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(struct sk_buff *skb, struct net_device *dev) 542 { 543 u8 *skb_orig_data = skb->data; 544 int skb_orig_len = skb->len; 545 struct vlan_hdr vhdr, *vh; 546 unsigned int header_len; 547 548 if (!dev) 549 return 0; 550 551 /* In the SOCK_DGRAM scenario, skb data starts at the network 552 * protocol, which is after the VLAN headers. The outer VLAN 553 * header is at the hard_header_len offset in non-variable 554 * length link layer headers. If it's a VLAN device, the 555 * min_header_len should be used to exclude the VLAN header 556 * size. 557 */ 558 if (dev->min_header_len == dev->hard_header_len) 559 header_len = dev->hard_header_len; 560 else if (is_vlan_dev(dev)) 561 header_len = dev->min_header_len; 562 else 563 return 0; 564 565 skb_push(skb, skb->data - skb_mac_header(skb)); 566 vh = skb_header_pointer(skb, header_len, sizeof(vhdr), &vhdr); 567 if (skb_orig_data != skb->data) { 568 skb->data = skb_orig_data; 569 skb->len = skb_orig_len; 570 } 571 if (unlikely(!vh)) 572 return 0; 573 574 return ntohs(vh->h_vlan_TCI); 575 } 576 577 static __be16 vlan_get_protocol_dgram(struct sk_buff *skb) 578 { 579 __be16 proto = skb->protocol; 580 581 if (unlikely(eth_type_vlan(proto))) { 582 u8 *skb_orig_data = skb->data; 583 int skb_orig_len = skb->len; 584 585 skb_push(skb, skb->data - skb_mac_header(skb)); 586 proto = __vlan_get_protocol(skb, proto, NULL); 587 if (skb_orig_data != skb->data) { 588 skb->data = skb_orig_data; 589 skb->len = skb_orig_len; 590 } 591 } 592 593 return proto; 594 } 595 596 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 597 { 598 del_timer_sync(&pkc->retire_blk_timer); 599 } 600 601 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 602 struct sk_buff_head *rb_queue) 603 { 604 struct tpacket_kbdq_core *pkc; 605 606 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 607 608 spin_lock_bh(&rb_queue->lock); 609 pkc->delete_blk_timer = 1; 610 spin_unlock_bh(&rb_queue->lock); 611 612 prb_del_retire_blk_timer(pkc); 613 } 614 615 static void prb_setup_retire_blk_timer(struct packet_sock *po) 616 { 617 struct tpacket_kbdq_core *pkc; 618 619 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 620 timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired, 621 0); 622 pkc->retire_blk_timer.expires = jiffies; 623 } 624 625 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 626 int blk_size_in_bytes) 627 { 628 struct net_device *dev; 629 unsigned int mbits, div; 630 struct ethtool_link_ksettings ecmd; 631 int err; 632 633 rtnl_lock(); 634 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 635 if (unlikely(!dev)) { 636 rtnl_unlock(); 637 return DEFAULT_PRB_RETIRE_TOV; 638 } 639 err = __ethtool_get_link_ksettings(dev, &ecmd); 640 rtnl_unlock(); 641 if (err) 642 return DEFAULT_PRB_RETIRE_TOV; 643 644 /* If the link speed is so slow you don't really 645 * need to worry about perf anyways 646 */ 647 if (ecmd.base.speed < SPEED_1000 || 648 ecmd.base.speed == SPEED_UNKNOWN) 649 return DEFAULT_PRB_RETIRE_TOV; 650 651 div = ecmd.base.speed / 1000; 652 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 653 654 if (div) 655 mbits /= div; 656 657 if (div) 658 return mbits + 1; 659 return mbits; 660 } 661 662 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 663 union tpacket_req_u *req_u) 664 { 665 p1->feature_req_word = req_u->req3.tp_feature_req_word; 666 } 667 668 static void init_prb_bdqc(struct packet_sock *po, 669 struct packet_ring_buffer *rb, 670 struct pgv *pg_vec, 671 union tpacket_req_u *req_u) 672 { 673 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 674 struct tpacket_block_desc *pbd; 675 676 memset(p1, 0x0, sizeof(*p1)); 677 678 p1->knxt_seq_num = 1; 679 p1->pkbdq = pg_vec; 680 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 681 p1->pkblk_start = pg_vec[0].buffer; 682 p1->kblk_size = req_u->req3.tp_block_size; 683 p1->knum_blocks = req_u->req3.tp_block_nr; 684 p1->hdrlen = po->tp_hdrlen; 685 p1->version = po->tp_version; 686 p1->last_kactive_blk_num = 0; 687 po->stats.stats3.tp_freeze_q_cnt = 0; 688 if (req_u->req3.tp_retire_blk_tov) 689 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 690 else 691 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 692 req_u->req3.tp_block_size); 693 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 694 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 695 rwlock_init(&p1->blk_fill_in_prog_lock); 696 697 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 698 prb_init_ft_ops(p1, req_u); 699 prb_setup_retire_blk_timer(po); 700 prb_open_block(p1, pbd); 701 } 702 703 /* Do NOT update the last_blk_num first. 704 * Assumes sk_buff_head lock is held. 705 */ 706 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 707 { 708 mod_timer(&pkc->retire_blk_timer, 709 jiffies + pkc->tov_in_jiffies); 710 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 711 } 712 713 /* 714 * Timer logic: 715 * 1) We refresh the timer only when we open a block. 716 * By doing this we don't waste cycles refreshing the timer 717 * on packet-by-packet basis. 718 * 719 * With a 1MB block-size, on a 1Gbps line, it will take 720 * i) ~8 ms to fill a block + ii) memcpy etc. 721 * In this cut we are not accounting for the memcpy time. 722 * 723 * So, if the user sets the 'tmo' to 10ms then the timer 724 * will never fire while the block is still getting filled 725 * (which is what we want). However, the user could choose 726 * to close a block early and that's fine. 727 * 728 * But when the timer does fire, we check whether or not to refresh it. 729 * Since the tmo granularity is in msecs, it is not too expensive 730 * to refresh the timer, lets say every '8' msecs. 731 * Either the user can set the 'tmo' or we can derive it based on 732 * a) line-speed and b) block-size. 733 * prb_calc_retire_blk_tmo() calculates the tmo. 734 * 735 */ 736 static void prb_retire_rx_blk_timer_expired(struct timer_list *t) 737 { 738 struct packet_sock *po = 739 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer); 740 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 741 unsigned int frozen; 742 struct tpacket_block_desc *pbd; 743 744 spin_lock(&po->sk.sk_receive_queue.lock); 745 746 frozen = prb_queue_frozen(pkc); 747 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 748 749 if (unlikely(pkc->delete_blk_timer)) 750 goto out; 751 752 /* We only need to plug the race when the block is partially filled. 753 * tpacket_rcv: 754 * lock(); increment BLOCK_NUM_PKTS; unlock() 755 * copy_bits() is in progress ... 756 * timer fires on other cpu: 757 * we can't retire the current block because copy_bits 758 * is in progress. 759 * 760 */ 761 if (BLOCK_NUM_PKTS(pbd)) { 762 /* Waiting for skb_copy_bits to finish... */ 763 write_lock(&pkc->blk_fill_in_prog_lock); 764 write_unlock(&pkc->blk_fill_in_prog_lock); 765 } 766 767 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 768 if (!frozen) { 769 if (!BLOCK_NUM_PKTS(pbd)) { 770 /* An empty block. Just refresh the timer. */ 771 goto refresh_timer; 772 } 773 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 774 if (!prb_dispatch_next_block(pkc, po)) 775 goto refresh_timer; 776 else 777 goto out; 778 } else { 779 /* Case 1. Queue was frozen because user-space was 780 * lagging behind. 781 */ 782 if (prb_curr_blk_in_use(pbd)) { 783 /* 784 * Ok, user-space is still behind. 785 * So just refresh the timer. 786 */ 787 goto refresh_timer; 788 } else { 789 /* Case 2. queue was frozen,user-space caught up, 790 * now the link went idle && the timer fired. 791 * We don't have a block to close.So we open this 792 * block and restart the timer. 793 * opening a block thaws the queue,restarts timer 794 * Thawing/timer-refresh is a side effect. 795 */ 796 prb_open_block(pkc, pbd); 797 goto out; 798 } 799 } 800 } 801 802 refresh_timer: 803 _prb_refresh_rx_retire_blk_timer(pkc); 804 805 out: 806 spin_unlock(&po->sk.sk_receive_queue.lock); 807 } 808 809 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 810 struct tpacket_block_desc *pbd1, __u32 status) 811 { 812 /* Flush everything minus the block header */ 813 814 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 815 u8 *start, *end; 816 817 start = (u8 *)pbd1; 818 819 /* Skip the block header(we know header WILL fit in 4K) */ 820 start += PAGE_SIZE; 821 822 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 823 for (; start < end; start += PAGE_SIZE) 824 flush_dcache_page(pgv_to_page(start)); 825 826 smp_wmb(); 827 #endif 828 829 /* Now update the block status. */ 830 831 BLOCK_STATUS(pbd1) = status; 832 833 /* Flush the block header */ 834 835 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 836 start = (u8 *)pbd1; 837 flush_dcache_page(pgv_to_page(start)); 838 839 smp_wmb(); 840 #endif 841 } 842 843 /* 844 * Side effect: 845 * 846 * 1) flush the block 847 * 2) Increment active_blk_num 848 * 849 * Note:We DONT refresh the timer on purpose. 850 * Because almost always the next block will be opened. 851 */ 852 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 853 struct tpacket_block_desc *pbd1, 854 struct packet_sock *po, unsigned int stat) 855 { 856 __u32 status = TP_STATUS_USER | stat; 857 858 struct tpacket3_hdr *last_pkt; 859 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 860 struct sock *sk = &po->sk; 861 862 if (atomic_read(&po->tp_drops)) 863 status |= TP_STATUS_LOSING; 864 865 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 866 last_pkt->tp_next_offset = 0; 867 868 /* Get the ts of the last pkt */ 869 if (BLOCK_NUM_PKTS(pbd1)) { 870 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 871 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 872 } else { 873 /* Ok, we tmo'd - so get the current time. 874 * 875 * It shouldn't really happen as we don't close empty 876 * blocks. See prb_retire_rx_blk_timer_expired(). 877 */ 878 struct timespec64 ts; 879 ktime_get_real_ts64(&ts); 880 h1->ts_last_pkt.ts_sec = ts.tv_sec; 881 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 882 } 883 884 smp_wmb(); 885 886 /* Flush the block */ 887 prb_flush_block(pkc1, pbd1, status); 888 889 sk->sk_data_ready(sk); 890 891 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 892 } 893 894 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 895 { 896 pkc->reset_pending_on_curr_blk = 0; 897 } 898 899 /* 900 * Side effect of opening a block: 901 * 902 * 1) prb_queue is thawed. 903 * 2) retire_blk_timer is refreshed. 904 * 905 */ 906 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 907 struct tpacket_block_desc *pbd1) 908 { 909 struct timespec64 ts; 910 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 911 912 smp_rmb(); 913 914 /* We could have just memset this but we will lose the 915 * flexibility of making the priv area sticky 916 */ 917 918 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 919 BLOCK_NUM_PKTS(pbd1) = 0; 920 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 921 922 ktime_get_real_ts64(&ts); 923 924 h1->ts_first_pkt.ts_sec = ts.tv_sec; 925 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 926 927 pkc1->pkblk_start = (char *)pbd1; 928 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 929 930 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 931 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 932 933 pbd1->version = pkc1->version; 934 pkc1->prev = pkc1->nxt_offset; 935 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 936 937 prb_thaw_queue(pkc1); 938 _prb_refresh_rx_retire_blk_timer(pkc1); 939 940 smp_wmb(); 941 } 942 943 /* 944 * Queue freeze logic: 945 * 1) Assume tp_block_nr = 8 blocks. 946 * 2) At time 't0', user opens Rx ring. 947 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 948 * 4) user-space is either sleeping or processing block '0'. 949 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 950 * it will close block-7,loop around and try to fill block '0'. 951 * call-flow: 952 * __packet_lookup_frame_in_block 953 * prb_retire_current_block() 954 * prb_dispatch_next_block() 955 * |->(BLOCK_STATUS == USER) evaluates to true 956 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 957 * 6) Now there are two cases: 958 * 6.1) Link goes idle right after the queue is frozen. 959 * But remember, the last open_block() refreshed the timer. 960 * When this timer expires,it will refresh itself so that we can 961 * re-open block-0 in near future. 962 * 6.2) Link is busy and keeps on receiving packets. This is a simple 963 * case and __packet_lookup_frame_in_block will check if block-0 964 * is free and can now be re-used. 965 */ 966 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 967 struct packet_sock *po) 968 { 969 pkc->reset_pending_on_curr_blk = 1; 970 po->stats.stats3.tp_freeze_q_cnt++; 971 } 972 973 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 974 975 /* 976 * If the next block is free then we will dispatch it 977 * and return a good offset. 978 * Else, we will freeze the queue. 979 * So, caller must check the return value. 980 */ 981 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 982 struct packet_sock *po) 983 { 984 struct tpacket_block_desc *pbd; 985 986 smp_rmb(); 987 988 /* 1. Get current block num */ 989 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 990 991 /* 2. If this block is currently in_use then freeze the queue */ 992 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 993 prb_freeze_queue(pkc, po); 994 return NULL; 995 } 996 997 /* 998 * 3. 999 * open this block and return the offset where the first packet 1000 * needs to get stored. 1001 */ 1002 prb_open_block(pkc, pbd); 1003 return (void *)pkc->nxt_offset; 1004 } 1005 1006 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 1007 struct packet_sock *po, unsigned int status) 1008 { 1009 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1010 1011 /* retire/close the current block */ 1012 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 1013 /* 1014 * Plug the case where copy_bits() is in progress on 1015 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 1016 * have space to copy the pkt in the current block and 1017 * called prb_retire_current_block() 1018 * 1019 * We don't need to worry about the TMO case because 1020 * the timer-handler already handled this case. 1021 */ 1022 if (!(status & TP_STATUS_BLK_TMO)) { 1023 /* Waiting for skb_copy_bits to finish... */ 1024 write_lock(&pkc->blk_fill_in_prog_lock); 1025 write_unlock(&pkc->blk_fill_in_prog_lock); 1026 } 1027 prb_close_block(pkc, pbd, po, status); 1028 return; 1029 } 1030 } 1031 1032 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) 1033 { 1034 return TP_STATUS_USER & BLOCK_STATUS(pbd); 1035 } 1036 1037 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 1038 { 1039 return pkc->reset_pending_on_curr_blk; 1040 } 1041 1042 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 1043 __releases(&pkc->blk_fill_in_prog_lock) 1044 { 1045 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1046 1047 read_unlock(&pkc->blk_fill_in_prog_lock); 1048 } 1049 1050 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 1051 struct tpacket3_hdr *ppd) 1052 { 1053 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 1054 } 1055 1056 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 1057 struct tpacket3_hdr *ppd) 1058 { 1059 ppd->hv1.tp_rxhash = 0; 1060 } 1061 1062 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 1063 struct tpacket3_hdr *ppd) 1064 { 1065 struct packet_sock *po = container_of(pkc, struct packet_sock, rx_ring.prb_bdqc); 1066 1067 if (skb_vlan_tag_present(pkc->skb)) { 1068 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1069 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1070 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1071 } else if (unlikely(po->sk.sk_type == SOCK_DGRAM && eth_type_vlan(pkc->skb->protocol))) { 1072 ppd->hv1.tp_vlan_tci = vlan_get_tci(pkc->skb, pkc->skb->dev); 1073 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->protocol); 1074 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1075 } else { 1076 ppd->hv1.tp_vlan_tci = 0; 1077 ppd->hv1.tp_vlan_tpid = 0; 1078 ppd->tp_status = TP_STATUS_AVAILABLE; 1079 } 1080 } 1081 1082 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1083 struct tpacket3_hdr *ppd) 1084 { 1085 ppd->hv1.tp_padding = 0; 1086 prb_fill_vlan_info(pkc, ppd); 1087 1088 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1089 prb_fill_rxhash(pkc, ppd); 1090 else 1091 prb_clear_rxhash(pkc, ppd); 1092 } 1093 1094 static void prb_fill_curr_block(char *curr, 1095 struct tpacket_kbdq_core *pkc, 1096 struct tpacket_block_desc *pbd, 1097 unsigned int len) 1098 __acquires(&pkc->blk_fill_in_prog_lock) 1099 { 1100 struct tpacket3_hdr *ppd; 1101 1102 ppd = (struct tpacket3_hdr *)curr; 1103 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1104 pkc->prev = curr; 1105 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1106 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1107 BLOCK_NUM_PKTS(pbd) += 1; 1108 read_lock(&pkc->blk_fill_in_prog_lock); 1109 prb_run_all_ft_ops(pkc, ppd); 1110 } 1111 1112 /* Assumes caller has the sk->rx_queue.lock */ 1113 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1114 struct sk_buff *skb, 1115 unsigned int len 1116 ) 1117 { 1118 struct tpacket_kbdq_core *pkc; 1119 struct tpacket_block_desc *pbd; 1120 char *curr, *end; 1121 1122 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1123 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1124 1125 /* Queue is frozen when user space is lagging behind */ 1126 if (prb_queue_frozen(pkc)) { 1127 /* 1128 * Check if that last block which caused the queue to freeze, 1129 * is still in_use by user-space. 1130 */ 1131 if (prb_curr_blk_in_use(pbd)) { 1132 /* Can't record this packet */ 1133 return NULL; 1134 } else { 1135 /* 1136 * Ok, the block was released by user-space. 1137 * Now let's open that block. 1138 * opening a block also thaws the queue. 1139 * Thawing is a side effect. 1140 */ 1141 prb_open_block(pkc, pbd); 1142 } 1143 } 1144 1145 smp_mb(); 1146 curr = pkc->nxt_offset; 1147 pkc->skb = skb; 1148 end = (char *)pbd + pkc->kblk_size; 1149 1150 /* first try the current block */ 1151 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1152 prb_fill_curr_block(curr, pkc, pbd, len); 1153 return (void *)curr; 1154 } 1155 1156 /* Ok, close the current block */ 1157 prb_retire_current_block(pkc, po, 0); 1158 1159 /* Now, try to dispatch the next block */ 1160 curr = (char *)prb_dispatch_next_block(pkc, po); 1161 if (curr) { 1162 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1163 prb_fill_curr_block(curr, pkc, pbd, len); 1164 return (void *)curr; 1165 } 1166 1167 /* 1168 * No free blocks are available.user_space hasn't caught up yet. 1169 * Queue was just frozen and now this packet will get dropped. 1170 */ 1171 return NULL; 1172 } 1173 1174 static void *packet_current_rx_frame(struct packet_sock *po, 1175 struct sk_buff *skb, 1176 int status, unsigned int len) 1177 { 1178 char *curr = NULL; 1179 switch (po->tp_version) { 1180 case TPACKET_V1: 1181 case TPACKET_V2: 1182 curr = packet_lookup_frame(po, &po->rx_ring, 1183 po->rx_ring.head, status); 1184 return curr; 1185 case TPACKET_V3: 1186 return __packet_lookup_frame_in_block(po, skb, len); 1187 default: 1188 WARN(1, "TPACKET version not supported\n"); 1189 BUG(); 1190 return NULL; 1191 } 1192 } 1193 1194 static void *prb_lookup_block(const struct packet_sock *po, 1195 const struct packet_ring_buffer *rb, 1196 unsigned int idx, 1197 int status) 1198 { 1199 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1200 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1201 1202 if (status != BLOCK_STATUS(pbd)) 1203 return NULL; 1204 return pbd; 1205 } 1206 1207 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1208 { 1209 unsigned int prev; 1210 if (rb->prb_bdqc.kactive_blk_num) 1211 prev = rb->prb_bdqc.kactive_blk_num-1; 1212 else 1213 prev = rb->prb_bdqc.knum_blocks-1; 1214 return prev; 1215 } 1216 1217 /* Assumes caller has held the rx_queue.lock */ 1218 static void *__prb_previous_block(struct packet_sock *po, 1219 struct packet_ring_buffer *rb, 1220 int status) 1221 { 1222 unsigned int previous = prb_previous_blk_num(rb); 1223 return prb_lookup_block(po, rb, previous, status); 1224 } 1225 1226 static void *packet_previous_rx_frame(struct packet_sock *po, 1227 struct packet_ring_buffer *rb, 1228 int status) 1229 { 1230 if (po->tp_version <= TPACKET_V2) 1231 return packet_previous_frame(po, rb, status); 1232 1233 return __prb_previous_block(po, rb, status); 1234 } 1235 1236 static void packet_increment_rx_head(struct packet_sock *po, 1237 struct packet_ring_buffer *rb) 1238 { 1239 switch (po->tp_version) { 1240 case TPACKET_V1: 1241 case TPACKET_V2: 1242 return packet_increment_head(rb); 1243 case TPACKET_V3: 1244 default: 1245 WARN(1, "TPACKET version not supported.\n"); 1246 BUG(); 1247 return; 1248 } 1249 } 1250 1251 static void *packet_previous_frame(struct packet_sock *po, 1252 struct packet_ring_buffer *rb, 1253 int status) 1254 { 1255 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1256 return packet_lookup_frame(po, rb, previous, status); 1257 } 1258 1259 static void packet_increment_head(struct packet_ring_buffer *buff) 1260 { 1261 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1262 } 1263 1264 static void packet_inc_pending(struct packet_ring_buffer *rb) 1265 { 1266 this_cpu_inc(*rb->pending_refcnt); 1267 } 1268 1269 static void packet_dec_pending(struct packet_ring_buffer *rb) 1270 { 1271 this_cpu_dec(*rb->pending_refcnt); 1272 } 1273 1274 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1275 { 1276 unsigned int refcnt = 0; 1277 int cpu; 1278 1279 /* We don't use pending refcount in rx_ring. */ 1280 if (rb->pending_refcnt == NULL) 1281 return 0; 1282 1283 for_each_possible_cpu(cpu) 1284 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1285 1286 return refcnt; 1287 } 1288 1289 static int packet_alloc_pending(struct packet_sock *po) 1290 { 1291 po->rx_ring.pending_refcnt = NULL; 1292 1293 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1294 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1295 return -ENOBUFS; 1296 1297 return 0; 1298 } 1299 1300 static void packet_free_pending(struct packet_sock *po) 1301 { 1302 free_percpu(po->tx_ring.pending_refcnt); 1303 } 1304 1305 #define ROOM_POW_OFF 2 1306 #define ROOM_NONE 0x0 1307 #define ROOM_LOW 0x1 1308 #define ROOM_NORMAL 0x2 1309 1310 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) 1311 { 1312 int idx, len; 1313 1314 len = READ_ONCE(po->rx_ring.frame_max) + 1; 1315 idx = READ_ONCE(po->rx_ring.head); 1316 if (pow_off) 1317 idx += len >> pow_off; 1318 if (idx >= len) 1319 idx -= len; 1320 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1321 } 1322 1323 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) 1324 { 1325 int idx, len; 1326 1327 len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); 1328 idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); 1329 if (pow_off) 1330 idx += len >> pow_off; 1331 if (idx >= len) 1332 idx -= len; 1333 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1334 } 1335 1336 static int __packet_rcv_has_room(const struct packet_sock *po, 1337 const struct sk_buff *skb) 1338 { 1339 const struct sock *sk = &po->sk; 1340 int ret = ROOM_NONE; 1341 1342 if (po->prot_hook.func != tpacket_rcv) { 1343 int rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1344 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1345 - (skb ? skb->truesize : 0); 1346 1347 if (avail > (rcvbuf >> ROOM_POW_OFF)) 1348 return ROOM_NORMAL; 1349 else if (avail > 0) 1350 return ROOM_LOW; 1351 else 1352 return ROOM_NONE; 1353 } 1354 1355 if (po->tp_version == TPACKET_V3) { 1356 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1357 ret = ROOM_NORMAL; 1358 else if (__tpacket_v3_has_room(po, 0)) 1359 ret = ROOM_LOW; 1360 } else { 1361 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1362 ret = ROOM_NORMAL; 1363 else if (__tpacket_has_room(po, 0)) 1364 ret = ROOM_LOW; 1365 } 1366 1367 return ret; 1368 } 1369 1370 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1371 { 1372 bool pressure; 1373 int ret; 1374 1375 ret = __packet_rcv_has_room(po, skb); 1376 pressure = ret != ROOM_NORMAL; 1377 1378 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure) 1379 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure); 1380 1381 return ret; 1382 } 1383 1384 static void packet_rcv_try_clear_pressure(struct packet_sock *po) 1385 { 1386 if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) && 1387 __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 1388 packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false); 1389 } 1390 1391 static void packet_sock_destruct(struct sock *sk) 1392 { 1393 skb_queue_purge(&sk->sk_error_queue); 1394 1395 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1396 WARN_ON(refcount_read(&sk->sk_wmem_alloc)); 1397 1398 if (!sock_flag(sk, SOCK_DEAD)) { 1399 pr_err("Attempt to release alive packet socket: %p\n", sk); 1400 return; 1401 } 1402 } 1403 1404 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1405 { 1406 u32 *history = po->rollover->history; 1407 u32 victim, rxhash; 1408 int i, count = 0; 1409 1410 rxhash = skb_get_hash(skb); 1411 for (i = 0; i < ROLLOVER_HLEN; i++) 1412 if (READ_ONCE(history[i]) == rxhash) 1413 count++; 1414 1415 victim = get_random_u32_below(ROLLOVER_HLEN); 1416 1417 /* Avoid dirtying the cache line if possible */ 1418 if (READ_ONCE(history[victim]) != rxhash) 1419 WRITE_ONCE(history[victim], rxhash); 1420 1421 return count > (ROLLOVER_HLEN >> 1); 1422 } 1423 1424 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1425 struct sk_buff *skb, 1426 unsigned int num) 1427 { 1428 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1429 } 1430 1431 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1432 struct sk_buff *skb, 1433 unsigned int num) 1434 { 1435 unsigned int val = atomic_inc_return(&f->rr_cur); 1436 1437 return val % num; 1438 } 1439 1440 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1441 struct sk_buff *skb, 1442 unsigned int num) 1443 { 1444 return smp_processor_id() % num; 1445 } 1446 1447 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1448 struct sk_buff *skb, 1449 unsigned int num) 1450 { 1451 return get_random_u32_below(num); 1452 } 1453 1454 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1455 struct sk_buff *skb, 1456 unsigned int idx, bool try_self, 1457 unsigned int num) 1458 { 1459 struct packet_sock *po, *po_next, *po_skip = NULL; 1460 unsigned int i, j, room = ROOM_NONE; 1461 1462 po = pkt_sk(rcu_dereference(f->arr[idx])); 1463 1464 if (try_self) { 1465 room = packet_rcv_has_room(po, skb); 1466 if (room == ROOM_NORMAL || 1467 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1468 return idx; 1469 po_skip = po; 1470 } 1471 1472 i = j = min_t(int, po->rollover->sock, num - 1); 1473 do { 1474 po_next = pkt_sk(rcu_dereference(f->arr[i])); 1475 if (po_next != po_skip && 1476 !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) && 1477 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1478 if (i != j) 1479 po->rollover->sock = i; 1480 atomic_long_inc(&po->rollover->num); 1481 if (room == ROOM_LOW) 1482 atomic_long_inc(&po->rollover->num_huge); 1483 return i; 1484 } 1485 1486 if (++i == num) 1487 i = 0; 1488 } while (i != j); 1489 1490 atomic_long_inc(&po->rollover->num_failed); 1491 return idx; 1492 } 1493 1494 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1495 struct sk_buff *skb, 1496 unsigned int num) 1497 { 1498 return skb_get_queue_mapping(skb) % num; 1499 } 1500 1501 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1502 struct sk_buff *skb, 1503 unsigned int num) 1504 { 1505 struct bpf_prog *prog; 1506 unsigned int ret = 0; 1507 1508 rcu_read_lock(); 1509 prog = rcu_dereference(f->bpf_prog); 1510 if (prog) 1511 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1512 rcu_read_unlock(); 1513 1514 return ret; 1515 } 1516 1517 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1518 { 1519 return f->flags & (flag >> 8); 1520 } 1521 1522 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1523 struct packet_type *pt, struct net_device *orig_dev) 1524 { 1525 struct packet_fanout *f = pt->af_packet_priv; 1526 unsigned int num = READ_ONCE(f->num_members); 1527 struct net *net = read_pnet(&f->net); 1528 struct packet_sock *po; 1529 unsigned int idx; 1530 1531 if (!net_eq(dev_net(dev), net) || !num) { 1532 kfree_skb(skb); 1533 return 0; 1534 } 1535 1536 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1537 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1538 if (!skb) 1539 return 0; 1540 } 1541 switch (f->type) { 1542 case PACKET_FANOUT_HASH: 1543 default: 1544 idx = fanout_demux_hash(f, skb, num); 1545 break; 1546 case PACKET_FANOUT_LB: 1547 idx = fanout_demux_lb(f, skb, num); 1548 break; 1549 case PACKET_FANOUT_CPU: 1550 idx = fanout_demux_cpu(f, skb, num); 1551 break; 1552 case PACKET_FANOUT_RND: 1553 idx = fanout_demux_rnd(f, skb, num); 1554 break; 1555 case PACKET_FANOUT_QM: 1556 idx = fanout_demux_qm(f, skb, num); 1557 break; 1558 case PACKET_FANOUT_ROLLOVER: 1559 idx = fanout_demux_rollover(f, skb, 0, false, num); 1560 break; 1561 case PACKET_FANOUT_CBPF: 1562 case PACKET_FANOUT_EBPF: 1563 idx = fanout_demux_bpf(f, skb, num); 1564 break; 1565 } 1566 1567 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1568 idx = fanout_demux_rollover(f, skb, idx, true, num); 1569 1570 po = pkt_sk(rcu_dereference(f->arr[idx])); 1571 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1572 } 1573 1574 DEFINE_MUTEX(fanout_mutex); 1575 EXPORT_SYMBOL_GPL(fanout_mutex); 1576 static LIST_HEAD(fanout_list); 1577 static u16 fanout_next_id; 1578 1579 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1580 { 1581 struct packet_fanout *f = po->fanout; 1582 1583 spin_lock(&f->lock); 1584 rcu_assign_pointer(f->arr[f->num_members], sk); 1585 smp_wmb(); 1586 f->num_members++; 1587 if (f->num_members == 1) 1588 dev_add_pack(&f->prot_hook); 1589 spin_unlock(&f->lock); 1590 } 1591 1592 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1593 { 1594 struct packet_fanout *f = po->fanout; 1595 int i; 1596 1597 spin_lock(&f->lock); 1598 for (i = 0; i < f->num_members; i++) { 1599 if (rcu_dereference_protected(f->arr[i], 1600 lockdep_is_held(&f->lock)) == sk) 1601 break; 1602 } 1603 BUG_ON(i >= f->num_members); 1604 rcu_assign_pointer(f->arr[i], 1605 rcu_dereference_protected(f->arr[f->num_members - 1], 1606 lockdep_is_held(&f->lock))); 1607 f->num_members--; 1608 if (f->num_members == 0) 1609 __dev_remove_pack(&f->prot_hook); 1610 spin_unlock(&f->lock); 1611 } 1612 1613 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1614 { 1615 if (sk->sk_family != PF_PACKET) 1616 return false; 1617 1618 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1619 } 1620 1621 static void fanout_init_data(struct packet_fanout *f) 1622 { 1623 switch (f->type) { 1624 case PACKET_FANOUT_LB: 1625 atomic_set(&f->rr_cur, 0); 1626 break; 1627 case PACKET_FANOUT_CBPF: 1628 case PACKET_FANOUT_EBPF: 1629 RCU_INIT_POINTER(f->bpf_prog, NULL); 1630 break; 1631 } 1632 } 1633 1634 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1635 { 1636 struct bpf_prog *old; 1637 1638 spin_lock(&f->lock); 1639 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1640 rcu_assign_pointer(f->bpf_prog, new); 1641 spin_unlock(&f->lock); 1642 1643 if (old) { 1644 synchronize_net(); 1645 bpf_prog_destroy(old); 1646 } 1647 } 1648 1649 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, 1650 unsigned int len) 1651 { 1652 struct bpf_prog *new; 1653 struct sock_fprog fprog; 1654 int ret; 1655 1656 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1657 return -EPERM; 1658 1659 ret = copy_bpf_fprog_from_user(&fprog, data, len); 1660 if (ret) 1661 return ret; 1662 1663 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1664 if (ret) 1665 return ret; 1666 1667 __fanout_set_data_bpf(po->fanout, new); 1668 return 0; 1669 } 1670 1671 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, 1672 unsigned int len) 1673 { 1674 struct bpf_prog *new; 1675 u32 fd; 1676 1677 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1678 return -EPERM; 1679 if (len != sizeof(fd)) 1680 return -EINVAL; 1681 if (copy_from_sockptr(&fd, data, len)) 1682 return -EFAULT; 1683 1684 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1685 if (IS_ERR(new)) 1686 return PTR_ERR(new); 1687 1688 __fanout_set_data_bpf(po->fanout, new); 1689 return 0; 1690 } 1691 1692 static int fanout_set_data(struct packet_sock *po, sockptr_t data, 1693 unsigned int len) 1694 { 1695 switch (po->fanout->type) { 1696 case PACKET_FANOUT_CBPF: 1697 return fanout_set_data_cbpf(po, data, len); 1698 case PACKET_FANOUT_EBPF: 1699 return fanout_set_data_ebpf(po, data, len); 1700 default: 1701 return -EINVAL; 1702 } 1703 } 1704 1705 static void fanout_release_data(struct packet_fanout *f) 1706 { 1707 switch (f->type) { 1708 case PACKET_FANOUT_CBPF: 1709 case PACKET_FANOUT_EBPF: 1710 __fanout_set_data_bpf(f, NULL); 1711 } 1712 } 1713 1714 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) 1715 { 1716 struct packet_fanout *f; 1717 1718 list_for_each_entry(f, &fanout_list, list) { 1719 if (f->id == candidate_id && 1720 read_pnet(&f->net) == sock_net(sk)) { 1721 return false; 1722 } 1723 } 1724 return true; 1725 } 1726 1727 static bool fanout_find_new_id(struct sock *sk, u16 *new_id) 1728 { 1729 u16 id = fanout_next_id; 1730 1731 do { 1732 if (__fanout_id_is_free(sk, id)) { 1733 *new_id = id; 1734 fanout_next_id = id + 1; 1735 return true; 1736 } 1737 1738 id++; 1739 } while (id != fanout_next_id); 1740 1741 return false; 1742 } 1743 1744 static int fanout_add(struct sock *sk, struct fanout_args *args) 1745 { 1746 struct packet_rollover *rollover = NULL; 1747 struct packet_sock *po = pkt_sk(sk); 1748 u16 type_flags = args->type_flags; 1749 struct packet_fanout *f, *match; 1750 u8 type = type_flags & 0xff; 1751 u8 flags = type_flags >> 8; 1752 u16 id = args->id; 1753 int err; 1754 1755 switch (type) { 1756 case PACKET_FANOUT_ROLLOVER: 1757 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1758 return -EINVAL; 1759 break; 1760 case PACKET_FANOUT_HASH: 1761 case PACKET_FANOUT_LB: 1762 case PACKET_FANOUT_CPU: 1763 case PACKET_FANOUT_RND: 1764 case PACKET_FANOUT_QM: 1765 case PACKET_FANOUT_CBPF: 1766 case PACKET_FANOUT_EBPF: 1767 break; 1768 default: 1769 return -EINVAL; 1770 } 1771 1772 mutex_lock(&fanout_mutex); 1773 1774 err = -EALREADY; 1775 if (po->fanout) 1776 goto out; 1777 1778 if (type == PACKET_FANOUT_ROLLOVER || 1779 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1780 err = -ENOMEM; 1781 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); 1782 if (!rollover) 1783 goto out; 1784 atomic_long_set(&rollover->num, 0); 1785 atomic_long_set(&rollover->num_huge, 0); 1786 atomic_long_set(&rollover->num_failed, 0); 1787 } 1788 1789 if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { 1790 if (id != 0) { 1791 err = -EINVAL; 1792 goto out; 1793 } 1794 if (!fanout_find_new_id(sk, &id)) { 1795 err = -ENOMEM; 1796 goto out; 1797 } 1798 /* ephemeral flag for the first socket in the group: drop it */ 1799 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); 1800 } 1801 1802 match = NULL; 1803 list_for_each_entry(f, &fanout_list, list) { 1804 if (f->id == id && 1805 read_pnet(&f->net) == sock_net(sk)) { 1806 match = f; 1807 break; 1808 } 1809 } 1810 err = -EINVAL; 1811 if (match) { 1812 if (match->flags != flags) 1813 goto out; 1814 if (args->max_num_members && 1815 args->max_num_members != match->max_num_members) 1816 goto out; 1817 } else { 1818 if (args->max_num_members > PACKET_FANOUT_MAX) 1819 goto out; 1820 if (!args->max_num_members) 1821 /* legacy PACKET_FANOUT_MAX */ 1822 args->max_num_members = 256; 1823 err = -ENOMEM; 1824 match = kvzalloc(struct_size(match, arr, args->max_num_members), 1825 GFP_KERNEL); 1826 if (!match) 1827 goto out; 1828 write_pnet(&match->net, sock_net(sk)); 1829 match->id = id; 1830 match->type = type; 1831 match->flags = flags; 1832 INIT_LIST_HEAD(&match->list); 1833 spin_lock_init(&match->lock); 1834 refcount_set(&match->sk_ref, 0); 1835 fanout_init_data(match); 1836 match->prot_hook.type = po->prot_hook.type; 1837 match->prot_hook.dev = po->prot_hook.dev; 1838 match->prot_hook.func = packet_rcv_fanout; 1839 match->prot_hook.af_packet_priv = match; 1840 match->prot_hook.af_packet_net = read_pnet(&match->net); 1841 match->prot_hook.id_match = match_fanout_group; 1842 match->max_num_members = args->max_num_members; 1843 match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; 1844 list_add(&match->list, &fanout_list); 1845 } 1846 err = -EINVAL; 1847 1848 spin_lock(&po->bind_lock); 1849 if (po->num && 1850 match->type == type && 1851 match->prot_hook.type == po->prot_hook.type && 1852 match->prot_hook.dev == po->prot_hook.dev) { 1853 err = -ENOSPC; 1854 if (refcount_read(&match->sk_ref) < match->max_num_members) { 1855 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1856 WRITE_ONCE(po->fanout, match); 1857 1858 po->rollover = rollover; 1859 rollover = NULL; 1860 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1861 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 1862 __dev_remove_pack(&po->prot_hook); 1863 __fanout_link(sk, po); 1864 } 1865 err = 0; 1866 } 1867 } 1868 spin_unlock(&po->bind_lock); 1869 1870 if (err && !refcount_read(&match->sk_ref)) { 1871 list_del(&match->list); 1872 kvfree(match); 1873 } 1874 1875 out: 1876 kfree(rollover); 1877 mutex_unlock(&fanout_mutex); 1878 return err; 1879 } 1880 1881 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1882 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1883 * It is the responsibility of the caller to call fanout_release_data() and 1884 * free the returned packet_fanout (after synchronize_net()) 1885 */ 1886 static struct packet_fanout *fanout_release(struct sock *sk) 1887 { 1888 struct packet_sock *po = pkt_sk(sk); 1889 struct packet_fanout *f; 1890 1891 mutex_lock(&fanout_mutex); 1892 f = po->fanout; 1893 if (f) { 1894 po->fanout = NULL; 1895 1896 if (refcount_dec_and_test(&f->sk_ref)) 1897 list_del(&f->list); 1898 else 1899 f = NULL; 1900 } 1901 mutex_unlock(&fanout_mutex); 1902 1903 return f; 1904 } 1905 1906 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1907 struct sk_buff *skb) 1908 { 1909 /* Earlier code assumed this would be a VLAN pkt, double-check 1910 * this now that we have the actual packet in hand. We can only 1911 * do this check on Ethernet devices. 1912 */ 1913 if (unlikely(dev->type != ARPHRD_ETHER)) 1914 return false; 1915 1916 skb_reset_mac_header(skb); 1917 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1918 } 1919 1920 static const struct proto_ops packet_ops; 1921 1922 static const struct proto_ops packet_ops_spkt; 1923 1924 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1925 struct packet_type *pt, struct net_device *orig_dev) 1926 { 1927 struct sock *sk; 1928 struct sockaddr_pkt *spkt; 1929 1930 /* 1931 * When we registered the protocol we saved the socket in the data 1932 * field for just this event. 1933 */ 1934 1935 sk = pt->af_packet_priv; 1936 1937 /* 1938 * Yank back the headers [hope the device set this 1939 * right or kerboom...] 1940 * 1941 * Incoming packets have ll header pulled, 1942 * push it back. 1943 * 1944 * For outgoing ones skb->data == skb_mac_header(skb) 1945 * so that this procedure is noop. 1946 */ 1947 1948 if (skb->pkt_type == PACKET_LOOPBACK) 1949 goto out; 1950 1951 if (!net_eq(dev_net(dev), sock_net(sk))) 1952 goto out; 1953 1954 skb = skb_share_check(skb, GFP_ATOMIC); 1955 if (skb == NULL) 1956 goto oom; 1957 1958 /* drop any routing info */ 1959 skb_dst_drop(skb); 1960 1961 /* drop conntrack reference */ 1962 nf_reset_ct(skb); 1963 1964 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1965 1966 skb_push(skb, skb->data - skb_mac_header(skb)); 1967 1968 /* 1969 * The SOCK_PACKET socket receives _all_ frames. 1970 */ 1971 1972 spkt->spkt_family = dev->type; 1973 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1974 spkt->spkt_protocol = skb->protocol; 1975 1976 /* 1977 * Charge the memory to the socket. This is done specifically 1978 * to prevent sockets using all the memory up. 1979 */ 1980 1981 if (sock_queue_rcv_skb(sk, skb) == 0) 1982 return 0; 1983 1984 out: 1985 kfree_skb(skb); 1986 oom: 1987 return 0; 1988 } 1989 1990 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1991 { 1992 int depth; 1993 1994 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1995 sock->type == SOCK_RAW) { 1996 skb_reset_mac_header(skb); 1997 skb->protocol = dev_parse_header_protocol(skb); 1998 } 1999 2000 /* Move network header to the right position for VLAN tagged packets */ 2001 if (likely(skb->dev->type == ARPHRD_ETHER) && 2002 eth_type_vlan(skb->protocol) && 2003 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 2004 skb_set_network_header(skb, depth); 2005 2006 skb_probe_transport_header(skb); 2007 } 2008 2009 /* 2010 * Output a raw packet to a device layer. This bypasses all the other 2011 * protocol layers and you must therefore supply it with a complete frame 2012 */ 2013 2014 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 2015 size_t len) 2016 { 2017 struct sock *sk = sock->sk; 2018 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 2019 struct sk_buff *skb = NULL; 2020 struct net_device *dev; 2021 struct sockcm_cookie sockc; 2022 __be16 proto = 0; 2023 int err; 2024 int extra_len = 0; 2025 2026 /* 2027 * Get and verify the address. 2028 */ 2029 2030 if (saddr) { 2031 if (msg->msg_namelen < sizeof(struct sockaddr)) 2032 return -EINVAL; 2033 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 2034 proto = saddr->spkt_protocol; 2035 } else 2036 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 2037 2038 /* 2039 * Find the device first to size check it 2040 */ 2041 2042 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 2043 retry: 2044 rcu_read_lock(); 2045 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 2046 err = -ENODEV; 2047 if (dev == NULL) 2048 goto out_unlock; 2049 2050 err = -ENETDOWN; 2051 if (!(dev->flags & IFF_UP)) 2052 goto out_unlock; 2053 2054 /* 2055 * You may not queue a frame bigger than the mtu. This is the lowest level 2056 * raw protocol and you must do your own fragmentation at this level. 2057 */ 2058 2059 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2060 if (!netif_supports_nofcs(dev)) { 2061 err = -EPROTONOSUPPORT; 2062 goto out_unlock; 2063 } 2064 extra_len = 4; /* We're doing our own CRC */ 2065 } 2066 2067 err = -EMSGSIZE; 2068 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 2069 goto out_unlock; 2070 2071 if (!skb) { 2072 size_t reserved = LL_RESERVED_SPACE(dev); 2073 int tlen = dev->needed_tailroom; 2074 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 2075 2076 rcu_read_unlock(); 2077 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2078 if (skb == NULL) 2079 return -ENOBUFS; 2080 /* FIXME: Save some space for broken drivers that write a hard 2081 * header at transmission time by themselves. PPP is the notable 2082 * one here. This should really be fixed at the driver level. 2083 */ 2084 skb_reserve(skb, reserved); 2085 skb_reset_network_header(skb); 2086 2087 /* Try to align data part correctly */ 2088 if (hhlen) { 2089 skb->data -= hhlen; 2090 skb->tail -= hhlen; 2091 if (len < hhlen) 2092 skb_reset_network_header(skb); 2093 } 2094 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2095 if (err) 2096 goto out_free; 2097 goto retry; 2098 } 2099 2100 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2101 err = -EINVAL; 2102 goto out_unlock; 2103 } 2104 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 2105 !packet_extra_vlan_len_allowed(dev, skb)) { 2106 err = -EMSGSIZE; 2107 goto out_unlock; 2108 } 2109 2110 sockcm_init(&sockc, sk); 2111 if (msg->msg_controllen) { 2112 err = sock_cmsg_send(sk, msg, &sockc); 2113 if (unlikely(err)) 2114 goto out_unlock; 2115 } 2116 2117 skb->protocol = proto; 2118 skb->dev = dev; 2119 skb->priority = READ_ONCE(sk->sk_priority); 2120 skb->mark = READ_ONCE(sk->sk_mark); 2121 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2122 skb_setup_tx_timestamp(skb, &sockc); 2123 2124 if (unlikely(extra_len == 4)) 2125 skb->no_fcs = 1; 2126 2127 packet_parse_headers(skb, sock); 2128 2129 dev_queue_xmit(skb); 2130 rcu_read_unlock(); 2131 return len; 2132 2133 out_unlock: 2134 rcu_read_unlock(); 2135 out_free: 2136 kfree_skb(skb); 2137 return err; 2138 } 2139 2140 static unsigned int run_filter(struct sk_buff *skb, 2141 const struct sock *sk, 2142 unsigned int res) 2143 { 2144 struct sk_filter *filter; 2145 2146 rcu_read_lock(); 2147 filter = rcu_dereference(sk->sk_filter); 2148 if (filter != NULL) 2149 res = bpf_prog_run_clear_cb(filter->prog, skb); 2150 rcu_read_unlock(); 2151 2152 return res; 2153 } 2154 2155 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2156 size_t *len, int vnet_hdr_sz) 2157 { 2158 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2159 2160 if (*len < vnet_hdr_sz) 2161 return -EINVAL; 2162 *len -= vnet_hdr_sz; 2163 2164 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2165 return -EINVAL; 2166 2167 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2168 } 2169 2170 /* 2171 * This function makes lazy skb cloning in hope that most of packets 2172 * are discarded by BPF. 2173 * 2174 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2175 * and skb->cb are mangled. It works because (and until) packets 2176 * falling here are owned by current CPU. Output packets are cloned 2177 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2178 * sequentially, so that if we return skb to original state on exit, 2179 * we will not harm anyone. 2180 */ 2181 2182 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2183 struct packet_type *pt, struct net_device *orig_dev) 2184 { 2185 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2186 struct sock *sk = NULL; 2187 struct sockaddr_ll *sll; 2188 struct packet_sock *po; 2189 u8 *skb_head = skb->data; 2190 int skb_len = skb->len; 2191 unsigned int snaplen, res; 2192 2193 if (skb->pkt_type == PACKET_LOOPBACK) 2194 goto drop; 2195 2196 sk = pt->af_packet_priv; 2197 po = pkt_sk(sk); 2198 2199 if (!net_eq(dev_net(dev), sock_net(sk))) 2200 goto drop; 2201 2202 skb->dev = dev; 2203 2204 if (dev_has_header(dev)) { 2205 /* The device has an explicit notion of ll header, 2206 * exported to higher levels. 2207 * 2208 * Otherwise, the device hides details of its frame 2209 * structure, so that corresponding packet head is 2210 * never delivered to user. 2211 */ 2212 if (sk->sk_type != SOCK_DGRAM) 2213 skb_push(skb, skb->data - skb_mac_header(skb)); 2214 else if (skb->pkt_type == PACKET_OUTGOING) { 2215 /* Special case: outgoing packets have ll header at head */ 2216 skb_pull(skb, skb_network_offset(skb)); 2217 } 2218 } 2219 2220 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2221 2222 res = run_filter(skb, sk, snaplen); 2223 if (!res) 2224 goto drop_n_restore; 2225 if (snaplen > res) 2226 snaplen = res; 2227 2228 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2229 goto drop_n_acct; 2230 2231 if (skb_shared(skb)) { 2232 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2233 if (nskb == NULL) 2234 goto drop_n_acct; 2235 2236 if (skb_head != skb->data) { 2237 skb->data = skb_head; 2238 skb->len = skb_len; 2239 } 2240 consume_skb(skb); 2241 skb = nskb; 2242 } 2243 2244 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2245 2246 sll = &PACKET_SKB_CB(skb)->sa.ll; 2247 sll->sll_hatype = dev->type; 2248 sll->sll_pkttype = skb->pkt_type; 2249 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2250 sll->sll_ifindex = orig_dev->ifindex; 2251 else 2252 sll->sll_ifindex = dev->ifindex; 2253 2254 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2255 2256 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2257 * Use their space for storing the original skb length. 2258 */ 2259 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2260 2261 if (pskb_trim(skb, snaplen)) 2262 goto drop_n_acct; 2263 2264 skb_set_owner_r(skb, sk); 2265 skb->dev = NULL; 2266 skb_dst_drop(skb); 2267 2268 /* drop conntrack reference */ 2269 nf_reset_ct(skb); 2270 2271 spin_lock(&sk->sk_receive_queue.lock); 2272 po->stats.stats1.tp_packets++; 2273 sock_skb_set_dropcount(sk, skb); 2274 skb_clear_delivery_time(skb); 2275 __skb_queue_tail(&sk->sk_receive_queue, skb); 2276 spin_unlock(&sk->sk_receive_queue.lock); 2277 sk->sk_data_ready(sk); 2278 return 0; 2279 2280 drop_n_acct: 2281 atomic_inc(&po->tp_drops); 2282 atomic_inc(&sk->sk_drops); 2283 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2284 2285 drop_n_restore: 2286 if (skb_head != skb->data && skb_shared(skb)) { 2287 skb->data = skb_head; 2288 skb->len = skb_len; 2289 } 2290 drop: 2291 sk_skb_reason_drop(sk, skb, drop_reason); 2292 return 0; 2293 } 2294 2295 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2296 struct packet_type *pt, struct net_device *orig_dev) 2297 { 2298 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2299 struct sock *sk = NULL; 2300 struct packet_sock *po; 2301 struct sockaddr_ll *sll; 2302 union tpacket_uhdr h; 2303 u8 *skb_head = skb->data; 2304 int skb_len = skb->len; 2305 unsigned int snaplen, res; 2306 unsigned long status = TP_STATUS_USER; 2307 unsigned short macoff, hdrlen; 2308 unsigned int netoff; 2309 struct sk_buff *copy_skb = NULL; 2310 struct timespec64 ts; 2311 __u32 ts_status; 2312 unsigned int slot_id = 0; 2313 int vnet_hdr_sz = 0; 2314 2315 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2316 * We may add members to them until current aligned size without forcing 2317 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2318 */ 2319 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2320 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2321 2322 if (skb->pkt_type == PACKET_LOOPBACK) 2323 goto drop; 2324 2325 sk = pt->af_packet_priv; 2326 po = pkt_sk(sk); 2327 2328 if (!net_eq(dev_net(dev), sock_net(sk))) 2329 goto drop; 2330 2331 if (dev_has_header(dev)) { 2332 if (sk->sk_type != SOCK_DGRAM) 2333 skb_push(skb, skb->data - skb_mac_header(skb)); 2334 else if (skb->pkt_type == PACKET_OUTGOING) { 2335 /* Special case: outgoing packets have ll header at head */ 2336 skb_pull(skb, skb_network_offset(skb)); 2337 } 2338 } 2339 2340 snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); 2341 2342 res = run_filter(skb, sk, snaplen); 2343 if (!res) 2344 goto drop_n_restore; 2345 2346 /* If we are flooded, just give up */ 2347 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2348 atomic_inc(&po->tp_drops); 2349 goto drop_n_restore; 2350 } 2351 2352 if (skb->ip_summed == CHECKSUM_PARTIAL) 2353 status |= TP_STATUS_CSUMNOTREADY; 2354 else if (skb->pkt_type != PACKET_OUTGOING && 2355 skb_csum_unnecessary(skb)) 2356 status |= TP_STATUS_CSUM_VALID; 2357 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2358 status |= TP_STATUS_GSO_TCP; 2359 2360 if (snaplen > res) 2361 snaplen = res; 2362 2363 if (sk->sk_type == SOCK_DGRAM) { 2364 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2365 po->tp_reserve; 2366 } else { 2367 unsigned int maclen = skb_network_offset(skb); 2368 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2369 (maclen < 16 ? 16 : maclen)) + 2370 po->tp_reserve; 2371 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2372 if (vnet_hdr_sz) 2373 netoff += vnet_hdr_sz; 2374 macoff = netoff - maclen; 2375 } 2376 if (netoff > USHRT_MAX) { 2377 atomic_inc(&po->tp_drops); 2378 goto drop_n_restore; 2379 } 2380 if (po->tp_version <= TPACKET_V2) { 2381 if (macoff + snaplen > po->rx_ring.frame_size) { 2382 if (READ_ONCE(po->copy_thresh) && 2383 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2384 if (skb_shared(skb)) { 2385 copy_skb = skb_clone(skb, GFP_ATOMIC); 2386 } else { 2387 copy_skb = skb_get(skb); 2388 skb_head = skb->data; 2389 } 2390 if (copy_skb) { 2391 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2392 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2393 skb_set_owner_r(copy_skb, sk); 2394 } 2395 } 2396 snaplen = po->rx_ring.frame_size - macoff; 2397 if ((int)snaplen < 0) { 2398 snaplen = 0; 2399 vnet_hdr_sz = 0; 2400 } 2401 } 2402 } else if (unlikely(macoff + snaplen > 2403 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2404 u32 nval; 2405 2406 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2407 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2408 snaplen, nval, macoff); 2409 snaplen = nval; 2410 if (unlikely((int)snaplen < 0)) { 2411 snaplen = 0; 2412 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2413 vnet_hdr_sz = 0; 2414 } 2415 } 2416 spin_lock(&sk->sk_receive_queue.lock); 2417 h.raw = packet_current_rx_frame(po, skb, 2418 TP_STATUS_KERNEL, (macoff+snaplen)); 2419 if (!h.raw) 2420 goto drop_n_account; 2421 2422 if (po->tp_version <= TPACKET_V2) { 2423 slot_id = po->rx_ring.head; 2424 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2425 goto drop_n_account; 2426 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2427 } 2428 2429 if (vnet_hdr_sz && 2430 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2431 sizeof(struct virtio_net_hdr), 2432 vio_le(), true, 0)) { 2433 if (po->tp_version == TPACKET_V3) 2434 prb_clear_blk_fill_status(&po->rx_ring); 2435 goto drop_n_account; 2436 } 2437 2438 if (po->tp_version <= TPACKET_V2) { 2439 packet_increment_rx_head(po, &po->rx_ring); 2440 /* 2441 * LOSING will be reported till you read the stats, 2442 * because it's COR - Clear On Read. 2443 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2444 * at packet level. 2445 */ 2446 if (atomic_read(&po->tp_drops)) 2447 status |= TP_STATUS_LOSING; 2448 } 2449 2450 po->stats.stats1.tp_packets++; 2451 if (copy_skb) { 2452 status |= TP_STATUS_COPY; 2453 skb_clear_delivery_time(copy_skb); 2454 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2455 } 2456 spin_unlock(&sk->sk_receive_queue.lock); 2457 2458 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2459 2460 /* Always timestamp; prefer an existing software timestamp taken 2461 * closer to the time of capture. 2462 */ 2463 ts_status = tpacket_get_timestamp(skb, &ts, 2464 READ_ONCE(po->tp_tstamp) | 2465 SOF_TIMESTAMPING_SOFTWARE); 2466 if (!ts_status) 2467 ktime_get_real_ts64(&ts); 2468 2469 status |= ts_status; 2470 2471 switch (po->tp_version) { 2472 case TPACKET_V1: 2473 h.h1->tp_len = skb->len; 2474 h.h1->tp_snaplen = snaplen; 2475 h.h1->tp_mac = macoff; 2476 h.h1->tp_net = netoff; 2477 h.h1->tp_sec = ts.tv_sec; 2478 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2479 hdrlen = sizeof(*h.h1); 2480 break; 2481 case TPACKET_V2: 2482 h.h2->tp_len = skb->len; 2483 h.h2->tp_snaplen = snaplen; 2484 h.h2->tp_mac = macoff; 2485 h.h2->tp_net = netoff; 2486 h.h2->tp_sec = ts.tv_sec; 2487 h.h2->tp_nsec = ts.tv_nsec; 2488 if (skb_vlan_tag_present(skb)) { 2489 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2490 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2491 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2492 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2493 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2494 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2495 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2496 } else { 2497 h.h2->tp_vlan_tci = 0; 2498 h.h2->tp_vlan_tpid = 0; 2499 } 2500 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2501 hdrlen = sizeof(*h.h2); 2502 break; 2503 case TPACKET_V3: 2504 /* tp_nxt_offset,vlan are already populated above. 2505 * So DONT clear those fields here 2506 */ 2507 h.h3->tp_status |= status; 2508 h.h3->tp_len = skb->len; 2509 h.h3->tp_snaplen = snaplen; 2510 h.h3->tp_mac = macoff; 2511 h.h3->tp_net = netoff; 2512 h.h3->tp_sec = ts.tv_sec; 2513 h.h3->tp_nsec = ts.tv_nsec; 2514 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2515 hdrlen = sizeof(*h.h3); 2516 break; 2517 default: 2518 BUG(); 2519 } 2520 2521 sll = h.raw + TPACKET_ALIGN(hdrlen); 2522 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2523 sll->sll_family = AF_PACKET; 2524 sll->sll_hatype = dev->type; 2525 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2526 vlan_get_protocol_dgram(skb) : skb->protocol; 2527 sll->sll_pkttype = skb->pkt_type; 2528 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2529 sll->sll_ifindex = orig_dev->ifindex; 2530 else 2531 sll->sll_ifindex = dev->ifindex; 2532 2533 smp_mb(); 2534 2535 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2536 if (po->tp_version <= TPACKET_V2) { 2537 u8 *start, *end; 2538 2539 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2540 macoff + snaplen); 2541 2542 for (start = h.raw; start < end; start += PAGE_SIZE) 2543 flush_dcache_page(pgv_to_page(start)); 2544 } 2545 smp_wmb(); 2546 #endif 2547 2548 if (po->tp_version <= TPACKET_V2) { 2549 spin_lock(&sk->sk_receive_queue.lock); 2550 __packet_set_status(po, h.raw, status); 2551 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2552 spin_unlock(&sk->sk_receive_queue.lock); 2553 sk->sk_data_ready(sk); 2554 } else if (po->tp_version == TPACKET_V3) { 2555 prb_clear_blk_fill_status(&po->rx_ring); 2556 } 2557 2558 drop_n_restore: 2559 if (skb_head != skb->data && skb_shared(skb)) { 2560 skb->data = skb_head; 2561 skb->len = skb_len; 2562 } 2563 drop: 2564 sk_skb_reason_drop(sk, skb, drop_reason); 2565 return 0; 2566 2567 drop_n_account: 2568 spin_unlock(&sk->sk_receive_queue.lock); 2569 atomic_inc(&po->tp_drops); 2570 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2571 2572 sk->sk_data_ready(sk); 2573 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2574 goto drop_n_restore; 2575 } 2576 2577 static void tpacket_destruct_skb(struct sk_buff *skb) 2578 { 2579 struct packet_sock *po = pkt_sk(skb->sk); 2580 2581 if (likely(po->tx_ring.pg_vec)) { 2582 void *ph; 2583 __u32 ts; 2584 2585 ph = skb_zcopy_get_nouarg(skb); 2586 packet_dec_pending(&po->tx_ring); 2587 2588 ts = __packet_set_timestamp(po, ph, skb); 2589 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2590 2591 complete(&po->skb_completion); 2592 } 2593 2594 sock_wfree(skb); 2595 } 2596 2597 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2598 { 2599 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2600 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2601 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2602 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2603 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2604 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2605 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2606 2607 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2608 return -EINVAL; 2609 2610 return 0; 2611 } 2612 2613 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2614 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2615 { 2616 int ret; 2617 2618 if (*len < vnet_hdr_sz) 2619 return -EINVAL; 2620 *len -= vnet_hdr_sz; 2621 2622 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2623 return -EFAULT; 2624 2625 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2626 if (ret) 2627 return ret; 2628 2629 /* move iter to point to the start of mac header */ 2630 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2631 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2632 2633 return 0; 2634 } 2635 2636 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2637 void *frame, struct net_device *dev, void *data, int tp_len, 2638 __be16 proto, unsigned char *addr, int hlen, int copylen, 2639 const struct sockcm_cookie *sockc) 2640 { 2641 union tpacket_uhdr ph; 2642 int to_write, offset, len, nr_frags, len_max; 2643 struct socket *sock = po->sk.sk_socket; 2644 struct page *page; 2645 int err; 2646 2647 ph.raw = frame; 2648 2649 skb->protocol = proto; 2650 skb->dev = dev; 2651 skb->priority = READ_ONCE(po->sk.sk_priority); 2652 skb->mark = READ_ONCE(po->sk.sk_mark); 2653 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2654 skb_setup_tx_timestamp(skb, sockc); 2655 skb_zcopy_set_nouarg(skb, ph.raw); 2656 2657 skb_reserve(skb, hlen); 2658 skb_reset_network_header(skb); 2659 2660 to_write = tp_len; 2661 2662 if (sock->type == SOCK_DGRAM) { 2663 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2664 NULL, tp_len); 2665 if (unlikely(err < 0)) 2666 return -EINVAL; 2667 } else if (copylen) { 2668 int hdrlen = min_t(int, copylen, tp_len); 2669 2670 skb_push(skb, dev->hard_header_len); 2671 skb_put(skb, copylen - dev->hard_header_len); 2672 err = skb_store_bits(skb, 0, data, hdrlen); 2673 if (unlikely(err)) 2674 return err; 2675 if (!dev_validate_header(dev, skb->data, hdrlen)) 2676 return -EINVAL; 2677 2678 data += hdrlen; 2679 to_write -= hdrlen; 2680 } 2681 2682 offset = offset_in_page(data); 2683 len_max = PAGE_SIZE - offset; 2684 len = ((to_write > len_max) ? len_max : to_write); 2685 2686 skb->data_len = to_write; 2687 skb->len += to_write; 2688 skb->truesize += to_write; 2689 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2690 2691 while (likely(to_write)) { 2692 nr_frags = skb_shinfo(skb)->nr_frags; 2693 2694 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2695 pr_err("Packet exceed the number of skb frags(%u)\n", 2696 (unsigned int)MAX_SKB_FRAGS); 2697 return -EFAULT; 2698 } 2699 2700 page = pgv_to_page(data); 2701 data += len; 2702 flush_dcache_page(page); 2703 get_page(page); 2704 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2705 to_write -= len; 2706 offset = 0; 2707 len_max = PAGE_SIZE; 2708 len = ((to_write > len_max) ? len_max : to_write); 2709 } 2710 2711 packet_parse_headers(skb, sock); 2712 2713 return tp_len; 2714 } 2715 2716 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2717 int size_max, void **data) 2718 { 2719 union tpacket_uhdr ph; 2720 int tp_len, off; 2721 2722 ph.raw = frame; 2723 2724 switch (po->tp_version) { 2725 case TPACKET_V3: 2726 if (ph.h3->tp_next_offset != 0) { 2727 pr_warn_once("variable sized slot not supported"); 2728 return -EINVAL; 2729 } 2730 tp_len = ph.h3->tp_len; 2731 break; 2732 case TPACKET_V2: 2733 tp_len = ph.h2->tp_len; 2734 break; 2735 default: 2736 tp_len = ph.h1->tp_len; 2737 break; 2738 } 2739 if (unlikely(tp_len > size_max)) { 2740 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2741 return -EMSGSIZE; 2742 } 2743 2744 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2745 int off_min, off_max; 2746 2747 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2748 off_max = po->tx_ring.frame_size - tp_len; 2749 if (po->sk.sk_type == SOCK_DGRAM) { 2750 switch (po->tp_version) { 2751 case TPACKET_V3: 2752 off = ph.h3->tp_net; 2753 break; 2754 case TPACKET_V2: 2755 off = ph.h2->tp_net; 2756 break; 2757 default: 2758 off = ph.h1->tp_net; 2759 break; 2760 } 2761 } else { 2762 switch (po->tp_version) { 2763 case TPACKET_V3: 2764 off = ph.h3->tp_mac; 2765 break; 2766 case TPACKET_V2: 2767 off = ph.h2->tp_mac; 2768 break; 2769 default: 2770 off = ph.h1->tp_mac; 2771 break; 2772 } 2773 } 2774 if (unlikely((off < off_min) || (off_max < off))) 2775 return -EINVAL; 2776 } else { 2777 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2778 } 2779 2780 *data = frame + off; 2781 return tp_len; 2782 } 2783 2784 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2785 { 2786 struct sk_buff *skb = NULL; 2787 struct net_device *dev; 2788 struct virtio_net_hdr *vnet_hdr = NULL; 2789 struct sockcm_cookie sockc; 2790 __be16 proto; 2791 int err, reserve = 0; 2792 void *ph; 2793 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2794 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2795 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2796 unsigned char *addr = NULL; 2797 int tp_len, size_max; 2798 void *data; 2799 int len_sum = 0; 2800 int status = TP_STATUS_AVAILABLE; 2801 int hlen, tlen, copylen = 0; 2802 long timeo = 0; 2803 2804 mutex_lock(&po->pg_vec_lock); 2805 2806 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2807 * we need to confirm it under protection of pg_vec_lock. 2808 */ 2809 if (unlikely(!po->tx_ring.pg_vec)) { 2810 err = -EBUSY; 2811 goto out; 2812 } 2813 if (likely(saddr == NULL)) { 2814 dev = packet_cached_dev_get(po); 2815 proto = READ_ONCE(po->num); 2816 } else { 2817 err = -EINVAL; 2818 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2819 goto out; 2820 if (msg->msg_namelen < (saddr->sll_halen 2821 + offsetof(struct sockaddr_ll, 2822 sll_addr))) 2823 goto out; 2824 proto = saddr->sll_protocol; 2825 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2826 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2827 if (dev && msg->msg_namelen < dev->addr_len + 2828 offsetof(struct sockaddr_ll, sll_addr)) 2829 goto out_put; 2830 addr = saddr->sll_addr; 2831 } 2832 } 2833 2834 err = -ENXIO; 2835 if (unlikely(dev == NULL)) 2836 goto out; 2837 err = -ENETDOWN; 2838 if (unlikely(!(dev->flags & IFF_UP))) 2839 goto out_put; 2840 2841 sockcm_init(&sockc, &po->sk); 2842 if (msg->msg_controllen) { 2843 err = sock_cmsg_send(&po->sk, msg, &sockc); 2844 if (unlikely(err)) 2845 goto out_put; 2846 } 2847 2848 if (po->sk.sk_socket->type == SOCK_RAW) 2849 reserve = dev->hard_header_len; 2850 size_max = po->tx_ring.frame_size 2851 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2852 2853 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2854 size_max = dev->mtu + reserve + VLAN_HLEN; 2855 2856 reinit_completion(&po->skb_completion); 2857 2858 do { 2859 ph = packet_current_frame(po, &po->tx_ring, 2860 TP_STATUS_SEND_REQUEST); 2861 if (unlikely(ph == NULL)) { 2862 if (need_wait && skb) { 2863 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2864 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2865 if (timeo <= 0) { 2866 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2867 goto out_put; 2868 } 2869 } 2870 /* check for additional frames */ 2871 continue; 2872 } 2873 2874 skb = NULL; 2875 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2876 if (tp_len < 0) 2877 goto tpacket_error; 2878 2879 status = TP_STATUS_SEND_REQUEST; 2880 hlen = LL_RESERVED_SPACE(dev); 2881 tlen = dev->needed_tailroom; 2882 if (vnet_hdr_sz) { 2883 vnet_hdr = data; 2884 data += vnet_hdr_sz; 2885 tp_len -= vnet_hdr_sz; 2886 if (tp_len < 0 || 2887 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2888 tp_len = -EINVAL; 2889 goto tpacket_error; 2890 } 2891 copylen = __virtio16_to_cpu(vio_le(), 2892 vnet_hdr->hdr_len); 2893 } 2894 copylen = max_t(int, copylen, dev->hard_header_len); 2895 skb = sock_alloc_send_skb(&po->sk, 2896 hlen + tlen + sizeof(struct sockaddr_ll) + 2897 (copylen - dev->hard_header_len), 2898 !need_wait, &err); 2899 2900 if (unlikely(skb == NULL)) { 2901 /* we assume the socket was initially writeable ... */ 2902 if (likely(len_sum > 0)) 2903 err = len_sum; 2904 goto out_status; 2905 } 2906 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2907 addr, hlen, copylen, &sockc); 2908 if (likely(tp_len >= 0) && 2909 tp_len > dev->mtu + reserve && 2910 !vnet_hdr_sz && 2911 !packet_extra_vlan_len_allowed(dev, skb)) 2912 tp_len = -EMSGSIZE; 2913 2914 if (unlikely(tp_len < 0)) { 2915 tpacket_error: 2916 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2917 __packet_set_status(po, ph, 2918 TP_STATUS_AVAILABLE); 2919 packet_increment_head(&po->tx_ring); 2920 kfree_skb(skb); 2921 continue; 2922 } else { 2923 status = TP_STATUS_WRONG_FORMAT; 2924 err = tp_len; 2925 goto out_status; 2926 } 2927 } 2928 2929 if (vnet_hdr_sz) { 2930 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { 2931 tp_len = -EINVAL; 2932 goto tpacket_error; 2933 } 2934 virtio_net_hdr_set_proto(skb, vnet_hdr); 2935 } 2936 2937 skb->destructor = tpacket_destruct_skb; 2938 __packet_set_status(po, ph, TP_STATUS_SENDING); 2939 packet_inc_pending(&po->tx_ring); 2940 2941 status = TP_STATUS_SEND_REQUEST; 2942 err = packet_xmit(po, skb); 2943 if (unlikely(err != 0)) { 2944 if (err > 0) 2945 err = net_xmit_errno(err); 2946 if (err && __packet_get_status(po, ph) == 2947 TP_STATUS_AVAILABLE) { 2948 /* skb was destructed already */ 2949 skb = NULL; 2950 goto out_status; 2951 } 2952 /* 2953 * skb was dropped but not destructed yet; 2954 * let's treat it like congestion or err < 0 2955 */ 2956 err = 0; 2957 } 2958 packet_increment_head(&po->tx_ring); 2959 len_sum += tp_len; 2960 } while (likely((ph != NULL) || 2961 /* Note: packet_read_pending() might be slow if we have 2962 * to call it as it's per_cpu variable, but in fast-path 2963 * we already short-circuit the loop with the first 2964 * condition, and luckily don't have to go that path 2965 * anyway. 2966 */ 2967 (need_wait && packet_read_pending(&po->tx_ring)))); 2968 2969 err = len_sum; 2970 goto out_put; 2971 2972 out_status: 2973 __packet_set_status(po, ph, status); 2974 kfree_skb(skb); 2975 out_put: 2976 dev_put(dev); 2977 out: 2978 mutex_unlock(&po->pg_vec_lock); 2979 return err; 2980 } 2981 2982 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2983 size_t reserve, size_t len, 2984 size_t linear, int noblock, 2985 int *err) 2986 { 2987 struct sk_buff *skb; 2988 2989 /* Under a page? Don't bother with paged skb. */ 2990 if (prepad + len < PAGE_SIZE || !linear) 2991 linear = len; 2992 2993 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2994 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2995 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2996 err, PAGE_ALLOC_COSTLY_ORDER); 2997 if (!skb) 2998 return NULL; 2999 3000 skb_reserve(skb, reserve); 3001 skb_put(skb, linear); 3002 skb->data_len = len - linear; 3003 skb->len += len - linear; 3004 3005 return skb; 3006 } 3007 3008 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 3009 { 3010 struct sock *sk = sock->sk; 3011 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 3012 struct sk_buff *skb; 3013 struct net_device *dev; 3014 __be16 proto; 3015 unsigned char *addr = NULL; 3016 int err, reserve = 0; 3017 struct sockcm_cookie sockc; 3018 struct virtio_net_hdr vnet_hdr = { 0 }; 3019 int offset = 0; 3020 struct packet_sock *po = pkt_sk(sk); 3021 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 3022 int hlen, tlen, linear; 3023 int extra_len = 0; 3024 3025 /* 3026 * Get and verify the address. 3027 */ 3028 3029 if (likely(saddr == NULL)) { 3030 dev = packet_cached_dev_get(po); 3031 proto = READ_ONCE(po->num); 3032 } else { 3033 err = -EINVAL; 3034 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 3035 goto out; 3036 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 3037 goto out; 3038 proto = saddr->sll_protocol; 3039 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 3040 if (sock->type == SOCK_DGRAM) { 3041 if (dev && msg->msg_namelen < dev->addr_len + 3042 offsetof(struct sockaddr_ll, sll_addr)) 3043 goto out_unlock; 3044 addr = saddr->sll_addr; 3045 } 3046 } 3047 3048 err = -ENXIO; 3049 if (unlikely(dev == NULL)) 3050 goto out_unlock; 3051 err = -ENETDOWN; 3052 if (unlikely(!(dev->flags & IFF_UP))) 3053 goto out_unlock; 3054 3055 sockcm_init(&sockc, sk); 3056 sockc.mark = READ_ONCE(sk->sk_mark); 3057 if (msg->msg_controllen) { 3058 err = sock_cmsg_send(sk, msg, &sockc); 3059 if (unlikely(err)) 3060 goto out_unlock; 3061 } 3062 3063 if (sock->type == SOCK_RAW) 3064 reserve = dev->hard_header_len; 3065 if (vnet_hdr_sz) { 3066 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3067 if (err) 3068 goto out_unlock; 3069 } 3070 3071 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3072 if (!netif_supports_nofcs(dev)) { 3073 err = -EPROTONOSUPPORT; 3074 goto out_unlock; 3075 } 3076 extra_len = 4; /* We're doing our own CRC */ 3077 } 3078 3079 err = -EMSGSIZE; 3080 if (!vnet_hdr.gso_type && 3081 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3082 goto out_unlock; 3083 3084 err = -ENOBUFS; 3085 hlen = LL_RESERVED_SPACE(dev); 3086 tlen = dev->needed_tailroom; 3087 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3088 linear = max(linear, min_t(int, len, dev->hard_header_len)); 3089 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3090 msg->msg_flags & MSG_DONTWAIT, &err); 3091 if (skb == NULL) 3092 goto out_unlock; 3093 3094 skb_reset_network_header(skb); 3095 3096 err = -EINVAL; 3097 if (sock->type == SOCK_DGRAM) { 3098 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3099 if (unlikely(offset < 0)) 3100 goto out_free; 3101 } else if (reserve) { 3102 skb_reserve(skb, -reserve); 3103 if (len < reserve + sizeof(struct ipv6hdr) && 3104 dev->min_header_len != dev->hard_header_len) 3105 skb_reset_network_header(skb); 3106 } 3107 3108 /* Returns -EFAULT on error */ 3109 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3110 if (err) 3111 goto out_free; 3112 3113 if ((sock->type == SOCK_RAW && 3114 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3115 err = -EINVAL; 3116 goto out_free; 3117 } 3118 3119 skb_setup_tx_timestamp(skb, &sockc); 3120 3121 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3122 !packet_extra_vlan_len_allowed(dev, skb)) { 3123 err = -EMSGSIZE; 3124 goto out_free; 3125 } 3126 3127 skb->protocol = proto; 3128 skb->dev = dev; 3129 skb->priority = READ_ONCE(sk->sk_priority); 3130 skb->mark = sockc.mark; 3131 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3132 3133 if (unlikely(extra_len == 4)) 3134 skb->no_fcs = 1; 3135 3136 packet_parse_headers(skb, sock); 3137 3138 if (vnet_hdr_sz) { 3139 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3140 if (err) 3141 goto out_free; 3142 len += vnet_hdr_sz; 3143 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3144 } 3145 3146 err = packet_xmit(po, skb); 3147 3148 if (unlikely(err != 0)) { 3149 if (err > 0) 3150 err = net_xmit_errno(err); 3151 if (err) 3152 goto out_unlock; 3153 } 3154 3155 dev_put(dev); 3156 3157 return len; 3158 3159 out_free: 3160 kfree_skb(skb); 3161 out_unlock: 3162 dev_put(dev); 3163 out: 3164 return err; 3165 } 3166 3167 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3168 { 3169 struct sock *sk = sock->sk; 3170 struct packet_sock *po = pkt_sk(sk); 3171 3172 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3173 * tpacket_snd() will redo the check safely. 3174 */ 3175 if (data_race(po->tx_ring.pg_vec)) 3176 return tpacket_snd(po, msg); 3177 3178 return packet_snd(sock, msg, len); 3179 } 3180 3181 /* 3182 * Close a PACKET socket. This is fairly simple. We immediately go 3183 * to 'closed' state and remove our protocol entry in the device list. 3184 */ 3185 3186 static int packet_release(struct socket *sock) 3187 { 3188 struct sock *sk = sock->sk; 3189 struct packet_sock *po; 3190 struct packet_fanout *f; 3191 struct net *net; 3192 union tpacket_req_u req_u; 3193 3194 if (!sk) 3195 return 0; 3196 3197 net = sock_net(sk); 3198 po = pkt_sk(sk); 3199 3200 mutex_lock(&net->packet.sklist_lock); 3201 sk_del_node_init_rcu(sk); 3202 mutex_unlock(&net->packet.sklist_lock); 3203 3204 sock_prot_inuse_add(net, sk->sk_prot, -1); 3205 3206 spin_lock(&po->bind_lock); 3207 unregister_prot_hook(sk, false); 3208 packet_cached_dev_reset(po); 3209 3210 if (po->prot_hook.dev) { 3211 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3212 po->prot_hook.dev = NULL; 3213 } 3214 spin_unlock(&po->bind_lock); 3215 3216 packet_flush_mclist(sk); 3217 3218 lock_sock(sk); 3219 if (po->rx_ring.pg_vec) { 3220 memset(&req_u, 0, sizeof(req_u)); 3221 packet_set_ring(sk, &req_u, 1, 0); 3222 } 3223 3224 if (po->tx_ring.pg_vec) { 3225 memset(&req_u, 0, sizeof(req_u)); 3226 packet_set_ring(sk, &req_u, 1, 1); 3227 } 3228 release_sock(sk); 3229 3230 f = fanout_release(sk); 3231 3232 synchronize_net(); 3233 3234 kfree(po->rollover); 3235 if (f) { 3236 fanout_release_data(f); 3237 kvfree(f); 3238 } 3239 /* 3240 * Now the socket is dead. No more input will appear. 3241 */ 3242 sock_orphan(sk); 3243 sock->sk = NULL; 3244 3245 /* Purge queues */ 3246 3247 skb_queue_purge(&sk->sk_receive_queue); 3248 packet_free_pending(po); 3249 3250 sock_put(sk); 3251 return 0; 3252 } 3253 3254 /* 3255 * Attach a packet hook. 3256 */ 3257 3258 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3259 __be16 proto) 3260 { 3261 struct packet_sock *po = pkt_sk(sk); 3262 struct net_device *dev = NULL; 3263 bool unlisted = false; 3264 bool need_rehook; 3265 int ret = 0; 3266 3267 lock_sock(sk); 3268 spin_lock(&po->bind_lock); 3269 if (!proto) 3270 proto = po->num; 3271 3272 rcu_read_lock(); 3273 3274 if (po->fanout) { 3275 ret = -EINVAL; 3276 goto out_unlock; 3277 } 3278 3279 if (name) { 3280 dev = dev_get_by_name_rcu(sock_net(sk), name); 3281 if (!dev) { 3282 ret = -ENODEV; 3283 goto out_unlock; 3284 } 3285 } else if (ifindex) { 3286 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3287 if (!dev) { 3288 ret = -ENODEV; 3289 goto out_unlock; 3290 } 3291 } 3292 3293 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3294 3295 if (need_rehook) { 3296 dev_hold(dev); 3297 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3298 rcu_read_unlock(); 3299 /* prevents packet_notifier() from calling 3300 * register_prot_hook() 3301 */ 3302 WRITE_ONCE(po->num, 0); 3303 __unregister_prot_hook(sk, true); 3304 rcu_read_lock(); 3305 if (dev) 3306 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3307 dev->ifindex); 3308 } 3309 3310 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3311 WRITE_ONCE(po->num, proto); 3312 po->prot_hook.type = proto; 3313 3314 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3315 3316 if (unlikely(unlisted)) { 3317 po->prot_hook.dev = NULL; 3318 WRITE_ONCE(po->ifindex, -1); 3319 packet_cached_dev_reset(po); 3320 } else { 3321 netdev_hold(dev, &po->prot_hook.dev_tracker, 3322 GFP_ATOMIC); 3323 po->prot_hook.dev = dev; 3324 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3325 packet_cached_dev_assign(po, dev); 3326 } 3327 dev_put(dev); 3328 } 3329 3330 if (proto == 0 || !need_rehook) 3331 goto out_unlock; 3332 3333 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3334 register_prot_hook(sk); 3335 } else { 3336 sk->sk_err = ENETDOWN; 3337 if (!sock_flag(sk, SOCK_DEAD)) 3338 sk_error_report(sk); 3339 } 3340 3341 out_unlock: 3342 rcu_read_unlock(); 3343 spin_unlock(&po->bind_lock); 3344 release_sock(sk); 3345 return ret; 3346 } 3347 3348 /* 3349 * Bind a packet socket to a device 3350 */ 3351 3352 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3353 int addr_len) 3354 { 3355 struct sock *sk = sock->sk; 3356 char name[sizeof(uaddr->sa_data_min) + 1]; 3357 3358 /* 3359 * Check legality 3360 */ 3361 3362 if (addr_len != sizeof(struct sockaddr)) 3363 return -EINVAL; 3364 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3365 * zero-terminated. 3366 */ 3367 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min)); 3368 name[sizeof(uaddr->sa_data_min)] = 0; 3369 3370 return packet_do_bind(sk, name, 0, 0); 3371 } 3372 3373 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3374 { 3375 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3376 struct sock *sk = sock->sk; 3377 3378 /* 3379 * Check legality 3380 */ 3381 3382 if (addr_len < sizeof(struct sockaddr_ll)) 3383 return -EINVAL; 3384 if (sll->sll_family != AF_PACKET) 3385 return -EINVAL; 3386 3387 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3388 } 3389 3390 static struct proto packet_proto = { 3391 .name = "PACKET", 3392 .owner = THIS_MODULE, 3393 .obj_size = sizeof(struct packet_sock), 3394 }; 3395 3396 /* 3397 * Create a packet of type SOCK_PACKET. 3398 */ 3399 3400 static int packet_create(struct net *net, struct socket *sock, int protocol, 3401 int kern) 3402 { 3403 struct sock *sk; 3404 struct packet_sock *po; 3405 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3406 int err; 3407 3408 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3409 return -EPERM; 3410 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3411 sock->type != SOCK_PACKET) 3412 return -ESOCKTNOSUPPORT; 3413 3414 sock->state = SS_UNCONNECTED; 3415 3416 err = -ENOBUFS; 3417 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3418 if (sk == NULL) 3419 goto out; 3420 3421 sock->ops = &packet_ops; 3422 if (sock->type == SOCK_PACKET) 3423 sock->ops = &packet_ops_spkt; 3424 3425 po = pkt_sk(sk); 3426 err = packet_alloc_pending(po); 3427 if (err) 3428 goto out_sk_free; 3429 3430 sock_init_data(sock, sk); 3431 3432 init_completion(&po->skb_completion); 3433 sk->sk_family = PF_PACKET; 3434 po->num = proto; 3435 3436 packet_cached_dev_reset(po); 3437 3438 sk->sk_destruct = packet_sock_destruct; 3439 3440 /* 3441 * Attach a protocol block 3442 */ 3443 3444 spin_lock_init(&po->bind_lock); 3445 mutex_init(&po->pg_vec_lock); 3446 po->rollover = NULL; 3447 po->prot_hook.func = packet_rcv; 3448 3449 if (sock->type == SOCK_PACKET) 3450 po->prot_hook.func = packet_rcv_spkt; 3451 3452 po->prot_hook.af_packet_priv = sk; 3453 po->prot_hook.af_packet_net = sock_net(sk); 3454 3455 if (proto) { 3456 po->prot_hook.type = proto; 3457 __register_prot_hook(sk); 3458 } 3459 3460 mutex_lock(&net->packet.sklist_lock); 3461 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3462 mutex_unlock(&net->packet.sklist_lock); 3463 3464 sock_prot_inuse_add(net, &packet_proto, 1); 3465 3466 return 0; 3467 out_sk_free: 3468 sk_free(sk); 3469 out: 3470 return err; 3471 } 3472 3473 /* 3474 * Pull a packet from our receive queue and hand it to the user. 3475 * If necessary we block. 3476 */ 3477 3478 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3479 int flags) 3480 { 3481 struct sock *sk = sock->sk; 3482 struct sk_buff *skb; 3483 int copied, err; 3484 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3485 unsigned int origlen = 0; 3486 3487 err = -EINVAL; 3488 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3489 goto out; 3490 3491 #if 0 3492 /* What error should we return now? EUNATTACH? */ 3493 if (pkt_sk(sk)->ifindex < 0) 3494 return -ENODEV; 3495 #endif 3496 3497 if (flags & MSG_ERRQUEUE) { 3498 err = sock_recv_errqueue(sk, msg, len, 3499 SOL_PACKET, PACKET_TX_TIMESTAMP); 3500 goto out; 3501 } 3502 3503 /* 3504 * Call the generic datagram receiver. This handles all sorts 3505 * of horrible races and re-entrancy so we can forget about it 3506 * in the protocol layers. 3507 * 3508 * Now it will return ENETDOWN, if device have just gone down, 3509 * but then it will block. 3510 */ 3511 3512 skb = skb_recv_datagram(sk, flags, &err); 3513 3514 /* 3515 * An error occurred so return it. Because skb_recv_datagram() 3516 * handles the blocking we don't see and worry about blocking 3517 * retries. 3518 */ 3519 3520 if (skb == NULL) 3521 goto out; 3522 3523 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3524 3525 if (vnet_hdr_len) { 3526 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3527 if (err) 3528 goto out_free; 3529 } 3530 3531 /* You lose any data beyond the buffer you gave. If it worries 3532 * a user program they can ask the device for its MTU 3533 * anyway. 3534 */ 3535 copied = skb->len; 3536 if (copied > len) { 3537 copied = len; 3538 msg->msg_flags |= MSG_TRUNC; 3539 } 3540 3541 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3542 if (err) 3543 goto out_free; 3544 3545 if (sock->type != SOCK_PACKET) { 3546 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3547 3548 /* Original length was stored in sockaddr_ll fields */ 3549 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3550 sll->sll_family = AF_PACKET; 3551 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3552 vlan_get_protocol_dgram(skb) : skb->protocol; 3553 } 3554 3555 sock_recv_cmsgs(msg, sk, skb); 3556 3557 if (msg->msg_name) { 3558 const size_t max_len = min(sizeof(skb->cb), 3559 sizeof(struct sockaddr_storage)); 3560 int copy_len; 3561 3562 /* If the address length field is there to be filled 3563 * in, we fill it in now. 3564 */ 3565 if (sock->type == SOCK_PACKET) { 3566 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3567 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3568 copy_len = msg->msg_namelen; 3569 } else { 3570 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3571 3572 msg->msg_namelen = sll->sll_halen + 3573 offsetof(struct sockaddr_ll, sll_addr); 3574 copy_len = msg->msg_namelen; 3575 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3576 memset(msg->msg_name + 3577 offsetof(struct sockaddr_ll, sll_addr), 3578 0, sizeof(sll->sll_addr)); 3579 msg->msg_namelen = sizeof(struct sockaddr_ll); 3580 } 3581 } 3582 if (WARN_ON_ONCE(copy_len > max_len)) { 3583 copy_len = max_len; 3584 msg->msg_namelen = copy_len; 3585 } 3586 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3587 } 3588 3589 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3590 struct tpacket_auxdata aux; 3591 3592 aux.tp_status = TP_STATUS_USER; 3593 if (skb->ip_summed == CHECKSUM_PARTIAL) 3594 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3595 else if (skb->pkt_type != PACKET_OUTGOING && 3596 skb_csum_unnecessary(skb)) 3597 aux.tp_status |= TP_STATUS_CSUM_VALID; 3598 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3599 aux.tp_status |= TP_STATUS_GSO_TCP; 3600 3601 aux.tp_len = origlen; 3602 aux.tp_snaplen = skb->len; 3603 aux.tp_mac = 0; 3604 aux.tp_net = skb_network_offset(skb); 3605 if (skb_vlan_tag_present(skb)) { 3606 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3607 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3608 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3609 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3610 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3611 struct net_device *dev; 3612 3613 rcu_read_lock(); 3614 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3615 if (dev) { 3616 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3617 aux.tp_vlan_tpid = ntohs(skb->protocol); 3618 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3619 } else { 3620 aux.tp_vlan_tci = 0; 3621 aux.tp_vlan_tpid = 0; 3622 } 3623 rcu_read_unlock(); 3624 } else { 3625 aux.tp_vlan_tci = 0; 3626 aux.tp_vlan_tpid = 0; 3627 } 3628 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3629 } 3630 3631 /* 3632 * Free or return the buffer as appropriate. Again this 3633 * hides all the races and re-entrancy issues from us. 3634 */ 3635 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3636 3637 out_free: 3638 skb_free_datagram(sk, skb); 3639 out: 3640 return err; 3641 } 3642 3643 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3644 int peer) 3645 { 3646 struct net_device *dev; 3647 struct sock *sk = sock->sk; 3648 3649 if (peer) 3650 return -EOPNOTSUPP; 3651 3652 uaddr->sa_family = AF_PACKET; 3653 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min)); 3654 rcu_read_lock(); 3655 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3656 if (dev) 3657 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min)); 3658 rcu_read_unlock(); 3659 3660 return sizeof(*uaddr); 3661 } 3662 3663 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3664 int peer) 3665 { 3666 struct net_device *dev; 3667 struct sock *sk = sock->sk; 3668 struct packet_sock *po = pkt_sk(sk); 3669 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3670 int ifindex; 3671 3672 if (peer) 3673 return -EOPNOTSUPP; 3674 3675 ifindex = READ_ONCE(po->ifindex); 3676 sll->sll_family = AF_PACKET; 3677 sll->sll_ifindex = ifindex; 3678 sll->sll_protocol = READ_ONCE(po->num); 3679 sll->sll_pkttype = 0; 3680 rcu_read_lock(); 3681 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3682 if (dev) { 3683 sll->sll_hatype = dev->type; 3684 sll->sll_halen = dev->addr_len; 3685 3686 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3687 memcpy(((struct sockaddr_storage *)sll)->__data + 3688 offsetof(struct sockaddr_ll, sll_addr) - 3689 offsetofend(struct sockaddr_ll, sll_family), 3690 dev->dev_addr, dev->addr_len); 3691 } else { 3692 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3693 sll->sll_halen = 0; 3694 } 3695 rcu_read_unlock(); 3696 3697 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3698 } 3699 3700 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3701 int what) 3702 { 3703 switch (i->type) { 3704 case PACKET_MR_MULTICAST: 3705 if (i->alen != dev->addr_len) 3706 return -EINVAL; 3707 if (what > 0) 3708 return dev_mc_add(dev, i->addr); 3709 else 3710 return dev_mc_del(dev, i->addr); 3711 break; 3712 case PACKET_MR_PROMISC: 3713 return dev_set_promiscuity(dev, what); 3714 case PACKET_MR_ALLMULTI: 3715 return dev_set_allmulti(dev, what); 3716 case PACKET_MR_UNICAST: 3717 if (i->alen != dev->addr_len) 3718 return -EINVAL; 3719 if (what > 0) 3720 return dev_uc_add(dev, i->addr); 3721 else 3722 return dev_uc_del(dev, i->addr); 3723 break; 3724 default: 3725 break; 3726 } 3727 return 0; 3728 } 3729 3730 static void packet_dev_mclist_delete(struct net_device *dev, 3731 struct packet_mclist **mlp) 3732 { 3733 struct packet_mclist *ml; 3734 3735 while ((ml = *mlp) != NULL) { 3736 if (ml->ifindex == dev->ifindex) { 3737 packet_dev_mc(dev, ml, -1); 3738 *mlp = ml->next; 3739 kfree(ml); 3740 } else 3741 mlp = &ml->next; 3742 } 3743 } 3744 3745 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3746 { 3747 struct packet_sock *po = pkt_sk(sk); 3748 struct packet_mclist *ml, *i; 3749 struct net_device *dev; 3750 int err; 3751 3752 rtnl_lock(); 3753 3754 err = -ENODEV; 3755 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3756 if (!dev) 3757 goto done; 3758 3759 err = -EINVAL; 3760 if (mreq->mr_alen > dev->addr_len) 3761 goto done; 3762 3763 err = -ENOBUFS; 3764 i = kmalloc(sizeof(*i), GFP_KERNEL); 3765 if (i == NULL) 3766 goto done; 3767 3768 err = 0; 3769 for (ml = po->mclist; ml; ml = ml->next) { 3770 if (ml->ifindex == mreq->mr_ifindex && 3771 ml->type == mreq->mr_type && 3772 ml->alen == mreq->mr_alen && 3773 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3774 ml->count++; 3775 /* Free the new element ... */ 3776 kfree(i); 3777 goto done; 3778 } 3779 } 3780 3781 i->type = mreq->mr_type; 3782 i->ifindex = mreq->mr_ifindex; 3783 i->alen = mreq->mr_alen; 3784 memcpy(i->addr, mreq->mr_address, i->alen); 3785 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3786 i->count = 1; 3787 i->next = po->mclist; 3788 po->mclist = i; 3789 err = packet_dev_mc(dev, i, 1); 3790 if (err) { 3791 po->mclist = i->next; 3792 kfree(i); 3793 } 3794 3795 done: 3796 rtnl_unlock(); 3797 return err; 3798 } 3799 3800 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3801 { 3802 struct packet_mclist *ml, **mlp; 3803 3804 rtnl_lock(); 3805 3806 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3807 if (ml->ifindex == mreq->mr_ifindex && 3808 ml->type == mreq->mr_type && 3809 ml->alen == mreq->mr_alen && 3810 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3811 if (--ml->count == 0) { 3812 struct net_device *dev; 3813 *mlp = ml->next; 3814 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3815 if (dev) 3816 packet_dev_mc(dev, ml, -1); 3817 kfree(ml); 3818 } 3819 break; 3820 } 3821 } 3822 rtnl_unlock(); 3823 return 0; 3824 } 3825 3826 static void packet_flush_mclist(struct sock *sk) 3827 { 3828 struct packet_sock *po = pkt_sk(sk); 3829 struct packet_mclist *ml; 3830 3831 if (!po->mclist) 3832 return; 3833 3834 rtnl_lock(); 3835 while ((ml = po->mclist) != NULL) { 3836 struct net_device *dev; 3837 3838 po->mclist = ml->next; 3839 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3840 if (dev != NULL) 3841 packet_dev_mc(dev, ml, -1); 3842 kfree(ml); 3843 } 3844 rtnl_unlock(); 3845 } 3846 3847 static int 3848 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3849 unsigned int optlen) 3850 { 3851 struct sock *sk = sock->sk; 3852 struct packet_sock *po = pkt_sk(sk); 3853 int ret; 3854 3855 if (level != SOL_PACKET) 3856 return -ENOPROTOOPT; 3857 3858 switch (optname) { 3859 case PACKET_ADD_MEMBERSHIP: 3860 case PACKET_DROP_MEMBERSHIP: 3861 { 3862 struct packet_mreq_max mreq; 3863 int len = optlen; 3864 memset(&mreq, 0, sizeof(mreq)); 3865 if (len < sizeof(struct packet_mreq)) 3866 return -EINVAL; 3867 if (len > sizeof(mreq)) 3868 len = sizeof(mreq); 3869 if (copy_from_sockptr(&mreq, optval, len)) 3870 return -EFAULT; 3871 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3872 return -EINVAL; 3873 if (optname == PACKET_ADD_MEMBERSHIP) 3874 ret = packet_mc_add(sk, &mreq); 3875 else 3876 ret = packet_mc_drop(sk, &mreq); 3877 return ret; 3878 } 3879 3880 case PACKET_RX_RING: 3881 case PACKET_TX_RING: 3882 { 3883 union tpacket_req_u req_u; 3884 3885 ret = -EINVAL; 3886 lock_sock(sk); 3887 switch (po->tp_version) { 3888 case TPACKET_V1: 3889 case TPACKET_V2: 3890 if (optlen < sizeof(req_u.req)) 3891 break; 3892 ret = copy_from_sockptr(&req_u.req, optval, 3893 sizeof(req_u.req)) ? 3894 -EINVAL : 0; 3895 break; 3896 case TPACKET_V3: 3897 default: 3898 if (optlen < sizeof(req_u.req3)) 3899 break; 3900 ret = copy_from_sockptr(&req_u.req3, optval, 3901 sizeof(req_u.req3)) ? 3902 -EINVAL : 0; 3903 break; 3904 } 3905 if (!ret) 3906 ret = packet_set_ring(sk, &req_u, 0, 3907 optname == PACKET_TX_RING); 3908 release_sock(sk); 3909 return ret; 3910 } 3911 case PACKET_COPY_THRESH: 3912 { 3913 int val; 3914 3915 if (optlen != sizeof(val)) 3916 return -EINVAL; 3917 if (copy_from_sockptr(&val, optval, sizeof(val))) 3918 return -EFAULT; 3919 3920 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3921 return 0; 3922 } 3923 case PACKET_VERSION: 3924 { 3925 int val; 3926 3927 if (optlen != sizeof(val)) 3928 return -EINVAL; 3929 if (copy_from_sockptr(&val, optval, sizeof(val))) 3930 return -EFAULT; 3931 switch (val) { 3932 case TPACKET_V1: 3933 case TPACKET_V2: 3934 case TPACKET_V3: 3935 break; 3936 default: 3937 return -EINVAL; 3938 } 3939 lock_sock(sk); 3940 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3941 ret = -EBUSY; 3942 } else { 3943 po->tp_version = val; 3944 ret = 0; 3945 } 3946 release_sock(sk); 3947 return ret; 3948 } 3949 case PACKET_RESERVE: 3950 { 3951 unsigned int val; 3952 3953 if (optlen != sizeof(val)) 3954 return -EINVAL; 3955 if (copy_from_sockptr(&val, optval, sizeof(val))) 3956 return -EFAULT; 3957 if (val > INT_MAX) 3958 return -EINVAL; 3959 lock_sock(sk); 3960 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3961 ret = -EBUSY; 3962 } else { 3963 po->tp_reserve = val; 3964 ret = 0; 3965 } 3966 release_sock(sk); 3967 return ret; 3968 } 3969 case PACKET_LOSS: 3970 { 3971 unsigned int val; 3972 3973 if (optlen != sizeof(val)) 3974 return -EINVAL; 3975 if (copy_from_sockptr(&val, optval, sizeof(val))) 3976 return -EFAULT; 3977 3978 lock_sock(sk); 3979 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3980 ret = -EBUSY; 3981 } else { 3982 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3983 ret = 0; 3984 } 3985 release_sock(sk); 3986 return ret; 3987 } 3988 case PACKET_AUXDATA: 3989 { 3990 int val; 3991 3992 if (optlen < sizeof(val)) 3993 return -EINVAL; 3994 if (copy_from_sockptr(&val, optval, sizeof(val))) 3995 return -EFAULT; 3996 3997 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3998 return 0; 3999 } 4000 case PACKET_ORIGDEV: 4001 { 4002 int val; 4003 4004 if (optlen < sizeof(val)) 4005 return -EINVAL; 4006 if (copy_from_sockptr(&val, optval, sizeof(val))) 4007 return -EFAULT; 4008 4009 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 4010 return 0; 4011 } 4012 case PACKET_VNET_HDR: 4013 case PACKET_VNET_HDR_SZ: 4014 { 4015 int val, hdr_len; 4016 4017 if (sock->type != SOCK_RAW) 4018 return -EINVAL; 4019 if (optlen < sizeof(val)) 4020 return -EINVAL; 4021 if (copy_from_sockptr(&val, optval, sizeof(val))) 4022 return -EFAULT; 4023 4024 if (optname == PACKET_VNET_HDR_SZ) { 4025 if (val && val != sizeof(struct virtio_net_hdr) && 4026 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 4027 return -EINVAL; 4028 hdr_len = val; 4029 } else { 4030 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 4031 } 4032 lock_sock(sk); 4033 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 4034 ret = -EBUSY; 4035 } else { 4036 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 4037 ret = 0; 4038 } 4039 release_sock(sk); 4040 return ret; 4041 } 4042 case PACKET_TIMESTAMP: 4043 { 4044 int val; 4045 4046 if (optlen != sizeof(val)) 4047 return -EINVAL; 4048 if (copy_from_sockptr(&val, optval, sizeof(val))) 4049 return -EFAULT; 4050 4051 WRITE_ONCE(po->tp_tstamp, val); 4052 return 0; 4053 } 4054 case PACKET_FANOUT: 4055 { 4056 struct fanout_args args = { 0 }; 4057 4058 if (optlen != sizeof(int) && optlen != sizeof(args)) 4059 return -EINVAL; 4060 if (copy_from_sockptr(&args, optval, optlen)) 4061 return -EFAULT; 4062 4063 return fanout_add(sk, &args); 4064 } 4065 case PACKET_FANOUT_DATA: 4066 { 4067 /* Paired with the WRITE_ONCE() in fanout_add() */ 4068 if (!READ_ONCE(po->fanout)) 4069 return -EINVAL; 4070 4071 return fanout_set_data(po, optval, optlen); 4072 } 4073 case PACKET_IGNORE_OUTGOING: 4074 { 4075 int val; 4076 4077 if (optlen != sizeof(val)) 4078 return -EINVAL; 4079 if (copy_from_sockptr(&val, optval, sizeof(val))) 4080 return -EFAULT; 4081 if (val < 0 || val > 1) 4082 return -EINVAL; 4083 4084 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4085 return 0; 4086 } 4087 case PACKET_TX_HAS_OFF: 4088 { 4089 unsigned int val; 4090 4091 if (optlen != sizeof(val)) 4092 return -EINVAL; 4093 if (copy_from_sockptr(&val, optval, sizeof(val))) 4094 return -EFAULT; 4095 4096 lock_sock(sk); 4097 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4098 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4099 4100 release_sock(sk); 4101 return 0; 4102 } 4103 case PACKET_QDISC_BYPASS: 4104 { 4105 int val; 4106 4107 if (optlen != sizeof(val)) 4108 return -EINVAL; 4109 if (copy_from_sockptr(&val, optval, sizeof(val))) 4110 return -EFAULT; 4111 4112 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4113 return 0; 4114 } 4115 default: 4116 return -ENOPROTOOPT; 4117 } 4118 } 4119 4120 static int packet_getsockopt(struct socket *sock, int level, int optname, 4121 char __user *optval, int __user *optlen) 4122 { 4123 int len; 4124 int val, lv = sizeof(val); 4125 struct sock *sk = sock->sk; 4126 struct packet_sock *po = pkt_sk(sk); 4127 void *data = &val; 4128 union tpacket_stats_u st; 4129 struct tpacket_rollover_stats rstats; 4130 int drops; 4131 4132 if (level != SOL_PACKET) 4133 return -ENOPROTOOPT; 4134 4135 if (get_user(len, optlen)) 4136 return -EFAULT; 4137 4138 if (len < 0) 4139 return -EINVAL; 4140 4141 switch (optname) { 4142 case PACKET_STATISTICS: 4143 spin_lock_bh(&sk->sk_receive_queue.lock); 4144 memcpy(&st, &po->stats, sizeof(st)); 4145 memset(&po->stats, 0, sizeof(po->stats)); 4146 spin_unlock_bh(&sk->sk_receive_queue.lock); 4147 drops = atomic_xchg(&po->tp_drops, 0); 4148 4149 if (po->tp_version == TPACKET_V3) { 4150 lv = sizeof(struct tpacket_stats_v3); 4151 st.stats3.tp_drops = drops; 4152 st.stats3.tp_packets += drops; 4153 data = &st.stats3; 4154 } else { 4155 lv = sizeof(struct tpacket_stats); 4156 st.stats1.tp_drops = drops; 4157 st.stats1.tp_packets += drops; 4158 data = &st.stats1; 4159 } 4160 4161 break; 4162 case PACKET_AUXDATA: 4163 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4164 break; 4165 case PACKET_ORIGDEV: 4166 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4167 break; 4168 case PACKET_VNET_HDR: 4169 val = !!READ_ONCE(po->vnet_hdr_sz); 4170 break; 4171 case PACKET_VNET_HDR_SZ: 4172 val = READ_ONCE(po->vnet_hdr_sz); 4173 break; 4174 case PACKET_COPY_THRESH: 4175 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4176 break; 4177 case PACKET_VERSION: 4178 val = po->tp_version; 4179 break; 4180 case PACKET_HDRLEN: 4181 if (len > sizeof(int)) 4182 len = sizeof(int); 4183 if (len < sizeof(int)) 4184 return -EINVAL; 4185 if (copy_from_user(&val, optval, len)) 4186 return -EFAULT; 4187 switch (val) { 4188 case TPACKET_V1: 4189 val = sizeof(struct tpacket_hdr); 4190 break; 4191 case TPACKET_V2: 4192 val = sizeof(struct tpacket2_hdr); 4193 break; 4194 case TPACKET_V3: 4195 val = sizeof(struct tpacket3_hdr); 4196 break; 4197 default: 4198 return -EINVAL; 4199 } 4200 break; 4201 case PACKET_RESERVE: 4202 val = po->tp_reserve; 4203 break; 4204 case PACKET_LOSS: 4205 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4206 break; 4207 case PACKET_TIMESTAMP: 4208 val = READ_ONCE(po->tp_tstamp); 4209 break; 4210 case PACKET_FANOUT: 4211 val = (po->fanout ? 4212 ((u32)po->fanout->id | 4213 ((u32)po->fanout->type << 16) | 4214 ((u32)po->fanout->flags << 24)) : 4215 0); 4216 break; 4217 case PACKET_IGNORE_OUTGOING: 4218 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4219 break; 4220 case PACKET_ROLLOVER_STATS: 4221 if (!po->rollover) 4222 return -EINVAL; 4223 rstats.tp_all = atomic_long_read(&po->rollover->num); 4224 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4225 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4226 data = &rstats; 4227 lv = sizeof(rstats); 4228 break; 4229 case PACKET_TX_HAS_OFF: 4230 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4231 break; 4232 case PACKET_QDISC_BYPASS: 4233 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4234 break; 4235 default: 4236 return -ENOPROTOOPT; 4237 } 4238 4239 if (len > lv) 4240 len = lv; 4241 if (put_user(len, optlen)) 4242 return -EFAULT; 4243 if (copy_to_user(optval, data, len)) 4244 return -EFAULT; 4245 return 0; 4246 } 4247 4248 static int packet_notifier(struct notifier_block *this, 4249 unsigned long msg, void *ptr) 4250 { 4251 struct sock *sk; 4252 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4253 struct net *net = dev_net(dev); 4254 4255 rcu_read_lock(); 4256 sk_for_each_rcu(sk, &net->packet.sklist) { 4257 struct packet_sock *po = pkt_sk(sk); 4258 4259 switch (msg) { 4260 case NETDEV_UNREGISTER: 4261 if (po->mclist) 4262 packet_dev_mclist_delete(dev, &po->mclist); 4263 fallthrough; 4264 4265 case NETDEV_DOWN: 4266 if (dev->ifindex == po->ifindex) { 4267 spin_lock(&po->bind_lock); 4268 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4269 __unregister_prot_hook(sk, false); 4270 sk->sk_err = ENETDOWN; 4271 if (!sock_flag(sk, SOCK_DEAD)) 4272 sk_error_report(sk); 4273 } 4274 if (msg == NETDEV_UNREGISTER) { 4275 packet_cached_dev_reset(po); 4276 WRITE_ONCE(po->ifindex, -1); 4277 netdev_put(po->prot_hook.dev, 4278 &po->prot_hook.dev_tracker); 4279 po->prot_hook.dev = NULL; 4280 } 4281 spin_unlock(&po->bind_lock); 4282 } 4283 break; 4284 case NETDEV_UP: 4285 if (dev->ifindex == po->ifindex) { 4286 spin_lock(&po->bind_lock); 4287 if (po->num) 4288 register_prot_hook(sk); 4289 spin_unlock(&po->bind_lock); 4290 } 4291 break; 4292 } 4293 } 4294 rcu_read_unlock(); 4295 return NOTIFY_DONE; 4296 } 4297 4298 4299 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4300 unsigned long arg) 4301 { 4302 struct sock *sk = sock->sk; 4303 4304 switch (cmd) { 4305 case SIOCOUTQ: 4306 { 4307 int amount = sk_wmem_alloc_get(sk); 4308 4309 return put_user(amount, (int __user *)arg); 4310 } 4311 case SIOCINQ: 4312 { 4313 struct sk_buff *skb; 4314 int amount = 0; 4315 4316 spin_lock_bh(&sk->sk_receive_queue.lock); 4317 skb = skb_peek(&sk->sk_receive_queue); 4318 if (skb) 4319 amount = skb->len; 4320 spin_unlock_bh(&sk->sk_receive_queue.lock); 4321 return put_user(amount, (int __user *)arg); 4322 } 4323 #ifdef CONFIG_INET 4324 case SIOCADDRT: 4325 case SIOCDELRT: 4326 case SIOCDARP: 4327 case SIOCGARP: 4328 case SIOCSARP: 4329 case SIOCGIFADDR: 4330 case SIOCSIFADDR: 4331 case SIOCGIFBRDADDR: 4332 case SIOCSIFBRDADDR: 4333 case SIOCGIFNETMASK: 4334 case SIOCSIFNETMASK: 4335 case SIOCGIFDSTADDR: 4336 case SIOCSIFDSTADDR: 4337 case SIOCSIFFLAGS: 4338 return inet_dgram_ops.ioctl(sock, cmd, arg); 4339 #endif 4340 4341 default: 4342 return -ENOIOCTLCMD; 4343 } 4344 return 0; 4345 } 4346 4347 static __poll_t packet_poll(struct file *file, struct socket *sock, 4348 poll_table *wait) 4349 { 4350 struct sock *sk = sock->sk; 4351 struct packet_sock *po = pkt_sk(sk); 4352 __poll_t mask = datagram_poll(file, sock, wait); 4353 4354 spin_lock_bh(&sk->sk_receive_queue.lock); 4355 if (po->rx_ring.pg_vec) { 4356 if (!packet_previous_rx_frame(po, &po->rx_ring, 4357 TP_STATUS_KERNEL)) 4358 mask |= EPOLLIN | EPOLLRDNORM; 4359 } 4360 packet_rcv_try_clear_pressure(po); 4361 spin_unlock_bh(&sk->sk_receive_queue.lock); 4362 spin_lock_bh(&sk->sk_write_queue.lock); 4363 if (po->tx_ring.pg_vec) { 4364 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4365 mask |= EPOLLOUT | EPOLLWRNORM; 4366 } 4367 spin_unlock_bh(&sk->sk_write_queue.lock); 4368 return mask; 4369 } 4370 4371 4372 /* Dirty? Well, I still did not learn better way to account 4373 * for user mmaps. 4374 */ 4375 4376 static void packet_mm_open(struct vm_area_struct *vma) 4377 { 4378 struct file *file = vma->vm_file; 4379 struct socket *sock = file->private_data; 4380 struct sock *sk = sock->sk; 4381 4382 if (sk) 4383 atomic_long_inc(&pkt_sk(sk)->mapped); 4384 } 4385 4386 static void packet_mm_close(struct vm_area_struct *vma) 4387 { 4388 struct file *file = vma->vm_file; 4389 struct socket *sock = file->private_data; 4390 struct sock *sk = sock->sk; 4391 4392 if (sk) 4393 atomic_long_dec(&pkt_sk(sk)->mapped); 4394 } 4395 4396 static const struct vm_operations_struct packet_mmap_ops = { 4397 .open = packet_mm_open, 4398 .close = packet_mm_close, 4399 }; 4400 4401 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4402 unsigned int len) 4403 { 4404 int i; 4405 4406 for (i = 0; i < len; i++) { 4407 if (likely(pg_vec[i].buffer)) { 4408 if (is_vmalloc_addr(pg_vec[i].buffer)) 4409 vfree(pg_vec[i].buffer); 4410 else 4411 free_pages((unsigned long)pg_vec[i].buffer, 4412 order); 4413 pg_vec[i].buffer = NULL; 4414 } 4415 } 4416 kfree(pg_vec); 4417 } 4418 4419 static char *alloc_one_pg_vec_page(unsigned long order) 4420 { 4421 char *buffer; 4422 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4423 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4424 4425 buffer = (char *) __get_free_pages(gfp_flags, order); 4426 if (buffer) 4427 return buffer; 4428 4429 /* __get_free_pages failed, fall back to vmalloc */ 4430 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4431 if (buffer) 4432 return buffer; 4433 4434 /* vmalloc failed, lets dig into swap here */ 4435 gfp_flags &= ~__GFP_NORETRY; 4436 buffer = (char *) __get_free_pages(gfp_flags, order); 4437 if (buffer) 4438 return buffer; 4439 4440 /* complete and utter failure */ 4441 return NULL; 4442 } 4443 4444 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4445 { 4446 unsigned int block_nr = req->tp_block_nr; 4447 struct pgv *pg_vec; 4448 int i; 4449 4450 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN); 4451 if (unlikely(!pg_vec)) 4452 goto out; 4453 4454 for (i = 0; i < block_nr; i++) { 4455 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4456 if (unlikely(!pg_vec[i].buffer)) 4457 goto out_free_pgvec; 4458 } 4459 4460 out: 4461 return pg_vec; 4462 4463 out_free_pgvec: 4464 free_pg_vec(pg_vec, order, block_nr); 4465 pg_vec = NULL; 4466 goto out; 4467 } 4468 4469 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4470 int closing, int tx_ring) 4471 { 4472 struct pgv *pg_vec = NULL; 4473 struct packet_sock *po = pkt_sk(sk); 4474 unsigned long *rx_owner_map = NULL; 4475 int was_running, order = 0; 4476 struct packet_ring_buffer *rb; 4477 struct sk_buff_head *rb_queue; 4478 __be16 num; 4479 int err; 4480 /* Added to avoid minimal code churn */ 4481 struct tpacket_req *req = &req_u->req; 4482 4483 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4484 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4485 4486 err = -EBUSY; 4487 if (!closing) { 4488 if (atomic_long_read(&po->mapped)) 4489 goto out; 4490 if (packet_read_pending(rb)) 4491 goto out; 4492 } 4493 4494 if (req->tp_block_nr) { 4495 unsigned int min_frame_size; 4496 4497 /* Sanity tests and some calculations */ 4498 err = -EBUSY; 4499 if (unlikely(rb->pg_vec)) 4500 goto out; 4501 4502 switch (po->tp_version) { 4503 case TPACKET_V1: 4504 po->tp_hdrlen = TPACKET_HDRLEN; 4505 break; 4506 case TPACKET_V2: 4507 po->tp_hdrlen = TPACKET2_HDRLEN; 4508 break; 4509 case TPACKET_V3: 4510 po->tp_hdrlen = TPACKET3_HDRLEN; 4511 break; 4512 } 4513 4514 err = -EINVAL; 4515 if (unlikely((int)req->tp_block_size <= 0)) 4516 goto out; 4517 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4518 goto out; 4519 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4520 if (po->tp_version >= TPACKET_V3 && 4521 req->tp_block_size < 4522 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4523 goto out; 4524 if (unlikely(req->tp_frame_size < min_frame_size)) 4525 goto out; 4526 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4527 goto out; 4528 4529 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4530 if (unlikely(rb->frames_per_block == 0)) 4531 goto out; 4532 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4533 goto out; 4534 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4535 req->tp_frame_nr)) 4536 goto out; 4537 4538 err = -ENOMEM; 4539 order = get_order(req->tp_block_size); 4540 pg_vec = alloc_pg_vec(req, order); 4541 if (unlikely(!pg_vec)) 4542 goto out; 4543 switch (po->tp_version) { 4544 case TPACKET_V3: 4545 /* Block transmit is not supported yet */ 4546 if (!tx_ring) { 4547 init_prb_bdqc(po, rb, pg_vec, req_u); 4548 } else { 4549 struct tpacket_req3 *req3 = &req_u->req3; 4550 4551 if (req3->tp_retire_blk_tov || 4552 req3->tp_sizeof_priv || 4553 req3->tp_feature_req_word) { 4554 err = -EINVAL; 4555 goto out_free_pg_vec; 4556 } 4557 } 4558 break; 4559 default: 4560 if (!tx_ring) { 4561 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4562 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4563 if (!rx_owner_map) 4564 goto out_free_pg_vec; 4565 } 4566 break; 4567 } 4568 } 4569 /* Done */ 4570 else { 4571 err = -EINVAL; 4572 if (unlikely(req->tp_frame_nr)) 4573 goto out; 4574 } 4575 4576 4577 /* Detach socket from network */ 4578 spin_lock(&po->bind_lock); 4579 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4580 num = po->num; 4581 if (was_running) { 4582 WRITE_ONCE(po->num, 0); 4583 __unregister_prot_hook(sk, false); 4584 } 4585 spin_unlock(&po->bind_lock); 4586 4587 synchronize_net(); 4588 4589 err = -EBUSY; 4590 mutex_lock(&po->pg_vec_lock); 4591 if (closing || atomic_long_read(&po->mapped) == 0) { 4592 err = 0; 4593 spin_lock_bh(&rb_queue->lock); 4594 swap(rb->pg_vec, pg_vec); 4595 if (po->tp_version <= TPACKET_V2) 4596 swap(rb->rx_owner_map, rx_owner_map); 4597 rb->frame_max = (req->tp_frame_nr - 1); 4598 rb->head = 0; 4599 rb->frame_size = req->tp_frame_size; 4600 spin_unlock_bh(&rb_queue->lock); 4601 4602 swap(rb->pg_vec_order, order); 4603 swap(rb->pg_vec_len, req->tp_block_nr); 4604 4605 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4606 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4607 tpacket_rcv : packet_rcv; 4608 skb_queue_purge(rb_queue); 4609 if (atomic_long_read(&po->mapped)) 4610 pr_err("packet_mmap: vma is busy: %ld\n", 4611 atomic_long_read(&po->mapped)); 4612 } 4613 mutex_unlock(&po->pg_vec_lock); 4614 4615 spin_lock(&po->bind_lock); 4616 if (was_running) { 4617 WRITE_ONCE(po->num, num); 4618 register_prot_hook(sk); 4619 } 4620 spin_unlock(&po->bind_lock); 4621 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4622 /* Because we don't support block-based V3 on tx-ring */ 4623 if (!tx_ring) 4624 prb_shutdown_retire_blk_timer(po, rb_queue); 4625 } 4626 4627 out_free_pg_vec: 4628 if (pg_vec) { 4629 bitmap_free(rx_owner_map); 4630 free_pg_vec(pg_vec, order, req->tp_block_nr); 4631 } 4632 out: 4633 return err; 4634 } 4635 4636 static int packet_mmap(struct file *file, struct socket *sock, 4637 struct vm_area_struct *vma) 4638 { 4639 struct sock *sk = sock->sk; 4640 struct packet_sock *po = pkt_sk(sk); 4641 unsigned long size, expected_size; 4642 struct packet_ring_buffer *rb; 4643 unsigned long start; 4644 int err = -EINVAL; 4645 int i; 4646 4647 if (vma->vm_pgoff) 4648 return -EINVAL; 4649 4650 mutex_lock(&po->pg_vec_lock); 4651 4652 expected_size = 0; 4653 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4654 if (rb->pg_vec) { 4655 expected_size += rb->pg_vec_len 4656 * rb->pg_vec_pages 4657 * PAGE_SIZE; 4658 } 4659 } 4660 4661 if (expected_size == 0) 4662 goto out; 4663 4664 size = vma->vm_end - vma->vm_start; 4665 if (size != expected_size) 4666 goto out; 4667 4668 start = vma->vm_start; 4669 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4670 if (rb->pg_vec == NULL) 4671 continue; 4672 4673 for (i = 0; i < rb->pg_vec_len; i++) { 4674 struct page *page; 4675 void *kaddr = rb->pg_vec[i].buffer; 4676 int pg_num; 4677 4678 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4679 page = pgv_to_page(kaddr); 4680 err = vm_insert_page(vma, start, page); 4681 if (unlikely(err)) 4682 goto out; 4683 start += PAGE_SIZE; 4684 kaddr += PAGE_SIZE; 4685 } 4686 } 4687 } 4688 4689 atomic_long_inc(&po->mapped); 4690 vma->vm_ops = &packet_mmap_ops; 4691 err = 0; 4692 4693 out: 4694 mutex_unlock(&po->pg_vec_lock); 4695 return err; 4696 } 4697 4698 static const struct proto_ops packet_ops_spkt = { 4699 .family = PF_PACKET, 4700 .owner = THIS_MODULE, 4701 .release = packet_release, 4702 .bind = packet_bind_spkt, 4703 .connect = sock_no_connect, 4704 .socketpair = sock_no_socketpair, 4705 .accept = sock_no_accept, 4706 .getname = packet_getname_spkt, 4707 .poll = datagram_poll, 4708 .ioctl = packet_ioctl, 4709 .gettstamp = sock_gettstamp, 4710 .listen = sock_no_listen, 4711 .shutdown = sock_no_shutdown, 4712 .sendmsg = packet_sendmsg_spkt, 4713 .recvmsg = packet_recvmsg, 4714 .mmap = sock_no_mmap, 4715 }; 4716 4717 static const struct proto_ops packet_ops = { 4718 .family = PF_PACKET, 4719 .owner = THIS_MODULE, 4720 .release = packet_release, 4721 .bind = packet_bind, 4722 .connect = sock_no_connect, 4723 .socketpair = sock_no_socketpair, 4724 .accept = sock_no_accept, 4725 .getname = packet_getname, 4726 .poll = packet_poll, 4727 .ioctl = packet_ioctl, 4728 .gettstamp = sock_gettstamp, 4729 .listen = sock_no_listen, 4730 .shutdown = sock_no_shutdown, 4731 .setsockopt = packet_setsockopt, 4732 .getsockopt = packet_getsockopt, 4733 .sendmsg = packet_sendmsg, 4734 .recvmsg = packet_recvmsg, 4735 .mmap = packet_mmap, 4736 }; 4737 4738 static const struct net_proto_family packet_family_ops = { 4739 .family = PF_PACKET, 4740 .create = packet_create, 4741 .owner = THIS_MODULE, 4742 }; 4743 4744 static struct notifier_block packet_netdev_notifier = { 4745 .notifier_call = packet_notifier, 4746 }; 4747 4748 #ifdef CONFIG_PROC_FS 4749 4750 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4751 __acquires(RCU) 4752 { 4753 struct net *net = seq_file_net(seq); 4754 4755 rcu_read_lock(); 4756 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4757 } 4758 4759 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4760 { 4761 struct net *net = seq_file_net(seq); 4762 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4763 } 4764 4765 static void packet_seq_stop(struct seq_file *seq, void *v) 4766 __releases(RCU) 4767 { 4768 rcu_read_unlock(); 4769 } 4770 4771 static int packet_seq_show(struct seq_file *seq, void *v) 4772 { 4773 if (v == SEQ_START_TOKEN) 4774 seq_printf(seq, 4775 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4776 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4777 else { 4778 struct sock *s = sk_entry(v); 4779 const struct packet_sock *po = pkt_sk(s); 4780 4781 seq_printf(seq, 4782 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4783 s, 4784 refcount_read(&s->sk_refcnt), 4785 s->sk_type, 4786 ntohs(READ_ONCE(po->num)), 4787 READ_ONCE(po->ifindex), 4788 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4789 atomic_read(&s->sk_rmem_alloc), 4790 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4791 sock_i_ino(s)); 4792 } 4793 4794 return 0; 4795 } 4796 4797 static const struct seq_operations packet_seq_ops = { 4798 .start = packet_seq_start, 4799 .next = packet_seq_next, 4800 .stop = packet_seq_stop, 4801 .show = packet_seq_show, 4802 }; 4803 #endif 4804 4805 static int __net_init packet_net_init(struct net *net) 4806 { 4807 mutex_init(&net->packet.sklist_lock); 4808 INIT_HLIST_HEAD(&net->packet.sklist); 4809 4810 #ifdef CONFIG_PROC_FS 4811 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4812 sizeof(struct seq_net_private))) 4813 return -ENOMEM; 4814 #endif /* CONFIG_PROC_FS */ 4815 4816 return 0; 4817 } 4818 4819 static void __net_exit packet_net_exit(struct net *net) 4820 { 4821 remove_proc_entry("packet", net->proc_net); 4822 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4823 } 4824 4825 static struct pernet_operations packet_net_ops = { 4826 .init = packet_net_init, 4827 .exit = packet_net_exit, 4828 }; 4829 4830 4831 static void __exit packet_exit(void) 4832 { 4833 sock_unregister(PF_PACKET); 4834 proto_unregister(&packet_proto); 4835 unregister_netdevice_notifier(&packet_netdev_notifier); 4836 unregister_pernet_subsys(&packet_net_ops); 4837 } 4838 4839 static int __init packet_init(void) 4840 { 4841 int rc; 4842 4843 rc = register_pernet_subsys(&packet_net_ops); 4844 if (rc) 4845 goto out; 4846 rc = register_netdevice_notifier(&packet_netdev_notifier); 4847 if (rc) 4848 goto out_pernet; 4849 rc = proto_register(&packet_proto, 0); 4850 if (rc) 4851 goto out_notifier; 4852 rc = sock_register(&packet_family_ops); 4853 if (rc) 4854 goto out_proto; 4855 4856 return 0; 4857 4858 out_proto: 4859 proto_unregister(&packet_proto); 4860 out_notifier: 4861 unregister_netdevice_notifier(&packet_netdev_notifier); 4862 out_pernet: 4863 unregister_pernet_subsys(&packet_net_ops); 4864 out: 4865 return rc; 4866 } 4867 4868 module_init(packet_init); 4869 module_exit(packet_exit); 4870 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4871 MODULE_LICENSE("GPL"); 4872 MODULE_ALIAS_NETPROTO(PF_PACKET); 4873