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_sock_destruct(struct sock *sk) 1326 { 1327 skb_queue_purge(&sk->sk_error_queue); 1328 1329 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1330 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1331 1332 if (!sock_flag(sk, SOCK_DEAD)) { 1333 pr_err("Attempt to release alive packet socket: %p\n", sk); 1334 return; 1335 } 1336 } 1337 1338 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1339 { 1340 u32 *history = po->rollover->history; 1341 u32 victim, rxhash; 1342 int i, count = 0; 1343 1344 rxhash = skb_get_hash(skb); 1345 for (i = 0; i < ROLLOVER_HLEN; i++) 1346 if (READ_ONCE(history[i]) == rxhash) 1347 count++; 1348 1349 victim = get_random_u32_below(ROLLOVER_HLEN); 1350 1351 /* Avoid dirtying the cache line if possible */ 1352 if (READ_ONCE(history[victim]) != rxhash) 1353 WRITE_ONCE(history[victim], rxhash); 1354 1355 return count > (ROLLOVER_HLEN >> 1); 1356 } 1357 1358 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1359 struct sk_buff *skb, 1360 unsigned int num) 1361 { 1362 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1363 } 1364 1365 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1366 struct sk_buff *skb, 1367 unsigned int num) 1368 { 1369 unsigned int val = atomic_inc_return(&f->rr_cur); 1370 1371 return val % num; 1372 } 1373 1374 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1375 struct sk_buff *skb, 1376 unsigned int num) 1377 { 1378 return smp_processor_id() % num; 1379 } 1380 1381 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1382 struct sk_buff *skb, 1383 unsigned int num) 1384 { 1385 return get_random_u32_below(num); 1386 } 1387 1388 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1389 struct sk_buff *skb, 1390 unsigned int idx, bool try_self, 1391 unsigned int num) 1392 { 1393 struct packet_sock *po, *po_next, *po_skip = NULL; 1394 unsigned int i, j, room = ROOM_NONE; 1395 1396 po = pkt_sk(rcu_dereference(f->arr[idx])); 1397 1398 if (try_self) { 1399 room = packet_rcv_has_room(po, skb); 1400 if (room == ROOM_NORMAL || 1401 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1402 return idx; 1403 po_skip = po; 1404 } 1405 1406 i = j = min_t(int, po->rollover->sock, num - 1); 1407 do { 1408 po_next = pkt_sk(rcu_dereference(f->arr[i])); 1409 if (po_next != po_skip && 1410 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) && 1411 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1412 if (i != j) 1413 po->rollover->sock = i; 1414 atomic_long_inc(&po->rollover->num); 1415 if (room == ROOM_LOW) 1416 atomic_long_inc(&po->rollover->num_huge); 1417 return i; 1418 } 1419 1420 if (++i == num) 1421 i = 0; 1422 } while (i != j); 1423 1424 atomic_long_inc(&po->rollover->num_failed); 1425 return idx; 1426 } 1427 1428 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1429 struct sk_buff *skb, 1430 unsigned int num) 1431 { 1432 return skb_get_queue_mapping(skb) % num; 1433 } 1434 1435 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1436 struct sk_buff *skb, 1437 unsigned int num) 1438 { 1439 struct bpf_prog *prog; 1440 unsigned int ret = 0; 1441 1442 rcu_read_lock(); 1443 prog = rcu_dereference(f->bpf_prog); 1444 if (prog) 1445 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1446 rcu_read_unlock(); 1447 1448 return ret; 1449 } 1450 1451 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1452 { 1453 return f->flags & (flag >> 8); 1454 } 1455 1456 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1457 struct packet_type *pt, struct net_device *orig_dev) 1458 { 1459 struct packet_fanout *f = pt->af_packet_priv; 1460 unsigned int num = READ_ONCE(f->num_members); 1461 struct net *net = read_pnet(&f->net); 1462 struct packet_sock *po; 1463 unsigned int idx; 1464 1465 if (!net_eq(dev_net(dev), net) || !num) { 1466 kfree_skb(skb); 1467 return 0; 1468 } 1469 1470 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1471 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1472 if (!skb) 1473 return 0; 1474 } 1475 switch (f->type) { 1476 case PACKET_FANOUT_HASH: 1477 default: 1478 idx = fanout_demux_hash(f, skb, num); 1479 break; 1480 case PACKET_FANOUT_LB: 1481 idx = fanout_demux_lb(f, skb, num); 1482 break; 1483 case PACKET_FANOUT_CPU: 1484 idx = fanout_demux_cpu(f, skb, num); 1485 break; 1486 case PACKET_FANOUT_RND: 1487 idx = fanout_demux_rnd(f, skb, num); 1488 break; 1489 case PACKET_FANOUT_QM: 1490 idx = fanout_demux_qm(f, skb, num); 1491 break; 1492 case PACKET_FANOUT_ROLLOVER: 1493 idx = fanout_demux_rollover(f, skb, 0, false, num); 1494 break; 1495 case PACKET_FANOUT_CBPF: 1496 case PACKET_FANOUT_EBPF: 1497 idx = fanout_demux_bpf(f, skb, num); 1498 break; 1499 } 1500 1501 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1502 idx = fanout_demux_rollover(f, skb, idx, true, num); 1503 1504 po = pkt_sk(rcu_dereference(f->arr[idx])); 1505 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1506 } 1507 1508 DEFINE_MUTEX(fanout_mutex); 1509 EXPORT_SYMBOL_GPL(fanout_mutex); 1510 static LIST_HEAD(fanout_list); 1511 static u16 fanout_next_id; 1512 1513 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1514 { 1515 struct packet_fanout *f = po->fanout; 1516 1517 spin_lock(&f->lock); 1518 rcu_assign_pointer(f->arr[f->num_members], sk); 1519 smp_wmb(); 1520 f->num_members++; 1521 if (f->num_members == 1) 1522 dev_add_pack(&f->prot_hook); 1523 spin_unlock(&f->lock); 1524 } 1525 1526 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1527 { 1528 struct packet_fanout *f = po->fanout; 1529 int i; 1530 1531 spin_lock(&f->lock); 1532 for (i = 0; i < f->num_members; i++) { 1533 if (rcu_dereference_protected(f->arr[i], 1534 lockdep_is_held(&f->lock)) == sk) 1535 break; 1536 } 1537 BUG_ON(i >= f->num_members); 1538 rcu_assign_pointer(f->arr[i], 1539 rcu_dereference_protected(f->arr[f->num_members - 1], 1540 lockdep_is_held(&f->lock))); 1541 f->num_members--; 1542 if (f->num_members == 0) 1543 __dev_remove_pack(&f->prot_hook); 1544 spin_unlock(&f->lock); 1545 } 1546 1547 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1548 { 1549 if (sk->sk_family != PF_PACKET) 1550 return false; 1551 1552 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1553 } 1554 1555 static void fanout_init_data(struct packet_fanout *f) 1556 { 1557 switch (f->type) { 1558 case PACKET_FANOUT_LB: 1559 atomic_set(&f->rr_cur, 0); 1560 break; 1561 case PACKET_FANOUT_CBPF: 1562 case PACKET_FANOUT_EBPF: 1563 RCU_INIT_POINTER(f->bpf_prog, NULL); 1564 break; 1565 } 1566 } 1567 1568 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1569 { 1570 struct bpf_prog *old; 1571 1572 spin_lock(&f->lock); 1573 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1574 rcu_assign_pointer(f->bpf_prog, new); 1575 spin_unlock(&f->lock); 1576 1577 if (old) { 1578 synchronize_net(); 1579 bpf_prog_destroy(old); 1580 } 1581 } 1582 1583 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, 1584 unsigned int len) 1585 { 1586 struct bpf_prog *new; 1587 struct sock_fprog fprog; 1588 int ret; 1589 1590 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1591 return -EPERM; 1592 1593 ret = copy_bpf_fprog_from_user(&fprog, data, len); 1594 if (ret) 1595 return ret; 1596 1597 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1598 if (ret) 1599 return ret; 1600 1601 __fanout_set_data_bpf(po->fanout, new); 1602 return 0; 1603 } 1604 1605 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, 1606 unsigned int len) 1607 { 1608 struct bpf_prog *new; 1609 u32 fd; 1610 1611 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1612 return -EPERM; 1613 if (len != sizeof(fd)) 1614 return -EINVAL; 1615 if (copy_from_sockptr(&fd, data, len)) 1616 return -EFAULT; 1617 1618 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1619 if (IS_ERR(new)) 1620 return PTR_ERR(new); 1621 1622 __fanout_set_data_bpf(po->fanout, new); 1623 return 0; 1624 } 1625 1626 static int fanout_set_data(struct packet_sock *po, sockptr_t data, 1627 unsigned int len) 1628 { 1629 switch (po->fanout->type) { 1630 case PACKET_FANOUT_CBPF: 1631 return fanout_set_data_cbpf(po, data, len); 1632 case PACKET_FANOUT_EBPF: 1633 return fanout_set_data_ebpf(po, data, len); 1634 default: 1635 return -EINVAL; 1636 } 1637 } 1638 1639 static void fanout_release_data(struct packet_fanout *f) 1640 { 1641 switch (f->type) { 1642 case PACKET_FANOUT_CBPF: 1643 case PACKET_FANOUT_EBPF: 1644 __fanout_set_data_bpf(f, NULL); 1645 } 1646 } 1647 1648 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1649 { 1650 struct packet_fanout *f; 1651 1652 list_for_each_entry(f, &fanout_list, list) { 1653 if (f->id == candidate_id && 1654 read_pnet(&f->net) == sock_net(sk)) { 1655 return false; 1656 } 1657 } 1658 return true; 1659 } 1660 1661 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1662 { 1663 u16 id = fanout_next_id; 1664 1665 do { 1666 if (__fanout_id_is_free(sk, id)) { 1667 *new_id = id; 1668 fanout_next_id = id + 1; 1669 return true; 1670 } 1671 1672 id++; 1673 } while (id != fanout_next_id); 1674 1675 return false; 1676 } 1677 1678 static int fanout_add(struct sock *sk, struct fanout_args *args) 1679 { 1680 struct packet_rollover *rollover = NULL; 1681 struct packet_sock *po = pkt_sk(sk); 1682 u16 type_flags = args->type_flags; 1683 struct packet_fanout *f, *match; 1684 u8 type = type_flags & 0xff; 1685 u8 flags = type_flags >> 8; 1686 u16 id = args->id; 1687 int err; 1688 1689 switch (type) { 1690 case PACKET_FANOUT_ROLLOVER: 1691 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1692 return -EINVAL; 1693 break; 1694 case PACKET_FANOUT_HASH: 1695 case PACKET_FANOUT_LB: 1696 case PACKET_FANOUT_CPU: 1697 case PACKET_FANOUT_RND: 1698 case PACKET_FANOUT_QM: 1699 case PACKET_FANOUT_CBPF: 1700 case PACKET_FANOUT_EBPF: 1701 break; 1702 default: 1703 return -EINVAL; 1704 } 1705 1706 mutex_lock(&fanout_mutex); 1707 1708 err = -EALREADY; 1709 if (po->fanout) 1710 goto out; 1711 1712 if (type == PACKET_FANOUT_ROLLOVER || 1713 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1714 err = -ENOMEM; 1715 rollover = kzalloc_obj(*rollover); 1716 if (!rollover) 1717 goto out; 1718 atomic_long_set(&rollover->num, 0); 1719 atomic_long_set(&rollover->num_huge, 0); 1720 atomic_long_set(&rollover->num_failed, 0); 1721 } 1722 1723 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1724 if (id != 0) { 1725 err = -EINVAL; 1726 goto out; 1727 } 1728 if (!fanout_find_new_id(sk, &id)) { 1729 err = -ENOMEM; 1730 goto out; 1731 } 1732 /* ephemeral flag for the first socket in the group: drop it */ 1733 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1734 } 1735 1736 match = NULL; 1737 list_for_each_entry(f, &fanout_list, list) { 1738 if (f->id == id && 1739 read_pnet(&f->net) == sock_net(sk)) { 1740 match = f; 1741 break; 1742 } 1743 } 1744 err = -EINVAL; 1745 if (match) { 1746 if (match->flags != flags) 1747 goto out; 1748 if (args->max_num_members && 1749 args->max_num_members != match->max_num_members) 1750 goto out; 1751 } else { 1752 if (args->max_num_members > PACKET_FANOUT_MAX) 1753 goto out; 1754 if (!args->max_num_members) 1755 /* legacy PACKET_FANOUT_MAX */ 1756 args->max_num_members = 256; 1757 err = -ENOMEM; 1758 match = kvzalloc_flex(*match, arr, args->max_num_members); 1759 if (!match) 1760 goto out; 1761 write_pnet(&match->net, sock_net(sk)); 1762 match->id = id; 1763 match->type = type; 1764 match->flags = flags; 1765 INIT_LIST_HEAD(&match->list); 1766 spin_lock_init(&match->lock); 1767 refcount_set(&match->sk_ref, 0); 1768 fanout_init_data(match); 1769 match->prot_hook.type = po->prot_hook.type; 1770 match->prot_hook.dev = po->prot_hook.dev; 1771 match->prot_hook.func = packet_rcv_fanout; 1772 match->prot_hook.af_packet_priv = match; 1773 match->prot_hook.af_packet_net = read_pnet(&match->net); 1774 match->prot_hook.id_match = match_fanout_group; 1775 match->max_num_members = args->max_num_members; 1776 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; 1777 list_add(&match->list, &fanout_list); 1778 } 1779 err = -EINVAL; 1780 1781 spin_lock(&po->bind_lock); 1782 if (po->num && 1783 match->type == type && 1784 match->prot_hook.type == po->prot_hook.type && 1785 match->prot_hook.dev == po->prot_hook.dev) { 1786 err = -ENOSPC; 1787 if (refcount_read(&match->sk_ref) < match->max_num_members) { 1788 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1789 WRITE_ONCE(po->fanout, match); 1790 1791 po->rollover = rollover; 1792 rollover = NULL; 1793 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1794 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 1795 __dev_remove_pack(&po->prot_hook); 1796 __fanout_link(sk, po); 1797 } 1798 err = 0; 1799 } 1800 } 1801 spin_unlock(&po->bind_lock); 1802 1803 if (err && !refcount_read(&match->sk_ref)) { 1804 list_del(&match->list); 1805 kvfree(match); 1806 } 1807 1808 out: 1809 kfree(rollover); 1810 mutex_unlock(&fanout_mutex); 1811 return err; 1812 } 1813 1814 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1815 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1816 * It is the responsibility of the caller to call fanout_release_data() and 1817 * free the returned packet_fanout (after synchronize_net()) 1818 */ 1819 static struct packet_fanout *fanout_release(struct sock *sk) 1820 { 1821 struct packet_sock *po = pkt_sk(sk); 1822 struct packet_fanout *f; 1823 1824 mutex_lock(&fanout_mutex); 1825 f = po->fanout; 1826 if (f) { 1827 po->fanout = NULL; 1828 1829 if (refcount_dec_and_test(&f->sk_ref)) 1830 list_del(&f->list); 1831 else 1832 f = NULL; 1833 } 1834 mutex_unlock(&fanout_mutex); 1835 1836 return f; 1837 } 1838 1839 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1840 struct sk_buff *skb) 1841 { 1842 /* Earlier code assumed this would be a VLAN pkt, double-check 1843 * this now that we have the actual packet in hand. We can only 1844 * do this check on Ethernet devices. 1845 */ 1846 if (unlikely(dev->type != ARPHRD_ETHER)) 1847 return false; 1848 1849 skb_reset_mac_header(skb); 1850 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1851 } 1852 1853 static const struct proto_ops packet_ops; 1854 1855 static const struct proto_ops packet_ops_spkt; 1856 1857 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1858 struct packet_type *pt, struct net_device *orig_dev) 1859 { 1860 struct sock *sk; 1861 struct sockaddr_pkt *spkt; 1862 1863 /* 1864 * When we registered the protocol we saved the socket in the data 1865 * field for just this event. 1866 */ 1867 1868 sk = pt->af_packet_priv; 1869 1870 /* 1871 * Yank back the headers [hope the device set this 1872 * right or kerboom...] 1873 * 1874 * Incoming packets have ll header pulled, 1875 * push it back. 1876 * 1877 * For outgoing ones skb->data == skb_mac_header(skb) 1878 * so that this procedure is noop. 1879 */ 1880 1881 if (skb->pkt_type == PACKET_LOOPBACK) 1882 goto out; 1883 1884 if (!net_eq(dev_net(dev), sock_net(sk))) 1885 goto out; 1886 1887 skb = skb_share_check(skb, GFP_ATOMIC); 1888 if (skb == NULL) 1889 goto oom; 1890 1891 /* drop any routing info */ 1892 skb_dst_drop(skb); 1893 1894 /* drop conntrack reference */ 1895 nf_reset_ct(skb); 1896 1897 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1898 1899 skb_push(skb, skb->data - skb_mac_header(skb)); 1900 1901 /* 1902 * The SOCK_PACKET socket receives _all_ frames. 1903 */ 1904 1905 spkt->spkt_family = dev->type; 1906 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1907 spkt->spkt_protocol = skb->protocol; 1908 1909 /* 1910 * Charge the memory to the socket. This is done specifically 1911 * to prevent sockets using all the memory up. 1912 */ 1913 1914 if (sock_queue_rcv_skb(sk, skb) == 0) 1915 return 0; 1916 1917 out: 1918 kfree_skb(skb); 1919 oom: 1920 return 0; 1921 } 1922 1923 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1924 { 1925 int depth; 1926 1927 /* On TX skb->data is the L2 header; anchor it for all socket types. */ 1928 skb_reset_mac_header(skb); 1929 1930 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1931 sock->type == SOCK_RAW) 1932 skb->protocol = dev_parse_header_protocol(skb); 1933 1934 /* Move network header to the right position for VLAN tagged packets */ 1935 if (likely(skb->dev->type == ARPHRD_ETHER) && 1936 eth_type_vlan(skb->protocol) && 1937 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 1938 skb_set_network_header(skb, depth); 1939 1940 skb_probe_transport_header(skb); 1941 } 1942 1943 /* 1944 * Output a raw packet to a device layer. This bypasses all the other 1945 * protocol layers and you must therefore supply it with a complete frame 1946 */ 1947 1948 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1949 size_t len) 1950 { 1951 struct sock *sk = sock->sk; 1952 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1953 struct sk_buff *skb = NULL; 1954 struct net_device *dev; 1955 struct sockcm_cookie sockc; 1956 __be16 proto = 0; 1957 int err; 1958 int extra_len = 0; 1959 1960 /* 1961 * Get and verify the address. 1962 */ 1963 1964 if (saddr) { 1965 if (msg->msg_namelen < sizeof(struct sockaddr)) 1966 return -EINVAL; 1967 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1968 proto = saddr->spkt_protocol; 1969 } else 1970 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1971 1972 /* 1973 * Find the device first to size check it 1974 */ 1975 1976 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1977 retry: 1978 rcu_read_lock(); 1979 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1980 err = -ENODEV; 1981 if (dev == NULL) 1982 goto out_unlock; 1983 1984 err = -ENETDOWN; 1985 if (!(dev->flags & IFF_UP)) 1986 goto out_unlock; 1987 1988 /* 1989 * You may not queue a frame bigger than the mtu. This is the lowest level 1990 * raw protocol and you must do your own fragmentation at this level. 1991 */ 1992 1993 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1994 if (!netif_supports_nofcs(dev)) { 1995 err = -EPROTONOSUPPORT; 1996 goto out_unlock; 1997 } 1998 extra_len = 4; /* We're doing our own CRC */ 1999 } 2000 2001 err = -EMSGSIZE; 2002 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 2003 goto out_unlock; 2004 2005 if (!skb) { 2006 size_t reserved = LL_RESERVED_SPACE(dev); 2007 int tlen = dev->needed_tailroom; 2008 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 2009 2010 rcu_read_unlock(); 2011 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2012 if (skb == NULL) 2013 return -ENOBUFS; 2014 /* FIXME: Save some space for broken drivers that write a hard 2015 * header at transmission time by themselves. PPP is the notable 2016 * one here. This should really be fixed at the driver level. 2017 */ 2018 skb_reserve(skb, reserved); 2019 skb_reset_network_header(skb); 2020 2021 /* Try to align data part correctly */ 2022 if (hhlen) { 2023 skb->data -= hhlen; 2024 skb->tail -= hhlen; 2025 if (len < hhlen) 2026 skb_reset_network_header(skb); 2027 } 2028 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2029 if (err) 2030 goto out_free; 2031 goto retry; 2032 } 2033 2034 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2035 err = -EINVAL; 2036 goto out_unlock; 2037 } 2038 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 2039 !packet_extra_vlan_len_allowed(dev, skb)) { 2040 err = -EMSGSIZE; 2041 goto out_unlock; 2042 } 2043 2044 sockcm_init(&sockc, sk); 2045 if (msg->msg_controllen) { 2046 err = sock_cmsg_send(sk, msg, &sockc); 2047 if (unlikely(err)) 2048 goto out_unlock; 2049 } 2050 2051 skb->protocol = proto; 2052 skb->dev = dev; 2053 skb->priority = sockc.priority; 2054 skb->mark = sockc.mark; 2055 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2056 skb_setup_tx_timestamp(skb, &sockc); 2057 2058 if (unlikely(extra_len == 4)) 2059 skb->no_fcs = 1; 2060 2061 packet_parse_headers(skb, sock); 2062 2063 dev_queue_xmit(skb); 2064 rcu_read_unlock(); 2065 return len; 2066 2067 out_unlock: 2068 rcu_read_unlock(); 2069 out_free: 2070 kfree_skb(skb); 2071 return err; 2072 } 2073 2074 static unsigned int run_filter(struct sk_buff *skb, 2075 const struct sock *sk, 2076 unsigned int res) 2077 { 2078 struct sk_filter *filter; 2079 2080 rcu_read_lock(); 2081 filter = rcu_dereference(sk->sk_filter); 2082 if (filter != NULL) 2083 res = bpf_prog_run_clear_cb(filter->prog, skb); 2084 rcu_read_unlock(); 2085 2086 return res; 2087 } 2088 2089 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2090 size_t *len, int vnet_hdr_sz) 2091 { 2092 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2093 2094 if (*len < vnet_hdr_sz) 2095 return -EINVAL; 2096 *len -= vnet_hdr_sz; 2097 2098 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2099 return -EINVAL; 2100 2101 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2102 } 2103 2104 /* 2105 * This function makes lazy skb cloning in hope that most of packets 2106 * are discarded by BPF. 2107 * 2108 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2109 * and skb->cb are mangled. It works because (and until) packets 2110 * falling here are owned by current CPU. Output packets are cloned 2111 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2112 * sequentially, so that if we return skb to original state on exit, 2113 * we will not harm anyone. 2114 */ 2115 2116 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2117 struct packet_type *pt, struct net_device *orig_dev) 2118 { 2119 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2120 struct sock *sk = NULL; 2121 struct sockaddr_ll *sll; 2122 struct packet_sock *po; 2123 u8 *skb_head = skb->data; 2124 int skb_len = skb->len; 2125 unsigned int snaplen, res; 2126 2127 if (skb->pkt_type == PACKET_LOOPBACK) 2128 goto drop; 2129 2130 sk = pt->af_packet_priv; 2131 po = pkt_sk(sk); 2132 2133 if (!net_eq(dev_net(dev), sock_net(sk))) 2134 goto drop; 2135 2136 skb->dev = dev; 2137 2138 if (dev_has_header(dev)) { 2139 /* The device has an explicit notion of ll header, 2140 * exported to higher levels. 2141 * 2142 * Otherwise, the device hides details of its frame 2143 * structure, so that corresponding packet head is 2144 * never delivered to user. 2145 */ 2146 if (sk->sk_type != SOCK_DGRAM) 2147 skb_push(skb, skb->data - skb_mac_header(skb)); 2148 else if (skb->pkt_type == PACKET_OUTGOING) { 2149 /* Special case: outgoing packets have ll header at head */ 2150 skb_pull(skb, skb_network_offset(skb)); 2151 } 2152 } 2153 2154 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2155 2156 res = run_filter(skb, sk, snaplen); 2157 if (!res) 2158 goto drop_n_restore; 2159 if (snaplen > res) 2160 snaplen = res; 2161 2162 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2163 goto drop_n_acct; 2164 2165 if (skb_shared(skb)) { 2166 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2167 if (nskb == NULL) 2168 goto drop_n_acct; 2169 2170 if (skb_head != skb->data) { 2171 skb->data = skb_head; 2172 skb->len = skb_len; 2173 } 2174 consume_skb(skb); 2175 skb = nskb; 2176 } 2177 2178 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2179 2180 sll = &PACKET_SKB_CB(skb)->sa.ll; 2181 sll->sll_hatype = dev->type; 2182 sll->sll_pkttype = skb->pkt_type; 2183 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2184 sll->sll_ifindex = orig_dev->ifindex; 2185 else 2186 sll->sll_ifindex = dev->ifindex; 2187 2188 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2189 2190 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2191 * Use their space for storing the original skb length. 2192 */ 2193 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2194 2195 if (pskb_trim(skb, snaplen)) 2196 goto drop_n_acct; 2197 2198 skb_set_owner_r(skb, sk); 2199 skb->dev = NULL; 2200 skb_dst_drop(skb); 2201 2202 /* drop conntrack reference */ 2203 nf_reset_ct(skb); 2204 2205 spin_lock(&sk->sk_receive_queue.lock); 2206 po->stats.stats1.tp_packets++; 2207 sock_skb_set_dropcount(sk, skb); 2208 skb_clear_delivery_time(skb); 2209 __skb_queue_tail(&sk->sk_receive_queue, skb); 2210 spin_unlock(&sk->sk_receive_queue.lock); 2211 sk->sk_data_ready(sk); 2212 return 0; 2213 2214 drop_n_acct: 2215 atomic_inc(&po->tp_drops); 2216 sk_drops_inc(sk); 2217 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2218 2219 drop_n_restore: 2220 if (skb_head != skb->data && skb_shared(skb)) { 2221 skb->data = skb_head; 2222 skb->len = skb_len; 2223 } 2224 drop: 2225 sk_skb_reason_drop(sk, skb, drop_reason); 2226 return 0; 2227 } 2228 2229 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2230 struct packet_type *pt, struct net_device *orig_dev) 2231 { 2232 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2233 struct sock *sk = NULL; 2234 struct packet_sock *po; 2235 struct sockaddr_ll *sll; 2236 union tpacket_uhdr h; 2237 u8 *skb_head = skb->data; 2238 int skb_len = skb->len; 2239 unsigned int snaplen, res; 2240 unsigned long status = TP_STATUS_USER; 2241 unsigned short macoff, hdrlen; 2242 unsigned int netoff; 2243 struct sk_buff *copy_skb = NULL; 2244 struct timespec64 ts; 2245 __u32 ts_status; 2246 unsigned int slot_id = 0; 2247 int vnet_hdr_sz = 0; 2248 2249 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2250 * We may add members to them until current aligned size without forcing 2251 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2252 */ 2253 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2254 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2255 2256 if (skb->pkt_type == PACKET_LOOPBACK) 2257 goto drop; 2258 2259 sk = pt->af_packet_priv; 2260 po = pkt_sk(sk); 2261 2262 if (!net_eq(dev_net(dev), sock_net(sk))) 2263 goto drop; 2264 2265 if (dev_has_header(dev)) { 2266 if (sk->sk_type != SOCK_DGRAM) 2267 skb_push(skb, skb->data - skb_mac_header(skb)); 2268 else if (skb->pkt_type == PACKET_OUTGOING) { 2269 /* Special case: outgoing packets have ll header at head */ 2270 skb_pull(skb, skb_network_offset(skb)); 2271 } 2272 } 2273 2274 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2275 2276 res = run_filter(skb, sk, snaplen); 2277 if (!res) 2278 goto drop_n_restore; 2279 2280 /* If we are flooded, just give up */ 2281 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2282 atomic_inc(&po->tp_drops); 2283 goto drop_n_restore; 2284 } 2285 2286 if (skb->ip_summed == CHECKSUM_PARTIAL) 2287 status |= TP_STATUS_CSUMNOTREADY; 2288 else if (skb->pkt_type != PACKET_OUTGOING && 2289 skb_csum_unnecessary(skb)) 2290 status |= TP_STATUS_CSUM_VALID; 2291 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2292 status |= TP_STATUS_GSO_TCP; 2293 2294 if (snaplen > res) 2295 snaplen = res; 2296 2297 if (sk->sk_type == SOCK_DGRAM) { 2298 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2299 po->tp_reserve; 2300 } else { 2301 unsigned int maclen = skb_network_offset(skb); 2302 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2303 (maclen < 16 ? 16 : maclen)) + 2304 po->tp_reserve; 2305 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2306 if (vnet_hdr_sz) 2307 netoff += vnet_hdr_sz; 2308 macoff = netoff - maclen; 2309 } 2310 if (netoff > USHRT_MAX) { 2311 atomic_inc(&po->tp_drops); 2312 goto drop_n_restore; 2313 } 2314 if (po->tp_version <= TPACKET_V2) { 2315 if (macoff + snaplen > po->rx_ring.frame_size) { 2316 if (READ_ONCE(po->copy_thresh) && 2317 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2318 if (skb_shared(skb)) { 2319 copy_skb = skb_clone(skb, GFP_ATOMIC); 2320 } else { 2321 copy_skb = skb_get(skb); 2322 skb_head = skb->data; 2323 } 2324 if (copy_skb) { 2325 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2326 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2327 skb_set_owner_r(copy_skb, sk); 2328 } 2329 } 2330 snaplen = po->rx_ring.frame_size - macoff; 2331 if ((int)snaplen < 0) { 2332 snaplen = 0; 2333 vnet_hdr_sz = 0; 2334 } 2335 } 2336 } else if (unlikely(macoff + snaplen > 2337 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2338 u32 nval; 2339 2340 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2341 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2342 snaplen, nval, macoff); 2343 snaplen = nval; 2344 if (unlikely((int)snaplen < 0)) { 2345 snaplen = 0; 2346 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2347 vnet_hdr_sz = 0; 2348 } 2349 } 2350 spin_lock(&sk->sk_receive_queue.lock); 2351 h.raw = packet_current_rx_frame(po, skb, 2352 TP_STATUS_KERNEL, (macoff+snaplen)); 2353 if (!h.raw) 2354 goto drop_n_account; 2355 2356 if (po->tp_version <= TPACKET_V2) { 2357 slot_id = po->rx_ring.head; 2358 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2359 goto drop_n_account; 2360 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2361 } 2362 2363 if (vnet_hdr_sz && 2364 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2365 sizeof(struct virtio_net_hdr), 2366 vio_le(), true, 0)) { 2367 if (po->tp_version == TPACKET_V3) 2368 prb_clear_blk_fill_status(&po->rx_ring); 2369 goto drop_n_account; 2370 } 2371 2372 if (po->tp_version <= TPACKET_V2) { 2373 packet_increment_rx_head(po, &po->rx_ring); 2374 /* 2375 * LOSING will be reported till you read the stats, 2376 * because it's COR - Clear On Read. 2377 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2378 * at packet level. 2379 */ 2380 if (atomic_read(&po->tp_drops)) 2381 status |= TP_STATUS_LOSING; 2382 } 2383 2384 po->stats.stats1.tp_packets++; 2385 if (copy_skb) { 2386 status |= TP_STATUS_COPY; 2387 skb_clear_delivery_time(copy_skb); 2388 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2389 } 2390 spin_unlock(&sk->sk_receive_queue.lock); 2391 2392 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2393 2394 /* Always timestamp; prefer an existing software timestamp taken 2395 * closer to the time of capture. 2396 */ 2397 ts_status = tpacket_get_timestamp(skb, &ts, 2398 READ_ONCE(po->tp_tstamp) | 2399 SOF_TIMESTAMPING_SOFTWARE); 2400 if (!ts_status) 2401 ktime_get_real_ts64(&ts); 2402 2403 status |= ts_status; 2404 2405 switch (po->tp_version) { 2406 case TPACKET_V1: 2407 h.h1->tp_len = skb->len; 2408 h.h1->tp_snaplen = snaplen; 2409 h.h1->tp_mac = macoff; 2410 h.h1->tp_net = netoff; 2411 h.h1->tp_sec = ts.tv_sec; 2412 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2413 hdrlen = sizeof(*h.h1); 2414 break; 2415 case TPACKET_V2: 2416 h.h2->tp_len = skb->len; 2417 h.h2->tp_snaplen = snaplen; 2418 h.h2->tp_mac = macoff; 2419 h.h2->tp_net = netoff; 2420 h.h2->tp_sec = ts.tv_sec; 2421 h.h2->tp_nsec = ts.tv_nsec; 2422 if (skb_vlan_tag_present(skb)) { 2423 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2424 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2425 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2426 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2427 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2428 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2429 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2430 } else { 2431 h.h2->tp_vlan_tci = 0; 2432 h.h2->tp_vlan_tpid = 0; 2433 } 2434 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2435 hdrlen = sizeof(*h.h2); 2436 break; 2437 case TPACKET_V3: 2438 /* tp_nxt_offset,vlan are already populated above. 2439 * So DONT clear those fields here 2440 */ 2441 h.h3->tp_status |= status; 2442 h.h3->tp_len = skb->len; 2443 h.h3->tp_snaplen = snaplen; 2444 h.h3->tp_mac = macoff; 2445 h.h3->tp_net = netoff; 2446 h.h3->tp_sec = ts.tv_sec; 2447 h.h3->tp_nsec = ts.tv_nsec; 2448 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2449 hdrlen = sizeof(*h.h3); 2450 break; 2451 default: 2452 BUG(); 2453 } 2454 2455 sll = h.raw + TPACKET_ALIGN(hdrlen); 2456 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2457 sll->sll_family = AF_PACKET; 2458 sll->sll_hatype = dev->type; 2459 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2460 vlan_get_protocol_dgram(skb) : skb->protocol; 2461 sll->sll_pkttype = skb->pkt_type; 2462 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2463 sll->sll_ifindex = orig_dev->ifindex; 2464 else 2465 sll->sll_ifindex = dev->ifindex; 2466 2467 smp_mb(); 2468 2469 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2470 if (po->tp_version <= TPACKET_V2) { 2471 u8 *start, *end; 2472 2473 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2474 macoff + snaplen); 2475 2476 for (start = h.raw; start < end; start += PAGE_SIZE) 2477 flush_dcache_page(pgv_to_page(start)); 2478 } 2479 smp_wmb(); 2480 #endif 2481 2482 if (po->tp_version <= TPACKET_V2) { 2483 spin_lock(&sk->sk_receive_queue.lock); 2484 __packet_set_status(po, h.raw, status); 2485 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2486 spin_unlock(&sk->sk_receive_queue.lock); 2487 sk->sk_data_ready(sk); 2488 } else if (po->tp_version == TPACKET_V3) { 2489 prb_clear_blk_fill_status(&po->rx_ring); 2490 } 2491 2492 drop_n_restore: 2493 if (skb_head != skb->data && skb_shared(skb)) { 2494 skb->data = skb_head; 2495 skb->len = skb_len; 2496 } 2497 drop: 2498 sk_skb_reason_drop(sk, skb, drop_reason); 2499 return 0; 2500 2501 drop_n_account: 2502 spin_unlock(&sk->sk_receive_queue.lock); 2503 atomic_inc(&po->tp_drops); 2504 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2505 2506 sk->sk_data_ready(sk); 2507 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2508 goto drop_n_restore; 2509 } 2510 2511 static void tpacket_destruct_skb(struct sk_buff *skb) 2512 { 2513 struct packet_sock *po = pkt_sk(skb->sk); 2514 2515 if (likely(po->tx_ring.pg_vec)) { 2516 void *ph; 2517 __u32 ts; 2518 2519 ph = skb_zcopy_get_nouarg(skb); 2520 packet_dec_pending(&po->tx_ring); 2521 2522 ts = __packet_set_timestamp(po, ph, skb); 2523 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2524 2525 complete(&po->skb_completion); 2526 } 2527 2528 sock_wfree(skb); 2529 } 2530 2531 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2532 { 2533 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2534 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2535 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2536 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2537 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2538 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2539 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2540 2541 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2542 return -EINVAL; 2543 2544 return 0; 2545 } 2546 2547 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2548 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2549 { 2550 int ret; 2551 2552 if (*len < vnet_hdr_sz) 2553 return -EINVAL; 2554 *len -= vnet_hdr_sz; 2555 2556 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2557 return -EFAULT; 2558 2559 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2560 if (ret) 2561 return ret; 2562 2563 /* move iter to point to the start of mac header */ 2564 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2565 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2566 2567 return 0; 2568 } 2569 2570 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2571 void *frame, struct net_device *dev, void *data, int tp_len, 2572 __be16 proto, unsigned char *addr, int hlen, int copylen, 2573 const struct sockcm_cookie *sockc) 2574 { 2575 union tpacket_uhdr ph; 2576 int to_write, offset, len, nr_frags, len_max; 2577 struct socket *sock = po->sk.sk_socket; 2578 struct page *page; 2579 int err; 2580 2581 ph.raw = frame; 2582 2583 skb->protocol = proto; 2584 skb->dev = dev; 2585 skb->priority = sockc->priority; 2586 skb->mark = sockc->mark; 2587 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2588 skb_setup_tx_timestamp(skb, sockc); 2589 skb_zcopy_set_nouarg(skb, ph.raw); 2590 2591 skb_reserve(skb, hlen); 2592 skb_reset_network_header(skb); 2593 2594 to_write = tp_len; 2595 2596 if (sock->type == SOCK_DGRAM) { 2597 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2598 NULL, tp_len); 2599 if (unlikely(err < 0)) 2600 return -EINVAL; 2601 } else if (copylen) { 2602 int hdrlen = min_t(int, copylen, tp_len); 2603 2604 skb_push(skb, dev->hard_header_len); 2605 skb_put(skb, copylen - dev->hard_header_len); 2606 err = skb_store_bits(skb, 0, data, hdrlen); 2607 if (unlikely(err)) 2608 return err; 2609 if (!dev_validate_header(dev, skb->data, hdrlen)) 2610 return -EINVAL; 2611 2612 data += hdrlen; 2613 to_write -= hdrlen; 2614 } 2615 2616 offset = offset_in_page(data); 2617 len_max = PAGE_SIZE - offset; 2618 len = ((to_write > len_max) ? len_max : to_write); 2619 2620 skb->data_len = to_write; 2621 skb->len += to_write; 2622 skb->truesize += to_write; 2623 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2624 2625 while (likely(to_write)) { 2626 nr_frags = skb_shinfo(skb)->nr_frags; 2627 2628 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2629 pr_err("Packet exceed the number of skb frags(%u)\n", 2630 (unsigned int)MAX_SKB_FRAGS); 2631 return -EFAULT; 2632 } 2633 2634 page = pgv_to_page(data); 2635 data += len; 2636 flush_dcache_page(page); 2637 get_page(page); 2638 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2639 to_write -= len; 2640 offset = 0; 2641 len_max = PAGE_SIZE; 2642 len = ((to_write > len_max) ? len_max : to_write); 2643 } 2644 2645 packet_parse_headers(skb, sock); 2646 2647 return tp_len; 2648 } 2649 2650 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2651 int size_max, void **data) 2652 { 2653 union tpacket_uhdr ph; 2654 int tp_len, off; 2655 2656 ph.raw = frame; 2657 2658 switch (po->tp_version) { 2659 case TPACKET_V3: 2660 if (ph.h3->tp_next_offset != 0) { 2661 pr_warn_once("variable sized slot not supported"); 2662 return -EINVAL; 2663 } 2664 tp_len = ph.h3->tp_len; 2665 break; 2666 case TPACKET_V2: 2667 tp_len = ph.h2->tp_len; 2668 break; 2669 default: 2670 tp_len = ph.h1->tp_len; 2671 break; 2672 } 2673 if (unlikely(tp_len > size_max)) { 2674 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2675 return -EMSGSIZE; 2676 } 2677 2678 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2679 int off_min, off_max; 2680 2681 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2682 off_max = po->tx_ring.frame_size - tp_len; 2683 if (po->sk.sk_type == SOCK_DGRAM) { 2684 switch (po->tp_version) { 2685 case TPACKET_V3: 2686 off = ph.h3->tp_net; 2687 break; 2688 case TPACKET_V2: 2689 off = ph.h2->tp_net; 2690 break; 2691 default: 2692 off = ph.h1->tp_net; 2693 break; 2694 } 2695 } else { 2696 switch (po->tp_version) { 2697 case TPACKET_V3: 2698 off = ph.h3->tp_mac; 2699 break; 2700 case TPACKET_V2: 2701 off = ph.h2->tp_mac; 2702 break; 2703 default: 2704 off = ph.h1->tp_mac; 2705 break; 2706 } 2707 } 2708 if (unlikely((off < off_min) || (off_max < off))) 2709 return -EINVAL; 2710 } else { 2711 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2712 } 2713 2714 *data = frame + off; 2715 return tp_len; 2716 } 2717 2718 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2719 { 2720 struct sk_buff *skb = NULL; 2721 struct net_device *dev; 2722 struct virtio_net_hdr vnet_hdr; 2723 bool has_vnet_hdr = false; 2724 struct sockcm_cookie sockc; 2725 __be16 proto; 2726 int err, reserve = 0; 2727 void *ph; 2728 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2729 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2730 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2731 unsigned char *addr = NULL; 2732 int tp_len, size_max; 2733 void *data; 2734 int len_sum = 0; 2735 int status = TP_STATUS_AVAILABLE; 2736 int hlen, tlen, copylen = 0; 2737 long timeo; 2738 2739 mutex_lock(&po->pg_vec_lock); 2740 2741 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2742 * we need to confirm it under protection of pg_vec_lock. 2743 */ 2744 if (unlikely(!po->tx_ring.pg_vec)) { 2745 err = -EBUSY; 2746 goto out; 2747 } 2748 if (likely(saddr == NULL)) { 2749 dev = packet_cached_dev_get(po); 2750 proto = READ_ONCE(po->num); 2751 } else { 2752 err = -EINVAL; 2753 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2754 goto out; 2755 if (msg->msg_namelen < (saddr->sll_halen 2756 + offsetof(struct sockaddr_ll, 2757 sll_addr))) 2758 goto out; 2759 proto = saddr->sll_protocol; 2760 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2761 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2762 if (dev && msg->msg_namelen < dev->addr_len + 2763 offsetof(struct sockaddr_ll, sll_addr)) 2764 goto out_put; 2765 addr = saddr->sll_addr; 2766 } 2767 } 2768 2769 err = -ENXIO; 2770 if (unlikely(dev == NULL)) 2771 goto out; 2772 err = -ENETDOWN; 2773 if (unlikely(!(dev->flags & IFF_UP))) 2774 goto out_put; 2775 2776 sockcm_init(&sockc, &po->sk); 2777 if (msg->msg_controllen) { 2778 err = sock_cmsg_send(&po->sk, msg, &sockc); 2779 if (unlikely(err)) 2780 goto out_put; 2781 } 2782 2783 if (po->sk.sk_socket->type == SOCK_RAW) 2784 reserve = dev->hard_header_len; 2785 size_max = po->tx_ring.frame_size 2786 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2787 2788 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2789 size_max = dev->mtu + reserve + VLAN_HLEN; 2790 2791 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2792 reinit_completion(&po->skb_completion); 2793 2794 do { 2795 ph = packet_current_frame(po, &po->tx_ring, 2796 TP_STATUS_SEND_REQUEST); 2797 if (unlikely(ph == NULL)) { 2798 /* Note: packet_read_pending() might be slow if we 2799 * have to call it as it's per_cpu variable, but in 2800 * fast-path we don't have to call it, only when ph 2801 * is NULL, we need to check the pending_refcnt. 2802 */ 2803 if (need_wait && packet_read_pending(&po->tx_ring)) { 2804 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2805 if (timeo <= 0) { 2806 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2807 goto out_put; 2808 } 2809 /* check for additional frames */ 2810 continue; 2811 } else 2812 break; 2813 } 2814 2815 skb = NULL; 2816 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2817 if (tp_len < 0) 2818 goto tpacket_error; 2819 2820 status = TP_STATUS_SEND_REQUEST; 2821 hlen = LL_RESERVED_SPACE(dev); 2822 tlen = dev->needed_tailroom; 2823 if (vnet_hdr_sz) { 2824 data += vnet_hdr_sz; 2825 tp_len -= vnet_hdr_sz; 2826 if (tp_len < 0) { 2827 tp_len = -EINVAL; 2828 goto tpacket_error; 2829 } 2830 memcpy(&vnet_hdr, data - vnet_hdr_sz, sizeof(vnet_hdr)); 2831 if (__packet_snd_vnet_parse(&vnet_hdr, tp_len)) { 2832 tp_len = -EINVAL; 2833 goto tpacket_error; 2834 } 2835 copylen = __virtio16_to_cpu(vio_le(), 2836 vnet_hdr.hdr_len); 2837 has_vnet_hdr = true; 2838 } 2839 copylen = max_t(int, copylen, dev->hard_header_len); 2840 skb = sock_alloc_send_skb(&po->sk, 2841 hlen + tlen + sizeof(struct sockaddr_ll) + 2842 (copylen - dev->hard_header_len), 2843 !need_wait, &err); 2844 2845 if (unlikely(skb == NULL)) { 2846 /* we assume the socket was initially writeable ... */ 2847 if (likely(len_sum > 0)) 2848 err = len_sum; 2849 goto out_status; 2850 } 2851 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2852 addr, hlen, copylen, &sockc); 2853 if (likely(tp_len >= 0) && 2854 tp_len > dev->mtu + reserve && 2855 !vnet_hdr_sz && 2856 !packet_extra_vlan_len_allowed(dev, skb)) 2857 tp_len = -EMSGSIZE; 2858 2859 if (unlikely(tp_len < 0)) { 2860 tpacket_error: 2861 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2862 __packet_set_status(po, ph, 2863 TP_STATUS_AVAILABLE); 2864 packet_increment_head(&po->tx_ring); 2865 kfree_skb(skb); 2866 continue; 2867 } else { 2868 status = TP_STATUS_WRONG_FORMAT; 2869 err = tp_len; 2870 goto out_status; 2871 } 2872 } 2873 2874 if (has_vnet_hdr) { 2875 if (virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le())) { 2876 tp_len = -EINVAL; 2877 goto tpacket_error; 2878 } 2879 virtio_net_hdr_set_proto(skb, &vnet_hdr); 2880 } 2881 2882 skb->destructor = tpacket_destruct_skb; 2883 __packet_set_status(po, ph, TP_STATUS_SENDING); 2884 packet_inc_pending(&po->tx_ring); 2885 2886 status = TP_STATUS_SEND_REQUEST; 2887 err = packet_xmit(po, skb); 2888 if (unlikely(err != 0)) { 2889 if (err > 0) 2890 err = net_xmit_errno(err); 2891 if (err && __packet_get_status(po, ph) == 2892 TP_STATUS_AVAILABLE) { 2893 /* skb was destructed already */ 2894 skb = NULL; 2895 goto out_status; 2896 } 2897 /* 2898 * skb was dropped but not destructed yet; 2899 * let's treat it like congestion or err < 0 2900 */ 2901 err = 0; 2902 } 2903 packet_increment_head(&po->tx_ring); 2904 len_sum += tp_len; 2905 } while (1); 2906 2907 err = len_sum; 2908 goto out_put; 2909 2910 out_status: 2911 __packet_set_status(po, ph, status); 2912 kfree_skb(skb); 2913 out_put: 2914 dev_put(dev); 2915 out: 2916 mutex_unlock(&po->pg_vec_lock); 2917 return err; 2918 } 2919 2920 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2921 size_t reserve, size_t len, 2922 size_t linear, int noblock, 2923 int *err) 2924 { 2925 struct sk_buff *skb; 2926 2927 /* Under a page? Don't bother with paged skb. */ 2928 if (prepad + len < PAGE_SIZE || !linear) 2929 linear = len; 2930 2931 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2932 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2933 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2934 err, PAGE_ALLOC_COSTLY_ORDER); 2935 if (!skb) 2936 return NULL; 2937 2938 skb_reserve(skb, reserve); 2939 skb_put(skb, linear); 2940 skb->data_len = len - linear; 2941 skb->len += len - linear; 2942 2943 return skb; 2944 } 2945 2946 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2947 { 2948 struct sock *sk = sock->sk; 2949 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2950 struct sk_buff *skb; 2951 struct net_device *dev; 2952 __be16 proto; 2953 unsigned char *addr = NULL; 2954 int err, reserve = 0; 2955 struct sockcm_cookie sockc; 2956 struct virtio_net_hdr vnet_hdr = { 0 }; 2957 int offset = 0; 2958 struct packet_sock *po = pkt_sk(sk); 2959 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2960 int hlen, tlen, linear; 2961 int extra_len = 0; 2962 2963 /* 2964 * Get and verify the address. 2965 */ 2966 2967 if (likely(saddr == NULL)) { 2968 dev = packet_cached_dev_get(po); 2969 proto = READ_ONCE(po->num); 2970 } else { 2971 err = -EINVAL; 2972 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2973 goto out; 2974 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2975 goto out; 2976 proto = saddr->sll_protocol; 2977 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2978 if (sock->type == SOCK_DGRAM) { 2979 if (dev && msg->msg_namelen < dev->addr_len + 2980 offsetof(struct sockaddr_ll, sll_addr)) 2981 goto out_unlock; 2982 addr = saddr->sll_addr; 2983 } 2984 } 2985 2986 err = -ENXIO; 2987 if (unlikely(dev == NULL)) 2988 goto out_unlock; 2989 err = -ENETDOWN; 2990 if (unlikely(!(dev->flags & IFF_UP))) 2991 goto out_unlock; 2992 2993 sockcm_init(&sockc, sk); 2994 if (msg->msg_controllen) { 2995 err = sock_cmsg_send(sk, msg, &sockc); 2996 if (unlikely(err)) 2997 goto out_unlock; 2998 } 2999 3000 if (sock->type == SOCK_RAW) 3001 reserve = dev->hard_header_len; 3002 if (vnet_hdr_sz) { 3003 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3004 if (err) 3005 goto out_unlock; 3006 } 3007 3008 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3009 if (!netif_supports_nofcs(dev)) { 3010 err = -EPROTONOSUPPORT; 3011 goto out_unlock; 3012 } 3013 extra_len = 4; /* We're doing our own CRC */ 3014 } 3015 3016 err = -EMSGSIZE; 3017 if (!vnet_hdr.gso_type && 3018 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3019 goto out_unlock; 3020 3021 err = -ENOBUFS; 3022 hlen = LL_RESERVED_SPACE(dev); 3023 tlen = dev->needed_tailroom; 3024 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3025 linear = max(linear, min_t(int, len, dev->hard_header_len)); 3026 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3027 msg->msg_flags & MSG_DONTWAIT, &err); 3028 if (skb == NULL) 3029 goto out_unlock; 3030 3031 skb_reset_network_header(skb); 3032 3033 err = -EINVAL; 3034 if (sock->type == SOCK_DGRAM) { 3035 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3036 if (unlikely(offset < 0)) 3037 goto out_free; 3038 } else if (reserve) { 3039 skb_reserve(skb, -reserve); 3040 if (len < reserve + sizeof(struct ipv6hdr) && 3041 dev->min_header_len != dev->hard_header_len) 3042 skb_reset_network_header(skb); 3043 } 3044 3045 /* Returns -EFAULT on error */ 3046 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3047 if (err) 3048 goto out_free; 3049 3050 if ((sock->type == SOCK_RAW && 3051 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3052 err = -EINVAL; 3053 goto out_free; 3054 } 3055 3056 skb_setup_tx_timestamp(skb, &sockc); 3057 3058 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3059 !packet_extra_vlan_len_allowed(dev, skb)) { 3060 err = -EMSGSIZE; 3061 goto out_free; 3062 } 3063 3064 skb->protocol = proto; 3065 skb->dev = dev; 3066 skb->priority = sockc.priority; 3067 skb->mark = sockc.mark; 3068 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3069 3070 if (unlikely(extra_len == 4)) 3071 skb->no_fcs = 1; 3072 3073 packet_parse_headers(skb, sock); 3074 3075 if (vnet_hdr_sz) { 3076 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3077 if (err) 3078 goto out_free; 3079 len += vnet_hdr_sz; 3080 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3081 } 3082 3083 err = packet_xmit(po, skb); 3084 3085 if (unlikely(err != 0)) { 3086 if (err > 0) 3087 err = net_xmit_errno(err); 3088 if (err) 3089 goto out_unlock; 3090 } 3091 3092 dev_put(dev); 3093 3094 return len; 3095 3096 out_free: 3097 kfree_skb(skb); 3098 out_unlock: 3099 dev_put(dev); 3100 out: 3101 return err; 3102 } 3103 3104 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3105 { 3106 struct sock *sk = sock->sk; 3107 struct packet_sock *po = pkt_sk(sk); 3108 3109 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3110 * tpacket_snd() will redo the check safely. 3111 */ 3112 if (data_race(po->tx_ring.pg_vec)) 3113 return tpacket_snd(po, msg); 3114 3115 return packet_snd(sock, msg, len); 3116 } 3117 3118 /* 3119 * Close a PACKET socket. This is fairly simple. We immediately go 3120 * to 'closed' state and remove our protocol entry in the device list. 3121 */ 3122 3123 static int packet_release(struct socket *sock) 3124 { 3125 struct sock *sk = sock->sk; 3126 struct packet_sock *po; 3127 struct packet_fanout *f; 3128 struct net *net; 3129 union tpacket_req_u req_u; 3130 3131 if (!sk) 3132 return 0; 3133 3134 net = sock_net(sk); 3135 po = pkt_sk(sk); 3136 3137 mutex_lock(&net->packet.sklist_lock); 3138 sk_del_node_init_rcu(sk); 3139 mutex_unlock(&net->packet.sklist_lock); 3140 3141 sock_prot_inuse_add(net, sk->sk_prot, -1); 3142 3143 spin_lock(&po->bind_lock); 3144 unregister_prot_hook(sk, false); 3145 WRITE_ONCE(po->num, 0); 3146 packet_cached_dev_reset(po); 3147 3148 if (po->prot_hook.dev) { 3149 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3150 po->prot_hook.dev = NULL; 3151 } 3152 spin_unlock(&po->bind_lock); 3153 3154 packet_flush_mclist(sk); 3155 3156 lock_sock(sk); 3157 if (po->rx_ring.pg_vec) { 3158 memset(&req_u, 0, sizeof(req_u)); 3159 packet_set_ring(sk, &req_u, 1, 0); 3160 } 3161 3162 if (po->tx_ring.pg_vec) { 3163 memset(&req_u, 0, sizeof(req_u)); 3164 packet_set_ring(sk, &req_u, 1, 1); 3165 } 3166 release_sock(sk); 3167 3168 f = fanout_release(sk); 3169 3170 synchronize_net(); 3171 3172 kfree(po->rollover); 3173 if (f) { 3174 fanout_release_data(f); 3175 kvfree(f); 3176 } 3177 /* 3178 * Now the socket is dead. No more input will appear. 3179 */ 3180 sock_orphan(sk); 3181 sock->sk = NULL; 3182 3183 /* Purge queues */ 3184 3185 skb_queue_purge(&sk->sk_receive_queue); 3186 packet_free_pending(po); 3187 3188 sock_put(sk); 3189 return 0; 3190 } 3191 3192 /* 3193 * Attach a packet hook. 3194 */ 3195 3196 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3197 __be16 proto) 3198 { 3199 struct packet_sock *po = pkt_sk(sk); 3200 struct net_device *dev = NULL; 3201 bool unlisted = false; 3202 bool need_rehook; 3203 int ret = 0; 3204 3205 lock_sock(sk); 3206 spin_lock(&po->bind_lock); 3207 if (!proto) 3208 proto = po->num; 3209 3210 rcu_read_lock(); 3211 3212 if (po->fanout) { 3213 ret = -EINVAL; 3214 goto out_unlock; 3215 } 3216 3217 if (name) { 3218 dev = dev_get_by_name_rcu(sock_net(sk), name); 3219 if (!dev) { 3220 ret = -ENODEV; 3221 goto out_unlock; 3222 } 3223 } else if (ifindex) { 3224 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3225 if (!dev) { 3226 ret = -ENODEV; 3227 goto out_unlock; 3228 } 3229 } 3230 3231 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3232 3233 if (need_rehook) { 3234 dev_hold(dev); 3235 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3236 rcu_read_unlock(); 3237 /* prevents packet_notifier() from calling 3238 * register_prot_hook() 3239 */ 3240 WRITE_ONCE(po->num, 0); 3241 __unregister_prot_hook(sk, true); 3242 rcu_read_lock(); 3243 if (dev) 3244 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3245 dev->ifindex); 3246 } 3247 3248 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3249 WRITE_ONCE(po->num, proto); 3250 po->prot_hook.type = proto; 3251 3252 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3253 3254 if (unlikely(unlisted)) { 3255 po->prot_hook.dev = NULL; 3256 WRITE_ONCE(po->ifindex, -1); 3257 packet_cached_dev_reset(po); 3258 } else { 3259 netdev_hold(dev, &po->prot_hook.dev_tracker, 3260 GFP_ATOMIC); 3261 po->prot_hook.dev = dev; 3262 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3263 packet_cached_dev_assign(po, dev); 3264 } 3265 dev_put(dev); 3266 } 3267 3268 if (proto == 0 || !need_rehook) 3269 goto out_unlock; 3270 3271 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3272 register_prot_hook(sk); 3273 } else { 3274 sk->sk_err = ENETDOWN; 3275 if (!sock_flag(sk, SOCK_DEAD)) 3276 sk_error_report(sk); 3277 } 3278 3279 out_unlock: 3280 rcu_read_unlock(); 3281 spin_unlock(&po->bind_lock); 3282 release_sock(sk); 3283 return ret; 3284 } 3285 3286 /* 3287 * Bind a packet socket to a device 3288 */ 3289 3290 static int packet_bind_spkt(struct socket *sock, struct sockaddr_unsized *uaddr, 3291 int addr_len) 3292 { 3293 struct sock *sk = sock->sk; 3294 struct sockaddr *sa = (struct sockaddr *)uaddr; 3295 char name[sizeof(sa->sa_data) + 1]; 3296 3297 /* 3298 * Check legality 3299 */ 3300 3301 if (addr_len != sizeof(struct sockaddr)) 3302 return -EINVAL; 3303 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3304 * zero-terminated. 3305 */ 3306 memcpy(name, sa->sa_data, sizeof(sa->sa_data)); 3307 name[sizeof(sa->sa_data)] = 0; 3308 3309 return packet_do_bind(sk, name, 0, 0); 3310 } 3311 3312 static int packet_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len) 3313 { 3314 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3315 struct sock *sk = sock->sk; 3316 3317 /* 3318 * Check legality 3319 */ 3320 3321 if (addr_len < sizeof(struct sockaddr_ll)) 3322 return -EINVAL; 3323 if (sll->sll_family != AF_PACKET) 3324 return -EINVAL; 3325 3326 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3327 } 3328 3329 static struct proto packet_proto = { 3330 .name = "PACKET", 3331 .owner = THIS_MODULE, 3332 .obj_size = sizeof(struct packet_sock), 3333 }; 3334 3335 /* 3336 * Create a packet of type SOCK_PACKET. 3337 */ 3338 3339 static int packet_create(struct net *net, struct socket *sock, int protocol, 3340 int kern) 3341 { 3342 struct sock *sk; 3343 struct packet_sock *po; 3344 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3345 int err; 3346 3347 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3348 return -EPERM; 3349 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3350 sock->type != SOCK_PACKET) 3351 return -ESOCKTNOSUPPORT; 3352 3353 sock->state = SS_UNCONNECTED; 3354 3355 err = -ENOBUFS; 3356 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3357 if (sk == NULL) 3358 goto out; 3359 3360 sock->ops = &packet_ops; 3361 if (sock->type == SOCK_PACKET) 3362 sock->ops = &packet_ops_spkt; 3363 3364 po = pkt_sk(sk); 3365 err = packet_alloc_pending(po); 3366 if (err) 3367 goto out_sk_free; 3368 3369 sock_init_data(sock, sk); 3370 3371 init_completion(&po->skb_completion); 3372 sk->sk_family = PF_PACKET; 3373 po->num = proto; 3374 3375 packet_cached_dev_reset(po); 3376 3377 sk->sk_destruct = packet_sock_destruct; 3378 3379 /* 3380 * Attach a protocol block 3381 */ 3382 3383 spin_lock_init(&po->bind_lock); 3384 mutex_init(&po->pg_vec_lock); 3385 po->rollover = NULL; 3386 po->prot_hook.func = packet_rcv; 3387 3388 if (sock->type == SOCK_PACKET) 3389 po->prot_hook.func = packet_rcv_spkt; 3390 3391 po->prot_hook.af_packet_priv = sk; 3392 po->prot_hook.af_packet_net = sock_net(sk); 3393 3394 if (proto) { 3395 po->prot_hook.type = proto; 3396 __register_prot_hook(sk); 3397 } 3398 3399 mutex_lock(&net->packet.sklist_lock); 3400 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3401 mutex_unlock(&net->packet.sklist_lock); 3402 3403 sock_prot_inuse_add(net, &packet_proto, 1); 3404 3405 return 0; 3406 out_sk_free: 3407 sk_free(sk); 3408 out: 3409 return err; 3410 } 3411 3412 /* 3413 * Pull a packet from our receive queue and hand it to the user. 3414 * If necessary we block. 3415 */ 3416 3417 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3418 int flags) 3419 { 3420 struct sock *sk = sock->sk; 3421 struct sk_buff *skb; 3422 int copied, err; 3423 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3424 unsigned int origlen = 0; 3425 3426 err = -EINVAL; 3427 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3428 goto out; 3429 3430 #if 0 3431 /* What error should we return now? EUNATTACH? */ 3432 if (pkt_sk(sk)->ifindex < 0) 3433 return -ENODEV; 3434 #endif 3435 3436 if (flags & MSG_ERRQUEUE) { 3437 err = sock_recv_errqueue(sk, msg, len, 3438 SOL_PACKET, PACKET_TX_TIMESTAMP); 3439 goto out; 3440 } 3441 3442 /* 3443 * Call the generic datagram receiver. This handles all sorts 3444 * of horrible races and re-entrancy so we can forget about it 3445 * in the protocol layers. 3446 * 3447 * Now it will return ENETDOWN, if device have just gone down, 3448 * but then it will block. 3449 */ 3450 3451 skb = skb_recv_datagram(sk, flags, &err); 3452 3453 /* 3454 * An error occurred so return it. Because skb_recv_datagram() 3455 * handles the blocking we don't see and worry about blocking 3456 * retries. 3457 */ 3458 3459 if (skb == NULL) 3460 goto out; 3461 3462 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3463 3464 if (vnet_hdr_len) { 3465 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3466 if (err) 3467 goto out_free; 3468 } 3469 3470 /* You lose any data beyond the buffer you gave. If it worries 3471 * a user program they can ask the device for its MTU 3472 * anyway. 3473 */ 3474 copied = skb->len; 3475 if (copied > len) { 3476 copied = len; 3477 msg->msg_flags |= MSG_TRUNC; 3478 } 3479 3480 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3481 if (err) 3482 goto out_free; 3483 3484 if (sock->type != SOCK_PACKET) { 3485 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3486 3487 /* Original length was stored in sockaddr_ll fields */ 3488 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3489 sll->sll_family = AF_PACKET; 3490 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3491 vlan_get_protocol_dgram(skb) : skb->protocol; 3492 } 3493 3494 sock_recv_cmsgs(msg, sk, skb); 3495 3496 if (msg->msg_name) { 3497 const size_t max_len = min(sizeof(skb->cb), 3498 sizeof(struct sockaddr_storage)); 3499 int copy_len; 3500 3501 /* If the address length field is there to be filled 3502 * in, we fill it in now. 3503 */ 3504 if (sock->type == SOCK_PACKET) { 3505 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3506 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3507 copy_len = msg->msg_namelen; 3508 } else { 3509 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3510 3511 msg->msg_namelen = sll->sll_halen + 3512 offsetof(struct sockaddr_ll, sll_addr); 3513 copy_len = msg->msg_namelen; 3514 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3515 memset(msg->msg_name + 3516 offsetof(struct sockaddr_ll, sll_addr), 3517 0, sizeof(sll->sll_addr)); 3518 msg->msg_namelen = sizeof(struct sockaddr_ll); 3519 } 3520 } 3521 if (WARN_ON_ONCE(copy_len > max_len)) { 3522 copy_len = max_len; 3523 msg->msg_namelen = copy_len; 3524 } 3525 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3526 } 3527 3528 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3529 struct tpacket_auxdata aux; 3530 3531 aux.tp_status = TP_STATUS_USER; 3532 if (skb->ip_summed == CHECKSUM_PARTIAL) 3533 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3534 else if (skb->pkt_type != PACKET_OUTGOING && 3535 skb_csum_unnecessary(skb)) 3536 aux.tp_status |= TP_STATUS_CSUM_VALID; 3537 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3538 aux.tp_status |= TP_STATUS_GSO_TCP; 3539 3540 aux.tp_len = origlen; 3541 aux.tp_snaplen = skb->len; 3542 aux.tp_mac = 0; 3543 aux.tp_net = skb_network_offset(skb); 3544 if (skb_vlan_tag_present(skb)) { 3545 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3546 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3547 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3548 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3549 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3550 struct net_device *dev; 3551 3552 rcu_read_lock(); 3553 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3554 if (dev) { 3555 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3556 aux.tp_vlan_tpid = ntohs(skb->protocol); 3557 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3558 } else { 3559 aux.tp_vlan_tci = 0; 3560 aux.tp_vlan_tpid = 0; 3561 } 3562 rcu_read_unlock(); 3563 } else { 3564 aux.tp_vlan_tci = 0; 3565 aux.tp_vlan_tpid = 0; 3566 } 3567 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3568 } 3569 3570 /* 3571 * Free or return the buffer as appropriate. Again this 3572 * hides all the races and re-entrancy issues from us. 3573 */ 3574 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3575 3576 out_free: 3577 skb_free_datagram(sk, skb); 3578 out: 3579 return err; 3580 } 3581 3582 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3583 int peer) 3584 { 3585 struct net_device *dev; 3586 struct sock *sk = sock->sk; 3587 3588 if (peer) 3589 return -EOPNOTSUPP; 3590 3591 uaddr->sa_family = AF_PACKET; 3592 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3593 rcu_read_lock(); 3594 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3595 if (dev) 3596 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3597 rcu_read_unlock(); 3598 3599 return sizeof(*uaddr); 3600 } 3601 3602 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3603 int peer) 3604 { 3605 struct net_device *dev; 3606 struct sock *sk = sock->sk; 3607 struct packet_sock *po = pkt_sk(sk); 3608 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3609 int ifindex; 3610 3611 if (peer) 3612 return -EOPNOTSUPP; 3613 3614 ifindex = READ_ONCE(po->ifindex); 3615 sll->sll_family = AF_PACKET; 3616 sll->sll_ifindex = ifindex; 3617 sll->sll_protocol = READ_ONCE(po->num); 3618 sll->sll_pkttype = 0; 3619 rcu_read_lock(); 3620 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3621 if (dev) { 3622 sll->sll_hatype = dev->type; 3623 sll->sll_halen = dev->addr_len; 3624 3625 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3626 memcpy(((struct sockaddr_storage *)sll)->__data + 3627 offsetof(struct sockaddr_ll, sll_addr) - 3628 offsetofend(struct sockaddr_ll, sll_family), 3629 dev->dev_addr, dev->addr_len); 3630 } else { 3631 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3632 sll->sll_halen = 0; 3633 } 3634 rcu_read_unlock(); 3635 3636 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3637 } 3638 3639 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3640 int what) 3641 { 3642 switch (i->type) { 3643 case PACKET_MR_MULTICAST: 3644 if (i->alen != dev->addr_len) 3645 return -EINVAL; 3646 if (what > 0) 3647 return dev_mc_add(dev, i->addr); 3648 else 3649 return dev_mc_del(dev, i->addr); 3650 break; 3651 case PACKET_MR_PROMISC: 3652 return dev_set_promiscuity(dev, what); 3653 case PACKET_MR_ALLMULTI: 3654 return dev_set_allmulti(dev, what); 3655 case PACKET_MR_UNICAST: 3656 if (i->alen != dev->addr_len) 3657 return -EINVAL; 3658 if (what > 0) 3659 return dev_uc_add(dev, i->addr); 3660 else 3661 return dev_uc_del(dev, i->addr); 3662 break; 3663 default: 3664 break; 3665 } 3666 return 0; 3667 } 3668 3669 static void packet_dev_mclist_delete(struct net_device *dev, 3670 struct packet_mclist **mlp, 3671 struct list_head *list) 3672 { 3673 struct packet_mclist *ml; 3674 3675 while ((ml = *mlp) != NULL) { 3676 if (ml->ifindex == dev->ifindex) { 3677 list_add(&ml->remove_list, list); 3678 *mlp = ml->next; 3679 } else 3680 mlp = &ml->next; 3681 } 3682 } 3683 3684 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3685 { 3686 struct packet_sock *po = pkt_sk(sk); 3687 struct packet_mclist *ml, *i; 3688 struct net_device *dev; 3689 int err; 3690 3691 rtnl_lock(); 3692 3693 err = -ENODEV; 3694 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3695 if (!dev) 3696 goto done; 3697 3698 err = -EINVAL; 3699 if (mreq->mr_alen > dev->addr_len) 3700 goto done; 3701 3702 err = -ENOBUFS; 3703 i = kmalloc_obj(*i); 3704 if (i == NULL) 3705 goto done; 3706 3707 err = 0; 3708 for (ml = po->mclist; ml; ml = ml->next) { 3709 if (ml->ifindex == mreq->mr_ifindex && 3710 ml->type == mreq->mr_type && 3711 ml->alen == mreq->mr_alen && 3712 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3713 ml->count++; 3714 /* Free the new element ... */ 3715 kfree(i); 3716 goto done; 3717 } 3718 } 3719 3720 i->type = mreq->mr_type; 3721 i->ifindex = mreq->mr_ifindex; 3722 i->alen = mreq->mr_alen; 3723 memcpy(i->addr, mreq->mr_address, i->alen); 3724 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3725 i->count = 1; 3726 INIT_LIST_HEAD(&i->remove_list); 3727 i->next = po->mclist; 3728 po->mclist = i; 3729 err = packet_dev_mc(dev, i, 1); 3730 if (err) { 3731 po->mclist = i->next; 3732 kfree(i); 3733 } 3734 3735 done: 3736 rtnl_unlock(); 3737 return err; 3738 } 3739 3740 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3741 { 3742 struct packet_mclist *ml, **mlp; 3743 3744 rtnl_lock(); 3745 3746 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3747 if (ml->ifindex == mreq->mr_ifindex && 3748 ml->type == mreq->mr_type && 3749 ml->alen == mreq->mr_alen && 3750 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3751 if (--ml->count == 0) { 3752 struct net_device *dev; 3753 *mlp = ml->next; 3754 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3755 if (dev) 3756 packet_dev_mc(dev, ml, -1); 3757 kfree(ml); 3758 } 3759 break; 3760 } 3761 } 3762 rtnl_unlock(); 3763 return 0; 3764 } 3765 3766 static void packet_flush_mclist(struct sock *sk) 3767 { 3768 struct packet_sock *po = pkt_sk(sk); 3769 struct packet_mclist *ml; 3770 3771 if (!po->mclist) 3772 return; 3773 3774 rtnl_lock(); 3775 while ((ml = po->mclist) != NULL) { 3776 struct net_device *dev; 3777 3778 po->mclist = ml->next; 3779 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3780 if (dev != NULL) 3781 packet_dev_mc(dev, ml, -1); 3782 kfree(ml); 3783 } 3784 rtnl_unlock(); 3785 } 3786 3787 static int 3788 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3789 unsigned int optlen) 3790 { 3791 struct sock *sk = sock->sk; 3792 struct packet_sock *po = pkt_sk(sk); 3793 int ret; 3794 3795 if (level != SOL_PACKET) 3796 return -ENOPROTOOPT; 3797 3798 switch (optname) { 3799 case PACKET_ADD_MEMBERSHIP: 3800 case PACKET_DROP_MEMBERSHIP: 3801 { 3802 struct packet_mreq_max mreq; 3803 int len = optlen; 3804 memset(&mreq, 0, sizeof(mreq)); 3805 if (len < sizeof(struct packet_mreq)) 3806 return -EINVAL; 3807 if (len > sizeof(mreq)) 3808 len = sizeof(mreq); 3809 if (copy_from_sockptr(&mreq, optval, len)) 3810 return -EFAULT; 3811 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3812 return -EINVAL; 3813 if (optname == PACKET_ADD_MEMBERSHIP) 3814 ret = packet_mc_add(sk, &mreq); 3815 else 3816 ret = packet_mc_drop(sk, &mreq); 3817 return ret; 3818 } 3819 3820 case PACKET_RX_RING: 3821 case PACKET_TX_RING: 3822 { 3823 union tpacket_req_u req_u; 3824 3825 ret = -EINVAL; 3826 lock_sock(sk); 3827 switch (po->tp_version) { 3828 case TPACKET_V1: 3829 case TPACKET_V2: 3830 if (optlen < sizeof(req_u.req)) 3831 break; 3832 ret = copy_from_sockptr(&req_u.req, optval, 3833 sizeof(req_u.req)) ? 3834 -EINVAL : 0; 3835 break; 3836 case TPACKET_V3: 3837 default: 3838 if (optlen < sizeof(req_u.req3)) 3839 break; 3840 ret = copy_from_sockptr(&req_u.req3, optval, 3841 sizeof(req_u.req3)) ? 3842 -EINVAL : 0; 3843 break; 3844 } 3845 if (!ret) 3846 ret = packet_set_ring(sk, &req_u, 0, 3847 optname == PACKET_TX_RING); 3848 release_sock(sk); 3849 return ret; 3850 } 3851 case PACKET_COPY_THRESH: 3852 { 3853 int val; 3854 3855 if (optlen != sizeof(val)) 3856 return -EINVAL; 3857 if (copy_from_sockptr(&val, optval, sizeof(val))) 3858 return -EFAULT; 3859 3860 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3861 return 0; 3862 } 3863 case PACKET_VERSION: 3864 { 3865 int val; 3866 3867 if (optlen != sizeof(val)) 3868 return -EINVAL; 3869 if (copy_from_sockptr(&val, optval, sizeof(val))) 3870 return -EFAULT; 3871 switch (val) { 3872 case TPACKET_V1: 3873 case TPACKET_V2: 3874 case TPACKET_V3: 3875 break; 3876 default: 3877 return -EINVAL; 3878 } 3879 lock_sock(sk); 3880 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3881 ret = -EBUSY; 3882 } else { 3883 po->tp_version = val; 3884 ret = 0; 3885 } 3886 release_sock(sk); 3887 return ret; 3888 } 3889 case PACKET_RESERVE: 3890 { 3891 unsigned int val; 3892 3893 if (optlen != sizeof(val)) 3894 return -EINVAL; 3895 if (copy_from_sockptr(&val, optval, sizeof(val))) 3896 return -EFAULT; 3897 if (val > INT_MAX) 3898 return -EINVAL; 3899 lock_sock(sk); 3900 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3901 ret = -EBUSY; 3902 } else { 3903 po->tp_reserve = val; 3904 ret = 0; 3905 } 3906 release_sock(sk); 3907 return ret; 3908 } 3909 case PACKET_LOSS: 3910 { 3911 unsigned int val; 3912 3913 if (optlen != sizeof(val)) 3914 return -EINVAL; 3915 if (copy_from_sockptr(&val, optval, sizeof(val))) 3916 return -EFAULT; 3917 3918 lock_sock(sk); 3919 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3920 ret = -EBUSY; 3921 } else { 3922 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3923 ret = 0; 3924 } 3925 release_sock(sk); 3926 return ret; 3927 } 3928 case PACKET_AUXDATA: 3929 { 3930 int val; 3931 3932 if (optlen < sizeof(val)) 3933 return -EINVAL; 3934 if (copy_from_sockptr(&val, optval, sizeof(val))) 3935 return -EFAULT; 3936 3937 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3938 return 0; 3939 } 3940 case PACKET_ORIGDEV: 3941 { 3942 int val; 3943 3944 if (optlen < sizeof(val)) 3945 return -EINVAL; 3946 if (copy_from_sockptr(&val, optval, sizeof(val))) 3947 return -EFAULT; 3948 3949 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 3950 return 0; 3951 } 3952 case PACKET_VNET_HDR: 3953 case PACKET_VNET_HDR_SZ: 3954 { 3955 int val, hdr_len; 3956 3957 if (sock->type != SOCK_RAW) 3958 return -EINVAL; 3959 if (optlen < sizeof(val)) 3960 return -EINVAL; 3961 if (copy_from_sockptr(&val, optval, sizeof(val))) 3962 return -EFAULT; 3963 3964 if (optname == PACKET_VNET_HDR_SZ) { 3965 if (val && val != sizeof(struct virtio_net_hdr) && 3966 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 3967 return -EINVAL; 3968 hdr_len = val; 3969 } else { 3970 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 3971 } 3972 lock_sock(sk); 3973 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3974 ret = -EBUSY; 3975 } else { 3976 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 3977 ret = 0; 3978 } 3979 release_sock(sk); 3980 return ret; 3981 } 3982 case PACKET_TIMESTAMP: 3983 { 3984 int val; 3985 3986 if (optlen != sizeof(val)) 3987 return -EINVAL; 3988 if (copy_from_sockptr(&val, optval, sizeof(val))) 3989 return -EFAULT; 3990 3991 WRITE_ONCE(po->tp_tstamp, val); 3992 return 0; 3993 } 3994 case PACKET_FANOUT: 3995 { 3996 struct fanout_args args = { 0 }; 3997 3998 if (optlen != sizeof(int) && optlen != sizeof(args)) 3999 return -EINVAL; 4000 if (copy_from_sockptr(&args, optval, optlen)) 4001 return -EFAULT; 4002 4003 return fanout_add(sk, &args); 4004 } 4005 case PACKET_FANOUT_DATA: 4006 { 4007 /* Paired with the WRITE_ONCE() in fanout_add() */ 4008 if (!READ_ONCE(po->fanout)) 4009 return -EINVAL; 4010 4011 return fanout_set_data(po, optval, optlen); 4012 } 4013 case PACKET_IGNORE_OUTGOING: 4014 { 4015 int val; 4016 4017 if (optlen != sizeof(val)) 4018 return -EINVAL; 4019 if (copy_from_sockptr(&val, optval, sizeof(val))) 4020 return -EFAULT; 4021 if (val < 0 || val > 1) 4022 return -EINVAL; 4023 4024 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4025 return 0; 4026 } 4027 case PACKET_TX_HAS_OFF: 4028 { 4029 unsigned int val; 4030 4031 if (optlen != sizeof(val)) 4032 return -EINVAL; 4033 if (copy_from_sockptr(&val, optval, sizeof(val))) 4034 return -EFAULT; 4035 4036 lock_sock(sk); 4037 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4038 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4039 4040 release_sock(sk); 4041 return 0; 4042 } 4043 case PACKET_QDISC_BYPASS: 4044 { 4045 int val; 4046 4047 if (optlen != sizeof(val)) 4048 return -EINVAL; 4049 if (copy_from_sockptr(&val, optval, sizeof(val))) 4050 return -EFAULT; 4051 4052 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4053 return 0; 4054 } 4055 default: 4056 return -ENOPROTOOPT; 4057 } 4058 } 4059 4060 static int packet_getsockopt(struct socket *sock, int level, int optname, 4061 sockopt_t *opt) 4062 { 4063 int len; 4064 int val, lv = sizeof(val); 4065 struct sock *sk = sock->sk; 4066 struct packet_sock *po = pkt_sk(sk); 4067 void *data = &val; 4068 union tpacket_stats_u st; 4069 struct tpacket_rollover_stats rstats; 4070 int drops; 4071 4072 if (level != SOL_PACKET) 4073 return -ENOPROTOOPT; 4074 4075 len = opt->optlen; 4076 4077 if (len < 0) 4078 return -EINVAL; 4079 4080 switch (optname) { 4081 case PACKET_STATISTICS: 4082 spin_lock_bh(&sk->sk_receive_queue.lock); 4083 memcpy(&st, &po->stats, sizeof(st)); 4084 memset(&po->stats, 0, sizeof(po->stats)); 4085 spin_unlock_bh(&sk->sk_receive_queue.lock); 4086 drops = atomic_xchg(&po->tp_drops, 0); 4087 4088 if (po->tp_version == TPACKET_V3) { 4089 lv = sizeof(struct tpacket_stats_v3); 4090 st.stats3.tp_drops = drops; 4091 st.stats3.tp_packets += drops; 4092 data = &st.stats3; 4093 } else { 4094 lv = sizeof(struct tpacket_stats); 4095 st.stats1.tp_drops = drops; 4096 st.stats1.tp_packets += drops; 4097 data = &st.stats1; 4098 } 4099 4100 break; 4101 case PACKET_AUXDATA: 4102 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4103 break; 4104 case PACKET_ORIGDEV: 4105 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4106 break; 4107 case PACKET_VNET_HDR: 4108 val = !!READ_ONCE(po->vnet_hdr_sz); 4109 break; 4110 case PACKET_VNET_HDR_SZ: 4111 val = READ_ONCE(po->vnet_hdr_sz); 4112 break; 4113 case PACKET_COPY_THRESH: 4114 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4115 break; 4116 case PACKET_VERSION: 4117 val = po->tp_version; 4118 break; 4119 case PACKET_HDRLEN: 4120 if (len > sizeof(int)) 4121 len = sizeof(int); 4122 if (len < sizeof(int)) 4123 return -EINVAL; 4124 if (copy_from_iter(&val, len, &opt->iter_in) != len) 4125 return -EFAULT; 4126 switch (val) { 4127 case TPACKET_V1: 4128 val = sizeof(struct tpacket_hdr); 4129 break; 4130 case TPACKET_V2: 4131 val = sizeof(struct tpacket2_hdr); 4132 break; 4133 case TPACKET_V3: 4134 val = sizeof(struct tpacket3_hdr); 4135 break; 4136 default: 4137 return -EINVAL; 4138 } 4139 break; 4140 case PACKET_RESERVE: 4141 val = po->tp_reserve; 4142 break; 4143 case PACKET_LOSS: 4144 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4145 break; 4146 case PACKET_TIMESTAMP: 4147 val = READ_ONCE(po->tp_tstamp); 4148 break; 4149 case PACKET_FANOUT: 4150 val = (po->fanout ? 4151 ((u32)po->fanout->id | 4152 ((u32)po->fanout->type << 16) | 4153 ((u32)po->fanout->flags << 24)) : 4154 0); 4155 break; 4156 case PACKET_IGNORE_OUTGOING: 4157 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4158 break; 4159 case PACKET_ROLLOVER_STATS: 4160 if (!po->rollover) 4161 return -EINVAL; 4162 rstats.tp_all = atomic_long_read(&po->rollover->num); 4163 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4164 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4165 data = &rstats; 4166 lv = sizeof(rstats); 4167 break; 4168 case PACKET_TX_HAS_OFF: 4169 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4170 break; 4171 case PACKET_QDISC_BYPASS: 4172 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4173 break; 4174 default: 4175 return -ENOPROTOOPT; 4176 } 4177 4178 if (len > lv) 4179 len = lv; 4180 opt->optlen = len; 4181 if (copy_to_iter(data, len, &opt->iter_out) != len) 4182 return -EFAULT; 4183 return 0; 4184 } 4185 4186 static int packet_notifier(struct notifier_block *this, 4187 unsigned long msg, void *ptr) 4188 { 4189 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4190 struct net *net = dev_net(dev); 4191 struct packet_mclist *ml, *tmp; 4192 LIST_HEAD(mclist); 4193 struct sock *sk; 4194 4195 rcu_read_lock(); 4196 sk_for_each_rcu(sk, &net->packet.sklist) { 4197 struct packet_sock *po = pkt_sk(sk); 4198 4199 switch (msg) { 4200 case NETDEV_UNREGISTER: 4201 if (po->mclist) 4202 packet_dev_mclist_delete(dev, &po->mclist, 4203 &mclist); 4204 fallthrough; 4205 4206 case NETDEV_DOWN: 4207 if (dev->ifindex == po->ifindex) { 4208 spin_lock(&po->bind_lock); 4209 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4210 __unregister_prot_hook(sk, false); 4211 sk->sk_err = ENETDOWN; 4212 if (!sock_flag(sk, SOCK_DEAD)) 4213 sk_error_report(sk); 4214 } 4215 if (msg == NETDEV_UNREGISTER) { 4216 packet_cached_dev_reset(po); 4217 WRITE_ONCE(po->ifindex, -1); 4218 netdev_put(po->prot_hook.dev, 4219 &po->prot_hook.dev_tracker); 4220 po->prot_hook.dev = NULL; 4221 } 4222 spin_unlock(&po->bind_lock); 4223 } 4224 break; 4225 case NETDEV_UP: 4226 if (dev->ifindex == po->ifindex) { 4227 spin_lock(&po->bind_lock); 4228 if (po->num) 4229 register_prot_hook(sk); 4230 spin_unlock(&po->bind_lock); 4231 } 4232 break; 4233 } 4234 } 4235 rcu_read_unlock(); 4236 4237 /* packet_dev_mc might grab instance locks so can't run under rcu */ 4238 list_for_each_entry_safe(ml, tmp, &mclist, remove_list) { 4239 packet_dev_mc(dev, ml, -1); 4240 kfree(ml); 4241 } 4242 4243 return NOTIFY_DONE; 4244 } 4245 4246 4247 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4248 unsigned long arg) 4249 { 4250 struct sock *sk = sock->sk; 4251 4252 switch (cmd) { 4253 case SIOCOUTQ: 4254 { 4255 int amount = sk_wmem_alloc_get(sk); 4256 4257 return put_user(amount, (int __user *)arg); 4258 } 4259 case SIOCINQ: 4260 { 4261 struct sk_buff *skb; 4262 int amount = 0; 4263 4264 spin_lock_bh(&sk->sk_receive_queue.lock); 4265 skb = skb_peek(&sk->sk_receive_queue); 4266 if (skb) 4267 amount = skb->len; 4268 spin_unlock_bh(&sk->sk_receive_queue.lock); 4269 return put_user(amount, (int __user *)arg); 4270 } 4271 #ifdef CONFIG_INET 4272 case SIOCADDRT: 4273 case SIOCDELRT: 4274 case SIOCDARP: 4275 case SIOCGARP: 4276 case SIOCSARP: 4277 case SIOCGIFADDR: 4278 case SIOCSIFADDR: 4279 case SIOCGIFBRDADDR: 4280 case SIOCSIFBRDADDR: 4281 case SIOCGIFNETMASK: 4282 case SIOCSIFNETMASK: 4283 case SIOCGIFDSTADDR: 4284 case SIOCSIFDSTADDR: 4285 case SIOCSIFFLAGS: 4286 return inet_dgram_ops.ioctl(sock, cmd, arg); 4287 #endif 4288 4289 default: 4290 return -ENOIOCTLCMD; 4291 } 4292 return 0; 4293 } 4294 4295 static __poll_t packet_poll(struct file *file, struct socket *sock, 4296 poll_table *wait) 4297 { 4298 struct sock *sk = sock->sk; 4299 struct packet_sock *po = pkt_sk(sk); 4300 __poll_t mask = datagram_poll(file, sock, wait); 4301 4302 spin_lock_bh(&sk->sk_receive_queue.lock); 4303 if (po->rx_ring.pg_vec) { 4304 if (!packet_previous_rx_frame(po, &po->rx_ring, 4305 TP_STATUS_KERNEL)) 4306 mask |= EPOLLIN | EPOLLRDNORM; 4307 } 4308 packet_rcv_try_clear_pressure(po); 4309 spin_unlock_bh(&sk->sk_receive_queue.lock); 4310 spin_lock_bh(&sk->sk_write_queue.lock); 4311 if (po->tx_ring.pg_vec) { 4312 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4313 mask |= EPOLLOUT | EPOLLWRNORM; 4314 } 4315 spin_unlock_bh(&sk->sk_write_queue.lock); 4316 return mask; 4317 } 4318 4319 4320 /* Dirty? Well, I still did not learn better way to account 4321 * for user mmaps. 4322 */ 4323 4324 static void packet_mm_open(struct vm_area_struct *vma) 4325 { 4326 struct file *file = vma->vm_file; 4327 struct socket *sock = file->private_data; 4328 struct sock *sk = sock->sk; 4329 4330 if (sk) 4331 atomic_long_inc(&pkt_sk(sk)->mapped); 4332 } 4333 4334 static void packet_mm_close(struct vm_area_struct *vma) 4335 { 4336 struct file *file = vma->vm_file; 4337 struct socket *sock = file->private_data; 4338 struct sock *sk = sock->sk; 4339 4340 if (sk) 4341 atomic_long_dec(&pkt_sk(sk)->mapped); 4342 } 4343 4344 static const struct vm_operations_struct packet_mmap_ops = { 4345 .open = packet_mm_open, 4346 .close = packet_mm_close, 4347 }; 4348 4349 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4350 unsigned int len) 4351 { 4352 int i; 4353 4354 for (i = 0; i < len; i++) { 4355 if (likely(pg_vec[i].buffer)) { 4356 if (is_vmalloc_addr(pg_vec[i].buffer)) 4357 vfree(pg_vec[i].buffer); 4358 else 4359 free_pages((unsigned long)pg_vec[i].buffer, 4360 order); 4361 pg_vec[i].buffer = NULL; 4362 } 4363 } 4364 kfree(pg_vec); 4365 } 4366 4367 static char *alloc_one_pg_vec_page(unsigned long order) 4368 { 4369 char *buffer; 4370 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4371 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4372 4373 buffer = (char *) __get_free_pages(gfp_flags, order); 4374 if (buffer) 4375 return buffer; 4376 4377 /* __get_free_pages failed, fall back to vmalloc */ 4378 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4379 if (buffer) 4380 return buffer; 4381 4382 /* vmalloc failed, lets dig into swap here */ 4383 gfp_flags &= ~__GFP_NORETRY; 4384 buffer = (char *) __get_free_pages(gfp_flags, order); 4385 if (buffer) 4386 return buffer; 4387 4388 /* complete and utter failure */ 4389 return NULL; 4390 } 4391 4392 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4393 { 4394 unsigned int block_nr = req->tp_block_nr; 4395 struct pgv *pg_vec; 4396 int i; 4397 4398 pg_vec = kzalloc_objs(struct pgv, block_nr, GFP_KERNEL | __GFP_NOWARN); 4399 if (unlikely(!pg_vec)) 4400 goto out; 4401 4402 for (i = 0; i < block_nr; i++) { 4403 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4404 if (unlikely(!pg_vec[i].buffer)) 4405 goto out_free_pgvec; 4406 } 4407 4408 out: 4409 return pg_vec; 4410 4411 out_free_pgvec: 4412 free_pg_vec(pg_vec, order, block_nr); 4413 pg_vec = NULL; 4414 goto out; 4415 } 4416 4417 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4418 int closing, int tx_ring) 4419 { 4420 struct pgv *pg_vec = NULL; 4421 struct packet_sock *po = pkt_sk(sk); 4422 unsigned long *rx_owner_map = NULL; 4423 int was_running, order = 0; 4424 struct packet_ring_buffer *rb; 4425 struct sk_buff_head *rb_queue; 4426 __be16 num; 4427 int err; 4428 /* Added to avoid minimal code churn */ 4429 struct tpacket_req *req = &req_u->req; 4430 4431 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4432 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4433 4434 err = -EBUSY; 4435 if (!closing) { 4436 if (atomic_long_read(&po->mapped)) 4437 goto out; 4438 if (packet_read_pending(rb)) 4439 goto out; 4440 } 4441 4442 if (req->tp_block_nr) { 4443 unsigned int min_frame_size; 4444 4445 /* Sanity tests and some calculations */ 4446 err = -EBUSY; 4447 if (unlikely(rb->pg_vec)) 4448 goto out; 4449 4450 switch (po->tp_version) { 4451 case TPACKET_V1: 4452 po->tp_hdrlen = TPACKET_HDRLEN; 4453 break; 4454 case TPACKET_V2: 4455 po->tp_hdrlen = TPACKET2_HDRLEN; 4456 break; 4457 case TPACKET_V3: 4458 po->tp_hdrlen = TPACKET3_HDRLEN; 4459 break; 4460 } 4461 4462 err = -EINVAL; 4463 if (unlikely((int)req->tp_block_size <= 0)) 4464 goto out; 4465 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4466 goto out; 4467 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4468 if (po->tp_version >= TPACKET_V3 && 4469 req->tp_block_size < 4470 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4471 goto out; 4472 if (unlikely(req->tp_frame_size < min_frame_size)) 4473 goto out; 4474 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4475 goto out; 4476 4477 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4478 if (unlikely(rb->frames_per_block == 0)) 4479 goto out; 4480 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4481 goto out; 4482 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4483 req->tp_frame_nr)) 4484 goto out; 4485 4486 err = -ENOMEM; 4487 order = get_order(req->tp_block_size); 4488 pg_vec = alloc_pg_vec(req, order); 4489 if (unlikely(!pg_vec)) 4490 goto out; 4491 switch (po->tp_version) { 4492 case TPACKET_V3: 4493 /* Block transmit is not supported yet */ 4494 if (!tx_ring) { 4495 init_prb_bdqc(po, rb, pg_vec, req_u); 4496 } else { 4497 struct tpacket_req3 *req3 = &req_u->req3; 4498 4499 if (req3->tp_retire_blk_tov || 4500 req3->tp_sizeof_priv || 4501 req3->tp_feature_req_word) { 4502 err = -EINVAL; 4503 goto out_free_pg_vec; 4504 } 4505 } 4506 break; 4507 default: 4508 if (!tx_ring) { 4509 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4510 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4511 if (!rx_owner_map) 4512 goto out_free_pg_vec; 4513 } 4514 break; 4515 } 4516 } 4517 /* Done */ 4518 else { 4519 err = -EINVAL; 4520 if (unlikely(req->tp_frame_nr)) 4521 goto out; 4522 } 4523 4524 4525 /* Detach socket from network */ 4526 spin_lock(&po->bind_lock); 4527 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4528 num = po->num; 4529 WRITE_ONCE(po->num, 0); 4530 if (was_running) 4531 __unregister_prot_hook(sk, false); 4532 4533 spin_unlock(&po->bind_lock); 4534 4535 synchronize_net(); 4536 4537 err = -EBUSY; 4538 mutex_lock(&po->pg_vec_lock); 4539 if (closing || atomic_long_read(&po->mapped) == 0) { 4540 err = 0; 4541 spin_lock_bh(&rb_queue->lock); 4542 swap(rb->pg_vec, pg_vec); 4543 if (po->tp_version <= TPACKET_V2) 4544 swap(rb->rx_owner_map, rx_owner_map); 4545 rb->frame_max = (req->tp_frame_nr - 1); 4546 rb->head = 0; 4547 rb->frame_size = req->tp_frame_size; 4548 spin_unlock_bh(&rb_queue->lock); 4549 4550 swap(rb->pg_vec_order, order); 4551 swap(rb->pg_vec_len, req->tp_block_nr); 4552 4553 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4554 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4555 tpacket_rcv : packet_rcv; 4556 skb_queue_purge(rb_queue); 4557 if (atomic_long_read(&po->mapped)) 4558 pr_err("packet_mmap: vma is busy: %ld\n", 4559 atomic_long_read(&po->mapped)); 4560 } 4561 mutex_unlock(&po->pg_vec_lock); 4562 4563 spin_lock(&po->bind_lock); 4564 WRITE_ONCE(po->num, num); 4565 /* 4566 * NETDEV_UNREGISTER may have invalidated the binding while bind_lock 4567 * was dropped above. Do not re-add a fanout hook to a dead device. 4568 */ 4569 if (was_running && READ_ONCE(po->ifindex) != -1) 4570 register_prot_hook(sk); 4571 4572 spin_unlock(&po->bind_lock); 4573 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4574 /* Because we don't support block-based V3 on tx-ring */ 4575 if (!tx_ring) 4576 prb_shutdown_retire_blk_timer(po, rb_queue); 4577 } 4578 4579 out_free_pg_vec: 4580 if (pg_vec) { 4581 bitmap_free(rx_owner_map); 4582 free_pg_vec(pg_vec, order, req->tp_block_nr); 4583 } 4584 out: 4585 return err; 4586 } 4587 4588 static int packet_mmap(struct file *file, struct socket *sock, 4589 struct vm_area_struct *vma) 4590 { 4591 struct sock *sk = sock->sk; 4592 struct packet_sock *po = pkt_sk(sk); 4593 unsigned long size, expected_size; 4594 struct packet_ring_buffer *rb; 4595 unsigned long start; 4596 int err = -EINVAL; 4597 int i; 4598 4599 if (vma->vm_pgoff) 4600 return -EINVAL; 4601 4602 mutex_lock(&po->pg_vec_lock); 4603 4604 expected_size = 0; 4605 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4606 if (rb->pg_vec) { 4607 expected_size += rb->pg_vec_len 4608 * rb->pg_vec_pages 4609 * PAGE_SIZE; 4610 } 4611 } 4612 4613 if (expected_size == 0) 4614 goto out; 4615 4616 size = vma->vm_end - vma->vm_start; 4617 if (size != expected_size) 4618 goto out; 4619 4620 start = vma->vm_start; 4621 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4622 if (rb->pg_vec == NULL) 4623 continue; 4624 4625 for (i = 0; i < rb->pg_vec_len; i++) { 4626 struct page *page; 4627 void *kaddr = rb->pg_vec[i].buffer; 4628 int pg_num; 4629 4630 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4631 page = pgv_to_page(kaddr); 4632 err = vm_insert_page(vma, start, page); 4633 if (unlikely(err)) 4634 goto out; 4635 start += PAGE_SIZE; 4636 kaddr += PAGE_SIZE; 4637 } 4638 } 4639 } 4640 4641 atomic_long_inc(&po->mapped); 4642 vma->vm_ops = &packet_mmap_ops; 4643 err = 0; 4644 4645 out: 4646 mutex_unlock(&po->pg_vec_lock); 4647 return err; 4648 } 4649 4650 static const struct proto_ops packet_ops_spkt = { 4651 .family = PF_PACKET, 4652 .owner = THIS_MODULE, 4653 .release = packet_release, 4654 .bind = packet_bind_spkt, 4655 .connect = sock_no_connect, 4656 .socketpair = sock_no_socketpair, 4657 .accept = sock_no_accept, 4658 .getname = packet_getname_spkt, 4659 .poll = datagram_poll, 4660 .ioctl = packet_ioctl, 4661 .gettstamp = sock_gettstamp, 4662 .listen = sock_no_listen, 4663 .shutdown = sock_no_shutdown, 4664 .sendmsg = packet_sendmsg_spkt, 4665 .recvmsg = packet_recvmsg, 4666 .mmap = sock_no_mmap, 4667 }; 4668 4669 static const struct proto_ops packet_ops = { 4670 .family = PF_PACKET, 4671 .owner = THIS_MODULE, 4672 .release = packet_release, 4673 .bind = packet_bind, 4674 .connect = sock_no_connect, 4675 .socketpair = sock_no_socketpair, 4676 .accept = sock_no_accept, 4677 .getname = packet_getname, 4678 .poll = packet_poll, 4679 .ioctl = packet_ioctl, 4680 .gettstamp = sock_gettstamp, 4681 .listen = sock_no_listen, 4682 .shutdown = sock_no_shutdown, 4683 .setsockopt = packet_setsockopt, 4684 .getsockopt_iter = packet_getsockopt, 4685 .sendmsg = packet_sendmsg, 4686 .recvmsg = packet_recvmsg, 4687 .mmap = packet_mmap, 4688 }; 4689 4690 static const struct net_proto_family packet_family_ops = { 4691 .family = PF_PACKET, 4692 .create = packet_create, 4693 .owner = THIS_MODULE, 4694 }; 4695 4696 static struct notifier_block packet_netdev_notifier = { 4697 .notifier_call = packet_notifier, 4698 }; 4699 4700 #ifdef CONFIG_PROC_FS 4701 4702 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4703 __acquires(RCU) 4704 { 4705 struct net *net = seq_file_net(seq); 4706 4707 rcu_read_lock(); 4708 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4709 } 4710 4711 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4712 { 4713 struct net *net = seq_file_net(seq); 4714 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4715 } 4716 4717 static void packet_seq_stop(struct seq_file *seq, void *v) 4718 __releases(RCU) 4719 { 4720 rcu_read_unlock(); 4721 } 4722 4723 static int packet_seq_show(struct seq_file *seq, void *v) 4724 { 4725 if (v == SEQ_START_TOKEN) 4726 seq_printf(seq, 4727 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4728 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4729 else { 4730 struct sock *s = sk_entry(v); 4731 const struct packet_sock *po = pkt_sk(s); 4732 4733 seq_printf(seq, 4734 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6llu\n", 4735 s, 4736 refcount_read(&s->sk_refcnt), 4737 s->sk_type, 4738 ntohs(READ_ONCE(po->num)), 4739 READ_ONCE(po->ifindex), 4740 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4741 atomic_read(&s->sk_rmem_alloc), 4742 from_kuid_munged(seq_user_ns(seq), sk_uid(s)), 4743 sock_i_ino(s)); 4744 } 4745 4746 return 0; 4747 } 4748 4749 static const struct seq_operations packet_seq_ops = { 4750 .start = packet_seq_start, 4751 .next = packet_seq_next, 4752 .stop = packet_seq_stop, 4753 .show = packet_seq_show, 4754 }; 4755 #endif 4756 4757 static int __net_init packet_net_init(struct net *net) 4758 { 4759 mutex_init(&net->packet.sklist_lock); 4760 INIT_HLIST_HEAD(&net->packet.sklist); 4761 4762 #ifdef CONFIG_PROC_FS 4763 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4764 sizeof(struct seq_net_private))) 4765 return -ENOMEM; 4766 #endif /* CONFIG_PROC_FS */ 4767 4768 return 0; 4769 } 4770 4771 static void __net_exit packet_net_exit(struct net *net) 4772 { 4773 remove_proc_entry("packet", net->proc_net); 4774 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4775 } 4776 4777 static struct pernet_operations packet_net_ops = { 4778 .init = packet_net_init, 4779 .exit = packet_net_exit, 4780 }; 4781 4782 4783 static void __exit packet_exit(void) 4784 { 4785 sock_unregister(PF_PACKET); 4786 proto_unregister(&packet_proto); 4787 unregister_netdevice_notifier(&packet_netdev_notifier); 4788 unregister_pernet_subsys(&packet_net_ops); 4789 } 4790 4791 static int __init packet_init(void) 4792 { 4793 int rc; 4794 4795 rc = register_pernet_subsys(&packet_net_ops); 4796 if (rc) 4797 goto out; 4798 rc = register_netdevice_notifier(&packet_netdev_notifier); 4799 if (rc) 4800 goto out_pernet; 4801 rc = proto_register(&packet_proto, 0); 4802 if (rc) 4803 goto out_notifier; 4804 rc = sock_register(&packet_family_ops); 4805 if (rc) 4806 goto out_proto; 4807 4808 return 0; 4809 4810 out_proto: 4811 proto_unregister(&packet_proto); 4812 out_notifier: 4813 unregister_netdevice_notifier(&packet_netdev_notifier); 4814 out_pernet: 4815 unregister_pernet_subsys(&packet_net_ops); 4816 out: 4817 return rc; 4818 } 4819 4820 module_init(packet_init); 4821 module_exit(packet_exit); 4822 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4823 MODULE_LICENSE("GPL"); 4824 MODULE_ALIAS_NETPROTO(PF_PACKET); 4825