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/filter.h> 53 #include <linux/types.h> 54 #include <linux/mm.h> 55 #include <linux/capability.h> 56 #include <linux/fcntl.h> 57 #include <linux/socket.h> 58 #include <linux/in.h> 59 #include <linux/inet.h> 60 #include <linux/netdevice.h> 61 #include <linux/if_packet.h> 62 #include <linux/wireless.h> 63 #include <linux/kernel.h> 64 #include <linux/kmod.h> 65 #include <linux/slab.h> 66 #include <linux/vmalloc.h> 67 #include <net/net_namespace.h> 68 #include <net/ip.h> 69 #include <net/protocol.h> 70 #include <linux/skbuff.h> 71 #include <net/sock.h> 72 #include <linux/errno.h> 73 #include <linux/timer.h> 74 #include <linux/uaccess.h> 75 #include <asm/ioctls.h> 76 #include <asm/page.h> 77 #include <asm/cacheflush.h> 78 #include <asm/io.h> 79 #include <linux/proc_fs.h> 80 #include <linux/seq_file.h> 81 #include <linux/poll.h> 82 #include <linux/module.h> 83 #include <linux/init.h> 84 #include <linux/mutex.h> 85 #include <linux/if_vlan.h> 86 #include <linux/virtio_net.h> 87 #include <linux/errqueue.h> 88 #include <linux/net_tstamp.h> 89 #include <linux/percpu.h> 90 #ifdef CONFIG_INET 91 #include <net/inet_common.h> 92 #endif 93 #include <linux/bpf.h> 94 #include <net/compat.h> 95 #include <linux/netfilter_netdev.h> 96 97 #include "internal.h" 98 99 /* 100 Assumptions: 101 - If the device has no dev->header_ops->create, there is no LL header 102 visible above the device. In this case, its hard_header_len should be 0. 103 The device may prepend its own header internally. In this case, its 104 needed_headroom should be set to the space needed for it to add its 105 internal header. 106 For example, a WiFi driver pretending to be an Ethernet driver should 107 set its hard_header_len to be the Ethernet header length, and set its 108 needed_headroom to be (the real WiFi header length - the fake Ethernet 109 header length). 110 - packet socket receives packets with pulled ll header, 111 so that SOCK_RAW should push it back. 112 113 On receive: 114 ----------- 115 116 Incoming, dev_has_header(dev) == true 117 mac_header -> ll header 118 data -> data 119 120 Outgoing, dev_has_header(dev) == true 121 mac_header -> ll header 122 data -> ll header 123 124 Incoming, dev_has_header(dev) == false 125 mac_header -> data 126 However drivers often make it point to the ll header. 127 This is incorrect because the ll header should be invisible to us. 128 data -> data 129 130 Outgoing, dev_has_header(dev) == false 131 mac_header -> data. ll header is invisible to us. 132 data -> data 133 134 Resume 135 If dev_has_header(dev) == false we are unable to restore the ll header, 136 because it is invisible to us. 137 138 139 On transmit: 140 ------------ 141 142 dev_has_header(dev) == true 143 mac_header -> ll header 144 data -> ll header 145 146 dev_has_header(dev) == false (ll header is invisible to us) 147 mac_header -> data 148 data -> data 149 150 We should set network_header on output to the correct position, 151 packet classifier depends on it. 152 */ 153 154 /* Private packet socket structures. */ 155 156 /* identical to struct packet_mreq except it has 157 * a longer address field. 158 */ 159 struct packet_mreq_max { 160 int mr_ifindex; 161 unsigned short mr_type; 162 unsigned short mr_alen; 163 unsigned char mr_address[MAX_ADDR_LEN]; 164 }; 165 166 union tpacket_uhdr { 167 struct tpacket_hdr *h1; 168 struct tpacket2_hdr *h2; 169 struct tpacket3_hdr *h3; 170 void *raw; 171 }; 172 173 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 174 int closing, int tx_ring); 175 176 #define V3_ALIGNMENT (8) 177 178 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 179 180 #define BLK_PLUS_PRIV(sz_of_priv) \ 181 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 182 183 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 184 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 185 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 186 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 187 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 188 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 189 190 struct packet_sock; 191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 192 struct packet_type *pt, struct net_device *orig_dev); 193 194 static void *packet_previous_frame(struct packet_sock *po, 195 struct packet_ring_buffer *rb, 196 int status); 197 static void packet_increment_head(struct packet_ring_buffer *buff); 198 static int prb_curr_blk_in_use(struct tpacket_block_desc *); 199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 200 struct packet_sock *); 201 static void prb_retire_current_block(struct tpacket_kbdq_core *, 202 struct packet_sock *, unsigned int status); 203 static int prb_queue_frozen(struct tpacket_kbdq_core *); 204 static void prb_open_block(struct tpacket_kbdq_core *, 205 struct tpacket_block_desc *); 206 static void prb_retire_rx_blk_timer_expired(struct timer_list *); 207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 208 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 209 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 210 struct tpacket3_hdr *); 211 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 212 struct tpacket3_hdr *); 213 static void packet_flush_mclist(struct sock *sk); 214 static u16 packet_pick_tx_queue(struct sk_buff *skb); 215 216 struct packet_skb_cb { 217 union { 218 struct sockaddr_pkt pkt; 219 union { 220 /* Trick: alias skb original length with 221 * ll.sll_family and ll.protocol in order 222 * to save room. 223 */ 224 unsigned int origlen; 225 struct sockaddr_ll ll; 226 }; 227 } sa; 228 }; 229 230 #define vio_le() virtio_legacy_is_little_endian() 231 232 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 233 234 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 235 #define GET_PBLOCK_DESC(x, bid) \ 236 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 237 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 238 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 239 #define GET_NEXT_PRB_BLK_NUM(x) \ 240 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 241 ((x)->kactive_blk_num+1) : 0) 242 243 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 244 static void __fanout_link(struct sock *sk, struct packet_sock *po); 245 246 #ifdef CONFIG_NETFILTER_EGRESS 247 static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb) 248 { 249 struct sk_buff *next, *head = NULL, *tail; 250 int rc; 251 252 rcu_read_lock(); 253 for (; skb != NULL; skb = next) { 254 next = skb->next; 255 skb_mark_not_on_list(skb); 256 257 if (!nf_hook_egress(skb, &rc, skb->dev)) 258 continue; 259 260 if (!head) 261 head = skb; 262 else 263 tail->next = skb; 264 265 tail = skb; 266 } 267 rcu_read_unlock(); 268 269 return head; 270 } 271 #endif 272 273 static int packet_xmit(const struct packet_sock *po, struct sk_buff *skb) 274 { 275 if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS)) 276 return dev_queue_xmit(skb); 277 278 #ifdef CONFIG_NETFILTER_EGRESS 279 if (nf_hook_egress_active()) { 280 skb = nf_hook_direct_egress(skb); 281 if (!skb) 282 return NET_XMIT_DROP; 283 } 284 #endif 285 return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); 286 } 287 288 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 289 { 290 struct net_device *dev; 291 292 rcu_read_lock(); 293 dev = rcu_dereference(po->cached_dev); 294 dev_hold(dev); 295 rcu_read_unlock(); 296 297 return dev; 298 } 299 300 static void packet_cached_dev_assign(struct packet_sock *po, 301 struct net_device *dev) 302 { 303 rcu_assign_pointer(po->cached_dev, dev); 304 } 305 306 static void packet_cached_dev_reset(struct packet_sock *po) 307 { 308 RCU_INIT_POINTER(po->cached_dev, NULL); 309 } 310 311 static u16 packet_pick_tx_queue(struct sk_buff *skb) 312 { 313 struct net_device *dev = skb->dev; 314 const struct net_device_ops *ops = dev->netdev_ops; 315 int cpu = raw_smp_processor_id(); 316 u16 queue_index; 317 318 #ifdef CONFIG_XPS 319 skb->sender_cpu = cpu + 1; 320 #endif 321 skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues); 322 if (ops->ndo_select_queue) { 323 queue_index = ops->ndo_select_queue(dev, skb, NULL); 324 queue_index = netdev_cap_txqueue(dev, queue_index); 325 } else { 326 queue_index = netdev_pick_tx(dev, skb, NULL); 327 } 328 329 return queue_index; 330 } 331 332 /* __register_prot_hook must be invoked through register_prot_hook 333 * or from a context in which asynchronous accesses to the packet 334 * socket is not possible (packet_create()). 335 */ 336 static void __register_prot_hook(struct sock *sk) 337 { 338 struct packet_sock *po = pkt_sk(sk); 339 340 if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 341 if (po->fanout) 342 __fanout_link(sk, po); 343 else 344 dev_add_pack(&po->prot_hook); 345 346 sock_hold(sk); 347 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1); 348 } 349 } 350 351 static void register_prot_hook(struct sock *sk) 352 { 353 lockdep_assert_held_once(&pkt_sk(sk)->bind_lock); 354 __register_prot_hook(sk); 355 } 356 357 /* If the sync parameter is true, we will temporarily drop 358 * the po->bind_lock and do a synchronize_net to make sure no 359 * asynchronous packet processing paths still refer to the elements 360 * of po->prot_hook. If the sync parameter is false, it is the 361 * callers responsibility to take care of this. 362 */ 363 static void __unregister_prot_hook(struct sock *sk, bool sync) 364 { 365 struct packet_sock *po = pkt_sk(sk); 366 367 lockdep_assert_held_once(&po->bind_lock); 368 369 packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0); 370 371 if (po->fanout) 372 __fanout_unlink(sk, po); 373 else 374 __dev_remove_pack(&po->prot_hook); 375 376 __sock_put(sk); 377 378 if (sync) { 379 spin_unlock(&po->bind_lock); 380 synchronize_net(); 381 spin_lock(&po->bind_lock); 382 } 383 } 384 385 static void unregister_prot_hook(struct sock *sk, bool sync) 386 { 387 struct packet_sock *po = pkt_sk(sk); 388 389 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) 390 __unregister_prot_hook(sk, sync); 391 } 392 393 static inline struct page * __pure pgv_to_page(void *addr) 394 { 395 if (is_vmalloc_addr(addr)) 396 return vmalloc_to_page(addr); 397 return virt_to_page(addr); 398 } 399 400 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 401 { 402 union tpacket_uhdr h; 403 404 /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */ 405 406 h.raw = frame; 407 switch (po->tp_version) { 408 case TPACKET_V1: 409 WRITE_ONCE(h.h1->tp_status, status); 410 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 411 break; 412 case TPACKET_V2: 413 WRITE_ONCE(h.h2->tp_status, status); 414 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 415 break; 416 case TPACKET_V3: 417 WRITE_ONCE(h.h3->tp_status, status); 418 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 419 break; 420 default: 421 WARN(1, "TPACKET version not supported.\n"); 422 BUG(); 423 } 424 425 smp_wmb(); 426 } 427 428 static int __packet_get_status(const struct packet_sock *po, void *frame) 429 { 430 union tpacket_uhdr h; 431 432 smp_rmb(); 433 434 /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */ 435 436 h.raw = frame; 437 switch (po->tp_version) { 438 case TPACKET_V1: 439 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 440 return READ_ONCE(h.h1->tp_status); 441 case TPACKET_V2: 442 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 443 return READ_ONCE(h.h2->tp_status); 444 case TPACKET_V3: 445 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 446 return READ_ONCE(h.h3->tp_status); 447 default: 448 WARN(1, "TPACKET version not supported.\n"); 449 BUG(); 450 return 0; 451 } 452 } 453 454 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, 455 unsigned int flags) 456 { 457 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 458 459 if (shhwtstamps && 460 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 461 ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts)) 462 return TP_STATUS_TS_RAW_HARDWARE; 463 464 if ((flags & SOF_TIMESTAMPING_SOFTWARE) && 465 ktime_to_timespec64_cond(skb_tstamp(skb), ts)) 466 return TP_STATUS_TS_SOFTWARE; 467 468 return 0; 469 } 470 471 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 472 struct sk_buff *skb) 473 { 474 union tpacket_uhdr h; 475 struct timespec64 ts; 476 __u32 ts_status; 477 478 if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp)))) 479 return 0; 480 481 h.raw = frame; 482 /* 483 * versions 1 through 3 overflow the timestamps in y2106, since they 484 * all store the seconds in a 32-bit unsigned integer. 485 * If we create a version 4, that should have a 64-bit timestamp, 486 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit 487 * nanoseconds. 488 */ 489 switch (po->tp_version) { 490 case TPACKET_V1: 491 h.h1->tp_sec = ts.tv_sec; 492 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 493 break; 494 case TPACKET_V2: 495 h.h2->tp_sec = ts.tv_sec; 496 h.h2->tp_nsec = ts.tv_nsec; 497 break; 498 case TPACKET_V3: 499 h.h3->tp_sec = ts.tv_sec; 500 h.h3->tp_nsec = ts.tv_nsec; 501 break; 502 default: 503 WARN(1, "TPACKET version not supported.\n"); 504 BUG(); 505 } 506 507 /* one flush is safe, as both fields always lie on the same cacheline */ 508 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 509 smp_wmb(); 510 511 return ts_status; 512 } 513 514 static void *packet_lookup_frame(const struct packet_sock *po, 515 const struct packet_ring_buffer *rb, 516 unsigned int position, 517 int status) 518 { 519 unsigned int pg_vec_pos, frame_offset; 520 union tpacket_uhdr h; 521 522 pg_vec_pos = position / rb->frames_per_block; 523 frame_offset = position % rb->frames_per_block; 524 525 h.raw = rb->pg_vec[pg_vec_pos].buffer + 526 (frame_offset * rb->frame_size); 527 528 if (status != __packet_get_status(po, h.raw)) 529 return NULL; 530 531 return h.raw; 532 } 533 534 static void *packet_current_frame(struct packet_sock *po, 535 struct packet_ring_buffer *rb, 536 int status) 537 { 538 return packet_lookup_frame(po, rb, rb->head, status); 539 } 540 541 static u16 vlan_get_tci(const struct sk_buff *skb, struct net_device *dev) 542 { 543 struct vlan_hdr vhdr, *vh; 544 unsigned int header_len; 545 546 if (!dev) 547 return 0; 548 549 /* In the SOCK_DGRAM scenario, skb data starts at the network 550 * protocol, which is after the VLAN headers. The outer VLAN 551 * header is at the hard_header_len offset in non-variable 552 * length link layer headers. If it's a VLAN device, the 553 * min_header_len should be used to exclude the VLAN header 554 * size. 555 */ 556 if (dev->min_header_len == dev->hard_header_len) 557 header_len = dev->hard_header_len; 558 else if (is_vlan_dev(dev)) 559 header_len = dev->min_header_len; 560 else 561 return 0; 562 563 vh = skb_header_pointer(skb, skb_mac_offset(skb) + header_len, 564 sizeof(vhdr), &vhdr); 565 if (unlikely(!vh)) 566 return 0; 567 568 return ntohs(vh->h_vlan_TCI); 569 } 570 571 static __be16 vlan_get_protocol_dgram(const struct sk_buff *skb) 572 { 573 __be16 proto = skb->protocol; 574 575 if (unlikely(eth_type_vlan(proto))) 576 proto = __vlan_get_protocol_offset(skb, proto, 577 skb_mac_offset(skb), NULL); 578 579 return proto; 580 } 581 582 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 583 { 584 del_timer_sync(&pkc->retire_blk_timer); 585 } 586 587 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 588 struct sk_buff_head *rb_queue) 589 { 590 struct tpacket_kbdq_core *pkc; 591 592 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 593 594 spin_lock_bh(&rb_queue->lock); 595 pkc->delete_blk_timer = 1; 596 spin_unlock_bh(&rb_queue->lock); 597 598 prb_del_retire_blk_timer(pkc); 599 } 600 601 static void prb_setup_retire_blk_timer(struct packet_sock *po) 602 { 603 struct tpacket_kbdq_core *pkc; 604 605 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 606 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired, 607 0); 608 pkc->retire_blk_timer.expires = jiffies; 609 } 610 611 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 612 int blk_size_in_bytes) 613 { 614 struct net_device *dev; 615 unsigned int mbits, div; 616 struct ethtool_link_ksettings ecmd; 617 int err; 618 619 rtnl_lock(); 620 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 621 if (unlikely(!dev)) { 622 rtnl_unlock(); 623 return DEFAULT_PRB_RETIRE_TOV; 624 } 625 err = __ethtool_get_link_ksettings(dev, &ecmd); 626 rtnl_unlock(); 627 if (err) 628 return DEFAULT_PRB_RETIRE_TOV; 629 630 /* If the link speed is so slow you don't really 631 * need to worry about perf anyways 632 */ 633 if (ecmd.base.speed < SPEED_1000 || 634 ecmd.base.speed == SPEED_UNKNOWN) 635 return DEFAULT_PRB_RETIRE_TOV; 636 637 div = ecmd.base.speed / 1000; 638 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 639 640 if (div) 641 mbits /= div; 642 643 if (div) 644 return mbits + 1; 645 return mbits; 646 } 647 648 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 649 union tpacket_req_u *req_u) 650 { 651 p1->feature_req_word = req_u->req3.tp_feature_req_word; 652 } 653 654 static void init_prb_bdqc(struct packet_sock *po, 655 struct packet_ring_buffer *rb, 656 struct pgv *pg_vec, 657 union tpacket_req_u *req_u) 658 { 659 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 660 struct tpacket_block_desc *pbd; 661 662 memset(p1, 0x0, sizeof(*p1)); 663 664 p1->knxt_seq_num = 1; 665 p1->pkbdq = pg_vec; 666 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 667 p1->pkblk_start = pg_vec[0].buffer; 668 p1->kblk_size = req_u->req3.tp_block_size; 669 p1->knum_blocks = req_u->req3.tp_block_nr; 670 p1->hdrlen = po->tp_hdrlen; 671 p1->version = po->tp_version; 672 p1->last_kactive_blk_num = 0; 673 po->stats.stats3.tp_freeze_q_cnt = 0; 674 if (req_u->req3.tp_retire_blk_tov) 675 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 676 else 677 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 678 req_u->req3.tp_block_size); 679 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 680 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 681 rwlock_init(&p1->blk_fill_in_prog_lock); 682 683 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 684 prb_init_ft_ops(p1, req_u); 685 prb_setup_retire_blk_timer(po); 686 prb_open_block(p1, pbd); 687 } 688 689 /* Do NOT update the last_blk_num first. 690 * Assumes sk_buff_head lock is held. 691 */ 692 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 693 { 694 mod_timer(&pkc->retire_blk_timer, 695 jiffies + pkc->tov_in_jiffies); 696 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 697 } 698 699 /* 700 * Timer logic: 701 * 1) We refresh the timer only when we open a block. 702 * By doing this we don't waste cycles refreshing the timer 703 * on packet-by-packet basis. 704 * 705 * With a 1MB block-size, on a 1Gbps line, it will take 706 * i) ~8 ms to fill a block + ii) memcpy etc. 707 * In this cut we are not accounting for the memcpy time. 708 * 709 * So, if the user sets the 'tmo' to 10ms then the timer 710 * will never fire while the block is still getting filled 711 * (which is what we want). However, the user could choose 712 * to close a block early and that's fine. 713 * 714 * But when the timer does fire, we check whether or not to refresh it. 715 * Since the tmo granularity is in msecs, it is not too expensive 716 * to refresh the timer, lets say every '8' msecs. 717 * Either the user can set the 'tmo' or we can derive it based on 718 * a) line-speed and b) block-size. 719 * prb_calc_retire_blk_tmo() calculates the tmo. 720 * 721 */ 722 static void prb_retire_rx_blk_timer_expired(struct timer_list *t) 723 { 724 struct packet_sock *po = 725 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer); 726 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 727 unsigned int frozen; 728 struct tpacket_block_desc *pbd; 729 730 spin_lock(&po->sk.sk_receive_queue.lock); 731 732 frozen = prb_queue_frozen(pkc); 733 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 734 735 if (unlikely(pkc->delete_blk_timer)) 736 goto out; 737 738 /* We only need to plug the race when the block is partially filled. 739 * tpacket_rcv: 740 * lock(); increment BLOCK_NUM_PKTS; unlock() 741 * copy_bits() is in progress ... 742 * timer fires on other cpu: 743 * we can't retire the current block because copy_bits 744 * is in progress. 745 * 746 */ 747 if (BLOCK_NUM_PKTS(pbd)) { 748 /* Waiting for skb_copy_bits to finish... */ 749 write_lock(&pkc->blk_fill_in_prog_lock); 750 write_unlock(&pkc->blk_fill_in_prog_lock); 751 } 752 753 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 754 if (!frozen) { 755 if (!BLOCK_NUM_PKTS(pbd)) { 756 /* An empty block. Just refresh the timer. */ 757 goto refresh_timer; 758 } 759 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 760 if (!prb_dispatch_next_block(pkc, po)) 761 goto refresh_timer; 762 else 763 goto out; 764 } else { 765 /* Case 1. Queue was frozen because user-space was 766 * lagging behind. 767 */ 768 if (prb_curr_blk_in_use(pbd)) { 769 /* 770 * Ok, user-space is still behind. 771 * So just refresh the timer. 772 */ 773 goto refresh_timer; 774 } else { 775 /* Case 2. queue was frozen,user-space caught up, 776 * now the link went idle && the timer fired. 777 * We don't have a block to close.So we open this 778 * block and restart the timer. 779 * opening a block thaws the queue,restarts timer 780 * Thawing/timer-refresh is a side effect. 781 */ 782 prb_open_block(pkc, pbd); 783 goto out; 784 } 785 } 786 } 787 788 refresh_timer: 789 _prb_refresh_rx_retire_blk_timer(pkc); 790 791 out: 792 spin_unlock(&po->sk.sk_receive_queue.lock); 793 } 794 795 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 796 struct tpacket_block_desc *pbd1, __u32 status) 797 { 798 /* Flush everything minus the block header */ 799 800 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 801 u8 *start, *end; 802 803 start = (u8 *)pbd1; 804 805 /* Skip the block header(we know header WILL fit in 4K) */ 806 start += PAGE_SIZE; 807 808 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 809 for (; start < end; start += PAGE_SIZE) 810 flush_dcache_page(pgv_to_page(start)); 811 812 smp_wmb(); 813 #endif 814 815 /* Now update the block status. */ 816 817 BLOCK_STATUS(pbd1) = status; 818 819 /* Flush the block header */ 820 821 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 822 start = (u8 *)pbd1; 823 flush_dcache_page(pgv_to_page(start)); 824 825 smp_wmb(); 826 #endif 827 } 828 829 /* 830 * Side effect: 831 * 832 * 1) flush the block 833 * 2) Increment active_blk_num 834 * 835 * Note:We DONT refresh the timer on purpose. 836 * Because almost always the next block will be opened. 837 */ 838 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 839 struct tpacket_block_desc *pbd1, 840 struct packet_sock *po, unsigned int stat) 841 { 842 __u32 status = TP_STATUS_USER | stat; 843 844 struct tpacket3_hdr *last_pkt; 845 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 846 struct sock *sk = &po->sk; 847 848 if (atomic_read(&po->tp_drops)) 849 status |= TP_STATUS_LOSING; 850 851 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 852 last_pkt->tp_next_offset = 0; 853 854 /* Get the ts of the last pkt */ 855 if (BLOCK_NUM_PKTS(pbd1)) { 856 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 857 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 858 } else { 859 /* Ok, we tmo'd - so get the current time. 860 * 861 * It shouldn't really happen as we don't close empty 862 * blocks. See prb_retire_rx_blk_timer_expired(). 863 */ 864 struct timespec64 ts; 865 ktime_get_real_ts64(&ts); 866 h1->ts_last_pkt.ts_sec = ts.tv_sec; 867 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 868 } 869 870 smp_wmb(); 871 872 /* Flush the block */ 873 prb_flush_block(pkc1, pbd1, status); 874 875 sk->sk_data_ready(sk); 876 877 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 878 } 879 880 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 881 { 882 pkc->reset_pending_on_curr_blk = 0; 883 } 884 885 /* 886 * Side effect of opening a block: 887 * 888 * 1) prb_queue is thawed. 889 * 2) retire_blk_timer is refreshed. 890 * 891 */ 892 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 893 struct tpacket_block_desc *pbd1) 894 { 895 struct timespec64 ts; 896 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 897 898 smp_rmb(); 899 900 /* We could have just memset this but we will lose the 901 * flexibility of making the priv area sticky 902 */ 903 904 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 905 BLOCK_NUM_PKTS(pbd1) = 0; 906 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 907 908 ktime_get_real_ts64(&ts); 909 910 h1->ts_first_pkt.ts_sec = ts.tv_sec; 911 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 912 913 pkc1->pkblk_start = (char *)pbd1; 914 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 915 916 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 917 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 918 919 pbd1->version = pkc1->version; 920 pkc1->prev = pkc1->nxt_offset; 921 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 922 923 prb_thaw_queue(pkc1); 924 _prb_refresh_rx_retire_blk_timer(pkc1); 925 926 smp_wmb(); 927 } 928 929 /* 930 * Queue freeze logic: 931 * 1) Assume tp_block_nr = 8 blocks. 932 * 2) At time 't0', user opens Rx ring. 933 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 934 * 4) user-space is either sleeping or processing block '0'. 935 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 936 * it will close block-7,loop around and try to fill block '0'. 937 * call-flow: 938 * __packet_lookup_frame_in_block 939 * prb_retire_current_block() 940 * prb_dispatch_next_block() 941 * |->(BLOCK_STATUS == USER) evaluates to true 942 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 943 * 6) Now there are two cases: 944 * 6.1) Link goes idle right after the queue is frozen. 945 * But remember, the last open_block() refreshed the timer. 946 * When this timer expires,it will refresh itself so that we can 947 * re-open block-0 in near future. 948 * 6.2) Link is busy and keeps on receiving packets. This is a simple 949 * case and __packet_lookup_frame_in_block will check if block-0 950 * is free and can now be re-used. 951 */ 952 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 953 struct packet_sock *po) 954 { 955 pkc->reset_pending_on_curr_blk = 1; 956 po->stats.stats3.tp_freeze_q_cnt++; 957 } 958 959 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 960 961 /* 962 * If the next block is free then we will dispatch it 963 * and return a good offset. 964 * Else, we will freeze the queue. 965 * So, caller must check the return value. 966 */ 967 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 968 struct packet_sock *po) 969 { 970 struct tpacket_block_desc *pbd; 971 972 smp_rmb(); 973 974 /* 1. Get current block num */ 975 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 976 977 /* 2. If this block is currently in_use then freeze the queue */ 978 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 979 prb_freeze_queue(pkc, po); 980 return NULL; 981 } 982 983 /* 984 * 3. 985 * open this block and return the offset where the first packet 986 * needs to get stored. 987 */ 988 prb_open_block(pkc, pbd); 989 return (void *)pkc->nxt_offset; 990 } 991 992 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 993 struct packet_sock *po, unsigned int status) 994 { 995 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 996 997 /* retire/close the current block */ 998 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 999 /* 1000 * Plug the case where copy_bits() is in progress on 1001 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 1002 * have space to copy the pkt in the current block and 1003 * called prb_retire_current_block() 1004 * 1005 * We don't need to worry about the TMO case because 1006 * the timer-handler already handled this case. 1007 */ 1008 if (!(status & TP_STATUS_BLK_TMO)) { 1009 /* Waiting for skb_copy_bits to finish... */ 1010 write_lock(&pkc->blk_fill_in_prog_lock); 1011 write_unlock(&pkc->blk_fill_in_prog_lock); 1012 } 1013 prb_close_block(pkc, pbd, po, status); 1014 return; 1015 } 1016 } 1017 1018 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) 1019 { 1020 return TP_STATUS_USER & BLOCK_STATUS(pbd); 1021 } 1022 1023 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 1024 { 1025 return pkc->reset_pending_on_curr_blk; 1026 } 1027 1028 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 1029 __releases(&pkc->blk_fill_in_prog_lock) 1030 { 1031 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1032 1033 read_unlock(&pkc->blk_fill_in_prog_lock); 1034 } 1035 1036 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 1037 struct tpacket3_hdr *ppd) 1038 { 1039 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 1040 } 1041 1042 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 1043 struct tpacket3_hdr *ppd) 1044 { 1045 ppd->hv1.tp_rxhash = 0; 1046 } 1047 1048 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 1049 struct tpacket3_hdr *ppd) 1050 { 1051 struct packet_sock *po = container_of(pkc, struct packet_sock, rx_ring.prb_bdqc); 1052 1053 if (skb_vlan_tag_present(pkc->skb)) { 1054 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1055 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1056 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1057 } else if (unlikely(po->sk.sk_type == SOCK_DGRAM && eth_type_vlan(pkc->skb->protocol))) { 1058 ppd->hv1.tp_vlan_tci = vlan_get_tci(pkc->skb, pkc->skb->dev); 1059 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->protocol); 1060 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1061 } else { 1062 ppd->hv1.tp_vlan_tci = 0; 1063 ppd->hv1.tp_vlan_tpid = 0; 1064 ppd->tp_status = TP_STATUS_AVAILABLE; 1065 } 1066 } 1067 1068 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1069 struct tpacket3_hdr *ppd) 1070 { 1071 ppd->hv1.tp_padding = 0; 1072 prb_fill_vlan_info(pkc, ppd); 1073 1074 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1075 prb_fill_rxhash(pkc, ppd); 1076 else 1077 prb_clear_rxhash(pkc, ppd); 1078 } 1079 1080 static void prb_fill_curr_block(char *curr, 1081 struct tpacket_kbdq_core *pkc, 1082 struct tpacket_block_desc *pbd, 1083 unsigned int len) 1084 __acquires(&pkc->blk_fill_in_prog_lock) 1085 { 1086 struct tpacket3_hdr *ppd; 1087 1088 ppd = (struct tpacket3_hdr *)curr; 1089 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1090 pkc->prev = curr; 1091 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1092 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1093 BLOCK_NUM_PKTS(pbd) += 1; 1094 read_lock(&pkc->blk_fill_in_prog_lock); 1095 prb_run_all_ft_ops(pkc, ppd); 1096 } 1097 1098 /* Assumes caller has the sk->rx_queue.lock */ 1099 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1100 struct sk_buff *skb, 1101 unsigned int len 1102 ) 1103 { 1104 struct tpacket_kbdq_core *pkc; 1105 struct tpacket_block_desc *pbd; 1106 char *curr, *end; 1107 1108 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1109 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1110 1111 /* Queue is frozen when user space is lagging behind */ 1112 if (prb_queue_frozen(pkc)) { 1113 /* 1114 * Check if that last block which caused the queue to freeze, 1115 * is still in_use by user-space. 1116 */ 1117 if (prb_curr_blk_in_use(pbd)) { 1118 /* Can't record this packet */ 1119 return NULL; 1120 } else { 1121 /* 1122 * Ok, the block was released by user-space. 1123 * Now let's open that block. 1124 * opening a block also thaws the queue. 1125 * Thawing is a side effect. 1126 */ 1127 prb_open_block(pkc, pbd); 1128 } 1129 } 1130 1131 smp_mb(); 1132 curr = pkc->nxt_offset; 1133 pkc->skb = skb; 1134 end = (char *)pbd + pkc->kblk_size; 1135 1136 /* first try the current block */ 1137 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1138 prb_fill_curr_block(curr, pkc, pbd, len); 1139 return (void *)curr; 1140 } 1141 1142 /* Ok, close the current block */ 1143 prb_retire_current_block(pkc, po, 0); 1144 1145 /* Now, try to dispatch the next block */ 1146 curr = (char *)prb_dispatch_next_block(pkc, po); 1147 if (curr) { 1148 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1149 prb_fill_curr_block(curr, pkc, pbd, len); 1150 return (void *)curr; 1151 } 1152 1153 /* 1154 * No free blocks are available.user_space hasn't caught up yet. 1155 * Queue was just frozen and now this packet will get dropped. 1156 */ 1157 return NULL; 1158 } 1159 1160 static void *packet_current_rx_frame(struct packet_sock *po, 1161 struct sk_buff *skb, 1162 int status, unsigned int len) 1163 { 1164 char *curr = NULL; 1165 switch (po->tp_version) { 1166 case TPACKET_V1: 1167 case TPACKET_V2: 1168 curr = packet_lookup_frame(po, &po->rx_ring, 1169 po->rx_ring.head, status); 1170 return curr; 1171 case TPACKET_V3: 1172 return __packet_lookup_frame_in_block(po, skb, len); 1173 default: 1174 WARN(1, "TPACKET version not supported\n"); 1175 BUG(); 1176 return NULL; 1177 } 1178 } 1179 1180 static void *prb_lookup_block(const struct packet_sock *po, 1181 const struct packet_ring_buffer *rb, 1182 unsigned int idx, 1183 int status) 1184 { 1185 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1186 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1187 1188 if (status != BLOCK_STATUS(pbd)) 1189 return NULL; 1190 return pbd; 1191 } 1192 1193 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1194 { 1195 unsigned int prev; 1196 if (rb->prb_bdqc.kactive_blk_num) 1197 prev = rb->prb_bdqc.kactive_blk_num-1; 1198 else 1199 prev = rb->prb_bdqc.knum_blocks-1; 1200 return prev; 1201 } 1202 1203 /* Assumes caller has held the rx_queue.lock */ 1204 static void *__prb_previous_block(struct packet_sock *po, 1205 struct packet_ring_buffer *rb, 1206 int status) 1207 { 1208 unsigned int previous = prb_previous_blk_num(rb); 1209 return prb_lookup_block(po, rb, previous, status); 1210 } 1211 1212 static void *packet_previous_rx_frame(struct packet_sock *po, 1213 struct packet_ring_buffer *rb, 1214 int status) 1215 { 1216 if (po->tp_version <= TPACKET_V2) 1217 return packet_previous_frame(po, rb, status); 1218 1219 return __prb_previous_block(po, rb, status); 1220 } 1221 1222 static void packet_increment_rx_head(struct packet_sock *po, 1223 struct packet_ring_buffer *rb) 1224 { 1225 switch (po->tp_version) { 1226 case TPACKET_V1: 1227 case TPACKET_V2: 1228 return packet_increment_head(rb); 1229 case TPACKET_V3: 1230 default: 1231 WARN(1, "TPACKET version not supported.\n"); 1232 BUG(); 1233 return; 1234 } 1235 } 1236 1237 static void *packet_previous_frame(struct packet_sock *po, 1238 struct packet_ring_buffer *rb, 1239 int status) 1240 { 1241 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1242 return packet_lookup_frame(po, rb, previous, status); 1243 } 1244 1245 static void packet_increment_head(struct packet_ring_buffer *buff) 1246 { 1247 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1248 } 1249 1250 static void packet_inc_pending(struct packet_ring_buffer *rb) 1251 { 1252 this_cpu_inc(*rb->pending_refcnt); 1253 } 1254 1255 static void packet_dec_pending(struct packet_ring_buffer *rb) 1256 { 1257 this_cpu_dec(*rb->pending_refcnt); 1258 } 1259 1260 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1261 { 1262 unsigned int refcnt = 0; 1263 int cpu; 1264 1265 /* We don't use pending refcount in rx_ring. */ 1266 if (rb->pending_refcnt == NULL) 1267 return 0; 1268 1269 for_each_possible_cpu(cpu) 1270 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1271 1272 return refcnt; 1273 } 1274 1275 static int packet_alloc_pending(struct packet_sock *po) 1276 { 1277 po->rx_ring.pending_refcnt = NULL; 1278 1279 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1280 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1281 return -ENOBUFS; 1282 1283 return 0; 1284 } 1285 1286 static void packet_free_pending(struct packet_sock *po) 1287 { 1288 free_percpu(po->tx_ring.pending_refcnt); 1289 } 1290 1291 #define ROOM_POW_OFF 2 1292 #define ROOM_NONE 0x0 1293 #define ROOM_LOW 0x1 1294 #define ROOM_NORMAL 0x2 1295 1296 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) 1297 { 1298 int idx, len; 1299 1300 len = READ_ONCE(po->rx_ring.frame_max) + 1; 1301 idx = READ_ONCE(po->rx_ring.head); 1302 if (pow_off) 1303 idx += len >> pow_off; 1304 if (idx >= len) 1305 idx -= len; 1306 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1307 } 1308 1309 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) 1310 { 1311 int idx, len; 1312 1313 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); 1314 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); 1315 if (pow_off) 1316 idx += len >> pow_off; 1317 if (idx >= len) 1318 idx -= len; 1319 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1320 } 1321 1322 static int __packet_rcv_has_room(const struct packet_sock *po, 1323 const struct sk_buff *skb) 1324 { 1325 const struct sock *sk = &po->sk; 1326 int ret = ROOM_NONE; 1327 1328 if (po->prot_hook.func != tpacket_rcv) { 1329 int rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1330 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1331 - (skb ? skb->truesize : 0); 1332 1333 if (avail > (rcvbuf >> ROOM_POW_OFF)) 1334 return ROOM_NORMAL; 1335 else if (avail > 0) 1336 return ROOM_LOW; 1337 else 1338 return ROOM_NONE; 1339 } 1340 1341 if (po->tp_version == TPACKET_V3) { 1342 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1343 ret = ROOM_NORMAL; 1344 else if (__tpacket_v3_has_room(po, 0)) 1345 ret = ROOM_LOW; 1346 } else { 1347 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1348 ret = ROOM_NORMAL; 1349 else if (__tpacket_has_room(po, 0)) 1350 ret = ROOM_LOW; 1351 } 1352 1353 return ret; 1354 } 1355 1356 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1357 { 1358 bool pressure; 1359 int ret; 1360 1361 ret = __packet_rcv_has_room(po, skb); 1362 pressure = ret != ROOM_NORMAL; 1363 1364 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure) 1365 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure); 1366 1367 return ret; 1368 } 1369 1370 static void packet_rcv_try_clear_pressure(struct packet_sock *po) 1371 { 1372 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) && 1373 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 1374 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false); 1375 } 1376 1377 static void packet_sock_destruct(struct sock *sk) 1378 { 1379 skb_queue_purge(&sk->sk_error_queue); 1380 1381 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1382 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1383 1384 if (!sock_flag(sk, SOCK_DEAD)) { 1385 pr_err("Attempt to release alive packet socket: %p\n", sk); 1386 return; 1387 } 1388 } 1389 1390 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1391 { 1392 u32 *history = po->rollover->history; 1393 u32 victim, rxhash; 1394 int i, count = 0; 1395 1396 rxhash = skb_get_hash(skb); 1397 for (i = 0; i < ROLLOVER_HLEN; i++) 1398 if (READ_ONCE(history[i]) == rxhash) 1399 count++; 1400 1401 victim = get_random_u32_below(ROLLOVER_HLEN); 1402 1403 /* Avoid dirtying the cache line if possible */ 1404 if (READ_ONCE(history[victim]) != rxhash) 1405 WRITE_ONCE(history[victim], rxhash); 1406 1407 return count > (ROLLOVER_HLEN >> 1); 1408 } 1409 1410 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1411 struct sk_buff *skb, 1412 unsigned int num) 1413 { 1414 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1415 } 1416 1417 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1418 struct sk_buff *skb, 1419 unsigned int num) 1420 { 1421 unsigned int val = atomic_inc_return(&f->rr_cur); 1422 1423 return val % num; 1424 } 1425 1426 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1427 struct sk_buff *skb, 1428 unsigned int num) 1429 { 1430 return smp_processor_id() % num; 1431 } 1432 1433 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1434 struct sk_buff *skb, 1435 unsigned int num) 1436 { 1437 return get_random_u32_below(num); 1438 } 1439 1440 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1441 struct sk_buff *skb, 1442 unsigned int idx, bool try_self, 1443 unsigned int num) 1444 { 1445 struct packet_sock *po, *po_next, *po_skip = NULL; 1446 unsigned int i, j, room = ROOM_NONE; 1447 1448 po = pkt_sk(rcu_dereference(f->arr[idx])); 1449 1450 if (try_self) { 1451 room = packet_rcv_has_room(po, skb); 1452 if (room == ROOM_NORMAL || 1453 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1454 return idx; 1455 po_skip = po; 1456 } 1457 1458 i = j = min_t(int, po->rollover->sock, num - 1); 1459 do { 1460 po_next = pkt_sk(rcu_dereference(f->arr[i])); 1461 if (po_next != po_skip && 1462 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) && 1463 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1464 if (i != j) 1465 po->rollover->sock = i; 1466 atomic_long_inc(&po->rollover->num); 1467 if (room == ROOM_LOW) 1468 atomic_long_inc(&po->rollover->num_huge); 1469 return i; 1470 } 1471 1472 if (++i == num) 1473 i = 0; 1474 } while (i != j); 1475 1476 atomic_long_inc(&po->rollover->num_failed); 1477 return idx; 1478 } 1479 1480 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1481 struct sk_buff *skb, 1482 unsigned int num) 1483 { 1484 return skb_get_queue_mapping(skb) % num; 1485 } 1486 1487 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1488 struct sk_buff *skb, 1489 unsigned int num) 1490 { 1491 struct bpf_prog *prog; 1492 unsigned int ret = 0; 1493 1494 rcu_read_lock(); 1495 prog = rcu_dereference(f->bpf_prog); 1496 if (prog) 1497 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1498 rcu_read_unlock(); 1499 1500 return ret; 1501 } 1502 1503 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1504 { 1505 return f->flags & (flag >> 8); 1506 } 1507 1508 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1509 struct packet_type *pt, struct net_device *orig_dev) 1510 { 1511 struct packet_fanout *f = pt->af_packet_priv; 1512 unsigned int num = READ_ONCE(f->num_members); 1513 struct net *net = read_pnet(&f->net); 1514 struct packet_sock *po; 1515 unsigned int idx; 1516 1517 if (!net_eq(dev_net(dev), net) || !num) { 1518 kfree_skb(skb); 1519 return 0; 1520 } 1521 1522 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1523 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1524 if (!skb) 1525 return 0; 1526 } 1527 switch (f->type) { 1528 case PACKET_FANOUT_HASH: 1529 default: 1530 idx = fanout_demux_hash(f, skb, num); 1531 break; 1532 case PACKET_FANOUT_LB: 1533 idx = fanout_demux_lb(f, skb, num); 1534 break; 1535 case PACKET_FANOUT_CPU: 1536 idx = fanout_demux_cpu(f, skb, num); 1537 break; 1538 case PACKET_FANOUT_RND: 1539 idx = fanout_demux_rnd(f, skb, num); 1540 break; 1541 case PACKET_FANOUT_QM: 1542 idx = fanout_demux_qm(f, skb, num); 1543 break; 1544 case PACKET_FANOUT_ROLLOVER: 1545 idx = fanout_demux_rollover(f, skb, 0, false, num); 1546 break; 1547 case PACKET_FANOUT_CBPF: 1548 case PACKET_FANOUT_EBPF: 1549 idx = fanout_demux_bpf(f, skb, num); 1550 break; 1551 } 1552 1553 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1554 idx = fanout_demux_rollover(f, skb, idx, true, num); 1555 1556 po = pkt_sk(rcu_dereference(f->arr[idx])); 1557 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1558 } 1559 1560 DEFINE_MUTEX(fanout_mutex); 1561 EXPORT_SYMBOL_GPL(fanout_mutex); 1562 static LIST_HEAD(fanout_list); 1563 static u16 fanout_next_id; 1564 1565 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1566 { 1567 struct packet_fanout *f = po->fanout; 1568 1569 spin_lock(&f->lock); 1570 rcu_assign_pointer(f->arr[f->num_members], sk); 1571 smp_wmb(); 1572 f->num_members++; 1573 if (f->num_members == 1) 1574 dev_add_pack(&f->prot_hook); 1575 spin_unlock(&f->lock); 1576 } 1577 1578 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1579 { 1580 struct packet_fanout *f = po->fanout; 1581 int i; 1582 1583 spin_lock(&f->lock); 1584 for (i = 0; i < f->num_members; i++) { 1585 if (rcu_dereference_protected(f->arr[i], 1586 lockdep_is_held(&f->lock)) == sk) 1587 break; 1588 } 1589 BUG_ON(i >= f->num_members); 1590 rcu_assign_pointer(f->arr[i], 1591 rcu_dereference_protected(f->arr[f->num_members - 1], 1592 lockdep_is_held(&f->lock))); 1593 f->num_members--; 1594 if (f->num_members == 0) 1595 __dev_remove_pack(&f->prot_hook); 1596 spin_unlock(&f->lock); 1597 } 1598 1599 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1600 { 1601 if (sk->sk_family != PF_PACKET) 1602 return false; 1603 1604 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1605 } 1606 1607 static void fanout_init_data(struct packet_fanout *f) 1608 { 1609 switch (f->type) { 1610 case PACKET_FANOUT_LB: 1611 atomic_set(&f->rr_cur, 0); 1612 break; 1613 case PACKET_FANOUT_CBPF: 1614 case PACKET_FANOUT_EBPF: 1615 RCU_INIT_POINTER(f->bpf_prog, NULL); 1616 break; 1617 } 1618 } 1619 1620 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1621 { 1622 struct bpf_prog *old; 1623 1624 spin_lock(&f->lock); 1625 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1626 rcu_assign_pointer(f->bpf_prog, new); 1627 spin_unlock(&f->lock); 1628 1629 if (old) { 1630 synchronize_net(); 1631 bpf_prog_destroy(old); 1632 } 1633 } 1634 1635 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, 1636 unsigned int len) 1637 { 1638 struct bpf_prog *new; 1639 struct sock_fprog fprog; 1640 int ret; 1641 1642 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1643 return -EPERM; 1644 1645 ret = copy_bpf_fprog_from_user(&fprog, data, len); 1646 if (ret) 1647 return ret; 1648 1649 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1650 if (ret) 1651 return ret; 1652 1653 __fanout_set_data_bpf(po->fanout, new); 1654 return 0; 1655 } 1656 1657 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, 1658 unsigned int len) 1659 { 1660 struct bpf_prog *new; 1661 u32 fd; 1662 1663 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1664 return -EPERM; 1665 if (len != sizeof(fd)) 1666 return -EINVAL; 1667 if (copy_from_sockptr(&fd, data, len)) 1668 return -EFAULT; 1669 1670 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1671 if (IS_ERR(new)) 1672 return PTR_ERR(new); 1673 1674 __fanout_set_data_bpf(po->fanout, new); 1675 return 0; 1676 } 1677 1678 static int fanout_set_data(struct packet_sock *po, sockptr_t data, 1679 unsigned int len) 1680 { 1681 switch (po->fanout->type) { 1682 case PACKET_FANOUT_CBPF: 1683 return fanout_set_data_cbpf(po, data, len); 1684 case PACKET_FANOUT_EBPF: 1685 return fanout_set_data_ebpf(po, data, len); 1686 default: 1687 return -EINVAL; 1688 } 1689 } 1690 1691 static void fanout_release_data(struct packet_fanout *f) 1692 { 1693 switch (f->type) { 1694 case PACKET_FANOUT_CBPF: 1695 case PACKET_FANOUT_EBPF: 1696 __fanout_set_data_bpf(f, NULL); 1697 } 1698 } 1699 1700 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1701 { 1702 struct packet_fanout *f; 1703 1704 list_for_each_entry(f, &fanout_list, list) { 1705 if (f->id == candidate_id && 1706 read_pnet(&f->net) == sock_net(sk)) { 1707 return false; 1708 } 1709 } 1710 return true; 1711 } 1712 1713 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1714 { 1715 u16 id = fanout_next_id; 1716 1717 do { 1718 if (__fanout_id_is_free(sk, id)) { 1719 *new_id = id; 1720 fanout_next_id = id + 1; 1721 return true; 1722 } 1723 1724 id++; 1725 } while (id != fanout_next_id); 1726 1727 return false; 1728 } 1729 1730 static int fanout_add(struct sock *sk, struct fanout_args *args) 1731 { 1732 struct packet_rollover *rollover = NULL; 1733 struct packet_sock *po = pkt_sk(sk); 1734 u16 type_flags = args->type_flags; 1735 struct packet_fanout *f, *match; 1736 u8 type = type_flags & 0xff; 1737 u8 flags = type_flags >> 8; 1738 u16 id = args->id; 1739 int err; 1740 1741 switch (type) { 1742 case PACKET_FANOUT_ROLLOVER: 1743 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1744 return -EINVAL; 1745 break; 1746 case PACKET_FANOUT_HASH: 1747 case PACKET_FANOUT_LB: 1748 case PACKET_FANOUT_CPU: 1749 case PACKET_FANOUT_RND: 1750 case PACKET_FANOUT_QM: 1751 case PACKET_FANOUT_CBPF: 1752 case PACKET_FANOUT_EBPF: 1753 break; 1754 default: 1755 return -EINVAL; 1756 } 1757 1758 mutex_lock(&fanout_mutex); 1759 1760 err = -EALREADY; 1761 if (po->fanout) 1762 goto out; 1763 1764 if (type == PACKET_FANOUT_ROLLOVER || 1765 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1766 err = -ENOMEM; 1767 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); 1768 if (!rollover) 1769 goto out; 1770 atomic_long_set(&rollover->num, 0); 1771 atomic_long_set(&rollover->num_huge, 0); 1772 atomic_long_set(&rollover->num_failed, 0); 1773 } 1774 1775 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1776 if (id != 0) { 1777 err = -EINVAL; 1778 goto out; 1779 } 1780 if (!fanout_find_new_id(sk, &id)) { 1781 err = -ENOMEM; 1782 goto out; 1783 } 1784 /* ephemeral flag for the first socket in the group: drop it */ 1785 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1786 } 1787 1788 match = NULL; 1789 list_for_each_entry(f, &fanout_list, list) { 1790 if (f->id == id && 1791 read_pnet(&f->net) == sock_net(sk)) { 1792 match = f; 1793 break; 1794 } 1795 } 1796 err = -EINVAL; 1797 if (match) { 1798 if (match->flags != flags) 1799 goto out; 1800 if (args->max_num_members && 1801 args->max_num_members != match->max_num_members) 1802 goto out; 1803 } else { 1804 if (args->max_num_members > PACKET_FANOUT_MAX) 1805 goto out; 1806 if (!args->max_num_members) 1807 /* legacy PACKET_FANOUT_MAX */ 1808 args->max_num_members = 256; 1809 err = -ENOMEM; 1810 match = kvzalloc(struct_size(match, arr, args->max_num_members), 1811 GFP_KERNEL); 1812 if (!match) 1813 goto out; 1814 write_pnet(&match->net, sock_net(sk)); 1815 match->id = id; 1816 match->type = type; 1817 match->flags = flags; 1818 INIT_LIST_HEAD(&match->list); 1819 spin_lock_init(&match->lock); 1820 refcount_set(&match->sk_ref, 0); 1821 fanout_init_data(match); 1822 match->prot_hook.type = po->prot_hook.type; 1823 match->prot_hook.dev = po->prot_hook.dev; 1824 match->prot_hook.func = packet_rcv_fanout; 1825 match->prot_hook.af_packet_priv = match; 1826 match->prot_hook.af_packet_net = read_pnet(&match->net); 1827 match->prot_hook.id_match = match_fanout_group; 1828 match->max_num_members = args->max_num_members; 1829 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; 1830 list_add(&match->list, &fanout_list); 1831 } 1832 err = -EINVAL; 1833 1834 spin_lock(&po->bind_lock); 1835 if (packet_sock_flag(po, PACKET_SOCK_RUNNING) && 1836 match->type == type && 1837 match->prot_hook.type == po->prot_hook.type && 1838 match->prot_hook.dev == po->prot_hook.dev) { 1839 err = -ENOSPC; 1840 if (refcount_read(&match->sk_ref) < match->max_num_members) { 1841 __dev_remove_pack(&po->prot_hook); 1842 1843 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1844 WRITE_ONCE(po->fanout, match); 1845 1846 po->rollover = rollover; 1847 rollover = NULL; 1848 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1849 __fanout_link(sk, po); 1850 err = 0; 1851 } 1852 } 1853 spin_unlock(&po->bind_lock); 1854 1855 if (err && !refcount_read(&match->sk_ref)) { 1856 list_del(&match->list); 1857 kvfree(match); 1858 } 1859 1860 out: 1861 kfree(rollover); 1862 mutex_unlock(&fanout_mutex); 1863 return err; 1864 } 1865 1866 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1867 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1868 * It is the responsibility of the caller to call fanout_release_data() and 1869 * free the returned packet_fanout (after synchronize_net()) 1870 */ 1871 static struct packet_fanout *fanout_release(struct sock *sk) 1872 { 1873 struct packet_sock *po = pkt_sk(sk); 1874 struct packet_fanout *f; 1875 1876 mutex_lock(&fanout_mutex); 1877 f = po->fanout; 1878 if (f) { 1879 po->fanout = NULL; 1880 1881 if (refcount_dec_and_test(&f->sk_ref)) 1882 list_del(&f->list); 1883 else 1884 f = NULL; 1885 } 1886 mutex_unlock(&fanout_mutex); 1887 1888 return f; 1889 } 1890 1891 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1892 struct sk_buff *skb) 1893 { 1894 /* Earlier code assumed this would be a VLAN pkt, double-check 1895 * this now that we have the actual packet in hand. We can only 1896 * do this check on Ethernet devices. 1897 */ 1898 if (unlikely(dev->type != ARPHRD_ETHER)) 1899 return false; 1900 1901 skb_reset_mac_header(skb); 1902 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1903 } 1904 1905 static const struct proto_ops packet_ops; 1906 1907 static const struct proto_ops packet_ops_spkt; 1908 1909 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1910 struct packet_type *pt, struct net_device *orig_dev) 1911 { 1912 struct sock *sk; 1913 struct sockaddr_pkt *spkt; 1914 1915 /* 1916 * When we registered the protocol we saved the socket in the data 1917 * field for just this event. 1918 */ 1919 1920 sk = pt->af_packet_priv; 1921 1922 /* 1923 * Yank back the headers [hope the device set this 1924 * right or kerboom...] 1925 * 1926 * Incoming packets have ll header pulled, 1927 * push it back. 1928 * 1929 * For outgoing ones skb->data == skb_mac_header(skb) 1930 * so that this procedure is noop. 1931 */ 1932 1933 if (skb->pkt_type == PACKET_LOOPBACK) 1934 goto out; 1935 1936 if (!net_eq(dev_net(dev), sock_net(sk))) 1937 goto out; 1938 1939 skb = skb_share_check(skb, GFP_ATOMIC); 1940 if (skb == NULL) 1941 goto oom; 1942 1943 /* drop any routing info */ 1944 skb_dst_drop(skb); 1945 1946 /* drop conntrack reference */ 1947 nf_reset_ct(skb); 1948 1949 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1950 1951 skb_push(skb, skb->data - skb_mac_header(skb)); 1952 1953 /* 1954 * The SOCK_PACKET socket receives _all_ frames. 1955 */ 1956 1957 spkt->spkt_family = dev->type; 1958 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1959 spkt->spkt_protocol = skb->protocol; 1960 1961 /* 1962 * Charge the memory to the socket. This is done specifically 1963 * to prevent sockets using all the memory up. 1964 */ 1965 1966 if (sock_queue_rcv_skb(sk, skb) == 0) 1967 return 0; 1968 1969 out: 1970 kfree_skb(skb); 1971 oom: 1972 return 0; 1973 } 1974 1975 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1976 { 1977 int depth; 1978 1979 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1980 sock->type == SOCK_RAW) { 1981 skb_reset_mac_header(skb); 1982 skb->protocol = dev_parse_header_protocol(skb); 1983 } 1984 1985 /* Move network header to the right position for VLAN tagged packets */ 1986 if (likely(skb->dev->type == ARPHRD_ETHER) && 1987 eth_type_vlan(skb->protocol) && 1988 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 1989 skb_set_network_header(skb, depth); 1990 1991 skb_probe_transport_header(skb); 1992 } 1993 1994 /* 1995 * Output a raw packet to a device layer. This bypasses all the other 1996 * protocol layers and you must therefore supply it with a complete frame 1997 */ 1998 1999 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 2000 size_t len) 2001 { 2002 struct sock *sk = sock->sk; 2003 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 2004 struct sk_buff *skb = NULL; 2005 struct net_device *dev; 2006 struct sockcm_cookie sockc; 2007 __be16 proto = 0; 2008 int err; 2009 int extra_len = 0; 2010 2011 /* 2012 * Get and verify the address. 2013 */ 2014 2015 if (saddr) { 2016 if (msg->msg_namelen < sizeof(struct sockaddr)) 2017 return -EINVAL; 2018 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 2019 proto = saddr->spkt_protocol; 2020 } else 2021 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 2022 2023 /* 2024 * Find the device first to size check it 2025 */ 2026 2027 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 2028 retry: 2029 rcu_read_lock(); 2030 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 2031 err = -ENODEV; 2032 if (dev == NULL) 2033 goto out_unlock; 2034 2035 err = -ENETDOWN; 2036 if (!(dev->flags & IFF_UP)) 2037 goto out_unlock; 2038 2039 /* 2040 * You may not queue a frame bigger than the mtu. This is the lowest level 2041 * raw protocol and you must do your own fragmentation at this level. 2042 */ 2043 2044 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2045 if (!netif_supports_nofcs(dev)) { 2046 err = -EPROTONOSUPPORT; 2047 goto out_unlock; 2048 } 2049 extra_len = 4; /* We're doing our own CRC */ 2050 } 2051 2052 err = -EMSGSIZE; 2053 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 2054 goto out_unlock; 2055 2056 if (!skb) { 2057 size_t reserved = LL_RESERVED_SPACE(dev); 2058 int tlen = dev->needed_tailroom; 2059 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 2060 2061 rcu_read_unlock(); 2062 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2063 if (skb == NULL) 2064 return -ENOBUFS; 2065 /* FIXME: Save some space for broken drivers that write a hard 2066 * header at transmission time by themselves. PPP is the notable 2067 * one here. This should really be fixed at the driver level. 2068 */ 2069 skb_reserve(skb, reserved); 2070 skb_reset_network_header(skb); 2071 2072 /* Try to align data part correctly */ 2073 if (hhlen) { 2074 skb->data -= hhlen; 2075 skb->tail -= hhlen; 2076 if (len < hhlen) 2077 skb_reset_network_header(skb); 2078 } 2079 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2080 if (err) 2081 goto out_free; 2082 goto retry; 2083 } 2084 2085 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2086 err = -EINVAL; 2087 goto out_unlock; 2088 } 2089 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 2090 !packet_extra_vlan_len_allowed(dev, skb)) { 2091 err = -EMSGSIZE; 2092 goto out_unlock; 2093 } 2094 2095 sockcm_init(&sockc, sk); 2096 if (msg->msg_controllen) { 2097 err = sock_cmsg_send(sk, msg, &sockc); 2098 if (unlikely(err)) 2099 goto out_unlock; 2100 } 2101 2102 skb->protocol = proto; 2103 skb->dev = dev; 2104 skb->priority = READ_ONCE(sk->sk_priority); 2105 skb->mark = READ_ONCE(sk->sk_mark); 2106 skb->tstamp = sockc.transmit_time; 2107 2108 skb_setup_tx_timestamp(skb, sockc.tsflags); 2109 2110 if (unlikely(extra_len == 4)) 2111 skb->no_fcs = 1; 2112 2113 packet_parse_headers(skb, sock); 2114 2115 dev_queue_xmit(skb); 2116 rcu_read_unlock(); 2117 return len; 2118 2119 out_unlock: 2120 rcu_read_unlock(); 2121 out_free: 2122 kfree_skb(skb); 2123 return err; 2124 } 2125 2126 static unsigned int run_filter(struct sk_buff *skb, 2127 const struct sock *sk, 2128 unsigned int res) 2129 { 2130 struct sk_filter *filter; 2131 2132 rcu_read_lock(); 2133 filter = rcu_dereference(sk->sk_filter); 2134 if (filter != NULL) 2135 res = bpf_prog_run_clear_cb(filter->prog, skb); 2136 rcu_read_unlock(); 2137 2138 return res; 2139 } 2140 2141 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2142 size_t *len, int vnet_hdr_sz) 2143 { 2144 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2145 2146 if (*len < vnet_hdr_sz) 2147 return -EINVAL; 2148 *len -= vnet_hdr_sz; 2149 2150 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2151 return -EINVAL; 2152 2153 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2154 } 2155 2156 /* 2157 * This function makes lazy skb cloning in hope that most of packets 2158 * are discarded by BPF. 2159 * 2160 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2161 * and skb->cb are mangled. It works because (and until) packets 2162 * falling here are owned by current CPU. Output packets are cloned 2163 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2164 * sequentially, so that if we return skb to original state on exit, 2165 * we will not harm anyone. 2166 */ 2167 2168 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2169 struct packet_type *pt, struct net_device *orig_dev) 2170 { 2171 struct sock *sk; 2172 struct sockaddr_ll *sll; 2173 struct packet_sock *po; 2174 u8 *skb_head = skb->data; 2175 int skb_len = skb->len; 2176 unsigned int snaplen, res; 2177 bool is_drop_n_account = false; 2178 2179 if (skb->pkt_type == PACKET_LOOPBACK) 2180 goto drop; 2181 2182 sk = pt->af_packet_priv; 2183 po = pkt_sk(sk); 2184 2185 if (!net_eq(dev_net(dev), sock_net(sk))) 2186 goto drop; 2187 2188 skb->dev = dev; 2189 2190 if (dev_has_header(dev)) { 2191 /* The device has an explicit notion of ll header, 2192 * exported to higher levels. 2193 * 2194 * Otherwise, the device hides details of its frame 2195 * structure, so that corresponding packet head is 2196 * never delivered to user. 2197 */ 2198 if (sk->sk_type != SOCK_DGRAM) 2199 skb_push(skb, skb->data - skb_mac_header(skb)); 2200 else if (skb->pkt_type == PACKET_OUTGOING) { 2201 /* Special case: outgoing packets have ll header at head */ 2202 skb_pull(skb, skb_network_offset(skb)); 2203 } 2204 } 2205 2206 snaplen = skb->len; 2207 2208 res = run_filter(skb, sk, snaplen); 2209 if (!res) 2210 goto drop_n_restore; 2211 if (snaplen > res) 2212 snaplen = res; 2213 2214 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2215 goto drop_n_acct; 2216 2217 if (skb_shared(skb)) { 2218 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2219 if (nskb == NULL) 2220 goto drop_n_acct; 2221 2222 if (skb_head != skb->data) { 2223 skb->data = skb_head; 2224 skb->len = skb_len; 2225 } 2226 consume_skb(skb); 2227 skb = nskb; 2228 } 2229 2230 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2231 2232 sll = &PACKET_SKB_CB(skb)->sa.ll; 2233 sll->sll_hatype = dev->type; 2234 sll->sll_pkttype = skb->pkt_type; 2235 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2236 sll->sll_ifindex = orig_dev->ifindex; 2237 else 2238 sll->sll_ifindex = dev->ifindex; 2239 2240 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2241 2242 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2243 * Use their space for storing the original skb length. 2244 */ 2245 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2246 2247 if (pskb_trim(skb, snaplen)) 2248 goto drop_n_acct; 2249 2250 skb_set_owner_r(skb, sk); 2251 skb->dev = NULL; 2252 skb_dst_drop(skb); 2253 2254 /* drop conntrack reference */ 2255 nf_reset_ct(skb); 2256 2257 spin_lock(&sk->sk_receive_queue.lock); 2258 po->stats.stats1.tp_packets++; 2259 sock_skb_set_dropcount(sk, skb); 2260 skb_clear_delivery_time(skb); 2261 __skb_queue_tail(&sk->sk_receive_queue, skb); 2262 spin_unlock(&sk->sk_receive_queue.lock); 2263 sk->sk_data_ready(sk); 2264 return 0; 2265 2266 drop_n_acct: 2267 is_drop_n_account = true; 2268 atomic_inc(&po->tp_drops); 2269 atomic_inc(&sk->sk_drops); 2270 2271 drop_n_restore: 2272 if (skb_head != skb->data && skb_shared(skb)) { 2273 skb->data = skb_head; 2274 skb->len = skb_len; 2275 } 2276 drop: 2277 if (!is_drop_n_account) 2278 consume_skb(skb); 2279 else 2280 kfree_skb(skb); 2281 return 0; 2282 } 2283 2284 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2285 struct packet_type *pt, struct net_device *orig_dev) 2286 { 2287 struct sock *sk; 2288 struct packet_sock *po; 2289 struct sockaddr_ll *sll; 2290 union tpacket_uhdr h; 2291 u8 *skb_head = skb->data; 2292 int skb_len = skb->len; 2293 unsigned int snaplen, res; 2294 unsigned long status = TP_STATUS_USER; 2295 unsigned short macoff, hdrlen; 2296 unsigned int netoff; 2297 struct sk_buff *copy_skb = NULL; 2298 struct timespec64 ts; 2299 __u32 ts_status; 2300 bool is_drop_n_account = false; 2301 unsigned int slot_id = 0; 2302 int vnet_hdr_sz = 0; 2303 2304 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2305 * We may add members to them until current aligned size without forcing 2306 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2307 */ 2308 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2309 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2310 2311 if (skb->pkt_type == PACKET_LOOPBACK) 2312 goto drop; 2313 2314 sk = pt->af_packet_priv; 2315 po = pkt_sk(sk); 2316 2317 if (!net_eq(dev_net(dev), sock_net(sk))) 2318 goto drop; 2319 2320 if (dev_has_header(dev)) { 2321 if (sk->sk_type != SOCK_DGRAM) 2322 skb_push(skb, skb->data - skb_mac_header(skb)); 2323 else if (skb->pkt_type == PACKET_OUTGOING) { 2324 /* Special case: outgoing packets have ll header at head */ 2325 skb_pull(skb, skb_network_offset(skb)); 2326 } 2327 } 2328 2329 snaplen = skb->len; 2330 2331 res = run_filter(skb, sk, snaplen); 2332 if (!res) 2333 goto drop_n_restore; 2334 2335 /* If we are flooded, just give up */ 2336 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2337 atomic_inc(&po->tp_drops); 2338 goto drop_n_restore; 2339 } 2340 2341 if (skb->ip_summed == CHECKSUM_PARTIAL) 2342 status |= TP_STATUS_CSUMNOTREADY; 2343 else if (skb->pkt_type != PACKET_OUTGOING && 2344 skb_csum_unnecessary(skb)) 2345 status |= TP_STATUS_CSUM_VALID; 2346 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2347 status |= TP_STATUS_GSO_TCP; 2348 2349 if (snaplen > res) 2350 snaplen = res; 2351 2352 if (sk->sk_type == SOCK_DGRAM) { 2353 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2354 po->tp_reserve; 2355 } else { 2356 unsigned int maclen = skb_network_offset(skb); 2357 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2358 (maclen < 16 ? 16 : maclen)) + 2359 po->tp_reserve; 2360 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2361 if (vnet_hdr_sz) 2362 netoff += vnet_hdr_sz; 2363 macoff = netoff - maclen; 2364 } 2365 if (netoff > USHRT_MAX) { 2366 atomic_inc(&po->tp_drops); 2367 goto drop_n_restore; 2368 } 2369 if (po->tp_version <= TPACKET_V2) { 2370 if (macoff + snaplen > po->rx_ring.frame_size) { 2371 if (po->copy_thresh && 2372 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2373 if (skb_shared(skb)) { 2374 copy_skb = skb_clone(skb, GFP_ATOMIC); 2375 } else { 2376 copy_skb = skb_get(skb); 2377 skb_head = skb->data; 2378 } 2379 if (copy_skb) { 2380 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2381 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2382 skb_set_owner_r(copy_skb, sk); 2383 } 2384 } 2385 snaplen = po->rx_ring.frame_size - macoff; 2386 if ((int)snaplen < 0) { 2387 snaplen = 0; 2388 vnet_hdr_sz = 0; 2389 } 2390 } 2391 } else if (unlikely(macoff + snaplen > 2392 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2393 u32 nval; 2394 2395 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2396 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2397 snaplen, nval, macoff); 2398 snaplen = nval; 2399 if (unlikely((int)snaplen < 0)) { 2400 snaplen = 0; 2401 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2402 vnet_hdr_sz = 0; 2403 } 2404 } 2405 spin_lock(&sk->sk_receive_queue.lock); 2406 h.raw = packet_current_rx_frame(po, skb, 2407 TP_STATUS_KERNEL, (macoff+snaplen)); 2408 if (!h.raw) 2409 goto drop_n_account; 2410 2411 if (po->tp_version <= TPACKET_V2) { 2412 slot_id = po->rx_ring.head; 2413 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2414 goto drop_n_account; 2415 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2416 } 2417 2418 if (vnet_hdr_sz && 2419 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2420 sizeof(struct virtio_net_hdr), 2421 vio_le(), true, 0)) { 2422 if (po->tp_version == TPACKET_V3) 2423 prb_clear_blk_fill_status(&po->rx_ring); 2424 goto drop_n_account; 2425 } 2426 2427 if (po->tp_version <= TPACKET_V2) { 2428 packet_increment_rx_head(po, &po->rx_ring); 2429 /* 2430 * LOSING will be reported till you read the stats, 2431 * because it's COR - Clear On Read. 2432 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2433 * at packet level. 2434 */ 2435 if (atomic_read(&po->tp_drops)) 2436 status |= TP_STATUS_LOSING; 2437 } 2438 2439 po->stats.stats1.tp_packets++; 2440 if (copy_skb) { 2441 status |= TP_STATUS_COPY; 2442 skb_clear_delivery_time(copy_skb); 2443 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2444 } 2445 spin_unlock(&sk->sk_receive_queue.lock); 2446 2447 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2448 2449 /* Always timestamp; prefer an existing software timestamp taken 2450 * closer to the time of capture. 2451 */ 2452 ts_status = tpacket_get_timestamp(skb, &ts, 2453 READ_ONCE(po->tp_tstamp) | 2454 SOF_TIMESTAMPING_SOFTWARE); 2455 if (!ts_status) 2456 ktime_get_real_ts64(&ts); 2457 2458 status |= ts_status; 2459 2460 switch (po->tp_version) { 2461 case TPACKET_V1: 2462 h.h1->tp_len = skb->len; 2463 h.h1->tp_snaplen = snaplen; 2464 h.h1->tp_mac = macoff; 2465 h.h1->tp_net = netoff; 2466 h.h1->tp_sec = ts.tv_sec; 2467 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2468 hdrlen = sizeof(*h.h1); 2469 break; 2470 case TPACKET_V2: 2471 h.h2->tp_len = skb->len; 2472 h.h2->tp_snaplen = snaplen; 2473 h.h2->tp_mac = macoff; 2474 h.h2->tp_net = netoff; 2475 h.h2->tp_sec = ts.tv_sec; 2476 h.h2->tp_nsec = ts.tv_nsec; 2477 if (skb_vlan_tag_present(skb)) { 2478 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2479 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2480 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2481 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2482 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2483 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2484 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2485 } else { 2486 h.h2->tp_vlan_tci = 0; 2487 h.h2->tp_vlan_tpid = 0; 2488 } 2489 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2490 hdrlen = sizeof(*h.h2); 2491 break; 2492 case TPACKET_V3: 2493 /* tp_nxt_offset,vlan are already populated above. 2494 * So DONT clear those fields here 2495 */ 2496 h.h3->tp_status |= status; 2497 h.h3->tp_len = skb->len; 2498 h.h3->tp_snaplen = snaplen; 2499 h.h3->tp_mac = macoff; 2500 h.h3->tp_net = netoff; 2501 h.h3->tp_sec = ts.tv_sec; 2502 h.h3->tp_nsec = ts.tv_nsec; 2503 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2504 hdrlen = sizeof(*h.h3); 2505 break; 2506 default: 2507 BUG(); 2508 } 2509 2510 sll = h.raw + TPACKET_ALIGN(hdrlen); 2511 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2512 sll->sll_family = AF_PACKET; 2513 sll->sll_hatype = dev->type; 2514 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2515 vlan_get_protocol_dgram(skb) : skb->protocol; 2516 sll->sll_pkttype = skb->pkt_type; 2517 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2518 sll->sll_ifindex = orig_dev->ifindex; 2519 else 2520 sll->sll_ifindex = dev->ifindex; 2521 2522 smp_mb(); 2523 2524 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2525 if (po->tp_version <= TPACKET_V2) { 2526 u8 *start, *end; 2527 2528 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2529 macoff + snaplen); 2530 2531 for (start = h.raw; start < end; start += PAGE_SIZE) 2532 flush_dcache_page(pgv_to_page(start)); 2533 } 2534 smp_wmb(); 2535 #endif 2536 2537 if (po->tp_version <= TPACKET_V2) { 2538 spin_lock(&sk->sk_receive_queue.lock); 2539 __packet_set_status(po, h.raw, status); 2540 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2541 spin_unlock(&sk->sk_receive_queue.lock); 2542 sk->sk_data_ready(sk); 2543 } else if (po->tp_version == TPACKET_V3) { 2544 prb_clear_blk_fill_status(&po->rx_ring); 2545 } 2546 2547 drop_n_restore: 2548 if (skb_head != skb->data && skb_shared(skb)) { 2549 skb->data = skb_head; 2550 skb->len = skb_len; 2551 } 2552 drop: 2553 if (!is_drop_n_account) 2554 consume_skb(skb); 2555 else 2556 kfree_skb(skb); 2557 return 0; 2558 2559 drop_n_account: 2560 spin_unlock(&sk->sk_receive_queue.lock); 2561 atomic_inc(&po->tp_drops); 2562 is_drop_n_account = true; 2563 2564 sk->sk_data_ready(sk); 2565 kfree_skb(copy_skb); 2566 goto drop_n_restore; 2567 } 2568 2569 static void tpacket_destruct_skb(struct sk_buff *skb) 2570 { 2571 struct packet_sock *po = pkt_sk(skb->sk); 2572 2573 if (likely(po->tx_ring.pg_vec)) { 2574 void *ph; 2575 __u32 ts; 2576 2577 ph = skb_zcopy_get_nouarg(skb); 2578 packet_dec_pending(&po->tx_ring); 2579 2580 ts = __packet_set_timestamp(po, ph, skb); 2581 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2582 2583 complete(&po->skb_completion); 2584 } 2585 2586 sock_wfree(skb); 2587 } 2588 2589 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2590 { 2591 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2592 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2593 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2594 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2595 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2596 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2597 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2598 2599 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2600 return -EINVAL; 2601 2602 return 0; 2603 } 2604 2605 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2606 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2607 { 2608 int ret; 2609 2610 if (*len < vnet_hdr_sz) 2611 return -EINVAL; 2612 *len -= vnet_hdr_sz; 2613 2614 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2615 return -EFAULT; 2616 2617 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2618 if (ret) 2619 return ret; 2620 2621 /* move iter to point to the start of mac header */ 2622 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2623 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2624 2625 return 0; 2626 } 2627 2628 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2629 void *frame, struct net_device *dev, void *data, int tp_len, 2630 __be16 proto, unsigned char *addr, int hlen, int copylen, 2631 const struct sockcm_cookie *sockc) 2632 { 2633 union tpacket_uhdr ph; 2634 int to_write, offset, len, nr_frags, len_max; 2635 struct socket *sock = po->sk.sk_socket; 2636 struct page *page; 2637 int err; 2638 2639 ph.raw = frame; 2640 2641 skb->protocol = proto; 2642 skb->dev = dev; 2643 skb->priority = READ_ONCE(po->sk.sk_priority); 2644 skb->mark = READ_ONCE(po->sk.sk_mark); 2645 skb->tstamp = sockc->transmit_time; 2646 skb_setup_tx_timestamp(skb, sockc->tsflags); 2647 skb_zcopy_set_nouarg(skb, ph.raw); 2648 2649 skb_reserve(skb, hlen); 2650 skb_reset_network_header(skb); 2651 2652 to_write = tp_len; 2653 2654 if (sock->type == SOCK_DGRAM) { 2655 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2656 NULL, tp_len); 2657 if (unlikely(err < 0)) 2658 return -EINVAL; 2659 } else if (copylen) { 2660 int hdrlen = min_t(int, copylen, tp_len); 2661 2662 skb_push(skb, dev->hard_header_len); 2663 skb_put(skb, copylen - dev->hard_header_len); 2664 err = skb_store_bits(skb, 0, data, hdrlen); 2665 if (unlikely(err)) 2666 return err; 2667 if (!dev_validate_header(dev, skb->data, hdrlen)) 2668 return -EINVAL; 2669 2670 data += hdrlen; 2671 to_write -= hdrlen; 2672 } 2673 2674 offset = offset_in_page(data); 2675 len_max = PAGE_SIZE - offset; 2676 len = ((to_write > len_max) ? len_max : to_write); 2677 2678 skb->data_len = to_write; 2679 skb->len += to_write; 2680 skb->truesize += to_write; 2681 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2682 2683 while (likely(to_write)) { 2684 nr_frags = skb_shinfo(skb)->nr_frags; 2685 2686 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2687 pr_err("Packet exceed the number of skb frags(%u)\n", 2688 (unsigned int)MAX_SKB_FRAGS); 2689 return -EFAULT; 2690 } 2691 2692 page = pgv_to_page(data); 2693 data += len; 2694 flush_dcache_page(page); 2695 get_page(page); 2696 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2697 to_write -= len; 2698 offset = 0; 2699 len_max = PAGE_SIZE; 2700 len = ((to_write > len_max) ? len_max : to_write); 2701 } 2702 2703 packet_parse_headers(skb, sock); 2704 2705 return tp_len; 2706 } 2707 2708 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2709 int size_max, void **data) 2710 { 2711 union tpacket_uhdr ph; 2712 int tp_len, off; 2713 2714 ph.raw = frame; 2715 2716 switch (po->tp_version) { 2717 case TPACKET_V3: 2718 if (ph.h3->tp_next_offset != 0) { 2719 pr_warn_once("variable sized slot not supported"); 2720 return -EINVAL; 2721 } 2722 tp_len = ph.h3->tp_len; 2723 break; 2724 case TPACKET_V2: 2725 tp_len = ph.h2->tp_len; 2726 break; 2727 default: 2728 tp_len = ph.h1->tp_len; 2729 break; 2730 } 2731 if (unlikely(tp_len > size_max)) { 2732 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2733 return -EMSGSIZE; 2734 } 2735 2736 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2737 int off_min, off_max; 2738 2739 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2740 off_max = po->tx_ring.frame_size - tp_len; 2741 if (po->sk.sk_type == SOCK_DGRAM) { 2742 switch (po->tp_version) { 2743 case TPACKET_V3: 2744 off = ph.h3->tp_net; 2745 break; 2746 case TPACKET_V2: 2747 off = ph.h2->tp_net; 2748 break; 2749 default: 2750 off = ph.h1->tp_net; 2751 break; 2752 } 2753 } else { 2754 switch (po->tp_version) { 2755 case TPACKET_V3: 2756 off = ph.h3->tp_mac; 2757 break; 2758 case TPACKET_V2: 2759 off = ph.h2->tp_mac; 2760 break; 2761 default: 2762 off = ph.h1->tp_mac; 2763 break; 2764 } 2765 } 2766 if (unlikely((off < off_min) || (off_max < off))) 2767 return -EINVAL; 2768 } else { 2769 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2770 } 2771 2772 *data = frame + off; 2773 return tp_len; 2774 } 2775 2776 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2777 { 2778 struct sk_buff *skb = NULL; 2779 struct net_device *dev; 2780 struct virtio_net_hdr *vnet_hdr = NULL; 2781 struct sockcm_cookie sockc; 2782 __be16 proto; 2783 int err, reserve = 0; 2784 void *ph; 2785 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2786 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2787 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2788 unsigned char *addr = NULL; 2789 int tp_len, size_max; 2790 void *data; 2791 int len_sum = 0; 2792 int status = TP_STATUS_AVAILABLE; 2793 int hlen, tlen, copylen = 0; 2794 long timeo = 0; 2795 2796 mutex_lock(&po->pg_vec_lock); 2797 2798 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2799 * we need to confirm it under protection of pg_vec_lock. 2800 */ 2801 if (unlikely(!po->tx_ring.pg_vec)) { 2802 err = -EBUSY; 2803 goto out; 2804 } 2805 if (likely(saddr == NULL)) { 2806 dev = packet_cached_dev_get(po); 2807 proto = READ_ONCE(po->num); 2808 } else { 2809 err = -EINVAL; 2810 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2811 goto out; 2812 if (msg->msg_namelen < (saddr->sll_halen 2813 + offsetof(struct sockaddr_ll, 2814 sll_addr))) 2815 goto out; 2816 proto = saddr->sll_protocol; 2817 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2818 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2819 if (dev && msg->msg_namelen < dev->addr_len + 2820 offsetof(struct sockaddr_ll, sll_addr)) 2821 goto out_put; 2822 addr = saddr->sll_addr; 2823 } 2824 } 2825 2826 err = -ENXIO; 2827 if (unlikely(dev == NULL)) 2828 goto out; 2829 err = -ENETDOWN; 2830 if (unlikely(!(dev->flags & IFF_UP))) 2831 goto out_put; 2832 2833 sockcm_init(&sockc, &po->sk); 2834 if (msg->msg_controllen) { 2835 err = sock_cmsg_send(&po->sk, msg, &sockc); 2836 if (unlikely(err)) 2837 goto out_put; 2838 } 2839 2840 if (po->sk.sk_socket->type == SOCK_RAW) 2841 reserve = dev->hard_header_len; 2842 size_max = po->tx_ring.frame_size 2843 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2844 2845 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2846 size_max = dev->mtu + reserve + VLAN_HLEN; 2847 2848 reinit_completion(&po->skb_completion); 2849 2850 do { 2851 ph = packet_current_frame(po, &po->tx_ring, 2852 TP_STATUS_SEND_REQUEST); 2853 if (unlikely(ph == NULL)) { 2854 if (need_wait && skb) { 2855 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2856 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2857 if (timeo <= 0) { 2858 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2859 goto out_put; 2860 } 2861 } 2862 /* check for additional frames */ 2863 continue; 2864 } 2865 2866 skb = NULL; 2867 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2868 if (tp_len < 0) 2869 goto tpacket_error; 2870 2871 status = TP_STATUS_SEND_REQUEST; 2872 hlen = LL_RESERVED_SPACE(dev); 2873 tlen = dev->needed_tailroom; 2874 if (vnet_hdr_sz) { 2875 vnet_hdr = data; 2876 data += vnet_hdr_sz; 2877 tp_len -= vnet_hdr_sz; 2878 if (tp_len < 0 || 2879 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2880 tp_len = -EINVAL; 2881 goto tpacket_error; 2882 } 2883 copylen = __virtio16_to_cpu(vio_le(), 2884 vnet_hdr->hdr_len); 2885 } 2886 copylen = max_t(int, copylen, dev->hard_header_len); 2887 skb = sock_alloc_send_skb(&po->sk, 2888 hlen + tlen + sizeof(struct sockaddr_ll) + 2889 (copylen - dev->hard_header_len), 2890 !need_wait, &err); 2891 2892 if (unlikely(skb == NULL)) { 2893 /* we assume the socket was initially writeable ... */ 2894 if (likely(len_sum > 0)) 2895 err = len_sum; 2896 goto out_status; 2897 } 2898 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2899 addr, hlen, copylen, &sockc); 2900 if (likely(tp_len >= 0) && 2901 tp_len > dev->mtu + reserve && 2902 !vnet_hdr_sz && 2903 !packet_extra_vlan_len_allowed(dev, skb)) 2904 tp_len = -EMSGSIZE; 2905 2906 if (unlikely(tp_len < 0)) { 2907 tpacket_error: 2908 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2909 __packet_set_status(po, ph, 2910 TP_STATUS_AVAILABLE); 2911 packet_increment_head(&po->tx_ring); 2912 kfree_skb(skb); 2913 continue; 2914 } else { 2915 status = TP_STATUS_WRONG_FORMAT; 2916 err = tp_len; 2917 goto out_status; 2918 } 2919 } 2920 2921 if (vnet_hdr_sz) { 2922 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { 2923 tp_len = -EINVAL; 2924 goto tpacket_error; 2925 } 2926 virtio_net_hdr_set_proto(skb, vnet_hdr); 2927 } 2928 2929 skb->destructor = tpacket_destruct_skb; 2930 __packet_set_status(po, ph, TP_STATUS_SENDING); 2931 packet_inc_pending(&po->tx_ring); 2932 2933 status = TP_STATUS_SEND_REQUEST; 2934 err = packet_xmit(po, skb); 2935 if (unlikely(err != 0)) { 2936 if (err > 0) 2937 err = net_xmit_errno(err); 2938 if (err && __packet_get_status(po, ph) == 2939 TP_STATUS_AVAILABLE) { 2940 /* skb was destructed already */ 2941 skb = NULL; 2942 goto out_status; 2943 } 2944 /* 2945 * skb was dropped but not destructed yet; 2946 * let's treat it like congestion or err < 0 2947 */ 2948 err = 0; 2949 } 2950 packet_increment_head(&po->tx_ring); 2951 len_sum += tp_len; 2952 } while (likely((ph != NULL) || 2953 /* Note: packet_read_pending() might be slow if we have 2954 * to call it as it's per_cpu variable, but in fast-path 2955 * we already short-circuit the loop with the first 2956 * condition, and luckily don't have to go that path 2957 * anyway. 2958 */ 2959 (need_wait && packet_read_pending(&po->tx_ring)))); 2960 2961 err = len_sum; 2962 goto out_put; 2963 2964 out_status: 2965 __packet_set_status(po, ph, status); 2966 kfree_skb(skb); 2967 out_put: 2968 dev_put(dev); 2969 out: 2970 mutex_unlock(&po->pg_vec_lock); 2971 return err; 2972 } 2973 2974 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2975 size_t reserve, size_t len, 2976 size_t linear, int noblock, 2977 int *err) 2978 { 2979 struct sk_buff *skb; 2980 2981 /* Under a page? Don't bother with paged skb. */ 2982 if (prepad + len < PAGE_SIZE || !linear) 2983 linear = len; 2984 2985 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2986 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2987 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2988 err, PAGE_ALLOC_COSTLY_ORDER); 2989 if (!skb) 2990 return NULL; 2991 2992 skb_reserve(skb, reserve); 2993 skb_put(skb, linear); 2994 skb->data_len = len - linear; 2995 skb->len += len - linear; 2996 2997 return skb; 2998 } 2999 3000 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 3001 { 3002 struct sock *sk = sock->sk; 3003 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 3004 struct sk_buff *skb; 3005 struct net_device *dev; 3006 __be16 proto; 3007 unsigned char *addr = NULL; 3008 int err, reserve = 0; 3009 struct sockcm_cookie sockc; 3010 struct virtio_net_hdr vnet_hdr = { 0 }; 3011 int offset = 0; 3012 struct packet_sock *po = pkt_sk(sk); 3013 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 3014 int hlen, tlen, linear; 3015 int extra_len = 0; 3016 3017 /* 3018 * Get and verify the address. 3019 */ 3020 3021 if (likely(saddr == NULL)) { 3022 dev = packet_cached_dev_get(po); 3023 proto = READ_ONCE(po->num); 3024 } else { 3025 err = -EINVAL; 3026 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 3027 goto out; 3028 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 3029 goto out; 3030 proto = saddr->sll_protocol; 3031 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 3032 if (sock->type == SOCK_DGRAM) { 3033 if (dev && msg->msg_namelen < dev->addr_len + 3034 offsetof(struct sockaddr_ll, sll_addr)) 3035 goto out_unlock; 3036 addr = saddr->sll_addr; 3037 } 3038 } 3039 3040 err = -ENXIO; 3041 if (unlikely(dev == NULL)) 3042 goto out_unlock; 3043 err = -ENETDOWN; 3044 if (unlikely(!(dev->flags & IFF_UP))) 3045 goto out_unlock; 3046 3047 sockcm_init(&sockc, sk); 3048 sockc.mark = READ_ONCE(sk->sk_mark); 3049 if (msg->msg_controllen) { 3050 err = sock_cmsg_send(sk, msg, &sockc); 3051 if (unlikely(err)) 3052 goto out_unlock; 3053 } 3054 3055 if (sock->type == SOCK_RAW) 3056 reserve = dev->hard_header_len; 3057 if (vnet_hdr_sz) { 3058 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3059 if (err) 3060 goto out_unlock; 3061 } 3062 3063 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3064 if (!netif_supports_nofcs(dev)) { 3065 err = -EPROTONOSUPPORT; 3066 goto out_unlock; 3067 } 3068 extra_len = 4; /* We're doing our own CRC */ 3069 } 3070 3071 err = -EMSGSIZE; 3072 if (!vnet_hdr.gso_type && 3073 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3074 goto out_unlock; 3075 3076 err = -ENOBUFS; 3077 hlen = LL_RESERVED_SPACE(dev); 3078 tlen = dev->needed_tailroom; 3079 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3080 linear = max(linear, min_t(int, len, dev->hard_header_len)); 3081 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3082 msg->msg_flags & MSG_DONTWAIT, &err); 3083 if (skb == NULL) 3084 goto out_unlock; 3085 3086 skb_reset_network_header(skb); 3087 3088 err = -EINVAL; 3089 if (sock->type == SOCK_DGRAM) { 3090 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3091 if (unlikely(offset < 0)) 3092 goto out_free; 3093 } else if (reserve) { 3094 skb_reserve(skb, -reserve); 3095 if (len < reserve + sizeof(struct ipv6hdr) && 3096 dev->min_header_len != dev->hard_header_len) 3097 skb_reset_network_header(skb); 3098 } 3099 3100 /* Returns -EFAULT on error */ 3101 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3102 if (err) 3103 goto out_free; 3104 3105 if ((sock->type == SOCK_RAW && 3106 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3107 err = -EINVAL; 3108 goto out_free; 3109 } 3110 3111 skb_setup_tx_timestamp(skb, sockc.tsflags); 3112 3113 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3114 !packet_extra_vlan_len_allowed(dev, skb)) { 3115 err = -EMSGSIZE; 3116 goto out_free; 3117 } 3118 3119 skb->protocol = proto; 3120 skb->dev = dev; 3121 skb->priority = READ_ONCE(sk->sk_priority); 3122 skb->mark = sockc.mark; 3123 skb->tstamp = sockc.transmit_time; 3124 3125 if (unlikely(extra_len == 4)) 3126 skb->no_fcs = 1; 3127 3128 packet_parse_headers(skb, sock); 3129 3130 if (vnet_hdr_sz) { 3131 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3132 if (err) 3133 goto out_free; 3134 len += vnet_hdr_sz; 3135 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3136 } 3137 3138 err = packet_xmit(po, skb); 3139 3140 if (unlikely(err != 0)) { 3141 if (err > 0) 3142 err = net_xmit_errno(err); 3143 if (err) 3144 goto out_unlock; 3145 } 3146 3147 dev_put(dev); 3148 3149 return len; 3150 3151 out_free: 3152 kfree_skb(skb); 3153 out_unlock: 3154 dev_put(dev); 3155 out: 3156 return err; 3157 } 3158 3159 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3160 { 3161 struct sock *sk = sock->sk; 3162 struct packet_sock *po = pkt_sk(sk); 3163 3164 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3165 * tpacket_snd() will redo the check safely. 3166 */ 3167 if (data_race(po->tx_ring.pg_vec)) 3168 return tpacket_snd(po, msg); 3169 3170 return packet_snd(sock, msg, len); 3171 } 3172 3173 /* 3174 * Close a PACKET socket. This is fairly simple. We immediately go 3175 * to 'closed' state and remove our protocol entry in the device list. 3176 */ 3177 3178 static int packet_release(struct socket *sock) 3179 { 3180 struct sock *sk = sock->sk; 3181 struct packet_sock *po; 3182 struct packet_fanout *f; 3183 struct net *net; 3184 union tpacket_req_u req_u; 3185 3186 if (!sk) 3187 return 0; 3188 3189 net = sock_net(sk); 3190 po = pkt_sk(sk); 3191 3192 mutex_lock(&net->packet.sklist_lock); 3193 sk_del_node_init_rcu(sk); 3194 mutex_unlock(&net->packet.sklist_lock); 3195 3196 sock_prot_inuse_add(net, sk->sk_prot, -1); 3197 3198 spin_lock(&po->bind_lock); 3199 unregister_prot_hook(sk, false); 3200 packet_cached_dev_reset(po); 3201 3202 if (po->prot_hook.dev) { 3203 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3204 po->prot_hook.dev = NULL; 3205 } 3206 spin_unlock(&po->bind_lock); 3207 3208 packet_flush_mclist(sk); 3209 3210 lock_sock(sk); 3211 if (po->rx_ring.pg_vec) { 3212 memset(&req_u, 0, sizeof(req_u)); 3213 packet_set_ring(sk, &req_u, 1, 0); 3214 } 3215 3216 if (po->tx_ring.pg_vec) { 3217 memset(&req_u, 0, sizeof(req_u)); 3218 packet_set_ring(sk, &req_u, 1, 1); 3219 } 3220 release_sock(sk); 3221 3222 f = fanout_release(sk); 3223 3224 synchronize_net(); 3225 3226 kfree(po->rollover); 3227 if (f) { 3228 fanout_release_data(f); 3229 kvfree(f); 3230 } 3231 /* 3232 * Now the socket is dead. No more input will appear. 3233 */ 3234 sock_orphan(sk); 3235 sock->sk = NULL; 3236 3237 /* Purge queues */ 3238 3239 skb_queue_purge(&sk->sk_receive_queue); 3240 packet_free_pending(po); 3241 3242 sock_put(sk); 3243 return 0; 3244 } 3245 3246 /* 3247 * Attach a packet hook. 3248 */ 3249 3250 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3251 __be16 proto) 3252 { 3253 struct packet_sock *po = pkt_sk(sk); 3254 struct net_device *dev = NULL; 3255 bool unlisted = false; 3256 bool need_rehook; 3257 int ret = 0; 3258 3259 lock_sock(sk); 3260 spin_lock(&po->bind_lock); 3261 if (!proto) 3262 proto = po->num; 3263 3264 rcu_read_lock(); 3265 3266 if (po->fanout) { 3267 ret = -EINVAL; 3268 goto out_unlock; 3269 } 3270 3271 if (name) { 3272 dev = dev_get_by_name_rcu(sock_net(sk), name); 3273 if (!dev) { 3274 ret = -ENODEV; 3275 goto out_unlock; 3276 } 3277 } else if (ifindex) { 3278 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3279 if (!dev) { 3280 ret = -ENODEV; 3281 goto out_unlock; 3282 } 3283 } 3284 3285 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3286 3287 if (need_rehook) { 3288 dev_hold(dev); 3289 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3290 rcu_read_unlock(); 3291 /* prevents packet_notifier() from calling 3292 * register_prot_hook() 3293 */ 3294 WRITE_ONCE(po->num, 0); 3295 __unregister_prot_hook(sk, true); 3296 rcu_read_lock(); 3297 if (dev) 3298 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3299 dev->ifindex); 3300 } 3301 3302 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3303 WRITE_ONCE(po->num, proto); 3304 po->prot_hook.type = proto; 3305 3306 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3307 3308 if (unlikely(unlisted)) { 3309 po->prot_hook.dev = NULL; 3310 WRITE_ONCE(po->ifindex, -1); 3311 packet_cached_dev_reset(po); 3312 } else { 3313 netdev_hold(dev, &po->prot_hook.dev_tracker, 3314 GFP_ATOMIC); 3315 po->prot_hook.dev = dev; 3316 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3317 packet_cached_dev_assign(po, dev); 3318 } 3319 dev_put(dev); 3320 } 3321 3322 if (proto == 0 || !need_rehook) 3323 goto out_unlock; 3324 3325 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3326 register_prot_hook(sk); 3327 } else { 3328 sk->sk_err = ENETDOWN; 3329 if (!sock_flag(sk, SOCK_DEAD)) 3330 sk_error_report(sk); 3331 } 3332 3333 out_unlock: 3334 rcu_read_unlock(); 3335 spin_unlock(&po->bind_lock); 3336 release_sock(sk); 3337 return ret; 3338 } 3339 3340 /* 3341 * Bind a packet socket to a device 3342 */ 3343 3344 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3345 int addr_len) 3346 { 3347 struct sock *sk = sock->sk; 3348 char name[sizeof(uaddr->sa_data_min) + 1]; 3349 3350 /* 3351 * Check legality 3352 */ 3353 3354 if (addr_len != sizeof(struct sockaddr)) 3355 return -EINVAL; 3356 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3357 * zero-terminated. 3358 */ 3359 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min)); 3360 name[sizeof(uaddr->sa_data_min)] = 0; 3361 3362 return packet_do_bind(sk, name, 0, 0); 3363 } 3364 3365 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3366 { 3367 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3368 struct sock *sk = sock->sk; 3369 3370 /* 3371 * Check legality 3372 */ 3373 3374 if (addr_len < sizeof(struct sockaddr_ll)) 3375 return -EINVAL; 3376 if (sll->sll_family != AF_PACKET) 3377 return -EINVAL; 3378 3379 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3380 } 3381 3382 static struct proto packet_proto = { 3383 .name = "PACKET", 3384 .owner = THIS_MODULE, 3385 .obj_size = sizeof(struct packet_sock), 3386 }; 3387 3388 /* 3389 * Create a packet of type SOCK_PACKET. 3390 */ 3391 3392 static int packet_create(struct net *net, struct socket *sock, int protocol, 3393 int kern) 3394 { 3395 struct sock *sk; 3396 struct packet_sock *po; 3397 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3398 int err; 3399 3400 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3401 return -EPERM; 3402 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3403 sock->type != SOCK_PACKET) 3404 return -ESOCKTNOSUPPORT; 3405 3406 sock->state = SS_UNCONNECTED; 3407 3408 err = -ENOBUFS; 3409 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3410 if (sk == NULL) 3411 goto out; 3412 3413 sock->ops = &packet_ops; 3414 if (sock->type == SOCK_PACKET) 3415 sock->ops = &packet_ops_spkt; 3416 3417 po = pkt_sk(sk); 3418 err = packet_alloc_pending(po); 3419 if (err) 3420 goto out_sk_free; 3421 3422 sock_init_data(sock, sk); 3423 3424 init_completion(&po->skb_completion); 3425 sk->sk_family = PF_PACKET; 3426 po->num = proto; 3427 3428 packet_cached_dev_reset(po); 3429 3430 sk->sk_destruct = packet_sock_destruct; 3431 3432 /* 3433 * Attach a protocol block 3434 */ 3435 3436 spin_lock_init(&po->bind_lock); 3437 mutex_init(&po->pg_vec_lock); 3438 po->rollover = NULL; 3439 po->prot_hook.func = packet_rcv; 3440 3441 if (sock->type == SOCK_PACKET) 3442 po->prot_hook.func = packet_rcv_spkt; 3443 3444 po->prot_hook.af_packet_priv = sk; 3445 po->prot_hook.af_packet_net = sock_net(sk); 3446 3447 if (proto) { 3448 po->prot_hook.type = proto; 3449 __register_prot_hook(sk); 3450 } 3451 3452 mutex_lock(&net->packet.sklist_lock); 3453 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3454 mutex_unlock(&net->packet.sklist_lock); 3455 3456 sock_prot_inuse_add(net, &packet_proto, 1); 3457 3458 return 0; 3459 out_sk_free: 3460 sk_free(sk); 3461 out: 3462 return err; 3463 } 3464 3465 /* 3466 * Pull a packet from our receive queue and hand it to the user. 3467 * If necessary we block. 3468 */ 3469 3470 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3471 int flags) 3472 { 3473 struct sock *sk = sock->sk; 3474 struct sk_buff *skb; 3475 int copied, err; 3476 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3477 unsigned int origlen = 0; 3478 3479 err = -EINVAL; 3480 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3481 goto out; 3482 3483 #if 0 3484 /* What error should we return now? EUNATTACH? */ 3485 if (pkt_sk(sk)->ifindex < 0) 3486 return -ENODEV; 3487 #endif 3488 3489 if (flags & MSG_ERRQUEUE) { 3490 err = sock_recv_errqueue(sk, msg, len, 3491 SOL_PACKET, PACKET_TX_TIMESTAMP); 3492 goto out; 3493 } 3494 3495 /* 3496 * Call the generic datagram receiver. This handles all sorts 3497 * of horrible races and re-entrancy so we can forget about it 3498 * in the protocol layers. 3499 * 3500 * Now it will return ENETDOWN, if device have just gone down, 3501 * but then it will block. 3502 */ 3503 3504 skb = skb_recv_datagram(sk, flags, &err); 3505 3506 /* 3507 * An error occurred so return it. Because skb_recv_datagram() 3508 * handles the blocking we don't see and worry about blocking 3509 * retries. 3510 */ 3511 3512 if (skb == NULL) 3513 goto out; 3514 3515 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3516 3517 if (vnet_hdr_len) { 3518 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3519 if (err) 3520 goto out_free; 3521 } 3522 3523 /* You lose any data beyond the buffer you gave. If it worries 3524 * a user program they can ask the device for its MTU 3525 * anyway. 3526 */ 3527 copied = skb->len; 3528 if (copied > len) { 3529 copied = len; 3530 msg->msg_flags |= MSG_TRUNC; 3531 } 3532 3533 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3534 if (err) 3535 goto out_free; 3536 3537 if (sock->type != SOCK_PACKET) { 3538 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3539 3540 /* Original length was stored in sockaddr_ll fields */ 3541 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3542 sll->sll_family = AF_PACKET; 3543 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3544 vlan_get_protocol_dgram(skb) : skb->protocol; 3545 } 3546 3547 sock_recv_cmsgs(msg, sk, skb); 3548 3549 if (msg->msg_name) { 3550 const size_t max_len = min(sizeof(skb->cb), 3551 sizeof(struct sockaddr_storage)); 3552 int copy_len; 3553 3554 /* If the address length field is there to be filled 3555 * in, we fill it in now. 3556 */ 3557 if (sock->type == SOCK_PACKET) { 3558 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3559 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3560 copy_len = msg->msg_namelen; 3561 } else { 3562 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3563 3564 msg->msg_namelen = sll->sll_halen + 3565 offsetof(struct sockaddr_ll, sll_addr); 3566 copy_len = msg->msg_namelen; 3567 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3568 memset(msg->msg_name + 3569 offsetof(struct sockaddr_ll, sll_addr), 3570 0, sizeof(sll->sll_addr)); 3571 msg->msg_namelen = sizeof(struct sockaddr_ll); 3572 } 3573 } 3574 if (WARN_ON_ONCE(copy_len > max_len)) { 3575 copy_len = max_len; 3576 msg->msg_namelen = copy_len; 3577 } 3578 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3579 } 3580 3581 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3582 struct tpacket_auxdata aux; 3583 3584 aux.tp_status = TP_STATUS_USER; 3585 if (skb->ip_summed == CHECKSUM_PARTIAL) 3586 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3587 else if (skb->pkt_type != PACKET_OUTGOING && 3588 skb_csum_unnecessary(skb)) 3589 aux.tp_status |= TP_STATUS_CSUM_VALID; 3590 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3591 aux.tp_status |= TP_STATUS_GSO_TCP; 3592 3593 aux.tp_len = origlen; 3594 aux.tp_snaplen = skb->len; 3595 aux.tp_mac = 0; 3596 aux.tp_net = skb_network_offset(skb); 3597 if (skb_vlan_tag_present(skb)) { 3598 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3599 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3600 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3601 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3602 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3603 struct net_device *dev; 3604 3605 rcu_read_lock(); 3606 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3607 if (dev) { 3608 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3609 aux.tp_vlan_tpid = ntohs(skb->protocol); 3610 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3611 } else { 3612 aux.tp_vlan_tci = 0; 3613 aux.tp_vlan_tpid = 0; 3614 } 3615 rcu_read_unlock(); 3616 } else { 3617 aux.tp_vlan_tci = 0; 3618 aux.tp_vlan_tpid = 0; 3619 } 3620 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3621 } 3622 3623 /* 3624 * Free or return the buffer as appropriate. Again this 3625 * hides all the races and re-entrancy issues from us. 3626 */ 3627 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3628 3629 out_free: 3630 skb_free_datagram(sk, skb); 3631 out: 3632 return err; 3633 } 3634 3635 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3636 int peer) 3637 { 3638 struct net_device *dev; 3639 struct sock *sk = sock->sk; 3640 3641 if (peer) 3642 return -EOPNOTSUPP; 3643 3644 uaddr->sa_family = AF_PACKET; 3645 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min)); 3646 rcu_read_lock(); 3647 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3648 if (dev) 3649 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min)); 3650 rcu_read_unlock(); 3651 3652 return sizeof(*uaddr); 3653 } 3654 3655 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3656 int peer) 3657 { 3658 struct net_device *dev; 3659 struct sock *sk = sock->sk; 3660 struct packet_sock *po = pkt_sk(sk); 3661 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3662 int ifindex; 3663 3664 if (peer) 3665 return -EOPNOTSUPP; 3666 3667 ifindex = READ_ONCE(po->ifindex); 3668 sll->sll_family = AF_PACKET; 3669 sll->sll_ifindex = ifindex; 3670 sll->sll_protocol = READ_ONCE(po->num); 3671 sll->sll_pkttype = 0; 3672 rcu_read_lock(); 3673 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3674 if (dev) { 3675 sll->sll_hatype = dev->type; 3676 sll->sll_halen = dev->addr_len; 3677 3678 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3679 memcpy(((struct sockaddr_storage *)sll)->__data + 3680 offsetof(struct sockaddr_ll, sll_addr) - 3681 offsetofend(struct sockaddr_ll, sll_family), 3682 dev->dev_addr, dev->addr_len); 3683 } else { 3684 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3685 sll->sll_halen = 0; 3686 } 3687 rcu_read_unlock(); 3688 3689 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3690 } 3691 3692 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3693 int what) 3694 { 3695 switch (i->type) { 3696 case PACKET_MR_MULTICAST: 3697 if (i->alen != dev->addr_len) 3698 return -EINVAL; 3699 if (what > 0) 3700 return dev_mc_add(dev, i->addr); 3701 else 3702 return dev_mc_del(dev, i->addr); 3703 break; 3704 case PACKET_MR_PROMISC: 3705 return dev_set_promiscuity(dev, what); 3706 case PACKET_MR_ALLMULTI: 3707 return dev_set_allmulti(dev, what); 3708 case PACKET_MR_UNICAST: 3709 if (i->alen != dev->addr_len) 3710 return -EINVAL; 3711 if (what > 0) 3712 return dev_uc_add(dev, i->addr); 3713 else 3714 return dev_uc_del(dev, i->addr); 3715 break; 3716 default: 3717 break; 3718 } 3719 return 0; 3720 } 3721 3722 static void packet_dev_mclist_delete(struct net_device *dev, 3723 struct packet_mclist **mlp) 3724 { 3725 struct packet_mclist *ml; 3726 3727 while ((ml = *mlp) != NULL) { 3728 if (ml->ifindex == dev->ifindex) { 3729 packet_dev_mc(dev, ml, -1); 3730 *mlp = ml->next; 3731 kfree(ml); 3732 } else 3733 mlp = &ml->next; 3734 } 3735 } 3736 3737 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3738 { 3739 struct packet_sock *po = pkt_sk(sk); 3740 struct packet_mclist *ml, *i; 3741 struct net_device *dev; 3742 int err; 3743 3744 rtnl_lock(); 3745 3746 err = -ENODEV; 3747 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3748 if (!dev) 3749 goto done; 3750 3751 err = -EINVAL; 3752 if (mreq->mr_alen > dev->addr_len) 3753 goto done; 3754 3755 err = -ENOBUFS; 3756 i = kmalloc(sizeof(*i), GFP_KERNEL); 3757 if (i == NULL) 3758 goto done; 3759 3760 err = 0; 3761 for (ml = po->mclist; ml; ml = ml->next) { 3762 if (ml->ifindex == mreq->mr_ifindex && 3763 ml->type == mreq->mr_type && 3764 ml->alen == mreq->mr_alen && 3765 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3766 ml->count++; 3767 /* Free the new element ... */ 3768 kfree(i); 3769 goto done; 3770 } 3771 } 3772 3773 i->type = mreq->mr_type; 3774 i->ifindex = mreq->mr_ifindex; 3775 i->alen = mreq->mr_alen; 3776 memcpy(i->addr, mreq->mr_address, i->alen); 3777 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3778 i->count = 1; 3779 i->next = po->mclist; 3780 po->mclist = i; 3781 err = packet_dev_mc(dev, i, 1); 3782 if (err) { 3783 po->mclist = i->next; 3784 kfree(i); 3785 } 3786 3787 done: 3788 rtnl_unlock(); 3789 return err; 3790 } 3791 3792 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3793 { 3794 struct packet_mclist *ml, **mlp; 3795 3796 rtnl_lock(); 3797 3798 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3799 if (ml->ifindex == mreq->mr_ifindex && 3800 ml->type == mreq->mr_type && 3801 ml->alen == mreq->mr_alen && 3802 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3803 if (--ml->count == 0) { 3804 struct net_device *dev; 3805 *mlp = ml->next; 3806 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3807 if (dev) 3808 packet_dev_mc(dev, ml, -1); 3809 kfree(ml); 3810 } 3811 break; 3812 } 3813 } 3814 rtnl_unlock(); 3815 return 0; 3816 } 3817 3818 static void packet_flush_mclist(struct sock *sk) 3819 { 3820 struct packet_sock *po = pkt_sk(sk); 3821 struct packet_mclist *ml; 3822 3823 if (!po->mclist) 3824 return; 3825 3826 rtnl_lock(); 3827 while ((ml = po->mclist) != NULL) { 3828 struct net_device *dev; 3829 3830 po->mclist = ml->next; 3831 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3832 if (dev != NULL) 3833 packet_dev_mc(dev, ml, -1); 3834 kfree(ml); 3835 } 3836 rtnl_unlock(); 3837 } 3838 3839 static int 3840 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3841 unsigned int optlen) 3842 { 3843 struct sock *sk = sock->sk; 3844 struct packet_sock *po = pkt_sk(sk); 3845 int ret; 3846 3847 if (level != SOL_PACKET) 3848 return -ENOPROTOOPT; 3849 3850 switch (optname) { 3851 case PACKET_ADD_MEMBERSHIP: 3852 case PACKET_DROP_MEMBERSHIP: 3853 { 3854 struct packet_mreq_max mreq; 3855 int len = optlen; 3856 memset(&mreq, 0, sizeof(mreq)); 3857 if (len < sizeof(struct packet_mreq)) 3858 return -EINVAL; 3859 if (len > sizeof(mreq)) 3860 len = sizeof(mreq); 3861 if (copy_from_sockptr(&mreq, optval, len)) 3862 return -EFAULT; 3863 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3864 return -EINVAL; 3865 if (optname == PACKET_ADD_MEMBERSHIP) 3866 ret = packet_mc_add(sk, &mreq); 3867 else 3868 ret = packet_mc_drop(sk, &mreq); 3869 return ret; 3870 } 3871 3872 case PACKET_RX_RING: 3873 case PACKET_TX_RING: 3874 { 3875 union tpacket_req_u req_u; 3876 3877 ret = -EINVAL; 3878 lock_sock(sk); 3879 switch (po->tp_version) { 3880 case TPACKET_V1: 3881 case TPACKET_V2: 3882 if (optlen < sizeof(req_u.req)) 3883 break; 3884 ret = copy_from_sockptr(&req_u.req, optval, 3885 sizeof(req_u.req)) ? 3886 -EINVAL : 0; 3887 break; 3888 case TPACKET_V3: 3889 default: 3890 if (optlen < sizeof(req_u.req3)) 3891 break; 3892 ret = copy_from_sockptr(&req_u.req3, optval, 3893 sizeof(req_u.req3)) ? 3894 -EINVAL : 0; 3895 break; 3896 } 3897 if (!ret) 3898 ret = packet_set_ring(sk, &req_u, 0, 3899 optname == PACKET_TX_RING); 3900 release_sock(sk); 3901 return ret; 3902 } 3903 case PACKET_COPY_THRESH: 3904 { 3905 int val; 3906 3907 if (optlen != sizeof(val)) 3908 return -EINVAL; 3909 if (copy_from_sockptr(&val, optval, sizeof(val))) 3910 return -EFAULT; 3911 3912 pkt_sk(sk)->copy_thresh = val; 3913 return 0; 3914 } 3915 case PACKET_VERSION: 3916 { 3917 int val; 3918 3919 if (optlen != sizeof(val)) 3920 return -EINVAL; 3921 if (copy_from_sockptr(&val, optval, sizeof(val))) 3922 return -EFAULT; 3923 switch (val) { 3924 case TPACKET_V1: 3925 case TPACKET_V2: 3926 case TPACKET_V3: 3927 break; 3928 default: 3929 return -EINVAL; 3930 } 3931 lock_sock(sk); 3932 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3933 ret = -EBUSY; 3934 } else { 3935 po->tp_version = val; 3936 ret = 0; 3937 } 3938 release_sock(sk); 3939 return ret; 3940 } 3941 case PACKET_RESERVE: 3942 { 3943 unsigned int val; 3944 3945 if (optlen != sizeof(val)) 3946 return -EINVAL; 3947 if (copy_from_sockptr(&val, optval, sizeof(val))) 3948 return -EFAULT; 3949 if (val > INT_MAX) 3950 return -EINVAL; 3951 lock_sock(sk); 3952 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3953 ret = -EBUSY; 3954 } else { 3955 po->tp_reserve = val; 3956 ret = 0; 3957 } 3958 release_sock(sk); 3959 return ret; 3960 } 3961 case PACKET_LOSS: 3962 { 3963 unsigned int val; 3964 3965 if (optlen != sizeof(val)) 3966 return -EINVAL; 3967 if (copy_from_sockptr(&val, optval, sizeof(val))) 3968 return -EFAULT; 3969 3970 lock_sock(sk); 3971 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3972 ret = -EBUSY; 3973 } else { 3974 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3975 ret = 0; 3976 } 3977 release_sock(sk); 3978 return ret; 3979 } 3980 case PACKET_AUXDATA: 3981 { 3982 int val; 3983 3984 if (optlen < sizeof(val)) 3985 return -EINVAL; 3986 if (copy_from_sockptr(&val, optval, sizeof(val))) 3987 return -EFAULT; 3988 3989 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3990 return 0; 3991 } 3992 case PACKET_ORIGDEV: 3993 { 3994 int val; 3995 3996 if (optlen < sizeof(val)) 3997 return -EINVAL; 3998 if (copy_from_sockptr(&val, optval, sizeof(val))) 3999 return -EFAULT; 4000 4001 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 4002 return 0; 4003 } 4004 case PACKET_VNET_HDR: 4005 case PACKET_VNET_HDR_SZ: 4006 { 4007 int val, hdr_len; 4008 4009 if (sock->type != SOCK_RAW) 4010 return -EINVAL; 4011 if (optlen < sizeof(val)) 4012 return -EINVAL; 4013 if (copy_from_sockptr(&val, optval, sizeof(val))) 4014 return -EFAULT; 4015 4016 if (optname == PACKET_VNET_HDR_SZ) { 4017 if (val && val != sizeof(struct virtio_net_hdr) && 4018 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 4019 return -EINVAL; 4020 hdr_len = val; 4021 } else { 4022 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 4023 } 4024 lock_sock(sk); 4025 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 4026 ret = -EBUSY; 4027 } else { 4028 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 4029 ret = 0; 4030 } 4031 release_sock(sk); 4032 return ret; 4033 } 4034 case PACKET_TIMESTAMP: 4035 { 4036 int val; 4037 4038 if (optlen != sizeof(val)) 4039 return -EINVAL; 4040 if (copy_from_sockptr(&val, optval, sizeof(val))) 4041 return -EFAULT; 4042 4043 WRITE_ONCE(po->tp_tstamp, val); 4044 return 0; 4045 } 4046 case PACKET_FANOUT: 4047 { 4048 struct fanout_args args = { 0 }; 4049 4050 if (optlen != sizeof(int) && optlen != sizeof(args)) 4051 return -EINVAL; 4052 if (copy_from_sockptr(&args, optval, optlen)) 4053 return -EFAULT; 4054 4055 return fanout_add(sk, &args); 4056 } 4057 case PACKET_FANOUT_DATA: 4058 { 4059 /* Paired with the WRITE_ONCE() in fanout_add() */ 4060 if (!READ_ONCE(po->fanout)) 4061 return -EINVAL; 4062 4063 return fanout_set_data(po, optval, optlen); 4064 } 4065 case PACKET_IGNORE_OUTGOING: 4066 { 4067 int val; 4068 4069 if (optlen != sizeof(val)) 4070 return -EINVAL; 4071 if (copy_from_sockptr(&val, optval, sizeof(val))) 4072 return -EFAULT; 4073 if (val < 0 || val > 1) 4074 return -EINVAL; 4075 4076 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4077 return 0; 4078 } 4079 case PACKET_TX_HAS_OFF: 4080 { 4081 unsigned int val; 4082 4083 if (optlen != sizeof(val)) 4084 return -EINVAL; 4085 if (copy_from_sockptr(&val, optval, sizeof(val))) 4086 return -EFAULT; 4087 4088 lock_sock(sk); 4089 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4090 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4091 4092 release_sock(sk); 4093 return 0; 4094 } 4095 case PACKET_QDISC_BYPASS: 4096 { 4097 int val; 4098 4099 if (optlen != sizeof(val)) 4100 return -EINVAL; 4101 if (copy_from_sockptr(&val, optval, sizeof(val))) 4102 return -EFAULT; 4103 4104 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4105 return 0; 4106 } 4107 default: 4108 return -ENOPROTOOPT; 4109 } 4110 } 4111 4112 static int packet_getsockopt(struct socket *sock, int level, int optname, 4113 char __user *optval, int __user *optlen) 4114 { 4115 int len; 4116 int val, lv = sizeof(val); 4117 struct sock *sk = sock->sk; 4118 struct packet_sock *po = pkt_sk(sk); 4119 void *data = &val; 4120 union tpacket_stats_u st; 4121 struct tpacket_rollover_stats rstats; 4122 int drops; 4123 4124 if (level != SOL_PACKET) 4125 return -ENOPROTOOPT; 4126 4127 if (get_user(len, optlen)) 4128 return -EFAULT; 4129 4130 if (len < 0) 4131 return -EINVAL; 4132 4133 switch (optname) { 4134 case PACKET_STATISTICS: 4135 spin_lock_bh(&sk->sk_receive_queue.lock); 4136 memcpy(&st, &po->stats, sizeof(st)); 4137 memset(&po->stats, 0, sizeof(po->stats)); 4138 spin_unlock_bh(&sk->sk_receive_queue.lock); 4139 drops = atomic_xchg(&po->tp_drops, 0); 4140 4141 if (po->tp_version == TPACKET_V3) { 4142 lv = sizeof(struct tpacket_stats_v3); 4143 st.stats3.tp_drops = drops; 4144 st.stats3.tp_packets += drops; 4145 data = &st.stats3; 4146 } else { 4147 lv = sizeof(struct tpacket_stats); 4148 st.stats1.tp_drops = drops; 4149 st.stats1.tp_packets += drops; 4150 data = &st.stats1; 4151 } 4152 4153 break; 4154 case PACKET_AUXDATA: 4155 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4156 break; 4157 case PACKET_ORIGDEV: 4158 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4159 break; 4160 case PACKET_VNET_HDR: 4161 val = !!READ_ONCE(po->vnet_hdr_sz); 4162 break; 4163 case PACKET_VNET_HDR_SZ: 4164 val = READ_ONCE(po->vnet_hdr_sz); 4165 break; 4166 case PACKET_VERSION: 4167 val = po->tp_version; 4168 break; 4169 case PACKET_HDRLEN: 4170 if (len > sizeof(int)) 4171 len = sizeof(int); 4172 if (len < sizeof(int)) 4173 return -EINVAL; 4174 if (copy_from_user(&val, optval, len)) 4175 return -EFAULT; 4176 switch (val) { 4177 case TPACKET_V1: 4178 val = sizeof(struct tpacket_hdr); 4179 break; 4180 case TPACKET_V2: 4181 val = sizeof(struct tpacket2_hdr); 4182 break; 4183 case TPACKET_V3: 4184 val = sizeof(struct tpacket3_hdr); 4185 break; 4186 default: 4187 return -EINVAL; 4188 } 4189 break; 4190 case PACKET_RESERVE: 4191 val = po->tp_reserve; 4192 break; 4193 case PACKET_LOSS: 4194 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4195 break; 4196 case PACKET_TIMESTAMP: 4197 val = READ_ONCE(po->tp_tstamp); 4198 break; 4199 case PACKET_FANOUT: 4200 val = (po->fanout ? 4201 ((u32)po->fanout->id | 4202 ((u32)po->fanout->type << 16) | 4203 ((u32)po->fanout->flags << 24)) : 4204 0); 4205 break; 4206 case PACKET_IGNORE_OUTGOING: 4207 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4208 break; 4209 case PACKET_ROLLOVER_STATS: 4210 if (!po->rollover) 4211 return -EINVAL; 4212 rstats.tp_all = atomic_long_read(&po->rollover->num); 4213 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4214 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4215 data = &rstats; 4216 lv = sizeof(rstats); 4217 break; 4218 case PACKET_TX_HAS_OFF: 4219 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4220 break; 4221 case PACKET_QDISC_BYPASS: 4222 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4223 break; 4224 default: 4225 return -ENOPROTOOPT; 4226 } 4227 4228 if (len > lv) 4229 len = lv; 4230 if (put_user(len, optlen)) 4231 return -EFAULT; 4232 if (copy_to_user(optval, data, len)) 4233 return -EFAULT; 4234 return 0; 4235 } 4236 4237 static int packet_notifier(struct notifier_block *this, 4238 unsigned long msg, void *ptr) 4239 { 4240 struct sock *sk; 4241 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4242 struct net *net = dev_net(dev); 4243 4244 rcu_read_lock(); 4245 sk_for_each_rcu(sk, &net->packet.sklist) { 4246 struct packet_sock *po = pkt_sk(sk); 4247 4248 switch (msg) { 4249 case NETDEV_UNREGISTER: 4250 if (po->mclist) 4251 packet_dev_mclist_delete(dev, &po->mclist); 4252 fallthrough; 4253 4254 case NETDEV_DOWN: 4255 if (dev->ifindex == po->ifindex) { 4256 spin_lock(&po->bind_lock); 4257 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4258 __unregister_prot_hook(sk, false); 4259 sk->sk_err = ENETDOWN; 4260 if (!sock_flag(sk, SOCK_DEAD)) 4261 sk_error_report(sk); 4262 } 4263 if (msg == NETDEV_UNREGISTER) { 4264 packet_cached_dev_reset(po); 4265 WRITE_ONCE(po->ifindex, -1); 4266 netdev_put(po->prot_hook.dev, 4267 &po->prot_hook.dev_tracker); 4268 po->prot_hook.dev = NULL; 4269 } 4270 spin_unlock(&po->bind_lock); 4271 } 4272 break; 4273 case NETDEV_UP: 4274 if (dev->ifindex == po->ifindex) { 4275 spin_lock(&po->bind_lock); 4276 if (po->num) 4277 register_prot_hook(sk); 4278 spin_unlock(&po->bind_lock); 4279 } 4280 break; 4281 } 4282 } 4283 rcu_read_unlock(); 4284 return NOTIFY_DONE; 4285 } 4286 4287 4288 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4289 unsigned long arg) 4290 { 4291 struct sock *sk = sock->sk; 4292 4293 switch (cmd) { 4294 case SIOCOUTQ: 4295 { 4296 int amount = sk_wmem_alloc_get(sk); 4297 4298 return put_user(amount, (int __user *)arg); 4299 } 4300 case SIOCINQ: 4301 { 4302 struct sk_buff *skb; 4303 int amount = 0; 4304 4305 spin_lock_bh(&sk->sk_receive_queue.lock); 4306 skb = skb_peek(&sk->sk_receive_queue); 4307 if (skb) 4308 amount = skb->len; 4309 spin_unlock_bh(&sk->sk_receive_queue.lock); 4310 return put_user(amount, (int __user *)arg); 4311 } 4312 #ifdef CONFIG_INET 4313 case SIOCADDRT: 4314 case SIOCDELRT: 4315 case SIOCDARP: 4316 case SIOCGARP: 4317 case SIOCSARP: 4318 case SIOCGIFADDR: 4319 case SIOCSIFADDR: 4320 case SIOCGIFBRDADDR: 4321 case SIOCSIFBRDADDR: 4322 case SIOCGIFNETMASK: 4323 case SIOCSIFNETMASK: 4324 case SIOCGIFDSTADDR: 4325 case SIOCSIFDSTADDR: 4326 case SIOCSIFFLAGS: 4327 return inet_dgram_ops.ioctl(sock, cmd, arg); 4328 #endif 4329 4330 default: 4331 return -ENOIOCTLCMD; 4332 } 4333 return 0; 4334 } 4335 4336 static __poll_t packet_poll(struct file *file, struct socket *sock, 4337 poll_table *wait) 4338 { 4339 struct sock *sk = sock->sk; 4340 struct packet_sock *po = pkt_sk(sk); 4341 __poll_t mask = datagram_poll(file, sock, wait); 4342 4343 spin_lock_bh(&sk->sk_receive_queue.lock); 4344 if (po->rx_ring.pg_vec) { 4345 if (!packet_previous_rx_frame(po, &po->rx_ring, 4346 TP_STATUS_KERNEL)) 4347 mask |= EPOLLIN | EPOLLRDNORM; 4348 } 4349 packet_rcv_try_clear_pressure(po); 4350 spin_unlock_bh(&sk->sk_receive_queue.lock); 4351 spin_lock_bh(&sk->sk_write_queue.lock); 4352 if (po->tx_ring.pg_vec) { 4353 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4354 mask |= EPOLLOUT | EPOLLWRNORM; 4355 } 4356 spin_unlock_bh(&sk->sk_write_queue.lock); 4357 return mask; 4358 } 4359 4360 4361 /* Dirty? Well, I still did not learn better way to account 4362 * for user mmaps. 4363 */ 4364 4365 static void packet_mm_open(struct vm_area_struct *vma) 4366 { 4367 struct file *file = vma->vm_file; 4368 struct socket *sock = file->private_data; 4369 struct sock *sk = sock->sk; 4370 4371 if (sk) 4372 atomic_long_inc(&pkt_sk(sk)->mapped); 4373 } 4374 4375 static void packet_mm_close(struct vm_area_struct *vma) 4376 { 4377 struct file *file = vma->vm_file; 4378 struct socket *sock = file->private_data; 4379 struct sock *sk = sock->sk; 4380 4381 if (sk) 4382 atomic_long_dec(&pkt_sk(sk)->mapped); 4383 } 4384 4385 static const struct vm_operations_struct packet_mmap_ops = { 4386 .open = packet_mm_open, 4387 .close = packet_mm_close, 4388 }; 4389 4390 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4391 unsigned int len) 4392 { 4393 int i; 4394 4395 for (i = 0; i < len; i++) { 4396 if (likely(pg_vec[i].buffer)) { 4397 if (is_vmalloc_addr(pg_vec[i].buffer)) 4398 vfree(pg_vec[i].buffer); 4399 else 4400 free_pages((unsigned long)pg_vec[i].buffer, 4401 order); 4402 pg_vec[i].buffer = NULL; 4403 } 4404 } 4405 kfree(pg_vec); 4406 } 4407 4408 static char *alloc_one_pg_vec_page(unsigned long order) 4409 { 4410 char *buffer; 4411 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4412 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4413 4414 buffer = (char *) __get_free_pages(gfp_flags, order); 4415 if (buffer) 4416 return buffer; 4417 4418 /* __get_free_pages failed, fall back to vmalloc */ 4419 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4420 if (buffer) 4421 return buffer; 4422 4423 /* vmalloc failed, lets dig into swap here */ 4424 gfp_flags &= ~__GFP_NORETRY; 4425 buffer = (char *) __get_free_pages(gfp_flags, order); 4426 if (buffer) 4427 return buffer; 4428 4429 /* complete and utter failure */ 4430 return NULL; 4431 } 4432 4433 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4434 { 4435 unsigned int block_nr = req->tp_block_nr; 4436 struct pgv *pg_vec; 4437 int i; 4438 4439 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN); 4440 if (unlikely(!pg_vec)) 4441 goto out; 4442 4443 for (i = 0; i < block_nr; i++) { 4444 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4445 if (unlikely(!pg_vec[i].buffer)) 4446 goto out_free_pgvec; 4447 } 4448 4449 out: 4450 return pg_vec; 4451 4452 out_free_pgvec: 4453 free_pg_vec(pg_vec, order, block_nr); 4454 pg_vec = NULL; 4455 goto out; 4456 } 4457 4458 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4459 int closing, int tx_ring) 4460 { 4461 struct pgv *pg_vec = NULL; 4462 struct packet_sock *po = pkt_sk(sk); 4463 unsigned long *rx_owner_map = NULL; 4464 int was_running, order = 0; 4465 struct packet_ring_buffer *rb; 4466 struct sk_buff_head *rb_queue; 4467 __be16 num; 4468 int err; 4469 /* Added to avoid minimal code churn */ 4470 struct tpacket_req *req = &req_u->req; 4471 4472 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4473 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4474 4475 err = -EBUSY; 4476 if (!closing) { 4477 if (atomic_long_read(&po->mapped)) 4478 goto out; 4479 if (packet_read_pending(rb)) 4480 goto out; 4481 } 4482 4483 if (req->tp_block_nr) { 4484 unsigned int min_frame_size; 4485 4486 /* Sanity tests and some calculations */ 4487 err = -EBUSY; 4488 if (unlikely(rb->pg_vec)) 4489 goto out; 4490 4491 switch (po->tp_version) { 4492 case TPACKET_V1: 4493 po->tp_hdrlen = TPACKET_HDRLEN; 4494 break; 4495 case TPACKET_V2: 4496 po->tp_hdrlen = TPACKET2_HDRLEN; 4497 break; 4498 case TPACKET_V3: 4499 po->tp_hdrlen = TPACKET3_HDRLEN; 4500 break; 4501 } 4502 4503 err = -EINVAL; 4504 if (unlikely((int)req->tp_block_size <= 0)) 4505 goto out; 4506 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4507 goto out; 4508 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4509 if (po->tp_version >= TPACKET_V3 && 4510 req->tp_block_size < 4511 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4512 goto out; 4513 if (unlikely(req->tp_frame_size < min_frame_size)) 4514 goto out; 4515 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4516 goto out; 4517 4518 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4519 if (unlikely(rb->frames_per_block == 0)) 4520 goto out; 4521 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4522 goto out; 4523 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4524 req->tp_frame_nr)) 4525 goto out; 4526 4527 err = -ENOMEM; 4528 order = get_order(req->tp_block_size); 4529 pg_vec = alloc_pg_vec(req, order); 4530 if (unlikely(!pg_vec)) 4531 goto out; 4532 switch (po->tp_version) { 4533 case TPACKET_V3: 4534 /* Block transmit is not supported yet */ 4535 if (!tx_ring) { 4536 init_prb_bdqc(po, rb, pg_vec, req_u); 4537 } else { 4538 struct tpacket_req3 *req3 = &req_u->req3; 4539 4540 if (req3->tp_retire_blk_tov || 4541 req3->tp_sizeof_priv || 4542 req3->tp_feature_req_word) { 4543 err = -EINVAL; 4544 goto out_free_pg_vec; 4545 } 4546 } 4547 break; 4548 default: 4549 if (!tx_ring) { 4550 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4551 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4552 if (!rx_owner_map) 4553 goto out_free_pg_vec; 4554 } 4555 break; 4556 } 4557 } 4558 /* Done */ 4559 else { 4560 err = -EINVAL; 4561 if (unlikely(req->tp_frame_nr)) 4562 goto out; 4563 } 4564 4565 4566 /* Detach socket from network */ 4567 spin_lock(&po->bind_lock); 4568 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4569 num = po->num; 4570 if (was_running) { 4571 WRITE_ONCE(po->num, 0); 4572 __unregister_prot_hook(sk, false); 4573 } 4574 spin_unlock(&po->bind_lock); 4575 4576 synchronize_net(); 4577 4578 err = -EBUSY; 4579 mutex_lock(&po->pg_vec_lock); 4580 if (closing || atomic_long_read(&po->mapped) == 0) { 4581 err = 0; 4582 spin_lock_bh(&rb_queue->lock); 4583 swap(rb->pg_vec, pg_vec); 4584 if (po->tp_version <= TPACKET_V2) 4585 swap(rb->rx_owner_map, rx_owner_map); 4586 rb->frame_max = (req->tp_frame_nr - 1); 4587 rb->head = 0; 4588 rb->frame_size = req->tp_frame_size; 4589 spin_unlock_bh(&rb_queue->lock); 4590 4591 swap(rb->pg_vec_order, order); 4592 swap(rb->pg_vec_len, req->tp_block_nr); 4593 4594 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4595 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4596 tpacket_rcv : packet_rcv; 4597 skb_queue_purge(rb_queue); 4598 if (atomic_long_read(&po->mapped)) 4599 pr_err("packet_mmap: vma is busy: %ld\n", 4600 atomic_long_read(&po->mapped)); 4601 } 4602 mutex_unlock(&po->pg_vec_lock); 4603 4604 spin_lock(&po->bind_lock); 4605 if (was_running) { 4606 WRITE_ONCE(po->num, num); 4607 register_prot_hook(sk); 4608 } 4609 spin_unlock(&po->bind_lock); 4610 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4611 /* Because we don't support block-based V3 on tx-ring */ 4612 if (!tx_ring) 4613 prb_shutdown_retire_blk_timer(po, rb_queue); 4614 } 4615 4616 out_free_pg_vec: 4617 if (pg_vec) { 4618 bitmap_free(rx_owner_map); 4619 free_pg_vec(pg_vec, order, req->tp_block_nr); 4620 } 4621 out: 4622 return err; 4623 } 4624 4625 static int packet_mmap(struct file *file, struct socket *sock, 4626 struct vm_area_struct *vma) 4627 { 4628 struct sock *sk = sock->sk; 4629 struct packet_sock *po = pkt_sk(sk); 4630 unsigned long size, expected_size; 4631 struct packet_ring_buffer *rb; 4632 unsigned long start; 4633 int err = -EINVAL; 4634 int i; 4635 4636 if (vma->vm_pgoff) 4637 return -EINVAL; 4638 4639 mutex_lock(&po->pg_vec_lock); 4640 4641 expected_size = 0; 4642 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4643 if (rb->pg_vec) { 4644 expected_size += rb->pg_vec_len 4645 * rb->pg_vec_pages 4646 * PAGE_SIZE; 4647 } 4648 } 4649 4650 if (expected_size == 0) 4651 goto out; 4652 4653 size = vma->vm_end - vma->vm_start; 4654 if (size != expected_size) 4655 goto out; 4656 4657 start = vma->vm_start; 4658 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4659 if (rb->pg_vec == NULL) 4660 continue; 4661 4662 for (i = 0; i < rb->pg_vec_len; i++) { 4663 struct page *page; 4664 void *kaddr = rb->pg_vec[i].buffer; 4665 int pg_num; 4666 4667 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4668 page = pgv_to_page(kaddr); 4669 err = vm_insert_page(vma, start, page); 4670 if (unlikely(err)) 4671 goto out; 4672 start += PAGE_SIZE; 4673 kaddr += PAGE_SIZE; 4674 } 4675 } 4676 } 4677 4678 atomic_long_inc(&po->mapped); 4679 vma->vm_ops = &packet_mmap_ops; 4680 err = 0; 4681 4682 out: 4683 mutex_unlock(&po->pg_vec_lock); 4684 return err; 4685 } 4686 4687 static const struct proto_ops packet_ops_spkt = { 4688 .family = PF_PACKET, 4689 .owner = THIS_MODULE, 4690 .release = packet_release, 4691 .bind = packet_bind_spkt, 4692 .connect = sock_no_connect, 4693 .socketpair = sock_no_socketpair, 4694 .accept = sock_no_accept, 4695 .getname = packet_getname_spkt, 4696 .poll = datagram_poll, 4697 .ioctl = packet_ioctl, 4698 .gettstamp = sock_gettstamp, 4699 .listen = sock_no_listen, 4700 .shutdown = sock_no_shutdown, 4701 .sendmsg = packet_sendmsg_spkt, 4702 .recvmsg = packet_recvmsg, 4703 .mmap = sock_no_mmap, 4704 }; 4705 4706 static const struct proto_ops packet_ops = { 4707 .family = PF_PACKET, 4708 .owner = THIS_MODULE, 4709 .release = packet_release, 4710 .bind = packet_bind, 4711 .connect = sock_no_connect, 4712 .socketpair = sock_no_socketpair, 4713 .accept = sock_no_accept, 4714 .getname = packet_getname, 4715 .poll = packet_poll, 4716 .ioctl = packet_ioctl, 4717 .gettstamp = sock_gettstamp, 4718 .listen = sock_no_listen, 4719 .shutdown = sock_no_shutdown, 4720 .setsockopt = packet_setsockopt, 4721 .getsockopt = packet_getsockopt, 4722 .sendmsg = packet_sendmsg, 4723 .recvmsg = packet_recvmsg, 4724 .mmap = packet_mmap, 4725 }; 4726 4727 static const struct net_proto_family packet_family_ops = { 4728 .family = PF_PACKET, 4729 .create = packet_create, 4730 .owner = THIS_MODULE, 4731 }; 4732 4733 static struct notifier_block packet_netdev_notifier = { 4734 .notifier_call = packet_notifier, 4735 }; 4736 4737 #ifdef CONFIG_PROC_FS 4738 4739 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4740 __acquires(RCU) 4741 { 4742 struct net *net = seq_file_net(seq); 4743 4744 rcu_read_lock(); 4745 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4746 } 4747 4748 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4749 { 4750 struct net *net = seq_file_net(seq); 4751 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4752 } 4753 4754 static void packet_seq_stop(struct seq_file *seq, void *v) 4755 __releases(RCU) 4756 { 4757 rcu_read_unlock(); 4758 } 4759 4760 static int packet_seq_show(struct seq_file *seq, void *v) 4761 { 4762 if (v == SEQ_START_TOKEN) 4763 seq_printf(seq, 4764 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4765 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4766 else { 4767 struct sock *s = sk_entry(v); 4768 const struct packet_sock *po = pkt_sk(s); 4769 4770 seq_printf(seq, 4771 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4772 s, 4773 refcount_read(&s->sk_refcnt), 4774 s->sk_type, 4775 ntohs(READ_ONCE(po->num)), 4776 READ_ONCE(po->ifindex), 4777 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4778 atomic_read(&s->sk_rmem_alloc), 4779 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4780 sock_i_ino(s)); 4781 } 4782 4783 return 0; 4784 } 4785 4786 static const struct seq_operations packet_seq_ops = { 4787 .start = packet_seq_start, 4788 .next = packet_seq_next, 4789 .stop = packet_seq_stop, 4790 .show = packet_seq_show, 4791 }; 4792 #endif 4793 4794 static int __net_init packet_net_init(struct net *net) 4795 { 4796 mutex_init(&net->packet.sklist_lock); 4797 INIT_HLIST_HEAD(&net->packet.sklist); 4798 4799 #ifdef CONFIG_PROC_FS 4800 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4801 sizeof(struct seq_net_private))) 4802 return -ENOMEM; 4803 #endif /* CONFIG_PROC_FS */ 4804 4805 return 0; 4806 } 4807 4808 static void __net_exit packet_net_exit(struct net *net) 4809 { 4810 remove_proc_entry("packet", net->proc_net); 4811 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4812 } 4813 4814 static struct pernet_operations packet_net_ops = { 4815 .init = packet_net_init, 4816 .exit = packet_net_exit, 4817 }; 4818 4819 4820 static void __exit packet_exit(void) 4821 { 4822 sock_unregister(PF_PACKET); 4823 proto_unregister(&packet_proto); 4824 unregister_netdevice_notifier(&packet_netdev_notifier); 4825 unregister_pernet_subsys(&packet_net_ops); 4826 } 4827 4828 static int __init packet_init(void) 4829 { 4830 int rc; 4831 4832 rc = register_pernet_subsys(&packet_net_ops); 4833 if (rc) 4834 goto out; 4835 rc = register_netdevice_notifier(&packet_netdev_notifier); 4836 if (rc) 4837 goto out_pernet; 4838 rc = proto_register(&packet_proto, 0); 4839 if (rc) 4840 goto out_notifier; 4841 rc = sock_register(&packet_family_ops); 4842 if (rc) 4843 goto out_proto; 4844 4845 return 0; 4846 4847 out_proto: 4848 proto_unregister(&packet_proto); 4849 out_notifier: 4850 unregister_netdevice_notifier(&packet_netdev_notifier); 4851 out_pernet: 4852 unregister_pernet_subsys(&packet_net_ops); 4853 out: 4854 return rc; 4855 } 4856 4857 module_init(packet_init); 4858 module_exit(packet_exit); 4859 MODULE_LICENSE("GPL"); 4860 MODULE_ALIAS_NETPROTO(PF_PACKET); 4861