1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <asm/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/percpu.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 #include <linux/bpf.h> 96 97 #include "internal.h" 98 99 /* 100 Assumptions: 101 - if device has no dev->hard_header routine, it adds and removes ll header 102 inside itself. In this case ll header is invisible outside of device, 103 but higher levels still should reserve dev->hard_header_len. 104 Some devices are enough clever to reallocate skb, when header 105 will not fit to reserved space (tunnel), another ones are silly 106 (PPP). 107 - packet socket receives packets with pulled ll header, 108 so that SOCK_RAW should push it back. 109 110 On receive: 111 ----------- 112 113 Incoming, dev->hard_header!=NULL 114 mac_header -> ll header 115 data -> data 116 117 Outgoing, dev->hard_header!=NULL 118 mac_header -> ll header 119 data -> ll header 120 121 Incoming, dev->hard_header==NULL 122 mac_header -> UNKNOWN position. It is very likely, that it points to ll 123 header. PPP makes it, that is wrong, because introduce 124 assymetry between rx and tx paths. 125 data -> data 126 127 Outgoing, dev->hard_header==NULL 128 mac_header -> data. ll header is still not built! 129 data -> data 130 131 Resume 132 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 133 134 135 On transmit: 136 ------------ 137 138 dev->hard_header != NULL 139 mac_header -> ll header 140 data -> ll header 141 142 dev->hard_header == NULL (ll header is added by device, we cannot control it) 143 mac_header -> data 144 data -> data 145 146 We should set nh.raw on output to correct posistion, 147 packet classifier depends on it. 148 */ 149 150 /* Private packet socket structures. */ 151 152 /* identical to struct packet_mreq except it has 153 * a longer address field. 154 */ 155 struct packet_mreq_max { 156 int mr_ifindex; 157 unsigned short mr_type; 158 unsigned short mr_alen; 159 unsigned char mr_address[MAX_ADDR_LEN]; 160 }; 161 162 union tpacket_uhdr { 163 struct tpacket_hdr *h1; 164 struct tpacket2_hdr *h2; 165 struct tpacket3_hdr *h3; 166 void *raw; 167 }; 168 169 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 170 int closing, int tx_ring); 171 172 #define V3_ALIGNMENT (8) 173 174 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 175 176 #define BLK_PLUS_PRIV(sz_of_priv) \ 177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 178 179 #define PGV_FROM_VMALLOC 1 180 181 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 182 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 183 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 184 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 185 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 186 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 187 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 188 189 struct packet_sock; 190 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 192 struct packet_type *pt, struct net_device *orig_dev); 193 194 static void *packet_previous_frame(struct packet_sock *po, 195 struct packet_ring_buffer *rb, 196 int status); 197 static void packet_increment_head(struct packet_ring_buffer *buff); 198 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 199 struct tpacket_block_desc *); 200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 201 struct packet_sock *); 202 static void prb_retire_current_block(struct tpacket_kbdq_core *, 203 struct packet_sock *, unsigned int status); 204 static int prb_queue_frozen(struct tpacket_kbdq_core *); 205 static void prb_open_block(struct tpacket_kbdq_core *, 206 struct tpacket_block_desc *); 207 static void prb_retire_rx_blk_timer_expired(unsigned long); 208 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 209 static void prb_init_blk_timer(struct packet_sock *, 210 struct tpacket_kbdq_core *, 211 void (*func) (unsigned long)); 212 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 213 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 214 struct tpacket3_hdr *); 215 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 216 struct tpacket3_hdr *); 217 static void packet_flush_mclist(struct sock *sk); 218 219 struct packet_skb_cb { 220 union { 221 struct sockaddr_pkt pkt; 222 union { 223 /* Trick: alias skb original length with 224 * ll.sll_family and ll.protocol in order 225 * to save room. 226 */ 227 unsigned int origlen; 228 struct sockaddr_ll ll; 229 }; 230 } sa; 231 }; 232 233 #define vio_le() virtio_legacy_is_little_endian() 234 235 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 236 237 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 238 #define GET_PBLOCK_DESC(x, bid) \ 239 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 240 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 241 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 242 #define GET_NEXT_PRB_BLK_NUM(x) \ 243 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 244 ((x)->kactive_blk_num+1) : 0) 245 246 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 247 static void __fanout_link(struct sock *sk, struct packet_sock *po); 248 249 static int packet_direct_xmit(struct sk_buff *skb) 250 { 251 struct net_device *dev = skb->dev; 252 netdev_features_t features; 253 struct netdev_queue *txq; 254 int ret = NETDEV_TX_BUSY; 255 256 if (unlikely(!netif_running(dev) || 257 !netif_carrier_ok(dev))) 258 goto drop; 259 260 features = netif_skb_features(skb); 261 if (skb_needs_linearize(skb, features) && 262 __skb_linearize(skb)) 263 goto drop; 264 265 txq = skb_get_tx_queue(dev, skb); 266 267 local_bh_disable(); 268 269 HARD_TX_LOCK(dev, txq, smp_processor_id()); 270 if (!netif_xmit_frozen_or_drv_stopped(txq)) 271 ret = netdev_start_xmit(skb, dev, txq, false); 272 HARD_TX_UNLOCK(dev, txq); 273 274 local_bh_enable(); 275 276 if (!dev_xmit_complete(ret)) 277 kfree_skb(skb); 278 279 return ret; 280 drop: 281 atomic_long_inc(&dev->tx_dropped); 282 kfree_skb(skb); 283 return NET_XMIT_DROP; 284 } 285 286 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 287 { 288 struct net_device *dev; 289 290 rcu_read_lock(); 291 dev = rcu_dereference(po->cached_dev); 292 if (likely(dev)) 293 dev_hold(dev); 294 rcu_read_unlock(); 295 296 return dev; 297 } 298 299 static void packet_cached_dev_assign(struct packet_sock *po, 300 struct net_device *dev) 301 { 302 rcu_assign_pointer(po->cached_dev, dev); 303 } 304 305 static void packet_cached_dev_reset(struct packet_sock *po) 306 { 307 RCU_INIT_POINTER(po->cached_dev, NULL); 308 } 309 310 static bool packet_use_direct_xmit(const struct packet_sock *po) 311 { 312 return po->xmit == packet_direct_xmit; 313 } 314 315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 316 { 317 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues; 318 } 319 320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 321 { 322 const struct net_device_ops *ops = dev->netdev_ops; 323 u16 queue_index; 324 325 if (ops->ndo_select_queue) { 326 queue_index = ops->ndo_select_queue(dev, skb, NULL, 327 __packet_pick_tx_queue); 328 queue_index = netdev_cap_txqueue(dev, queue_index); 329 } else { 330 queue_index = __packet_pick_tx_queue(dev, skb); 331 } 332 333 skb_set_queue_mapping(skb, queue_index); 334 } 335 336 /* register_prot_hook must be invoked with the po->bind_lock held, 337 * or from a context in which asynchronous accesses to the packet 338 * socket is not possible (packet_create()). 339 */ 340 static void register_prot_hook(struct sock *sk) 341 { 342 struct packet_sock *po = pkt_sk(sk); 343 344 if (!po->running) { 345 if (po->fanout) 346 __fanout_link(sk, po); 347 else 348 dev_add_pack(&po->prot_hook); 349 350 sock_hold(sk); 351 po->running = 1; 352 } 353 } 354 355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 356 * held. If the sync parameter is true, we will temporarily drop 357 * the po->bind_lock and do a synchronize_net to make sure no 358 * asynchronous packet processing paths still refer to the elements 359 * of po->prot_hook. If the sync parameter is false, it is the 360 * callers responsibility to take care of this. 361 */ 362 static void __unregister_prot_hook(struct sock *sk, bool sync) 363 { 364 struct packet_sock *po = pkt_sk(sk); 365 366 po->running = 0; 367 368 if (po->fanout) 369 __fanout_unlink(sk, po); 370 else 371 __dev_remove_pack(&po->prot_hook); 372 373 __sock_put(sk); 374 375 if (sync) { 376 spin_unlock(&po->bind_lock); 377 synchronize_net(); 378 spin_lock(&po->bind_lock); 379 } 380 } 381 382 static void unregister_prot_hook(struct sock *sk, bool sync) 383 { 384 struct packet_sock *po = pkt_sk(sk); 385 386 if (po->running) 387 __unregister_prot_hook(sk, sync); 388 } 389 390 static inline struct page * __pure pgv_to_page(void *addr) 391 { 392 if (is_vmalloc_addr(addr)) 393 return vmalloc_to_page(addr); 394 return virt_to_page(addr); 395 } 396 397 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 398 { 399 union tpacket_uhdr h; 400 401 h.raw = frame; 402 switch (po->tp_version) { 403 case TPACKET_V1: 404 h.h1->tp_status = status; 405 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 406 break; 407 case TPACKET_V2: 408 h.h2->tp_status = status; 409 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 410 break; 411 case TPACKET_V3: 412 default: 413 WARN(1, "TPACKET version not supported.\n"); 414 BUG(); 415 } 416 417 smp_wmb(); 418 } 419 420 static int __packet_get_status(struct packet_sock *po, void *frame) 421 { 422 union tpacket_uhdr h; 423 424 smp_rmb(); 425 426 h.raw = frame; 427 switch (po->tp_version) { 428 case TPACKET_V1: 429 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 430 return h.h1->tp_status; 431 case TPACKET_V2: 432 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 433 return h.h2->tp_status; 434 case TPACKET_V3: 435 default: 436 WARN(1, "TPACKET version not supported.\n"); 437 BUG(); 438 return 0; 439 } 440 } 441 442 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 443 unsigned int flags) 444 { 445 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 446 447 if (shhwtstamps && 448 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 449 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 450 return TP_STATUS_TS_RAW_HARDWARE; 451 452 if (ktime_to_timespec_cond(skb->tstamp, ts)) 453 return TP_STATUS_TS_SOFTWARE; 454 455 return 0; 456 } 457 458 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 459 struct sk_buff *skb) 460 { 461 union tpacket_uhdr h; 462 struct timespec ts; 463 __u32 ts_status; 464 465 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 466 return 0; 467 468 h.raw = frame; 469 switch (po->tp_version) { 470 case TPACKET_V1: 471 h.h1->tp_sec = ts.tv_sec; 472 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 473 break; 474 case TPACKET_V2: 475 h.h2->tp_sec = ts.tv_sec; 476 h.h2->tp_nsec = ts.tv_nsec; 477 break; 478 case TPACKET_V3: 479 default: 480 WARN(1, "TPACKET version not supported.\n"); 481 BUG(); 482 } 483 484 /* one flush is safe, as both fields always lie on the same cacheline */ 485 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 486 smp_wmb(); 487 488 return ts_status; 489 } 490 491 static void *packet_lookup_frame(struct packet_sock *po, 492 struct packet_ring_buffer *rb, 493 unsigned int position, 494 int status) 495 { 496 unsigned int pg_vec_pos, frame_offset; 497 union tpacket_uhdr h; 498 499 pg_vec_pos = position / rb->frames_per_block; 500 frame_offset = position % rb->frames_per_block; 501 502 h.raw = rb->pg_vec[pg_vec_pos].buffer + 503 (frame_offset * rb->frame_size); 504 505 if (status != __packet_get_status(po, h.raw)) 506 return NULL; 507 508 return h.raw; 509 } 510 511 static void *packet_current_frame(struct packet_sock *po, 512 struct packet_ring_buffer *rb, 513 int status) 514 { 515 return packet_lookup_frame(po, rb, rb->head, status); 516 } 517 518 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 519 { 520 del_timer_sync(&pkc->retire_blk_timer); 521 } 522 523 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 524 struct sk_buff_head *rb_queue) 525 { 526 struct tpacket_kbdq_core *pkc; 527 528 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 529 530 spin_lock_bh(&rb_queue->lock); 531 pkc->delete_blk_timer = 1; 532 spin_unlock_bh(&rb_queue->lock); 533 534 prb_del_retire_blk_timer(pkc); 535 } 536 537 static void prb_init_blk_timer(struct packet_sock *po, 538 struct tpacket_kbdq_core *pkc, 539 void (*func) (unsigned long)) 540 { 541 init_timer(&pkc->retire_blk_timer); 542 pkc->retire_blk_timer.data = (long)po; 543 pkc->retire_blk_timer.function = func; 544 pkc->retire_blk_timer.expires = jiffies; 545 } 546 547 static void prb_setup_retire_blk_timer(struct packet_sock *po) 548 { 549 struct tpacket_kbdq_core *pkc; 550 551 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 552 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 553 } 554 555 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 556 int blk_size_in_bytes) 557 { 558 struct net_device *dev; 559 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 560 struct ethtool_cmd ecmd; 561 int err; 562 u32 speed; 563 564 rtnl_lock(); 565 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 566 if (unlikely(!dev)) { 567 rtnl_unlock(); 568 return DEFAULT_PRB_RETIRE_TOV; 569 } 570 err = __ethtool_get_settings(dev, &ecmd); 571 speed = ethtool_cmd_speed(&ecmd); 572 rtnl_unlock(); 573 if (!err) { 574 /* 575 * If the link speed is so slow you don't really 576 * need to worry about perf anyways 577 */ 578 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { 579 return DEFAULT_PRB_RETIRE_TOV; 580 } else { 581 msec = 1; 582 div = speed / 1000; 583 } 584 } 585 586 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 587 588 if (div) 589 mbits /= div; 590 591 tmo = mbits * msec; 592 593 if (div) 594 return tmo+1; 595 return tmo; 596 } 597 598 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 599 union tpacket_req_u *req_u) 600 { 601 p1->feature_req_word = req_u->req3.tp_feature_req_word; 602 } 603 604 static void init_prb_bdqc(struct packet_sock *po, 605 struct packet_ring_buffer *rb, 606 struct pgv *pg_vec, 607 union tpacket_req_u *req_u) 608 { 609 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 610 struct tpacket_block_desc *pbd; 611 612 memset(p1, 0x0, sizeof(*p1)); 613 614 p1->knxt_seq_num = 1; 615 p1->pkbdq = pg_vec; 616 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 617 p1->pkblk_start = pg_vec[0].buffer; 618 p1->kblk_size = req_u->req3.tp_block_size; 619 p1->knum_blocks = req_u->req3.tp_block_nr; 620 p1->hdrlen = po->tp_hdrlen; 621 p1->version = po->tp_version; 622 p1->last_kactive_blk_num = 0; 623 po->stats.stats3.tp_freeze_q_cnt = 0; 624 if (req_u->req3.tp_retire_blk_tov) 625 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 626 else 627 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 628 req_u->req3.tp_block_size); 629 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 630 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 631 632 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 633 prb_init_ft_ops(p1, req_u); 634 prb_setup_retire_blk_timer(po); 635 prb_open_block(p1, pbd); 636 } 637 638 /* Do NOT update the last_blk_num first. 639 * Assumes sk_buff_head lock is held. 640 */ 641 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 642 { 643 mod_timer(&pkc->retire_blk_timer, 644 jiffies + pkc->tov_in_jiffies); 645 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 646 } 647 648 /* 649 * Timer logic: 650 * 1) We refresh the timer only when we open a block. 651 * By doing this we don't waste cycles refreshing the timer 652 * on packet-by-packet basis. 653 * 654 * With a 1MB block-size, on a 1Gbps line, it will take 655 * i) ~8 ms to fill a block + ii) memcpy etc. 656 * In this cut we are not accounting for the memcpy time. 657 * 658 * So, if the user sets the 'tmo' to 10ms then the timer 659 * will never fire while the block is still getting filled 660 * (which is what we want). However, the user could choose 661 * to close a block early and that's fine. 662 * 663 * But when the timer does fire, we check whether or not to refresh it. 664 * Since the tmo granularity is in msecs, it is not too expensive 665 * to refresh the timer, lets say every '8' msecs. 666 * Either the user can set the 'tmo' or we can derive it based on 667 * a) line-speed and b) block-size. 668 * prb_calc_retire_blk_tmo() calculates the tmo. 669 * 670 */ 671 static void prb_retire_rx_blk_timer_expired(unsigned long data) 672 { 673 struct packet_sock *po = (struct packet_sock *)data; 674 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 675 unsigned int frozen; 676 struct tpacket_block_desc *pbd; 677 678 spin_lock(&po->sk.sk_receive_queue.lock); 679 680 frozen = prb_queue_frozen(pkc); 681 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 682 683 if (unlikely(pkc->delete_blk_timer)) 684 goto out; 685 686 /* We only need to plug the race when the block is partially filled. 687 * tpacket_rcv: 688 * lock(); increment BLOCK_NUM_PKTS; unlock() 689 * copy_bits() is in progress ... 690 * timer fires on other cpu: 691 * we can't retire the current block because copy_bits 692 * is in progress. 693 * 694 */ 695 if (BLOCK_NUM_PKTS(pbd)) { 696 while (atomic_read(&pkc->blk_fill_in_prog)) { 697 /* Waiting for skb_copy_bits to finish... */ 698 cpu_relax(); 699 } 700 } 701 702 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 703 if (!frozen) { 704 if (!BLOCK_NUM_PKTS(pbd)) { 705 /* An empty block. Just refresh the timer. */ 706 goto refresh_timer; 707 } 708 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 709 if (!prb_dispatch_next_block(pkc, po)) 710 goto refresh_timer; 711 else 712 goto out; 713 } else { 714 /* Case 1. Queue was frozen because user-space was 715 * lagging behind. 716 */ 717 if (prb_curr_blk_in_use(pkc, pbd)) { 718 /* 719 * Ok, user-space is still behind. 720 * So just refresh the timer. 721 */ 722 goto refresh_timer; 723 } else { 724 /* Case 2. queue was frozen,user-space caught up, 725 * now the link went idle && the timer fired. 726 * We don't have a block to close.So we open this 727 * block and restart the timer. 728 * opening a block thaws the queue,restarts timer 729 * Thawing/timer-refresh is a side effect. 730 */ 731 prb_open_block(pkc, pbd); 732 goto out; 733 } 734 } 735 } 736 737 refresh_timer: 738 _prb_refresh_rx_retire_blk_timer(pkc); 739 740 out: 741 spin_unlock(&po->sk.sk_receive_queue.lock); 742 } 743 744 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 745 struct tpacket_block_desc *pbd1, __u32 status) 746 { 747 /* Flush everything minus the block header */ 748 749 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 750 u8 *start, *end; 751 752 start = (u8 *)pbd1; 753 754 /* Skip the block header(we know header WILL fit in 4K) */ 755 start += PAGE_SIZE; 756 757 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 758 for (; start < end; start += PAGE_SIZE) 759 flush_dcache_page(pgv_to_page(start)); 760 761 smp_wmb(); 762 #endif 763 764 /* Now update the block status. */ 765 766 BLOCK_STATUS(pbd1) = status; 767 768 /* Flush the block header */ 769 770 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 771 start = (u8 *)pbd1; 772 flush_dcache_page(pgv_to_page(start)); 773 774 smp_wmb(); 775 #endif 776 } 777 778 /* 779 * Side effect: 780 * 781 * 1) flush the block 782 * 2) Increment active_blk_num 783 * 784 * Note:We DONT refresh the timer on purpose. 785 * Because almost always the next block will be opened. 786 */ 787 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 788 struct tpacket_block_desc *pbd1, 789 struct packet_sock *po, unsigned int stat) 790 { 791 __u32 status = TP_STATUS_USER | stat; 792 793 struct tpacket3_hdr *last_pkt; 794 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 795 struct sock *sk = &po->sk; 796 797 if (po->stats.stats3.tp_drops) 798 status |= TP_STATUS_LOSING; 799 800 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 801 last_pkt->tp_next_offset = 0; 802 803 /* Get the ts of the last pkt */ 804 if (BLOCK_NUM_PKTS(pbd1)) { 805 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 806 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 807 } else { 808 /* Ok, we tmo'd - so get the current time. 809 * 810 * It shouldn't really happen as we don't close empty 811 * blocks. See prb_retire_rx_blk_timer_expired(). 812 */ 813 struct timespec ts; 814 getnstimeofday(&ts); 815 h1->ts_last_pkt.ts_sec = ts.tv_sec; 816 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 817 } 818 819 smp_wmb(); 820 821 /* Flush the block */ 822 prb_flush_block(pkc1, pbd1, status); 823 824 sk->sk_data_ready(sk); 825 826 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 827 } 828 829 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 830 { 831 pkc->reset_pending_on_curr_blk = 0; 832 } 833 834 /* 835 * Side effect of opening a block: 836 * 837 * 1) prb_queue is thawed. 838 * 2) retire_blk_timer is refreshed. 839 * 840 */ 841 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 842 struct tpacket_block_desc *pbd1) 843 { 844 struct timespec ts; 845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 846 847 smp_rmb(); 848 849 /* We could have just memset this but we will lose the 850 * flexibility of making the priv area sticky 851 */ 852 853 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 854 BLOCK_NUM_PKTS(pbd1) = 0; 855 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 856 857 getnstimeofday(&ts); 858 859 h1->ts_first_pkt.ts_sec = ts.tv_sec; 860 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 861 862 pkc1->pkblk_start = (char *)pbd1; 863 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 864 865 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 866 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 867 868 pbd1->version = pkc1->version; 869 pkc1->prev = pkc1->nxt_offset; 870 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 871 872 prb_thaw_queue(pkc1); 873 _prb_refresh_rx_retire_blk_timer(pkc1); 874 875 smp_wmb(); 876 } 877 878 /* 879 * Queue freeze logic: 880 * 1) Assume tp_block_nr = 8 blocks. 881 * 2) At time 't0', user opens Rx ring. 882 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 883 * 4) user-space is either sleeping or processing block '0'. 884 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 885 * it will close block-7,loop around and try to fill block '0'. 886 * call-flow: 887 * __packet_lookup_frame_in_block 888 * prb_retire_current_block() 889 * prb_dispatch_next_block() 890 * |->(BLOCK_STATUS == USER) evaluates to true 891 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 892 * 6) Now there are two cases: 893 * 6.1) Link goes idle right after the queue is frozen. 894 * But remember, the last open_block() refreshed the timer. 895 * When this timer expires,it will refresh itself so that we can 896 * re-open block-0 in near future. 897 * 6.2) Link is busy and keeps on receiving packets. This is a simple 898 * case and __packet_lookup_frame_in_block will check if block-0 899 * is free and can now be re-used. 900 */ 901 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 902 struct packet_sock *po) 903 { 904 pkc->reset_pending_on_curr_blk = 1; 905 po->stats.stats3.tp_freeze_q_cnt++; 906 } 907 908 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 909 910 /* 911 * If the next block is free then we will dispatch it 912 * and return a good offset. 913 * Else, we will freeze the queue. 914 * So, caller must check the return value. 915 */ 916 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 917 struct packet_sock *po) 918 { 919 struct tpacket_block_desc *pbd; 920 921 smp_rmb(); 922 923 /* 1. Get current block num */ 924 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 925 926 /* 2. If this block is currently in_use then freeze the queue */ 927 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 928 prb_freeze_queue(pkc, po); 929 return NULL; 930 } 931 932 /* 933 * 3. 934 * open this block and return the offset where the first packet 935 * needs to get stored. 936 */ 937 prb_open_block(pkc, pbd); 938 return (void *)pkc->nxt_offset; 939 } 940 941 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 942 struct packet_sock *po, unsigned int status) 943 { 944 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 945 946 /* retire/close the current block */ 947 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 948 /* 949 * Plug the case where copy_bits() is in progress on 950 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 951 * have space to copy the pkt in the current block and 952 * called prb_retire_current_block() 953 * 954 * We don't need to worry about the TMO case because 955 * the timer-handler already handled this case. 956 */ 957 if (!(status & TP_STATUS_BLK_TMO)) { 958 while (atomic_read(&pkc->blk_fill_in_prog)) { 959 /* Waiting for skb_copy_bits to finish... */ 960 cpu_relax(); 961 } 962 } 963 prb_close_block(pkc, pbd, po, status); 964 return; 965 } 966 } 967 968 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 969 struct tpacket_block_desc *pbd) 970 { 971 return TP_STATUS_USER & BLOCK_STATUS(pbd); 972 } 973 974 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 975 { 976 return pkc->reset_pending_on_curr_blk; 977 } 978 979 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 980 { 981 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 982 atomic_dec(&pkc->blk_fill_in_prog); 983 } 984 985 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 986 struct tpacket3_hdr *ppd) 987 { 988 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 989 } 990 991 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 992 struct tpacket3_hdr *ppd) 993 { 994 ppd->hv1.tp_rxhash = 0; 995 } 996 997 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 998 struct tpacket3_hdr *ppd) 999 { 1000 if (skb_vlan_tag_present(pkc->skb)) { 1001 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1002 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1003 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1004 } else { 1005 ppd->hv1.tp_vlan_tci = 0; 1006 ppd->hv1.tp_vlan_tpid = 0; 1007 ppd->tp_status = TP_STATUS_AVAILABLE; 1008 } 1009 } 1010 1011 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1012 struct tpacket3_hdr *ppd) 1013 { 1014 ppd->hv1.tp_padding = 0; 1015 prb_fill_vlan_info(pkc, ppd); 1016 1017 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1018 prb_fill_rxhash(pkc, ppd); 1019 else 1020 prb_clear_rxhash(pkc, ppd); 1021 } 1022 1023 static void prb_fill_curr_block(char *curr, 1024 struct tpacket_kbdq_core *pkc, 1025 struct tpacket_block_desc *pbd, 1026 unsigned int len) 1027 { 1028 struct tpacket3_hdr *ppd; 1029 1030 ppd = (struct tpacket3_hdr *)curr; 1031 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1032 pkc->prev = curr; 1033 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1034 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1035 BLOCK_NUM_PKTS(pbd) += 1; 1036 atomic_inc(&pkc->blk_fill_in_prog); 1037 prb_run_all_ft_ops(pkc, ppd); 1038 } 1039 1040 /* Assumes caller has the sk->rx_queue.lock */ 1041 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1042 struct sk_buff *skb, 1043 int status, 1044 unsigned int len 1045 ) 1046 { 1047 struct tpacket_kbdq_core *pkc; 1048 struct tpacket_block_desc *pbd; 1049 char *curr, *end; 1050 1051 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1052 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1053 1054 /* Queue is frozen when user space is lagging behind */ 1055 if (prb_queue_frozen(pkc)) { 1056 /* 1057 * Check if that last block which caused the queue to freeze, 1058 * is still in_use by user-space. 1059 */ 1060 if (prb_curr_blk_in_use(pkc, pbd)) { 1061 /* Can't record this packet */ 1062 return NULL; 1063 } else { 1064 /* 1065 * Ok, the block was released by user-space. 1066 * Now let's open that block. 1067 * opening a block also thaws the queue. 1068 * Thawing is a side effect. 1069 */ 1070 prb_open_block(pkc, pbd); 1071 } 1072 } 1073 1074 smp_mb(); 1075 curr = pkc->nxt_offset; 1076 pkc->skb = skb; 1077 end = (char *)pbd + pkc->kblk_size; 1078 1079 /* first try the current block */ 1080 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1081 prb_fill_curr_block(curr, pkc, pbd, len); 1082 return (void *)curr; 1083 } 1084 1085 /* Ok, close the current block */ 1086 prb_retire_current_block(pkc, po, 0); 1087 1088 /* Now, try to dispatch the next block */ 1089 curr = (char *)prb_dispatch_next_block(pkc, po); 1090 if (curr) { 1091 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1092 prb_fill_curr_block(curr, pkc, pbd, len); 1093 return (void *)curr; 1094 } 1095 1096 /* 1097 * No free blocks are available.user_space hasn't caught up yet. 1098 * Queue was just frozen and now this packet will get dropped. 1099 */ 1100 return NULL; 1101 } 1102 1103 static void *packet_current_rx_frame(struct packet_sock *po, 1104 struct sk_buff *skb, 1105 int status, unsigned int len) 1106 { 1107 char *curr = NULL; 1108 switch (po->tp_version) { 1109 case TPACKET_V1: 1110 case TPACKET_V2: 1111 curr = packet_lookup_frame(po, &po->rx_ring, 1112 po->rx_ring.head, status); 1113 return curr; 1114 case TPACKET_V3: 1115 return __packet_lookup_frame_in_block(po, skb, status, len); 1116 default: 1117 WARN(1, "TPACKET version not supported\n"); 1118 BUG(); 1119 return NULL; 1120 } 1121 } 1122 1123 static void *prb_lookup_block(struct packet_sock *po, 1124 struct packet_ring_buffer *rb, 1125 unsigned int idx, 1126 int status) 1127 { 1128 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1129 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1130 1131 if (status != BLOCK_STATUS(pbd)) 1132 return NULL; 1133 return pbd; 1134 } 1135 1136 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1137 { 1138 unsigned int prev; 1139 if (rb->prb_bdqc.kactive_blk_num) 1140 prev = rb->prb_bdqc.kactive_blk_num-1; 1141 else 1142 prev = rb->prb_bdqc.knum_blocks-1; 1143 return prev; 1144 } 1145 1146 /* Assumes caller has held the rx_queue.lock */ 1147 static void *__prb_previous_block(struct packet_sock *po, 1148 struct packet_ring_buffer *rb, 1149 int status) 1150 { 1151 unsigned int previous = prb_previous_blk_num(rb); 1152 return prb_lookup_block(po, rb, previous, status); 1153 } 1154 1155 static void *packet_previous_rx_frame(struct packet_sock *po, 1156 struct packet_ring_buffer *rb, 1157 int status) 1158 { 1159 if (po->tp_version <= TPACKET_V2) 1160 return packet_previous_frame(po, rb, status); 1161 1162 return __prb_previous_block(po, rb, status); 1163 } 1164 1165 static void packet_increment_rx_head(struct packet_sock *po, 1166 struct packet_ring_buffer *rb) 1167 { 1168 switch (po->tp_version) { 1169 case TPACKET_V1: 1170 case TPACKET_V2: 1171 return packet_increment_head(rb); 1172 case TPACKET_V3: 1173 default: 1174 WARN(1, "TPACKET version not supported.\n"); 1175 BUG(); 1176 return; 1177 } 1178 } 1179 1180 static void *packet_previous_frame(struct packet_sock *po, 1181 struct packet_ring_buffer *rb, 1182 int status) 1183 { 1184 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1185 return packet_lookup_frame(po, rb, previous, status); 1186 } 1187 1188 static void packet_increment_head(struct packet_ring_buffer *buff) 1189 { 1190 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1191 } 1192 1193 static void packet_inc_pending(struct packet_ring_buffer *rb) 1194 { 1195 this_cpu_inc(*rb->pending_refcnt); 1196 } 1197 1198 static void packet_dec_pending(struct packet_ring_buffer *rb) 1199 { 1200 this_cpu_dec(*rb->pending_refcnt); 1201 } 1202 1203 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1204 { 1205 unsigned int refcnt = 0; 1206 int cpu; 1207 1208 /* We don't use pending refcount in rx_ring. */ 1209 if (rb->pending_refcnt == NULL) 1210 return 0; 1211 1212 for_each_possible_cpu(cpu) 1213 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1214 1215 return refcnt; 1216 } 1217 1218 static int packet_alloc_pending(struct packet_sock *po) 1219 { 1220 po->rx_ring.pending_refcnt = NULL; 1221 1222 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1223 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1224 return -ENOBUFS; 1225 1226 return 0; 1227 } 1228 1229 static void packet_free_pending(struct packet_sock *po) 1230 { 1231 free_percpu(po->tx_ring.pending_refcnt); 1232 } 1233 1234 #define ROOM_POW_OFF 2 1235 #define ROOM_NONE 0x0 1236 #define ROOM_LOW 0x1 1237 #define ROOM_NORMAL 0x2 1238 1239 static bool __tpacket_has_room(struct packet_sock *po, int pow_off) 1240 { 1241 int idx, len; 1242 1243 len = po->rx_ring.frame_max + 1; 1244 idx = po->rx_ring.head; 1245 if (pow_off) 1246 idx += len >> pow_off; 1247 if (idx >= len) 1248 idx -= len; 1249 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1250 } 1251 1252 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off) 1253 { 1254 int idx, len; 1255 1256 len = po->rx_ring.prb_bdqc.knum_blocks; 1257 idx = po->rx_ring.prb_bdqc.kactive_blk_num; 1258 if (pow_off) 1259 idx += len >> pow_off; 1260 if (idx >= len) 1261 idx -= len; 1262 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1263 } 1264 1265 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1266 { 1267 struct sock *sk = &po->sk; 1268 int ret = ROOM_NONE; 1269 1270 if (po->prot_hook.func != tpacket_rcv) { 1271 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1272 - (skb ? skb->truesize : 0); 1273 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF)) 1274 return ROOM_NORMAL; 1275 else if (avail > 0) 1276 return ROOM_LOW; 1277 else 1278 return ROOM_NONE; 1279 } 1280 1281 if (po->tp_version == TPACKET_V3) { 1282 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1283 ret = ROOM_NORMAL; 1284 else if (__tpacket_v3_has_room(po, 0)) 1285 ret = ROOM_LOW; 1286 } else { 1287 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1288 ret = ROOM_NORMAL; 1289 else if (__tpacket_has_room(po, 0)) 1290 ret = ROOM_LOW; 1291 } 1292 1293 return ret; 1294 } 1295 1296 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1297 { 1298 int ret; 1299 bool has_room; 1300 1301 spin_lock_bh(&po->sk.sk_receive_queue.lock); 1302 ret = __packet_rcv_has_room(po, skb); 1303 has_room = ret == ROOM_NORMAL; 1304 if (po->pressure == has_room) 1305 po->pressure = !has_room; 1306 spin_unlock_bh(&po->sk.sk_receive_queue.lock); 1307 1308 return ret; 1309 } 1310 1311 static void packet_sock_destruct(struct sock *sk) 1312 { 1313 skb_queue_purge(&sk->sk_error_queue); 1314 1315 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1316 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1317 1318 if (!sock_flag(sk, SOCK_DEAD)) { 1319 pr_err("Attempt to release alive packet socket: %p\n", sk); 1320 return; 1321 } 1322 1323 sk_refcnt_debug_dec(sk); 1324 } 1325 1326 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1327 { 1328 u32 rxhash; 1329 int i, count = 0; 1330 1331 rxhash = skb_get_hash(skb); 1332 for (i = 0; i < ROLLOVER_HLEN; i++) 1333 if (po->rollover->history[i] == rxhash) 1334 count++; 1335 1336 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash; 1337 return count > (ROLLOVER_HLEN >> 1); 1338 } 1339 1340 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1341 struct sk_buff *skb, 1342 unsigned int num) 1343 { 1344 return reciprocal_scale(skb_get_hash(skb), num); 1345 } 1346 1347 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1348 struct sk_buff *skb, 1349 unsigned int num) 1350 { 1351 unsigned int val = atomic_inc_return(&f->rr_cur); 1352 1353 return val % num; 1354 } 1355 1356 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1357 struct sk_buff *skb, 1358 unsigned int num) 1359 { 1360 return smp_processor_id() % num; 1361 } 1362 1363 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1364 struct sk_buff *skb, 1365 unsigned int num) 1366 { 1367 return prandom_u32_max(num); 1368 } 1369 1370 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1371 struct sk_buff *skb, 1372 unsigned int idx, bool try_self, 1373 unsigned int num) 1374 { 1375 struct packet_sock *po, *po_next, *po_skip = NULL; 1376 unsigned int i, j, room = ROOM_NONE; 1377 1378 po = pkt_sk(f->arr[idx]); 1379 1380 if (try_self) { 1381 room = packet_rcv_has_room(po, skb); 1382 if (room == ROOM_NORMAL || 1383 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1384 return idx; 1385 po_skip = po; 1386 } 1387 1388 i = j = min_t(int, po->rollover->sock, num - 1); 1389 do { 1390 po_next = pkt_sk(f->arr[i]); 1391 if (po_next != po_skip && !po_next->pressure && 1392 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1393 if (i != j) 1394 po->rollover->sock = i; 1395 atomic_long_inc(&po->rollover->num); 1396 if (room == ROOM_LOW) 1397 atomic_long_inc(&po->rollover->num_huge); 1398 return i; 1399 } 1400 1401 if (++i == num) 1402 i = 0; 1403 } while (i != j); 1404 1405 atomic_long_inc(&po->rollover->num_failed); 1406 return idx; 1407 } 1408 1409 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1410 struct sk_buff *skb, 1411 unsigned int num) 1412 { 1413 return skb_get_queue_mapping(skb) % num; 1414 } 1415 1416 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1417 struct sk_buff *skb, 1418 unsigned int num) 1419 { 1420 struct bpf_prog *prog; 1421 unsigned int ret = 0; 1422 1423 rcu_read_lock(); 1424 prog = rcu_dereference(f->bpf_prog); 1425 if (prog) 1426 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1427 rcu_read_unlock(); 1428 1429 return ret; 1430 } 1431 1432 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1433 { 1434 return f->flags & (flag >> 8); 1435 } 1436 1437 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1438 struct packet_type *pt, struct net_device *orig_dev) 1439 { 1440 struct packet_fanout *f = pt->af_packet_priv; 1441 unsigned int num = READ_ONCE(f->num_members); 1442 struct net *net = read_pnet(&f->net); 1443 struct packet_sock *po; 1444 unsigned int idx; 1445 1446 if (!net_eq(dev_net(dev), net) || !num) { 1447 kfree_skb(skb); 1448 return 0; 1449 } 1450 1451 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1452 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1453 if (!skb) 1454 return 0; 1455 } 1456 switch (f->type) { 1457 case PACKET_FANOUT_HASH: 1458 default: 1459 idx = fanout_demux_hash(f, skb, num); 1460 break; 1461 case PACKET_FANOUT_LB: 1462 idx = fanout_demux_lb(f, skb, num); 1463 break; 1464 case PACKET_FANOUT_CPU: 1465 idx = fanout_demux_cpu(f, skb, num); 1466 break; 1467 case PACKET_FANOUT_RND: 1468 idx = fanout_demux_rnd(f, skb, num); 1469 break; 1470 case PACKET_FANOUT_QM: 1471 idx = fanout_demux_qm(f, skb, num); 1472 break; 1473 case PACKET_FANOUT_ROLLOVER: 1474 idx = fanout_demux_rollover(f, skb, 0, false, num); 1475 break; 1476 case PACKET_FANOUT_CBPF: 1477 case PACKET_FANOUT_EBPF: 1478 idx = fanout_demux_bpf(f, skb, num); 1479 break; 1480 } 1481 1482 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1483 idx = fanout_demux_rollover(f, skb, idx, true, num); 1484 1485 po = pkt_sk(f->arr[idx]); 1486 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1487 } 1488 1489 DEFINE_MUTEX(fanout_mutex); 1490 EXPORT_SYMBOL_GPL(fanout_mutex); 1491 static LIST_HEAD(fanout_list); 1492 1493 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1494 { 1495 struct packet_fanout *f = po->fanout; 1496 1497 spin_lock(&f->lock); 1498 f->arr[f->num_members] = sk; 1499 smp_wmb(); 1500 f->num_members++; 1501 spin_unlock(&f->lock); 1502 } 1503 1504 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1505 { 1506 struct packet_fanout *f = po->fanout; 1507 int i; 1508 1509 spin_lock(&f->lock); 1510 for (i = 0; i < f->num_members; i++) { 1511 if (f->arr[i] == sk) 1512 break; 1513 } 1514 BUG_ON(i >= f->num_members); 1515 f->arr[i] = f->arr[f->num_members - 1]; 1516 f->num_members--; 1517 spin_unlock(&f->lock); 1518 } 1519 1520 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1521 { 1522 if (sk->sk_family != PF_PACKET) 1523 return false; 1524 1525 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1526 } 1527 1528 static void fanout_init_data(struct packet_fanout *f) 1529 { 1530 switch (f->type) { 1531 case PACKET_FANOUT_LB: 1532 atomic_set(&f->rr_cur, 0); 1533 break; 1534 case PACKET_FANOUT_CBPF: 1535 case PACKET_FANOUT_EBPF: 1536 RCU_INIT_POINTER(f->bpf_prog, NULL); 1537 break; 1538 } 1539 } 1540 1541 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1542 { 1543 struct bpf_prog *old; 1544 1545 spin_lock(&f->lock); 1546 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1547 rcu_assign_pointer(f->bpf_prog, new); 1548 spin_unlock(&f->lock); 1549 1550 if (old) { 1551 synchronize_net(); 1552 bpf_prog_destroy(old); 1553 } 1554 } 1555 1556 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data, 1557 unsigned int len) 1558 { 1559 struct bpf_prog *new; 1560 struct sock_fprog fprog; 1561 int ret; 1562 1563 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1564 return -EPERM; 1565 if (len != sizeof(fprog)) 1566 return -EINVAL; 1567 if (copy_from_user(&fprog, data, len)) 1568 return -EFAULT; 1569 1570 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1571 if (ret) 1572 return ret; 1573 1574 __fanout_set_data_bpf(po->fanout, new); 1575 return 0; 1576 } 1577 1578 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data, 1579 unsigned int len) 1580 { 1581 struct bpf_prog *new; 1582 u32 fd; 1583 1584 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1585 return -EPERM; 1586 if (len != sizeof(fd)) 1587 return -EINVAL; 1588 if (copy_from_user(&fd, data, len)) 1589 return -EFAULT; 1590 1591 new = bpf_prog_get(fd); 1592 if (IS_ERR(new)) 1593 return PTR_ERR(new); 1594 if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) { 1595 bpf_prog_put(new); 1596 return -EINVAL; 1597 } 1598 1599 __fanout_set_data_bpf(po->fanout, new); 1600 return 0; 1601 } 1602 1603 static int fanout_set_data(struct packet_sock *po, char __user *data, 1604 unsigned int len) 1605 { 1606 switch (po->fanout->type) { 1607 case PACKET_FANOUT_CBPF: 1608 return fanout_set_data_cbpf(po, data, len); 1609 case PACKET_FANOUT_EBPF: 1610 return fanout_set_data_ebpf(po, data, len); 1611 default: 1612 return -EINVAL; 1613 }; 1614 } 1615 1616 static void fanout_release_data(struct packet_fanout *f) 1617 { 1618 switch (f->type) { 1619 case PACKET_FANOUT_CBPF: 1620 case PACKET_FANOUT_EBPF: 1621 __fanout_set_data_bpf(f, NULL); 1622 }; 1623 } 1624 1625 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1626 { 1627 struct packet_sock *po = pkt_sk(sk); 1628 struct packet_fanout *f, *match; 1629 u8 type = type_flags & 0xff; 1630 u8 flags = type_flags >> 8; 1631 int err; 1632 1633 switch (type) { 1634 case PACKET_FANOUT_ROLLOVER: 1635 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1636 return -EINVAL; 1637 case PACKET_FANOUT_HASH: 1638 case PACKET_FANOUT_LB: 1639 case PACKET_FANOUT_CPU: 1640 case PACKET_FANOUT_RND: 1641 case PACKET_FANOUT_QM: 1642 case PACKET_FANOUT_CBPF: 1643 case PACKET_FANOUT_EBPF: 1644 break; 1645 default: 1646 return -EINVAL; 1647 } 1648 1649 if (!po->running) 1650 return -EINVAL; 1651 1652 if (po->fanout) 1653 return -EALREADY; 1654 1655 if (type == PACKET_FANOUT_ROLLOVER || 1656 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1657 po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL); 1658 if (!po->rollover) 1659 return -ENOMEM; 1660 atomic_long_set(&po->rollover->num, 0); 1661 atomic_long_set(&po->rollover->num_huge, 0); 1662 atomic_long_set(&po->rollover->num_failed, 0); 1663 } 1664 1665 mutex_lock(&fanout_mutex); 1666 match = NULL; 1667 list_for_each_entry(f, &fanout_list, list) { 1668 if (f->id == id && 1669 read_pnet(&f->net) == sock_net(sk)) { 1670 match = f; 1671 break; 1672 } 1673 } 1674 err = -EINVAL; 1675 if (match && match->flags != flags) 1676 goto out; 1677 if (!match) { 1678 err = -ENOMEM; 1679 match = kzalloc(sizeof(*match), GFP_KERNEL); 1680 if (!match) 1681 goto out; 1682 write_pnet(&match->net, sock_net(sk)); 1683 match->id = id; 1684 match->type = type; 1685 match->flags = flags; 1686 INIT_LIST_HEAD(&match->list); 1687 spin_lock_init(&match->lock); 1688 atomic_set(&match->sk_ref, 0); 1689 fanout_init_data(match); 1690 match->prot_hook.type = po->prot_hook.type; 1691 match->prot_hook.dev = po->prot_hook.dev; 1692 match->prot_hook.func = packet_rcv_fanout; 1693 match->prot_hook.af_packet_priv = match; 1694 match->prot_hook.id_match = match_fanout_group; 1695 dev_add_pack(&match->prot_hook); 1696 list_add(&match->list, &fanout_list); 1697 } 1698 err = -EINVAL; 1699 if (match->type == type && 1700 match->prot_hook.type == po->prot_hook.type && 1701 match->prot_hook.dev == po->prot_hook.dev) { 1702 err = -ENOSPC; 1703 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1704 __dev_remove_pack(&po->prot_hook); 1705 po->fanout = match; 1706 atomic_inc(&match->sk_ref); 1707 __fanout_link(sk, po); 1708 err = 0; 1709 } 1710 } 1711 out: 1712 mutex_unlock(&fanout_mutex); 1713 if (err) { 1714 kfree(po->rollover); 1715 po->rollover = NULL; 1716 } 1717 return err; 1718 } 1719 1720 static void fanout_release(struct sock *sk) 1721 { 1722 struct packet_sock *po = pkt_sk(sk); 1723 struct packet_fanout *f; 1724 1725 f = po->fanout; 1726 if (!f) 1727 return; 1728 1729 mutex_lock(&fanout_mutex); 1730 po->fanout = NULL; 1731 1732 if (atomic_dec_and_test(&f->sk_ref)) { 1733 list_del(&f->list); 1734 dev_remove_pack(&f->prot_hook); 1735 fanout_release_data(f); 1736 kfree(f); 1737 } 1738 mutex_unlock(&fanout_mutex); 1739 1740 if (po->rollover) 1741 kfree_rcu(po->rollover, rcu); 1742 } 1743 1744 static 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(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 = bpf_prog_run_clear_cb(filter->prog, 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 sockcm_cookie sockc; 2634 struct virtio_net_hdr vnet_hdr = { 0 }; 2635 int offset = 0; 2636 int vnet_hdr_len; 2637 struct packet_sock *po = pkt_sk(sk); 2638 unsigned short gso_type = 0; 2639 int hlen, tlen; 2640 int extra_len = 0; 2641 ssize_t n; 2642 2643 /* 2644 * Get and verify the address. 2645 */ 2646 2647 if (likely(saddr == NULL)) { 2648 dev = packet_cached_dev_get(po); 2649 proto = po->num; 2650 addr = NULL; 2651 } else { 2652 err = -EINVAL; 2653 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2654 goto out; 2655 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2656 goto out; 2657 proto = saddr->sll_protocol; 2658 addr = saddr->sll_addr; 2659 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2660 } 2661 2662 err = -ENXIO; 2663 if (unlikely(dev == NULL)) 2664 goto out_unlock; 2665 err = -ENETDOWN; 2666 if (unlikely(!(dev->flags & IFF_UP))) 2667 goto out_unlock; 2668 2669 sockc.mark = sk->sk_mark; 2670 if (msg->msg_controllen) { 2671 err = sock_cmsg_send(sk, msg, &sockc); 2672 if (unlikely(err)) 2673 goto out_unlock; 2674 } 2675 2676 if (sock->type == SOCK_RAW) 2677 reserve = dev->hard_header_len; 2678 if (po->has_vnet_hdr) { 2679 vnet_hdr_len = sizeof(vnet_hdr); 2680 2681 err = -EINVAL; 2682 if (len < vnet_hdr_len) 2683 goto out_unlock; 2684 2685 len -= vnet_hdr_len; 2686 2687 err = -EFAULT; 2688 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter); 2689 if (n != vnet_hdr_len) 2690 goto out_unlock; 2691 2692 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2693 (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + 2694 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 > 2695 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len))) 2696 vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(), 2697 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + 2698 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2); 2699 2700 err = -EINVAL; 2701 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len) 2702 goto out_unlock; 2703 2704 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 2705 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 2706 case VIRTIO_NET_HDR_GSO_TCPV4: 2707 gso_type = SKB_GSO_TCPV4; 2708 break; 2709 case VIRTIO_NET_HDR_GSO_TCPV6: 2710 gso_type = SKB_GSO_TCPV6; 2711 break; 2712 case VIRTIO_NET_HDR_GSO_UDP: 2713 gso_type = SKB_GSO_UDP; 2714 break; 2715 default: 2716 goto out_unlock; 2717 } 2718 2719 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 2720 gso_type |= SKB_GSO_TCP_ECN; 2721 2722 if (vnet_hdr.gso_size == 0) 2723 goto out_unlock; 2724 2725 } 2726 } 2727 2728 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2729 if (!netif_supports_nofcs(dev)) { 2730 err = -EPROTONOSUPPORT; 2731 goto out_unlock; 2732 } 2733 extra_len = 4; /* We're doing our own CRC */ 2734 } 2735 2736 err = -EMSGSIZE; 2737 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2738 goto out_unlock; 2739 2740 err = -ENOBUFS; 2741 hlen = LL_RESERVED_SPACE(dev); 2742 tlen = dev->needed_tailroom; 2743 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, 2744 __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len), 2745 msg->msg_flags & MSG_DONTWAIT, &err); 2746 if (skb == NULL) 2747 goto out_unlock; 2748 2749 skb_set_network_header(skb, reserve); 2750 2751 err = -EINVAL; 2752 if (sock->type == SOCK_DGRAM) { 2753 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2754 if (unlikely(offset < 0)) 2755 goto out_free; 2756 } else { 2757 if (ll_header_truncated(dev, len)) 2758 goto out_free; 2759 } 2760 2761 /* Returns -EFAULT on error */ 2762 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2763 if (err) 2764 goto out_free; 2765 2766 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 2767 2768 if (!gso_type && (len > dev->mtu + reserve + extra_len)) { 2769 /* Earlier code assumed this would be a VLAN pkt, 2770 * double-check this now that we have the actual 2771 * packet in hand. 2772 */ 2773 struct ethhdr *ehdr; 2774 skb_reset_mac_header(skb); 2775 ehdr = eth_hdr(skb); 2776 if (ehdr->h_proto != htons(ETH_P_8021Q)) { 2777 err = -EMSGSIZE; 2778 goto out_free; 2779 } 2780 } 2781 2782 skb->protocol = proto; 2783 skb->dev = dev; 2784 skb->priority = sk->sk_priority; 2785 skb->mark = sockc.mark; 2786 2787 packet_pick_tx_queue(dev, skb); 2788 2789 if (po->has_vnet_hdr) { 2790 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 2791 u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start); 2792 u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset); 2793 if (!skb_partial_csum_set(skb, s, o)) { 2794 err = -EINVAL; 2795 goto out_free; 2796 } 2797 } 2798 2799 skb_shinfo(skb)->gso_size = 2800 __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size); 2801 skb_shinfo(skb)->gso_type = gso_type; 2802 2803 /* Header must be checked, and gso_segs computed. */ 2804 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 2805 skb_shinfo(skb)->gso_segs = 0; 2806 2807 len += vnet_hdr_len; 2808 } 2809 2810 if (!packet_use_direct_xmit(po)) 2811 skb_probe_transport_header(skb, reserve); 2812 if (unlikely(extra_len == 4)) 2813 skb->no_fcs = 1; 2814 2815 err = po->xmit(skb); 2816 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2817 goto out_unlock; 2818 2819 dev_put(dev); 2820 2821 return len; 2822 2823 out_free: 2824 kfree_skb(skb); 2825 out_unlock: 2826 if (dev) 2827 dev_put(dev); 2828 out: 2829 return err; 2830 } 2831 2832 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 2833 { 2834 struct sock *sk = sock->sk; 2835 struct packet_sock *po = pkt_sk(sk); 2836 2837 if (po->tx_ring.pg_vec) 2838 return tpacket_snd(po, msg); 2839 else 2840 return packet_snd(sock, msg, len); 2841 } 2842 2843 /* 2844 * Close a PACKET socket. This is fairly simple. We immediately go 2845 * to 'closed' state and remove our protocol entry in the device list. 2846 */ 2847 2848 static int packet_release(struct socket *sock) 2849 { 2850 struct sock *sk = sock->sk; 2851 struct packet_sock *po; 2852 struct net *net; 2853 union tpacket_req_u req_u; 2854 2855 if (!sk) 2856 return 0; 2857 2858 net = sock_net(sk); 2859 po = pkt_sk(sk); 2860 2861 mutex_lock(&net->packet.sklist_lock); 2862 sk_del_node_init_rcu(sk); 2863 mutex_unlock(&net->packet.sklist_lock); 2864 2865 preempt_disable(); 2866 sock_prot_inuse_add(net, sk->sk_prot, -1); 2867 preempt_enable(); 2868 2869 spin_lock(&po->bind_lock); 2870 unregister_prot_hook(sk, false); 2871 packet_cached_dev_reset(po); 2872 2873 if (po->prot_hook.dev) { 2874 dev_put(po->prot_hook.dev); 2875 po->prot_hook.dev = NULL; 2876 } 2877 spin_unlock(&po->bind_lock); 2878 2879 packet_flush_mclist(sk); 2880 2881 if (po->rx_ring.pg_vec) { 2882 memset(&req_u, 0, sizeof(req_u)); 2883 packet_set_ring(sk, &req_u, 1, 0); 2884 } 2885 2886 if (po->tx_ring.pg_vec) { 2887 memset(&req_u, 0, sizeof(req_u)); 2888 packet_set_ring(sk, &req_u, 1, 1); 2889 } 2890 2891 fanout_release(sk); 2892 2893 synchronize_net(); 2894 /* 2895 * Now the socket is dead. No more input will appear. 2896 */ 2897 sock_orphan(sk); 2898 sock->sk = NULL; 2899 2900 /* Purge queues */ 2901 2902 skb_queue_purge(&sk->sk_receive_queue); 2903 packet_free_pending(po); 2904 sk_refcnt_debug_release(sk); 2905 2906 sock_put(sk); 2907 return 0; 2908 } 2909 2910 /* 2911 * Attach a packet hook. 2912 */ 2913 2914 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 2915 __be16 proto) 2916 { 2917 struct packet_sock *po = pkt_sk(sk); 2918 struct net_device *dev_curr; 2919 __be16 proto_curr; 2920 bool need_rehook; 2921 struct net_device *dev = NULL; 2922 int ret = 0; 2923 bool unlisted = false; 2924 2925 if (po->fanout) 2926 return -EINVAL; 2927 2928 lock_sock(sk); 2929 spin_lock(&po->bind_lock); 2930 rcu_read_lock(); 2931 2932 if (name) { 2933 dev = dev_get_by_name_rcu(sock_net(sk), name); 2934 if (!dev) { 2935 ret = -ENODEV; 2936 goto out_unlock; 2937 } 2938 } else if (ifindex) { 2939 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 2940 if (!dev) { 2941 ret = -ENODEV; 2942 goto out_unlock; 2943 } 2944 } 2945 2946 if (dev) 2947 dev_hold(dev); 2948 2949 proto_curr = po->prot_hook.type; 2950 dev_curr = po->prot_hook.dev; 2951 2952 need_rehook = proto_curr != proto || dev_curr != dev; 2953 2954 if (need_rehook) { 2955 if (po->running) { 2956 rcu_read_unlock(); 2957 __unregister_prot_hook(sk, true); 2958 rcu_read_lock(); 2959 dev_curr = po->prot_hook.dev; 2960 if (dev) 2961 unlisted = !dev_get_by_index_rcu(sock_net(sk), 2962 dev->ifindex); 2963 } 2964 2965 po->num = proto; 2966 po->prot_hook.type = proto; 2967 2968 if (unlikely(unlisted)) { 2969 dev_put(dev); 2970 po->prot_hook.dev = NULL; 2971 po->ifindex = -1; 2972 packet_cached_dev_reset(po); 2973 } else { 2974 po->prot_hook.dev = dev; 2975 po->ifindex = dev ? dev->ifindex : 0; 2976 packet_cached_dev_assign(po, dev); 2977 } 2978 } 2979 if (dev_curr) 2980 dev_put(dev_curr); 2981 2982 if (proto == 0 || !need_rehook) 2983 goto out_unlock; 2984 2985 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 2986 register_prot_hook(sk); 2987 } else { 2988 sk->sk_err = ENETDOWN; 2989 if (!sock_flag(sk, SOCK_DEAD)) 2990 sk->sk_error_report(sk); 2991 } 2992 2993 out_unlock: 2994 rcu_read_unlock(); 2995 spin_unlock(&po->bind_lock); 2996 release_sock(sk); 2997 return ret; 2998 } 2999 3000 /* 3001 * Bind a packet socket to a device 3002 */ 3003 3004 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3005 int addr_len) 3006 { 3007 struct sock *sk = sock->sk; 3008 char name[15]; 3009 3010 /* 3011 * Check legality 3012 */ 3013 3014 if (addr_len != sizeof(struct sockaddr)) 3015 return -EINVAL; 3016 strlcpy(name, uaddr->sa_data, sizeof(name)); 3017 3018 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); 3019 } 3020 3021 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3022 { 3023 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3024 struct sock *sk = sock->sk; 3025 3026 /* 3027 * Check legality 3028 */ 3029 3030 if (addr_len < sizeof(struct sockaddr_ll)) 3031 return -EINVAL; 3032 if (sll->sll_family != AF_PACKET) 3033 return -EINVAL; 3034 3035 return packet_do_bind(sk, NULL, sll->sll_ifindex, 3036 sll->sll_protocol ? : pkt_sk(sk)->num); 3037 } 3038 3039 static struct proto packet_proto = { 3040 .name = "PACKET", 3041 .owner = THIS_MODULE, 3042 .obj_size = sizeof(struct packet_sock), 3043 }; 3044 3045 /* 3046 * Create a packet of type SOCK_PACKET. 3047 */ 3048 3049 static int packet_create(struct net *net, struct socket *sock, int protocol, 3050 int kern) 3051 { 3052 struct sock *sk; 3053 struct packet_sock *po; 3054 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3055 int err; 3056 3057 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3058 return -EPERM; 3059 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3060 sock->type != SOCK_PACKET) 3061 return -ESOCKTNOSUPPORT; 3062 3063 sock->state = SS_UNCONNECTED; 3064 3065 err = -ENOBUFS; 3066 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3067 if (sk == NULL) 3068 goto out; 3069 3070 sock->ops = &packet_ops; 3071 if (sock->type == SOCK_PACKET) 3072 sock->ops = &packet_ops_spkt; 3073 3074 sock_init_data(sock, sk); 3075 3076 po = pkt_sk(sk); 3077 sk->sk_family = PF_PACKET; 3078 po->num = proto; 3079 po->xmit = dev_queue_xmit; 3080 3081 err = packet_alloc_pending(po); 3082 if (err) 3083 goto out2; 3084 3085 packet_cached_dev_reset(po); 3086 3087 sk->sk_destruct = packet_sock_destruct; 3088 sk_refcnt_debug_inc(sk); 3089 3090 /* 3091 * Attach a protocol block 3092 */ 3093 3094 spin_lock_init(&po->bind_lock); 3095 mutex_init(&po->pg_vec_lock); 3096 po->rollover = NULL; 3097 po->prot_hook.func = packet_rcv; 3098 3099 if (sock->type == SOCK_PACKET) 3100 po->prot_hook.func = packet_rcv_spkt; 3101 3102 po->prot_hook.af_packet_priv = sk; 3103 3104 if (proto) { 3105 po->prot_hook.type = proto; 3106 register_prot_hook(sk); 3107 } 3108 3109 mutex_lock(&net->packet.sklist_lock); 3110 sk_add_node_rcu(sk, &net->packet.sklist); 3111 mutex_unlock(&net->packet.sklist_lock); 3112 3113 preempt_disable(); 3114 sock_prot_inuse_add(net, &packet_proto, 1); 3115 preempt_enable(); 3116 3117 return 0; 3118 out2: 3119 sk_free(sk); 3120 out: 3121 return err; 3122 } 3123 3124 /* 3125 * Pull a packet from our receive queue and hand it to the user. 3126 * If necessary we block. 3127 */ 3128 3129 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3130 int flags) 3131 { 3132 struct sock *sk = sock->sk; 3133 struct sk_buff *skb; 3134 int copied, err; 3135 int vnet_hdr_len = 0; 3136 unsigned int origlen = 0; 3137 3138 err = -EINVAL; 3139 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3140 goto out; 3141 3142 #if 0 3143 /* What error should we return now? EUNATTACH? */ 3144 if (pkt_sk(sk)->ifindex < 0) 3145 return -ENODEV; 3146 #endif 3147 3148 if (flags & MSG_ERRQUEUE) { 3149 err = sock_recv_errqueue(sk, msg, len, 3150 SOL_PACKET, PACKET_TX_TIMESTAMP); 3151 goto out; 3152 } 3153 3154 /* 3155 * Call the generic datagram receiver. This handles all sorts 3156 * of horrible races and re-entrancy so we can forget about it 3157 * in the protocol layers. 3158 * 3159 * Now it will return ENETDOWN, if device have just gone down, 3160 * but then it will block. 3161 */ 3162 3163 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3164 3165 /* 3166 * An error occurred so return it. Because skb_recv_datagram() 3167 * handles the blocking we don't see and worry about blocking 3168 * retries. 3169 */ 3170 3171 if (skb == NULL) 3172 goto out; 3173 3174 if (pkt_sk(sk)->pressure) 3175 packet_rcv_has_room(pkt_sk(sk), NULL); 3176 3177 if (pkt_sk(sk)->has_vnet_hdr) { 3178 struct virtio_net_hdr vnet_hdr = { 0 }; 3179 3180 err = -EINVAL; 3181 vnet_hdr_len = sizeof(vnet_hdr); 3182 if (len < vnet_hdr_len) 3183 goto out_free; 3184 3185 len -= vnet_hdr_len; 3186 3187 if (skb_is_gso(skb)) { 3188 struct skb_shared_info *sinfo = skb_shinfo(skb); 3189 3190 /* This is a hint as to how much should be linear. */ 3191 vnet_hdr.hdr_len = 3192 __cpu_to_virtio16(vio_le(), skb_headlen(skb)); 3193 vnet_hdr.gso_size = 3194 __cpu_to_virtio16(vio_le(), sinfo->gso_size); 3195 if (sinfo->gso_type & SKB_GSO_TCPV4) 3196 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 3197 else if (sinfo->gso_type & SKB_GSO_TCPV6) 3198 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 3199 else if (sinfo->gso_type & SKB_GSO_UDP) 3200 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 3201 else if (sinfo->gso_type & SKB_GSO_FCOE) 3202 goto out_free; 3203 else 3204 BUG(); 3205 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 3206 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 3207 } else 3208 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 3209 3210 if (skb->ip_summed == CHECKSUM_PARTIAL) { 3211 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 3212 vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(), 3213 skb_checksum_start_offset(skb)); 3214 vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(), 3215 skb->csum_offset); 3216 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3217 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; 3218 } /* else everything is zero */ 3219 3220 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len); 3221 if (err < 0) 3222 goto out_free; 3223 } 3224 3225 /* You lose any data beyond the buffer you gave. If it worries 3226 * a user program they can ask the device for its MTU 3227 * anyway. 3228 */ 3229 copied = skb->len; 3230 if (copied > len) { 3231 copied = len; 3232 msg->msg_flags |= MSG_TRUNC; 3233 } 3234 3235 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3236 if (err) 3237 goto out_free; 3238 3239 if (sock->type != SOCK_PACKET) { 3240 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3241 3242 /* Original length was stored in sockaddr_ll fields */ 3243 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3244 sll->sll_family = AF_PACKET; 3245 sll->sll_protocol = skb->protocol; 3246 } 3247 3248 sock_recv_ts_and_drops(msg, sk, skb); 3249 3250 if (msg->msg_name) { 3251 /* If the address length field is there to be filled 3252 * in, we fill it in now. 3253 */ 3254 if (sock->type == SOCK_PACKET) { 3255 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3256 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3257 } else { 3258 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3259 3260 msg->msg_namelen = sll->sll_halen + 3261 offsetof(struct sockaddr_ll, sll_addr); 3262 } 3263 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 3264 msg->msg_namelen); 3265 } 3266 3267 if (pkt_sk(sk)->auxdata) { 3268 struct tpacket_auxdata aux; 3269 3270 aux.tp_status = TP_STATUS_USER; 3271 if (skb->ip_summed == CHECKSUM_PARTIAL) 3272 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3273 else if (skb->pkt_type != PACKET_OUTGOING && 3274 (skb->ip_summed == CHECKSUM_COMPLETE || 3275 skb_csum_unnecessary(skb))) 3276 aux.tp_status |= TP_STATUS_CSUM_VALID; 3277 3278 aux.tp_len = origlen; 3279 aux.tp_snaplen = skb->len; 3280 aux.tp_mac = 0; 3281 aux.tp_net = skb_network_offset(skb); 3282 if (skb_vlan_tag_present(skb)) { 3283 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3284 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3285 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3286 } else { 3287 aux.tp_vlan_tci = 0; 3288 aux.tp_vlan_tpid = 0; 3289 } 3290 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3291 } 3292 3293 /* 3294 * Free or return the buffer as appropriate. Again this 3295 * hides all the races and re-entrancy issues from us. 3296 */ 3297 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3298 3299 out_free: 3300 skb_free_datagram(sk, skb); 3301 out: 3302 return err; 3303 } 3304 3305 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3306 int *uaddr_len, int peer) 3307 { 3308 struct net_device *dev; 3309 struct sock *sk = sock->sk; 3310 3311 if (peer) 3312 return -EOPNOTSUPP; 3313 3314 uaddr->sa_family = AF_PACKET; 3315 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3316 rcu_read_lock(); 3317 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3318 if (dev) 3319 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3320 rcu_read_unlock(); 3321 *uaddr_len = sizeof(*uaddr); 3322 3323 return 0; 3324 } 3325 3326 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3327 int *uaddr_len, int peer) 3328 { 3329 struct net_device *dev; 3330 struct sock *sk = sock->sk; 3331 struct packet_sock *po = pkt_sk(sk); 3332 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3333 3334 if (peer) 3335 return -EOPNOTSUPP; 3336 3337 sll->sll_family = AF_PACKET; 3338 sll->sll_ifindex = po->ifindex; 3339 sll->sll_protocol = po->num; 3340 sll->sll_pkttype = 0; 3341 rcu_read_lock(); 3342 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3343 if (dev) { 3344 sll->sll_hatype = dev->type; 3345 sll->sll_halen = dev->addr_len; 3346 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3347 } else { 3348 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3349 sll->sll_halen = 0; 3350 } 3351 rcu_read_unlock(); 3352 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3353 3354 return 0; 3355 } 3356 3357 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3358 int what) 3359 { 3360 switch (i->type) { 3361 case PACKET_MR_MULTICAST: 3362 if (i->alen != dev->addr_len) 3363 return -EINVAL; 3364 if (what > 0) 3365 return dev_mc_add(dev, i->addr); 3366 else 3367 return dev_mc_del(dev, i->addr); 3368 break; 3369 case PACKET_MR_PROMISC: 3370 return dev_set_promiscuity(dev, what); 3371 case PACKET_MR_ALLMULTI: 3372 return dev_set_allmulti(dev, what); 3373 case PACKET_MR_UNICAST: 3374 if (i->alen != dev->addr_len) 3375 return -EINVAL; 3376 if (what > 0) 3377 return dev_uc_add(dev, i->addr); 3378 else 3379 return dev_uc_del(dev, i->addr); 3380 break; 3381 default: 3382 break; 3383 } 3384 return 0; 3385 } 3386 3387 static void packet_dev_mclist_delete(struct net_device *dev, 3388 struct packet_mclist **mlp) 3389 { 3390 struct packet_mclist *ml; 3391 3392 while ((ml = *mlp) != NULL) { 3393 if (ml->ifindex == dev->ifindex) { 3394 packet_dev_mc(dev, ml, -1); 3395 *mlp = ml->next; 3396 kfree(ml); 3397 } else 3398 mlp = &ml->next; 3399 } 3400 } 3401 3402 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3403 { 3404 struct packet_sock *po = pkt_sk(sk); 3405 struct packet_mclist *ml, *i; 3406 struct net_device *dev; 3407 int err; 3408 3409 rtnl_lock(); 3410 3411 err = -ENODEV; 3412 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3413 if (!dev) 3414 goto done; 3415 3416 err = -EINVAL; 3417 if (mreq->mr_alen > dev->addr_len) 3418 goto done; 3419 3420 err = -ENOBUFS; 3421 i = kmalloc(sizeof(*i), GFP_KERNEL); 3422 if (i == NULL) 3423 goto done; 3424 3425 err = 0; 3426 for (ml = po->mclist; ml; ml = ml->next) { 3427 if (ml->ifindex == mreq->mr_ifindex && 3428 ml->type == mreq->mr_type && 3429 ml->alen == mreq->mr_alen && 3430 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3431 ml->count++; 3432 /* Free the new element ... */ 3433 kfree(i); 3434 goto done; 3435 } 3436 } 3437 3438 i->type = mreq->mr_type; 3439 i->ifindex = mreq->mr_ifindex; 3440 i->alen = mreq->mr_alen; 3441 memcpy(i->addr, mreq->mr_address, i->alen); 3442 i->count = 1; 3443 i->next = po->mclist; 3444 po->mclist = i; 3445 err = packet_dev_mc(dev, i, 1); 3446 if (err) { 3447 po->mclist = i->next; 3448 kfree(i); 3449 } 3450 3451 done: 3452 rtnl_unlock(); 3453 return err; 3454 } 3455 3456 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3457 { 3458 struct packet_mclist *ml, **mlp; 3459 3460 rtnl_lock(); 3461 3462 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3463 if (ml->ifindex == mreq->mr_ifindex && 3464 ml->type == mreq->mr_type && 3465 ml->alen == mreq->mr_alen && 3466 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3467 if (--ml->count == 0) { 3468 struct net_device *dev; 3469 *mlp = ml->next; 3470 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3471 if (dev) 3472 packet_dev_mc(dev, ml, -1); 3473 kfree(ml); 3474 } 3475 break; 3476 } 3477 } 3478 rtnl_unlock(); 3479 return 0; 3480 } 3481 3482 static void packet_flush_mclist(struct sock *sk) 3483 { 3484 struct packet_sock *po = pkt_sk(sk); 3485 struct packet_mclist *ml; 3486 3487 if (!po->mclist) 3488 return; 3489 3490 rtnl_lock(); 3491 while ((ml = po->mclist) != NULL) { 3492 struct net_device *dev; 3493 3494 po->mclist = ml->next; 3495 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3496 if (dev != NULL) 3497 packet_dev_mc(dev, ml, -1); 3498 kfree(ml); 3499 } 3500 rtnl_unlock(); 3501 } 3502 3503 static int 3504 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3505 { 3506 struct sock *sk = sock->sk; 3507 struct packet_sock *po = pkt_sk(sk); 3508 int ret; 3509 3510 if (level != SOL_PACKET) 3511 return -ENOPROTOOPT; 3512 3513 switch (optname) { 3514 case PACKET_ADD_MEMBERSHIP: 3515 case PACKET_DROP_MEMBERSHIP: 3516 { 3517 struct packet_mreq_max mreq; 3518 int len = optlen; 3519 memset(&mreq, 0, sizeof(mreq)); 3520 if (len < sizeof(struct packet_mreq)) 3521 return -EINVAL; 3522 if (len > sizeof(mreq)) 3523 len = sizeof(mreq); 3524 if (copy_from_user(&mreq, optval, len)) 3525 return -EFAULT; 3526 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3527 return -EINVAL; 3528 if (optname == PACKET_ADD_MEMBERSHIP) 3529 ret = packet_mc_add(sk, &mreq); 3530 else 3531 ret = packet_mc_drop(sk, &mreq); 3532 return ret; 3533 } 3534 3535 case PACKET_RX_RING: 3536 case PACKET_TX_RING: 3537 { 3538 union tpacket_req_u req_u; 3539 int len; 3540 3541 switch (po->tp_version) { 3542 case TPACKET_V1: 3543 case TPACKET_V2: 3544 len = sizeof(req_u.req); 3545 break; 3546 case TPACKET_V3: 3547 default: 3548 len = sizeof(req_u.req3); 3549 break; 3550 } 3551 if (optlen < len) 3552 return -EINVAL; 3553 if (pkt_sk(sk)->has_vnet_hdr) 3554 return -EINVAL; 3555 if (copy_from_user(&req_u.req, optval, len)) 3556 return -EFAULT; 3557 return packet_set_ring(sk, &req_u, 0, 3558 optname == PACKET_TX_RING); 3559 } 3560 case PACKET_COPY_THRESH: 3561 { 3562 int val; 3563 3564 if (optlen != sizeof(val)) 3565 return -EINVAL; 3566 if (copy_from_user(&val, optval, sizeof(val))) 3567 return -EFAULT; 3568 3569 pkt_sk(sk)->copy_thresh = val; 3570 return 0; 3571 } 3572 case PACKET_VERSION: 3573 { 3574 int val; 3575 3576 if (optlen != sizeof(val)) 3577 return -EINVAL; 3578 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3579 return -EBUSY; 3580 if (copy_from_user(&val, optval, sizeof(val))) 3581 return -EFAULT; 3582 switch (val) { 3583 case TPACKET_V1: 3584 case TPACKET_V2: 3585 case TPACKET_V3: 3586 po->tp_version = val; 3587 return 0; 3588 default: 3589 return -EINVAL; 3590 } 3591 } 3592 case PACKET_RESERVE: 3593 { 3594 unsigned int val; 3595 3596 if (optlen != sizeof(val)) 3597 return -EINVAL; 3598 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3599 return -EBUSY; 3600 if (copy_from_user(&val, optval, sizeof(val))) 3601 return -EFAULT; 3602 po->tp_reserve = val; 3603 return 0; 3604 } 3605 case PACKET_LOSS: 3606 { 3607 unsigned int val; 3608 3609 if (optlen != sizeof(val)) 3610 return -EINVAL; 3611 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3612 return -EBUSY; 3613 if (copy_from_user(&val, optval, sizeof(val))) 3614 return -EFAULT; 3615 po->tp_loss = !!val; 3616 return 0; 3617 } 3618 case PACKET_AUXDATA: 3619 { 3620 int val; 3621 3622 if (optlen < sizeof(val)) 3623 return -EINVAL; 3624 if (copy_from_user(&val, optval, sizeof(val))) 3625 return -EFAULT; 3626 3627 po->auxdata = !!val; 3628 return 0; 3629 } 3630 case PACKET_ORIGDEV: 3631 { 3632 int val; 3633 3634 if (optlen < sizeof(val)) 3635 return -EINVAL; 3636 if (copy_from_user(&val, optval, sizeof(val))) 3637 return -EFAULT; 3638 3639 po->origdev = !!val; 3640 return 0; 3641 } 3642 case PACKET_VNET_HDR: 3643 { 3644 int val; 3645 3646 if (sock->type != SOCK_RAW) 3647 return -EINVAL; 3648 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3649 return -EBUSY; 3650 if (optlen < sizeof(val)) 3651 return -EINVAL; 3652 if (copy_from_user(&val, optval, sizeof(val))) 3653 return -EFAULT; 3654 3655 po->has_vnet_hdr = !!val; 3656 return 0; 3657 } 3658 case PACKET_TIMESTAMP: 3659 { 3660 int val; 3661 3662 if (optlen != sizeof(val)) 3663 return -EINVAL; 3664 if (copy_from_user(&val, optval, sizeof(val))) 3665 return -EFAULT; 3666 3667 po->tp_tstamp = val; 3668 return 0; 3669 } 3670 case PACKET_FANOUT: 3671 { 3672 int val; 3673 3674 if (optlen != sizeof(val)) 3675 return -EINVAL; 3676 if (copy_from_user(&val, optval, sizeof(val))) 3677 return -EFAULT; 3678 3679 return fanout_add(sk, val & 0xffff, val >> 16); 3680 } 3681 case PACKET_FANOUT_DATA: 3682 { 3683 if (!po->fanout) 3684 return -EINVAL; 3685 3686 return fanout_set_data(po, optval, optlen); 3687 } 3688 case PACKET_TX_HAS_OFF: 3689 { 3690 unsigned int val; 3691 3692 if (optlen != sizeof(val)) 3693 return -EINVAL; 3694 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3695 return -EBUSY; 3696 if (copy_from_user(&val, optval, sizeof(val))) 3697 return -EFAULT; 3698 po->tp_tx_has_off = !!val; 3699 return 0; 3700 } 3701 case PACKET_QDISC_BYPASS: 3702 { 3703 int val; 3704 3705 if (optlen != sizeof(val)) 3706 return -EINVAL; 3707 if (copy_from_user(&val, optval, sizeof(val))) 3708 return -EFAULT; 3709 3710 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3711 return 0; 3712 } 3713 default: 3714 return -ENOPROTOOPT; 3715 } 3716 } 3717 3718 static int packet_getsockopt(struct socket *sock, int level, int optname, 3719 char __user *optval, int __user *optlen) 3720 { 3721 int len; 3722 int val, lv = sizeof(val); 3723 struct sock *sk = sock->sk; 3724 struct packet_sock *po = pkt_sk(sk); 3725 void *data = &val; 3726 union tpacket_stats_u st; 3727 struct tpacket_rollover_stats rstats; 3728 3729 if (level != SOL_PACKET) 3730 return -ENOPROTOOPT; 3731 3732 if (get_user(len, optlen)) 3733 return -EFAULT; 3734 3735 if (len < 0) 3736 return -EINVAL; 3737 3738 switch (optname) { 3739 case PACKET_STATISTICS: 3740 spin_lock_bh(&sk->sk_receive_queue.lock); 3741 memcpy(&st, &po->stats, sizeof(st)); 3742 memset(&po->stats, 0, sizeof(po->stats)); 3743 spin_unlock_bh(&sk->sk_receive_queue.lock); 3744 3745 if (po->tp_version == TPACKET_V3) { 3746 lv = sizeof(struct tpacket_stats_v3); 3747 st.stats3.tp_packets += st.stats3.tp_drops; 3748 data = &st.stats3; 3749 } else { 3750 lv = sizeof(struct tpacket_stats); 3751 st.stats1.tp_packets += st.stats1.tp_drops; 3752 data = &st.stats1; 3753 } 3754 3755 break; 3756 case PACKET_AUXDATA: 3757 val = po->auxdata; 3758 break; 3759 case PACKET_ORIGDEV: 3760 val = po->origdev; 3761 break; 3762 case PACKET_VNET_HDR: 3763 val = po->has_vnet_hdr; 3764 break; 3765 case PACKET_VERSION: 3766 val = po->tp_version; 3767 break; 3768 case PACKET_HDRLEN: 3769 if (len > sizeof(int)) 3770 len = sizeof(int); 3771 if (copy_from_user(&val, optval, len)) 3772 return -EFAULT; 3773 switch (val) { 3774 case TPACKET_V1: 3775 val = sizeof(struct tpacket_hdr); 3776 break; 3777 case TPACKET_V2: 3778 val = sizeof(struct tpacket2_hdr); 3779 break; 3780 case TPACKET_V3: 3781 val = sizeof(struct tpacket3_hdr); 3782 break; 3783 default: 3784 return -EINVAL; 3785 } 3786 break; 3787 case PACKET_RESERVE: 3788 val = po->tp_reserve; 3789 break; 3790 case PACKET_LOSS: 3791 val = po->tp_loss; 3792 break; 3793 case PACKET_TIMESTAMP: 3794 val = po->tp_tstamp; 3795 break; 3796 case PACKET_FANOUT: 3797 val = (po->fanout ? 3798 ((u32)po->fanout->id | 3799 ((u32)po->fanout->type << 16) | 3800 ((u32)po->fanout->flags << 24)) : 3801 0); 3802 break; 3803 case PACKET_ROLLOVER_STATS: 3804 if (!po->rollover) 3805 return -EINVAL; 3806 rstats.tp_all = atomic_long_read(&po->rollover->num); 3807 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 3808 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 3809 data = &rstats; 3810 lv = sizeof(rstats); 3811 break; 3812 case PACKET_TX_HAS_OFF: 3813 val = po->tp_tx_has_off; 3814 break; 3815 case PACKET_QDISC_BYPASS: 3816 val = packet_use_direct_xmit(po); 3817 break; 3818 default: 3819 return -ENOPROTOOPT; 3820 } 3821 3822 if (len > lv) 3823 len = lv; 3824 if (put_user(len, optlen)) 3825 return -EFAULT; 3826 if (copy_to_user(optval, data, len)) 3827 return -EFAULT; 3828 return 0; 3829 } 3830 3831 3832 static int packet_notifier(struct notifier_block *this, 3833 unsigned long msg, void *ptr) 3834 { 3835 struct sock *sk; 3836 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3837 struct net *net = dev_net(dev); 3838 3839 rcu_read_lock(); 3840 sk_for_each_rcu(sk, &net->packet.sklist) { 3841 struct packet_sock *po = pkt_sk(sk); 3842 3843 switch (msg) { 3844 case NETDEV_UNREGISTER: 3845 if (po->mclist) 3846 packet_dev_mclist_delete(dev, &po->mclist); 3847 /* fallthrough */ 3848 3849 case NETDEV_DOWN: 3850 if (dev->ifindex == po->ifindex) { 3851 spin_lock(&po->bind_lock); 3852 if (po->running) { 3853 __unregister_prot_hook(sk, false); 3854 sk->sk_err = ENETDOWN; 3855 if (!sock_flag(sk, SOCK_DEAD)) 3856 sk->sk_error_report(sk); 3857 } 3858 if (msg == NETDEV_UNREGISTER) { 3859 packet_cached_dev_reset(po); 3860 po->ifindex = -1; 3861 if (po->prot_hook.dev) 3862 dev_put(po->prot_hook.dev); 3863 po->prot_hook.dev = NULL; 3864 } 3865 spin_unlock(&po->bind_lock); 3866 } 3867 break; 3868 case NETDEV_UP: 3869 if (dev->ifindex == po->ifindex) { 3870 spin_lock(&po->bind_lock); 3871 if (po->num) 3872 register_prot_hook(sk); 3873 spin_unlock(&po->bind_lock); 3874 } 3875 break; 3876 } 3877 } 3878 rcu_read_unlock(); 3879 return NOTIFY_DONE; 3880 } 3881 3882 3883 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3884 unsigned long arg) 3885 { 3886 struct sock *sk = sock->sk; 3887 3888 switch (cmd) { 3889 case SIOCOUTQ: 3890 { 3891 int amount = sk_wmem_alloc_get(sk); 3892 3893 return put_user(amount, (int __user *)arg); 3894 } 3895 case SIOCINQ: 3896 { 3897 struct sk_buff *skb; 3898 int amount = 0; 3899 3900 spin_lock_bh(&sk->sk_receive_queue.lock); 3901 skb = skb_peek(&sk->sk_receive_queue); 3902 if (skb) 3903 amount = skb->len; 3904 spin_unlock_bh(&sk->sk_receive_queue.lock); 3905 return put_user(amount, (int __user *)arg); 3906 } 3907 case SIOCGSTAMP: 3908 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3909 case SIOCGSTAMPNS: 3910 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3911 3912 #ifdef CONFIG_INET 3913 case SIOCADDRT: 3914 case SIOCDELRT: 3915 case SIOCDARP: 3916 case SIOCGARP: 3917 case SIOCSARP: 3918 case SIOCGIFADDR: 3919 case SIOCSIFADDR: 3920 case SIOCGIFBRDADDR: 3921 case SIOCSIFBRDADDR: 3922 case SIOCGIFNETMASK: 3923 case SIOCSIFNETMASK: 3924 case SIOCGIFDSTADDR: 3925 case SIOCSIFDSTADDR: 3926 case SIOCSIFFLAGS: 3927 return inet_dgram_ops.ioctl(sock, cmd, arg); 3928 #endif 3929 3930 default: 3931 return -ENOIOCTLCMD; 3932 } 3933 return 0; 3934 } 3935 3936 static unsigned int packet_poll(struct file *file, struct socket *sock, 3937 poll_table *wait) 3938 { 3939 struct sock *sk = sock->sk; 3940 struct packet_sock *po = pkt_sk(sk); 3941 unsigned int mask = datagram_poll(file, sock, wait); 3942 3943 spin_lock_bh(&sk->sk_receive_queue.lock); 3944 if (po->rx_ring.pg_vec) { 3945 if (!packet_previous_rx_frame(po, &po->rx_ring, 3946 TP_STATUS_KERNEL)) 3947 mask |= POLLIN | POLLRDNORM; 3948 } 3949 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 3950 po->pressure = 0; 3951 spin_unlock_bh(&sk->sk_receive_queue.lock); 3952 spin_lock_bh(&sk->sk_write_queue.lock); 3953 if (po->tx_ring.pg_vec) { 3954 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 3955 mask |= POLLOUT | POLLWRNORM; 3956 } 3957 spin_unlock_bh(&sk->sk_write_queue.lock); 3958 return mask; 3959 } 3960 3961 3962 /* Dirty? Well, I still did not learn better way to account 3963 * for user mmaps. 3964 */ 3965 3966 static void packet_mm_open(struct vm_area_struct *vma) 3967 { 3968 struct file *file = vma->vm_file; 3969 struct socket *sock = file->private_data; 3970 struct sock *sk = sock->sk; 3971 3972 if (sk) 3973 atomic_inc(&pkt_sk(sk)->mapped); 3974 } 3975 3976 static void packet_mm_close(struct vm_area_struct *vma) 3977 { 3978 struct file *file = vma->vm_file; 3979 struct socket *sock = file->private_data; 3980 struct sock *sk = sock->sk; 3981 3982 if (sk) 3983 atomic_dec(&pkt_sk(sk)->mapped); 3984 } 3985 3986 static const struct vm_operations_struct packet_mmap_ops = { 3987 .open = packet_mm_open, 3988 .close = packet_mm_close, 3989 }; 3990 3991 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 3992 unsigned int len) 3993 { 3994 int i; 3995 3996 for (i = 0; i < len; i++) { 3997 if (likely(pg_vec[i].buffer)) { 3998 if (is_vmalloc_addr(pg_vec[i].buffer)) 3999 vfree(pg_vec[i].buffer); 4000 else 4001 free_pages((unsigned long)pg_vec[i].buffer, 4002 order); 4003 pg_vec[i].buffer = NULL; 4004 } 4005 } 4006 kfree(pg_vec); 4007 } 4008 4009 static char *alloc_one_pg_vec_page(unsigned long order) 4010 { 4011 char *buffer; 4012 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4013 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4014 4015 buffer = (char *) __get_free_pages(gfp_flags, order); 4016 if (buffer) 4017 return buffer; 4018 4019 /* __get_free_pages failed, fall back to vmalloc */ 4020 buffer = vzalloc((1 << order) * PAGE_SIZE); 4021 if (buffer) 4022 return buffer; 4023 4024 /* vmalloc failed, lets dig into swap here */ 4025 gfp_flags &= ~__GFP_NORETRY; 4026 buffer = (char *) __get_free_pages(gfp_flags, order); 4027 if (buffer) 4028 return buffer; 4029 4030 /* complete and utter failure */ 4031 return NULL; 4032 } 4033 4034 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4035 { 4036 unsigned int block_nr = req->tp_block_nr; 4037 struct pgv *pg_vec; 4038 int i; 4039 4040 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 4041 if (unlikely(!pg_vec)) 4042 goto out; 4043 4044 for (i = 0; i < block_nr; i++) { 4045 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4046 if (unlikely(!pg_vec[i].buffer)) 4047 goto out_free_pgvec; 4048 } 4049 4050 out: 4051 return pg_vec; 4052 4053 out_free_pgvec: 4054 free_pg_vec(pg_vec, order, block_nr); 4055 pg_vec = NULL; 4056 goto out; 4057 } 4058 4059 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4060 int closing, int tx_ring) 4061 { 4062 struct pgv *pg_vec = NULL; 4063 struct packet_sock *po = pkt_sk(sk); 4064 int was_running, order = 0; 4065 struct packet_ring_buffer *rb; 4066 struct sk_buff_head *rb_queue; 4067 __be16 num; 4068 int err = -EINVAL; 4069 /* Added to avoid minimal code churn */ 4070 struct tpacket_req *req = &req_u->req; 4071 4072 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ 4073 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { 4074 WARN(1, "Tx-ring is not supported.\n"); 4075 goto out; 4076 } 4077 4078 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4079 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4080 4081 err = -EBUSY; 4082 if (!closing) { 4083 if (atomic_read(&po->mapped)) 4084 goto out; 4085 if (packet_read_pending(rb)) 4086 goto out; 4087 } 4088 4089 if (req->tp_block_nr) { 4090 /* Sanity tests and some calculations */ 4091 err = -EBUSY; 4092 if (unlikely(rb->pg_vec)) 4093 goto out; 4094 4095 switch (po->tp_version) { 4096 case TPACKET_V1: 4097 po->tp_hdrlen = TPACKET_HDRLEN; 4098 break; 4099 case TPACKET_V2: 4100 po->tp_hdrlen = TPACKET2_HDRLEN; 4101 break; 4102 case TPACKET_V3: 4103 po->tp_hdrlen = TPACKET3_HDRLEN; 4104 break; 4105 } 4106 4107 err = -EINVAL; 4108 if (unlikely((int)req->tp_block_size <= 0)) 4109 goto out; 4110 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 4111 goto out; 4112 if (po->tp_version >= TPACKET_V3 && 4113 (int)(req->tp_block_size - 4114 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) 4115 goto out; 4116 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 4117 po->tp_reserve)) 4118 goto out; 4119 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4120 goto out; 4121 4122 rb->frames_per_block = req->tp_block_size/req->tp_frame_size; 4123 if (unlikely(rb->frames_per_block <= 0)) 4124 goto out; 4125 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4126 req->tp_frame_nr)) 4127 goto out; 4128 4129 err = -ENOMEM; 4130 order = get_order(req->tp_block_size); 4131 pg_vec = alloc_pg_vec(req, order); 4132 if (unlikely(!pg_vec)) 4133 goto out; 4134 switch (po->tp_version) { 4135 case TPACKET_V3: 4136 /* Transmit path is not supported. We checked 4137 * it above but just being paranoid 4138 */ 4139 if (!tx_ring) 4140 init_prb_bdqc(po, rb, pg_vec, req_u); 4141 break; 4142 default: 4143 break; 4144 } 4145 } 4146 /* Done */ 4147 else { 4148 err = -EINVAL; 4149 if (unlikely(req->tp_frame_nr)) 4150 goto out; 4151 } 4152 4153 lock_sock(sk); 4154 4155 /* Detach socket from network */ 4156 spin_lock(&po->bind_lock); 4157 was_running = po->running; 4158 num = po->num; 4159 if (was_running) { 4160 po->num = 0; 4161 __unregister_prot_hook(sk, false); 4162 } 4163 spin_unlock(&po->bind_lock); 4164 4165 synchronize_net(); 4166 4167 err = -EBUSY; 4168 mutex_lock(&po->pg_vec_lock); 4169 if (closing || atomic_read(&po->mapped) == 0) { 4170 err = 0; 4171 spin_lock_bh(&rb_queue->lock); 4172 swap(rb->pg_vec, pg_vec); 4173 rb->frame_max = (req->tp_frame_nr - 1); 4174 rb->head = 0; 4175 rb->frame_size = req->tp_frame_size; 4176 spin_unlock_bh(&rb_queue->lock); 4177 4178 swap(rb->pg_vec_order, order); 4179 swap(rb->pg_vec_len, req->tp_block_nr); 4180 4181 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4182 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4183 tpacket_rcv : packet_rcv; 4184 skb_queue_purge(rb_queue); 4185 if (atomic_read(&po->mapped)) 4186 pr_err("packet_mmap: vma is busy: %d\n", 4187 atomic_read(&po->mapped)); 4188 } 4189 mutex_unlock(&po->pg_vec_lock); 4190 4191 spin_lock(&po->bind_lock); 4192 if (was_running) { 4193 po->num = num; 4194 register_prot_hook(sk); 4195 } 4196 spin_unlock(&po->bind_lock); 4197 if (closing && (po->tp_version > TPACKET_V2)) { 4198 /* Because we don't support block-based V3 on tx-ring */ 4199 if (!tx_ring) 4200 prb_shutdown_retire_blk_timer(po, rb_queue); 4201 } 4202 release_sock(sk); 4203 4204 if (pg_vec) 4205 free_pg_vec(pg_vec, order, req->tp_block_nr); 4206 out: 4207 return err; 4208 } 4209 4210 static int packet_mmap(struct file *file, struct socket *sock, 4211 struct vm_area_struct *vma) 4212 { 4213 struct sock *sk = sock->sk; 4214 struct packet_sock *po = pkt_sk(sk); 4215 unsigned long size, expected_size; 4216 struct packet_ring_buffer *rb; 4217 unsigned long start; 4218 int err = -EINVAL; 4219 int i; 4220 4221 if (vma->vm_pgoff) 4222 return -EINVAL; 4223 4224 mutex_lock(&po->pg_vec_lock); 4225 4226 expected_size = 0; 4227 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4228 if (rb->pg_vec) { 4229 expected_size += rb->pg_vec_len 4230 * rb->pg_vec_pages 4231 * PAGE_SIZE; 4232 } 4233 } 4234 4235 if (expected_size == 0) 4236 goto out; 4237 4238 size = vma->vm_end - vma->vm_start; 4239 if (size != expected_size) 4240 goto out; 4241 4242 start = vma->vm_start; 4243 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4244 if (rb->pg_vec == NULL) 4245 continue; 4246 4247 for (i = 0; i < rb->pg_vec_len; i++) { 4248 struct page *page; 4249 void *kaddr = rb->pg_vec[i].buffer; 4250 int pg_num; 4251 4252 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4253 page = pgv_to_page(kaddr); 4254 err = vm_insert_page(vma, start, page); 4255 if (unlikely(err)) 4256 goto out; 4257 start += PAGE_SIZE; 4258 kaddr += PAGE_SIZE; 4259 } 4260 } 4261 } 4262 4263 atomic_inc(&po->mapped); 4264 vma->vm_ops = &packet_mmap_ops; 4265 err = 0; 4266 4267 out: 4268 mutex_unlock(&po->pg_vec_lock); 4269 return err; 4270 } 4271 4272 static const struct proto_ops packet_ops_spkt = { 4273 .family = PF_PACKET, 4274 .owner = THIS_MODULE, 4275 .release = packet_release, 4276 .bind = packet_bind_spkt, 4277 .connect = sock_no_connect, 4278 .socketpair = sock_no_socketpair, 4279 .accept = sock_no_accept, 4280 .getname = packet_getname_spkt, 4281 .poll = datagram_poll, 4282 .ioctl = packet_ioctl, 4283 .listen = sock_no_listen, 4284 .shutdown = sock_no_shutdown, 4285 .setsockopt = sock_no_setsockopt, 4286 .getsockopt = sock_no_getsockopt, 4287 .sendmsg = packet_sendmsg_spkt, 4288 .recvmsg = packet_recvmsg, 4289 .mmap = sock_no_mmap, 4290 .sendpage = sock_no_sendpage, 4291 }; 4292 4293 static const struct proto_ops packet_ops = { 4294 .family = PF_PACKET, 4295 .owner = THIS_MODULE, 4296 .release = packet_release, 4297 .bind = packet_bind, 4298 .connect = sock_no_connect, 4299 .socketpair = sock_no_socketpair, 4300 .accept = sock_no_accept, 4301 .getname = packet_getname, 4302 .poll = packet_poll, 4303 .ioctl = packet_ioctl, 4304 .listen = sock_no_listen, 4305 .shutdown = sock_no_shutdown, 4306 .setsockopt = packet_setsockopt, 4307 .getsockopt = packet_getsockopt, 4308 .sendmsg = packet_sendmsg, 4309 .recvmsg = packet_recvmsg, 4310 .mmap = packet_mmap, 4311 .sendpage = sock_no_sendpage, 4312 }; 4313 4314 static const struct net_proto_family packet_family_ops = { 4315 .family = PF_PACKET, 4316 .create = packet_create, 4317 .owner = THIS_MODULE, 4318 }; 4319 4320 static struct notifier_block packet_netdev_notifier = { 4321 .notifier_call = packet_notifier, 4322 }; 4323 4324 #ifdef CONFIG_PROC_FS 4325 4326 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4327 __acquires(RCU) 4328 { 4329 struct net *net = seq_file_net(seq); 4330 4331 rcu_read_lock(); 4332 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4333 } 4334 4335 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4336 { 4337 struct net *net = seq_file_net(seq); 4338 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4339 } 4340 4341 static void packet_seq_stop(struct seq_file *seq, void *v) 4342 __releases(RCU) 4343 { 4344 rcu_read_unlock(); 4345 } 4346 4347 static int packet_seq_show(struct seq_file *seq, void *v) 4348 { 4349 if (v == SEQ_START_TOKEN) 4350 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4351 else { 4352 struct sock *s = sk_entry(v); 4353 const struct packet_sock *po = pkt_sk(s); 4354 4355 seq_printf(seq, 4356 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4357 s, 4358 atomic_read(&s->sk_refcnt), 4359 s->sk_type, 4360 ntohs(po->num), 4361 po->ifindex, 4362 po->running, 4363 atomic_read(&s->sk_rmem_alloc), 4364 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4365 sock_i_ino(s)); 4366 } 4367 4368 return 0; 4369 } 4370 4371 static const struct seq_operations packet_seq_ops = { 4372 .start = packet_seq_start, 4373 .next = packet_seq_next, 4374 .stop = packet_seq_stop, 4375 .show = packet_seq_show, 4376 }; 4377 4378 static int packet_seq_open(struct inode *inode, struct file *file) 4379 { 4380 return seq_open_net(inode, file, &packet_seq_ops, 4381 sizeof(struct seq_net_private)); 4382 } 4383 4384 static const struct file_operations packet_seq_fops = { 4385 .owner = THIS_MODULE, 4386 .open = packet_seq_open, 4387 .read = seq_read, 4388 .llseek = seq_lseek, 4389 .release = seq_release_net, 4390 }; 4391 4392 #endif 4393 4394 static int __net_init packet_net_init(struct net *net) 4395 { 4396 mutex_init(&net->packet.sklist_lock); 4397 INIT_HLIST_HEAD(&net->packet.sklist); 4398 4399 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4400 return -ENOMEM; 4401 4402 return 0; 4403 } 4404 4405 static void __net_exit packet_net_exit(struct net *net) 4406 { 4407 remove_proc_entry("packet", net->proc_net); 4408 } 4409 4410 static struct pernet_operations packet_net_ops = { 4411 .init = packet_net_init, 4412 .exit = packet_net_exit, 4413 }; 4414 4415 4416 static void __exit packet_exit(void) 4417 { 4418 unregister_netdevice_notifier(&packet_netdev_notifier); 4419 unregister_pernet_subsys(&packet_net_ops); 4420 sock_unregister(PF_PACKET); 4421 proto_unregister(&packet_proto); 4422 } 4423 4424 static int __init packet_init(void) 4425 { 4426 int rc = proto_register(&packet_proto, 0); 4427 4428 if (rc != 0) 4429 goto out; 4430 4431 sock_register(&packet_family_ops); 4432 register_pernet_subsys(&packet_net_ops); 4433 register_netdevice_notifier(&packet_netdev_notifier); 4434 out: 4435 return rc; 4436 } 4437 4438 module_init(packet_init); 4439 module_exit(packet_exit); 4440 MODULE_LICENSE("GPL"); 4441 MODULE_ALIAS_NETPROTO(PF_PACKET); 4442