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 hard_header_len; 1970 int extra_len = 0; 1971 int err; 1972 1973 /* 1974 * Get and verify the address. 1975 */ 1976 1977 if (saddr) { 1978 if (msg->msg_namelen < sizeof(struct sockaddr)) 1979 return -EINVAL; 1980 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1981 proto = saddr->spkt_protocol; 1982 } else 1983 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1984 1985 /* 1986 * Find the device first to size check it 1987 */ 1988 1989 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1990 retry: 1991 rcu_read_lock(); 1992 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1993 err = -ENODEV; 1994 if (dev == NULL) 1995 goto out_unlock; 1996 1997 err = -ENETDOWN; 1998 if (!(dev->flags & IFF_UP)) 1999 goto out_unlock; 2000 2001 /* 2002 * You may not queue a frame bigger than the mtu. This is the lowest level 2003 * raw protocol and you must do your own fragmentation at this level. 2004 */ 2005 2006 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2007 if (!netif_supports_nofcs(dev)) { 2008 err = -EPROTONOSUPPORT; 2009 goto out_unlock; 2010 } 2011 extra_len = 4; /* We're doing our own CRC */ 2012 } 2013 2014 /* Keep the allocation-time header length across retry. */ 2015 if (!skb) 2016 hard_header_len = READ_ONCE(dev->hard_header_len); 2017 2018 err = -EMSGSIZE; 2019 if (len > dev->mtu + hard_header_len + VLAN_HLEN + extra_len) 2020 goto out_unlock; 2021 2022 if (!skb) { 2023 size_t reserved = LL_RESERVED_SPACE_EX(dev, hard_header_len); 2024 int tlen = dev->needed_tailroom; 2025 unsigned int hhlen = dev->header_ops ? hard_header_len : 0; 2026 2027 rcu_read_unlock(); 2028 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2029 if (skb == NULL) 2030 return -ENOBUFS; 2031 /* FIXME: Save some space for broken drivers that write a hard 2032 * header at transmission time by themselves. PPP is the notable 2033 * one here. This should really be fixed at the driver level. 2034 */ 2035 skb_reserve(skb, reserved); 2036 skb_reset_network_header(skb); 2037 2038 /* Try to align data part correctly */ 2039 if (hhlen) { 2040 skb->data -= hhlen; 2041 skb->tail -= hhlen; 2042 if (len < hhlen) 2043 skb_reset_network_header(skb); 2044 } 2045 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2046 if (err) 2047 goto out_free; 2048 goto retry; 2049 } 2050 2051 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2052 err = -EINVAL; 2053 goto out_unlock; 2054 } 2055 if (len > (dev->mtu + hard_header_len + extra_len) && 2056 !packet_extra_vlan_len_allowed(dev, skb)) { 2057 err = -EMSGSIZE; 2058 goto out_unlock; 2059 } 2060 2061 sockcm_init(&sockc, sk); 2062 if (msg->msg_controllen) { 2063 err = sock_cmsg_send(sk, msg, &sockc); 2064 if (unlikely(err)) 2065 goto out_unlock; 2066 } 2067 2068 skb->protocol = proto; 2069 skb->dev = dev; 2070 skb->priority = sockc.priority; 2071 skb->mark = sockc.mark; 2072 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2073 skb_setup_tx_timestamp(skb, &sockc); 2074 2075 if (unlikely(extra_len == 4)) 2076 skb->no_fcs = 1; 2077 2078 packet_parse_headers(skb, sock); 2079 2080 dev_queue_xmit(skb); 2081 rcu_read_unlock(); 2082 return len; 2083 2084 out_unlock: 2085 rcu_read_unlock(); 2086 out_free: 2087 kfree_skb(skb); 2088 return err; 2089 } 2090 2091 static unsigned int run_filter(struct sk_buff *skb, 2092 const struct sock *sk, 2093 unsigned int res) 2094 { 2095 struct sk_filter *filter; 2096 2097 rcu_read_lock(); 2098 filter = rcu_dereference(sk->sk_filter); 2099 if (filter != NULL) 2100 res = bpf_prog_run_clear_cb(filter->prog, skb); 2101 rcu_read_unlock(); 2102 2103 return res; 2104 } 2105 2106 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2107 size_t *len, int vnet_hdr_sz) 2108 { 2109 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2110 2111 if (*len < vnet_hdr_sz) 2112 return -EINVAL; 2113 *len -= vnet_hdr_sz; 2114 2115 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2116 return -EINVAL; 2117 2118 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2119 } 2120 2121 /* 2122 * This function makes lazy skb cloning in hope that most of packets 2123 * are discarded by BPF. 2124 * 2125 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2126 * and skb->cb are mangled. It works because (and until) packets 2127 * falling here are owned by current CPU. Output packets are cloned 2128 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2129 * sequentially, so that if we return skb to original state on exit, 2130 * we will not harm anyone. 2131 */ 2132 2133 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2134 struct packet_type *pt, struct net_device *orig_dev) 2135 { 2136 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2137 struct sock *sk = NULL; 2138 struct sockaddr_ll *sll; 2139 struct packet_sock *po; 2140 u8 *skb_head = skb->data; 2141 int skb_len = skb->len; 2142 unsigned int snaplen, res; 2143 2144 if (skb->pkt_type == PACKET_LOOPBACK) 2145 goto drop; 2146 2147 sk = pt->af_packet_priv; 2148 po = pkt_sk(sk); 2149 2150 if (!net_eq(dev_net(dev), sock_net(sk))) 2151 goto drop; 2152 2153 skb->dev = dev; 2154 2155 if (dev_has_header(dev)) { 2156 /* The device has an explicit notion of ll header, 2157 * exported to higher levels. 2158 * 2159 * Otherwise, the device hides details of its frame 2160 * structure, so that corresponding packet head is 2161 * never delivered to user. 2162 */ 2163 if (sk->sk_type != SOCK_DGRAM) 2164 skb_push(skb, skb->data - skb_mac_header(skb)); 2165 else if (skb->pkt_type == PACKET_OUTGOING) { 2166 /* Special case: outgoing packets have ll header at head */ 2167 skb_pull(skb, skb_network_offset(skb)); 2168 } 2169 } 2170 2171 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2172 2173 res = run_filter(skb, sk, snaplen); 2174 if (!res) 2175 goto drop_n_restore; 2176 if (snaplen > res) 2177 snaplen = res; 2178 2179 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2180 goto drop_n_acct; 2181 2182 if (skb_shared(skb)) { 2183 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2184 if (nskb == NULL) 2185 goto drop_n_acct; 2186 2187 if (skb_head != skb->data) { 2188 skb->data = skb_head; 2189 skb->len = skb_len; 2190 } 2191 consume_skb(skb); 2192 skb = nskb; 2193 } 2194 2195 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2196 2197 sll = &PACKET_SKB_CB(skb)->sa.ll; 2198 sll->sll_hatype = dev->type; 2199 sll->sll_pkttype = skb->pkt_type; 2200 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2201 sll->sll_ifindex = orig_dev->ifindex; 2202 else 2203 sll->sll_ifindex = dev->ifindex; 2204 2205 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2206 2207 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2208 * Use their space for storing the original skb length. 2209 */ 2210 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2211 2212 if (pskb_trim(skb, snaplen)) 2213 goto drop_n_acct; 2214 2215 skb_set_owner_r(skb, sk); 2216 skb->dev = NULL; 2217 skb_dst_drop(skb); 2218 2219 /* drop conntrack reference */ 2220 nf_reset_ct(skb); 2221 2222 spin_lock(&sk->sk_receive_queue.lock); 2223 po->stats.stats1.tp_packets++; 2224 sock_skb_set_dropcount(sk, skb); 2225 skb_clear_delivery_time(skb); 2226 __skb_queue_tail(&sk->sk_receive_queue, skb); 2227 spin_unlock(&sk->sk_receive_queue.lock); 2228 sk->sk_data_ready(sk); 2229 return 0; 2230 2231 drop_n_acct: 2232 atomic_inc(&po->tp_drops); 2233 sk_drops_inc(sk); 2234 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2235 2236 drop_n_restore: 2237 if (skb_head != skb->data && skb_shared(skb)) { 2238 skb->data = skb_head; 2239 skb->len = skb_len; 2240 } 2241 drop: 2242 sk_skb_reason_drop(sk, skb, drop_reason); 2243 return 0; 2244 } 2245 2246 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2247 struct packet_type *pt, struct net_device *orig_dev) 2248 { 2249 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2250 struct sock *sk = NULL; 2251 struct packet_sock *po; 2252 struct sockaddr_ll *sll; 2253 union tpacket_uhdr h; 2254 u8 *skb_head = skb->data; 2255 int skb_len = skb->len; 2256 unsigned int snaplen, res; 2257 unsigned long status = TP_STATUS_USER; 2258 unsigned short macoff, hdrlen; 2259 unsigned int netoff; 2260 struct sk_buff *copy_skb = NULL; 2261 struct timespec64 ts; 2262 __u32 ts_status; 2263 unsigned int slot_id = 0; 2264 int vnet_hdr_sz = 0; 2265 2266 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2267 * We may add members to them until current aligned size without forcing 2268 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2269 */ 2270 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2271 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2272 2273 if (skb->pkt_type == PACKET_LOOPBACK) 2274 goto drop; 2275 2276 sk = pt->af_packet_priv; 2277 po = pkt_sk(sk); 2278 2279 if (!net_eq(dev_net(dev), sock_net(sk))) 2280 goto drop; 2281 2282 if (dev_has_header(dev)) { 2283 if (sk->sk_type != SOCK_DGRAM) 2284 skb_push(skb, skb->data - skb_mac_header(skb)); 2285 else if (skb->pkt_type == PACKET_OUTGOING) { 2286 /* Special case: outgoing packets have ll header at head */ 2287 skb_pull(skb, skb_network_offset(skb)); 2288 } 2289 } 2290 2291 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2292 2293 res = run_filter(skb, sk, snaplen); 2294 if (!res) 2295 goto drop_n_restore; 2296 2297 /* If we are flooded, just give up */ 2298 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2299 atomic_inc(&po->tp_drops); 2300 goto drop_n_restore; 2301 } 2302 2303 if (skb->ip_summed == CHECKSUM_PARTIAL) 2304 status |= TP_STATUS_CSUMNOTREADY; 2305 else if (skb->pkt_type != PACKET_OUTGOING && 2306 skb_csum_unnecessary(skb)) 2307 status |= TP_STATUS_CSUM_VALID; 2308 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2309 status |= TP_STATUS_GSO_TCP; 2310 2311 if (snaplen > res) 2312 snaplen = res; 2313 2314 if (sk->sk_type == SOCK_DGRAM) { 2315 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2316 po->tp_reserve; 2317 } else { 2318 unsigned int maclen = skb_network_offset(skb); 2319 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2320 (maclen < 16 ? 16 : maclen)) + 2321 po->tp_reserve; 2322 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2323 if (vnet_hdr_sz) 2324 netoff += vnet_hdr_sz; 2325 macoff = netoff - maclen; 2326 } 2327 if (netoff > USHRT_MAX) { 2328 atomic_inc(&po->tp_drops); 2329 goto drop_n_restore; 2330 } 2331 if (po->tp_version <= TPACKET_V2) { 2332 if (macoff + snaplen > po->rx_ring.frame_size) { 2333 if (READ_ONCE(po->copy_thresh) && 2334 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2335 if (skb_shared(skb)) { 2336 copy_skb = skb_clone(skb, GFP_ATOMIC); 2337 } else { 2338 copy_skb = skb_get(skb); 2339 skb_head = skb->data; 2340 } 2341 if (copy_skb) { 2342 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2343 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2344 skb_set_owner_r(copy_skb, sk); 2345 } 2346 } 2347 snaplen = po->rx_ring.frame_size - macoff; 2348 if ((int)snaplen < 0) { 2349 snaplen = 0; 2350 vnet_hdr_sz = 0; 2351 } 2352 } 2353 } else if (unlikely(macoff + snaplen > 2354 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2355 u32 nval; 2356 2357 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2358 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2359 snaplen, nval, macoff); 2360 snaplen = nval; 2361 if (unlikely((int)snaplen < 0)) { 2362 snaplen = 0; 2363 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2364 vnet_hdr_sz = 0; 2365 } 2366 } 2367 spin_lock(&sk->sk_receive_queue.lock); 2368 h.raw = packet_current_rx_frame(po, skb, 2369 TP_STATUS_KERNEL, (macoff+snaplen)); 2370 if (!h.raw) 2371 goto drop_n_account; 2372 2373 if (po->tp_version <= TPACKET_V2) { 2374 slot_id = po->rx_ring.head; 2375 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2376 goto drop_n_account; 2377 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2378 } 2379 2380 if (vnet_hdr_sz && 2381 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2382 sizeof(struct virtio_net_hdr), 2383 vio_le(), true, 0)) { 2384 if (po->tp_version == TPACKET_V3) 2385 prb_clear_blk_fill_status(&po->rx_ring); 2386 goto drop_n_account; 2387 } 2388 2389 if (po->tp_version <= TPACKET_V2) { 2390 packet_increment_rx_head(po, &po->rx_ring); 2391 /* 2392 * LOSING will be reported till you read the stats, 2393 * because it's COR - Clear On Read. 2394 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2395 * at packet level. 2396 */ 2397 if (atomic_read(&po->tp_drops)) 2398 status |= TP_STATUS_LOSING; 2399 } 2400 2401 po->stats.stats1.tp_packets++; 2402 if (copy_skb) { 2403 status |= TP_STATUS_COPY; 2404 skb_clear_delivery_time(copy_skb); 2405 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2406 } 2407 spin_unlock(&sk->sk_receive_queue.lock); 2408 2409 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2410 2411 /* Always timestamp; prefer an existing software timestamp taken 2412 * closer to the time of capture. 2413 */ 2414 ts_status = tpacket_get_timestamp(skb, &ts, 2415 READ_ONCE(po->tp_tstamp) | 2416 SOF_TIMESTAMPING_SOFTWARE); 2417 if (!ts_status) 2418 ktime_get_real_ts64(&ts); 2419 2420 status |= ts_status; 2421 2422 switch (po->tp_version) { 2423 case TPACKET_V1: 2424 h.h1->tp_len = skb->len; 2425 h.h1->tp_snaplen = snaplen; 2426 h.h1->tp_mac = macoff; 2427 h.h1->tp_net = netoff; 2428 h.h1->tp_sec = ts.tv_sec; 2429 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2430 hdrlen = sizeof(*h.h1); 2431 break; 2432 case TPACKET_V2: 2433 h.h2->tp_len = skb->len; 2434 h.h2->tp_snaplen = snaplen; 2435 h.h2->tp_mac = macoff; 2436 h.h2->tp_net = netoff; 2437 h.h2->tp_sec = ts.tv_sec; 2438 h.h2->tp_nsec = ts.tv_nsec; 2439 if (skb_vlan_tag_present(skb)) { 2440 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2441 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2442 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2443 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2444 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2445 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2446 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2447 } else { 2448 h.h2->tp_vlan_tci = 0; 2449 h.h2->tp_vlan_tpid = 0; 2450 } 2451 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2452 hdrlen = sizeof(*h.h2); 2453 break; 2454 case TPACKET_V3: 2455 /* tp_nxt_offset,vlan are already populated above. 2456 * So DONT clear those fields here 2457 */ 2458 h.h3->tp_status |= status; 2459 h.h3->tp_len = skb->len; 2460 h.h3->tp_snaplen = snaplen; 2461 h.h3->tp_mac = macoff; 2462 h.h3->tp_net = netoff; 2463 h.h3->tp_sec = ts.tv_sec; 2464 h.h3->tp_nsec = ts.tv_nsec; 2465 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2466 hdrlen = sizeof(*h.h3); 2467 break; 2468 default: 2469 BUG(); 2470 } 2471 2472 sll = h.raw + TPACKET_ALIGN(hdrlen); 2473 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2474 sll->sll_family = AF_PACKET; 2475 sll->sll_hatype = dev->type; 2476 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2477 vlan_get_protocol_dgram(skb) : skb->protocol; 2478 sll->sll_pkttype = skb->pkt_type; 2479 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2480 sll->sll_ifindex = orig_dev->ifindex; 2481 else 2482 sll->sll_ifindex = dev->ifindex; 2483 2484 smp_mb(); 2485 2486 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2487 if (po->tp_version <= TPACKET_V2) { 2488 u8 *start, *end; 2489 2490 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2491 macoff + snaplen); 2492 2493 for (start = h.raw; start < end; start += PAGE_SIZE) 2494 flush_dcache_page(pgv_to_page(start)); 2495 } 2496 smp_wmb(); 2497 #endif 2498 2499 if (po->tp_version <= TPACKET_V2) { 2500 spin_lock(&sk->sk_receive_queue.lock); 2501 __packet_set_status(po, h.raw, status); 2502 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2503 spin_unlock(&sk->sk_receive_queue.lock); 2504 sk->sk_data_ready(sk); 2505 } else if (po->tp_version == TPACKET_V3) { 2506 prb_clear_blk_fill_status(&po->rx_ring); 2507 } 2508 2509 drop_n_restore: 2510 if (skb_head != skb->data && skb_shared(skb)) { 2511 skb->data = skb_head; 2512 skb->len = skb_len; 2513 } 2514 drop: 2515 sk_skb_reason_drop(sk, skb, drop_reason); 2516 return 0; 2517 2518 drop_n_account: 2519 spin_unlock(&sk->sk_receive_queue.lock); 2520 atomic_inc(&po->tp_drops); 2521 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2522 2523 sk->sk_data_ready(sk); 2524 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2525 goto drop_n_restore; 2526 } 2527 2528 static void tpacket_destruct_skb(struct sk_buff *skb) 2529 { 2530 struct packet_sock *po = pkt_sk(skb->sk); 2531 2532 if (likely(po->tx_ring.pg_vec)) { 2533 void *ph; 2534 __u32 ts; 2535 2536 ph = skb_zcopy_get_nouarg(skb); 2537 packet_dec_pending(&po->tx_ring); 2538 2539 ts = __packet_set_timestamp(po, ph, skb); 2540 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2541 2542 complete(&po->skb_completion); 2543 } 2544 2545 sock_wfree(skb); 2546 } 2547 2548 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2549 { 2550 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2551 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2552 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2553 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2554 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2555 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2556 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2557 2558 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2559 return -EINVAL; 2560 2561 return 0; 2562 } 2563 2564 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2565 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2566 { 2567 int ret; 2568 2569 if (*len < vnet_hdr_sz) 2570 return -EINVAL; 2571 *len -= vnet_hdr_sz; 2572 2573 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2574 return -EFAULT; 2575 2576 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2577 if (ret) 2578 return ret; 2579 2580 /* move iter to point to the start of mac header */ 2581 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2582 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2583 2584 return 0; 2585 } 2586 2587 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2588 void *frame, struct net_device *dev, void *data, int tp_len, 2589 __be16 proto, unsigned char *addr, int hlen, int copylen, 2590 int hard_header_len, 2591 const struct sockcm_cookie *sockc) 2592 { 2593 union tpacket_uhdr ph; 2594 int to_write, offset, len, nr_frags, len_max; 2595 struct socket *sock = po->sk.sk_socket; 2596 struct page *page; 2597 int err; 2598 2599 ph.raw = frame; 2600 2601 skb->protocol = proto; 2602 skb->dev = dev; 2603 skb->priority = sockc->priority; 2604 skb->mark = sockc->mark; 2605 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2606 skb_setup_tx_timestamp(skb, sockc); 2607 skb_zcopy_set_nouarg(skb, ph.raw); 2608 2609 skb_reserve(skb, hlen); 2610 skb_reset_network_header(skb); 2611 2612 to_write = tp_len; 2613 2614 if (sock->type == SOCK_DGRAM) { 2615 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2616 NULL, tp_len); 2617 if (unlikely(err < 0)) 2618 return -EINVAL; 2619 } else if (copylen) { 2620 int hdrlen = min_t(int, copylen, tp_len); 2621 2622 skb_push(skb, hard_header_len); 2623 skb_put(skb, copylen - hard_header_len); 2624 err = skb_store_bits(skb, 0, data, hdrlen); 2625 if (unlikely(err)) 2626 return err; 2627 if (!dev_validate_header(dev, skb->data, hdrlen)) 2628 return -EINVAL; 2629 2630 data += hdrlen; 2631 to_write -= hdrlen; 2632 } 2633 2634 offset = offset_in_page(data); 2635 len_max = PAGE_SIZE - offset; 2636 len = ((to_write > len_max) ? len_max : to_write); 2637 2638 skb->data_len = to_write; 2639 skb->len += to_write; 2640 skb->truesize += to_write; 2641 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2642 2643 while (likely(to_write)) { 2644 nr_frags = skb_shinfo(skb)->nr_frags; 2645 2646 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2647 pr_err("Packet exceed the number of skb frags(%u)\n", 2648 (unsigned int)MAX_SKB_FRAGS); 2649 return -EFAULT; 2650 } 2651 2652 page = pgv_to_page(data); 2653 data += len; 2654 flush_dcache_page(page); 2655 get_page(page); 2656 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2657 to_write -= len; 2658 offset = 0; 2659 len_max = PAGE_SIZE; 2660 len = ((to_write > len_max) ? len_max : to_write); 2661 } 2662 2663 packet_parse_headers(skb, sock); 2664 2665 return tp_len; 2666 } 2667 2668 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2669 int size_max, void **data) 2670 { 2671 union tpacket_uhdr ph; 2672 int tp_len, off; 2673 2674 ph.raw = frame; 2675 2676 switch (po->tp_version) { 2677 case TPACKET_V3: 2678 if (ph.h3->tp_next_offset != 0) { 2679 pr_warn_once("variable sized slot not supported"); 2680 return -EINVAL; 2681 } 2682 tp_len = ph.h3->tp_len; 2683 break; 2684 case TPACKET_V2: 2685 tp_len = ph.h2->tp_len; 2686 break; 2687 default: 2688 tp_len = ph.h1->tp_len; 2689 break; 2690 } 2691 if (unlikely(tp_len > size_max)) { 2692 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2693 return -EMSGSIZE; 2694 } 2695 2696 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2697 int off_min, off_max; 2698 2699 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2700 off_max = po->tx_ring.frame_size - tp_len; 2701 if (po->sk.sk_type == SOCK_DGRAM) { 2702 switch (po->tp_version) { 2703 case TPACKET_V3: 2704 off = ph.h3->tp_net; 2705 break; 2706 case TPACKET_V2: 2707 off = ph.h2->tp_net; 2708 break; 2709 default: 2710 off = ph.h1->tp_net; 2711 break; 2712 } 2713 } else { 2714 switch (po->tp_version) { 2715 case TPACKET_V3: 2716 off = ph.h3->tp_mac; 2717 break; 2718 case TPACKET_V2: 2719 off = ph.h2->tp_mac; 2720 break; 2721 default: 2722 off = ph.h1->tp_mac; 2723 break; 2724 } 2725 } 2726 if (unlikely((off < off_min) || (off_max < off))) 2727 return -EINVAL; 2728 } else { 2729 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2730 } 2731 2732 *data = frame + off; 2733 return tp_len; 2734 } 2735 2736 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2737 { 2738 struct sk_buff *skb = NULL; 2739 struct net_device *dev; 2740 struct virtio_net_hdr vnet_hdr; 2741 bool has_vnet_hdr = false; 2742 struct sockcm_cookie sockc; 2743 __be16 proto; 2744 int err, reserve = 0; 2745 void *ph; 2746 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2747 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2748 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2749 unsigned char *addr = NULL; 2750 int tp_len, size_max; 2751 void *data; 2752 int len_sum = 0; 2753 int status = TP_STATUS_AVAILABLE; 2754 int hard_header_len, hlen, tlen, copylen = 0; 2755 long timeo; 2756 2757 mutex_lock(&po->pg_vec_lock); 2758 2759 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2760 * we need to confirm it under protection of pg_vec_lock. 2761 */ 2762 if (unlikely(!po->tx_ring.pg_vec)) { 2763 err = -EBUSY; 2764 goto out; 2765 } 2766 if (likely(saddr == NULL)) { 2767 dev = packet_cached_dev_get(po); 2768 proto = READ_ONCE(po->num); 2769 } else { 2770 err = -EINVAL; 2771 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2772 goto out; 2773 if (msg->msg_namelen < (saddr->sll_halen 2774 + offsetof(struct sockaddr_ll, 2775 sll_addr))) 2776 goto out; 2777 proto = saddr->sll_protocol; 2778 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2779 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2780 if (dev && msg->msg_namelen < dev->addr_len + 2781 offsetof(struct sockaddr_ll, sll_addr)) 2782 goto out_put; 2783 addr = saddr->sll_addr; 2784 } 2785 } 2786 2787 err = -ENXIO; 2788 if (unlikely(dev == NULL)) 2789 goto out; 2790 err = -ENETDOWN; 2791 if (unlikely(!(dev->flags & IFF_UP))) 2792 goto out_put; 2793 2794 sockcm_init(&sockc, &po->sk); 2795 if (msg->msg_controllen) { 2796 err = sock_cmsg_send(&po->sk, msg, &sockc); 2797 if (unlikely(err)) 2798 goto out_put; 2799 } 2800 2801 hard_header_len = READ_ONCE(dev->hard_header_len); 2802 if (po->sk.sk_socket->type == SOCK_RAW) 2803 reserve = hard_header_len; 2804 size_max = po->tx_ring.frame_size 2805 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2806 2807 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2808 size_max = dev->mtu + reserve + VLAN_HLEN; 2809 2810 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2811 reinit_completion(&po->skb_completion); 2812 2813 do { 2814 ph = packet_current_frame(po, &po->tx_ring, 2815 TP_STATUS_SEND_REQUEST); 2816 if (unlikely(ph == NULL)) { 2817 /* Note: packet_read_pending() might be slow if we 2818 * have to call it as it's per_cpu variable, but in 2819 * fast-path we don't have to call it, only when ph 2820 * is NULL, we need to check the pending_refcnt. 2821 */ 2822 if (need_wait && packet_read_pending(&po->tx_ring)) { 2823 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2824 if (timeo <= 0) { 2825 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2826 goto out_put; 2827 } 2828 /* check for additional frames */ 2829 continue; 2830 } else 2831 break; 2832 } 2833 2834 skb = NULL; 2835 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2836 if (tp_len < 0) 2837 goto tpacket_error; 2838 2839 status = TP_STATUS_SEND_REQUEST; 2840 hlen = LL_RESERVED_SPACE_EX(dev, hard_header_len); 2841 tlen = dev->needed_tailroom; 2842 if (vnet_hdr_sz) { 2843 data += vnet_hdr_sz; 2844 tp_len -= vnet_hdr_sz; 2845 if (tp_len < 0) { 2846 tp_len = -EINVAL; 2847 goto tpacket_error; 2848 } 2849 memcpy(&vnet_hdr, data - vnet_hdr_sz, sizeof(vnet_hdr)); 2850 if (__packet_snd_vnet_parse(&vnet_hdr, tp_len)) { 2851 tp_len = -EINVAL; 2852 goto tpacket_error; 2853 } 2854 copylen = __virtio16_to_cpu(vio_le(), 2855 vnet_hdr.hdr_len); 2856 has_vnet_hdr = true; 2857 } 2858 copylen = max_t(int, copylen, hard_header_len); 2859 skb = sock_alloc_send_skb(&po->sk, 2860 hlen + tlen + sizeof(struct sockaddr_ll) + 2861 (copylen - hard_header_len), 2862 !need_wait, &err); 2863 2864 if (unlikely(skb == NULL)) { 2865 /* we assume the socket was initially writeable ... */ 2866 if (likely(len_sum > 0)) 2867 err = len_sum; 2868 goto out_status; 2869 } 2870 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2871 addr, hlen, copylen, hard_header_len, 2872 &sockc); 2873 if (likely(tp_len >= 0) && 2874 tp_len > dev->mtu + reserve && 2875 !vnet_hdr_sz && 2876 !packet_extra_vlan_len_allowed(dev, skb)) 2877 tp_len = -EMSGSIZE; 2878 2879 if (unlikely(tp_len < 0)) { 2880 tpacket_error: 2881 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2882 __packet_set_status(po, ph, 2883 TP_STATUS_AVAILABLE); 2884 packet_increment_head(&po->tx_ring); 2885 kfree_skb(skb); 2886 continue; 2887 } else { 2888 status = TP_STATUS_WRONG_FORMAT; 2889 err = tp_len; 2890 goto out_status; 2891 } 2892 } 2893 2894 if (has_vnet_hdr) { 2895 if (virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le())) { 2896 tp_len = -EINVAL; 2897 goto tpacket_error; 2898 } 2899 virtio_net_hdr_set_proto(skb, &vnet_hdr); 2900 } 2901 2902 skb->destructor = tpacket_destruct_skb; 2903 __packet_set_status(po, ph, TP_STATUS_SENDING); 2904 packet_inc_pending(&po->tx_ring); 2905 2906 status = TP_STATUS_SEND_REQUEST; 2907 err = packet_xmit(po, skb); 2908 if (unlikely(err != 0)) { 2909 if (err > 0) 2910 err = net_xmit_errno(err); 2911 if (err && __packet_get_status(po, ph) == 2912 TP_STATUS_AVAILABLE) { 2913 /* skb was destructed already */ 2914 skb = NULL; 2915 goto out_status; 2916 } 2917 /* 2918 * skb was dropped but not destructed yet; 2919 * let's treat it like congestion or err < 0 2920 */ 2921 err = 0; 2922 } 2923 packet_increment_head(&po->tx_ring); 2924 len_sum += tp_len; 2925 } while (1); 2926 2927 err = len_sum; 2928 goto out_put; 2929 2930 out_status: 2931 __packet_set_status(po, ph, status); 2932 kfree_skb(skb); 2933 out_put: 2934 dev_put(dev); 2935 out: 2936 mutex_unlock(&po->pg_vec_lock); 2937 return err; 2938 } 2939 2940 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2941 size_t reserve, size_t len, 2942 size_t linear, int noblock, 2943 int *err) 2944 { 2945 struct sk_buff *skb; 2946 2947 /* Under a page? Don't bother with paged skb. */ 2948 if (prepad + len < PAGE_SIZE || !linear) 2949 linear = len; 2950 2951 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2952 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2953 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2954 err, PAGE_ALLOC_COSTLY_ORDER); 2955 if (!skb) 2956 return NULL; 2957 2958 skb_reserve(skb, reserve); 2959 skb_put(skb, linear); 2960 skb->data_len = len - linear; 2961 skb->len += len - linear; 2962 2963 return skb; 2964 } 2965 2966 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2967 { 2968 struct sock *sk = sock->sk; 2969 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2970 struct sk_buff *skb; 2971 struct net_device *dev; 2972 __be16 proto; 2973 unsigned char *addr = NULL; 2974 int err, reserve = 0; 2975 struct sockcm_cookie sockc; 2976 struct virtio_net_hdr vnet_hdr = { 0 }; 2977 int offset = 0; 2978 struct packet_sock *po = pkt_sk(sk); 2979 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2980 int hard_header_len, hlen, tlen, linear; 2981 int extra_len = 0; 2982 2983 /* 2984 * Get and verify the address. 2985 */ 2986 2987 if (likely(saddr == NULL)) { 2988 dev = packet_cached_dev_get(po); 2989 proto = READ_ONCE(po->num); 2990 } else { 2991 err = -EINVAL; 2992 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2993 goto out; 2994 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2995 goto out; 2996 proto = saddr->sll_protocol; 2997 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2998 if (sock->type == SOCK_DGRAM) { 2999 if (dev && msg->msg_namelen < dev->addr_len + 3000 offsetof(struct sockaddr_ll, sll_addr)) 3001 goto out_unlock; 3002 addr = saddr->sll_addr; 3003 } 3004 } 3005 3006 err = -ENXIO; 3007 if (unlikely(dev == NULL)) 3008 goto out_unlock; 3009 err = -ENETDOWN; 3010 if (unlikely(!(dev->flags & IFF_UP))) 3011 goto out_unlock; 3012 3013 sockcm_init(&sockc, sk); 3014 if (msg->msg_controllen) { 3015 err = sock_cmsg_send(sk, msg, &sockc); 3016 if (unlikely(err)) 3017 goto out_unlock; 3018 } 3019 3020 hard_header_len = READ_ONCE(dev->hard_header_len); 3021 if (sock->type == SOCK_RAW) 3022 reserve = hard_header_len; 3023 if (vnet_hdr_sz) { 3024 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3025 if (err) 3026 goto out_unlock; 3027 } 3028 3029 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3030 if (!netif_supports_nofcs(dev)) { 3031 err = -EPROTONOSUPPORT; 3032 goto out_unlock; 3033 } 3034 extra_len = 4; /* We're doing our own CRC */ 3035 } 3036 3037 err = -EMSGSIZE; 3038 if (!vnet_hdr.gso_type && 3039 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3040 goto out_unlock; 3041 3042 err = -ENOBUFS; 3043 hlen = LL_RESERVED_SPACE_EX(dev, hard_header_len); 3044 tlen = dev->needed_tailroom; 3045 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3046 linear = max(linear, min_t(int, len, hard_header_len)); 3047 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3048 msg->msg_flags & MSG_DONTWAIT, &err); 3049 if (skb == NULL) 3050 goto out_unlock; 3051 3052 skb_reset_network_header(skb); 3053 3054 err = -EINVAL; 3055 if (sock->type == SOCK_DGRAM) { 3056 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3057 if (unlikely(offset < 0)) 3058 goto out_free; 3059 } else if (reserve) { 3060 skb_reserve(skb, -reserve); 3061 if (len < reserve + sizeof(struct ipv6hdr) && 3062 dev->min_header_len != hard_header_len) 3063 skb_reset_network_header(skb); 3064 } 3065 3066 /* Returns -EFAULT on error */ 3067 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3068 if (err) 3069 goto out_free; 3070 3071 if ((sock->type == SOCK_RAW && 3072 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3073 err = -EINVAL; 3074 goto out_free; 3075 } 3076 3077 skb_setup_tx_timestamp(skb, &sockc); 3078 3079 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3080 !packet_extra_vlan_len_allowed(dev, skb)) { 3081 err = -EMSGSIZE; 3082 goto out_free; 3083 } 3084 3085 skb->protocol = proto; 3086 skb->dev = dev; 3087 skb->priority = sockc.priority; 3088 skb->mark = sockc.mark; 3089 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3090 3091 if (unlikely(extra_len == 4)) 3092 skb->no_fcs = 1; 3093 3094 packet_parse_headers(skb, sock); 3095 3096 if (vnet_hdr_sz) { 3097 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3098 if (err) 3099 goto out_free; 3100 len += vnet_hdr_sz; 3101 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3102 } 3103 3104 err = packet_xmit(po, skb); 3105 3106 if (unlikely(err != 0)) { 3107 if (err > 0) 3108 err = net_xmit_errno(err); 3109 if (err) 3110 goto out_unlock; 3111 } 3112 3113 dev_put(dev); 3114 3115 return len; 3116 3117 out_free: 3118 kfree_skb(skb); 3119 out_unlock: 3120 dev_put(dev); 3121 out: 3122 return err; 3123 } 3124 3125 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3126 { 3127 struct sock *sk = sock->sk; 3128 struct packet_sock *po = pkt_sk(sk); 3129 3130 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3131 * tpacket_snd() will redo the check safely. 3132 */ 3133 if (data_race(po->tx_ring.pg_vec)) 3134 return tpacket_snd(po, msg); 3135 3136 return packet_snd(sock, msg, len); 3137 } 3138 3139 /* 3140 * Close a PACKET socket. This is fairly simple. We immediately go 3141 * to 'closed' state and remove our protocol entry in the device list. 3142 */ 3143 3144 static int packet_release(struct socket *sock) 3145 { 3146 struct sock *sk = sock->sk; 3147 struct packet_sock *po; 3148 struct packet_fanout *f; 3149 struct net *net; 3150 union tpacket_req_u req_u; 3151 3152 if (!sk) 3153 return 0; 3154 3155 net = sock_net(sk); 3156 po = pkt_sk(sk); 3157 3158 mutex_lock(&net->packet.sklist_lock); 3159 sk_del_node_init_rcu(sk); 3160 mutex_unlock(&net->packet.sklist_lock); 3161 3162 sock_prot_inuse_add(net, sk->sk_prot, -1); 3163 3164 spin_lock(&po->bind_lock); 3165 unregister_prot_hook(sk, false); 3166 WRITE_ONCE(po->num, 0); 3167 packet_cached_dev_reset(po); 3168 3169 if (po->prot_hook.dev) { 3170 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3171 po->prot_hook.dev = NULL; 3172 } 3173 spin_unlock(&po->bind_lock); 3174 3175 packet_flush_mclist(sk); 3176 3177 lock_sock(sk); 3178 if (po->rx_ring.pg_vec) { 3179 memset(&req_u, 0, sizeof(req_u)); 3180 packet_set_ring(sk, &req_u, 1, 0); 3181 } 3182 3183 if (po->tx_ring.pg_vec) { 3184 memset(&req_u, 0, sizeof(req_u)); 3185 packet_set_ring(sk, &req_u, 1, 1); 3186 } 3187 release_sock(sk); 3188 3189 f = fanout_release(sk); 3190 3191 synchronize_net(); 3192 3193 kfree(po->rollover); 3194 if (f) { 3195 fanout_release_data(f); 3196 kvfree(f); 3197 } 3198 /* 3199 * Now the socket is dead. No more input will appear. 3200 */ 3201 sock_orphan(sk); 3202 sock->sk = NULL; 3203 3204 /* Purge queues */ 3205 3206 skb_queue_purge(&sk->sk_receive_queue); 3207 packet_free_pending(po); 3208 3209 sock_put(sk); 3210 return 0; 3211 } 3212 3213 /* 3214 * Attach a packet hook. 3215 */ 3216 3217 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3218 __be16 proto) 3219 { 3220 struct packet_sock *po = pkt_sk(sk); 3221 struct net_device *dev = NULL; 3222 bool unlisted = false; 3223 bool need_rehook; 3224 int ret = 0; 3225 3226 lock_sock(sk); 3227 spin_lock(&po->bind_lock); 3228 if (!proto) 3229 proto = po->num; 3230 3231 rcu_read_lock(); 3232 3233 if (po->fanout) { 3234 ret = -EINVAL; 3235 goto out_unlock; 3236 } 3237 3238 if (name) { 3239 dev = dev_get_by_name_rcu(sock_net(sk), name); 3240 if (!dev) { 3241 ret = -ENODEV; 3242 goto out_unlock; 3243 } 3244 } else if (ifindex) { 3245 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3246 if (!dev) { 3247 ret = -ENODEV; 3248 goto out_unlock; 3249 } 3250 } 3251 3252 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3253 3254 if (need_rehook) { 3255 dev_hold(dev); 3256 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3257 rcu_read_unlock(); 3258 /* prevents packet_notifier() from calling 3259 * register_prot_hook() 3260 */ 3261 WRITE_ONCE(po->num, 0); 3262 __unregister_prot_hook(sk, true); 3263 rcu_read_lock(); 3264 if (dev) 3265 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3266 dev->ifindex); 3267 } 3268 3269 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3270 WRITE_ONCE(po->num, proto); 3271 po->prot_hook.type = proto; 3272 3273 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3274 3275 if (unlikely(unlisted)) { 3276 po->prot_hook.dev = NULL; 3277 WRITE_ONCE(po->ifindex, -1); 3278 packet_cached_dev_reset(po); 3279 } else { 3280 netdev_hold(dev, &po->prot_hook.dev_tracker, 3281 GFP_ATOMIC); 3282 po->prot_hook.dev = dev; 3283 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3284 packet_cached_dev_assign(po, dev); 3285 } 3286 dev_put(dev); 3287 } 3288 3289 if (proto == 0 || !need_rehook) 3290 goto out_unlock; 3291 3292 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3293 register_prot_hook(sk); 3294 } else { 3295 sk->sk_err = ENETDOWN; 3296 if (!sock_flag(sk, SOCK_DEAD)) 3297 sk_error_report(sk); 3298 } 3299 3300 out_unlock: 3301 rcu_read_unlock(); 3302 spin_unlock(&po->bind_lock); 3303 release_sock(sk); 3304 return ret; 3305 } 3306 3307 /* 3308 * Bind a packet socket to a device 3309 */ 3310 3311 static int packet_bind_spkt(struct socket *sock, struct sockaddr_unsized *uaddr, 3312 int addr_len) 3313 { 3314 struct sock *sk = sock->sk; 3315 struct sockaddr *sa = (struct sockaddr *)uaddr; 3316 char name[sizeof(sa->sa_data) + 1]; 3317 3318 /* 3319 * Check legality 3320 */ 3321 3322 if (addr_len != sizeof(struct sockaddr)) 3323 return -EINVAL; 3324 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3325 * zero-terminated. 3326 */ 3327 memcpy(name, sa->sa_data, sizeof(sa->sa_data)); 3328 name[sizeof(sa->sa_data)] = 0; 3329 3330 return packet_do_bind(sk, name, 0, 0); 3331 } 3332 3333 static int packet_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len) 3334 { 3335 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3336 struct sock *sk = sock->sk; 3337 3338 /* 3339 * Check legality 3340 */ 3341 3342 if (addr_len < sizeof(struct sockaddr_ll)) 3343 return -EINVAL; 3344 if (sll->sll_family != AF_PACKET) 3345 return -EINVAL; 3346 3347 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3348 } 3349 3350 static struct proto packet_proto = { 3351 .name = "PACKET", 3352 .owner = THIS_MODULE, 3353 .obj_size = sizeof(struct packet_sock), 3354 }; 3355 3356 /* 3357 * Create a packet of type SOCK_PACKET. 3358 */ 3359 3360 static int packet_create(struct net *net, struct socket *sock, int protocol, 3361 int kern) 3362 { 3363 struct sock *sk; 3364 struct packet_sock *po; 3365 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3366 int err; 3367 3368 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3369 return -EPERM; 3370 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3371 sock->type != SOCK_PACKET) 3372 return -ESOCKTNOSUPPORT; 3373 3374 sock->state = SS_UNCONNECTED; 3375 3376 err = -ENOBUFS; 3377 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3378 if (sk == NULL) 3379 goto out; 3380 3381 sock->ops = &packet_ops; 3382 if (sock->type == SOCK_PACKET) 3383 sock->ops = &packet_ops_spkt; 3384 3385 po = pkt_sk(sk); 3386 err = packet_alloc_pending(po); 3387 if (err) 3388 goto out_sk_free; 3389 3390 sock_init_data(sock, sk); 3391 3392 init_completion(&po->skb_completion); 3393 sk->sk_family = PF_PACKET; 3394 po->num = proto; 3395 3396 packet_cached_dev_reset(po); 3397 3398 sk->sk_destruct = packet_sock_destruct; 3399 3400 /* 3401 * Attach a protocol block 3402 */ 3403 3404 spin_lock_init(&po->bind_lock); 3405 mutex_init(&po->pg_vec_lock); 3406 po->rollover = NULL; 3407 po->prot_hook.func = packet_rcv; 3408 3409 if (sock->type == SOCK_PACKET) 3410 po->prot_hook.func = packet_rcv_spkt; 3411 3412 po->prot_hook.af_packet_priv = sk; 3413 po->prot_hook.af_packet_net = sock_net(sk); 3414 3415 if (proto) { 3416 po->prot_hook.type = proto; 3417 __register_prot_hook(sk); 3418 } 3419 3420 mutex_lock(&net->packet.sklist_lock); 3421 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3422 mutex_unlock(&net->packet.sklist_lock); 3423 3424 sock_prot_inuse_add(net, &packet_proto, 1); 3425 3426 return 0; 3427 out_sk_free: 3428 sk_free(sk); 3429 out: 3430 return err; 3431 } 3432 3433 /* 3434 * Pull a packet from our receive queue and hand it to the user. 3435 * If necessary we block. 3436 */ 3437 3438 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3439 int flags) 3440 { 3441 struct sock *sk = sock->sk; 3442 struct sk_buff *skb; 3443 int copied, err; 3444 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3445 unsigned int origlen = 0; 3446 3447 err = -EINVAL; 3448 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3449 goto out; 3450 3451 #if 0 3452 /* What error should we return now? EUNATTACH? */ 3453 if (pkt_sk(sk)->ifindex < 0) 3454 return -ENODEV; 3455 #endif 3456 3457 if (flags & MSG_ERRQUEUE) { 3458 err = sock_recv_errqueue(sk, msg, len, 3459 SOL_PACKET, PACKET_TX_TIMESTAMP); 3460 goto out; 3461 } 3462 3463 /* 3464 * Call the generic datagram receiver. This handles all sorts 3465 * of horrible races and re-entrancy so we can forget about it 3466 * in the protocol layers. 3467 * 3468 * Now it will return ENETDOWN, if device have just gone down, 3469 * but then it will block. 3470 */ 3471 3472 skb = skb_recv_datagram(sk, flags, &err); 3473 3474 /* 3475 * An error occurred so return it. Because skb_recv_datagram() 3476 * handles the blocking we don't see and worry about blocking 3477 * retries. 3478 */ 3479 3480 if (skb == NULL) 3481 goto out; 3482 3483 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3484 3485 if (vnet_hdr_len) { 3486 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3487 if (err) 3488 goto out_free; 3489 } 3490 3491 /* You lose any data beyond the buffer you gave. If it worries 3492 * a user program they can ask the device for its MTU 3493 * anyway. 3494 */ 3495 copied = skb->len; 3496 if (copied > len) { 3497 copied = len; 3498 msg->msg_flags |= MSG_TRUNC; 3499 } 3500 3501 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3502 if (err) 3503 goto out_free; 3504 3505 if (sock->type != SOCK_PACKET) { 3506 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3507 3508 /* Original length was stored in sockaddr_ll fields */ 3509 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3510 sll->sll_family = AF_PACKET; 3511 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3512 vlan_get_protocol_dgram(skb) : skb->protocol; 3513 } 3514 3515 sock_recv_cmsgs(msg, sk, skb); 3516 3517 if (msg->msg_name) { 3518 const size_t max_len = min(sizeof(skb->cb), 3519 sizeof(struct sockaddr_storage)); 3520 int copy_len; 3521 3522 /* If the address length field is there to be filled 3523 * in, we fill it in now. 3524 */ 3525 if (sock->type == SOCK_PACKET) { 3526 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3527 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3528 copy_len = msg->msg_namelen; 3529 } else { 3530 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3531 3532 msg->msg_namelen = sll->sll_halen + 3533 offsetof(struct sockaddr_ll, sll_addr); 3534 copy_len = msg->msg_namelen; 3535 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3536 memset(msg->msg_name + 3537 offsetof(struct sockaddr_ll, sll_addr), 3538 0, sizeof(sll->sll_addr)); 3539 msg->msg_namelen = sizeof(struct sockaddr_ll); 3540 } 3541 } 3542 if (WARN_ON_ONCE(copy_len > max_len)) { 3543 copy_len = max_len; 3544 msg->msg_namelen = copy_len; 3545 } 3546 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3547 } 3548 3549 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3550 struct tpacket_auxdata aux; 3551 3552 aux.tp_status = TP_STATUS_USER; 3553 if (skb->ip_summed == CHECKSUM_PARTIAL) 3554 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3555 else if (skb->pkt_type != PACKET_OUTGOING && 3556 skb_csum_unnecessary(skb)) 3557 aux.tp_status |= TP_STATUS_CSUM_VALID; 3558 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3559 aux.tp_status |= TP_STATUS_GSO_TCP; 3560 3561 aux.tp_len = origlen; 3562 aux.tp_snaplen = skb->len; 3563 aux.tp_mac = 0; 3564 aux.tp_net = skb_network_offset(skb); 3565 if (skb_vlan_tag_present(skb)) { 3566 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3567 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3568 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3569 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3570 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3571 struct net_device *dev; 3572 3573 rcu_read_lock(); 3574 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3575 if (dev) { 3576 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3577 aux.tp_vlan_tpid = ntohs(skb->protocol); 3578 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3579 } else { 3580 aux.tp_vlan_tci = 0; 3581 aux.tp_vlan_tpid = 0; 3582 } 3583 rcu_read_unlock(); 3584 } else { 3585 aux.tp_vlan_tci = 0; 3586 aux.tp_vlan_tpid = 0; 3587 } 3588 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3589 } 3590 3591 /* 3592 * Free or return the buffer as appropriate. Again this 3593 * hides all the races and re-entrancy issues from us. 3594 */ 3595 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3596 3597 out_free: 3598 skb_free_datagram(sk, skb); 3599 out: 3600 return err; 3601 } 3602 3603 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3604 int peer) 3605 { 3606 struct net_device *dev; 3607 struct sock *sk = sock->sk; 3608 3609 if (peer) 3610 return -EOPNOTSUPP; 3611 3612 uaddr->sa_family = AF_PACKET; 3613 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3614 rcu_read_lock(); 3615 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3616 if (dev) 3617 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3618 rcu_read_unlock(); 3619 3620 return sizeof(*uaddr); 3621 } 3622 3623 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3624 int peer) 3625 { 3626 struct net_device *dev; 3627 struct sock *sk = sock->sk; 3628 struct packet_sock *po = pkt_sk(sk); 3629 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3630 int ifindex; 3631 3632 if (peer) 3633 return -EOPNOTSUPP; 3634 3635 ifindex = READ_ONCE(po->ifindex); 3636 sll->sll_family = AF_PACKET; 3637 sll->sll_ifindex = ifindex; 3638 sll->sll_protocol = READ_ONCE(po->num); 3639 sll->sll_pkttype = 0; 3640 rcu_read_lock(); 3641 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3642 if (dev) { 3643 sll->sll_hatype = dev->type; 3644 sll->sll_halen = dev->addr_len; 3645 3646 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3647 memcpy(((struct sockaddr_storage *)sll)->__data + 3648 offsetof(struct sockaddr_ll, sll_addr) - 3649 offsetofend(struct sockaddr_ll, sll_family), 3650 dev->dev_addr, dev->addr_len); 3651 } else { 3652 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3653 sll->sll_halen = 0; 3654 } 3655 rcu_read_unlock(); 3656 3657 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3658 } 3659 3660 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3661 int what) 3662 { 3663 switch (i->type) { 3664 case PACKET_MR_MULTICAST: 3665 if (i->alen != dev->addr_len) 3666 return -EINVAL; 3667 if (what > 0) 3668 return dev_mc_add(dev, i->addr); 3669 else 3670 return dev_mc_del(dev, i->addr); 3671 break; 3672 case PACKET_MR_PROMISC: 3673 return dev_set_promiscuity(dev, what); 3674 case PACKET_MR_ALLMULTI: 3675 return dev_set_allmulti(dev, what); 3676 case PACKET_MR_UNICAST: 3677 if (i->alen != dev->addr_len) 3678 return -EINVAL; 3679 if (what > 0) 3680 return dev_uc_add(dev, i->addr); 3681 else 3682 return dev_uc_del(dev, i->addr); 3683 break; 3684 default: 3685 break; 3686 } 3687 return 0; 3688 } 3689 3690 static void packet_dev_mclist_delete(struct net_device *dev, 3691 struct packet_mclist **mlp, 3692 struct list_head *list) 3693 { 3694 struct packet_mclist *ml; 3695 3696 while ((ml = *mlp) != NULL) { 3697 if (ml->ifindex == dev->ifindex) { 3698 list_add(&ml->remove_list, list); 3699 *mlp = ml->next; 3700 } else 3701 mlp = &ml->next; 3702 } 3703 } 3704 3705 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3706 { 3707 struct packet_sock *po = pkt_sk(sk); 3708 struct packet_mclist *ml, *i; 3709 struct net_device *dev; 3710 int err; 3711 3712 rtnl_lock(); 3713 3714 err = -ENODEV; 3715 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3716 if (!dev) 3717 goto done; 3718 3719 err = -EINVAL; 3720 if (mreq->mr_alen > dev->addr_len) 3721 goto done; 3722 3723 err = -ENOBUFS; 3724 i = kmalloc_obj(*i); 3725 if (i == NULL) 3726 goto done; 3727 3728 err = 0; 3729 for (ml = po->mclist; ml; ml = ml->next) { 3730 if (ml->ifindex == mreq->mr_ifindex && 3731 ml->type == mreq->mr_type && 3732 ml->alen == mreq->mr_alen && 3733 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3734 ml->count++; 3735 /* Free the new element ... */ 3736 kfree(i); 3737 goto done; 3738 } 3739 } 3740 3741 i->type = mreq->mr_type; 3742 i->ifindex = mreq->mr_ifindex; 3743 i->alen = mreq->mr_alen; 3744 memcpy(i->addr, mreq->mr_address, i->alen); 3745 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3746 i->count = 1; 3747 INIT_LIST_HEAD(&i->remove_list); 3748 i->next = po->mclist; 3749 po->mclist = i; 3750 err = packet_dev_mc(dev, i, 1); 3751 if (err) { 3752 po->mclist = i->next; 3753 kfree(i); 3754 } 3755 3756 done: 3757 rtnl_unlock(); 3758 return err; 3759 } 3760 3761 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3762 { 3763 struct packet_mclist *ml, **mlp; 3764 3765 rtnl_lock(); 3766 3767 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3768 if (ml->ifindex == mreq->mr_ifindex && 3769 ml->type == mreq->mr_type && 3770 ml->alen == mreq->mr_alen && 3771 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3772 if (--ml->count == 0) { 3773 struct net_device *dev; 3774 *mlp = ml->next; 3775 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3776 if (dev) 3777 packet_dev_mc(dev, ml, -1); 3778 kfree(ml); 3779 } 3780 break; 3781 } 3782 } 3783 rtnl_unlock(); 3784 return 0; 3785 } 3786 3787 static void packet_flush_mclist(struct sock *sk) 3788 { 3789 struct packet_sock *po = pkt_sk(sk); 3790 struct packet_mclist *ml; 3791 3792 if (!po->mclist) 3793 return; 3794 3795 rtnl_lock(); 3796 while ((ml = po->mclist) != NULL) { 3797 struct net_device *dev; 3798 3799 po->mclist = ml->next; 3800 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3801 if (dev != NULL) 3802 packet_dev_mc(dev, ml, -1); 3803 kfree(ml); 3804 } 3805 rtnl_unlock(); 3806 } 3807 3808 static int 3809 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3810 unsigned int optlen) 3811 { 3812 struct sock *sk = sock->sk; 3813 struct packet_sock *po = pkt_sk(sk); 3814 int ret; 3815 3816 if (level != SOL_PACKET) 3817 return -ENOPROTOOPT; 3818 3819 switch (optname) { 3820 case PACKET_ADD_MEMBERSHIP: 3821 case PACKET_DROP_MEMBERSHIP: 3822 { 3823 struct packet_mreq_max mreq; 3824 int len = optlen; 3825 memset(&mreq, 0, sizeof(mreq)); 3826 if (len < sizeof(struct packet_mreq)) 3827 return -EINVAL; 3828 if (len > sizeof(mreq)) 3829 len = sizeof(mreq); 3830 if (copy_from_sockptr(&mreq, optval, len)) 3831 return -EFAULT; 3832 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3833 return -EINVAL; 3834 if (optname == PACKET_ADD_MEMBERSHIP) 3835 ret = packet_mc_add(sk, &mreq); 3836 else 3837 ret = packet_mc_drop(sk, &mreq); 3838 return ret; 3839 } 3840 3841 case PACKET_RX_RING: 3842 case PACKET_TX_RING: 3843 { 3844 union tpacket_req_u req_u; 3845 3846 ret = -EINVAL; 3847 lock_sock(sk); 3848 switch (po->tp_version) { 3849 case TPACKET_V1: 3850 case TPACKET_V2: 3851 if (optlen < sizeof(req_u.req)) 3852 break; 3853 ret = copy_from_sockptr(&req_u.req, optval, 3854 sizeof(req_u.req)) ? 3855 -EINVAL : 0; 3856 break; 3857 case TPACKET_V3: 3858 default: 3859 if (optlen < sizeof(req_u.req3)) 3860 break; 3861 ret = copy_from_sockptr(&req_u.req3, optval, 3862 sizeof(req_u.req3)) ? 3863 -EINVAL : 0; 3864 break; 3865 } 3866 if (!ret) 3867 ret = packet_set_ring(sk, &req_u, 0, 3868 optname == PACKET_TX_RING); 3869 release_sock(sk); 3870 return ret; 3871 } 3872 case PACKET_COPY_THRESH: 3873 { 3874 int val; 3875 3876 if (optlen != sizeof(val)) 3877 return -EINVAL; 3878 if (copy_from_sockptr(&val, optval, sizeof(val))) 3879 return -EFAULT; 3880 3881 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3882 return 0; 3883 } 3884 case PACKET_VERSION: 3885 { 3886 int val; 3887 3888 if (optlen != sizeof(val)) 3889 return -EINVAL; 3890 if (copy_from_sockptr(&val, optval, sizeof(val))) 3891 return -EFAULT; 3892 switch (val) { 3893 case TPACKET_V1: 3894 case TPACKET_V2: 3895 case TPACKET_V3: 3896 break; 3897 default: 3898 return -EINVAL; 3899 } 3900 lock_sock(sk); 3901 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3902 ret = -EBUSY; 3903 } else { 3904 po->tp_version = val; 3905 ret = 0; 3906 } 3907 release_sock(sk); 3908 return ret; 3909 } 3910 case PACKET_RESERVE: 3911 { 3912 unsigned int val; 3913 3914 if (optlen != sizeof(val)) 3915 return -EINVAL; 3916 if (copy_from_sockptr(&val, optval, sizeof(val))) 3917 return -EFAULT; 3918 if (val > INT_MAX) 3919 return -EINVAL; 3920 lock_sock(sk); 3921 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3922 ret = -EBUSY; 3923 } else { 3924 po->tp_reserve = val; 3925 ret = 0; 3926 } 3927 release_sock(sk); 3928 return ret; 3929 } 3930 case PACKET_LOSS: 3931 { 3932 unsigned int val; 3933 3934 if (optlen != sizeof(val)) 3935 return -EINVAL; 3936 if (copy_from_sockptr(&val, optval, sizeof(val))) 3937 return -EFAULT; 3938 3939 lock_sock(sk); 3940 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3941 ret = -EBUSY; 3942 } else { 3943 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3944 ret = 0; 3945 } 3946 release_sock(sk); 3947 return ret; 3948 } 3949 case PACKET_AUXDATA: 3950 { 3951 int val; 3952 3953 if (optlen < sizeof(val)) 3954 return -EINVAL; 3955 if (copy_from_sockptr(&val, optval, sizeof(val))) 3956 return -EFAULT; 3957 3958 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3959 return 0; 3960 } 3961 case PACKET_ORIGDEV: 3962 { 3963 int val; 3964 3965 if (optlen < sizeof(val)) 3966 return -EINVAL; 3967 if (copy_from_sockptr(&val, optval, sizeof(val))) 3968 return -EFAULT; 3969 3970 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 3971 return 0; 3972 } 3973 case PACKET_VNET_HDR: 3974 case PACKET_VNET_HDR_SZ: 3975 { 3976 int val, hdr_len; 3977 3978 if (sock->type != SOCK_RAW) 3979 return -EINVAL; 3980 if (optlen < sizeof(val)) 3981 return -EINVAL; 3982 if (copy_from_sockptr(&val, optval, sizeof(val))) 3983 return -EFAULT; 3984 3985 if (optname == PACKET_VNET_HDR_SZ) { 3986 if (val && val != sizeof(struct virtio_net_hdr) && 3987 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 3988 return -EINVAL; 3989 hdr_len = val; 3990 } else { 3991 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 3992 } 3993 lock_sock(sk); 3994 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3995 ret = -EBUSY; 3996 } else { 3997 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 3998 ret = 0; 3999 } 4000 release_sock(sk); 4001 return ret; 4002 } 4003 case PACKET_TIMESTAMP: 4004 { 4005 int val; 4006 4007 if (optlen != sizeof(val)) 4008 return -EINVAL; 4009 if (copy_from_sockptr(&val, optval, sizeof(val))) 4010 return -EFAULT; 4011 4012 WRITE_ONCE(po->tp_tstamp, val); 4013 return 0; 4014 } 4015 case PACKET_FANOUT: 4016 { 4017 struct fanout_args args = { 0 }; 4018 4019 if (optlen != sizeof(int) && optlen != sizeof(args)) 4020 return -EINVAL; 4021 if (copy_from_sockptr(&args, optval, optlen)) 4022 return -EFAULT; 4023 4024 return fanout_add(sk, &args); 4025 } 4026 case PACKET_FANOUT_DATA: 4027 { 4028 /* Paired with the WRITE_ONCE() in fanout_add() */ 4029 if (!READ_ONCE(po->fanout)) 4030 return -EINVAL; 4031 4032 return fanout_set_data(po, optval, optlen); 4033 } 4034 case PACKET_IGNORE_OUTGOING: 4035 { 4036 int val; 4037 4038 if (optlen != sizeof(val)) 4039 return -EINVAL; 4040 if (copy_from_sockptr(&val, optval, sizeof(val))) 4041 return -EFAULT; 4042 if (val < 0 || val > 1) 4043 return -EINVAL; 4044 4045 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4046 return 0; 4047 } 4048 case PACKET_TX_HAS_OFF: 4049 { 4050 unsigned int val; 4051 4052 if (optlen != sizeof(val)) 4053 return -EINVAL; 4054 if (copy_from_sockptr(&val, optval, sizeof(val))) 4055 return -EFAULT; 4056 4057 lock_sock(sk); 4058 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4059 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4060 4061 release_sock(sk); 4062 return 0; 4063 } 4064 case PACKET_QDISC_BYPASS: 4065 { 4066 int val; 4067 4068 if (optlen != sizeof(val)) 4069 return -EINVAL; 4070 if (copy_from_sockptr(&val, optval, sizeof(val))) 4071 return -EFAULT; 4072 4073 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4074 return 0; 4075 } 4076 default: 4077 return -ENOPROTOOPT; 4078 } 4079 } 4080 4081 static int packet_getsockopt(struct socket *sock, int level, int optname, 4082 sockopt_t *opt) 4083 { 4084 int len; 4085 int val, lv = sizeof(val); 4086 struct sock *sk = sock->sk; 4087 struct packet_sock *po = pkt_sk(sk); 4088 void *data = &val; 4089 union tpacket_stats_u st; 4090 struct tpacket_rollover_stats rstats; 4091 int drops; 4092 4093 if (level != SOL_PACKET) 4094 return -ENOPROTOOPT; 4095 4096 len = opt->optlen; 4097 4098 if (len < 0) 4099 return -EINVAL; 4100 4101 switch (optname) { 4102 case PACKET_STATISTICS: 4103 spin_lock_bh(&sk->sk_receive_queue.lock); 4104 memcpy(&st, &po->stats, sizeof(st)); 4105 memset(&po->stats, 0, sizeof(po->stats)); 4106 spin_unlock_bh(&sk->sk_receive_queue.lock); 4107 drops = atomic_xchg(&po->tp_drops, 0); 4108 4109 if (po->tp_version == TPACKET_V3) { 4110 lv = sizeof(struct tpacket_stats_v3); 4111 st.stats3.tp_drops = drops; 4112 st.stats3.tp_packets += drops; 4113 data = &st.stats3; 4114 } else { 4115 lv = sizeof(struct tpacket_stats); 4116 st.stats1.tp_drops = drops; 4117 st.stats1.tp_packets += drops; 4118 data = &st.stats1; 4119 } 4120 4121 break; 4122 case PACKET_AUXDATA: 4123 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4124 break; 4125 case PACKET_ORIGDEV: 4126 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4127 break; 4128 case PACKET_VNET_HDR: 4129 val = !!READ_ONCE(po->vnet_hdr_sz); 4130 break; 4131 case PACKET_VNET_HDR_SZ: 4132 val = READ_ONCE(po->vnet_hdr_sz); 4133 break; 4134 case PACKET_COPY_THRESH: 4135 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4136 break; 4137 case PACKET_VERSION: 4138 val = po->tp_version; 4139 break; 4140 case PACKET_HDRLEN: 4141 if (len > sizeof(int)) 4142 len = sizeof(int); 4143 if (len < sizeof(int)) 4144 return -EINVAL; 4145 if (copy_from_iter(&val, len, &opt->iter_in) != len) 4146 return -EFAULT; 4147 switch (val) { 4148 case TPACKET_V1: 4149 val = sizeof(struct tpacket_hdr); 4150 break; 4151 case TPACKET_V2: 4152 val = sizeof(struct tpacket2_hdr); 4153 break; 4154 case TPACKET_V3: 4155 val = sizeof(struct tpacket3_hdr); 4156 break; 4157 default: 4158 return -EINVAL; 4159 } 4160 break; 4161 case PACKET_RESERVE: 4162 val = po->tp_reserve; 4163 break; 4164 case PACKET_LOSS: 4165 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4166 break; 4167 case PACKET_TIMESTAMP: 4168 val = READ_ONCE(po->tp_tstamp); 4169 break; 4170 case PACKET_FANOUT: 4171 val = (po->fanout ? 4172 ((u32)po->fanout->id | 4173 ((u32)po->fanout->type << 16) | 4174 ((u32)po->fanout->flags << 24)) : 4175 0); 4176 break; 4177 case PACKET_IGNORE_OUTGOING: 4178 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4179 break; 4180 case PACKET_ROLLOVER_STATS: 4181 if (!po->rollover) 4182 return -EINVAL; 4183 rstats.tp_all = atomic_long_read(&po->rollover->num); 4184 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4185 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4186 data = &rstats; 4187 lv = sizeof(rstats); 4188 break; 4189 case PACKET_TX_HAS_OFF: 4190 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4191 break; 4192 case PACKET_QDISC_BYPASS: 4193 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4194 break; 4195 default: 4196 return -ENOPROTOOPT; 4197 } 4198 4199 if (len > lv) 4200 len = lv; 4201 opt->optlen = len; 4202 if (copy_to_iter(data, len, &opt->iter_out) != len) 4203 return -EFAULT; 4204 return 0; 4205 } 4206 4207 static int packet_notifier(struct notifier_block *this, 4208 unsigned long msg, void *ptr) 4209 { 4210 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4211 struct net *net = dev_net(dev); 4212 struct packet_mclist *ml, *tmp; 4213 LIST_HEAD(mclist); 4214 struct sock *sk; 4215 4216 rcu_read_lock(); 4217 sk_for_each_rcu(sk, &net->packet.sklist) { 4218 struct packet_sock *po = pkt_sk(sk); 4219 4220 switch (msg) { 4221 case NETDEV_UNREGISTER: 4222 if (po->mclist) 4223 packet_dev_mclist_delete(dev, &po->mclist, 4224 &mclist); 4225 fallthrough; 4226 4227 case NETDEV_DOWN: 4228 if (dev->ifindex == po->ifindex) { 4229 spin_lock(&po->bind_lock); 4230 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4231 __unregister_prot_hook(sk, false); 4232 sk->sk_err = ENETDOWN; 4233 if (!sock_flag(sk, SOCK_DEAD)) 4234 sk_error_report(sk); 4235 } 4236 if (msg == NETDEV_UNREGISTER) { 4237 packet_cached_dev_reset(po); 4238 WRITE_ONCE(po->ifindex, -1); 4239 netdev_put(po->prot_hook.dev, 4240 &po->prot_hook.dev_tracker); 4241 po->prot_hook.dev = NULL; 4242 } 4243 spin_unlock(&po->bind_lock); 4244 } 4245 break; 4246 case NETDEV_UP: 4247 if (dev->ifindex == po->ifindex) { 4248 spin_lock(&po->bind_lock); 4249 if (po->num) 4250 register_prot_hook(sk); 4251 spin_unlock(&po->bind_lock); 4252 } 4253 break; 4254 } 4255 } 4256 rcu_read_unlock(); 4257 4258 /* packet_dev_mc might grab instance locks so can't run under rcu */ 4259 list_for_each_entry_safe(ml, tmp, &mclist, remove_list) { 4260 packet_dev_mc(dev, ml, -1); 4261 kfree(ml); 4262 } 4263 4264 return NOTIFY_DONE; 4265 } 4266 4267 4268 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4269 unsigned long arg) 4270 { 4271 struct sock *sk = sock->sk; 4272 4273 switch (cmd) { 4274 case SIOCOUTQ: 4275 { 4276 int amount = sk_wmem_alloc_get(sk); 4277 4278 return put_user(amount, (int __user *)arg); 4279 } 4280 case SIOCINQ: 4281 { 4282 struct sk_buff *skb; 4283 int amount = 0; 4284 4285 spin_lock_bh(&sk->sk_receive_queue.lock); 4286 skb = skb_peek(&sk->sk_receive_queue); 4287 if (skb) 4288 amount = skb->len; 4289 spin_unlock_bh(&sk->sk_receive_queue.lock); 4290 return put_user(amount, (int __user *)arg); 4291 } 4292 #ifdef CONFIG_INET 4293 case SIOCADDRT: 4294 case SIOCDELRT: 4295 case SIOCDARP: 4296 case SIOCGARP: 4297 case SIOCSARP: 4298 case SIOCGIFADDR: 4299 case SIOCSIFADDR: 4300 case SIOCGIFBRDADDR: 4301 case SIOCSIFBRDADDR: 4302 case SIOCGIFNETMASK: 4303 case SIOCSIFNETMASK: 4304 case SIOCGIFDSTADDR: 4305 case SIOCSIFDSTADDR: 4306 case SIOCSIFFLAGS: 4307 return inet_dgram_ops.ioctl(sock, cmd, arg); 4308 #endif 4309 4310 default: 4311 return -ENOIOCTLCMD; 4312 } 4313 return 0; 4314 } 4315 4316 static __poll_t packet_poll(struct file *file, struct socket *sock, 4317 poll_table *wait) 4318 { 4319 struct sock *sk = sock->sk; 4320 struct packet_sock *po = pkt_sk(sk); 4321 __poll_t mask = datagram_poll(file, sock, wait); 4322 4323 spin_lock_bh(&sk->sk_receive_queue.lock); 4324 if (po->rx_ring.pg_vec) { 4325 if (!packet_previous_rx_frame(po, &po->rx_ring, 4326 TP_STATUS_KERNEL)) 4327 mask |= EPOLLIN | EPOLLRDNORM; 4328 } 4329 __packet_rcv_try_clear_pressure(po); 4330 spin_unlock_bh(&sk->sk_receive_queue.lock); 4331 spin_lock_bh(&sk->sk_write_queue.lock); 4332 if (po->tx_ring.pg_vec) { 4333 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4334 mask |= EPOLLOUT | EPOLLWRNORM; 4335 } 4336 spin_unlock_bh(&sk->sk_write_queue.lock); 4337 return mask; 4338 } 4339 4340 4341 /* Dirty? Well, I still did not learn better way to account 4342 * for user mmaps. 4343 */ 4344 4345 static void packet_mm_open(struct vm_area_struct *vma) 4346 { 4347 struct file *file = vma->vm_file; 4348 struct socket *sock = file->private_data; 4349 struct sock *sk = sock->sk; 4350 4351 if (sk) 4352 atomic_long_inc(&pkt_sk(sk)->mapped); 4353 } 4354 4355 static void packet_mm_close(struct vm_area_struct *vma) 4356 { 4357 struct file *file = vma->vm_file; 4358 struct socket *sock = file->private_data; 4359 struct sock *sk = sock->sk; 4360 4361 if (sk) 4362 atomic_long_dec(&pkt_sk(sk)->mapped); 4363 } 4364 4365 static const struct vm_operations_struct packet_mmap_ops = { 4366 .open = packet_mm_open, 4367 .close = packet_mm_close, 4368 }; 4369 4370 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4371 unsigned int len) 4372 { 4373 int i; 4374 4375 for (i = 0; i < len; i++) { 4376 if (likely(pg_vec[i].buffer)) { 4377 if (is_vmalloc_addr(pg_vec[i].buffer)) 4378 vfree(pg_vec[i].buffer); 4379 else 4380 free_pages((unsigned long)pg_vec[i].buffer, 4381 order); 4382 pg_vec[i].buffer = NULL; 4383 } 4384 } 4385 kfree(pg_vec); 4386 } 4387 4388 static char *alloc_one_pg_vec_page(unsigned long order) 4389 { 4390 char *buffer; 4391 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4392 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4393 4394 buffer = (char *) __get_free_pages(gfp_flags, order); 4395 if (buffer) 4396 return buffer; 4397 4398 /* __get_free_pages failed, fall back to vmalloc */ 4399 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4400 if (buffer) 4401 return buffer; 4402 4403 /* vmalloc failed, lets dig into swap here */ 4404 gfp_flags &= ~__GFP_NORETRY; 4405 buffer = (char *) __get_free_pages(gfp_flags, order); 4406 if (buffer) 4407 return buffer; 4408 4409 /* complete and utter failure */ 4410 return NULL; 4411 } 4412 4413 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4414 { 4415 unsigned int block_nr = req->tp_block_nr; 4416 struct pgv *pg_vec; 4417 int i; 4418 4419 pg_vec = kzalloc_objs(struct pgv, block_nr, GFP_KERNEL | __GFP_NOWARN); 4420 if (unlikely(!pg_vec)) 4421 goto out; 4422 4423 for (i = 0; i < block_nr; i++) { 4424 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4425 if (unlikely(!pg_vec[i].buffer)) 4426 goto out_free_pgvec; 4427 } 4428 4429 out: 4430 return pg_vec; 4431 4432 out_free_pgvec: 4433 free_pg_vec(pg_vec, order, block_nr); 4434 pg_vec = NULL; 4435 goto out; 4436 } 4437 4438 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4439 int closing, int tx_ring) 4440 { 4441 struct pgv *pg_vec = NULL; 4442 struct packet_sock *po = pkt_sk(sk); 4443 unsigned long *rx_owner_map = NULL; 4444 int was_running, order = 0; 4445 struct packet_ring_buffer *rb; 4446 struct sk_buff_head *rb_queue; 4447 __be16 num; 4448 int err; 4449 /* Added to avoid minimal code churn */ 4450 struct tpacket_req *req = &req_u->req; 4451 4452 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4453 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4454 4455 err = -EBUSY; 4456 if (!closing) { 4457 if (atomic_long_read(&po->mapped)) 4458 goto out; 4459 if (packet_read_pending(rb)) 4460 goto out; 4461 } 4462 4463 if (req->tp_block_nr) { 4464 unsigned int min_frame_size; 4465 4466 /* Sanity tests and some calculations */ 4467 err = -EBUSY; 4468 if (unlikely(rb->pg_vec)) 4469 goto out; 4470 4471 switch (po->tp_version) { 4472 case TPACKET_V1: 4473 po->tp_hdrlen = TPACKET_HDRLEN; 4474 break; 4475 case TPACKET_V2: 4476 po->tp_hdrlen = TPACKET2_HDRLEN; 4477 break; 4478 case TPACKET_V3: 4479 po->tp_hdrlen = TPACKET3_HDRLEN; 4480 break; 4481 } 4482 4483 err = -EINVAL; 4484 if (unlikely((int)req->tp_block_size <= 0)) 4485 goto out; 4486 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4487 goto out; 4488 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4489 if (po->tp_version >= TPACKET_V3 && 4490 req->tp_block_size < 4491 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4492 goto out; 4493 if (unlikely(req->tp_frame_size < min_frame_size)) 4494 goto out; 4495 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4496 goto out; 4497 4498 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4499 if (unlikely(rb->frames_per_block == 0)) 4500 goto out; 4501 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4502 goto out; 4503 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4504 req->tp_frame_nr)) 4505 goto out; 4506 4507 err = -ENOMEM; 4508 order = get_order(req->tp_block_size); 4509 pg_vec = alloc_pg_vec(req, order); 4510 if (unlikely(!pg_vec)) 4511 goto out; 4512 switch (po->tp_version) { 4513 case TPACKET_V3: 4514 /* Block transmit is not supported yet */ 4515 if (!tx_ring) { 4516 init_prb_bdqc(po, rb, pg_vec, req_u); 4517 } else { 4518 struct tpacket_req3 *req3 = &req_u->req3; 4519 4520 if (req3->tp_retire_blk_tov || 4521 req3->tp_sizeof_priv || 4522 req3->tp_feature_req_word) { 4523 err = -EINVAL; 4524 goto out_free_pg_vec; 4525 } 4526 } 4527 break; 4528 default: 4529 if (!tx_ring) { 4530 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4531 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4532 if (!rx_owner_map) 4533 goto out_free_pg_vec; 4534 } 4535 break; 4536 } 4537 } 4538 /* Done */ 4539 else { 4540 err = -EINVAL; 4541 if (unlikely(req->tp_frame_nr)) 4542 goto out; 4543 } 4544 4545 4546 /* Detach socket from network */ 4547 spin_lock(&po->bind_lock); 4548 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4549 num = po->num; 4550 WRITE_ONCE(po->num, 0); 4551 if (was_running) 4552 __unregister_prot_hook(sk, false); 4553 4554 spin_unlock(&po->bind_lock); 4555 4556 synchronize_net(); 4557 4558 err = -EBUSY; 4559 mutex_lock(&po->pg_vec_lock); 4560 if (closing || atomic_long_read(&po->mapped) == 0) { 4561 err = 0; 4562 spin_lock_bh(&rb_queue->lock); 4563 swap(rb->pg_vec, pg_vec); 4564 if (po->tp_version <= TPACKET_V2) 4565 swap(rb->rx_owner_map, rx_owner_map); 4566 rb->frame_max = (req->tp_frame_nr - 1); 4567 rb->head = 0; 4568 rb->frame_size = req->tp_frame_size; 4569 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4570 tpacket_rcv : packet_rcv; 4571 spin_unlock_bh(&rb_queue->lock); 4572 4573 swap(rb->pg_vec_order, order); 4574 swap(rb->pg_vec_len, req->tp_block_nr); 4575 4576 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4577 skb_queue_purge(rb_queue); 4578 if (atomic_long_read(&po->mapped)) 4579 pr_err("packet_mmap: vma is busy: %ld\n", 4580 atomic_long_read(&po->mapped)); 4581 } 4582 mutex_unlock(&po->pg_vec_lock); 4583 4584 spin_lock(&po->bind_lock); 4585 WRITE_ONCE(po->num, num); 4586 /* 4587 * NETDEV_UNREGISTER may have invalidated the binding while bind_lock 4588 * was dropped above. Do not re-add a fanout hook to a dead device. 4589 */ 4590 if (was_running && READ_ONCE(po->ifindex) != -1) 4591 register_prot_hook(sk); 4592 4593 spin_unlock(&po->bind_lock); 4594 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4595 /* Because we don't support block-based V3 on tx-ring */ 4596 if (!tx_ring) 4597 prb_shutdown_retire_blk_timer(po, rb_queue); 4598 } 4599 4600 out_free_pg_vec: 4601 if (pg_vec) { 4602 bitmap_free(rx_owner_map); 4603 free_pg_vec(pg_vec, order, req->tp_block_nr); 4604 } 4605 out: 4606 return err; 4607 } 4608 4609 static int packet_mmap(struct file *file, struct socket *sock, 4610 struct vm_area_struct *vma) 4611 { 4612 struct sock *sk = sock->sk; 4613 struct packet_sock *po = pkt_sk(sk); 4614 unsigned long size, expected_size; 4615 struct packet_ring_buffer *rb; 4616 unsigned long start; 4617 int err = -EINVAL; 4618 int i; 4619 4620 if (vma->vm_pgoff) 4621 return -EINVAL; 4622 4623 mutex_lock(&po->pg_vec_lock); 4624 4625 expected_size = 0; 4626 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4627 if (rb->pg_vec) { 4628 expected_size += rb->pg_vec_len 4629 * rb->pg_vec_pages 4630 * PAGE_SIZE; 4631 } 4632 } 4633 4634 if (expected_size == 0) 4635 goto out; 4636 4637 size = vma->vm_end - vma->vm_start; 4638 if (size != expected_size) 4639 goto out; 4640 4641 start = vma->vm_start; 4642 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4643 if (rb->pg_vec == NULL) 4644 continue; 4645 4646 for (i = 0; i < rb->pg_vec_len; i++) { 4647 struct page *page; 4648 void *kaddr = rb->pg_vec[i].buffer; 4649 int pg_num; 4650 4651 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4652 page = pgv_to_page(kaddr); 4653 err = vm_insert_page(vma, start, page); 4654 if (unlikely(err)) 4655 goto out; 4656 start += PAGE_SIZE; 4657 kaddr += PAGE_SIZE; 4658 } 4659 } 4660 } 4661 4662 atomic_long_inc(&po->mapped); 4663 vma->vm_ops = &packet_mmap_ops; 4664 err = 0; 4665 4666 out: 4667 mutex_unlock(&po->pg_vec_lock); 4668 return err; 4669 } 4670 4671 static const struct proto_ops packet_ops_spkt = { 4672 .family = PF_PACKET, 4673 .owner = THIS_MODULE, 4674 .release = packet_release, 4675 .bind = packet_bind_spkt, 4676 .connect = sock_no_connect, 4677 .socketpair = sock_no_socketpair, 4678 .accept = sock_no_accept, 4679 .getname = packet_getname_spkt, 4680 .poll = datagram_poll, 4681 .ioctl = packet_ioctl, 4682 .gettstamp = sock_gettstamp, 4683 .listen = sock_no_listen, 4684 .shutdown = sock_no_shutdown, 4685 .sendmsg = packet_sendmsg_spkt, 4686 .recvmsg = packet_recvmsg, 4687 .mmap = sock_no_mmap, 4688 }; 4689 4690 static const struct proto_ops packet_ops = { 4691 .family = PF_PACKET, 4692 .owner = THIS_MODULE, 4693 .release = packet_release, 4694 .bind = packet_bind, 4695 .connect = sock_no_connect, 4696 .socketpair = sock_no_socketpair, 4697 .accept = sock_no_accept, 4698 .getname = packet_getname, 4699 .poll = packet_poll, 4700 .ioctl = packet_ioctl, 4701 .gettstamp = sock_gettstamp, 4702 .listen = sock_no_listen, 4703 .shutdown = sock_no_shutdown, 4704 .setsockopt = packet_setsockopt, 4705 .getsockopt_iter = packet_getsockopt, 4706 .sendmsg = packet_sendmsg, 4707 .recvmsg = packet_recvmsg, 4708 .mmap = packet_mmap, 4709 }; 4710 4711 static const struct net_proto_family packet_family_ops = { 4712 .family = PF_PACKET, 4713 .create = packet_create, 4714 .owner = THIS_MODULE, 4715 }; 4716 4717 static struct notifier_block packet_netdev_notifier = { 4718 .notifier_call = packet_notifier, 4719 }; 4720 4721 #ifdef CONFIG_PROC_FS 4722 4723 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4724 __acquires(RCU) 4725 { 4726 struct net *net = seq_file_net(seq); 4727 4728 rcu_read_lock(); 4729 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4730 } 4731 4732 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4733 { 4734 struct net *net = seq_file_net(seq); 4735 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4736 } 4737 4738 static void packet_seq_stop(struct seq_file *seq, void *v) 4739 __releases(RCU) 4740 { 4741 rcu_read_unlock(); 4742 } 4743 4744 static int packet_seq_show(struct seq_file *seq, void *v) 4745 { 4746 if (v == SEQ_START_TOKEN) 4747 seq_printf(seq, 4748 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4749 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4750 else { 4751 struct sock *s = sk_entry(v); 4752 const struct packet_sock *po = pkt_sk(s); 4753 4754 seq_printf(seq, 4755 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6llu\n", 4756 s, 4757 refcount_read(&s->sk_refcnt), 4758 s->sk_type, 4759 ntohs(READ_ONCE(po->num)), 4760 READ_ONCE(po->ifindex), 4761 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4762 atomic_read(&s->sk_rmem_alloc), 4763 from_kuid_munged(seq_user_ns(seq), sk_uid(s)), 4764 sock_i_ino(s)); 4765 } 4766 4767 return 0; 4768 } 4769 4770 static const struct seq_operations packet_seq_ops = { 4771 .start = packet_seq_start, 4772 .next = packet_seq_next, 4773 .stop = packet_seq_stop, 4774 .show = packet_seq_show, 4775 }; 4776 #endif 4777 4778 static int __net_init packet_net_init(struct net *net) 4779 { 4780 mutex_init(&net->packet.sklist_lock); 4781 INIT_HLIST_HEAD(&net->packet.sklist); 4782 4783 #ifdef CONFIG_PROC_FS 4784 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4785 sizeof(struct seq_net_private))) 4786 return -ENOMEM; 4787 #endif /* CONFIG_PROC_FS */ 4788 4789 return 0; 4790 } 4791 4792 static void __net_exit packet_net_exit(struct net *net) 4793 { 4794 remove_proc_entry("packet", net->proc_net); 4795 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4796 } 4797 4798 static struct pernet_operations packet_net_ops = { 4799 .init = packet_net_init, 4800 .exit = packet_net_exit, 4801 }; 4802 4803 4804 static void __exit packet_exit(void) 4805 { 4806 sock_unregister(PF_PACKET); 4807 proto_unregister(&packet_proto); 4808 unregister_netdevice_notifier(&packet_netdev_notifier); 4809 unregister_pernet_subsys(&packet_net_ops); 4810 } 4811 4812 static int __init packet_init(void) 4813 { 4814 int rc; 4815 4816 rc = register_pernet_subsys(&packet_net_ops); 4817 if (rc) 4818 goto out; 4819 rc = register_netdevice_notifier(&packet_netdev_notifier); 4820 if (rc) 4821 goto out_pernet; 4822 rc = proto_register(&packet_proto, 0); 4823 if (rc) 4824 goto out_notifier; 4825 rc = sock_register(&packet_family_ops); 4826 if (rc) 4827 goto out_proto; 4828 4829 return 0; 4830 4831 out_proto: 4832 proto_unregister(&packet_proto); 4833 out_notifier: 4834 unregister_netdevice_notifier(&packet_netdev_notifier); 4835 out_pernet: 4836 unregister_pernet_subsys(&packet_net_ops); 4837 out: 4838 return rc; 4839 } 4840 4841 module_init(packet_init); 4842 module_exit(packet_exit); 4843 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4844 MODULE_LICENSE("GPL"); 4845 MODULE_ALIAS_NETPROTO(PF_PACKET); 4846