3010 if (po->prot_hook.dev) { 3011 dev_put(po->prot_hook.dev); 3012 po->prot_hook.dev = NULL; 3013 } 3014 spin_unlock(&po->bind_lock); 3015 3016 packet_flush_mclist(sk); 3017 3018 if (po->rx_ring.pg_vec) { 3019 memset(&req_u, 0, sizeof(req_u)); 3020 packet_set_ring(sk, &req_u, 1, 0); 3021 } 3022 3023 if (po->tx_ring.pg_vec) { 3024 memset(&req_u, 0, sizeof(req_u)); 3025 packet_set_ring(sk, &req_u, 1, 1); 3026 } 3027 3028 f = fanout_release(sk); 3029 3030 synchronize_net(); 3031 3032 if (f) { 3033 fanout_release_data(f); 3034 kfree(f); 3035 } 3036 /* 3037 * Now the socket is dead. No more input will appear. 3038 */ 3039 sock_orphan(sk); 3040 sock->sk = NULL; 3041 3042 /* Purge queues */ 3043 3044 skb_queue_purge(&sk->sk_receive_queue); 3045 packet_free_pending(po); 3046 sk_refcnt_debug_release(sk); 3047 3048 sock_put(sk); 3049 return 0; 3050 } 3051 3052 /* 3053 * Attach a packet hook. 3054 */ 3055 3056 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3057 __be16 proto) 3058 { 3059 struct packet_sock *po = pkt_sk(sk); 3060 struct net_device *dev_curr; 3061 __be16 proto_curr; 3062 bool need_rehook; 3063 struct net_device *dev = NULL; 3064 int ret = 0; 3065 bool unlisted = false; 3066 3067 if (po->fanout) 3068 return -EINVAL; 3069 3070 lock_sock(sk); 3071 spin_lock(&po->bind_lock); 3072 rcu_read_lock(); 3073 3074 if (name) { 3075 dev = dev_get_by_name_rcu(sock_net(sk), name); 3076 if (!dev) { 3077 ret = -ENODEV; 3078 goto out_unlock; 3079 } 3080 } else if (ifindex) { 3081 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3082 if (!dev) { 3083 ret = -ENODEV; 3084 goto out_unlock; 3085 } 3086 } 3087 3088 if (dev) 3089 dev_hold(dev); 3090 3091 proto_curr = po->prot_hook.type; 3092 dev_curr = po->prot_hook.dev; 3093 3094 need_rehook = proto_curr != proto || dev_curr != dev; 3095 3096 if (need_rehook) { 3097 if (po->running) { 3098 rcu_read_unlock(); 3099 __unregister_prot_hook(sk, true); 3100 rcu_read_lock(); 3101 dev_curr = po->prot_hook.dev; 3102 if (dev) 3103 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3104 dev->ifindex); 3105 } 3106 3107 po->num = proto; 3108 po->prot_hook.type = proto; 3109 3110 if (unlikely(unlisted)) { 3111 dev_put(dev); 3112 po->prot_hook.dev = NULL; 3113 po->ifindex = -1; 3114 packet_cached_dev_reset(po); 3115 } else { 3116 po->prot_hook.dev = dev; 3117 po->ifindex = dev ? dev->ifindex : 0; 3118 packet_cached_dev_assign(po, dev); 3119 } 3120 } 3121 if (dev_curr) 3122 dev_put(dev_curr); 3123 3124 if (proto == 0 || !need_rehook) 3125 goto out_unlock; 3126 3127 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3128 register_prot_hook(sk); 3129 } else { 3130 sk->sk_err = ENETDOWN; 3131 if (!sock_flag(sk, SOCK_DEAD)) 3132 sk->sk_error_report(sk); 3133 } 3134 3135 out_unlock: 3136 rcu_read_unlock(); 3137 spin_unlock(&po->bind_lock); 3138 release_sock(sk); 3139 return ret; 3140 } 3141 3142 /* 3143 * Bind a packet socket to a device 3144 */ 3145 3146 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3147 int addr_len) 3148 { 3149 struct sock *sk = sock->sk; 3150 char name[sizeof(uaddr->sa_data) + 1]; 3151 3152 /* 3153 * Check legality 3154 */ 3155 3156 if (addr_len != sizeof(struct sockaddr)) 3157 return -EINVAL; 3158 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3159 * zero-terminated. 3160 */ 3161 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data)); 3162 name[sizeof(uaddr->sa_data)] = 0; 3163 3164 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); 3165 } 3166 3167 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3168 { 3169 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3170 struct sock *sk = sock->sk; 3171 3172 /* 3173 * Check legality 3174 */ 3175 3176 if (addr_len < sizeof(struct sockaddr_ll)) 3177 return -EINVAL; 3178 if (sll->sll_family != AF_PACKET) 3179 return -EINVAL; 3180 3181 return packet_do_bind(sk, NULL, sll->sll_ifindex, 3182 sll->sll_protocol ? : pkt_sk(sk)->num); 3183 } 3184 3185 static struct proto packet_proto = { 3186 .name = "PACKET", 3187 .owner = THIS_MODULE, 3188 .obj_size = sizeof(struct packet_sock), 3189 }; 3190 3191 /* 3192 * Create a packet of type SOCK_PACKET. 3193 */ 3194 3195 static int packet_create(struct net *net, struct socket *sock, int protocol, 3196 int kern) 3197 { 3198 struct sock *sk; 3199 struct packet_sock *po; 3200 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3201 int err; 3202 3203 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3204 return -EPERM; 3205 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3206 sock->type != SOCK_PACKET) 3207 return -ESOCKTNOSUPPORT; 3208 3209 sock->state = SS_UNCONNECTED; 3210 3211 err = -ENOBUFS; 3212 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3213 if (sk == NULL) 3214 goto out; 3215 3216 sock->ops = &packet_ops; 3217 if (sock->type == SOCK_PACKET) 3218 sock->ops = &packet_ops_spkt; 3219 3220 sock_init_data(sock, sk); 3221 3222 po = pkt_sk(sk); 3223 sk->sk_family = PF_PACKET; 3224 po->num = proto; 3225 po->xmit = dev_queue_xmit; 3226 3227 err = packet_alloc_pending(po); 3228 if (err) 3229 goto out2; 3230 3231 packet_cached_dev_reset(po); 3232 3233 sk->sk_destruct = packet_sock_destruct; 3234 sk_refcnt_debug_inc(sk); 3235 3236 /* 3237 * Attach a protocol block 3238 */ 3239 3240 spin_lock_init(&po->bind_lock); 3241 mutex_init(&po->pg_vec_lock); 3242 po->rollover = NULL; 3243 po->prot_hook.func = packet_rcv; 3244 3245 if (sock->type == SOCK_PACKET) 3246 po->prot_hook.func = packet_rcv_spkt; 3247 3248 po->prot_hook.af_packet_priv = sk; 3249 3250 if (proto) { 3251 po->prot_hook.type = proto; 3252 register_prot_hook(sk); 3253 } 3254 3255 mutex_lock(&net->packet.sklist_lock); 3256 sk_add_node_rcu(sk, &net->packet.sklist); 3257 mutex_unlock(&net->packet.sklist_lock); 3258 3259 preempt_disable(); 3260 sock_prot_inuse_add(net, &packet_proto, 1); 3261 preempt_enable(); 3262 3263 return 0; 3264 out2: 3265 sk_free(sk); 3266 out: 3267 return err; 3268 } 3269 3270 /* 3271 * Pull a packet from our receive queue and hand it to the user. 3272 * If necessary we block. 3273 */ 3274 3275 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3276 int flags) 3277 { 3278 struct sock *sk = sock->sk; 3279 struct sk_buff *skb; 3280 int copied, err; 3281 int vnet_hdr_len = 0; 3282 unsigned int origlen = 0; 3283 3284 err = -EINVAL; 3285 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3286 goto out; 3287 3288 #if 0 3289 /* What error should we return now? EUNATTACH? */ 3290 if (pkt_sk(sk)->ifindex < 0) 3291 return -ENODEV; 3292 #endif 3293 3294 if (flags & MSG_ERRQUEUE) { 3295 err = sock_recv_errqueue(sk, msg, len, 3296 SOL_PACKET, PACKET_TX_TIMESTAMP); 3297 goto out; 3298 } 3299 3300 /* 3301 * Call the generic datagram receiver. This handles all sorts 3302 * of horrible races and re-entrancy so we can forget about it 3303 * in the protocol layers. 3304 * 3305 * Now it will return ENETDOWN, if device have just gone down, 3306 * but then it will block. 3307 */ 3308 3309 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3310 3311 /* 3312 * An error occurred so return it. Because skb_recv_datagram() 3313 * handles the blocking we don't see and worry about blocking 3314 * retries. 3315 */ 3316 3317 if (skb == NULL) 3318 goto out; 3319 3320 if (pkt_sk(sk)->pressure) 3321 packet_rcv_has_room(pkt_sk(sk), NULL); 3322 3323 if (pkt_sk(sk)->has_vnet_hdr) { 3324 err = packet_rcv_vnet(msg, skb, &len); 3325 if (err) 3326 goto out_free; 3327 vnet_hdr_len = sizeof(struct virtio_net_hdr); 3328 } 3329 3330 /* You lose any data beyond the buffer you gave. If it worries 3331 * a user program they can ask the device for its MTU 3332 * anyway. 3333 */ 3334 copied = skb->len; 3335 if (copied > len) { 3336 copied = len; 3337 msg->msg_flags |= MSG_TRUNC; 3338 } 3339 3340 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3341 if (err) 3342 goto out_free; 3343 3344 if (sock->type != SOCK_PACKET) { 3345 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3346 3347 /* Original length was stored in sockaddr_ll fields */ 3348 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3349 sll->sll_family = AF_PACKET; 3350 sll->sll_protocol = skb->protocol; 3351 } 3352 3353 sock_recv_ts_and_drops(msg, sk, skb); 3354 3355 if (msg->msg_name) { 3356 /* If the address length field is there to be filled 3357 * in, we fill it in now. 3358 */ 3359 if (sock->type == SOCK_PACKET) { 3360 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3361 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3362 } else { 3363 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3364 3365 msg->msg_namelen = sll->sll_halen + 3366 offsetof(struct sockaddr_ll, sll_addr); 3367 } 3368 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 3369 msg->msg_namelen); 3370 } 3371 3372 if (pkt_sk(sk)->auxdata) { 3373 struct tpacket_auxdata aux; 3374 3375 aux.tp_status = TP_STATUS_USER; 3376 if (skb->ip_summed == CHECKSUM_PARTIAL) 3377 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3378 else if (skb->pkt_type != PACKET_OUTGOING && 3379 (skb->ip_summed == CHECKSUM_COMPLETE || 3380 skb_csum_unnecessary(skb))) 3381 aux.tp_status |= TP_STATUS_CSUM_VALID; 3382 3383 aux.tp_len = origlen; 3384 aux.tp_snaplen = skb->len; 3385 aux.tp_mac = 0; 3386 aux.tp_net = skb_network_offset(skb); 3387 if (skb_vlan_tag_present(skb)) { 3388 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3389 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3390 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3391 } else { 3392 aux.tp_vlan_tci = 0; 3393 aux.tp_vlan_tpid = 0; 3394 } 3395 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3396 } 3397 3398 /* 3399 * Free or return the buffer as appropriate. Again this 3400 * hides all the races and re-entrancy issues from us. 3401 */ 3402 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3403 3404 out_free: 3405 skb_free_datagram(sk, skb); 3406 out: 3407 return err; 3408 } 3409 3410 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3411 int *uaddr_len, int peer) 3412 { 3413 struct net_device *dev; 3414 struct sock *sk = sock->sk; 3415 3416 if (peer) 3417 return -EOPNOTSUPP; 3418 3419 uaddr->sa_family = AF_PACKET; 3420 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3421 rcu_read_lock(); 3422 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3423 if (dev) 3424 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3425 rcu_read_unlock(); 3426 *uaddr_len = sizeof(*uaddr); 3427 3428 return 0; 3429 } 3430 3431 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3432 int *uaddr_len, int peer) 3433 { 3434 struct net_device *dev; 3435 struct sock *sk = sock->sk; 3436 struct packet_sock *po = pkt_sk(sk); 3437 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3438 3439 if (peer) 3440 return -EOPNOTSUPP; 3441 3442 sll->sll_family = AF_PACKET; 3443 sll->sll_ifindex = po->ifindex; 3444 sll->sll_protocol = po->num; 3445 sll->sll_pkttype = 0; 3446 rcu_read_lock(); 3447 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3448 if (dev) { 3449 sll->sll_hatype = dev->type; 3450 sll->sll_halen = dev->addr_len; 3451 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3452 } else { 3453 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3454 sll->sll_halen = 0; 3455 } 3456 rcu_read_unlock(); 3457 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3458 3459 return 0; 3460 } 3461 3462 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3463 int what) 3464 { 3465 switch (i->type) { 3466 case PACKET_MR_MULTICAST: 3467 if (i->alen != dev->addr_len) 3468 return -EINVAL; 3469 if (what > 0) 3470 return dev_mc_add(dev, i->addr); 3471 else 3472 return dev_mc_del(dev, i->addr); 3473 break; 3474 case PACKET_MR_PROMISC: 3475 return dev_set_promiscuity(dev, what); 3476 case PACKET_MR_ALLMULTI: 3477 return dev_set_allmulti(dev, what); 3478 case PACKET_MR_UNICAST: 3479 if (i->alen != dev->addr_len) 3480 return -EINVAL; 3481 if (what > 0) 3482 return dev_uc_add(dev, i->addr); 3483 else 3484 return dev_uc_del(dev, i->addr); 3485 break; 3486 default: 3487 break; 3488 } 3489 return 0; 3490 } 3491 3492 static void packet_dev_mclist_delete(struct net_device *dev, 3493 struct packet_mclist **mlp) 3494 { 3495 struct packet_mclist *ml; 3496 3497 while ((ml = *mlp) != NULL) { 3498 if (ml->ifindex == dev->ifindex) { 3499 packet_dev_mc(dev, ml, -1); 3500 *mlp = ml->next; 3501 kfree(ml); 3502 } else 3503 mlp = &ml->next; 3504 } 3505 } 3506 3507 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3508 { 3509 struct packet_sock *po = pkt_sk(sk); 3510 struct packet_mclist *ml, *i; 3511 struct net_device *dev; 3512 int err; 3513 3514 rtnl_lock(); 3515 3516 err = -ENODEV; 3517 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3518 if (!dev) 3519 goto done; 3520 3521 err = -EINVAL; 3522 if (mreq->mr_alen > dev->addr_len) 3523 goto done; 3524 3525 err = -ENOBUFS; 3526 i = kmalloc(sizeof(*i), GFP_KERNEL); 3527 if (i == NULL) 3528 goto done; 3529 3530 err = 0; 3531 for (ml = po->mclist; ml; ml = ml->next) { 3532 if (ml->ifindex == mreq->mr_ifindex && 3533 ml->type == mreq->mr_type && 3534 ml->alen == mreq->mr_alen && 3535 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3536 ml->count++; 3537 /* Free the new element ... */ 3538 kfree(i); 3539 goto done; 3540 } 3541 } 3542 3543 i->type = mreq->mr_type; 3544 i->ifindex = mreq->mr_ifindex; 3545 i->alen = mreq->mr_alen; 3546 memcpy(i->addr, mreq->mr_address, i->alen); 3547 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3548 i->count = 1; 3549 i->next = po->mclist; 3550 po->mclist = i; 3551 err = packet_dev_mc(dev, i, 1); 3552 if (err) { 3553 po->mclist = i->next; 3554 kfree(i); 3555 } 3556 3557 done: 3558 rtnl_unlock(); 3559 return err; 3560 } 3561 3562 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3563 { 3564 struct packet_mclist *ml, **mlp; 3565 3566 rtnl_lock(); 3567 3568 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3569 if (ml->ifindex == mreq->mr_ifindex && 3570 ml->type == mreq->mr_type && 3571 ml->alen == mreq->mr_alen && 3572 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3573 if (--ml->count == 0) { 3574 struct net_device *dev; 3575 *mlp = ml->next; 3576 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3577 if (dev) 3578 packet_dev_mc(dev, ml, -1); 3579 kfree(ml); 3580 } 3581 break; 3582 } 3583 } 3584 rtnl_unlock(); 3585 return 0; 3586 } 3587 3588 static void packet_flush_mclist(struct sock *sk) 3589 { 3590 struct packet_sock *po = pkt_sk(sk); 3591 struct packet_mclist *ml; 3592 3593 if (!po->mclist) 3594 return; 3595 3596 rtnl_lock(); 3597 while ((ml = po->mclist) != NULL) { 3598 struct net_device *dev; 3599 3600 po->mclist = ml->next; 3601 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3602 if (dev != NULL) 3603 packet_dev_mc(dev, ml, -1); 3604 kfree(ml); 3605 } 3606 rtnl_unlock(); 3607 } 3608 3609 static int 3610 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3611 { 3612 struct sock *sk = sock->sk; 3613 struct packet_sock *po = pkt_sk(sk); 3614 int ret; 3615 3616 if (level != SOL_PACKET) 3617 return -ENOPROTOOPT; 3618 3619 switch (optname) { 3620 case PACKET_ADD_MEMBERSHIP: 3621 case PACKET_DROP_MEMBERSHIP: 3622 { 3623 struct packet_mreq_max mreq; 3624 int len = optlen; 3625 memset(&mreq, 0, sizeof(mreq)); 3626 if (len < sizeof(struct packet_mreq)) 3627 return -EINVAL; 3628 if (len > sizeof(mreq)) 3629 len = sizeof(mreq); 3630 if (copy_from_user(&mreq, optval, len)) 3631 return -EFAULT; 3632 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3633 return -EINVAL; 3634 if (optname == PACKET_ADD_MEMBERSHIP) 3635 ret = packet_mc_add(sk, &mreq); 3636 else 3637 ret = packet_mc_drop(sk, &mreq); 3638 return ret; 3639 } 3640 3641 case PACKET_RX_RING: 3642 case PACKET_TX_RING: 3643 { 3644 union tpacket_req_u req_u; 3645 int len; 3646 3647 switch (po->tp_version) { 3648 case TPACKET_V1: 3649 case TPACKET_V2: 3650 len = sizeof(req_u.req); 3651 break; 3652 case TPACKET_V3: 3653 default: 3654 len = sizeof(req_u.req3); 3655 break; 3656 } 3657 if (optlen < len) 3658 return -EINVAL; 3659 if (copy_from_user(&req_u.req, optval, len)) 3660 return -EFAULT; 3661 return packet_set_ring(sk, &req_u, 0, 3662 optname == PACKET_TX_RING); 3663 } 3664 case PACKET_COPY_THRESH: 3665 { 3666 int val; 3667 3668 if (optlen != sizeof(val)) 3669 return -EINVAL; 3670 if (copy_from_user(&val, optval, sizeof(val))) 3671 return -EFAULT; 3672 3673 pkt_sk(sk)->copy_thresh = val; 3674 return 0; 3675 } 3676 case PACKET_VERSION: 3677 { 3678 int val; 3679 3680 if (optlen != sizeof(val)) 3681 return -EINVAL; 3682 if (copy_from_user(&val, optval, sizeof(val))) 3683 return -EFAULT; 3684 switch (val) { 3685 case TPACKET_V1: 3686 case TPACKET_V2: 3687 case TPACKET_V3: 3688 break; 3689 default: 3690 return -EINVAL; 3691 } 3692 lock_sock(sk); 3693 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3694 ret = -EBUSY; 3695 } else { 3696 po->tp_version = val; 3697 ret = 0; 3698 } 3699 release_sock(sk); 3700 return ret; 3701 } 3702 case PACKET_RESERVE: 3703 { 3704 unsigned int val; 3705 3706 if (optlen != sizeof(val)) 3707 return -EINVAL; 3708 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3709 return -EBUSY; 3710 if (copy_from_user(&val, optval, sizeof(val))) 3711 return -EFAULT; 3712 if (val > INT_MAX) 3713 return -EINVAL; 3714 po->tp_reserve = val; 3715 return 0; 3716 } 3717 case PACKET_LOSS: 3718 { 3719 unsigned int val; 3720 3721 if (optlen != sizeof(val)) 3722 return -EINVAL; 3723 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3724 return -EBUSY; 3725 if (copy_from_user(&val, optval, sizeof(val))) 3726 return -EFAULT; 3727 po->tp_loss = !!val; 3728 return 0; 3729 } 3730 case PACKET_AUXDATA: 3731 { 3732 int val; 3733 3734 if (optlen < sizeof(val)) 3735 return -EINVAL; 3736 if (copy_from_user(&val, optval, sizeof(val))) 3737 return -EFAULT; 3738 3739 po->auxdata = !!val; 3740 return 0; 3741 } 3742 case PACKET_ORIGDEV: 3743 { 3744 int val; 3745 3746 if (optlen < sizeof(val)) 3747 return -EINVAL; 3748 if (copy_from_user(&val, optval, sizeof(val))) 3749 return -EFAULT; 3750 3751 po->origdev = !!val; 3752 return 0; 3753 } 3754 case PACKET_VNET_HDR: 3755 { 3756 int val; 3757 3758 if (sock->type != SOCK_RAW) 3759 return -EINVAL; 3760 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3761 return -EBUSY; 3762 if (optlen < sizeof(val)) 3763 return -EINVAL; 3764 if (copy_from_user(&val, optval, sizeof(val))) 3765 return -EFAULT; 3766 3767 po->has_vnet_hdr = !!val; 3768 return 0; 3769 } 3770 case PACKET_TIMESTAMP: 3771 { 3772 int val; 3773 3774 if (optlen != sizeof(val)) 3775 return -EINVAL; 3776 if (copy_from_user(&val, optval, sizeof(val))) 3777 return -EFAULT; 3778 3779 po->tp_tstamp = val; 3780 return 0; 3781 } 3782 case PACKET_FANOUT: 3783 { 3784 int val; 3785 3786 if (optlen != sizeof(val)) 3787 return -EINVAL; 3788 if (copy_from_user(&val, optval, sizeof(val))) 3789 return -EFAULT; 3790 3791 return fanout_add(sk, val & 0xffff, val >> 16); 3792 } 3793 case PACKET_FANOUT_DATA: 3794 { 3795 if (!po->fanout) 3796 return -EINVAL; 3797 3798 return fanout_set_data(po, optval, optlen); 3799 } 3800 case PACKET_TX_HAS_OFF: 3801 { 3802 unsigned int val; 3803 3804 if (optlen != sizeof(val)) 3805 return -EINVAL; 3806 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3807 return -EBUSY; 3808 if (copy_from_user(&val, optval, sizeof(val))) 3809 return -EFAULT; 3810 po->tp_tx_has_off = !!val; 3811 return 0; 3812 } 3813 case PACKET_QDISC_BYPASS: 3814 { 3815 int val; 3816 3817 if (optlen != sizeof(val)) 3818 return -EINVAL; 3819 if (copy_from_user(&val, optval, sizeof(val))) 3820 return -EFAULT; 3821 3822 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3823 return 0; 3824 } 3825 default: 3826 return -ENOPROTOOPT; 3827 } 3828 } 3829 3830 static int packet_getsockopt(struct socket *sock, int level, int optname, 3831 char __user *optval, int __user *optlen) 3832 { 3833 int len; 3834 int val, lv = sizeof(val); 3835 struct sock *sk = sock->sk; 3836 struct packet_sock *po = pkt_sk(sk); 3837 void *data = &val; 3838 union tpacket_stats_u st; 3839 struct tpacket_rollover_stats rstats; 3840 3841 if (level != SOL_PACKET) 3842 return -ENOPROTOOPT; 3843 3844 if (get_user(len, optlen)) 3845 return -EFAULT; 3846 3847 if (len < 0) 3848 return -EINVAL; 3849 3850 switch (optname) { 3851 case PACKET_STATISTICS: 3852 spin_lock_bh(&sk->sk_receive_queue.lock); 3853 memcpy(&st, &po->stats, sizeof(st)); 3854 memset(&po->stats, 0, sizeof(po->stats)); 3855 spin_unlock_bh(&sk->sk_receive_queue.lock); 3856 3857 if (po->tp_version == TPACKET_V3) { 3858 lv = sizeof(struct tpacket_stats_v3); 3859 st.stats3.tp_packets += st.stats3.tp_drops; 3860 data = &st.stats3; 3861 } else { 3862 lv = sizeof(struct tpacket_stats); 3863 st.stats1.tp_packets += st.stats1.tp_drops; 3864 data = &st.stats1; 3865 } 3866 3867 break; 3868 case PACKET_AUXDATA: 3869 val = po->auxdata; 3870 break; 3871 case PACKET_ORIGDEV: 3872 val = po->origdev; 3873 break; 3874 case PACKET_VNET_HDR: 3875 val = po->has_vnet_hdr; 3876 break; 3877 case PACKET_VERSION: 3878 val = po->tp_version; 3879 break; 3880 case PACKET_HDRLEN: 3881 if (len > sizeof(int)) 3882 len = sizeof(int); 3883 if (len < sizeof(int)) 3884 return -EINVAL; 3885 if (copy_from_user(&val, optval, len)) 3886 return -EFAULT; 3887 switch (val) { 3888 case TPACKET_V1: 3889 val = sizeof(struct tpacket_hdr); 3890 break; 3891 case TPACKET_V2: 3892 val = sizeof(struct tpacket2_hdr); 3893 break; 3894 case TPACKET_V3: 3895 val = sizeof(struct tpacket3_hdr); 3896 break; 3897 default: 3898 return -EINVAL; 3899 } 3900 break; 3901 case PACKET_RESERVE: 3902 val = po->tp_reserve; 3903 break; 3904 case PACKET_LOSS: 3905 val = po->tp_loss; 3906 break; 3907 case PACKET_TIMESTAMP: 3908 val = po->tp_tstamp; 3909 break; 3910 case PACKET_FANOUT: 3911 val = (po->fanout ? 3912 ((u32)po->fanout->id | 3913 ((u32)po->fanout->type << 16) | 3914 ((u32)po->fanout->flags << 24)) : 3915 0); 3916 break; 3917 case PACKET_ROLLOVER_STATS: 3918 if (!po->rollover) 3919 return -EINVAL; 3920 rstats.tp_all = atomic_long_read(&po->rollover->num); 3921 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 3922 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 3923 data = &rstats; 3924 lv = sizeof(rstats); 3925 break; 3926 case PACKET_TX_HAS_OFF: 3927 val = po->tp_tx_has_off; 3928 break; 3929 case PACKET_QDISC_BYPASS: 3930 val = packet_use_direct_xmit(po); 3931 break; 3932 default: 3933 return -ENOPROTOOPT; 3934 } 3935 3936 if (len > lv) 3937 len = lv; 3938 if (put_user(len, optlen)) 3939 return -EFAULT; 3940 if (copy_to_user(optval, data, len)) 3941 return -EFAULT; 3942 return 0; 3943 } 3944 3945 3946 #ifdef CONFIG_COMPAT 3947 static int compat_packet_setsockopt(struct socket *sock, int level, int optname, 3948 char __user *optval, unsigned int optlen) 3949 { 3950 struct packet_sock *po = pkt_sk(sock->sk); 3951 3952 if (level != SOL_PACKET) 3953 return -ENOPROTOOPT; 3954 3955 if (optname == PACKET_FANOUT_DATA && 3956 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) { 3957 optval = (char __user *)get_compat_bpf_fprog(optval); 3958 if (!optval) 3959 return -EFAULT; 3960 optlen = sizeof(struct sock_fprog); 3961 } 3962 3963 return packet_setsockopt(sock, level, optname, optval, optlen); 3964 } 3965 #endif 3966 3967 static int packet_notifier(struct notifier_block *this, 3968 unsigned long msg, void *ptr) 3969 { 3970 struct sock *sk; 3971 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3972 struct net *net = dev_net(dev); 3973 3974 rcu_read_lock(); 3975 sk_for_each_rcu(sk, &net->packet.sklist) { 3976 struct packet_sock *po = pkt_sk(sk); 3977 3978 switch (msg) { 3979 case NETDEV_UNREGISTER: 3980 if (po->mclist) 3981 packet_dev_mclist_delete(dev, &po->mclist); 3982 /* fallthrough */ 3983 3984 case NETDEV_DOWN: 3985 if (dev->ifindex == po->ifindex) { 3986 spin_lock(&po->bind_lock); 3987 if (po->running) { 3988 __unregister_prot_hook(sk, false); 3989 sk->sk_err = ENETDOWN; 3990 if (!sock_flag(sk, SOCK_DEAD)) 3991 sk->sk_error_report(sk); 3992 } 3993 if (msg == NETDEV_UNREGISTER) { 3994 packet_cached_dev_reset(po); 3995 po->ifindex = -1; 3996 if (po->prot_hook.dev) 3997 dev_put(po->prot_hook.dev); 3998 po->prot_hook.dev = NULL; 3999 } 4000 spin_unlock(&po->bind_lock); 4001 } 4002 break; 4003 case NETDEV_UP: 4004 if (dev->ifindex == po->ifindex) { 4005 spin_lock(&po->bind_lock); 4006 if (po->num) 4007 register_prot_hook(sk); 4008 spin_unlock(&po->bind_lock); 4009 } 4010 break; 4011 } 4012 } 4013 rcu_read_unlock(); 4014 return NOTIFY_DONE; 4015 } 4016 4017 4018 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4019 unsigned long arg) 4020 { 4021 struct sock *sk = sock->sk; 4022 4023 switch (cmd) { 4024 case SIOCOUTQ: 4025 { 4026 int amount = sk_wmem_alloc_get(sk); 4027 4028 return put_user(amount, (int __user *)arg); 4029 } 4030 case SIOCINQ: 4031 { 4032 struct sk_buff *skb; 4033 int amount = 0; 4034 4035 spin_lock_bh(&sk->sk_receive_queue.lock); 4036 skb = skb_peek(&sk->sk_receive_queue); 4037 if (skb) 4038 amount = skb->len; 4039 spin_unlock_bh(&sk->sk_receive_queue.lock); 4040 return put_user(amount, (int __user *)arg); 4041 } 4042 case SIOCGSTAMP: 4043 return sock_get_timestamp(sk, (struct timeval __user *)arg); 4044 case SIOCGSTAMPNS: 4045 return sock_get_timestampns(sk, (struct timespec __user *)arg); 4046 4047 #ifdef CONFIG_INET 4048 case SIOCADDRT: 4049 case SIOCDELRT: 4050 case SIOCDARP: 4051 case SIOCGARP: 4052 case SIOCSARP: 4053 case SIOCGIFADDR: 4054 case SIOCSIFADDR: 4055 case SIOCGIFBRDADDR: 4056 case SIOCSIFBRDADDR: 4057 case SIOCGIFNETMASK: 4058 case SIOCSIFNETMASK: 4059 case SIOCGIFDSTADDR: 4060 case SIOCSIFDSTADDR: 4061 case SIOCSIFFLAGS: 4062 return inet_dgram_ops.ioctl(sock, cmd, arg); 4063 #endif 4064 4065 default: 4066 return -ENOIOCTLCMD; 4067 } 4068 return 0; 4069 } 4070 4071 static unsigned int packet_poll(struct file *file, struct socket *sock, 4072 poll_table *wait) 4073 { 4074 struct sock *sk = sock->sk; 4075 struct packet_sock *po = pkt_sk(sk); 4076 unsigned int mask = datagram_poll(file, sock, wait); 4077 4078 spin_lock_bh(&sk->sk_receive_queue.lock); 4079 if (po->rx_ring.pg_vec) { 4080 if (!packet_previous_rx_frame(po, &po->rx_ring, 4081 TP_STATUS_KERNEL)) 4082 mask |= POLLIN | POLLRDNORM; 4083 } 4084 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 4085 po->pressure = 0; 4086 spin_unlock_bh(&sk->sk_receive_queue.lock); 4087 spin_lock_bh(&sk->sk_write_queue.lock); 4088 if (po->tx_ring.pg_vec) { 4089 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4090 mask |= POLLOUT | POLLWRNORM; 4091 } 4092 spin_unlock_bh(&sk->sk_write_queue.lock); 4093 return mask; 4094 } 4095 4096 4097 /* Dirty? Well, I still did not learn better way to account 4098 * for user mmaps. 4099 */ 4100 4101 static void packet_mm_open(struct vm_area_struct *vma) 4102 { 4103 struct file *file = vma->vm_file; 4104 struct socket *sock = file->private_data; 4105 struct sock *sk = sock->sk; 4106 4107 if (sk) 4108 atomic_inc(&pkt_sk(sk)->mapped); 4109 } 4110 4111 static void packet_mm_close(struct vm_area_struct *vma) 4112 { 4113 struct file *file = vma->vm_file; 4114 struct socket *sock = file->private_data; 4115 struct sock *sk = sock->sk; 4116 4117 if (sk) 4118 atomic_dec(&pkt_sk(sk)->mapped); 4119 } 4120 4121 static const struct vm_operations_struct packet_mmap_ops = { 4122 .open = packet_mm_open, 4123 .close = packet_mm_close, 4124 }; 4125 4126 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4127 unsigned int len) 4128 { 4129 int i; 4130 4131 for (i = 0; i < len; i++) { 4132 if (likely(pg_vec[i].buffer)) { 4133 if (is_vmalloc_addr(pg_vec[i].buffer)) 4134 vfree(pg_vec[i].buffer); 4135 else 4136 free_pages((unsigned long)pg_vec[i].buffer, 4137 order); 4138 pg_vec[i].buffer = NULL; 4139 } 4140 } 4141 kfree(pg_vec); 4142 } 4143 4144 static char *alloc_one_pg_vec_page(unsigned long order) 4145 { 4146 char *buffer; 4147 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4148 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4149 4150 buffer = (char *) __get_free_pages(gfp_flags, order); 4151 if (buffer) 4152 return buffer; 4153 4154 /* __get_free_pages failed, fall back to vmalloc */ 4155 buffer = vzalloc((1 << order) * PAGE_SIZE); 4156 if (buffer) 4157 return buffer; 4158 4159 /* vmalloc failed, lets dig into swap here */ 4160 gfp_flags &= ~__GFP_NORETRY; 4161 buffer = (char *) __get_free_pages(gfp_flags, order); 4162 if (buffer) 4163 return buffer; 4164 4165 /* complete and utter failure */ 4166 return NULL; 4167 } 4168 4169 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4170 { 4171 unsigned int block_nr = req->tp_block_nr; 4172 struct pgv *pg_vec; 4173 int i; 4174 4175 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 4176 if (unlikely(!pg_vec)) 4177 goto out; 4178 4179 for (i = 0; i < block_nr; i++) { 4180 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4181 if (unlikely(!pg_vec[i].buffer)) 4182 goto out_free_pgvec; 4183 } 4184 4185 out: 4186 return pg_vec; 4187 4188 out_free_pgvec: 4189 free_pg_vec(pg_vec, order, block_nr); 4190 pg_vec = NULL; 4191 goto out; 4192 } 4193 4194 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4195 int closing, int tx_ring) 4196 { 4197 struct pgv *pg_vec = NULL; 4198 struct packet_sock *po = pkt_sk(sk); 4199 int was_running, order = 0; 4200 struct packet_ring_buffer *rb; 4201 struct sk_buff_head *rb_queue; 4202 __be16 num; 4203 int err = -EINVAL; 4204 /* Added to avoid minimal code churn */ 4205 struct tpacket_req *req = &req_u->req; 4206 4207 lock_sock(sk); 4208 4209 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4210 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4211 4212 err = -EBUSY; 4213 if (!closing) { 4214 if (atomic_read(&po->mapped)) 4215 goto out; 4216 if (packet_read_pending(rb)) 4217 goto out; 4218 } 4219 4220 if (req->tp_block_nr) { 4221 /* Sanity tests and some calculations */ 4222 err = -EBUSY; 4223 if (unlikely(rb->pg_vec)) 4224 goto out; 4225 4226 switch (po->tp_version) { 4227 case TPACKET_V1: 4228 po->tp_hdrlen = TPACKET_HDRLEN; 4229 break; 4230 case TPACKET_V2: 4231 po->tp_hdrlen = TPACKET2_HDRLEN; 4232 break; 4233 case TPACKET_V3: 4234 po->tp_hdrlen = TPACKET3_HDRLEN; 4235 break; 4236 } 4237 4238 err = -EINVAL; 4239 if (unlikely((int)req->tp_block_size <= 0)) 4240 goto out; 4241 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4242 goto out; 4243 if (po->tp_version >= TPACKET_V3 && 4244 req->tp_block_size <= 4245 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv)) 4246 goto out; 4247 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 4248 po->tp_reserve)) 4249 goto out; 4250 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4251 goto out; 4252 4253 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4254 if (unlikely(rb->frames_per_block == 0)) 4255 goto out; 4256 if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr)) 4257 goto out; 4258 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4259 req->tp_frame_nr)) 4260 goto out; 4261 4262 err = -ENOMEM; 4263 order = get_order(req->tp_block_size); 4264 pg_vec = alloc_pg_vec(req, order); 4265 if (unlikely(!pg_vec)) 4266 goto out; 4267 switch (po->tp_version) { 4268 case TPACKET_V3: 4269 /* Block transmit is not supported yet */ 4270 if (!tx_ring) { 4271 init_prb_bdqc(po, rb, pg_vec, req_u); 4272 } else { 4273 struct tpacket_req3 *req3 = &req_u->req3; 4274 4275 if (req3->tp_retire_blk_tov || 4276 req3->tp_sizeof_priv || 4277 req3->tp_feature_req_word) { 4278 err = -EINVAL; 4279 goto out; 4280 } 4281 } 4282 break; 4283 default: 4284 break; 4285 } 4286 } 4287 /* Done */ 4288 else { 4289 err = -EINVAL; 4290 if (unlikely(req->tp_frame_nr)) 4291 goto out; 4292 } 4293 4294 4295 /* Detach socket from network */ 4296 spin_lock(&po->bind_lock); 4297 was_running = po->running; 4298 num = po->num; 4299 if (was_running) { 4300 po->num = 0; 4301 __unregister_prot_hook(sk, false); 4302 } 4303 spin_unlock(&po->bind_lock); 4304 4305 synchronize_net(); 4306 4307 err = -EBUSY; 4308 mutex_lock(&po->pg_vec_lock); 4309 if (closing || atomic_read(&po->mapped) == 0) { 4310 err = 0; 4311 spin_lock_bh(&rb_queue->lock); 4312 swap(rb->pg_vec, pg_vec); 4313 rb->frame_max = (req->tp_frame_nr - 1); 4314 rb->head = 0; 4315 rb->frame_size = req->tp_frame_size; 4316 spin_unlock_bh(&rb_queue->lock); 4317 4318 swap(rb->pg_vec_order, order); 4319 swap(rb->pg_vec_len, req->tp_block_nr); 4320 4321 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4322 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4323 tpacket_rcv : packet_rcv; 4324 skb_queue_purge(rb_queue); 4325 if (atomic_read(&po->mapped)) 4326 pr_err("packet_mmap: vma is busy: %d\n", 4327 atomic_read(&po->mapped)); 4328 } 4329 mutex_unlock(&po->pg_vec_lock); 4330 4331 spin_lock(&po->bind_lock); 4332 if (was_running) { 4333 po->num = num; 4334 register_prot_hook(sk); 4335 } 4336 spin_unlock(&po->bind_lock); 4337 if (closing && (po->tp_version > TPACKET_V2)) { 4338 /* Because we don't support block-based V3 on tx-ring */ 4339 if (!tx_ring) 4340 prb_shutdown_retire_blk_timer(po, rb_queue); 4341 } 4342 4343 if (pg_vec) 4344 free_pg_vec(pg_vec, order, req->tp_block_nr); 4345 out: 4346 release_sock(sk); 4347 return err; 4348 } 4349 4350 static int packet_mmap(struct file *file, struct socket *sock, 4351 struct vm_area_struct *vma) 4352 { 4353 struct sock *sk = sock->sk; 4354 struct packet_sock *po = pkt_sk(sk); 4355 unsigned long size, expected_size; 4356 struct packet_ring_buffer *rb; 4357 unsigned long start; 4358 int err = -EINVAL; 4359 int i; 4360 4361 if (vma->vm_pgoff) 4362 return -EINVAL; 4363 4364 mutex_lock(&po->pg_vec_lock); 4365 4366 expected_size = 0; 4367 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4368 if (rb->pg_vec) { 4369 expected_size += rb->pg_vec_len 4370 * rb->pg_vec_pages 4371 * PAGE_SIZE; 4372 } 4373 } 4374 4375 if (expected_size == 0) 4376 goto out; 4377 4378 size = vma->vm_end - vma->vm_start; 4379 if (size != expected_size) 4380 goto out; 4381 4382 start = vma->vm_start; 4383 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4384 if (rb->pg_vec == NULL) 4385 continue; 4386 4387 for (i = 0; i < rb->pg_vec_len; i++) { 4388 struct page *page; 4389 void *kaddr = rb->pg_vec[i].buffer; 4390 int pg_num; 4391 4392 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4393 page = pgv_to_page(kaddr); 4394 err = vm_insert_page(vma, start, page); 4395 if (unlikely(err)) 4396 goto out; 4397 start += PAGE_SIZE; 4398 kaddr += PAGE_SIZE; 4399 } 4400 } 4401 } 4402 4403 atomic_inc(&po->mapped); 4404 vma->vm_ops = &packet_mmap_ops; 4405 err = 0; 4406 4407 out: 4408 mutex_unlock(&po->pg_vec_lock); 4409 return err; 4410 } 4411 4412 static const struct proto_ops packet_ops_spkt = { 4413 .family = PF_PACKET, 4414 .owner = THIS_MODULE, 4415 .release = packet_release, 4416 .bind = packet_bind_spkt, 4417 .connect = sock_no_connect, 4418 .socketpair = sock_no_socketpair, 4419 .accept = sock_no_accept, 4420 .getname = packet_getname_spkt, 4421 .poll = datagram_poll, 4422 .ioctl = packet_ioctl, 4423 .listen = sock_no_listen, 4424 .shutdown = sock_no_shutdown, 4425 .setsockopt = sock_no_setsockopt, 4426 .getsockopt = sock_no_getsockopt, 4427 .sendmsg = packet_sendmsg_spkt, 4428 .recvmsg = packet_recvmsg, 4429 .mmap = sock_no_mmap, 4430 .sendpage = sock_no_sendpage, 4431 }; 4432 4433 static const struct proto_ops packet_ops = { 4434 .family = PF_PACKET, 4435 .owner = THIS_MODULE, 4436 .release = packet_release, 4437 .bind = packet_bind, 4438 .connect = sock_no_connect, 4439 .socketpair = sock_no_socketpair, 4440 .accept = sock_no_accept, 4441 .getname = packet_getname, 4442 .poll = packet_poll, 4443 .ioctl = packet_ioctl, 4444 .listen = sock_no_listen, 4445 .shutdown = sock_no_shutdown, 4446 .setsockopt = packet_setsockopt, 4447 .getsockopt = packet_getsockopt, 4448 #ifdef CONFIG_COMPAT 4449 .compat_setsockopt = compat_packet_setsockopt, 4450 #endif 4451 .sendmsg = packet_sendmsg, 4452 .recvmsg = packet_recvmsg, 4453 .mmap = packet_mmap, 4454 .sendpage = sock_no_sendpage, 4455 }; 4456 4457 static const struct net_proto_family packet_family_ops = { 4458 .family = PF_PACKET, 4459 .create = packet_create, 4460 .owner = THIS_MODULE, 4461 }; 4462 4463 static struct notifier_block packet_netdev_notifier = { 4464 .notifier_call = packet_notifier, 4465 }; 4466 4467 #ifdef CONFIG_PROC_FS 4468 4469 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4470 __acquires(RCU) 4471 { 4472 struct net *net = seq_file_net(seq); 4473 4474 rcu_read_lock(); 4475 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4476 } 4477 4478 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4479 { 4480 struct net *net = seq_file_net(seq); 4481 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4482 } 4483 4484 static void packet_seq_stop(struct seq_file *seq, void *v) 4485 __releases(RCU) 4486 { 4487 rcu_read_unlock(); 4488 } 4489 4490 static int packet_seq_show(struct seq_file *seq, void *v) 4491 { 4492 if (v == SEQ_START_TOKEN) 4493 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4494 else { 4495 struct sock *s = sk_entry(v); 4496 const struct packet_sock *po = pkt_sk(s); 4497 4498 seq_printf(seq, 4499 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4500 s, 4501 atomic_read(&s->sk_refcnt), 4502 s->sk_type, 4503 ntohs(po->num), 4504 po->ifindex, 4505 po->running, 4506 atomic_read(&s->sk_rmem_alloc), 4507 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4508 sock_i_ino(s)); 4509 } 4510 4511 return 0; 4512 } 4513 4514 static const struct seq_operations packet_seq_ops = { 4515 .start = packet_seq_start, 4516 .next = packet_seq_next, 4517 .stop = packet_seq_stop, 4518 .show = packet_seq_show, 4519 }; 4520 4521 static int packet_seq_open(struct inode *inode, struct file *file) 4522 { 4523 return seq_open_net(inode, file, &packet_seq_ops, 4524 sizeof(struct seq_net_private)); 4525 } 4526 4527 static const struct file_operations packet_seq_fops = { 4528 .owner = THIS_MODULE, 4529 .open = packet_seq_open, 4530 .read = seq_read, 4531 .llseek = seq_lseek, 4532 .release = seq_release_net, 4533 }; 4534 4535 #endif 4536 4537 static int __net_init packet_net_init(struct net *net) 4538 { 4539 mutex_init(&net->packet.sklist_lock); 4540 INIT_HLIST_HEAD(&net->packet.sklist); 4541 4542 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4543 return -ENOMEM; 4544 4545 return 0; 4546 } 4547 4548 static void __net_exit packet_net_exit(struct net *net) 4549 { 4550 remove_proc_entry("packet", net->proc_net); 4551 } 4552 4553 static struct pernet_operations packet_net_ops = { 4554 .init = packet_net_init, 4555 .exit = packet_net_exit, 4556 }; 4557 4558 4559 static void __exit packet_exit(void) 4560 { 4561 unregister_netdevice_notifier(&packet_netdev_notifier); 4562 unregister_pernet_subsys(&packet_net_ops); 4563 sock_unregister(PF_PACKET); 4564 proto_unregister(&packet_proto); 4565 } 4566 4567 static int __init packet_init(void) 4568 { 4569 int rc = proto_register(&packet_proto, 0); 4570 4571 if (rc != 0) 4572 goto out; 4573 4574 sock_register(&packet_family_ops); 4575 register_pernet_subsys(&packet_net_ops); 4576 register_netdevice_notifier(&packet_netdev_notifier); 4577 out: 4578 return rc; 4579 } 4580 4581 module_init(packet_init); 4582 module_exit(packet_exit); 4583 MODULE_LICENSE("GPL"); 4584 MODULE_ALIAS_NETPROTO(PF_PACKET); 4585