1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <asm/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/percpu.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 #include <linux/bpf.h> 96 97 #include "internal.h" 98 99 /* 100 Assumptions: 101 - if device has no dev->hard_header routine, it adds and removes ll header 102 inside itself. In this case ll header is invisible outside of device, 103 but higher levels still should reserve dev->hard_header_len. 104 Some devices are enough clever to reallocate skb, when header 105 will not fit to reserved space (tunnel), another ones are silly 106 (PPP). 107 - packet socket receives packets with pulled ll header, 108 so that SOCK_RAW should push it back. 109 110 On receive: 111 ----------- 112 113 Incoming, dev->hard_header!=NULL 114 mac_header -> ll header 115 data -> data 116 117 Outgoing, dev->hard_header!=NULL 118 mac_header -> ll header 119 data -> ll header 120 121 Incoming, dev->hard_header==NULL 122 mac_header -> UNKNOWN position. It is very likely, that it points to ll 123 header. PPP makes it, that is wrong, because introduce 124 assymetry between rx and tx paths. 125 data -> data 126 127 Outgoing, dev->hard_header==NULL 128 mac_header -> data. ll header is still not built! 129 data -> data 130 131 Resume 132 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 133 134 135 On transmit: 136 ------------ 137 138 dev->hard_header != NULL 139 mac_header -> ll header 140 data -> ll header 141 142 dev->hard_header == NULL (ll header is added by device, we cannot control it) 143 mac_header -> data 144 data -> data 145 146 We should set nh.raw on output to correct posistion, 147 packet classifier depends on it. 148 */ 149 150 /* Private packet socket structures. */ 151 152 /* identical to struct packet_mreq except it has 153 * a longer address field. 154 */ 155 struct packet_mreq_max { 156 int mr_ifindex; 157 unsigned short mr_type; 158 unsigned short mr_alen; 159 unsigned char mr_address[MAX_ADDR_LEN]; 160 }; 161 162 union tpacket_uhdr { 163 struct tpacket_hdr *h1; 164 struct tpacket2_hdr *h2; 165 struct tpacket3_hdr *h3; 166 void *raw; 167 }; 168 169 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 170 int closing, int tx_ring); 171 172 #define V3_ALIGNMENT (8) 173 174 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 175 176 #define BLK_PLUS_PRIV(sz_of_priv) \ 177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 178 179 #define PGV_FROM_VMALLOC 1 180 181 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 182 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 183 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 184 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 185 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 186 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 187 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 188 189 struct packet_sock; 190 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 192 struct packet_type *pt, struct net_device *orig_dev); 193 194 static void *packet_previous_frame(struct packet_sock *po, 195 struct packet_ring_buffer *rb, 196 int status); 197 static void packet_increment_head(struct packet_ring_buffer *buff); 198 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 199 struct tpacket_block_desc *); 200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 201 struct packet_sock *); 202 static void prb_retire_current_block(struct tpacket_kbdq_core *, 203 struct packet_sock *, unsigned int status); 204 static int prb_queue_frozen(struct tpacket_kbdq_core *); 205 static void prb_open_block(struct tpacket_kbdq_core *, 206 struct tpacket_block_desc *); 207 static void prb_retire_rx_blk_timer_expired(unsigned long); 208 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 209 static void prb_init_blk_timer(struct packet_sock *, 210 struct tpacket_kbdq_core *, 211 void (*func) (unsigned long)); 212 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 213 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 214 struct tpacket3_hdr *); 215 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 216 struct tpacket3_hdr *); 217 static void packet_flush_mclist(struct sock *sk); 218 219 struct packet_skb_cb { 220 union { 221 struct sockaddr_pkt pkt; 222 union { 223 /* Trick: alias skb original length with 224 * ll.sll_family and ll.protocol in order 225 * to save room. 226 */ 227 unsigned int origlen; 228 struct sockaddr_ll ll; 229 }; 230 } sa; 231 }; 232 233 #define vio_le() virtio_legacy_is_little_endian() 234 235 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 236 237 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 238 #define GET_PBLOCK_DESC(x, bid) \ 239 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 240 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 241 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 242 #define GET_NEXT_PRB_BLK_NUM(x) \ 243 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 244 ((x)->kactive_blk_num+1) : 0) 245 246 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 247 static void __fanout_link(struct sock *sk, struct packet_sock *po); 248 249 static int packet_direct_xmit(struct sk_buff *skb) 250 { 251 struct net_device *dev = skb->dev; 252 netdev_features_t features; 253 struct netdev_queue *txq; 254 int ret = NETDEV_TX_BUSY; 255 256 if (unlikely(!netif_running(dev) || 257 !netif_carrier_ok(dev))) 258 goto drop; 259 260 features = netif_skb_features(skb); 261 if (skb_needs_linearize(skb, features) && 262 __skb_linearize(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(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 default: 413 WARN(1, "TPACKET version not supported.\n"); 414 BUG(); 415 } 416 417 smp_wmb(); 418 } 419 420 static int __packet_get_status(struct packet_sock *po, void *frame) 421 { 422 union tpacket_uhdr h; 423 424 smp_rmb(); 425 426 h.raw = frame; 427 switch (po->tp_version) { 428 case TPACKET_V1: 429 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 430 return h.h1->tp_status; 431 case TPACKET_V2: 432 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 433 return h.h2->tp_status; 434 case TPACKET_V3: 435 default: 436 WARN(1, "TPACKET version not supported.\n"); 437 BUG(); 438 return 0; 439 } 440 } 441 442 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 443 unsigned int flags) 444 { 445 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 446 447 if (shhwtstamps && 448 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 449 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 450 return TP_STATUS_TS_RAW_HARDWARE; 451 452 if (ktime_to_timespec_cond(skb->tstamp, ts)) 453 return TP_STATUS_TS_SOFTWARE; 454 455 return 0; 456 } 457 458 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 459 struct sk_buff *skb) 460 { 461 union tpacket_uhdr h; 462 struct timespec ts; 463 __u32 ts_status; 464 465 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 466 return 0; 467 468 h.raw = frame; 469 switch (po->tp_version) { 470 case TPACKET_V1: 471 h.h1->tp_sec = ts.tv_sec; 472 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 473 break; 474 case TPACKET_V2: 475 h.h2->tp_sec = ts.tv_sec; 476 h.h2->tp_nsec = ts.tv_nsec; 477 break; 478 case TPACKET_V3: 479 default: 480 WARN(1, "TPACKET version not supported.\n"); 481 BUG(); 482 } 483 484 /* one flush is safe, as both fields always lie on the same cacheline */ 485 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 486 smp_wmb(); 487 488 return ts_status; 489 } 490 491 static void *packet_lookup_frame(struct packet_sock *po, 492 struct packet_ring_buffer *rb, 493 unsigned int position, 494 int status) 495 { 496 unsigned int pg_vec_pos, frame_offset; 497 union tpacket_uhdr h; 498 499 pg_vec_pos = position / rb->frames_per_block; 500 frame_offset = position % rb->frames_per_block; 501 502 h.raw = rb->pg_vec[pg_vec_pos].buffer + 503 (frame_offset * rb->frame_size); 504 505 if (status != __packet_get_status(po, h.raw)) 506 return NULL; 507 508 return h.raw; 509 } 510 511 static void *packet_current_frame(struct packet_sock *po, 512 struct packet_ring_buffer *rb, 513 int status) 514 { 515 return packet_lookup_frame(po, rb, rb->head, status); 516 } 517 518 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 519 { 520 del_timer_sync(&pkc->retire_blk_timer); 521 } 522 523 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 524 struct sk_buff_head *rb_queue) 525 { 526 struct tpacket_kbdq_core *pkc; 527 528 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 529 530 spin_lock_bh(&rb_queue->lock); 531 pkc->delete_blk_timer = 1; 532 spin_unlock_bh(&rb_queue->lock); 533 534 prb_del_retire_blk_timer(pkc); 535 } 536 537 static void prb_init_blk_timer(struct packet_sock *po, 538 struct tpacket_kbdq_core *pkc, 539 void (*func) (unsigned long)) 540 { 541 init_timer(&pkc->retire_blk_timer); 542 pkc->retire_blk_timer.data = (long)po; 543 pkc->retire_blk_timer.function = func; 544 pkc->retire_blk_timer.expires = jiffies; 545 } 546 547 static void prb_setup_retire_blk_timer(struct packet_sock *po) 548 { 549 struct tpacket_kbdq_core *pkc; 550 551 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 552 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 553 } 554 555 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 556 int blk_size_in_bytes) 557 { 558 struct net_device *dev; 559 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 560 struct ethtool_cmd ecmd; 561 int err; 562 u32 speed; 563 564 rtnl_lock(); 565 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 566 if (unlikely(!dev)) { 567 rtnl_unlock(); 568 return DEFAULT_PRB_RETIRE_TOV; 569 } 570 err = __ethtool_get_settings(dev, &ecmd); 571 speed = ethtool_cmd_speed(&ecmd); 572 rtnl_unlock(); 573 if (!err) { 574 /* 575 * If the link speed is so slow you don't really 576 * need to worry about perf anyways 577 */ 578 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 579 return DEFAULT_PRB_RETIRE_TOV; 580 } else { 581 msec = 1; 582 div = speed / 1000; 583 } 584 } 585 586 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 587 588 if (div) 589 mbits /= div; 590 591 tmo = mbits * msec; 592 593 if (div) 594 return tmo+1; 595 return tmo; 596 } 597 598 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 599 union tpacket_req_u *req_u) 600 { 601 p1->feature_req_word = req_u->req3.tp_feature_req_word; 602 } 603 604 static void init_prb_bdqc(struct packet_sock *po, 605 struct packet_ring_buffer *rb, 606 struct pgv *pg_vec, 607 union tpacket_req_u *req_u) 608 { 609 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 610 struct tpacket_block_desc *pbd; 611 612 memset(p1, 0x0, sizeof(*p1)); 613 614 p1->knxt_seq_num = 1; 615 p1->pkbdq = pg_vec; 616 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 617 p1->pkblk_start = pg_vec[0].buffer; 618 p1->kblk_size = req_u->req3.tp_block_size; 619 p1->knum_blocks = req_u->req3.tp_block_nr; 620 p1->hdrlen = po->tp_hdrlen; 621 p1->version = po->tp_version; 622 p1->last_kactive_blk_num = 0; 623 po->stats.stats3.tp_freeze_q_cnt = 0; 624 if (req_u->req3.tp_retire_blk_tov) 625 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 626 else 627 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 628 req_u->req3.tp_block_size); 629 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 630 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 631 632 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 633 prb_init_ft_ops(p1, req_u); 634 prb_setup_retire_blk_timer(po); 635 prb_open_block(p1, pbd); 636 } 637 638 /* Do NOT update the last_blk_num first. 639 * Assumes sk_buff_head lock is held. 640 */ 641 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 642 { 643 mod_timer(&pkc->retire_blk_timer, 644 jiffies + pkc->tov_in_jiffies); 645 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 646 } 647 648 /* 649 * Timer logic: 650 * 1) We refresh the timer only when we open a block. 651 * By doing this we don't waste cycles refreshing the timer 652 * on packet-by-packet basis. 653 * 654 * With a 1MB block-size, on a 1Gbps line, it will take 655 * i) ~8 ms to fill a block + ii) memcpy etc. 656 * In this cut we are not accounting for the memcpy time. 657 * 658 * So, if the user sets the 'tmo' to 10ms then the timer 659 * will never fire while the block is still getting filled 660 * (which is what we want). However, the user could choose 661 * to close a block early and that's fine. 662 * 663 * But when the timer does fire, we check whether or not to refresh it. 664 * Since the tmo granularity is in msecs, it is not too expensive 665 * to refresh the timer, lets say every '8' msecs. 666 * Either the user can set the 'tmo' or we can derive it based on 667 * a) line-speed and b) block-size. 668 * prb_calc_retire_blk_tmo() calculates the tmo. 669 * 670 */ 671 static void prb_retire_rx_blk_timer_expired(unsigned long data) 672 { 673 struct packet_sock *po = (struct packet_sock *)data; 674 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 675 unsigned int frozen; 676 struct tpacket_block_desc *pbd; 677 678 spin_lock(&po->sk.sk_receive_queue.lock); 679 680 frozen = prb_queue_frozen(pkc); 681 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 682 683 if (unlikely(pkc->delete_blk_timer)) 684 goto out; 685 686 /* We only need to plug the race when the block is partially filled. 687 * tpacket_rcv: 688 * lock(); increment BLOCK_NUM_PKTS; unlock() 689 * copy_bits() is in progress ... 690 * timer fires on other cpu: 691 * we can't retire the current block because copy_bits 692 * is in progress. 693 * 694 */ 695 if (BLOCK_NUM_PKTS(pbd)) { 696 while (atomic_read(&pkc->blk_fill_in_prog)) { 697 /* Waiting for skb_copy_bits to finish... */ 698 cpu_relax(); 699 } 700 } 701 702 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 703 if (!frozen) { 704 if (!BLOCK_NUM_PKTS(pbd)) { 705 /* An empty block. Just refresh the timer. */ 706 goto refresh_timer; 707 } 708 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 709 if (!prb_dispatch_next_block(pkc, po)) 710 goto refresh_timer; 711 else 712 goto out; 713 } else { 714 /* Case 1. Queue was frozen because user-space was 715 * lagging behind. 716 */ 717 if (prb_curr_blk_in_use(pkc, pbd)) { 718 /* 719 * Ok, user-space is still behind. 720 * So just refresh the timer. 721 */ 722 goto refresh_timer; 723 } else { 724 /* Case 2. queue was frozen,user-space caught up, 725 * now the link went idle && the timer fired. 726 * We don't have a block to close.So we open this 727 * block and restart the timer. 728 * opening a block thaws the queue,restarts timer 729 * Thawing/timer-refresh is a side effect. 730 */ 731 prb_open_block(pkc, pbd); 732 goto out; 733 } 734 } 735 } 736 737 refresh_timer: 738 _prb_refresh_rx_retire_blk_timer(pkc); 739 740 out: 741 spin_unlock(&po->sk.sk_receive_queue.lock); 742 } 743 744 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 745 struct tpacket_block_desc *pbd1, __u32 status) 746 { 747 /* Flush everything minus the block header */ 748 749 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 750 u8 *start, *end; 751 752 start = (u8 *)pbd1; 753 754 /* Skip the block header(we know header WILL fit in 4K) */ 755 start += PAGE_SIZE; 756 757 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 758 for (; start < end; start += PAGE_SIZE) 759 flush_dcache_page(pgv_to_page(start)); 760 761 smp_wmb(); 762 #endif 763 764 /* Now update the block status. */ 765 766 BLOCK_STATUS(pbd1) = status; 767 768 /* Flush the block header */ 769 770 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 771 start = (u8 *)pbd1; 772 flush_dcache_page(pgv_to_page(start)); 773 774 smp_wmb(); 775 #endif 776 } 777 778 /* 779 * Side effect: 780 * 781 * 1) flush the block 782 * 2) Increment active_blk_num 783 * 784 * Note:We DONT refresh the timer on purpose. 785 * Because almost always the next block will be opened. 786 */ 787 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 788 struct tpacket_block_desc *pbd1, 789 struct packet_sock *po, unsigned int stat) 790 { 791 __u32 status = TP_STATUS_USER | stat; 792 793 struct tpacket3_hdr *last_pkt; 794 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 795 struct sock *sk = &po->sk; 796 797 if (po->stats.stats3.tp_drops) 798 status |= TP_STATUS_LOSING; 799 800 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 801 last_pkt->tp_next_offset = 0; 802 803 /* Get the ts of the last pkt */ 804 if (BLOCK_NUM_PKTS(pbd1)) { 805 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 806 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 807 } else { 808 /* Ok, we tmo'd - so get the current time. 809 * 810 * It shouldn't really happen as we don't close empty 811 * blocks. See prb_retire_rx_blk_timer_expired(). 812 */ 813 struct timespec ts; 814 getnstimeofday(&ts); 815 h1->ts_last_pkt.ts_sec = ts.tv_sec; 816 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 817 } 818 819 smp_wmb(); 820 821 /* Flush the block */ 822 prb_flush_block(pkc1, pbd1, status); 823 824 sk->sk_data_ready(sk); 825 826 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 827 } 828 829 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 830 { 831 pkc->reset_pending_on_curr_blk = 0; 832 } 833 834 /* 835 * Side effect of opening a block: 836 * 837 * 1) prb_queue is thawed. 838 * 2) retire_blk_timer is refreshed. 839 * 840 */ 841 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 842 struct tpacket_block_desc *pbd1) 843 { 844 struct timespec ts; 845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 846 847 smp_rmb(); 848 849 /* We could have just memset this but we will lose the 850 * flexibility of making the priv area sticky 851 */ 852 853 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 854 BLOCK_NUM_PKTS(pbd1) = 0; 855 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 856 857 getnstimeofday(&ts); 858 859 h1->ts_first_pkt.ts_sec = ts.tv_sec; 860 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 861 862 pkc1->pkblk_start = (char *)pbd1; 863 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 864 865 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 866 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 867 868 pbd1->version = pkc1->version; 869 pkc1->prev = pkc1->nxt_offset; 870 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 871 872 prb_thaw_queue(pkc1); 873 _prb_refresh_rx_retire_blk_timer(pkc1); 874 875 smp_wmb(); 876 } 877 878 /* 879 * Queue freeze logic: 880 * 1) Assume tp_block_nr = 8 blocks. 881 * 2) At time 't0', user opens Rx ring. 882 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 883 * 4) user-space is either sleeping or processing block '0'. 884 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 885 * it will close block-7,loop around and try to fill block '0'. 886 * call-flow: 887 * __packet_lookup_frame_in_block 888 * prb_retire_current_block() 889 * prb_dispatch_next_block() 890 * |->(BLOCK_STATUS == USER) evaluates to true 891 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 892 * 6) Now there are two cases: 893 * 6.1) Link goes idle right after the queue is frozen. 894 * But remember, the last open_block() refreshed the timer. 895 * When this timer expires,it will refresh itself so that we can 896 * re-open block-0 in near future. 897 * 6.2) Link is busy and keeps on receiving packets. This is a simple 898 * case and __packet_lookup_frame_in_block will check if block-0 899 * is free and can now be re-used. 900 */ 901 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 902 struct packet_sock *po) 903 { 904 pkc->reset_pending_on_curr_blk = 1; 905 po->stats.stats3.tp_freeze_q_cnt++; 906 } 907 908 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 909 910 /* 911 * If the next block is free then we will dispatch it 912 * and return a good offset. 913 * Else, we will freeze the queue. 914 * So, caller must check the return value. 915 */ 916 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 917 struct packet_sock *po) 918 { 919 struct tpacket_block_desc *pbd; 920 921 smp_rmb(); 922 923 /* 1. Get current block num */ 924 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 925 926 /* 2. If this block is currently in_use then freeze the queue */ 927 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 928 prb_freeze_queue(pkc, po); 929 return NULL; 930 } 931 932 /* 933 * 3. 934 * open this block and return the offset where the first packet 935 * needs to get stored. 936 */ 937 prb_open_block(pkc, pbd); 938 return (void *)pkc->nxt_offset; 939 } 940 941 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 942 struct packet_sock *po, unsigned int status) 943 { 944 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 945 946 /* retire/close the current block */ 947 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 948 /* 949 * Plug the case where copy_bits() is in progress on 950 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 951 * have space to copy the pkt in the current block and 952 * called prb_retire_current_block() 953 * 954 * We don't need to worry about the TMO case because 955 * the timer-handler already handled this case. 956 */ 957 if (!(status & TP_STATUS_BLK_TMO)) { 958 while (atomic_read(&pkc->blk_fill_in_prog)) { 959 /* Waiting for skb_copy_bits to finish... */ 960 cpu_relax(); 961 } 962 } 963 prb_close_block(pkc, pbd, po, status); 964 return; 965 } 966 } 967 968 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 969 struct tpacket_block_desc *pbd) 970 { 971 return TP_STATUS_USER & BLOCK_STATUS(pbd); 972 } 973 974 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 975 { 976 return pkc->reset_pending_on_curr_blk; 977 } 978 979 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 980 { 981 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 982 atomic_dec(&pkc->blk_fill_in_prog); 983 } 984 985 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 986 struct tpacket3_hdr *ppd) 987 { 988 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 989 } 990 991 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 992 struct tpacket3_hdr *ppd) 993 { 994 ppd->hv1.tp_rxhash = 0; 995 } 996 997 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 998 struct tpacket3_hdr *ppd) 999 { 1000 if (skb_vlan_tag_present(pkc->skb)) { 1001 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1002 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1003 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1004 } else { 1005 ppd->hv1.tp_vlan_tci = 0; 1006 ppd->hv1.tp_vlan_tpid = 0; 1007 ppd->tp_status = TP_STATUS_AVAILABLE; 1008 } 1009 } 1010 1011 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1012 struct tpacket3_hdr *ppd) 1013 { 1014 ppd->hv1.tp_padding = 0; 1015 prb_fill_vlan_info(pkc, ppd); 1016 1017 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1018 prb_fill_rxhash(pkc, ppd); 1019 else 1020 prb_clear_rxhash(pkc, ppd); 1021 } 1022 1023 static void prb_fill_curr_block(char *curr, 1024 struct tpacket_kbdq_core *pkc, 1025 struct tpacket_block_desc *pbd, 1026 unsigned int len) 1027 { 1028 struct tpacket3_hdr *ppd; 1029 1030 ppd = (struct tpacket3_hdr *)curr; 1031 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1032 pkc->prev = curr; 1033 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1034 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1035 BLOCK_NUM_PKTS(pbd) += 1; 1036 atomic_inc(&pkc->blk_fill_in_prog); 1037 prb_run_all_ft_ops(pkc, ppd); 1038 } 1039 1040 /* Assumes caller has the sk->rx_queue.lock */ 1041 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1042 struct sk_buff *skb, 1043 int status, 1044 unsigned int len 1045 ) 1046 { 1047 struct tpacket_kbdq_core *pkc; 1048 struct tpacket_block_desc *pbd; 1049 char *curr, *end; 1050 1051 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1052 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1053 1054 /* Queue is frozen when user space is lagging behind */ 1055 if (prb_queue_frozen(pkc)) { 1056 /* 1057 * Check if that last block which caused the queue to freeze, 1058 * is still in_use by user-space. 1059 */ 1060 if (prb_curr_blk_in_use(pkc, pbd)) { 1061 /* Can't record this packet */ 1062 return NULL; 1063 } else { 1064 /* 1065 * Ok, the block was released by user-space. 1066 * Now let's open that block. 1067 * opening a block also thaws the queue. 1068 * Thawing is a side effect. 1069 */ 1070 prb_open_block(pkc, pbd); 1071 } 1072 } 1073 1074 smp_mb(); 1075 curr = pkc->nxt_offset; 1076 pkc->skb = skb; 1077 end = (char *)pbd + pkc->kblk_size; 1078 1079 /* first try the current block */ 1080 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1081 prb_fill_curr_block(curr, pkc, pbd, len); 1082 return (void *)curr; 1083 } 1084 1085 /* Ok, close the current block */ 1086 prb_retire_current_block(pkc, po, 0); 1087 1088 /* Now, try to dispatch the next block */ 1089 curr = (char *)prb_dispatch_next_block(pkc, po); 1090 if (curr) { 1091 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1092 prb_fill_curr_block(curr, pkc, pbd, len); 1093 return (void *)curr; 1094 } 1095 1096 /* 1097 * No free blocks are available.user_space hasn't caught up yet. 1098 * Queue was just frozen and now this packet will get dropped. 1099 */ 1100 return NULL; 1101 } 1102 1103 static void *packet_current_rx_frame(struct packet_sock *po, 1104 struct sk_buff *skb, 1105 int status, unsigned int len) 1106 { 1107 char *curr = NULL; 1108 switch (po->tp_version) { 1109 case TPACKET_V1: 1110 case TPACKET_V2: 1111 curr = packet_lookup_frame(po, &po->rx_ring, 1112 po->rx_ring.head, status); 1113 return curr; 1114 case TPACKET_V3: 1115 return __packet_lookup_frame_in_block(po, skb, status, len); 1116 default: 1117 WARN(1, "TPACKET version not supported\n"); 1118 BUG(); 1119 return NULL; 1120 } 1121 } 1122 1123 static void *prb_lookup_block(struct packet_sock *po, 1124 struct packet_ring_buffer *rb, 1125 unsigned int idx, 1126 int status) 1127 { 1128 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1129 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1130 1131 if (status != BLOCK_STATUS(pbd)) 1132 return NULL; 1133 return pbd; 1134 } 1135 1136 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1137 { 1138 unsigned int prev; 1139 if (rb->prb_bdqc.kactive_blk_num) 1140 prev = rb->prb_bdqc.kactive_blk_num-1; 1141 else 1142 prev = rb->prb_bdqc.knum_blocks-1; 1143 return prev; 1144 } 1145 1146 /* Assumes caller has held the rx_queue.lock */ 1147 static void *__prb_previous_block(struct packet_sock *po, 1148 struct packet_ring_buffer *rb, 1149 int status) 1150 { 1151 unsigned int previous = prb_previous_blk_num(rb); 1152 return prb_lookup_block(po, rb, previous, status); 1153 } 1154 1155 static void *packet_previous_rx_frame(struct packet_sock *po, 1156 struct packet_ring_buffer *rb, 1157 int status) 1158 { 1159 if (po->tp_version <= TPACKET_V2) 1160 return packet_previous_frame(po, rb, status); 1161 1162 return __prb_previous_block(po, rb, status); 1163 } 1164 1165 static void packet_increment_rx_head(struct packet_sock *po, 1166 struct packet_ring_buffer *rb) 1167 { 1168 switch (po->tp_version) { 1169 case TPACKET_V1: 1170 case TPACKET_V2: 1171 return packet_increment_head(rb); 1172 case TPACKET_V3: 1173 default: 1174 WARN(1, "TPACKET version not supported.\n"); 1175 BUG(); 1176 return; 1177 } 1178 } 1179 1180 static void *packet_previous_frame(struct packet_sock *po, 1181 struct packet_ring_buffer *rb, 1182 int status) 1183 { 1184 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1185 return packet_lookup_frame(po, rb, previous, status); 1186 } 1187 1188 static void packet_increment_head(struct packet_ring_buffer *buff) 1189 { 1190 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1191 } 1192 1193 static void packet_inc_pending(struct packet_ring_buffer *rb) 1194 { 1195 this_cpu_inc(*rb->pending_refcnt); 1196 } 1197 1198 static void packet_dec_pending(struct packet_ring_buffer *rb) 1199 { 1200 this_cpu_dec(*rb->pending_refcnt); 1201 } 1202 1203 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1204 { 1205 unsigned int refcnt = 0; 1206 int cpu; 1207 1208 /* We don't use pending refcount in rx_ring. */ 1209 if (rb->pending_refcnt == NULL) 1210 return 0; 1211 1212 for_each_possible_cpu(cpu) 1213 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1214 1215 return refcnt; 1216 } 1217 1218 static int packet_alloc_pending(struct packet_sock *po) 1219 { 1220 po->rx_ring.pending_refcnt = NULL; 1221 1222 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1223 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1224 return -ENOBUFS; 1225 1226 return 0; 1227 } 1228 1229 static void packet_free_pending(struct packet_sock *po) 1230 { 1231 free_percpu(po->tx_ring.pending_refcnt); 1232 } 1233 1234 #define ROOM_POW_OFF 2 1235 #define ROOM_NONE 0x0 1236 #define ROOM_LOW 0x1 1237 #define ROOM_NORMAL 0x2 1238 1239 static bool __tpacket_has_room(struct packet_sock *po, int pow_off) 1240 { 1241 int idx, len; 1242 1243 len = po->rx_ring.frame_max + 1; 1244 idx = po->rx_ring.head; 1245 if (pow_off) 1246 idx += len >> pow_off; 1247 if (idx >= len) 1248 idx -= len; 1249 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1250 } 1251 1252 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off) 1253 { 1254 int idx, len; 1255 1256 len = po->rx_ring.prb_bdqc.knum_blocks; 1257 idx = po->rx_ring.prb_bdqc.kactive_blk_num; 1258 if (pow_off) 1259 idx += len >> pow_off; 1260 if (idx >= len) 1261 idx -= len; 1262 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1263 } 1264 1265 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1266 { 1267 struct sock *sk = &po->sk; 1268 int ret = ROOM_NONE; 1269 1270 if (po->prot_hook.func != tpacket_rcv) { 1271 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1272 - (skb ? skb->truesize : 0); 1273 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF)) 1274 return ROOM_NORMAL; 1275 else if (avail > 0) 1276 return ROOM_LOW; 1277 else 1278 return ROOM_NONE; 1279 } 1280 1281 if (po->tp_version == TPACKET_V3) { 1282 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1283 ret = ROOM_NORMAL; 1284 else if (__tpacket_v3_has_room(po, 0)) 1285 ret = ROOM_LOW; 1286 } else { 1287 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1288 ret = ROOM_NORMAL; 1289 else if (__tpacket_has_room(po, 0)) 1290 ret = ROOM_LOW; 1291 } 1292 1293 return ret; 1294 } 1295 1296 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1297 { 1298 int ret; 1299 bool has_room; 1300 1301 spin_lock_bh(&po->sk.sk_receive_queue.lock); 1302 ret = __packet_rcv_has_room(po, skb); 1303 has_room = ret == ROOM_NORMAL; 1304 if (po->pressure == has_room) 1305 po->pressure = !has_room; 1306 spin_unlock_bh(&po->sk.sk_receive_queue.lock); 1307 1308 return ret; 1309 } 1310 1311 static void packet_sock_destruct(struct sock *sk) 1312 { 1313 skb_queue_purge(&sk->sk_error_queue); 1314 1315 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1316 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1317 1318 if (!sock_flag(sk, SOCK_DEAD)) { 1319 pr_err("Attempt to release alive packet socket: %p\n", sk); 1320 return; 1321 } 1322 1323 sk_refcnt_debug_dec(sk); 1324 } 1325 1326 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1327 { 1328 u32 rxhash; 1329 int i, count = 0; 1330 1331 rxhash = skb_get_hash(skb); 1332 for (i = 0; i < ROLLOVER_HLEN; i++) 1333 if (po->rollover->history[i] == rxhash) 1334 count++; 1335 1336 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash; 1337 return count > (ROLLOVER_HLEN >> 1); 1338 } 1339 1340 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1341 struct sk_buff *skb, 1342 unsigned int num) 1343 { 1344 return reciprocal_scale(skb_get_hash(skb), num); 1345 } 1346 1347 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1348 struct sk_buff *skb, 1349 unsigned int num) 1350 { 1351 unsigned int val = atomic_inc_return(&f->rr_cur); 1352 1353 return val % num; 1354 } 1355 1356 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1357 struct sk_buff *skb, 1358 unsigned int num) 1359 { 1360 return smp_processor_id() % num; 1361 } 1362 1363 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1364 struct sk_buff *skb, 1365 unsigned int num) 1366 { 1367 return prandom_u32_max(num); 1368 } 1369 1370 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1371 struct sk_buff *skb, 1372 unsigned int idx, bool try_self, 1373 unsigned int num) 1374 { 1375 struct packet_sock *po, *po_next, *po_skip = NULL; 1376 unsigned int i, j, room = ROOM_NONE; 1377 1378 po = pkt_sk(f->arr[idx]); 1379 1380 if (try_self) { 1381 room = packet_rcv_has_room(po, skb); 1382 if (room == ROOM_NORMAL || 1383 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1384 return idx; 1385 po_skip = po; 1386 } 1387 1388 i = j = min_t(int, po->rollover->sock, num - 1); 1389 do { 1390 po_next = pkt_sk(f->arr[i]); 1391 if (po_next != po_skip && !po_next->pressure && 1392 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1393 if (i != j) 1394 po->rollover->sock = i; 1395 atomic_long_inc(&po->rollover->num); 1396 if (room == ROOM_LOW) 1397 atomic_long_inc(&po->rollover->num_huge); 1398 return i; 1399 } 1400 1401 if (++i == num) 1402 i = 0; 1403 } while (i != j); 1404 1405 atomic_long_inc(&po->rollover->num_failed); 1406 return idx; 1407 } 1408 1409 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1410 struct sk_buff *skb, 1411 unsigned int num) 1412 { 1413 return skb_get_queue_mapping(skb) % num; 1414 } 1415 1416 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1417 struct sk_buff *skb, 1418 unsigned int num) 1419 { 1420 struct bpf_prog *prog; 1421 unsigned int ret = 0; 1422 1423 rcu_read_lock(); 1424 prog = rcu_dereference(f->bpf_prog); 1425 if (prog) 1426 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1427 rcu_read_unlock(); 1428 1429 return ret; 1430 } 1431 1432 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1433 { 1434 return f->flags & (flag >> 8); 1435 } 1436 1437 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1438 struct packet_type *pt, struct net_device *orig_dev) 1439 { 1440 struct packet_fanout *f = pt->af_packet_priv; 1441 unsigned int num = READ_ONCE(f->num_members); 1442 struct net *net = read_pnet(&f->net); 1443 struct packet_sock *po; 1444 unsigned int idx; 1445 1446 if (!net_eq(dev_net(dev), net) || !num) { 1447 kfree_skb(skb); 1448 return 0; 1449 } 1450 1451 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1452 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1453 if (!skb) 1454 return 0; 1455 } 1456 switch (f->type) { 1457 case PACKET_FANOUT_HASH: 1458 default: 1459 idx = fanout_demux_hash(f, skb, num); 1460 break; 1461 case PACKET_FANOUT_LB: 1462 idx = fanout_demux_lb(f, skb, num); 1463 break; 1464 case PACKET_FANOUT_CPU: 1465 idx = fanout_demux_cpu(f, skb, num); 1466 break; 1467 case PACKET_FANOUT_RND: 1468 idx = fanout_demux_rnd(f, skb, num); 1469 break; 1470 case PACKET_FANOUT_QM: 1471 idx = fanout_demux_qm(f, skb, num); 1472 break; 1473 case PACKET_FANOUT_ROLLOVER: 1474 idx = fanout_demux_rollover(f, skb, 0, false, num); 1475 break; 1476 case PACKET_FANOUT_CBPF: 1477 case PACKET_FANOUT_EBPF: 1478 idx = fanout_demux_bpf(f, skb, num); 1479 break; 1480 } 1481 1482 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1483 idx = fanout_demux_rollover(f, skb, idx, true, num); 1484 1485 po = pkt_sk(f->arr[idx]); 1486 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1487 } 1488 1489 DEFINE_MUTEX(fanout_mutex); 1490 EXPORT_SYMBOL_GPL(fanout_mutex); 1491 static LIST_HEAD(fanout_list); 1492 1493 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1494 { 1495 struct packet_fanout *f = po->fanout; 1496 1497 spin_lock(&f->lock); 1498 f->arr[f->num_members] = sk; 1499 smp_wmb(); 1500 f->num_members++; 1501 spin_unlock(&f->lock); 1502 } 1503 1504 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1505 { 1506 struct packet_fanout *f = po->fanout; 1507 int i; 1508 1509 spin_lock(&f->lock); 1510 for (i = 0; i < f->num_members; i++) { 1511 if (f->arr[i] == sk) 1512 break; 1513 } 1514 BUG_ON(i >= f->num_members); 1515 f->arr[i] = f->arr[f->num_members - 1]; 1516 f->num_members--; 1517 spin_unlock(&f->lock); 1518 } 1519 1520 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1521 { 1522 if (sk->sk_family != PF_PACKET) 1523 return false; 1524 1525 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1526 } 1527 1528 static void fanout_init_data(struct packet_fanout *f) 1529 { 1530 switch (f->type) { 1531 case PACKET_FANOUT_LB: 1532 atomic_set(&f->rr_cur, 0); 1533 break; 1534 case PACKET_FANOUT_CBPF: 1535 case PACKET_FANOUT_EBPF: 1536 RCU_INIT_POINTER(f->bpf_prog, NULL); 1537 break; 1538 } 1539 } 1540 1541 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1542 { 1543 struct bpf_prog *old; 1544 1545 spin_lock(&f->lock); 1546 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1547 rcu_assign_pointer(f->bpf_prog, new); 1548 spin_unlock(&f->lock); 1549 1550 if (old) { 1551 synchronize_net(); 1552 bpf_prog_destroy(old); 1553 } 1554 } 1555 1556 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data, 1557 unsigned int len) 1558 { 1559 struct bpf_prog *new; 1560 struct sock_fprog fprog; 1561 int ret; 1562 1563 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1564 return -EPERM; 1565 if (len != sizeof(fprog)) 1566 return -EINVAL; 1567 if (copy_from_user(&fprog, data, len)) 1568 return -EFAULT; 1569 1570 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1571 if (ret) 1572 return ret; 1573 1574 __fanout_set_data_bpf(po->fanout, new); 1575 return 0; 1576 } 1577 1578 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data, 1579 unsigned int len) 1580 { 1581 struct bpf_prog *new; 1582 u32 fd; 1583 1584 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1585 return -EPERM; 1586 if (len != sizeof(fd)) 1587 return -EINVAL; 1588 if (copy_from_user(&fd, data, len)) 1589 return -EFAULT; 1590 1591 new = bpf_prog_get(fd); 1592 if (IS_ERR(new)) 1593 return PTR_ERR(new); 1594 if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) { 1595 bpf_prog_put(new); 1596 return -EINVAL; 1597 } 1598 1599 __fanout_set_data_bpf(po->fanout, new); 1600 return 0; 1601 } 1602 1603 static int fanout_set_data(struct packet_sock *po, char __user *data, 1604 unsigned int len) 1605 { 1606 switch (po->fanout->type) { 1607 case PACKET_FANOUT_CBPF: 1608 return fanout_set_data_cbpf(po, data, len); 1609 case PACKET_FANOUT_EBPF: 1610 return fanout_set_data_ebpf(po, data, len); 1611 default: 1612 return -EINVAL; 1613 }; 1614 } 1615 1616 static void fanout_release_data(struct packet_fanout *f) 1617 { 1618 switch (f->type) { 1619 case PACKET_FANOUT_CBPF: 1620 case PACKET_FANOUT_EBPF: 1621 __fanout_set_data_bpf(f, NULL); 1622 }; 1623 } 1624 1625 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1626 { 1627 struct packet_sock *po = pkt_sk(sk); 1628 struct packet_fanout *f, *match; 1629 u8 type = type_flags & 0xff; 1630 u8 flags = type_flags >> 8; 1631 int err; 1632 1633 switch (type) { 1634 case PACKET_FANOUT_ROLLOVER: 1635 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1636 return -EINVAL; 1637 case PACKET_FANOUT_HASH: 1638 case PACKET_FANOUT_LB: 1639 case PACKET_FANOUT_CPU: 1640 case PACKET_FANOUT_RND: 1641 case PACKET_FANOUT_QM: 1642 case PACKET_FANOUT_CBPF: 1643 case PACKET_FANOUT_EBPF: 1644 break; 1645 default: 1646 return -EINVAL; 1647 } 1648 1649 if (!po->running) 1650 return -EINVAL; 1651 1652 if (po->fanout) 1653 return -EALREADY; 1654 1655 if (type == PACKET_FANOUT_ROLLOVER || 1656 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1657 po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL); 1658 if (!po->rollover) 1659 return -ENOMEM; 1660 atomic_long_set(&po->rollover->num, 0); 1661 atomic_long_set(&po->rollover->num_huge, 0); 1662 atomic_long_set(&po->rollover->num_failed, 0); 1663 } 1664 1665 mutex_lock(&fanout_mutex); 1666 match = NULL; 1667 list_for_each_entry(f, &fanout_list, list) { 1668 if (f->id == id && 1669 read_pnet(&f->net) == sock_net(sk)) { 1670 match = f; 1671 break; 1672 } 1673 } 1674 err = -EINVAL; 1675 if (match && match->flags != flags) 1676 goto out; 1677 if (!match) { 1678 err = -ENOMEM; 1679 match = kzalloc(sizeof(*match), GFP_KERNEL); 1680 if (!match) 1681 goto out; 1682 write_pnet(&match->net, sock_net(sk)); 1683 match->id = id; 1684 match->type = type; 1685 match->flags = flags; 1686 INIT_LIST_HEAD(&match->list); 1687 spin_lock_init(&match->lock); 1688 atomic_set(&match->sk_ref, 0); 1689 fanout_init_data(match); 1690 match->prot_hook.type = po->prot_hook.type; 1691 match->prot_hook.dev = po->prot_hook.dev; 1692 match->prot_hook.func = packet_rcv_fanout; 1693 match->prot_hook.af_packet_priv = match; 1694 match->prot_hook.id_match = match_fanout_group; 1695 dev_add_pack(&match->prot_hook); 1696 list_add(&match->list, &fanout_list); 1697 } 1698 err = -EINVAL; 1699 if (match->type == type && 1700 match->prot_hook.type == po->prot_hook.type && 1701 match->prot_hook.dev == po->prot_hook.dev) { 1702 err = -ENOSPC; 1703 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1704 __dev_remove_pack(&po->prot_hook); 1705 po->fanout = match; 1706 atomic_inc(&match->sk_ref); 1707 __fanout_link(sk, po); 1708 err = 0; 1709 } 1710 } 1711 out: 1712 mutex_unlock(&fanout_mutex); 1713 if (err) { 1714 kfree(po->rollover); 1715 po->rollover = NULL; 1716 } 1717 return err; 1718 } 1719 1720 static void fanout_release(struct sock *sk) 1721 { 1722 struct packet_sock *po = pkt_sk(sk); 1723 struct packet_fanout *f; 1724 1725 f = po->fanout; 1726 if (!f) 1727 return; 1728 1729 mutex_lock(&fanout_mutex); 1730 po->fanout = NULL; 1731 1732 if (atomic_dec_and_test(&f->sk_ref)) { 1733 list_del(&f->list); 1734 dev_remove_pack(&f->prot_hook); 1735 fanout_release_data(f); 1736 kfree(f); 1737 } 1738 mutex_unlock(&fanout_mutex); 1739 1740 if (po->rollover) 1741 kfree_rcu(po->rollover, rcu); 1742 } 1743 1744 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1745 struct sk_buff *skb) 1746 { 1747 /* Earlier code assumed this would be a VLAN pkt, double-check 1748 * this now that we have the actual packet in hand. We can only 1749 * do this check on Ethernet devices. 1750 */ 1751 if (unlikely(dev->type != ARPHRD_ETHER)) 1752 return false; 1753 1754 skb_reset_mac_header(skb); 1755 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1756 } 1757 1758 static const struct proto_ops packet_ops; 1759 1760 static const struct proto_ops packet_ops_spkt; 1761 1762 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1763 struct packet_type *pt, struct net_device *orig_dev) 1764 { 1765 struct sock *sk; 1766 struct sockaddr_pkt *spkt; 1767 1768 /* 1769 * When we registered the protocol we saved the socket in the data 1770 * field for just this event. 1771 */ 1772 1773 sk = pt->af_packet_priv; 1774 1775 /* 1776 * Yank back the headers [hope the device set this 1777 * right or kerboom...] 1778 * 1779 * Incoming packets have ll header pulled, 1780 * push it back. 1781 * 1782 * For outgoing ones skb->data == skb_mac_header(skb) 1783 * so that this procedure is noop. 1784 */ 1785 1786 if (skb->pkt_type == PACKET_LOOPBACK) 1787 goto out; 1788 1789 if (!net_eq(dev_net(dev), sock_net(sk))) 1790 goto out; 1791 1792 skb = skb_share_check(skb, GFP_ATOMIC); 1793 if (skb == NULL) 1794 goto oom; 1795 1796 /* drop any routing info */ 1797 skb_dst_drop(skb); 1798 1799 /* drop conntrack reference */ 1800 nf_reset(skb); 1801 1802 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1803 1804 skb_push(skb, skb->data - skb_mac_header(skb)); 1805 1806 /* 1807 * The SOCK_PACKET socket receives _all_ frames. 1808 */ 1809 1810 spkt->spkt_family = dev->type; 1811 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1812 spkt->spkt_protocol = skb->protocol; 1813 1814 /* 1815 * Charge the memory to the socket. This is done specifically 1816 * to prevent sockets using all the memory up. 1817 */ 1818 1819 if (sock_queue_rcv_skb(sk, skb) == 0) 1820 return 0; 1821 1822 out: 1823 kfree_skb(skb); 1824 oom: 1825 return 0; 1826 } 1827 1828 1829 /* 1830 * Output a raw packet to a device layer. This bypasses all the other 1831 * protocol layers and you must therefore supply it with a complete frame 1832 */ 1833 1834 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1835 size_t len) 1836 { 1837 struct sock *sk = sock->sk; 1838 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1839 struct sk_buff *skb = NULL; 1840 struct net_device *dev; 1841 __be16 proto = 0; 1842 int err; 1843 int extra_len = 0; 1844 1845 /* 1846 * Get and verify the address. 1847 */ 1848 1849 if (saddr) { 1850 if (msg->msg_namelen < sizeof(struct sockaddr)) 1851 return -EINVAL; 1852 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1853 proto = saddr->spkt_protocol; 1854 } else 1855 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1856 1857 /* 1858 * Find the device first to size check it 1859 */ 1860 1861 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1862 retry: 1863 rcu_read_lock(); 1864 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1865 err = -ENODEV; 1866 if (dev == NULL) 1867 goto out_unlock; 1868 1869 err = -ENETDOWN; 1870 if (!(dev->flags & IFF_UP)) 1871 goto out_unlock; 1872 1873 /* 1874 * You may not queue a frame bigger than the mtu. This is the lowest level 1875 * raw protocol and you must do your own fragmentation at this level. 1876 */ 1877 1878 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1879 if (!netif_supports_nofcs(dev)) { 1880 err = -EPROTONOSUPPORT; 1881 goto out_unlock; 1882 } 1883 extra_len = 4; /* We're doing our own CRC */ 1884 } 1885 1886 err = -EMSGSIZE; 1887 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1888 goto out_unlock; 1889 1890 if (!skb) { 1891 size_t reserved = LL_RESERVED_SPACE(dev); 1892 int tlen = dev->needed_tailroom; 1893 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1894 1895 rcu_read_unlock(); 1896 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1897 if (skb == NULL) 1898 return -ENOBUFS; 1899 /* FIXME: Save some space for broken drivers that write a hard 1900 * header at transmission time by themselves. PPP is the notable 1901 * one here. This should really be fixed at the driver level. 1902 */ 1903 skb_reserve(skb, reserved); 1904 skb_reset_network_header(skb); 1905 1906 /* Try to align data part correctly */ 1907 if (hhlen) { 1908 skb->data -= hhlen; 1909 skb->tail -= hhlen; 1910 if (len < hhlen) 1911 skb_reset_network_header(skb); 1912 } 1913 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1914 if (err) 1915 goto out_free; 1916 goto retry; 1917 } 1918 1919 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 1920 !packet_extra_vlan_len_allowed(dev, skb)) { 1921 err = -EMSGSIZE; 1922 goto out_unlock; 1923 } 1924 1925 skb->protocol = proto; 1926 skb->dev = dev; 1927 skb->priority = sk->sk_priority; 1928 skb->mark = sk->sk_mark; 1929 1930 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1931 1932 if (unlikely(extra_len == 4)) 1933 skb->no_fcs = 1; 1934 1935 skb_probe_transport_header(skb, 0); 1936 1937 dev_queue_xmit(skb); 1938 rcu_read_unlock(); 1939 return len; 1940 1941 out_unlock: 1942 rcu_read_unlock(); 1943 out_free: 1944 kfree_skb(skb); 1945 return err; 1946 } 1947 1948 static unsigned int run_filter(struct sk_buff *skb, 1949 const struct sock *sk, 1950 unsigned int res) 1951 { 1952 struct sk_filter *filter; 1953 1954 rcu_read_lock(); 1955 filter = rcu_dereference(sk->sk_filter); 1956 if (filter != NULL) 1957 res = bpf_prog_run_clear_cb(filter->prog, skb); 1958 rcu_read_unlock(); 1959 1960 return res; 1961 } 1962 1963 /* 1964 * This function makes lazy skb cloning in hope that most of packets 1965 * are discarded by BPF. 1966 * 1967 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1968 * and skb->cb are mangled. It works because (and until) packets 1969 * falling here are owned by current CPU. Output packets are cloned 1970 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1971 * sequencially, so that if we return skb to original state on exit, 1972 * we will not harm anyone. 1973 */ 1974 1975 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1976 struct packet_type *pt, struct net_device *orig_dev) 1977 { 1978 struct sock *sk; 1979 struct sockaddr_ll *sll; 1980 struct packet_sock *po; 1981 u8 *skb_head = skb->data; 1982 int skb_len = skb->len; 1983 unsigned int snaplen, res; 1984 1985 if (skb->pkt_type == PACKET_LOOPBACK) 1986 goto drop; 1987 1988 sk = pt->af_packet_priv; 1989 po = pkt_sk(sk); 1990 1991 if (!net_eq(dev_net(dev), sock_net(sk))) 1992 goto drop; 1993 1994 skb->dev = dev; 1995 1996 if (dev->header_ops) { 1997 /* The device has an explicit notion of ll header, 1998 * exported to higher levels. 1999 * 2000 * Otherwise, the device hides details of its frame 2001 * structure, so that corresponding packet head is 2002 * never delivered to user. 2003 */ 2004 if (sk->sk_type != SOCK_DGRAM) 2005 skb_push(skb, skb->data - skb_mac_header(skb)); 2006 else if (skb->pkt_type == PACKET_OUTGOING) { 2007 /* Special case: outgoing packets have ll header at head */ 2008 skb_pull(skb, skb_network_offset(skb)); 2009 } 2010 } 2011 2012 snaplen = skb->len; 2013 2014 res = run_filter(skb, sk, snaplen); 2015 if (!res) 2016 goto drop_n_restore; 2017 if (snaplen > res) 2018 snaplen = res; 2019 2020 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2021 goto drop_n_acct; 2022 2023 if (skb_shared(skb)) { 2024 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2025 if (nskb == NULL) 2026 goto drop_n_acct; 2027 2028 if (skb_head != skb->data) { 2029 skb->data = skb_head; 2030 skb->len = skb_len; 2031 } 2032 consume_skb(skb); 2033 skb = nskb; 2034 } 2035 2036 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2037 2038 sll = &PACKET_SKB_CB(skb)->sa.ll; 2039 sll->sll_hatype = dev->type; 2040 sll->sll_pkttype = skb->pkt_type; 2041 if (unlikely(po->origdev)) 2042 sll->sll_ifindex = orig_dev->ifindex; 2043 else 2044 sll->sll_ifindex = dev->ifindex; 2045 2046 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2047 2048 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2049 * Use their space for storing the original skb length. 2050 */ 2051 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2052 2053 if (pskb_trim(skb, snaplen)) 2054 goto drop_n_acct; 2055 2056 skb_set_owner_r(skb, sk); 2057 skb->dev = NULL; 2058 skb_dst_drop(skb); 2059 2060 /* drop conntrack reference */ 2061 nf_reset(skb); 2062 2063 spin_lock(&sk->sk_receive_queue.lock); 2064 po->stats.stats1.tp_packets++; 2065 sock_skb_set_dropcount(sk, skb); 2066 __skb_queue_tail(&sk->sk_receive_queue, skb); 2067 spin_unlock(&sk->sk_receive_queue.lock); 2068 sk->sk_data_ready(sk); 2069 return 0; 2070 2071 drop_n_acct: 2072 spin_lock(&sk->sk_receive_queue.lock); 2073 po->stats.stats1.tp_drops++; 2074 atomic_inc(&sk->sk_drops); 2075 spin_unlock(&sk->sk_receive_queue.lock); 2076 2077 drop_n_restore: 2078 if (skb_head != skb->data && skb_shared(skb)) { 2079 skb->data = skb_head; 2080 skb->len = skb_len; 2081 } 2082 drop: 2083 consume_skb(skb); 2084 return 0; 2085 } 2086 2087 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2088 struct packet_type *pt, struct net_device *orig_dev) 2089 { 2090 struct sock *sk; 2091 struct packet_sock *po; 2092 struct sockaddr_ll *sll; 2093 union tpacket_uhdr h; 2094 u8 *skb_head = skb->data; 2095 int skb_len = skb->len; 2096 unsigned int snaplen, res; 2097 unsigned long status = TP_STATUS_USER; 2098 unsigned short macoff, netoff, hdrlen; 2099 struct sk_buff *copy_skb = NULL; 2100 struct timespec ts; 2101 __u32 ts_status; 2102 2103 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2104 * We may add members to them until current aligned size without forcing 2105 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2106 */ 2107 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2108 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2109 2110 if (skb->pkt_type == PACKET_LOOPBACK) 2111 goto drop; 2112 2113 sk = pt->af_packet_priv; 2114 po = pkt_sk(sk); 2115 2116 if (!net_eq(dev_net(dev), sock_net(sk))) 2117 goto drop; 2118 2119 if (dev->header_ops) { 2120 if (sk->sk_type != SOCK_DGRAM) 2121 skb_push(skb, skb->data - skb_mac_header(skb)); 2122 else if (skb->pkt_type == PACKET_OUTGOING) { 2123 /* Special case: outgoing packets have ll header at head */ 2124 skb_pull(skb, skb_network_offset(skb)); 2125 } 2126 } 2127 2128 snaplen = skb->len; 2129 2130 res = run_filter(skb, sk, snaplen); 2131 if (!res) 2132 goto drop_n_restore; 2133 2134 if (skb->ip_summed == CHECKSUM_PARTIAL) 2135 status |= TP_STATUS_CSUMNOTREADY; 2136 else if (skb->pkt_type != PACKET_OUTGOING && 2137 (skb->ip_summed == CHECKSUM_COMPLETE || 2138 skb_csum_unnecessary(skb))) 2139 status |= TP_STATUS_CSUM_VALID; 2140 2141 if (snaplen > res) 2142 snaplen = res; 2143 2144 if (sk->sk_type == SOCK_DGRAM) { 2145 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2146 po->tp_reserve; 2147 } else { 2148 unsigned int maclen = skb_network_offset(skb); 2149 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2150 (maclen < 16 ? 16 : maclen)) + 2151 po->tp_reserve; 2152 macoff = netoff - maclen; 2153 } 2154 if (po->tp_version <= TPACKET_V2) { 2155 if (macoff + snaplen > po->rx_ring.frame_size) { 2156 if (po->copy_thresh && 2157 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2158 if (skb_shared(skb)) { 2159 copy_skb = skb_clone(skb, GFP_ATOMIC); 2160 } else { 2161 copy_skb = skb_get(skb); 2162 skb_head = skb->data; 2163 } 2164 if (copy_skb) 2165 skb_set_owner_r(copy_skb, sk); 2166 } 2167 snaplen = po->rx_ring.frame_size - macoff; 2168 if ((int)snaplen < 0) 2169 snaplen = 0; 2170 } 2171 } else if (unlikely(macoff + snaplen > 2172 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2173 u32 nval; 2174 2175 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2176 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2177 snaplen, nval, macoff); 2178 snaplen = nval; 2179 if (unlikely((int)snaplen < 0)) { 2180 snaplen = 0; 2181 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2182 } 2183 } 2184 spin_lock(&sk->sk_receive_queue.lock); 2185 h.raw = packet_current_rx_frame(po, skb, 2186 TP_STATUS_KERNEL, (macoff+snaplen)); 2187 if (!h.raw) 2188 goto ring_is_full; 2189 if (po->tp_version <= TPACKET_V2) { 2190 packet_increment_rx_head(po, &po->rx_ring); 2191 /* 2192 * LOSING will be reported till you read the stats, 2193 * because it's COR - Clear On Read. 2194 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2195 * at packet level. 2196 */ 2197 if (po->stats.stats1.tp_drops) 2198 status |= TP_STATUS_LOSING; 2199 } 2200 po->stats.stats1.tp_packets++; 2201 if (copy_skb) { 2202 status |= TP_STATUS_COPY; 2203 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2204 } 2205 spin_unlock(&sk->sk_receive_queue.lock); 2206 2207 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2208 2209 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 2210 getnstimeofday(&ts); 2211 2212 status |= ts_status; 2213 2214 switch (po->tp_version) { 2215 case TPACKET_V1: 2216 h.h1->tp_len = skb->len; 2217 h.h1->tp_snaplen = snaplen; 2218 h.h1->tp_mac = macoff; 2219 h.h1->tp_net = netoff; 2220 h.h1->tp_sec = ts.tv_sec; 2221 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2222 hdrlen = sizeof(*h.h1); 2223 break; 2224 case TPACKET_V2: 2225 h.h2->tp_len = skb->len; 2226 h.h2->tp_snaplen = snaplen; 2227 h.h2->tp_mac = macoff; 2228 h.h2->tp_net = netoff; 2229 h.h2->tp_sec = ts.tv_sec; 2230 h.h2->tp_nsec = ts.tv_nsec; 2231 if (skb_vlan_tag_present(skb)) { 2232 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2233 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2234 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2235 } else { 2236 h.h2->tp_vlan_tci = 0; 2237 h.h2->tp_vlan_tpid = 0; 2238 } 2239 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2240 hdrlen = sizeof(*h.h2); 2241 break; 2242 case TPACKET_V3: 2243 /* tp_nxt_offset,vlan are already populated above. 2244 * So DONT clear those fields here 2245 */ 2246 h.h3->tp_status |= status; 2247 h.h3->tp_len = skb->len; 2248 h.h3->tp_snaplen = snaplen; 2249 h.h3->tp_mac = macoff; 2250 h.h3->tp_net = netoff; 2251 h.h3->tp_sec = ts.tv_sec; 2252 h.h3->tp_nsec = ts.tv_nsec; 2253 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2254 hdrlen = sizeof(*h.h3); 2255 break; 2256 default: 2257 BUG(); 2258 } 2259 2260 sll = h.raw + TPACKET_ALIGN(hdrlen); 2261 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2262 sll->sll_family = AF_PACKET; 2263 sll->sll_hatype = dev->type; 2264 sll->sll_protocol = skb->protocol; 2265 sll->sll_pkttype = skb->pkt_type; 2266 if (unlikely(po->origdev)) 2267 sll->sll_ifindex = orig_dev->ifindex; 2268 else 2269 sll->sll_ifindex = dev->ifindex; 2270 2271 smp_mb(); 2272 2273 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2274 if (po->tp_version <= TPACKET_V2) { 2275 u8 *start, *end; 2276 2277 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2278 macoff + snaplen); 2279 2280 for (start = h.raw; start < end; start += PAGE_SIZE) 2281 flush_dcache_page(pgv_to_page(start)); 2282 } 2283 smp_wmb(); 2284 #endif 2285 2286 if (po->tp_version <= TPACKET_V2) { 2287 __packet_set_status(po, h.raw, status); 2288 sk->sk_data_ready(sk); 2289 } else { 2290 prb_clear_blk_fill_status(&po->rx_ring); 2291 } 2292 2293 drop_n_restore: 2294 if (skb_head != skb->data && skb_shared(skb)) { 2295 skb->data = skb_head; 2296 skb->len = skb_len; 2297 } 2298 drop: 2299 kfree_skb(skb); 2300 return 0; 2301 2302 ring_is_full: 2303 po->stats.stats1.tp_drops++; 2304 spin_unlock(&sk->sk_receive_queue.lock); 2305 2306 sk->sk_data_ready(sk); 2307 kfree_skb(copy_skb); 2308 goto drop_n_restore; 2309 } 2310 2311 static void tpacket_destruct_skb(struct sk_buff *skb) 2312 { 2313 struct packet_sock *po = pkt_sk(skb->sk); 2314 2315 if (likely(po->tx_ring.pg_vec)) { 2316 void *ph; 2317 __u32 ts; 2318 2319 ph = skb_shinfo(skb)->destructor_arg; 2320 packet_dec_pending(&po->tx_ring); 2321 2322 ts = __packet_set_timestamp(po, ph, skb); 2323 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2324 } 2325 2326 sock_wfree(skb); 2327 } 2328 2329 static bool ll_header_truncated(const struct net_device *dev, int len) 2330 { 2331 /* net device doesn't like empty head */ 2332 if (unlikely(len < dev->hard_header_len)) { 2333 net_warn_ratelimited("%s: packet size is too short (%d < %d)\n", 2334 current->comm, len, dev->hard_header_len); 2335 return true; 2336 } 2337 2338 return false; 2339 } 2340 2341 static void tpacket_set_protocol(const struct net_device *dev, 2342 struct sk_buff *skb) 2343 { 2344 if (dev->type == ARPHRD_ETHER) { 2345 skb_reset_mac_header(skb); 2346 skb->protocol = eth_hdr(skb)->h_proto; 2347 } 2348 } 2349 2350 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2351 void *frame, struct net_device *dev, int size_max, 2352 __be16 proto, unsigned char *addr, int hlen) 2353 { 2354 union tpacket_uhdr ph; 2355 int to_write, offset, len, tp_len, nr_frags, len_max; 2356 struct socket *sock = po->sk.sk_socket; 2357 struct page *page; 2358 void *data; 2359 int err; 2360 2361 ph.raw = frame; 2362 2363 skb->protocol = proto; 2364 skb->dev = dev; 2365 skb->priority = po->sk.sk_priority; 2366 skb->mark = po->sk.sk_mark; 2367 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 2368 skb_shinfo(skb)->destructor_arg = ph.raw; 2369 2370 switch (po->tp_version) { 2371 case TPACKET_V2: 2372 tp_len = ph.h2->tp_len; 2373 break; 2374 default: 2375 tp_len = ph.h1->tp_len; 2376 break; 2377 } 2378 if (unlikely(tp_len > size_max)) { 2379 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2380 return -EMSGSIZE; 2381 } 2382 2383 skb_reserve(skb, hlen); 2384 skb_reset_network_header(skb); 2385 2386 if (unlikely(po->tp_tx_has_off)) { 2387 int off_min, off_max, off; 2388 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2389 off_max = po->tx_ring.frame_size - tp_len; 2390 if (sock->type == SOCK_DGRAM) { 2391 switch (po->tp_version) { 2392 case TPACKET_V2: 2393 off = ph.h2->tp_net; 2394 break; 2395 default: 2396 off = ph.h1->tp_net; 2397 break; 2398 } 2399 } else { 2400 switch (po->tp_version) { 2401 case TPACKET_V2: 2402 off = ph.h2->tp_mac; 2403 break; 2404 default: 2405 off = ph.h1->tp_mac; 2406 break; 2407 } 2408 } 2409 if (unlikely((off < off_min) || (off_max < off))) 2410 return -EINVAL; 2411 data = ph.raw + off; 2412 } else { 2413 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 2414 } 2415 to_write = tp_len; 2416 2417 if (sock->type == SOCK_DGRAM) { 2418 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2419 NULL, tp_len); 2420 if (unlikely(err < 0)) 2421 return -EINVAL; 2422 } else if (dev->hard_header_len) { 2423 if (ll_header_truncated(dev, tp_len)) 2424 return -EINVAL; 2425 2426 skb_push(skb, dev->hard_header_len); 2427 err = skb_store_bits(skb, 0, data, 2428 dev->hard_header_len); 2429 if (unlikely(err)) 2430 return err; 2431 if (!skb->protocol) 2432 tpacket_set_protocol(dev, skb); 2433 2434 data += dev->hard_header_len; 2435 to_write -= dev->hard_header_len; 2436 } 2437 2438 offset = offset_in_page(data); 2439 len_max = PAGE_SIZE - offset; 2440 len = ((to_write > len_max) ? len_max : to_write); 2441 2442 skb->data_len = to_write; 2443 skb->len += to_write; 2444 skb->truesize += to_write; 2445 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2446 2447 while (likely(to_write)) { 2448 nr_frags = skb_shinfo(skb)->nr_frags; 2449 2450 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2451 pr_err("Packet exceed the number of skb frags(%lu)\n", 2452 MAX_SKB_FRAGS); 2453 return -EFAULT; 2454 } 2455 2456 page = pgv_to_page(data); 2457 data += len; 2458 flush_dcache_page(page); 2459 get_page(page); 2460 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2461 to_write -= len; 2462 offset = 0; 2463 len_max = PAGE_SIZE; 2464 len = ((to_write > len_max) ? len_max : to_write); 2465 } 2466 2467 skb_probe_transport_header(skb, 0); 2468 2469 return tp_len; 2470 } 2471 2472 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2473 { 2474 struct sk_buff *skb; 2475 struct net_device *dev; 2476 __be16 proto; 2477 int err, reserve = 0; 2478 void *ph; 2479 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2480 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2481 int tp_len, size_max; 2482 unsigned char *addr; 2483 int len_sum = 0; 2484 int status = TP_STATUS_AVAILABLE; 2485 int hlen, tlen; 2486 2487 mutex_lock(&po->pg_vec_lock); 2488 2489 if (likely(saddr == NULL)) { 2490 dev = packet_cached_dev_get(po); 2491 proto = po->num; 2492 addr = NULL; 2493 } else { 2494 err = -EINVAL; 2495 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2496 goto out; 2497 if (msg->msg_namelen < (saddr->sll_halen 2498 + offsetof(struct sockaddr_ll, 2499 sll_addr))) 2500 goto out; 2501 proto = saddr->sll_protocol; 2502 addr = saddr->sll_addr; 2503 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2504 } 2505 2506 err = -ENXIO; 2507 if (unlikely(dev == NULL)) 2508 goto out; 2509 err = -ENETDOWN; 2510 if (unlikely(!(dev->flags & IFF_UP))) 2511 goto out_put; 2512 2513 if (po->sk.sk_socket->type == SOCK_RAW) 2514 reserve = dev->hard_header_len; 2515 size_max = po->tx_ring.frame_size 2516 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2517 2518 if (size_max > dev->mtu + reserve + VLAN_HLEN) 2519 size_max = dev->mtu + reserve + VLAN_HLEN; 2520 2521 do { 2522 ph = packet_current_frame(po, &po->tx_ring, 2523 TP_STATUS_SEND_REQUEST); 2524 if (unlikely(ph == NULL)) { 2525 if (need_wait && need_resched()) 2526 schedule(); 2527 continue; 2528 } 2529 2530 status = TP_STATUS_SEND_REQUEST; 2531 hlen = LL_RESERVED_SPACE(dev); 2532 tlen = dev->needed_tailroom; 2533 skb = sock_alloc_send_skb(&po->sk, 2534 hlen + tlen + sizeof(struct sockaddr_ll), 2535 !need_wait, &err); 2536 2537 if (unlikely(skb == NULL)) { 2538 /* we assume the socket was initially writeable ... */ 2539 if (likely(len_sum > 0)) 2540 err = len_sum; 2541 goto out_status; 2542 } 2543 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2544 addr, hlen); 2545 if (likely(tp_len >= 0) && 2546 tp_len > dev->mtu + reserve && 2547 !packet_extra_vlan_len_allowed(dev, skb)) 2548 tp_len = -EMSGSIZE; 2549 2550 if (unlikely(tp_len < 0)) { 2551 if (po->tp_loss) { 2552 __packet_set_status(po, ph, 2553 TP_STATUS_AVAILABLE); 2554 packet_increment_head(&po->tx_ring); 2555 kfree_skb(skb); 2556 continue; 2557 } else { 2558 status = TP_STATUS_WRONG_FORMAT; 2559 err = tp_len; 2560 goto out_status; 2561 } 2562 } 2563 2564 packet_pick_tx_queue(dev, skb); 2565 2566 skb->destructor = tpacket_destruct_skb; 2567 __packet_set_status(po, ph, TP_STATUS_SENDING); 2568 packet_inc_pending(&po->tx_ring); 2569 2570 status = TP_STATUS_SEND_REQUEST; 2571 err = po->xmit(skb); 2572 if (unlikely(err > 0)) { 2573 err = net_xmit_errno(err); 2574 if (err && __packet_get_status(po, ph) == 2575 TP_STATUS_AVAILABLE) { 2576 /* skb was destructed already */ 2577 skb = NULL; 2578 goto out_status; 2579 } 2580 /* 2581 * skb was dropped but not destructed yet; 2582 * let's treat it like congestion or err < 0 2583 */ 2584 err = 0; 2585 } 2586 packet_increment_head(&po->tx_ring); 2587 len_sum += tp_len; 2588 } while (likely((ph != NULL) || 2589 /* Note: packet_read_pending() might be slow if we have 2590 * to call it as it's per_cpu variable, but in fast-path 2591 * we already short-circuit the loop with the first 2592 * condition, and luckily don't have to go that path 2593 * anyway. 2594 */ 2595 (need_wait && packet_read_pending(&po->tx_ring)))); 2596 2597 err = len_sum; 2598 goto out_put; 2599 2600 out_status: 2601 __packet_set_status(po, ph, status); 2602 kfree_skb(skb); 2603 out_put: 2604 dev_put(dev); 2605 out: 2606 mutex_unlock(&po->pg_vec_lock); 2607 return err; 2608 } 2609 2610 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2611 size_t reserve, size_t len, 2612 size_t linear, int noblock, 2613 int *err) 2614 { 2615 struct sk_buff *skb; 2616 2617 /* Under a page? Don't bother with paged skb. */ 2618 if (prepad + len < PAGE_SIZE || !linear) 2619 linear = len; 2620 2621 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2622 err, 0); 2623 if (!skb) 2624 return NULL; 2625 2626 skb_reserve(skb, reserve); 2627 skb_put(skb, linear); 2628 skb->data_len = len - linear; 2629 skb->len += len - linear; 2630 2631 return skb; 2632 } 2633 2634 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2635 { 2636 struct sock *sk = sock->sk; 2637 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2638 struct sk_buff *skb; 2639 struct net_device *dev; 2640 __be16 proto; 2641 unsigned char *addr; 2642 int err, reserve = 0; 2643 struct sockcm_cookie sockc; 2644 struct virtio_net_hdr vnet_hdr = { 0 }; 2645 int offset = 0; 2646 int vnet_hdr_len; 2647 struct packet_sock *po = pkt_sk(sk); 2648 unsigned short gso_type = 0; 2649 int hlen, tlen; 2650 int extra_len = 0; 2651 ssize_t n; 2652 2653 /* 2654 * Get and verify the address. 2655 */ 2656 2657 if (likely(saddr == NULL)) { 2658 dev = packet_cached_dev_get(po); 2659 proto = po->num; 2660 addr = NULL; 2661 } else { 2662 err = -EINVAL; 2663 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2664 goto out; 2665 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2666 goto out; 2667 proto = saddr->sll_protocol; 2668 addr = saddr->sll_addr; 2669 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2670 } 2671 2672 err = -ENXIO; 2673 if (unlikely(dev == NULL)) 2674 goto out_unlock; 2675 err = -ENETDOWN; 2676 if (unlikely(!(dev->flags & IFF_UP))) 2677 goto out_unlock; 2678 2679 sockc.mark = sk->sk_mark; 2680 if (msg->msg_controllen) { 2681 err = sock_cmsg_send(sk, msg, &sockc); 2682 if (unlikely(err)) 2683 goto out_unlock; 2684 } 2685 2686 if (sock->type == SOCK_RAW) 2687 reserve = dev->hard_header_len; 2688 if (po->has_vnet_hdr) { 2689 vnet_hdr_len = sizeof(vnet_hdr); 2690 2691 err = -EINVAL; 2692 if (len < vnet_hdr_len) 2693 goto out_unlock; 2694 2695 len -= vnet_hdr_len; 2696 2697 err = -EFAULT; 2698 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter); 2699 if (n != vnet_hdr_len) 2700 goto out_unlock; 2701 2702 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2703 (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + 2704 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 > 2705 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len))) 2706 vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(), 2707 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + 2708 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2); 2709 2710 err = -EINVAL; 2711 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len) 2712 goto out_unlock; 2713 2714 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2715 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2716 case VIRTIO_NET_HDR_GSO_TCPV4: 2717 gso_type = SKB_GSO_TCPV4; 2718 break; 2719 case VIRTIO_NET_HDR_GSO_TCPV6: 2720 gso_type = SKB_GSO_TCPV6; 2721 break; 2722 case VIRTIO_NET_HDR_GSO_UDP: 2723 gso_type = SKB_GSO_UDP; 2724 break; 2725 default: 2726 goto out_unlock; 2727 } 2728 2729 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2730 gso_type |= SKB_GSO_TCP_ECN; 2731 2732 if (vnet_hdr.gso_size == 0) 2733 goto out_unlock; 2734 2735 } 2736 } 2737 2738 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2739 if (!netif_supports_nofcs(dev)) { 2740 err = -EPROTONOSUPPORT; 2741 goto out_unlock; 2742 } 2743 extra_len = 4; /* We're doing our own CRC */ 2744 } 2745 2746 err = -EMSGSIZE; 2747 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2748 goto out_unlock; 2749 2750 err = -ENOBUFS; 2751 hlen = LL_RESERVED_SPACE(dev); 2752 tlen = dev->needed_tailroom; 2753 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, 2754 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len), 2755 msg->msg_flags & MSG_DONTWAIT, &err); 2756 if (skb == NULL) 2757 goto out_unlock; 2758 2759 skb_set_network_header(skb, reserve); 2760 2761 err = -EINVAL; 2762 if (sock->type == SOCK_DGRAM) { 2763 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2764 if (unlikely(offset < 0)) 2765 goto out_free; 2766 } else { 2767 if (ll_header_truncated(dev, len)) 2768 goto out_free; 2769 } 2770 2771 /* Returns -EFAULT on error */ 2772 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2773 if (err) 2774 goto out_free; 2775 2776 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2777 2778 if (!gso_type && (len > dev->mtu + reserve + extra_len) && 2779 !packet_extra_vlan_len_allowed(dev, skb)) { 2780 err = -EMSGSIZE; 2781 goto out_free; 2782 } 2783 2784 skb->protocol = proto; 2785 skb->dev = dev; 2786 skb->priority = sk->sk_priority; 2787 skb->mark = sockc.mark; 2788 2789 packet_pick_tx_queue(dev, skb); 2790 2791 if (po->has_vnet_hdr) { 2792 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2793 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start); 2794 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset); 2795 if (!skb_partial_csum_set(skb, s, o)) { 2796 err = -EINVAL; 2797 goto out_free; 2798 } 2799 } 2800 2801 skb_shinfo(skb)->gso_size = 2802 __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size); 2803 skb_shinfo(skb)->gso_type = gso_type; 2804 2805 /* Header must be checked, and gso_segs computed. */ 2806 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2807 skb_shinfo(skb)->gso_segs = 0; 2808 2809 len += vnet_hdr_len; 2810 } 2811 2812 skb_probe_transport_header(skb, reserve); 2813 2814 if (unlikely(extra_len == 4)) 2815 skb->no_fcs = 1; 2816 2817 err = po->xmit(skb); 2818 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2819 goto out_unlock; 2820 2821 dev_put(dev); 2822 2823 return len; 2824 2825 out_free: 2826 kfree_skb(skb); 2827 out_unlock: 2828 if (dev) 2829 dev_put(dev); 2830 out: 2831 return err; 2832 } 2833 2834 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 2835 { 2836 struct sock *sk = sock->sk; 2837 struct packet_sock *po = pkt_sk(sk); 2838 2839 if (po->tx_ring.pg_vec) 2840 return tpacket_snd(po, msg); 2841 else 2842 return packet_snd(sock, msg, len); 2843 } 2844 2845 /* 2846 * Close a PACKET socket. This is fairly simple. We immediately go 2847 * to 'closed' state and remove our protocol entry in the device list. 2848 */ 2849 2850 static int packet_release(struct socket *sock) 2851 { 2852 struct sock *sk = sock->sk; 2853 struct packet_sock *po; 2854 struct net *net; 2855 union tpacket_req_u req_u; 2856 2857 if (!sk) 2858 return 0; 2859 2860 net = sock_net(sk); 2861 po = pkt_sk(sk); 2862 2863 mutex_lock(&net->packet.sklist_lock); 2864 sk_del_node_init_rcu(sk); 2865 mutex_unlock(&net->packet.sklist_lock); 2866 2867 preempt_disable(); 2868 sock_prot_inuse_add(net, sk->sk_prot, -1); 2869 preempt_enable(); 2870 2871 spin_lock(&po->bind_lock); 2872 unregister_prot_hook(sk, false); 2873 packet_cached_dev_reset(po); 2874 2875 if (po->prot_hook.dev) { 2876 dev_put(po->prot_hook.dev); 2877 po->prot_hook.dev = NULL; 2878 } 2879 spin_unlock(&po->bind_lock); 2880 2881 packet_flush_mclist(sk); 2882 2883 if (po->rx_ring.pg_vec) { 2884 memset(&req_u, 0, sizeof(req_u)); 2885 packet_set_ring(sk, &req_u, 1, 0); 2886 } 2887 2888 if (po->tx_ring.pg_vec) { 2889 memset(&req_u, 0, sizeof(req_u)); 2890 packet_set_ring(sk, &req_u, 1, 1); 2891 } 2892 2893 fanout_release(sk); 2894 2895 synchronize_net(); 2896 /* 2897 * Now the socket is dead. No more input will appear. 2898 */ 2899 sock_orphan(sk); 2900 sock->sk = NULL; 2901 2902 /* Purge queues */ 2903 2904 skb_queue_purge(&sk->sk_receive_queue); 2905 packet_free_pending(po); 2906 sk_refcnt_debug_release(sk); 2907 2908 sock_put(sk); 2909 return 0; 2910 } 2911 2912 /* 2913 * Attach a packet hook. 2914 */ 2915 2916 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 2917 __be16 proto) 2918 { 2919 struct packet_sock *po = pkt_sk(sk); 2920 struct net_device *dev_curr; 2921 __be16 proto_curr; 2922 bool need_rehook; 2923 struct net_device *dev = NULL; 2924 int ret = 0; 2925 bool unlisted = false; 2926 2927 if (po->fanout) 2928 return -EINVAL; 2929 2930 lock_sock(sk); 2931 spin_lock(&po->bind_lock); 2932 rcu_read_lock(); 2933 2934 if (name) { 2935 dev = dev_get_by_name_rcu(sock_net(sk), name); 2936 if (!dev) { 2937 ret = -ENODEV; 2938 goto out_unlock; 2939 } 2940 } else if (ifindex) { 2941 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 2942 if (!dev) { 2943 ret = -ENODEV; 2944 goto out_unlock; 2945 } 2946 } 2947 2948 if (dev) 2949 dev_hold(dev); 2950 2951 proto_curr = po->prot_hook.type; 2952 dev_curr = po->prot_hook.dev; 2953 2954 need_rehook = proto_curr != proto || dev_curr != dev; 2955 2956 if (need_rehook) { 2957 if (po->running) { 2958 rcu_read_unlock(); 2959 __unregister_prot_hook(sk, true); 2960 rcu_read_lock(); 2961 dev_curr = po->prot_hook.dev; 2962 if (dev) 2963 unlisted = !dev_get_by_index_rcu(sock_net(sk), 2964 dev->ifindex); 2965 } 2966 2967 po->num = proto; 2968 po->prot_hook.type = proto; 2969 2970 if (unlikely(unlisted)) { 2971 dev_put(dev); 2972 po->prot_hook.dev = NULL; 2973 po->ifindex = -1; 2974 packet_cached_dev_reset(po); 2975 } else { 2976 po->prot_hook.dev = dev; 2977 po->ifindex = dev ? dev->ifindex : 0; 2978 packet_cached_dev_assign(po, dev); 2979 } 2980 } 2981 if (dev_curr) 2982 dev_put(dev_curr); 2983 2984 if (proto == 0 || !need_rehook) 2985 goto out_unlock; 2986 2987 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 2988 register_prot_hook(sk); 2989 } else { 2990 sk->sk_err = ENETDOWN; 2991 if (!sock_flag(sk, SOCK_DEAD)) 2992 sk->sk_error_report(sk); 2993 } 2994 2995 out_unlock: 2996 rcu_read_unlock(); 2997 spin_unlock(&po->bind_lock); 2998 release_sock(sk); 2999 return ret; 3000 } 3001 3002 /* 3003 * Bind a packet socket to a device 3004 */ 3005 3006 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3007 int addr_len) 3008 { 3009 struct sock *sk = sock->sk; 3010 char name[15]; 3011 3012 /* 3013 * Check legality 3014 */ 3015 3016 if (addr_len != sizeof(struct sockaddr)) 3017 return -EINVAL; 3018 strlcpy(name, uaddr->sa_data, sizeof(name)); 3019 3020 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); 3021 } 3022 3023 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3024 { 3025 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3026 struct sock *sk = sock->sk; 3027 3028 /* 3029 * Check legality 3030 */ 3031 3032 if (addr_len < sizeof(struct sockaddr_ll)) 3033 return -EINVAL; 3034 if (sll->sll_family != AF_PACKET) 3035 return -EINVAL; 3036 3037 return packet_do_bind(sk, NULL, sll->sll_ifindex, 3038 sll->sll_protocol ? : pkt_sk(sk)->num); 3039 } 3040 3041 static struct proto packet_proto = { 3042 .name = "PACKET", 3043 .owner = THIS_MODULE, 3044 .obj_size = sizeof(struct packet_sock), 3045 }; 3046 3047 /* 3048 * Create a packet of type SOCK_PACKET. 3049 */ 3050 3051 static int packet_create(struct net *net, struct socket *sock, int protocol, 3052 int kern) 3053 { 3054 struct sock *sk; 3055 struct packet_sock *po; 3056 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3057 int err; 3058 3059 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3060 return -EPERM; 3061 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3062 sock->type != SOCK_PACKET) 3063 return -ESOCKTNOSUPPORT; 3064 3065 sock->state = SS_UNCONNECTED; 3066 3067 err = -ENOBUFS; 3068 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3069 if (sk == NULL) 3070 goto out; 3071 3072 sock->ops = &packet_ops; 3073 if (sock->type == SOCK_PACKET) 3074 sock->ops = &packet_ops_spkt; 3075 3076 sock_init_data(sock, sk); 3077 3078 po = pkt_sk(sk); 3079 sk->sk_family = PF_PACKET; 3080 po->num = proto; 3081 po->xmit = dev_queue_xmit; 3082 3083 err = packet_alloc_pending(po); 3084 if (err) 3085 goto out2; 3086 3087 packet_cached_dev_reset(po); 3088 3089 sk->sk_destruct = packet_sock_destruct; 3090 sk_refcnt_debug_inc(sk); 3091 3092 /* 3093 * Attach a protocol block 3094 */ 3095 3096 spin_lock_init(&po->bind_lock); 3097 mutex_init(&po->pg_vec_lock); 3098 po->rollover = NULL; 3099 po->prot_hook.func = packet_rcv; 3100 3101 if (sock->type == SOCK_PACKET) 3102 po->prot_hook.func = packet_rcv_spkt; 3103 3104 po->prot_hook.af_packet_priv = sk; 3105 3106 if (proto) { 3107 po->prot_hook.type = proto; 3108 register_prot_hook(sk); 3109 } 3110 3111 mutex_lock(&net->packet.sklist_lock); 3112 sk_add_node_rcu(sk, &net->packet.sklist); 3113 mutex_unlock(&net->packet.sklist_lock); 3114 3115 preempt_disable(); 3116 sock_prot_inuse_add(net, &packet_proto, 1); 3117 preempt_enable(); 3118 3119 return 0; 3120 out2: 3121 sk_free(sk); 3122 out: 3123 return err; 3124 } 3125 3126 /* 3127 * Pull a packet from our receive queue and hand it to the user. 3128 * If necessary we block. 3129 */ 3130 3131 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3132 int flags) 3133 { 3134 struct sock *sk = sock->sk; 3135 struct sk_buff *skb; 3136 int copied, err; 3137 int vnet_hdr_len = 0; 3138 unsigned int origlen = 0; 3139 3140 err = -EINVAL; 3141 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3142 goto out; 3143 3144 #if 0 3145 /* What error should we return now? EUNATTACH? */ 3146 if (pkt_sk(sk)->ifindex < 0) 3147 return -ENODEV; 3148 #endif 3149 3150 if (flags & MSG_ERRQUEUE) { 3151 err = sock_recv_errqueue(sk, msg, len, 3152 SOL_PACKET, PACKET_TX_TIMESTAMP); 3153 goto out; 3154 } 3155 3156 /* 3157 * Call the generic datagram receiver. This handles all sorts 3158 * of horrible races and re-entrancy so we can forget about it 3159 * in the protocol layers. 3160 * 3161 * Now it will return ENETDOWN, if device have just gone down, 3162 * but then it will block. 3163 */ 3164 3165 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3166 3167 /* 3168 * An error occurred so return it. Because skb_recv_datagram() 3169 * handles the blocking we don't see and worry about blocking 3170 * retries. 3171 */ 3172 3173 if (skb == NULL) 3174 goto out; 3175 3176 if (pkt_sk(sk)->pressure) 3177 packet_rcv_has_room(pkt_sk(sk), NULL); 3178 3179 if (pkt_sk(sk)->has_vnet_hdr) { 3180 struct virtio_net_hdr vnet_hdr = { 0 }; 3181 3182 err = -EINVAL; 3183 vnet_hdr_len = sizeof(vnet_hdr); 3184 if (len < vnet_hdr_len) 3185 goto out_free; 3186 3187 len -= vnet_hdr_len; 3188 3189 if (skb_is_gso(skb)) { 3190 struct skb_shared_info *sinfo = skb_shinfo(skb); 3191 3192 /* This is a hint as to how much should be linear. */ 3193 vnet_hdr.hdr_len = 3194 __cpu_to_virtio16(vio_le(), skb_headlen(skb)); 3195 vnet_hdr.gso_size = 3196 __cpu_to_virtio16(vio_le(), sinfo->gso_size); 3197 if (sinfo->gso_type & SKB_GSO_TCPV4) 3198 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 3199 else if (sinfo->gso_type & SKB_GSO_TCPV6) 3200 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 3201 else if (sinfo->gso_type & SKB_GSO_UDP) 3202 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 3203 else if (sinfo->gso_type & SKB_GSO_FCOE) 3204 goto out_free; 3205 else 3206 BUG(); 3207 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 3208 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 3209 } else 3210 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 3211 3212 if (skb->ip_summed == CHECKSUM_PARTIAL) { 3213 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 3214 vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(), 3215 skb_checksum_start_offset(skb)); 3216 vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(), 3217 skb->csum_offset); 3218 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3219 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 3220 } /* else everything is zero */ 3221 3222 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len); 3223 if (err < 0) 3224 goto out_free; 3225 } 3226 3227 /* You lose any data beyond the buffer you gave. If it worries 3228 * a user program they can ask the device for its MTU 3229 * anyway. 3230 */ 3231 copied = skb->len; 3232 if (copied > len) { 3233 copied = len; 3234 msg->msg_flags |= MSG_TRUNC; 3235 } 3236 3237 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3238 if (err) 3239 goto out_free; 3240 3241 if (sock->type != SOCK_PACKET) { 3242 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3243 3244 /* Original length was stored in sockaddr_ll fields */ 3245 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3246 sll->sll_family = AF_PACKET; 3247 sll->sll_protocol = skb->protocol; 3248 } 3249 3250 sock_recv_ts_and_drops(msg, sk, skb); 3251 3252 if (msg->msg_name) { 3253 /* If the address length field is there to be filled 3254 * in, we fill it in now. 3255 */ 3256 if (sock->type == SOCK_PACKET) { 3257 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3258 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3259 } else { 3260 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3261 3262 msg->msg_namelen = sll->sll_halen + 3263 offsetof(struct sockaddr_ll, sll_addr); 3264 } 3265 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 3266 msg->msg_namelen); 3267 } 3268 3269 if (pkt_sk(sk)->auxdata) { 3270 struct tpacket_auxdata aux; 3271 3272 aux.tp_status = TP_STATUS_USER; 3273 if (skb->ip_summed == CHECKSUM_PARTIAL) 3274 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3275 else if (skb->pkt_type != PACKET_OUTGOING && 3276 (skb->ip_summed == CHECKSUM_COMPLETE || 3277 skb_csum_unnecessary(skb))) 3278 aux.tp_status |= TP_STATUS_CSUM_VALID; 3279 3280 aux.tp_len = origlen; 3281 aux.tp_snaplen = skb->len; 3282 aux.tp_mac = 0; 3283 aux.tp_net = skb_network_offset(skb); 3284 if (skb_vlan_tag_present(skb)) { 3285 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3286 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3287 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3288 } else { 3289 aux.tp_vlan_tci = 0; 3290 aux.tp_vlan_tpid = 0; 3291 } 3292 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3293 } 3294 3295 /* 3296 * Free or return the buffer as appropriate. Again this 3297 * hides all the races and re-entrancy issues from us. 3298 */ 3299 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3300 3301 out_free: 3302 skb_free_datagram(sk, skb); 3303 out: 3304 return err; 3305 } 3306 3307 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3308 int *uaddr_len, int peer) 3309 { 3310 struct net_device *dev; 3311 struct sock *sk = sock->sk; 3312 3313 if (peer) 3314 return -EOPNOTSUPP; 3315 3316 uaddr->sa_family = AF_PACKET; 3317 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3318 rcu_read_lock(); 3319 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3320 if (dev) 3321 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3322 rcu_read_unlock(); 3323 *uaddr_len = sizeof(*uaddr); 3324 3325 return 0; 3326 } 3327 3328 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3329 int *uaddr_len, int peer) 3330 { 3331 struct net_device *dev; 3332 struct sock *sk = sock->sk; 3333 struct packet_sock *po = pkt_sk(sk); 3334 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3335 3336 if (peer) 3337 return -EOPNOTSUPP; 3338 3339 sll->sll_family = AF_PACKET; 3340 sll->sll_ifindex = po->ifindex; 3341 sll->sll_protocol = po->num; 3342 sll->sll_pkttype = 0; 3343 rcu_read_lock(); 3344 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3345 if (dev) { 3346 sll->sll_hatype = dev->type; 3347 sll->sll_halen = dev->addr_len; 3348 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3349 } else { 3350 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3351 sll->sll_halen = 0; 3352 } 3353 rcu_read_unlock(); 3354 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3355 3356 return 0; 3357 } 3358 3359 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3360 int what) 3361 { 3362 switch (i->type) { 3363 case PACKET_MR_MULTICAST: 3364 if (i->alen != dev->addr_len) 3365 return -EINVAL; 3366 if (what > 0) 3367 return dev_mc_add(dev, i->addr); 3368 else 3369 return dev_mc_del(dev, i->addr); 3370 break; 3371 case PACKET_MR_PROMISC: 3372 return dev_set_promiscuity(dev, what); 3373 case PACKET_MR_ALLMULTI: 3374 return dev_set_allmulti(dev, what); 3375 case PACKET_MR_UNICAST: 3376 if (i->alen != dev->addr_len) 3377 return -EINVAL; 3378 if (what > 0) 3379 return dev_uc_add(dev, i->addr); 3380 else 3381 return dev_uc_del(dev, i->addr); 3382 break; 3383 default: 3384 break; 3385 } 3386 return 0; 3387 } 3388 3389 static void packet_dev_mclist_delete(struct net_device *dev, 3390 struct packet_mclist **mlp) 3391 { 3392 struct packet_mclist *ml; 3393 3394 while ((ml = *mlp) != NULL) { 3395 if (ml->ifindex == dev->ifindex) { 3396 packet_dev_mc(dev, ml, -1); 3397 *mlp = ml->next; 3398 kfree(ml); 3399 } else 3400 mlp = &ml->next; 3401 } 3402 } 3403 3404 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3405 { 3406 struct packet_sock *po = pkt_sk(sk); 3407 struct packet_mclist *ml, *i; 3408 struct net_device *dev; 3409 int err; 3410 3411 rtnl_lock(); 3412 3413 err = -ENODEV; 3414 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3415 if (!dev) 3416 goto done; 3417 3418 err = -EINVAL; 3419 if (mreq->mr_alen > dev->addr_len) 3420 goto done; 3421 3422 err = -ENOBUFS; 3423 i = kmalloc(sizeof(*i), GFP_KERNEL); 3424 if (i == NULL) 3425 goto done; 3426 3427 err = 0; 3428 for (ml = po->mclist; ml; ml = ml->next) { 3429 if (ml->ifindex == mreq->mr_ifindex && 3430 ml->type == mreq->mr_type && 3431 ml->alen == mreq->mr_alen && 3432 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3433 ml->count++; 3434 /* Free the new element ... */ 3435 kfree(i); 3436 goto done; 3437 } 3438 } 3439 3440 i->type = mreq->mr_type; 3441 i->ifindex = mreq->mr_ifindex; 3442 i->alen = mreq->mr_alen; 3443 memcpy(i->addr, mreq->mr_address, i->alen); 3444 i->count = 1; 3445 i->next = po->mclist; 3446 po->mclist = i; 3447 err = packet_dev_mc(dev, i, 1); 3448 if (err) { 3449 po->mclist = i->next; 3450 kfree(i); 3451 } 3452 3453 done: 3454 rtnl_unlock(); 3455 return err; 3456 } 3457 3458 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3459 { 3460 struct packet_mclist *ml, **mlp; 3461 3462 rtnl_lock(); 3463 3464 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3465 if (ml->ifindex == mreq->mr_ifindex && 3466 ml->type == mreq->mr_type && 3467 ml->alen == mreq->mr_alen && 3468 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3469 if (--ml->count == 0) { 3470 struct net_device *dev; 3471 *mlp = ml->next; 3472 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3473 if (dev) 3474 packet_dev_mc(dev, ml, -1); 3475 kfree(ml); 3476 } 3477 break; 3478 } 3479 } 3480 rtnl_unlock(); 3481 return 0; 3482 } 3483 3484 static void packet_flush_mclist(struct sock *sk) 3485 { 3486 struct packet_sock *po = pkt_sk(sk); 3487 struct packet_mclist *ml; 3488 3489 if (!po->mclist) 3490 return; 3491 3492 rtnl_lock(); 3493 while ((ml = po->mclist) != NULL) { 3494 struct net_device *dev; 3495 3496 po->mclist = ml->next; 3497 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3498 if (dev != NULL) 3499 packet_dev_mc(dev, ml, -1); 3500 kfree(ml); 3501 } 3502 rtnl_unlock(); 3503 } 3504 3505 static int 3506 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3507 { 3508 struct sock *sk = sock->sk; 3509 struct packet_sock *po = pkt_sk(sk); 3510 int ret; 3511 3512 if (level != SOL_PACKET) 3513 return -ENOPROTOOPT; 3514 3515 switch (optname) { 3516 case PACKET_ADD_MEMBERSHIP: 3517 case PACKET_DROP_MEMBERSHIP: 3518 { 3519 struct packet_mreq_max mreq; 3520 int len = optlen; 3521 memset(&mreq, 0, sizeof(mreq)); 3522 if (len < sizeof(struct packet_mreq)) 3523 return -EINVAL; 3524 if (len > sizeof(mreq)) 3525 len = sizeof(mreq); 3526 if (copy_from_user(&mreq, optval, len)) 3527 return -EFAULT; 3528 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3529 return -EINVAL; 3530 if (optname == PACKET_ADD_MEMBERSHIP) 3531 ret = packet_mc_add(sk, &mreq); 3532 else 3533 ret = packet_mc_drop(sk, &mreq); 3534 return ret; 3535 } 3536 3537 case PACKET_RX_RING: 3538 case PACKET_TX_RING: 3539 { 3540 union tpacket_req_u req_u; 3541 int len; 3542 3543 switch (po->tp_version) { 3544 case TPACKET_V1: 3545 case TPACKET_V2: 3546 len = sizeof(req_u.req); 3547 break; 3548 case TPACKET_V3: 3549 default: 3550 len = sizeof(req_u.req3); 3551 break; 3552 } 3553 if (optlen < len) 3554 return -EINVAL; 3555 if (pkt_sk(sk)->has_vnet_hdr) 3556 return -EINVAL; 3557 if (copy_from_user(&req_u.req, optval, len)) 3558 return -EFAULT; 3559 return packet_set_ring(sk, &req_u, 0, 3560 optname == PACKET_TX_RING); 3561 } 3562 case PACKET_COPY_THRESH: 3563 { 3564 int val; 3565 3566 if (optlen != sizeof(val)) 3567 return -EINVAL; 3568 if (copy_from_user(&val, optval, sizeof(val))) 3569 return -EFAULT; 3570 3571 pkt_sk(sk)->copy_thresh = val; 3572 return 0; 3573 } 3574 case PACKET_VERSION: 3575 { 3576 int val; 3577 3578 if (optlen != sizeof(val)) 3579 return -EINVAL; 3580 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3581 return -EBUSY; 3582 if (copy_from_user(&val, optval, sizeof(val))) 3583 return -EFAULT; 3584 switch (val) { 3585 case TPACKET_V1: 3586 case TPACKET_V2: 3587 case TPACKET_V3: 3588 po->tp_version = val; 3589 return 0; 3590 default: 3591 return -EINVAL; 3592 } 3593 } 3594 case PACKET_RESERVE: 3595 { 3596 unsigned int val; 3597 3598 if (optlen != sizeof(val)) 3599 return -EINVAL; 3600 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3601 return -EBUSY; 3602 if (copy_from_user(&val, optval, sizeof(val))) 3603 return -EFAULT; 3604 po->tp_reserve = val; 3605 return 0; 3606 } 3607 case PACKET_LOSS: 3608 { 3609 unsigned int val; 3610 3611 if (optlen != sizeof(val)) 3612 return -EINVAL; 3613 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3614 return -EBUSY; 3615 if (copy_from_user(&val, optval, sizeof(val))) 3616 return -EFAULT; 3617 po->tp_loss = !!val; 3618 return 0; 3619 } 3620 case PACKET_AUXDATA: 3621 { 3622 int val; 3623 3624 if (optlen < sizeof(val)) 3625 return -EINVAL; 3626 if (copy_from_user(&val, optval, sizeof(val))) 3627 return -EFAULT; 3628 3629 po->auxdata = !!val; 3630 return 0; 3631 } 3632 case PACKET_ORIGDEV: 3633 { 3634 int val; 3635 3636 if (optlen < sizeof(val)) 3637 return -EINVAL; 3638 if (copy_from_user(&val, optval, sizeof(val))) 3639 return -EFAULT; 3640 3641 po->origdev = !!val; 3642 return 0; 3643 } 3644 case PACKET_VNET_HDR: 3645 { 3646 int val; 3647 3648 if (sock->type != SOCK_RAW) 3649 return -EINVAL; 3650 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3651 return -EBUSY; 3652 if (optlen < sizeof(val)) 3653 return -EINVAL; 3654 if (copy_from_user(&val, optval, sizeof(val))) 3655 return -EFAULT; 3656 3657 po->has_vnet_hdr = !!val; 3658 return 0; 3659 } 3660 case PACKET_TIMESTAMP: 3661 { 3662 int val; 3663 3664 if (optlen != sizeof(val)) 3665 return -EINVAL; 3666 if (copy_from_user(&val, optval, sizeof(val))) 3667 return -EFAULT; 3668 3669 po->tp_tstamp = val; 3670 return 0; 3671 } 3672 case PACKET_FANOUT: 3673 { 3674 int val; 3675 3676 if (optlen != sizeof(val)) 3677 return -EINVAL; 3678 if (copy_from_user(&val, optval, sizeof(val))) 3679 return -EFAULT; 3680 3681 return fanout_add(sk, val & 0xffff, val >> 16); 3682 } 3683 case PACKET_FANOUT_DATA: 3684 { 3685 if (!po->fanout) 3686 return -EINVAL; 3687 3688 return fanout_set_data(po, optval, optlen); 3689 } 3690 case PACKET_TX_HAS_OFF: 3691 { 3692 unsigned int val; 3693 3694 if (optlen != sizeof(val)) 3695 return -EINVAL; 3696 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3697 return -EBUSY; 3698 if (copy_from_user(&val, optval, sizeof(val))) 3699 return -EFAULT; 3700 po->tp_tx_has_off = !!val; 3701 return 0; 3702 } 3703 case PACKET_QDISC_BYPASS: 3704 { 3705 int val; 3706 3707 if (optlen != sizeof(val)) 3708 return -EINVAL; 3709 if (copy_from_user(&val, optval, sizeof(val))) 3710 return -EFAULT; 3711 3712 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3713 return 0; 3714 } 3715 default: 3716 return -ENOPROTOOPT; 3717 } 3718 } 3719 3720 static int packet_getsockopt(struct socket *sock, int level, int optname, 3721 char __user *optval, int __user *optlen) 3722 { 3723 int len; 3724 int val, lv = sizeof(val); 3725 struct sock *sk = sock->sk; 3726 struct packet_sock *po = pkt_sk(sk); 3727 void *data = &val; 3728 union tpacket_stats_u st; 3729 struct tpacket_rollover_stats rstats; 3730 3731 if (level != SOL_PACKET) 3732 return -ENOPROTOOPT; 3733 3734 if (get_user(len, optlen)) 3735 return -EFAULT; 3736 3737 if (len < 0) 3738 return -EINVAL; 3739 3740 switch (optname) { 3741 case PACKET_STATISTICS: 3742 spin_lock_bh(&sk->sk_receive_queue.lock); 3743 memcpy(&st, &po->stats, sizeof(st)); 3744 memset(&po->stats, 0, sizeof(po->stats)); 3745 spin_unlock_bh(&sk->sk_receive_queue.lock); 3746 3747 if (po->tp_version == TPACKET_V3) { 3748 lv = sizeof(struct tpacket_stats_v3); 3749 st.stats3.tp_packets += st.stats3.tp_drops; 3750 data = &st.stats3; 3751 } else { 3752 lv = sizeof(struct tpacket_stats); 3753 st.stats1.tp_packets += st.stats1.tp_drops; 3754 data = &st.stats1; 3755 } 3756 3757 break; 3758 case PACKET_AUXDATA: 3759 val = po->auxdata; 3760 break; 3761 case PACKET_ORIGDEV: 3762 val = po->origdev; 3763 break; 3764 case PACKET_VNET_HDR: 3765 val = po->has_vnet_hdr; 3766 break; 3767 case PACKET_VERSION: 3768 val = po->tp_version; 3769 break; 3770 case PACKET_HDRLEN: 3771 if (len > sizeof(int)) 3772 len = sizeof(int); 3773 if (copy_from_user(&val, optval, len)) 3774 return -EFAULT; 3775 switch (val) { 3776 case TPACKET_V1: 3777 val = sizeof(struct tpacket_hdr); 3778 break; 3779 case TPACKET_V2: 3780 val = sizeof(struct tpacket2_hdr); 3781 break; 3782 case TPACKET_V3: 3783 val = sizeof(struct tpacket3_hdr); 3784 break; 3785 default: 3786 return -EINVAL; 3787 } 3788 break; 3789 case PACKET_RESERVE: 3790 val = po->tp_reserve; 3791 break; 3792 case PACKET_LOSS: 3793 val = po->tp_loss; 3794 break; 3795 case PACKET_TIMESTAMP: 3796 val = po->tp_tstamp; 3797 break; 3798 case PACKET_FANOUT: 3799 val = (po->fanout ? 3800 ((u32)po->fanout->id | 3801 ((u32)po->fanout->type << 16) | 3802 ((u32)po->fanout->flags << 24)) : 3803 0); 3804 break; 3805 case PACKET_ROLLOVER_STATS: 3806 if (!po->rollover) 3807 return -EINVAL; 3808 rstats.tp_all = atomic_long_read(&po->rollover->num); 3809 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 3810 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 3811 data = &rstats; 3812 lv = sizeof(rstats); 3813 break; 3814 case PACKET_TX_HAS_OFF: 3815 val = po->tp_tx_has_off; 3816 break; 3817 case PACKET_QDISC_BYPASS: 3818 val = packet_use_direct_xmit(po); 3819 break; 3820 default: 3821 return -ENOPROTOOPT; 3822 } 3823 3824 if (len > lv) 3825 len = lv; 3826 if (put_user(len, optlen)) 3827 return -EFAULT; 3828 if (copy_to_user(optval, data, len)) 3829 return -EFAULT; 3830 return 0; 3831 } 3832 3833 3834 static int packet_notifier(struct notifier_block *this, 3835 unsigned long msg, void *ptr) 3836 { 3837 struct sock *sk; 3838 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3839 struct net *net = dev_net(dev); 3840 3841 rcu_read_lock(); 3842 sk_for_each_rcu(sk, &net->packet.sklist) { 3843 struct packet_sock *po = pkt_sk(sk); 3844 3845 switch (msg) { 3846 case NETDEV_UNREGISTER: 3847 if (po->mclist) 3848 packet_dev_mclist_delete(dev, &po->mclist); 3849 /* fallthrough */ 3850 3851 case NETDEV_DOWN: 3852 if (dev->ifindex == po->ifindex) { 3853 spin_lock(&po->bind_lock); 3854 if (po->running) { 3855 __unregister_prot_hook(sk, false); 3856 sk->sk_err = ENETDOWN; 3857 if (!sock_flag(sk, SOCK_DEAD)) 3858 sk->sk_error_report(sk); 3859 } 3860 if (msg == NETDEV_UNREGISTER) { 3861 packet_cached_dev_reset(po); 3862 po->ifindex = -1; 3863 if (po->prot_hook.dev) 3864 dev_put(po->prot_hook.dev); 3865 po->prot_hook.dev = NULL; 3866 } 3867 spin_unlock(&po->bind_lock); 3868 } 3869 break; 3870 case NETDEV_UP: 3871 if (dev->ifindex == po->ifindex) { 3872 spin_lock(&po->bind_lock); 3873 if (po->num) 3874 register_prot_hook(sk); 3875 spin_unlock(&po->bind_lock); 3876 } 3877 break; 3878 } 3879 } 3880 rcu_read_unlock(); 3881 return NOTIFY_DONE; 3882 } 3883 3884 3885 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3886 unsigned long arg) 3887 { 3888 struct sock *sk = sock->sk; 3889 3890 switch (cmd) { 3891 case SIOCOUTQ: 3892 { 3893 int amount = sk_wmem_alloc_get(sk); 3894 3895 return put_user(amount, (int __user *)arg); 3896 } 3897 case SIOCINQ: 3898 { 3899 struct sk_buff *skb; 3900 int amount = 0; 3901 3902 spin_lock_bh(&sk->sk_receive_queue.lock); 3903 skb = skb_peek(&sk->sk_receive_queue); 3904 if (skb) 3905 amount = skb->len; 3906 spin_unlock_bh(&sk->sk_receive_queue.lock); 3907 return put_user(amount, (int __user *)arg); 3908 } 3909 case SIOCGSTAMP: 3910 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3911 case SIOCGSTAMPNS: 3912 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3913 3914 #ifdef CONFIG_INET 3915 case SIOCADDRT: 3916 case SIOCDELRT: 3917 case SIOCDARP: 3918 case SIOCGARP: 3919 case SIOCSARP: 3920 case SIOCGIFADDR: 3921 case SIOCSIFADDR: 3922 case SIOCGIFBRDADDR: 3923 case SIOCSIFBRDADDR: 3924 case SIOCGIFNETMASK: 3925 case SIOCSIFNETMASK: 3926 case SIOCGIFDSTADDR: 3927 case SIOCSIFDSTADDR: 3928 case SIOCSIFFLAGS: 3929 return inet_dgram_ops.ioctl(sock, cmd, arg); 3930 #endif 3931 3932 default: 3933 return -ENOIOCTLCMD; 3934 } 3935 return 0; 3936 } 3937 3938 static unsigned int packet_poll(struct file *file, struct socket *sock, 3939 poll_table *wait) 3940 { 3941 struct sock *sk = sock->sk; 3942 struct packet_sock *po = pkt_sk(sk); 3943 unsigned int mask = datagram_poll(file, sock, wait); 3944 3945 spin_lock_bh(&sk->sk_receive_queue.lock); 3946 if (po->rx_ring.pg_vec) { 3947 if (!packet_previous_rx_frame(po, &po->rx_ring, 3948 TP_STATUS_KERNEL)) 3949 mask |= POLLIN | POLLRDNORM; 3950 } 3951 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 3952 po->pressure = 0; 3953 spin_unlock_bh(&sk->sk_receive_queue.lock); 3954 spin_lock_bh(&sk->sk_write_queue.lock); 3955 if (po->tx_ring.pg_vec) { 3956 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3957 mask |= POLLOUT | POLLWRNORM; 3958 } 3959 spin_unlock_bh(&sk->sk_write_queue.lock); 3960 return mask; 3961 } 3962 3963 3964 /* Dirty? Well, I still did not learn better way to account 3965 * for user mmaps. 3966 */ 3967 3968 static void packet_mm_open(struct vm_area_struct *vma) 3969 { 3970 struct file *file = vma->vm_file; 3971 struct socket *sock = file->private_data; 3972 struct sock *sk = sock->sk; 3973 3974 if (sk) 3975 atomic_inc(&pkt_sk(sk)->mapped); 3976 } 3977 3978 static void packet_mm_close(struct vm_area_struct *vma) 3979 { 3980 struct file *file = vma->vm_file; 3981 struct socket *sock = file->private_data; 3982 struct sock *sk = sock->sk; 3983 3984 if (sk) 3985 atomic_dec(&pkt_sk(sk)->mapped); 3986 } 3987 3988 static const struct vm_operations_struct packet_mmap_ops = { 3989 .open = packet_mm_open, 3990 .close = packet_mm_close, 3991 }; 3992 3993 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3994 unsigned int len) 3995 { 3996 int i; 3997 3998 for (i = 0; i < len; i++) { 3999 if (likely(pg_vec[i].buffer)) { 4000 if (is_vmalloc_addr(pg_vec[i].buffer)) 4001 vfree(pg_vec[i].buffer); 4002 else 4003 free_pages((unsigned long)pg_vec[i].buffer, 4004 order); 4005 pg_vec[i].buffer = NULL; 4006 } 4007 } 4008 kfree(pg_vec); 4009 } 4010 4011 static char *alloc_one_pg_vec_page(unsigned long order) 4012 { 4013 char *buffer; 4014 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4015 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4016 4017 buffer = (char *) __get_free_pages(gfp_flags, order); 4018 if (buffer) 4019 return buffer; 4020 4021 /* __get_free_pages failed, fall back to vmalloc */ 4022 buffer = vzalloc((1 << order) * PAGE_SIZE); 4023 if (buffer) 4024 return buffer; 4025 4026 /* vmalloc failed, lets dig into swap here */ 4027 gfp_flags &= ~__GFP_NORETRY; 4028 buffer = (char *) __get_free_pages(gfp_flags, order); 4029 if (buffer) 4030 return buffer; 4031 4032 /* complete and utter failure */ 4033 return NULL; 4034 } 4035 4036 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4037 { 4038 unsigned int block_nr = req->tp_block_nr; 4039 struct pgv *pg_vec; 4040 int i; 4041 4042 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 4043 if (unlikely(!pg_vec)) 4044 goto out; 4045 4046 for (i = 0; i < block_nr; i++) { 4047 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4048 if (unlikely(!pg_vec[i].buffer)) 4049 goto out_free_pgvec; 4050 } 4051 4052 out: 4053 return pg_vec; 4054 4055 out_free_pgvec: 4056 free_pg_vec(pg_vec, order, block_nr); 4057 pg_vec = NULL; 4058 goto out; 4059 } 4060 4061 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4062 int closing, int tx_ring) 4063 { 4064 struct pgv *pg_vec = NULL; 4065 struct packet_sock *po = pkt_sk(sk); 4066 int was_running, order = 0; 4067 struct packet_ring_buffer *rb; 4068 struct sk_buff_head *rb_queue; 4069 __be16 num; 4070 int err = -EINVAL; 4071 /* Added to avoid minimal code churn */ 4072 struct tpacket_req *req = &req_u->req; 4073 4074 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 4075 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 4076 WARN(1, "Tx-ring is not supported.\n"); 4077 goto out; 4078 } 4079 4080 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4081 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4082 4083 err = -EBUSY; 4084 if (!closing) { 4085 if (atomic_read(&po->mapped)) 4086 goto out; 4087 if (packet_read_pending(rb)) 4088 goto out; 4089 } 4090 4091 if (req->tp_block_nr) { 4092 /* Sanity tests and some calculations */ 4093 err = -EBUSY; 4094 if (unlikely(rb->pg_vec)) 4095 goto out; 4096 4097 switch (po->tp_version) { 4098 case TPACKET_V1: 4099 po->tp_hdrlen = TPACKET_HDRLEN; 4100 break; 4101 case TPACKET_V2: 4102 po->tp_hdrlen = TPACKET2_HDRLEN; 4103 break; 4104 case TPACKET_V3: 4105 po->tp_hdrlen = TPACKET3_HDRLEN; 4106 break; 4107 } 4108 4109 err = -EINVAL; 4110 if (unlikely((int)req->tp_block_size <= 0)) 4111 goto out; 4112 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4113 goto out; 4114 if (po->tp_version >= TPACKET_V3 && 4115 (int)(req->tp_block_size - 4116 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) 4117 goto out; 4118 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 4119 po->tp_reserve)) 4120 goto out; 4121 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4122 goto out; 4123 4124 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4125 if (unlikely(rb->frames_per_block == 0)) 4126 goto out; 4127 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4128 req->tp_frame_nr)) 4129 goto out; 4130 4131 err = -ENOMEM; 4132 order = get_order(req->tp_block_size); 4133 pg_vec = alloc_pg_vec(req, order); 4134 if (unlikely(!pg_vec)) 4135 goto out; 4136 switch (po->tp_version) { 4137 case TPACKET_V3: 4138 /* Transmit path is not supported. We checked 4139 * it above but just being paranoid 4140 */ 4141 if (!tx_ring) 4142 init_prb_bdqc(po, rb, pg_vec, req_u); 4143 break; 4144 default: 4145 break; 4146 } 4147 } 4148 /* Done */ 4149 else { 4150 err = -EINVAL; 4151 if (unlikely(req->tp_frame_nr)) 4152 goto out; 4153 } 4154 4155 lock_sock(sk); 4156 4157 /* Detach socket from network */ 4158 spin_lock(&po->bind_lock); 4159 was_running = po->running; 4160 num = po->num; 4161 if (was_running) { 4162 po->num = 0; 4163 __unregister_prot_hook(sk, false); 4164 } 4165 spin_unlock(&po->bind_lock); 4166 4167 synchronize_net(); 4168 4169 err = -EBUSY; 4170 mutex_lock(&po->pg_vec_lock); 4171 if (closing || atomic_read(&po->mapped) == 0) { 4172 err = 0; 4173 spin_lock_bh(&rb_queue->lock); 4174 swap(rb->pg_vec, pg_vec); 4175 rb->frame_max = (req->tp_frame_nr - 1); 4176 rb->head = 0; 4177 rb->frame_size = req->tp_frame_size; 4178 spin_unlock_bh(&rb_queue->lock); 4179 4180 swap(rb->pg_vec_order, order); 4181 swap(rb->pg_vec_len, req->tp_block_nr); 4182 4183 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4184 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4185 tpacket_rcv : packet_rcv; 4186 skb_queue_purge(rb_queue); 4187 if (atomic_read(&po->mapped)) 4188 pr_err("packet_mmap: vma is busy: %d\n", 4189 atomic_read(&po->mapped)); 4190 } 4191 mutex_unlock(&po->pg_vec_lock); 4192 4193 spin_lock(&po->bind_lock); 4194 if (was_running) { 4195 po->num = num; 4196 register_prot_hook(sk); 4197 } 4198 spin_unlock(&po->bind_lock); 4199 if (closing && (po->tp_version > TPACKET_V2)) { 4200 /* Because we don't support block-based V3 on tx-ring */ 4201 if (!tx_ring) 4202 prb_shutdown_retire_blk_timer(po, rb_queue); 4203 } 4204 release_sock(sk); 4205 4206 if (pg_vec) 4207 free_pg_vec(pg_vec, order, req->tp_block_nr); 4208 out: 4209 return err; 4210 } 4211 4212 static int packet_mmap(struct file *file, struct socket *sock, 4213 struct vm_area_struct *vma) 4214 { 4215 struct sock *sk = sock->sk; 4216 struct packet_sock *po = pkt_sk(sk); 4217 unsigned long size, expected_size; 4218 struct packet_ring_buffer *rb; 4219 unsigned long start; 4220 int err = -EINVAL; 4221 int i; 4222 4223 if (vma->vm_pgoff) 4224 return -EINVAL; 4225 4226 mutex_lock(&po->pg_vec_lock); 4227 4228 expected_size = 0; 4229 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4230 if (rb->pg_vec) { 4231 expected_size += rb->pg_vec_len 4232 * rb->pg_vec_pages 4233 * PAGE_SIZE; 4234 } 4235 } 4236 4237 if (expected_size == 0) 4238 goto out; 4239 4240 size = vma->vm_end - vma->vm_start; 4241 if (size != expected_size) 4242 goto out; 4243 4244 start = vma->vm_start; 4245 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4246 if (rb->pg_vec == NULL) 4247 continue; 4248 4249 for (i = 0; i < rb->pg_vec_len; i++) { 4250 struct page *page; 4251 void *kaddr = rb->pg_vec[i].buffer; 4252 int pg_num; 4253 4254 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4255 page = pgv_to_page(kaddr); 4256 err = vm_insert_page(vma, start, page); 4257 if (unlikely(err)) 4258 goto out; 4259 start += PAGE_SIZE; 4260 kaddr += PAGE_SIZE; 4261 } 4262 } 4263 } 4264 4265 atomic_inc(&po->mapped); 4266 vma->vm_ops = &packet_mmap_ops; 4267 err = 0; 4268 4269 out: 4270 mutex_unlock(&po->pg_vec_lock); 4271 return err; 4272 } 4273 4274 static const struct proto_ops packet_ops_spkt = { 4275 .family = PF_PACKET, 4276 .owner = THIS_MODULE, 4277 .release = packet_release, 4278 .bind = packet_bind_spkt, 4279 .connect = sock_no_connect, 4280 .socketpair = sock_no_socketpair, 4281 .accept = sock_no_accept, 4282 .getname = packet_getname_spkt, 4283 .poll = datagram_poll, 4284 .ioctl = packet_ioctl, 4285 .listen = sock_no_listen, 4286 .shutdown = sock_no_shutdown, 4287 .setsockopt = sock_no_setsockopt, 4288 .getsockopt = sock_no_getsockopt, 4289 .sendmsg = packet_sendmsg_spkt, 4290 .recvmsg = packet_recvmsg, 4291 .mmap = sock_no_mmap, 4292 .sendpage = sock_no_sendpage, 4293 }; 4294 4295 static const struct proto_ops packet_ops = { 4296 .family = PF_PACKET, 4297 .owner = THIS_MODULE, 4298 .release = packet_release, 4299 .bind = packet_bind, 4300 .connect = sock_no_connect, 4301 .socketpair = sock_no_socketpair, 4302 .accept = sock_no_accept, 4303 .getname = packet_getname, 4304 .poll = packet_poll, 4305 .ioctl = packet_ioctl, 4306 .listen = sock_no_listen, 4307 .shutdown = sock_no_shutdown, 4308 .setsockopt = packet_setsockopt, 4309 .getsockopt = packet_getsockopt, 4310 .sendmsg = packet_sendmsg, 4311 .recvmsg = packet_recvmsg, 4312 .mmap = packet_mmap, 4313 .sendpage = sock_no_sendpage, 4314 }; 4315 4316 static const struct net_proto_family packet_family_ops = { 4317 .family = PF_PACKET, 4318 .create = packet_create, 4319 .owner = THIS_MODULE, 4320 }; 4321 4322 static struct notifier_block packet_netdev_notifier = { 4323 .notifier_call = packet_notifier, 4324 }; 4325 4326 #ifdef CONFIG_PROC_FS 4327 4328 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4329 __acquires(RCU) 4330 { 4331 struct net *net = seq_file_net(seq); 4332 4333 rcu_read_lock(); 4334 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4335 } 4336 4337 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4338 { 4339 struct net *net = seq_file_net(seq); 4340 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4341 } 4342 4343 static void packet_seq_stop(struct seq_file *seq, void *v) 4344 __releases(RCU) 4345 { 4346 rcu_read_unlock(); 4347 } 4348 4349 static int packet_seq_show(struct seq_file *seq, void *v) 4350 { 4351 if (v == SEQ_START_TOKEN) 4352 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4353 else { 4354 struct sock *s = sk_entry(v); 4355 const struct packet_sock *po = pkt_sk(s); 4356 4357 seq_printf(seq, 4358 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4359 s, 4360 atomic_read(&s->sk_refcnt), 4361 s->sk_type, 4362 ntohs(po->num), 4363 po->ifindex, 4364 po->running, 4365 atomic_read(&s->sk_rmem_alloc), 4366 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4367 sock_i_ino(s)); 4368 } 4369 4370 return 0; 4371 } 4372 4373 static const struct seq_operations packet_seq_ops = { 4374 .start = packet_seq_start, 4375 .next = packet_seq_next, 4376 .stop = packet_seq_stop, 4377 .show = packet_seq_show, 4378 }; 4379 4380 static int packet_seq_open(struct inode *inode, struct file *file) 4381 { 4382 return seq_open_net(inode, file, &packet_seq_ops, 4383 sizeof(struct seq_net_private)); 4384 } 4385 4386 static const struct file_operations packet_seq_fops = { 4387 .owner = THIS_MODULE, 4388 .open = packet_seq_open, 4389 .read = seq_read, 4390 .llseek = seq_lseek, 4391 .release = seq_release_net, 4392 }; 4393 4394 #endif 4395 4396 static int __net_init packet_net_init(struct net *net) 4397 { 4398 mutex_init(&net->packet.sklist_lock); 4399 INIT_HLIST_HEAD(&net->packet.sklist); 4400 4401 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4402 return -ENOMEM; 4403 4404 return 0; 4405 } 4406 4407 static void __net_exit packet_net_exit(struct net *net) 4408 { 4409 remove_proc_entry("packet", net->proc_net); 4410 } 4411 4412 static struct pernet_operations packet_net_ops = { 4413 .init = packet_net_init, 4414 .exit = packet_net_exit, 4415 }; 4416 4417 4418 static void __exit packet_exit(void) 4419 { 4420 unregister_netdevice_notifier(&packet_netdev_notifier); 4421 unregister_pernet_subsys(&packet_net_ops); 4422 sock_unregister(PF_PACKET); 4423 proto_unregister(&packet_proto); 4424 } 4425 4426 static int __init packet_init(void) 4427 { 4428 int rc = proto_register(&packet_proto, 0); 4429 4430 if (rc != 0) 4431 goto out; 4432 4433 sock_register(&packet_family_ops); 4434 register_pernet_subsys(&packet_net_ops); 4435 register_netdevice_notifier(&packet_netdev_notifier); 4436 out: 4437 return rc; 4438 } 4439 4440 module_init(packet_init); 4441 module_exit(packet_exit); 4442 MODULE_LICENSE("GPL"); 4443 MODULE_ALIAS_NETPROTO(PF_PACKET); 4444