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 #include <linux/workqueue.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 #include <linux/bpf.h> 96 #include <net/compat.h> 97 #include <linux/netfilter_netdev.h> 98 99 #include "internal.h" 100 101 /* 102 Assumptions: 103 - If the device has no dev->header_ops->create, there is no LL header 104 visible above the device. In this case, its hard_header_len should be 0. 105 The device may prepend its own header internally. In this case, its 106 needed_headroom should be set to the space needed for it to add its 107 internal header. 108 For example, a WiFi driver pretending to be an Ethernet driver should 109 set its hard_header_len to be the Ethernet header length, and set its 110 needed_headroom to be (the real WiFi header length - the fake Ethernet 111 header length). 112 - packet socket receives packets with pulled ll header, 113 so that SOCK_RAW should push it back. 114 115 On receive: 116 ----------- 117 118 Incoming, dev_has_header(dev) == true 119 mac_header -> ll header 120 data -> data 121 122 Outgoing, dev_has_header(dev) == true 123 mac_header -> ll header 124 data -> ll header 125 126 Incoming, dev_has_header(dev) == false 127 mac_header -> data 128 However drivers often make it point to the ll header. 129 This is incorrect because the ll header should be invisible to us. 130 data -> data 131 132 Outgoing, dev_has_header(dev) == false 133 mac_header -> data. ll header is invisible to us. 134 data -> data 135 136 Resume 137 If dev_has_header(dev) == false we are unable to restore the ll header, 138 because it is invisible to us. 139 140 141 On transmit: 142 ------------ 143 144 dev_has_header(dev) == true 145 mac_header -> ll header 146 data -> ll header 147 148 dev_has_header(dev) == false (ll header is invisible to us) 149 mac_header -> data 150 data -> data 151 152 We should set network_header on output to the correct position, 153 packet classifier depends on it. 154 */ 155 156 /* Private packet socket structures. */ 157 158 /* identical to struct packet_mreq except it has 159 * a longer address field. 160 */ 161 struct packet_mreq_max { 162 int mr_ifindex; 163 unsigned short mr_type; 164 unsigned short mr_alen; 165 unsigned char mr_address[MAX_ADDR_LEN]; 166 }; 167 168 union tpacket_uhdr { 169 struct tpacket_hdr *h1; 170 struct tpacket2_hdr *h2; 171 struct tpacket3_hdr *h3; 172 void *raw; 173 }; 174 175 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 176 int closing, int tx_ring); 177 178 #define V3_ALIGNMENT (8) 179 180 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 181 182 #define BLK_PLUS_PRIV(sz_of_priv) \ 183 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 184 185 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 186 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 187 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 188 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 189 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 190 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 191 192 struct packet_sock; 193 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 194 struct packet_type *pt, struct net_device *orig_dev); 195 196 static void *packet_previous_frame(struct packet_sock *po, 197 struct packet_ring_buffer *rb, 198 int status); 199 static void packet_increment_head(struct packet_ring_buffer *buff); 200 static int prb_curr_blk_in_use(struct tpacket_block_desc *); 201 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 202 struct packet_sock *); 203 static void prb_retire_current_block(struct tpacket_kbdq_core *, 204 struct packet_sock *, unsigned int status); 205 static int prb_queue_frozen(struct tpacket_kbdq_core *); 206 static void prb_open_block(struct tpacket_kbdq_core *, 207 struct tpacket_block_desc *); 208 static enum hrtimer_restart prb_retire_rx_blk_timer_expired(struct hrtimer *); 209 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 210 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 211 struct tpacket3_hdr *); 212 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 213 struct tpacket3_hdr *); 214 static void packet_flush_mclist(struct sock *sk); 215 static u16 packet_pick_tx_queue(struct sk_buff *skb); 216 217 struct packet_skb_cb { 218 union { 219 struct sockaddr_pkt pkt; 220 union { 221 /* Trick: alias skb original length with 222 * ll.sll_family and ll.protocol in order 223 * to save room. 224 */ 225 unsigned int origlen; 226 struct sockaddr_ll ll; 227 }; 228 } sa; 229 }; 230 231 #define vio_le() virtio_legacy_is_little_endian() 232 233 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 234 235 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 236 #define GET_PBLOCK_DESC(x, bid) \ 237 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 238 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 239 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 240 #define GET_NEXT_PRB_BLK_NUM(x) \ 241 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 242 ((x)->kactive_blk_num+1) : 0) 243 244 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 245 static void __fanout_link(struct sock *sk, struct packet_sock *po); 246 247 #ifdef CONFIG_NETFILTER_EGRESS 248 static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb) 249 { 250 struct sk_buff *next, *head = NULL, *tail; 251 int rc; 252 253 rcu_read_lock(); 254 for (; skb != NULL; skb = next) { 255 next = skb->next; 256 skb_mark_not_on_list(skb); 257 258 if (!nf_hook_egress(skb, &rc, skb->dev)) 259 continue; 260 261 if (!head) 262 head = skb; 263 else 264 tail->next = skb; 265 266 tail = skb; 267 } 268 rcu_read_unlock(); 269 270 return head; 271 } 272 #endif 273 274 static int packet_xmit(const struct packet_sock *po, struct sk_buff *skb) 275 { 276 if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS)) 277 return dev_queue_xmit(skb); 278 279 #ifdef CONFIG_NETFILTER_EGRESS 280 if (nf_hook_egress_active()) { 281 skb = nf_hook_direct_egress(skb); 282 if (!skb) 283 return NET_XMIT_DROP; 284 } 285 #endif 286 return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); 287 } 288 289 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 290 { 291 struct net_device *dev; 292 293 rcu_read_lock(); 294 dev = rcu_dereference(po->cached_dev); 295 dev_hold(dev); 296 rcu_read_unlock(); 297 298 return dev; 299 } 300 301 static void packet_cached_dev_assign(struct packet_sock *po, 302 struct net_device *dev) 303 { 304 rcu_assign_pointer(po->cached_dev, dev); 305 } 306 307 static void packet_cached_dev_reset(struct packet_sock *po) 308 { 309 RCU_INIT_POINTER(po->cached_dev, NULL); 310 } 311 312 static u16 packet_pick_tx_queue(struct sk_buff *skb) 313 { 314 struct net_device *dev = skb->dev; 315 const struct net_device_ops *ops = dev->netdev_ops; 316 int cpu = raw_smp_processor_id(); 317 u16 queue_index; 318 319 #ifdef CONFIG_XPS 320 skb->sender_cpu = cpu + 1; 321 #endif 322 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues); 323 if (ops->ndo_select_queue) { 324 queue_index = ops->ndo_select_queue(dev, skb, NULL); 325 queue_index = netdev_cap_txqueue(dev, queue_index); 326 } else { 327 queue_index = netdev_pick_tx(dev, skb, NULL); 328 } 329 330 return queue_index; 331 } 332 333 /* __register_prot_hook must be invoked through register_prot_hook 334 * or from a context in which asynchronous accesses to the packet 335 * socket is not possible (packet_create()). 336 */ 337 static void __register_prot_hook(struct sock *sk) 338 { 339 struct packet_sock *po = pkt_sk(sk); 340 341 if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 342 if (po->fanout) 343 __fanout_link(sk, po); 344 else 345 dev_add_pack(&po->prot_hook); 346 347 sock_hold(sk); 348 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1); 349 } 350 } 351 352 static void register_prot_hook(struct sock *sk) 353 { 354 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock); 355 __register_prot_hook(sk); 356 } 357 358 /* If the sync parameter is true, we will temporarily drop 359 * the po->bind_lock and do a synchronize_net to make sure no 360 * asynchronous packet processing paths still refer to the elements 361 * of po->prot_hook. If the sync parameter is false, it is the 362 * callers responsibility to take care of this. 363 */ 364 static void __unregister_prot_hook(struct sock *sk, bool sync) 365 { 366 struct packet_sock *po = pkt_sk(sk); 367 368 lockdep_assert_held_once(&po->bind_lock); 369 370 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0); 371 372 if (po->fanout) 373 __fanout_unlink(sk, po); 374 else 375 __dev_remove_pack(&po->prot_hook); 376 377 __sock_put(sk); 378 379 if (sync) { 380 spin_unlock(&po->bind_lock); 381 synchronize_net(); 382 spin_lock(&po->bind_lock); 383 } 384 } 385 386 static void unregister_prot_hook(struct sock *sk, bool sync) 387 { 388 struct packet_sock *po = pkt_sk(sk); 389 390 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) 391 __unregister_prot_hook(sk, sync); 392 } 393 394 static inline struct page * __pure pgv_to_page(void *addr) 395 { 396 if (is_vmalloc_addr(addr)) 397 return vmalloc_to_page(addr); 398 return virt_to_page(addr); 399 } 400 401 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 402 { 403 union tpacket_uhdr h; 404 405 /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */ 406 407 h.raw = frame; 408 switch (po->tp_version) { 409 case TPACKET_V1: 410 WRITE_ONCE(h.h1->tp_status, status); 411 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 412 break; 413 case TPACKET_V2: 414 WRITE_ONCE(h.h2->tp_status, status); 415 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 416 break; 417 case TPACKET_V3: 418 WRITE_ONCE(h.h3->tp_status, status); 419 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 420 break; 421 default: 422 WARN(1, "TPACKET version not supported.\n"); 423 BUG(); 424 } 425 426 smp_wmb(); 427 } 428 429 static int __packet_get_status(const struct packet_sock *po, void *frame) 430 { 431 union tpacket_uhdr h; 432 433 smp_rmb(); 434 435 /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */ 436 437 h.raw = frame; 438 switch (po->tp_version) { 439 case TPACKET_V1: 440 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 441 return READ_ONCE(h.h1->tp_status); 442 case TPACKET_V2: 443 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 444 return READ_ONCE(h.h2->tp_status); 445 case TPACKET_V3: 446 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 447 return READ_ONCE(h.h3->tp_status); 448 default: 449 WARN(1, "TPACKET version not supported.\n"); 450 BUG(); 451 return 0; 452 } 453 } 454 455 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, 456 unsigned int flags) 457 { 458 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 459 460 if (shhwtstamps && 461 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 462 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts)) 463 return TP_STATUS_TS_RAW_HARDWARE; 464 465 if ((flags & SOF_TIMESTAMPING_SOFTWARE) && 466 ktime_to_timespec64_cond(skb_tstamp(skb), ts)) 467 return TP_STATUS_TS_SOFTWARE; 468 469 return 0; 470 } 471 472 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 473 struct sk_buff *skb) 474 { 475 union tpacket_uhdr h; 476 struct timespec64 ts; 477 __u32 ts_status; 478 479 if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp)))) 480 return 0; 481 482 h.raw = frame; 483 /* 484 * versions 1 through 3 overflow the timestamps in y2106, since they 485 * all store the seconds in a 32-bit unsigned integer. 486 * If we create a version 4, that should have a 64-bit timestamp, 487 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit 488 * nanoseconds. 489 */ 490 switch (po->tp_version) { 491 case TPACKET_V1: 492 h.h1->tp_sec = ts.tv_sec; 493 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 494 break; 495 case TPACKET_V2: 496 h.h2->tp_sec = ts.tv_sec; 497 h.h2->tp_nsec = ts.tv_nsec; 498 break; 499 case TPACKET_V3: 500 h.h3->tp_sec = ts.tv_sec; 501 h.h3->tp_nsec = ts.tv_nsec; 502 break; 503 default: 504 WARN(1, "TPACKET version not supported.\n"); 505 BUG(); 506 } 507 508 /* one flush is safe, as both fields always lie on the same cacheline */ 509 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 510 smp_wmb(); 511 512 return ts_status; 513 } 514 515 static void *packet_lookup_frame(const struct packet_sock *po, 516 const struct packet_ring_buffer *rb, 517 unsigned int position, 518 int status) 519 { 520 unsigned int pg_vec_pos, frame_offset; 521 union tpacket_uhdr h; 522 523 pg_vec_pos = position / rb->frames_per_block; 524 frame_offset = position % rb->frames_per_block; 525 526 h.raw = rb->pg_vec[pg_vec_pos].buffer + 527 (frame_offset * rb->frame_size); 528 529 if (status != __packet_get_status(po, h.raw)) 530 return NULL; 531 532 return h.raw; 533 } 534 535 static void *packet_current_frame(struct packet_sock *po, 536 struct packet_ring_buffer *rb, 537 int status) 538 { 539 return packet_lookup_frame(po, rb, rb->head, status); 540 } 541 542 static u16 vlan_get_tci(const struct sk_buff *skb, struct net_device *dev) 543 { 544 struct vlan_hdr vhdr, *vh; 545 unsigned int header_len; 546 547 if (!dev) 548 return 0; 549 550 /* In the SOCK_DGRAM scenario, skb data starts at the network 551 * protocol, which is after the VLAN headers. The outer VLAN 552 * header is at the hard_header_len offset in non-variable 553 * length link layer headers. If it's a VLAN device, the 554 * min_header_len should be used to exclude the VLAN header 555 * size. 556 */ 557 if (dev->min_header_len == dev->hard_header_len) 558 header_len = dev->hard_header_len; 559 else if (is_vlan_dev(dev)) 560 header_len = dev->min_header_len; 561 else 562 return 0; 563 564 vh = skb_header_pointer(skb, skb_mac_offset(skb) + header_len, 565 sizeof(vhdr), &vhdr); 566 if (unlikely(!vh)) 567 return 0; 568 569 return ntohs(vh->h_vlan_TCI); 570 } 571 572 static __be16 vlan_get_protocol_dgram(const struct sk_buff *skb) 573 { 574 __be16 proto = skb->protocol; 575 576 if (unlikely(eth_type_vlan(proto))) 577 proto = vlan_get_protocol_offset_inline(skb, proto, 578 skb_mac_offset(skb), 579 NULL); 580 581 return proto; 582 } 583 584 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 585 struct sk_buff_head *rb_queue) 586 { 587 struct tpacket_kbdq_core *pkc; 588 589 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 590 hrtimer_cancel(&pkc->retire_blk_timer); 591 } 592 593 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 594 int blk_size_in_bytes) 595 { 596 struct net_device *dev; 597 unsigned int mbits, div; 598 struct ethtool_link_ksettings ecmd; 599 int err; 600 601 rtnl_lock(); 602 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 603 if (unlikely(!dev)) { 604 rtnl_unlock(); 605 return DEFAULT_PRB_RETIRE_TOV; 606 } 607 err = __ethtool_get_link_ksettings(dev, &ecmd); 608 rtnl_unlock(); 609 if (err) 610 return DEFAULT_PRB_RETIRE_TOV; 611 612 /* If the link speed is so slow you don't really 613 * need to worry about perf anyways 614 */ 615 if (ecmd.base.speed < SPEED_1000 || 616 ecmd.base.speed == SPEED_UNKNOWN) 617 return DEFAULT_PRB_RETIRE_TOV; 618 619 div = ecmd.base.speed / 1000; 620 mbits = (u64)blk_size_in_bytes * 8 / (1024 * 1024); 621 622 if (div) 623 mbits /= div; 624 625 if (div) 626 return mbits + 1; 627 return mbits; 628 } 629 630 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 631 union tpacket_req_u *req_u) 632 { 633 p1->feature_req_word = req_u->req3.tp_feature_req_word; 634 } 635 636 static void init_prb_bdqc(struct packet_sock *po, 637 struct packet_ring_buffer *rb, 638 struct pgv *pg_vec, 639 union tpacket_req_u *req_u) 640 { 641 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 642 struct tpacket_block_desc *pbd; 643 644 memset(p1, 0x0, sizeof(*p1)); 645 646 p1->knxt_seq_num = 1; 647 p1->pkbdq = pg_vec; 648 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 649 p1->pkblk_start = pg_vec[0].buffer; 650 p1->kblk_size = req_u->req3.tp_block_size; 651 p1->knum_blocks = req_u->req3.tp_block_nr; 652 p1->hdrlen = po->tp_hdrlen; 653 p1->version = po->tp_version; 654 po->stats.stats3.tp_freeze_q_cnt = 0; 655 if (req_u->req3.tp_retire_blk_tov) 656 p1->interval_ktime = ms_to_ktime(req_u->req3.tp_retire_blk_tov); 657 else 658 p1->interval_ktime = ms_to_ktime(prb_calc_retire_blk_tmo(po, 659 req_u->req3.tp_block_size)); 660 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 661 rwlock_init(&p1->blk_fill_in_prog_lock); 662 663 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 664 prb_init_ft_ops(p1, req_u); 665 hrtimer_setup(&p1->retire_blk_timer, prb_retire_rx_blk_timer_expired, 666 CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); 667 hrtimer_start(&p1->retire_blk_timer, p1->interval_ktime, 668 HRTIMER_MODE_REL_SOFT); 669 prb_open_block(p1, pbd); 670 } 671 672 /* 673 * With a 1MB block-size, on a 1Gbps line, it will take 674 * i) ~8 ms to fill a block + ii) memcpy etc. 675 * In this cut we are not accounting for the memcpy time. 676 * 677 * Since the tmo granularity is in msecs, it is not too expensive 678 * to refresh the timer, lets say every '8' msecs. 679 * Either the user can set the 'tmo' or we can derive it based on 680 * a) line-speed and b) block-size. 681 * prb_calc_retire_blk_tmo() calculates the tmo. 682 */ 683 static enum hrtimer_restart prb_retire_rx_blk_timer_expired(struct hrtimer *t) 684 { 685 struct packet_sock *po = 686 timer_container_of(po, t, rx_ring.prb_bdqc.retire_blk_timer); 687 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 688 unsigned int frozen; 689 struct tpacket_block_desc *pbd; 690 691 spin_lock(&po->sk.sk_receive_queue.lock); 692 693 frozen = prb_queue_frozen(pkc); 694 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 695 696 /* We only need to plug the race when the block is partially filled. 697 * tpacket_rcv: 698 * lock(); increment BLOCK_NUM_PKTS; unlock() 699 * copy_bits() is in progress ... 700 * timer fires on other cpu: 701 * we can't retire the current block because copy_bits 702 * is in progress. 703 * 704 */ 705 if (BLOCK_NUM_PKTS(pbd)) { 706 /* Waiting for skb_copy_bits to finish... */ 707 write_lock(&pkc->blk_fill_in_prog_lock); 708 write_unlock(&pkc->blk_fill_in_prog_lock); 709 } 710 711 if (!frozen) { 712 if (BLOCK_NUM_PKTS(pbd)) { 713 /* Not an empty block. Need retire the block. */ 714 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 715 prb_dispatch_next_block(pkc, po); 716 } 717 } else { 718 /* Case 1. Queue was frozen because user-space was 719 * lagging behind. 720 */ 721 if (!prb_curr_blk_in_use(pbd)) { 722 /* Case 2. queue was frozen,user-space caught up, 723 * now the link went idle && the timer fired. 724 * We don't have a block to close.So we open this 725 * block and restart the timer. 726 * opening a block thaws the queue,restarts timer 727 * Thawing/timer-refresh is a side effect. 728 */ 729 prb_open_block(pkc, pbd); 730 } 731 } 732 733 hrtimer_forward_now(&pkc->retire_blk_timer, pkc->interval_ktime); 734 spin_unlock(&po->sk.sk_receive_queue.lock); 735 return HRTIMER_RESTART; 736 } 737 738 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 739 struct tpacket_block_desc *pbd1, __u32 status) 740 { 741 /* Flush everything minus the block header */ 742 743 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 744 u8 *start, *end; 745 746 start = (u8 *)pbd1; 747 748 /* Skip the block header(we know header WILL fit in 4K) */ 749 start += PAGE_SIZE; 750 751 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 752 for (; start < end; start += PAGE_SIZE) 753 flush_dcache_page(pgv_to_page(start)); 754 755 smp_wmb(); 756 #endif 757 758 /* Now update the block status. */ 759 760 BLOCK_STATUS(pbd1) = status; 761 762 /* Flush the block header */ 763 764 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 765 start = (u8 *)pbd1; 766 flush_dcache_page(pgv_to_page(start)); 767 768 smp_wmb(); 769 #endif 770 } 771 772 /* 773 * Side effect: 774 * 775 * 1) flush the block 776 * 2) Increment active_blk_num 777 * 778 * Note:We DONT refresh the timer on purpose. 779 * Because almost always the next block will be opened. 780 */ 781 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 782 struct tpacket_block_desc *pbd1, 783 struct packet_sock *po, unsigned int stat) 784 { 785 __u32 status = TP_STATUS_USER | stat; 786 787 struct tpacket3_hdr *last_pkt; 788 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 789 struct sock *sk = &po->sk; 790 791 if (atomic_read(&po->tp_drops)) 792 status |= TP_STATUS_LOSING; 793 794 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 795 last_pkt->tp_next_offset = 0; 796 797 /* Get the ts of the last pkt */ 798 if (BLOCK_NUM_PKTS(pbd1)) { 799 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 800 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 801 } else { 802 /* Ok, we tmo'd - so get the current time. 803 * 804 * It shouldn't really happen as we don't close empty 805 * blocks. See prb_retire_rx_blk_timer_expired(). 806 */ 807 struct timespec64 ts; 808 ktime_get_real_ts64(&ts); 809 h1->ts_last_pkt.ts_sec = ts.tv_sec; 810 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 811 } 812 813 smp_wmb(); 814 815 /* Flush the block */ 816 prb_flush_block(pkc1, pbd1, status); 817 818 sk->sk_data_ready(sk); 819 820 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 821 } 822 823 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 824 { 825 pkc->reset_pending_on_curr_blk = 0; 826 } 827 828 /* 829 * prb_open_block is called by tpacket_rcv or timer callback. 830 * 831 * Reasons why NOT update hrtimer in prb_open_block: 832 * 1) It will increase complexity to distinguish the two caller scenario. 833 * 2) hrtimer_cancel and hrtimer_start need to be called if you want to update 834 * TMO of an already enqueued hrtimer, leading to complex shutdown logic. 835 * 836 * One side effect of NOT update hrtimer when called by tpacket_rcv is that 837 * a newly opened block triggered by tpacket_rcv may be retired earlier than 838 * expected. On the other hand, if timeout is updated in prb_open_block, the 839 * frequent reception of network packets that leads to prb_open_block being 840 * called may cause hrtimer to be removed and enqueued repeatedly. 841 */ 842 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 843 struct tpacket_block_desc *pbd1) 844 { 845 struct timespec64 ts; 846 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 847 848 smp_rmb(); 849 850 /* We could have just memset this but we will lose the 851 * flexibility of making the priv area sticky 852 */ 853 854 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 855 BLOCK_NUM_PKTS(pbd1) = 0; 856 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 857 858 ktime_get_real_ts64(&ts); 859 860 h1->ts_first_pkt.ts_sec = ts.tv_sec; 861 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 862 863 pkc1->pkblk_start = (char *)pbd1; 864 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 865 866 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 867 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 868 869 pbd1->version = pkc1->version; 870 pkc1->prev = pkc1->nxt_offset; 871 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 872 873 prb_thaw_queue(pkc1); 874 875 smp_wmb(); 876 } 877 878 /* 879 * Queue freeze logic: 880 * 1) Assume tp_block_nr = 8 blocks. 881 * 2) At time 't0', user opens Rx ring. 882 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 883 * 4) user-space is either sleeping or processing block '0'. 884 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 885 * it will close block-7,loop around and try to fill block '0'. 886 * call-flow: 887 * __packet_lookup_frame_in_block 888 * prb_retire_current_block() 889 * prb_dispatch_next_block() 890 * |->(BLOCK_STATUS == USER) evaluates to true 891 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 892 * 6) Now there are two cases: 893 * 6.1) Link goes idle right after the queue is frozen. 894 * But remember, the last open_block() refreshed the timer. 895 * When this timer expires,it will refresh itself so that we can 896 * re-open block-0 in near future. 897 * 6.2) Link is busy and keeps on receiving packets. This is a simple 898 * case and __packet_lookup_frame_in_block will check if block-0 899 * is free and can now be re-used. 900 */ 901 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 902 struct packet_sock *po) 903 { 904 pkc->reset_pending_on_curr_blk = 1; 905 po->stats.stats3.tp_freeze_q_cnt++; 906 } 907 908 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 909 910 /* 911 * If the next block is free then we will dispatch it 912 * and return a good offset. 913 * Else, we will freeze the queue. 914 * So, caller must check the return value. 915 */ 916 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 917 struct packet_sock *po) 918 { 919 struct tpacket_block_desc *pbd; 920 921 smp_rmb(); 922 923 /* 1. Get current block num */ 924 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 925 926 /* 2. If this block is currently in_use then freeze the queue */ 927 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 928 prb_freeze_queue(pkc, po); 929 return NULL; 930 } 931 932 /* 933 * 3. 934 * open this block and return the offset where the first packet 935 * needs to get stored. 936 */ 937 prb_open_block(pkc, pbd); 938 return (void *)pkc->nxt_offset; 939 } 940 941 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 942 struct packet_sock *po, unsigned int status) 943 { 944 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 945 946 /* retire/close the current block */ 947 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 948 /* 949 * Plug the case where copy_bits() is in progress on 950 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 951 * have space to copy the pkt in the current block and 952 * called prb_retire_current_block() 953 * 954 * We don't need to worry about the TMO case because 955 * the timer-handler already handled this case. 956 */ 957 if (!(status & TP_STATUS_BLK_TMO)) { 958 /* Waiting for skb_copy_bits to finish... */ 959 write_lock(&pkc->blk_fill_in_prog_lock); 960 write_unlock(&pkc->blk_fill_in_prog_lock); 961 } 962 prb_close_block(pkc, pbd, po, status); 963 return; 964 } 965 } 966 967 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) 968 { 969 return TP_STATUS_USER & BLOCK_STATUS(pbd); 970 } 971 972 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 973 { 974 return pkc->reset_pending_on_curr_blk; 975 } 976 977 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 978 __releases(&pkc->blk_fill_in_prog_lock) 979 { 980 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 981 982 read_unlock(&pkc->blk_fill_in_prog_lock); 983 } 984 985 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 986 struct tpacket3_hdr *ppd) 987 { 988 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 989 } 990 991 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 992 struct tpacket3_hdr *ppd) 993 { 994 ppd->hv1.tp_rxhash = 0; 995 } 996 997 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 998 struct tpacket3_hdr *ppd) 999 { 1000 struct packet_sock *po = container_of(pkc, struct packet_sock, rx_ring.prb_bdqc); 1001 1002 if (skb_vlan_tag_present(pkc->skb)) { 1003 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1004 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1005 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1006 } else if (unlikely(po->sk.sk_type == SOCK_DGRAM && eth_type_vlan(pkc->skb->protocol))) { 1007 ppd->hv1.tp_vlan_tci = vlan_get_tci(pkc->skb, pkc->skb->dev); 1008 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->protocol); 1009 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1010 } else { 1011 ppd->hv1.tp_vlan_tci = 0; 1012 ppd->hv1.tp_vlan_tpid = 0; 1013 ppd->tp_status = TP_STATUS_AVAILABLE; 1014 } 1015 } 1016 1017 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1018 struct tpacket3_hdr *ppd) 1019 { 1020 ppd->hv1.tp_padding = 0; 1021 prb_fill_vlan_info(pkc, ppd); 1022 1023 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1024 prb_fill_rxhash(pkc, ppd); 1025 else 1026 prb_clear_rxhash(pkc, ppd); 1027 } 1028 1029 static void prb_fill_curr_block(char *curr, 1030 struct tpacket_kbdq_core *pkc, 1031 struct tpacket_block_desc *pbd, 1032 unsigned int len) 1033 __acquires(&pkc->blk_fill_in_prog_lock) 1034 { 1035 struct tpacket3_hdr *ppd; 1036 1037 ppd = (struct tpacket3_hdr *)curr; 1038 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1039 pkc->prev = curr; 1040 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1041 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1042 BLOCK_NUM_PKTS(pbd) += 1; 1043 read_lock(&pkc->blk_fill_in_prog_lock); 1044 prb_run_all_ft_ops(pkc, ppd); 1045 } 1046 1047 /* Assumes caller has the sk->rx_queue.lock */ 1048 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1049 struct sk_buff *skb, 1050 unsigned int len 1051 ) 1052 { 1053 struct tpacket_kbdq_core *pkc; 1054 struct tpacket_block_desc *pbd; 1055 char *curr, *end; 1056 1057 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1058 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1059 1060 /* Queue is frozen when user space is lagging behind */ 1061 if (prb_queue_frozen(pkc)) { 1062 /* 1063 * Check if that last block which caused the queue to freeze, 1064 * is still in_use by user-space. 1065 */ 1066 if (prb_curr_blk_in_use(pbd)) { 1067 /* Can't record this packet */ 1068 return NULL; 1069 } else { 1070 /* 1071 * Ok, the block was released by user-space. 1072 * Now let's open that block. 1073 * opening a block also thaws the queue. 1074 * Thawing is a side effect. 1075 */ 1076 prb_open_block(pkc, pbd); 1077 } 1078 } 1079 1080 smp_mb(); 1081 curr = pkc->nxt_offset; 1082 pkc->skb = skb; 1083 end = (char *)pbd + pkc->kblk_size; 1084 1085 /* first try the current block */ 1086 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1087 prb_fill_curr_block(curr, pkc, pbd, len); 1088 return (void *)curr; 1089 } 1090 1091 /* Ok, close the current block */ 1092 prb_retire_current_block(pkc, po, 0); 1093 1094 /* Now, try to dispatch the next block */ 1095 curr = (char *)prb_dispatch_next_block(pkc, po); 1096 if (curr) { 1097 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1098 prb_fill_curr_block(curr, pkc, pbd, len); 1099 return (void *)curr; 1100 } 1101 1102 /* 1103 * No free blocks are available.user_space hasn't caught up yet. 1104 * Queue was just frozen and now this packet will get dropped. 1105 */ 1106 return NULL; 1107 } 1108 1109 static void *packet_current_rx_frame(struct packet_sock *po, 1110 struct sk_buff *skb, 1111 int status, unsigned int len) 1112 { 1113 char *curr = NULL; 1114 switch (po->tp_version) { 1115 case TPACKET_V1: 1116 case TPACKET_V2: 1117 curr = packet_lookup_frame(po, &po->rx_ring, 1118 po->rx_ring.head, status); 1119 return curr; 1120 case TPACKET_V3: 1121 return __packet_lookup_frame_in_block(po, skb, len); 1122 default: 1123 WARN(1, "TPACKET version not supported\n"); 1124 BUG(); 1125 return NULL; 1126 } 1127 } 1128 1129 static void *prb_lookup_block(const struct packet_sock *po, 1130 const struct packet_ring_buffer *rb, 1131 unsigned int idx, 1132 int status) 1133 { 1134 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1135 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1136 1137 if (status != BLOCK_STATUS(pbd)) 1138 return NULL; 1139 return pbd; 1140 } 1141 1142 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1143 { 1144 unsigned int prev; 1145 if (rb->prb_bdqc.kactive_blk_num) 1146 prev = rb->prb_bdqc.kactive_blk_num-1; 1147 else 1148 prev = rb->prb_bdqc.knum_blocks-1; 1149 return prev; 1150 } 1151 1152 /* Assumes caller has held the rx_queue.lock */ 1153 static void *__prb_previous_block(struct packet_sock *po, 1154 struct packet_ring_buffer *rb, 1155 int status) 1156 { 1157 unsigned int previous = prb_previous_blk_num(rb); 1158 return prb_lookup_block(po, rb, previous, status); 1159 } 1160 1161 static void *packet_previous_rx_frame(struct packet_sock *po, 1162 struct packet_ring_buffer *rb, 1163 int status) 1164 { 1165 if (po->tp_version <= TPACKET_V2) 1166 return packet_previous_frame(po, rb, status); 1167 1168 return __prb_previous_block(po, rb, status); 1169 } 1170 1171 static void packet_increment_rx_head(struct packet_sock *po, 1172 struct packet_ring_buffer *rb) 1173 { 1174 switch (po->tp_version) { 1175 case TPACKET_V1: 1176 case TPACKET_V2: 1177 return packet_increment_head(rb); 1178 case TPACKET_V3: 1179 default: 1180 WARN(1, "TPACKET version not supported.\n"); 1181 BUG(); 1182 return; 1183 } 1184 } 1185 1186 static void *packet_previous_frame(struct packet_sock *po, 1187 struct packet_ring_buffer *rb, 1188 int status) 1189 { 1190 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1191 return packet_lookup_frame(po, rb, previous, status); 1192 } 1193 1194 static void packet_increment_head(struct packet_ring_buffer *buff) 1195 { 1196 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1197 } 1198 1199 static void packet_inc_pending(struct packet_ring_buffer *rb) 1200 { 1201 this_cpu_inc(*rb->pending_refcnt); 1202 } 1203 1204 static void packet_dec_pending(struct packet_ring_buffer *rb) 1205 { 1206 this_cpu_dec(*rb->pending_refcnt); 1207 } 1208 1209 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1210 { 1211 unsigned int refcnt = 0; 1212 int cpu; 1213 1214 /* We don't use pending refcount in rx_ring. */ 1215 if (rb->pending_refcnt == NULL) 1216 return 0; 1217 1218 for_each_possible_cpu(cpu) 1219 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1220 1221 return refcnt; 1222 } 1223 1224 static int packet_alloc_pending(struct packet_sock *po) 1225 { 1226 po->rx_ring.pending_refcnt = NULL; 1227 1228 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1229 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1230 return -ENOBUFS; 1231 1232 return 0; 1233 } 1234 1235 static void packet_free_pending(struct packet_sock *po) 1236 { 1237 free_percpu(po->tx_ring.pending_refcnt); 1238 } 1239 1240 #define ROOM_POW_OFF 2 1241 #define ROOM_NONE 0x0 1242 #define ROOM_LOW 0x1 1243 #define ROOM_NORMAL 0x2 1244 1245 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) 1246 { 1247 int idx, len; 1248 1249 len = READ_ONCE(po->rx_ring.frame_max) + 1; 1250 idx = READ_ONCE(po->rx_ring.head); 1251 if (pow_off) 1252 idx += len >> pow_off; 1253 if (idx >= len) 1254 idx -= len; 1255 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1256 } 1257 1258 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) 1259 { 1260 int idx, len; 1261 1262 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); 1263 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); 1264 if (pow_off) 1265 idx += len >> pow_off; 1266 if (idx >= len) 1267 idx -= len; 1268 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1269 } 1270 1271 static int __packet_rcv_has_room(const struct packet_sock *po, 1272 const struct sk_buff *skb) 1273 { 1274 const struct sock *sk = &po->sk; 1275 int ret = ROOM_NONE; 1276 1277 if (po->prot_hook.func != tpacket_rcv) { 1278 int rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1279 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1280 - (skb ? skb->truesize : 0); 1281 1282 if (avail > (rcvbuf >> ROOM_POW_OFF)) 1283 return ROOM_NORMAL; 1284 else if (avail > 0) 1285 return ROOM_LOW; 1286 else 1287 return ROOM_NONE; 1288 } 1289 1290 if (po->tp_version == TPACKET_V3) { 1291 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1292 ret = ROOM_NORMAL; 1293 else if (__tpacket_v3_has_room(po, 0)) 1294 ret = ROOM_LOW; 1295 } else { 1296 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1297 ret = ROOM_NORMAL; 1298 else if (__tpacket_has_room(po, 0)) 1299 ret = ROOM_LOW; 1300 } 1301 1302 return ret; 1303 } 1304 1305 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1306 { 1307 bool pressure; 1308 int ret; 1309 1310 ret = __packet_rcv_has_room(po, skb); 1311 pressure = ret != ROOM_NORMAL; 1312 1313 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure) 1314 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure); 1315 1316 return ret; 1317 } 1318 1319 static void __packet_rcv_try_clear_pressure(struct packet_sock *po) 1320 { 1321 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) && 1322 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 1323 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false); 1324 } 1325 1326 static void packet_rcv_try_clear_pressure(struct packet_sock *po) 1327 { 1328 struct sock *sk = &po->sk; 1329 1330 if (!packet_sock_flag(po, PACKET_SOCK_PRESSURE)) 1331 return; 1332 1333 spin_lock_bh(&sk->sk_receive_queue.lock); 1334 __packet_rcv_try_clear_pressure(po); 1335 spin_unlock_bh(&sk->sk_receive_queue.lock); 1336 } 1337 1338 static void packet_sock_destruct(struct sock *sk) 1339 { 1340 skb_queue_purge(&sk->sk_error_queue); 1341 1342 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1343 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1344 1345 packet_free_pending(pkt_sk(sk)); 1346 1347 if (!sock_flag(sk, SOCK_DEAD)) { 1348 pr_err("Attempt to release alive packet socket: %p\n", sk); 1349 return; 1350 } 1351 } 1352 1353 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1354 { 1355 u32 *history = po->rollover->history; 1356 u32 victim, rxhash; 1357 int i, count = 0; 1358 1359 rxhash = skb_get_hash(skb); 1360 for (i = 0; i < ROLLOVER_HLEN; i++) 1361 if (READ_ONCE(history[i]) == rxhash) 1362 count++; 1363 1364 victim = get_random_u32_below(ROLLOVER_HLEN); 1365 1366 /* Avoid dirtying the cache line if possible */ 1367 if (READ_ONCE(history[victim]) != rxhash) 1368 WRITE_ONCE(history[victim], rxhash); 1369 1370 return count > (ROLLOVER_HLEN >> 1); 1371 } 1372 1373 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1374 struct sk_buff *skb, 1375 unsigned int num) 1376 { 1377 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1378 } 1379 1380 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1381 struct sk_buff *skb, 1382 unsigned int num) 1383 { 1384 unsigned int val = atomic_inc_return(&f->rr_cur); 1385 1386 return val % num; 1387 } 1388 1389 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1390 struct sk_buff *skb, 1391 unsigned int num) 1392 { 1393 return smp_processor_id() % num; 1394 } 1395 1396 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1397 struct sk_buff *skb, 1398 unsigned int num) 1399 { 1400 return get_random_u32_below(num); 1401 } 1402 1403 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1404 struct sk_buff *skb, 1405 unsigned int idx, bool try_self, 1406 unsigned int num) 1407 { 1408 struct packet_sock *po, *po_next, *po_skip = NULL; 1409 unsigned int i, j, room = ROOM_NONE; 1410 1411 po = pkt_sk(rcu_dereference(f->arr[idx])); 1412 1413 if (try_self) { 1414 room = packet_rcv_has_room(po, skb); 1415 if (room == ROOM_NORMAL || 1416 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1417 return idx; 1418 po_skip = po; 1419 } 1420 1421 i = j = min_t(int, po->rollover->sock, num - 1); 1422 do { 1423 po_next = pkt_sk(rcu_dereference(f->arr[i])); 1424 if (po_next != po_skip && 1425 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) && 1426 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1427 if (i != j) 1428 po->rollover->sock = i; 1429 atomic_long_inc(&po->rollover->num); 1430 if (room == ROOM_LOW) 1431 atomic_long_inc(&po->rollover->num_huge); 1432 return i; 1433 } 1434 1435 if (++i == num) 1436 i = 0; 1437 } while (i != j); 1438 1439 atomic_long_inc(&po->rollover->num_failed); 1440 return idx; 1441 } 1442 1443 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1444 struct sk_buff *skb, 1445 unsigned int num) 1446 { 1447 return skb_get_queue_mapping(skb) % num; 1448 } 1449 1450 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1451 struct sk_buff *skb, 1452 unsigned int num) 1453 { 1454 struct bpf_prog *prog; 1455 unsigned int ret = 0; 1456 1457 rcu_read_lock(); 1458 prog = rcu_dereference(f->bpf_prog); 1459 if (prog) 1460 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1461 rcu_read_unlock(); 1462 1463 return ret; 1464 } 1465 1466 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1467 { 1468 return f->flags & (flag >> 8); 1469 } 1470 1471 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1472 struct packet_type *pt, struct net_device *orig_dev) 1473 { 1474 struct packet_fanout *f = pt->af_packet_priv; 1475 unsigned int num = READ_ONCE(f->num_members); 1476 struct net *net = read_pnet(&f->net); 1477 struct packet_sock *po; 1478 unsigned int idx; 1479 1480 if (!net_eq(dev_net(dev), net) || !num) { 1481 kfree_skb(skb); 1482 return 0; 1483 } 1484 1485 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1486 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1487 if (!skb) 1488 return 0; 1489 } 1490 switch (f->type) { 1491 case PACKET_FANOUT_HASH: 1492 default: 1493 idx = fanout_demux_hash(f, skb, num); 1494 break; 1495 case PACKET_FANOUT_LB: 1496 idx = fanout_demux_lb(f, skb, num); 1497 break; 1498 case PACKET_FANOUT_CPU: 1499 idx = fanout_demux_cpu(f, skb, num); 1500 break; 1501 case PACKET_FANOUT_RND: 1502 idx = fanout_demux_rnd(f, skb, num); 1503 break; 1504 case PACKET_FANOUT_QM: 1505 idx = fanout_demux_qm(f, skb, num); 1506 break; 1507 case PACKET_FANOUT_ROLLOVER: 1508 idx = fanout_demux_rollover(f, skb, 0, false, num); 1509 break; 1510 case PACKET_FANOUT_CBPF: 1511 case PACKET_FANOUT_EBPF: 1512 idx = fanout_demux_bpf(f, skb, num); 1513 break; 1514 } 1515 1516 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1517 idx = fanout_demux_rollover(f, skb, idx, true, num); 1518 1519 po = pkt_sk(rcu_dereference(f->arr[idx])); 1520 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1521 } 1522 1523 DEFINE_MUTEX(fanout_mutex); 1524 EXPORT_SYMBOL_GPL(fanout_mutex); 1525 static LIST_HEAD(fanout_list); 1526 static u16 fanout_next_id; 1527 1528 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1529 { 1530 struct packet_fanout *f = po->fanout; 1531 1532 spin_lock(&f->lock); 1533 rcu_assign_pointer(f->arr[f->num_members], sk); 1534 smp_wmb(); 1535 f->num_members++; 1536 if (f->num_members == 1) 1537 dev_add_pack(&f->prot_hook); 1538 spin_unlock(&f->lock); 1539 } 1540 1541 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1542 { 1543 struct packet_fanout *f = po->fanout; 1544 int i; 1545 1546 spin_lock(&f->lock); 1547 for (i = 0; i < f->num_members; i++) { 1548 if (rcu_dereference_protected(f->arr[i], 1549 lockdep_is_held(&f->lock)) == sk) 1550 break; 1551 } 1552 BUG_ON(i >= f->num_members); 1553 rcu_assign_pointer(f->arr[i], 1554 rcu_dereference_protected(f->arr[f->num_members - 1], 1555 lockdep_is_held(&f->lock))); 1556 f->num_members--; 1557 if (f->num_members == 0) 1558 __dev_remove_pack(&f->prot_hook); 1559 spin_unlock(&f->lock); 1560 } 1561 1562 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1563 { 1564 if (sk->sk_family != PF_PACKET) 1565 return false; 1566 1567 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1568 } 1569 1570 static void fanout_init_data(struct packet_fanout *f) 1571 { 1572 switch (f->type) { 1573 case PACKET_FANOUT_LB: 1574 atomic_set(&f->rr_cur, 0); 1575 break; 1576 case PACKET_FANOUT_CBPF: 1577 case PACKET_FANOUT_EBPF: 1578 RCU_INIT_POINTER(f->bpf_prog, NULL); 1579 break; 1580 } 1581 } 1582 1583 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1584 { 1585 struct bpf_prog *old; 1586 1587 spin_lock(&f->lock); 1588 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1589 rcu_assign_pointer(f->bpf_prog, new); 1590 spin_unlock(&f->lock); 1591 1592 if (old) { 1593 synchronize_net(); 1594 bpf_prog_destroy(old); 1595 } 1596 } 1597 1598 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, 1599 unsigned int len) 1600 { 1601 struct bpf_prog *new; 1602 struct sock_fprog fprog; 1603 int ret; 1604 1605 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1606 return -EPERM; 1607 1608 ret = copy_bpf_fprog_from_user(&fprog, data, len); 1609 if (ret) 1610 return ret; 1611 1612 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1613 if (ret) 1614 return ret; 1615 1616 __fanout_set_data_bpf(po->fanout, new); 1617 return 0; 1618 } 1619 1620 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, 1621 unsigned int len) 1622 { 1623 struct bpf_prog *new; 1624 u32 fd; 1625 1626 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1627 return -EPERM; 1628 if (len != sizeof(fd)) 1629 return -EINVAL; 1630 if (copy_from_sockptr(&fd, data, len)) 1631 return -EFAULT; 1632 1633 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1634 if (IS_ERR(new)) 1635 return PTR_ERR(new); 1636 1637 __fanout_set_data_bpf(po->fanout, new); 1638 return 0; 1639 } 1640 1641 static int fanout_set_data(struct packet_sock *po, sockptr_t data, 1642 unsigned int len) 1643 { 1644 switch (po->fanout->type) { 1645 case PACKET_FANOUT_CBPF: 1646 return fanout_set_data_cbpf(po, data, len); 1647 case PACKET_FANOUT_EBPF: 1648 return fanout_set_data_ebpf(po, data, len); 1649 default: 1650 return -EINVAL; 1651 } 1652 } 1653 1654 static void fanout_release_data(struct packet_fanout *f) 1655 { 1656 switch (f->type) { 1657 case PACKET_FANOUT_CBPF: 1658 case PACKET_FANOUT_EBPF: 1659 __fanout_set_data_bpf(f, NULL); 1660 } 1661 } 1662 1663 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1664 { 1665 struct packet_fanout *f; 1666 1667 list_for_each_entry(f, &fanout_list, list) { 1668 if (f->id == candidate_id && 1669 read_pnet(&f->net) == sock_net(sk)) { 1670 return false; 1671 } 1672 } 1673 return true; 1674 } 1675 1676 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1677 { 1678 u16 id = fanout_next_id; 1679 1680 do { 1681 if (__fanout_id_is_free(sk, id)) { 1682 *new_id = id; 1683 fanout_next_id = id + 1; 1684 return true; 1685 } 1686 1687 id++; 1688 } while (id != fanout_next_id); 1689 1690 return false; 1691 } 1692 1693 static int fanout_add(struct sock *sk, struct fanout_args *args) 1694 { 1695 struct packet_rollover *rollover = NULL; 1696 struct packet_sock *po = pkt_sk(sk); 1697 u16 type_flags = args->type_flags; 1698 struct packet_fanout *f, *match; 1699 u8 type = type_flags & 0xff; 1700 u8 flags = type_flags >> 8; 1701 u16 id = args->id; 1702 int err; 1703 1704 switch (type) { 1705 case PACKET_FANOUT_ROLLOVER: 1706 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1707 return -EINVAL; 1708 break; 1709 case PACKET_FANOUT_HASH: 1710 case PACKET_FANOUT_LB: 1711 case PACKET_FANOUT_CPU: 1712 case PACKET_FANOUT_RND: 1713 case PACKET_FANOUT_QM: 1714 case PACKET_FANOUT_CBPF: 1715 case PACKET_FANOUT_EBPF: 1716 break; 1717 default: 1718 return -EINVAL; 1719 } 1720 1721 mutex_lock(&fanout_mutex); 1722 1723 err = -EALREADY; 1724 if (po->fanout) 1725 goto out; 1726 1727 if (type == PACKET_FANOUT_ROLLOVER || 1728 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1729 err = -ENOMEM; 1730 rollover = kzalloc_obj(*rollover); 1731 if (!rollover) 1732 goto out; 1733 atomic_long_set(&rollover->num, 0); 1734 atomic_long_set(&rollover->num_huge, 0); 1735 atomic_long_set(&rollover->num_failed, 0); 1736 } 1737 1738 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1739 if (id != 0) { 1740 err = -EINVAL; 1741 goto out; 1742 } 1743 if (!fanout_find_new_id(sk, &id)) { 1744 err = -ENOMEM; 1745 goto out; 1746 } 1747 /* ephemeral flag for the first socket in the group: drop it */ 1748 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1749 } 1750 1751 match = NULL; 1752 list_for_each_entry(f, &fanout_list, list) { 1753 if (f->id == id && 1754 read_pnet(&f->net) == sock_net(sk)) { 1755 match = f; 1756 break; 1757 } 1758 } 1759 err = -EINVAL; 1760 if (match) { 1761 if (match->flags != flags) 1762 goto out; 1763 if (args->max_num_members && 1764 args->max_num_members != match->max_num_members) 1765 goto out; 1766 } else { 1767 if (args->max_num_members > PACKET_FANOUT_MAX) 1768 goto out; 1769 if (!args->max_num_members) 1770 /* legacy PACKET_FANOUT_MAX */ 1771 args->max_num_members = 256; 1772 err = -ENOMEM; 1773 match = kvzalloc_flex(*match, arr, args->max_num_members); 1774 if (!match) 1775 goto out; 1776 write_pnet(&match->net, sock_net(sk)); 1777 match->id = id; 1778 match->type = type; 1779 match->flags = flags; 1780 INIT_LIST_HEAD(&match->list); 1781 spin_lock_init(&match->lock); 1782 refcount_set(&match->sk_ref, 0); 1783 fanout_init_data(match); 1784 match->prot_hook.type = po->prot_hook.type; 1785 match->prot_hook.dev = po->prot_hook.dev; 1786 match->prot_hook.func = packet_rcv_fanout; 1787 match->prot_hook.af_packet_priv = match; 1788 match->prot_hook.af_packet_net = read_pnet(&match->net); 1789 match->prot_hook.id_match = match_fanout_group; 1790 match->max_num_members = args->max_num_members; 1791 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; 1792 list_add(&match->list, &fanout_list); 1793 } 1794 err = -EINVAL; 1795 1796 spin_lock(&po->bind_lock); 1797 if (po->num && 1798 match->type == type && 1799 match->prot_hook.type == po->prot_hook.type && 1800 match->prot_hook.dev == po->prot_hook.dev) { 1801 err = -ENOSPC; 1802 if (refcount_read(&match->sk_ref) < match->max_num_members) { 1803 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1804 WRITE_ONCE(po->fanout, match); 1805 1806 po->rollover = rollover; 1807 rollover = NULL; 1808 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1809 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 1810 __dev_remove_pack(&po->prot_hook); 1811 __fanout_link(sk, po); 1812 } 1813 err = 0; 1814 } 1815 } 1816 spin_unlock(&po->bind_lock); 1817 1818 if (err && !refcount_read(&match->sk_ref)) { 1819 list_del(&match->list); 1820 kvfree(match); 1821 } 1822 1823 out: 1824 kfree(rollover); 1825 mutex_unlock(&fanout_mutex); 1826 return err; 1827 } 1828 1829 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1830 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1831 * It is the responsibility of the caller to call fanout_release_data() and 1832 * free the returned packet_fanout (after synchronize_net()) 1833 */ 1834 static struct packet_fanout *fanout_release(struct sock *sk) 1835 { 1836 struct packet_sock *po = pkt_sk(sk); 1837 struct packet_fanout *f; 1838 1839 mutex_lock(&fanout_mutex); 1840 f = po->fanout; 1841 if (f) { 1842 po->fanout = NULL; 1843 1844 if (refcount_dec_and_test(&f->sk_ref)) 1845 list_del(&f->list); 1846 else 1847 f = NULL; 1848 } 1849 mutex_unlock(&fanout_mutex); 1850 1851 return f; 1852 } 1853 1854 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1855 struct sk_buff *skb) 1856 { 1857 /* Earlier code assumed this would be a VLAN pkt, double-check 1858 * this now that we have the actual packet in hand. We can only 1859 * do this check on Ethernet devices. 1860 */ 1861 if (unlikely(dev->type != ARPHRD_ETHER)) 1862 return false; 1863 1864 skb_reset_mac_header(skb); 1865 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1866 } 1867 1868 static const struct proto_ops packet_ops; 1869 1870 static const struct proto_ops packet_ops_spkt; 1871 1872 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1873 struct packet_type *pt, struct net_device *orig_dev) 1874 { 1875 struct sock *sk; 1876 struct sockaddr_pkt *spkt; 1877 1878 /* 1879 * When we registered the protocol we saved the socket in the data 1880 * field for just this event. 1881 */ 1882 1883 sk = pt->af_packet_priv; 1884 1885 /* 1886 * Yank back the headers [hope the device set this 1887 * right or kerboom...] 1888 * 1889 * Incoming packets have ll header pulled, 1890 * push it back. 1891 * 1892 * For outgoing ones skb->data == skb_mac_header(skb) 1893 * so that this procedure is noop. 1894 */ 1895 1896 if (skb->pkt_type == PACKET_LOOPBACK) 1897 goto out; 1898 1899 if (!net_eq(dev_net(dev), sock_net(sk))) 1900 goto out; 1901 1902 skb = skb_share_check(skb, GFP_ATOMIC); 1903 if (skb == NULL) 1904 goto oom; 1905 1906 /* drop any routing info */ 1907 skb_dst_drop(skb); 1908 1909 /* drop conntrack reference */ 1910 nf_reset_ct(skb); 1911 1912 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1913 1914 if (dev_has_header(dev)) 1915 skb_push(skb, skb->data - skb_mac_header(skb)); 1916 1917 /* 1918 * The SOCK_PACKET socket receives _all_ frames. 1919 */ 1920 1921 spkt->spkt_family = dev->type; 1922 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1923 spkt->spkt_protocol = skb->protocol; 1924 1925 /* 1926 * Charge the memory to the socket. This is done specifically 1927 * to prevent sockets using all the memory up. 1928 */ 1929 1930 if (sock_queue_rcv_skb(sk, skb) == 0) 1931 return 0; 1932 1933 out: 1934 kfree_skb(skb); 1935 oom: 1936 return 0; 1937 } 1938 1939 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1940 { 1941 int depth; 1942 1943 /* On TX skb->data is the L2 header; anchor it for all socket types. */ 1944 skb_reset_mac_header(skb); 1945 1946 if (!skb->protocol && sock->type == SOCK_RAW) 1947 skb->protocol = dev_parse_header_protocol(skb); 1948 1949 skb_probe_transport_header(skb); 1950 1951 /* Move network header to the right position for VLAN tagged packets */ 1952 if (likely(skb->dev->type == ARPHRD_ETHER) && 1953 eth_type_vlan(skb->protocol) && 1954 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 1955 skb_set_network_header(skb, depth); 1956 } 1957 1958 /* 1959 * Output a raw packet to a device layer. This bypasses all the other 1960 * protocol layers and you must therefore supply it with a complete frame 1961 */ 1962 1963 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1964 size_t len) 1965 { 1966 struct sock *sk = sock->sk; 1967 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1968 struct sk_buff *skb = NULL; 1969 struct net_device *dev; 1970 struct sockcm_cookie sockc; 1971 __be16 proto = 0; 1972 int hard_header_len; 1973 int extra_len = 0; 1974 int err; 1975 1976 /* 1977 * Get and verify the address. 1978 */ 1979 1980 if (saddr) { 1981 if (msg->msg_namelen < sizeof(struct sockaddr)) 1982 return -EINVAL; 1983 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1984 proto = saddr->spkt_protocol; 1985 } else 1986 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1987 1988 /* 1989 * Find the device first to size check it 1990 */ 1991 1992 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1993 retry: 1994 rcu_read_lock(); 1995 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1996 err = -ENODEV; 1997 if (dev == NULL) 1998 goto out_unlock; 1999 2000 err = -ENETDOWN; 2001 if (!(dev->flags & IFF_UP)) 2002 goto out_unlock; 2003 2004 /* 2005 * You may not queue a frame bigger than the mtu. This is the lowest level 2006 * raw protocol and you must do your own fragmentation at this level. 2007 */ 2008 2009 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2010 if (!netif_supports_nofcs(dev)) { 2011 err = -EPROTONOSUPPORT; 2012 goto out_unlock; 2013 } 2014 extra_len = 4; /* We're doing our own CRC */ 2015 } 2016 2017 /* Keep the allocation-time header length across retry. */ 2018 if (!skb) 2019 hard_header_len = READ_ONCE(dev->hard_header_len); 2020 2021 err = -EMSGSIZE; 2022 if (len > dev->mtu + hard_header_len + VLAN_HLEN + extra_len) 2023 goto out_unlock; 2024 2025 if (!skb) { 2026 size_t reserved = LL_RESERVED_SPACE_EX(dev, hard_header_len); 2027 int tlen = dev->needed_tailroom; 2028 unsigned int hhlen = dev->header_ops ? hard_header_len : 0; 2029 2030 rcu_read_unlock(); 2031 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2032 if (skb == NULL) 2033 return -ENOBUFS; 2034 /* FIXME: Save some space for broken drivers that write a hard 2035 * header at transmission time by themselves. PPP is the notable 2036 * one here. This should really be fixed at the driver level. 2037 */ 2038 skb_reserve(skb, reserved); 2039 skb_reset_network_header(skb); 2040 2041 /* Try to align data part correctly */ 2042 if (hhlen) { 2043 skb->data -= hhlen; 2044 skb->tail -= hhlen; 2045 if (len < hhlen) 2046 skb_reset_network_header(skb); 2047 } 2048 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2049 if (err) 2050 goto out_free; 2051 goto retry; 2052 } 2053 2054 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2055 err = -EINVAL; 2056 goto out_unlock; 2057 } 2058 if (len > (dev->mtu + hard_header_len + extra_len) && 2059 !packet_extra_vlan_len_allowed(dev, skb)) { 2060 err = -EMSGSIZE; 2061 goto out_unlock; 2062 } 2063 2064 sockcm_init(&sockc, sk); 2065 if (msg->msg_controllen) { 2066 err = sock_cmsg_send(sk, msg, &sockc); 2067 if (unlikely(err)) 2068 goto out_unlock; 2069 } 2070 2071 skb->protocol = proto; 2072 skb->dev = dev; 2073 skb->priority = sockc.priority; 2074 skb->mark = sockc.mark; 2075 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2076 skb_setup_tx_timestamp(skb, &sockc); 2077 2078 if (unlikely(extra_len == 4)) 2079 skb->no_fcs = 1; 2080 2081 packet_parse_headers(skb, sock); 2082 2083 dev_queue_xmit(skb); 2084 rcu_read_unlock(); 2085 return len; 2086 2087 out_unlock: 2088 rcu_read_unlock(); 2089 out_free: 2090 kfree_skb(skb); 2091 return err; 2092 } 2093 2094 static unsigned int run_filter(struct sk_buff *skb, 2095 const struct sock *sk, 2096 unsigned int res) 2097 { 2098 struct sk_filter *filter; 2099 2100 rcu_read_lock(); 2101 filter = rcu_dereference(sk->sk_filter); 2102 if (filter != NULL) 2103 res = bpf_prog_run_clear_cb(filter->prog, skb); 2104 rcu_read_unlock(); 2105 2106 return res; 2107 } 2108 2109 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2110 size_t *len, int vnet_hdr_sz) 2111 { 2112 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2113 2114 if (*len < vnet_hdr_sz) 2115 return -EINVAL; 2116 *len -= vnet_hdr_sz; 2117 2118 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2119 return -EINVAL; 2120 2121 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2122 } 2123 2124 /* 2125 * This function makes lazy skb cloning in hope that most of packets 2126 * are discarded by BPF. 2127 * 2128 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2129 * and skb->cb are mangled. It works because (and until) packets 2130 * falling here are owned by current CPU. Output packets are cloned 2131 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2132 * sequentially, so that if we return skb to original state on exit, 2133 * we will not harm anyone. 2134 */ 2135 2136 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2137 struct packet_type *pt, struct net_device *orig_dev) 2138 { 2139 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2140 struct sock *sk = NULL; 2141 struct sockaddr_ll *sll; 2142 struct packet_sock *po; 2143 u8 *skb_head = skb->data; 2144 int skb_len = skb->len; 2145 unsigned int snaplen, res; 2146 2147 if (skb->pkt_type == PACKET_LOOPBACK) 2148 goto drop; 2149 2150 sk = pt->af_packet_priv; 2151 po = pkt_sk(sk); 2152 2153 if (!net_eq(dev_net(dev), sock_net(sk))) 2154 goto drop; 2155 2156 skb->dev = dev; 2157 2158 if (dev_has_header(dev)) { 2159 /* The device has an explicit notion of ll header, 2160 * exported to higher levels. 2161 * 2162 * Otherwise, the device hides details of its frame 2163 * structure, so that corresponding packet head is 2164 * never delivered to user. 2165 */ 2166 if (sk->sk_type != SOCK_DGRAM) 2167 skb_push(skb, skb->data - skb_mac_header(skb)); 2168 else if (skb->pkt_type == PACKET_OUTGOING) { 2169 /* Special case: outgoing packets have ll header at head */ 2170 skb_pull(skb, skb_network_offset(skb)); 2171 } 2172 } 2173 2174 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2175 2176 res = run_filter(skb, sk, snaplen); 2177 if (!res) 2178 goto drop_n_restore; 2179 if (snaplen > res) 2180 snaplen = res; 2181 2182 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2183 goto drop_n_acct; 2184 2185 if (skb_shared(skb)) { 2186 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2187 if (nskb == NULL) 2188 goto drop_n_acct; 2189 2190 if (skb_head != skb->data) { 2191 skb->data = skb_head; 2192 skb->len = skb_len; 2193 } 2194 consume_skb(skb); 2195 skb = nskb; 2196 } 2197 2198 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2199 2200 sll = &PACKET_SKB_CB(skb)->sa.ll; 2201 sll->sll_hatype = dev->type; 2202 sll->sll_pkttype = skb->pkt_type; 2203 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2204 sll->sll_ifindex = orig_dev->ifindex; 2205 else 2206 sll->sll_ifindex = dev->ifindex; 2207 2208 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2209 2210 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2211 * Use their space for storing the original skb length. 2212 */ 2213 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2214 2215 if (pskb_trim(skb, snaplen)) 2216 goto drop_n_acct; 2217 2218 skb_set_owner_r(skb, sk); 2219 skb->dev = NULL; 2220 skb_dst_drop(skb); 2221 2222 /* drop conntrack reference */ 2223 nf_reset_ct(skb); 2224 2225 spin_lock(&sk->sk_receive_queue.lock); 2226 po->stats.stats1.tp_packets++; 2227 sock_skb_set_dropcount(sk, skb); 2228 skb_clear_delivery_time(skb); 2229 __skb_queue_tail(&sk->sk_receive_queue, skb); 2230 spin_unlock(&sk->sk_receive_queue.lock); 2231 sk->sk_data_ready(sk); 2232 return 0; 2233 2234 drop_n_acct: 2235 atomic_inc(&po->tp_drops); 2236 sk_drops_inc(sk); 2237 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2238 2239 drop_n_restore: 2240 if (skb_head != skb->data && skb_shared(skb)) { 2241 skb->data = skb_head; 2242 skb->len = skb_len; 2243 } 2244 drop: 2245 sk_skb_reason_drop(sk, skb, drop_reason); 2246 return 0; 2247 } 2248 2249 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2250 struct packet_type *pt, struct net_device *orig_dev) 2251 { 2252 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2253 struct sock *sk = NULL; 2254 struct packet_sock *po; 2255 struct sockaddr_ll *sll; 2256 union tpacket_uhdr h; 2257 u8 *skb_head = skb->data; 2258 int skb_len = skb->len; 2259 unsigned int snaplen, res; 2260 unsigned long status = TP_STATUS_USER; 2261 unsigned short macoff, hdrlen; 2262 unsigned int netoff; 2263 struct sk_buff *copy_skb = NULL; 2264 struct timespec64 ts; 2265 __u32 ts_status; 2266 unsigned int slot_id = 0; 2267 int vnet_hdr_sz = 0; 2268 2269 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2270 * We may add members to them until current aligned size without forcing 2271 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2272 */ 2273 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2274 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2275 2276 if (skb->pkt_type == PACKET_LOOPBACK) 2277 goto drop; 2278 2279 sk = pt->af_packet_priv; 2280 po = pkt_sk(sk); 2281 2282 if (!net_eq(dev_net(dev), sock_net(sk))) 2283 goto drop; 2284 2285 if (dev_has_header(dev)) { 2286 if (sk->sk_type != SOCK_DGRAM) 2287 skb_push(skb, skb->data - skb_mac_header(skb)); 2288 else if (skb->pkt_type == PACKET_OUTGOING) { 2289 /* Special case: outgoing packets have ll header at head */ 2290 skb_pull(skb, skb_network_offset(skb)); 2291 } 2292 } 2293 2294 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2295 2296 res = run_filter(skb, sk, snaplen); 2297 if (!res) 2298 goto drop_n_restore; 2299 2300 /* If we are flooded, just give up */ 2301 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2302 atomic_inc(&po->tp_drops); 2303 goto drop_n_restore; 2304 } 2305 2306 if (skb->ip_summed == CHECKSUM_PARTIAL) 2307 status |= TP_STATUS_CSUMNOTREADY; 2308 else if (skb->pkt_type != PACKET_OUTGOING && 2309 skb_csum_unnecessary(skb)) 2310 status |= TP_STATUS_CSUM_VALID; 2311 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2312 status |= TP_STATUS_GSO_TCP; 2313 2314 if (snaplen > res) 2315 snaplen = res; 2316 2317 if (sk->sk_type == SOCK_DGRAM) { 2318 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2319 po->tp_reserve; 2320 } else { 2321 unsigned int maclen = skb_network_offset(skb); 2322 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2323 (maclen < 16 ? 16 : maclen)) + 2324 po->tp_reserve; 2325 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2326 if (vnet_hdr_sz) 2327 netoff += vnet_hdr_sz; 2328 macoff = netoff - maclen; 2329 } 2330 if (netoff > USHRT_MAX) { 2331 atomic_inc(&po->tp_drops); 2332 goto drop_n_restore; 2333 } 2334 if (po->tp_version <= TPACKET_V2) { 2335 if (macoff + snaplen > po->rx_ring.frame_size) { 2336 if (READ_ONCE(po->copy_thresh) && 2337 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2338 if (skb_shared(skb)) { 2339 copy_skb = skb_clone(skb, GFP_ATOMIC); 2340 } else { 2341 copy_skb = skb_get(skb); 2342 skb_head = skb->data; 2343 } 2344 if (copy_skb) { 2345 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2346 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2347 skb_set_owner_r(copy_skb, sk); 2348 } 2349 } 2350 snaplen = po->rx_ring.frame_size - macoff; 2351 if ((int)snaplen < 0) { 2352 snaplen = 0; 2353 vnet_hdr_sz = 0; 2354 } 2355 } 2356 } else if (unlikely(macoff + snaplen > 2357 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2358 u32 nval; 2359 2360 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2361 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2362 snaplen, nval, macoff); 2363 snaplen = nval; 2364 if (unlikely((int)snaplen < 0)) { 2365 snaplen = 0; 2366 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2367 vnet_hdr_sz = 0; 2368 } 2369 } 2370 spin_lock(&sk->sk_receive_queue.lock); 2371 h.raw = packet_current_rx_frame(po, skb, 2372 TP_STATUS_KERNEL, (macoff+snaplen)); 2373 if (!h.raw) 2374 goto drop_n_account; 2375 2376 if (po->tp_version <= TPACKET_V2) { 2377 slot_id = po->rx_ring.head; 2378 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2379 goto drop_n_account; 2380 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2381 } 2382 2383 if (vnet_hdr_sz && 2384 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2385 sizeof(struct virtio_net_hdr), 2386 vio_le(), true, 0)) { 2387 if (po->tp_version <= TPACKET_V2) 2388 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2389 else 2390 prb_clear_blk_fill_status(&po->rx_ring); 2391 goto drop_n_account; 2392 } 2393 2394 if (po->tp_version <= TPACKET_V2) { 2395 packet_increment_rx_head(po, &po->rx_ring); 2396 /* 2397 * LOSING will be reported till you read the stats, 2398 * because it's COR - Clear On Read. 2399 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2400 * at packet level. 2401 */ 2402 if (atomic_read(&po->tp_drops)) 2403 status |= TP_STATUS_LOSING; 2404 } 2405 2406 po->stats.stats1.tp_packets++; 2407 if (copy_skb) { 2408 status |= TP_STATUS_COPY; 2409 skb_clear_delivery_time(copy_skb); 2410 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2411 } 2412 spin_unlock(&sk->sk_receive_queue.lock); 2413 2414 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2415 2416 /* Always timestamp; prefer an existing software timestamp taken 2417 * closer to the time of capture. 2418 */ 2419 ts_status = tpacket_get_timestamp(skb, &ts, 2420 READ_ONCE(po->tp_tstamp) | 2421 SOF_TIMESTAMPING_SOFTWARE); 2422 if (!ts_status) 2423 ktime_get_real_ts64(&ts); 2424 2425 status |= ts_status; 2426 2427 switch (po->tp_version) { 2428 case TPACKET_V1: 2429 h.h1->tp_len = skb->len; 2430 h.h1->tp_snaplen = snaplen; 2431 h.h1->tp_mac = macoff; 2432 h.h1->tp_net = netoff; 2433 h.h1->tp_sec = ts.tv_sec; 2434 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2435 hdrlen = sizeof(*h.h1); 2436 break; 2437 case TPACKET_V2: 2438 h.h2->tp_len = skb->len; 2439 h.h2->tp_snaplen = snaplen; 2440 h.h2->tp_mac = macoff; 2441 h.h2->tp_net = netoff; 2442 h.h2->tp_sec = ts.tv_sec; 2443 h.h2->tp_nsec = ts.tv_nsec; 2444 if (skb_vlan_tag_present(skb)) { 2445 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2446 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2447 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2448 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2449 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2450 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2451 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2452 } else { 2453 h.h2->tp_vlan_tci = 0; 2454 h.h2->tp_vlan_tpid = 0; 2455 } 2456 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2457 hdrlen = sizeof(*h.h2); 2458 break; 2459 case TPACKET_V3: 2460 /* tp_nxt_offset,vlan are already populated above. 2461 * So DONT clear those fields here 2462 */ 2463 h.h3->tp_status |= status; 2464 h.h3->tp_len = skb->len; 2465 h.h3->tp_snaplen = snaplen; 2466 h.h3->tp_mac = macoff; 2467 h.h3->tp_net = netoff; 2468 h.h3->tp_sec = ts.tv_sec; 2469 h.h3->tp_nsec = ts.tv_nsec; 2470 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2471 hdrlen = sizeof(*h.h3); 2472 break; 2473 default: 2474 BUG(); 2475 } 2476 2477 sll = h.raw + TPACKET_ALIGN(hdrlen); 2478 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2479 sll->sll_family = AF_PACKET; 2480 sll->sll_hatype = dev->type; 2481 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2482 vlan_get_protocol_dgram(skb) : skb->protocol; 2483 sll->sll_pkttype = skb->pkt_type; 2484 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2485 sll->sll_ifindex = orig_dev->ifindex; 2486 else 2487 sll->sll_ifindex = dev->ifindex; 2488 2489 smp_mb(); 2490 2491 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2492 if (po->tp_version <= TPACKET_V2) { 2493 u8 *start, *end; 2494 2495 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2496 macoff + snaplen); 2497 2498 for (start = h.raw; start < end; start += PAGE_SIZE) 2499 flush_dcache_page(pgv_to_page(start)); 2500 } 2501 smp_wmb(); 2502 #endif 2503 2504 if (po->tp_version <= TPACKET_V2) { 2505 spin_lock(&sk->sk_receive_queue.lock); 2506 __packet_set_status(po, h.raw, status); 2507 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2508 spin_unlock(&sk->sk_receive_queue.lock); 2509 sk->sk_data_ready(sk); 2510 } else if (po->tp_version == TPACKET_V3) { 2511 prb_clear_blk_fill_status(&po->rx_ring); 2512 } 2513 2514 drop_n_restore: 2515 if (skb_head != skb->data && skb_shared(skb)) { 2516 skb->data = skb_head; 2517 skb->len = skb_len; 2518 } 2519 drop: 2520 sk_skb_reason_drop(sk, skb, drop_reason); 2521 return 0; 2522 2523 drop_n_account: 2524 spin_unlock(&sk->sk_receive_queue.lock); 2525 atomic_inc(&po->tp_drops); 2526 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2527 2528 sk->sk_data_ready(sk); 2529 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2530 goto drop_n_restore; 2531 } 2532 2533 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2534 { 2535 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2536 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2537 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2538 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2539 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2540 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2541 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2542 2543 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2544 return -EINVAL; 2545 2546 return 0; 2547 } 2548 2549 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2550 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2551 { 2552 int ret; 2553 2554 if (*len < vnet_hdr_sz) 2555 return -EINVAL; 2556 *len -= vnet_hdr_sz; 2557 2558 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2559 return -EFAULT; 2560 2561 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2562 if (ret) 2563 return ret; 2564 2565 /* move iter to point to the start of mac header */ 2566 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2567 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2568 2569 return 0; 2570 } 2571 2572 struct tpacket_uarg { 2573 struct ubuf_info ubuf; 2574 struct packet_sock *po; 2575 void *ph; 2576 }; 2577 2578 static void tpacket_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg, 2579 bool success) 2580 { 2581 struct tpacket_uarg *tu = container_of(uarg, struct tpacket_uarg, ubuf); 2582 struct packet_sock *po = tu->po; 2583 void *ph = tu->ph; 2584 __u32 ts; 2585 2586 DEBUG_NET_WARN_ON_ONCE(!skb); 2587 2588 if (!refcount_dec_and_test(&uarg->refcnt)) 2589 return; 2590 2591 ts = __packet_set_timestamp(po, ph, skb); 2592 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2593 2594 packet_dec_pending(&po->tx_ring); 2595 complete(&po->skb_completion); 2596 2597 kfree(tu); 2598 sk_free(&po->sk); 2599 } 2600 2601 static const struct ubuf_info_ops tpacket_ubuf_ops = { 2602 .complete = tpacket_ubuf_complete, 2603 }; 2604 2605 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2606 struct net_device *dev, void *data, int tp_len, 2607 __be16 proto, unsigned char *addr, int hlen, int copylen, 2608 int hard_header_len, 2609 const struct sockcm_cookie *sockc) 2610 { 2611 int to_write, offset, len, nr_frags, len_max; 2612 struct socket *sock = po->sk.sk_socket; 2613 struct page *page; 2614 int err; 2615 2616 if (proto != htons(ETH_P_ALL)) 2617 skb->protocol = proto; 2618 skb->dev = dev; 2619 skb->priority = sockc->priority; 2620 skb->mark = sockc->mark; 2621 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2622 skb_setup_tx_timestamp(skb, sockc); 2623 2624 skb_reserve(skb, hlen); 2625 skb_reset_network_header(skb); 2626 2627 to_write = tp_len; 2628 2629 if (sock->type == SOCK_DGRAM) { 2630 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2631 NULL, tp_len); 2632 if (unlikely(err < 0)) 2633 return -EINVAL; 2634 } else if (copylen) { 2635 int hdrlen = min_t(int, copylen, tp_len); 2636 2637 skb_push(skb, hard_header_len); 2638 skb_put(skb, copylen - hard_header_len); 2639 err = skb_store_bits(skb, 0, data, hdrlen); 2640 if (unlikely(err)) 2641 return err; 2642 if (!dev_validate_header(dev, skb->data, hdrlen)) 2643 return -EINVAL; 2644 2645 data += hdrlen; 2646 to_write -= hdrlen; 2647 } 2648 2649 offset = offset_in_page(data); 2650 len_max = PAGE_SIZE - offset; 2651 len = ((to_write > len_max) ? len_max : to_write); 2652 2653 skb->data_len = to_write; 2654 skb->len += to_write; 2655 skb->truesize += to_write; 2656 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2657 2658 while (likely(to_write)) { 2659 nr_frags = skb_shinfo(skb)->nr_frags; 2660 2661 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2662 pr_err("Packet exceed the number of skb frags(%u)\n", 2663 (unsigned int)MAX_SKB_FRAGS); 2664 return -EFAULT; 2665 } 2666 2667 page = pgv_to_page(data); 2668 data += len; 2669 flush_dcache_page(page); 2670 get_page(page); 2671 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2672 to_write -= len; 2673 offset = 0; 2674 len_max = PAGE_SIZE; 2675 len = ((to_write > len_max) ? len_max : to_write); 2676 } 2677 2678 if (unlikely(!skb->len)) 2679 return -EINVAL; 2680 2681 return tp_len; 2682 } 2683 2684 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2685 int size_max, void **data) 2686 { 2687 union tpacket_uhdr ph; 2688 u32 tp_len; 2689 int off; 2690 2691 ph.raw = frame; 2692 2693 switch (po->tp_version) { 2694 case TPACKET_V3: 2695 if (ph.h3->tp_next_offset != 0) { 2696 pr_warn_once("variable sized slot not supported"); 2697 return -EINVAL; 2698 } 2699 tp_len = ph.h3->tp_len; 2700 break; 2701 case TPACKET_V2: 2702 tp_len = ph.h2->tp_len; 2703 break; 2704 default: 2705 tp_len = ph.h1->tp_len; 2706 break; 2707 } 2708 if (unlikely(tp_len > size_max)) { 2709 pr_err("packet size is too long (%u > %d)\n", tp_len, size_max); 2710 return -EMSGSIZE; 2711 } 2712 2713 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2714 int off_min, off_max; 2715 2716 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2717 off_max = po->tx_ring.frame_size - tp_len; 2718 if (po->sk.sk_type == SOCK_DGRAM) { 2719 switch (po->tp_version) { 2720 case TPACKET_V3: 2721 off = ph.h3->tp_net; 2722 break; 2723 case TPACKET_V2: 2724 off = ph.h2->tp_net; 2725 break; 2726 default: 2727 off = ph.h1->tp_net; 2728 break; 2729 } 2730 } else { 2731 switch (po->tp_version) { 2732 case TPACKET_V3: 2733 off = ph.h3->tp_mac; 2734 break; 2735 case TPACKET_V2: 2736 off = ph.h2->tp_mac; 2737 break; 2738 default: 2739 off = ph.h1->tp_mac; 2740 break; 2741 } 2742 } 2743 if (unlikely((off < off_min) || (off_max < off))) 2744 return -EINVAL; 2745 } else { 2746 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2747 } 2748 2749 *data = frame + off; 2750 return tp_len; 2751 } 2752 2753 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2754 { 2755 struct sk_buff *skb = NULL; 2756 struct net_device *dev; 2757 struct virtio_net_hdr vnet_hdr; 2758 bool has_vnet_hdr = false; 2759 struct sockcm_cookie sockc; 2760 struct tpacket_uarg *uarg; 2761 __be16 proto; 2762 int err, reserve = 0; 2763 void *ph; 2764 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2765 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2766 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2767 unsigned char *addr = NULL; 2768 int tp_len, size_max; 2769 void *data; 2770 int len_sum = 0; 2771 int status = TP_STATUS_AVAILABLE; 2772 int hard_header_len, hlen, tlen, copylen = 0; 2773 long timeo; 2774 2775 mutex_lock(&po->pg_vec_lock); 2776 2777 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2778 * we need to confirm it under protection of pg_vec_lock. 2779 */ 2780 if (unlikely(!po->tx_ring.pg_vec)) { 2781 err = -EBUSY; 2782 goto out; 2783 } 2784 if (likely(saddr == NULL)) { 2785 dev = packet_cached_dev_get(po); 2786 proto = READ_ONCE(po->num); 2787 } else { 2788 err = -EINVAL; 2789 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2790 goto out; 2791 if (msg->msg_namelen < (saddr->sll_halen 2792 + offsetof(struct sockaddr_ll, 2793 sll_addr))) 2794 goto out; 2795 proto = saddr->sll_protocol; 2796 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2797 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2798 if (dev && msg->msg_namelen < dev->addr_len + 2799 offsetof(struct sockaddr_ll, sll_addr)) 2800 goto out_put; 2801 addr = saddr->sll_addr; 2802 } 2803 } 2804 2805 err = -ENXIO; 2806 if (unlikely(dev == NULL)) 2807 goto out; 2808 err = -ENETDOWN; 2809 if (unlikely(!(dev->flags & IFF_UP))) 2810 goto out_put; 2811 2812 sockcm_init(&sockc, &po->sk); 2813 if (msg->msg_controllen) { 2814 err = sock_cmsg_send(&po->sk, msg, &sockc); 2815 if (unlikely(err)) 2816 goto out_put; 2817 } 2818 2819 hard_header_len = READ_ONCE(dev->hard_header_len); 2820 if (po->sk.sk_socket->type == SOCK_RAW) 2821 reserve = hard_header_len; 2822 size_max = po->tx_ring.frame_size 2823 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2824 2825 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2826 size_max = dev->mtu + reserve + VLAN_HLEN; 2827 2828 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2829 reinit_completion(&po->skb_completion); 2830 2831 do { 2832 ph = packet_current_frame(po, &po->tx_ring, 2833 TP_STATUS_SEND_REQUEST); 2834 if (unlikely(ph == NULL)) { 2835 /* Note: packet_read_pending() might be slow if we 2836 * have to call it as it's per_cpu variable, but in 2837 * fast-path we don't have to call it, only when ph 2838 * is NULL, we need to check the pending_refcnt. 2839 */ 2840 if (need_wait && packet_read_pending(&po->tx_ring)) { 2841 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2842 if (timeo <= 0) { 2843 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2844 goto out_put; 2845 } 2846 /* check for additional frames */ 2847 continue; 2848 } else 2849 break; 2850 } 2851 2852 skb = NULL; 2853 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2854 if (tp_len < 0) 2855 goto tpacket_error; 2856 2857 status = TP_STATUS_SEND_REQUEST; 2858 hlen = LL_RESERVED_SPACE_EX(dev, hard_header_len); 2859 tlen = dev->needed_tailroom; 2860 if (vnet_hdr_sz) { 2861 data += vnet_hdr_sz; 2862 tp_len -= vnet_hdr_sz; 2863 if (tp_len < 0) { 2864 tp_len = -EINVAL; 2865 goto tpacket_error; 2866 } 2867 memcpy(&vnet_hdr, data - vnet_hdr_sz, sizeof(vnet_hdr)); 2868 if (__packet_snd_vnet_parse(&vnet_hdr, tp_len)) { 2869 tp_len = -EINVAL; 2870 goto tpacket_error; 2871 } 2872 copylen = __virtio16_to_cpu(vio_le(), 2873 vnet_hdr.hdr_len); 2874 has_vnet_hdr = true; 2875 } 2876 /* Prevent the byte count from wrapping into a negative errno */ 2877 if (unlikely(tp_len > INT_MAX - len_sum)) 2878 break; 2879 copylen = max_t(int, copylen, hard_header_len); 2880 skb = sock_alloc_send_skb(&po->sk, 2881 hlen + tlen + sizeof(struct sockaddr_ll) + 2882 (copylen - hard_header_len), 2883 !need_wait, &err); 2884 2885 if (unlikely(skb == NULL)) { 2886 /* we assume the socket was initially writeable ... */ 2887 if (likely(len_sum > 0)) 2888 err = len_sum; 2889 goto out_status; 2890 } 2891 tp_len = tpacket_fill_skb(po, skb, dev, data, tp_len, proto, 2892 addr, hlen, copylen, hard_header_len, 2893 &sockc); 2894 if (likely(tp_len >= 0) && 2895 tp_len > dev->mtu + reserve && 2896 !vnet_hdr_sz && 2897 !packet_extra_vlan_len_allowed(dev, skb)) 2898 tp_len = -EMSGSIZE; 2899 2900 if (unlikely(tp_len < 0)) { 2901 tpacket_error: 2902 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2903 __packet_set_status(po, ph, 2904 TP_STATUS_AVAILABLE); 2905 packet_increment_head(&po->tx_ring); 2906 kfree_skb(skb); 2907 continue; 2908 } else { 2909 status = TP_STATUS_WRONG_FORMAT; 2910 err = tp_len; 2911 goto out_status; 2912 } 2913 } 2914 2915 if (has_vnet_hdr) { 2916 if (virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le())) { 2917 tp_len = -EINVAL; 2918 goto tpacket_error; 2919 } 2920 } 2921 2922 packet_parse_headers(skb, po->sk.sk_socket); 2923 2924 if (has_vnet_hdr) 2925 virtio_net_hdr_set_proto(skb, &vnet_hdr); 2926 2927 uarg = kmalloc(sizeof(*uarg), GFP_KERNEL); 2928 if (unlikely(!uarg)) { 2929 if (likely(len_sum > 0)) 2930 err = len_sum; 2931 else 2932 err = -ENOMEM; 2933 goto out_status; 2934 } 2935 uarg->po = po; 2936 uarg->ph = ph; 2937 uarg->ubuf.ops = &tpacket_ubuf_ops; 2938 uarg->ubuf.flags = SKBFL_ZEROCOPY_FRAG; 2939 refcount_set(&uarg->ubuf.refcnt, 1); 2940 2941 /* Hold a sk_wmem_alloc reference until completion */ 2942 refcount_inc(&po->sk.sk_wmem_alloc); 2943 skb_zcopy_init(skb, &uarg->ubuf); 2944 2945 __packet_set_status(po, ph, TP_STATUS_SENDING); 2946 packet_inc_pending(&po->tx_ring); 2947 2948 status = TP_STATUS_SEND_REQUEST; 2949 err = packet_xmit(po, skb); 2950 if (unlikely(err != 0)) { 2951 if (err > 0) 2952 err = net_xmit_errno(err); 2953 if (err && __packet_get_status(po, ph) == 2954 TP_STATUS_AVAILABLE) { 2955 /* skb was destructed already */ 2956 skb = NULL; 2957 goto out_status; 2958 } 2959 /* 2960 * skb was dropped but not destructed yet; 2961 * let's treat it like congestion or err < 0 2962 */ 2963 err = 0; 2964 } 2965 packet_increment_head(&po->tx_ring); 2966 len_sum += tp_len; 2967 } while (1); 2968 2969 err = len_sum; 2970 goto out_put; 2971 2972 out_status: 2973 __packet_set_status(po, ph, status); 2974 kfree_skb(skb); 2975 out_put: 2976 dev_put(dev); 2977 out: 2978 mutex_unlock(&po->pg_vec_lock); 2979 return err; 2980 } 2981 2982 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2983 size_t reserve, size_t len, 2984 size_t linear, int noblock, 2985 int *err) 2986 { 2987 struct sk_buff *skb; 2988 2989 /* Under a page? Don't bother with paged skb. */ 2990 if (prepad + len < PAGE_SIZE || !linear) 2991 linear = len; 2992 2993 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2994 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2995 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2996 err, PAGE_ALLOC_COSTLY_ORDER); 2997 if (!skb) 2998 return NULL; 2999 3000 skb_reserve(skb, reserve); 3001 skb_put(skb, linear); 3002 skb->data_len = len - linear; 3003 skb->len += len - linear; 3004 3005 return skb; 3006 } 3007 3008 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 3009 { 3010 struct sock *sk = sock->sk; 3011 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 3012 struct sk_buff *skb; 3013 struct net_device *dev; 3014 __be16 proto; 3015 unsigned char *addr = NULL; 3016 int err, reserve = 0; 3017 struct sockcm_cookie sockc; 3018 struct virtio_net_hdr vnet_hdr = { 0 }; 3019 int offset = 0; 3020 struct packet_sock *po = pkt_sk(sk); 3021 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 3022 int hard_header_len, hlen, tlen, linear; 3023 int extra_len = 0; 3024 3025 /* 3026 * Get and verify the address. 3027 */ 3028 3029 if (likely(saddr == NULL)) { 3030 dev = packet_cached_dev_get(po); 3031 proto = READ_ONCE(po->num); 3032 } else { 3033 err = -EINVAL; 3034 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 3035 goto out; 3036 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 3037 goto out; 3038 proto = saddr->sll_protocol; 3039 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 3040 if (sock->type == SOCK_DGRAM) { 3041 if (dev && msg->msg_namelen < dev->addr_len + 3042 offsetof(struct sockaddr_ll, sll_addr)) 3043 goto out_unlock; 3044 addr = saddr->sll_addr; 3045 } 3046 } 3047 3048 err = -ENXIO; 3049 if (unlikely(dev == NULL)) 3050 goto out_unlock; 3051 err = -ENETDOWN; 3052 if (unlikely(!(dev->flags & IFF_UP))) 3053 goto out_unlock; 3054 3055 sockcm_init(&sockc, sk); 3056 if (msg->msg_controllen) { 3057 err = sock_cmsg_send(sk, msg, &sockc); 3058 if (unlikely(err)) 3059 goto out_unlock; 3060 } 3061 3062 hard_header_len = READ_ONCE(dev->hard_header_len); 3063 if (sock->type == SOCK_RAW) 3064 reserve = hard_header_len; 3065 if (vnet_hdr_sz) { 3066 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3067 if (err) 3068 goto out_unlock; 3069 } 3070 3071 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3072 if (!netif_supports_nofcs(dev)) { 3073 err = -EPROTONOSUPPORT; 3074 goto out_unlock; 3075 } 3076 extra_len = 4; /* We're doing our own CRC */ 3077 } 3078 3079 err = -EMSGSIZE; 3080 if (!vnet_hdr.gso_type && 3081 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3082 goto out_unlock; 3083 3084 err = -ENOBUFS; 3085 hlen = LL_RESERVED_SPACE_EX(dev, hard_header_len); 3086 tlen = dev->needed_tailroom; 3087 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3088 linear = max(linear, min_t(int, len, hard_header_len)); 3089 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3090 msg->msg_flags & MSG_DONTWAIT, &err); 3091 if (skb == NULL) 3092 goto out_unlock; 3093 3094 skb_reset_network_header(skb); 3095 3096 err = -EINVAL; 3097 if (sock->type == SOCK_DGRAM) { 3098 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3099 if (unlikely(offset < 0)) 3100 goto out_free; 3101 } else if (reserve) { 3102 skb_reserve(skb, -reserve); 3103 if (len < reserve + sizeof(struct ipv6hdr) && 3104 dev->min_header_len != hard_header_len) 3105 skb_reset_network_header(skb); 3106 } 3107 3108 /* Returns -EFAULT on error */ 3109 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3110 if (err) 3111 goto out_free; 3112 3113 if ((sock->type == SOCK_RAW && 3114 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3115 err = -EINVAL; 3116 goto out_free; 3117 } 3118 3119 skb_setup_tx_timestamp(skb, &sockc); 3120 3121 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3122 !packet_extra_vlan_len_allowed(dev, skb)) { 3123 err = -EMSGSIZE; 3124 goto out_free; 3125 } 3126 3127 if (proto != htons(ETH_P_ALL)) 3128 skb->protocol = proto; 3129 skb->dev = dev; 3130 skb->priority = sockc.priority; 3131 skb->mark = sockc.mark; 3132 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3133 3134 if (unlikely(extra_len == 4)) 3135 skb->no_fcs = 1; 3136 3137 if (vnet_hdr_sz) { 3138 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3139 if (err) 3140 goto out_free; 3141 len += vnet_hdr_sz; 3142 } 3143 3144 packet_parse_headers(skb, sock); 3145 3146 if (vnet_hdr_sz) 3147 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3148 3149 err = packet_xmit(po, skb); 3150 3151 if (unlikely(err != 0)) { 3152 if (err > 0) 3153 err = net_xmit_errno(err); 3154 if (err) 3155 goto out_unlock; 3156 } 3157 3158 dev_put(dev); 3159 3160 return len; 3161 3162 out_free: 3163 kfree_skb(skb); 3164 out_unlock: 3165 dev_put(dev); 3166 out: 3167 return err; 3168 } 3169 3170 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3171 { 3172 struct sock *sk = sock->sk; 3173 struct packet_sock *po = pkt_sk(sk); 3174 3175 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3176 * tpacket_snd() will redo the check safely. 3177 */ 3178 if (data_race(po->tx_ring.pg_vec)) 3179 return tpacket_snd(po, msg); 3180 3181 return packet_snd(sock, msg, len); 3182 } 3183 3184 /* 3185 * Close a PACKET socket. This is fairly simple. We immediately go 3186 * to 'closed' state and remove our protocol entry in the device list. 3187 */ 3188 3189 static int packet_release(struct socket *sock) 3190 { 3191 struct sock *sk = sock->sk; 3192 struct packet_sock *po; 3193 struct packet_fanout *f; 3194 struct net *net; 3195 union tpacket_req_u req_u; 3196 3197 if (!sk) 3198 return 0; 3199 3200 net = sock_net(sk); 3201 po = pkt_sk(sk); 3202 3203 mutex_lock(&net->packet.sklist_lock); 3204 sk_del_node_init_rcu(sk); 3205 mutex_unlock(&net->packet.sklist_lock); 3206 3207 sock_prot_inuse_add(net, sk->sk_prot, -1); 3208 3209 spin_lock(&po->bind_lock); 3210 unregister_prot_hook(sk, false); 3211 WRITE_ONCE(po->num, 0); 3212 packet_cached_dev_reset(po); 3213 3214 if (po->prot_hook.dev) { 3215 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3216 po->prot_hook.dev = NULL; 3217 } 3218 spin_unlock(&po->bind_lock); 3219 3220 packet_flush_mclist(sk); 3221 3222 lock_sock(sk); 3223 if (po->rx_ring.pg_vec) { 3224 memset(&req_u, 0, sizeof(req_u)); 3225 packet_set_ring(sk, &req_u, 1, 0); 3226 } 3227 3228 if (po->tx_ring.pg_vec) { 3229 memset(&req_u, 0, sizeof(req_u)); 3230 packet_set_ring(sk, &req_u, 1, 1); 3231 } 3232 release_sock(sk); 3233 3234 f = fanout_release(sk); 3235 3236 synchronize_net(); 3237 3238 kfree(po->rollover); 3239 if (f) { 3240 fanout_release_data(f); 3241 kvfree(f); 3242 } 3243 /* 3244 * Now the socket is dead. No more input will appear. 3245 */ 3246 sock_orphan(sk); 3247 sock->sk = NULL; 3248 3249 /* Purge queues */ 3250 3251 skb_queue_purge(&sk->sk_receive_queue); 3252 3253 sock_put(sk); 3254 return 0; 3255 } 3256 3257 /* 3258 * Attach a packet hook. 3259 */ 3260 3261 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3262 __be16 proto) 3263 { 3264 struct packet_sock *po = pkt_sk(sk); 3265 struct net_device *dev = NULL; 3266 bool unlisted = false; 3267 bool need_rehook; 3268 int ret = 0; 3269 3270 lock_sock(sk); 3271 spin_lock(&po->bind_lock); 3272 if (!proto) 3273 proto = po->num; 3274 3275 rcu_read_lock(); 3276 3277 if (po->fanout) { 3278 ret = -EINVAL; 3279 goto out_unlock; 3280 } 3281 3282 if (name) { 3283 dev = dev_get_by_name_rcu(sock_net(sk), name); 3284 if (!dev) { 3285 ret = -ENODEV; 3286 goto out_unlock; 3287 } 3288 } else if (ifindex) { 3289 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3290 if (!dev) { 3291 ret = -ENODEV; 3292 goto out_unlock; 3293 } 3294 } 3295 3296 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3297 3298 if (need_rehook) { 3299 dev_hold(dev); 3300 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3301 rcu_read_unlock(); 3302 /* prevents packet_notifier() from calling 3303 * register_prot_hook() 3304 */ 3305 WRITE_ONCE(po->num, 0); 3306 __unregister_prot_hook(sk, true); 3307 rcu_read_lock(); 3308 if (dev) 3309 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3310 dev->ifindex); 3311 } 3312 3313 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3314 WRITE_ONCE(po->num, proto); 3315 po->prot_hook.type = proto; 3316 3317 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3318 3319 if (unlikely(unlisted)) { 3320 po->prot_hook.dev = NULL; 3321 WRITE_ONCE(po->ifindex, -1); 3322 packet_cached_dev_reset(po); 3323 } else { 3324 netdev_hold(dev, &po->prot_hook.dev_tracker, 3325 GFP_ATOMIC); 3326 po->prot_hook.dev = dev; 3327 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3328 packet_cached_dev_assign(po, dev); 3329 } 3330 dev_put(dev); 3331 } 3332 3333 if (proto == 0 || !need_rehook) 3334 goto out_unlock; 3335 3336 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3337 register_prot_hook(sk); 3338 } else { 3339 sk->sk_err = ENETDOWN; 3340 if (!sock_flag(sk, SOCK_DEAD)) 3341 sk_error_report(sk); 3342 } 3343 3344 out_unlock: 3345 rcu_read_unlock(); 3346 spin_unlock(&po->bind_lock); 3347 release_sock(sk); 3348 return ret; 3349 } 3350 3351 /* 3352 * Bind a packet socket to a device 3353 */ 3354 3355 static int packet_bind_spkt(struct socket *sock, struct sockaddr_unsized *uaddr, 3356 int addr_len) 3357 { 3358 struct sock *sk = sock->sk; 3359 struct sockaddr *sa = (struct sockaddr *)uaddr; 3360 char name[sizeof(sa->sa_data) + 1]; 3361 3362 /* 3363 * Check legality 3364 */ 3365 3366 if (addr_len != sizeof(struct sockaddr)) 3367 return -EINVAL; 3368 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3369 * zero-terminated. 3370 */ 3371 memcpy(name, sa->sa_data, sizeof(sa->sa_data)); 3372 name[sizeof(sa->sa_data)] = 0; 3373 3374 return packet_do_bind(sk, name, 0, 0); 3375 } 3376 3377 static int packet_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len) 3378 { 3379 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3380 struct sock *sk = sock->sk; 3381 3382 /* 3383 * Check legality 3384 */ 3385 3386 if (addr_len < sizeof(struct sockaddr_ll)) 3387 return -EINVAL; 3388 if (sll->sll_family != AF_PACKET) 3389 return -EINVAL; 3390 3391 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3392 } 3393 3394 static struct proto packet_proto = { 3395 .name = "PACKET", 3396 .owner = THIS_MODULE, 3397 .obj_size = sizeof(struct packet_sock), 3398 }; 3399 3400 /* 3401 * Create a packet of type SOCK_PACKET. 3402 */ 3403 3404 static int packet_create(struct net *net, struct socket *sock, int protocol, 3405 int kern) 3406 { 3407 struct sock *sk; 3408 struct packet_sock *po; 3409 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3410 int err; 3411 3412 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3413 return -EPERM; 3414 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3415 sock->type != SOCK_PACKET) 3416 return -ESOCKTNOSUPPORT; 3417 3418 sock->state = SS_UNCONNECTED; 3419 3420 err = -ENOBUFS; 3421 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3422 if (sk == NULL) 3423 goto out; 3424 3425 sock->ops = &packet_ops; 3426 if (sock->type == SOCK_PACKET) 3427 sock->ops = &packet_ops_spkt; 3428 3429 po = pkt_sk(sk); 3430 err = packet_alloc_pending(po); 3431 if (err) 3432 goto out_sk_free; 3433 3434 sock_init_data(sock, sk); 3435 3436 init_completion(&po->skb_completion); 3437 sk->sk_family = PF_PACKET; 3438 po->num = proto; 3439 3440 packet_cached_dev_reset(po); 3441 3442 sk->sk_destruct = packet_sock_destruct; 3443 3444 /* 3445 * Attach a protocol block 3446 */ 3447 3448 spin_lock_init(&po->bind_lock); 3449 mutex_init(&po->pg_vec_lock); 3450 po->rollover = NULL; 3451 po->prot_hook.func = packet_rcv; 3452 3453 if (sock->type == SOCK_PACKET) 3454 po->prot_hook.func = packet_rcv_spkt; 3455 3456 po->prot_hook.af_packet_priv = sk; 3457 po->prot_hook.af_packet_net = sock_net(sk); 3458 3459 if (proto) { 3460 po->prot_hook.type = proto; 3461 __register_prot_hook(sk); 3462 } 3463 3464 mutex_lock(&net->packet.sklist_lock); 3465 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3466 mutex_unlock(&net->packet.sklist_lock); 3467 3468 sock_prot_inuse_add(net, &packet_proto, 1); 3469 3470 return 0; 3471 out_sk_free: 3472 sk_free(sk); 3473 out: 3474 return err; 3475 } 3476 3477 /* 3478 * Pull a packet from our receive queue and hand it to the user. 3479 * If necessary we block. 3480 */ 3481 3482 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3483 int flags) 3484 { 3485 struct sock *sk = sock->sk; 3486 struct sk_buff *skb; 3487 int copied, err; 3488 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3489 unsigned int origlen = 0; 3490 3491 err = -EINVAL; 3492 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3493 goto out; 3494 3495 #if 0 3496 /* What error should we return now? EUNATTACH? */ 3497 if (pkt_sk(sk)->ifindex < 0) 3498 return -ENODEV; 3499 #endif 3500 3501 if (flags & MSG_ERRQUEUE) { 3502 err = sock_recv_errqueue(sk, msg, len, 3503 SOL_PACKET, PACKET_TX_TIMESTAMP); 3504 goto out; 3505 } 3506 3507 /* 3508 * Call the generic datagram receiver. This handles all sorts 3509 * of horrible races and re-entrancy so we can forget about it 3510 * in the protocol layers. 3511 * 3512 * Now it will return ENETDOWN, if device have just gone down, 3513 * but then it will block. 3514 */ 3515 3516 skb = skb_recv_datagram(sk, flags, &err); 3517 3518 /* 3519 * An error occurred so return it. Because skb_recv_datagram() 3520 * handles the blocking we don't see and worry about blocking 3521 * retries. 3522 */ 3523 3524 if (skb == NULL) 3525 goto out; 3526 3527 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3528 3529 if (vnet_hdr_len) { 3530 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3531 if (err) 3532 goto out_free; 3533 } 3534 3535 /* You lose any data beyond the buffer you gave. If it worries 3536 * a user program they can ask the device for its MTU 3537 * anyway. 3538 */ 3539 copied = skb->len; 3540 if (copied > len) { 3541 copied = len; 3542 msg->msg_flags |= MSG_TRUNC; 3543 } 3544 3545 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3546 if (err) 3547 goto out_free; 3548 3549 if (sock->type != SOCK_PACKET) { 3550 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3551 3552 /* Original length was stored in sockaddr_ll fields */ 3553 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3554 sll->sll_family = AF_PACKET; 3555 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3556 vlan_get_protocol_dgram(skb) : skb->protocol; 3557 } 3558 3559 sock_recv_cmsgs(msg, sk, skb); 3560 3561 if (msg->msg_name) { 3562 const size_t max_len = min(sizeof(skb->cb), 3563 sizeof(struct sockaddr_storage)); 3564 int copy_len; 3565 3566 /* If the address length field is there to be filled 3567 * in, we fill it in now. 3568 */ 3569 if (sock->type == SOCK_PACKET) { 3570 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3571 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3572 copy_len = msg->msg_namelen; 3573 } else { 3574 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3575 3576 msg->msg_namelen = sll->sll_halen + 3577 offsetof(struct sockaddr_ll, sll_addr); 3578 copy_len = msg->msg_namelen; 3579 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3580 memset(msg->msg_name + 3581 offsetof(struct sockaddr_ll, sll_addr), 3582 0, sizeof(sll->sll_addr)); 3583 msg->msg_namelen = sizeof(struct sockaddr_ll); 3584 } 3585 } 3586 if (WARN_ON_ONCE(copy_len > max_len)) { 3587 copy_len = max_len; 3588 msg->msg_namelen = copy_len; 3589 } 3590 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3591 } 3592 3593 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3594 struct tpacket_auxdata aux; 3595 3596 aux.tp_status = TP_STATUS_USER; 3597 if (skb->ip_summed == CHECKSUM_PARTIAL) 3598 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3599 else if (skb->pkt_type != PACKET_OUTGOING && 3600 skb_csum_unnecessary(skb)) 3601 aux.tp_status |= TP_STATUS_CSUM_VALID; 3602 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3603 aux.tp_status |= TP_STATUS_GSO_TCP; 3604 3605 aux.tp_len = origlen; 3606 aux.tp_snaplen = skb->len; 3607 aux.tp_mac = 0; 3608 aux.tp_net = skb_network_offset(skb); 3609 if (skb_vlan_tag_present(skb)) { 3610 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3611 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3612 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3613 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3614 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3615 struct net_device *dev; 3616 3617 rcu_read_lock(); 3618 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3619 if (dev) { 3620 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3621 aux.tp_vlan_tpid = ntohs(skb->protocol); 3622 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3623 } else { 3624 aux.tp_vlan_tci = 0; 3625 aux.tp_vlan_tpid = 0; 3626 } 3627 rcu_read_unlock(); 3628 } else { 3629 aux.tp_vlan_tci = 0; 3630 aux.tp_vlan_tpid = 0; 3631 } 3632 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3633 } 3634 3635 /* 3636 * Free or return the buffer as appropriate. Again this 3637 * hides all the races and re-entrancy issues from us. 3638 */ 3639 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3640 3641 out_free: 3642 skb_free_datagram(sk, skb); 3643 out: 3644 return err; 3645 } 3646 3647 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3648 int peer) 3649 { 3650 struct net_device *dev; 3651 struct sock *sk = sock->sk; 3652 3653 if (peer) 3654 return -EOPNOTSUPP; 3655 3656 uaddr->sa_family = AF_PACKET; 3657 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3658 rcu_read_lock(); 3659 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3660 if (dev) 3661 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3662 rcu_read_unlock(); 3663 3664 return sizeof(*uaddr); 3665 } 3666 3667 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3668 int peer) 3669 { 3670 struct net_device *dev; 3671 struct sock *sk = sock->sk; 3672 struct packet_sock *po = pkt_sk(sk); 3673 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3674 int ifindex; 3675 3676 if (peer) 3677 return -EOPNOTSUPP; 3678 3679 ifindex = READ_ONCE(po->ifindex); 3680 sll->sll_family = AF_PACKET; 3681 sll->sll_ifindex = ifindex; 3682 sll->sll_protocol = READ_ONCE(po->num); 3683 sll->sll_pkttype = 0; 3684 rcu_read_lock(); 3685 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3686 if (dev) { 3687 sll->sll_hatype = dev->type; 3688 sll->sll_halen = dev->addr_len; 3689 3690 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3691 memcpy(((struct sockaddr_storage *)sll)->__data + 3692 offsetof(struct sockaddr_ll, sll_addr) - 3693 offsetofend(struct sockaddr_ll, sll_family), 3694 dev->dev_addr, dev->addr_len); 3695 } else { 3696 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3697 sll->sll_halen = 0; 3698 } 3699 rcu_read_unlock(); 3700 3701 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3702 } 3703 3704 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3705 int what) 3706 { 3707 switch (i->type) { 3708 case PACKET_MR_MULTICAST: 3709 if (i->alen != dev->addr_len) 3710 return -EINVAL; 3711 if (what > 0) 3712 return dev_mc_add(dev, i->addr); 3713 else 3714 return dev_mc_del(dev, i->addr); 3715 break; 3716 case PACKET_MR_PROMISC: 3717 return dev_set_promiscuity(dev, what); 3718 case PACKET_MR_ALLMULTI: 3719 return dev_set_allmulti(dev, what); 3720 case PACKET_MR_UNICAST: 3721 if (i->alen != dev->addr_len) 3722 return -EINVAL; 3723 if (what > 0) 3724 return dev_uc_add(dev, i->addr); 3725 else 3726 return dev_uc_del(dev, i->addr); 3727 break; 3728 default: 3729 break; 3730 } 3731 return 0; 3732 } 3733 3734 static void packet_dev_mclist_delete(struct net_device *dev, 3735 struct packet_mclist **mlp, 3736 struct list_head *list) 3737 { 3738 struct packet_mclist *ml; 3739 3740 while ((ml = *mlp) != NULL) { 3741 if (ml->ifindex == dev->ifindex) { 3742 list_add(&ml->remove_list, list); 3743 *mlp = ml->next; 3744 } else 3745 mlp = &ml->next; 3746 } 3747 } 3748 3749 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3750 { 3751 struct packet_sock *po = pkt_sk(sk); 3752 struct packet_mclist *ml, *i; 3753 struct net_device *dev; 3754 int err; 3755 3756 rtnl_lock(); 3757 3758 err = -ENODEV; 3759 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3760 if (!dev) 3761 goto done; 3762 3763 err = -EINVAL; 3764 if (mreq->mr_alen > dev->addr_len) 3765 goto done; 3766 3767 err = -ENOBUFS; 3768 i = kmalloc_obj(*i); 3769 if (i == NULL) 3770 goto done; 3771 3772 err = 0; 3773 for (ml = po->mclist; ml; ml = ml->next) { 3774 if (ml->ifindex == mreq->mr_ifindex && 3775 ml->type == mreq->mr_type && 3776 ml->alen == mreq->mr_alen && 3777 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3778 ml->count++; 3779 /* Free the new element ... */ 3780 kfree(i); 3781 goto done; 3782 } 3783 } 3784 3785 i->type = mreq->mr_type; 3786 i->ifindex = mreq->mr_ifindex; 3787 i->alen = mreq->mr_alen; 3788 memcpy(i->addr, mreq->mr_address, i->alen); 3789 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3790 i->count = 1; 3791 INIT_LIST_HEAD(&i->remove_list); 3792 i->next = po->mclist; 3793 po->mclist = i; 3794 err = packet_dev_mc(dev, i, 1); 3795 if (err) { 3796 po->mclist = i->next; 3797 kfree(i); 3798 } 3799 3800 done: 3801 rtnl_unlock(); 3802 return err; 3803 } 3804 3805 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3806 { 3807 struct packet_mclist *ml, **mlp; 3808 3809 rtnl_lock(); 3810 3811 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3812 if (ml->ifindex == mreq->mr_ifindex && 3813 ml->type == mreq->mr_type && 3814 ml->alen == mreq->mr_alen && 3815 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3816 if (--ml->count == 0) { 3817 struct net_device *dev; 3818 *mlp = ml->next; 3819 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3820 if (dev) 3821 packet_dev_mc(dev, ml, -1); 3822 kfree(ml); 3823 } 3824 break; 3825 } 3826 } 3827 rtnl_unlock(); 3828 return 0; 3829 } 3830 3831 static void packet_flush_mclist(struct sock *sk) 3832 { 3833 struct packet_sock *po = pkt_sk(sk); 3834 struct packet_mclist *ml; 3835 3836 if (!po->mclist) 3837 return; 3838 3839 rtnl_lock(); 3840 while ((ml = po->mclist) != NULL) { 3841 struct net_device *dev; 3842 3843 po->mclist = ml->next; 3844 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3845 if (dev != NULL) 3846 packet_dev_mc(dev, ml, -1); 3847 kfree(ml); 3848 } 3849 rtnl_unlock(); 3850 } 3851 3852 static int 3853 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3854 unsigned int optlen) 3855 { 3856 struct sock *sk = sock->sk; 3857 struct packet_sock *po = pkt_sk(sk); 3858 int ret; 3859 3860 if (level != SOL_PACKET) 3861 return -ENOPROTOOPT; 3862 3863 switch (optname) { 3864 case PACKET_ADD_MEMBERSHIP: 3865 case PACKET_DROP_MEMBERSHIP: 3866 { 3867 struct packet_mreq_max mreq; 3868 int len = optlen; 3869 memset(&mreq, 0, sizeof(mreq)); 3870 if (len < sizeof(struct packet_mreq)) 3871 return -EINVAL; 3872 if (len > sizeof(mreq)) 3873 len = sizeof(mreq); 3874 if (copy_from_sockptr(&mreq, optval, len)) 3875 return -EFAULT; 3876 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3877 return -EINVAL; 3878 if (optname == PACKET_ADD_MEMBERSHIP) 3879 ret = packet_mc_add(sk, &mreq); 3880 else 3881 ret = packet_mc_drop(sk, &mreq); 3882 return ret; 3883 } 3884 3885 case PACKET_RX_RING: 3886 case PACKET_TX_RING: 3887 { 3888 union tpacket_req_u req_u; 3889 3890 ret = -EINVAL; 3891 lock_sock(sk); 3892 switch (po->tp_version) { 3893 case TPACKET_V1: 3894 case TPACKET_V2: 3895 if (optlen < sizeof(req_u.req)) 3896 break; 3897 ret = copy_from_sockptr(&req_u.req, optval, 3898 sizeof(req_u.req)) ? 3899 -EINVAL : 0; 3900 break; 3901 case TPACKET_V3: 3902 default: 3903 if (optlen < sizeof(req_u.req3)) 3904 break; 3905 ret = copy_from_sockptr(&req_u.req3, optval, 3906 sizeof(req_u.req3)) ? 3907 -EINVAL : 0; 3908 break; 3909 } 3910 if (!ret) 3911 ret = packet_set_ring(sk, &req_u, 0, 3912 optname == PACKET_TX_RING); 3913 release_sock(sk); 3914 return ret; 3915 } 3916 case PACKET_COPY_THRESH: 3917 { 3918 int val; 3919 3920 if (optlen != sizeof(val)) 3921 return -EINVAL; 3922 if (copy_from_sockptr(&val, optval, sizeof(val))) 3923 return -EFAULT; 3924 3925 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3926 return 0; 3927 } 3928 case PACKET_VERSION: 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 switch (val) { 3937 case TPACKET_V1: 3938 case TPACKET_V2: 3939 case TPACKET_V3: 3940 break; 3941 default: 3942 return -EINVAL; 3943 } 3944 lock_sock(sk); 3945 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3946 ret = -EBUSY; 3947 } else { 3948 po->tp_version = val; 3949 ret = 0; 3950 } 3951 release_sock(sk); 3952 return ret; 3953 } 3954 case PACKET_RESERVE: 3955 { 3956 unsigned int val; 3957 3958 if (optlen != sizeof(val)) 3959 return -EINVAL; 3960 if (copy_from_sockptr(&val, optval, sizeof(val))) 3961 return -EFAULT; 3962 if (val > INT_MAX) 3963 return -EINVAL; 3964 lock_sock(sk); 3965 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3966 ret = -EBUSY; 3967 } else { 3968 po->tp_reserve = val; 3969 ret = 0; 3970 } 3971 release_sock(sk); 3972 return ret; 3973 } 3974 case PACKET_LOSS: 3975 { 3976 unsigned int val; 3977 3978 if (optlen != sizeof(val)) 3979 return -EINVAL; 3980 if (copy_from_sockptr(&val, optval, sizeof(val))) 3981 return -EFAULT; 3982 3983 lock_sock(sk); 3984 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3985 ret = -EBUSY; 3986 } else { 3987 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3988 ret = 0; 3989 } 3990 release_sock(sk); 3991 return ret; 3992 } 3993 case PACKET_AUXDATA: 3994 { 3995 int val; 3996 3997 if (optlen < sizeof(val)) 3998 return -EINVAL; 3999 if (copy_from_sockptr(&val, optval, sizeof(val))) 4000 return -EFAULT; 4001 4002 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 4003 return 0; 4004 } 4005 case PACKET_ORIGDEV: 4006 { 4007 int val; 4008 4009 if (optlen < sizeof(val)) 4010 return -EINVAL; 4011 if (copy_from_sockptr(&val, optval, sizeof(val))) 4012 return -EFAULT; 4013 4014 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 4015 return 0; 4016 } 4017 case PACKET_VNET_HDR: 4018 case PACKET_VNET_HDR_SZ: 4019 { 4020 int val, hdr_len; 4021 4022 if (sock->type != SOCK_RAW) 4023 return -EINVAL; 4024 if (optlen < sizeof(val)) 4025 return -EINVAL; 4026 if (copy_from_sockptr(&val, optval, sizeof(val))) 4027 return -EFAULT; 4028 4029 if (optname == PACKET_VNET_HDR_SZ) { 4030 if (val && val != sizeof(struct virtio_net_hdr) && 4031 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 4032 return -EINVAL; 4033 hdr_len = val; 4034 } else { 4035 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 4036 } 4037 lock_sock(sk); 4038 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 4039 ret = -EBUSY; 4040 } else { 4041 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 4042 ret = 0; 4043 } 4044 release_sock(sk); 4045 return ret; 4046 } 4047 case PACKET_TIMESTAMP: 4048 { 4049 int val; 4050 4051 if (optlen != sizeof(val)) 4052 return -EINVAL; 4053 if (copy_from_sockptr(&val, optval, sizeof(val))) 4054 return -EFAULT; 4055 4056 WRITE_ONCE(po->tp_tstamp, val); 4057 return 0; 4058 } 4059 case PACKET_FANOUT: 4060 { 4061 struct fanout_args args = { 0 }; 4062 4063 if (optlen != sizeof(int) && optlen != sizeof(args)) 4064 return -EINVAL; 4065 if (copy_from_sockptr(&args, optval, optlen)) 4066 return -EFAULT; 4067 4068 return fanout_add(sk, &args); 4069 } 4070 case PACKET_FANOUT_DATA: 4071 { 4072 /* Paired with the WRITE_ONCE() in fanout_add() */ 4073 if (!READ_ONCE(po->fanout)) 4074 return -EINVAL; 4075 4076 return fanout_set_data(po, optval, optlen); 4077 } 4078 case PACKET_IGNORE_OUTGOING: 4079 { 4080 int val; 4081 4082 if (optlen != sizeof(val)) 4083 return -EINVAL; 4084 if (copy_from_sockptr(&val, optval, sizeof(val))) 4085 return -EFAULT; 4086 if (val < 0 || val > 1) 4087 return -EINVAL; 4088 4089 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4090 return 0; 4091 } 4092 case PACKET_TX_HAS_OFF: 4093 { 4094 unsigned int val; 4095 4096 if (optlen != sizeof(val)) 4097 return -EINVAL; 4098 if (copy_from_sockptr(&val, optval, sizeof(val))) 4099 return -EFAULT; 4100 4101 lock_sock(sk); 4102 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4103 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4104 4105 release_sock(sk); 4106 return 0; 4107 } 4108 case PACKET_QDISC_BYPASS: 4109 { 4110 int val; 4111 4112 if (optlen != sizeof(val)) 4113 return -EINVAL; 4114 if (copy_from_sockptr(&val, optval, sizeof(val))) 4115 return -EFAULT; 4116 4117 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4118 return 0; 4119 } 4120 default: 4121 return -ENOPROTOOPT; 4122 } 4123 } 4124 4125 static int packet_getsockopt(struct socket *sock, int level, int optname, 4126 sockopt_t *opt) 4127 { 4128 int len; 4129 int val, lv = sizeof(val); 4130 struct sock *sk = sock->sk; 4131 struct packet_sock *po = pkt_sk(sk); 4132 void *data = &val; 4133 union tpacket_stats_u st; 4134 struct tpacket_rollover_stats rstats; 4135 int drops; 4136 4137 if (level != SOL_PACKET) 4138 return -ENOPROTOOPT; 4139 4140 len = opt->optlen; 4141 4142 if (len < 0) 4143 return -EINVAL; 4144 4145 switch (optname) { 4146 case PACKET_STATISTICS: 4147 spin_lock_bh(&sk->sk_receive_queue.lock); 4148 memcpy(&st, &po->stats, sizeof(st)); 4149 memset(&po->stats, 0, sizeof(po->stats)); 4150 spin_unlock_bh(&sk->sk_receive_queue.lock); 4151 drops = atomic_xchg(&po->tp_drops, 0); 4152 4153 if (po->tp_version == TPACKET_V3) { 4154 lv = sizeof(struct tpacket_stats_v3); 4155 st.stats3.tp_drops = drops; 4156 st.stats3.tp_packets += drops; 4157 data = &st.stats3; 4158 } else { 4159 lv = sizeof(struct tpacket_stats); 4160 st.stats1.tp_drops = drops; 4161 st.stats1.tp_packets += drops; 4162 data = &st.stats1; 4163 } 4164 4165 break; 4166 case PACKET_AUXDATA: 4167 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4168 break; 4169 case PACKET_ORIGDEV: 4170 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4171 break; 4172 case PACKET_VNET_HDR: 4173 val = !!READ_ONCE(po->vnet_hdr_sz); 4174 break; 4175 case PACKET_VNET_HDR_SZ: 4176 val = READ_ONCE(po->vnet_hdr_sz); 4177 break; 4178 case PACKET_COPY_THRESH: 4179 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4180 break; 4181 case PACKET_VERSION: 4182 val = po->tp_version; 4183 break; 4184 case PACKET_HDRLEN: 4185 if (len > sizeof(int)) 4186 len = sizeof(int); 4187 if (len < sizeof(int)) 4188 return -EINVAL; 4189 if (copy_from_iter(&val, len, &opt->iter_in) != len) 4190 return -EFAULT; 4191 switch (val) { 4192 case TPACKET_V1: 4193 val = sizeof(struct tpacket_hdr); 4194 break; 4195 case TPACKET_V2: 4196 val = sizeof(struct tpacket2_hdr); 4197 break; 4198 case TPACKET_V3: 4199 val = sizeof(struct tpacket3_hdr); 4200 break; 4201 default: 4202 return -EINVAL; 4203 } 4204 break; 4205 case PACKET_RESERVE: 4206 val = po->tp_reserve; 4207 break; 4208 case PACKET_LOSS: 4209 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4210 break; 4211 case PACKET_TIMESTAMP: 4212 val = READ_ONCE(po->tp_tstamp); 4213 break; 4214 case PACKET_FANOUT: 4215 val = (po->fanout ? 4216 ((u32)po->fanout->id | 4217 ((u32)po->fanout->type << 16) | 4218 ((u32)po->fanout->flags << 24)) : 4219 0); 4220 break; 4221 case PACKET_IGNORE_OUTGOING: 4222 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4223 break; 4224 case PACKET_ROLLOVER_STATS: 4225 if (!po->rollover) 4226 return -EINVAL; 4227 rstats.tp_all = atomic_long_read(&po->rollover->num); 4228 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4229 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4230 data = &rstats; 4231 lv = sizeof(rstats); 4232 break; 4233 case PACKET_TX_HAS_OFF: 4234 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4235 break; 4236 case PACKET_QDISC_BYPASS: 4237 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4238 break; 4239 default: 4240 return -ENOPROTOOPT; 4241 } 4242 4243 if (len > lv) 4244 len = lv; 4245 opt->optlen = len; 4246 if (copy_to_iter(data, len, &opt->iter_out) != len) 4247 return -EFAULT; 4248 return 0; 4249 } 4250 4251 static int packet_notifier(struct notifier_block *this, 4252 unsigned long msg, void *ptr) 4253 { 4254 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4255 struct net *net = dev_net(dev); 4256 struct packet_mclist *ml, *tmp; 4257 LIST_HEAD(mclist); 4258 struct sock *sk; 4259 4260 rcu_read_lock(); 4261 sk_for_each_rcu(sk, &net->packet.sklist) { 4262 struct packet_sock *po = pkt_sk(sk); 4263 4264 switch (msg) { 4265 case NETDEV_UNREGISTER: 4266 if (po->mclist) 4267 packet_dev_mclist_delete(dev, &po->mclist, 4268 &mclist); 4269 fallthrough; 4270 4271 case NETDEV_DOWN: 4272 if (dev->ifindex == po->ifindex) { 4273 spin_lock(&po->bind_lock); 4274 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4275 __unregister_prot_hook(sk, false); 4276 sk->sk_err = ENETDOWN; 4277 if (!sock_flag(sk, SOCK_DEAD)) 4278 sk_error_report(sk); 4279 } 4280 if (msg == NETDEV_UNREGISTER) { 4281 packet_cached_dev_reset(po); 4282 WRITE_ONCE(po->ifindex, -1); 4283 netdev_put(po->prot_hook.dev, 4284 &po->prot_hook.dev_tracker); 4285 po->prot_hook.dev = NULL; 4286 } 4287 spin_unlock(&po->bind_lock); 4288 } 4289 break; 4290 case NETDEV_UP: 4291 if (dev->ifindex == po->ifindex) { 4292 spin_lock(&po->bind_lock); 4293 if (po->num) 4294 register_prot_hook(sk); 4295 spin_unlock(&po->bind_lock); 4296 } 4297 break; 4298 } 4299 } 4300 rcu_read_unlock(); 4301 4302 /* packet_dev_mc might grab instance locks so can't run under rcu */ 4303 list_for_each_entry_safe(ml, tmp, &mclist, remove_list) { 4304 packet_dev_mc(dev, ml, -1); 4305 kfree(ml); 4306 } 4307 4308 return NOTIFY_DONE; 4309 } 4310 4311 4312 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4313 unsigned long arg) 4314 { 4315 struct sock *sk = sock->sk; 4316 4317 switch (cmd) { 4318 case SIOCOUTQ: 4319 { 4320 int amount = sk_wmem_alloc_get(sk); 4321 4322 return put_user(amount, (int __user *)arg); 4323 } 4324 case SIOCINQ: 4325 { 4326 struct sk_buff *skb; 4327 int amount = 0; 4328 4329 spin_lock_bh(&sk->sk_receive_queue.lock); 4330 skb = skb_peek(&sk->sk_receive_queue); 4331 if (skb) 4332 amount = skb->len; 4333 spin_unlock_bh(&sk->sk_receive_queue.lock); 4334 return put_user(amount, (int __user *)arg); 4335 } 4336 #ifdef CONFIG_INET 4337 case SIOCADDRT: 4338 case SIOCDELRT: 4339 case SIOCDARP: 4340 case SIOCGARP: 4341 case SIOCSARP: 4342 case SIOCGIFADDR: 4343 case SIOCSIFADDR: 4344 case SIOCGIFBRDADDR: 4345 case SIOCSIFBRDADDR: 4346 case SIOCGIFNETMASK: 4347 case SIOCSIFNETMASK: 4348 case SIOCGIFDSTADDR: 4349 case SIOCSIFDSTADDR: 4350 case SIOCSIFFLAGS: 4351 return inet_dgram_ops.ioctl(sock, cmd, arg); 4352 #endif 4353 4354 default: 4355 return -ENOIOCTLCMD; 4356 } 4357 return 0; 4358 } 4359 4360 static __poll_t packet_poll(struct file *file, struct socket *sock, 4361 poll_table *wait) 4362 { 4363 struct sock *sk = sock->sk; 4364 struct packet_sock *po = pkt_sk(sk); 4365 __poll_t mask = datagram_poll(file, sock, wait); 4366 4367 spin_lock_bh(&sk->sk_receive_queue.lock); 4368 if (po->rx_ring.pg_vec) { 4369 if (!packet_previous_rx_frame(po, &po->rx_ring, 4370 TP_STATUS_KERNEL)) 4371 mask |= EPOLLIN | EPOLLRDNORM; 4372 } 4373 __packet_rcv_try_clear_pressure(po); 4374 spin_unlock_bh(&sk->sk_receive_queue.lock); 4375 spin_lock_bh(&sk->sk_write_queue.lock); 4376 if (po->tx_ring.pg_vec) { 4377 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4378 mask |= EPOLLOUT | EPOLLWRNORM; 4379 } 4380 spin_unlock_bh(&sk->sk_write_queue.lock); 4381 return mask; 4382 } 4383 4384 4385 /* Dirty? Well, I still did not learn better way to account 4386 * for user mmaps. 4387 */ 4388 4389 static void packet_mm_open(struct vm_area_struct *vma) 4390 { 4391 struct file *file = vma->vm_file; 4392 struct socket *sock = file->private_data; 4393 struct sock *sk = sock->sk; 4394 4395 if (sk) 4396 atomic_long_inc(&pkt_sk(sk)->mapped); 4397 } 4398 4399 static void packet_mm_close(struct vm_area_struct *vma) 4400 { 4401 struct file *file = vma->vm_file; 4402 struct socket *sock = file->private_data; 4403 struct sock *sk = sock->sk; 4404 4405 if (sk) 4406 atomic_long_dec(&pkt_sk(sk)->mapped); 4407 } 4408 4409 static const struct vm_operations_struct packet_mmap_ops = { 4410 .open = packet_mm_open, 4411 .close = packet_mm_close, 4412 }; 4413 4414 struct packet_pg_vec { 4415 struct packet_pg_vec_free *deferred; 4416 unsigned int order; 4417 unsigned int len; 4418 struct pgv pg_vec[] __counted_by(len); 4419 }; 4420 4421 struct packet_pg_vec_free { 4422 struct delayed_work work; 4423 struct sock *sk; 4424 struct packet_pg_vec *vec; 4425 }; 4426 4427 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4428 unsigned int len) 4429 { 4430 struct packet_pg_vec *vec; 4431 int i; 4432 4433 vec = container_of_const(pg_vec, struct packet_pg_vec, pg_vec[0]); 4434 for (i = 0; i < len; i++) { 4435 if (likely(pg_vec[i].buffer)) { 4436 if (is_vmalloc_addr(pg_vec[i].buffer)) 4437 vfree(pg_vec[i].buffer); 4438 else 4439 free_pages((unsigned long)pg_vec[i].buffer, 4440 order); 4441 pg_vec[i].buffer = NULL; 4442 } 4443 } 4444 kfree(vec->deferred); 4445 kfree(vec); 4446 } 4447 4448 static void packet_free_pg_vec_work(struct work_struct *work) 4449 { 4450 struct packet_pg_vec_free *deferred; 4451 struct packet_pg_vec *vec; 4452 struct sock *sk; 4453 4454 deferred = container_of_const(to_delayed_work(work), 4455 struct packet_pg_vec_free, work); 4456 vec = deferred->vec; 4457 sk = deferred->sk; 4458 if (sk_wmem_alloc_get(sk)) { 4459 queue_delayed_work(system_long_wq, &deferred->work, 1); 4460 return; 4461 } 4462 4463 free_pg_vec(vec->pg_vec, vec->order, vec->len); 4464 sock_put(sk); 4465 } 4466 4467 static void packet_free_tx_ring(struct sock *sk, struct pgv *pg_vec, 4468 unsigned int order, unsigned int len) 4469 { 4470 struct packet_pg_vec_free *deferred; 4471 struct packet_pg_vec *vec; 4472 4473 vec = container_of_const(pg_vec, struct packet_pg_vec, pg_vec[0]); 4474 deferred = vec->deferred; 4475 if (!deferred || !sk_wmem_alloc_get(sk)) { 4476 free_pg_vec(pg_vec, order, len); 4477 return; 4478 } 4479 4480 /* A detached ring's pending count can miss late skb destructors. */ 4481 deferred->sk = sk; 4482 sock_hold(sk); 4483 queue_delayed_work(system_long_wq, &deferred->work, 0); 4484 } 4485 4486 static char *alloc_one_pg_vec_page(unsigned long order) 4487 { 4488 char *buffer; 4489 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4490 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4491 4492 buffer = (char *) __get_free_pages(gfp_flags, order); 4493 if (buffer) 4494 return buffer; 4495 4496 /* __get_free_pages failed, fall back to vmalloc */ 4497 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4498 if (buffer) 4499 return buffer; 4500 4501 /* vmalloc failed, lets dig into swap here */ 4502 gfp_flags &= ~__GFP_NORETRY; 4503 buffer = (char *) __get_free_pages(gfp_flags, order); 4504 if (buffer) 4505 return buffer; 4506 4507 /* complete and utter failure */ 4508 return NULL; 4509 } 4510 4511 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order, bool tx_ring) 4512 { 4513 unsigned int block_nr = req->tp_block_nr; 4514 struct packet_pg_vec *vec; 4515 struct pgv *pg_vec; 4516 int i; 4517 4518 vec = kzalloc_flex(*vec, pg_vec, block_nr, GFP_KERNEL | __GFP_NOWARN); 4519 if (unlikely(!vec)) 4520 return NULL; 4521 vec->order = order; 4522 vec->len = block_nr; 4523 pg_vec = vec->pg_vec; 4524 4525 if (tx_ring) { 4526 vec->deferred = kzalloc_obj(*vec->deferred, 4527 GFP_KERNEL | __GFP_NOWARN); 4528 if (!vec->deferred) 4529 goto out_free_pgvec; 4530 vec->deferred->vec = vec; 4531 INIT_DELAYED_WORK(&vec->deferred->work, 4532 packet_free_pg_vec_work); 4533 } 4534 4535 for (i = 0; i < block_nr; i++) { 4536 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4537 if (unlikely(!pg_vec[i].buffer)) 4538 goto out_free_pgvec; 4539 } 4540 4541 out: 4542 return pg_vec; 4543 4544 out_free_pgvec: 4545 free_pg_vec(pg_vec, order, block_nr); 4546 pg_vec = NULL; 4547 goto out; 4548 } 4549 4550 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4551 int closing, int tx_ring) 4552 { 4553 struct pgv *pg_vec = NULL; 4554 struct packet_sock *po = pkt_sk(sk); 4555 unsigned long *rx_owner_map = NULL; 4556 int was_running, order = 0; 4557 struct packet_ring_buffer *rb; 4558 struct sk_buff_head *rb_queue; 4559 __be16 num; 4560 int err; 4561 /* Added to avoid minimal code churn */ 4562 struct tpacket_req *req = &req_u->req; 4563 4564 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4565 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4566 4567 err = -EBUSY; 4568 if (!closing) { 4569 if (atomic_long_read(&po->mapped)) 4570 goto out; 4571 if (packet_read_pending(rb)) 4572 goto out; 4573 } 4574 4575 if (req->tp_block_nr) { 4576 unsigned int min_frame_size; 4577 4578 /* Sanity tests and some calculations */ 4579 err = -EBUSY; 4580 if (unlikely(rb->pg_vec)) 4581 goto out; 4582 4583 switch (po->tp_version) { 4584 case TPACKET_V1: 4585 po->tp_hdrlen = TPACKET_HDRLEN; 4586 break; 4587 case TPACKET_V2: 4588 po->tp_hdrlen = TPACKET2_HDRLEN; 4589 break; 4590 case TPACKET_V3: 4591 po->tp_hdrlen = TPACKET3_HDRLEN; 4592 break; 4593 } 4594 4595 err = -EINVAL; 4596 if (unlikely((int)req->tp_block_size <= 0)) 4597 goto out; 4598 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4599 goto out; 4600 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4601 if (po->tp_version >= TPACKET_V3 && 4602 req->tp_block_size < 4603 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4604 goto out; 4605 if (unlikely(req->tp_frame_size < min_frame_size)) 4606 goto out; 4607 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4608 goto out; 4609 4610 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4611 if (unlikely(rb->frames_per_block == 0)) 4612 goto out; 4613 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4614 goto out; 4615 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4616 req->tp_frame_nr)) 4617 goto out; 4618 4619 err = -ENOMEM; 4620 order = get_order(req->tp_block_size); 4621 pg_vec = alloc_pg_vec(req, order, tx_ring); 4622 if (unlikely(!pg_vec)) 4623 goto out; 4624 switch (po->tp_version) { 4625 case TPACKET_V3: 4626 /* Block transmit is not supported yet */ 4627 if (!tx_ring) { 4628 init_prb_bdqc(po, rb, pg_vec, req_u); 4629 } else { 4630 struct tpacket_req3 *req3 = &req_u->req3; 4631 4632 if (req3->tp_retire_blk_tov || 4633 req3->tp_sizeof_priv || 4634 req3->tp_feature_req_word) { 4635 err = -EINVAL; 4636 goto out_free_pg_vec; 4637 } 4638 } 4639 break; 4640 default: 4641 if (!tx_ring) { 4642 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4643 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4644 if (!rx_owner_map) 4645 goto out_free_pg_vec; 4646 } 4647 break; 4648 } 4649 } 4650 /* Done */ 4651 else { 4652 err = -EINVAL; 4653 if (unlikely(req->tp_frame_nr)) 4654 goto out; 4655 } 4656 4657 4658 /* Detach socket from network */ 4659 spin_lock(&po->bind_lock); 4660 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4661 num = po->num; 4662 WRITE_ONCE(po->num, 0); 4663 if (was_running) 4664 __unregister_prot_hook(sk, false); 4665 4666 spin_unlock(&po->bind_lock); 4667 4668 synchronize_net(); 4669 4670 err = -EBUSY; 4671 mutex_lock(&po->pg_vec_lock); 4672 if (closing || atomic_long_read(&po->mapped) == 0) { 4673 if (tx_ring && !closing && packet_read_pending(rb)) 4674 goto out_unlock; 4675 4676 err = 0; 4677 spin_lock_bh(&rb_queue->lock); 4678 swap(rb->pg_vec, pg_vec); 4679 if (po->tp_version <= TPACKET_V2) 4680 swap(rb->rx_owner_map, rx_owner_map); 4681 rb->frame_max = (req->tp_frame_nr - 1); 4682 rb->head = 0; 4683 rb->frame_size = req->tp_frame_size; 4684 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4685 tpacket_rcv : packet_rcv; 4686 spin_unlock_bh(&rb_queue->lock); 4687 4688 swap(rb->pg_vec_order, order); 4689 swap(rb->pg_vec_len, req->tp_block_nr); 4690 4691 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4692 skb_queue_purge(rb_queue); 4693 if (atomic_long_read(&po->mapped)) 4694 pr_err("packet_mmap: vma is busy: %ld\n", 4695 atomic_long_read(&po->mapped)); 4696 } 4697 out_unlock: 4698 mutex_unlock(&po->pg_vec_lock); 4699 4700 spin_lock(&po->bind_lock); 4701 WRITE_ONCE(po->num, num); 4702 /* 4703 * NETDEV_UNREGISTER may have invalidated the binding while bind_lock 4704 * was dropped above. Do not re-add a fanout hook to a dead device. 4705 */ 4706 if (was_running && READ_ONCE(po->ifindex) != -1) 4707 register_prot_hook(sk); 4708 4709 spin_unlock(&po->bind_lock); 4710 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4711 /* Because we don't support block-based V3 on tx-ring */ 4712 if (!tx_ring) 4713 prb_shutdown_retire_blk_timer(po, rb_queue); 4714 } 4715 4716 out_free_pg_vec: 4717 if (pg_vec) { 4718 bitmap_free(rx_owner_map); 4719 if (tx_ring && closing) 4720 packet_free_tx_ring(sk, pg_vec, order, req->tp_block_nr); 4721 else 4722 free_pg_vec(pg_vec, order, req->tp_block_nr); 4723 } 4724 out: 4725 return err; 4726 } 4727 4728 static int packet_mmap(struct file *file, struct socket *sock, 4729 struct vm_area_struct *vma) 4730 { 4731 struct sock *sk = sock->sk; 4732 struct packet_sock *po = pkt_sk(sk); 4733 unsigned long size, expected_size; 4734 struct packet_ring_buffer *rb; 4735 unsigned long start; 4736 int err = -EINVAL; 4737 int i; 4738 4739 if (vma->vm_pgoff) 4740 return -EINVAL; 4741 4742 mutex_lock(&po->pg_vec_lock); 4743 4744 expected_size = 0; 4745 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4746 if (rb->pg_vec) { 4747 expected_size += rb->pg_vec_len 4748 * rb->pg_vec_pages 4749 * PAGE_SIZE; 4750 } 4751 } 4752 4753 if (expected_size == 0) 4754 goto out; 4755 4756 size = vma->vm_end - vma->vm_start; 4757 if (size != expected_size) 4758 goto out; 4759 4760 start = vma->vm_start; 4761 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4762 if (rb->pg_vec == NULL) 4763 continue; 4764 4765 for (i = 0; i < rb->pg_vec_len; i++) { 4766 struct page *page; 4767 void *kaddr = rb->pg_vec[i].buffer; 4768 int pg_num; 4769 4770 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4771 page = pgv_to_page(kaddr); 4772 err = vm_insert_page(vma, start, page); 4773 if (unlikely(err)) 4774 goto out; 4775 start += PAGE_SIZE; 4776 kaddr += PAGE_SIZE; 4777 } 4778 } 4779 } 4780 4781 atomic_long_inc(&po->mapped); 4782 vma->vm_ops = &packet_mmap_ops; 4783 err = 0; 4784 4785 out: 4786 mutex_unlock(&po->pg_vec_lock); 4787 return err; 4788 } 4789 4790 static const struct proto_ops packet_ops_spkt = { 4791 .family = PF_PACKET, 4792 .owner = THIS_MODULE, 4793 .release = packet_release, 4794 .bind = packet_bind_spkt, 4795 .connect = sock_no_connect, 4796 .socketpair = sock_no_socketpair, 4797 .accept = sock_no_accept, 4798 .getname = packet_getname_spkt, 4799 .poll = datagram_poll, 4800 .ioctl = packet_ioctl, 4801 .gettstamp = sock_gettstamp, 4802 .listen = sock_no_listen, 4803 .shutdown = sock_no_shutdown, 4804 .sendmsg = packet_sendmsg_spkt, 4805 .recvmsg = packet_recvmsg, 4806 .mmap = sock_no_mmap, 4807 }; 4808 4809 static const struct proto_ops packet_ops = { 4810 .family = PF_PACKET, 4811 .owner = THIS_MODULE, 4812 .release = packet_release, 4813 .bind = packet_bind, 4814 .connect = sock_no_connect, 4815 .socketpair = sock_no_socketpair, 4816 .accept = sock_no_accept, 4817 .getname = packet_getname, 4818 .poll = packet_poll, 4819 .ioctl = packet_ioctl, 4820 .gettstamp = sock_gettstamp, 4821 .listen = sock_no_listen, 4822 .shutdown = sock_no_shutdown, 4823 .setsockopt = packet_setsockopt, 4824 .getsockopt_iter = packet_getsockopt, 4825 .sendmsg = packet_sendmsg, 4826 .recvmsg = packet_recvmsg, 4827 .mmap = packet_mmap, 4828 }; 4829 4830 static const struct net_proto_family packet_family_ops = { 4831 .family = PF_PACKET, 4832 .create = packet_create, 4833 .owner = THIS_MODULE, 4834 }; 4835 4836 static struct notifier_block packet_netdev_notifier = { 4837 .notifier_call = packet_notifier, 4838 }; 4839 4840 #ifdef CONFIG_PROC_FS 4841 4842 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4843 __acquires(RCU) 4844 { 4845 struct net *net = seq_file_net(seq); 4846 4847 rcu_read_lock(); 4848 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4849 } 4850 4851 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4852 { 4853 struct net *net = seq_file_net(seq); 4854 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4855 } 4856 4857 static void packet_seq_stop(struct seq_file *seq, void *v) 4858 __releases(RCU) 4859 { 4860 rcu_read_unlock(); 4861 } 4862 4863 static int packet_seq_show(struct seq_file *seq, void *v) 4864 { 4865 if (v == SEQ_START_TOKEN) 4866 seq_printf(seq, 4867 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4868 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4869 else { 4870 struct sock *s = sk_entry(v); 4871 const struct packet_sock *po = pkt_sk(s); 4872 4873 seq_printf(seq, 4874 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6llu\n", 4875 s, 4876 refcount_read(&s->sk_refcnt), 4877 s->sk_type, 4878 ntohs(READ_ONCE(po->num)), 4879 READ_ONCE(po->ifindex), 4880 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4881 atomic_read(&s->sk_rmem_alloc), 4882 from_kuid_munged(seq_user_ns(seq), sk_uid(s)), 4883 sock_i_ino(s)); 4884 } 4885 4886 return 0; 4887 } 4888 4889 static const struct seq_operations packet_seq_ops = { 4890 .start = packet_seq_start, 4891 .next = packet_seq_next, 4892 .stop = packet_seq_stop, 4893 .show = packet_seq_show, 4894 }; 4895 #endif 4896 4897 static int __net_init packet_net_init(struct net *net) 4898 { 4899 mutex_init(&net->packet.sklist_lock); 4900 INIT_HLIST_HEAD(&net->packet.sklist); 4901 4902 #ifdef CONFIG_PROC_FS 4903 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4904 sizeof(struct seq_net_private))) 4905 return -ENOMEM; 4906 #endif /* CONFIG_PROC_FS */ 4907 4908 return 0; 4909 } 4910 4911 static void __net_exit packet_net_exit(struct net *net) 4912 { 4913 remove_proc_entry("packet", net->proc_net); 4914 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4915 } 4916 4917 static struct pernet_operations packet_net_ops = { 4918 .init = packet_net_init, 4919 .exit = packet_net_exit, 4920 }; 4921 4922 4923 static void __exit packet_exit(void) 4924 { 4925 sock_unregister(PF_PACKET); 4926 proto_unregister(&packet_proto); 4927 unregister_netdevice_notifier(&packet_netdev_notifier); 4928 unregister_pernet_subsys(&packet_net_ops); 4929 } 4930 4931 static int __init packet_init(void) 4932 { 4933 int rc; 4934 4935 rc = register_pernet_subsys(&packet_net_ops); 4936 if (rc) 4937 goto out; 4938 rc = register_netdevice_notifier(&packet_netdev_notifier); 4939 if (rc) 4940 goto out_pernet; 4941 rc = proto_register(&packet_proto, 0); 4942 if (rc) 4943 goto out_notifier; 4944 rc = sock_register(&packet_family_ops); 4945 if (rc) 4946 goto out_proto; 4947 4948 return 0; 4949 4950 out_proto: 4951 proto_unregister(&packet_proto); 4952 out_notifier: 4953 unregister_netdevice_notifier(&packet_netdev_notifier); 4954 out_pernet: 4955 unregister_pernet_subsys(&packet_net_ops); 4956 out: 4957 return rc; 4958 } 4959 4960 module_init(packet_init); 4961 module_exit(packet_exit); 4962 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4963 MODULE_LICENSE("GPL"); 4964 MODULE_ALIAS_NETPROTO(PF_PACKET); 4965