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 (po->num && 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 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1842 WRITE_ONCE(po->fanout, match); 1843 1844 po->rollover = rollover; 1845 rollover = NULL; 1846 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1847 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 1848 __dev_remove_pack(&po->prot_hook); 1849 __fanout_link(sk, po); 1850 } 1851 err = 0; 1852 } 1853 } 1854 spin_unlock(&po->bind_lock); 1855 1856 if (err && !refcount_read(&match->sk_ref)) { 1857 list_del(&match->list); 1858 kvfree(match); 1859 } 1860 1861 out: 1862 kfree(rollover); 1863 mutex_unlock(&fanout_mutex); 1864 return err; 1865 } 1866 1867 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1868 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1869 * It is the responsibility of the caller to call fanout_release_data() and 1870 * free the returned packet_fanout (after synchronize_net()) 1871 */ 1872 static struct packet_fanout *fanout_release(struct sock *sk) 1873 { 1874 struct packet_sock *po = pkt_sk(sk); 1875 struct packet_fanout *f; 1876 1877 mutex_lock(&fanout_mutex); 1878 f = po->fanout; 1879 if (f) { 1880 po->fanout = NULL; 1881 1882 if (refcount_dec_and_test(&f->sk_ref)) 1883 list_del(&f->list); 1884 else 1885 f = NULL; 1886 } 1887 mutex_unlock(&fanout_mutex); 1888 1889 return f; 1890 } 1891 1892 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1893 struct sk_buff *skb) 1894 { 1895 /* Earlier code assumed this would be a VLAN pkt, double-check 1896 * this now that we have the actual packet in hand. We can only 1897 * do this check on Ethernet devices. 1898 */ 1899 if (unlikely(dev->type != ARPHRD_ETHER)) 1900 return false; 1901 1902 skb_reset_mac_header(skb); 1903 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1904 } 1905 1906 static const struct proto_ops packet_ops; 1907 1908 static const struct proto_ops packet_ops_spkt; 1909 1910 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1911 struct packet_type *pt, struct net_device *orig_dev) 1912 { 1913 struct sock *sk; 1914 struct sockaddr_pkt *spkt; 1915 1916 /* 1917 * When we registered the protocol we saved the socket in the data 1918 * field for just this event. 1919 */ 1920 1921 sk = pt->af_packet_priv; 1922 1923 /* 1924 * Yank back the headers [hope the device set this 1925 * right or kerboom...] 1926 * 1927 * Incoming packets have ll header pulled, 1928 * push it back. 1929 * 1930 * For outgoing ones skb->data == skb_mac_header(skb) 1931 * so that this procedure is noop. 1932 */ 1933 1934 if (skb->pkt_type == PACKET_LOOPBACK) 1935 goto out; 1936 1937 if (!net_eq(dev_net(dev), sock_net(sk))) 1938 goto out; 1939 1940 skb = skb_share_check(skb, GFP_ATOMIC); 1941 if (skb == NULL) 1942 goto oom; 1943 1944 /* drop any routing info */ 1945 skb_dst_drop(skb); 1946 1947 /* drop conntrack reference */ 1948 nf_reset_ct(skb); 1949 1950 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1951 1952 skb_push(skb, skb->data - skb_mac_header(skb)); 1953 1954 /* 1955 * The SOCK_PACKET socket receives _all_ frames. 1956 */ 1957 1958 spkt->spkt_family = dev->type; 1959 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1960 spkt->spkt_protocol = skb->protocol; 1961 1962 /* 1963 * Charge the memory to the socket. This is done specifically 1964 * to prevent sockets using all the memory up. 1965 */ 1966 1967 if (sock_queue_rcv_skb(sk, skb) == 0) 1968 return 0; 1969 1970 out: 1971 kfree_skb(skb); 1972 oom: 1973 return 0; 1974 } 1975 1976 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1977 { 1978 int depth; 1979 1980 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1981 sock->type == SOCK_RAW) { 1982 skb_reset_mac_header(skb); 1983 skb->protocol = dev_parse_header_protocol(skb); 1984 } 1985 1986 /* Move network header to the right position for VLAN tagged packets */ 1987 if (likely(skb->dev->type == ARPHRD_ETHER) && 1988 eth_type_vlan(skb->protocol) && 1989 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 1990 skb_set_network_header(skb, depth); 1991 1992 skb_probe_transport_header(skb); 1993 } 1994 1995 /* 1996 * Output a raw packet to a device layer. This bypasses all the other 1997 * protocol layers and you must therefore supply it with a complete frame 1998 */ 1999 2000 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 2001 size_t len) 2002 { 2003 struct sock *sk = sock->sk; 2004 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 2005 struct sk_buff *skb = NULL; 2006 struct net_device *dev; 2007 struct sockcm_cookie sockc; 2008 __be16 proto = 0; 2009 int err; 2010 int extra_len = 0; 2011 2012 /* 2013 * Get and verify the address. 2014 */ 2015 2016 if (saddr) { 2017 if (msg->msg_namelen < sizeof(struct sockaddr)) 2018 return -EINVAL; 2019 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 2020 proto = saddr->spkt_protocol; 2021 } else 2022 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 2023 2024 /* 2025 * Find the device first to size check it 2026 */ 2027 2028 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 2029 retry: 2030 rcu_read_lock(); 2031 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 2032 err = -ENODEV; 2033 if (dev == NULL) 2034 goto out_unlock; 2035 2036 err = -ENETDOWN; 2037 if (!(dev->flags & IFF_UP)) 2038 goto out_unlock; 2039 2040 /* 2041 * You may not queue a frame bigger than the mtu. This is the lowest level 2042 * raw protocol and you must do your own fragmentation at this level. 2043 */ 2044 2045 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2046 if (!netif_supports_nofcs(dev)) { 2047 err = -EPROTONOSUPPORT; 2048 goto out_unlock; 2049 } 2050 extra_len = 4; /* We're doing our own CRC */ 2051 } 2052 2053 err = -EMSGSIZE; 2054 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 2055 goto out_unlock; 2056 2057 if (!skb) { 2058 size_t reserved = LL_RESERVED_SPACE(dev); 2059 int tlen = dev->needed_tailroom; 2060 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 2061 2062 rcu_read_unlock(); 2063 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2064 if (skb == NULL) 2065 return -ENOBUFS; 2066 /* FIXME: Save some space for broken drivers that write a hard 2067 * header at transmission time by themselves. PPP is the notable 2068 * one here. This should really be fixed at the driver level. 2069 */ 2070 skb_reserve(skb, reserved); 2071 skb_reset_network_header(skb); 2072 2073 /* Try to align data part correctly */ 2074 if (hhlen) { 2075 skb->data -= hhlen; 2076 skb->tail -= hhlen; 2077 if (len < hhlen) 2078 skb_reset_network_header(skb); 2079 } 2080 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2081 if (err) 2082 goto out_free; 2083 goto retry; 2084 } 2085 2086 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2087 err = -EINVAL; 2088 goto out_unlock; 2089 } 2090 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 2091 !packet_extra_vlan_len_allowed(dev, skb)) { 2092 err = -EMSGSIZE; 2093 goto out_unlock; 2094 } 2095 2096 sockcm_init(&sockc, sk); 2097 if (msg->msg_controllen) { 2098 err = sock_cmsg_send(sk, msg, &sockc); 2099 if (unlikely(err)) 2100 goto out_unlock; 2101 } 2102 2103 skb->protocol = proto; 2104 skb->dev = dev; 2105 skb->priority = sockc.priority; 2106 skb->mark = sockc.mark; 2107 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2108 skb_setup_tx_timestamp(skb, &sockc); 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 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2172 struct sock *sk = NULL; 2173 struct sockaddr_ll *sll; 2174 struct packet_sock *po; 2175 u8 *skb_head = skb->data; 2176 int skb_len = skb->len; 2177 unsigned int snaplen, res; 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_frags_readable(skb) ? skb->len : skb_headlen(skb); 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 atomic_inc(&po->tp_drops); 2268 atomic_inc(&sk->sk_drops); 2269 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 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 sk_skb_reason_drop(sk, skb, drop_reason); 2278 return 0; 2279 } 2280 2281 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2282 struct packet_type *pt, struct net_device *orig_dev) 2283 { 2284 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2285 struct sock *sk = NULL; 2286 struct packet_sock *po; 2287 struct sockaddr_ll *sll; 2288 union tpacket_uhdr h; 2289 u8 *skb_head = skb->data; 2290 int skb_len = skb->len; 2291 unsigned int snaplen, res; 2292 unsigned long status = TP_STATUS_USER; 2293 unsigned short macoff, hdrlen; 2294 unsigned int netoff; 2295 struct sk_buff *copy_skb = NULL; 2296 struct timespec64 ts; 2297 __u32 ts_status; 2298 unsigned int slot_id = 0; 2299 int vnet_hdr_sz = 0; 2300 2301 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2302 * We may add members to them until current aligned size without forcing 2303 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2304 */ 2305 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2306 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2307 2308 if (skb->pkt_type == PACKET_LOOPBACK) 2309 goto drop; 2310 2311 sk = pt->af_packet_priv; 2312 po = pkt_sk(sk); 2313 2314 if (!net_eq(dev_net(dev), sock_net(sk))) 2315 goto drop; 2316 2317 if (dev_has_header(dev)) { 2318 if (sk->sk_type != SOCK_DGRAM) 2319 skb_push(skb, skb->data - skb_mac_header(skb)); 2320 else if (skb->pkt_type == PACKET_OUTGOING) { 2321 /* Special case: outgoing packets have ll header at head */ 2322 skb_pull(skb, skb_network_offset(skb)); 2323 } 2324 } 2325 2326 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2327 2328 res = run_filter(skb, sk, snaplen); 2329 if (!res) 2330 goto drop_n_restore; 2331 2332 /* If we are flooded, just give up */ 2333 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2334 atomic_inc(&po->tp_drops); 2335 goto drop_n_restore; 2336 } 2337 2338 if (skb->ip_summed == CHECKSUM_PARTIAL) 2339 status |= TP_STATUS_CSUMNOTREADY; 2340 else if (skb->pkt_type != PACKET_OUTGOING && 2341 skb_csum_unnecessary(skb)) 2342 status |= TP_STATUS_CSUM_VALID; 2343 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2344 status |= TP_STATUS_GSO_TCP; 2345 2346 if (snaplen > res) 2347 snaplen = res; 2348 2349 if (sk->sk_type == SOCK_DGRAM) { 2350 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2351 po->tp_reserve; 2352 } else { 2353 unsigned int maclen = skb_network_offset(skb); 2354 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2355 (maclen < 16 ? 16 : maclen)) + 2356 po->tp_reserve; 2357 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2358 if (vnet_hdr_sz) 2359 netoff += vnet_hdr_sz; 2360 macoff = netoff - maclen; 2361 } 2362 if (netoff > USHRT_MAX) { 2363 atomic_inc(&po->tp_drops); 2364 goto drop_n_restore; 2365 } 2366 if (po->tp_version <= TPACKET_V2) { 2367 if (macoff + snaplen > po->rx_ring.frame_size) { 2368 if (READ_ONCE(po->copy_thresh) && 2369 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2370 if (skb_shared(skb)) { 2371 copy_skb = skb_clone(skb, GFP_ATOMIC); 2372 } else { 2373 copy_skb = skb_get(skb); 2374 skb_head = skb->data; 2375 } 2376 if (copy_skb) { 2377 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2378 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2379 skb_set_owner_r(copy_skb, sk); 2380 } 2381 } 2382 snaplen = po->rx_ring.frame_size - macoff; 2383 if ((int)snaplen < 0) { 2384 snaplen = 0; 2385 vnet_hdr_sz = 0; 2386 } 2387 } 2388 } else if (unlikely(macoff + snaplen > 2389 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2390 u32 nval; 2391 2392 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2393 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2394 snaplen, nval, macoff); 2395 snaplen = nval; 2396 if (unlikely((int)snaplen < 0)) { 2397 snaplen = 0; 2398 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2399 vnet_hdr_sz = 0; 2400 } 2401 } 2402 spin_lock(&sk->sk_receive_queue.lock); 2403 h.raw = packet_current_rx_frame(po, skb, 2404 TP_STATUS_KERNEL, (macoff+snaplen)); 2405 if (!h.raw) 2406 goto drop_n_account; 2407 2408 if (po->tp_version <= TPACKET_V2) { 2409 slot_id = po->rx_ring.head; 2410 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2411 goto drop_n_account; 2412 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2413 } 2414 2415 if (vnet_hdr_sz && 2416 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2417 sizeof(struct virtio_net_hdr), 2418 vio_le(), true, 0)) { 2419 if (po->tp_version == TPACKET_V3) 2420 prb_clear_blk_fill_status(&po->rx_ring); 2421 goto drop_n_account; 2422 } 2423 2424 if (po->tp_version <= TPACKET_V2) { 2425 packet_increment_rx_head(po, &po->rx_ring); 2426 /* 2427 * LOSING will be reported till you read the stats, 2428 * because it's COR - Clear On Read. 2429 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2430 * at packet level. 2431 */ 2432 if (atomic_read(&po->tp_drops)) 2433 status |= TP_STATUS_LOSING; 2434 } 2435 2436 po->stats.stats1.tp_packets++; 2437 if (copy_skb) { 2438 status |= TP_STATUS_COPY; 2439 skb_clear_delivery_time(copy_skb); 2440 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2441 } 2442 spin_unlock(&sk->sk_receive_queue.lock); 2443 2444 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2445 2446 /* Always timestamp; prefer an existing software timestamp taken 2447 * closer to the time of capture. 2448 */ 2449 ts_status = tpacket_get_timestamp(skb, &ts, 2450 READ_ONCE(po->tp_tstamp) | 2451 SOF_TIMESTAMPING_SOFTWARE); 2452 if (!ts_status) 2453 ktime_get_real_ts64(&ts); 2454 2455 status |= ts_status; 2456 2457 switch (po->tp_version) { 2458 case TPACKET_V1: 2459 h.h1->tp_len = skb->len; 2460 h.h1->tp_snaplen = snaplen; 2461 h.h1->tp_mac = macoff; 2462 h.h1->tp_net = netoff; 2463 h.h1->tp_sec = ts.tv_sec; 2464 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2465 hdrlen = sizeof(*h.h1); 2466 break; 2467 case TPACKET_V2: 2468 h.h2->tp_len = skb->len; 2469 h.h2->tp_snaplen = snaplen; 2470 h.h2->tp_mac = macoff; 2471 h.h2->tp_net = netoff; 2472 h.h2->tp_sec = ts.tv_sec; 2473 h.h2->tp_nsec = ts.tv_nsec; 2474 if (skb_vlan_tag_present(skb)) { 2475 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2476 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2477 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2478 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2479 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2480 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2481 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2482 } else { 2483 h.h2->tp_vlan_tci = 0; 2484 h.h2->tp_vlan_tpid = 0; 2485 } 2486 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2487 hdrlen = sizeof(*h.h2); 2488 break; 2489 case TPACKET_V3: 2490 /* tp_nxt_offset,vlan are already populated above. 2491 * So DONT clear those fields here 2492 */ 2493 h.h3->tp_status |= status; 2494 h.h3->tp_len = skb->len; 2495 h.h3->tp_snaplen = snaplen; 2496 h.h3->tp_mac = macoff; 2497 h.h3->tp_net = netoff; 2498 h.h3->tp_sec = ts.tv_sec; 2499 h.h3->tp_nsec = ts.tv_nsec; 2500 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2501 hdrlen = sizeof(*h.h3); 2502 break; 2503 default: 2504 BUG(); 2505 } 2506 2507 sll = h.raw + TPACKET_ALIGN(hdrlen); 2508 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2509 sll->sll_family = AF_PACKET; 2510 sll->sll_hatype = dev->type; 2511 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2512 vlan_get_protocol_dgram(skb) : skb->protocol; 2513 sll->sll_pkttype = skb->pkt_type; 2514 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2515 sll->sll_ifindex = orig_dev->ifindex; 2516 else 2517 sll->sll_ifindex = dev->ifindex; 2518 2519 smp_mb(); 2520 2521 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2522 if (po->tp_version <= TPACKET_V2) { 2523 u8 *start, *end; 2524 2525 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2526 macoff + snaplen); 2527 2528 for (start = h.raw; start < end; start += PAGE_SIZE) 2529 flush_dcache_page(pgv_to_page(start)); 2530 } 2531 smp_wmb(); 2532 #endif 2533 2534 if (po->tp_version <= TPACKET_V2) { 2535 spin_lock(&sk->sk_receive_queue.lock); 2536 __packet_set_status(po, h.raw, status); 2537 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2538 spin_unlock(&sk->sk_receive_queue.lock); 2539 sk->sk_data_ready(sk); 2540 } else if (po->tp_version == TPACKET_V3) { 2541 prb_clear_blk_fill_status(&po->rx_ring); 2542 } 2543 2544 drop_n_restore: 2545 if (skb_head != skb->data && skb_shared(skb)) { 2546 skb->data = skb_head; 2547 skb->len = skb_len; 2548 } 2549 drop: 2550 sk_skb_reason_drop(sk, skb, drop_reason); 2551 return 0; 2552 2553 drop_n_account: 2554 spin_unlock(&sk->sk_receive_queue.lock); 2555 atomic_inc(&po->tp_drops); 2556 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2557 2558 sk->sk_data_ready(sk); 2559 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2560 goto drop_n_restore; 2561 } 2562 2563 static void tpacket_destruct_skb(struct sk_buff *skb) 2564 { 2565 struct packet_sock *po = pkt_sk(skb->sk); 2566 2567 if (likely(po->tx_ring.pg_vec)) { 2568 void *ph; 2569 __u32 ts; 2570 2571 ph = skb_zcopy_get_nouarg(skb); 2572 packet_dec_pending(&po->tx_ring); 2573 2574 ts = __packet_set_timestamp(po, ph, skb); 2575 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2576 2577 complete(&po->skb_completion); 2578 } 2579 2580 sock_wfree(skb); 2581 } 2582 2583 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2584 { 2585 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2586 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2587 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2588 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2589 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2590 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2591 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2592 2593 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2594 return -EINVAL; 2595 2596 return 0; 2597 } 2598 2599 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2600 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2601 { 2602 int ret; 2603 2604 if (*len < vnet_hdr_sz) 2605 return -EINVAL; 2606 *len -= vnet_hdr_sz; 2607 2608 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2609 return -EFAULT; 2610 2611 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2612 if (ret) 2613 return ret; 2614 2615 /* move iter to point to the start of mac header */ 2616 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2617 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2618 2619 return 0; 2620 } 2621 2622 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2623 void *frame, struct net_device *dev, void *data, int tp_len, 2624 __be16 proto, unsigned char *addr, int hlen, int copylen, 2625 const struct sockcm_cookie *sockc) 2626 { 2627 union tpacket_uhdr ph; 2628 int to_write, offset, len, nr_frags, len_max; 2629 struct socket *sock = po->sk.sk_socket; 2630 struct page *page; 2631 int err; 2632 2633 ph.raw = frame; 2634 2635 skb->protocol = proto; 2636 skb->dev = dev; 2637 skb->priority = sockc->priority; 2638 skb->mark = sockc->mark; 2639 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2640 skb_setup_tx_timestamp(skb, sockc); 2641 skb_zcopy_set_nouarg(skb, ph.raw); 2642 2643 skb_reserve(skb, hlen); 2644 skb_reset_network_header(skb); 2645 2646 to_write = tp_len; 2647 2648 if (sock->type == SOCK_DGRAM) { 2649 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2650 NULL, tp_len); 2651 if (unlikely(err < 0)) 2652 return -EINVAL; 2653 } else if (copylen) { 2654 int hdrlen = min_t(int, copylen, tp_len); 2655 2656 skb_push(skb, dev->hard_header_len); 2657 skb_put(skb, copylen - dev->hard_header_len); 2658 err = skb_store_bits(skb, 0, data, hdrlen); 2659 if (unlikely(err)) 2660 return err; 2661 if (!dev_validate_header(dev, skb->data, hdrlen)) 2662 return -EINVAL; 2663 2664 data += hdrlen; 2665 to_write -= hdrlen; 2666 } 2667 2668 offset = offset_in_page(data); 2669 len_max = PAGE_SIZE - offset; 2670 len = ((to_write > len_max) ? len_max : to_write); 2671 2672 skb->data_len = to_write; 2673 skb->len += to_write; 2674 skb->truesize += to_write; 2675 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2676 2677 while (likely(to_write)) { 2678 nr_frags = skb_shinfo(skb)->nr_frags; 2679 2680 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2681 pr_err("Packet exceed the number of skb frags(%u)\n", 2682 (unsigned int)MAX_SKB_FRAGS); 2683 return -EFAULT; 2684 } 2685 2686 page = pgv_to_page(data); 2687 data += len; 2688 flush_dcache_page(page); 2689 get_page(page); 2690 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2691 to_write -= len; 2692 offset = 0; 2693 len_max = PAGE_SIZE; 2694 len = ((to_write > len_max) ? len_max : to_write); 2695 } 2696 2697 packet_parse_headers(skb, sock); 2698 2699 return tp_len; 2700 } 2701 2702 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2703 int size_max, void **data) 2704 { 2705 union tpacket_uhdr ph; 2706 int tp_len, off; 2707 2708 ph.raw = frame; 2709 2710 switch (po->tp_version) { 2711 case TPACKET_V3: 2712 if (ph.h3->tp_next_offset != 0) { 2713 pr_warn_once("variable sized slot not supported"); 2714 return -EINVAL; 2715 } 2716 tp_len = ph.h3->tp_len; 2717 break; 2718 case TPACKET_V2: 2719 tp_len = ph.h2->tp_len; 2720 break; 2721 default: 2722 tp_len = ph.h1->tp_len; 2723 break; 2724 } 2725 if (unlikely(tp_len > size_max)) { 2726 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2727 return -EMSGSIZE; 2728 } 2729 2730 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2731 int off_min, off_max; 2732 2733 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2734 off_max = po->tx_ring.frame_size - tp_len; 2735 if (po->sk.sk_type == SOCK_DGRAM) { 2736 switch (po->tp_version) { 2737 case TPACKET_V3: 2738 off = ph.h3->tp_net; 2739 break; 2740 case TPACKET_V2: 2741 off = ph.h2->tp_net; 2742 break; 2743 default: 2744 off = ph.h1->tp_net; 2745 break; 2746 } 2747 } else { 2748 switch (po->tp_version) { 2749 case TPACKET_V3: 2750 off = ph.h3->tp_mac; 2751 break; 2752 case TPACKET_V2: 2753 off = ph.h2->tp_mac; 2754 break; 2755 default: 2756 off = ph.h1->tp_mac; 2757 break; 2758 } 2759 } 2760 if (unlikely((off < off_min) || (off_max < off))) 2761 return -EINVAL; 2762 } else { 2763 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2764 } 2765 2766 *data = frame + off; 2767 return tp_len; 2768 } 2769 2770 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2771 { 2772 struct sk_buff *skb = NULL; 2773 struct net_device *dev; 2774 struct virtio_net_hdr *vnet_hdr = NULL; 2775 struct sockcm_cookie sockc; 2776 __be16 proto; 2777 int err, reserve = 0; 2778 void *ph; 2779 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2780 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2781 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2782 unsigned char *addr = NULL; 2783 int tp_len, size_max; 2784 void *data; 2785 int len_sum = 0; 2786 int status = TP_STATUS_AVAILABLE; 2787 int hlen, tlen, copylen = 0; 2788 long timeo = 0; 2789 2790 mutex_lock(&po->pg_vec_lock); 2791 2792 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2793 * we need to confirm it under protection of pg_vec_lock. 2794 */ 2795 if (unlikely(!po->tx_ring.pg_vec)) { 2796 err = -EBUSY; 2797 goto out; 2798 } 2799 if (likely(saddr == NULL)) { 2800 dev = packet_cached_dev_get(po); 2801 proto = READ_ONCE(po->num); 2802 } else { 2803 err = -EINVAL; 2804 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2805 goto out; 2806 if (msg->msg_namelen < (saddr->sll_halen 2807 + offsetof(struct sockaddr_ll, 2808 sll_addr))) 2809 goto out; 2810 proto = saddr->sll_protocol; 2811 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2812 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2813 if (dev && msg->msg_namelen < dev->addr_len + 2814 offsetof(struct sockaddr_ll, sll_addr)) 2815 goto out_put; 2816 addr = saddr->sll_addr; 2817 } 2818 } 2819 2820 err = -ENXIO; 2821 if (unlikely(dev == NULL)) 2822 goto out; 2823 err = -ENETDOWN; 2824 if (unlikely(!(dev->flags & IFF_UP))) 2825 goto out_put; 2826 2827 sockcm_init(&sockc, &po->sk); 2828 if (msg->msg_controllen) { 2829 err = sock_cmsg_send(&po->sk, msg, &sockc); 2830 if (unlikely(err)) 2831 goto out_put; 2832 } 2833 2834 if (po->sk.sk_socket->type == SOCK_RAW) 2835 reserve = dev->hard_header_len; 2836 size_max = po->tx_ring.frame_size 2837 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2838 2839 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2840 size_max = dev->mtu + reserve + VLAN_HLEN; 2841 2842 reinit_completion(&po->skb_completion); 2843 2844 do { 2845 ph = packet_current_frame(po, &po->tx_ring, 2846 TP_STATUS_SEND_REQUEST); 2847 if (unlikely(ph == NULL)) { 2848 if (need_wait && skb) { 2849 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2850 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2851 if (timeo <= 0) { 2852 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2853 goto out_put; 2854 } 2855 } 2856 /* check for additional frames */ 2857 continue; 2858 } 2859 2860 skb = NULL; 2861 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2862 if (tp_len < 0) 2863 goto tpacket_error; 2864 2865 status = TP_STATUS_SEND_REQUEST; 2866 hlen = LL_RESERVED_SPACE(dev); 2867 tlen = dev->needed_tailroom; 2868 if (vnet_hdr_sz) { 2869 vnet_hdr = data; 2870 data += vnet_hdr_sz; 2871 tp_len -= vnet_hdr_sz; 2872 if (tp_len < 0 || 2873 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2874 tp_len = -EINVAL; 2875 goto tpacket_error; 2876 } 2877 copylen = __virtio16_to_cpu(vio_le(), 2878 vnet_hdr->hdr_len); 2879 } 2880 copylen = max_t(int, copylen, dev->hard_header_len); 2881 skb = sock_alloc_send_skb(&po->sk, 2882 hlen + tlen + sizeof(struct sockaddr_ll) + 2883 (copylen - dev->hard_header_len), 2884 !need_wait, &err); 2885 2886 if (unlikely(skb == NULL)) { 2887 /* we assume the socket was initially writeable ... */ 2888 if (likely(len_sum > 0)) 2889 err = len_sum; 2890 goto out_status; 2891 } 2892 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2893 addr, hlen, copylen, &sockc); 2894 if (likely(tp_len >= 0) && 2895 tp_len > dev->mtu + reserve && 2896 !vnet_hdr_sz && 2897 !packet_extra_vlan_len_allowed(dev, skb)) 2898 tp_len = -EMSGSIZE; 2899 2900 if (unlikely(tp_len < 0)) { 2901 tpacket_error: 2902 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2903 __packet_set_status(po, ph, 2904 TP_STATUS_AVAILABLE); 2905 packet_increment_head(&po->tx_ring); 2906 kfree_skb(skb); 2907 continue; 2908 } else { 2909 status = TP_STATUS_WRONG_FORMAT; 2910 err = tp_len; 2911 goto out_status; 2912 } 2913 } 2914 2915 if (vnet_hdr_sz) { 2916 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { 2917 tp_len = -EINVAL; 2918 goto tpacket_error; 2919 } 2920 virtio_net_hdr_set_proto(skb, vnet_hdr); 2921 } 2922 2923 skb->destructor = tpacket_destruct_skb; 2924 __packet_set_status(po, ph, TP_STATUS_SENDING); 2925 packet_inc_pending(&po->tx_ring); 2926 2927 status = TP_STATUS_SEND_REQUEST; 2928 err = packet_xmit(po, skb); 2929 if (unlikely(err != 0)) { 2930 if (err > 0) 2931 err = net_xmit_errno(err); 2932 if (err && __packet_get_status(po, ph) == 2933 TP_STATUS_AVAILABLE) { 2934 /* skb was destructed already */ 2935 skb = NULL; 2936 goto out_status; 2937 } 2938 /* 2939 * skb was dropped but not destructed yet; 2940 * let's treat it like congestion or err < 0 2941 */ 2942 err = 0; 2943 } 2944 packet_increment_head(&po->tx_ring); 2945 len_sum += tp_len; 2946 } while (likely((ph != NULL) || 2947 /* Note: packet_read_pending() might be slow if we have 2948 * to call it as it's per_cpu variable, but in fast-path 2949 * we already short-circuit the loop with the first 2950 * condition, and luckily don't have to go that path 2951 * anyway. 2952 */ 2953 (need_wait && packet_read_pending(&po->tx_ring)))); 2954 2955 err = len_sum; 2956 goto out_put; 2957 2958 out_status: 2959 __packet_set_status(po, ph, status); 2960 kfree_skb(skb); 2961 out_put: 2962 dev_put(dev); 2963 out: 2964 mutex_unlock(&po->pg_vec_lock); 2965 return err; 2966 } 2967 2968 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2969 size_t reserve, size_t len, 2970 size_t linear, int noblock, 2971 int *err) 2972 { 2973 struct sk_buff *skb; 2974 2975 /* Under a page? Don't bother with paged skb. */ 2976 if (prepad + len < PAGE_SIZE || !linear) 2977 linear = len; 2978 2979 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2980 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2981 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2982 err, PAGE_ALLOC_COSTLY_ORDER); 2983 if (!skb) 2984 return NULL; 2985 2986 skb_reserve(skb, reserve); 2987 skb_put(skb, linear); 2988 skb->data_len = len - linear; 2989 skb->len += len - linear; 2990 2991 return skb; 2992 } 2993 2994 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2995 { 2996 struct sock *sk = sock->sk; 2997 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2998 struct sk_buff *skb; 2999 struct net_device *dev; 3000 __be16 proto; 3001 unsigned char *addr = NULL; 3002 int err, reserve = 0; 3003 struct sockcm_cookie sockc; 3004 struct virtio_net_hdr vnet_hdr = { 0 }; 3005 int offset = 0; 3006 struct packet_sock *po = pkt_sk(sk); 3007 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 3008 int hlen, tlen, linear; 3009 int extra_len = 0; 3010 3011 /* 3012 * Get and verify the address. 3013 */ 3014 3015 if (likely(saddr == NULL)) { 3016 dev = packet_cached_dev_get(po); 3017 proto = READ_ONCE(po->num); 3018 } else { 3019 err = -EINVAL; 3020 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 3021 goto out; 3022 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 3023 goto out; 3024 proto = saddr->sll_protocol; 3025 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 3026 if (sock->type == SOCK_DGRAM) { 3027 if (dev && msg->msg_namelen < dev->addr_len + 3028 offsetof(struct sockaddr_ll, sll_addr)) 3029 goto out_unlock; 3030 addr = saddr->sll_addr; 3031 } 3032 } 3033 3034 err = -ENXIO; 3035 if (unlikely(dev == NULL)) 3036 goto out_unlock; 3037 err = -ENETDOWN; 3038 if (unlikely(!(dev->flags & IFF_UP))) 3039 goto out_unlock; 3040 3041 sockcm_init(&sockc, sk); 3042 if (msg->msg_controllen) { 3043 err = sock_cmsg_send(sk, msg, &sockc); 3044 if (unlikely(err)) 3045 goto out_unlock; 3046 } 3047 3048 if (sock->type == SOCK_RAW) 3049 reserve = dev->hard_header_len; 3050 if (vnet_hdr_sz) { 3051 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3052 if (err) 3053 goto out_unlock; 3054 } 3055 3056 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3057 if (!netif_supports_nofcs(dev)) { 3058 err = -EPROTONOSUPPORT; 3059 goto out_unlock; 3060 } 3061 extra_len = 4; /* We're doing our own CRC */ 3062 } 3063 3064 err = -EMSGSIZE; 3065 if (!vnet_hdr.gso_type && 3066 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3067 goto out_unlock; 3068 3069 err = -ENOBUFS; 3070 hlen = LL_RESERVED_SPACE(dev); 3071 tlen = dev->needed_tailroom; 3072 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3073 linear = max(linear, min_t(int, len, dev->hard_header_len)); 3074 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3075 msg->msg_flags & MSG_DONTWAIT, &err); 3076 if (skb == NULL) 3077 goto out_unlock; 3078 3079 skb_reset_network_header(skb); 3080 3081 err = -EINVAL; 3082 if (sock->type == SOCK_DGRAM) { 3083 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3084 if (unlikely(offset < 0)) 3085 goto out_free; 3086 } else if (reserve) { 3087 skb_reserve(skb, -reserve); 3088 if (len < reserve + sizeof(struct ipv6hdr) && 3089 dev->min_header_len != dev->hard_header_len) 3090 skb_reset_network_header(skb); 3091 } 3092 3093 /* Returns -EFAULT on error */ 3094 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3095 if (err) 3096 goto out_free; 3097 3098 if ((sock->type == SOCK_RAW && 3099 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3100 err = -EINVAL; 3101 goto out_free; 3102 } 3103 3104 skb_setup_tx_timestamp(skb, &sockc); 3105 3106 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3107 !packet_extra_vlan_len_allowed(dev, skb)) { 3108 err = -EMSGSIZE; 3109 goto out_free; 3110 } 3111 3112 skb->protocol = proto; 3113 skb->dev = dev; 3114 skb->priority = sockc.priority; 3115 skb->mark = sockc.mark; 3116 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3117 3118 if (unlikely(extra_len == 4)) 3119 skb->no_fcs = 1; 3120 3121 packet_parse_headers(skb, sock); 3122 3123 if (vnet_hdr_sz) { 3124 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3125 if (err) 3126 goto out_free; 3127 len += vnet_hdr_sz; 3128 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3129 } 3130 3131 err = packet_xmit(po, skb); 3132 3133 if (unlikely(err != 0)) { 3134 if (err > 0) 3135 err = net_xmit_errno(err); 3136 if (err) 3137 goto out_unlock; 3138 } 3139 3140 dev_put(dev); 3141 3142 return len; 3143 3144 out_free: 3145 kfree_skb(skb); 3146 out_unlock: 3147 dev_put(dev); 3148 out: 3149 return err; 3150 } 3151 3152 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3153 { 3154 struct sock *sk = sock->sk; 3155 struct packet_sock *po = pkt_sk(sk); 3156 3157 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3158 * tpacket_snd() will redo the check safely. 3159 */ 3160 if (data_race(po->tx_ring.pg_vec)) 3161 return tpacket_snd(po, msg); 3162 3163 return packet_snd(sock, msg, len); 3164 } 3165 3166 /* 3167 * Close a PACKET socket. This is fairly simple. We immediately go 3168 * to 'closed' state and remove our protocol entry in the device list. 3169 */ 3170 3171 static int packet_release(struct socket *sock) 3172 { 3173 struct sock *sk = sock->sk; 3174 struct packet_sock *po; 3175 struct packet_fanout *f; 3176 struct net *net; 3177 union tpacket_req_u req_u; 3178 3179 if (!sk) 3180 return 0; 3181 3182 net = sock_net(sk); 3183 po = pkt_sk(sk); 3184 3185 mutex_lock(&net->packet.sklist_lock); 3186 sk_del_node_init_rcu(sk); 3187 mutex_unlock(&net->packet.sklist_lock); 3188 3189 sock_prot_inuse_add(net, sk->sk_prot, -1); 3190 3191 spin_lock(&po->bind_lock); 3192 unregister_prot_hook(sk, false); 3193 packet_cached_dev_reset(po); 3194 3195 if (po->prot_hook.dev) { 3196 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3197 po->prot_hook.dev = NULL; 3198 } 3199 spin_unlock(&po->bind_lock); 3200 3201 packet_flush_mclist(sk); 3202 3203 lock_sock(sk); 3204 if (po->rx_ring.pg_vec) { 3205 memset(&req_u, 0, sizeof(req_u)); 3206 packet_set_ring(sk, &req_u, 1, 0); 3207 } 3208 3209 if (po->tx_ring.pg_vec) { 3210 memset(&req_u, 0, sizeof(req_u)); 3211 packet_set_ring(sk, &req_u, 1, 1); 3212 } 3213 release_sock(sk); 3214 3215 f = fanout_release(sk); 3216 3217 synchronize_net(); 3218 3219 kfree(po->rollover); 3220 if (f) { 3221 fanout_release_data(f); 3222 kvfree(f); 3223 } 3224 /* 3225 * Now the socket is dead. No more input will appear. 3226 */ 3227 sock_orphan(sk); 3228 sock->sk = NULL; 3229 3230 /* Purge queues */ 3231 3232 skb_queue_purge(&sk->sk_receive_queue); 3233 packet_free_pending(po); 3234 3235 sock_put(sk); 3236 return 0; 3237 } 3238 3239 /* 3240 * Attach a packet hook. 3241 */ 3242 3243 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3244 __be16 proto) 3245 { 3246 struct packet_sock *po = pkt_sk(sk); 3247 struct net_device *dev = NULL; 3248 bool unlisted = false; 3249 bool need_rehook; 3250 int ret = 0; 3251 3252 lock_sock(sk); 3253 spin_lock(&po->bind_lock); 3254 if (!proto) 3255 proto = po->num; 3256 3257 rcu_read_lock(); 3258 3259 if (po->fanout) { 3260 ret = -EINVAL; 3261 goto out_unlock; 3262 } 3263 3264 if (name) { 3265 dev = dev_get_by_name_rcu(sock_net(sk), name); 3266 if (!dev) { 3267 ret = -ENODEV; 3268 goto out_unlock; 3269 } 3270 } else if (ifindex) { 3271 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3272 if (!dev) { 3273 ret = -ENODEV; 3274 goto out_unlock; 3275 } 3276 } 3277 3278 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3279 3280 if (need_rehook) { 3281 dev_hold(dev); 3282 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3283 rcu_read_unlock(); 3284 /* prevents packet_notifier() from calling 3285 * register_prot_hook() 3286 */ 3287 WRITE_ONCE(po->num, 0); 3288 __unregister_prot_hook(sk, true); 3289 rcu_read_lock(); 3290 if (dev) 3291 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3292 dev->ifindex); 3293 } 3294 3295 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3296 WRITE_ONCE(po->num, proto); 3297 po->prot_hook.type = proto; 3298 3299 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3300 3301 if (unlikely(unlisted)) { 3302 po->prot_hook.dev = NULL; 3303 WRITE_ONCE(po->ifindex, -1); 3304 packet_cached_dev_reset(po); 3305 } else { 3306 netdev_hold(dev, &po->prot_hook.dev_tracker, 3307 GFP_ATOMIC); 3308 po->prot_hook.dev = dev; 3309 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3310 packet_cached_dev_assign(po, dev); 3311 } 3312 dev_put(dev); 3313 } 3314 3315 if (proto == 0 || !need_rehook) 3316 goto out_unlock; 3317 3318 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3319 register_prot_hook(sk); 3320 } else { 3321 sk->sk_err = ENETDOWN; 3322 if (!sock_flag(sk, SOCK_DEAD)) 3323 sk_error_report(sk); 3324 } 3325 3326 out_unlock: 3327 rcu_read_unlock(); 3328 spin_unlock(&po->bind_lock); 3329 release_sock(sk); 3330 return ret; 3331 } 3332 3333 /* 3334 * Bind a packet socket to a device 3335 */ 3336 3337 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3338 int addr_len) 3339 { 3340 struct sock *sk = sock->sk; 3341 char name[sizeof(uaddr->sa_data_min) + 1]; 3342 3343 /* 3344 * Check legality 3345 */ 3346 3347 if (addr_len != sizeof(struct sockaddr)) 3348 return -EINVAL; 3349 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3350 * zero-terminated. 3351 */ 3352 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min)); 3353 name[sizeof(uaddr->sa_data_min)] = 0; 3354 3355 return packet_do_bind(sk, name, 0, 0); 3356 } 3357 3358 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3359 { 3360 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3361 struct sock *sk = sock->sk; 3362 3363 /* 3364 * Check legality 3365 */ 3366 3367 if (addr_len < sizeof(struct sockaddr_ll)) 3368 return -EINVAL; 3369 if (sll->sll_family != AF_PACKET) 3370 return -EINVAL; 3371 3372 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3373 } 3374 3375 static struct proto packet_proto = { 3376 .name = "PACKET", 3377 .owner = THIS_MODULE, 3378 .obj_size = sizeof(struct packet_sock), 3379 }; 3380 3381 /* 3382 * Create a packet of type SOCK_PACKET. 3383 */ 3384 3385 static int packet_create(struct net *net, struct socket *sock, int protocol, 3386 int kern) 3387 { 3388 struct sock *sk; 3389 struct packet_sock *po; 3390 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3391 int err; 3392 3393 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3394 return -EPERM; 3395 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3396 sock->type != SOCK_PACKET) 3397 return -ESOCKTNOSUPPORT; 3398 3399 sock->state = SS_UNCONNECTED; 3400 3401 err = -ENOBUFS; 3402 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3403 if (sk == NULL) 3404 goto out; 3405 3406 sock->ops = &packet_ops; 3407 if (sock->type == SOCK_PACKET) 3408 sock->ops = &packet_ops_spkt; 3409 3410 po = pkt_sk(sk); 3411 err = packet_alloc_pending(po); 3412 if (err) 3413 goto out_sk_free; 3414 3415 sock_init_data(sock, sk); 3416 3417 init_completion(&po->skb_completion); 3418 sk->sk_family = PF_PACKET; 3419 po->num = proto; 3420 3421 packet_cached_dev_reset(po); 3422 3423 sk->sk_destruct = packet_sock_destruct; 3424 3425 /* 3426 * Attach a protocol block 3427 */ 3428 3429 spin_lock_init(&po->bind_lock); 3430 mutex_init(&po->pg_vec_lock); 3431 po->rollover = NULL; 3432 po->prot_hook.func = packet_rcv; 3433 3434 if (sock->type == SOCK_PACKET) 3435 po->prot_hook.func = packet_rcv_spkt; 3436 3437 po->prot_hook.af_packet_priv = sk; 3438 po->prot_hook.af_packet_net = sock_net(sk); 3439 3440 if (proto) { 3441 po->prot_hook.type = proto; 3442 __register_prot_hook(sk); 3443 } 3444 3445 mutex_lock(&net->packet.sklist_lock); 3446 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3447 mutex_unlock(&net->packet.sklist_lock); 3448 3449 sock_prot_inuse_add(net, &packet_proto, 1); 3450 3451 return 0; 3452 out_sk_free: 3453 sk_free(sk); 3454 out: 3455 return err; 3456 } 3457 3458 /* 3459 * Pull a packet from our receive queue and hand it to the user. 3460 * If necessary we block. 3461 */ 3462 3463 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3464 int flags) 3465 { 3466 struct sock *sk = sock->sk; 3467 struct sk_buff *skb; 3468 int copied, err; 3469 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3470 unsigned int origlen = 0; 3471 3472 err = -EINVAL; 3473 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3474 goto out; 3475 3476 #if 0 3477 /* What error should we return now? EUNATTACH? */ 3478 if (pkt_sk(sk)->ifindex < 0) 3479 return -ENODEV; 3480 #endif 3481 3482 if (flags & MSG_ERRQUEUE) { 3483 err = sock_recv_errqueue(sk, msg, len, 3484 SOL_PACKET, PACKET_TX_TIMESTAMP); 3485 goto out; 3486 } 3487 3488 /* 3489 * Call the generic datagram receiver. This handles all sorts 3490 * of horrible races and re-entrancy so we can forget about it 3491 * in the protocol layers. 3492 * 3493 * Now it will return ENETDOWN, if device have just gone down, 3494 * but then it will block. 3495 */ 3496 3497 skb = skb_recv_datagram(sk, flags, &err); 3498 3499 /* 3500 * An error occurred so return it. Because skb_recv_datagram() 3501 * handles the blocking we don't see and worry about blocking 3502 * retries. 3503 */ 3504 3505 if (skb == NULL) 3506 goto out; 3507 3508 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3509 3510 if (vnet_hdr_len) { 3511 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3512 if (err) 3513 goto out_free; 3514 } 3515 3516 /* You lose any data beyond the buffer you gave. If it worries 3517 * a user program they can ask the device for its MTU 3518 * anyway. 3519 */ 3520 copied = skb->len; 3521 if (copied > len) { 3522 copied = len; 3523 msg->msg_flags |= MSG_TRUNC; 3524 } 3525 3526 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3527 if (err) 3528 goto out_free; 3529 3530 if (sock->type != SOCK_PACKET) { 3531 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3532 3533 /* Original length was stored in sockaddr_ll fields */ 3534 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3535 sll->sll_family = AF_PACKET; 3536 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3537 vlan_get_protocol_dgram(skb) : skb->protocol; 3538 } 3539 3540 sock_recv_cmsgs(msg, sk, skb); 3541 3542 if (msg->msg_name) { 3543 const size_t max_len = min(sizeof(skb->cb), 3544 sizeof(struct sockaddr_storage)); 3545 int copy_len; 3546 3547 /* If the address length field is there to be filled 3548 * in, we fill it in now. 3549 */ 3550 if (sock->type == SOCK_PACKET) { 3551 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3552 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3553 copy_len = msg->msg_namelen; 3554 } else { 3555 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3556 3557 msg->msg_namelen = sll->sll_halen + 3558 offsetof(struct sockaddr_ll, sll_addr); 3559 copy_len = msg->msg_namelen; 3560 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3561 memset(msg->msg_name + 3562 offsetof(struct sockaddr_ll, sll_addr), 3563 0, sizeof(sll->sll_addr)); 3564 msg->msg_namelen = sizeof(struct sockaddr_ll); 3565 } 3566 } 3567 if (WARN_ON_ONCE(copy_len > max_len)) { 3568 copy_len = max_len; 3569 msg->msg_namelen = copy_len; 3570 } 3571 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3572 } 3573 3574 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3575 struct tpacket_auxdata aux; 3576 3577 aux.tp_status = TP_STATUS_USER; 3578 if (skb->ip_summed == CHECKSUM_PARTIAL) 3579 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3580 else if (skb->pkt_type != PACKET_OUTGOING && 3581 skb_csum_unnecessary(skb)) 3582 aux.tp_status |= TP_STATUS_CSUM_VALID; 3583 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3584 aux.tp_status |= TP_STATUS_GSO_TCP; 3585 3586 aux.tp_len = origlen; 3587 aux.tp_snaplen = skb->len; 3588 aux.tp_mac = 0; 3589 aux.tp_net = skb_network_offset(skb); 3590 if (skb_vlan_tag_present(skb)) { 3591 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3592 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3593 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3594 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3595 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3596 struct net_device *dev; 3597 3598 rcu_read_lock(); 3599 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3600 if (dev) { 3601 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3602 aux.tp_vlan_tpid = ntohs(skb->protocol); 3603 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3604 } else { 3605 aux.tp_vlan_tci = 0; 3606 aux.tp_vlan_tpid = 0; 3607 } 3608 rcu_read_unlock(); 3609 } else { 3610 aux.tp_vlan_tci = 0; 3611 aux.tp_vlan_tpid = 0; 3612 } 3613 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3614 } 3615 3616 /* 3617 * Free or return the buffer as appropriate. Again this 3618 * hides all the races and re-entrancy issues from us. 3619 */ 3620 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3621 3622 out_free: 3623 skb_free_datagram(sk, skb); 3624 out: 3625 return err; 3626 } 3627 3628 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3629 int peer) 3630 { 3631 struct net_device *dev; 3632 struct sock *sk = sock->sk; 3633 3634 if (peer) 3635 return -EOPNOTSUPP; 3636 3637 uaddr->sa_family = AF_PACKET; 3638 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min)); 3639 rcu_read_lock(); 3640 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3641 if (dev) 3642 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min)); 3643 rcu_read_unlock(); 3644 3645 return sizeof(*uaddr); 3646 } 3647 3648 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3649 int peer) 3650 { 3651 struct net_device *dev; 3652 struct sock *sk = sock->sk; 3653 struct packet_sock *po = pkt_sk(sk); 3654 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3655 int ifindex; 3656 3657 if (peer) 3658 return -EOPNOTSUPP; 3659 3660 ifindex = READ_ONCE(po->ifindex); 3661 sll->sll_family = AF_PACKET; 3662 sll->sll_ifindex = ifindex; 3663 sll->sll_protocol = READ_ONCE(po->num); 3664 sll->sll_pkttype = 0; 3665 rcu_read_lock(); 3666 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3667 if (dev) { 3668 sll->sll_hatype = dev->type; 3669 sll->sll_halen = dev->addr_len; 3670 3671 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3672 memcpy(((struct sockaddr_storage *)sll)->__data + 3673 offsetof(struct sockaddr_ll, sll_addr) - 3674 offsetofend(struct sockaddr_ll, sll_family), 3675 dev->dev_addr, dev->addr_len); 3676 } else { 3677 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3678 sll->sll_halen = 0; 3679 } 3680 rcu_read_unlock(); 3681 3682 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3683 } 3684 3685 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3686 int what) 3687 { 3688 switch (i->type) { 3689 case PACKET_MR_MULTICAST: 3690 if (i->alen != dev->addr_len) 3691 return -EINVAL; 3692 if (what > 0) 3693 return dev_mc_add(dev, i->addr); 3694 else 3695 return dev_mc_del(dev, i->addr); 3696 break; 3697 case PACKET_MR_PROMISC: 3698 return dev_set_promiscuity(dev, what); 3699 case PACKET_MR_ALLMULTI: 3700 return dev_set_allmulti(dev, what); 3701 case PACKET_MR_UNICAST: 3702 if (i->alen != dev->addr_len) 3703 return -EINVAL; 3704 if (what > 0) 3705 return dev_uc_add(dev, i->addr); 3706 else 3707 return dev_uc_del(dev, i->addr); 3708 break; 3709 default: 3710 break; 3711 } 3712 return 0; 3713 } 3714 3715 static void packet_dev_mclist_delete(struct net_device *dev, 3716 struct packet_mclist **mlp) 3717 { 3718 struct packet_mclist *ml; 3719 3720 while ((ml = *mlp) != NULL) { 3721 if (ml->ifindex == dev->ifindex) { 3722 packet_dev_mc(dev, ml, -1); 3723 *mlp = ml->next; 3724 kfree(ml); 3725 } else 3726 mlp = &ml->next; 3727 } 3728 } 3729 3730 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3731 { 3732 struct packet_sock *po = pkt_sk(sk); 3733 struct packet_mclist *ml, *i; 3734 struct net_device *dev; 3735 int err; 3736 3737 rtnl_lock(); 3738 3739 err = -ENODEV; 3740 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3741 if (!dev) 3742 goto done; 3743 3744 err = -EINVAL; 3745 if (mreq->mr_alen > dev->addr_len) 3746 goto done; 3747 3748 err = -ENOBUFS; 3749 i = kmalloc(sizeof(*i), GFP_KERNEL); 3750 if (i == NULL) 3751 goto done; 3752 3753 err = 0; 3754 for (ml = po->mclist; ml; ml = ml->next) { 3755 if (ml->ifindex == mreq->mr_ifindex && 3756 ml->type == mreq->mr_type && 3757 ml->alen == mreq->mr_alen && 3758 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3759 ml->count++; 3760 /* Free the new element ... */ 3761 kfree(i); 3762 goto done; 3763 } 3764 } 3765 3766 i->type = mreq->mr_type; 3767 i->ifindex = mreq->mr_ifindex; 3768 i->alen = mreq->mr_alen; 3769 memcpy(i->addr, mreq->mr_address, i->alen); 3770 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3771 i->count = 1; 3772 i->next = po->mclist; 3773 po->mclist = i; 3774 err = packet_dev_mc(dev, i, 1); 3775 if (err) { 3776 po->mclist = i->next; 3777 kfree(i); 3778 } 3779 3780 done: 3781 rtnl_unlock(); 3782 return err; 3783 } 3784 3785 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3786 { 3787 struct packet_mclist *ml, **mlp; 3788 3789 rtnl_lock(); 3790 3791 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3792 if (ml->ifindex == mreq->mr_ifindex && 3793 ml->type == mreq->mr_type && 3794 ml->alen == mreq->mr_alen && 3795 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3796 if (--ml->count == 0) { 3797 struct net_device *dev; 3798 *mlp = ml->next; 3799 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3800 if (dev) 3801 packet_dev_mc(dev, ml, -1); 3802 kfree(ml); 3803 } 3804 break; 3805 } 3806 } 3807 rtnl_unlock(); 3808 return 0; 3809 } 3810 3811 static void packet_flush_mclist(struct sock *sk) 3812 { 3813 struct packet_sock *po = pkt_sk(sk); 3814 struct packet_mclist *ml; 3815 3816 if (!po->mclist) 3817 return; 3818 3819 rtnl_lock(); 3820 while ((ml = po->mclist) != NULL) { 3821 struct net_device *dev; 3822 3823 po->mclist = ml->next; 3824 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3825 if (dev != NULL) 3826 packet_dev_mc(dev, ml, -1); 3827 kfree(ml); 3828 } 3829 rtnl_unlock(); 3830 } 3831 3832 static int 3833 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3834 unsigned int optlen) 3835 { 3836 struct sock *sk = sock->sk; 3837 struct packet_sock *po = pkt_sk(sk); 3838 int ret; 3839 3840 if (level != SOL_PACKET) 3841 return -ENOPROTOOPT; 3842 3843 switch (optname) { 3844 case PACKET_ADD_MEMBERSHIP: 3845 case PACKET_DROP_MEMBERSHIP: 3846 { 3847 struct packet_mreq_max mreq; 3848 int len = optlen; 3849 memset(&mreq, 0, sizeof(mreq)); 3850 if (len < sizeof(struct packet_mreq)) 3851 return -EINVAL; 3852 if (len > sizeof(mreq)) 3853 len = sizeof(mreq); 3854 if (copy_from_sockptr(&mreq, optval, len)) 3855 return -EFAULT; 3856 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3857 return -EINVAL; 3858 if (optname == PACKET_ADD_MEMBERSHIP) 3859 ret = packet_mc_add(sk, &mreq); 3860 else 3861 ret = packet_mc_drop(sk, &mreq); 3862 return ret; 3863 } 3864 3865 case PACKET_RX_RING: 3866 case PACKET_TX_RING: 3867 { 3868 union tpacket_req_u req_u; 3869 3870 ret = -EINVAL; 3871 lock_sock(sk); 3872 switch (po->tp_version) { 3873 case TPACKET_V1: 3874 case TPACKET_V2: 3875 if (optlen < sizeof(req_u.req)) 3876 break; 3877 ret = copy_from_sockptr(&req_u.req, optval, 3878 sizeof(req_u.req)) ? 3879 -EINVAL : 0; 3880 break; 3881 case TPACKET_V3: 3882 default: 3883 if (optlen < sizeof(req_u.req3)) 3884 break; 3885 ret = copy_from_sockptr(&req_u.req3, optval, 3886 sizeof(req_u.req3)) ? 3887 -EINVAL : 0; 3888 break; 3889 } 3890 if (!ret) 3891 ret = packet_set_ring(sk, &req_u, 0, 3892 optname == PACKET_TX_RING); 3893 release_sock(sk); 3894 return ret; 3895 } 3896 case PACKET_COPY_THRESH: 3897 { 3898 int val; 3899 3900 if (optlen != sizeof(val)) 3901 return -EINVAL; 3902 if (copy_from_sockptr(&val, optval, sizeof(val))) 3903 return -EFAULT; 3904 3905 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3906 return 0; 3907 } 3908 case PACKET_VERSION: 3909 { 3910 int val; 3911 3912 if (optlen != sizeof(val)) 3913 return -EINVAL; 3914 if (copy_from_sockptr(&val, optval, sizeof(val))) 3915 return -EFAULT; 3916 switch (val) { 3917 case TPACKET_V1: 3918 case TPACKET_V2: 3919 case TPACKET_V3: 3920 break; 3921 default: 3922 return -EINVAL; 3923 } 3924 lock_sock(sk); 3925 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3926 ret = -EBUSY; 3927 } else { 3928 po->tp_version = val; 3929 ret = 0; 3930 } 3931 release_sock(sk); 3932 return ret; 3933 } 3934 case PACKET_RESERVE: 3935 { 3936 unsigned int val; 3937 3938 if (optlen != sizeof(val)) 3939 return -EINVAL; 3940 if (copy_from_sockptr(&val, optval, sizeof(val))) 3941 return -EFAULT; 3942 if (val > INT_MAX) 3943 return -EINVAL; 3944 lock_sock(sk); 3945 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3946 ret = -EBUSY; 3947 } else { 3948 po->tp_reserve = val; 3949 ret = 0; 3950 } 3951 release_sock(sk); 3952 return ret; 3953 } 3954 case PACKET_LOSS: 3955 { 3956 unsigned int val; 3957 3958 if (optlen != sizeof(val)) 3959 return -EINVAL; 3960 if (copy_from_sockptr(&val, optval, sizeof(val))) 3961 return -EFAULT; 3962 3963 lock_sock(sk); 3964 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3965 ret = -EBUSY; 3966 } else { 3967 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3968 ret = 0; 3969 } 3970 release_sock(sk); 3971 return ret; 3972 } 3973 case PACKET_AUXDATA: 3974 { 3975 int val; 3976 3977 if (optlen < sizeof(val)) 3978 return -EINVAL; 3979 if (copy_from_sockptr(&val, optval, sizeof(val))) 3980 return -EFAULT; 3981 3982 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3983 return 0; 3984 } 3985 case PACKET_ORIGDEV: 3986 { 3987 int val; 3988 3989 if (optlen < sizeof(val)) 3990 return -EINVAL; 3991 if (copy_from_sockptr(&val, optval, sizeof(val))) 3992 return -EFAULT; 3993 3994 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 3995 return 0; 3996 } 3997 case PACKET_VNET_HDR: 3998 case PACKET_VNET_HDR_SZ: 3999 { 4000 int val, hdr_len; 4001 4002 if (sock->type != SOCK_RAW) 4003 return -EINVAL; 4004 if (optlen < sizeof(val)) 4005 return -EINVAL; 4006 if (copy_from_sockptr(&val, optval, sizeof(val))) 4007 return -EFAULT; 4008 4009 if (optname == PACKET_VNET_HDR_SZ) { 4010 if (val && val != sizeof(struct virtio_net_hdr) && 4011 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 4012 return -EINVAL; 4013 hdr_len = val; 4014 } else { 4015 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 4016 } 4017 lock_sock(sk); 4018 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 4019 ret = -EBUSY; 4020 } else { 4021 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 4022 ret = 0; 4023 } 4024 release_sock(sk); 4025 return ret; 4026 } 4027 case PACKET_TIMESTAMP: 4028 { 4029 int val; 4030 4031 if (optlen != sizeof(val)) 4032 return -EINVAL; 4033 if (copy_from_sockptr(&val, optval, sizeof(val))) 4034 return -EFAULT; 4035 4036 WRITE_ONCE(po->tp_tstamp, val); 4037 return 0; 4038 } 4039 case PACKET_FANOUT: 4040 { 4041 struct fanout_args args = { 0 }; 4042 4043 if (optlen != sizeof(int) && optlen != sizeof(args)) 4044 return -EINVAL; 4045 if (copy_from_sockptr(&args, optval, optlen)) 4046 return -EFAULT; 4047 4048 return fanout_add(sk, &args); 4049 } 4050 case PACKET_FANOUT_DATA: 4051 { 4052 /* Paired with the WRITE_ONCE() in fanout_add() */ 4053 if (!READ_ONCE(po->fanout)) 4054 return -EINVAL; 4055 4056 return fanout_set_data(po, optval, optlen); 4057 } 4058 case PACKET_IGNORE_OUTGOING: 4059 { 4060 int val; 4061 4062 if (optlen != sizeof(val)) 4063 return -EINVAL; 4064 if (copy_from_sockptr(&val, optval, sizeof(val))) 4065 return -EFAULT; 4066 if (val < 0 || val > 1) 4067 return -EINVAL; 4068 4069 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4070 return 0; 4071 } 4072 case PACKET_TX_HAS_OFF: 4073 { 4074 unsigned int val; 4075 4076 if (optlen != sizeof(val)) 4077 return -EINVAL; 4078 if (copy_from_sockptr(&val, optval, sizeof(val))) 4079 return -EFAULT; 4080 4081 lock_sock(sk); 4082 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4083 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4084 4085 release_sock(sk); 4086 return 0; 4087 } 4088 case PACKET_QDISC_BYPASS: 4089 { 4090 int val; 4091 4092 if (optlen != sizeof(val)) 4093 return -EINVAL; 4094 if (copy_from_sockptr(&val, optval, sizeof(val))) 4095 return -EFAULT; 4096 4097 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4098 return 0; 4099 } 4100 default: 4101 return -ENOPROTOOPT; 4102 } 4103 } 4104 4105 static int packet_getsockopt(struct socket *sock, int level, int optname, 4106 char __user *optval, int __user *optlen) 4107 { 4108 int len; 4109 int val, lv = sizeof(val); 4110 struct sock *sk = sock->sk; 4111 struct packet_sock *po = pkt_sk(sk); 4112 void *data = &val; 4113 union tpacket_stats_u st; 4114 struct tpacket_rollover_stats rstats; 4115 int drops; 4116 4117 if (level != SOL_PACKET) 4118 return -ENOPROTOOPT; 4119 4120 if (get_user(len, optlen)) 4121 return -EFAULT; 4122 4123 if (len < 0) 4124 return -EINVAL; 4125 4126 switch (optname) { 4127 case PACKET_STATISTICS: 4128 spin_lock_bh(&sk->sk_receive_queue.lock); 4129 memcpy(&st, &po->stats, sizeof(st)); 4130 memset(&po->stats, 0, sizeof(po->stats)); 4131 spin_unlock_bh(&sk->sk_receive_queue.lock); 4132 drops = atomic_xchg(&po->tp_drops, 0); 4133 4134 if (po->tp_version == TPACKET_V3) { 4135 lv = sizeof(struct tpacket_stats_v3); 4136 st.stats3.tp_drops = drops; 4137 st.stats3.tp_packets += drops; 4138 data = &st.stats3; 4139 } else { 4140 lv = sizeof(struct tpacket_stats); 4141 st.stats1.tp_drops = drops; 4142 st.stats1.tp_packets += drops; 4143 data = &st.stats1; 4144 } 4145 4146 break; 4147 case PACKET_AUXDATA: 4148 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4149 break; 4150 case PACKET_ORIGDEV: 4151 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4152 break; 4153 case PACKET_VNET_HDR: 4154 val = !!READ_ONCE(po->vnet_hdr_sz); 4155 break; 4156 case PACKET_VNET_HDR_SZ: 4157 val = READ_ONCE(po->vnet_hdr_sz); 4158 break; 4159 case PACKET_COPY_THRESH: 4160 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4161 break; 4162 case PACKET_VERSION: 4163 val = po->tp_version; 4164 break; 4165 case PACKET_HDRLEN: 4166 if (len > sizeof(int)) 4167 len = sizeof(int); 4168 if (len < sizeof(int)) 4169 return -EINVAL; 4170 if (copy_from_user(&val, optval, len)) 4171 return -EFAULT; 4172 switch (val) { 4173 case TPACKET_V1: 4174 val = sizeof(struct tpacket_hdr); 4175 break; 4176 case TPACKET_V2: 4177 val = sizeof(struct tpacket2_hdr); 4178 break; 4179 case TPACKET_V3: 4180 val = sizeof(struct tpacket3_hdr); 4181 break; 4182 default: 4183 return -EINVAL; 4184 } 4185 break; 4186 case PACKET_RESERVE: 4187 val = po->tp_reserve; 4188 break; 4189 case PACKET_LOSS: 4190 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4191 break; 4192 case PACKET_TIMESTAMP: 4193 val = READ_ONCE(po->tp_tstamp); 4194 break; 4195 case PACKET_FANOUT: 4196 val = (po->fanout ? 4197 ((u32)po->fanout->id | 4198 ((u32)po->fanout->type << 16) | 4199 ((u32)po->fanout->flags << 24)) : 4200 0); 4201 break; 4202 case PACKET_IGNORE_OUTGOING: 4203 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4204 break; 4205 case PACKET_ROLLOVER_STATS: 4206 if (!po->rollover) 4207 return -EINVAL; 4208 rstats.tp_all = atomic_long_read(&po->rollover->num); 4209 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4210 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4211 data = &rstats; 4212 lv = sizeof(rstats); 4213 break; 4214 case PACKET_TX_HAS_OFF: 4215 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4216 break; 4217 case PACKET_QDISC_BYPASS: 4218 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4219 break; 4220 default: 4221 return -ENOPROTOOPT; 4222 } 4223 4224 if (len > lv) 4225 len = lv; 4226 if (put_user(len, optlen)) 4227 return -EFAULT; 4228 if (copy_to_user(optval, data, len)) 4229 return -EFAULT; 4230 return 0; 4231 } 4232 4233 static int packet_notifier(struct notifier_block *this, 4234 unsigned long msg, void *ptr) 4235 { 4236 struct sock *sk; 4237 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4238 struct net *net = dev_net(dev); 4239 4240 rcu_read_lock(); 4241 sk_for_each_rcu(sk, &net->packet.sklist) { 4242 struct packet_sock *po = pkt_sk(sk); 4243 4244 switch (msg) { 4245 case NETDEV_UNREGISTER: 4246 if (po->mclist) 4247 packet_dev_mclist_delete(dev, &po->mclist); 4248 fallthrough; 4249 4250 case NETDEV_DOWN: 4251 if (dev->ifindex == po->ifindex) { 4252 spin_lock(&po->bind_lock); 4253 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4254 __unregister_prot_hook(sk, false); 4255 sk->sk_err = ENETDOWN; 4256 if (!sock_flag(sk, SOCK_DEAD)) 4257 sk_error_report(sk); 4258 } 4259 if (msg == NETDEV_UNREGISTER) { 4260 packet_cached_dev_reset(po); 4261 WRITE_ONCE(po->ifindex, -1); 4262 netdev_put(po->prot_hook.dev, 4263 &po->prot_hook.dev_tracker); 4264 po->prot_hook.dev = NULL; 4265 } 4266 spin_unlock(&po->bind_lock); 4267 } 4268 break; 4269 case NETDEV_UP: 4270 if (dev->ifindex == po->ifindex) { 4271 spin_lock(&po->bind_lock); 4272 if (po->num) 4273 register_prot_hook(sk); 4274 spin_unlock(&po->bind_lock); 4275 } 4276 break; 4277 } 4278 } 4279 rcu_read_unlock(); 4280 return NOTIFY_DONE; 4281 } 4282 4283 4284 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4285 unsigned long arg) 4286 { 4287 struct sock *sk = sock->sk; 4288 4289 switch (cmd) { 4290 case SIOCOUTQ: 4291 { 4292 int amount = sk_wmem_alloc_get(sk); 4293 4294 return put_user(amount, (int __user *)arg); 4295 } 4296 case SIOCINQ: 4297 { 4298 struct sk_buff *skb; 4299 int amount = 0; 4300 4301 spin_lock_bh(&sk->sk_receive_queue.lock); 4302 skb = skb_peek(&sk->sk_receive_queue); 4303 if (skb) 4304 amount = skb->len; 4305 spin_unlock_bh(&sk->sk_receive_queue.lock); 4306 return put_user(amount, (int __user *)arg); 4307 } 4308 #ifdef CONFIG_INET 4309 case SIOCADDRT: 4310 case SIOCDELRT: 4311 case SIOCDARP: 4312 case SIOCGARP: 4313 case SIOCSARP: 4314 case SIOCGIFADDR: 4315 case SIOCSIFADDR: 4316 case SIOCGIFBRDADDR: 4317 case SIOCSIFBRDADDR: 4318 case SIOCGIFNETMASK: 4319 case SIOCSIFNETMASK: 4320 case SIOCGIFDSTADDR: 4321 case SIOCSIFDSTADDR: 4322 case SIOCSIFFLAGS: 4323 return inet_dgram_ops.ioctl(sock, cmd, arg); 4324 #endif 4325 4326 default: 4327 return -ENOIOCTLCMD; 4328 } 4329 return 0; 4330 } 4331 4332 static __poll_t packet_poll(struct file *file, struct socket *sock, 4333 poll_table *wait) 4334 { 4335 struct sock *sk = sock->sk; 4336 struct packet_sock *po = pkt_sk(sk); 4337 __poll_t mask = datagram_poll(file, sock, wait); 4338 4339 spin_lock_bh(&sk->sk_receive_queue.lock); 4340 if (po->rx_ring.pg_vec) { 4341 if (!packet_previous_rx_frame(po, &po->rx_ring, 4342 TP_STATUS_KERNEL)) 4343 mask |= EPOLLIN | EPOLLRDNORM; 4344 } 4345 packet_rcv_try_clear_pressure(po); 4346 spin_unlock_bh(&sk->sk_receive_queue.lock); 4347 spin_lock_bh(&sk->sk_write_queue.lock); 4348 if (po->tx_ring.pg_vec) { 4349 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4350 mask |= EPOLLOUT | EPOLLWRNORM; 4351 } 4352 spin_unlock_bh(&sk->sk_write_queue.lock); 4353 return mask; 4354 } 4355 4356 4357 /* Dirty? Well, I still did not learn better way to account 4358 * for user mmaps. 4359 */ 4360 4361 static void packet_mm_open(struct vm_area_struct *vma) 4362 { 4363 struct file *file = vma->vm_file; 4364 struct socket *sock = file->private_data; 4365 struct sock *sk = sock->sk; 4366 4367 if (sk) 4368 atomic_long_inc(&pkt_sk(sk)->mapped); 4369 } 4370 4371 static void packet_mm_close(struct vm_area_struct *vma) 4372 { 4373 struct file *file = vma->vm_file; 4374 struct socket *sock = file->private_data; 4375 struct sock *sk = sock->sk; 4376 4377 if (sk) 4378 atomic_long_dec(&pkt_sk(sk)->mapped); 4379 } 4380 4381 static const struct vm_operations_struct packet_mmap_ops = { 4382 .open = packet_mm_open, 4383 .close = packet_mm_close, 4384 }; 4385 4386 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4387 unsigned int len) 4388 { 4389 int i; 4390 4391 for (i = 0; i < len; i++) { 4392 if (likely(pg_vec[i].buffer)) { 4393 if (is_vmalloc_addr(pg_vec[i].buffer)) 4394 vfree(pg_vec[i].buffer); 4395 else 4396 free_pages((unsigned long)pg_vec[i].buffer, 4397 order); 4398 pg_vec[i].buffer = NULL; 4399 } 4400 } 4401 kfree(pg_vec); 4402 } 4403 4404 static char *alloc_one_pg_vec_page(unsigned long order) 4405 { 4406 char *buffer; 4407 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4408 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4409 4410 buffer = (char *) __get_free_pages(gfp_flags, order); 4411 if (buffer) 4412 return buffer; 4413 4414 /* __get_free_pages failed, fall back to vmalloc */ 4415 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4416 if (buffer) 4417 return buffer; 4418 4419 /* vmalloc failed, lets dig into swap here */ 4420 gfp_flags &= ~__GFP_NORETRY; 4421 buffer = (char *) __get_free_pages(gfp_flags, order); 4422 if (buffer) 4423 return buffer; 4424 4425 /* complete and utter failure */ 4426 return NULL; 4427 } 4428 4429 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4430 { 4431 unsigned int block_nr = req->tp_block_nr; 4432 struct pgv *pg_vec; 4433 int i; 4434 4435 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN); 4436 if (unlikely(!pg_vec)) 4437 goto out; 4438 4439 for (i = 0; i < block_nr; i++) { 4440 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4441 if (unlikely(!pg_vec[i].buffer)) 4442 goto out_free_pgvec; 4443 } 4444 4445 out: 4446 return pg_vec; 4447 4448 out_free_pgvec: 4449 free_pg_vec(pg_vec, order, block_nr); 4450 pg_vec = NULL; 4451 goto out; 4452 } 4453 4454 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4455 int closing, int tx_ring) 4456 { 4457 struct pgv *pg_vec = NULL; 4458 struct packet_sock *po = pkt_sk(sk); 4459 unsigned long *rx_owner_map = NULL; 4460 int was_running, order = 0; 4461 struct packet_ring_buffer *rb; 4462 struct sk_buff_head *rb_queue; 4463 __be16 num; 4464 int err; 4465 /* Added to avoid minimal code churn */ 4466 struct tpacket_req *req = &req_u->req; 4467 4468 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4469 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4470 4471 err = -EBUSY; 4472 if (!closing) { 4473 if (atomic_long_read(&po->mapped)) 4474 goto out; 4475 if (packet_read_pending(rb)) 4476 goto out; 4477 } 4478 4479 if (req->tp_block_nr) { 4480 unsigned int min_frame_size; 4481 4482 /* Sanity tests and some calculations */ 4483 err = -EBUSY; 4484 if (unlikely(rb->pg_vec)) 4485 goto out; 4486 4487 switch (po->tp_version) { 4488 case TPACKET_V1: 4489 po->tp_hdrlen = TPACKET_HDRLEN; 4490 break; 4491 case TPACKET_V2: 4492 po->tp_hdrlen = TPACKET2_HDRLEN; 4493 break; 4494 case TPACKET_V3: 4495 po->tp_hdrlen = TPACKET3_HDRLEN; 4496 break; 4497 } 4498 4499 err = -EINVAL; 4500 if (unlikely((int)req->tp_block_size <= 0)) 4501 goto out; 4502 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4503 goto out; 4504 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4505 if (po->tp_version >= TPACKET_V3 && 4506 req->tp_block_size < 4507 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4508 goto out; 4509 if (unlikely(req->tp_frame_size < min_frame_size)) 4510 goto out; 4511 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4512 goto out; 4513 4514 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4515 if (unlikely(rb->frames_per_block == 0)) 4516 goto out; 4517 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4518 goto out; 4519 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4520 req->tp_frame_nr)) 4521 goto out; 4522 4523 err = -ENOMEM; 4524 order = get_order(req->tp_block_size); 4525 pg_vec = alloc_pg_vec(req, order); 4526 if (unlikely(!pg_vec)) 4527 goto out; 4528 switch (po->tp_version) { 4529 case TPACKET_V3: 4530 /* Block transmit is not supported yet */ 4531 if (!tx_ring) { 4532 init_prb_bdqc(po, rb, pg_vec, req_u); 4533 } else { 4534 struct tpacket_req3 *req3 = &req_u->req3; 4535 4536 if (req3->tp_retire_blk_tov || 4537 req3->tp_sizeof_priv || 4538 req3->tp_feature_req_word) { 4539 err = -EINVAL; 4540 goto out_free_pg_vec; 4541 } 4542 } 4543 break; 4544 default: 4545 if (!tx_ring) { 4546 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4547 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4548 if (!rx_owner_map) 4549 goto out_free_pg_vec; 4550 } 4551 break; 4552 } 4553 } 4554 /* Done */ 4555 else { 4556 err = -EINVAL; 4557 if (unlikely(req->tp_frame_nr)) 4558 goto out; 4559 } 4560 4561 4562 /* Detach socket from network */ 4563 spin_lock(&po->bind_lock); 4564 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4565 num = po->num; 4566 if (was_running) { 4567 WRITE_ONCE(po->num, 0); 4568 __unregister_prot_hook(sk, false); 4569 } 4570 spin_unlock(&po->bind_lock); 4571 4572 synchronize_net(); 4573 4574 err = -EBUSY; 4575 mutex_lock(&po->pg_vec_lock); 4576 if (closing || atomic_long_read(&po->mapped) == 0) { 4577 err = 0; 4578 spin_lock_bh(&rb_queue->lock); 4579 swap(rb->pg_vec, pg_vec); 4580 if (po->tp_version <= TPACKET_V2) 4581 swap(rb->rx_owner_map, rx_owner_map); 4582 rb->frame_max = (req->tp_frame_nr - 1); 4583 rb->head = 0; 4584 rb->frame_size = req->tp_frame_size; 4585 spin_unlock_bh(&rb_queue->lock); 4586 4587 swap(rb->pg_vec_order, order); 4588 swap(rb->pg_vec_len, req->tp_block_nr); 4589 4590 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4591 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4592 tpacket_rcv : packet_rcv; 4593 skb_queue_purge(rb_queue); 4594 if (atomic_long_read(&po->mapped)) 4595 pr_err("packet_mmap: vma is busy: %ld\n", 4596 atomic_long_read(&po->mapped)); 4597 } 4598 mutex_unlock(&po->pg_vec_lock); 4599 4600 spin_lock(&po->bind_lock); 4601 if (was_running) { 4602 WRITE_ONCE(po->num, num); 4603 register_prot_hook(sk); 4604 } 4605 spin_unlock(&po->bind_lock); 4606 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4607 /* Because we don't support block-based V3 on tx-ring */ 4608 if (!tx_ring) 4609 prb_shutdown_retire_blk_timer(po, rb_queue); 4610 } 4611 4612 out_free_pg_vec: 4613 if (pg_vec) { 4614 bitmap_free(rx_owner_map); 4615 free_pg_vec(pg_vec, order, req->tp_block_nr); 4616 } 4617 out: 4618 return err; 4619 } 4620 4621 static int packet_mmap(struct file *file, struct socket *sock, 4622 struct vm_area_struct *vma) 4623 { 4624 struct sock *sk = sock->sk; 4625 struct packet_sock *po = pkt_sk(sk); 4626 unsigned long size, expected_size; 4627 struct packet_ring_buffer *rb; 4628 unsigned long start; 4629 int err = -EINVAL; 4630 int i; 4631 4632 if (vma->vm_pgoff) 4633 return -EINVAL; 4634 4635 mutex_lock(&po->pg_vec_lock); 4636 4637 expected_size = 0; 4638 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4639 if (rb->pg_vec) { 4640 expected_size += rb->pg_vec_len 4641 * rb->pg_vec_pages 4642 * PAGE_SIZE; 4643 } 4644 } 4645 4646 if (expected_size == 0) 4647 goto out; 4648 4649 size = vma->vm_end - vma->vm_start; 4650 if (size != expected_size) 4651 goto out; 4652 4653 start = vma->vm_start; 4654 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4655 if (rb->pg_vec == NULL) 4656 continue; 4657 4658 for (i = 0; i < rb->pg_vec_len; i++) { 4659 struct page *page; 4660 void *kaddr = rb->pg_vec[i].buffer; 4661 int pg_num; 4662 4663 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4664 page = pgv_to_page(kaddr); 4665 err = vm_insert_page(vma, start, page); 4666 if (unlikely(err)) 4667 goto out; 4668 start += PAGE_SIZE; 4669 kaddr += PAGE_SIZE; 4670 } 4671 } 4672 } 4673 4674 atomic_long_inc(&po->mapped); 4675 vma->vm_ops = &packet_mmap_ops; 4676 err = 0; 4677 4678 out: 4679 mutex_unlock(&po->pg_vec_lock); 4680 return err; 4681 } 4682 4683 static const struct proto_ops packet_ops_spkt = { 4684 .family = PF_PACKET, 4685 .owner = THIS_MODULE, 4686 .release = packet_release, 4687 .bind = packet_bind_spkt, 4688 .connect = sock_no_connect, 4689 .socketpair = sock_no_socketpair, 4690 .accept = sock_no_accept, 4691 .getname = packet_getname_spkt, 4692 .poll = datagram_poll, 4693 .ioctl = packet_ioctl, 4694 .gettstamp = sock_gettstamp, 4695 .listen = sock_no_listen, 4696 .shutdown = sock_no_shutdown, 4697 .sendmsg = packet_sendmsg_spkt, 4698 .recvmsg = packet_recvmsg, 4699 .mmap = sock_no_mmap, 4700 }; 4701 4702 static const struct proto_ops packet_ops = { 4703 .family = PF_PACKET, 4704 .owner = THIS_MODULE, 4705 .release = packet_release, 4706 .bind = packet_bind, 4707 .connect = sock_no_connect, 4708 .socketpair = sock_no_socketpair, 4709 .accept = sock_no_accept, 4710 .getname = packet_getname, 4711 .poll = packet_poll, 4712 .ioctl = packet_ioctl, 4713 .gettstamp = sock_gettstamp, 4714 .listen = sock_no_listen, 4715 .shutdown = sock_no_shutdown, 4716 .setsockopt = packet_setsockopt, 4717 .getsockopt = packet_getsockopt, 4718 .sendmsg = packet_sendmsg, 4719 .recvmsg = packet_recvmsg, 4720 .mmap = packet_mmap, 4721 }; 4722 4723 static const struct net_proto_family packet_family_ops = { 4724 .family = PF_PACKET, 4725 .create = packet_create, 4726 .owner = THIS_MODULE, 4727 }; 4728 4729 static struct notifier_block packet_netdev_notifier = { 4730 .notifier_call = packet_notifier, 4731 }; 4732 4733 #ifdef CONFIG_PROC_FS 4734 4735 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4736 __acquires(RCU) 4737 { 4738 struct net *net = seq_file_net(seq); 4739 4740 rcu_read_lock(); 4741 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4742 } 4743 4744 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4745 { 4746 struct net *net = seq_file_net(seq); 4747 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4748 } 4749 4750 static void packet_seq_stop(struct seq_file *seq, void *v) 4751 __releases(RCU) 4752 { 4753 rcu_read_unlock(); 4754 } 4755 4756 static int packet_seq_show(struct seq_file *seq, void *v) 4757 { 4758 if (v == SEQ_START_TOKEN) 4759 seq_printf(seq, 4760 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4761 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4762 else { 4763 struct sock *s = sk_entry(v); 4764 const struct packet_sock *po = pkt_sk(s); 4765 4766 seq_printf(seq, 4767 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4768 s, 4769 refcount_read(&s->sk_refcnt), 4770 s->sk_type, 4771 ntohs(READ_ONCE(po->num)), 4772 READ_ONCE(po->ifindex), 4773 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4774 atomic_read(&s->sk_rmem_alloc), 4775 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4776 sock_i_ino(s)); 4777 } 4778 4779 return 0; 4780 } 4781 4782 static const struct seq_operations packet_seq_ops = { 4783 .start = packet_seq_start, 4784 .next = packet_seq_next, 4785 .stop = packet_seq_stop, 4786 .show = packet_seq_show, 4787 }; 4788 #endif 4789 4790 static int __net_init packet_net_init(struct net *net) 4791 { 4792 mutex_init(&net->packet.sklist_lock); 4793 INIT_HLIST_HEAD(&net->packet.sklist); 4794 4795 #ifdef CONFIG_PROC_FS 4796 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4797 sizeof(struct seq_net_private))) 4798 return -ENOMEM; 4799 #endif /* CONFIG_PROC_FS */ 4800 4801 return 0; 4802 } 4803 4804 static void __net_exit packet_net_exit(struct net *net) 4805 { 4806 remove_proc_entry("packet", net->proc_net); 4807 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4808 } 4809 4810 static struct pernet_operations packet_net_ops = { 4811 .init = packet_net_init, 4812 .exit = packet_net_exit, 4813 }; 4814 4815 4816 static void __exit packet_exit(void) 4817 { 4818 sock_unregister(PF_PACKET); 4819 proto_unregister(&packet_proto); 4820 unregister_netdevice_notifier(&packet_netdev_notifier); 4821 unregister_pernet_subsys(&packet_net_ops); 4822 } 4823 4824 static int __init packet_init(void) 4825 { 4826 int rc; 4827 4828 rc = register_pernet_subsys(&packet_net_ops); 4829 if (rc) 4830 goto out; 4831 rc = register_netdevice_notifier(&packet_netdev_notifier); 4832 if (rc) 4833 goto out_pernet; 4834 rc = proto_register(&packet_proto, 0); 4835 if (rc) 4836 goto out_notifier; 4837 rc = sock_register(&packet_family_ops); 4838 if (rc) 4839 goto out_proto; 4840 4841 return 0; 4842 4843 out_proto: 4844 proto_unregister(&packet_proto); 4845 out_notifier: 4846 unregister_netdevice_notifier(&packet_netdev_notifier); 4847 out_pernet: 4848 unregister_pernet_subsys(&packet_net_ops); 4849 out: 4850 return rc; 4851 } 4852 4853 module_init(packet_init); 4854 module_exit(packet_exit); 4855 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4856 MODULE_LICENSE("GPL"); 4857 MODULE_ALIAS_NETPROTO(PF_PACKET); 4858