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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 50 51 #include <linux/ethtool.h> 52 #include <linux/uio.h> 53 #include <linux/filter.h> 54 #include <linux/types.h> 55 #include <linux/mm.h> 56 #include <linux/capability.h> 57 #include <linux/fcntl.h> 58 #include <linux/socket.h> 59 #include <linux/in.h> 60 #include <linux/inet.h> 61 #include <linux/netdevice.h> 62 #include <linux/if_packet.h> 63 #include <linux/wireless.h> 64 #include <linux/kernel.h> 65 #include <linux/kmod.h> 66 #include <linux/slab.h> 67 #include <linux/vmalloc.h> 68 #include <net/net_namespace.h> 69 #include <net/ip.h> 70 #include <net/protocol.h> 71 #include <linux/skbuff.h> 72 #include <net/sock.h> 73 #include <linux/errno.h> 74 #include <linux/timer.h> 75 #include <linux/uaccess.h> 76 #include <asm/ioctls.h> 77 #include <asm/page.h> 78 #include <asm/cacheflush.h> 79 #include <asm/io.h> 80 #include <linux/proc_fs.h> 81 #include <linux/seq_file.h> 82 #include <linux/poll.h> 83 #include <linux/module.h> 84 #include <linux/init.h> 85 #include <linux/mutex.h> 86 #include <linux/if_vlan.h> 87 #include <linux/virtio_net.h> 88 #include <linux/errqueue.h> 89 #include <linux/net_tstamp.h> 90 #include <linux/percpu.h> 91 #ifdef CONFIG_INET 92 #include <net/inet_common.h> 93 #endif 94 #include <linux/bpf.h> 95 #include <net/compat.h> 96 #include <linux/netfilter_netdev.h> 97 98 #include "internal.h" 99 100 /* 101 Assumptions: 102 - If the device has no dev->header_ops->create, there is no LL header 103 visible above the device. In this case, its hard_header_len should be 0. 104 The device may prepend its own header internally. In this case, its 105 needed_headroom should be set to the space needed for it to add its 106 internal header. 107 For example, a WiFi driver pretending to be an Ethernet driver should 108 set its hard_header_len to be the Ethernet header length, and set its 109 needed_headroom to be (the real WiFi header length - the fake Ethernet 110 header length). 111 - packet socket receives packets with pulled ll header, 112 so that SOCK_RAW should push it back. 113 114 On receive: 115 ----------- 116 117 Incoming, dev_has_header(dev) == true 118 mac_header -> ll header 119 data -> data 120 121 Outgoing, dev_has_header(dev) == true 122 mac_header -> ll header 123 data -> ll header 124 125 Incoming, dev_has_header(dev) == false 126 mac_header -> data 127 However drivers often make it point to the ll header. 128 This is incorrect because the ll header should be invisible to us. 129 data -> data 130 131 Outgoing, dev_has_header(dev) == false 132 mac_header -> data. ll header is invisible to us. 133 data -> data 134 135 Resume 136 If dev_has_header(dev) == false we are unable to restore the ll header, 137 because it is invisible to us. 138 139 140 On transmit: 141 ------------ 142 143 dev_has_header(dev) == true 144 mac_header -> ll header 145 data -> ll header 146 147 dev_has_header(dev) == false (ll header is invisible to us) 148 mac_header -> data 149 data -> data 150 151 We should set network_header on output to the correct position, 152 packet classifier depends on it. 153 */ 154 155 /* Private packet socket structures. */ 156 157 /* identical to struct packet_mreq except it has 158 * a longer address field. 159 */ 160 struct packet_mreq_max { 161 int mr_ifindex; 162 unsigned short mr_type; 163 unsigned short mr_alen; 164 unsigned char mr_address[MAX_ADDR_LEN]; 165 }; 166 167 union tpacket_uhdr { 168 struct tpacket_hdr *h1; 169 struct tpacket2_hdr *h2; 170 struct tpacket3_hdr *h3; 171 void *raw; 172 }; 173 174 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 175 int closing, int tx_ring); 176 177 #define V3_ALIGNMENT (8) 178 179 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 180 181 #define BLK_PLUS_PRIV(sz_of_priv) \ 182 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 183 184 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 185 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 186 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 187 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 188 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 189 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 190 191 struct packet_sock; 192 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 193 struct packet_type *pt, struct net_device *orig_dev); 194 195 static void *packet_previous_frame(struct packet_sock *po, 196 struct packet_ring_buffer *rb, 197 int status); 198 static void packet_increment_head(struct packet_ring_buffer *buff); 199 static int prb_curr_blk_in_use(struct tpacket_block_desc *); 200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 201 struct packet_sock *); 202 static void prb_retire_current_block(struct tpacket_kbdq_core *, 203 struct packet_sock *, unsigned int status); 204 static int prb_queue_frozen(struct tpacket_kbdq_core *); 205 static void prb_open_block(struct tpacket_kbdq_core *, 206 struct tpacket_block_desc *); 207 static enum hrtimer_restart prb_retire_rx_blk_timer_expired(struct hrtimer *); 208 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 209 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 210 struct tpacket3_hdr *); 211 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 212 struct tpacket3_hdr *); 213 static void packet_flush_mclist(struct sock *sk); 214 static u16 packet_pick_tx_queue(struct sk_buff *skb); 215 216 struct packet_skb_cb { 217 union { 218 struct sockaddr_pkt pkt; 219 union { 220 /* Trick: alias skb original length with 221 * ll.sll_family and ll.protocol in order 222 * to save room. 223 */ 224 unsigned int origlen; 225 struct sockaddr_ll ll; 226 }; 227 } sa; 228 }; 229 230 #define vio_le() virtio_legacy_is_little_endian() 231 232 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 233 234 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 235 #define GET_PBLOCK_DESC(x, bid) \ 236 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 237 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 238 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 239 #define GET_NEXT_PRB_BLK_NUM(x) \ 240 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 241 ((x)->kactive_blk_num+1) : 0) 242 243 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 244 static void __fanout_link(struct sock *sk, struct packet_sock *po); 245 246 #ifdef CONFIG_NETFILTER_EGRESS 247 static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb) 248 { 249 struct sk_buff *next, *head = NULL, *tail; 250 int rc; 251 252 rcu_read_lock(); 253 for (; skb != NULL; skb = next) { 254 next = skb->next; 255 skb_mark_not_on_list(skb); 256 257 if (!nf_hook_egress(skb, &rc, skb->dev)) 258 continue; 259 260 if (!head) 261 head = skb; 262 else 263 tail->next = skb; 264 265 tail = skb; 266 } 267 rcu_read_unlock(); 268 269 return head; 270 } 271 #endif 272 273 static int packet_xmit(const struct packet_sock *po, struct sk_buff *skb) 274 { 275 if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS)) 276 return dev_queue_xmit(skb); 277 278 #ifdef CONFIG_NETFILTER_EGRESS 279 if (nf_hook_egress_active()) { 280 skb = nf_hook_direct_egress(skb); 281 if (!skb) 282 return NET_XMIT_DROP; 283 } 284 #endif 285 return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); 286 } 287 288 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 289 { 290 struct net_device *dev; 291 292 rcu_read_lock(); 293 dev = rcu_dereference(po->cached_dev); 294 dev_hold(dev); 295 rcu_read_unlock(); 296 297 return dev; 298 } 299 300 static void packet_cached_dev_assign(struct packet_sock *po, 301 struct net_device *dev) 302 { 303 rcu_assign_pointer(po->cached_dev, dev); 304 } 305 306 static void packet_cached_dev_reset(struct packet_sock *po) 307 { 308 RCU_INIT_POINTER(po->cached_dev, NULL); 309 } 310 311 static u16 packet_pick_tx_queue(struct sk_buff *skb) 312 { 313 struct net_device *dev = skb->dev; 314 const struct net_device_ops *ops = dev->netdev_ops; 315 int cpu = raw_smp_processor_id(); 316 u16 queue_index; 317 318 #ifdef CONFIG_XPS 319 skb->sender_cpu = cpu + 1; 320 #endif 321 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues); 322 if (ops->ndo_select_queue) { 323 queue_index = ops->ndo_select_queue(dev, skb, NULL); 324 queue_index = netdev_cap_txqueue(dev, queue_index); 325 } else { 326 queue_index = netdev_pick_tx(dev, skb, NULL); 327 } 328 329 return queue_index; 330 } 331 332 /* __register_prot_hook must be invoked through register_prot_hook 333 * or from a context in which asynchronous accesses to the packet 334 * socket is not possible (packet_create()). 335 */ 336 static void __register_prot_hook(struct sock *sk) 337 { 338 struct packet_sock *po = pkt_sk(sk); 339 340 if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 341 if (po->fanout) 342 __fanout_link(sk, po); 343 else 344 dev_add_pack(&po->prot_hook); 345 346 sock_hold(sk); 347 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1); 348 } 349 } 350 351 static void register_prot_hook(struct sock *sk) 352 { 353 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock); 354 __register_prot_hook(sk); 355 } 356 357 /* If the sync parameter is true, we will temporarily drop 358 * the po->bind_lock and do a synchronize_net to make sure no 359 * asynchronous packet processing paths still refer to the elements 360 * of po->prot_hook. If the sync parameter is false, it is the 361 * callers responsibility to take care of this. 362 */ 363 static void __unregister_prot_hook(struct sock *sk, bool sync) 364 { 365 struct packet_sock *po = pkt_sk(sk); 366 367 lockdep_assert_held_once(&po->bind_lock); 368 369 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0); 370 371 if (po->fanout) 372 __fanout_unlink(sk, po); 373 else 374 __dev_remove_pack(&po->prot_hook); 375 376 __sock_put(sk); 377 378 if (sync) { 379 spin_unlock(&po->bind_lock); 380 synchronize_net(); 381 spin_lock(&po->bind_lock); 382 } 383 } 384 385 static void unregister_prot_hook(struct sock *sk, bool sync) 386 { 387 struct packet_sock *po = pkt_sk(sk); 388 389 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) 390 __unregister_prot_hook(sk, sync); 391 } 392 393 static inline struct page * __pure pgv_to_page(void *addr) 394 { 395 if (is_vmalloc_addr(addr)) 396 return vmalloc_to_page(addr); 397 return virt_to_page(addr); 398 } 399 400 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 401 { 402 union tpacket_uhdr h; 403 404 /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */ 405 406 h.raw = frame; 407 switch (po->tp_version) { 408 case TPACKET_V1: 409 WRITE_ONCE(h.h1->tp_status, status); 410 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 411 break; 412 case TPACKET_V2: 413 WRITE_ONCE(h.h2->tp_status, status); 414 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 415 break; 416 case TPACKET_V3: 417 WRITE_ONCE(h.h3->tp_status, status); 418 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 419 break; 420 default: 421 WARN(1, "TPACKET version not supported.\n"); 422 BUG(); 423 } 424 425 smp_wmb(); 426 } 427 428 static int __packet_get_status(const struct packet_sock *po, void *frame) 429 { 430 union tpacket_uhdr h; 431 432 smp_rmb(); 433 434 /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */ 435 436 h.raw = frame; 437 switch (po->tp_version) { 438 case TPACKET_V1: 439 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 440 return READ_ONCE(h.h1->tp_status); 441 case TPACKET_V2: 442 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 443 return READ_ONCE(h.h2->tp_status); 444 case TPACKET_V3: 445 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 446 return READ_ONCE(h.h3->tp_status); 447 default: 448 WARN(1, "TPACKET version not supported.\n"); 449 BUG(); 450 return 0; 451 } 452 } 453 454 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, 455 unsigned int flags) 456 { 457 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 458 459 if (shhwtstamps && 460 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 461 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts)) 462 return TP_STATUS_TS_RAW_HARDWARE; 463 464 if ((flags & SOF_TIMESTAMPING_SOFTWARE) && 465 ktime_to_timespec64_cond(skb_tstamp(skb), ts)) 466 return TP_STATUS_TS_SOFTWARE; 467 468 return 0; 469 } 470 471 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 472 struct sk_buff *skb) 473 { 474 union tpacket_uhdr h; 475 struct timespec64 ts; 476 __u32 ts_status; 477 478 if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp)))) 479 return 0; 480 481 h.raw = frame; 482 /* 483 * versions 1 through 3 overflow the timestamps in y2106, since they 484 * all store the seconds in a 32-bit unsigned integer. 485 * If we create a version 4, that should have a 64-bit timestamp, 486 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit 487 * nanoseconds. 488 */ 489 switch (po->tp_version) { 490 case TPACKET_V1: 491 h.h1->tp_sec = ts.tv_sec; 492 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 493 break; 494 case TPACKET_V2: 495 h.h2->tp_sec = ts.tv_sec; 496 h.h2->tp_nsec = ts.tv_nsec; 497 break; 498 case TPACKET_V3: 499 h.h3->tp_sec = ts.tv_sec; 500 h.h3->tp_nsec = ts.tv_nsec; 501 break; 502 default: 503 WARN(1, "TPACKET version not supported.\n"); 504 BUG(); 505 } 506 507 /* one flush is safe, as both fields always lie on the same cacheline */ 508 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 509 smp_wmb(); 510 511 return ts_status; 512 } 513 514 static void *packet_lookup_frame(const struct packet_sock *po, 515 const struct packet_ring_buffer *rb, 516 unsigned int position, 517 int status) 518 { 519 unsigned int pg_vec_pos, frame_offset; 520 union tpacket_uhdr h; 521 522 pg_vec_pos = position / rb->frames_per_block; 523 frame_offset = position % rb->frames_per_block; 524 525 h.raw = rb->pg_vec[pg_vec_pos].buffer + 526 (frame_offset * rb->frame_size); 527 528 if (status != __packet_get_status(po, h.raw)) 529 return NULL; 530 531 return h.raw; 532 } 533 534 static void *packet_current_frame(struct packet_sock *po, 535 struct packet_ring_buffer *rb, 536 int status) 537 { 538 return packet_lookup_frame(po, rb, rb->head, status); 539 } 540 541 static u16 vlan_get_tci(const struct sk_buff *skb, struct net_device *dev) 542 { 543 struct vlan_hdr vhdr, *vh; 544 unsigned int header_len; 545 546 if (!dev) 547 return 0; 548 549 /* In the SOCK_DGRAM scenario, skb data starts at the network 550 * protocol, which is after the VLAN headers. The outer VLAN 551 * header is at the hard_header_len offset in non-variable 552 * length link layer headers. If it's a VLAN device, the 553 * min_header_len should be used to exclude the VLAN header 554 * size. 555 */ 556 if (dev->min_header_len == dev->hard_header_len) 557 header_len = dev->hard_header_len; 558 else if (is_vlan_dev(dev)) 559 header_len = dev->min_header_len; 560 else 561 return 0; 562 563 vh = skb_header_pointer(skb, skb_mac_offset(skb) + header_len, 564 sizeof(vhdr), &vhdr); 565 if (unlikely(!vh)) 566 return 0; 567 568 return ntohs(vh->h_vlan_TCI); 569 } 570 571 static __be16 vlan_get_protocol_dgram(const struct sk_buff *skb) 572 { 573 __be16 proto = skb->protocol; 574 575 if (unlikely(eth_type_vlan(proto))) 576 proto = vlan_get_protocol_offset_inline(skb, proto, 577 skb_mac_offset(skb), 578 NULL); 579 580 return proto; 581 } 582 583 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 584 struct sk_buff_head *rb_queue) 585 { 586 struct tpacket_kbdq_core *pkc; 587 588 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 589 hrtimer_cancel(&pkc->retire_blk_timer); 590 } 591 592 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 593 int blk_size_in_bytes) 594 { 595 struct net_device *dev; 596 unsigned int mbits, div; 597 struct ethtool_link_ksettings ecmd; 598 int err; 599 600 rtnl_lock(); 601 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 602 if (unlikely(!dev)) { 603 rtnl_unlock(); 604 return DEFAULT_PRB_RETIRE_TOV; 605 } 606 err = __ethtool_get_link_ksettings(dev, &ecmd); 607 rtnl_unlock(); 608 if (err) 609 return DEFAULT_PRB_RETIRE_TOV; 610 611 /* If the link speed is so slow you don't really 612 * need to worry about perf anyways 613 */ 614 if (ecmd.base.speed < SPEED_1000 || 615 ecmd.base.speed == SPEED_UNKNOWN) 616 return DEFAULT_PRB_RETIRE_TOV; 617 618 div = ecmd.base.speed / 1000; 619 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 620 621 if (div) 622 mbits /= div; 623 624 if (div) 625 return mbits + 1; 626 return mbits; 627 } 628 629 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 630 union tpacket_req_u *req_u) 631 { 632 p1->feature_req_word = req_u->req3.tp_feature_req_word; 633 } 634 635 static void init_prb_bdqc(struct packet_sock *po, 636 struct packet_ring_buffer *rb, 637 struct pgv *pg_vec, 638 union tpacket_req_u *req_u) 639 { 640 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 641 struct tpacket_block_desc *pbd; 642 643 memset(p1, 0x0, sizeof(*p1)); 644 645 p1->knxt_seq_num = 1; 646 p1->pkbdq = pg_vec; 647 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 648 p1->pkblk_start = pg_vec[0].buffer; 649 p1->kblk_size = req_u->req3.tp_block_size; 650 p1->knum_blocks = req_u->req3.tp_block_nr; 651 p1->hdrlen = po->tp_hdrlen; 652 p1->version = po->tp_version; 653 po->stats.stats3.tp_freeze_q_cnt = 0; 654 if (req_u->req3.tp_retire_blk_tov) 655 p1->interval_ktime = ms_to_ktime(req_u->req3.tp_retire_blk_tov); 656 else 657 p1->interval_ktime = ms_to_ktime(prb_calc_retire_blk_tmo(po, 658 req_u->req3.tp_block_size)); 659 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 660 rwlock_init(&p1->blk_fill_in_prog_lock); 661 662 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 663 prb_init_ft_ops(p1, req_u); 664 hrtimer_setup(&p1->retire_blk_timer, prb_retire_rx_blk_timer_expired, 665 CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); 666 hrtimer_start(&p1->retire_blk_timer, p1->interval_ktime, 667 HRTIMER_MODE_REL_SOFT); 668 prb_open_block(p1, pbd); 669 } 670 671 /* 672 * With a 1MB block-size, on a 1Gbps line, it will take 673 * i) ~8 ms to fill a block + ii) memcpy etc. 674 * In this cut we are not accounting for the memcpy time. 675 * 676 * Since the tmo granularity is in msecs, it is not too expensive 677 * to refresh the timer, lets say every '8' msecs. 678 * Either the user can set the 'tmo' or we can derive it based on 679 * a) line-speed and b) block-size. 680 * prb_calc_retire_blk_tmo() calculates the tmo. 681 */ 682 static enum hrtimer_restart prb_retire_rx_blk_timer_expired(struct hrtimer *t) 683 { 684 struct packet_sock *po = 685 timer_container_of(po, t, rx_ring.prb_bdqc.retire_blk_timer); 686 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 687 unsigned int frozen; 688 struct tpacket_block_desc *pbd; 689 690 spin_lock(&po->sk.sk_receive_queue.lock); 691 692 frozen = prb_queue_frozen(pkc); 693 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 694 695 /* We only need to plug the race when the block is partially filled. 696 * tpacket_rcv: 697 * lock(); increment BLOCK_NUM_PKTS; unlock() 698 * copy_bits() is in progress ... 699 * timer fires on other cpu: 700 * we can't retire the current block because copy_bits 701 * is in progress. 702 * 703 */ 704 if (BLOCK_NUM_PKTS(pbd)) { 705 /* Waiting for skb_copy_bits to finish... */ 706 write_lock(&pkc->blk_fill_in_prog_lock); 707 write_unlock(&pkc->blk_fill_in_prog_lock); 708 } 709 710 if (!frozen) { 711 if (BLOCK_NUM_PKTS(pbd)) { 712 /* Not an empty block. Need retire the block. */ 713 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 714 prb_dispatch_next_block(pkc, po); 715 } 716 } else { 717 /* Case 1. Queue was frozen because user-space was 718 * lagging behind. 719 */ 720 if (!prb_curr_blk_in_use(pbd)) { 721 /* Case 2. queue was frozen,user-space caught up, 722 * now the link went idle && the timer fired. 723 * We don't have a block to close.So we open this 724 * block and restart the timer. 725 * opening a block thaws the queue,restarts timer 726 * Thawing/timer-refresh is a side effect. 727 */ 728 prb_open_block(pkc, pbd); 729 } 730 } 731 732 hrtimer_forward_now(&pkc->retire_blk_timer, pkc->interval_ktime); 733 spin_unlock(&po->sk.sk_receive_queue.lock); 734 return HRTIMER_RESTART; 735 } 736 737 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 738 struct tpacket_block_desc *pbd1, __u32 status) 739 { 740 /* Flush everything minus the block header */ 741 742 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 743 u8 *start, *end; 744 745 start = (u8 *)pbd1; 746 747 /* Skip the block header(we know header WILL fit in 4K) */ 748 start += PAGE_SIZE; 749 750 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 751 for (; start < end; start += PAGE_SIZE) 752 flush_dcache_page(pgv_to_page(start)); 753 754 smp_wmb(); 755 #endif 756 757 /* Now update the block status. */ 758 759 BLOCK_STATUS(pbd1) = status; 760 761 /* Flush the block header */ 762 763 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 764 start = (u8 *)pbd1; 765 flush_dcache_page(pgv_to_page(start)); 766 767 smp_wmb(); 768 #endif 769 } 770 771 /* 772 * Side effect: 773 * 774 * 1) flush the block 775 * 2) Increment active_blk_num 776 * 777 * Note:We DONT refresh the timer on purpose. 778 * Because almost always the next block will be opened. 779 */ 780 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 781 struct tpacket_block_desc *pbd1, 782 struct packet_sock *po, unsigned int stat) 783 { 784 __u32 status = TP_STATUS_USER | stat; 785 786 struct tpacket3_hdr *last_pkt; 787 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 788 struct sock *sk = &po->sk; 789 790 if (atomic_read(&po->tp_drops)) 791 status |= TP_STATUS_LOSING; 792 793 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 794 last_pkt->tp_next_offset = 0; 795 796 /* Get the ts of the last pkt */ 797 if (BLOCK_NUM_PKTS(pbd1)) { 798 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 799 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 800 } else { 801 /* Ok, we tmo'd - so get the current time. 802 * 803 * It shouldn't really happen as we don't close empty 804 * blocks. See prb_retire_rx_blk_timer_expired(). 805 */ 806 struct timespec64 ts; 807 ktime_get_real_ts64(&ts); 808 h1->ts_last_pkt.ts_sec = ts.tv_sec; 809 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 810 } 811 812 smp_wmb(); 813 814 /* Flush the block */ 815 prb_flush_block(pkc1, pbd1, status); 816 817 sk->sk_data_ready(sk); 818 819 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 820 } 821 822 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 823 { 824 pkc->reset_pending_on_curr_blk = 0; 825 } 826 827 /* 828 * prb_open_block is called by tpacket_rcv or timer callback. 829 * 830 * Reasons why NOT update hrtimer in prb_open_block: 831 * 1) It will increase complexity to distinguish the two caller scenario. 832 * 2) hrtimer_cancel and hrtimer_start need to be called if you want to update 833 * TMO of an already enqueued hrtimer, leading to complex shutdown logic. 834 * 835 * One side effect of NOT update hrtimer when called by tpacket_rcv is that 836 * a newly opened block triggered by tpacket_rcv may be retired earlier than 837 * expected. On the other hand, if timeout is updated in prb_open_block, the 838 * frequent reception of network packets that leads to prb_open_block being 839 * called may cause hrtimer to be removed and enqueued repeatedly. 840 */ 841 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 842 struct tpacket_block_desc *pbd1) 843 { 844 struct timespec64 ts; 845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 846 847 smp_rmb(); 848 849 /* We could have just memset this but we will lose the 850 * flexibility of making the priv area sticky 851 */ 852 853 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 854 BLOCK_NUM_PKTS(pbd1) = 0; 855 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 856 857 ktime_get_real_ts64(&ts); 858 859 h1->ts_first_pkt.ts_sec = ts.tv_sec; 860 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 861 862 pkc1->pkblk_start = (char *)pbd1; 863 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 864 865 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 866 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 867 868 pbd1->version = pkc1->version; 869 pkc1->prev = pkc1->nxt_offset; 870 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 871 872 prb_thaw_queue(pkc1); 873 874 smp_wmb(); 875 } 876 877 /* 878 * Queue freeze logic: 879 * 1) Assume tp_block_nr = 8 blocks. 880 * 2) At time 't0', user opens Rx ring. 881 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 882 * 4) user-space is either sleeping or processing block '0'. 883 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 884 * it will close block-7,loop around and try to fill block '0'. 885 * call-flow: 886 * __packet_lookup_frame_in_block 887 * prb_retire_current_block() 888 * prb_dispatch_next_block() 889 * |->(BLOCK_STATUS == USER) evaluates to true 890 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 891 * 6) Now there are two cases: 892 * 6.1) Link goes idle right after the queue is frozen. 893 * But remember, the last open_block() refreshed the timer. 894 * When this timer expires,it will refresh itself so that we can 895 * re-open block-0 in near future. 896 * 6.2) Link is busy and keeps on receiving packets. This is a simple 897 * case and __packet_lookup_frame_in_block will check if block-0 898 * is free and can now be re-used. 899 */ 900 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 901 struct packet_sock *po) 902 { 903 pkc->reset_pending_on_curr_blk = 1; 904 po->stats.stats3.tp_freeze_q_cnt++; 905 } 906 907 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 908 909 /* 910 * If the next block is free then we will dispatch it 911 * and return a good offset. 912 * Else, we will freeze the queue. 913 * So, caller must check the return value. 914 */ 915 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 916 struct packet_sock *po) 917 { 918 struct tpacket_block_desc *pbd; 919 920 smp_rmb(); 921 922 /* 1. Get current block num */ 923 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 924 925 /* 2. If this block is currently in_use then freeze the queue */ 926 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 927 prb_freeze_queue(pkc, po); 928 return NULL; 929 } 930 931 /* 932 * 3. 933 * open this block and return the offset where the first packet 934 * needs to get stored. 935 */ 936 prb_open_block(pkc, pbd); 937 return (void *)pkc->nxt_offset; 938 } 939 940 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 941 struct packet_sock *po, unsigned int status) 942 { 943 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 944 945 /* retire/close the current block */ 946 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 947 /* 948 * Plug the case where copy_bits() is in progress on 949 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 950 * have space to copy the pkt in the current block and 951 * called prb_retire_current_block() 952 * 953 * We don't need to worry about the TMO case because 954 * the timer-handler already handled this case. 955 */ 956 if (!(status & TP_STATUS_BLK_TMO)) { 957 /* Waiting for skb_copy_bits to finish... */ 958 write_lock(&pkc->blk_fill_in_prog_lock); 959 write_unlock(&pkc->blk_fill_in_prog_lock); 960 } 961 prb_close_block(pkc, pbd, po, status); 962 return; 963 } 964 } 965 966 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) 967 { 968 return TP_STATUS_USER & BLOCK_STATUS(pbd); 969 } 970 971 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 972 { 973 return pkc->reset_pending_on_curr_blk; 974 } 975 976 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 977 __releases(&pkc->blk_fill_in_prog_lock) 978 { 979 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 980 981 read_unlock(&pkc->blk_fill_in_prog_lock); 982 } 983 984 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 985 struct tpacket3_hdr *ppd) 986 { 987 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 988 } 989 990 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 991 struct tpacket3_hdr *ppd) 992 { 993 ppd->hv1.tp_rxhash = 0; 994 } 995 996 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 997 struct tpacket3_hdr *ppd) 998 { 999 struct packet_sock *po = container_of(pkc, struct packet_sock, rx_ring.prb_bdqc); 1000 1001 if (skb_vlan_tag_present(pkc->skb)) { 1002 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1003 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1004 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1005 } else if (unlikely(po->sk.sk_type == SOCK_DGRAM && eth_type_vlan(pkc->skb->protocol))) { 1006 ppd->hv1.tp_vlan_tci = vlan_get_tci(pkc->skb, pkc->skb->dev); 1007 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->protocol); 1008 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1009 } else { 1010 ppd->hv1.tp_vlan_tci = 0; 1011 ppd->hv1.tp_vlan_tpid = 0; 1012 ppd->tp_status = TP_STATUS_AVAILABLE; 1013 } 1014 } 1015 1016 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1017 struct tpacket3_hdr *ppd) 1018 { 1019 ppd->hv1.tp_padding = 0; 1020 prb_fill_vlan_info(pkc, ppd); 1021 1022 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1023 prb_fill_rxhash(pkc, ppd); 1024 else 1025 prb_clear_rxhash(pkc, ppd); 1026 } 1027 1028 static void prb_fill_curr_block(char *curr, 1029 struct tpacket_kbdq_core *pkc, 1030 struct tpacket_block_desc *pbd, 1031 unsigned int len) 1032 __acquires(&pkc->blk_fill_in_prog_lock) 1033 { 1034 struct tpacket3_hdr *ppd; 1035 1036 ppd = (struct tpacket3_hdr *)curr; 1037 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1038 pkc->prev = curr; 1039 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1040 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1041 BLOCK_NUM_PKTS(pbd) += 1; 1042 read_lock(&pkc->blk_fill_in_prog_lock); 1043 prb_run_all_ft_ops(pkc, ppd); 1044 } 1045 1046 /* Assumes caller has the sk->rx_queue.lock */ 1047 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1048 struct sk_buff *skb, 1049 unsigned int len 1050 ) 1051 { 1052 struct tpacket_kbdq_core *pkc; 1053 struct tpacket_block_desc *pbd; 1054 char *curr, *end; 1055 1056 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1057 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1058 1059 /* Queue is frozen when user space is lagging behind */ 1060 if (prb_queue_frozen(pkc)) { 1061 /* 1062 * Check if that last block which caused the queue to freeze, 1063 * is still in_use by user-space. 1064 */ 1065 if (prb_curr_blk_in_use(pbd)) { 1066 /* Can't record this packet */ 1067 return NULL; 1068 } else { 1069 /* 1070 * Ok, the block was released by user-space. 1071 * Now let's open that block. 1072 * opening a block also thaws the queue. 1073 * Thawing is a side effect. 1074 */ 1075 prb_open_block(pkc, pbd); 1076 } 1077 } 1078 1079 smp_mb(); 1080 curr = pkc->nxt_offset; 1081 pkc->skb = skb; 1082 end = (char *)pbd + pkc->kblk_size; 1083 1084 /* first try the current block */ 1085 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1086 prb_fill_curr_block(curr, pkc, pbd, len); 1087 return (void *)curr; 1088 } 1089 1090 /* Ok, close the current block */ 1091 prb_retire_current_block(pkc, po, 0); 1092 1093 /* Now, try to dispatch the next block */ 1094 curr = (char *)prb_dispatch_next_block(pkc, po); 1095 if (curr) { 1096 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1097 prb_fill_curr_block(curr, pkc, pbd, len); 1098 return (void *)curr; 1099 } 1100 1101 /* 1102 * No free blocks are available.user_space hasn't caught up yet. 1103 * Queue was just frozen and now this packet will get dropped. 1104 */ 1105 return NULL; 1106 } 1107 1108 static void *packet_current_rx_frame(struct packet_sock *po, 1109 struct sk_buff *skb, 1110 int status, unsigned int len) 1111 { 1112 char *curr = NULL; 1113 switch (po->tp_version) { 1114 case TPACKET_V1: 1115 case TPACKET_V2: 1116 curr = packet_lookup_frame(po, &po->rx_ring, 1117 po->rx_ring.head, status); 1118 return curr; 1119 case TPACKET_V3: 1120 return __packet_lookup_frame_in_block(po, skb, len); 1121 default: 1122 WARN(1, "TPACKET version not supported\n"); 1123 BUG(); 1124 return NULL; 1125 } 1126 } 1127 1128 static void *prb_lookup_block(const struct packet_sock *po, 1129 const struct packet_ring_buffer *rb, 1130 unsigned int idx, 1131 int status) 1132 { 1133 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1134 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1135 1136 if (status != BLOCK_STATUS(pbd)) 1137 return NULL; 1138 return pbd; 1139 } 1140 1141 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1142 { 1143 unsigned int prev; 1144 if (rb->prb_bdqc.kactive_blk_num) 1145 prev = rb->prb_bdqc.kactive_blk_num-1; 1146 else 1147 prev = rb->prb_bdqc.knum_blocks-1; 1148 return prev; 1149 } 1150 1151 /* Assumes caller has held the rx_queue.lock */ 1152 static void *__prb_previous_block(struct packet_sock *po, 1153 struct packet_ring_buffer *rb, 1154 int status) 1155 { 1156 unsigned int previous = prb_previous_blk_num(rb); 1157 return prb_lookup_block(po, rb, previous, status); 1158 } 1159 1160 static void *packet_previous_rx_frame(struct packet_sock *po, 1161 struct packet_ring_buffer *rb, 1162 int status) 1163 { 1164 if (po->tp_version <= TPACKET_V2) 1165 return packet_previous_frame(po, rb, status); 1166 1167 return __prb_previous_block(po, rb, status); 1168 } 1169 1170 static void packet_increment_rx_head(struct packet_sock *po, 1171 struct packet_ring_buffer *rb) 1172 { 1173 switch (po->tp_version) { 1174 case TPACKET_V1: 1175 case TPACKET_V2: 1176 return packet_increment_head(rb); 1177 case TPACKET_V3: 1178 default: 1179 WARN(1, "TPACKET version not supported.\n"); 1180 BUG(); 1181 return; 1182 } 1183 } 1184 1185 static void *packet_previous_frame(struct packet_sock *po, 1186 struct packet_ring_buffer *rb, 1187 int status) 1188 { 1189 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1190 return packet_lookup_frame(po, rb, previous, status); 1191 } 1192 1193 static void packet_increment_head(struct packet_ring_buffer *buff) 1194 { 1195 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1196 } 1197 1198 static void packet_inc_pending(struct packet_ring_buffer *rb) 1199 { 1200 this_cpu_inc(*rb->pending_refcnt); 1201 } 1202 1203 static void packet_dec_pending(struct packet_ring_buffer *rb) 1204 { 1205 this_cpu_dec(*rb->pending_refcnt); 1206 } 1207 1208 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1209 { 1210 unsigned int refcnt = 0; 1211 int cpu; 1212 1213 /* We don't use pending refcount in rx_ring. */ 1214 if (rb->pending_refcnt == NULL) 1215 return 0; 1216 1217 for_each_possible_cpu(cpu) 1218 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1219 1220 return refcnt; 1221 } 1222 1223 static int packet_alloc_pending(struct packet_sock *po) 1224 { 1225 po->rx_ring.pending_refcnt = NULL; 1226 1227 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1228 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1229 return -ENOBUFS; 1230 1231 return 0; 1232 } 1233 1234 static void packet_free_pending(struct packet_sock *po) 1235 { 1236 free_percpu(po->tx_ring.pending_refcnt); 1237 } 1238 1239 #define ROOM_POW_OFF 2 1240 #define ROOM_NONE 0x0 1241 #define ROOM_LOW 0x1 1242 #define ROOM_NORMAL 0x2 1243 1244 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) 1245 { 1246 int idx, len; 1247 1248 len = READ_ONCE(po->rx_ring.frame_max) + 1; 1249 idx = READ_ONCE(po->rx_ring.head); 1250 if (pow_off) 1251 idx += len >> pow_off; 1252 if (idx >= len) 1253 idx -= len; 1254 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1255 } 1256 1257 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) 1258 { 1259 int idx, len; 1260 1261 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); 1262 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); 1263 if (pow_off) 1264 idx += len >> pow_off; 1265 if (idx >= len) 1266 idx -= len; 1267 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1268 } 1269 1270 static int __packet_rcv_has_room(const struct packet_sock *po, 1271 const struct sk_buff *skb) 1272 { 1273 const struct sock *sk = &po->sk; 1274 int ret = ROOM_NONE; 1275 1276 if (po->prot_hook.func != tpacket_rcv) { 1277 int rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1278 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1279 - (skb ? skb->truesize : 0); 1280 1281 if (avail > (rcvbuf >> ROOM_POW_OFF)) 1282 return ROOM_NORMAL; 1283 else if (avail > 0) 1284 return ROOM_LOW; 1285 else 1286 return ROOM_NONE; 1287 } 1288 1289 if (po->tp_version == TPACKET_V3) { 1290 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1291 ret = ROOM_NORMAL; 1292 else if (__tpacket_v3_has_room(po, 0)) 1293 ret = ROOM_LOW; 1294 } else { 1295 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1296 ret = ROOM_NORMAL; 1297 else if (__tpacket_has_room(po, 0)) 1298 ret = ROOM_LOW; 1299 } 1300 1301 return ret; 1302 } 1303 1304 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1305 { 1306 bool pressure; 1307 int ret; 1308 1309 ret = __packet_rcv_has_room(po, skb); 1310 pressure = ret != ROOM_NORMAL; 1311 1312 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure) 1313 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure); 1314 1315 return ret; 1316 } 1317 1318 static void __packet_rcv_try_clear_pressure(struct packet_sock *po) 1319 { 1320 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) && 1321 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 1322 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false); 1323 } 1324 1325 static void packet_rcv_try_clear_pressure(struct packet_sock *po) 1326 { 1327 struct sock *sk = &po->sk; 1328 1329 if (!packet_sock_flag(po, PACKET_SOCK_PRESSURE)) 1330 return; 1331 1332 spin_lock_bh(&sk->sk_receive_queue.lock); 1333 __packet_rcv_try_clear_pressure(po); 1334 spin_unlock_bh(&sk->sk_receive_queue.lock); 1335 } 1336 1337 static void packet_sock_destruct(struct sock *sk) 1338 { 1339 skb_queue_purge(&sk->sk_error_queue); 1340 1341 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1342 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1343 1344 if (!sock_flag(sk, SOCK_DEAD)) { 1345 pr_err("Attempt to release alive packet socket: %p\n", sk); 1346 return; 1347 } 1348 } 1349 1350 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1351 { 1352 u32 *history = po->rollover->history; 1353 u32 victim, rxhash; 1354 int i, count = 0; 1355 1356 rxhash = skb_get_hash(skb); 1357 for (i = 0; i < ROLLOVER_HLEN; i++) 1358 if (READ_ONCE(history[i]) == rxhash) 1359 count++; 1360 1361 victim = get_random_u32_below(ROLLOVER_HLEN); 1362 1363 /* Avoid dirtying the cache line if possible */ 1364 if (READ_ONCE(history[victim]) != rxhash) 1365 WRITE_ONCE(history[victim], rxhash); 1366 1367 return count > (ROLLOVER_HLEN >> 1); 1368 } 1369 1370 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1371 struct sk_buff *skb, 1372 unsigned int num) 1373 { 1374 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1375 } 1376 1377 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1378 struct sk_buff *skb, 1379 unsigned int num) 1380 { 1381 unsigned int val = atomic_inc_return(&f->rr_cur); 1382 1383 return val % num; 1384 } 1385 1386 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1387 struct sk_buff *skb, 1388 unsigned int num) 1389 { 1390 return smp_processor_id() % num; 1391 } 1392 1393 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1394 struct sk_buff *skb, 1395 unsigned int num) 1396 { 1397 return get_random_u32_below(num); 1398 } 1399 1400 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1401 struct sk_buff *skb, 1402 unsigned int idx, bool try_self, 1403 unsigned int num) 1404 { 1405 struct packet_sock *po, *po_next, *po_skip = NULL; 1406 unsigned int i, j, room = ROOM_NONE; 1407 1408 po = pkt_sk(rcu_dereference(f->arr[idx])); 1409 1410 if (try_self) { 1411 room = packet_rcv_has_room(po, skb); 1412 if (room == ROOM_NORMAL || 1413 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1414 return idx; 1415 po_skip = po; 1416 } 1417 1418 i = j = min_t(int, po->rollover->sock, num - 1); 1419 do { 1420 po_next = pkt_sk(rcu_dereference(f->arr[i])); 1421 if (po_next != po_skip && 1422 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) && 1423 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1424 if (i != j) 1425 po->rollover->sock = i; 1426 atomic_long_inc(&po->rollover->num); 1427 if (room == ROOM_LOW) 1428 atomic_long_inc(&po->rollover->num_huge); 1429 return i; 1430 } 1431 1432 if (++i == num) 1433 i = 0; 1434 } while (i != j); 1435 1436 atomic_long_inc(&po->rollover->num_failed); 1437 return idx; 1438 } 1439 1440 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1441 struct sk_buff *skb, 1442 unsigned int num) 1443 { 1444 return skb_get_queue_mapping(skb) % num; 1445 } 1446 1447 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1448 struct sk_buff *skb, 1449 unsigned int num) 1450 { 1451 struct bpf_prog *prog; 1452 unsigned int ret = 0; 1453 1454 rcu_read_lock(); 1455 prog = rcu_dereference(f->bpf_prog); 1456 if (prog) 1457 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1458 rcu_read_unlock(); 1459 1460 return ret; 1461 } 1462 1463 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1464 { 1465 return f->flags & (flag >> 8); 1466 } 1467 1468 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1469 struct packet_type *pt, struct net_device *orig_dev) 1470 { 1471 struct packet_fanout *f = pt->af_packet_priv; 1472 unsigned int num = READ_ONCE(f->num_members); 1473 struct net *net = read_pnet(&f->net); 1474 struct packet_sock *po; 1475 unsigned int idx; 1476 1477 if (!net_eq(dev_net(dev), net) || !num) { 1478 kfree_skb(skb); 1479 return 0; 1480 } 1481 1482 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1483 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1484 if (!skb) 1485 return 0; 1486 } 1487 switch (f->type) { 1488 case PACKET_FANOUT_HASH: 1489 default: 1490 idx = fanout_demux_hash(f, skb, num); 1491 break; 1492 case PACKET_FANOUT_LB: 1493 idx = fanout_demux_lb(f, skb, num); 1494 break; 1495 case PACKET_FANOUT_CPU: 1496 idx = fanout_demux_cpu(f, skb, num); 1497 break; 1498 case PACKET_FANOUT_RND: 1499 idx = fanout_demux_rnd(f, skb, num); 1500 break; 1501 case PACKET_FANOUT_QM: 1502 idx = fanout_demux_qm(f, skb, num); 1503 break; 1504 case PACKET_FANOUT_ROLLOVER: 1505 idx = fanout_demux_rollover(f, skb, 0, false, num); 1506 break; 1507 case PACKET_FANOUT_CBPF: 1508 case PACKET_FANOUT_EBPF: 1509 idx = fanout_demux_bpf(f, skb, num); 1510 break; 1511 } 1512 1513 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1514 idx = fanout_demux_rollover(f, skb, idx, true, num); 1515 1516 po = pkt_sk(rcu_dereference(f->arr[idx])); 1517 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1518 } 1519 1520 DEFINE_MUTEX(fanout_mutex); 1521 EXPORT_SYMBOL_GPL(fanout_mutex); 1522 static LIST_HEAD(fanout_list); 1523 static u16 fanout_next_id; 1524 1525 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1526 { 1527 struct packet_fanout *f = po->fanout; 1528 1529 spin_lock(&f->lock); 1530 rcu_assign_pointer(f->arr[f->num_members], sk); 1531 smp_wmb(); 1532 f->num_members++; 1533 if (f->num_members == 1) 1534 dev_add_pack(&f->prot_hook); 1535 spin_unlock(&f->lock); 1536 } 1537 1538 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1539 { 1540 struct packet_fanout *f = po->fanout; 1541 int i; 1542 1543 spin_lock(&f->lock); 1544 for (i = 0; i < f->num_members; i++) { 1545 if (rcu_dereference_protected(f->arr[i], 1546 lockdep_is_held(&f->lock)) == sk) 1547 break; 1548 } 1549 BUG_ON(i >= f->num_members); 1550 rcu_assign_pointer(f->arr[i], 1551 rcu_dereference_protected(f->arr[f->num_members - 1], 1552 lockdep_is_held(&f->lock))); 1553 f->num_members--; 1554 if (f->num_members == 0) 1555 __dev_remove_pack(&f->prot_hook); 1556 spin_unlock(&f->lock); 1557 } 1558 1559 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1560 { 1561 if (sk->sk_family != PF_PACKET) 1562 return false; 1563 1564 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1565 } 1566 1567 static void fanout_init_data(struct packet_fanout *f) 1568 { 1569 switch (f->type) { 1570 case PACKET_FANOUT_LB: 1571 atomic_set(&f->rr_cur, 0); 1572 break; 1573 case PACKET_FANOUT_CBPF: 1574 case PACKET_FANOUT_EBPF: 1575 RCU_INIT_POINTER(f->bpf_prog, NULL); 1576 break; 1577 } 1578 } 1579 1580 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1581 { 1582 struct bpf_prog *old; 1583 1584 spin_lock(&f->lock); 1585 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1586 rcu_assign_pointer(f->bpf_prog, new); 1587 spin_unlock(&f->lock); 1588 1589 if (old) { 1590 synchronize_net(); 1591 bpf_prog_destroy(old); 1592 } 1593 } 1594 1595 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, 1596 unsigned int len) 1597 { 1598 struct bpf_prog *new; 1599 struct sock_fprog fprog; 1600 int ret; 1601 1602 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1603 return -EPERM; 1604 1605 ret = copy_bpf_fprog_from_user(&fprog, data, len); 1606 if (ret) 1607 return ret; 1608 1609 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1610 if (ret) 1611 return ret; 1612 1613 __fanout_set_data_bpf(po->fanout, new); 1614 return 0; 1615 } 1616 1617 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, 1618 unsigned int len) 1619 { 1620 struct bpf_prog *new; 1621 u32 fd; 1622 1623 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1624 return -EPERM; 1625 if (len != sizeof(fd)) 1626 return -EINVAL; 1627 if (copy_from_sockptr(&fd, data, len)) 1628 return -EFAULT; 1629 1630 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1631 if (IS_ERR(new)) 1632 return PTR_ERR(new); 1633 1634 __fanout_set_data_bpf(po->fanout, new); 1635 return 0; 1636 } 1637 1638 static int fanout_set_data(struct packet_sock *po, sockptr_t data, 1639 unsigned int len) 1640 { 1641 switch (po->fanout->type) { 1642 case PACKET_FANOUT_CBPF: 1643 return fanout_set_data_cbpf(po, data, len); 1644 case PACKET_FANOUT_EBPF: 1645 return fanout_set_data_ebpf(po, data, len); 1646 default: 1647 return -EINVAL; 1648 } 1649 } 1650 1651 static void fanout_release_data(struct packet_fanout *f) 1652 { 1653 switch (f->type) { 1654 case PACKET_FANOUT_CBPF: 1655 case PACKET_FANOUT_EBPF: 1656 __fanout_set_data_bpf(f, NULL); 1657 } 1658 } 1659 1660 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1661 { 1662 struct packet_fanout *f; 1663 1664 list_for_each_entry(f, &fanout_list, list) { 1665 if (f->id == candidate_id && 1666 read_pnet(&f->net) == sock_net(sk)) { 1667 return false; 1668 } 1669 } 1670 return true; 1671 } 1672 1673 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1674 { 1675 u16 id = fanout_next_id; 1676 1677 do { 1678 if (__fanout_id_is_free(sk, id)) { 1679 *new_id = id; 1680 fanout_next_id = id + 1; 1681 return true; 1682 } 1683 1684 id++; 1685 } while (id != fanout_next_id); 1686 1687 return false; 1688 } 1689 1690 static int fanout_add(struct sock *sk, struct fanout_args *args) 1691 { 1692 struct packet_rollover *rollover = NULL; 1693 struct packet_sock *po = pkt_sk(sk); 1694 u16 type_flags = args->type_flags; 1695 struct packet_fanout *f, *match; 1696 u8 type = type_flags & 0xff; 1697 u8 flags = type_flags >> 8; 1698 u16 id = args->id; 1699 int err; 1700 1701 switch (type) { 1702 case PACKET_FANOUT_ROLLOVER: 1703 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1704 return -EINVAL; 1705 break; 1706 case PACKET_FANOUT_HASH: 1707 case PACKET_FANOUT_LB: 1708 case PACKET_FANOUT_CPU: 1709 case PACKET_FANOUT_RND: 1710 case PACKET_FANOUT_QM: 1711 case PACKET_FANOUT_CBPF: 1712 case PACKET_FANOUT_EBPF: 1713 break; 1714 default: 1715 return -EINVAL; 1716 } 1717 1718 mutex_lock(&fanout_mutex); 1719 1720 err = -EALREADY; 1721 if (po->fanout) 1722 goto out; 1723 1724 if (type == PACKET_FANOUT_ROLLOVER || 1725 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1726 err = -ENOMEM; 1727 rollover = kzalloc_obj(*rollover); 1728 if (!rollover) 1729 goto out; 1730 atomic_long_set(&rollover->num, 0); 1731 atomic_long_set(&rollover->num_huge, 0); 1732 atomic_long_set(&rollover->num_failed, 0); 1733 } 1734 1735 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1736 if (id != 0) { 1737 err = -EINVAL; 1738 goto out; 1739 } 1740 if (!fanout_find_new_id(sk, &id)) { 1741 err = -ENOMEM; 1742 goto out; 1743 } 1744 /* ephemeral flag for the first socket in the group: drop it */ 1745 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1746 } 1747 1748 match = NULL; 1749 list_for_each_entry(f, &fanout_list, list) { 1750 if (f->id == id && 1751 read_pnet(&f->net) == sock_net(sk)) { 1752 match = f; 1753 break; 1754 } 1755 } 1756 err = -EINVAL; 1757 if (match) { 1758 if (match->flags != flags) 1759 goto out; 1760 if (args->max_num_members && 1761 args->max_num_members != match->max_num_members) 1762 goto out; 1763 } else { 1764 if (args->max_num_members > PACKET_FANOUT_MAX) 1765 goto out; 1766 if (!args->max_num_members) 1767 /* legacy PACKET_FANOUT_MAX */ 1768 args->max_num_members = 256; 1769 err = -ENOMEM; 1770 match = kvzalloc_flex(*match, arr, args->max_num_members); 1771 if (!match) 1772 goto out; 1773 write_pnet(&match->net, sock_net(sk)); 1774 match->id = id; 1775 match->type = type; 1776 match->flags = flags; 1777 INIT_LIST_HEAD(&match->list); 1778 spin_lock_init(&match->lock); 1779 refcount_set(&match->sk_ref, 0); 1780 fanout_init_data(match); 1781 match->prot_hook.type = po->prot_hook.type; 1782 match->prot_hook.dev = po->prot_hook.dev; 1783 match->prot_hook.func = packet_rcv_fanout; 1784 match->prot_hook.af_packet_priv = match; 1785 match->prot_hook.af_packet_net = read_pnet(&match->net); 1786 match->prot_hook.id_match = match_fanout_group; 1787 match->max_num_members = args->max_num_members; 1788 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; 1789 list_add(&match->list, &fanout_list); 1790 } 1791 err = -EINVAL; 1792 1793 spin_lock(&po->bind_lock); 1794 if (po->num && 1795 match->type == type && 1796 match->prot_hook.type == po->prot_hook.type && 1797 match->prot_hook.dev == po->prot_hook.dev) { 1798 err = -ENOSPC; 1799 if (refcount_read(&match->sk_ref) < match->max_num_members) { 1800 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1801 WRITE_ONCE(po->fanout, match); 1802 1803 po->rollover = rollover; 1804 rollover = NULL; 1805 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1806 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 1807 __dev_remove_pack(&po->prot_hook); 1808 __fanout_link(sk, po); 1809 } 1810 err = 0; 1811 } 1812 } 1813 spin_unlock(&po->bind_lock); 1814 1815 if (err && !refcount_read(&match->sk_ref)) { 1816 list_del(&match->list); 1817 kvfree(match); 1818 } 1819 1820 out: 1821 kfree(rollover); 1822 mutex_unlock(&fanout_mutex); 1823 return err; 1824 } 1825 1826 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1827 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1828 * It is the responsibility of the caller to call fanout_release_data() and 1829 * free the returned packet_fanout (after synchronize_net()) 1830 */ 1831 static struct packet_fanout *fanout_release(struct sock *sk) 1832 { 1833 struct packet_sock *po = pkt_sk(sk); 1834 struct packet_fanout *f; 1835 1836 mutex_lock(&fanout_mutex); 1837 f = po->fanout; 1838 if (f) { 1839 po->fanout = NULL; 1840 1841 if (refcount_dec_and_test(&f->sk_ref)) 1842 list_del(&f->list); 1843 else 1844 f = NULL; 1845 } 1846 mutex_unlock(&fanout_mutex); 1847 1848 return f; 1849 } 1850 1851 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1852 struct sk_buff *skb) 1853 { 1854 /* Earlier code assumed this would be a VLAN pkt, double-check 1855 * this now that we have the actual packet in hand. We can only 1856 * do this check on Ethernet devices. 1857 */ 1858 if (unlikely(dev->type != ARPHRD_ETHER)) 1859 return false; 1860 1861 skb_reset_mac_header(skb); 1862 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1863 } 1864 1865 static const struct proto_ops packet_ops; 1866 1867 static const struct proto_ops packet_ops_spkt; 1868 1869 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1870 struct packet_type *pt, struct net_device *orig_dev) 1871 { 1872 struct sock *sk; 1873 struct sockaddr_pkt *spkt; 1874 1875 /* 1876 * When we registered the protocol we saved the socket in the data 1877 * field for just this event. 1878 */ 1879 1880 sk = pt->af_packet_priv; 1881 1882 /* 1883 * Yank back the headers [hope the device set this 1884 * right or kerboom...] 1885 * 1886 * Incoming packets have ll header pulled, 1887 * push it back. 1888 * 1889 * For outgoing ones skb->data == skb_mac_header(skb) 1890 * so that this procedure is noop. 1891 */ 1892 1893 if (skb->pkt_type == PACKET_LOOPBACK) 1894 goto out; 1895 1896 if (!net_eq(dev_net(dev), sock_net(sk))) 1897 goto out; 1898 1899 skb = skb_share_check(skb, GFP_ATOMIC); 1900 if (skb == NULL) 1901 goto oom; 1902 1903 /* drop any routing info */ 1904 skb_dst_drop(skb); 1905 1906 /* drop conntrack reference */ 1907 nf_reset_ct(skb); 1908 1909 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1910 1911 skb_push(skb, skb->data - skb_mac_header(skb)); 1912 1913 /* 1914 * The SOCK_PACKET socket receives _all_ frames. 1915 */ 1916 1917 spkt->spkt_family = dev->type; 1918 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1919 spkt->spkt_protocol = skb->protocol; 1920 1921 /* 1922 * Charge the memory to the socket. This is done specifically 1923 * to prevent sockets using all the memory up. 1924 */ 1925 1926 if (sock_queue_rcv_skb(sk, skb) == 0) 1927 return 0; 1928 1929 out: 1930 kfree_skb(skb); 1931 oom: 1932 return 0; 1933 } 1934 1935 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1936 { 1937 int depth; 1938 1939 /* On TX skb->data is the L2 header; anchor it for all socket types. */ 1940 skb_reset_mac_header(skb); 1941 1942 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1943 sock->type == SOCK_RAW) 1944 skb->protocol = dev_parse_header_protocol(skb); 1945 1946 /* Move network header to the right position for VLAN tagged packets */ 1947 if (likely(skb->dev->type == ARPHRD_ETHER) && 1948 eth_type_vlan(skb->protocol) && 1949 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 1950 skb_set_network_header(skb, depth); 1951 1952 skb_probe_transport_header(skb); 1953 } 1954 1955 /* 1956 * Output a raw packet to a device layer. This bypasses all the other 1957 * protocol layers and you must therefore supply it with a complete frame 1958 */ 1959 1960 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1961 size_t len) 1962 { 1963 struct sock *sk = sock->sk; 1964 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1965 struct sk_buff *skb = NULL; 1966 struct net_device *dev; 1967 struct sockcm_cookie sockc; 1968 __be16 proto = 0; 1969 int err; 1970 int extra_len = 0; 1971 1972 /* 1973 * Get and verify the address. 1974 */ 1975 1976 if (saddr) { 1977 if (msg->msg_namelen < sizeof(struct sockaddr)) 1978 return -EINVAL; 1979 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1980 proto = saddr->spkt_protocol; 1981 } else 1982 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1983 1984 /* 1985 * Find the device first to size check it 1986 */ 1987 1988 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1989 retry: 1990 rcu_read_lock(); 1991 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1992 err = -ENODEV; 1993 if (dev == NULL) 1994 goto out_unlock; 1995 1996 err = -ENETDOWN; 1997 if (!(dev->flags & IFF_UP)) 1998 goto out_unlock; 1999 2000 /* 2001 * You may not queue a frame bigger than the mtu. This is the lowest level 2002 * raw protocol and you must do your own fragmentation at this level. 2003 */ 2004 2005 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2006 if (!netif_supports_nofcs(dev)) { 2007 err = -EPROTONOSUPPORT; 2008 goto out_unlock; 2009 } 2010 extra_len = 4; /* We're doing our own CRC */ 2011 } 2012 2013 err = -EMSGSIZE; 2014 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 2015 goto out_unlock; 2016 2017 if (!skb) { 2018 size_t reserved = LL_RESERVED_SPACE(dev); 2019 int tlen = dev->needed_tailroom; 2020 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 2021 2022 rcu_read_unlock(); 2023 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2024 if (skb == NULL) 2025 return -ENOBUFS; 2026 /* FIXME: Save some space for broken drivers that write a hard 2027 * header at transmission time by themselves. PPP is the notable 2028 * one here. This should really be fixed at the driver level. 2029 */ 2030 skb_reserve(skb, reserved); 2031 skb_reset_network_header(skb); 2032 2033 /* Try to align data part correctly */ 2034 if (hhlen) { 2035 skb->data -= hhlen; 2036 skb->tail -= hhlen; 2037 if (len < hhlen) 2038 skb_reset_network_header(skb); 2039 } 2040 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2041 if (err) 2042 goto out_free; 2043 goto retry; 2044 } 2045 2046 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2047 err = -EINVAL; 2048 goto out_unlock; 2049 } 2050 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 2051 !packet_extra_vlan_len_allowed(dev, skb)) { 2052 err = -EMSGSIZE; 2053 goto out_unlock; 2054 } 2055 2056 sockcm_init(&sockc, sk); 2057 if (msg->msg_controllen) { 2058 err = sock_cmsg_send(sk, msg, &sockc); 2059 if (unlikely(err)) 2060 goto out_unlock; 2061 } 2062 2063 skb->protocol = proto; 2064 skb->dev = dev; 2065 skb->priority = sockc.priority; 2066 skb->mark = sockc.mark; 2067 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2068 skb_setup_tx_timestamp(skb, &sockc); 2069 2070 if (unlikely(extra_len == 4)) 2071 skb->no_fcs = 1; 2072 2073 packet_parse_headers(skb, sock); 2074 2075 dev_queue_xmit(skb); 2076 rcu_read_unlock(); 2077 return len; 2078 2079 out_unlock: 2080 rcu_read_unlock(); 2081 out_free: 2082 kfree_skb(skb); 2083 return err; 2084 } 2085 2086 static unsigned int run_filter(struct sk_buff *skb, 2087 const struct sock *sk, 2088 unsigned int res) 2089 { 2090 struct sk_filter *filter; 2091 2092 rcu_read_lock(); 2093 filter = rcu_dereference(sk->sk_filter); 2094 if (filter != NULL) 2095 res = bpf_prog_run_clear_cb(filter->prog, skb); 2096 rcu_read_unlock(); 2097 2098 return res; 2099 } 2100 2101 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2102 size_t *len, int vnet_hdr_sz) 2103 { 2104 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2105 2106 if (*len < vnet_hdr_sz) 2107 return -EINVAL; 2108 *len -= vnet_hdr_sz; 2109 2110 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2111 return -EINVAL; 2112 2113 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2114 } 2115 2116 /* 2117 * This function makes lazy skb cloning in hope that most of packets 2118 * are discarded by BPF. 2119 * 2120 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2121 * and skb->cb are mangled. It works because (and until) packets 2122 * falling here are owned by current CPU. Output packets are cloned 2123 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2124 * sequentially, so that if we return skb to original state on exit, 2125 * we will not harm anyone. 2126 */ 2127 2128 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2129 struct packet_type *pt, struct net_device *orig_dev) 2130 { 2131 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2132 struct sock *sk = NULL; 2133 struct sockaddr_ll *sll; 2134 struct packet_sock *po; 2135 u8 *skb_head = skb->data; 2136 int skb_len = skb->len; 2137 unsigned int snaplen, res; 2138 2139 if (skb->pkt_type == PACKET_LOOPBACK) 2140 goto drop; 2141 2142 sk = pt->af_packet_priv; 2143 po = pkt_sk(sk); 2144 2145 if (!net_eq(dev_net(dev), sock_net(sk))) 2146 goto drop; 2147 2148 skb->dev = dev; 2149 2150 if (dev_has_header(dev)) { 2151 /* The device has an explicit notion of ll header, 2152 * exported to higher levels. 2153 * 2154 * Otherwise, the device hides details of its frame 2155 * structure, so that corresponding packet head is 2156 * never delivered to user. 2157 */ 2158 if (sk->sk_type != SOCK_DGRAM) 2159 skb_push(skb, skb->data - skb_mac_header(skb)); 2160 else if (skb->pkt_type == PACKET_OUTGOING) { 2161 /* Special case: outgoing packets have ll header at head */ 2162 skb_pull(skb, skb_network_offset(skb)); 2163 } 2164 } 2165 2166 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2167 2168 res = run_filter(skb, sk, snaplen); 2169 if (!res) 2170 goto drop_n_restore; 2171 if (snaplen > res) 2172 snaplen = res; 2173 2174 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2175 goto drop_n_acct; 2176 2177 if (skb_shared(skb)) { 2178 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2179 if (nskb == NULL) 2180 goto drop_n_acct; 2181 2182 if (skb_head != skb->data) { 2183 skb->data = skb_head; 2184 skb->len = skb_len; 2185 } 2186 consume_skb(skb); 2187 skb = nskb; 2188 } 2189 2190 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2191 2192 sll = &PACKET_SKB_CB(skb)->sa.ll; 2193 sll->sll_hatype = dev->type; 2194 sll->sll_pkttype = skb->pkt_type; 2195 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2196 sll->sll_ifindex = orig_dev->ifindex; 2197 else 2198 sll->sll_ifindex = dev->ifindex; 2199 2200 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2201 2202 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2203 * Use their space for storing the original skb length. 2204 */ 2205 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2206 2207 if (pskb_trim(skb, snaplen)) 2208 goto drop_n_acct; 2209 2210 skb_set_owner_r(skb, sk); 2211 skb->dev = NULL; 2212 skb_dst_drop(skb); 2213 2214 /* drop conntrack reference */ 2215 nf_reset_ct(skb); 2216 2217 spin_lock(&sk->sk_receive_queue.lock); 2218 po->stats.stats1.tp_packets++; 2219 sock_skb_set_dropcount(sk, skb); 2220 skb_clear_delivery_time(skb); 2221 __skb_queue_tail(&sk->sk_receive_queue, skb); 2222 spin_unlock(&sk->sk_receive_queue.lock); 2223 sk->sk_data_ready(sk); 2224 return 0; 2225 2226 drop_n_acct: 2227 atomic_inc(&po->tp_drops); 2228 sk_drops_inc(sk); 2229 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2230 2231 drop_n_restore: 2232 if (skb_head != skb->data && skb_shared(skb)) { 2233 skb->data = skb_head; 2234 skb->len = skb_len; 2235 } 2236 drop: 2237 sk_skb_reason_drop(sk, skb, drop_reason); 2238 return 0; 2239 } 2240 2241 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2242 struct packet_type *pt, struct net_device *orig_dev) 2243 { 2244 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2245 struct sock *sk = NULL; 2246 struct packet_sock *po; 2247 struct sockaddr_ll *sll; 2248 union tpacket_uhdr h; 2249 u8 *skb_head = skb->data; 2250 int skb_len = skb->len; 2251 unsigned int snaplen, res; 2252 unsigned long status = TP_STATUS_USER; 2253 unsigned short macoff, hdrlen; 2254 unsigned int netoff; 2255 struct sk_buff *copy_skb = NULL; 2256 struct timespec64 ts; 2257 __u32 ts_status; 2258 unsigned int slot_id = 0; 2259 int vnet_hdr_sz = 0; 2260 2261 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2262 * We may add members to them until current aligned size without forcing 2263 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2264 */ 2265 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2266 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2267 2268 if (skb->pkt_type == PACKET_LOOPBACK) 2269 goto drop; 2270 2271 sk = pt->af_packet_priv; 2272 po = pkt_sk(sk); 2273 2274 if (!net_eq(dev_net(dev), sock_net(sk))) 2275 goto drop; 2276 2277 if (dev_has_header(dev)) { 2278 if (sk->sk_type != SOCK_DGRAM) 2279 skb_push(skb, skb->data - skb_mac_header(skb)); 2280 else if (skb->pkt_type == PACKET_OUTGOING) { 2281 /* Special case: outgoing packets have ll header at head */ 2282 skb_pull(skb, skb_network_offset(skb)); 2283 } 2284 } 2285 2286 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2287 2288 res = run_filter(skb, sk, snaplen); 2289 if (!res) 2290 goto drop_n_restore; 2291 2292 /* If we are flooded, just give up */ 2293 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2294 atomic_inc(&po->tp_drops); 2295 goto drop_n_restore; 2296 } 2297 2298 if (skb->ip_summed == CHECKSUM_PARTIAL) 2299 status |= TP_STATUS_CSUMNOTREADY; 2300 else if (skb->pkt_type != PACKET_OUTGOING && 2301 skb_csum_unnecessary(skb)) 2302 status |= TP_STATUS_CSUM_VALID; 2303 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2304 status |= TP_STATUS_GSO_TCP; 2305 2306 if (snaplen > res) 2307 snaplen = res; 2308 2309 if (sk->sk_type == SOCK_DGRAM) { 2310 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2311 po->tp_reserve; 2312 } else { 2313 unsigned int maclen = skb_network_offset(skb); 2314 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2315 (maclen < 16 ? 16 : maclen)) + 2316 po->tp_reserve; 2317 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2318 if (vnet_hdr_sz) 2319 netoff += vnet_hdr_sz; 2320 macoff = netoff - maclen; 2321 } 2322 if (netoff > USHRT_MAX) { 2323 atomic_inc(&po->tp_drops); 2324 goto drop_n_restore; 2325 } 2326 if (po->tp_version <= TPACKET_V2) { 2327 if (macoff + snaplen > po->rx_ring.frame_size) { 2328 if (READ_ONCE(po->copy_thresh) && 2329 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2330 if (skb_shared(skb)) { 2331 copy_skb = skb_clone(skb, GFP_ATOMIC); 2332 } else { 2333 copy_skb = skb_get(skb); 2334 skb_head = skb->data; 2335 } 2336 if (copy_skb) { 2337 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2338 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2339 skb_set_owner_r(copy_skb, sk); 2340 } 2341 } 2342 snaplen = po->rx_ring.frame_size - macoff; 2343 if ((int)snaplen < 0) { 2344 snaplen = 0; 2345 vnet_hdr_sz = 0; 2346 } 2347 } 2348 } else if (unlikely(macoff + snaplen > 2349 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2350 u32 nval; 2351 2352 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2353 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2354 snaplen, nval, macoff); 2355 snaplen = nval; 2356 if (unlikely((int)snaplen < 0)) { 2357 snaplen = 0; 2358 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2359 vnet_hdr_sz = 0; 2360 } 2361 } 2362 spin_lock(&sk->sk_receive_queue.lock); 2363 h.raw = packet_current_rx_frame(po, skb, 2364 TP_STATUS_KERNEL, (macoff+snaplen)); 2365 if (!h.raw) 2366 goto drop_n_account; 2367 2368 if (po->tp_version <= TPACKET_V2) { 2369 slot_id = po->rx_ring.head; 2370 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2371 goto drop_n_account; 2372 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2373 } 2374 2375 if (vnet_hdr_sz && 2376 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2377 sizeof(struct virtio_net_hdr), 2378 vio_le(), true, 0)) { 2379 if (po->tp_version == TPACKET_V3) 2380 prb_clear_blk_fill_status(&po->rx_ring); 2381 goto drop_n_account; 2382 } 2383 2384 if (po->tp_version <= TPACKET_V2) { 2385 packet_increment_rx_head(po, &po->rx_ring); 2386 /* 2387 * LOSING will be reported till you read the stats, 2388 * because it's COR - Clear On Read. 2389 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2390 * at packet level. 2391 */ 2392 if (atomic_read(&po->tp_drops)) 2393 status |= TP_STATUS_LOSING; 2394 } 2395 2396 po->stats.stats1.tp_packets++; 2397 if (copy_skb) { 2398 status |= TP_STATUS_COPY; 2399 skb_clear_delivery_time(copy_skb); 2400 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2401 } 2402 spin_unlock(&sk->sk_receive_queue.lock); 2403 2404 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2405 2406 /* Always timestamp; prefer an existing software timestamp taken 2407 * closer to the time of capture. 2408 */ 2409 ts_status = tpacket_get_timestamp(skb, &ts, 2410 READ_ONCE(po->tp_tstamp) | 2411 SOF_TIMESTAMPING_SOFTWARE); 2412 if (!ts_status) 2413 ktime_get_real_ts64(&ts); 2414 2415 status |= ts_status; 2416 2417 switch (po->tp_version) { 2418 case TPACKET_V1: 2419 h.h1->tp_len = skb->len; 2420 h.h1->tp_snaplen = snaplen; 2421 h.h1->tp_mac = macoff; 2422 h.h1->tp_net = netoff; 2423 h.h1->tp_sec = ts.tv_sec; 2424 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2425 hdrlen = sizeof(*h.h1); 2426 break; 2427 case TPACKET_V2: 2428 h.h2->tp_len = skb->len; 2429 h.h2->tp_snaplen = snaplen; 2430 h.h2->tp_mac = macoff; 2431 h.h2->tp_net = netoff; 2432 h.h2->tp_sec = ts.tv_sec; 2433 h.h2->tp_nsec = ts.tv_nsec; 2434 if (skb_vlan_tag_present(skb)) { 2435 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2436 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2437 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2438 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2439 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2440 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2441 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2442 } else { 2443 h.h2->tp_vlan_tci = 0; 2444 h.h2->tp_vlan_tpid = 0; 2445 } 2446 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2447 hdrlen = sizeof(*h.h2); 2448 break; 2449 case TPACKET_V3: 2450 /* tp_nxt_offset,vlan are already populated above. 2451 * So DONT clear those fields here 2452 */ 2453 h.h3->tp_status |= status; 2454 h.h3->tp_len = skb->len; 2455 h.h3->tp_snaplen = snaplen; 2456 h.h3->tp_mac = macoff; 2457 h.h3->tp_net = netoff; 2458 h.h3->tp_sec = ts.tv_sec; 2459 h.h3->tp_nsec = ts.tv_nsec; 2460 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2461 hdrlen = sizeof(*h.h3); 2462 break; 2463 default: 2464 BUG(); 2465 } 2466 2467 sll = h.raw + TPACKET_ALIGN(hdrlen); 2468 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2469 sll->sll_family = AF_PACKET; 2470 sll->sll_hatype = dev->type; 2471 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2472 vlan_get_protocol_dgram(skb) : skb->protocol; 2473 sll->sll_pkttype = skb->pkt_type; 2474 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2475 sll->sll_ifindex = orig_dev->ifindex; 2476 else 2477 sll->sll_ifindex = dev->ifindex; 2478 2479 smp_mb(); 2480 2481 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2482 if (po->tp_version <= TPACKET_V2) { 2483 u8 *start, *end; 2484 2485 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2486 macoff + snaplen); 2487 2488 for (start = h.raw; start < end; start += PAGE_SIZE) 2489 flush_dcache_page(pgv_to_page(start)); 2490 } 2491 smp_wmb(); 2492 #endif 2493 2494 if (po->tp_version <= TPACKET_V2) { 2495 spin_lock(&sk->sk_receive_queue.lock); 2496 __packet_set_status(po, h.raw, status); 2497 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2498 spin_unlock(&sk->sk_receive_queue.lock); 2499 sk->sk_data_ready(sk); 2500 } else if (po->tp_version == TPACKET_V3) { 2501 prb_clear_blk_fill_status(&po->rx_ring); 2502 } 2503 2504 drop_n_restore: 2505 if (skb_head != skb->data && skb_shared(skb)) { 2506 skb->data = skb_head; 2507 skb->len = skb_len; 2508 } 2509 drop: 2510 sk_skb_reason_drop(sk, skb, drop_reason); 2511 return 0; 2512 2513 drop_n_account: 2514 spin_unlock(&sk->sk_receive_queue.lock); 2515 atomic_inc(&po->tp_drops); 2516 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2517 2518 sk->sk_data_ready(sk); 2519 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2520 goto drop_n_restore; 2521 } 2522 2523 static void tpacket_destruct_skb(struct sk_buff *skb) 2524 { 2525 struct packet_sock *po = pkt_sk(skb->sk); 2526 2527 if (likely(po->tx_ring.pg_vec)) { 2528 void *ph; 2529 __u32 ts; 2530 2531 ph = skb_zcopy_get_nouarg(skb); 2532 packet_dec_pending(&po->tx_ring); 2533 2534 ts = __packet_set_timestamp(po, ph, skb); 2535 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2536 2537 complete(&po->skb_completion); 2538 } 2539 2540 sock_wfree(skb); 2541 } 2542 2543 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2544 { 2545 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2546 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2547 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2548 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2549 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2550 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2551 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2552 2553 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2554 return -EINVAL; 2555 2556 return 0; 2557 } 2558 2559 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2560 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2561 { 2562 int ret; 2563 2564 if (*len < vnet_hdr_sz) 2565 return -EINVAL; 2566 *len -= vnet_hdr_sz; 2567 2568 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2569 return -EFAULT; 2570 2571 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2572 if (ret) 2573 return ret; 2574 2575 /* move iter to point to the start of mac header */ 2576 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2577 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2578 2579 return 0; 2580 } 2581 2582 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2583 void *frame, struct net_device *dev, void *data, int tp_len, 2584 __be16 proto, unsigned char *addr, int hlen, int copylen, 2585 const struct sockcm_cookie *sockc) 2586 { 2587 union tpacket_uhdr ph; 2588 int to_write, offset, len, nr_frags, len_max; 2589 struct socket *sock = po->sk.sk_socket; 2590 struct page *page; 2591 int err; 2592 2593 ph.raw = frame; 2594 2595 skb->protocol = proto; 2596 skb->dev = dev; 2597 skb->priority = sockc->priority; 2598 skb->mark = sockc->mark; 2599 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2600 skb_setup_tx_timestamp(skb, sockc); 2601 skb_zcopy_set_nouarg(skb, ph.raw); 2602 2603 skb_reserve(skb, hlen); 2604 skb_reset_network_header(skb); 2605 2606 to_write = tp_len; 2607 2608 if (sock->type == SOCK_DGRAM) { 2609 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2610 NULL, tp_len); 2611 if (unlikely(err < 0)) 2612 return -EINVAL; 2613 } else if (copylen) { 2614 int hdrlen = min_t(int, copylen, tp_len); 2615 2616 skb_push(skb, dev->hard_header_len); 2617 skb_put(skb, copylen - dev->hard_header_len); 2618 err = skb_store_bits(skb, 0, data, hdrlen); 2619 if (unlikely(err)) 2620 return err; 2621 if (!dev_validate_header(dev, skb->data, hdrlen)) 2622 return -EINVAL; 2623 2624 data += hdrlen; 2625 to_write -= hdrlen; 2626 } 2627 2628 offset = offset_in_page(data); 2629 len_max = PAGE_SIZE - offset; 2630 len = ((to_write > len_max) ? len_max : to_write); 2631 2632 skb->data_len = to_write; 2633 skb->len += to_write; 2634 skb->truesize += to_write; 2635 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2636 2637 while (likely(to_write)) { 2638 nr_frags = skb_shinfo(skb)->nr_frags; 2639 2640 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2641 pr_err("Packet exceed the number of skb frags(%u)\n", 2642 (unsigned int)MAX_SKB_FRAGS); 2643 return -EFAULT; 2644 } 2645 2646 page = pgv_to_page(data); 2647 data += len; 2648 flush_dcache_page(page); 2649 get_page(page); 2650 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2651 to_write -= len; 2652 offset = 0; 2653 len_max = PAGE_SIZE; 2654 len = ((to_write > len_max) ? len_max : to_write); 2655 } 2656 2657 packet_parse_headers(skb, sock); 2658 2659 return tp_len; 2660 } 2661 2662 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2663 int size_max, void **data) 2664 { 2665 union tpacket_uhdr ph; 2666 int tp_len, off; 2667 2668 ph.raw = frame; 2669 2670 switch (po->tp_version) { 2671 case TPACKET_V3: 2672 if (ph.h3->tp_next_offset != 0) { 2673 pr_warn_once("variable sized slot not supported"); 2674 return -EINVAL; 2675 } 2676 tp_len = ph.h3->tp_len; 2677 break; 2678 case TPACKET_V2: 2679 tp_len = ph.h2->tp_len; 2680 break; 2681 default: 2682 tp_len = ph.h1->tp_len; 2683 break; 2684 } 2685 if (unlikely(tp_len > size_max)) { 2686 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2687 return -EMSGSIZE; 2688 } 2689 2690 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2691 int off_min, off_max; 2692 2693 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2694 off_max = po->tx_ring.frame_size - tp_len; 2695 if (po->sk.sk_type == SOCK_DGRAM) { 2696 switch (po->tp_version) { 2697 case TPACKET_V3: 2698 off = ph.h3->tp_net; 2699 break; 2700 case TPACKET_V2: 2701 off = ph.h2->tp_net; 2702 break; 2703 default: 2704 off = ph.h1->tp_net; 2705 break; 2706 } 2707 } else { 2708 switch (po->tp_version) { 2709 case TPACKET_V3: 2710 off = ph.h3->tp_mac; 2711 break; 2712 case TPACKET_V2: 2713 off = ph.h2->tp_mac; 2714 break; 2715 default: 2716 off = ph.h1->tp_mac; 2717 break; 2718 } 2719 } 2720 if (unlikely((off < off_min) || (off_max < off))) 2721 return -EINVAL; 2722 } else { 2723 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2724 } 2725 2726 *data = frame + off; 2727 return tp_len; 2728 } 2729 2730 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2731 { 2732 struct sk_buff *skb = NULL; 2733 struct net_device *dev; 2734 struct virtio_net_hdr vnet_hdr; 2735 bool has_vnet_hdr = false; 2736 struct sockcm_cookie sockc; 2737 __be16 proto; 2738 int err, reserve = 0; 2739 void *ph; 2740 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2741 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2742 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2743 unsigned char *addr = NULL; 2744 int tp_len, size_max; 2745 void *data; 2746 int len_sum = 0; 2747 int status = TP_STATUS_AVAILABLE; 2748 int hlen, tlen, copylen = 0; 2749 long timeo; 2750 2751 mutex_lock(&po->pg_vec_lock); 2752 2753 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2754 * we need to confirm it under protection of pg_vec_lock. 2755 */ 2756 if (unlikely(!po->tx_ring.pg_vec)) { 2757 err = -EBUSY; 2758 goto out; 2759 } 2760 if (likely(saddr == NULL)) { 2761 dev = packet_cached_dev_get(po); 2762 proto = READ_ONCE(po->num); 2763 } else { 2764 err = -EINVAL; 2765 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2766 goto out; 2767 if (msg->msg_namelen < (saddr->sll_halen 2768 + offsetof(struct sockaddr_ll, 2769 sll_addr))) 2770 goto out; 2771 proto = saddr->sll_protocol; 2772 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2773 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2774 if (dev && msg->msg_namelen < dev->addr_len + 2775 offsetof(struct sockaddr_ll, sll_addr)) 2776 goto out_put; 2777 addr = saddr->sll_addr; 2778 } 2779 } 2780 2781 err = -ENXIO; 2782 if (unlikely(dev == NULL)) 2783 goto out; 2784 err = -ENETDOWN; 2785 if (unlikely(!(dev->flags & IFF_UP))) 2786 goto out_put; 2787 2788 sockcm_init(&sockc, &po->sk); 2789 if (msg->msg_controllen) { 2790 err = sock_cmsg_send(&po->sk, msg, &sockc); 2791 if (unlikely(err)) 2792 goto out_put; 2793 } 2794 2795 if (po->sk.sk_socket->type == SOCK_RAW) 2796 reserve = dev->hard_header_len; 2797 size_max = po->tx_ring.frame_size 2798 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2799 2800 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2801 size_max = dev->mtu + reserve + VLAN_HLEN; 2802 2803 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2804 reinit_completion(&po->skb_completion); 2805 2806 do { 2807 ph = packet_current_frame(po, &po->tx_ring, 2808 TP_STATUS_SEND_REQUEST); 2809 if (unlikely(ph == NULL)) { 2810 /* Note: packet_read_pending() might be slow if we 2811 * have to call it as it's per_cpu variable, but in 2812 * fast-path we don't have to call it, only when ph 2813 * is NULL, we need to check the pending_refcnt. 2814 */ 2815 if (need_wait && packet_read_pending(&po->tx_ring)) { 2816 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2817 if (timeo <= 0) { 2818 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2819 goto out_put; 2820 } 2821 /* check for additional frames */ 2822 continue; 2823 } else 2824 break; 2825 } 2826 2827 skb = NULL; 2828 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2829 if (tp_len < 0) 2830 goto tpacket_error; 2831 2832 status = TP_STATUS_SEND_REQUEST; 2833 hlen = LL_RESERVED_SPACE(dev); 2834 tlen = dev->needed_tailroom; 2835 if (vnet_hdr_sz) { 2836 data += vnet_hdr_sz; 2837 tp_len -= vnet_hdr_sz; 2838 if (tp_len < 0) { 2839 tp_len = -EINVAL; 2840 goto tpacket_error; 2841 } 2842 memcpy(&vnet_hdr, data - vnet_hdr_sz, sizeof(vnet_hdr)); 2843 if (__packet_snd_vnet_parse(&vnet_hdr, tp_len)) { 2844 tp_len = -EINVAL; 2845 goto tpacket_error; 2846 } 2847 copylen = __virtio16_to_cpu(vio_le(), 2848 vnet_hdr.hdr_len); 2849 has_vnet_hdr = true; 2850 } 2851 copylen = max_t(int, copylen, dev->hard_header_len); 2852 skb = sock_alloc_send_skb(&po->sk, 2853 hlen + tlen + sizeof(struct sockaddr_ll) + 2854 (copylen - dev->hard_header_len), 2855 !need_wait, &err); 2856 2857 if (unlikely(skb == NULL)) { 2858 /* we assume the socket was initially writeable ... */ 2859 if (likely(len_sum > 0)) 2860 err = len_sum; 2861 goto out_status; 2862 } 2863 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2864 addr, hlen, copylen, &sockc); 2865 if (likely(tp_len >= 0) && 2866 tp_len > dev->mtu + reserve && 2867 !vnet_hdr_sz && 2868 !packet_extra_vlan_len_allowed(dev, skb)) 2869 tp_len = -EMSGSIZE; 2870 2871 if (unlikely(tp_len < 0)) { 2872 tpacket_error: 2873 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2874 __packet_set_status(po, ph, 2875 TP_STATUS_AVAILABLE); 2876 packet_increment_head(&po->tx_ring); 2877 kfree_skb(skb); 2878 continue; 2879 } else { 2880 status = TP_STATUS_WRONG_FORMAT; 2881 err = tp_len; 2882 goto out_status; 2883 } 2884 } 2885 2886 if (has_vnet_hdr) { 2887 if (virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le())) { 2888 tp_len = -EINVAL; 2889 goto tpacket_error; 2890 } 2891 virtio_net_hdr_set_proto(skb, &vnet_hdr); 2892 } 2893 2894 skb->destructor = tpacket_destruct_skb; 2895 __packet_set_status(po, ph, TP_STATUS_SENDING); 2896 packet_inc_pending(&po->tx_ring); 2897 2898 status = TP_STATUS_SEND_REQUEST; 2899 err = packet_xmit(po, skb); 2900 if (unlikely(err != 0)) { 2901 if (err > 0) 2902 err = net_xmit_errno(err); 2903 if (err && __packet_get_status(po, ph) == 2904 TP_STATUS_AVAILABLE) { 2905 /* skb was destructed already */ 2906 skb = NULL; 2907 goto out_status; 2908 } 2909 /* 2910 * skb was dropped but not destructed yet; 2911 * let's treat it like congestion or err < 0 2912 */ 2913 err = 0; 2914 } 2915 packet_increment_head(&po->tx_ring); 2916 len_sum += tp_len; 2917 } while (1); 2918 2919 err = len_sum; 2920 goto out_put; 2921 2922 out_status: 2923 __packet_set_status(po, ph, status); 2924 kfree_skb(skb); 2925 out_put: 2926 dev_put(dev); 2927 out: 2928 mutex_unlock(&po->pg_vec_lock); 2929 return err; 2930 } 2931 2932 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2933 size_t reserve, size_t len, 2934 size_t linear, int noblock, 2935 int *err) 2936 { 2937 struct sk_buff *skb; 2938 2939 /* Under a page? Don't bother with paged skb. */ 2940 if (prepad + len < PAGE_SIZE || !linear) 2941 linear = len; 2942 2943 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2944 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2945 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2946 err, PAGE_ALLOC_COSTLY_ORDER); 2947 if (!skb) 2948 return NULL; 2949 2950 skb_reserve(skb, reserve); 2951 skb_put(skb, linear); 2952 skb->data_len = len - linear; 2953 skb->len += len - linear; 2954 2955 return skb; 2956 } 2957 2958 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2959 { 2960 struct sock *sk = sock->sk; 2961 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2962 struct sk_buff *skb; 2963 struct net_device *dev; 2964 __be16 proto; 2965 unsigned char *addr = NULL; 2966 int err, reserve = 0; 2967 struct sockcm_cookie sockc; 2968 struct virtio_net_hdr vnet_hdr = { 0 }; 2969 int offset = 0; 2970 struct packet_sock *po = pkt_sk(sk); 2971 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2972 int hlen, tlen, linear; 2973 int extra_len = 0; 2974 2975 /* 2976 * Get and verify the address. 2977 */ 2978 2979 if (likely(saddr == NULL)) { 2980 dev = packet_cached_dev_get(po); 2981 proto = READ_ONCE(po->num); 2982 } else { 2983 err = -EINVAL; 2984 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2985 goto out; 2986 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2987 goto out; 2988 proto = saddr->sll_protocol; 2989 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2990 if (sock->type == SOCK_DGRAM) { 2991 if (dev && msg->msg_namelen < dev->addr_len + 2992 offsetof(struct sockaddr_ll, sll_addr)) 2993 goto out_unlock; 2994 addr = saddr->sll_addr; 2995 } 2996 } 2997 2998 err = -ENXIO; 2999 if (unlikely(dev == NULL)) 3000 goto out_unlock; 3001 err = -ENETDOWN; 3002 if (unlikely(!(dev->flags & IFF_UP))) 3003 goto out_unlock; 3004 3005 sockcm_init(&sockc, sk); 3006 if (msg->msg_controllen) { 3007 err = sock_cmsg_send(sk, msg, &sockc); 3008 if (unlikely(err)) 3009 goto out_unlock; 3010 } 3011 3012 if (sock->type == SOCK_RAW) 3013 reserve = dev->hard_header_len; 3014 if (vnet_hdr_sz) { 3015 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3016 if (err) 3017 goto out_unlock; 3018 } 3019 3020 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3021 if (!netif_supports_nofcs(dev)) { 3022 err = -EPROTONOSUPPORT; 3023 goto out_unlock; 3024 } 3025 extra_len = 4; /* We're doing our own CRC */ 3026 } 3027 3028 err = -EMSGSIZE; 3029 if (!vnet_hdr.gso_type && 3030 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3031 goto out_unlock; 3032 3033 err = -ENOBUFS; 3034 hlen = LL_RESERVED_SPACE(dev); 3035 tlen = dev->needed_tailroom; 3036 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3037 linear = max(linear, min_t(int, len, dev->hard_header_len)); 3038 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3039 msg->msg_flags & MSG_DONTWAIT, &err); 3040 if (skb == NULL) 3041 goto out_unlock; 3042 3043 skb_reset_network_header(skb); 3044 3045 err = -EINVAL; 3046 if (sock->type == SOCK_DGRAM) { 3047 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3048 if (unlikely(offset < 0)) 3049 goto out_free; 3050 } else if (reserve) { 3051 skb_reserve(skb, -reserve); 3052 if (len < reserve + sizeof(struct ipv6hdr) && 3053 dev->min_header_len != dev->hard_header_len) 3054 skb_reset_network_header(skb); 3055 } 3056 3057 /* Returns -EFAULT on error */ 3058 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3059 if (err) 3060 goto out_free; 3061 3062 if ((sock->type == SOCK_RAW && 3063 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3064 err = -EINVAL; 3065 goto out_free; 3066 } 3067 3068 skb_setup_tx_timestamp(skb, &sockc); 3069 3070 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3071 !packet_extra_vlan_len_allowed(dev, skb)) { 3072 err = -EMSGSIZE; 3073 goto out_free; 3074 } 3075 3076 skb->protocol = proto; 3077 skb->dev = dev; 3078 skb->priority = sockc.priority; 3079 skb->mark = sockc.mark; 3080 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3081 3082 if (unlikely(extra_len == 4)) 3083 skb->no_fcs = 1; 3084 3085 packet_parse_headers(skb, sock); 3086 3087 if (vnet_hdr_sz) { 3088 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3089 if (err) 3090 goto out_free; 3091 len += vnet_hdr_sz; 3092 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3093 } 3094 3095 err = packet_xmit(po, skb); 3096 3097 if (unlikely(err != 0)) { 3098 if (err > 0) 3099 err = net_xmit_errno(err); 3100 if (err) 3101 goto out_unlock; 3102 } 3103 3104 dev_put(dev); 3105 3106 return len; 3107 3108 out_free: 3109 kfree_skb(skb); 3110 out_unlock: 3111 dev_put(dev); 3112 out: 3113 return err; 3114 } 3115 3116 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3117 { 3118 struct sock *sk = sock->sk; 3119 struct packet_sock *po = pkt_sk(sk); 3120 3121 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3122 * tpacket_snd() will redo the check safely. 3123 */ 3124 if (data_race(po->tx_ring.pg_vec)) 3125 return tpacket_snd(po, msg); 3126 3127 return packet_snd(sock, msg, len); 3128 } 3129 3130 /* 3131 * Close a PACKET socket. This is fairly simple. We immediately go 3132 * to 'closed' state and remove our protocol entry in the device list. 3133 */ 3134 3135 static int packet_release(struct socket *sock) 3136 { 3137 struct sock *sk = sock->sk; 3138 struct packet_sock *po; 3139 struct packet_fanout *f; 3140 struct net *net; 3141 union tpacket_req_u req_u; 3142 3143 if (!sk) 3144 return 0; 3145 3146 net = sock_net(sk); 3147 po = pkt_sk(sk); 3148 3149 mutex_lock(&net->packet.sklist_lock); 3150 sk_del_node_init_rcu(sk); 3151 mutex_unlock(&net->packet.sklist_lock); 3152 3153 sock_prot_inuse_add(net, sk->sk_prot, -1); 3154 3155 spin_lock(&po->bind_lock); 3156 unregister_prot_hook(sk, false); 3157 WRITE_ONCE(po->num, 0); 3158 packet_cached_dev_reset(po); 3159 3160 if (po->prot_hook.dev) { 3161 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3162 po->prot_hook.dev = NULL; 3163 } 3164 spin_unlock(&po->bind_lock); 3165 3166 packet_flush_mclist(sk); 3167 3168 lock_sock(sk); 3169 if (po->rx_ring.pg_vec) { 3170 memset(&req_u, 0, sizeof(req_u)); 3171 packet_set_ring(sk, &req_u, 1, 0); 3172 } 3173 3174 if (po->tx_ring.pg_vec) { 3175 memset(&req_u, 0, sizeof(req_u)); 3176 packet_set_ring(sk, &req_u, 1, 1); 3177 } 3178 release_sock(sk); 3179 3180 f = fanout_release(sk); 3181 3182 synchronize_net(); 3183 3184 kfree(po->rollover); 3185 if (f) { 3186 fanout_release_data(f); 3187 kvfree(f); 3188 } 3189 /* 3190 * Now the socket is dead. No more input will appear. 3191 */ 3192 sock_orphan(sk); 3193 sock->sk = NULL; 3194 3195 /* Purge queues */ 3196 3197 skb_queue_purge(&sk->sk_receive_queue); 3198 packet_free_pending(po); 3199 3200 sock_put(sk); 3201 return 0; 3202 } 3203 3204 /* 3205 * Attach a packet hook. 3206 */ 3207 3208 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3209 __be16 proto) 3210 { 3211 struct packet_sock *po = pkt_sk(sk); 3212 struct net_device *dev = NULL; 3213 bool unlisted = false; 3214 bool need_rehook; 3215 int ret = 0; 3216 3217 lock_sock(sk); 3218 spin_lock(&po->bind_lock); 3219 if (!proto) 3220 proto = po->num; 3221 3222 rcu_read_lock(); 3223 3224 if (po->fanout) { 3225 ret = -EINVAL; 3226 goto out_unlock; 3227 } 3228 3229 if (name) { 3230 dev = dev_get_by_name_rcu(sock_net(sk), name); 3231 if (!dev) { 3232 ret = -ENODEV; 3233 goto out_unlock; 3234 } 3235 } else if (ifindex) { 3236 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3237 if (!dev) { 3238 ret = -ENODEV; 3239 goto out_unlock; 3240 } 3241 } 3242 3243 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3244 3245 if (need_rehook) { 3246 dev_hold(dev); 3247 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3248 rcu_read_unlock(); 3249 /* prevents packet_notifier() from calling 3250 * register_prot_hook() 3251 */ 3252 WRITE_ONCE(po->num, 0); 3253 __unregister_prot_hook(sk, true); 3254 rcu_read_lock(); 3255 if (dev) 3256 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3257 dev->ifindex); 3258 } 3259 3260 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3261 WRITE_ONCE(po->num, proto); 3262 po->prot_hook.type = proto; 3263 3264 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3265 3266 if (unlikely(unlisted)) { 3267 po->prot_hook.dev = NULL; 3268 WRITE_ONCE(po->ifindex, -1); 3269 packet_cached_dev_reset(po); 3270 } else { 3271 netdev_hold(dev, &po->prot_hook.dev_tracker, 3272 GFP_ATOMIC); 3273 po->prot_hook.dev = dev; 3274 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3275 packet_cached_dev_assign(po, dev); 3276 } 3277 dev_put(dev); 3278 } 3279 3280 if (proto == 0 || !need_rehook) 3281 goto out_unlock; 3282 3283 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3284 register_prot_hook(sk); 3285 } else { 3286 sk->sk_err = ENETDOWN; 3287 if (!sock_flag(sk, SOCK_DEAD)) 3288 sk_error_report(sk); 3289 } 3290 3291 out_unlock: 3292 rcu_read_unlock(); 3293 spin_unlock(&po->bind_lock); 3294 release_sock(sk); 3295 return ret; 3296 } 3297 3298 /* 3299 * Bind a packet socket to a device 3300 */ 3301 3302 static int packet_bind_spkt(struct socket *sock, struct sockaddr_unsized *uaddr, 3303 int addr_len) 3304 { 3305 struct sock *sk = sock->sk; 3306 struct sockaddr *sa = (struct sockaddr *)uaddr; 3307 char name[sizeof(sa->sa_data) + 1]; 3308 3309 /* 3310 * Check legality 3311 */ 3312 3313 if (addr_len != sizeof(struct sockaddr)) 3314 return -EINVAL; 3315 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3316 * zero-terminated. 3317 */ 3318 memcpy(name, sa->sa_data, sizeof(sa->sa_data)); 3319 name[sizeof(sa->sa_data)] = 0; 3320 3321 return packet_do_bind(sk, name, 0, 0); 3322 } 3323 3324 static int packet_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len) 3325 { 3326 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3327 struct sock *sk = sock->sk; 3328 3329 /* 3330 * Check legality 3331 */ 3332 3333 if (addr_len < sizeof(struct sockaddr_ll)) 3334 return -EINVAL; 3335 if (sll->sll_family != AF_PACKET) 3336 return -EINVAL; 3337 3338 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3339 } 3340 3341 static struct proto packet_proto = { 3342 .name = "PACKET", 3343 .owner = THIS_MODULE, 3344 .obj_size = sizeof(struct packet_sock), 3345 }; 3346 3347 /* 3348 * Create a packet of type SOCK_PACKET. 3349 */ 3350 3351 static int packet_create(struct net *net, struct socket *sock, int protocol, 3352 int kern) 3353 { 3354 struct sock *sk; 3355 struct packet_sock *po; 3356 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3357 int err; 3358 3359 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3360 return -EPERM; 3361 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3362 sock->type != SOCK_PACKET) 3363 return -ESOCKTNOSUPPORT; 3364 3365 sock->state = SS_UNCONNECTED; 3366 3367 err = -ENOBUFS; 3368 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3369 if (sk == NULL) 3370 goto out; 3371 3372 sock->ops = &packet_ops; 3373 if (sock->type == SOCK_PACKET) 3374 sock->ops = &packet_ops_spkt; 3375 3376 po = pkt_sk(sk); 3377 err = packet_alloc_pending(po); 3378 if (err) 3379 goto out_sk_free; 3380 3381 sock_init_data(sock, sk); 3382 3383 init_completion(&po->skb_completion); 3384 sk->sk_family = PF_PACKET; 3385 po->num = proto; 3386 3387 packet_cached_dev_reset(po); 3388 3389 sk->sk_destruct = packet_sock_destruct; 3390 3391 /* 3392 * Attach a protocol block 3393 */ 3394 3395 spin_lock_init(&po->bind_lock); 3396 mutex_init(&po->pg_vec_lock); 3397 po->rollover = NULL; 3398 po->prot_hook.func = packet_rcv; 3399 3400 if (sock->type == SOCK_PACKET) 3401 po->prot_hook.func = packet_rcv_spkt; 3402 3403 po->prot_hook.af_packet_priv = sk; 3404 po->prot_hook.af_packet_net = sock_net(sk); 3405 3406 if (proto) { 3407 po->prot_hook.type = proto; 3408 __register_prot_hook(sk); 3409 } 3410 3411 mutex_lock(&net->packet.sklist_lock); 3412 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3413 mutex_unlock(&net->packet.sklist_lock); 3414 3415 sock_prot_inuse_add(net, &packet_proto, 1); 3416 3417 return 0; 3418 out_sk_free: 3419 sk_free(sk); 3420 out: 3421 return err; 3422 } 3423 3424 /* 3425 * Pull a packet from our receive queue and hand it to the user. 3426 * If necessary we block. 3427 */ 3428 3429 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3430 int flags) 3431 { 3432 struct sock *sk = sock->sk; 3433 struct sk_buff *skb; 3434 int copied, err; 3435 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3436 unsigned int origlen = 0; 3437 3438 err = -EINVAL; 3439 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3440 goto out; 3441 3442 #if 0 3443 /* What error should we return now? EUNATTACH? */ 3444 if (pkt_sk(sk)->ifindex < 0) 3445 return -ENODEV; 3446 #endif 3447 3448 if (flags & MSG_ERRQUEUE) { 3449 err = sock_recv_errqueue(sk, msg, len, 3450 SOL_PACKET, PACKET_TX_TIMESTAMP); 3451 goto out; 3452 } 3453 3454 /* 3455 * Call the generic datagram receiver. This handles all sorts 3456 * of horrible races and re-entrancy so we can forget about it 3457 * in the protocol layers. 3458 * 3459 * Now it will return ENETDOWN, if device have just gone down, 3460 * but then it will block. 3461 */ 3462 3463 skb = skb_recv_datagram(sk, flags, &err); 3464 3465 /* 3466 * An error occurred so return it. Because skb_recv_datagram() 3467 * handles the blocking we don't see and worry about blocking 3468 * retries. 3469 */ 3470 3471 if (skb == NULL) 3472 goto out; 3473 3474 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3475 3476 if (vnet_hdr_len) { 3477 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3478 if (err) 3479 goto out_free; 3480 } 3481 3482 /* You lose any data beyond the buffer you gave. If it worries 3483 * a user program they can ask the device for its MTU 3484 * anyway. 3485 */ 3486 copied = skb->len; 3487 if (copied > len) { 3488 copied = len; 3489 msg->msg_flags |= MSG_TRUNC; 3490 } 3491 3492 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3493 if (err) 3494 goto out_free; 3495 3496 if (sock->type != SOCK_PACKET) { 3497 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3498 3499 /* Original length was stored in sockaddr_ll fields */ 3500 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3501 sll->sll_family = AF_PACKET; 3502 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3503 vlan_get_protocol_dgram(skb) : skb->protocol; 3504 } 3505 3506 sock_recv_cmsgs(msg, sk, skb); 3507 3508 if (msg->msg_name) { 3509 const size_t max_len = min(sizeof(skb->cb), 3510 sizeof(struct sockaddr_storage)); 3511 int copy_len; 3512 3513 /* If the address length field is there to be filled 3514 * in, we fill it in now. 3515 */ 3516 if (sock->type == SOCK_PACKET) { 3517 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3518 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3519 copy_len = msg->msg_namelen; 3520 } else { 3521 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3522 3523 msg->msg_namelen = sll->sll_halen + 3524 offsetof(struct sockaddr_ll, sll_addr); 3525 copy_len = msg->msg_namelen; 3526 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3527 memset(msg->msg_name + 3528 offsetof(struct sockaddr_ll, sll_addr), 3529 0, sizeof(sll->sll_addr)); 3530 msg->msg_namelen = sizeof(struct sockaddr_ll); 3531 } 3532 } 3533 if (WARN_ON_ONCE(copy_len > max_len)) { 3534 copy_len = max_len; 3535 msg->msg_namelen = copy_len; 3536 } 3537 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3538 } 3539 3540 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3541 struct tpacket_auxdata aux; 3542 3543 aux.tp_status = TP_STATUS_USER; 3544 if (skb->ip_summed == CHECKSUM_PARTIAL) 3545 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3546 else if (skb->pkt_type != PACKET_OUTGOING && 3547 skb_csum_unnecessary(skb)) 3548 aux.tp_status |= TP_STATUS_CSUM_VALID; 3549 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3550 aux.tp_status |= TP_STATUS_GSO_TCP; 3551 3552 aux.tp_len = origlen; 3553 aux.tp_snaplen = skb->len; 3554 aux.tp_mac = 0; 3555 aux.tp_net = skb_network_offset(skb); 3556 if (skb_vlan_tag_present(skb)) { 3557 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3558 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3559 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3560 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3561 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3562 struct net_device *dev; 3563 3564 rcu_read_lock(); 3565 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3566 if (dev) { 3567 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3568 aux.tp_vlan_tpid = ntohs(skb->protocol); 3569 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3570 } else { 3571 aux.tp_vlan_tci = 0; 3572 aux.tp_vlan_tpid = 0; 3573 } 3574 rcu_read_unlock(); 3575 } else { 3576 aux.tp_vlan_tci = 0; 3577 aux.tp_vlan_tpid = 0; 3578 } 3579 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3580 } 3581 3582 /* 3583 * Free or return the buffer as appropriate. Again this 3584 * hides all the races and re-entrancy issues from us. 3585 */ 3586 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3587 3588 out_free: 3589 skb_free_datagram(sk, skb); 3590 out: 3591 return err; 3592 } 3593 3594 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3595 int peer) 3596 { 3597 struct net_device *dev; 3598 struct sock *sk = sock->sk; 3599 3600 if (peer) 3601 return -EOPNOTSUPP; 3602 3603 uaddr->sa_family = AF_PACKET; 3604 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3605 rcu_read_lock(); 3606 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3607 if (dev) 3608 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3609 rcu_read_unlock(); 3610 3611 return sizeof(*uaddr); 3612 } 3613 3614 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3615 int peer) 3616 { 3617 struct net_device *dev; 3618 struct sock *sk = sock->sk; 3619 struct packet_sock *po = pkt_sk(sk); 3620 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3621 int ifindex; 3622 3623 if (peer) 3624 return -EOPNOTSUPP; 3625 3626 ifindex = READ_ONCE(po->ifindex); 3627 sll->sll_family = AF_PACKET; 3628 sll->sll_ifindex = ifindex; 3629 sll->sll_protocol = READ_ONCE(po->num); 3630 sll->sll_pkttype = 0; 3631 rcu_read_lock(); 3632 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3633 if (dev) { 3634 sll->sll_hatype = dev->type; 3635 sll->sll_halen = dev->addr_len; 3636 3637 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3638 memcpy(((struct sockaddr_storage *)sll)->__data + 3639 offsetof(struct sockaddr_ll, sll_addr) - 3640 offsetofend(struct sockaddr_ll, sll_family), 3641 dev->dev_addr, dev->addr_len); 3642 } else { 3643 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3644 sll->sll_halen = 0; 3645 } 3646 rcu_read_unlock(); 3647 3648 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3649 } 3650 3651 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3652 int what) 3653 { 3654 switch (i->type) { 3655 case PACKET_MR_MULTICAST: 3656 if (i->alen != dev->addr_len) 3657 return -EINVAL; 3658 if (what > 0) 3659 return dev_mc_add(dev, i->addr); 3660 else 3661 return dev_mc_del(dev, i->addr); 3662 break; 3663 case PACKET_MR_PROMISC: 3664 return dev_set_promiscuity(dev, what); 3665 case PACKET_MR_ALLMULTI: 3666 return dev_set_allmulti(dev, what); 3667 case PACKET_MR_UNICAST: 3668 if (i->alen != dev->addr_len) 3669 return -EINVAL; 3670 if (what > 0) 3671 return dev_uc_add(dev, i->addr); 3672 else 3673 return dev_uc_del(dev, i->addr); 3674 break; 3675 default: 3676 break; 3677 } 3678 return 0; 3679 } 3680 3681 static void packet_dev_mclist_delete(struct net_device *dev, 3682 struct packet_mclist **mlp, 3683 struct list_head *list) 3684 { 3685 struct packet_mclist *ml; 3686 3687 while ((ml = *mlp) != NULL) { 3688 if (ml->ifindex == dev->ifindex) { 3689 list_add(&ml->remove_list, list); 3690 *mlp = ml->next; 3691 } else 3692 mlp = &ml->next; 3693 } 3694 } 3695 3696 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3697 { 3698 struct packet_sock *po = pkt_sk(sk); 3699 struct packet_mclist *ml, *i; 3700 struct net_device *dev; 3701 int err; 3702 3703 rtnl_lock(); 3704 3705 err = -ENODEV; 3706 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3707 if (!dev) 3708 goto done; 3709 3710 err = -EINVAL; 3711 if (mreq->mr_alen > dev->addr_len) 3712 goto done; 3713 3714 err = -ENOBUFS; 3715 i = kmalloc_obj(*i); 3716 if (i == NULL) 3717 goto done; 3718 3719 err = 0; 3720 for (ml = po->mclist; ml; ml = ml->next) { 3721 if (ml->ifindex == mreq->mr_ifindex && 3722 ml->type == mreq->mr_type && 3723 ml->alen == mreq->mr_alen && 3724 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3725 ml->count++; 3726 /* Free the new element ... */ 3727 kfree(i); 3728 goto done; 3729 } 3730 } 3731 3732 i->type = mreq->mr_type; 3733 i->ifindex = mreq->mr_ifindex; 3734 i->alen = mreq->mr_alen; 3735 memcpy(i->addr, mreq->mr_address, i->alen); 3736 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3737 i->count = 1; 3738 INIT_LIST_HEAD(&i->remove_list); 3739 i->next = po->mclist; 3740 po->mclist = i; 3741 err = packet_dev_mc(dev, i, 1); 3742 if (err) { 3743 po->mclist = i->next; 3744 kfree(i); 3745 } 3746 3747 done: 3748 rtnl_unlock(); 3749 return err; 3750 } 3751 3752 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3753 { 3754 struct packet_mclist *ml, **mlp; 3755 3756 rtnl_lock(); 3757 3758 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3759 if (ml->ifindex == mreq->mr_ifindex && 3760 ml->type == mreq->mr_type && 3761 ml->alen == mreq->mr_alen && 3762 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3763 if (--ml->count == 0) { 3764 struct net_device *dev; 3765 *mlp = ml->next; 3766 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3767 if (dev) 3768 packet_dev_mc(dev, ml, -1); 3769 kfree(ml); 3770 } 3771 break; 3772 } 3773 } 3774 rtnl_unlock(); 3775 return 0; 3776 } 3777 3778 static void packet_flush_mclist(struct sock *sk) 3779 { 3780 struct packet_sock *po = pkt_sk(sk); 3781 struct packet_mclist *ml; 3782 3783 if (!po->mclist) 3784 return; 3785 3786 rtnl_lock(); 3787 while ((ml = po->mclist) != NULL) { 3788 struct net_device *dev; 3789 3790 po->mclist = ml->next; 3791 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3792 if (dev != NULL) 3793 packet_dev_mc(dev, ml, -1); 3794 kfree(ml); 3795 } 3796 rtnl_unlock(); 3797 } 3798 3799 static int 3800 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3801 unsigned int optlen) 3802 { 3803 struct sock *sk = sock->sk; 3804 struct packet_sock *po = pkt_sk(sk); 3805 int ret; 3806 3807 if (level != SOL_PACKET) 3808 return -ENOPROTOOPT; 3809 3810 switch (optname) { 3811 case PACKET_ADD_MEMBERSHIP: 3812 case PACKET_DROP_MEMBERSHIP: 3813 { 3814 struct packet_mreq_max mreq; 3815 int len = optlen; 3816 memset(&mreq, 0, sizeof(mreq)); 3817 if (len < sizeof(struct packet_mreq)) 3818 return -EINVAL; 3819 if (len > sizeof(mreq)) 3820 len = sizeof(mreq); 3821 if (copy_from_sockptr(&mreq, optval, len)) 3822 return -EFAULT; 3823 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3824 return -EINVAL; 3825 if (optname == PACKET_ADD_MEMBERSHIP) 3826 ret = packet_mc_add(sk, &mreq); 3827 else 3828 ret = packet_mc_drop(sk, &mreq); 3829 return ret; 3830 } 3831 3832 case PACKET_RX_RING: 3833 case PACKET_TX_RING: 3834 { 3835 union tpacket_req_u req_u; 3836 3837 ret = -EINVAL; 3838 lock_sock(sk); 3839 switch (po->tp_version) { 3840 case TPACKET_V1: 3841 case TPACKET_V2: 3842 if (optlen < sizeof(req_u.req)) 3843 break; 3844 ret = copy_from_sockptr(&req_u.req, optval, 3845 sizeof(req_u.req)) ? 3846 -EINVAL : 0; 3847 break; 3848 case TPACKET_V3: 3849 default: 3850 if (optlen < sizeof(req_u.req3)) 3851 break; 3852 ret = copy_from_sockptr(&req_u.req3, optval, 3853 sizeof(req_u.req3)) ? 3854 -EINVAL : 0; 3855 break; 3856 } 3857 if (!ret) 3858 ret = packet_set_ring(sk, &req_u, 0, 3859 optname == PACKET_TX_RING); 3860 release_sock(sk); 3861 return ret; 3862 } 3863 case PACKET_COPY_THRESH: 3864 { 3865 int val; 3866 3867 if (optlen != sizeof(val)) 3868 return -EINVAL; 3869 if (copy_from_sockptr(&val, optval, sizeof(val))) 3870 return -EFAULT; 3871 3872 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3873 return 0; 3874 } 3875 case PACKET_VERSION: 3876 { 3877 int val; 3878 3879 if (optlen != sizeof(val)) 3880 return -EINVAL; 3881 if (copy_from_sockptr(&val, optval, sizeof(val))) 3882 return -EFAULT; 3883 switch (val) { 3884 case TPACKET_V1: 3885 case TPACKET_V2: 3886 case TPACKET_V3: 3887 break; 3888 default: 3889 return -EINVAL; 3890 } 3891 lock_sock(sk); 3892 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3893 ret = -EBUSY; 3894 } else { 3895 po->tp_version = val; 3896 ret = 0; 3897 } 3898 release_sock(sk); 3899 return ret; 3900 } 3901 case PACKET_RESERVE: 3902 { 3903 unsigned int val; 3904 3905 if (optlen != sizeof(val)) 3906 return -EINVAL; 3907 if (copy_from_sockptr(&val, optval, sizeof(val))) 3908 return -EFAULT; 3909 if (val > INT_MAX) 3910 return -EINVAL; 3911 lock_sock(sk); 3912 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3913 ret = -EBUSY; 3914 } else { 3915 po->tp_reserve = val; 3916 ret = 0; 3917 } 3918 release_sock(sk); 3919 return ret; 3920 } 3921 case PACKET_LOSS: 3922 { 3923 unsigned int val; 3924 3925 if (optlen != sizeof(val)) 3926 return -EINVAL; 3927 if (copy_from_sockptr(&val, optval, sizeof(val))) 3928 return -EFAULT; 3929 3930 lock_sock(sk); 3931 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3932 ret = -EBUSY; 3933 } else { 3934 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3935 ret = 0; 3936 } 3937 release_sock(sk); 3938 return ret; 3939 } 3940 case PACKET_AUXDATA: 3941 { 3942 int val; 3943 3944 if (optlen < sizeof(val)) 3945 return -EINVAL; 3946 if (copy_from_sockptr(&val, optval, sizeof(val))) 3947 return -EFAULT; 3948 3949 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3950 return 0; 3951 } 3952 case PACKET_ORIGDEV: 3953 { 3954 int val; 3955 3956 if (optlen < sizeof(val)) 3957 return -EINVAL; 3958 if (copy_from_sockptr(&val, optval, sizeof(val))) 3959 return -EFAULT; 3960 3961 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 3962 return 0; 3963 } 3964 case PACKET_VNET_HDR: 3965 case PACKET_VNET_HDR_SZ: 3966 { 3967 int val, hdr_len; 3968 3969 if (sock->type != SOCK_RAW) 3970 return -EINVAL; 3971 if (optlen < sizeof(val)) 3972 return -EINVAL; 3973 if (copy_from_sockptr(&val, optval, sizeof(val))) 3974 return -EFAULT; 3975 3976 if (optname == PACKET_VNET_HDR_SZ) { 3977 if (val && val != sizeof(struct virtio_net_hdr) && 3978 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 3979 return -EINVAL; 3980 hdr_len = val; 3981 } else { 3982 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 3983 } 3984 lock_sock(sk); 3985 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3986 ret = -EBUSY; 3987 } else { 3988 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 3989 ret = 0; 3990 } 3991 release_sock(sk); 3992 return ret; 3993 } 3994 case PACKET_TIMESTAMP: 3995 { 3996 int val; 3997 3998 if (optlen != sizeof(val)) 3999 return -EINVAL; 4000 if (copy_from_sockptr(&val, optval, sizeof(val))) 4001 return -EFAULT; 4002 4003 WRITE_ONCE(po->tp_tstamp, val); 4004 return 0; 4005 } 4006 case PACKET_FANOUT: 4007 { 4008 struct fanout_args args = { 0 }; 4009 4010 if (optlen != sizeof(int) && optlen != sizeof(args)) 4011 return -EINVAL; 4012 if (copy_from_sockptr(&args, optval, optlen)) 4013 return -EFAULT; 4014 4015 return fanout_add(sk, &args); 4016 } 4017 case PACKET_FANOUT_DATA: 4018 { 4019 /* Paired with the WRITE_ONCE() in fanout_add() */ 4020 if (!READ_ONCE(po->fanout)) 4021 return -EINVAL; 4022 4023 return fanout_set_data(po, optval, optlen); 4024 } 4025 case PACKET_IGNORE_OUTGOING: 4026 { 4027 int val; 4028 4029 if (optlen != sizeof(val)) 4030 return -EINVAL; 4031 if (copy_from_sockptr(&val, optval, sizeof(val))) 4032 return -EFAULT; 4033 if (val < 0 || val > 1) 4034 return -EINVAL; 4035 4036 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4037 return 0; 4038 } 4039 case PACKET_TX_HAS_OFF: 4040 { 4041 unsigned int val; 4042 4043 if (optlen != sizeof(val)) 4044 return -EINVAL; 4045 if (copy_from_sockptr(&val, optval, sizeof(val))) 4046 return -EFAULT; 4047 4048 lock_sock(sk); 4049 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4050 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4051 4052 release_sock(sk); 4053 return 0; 4054 } 4055 case PACKET_QDISC_BYPASS: 4056 { 4057 int val; 4058 4059 if (optlen != sizeof(val)) 4060 return -EINVAL; 4061 if (copy_from_sockptr(&val, optval, sizeof(val))) 4062 return -EFAULT; 4063 4064 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4065 return 0; 4066 } 4067 default: 4068 return -ENOPROTOOPT; 4069 } 4070 } 4071 4072 static int packet_getsockopt(struct socket *sock, int level, int optname, 4073 sockopt_t *opt) 4074 { 4075 int len; 4076 int val, lv = sizeof(val); 4077 struct sock *sk = sock->sk; 4078 struct packet_sock *po = pkt_sk(sk); 4079 void *data = &val; 4080 union tpacket_stats_u st; 4081 struct tpacket_rollover_stats rstats; 4082 int drops; 4083 4084 if (level != SOL_PACKET) 4085 return -ENOPROTOOPT; 4086 4087 len = opt->optlen; 4088 4089 if (len < 0) 4090 return -EINVAL; 4091 4092 switch (optname) { 4093 case PACKET_STATISTICS: 4094 spin_lock_bh(&sk->sk_receive_queue.lock); 4095 memcpy(&st, &po->stats, sizeof(st)); 4096 memset(&po->stats, 0, sizeof(po->stats)); 4097 spin_unlock_bh(&sk->sk_receive_queue.lock); 4098 drops = atomic_xchg(&po->tp_drops, 0); 4099 4100 if (po->tp_version == TPACKET_V3) { 4101 lv = sizeof(struct tpacket_stats_v3); 4102 st.stats3.tp_drops = drops; 4103 st.stats3.tp_packets += drops; 4104 data = &st.stats3; 4105 } else { 4106 lv = sizeof(struct tpacket_stats); 4107 st.stats1.tp_drops = drops; 4108 st.stats1.tp_packets += drops; 4109 data = &st.stats1; 4110 } 4111 4112 break; 4113 case PACKET_AUXDATA: 4114 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4115 break; 4116 case PACKET_ORIGDEV: 4117 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4118 break; 4119 case PACKET_VNET_HDR: 4120 val = !!READ_ONCE(po->vnet_hdr_sz); 4121 break; 4122 case PACKET_VNET_HDR_SZ: 4123 val = READ_ONCE(po->vnet_hdr_sz); 4124 break; 4125 case PACKET_COPY_THRESH: 4126 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4127 break; 4128 case PACKET_VERSION: 4129 val = po->tp_version; 4130 break; 4131 case PACKET_HDRLEN: 4132 if (len > sizeof(int)) 4133 len = sizeof(int); 4134 if (len < sizeof(int)) 4135 return -EINVAL; 4136 if (copy_from_iter(&val, len, &opt->iter_in) != len) 4137 return -EFAULT; 4138 switch (val) { 4139 case TPACKET_V1: 4140 val = sizeof(struct tpacket_hdr); 4141 break; 4142 case TPACKET_V2: 4143 val = sizeof(struct tpacket2_hdr); 4144 break; 4145 case TPACKET_V3: 4146 val = sizeof(struct tpacket3_hdr); 4147 break; 4148 default: 4149 return -EINVAL; 4150 } 4151 break; 4152 case PACKET_RESERVE: 4153 val = po->tp_reserve; 4154 break; 4155 case PACKET_LOSS: 4156 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4157 break; 4158 case PACKET_TIMESTAMP: 4159 val = READ_ONCE(po->tp_tstamp); 4160 break; 4161 case PACKET_FANOUT: 4162 val = (po->fanout ? 4163 ((u32)po->fanout->id | 4164 ((u32)po->fanout->type << 16) | 4165 ((u32)po->fanout->flags << 24)) : 4166 0); 4167 break; 4168 case PACKET_IGNORE_OUTGOING: 4169 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4170 break; 4171 case PACKET_ROLLOVER_STATS: 4172 if (!po->rollover) 4173 return -EINVAL; 4174 rstats.tp_all = atomic_long_read(&po->rollover->num); 4175 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4176 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4177 data = &rstats; 4178 lv = sizeof(rstats); 4179 break; 4180 case PACKET_TX_HAS_OFF: 4181 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4182 break; 4183 case PACKET_QDISC_BYPASS: 4184 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4185 break; 4186 default: 4187 return -ENOPROTOOPT; 4188 } 4189 4190 if (len > lv) 4191 len = lv; 4192 opt->optlen = len; 4193 if (copy_to_iter(data, len, &opt->iter_out) != len) 4194 return -EFAULT; 4195 return 0; 4196 } 4197 4198 static int packet_notifier(struct notifier_block *this, 4199 unsigned long msg, void *ptr) 4200 { 4201 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4202 struct net *net = dev_net(dev); 4203 struct packet_mclist *ml, *tmp; 4204 LIST_HEAD(mclist); 4205 struct sock *sk; 4206 4207 rcu_read_lock(); 4208 sk_for_each_rcu(sk, &net->packet.sklist) { 4209 struct packet_sock *po = pkt_sk(sk); 4210 4211 switch (msg) { 4212 case NETDEV_UNREGISTER: 4213 if (po->mclist) 4214 packet_dev_mclist_delete(dev, &po->mclist, 4215 &mclist); 4216 fallthrough; 4217 4218 case NETDEV_DOWN: 4219 if (dev->ifindex == po->ifindex) { 4220 spin_lock(&po->bind_lock); 4221 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4222 __unregister_prot_hook(sk, false); 4223 sk->sk_err = ENETDOWN; 4224 if (!sock_flag(sk, SOCK_DEAD)) 4225 sk_error_report(sk); 4226 } 4227 if (msg == NETDEV_UNREGISTER) { 4228 packet_cached_dev_reset(po); 4229 WRITE_ONCE(po->ifindex, -1); 4230 netdev_put(po->prot_hook.dev, 4231 &po->prot_hook.dev_tracker); 4232 po->prot_hook.dev = NULL; 4233 } 4234 spin_unlock(&po->bind_lock); 4235 } 4236 break; 4237 case NETDEV_UP: 4238 if (dev->ifindex == po->ifindex) { 4239 spin_lock(&po->bind_lock); 4240 if (po->num) 4241 register_prot_hook(sk); 4242 spin_unlock(&po->bind_lock); 4243 } 4244 break; 4245 } 4246 } 4247 rcu_read_unlock(); 4248 4249 /* packet_dev_mc might grab instance locks so can't run under rcu */ 4250 list_for_each_entry_safe(ml, tmp, &mclist, remove_list) { 4251 packet_dev_mc(dev, ml, -1); 4252 kfree(ml); 4253 } 4254 4255 return NOTIFY_DONE; 4256 } 4257 4258 4259 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4260 unsigned long arg) 4261 { 4262 struct sock *sk = sock->sk; 4263 4264 switch (cmd) { 4265 case SIOCOUTQ: 4266 { 4267 int amount = sk_wmem_alloc_get(sk); 4268 4269 return put_user(amount, (int __user *)arg); 4270 } 4271 case SIOCINQ: 4272 { 4273 struct sk_buff *skb; 4274 int amount = 0; 4275 4276 spin_lock_bh(&sk->sk_receive_queue.lock); 4277 skb = skb_peek(&sk->sk_receive_queue); 4278 if (skb) 4279 amount = skb->len; 4280 spin_unlock_bh(&sk->sk_receive_queue.lock); 4281 return put_user(amount, (int __user *)arg); 4282 } 4283 #ifdef CONFIG_INET 4284 case SIOCADDRT: 4285 case SIOCDELRT: 4286 case SIOCDARP: 4287 case SIOCGARP: 4288 case SIOCSARP: 4289 case SIOCGIFADDR: 4290 case SIOCSIFADDR: 4291 case SIOCGIFBRDADDR: 4292 case SIOCSIFBRDADDR: 4293 case SIOCGIFNETMASK: 4294 case SIOCSIFNETMASK: 4295 case SIOCGIFDSTADDR: 4296 case SIOCSIFDSTADDR: 4297 case SIOCSIFFLAGS: 4298 return inet_dgram_ops.ioctl(sock, cmd, arg); 4299 #endif 4300 4301 default: 4302 return -ENOIOCTLCMD; 4303 } 4304 return 0; 4305 } 4306 4307 static __poll_t packet_poll(struct file *file, struct socket *sock, 4308 poll_table *wait) 4309 { 4310 struct sock *sk = sock->sk; 4311 struct packet_sock *po = pkt_sk(sk); 4312 __poll_t mask = datagram_poll(file, sock, wait); 4313 4314 spin_lock_bh(&sk->sk_receive_queue.lock); 4315 if (po->rx_ring.pg_vec) { 4316 if (!packet_previous_rx_frame(po, &po->rx_ring, 4317 TP_STATUS_KERNEL)) 4318 mask |= EPOLLIN | EPOLLRDNORM; 4319 } 4320 __packet_rcv_try_clear_pressure(po); 4321 spin_unlock_bh(&sk->sk_receive_queue.lock); 4322 spin_lock_bh(&sk->sk_write_queue.lock); 4323 if (po->tx_ring.pg_vec) { 4324 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4325 mask |= EPOLLOUT | EPOLLWRNORM; 4326 } 4327 spin_unlock_bh(&sk->sk_write_queue.lock); 4328 return mask; 4329 } 4330 4331 4332 /* Dirty? Well, I still did not learn better way to account 4333 * for user mmaps. 4334 */ 4335 4336 static void packet_mm_open(struct vm_area_struct *vma) 4337 { 4338 struct file *file = vma->vm_file; 4339 struct socket *sock = file->private_data; 4340 struct sock *sk = sock->sk; 4341 4342 if (sk) 4343 atomic_long_inc(&pkt_sk(sk)->mapped); 4344 } 4345 4346 static void packet_mm_close(struct vm_area_struct *vma) 4347 { 4348 struct file *file = vma->vm_file; 4349 struct socket *sock = file->private_data; 4350 struct sock *sk = sock->sk; 4351 4352 if (sk) 4353 atomic_long_dec(&pkt_sk(sk)->mapped); 4354 } 4355 4356 static const struct vm_operations_struct packet_mmap_ops = { 4357 .open = packet_mm_open, 4358 .close = packet_mm_close, 4359 }; 4360 4361 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4362 unsigned int len) 4363 { 4364 int i; 4365 4366 for (i = 0; i < len; i++) { 4367 if (likely(pg_vec[i].buffer)) { 4368 if (is_vmalloc_addr(pg_vec[i].buffer)) 4369 vfree(pg_vec[i].buffer); 4370 else 4371 free_pages((unsigned long)pg_vec[i].buffer, 4372 order); 4373 pg_vec[i].buffer = NULL; 4374 } 4375 } 4376 kfree(pg_vec); 4377 } 4378 4379 static char *alloc_one_pg_vec_page(unsigned long order) 4380 { 4381 char *buffer; 4382 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4383 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4384 4385 buffer = (char *) __get_free_pages(gfp_flags, order); 4386 if (buffer) 4387 return buffer; 4388 4389 /* __get_free_pages failed, fall back to vmalloc */ 4390 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4391 if (buffer) 4392 return buffer; 4393 4394 /* vmalloc failed, lets dig into swap here */ 4395 gfp_flags &= ~__GFP_NORETRY; 4396 buffer = (char *) __get_free_pages(gfp_flags, order); 4397 if (buffer) 4398 return buffer; 4399 4400 /* complete and utter failure */ 4401 return NULL; 4402 } 4403 4404 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4405 { 4406 unsigned int block_nr = req->tp_block_nr; 4407 struct pgv *pg_vec; 4408 int i; 4409 4410 pg_vec = kzalloc_objs(struct pgv, block_nr, GFP_KERNEL | __GFP_NOWARN); 4411 if (unlikely(!pg_vec)) 4412 goto out; 4413 4414 for (i = 0; i < block_nr; i++) { 4415 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4416 if (unlikely(!pg_vec[i].buffer)) 4417 goto out_free_pgvec; 4418 } 4419 4420 out: 4421 return pg_vec; 4422 4423 out_free_pgvec: 4424 free_pg_vec(pg_vec, order, block_nr); 4425 pg_vec = NULL; 4426 goto out; 4427 } 4428 4429 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4430 int closing, int tx_ring) 4431 { 4432 struct pgv *pg_vec = NULL; 4433 struct packet_sock *po = pkt_sk(sk); 4434 unsigned long *rx_owner_map = NULL; 4435 int was_running, order = 0; 4436 struct packet_ring_buffer *rb; 4437 struct sk_buff_head *rb_queue; 4438 __be16 num; 4439 int err; 4440 /* Added to avoid minimal code churn */ 4441 struct tpacket_req *req = &req_u->req; 4442 4443 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4444 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4445 4446 err = -EBUSY; 4447 if (!closing) { 4448 if (atomic_long_read(&po->mapped)) 4449 goto out; 4450 if (packet_read_pending(rb)) 4451 goto out; 4452 } 4453 4454 if (req->tp_block_nr) { 4455 unsigned int min_frame_size; 4456 4457 /* Sanity tests and some calculations */ 4458 err = -EBUSY; 4459 if (unlikely(rb->pg_vec)) 4460 goto out; 4461 4462 switch (po->tp_version) { 4463 case TPACKET_V1: 4464 po->tp_hdrlen = TPACKET_HDRLEN; 4465 break; 4466 case TPACKET_V2: 4467 po->tp_hdrlen = TPACKET2_HDRLEN; 4468 break; 4469 case TPACKET_V3: 4470 po->tp_hdrlen = TPACKET3_HDRLEN; 4471 break; 4472 } 4473 4474 err = -EINVAL; 4475 if (unlikely((int)req->tp_block_size <= 0)) 4476 goto out; 4477 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4478 goto out; 4479 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4480 if (po->tp_version >= TPACKET_V3 && 4481 req->tp_block_size < 4482 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4483 goto out; 4484 if (unlikely(req->tp_frame_size < min_frame_size)) 4485 goto out; 4486 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4487 goto out; 4488 4489 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4490 if (unlikely(rb->frames_per_block == 0)) 4491 goto out; 4492 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4493 goto out; 4494 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4495 req->tp_frame_nr)) 4496 goto out; 4497 4498 err = -ENOMEM; 4499 order = get_order(req->tp_block_size); 4500 pg_vec = alloc_pg_vec(req, order); 4501 if (unlikely(!pg_vec)) 4502 goto out; 4503 switch (po->tp_version) { 4504 case TPACKET_V3: 4505 /* Block transmit is not supported yet */ 4506 if (!tx_ring) { 4507 init_prb_bdqc(po, rb, pg_vec, req_u); 4508 } else { 4509 struct tpacket_req3 *req3 = &req_u->req3; 4510 4511 if (req3->tp_retire_blk_tov || 4512 req3->tp_sizeof_priv || 4513 req3->tp_feature_req_word) { 4514 err = -EINVAL; 4515 goto out_free_pg_vec; 4516 } 4517 } 4518 break; 4519 default: 4520 if (!tx_ring) { 4521 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4522 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4523 if (!rx_owner_map) 4524 goto out_free_pg_vec; 4525 } 4526 break; 4527 } 4528 } 4529 /* Done */ 4530 else { 4531 err = -EINVAL; 4532 if (unlikely(req->tp_frame_nr)) 4533 goto out; 4534 } 4535 4536 4537 /* Detach socket from network */ 4538 spin_lock(&po->bind_lock); 4539 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4540 num = po->num; 4541 WRITE_ONCE(po->num, 0); 4542 if (was_running) 4543 __unregister_prot_hook(sk, false); 4544 4545 spin_unlock(&po->bind_lock); 4546 4547 synchronize_net(); 4548 4549 err = -EBUSY; 4550 mutex_lock(&po->pg_vec_lock); 4551 if (closing || atomic_long_read(&po->mapped) == 0) { 4552 err = 0; 4553 spin_lock_bh(&rb_queue->lock); 4554 swap(rb->pg_vec, pg_vec); 4555 if (po->tp_version <= TPACKET_V2) 4556 swap(rb->rx_owner_map, rx_owner_map); 4557 rb->frame_max = (req->tp_frame_nr - 1); 4558 rb->head = 0; 4559 rb->frame_size = req->tp_frame_size; 4560 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4561 tpacket_rcv : packet_rcv; 4562 spin_unlock_bh(&rb_queue->lock); 4563 4564 swap(rb->pg_vec_order, order); 4565 swap(rb->pg_vec_len, req->tp_block_nr); 4566 4567 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4568 skb_queue_purge(rb_queue); 4569 if (atomic_long_read(&po->mapped)) 4570 pr_err("packet_mmap: vma is busy: %ld\n", 4571 atomic_long_read(&po->mapped)); 4572 } 4573 mutex_unlock(&po->pg_vec_lock); 4574 4575 spin_lock(&po->bind_lock); 4576 WRITE_ONCE(po->num, num); 4577 /* 4578 * NETDEV_UNREGISTER may have invalidated the binding while bind_lock 4579 * was dropped above. Do not re-add a fanout hook to a dead device. 4580 */ 4581 if (was_running && READ_ONCE(po->ifindex) != -1) 4582 register_prot_hook(sk); 4583 4584 spin_unlock(&po->bind_lock); 4585 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4586 /* Because we don't support block-based V3 on tx-ring */ 4587 if (!tx_ring) 4588 prb_shutdown_retire_blk_timer(po, rb_queue); 4589 } 4590 4591 out_free_pg_vec: 4592 if (pg_vec) { 4593 bitmap_free(rx_owner_map); 4594 free_pg_vec(pg_vec, order, req->tp_block_nr); 4595 } 4596 out: 4597 return err; 4598 } 4599 4600 static int packet_mmap(struct file *file, struct socket *sock, 4601 struct vm_area_struct *vma) 4602 { 4603 struct sock *sk = sock->sk; 4604 struct packet_sock *po = pkt_sk(sk); 4605 unsigned long size, expected_size; 4606 struct packet_ring_buffer *rb; 4607 unsigned long start; 4608 int err = -EINVAL; 4609 int i; 4610 4611 if (vma->vm_pgoff) 4612 return -EINVAL; 4613 4614 mutex_lock(&po->pg_vec_lock); 4615 4616 expected_size = 0; 4617 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4618 if (rb->pg_vec) { 4619 expected_size += rb->pg_vec_len 4620 * rb->pg_vec_pages 4621 * PAGE_SIZE; 4622 } 4623 } 4624 4625 if (expected_size == 0) 4626 goto out; 4627 4628 size = vma->vm_end - vma->vm_start; 4629 if (size != expected_size) 4630 goto out; 4631 4632 start = vma->vm_start; 4633 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4634 if (rb->pg_vec == NULL) 4635 continue; 4636 4637 for (i = 0; i < rb->pg_vec_len; i++) { 4638 struct page *page; 4639 void *kaddr = rb->pg_vec[i].buffer; 4640 int pg_num; 4641 4642 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4643 page = pgv_to_page(kaddr); 4644 err = vm_insert_page(vma, start, page); 4645 if (unlikely(err)) 4646 goto out; 4647 start += PAGE_SIZE; 4648 kaddr += PAGE_SIZE; 4649 } 4650 } 4651 } 4652 4653 atomic_long_inc(&po->mapped); 4654 vma->vm_ops = &packet_mmap_ops; 4655 err = 0; 4656 4657 out: 4658 mutex_unlock(&po->pg_vec_lock); 4659 return err; 4660 } 4661 4662 static const struct proto_ops packet_ops_spkt = { 4663 .family = PF_PACKET, 4664 .owner = THIS_MODULE, 4665 .release = packet_release, 4666 .bind = packet_bind_spkt, 4667 .connect = sock_no_connect, 4668 .socketpair = sock_no_socketpair, 4669 .accept = sock_no_accept, 4670 .getname = packet_getname_spkt, 4671 .poll = datagram_poll, 4672 .ioctl = packet_ioctl, 4673 .gettstamp = sock_gettstamp, 4674 .listen = sock_no_listen, 4675 .shutdown = sock_no_shutdown, 4676 .sendmsg = packet_sendmsg_spkt, 4677 .recvmsg = packet_recvmsg, 4678 .mmap = sock_no_mmap, 4679 }; 4680 4681 static const struct proto_ops packet_ops = { 4682 .family = PF_PACKET, 4683 .owner = THIS_MODULE, 4684 .release = packet_release, 4685 .bind = packet_bind, 4686 .connect = sock_no_connect, 4687 .socketpair = sock_no_socketpair, 4688 .accept = sock_no_accept, 4689 .getname = packet_getname, 4690 .poll = packet_poll, 4691 .ioctl = packet_ioctl, 4692 .gettstamp = sock_gettstamp, 4693 .listen = sock_no_listen, 4694 .shutdown = sock_no_shutdown, 4695 .setsockopt = packet_setsockopt, 4696 .getsockopt_iter = packet_getsockopt, 4697 .sendmsg = packet_sendmsg, 4698 .recvmsg = packet_recvmsg, 4699 .mmap = packet_mmap, 4700 }; 4701 4702 static const struct net_proto_family packet_family_ops = { 4703 .family = PF_PACKET, 4704 .create = packet_create, 4705 .owner = THIS_MODULE, 4706 }; 4707 4708 static struct notifier_block packet_netdev_notifier = { 4709 .notifier_call = packet_notifier, 4710 }; 4711 4712 #ifdef CONFIG_PROC_FS 4713 4714 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4715 __acquires(RCU) 4716 { 4717 struct net *net = seq_file_net(seq); 4718 4719 rcu_read_lock(); 4720 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4721 } 4722 4723 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4724 { 4725 struct net *net = seq_file_net(seq); 4726 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4727 } 4728 4729 static void packet_seq_stop(struct seq_file *seq, void *v) 4730 __releases(RCU) 4731 { 4732 rcu_read_unlock(); 4733 } 4734 4735 static int packet_seq_show(struct seq_file *seq, void *v) 4736 { 4737 if (v == SEQ_START_TOKEN) 4738 seq_printf(seq, 4739 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4740 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4741 else { 4742 struct sock *s = sk_entry(v); 4743 const struct packet_sock *po = pkt_sk(s); 4744 4745 seq_printf(seq, 4746 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6llu\n", 4747 s, 4748 refcount_read(&s->sk_refcnt), 4749 s->sk_type, 4750 ntohs(READ_ONCE(po->num)), 4751 READ_ONCE(po->ifindex), 4752 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4753 atomic_read(&s->sk_rmem_alloc), 4754 from_kuid_munged(seq_user_ns(seq), sk_uid(s)), 4755 sock_i_ino(s)); 4756 } 4757 4758 return 0; 4759 } 4760 4761 static const struct seq_operations packet_seq_ops = { 4762 .start = packet_seq_start, 4763 .next = packet_seq_next, 4764 .stop = packet_seq_stop, 4765 .show = packet_seq_show, 4766 }; 4767 #endif 4768 4769 static int __net_init packet_net_init(struct net *net) 4770 { 4771 mutex_init(&net->packet.sklist_lock); 4772 INIT_HLIST_HEAD(&net->packet.sklist); 4773 4774 #ifdef CONFIG_PROC_FS 4775 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4776 sizeof(struct seq_net_private))) 4777 return -ENOMEM; 4778 #endif /* CONFIG_PROC_FS */ 4779 4780 return 0; 4781 } 4782 4783 static void __net_exit packet_net_exit(struct net *net) 4784 { 4785 remove_proc_entry("packet", net->proc_net); 4786 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4787 } 4788 4789 static struct pernet_operations packet_net_ops = { 4790 .init = packet_net_init, 4791 .exit = packet_net_exit, 4792 }; 4793 4794 4795 static void __exit packet_exit(void) 4796 { 4797 sock_unregister(PF_PACKET); 4798 proto_unregister(&packet_proto); 4799 unregister_netdevice_notifier(&packet_netdev_notifier); 4800 unregister_pernet_subsys(&packet_net_ops); 4801 } 4802 4803 static int __init packet_init(void) 4804 { 4805 int rc; 4806 4807 rc = register_pernet_subsys(&packet_net_ops); 4808 if (rc) 4809 goto out; 4810 rc = register_netdevice_notifier(&packet_netdev_notifier); 4811 if (rc) 4812 goto out_pernet; 4813 rc = proto_register(&packet_proto, 0); 4814 if (rc) 4815 goto out_notifier; 4816 rc = sock_register(&packet_family_ops); 4817 if (rc) 4818 goto out_proto; 4819 4820 return 0; 4821 4822 out_proto: 4823 proto_unregister(&packet_proto); 4824 out_notifier: 4825 unregister_netdevice_notifier(&packet_netdev_notifier); 4826 out_pernet: 4827 unregister_pernet_subsys(&packet_net_ops); 4828 out: 4829 return rc; 4830 } 4831 4832 module_init(packet_init); 4833 module_exit(packet_exit); 4834 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4835 MODULE_LICENSE("GPL"); 4836 MODULE_ALIAS_NETPROTO(PF_PACKET); 4837