1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * PACKET - implements raw packet sockets. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * 13 * Fixes: 14 * Alan Cox : verify_area() now used correctly 15 * Alan Cox : new skbuff lists, look ma no backlogs! 16 * Alan Cox : tidied skbuff lists. 17 * Alan Cox : Now uses generic datagram routines I 18 * added. Also fixed the peek/read crash 19 * from all old Linux datagram code. 20 * Alan Cox : Uses the improved datagram code. 21 * Alan Cox : Added NULL's for socket options. 22 * Alan Cox : Re-commented the code. 23 * Alan Cox : Use new kernel side addressing 24 * Rob Janssen : Correct MTU usage. 25 * Dave Platt : Counter leaks caused by incorrect 26 * interrupt locking and some slightly 27 * dubious gcc output. Can you read 28 * compiler: it said _VOLATILE_ 29 * Richard Kooijman : Timestamp fixes. 30 * Alan Cox : New buffers. Use sk->mac.raw. 31 * Alan Cox : sendmsg/recvmsg support. 32 * Alan Cox : Protocol setting support 33 * Alexey Kuznetsov : Untied from IPv4 stack. 34 * Cyrus Durgin : Fixed kerneld for kmod. 35 * Michal Ostrowski : Module initialization cleanup. 36 * Ulises Alonso : Frame number limit removal and 37 * packet_set_ring memory leak. 38 * Eric Biederman : Allow for > 8 byte hardware addresses. 39 * The convention is that longer addresses 40 * will simply extend the hardware address 41 * byte arrays at the end of sockaddr_ll 42 * and packet_mreq. 43 * Johann Baudy : Added TX RING. 44 * Chetan Loke : Implemented TPACKET_V3 block abstraction 45 * layer. 46 * Copyright (C) 2011, <lokec@ccs.neu.edu> 47 */ 48 49 #include <linux/types.h> 50 #include <linux/mm.h> 51 #include <linux/capability.h> 52 #include <linux/fcntl.h> 53 #include <linux/socket.h> 54 #include <linux/in.h> 55 #include <linux/inet.h> 56 #include <linux/netdevice.h> 57 #include <linux/if_packet.h> 58 #include <linux/wireless.h> 59 #include <linux/kernel.h> 60 #include <linux/kmod.h> 61 #include <linux/slab.h> 62 #include <linux/vmalloc.h> 63 #include <net/net_namespace.h> 64 #include <net/ip.h> 65 #include <net/protocol.h> 66 #include <linux/skbuff.h> 67 #include <net/sock.h> 68 #include <linux/errno.h> 69 #include <linux/timer.h> 70 #include <linux/uaccess.h> 71 #include <asm/ioctls.h> 72 #include <asm/page.h> 73 #include <asm/cacheflush.h> 74 #include <asm/io.h> 75 #include <linux/proc_fs.h> 76 #include <linux/seq_file.h> 77 #include <linux/poll.h> 78 #include <linux/module.h> 79 #include <linux/init.h> 80 #include <linux/mutex.h> 81 #include <linux/if_vlan.h> 82 #include <linux/virtio_net.h> 83 #include <linux/errqueue.h> 84 #include <linux/net_tstamp.h> 85 #include <linux/percpu.h> 86 #ifdef CONFIG_INET 87 #include <net/inet_common.h> 88 #endif 89 #include <linux/bpf.h> 90 #include <net/compat.h> 91 92 #include "internal.h" 93 94 /* 95 Assumptions: 96 - if device has no dev->hard_header routine, it adds and removes ll header 97 inside itself. In this case ll header is invisible outside of device, 98 but higher levels still should reserve dev->hard_header_len. 99 Some devices are enough clever to reallocate skb, when header 100 will not fit to reserved space (tunnel), another ones are silly 101 (PPP). 102 - packet socket receives packets with pulled ll header, 103 so that SOCK_RAW should push it back. 104 105 On receive: 106 ----------- 107 108 Incoming, dev->hard_header!=NULL 109 mac_header -> ll header 110 data -> data 111 112 Outgoing, dev->hard_header!=NULL 113 mac_header -> ll header 114 data -> ll header 115 116 Incoming, dev->hard_header==NULL 117 mac_header -> UNKNOWN position. It is very likely, that it points to ll 118 header. PPP makes it, that is wrong, because introduce 119 assymetry between rx and tx paths. 120 data -> data 121 122 Outgoing, dev->hard_header==NULL 123 mac_header -> data. ll header is still not built! 124 data -> data 125 126 Resume 127 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 128 129 130 On transmit: 131 ------------ 132 133 dev->hard_header != NULL 134 mac_header -> ll header 135 data -> ll header 136 137 dev->hard_header == NULL (ll header is added by device, we cannot control it) 138 mac_header -> data 139 data -> data 140 141 We should set nh.raw on output to correct posistion, 142 packet classifier depends on it. 143 */ 144 145 /* Private packet socket structures. */ 146 147 /* identical to struct packet_mreq except it has 148 * a longer address field. 149 */ 150 struct packet_mreq_max { 151 int mr_ifindex; 152 unsigned short mr_type; 153 unsigned short mr_alen; 154 unsigned char mr_address[MAX_ADDR_LEN]; 155 }; 156 157 union tpacket_uhdr { 158 struct tpacket_hdr *h1; 159 struct tpacket2_hdr *h2; 160 struct tpacket3_hdr *h3; 161 void *raw; 162 }; 163 164 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 165 int closing, int tx_ring); 166 167 #define V3_ALIGNMENT (8) 168 169 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 170 171 #define BLK_PLUS_PRIV(sz_of_priv) \ 172 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 173 174 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 175 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 176 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 177 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 178 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 179 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 180 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 181 182 struct packet_sock; 183 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 184 struct packet_type *pt, struct net_device *orig_dev); 185 186 static void *packet_previous_frame(struct packet_sock *po, 187 struct packet_ring_buffer *rb, 188 int status); 189 static void packet_increment_head(struct packet_ring_buffer *buff); 190 static int prb_curr_blk_in_use(struct tpacket_block_desc *); 191 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 192 struct packet_sock *); 193 static void prb_retire_current_block(struct tpacket_kbdq_core *, 194 struct packet_sock *, unsigned int status); 195 static int prb_queue_frozen(struct tpacket_kbdq_core *); 196 static void prb_open_block(struct tpacket_kbdq_core *, 197 struct tpacket_block_desc *); 198 static void prb_retire_rx_blk_timer_expired(struct timer_list *); 199 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 200 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 201 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 202 struct tpacket3_hdr *); 203 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 204 struct tpacket3_hdr *); 205 static void packet_flush_mclist(struct sock *sk); 206 static u16 packet_pick_tx_queue(struct sk_buff *skb); 207 208 struct packet_skb_cb { 209 union { 210 struct sockaddr_pkt pkt; 211 union { 212 /* Trick: alias skb original length with 213 * ll.sll_family and ll.protocol in order 214 * to save room. 215 */ 216 unsigned int origlen; 217 struct sockaddr_ll ll; 218 }; 219 } sa; 220 }; 221 222 #define vio_le() virtio_legacy_is_little_endian() 223 224 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 225 226 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 227 #define GET_PBLOCK_DESC(x, bid) \ 228 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 229 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 230 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 231 #define GET_NEXT_PRB_BLK_NUM(x) \ 232 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 233 ((x)->kactive_blk_num+1) : 0) 234 235 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 236 static void __fanout_link(struct sock *sk, struct packet_sock *po); 237 238 static int packet_direct_xmit(struct sk_buff *skb) 239 { 240 return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); 241 } 242 243 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 244 { 245 struct net_device *dev; 246 247 rcu_read_lock(); 248 dev = rcu_dereference(po->cached_dev); 249 if (likely(dev)) 250 dev_hold(dev); 251 rcu_read_unlock(); 252 253 return dev; 254 } 255 256 static void packet_cached_dev_assign(struct packet_sock *po, 257 struct net_device *dev) 258 { 259 rcu_assign_pointer(po->cached_dev, dev); 260 } 261 262 static void packet_cached_dev_reset(struct packet_sock *po) 263 { 264 RCU_INIT_POINTER(po->cached_dev, NULL); 265 } 266 267 static bool packet_use_direct_xmit(const struct packet_sock *po) 268 { 269 return po->xmit == packet_direct_xmit; 270 } 271 272 static u16 packet_pick_tx_queue(struct sk_buff *skb) 273 { 274 struct net_device *dev = skb->dev; 275 const struct net_device_ops *ops = dev->netdev_ops; 276 int cpu = raw_smp_processor_id(); 277 u16 queue_index; 278 279 #ifdef CONFIG_XPS 280 skb->sender_cpu = cpu + 1; 281 #endif 282 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues); 283 if (ops->ndo_select_queue) { 284 queue_index = ops->ndo_select_queue(dev, skb, NULL); 285 queue_index = netdev_cap_txqueue(dev, queue_index); 286 } else { 287 queue_index = netdev_pick_tx(dev, skb, NULL); 288 } 289 290 return queue_index; 291 } 292 293 /* __register_prot_hook must be invoked through register_prot_hook 294 * or from a context in which asynchronous accesses to the packet 295 * socket is not possible (packet_create()). 296 */ 297 static void __register_prot_hook(struct sock *sk) 298 { 299 struct packet_sock *po = pkt_sk(sk); 300 301 if (!po->running) { 302 if (po->fanout) 303 __fanout_link(sk, po); 304 else 305 dev_add_pack(&po->prot_hook); 306 307 sock_hold(sk); 308 po->running = 1; 309 } 310 } 311 312 static void register_prot_hook(struct sock *sk) 313 { 314 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock); 315 __register_prot_hook(sk); 316 } 317 318 /* If the sync parameter is true, we will temporarily drop 319 * the po->bind_lock and do a synchronize_net to make sure no 320 * asynchronous packet processing paths still refer to the elements 321 * of po->prot_hook. If the sync parameter is false, it is the 322 * callers responsibility to take care of this. 323 */ 324 static void __unregister_prot_hook(struct sock *sk, bool sync) 325 { 326 struct packet_sock *po = pkt_sk(sk); 327 328 lockdep_assert_held_once(&po->bind_lock); 329 330 po->running = 0; 331 332 if (po->fanout) 333 __fanout_unlink(sk, po); 334 else 335 __dev_remove_pack(&po->prot_hook); 336 337 __sock_put(sk); 338 339 if (sync) { 340 spin_unlock(&po->bind_lock); 341 synchronize_net(); 342 spin_lock(&po->bind_lock); 343 } 344 } 345 346 static void unregister_prot_hook(struct sock *sk, bool sync) 347 { 348 struct packet_sock *po = pkt_sk(sk); 349 350 if (po->running) 351 __unregister_prot_hook(sk, sync); 352 } 353 354 static inline struct page * __pure pgv_to_page(void *addr) 355 { 356 if (is_vmalloc_addr(addr)) 357 return vmalloc_to_page(addr); 358 return virt_to_page(addr); 359 } 360 361 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 362 { 363 union tpacket_uhdr h; 364 365 h.raw = frame; 366 switch (po->tp_version) { 367 case TPACKET_V1: 368 h.h1->tp_status = status; 369 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 370 break; 371 case TPACKET_V2: 372 h.h2->tp_status = status; 373 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 374 break; 375 case TPACKET_V3: 376 h.h3->tp_status = status; 377 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 378 break; 379 default: 380 WARN(1, "TPACKET version not supported.\n"); 381 BUG(); 382 } 383 384 smp_wmb(); 385 } 386 387 static int __packet_get_status(const struct packet_sock *po, void *frame) 388 { 389 union tpacket_uhdr h; 390 391 smp_rmb(); 392 393 h.raw = frame; 394 switch (po->tp_version) { 395 case TPACKET_V1: 396 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 397 return h.h1->tp_status; 398 case TPACKET_V2: 399 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 400 return h.h2->tp_status; 401 case TPACKET_V3: 402 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 403 return h.h3->tp_status; 404 default: 405 WARN(1, "TPACKET version not supported.\n"); 406 BUG(); 407 return 0; 408 } 409 } 410 411 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, 412 unsigned int flags) 413 { 414 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 415 416 if (shhwtstamps && 417 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 418 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts)) 419 return TP_STATUS_TS_RAW_HARDWARE; 420 421 if (ktime_to_timespec64_cond(skb->tstamp, ts)) 422 return TP_STATUS_TS_SOFTWARE; 423 424 return 0; 425 } 426 427 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 428 struct sk_buff *skb) 429 { 430 union tpacket_uhdr h; 431 struct timespec64 ts; 432 __u32 ts_status; 433 434 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 435 return 0; 436 437 h.raw = frame; 438 /* 439 * versions 1 through 3 overflow the timestamps in y2106, since they 440 * all store the seconds in a 32-bit unsigned integer. 441 * If we create a version 4, that should have a 64-bit timestamp, 442 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit 443 * nanoseconds. 444 */ 445 switch (po->tp_version) { 446 case TPACKET_V1: 447 h.h1->tp_sec = ts.tv_sec; 448 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 449 break; 450 case TPACKET_V2: 451 h.h2->tp_sec = ts.tv_sec; 452 h.h2->tp_nsec = ts.tv_nsec; 453 break; 454 case TPACKET_V3: 455 h.h3->tp_sec = ts.tv_sec; 456 h.h3->tp_nsec = ts.tv_nsec; 457 break; 458 default: 459 WARN(1, "TPACKET version not supported.\n"); 460 BUG(); 461 } 462 463 /* one flush is safe, as both fields always lie on the same cacheline */ 464 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 465 smp_wmb(); 466 467 return ts_status; 468 } 469 470 static void *packet_lookup_frame(const struct packet_sock *po, 471 const struct packet_ring_buffer *rb, 472 unsigned int position, 473 int status) 474 { 475 unsigned int pg_vec_pos, frame_offset; 476 union tpacket_uhdr h; 477 478 pg_vec_pos = position / rb->frames_per_block; 479 frame_offset = position % rb->frames_per_block; 480 481 h.raw = rb->pg_vec[pg_vec_pos].buffer + 482 (frame_offset * rb->frame_size); 483 484 if (status != __packet_get_status(po, h.raw)) 485 return NULL; 486 487 return h.raw; 488 } 489 490 static void *packet_current_frame(struct packet_sock *po, 491 struct packet_ring_buffer *rb, 492 int status) 493 { 494 return packet_lookup_frame(po, rb, rb->head, status); 495 } 496 497 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 498 { 499 del_timer_sync(&pkc->retire_blk_timer); 500 } 501 502 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 503 struct sk_buff_head *rb_queue) 504 { 505 struct tpacket_kbdq_core *pkc; 506 507 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 508 509 spin_lock_bh(&rb_queue->lock); 510 pkc->delete_blk_timer = 1; 511 spin_unlock_bh(&rb_queue->lock); 512 513 prb_del_retire_blk_timer(pkc); 514 } 515 516 static void prb_setup_retire_blk_timer(struct packet_sock *po) 517 { 518 struct tpacket_kbdq_core *pkc; 519 520 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 521 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired, 522 0); 523 pkc->retire_blk_timer.expires = jiffies; 524 } 525 526 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 527 int blk_size_in_bytes) 528 { 529 struct net_device *dev; 530 unsigned int mbits, div; 531 struct ethtool_link_ksettings ecmd; 532 int err; 533 534 rtnl_lock(); 535 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 536 if (unlikely(!dev)) { 537 rtnl_unlock(); 538 return DEFAULT_PRB_RETIRE_TOV; 539 } 540 err = __ethtool_get_link_ksettings(dev, &ecmd); 541 rtnl_unlock(); 542 if (err) 543 return DEFAULT_PRB_RETIRE_TOV; 544 545 /* If the link speed is so slow you don't really 546 * need to worry about perf anyways 547 */ 548 if (ecmd.base.speed < SPEED_1000 || 549 ecmd.base.speed == SPEED_UNKNOWN) 550 return DEFAULT_PRB_RETIRE_TOV; 551 552 div = ecmd.base.speed / 1000; 553 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 554 555 if (div) 556 mbits /= div; 557 558 if (div) 559 return mbits + 1; 560 return mbits; 561 } 562 563 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 564 union tpacket_req_u *req_u) 565 { 566 p1->feature_req_word = req_u->req3.tp_feature_req_word; 567 } 568 569 static void init_prb_bdqc(struct packet_sock *po, 570 struct packet_ring_buffer *rb, 571 struct pgv *pg_vec, 572 union tpacket_req_u *req_u) 573 { 574 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 575 struct tpacket_block_desc *pbd; 576 577 memset(p1, 0x0, sizeof(*p1)); 578 579 p1->knxt_seq_num = 1; 580 p1->pkbdq = pg_vec; 581 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 582 p1->pkblk_start = pg_vec[0].buffer; 583 p1->kblk_size = req_u->req3.tp_block_size; 584 p1->knum_blocks = req_u->req3.tp_block_nr; 585 p1->hdrlen = po->tp_hdrlen; 586 p1->version = po->tp_version; 587 p1->last_kactive_blk_num = 0; 588 po->stats.stats3.tp_freeze_q_cnt = 0; 589 if (req_u->req3.tp_retire_blk_tov) 590 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 591 else 592 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 593 req_u->req3.tp_block_size); 594 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 595 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 596 rwlock_init(&p1->blk_fill_in_prog_lock); 597 598 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 599 prb_init_ft_ops(p1, req_u); 600 prb_setup_retire_blk_timer(po); 601 prb_open_block(p1, pbd); 602 } 603 604 /* Do NOT update the last_blk_num first. 605 * Assumes sk_buff_head lock is held. 606 */ 607 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 608 { 609 mod_timer(&pkc->retire_blk_timer, 610 jiffies + pkc->tov_in_jiffies); 611 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 612 } 613 614 /* 615 * Timer logic: 616 * 1) We refresh the timer only when we open a block. 617 * By doing this we don't waste cycles refreshing the timer 618 * on packet-by-packet basis. 619 * 620 * With a 1MB block-size, on a 1Gbps line, it will take 621 * i) ~8 ms to fill a block + ii) memcpy etc. 622 * In this cut we are not accounting for the memcpy time. 623 * 624 * So, if the user sets the 'tmo' to 10ms then the timer 625 * will never fire while the block is still getting filled 626 * (which is what we want). However, the user could choose 627 * to close a block early and that's fine. 628 * 629 * But when the timer does fire, we check whether or not to refresh it. 630 * Since the tmo granularity is in msecs, it is not too expensive 631 * to refresh the timer, lets say every '8' msecs. 632 * Either the user can set the 'tmo' or we can derive it based on 633 * a) line-speed and b) block-size. 634 * prb_calc_retire_blk_tmo() calculates the tmo. 635 * 636 */ 637 static void prb_retire_rx_blk_timer_expired(struct timer_list *t) 638 { 639 struct packet_sock *po = 640 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer); 641 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 642 unsigned int frozen; 643 struct tpacket_block_desc *pbd; 644 645 spin_lock(&po->sk.sk_receive_queue.lock); 646 647 frozen = prb_queue_frozen(pkc); 648 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 649 650 if (unlikely(pkc->delete_blk_timer)) 651 goto out; 652 653 /* We only need to plug the race when the block is partially filled. 654 * tpacket_rcv: 655 * lock(); increment BLOCK_NUM_PKTS; unlock() 656 * copy_bits() is in progress ... 657 * timer fires on other cpu: 658 * we can't retire the current block because copy_bits 659 * is in progress. 660 * 661 */ 662 if (BLOCK_NUM_PKTS(pbd)) { 663 /* Waiting for skb_copy_bits to finish... */ 664 write_lock(&pkc->blk_fill_in_prog_lock); 665 write_unlock(&pkc->blk_fill_in_prog_lock); 666 } 667 668 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 669 if (!frozen) { 670 if (!BLOCK_NUM_PKTS(pbd)) { 671 /* An empty block. Just refresh the timer. */ 672 goto refresh_timer; 673 } 674 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 675 if (!prb_dispatch_next_block(pkc, po)) 676 goto refresh_timer; 677 else 678 goto out; 679 } else { 680 /* Case 1. Queue was frozen because user-space was 681 * lagging behind. 682 */ 683 if (prb_curr_blk_in_use(pbd)) { 684 /* 685 * Ok, user-space is still behind. 686 * So just refresh the timer. 687 */ 688 goto refresh_timer; 689 } else { 690 /* Case 2. queue was frozen,user-space caught up, 691 * now the link went idle && the timer fired. 692 * We don't have a block to close.So we open this 693 * block and restart the timer. 694 * opening a block thaws the queue,restarts timer 695 * Thawing/timer-refresh is a side effect. 696 */ 697 prb_open_block(pkc, pbd); 698 goto out; 699 } 700 } 701 } 702 703 refresh_timer: 704 _prb_refresh_rx_retire_blk_timer(pkc); 705 706 out: 707 spin_unlock(&po->sk.sk_receive_queue.lock); 708 } 709 710 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 711 struct tpacket_block_desc *pbd1, __u32 status) 712 { 713 /* Flush everything minus the block header */ 714 715 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 716 u8 *start, *end; 717 718 start = (u8 *)pbd1; 719 720 /* Skip the block header(we know header WILL fit in 4K) */ 721 start += PAGE_SIZE; 722 723 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 724 for (; start < end; start += PAGE_SIZE) 725 flush_dcache_page(pgv_to_page(start)); 726 727 smp_wmb(); 728 #endif 729 730 /* Now update the block status. */ 731 732 BLOCK_STATUS(pbd1) = status; 733 734 /* Flush the block header */ 735 736 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 737 start = (u8 *)pbd1; 738 flush_dcache_page(pgv_to_page(start)); 739 740 smp_wmb(); 741 #endif 742 } 743 744 /* 745 * Side effect: 746 * 747 * 1) flush the block 748 * 2) Increment active_blk_num 749 * 750 * Note:We DONT refresh the timer on purpose. 751 * Because almost always the next block will be opened. 752 */ 753 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 754 struct tpacket_block_desc *pbd1, 755 struct packet_sock *po, unsigned int stat) 756 { 757 __u32 status = TP_STATUS_USER | stat; 758 759 struct tpacket3_hdr *last_pkt; 760 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 761 struct sock *sk = &po->sk; 762 763 if (atomic_read(&po->tp_drops)) 764 status |= TP_STATUS_LOSING; 765 766 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 767 last_pkt->tp_next_offset = 0; 768 769 /* Get the ts of the last pkt */ 770 if (BLOCK_NUM_PKTS(pbd1)) { 771 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 772 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 773 } else { 774 /* Ok, we tmo'd - so get the current time. 775 * 776 * It shouldn't really happen as we don't close empty 777 * blocks. See prb_retire_rx_blk_timer_expired(). 778 */ 779 struct timespec64 ts; 780 ktime_get_real_ts64(&ts); 781 h1->ts_last_pkt.ts_sec = ts.tv_sec; 782 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 783 } 784 785 smp_wmb(); 786 787 /* Flush the block */ 788 prb_flush_block(pkc1, pbd1, status); 789 790 sk->sk_data_ready(sk); 791 792 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 793 } 794 795 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 796 { 797 pkc->reset_pending_on_curr_blk = 0; 798 } 799 800 /* 801 * Side effect of opening a block: 802 * 803 * 1) prb_queue is thawed. 804 * 2) retire_blk_timer is refreshed. 805 * 806 */ 807 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 808 struct tpacket_block_desc *pbd1) 809 { 810 struct timespec64 ts; 811 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 812 813 smp_rmb(); 814 815 /* We could have just memset this but we will lose the 816 * flexibility of making the priv area sticky 817 */ 818 819 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 820 BLOCK_NUM_PKTS(pbd1) = 0; 821 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 822 823 ktime_get_real_ts64(&ts); 824 825 h1->ts_first_pkt.ts_sec = ts.tv_sec; 826 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 827 828 pkc1->pkblk_start = (char *)pbd1; 829 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 830 831 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 832 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 833 834 pbd1->version = pkc1->version; 835 pkc1->prev = pkc1->nxt_offset; 836 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 837 838 prb_thaw_queue(pkc1); 839 _prb_refresh_rx_retire_blk_timer(pkc1); 840 841 smp_wmb(); 842 } 843 844 /* 845 * Queue freeze logic: 846 * 1) Assume tp_block_nr = 8 blocks. 847 * 2) At time 't0', user opens Rx ring. 848 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 849 * 4) user-space is either sleeping or processing block '0'. 850 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 851 * it will close block-7,loop around and try to fill block '0'. 852 * call-flow: 853 * __packet_lookup_frame_in_block 854 * prb_retire_current_block() 855 * prb_dispatch_next_block() 856 * |->(BLOCK_STATUS == USER) evaluates to true 857 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 858 * 6) Now there are two cases: 859 * 6.1) Link goes idle right after the queue is frozen. 860 * But remember, the last open_block() refreshed the timer. 861 * When this timer expires,it will refresh itself so that we can 862 * re-open block-0 in near future. 863 * 6.2) Link is busy and keeps on receiving packets. This is a simple 864 * case and __packet_lookup_frame_in_block will check if block-0 865 * is free and can now be re-used. 866 */ 867 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 868 struct packet_sock *po) 869 { 870 pkc->reset_pending_on_curr_blk = 1; 871 po->stats.stats3.tp_freeze_q_cnt++; 872 } 873 874 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 875 876 /* 877 * If the next block is free then we will dispatch it 878 * and return a good offset. 879 * Else, we will freeze the queue. 880 * So, caller must check the return value. 881 */ 882 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 883 struct packet_sock *po) 884 { 885 struct tpacket_block_desc *pbd; 886 887 smp_rmb(); 888 889 /* 1. Get current block num */ 890 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 891 892 /* 2. If this block is currently in_use then freeze the queue */ 893 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 894 prb_freeze_queue(pkc, po); 895 return NULL; 896 } 897 898 /* 899 * 3. 900 * open this block and return the offset where the first packet 901 * needs to get stored. 902 */ 903 prb_open_block(pkc, pbd); 904 return (void *)pkc->nxt_offset; 905 } 906 907 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 908 struct packet_sock *po, unsigned int status) 909 { 910 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 911 912 /* retire/close the current block */ 913 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 914 /* 915 * Plug the case where copy_bits() is in progress on 916 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 917 * have space to copy the pkt in the current block and 918 * called prb_retire_current_block() 919 * 920 * We don't need to worry about the TMO case because 921 * the timer-handler already handled this case. 922 */ 923 if (!(status & TP_STATUS_BLK_TMO)) { 924 /* Waiting for skb_copy_bits to finish... */ 925 write_lock(&pkc->blk_fill_in_prog_lock); 926 write_unlock(&pkc->blk_fill_in_prog_lock); 927 } 928 prb_close_block(pkc, pbd, po, status); 929 return; 930 } 931 } 932 933 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) 934 { 935 return TP_STATUS_USER & BLOCK_STATUS(pbd); 936 } 937 938 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 939 { 940 return pkc->reset_pending_on_curr_blk; 941 } 942 943 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 944 __releases(&pkc->blk_fill_in_prog_lock) 945 { 946 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 947 948 read_unlock(&pkc->blk_fill_in_prog_lock); 949 } 950 951 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 952 struct tpacket3_hdr *ppd) 953 { 954 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 955 } 956 957 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 958 struct tpacket3_hdr *ppd) 959 { 960 ppd->hv1.tp_rxhash = 0; 961 } 962 963 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 964 struct tpacket3_hdr *ppd) 965 { 966 if (skb_vlan_tag_present(pkc->skb)) { 967 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 968 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 969 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 970 } else { 971 ppd->hv1.tp_vlan_tci = 0; 972 ppd->hv1.tp_vlan_tpid = 0; 973 ppd->tp_status = TP_STATUS_AVAILABLE; 974 } 975 } 976 977 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 978 struct tpacket3_hdr *ppd) 979 { 980 ppd->hv1.tp_padding = 0; 981 prb_fill_vlan_info(pkc, ppd); 982 983 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 984 prb_fill_rxhash(pkc, ppd); 985 else 986 prb_clear_rxhash(pkc, ppd); 987 } 988 989 static void prb_fill_curr_block(char *curr, 990 struct tpacket_kbdq_core *pkc, 991 struct tpacket_block_desc *pbd, 992 unsigned int len) 993 __acquires(&pkc->blk_fill_in_prog_lock) 994 { 995 struct tpacket3_hdr *ppd; 996 997 ppd = (struct tpacket3_hdr *)curr; 998 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 999 pkc->prev = curr; 1000 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1001 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1002 BLOCK_NUM_PKTS(pbd) += 1; 1003 read_lock(&pkc->blk_fill_in_prog_lock); 1004 prb_run_all_ft_ops(pkc, ppd); 1005 } 1006 1007 /* Assumes caller has the sk->rx_queue.lock */ 1008 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1009 struct sk_buff *skb, 1010 unsigned int len 1011 ) 1012 { 1013 struct tpacket_kbdq_core *pkc; 1014 struct tpacket_block_desc *pbd; 1015 char *curr, *end; 1016 1017 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1018 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1019 1020 /* Queue is frozen when user space is lagging behind */ 1021 if (prb_queue_frozen(pkc)) { 1022 /* 1023 * Check if that last block which caused the queue to freeze, 1024 * is still in_use by user-space. 1025 */ 1026 if (prb_curr_blk_in_use(pbd)) { 1027 /* Can't record this packet */ 1028 return NULL; 1029 } else { 1030 /* 1031 * Ok, the block was released by user-space. 1032 * Now let's open that block. 1033 * opening a block also thaws the queue. 1034 * Thawing is a side effect. 1035 */ 1036 prb_open_block(pkc, pbd); 1037 } 1038 } 1039 1040 smp_mb(); 1041 curr = pkc->nxt_offset; 1042 pkc->skb = skb; 1043 end = (char *)pbd + pkc->kblk_size; 1044 1045 /* first try the current block */ 1046 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1047 prb_fill_curr_block(curr, pkc, pbd, len); 1048 return (void *)curr; 1049 } 1050 1051 /* Ok, close the current block */ 1052 prb_retire_current_block(pkc, po, 0); 1053 1054 /* Now, try to dispatch the next block */ 1055 curr = (char *)prb_dispatch_next_block(pkc, po); 1056 if (curr) { 1057 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1058 prb_fill_curr_block(curr, pkc, pbd, len); 1059 return (void *)curr; 1060 } 1061 1062 /* 1063 * No free blocks are available.user_space hasn't caught up yet. 1064 * Queue was just frozen and now this packet will get dropped. 1065 */ 1066 return NULL; 1067 } 1068 1069 static void *packet_current_rx_frame(struct packet_sock *po, 1070 struct sk_buff *skb, 1071 int status, unsigned int len) 1072 { 1073 char *curr = NULL; 1074 switch (po->tp_version) { 1075 case TPACKET_V1: 1076 case TPACKET_V2: 1077 curr = packet_lookup_frame(po, &po->rx_ring, 1078 po->rx_ring.head, status); 1079 return curr; 1080 case TPACKET_V3: 1081 return __packet_lookup_frame_in_block(po, skb, len); 1082 default: 1083 WARN(1, "TPACKET version not supported\n"); 1084 BUG(); 1085 return NULL; 1086 } 1087 } 1088 1089 static void *prb_lookup_block(const struct packet_sock *po, 1090 const struct packet_ring_buffer *rb, 1091 unsigned int idx, 1092 int status) 1093 { 1094 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1095 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1096 1097 if (status != BLOCK_STATUS(pbd)) 1098 return NULL; 1099 return pbd; 1100 } 1101 1102 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1103 { 1104 unsigned int prev; 1105 if (rb->prb_bdqc.kactive_blk_num) 1106 prev = rb->prb_bdqc.kactive_blk_num-1; 1107 else 1108 prev = rb->prb_bdqc.knum_blocks-1; 1109 return prev; 1110 } 1111 1112 /* Assumes caller has held the rx_queue.lock */ 1113 static void *__prb_previous_block(struct packet_sock *po, 1114 struct packet_ring_buffer *rb, 1115 int status) 1116 { 1117 unsigned int previous = prb_previous_blk_num(rb); 1118 return prb_lookup_block(po, rb, previous, status); 1119 } 1120 1121 static void *packet_previous_rx_frame(struct packet_sock *po, 1122 struct packet_ring_buffer *rb, 1123 int status) 1124 { 1125 if (po->tp_version <= TPACKET_V2) 1126 return packet_previous_frame(po, rb, status); 1127 1128 return __prb_previous_block(po, rb, status); 1129 } 1130 1131 static void packet_increment_rx_head(struct packet_sock *po, 1132 struct packet_ring_buffer *rb) 1133 { 1134 switch (po->tp_version) { 1135 case TPACKET_V1: 1136 case TPACKET_V2: 1137 return packet_increment_head(rb); 1138 case TPACKET_V3: 1139 default: 1140 WARN(1, "TPACKET version not supported.\n"); 1141 BUG(); 1142 return; 1143 } 1144 } 1145 1146 static void *packet_previous_frame(struct packet_sock *po, 1147 struct packet_ring_buffer *rb, 1148 int status) 1149 { 1150 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1151 return packet_lookup_frame(po, rb, previous, status); 1152 } 1153 1154 static void packet_increment_head(struct packet_ring_buffer *buff) 1155 { 1156 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1157 } 1158 1159 static void packet_inc_pending(struct packet_ring_buffer *rb) 1160 { 1161 this_cpu_inc(*rb->pending_refcnt); 1162 } 1163 1164 static void packet_dec_pending(struct packet_ring_buffer *rb) 1165 { 1166 this_cpu_dec(*rb->pending_refcnt); 1167 } 1168 1169 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1170 { 1171 unsigned int refcnt = 0; 1172 int cpu; 1173 1174 /* We don't use pending refcount in rx_ring. */ 1175 if (rb->pending_refcnt == NULL) 1176 return 0; 1177 1178 for_each_possible_cpu(cpu) 1179 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1180 1181 return refcnt; 1182 } 1183 1184 static int packet_alloc_pending(struct packet_sock *po) 1185 { 1186 po->rx_ring.pending_refcnt = NULL; 1187 1188 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1189 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1190 return -ENOBUFS; 1191 1192 return 0; 1193 } 1194 1195 static void packet_free_pending(struct packet_sock *po) 1196 { 1197 free_percpu(po->tx_ring.pending_refcnt); 1198 } 1199 1200 #define ROOM_POW_OFF 2 1201 #define ROOM_NONE 0x0 1202 #define ROOM_LOW 0x1 1203 #define ROOM_NORMAL 0x2 1204 1205 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) 1206 { 1207 int idx, len; 1208 1209 len = READ_ONCE(po->rx_ring.frame_max) + 1; 1210 idx = READ_ONCE(po->rx_ring.head); 1211 if (pow_off) 1212 idx += len >> pow_off; 1213 if (idx >= len) 1214 idx -= len; 1215 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1216 } 1217 1218 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) 1219 { 1220 int idx, len; 1221 1222 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); 1223 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); 1224 if (pow_off) 1225 idx += len >> pow_off; 1226 if (idx >= len) 1227 idx -= len; 1228 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1229 } 1230 1231 static int __packet_rcv_has_room(const struct packet_sock *po, 1232 const struct sk_buff *skb) 1233 { 1234 const struct sock *sk = &po->sk; 1235 int ret = ROOM_NONE; 1236 1237 if (po->prot_hook.func != tpacket_rcv) { 1238 int rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1239 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1240 - (skb ? skb->truesize : 0); 1241 1242 if (avail > (rcvbuf >> ROOM_POW_OFF)) 1243 return ROOM_NORMAL; 1244 else if (avail > 0) 1245 return ROOM_LOW; 1246 else 1247 return ROOM_NONE; 1248 } 1249 1250 if (po->tp_version == TPACKET_V3) { 1251 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1252 ret = ROOM_NORMAL; 1253 else if (__tpacket_v3_has_room(po, 0)) 1254 ret = ROOM_LOW; 1255 } else { 1256 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1257 ret = ROOM_NORMAL; 1258 else if (__tpacket_has_room(po, 0)) 1259 ret = ROOM_LOW; 1260 } 1261 1262 return ret; 1263 } 1264 1265 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1266 { 1267 int pressure, ret; 1268 1269 ret = __packet_rcv_has_room(po, skb); 1270 pressure = ret != ROOM_NORMAL; 1271 1272 if (READ_ONCE(po->pressure) != pressure) 1273 WRITE_ONCE(po->pressure, pressure); 1274 1275 return ret; 1276 } 1277 1278 static void packet_rcv_try_clear_pressure(struct packet_sock *po) 1279 { 1280 if (READ_ONCE(po->pressure) && 1281 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 1282 WRITE_ONCE(po->pressure, 0); 1283 } 1284 1285 static void packet_sock_destruct(struct sock *sk) 1286 { 1287 skb_queue_purge(&sk->sk_error_queue); 1288 1289 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1290 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1291 1292 if (!sock_flag(sk, SOCK_DEAD)) { 1293 pr_err("Attempt to release alive packet socket: %p\n", sk); 1294 return; 1295 } 1296 1297 sk_refcnt_debug_dec(sk); 1298 } 1299 1300 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1301 { 1302 u32 *history = po->rollover->history; 1303 u32 victim, rxhash; 1304 int i, count = 0; 1305 1306 rxhash = skb_get_hash(skb); 1307 for (i = 0; i < ROLLOVER_HLEN; i++) 1308 if (READ_ONCE(history[i]) == rxhash) 1309 count++; 1310 1311 victim = prandom_u32() % ROLLOVER_HLEN; 1312 1313 /* Avoid dirtying the cache line if possible */ 1314 if (READ_ONCE(history[victim]) != rxhash) 1315 WRITE_ONCE(history[victim], rxhash); 1316 1317 return count > (ROLLOVER_HLEN >> 1); 1318 } 1319 1320 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1321 struct sk_buff *skb, 1322 unsigned int num) 1323 { 1324 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1325 } 1326 1327 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1328 struct sk_buff *skb, 1329 unsigned int num) 1330 { 1331 unsigned int val = atomic_inc_return(&f->rr_cur); 1332 1333 return val % num; 1334 } 1335 1336 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1337 struct sk_buff *skb, 1338 unsigned int num) 1339 { 1340 return smp_processor_id() % num; 1341 } 1342 1343 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1344 struct sk_buff *skb, 1345 unsigned int num) 1346 { 1347 return prandom_u32_max(num); 1348 } 1349 1350 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1351 struct sk_buff *skb, 1352 unsigned int idx, bool try_self, 1353 unsigned int num) 1354 { 1355 struct packet_sock *po, *po_next, *po_skip = NULL; 1356 unsigned int i, j, room = ROOM_NONE; 1357 1358 po = pkt_sk(f->arr[idx]); 1359 1360 if (try_self) { 1361 room = packet_rcv_has_room(po, skb); 1362 if (room == ROOM_NORMAL || 1363 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1364 return idx; 1365 po_skip = po; 1366 } 1367 1368 i = j = min_t(int, po->rollover->sock, num - 1); 1369 do { 1370 po_next = pkt_sk(f->arr[i]); 1371 if (po_next != po_skip && !READ_ONCE(po_next->pressure) && 1372 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1373 if (i != j) 1374 po->rollover->sock = i; 1375 atomic_long_inc(&po->rollover->num); 1376 if (room == ROOM_LOW) 1377 atomic_long_inc(&po->rollover->num_huge); 1378 return i; 1379 } 1380 1381 if (++i == num) 1382 i = 0; 1383 } while (i != j); 1384 1385 atomic_long_inc(&po->rollover->num_failed); 1386 return idx; 1387 } 1388 1389 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1390 struct sk_buff *skb, 1391 unsigned int num) 1392 { 1393 return skb_get_queue_mapping(skb) % num; 1394 } 1395 1396 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1397 struct sk_buff *skb, 1398 unsigned int num) 1399 { 1400 struct bpf_prog *prog; 1401 unsigned int ret = 0; 1402 1403 rcu_read_lock(); 1404 prog = rcu_dereference(f->bpf_prog); 1405 if (prog) 1406 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1407 rcu_read_unlock(); 1408 1409 return ret; 1410 } 1411 1412 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1413 { 1414 return f->flags & (flag >> 8); 1415 } 1416 1417 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1418 struct packet_type *pt, struct net_device *orig_dev) 1419 { 1420 struct packet_fanout *f = pt->af_packet_priv; 1421 unsigned int num = READ_ONCE(f->num_members); 1422 struct net *net = read_pnet(&f->net); 1423 struct packet_sock *po; 1424 unsigned int idx; 1425 1426 if (!net_eq(dev_net(dev), net) || !num) { 1427 kfree_skb(skb); 1428 return 0; 1429 } 1430 1431 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1432 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1433 if (!skb) 1434 return 0; 1435 } 1436 switch (f->type) { 1437 case PACKET_FANOUT_HASH: 1438 default: 1439 idx = fanout_demux_hash(f, skb, num); 1440 break; 1441 case PACKET_FANOUT_LB: 1442 idx = fanout_demux_lb(f, skb, num); 1443 break; 1444 case PACKET_FANOUT_CPU: 1445 idx = fanout_demux_cpu(f, skb, num); 1446 break; 1447 case PACKET_FANOUT_RND: 1448 idx = fanout_demux_rnd(f, skb, num); 1449 break; 1450 case PACKET_FANOUT_QM: 1451 idx = fanout_demux_qm(f, skb, num); 1452 break; 1453 case PACKET_FANOUT_ROLLOVER: 1454 idx = fanout_demux_rollover(f, skb, 0, false, num); 1455 break; 1456 case PACKET_FANOUT_CBPF: 1457 case PACKET_FANOUT_EBPF: 1458 idx = fanout_demux_bpf(f, skb, num); 1459 break; 1460 } 1461 1462 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1463 idx = fanout_demux_rollover(f, skb, idx, true, num); 1464 1465 po = pkt_sk(f->arr[idx]); 1466 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1467 } 1468 1469 DEFINE_MUTEX(fanout_mutex); 1470 EXPORT_SYMBOL_GPL(fanout_mutex); 1471 static LIST_HEAD(fanout_list); 1472 static u16 fanout_next_id; 1473 1474 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1475 { 1476 struct packet_fanout *f = po->fanout; 1477 1478 spin_lock(&f->lock); 1479 f->arr[f->num_members] = sk; 1480 smp_wmb(); 1481 f->num_members++; 1482 if (f->num_members == 1) 1483 dev_add_pack(&f->prot_hook); 1484 spin_unlock(&f->lock); 1485 } 1486 1487 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1488 { 1489 struct packet_fanout *f = po->fanout; 1490 int i; 1491 1492 spin_lock(&f->lock); 1493 for (i = 0; i < f->num_members; i++) { 1494 if (f->arr[i] == sk) 1495 break; 1496 } 1497 BUG_ON(i >= f->num_members); 1498 f->arr[i] = f->arr[f->num_members - 1]; 1499 f->num_members--; 1500 if (f->num_members == 0) 1501 __dev_remove_pack(&f->prot_hook); 1502 spin_unlock(&f->lock); 1503 } 1504 1505 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1506 { 1507 if (sk->sk_family != PF_PACKET) 1508 return false; 1509 1510 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1511 } 1512 1513 static void fanout_init_data(struct packet_fanout *f) 1514 { 1515 switch (f->type) { 1516 case PACKET_FANOUT_LB: 1517 atomic_set(&f->rr_cur, 0); 1518 break; 1519 case PACKET_FANOUT_CBPF: 1520 case PACKET_FANOUT_EBPF: 1521 RCU_INIT_POINTER(f->bpf_prog, NULL); 1522 break; 1523 } 1524 } 1525 1526 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1527 { 1528 struct bpf_prog *old; 1529 1530 spin_lock(&f->lock); 1531 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1532 rcu_assign_pointer(f->bpf_prog, new); 1533 spin_unlock(&f->lock); 1534 1535 if (old) { 1536 synchronize_net(); 1537 bpf_prog_destroy(old); 1538 } 1539 } 1540 1541 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, 1542 unsigned int len) 1543 { 1544 struct bpf_prog *new; 1545 struct sock_fprog fprog; 1546 int ret; 1547 1548 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1549 return -EPERM; 1550 1551 ret = copy_bpf_fprog_from_user(&fprog, data, len); 1552 if (ret) 1553 return ret; 1554 1555 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1556 if (ret) 1557 return ret; 1558 1559 __fanout_set_data_bpf(po->fanout, new); 1560 return 0; 1561 } 1562 1563 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, 1564 unsigned int len) 1565 { 1566 struct bpf_prog *new; 1567 u32 fd; 1568 1569 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1570 return -EPERM; 1571 if (len != sizeof(fd)) 1572 return -EINVAL; 1573 if (copy_from_sockptr(&fd, data, len)) 1574 return -EFAULT; 1575 1576 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1577 if (IS_ERR(new)) 1578 return PTR_ERR(new); 1579 1580 __fanout_set_data_bpf(po->fanout, new); 1581 return 0; 1582 } 1583 1584 static int fanout_set_data(struct packet_sock *po, sockptr_t data, 1585 unsigned int len) 1586 { 1587 switch (po->fanout->type) { 1588 case PACKET_FANOUT_CBPF: 1589 return fanout_set_data_cbpf(po, data, len); 1590 case PACKET_FANOUT_EBPF: 1591 return fanout_set_data_ebpf(po, data, len); 1592 default: 1593 return -EINVAL; 1594 } 1595 } 1596 1597 static void fanout_release_data(struct packet_fanout *f) 1598 { 1599 switch (f->type) { 1600 case PACKET_FANOUT_CBPF: 1601 case PACKET_FANOUT_EBPF: 1602 __fanout_set_data_bpf(f, NULL); 1603 } 1604 } 1605 1606 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1607 { 1608 struct packet_fanout *f; 1609 1610 list_for_each_entry(f, &fanout_list, list) { 1611 if (f->id == candidate_id && 1612 read_pnet(&f->net) == sock_net(sk)) { 1613 return false; 1614 } 1615 } 1616 return true; 1617 } 1618 1619 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1620 { 1621 u16 id = fanout_next_id; 1622 1623 do { 1624 if (__fanout_id_is_free(sk, id)) { 1625 *new_id = id; 1626 fanout_next_id = id + 1; 1627 return true; 1628 } 1629 1630 id++; 1631 } while (id != fanout_next_id); 1632 1633 return false; 1634 } 1635 1636 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1637 { 1638 struct packet_rollover *rollover = NULL; 1639 struct packet_sock *po = pkt_sk(sk); 1640 struct packet_fanout *f, *match; 1641 u8 type = type_flags & 0xff; 1642 u8 flags = type_flags >> 8; 1643 int err; 1644 1645 switch (type) { 1646 case PACKET_FANOUT_ROLLOVER: 1647 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1648 return -EINVAL; 1649 case PACKET_FANOUT_HASH: 1650 case PACKET_FANOUT_LB: 1651 case PACKET_FANOUT_CPU: 1652 case PACKET_FANOUT_RND: 1653 case PACKET_FANOUT_QM: 1654 case PACKET_FANOUT_CBPF: 1655 case PACKET_FANOUT_EBPF: 1656 break; 1657 default: 1658 return -EINVAL; 1659 } 1660 1661 mutex_lock(&fanout_mutex); 1662 1663 err = -EALREADY; 1664 if (po->fanout) 1665 goto out; 1666 1667 if (type == PACKET_FANOUT_ROLLOVER || 1668 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1669 err = -ENOMEM; 1670 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); 1671 if (!rollover) 1672 goto out; 1673 atomic_long_set(&rollover->num, 0); 1674 atomic_long_set(&rollover->num_huge, 0); 1675 atomic_long_set(&rollover->num_failed, 0); 1676 } 1677 1678 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1679 if (id != 0) { 1680 err = -EINVAL; 1681 goto out; 1682 } 1683 if (!fanout_find_new_id(sk, &id)) { 1684 err = -ENOMEM; 1685 goto out; 1686 } 1687 /* ephemeral flag for the first socket in the group: drop it */ 1688 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1689 } 1690 1691 match = NULL; 1692 list_for_each_entry(f, &fanout_list, list) { 1693 if (f->id == id && 1694 read_pnet(&f->net) == sock_net(sk)) { 1695 match = f; 1696 break; 1697 } 1698 } 1699 err = -EINVAL; 1700 if (match && match->flags != flags) 1701 goto out; 1702 if (!match) { 1703 err = -ENOMEM; 1704 match = kzalloc(sizeof(*match), GFP_KERNEL); 1705 if (!match) 1706 goto out; 1707 write_pnet(&match->net, sock_net(sk)); 1708 match->id = id; 1709 match->type = type; 1710 match->flags = flags; 1711 INIT_LIST_HEAD(&match->list); 1712 spin_lock_init(&match->lock); 1713 refcount_set(&match->sk_ref, 0); 1714 fanout_init_data(match); 1715 match->prot_hook.type = po->prot_hook.type; 1716 match->prot_hook.dev = po->prot_hook.dev; 1717 match->prot_hook.func = packet_rcv_fanout; 1718 match->prot_hook.af_packet_priv = match; 1719 match->prot_hook.id_match = match_fanout_group; 1720 list_add(&match->list, &fanout_list); 1721 } 1722 err = -EINVAL; 1723 1724 spin_lock(&po->bind_lock); 1725 if (po->running && 1726 match->type == type && 1727 match->prot_hook.type == po->prot_hook.type && 1728 match->prot_hook.dev == po->prot_hook.dev) { 1729 err = -ENOSPC; 1730 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1731 __dev_remove_pack(&po->prot_hook); 1732 po->fanout = match; 1733 po->rollover = rollover; 1734 rollover = NULL; 1735 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1736 __fanout_link(sk, po); 1737 err = 0; 1738 } 1739 } 1740 spin_unlock(&po->bind_lock); 1741 1742 if (err && !refcount_read(&match->sk_ref)) { 1743 list_del(&match->list); 1744 kfree(match); 1745 } 1746 1747 out: 1748 kfree(rollover); 1749 mutex_unlock(&fanout_mutex); 1750 return err; 1751 } 1752 1753 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1754 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1755 * It is the responsibility of the caller to call fanout_release_data() and 1756 * free the returned packet_fanout (after synchronize_net()) 1757 */ 1758 static struct packet_fanout *fanout_release(struct sock *sk) 1759 { 1760 struct packet_sock *po = pkt_sk(sk); 1761 struct packet_fanout *f; 1762 1763 mutex_lock(&fanout_mutex); 1764 f = po->fanout; 1765 if (f) { 1766 po->fanout = NULL; 1767 1768 if (refcount_dec_and_test(&f->sk_ref)) 1769 list_del(&f->list); 1770 else 1771 f = NULL; 1772 } 1773 mutex_unlock(&fanout_mutex); 1774 1775 return f; 1776 } 1777 1778 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1779 struct sk_buff *skb) 1780 { 1781 /* Earlier code assumed this would be a VLAN pkt, double-check 1782 * this now that we have the actual packet in hand. We can only 1783 * do this check on Ethernet devices. 1784 */ 1785 if (unlikely(dev->type != ARPHRD_ETHER)) 1786 return false; 1787 1788 skb_reset_mac_header(skb); 1789 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1790 } 1791 1792 static const struct proto_ops packet_ops; 1793 1794 static const struct proto_ops packet_ops_spkt; 1795 1796 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1797 struct packet_type *pt, struct net_device *orig_dev) 1798 { 1799 struct sock *sk; 1800 struct sockaddr_pkt *spkt; 1801 1802 /* 1803 * When we registered the protocol we saved the socket in the data 1804 * field for just this event. 1805 */ 1806 1807 sk = pt->af_packet_priv; 1808 1809 /* 1810 * Yank back the headers [hope the device set this 1811 * right or kerboom...] 1812 * 1813 * Incoming packets have ll header pulled, 1814 * push it back. 1815 * 1816 * For outgoing ones skb->data == skb_mac_header(skb) 1817 * so that this procedure is noop. 1818 */ 1819 1820 if (skb->pkt_type == PACKET_LOOPBACK) 1821 goto out; 1822 1823 if (!net_eq(dev_net(dev), sock_net(sk))) 1824 goto out; 1825 1826 skb = skb_share_check(skb, GFP_ATOMIC); 1827 if (skb == NULL) 1828 goto oom; 1829 1830 /* drop any routing info */ 1831 skb_dst_drop(skb); 1832 1833 /* drop conntrack reference */ 1834 nf_reset_ct(skb); 1835 1836 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1837 1838 skb_push(skb, skb->data - skb_mac_header(skb)); 1839 1840 /* 1841 * The SOCK_PACKET socket receives _all_ frames. 1842 */ 1843 1844 spkt->spkt_family = dev->type; 1845 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1846 spkt->spkt_protocol = skb->protocol; 1847 1848 /* 1849 * Charge the memory to the socket. This is done specifically 1850 * to prevent sockets using all the memory up. 1851 */ 1852 1853 if (sock_queue_rcv_skb(sk, skb) == 0) 1854 return 0; 1855 1856 out: 1857 kfree_skb(skb); 1858 oom: 1859 return 0; 1860 } 1861 1862 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1863 { 1864 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1865 sock->type == SOCK_RAW) { 1866 skb_reset_mac_header(skb); 1867 skb->protocol = dev_parse_header_protocol(skb); 1868 } 1869 1870 skb_probe_transport_header(skb); 1871 } 1872 1873 /* 1874 * Output a raw packet to a device layer. This bypasses all the other 1875 * protocol layers and you must therefore supply it with a complete frame 1876 */ 1877 1878 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1879 size_t len) 1880 { 1881 struct sock *sk = sock->sk; 1882 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1883 struct sk_buff *skb = NULL; 1884 struct net_device *dev; 1885 struct sockcm_cookie sockc; 1886 __be16 proto = 0; 1887 int err; 1888 int extra_len = 0; 1889 1890 /* 1891 * Get and verify the address. 1892 */ 1893 1894 if (saddr) { 1895 if (msg->msg_namelen < sizeof(struct sockaddr)) 1896 return -EINVAL; 1897 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1898 proto = saddr->spkt_protocol; 1899 } else 1900 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1901 1902 /* 1903 * Find the device first to size check it 1904 */ 1905 1906 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1907 retry: 1908 rcu_read_lock(); 1909 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1910 err = -ENODEV; 1911 if (dev == NULL) 1912 goto out_unlock; 1913 1914 err = -ENETDOWN; 1915 if (!(dev->flags & IFF_UP)) 1916 goto out_unlock; 1917 1918 /* 1919 * You may not queue a frame bigger than the mtu. This is the lowest level 1920 * raw protocol and you must do your own fragmentation at this level. 1921 */ 1922 1923 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1924 if (!netif_supports_nofcs(dev)) { 1925 err = -EPROTONOSUPPORT; 1926 goto out_unlock; 1927 } 1928 extra_len = 4; /* We're doing our own CRC */ 1929 } 1930 1931 err = -EMSGSIZE; 1932 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1933 goto out_unlock; 1934 1935 if (!skb) { 1936 size_t reserved = LL_RESERVED_SPACE(dev); 1937 int tlen = dev->needed_tailroom; 1938 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1939 1940 rcu_read_unlock(); 1941 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1942 if (skb == NULL) 1943 return -ENOBUFS; 1944 /* FIXME: Save some space for broken drivers that write a hard 1945 * header at transmission time by themselves. PPP is the notable 1946 * one here. This should really be fixed at the driver level. 1947 */ 1948 skb_reserve(skb, reserved); 1949 skb_reset_network_header(skb); 1950 1951 /* Try to align data part correctly */ 1952 if (hhlen) { 1953 skb->data -= hhlen; 1954 skb->tail -= hhlen; 1955 if (len < hhlen) 1956 skb_reset_network_header(skb); 1957 } 1958 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1959 if (err) 1960 goto out_free; 1961 goto retry; 1962 } 1963 1964 if (!dev_validate_header(dev, skb->data, len)) { 1965 err = -EINVAL; 1966 goto out_unlock; 1967 } 1968 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 1969 !packet_extra_vlan_len_allowed(dev, skb)) { 1970 err = -EMSGSIZE; 1971 goto out_unlock; 1972 } 1973 1974 sockcm_init(&sockc, sk); 1975 if (msg->msg_controllen) { 1976 err = sock_cmsg_send(sk, msg, &sockc); 1977 if (unlikely(err)) 1978 goto out_unlock; 1979 } 1980 1981 skb->protocol = proto; 1982 skb->dev = dev; 1983 skb->priority = sk->sk_priority; 1984 skb->mark = sk->sk_mark; 1985 skb->tstamp = sockc.transmit_time; 1986 1987 skb_setup_tx_timestamp(skb, sockc.tsflags); 1988 1989 if (unlikely(extra_len == 4)) 1990 skb->no_fcs = 1; 1991 1992 packet_parse_headers(skb, sock); 1993 1994 dev_queue_xmit(skb); 1995 rcu_read_unlock(); 1996 return len; 1997 1998 out_unlock: 1999 rcu_read_unlock(); 2000 out_free: 2001 kfree_skb(skb); 2002 return err; 2003 } 2004 2005 static unsigned int run_filter(struct sk_buff *skb, 2006 const struct sock *sk, 2007 unsigned int res) 2008 { 2009 struct sk_filter *filter; 2010 2011 rcu_read_lock(); 2012 filter = rcu_dereference(sk->sk_filter); 2013 if (filter != NULL) 2014 res = bpf_prog_run_clear_cb(filter->prog, skb); 2015 rcu_read_unlock(); 2016 2017 return res; 2018 } 2019 2020 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2021 size_t *len) 2022 { 2023 struct virtio_net_hdr vnet_hdr; 2024 2025 if (*len < sizeof(vnet_hdr)) 2026 return -EINVAL; 2027 *len -= sizeof(vnet_hdr); 2028 2029 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0)) 2030 return -EINVAL; 2031 2032 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr)); 2033 } 2034 2035 /* 2036 * This function makes lazy skb cloning in hope that most of packets 2037 * are discarded by BPF. 2038 * 2039 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2040 * and skb->cb are mangled. It works because (and until) packets 2041 * falling here are owned by current CPU. Output packets are cloned 2042 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2043 * sequencially, so that if we return skb to original state on exit, 2044 * we will not harm anyone. 2045 */ 2046 2047 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2048 struct packet_type *pt, struct net_device *orig_dev) 2049 { 2050 struct sock *sk; 2051 struct sockaddr_ll *sll; 2052 struct packet_sock *po; 2053 u8 *skb_head = skb->data; 2054 int skb_len = skb->len; 2055 unsigned int snaplen, res; 2056 bool is_drop_n_account = false; 2057 2058 if (skb->pkt_type == PACKET_LOOPBACK) 2059 goto drop; 2060 2061 sk = pt->af_packet_priv; 2062 po = pkt_sk(sk); 2063 2064 if (!net_eq(dev_net(dev), sock_net(sk))) 2065 goto drop; 2066 2067 skb->dev = dev; 2068 2069 if (dev->header_ops) { 2070 /* The device has an explicit notion of ll header, 2071 * exported to higher levels. 2072 * 2073 * Otherwise, the device hides details of its frame 2074 * structure, so that corresponding packet head is 2075 * never delivered to user. 2076 */ 2077 if (sk->sk_type != SOCK_DGRAM) 2078 skb_push(skb, skb->data - skb_mac_header(skb)); 2079 else if (skb->pkt_type == PACKET_OUTGOING) { 2080 /* Special case: outgoing packets have ll header at head */ 2081 skb_pull(skb, skb_network_offset(skb)); 2082 } 2083 } 2084 2085 snaplen = skb->len; 2086 2087 res = run_filter(skb, sk, snaplen); 2088 if (!res) 2089 goto drop_n_restore; 2090 if (snaplen > res) 2091 snaplen = res; 2092 2093 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2094 goto drop_n_acct; 2095 2096 if (skb_shared(skb)) { 2097 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2098 if (nskb == NULL) 2099 goto drop_n_acct; 2100 2101 if (skb_head != skb->data) { 2102 skb->data = skb_head; 2103 skb->len = skb_len; 2104 } 2105 consume_skb(skb); 2106 skb = nskb; 2107 } 2108 2109 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2110 2111 sll = &PACKET_SKB_CB(skb)->sa.ll; 2112 sll->sll_hatype = dev->type; 2113 sll->sll_pkttype = skb->pkt_type; 2114 if (unlikely(po->origdev)) 2115 sll->sll_ifindex = orig_dev->ifindex; 2116 else 2117 sll->sll_ifindex = dev->ifindex; 2118 2119 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2120 2121 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2122 * Use their space for storing the original skb length. 2123 */ 2124 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2125 2126 if (pskb_trim(skb, snaplen)) 2127 goto drop_n_acct; 2128 2129 skb_set_owner_r(skb, sk); 2130 skb->dev = NULL; 2131 skb_dst_drop(skb); 2132 2133 /* drop conntrack reference */ 2134 nf_reset_ct(skb); 2135 2136 spin_lock(&sk->sk_receive_queue.lock); 2137 po->stats.stats1.tp_packets++; 2138 sock_skb_set_dropcount(sk, skb); 2139 __skb_queue_tail(&sk->sk_receive_queue, skb); 2140 spin_unlock(&sk->sk_receive_queue.lock); 2141 sk->sk_data_ready(sk); 2142 return 0; 2143 2144 drop_n_acct: 2145 is_drop_n_account = true; 2146 atomic_inc(&po->tp_drops); 2147 atomic_inc(&sk->sk_drops); 2148 2149 drop_n_restore: 2150 if (skb_head != skb->data && skb_shared(skb)) { 2151 skb->data = skb_head; 2152 skb->len = skb_len; 2153 } 2154 drop: 2155 if (!is_drop_n_account) 2156 consume_skb(skb); 2157 else 2158 kfree_skb(skb); 2159 return 0; 2160 } 2161 2162 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2163 struct packet_type *pt, struct net_device *orig_dev) 2164 { 2165 struct sock *sk; 2166 struct packet_sock *po; 2167 struct sockaddr_ll *sll; 2168 union tpacket_uhdr h; 2169 u8 *skb_head = skb->data; 2170 int skb_len = skb->len; 2171 unsigned int snaplen, res; 2172 unsigned long status = TP_STATUS_USER; 2173 unsigned short macoff, hdrlen; 2174 unsigned int netoff; 2175 struct sk_buff *copy_skb = NULL; 2176 struct timespec64 ts; 2177 __u32 ts_status; 2178 bool is_drop_n_account = false; 2179 unsigned int slot_id = 0; 2180 bool do_vnet = false; 2181 2182 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2183 * We may add members to them until current aligned size without forcing 2184 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2185 */ 2186 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2187 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2188 2189 if (skb->pkt_type == PACKET_LOOPBACK) 2190 goto drop; 2191 2192 sk = pt->af_packet_priv; 2193 po = pkt_sk(sk); 2194 2195 if (!net_eq(dev_net(dev), sock_net(sk))) 2196 goto drop; 2197 2198 if (dev->header_ops) { 2199 if (sk->sk_type != SOCK_DGRAM) 2200 skb_push(skb, skb->data - skb_mac_header(skb)); 2201 else if (skb->pkt_type == PACKET_OUTGOING) { 2202 /* Special case: outgoing packets have ll header at head */ 2203 skb_pull(skb, skb_network_offset(skb)); 2204 } 2205 } 2206 2207 snaplen = skb->len; 2208 2209 res = run_filter(skb, sk, snaplen); 2210 if (!res) 2211 goto drop_n_restore; 2212 2213 /* If we are flooded, just give up */ 2214 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2215 atomic_inc(&po->tp_drops); 2216 goto drop_n_restore; 2217 } 2218 2219 if (skb->ip_summed == CHECKSUM_PARTIAL) 2220 status |= TP_STATUS_CSUMNOTREADY; 2221 else if (skb->pkt_type != PACKET_OUTGOING && 2222 (skb->ip_summed == CHECKSUM_COMPLETE || 2223 skb_csum_unnecessary(skb))) 2224 status |= TP_STATUS_CSUM_VALID; 2225 2226 if (snaplen > res) 2227 snaplen = res; 2228 2229 if (sk->sk_type == SOCK_DGRAM) { 2230 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2231 po->tp_reserve; 2232 } else { 2233 unsigned int maclen = skb_network_offset(skb); 2234 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2235 (maclen < 16 ? 16 : maclen)) + 2236 po->tp_reserve; 2237 if (po->has_vnet_hdr) { 2238 netoff += sizeof(struct virtio_net_hdr); 2239 do_vnet = true; 2240 } 2241 macoff = netoff - maclen; 2242 } 2243 if (netoff > USHRT_MAX) { 2244 atomic_inc(&po->tp_drops); 2245 goto drop_n_restore; 2246 } 2247 if (po->tp_version <= TPACKET_V2) { 2248 if (macoff + snaplen > po->rx_ring.frame_size) { 2249 if (po->copy_thresh && 2250 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2251 if (skb_shared(skb)) { 2252 copy_skb = skb_clone(skb, GFP_ATOMIC); 2253 } else { 2254 copy_skb = skb_get(skb); 2255 skb_head = skb->data; 2256 } 2257 if (copy_skb) 2258 skb_set_owner_r(copy_skb, sk); 2259 } 2260 snaplen = po->rx_ring.frame_size - macoff; 2261 if ((int)snaplen < 0) { 2262 snaplen = 0; 2263 do_vnet = false; 2264 } 2265 } 2266 } else if (unlikely(macoff + snaplen > 2267 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2268 u32 nval; 2269 2270 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2271 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2272 snaplen, nval, macoff); 2273 snaplen = nval; 2274 if (unlikely((int)snaplen < 0)) { 2275 snaplen = 0; 2276 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2277 do_vnet = false; 2278 } 2279 } 2280 spin_lock(&sk->sk_receive_queue.lock); 2281 h.raw = packet_current_rx_frame(po, skb, 2282 TP_STATUS_KERNEL, (macoff+snaplen)); 2283 if (!h.raw) 2284 goto drop_n_account; 2285 2286 if (po->tp_version <= TPACKET_V2) { 2287 slot_id = po->rx_ring.head; 2288 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2289 goto drop_n_account; 2290 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2291 } 2292 2293 if (do_vnet && 2294 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2295 sizeof(struct virtio_net_hdr), 2296 vio_le(), true, 0)) { 2297 if (po->tp_version == TPACKET_V3) 2298 prb_clear_blk_fill_status(&po->rx_ring); 2299 goto drop_n_account; 2300 } 2301 2302 if (po->tp_version <= TPACKET_V2) { 2303 packet_increment_rx_head(po, &po->rx_ring); 2304 /* 2305 * LOSING will be reported till you read the stats, 2306 * because it's COR - Clear On Read. 2307 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2308 * at packet level. 2309 */ 2310 if (atomic_read(&po->tp_drops)) 2311 status |= TP_STATUS_LOSING; 2312 } 2313 2314 po->stats.stats1.tp_packets++; 2315 if (copy_skb) { 2316 status |= TP_STATUS_COPY; 2317 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2318 } 2319 spin_unlock(&sk->sk_receive_queue.lock); 2320 2321 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2322 2323 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 2324 ktime_get_real_ts64(&ts); 2325 2326 status |= ts_status; 2327 2328 switch (po->tp_version) { 2329 case TPACKET_V1: 2330 h.h1->tp_len = skb->len; 2331 h.h1->tp_snaplen = snaplen; 2332 h.h1->tp_mac = macoff; 2333 h.h1->tp_net = netoff; 2334 h.h1->tp_sec = ts.tv_sec; 2335 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2336 hdrlen = sizeof(*h.h1); 2337 break; 2338 case TPACKET_V2: 2339 h.h2->tp_len = skb->len; 2340 h.h2->tp_snaplen = snaplen; 2341 h.h2->tp_mac = macoff; 2342 h.h2->tp_net = netoff; 2343 h.h2->tp_sec = ts.tv_sec; 2344 h.h2->tp_nsec = ts.tv_nsec; 2345 if (skb_vlan_tag_present(skb)) { 2346 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2347 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2348 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2349 } else { 2350 h.h2->tp_vlan_tci = 0; 2351 h.h2->tp_vlan_tpid = 0; 2352 } 2353 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2354 hdrlen = sizeof(*h.h2); 2355 break; 2356 case TPACKET_V3: 2357 /* tp_nxt_offset,vlan are already populated above. 2358 * So DONT clear those fields here 2359 */ 2360 h.h3->tp_status |= status; 2361 h.h3->tp_len = skb->len; 2362 h.h3->tp_snaplen = snaplen; 2363 h.h3->tp_mac = macoff; 2364 h.h3->tp_net = netoff; 2365 h.h3->tp_sec = ts.tv_sec; 2366 h.h3->tp_nsec = ts.tv_nsec; 2367 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2368 hdrlen = sizeof(*h.h3); 2369 break; 2370 default: 2371 BUG(); 2372 } 2373 2374 sll = h.raw + TPACKET_ALIGN(hdrlen); 2375 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2376 sll->sll_family = AF_PACKET; 2377 sll->sll_hatype = dev->type; 2378 sll->sll_protocol = skb->protocol; 2379 sll->sll_pkttype = skb->pkt_type; 2380 if (unlikely(po->origdev)) 2381 sll->sll_ifindex = orig_dev->ifindex; 2382 else 2383 sll->sll_ifindex = dev->ifindex; 2384 2385 smp_mb(); 2386 2387 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2388 if (po->tp_version <= TPACKET_V2) { 2389 u8 *start, *end; 2390 2391 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2392 macoff + snaplen); 2393 2394 for (start = h.raw; start < end; start += PAGE_SIZE) 2395 flush_dcache_page(pgv_to_page(start)); 2396 } 2397 smp_wmb(); 2398 #endif 2399 2400 if (po->tp_version <= TPACKET_V2) { 2401 spin_lock(&sk->sk_receive_queue.lock); 2402 __packet_set_status(po, h.raw, status); 2403 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2404 spin_unlock(&sk->sk_receive_queue.lock); 2405 sk->sk_data_ready(sk); 2406 } else if (po->tp_version == TPACKET_V3) { 2407 prb_clear_blk_fill_status(&po->rx_ring); 2408 } 2409 2410 drop_n_restore: 2411 if (skb_head != skb->data && skb_shared(skb)) { 2412 skb->data = skb_head; 2413 skb->len = skb_len; 2414 } 2415 drop: 2416 if (!is_drop_n_account) 2417 consume_skb(skb); 2418 else 2419 kfree_skb(skb); 2420 return 0; 2421 2422 drop_n_account: 2423 spin_unlock(&sk->sk_receive_queue.lock); 2424 atomic_inc(&po->tp_drops); 2425 is_drop_n_account = true; 2426 2427 sk->sk_data_ready(sk); 2428 kfree_skb(copy_skb); 2429 goto drop_n_restore; 2430 } 2431 2432 static void tpacket_destruct_skb(struct sk_buff *skb) 2433 { 2434 struct packet_sock *po = pkt_sk(skb->sk); 2435 2436 if (likely(po->tx_ring.pg_vec)) { 2437 void *ph; 2438 __u32 ts; 2439 2440 ph = skb_zcopy_get_nouarg(skb); 2441 packet_dec_pending(&po->tx_ring); 2442 2443 ts = __packet_set_timestamp(po, ph, skb); 2444 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2445 2446 if (!packet_read_pending(&po->tx_ring)) 2447 complete(&po->skb_completion); 2448 } 2449 2450 sock_wfree(skb); 2451 } 2452 2453 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2454 { 2455 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2456 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2457 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2458 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2459 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2460 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2461 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2462 2463 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2464 return -EINVAL; 2465 2466 return 0; 2467 } 2468 2469 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2470 struct virtio_net_hdr *vnet_hdr) 2471 { 2472 if (*len < sizeof(*vnet_hdr)) 2473 return -EINVAL; 2474 *len -= sizeof(*vnet_hdr); 2475 2476 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2477 return -EFAULT; 2478 2479 return __packet_snd_vnet_parse(vnet_hdr, *len); 2480 } 2481 2482 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2483 void *frame, struct net_device *dev, void *data, int tp_len, 2484 __be16 proto, unsigned char *addr, int hlen, int copylen, 2485 const struct sockcm_cookie *sockc) 2486 { 2487 union tpacket_uhdr ph; 2488 int to_write, offset, len, nr_frags, len_max; 2489 struct socket *sock = po->sk.sk_socket; 2490 struct page *page; 2491 int err; 2492 2493 ph.raw = frame; 2494 2495 skb->protocol = proto; 2496 skb->dev = dev; 2497 skb->priority = po->sk.sk_priority; 2498 skb->mark = po->sk.sk_mark; 2499 skb->tstamp = sockc->transmit_time; 2500 skb_setup_tx_timestamp(skb, sockc->tsflags); 2501 skb_zcopy_set_nouarg(skb, ph.raw); 2502 2503 skb_reserve(skb, hlen); 2504 skb_reset_network_header(skb); 2505 2506 to_write = tp_len; 2507 2508 if (sock->type == SOCK_DGRAM) { 2509 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2510 NULL, tp_len); 2511 if (unlikely(err < 0)) 2512 return -EINVAL; 2513 } else if (copylen) { 2514 int hdrlen = min_t(int, copylen, tp_len); 2515 2516 skb_push(skb, dev->hard_header_len); 2517 skb_put(skb, copylen - dev->hard_header_len); 2518 err = skb_store_bits(skb, 0, data, hdrlen); 2519 if (unlikely(err)) 2520 return err; 2521 if (!dev_validate_header(dev, skb->data, hdrlen)) 2522 return -EINVAL; 2523 2524 data += hdrlen; 2525 to_write -= hdrlen; 2526 } 2527 2528 offset = offset_in_page(data); 2529 len_max = PAGE_SIZE - offset; 2530 len = ((to_write > len_max) ? len_max : to_write); 2531 2532 skb->data_len = to_write; 2533 skb->len += to_write; 2534 skb->truesize += to_write; 2535 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2536 2537 while (likely(to_write)) { 2538 nr_frags = skb_shinfo(skb)->nr_frags; 2539 2540 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2541 pr_err("Packet exceed the number of skb frags(%lu)\n", 2542 MAX_SKB_FRAGS); 2543 return -EFAULT; 2544 } 2545 2546 page = pgv_to_page(data); 2547 data += len; 2548 flush_dcache_page(page); 2549 get_page(page); 2550 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2551 to_write -= len; 2552 offset = 0; 2553 len_max = PAGE_SIZE; 2554 len = ((to_write > len_max) ? len_max : to_write); 2555 } 2556 2557 packet_parse_headers(skb, sock); 2558 2559 return tp_len; 2560 } 2561 2562 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2563 int size_max, void **data) 2564 { 2565 union tpacket_uhdr ph; 2566 int tp_len, off; 2567 2568 ph.raw = frame; 2569 2570 switch (po->tp_version) { 2571 case TPACKET_V3: 2572 if (ph.h3->tp_next_offset != 0) { 2573 pr_warn_once("variable sized slot not supported"); 2574 return -EINVAL; 2575 } 2576 tp_len = ph.h3->tp_len; 2577 break; 2578 case TPACKET_V2: 2579 tp_len = ph.h2->tp_len; 2580 break; 2581 default: 2582 tp_len = ph.h1->tp_len; 2583 break; 2584 } 2585 if (unlikely(tp_len > size_max)) { 2586 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2587 return -EMSGSIZE; 2588 } 2589 2590 if (unlikely(po->tp_tx_has_off)) { 2591 int off_min, off_max; 2592 2593 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2594 off_max = po->tx_ring.frame_size - tp_len; 2595 if (po->sk.sk_type == SOCK_DGRAM) { 2596 switch (po->tp_version) { 2597 case TPACKET_V3: 2598 off = ph.h3->tp_net; 2599 break; 2600 case TPACKET_V2: 2601 off = ph.h2->tp_net; 2602 break; 2603 default: 2604 off = ph.h1->tp_net; 2605 break; 2606 } 2607 } else { 2608 switch (po->tp_version) { 2609 case TPACKET_V3: 2610 off = ph.h3->tp_mac; 2611 break; 2612 case TPACKET_V2: 2613 off = ph.h2->tp_mac; 2614 break; 2615 default: 2616 off = ph.h1->tp_mac; 2617 break; 2618 } 2619 } 2620 if (unlikely((off < off_min) || (off_max < off))) 2621 return -EINVAL; 2622 } else { 2623 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2624 } 2625 2626 *data = frame + off; 2627 return tp_len; 2628 } 2629 2630 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2631 { 2632 struct sk_buff *skb = NULL; 2633 struct net_device *dev; 2634 struct virtio_net_hdr *vnet_hdr = NULL; 2635 struct sockcm_cookie sockc; 2636 __be16 proto; 2637 int err, reserve = 0; 2638 void *ph; 2639 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2640 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2641 unsigned char *addr = NULL; 2642 int tp_len, size_max; 2643 void *data; 2644 int len_sum = 0; 2645 int status = TP_STATUS_AVAILABLE; 2646 int hlen, tlen, copylen = 0; 2647 long timeo = 0; 2648 2649 mutex_lock(&po->pg_vec_lock); 2650 2651 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2652 * we need to confirm it under protection of pg_vec_lock. 2653 */ 2654 if (unlikely(!po->tx_ring.pg_vec)) { 2655 err = -EBUSY; 2656 goto out; 2657 } 2658 if (likely(saddr == NULL)) { 2659 dev = packet_cached_dev_get(po); 2660 proto = po->num; 2661 } else { 2662 err = -EINVAL; 2663 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2664 goto out; 2665 if (msg->msg_namelen < (saddr->sll_halen 2666 + offsetof(struct sockaddr_ll, 2667 sll_addr))) 2668 goto out; 2669 proto = saddr->sll_protocol; 2670 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2671 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2672 if (dev && msg->msg_namelen < dev->addr_len + 2673 offsetof(struct sockaddr_ll, sll_addr)) 2674 goto out_put; 2675 addr = saddr->sll_addr; 2676 } 2677 } 2678 2679 err = -ENXIO; 2680 if (unlikely(dev == NULL)) 2681 goto out; 2682 err = -ENETDOWN; 2683 if (unlikely(!(dev->flags & IFF_UP))) 2684 goto out_put; 2685 2686 sockcm_init(&sockc, &po->sk); 2687 if (msg->msg_controllen) { 2688 err = sock_cmsg_send(&po->sk, msg, &sockc); 2689 if (unlikely(err)) 2690 goto out_put; 2691 } 2692 2693 if (po->sk.sk_socket->type == SOCK_RAW) 2694 reserve = dev->hard_header_len; 2695 size_max = po->tx_ring.frame_size 2696 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2697 2698 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr) 2699 size_max = dev->mtu + reserve + VLAN_HLEN; 2700 2701 reinit_completion(&po->skb_completion); 2702 2703 do { 2704 ph = packet_current_frame(po, &po->tx_ring, 2705 TP_STATUS_SEND_REQUEST); 2706 if (unlikely(ph == NULL)) { 2707 if (need_wait && skb) { 2708 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2709 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2710 if (timeo <= 0) { 2711 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2712 goto out_put; 2713 } 2714 } 2715 /* check for additional frames */ 2716 continue; 2717 } 2718 2719 skb = NULL; 2720 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2721 if (tp_len < 0) 2722 goto tpacket_error; 2723 2724 status = TP_STATUS_SEND_REQUEST; 2725 hlen = LL_RESERVED_SPACE(dev); 2726 tlen = dev->needed_tailroom; 2727 if (po->has_vnet_hdr) { 2728 vnet_hdr = data; 2729 data += sizeof(*vnet_hdr); 2730 tp_len -= sizeof(*vnet_hdr); 2731 if (tp_len < 0 || 2732 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2733 tp_len = -EINVAL; 2734 goto tpacket_error; 2735 } 2736 copylen = __virtio16_to_cpu(vio_le(), 2737 vnet_hdr->hdr_len); 2738 } 2739 copylen = max_t(int, copylen, dev->hard_header_len); 2740 skb = sock_alloc_send_skb(&po->sk, 2741 hlen + tlen + sizeof(struct sockaddr_ll) + 2742 (copylen - dev->hard_header_len), 2743 !need_wait, &err); 2744 2745 if (unlikely(skb == NULL)) { 2746 /* we assume the socket was initially writeable ... */ 2747 if (likely(len_sum > 0)) 2748 err = len_sum; 2749 goto out_status; 2750 } 2751 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2752 addr, hlen, copylen, &sockc); 2753 if (likely(tp_len >= 0) && 2754 tp_len > dev->mtu + reserve && 2755 !po->has_vnet_hdr && 2756 !packet_extra_vlan_len_allowed(dev, skb)) 2757 tp_len = -EMSGSIZE; 2758 2759 if (unlikely(tp_len < 0)) { 2760 tpacket_error: 2761 if (po->tp_loss) { 2762 __packet_set_status(po, ph, 2763 TP_STATUS_AVAILABLE); 2764 packet_increment_head(&po->tx_ring); 2765 kfree_skb(skb); 2766 continue; 2767 } else { 2768 status = TP_STATUS_WRONG_FORMAT; 2769 err = tp_len; 2770 goto out_status; 2771 } 2772 } 2773 2774 if (po->has_vnet_hdr) { 2775 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { 2776 tp_len = -EINVAL; 2777 goto tpacket_error; 2778 } 2779 virtio_net_hdr_set_proto(skb, vnet_hdr); 2780 } 2781 2782 skb->destructor = tpacket_destruct_skb; 2783 __packet_set_status(po, ph, TP_STATUS_SENDING); 2784 packet_inc_pending(&po->tx_ring); 2785 2786 status = TP_STATUS_SEND_REQUEST; 2787 err = po->xmit(skb); 2788 if (unlikely(err > 0)) { 2789 err = net_xmit_errno(err); 2790 if (err && __packet_get_status(po, ph) == 2791 TP_STATUS_AVAILABLE) { 2792 /* skb was destructed already */ 2793 skb = NULL; 2794 goto out_status; 2795 } 2796 /* 2797 * skb was dropped but not destructed yet; 2798 * let's treat it like congestion or err < 0 2799 */ 2800 err = 0; 2801 } 2802 packet_increment_head(&po->tx_ring); 2803 len_sum += tp_len; 2804 } while (likely((ph != NULL) || 2805 /* Note: packet_read_pending() might be slow if we have 2806 * to call it as it's per_cpu variable, but in fast-path 2807 * we already short-circuit the loop with the first 2808 * condition, and luckily don't have to go that path 2809 * anyway. 2810 */ 2811 (need_wait && packet_read_pending(&po->tx_ring)))); 2812 2813 err = len_sum; 2814 goto out_put; 2815 2816 out_status: 2817 __packet_set_status(po, ph, status); 2818 kfree_skb(skb); 2819 out_put: 2820 dev_put(dev); 2821 out: 2822 mutex_unlock(&po->pg_vec_lock); 2823 return err; 2824 } 2825 2826 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2827 size_t reserve, size_t len, 2828 size_t linear, int noblock, 2829 int *err) 2830 { 2831 struct sk_buff *skb; 2832 2833 /* Under a page? Don't bother with paged skb. */ 2834 if (prepad + len < PAGE_SIZE || !linear) 2835 linear = len; 2836 2837 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2838 err, 0); 2839 if (!skb) 2840 return NULL; 2841 2842 skb_reserve(skb, reserve); 2843 skb_put(skb, linear); 2844 skb->data_len = len - linear; 2845 skb->len += len - linear; 2846 2847 return skb; 2848 } 2849 2850 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2851 { 2852 struct sock *sk = sock->sk; 2853 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2854 struct sk_buff *skb; 2855 struct net_device *dev; 2856 __be16 proto; 2857 unsigned char *addr = NULL; 2858 int err, reserve = 0; 2859 struct sockcm_cookie sockc; 2860 struct virtio_net_hdr vnet_hdr = { 0 }; 2861 int offset = 0; 2862 struct packet_sock *po = pkt_sk(sk); 2863 bool has_vnet_hdr = false; 2864 int hlen, tlen, linear; 2865 int extra_len = 0; 2866 2867 /* 2868 * Get and verify the address. 2869 */ 2870 2871 if (likely(saddr == NULL)) { 2872 dev = packet_cached_dev_get(po); 2873 proto = po->num; 2874 } else { 2875 err = -EINVAL; 2876 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2877 goto out; 2878 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2879 goto out; 2880 proto = saddr->sll_protocol; 2881 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2882 if (sock->type == SOCK_DGRAM) { 2883 if (dev && msg->msg_namelen < dev->addr_len + 2884 offsetof(struct sockaddr_ll, sll_addr)) 2885 goto out_unlock; 2886 addr = saddr->sll_addr; 2887 } 2888 } 2889 2890 err = -ENXIO; 2891 if (unlikely(dev == NULL)) 2892 goto out_unlock; 2893 err = -ENETDOWN; 2894 if (unlikely(!(dev->flags & IFF_UP))) 2895 goto out_unlock; 2896 2897 sockcm_init(&sockc, sk); 2898 sockc.mark = sk->sk_mark; 2899 if (msg->msg_controllen) { 2900 err = sock_cmsg_send(sk, msg, &sockc); 2901 if (unlikely(err)) 2902 goto out_unlock; 2903 } 2904 2905 if (sock->type == SOCK_RAW) 2906 reserve = dev->hard_header_len; 2907 if (po->has_vnet_hdr) { 2908 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); 2909 if (err) 2910 goto out_unlock; 2911 has_vnet_hdr = true; 2912 } 2913 2914 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2915 if (!netif_supports_nofcs(dev)) { 2916 err = -EPROTONOSUPPORT; 2917 goto out_unlock; 2918 } 2919 extra_len = 4; /* We're doing our own CRC */ 2920 } 2921 2922 err = -EMSGSIZE; 2923 if (!vnet_hdr.gso_type && 2924 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2925 goto out_unlock; 2926 2927 err = -ENOBUFS; 2928 hlen = LL_RESERVED_SPACE(dev); 2929 tlen = dev->needed_tailroom; 2930 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 2931 linear = max(linear, min_t(int, len, dev->hard_header_len)); 2932 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 2933 msg->msg_flags & MSG_DONTWAIT, &err); 2934 if (skb == NULL) 2935 goto out_unlock; 2936 2937 skb_reset_network_header(skb); 2938 2939 err = -EINVAL; 2940 if (sock->type == SOCK_DGRAM) { 2941 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2942 if (unlikely(offset < 0)) 2943 goto out_free; 2944 } else if (reserve) { 2945 skb_reserve(skb, -reserve); 2946 if (len < reserve + sizeof(struct ipv6hdr) && 2947 dev->min_header_len != dev->hard_header_len) 2948 skb_reset_network_header(skb); 2949 } 2950 2951 /* Returns -EFAULT on error */ 2952 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2953 if (err) 2954 goto out_free; 2955 2956 if (sock->type == SOCK_RAW && 2957 !dev_validate_header(dev, skb->data, len)) { 2958 err = -EINVAL; 2959 goto out_free; 2960 } 2961 2962 skb_setup_tx_timestamp(skb, sockc.tsflags); 2963 2964 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 2965 !packet_extra_vlan_len_allowed(dev, skb)) { 2966 err = -EMSGSIZE; 2967 goto out_free; 2968 } 2969 2970 skb->protocol = proto; 2971 skb->dev = dev; 2972 skb->priority = sk->sk_priority; 2973 skb->mark = sockc.mark; 2974 skb->tstamp = sockc.transmit_time; 2975 2976 if (has_vnet_hdr) { 2977 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 2978 if (err) 2979 goto out_free; 2980 len += sizeof(vnet_hdr); 2981 virtio_net_hdr_set_proto(skb, &vnet_hdr); 2982 } 2983 2984 packet_parse_headers(skb, sock); 2985 2986 if (unlikely(extra_len == 4)) 2987 skb->no_fcs = 1; 2988 2989 err = po->xmit(skb); 2990 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2991 goto out_unlock; 2992 2993 dev_put(dev); 2994 2995 return len; 2996 2997 out_free: 2998 kfree_skb(skb); 2999 out_unlock: 3000 if (dev) 3001 dev_put(dev); 3002 out: 3003 return err; 3004 } 3005 3006 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3007 { 3008 struct sock *sk = sock->sk; 3009 struct packet_sock *po = pkt_sk(sk); 3010 3011 if (po->tx_ring.pg_vec) 3012 return tpacket_snd(po, msg); 3013 else 3014 return packet_snd(sock, msg, len); 3015 } 3016 3017 /* 3018 * Close a PACKET socket. This is fairly simple. We immediately go 3019 * to 'closed' state and remove our protocol entry in the device list. 3020 */ 3021 3022 static int packet_release(struct socket *sock) 3023 { 3024 struct sock *sk = sock->sk; 3025 struct packet_sock *po; 3026 struct packet_fanout *f; 3027 struct net *net; 3028 union tpacket_req_u req_u; 3029 3030 if (!sk) 3031 return 0; 3032 3033 net = sock_net(sk); 3034 po = pkt_sk(sk); 3035 3036 mutex_lock(&net->packet.sklist_lock); 3037 sk_del_node_init_rcu(sk); 3038 mutex_unlock(&net->packet.sklist_lock); 3039 3040 preempt_disable(); 3041 sock_prot_inuse_add(net, sk->sk_prot, -1); 3042 preempt_enable(); 3043 3044 spin_lock(&po->bind_lock); 3045 unregister_prot_hook(sk, false); 3046 packet_cached_dev_reset(po); 3047 3048 if (po->prot_hook.dev) { 3049 dev_put(po->prot_hook.dev); 3050 po->prot_hook.dev = NULL; 3051 } 3052 spin_unlock(&po->bind_lock); 3053 3054 packet_flush_mclist(sk); 3055 3056 lock_sock(sk); 3057 if (po->rx_ring.pg_vec) { 3058 memset(&req_u, 0, sizeof(req_u)); 3059 packet_set_ring(sk, &req_u, 1, 0); 3060 } 3061 3062 if (po->tx_ring.pg_vec) { 3063 memset(&req_u, 0, sizeof(req_u)); 3064 packet_set_ring(sk, &req_u, 1, 1); 3065 } 3066 release_sock(sk); 3067 3068 f = fanout_release(sk); 3069 3070 synchronize_net(); 3071 3072 kfree(po->rollover); 3073 if (f) { 3074 fanout_release_data(f); 3075 kfree(f); 3076 } 3077 /* 3078 * Now the socket is dead. No more input will appear. 3079 */ 3080 sock_orphan(sk); 3081 sock->sk = NULL; 3082 3083 /* Purge queues */ 3084 3085 skb_queue_purge(&sk->sk_receive_queue); 3086 packet_free_pending(po); 3087 sk_refcnt_debug_release(sk); 3088 3089 sock_put(sk); 3090 return 0; 3091 } 3092 3093 /* 3094 * Attach a packet hook. 3095 */ 3096 3097 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3098 __be16 proto) 3099 { 3100 struct packet_sock *po = pkt_sk(sk); 3101 struct net_device *dev_curr; 3102 __be16 proto_curr; 3103 bool need_rehook; 3104 struct net_device *dev = NULL; 3105 int ret = 0; 3106 bool unlisted = false; 3107 3108 lock_sock(sk); 3109 spin_lock(&po->bind_lock); 3110 rcu_read_lock(); 3111 3112 if (po->fanout) { 3113 ret = -EINVAL; 3114 goto out_unlock; 3115 } 3116 3117 if (name) { 3118 dev = dev_get_by_name_rcu(sock_net(sk), name); 3119 if (!dev) { 3120 ret = -ENODEV; 3121 goto out_unlock; 3122 } 3123 } else if (ifindex) { 3124 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3125 if (!dev) { 3126 ret = -ENODEV; 3127 goto out_unlock; 3128 } 3129 } 3130 3131 if (dev) 3132 dev_hold(dev); 3133 3134 proto_curr = po->prot_hook.type; 3135 dev_curr = po->prot_hook.dev; 3136 3137 need_rehook = proto_curr != proto || dev_curr != dev; 3138 3139 if (need_rehook) { 3140 if (po->running) { 3141 rcu_read_unlock(); 3142 /* prevents packet_notifier() from calling 3143 * register_prot_hook() 3144 */ 3145 po->num = 0; 3146 __unregister_prot_hook(sk, true); 3147 rcu_read_lock(); 3148 dev_curr = po->prot_hook.dev; 3149 if (dev) 3150 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3151 dev->ifindex); 3152 } 3153 3154 BUG_ON(po->running); 3155 po->num = proto; 3156 po->prot_hook.type = proto; 3157 3158 if (unlikely(unlisted)) { 3159 dev_put(dev); 3160 po->prot_hook.dev = NULL; 3161 po->ifindex = -1; 3162 packet_cached_dev_reset(po); 3163 } else { 3164 po->prot_hook.dev = dev; 3165 po->ifindex = dev ? dev->ifindex : 0; 3166 packet_cached_dev_assign(po, dev); 3167 } 3168 } 3169 if (dev_curr) 3170 dev_put(dev_curr); 3171 3172 if (proto == 0 || !need_rehook) 3173 goto out_unlock; 3174 3175 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3176 register_prot_hook(sk); 3177 } else { 3178 sk->sk_err = ENETDOWN; 3179 if (!sock_flag(sk, SOCK_DEAD)) 3180 sk->sk_error_report(sk); 3181 } 3182 3183 out_unlock: 3184 rcu_read_unlock(); 3185 spin_unlock(&po->bind_lock); 3186 release_sock(sk); 3187 return ret; 3188 } 3189 3190 /* 3191 * Bind a packet socket to a device 3192 */ 3193 3194 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3195 int addr_len) 3196 { 3197 struct sock *sk = sock->sk; 3198 char name[sizeof(uaddr->sa_data) + 1]; 3199 3200 /* 3201 * Check legality 3202 */ 3203 3204 if (addr_len != sizeof(struct sockaddr)) 3205 return -EINVAL; 3206 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3207 * zero-terminated. 3208 */ 3209 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data)); 3210 name[sizeof(uaddr->sa_data)] = 0; 3211 3212 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); 3213 } 3214 3215 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3216 { 3217 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3218 struct sock *sk = sock->sk; 3219 3220 /* 3221 * Check legality 3222 */ 3223 3224 if (addr_len < sizeof(struct sockaddr_ll)) 3225 return -EINVAL; 3226 if (sll->sll_family != AF_PACKET) 3227 return -EINVAL; 3228 3229 return packet_do_bind(sk, NULL, sll->sll_ifindex, 3230 sll->sll_protocol ? : pkt_sk(sk)->num); 3231 } 3232 3233 static struct proto packet_proto = { 3234 .name = "PACKET", 3235 .owner = THIS_MODULE, 3236 .obj_size = sizeof(struct packet_sock), 3237 }; 3238 3239 /* 3240 * Create a packet of type SOCK_PACKET. 3241 */ 3242 3243 static int packet_create(struct net *net, struct socket *sock, int protocol, 3244 int kern) 3245 { 3246 struct sock *sk; 3247 struct packet_sock *po; 3248 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3249 int err; 3250 3251 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3252 return -EPERM; 3253 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3254 sock->type != SOCK_PACKET) 3255 return -ESOCKTNOSUPPORT; 3256 3257 sock->state = SS_UNCONNECTED; 3258 3259 err = -ENOBUFS; 3260 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3261 if (sk == NULL) 3262 goto out; 3263 3264 sock->ops = &packet_ops; 3265 if (sock->type == SOCK_PACKET) 3266 sock->ops = &packet_ops_spkt; 3267 3268 sock_init_data(sock, sk); 3269 3270 po = pkt_sk(sk); 3271 init_completion(&po->skb_completion); 3272 sk->sk_family = PF_PACKET; 3273 po->num = proto; 3274 po->xmit = dev_queue_xmit; 3275 3276 err = packet_alloc_pending(po); 3277 if (err) 3278 goto out2; 3279 3280 packet_cached_dev_reset(po); 3281 3282 sk->sk_destruct = packet_sock_destruct; 3283 sk_refcnt_debug_inc(sk); 3284 3285 /* 3286 * Attach a protocol block 3287 */ 3288 3289 spin_lock_init(&po->bind_lock); 3290 mutex_init(&po->pg_vec_lock); 3291 po->rollover = NULL; 3292 po->prot_hook.func = packet_rcv; 3293 3294 if (sock->type == SOCK_PACKET) 3295 po->prot_hook.func = packet_rcv_spkt; 3296 3297 po->prot_hook.af_packet_priv = sk; 3298 3299 if (proto) { 3300 po->prot_hook.type = proto; 3301 __register_prot_hook(sk); 3302 } 3303 3304 mutex_lock(&net->packet.sklist_lock); 3305 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3306 mutex_unlock(&net->packet.sklist_lock); 3307 3308 preempt_disable(); 3309 sock_prot_inuse_add(net, &packet_proto, 1); 3310 preempt_enable(); 3311 3312 return 0; 3313 out2: 3314 sk_free(sk); 3315 out: 3316 return err; 3317 } 3318 3319 /* 3320 * Pull a packet from our receive queue and hand it to the user. 3321 * If necessary we block. 3322 */ 3323 3324 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3325 int flags) 3326 { 3327 struct sock *sk = sock->sk; 3328 struct sk_buff *skb; 3329 int copied, err; 3330 int vnet_hdr_len = 0; 3331 unsigned int origlen = 0; 3332 3333 err = -EINVAL; 3334 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3335 goto out; 3336 3337 #if 0 3338 /* What error should we return now? EUNATTACH? */ 3339 if (pkt_sk(sk)->ifindex < 0) 3340 return -ENODEV; 3341 #endif 3342 3343 if (flags & MSG_ERRQUEUE) { 3344 err = sock_recv_errqueue(sk, msg, len, 3345 SOL_PACKET, PACKET_TX_TIMESTAMP); 3346 goto out; 3347 } 3348 3349 /* 3350 * Call the generic datagram receiver. This handles all sorts 3351 * of horrible races and re-entrancy so we can forget about it 3352 * in the protocol layers. 3353 * 3354 * Now it will return ENETDOWN, if device have just gone down, 3355 * but then it will block. 3356 */ 3357 3358 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3359 3360 /* 3361 * An error occurred so return it. Because skb_recv_datagram() 3362 * handles the blocking we don't see and worry about blocking 3363 * retries. 3364 */ 3365 3366 if (skb == NULL) 3367 goto out; 3368 3369 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3370 3371 if (pkt_sk(sk)->has_vnet_hdr) { 3372 err = packet_rcv_vnet(msg, skb, &len); 3373 if (err) 3374 goto out_free; 3375 vnet_hdr_len = sizeof(struct virtio_net_hdr); 3376 } 3377 3378 /* You lose any data beyond the buffer you gave. If it worries 3379 * a user program they can ask the device for its MTU 3380 * anyway. 3381 */ 3382 copied = skb->len; 3383 if (copied > len) { 3384 copied = len; 3385 msg->msg_flags |= MSG_TRUNC; 3386 } 3387 3388 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3389 if (err) 3390 goto out_free; 3391 3392 if (sock->type != SOCK_PACKET) { 3393 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3394 3395 /* Original length was stored in sockaddr_ll fields */ 3396 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3397 sll->sll_family = AF_PACKET; 3398 sll->sll_protocol = skb->protocol; 3399 } 3400 3401 sock_recv_ts_and_drops(msg, sk, skb); 3402 3403 if (msg->msg_name) { 3404 int copy_len; 3405 3406 /* If the address length field is there to be filled 3407 * in, we fill it in now. 3408 */ 3409 if (sock->type == SOCK_PACKET) { 3410 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3411 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3412 copy_len = msg->msg_namelen; 3413 } else { 3414 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3415 3416 msg->msg_namelen = sll->sll_halen + 3417 offsetof(struct sockaddr_ll, sll_addr); 3418 copy_len = msg->msg_namelen; 3419 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3420 memset(msg->msg_name + 3421 offsetof(struct sockaddr_ll, sll_addr), 3422 0, sizeof(sll->sll_addr)); 3423 msg->msg_namelen = sizeof(struct sockaddr_ll); 3424 } 3425 } 3426 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3427 } 3428 3429 if (pkt_sk(sk)->auxdata) { 3430 struct tpacket_auxdata aux; 3431 3432 aux.tp_status = TP_STATUS_USER; 3433 if (skb->ip_summed == CHECKSUM_PARTIAL) 3434 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3435 else if (skb->pkt_type != PACKET_OUTGOING && 3436 (skb->ip_summed == CHECKSUM_COMPLETE || 3437 skb_csum_unnecessary(skb))) 3438 aux.tp_status |= TP_STATUS_CSUM_VALID; 3439 3440 aux.tp_len = origlen; 3441 aux.tp_snaplen = skb->len; 3442 aux.tp_mac = 0; 3443 aux.tp_net = skb_network_offset(skb); 3444 if (skb_vlan_tag_present(skb)) { 3445 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3446 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3447 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3448 } else { 3449 aux.tp_vlan_tci = 0; 3450 aux.tp_vlan_tpid = 0; 3451 } 3452 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3453 } 3454 3455 /* 3456 * Free or return the buffer as appropriate. Again this 3457 * hides all the races and re-entrancy issues from us. 3458 */ 3459 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3460 3461 out_free: 3462 skb_free_datagram(sk, skb); 3463 out: 3464 return err; 3465 } 3466 3467 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3468 int peer) 3469 { 3470 struct net_device *dev; 3471 struct sock *sk = sock->sk; 3472 3473 if (peer) 3474 return -EOPNOTSUPP; 3475 3476 uaddr->sa_family = AF_PACKET; 3477 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3478 rcu_read_lock(); 3479 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3480 if (dev) 3481 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3482 rcu_read_unlock(); 3483 3484 return sizeof(*uaddr); 3485 } 3486 3487 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3488 int peer) 3489 { 3490 struct net_device *dev; 3491 struct sock *sk = sock->sk; 3492 struct packet_sock *po = pkt_sk(sk); 3493 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3494 3495 if (peer) 3496 return -EOPNOTSUPP; 3497 3498 sll->sll_family = AF_PACKET; 3499 sll->sll_ifindex = po->ifindex; 3500 sll->sll_protocol = po->num; 3501 sll->sll_pkttype = 0; 3502 rcu_read_lock(); 3503 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3504 if (dev) { 3505 sll->sll_hatype = dev->type; 3506 sll->sll_halen = dev->addr_len; 3507 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3508 } else { 3509 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3510 sll->sll_halen = 0; 3511 } 3512 rcu_read_unlock(); 3513 3514 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3515 } 3516 3517 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3518 int what) 3519 { 3520 switch (i->type) { 3521 case PACKET_MR_MULTICAST: 3522 if (i->alen != dev->addr_len) 3523 return -EINVAL; 3524 if (what > 0) 3525 return dev_mc_add(dev, i->addr); 3526 else 3527 return dev_mc_del(dev, i->addr); 3528 break; 3529 case PACKET_MR_PROMISC: 3530 return dev_set_promiscuity(dev, what); 3531 case PACKET_MR_ALLMULTI: 3532 return dev_set_allmulti(dev, what); 3533 case PACKET_MR_UNICAST: 3534 if (i->alen != dev->addr_len) 3535 return -EINVAL; 3536 if (what > 0) 3537 return dev_uc_add(dev, i->addr); 3538 else 3539 return dev_uc_del(dev, i->addr); 3540 break; 3541 default: 3542 break; 3543 } 3544 return 0; 3545 } 3546 3547 static void packet_dev_mclist_delete(struct net_device *dev, 3548 struct packet_mclist **mlp) 3549 { 3550 struct packet_mclist *ml; 3551 3552 while ((ml = *mlp) != NULL) { 3553 if (ml->ifindex == dev->ifindex) { 3554 packet_dev_mc(dev, ml, -1); 3555 *mlp = ml->next; 3556 kfree(ml); 3557 } else 3558 mlp = &ml->next; 3559 } 3560 } 3561 3562 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3563 { 3564 struct packet_sock *po = pkt_sk(sk); 3565 struct packet_mclist *ml, *i; 3566 struct net_device *dev; 3567 int err; 3568 3569 rtnl_lock(); 3570 3571 err = -ENODEV; 3572 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3573 if (!dev) 3574 goto done; 3575 3576 err = -EINVAL; 3577 if (mreq->mr_alen > dev->addr_len) 3578 goto done; 3579 3580 err = -ENOBUFS; 3581 i = kmalloc(sizeof(*i), GFP_KERNEL); 3582 if (i == NULL) 3583 goto done; 3584 3585 err = 0; 3586 for (ml = po->mclist; ml; ml = ml->next) { 3587 if (ml->ifindex == mreq->mr_ifindex && 3588 ml->type == mreq->mr_type && 3589 ml->alen == mreq->mr_alen && 3590 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3591 ml->count++; 3592 /* Free the new element ... */ 3593 kfree(i); 3594 goto done; 3595 } 3596 } 3597 3598 i->type = mreq->mr_type; 3599 i->ifindex = mreq->mr_ifindex; 3600 i->alen = mreq->mr_alen; 3601 memcpy(i->addr, mreq->mr_address, i->alen); 3602 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3603 i->count = 1; 3604 i->next = po->mclist; 3605 po->mclist = i; 3606 err = packet_dev_mc(dev, i, 1); 3607 if (err) { 3608 po->mclist = i->next; 3609 kfree(i); 3610 } 3611 3612 done: 3613 rtnl_unlock(); 3614 return err; 3615 } 3616 3617 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3618 { 3619 struct packet_mclist *ml, **mlp; 3620 3621 rtnl_lock(); 3622 3623 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3624 if (ml->ifindex == mreq->mr_ifindex && 3625 ml->type == mreq->mr_type && 3626 ml->alen == mreq->mr_alen && 3627 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3628 if (--ml->count == 0) { 3629 struct net_device *dev; 3630 *mlp = ml->next; 3631 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3632 if (dev) 3633 packet_dev_mc(dev, ml, -1); 3634 kfree(ml); 3635 } 3636 break; 3637 } 3638 } 3639 rtnl_unlock(); 3640 return 0; 3641 } 3642 3643 static void packet_flush_mclist(struct sock *sk) 3644 { 3645 struct packet_sock *po = pkt_sk(sk); 3646 struct packet_mclist *ml; 3647 3648 if (!po->mclist) 3649 return; 3650 3651 rtnl_lock(); 3652 while ((ml = po->mclist) != NULL) { 3653 struct net_device *dev; 3654 3655 po->mclist = ml->next; 3656 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3657 if (dev != NULL) 3658 packet_dev_mc(dev, ml, -1); 3659 kfree(ml); 3660 } 3661 rtnl_unlock(); 3662 } 3663 3664 static int 3665 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3666 unsigned int optlen) 3667 { 3668 struct sock *sk = sock->sk; 3669 struct packet_sock *po = pkt_sk(sk); 3670 int ret; 3671 3672 if (level != SOL_PACKET) 3673 return -ENOPROTOOPT; 3674 3675 switch (optname) { 3676 case PACKET_ADD_MEMBERSHIP: 3677 case PACKET_DROP_MEMBERSHIP: 3678 { 3679 struct packet_mreq_max mreq; 3680 int len = optlen; 3681 memset(&mreq, 0, sizeof(mreq)); 3682 if (len < sizeof(struct packet_mreq)) 3683 return -EINVAL; 3684 if (len > sizeof(mreq)) 3685 len = sizeof(mreq); 3686 if (copy_from_sockptr(&mreq, optval, len)) 3687 return -EFAULT; 3688 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3689 return -EINVAL; 3690 if (optname == PACKET_ADD_MEMBERSHIP) 3691 ret = packet_mc_add(sk, &mreq); 3692 else 3693 ret = packet_mc_drop(sk, &mreq); 3694 return ret; 3695 } 3696 3697 case PACKET_RX_RING: 3698 case PACKET_TX_RING: 3699 { 3700 union tpacket_req_u req_u; 3701 int len; 3702 3703 lock_sock(sk); 3704 switch (po->tp_version) { 3705 case TPACKET_V1: 3706 case TPACKET_V2: 3707 len = sizeof(req_u.req); 3708 break; 3709 case TPACKET_V3: 3710 default: 3711 len = sizeof(req_u.req3); 3712 break; 3713 } 3714 if (optlen < len) { 3715 ret = -EINVAL; 3716 } else { 3717 if (copy_from_sockptr(&req_u.req, optval, len)) 3718 ret = -EFAULT; 3719 else 3720 ret = packet_set_ring(sk, &req_u, 0, 3721 optname == PACKET_TX_RING); 3722 } 3723 release_sock(sk); 3724 return ret; 3725 } 3726 case PACKET_COPY_THRESH: 3727 { 3728 int val; 3729 3730 if (optlen != sizeof(val)) 3731 return -EINVAL; 3732 if (copy_from_sockptr(&val, optval, sizeof(val))) 3733 return -EFAULT; 3734 3735 pkt_sk(sk)->copy_thresh = val; 3736 return 0; 3737 } 3738 case PACKET_VERSION: 3739 { 3740 int val; 3741 3742 if (optlen != sizeof(val)) 3743 return -EINVAL; 3744 if (copy_from_sockptr(&val, optval, sizeof(val))) 3745 return -EFAULT; 3746 switch (val) { 3747 case TPACKET_V1: 3748 case TPACKET_V2: 3749 case TPACKET_V3: 3750 break; 3751 default: 3752 return -EINVAL; 3753 } 3754 lock_sock(sk); 3755 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3756 ret = -EBUSY; 3757 } else { 3758 po->tp_version = val; 3759 ret = 0; 3760 } 3761 release_sock(sk); 3762 return ret; 3763 } 3764 case PACKET_RESERVE: 3765 { 3766 unsigned int val; 3767 3768 if (optlen != sizeof(val)) 3769 return -EINVAL; 3770 if (copy_from_sockptr(&val, optval, sizeof(val))) 3771 return -EFAULT; 3772 if (val > INT_MAX) 3773 return -EINVAL; 3774 lock_sock(sk); 3775 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3776 ret = -EBUSY; 3777 } else { 3778 po->tp_reserve = val; 3779 ret = 0; 3780 } 3781 release_sock(sk); 3782 return ret; 3783 } 3784 case PACKET_LOSS: 3785 { 3786 unsigned int val; 3787 3788 if (optlen != sizeof(val)) 3789 return -EINVAL; 3790 if (copy_from_sockptr(&val, optval, sizeof(val))) 3791 return -EFAULT; 3792 3793 lock_sock(sk); 3794 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3795 ret = -EBUSY; 3796 } else { 3797 po->tp_loss = !!val; 3798 ret = 0; 3799 } 3800 release_sock(sk); 3801 return ret; 3802 } 3803 case PACKET_AUXDATA: 3804 { 3805 int val; 3806 3807 if (optlen < sizeof(val)) 3808 return -EINVAL; 3809 if (copy_from_sockptr(&val, optval, sizeof(val))) 3810 return -EFAULT; 3811 3812 lock_sock(sk); 3813 po->auxdata = !!val; 3814 release_sock(sk); 3815 return 0; 3816 } 3817 case PACKET_ORIGDEV: 3818 { 3819 int val; 3820 3821 if (optlen < sizeof(val)) 3822 return -EINVAL; 3823 if (copy_from_sockptr(&val, optval, sizeof(val))) 3824 return -EFAULT; 3825 3826 lock_sock(sk); 3827 po->origdev = !!val; 3828 release_sock(sk); 3829 return 0; 3830 } 3831 case PACKET_VNET_HDR: 3832 { 3833 int val; 3834 3835 if (sock->type != SOCK_RAW) 3836 return -EINVAL; 3837 if (optlen < sizeof(val)) 3838 return -EINVAL; 3839 if (copy_from_sockptr(&val, optval, sizeof(val))) 3840 return -EFAULT; 3841 3842 lock_sock(sk); 3843 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3844 ret = -EBUSY; 3845 } else { 3846 po->has_vnet_hdr = !!val; 3847 ret = 0; 3848 } 3849 release_sock(sk); 3850 return ret; 3851 } 3852 case PACKET_TIMESTAMP: 3853 { 3854 int val; 3855 3856 if (optlen != sizeof(val)) 3857 return -EINVAL; 3858 if (copy_from_sockptr(&val, optval, sizeof(val))) 3859 return -EFAULT; 3860 3861 po->tp_tstamp = val; 3862 return 0; 3863 } 3864 case PACKET_FANOUT: 3865 { 3866 int val; 3867 3868 if (optlen != sizeof(val)) 3869 return -EINVAL; 3870 if (copy_from_sockptr(&val, optval, sizeof(val))) 3871 return -EFAULT; 3872 3873 return fanout_add(sk, val & 0xffff, val >> 16); 3874 } 3875 case PACKET_FANOUT_DATA: 3876 { 3877 if (!po->fanout) 3878 return -EINVAL; 3879 3880 return fanout_set_data(po, optval, optlen); 3881 } 3882 case PACKET_IGNORE_OUTGOING: 3883 { 3884 int val; 3885 3886 if (optlen != sizeof(val)) 3887 return -EINVAL; 3888 if (copy_from_sockptr(&val, optval, sizeof(val))) 3889 return -EFAULT; 3890 if (val < 0 || val > 1) 3891 return -EINVAL; 3892 3893 po->prot_hook.ignore_outgoing = !!val; 3894 return 0; 3895 } 3896 case PACKET_TX_HAS_OFF: 3897 { 3898 unsigned int val; 3899 3900 if (optlen != sizeof(val)) 3901 return -EINVAL; 3902 if (copy_from_sockptr(&val, optval, sizeof(val))) 3903 return -EFAULT; 3904 3905 lock_sock(sk); 3906 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3907 ret = -EBUSY; 3908 } else { 3909 po->tp_tx_has_off = !!val; 3910 ret = 0; 3911 } 3912 release_sock(sk); 3913 return 0; 3914 } 3915 case PACKET_QDISC_BYPASS: 3916 { 3917 int val; 3918 3919 if (optlen != sizeof(val)) 3920 return -EINVAL; 3921 if (copy_from_sockptr(&val, optval, sizeof(val))) 3922 return -EFAULT; 3923 3924 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3925 return 0; 3926 } 3927 default: 3928 return -ENOPROTOOPT; 3929 } 3930 } 3931 3932 static int packet_getsockopt(struct socket *sock, int level, int optname, 3933 char __user *optval, int __user *optlen) 3934 { 3935 int len; 3936 int val, lv = sizeof(val); 3937 struct sock *sk = sock->sk; 3938 struct packet_sock *po = pkt_sk(sk); 3939 void *data = &val; 3940 union tpacket_stats_u st; 3941 struct tpacket_rollover_stats rstats; 3942 int drops; 3943 3944 if (level != SOL_PACKET) 3945 return -ENOPROTOOPT; 3946 3947 if (get_user(len, optlen)) 3948 return -EFAULT; 3949 3950 if (len < 0) 3951 return -EINVAL; 3952 3953 switch (optname) { 3954 case PACKET_STATISTICS: 3955 spin_lock_bh(&sk->sk_receive_queue.lock); 3956 memcpy(&st, &po->stats, sizeof(st)); 3957 memset(&po->stats, 0, sizeof(po->stats)); 3958 spin_unlock_bh(&sk->sk_receive_queue.lock); 3959 drops = atomic_xchg(&po->tp_drops, 0); 3960 3961 if (po->tp_version == TPACKET_V3) { 3962 lv = sizeof(struct tpacket_stats_v3); 3963 st.stats3.tp_drops = drops; 3964 st.stats3.tp_packets += drops; 3965 data = &st.stats3; 3966 } else { 3967 lv = sizeof(struct tpacket_stats); 3968 st.stats1.tp_drops = drops; 3969 st.stats1.tp_packets += drops; 3970 data = &st.stats1; 3971 } 3972 3973 break; 3974 case PACKET_AUXDATA: 3975 val = po->auxdata; 3976 break; 3977 case PACKET_ORIGDEV: 3978 val = po->origdev; 3979 break; 3980 case PACKET_VNET_HDR: 3981 val = po->has_vnet_hdr; 3982 break; 3983 case PACKET_VERSION: 3984 val = po->tp_version; 3985 break; 3986 case PACKET_HDRLEN: 3987 if (len > sizeof(int)) 3988 len = sizeof(int); 3989 if (len < sizeof(int)) 3990 return -EINVAL; 3991 if (copy_from_user(&val, optval, len)) 3992 return -EFAULT; 3993 switch (val) { 3994 case TPACKET_V1: 3995 val = sizeof(struct tpacket_hdr); 3996 break; 3997 case TPACKET_V2: 3998 val = sizeof(struct tpacket2_hdr); 3999 break; 4000 case TPACKET_V3: 4001 val = sizeof(struct tpacket3_hdr); 4002 break; 4003 default: 4004 return -EINVAL; 4005 } 4006 break; 4007 case PACKET_RESERVE: 4008 val = po->tp_reserve; 4009 break; 4010 case PACKET_LOSS: 4011 val = po->tp_loss; 4012 break; 4013 case PACKET_TIMESTAMP: 4014 val = po->tp_tstamp; 4015 break; 4016 case PACKET_FANOUT: 4017 val = (po->fanout ? 4018 ((u32)po->fanout->id | 4019 ((u32)po->fanout->type << 16) | 4020 ((u32)po->fanout->flags << 24)) : 4021 0); 4022 break; 4023 case PACKET_IGNORE_OUTGOING: 4024 val = po->prot_hook.ignore_outgoing; 4025 break; 4026 case PACKET_ROLLOVER_STATS: 4027 if (!po->rollover) 4028 return -EINVAL; 4029 rstats.tp_all = atomic_long_read(&po->rollover->num); 4030 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4031 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4032 data = &rstats; 4033 lv = sizeof(rstats); 4034 break; 4035 case PACKET_TX_HAS_OFF: 4036 val = po->tp_tx_has_off; 4037 break; 4038 case PACKET_QDISC_BYPASS: 4039 val = packet_use_direct_xmit(po); 4040 break; 4041 default: 4042 return -ENOPROTOOPT; 4043 } 4044 4045 if (len > lv) 4046 len = lv; 4047 if (put_user(len, optlen)) 4048 return -EFAULT; 4049 if (copy_to_user(optval, data, len)) 4050 return -EFAULT; 4051 return 0; 4052 } 4053 4054 static int packet_notifier(struct notifier_block *this, 4055 unsigned long msg, void *ptr) 4056 { 4057 struct sock *sk; 4058 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4059 struct net *net = dev_net(dev); 4060 4061 rcu_read_lock(); 4062 sk_for_each_rcu(sk, &net->packet.sklist) { 4063 struct packet_sock *po = pkt_sk(sk); 4064 4065 switch (msg) { 4066 case NETDEV_UNREGISTER: 4067 if (po->mclist) 4068 packet_dev_mclist_delete(dev, &po->mclist); 4069 fallthrough; 4070 4071 case NETDEV_DOWN: 4072 if (dev->ifindex == po->ifindex) { 4073 spin_lock(&po->bind_lock); 4074 if (po->running) { 4075 __unregister_prot_hook(sk, false); 4076 sk->sk_err = ENETDOWN; 4077 if (!sock_flag(sk, SOCK_DEAD)) 4078 sk->sk_error_report(sk); 4079 } 4080 if (msg == NETDEV_UNREGISTER) { 4081 packet_cached_dev_reset(po); 4082 po->ifindex = -1; 4083 if (po->prot_hook.dev) 4084 dev_put(po->prot_hook.dev); 4085 po->prot_hook.dev = NULL; 4086 } 4087 spin_unlock(&po->bind_lock); 4088 } 4089 break; 4090 case NETDEV_UP: 4091 if (dev->ifindex == po->ifindex) { 4092 spin_lock(&po->bind_lock); 4093 if (po->num) 4094 register_prot_hook(sk); 4095 spin_unlock(&po->bind_lock); 4096 } 4097 break; 4098 } 4099 } 4100 rcu_read_unlock(); 4101 return NOTIFY_DONE; 4102 } 4103 4104 4105 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4106 unsigned long arg) 4107 { 4108 struct sock *sk = sock->sk; 4109 4110 switch (cmd) { 4111 case SIOCOUTQ: 4112 { 4113 int amount = sk_wmem_alloc_get(sk); 4114 4115 return put_user(amount, (int __user *)arg); 4116 } 4117 case SIOCINQ: 4118 { 4119 struct sk_buff *skb; 4120 int amount = 0; 4121 4122 spin_lock_bh(&sk->sk_receive_queue.lock); 4123 skb = skb_peek(&sk->sk_receive_queue); 4124 if (skb) 4125 amount = skb->len; 4126 spin_unlock_bh(&sk->sk_receive_queue.lock); 4127 return put_user(amount, (int __user *)arg); 4128 } 4129 #ifdef CONFIG_INET 4130 case SIOCADDRT: 4131 case SIOCDELRT: 4132 case SIOCDARP: 4133 case SIOCGARP: 4134 case SIOCSARP: 4135 case SIOCGIFADDR: 4136 case SIOCSIFADDR: 4137 case SIOCGIFBRDADDR: 4138 case SIOCSIFBRDADDR: 4139 case SIOCGIFNETMASK: 4140 case SIOCSIFNETMASK: 4141 case SIOCGIFDSTADDR: 4142 case SIOCSIFDSTADDR: 4143 case SIOCSIFFLAGS: 4144 return inet_dgram_ops.ioctl(sock, cmd, arg); 4145 #endif 4146 4147 default: 4148 return -ENOIOCTLCMD; 4149 } 4150 return 0; 4151 } 4152 4153 static __poll_t packet_poll(struct file *file, struct socket *sock, 4154 poll_table *wait) 4155 { 4156 struct sock *sk = sock->sk; 4157 struct packet_sock *po = pkt_sk(sk); 4158 __poll_t mask = datagram_poll(file, sock, wait); 4159 4160 spin_lock_bh(&sk->sk_receive_queue.lock); 4161 if (po->rx_ring.pg_vec) { 4162 if (!packet_previous_rx_frame(po, &po->rx_ring, 4163 TP_STATUS_KERNEL)) 4164 mask |= EPOLLIN | EPOLLRDNORM; 4165 } 4166 packet_rcv_try_clear_pressure(po); 4167 spin_unlock_bh(&sk->sk_receive_queue.lock); 4168 spin_lock_bh(&sk->sk_write_queue.lock); 4169 if (po->tx_ring.pg_vec) { 4170 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4171 mask |= EPOLLOUT | EPOLLWRNORM; 4172 } 4173 spin_unlock_bh(&sk->sk_write_queue.lock); 4174 return mask; 4175 } 4176 4177 4178 /* Dirty? Well, I still did not learn better way to account 4179 * for user mmaps. 4180 */ 4181 4182 static void packet_mm_open(struct vm_area_struct *vma) 4183 { 4184 struct file *file = vma->vm_file; 4185 struct socket *sock = file->private_data; 4186 struct sock *sk = sock->sk; 4187 4188 if (sk) 4189 atomic_inc(&pkt_sk(sk)->mapped); 4190 } 4191 4192 static void packet_mm_close(struct vm_area_struct *vma) 4193 { 4194 struct file *file = vma->vm_file; 4195 struct socket *sock = file->private_data; 4196 struct sock *sk = sock->sk; 4197 4198 if (sk) 4199 atomic_dec(&pkt_sk(sk)->mapped); 4200 } 4201 4202 static const struct vm_operations_struct packet_mmap_ops = { 4203 .open = packet_mm_open, 4204 .close = packet_mm_close, 4205 }; 4206 4207 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4208 unsigned int len) 4209 { 4210 int i; 4211 4212 for (i = 0; i < len; i++) { 4213 if (likely(pg_vec[i].buffer)) { 4214 if (is_vmalloc_addr(pg_vec[i].buffer)) 4215 vfree(pg_vec[i].buffer); 4216 else 4217 free_pages((unsigned long)pg_vec[i].buffer, 4218 order); 4219 pg_vec[i].buffer = NULL; 4220 } 4221 } 4222 kfree(pg_vec); 4223 } 4224 4225 static char *alloc_one_pg_vec_page(unsigned long order) 4226 { 4227 char *buffer; 4228 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4229 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4230 4231 buffer = (char *) __get_free_pages(gfp_flags, order); 4232 if (buffer) 4233 return buffer; 4234 4235 /* __get_free_pages failed, fall back to vmalloc */ 4236 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4237 if (buffer) 4238 return buffer; 4239 4240 /* vmalloc failed, lets dig into swap here */ 4241 gfp_flags &= ~__GFP_NORETRY; 4242 buffer = (char *) __get_free_pages(gfp_flags, order); 4243 if (buffer) 4244 return buffer; 4245 4246 /* complete and utter failure */ 4247 return NULL; 4248 } 4249 4250 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4251 { 4252 unsigned int block_nr = req->tp_block_nr; 4253 struct pgv *pg_vec; 4254 int i; 4255 4256 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN); 4257 if (unlikely(!pg_vec)) 4258 goto out; 4259 4260 for (i = 0; i < block_nr; i++) { 4261 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4262 if (unlikely(!pg_vec[i].buffer)) 4263 goto out_free_pgvec; 4264 } 4265 4266 out: 4267 return pg_vec; 4268 4269 out_free_pgvec: 4270 free_pg_vec(pg_vec, order, block_nr); 4271 pg_vec = NULL; 4272 goto out; 4273 } 4274 4275 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4276 int closing, int tx_ring) 4277 { 4278 struct pgv *pg_vec = NULL; 4279 struct packet_sock *po = pkt_sk(sk); 4280 unsigned long *rx_owner_map = NULL; 4281 int was_running, order = 0; 4282 struct packet_ring_buffer *rb; 4283 struct sk_buff_head *rb_queue; 4284 __be16 num; 4285 int err; 4286 /* Added to avoid minimal code churn */ 4287 struct tpacket_req *req = &req_u->req; 4288 4289 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4290 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4291 4292 err = -EBUSY; 4293 if (!closing) { 4294 if (atomic_read(&po->mapped)) 4295 goto out; 4296 if (packet_read_pending(rb)) 4297 goto out; 4298 } 4299 4300 if (req->tp_block_nr) { 4301 unsigned int min_frame_size; 4302 4303 /* Sanity tests and some calculations */ 4304 err = -EBUSY; 4305 if (unlikely(rb->pg_vec)) 4306 goto out; 4307 4308 switch (po->tp_version) { 4309 case TPACKET_V1: 4310 po->tp_hdrlen = TPACKET_HDRLEN; 4311 break; 4312 case TPACKET_V2: 4313 po->tp_hdrlen = TPACKET2_HDRLEN; 4314 break; 4315 case TPACKET_V3: 4316 po->tp_hdrlen = TPACKET3_HDRLEN; 4317 break; 4318 } 4319 4320 err = -EINVAL; 4321 if (unlikely((int)req->tp_block_size <= 0)) 4322 goto out; 4323 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4324 goto out; 4325 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4326 if (po->tp_version >= TPACKET_V3 && 4327 req->tp_block_size < 4328 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4329 goto out; 4330 if (unlikely(req->tp_frame_size < min_frame_size)) 4331 goto out; 4332 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4333 goto out; 4334 4335 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4336 if (unlikely(rb->frames_per_block == 0)) 4337 goto out; 4338 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4339 goto out; 4340 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4341 req->tp_frame_nr)) 4342 goto out; 4343 4344 err = -ENOMEM; 4345 order = get_order(req->tp_block_size); 4346 pg_vec = alloc_pg_vec(req, order); 4347 if (unlikely(!pg_vec)) 4348 goto out; 4349 switch (po->tp_version) { 4350 case TPACKET_V3: 4351 /* Block transmit is not supported yet */ 4352 if (!tx_ring) { 4353 init_prb_bdqc(po, rb, pg_vec, req_u); 4354 } else { 4355 struct tpacket_req3 *req3 = &req_u->req3; 4356 4357 if (req3->tp_retire_blk_tov || 4358 req3->tp_sizeof_priv || 4359 req3->tp_feature_req_word) { 4360 err = -EINVAL; 4361 goto out_free_pg_vec; 4362 } 4363 } 4364 break; 4365 default: 4366 if (!tx_ring) { 4367 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4368 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4369 if (!rx_owner_map) 4370 goto out_free_pg_vec; 4371 } 4372 break; 4373 } 4374 } 4375 /* Done */ 4376 else { 4377 err = -EINVAL; 4378 if (unlikely(req->tp_frame_nr)) 4379 goto out; 4380 } 4381 4382 4383 /* Detach socket from network */ 4384 spin_lock(&po->bind_lock); 4385 was_running = po->running; 4386 num = po->num; 4387 if (was_running) { 4388 po->num = 0; 4389 __unregister_prot_hook(sk, false); 4390 } 4391 spin_unlock(&po->bind_lock); 4392 4393 synchronize_net(); 4394 4395 err = -EBUSY; 4396 mutex_lock(&po->pg_vec_lock); 4397 if (closing || atomic_read(&po->mapped) == 0) { 4398 err = 0; 4399 spin_lock_bh(&rb_queue->lock); 4400 swap(rb->pg_vec, pg_vec); 4401 if (po->tp_version <= TPACKET_V2) 4402 swap(rb->rx_owner_map, rx_owner_map); 4403 rb->frame_max = (req->tp_frame_nr - 1); 4404 rb->head = 0; 4405 rb->frame_size = req->tp_frame_size; 4406 spin_unlock_bh(&rb_queue->lock); 4407 4408 swap(rb->pg_vec_order, order); 4409 swap(rb->pg_vec_len, req->tp_block_nr); 4410 4411 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4412 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4413 tpacket_rcv : packet_rcv; 4414 skb_queue_purge(rb_queue); 4415 if (atomic_read(&po->mapped)) 4416 pr_err("packet_mmap: vma is busy: %d\n", 4417 atomic_read(&po->mapped)); 4418 } 4419 mutex_unlock(&po->pg_vec_lock); 4420 4421 spin_lock(&po->bind_lock); 4422 if (was_running) { 4423 po->num = num; 4424 register_prot_hook(sk); 4425 } 4426 spin_unlock(&po->bind_lock); 4427 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4428 /* Because we don't support block-based V3 on tx-ring */ 4429 if (!tx_ring) 4430 prb_shutdown_retire_blk_timer(po, rb_queue); 4431 } 4432 4433 out_free_pg_vec: 4434 bitmap_free(rx_owner_map); 4435 if (pg_vec) 4436 free_pg_vec(pg_vec, order, req->tp_block_nr); 4437 out: 4438 return err; 4439 } 4440 4441 static int packet_mmap(struct file *file, struct socket *sock, 4442 struct vm_area_struct *vma) 4443 { 4444 struct sock *sk = sock->sk; 4445 struct packet_sock *po = pkt_sk(sk); 4446 unsigned long size, expected_size; 4447 struct packet_ring_buffer *rb; 4448 unsigned long start; 4449 int err = -EINVAL; 4450 int i; 4451 4452 if (vma->vm_pgoff) 4453 return -EINVAL; 4454 4455 mutex_lock(&po->pg_vec_lock); 4456 4457 expected_size = 0; 4458 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4459 if (rb->pg_vec) { 4460 expected_size += rb->pg_vec_len 4461 * rb->pg_vec_pages 4462 * PAGE_SIZE; 4463 } 4464 } 4465 4466 if (expected_size == 0) 4467 goto out; 4468 4469 size = vma->vm_end - vma->vm_start; 4470 if (size != expected_size) 4471 goto out; 4472 4473 start = vma->vm_start; 4474 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4475 if (rb->pg_vec == NULL) 4476 continue; 4477 4478 for (i = 0; i < rb->pg_vec_len; i++) { 4479 struct page *page; 4480 void *kaddr = rb->pg_vec[i].buffer; 4481 int pg_num; 4482 4483 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4484 page = pgv_to_page(kaddr); 4485 err = vm_insert_page(vma, start, page); 4486 if (unlikely(err)) 4487 goto out; 4488 start += PAGE_SIZE; 4489 kaddr += PAGE_SIZE; 4490 } 4491 } 4492 } 4493 4494 atomic_inc(&po->mapped); 4495 vma->vm_ops = &packet_mmap_ops; 4496 err = 0; 4497 4498 out: 4499 mutex_unlock(&po->pg_vec_lock); 4500 return err; 4501 } 4502 4503 static const struct proto_ops packet_ops_spkt = { 4504 .family = PF_PACKET, 4505 .owner = THIS_MODULE, 4506 .release = packet_release, 4507 .bind = packet_bind_spkt, 4508 .connect = sock_no_connect, 4509 .socketpair = sock_no_socketpair, 4510 .accept = sock_no_accept, 4511 .getname = packet_getname_spkt, 4512 .poll = datagram_poll, 4513 .ioctl = packet_ioctl, 4514 .gettstamp = sock_gettstamp, 4515 .listen = sock_no_listen, 4516 .shutdown = sock_no_shutdown, 4517 .sendmsg = packet_sendmsg_spkt, 4518 .recvmsg = packet_recvmsg, 4519 .mmap = sock_no_mmap, 4520 .sendpage = sock_no_sendpage, 4521 }; 4522 4523 static const struct proto_ops packet_ops = { 4524 .family = PF_PACKET, 4525 .owner = THIS_MODULE, 4526 .release = packet_release, 4527 .bind = packet_bind, 4528 .connect = sock_no_connect, 4529 .socketpair = sock_no_socketpair, 4530 .accept = sock_no_accept, 4531 .getname = packet_getname, 4532 .poll = packet_poll, 4533 .ioctl = packet_ioctl, 4534 .gettstamp = sock_gettstamp, 4535 .listen = sock_no_listen, 4536 .shutdown = sock_no_shutdown, 4537 .setsockopt = packet_setsockopt, 4538 .getsockopt = packet_getsockopt, 4539 .sendmsg = packet_sendmsg, 4540 .recvmsg = packet_recvmsg, 4541 .mmap = packet_mmap, 4542 .sendpage = sock_no_sendpage, 4543 }; 4544 4545 static const struct net_proto_family packet_family_ops = { 4546 .family = PF_PACKET, 4547 .create = packet_create, 4548 .owner = THIS_MODULE, 4549 }; 4550 4551 static struct notifier_block packet_netdev_notifier = { 4552 .notifier_call = packet_notifier, 4553 }; 4554 4555 #ifdef CONFIG_PROC_FS 4556 4557 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4558 __acquires(RCU) 4559 { 4560 struct net *net = seq_file_net(seq); 4561 4562 rcu_read_lock(); 4563 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4564 } 4565 4566 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4567 { 4568 struct net *net = seq_file_net(seq); 4569 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4570 } 4571 4572 static void packet_seq_stop(struct seq_file *seq, void *v) 4573 __releases(RCU) 4574 { 4575 rcu_read_unlock(); 4576 } 4577 4578 static int packet_seq_show(struct seq_file *seq, void *v) 4579 { 4580 if (v == SEQ_START_TOKEN) 4581 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4582 else { 4583 struct sock *s = sk_entry(v); 4584 const struct packet_sock *po = pkt_sk(s); 4585 4586 seq_printf(seq, 4587 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4588 s, 4589 refcount_read(&s->sk_refcnt), 4590 s->sk_type, 4591 ntohs(po->num), 4592 po->ifindex, 4593 po->running, 4594 atomic_read(&s->sk_rmem_alloc), 4595 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4596 sock_i_ino(s)); 4597 } 4598 4599 return 0; 4600 } 4601 4602 static const struct seq_operations packet_seq_ops = { 4603 .start = packet_seq_start, 4604 .next = packet_seq_next, 4605 .stop = packet_seq_stop, 4606 .show = packet_seq_show, 4607 }; 4608 #endif 4609 4610 static int __net_init packet_net_init(struct net *net) 4611 { 4612 mutex_init(&net->packet.sklist_lock); 4613 INIT_HLIST_HEAD(&net->packet.sklist); 4614 4615 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4616 sizeof(struct seq_net_private))) 4617 return -ENOMEM; 4618 4619 return 0; 4620 } 4621 4622 static void __net_exit packet_net_exit(struct net *net) 4623 { 4624 remove_proc_entry("packet", net->proc_net); 4625 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4626 } 4627 4628 static struct pernet_operations packet_net_ops = { 4629 .init = packet_net_init, 4630 .exit = packet_net_exit, 4631 }; 4632 4633 4634 static void __exit packet_exit(void) 4635 { 4636 unregister_netdevice_notifier(&packet_netdev_notifier); 4637 unregister_pernet_subsys(&packet_net_ops); 4638 sock_unregister(PF_PACKET); 4639 proto_unregister(&packet_proto); 4640 } 4641 4642 static int __init packet_init(void) 4643 { 4644 int rc; 4645 4646 rc = proto_register(&packet_proto, 0); 4647 if (rc) 4648 goto out; 4649 rc = sock_register(&packet_family_ops); 4650 if (rc) 4651 goto out_proto; 4652 rc = register_pernet_subsys(&packet_net_ops); 4653 if (rc) 4654 goto out_sock; 4655 rc = register_netdevice_notifier(&packet_netdev_notifier); 4656 if (rc) 4657 goto out_pernet; 4658 4659 return 0; 4660 4661 out_pernet: 4662 unregister_pernet_subsys(&packet_net_ops); 4663 out_sock: 4664 sock_unregister(PF_PACKET); 4665 out_proto: 4666 proto_unregister(&packet_proto); 4667 out: 4668 return rc; 4669 } 4670 4671 module_init(packet_init); 4672 module_exit(packet_exit); 4673 MODULE_LICENSE("GPL"); 4674 MODULE_ALIAS_NETPROTO(PF_PACKET); 4675