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(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 packet_sock *po; 1443 unsigned int idx; 1444 1445 if (!net_eq(dev_net(dev), read_pnet(&f->net)) || 1446 !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(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 (ptype->af_packet_priv == (void *)((struct packet_sock *)sk)->fanout) 1523 return true; 1524 1525 return false; 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); 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 const struct proto_ops packet_ops; 1745 1746 static const struct proto_ops packet_ops_spkt; 1747 1748 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1749 struct packet_type *pt, struct net_device *orig_dev) 1750 { 1751 struct sock *sk; 1752 struct sockaddr_pkt *spkt; 1753 1754 /* 1755 * When we registered the protocol we saved the socket in the data 1756 * field for just this event. 1757 */ 1758 1759 sk = pt->af_packet_priv; 1760 1761 /* 1762 * Yank back the headers [hope the device set this 1763 * right or kerboom...] 1764 * 1765 * Incoming packets have ll header pulled, 1766 * push it back. 1767 * 1768 * For outgoing ones skb->data == skb_mac_header(skb) 1769 * so that this procedure is noop. 1770 */ 1771 1772 if (skb->pkt_type == PACKET_LOOPBACK) 1773 goto out; 1774 1775 if (!net_eq(dev_net(dev), sock_net(sk))) 1776 goto out; 1777 1778 skb = skb_share_check(skb, GFP_ATOMIC); 1779 if (skb == NULL) 1780 goto oom; 1781 1782 /* drop any routing info */ 1783 skb_dst_drop(skb); 1784 1785 /* drop conntrack reference */ 1786 nf_reset(skb); 1787 1788 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1789 1790 skb_push(skb, skb->data - skb_mac_header(skb)); 1791 1792 /* 1793 * The SOCK_PACKET socket receives _all_ frames. 1794 */ 1795 1796 spkt->spkt_family = dev->type; 1797 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1798 spkt->spkt_protocol = skb->protocol; 1799 1800 /* 1801 * Charge the memory to the socket. This is done specifically 1802 * to prevent sockets using all the memory up. 1803 */ 1804 1805 if (sock_queue_rcv_skb(sk, skb) == 0) 1806 return 0; 1807 1808 out: 1809 kfree_skb(skb); 1810 oom: 1811 return 0; 1812 } 1813 1814 1815 /* 1816 * Output a raw packet to a device layer. This bypasses all the other 1817 * protocol layers and you must therefore supply it with a complete frame 1818 */ 1819 1820 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1821 size_t len) 1822 { 1823 struct sock *sk = sock->sk; 1824 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1825 struct sk_buff *skb = NULL; 1826 struct net_device *dev; 1827 __be16 proto = 0; 1828 int err; 1829 int extra_len = 0; 1830 1831 /* 1832 * Get and verify the address. 1833 */ 1834 1835 if (saddr) { 1836 if (msg->msg_namelen < sizeof(struct sockaddr)) 1837 return -EINVAL; 1838 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1839 proto = saddr->spkt_protocol; 1840 } else 1841 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1842 1843 /* 1844 * Find the device first to size check it 1845 */ 1846 1847 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1848 retry: 1849 rcu_read_lock(); 1850 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1851 err = -ENODEV; 1852 if (dev == NULL) 1853 goto out_unlock; 1854 1855 err = -ENETDOWN; 1856 if (!(dev->flags & IFF_UP)) 1857 goto out_unlock; 1858 1859 /* 1860 * You may not queue a frame bigger than the mtu. This is the lowest level 1861 * raw protocol and you must do your own fragmentation at this level. 1862 */ 1863 1864 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1865 if (!netif_supports_nofcs(dev)) { 1866 err = -EPROTONOSUPPORT; 1867 goto out_unlock; 1868 } 1869 extra_len = 4; /* We're doing our own CRC */ 1870 } 1871 1872 err = -EMSGSIZE; 1873 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1874 goto out_unlock; 1875 1876 if (!skb) { 1877 size_t reserved = LL_RESERVED_SPACE(dev); 1878 int tlen = dev->needed_tailroom; 1879 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1880 1881 rcu_read_unlock(); 1882 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1883 if (skb == NULL) 1884 return -ENOBUFS; 1885 /* FIXME: Save some space for broken drivers that write a hard 1886 * header at transmission time by themselves. PPP is the notable 1887 * one here. This should really be fixed at the driver level. 1888 */ 1889 skb_reserve(skb, reserved); 1890 skb_reset_network_header(skb); 1891 1892 /* Try to align data part correctly */ 1893 if (hhlen) { 1894 skb->data -= hhlen; 1895 skb->tail -= hhlen; 1896 if (len < hhlen) 1897 skb_reset_network_header(skb); 1898 } 1899 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1900 if (err) 1901 goto out_free; 1902 goto retry; 1903 } 1904 1905 if (len > (dev->mtu + dev->hard_header_len + extra_len)) { 1906 /* Earlier code assumed this would be a VLAN pkt, 1907 * double-check this now that we have the actual 1908 * packet in hand. 1909 */ 1910 struct ethhdr *ehdr; 1911 skb_reset_mac_header(skb); 1912 ehdr = eth_hdr(skb); 1913 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 1914 err = -EMSGSIZE; 1915 goto out_unlock; 1916 } 1917 } 1918 1919 skb->protocol = proto; 1920 skb->dev = dev; 1921 skb->priority = sk->sk_priority; 1922 skb->mark = sk->sk_mark; 1923 1924 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 1925 1926 if (unlikely(extra_len == 4)) 1927 skb->no_fcs = 1; 1928 1929 skb_probe_transport_header(skb, 0); 1930 1931 dev_queue_xmit(skb); 1932 rcu_read_unlock(); 1933 return len; 1934 1935 out_unlock: 1936 rcu_read_unlock(); 1937 out_free: 1938 kfree_skb(skb); 1939 return err; 1940 } 1941 1942 static unsigned int run_filter(const struct sk_buff *skb, 1943 const struct sock *sk, 1944 unsigned int res) 1945 { 1946 struct sk_filter *filter; 1947 1948 rcu_read_lock(); 1949 filter = rcu_dereference(sk->sk_filter); 1950 if (filter != NULL) 1951 res = SK_RUN_FILTER(filter, skb); 1952 rcu_read_unlock(); 1953 1954 return res; 1955 } 1956 1957 /* 1958 * This function makes lazy skb cloning in hope that most of packets 1959 * are discarded by BPF. 1960 * 1961 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 1962 * and skb->cb are mangled. It works because (and until) packets 1963 * falling here are owned by current CPU. Output packets are cloned 1964 * by dev_queue_xmit_nit(), input packets are processed by net_bh 1965 * sequencially, so that if we return skb to original state on exit, 1966 * we will not harm anyone. 1967 */ 1968 1969 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 1970 struct packet_type *pt, struct net_device *orig_dev) 1971 { 1972 struct sock *sk; 1973 struct sockaddr_ll *sll; 1974 struct packet_sock *po; 1975 u8 *skb_head = skb->data; 1976 int skb_len = skb->len; 1977 unsigned int snaplen, res; 1978 1979 if (skb->pkt_type == PACKET_LOOPBACK) 1980 goto drop; 1981 1982 sk = pt->af_packet_priv; 1983 po = pkt_sk(sk); 1984 1985 if (!net_eq(dev_net(dev), sock_net(sk))) 1986 goto drop; 1987 1988 skb->dev = dev; 1989 1990 if (dev->header_ops) { 1991 /* The device has an explicit notion of ll header, 1992 * exported to higher levels. 1993 * 1994 * Otherwise, the device hides details of its frame 1995 * structure, so that corresponding packet head is 1996 * never delivered to user. 1997 */ 1998 if (sk->sk_type != SOCK_DGRAM) 1999 skb_push(skb, skb->data - skb_mac_header(skb)); 2000 else if (skb->pkt_type == PACKET_OUTGOING) { 2001 /* Special case: outgoing packets have ll header at head */ 2002 skb_pull(skb, skb_network_offset(skb)); 2003 } 2004 } 2005 2006 snaplen = skb->len; 2007 2008 res = run_filter(skb, sk, snaplen); 2009 if (!res) 2010 goto drop_n_restore; 2011 if (snaplen > res) 2012 snaplen = res; 2013 2014 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2015 goto drop_n_acct; 2016 2017 if (skb_shared(skb)) { 2018 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2019 if (nskb == NULL) 2020 goto drop_n_acct; 2021 2022 if (skb_head != skb->data) { 2023 skb->data = skb_head; 2024 skb->len = skb_len; 2025 } 2026 consume_skb(skb); 2027 skb = nskb; 2028 } 2029 2030 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2031 2032 sll = &PACKET_SKB_CB(skb)->sa.ll; 2033 sll->sll_hatype = dev->type; 2034 sll->sll_pkttype = skb->pkt_type; 2035 if (unlikely(po->origdev)) 2036 sll->sll_ifindex = orig_dev->ifindex; 2037 else 2038 sll->sll_ifindex = dev->ifindex; 2039 2040 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2041 2042 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2043 * Use their space for storing the original skb length. 2044 */ 2045 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2046 2047 if (pskb_trim(skb, snaplen)) 2048 goto drop_n_acct; 2049 2050 skb_set_owner_r(skb, sk); 2051 skb->dev = NULL; 2052 skb_dst_drop(skb); 2053 2054 /* drop conntrack reference */ 2055 nf_reset(skb); 2056 2057 spin_lock(&sk->sk_receive_queue.lock); 2058 po->stats.stats1.tp_packets++; 2059 sock_skb_set_dropcount(sk, skb); 2060 __skb_queue_tail(&sk->sk_receive_queue, skb); 2061 spin_unlock(&sk->sk_receive_queue.lock); 2062 sk->sk_data_ready(sk); 2063 return 0; 2064 2065 drop_n_acct: 2066 spin_lock(&sk->sk_receive_queue.lock); 2067 po->stats.stats1.tp_drops++; 2068 atomic_inc(&sk->sk_drops); 2069 spin_unlock(&sk->sk_receive_queue.lock); 2070 2071 drop_n_restore: 2072 if (skb_head != skb->data && skb_shared(skb)) { 2073 skb->data = skb_head; 2074 skb->len = skb_len; 2075 } 2076 drop: 2077 consume_skb(skb); 2078 return 0; 2079 } 2080 2081 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2082 struct packet_type *pt, struct net_device *orig_dev) 2083 { 2084 struct sock *sk; 2085 struct packet_sock *po; 2086 struct sockaddr_ll *sll; 2087 union tpacket_uhdr h; 2088 u8 *skb_head = skb->data; 2089 int skb_len = skb->len; 2090 unsigned int snaplen, res; 2091 unsigned long status = TP_STATUS_USER; 2092 unsigned short macoff, netoff, hdrlen; 2093 struct sk_buff *copy_skb = NULL; 2094 struct timespec ts; 2095 __u32 ts_status; 2096 2097 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2098 * We may add members to them until current aligned size without forcing 2099 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2100 */ 2101 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2102 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2103 2104 if (skb->pkt_type == PACKET_LOOPBACK) 2105 goto drop; 2106 2107 sk = pt->af_packet_priv; 2108 po = pkt_sk(sk); 2109 2110 if (!net_eq(dev_net(dev), sock_net(sk))) 2111 goto drop; 2112 2113 if (dev->header_ops) { 2114 if (sk->sk_type != SOCK_DGRAM) 2115 skb_push(skb, skb->data - skb_mac_header(skb)); 2116 else if (skb->pkt_type == PACKET_OUTGOING) { 2117 /* Special case: outgoing packets have ll header at head */ 2118 skb_pull(skb, skb_network_offset(skb)); 2119 } 2120 } 2121 2122 snaplen = skb->len; 2123 2124 res = run_filter(skb, sk, snaplen); 2125 if (!res) 2126 goto drop_n_restore; 2127 2128 if (skb->ip_summed == CHECKSUM_PARTIAL) 2129 status |= TP_STATUS_CSUMNOTREADY; 2130 else if (skb->pkt_type != PACKET_OUTGOING && 2131 (skb->ip_summed == CHECKSUM_COMPLETE || 2132 skb_csum_unnecessary(skb))) 2133 status |= TP_STATUS_CSUM_VALID; 2134 2135 if (snaplen > res) 2136 snaplen = res; 2137 2138 if (sk->sk_type == SOCK_DGRAM) { 2139 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2140 po->tp_reserve; 2141 } else { 2142 unsigned int maclen = skb_network_offset(skb); 2143 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2144 (maclen < 16 ? 16 : maclen)) + 2145 po->tp_reserve; 2146 macoff = netoff - maclen; 2147 } 2148 if (po->tp_version <= TPACKET_V2) { 2149 if (macoff + snaplen > po->rx_ring.frame_size) { 2150 if (po->copy_thresh && 2151 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2152 if (skb_shared(skb)) { 2153 copy_skb = skb_clone(skb, GFP_ATOMIC); 2154 } else { 2155 copy_skb = skb_get(skb); 2156 skb_head = skb->data; 2157 } 2158 if (copy_skb) 2159 skb_set_owner_r(copy_skb, sk); 2160 } 2161 snaplen = po->rx_ring.frame_size - macoff; 2162 if ((int)snaplen < 0) 2163 snaplen = 0; 2164 } 2165 } else if (unlikely(macoff + snaplen > 2166 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2167 u32 nval; 2168 2169 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2170 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2171 snaplen, nval, macoff); 2172 snaplen = nval; 2173 if (unlikely((int)snaplen < 0)) { 2174 snaplen = 0; 2175 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2176 } 2177 } 2178 spin_lock(&sk->sk_receive_queue.lock); 2179 h.raw = packet_current_rx_frame(po, skb, 2180 TP_STATUS_KERNEL, (macoff+snaplen)); 2181 if (!h.raw) 2182 goto ring_is_full; 2183 if (po->tp_version <= TPACKET_V2) { 2184 packet_increment_rx_head(po, &po->rx_ring); 2185 /* 2186 * LOSING will be reported till you read the stats, 2187 * because it's COR - Clear On Read. 2188 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2189 * at packet level. 2190 */ 2191 if (po->stats.stats1.tp_drops) 2192 status |= TP_STATUS_LOSING; 2193 } 2194 po->stats.stats1.tp_packets++; 2195 if (copy_skb) { 2196 status |= TP_STATUS_COPY; 2197 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2198 } 2199 spin_unlock(&sk->sk_receive_queue.lock); 2200 2201 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2202 2203 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 2204 getnstimeofday(&ts); 2205 2206 status |= ts_status; 2207 2208 switch (po->tp_version) { 2209 case TPACKET_V1: 2210 h.h1->tp_len = skb->len; 2211 h.h1->tp_snaplen = snaplen; 2212 h.h1->tp_mac = macoff; 2213 h.h1->tp_net = netoff; 2214 h.h1->tp_sec = ts.tv_sec; 2215 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2216 hdrlen = sizeof(*h.h1); 2217 break; 2218 case TPACKET_V2: 2219 h.h2->tp_len = skb->len; 2220 h.h2->tp_snaplen = snaplen; 2221 h.h2->tp_mac = macoff; 2222 h.h2->tp_net = netoff; 2223 h.h2->tp_sec = ts.tv_sec; 2224 h.h2->tp_nsec = ts.tv_nsec; 2225 if (skb_vlan_tag_present(skb)) { 2226 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2227 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2228 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2229 } else { 2230 h.h2->tp_vlan_tci = 0; 2231 h.h2->tp_vlan_tpid = 0; 2232 } 2233 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2234 hdrlen = sizeof(*h.h2); 2235 break; 2236 case TPACKET_V3: 2237 /* tp_nxt_offset,vlan are already populated above. 2238 * So DONT clear those fields here 2239 */ 2240 h.h3->tp_status |= status; 2241 h.h3->tp_len = skb->len; 2242 h.h3->tp_snaplen = snaplen; 2243 h.h3->tp_mac = macoff; 2244 h.h3->tp_net = netoff; 2245 h.h3->tp_sec = ts.tv_sec; 2246 h.h3->tp_nsec = ts.tv_nsec; 2247 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2248 hdrlen = sizeof(*h.h3); 2249 break; 2250 default: 2251 BUG(); 2252 } 2253 2254 sll = h.raw + TPACKET_ALIGN(hdrlen); 2255 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2256 sll->sll_family = AF_PACKET; 2257 sll->sll_hatype = dev->type; 2258 sll->sll_protocol = skb->protocol; 2259 sll->sll_pkttype = skb->pkt_type; 2260 if (unlikely(po->origdev)) 2261 sll->sll_ifindex = orig_dev->ifindex; 2262 else 2263 sll->sll_ifindex = dev->ifindex; 2264 2265 smp_mb(); 2266 2267 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2268 if (po->tp_version <= TPACKET_V2) { 2269 u8 *start, *end; 2270 2271 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2272 macoff + snaplen); 2273 2274 for (start = h.raw; start < end; start += PAGE_SIZE) 2275 flush_dcache_page(pgv_to_page(start)); 2276 } 2277 smp_wmb(); 2278 #endif 2279 2280 if (po->tp_version <= TPACKET_V2) { 2281 __packet_set_status(po, h.raw, status); 2282 sk->sk_data_ready(sk); 2283 } else { 2284 prb_clear_blk_fill_status(&po->rx_ring); 2285 } 2286 2287 drop_n_restore: 2288 if (skb_head != skb->data && skb_shared(skb)) { 2289 skb->data = skb_head; 2290 skb->len = skb_len; 2291 } 2292 drop: 2293 kfree_skb(skb); 2294 return 0; 2295 2296 ring_is_full: 2297 po->stats.stats1.tp_drops++; 2298 spin_unlock(&sk->sk_receive_queue.lock); 2299 2300 sk->sk_data_ready(sk); 2301 kfree_skb(copy_skb); 2302 goto drop_n_restore; 2303 } 2304 2305 static void tpacket_destruct_skb(struct sk_buff *skb) 2306 { 2307 struct packet_sock *po = pkt_sk(skb->sk); 2308 2309 if (likely(po->tx_ring.pg_vec)) { 2310 void *ph; 2311 __u32 ts; 2312 2313 ph = skb_shinfo(skb)->destructor_arg; 2314 packet_dec_pending(&po->tx_ring); 2315 2316 ts = __packet_set_timestamp(po, ph, skb); 2317 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2318 } 2319 2320 sock_wfree(skb); 2321 } 2322 2323 static bool ll_header_truncated(const struct net_device *dev, int len) 2324 { 2325 /* net device doesn't like empty head */ 2326 if (unlikely(len <= dev->hard_header_len)) { 2327 net_warn_ratelimited("%s: packet size is too short (%d <= %d)\n", 2328 current->comm, len, dev->hard_header_len); 2329 return true; 2330 } 2331 2332 return false; 2333 } 2334 2335 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2336 void *frame, struct net_device *dev, int size_max, 2337 __be16 proto, unsigned char *addr, int hlen) 2338 { 2339 union tpacket_uhdr ph; 2340 int to_write, offset, len, tp_len, nr_frags, len_max; 2341 struct socket *sock = po->sk.sk_socket; 2342 struct page *page; 2343 void *data; 2344 int err; 2345 2346 ph.raw = frame; 2347 2348 skb->protocol = proto; 2349 skb->dev = dev; 2350 skb->priority = po->sk.sk_priority; 2351 skb->mark = po->sk.sk_mark; 2352 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags); 2353 skb_shinfo(skb)->destructor_arg = ph.raw; 2354 2355 switch (po->tp_version) { 2356 case TPACKET_V2: 2357 tp_len = ph.h2->tp_len; 2358 break; 2359 default: 2360 tp_len = ph.h1->tp_len; 2361 break; 2362 } 2363 if (unlikely(tp_len > size_max)) { 2364 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2365 return -EMSGSIZE; 2366 } 2367 2368 skb_reserve(skb, hlen); 2369 skb_reset_network_header(skb); 2370 2371 if (!packet_use_direct_xmit(po)) 2372 skb_probe_transport_header(skb, 0); 2373 if (unlikely(po->tp_tx_has_off)) { 2374 int off_min, off_max, off; 2375 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2376 off_max = po->tx_ring.frame_size - tp_len; 2377 if (sock->type == SOCK_DGRAM) { 2378 switch (po->tp_version) { 2379 case TPACKET_V2: 2380 off = ph.h2->tp_net; 2381 break; 2382 default: 2383 off = ph.h1->tp_net; 2384 break; 2385 } 2386 } else { 2387 switch (po->tp_version) { 2388 case TPACKET_V2: 2389 off = ph.h2->tp_mac; 2390 break; 2391 default: 2392 off = ph.h1->tp_mac; 2393 break; 2394 } 2395 } 2396 if (unlikely((off < off_min) || (off_max < off))) 2397 return -EINVAL; 2398 data = ph.raw + off; 2399 } else { 2400 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); 2401 } 2402 to_write = tp_len; 2403 2404 if (sock->type == SOCK_DGRAM) { 2405 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2406 NULL, tp_len); 2407 if (unlikely(err < 0)) 2408 return -EINVAL; 2409 } else if (dev->hard_header_len) { 2410 if (ll_header_truncated(dev, tp_len)) 2411 return -EINVAL; 2412 2413 skb_push(skb, dev->hard_header_len); 2414 err = skb_store_bits(skb, 0, data, 2415 dev->hard_header_len); 2416 if (unlikely(err)) 2417 return err; 2418 2419 data += dev->hard_header_len; 2420 to_write -= dev->hard_header_len; 2421 } 2422 2423 offset = offset_in_page(data); 2424 len_max = PAGE_SIZE - offset; 2425 len = ((to_write > len_max) ? len_max : to_write); 2426 2427 skb->data_len = to_write; 2428 skb->len += to_write; 2429 skb->truesize += to_write; 2430 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2431 2432 while (likely(to_write)) { 2433 nr_frags = skb_shinfo(skb)->nr_frags; 2434 2435 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2436 pr_err("Packet exceed the number of skb frags(%lu)\n", 2437 MAX_SKB_FRAGS); 2438 return -EFAULT; 2439 } 2440 2441 page = pgv_to_page(data); 2442 data += len; 2443 flush_dcache_page(page); 2444 get_page(page); 2445 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2446 to_write -= len; 2447 offset = 0; 2448 len_max = PAGE_SIZE; 2449 len = ((to_write > len_max) ? len_max : to_write); 2450 } 2451 2452 return tp_len; 2453 } 2454 2455 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2456 { 2457 struct sk_buff *skb; 2458 struct net_device *dev; 2459 __be16 proto; 2460 int err, reserve = 0; 2461 void *ph; 2462 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2463 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2464 int tp_len, size_max; 2465 unsigned char *addr; 2466 int len_sum = 0; 2467 int status = TP_STATUS_AVAILABLE; 2468 int hlen, tlen; 2469 2470 mutex_lock(&po->pg_vec_lock); 2471 2472 if (likely(saddr == NULL)) { 2473 dev = packet_cached_dev_get(po); 2474 proto = po->num; 2475 addr = NULL; 2476 } else { 2477 err = -EINVAL; 2478 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2479 goto out; 2480 if (msg->msg_namelen < (saddr->sll_halen 2481 + offsetof(struct sockaddr_ll, 2482 sll_addr))) 2483 goto out; 2484 proto = saddr->sll_protocol; 2485 addr = saddr->sll_addr; 2486 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2487 } 2488 2489 err = -ENXIO; 2490 if (unlikely(dev == NULL)) 2491 goto out; 2492 err = -ENETDOWN; 2493 if (unlikely(!(dev->flags & IFF_UP))) 2494 goto out_put; 2495 2496 reserve = dev->hard_header_len + VLAN_HLEN; 2497 size_max = po->tx_ring.frame_size 2498 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2499 2500 if (size_max > dev->mtu + reserve) 2501 size_max = dev->mtu + reserve; 2502 2503 do { 2504 ph = packet_current_frame(po, &po->tx_ring, 2505 TP_STATUS_SEND_REQUEST); 2506 if (unlikely(ph == NULL)) { 2507 if (need_wait && need_resched()) 2508 schedule(); 2509 continue; 2510 } 2511 2512 status = TP_STATUS_SEND_REQUEST; 2513 hlen = LL_RESERVED_SPACE(dev); 2514 tlen = dev->needed_tailroom; 2515 skb = sock_alloc_send_skb(&po->sk, 2516 hlen + tlen + sizeof(struct sockaddr_ll), 2517 !need_wait, &err); 2518 2519 if (unlikely(skb == NULL)) { 2520 /* we assume the socket was initially writeable ... */ 2521 if (likely(len_sum > 0)) 2522 err = len_sum; 2523 goto out_status; 2524 } 2525 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, 2526 addr, hlen); 2527 if (likely(tp_len >= 0) && 2528 tp_len > dev->mtu + dev->hard_header_len) { 2529 struct ethhdr *ehdr; 2530 /* Earlier code assumed this would be a VLAN pkt, 2531 * double-check this now that we have the actual 2532 * packet in hand. 2533 */ 2534 2535 skb_reset_mac_header(skb); 2536 ehdr = eth_hdr(skb); 2537 if (ehdr->h_proto != htons(ETH_P_8021Q)) 2538 tp_len = -EMSGSIZE; 2539 } 2540 if (unlikely(tp_len < 0)) { 2541 if (po->tp_loss) { 2542 __packet_set_status(po, ph, 2543 TP_STATUS_AVAILABLE); 2544 packet_increment_head(&po->tx_ring); 2545 kfree_skb(skb); 2546 continue; 2547 } else { 2548 status = TP_STATUS_WRONG_FORMAT; 2549 err = tp_len; 2550 goto out_status; 2551 } 2552 } 2553 2554 packet_pick_tx_queue(dev, skb); 2555 2556 skb->destructor = tpacket_destruct_skb; 2557 __packet_set_status(po, ph, TP_STATUS_SENDING); 2558 packet_inc_pending(&po->tx_ring); 2559 2560 status = TP_STATUS_SEND_REQUEST; 2561 err = po->xmit(skb); 2562 if (unlikely(err > 0)) { 2563 err = net_xmit_errno(err); 2564 if (err && __packet_get_status(po, ph) == 2565 TP_STATUS_AVAILABLE) { 2566 /* skb was destructed already */ 2567 skb = NULL; 2568 goto out_status; 2569 } 2570 /* 2571 * skb was dropped but not destructed yet; 2572 * let's treat it like congestion or err < 0 2573 */ 2574 err = 0; 2575 } 2576 packet_increment_head(&po->tx_ring); 2577 len_sum += tp_len; 2578 } while (likely((ph != NULL) || 2579 /* Note: packet_read_pending() might be slow if we have 2580 * to call it as it's per_cpu variable, but in fast-path 2581 * we already short-circuit the loop with the first 2582 * condition, and luckily don't have to go that path 2583 * anyway. 2584 */ 2585 (need_wait && packet_read_pending(&po->tx_ring)))); 2586 2587 err = len_sum; 2588 goto out_put; 2589 2590 out_status: 2591 __packet_set_status(po, ph, status); 2592 kfree_skb(skb); 2593 out_put: 2594 dev_put(dev); 2595 out: 2596 mutex_unlock(&po->pg_vec_lock); 2597 return err; 2598 } 2599 2600 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2601 size_t reserve, size_t len, 2602 size_t linear, int noblock, 2603 int *err) 2604 { 2605 struct sk_buff *skb; 2606 2607 /* Under a page? Don't bother with paged skb. */ 2608 if (prepad + len < PAGE_SIZE || !linear) 2609 linear = len; 2610 2611 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2612 err, 0); 2613 if (!skb) 2614 return NULL; 2615 2616 skb_reserve(skb, reserve); 2617 skb_put(skb, linear); 2618 skb->data_len = len - linear; 2619 skb->len += len - linear; 2620 2621 return skb; 2622 } 2623 2624 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2625 { 2626 struct sock *sk = sock->sk; 2627 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2628 struct sk_buff *skb; 2629 struct net_device *dev; 2630 __be16 proto; 2631 unsigned char *addr; 2632 int err, reserve = 0; 2633 struct virtio_net_hdr vnet_hdr = { 0 }; 2634 int offset = 0; 2635 int vnet_hdr_len; 2636 struct packet_sock *po = pkt_sk(sk); 2637 unsigned short gso_type = 0; 2638 int hlen, tlen; 2639 int extra_len = 0; 2640 ssize_t n; 2641 2642 /* 2643 * Get and verify the address. 2644 */ 2645 2646 if (likely(saddr == NULL)) { 2647 dev = packet_cached_dev_get(po); 2648 proto = po->num; 2649 addr = NULL; 2650 } else { 2651 err = -EINVAL; 2652 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2653 goto out; 2654 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2655 goto out; 2656 proto = saddr->sll_protocol; 2657 addr = saddr->sll_addr; 2658 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2659 } 2660 2661 err = -ENXIO; 2662 if (unlikely(dev == NULL)) 2663 goto out_unlock; 2664 err = -ENETDOWN; 2665 if (unlikely(!(dev->flags & IFF_UP))) 2666 goto out_unlock; 2667 2668 if (sock->type == SOCK_RAW) 2669 reserve = dev->hard_header_len; 2670 if (po->has_vnet_hdr) { 2671 vnet_hdr_len = sizeof(vnet_hdr); 2672 2673 err = -EINVAL; 2674 if (len < vnet_hdr_len) 2675 goto out_unlock; 2676 2677 len -= vnet_hdr_len; 2678 2679 err = -EFAULT; 2680 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter); 2681 if (n != vnet_hdr_len) 2682 goto out_unlock; 2683 2684 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2685 (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + 2686 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 > 2687 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len))) 2688 vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(), 2689 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + 2690 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2); 2691 2692 err = -EINVAL; 2693 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len) 2694 goto out_unlock; 2695 2696 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2697 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2698 case VIRTIO_NET_HDR_GSO_TCPV4: 2699 gso_type = SKB_GSO_TCPV4; 2700 break; 2701 case VIRTIO_NET_HDR_GSO_TCPV6: 2702 gso_type = SKB_GSO_TCPV6; 2703 break; 2704 case VIRTIO_NET_HDR_GSO_UDP: 2705 gso_type = SKB_GSO_UDP; 2706 break; 2707 default: 2708 goto out_unlock; 2709 } 2710 2711 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2712 gso_type |= SKB_GSO_TCP_ECN; 2713 2714 if (vnet_hdr.gso_size == 0) 2715 goto out_unlock; 2716 2717 } 2718 } 2719 2720 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2721 if (!netif_supports_nofcs(dev)) { 2722 err = -EPROTONOSUPPORT; 2723 goto out_unlock; 2724 } 2725 extra_len = 4; /* We're doing our own CRC */ 2726 } 2727 2728 err = -EMSGSIZE; 2729 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2730 goto out_unlock; 2731 2732 err = -ENOBUFS; 2733 hlen = LL_RESERVED_SPACE(dev); 2734 tlen = dev->needed_tailroom; 2735 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, 2736 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len), 2737 msg->msg_flags & MSG_DONTWAIT, &err); 2738 if (skb == NULL) 2739 goto out_unlock; 2740 2741 skb_set_network_header(skb, reserve); 2742 2743 err = -EINVAL; 2744 if (sock->type == SOCK_DGRAM) { 2745 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2746 if (unlikely(offset < 0)) 2747 goto out_free; 2748 } else { 2749 if (ll_header_truncated(dev, len)) 2750 goto out_free; 2751 } 2752 2753 /* Returns -EFAULT on error */ 2754 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2755 if (err) 2756 goto out_free; 2757 2758 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2759 2760 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2761 /* Earlier code assumed this would be a VLAN pkt, 2762 * double-check this now that we have the actual 2763 * packet in hand. 2764 */ 2765 struct ethhdr *ehdr; 2766 skb_reset_mac_header(skb); 2767 ehdr = eth_hdr(skb); 2768 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2769 err = -EMSGSIZE; 2770 goto out_free; 2771 } 2772 } 2773 2774 skb->protocol = proto; 2775 skb->dev = dev; 2776 skb->priority = sk->sk_priority; 2777 skb->mark = sk->sk_mark; 2778 2779 packet_pick_tx_queue(dev, skb); 2780 2781 if (po->has_vnet_hdr) { 2782 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2783 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start); 2784 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset); 2785 if (!skb_partial_csum_set(skb, s, o)) { 2786 err = -EINVAL; 2787 goto out_free; 2788 } 2789 } 2790 2791 skb_shinfo(skb)->gso_size = 2792 __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size); 2793 skb_shinfo(skb)->gso_type = gso_type; 2794 2795 /* Header must be checked, and gso_segs computed. */ 2796 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2797 skb_shinfo(skb)->gso_segs = 0; 2798 2799 len += vnet_hdr_len; 2800 } 2801 2802 if (!packet_use_direct_xmit(po)) 2803 skb_probe_transport_header(skb, reserve); 2804 if (unlikely(extra_len == 4)) 2805 skb->no_fcs = 1; 2806 2807 err = po->xmit(skb); 2808 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2809 goto out_unlock; 2810 2811 dev_put(dev); 2812 2813 return len; 2814 2815 out_free: 2816 kfree_skb(skb); 2817 out_unlock: 2818 if (dev) 2819 dev_put(dev); 2820 out: 2821 return err; 2822 } 2823 2824 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 2825 { 2826 struct sock *sk = sock->sk; 2827 struct packet_sock *po = pkt_sk(sk); 2828 2829 if (po->tx_ring.pg_vec) 2830 return tpacket_snd(po, msg); 2831 else 2832 return packet_snd(sock, msg, len); 2833 } 2834 2835 /* 2836 * Close a PACKET socket. This is fairly simple. We immediately go 2837 * to 'closed' state and remove our protocol entry in the device list. 2838 */ 2839 2840 static int packet_release(struct socket *sock) 2841 { 2842 struct sock *sk = sock->sk; 2843 struct packet_sock *po; 2844 struct net *net; 2845 union tpacket_req_u req_u; 2846 2847 if (!sk) 2848 return 0; 2849 2850 net = sock_net(sk); 2851 po = pkt_sk(sk); 2852 2853 mutex_lock(&net->packet.sklist_lock); 2854 sk_del_node_init_rcu(sk); 2855 mutex_unlock(&net->packet.sklist_lock); 2856 2857 preempt_disable(); 2858 sock_prot_inuse_add(net, sk->sk_prot, -1); 2859 preempt_enable(); 2860 2861 spin_lock(&po->bind_lock); 2862 unregister_prot_hook(sk, false); 2863 packet_cached_dev_reset(po); 2864 2865 if (po->prot_hook.dev) { 2866 dev_put(po->prot_hook.dev); 2867 po->prot_hook.dev = NULL; 2868 } 2869 spin_unlock(&po->bind_lock); 2870 2871 packet_flush_mclist(sk); 2872 2873 if (po->rx_ring.pg_vec) { 2874 memset(&req_u, 0, sizeof(req_u)); 2875 packet_set_ring(sk, &req_u, 1, 0); 2876 } 2877 2878 if (po->tx_ring.pg_vec) { 2879 memset(&req_u, 0, sizeof(req_u)); 2880 packet_set_ring(sk, &req_u, 1, 1); 2881 } 2882 2883 fanout_release(sk); 2884 2885 synchronize_net(); 2886 /* 2887 * Now the socket is dead. No more input will appear. 2888 */ 2889 sock_orphan(sk); 2890 sock->sk = NULL; 2891 2892 /* Purge queues */ 2893 2894 skb_queue_purge(&sk->sk_receive_queue); 2895 packet_free_pending(po); 2896 sk_refcnt_debug_release(sk); 2897 2898 sock_put(sk); 2899 return 0; 2900 } 2901 2902 /* 2903 * Attach a packet hook. 2904 */ 2905 2906 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto) 2907 { 2908 struct packet_sock *po = pkt_sk(sk); 2909 struct net_device *dev_curr; 2910 __be16 proto_curr; 2911 bool need_rehook; 2912 2913 if (po->fanout) { 2914 if (dev) 2915 dev_put(dev); 2916 2917 return -EINVAL; 2918 } 2919 2920 lock_sock(sk); 2921 spin_lock(&po->bind_lock); 2922 2923 proto_curr = po->prot_hook.type; 2924 dev_curr = po->prot_hook.dev; 2925 2926 need_rehook = proto_curr != proto || dev_curr != dev; 2927 2928 if (need_rehook) { 2929 unregister_prot_hook(sk, true); 2930 2931 po->num = proto; 2932 po->prot_hook.type = proto; 2933 po->prot_hook.dev = dev; 2934 2935 po->ifindex = dev ? dev->ifindex : 0; 2936 packet_cached_dev_assign(po, dev); 2937 } 2938 if (dev_curr) 2939 dev_put(dev_curr); 2940 2941 if (proto == 0 || !need_rehook) 2942 goto out_unlock; 2943 2944 if (!dev || (dev->flags & IFF_UP)) { 2945 register_prot_hook(sk); 2946 } else { 2947 sk->sk_err = ENETDOWN; 2948 if (!sock_flag(sk, SOCK_DEAD)) 2949 sk->sk_error_report(sk); 2950 } 2951 2952 out_unlock: 2953 spin_unlock(&po->bind_lock); 2954 release_sock(sk); 2955 return 0; 2956 } 2957 2958 /* 2959 * Bind a packet socket to a device 2960 */ 2961 2962 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 2963 int addr_len) 2964 { 2965 struct sock *sk = sock->sk; 2966 char name[15]; 2967 struct net_device *dev; 2968 int err = -ENODEV; 2969 2970 /* 2971 * Check legality 2972 */ 2973 2974 if (addr_len != sizeof(struct sockaddr)) 2975 return -EINVAL; 2976 strlcpy(name, uaddr->sa_data, sizeof(name)); 2977 2978 dev = dev_get_by_name(sock_net(sk), name); 2979 if (dev) 2980 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 2981 return err; 2982 } 2983 2984 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 2985 { 2986 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 2987 struct sock *sk = sock->sk; 2988 struct net_device *dev = NULL; 2989 int err; 2990 2991 2992 /* 2993 * Check legality 2994 */ 2995 2996 if (addr_len < sizeof(struct sockaddr_ll)) 2997 return -EINVAL; 2998 if (sll->sll_family != AF_PACKET) 2999 return -EINVAL; 3000 3001 if (sll->sll_ifindex) { 3002 err = -ENODEV; 3003 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); 3004 if (dev == NULL) 3005 goto out; 3006 } 3007 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 3008 3009 out: 3010 return err; 3011 } 3012 3013 static struct proto packet_proto = { 3014 .name = "PACKET", 3015 .owner = THIS_MODULE, 3016 .obj_size = sizeof(struct packet_sock), 3017 }; 3018 3019 /* 3020 * Create a packet of type SOCK_PACKET. 3021 */ 3022 3023 static int packet_create(struct net *net, struct socket *sock, int protocol, 3024 int kern) 3025 { 3026 struct sock *sk; 3027 struct packet_sock *po; 3028 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3029 int err; 3030 3031 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3032 return -EPERM; 3033 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3034 sock->type != SOCK_PACKET) 3035 return -ESOCKTNOSUPPORT; 3036 3037 sock->state = SS_UNCONNECTED; 3038 3039 err = -ENOBUFS; 3040 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3041 if (sk == NULL) 3042 goto out; 3043 3044 sock->ops = &packet_ops; 3045 if (sock->type == SOCK_PACKET) 3046 sock->ops = &packet_ops_spkt; 3047 3048 sock_init_data(sock, sk); 3049 3050 po = pkt_sk(sk); 3051 sk->sk_family = PF_PACKET; 3052 po->num = proto; 3053 po->xmit = dev_queue_xmit; 3054 3055 err = packet_alloc_pending(po); 3056 if (err) 3057 goto out2; 3058 3059 packet_cached_dev_reset(po); 3060 3061 sk->sk_destruct = packet_sock_destruct; 3062 sk_refcnt_debug_inc(sk); 3063 3064 /* 3065 * Attach a protocol block 3066 */ 3067 3068 spin_lock_init(&po->bind_lock); 3069 mutex_init(&po->pg_vec_lock); 3070 po->rollover = NULL; 3071 po->prot_hook.func = packet_rcv; 3072 3073 if (sock->type == SOCK_PACKET) 3074 po->prot_hook.func = packet_rcv_spkt; 3075 3076 po->prot_hook.af_packet_priv = sk; 3077 3078 if (proto) { 3079 po->prot_hook.type = proto; 3080 register_prot_hook(sk); 3081 } 3082 3083 mutex_lock(&net->packet.sklist_lock); 3084 sk_add_node_rcu(sk, &net->packet.sklist); 3085 mutex_unlock(&net->packet.sklist_lock); 3086 3087 preempt_disable(); 3088 sock_prot_inuse_add(net, &packet_proto, 1); 3089 preempt_enable(); 3090 3091 return 0; 3092 out2: 3093 sk_free(sk); 3094 out: 3095 return err; 3096 } 3097 3098 /* 3099 * Pull a packet from our receive queue and hand it to the user. 3100 * If necessary we block. 3101 */ 3102 3103 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3104 int flags) 3105 { 3106 struct sock *sk = sock->sk; 3107 struct sk_buff *skb; 3108 int copied, err; 3109 int vnet_hdr_len = 0; 3110 unsigned int origlen = 0; 3111 3112 err = -EINVAL; 3113 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3114 goto out; 3115 3116 #if 0 3117 /* What error should we return now? EUNATTACH? */ 3118 if (pkt_sk(sk)->ifindex < 0) 3119 return -ENODEV; 3120 #endif 3121 3122 if (flags & MSG_ERRQUEUE) { 3123 err = sock_recv_errqueue(sk, msg, len, 3124 SOL_PACKET, PACKET_TX_TIMESTAMP); 3125 goto out; 3126 } 3127 3128 /* 3129 * Call the generic datagram receiver. This handles all sorts 3130 * of horrible races and re-entrancy so we can forget about it 3131 * in the protocol layers. 3132 * 3133 * Now it will return ENETDOWN, if device have just gone down, 3134 * but then it will block. 3135 */ 3136 3137 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3138 3139 /* 3140 * An error occurred so return it. Because skb_recv_datagram() 3141 * handles the blocking we don't see and worry about blocking 3142 * retries. 3143 */ 3144 3145 if (skb == NULL) 3146 goto out; 3147 3148 if (pkt_sk(sk)->pressure) 3149 packet_rcv_has_room(pkt_sk(sk), NULL); 3150 3151 if (pkt_sk(sk)->has_vnet_hdr) { 3152 struct virtio_net_hdr vnet_hdr = { 0 }; 3153 3154 err = -EINVAL; 3155 vnet_hdr_len = sizeof(vnet_hdr); 3156 if (len < vnet_hdr_len) 3157 goto out_free; 3158 3159 len -= vnet_hdr_len; 3160 3161 if (skb_is_gso(skb)) { 3162 struct skb_shared_info *sinfo = skb_shinfo(skb); 3163 3164 /* This is a hint as to how much should be linear. */ 3165 vnet_hdr.hdr_len = 3166 __cpu_to_virtio16(vio_le(), skb_headlen(skb)); 3167 vnet_hdr.gso_size = 3168 __cpu_to_virtio16(vio_le(), sinfo->gso_size); 3169 if (sinfo->gso_type & SKB_GSO_TCPV4) 3170 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 3171 else if (sinfo->gso_type & SKB_GSO_TCPV6) 3172 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 3173 else if (sinfo->gso_type & SKB_GSO_UDP) 3174 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 3175 else if (sinfo->gso_type & SKB_GSO_FCOE) 3176 goto out_free; 3177 else 3178 BUG(); 3179 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 3180 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 3181 } else 3182 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 3183 3184 if (skb->ip_summed == CHECKSUM_PARTIAL) { 3185 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 3186 vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(), 3187 skb_checksum_start_offset(skb)); 3188 vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(), 3189 skb->csum_offset); 3190 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3191 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 3192 } /* else everything is zero */ 3193 3194 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len); 3195 if (err < 0) 3196 goto out_free; 3197 } 3198 3199 /* You lose any data beyond the buffer you gave. If it worries 3200 * a user program they can ask the device for its MTU 3201 * anyway. 3202 */ 3203 copied = skb->len; 3204 if (copied > len) { 3205 copied = len; 3206 msg->msg_flags |= MSG_TRUNC; 3207 } 3208 3209 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3210 if (err) 3211 goto out_free; 3212 3213 if (sock->type != SOCK_PACKET) { 3214 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3215 3216 /* Original length was stored in sockaddr_ll fields */ 3217 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3218 sll->sll_family = AF_PACKET; 3219 sll->sll_protocol = skb->protocol; 3220 } 3221 3222 sock_recv_ts_and_drops(msg, sk, skb); 3223 3224 if (msg->msg_name) { 3225 /* If the address length field is there to be filled 3226 * in, we fill it in now. 3227 */ 3228 if (sock->type == SOCK_PACKET) { 3229 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3230 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3231 } else { 3232 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3233 3234 msg->msg_namelen = sll->sll_halen + 3235 offsetof(struct sockaddr_ll, sll_addr); 3236 } 3237 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 3238 msg->msg_namelen); 3239 } 3240 3241 if (pkt_sk(sk)->auxdata) { 3242 struct tpacket_auxdata aux; 3243 3244 aux.tp_status = TP_STATUS_USER; 3245 if (skb->ip_summed == CHECKSUM_PARTIAL) 3246 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3247 else if (skb->pkt_type != PACKET_OUTGOING && 3248 (skb->ip_summed == CHECKSUM_COMPLETE || 3249 skb_csum_unnecessary(skb))) 3250 aux.tp_status |= TP_STATUS_CSUM_VALID; 3251 3252 aux.tp_len = origlen; 3253 aux.tp_snaplen = skb->len; 3254 aux.tp_mac = 0; 3255 aux.tp_net = skb_network_offset(skb); 3256 if (skb_vlan_tag_present(skb)) { 3257 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3258 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3259 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3260 } else { 3261 aux.tp_vlan_tci = 0; 3262 aux.tp_vlan_tpid = 0; 3263 } 3264 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3265 } 3266 3267 /* 3268 * Free or return the buffer as appropriate. Again this 3269 * hides all the races and re-entrancy issues from us. 3270 */ 3271 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3272 3273 out_free: 3274 skb_free_datagram(sk, skb); 3275 out: 3276 return err; 3277 } 3278 3279 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3280 int *uaddr_len, int peer) 3281 { 3282 struct net_device *dev; 3283 struct sock *sk = sock->sk; 3284 3285 if (peer) 3286 return -EOPNOTSUPP; 3287 3288 uaddr->sa_family = AF_PACKET; 3289 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3290 rcu_read_lock(); 3291 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3292 if (dev) 3293 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3294 rcu_read_unlock(); 3295 *uaddr_len = sizeof(*uaddr); 3296 3297 return 0; 3298 } 3299 3300 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3301 int *uaddr_len, int peer) 3302 { 3303 struct net_device *dev; 3304 struct sock *sk = sock->sk; 3305 struct packet_sock *po = pkt_sk(sk); 3306 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3307 3308 if (peer) 3309 return -EOPNOTSUPP; 3310 3311 sll->sll_family = AF_PACKET; 3312 sll->sll_ifindex = po->ifindex; 3313 sll->sll_protocol = po->num; 3314 sll->sll_pkttype = 0; 3315 rcu_read_lock(); 3316 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3317 if (dev) { 3318 sll->sll_hatype = dev->type; 3319 sll->sll_halen = dev->addr_len; 3320 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3321 } else { 3322 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3323 sll->sll_halen = 0; 3324 } 3325 rcu_read_unlock(); 3326 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3327 3328 return 0; 3329 } 3330 3331 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3332 int what) 3333 { 3334 switch (i->type) { 3335 case PACKET_MR_MULTICAST: 3336 if (i->alen != dev->addr_len) 3337 return -EINVAL; 3338 if (what > 0) 3339 return dev_mc_add(dev, i->addr); 3340 else 3341 return dev_mc_del(dev, i->addr); 3342 break; 3343 case PACKET_MR_PROMISC: 3344 return dev_set_promiscuity(dev, what); 3345 case PACKET_MR_ALLMULTI: 3346 return dev_set_allmulti(dev, what); 3347 case PACKET_MR_UNICAST: 3348 if (i->alen != dev->addr_len) 3349 return -EINVAL; 3350 if (what > 0) 3351 return dev_uc_add(dev, i->addr); 3352 else 3353 return dev_uc_del(dev, i->addr); 3354 break; 3355 default: 3356 break; 3357 } 3358 return 0; 3359 } 3360 3361 static void packet_dev_mclist_delete(struct net_device *dev, 3362 struct packet_mclist **mlp) 3363 { 3364 struct packet_mclist *ml; 3365 3366 while ((ml = *mlp) != NULL) { 3367 if (ml->ifindex == dev->ifindex) { 3368 packet_dev_mc(dev, ml, -1); 3369 *mlp = ml->next; 3370 kfree(ml); 3371 } else 3372 mlp = &ml->next; 3373 } 3374 } 3375 3376 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3377 { 3378 struct packet_sock *po = pkt_sk(sk); 3379 struct packet_mclist *ml, *i; 3380 struct net_device *dev; 3381 int err; 3382 3383 rtnl_lock(); 3384 3385 err = -ENODEV; 3386 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3387 if (!dev) 3388 goto done; 3389 3390 err = -EINVAL; 3391 if (mreq->mr_alen > dev->addr_len) 3392 goto done; 3393 3394 err = -ENOBUFS; 3395 i = kmalloc(sizeof(*i), GFP_KERNEL); 3396 if (i == NULL) 3397 goto done; 3398 3399 err = 0; 3400 for (ml = po->mclist; ml; ml = ml->next) { 3401 if (ml->ifindex == mreq->mr_ifindex && 3402 ml->type == mreq->mr_type && 3403 ml->alen == mreq->mr_alen && 3404 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3405 ml->count++; 3406 /* Free the new element ... */ 3407 kfree(i); 3408 goto done; 3409 } 3410 } 3411 3412 i->type = mreq->mr_type; 3413 i->ifindex = mreq->mr_ifindex; 3414 i->alen = mreq->mr_alen; 3415 memcpy(i->addr, mreq->mr_address, i->alen); 3416 i->count = 1; 3417 i->next = po->mclist; 3418 po->mclist = i; 3419 err = packet_dev_mc(dev, i, 1); 3420 if (err) { 3421 po->mclist = i->next; 3422 kfree(i); 3423 } 3424 3425 done: 3426 rtnl_unlock(); 3427 return err; 3428 } 3429 3430 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3431 { 3432 struct packet_mclist *ml, **mlp; 3433 3434 rtnl_lock(); 3435 3436 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3437 if (ml->ifindex == mreq->mr_ifindex && 3438 ml->type == mreq->mr_type && 3439 ml->alen == mreq->mr_alen && 3440 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3441 if (--ml->count == 0) { 3442 struct net_device *dev; 3443 *mlp = ml->next; 3444 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3445 if (dev) 3446 packet_dev_mc(dev, ml, -1); 3447 kfree(ml); 3448 } 3449 break; 3450 } 3451 } 3452 rtnl_unlock(); 3453 return 0; 3454 } 3455 3456 static void packet_flush_mclist(struct sock *sk) 3457 { 3458 struct packet_sock *po = pkt_sk(sk); 3459 struct packet_mclist *ml; 3460 3461 if (!po->mclist) 3462 return; 3463 3464 rtnl_lock(); 3465 while ((ml = po->mclist) != NULL) { 3466 struct net_device *dev; 3467 3468 po->mclist = ml->next; 3469 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3470 if (dev != NULL) 3471 packet_dev_mc(dev, ml, -1); 3472 kfree(ml); 3473 } 3474 rtnl_unlock(); 3475 } 3476 3477 static int 3478 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3479 { 3480 struct sock *sk = sock->sk; 3481 struct packet_sock *po = pkt_sk(sk); 3482 int ret; 3483 3484 if (level != SOL_PACKET) 3485 return -ENOPROTOOPT; 3486 3487 switch (optname) { 3488 case PACKET_ADD_MEMBERSHIP: 3489 case PACKET_DROP_MEMBERSHIP: 3490 { 3491 struct packet_mreq_max mreq; 3492 int len = optlen; 3493 memset(&mreq, 0, sizeof(mreq)); 3494 if (len < sizeof(struct packet_mreq)) 3495 return -EINVAL; 3496 if (len > sizeof(mreq)) 3497 len = sizeof(mreq); 3498 if (copy_from_user(&mreq, optval, len)) 3499 return -EFAULT; 3500 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3501 return -EINVAL; 3502 if (optname == PACKET_ADD_MEMBERSHIP) 3503 ret = packet_mc_add(sk, &mreq); 3504 else 3505 ret = packet_mc_drop(sk, &mreq); 3506 return ret; 3507 } 3508 3509 case PACKET_RX_RING: 3510 case PACKET_TX_RING: 3511 { 3512 union tpacket_req_u req_u; 3513 int len; 3514 3515 switch (po->tp_version) { 3516 case TPACKET_V1: 3517 case TPACKET_V2: 3518 len = sizeof(req_u.req); 3519 break; 3520 case TPACKET_V3: 3521 default: 3522 len = sizeof(req_u.req3); 3523 break; 3524 } 3525 if (optlen < len) 3526 return -EINVAL; 3527 if (pkt_sk(sk)->has_vnet_hdr) 3528 return -EINVAL; 3529 if (copy_from_user(&req_u.req, optval, len)) 3530 return -EFAULT; 3531 return packet_set_ring(sk, &req_u, 0, 3532 optname == PACKET_TX_RING); 3533 } 3534 case PACKET_COPY_THRESH: 3535 { 3536 int val; 3537 3538 if (optlen != sizeof(val)) 3539 return -EINVAL; 3540 if (copy_from_user(&val, optval, sizeof(val))) 3541 return -EFAULT; 3542 3543 pkt_sk(sk)->copy_thresh = val; 3544 return 0; 3545 } 3546 case PACKET_VERSION: 3547 { 3548 int val; 3549 3550 if (optlen != sizeof(val)) 3551 return -EINVAL; 3552 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3553 return -EBUSY; 3554 if (copy_from_user(&val, optval, sizeof(val))) 3555 return -EFAULT; 3556 switch (val) { 3557 case TPACKET_V1: 3558 case TPACKET_V2: 3559 case TPACKET_V3: 3560 po->tp_version = val; 3561 return 0; 3562 default: 3563 return -EINVAL; 3564 } 3565 } 3566 case PACKET_RESERVE: 3567 { 3568 unsigned int val; 3569 3570 if (optlen != sizeof(val)) 3571 return -EINVAL; 3572 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3573 return -EBUSY; 3574 if (copy_from_user(&val, optval, sizeof(val))) 3575 return -EFAULT; 3576 po->tp_reserve = val; 3577 return 0; 3578 } 3579 case PACKET_LOSS: 3580 { 3581 unsigned int val; 3582 3583 if (optlen != sizeof(val)) 3584 return -EINVAL; 3585 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3586 return -EBUSY; 3587 if (copy_from_user(&val, optval, sizeof(val))) 3588 return -EFAULT; 3589 po->tp_loss = !!val; 3590 return 0; 3591 } 3592 case PACKET_AUXDATA: 3593 { 3594 int val; 3595 3596 if (optlen < sizeof(val)) 3597 return -EINVAL; 3598 if (copy_from_user(&val, optval, sizeof(val))) 3599 return -EFAULT; 3600 3601 po->auxdata = !!val; 3602 return 0; 3603 } 3604 case PACKET_ORIGDEV: 3605 { 3606 int val; 3607 3608 if (optlen < sizeof(val)) 3609 return -EINVAL; 3610 if (copy_from_user(&val, optval, sizeof(val))) 3611 return -EFAULT; 3612 3613 po->origdev = !!val; 3614 return 0; 3615 } 3616 case PACKET_VNET_HDR: 3617 { 3618 int val; 3619 3620 if (sock->type != SOCK_RAW) 3621 return -EINVAL; 3622 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3623 return -EBUSY; 3624 if (optlen < sizeof(val)) 3625 return -EINVAL; 3626 if (copy_from_user(&val, optval, sizeof(val))) 3627 return -EFAULT; 3628 3629 po->has_vnet_hdr = !!val; 3630 return 0; 3631 } 3632 case PACKET_TIMESTAMP: 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->tp_tstamp = val; 3642 return 0; 3643 } 3644 case PACKET_FANOUT: 3645 { 3646 int val; 3647 3648 if (optlen != sizeof(val)) 3649 return -EINVAL; 3650 if (copy_from_user(&val, optval, sizeof(val))) 3651 return -EFAULT; 3652 3653 return fanout_add(sk, val & 0xffff, val >> 16); 3654 } 3655 case PACKET_FANOUT_DATA: 3656 { 3657 if (!po->fanout) 3658 return -EINVAL; 3659 3660 return fanout_set_data(po, optval, optlen); 3661 } 3662 case PACKET_TX_HAS_OFF: 3663 { 3664 unsigned int val; 3665 3666 if (optlen != sizeof(val)) 3667 return -EINVAL; 3668 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3669 return -EBUSY; 3670 if (copy_from_user(&val, optval, sizeof(val))) 3671 return -EFAULT; 3672 po->tp_tx_has_off = !!val; 3673 return 0; 3674 } 3675 case PACKET_QDISC_BYPASS: 3676 { 3677 int val; 3678 3679 if (optlen != sizeof(val)) 3680 return -EINVAL; 3681 if (copy_from_user(&val, optval, sizeof(val))) 3682 return -EFAULT; 3683 3684 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3685 return 0; 3686 } 3687 default: 3688 return -ENOPROTOOPT; 3689 } 3690 } 3691 3692 static int packet_getsockopt(struct socket *sock, int level, int optname, 3693 char __user *optval, int __user *optlen) 3694 { 3695 int len; 3696 int val, lv = sizeof(val); 3697 struct sock *sk = sock->sk; 3698 struct packet_sock *po = pkt_sk(sk); 3699 void *data = &val; 3700 union tpacket_stats_u st; 3701 struct tpacket_rollover_stats rstats; 3702 3703 if (level != SOL_PACKET) 3704 return -ENOPROTOOPT; 3705 3706 if (get_user(len, optlen)) 3707 return -EFAULT; 3708 3709 if (len < 0) 3710 return -EINVAL; 3711 3712 switch (optname) { 3713 case PACKET_STATISTICS: 3714 spin_lock_bh(&sk->sk_receive_queue.lock); 3715 memcpy(&st, &po->stats, sizeof(st)); 3716 memset(&po->stats, 0, sizeof(po->stats)); 3717 spin_unlock_bh(&sk->sk_receive_queue.lock); 3718 3719 if (po->tp_version == TPACKET_V3) { 3720 lv = sizeof(struct tpacket_stats_v3); 3721 st.stats3.tp_packets += st.stats3.tp_drops; 3722 data = &st.stats3; 3723 } else { 3724 lv = sizeof(struct tpacket_stats); 3725 st.stats1.tp_packets += st.stats1.tp_drops; 3726 data = &st.stats1; 3727 } 3728 3729 break; 3730 case PACKET_AUXDATA: 3731 val = po->auxdata; 3732 break; 3733 case PACKET_ORIGDEV: 3734 val = po->origdev; 3735 break; 3736 case PACKET_VNET_HDR: 3737 val = po->has_vnet_hdr; 3738 break; 3739 case PACKET_VERSION: 3740 val = po->tp_version; 3741 break; 3742 case PACKET_HDRLEN: 3743 if (len > sizeof(int)) 3744 len = sizeof(int); 3745 if (copy_from_user(&val, optval, len)) 3746 return -EFAULT; 3747 switch (val) { 3748 case TPACKET_V1: 3749 val = sizeof(struct tpacket_hdr); 3750 break; 3751 case TPACKET_V2: 3752 val = sizeof(struct tpacket2_hdr); 3753 break; 3754 case TPACKET_V3: 3755 val = sizeof(struct tpacket3_hdr); 3756 break; 3757 default: 3758 return -EINVAL; 3759 } 3760 break; 3761 case PACKET_RESERVE: 3762 val = po->tp_reserve; 3763 break; 3764 case PACKET_LOSS: 3765 val = po->tp_loss; 3766 break; 3767 case PACKET_TIMESTAMP: 3768 val = po->tp_tstamp; 3769 break; 3770 case PACKET_FANOUT: 3771 val = (po->fanout ? 3772 ((u32)po->fanout->id | 3773 ((u32)po->fanout->type << 16) | 3774 ((u32)po->fanout->flags << 24)) : 3775 0); 3776 break; 3777 case PACKET_ROLLOVER_STATS: 3778 if (!po->rollover) 3779 return -EINVAL; 3780 rstats.tp_all = atomic_long_read(&po->rollover->num); 3781 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 3782 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 3783 data = &rstats; 3784 lv = sizeof(rstats); 3785 break; 3786 case PACKET_TX_HAS_OFF: 3787 val = po->tp_tx_has_off; 3788 break; 3789 case PACKET_QDISC_BYPASS: 3790 val = packet_use_direct_xmit(po); 3791 break; 3792 default: 3793 return -ENOPROTOOPT; 3794 } 3795 3796 if (len > lv) 3797 len = lv; 3798 if (put_user(len, optlen)) 3799 return -EFAULT; 3800 if (copy_to_user(optval, data, len)) 3801 return -EFAULT; 3802 return 0; 3803 } 3804 3805 3806 static int packet_notifier(struct notifier_block *this, 3807 unsigned long msg, void *ptr) 3808 { 3809 struct sock *sk; 3810 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3811 struct net *net = dev_net(dev); 3812 3813 rcu_read_lock(); 3814 sk_for_each_rcu(sk, &net->packet.sklist) { 3815 struct packet_sock *po = pkt_sk(sk); 3816 3817 switch (msg) { 3818 case NETDEV_UNREGISTER: 3819 if (po->mclist) 3820 packet_dev_mclist_delete(dev, &po->mclist); 3821 /* fallthrough */ 3822 3823 case NETDEV_DOWN: 3824 if (dev->ifindex == po->ifindex) { 3825 spin_lock(&po->bind_lock); 3826 if (po->running) { 3827 __unregister_prot_hook(sk, false); 3828 sk->sk_err = ENETDOWN; 3829 if (!sock_flag(sk, SOCK_DEAD)) 3830 sk->sk_error_report(sk); 3831 } 3832 if (msg == NETDEV_UNREGISTER) { 3833 packet_cached_dev_reset(po); 3834 po->ifindex = -1; 3835 if (po->prot_hook.dev) 3836 dev_put(po->prot_hook.dev); 3837 po->prot_hook.dev = NULL; 3838 } 3839 spin_unlock(&po->bind_lock); 3840 } 3841 break; 3842 case NETDEV_UP: 3843 if (dev->ifindex == po->ifindex) { 3844 spin_lock(&po->bind_lock); 3845 if (po->num) 3846 register_prot_hook(sk); 3847 spin_unlock(&po->bind_lock); 3848 } 3849 break; 3850 } 3851 } 3852 rcu_read_unlock(); 3853 return NOTIFY_DONE; 3854 } 3855 3856 3857 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3858 unsigned long arg) 3859 { 3860 struct sock *sk = sock->sk; 3861 3862 switch (cmd) { 3863 case SIOCOUTQ: 3864 { 3865 int amount = sk_wmem_alloc_get(sk); 3866 3867 return put_user(amount, (int __user *)arg); 3868 } 3869 case SIOCINQ: 3870 { 3871 struct sk_buff *skb; 3872 int amount = 0; 3873 3874 spin_lock_bh(&sk->sk_receive_queue.lock); 3875 skb = skb_peek(&sk->sk_receive_queue); 3876 if (skb) 3877 amount = skb->len; 3878 spin_unlock_bh(&sk->sk_receive_queue.lock); 3879 return put_user(amount, (int __user *)arg); 3880 } 3881 case SIOCGSTAMP: 3882 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3883 case SIOCGSTAMPNS: 3884 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3885 3886 #ifdef CONFIG_INET 3887 case SIOCADDRT: 3888 case SIOCDELRT: 3889 case SIOCDARP: 3890 case SIOCGARP: 3891 case SIOCSARP: 3892 case SIOCGIFADDR: 3893 case SIOCSIFADDR: 3894 case SIOCGIFBRDADDR: 3895 case SIOCSIFBRDADDR: 3896 case SIOCGIFNETMASK: 3897 case SIOCSIFNETMASK: 3898 case SIOCGIFDSTADDR: 3899 case SIOCSIFDSTADDR: 3900 case SIOCSIFFLAGS: 3901 return inet_dgram_ops.ioctl(sock, cmd, arg); 3902 #endif 3903 3904 default: 3905 return -ENOIOCTLCMD; 3906 } 3907 return 0; 3908 } 3909 3910 static unsigned int packet_poll(struct file *file, struct socket *sock, 3911 poll_table *wait) 3912 { 3913 struct sock *sk = sock->sk; 3914 struct packet_sock *po = pkt_sk(sk); 3915 unsigned int mask = datagram_poll(file, sock, wait); 3916 3917 spin_lock_bh(&sk->sk_receive_queue.lock); 3918 if (po->rx_ring.pg_vec) { 3919 if (!packet_previous_rx_frame(po, &po->rx_ring, 3920 TP_STATUS_KERNEL)) 3921 mask |= POLLIN | POLLRDNORM; 3922 } 3923 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 3924 po->pressure = 0; 3925 spin_unlock_bh(&sk->sk_receive_queue.lock); 3926 spin_lock_bh(&sk->sk_write_queue.lock); 3927 if (po->tx_ring.pg_vec) { 3928 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3929 mask |= POLLOUT | POLLWRNORM; 3930 } 3931 spin_unlock_bh(&sk->sk_write_queue.lock); 3932 return mask; 3933 } 3934 3935 3936 /* Dirty? Well, I still did not learn better way to account 3937 * for user mmaps. 3938 */ 3939 3940 static void packet_mm_open(struct vm_area_struct *vma) 3941 { 3942 struct file *file = vma->vm_file; 3943 struct socket *sock = file->private_data; 3944 struct sock *sk = sock->sk; 3945 3946 if (sk) 3947 atomic_inc(&pkt_sk(sk)->mapped); 3948 } 3949 3950 static void packet_mm_close(struct vm_area_struct *vma) 3951 { 3952 struct file *file = vma->vm_file; 3953 struct socket *sock = file->private_data; 3954 struct sock *sk = sock->sk; 3955 3956 if (sk) 3957 atomic_dec(&pkt_sk(sk)->mapped); 3958 } 3959 3960 static const struct vm_operations_struct packet_mmap_ops = { 3961 .open = packet_mm_open, 3962 .close = packet_mm_close, 3963 }; 3964 3965 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3966 unsigned int len) 3967 { 3968 int i; 3969 3970 for (i = 0; i < len; i++) { 3971 if (likely(pg_vec[i].buffer)) { 3972 if (is_vmalloc_addr(pg_vec[i].buffer)) 3973 vfree(pg_vec[i].buffer); 3974 else 3975 free_pages((unsigned long)pg_vec[i].buffer, 3976 order); 3977 pg_vec[i].buffer = NULL; 3978 } 3979 } 3980 kfree(pg_vec); 3981 } 3982 3983 static char *alloc_one_pg_vec_page(unsigned long order) 3984 { 3985 char *buffer; 3986 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 3987 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 3988 3989 buffer = (char *) __get_free_pages(gfp_flags, order); 3990 if (buffer) 3991 return buffer; 3992 3993 /* __get_free_pages failed, fall back to vmalloc */ 3994 buffer = vzalloc((1 << order) * PAGE_SIZE); 3995 if (buffer) 3996 return buffer; 3997 3998 /* vmalloc failed, lets dig into swap here */ 3999 gfp_flags &= ~__GFP_NORETRY; 4000 buffer = (char *) __get_free_pages(gfp_flags, order); 4001 if (buffer) 4002 return buffer; 4003 4004 /* complete and utter failure */ 4005 return NULL; 4006 } 4007 4008 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4009 { 4010 unsigned int block_nr = req->tp_block_nr; 4011 struct pgv *pg_vec; 4012 int i; 4013 4014 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 4015 if (unlikely(!pg_vec)) 4016 goto out; 4017 4018 for (i = 0; i < block_nr; i++) { 4019 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4020 if (unlikely(!pg_vec[i].buffer)) 4021 goto out_free_pgvec; 4022 } 4023 4024 out: 4025 return pg_vec; 4026 4027 out_free_pgvec: 4028 free_pg_vec(pg_vec, order, block_nr); 4029 pg_vec = NULL; 4030 goto out; 4031 } 4032 4033 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4034 int closing, int tx_ring) 4035 { 4036 struct pgv *pg_vec = NULL; 4037 struct packet_sock *po = pkt_sk(sk); 4038 int was_running, order = 0; 4039 struct packet_ring_buffer *rb; 4040 struct sk_buff_head *rb_queue; 4041 __be16 num; 4042 int err = -EINVAL; 4043 /* Added to avoid minimal code churn */ 4044 struct tpacket_req *req = &req_u->req; 4045 4046 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 4047 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 4048 WARN(1, "Tx-ring is not supported.\n"); 4049 goto out; 4050 } 4051 4052 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4053 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4054 4055 err = -EBUSY; 4056 if (!closing) { 4057 if (atomic_read(&po->mapped)) 4058 goto out; 4059 if (packet_read_pending(rb)) 4060 goto out; 4061 } 4062 4063 if (req->tp_block_nr) { 4064 /* Sanity tests and some calculations */ 4065 err = -EBUSY; 4066 if (unlikely(rb->pg_vec)) 4067 goto out; 4068 4069 switch (po->tp_version) { 4070 case TPACKET_V1: 4071 po->tp_hdrlen = TPACKET_HDRLEN; 4072 break; 4073 case TPACKET_V2: 4074 po->tp_hdrlen = TPACKET2_HDRLEN; 4075 break; 4076 case TPACKET_V3: 4077 po->tp_hdrlen = TPACKET3_HDRLEN; 4078 break; 4079 } 4080 4081 err = -EINVAL; 4082 if (unlikely((int)req->tp_block_size <= 0)) 4083 goto out; 4084 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 4085 goto out; 4086 if (po->tp_version >= TPACKET_V3 && 4087 (int)(req->tp_block_size - 4088 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) 4089 goto out; 4090 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 4091 po->tp_reserve)) 4092 goto out; 4093 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4094 goto out; 4095 4096 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 4097 if (unlikely(rb->frames_per_block <= 0)) 4098 goto out; 4099 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4100 req->tp_frame_nr)) 4101 goto out; 4102 4103 err = -ENOMEM; 4104 order = get_order(req->tp_block_size); 4105 pg_vec = alloc_pg_vec(req, order); 4106 if (unlikely(!pg_vec)) 4107 goto out; 4108 switch (po->tp_version) { 4109 case TPACKET_V3: 4110 /* Transmit path is not supported. We checked 4111 * it above but just being paranoid 4112 */ 4113 if (!tx_ring) 4114 init_prb_bdqc(po, rb, pg_vec, req_u); 4115 break; 4116 default: 4117 break; 4118 } 4119 } 4120 /* Done */ 4121 else { 4122 err = -EINVAL; 4123 if (unlikely(req->tp_frame_nr)) 4124 goto out; 4125 } 4126 4127 lock_sock(sk); 4128 4129 /* Detach socket from network */ 4130 spin_lock(&po->bind_lock); 4131 was_running = po->running; 4132 num = po->num; 4133 if (was_running) { 4134 po->num = 0; 4135 __unregister_prot_hook(sk, false); 4136 } 4137 spin_unlock(&po->bind_lock); 4138 4139 synchronize_net(); 4140 4141 err = -EBUSY; 4142 mutex_lock(&po->pg_vec_lock); 4143 if (closing || atomic_read(&po->mapped) == 0) { 4144 err = 0; 4145 spin_lock_bh(&rb_queue->lock); 4146 swap(rb->pg_vec, pg_vec); 4147 rb->frame_max = (req->tp_frame_nr - 1); 4148 rb->head = 0; 4149 rb->frame_size = req->tp_frame_size; 4150 spin_unlock_bh(&rb_queue->lock); 4151 4152 swap(rb->pg_vec_order, order); 4153 swap(rb->pg_vec_len, req->tp_block_nr); 4154 4155 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4156 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4157 tpacket_rcv : packet_rcv; 4158 skb_queue_purge(rb_queue); 4159 if (atomic_read(&po->mapped)) 4160 pr_err("packet_mmap: vma is busy: %d\n", 4161 atomic_read(&po->mapped)); 4162 } 4163 mutex_unlock(&po->pg_vec_lock); 4164 4165 spin_lock(&po->bind_lock); 4166 if (was_running) { 4167 po->num = num; 4168 register_prot_hook(sk); 4169 } 4170 spin_unlock(&po->bind_lock); 4171 if (closing && (po->tp_version > TPACKET_V2)) { 4172 /* Because we don't support block-based V3 on tx-ring */ 4173 if (!tx_ring) 4174 prb_shutdown_retire_blk_timer(po, rb_queue); 4175 } 4176 release_sock(sk); 4177 4178 if (pg_vec) 4179 free_pg_vec(pg_vec, order, req->tp_block_nr); 4180 out: 4181 return err; 4182 } 4183 4184 static int packet_mmap(struct file *file, struct socket *sock, 4185 struct vm_area_struct *vma) 4186 { 4187 struct sock *sk = sock->sk; 4188 struct packet_sock *po = pkt_sk(sk); 4189 unsigned long size, expected_size; 4190 struct packet_ring_buffer *rb; 4191 unsigned long start; 4192 int err = -EINVAL; 4193 int i; 4194 4195 if (vma->vm_pgoff) 4196 return -EINVAL; 4197 4198 mutex_lock(&po->pg_vec_lock); 4199 4200 expected_size = 0; 4201 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4202 if (rb->pg_vec) { 4203 expected_size += rb->pg_vec_len 4204 * rb->pg_vec_pages 4205 * PAGE_SIZE; 4206 } 4207 } 4208 4209 if (expected_size == 0) 4210 goto out; 4211 4212 size = vma->vm_end - vma->vm_start; 4213 if (size != expected_size) 4214 goto out; 4215 4216 start = vma->vm_start; 4217 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4218 if (rb->pg_vec == NULL) 4219 continue; 4220 4221 for (i = 0; i < rb->pg_vec_len; i++) { 4222 struct page *page; 4223 void *kaddr = rb->pg_vec[i].buffer; 4224 int pg_num; 4225 4226 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4227 page = pgv_to_page(kaddr); 4228 err = vm_insert_page(vma, start, page); 4229 if (unlikely(err)) 4230 goto out; 4231 start += PAGE_SIZE; 4232 kaddr += PAGE_SIZE; 4233 } 4234 } 4235 } 4236 4237 atomic_inc(&po->mapped); 4238 vma->vm_ops = &packet_mmap_ops; 4239 err = 0; 4240 4241 out: 4242 mutex_unlock(&po->pg_vec_lock); 4243 return err; 4244 } 4245 4246 static const struct proto_ops packet_ops_spkt = { 4247 .family = PF_PACKET, 4248 .owner = THIS_MODULE, 4249 .release = packet_release, 4250 .bind = packet_bind_spkt, 4251 .connect = sock_no_connect, 4252 .socketpair = sock_no_socketpair, 4253 .accept = sock_no_accept, 4254 .getname = packet_getname_spkt, 4255 .poll = datagram_poll, 4256 .ioctl = packet_ioctl, 4257 .listen = sock_no_listen, 4258 .shutdown = sock_no_shutdown, 4259 .setsockopt = sock_no_setsockopt, 4260 .getsockopt = sock_no_getsockopt, 4261 .sendmsg = packet_sendmsg_spkt, 4262 .recvmsg = packet_recvmsg, 4263 .mmap = sock_no_mmap, 4264 .sendpage = sock_no_sendpage, 4265 }; 4266 4267 static const struct proto_ops packet_ops = { 4268 .family = PF_PACKET, 4269 .owner = THIS_MODULE, 4270 .release = packet_release, 4271 .bind = packet_bind, 4272 .connect = sock_no_connect, 4273 .socketpair = sock_no_socketpair, 4274 .accept = sock_no_accept, 4275 .getname = packet_getname, 4276 .poll = packet_poll, 4277 .ioctl = packet_ioctl, 4278 .listen = sock_no_listen, 4279 .shutdown = sock_no_shutdown, 4280 .setsockopt = packet_setsockopt, 4281 .getsockopt = packet_getsockopt, 4282 .sendmsg = packet_sendmsg, 4283 .recvmsg = packet_recvmsg, 4284 .mmap = packet_mmap, 4285 .sendpage = sock_no_sendpage, 4286 }; 4287 4288 static const struct net_proto_family packet_family_ops = { 4289 .family = PF_PACKET, 4290 .create = packet_create, 4291 .owner = THIS_MODULE, 4292 }; 4293 4294 static struct notifier_block packet_netdev_notifier = { 4295 .notifier_call = packet_notifier, 4296 }; 4297 4298 #ifdef CONFIG_PROC_FS 4299 4300 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4301 __acquires(RCU) 4302 { 4303 struct net *net = seq_file_net(seq); 4304 4305 rcu_read_lock(); 4306 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4307 } 4308 4309 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4310 { 4311 struct net *net = seq_file_net(seq); 4312 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4313 } 4314 4315 static void packet_seq_stop(struct seq_file *seq, void *v) 4316 __releases(RCU) 4317 { 4318 rcu_read_unlock(); 4319 } 4320 4321 static int packet_seq_show(struct seq_file *seq, void *v) 4322 { 4323 if (v == SEQ_START_TOKEN) 4324 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4325 else { 4326 struct sock *s = sk_entry(v); 4327 const struct packet_sock *po = pkt_sk(s); 4328 4329 seq_printf(seq, 4330 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4331 s, 4332 atomic_read(&s->sk_refcnt), 4333 s->sk_type, 4334 ntohs(po->num), 4335 po->ifindex, 4336 po->running, 4337 atomic_read(&s->sk_rmem_alloc), 4338 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4339 sock_i_ino(s)); 4340 } 4341 4342 return 0; 4343 } 4344 4345 static const struct seq_operations packet_seq_ops = { 4346 .start = packet_seq_start, 4347 .next = packet_seq_next, 4348 .stop = packet_seq_stop, 4349 .show = packet_seq_show, 4350 }; 4351 4352 static int packet_seq_open(struct inode *inode, struct file *file) 4353 { 4354 return seq_open_net(inode, file, &packet_seq_ops, 4355 sizeof(struct seq_net_private)); 4356 } 4357 4358 static const struct file_operations packet_seq_fops = { 4359 .owner = THIS_MODULE, 4360 .open = packet_seq_open, 4361 .read = seq_read, 4362 .llseek = seq_lseek, 4363 .release = seq_release_net, 4364 }; 4365 4366 #endif 4367 4368 static int __net_init packet_net_init(struct net *net) 4369 { 4370 mutex_init(&net->packet.sklist_lock); 4371 INIT_HLIST_HEAD(&net->packet.sklist); 4372 4373 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4374 return -ENOMEM; 4375 4376 return 0; 4377 } 4378 4379 static void __net_exit packet_net_exit(struct net *net) 4380 { 4381 remove_proc_entry("packet", net->proc_net); 4382 } 4383 4384 static struct pernet_operations packet_net_ops = { 4385 .init = packet_net_init, 4386 .exit = packet_net_exit, 4387 }; 4388 4389 4390 static void __exit packet_exit(void) 4391 { 4392 unregister_netdevice_notifier(&packet_netdev_notifier); 4393 unregister_pernet_subsys(&packet_net_ops); 4394 sock_unregister(PF_PACKET); 4395 proto_unregister(&packet_proto); 4396 } 4397 4398 static int __init packet_init(void) 4399 { 4400 int rc = proto_register(&packet_proto, 0); 4401 4402 if (rc != 0) 4403 goto out; 4404 4405 sock_register(&packet_family_ops); 4406 register_pernet_subsys(&packet_net_ops); 4407 register_netdevice_notifier(&packet_netdev_notifier); 4408 out: 4409 return rc; 4410 } 4411 4412 module_init(packet_init); 4413 module_exit(packet_exit); 4414 MODULE_LICENSE("GPL"); 4415 MODULE_ALIAS_NETPROTO(PF_PACKET); 4416