1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <linux/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/percpu.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 #include <linux/bpf.h> 96 #include <net/compat.h> 97 98 #include "internal.h" 99 100 /* 101 Assumptions: 102 - if device has no dev->hard_header routine, it adds and removes ll header 103 inside itself. In this case ll header is invisible outside of device, 104 but higher levels still should reserve dev->hard_header_len. 105 Some devices are enough clever to reallocate skb, when header 106 will not fit to reserved space (tunnel), another ones are silly 107 (PPP). 108 - packet socket receives packets with pulled ll header, 109 so that SOCK_RAW should push it back. 110 111 On receive: 112 ----------- 113 114 Incoming, dev->hard_header!=NULL 115 mac_header -> ll header 116 data -> data 117 118 Outgoing, dev->hard_header!=NULL 119 mac_header -> ll header 120 data -> ll header 121 122 Incoming, dev->hard_header==NULL 123 mac_header -> UNKNOWN position. It is very likely, that it points to ll 124 header. PPP makes it, that is wrong, because introduce 125 assymetry between rx and tx paths. 126 data -> data 127 128 Outgoing, dev->hard_header==NULL 129 mac_header -> data. ll header is still not built! 130 data -> data 131 132 Resume 133 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 134 135 136 On transmit: 137 ------------ 138 139 dev->hard_header != NULL 140 mac_header -> ll header 141 data -> ll header 142 143 dev->hard_header == NULL (ll header is added by device, we cannot control it) 144 mac_header -> data 145 data -> data 146 147 We should set nh.raw on output to correct posistion, 148 packet classifier depends on it. 149 */ 150 151 /* Private packet socket structures. */ 152 153 /* identical to struct packet_mreq except it has 154 * a longer address field. 155 */ 156 struct packet_mreq_max { 157 int mr_ifindex; 158 unsigned short mr_type; 159 unsigned short mr_alen; 160 unsigned char mr_address[MAX_ADDR_LEN]; 161 }; 162 163 union tpacket_uhdr { 164 struct tpacket_hdr *h1; 165 struct tpacket2_hdr *h2; 166 struct tpacket3_hdr *h3; 167 void *raw; 168 }; 169 170 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 171 int closing, int tx_ring); 172 173 #define V3_ALIGNMENT (8) 174 175 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 176 177 #define BLK_PLUS_PRIV(sz_of_priv) \ 178 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 179 180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 187 188 struct packet_sock; 189 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 190 struct packet_type *pt, struct net_device *orig_dev); 191 192 static void *packet_previous_frame(struct packet_sock *po, 193 struct packet_ring_buffer *rb, 194 int status); 195 static void packet_increment_head(struct packet_ring_buffer *buff); 196 static int prb_curr_blk_in_use(struct tpacket_block_desc *); 197 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 198 struct packet_sock *); 199 static void prb_retire_current_block(struct tpacket_kbdq_core *, 200 struct packet_sock *, unsigned int status); 201 static int prb_queue_frozen(struct tpacket_kbdq_core *); 202 static void prb_open_block(struct tpacket_kbdq_core *, 203 struct tpacket_block_desc *); 204 static void prb_retire_rx_blk_timer_expired(unsigned long); 205 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 206 static void prb_init_blk_timer(struct packet_sock *, 207 struct tpacket_kbdq_core *, 208 void (*func) (unsigned long)); 209 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 210 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 211 struct tpacket3_hdr *); 212 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 213 struct tpacket3_hdr *); 214 static void packet_flush_mclist(struct sock *sk); 215 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb); 216 217 struct packet_skb_cb { 218 union { 219 struct sockaddr_pkt pkt; 220 union { 221 /* Trick: alias skb original length with 222 * ll.sll_family and ll.protocol in order 223 * to save room. 224 */ 225 unsigned int origlen; 226 struct sockaddr_ll ll; 227 }; 228 } sa; 229 }; 230 231 #define vio_le() virtio_legacy_is_little_endian() 232 233 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 234 235 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 236 #define GET_PBLOCK_DESC(x, bid) \ 237 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 238 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 239 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 240 #define GET_NEXT_PRB_BLK_NUM(x) \ 241 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 242 ((x)->kactive_blk_num+1) : 0) 243 244 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 245 static void __fanout_link(struct sock *sk, struct packet_sock *po); 246 247 static int packet_direct_xmit(struct sk_buff *skb) 248 { 249 struct net_device *dev = skb->dev; 250 struct sk_buff *orig_skb = skb; 251 struct netdev_queue *txq; 252 int ret = NETDEV_TX_BUSY; 253 254 if (unlikely(!netif_running(dev) || 255 !netif_carrier_ok(dev))) 256 goto drop; 257 258 skb = validate_xmit_skb_list(skb, dev); 259 if (skb != orig_skb) 260 goto drop; 261 262 packet_pick_tx_queue(dev, skb); 263 txq = skb_get_tx_queue(dev, skb); 264 265 local_bh_disable(); 266 267 HARD_TX_LOCK(dev, txq, smp_processor_id()); 268 if (!netif_xmit_frozen_or_drv_stopped(txq)) 269 ret = netdev_start_xmit(skb, dev, txq, false); 270 HARD_TX_UNLOCK(dev, txq); 271 272 local_bh_enable(); 273 274 if (!dev_xmit_complete(ret)) 275 kfree_skb(skb); 276 277 return ret; 278 drop: 279 atomic_long_inc(&dev->tx_dropped); 280 kfree_skb_list(skb); 281 return NET_XMIT_DROP; 282 } 283 284 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 285 { 286 struct net_device *dev; 287 288 rcu_read_lock(); 289 dev = rcu_dereference(po->cached_dev); 290 if (likely(dev)) 291 dev_hold(dev); 292 rcu_read_unlock(); 293 294 return dev; 295 } 296 297 static void packet_cached_dev_assign(struct packet_sock *po, 298 struct net_device *dev) 299 { 300 rcu_assign_pointer(po->cached_dev, dev); 301 } 302 303 static void packet_cached_dev_reset(struct packet_sock *po) 304 { 305 RCU_INIT_POINTER(po->cached_dev, NULL); 306 } 307 308 static bool packet_use_direct_xmit(const struct packet_sock *po) 309 { 310 return po->xmit == packet_direct_xmit; 311 } 312 313 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 314 { 315 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues; 316 } 317 318 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 319 { 320 const struct net_device_ops *ops = dev->netdev_ops; 321 u16 queue_index; 322 323 if (ops->ndo_select_queue) { 324 queue_index = ops->ndo_select_queue(dev, skb, NULL, 325 __packet_pick_tx_queue); 326 queue_index = netdev_cap_txqueue(dev, queue_index); 327 } else { 328 queue_index = __packet_pick_tx_queue(dev, skb); 329 } 330 331 skb_set_queue_mapping(skb, queue_index); 332 } 333 334 /* register_prot_hook must be invoked with the po->bind_lock held, 335 * or from a context in which asynchronous accesses to the packet 336 * socket is not possible (packet_create()). 337 */ 338 static void register_prot_hook(struct sock *sk) 339 { 340 struct packet_sock *po = pkt_sk(sk); 341 342 if (!po->running) { 343 if (po->fanout) 344 __fanout_link(sk, po); 345 else 346 dev_add_pack(&po->prot_hook); 347 348 sock_hold(sk); 349 po->running = 1; 350 } 351 } 352 353 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 354 * held. If the sync parameter is true, we will temporarily drop 355 * the po->bind_lock and do a synchronize_net to make sure no 356 * asynchronous packet processing paths still refer to the elements 357 * of po->prot_hook. If the sync parameter is false, it is the 358 * callers responsibility to take care of this. 359 */ 360 static void __unregister_prot_hook(struct sock *sk, bool sync) 361 { 362 struct packet_sock *po = pkt_sk(sk); 363 364 po->running = 0; 365 366 if (po->fanout) 367 __fanout_unlink(sk, po); 368 else 369 __dev_remove_pack(&po->prot_hook); 370 371 __sock_put(sk); 372 373 if (sync) { 374 spin_unlock(&po->bind_lock); 375 synchronize_net(); 376 spin_lock(&po->bind_lock); 377 } 378 } 379 380 static void unregister_prot_hook(struct sock *sk, bool sync) 381 { 382 struct packet_sock *po = pkt_sk(sk); 383 384 if (po->running) 385 __unregister_prot_hook(sk, sync); 386 } 387 388 static inline struct page * __pure pgv_to_page(void *addr) 389 { 390 if (is_vmalloc_addr(addr)) 391 return vmalloc_to_page(addr); 392 return virt_to_page(addr); 393 } 394 395 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 396 { 397 union tpacket_uhdr h; 398 399 h.raw = frame; 400 switch (po->tp_version) { 401 case TPACKET_V1: 402 h.h1->tp_status = status; 403 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 404 break; 405 case TPACKET_V2: 406 h.h2->tp_status = status; 407 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 408 break; 409 case TPACKET_V3: 410 h.h3->tp_status = status; 411 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 412 break; 413 default: 414 WARN(1, "TPACKET version not supported.\n"); 415 BUG(); 416 } 417 418 smp_wmb(); 419 } 420 421 static int __packet_get_status(struct packet_sock *po, void *frame) 422 { 423 union tpacket_uhdr h; 424 425 smp_rmb(); 426 427 h.raw = frame; 428 switch (po->tp_version) { 429 case TPACKET_V1: 430 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 431 return h.h1->tp_status; 432 case TPACKET_V2: 433 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 434 return h.h2->tp_status; 435 case TPACKET_V3: 436 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 437 return h.h3->tp_status; 438 default: 439 WARN(1, "TPACKET version not supported.\n"); 440 BUG(); 441 return 0; 442 } 443 } 444 445 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 446 unsigned int flags) 447 { 448 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 449 450 if (shhwtstamps && 451 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 452 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 453 return TP_STATUS_TS_RAW_HARDWARE; 454 455 if (ktime_to_timespec_cond(skb->tstamp, ts)) 456 return TP_STATUS_TS_SOFTWARE; 457 458 return 0; 459 } 460 461 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 462 struct sk_buff *skb) 463 { 464 union tpacket_uhdr h; 465 struct timespec ts; 466 __u32 ts_status; 467 468 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 469 return 0; 470 471 h.raw = frame; 472 switch (po->tp_version) { 473 case TPACKET_V1: 474 h.h1->tp_sec = ts.tv_sec; 475 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 476 break; 477 case TPACKET_V2: 478 h.h2->tp_sec = ts.tv_sec; 479 h.h2->tp_nsec = ts.tv_nsec; 480 break; 481 case TPACKET_V3: 482 h.h3->tp_sec = ts.tv_sec; 483 h.h3->tp_nsec = ts.tv_nsec; 484 break; 485 default: 486 WARN(1, "TPACKET version not supported.\n"); 487 BUG(); 488 } 489 490 /* one flush is safe, as both fields always lie on the same cacheline */ 491 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 492 smp_wmb(); 493 494 return ts_status; 495 } 496 497 static void *packet_lookup_frame(struct packet_sock *po, 498 struct packet_ring_buffer *rb, 499 unsigned int position, 500 int status) 501 { 502 unsigned int pg_vec_pos, frame_offset; 503 union tpacket_uhdr h; 504 505 pg_vec_pos = position / rb->frames_per_block; 506 frame_offset = position % rb->frames_per_block; 507 508 h.raw = rb->pg_vec[pg_vec_pos].buffer + 509 (frame_offset * rb->frame_size); 510 511 if (status != __packet_get_status(po, h.raw)) 512 return NULL; 513 514 return h.raw; 515 } 516 517 static void *packet_current_frame(struct packet_sock *po, 518 struct packet_ring_buffer *rb, 519 int status) 520 { 521 return packet_lookup_frame(po, rb, rb->head, status); 522 } 523 524 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 525 { 526 del_timer_sync(&pkc->retire_blk_timer); 527 } 528 529 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 530 struct sk_buff_head *rb_queue) 531 { 532 struct tpacket_kbdq_core *pkc; 533 534 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 535 536 spin_lock_bh(&rb_queue->lock); 537 pkc->delete_blk_timer = 1; 538 spin_unlock_bh(&rb_queue->lock); 539 540 prb_del_retire_blk_timer(pkc); 541 } 542 543 static void prb_init_blk_timer(struct packet_sock *po, 544 struct tpacket_kbdq_core *pkc, 545 void (*func) (unsigned long)) 546 { 547 init_timer(&pkc->retire_blk_timer); 548 pkc->retire_blk_timer.data = (long)po; 549 pkc->retire_blk_timer.function = func; 550 pkc->retire_blk_timer.expires = jiffies; 551 } 552 553 static void prb_setup_retire_blk_timer(struct packet_sock *po) 554 { 555 struct tpacket_kbdq_core *pkc; 556 557 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 558 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 559 } 560 561 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 562 int blk_size_in_bytes) 563 { 564 struct net_device *dev; 565 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 566 struct ethtool_link_ksettings ecmd; 567 int err; 568 569 rtnl_lock(); 570 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 571 if (unlikely(!dev)) { 572 rtnl_unlock(); 573 return DEFAULT_PRB_RETIRE_TOV; 574 } 575 err = __ethtool_get_link_ksettings(dev, &ecmd); 576 rtnl_unlock(); 577 if (!err) { 578 /* 579 * If the link speed is so slow you don't really 580 * need to worry about perf anyways 581 */ 582 if (ecmd.base.speed < SPEED_1000 || 583 ecmd.base.speed == SPEED_UNKNOWN) { 584 return DEFAULT_PRB_RETIRE_TOV; 585 } else { 586 msec = 1; 587 div = ecmd.base.speed / 1000; 588 } 589 } 590 591 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 592 593 if (div) 594 mbits /= div; 595 596 tmo = mbits * msec; 597 598 if (div) 599 return tmo+1; 600 return tmo; 601 } 602 603 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 604 union tpacket_req_u *req_u) 605 { 606 p1->feature_req_word = req_u->req3.tp_feature_req_word; 607 } 608 609 static void init_prb_bdqc(struct packet_sock *po, 610 struct packet_ring_buffer *rb, 611 struct pgv *pg_vec, 612 union tpacket_req_u *req_u) 613 { 614 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 615 struct tpacket_block_desc *pbd; 616 617 memset(p1, 0x0, sizeof(*p1)); 618 619 p1->knxt_seq_num = 1; 620 p1->pkbdq = pg_vec; 621 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 622 p1->pkblk_start = pg_vec[0].buffer; 623 p1->kblk_size = req_u->req3.tp_block_size; 624 p1->knum_blocks = req_u->req3.tp_block_nr; 625 p1->hdrlen = po->tp_hdrlen; 626 p1->version = po->tp_version; 627 p1->last_kactive_blk_num = 0; 628 po->stats.stats3.tp_freeze_q_cnt = 0; 629 if (req_u->req3.tp_retire_blk_tov) 630 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 631 else 632 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 633 req_u->req3.tp_block_size); 634 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 635 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 636 637 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 638 prb_init_ft_ops(p1, req_u); 639 prb_setup_retire_blk_timer(po); 640 prb_open_block(p1, pbd); 641 } 642 643 /* Do NOT update the last_blk_num first. 644 * Assumes sk_buff_head lock is held. 645 */ 646 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 647 { 648 mod_timer(&pkc->retire_blk_timer, 649 jiffies + pkc->tov_in_jiffies); 650 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 651 } 652 653 /* 654 * Timer logic: 655 * 1) We refresh the timer only when we open a block. 656 * By doing this we don't waste cycles refreshing the timer 657 * on packet-by-packet basis. 658 * 659 * With a 1MB block-size, on a 1Gbps line, it will take 660 * i) ~8 ms to fill a block + ii) memcpy etc. 661 * In this cut we are not accounting for the memcpy time. 662 * 663 * So, if the user sets the 'tmo' to 10ms then the timer 664 * will never fire while the block is still getting filled 665 * (which is what we want). However, the user could choose 666 * to close a block early and that's fine. 667 * 668 * But when the timer does fire, we check whether or not to refresh it. 669 * Since the tmo granularity is in msecs, it is not too expensive 670 * to refresh the timer, lets say every '8' msecs. 671 * Either the user can set the 'tmo' or we can derive it based on 672 * a) line-speed and b) block-size. 673 * prb_calc_retire_blk_tmo() calculates the tmo. 674 * 675 */ 676 static void prb_retire_rx_blk_timer_expired(unsigned long data) 677 { 678 struct packet_sock *po = (struct packet_sock *)data; 679 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 680 unsigned int frozen; 681 struct tpacket_block_desc *pbd; 682 683 spin_lock(&po->sk.sk_receive_queue.lock); 684 685 frozen = prb_queue_frozen(pkc); 686 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 687 688 if (unlikely(pkc->delete_blk_timer)) 689 goto out; 690 691 /* We only need to plug the race when the block is partially filled. 692 * tpacket_rcv: 693 * lock(); increment BLOCK_NUM_PKTS; unlock() 694 * copy_bits() is in progress ... 695 * timer fires on other cpu: 696 * we can't retire the current block because copy_bits 697 * is in progress. 698 * 699 */ 700 if (BLOCK_NUM_PKTS(pbd)) { 701 while (atomic_read(&pkc->blk_fill_in_prog)) { 702 /* Waiting for skb_copy_bits to finish... */ 703 cpu_relax(); 704 } 705 } 706 707 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 708 if (!frozen) { 709 if (!BLOCK_NUM_PKTS(pbd)) { 710 /* An empty block. Just refresh the timer. */ 711 goto refresh_timer; 712 } 713 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 714 if (!prb_dispatch_next_block(pkc, po)) 715 goto refresh_timer; 716 else 717 goto out; 718 } else { 719 /* Case 1. Queue was frozen because user-space was 720 * lagging behind. 721 */ 722 if (prb_curr_blk_in_use(pbd)) { 723 /* 724 * Ok, user-space is still behind. 725 * So just refresh the timer. 726 */ 727 goto refresh_timer; 728 } else { 729 /* Case 2. queue was frozen,user-space caught up, 730 * now the link went idle && the timer fired. 731 * We don't have a block to close.So we open this 732 * block and restart the timer. 733 * opening a block thaws the queue,restarts timer 734 * Thawing/timer-refresh is a side effect. 735 */ 736 prb_open_block(pkc, pbd); 737 goto out; 738 } 739 } 740 } 741 742 refresh_timer: 743 _prb_refresh_rx_retire_blk_timer(pkc); 744 745 out: 746 spin_unlock(&po->sk.sk_receive_queue.lock); 747 } 748 749 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 750 struct tpacket_block_desc *pbd1, __u32 status) 751 { 752 /* Flush everything minus the block header */ 753 754 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 755 u8 *start, *end; 756 757 start = (u8 *)pbd1; 758 759 /* Skip the block header(we know header WILL fit in 4K) */ 760 start += PAGE_SIZE; 761 762 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 763 for (; start < end; start += PAGE_SIZE) 764 flush_dcache_page(pgv_to_page(start)); 765 766 smp_wmb(); 767 #endif 768 769 /* Now update the block status. */ 770 771 BLOCK_STATUS(pbd1) = status; 772 773 /* Flush the block header */ 774 775 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 776 start = (u8 *)pbd1; 777 flush_dcache_page(pgv_to_page(start)); 778 779 smp_wmb(); 780 #endif 781 } 782 783 /* 784 * Side effect: 785 * 786 * 1) flush the block 787 * 2) Increment active_blk_num 788 * 789 * Note:We DONT refresh the timer on purpose. 790 * Because almost always the next block will be opened. 791 */ 792 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 793 struct tpacket_block_desc *pbd1, 794 struct packet_sock *po, unsigned int stat) 795 { 796 __u32 status = TP_STATUS_USER | stat; 797 798 struct tpacket3_hdr *last_pkt; 799 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 800 struct sock *sk = &po->sk; 801 802 if (po->stats.stats3.tp_drops) 803 status |= TP_STATUS_LOSING; 804 805 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 806 last_pkt->tp_next_offset = 0; 807 808 /* Get the ts of the last pkt */ 809 if (BLOCK_NUM_PKTS(pbd1)) { 810 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 811 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 812 } else { 813 /* Ok, we tmo'd - so get the current time. 814 * 815 * It shouldn't really happen as we don't close empty 816 * blocks. See prb_retire_rx_blk_timer_expired(). 817 */ 818 struct timespec ts; 819 getnstimeofday(&ts); 820 h1->ts_last_pkt.ts_sec = ts.tv_sec; 821 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 822 } 823 824 smp_wmb(); 825 826 /* Flush the block */ 827 prb_flush_block(pkc1, pbd1, status); 828 829 sk->sk_data_ready(sk); 830 831 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 832 } 833 834 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 835 { 836 pkc->reset_pending_on_curr_blk = 0; 837 } 838 839 /* 840 * Side effect of opening a block: 841 * 842 * 1) prb_queue is thawed. 843 * 2) retire_blk_timer is refreshed. 844 * 845 */ 846 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 847 struct tpacket_block_desc *pbd1) 848 { 849 struct timespec ts; 850 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 851 852 smp_rmb(); 853 854 /* We could have just memset this but we will lose the 855 * flexibility of making the priv area sticky 856 */ 857 858 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 859 BLOCK_NUM_PKTS(pbd1) = 0; 860 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 861 862 getnstimeofday(&ts); 863 864 h1->ts_first_pkt.ts_sec = ts.tv_sec; 865 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 866 867 pkc1->pkblk_start = (char *)pbd1; 868 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 869 870 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 871 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 872 873 pbd1->version = pkc1->version; 874 pkc1->prev = pkc1->nxt_offset; 875 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 876 877 prb_thaw_queue(pkc1); 878 _prb_refresh_rx_retire_blk_timer(pkc1); 879 880 smp_wmb(); 881 } 882 883 /* 884 * Queue freeze logic: 885 * 1) Assume tp_block_nr = 8 blocks. 886 * 2) At time 't0', user opens Rx ring. 887 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 888 * 4) user-space is either sleeping or processing block '0'. 889 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 890 * it will close block-7,loop around and try to fill block '0'. 891 * call-flow: 892 * __packet_lookup_frame_in_block 893 * prb_retire_current_block() 894 * prb_dispatch_next_block() 895 * |->(BLOCK_STATUS == USER) evaluates to true 896 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 897 * 6) Now there are two cases: 898 * 6.1) Link goes idle right after the queue is frozen. 899 * But remember, the last open_block() refreshed the timer. 900 * When this timer expires,it will refresh itself so that we can 901 * re-open block-0 in near future. 902 * 6.2) Link is busy and keeps on receiving packets. This is a simple 903 * case and __packet_lookup_frame_in_block will check if block-0 904 * is free and can now be re-used. 905 */ 906 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 907 struct packet_sock *po) 908 { 909 pkc->reset_pending_on_curr_blk = 1; 910 po->stats.stats3.tp_freeze_q_cnt++; 911 } 912 913 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 914 915 /* 916 * If the next block is free then we will dispatch it 917 * and return a good offset. 918 * Else, we will freeze the queue. 919 * So, caller must check the return value. 920 */ 921 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 922 struct packet_sock *po) 923 { 924 struct tpacket_block_desc *pbd; 925 926 smp_rmb(); 927 928 /* 1. Get current block num */ 929 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 930 931 /* 2. If this block is currently in_use then freeze the queue */ 932 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 933 prb_freeze_queue(pkc, po); 934 return NULL; 935 } 936 937 /* 938 * 3. 939 * open this block and return the offset where the first packet 940 * needs to get stored. 941 */ 942 prb_open_block(pkc, pbd); 943 return (void *)pkc->nxt_offset; 944 } 945 946 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 947 struct packet_sock *po, unsigned int status) 948 { 949 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 950 951 /* retire/close the current block */ 952 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 953 /* 954 * Plug the case where copy_bits() is in progress on 955 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 956 * have space to copy the pkt in the current block and 957 * called prb_retire_current_block() 958 * 959 * We don't need to worry about the TMO case because 960 * the timer-handler already handled this case. 961 */ 962 if (!(status & TP_STATUS_BLK_TMO)) { 963 while (atomic_read(&pkc->blk_fill_in_prog)) { 964 /* Waiting for skb_copy_bits to finish... */ 965 cpu_relax(); 966 } 967 } 968 prb_close_block(pkc, pbd, po, status); 969 return; 970 } 971 } 972 973 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) 974 { 975 return TP_STATUS_USER & BLOCK_STATUS(pbd); 976 } 977 978 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 979 { 980 return pkc->reset_pending_on_curr_blk; 981 } 982 983 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 984 { 985 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 986 atomic_dec(&pkc->blk_fill_in_prog); 987 } 988 989 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 990 struct tpacket3_hdr *ppd) 991 { 992 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 993 } 994 995 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 996 struct tpacket3_hdr *ppd) 997 { 998 ppd->hv1.tp_rxhash = 0; 999 } 1000 1001 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 1002 struct tpacket3_hdr *ppd) 1003 { 1004 if (skb_vlan_tag_present(pkc->skb)) { 1005 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1006 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1007 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1008 } else { 1009 ppd->hv1.tp_vlan_tci = 0; 1010 ppd->hv1.tp_vlan_tpid = 0; 1011 ppd->tp_status = TP_STATUS_AVAILABLE; 1012 } 1013 } 1014 1015 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1016 struct tpacket3_hdr *ppd) 1017 { 1018 ppd->hv1.tp_padding = 0; 1019 prb_fill_vlan_info(pkc, ppd); 1020 1021 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1022 prb_fill_rxhash(pkc, ppd); 1023 else 1024 prb_clear_rxhash(pkc, ppd); 1025 } 1026 1027 static void prb_fill_curr_block(char *curr, 1028 struct tpacket_kbdq_core *pkc, 1029 struct tpacket_block_desc *pbd, 1030 unsigned int len) 1031 { 1032 struct tpacket3_hdr *ppd; 1033 1034 ppd = (struct tpacket3_hdr *)curr; 1035 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1036 pkc->prev = curr; 1037 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1038 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1039 BLOCK_NUM_PKTS(pbd) += 1; 1040 atomic_inc(&pkc->blk_fill_in_prog); 1041 prb_run_all_ft_ops(pkc, ppd); 1042 } 1043 1044 /* Assumes caller has the sk->rx_queue.lock */ 1045 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1046 struct sk_buff *skb, 1047 int status, 1048 unsigned int len 1049 ) 1050 { 1051 struct tpacket_kbdq_core *pkc; 1052 struct tpacket_block_desc *pbd; 1053 char *curr, *end; 1054 1055 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1056 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1057 1058 /* Queue is frozen when user space is lagging behind */ 1059 if (prb_queue_frozen(pkc)) { 1060 /* 1061 * Check if that last block which caused the queue to freeze, 1062 * is still in_use by user-space. 1063 */ 1064 if (prb_curr_blk_in_use(pbd)) { 1065 /* Can't record this packet */ 1066 return NULL; 1067 } else { 1068 /* 1069 * Ok, the block was released by user-space. 1070 * Now let's open that block. 1071 * opening a block also thaws the queue. 1072 * Thawing is a side effect. 1073 */ 1074 prb_open_block(pkc, pbd); 1075 } 1076 } 1077 1078 smp_mb(); 1079 curr = pkc->nxt_offset; 1080 pkc->skb = skb; 1081 end = (char *)pbd + pkc->kblk_size; 1082 1083 /* first try the current block */ 1084 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1085 prb_fill_curr_block(curr, pkc, pbd, len); 1086 return (void *)curr; 1087 } 1088 1089 /* Ok, close the current block */ 1090 prb_retire_current_block(pkc, po, 0); 1091 1092 /* Now, try to dispatch the next block */ 1093 curr = (char *)prb_dispatch_next_block(pkc, po); 1094 if (curr) { 1095 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1096 prb_fill_curr_block(curr, pkc, pbd, len); 1097 return (void *)curr; 1098 } 1099 1100 /* 1101 * No free blocks are available.user_space hasn't caught up yet. 1102 * Queue was just frozen and now this packet will get dropped. 1103 */ 1104 return NULL; 1105 } 1106 1107 static void *packet_current_rx_frame(struct packet_sock *po, 1108 struct sk_buff *skb, 1109 int status, unsigned int len) 1110 { 1111 char *curr = NULL; 1112 switch (po->tp_version) { 1113 case TPACKET_V1: 1114 case TPACKET_V2: 1115 curr = packet_lookup_frame(po, &po->rx_ring, 1116 po->rx_ring.head, status); 1117 return curr; 1118 case TPACKET_V3: 1119 return __packet_lookup_frame_in_block(po, skb, status, len); 1120 default: 1121 WARN(1, "TPACKET version not supported\n"); 1122 BUG(); 1123 return NULL; 1124 } 1125 } 1126 1127 static void *prb_lookup_block(struct packet_sock *po, 1128 struct packet_ring_buffer *rb, 1129 unsigned int idx, 1130 int status) 1131 { 1132 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1133 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1134 1135 if (status != BLOCK_STATUS(pbd)) 1136 return NULL; 1137 return pbd; 1138 } 1139 1140 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1141 { 1142 unsigned int prev; 1143 if (rb->prb_bdqc.kactive_blk_num) 1144 prev = rb->prb_bdqc.kactive_blk_num-1; 1145 else 1146 prev = rb->prb_bdqc.knum_blocks-1; 1147 return prev; 1148 } 1149 1150 /* Assumes caller has held the rx_queue.lock */ 1151 static void *__prb_previous_block(struct packet_sock *po, 1152 struct packet_ring_buffer *rb, 1153 int status) 1154 { 1155 unsigned int previous = prb_previous_blk_num(rb); 1156 return prb_lookup_block(po, rb, previous, status); 1157 } 1158 1159 static void *packet_previous_rx_frame(struct packet_sock *po, 1160 struct packet_ring_buffer *rb, 1161 int status) 1162 { 1163 if (po->tp_version <= TPACKET_V2) 1164 return packet_previous_frame(po, rb, status); 1165 1166 return __prb_previous_block(po, rb, status); 1167 } 1168 1169 static void packet_increment_rx_head(struct packet_sock *po, 1170 struct packet_ring_buffer *rb) 1171 { 1172 switch (po->tp_version) { 1173 case TPACKET_V1: 1174 case TPACKET_V2: 1175 return packet_increment_head(rb); 1176 case TPACKET_V3: 1177 default: 1178 WARN(1, "TPACKET version not supported.\n"); 1179 BUG(); 1180 return; 1181 } 1182 } 1183 1184 static void *packet_previous_frame(struct packet_sock *po, 1185 struct packet_ring_buffer *rb, 1186 int status) 1187 { 1188 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1189 return packet_lookup_frame(po, rb, previous, status); 1190 } 1191 1192 static void packet_increment_head(struct packet_ring_buffer *buff) 1193 { 1194 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1195 } 1196 1197 static void packet_inc_pending(struct packet_ring_buffer *rb) 1198 { 1199 this_cpu_inc(*rb->pending_refcnt); 1200 } 1201 1202 static void packet_dec_pending(struct packet_ring_buffer *rb) 1203 { 1204 this_cpu_dec(*rb->pending_refcnt); 1205 } 1206 1207 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1208 { 1209 unsigned int refcnt = 0; 1210 int cpu; 1211 1212 /* We don't use pending refcount in rx_ring. */ 1213 if (rb->pending_refcnt == NULL) 1214 return 0; 1215 1216 for_each_possible_cpu(cpu) 1217 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1218 1219 return refcnt; 1220 } 1221 1222 static int packet_alloc_pending(struct packet_sock *po) 1223 { 1224 po->rx_ring.pending_refcnt = NULL; 1225 1226 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1227 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1228 return -ENOBUFS; 1229 1230 return 0; 1231 } 1232 1233 static void packet_free_pending(struct packet_sock *po) 1234 { 1235 free_percpu(po->tx_ring.pending_refcnt); 1236 } 1237 1238 #define ROOM_POW_OFF 2 1239 #define ROOM_NONE 0x0 1240 #define ROOM_LOW 0x1 1241 #define ROOM_NORMAL 0x2 1242 1243 static bool __tpacket_has_room(struct packet_sock *po, int pow_off) 1244 { 1245 int idx, len; 1246 1247 len = po->rx_ring.frame_max + 1; 1248 idx = po->rx_ring.head; 1249 if (pow_off) 1250 idx += len >> pow_off; 1251 if (idx >= len) 1252 idx -= len; 1253 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1254 } 1255 1256 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off) 1257 { 1258 int idx, len; 1259 1260 len = po->rx_ring.prb_bdqc.knum_blocks; 1261 idx = po->rx_ring.prb_bdqc.kactive_blk_num; 1262 if (pow_off) 1263 idx += len >> pow_off; 1264 if (idx >= len) 1265 idx -= len; 1266 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1267 } 1268 1269 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1270 { 1271 struct sock *sk = &po->sk; 1272 int ret = ROOM_NONE; 1273 1274 if (po->prot_hook.func != tpacket_rcv) { 1275 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1276 - (skb ? skb->truesize : 0); 1277 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF)) 1278 return ROOM_NORMAL; 1279 else if (avail > 0) 1280 return ROOM_LOW; 1281 else 1282 return ROOM_NONE; 1283 } 1284 1285 if (po->tp_version == TPACKET_V3) { 1286 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1287 ret = ROOM_NORMAL; 1288 else if (__tpacket_v3_has_room(po, 0)) 1289 ret = ROOM_LOW; 1290 } else { 1291 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1292 ret = ROOM_NORMAL; 1293 else if (__tpacket_has_room(po, 0)) 1294 ret = ROOM_LOW; 1295 } 1296 1297 return ret; 1298 } 1299 1300 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1301 { 1302 int ret; 1303 bool has_room; 1304 1305 spin_lock_bh(&po->sk.sk_receive_queue.lock); 1306 ret = __packet_rcv_has_room(po, skb); 1307 has_room = ret == ROOM_NORMAL; 1308 if (po->pressure == has_room) 1309 po->pressure = !has_room; 1310 spin_unlock_bh(&po->sk.sk_receive_queue.lock); 1311 1312 return ret; 1313 } 1314 1315 static void packet_sock_destruct(struct sock *sk) 1316 { 1317 skb_queue_purge(&sk->sk_error_queue); 1318 1319 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1320 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1321 1322 if (!sock_flag(sk, SOCK_DEAD)) { 1323 pr_err("Attempt to release alive packet socket: %p\n", sk); 1324 return; 1325 } 1326 1327 sk_refcnt_debug_dec(sk); 1328 } 1329 1330 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1331 { 1332 u32 rxhash; 1333 int i, count = 0; 1334 1335 rxhash = skb_get_hash(skb); 1336 for (i = 0; i < ROLLOVER_HLEN; i++) 1337 if (po->rollover->history[i] == rxhash) 1338 count++; 1339 1340 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash; 1341 return count > (ROLLOVER_HLEN >> 1); 1342 } 1343 1344 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1345 struct sk_buff *skb, 1346 unsigned int num) 1347 { 1348 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1349 } 1350 1351 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1352 struct sk_buff *skb, 1353 unsigned int num) 1354 { 1355 unsigned int val = atomic_inc_return(&f->rr_cur); 1356 1357 return val % num; 1358 } 1359 1360 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1361 struct sk_buff *skb, 1362 unsigned int num) 1363 { 1364 return smp_processor_id() % num; 1365 } 1366 1367 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1368 struct sk_buff *skb, 1369 unsigned int num) 1370 { 1371 return prandom_u32_max(num); 1372 } 1373 1374 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1375 struct sk_buff *skb, 1376 unsigned int idx, bool try_self, 1377 unsigned int num) 1378 { 1379 struct packet_sock *po, *po_next, *po_skip = NULL; 1380 unsigned int i, j, room = ROOM_NONE; 1381 1382 po = pkt_sk(f->arr[idx]); 1383 1384 if (try_self) { 1385 room = packet_rcv_has_room(po, skb); 1386 if (room == ROOM_NORMAL || 1387 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1388 return idx; 1389 po_skip = po; 1390 } 1391 1392 i = j = min_t(int, po->rollover->sock, num - 1); 1393 do { 1394 po_next = pkt_sk(f->arr[i]); 1395 if (po_next != po_skip && !po_next->pressure && 1396 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1397 if (i != j) 1398 po->rollover->sock = i; 1399 atomic_long_inc(&po->rollover->num); 1400 if (room == ROOM_LOW) 1401 atomic_long_inc(&po->rollover->num_huge); 1402 return i; 1403 } 1404 1405 if (++i == num) 1406 i = 0; 1407 } while (i != j); 1408 1409 atomic_long_inc(&po->rollover->num_failed); 1410 return idx; 1411 } 1412 1413 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1414 struct sk_buff *skb, 1415 unsigned int num) 1416 { 1417 return skb_get_queue_mapping(skb) % num; 1418 } 1419 1420 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1421 struct sk_buff *skb, 1422 unsigned int num) 1423 { 1424 struct bpf_prog *prog; 1425 unsigned int ret = 0; 1426 1427 rcu_read_lock(); 1428 prog = rcu_dereference(f->bpf_prog); 1429 if (prog) 1430 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1431 rcu_read_unlock(); 1432 1433 return ret; 1434 } 1435 1436 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1437 { 1438 return f->flags & (flag >> 8); 1439 } 1440 1441 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1442 struct packet_type *pt, struct net_device *orig_dev) 1443 { 1444 struct packet_fanout *f = pt->af_packet_priv; 1445 unsigned int num = READ_ONCE(f->num_members); 1446 struct net *net = read_pnet(&f->net); 1447 struct packet_sock *po; 1448 unsigned int idx; 1449 1450 if (!net_eq(dev_net(dev), net) || !num) { 1451 kfree_skb(skb); 1452 return 0; 1453 } 1454 1455 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1456 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1457 if (!skb) 1458 return 0; 1459 } 1460 switch (f->type) { 1461 case PACKET_FANOUT_HASH: 1462 default: 1463 idx = fanout_demux_hash(f, skb, num); 1464 break; 1465 case PACKET_FANOUT_LB: 1466 idx = fanout_demux_lb(f, skb, num); 1467 break; 1468 case PACKET_FANOUT_CPU: 1469 idx = fanout_demux_cpu(f, skb, num); 1470 break; 1471 case PACKET_FANOUT_RND: 1472 idx = fanout_demux_rnd(f, skb, num); 1473 break; 1474 case PACKET_FANOUT_QM: 1475 idx = fanout_demux_qm(f, skb, num); 1476 break; 1477 case PACKET_FANOUT_ROLLOVER: 1478 idx = fanout_demux_rollover(f, skb, 0, false, num); 1479 break; 1480 case PACKET_FANOUT_CBPF: 1481 case PACKET_FANOUT_EBPF: 1482 idx = fanout_demux_bpf(f, skb, num); 1483 break; 1484 } 1485 1486 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1487 idx = fanout_demux_rollover(f, skb, idx, true, num); 1488 1489 po = pkt_sk(f->arr[idx]); 1490 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1491 } 1492 1493 DEFINE_MUTEX(fanout_mutex); 1494 EXPORT_SYMBOL_GPL(fanout_mutex); 1495 static LIST_HEAD(fanout_list); 1496 static u16 fanout_next_id; 1497 1498 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1499 { 1500 struct packet_fanout *f = po->fanout; 1501 1502 spin_lock(&f->lock); 1503 f->arr[f->num_members] = sk; 1504 smp_wmb(); 1505 f->num_members++; 1506 if (f->num_members == 1) 1507 dev_add_pack(&f->prot_hook); 1508 spin_unlock(&f->lock); 1509 } 1510 1511 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1512 { 1513 struct packet_fanout *f = po->fanout; 1514 int i; 1515 1516 spin_lock(&f->lock); 1517 for (i = 0; i < f->num_members; i++) { 1518 if (f->arr[i] == sk) 1519 break; 1520 } 1521 BUG_ON(i >= f->num_members); 1522 f->arr[i] = f->arr[f->num_members - 1]; 1523 f->num_members--; 1524 if (f->num_members == 0) 1525 __dev_remove_pack(&f->prot_hook); 1526 spin_unlock(&f->lock); 1527 } 1528 1529 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1530 { 1531 if (sk->sk_family != PF_PACKET) 1532 return false; 1533 1534 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1535 } 1536 1537 static void fanout_init_data(struct packet_fanout *f) 1538 { 1539 switch (f->type) { 1540 case PACKET_FANOUT_LB: 1541 atomic_set(&f->rr_cur, 0); 1542 break; 1543 case PACKET_FANOUT_CBPF: 1544 case PACKET_FANOUT_EBPF: 1545 RCU_INIT_POINTER(f->bpf_prog, NULL); 1546 break; 1547 } 1548 } 1549 1550 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1551 { 1552 struct bpf_prog *old; 1553 1554 spin_lock(&f->lock); 1555 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1556 rcu_assign_pointer(f->bpf_prog, new); 1557 spin_unlock(&f->lock); 1558 1559 if (old) { 1560 synchronize_net(); 1561 bpf_prog_destroy(old); 1562 } 1563 } 1564 1565 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data, 1566 unsigned int len) 1567 { 1568 struct bpf_prog *new; 1569 struct sock_fprog fprog; 1570 int ret; 1571 1572 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1573 return -EPERM; 1574 if (len != sizeof(fprog)) 1575 return -EINVAL; 1576 if (copy_from_user(&fprog, data, len)) 1577 return -EFAULT; 1578 1579 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1580 if (ret) 1581 return ret; 1582 1583 __fanout_set_data_bpf(po->fanout, new); 1584 return 0; 1585 } 1586 1587 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data, 1588 unsigned int len) 1589 { 1590 struct bpf_prog *new; 1591 u32 fd; 1592 1593 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1594 return -EPERM; 1595 if (len != sizeof(fd)) 1596 return -EINVAL; 1597 if (copy_from_user(&fd, data, len)) 1598 return -EFAULT; 1599 1600 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1601 if (IS_ERR(new)) 1602 return PTR_ERR(new); 1603 1604 __fanout_set_data_bpf(po->fanout, new); 1605 return 0; 1606 } 1607 1608 static int fanout_set_data(struct packet_sock *po, char __user *data, 1609 unsigned int len) 1610 { 1611 switch (po->fanout->type) { 1612 case PACKET_FANOUT_CBPF: 1613 return fanout_set_data_cbpf(po, data, len); 1614 case PACKET_FANOUT_EBPF: 1615 return fanout_set_data_ebpf(po, data, len); 1616 default: 1617 return -EINVAL; 1618 }; 1619 } 1620 1621 static void fanout_release_data(struct packet_fanout *f) 1622 { 1623 switch (f->type) { 1624 case PACKET_FANOUT_CBPF: 1625 case PACKET_FANOUT_EBPF: 1626 __fanout_set_data_bpf(f, NULL); 1627 }; 1628 } 1629 1630 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1631 { 1632 struct packet_fanout *f; 1633 1634 list_for_each_entry(f, &fanout_list, list) { 1635 if (f->id == candidate_id && 1636 read_pnet(&f->net) == sock_net(sk)) { 1637 return false; 1638 } 1639 } 1640 return true; 1641 } 1642 1643 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1644 { 1645 u16 id = fanout_next_id; 1646 1647 do { 1648 if (__fanout_id_is_free(sk, id)) { 1649 *new_id = id; 1650 fanout_next_id = id + 1; 1651 return true; 1652 } 1653 1654 id++; 1655 } while (id != fanout_next_id); 1656 1657 return false; 1658 } 1659 1660 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1661 { 1662 struct packet_rollover *rollover = NULL; 1663 struct packet_sock *po = pkt_sk(sk); 1664 struct packet_fanout *f, *match; 1665 u8 type = type_flags & 0xff; 1666 u8 flags = type_flags >> 8; 1667 int err; 1668 1669 switch (type) { 1670 case PACKET_FANOUT_ROLLOVER: 1671 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1672 return -EINVAL; 1673 case PACKET_FANOUT_HASH: 1674 case PACKET_FANOUT_LB: 1675 case PACKET_FANOUT_CPU: 1676 case PACKET_FANOUT_RND: 1677 case PACKET_FANOUT_QM: 1678 case PACKET_FANOUT_CBPF: 1679 case PACKET_FANOUT_EBPF: 1680 break; 1681 default: 1682 return -EINVAL; 1683 } 1684 1685 mutex_lock(&fanout_mutex); 1686 1687 err = -EALREADY; 1688 if (po->fanout) 1689 goto out; 1690 1691 if (type == PACKET_FANOUT_ROLLOVER || 1692 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1693 err = -ENOMEM; 1694 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); 1695 if (!rollover) 1696 goto out; 1697 atomic_long_set(&rollover->num, 0); 1698 atomic_long_set(&rollover->num_huge, 0); 1699 atomic_long_set(&rollover->num_failed, 0); 1700 po->rollover = rollover; 1701 } 1702 1703 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1704 if (id != 0) { 1705 err = -EINVAL; 1706 goto out; 1707 } 1708 if (!fanout_find_new_id(sk, &id)) { 1709 err = -ENOMEM; 1710 goto out; 1711 } 1712 /* ephemeral flag for the first socket in the group: drop it */ 1713 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1714 } 1715 1716 match = NULL; 1717 list_for_each_entry(f, &fanout_list, list) { 1718 if (f->id == id && 1719 read_pnet(&f->net) == sock_net(sk)) { 1720 match = f; 1721 break; 1722 } 1723 } 1724 err = -EINVAL; 1725 if (match && match->flags != flags) 1726 goto out; 1727 if (!match) { 1728 err = -ENOMEM; 1729 match = kzalloc(sizeof(*match), GFP_KERNEL); 1730 if (!match) 1731 goto out; 1732 write_pnet(&match->net, sock_net(sk)); 1733 match->id = id; 1734 match->type = type; 1735 match->flags = flags; 1736 INIT_LIST_HEAD(&match->list); 1737 spin_lock_init(&match->lock); 1738 refcount_set(&match->sk_ref, 0); 1739 fanout_init_data(match); 1740 match->prot_hook.type = po->prot_hook.type; 1741 match->prot_hook.dev = po->prot_hook.dev; 1742 match->prot_hook.func = packet_rcv_fanout; 1743 match->prot_hook.af_packet_priv = match; 1744 match->prot_hook.id_match = match_fanout_group; 1745 list_add(&match->list, &fanout_list); 1746 } 1747 err = -EINVAL; 1748 1749 spin_lock(&po->bind_lock); 1750 if (po->running && 1751 match->type == type && 1752 match->prot_hook.type == po->prot_hook.type && 1753 match->prot_hook.dev == po->prot_hook.dev) { 1754 err = -ENOSPC; 1755 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1756 __dev_remove_pack(&po->prot_hook); 1757 po->fanout = match; 1758 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1759 __fanout_link(sk, po); 1760 err = 0; 1761 } 1762 } 1763 spin_unlock(&po->bind_lock); 1764 1765 if (err && !refcount_read(&match->sk_ref)) { 1766 list_del(&match->list); 1767 kfree(match); 1768 } 1769 1770 out: 1771 if (err && rollover) { 1772 kfree(rollover); 1773 po->rollover = NULL; 1774 } 1775 mutex_unlock(&fanout_mutex); 1776 return err; 1777 } 1778 1779 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1780 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1781 * It is the responsibility of the caller to call fanout_release_data() and 1782 * free the returned packet_fanout (after synchronize_net()) 1783 */ 1784 static struct packet_fanout *fanout_release(struct sock *sk) 1785 { 1786 struct packet_sock *po = pkt_sk(sk); 1787 struct packet_fanout *f; 1788 1789 mutex_lock(&fanout_mutex); 1790 f = po->fanout; 1791 if (f) { 1792 po->fanout = NULL; 1793 1794 if (refcount_dec_and_test(&f->sk_ref)) 1795 list_del(&f->list); 1796 else 1797 f = NULL; 1798 1799 if (po->rollover) 1800 kfree_rcu(po->rollover, rcu); 1801 } 1802 mutex_unlock(&fanout_mutex); 1803 1804 return f; 1805 } 1806 1807 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1808 struct sk_buff *skb) 1809 { 1810 /* Earlier code assumed this would be a VLAN pkt, double-check 1811 * this now that we have the actual packet in hand. We can only 1812 * do this check on Ethernet devices. 1813 */ 1814 if (unlikely(dev->type != ARPHRD_ETHER)) 1815 return false; 1816 1817 skb_reset_mac_header(skb); 1818 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1819 } 1820 1821 static const struct proto_ops packet_ops; 1822 1823 static const struct proto_ops packet_ops_spkt; 1824 1825 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1826 struct packet_type *pt, struct net_device *orig_dev) 1827 { 1828 struct sock *sk; 1829 struct sockaddr_pkt *spkt; 1830 1831 /* 1832 * When we registered the protocol we saved the socket in the data 1833 * field for just this event. 1834 */ 1835 1836 sk = pt->af_packet_priv; 1837 1838 /* 1839 * Yank back the headers [hope the device set this 1840 * right or kerboom...] 1841 * 1842 * Incoming packets have ll header pulled, 1843 * push it back. 1844 * 1845 * For outgoing ones skb->data == skb_mac_header(skb) 1846 * so that this procedure is noop. 1847 */ 1848 1849 if (skb->pkt_type == PACKET_LOOPBACK) 1850 goto out; 1851 1852 if (!net_eq(dev_net(dev), sock_net(sk))) 1853 goto out; 1854 1855 skb = skb_share_check(skb, GFP_ATOMIC); 1856 if (skb == NULL) 1857 goto oom; 1858 1859 /* drop any routing info */ 1860 skb_dst_drop(skb); 1861 1862 /* drop conntrack reference */ 1863 nf_reset(skb); 1864 1865 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1866 1867 skb_push(skb, skb->data - skb_mac_header(skb)); 1868 1869 /* 1870 * The SOCK_PACKET socket receives _all_ frames. 1871 */ 1872 1873 spkt->spkt_family = dev->type; 1874 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1875 spkt->spkt_protocol = skb->protocol; 1876 1877 /* 1878 * Charge the memory to the socket. This is done specifically 1879 * to prevent sockets using all the memory up. 1880 */ 1881 1882 if (sock_queue_rcv_skb(sk, skb) == 0) 1883 return 0; 1884 1885 out: 1886 kfree_skb(skb); 1887 oom: 1888 return 0; 1889 } 1890 1891 1892 /* 1893 * Output a raw packet to a device layer. This bypasses all the other 1894 * protocol layers and you must therefore supply it with a complete frame 1895 */ 1896 1897 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1898 size_t len) 1899 { 1900 struct sock *sk = sock->sk; 1901 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1902 struct sk_buff *skb = NULL; 1903 struct net_device *dev; 1904 struct sockcm_cookie sockc; 1905 __be16 proto = 0; 1906 int err; 1907 int extra_len = 0; 1908 1909 /* 1910 * Get and verify the address. 1911 */ 1912 1913 if (saddr) { 1914 if (msg->msg_namelen < sizeof(struct sockaddr)) 1915 return -EINVAL; 1916 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1917 proto = saddr->spkt_protocol; 1918 } else 1919 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1920 1921 /* 1922 * Find the device first to size check it 1923 */ 1924 1925 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1926 retry: 1927 rcu_read_lock(); 1928 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1929 err = -ENODEV; 1930 if (dev == NULL) 1931 goto out_unlock; 1932 1933 err = -ENETDOWN; 1934 if (!(dev->flags & IFF_UP)) 1935 goto out_unlock; 1936 1937 /* 1938 * You may not queue a frame bigger than the mtu. This is the lowest level 1939 * raw protocol and you must do your own fragmentation at this level. 1940 */ 1941 1942 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1943 if (!netif_supports_nofcs(dev)) { 1944 err = -EPROTONOSUPPORT; 1945 goto out_unlock; 1946 } 1947 extra_len = 4; /* We're doing our own CRC */ 1948 } 1949 1950 err = -EMSGSIZE; 1951 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1952 goto out_unlock; 1953 1954 if (!skb) { 1955 size_t reserved = LL_RESERVED_SPACE(dev); 1956 int tlen = dev->needed_tailroom; 1957 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1958 1959 rcu_read_unlock(); 1960 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1961 if (skb == NULL) 1962 return -ENOBUFS; 1963 /* FIXME: Save some space for broken drivers that write a hard 1964 * header at transmission time by themselves. PPP is the notable 1965 * one here. This should really be fixed at the driver level. 1966 */ 1967 skb_reserve(skb, reserved); 1968 skb_reset_network_header(skb); 1969 1970 /* Try to align data part correctly */ 1971 if (hhlen) { 1972 skb->data -= hhlen; 1973 skb->tail -= hhlen; 1974 if (len < hhlen) 1975 skb_reset_network_header(skb); 1976 } 1977 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1978 if (err) 1979 goto out_free; 1980 goto retry; 1981 } 1982 1983 if (!dev_validate_header(dev, skb->data, len)) { 1984 err = -EINVAL; 1985 goto out_unlock; 1986 } 1987 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 1988 !packet_extra_vlan_len_allowed(dev, skb)) { 1989 err = -EMSGSIZE; 1990 goto out_unlock; 1991 } 1992 1993 sockc.tsflags = sk->sk_tsflags; 1994 if (msg->msg_controllen) { 1995 err = sock_cmsg_send(sk, msg, &sockc); 1996 if (unlikely(err)) 1997 goto out_unlock; 1998 } 1999 2000 skb->protocol = proto; 2001 skb->dev = dev; 2002 skb->priority = sk->sk_priority; 2003 skb->mark = sk->sk_mark; 2004 2005 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags); 2006 2007 if (unlikely(extra_len == 4)) 2008 skb->no_fcs = 1; 2009 2010 skb_probe_transport_header(skb, 0); 2011 2012 dev_queue_xmit(skb); 2013 rcu_read_unlock(); 2014 return len; 2015 2016 out_unlock: 2017 rcu_read_unlock(); 2018 out_free: 2019 kfree_skb(skb); 2020 return err; 2021 } 2022 2023 static unsigned int run_filter(struct sk_buff *skb, 2024 const struct sock *sk, 2025 unsigned int res) 2026 { 2027 struct sk_filter *filter; 2028 2029 rcu_read_lock(); 2030 filter = rcu_dereference(sk->sk_filter); 2031 if (filter != NULL) 2032 res = bpf_prog_run_clear_cb(filter->prog, skb); 2033 rcu_read_unlock(); 2034 2035 return res; 2036 } 2037 2038 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2039 size_t *len) 2040 { 2041 struct virtio_net_hdr vnet_hdr; 2042 2043 if (*len < sizeof(vnet_hdr)) 2044 return -EINVAL; 2045 *len -= sizeof(vnet_hdr); 2046 2047 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true)) 2048 return -EINVAL; 2049 2050 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr)); 2051 } 2052 2053 /* 2054 * This function makes lazy skb cloning in hope that most of packets 2055 * are discarded by BPF. 2056 * 2057 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2058 * and skb->cb are mangled. It works because (and until) packets 2059 * falling here are owned by current CPU. Output packets are cloned 2060 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2061 * sequencially, so that if we return skb to original state on exit, 2062 * we will not harm anyone. 2063 */ 2064 2065 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2066 struct packet_type *pt, struct net_device *orig_dev) 2067 { 2068 struct sock *sk; 2069 struct sockaddr_ll *sll; 2070 struct packet_sock *po; 2071 u8 *skb_head = skb->data; 2072 int skb_len = skb->len; 2073 unsigned int snaplen, res; 2074 bool is_drop_n_account = false; 2075 2076 if (skb->pkt_type == PACKET_LOOPBACK) 2077 goto drop; 2078 2079 sk = pt->af_packet_priv; 2080 po = pkt_sk(sk); 2081 2082 if (!net_eq(dev_net(dev), sock_net(sk))) 2083 goto drop; 2084 2085 skb->dev = dev; 2086 2087 if (dev->header_ops) { 2088 /* The device has an explicit notion of ll header, 2089 * exported to higher levels. 2090 * 2091 * Otherwise, the device hides details of its frame 2092 * structure, so that corresponding packet head is 2093 * never delivered to user. 2094 */ 2095 if (sk->sk_type != SOCK_DGRAM) 2096 skb_push(skb, skb->data - skb_mac_header(skb)); 2097 else if (skb->pkt_type == PACKET_OUTGOING) { 2098 /* Special case: outgoing packets have ll header at head */ 2099 skb_pull(skb, skb_network_offset(skb)); 2100 } 2101 } 2102 2103 snaplen = skb->len; 2104 2105 res = run_filter(skb, sk, snaplen); 2106 if (!res) 2107 goto drop_n_restore; 2108 if (snaplen > res) 2109 snaplen = res; 2110 2111 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2112 goto drop_n_acct; 2113 2114 if (skb_shared(skb)) { 2115 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2116 if (nskb == NULL) 2117 goto drop_n_acct; 2118 2119 if (skb_head != skb->data) { 2120 skb->data = skb_head; 2121 skb->len = skb_len; 2122 } 2123 consume_skb(skb); 2124 skb = nskb; 2125 } 2126 2127 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2128 2129 sll = &PACKET_SKB_CB(skb)->sa.ll; 2130 sll->sll_hatype = dev->type; 2131 sll->sll_pkttype = skb->pkt_type; 2132 if (unlikely(po->origdev)) 2133 sll->sll_ifindex = orig_dev->ifindex; 2134 else 2135 sll->sll_ifindex = dev->ifindex; 2136 2137 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2138 2139 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2140 * Use their space for storing the original skb length. 2141 */ 2142 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2143 2144 if (pskb_trim(skb, snaplen)) 2145 goto drop_n_acct; 2146 2147 skb_set_owner_r(skb, sk); 2148 skb->dev = NULL; 2149 skb_dst_drop(skb); 2150 2151 /* drop conntrack reference */ 2152 nf_reset(skb); 2153 2154 spin_lock(&sk->sk_receive_queue.lock); 2155 po->stats.stats1.tp_packets++; 2156 sock_skb_set_dropcount(sk, skb); 2157 __skb_queue_tail(&sk->sk_receive_queue, skb); 2158 spin_unlock(&sk->sk_receive_queue.lock); 2159 sk->sk_data_ready(sk); 2160 return 0; 2161 2162 drop_n_acct: 2163 is_drop_n_account = true; 2164 spin_lock(&sk->sk_receive_queue.lock); 2165 po->stats.stats1.tp_drops++; 2166 atomic_inc(&sk->sk_drops); 2167 spin_unlock(&sk->sk_receive_queue.lock); 2168 2169 drop_n_restore: 2170 if (skb_head != skb->data && skb_shared(skb)) { 2171 skb->data = skb_head; 2172 skb->len = skb_len; 2173 } 2174 drop: 2175 if (!is_drop_n_account) 2176 consume_skb(skb); 2177 else 2178 kfree_skb(skb); 2179 return 0; 2180 } 2181 2182 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2183 struct packet_type *pt, struct net_device *orig_dev) 2184 { 2185 struct sock *sk; 2186 struct packet_sock *po; 2187 struct sockaddr_ll *sll; 2188 union tpacket_uhdr h; 2189 u8 *skb_head = skb->data; 2190 int skb_len = skb->len; 2191 unsigned int snaplen, res; 2192 unsigned long status = TP_STATUS_USER; 2193 unsigned short macoff, netoff, hdrlen; 2194 struct sk_buff *copy_skb = NULL; 2195 struct timespec ts; 2196 __u32 ts_status; 2197 bool is_drop_n_account = false; 2198 bool do_vnet = false; 2199 2200 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2201 * We may add members to them until current aligned size without forcing 2202 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2203 */ 2204 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2205 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2206 2207 if (skb->pkt_type == PACKET_LOOPBACK) 2208 goto drop; 2209 2210 sk = pt->af_packet_priv; 2211 po = pkt_sk(sk); 2212 2213 if (!net_eq(dev_net(dev), sock_net(sk))) 2214 goto drop; 2215 2216 if (dev->header_ops) { 2217 if (sk->sk_type != SOCK_DGRAM) 2218 skb_push(skb, skb->data - skb_mac_header(skb)); 2219 else if (skb->pkt_type == PACKET_OUTGOING) { 2220 /* Special case: outgoing packets have ll header at head */ 2221 skb_pull(skb, skb_network_offset(skb)); 2222 } 2223 } 2224 2225 snaplen = skb->len; 2226 2227 res = run_filter(skb, sk, snaplen); 2228 if (!res) 2229 goto drop_n_restore; 2230 2231 if (skb->ip_summed == CHECKSUM_PARTIAL) 2232 status |= TP_STATUS_CSUMNOTREADY; 2233 else if (skb->pkt_type != PACKET_OUTGOING && 2234 (skb->ip_summed == CHECKSUM_COMPLETE || 2235 skb_csum_unnecessary(skb))) 2236 status |= TP_STATUS_CSUM_VALID; 2237 2238 if (snaplen > res) 2239 snaplen = res; 2240 2241 if (sk->sk_type == SOCK_DGRAM) { 2242 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2243 po->tp_reserve; 2244 } else { 2245 unsigned int maclen = skb_network_offset(skb); 2246 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2247 (maclen < 16 ? 16 : maclen)) + 2248 po->tp_reserve; 2249 if (po->has_vnet_hdr) { 2250 netoff += sizeof(struct virtio_net_hdr); 2251 do_vnet = true; 2252 } 2253 macoff = netoff - maclen; 2254 } 2255 if (po->tp_version <= TPACKET_V2) { 2256 if (macoff + snaplen > po->rx_ring.frame_size) { 2257 if (po->copy_thresh && 2258 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2259 if (skb_shared(skb)) { 2260 copy_skb = skb_clone(skb, GFP_ATOMIC); 2261 } else { 2262 copy_skb = skb_get(skb); 2263 skb_head = skb->data; 2264 } 2265 if (copy_skb) 2266 skb_set_owner_r(copy_skb, sk); 2267 } 2268 snaplen = po->rx_ring.frame_size - macoff; 2269 if ((int)snaplen < 0) { 2270 snaplen = 0; 2271 do_vnet = false; 2272 } 2273 } 2274 } else if (unlikely(macoff + snaplen > 2275 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2276 u32 nval; 2277 2278 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2279 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2280 snaplen, nval, macoff); 2281 snaplen = nval; 2282 if (unlikely((int)snaplen < 0)) { 2283 snaplen = 0; 2284 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2285 do_vnet = false; 2286 } 2287 } 2288 spin_lock(&sk->sk_receive_queue.lock); 2289 h.raw = packet_current_rx_frame(po, skb, 2290 TP_STATUS_KERNEL, (macoff+snaplen)); 2291 if (!h.raw) 2292 goto drop_n_account; 2293 if (po->tp_version <= TPACKET_V2) { 2294 packet_increment_rx_head(po, &po->rx_ring); 2295 /* 2296 * LOSING will be reported till you read the stats, 2297 * because it's COR - Clear On Read. 2298 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2299 * at packet level. 2300 */ 2301 if (po->stats.stats1.tp_drops) 2302 status |= TP_STATUS_LOSING; 2303 } 2304 po->stats.stats1.tp_packets++; 2305 if (copy_skb) { 2306 status |= TP_STATUS_COPY; 2307 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2308 } 2309 spin_unlock(&sk->sk_receive_queue.lock); 2310 2311 if (do_vnet) { 2312 if (virtio_net_hdr_from_skb(skb, h.raw + macoff - 2313 sizeof(struct virtio_net_hdr), 2314 vio_le(), true)) { 2315 spin_lock(&sk->sk_receive_queue.lock); 2316 goto drop_n_account; 2317 } 2318 } 2319 2320 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2321 2322 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 2323 getnstimeofday(&ts); 2324 2325 status |= ts_status; 2326 2327 switch (po->tp_version) { 2328 case TPACKET_V1: 2329 h.h1->tp_len = skb->len; 2330 h.h1->tp_snaplen = snaplen; 2331 h.h1->tp_mac = macoff; 2332 h.h1->tp_net = netoff; 2333 h.h1->tp_sec = ts.tv_sec; 2334 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2335 hdrlen = sizeof(*h.h1); 2336 break; 2337 case TPACKET_V2: 2338 h.h2->tp_len = skb->len; 2339 h.h2->tp_snaplen = snaplen; 2340 h.h2->tp_mac = macoff; 2341 h.h2->tp_net = netoff; 2342 h.h2->tp_sec = ts.tv_sec; 2343 h.h2->tp_nsec = ts.tv_nsec; 2344 if (skb_vlan_tag_present(skb)) { 2345 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2346 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2347 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2348 } else { 2349 h.h2->tp_vlan_tci = 0; 2350 h.h2->tp_vlan_tpid = 0; 2351 } 2352 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2353 hdrlen = sizeof(*h.h2); 2354 break; 2355 case TPACKET_V3: 2356 /* tp_nxt_offset,vlan are already populated above. 2357 * So DONT clear those fields here 2358 */ 2359 h.h3->tp_status |= status; 2360 h.h3->tp_len = skb->len; 2361 h.h3->tp_snaplen = snaplen; 2362 h.h3->tp_mac = macoff; 2363 h.h3->tp_net = netoff; 2364 h.h3->tp_sec = ts.tv_sec; 2365 h.h3->tp_nsec = ts.tv_nsec; 2366 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2367 hdrlen = sizeof(*h.h3); 2368 break; 2369 default: 2370 BUG(); 2371 } 2372 2373 sll = h.raw + TPACKET_ALIGN(hdrlen); 2374 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2375 sll->sll_family = AF_PACKET; 2376 sll->sll_hatype = dev->type; 2377 sll->sll_protocol = skb->protocol; 2378 sll->sll_pkttype = skb->pkt_type; 2379 if (unlikely(po->origdev)) 2380 sll->sll_ifindex = orig_dev->ifindex; 2381 else 2382 sll->sll_ifindex = dev->ifindex; 2383 2384 smp_mb(); 2385 2386 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2387 if (po->tp_version <= TPACKET_V2) { 2388 u8 *start, *end; 2389 2390 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2391 macoff + snaplen); 2392 2393 for (start = h.raw; start < end; start += PAGE_SIZE) 2394 flush_dcache_page(pgv_to_page(start)); 2395 } 2396 smp_wmb(); 2397 #endif 2398 2399 if (po->tp_version <= TPACKET_V2) { 2400 __packet_set_status(po, h.raw, status); 2401 sk->sk_data_ready(sk); 2402 } else { 2403 prb_clear_blk_fill_status(&po->rx_ring); 2404 } 2405 2406 drop_n_restore: 2407 if (skb_head != skb->data && skb_shared(skb)) { 2408 skb->data = skb_head; 2409 skb->len = skb_len; 2410 } 2411 drop: 2412 if (!is_drop_n_account) 2413 consume_skb(skb); 2414 else 2415 kfree_skb(skb); 2416 return 0; 2417 2418 drop_n_account: 2419 is_drop_n_account = true; 2420 po->stats.stats1.tp_drops++; 2421 spin_unlock(&sk->sk_receive_queue.lock); 2422 2423 sk->sk_data_ready(sk); 2424 kfree_skb(copy_skb); 2425 goto drop_n_restore; 2426 } 2427 2428 static void tpacket_destruct_skb(struct sk_buff *skb) 2429 { 2430 struct packet_sock *po = pkt_sk(skb->sk); 2431 2432 if (likely(po->tx_ring.pg_vec)) { 2433 void *ph; 2434 __u32 ts; 2435 2436 ph = skb_shinfo(skb)->destructor_arg; 2437 packet_dec_pending(&po->tx_ring); 2438 2439 ts = __packet_set_timestamp(po, ph, skb); 2440 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2441 } 2442 2443 sock_wfree(skb); 2444 } 2445 2446 static void tpacket_set_protocol(const struct net_device *dev, 2447 struct sk_buff *skb) 2448 { 2449 if (dev->type == ARPHRD_ETHER) { 2450 skb_reset_mac_header(skb); 2451 skb->protocol = eth_hdr(skb)->h_proto; 2452 } 2453 } 2454 2455 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2456 { 2457 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2458 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2459 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2460 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2461 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2462 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2463 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2464 2465 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2466 return -EINVAL; 2467 2468 return 0; 2469 } 2470 2471 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2472 struct virtio_net_hdr *vnet_hdr) 2473 { 2474 if (*len < sizeof(*vnet_hdr)) 2475 return -EINVAL; 2476 *len -= sizeof(*vnet_hdr); 2477 2478 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2479 return -EFAULT; 2480 2481 return __packet_snd_vnet_parse(vnet_hdr, *len); 2482 } 2483 2484 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2485 void *frame, struct net_device *dev, void *data, int tp_len, 2486 __be16 proto, unsigned char *addr, int hlen, int copylen, 2487 const struct sockcm_cookie *sockc) 2488 { 2489 union tpacket_uhdr ph; 2490 int to_write, offset, len, nr_frags, len_max; 2491 struct socket *sock = po->sk.sk_socket; 2492 struct page *page; 2493 int err; 2494 2495 ph.raw = frame; 2496 2497 skb->protocol = proto; 2498 skb->dev = dev; 2499 skb->priority = po->sk.sk_priority; 2500 skb->mark = po->sk.sk_mark; 2501 sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags); 2502 skb_shinfo(skb)->destructor_arg = ph.raw; 2503 2504 skb_reserve(skb, hlen); 2505 skb_reset_network_header(skb); 2506 2507 to_write = tp_len; 2508 2509 if (sock->type == SOCK_DGRAM) { 2510 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2511 NULL, tp_len); 2512 if (unlikely(err < 0)) 2513 return -EINVAL; 2514 } else if (copylen) { 2515 int hdrlen = min_t(int, copylen, tp_len); 2516 2517 skb_push(skb, dev->hard_header_len); 2518 skb_put(skb, copylen - dev->hard_header_len); 2519 err = skb_store_bits(skb, 0, data, hdrlen); 2520 if (unlikely(err)) 2521 return err; 2522 if (!dev_validate_header(dev, skb->data, hdrlen)) 2523 return -EINVAL; 2524 if (!skb->protocol) 2525 tpacket_set_protocol(dev, skb); 2526 2527 data += hdrlen; 2528 to_write -= hdrlen; 2529 } 2530 2531 offset = offset_in_page(data); 2532 len_max = PAGE_SIZE - offset; 2533 len = ((to_write > len_max) ? len_max : to_write); 2534 2535 skb->data_len = to_write; 2536 skb->len += to_write; 2537 skb->truesize += to_write; 2538 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2539 2540 while (likely(to_write)) { 2541 nr_frags = skb_shinfo(skb)->nr_frags; 2542 2543 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2544 pr_err("Packet exceed the number of skb frags(%lu)\n", 2545 MAX_SKB_FRAGS); 2546 return -EFAULT; 2547 } 2548 2549 page = pgv_to_page(data); 2550 data += len; 2551 flush_dcache_page(page); 2552 get_page(page); 2553 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2554 to_write -= len; 2555 offset = 0; 2556 len_max = PAGE_SIZE; 2557 len = ((to_write > len_max) ? len_max : to_write); 2558 } 2559 2560 skb_probe_transport_header(skb, 0); 2561 2562 return tp_len; 2563 } 2564 2565 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2566 int size_max, void **data) 2567 { 2568 union tpacket_uhdr ph; 2569 int tp_len, off; 2570 2571 ph.raw = frame; 2572 2573 switch (po->tp_version) { 2574 case TPACKET_V3: 2575 if (ph.h3->tp_next_offset != 0) { 2576 pr_warn_once("variable sized slot not supported"); 2577 return -EINVAL; 2578 } 2579 tp_len = ph.h3->tp_len; 2580 break; 2581 case TPACKET_V2: 2582 tp_len = ph.h2->tp_len; 2583 break; 2584 default: 2585 tp_len = ph.h1->tp_len; 2586 break; 2587 } 2588 if (unlikely(tp_len > size_max)) { 2589 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2590 return -EMSGSIZE; 2591 } 2592 2593 if (unlikely(po->tp_tx_has_off)) { 2594 int off_min, off_max; 2595 2596 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2597 off_max = po->tx_ring.frame_size - tp_len; 2598 if (po->sk.sk_type == SOCK_DGRAM) { 2599 switch (po->tp_version) { 2600 case TPACKET_V3: 2601 off = ph.h3->tp_net; 2602 break; 2603 case TPACKET_V2: 2604 off = ph.h2->tp_net; 2605 break; 2606 default: 2607 off = ph.h1->tp_net; 2608 break; 2609 } 2610 } else { 2611 switch (po->tp_version) { 2612 case TPACKET_V3: 2613 off = ph.h3->tp_mac; 2614 break; 2615 case TPACKET_V2: 2616 off = ph.h2->tp_mac; 2617 break; 2618 default: 2619 off = ph.h1->tp_mac; 2620 break; 2621 } 2622 } 2623 if (unlikely((off < off_min) || (off_max < off))) 2624 return -EINVAL; 2625 } else { 2626 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2627 } 2628 2629 *data = frame + off; 2630 return tp_len; 2631 } 2632 2633 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2634 { 2635 struct sk_buff *skb; 2636 struct net_device *dev; 2637 struct virtio_net_hdr *vnet_hdr = NULL; 2638 struct sockcm_cookie sockc; 2639 __be16 proto; 2640 int err, reserve = 0; 2641 void *ph; 2642 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2643 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2644 int tp_len, size_max; 2645 unsigned char *addr; 2646 void *data; 2647 int len_sum = 0; 2648 int status = TP_STATUS_AVAILABLE; 2649 int hlen, tlen, copylen = 0; 2650 2651 mutex_lock(&po->pg_vec_lock); 2652 2653 if (likely(saddr == NULL)) { 2654 dev = packet_cached_dev_get(po); 2655 proto = po->num; 2656 addr = NULL; 2657 } else { 2658 err = -EINVAL; 2659 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2660 goto out; 2661 if (msg->msg_namelen < (saddr->sll_halen 2662 + offsetof(struct sockaddr_ll, 2663 sll_addr))) 2664 goto out; 2665 proto = saddr->sll_protocol; 2666 addr = saddr->sll_addr; 2667 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2668 } 2669 2670 err = -ENXIO; 2671 if (unlikely(dev == NULL)) 2672 goto out; 2673 err = -ENETDOWN; 2674 if (unlikely(!(dev->flags & IFF_UP))) 2675 goto out_put; 2676 2677 sockc.tsflags = po->sk.sk_tsflags; 2678 if (msg->msg_controllen) { 2679 err = sock_cmsg_send(&po->sk, msg, &sockc); 2680 if (unlikely(err)) 2681 goto out_put; 2682 } 2683 2684 if (po->sk.sk_socket->type == SOCK_RAW) 2685 reserve = dev->hard_header_len; 2686 size_max = po->tx_ring.frame_size 2687 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2688 2689 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr) 2690 size_max = dev->mtu + reserve + VLAN_HLEN; 2691 2692 do { 2693 ph = packet_current_frame(po, &po->tx_ring, 2694 TP_STATUS_SEND_REQUEST); 2695 if (unlikely(ph == NULL)) { 2696 if (need_wait && need_resched()) 2697 schedule(); 2698 continue; 2699 } 2700 2701 skb = NULL; 2702 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2703 if (tp_len < 0) 2704 goto tpacket_error; 2705 2706 status = TP_STATUS_SEND_REQUEST; 2707 hlen = LL_RESERVED_SPACE(dev); 2708 tlen = dev->needed_tailroom; 2709 if (po->has_vnet_hdr) { 2710 vnet_hdr = data; 2711 data += sizeof(*vnet_hdr); 2712 tp_len -= sizeof(*vnet_hdr); 2713 if (tp_len < 0 || 2714 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2715 tp_len = -EINVAL; 2716 goto tpacket_error; 2717 } 2718 copylen = __virtio16_to_cpu(vio_le(), 2719 vnet_hdr->hdr_len); 2720 } 2721 copylen = max_t(int, copylen, dev->hard_header_len); 2722 skb = sock_alloc_send_skb(&po->sk, 2723 hlen + tlen + sizeof(struct sockaddr_ll) + 2724 (copylen - dev->hard_header_len), 2725 !need_wait, &err); 2726 2727 if (unlikely(skb == NULL)) { 2728 /* we assume the socket was initially writeable ... */ 2729 if (likely(len_sum > 0)) 2730 err = len_sum; 2731 goto out_status; 2732 } 2733 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2734 addr, hlen, copylen, &sockc); 2735 if (likely(tp_len >= 0) && 2736 tp_len > dev->mtu + reserve && 2737 !po->has_vnet_hdr && 2738 !packet_extra_vlan_len_allowed(dev, skb)) 2739 tp_len = -EMSGSIZE; 2740 2741 if (unlikely(tp_len < 0)) { 2742 tpacket_error: 2743 if (po->tp_loss) { 2744 __packet_set_status(po, ph, 2745 TP_STATUS_AVAILABLE); 2746 packet_increment_head(&po->tx_ring); 2747 kfree_skb(skb); 2748 continue; 2749 } else { 2750 status = TP_STATUS_WRONG_FORMAT; 2751 err = tp_len; 2752 goto out_status; 2753 } 2754 } 2755 2756 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr, 2757 vio_le())) { 2758 tp_len = -EINVAL; 2759 goto tpacket_error; 2760 } 2761 2762 skb->destructor = tpacket_destruct_skb; 2763 __packet_set_status(po, ph, TP_STATUS_SENDING); 2764 packet_inc_pending(&po->tx_ring); 2765 2766 status = TP_STATUS_SEND_REQUEST; 2767 err = po->xmit(skb); 2768 if (unlikely(err > 0)) { 2769 err = net_xmit_errno(err); 2770 if (err && __packet_get_status(po, ph) == 2771 TP_STATUS_AVAILABLE) { 2772 /* skb was destructed already */ 2773 skb = NULL; 2774 goto out_status; 2775 } 2776 /* 2777 * skb was dropped but not destructed yet; 2778 * let's treat it like congestion or err < 0 2779 */ 2780 err = 0; 2781 } 2782 packet_increment_head(&po->tx_ring); 2783 len_sum += tp_len; 2784 } while (likely((ph != NULL) || 2785 /* Note: packet_read_pending() might be slow if we have 2786 * to call it as it's per_cpu variable, but in fast-path 2787 * we already short-circuit the loop with the first 2788 * condition, and luckily don't have to go that path 2789 * anyway. 2790 */ 2791 (need_wait && packet_read_pending(&po->tx_ring)))); 2792 2793 err = len_sum; 2794 goto out_put; 2795 2796 out_status: 2797 __packet_set_status(po, ph, status); 2798 kfree_skb(skb); 2799 out_put: 2800 dev_put(dev); 2801 out: 2802 mutex_unlock(&po->pg_vec_lock); 2803 return err; 2804 } 2805 2806 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2807 size_t reserve, size_t len, 2808 size_t linear, int noblock, 2809 int *err) 2810 { 2811 struct sk_buff *skb; 2812 2813 /* Under a page? Don't bother with paged skb. */ 2814 if (prepad + len < PAGE_SIZE || !linear) 2815 linear = len; 2816 2817 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2818 err, 0); 2819 if (!skb) 2820 return NULL; 2821 2822 skb_reserve(skb, reserve); 2823 skb_put(skb, linear); 2824 skb->data_len = len - linear; 2825 skb->len += len - linear; 2826 2827 return skb; 2828 } 2829 2830 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2831 { 2832 struct sock *sk = sock->sk; 2833 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2834 struct sk_buff *skb; 2835 struct net_device *dev; 2836 __be16 proto; 2837 unsigned char *addr; 2838 int err, reserve = 0; 2839 struct sockcm_cookie sockc; 2840 struct virtio_net_hdr vnet_hdr = { 0 }; 2841 int offset = 0; 2842 struct packet_sock *po = pkt_sk(sk); 2843 bool has_vnet_hdr = false; 2844 int hlen, tlen, linear; 2845 int extra_len = 0; 2846 2847 /* 2848 * Get and verify the address. 2849 */ 2850 2851 if (likely(saddr == NULL)) { 2852 dev = packet_cached_dev_get(po); 2853 proto = po->num; 2854 addr = NULL; 2855 } else { 2856 err = -EINVAL; 2857 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2858 goto out; 2859 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2860 goto out; 2861 proto = saddr->sll_protocol; 2862 addr = saddr->sll_addr; 2863 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2864 } 2865 2866 err = -ENXIO; 2867 if (unlikely(dev == NULL)) 2868 goto out_unlock; 2869 err = -ENETDOWN; 2870 if (unlikely(!(dev->flags & IFF_UP))) 2871 goto out_unlock; 2872 2873 sockc.tsflags = sk->sk_tsflags; 2874 sockc.mark = sk->sk_mark; 2875 if (msg->msg_controllen) { 2876 err = sock_cmsg_send(sk, msg, &sockc); 2877 if (unlikely(err)) 2878 goto out_unlock; 2879 } 2880 2881 if (sock->type == SOCK_RAW) 2882 reserve = dev->hard_header_len; 2883 if (po->has_vnet_hdr) { 2884 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); 2885 if (err) 2886 goto out_unlock; 2887 has_vnet_hdr = true; 2888 } 2889 2890 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2891 if (!netif_supports_nofcs(dev)) { 2892 err = -EPROTONOSUPPORT; 2893 goto out_unlock; 2894 } 2895 extra_len = 4; /* We're doing our own CRC */ 2896 } 2897 2898 err = -EMSGSIZE; 2899 if (!vnet_hdr.gso_type && 2900 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2901 goto out_unlock; 2902 2903 err = -ENOBUFS; 2904 hlen = LL_RESERVED_SPACE(dev); 2905 tlen = dev->needed_tailroom; 2906 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 2907 linear = max(linear, min_t(int, len, dev->hard_header_len)); 2908 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 2909 msg->msg_flags & MSG_DONTWAIT, &err); 2910 if (skb == NULL) 2911 goto out_unlock; 2912 2913 skb_set_network_header(skb, reserve); 2914 2915 err = -EINVAL; 2916 if (sock->type == SOCK_DGRAM) { 2917 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2918 if (unlikely(offset < 0)) 2919 goto out_free; 2920 } 2921 2922 /* Returns -EFAULT on error */ 2923 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2924 if (err) 2925 goto out_free; 2926 2927 if (sock->type == SOCK_RAW && 2928 !dev_validate_header(dev, skb->data, len)) { 2929 err = -EINVAL; 2930 goto out_free; 2931 } 2932 2933 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags); 2934 2935 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 2936 !packet_extra_vlan_len_allowed(dev, skb)) { 2937 err = -EMSGSIZE; 2938 goto out_free; 2939 } 2940 2941 skb->protocol = proto; 2942 skb->dev = dev; 2943 skb->priority = sk->sk_priority; 2944 skb->mark = sockc.mark; 2945 2946 if (has_vnet_hdr) { 2947 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 2948 if (err) 2949 goto out_free; 2950 len += sizeof(vnet_hdr); 2951 } 2952 2953 skb_probe_transport_header(skb, reserve); 2954 2955 if (unlikely(extra_len == 4)) 2956 skb->no_fcs = 1; 2957 2958 err = po->xmit(skb); 2959 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2960 goto out_unlock; 2961 2962 dev_put(dev); 2963 2964 return len; 2965 2966 out_free: 2967 kfree_skb(skb); 2968 out_unlock: 2969 if (dev) 2970 dev_put(dev); 2971 out: 2972 return err; 2973 } 2974 2975 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 2976 { 2977 struct sock *sk = sock->sk; 2978 struct packet_sock *po = pkt_sk(sk); 2979 2980 if (po->tx_ring.pg_vec) 2981 return tpacket_snd(po, msg); 2982 else 2983 return packet_snd(sock, msg, len); 2984 } 2985 2986 /* 2987 * Close a PACKET socket. This is fairly simple. We immediately go 2988 * to 'closed' state and remove our protocol entry in the device list. 2989 */ 2990 2991 static int packet_release(struct socket *sock) 2992 { 2993 struct sock *sk = sock->sk; 2994 struct packet_sock *po; 2995 struct packet_fanout *f; 2996 struct net *net; 2997 union tpacket_req_u req_u; 2998 2999 if (!sk) 3000 return 0; 3001 3002 net = sock_net(sk); 3003 po = pkt_sk(sk); 3004 3005 mutex_lock(&net->packet.sklist_lock); 3006 sk_del_node_init_rcu(sk); 3007 mutex_unlock(&net->packet.sklist_lock); 3008 3009 preempt_disable(); 3010 sock_prot_inuse_add(net, sk->sk_prot, -1); 3011 preempt_enable(); 3012 3013 spin_lock(&po->bind_lock); 3014 unregister_prot_hook(sk, false); 3015 packet_cached_dev_reset(po); 3016 3017 if (po->prot_hook.dev) { 3018 dev_put(po->prot_hook.dev); 3019 po->prot_hook.dev = NULL; 3020 } 3021 spin_unlock(&po->bind_lock); 3022 3023 packet_flush_mclist(sk); 3024 3025 if (po->rx_ring.pg_vec) { 3026 memset(&req_u, 0, sizeof(req_u)); 3027 packet_set_ring(sk, &req_u, 1, 0); 3028 } 3029 3030 if (po->tx_ring.pg_vec) { 3031 memset(&req_u, 0, sizeof(req_u)); 3032 packet_set_ring(sk, &req_u, 1, 1); 3033 } 3034 3035 f = fanout_release(sk); 3036 3037 synchronize_net(); 3038 3039 if (f) { 3040 fanout_release_data(f); 3041 kfree(f); 3042 } 3043 /* 3044 * Now the socket is dead. No more input will appear. 3045 */ 3046 sock_orphan(sk); 3047 sock->sk = NULL; 3048 3049 /* Purge queues */ 3050 3051 skb_queue_purge(&sk->sk_receive_queue); 3052 packet_free_pending(po); 3053 sk_refcnt_debug_release(sk); 3054 3055 sock_put(sk); 3056 return 0; 3057 } 3058 3059 /* 3060 * Attach a packet hook. 3061 */ 3062 3063 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3064 __be16 proto) 3065 { 3066 struct packet_sock *po = pkt_sk(sk); 3067 struct net_device *dev_curr; 3068 __be16 proto_curr; 3069 bool need_rehook; 3070 struct net_device *dev = NULL; 3071 int ret = 0; 3072 bool unlisted = false; 3073 3074 lock_sock(sk); 3075 spin_lock(&po->bind_lock); 3076 rcu_read_lock(); 3077 3078 if (po->fanout) { 3079 ret = -EINVAL; 3080 goto out_unlock; 3081 } 3082 3083 if (name) { 3084 dev = dev_get_by_name_rcu(sock_net(sk), name); 3085 if (!dev) { 3086 ret = -ENODEV; 3087 goto out_unlock; 3088 } 3089 } else if (ifindex) { 3090 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3091 if (!dev) { 3092 ret = -ENODEV; 3093 goto out_unlock; 3094 } 3095 } 3096 3097 if (dev) 3098 dev_hold(dev); 3099 3100 proto_curr = po->prot_hook.type; 3101 dev_curr = po->prot_hook.dev; 3102 3103 need_rehook = proto_curr != proto || dev_curr != dev; 3104 3105 if (need_rehook) { 3106 if (po->running) { 3107 rcu_read_unlock(); 3108 __unregister_prot_hook(sk, true); 3109 rcu_read_lock(); 3110 dev_curr = po->prot_hook.dev; 3111 if (dev) 3112 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3113 dev->ifindex); 3114 } 3115 3116 po->num = proto; 3117 po->prot_hook.type = proto; 3118 3119 if (unlikely(unlisted)) { 3120 dev_put(dev); 3121 po->prot_hook.dev = NULL; 3122 po->ifindex = -1; 3123 packet_cached_dev_reset(po); 3124 } else { 3125 po->prot_hook.dev = dev; 3126 po->ifindex = dev ? dev->ifindex : 0; 3127 packet_cached_dev_assign(po, dev); 3128 } 3129 } 3130 if (dev_curr) 3131 dev_put(dev_curr); 3132 3133 if (proto == 0 || !need_rehook) 3134 goto out_unlock; 3135 3136 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3137 register_prot_hook(sk); 3138 } else { 3139 sk->sk_err = ENETDOWN; 3140 if (!sock_flag(sk, SOCK_DEAD)) 3141 sk->sk_error_report(sk); 3142 } 3143 3144 out_unlock: 3145 rcu_read_unlock(); 3146 spin_unlock(&po->bind_lock); 3147 release_sock(sk); 3148 return ret; 3149 } 3150 3151 /* 3152 * Bind a packet socket to a device 3153 */ 3154 3155 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3156 int addr_len) 3157 { 3158 struct sock *sk = sock->sk; 3159 char name[sizeof(uaddr->sa_data) + 1]; 3160 3161 /* 3162 * Check legality 3163 */ 3164 3165 if (addr_len != sizeof(struct sockaddr)) 3166 return -EINVAL; 3167 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3168 * zero-terminated. 3169 */ 3170 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data)); 3171 name[sizeof(uaddr->sa_data)] = 0; 3172 3173 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); 3174 } 3175 3176 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3177 { 3178 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3179 struct sock *sk = sock->sk; 3180 3181 /* 3182 * Check legality 3183 */ 3184 3185 if (addr_len < sizeof(struct sockaddr_ll)) 3186 return -EINVAL; 3187 if (sll->sll_family != AF_PACKET) 3188 return -EINVAL; 3189 3190 return packet_do_bind(sk, NULL, sll->sll_ifindex, 3191 sll->sll_protocol ? : pkt_sk(sk)->num); 3192 } 3193 3194 static struct proto packet_proto = { 3195 .name = "PACKET", 3196 .owner = THIS_MODULE, 3197 .obj_size = sizeof(struct packet_sock), 3198 }; 3199 3200 /* 3201 * Create a packet of type SOCK_PACKET. 3202 */ 3203 3204 static int packet_create(struct net *net, struct socket *sock, int protocol, 3205 int kern) 3206 { 3207 struct sock *sk; 3208 struct packet_sock *po; 3209 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3210 int err; 3211 3212 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3213 return -EPERM; 3214 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3215 sock->type != SOCK_PACKET) 3216 return -ESOCKTNOSUPPORT; 3217 3218 sock->state = SS_UNCONNECTED; 3219 3220 err = -ENOBUFS; 3221 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3222 if (sk == NULL) 3223 goto out; 3224 3225 sock->ops = &packet_ops; 3226 if (sock->type == SOCK_PACKET) 3227 sock->ops = &packet_ops_spkt; 3228 3229 sock_init_data(sock, sk); 3230 3231 po = pkt_sk(sk); 3232 sk->sk_family = PF_PACKET; 3233 po->num = proto; 3234 po->xmit = dev_queue_xmit; 3235 3236 err = packet_alloc_pending(po); 3237 if (err) 3238 goto out2; 3239 3240 packet_cached_dev_reset(po); 3241 3242 sk->sk_destruct = packet_sock_destruct; 3243 sk_refcnt_debug_inc(sk); 3244 3245 /* 3246 * Attach a protocol block 3247 */ 3248 3249 spin_lock_init(&po->bind_lock); 3250 mutex_init(&po->pg_vec_lock); 3251 po->rollover = NULL; 3252 po->prot_hook.func = packet_rcv; 3253 3254 if (sock->type == SOCK_PACKET) 3255 po->prot_hook.func = packet_rcv_spkt; 3256 3257 po->prot_hook.af_packet_priv = sk; 3258 3259 if (proto) { 3260 po->prot_hook.type = proto; 3261 register_prot_hook(sk); 3262 } 3263 3264 mutex_lock(&net->packet.sklist_lock); 3265 sk_add_node_rcu(sk, &net->packet.sklist); 3266 mutex_unlock(&net->packet.sklist_lock); 3267 3268 preempt_disable(); 3269 sock_prot_inuse_add(net, &packet_proto, 1); 3270 preempt_enable(); 3271 3272 return 0; 3273 out2: 3274 sk_free(sk); 3275 out: 3276 return err; 3277 } 3278 3279 /* 3280 * Pull a packet from our receive queue and hand it to the user. 3281 * If necessary we block. 3282 */ 3283 3284 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3285 int flags) 3286 { 3287 struct sock *sk = sock->sk; 3288 struct sk_buff *skb; 3289 int copied, err; 3290 int vnet_hdr_len = 0; 3291 unsigned int origlen = 0; 3292 3293 err = -EINVAL; 3294 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3295 goto out; 3296 3297 #if 0 3298 /* What error should we return now? EUNATTACH? */ 3299 if (pkt_sk(sk)->ifindex < 0) 3300 return -ENODEV; 3301 #endif 3302 3303 if (flags & MSG_ERRQUEUE) { 3304 err = sock_recv_errqueue(sk, msg, len, 3305 SOL_PACKET, PACKET_TX_TIMESTAMP); 3306 goto out; 3307 } 3308 3309 /* 3310 * Call the generic datagram receiver. This handles all sorts 3311 * of horrible races and re-entrancy so we can forget about it 3312 * in the protocol layers. 3313 * 3314 * Now it will return ENETDOWN, if device have just gone down, 3315 * but then it will block. 3316 */ 3317 3318 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3319 3320 /* 3321 * An error occurred so return it. Because skb_recv_datagram() 3322 * handles the blocking we don't see and worry about blocking 3323 * retries. 3324 */ 3325 3326 if (skb == NULL) 3327 goto out; 3328 3329 if (pkt_sk(sk)->pressure) 3330 packet_rcv_has_room(pkt_sk(sk), NULL); 3331 3332 if (pkt_sk(sk)->has_vnet_hdr) { 3333 err = packet_rcv_vnet(msg, skb, &len); 3334 if (err) 3335 goto out_free; 3336 vnet_hdr_len = sizeof(struct virtio_net_hdr); 3337 } 3338 3339 /* You lose any data beyond the buffer you gave. If it worries 3340 * a user program they can ask the device for its MTU 3341 * anyway. 3342 */ 3343 copied = skb->len; 3344 if (copied > len) { 3345 copied = len; 3346 msg->msg_flags |= MSG_TRUNC; 3347 } 3348 3349 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3350 if (err) 3351 goto out_free; 3352 3353 if (sock->type != SOCK_PACKET) { 3354 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3355 3356 /* Original length was stored in sockaddr_ll fields */ 3357 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3358 sll->sll_family = AF_PACKET; 3359 sll->sll_protocol = skb->protocol; 3360 } 3361 3362 sock_recv_ts_and_drops(msg, sk, skb); 3363 3364 if (msg->msg_name) { 3365 /* If the address length field is there to be filled 3366 * in, we fill it in now. 3367 */ 3368 if (sock->type == SOCK_PACKET) { 3369 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3370 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3371 } else { 3372 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3373 3374 msg->msg_namelen = sll->sll_halen + 3375 offsetof(struct sockaddr_ll, sll_addr); 3376 } 3377 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 3378 msg->msg_namelen); 3379 } 3380 3381 if (pkt_sk(sk)->auxdata) { 3382 struct tpacket_auxdata aux; 3383 3384 aux.tp_status = TP_STATUS_USER; 3385 if (skb->ip_summed == CHECKSUM_PARTIAL) 3386 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3387 else if (skb->pkt_type != PACKET_OUTGOING && 3388 (skb->ip_summed == CHECKSUM_COMPLETE || 3389 skb_csum_unnecessary(skb))) 3390 aux.tp_status |= TP_STATUS_CSUM_VALID; 3391 3392 aux.tp_len = origlen; 3393 aux.tp_snaplen = skb->len; 3394 aux.tp_mac = 0; 3395 aux.tp_net = skb_network_offset(skb); 3396 if (skb_vlan_tag_present(skb)) { 3397 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3398 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3399 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3400 } else { 3401 aux.tp_vlan_tci = 0; 3402 aux.tp_vlan_tpid = 0; 3403 } 3404 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3405 } 3406 3407 /* 3408 * Free or return the buffer as appropriate. Again this 3409 * hides all the races and re-entrancy issues from us. 3410 */ 3411 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3412 3413 out_free: 3414 skb_free_datagram(sk, skb); 3415 out: 3416 return err; 3417 } 3418 3419 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3420 int *uaddr_len, int peer) 3421 { 3422 struct net_device *dev; 3423 struct sock *sk = sock->sk; 3424 3425 if (peer) 3426 return -EOPNOTSUPP; 3427 3428 uaddr->sa_family = AF_PACKET; 3429 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3430 rcu_read_lock(); 3431 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3432 if (dev) 3433 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3434 rcu_read_unlock(); 3435 *uaddr_len = sizeof(*uaddr); 3436 3437 return 0; 3438 } 3439 3440 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3441 int *uaddr_len, int peer) 3442 { 3443 struct net_device *dev; 3444 struct sock *sk = sock->sk; 3445 struct packet_sock *po = pkt_sk(sk); 3446 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3447 3448 if (peer) 3449 return -EOPNOTSUPP; 3450 3451 sll->sll_family = AF_PACKET; 3452 sll->sll_ifindex = po->ifindex; 3453 sll->sll_protocol = po->num; 3454 sll->sll_pkttype = 0; 3455 rcu_read_lock(); 3456 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3457 if (dev) { 3458 sll->sll_hatype = dev->type; 3459 sll->sll_halen = dev->addr_len; 3460 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3461 } else { 3462 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3463 sll->sll_halen = 0; 3464 } 3465 rcu_read_unlock(); 3466 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3467 3468 return 0; 3469 } 3470 3471 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3472 int what) 3473 { 3474 switch (i->type) { 3475 case PACKET_MR_MULTICAST: 3476 if (i->alen != dev->addr_len) 3477 return -EINVAL; 3478 if (what > 0) 3479 return dev_mc_add(dev, i->addr); 3480 else 3481 return dev_mc_del(dev, i->addr); 3482 break; 3483 case PACKET_MR_PROMISC: 3484 return dev_set_promiscuity(dev, what); 3485 case PACKET_MR_ALLMULTI: 3486 return dev_set_allmulti(dev, what); 3487 case PACKET_MR_UNICAST: 3488 if (i->alen != dev->addr_len) 3489 return -EINVAL; 3490 if (what > 0) 3491 return dev_uc_add(dev, i->addr); 3492 else 3493 return dev_uc_del(dev, i->addr); 3494 break; 3495 default: 3496 break; 3497 } 3498 return 0; 3499 } 3500 3501 static void packet_dev_mclist_delete(struct net_device *dev, 3502 struct packet_mclist **mlp) 3503 { 3504 struct packet_mclist *ml; 3505 3506 while ((ml = *mlp) != NULL) { 3507 if (ml->ifindex == dev->ifindex) { 3508 packet_dev_mc(dev, ml, -1); 3509 *mlp = ml->next; 3510 kfree(ml); 3511 } else 3512 mlp = &ml->next; 3513 } 3514 } 3515 3516 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3517 { 3518 struct packet_sock *po = pkt_sk(sk); 3519 struct packet_mclist *ml, *i; 3520 struct net_device *dev; 3521 int err; 3522 3523 rtnl_lock(); 3524 3525 err = -ENODEV; 3526 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3527 if (!dev) 3528 goto done; 3529 3530 err = -EINVAL; 3531 if (mreq->mr_alen > dev->addr_len) 3532 goto done; 3533 3534 err = -ENOBUFS; 3535 i = kmalloc(sizeof(*i), GFP_KERNEL); 3536 if (i == NULL) 3537 goto done; 3538 3539 err = 0; 3540 for (ml = po->mclist; ml; ml = ml->next) { 3541 if (ml->ifindex == mreq->mr_ifindex && 3542 ml->type == mreq->mr_type && 3543 ml->alen == mreq->mr_alen && 3544 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3545 ml->count++; 3546 /* Free the new element ... */ 3547 kfree(i); 3548 goto done; 3549 } 3550 } 3551 3552 i->type = mreq->mr_type; 3553 i->ifindex = mreq->mr_ifindex; 3554 i->alen = mreq->mr_alen; 3555 memcpy(i->addr, mreq->mr_address, i->alen); 3556 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3557 i->count = 1; 3558 i->next = po->mclist; 3559 po->mclist = i; 3560 err = packet_dev_mc(dev, i, 1); 3561 if (err) { 3562 po->mclist = i->next; 3563 kfree(i); 3564 } 3565 3566 done: 3567 rtnl_unlock(); 3568 return err; 3569 } 3570 3571 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3572 { 3573 struct packet_mclist *ml, **mlp; 3574 3575 rtnl_lock(); 3576 3577 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3578 if (ml->ifindex == mreq->mr_ifindex && 3579 ml->type == mreq->mr_type && 3580 ml->alen == mreq->mr_alen && 3581 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3582 if (--ml->count == 0) { 3583 struct net_device *dev; 3584 *mlp = ml->next; 3585 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3586 if (dev) 3587 packet_dev_mc(dev, ml, -1); 3588 kfree(ml); 3589 } 3590 break; 3591 } 3592 } 3593 rtnl_unlock(); 3594 return 0; 3595 } 3596 3597 static void packet_flush_mclist(struct sock *sk) 3598 { 3599 struct packet_sock *po = pkt_sk(sk); 3600 struct packet_mclist *ml; 3601 3602 if (!po->mclist) 3603 return; 3604 3605 rtnl_lock(); 3606 while ((ml = po->mclist) != NULL) { 3607 struct net_device *dev; 3608 3609 po->mclist = ml->next; 3610 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3611 if (dev != NULL) 3612 packet_dev_mc(dev, ml, -1); 3613 kfree(ml); 3614 } 3615 rtnl_unlock(); 3616 } 3617 3618 static int 3619 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3620 { 3621 struct sock *sk = sock->sk; 3622 struct packet_sock *po = pkt_sk(sk); 3623 int ret; 3624 3625 if (level != SOL_PACKET) 3626 return -ENOPROTOOPT; 3627 3628 switch (optname) { 3629 case PACKET_ADD_MEMBERSHIP: 3630 case PACKET_DROP_MEMBERSHIP: 3631 { 3632 struct packet_mreq_max mreq; 3633 int len = optlen; 3634 memset(&mreq, 0, sizeof(mreq)); 3635 if (len < sizeof(struct packet_mreq)) 3636 return -EINVAL; 3637 if (len > sizeof(mreq)) 3638 len = sizeof(mreq); 3639 if (copy_from_user(&mreq, optval, len)) 3640 return -EFAULT; 3641 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3642 return -EINVAL; 3643 if (optname == PACKET_ADD_MEMBERSHIP) 3644 ret = packet_mc_add(sk, &mreq); 3645 else 3646 ret = packet_mc_drop(sk, &mreq); 3647 return ret; 3648 } 3649 3650 case PACKET_RX_RING: 3651 case PACKET_TX_RING: 3652 { 3653 union tpacket_req_u req_u; 3654 int len; 3655 3656 switch (po->tp_version) { 3657 case TPACKET_V1: 3658 case TPACKET_V2: 3659 len = sizeof(req_u.req); 3660 break; 3661 case TPACKET_V3: 3662 default: 3663 len = sizeof(req_u.req3); 3664 break; 3665 } 3666 if (optlen < len) 3667 return -EINVAL; 3668 if (copy_from_user(&req_u.req, optval, len)) 3669 return -EFAULT; 3670 return packet_set_ring(sk, &req_u, 0, 3671 optname == PACKET_TX_RING); 3672 } 3673 case PACKET_COPY_THRESH: 3674 { 3675 int val; 3676 3677 if (optlen != sizeof(val)) 3678 return -EINVAL; 3679 if (copy_from_user(&val, optval, sizeof(val))) 3680 return -EFAULT; 3681 3682 pkt_sk(sk)->copy_thresh = val; 3683 return 0; 3684 } 3685 case PACKET_VERSION: 3686 { 3687 int val; 3688 3689 if (optlen != sizeof(val)) 3690 return -EINVAL; 3691 if (copy_from_user(&val, optval, sizeof(val))) 3692 return -EFAULT; 3693 switch (val) { 3694 case TPACKET_V1: 3695 case TPACKET_V2: 3696 case TPACKET_V3: 3697 break; 3698 default: 3699 return -EINVAL; 3700 } 3701 lock_sock(sk); 3702 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3703 ret = -EBUSY; 3704 } else { 3705 po->tp_version = val; 3706 ret = 0; 3707 } 3708 release_sock(sk); 3709 return ret; 3710 } 3711 case PACKET_RESERVE: 3712 { 3713 unsigned int val; 3714 3715 if (optlen != sizeof(val)) 3716 return -EINVAL; 3717 if (copy_from_user(&val, optval, sizeof(val))) 3718 return -EFAULT; 3719 if (val > INT_MAX) 3720 return -EINVAL; 3721 lock_sock(sk); 3722 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3723 ret = -EBUSY; 3724 } else { 3725 po->tp_reserve = val; 3726 ret = 0; 3727 } 3728 release_sock(sk); 3729 return ret; 3730 } 3731 case PACKET_LOSS: 3732 { 3733 unsigned int val; 3734 3735 if (optlen != sizeof(val)) 3736 return -EINVAL; 3737 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3738 return -EBUSY; 3739 if (copy_from_user(&val, optval, sizeof(val))) 3740 return -EFAULT; 3741 po->tp_loss = !!val; 3742 return 0; 3743 } 3744 case PACKET_AUXDATA: 3745 { 3746 int val; 3747 3748 if (optlen < sizeof(val)) 3749 return -EINVAL; 3750 if (copy_from_user(&val, optval, sizeof(val))) 3751 return -EFAULT; 3752 3753 po->auxdata = !!val; 3754 return 0; 3755 } 3756 case PACKET_ORIGDEV: 3757 { 3758 int val; 3759 3760 if (optlen < sizeof(val)) 3761 return -EINVAL; 3762 if (copy_from_user(&val, optval, sizeof(val))) 3763 return -EFAULT; 3764 3765 po->origdev = !!val; 3766 return 0; 3767 } 3768 case PACKET_VNET_HDR: 3769 { 3770 int val; 3771 3772 if (sock->type != SOCK_RAW) 3773 return -EINVAL; 3774 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3775 return -EBUSY; 3776 if (optlen < sizeof(val)) 3777 return -EINVAL; 3778 if (copy_from_user(&val, optval, sizeof(val))) 3779 return -EFAULT; 3780 3781 po->has_vnet_hdr = !!val; 3782 return 0; 3783 } 3784 case PACKET_TIMESTAMP: 3785 { 3786 int val; 3787 3788 if (optlen != sizeof(val)) 3789 return -EINVAL; 3790 if (copy_from_user(&val, optval, sizeof(val))) 3791 return -EFAULT; 3792 3793 po->tp_tstamp = val; 3794 return 0; 3795 } 3796 case PACKET_FANOUT: 3797 { 3798 int val; 3799 3800 if (optlen != sizeof(val)) 3801 return -EINVAL; 3802 if (copy_from_user(&val, optval, sizeof(val))) 3803 return -EFAULT; 3804 3805 return fanout_add(sk, val & 0xffff, val >> 16); 3806 } 3807 case PACKET_FANOUT_DATA: 3808 { 3809 if (!po->fanout) 3810 return -EINVAL; 3811 3812 return fanout_set_data(po, optval, optlen); 3813 } 3814 case PACKET_TX_HAS_OFF: 3815 { 3816 unsigned int val; 3817 3818 if (optlen != sizeof(val)) 3819 return -EINVAL; 3820 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3821 return -EBUSY; 3822 if (copy_from_user(&val, optval, sizeof(val))) 3823 return -EFAULT; 3824 po->tp_tx_has_off = !!val; 3825 return 0; 3826 } 3827 case PACKET_QDISC_BYPASS: 3828 { 3829 int val; 3830 3831 if (optlen != sizeof(val)) 3832 return -EINVAL; 3833 if (copy_from_user(&val, optval, sizeof(val))) 3834 return -EFAULT; 3835 3836 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3837 return 0; 3838 } 3839 default: 3840 return -ENOPROTOOPT; 3841 } 3842 } 3843 3844 static int packet_getsockopt(struct socket *sock, int level, int optname, 3845 char __user *optval, int __user *optlen) 3846 { 3847 int len; 3848 int val, lv = sizeof(val); 3849 struct sock *sk = sock->sk; 3850 struct packet_sock *po = pkt_sk(sk); 3851 void *data = &val; 3852 union tpacket_stats_u st; 3853 struct tpacket_rollover_stats rstats; 3854 3855 if (level != SOL_PACKET) 3856 return -ENOPROTOOPT; 3857 3858 if (get_user(len, optlen)) 3859 return -EFAULT; 3860 3861 if (len < 0) 3862 return -EINVAL; 3863 3864 switch (optname) { 3865 case PACKET_STATISTICS: 3866 spin_lock_bh(&sk->sk_receive_queue.lock); 3867 memcpy(&st, &po->stats, sizeof(st)); 3868 memset(&po->stats, 0, sizeof(po->stats)); 3869 spin_unlock_bh(&sk->sk_receive_queue.lock); 3870 3871 if (po->tp_version == TPACKET_V3) { 3872 lv = sizeof(struct tpacket_stats_v3); 3873 st.stats3.tp_packets += st.stats3.tp_drops; 3874 data = &st.stats3; 3875 } else { 3876 lv = sizeof(struct tpacket_stats); 3877 st.stats1.tp_packets += st.stats1.tp_drops; 3878 data = &st.stats1; 3879 } 3880 3881 break; 3882 case PACKET_AUXDATA: 3883 val = po->auxdata; 3884 break; 3885 case PACKET_ORIGDEV: 3886 val = po->origdev; 3887 break; 3888 case PACKET_VNET_HDR: 3889 val = po->has_vnet_hdr; 3890 break; 3891 case PACKET_VERSION: 3892 val = po->tp_version; 3893 break; 3894 case PACKET_HDRLEN: 3895 if (len > sizeof(int)) 3896 len = sizeof(int); 3897 if (len < sizeof(int)) 3898 return -EINVAL; 3899 if (copy_from_user(&val, optval, len)) 3900 return -EFAULT; 3901 switch (val) { 3902 case TPACKET_V1: 3903 val = sizeof(struct tpacket_hdr); 3904 break; 3905 case TPACKET_V2: 3906 val = sizeof(struct tpacket2_hdr); 3907 break; 3908 case TPACKET_V3: 3909 val = sizeof(struct tpacket3_hdr); 3910 break; 3911 default: 3912 return -EINVAL; 3913 } 3914 break; 3915 case PACKET_RESERVE: 3916 val = po->tp_reserve; 3917 break; 3918 case PACKET_LOSS: 3919 val = po->tp_loss; 3920 break; 3921 case PACKET_TIMESTAMP: 3922 val = po->tp_tstamp; 3923 break; 3924 case PACKET_FANOUT: 3925 val = (po->fanout ? 3926 ((u32)po->fanout->id | 3927 ((u32)po->fanout->type << 16) | 3928 ((u32)po->fanout->flags << 24)) : 3929 0); 3930 break; 3931 case PACKET_ROLLOVER_STATS: 3932 if (!po->rollover) 3933 return -EINVAL; 3934 rstats.tp_all = atomic_long_read(&po->rollover->num); 3935 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 3936 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 3937 data = &rstats; 3938 lv = sizeof(rstats); 3939 break; 3940 case PACKET_TX_HAS_OFF: 3941 val = po->tp_tx_has_off; 3942 break; 3943 case PACKET_QDISC_BYPASS: 3944 val = packet_use_direct_xmit(po); 3945 break; 3946 default: 3947 return -ENOPROTOOPT; 3948 } 3949 3950 if (len > lv) 3951 len = lv; 3952 if (put_user(len, optlen)) 3953 return -EFAULT; 3954 if (copy_to_user(optval, data, len)) 3955 return -EFAULT; 3956 return 0; 3957 } 3958 3959 3960 #ifdef CONFIG_COMPAT 3961 static int compat_packet_setsockopt(struct socket *sock, int level, int optname, 3962 char __user *optval, unsigned int optlen) 3963 { 3964 struct packet_sock *po = pkt_sk(sock->sk); 3965 3966 if (level != SOL_PACKET) 3967 return -ENOPROTOOPT; 3968 3969 if (optname == PACKET_FANOUT_DATA && 3970 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) { 3971 optval = (char __user *)get_compat_bpf_fprog(optval); 3972 if (!optval) 3973 return -EFAULT; 3974 optlen = sizeof(struct sock_fprog); 3975 } 3976 3977 return packet_setsockopt(sock, level, optname, optval, optlen); 3978 } 3979 #endif 3980 3981 static int packet_notifier(struct notifier_block *this, 3982 unsigned long msg, void *ptr) 3983 { 3984 struct sock *sk; 3985 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3986 struct net *net = dev_net(dev); 3987 3988 rcu_read_lock(); 3989 sk_for_each_rcu(sk, &net->packet.sklist) { 3990 struct packet_sock *po = pkt_sk(sk); 3991 3992 switch (msg) { 3993 case NETDEV_UNREGISTER: 3994 if (po->mclist) 3995 packet_dev_mclist_delete(dev, &po->mclist); 3996 /* fallthrough */ 3997 3998 case NETDEV_DOWN: 3999 if (dev->ifindex == po->ifindex) { 4000 spin_lock(&po->bind_lock); 4001 if (po->running) { 4002 __unregister_prot_hook(sk, false); 4003 sk->sk_err = ENETDOWN; 4004 if (!sock_flag(sk, SOCK_DEAD)) 4005 sk->sk_error_report(sk); 4006 } 4007 if (msg == NETDEV_UNREGISTER) { 4008 packet_cached_dev_reset(po); 4009 po->ifindex = -1; 4010 if (po->prot_hook.dev) 4011 dev_put(po->prot_hook.dev); 4012 po->prot_hook.dev = NULL; 4013 } 4014 spin_unlock(&po->bind_lock); 4015 } 4016 break; 4017 case NETDEV_UP: 4018 if (dev->ifindex == po->ifindex) { 4019 spin_lock(&po->bind_lock); 4020 if (po->num) 4021 register_prot_hook(sk); 4022 spin_unlock(&po->bind_lock); 4023 } 4024 break; 4025 } 4026 } 4027 rcu_read_unlock(); 4028 return NOTIFY_DONE; 4029 } 4030 4031 4032 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4033 unsigned long arg) 4034 { 4035 struct sock *sk = sock->sk; 4036 4037 switch (cmd) { 4038 case SIOCOUTQ: 4039 { 4040 int amount = sk_wmem_alloc_get(sk); 4041 4042 return put_user(amount, (int __user *)arg); 4043 } 4044 case SIOCINQ: 4045 { 4046 struct sk_buff *skb; 4047 int amount = 0; 4048 4049 spin_lock_bh(&sk->sk_receive_queue.lock); 4050 skb = skb_peek(&sk->sk_receive_queue); 4051 if (skb) 4052 amount = skb->len; 4053 spin_unlock_bh(&sk->sk_receive_queue.lock); 4054 return put_user(amount, (int __user *)arg); 4055 } 4056 case SIOCGSTAMP: 4057 return sock_get_timestamp(sk, (struct timeval __user *)arg); 4058 case SIOCGSTAMPNS: 4059 return sock_get_timestampns(sk, (struct timespec __user *)arg); 4060 4061 #ifdef CONFIG_INET 4062 case SIOCADDRT: 4063 case SIOCDELRT: 4064 case SIOCDARP: 4065 case SIOCGARP: 4066 case SIOCSARP: 4067 case SIOCGIFADDR: 4068 case SIOCSIFADDR: 4069 case SIOCGIFBRDADDR: 4070 case SIOCSIFBRDADDR: 4071 case SIOCGIFNETMASK: 4072 case SIOCSIFNETMASK: 4073 case SIOCGIFDSTADDR: 4074 case SIOCSIFDSTADDR: 4075 case SIOCSIFFLAGS: 4076 return inet_dgram_ops.ioctl(sock, cmd, arg); 4077 #endif 4078 4079 default: 4080 return -ENOIOCTLCMD; 4081 } 4082 return 0; 4083 } 4084 4085 static unsigned int packet_poll(struct file *file, struct socket *sock, 4086 poll_table *wait) 4087 { 4088 struct sock *sk = sock->sk; 4089 struct packet_sock *po = pkt_sk(sk); 4090 unsigned int mask = datagram_poll(file, sock, wait); 4091 4092 spin_lock_bh(&sk->sk_receive_queue.lock); 4093 if (po->rx_ring.pg_vec) { 4094 if (!packet_previous_rx_frame(po, &po->rx_ring, 4095 TP_STATUS_KERNEL)) 4096 mask |= POLLIN | POLLRDNORM; 4097 } 4098 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 4099 po->pressure = 0; 4100 spin_unlock_bh(&sk->sk_receive_queue.lock); 4101 spin_lock_bh(&sk->sk_write_queue.lock); 4102 if (po->tx_ring.pg_vec) { 4103 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4104 mask |= POLLOUT | POLLWRNORM; 4105 } 4106 spin_unlock_bh(&sk->sk_write_queue.lock); 4107 return mask; 4108 } 4109 4110 4111 /* Dirty? Well, I still did not learn better way to account 4112 * for user mmaps. 4113 */ 4114 4115 static void packet_mm_open(struct vm_area_struct *vma) 4116 { 4117 struct file *file = vma->vm_file; 4118 struct socket *sock = file->private_data; 4119 struct sock *sk = sock->sk; 4120 4121 if (sk) 4122 atomic_inc(&pkt_sk(sk)->mapped); 4123 } 4124 4125 static void packet_mm_close(struct vm_area_struct *vma) 4126 { 4127 struct file *file = vma->vm_file; 4128 struct socket *sock = file->private_data; 4129 struct sock *sk = sock->sk; 4130 4131 if (sk) 4132 atomic_dec(&pkt_sk(sk)->mapped); 4133 } 4134 4135 static const struct vm_operations_struct packet_mmap_ops = { 4136 .open = packet_mm_open, 4137 .close = packet_mm_close, 4138 }; 4139 4140 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4141 unsigned int len) 4142 { 4143 int i; 4144 4145 for (i = 0; i < len; i++) { 4146 if (likely(pg_vec[i].buffer)) { 4147 if (is_vmalloc_addr(pg_vec[i].buffer)) 4148 vfree(pg_vec[i].buffer); 4149 else 4150 free_pages((unsigned long)pg_vec[i].buffer, 4151 order); 4152 pg_vec[i].buffer = NULL; 4153 } 4154 } 4155 kfree(pg_vec); 4156 } 4157 4158 static char *alloc_one_pg_vec_page(unsigned long order) 4159 { 4160 char *buffer; 4161 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4162 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4163 4164 buffer = (char *) __get_free_pages(gfp_flags, order); 4165 if (buffer) 4166 return buffer; 4167 4168 /* __get_free_pages failed, fall back to vmalloc */ 4169 buffer = vzalloc((1 << order) * PAGE_SIZE); 4170 if (buffer) 4171 return buffer; 4172 4173 /* vmalloc failed, lets dig into swap here */ 4174 gfp_flags &= ~__GFP_NORETRY; 4175 buffer = (char *) __get_free_pages(gfp_flags, order); 4176 if (buffer) 4177 return buffer; 4178 4179 /* complete and utter failure */ 4180 return NULL; 4181 } 4182 4183 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4184 { 4185 unsigned int block_nr = req->tp_block_nr; 4186 struct pgv *pg_vec; 4187 int i; 4188 4189 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 4190 if (unlikely(!pg_vec)) 4191 goto out; 4192 4193 for (i = 0; i < block_nr; i++) { 4194 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4195 if (unlikely(!pg_vec[i].buffer)) 4196 goto out_free_pgvec; 4197 } 4198 4199 out: 4200 return pg_vec; 4201 4202 out_free_pgvec: 4203 free_pg_vec(pg_vec, order, block_nr); 4204 pg_vec = NULL; 4205 goto out; 4206 } 4207 4208 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4209 int closing, int tx_ring) 4210 { 4211 struct pgv *pg_vec = NULL; 4212 struct packet_sock *po = pkt_sk(sk); 4213 int was_running, order = 0; 4214 struct packet_ring_buffer *rb; 4215 struct sk_buff_head *rb_queue; 4216 __be16 num; 4217 int err = -EINVAL; 4218 /* Added to avoid minimal code churn */ 4219 struct tpacket_req *req = &req_u->req; 4220 4221 lock_sock(sk); 4222 4223 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4224 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4225 4226 err = -EBUSY; 4227 if (!closing) { 4228 if (atomic_read(&po->mapped)) 4229 goto out; 4230 if (packet_read_pending(rb)) 4231 goto out; 4232 } 4233 4234 if (req->tp_block_nr) { 4235 /* Sanity tests and some calculations */ 4236 err = -EBUSY; 4237 if (unlikely(rb->pg_vec)) 4238 goto out; 4239 4240 switch (po->tp_version) { 4241 case TPACKET_V1: 4242 po->tp_hdrlen = TPACKET_HDRLEN; 4243 break; 4244 case TPACKET_V2: 4245 po->tp_hdrlen = TPACKET2_HDRLEN; 4246 break; 4247 case TPACKET_V3: 4248 po->tp_hdrlen = TPACKET3_HDRLEN; 4249 break; 4250 } 4251 4252 err = -EINVAL; 4253 if (unlikely((int)req->tp_block_size <= 0)) 4254 goto out; 4255 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4256 goto out; 4257 if (po->tp_version >= TPACKET_V3 && 4258 req->tp_block_size <= 4259 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv)) 4260 goto out; 4261 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 4262 po->tp_reserve)) 4263 goto out; 4264 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4265 goto out; 4266 4267 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4268 if (unlikely(rb->frames_per_block == 0)) 4269 goto out; 4270 if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr)) 4271 goto out; 4272 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4273 req->tp_frame_nr)) 4274 goto out; 4275 4276 err = -ENOMEM; 4277 order = get_order(req->tp_block_size); 4278 pg_vec = alloc_pg_vec(req, order); 4279 if (unlikely(!pg_vec)) 4280 goto out; 4281 switch (po->tp_version) { 4282 case TPACKET_V3: 4283 /* Block transmit is not supported yet */ 4284 if (!tx_ring) { 4285 init_prb_bdqc(po, rb, pg_vec, req_u); 4286 } else { 4287 struct tpacket_req3 *req3 = &req_u->req3; 4288 4289 if (req3->tp_retire_blk_tov || 4290 req3->tp_sizeof_priv || 4291 req3->tp_feature_req_word) { 4292 err = -EINVAL; 4293 goto out; 4294 } 4295 } 4296 break; 4297 default: 4298 break; 4299 } 4300 } 4301 /* Done */ 4302 else { 4303 err = -EINVAL; 4304 if (unlikely(req->tp_frame_nr)) 4305 goto out; 4306 } 4307 4308 4309 /* Detach socket from network */ 4310 spin_lock(&po->bind_lock); 4311 was_running = po->running; 4312 num = po->num; 4313 if (was_running) { 4314 po->num = 0; 4315 __unregister_prot_hook(sk, false); 4316 } 4317 spin_unlock(&po->bind_lock); 4318 4319 synchronize_net(); 4320 4321 err = -EBUSY; 4322 mutex_lock(&po->pg_vec_lock); 4323 if (closing || atomic_read(&po->mapped) == 0) { 4324 err = 0; 4325 spin_lock_bh(&rb_queue->lock); 4326 swap(rb->pg_vec, pg_vec); 4327 rb->frame_max = (req->tp_frame_nr - 1); 4328 rb->head = 0; 4329 rb->frame_size = req->tp_frame_size; 4330 spin_unlock_bh(&rb_queue->lock); 4331 4332 swap(rb->pg_vec_order, order); 4333 swap(rb->pg_vec_len, req->tp_block_nr); 4334 4335 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4336 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4337 tpacket_rcv : packet_rcv; 4338 skb_queue_purge(rb_queue); 4339 if (atomic_read(&po->mapped)) 4340 pr_err("packet_mmap: vma is busy: %d\n", 4341 atomic_read(&po->mapped)); 4342 } 4343 mutex_unlock(&po->pg_vec_lock); 4344 4345 spin_lock(&po->bind_lock); 4346 if (was_running) { 4347 po->num = num; 4348 register_prot_hook(sk); 4349 } 4350 spin_unlock(&po->bind_lock); 4351 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4352 /* Because we don't support block-based V3 on tx-ring */ 4353 if (!tx_ring) 4354 prb_shutdown_retire_blk_timer(po, rb_queue); 4355 } 4356 4357 if (pg_vec) 4358 free_pg_vec(pg_vec, order, req->tp_block_nr); 4359 out: 4360 release_sock(sk); 4361 return err; 4362 } 4363 4364 static int packet_mmap(struct file *file, struct socket *sock, 4365 struct vm_area_struct *vma) 4366 { 4367 struct sock *sk = sock->sk; 4368 struct packet_sock *po = pkt_sk(sk); 4369 unsigned long size, expected_size; 4370 struct packet_ring_buffer *rb; 4371 unsigned long start; 4372 int err = -EINVAL; 4373 int i; 4374 4375 if (vma->vm_pgoff) 4376 return -EINVAL; 4377 4378 mutex_lock(&po->pg_vec_lock); 4379 4380 expected_size = 0; 4381 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4382 if (rb->pg_vec) { 4383 expected_size += rb->pg_vec_len 4384 * rb->pg_vec_pages 4385 * PAGE_SIZE; 4386 } 4387 } 4388 4389 if (expected_size == 0) 4390 goto out; 4391 4392 size = vma->vm_end - vma->vm_start; 4393 if (size != expected_size) 4394 goto out; 4395 4396 start = vma->vm_start; 4397 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4398 if (rb->pg_vec == NULL) 4399 continue; 4400 4401 for (i = 0; i < rb->pg_vec_len; i++) { 4402 struct page *page; 4403 void *kaddr = rb->pg_vec[i].buffer; 4404 int pg_num; 4405 4406 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4407 page = pgv_to_page(kaddr); 4408 err = vm_insert_page(vma, start, page); 4409 if (unlikely(err)) 4410 goto out; 4411 start += PAGE_SIZE; 4412 kaddr += PAGE_SIZE; 4413 } 4414 } 4415 } 4416 4417 atomic_inc(&po->mapped); 4418 vma->vm_ops = &packet_mmap_ops; 4419 err = 0; 4420 4421 out: 4422 mutex_unlock(&po->pg_vec_lock); 4423 return err; 4424 } 4425 4426 static const struct proto_ops packet_ops_spkt = { 4427 .family = PF_PACKET, 4428 .owner = THIS_MODULE, 4429 .release = packet_release, 4430 .bind = packet_bind_spkt, 4431 .connect = sock_no_connect, 4432 .socketpair = sock_no_socketpair, 4433 .accept = sock_no_accept, 4434 .getname = packet_getname_spkt, 4435 .poll = datagram_poll, 4436 .ioctl = packet_ioctl, 4437 .listen = sock_no_listen, 4438 .shutdown = sock_no_shutdown, 4439 .setsockopt = sock_no_setsockopt, 4440 .getsockopt = sock_no_getsockopt, 4441 .sendmsg = packet_sendmsg_spkt, 4442 .recvmsg = packet_recvmsg, 4443 .mmap = sock_no_mmap, 4444 .sendpage = sock_no_sendpage, 4445 }; 4446 4447 static const struct proto_ops packet_ops = { 4448 .family = PF_PACKET, 4449 .owner = THIS_MODULE, 4450 .release = packet_release, 4451 .bind = packet_bind, 4452 .connect = sock_no_connect, 4453 .socketpair = sock_no_socketpair, 4454 .accept = sock_no_accept, 4455 .getname = packet_getname, 4456 .poll = packet_poll, 4457 .ioctl = packet_ioctl, 4458 .listen = sock_no_listen, 4459 .shutdown = sock_no_shutdown, 4460 .setsockopt = packet_setsockopt, 4461 .getsockopt = packet_getsockopt, 4462 #ifdef CONFIG_COMPAT 4463 .compat_setsockopt = compat_packet_setsockopt, 4464 #endif 4465 .sendmsg = packet_sendmsg, 4466 .recvmsg = packet_recvmsg, 4467 .mmap = packet_mmap, 4468 .sendpage = sock_no_sendpage, 4469 }; 4470 4471 static const struct net_proto_family packet_family_ops = { 4472 .family = PF_PACKET, 4473 .create = packet_create, 4474 .owner = THIS_MODULE, 4475 }; 4476 4477 static struct notifier_block packet_netdev_notifier = { 4478 .notifier_call = packet_notifier, 4479 }; 4480 4481 #ifdef CONFIG_PROC_FS 4482 4483 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4484 __acquires(RCU) 4485 { 4486 struct net *net = seq_file_net(seq); 4487 4488 rcu_read_lock(); 4489 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4490 } 4491 4492 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4493 { 4494 struct net *net = seq_file_net(seq); 4495 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4496 } 4497 4498 static void packet_seq_stop(struct seq_file *seq, void *v) 4499 __releases(RCU) 4500 { 4501 rcu_read_unlock(); 4502 } 4503 4504 static int packet_seq_show(struct seq_file *seq, void *v) 4505 { 4506 if (v == SEQ_START_TOKEN) 4507 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4508 else { 4509 struct sock *s = sk_entry(v); 4510 const struct packet_sock *po = pkt_sk(s); 4511 4512 seq_printf(seq, 4513 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4514 s, 4515 refcount_read(&s->sk_refcnt), 4516 s->sk_type, 4517 ntohs(po->num), 4518 po->ifindex, 4519 po->running, 4520 atomic_read(&s->sk_rmem_alloc), 4521 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4522 sock_i_ino(s)); 4523 } 4524 4525 return 0; 4526 } 4527 4528 static const struct seq_operations packet_seq_ops = { 4529 .start = packet_seq_start, 4530 .next = packet_seq_next, 4531 .stop = packet_seq_stop, 4532 .show = packet_seq_show, 4533 }; 4534 4535 static int packet_seq_open(struct inode *inode, struct file *file) 4536 { 4537 return seq_open_net(inode, file, &packet_seq_ops, 4538 sizeof(struct seq_net_private)); 4539 } 4540 4541 static const struct file_operations packet_seq_fops = { 4542 .owner = THIS_MODULE, 4543 .open = packet_seq_open, 4544 .read = seq_read, 4545 .llseek = seq_lseek, 4546 .release = seq_release_net, 4547 }; 4548 4549 #endif 4550 4551 static int __net_init packet_net_init(struct net *net) 4552 { 4553 mutex_init(&net->packet.sklist_lock); 4554 INIT_HLIST_HEAD(&net->packet.sklist); 4555 4556 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4557 return -ENOMEM; 4558 4559 return 0; 4560 } 4561 4562 static void __net_exit packet_net_exit(struct net *net) 4563 { 4564 remove_proc_entry("packet", net->proc_net); 4565 } 4566 4567 static struct pernet_operations packet_net_ops = { 4568 .init = packet_net_init, 4569 .exit = packet_net_exit, 4570 }; 4571 4572 4573 static void __exit packet_exit(void) 4574 { 4575 unregister_netdevice_notifier(&packet_netdev_notifier); 4576 unregister_pernet_subsys(&packet_net_ops); 4577 sock_unregister(PF_PACKET); 4578 proto_unregister(&packet_proto); 4579 } 4580 4581 static int __init packet_init(void) 4582 { 4583 int rc = proto_register(&packet_proto, 0); 4584 4585 if (rc != 0) 4586 goto out; 4587 4588 sock_register(&packet_family_ops); 4589 register_pernet_subsys(&packet_net_ops); 4590 register_netdevice_notifier(&packet_netdev_notifier); 4591 out: 4592 return rc; 4593 } 4594 4595 module_init(packet_init); 4596 module_exit(packet_exit); 4597 MODULE_LICENSE("GPL"); 4598 MODULE_ALIAS_NETPROTO(PF_PACKET); 4599