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 (packet_sock_flag(po, PACKET_SOCK_RUNNING) && 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 __dev_remove_pack(&po->prot_hook); 1856 1857 /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ 1858 WRITE_ONCE(po->fanout, match); 1859 1860 po->rollover = rollover; 1861 rollover = NULL; 1862 refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); 1863 __fanout_link(sk, po); 1864 err = 0; 1865 } 1866 } 1867 spin_unlock(&po->bind_lock); 1868 1869 if (err && !refcount_read(&match->sk_ref)) { 1870 list_del(&match->list); 1871 kvfree(match); 1872 } 1873 1874 out: 1875 kfree(rollover); 1876 mutex_unlock(&fanout_mutex); 1877 return err; 1878 } 1879 1880 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1881 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1882 * It is the responsibility of the caller to call fanout_release_data() and 1883 * free the returned packet_fanout (after synchronize_net()) 1884 */ 1885 static struct packet_fanout *fanout_release(struct sock *sk) 1886 { 1887 struct packet_sock *po = pkt_sk(sk); 1888 struct packet_fanout *f; 1889 1890 mutex_lock(&fanout_mutex); 1891 f = po->fanout; 1892 if (f) { 1893 po->fanout = NULL; 1894 1895 if (refcount_dec_and_test(&f->sk_ref)) 1896 list_del(&f->list); 1897 else 1898 f = NULL; 1899 } 1900 mutex_unlock(&fanout_mutex); 1901 1902 return f; 1903 } 1904 1905 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1906 struct sk_buff *skb) 1907 { 1908 /* Earlier code assumed this would be a VLAN pkt, double-check 1909 * this now that we have the actual packet in hand. We can only 1910 * do this check on Ethernet devices. 1911 */ 1912 if (unlikely(dev->type != ARPHRD_ETHER)) 1913 return false; 1914 1915 skb_reset_mac_header(skb); 1916 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1917 } 1918 1919 static const struct proto_ops packet_ops; 1920 1921 static const struct proto_ops packet_ops_spkt; 1922 1923 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1924 struct packet_type *pt, struct net_device *orig_dev) 1925 { 1926 struct sock *sk; 1927 struct sockaddr_pkt *spkt; 1928 1929 /* 1930 * When we registered the protocol we saved the socket in the data 1931 * field for just this event. 1932 */ 1933 1934 sk = pt->af_packet_priv; 1935 1936 /* 1937 * Yank back the headers [hope the device set this 1938 * right or kerboom...] 1939 * 1940 * Incoming packets have ll header pulled, 1941 * push it back. 1942 * 1943 * For outgoing ones skb->data == skb_mac_header(skb) 1944 * so that this procedure is noop. 1945 */ 1946 1947 if (skb->pkt_type == PACKET_LOOPBACK) 1948 goto out; 1949 1950 if (!net_eq(dev_net(dev), sock_net(sk))) 1951 goto out; 1952 1953 skb = skb_share_check(skb, GFP_ATOMIC); 1954 if (skb == NULL) 1955 goto oom; 1956 1957 /* drop any routing info */ 1958 skb_dst_drop(skb); 1959 1960 /* drop conntrack reference */ 1961 nf_reset_ct(skb); 1962 1963 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1964 1965 skb_push(skb, skb->data - skb_mac_header(skb)); 1966 1967 /* 1968 * The SOCK_PACKET socket receives _all_ frames. 1969 */ 1970 1971 spkt->spkt_family = dev->type; 1972 strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1973 spkt->spkt_protocol = skb->protocol; 1974 1975 /* 1976 * Charge the memory to the socket. This is done specifically 1977 * to prevent sockets using all the memory up. 1978 */ 1979 1980 if (sock_queue_rcv_skb(sk, skb) == 0) 1981 return 0; 1982 1983 out: 1984 kfree_skb(skb); 1985 oom: 1986 return 0; 1987 } 1988 1989 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) 1990 { 1991 int depth; 1992 1993 if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && 1994 sock->type == SOCK_RAW) { 1995 skb_reset_mac_header(skb); 1996 skb->protocol = dev_parse_header_protocol(skb); 1997 } 1998 1999 /* Move network header to the right position for VLAN tagged packets */ 2000 if (likely(skb->dev->type == ARPHRD_ETHER) && 2001 eth_type_vlan(skb->protocol) && 2002 vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) 2003 skb_set_network_header(skb, depth); 2004 2005 skb_probe_transport_header(skb); 2006 } 2007 2008 /* 2009 * Output a raw packet to a device layer. This bypasses all the other 2010 * protocol layers and you must therefore supply it with a complete frame 2011 */ 2012 2013 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 2014 size_t len) 2015 { 2016 struct sock *sk = sock->sk; 2017 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 2018 struct sk_buff *skb = NULL; 2019 struct net_device *dev; 2020 struct sockcm_cookie sockc; 2021 __be16 proto = 0; 2022 int err; 2023 int extra_len = 0; 2024 2025 /* 2026 * Get and verify the address. 2027 */ 2028 2029 if (saddr) { 2030 if (msg->msg_namelen < sizeof(struct sockaddr)) 2031 return -EINVAL; 2032 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 2033 proto = saddr->spkt_protocol; 2034 } else 2035 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 2036 2037 /* 2038 * Find the device first to size check it 2039 */ 2040 2041 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 2042 retry: 2043 rcu_read_lock(); 2044 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 2045 err = -ENODEV; 2046 if (dev == NULL) 2047 goto out_unlock; 2048 2049 err = -ENETDOWN; 2050 if (!(dev->flags & IFF_UP)) 2051 goto out_unlock; 2052 2053 /* 2054 * You may not queue a frame bigger than the mtu. This is the lowest level 2055 * raw protocol and you must do your own fragmentation at this level. 2056 */ 2057 2058 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2059 if (!netif_supports_nofcs(dev)) { 2060 err = -EPROTONOSUPPORT; 2061 goto out_unlock; 2062 } 2063 extra_len = 4; /* We're doing our own CRC */ 2064 } 2065 2066 err = -EMSGSIZE; 2067 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 2068 goto out_unlock; 2069 2070 if (!skb) { 2071 size_t reserved = LL_RESERVED_SPACE(dev); 2072 int tlen = dev->needed_tailroom; 2073 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 2074 2075 rcu_read_unlock(); 2076 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 2077 if (skb == NULL) 2078 return -ENOBUFS; 2079 /* FIXME: Save some space for broken drivers that write a hard 2080 * header at transmission time by themselves. PPP is the notable 2081 * one here. This should really be fixed at the driver level. 2082 */ 2083 skb_reserve(skb, reserved); 2084 skb_reset_network_header(skb); 2085 2086 /* Try to align data part correctly */ 2087 if (hhlen) { 2088 skb->data -= hhlen; 2089 skb->tail -= hhlen; 2090 if (len < hhlen) 2091 skb_reset_network_header(skb); 2092 } 2093 err = memcpy_from_msg(skb_put(skb, len), msg, len); 2094 if (err) 2095 goto out_free; 2096 goto retry; 2097 } 2098 2099 if (!dev_validate_header(dev, skb->data, len) || !skb->len) { 2100 err = -EINVAL; 2101 goto out_unlock; 2102 } 2103 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 2104 !packet_extra_vlan_len_allowed(dev, skb)) { 2105 err = -EMSGSIZE; 2106 goto out_unlock; 2107 } 2108 2109 sockcm_init(&sockc, sk); 2110 if (msg->msg_controllen) { 2111 err = sock_cmsg_send(sk, msg, &sockc); 2112 if (unlikely(err)) 2113 goto out_unlock; 2114 } 2115 2116 skb->protocol = proto; 2117 skb->dev = dev; 2118 skb->priority = READ_ONCE(sk->sk_priority); 2119 skb->mark = READ_ONCE(sk->sk_mark); 2120 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 2121 skb_setup_tx_timestamp(skb, sockc.tsflags); 2122 2123 if (unlikely(extra_len == 4)) 2124 skb->no_fcs = 1; 2125 2126 packet_parse_headers(skb, sock); 2127 2128 dev_queue_xmit(skb); 2129 rcu_read_unlock(); 2130 return len; 2131 2132 out_unlock: 2133 rcu_read_unlock(); 2134 out_free: 2135 kfree_skb(skb); 2136 return err; 2137 } 2138 2139 static unsigned int run_filter(struct sk_buff *skb, 2140 const struct sock *sk, 2141 unsigned int res) 2142 { 2143 struct sk_filter *filter; 2144 2145 rcu_read_lock(); 2146 filter = rcu_dereference(sk->sk_filter); 2147 if (filter != NULL) 2148 res = bpf_prog_run_clear_cb(filter->prog, skb); 2149 rcu_read_unlock(); 2150 2151 return res; 2152 } 2153 2154 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 2155 size_t *len, int vnet_hdr_sz) 2156 { 2157 struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; 2158 2159 if (*len < vnet_hdr_sz) 2160 return -EINVAL; 2161 *len -= vnet_hdr_sz; 2162 2163 if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) 2164 return -EINVAL; 2165 2166 return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); 2167 } 2168 2169 /* 2170 * This function makes lazy skb cloning in hope that most of packets 2171 * are discarded by BPF. 2172 * 2173 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2174 * and skb->cb are mangled. It works because (and until) packets 2175 * falling here are owned by current CPU. Output packets are cloned 2176 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2177 * sequentially, so that if we return skb to original state on exit, 2178 * we will not harm anyone. 2179 */ 2180 2181 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2182 struct packet_type *pt, struct net_device *orig_dev) 2183 { 2184 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2185 struct sock *sk = NULL; 2186 struct sockaddr_ll *sll; 2187 struct packet_sock *po; 2188 u8 *skb_head = skb->data; 2189 int skb_len = skb->len; 2190 unsigned int snaplen, res; 2191 2192 if (skb->pkt_type == PACKET_LOOPBACK) 2193 goto drop; 2194 2195 sk = pt->af_packet_priv; 2196 po = pkt_sk(sk); 2197 2198 if (!net_eq(dev_net(dev), sock_net(sk))) 2199 goto drop; 2200 2201 skb->dev = dev; 2202 2203 if (dev_has_header(dev)) { 2204 /* The device has an explicit notion of ll header, 2205 * exported to higher levels. 2206 * 2207 * Otherwise, the device hides details of its frame 2208 * structure, so that corresponding packet head is 2209 * never delivered to user. 2210 */ 2211 if (sk->sk_type != SOCK_DGRAM) 2212 skb_push(skb, skb->data - skb_mac_header(skb)); 2213 else if (skb->pkt_type == PACKET_OUTGOING) { 2214 /* Special case: outgoing packets have ll header at head */ 2215 skb_pull(skb, skb_network_offset(skb)); 2216 } 2217 } 2218 2219 snaplen = skb->len; 2220 2221 res = run_filter(skb, sk, snaplen); 2222 if (!res) 2223 goto drop_n_restore; 2224 if (snaplen > res) 2225 snaplen = res; 2226 2227 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2228 goto drop_n_acct; 2229 2230 if (skb_shared(skb)) { 2231 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2232 if (nskb == NULL) 2233 goto drop_n_acct; 2234 2235 if (skb_head != skb->data) { 2236 skb->data = skb_head; 2237 skb->len = skb_len; 2238 } 2239 consume_skb(skb); 2240 skb = nskb; 2241 } 2242 2243 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2244 2245 sll = &PACKET_SKB_CB(skb)->sa.ll; 2246 sll->sll_hatype = dev->type; 2247 sll->sll_pkttype = skb->pkt_type; 2248 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2249 sll->sll_ifindex = orig_dev->ifindex; 2250 else 2251 sll->sll_ifindex = dev->ifindex; 2252 2253 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2254 2255 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2256 * Use their space for storing the original skb length. 2257 */ 2258 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2259 2260 if (pskb_trim(skb, snaplen)) 2261 goto drop_n_acct; 2262 2263 skb_set_owner_r(skb, sk); 2264 skb->dev = NULL; 2265 skb_dst_drop(skb); 2266 2267 /* drop conntrack reference */ 2268 nf_reset_ct(skb); 2269 2270 spin_lock(&sk->sk_receive_queue.lock); 2271 po->stats.stats1.tp_packets++; 2272 sock_skb_set_dropcount(sk, skb); 2273 skb_clear_delivery_time(skb); 2274 __skb_queue_tail(&sk->sk_receive_queue, skb); 2275 spin_unlock(&sk->sk_receive_queue.lock); 2276 sk->sk_data_ready(sk); 2277 return 0; 2278 2279 drop_n_acct: 2280 atomic_inc(&po->tp_drops); 2281 atomic_inc(&sk->sk_drops); 2282 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2283 2284 drop_n_restore: 2285 if (skb_head != skb->data && skb_shared(skb)) { 2286 skb->data = skb_head; 2287 skb->len = skb_len; 2288 } 2289 drop: 2290 sk_skb_reason_drop(sk, skb, drop_reason); 2291 return 0; 2292 } 2293 2294 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2295 struct packet_type *pt, struct net_device *orig_dev) 2296 { 2297 enum skb_drop_reason drop_reason = SKB_CONSUMED; 2298 struct sock *sk = NULL; 2299 struct packet_sock *po; 2300 struct sockaddr_ll *sll; 2301 union tpacket_uhdr h; 2302 u8 *skb_head = skb->data; 2303 int skb_len = skb->len; 2304 unsigned int snaplen, res; 2305 unsigned long status = TP_STATUS_USER; 2306 unsigned short macoff, hdrlen; 2307 unsigned int netoff; 2308 struct sk_buff *copy_skb = NULL; 2309 struct timespec64 ts; 2310 __u32 ts_status; 2311 unsigned int slot_id = 0; 2312 int vnet_hdr_sz = 0; 2313 2314 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2315 * We may add members to them until current aligned size without forcing 2316 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2317 */ 2318 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2319 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2320 2321 if (skb->pkt_type == PACKET_LOOPBACK) 2322 goto drop; 2323 2324 sk = pt->af_packet_priv; 2325 po = pkt_sk(sk); 2326 2327 if (!net_eq(dev_net(dev), sock_net(sk))) 2328 goto drop; 2329 2330 if (dev_has_header(dev)) { 2331 if (sk->sk_type != SOCK_DGRAM) 2332 skb_push(skb, skb->data - skb_mac_header(skb)); 2333 else if (skb->pkt_type == PACKET_OUTGOING) { 2334 /* Special case: outgoing packets have ll header at head */ 2335 skb_pull(skb, skb_network_offset(skb)); 2336 } 2337 } 2338 2339 snaplen = skb->len; 2340 2341 res = run_filter(skb, sk, snaplen); 2342 if (!res) 2343 goto drop_n_restore; 2344 2345 /* If we are flooded, just give up */ 2346 if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { 2347 atomic_inc(&po->tp_drops); 2348 goto drop_n_restore; 2349 } 2350 2351 if (skb->ip_summed == CHECKSUM_PARTIAL) 2352 status |= TP_STATUS_CSUMNOTREADY; 2353 else if (skb->pkt_type != PACKET_OUTGOING && 2354 skb_csum_unnecessary(skb)) 2355 status |= TP_STATUS_CSUM_VALID; 2356 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 2357 status |= TP_STATUS_GSO_TCP; 2358 2359 if (snaplen > res) 2360 snaplen = res; 2361 2362 if (sk->sk_type == SOCK_DGRAM) { 2363 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2364 po->tp_reserve; 2365 } else { 2366 unsigned int maclen = skb_network_offset(skb); 2367 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2368 (maclen < 16 ? 16 : maclen)) + 2369 po->tp_reserve; 2370 vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2371 if (vnet_hdr_sz) 2372 netoff += vnet_hdr_sz; 2373 macoff = netoff - maclen; 2374 } 2375 if (netoff > USHRT_MAX) { 2376 atomic_inc(&po->tp_drops); 2377 goto drop_n_restore; 2378 } 2379 if (po->tp_version <= TPACKET_V2) { 2380 if (macoff + snaplen > po->rx_ring.frame_size) { 2381 if (READ_ONCE(po->copy_thresh) && 2382 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2383 if (skb_shared(skb)) { 2384 copy_skb = skb_clone(skb, GFP_ATOMIC); 2385 } else { 2386 copy_skb = skb_get(skb); 2387 skb_head = skb->data; 2388 } 2389 if (copy_skb) { 2390 memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, 2391 sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); 2392 skb_set_owner_r(copy_skb, sk); 2393 } 2394 } 2395 snaplen = po->rx_ring.frame_size - macoff; 2396 if ((int)snaplen < 0) { 2397 snaplen = 0; 2398 vnet_hdr_sz = 0; 2399 } 2400 } 2401 } else if (unlikely(macoff + snaplen > 2402 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2403 u32 nval; 2404 2405 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2406 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2407 snaplen, nval, macoff); 2408 snaplen = nval; 2409 if (unlikely((int)snaplen < 0)) { 2410 snaplen = 0; 2411 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2412 vnet_hdr_sz = 0; 2413 } 2414 } 2415 spin_lock(&sk->sk_receive_queue.lock); 2416 h.raw = packet_current_rx_frame(po, skb, 2417 TP_STATUS_KERNEL, (macoff+snaplen)); 2418 if (!h.raw) 2419 goto drop_n_account; 2420 2421 if (po->tp_version <= TPACKET_V2) { 2422 slot_id = po->rx_ring.head; 2423 if (test_bit(slot_id, po->rx_ring.rx_owner_map)) 2424 goto drop_n_account; 2425 __set_bit(slot_id, po->rx_ring.rx_owner_map); 2426 } 2427 2428 if (vnet_hdr_sz && 2429 virtio_net_hdr_from_skb(skb, h.raw + macoff - 2430 sizeof(struct virtio_net_hdr), 2431 vio_le(), true, 0)) { 2432 if (po->tp_version == TPACKET_V3) 2433 prb_clear_blk_fill_status(&po->rx_ring); 2434 goto drop_n_account; 2435 } 2436 2437 if (po->tp_version <= TPACKET_V2) { 2438 packet_increment_rx_head(po, &po->rx_ring); 2439 /* 2440 * LOSING will be reported till you read the stats, 2441 * because it's COR - Clear On Read. 2442 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2443 * at packet level. 2444 */ 2445 if (atomic_read(&po->tp_drops)) 2446 status |= TP_STATUS_LOSING; 2447 } 2448 2449 po->stats.stats1.tp_packets++; 2450 if (copy_skb) { 2451 status |= TP_STATUS_COPY; 2452 skb_clear_delivery_time(copy_skb); 2453 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2454 } 2455 spin_unlock(&sk->sk_receive_queue.lock); 2456 2457 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2458 2459 /* Always timestamp; prefer an existing software timestamp taken 2460 * closer to the time of capture. 2461 */ 2462 ts_status = tpacket_get_timestamp(skb, &ts, 2463 READ_ONCE(po->tp_tstamp) | 2464 SOF_TIMESTAMPING_SOFTWARE); 2465 if (!ts_status) 2466 ktime_get_real_ts64(&ts); 2467 2468 status |= ts_status; 2469 2470 switch (po->tp_version) { 2471 case TPACKET_V1: 2472 h.h1->tp_len = skb->len; 2473 h.h1->tp_snaplen = snaplen; 2474 h.h1->tp_mac = macoff; 2475 h.h1->tp_net = netoff; 2476 h.h1->tp_sec = ts.tv_sec; 2477 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2478 hdrlen = sizeof(*h.h1); 2479 break; 2480 case TPACKET_V2: 2481 h.h2->tp_len = skb->len; 2482 h.h2->tp_snaplen = snaplen; 2483 h.h2->tp_mac = macoff; 2484 h.h2->tp_net = netoff; 2485 h.h2->tp_sec = ts.tv_sec; 2486 h.h2->tp_nsec = ts.tv_nsec; 2487 if (skb_vlan_tag_present(skb)) { 2488 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2489 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2490 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2491 } else if (unlikely(sk->sk_type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 2492 h.h2->tp_vlan_tci = vlan_get_tci(skb, skb->dev); 2493 h.h2->tp_vlan_tpid = ntohs(skb->protocol); 2494 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2495 } else { 2496 h.h2->tp_vlan_tci = 0; 2497 h.h2->tp_vlan_tpid = 0; 2498 } 2499 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2500 hdrlen = sizeof(*h.h2); 2501 break; 2502 case TPACKET_V3: 2503 /* tp_nxt_offset,vlan are already populated above. 2504 * So DONT clear those fields here 2505 */ 2506 h.h3->tp_status |= status; 2507 h.h3->tp_len = skb->len; 2508 h.h3->tp_snaplen = snaplen; 2509 h.h3->tp_mac = macoff; 2510 h.h3->tp_net = netoff; 2511 h.h3->tp_sec = ts.tv_sec; 2512 h.h3->tp_nsec = ts.tv_nsec; 2513 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2514 hdrlen = sizeof(*h.h3); 2515 break; 2516 default: 2517 BUG(); 2518 } 2519 2520 sll = h.raw + TPACKET_ALIGN(hdrlen); 2521 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2522 sll->sll_family = AF_PACKET; 2523 sll->sll_hatype = dev->type; 2524 sll->sll_protocol = (sk->sk_type == SOCK_DGRAM) ? 2525 vlan_get_protocol_dgram(skb) : skb->protocol; 2526 sll->sll_pkttype = skb->pkt_type; 2527 if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) 2528 sll->sll_ifindex = orig_dev->ifindex; 2529 else 2530 sll->sll_ifindex = dev->ifindex; 2531 2532 smp_mb(); 2533 2534 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2535 if (po->tp_version <= TPACKET_V2) { 2536 u8 *start, *end; 2537 2538 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2539 macoff + snaplen); 2540 2541 for (start = h.raw; start < end; start += PAGE_SIZE) 2542 flush_dcache_page(pgv_to_page(start)); 2543 } 2544 smp_wmb(); 2545 #endif 2546 2547 if (po->tp_version <= TPACKET_V2) { 2548 spin_lock(&sk->sk_receive_queue.lock); 2549 __packet_set_status(po, h.raw, status); 2550 __clear_bit(slot_id, po->rx_ring.rx_owner_map); 2551 spin_unlock(&sk->sk_receive_queue.lock); 2552 sk->sk_data_ready(sk); 2553 } else if (po->tp_version == TPACKET_V3) { 2554 prb_clear_blk_fill_status(&po->rx_ring); 2555 } 2556 2557 drop_n_restore: 2558 if (skb_head != skb->data && skb_shared(skb)) { 2559 skb->data = skb_head; 2560 skb->len = skb_len; 2561 } 2562 drop: 2563 sk_skb_reason_drop(sk, skb, drop_reason); 2564 return 0; 2565 2566 drop_n_account: 2567 spin_unlock(&sk->sk_receive_queue.lock); 2568 atomic_inc(&po->tp_drops); 2569 drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; 2570 2571 sk->sk_data_ready(sk); 2572 sk_skb_reason_drop(sk, copy_skb, drop_reason); 2573 goto drop_n_restore; 2574 } 2575 2576 static void tpacket_destruct_skb(struct sk_buff *skb) 2577 { 2578 struct packet_sock *po = pkt_sk(skb->sk); 2579 2580 if (likely(po->tx_ring.pg_vec)) { 2581 void *ph; 2582 __u32 ts; 2583 2584 ph = skb_zcopy_get_nouarg(skb); 2585 packet_dec_pending(&po->tx_ring); 2586 2587 ts = __packet_set_timestamp(po, ph, skb); 2588 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2589 2590 complete(&po->skb_completion); 2591 } 2592 2593 sock_wfree(skb); 2594 } 2595 2596 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2597 { 2598 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2599 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2600 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2601 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2602 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2603 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2604 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2605 2606 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2607 return -EINVAL; 2608 2609 return 0; 2610 } 2611 2612 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2613 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) 2614 { 2615 int ret; 2616 2617 if (*len < vnet_hdr_sz) 2618 return -EINVAL; 2619 *len -= vnet_hdr_sz; 2620 2621 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2622 return -EFAULT; 2623 2624 ret = __packet_snd_vnet_parse(vnet_hdr, *len); 2625 if (ret) 2626 return ret; 2627 2628 /* move iter to point to the start of mac header */ 2629 if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) 2630 iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); 2631 2632 return 0; 2633 } 2634 2635 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2636 void *frame, struct net_device *dev, void *data, int tp_len, 2637 __be16 proto, unsigned char *addr, int hlen, int copylen, 2638 const struct sockcm_cookie *sockc) 2639 { 2640 union tpacket_uhdr ph; 2641 int to_write, offset, len, nr_frags, len_max; 2642 struct socket *sock = po->sk.sk_socket; 2643 struct page *page; 2644 int err; 2645 2646 ph.raw = frame; 2647 2648 skb->protocol = proto; 2649 skb->dev = dev; 2650 skb->priority = READ_ONCE(po->sk.sk_priority); 2651 skb->mark = READ_ONCE(po->sk.sk_mark); 2652 skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); 2653 skb_setup_tx_timestamp(skb, sockc->tsflags); 2654 skb_zcopy_set_nouarg(skb, ph.raw); 2655 2656 skb_reserve(skb, hlen); 2657 skb_reset_network_header(skb); 2658 2659 to_write = tp_len; 2660 2661 if (sock->type == SOCK_DGRAM) { 2662 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2663 NULL, tp_len); 2664 if (unlikely(err < 0)) 2665 return -EINVAL; 2666 } else if (copylen) { 2667 int hdrlen = min_t(int, copylen, tp_len); 2668 2669 skb_push(skb, dev->hard_header_len); 2670 skb_put(skb, copylen - dev->hard_header_len); 2671 err = skb_store_bits(skb, 0, data, hdrlen); 2672 if (unlikely(err)) 2673 return err; 2674 if (!dev_validate_header(dev, skb->data, hdrlen)) 2675 return -EINVAL; 2676 2677 data += hdrlen; 2678 to_write -= hdrlen; 2679 } 2680 2681 offset = offset_in_page(data); 2682 len_max = PAGE_SIZE - offset; 2683 len = ((to_write > len_max) ? len_max : to_write); 2684 2685 skb->data_len = to_write; 2686 skb->len += to_write; 2687 skb->truesize += to_write; 2688 refcount_add(to_write, &po->sk.sk_wmem_alloc); 2689 2690 while (likely(to_write)) { 2691 nr_frags = skb_shinfo(skb)->nr_frags; 2692 2693 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2694 pr_err("Packet exceed the number of skb frags(%u)\n", 2695 (unsigned int)MAX_SKB_FRAGS); 2696 return -EFAULT; 2697 } 2698 2699 page = pgv_to_page(data); 2700 data += len; 2701 flush_dcache_page(page); 2702 get_page(page); 2703 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2704 to_write -= len; 2705 offset = 0; 2706 len_max = PAGE_SIZE; 2707 len = ((to_write > len_max) ? len_max : to_write); 2708 } 2709 2710 packet_parse_headers(skb, sock); 2711 2712 return tp_len; 2713 } 2714 2715 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2716 int size_max, void **data) 2717 { 2718 union tpacket_uhdr ph; 2719 int tp_len, off; 2720 2721 ph.raw = frame; 2722 2723 switch (po->tp_version) { 2724 case TPACKET_V3: 2725 if (ph.h3->tp_next_offset != 0) { 2726 pr_warn_once("variable sized slot not supported"); 2727 return -EINVAL; 2728 } 2729 tp_len = ph.h3->tp_len; 2730 break; 2731 case TPACKET_V2: 2732 tp_len = ph.h2->tp_len; 2733 break; 2734 default: 2735 tp_len = ph.h1->tp_len; 2736 break; 2737 } 2738 if (unlikely(tp_len > size_max)) { 2739 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2740 return -EMSGSIZE; 2741 } 2742 2743 if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { 2744 int off_min, off_max; 2745 2746 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2747 off_max = po->tx_ring.frame_size - tp_len; 2748 if (po->sk.sk_type == SOCK_DGRAM) { 2749 switch (po->tp_version) { 2750 case TPACKET_V3: 2751 off = ph.h3->tp_net; 2752 break; 2753 case TPACKET_V2: 2754 off = ph.h2->tp_net; 2755 break; 2756 default: 2757 off = ph.h1->tp_net; 2758 break; 2759 } 2760 } else { 2761 switch (po->tp_version) { 2762 case TPACKET_V3: 2763 off = ph.h3->tp_mac; 2764 break; 2765 case TPACKET_V2: 2766 off = ph.h2->tp_mac; 2767 break; 2768 default: 2769 off = ph.h1->tp_mac; 2770 break; 2771 } 2772 } 2773 if (unlikely((off < off_min) || (off_max < off))) 2774 return -EINVAL; 2775 } else { 2776 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2777 } 2778 2779 *data = frame + off; 2780 return tp_len; 2781 } 2782 2783 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2784 { 2785 struct sk_buff *skb = NULL; 2786 struct net_device *dev; 2787 struct virtio_net_hdr *vnet_hdr = NULL; 2788 struct sockcm_cookie sockc; 2789 __be16 proto; 2790 int err, reserve = 0; 2791 void *ph; 2792 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2793 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2794 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 2795 unsigned char *addr = NULL; 2796 int tp_len, size_max; 2797 void *data; 2798 int len_sum = 0; 2799 int status = TP_STATUS_AVAILABLE; 2800 int hlen, tlen, copylen = 0; 2801 long timeo = 0; 2802 2803 mutex_lock(&po->pg_vec_lock); 2804 2805 /* packet_sendmsg() check on tx_ring.pg_vec was lockless, 2806 * we need to confirm it under protection of pg_vec_lock. 2807 */ 2808 if (unlikely(!po->tx_ring.pg_vec)) { 2809 err = -EBUSY; 2810 goto out; 2811 } 2812 if (likely(saddr == NULL)) { 2813 dev = packet_cached_dev_get(po); 2814 proto = READ_ONCE(po->num); 2815 } else { 2816 err = -EINVAL; 2817 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2818 goto out; 2819 if (msg->msg_namelen < (saddr->sll_halen 2820 + offsetof(struct sockaddr_ll, 2821 sll_addr))) 2822 goto out; 2823 proto = saddr->sll_protocol; 2824 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2825 if (po->sk.sk_socket->type == SOCK_DGRAM) { 2826 if (dev && msg->msg_namelen < dev->addr_len + 2827 offsetof(struct sockaddr_ll, sll_addr)) 2828 goto out_put; 2829 addr = saddr->sll_addr; 2830 } 2831 } 2832 2833 err = -ENXIO; 2834 if (unlikely(dev == NULL)) 2835 goto out; 2836 err = -ENETDOWN; 2837 if (unlikely(!(dev->flags & IFF_UP))) 2838 goto out_put; 2839 2840 sockcm_init(&sockc, &po->sk); 2841 if (msg->msg_controllen) { 2842 err = sock_cmsg_send(&po->sk, msg, &sockc); 2843 if (unlikely(err)) 2844 goto out_put; 2845 } 2846 2847 if (po->sk.sk_socket->type == SOCK_RAW) 2848 reserve = dev->hard_header_len; 2849 size_max = po->tx_ring.frame_size 2850 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2851 2852 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) 2853 size_max = dev->mtu + reserve + VLAN_HLEN; 2854 2855 reinit_completion(&po->skb_completion); 2856 2857 do { 2858 ph = packet_current_frame(po, &po->tx_ring, 2859 TP_STATUS_SEND_REQUEST); 2860 if (unlikely(ph == NULL)) { 2861 if (need_wait && skb) { 2862 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); 2863 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); 2864 if (timeo <= 0) { 2865 err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; 2866 goto out_put; 2867 } 2868 } 2869 /* check for additional frames */ 2870 continue; 2871 } 2872 2873 skb = NULL; 2874 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2875 if (tp_len < 0) 2876 goto tpacket_error; 2877 2878 status = TP_STATUS_SEND_REQUEST; 2879 hlen = LL_RESERVED_SPACE(dev); 2880 tlen = dev->needed_tailroom; 2881 if (vnet_hdr_sz) { 2882 vnet_hdr = data; 2883 data += vnet_hdr_sz; 2884 tp_len -= vnet_hdr_sz; 2885 if (tp_len < 0 || 2886 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2887 tp_len = -EINVAL; 2888 goto tpacket_error; 2889 } 2890 copylen = __virtio16_to_cpu(vio_le(), 2891 vnet_hdr->hdr_len); 2892 } 2893 copylen = max_t(int, copylen, dev->hard_header_len); 2894 skb = sock_alloc_send_skb(&po->sk, 2895 hlen + tlen + sizeof(struct sockaddr_ll) + 2896 (copylen - dev->hard_header_len), 2897 !need_wait, &err); 2898 2899 if (unlikely(skb == NULL)) { 2900 /* we assume the socket was initially writeable ... */ 2901 if (likely(len_sum > 0)) 2902 err = len_sum; 2903 goto out_status; 2904 } 2905 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2906 addr, hlen, copylen, &sockc); 2907 if (likely(tp_len >= 0) && 2908 tp_len > dev->mtu + reserve && 2909 !vnet_hdr_sz && 2910 !packet_extra_vlan_len_allowed(dev, skb)) 2911 tp_len = -EMSGSIZE; 2912 2913 if (unlikely(tp_len < 0)) { 2914 tpacket_error: 2915 if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { 2916 __packet_set_status(po, ph, 2917 TP_STATUS_AVAILABLE); 2918 packet_increment_head(&po->tx_ring); 2919 kfree_skb(skb); 2920 continue; 2921 } else { 2922 status = TP_STATUS_WRONG_FORMAT; 2923 err = tp_len; 2924 goto out_status; 2925 } 2926 } 2927 2928 if (vnet_hdr_sz) { 2929 if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { 2930 tp_len = -EINVAL; 2931 goto tpacket_error; 2932 } 2933 virtio_net_hdr_set_proto(skb, vnet_hdr); 2934 } 2935 2936 skb->destructor = tpacket_destruct_skb; 2937 __packet_set_status(po, ph, TP_STATUS_SENDING); 2938 packet_inc_pending(&po->tx_ring); 2939 2940 status = TP_STATUS_SEND_REQUEST; 2941 err = packet_xmit(po, skb); 2942 if (unlikely(err != 0)) { 2943 if (err > 0) 2944 err = net_xmit_errno(err); 2945 if (err && __packet_get_status(po, ph) == 2946 TP_STATUS_AVAILABLE) { 2947 /* skb was destructed already */ 2948 skb = NULL; 2949 goto out_status; 2950 } 2951 /* 2952 * skb was dropped but not destructed yet; 2953 * let's treat it like congestion or err < 0 2954 */ 2955 err = 0; 2956 } 2957 packet_increment_head(&po->tx_ring); 2958 len_sum += tp_len; 2959 } while (likely((ph != NULL) || 2960 /* Note: packet_read_pending() might be slow if we have 2961 * to call it as it's per_cpu variable, but in fast-path 2962 * we already short-circuit the loop with the first 2963 * condition, and luckily don't have to go that path 2964 * anyway. 2965 */ 2966 (need_wait && packet_read_pending(&po->tx_ring)))); 2967 2968 err = len_sum; 2969 goto out_put; 2970 2971 out_status: 2972 __packet_set_status(po, ph, status); 2973 kfree_skb(skb); 2974 out_put: 2975 dev_put(dev); 2976 out: 2977 mutex_unlock(&po->pg_vec_lock); 2978 return err; 2979 } 2980 2981 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2982 size_t reserve, size_t len, 2983 size_t linear, int noblock, 2984 int *err) 2985 { 2986 struct sk_buff *skb; 2987 2988 /* Under a page? Don't bother with paged skb. */ 2989 if (prepad + len < PAGE_SIZE || !linear) 2990 linear = len; 2991 2992 if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) 2993 linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); 2994 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2995 err, PAGE_ALLOC_COSTLY_ORDER); 2996 if (!skb) 2997 return NULL; 2998 2999 skb_reserve(skb, reserve); 3000 skb_put(skb, linear); 3001 skb->data_len = len - linear; 3002 skb->len += len - linear; 3003 3004 return skb; 3005 } 3006 3007 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 3008 { 3009 struct sock *sk = sock->sk; 3010 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 3011 struct sk_buff *skb; 3012 struct net_device *dev; 3013 __be16 proto; 3014 unsigned char *addr = NULL; 3015 int err, reserve = 0; 3016 struct sockcm_cookie sockc; 3017 struct virtio_net_hdr vnet_hdr = { 0 }; 3018 int offset = 0; 3019 struct packet_sock *po = pkt_sk(sk); 3020 int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); 3021 int hlen, tlen, linear; 3022 int extra_len = 0; 3023 3024 /* 3025 * Get and verify the address. 3026 */ 3027 3028 if (likely(saddr == NULL)) { 3029 dev = packet_cached_dev_get(po); 3030 proto = READ_ONCE(po->num); 3031 } else { 3032 err = -EINVAL; 3033 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 3034 goto out; 3035 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 3036 goto out; 3037 proto = saddr->sll_protocol; 3038 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 3039 if (sock->type == SOCK_DGRAM) { 3040 if (dev && msg->msg_namelen < dev->addr_len + 3041 offsetof(struct sockaddr_ll, sll_addr)) 3042 goto out_unlock; 3043 addr = saddr->sll_addr; 3044 } 3045 } 3046 3047 err = -ENXIO; 3048 if (unlikely(dev == NULL)) 3049 goto out_unlock; 3050 err = -ENETDOWN; 3051 if (unlikely(!(dev->flags & IFF_UP))) 3052 goto out_unlock; 3053 3054 sockcm_init(&sockc, sk); 3055 sockc.mark = READ_ONCE(sk->sk_mark); 3056 if (msg->msg_controllen) { 3057 err = sock_cmsg_send(sk, msg, &sockc); 3058 if (unlikely(err)) 3059 goto out_unlock; 3060 } 3061 3062 if (sock->type == SOCK_RAW) 3063 reserve = dev->hard_header_len; 3064 if (vnet_hdr_sz) { 3065 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); 3066 if (err) 3067 goto out_unlock; 3068 } 3069 3070 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 3071 if (!netif_supports_nofcs(dev)) { 3072 err = -EPROTONOSUPPORT; 3073 goto out_unlock; 3074 } 3075 extra_len = 4; /* We're doing our own CRC */ 3076 } 3077 3078 err = -EMSGSIZE; 3079 if (!vnet_hdr.gso_type && 3080 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 3081 goto out_unlock; 3082 3083 err = -ENOBUFS; 3084 hlen = LL_RESERVED_SPACE(dev); 3085 tlen = dev->needed_tailroom; 3086 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 3087 linear = max(linear, min_t(int, len, dev->hard_header_len)); 3088 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 3089 msg->msg_flags & MSG_DONTWAIT, &err); 3090 if (skb == NULL) 3091 goto out_unlock; 3092 3093 skb_reset_network_header(skb); 3094 3095 err = -EINVAL; 3096 if (sock->type == SOCK_DGRAM) { 3097 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 3098 if (unlikely(offset < 0)) 3099 goto out_free; 3100 } else if (reserve) { 3101 skb_reserve(skb, -reserve); 3102 if (len < reserve + sizeof(struct ipv6hdr) && 3103 dev->min_header_len != dev->hard_header_len) 3104 skb_reset_network_header(skb); 3105 } 3106 3107 /* Returns -EFAULT on error */ 3108 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 3109 if (err) 3110 goto out_free; 3111 3112 if ((sock->type == SOCK_RAW && 3113 !dev_validate_header(dev, skb->data, len)) || !skb->len) { 3114 err = -EINVAL; 3115 goto out_free; 3116 } 3117 3118 skb_setup_tx_timestamp(skb, sockc.tsflags); 3119 3120 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 3121 !packet_extra_vlan_len_allowed(dev, skb)) { 3122 err = -EMSGSIZE; 3123 goto out_free; 3124 } 3125 3126 skb->protocol = proto; 3127 skb->dev = dev; 3128 skb->priority = READ_ONCE(sk->sk_priority); 3129 skb->mark = sockc.mark; 3130 skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); 3131 3132 if (unlikely(extra_len == 4)) 3133 skb->no_fcs = 1; 3134 3135 packet_parse_headers(skb, sock); 3136 3137 if (vnet_hdr_sz) { 3138 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 3139 if (err) 3140 goto out_free; 3141 len += vnet_hdr_sz; 3142 virtio_net_hdr_set_proto(skb, &vnet_hdr); 3143 } 3144 3145 err = packet_xmit(po, skb); 3146 3147 if (unlikely(err != 0)) { 3148 if (err > 0) 3149 err = net_xmit_errno(err); 3150 if (err) 3151 goto out_unlock; 3152 } 3153 3154 dev_put(dev); 3155 3156 return len; 3157 3158 out_free: 3159 kfree_skb(skb); 3160 out_unlock: 3161 dev_put(dev); 3162 out: 3163 return err; 3164 } 3165 3166 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 3167 { 3168 struct sock *sk = sock->sk; 3169 struct packet_sock *po = pkt_sk(sk); 3170 3171 /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. 3172 * tpacket_snd() will redo the check safely. 3173 */ 3174 if (data_race(po->tx_ring.pg_vec)) 3175 return tpacket_snd(po, msg); 3176 3177 return packet_snd(sock, msg, len); 3178 } 3179 3180 /* 3181 * Close a PACKET socket. This is fairly simple. We immediately go 3182 * to 'closed' state and remove our protocol entry in the device list. 3183 */ 3184 3185 static int packet_release(struct socket *sock) 3186 { 3187 struct sock *sk = sock->sk; 3188 struct packet_sock *po; 3189 struct packet_fanout *f; 3190 struct net *net; 3191 union tpacket_req_u req_u; 3192 3193 if (!sk) 3194 return 0; 3195 3196 net = sock_net(sk); 3197 po = pkt_sk(sk); 3198 3199 mutex_lock(&net->packet.sklist_lock); 3200 sk_del_node_init_rcu(sk); 3201 mutex_unlock(&net->packet.sklist_lock); 3202 3203 sock_prot_inuse_add(net, sk->sk_prot, -1); 3204 3205 spin_lock(&po->bind_lock); 3206 unregister_prot_hook(sk, false); 3207 packet_cached_dev_reset(po); 3208 3209 if (po->prot_hook.dev) { 3210 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3211 po->prot_hook.dev = NULL; 3212 } 3213 spin_unlock(&po->bind_lock); 3214 3215 packet_flush_mclist(sk); 3216 3217 lock_sock(sk); 3218 if (po->rx_ring.pg_vec) { 3219 memset(&req_u, 0, sizeof(req_u)); 3220 packet_set_ring(sk, &req_u, 1, 0); 3221 } 3222 3223 if (po->tx_ring.pg_vec) { 3224 memset(&req_u, 0, sizeof(req_u)); 3225 packet_set_ring(sk, &req_u, 1, 1); 3226 } 3227 release_sock(sk); 3228 3229 f = fanout_release(sk); 3230 3231 synchronize_net(); 3232 3233 kfree(po->rollover); 3234 if (f) { 3235 fanout_release_data(f); 3236 kvfree(f); 3237 } 3238 /* 3239 * Now the socket is dead. No more input will appear. 3240 */ 3241 sock_orphan(sk); 3242 sock->sk = NULL; 3243 3244 /* Purge queues */ 3245 3246 skb_queue_purge(&sk->sk_receive_queue); 3247 packet_free_pending(po); 3248 3249 sock_put(sk); 3250 return 0; 3251 } 3252 3253 /* 3254 * Attach a packet hook. 3255 */ 3256 3257 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3258 __be16 proto) 3259 { 3260 struct packet_sock *po = pkt_sk(sk); 3261 struct net_device *dev = NULL; 3262 bool unlisted = false; 3263 bool need_rehook; 3264 int ret = 0; 3265 3266 lock_sock(sk); 3267 spin_lock(&po->bind_lock); 3268 if (!proto) 3269 proto = po->num; 3270 3271 rcu_read_lock(); 3272 3273 if (po->fanout) { 3274 ret = -EINVAL; 3275 goto out_unlock; 3276 } 3277 3278 if (name) { 3279 dev = dev_get_by_name_rcu(sock_net(sk), name); 3280 if (!dev) { 3281 ret = -ENODEV; 3282 goto out_unlock; 3283 } 3284 } else if (ifindex) { 3285 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3286 if (!dev) { 3287 ret = -ENODEV; 3288 goto out_unlock; 3289 } 3290 } 3291 3292 need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; 3293 3294 if (need_rehook) { 3295 dev_hold(dev); 3296 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 3297 rcu_read_unlock(); 3298 /* prevents packet_notifier() from calling 3299 * register_prot_hook() 3300 */ 3301 WRITE_ONCE(po->num, 0); 3302 __unregister_prot_hook(sk, true); 3303 rcu_read_lock(); 3304 if (dev) 3305 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3306 dev->ifindex); 3307 } 3308 3309 BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); 3310 WRITE_ONCE(po->num, proto); 3311 po->prot_hook.type = proto; 3312 3313 netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); 3314 3315 if (unlikely(unlisted)) { 3316 po->prot_hook.dev = NULL; 3317 WRITE_ONCE(po->ifindex, -1); 3318 packet_cached_dev_reset(po); 3319 } else { 3320 netdev_hold(dev, &po->prot_hook.dev_tracker, 3321 GFP_ATOMIC); 3322 po->prot_hook.dev = dev; 3323 WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); 3324 packet_cached_dev_assign(po, dev); 3325 } 3326 dev_put(dev); 3327 } 3328 3329 if (proto == 0 || !need_rehook) 3330 goto out_unlock; 3331 3332 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3333 register_prot_hook(sk); 3334 } else { 3335 sk->sk_err = ENETDOWN; 3336 if (!sock_flag(sk, SOCK_DEAD)) 3337 sk_error_report(sk); 3338 } 3339 3340 out_unlock: 3341 rcu_read_unlock(); 3342 spin_unlock(&po->bind_lock); 3343 release_sock(sk); 3344 return ret; 3345 } 3346 3347 /* 3348 * Bind a packet socket to a device 3349 */ 3350 3351 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3352 int addr_len) 3353 { 3354 struct sock *sk = sock->sk; 3355 char name[sizeof(uaddr->sa_data_min) + 1]; 3356 3357 /* 3358 * Check legality 3359 */ 3360 3361 if (addr_len != sizeof(struct sockaddr)) 3362 return -EINVAL; 3363 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3364 * zero-terminated. 3365 */ 3366 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min)); 3367 name[sizeof(uaddr->sa_data_min)] = 0; 3368 3369 return packet_do_bind(sk, name, 0, 0); 3370 } 3371 3372 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3373 { 3374 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3375 struct sock *sk = sock->sk; 3376 3377 /* 3378 * Check legality 3379 */ 3380 3381 if (addr_len < sizeof(struct sockaddr_ll)) 3382 return -EINVAL; 3383 if (sll->sll_family != AF_PACKET) 3384 return -EINVAL; 3385 3386 return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); 3387 } 3388 3389 static struct proto packet_proto = { 3390 .name = "PACKET", 3391 .owner = THIS_MODULE, 3392 .obj_size = sizeof(struct packet_sock), 3393 }; 3394 3395 /* 3396 * Create a packet of type SOCK_PACKET. 3397 */ 3398 3399 static int packet_create(struct net *net, struct socket *sock, int protocol, 3400 int kern) 3401 { 3402 struct sock *sk; 3403 struct packet_sock *po; 3404 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3405 int err; 3406 3407 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3408 return -EPERM; 3409 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3410 sock->type != SOCK_PACKET) 3411 return -ESOCKTNOSUPPORT; 3412 3413 sock->state = SS_UNCONNECTED; 3414 3415 err = -ENOBUFS; 3416 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3417 if (sk == NULL) 3418 goto out; 3419 3420 sock->ops = &packet_ops; 3421 if (sock->type == SOCK_PACKET) 3422 sock->ops = &packet_ops_spkt; 3423 3424 sock_init_data(sock, sk); 3425 3426 po = pkt_sk(sk); 3427 init_completion(&po->skb_completion); 3428 sk->sk_family = PF_PACKET; 3429 po->num = proto; 3430 3431 err = packet_alloc_pending(po); 3432 if (err) 3433 goto out2; 3434 3435 packet_cached_dev_reset(po); 3436 3437 sk->sk_destruct = packet_sock_destruct; 3438 3439 /* 3440 * Attach a protocol block 3441 */ 3442 3443 spin_lock_init(&po->bind_lock); 3444 mutex_init(&po->pg_vec_lock); 3445 po->rollover = NULL; 3446 po->prot_hook.func = packet_rcv; 3447 3448 if (sock->type == SOCK_PACKET) 3449 po->prot_hook.func = packet_rcv_spkt; 3450 3451 po->prot_hook.af_packet_priv = sk; 3452 po->prot_hook.af_packet_net = sock_net(sk); 3453 3454 if (proto) { 3455 po->prot_hook.type = proto; 3456 __register_prot_hook(sk); 3457 } 3458 3459 mutex_lock(&net->packet.sklist_lock); 3460 sk_add_node_tail_rcu(sk, &net->packet.sklist); 3461 mutex_unlock(&net->packet.sklist_lock); 3462 3463 sock_prot_inuse_add(net, &packet_proto, 1); 3464 3465 return 0; 3466 out2: 3467 sk_free(sk); 3468 out: 3469 return err; 3470 } 3471 3472 /* 3473 * Pull a packet from our receive queue and hand it to the user. 3474 * If necessary we block. 3475 */ 3476 3477 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3478 int flags) 3479 { 3480 struct sock *sk = sock->sk; 3481 struct sk_buff *skb; 3482 int copied, err; 3483 int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); 3484 unsigned int origlen = 0; 3485 3486 err = -EINVAL; 3487 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3488 goto out; 3489 3490 #if 0 3491 /* What error should we return now? EUNATTACH? */ 3492 if (pkt_sk(sk)->ifindex < 0) 3493 return -ENODEV; 3494 #endif 3495 3496 if (flags & MSG_ERRQUEUE) { 3497 err = sock_recv_errqueue(sk, msg, len, 3498 SOL_PACKET, PACKET_TX_TIMESTAMP); 3499 goto out; 3500 } 3501 3502 /* 3503 * Call the generic datagram receiver. This handles all sorts 3504 * of horrible races and re-entrancy so we can forget about it 3505 * in the protocol layers. 3506 * 3507 * Now it will return ENETDOWN, if device have just gone down, 3508 * but then it will block. 3509 */ 3510 3511 skb = skb_recv_datagram(sk, flags, &err); 3512 3513 /* 3514 * An error occurred so return it. Because skb_recv_datagram() 3515 * handles the blocking we don't see and worry about blocking 3516 * retries. 3517 */ 3518 3519 if (skb == NULL) 3520 goto out; 3521 3522 packet_rcv_try_clear_pressure(pkt_sk(sk)); 3523 3524 if (vnet_hdr_len) { 3525 err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); 3526 if (err) 3527 goto out_free; 3528 } 3529 3530 /* You lose any data beyond the buffer you gave. If it worries 3531 * a user program they can ask the device for its MTU 3532 * anyway. 3533 */ 3534 copied = skb->len; 3535 if (copied > len) { 3536 copied = len; 3537 msg->msg_flags |= MSG_TRUNC; 3538 } 3539 3540 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3541 if (err) 3542 goto out_free; 3543 3544 if (sock->type != SOCK_PACKET) { 3545 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3546 3547 /* Original length was stored in sockaddr_ll fields */ 3548 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3549 sll->sll_family = AF_PACKET; 3550 sll->sll_protocol = (sock->type == SOCK_DGRAM) ? 3551 vlan_get_protocol_dgram(skb) : skb->protocol; 3552 } 3553 3554 sock_recv_cmsgs(msg, sk, skb); 3555 3556 if (msg->msg_name) { 3557 const size_t max_len = min(sizeof(skb->cb), 3558 sizeof(struct sockaddr_storage)); 3559 int copy_len; 3560 3561 /* If the address length field is there to be filled 3562 * in, we fill it in now. 3563 */ 3564 if (sock->type == SOCK_PACKET) { 3565 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3566 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3567 copy_len = msg->msg_namelen; 3568 } else { 3569 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3570 3571 msg->msg_namelen = sll->sll_halen + 3572 offsetof(struct sockaddr_ll, sll_addr); 3573 copy_len = msg->msg_namelen; 3574 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { 3575 memset(msg->msg_name + 3576 offsetof(struct sockaddr_ll, sll_addr), 3577 0, sizeof(sll->sll_addr)); 3578 msg->msg_namelen = sizeof(struct sockaddr_ll); 3579 } 3580 } 3581 if (WARN_ON_ONCE(copy_len > max_len)) { 3582 copy_len = max_len; 3583 msg->msg_namelen = copy_len; 3584 } 3585 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); 3586 } 3587 3588 if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { 3589 struct tpacket_auxdata aux; 3590 3591 aux.tp_status = TP_STATUS_USER; 3592 if (skb->ip_summed == CHECKSUM_PARTIAL) 3593 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3594 else if (skb->pkt_type != PACKET_OUTGOING && 3595 skb_csum_unnecessary(skb)) 3596 aux.tp_status |= TP_STATUS_CSUM_VALID; 3597 if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) 3598 aux.tp_status |= TP_STATUS_GSO_TCP; 3599 3600 aux.tp_len = origlen; 3601 aux.tp_snaplen = skb->len; 3602 aux.tp_mac = 0; 3603 aux.tp_net = skb_network_offset(skb); 3604 if (skb_vlan_tag_present(skb)) { 3605 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3606 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3607 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3608 } else if (unlikely(sock->type == SOCK_DGRAM && eth_type_vlan(skb->protocol))) { 3609 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3610 struct net_device *dev; 3611 3612 rcu_read_lock(); 3613 dev = dev_get_by_index_rcu(sock_net(sk), sll->sll_ifindex); 3614 if (dev) { 3615 aux.tp_vlan_tci = vlan_get_tci(skb, dev); 3616 aux.tp_vlan_tpid = ntohs(skb->protocol); 3617 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3618 } else { 3619 aux.tp_vlan_tci = 0; 3620 aux.tp_vlan_tpid = 0; 3621 } 3622 rcu_read_unlock(); 3623 } else { 3624 aux.tp_vlan_tci = 0; 3625 aux.tp_vlan_tpid = 0; 3626 } 3627 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3628 } 3629 3630 /* 3631 * Free or return the buffer as appropriate. Again this 3632 * hides all the races and re-entrancy issues from us. 3633 */ 3634 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3635 3636 out_free: 3637 skb_free_datagram(sk, skb); 3638 out: 3639 return err; 3640 } 3641 3642 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3643 int peer) 3644 { 3645 struct net_device *dev; 3646 struct sock *sk = sock->sk; 3647 3648 if (peer) 3649 return -EOPNOTSUPP; 3650 3651 uaddr->sa_family = AF_PACKET; 3652 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min)); 3653 rcu_read_lock(); 3654 dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); 3655 if (dev) 3656 strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min)); 3657 rcu_read_unlock(); 3658 3659 return sizeof(*uaddr); 3660 } 3661 3662 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3663 int peer) 3664 { 3665 struct net_device *dev; 3666 struct sock *sk = sock->sk; 3667 struct packet_sock *po = pkt_sk(sk); 3668 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3669 int ifindex; 3670 3671 if (peer) 3672 return -EOPNOTSUPP; 3673 3674 ifindex = READ_ONCE(po->ifindex); 3675 sll->sll_family = AF_PACKET; 3676 sll->sll_ifindex = ifindex; 3677 sll->sll_protocol = READ_ONCE(po->num); 3678 sll->sll_pkttype = 0; 3679 rcu_read_lock(); 3680 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3681 if (dev) { 3682 sll->sll_hatype = dev->type; 3683 sll->sll_halen = dev->addr_len; 3684 3685 /* Let __fortify_memcpy_chk() know the actual buffer size. */ 3686 memcpy(((struct sockaddr_storage *)sll)->__data + 3687 offsetof(struct sockaddr_ll, sll_addr) - 3688 offsetofend(struct sockaddr_ll, sll_family), 3689 dev->dev_addr, dev->addr_len); 3690 } else { 3691 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3692 sll->sll_halen = 0; 3693 } 3694 rcu_read_unlock(); 3695 3696 return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3697 } 3698 3699 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3700 int what) 3701 { 3702 switch (i->type) { 3703 case PACKET_MR_MULTICAST: 3704 if (i->alen != dev->addr_len) 3705 return -EINVAL; 3706 if (what > 0) 3707 return dev_mc_add(dev, i->addr); 3708 else 3709 return dev_mc_del(dev, i->addr); 3710 break; 3711 case PACKET_MR_PROMISC: 3712 return dev_set_promiscuity(dev, what); 3713 case PACKET_MR_ALLMULTI: 3714 return dev_set_allmulti(dev, what); 3715 case PACKET_MR_UNICAST: 3716 if (i->alen != dev->addr_len) 3717 return -EINVAL; 3718 if (what > 0) 3719 return dev_uc_add(dev, i->addr); 3720 else 3721 return dev_uc_del(dev, i->addr); 3722 break; 3723 default: 3724 break; 3725 } 3726 return 0; 3727 } 3728 3729 static void packet_dev_mclist_delete(struct net_device *dev, 3730 struct packet_mclist **mlp) 3731 { 3732 struct packet_mclist *ml; 3733 3734 while ((ml = *mlp) != NULL) { 3735 if (ml->ifindex == dev->ifindex) { 3736 packet_dev_mc(dev, ml, -1); 3737 *mlp = ml->next; 3738 kfree(ml); 3739 } else 3740 mlp = &ml->next; 3741 } 3742 } 3743 3744 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3745 { 3746 struct packet_sock *po = pkt_sk(sk); 3747 struct packet_mclist *ml, *i; 3748 struct net_device *dev; 3749 int err; 3750 3751 rtnl_lock(); 3752 3753 err = -ENODEV; 3754 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3755 if (!dev) 3756 goto done; 3757 3758 err = -EINVAL; 3759 if (mreq->mr_alen > dev->addr_len) 3760 goto done; 3761 3762 err = -ENOBUFS; 3763 i = kmalloc(sizeof(*i), GFP_KERNEL); 3764 if (i == NULL) 3765 goto done; 3766 3767 err = 0; 3768 for (ml = po->mclist; ml; ml = ml->next) { 3769 if (ml->ifindex == mreq->mr_ifindex && 3770 ml->type == mreq->mr_type && 3771 ml->alen == mreq->mr_alen && 3772 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3773 ml->count++; 3774 /* Free the new element ... */ 3775 kfree(i); 3776 goto done; 3777 } 3778 } 3779 3780 i->type = mreq->mr_type; 3781 i->ifindex = mreq->mr_ifindex; 3782 i->alen = mreq->mr_alen; 3783 memcpy(i->addr, mreq->mr_address, i->alen); 3784 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3785 i->count = 1; 3786 i->next = po->mclist; 3787 po->mclist = i; 3788 err = packet_dev_mc(dev, i, 1); 3789 if (err) { 3790 po->mclist = i->next; 3791 kfree(i); 3792 } 3793 3794 done: 3795 rtnl_unlock(); 3796 return err; 3797 } 3798 3799 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3800 { 3801 struct packet_mclist *ml, **mlp; 3802 3803 rtnl_lock(); 3804 3805 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3806 if (ml->ifindex == mreq->mr_ifindex && 3807 ml->type == mreq->mr_type && 3808 ml->alen == mreq->mr_alen && 3809 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3810 if (--ml->count == 0) { 3811 struct net_device *dev; 3812 *mlp = ml->next; 3813 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3814 if (dev) 3815 packet_dev_mc(dev, ml, -1); 3816 kfree(ml); 3817 } 3818 break; 3819 } 3820 } 3821 rtnl_unlock(); 3822 return 0; 3823 } 3824 3825 static void packet_flush_mclist(struct sock *sk) 3826 { 3827 struct packet_sock *po = pkt_sk(sk); 3828 struct packet_mclist *ml; 3829 3830 if (!po->mclist) 3831 return; 3832 3833 rtnl_lock(); 3834 while ((ml = po->mclist) != NULL) { 3835 struct net_device *dev; 3836 3837 po->mclist = ml->next; 3838 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3839 if (dev != NULL) 3840 packet_dev_mc(dev, ml, -1); 3841 kfree(ml); 3842 } 3843 rtnl_unlock(); 3844 } 3845 3846 static int 3847 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 3848 unsigned int optlen) 3849 { 3850 struct sock *sk = sock->sk; 3851 struct packet_sock *po = pkt_sk(sk); 3852 int ret; 3853 3854 if (level != SOL_PACKET) 3855 return -ENOPROTOOPT; 3856 3857 switch (optname) { 3858 case PACKET_ADD_MEMBERSHIP: 3859 case PACKET_DROP_MEMBERSHIP: 3860 { 3861 struct packet_mreq_max mreq; 3862 int len = optlen; 3863 memset(&mreq, 0, sizeof(mreq)); 3864 if (len < sizeof(struct packet_mreq)) 3865 return -EINVAL; 3866 if (len > sizeof(mreq)) 3867 len = sizeof(mreq); 3868 if (copy_from_sockptr(&mreq, optval, len)) 3869 return -EFAULT; 3870 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3871 return -EINVAL; 3872 if (optname == PACKET_ADD_MEMBERSHIP) 3873 ret = packet_mc_add(sk, &mreq); 3874 else 3875 ret = packet_mc_drop(sk, &mreq); 3876 return ret; 3877 } 3878 3879 case PACKET_RX_RING: 3880 case PACKET_TX_RING: 3881 { 3882 union tpacket_req_u req_u; 3883 3884 ret = -EINVAL; 3885 lock_sock(sk); 3886 switch (po->tp_version) { 3887 case TPACKET_V1: 3888 case TPACKET_V2: 3889 if (optlen < sizeof(req_u.req)) 3890 break; 3891 ret = copy_from_sockptr(&req_u.req, optval, 3892 sizeof(req_u.req)) ? 3893 -EINVAL : 0; 3894 break; 3895 case TPACKET_V3: 3896 default: 3897 if (optlen < sizeof(req_u.req3)) 3898 break; 3899 ret = copy_from_sockptr(&req_u.req3, optval, 3900 sizeof(req_u.req3)) ? 3901 -EINVAL : 0; 3902 break; 3903 } 3904 if (!ret) 3905 ret = packet_set_ring(sk, &req_u, 0, 3906 optname == PACKET_TX_RING); 3907 release_sock(sk); 3908 return ret; 3909 } 3910 case PACKET_COPY_THRESH: 3911 { 3912 int val; 3913 3914 if (optlen != sizeof(val)) 3915 return -EINVAL; 3916 if (copy_from_sockptr(&val, optval, sizeof(val))) 3917 return -EFAULT; 3918 3919 WRITE_ONCE(pkt_sk(sk)->copy_thresh, val); 3920 return 0; 3921 } 3922 case PACKET_VERSION: 3923 { 3924 int val; 3925 3926 if (optlen != sizeof(val)) 3927 return -EINVAL; 3928 if (copy_from_sockptr(&val, optval, sizeof(val))) 3929 return -EFAULT; 3930 switch (val) { 3931 case TPACKET_V1: 3932 case TPACKET_V2: 3933 case TPACKET_V3: 3934 break; 3935 default: 3936 return -EINVAL; 3937 } 3938 lock_sock(sk); 3939 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3940 ret = -EBUSY; 3941 } else { 3942 po->tp_version = val; 3943 ret = 0; 3944 } 3945 release_sock(sk); 3946 return ret; 3947 } 3948 case PACKET_RESERVE: 3949 { 3950 unsigned int val; 3951 3952 if (optlen != sizeof(val)) 3953 return -EINVAL; 3954 if (copy_from_sockptr(&val, optval, sizeof(val))) 3955 return -EFAULT; 3956 if (val > INT_MAX) 3957 return -EINVAL; 3958 lock_sock(sk); 3959 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3960 ret = -EBUSY; 3961 } else { 3962 po->tp_reserve = val; 3963 ret = 0; 3964 } 3965 release_sock(sk); 3966 return ret; 3967 } 3968 case PACKET_LOSS: 3969 { 3970 unsigned int val; 3971 3972 if (optlen != sizeof(val)) 3973 return -EINVAL; 3974 if (copy_from_sockptr(&val, optval, sizeof(val))) 3975 return -EFAULT; 3976 3977 lock_sock(sk); 3978 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3979 ret = -EBUSY; 3980 } else { 3981 packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); 3982 ret = 0; 3983 } 3984 release_sock(sk); 3985 return ret; 3986 } 3987 case PACKET_AUXDATA: 3988 { 3989 int val; 3990 3991 if (optlen < sizeof(val)) 3992 return -EINVAL; 3993 if (copy_from_sockptr(&val, optval, sizeof(val))) 3994 return -EFAULT; 3995 3996 packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); 3997 return 0; 3998 } 3999 case PACKET_ORIGDEV: 4000 { 4001 int val; 4002 4003 if (optlen < sizeof(val)) 4004 return -EINVAL; 4005 if (copy_from_sockptr(&val, optval, sizeof(val))) 4006 return -EFAULT; 4007 4008 packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); 4009 return 0; 4010 } 4011 case PACKET_VNET_HDR: 4012 case PACKET_VNET_HDR_SZ: 4013 { 4014 int val, hdr_len; 4015 4016 if (sock->type != SOCK_RAW) 4017 return -EINVAL; 4018 if (optlen < sizeof(val)) 4019 return -EINVAL; 4020 if (copy_from_sockptr(&val, optval, sizeof(val))) 4021 return -EFAULT; 4022 4023 if (optname == PACKET_VNET_HDR_SZ) { 4024 if (val && val != sizeof(struct virtio_net_hdr) && 4025 val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) 4026 return -EINVAL; 4027 hdr_len = val; 4028 } else { 4029 hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; 4030 } 4031 lock_sock(sk); 4032 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 4033 ret = -EBUSY; 4034 } else { 4035 WRITE_ONCE(po->vnet_hdr_sz, hdr_len); 4036 ret = 0; 4037 } 4038 release_sock(sk); 4039 return ret; 4040 } 4041 case PACKET_TIMESTAMP: 4042 { 4043 int val; 4044 4045 if (optlen != sizeof(val)) 4046 return -EINVAL; 4047 if (copy_from_sockptr(&val, optval, sizeof(val))) 4048 return -EFAULT; 4049 4050 WRITE_ONCE(po->tp_tstamp, val); 4051 return 0; 4052 } 4053 case PACKET_FANOUT: 4054 { 4055 struct fanout_args args = { 0 }; 4056 4057 if (optlen != sizeof(int) && optlen != sizeof(args)) 4058 return -EINVAL; 4059 if (copy_from_sockptr(&args, optval, optlen)) 4060 return -EFAULT; 4061 4062 return fanout_add(sk, &args); 4063 } 4064 case PACKET_FANOUT_DATA: 4065 { 4066 /* Paired with the WRITE_ONCE() in fanout_add() */ 4067 if (!READ_ONCE(po->fanout)) 4068 return -EINVAL; 4069 4070 return fanout_set_data(po, optval, optlen); 4071 } 4072 case PACKET_IGNORE_OUTGOING: 4073 { 4074 int val; 4075 4076 if (optlen != sizeof(val)) 4077 return -EINVAL; 4078 if (copy_from_sockptr(&val, optval, sizeof(val))) 4079 return -EFAULT; 4080 if (val < 0 || val > 1) 4081 return -EINVAL; 4082 4083 WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); 4084 return 0; 4085 } 4086 case PACKET_TX_HAS_OFF: 4087 { 4088 unsigned int val; 4089 4090 if (optlen != sizeof(val)) 4091 return -EINVAL; 4092 if (copy_from_sockptr(&val, optval, sizeof(val))) 4093 return -EFAULT; 4094 4095 lock_sock(sk); 4096 if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) 4097 packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); 4098 4099 release_sock(sk); 4100 return 0; 4101 } 4102 case PACKET_QDISC_BYPASS: 4103 { 4104 int val; 4105 4106 if (optlen != sizeof(val)) 4107 return -EINVAL; 4108 if (copy_from_sockptr(&val, optval, sizeof(val))) 4109 return -EFAULT; 4110 4111 packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); 4112 return 0; 4113 } 4114 default: 4115 return -ENOPROTOOPT; 4116 } 4117 } 4118 4119 static int packet_getsockopt(struct socket *sock, int level, int optname, 4120 char __user *optval, int __user *optlen) 4121 { 4122 int len; 4123 int val, lv = sizeof(val); 4124 struct sock *sk = sock->sk; 4125 struct packet_sock *po = pkt_sk(sk); 4126 void *data = &val; 4127 union tpacket_stats_u st; 4128 struct tpacket_rollover_stats rstats; 4129 int drops; 4130 4131 if (level != SOL_PACKET) 4132 return -ENOPROTOOPT; 4133 4134 if (get_user(len, optlen)) 4135 return -EFAULT; 4136 4137 if (len < 0) 4138 return -EINVAL; 4139 4140 switch (optname) { 4141 case PACKET_STATISTICS: 4142 spin_lock_bh(&sk->sk_receive_queue.lock); 4143 memcpy(&st, &po->stats, sizeof(st)); 4144 memset(&po->stats, 0, sizeof(po->stats)); 4145 spin_unlock_bh(&sk->sk_receive_queue.lock); 4146 drops = atomic_xchg(&po->tp_drops, 0); 4147 4148 if (po->tp_version == TPACKET_V3) { 4149 lv = sizeof(struct tpacket_stats_v3); 4150 st.stats3.tp_drops = drops; 4151 st.stats3.tp_packets += drops; 4152 data = &st.stats3; 4153 } else { 4154 lv = sizeof(struct tpacket_stats); 4155 st.stats1.tp_drops = drops; 4156 st.stats1.tp_packets += drops; 4157 data = &st.stats1; 4158 } 4159 4160 break; 4161 case PACKET_AUXDATA: 4162 val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); 4163 break; 4164 case PACKET_ORIGDEV: 4165 val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); 4166 break; 4167 case PACKET_VNET_HDR: 4168 val = !!READ_ONCE(po->vnet_hdr_sz); 4169 break; 4170 case PACKET_VNET_HDR_SZ: 4171 val = READ_ONCE(po->vnet_hdr_sz); 4172 break; 4173 case PACKET_COPY_THRESH: 4174 val = READ_ONCE(pkt_sk(sk)->copy_thresh); 4175 break; 4176 case PACKET_VERSION: 4177 val = po->tp_version; 4178 break; 4179 case PACKET_HDRLEN: 4180 if (len > sizeof(int)) 4181 len = sizeof(int); 4182 if (len < sizeof(int)) 4183 return -EINVAL; 4184 if (copy_from_user(&val, optval, len)) 4185 return -EFAULT; 4186 switch (val) { 4187 case TPACKET_V1: 4188 val = sizeof(struct tpacket_hdr); 4189 break; 4190 case TPACKET_V2: 4191 val = sizeof(struct tpacket2_hdr); 4192 break; 4193 case TPACKET_V3: 4194 val = sizeof(struct tpacket3_hdr); 4195 break; 4196 default: 4197 return -EINVAL; 4198 } 4199 break; 4200 case PACKET_RESERVE: 4201 val = po->tp_reserve; 4202 break; 4203 case PACKET_LOSS: 4204 val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); 4205 break; 4206 case PACKET_TIMESTAMP: 4207 val = READ_ONCE(po->tp_tstamp); 4208 break; 4209 case PACKET_FANOUT: 4210 val = (po->fanout ? 4211 ((u32)po->fanout->id | 4212 ((u32)po->fanout->type << 16) | 4213 ((u32)po->fanout->flags << 24)) : 4214 0); 4215 break; 4216 case PACKET_IGNORE_OUTGOING: 4217 val = READ_ONCE(po->prot_hook.ignore_outgoing); 4218 break; 4219 case PACKET_ROLLOVER_STATS: 4220 if (!po->rollover) 4221 return -EINVAL; 4222 rstats.tp_all = atomic_long_read(&po->rollover->num); 4223 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 4224 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 4225 data = &rstats; 4226 lv = sizeof(rstats); 4227 break; 4228 case PACKET_TX_HAS_OFF: 4229 val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); 4230 break; 4231 case PACKET_QDISC_BYPASS: 4232 val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); 4233 break; 4234 default: 4235 return -ENOPROTOOPT; 4236 } 4237 4238 if (len > lv) 4239 len = lv; 4240 if (put_user(len, optlen)) 4241 return -EFAULT; 4242 if (copy_to_user(optval, data, len)) 4243 return -EFAULT; 4244 return 0; 4245 } 4246 4247 static int packet_notifier(struct notifier_block *this, 4248 unsigned long msg, void *ptr) 4249 { 4250 struct sock *sk; 4251 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 4252 struct net *net = dev_net(dev); 4253 4254 rcu_read_lock(); 4255 sk_for_each_rcu(sk, &net->packet.sklist) { 4256 struct packet_sock *po = pkt_sk(sk); 4257 4258 switch (msg) { 4259 case NETDEV_UNREGISTER: 4260 if (po->mclist) 4261 packet_dev_mclist_delete(dev, &po->mclist); 4262 fallthrough; 4263 4264 case NETDEV_DOWN: 4265 if (dev->ifindex == po->ifindex) { 4266 spin_lock(&po->bind_lock); 4267 if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { 4268 __unregister_prot_hook(sk, false); 4269 sk->sk_err = ENETDOWN; 4270 if (!sock_flag(sk, SOCK_DEAD)) 4271 sk_error_report(sk); 4272 } 4273 if (msg == NETDEV_UNREGISTER) { 4274 packet_cached_dev_reset(po); 4275 WRITE_ONCE(po->ifindex, -1); 4276 netdev_put(po->prot_hook.dev, 4277 &po->prot_hook.dev_tracker); 4278 po->prot_hook.dev = NULL; 4279 } 4280 spin_unlock(&po->bind_lock); 4281 } 4282 break; 4283 case NETDEV_UP: 4284 if (dev->ifindex == po->ifindex) { 4285 spin_lock(&po->bind_lock); 4286 if (po->num) 4287 register_prot_hook(sk); 4288 spin_unlock(&po->bind_lock); 4289 } 4290 break; 4291 } 4292 } 4293 rcu_read_unlock(); 4294 return NOTIFY_DONE; 4295 } 4296 4297 4298 static int packet_ioctl(struct socket *sock, unsigned int cmd, 4299 unsigned long arg) 4300 { 4301 struct sock *sk = sock->sk; 4302 4303 switch (cmd) { 4304 case SIOCOUTQ: 4305 { 4306 int amount = sk_wmem_alloc_get(sk); 4307 4308 return put_user(amount, (int __user *)arg); 4309 } 4310 case SIOCINQ: 4311 { 4312 struct sk_buff *skb; 4313 int amount = 0; 4314 4315 spin_lock_bh(&sk->sk_receive_queue.lock); 4316 skb = skb_peek(&sk->sk_receive_queue); 4317 if (skb) 4318 amount = skb->len; 4319 spin_unlock_bh(&sk->sk_receive_queue.lock); 4320 return put_user(amount, (int __user *)arg); 4321 } 4322 #ifdef CONFIG_INET 4323 case SIOCADDRT: 4324 case SIOCDELRT: 4325 case SIOCDARP: 4326 case SIOCGARP: 4327 case SIOCSARP: 4328 case SIOCGIFADDR: 4329 case SIOCSIFADDR: 4330 case SIOCGIFBRDADDR: 4331 case SIOCSIFBRDADDR: 4332 case SIOCGIFNETMASK: 4333 case SIOCSIFNETMASK: 4334 case SIOCGIFDSTADDR: 4335 case SIOCSIFDSTADDR: 4336 case SIOCSIFFLAGS: 4337 return inet_dgram_ops.ioctl(sock, cmd, arg); 4338 #endif 4339 4340 default: 4341 return -ENOIOCTLCMD; 4342 } 4343 return 0; 4344 } 4345 4346 static __poll_t packet_poll(struct file *file, struct socket *sock, 4347 poll_table *wait) 4348 { 4349 struct sock *sk = sock->sk; 4350 struct packet_sock *po = pkt_sk(sk); 4351 __poll_t mask = datagram_poll(file, sock, wait); 4352 4353 spin_lock_bh(&sk->sk_receive_queue.lock); 4354 if (po->rx_ring.pg_vec) { 4355 if (!packet_previous_rx_frame(po, &po->rx_ring, 4356 TP_STATUS_KERNEL)) 4357 mask |= EPOLLIN | EPOLLRDNORM; 4358 } 4359 packet_rcv_try_clear_pressure(po); 4360 spin_unlock_bh(&sk->sk_receive_queue.lock); 4361 spin_lock_bh(&sk->sk_write_queue.lock); 4362 if (po->tx_ring.pg_vec) { 4363 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4364 mask |= EPOLLOUT | EPOLLWRNORM; 4365 } 4366 spin_unlock_bh(&sk->sk_write_queue.lock); 4367 return mask; 4368 } 4369 4370 4371 /* Dirty? Well, I still did not learn better way to account 4372 * for user mmaps. 4373 */ 4374 4375 static void packet_mm_open(struct vm_area_struct *vma) 4376 { 4377 struct file *file = vma->vm_file; 4378 struct socket *sock = file->private_data; 4379 struct sock *sk = sock->sk; 4380 4381 if (sk) 4382 atomic_long_inc(&pkt_sk(sk)->mapped); 4383 } 4384 4385 static void packet_mm_close(struct vm_area_struct *vma) 4386 { 4387 struct file *file = vma->vm_file; 4388 struct socket *sock = file->private_data; 4389 struct sock *sk = sock->sk; 4390 4391 if (sk) 4392 atomic_long_dec(&pkt_sk(sk)->mapped); 4393 } 4394 4395 static const struct vm_operations_struct packet_mmap_ops = { 4396 .open = packet_mm_open, 4397 .close = packet_mm_close, 4398 }; 4399 4400 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4401 unsigned int len) 4402 { 4403 int i; 4404 4405 for (i = 0; i < len; i++) { 4406 if (likely(pg_vec[i].buffer)) { 4407 if (is_vmalloc_addr(pg_vec[i].buffer)) 4408 vfree(pg_vec[i].buffer); 4409 else 4410 free_pages((unsigned long)pg_vec[i].buffer, 4411 order); 4412 pg_vec[i].buffer = NULL; 4413 } 4414 } 4415 kfree(pg_vec); 4416 } 4417 4418 static char *alloc_one_pg_vec_page(unsigned long order) 4419 { 4420 char *buffer; 4421 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4422 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4423 4424 buffer = (char *) __get_free_pages(gfp_flags, order); 4425 if (buffer) 4426 return buffer; 4427 4428 /* __get_free_pages failed, fall back to vmalloc */ 4429 buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); 4430 if (buffer) 4431 return buffer; 4432 4433 /* vmalloc failed, lets dig into swap here */ 4434 gfp_flags &= ~__GFP_NORETRY; 4435 buffer = (char *) __get_free_pages(gfp_flags, order); 4436 if (buffer) 4437 return buffer; 4438 4439 /* complete and utter failure */ 4440 return NULL; 4441 } 4442 4443 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4444 { 4445 unsigned int block_nr = req->tp_block_nr; 4446 struct pgv *pg_vec; 4447 int i; 4448 4449 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN); 4450 if (unlikely(!pg_vec)) 4451 goto out; 4452 4453 for (i = 0; i < block_nr; i++) { 4454 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4455 if (unlikely(!pg_vec[i].buffer)) 4456 goto out_free_pgvec; 4457 } 4458 4459 out: 4460 return pg_vec; 4461 4462 out_free_pgvec: 4463 free_pg_vec(pg_vec, order, block_nr); 4464 pg_vec = NULL; 4465 goto out; 4466 } 4467 4468 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4469 int closing, int tx_ring) 4470 { 4471 struct pgv *pg_vec = NULL; 4472 struct packet_sock *po = pkt_sk(sk); 4473 unsigned long *rx_owner_map = NULL; 4474 int was_running, order = 0; 4475 struct packet_ring_buffer *rb; 4476 struct sk_buff_head *rb_queue; 4477 __be16 num; 4478 int err; 4479 /* Added to avoid minimal code churn */ 4480 struct tpacket_req *req = &req_u->req; 4481 4482 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4483 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4484 4485 err = -EBUSY; 4486 if (!closing) { 4487 if (atomic_long_read(&po->mapped)) 4488 goto out; 4489 if (packet_read_pending(rb)) 4490 goto out; 4491 } 4492 4493 if (req->tp_block_nr) { 4494 unsigned int min_frame_size; 4495 4496 /* Sanity tests and some calculations */ 4497 err = -EBUSY; 4498 if (unlikely(rb->pg_vec)) 4499 goto out; 4500 4501 switch (po->tp_version) { 4502 case TPACKET_V1: 4503 po->tp_hdrlen = TPACKET_HDRLEN; 4504 break; 4505 case TPACKET_V2: 4506 po->tp_hdrlen = TPACKET2_HDRLEN; 4507 break; 4508 case TPACKET_V3: 4509 po->tp_hdrlen = TPACKET3_HDRLEN; 4510 break; 4511 } 4512 4513 err = -EINVAL; 4514 if (unlikely((int)req->tp_block_size <= 0)) 4515 goto out; 4516 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4517 goto out; 4518 min_frame_size = po->tp_hdrlen + po->tp_reserve; 4519 if (po->tp_version >= TPACKET_V3 && 4520 req->tp_block_size < 4521 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) 4522 goto out; 4523 if (unlikely(req->tp_frame_size < min_frame_size)) 4524 goto out; 4525 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4526 goto out; 4527 4528 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4529 if (unlikely(rb->frames_per_block == 0)) 4530 goto out; 4531 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) 4532 goto out; 4533 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4534 req->tp_frame_nr)) 4535 goto out; 4536 4537 err = -ENOMEM; 4538 order = get_order(req->tp_block_size); 4539 pg_vec = alloc_pg_vec(req, order); 4540 if (unlikely(!pg_vec)) 4541 goto out; 4542 switch (po->tp_version) { 4543 case TPACKET_V3: 4544 /* Block transmit is not supported yet */ 4545 if (!tx_ring) { 4546 init_prb_bdqc(po, rb, pg_vec, req_u); 4547 } else { 4548 struct tpacket_req3 *req3 = &req_u->req3; 4549 4550 if (req3->tp_retire_blk_tov || 4551 req3->tp_sizeof_priv || 4552 req3->tp_feature_req_word) { 4553 err = -EINVAL; 4554 goto out_free_pg_vec; 4555 } 4556 } 4557 break; 4558 default: 4559 if (!tx_ring) { 4560 rx_owner_map = bitmap_alloc(req->tp_frame_nr, 4561 GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); 4562 if (!rx_owner_map) 4563 goto out_free_pg_vec; 4564 } 4565 break; 4566 } 4567 } 4568 /* Done */ 4569 else { 4570 err = -EINVAL; 4571 if (unlikely(req->tp_frame_nr)) 4572 goto out; 4573 } 4574 4575 4576 /* Detach socket from network */ 4577 spin_lock(&po->bind_lock); 4578 was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); 4579 num = po->num; 4580 if (was_running) { 4581 WRITE_ONCE(po->num, 0); 4582 __unregister_prot_hook(sk, false); 4583 } 4584 spin_unlock(&po->bind_lock); 4585 4586 synchronize_net(); 4587 4588 err = -EBUSY; 4589 mutex_lock(&po->pg_vec_lock); 4590 if (closing || atomic_long_read(&po->mapped) == 0) { 4591 err = 0; 4592 spin_lock_bh(&rb_queue->lock); 4593 swap(rb->pg_vec, pg_vec); 4594 if (po->tp_version <= TPACKET_V2) 4595 swap(rb->rx_owner_map, rx_owner_map); 4596 rb->frame_max = (req->tp_frame_nr - 1); 4597 rb->head = 0; 4598 rb->frame_size = req->tp_frame_size; 4599 spin_unlock_bh(&rb_queue->lock); 4600 4601 swap(rb->pg_vec_order, order); 4602 swap(rb->pg_vec_len, req->tp_block_nr); 4603 4604 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4605 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4606 tpacket_rcv : packet_rcv; 4607 skb_queue_purge(rb_queue); 4608 if (atomic_long_read(&po->mapped)) 4609 pr_err("packet_mmap: vma is busy: %ld\n", 4610 atomic_long_read(&po->mapped)); 4611 } 4612 mutex_unlock(&po->pg_vec_lock); 4613 4614 spin_lock(&po->bind_lock); 4615 if (was_running) { 4616 WRITE_ONCE(po->num, num); 4617 register_prot_hook(sk); 4618 } 4619 spin_unlock(&po->bind_lock); 4620 if (pg_vec && (po->tp_version > TPACKET_V2)) { 4621 /* Because we don't support block-based V3 on tx-ring */ 4622 if (!tx_ring) 4623 prb_shutdown_retire_blk_timer(po, rb_queue); 4624 } 4625 4626 out_free_pg_vec: 4627 if (pg_vec) { 4628 bitmap_free(rx_owner_map); 4629 free_pg_vec(pg_vec, order, req->tp_block_nr); 4630 } 4631 out: 4632 return err; 4633 } 4634 4635 static int packet_mmap(struct file *file, struct socket *sock, 4636 struct vm_area_struct *vma) 4637 { 4638 struct sock *sk = sock->sk; 4639 struct packet_sock *po = pkt_sk(sk); 4640 unsigned long size, expected_size; 4641 struct packet_ring_buffer *rb; 4642 unsigned long start; 4643 int err = -EINVAL; 4644 int i; 4645 4646 if (vma->vm_pgoff) 4647 return -EINVAL; 4648 4649 mutex_lock(&po->pg_vec_lock); 4650 4651 expected_size = 0; 4652 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4653 if (rb->pg_vec) { 4654 expected_size += rb->pg_vec_len 4655 * rb->pg_vec_pages 4656 * PAGE_SIZE; 4657 } 4658 } 4659 4660 if (expected_size == 0) 4661 goto out; 4662 4663 size = vma->vm_end - vma->vm_start; 4664 if (size != expected_size) 4665 goto out; 4666 4667 start = vma->vm_start; 4668 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4669 if (rb->pg_vec == NULL) 4670 continue; 4671 4672 for (i = 0; i < rb->pg_vec_len; i++) { 4673 struct page *page; 4674 void *kaddr = rb->pg_vec[i].buffer; 4675 int pg_num; 4676 4677 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4678 page = pgv_to_page(kaddr); 4679 err = vm_insert_page(vma, start, page); 4680 if (unlikely(err)) 4681 goto out; 4682 start += PAGE_SIZE; 4683 kaddr += PAGE_SIZE; 4684 } 4685 } 4686 } 4687 4688 atomic_long_inc(&po->mapped); 4689 vma->vm_ops = &packet_mmap_ops; 4690 err = 0; 4691 4692 out: 4693 mutex_unlock(&po->pg_vec_lock); 4694 return err; 4695 } 4696 4697 static const struct proto_ops packet_ops_spkt = { 4698 .family = PF_PACKET, 4699 .owner = THIS_MODULE, 4700 .release = packet_release, 4701 .bind = packet_bind_spkt, 4702 .connect = sock_no_connect, 4703 .socketpair = sock_no_socketpair, 4704 .accept = sock_no_accept, 4705 .getname = packet_getname_spkt, 4706 .poll = datagram_poll, 4707 .ioctl = packet_ioctl, 4708 .gettstamp = sock_gettstamp, 4709 .listen = sock_no_listen, 4710 .shutdown = sock_no_shutdown, 4711 .sendmsg = packet_sendmsg_spkt, 4712 .recvmsg = packet_recvmsg, 4713 .mmap = sock_no_mmap, 4714 }; 4715 4716 static const struct proto_ops packet_ops = { 4717 .family = PF_PACKET, 4718 .owner = THIS_MODULE, 4719 .release = packet_release, 4720 .bind = packet_bind, 4721 .connect = sock_no_connect, 4722 .socketpair = sock_no_socketpair, 4723 .accept = sock_no_accept, 4724 .getname = packet_getname, 4725 .poll = packet_poll, 4726 .ioctl = packet_ioctl, 4727 .gettstamp = sock_gettstamp, 4728 .listen = sock_no_listen, 4729 .shutdown = sock_no_shutdown, 4730 .setsockopt = packet_setsockopt, 4731 .getsockopt = packet_getsockopt, 4732 .sendmsg = packet_sendmsg, 4733 .recvmsg = packet_recvmsg, 4734 .mmap = packet_mmap, 4735 }; 4736 4737 static const struct net_proto_family packet_family_ops = { 4738 .family = PF_PACKET, 4739 .create = packet_create, 4740 .owner = THIS_MODULE, 4741 }; 4742 4743 static struct notifier_block packet_netdev_notifier = { 4744 .notifier_call = packet_notifier, 4745 }; 4746 4747 #ifdef CONFIG_PROC_FS 4748 4749 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4750 __acquires(RCU) 4751 { 4752 struct net *net = seq_file_net(seq); 4753 4754 rcu_read_lock(); 4755 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4756 } 4757 4758 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4759 { 4760 struct net *net = seq_file_net(seq); 4761 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4762 } 4763 4764 static void packet_seq_stop(struct seq_file *seq, void *v) 4765 __releases(RCU) 4766 { 4767 rcu_read_unlock(); 4768 } 4769 4770 static int packet_seq_show(struct seq_file *seq, void *v) 4771 { 4772 if (v == SEQ_START_TOKEN) 4773 seq_printf(seq, 4774 "%*sRefCnt Type Proto Iface R Rmem User Inode\n", 4775 IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); 4776 else { 4777 struct sock *s = sk_entry(v); 4778 const struct packet_sock *po = pkt_sk(s); 4779 4780 seq_printf(seq, 4781 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4782 s, 4783 refcount_read(&s->sk_refcnt), 4784 s->sk_type, 4785 ntohs(READ_ONCE(po->num)), 4786 READ_ONCE(po->ifindex), 4787 packet_sock_flag(po, PACKET_SOCK_RUNNING), 4788 atomic_read(&s->sk_rmem_alloc), 4789 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4790 sock_i_ino(s)); 4791 } 4792 4793 return 0; 4794 } 4795 4796 static const struct seq_operations packet_seq_ops = { 4797 .start = packet_seq_start, 4798 .next = packet_seq_next, 4799 .stop = packet_seq_stop, 4800 .show = packet_seq_show, 4801 }; 4802 #endif 4803 4804 static int __net_init packet_net_init(struct net *net) 4805 { 4806 mutex_init(&net->packet.sklist_lock); 4807 INIT_HLIST_HEAD(&net->packet.sklist); 4808 4809 #ifdef CONFIG_PROC_FS 4810 if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, 4811 sizeof(struct seq_net_private))) 4812 return -ENOMEM; 4813 #endif /* CONFIG_PROC_FS */ 4814 4815 return 0; 4816 } 4817 4818 static void __net_exit packet_net_exit(struct net *net) 4819 { 4820 remove_proc_entry("packet", net->proc_net); 4821 WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); 4822 } 4823 4824 static struct pernet_operations packet_net_ops = { 4825 .init = packet_net_init, 4826 .exit = packet_net_exit, 4827 }; 4828 4829 4830 static void __exit packet_exit(void) 4831 { 4832 sock_unregister(PF_PACKET); 4833 proto_unregister(&packet_proto); 4834 unregister_netdevice_notifier(&packet_netdev_notifier); 4835 unregister_pernet_subsys(&packet_net_ops); 4836 } 4837 4838 static int __init packet_init(void) 4839 { 4840 int rc; 4841 4842 rc = register_pernet_subsys(&packet_net_ops); 4843 if (rc) 4844 goto out; 4845 rc = register_netdevice_notifier(&packet_netdev_notifier); 4846 if (rc) 4847 goto out_pernet; 4848 rc = proto_register(&packet_proto, 0); 4849 if (rc) 4850 goto out_notifier; 4851 rc = sock_register(&packet_family_ops); 4852 if (rc) 4853 goto out_proto; 4854 4855 return 0; 4856 4857 out_proto: 4858 proto_unregister(&packet_proto); 4859 out_notifier: 4860 unregister_netdevice_notifier(&packet_netdev_notifier); 4861 out_pernet: 4862 unregister_pernet_subsys(&packet_net_ops); 4863 out: 4864 return rc; 4865 } 4866 4867 module_init(packet_init); 4868 module_exit(packet_exit); 4869 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)"); 4870 MODULE_LICENSE("GPL"); 4871 MODULE_ALIAS_NETPROTO(PF_PACKET); 4872