1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Version: $Id: af_packet.c,v 1.61 2002/02/08 03:57:19 davem Exp $ 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Alan Cox, <gw4pts@gw4pts.ampr.org> 13 * 14 * Fixes: 15 * Alan Cox : verify_area() now used correctly 16 * Alan Cox : new skbuff lists, look ma no backlogs! 17 * Alan Cox : tidied skbuff lists. 18 * Alan Cox : Now uses generic datagram routines I 19 * added. Also fixed the peek/read crash 20 * from all old Linux datagram code. 21 * Alan Cox : Uses the improved datagram code. 22 * Alan Cox : Added NULL's for socket options. 23 * Alan Cox : Re-commented the code. 24 * Alan Cox : Use new kernel side addressing 25 * Rob Janssen : Correct MTU usage. 26 * Dave Platt : Counter leaks caused by incorrect 27 * interrupt locking and some slightly 28 * dubious gcc output. Can you read 29 * compiler: it said _VOLATILE_ 30 * Richard Kooijman : Timestamp fixes. 31 * Alan Cox : New buffers. Use sk->mac.raw. 32 * Alan Cox : sendmsg/recvmsg support. 33 * Alan Cox : Protocol setting support 34 * Alexey Kuznetsov : Untied from IPv4 stack. 35 * Cyrus Durgin : Fixed kerneld for kmod. 36 * Michal Ostrowski : Module initialization cleanup. 37 * Ulises Alonso : Frame number limit removal and 38 * packet_set_ring memory leak. 39 * Eric Biederman : Allow for > 8 byte hardware addresses. 40 * The convention is that longer addresses 41 * will simply extend the hardware address 42 * byte arrays at the end of sockaddr_ll 43 * and packet_mreq. 44 * 45 * This program is free software; you can redistribute it and/or 46 * modify it under the terms of the GNU General Public License 47 * as published by the Free Software Foundation; either version 48 * 2 of the License, or (at your option) any later version. 49 * 50 */ 51 52 #include <linux/types.h> 53 #include <linux/sched.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/kmod.h> 64 #include <net/ip.h> 65 #include <net/protocol.h> 66 #include <linux/skbuff.h> 67 #include <net/sock.h> 68 #include <linux/errno.h> 69 #include <linux/timer.h> 70 #include <asm/system.h> 71 #include <asm/uaccess.h> 72 #include <asm/ioctls.h> 73 #include <asm/page.h> 74 #include <asm/io.h> 75 #include <linux/proc_fs.h> 76 #include <linux/seq_file.h> 77 #include <linux/poll.h> 78 #include <linux/module.h> 79 #include <linux/init.h> 80 81 #ifdef CONFIG_INET 82 #include <net/inet_common.h> 83 #endif 84 85 #define CONFIG_SOCK_PACKET 1 86 87 /* 88 Proposed replacement for SIOC{ADD,DEL}MULTI and 89 IFF_PROMISC, IFF_ALLMULTI flags. 90 91 It is more expensive, but I believe, 92 it is really correct solution: reentereble, safe and fault tolerant. 93 94 IFF_PROMISC/IFF_ALLMULTI/SIOC{ADD/DEL}MULTI are faked by keeping 95 reference count and global flag, so that real status is 96 (gflag|(count != 0)), so that we can use obsolete faulty interface 97 not harming clever users. 98 */ 99 #define CONFIG_PACKET_MULTICAST 1 100 101 /* 102 Assumptions: 103 - if device has no dev->hard_header routine, it adds and removes ll header 104 inside itself. In this case ll header is invisible outside of device, 105 but higher levels still should reserve dev->hard_header_len. 106 Some devices are enough clever to reallocate skb, when header 107 will not fit to reserved space (tunnel), another ones are silly 108 (PPP). 109 - packet socket receives packets with pulled ll header, 110 so that SOCK_RAW should push it back. 111 112 On receive: 113 ----------- 114 115 Incoming, dev->hard_header!=NULL 116 mac.raw -> ll header 117 data -> data 118 119 Outgoing, dev->hard_header!=NULL 120 mac.raw -> ll header 121 data -> ll header 122 123 Incoming, dev->hard_header==NULL 124 mac.raw -> UNKNOWN position. It is very likely, that it points to ll header. 125 PPP makes it, that is wrong, because introduce assymetry 126 between rx and tx paths. 127 data -> data 128 129 Outgoing, dev->hard_header==NULL 130 mac.raw -> data. ll header is still not built! 131 data -> data 132 133 Resume 134 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 135 136 137 On transmit: 138 ------------ 139 140 dev->hard_header != NULL 141 mac.raw -> ll header 142 data -> ll header 143 144 dev->hard_header == NULL (ll header is added by device, we cannot control it) 145 mac.raw -> data 146 data -> data 147 148 We should set nh.raw on output to correct posistion, 149 packet classifier depends on it. 150 */ 151 152 /* List of all packet sockets. */ 153 static HLIST_HEAD(packet_sklist); 154 static DEFINE_RWLOCK(packet_sklist_lock); 155 156 static atomic_t packet_socks_nr; 157 158 159 /* Private packet socket structures. */ 160 161 #ifdef CONFIG_PACKET_MULTICAST 162 struct packet_mclist 163 { 164 struct packet_mclist *next; 165 int ifindex; 166 int count; 167 unsigned short type; 168 unsigned short alen; 169 unsigned char addr[MAX_ADDR_LEN]; 170 }; 171 /* identical to struct packet_mreq except it has 172 * a longer address field. 173 */ 174 struct packet_mreq_max 175 { 176 int mr_ifindex; 177 unsigned short mr_type; 178 unsigned short mr_alen; 179 unsigned char mr_address[MAX_ADDR_LEN]; 180 }; 181 #endif 182 #ifdef CONFIG_PACKET_MMAP 183 static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing); 184 #endif 185 186 static void packet_flush_mclist(struct sock *sk); 187 188 struct packet_sock { 189 /* struct sock has to be the first member of packet_sock */ 190 struct sock sk; 191 struct tpacket_stats stats; 192 #ifdef CONFIG_PACKET_MMAP 193 char * *pg_vec; 194 unsigned int head; 195 unsigned int frames_per_block; 196 unsigned int frame_size; 197 unsigned int frame_max; 198 int copy_thresh; 199 #endif 200 struct packet_type prot_hook; 201 spinlock_t bind_lock; 202 char running; /* prot_hook is attached*/ 203 int ifindex; /* bound device */ 204 unsigned short num; 205 #ifdef CONFIG_PACKET_MULTICAST 206 struct packet_mclist *mclist; 207 #endif 208 #ifdef CONFIG_PACKET_MMAP 209 atomic_t mapped; 210 unsigned int pg_vec_order; 211 unsigned int pg_vec_pages; 212 unsigned int pg_vec_len; 213 #endif 214 }; 215 216 #ifdef CONFIG_PACKET_MMAP 217 218 static inline char *packet_lookup_frame(struct packet_sock *po, unsigned int position) 219 { 220 unsigned int pg_vec_pos, frame_offset; 221 char *frame; 222 223 pg_vec_pos = position / po->frames_per_block; 224 frame_offset = position % po->frames_per_block; 225 226 frame = po->pg_vec[pg_vec_pos] + (frame_offset * po->frame_size); 227 228 return frame; 229 } 230 #endif 231 232 static inline struct packet_sock *pkt_sk(struct sock *sk) 233 { 234 return (struct packet_sock *)sk; 235 } 236 237 static void packet_sock_destruct(struct sock *sk) 238 { 239 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); 240 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); 241 242 if (!sock_flag(sk, SOCK_DEAD)) { 243 printk("Attempt to release alive packet socket: %p\n", sk); 244 return; 245 } 246 247 atomic_dec(&packet_socks_nr); 248 #ifdef PACKET_REFCNT_DEBUG 249 printk(KERN_DEBUG "PACKET socket %p is free, %d are alive\n", sk, atomic_read(&packet_socks_nr)); 250 #endif 251 } 252 253 254 static const struct proto_ops packet_ops; 255 256 #ifdef CONFIG_SOCK_PACKET 257 static const struct proto_ops packet_ops_spkt; 258 259 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 260 { 261 struct sock *sk; 262 struct sockaddr_pkt *spkt; 263 264 /* 265 * When we registered the protocol we saved the socket in the data 266 * field for just this event. 267 */ 268 269 sk = pt->af_packet_priv; 270 271 /* 272 * Yank back the headers [hope the device set this 273 * right or kerboom...] 274 * 275 * Incoming packets have ll header pulled, 276 * push it back. 277 * 278 * For outgoing ones skb->data == skb->mac.raw 279 * so that this procedure is noop. 280 */ 281 282 if (skb->pkt_type == PACKET_LOOPBACK) 283 goto out; 284 285 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 286 goto oom; 287 288 /* drop any routing info */ 289 dst_release(skb->dst); 290 skb->dst = NULL; 291 292 /* drop conntrack reference */ 293 nf_reset(skb); 294 295 spkt = (struct sockaddr_pkt*)skb->cb; 296 297 skb_push(skb, skb->data-skb->mac.raw); 298 299 /* 300 * The SOCK_PACKET socket receives _all_ frames. 301 */ 302 303 spkt->spkt_family = dev->type; 304 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 305 spkt->spkt_protocol = skb->protocol; 306 307 /* 308 * Charge the memory to the socket. This is done specifically 309 * to prevent sockets using all the memory up. 310 */ 311 312 if (sock_queue_rcv_skb(sk,skb) == 0) 313 return 0; 314 315 out: 316 kfree_skb(skb); 317 oom: 318 return 0; 319 } 320 321 322 /* 323 * Output a raw packet to a device layer. This bypasses all the other 324 * protocol layers and you must therefore supply it with a complete frame 325 */ 326 327 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, 328 struct msghdr *msg, size_t len) 329 { 330 struct sock *sk = sock->sk; 331 struct sockaddr_pkt *saddr=(struct sockaddr_pkt *)msg->msg_name; 332 struct sk_buff *skb; 333 struct net_device *dev; 334 unsigned short proto=0; 335 int err; 336 337 /* 338 * Get and verify the address. 339 */ 340 341 if (saddr) 342 { 343 if (msg->msg_namelen < sizeof(struct sockaddr)) 344 return(-EINVAL); 345 if (msg->msg_namelen==sizeof(struct sockaddr_pkt)) 346 proto=saddr->spkt_protocol; 347 } 348 else 349 return(-ENOTCONN); /* SOCK_PACKET must be sent giving an address */ 350 351 /* 352 * Find the device first to size check it 353 */ 354 355 saddr->spkt_device[13] = 0; 356 dev = dev_get_by_name(saddr->spkt_device); 357 err = -ENODEV; 358 if (dev == NULL) 359 goto out_unlock; 360 361 /* 362 * You may not queue a frame bigger than the mtu. This is the lowest level 363 * raw protocol and you must do your own fragmentation at this level. 364 */ 365 366 err = -EMSGSIZE; 367 if (len > dev->mtu + dev->hard_header_len) 368 goto out_unlock; 369 370 err = -ENOBUFS; 371 skb = sock_wmalloc(sk, len + LL_RESERVED_SPACE(dev), 0, GFP_KERNEL); 372 373 /* 374 * If the write buffer is full, then tough. At this level the user gets to 375 * deal with the problem - do your own algorithmic backoffs. That's far 376 * more flexible. 377 */ 378 379 if (skb == NULL) 380 goto out_unlock; 381 382 /* 383 * Fill it in 384 */ 385 386 /* FIXME: Save some space for broken drivers that write a 387 * hard header at transmission time by themselves. PPP is the 388 * notable one here. This should really be fixed at the driver level. 389 */ 390 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 391 skb->nh.raw = skb->data; 392 393 /* Try to align data part correctly */ 394 if (dev->hard_header) { 395 skb->data -= dev->hard_header_len; 396 skb->tail -= dev->hard_header_len; 397 if (len < dev->hard_header_len) 398 skb->nh.raw = skb->data; 399 } 400 401 /* Returns -EFAULT on error */ 402 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); 403 skb->protocol = proto; 404 skb->dev = dev; 405 skb->priority = sk->sk_priority; 406 if (err) 407 goto out_free; 408 409 err = -ENETDOWN; 410 if (!(dev->flags & IFF_UP)) 411 goto out_free; 412 413 /* 414 * Now send it 415 */ 416 417 dev_queue_xmit(skb); 418 dev_put(dev); 419 return(len); 420 421 out_free: 422 kfree_skb(skb); 423 out_unlock: 424 if (dev) 425 dev_put(dev); 426 return err; 427 } 428 #endif 429 430 static inline unsigned run_filter(struct sk_buff *skb, struct sock *sk, unsigned res) 431 { 432 struct sk_filter *filter; 433 434 bh_lock_sock(sk); 435 filter = sk->sk_filter; 436 /* 437 * Our caller already checked that filter != NULL but we need to 438 * verify that under bh_lock_sock() to be safe 439 */ 440 if (likely(filter != NULL)) 441 res = sk_run_filter(skb, filter->insns, filter->len); 442 bh_unlock_sock(sk); 443 444 return res; 445 } 446 447 /* 448 This function makes lazy skb cloning in hope that most of packets 449 are discarded by BPF. 450 451 Note tricky part: we DO mangle shared skb! skb->data, skb->len 452 and skb->cb are mangled. It works because (and until) packets 453 falling here are owned by current CPU. Output packets are cloned 454 by dev_queue_xmit_nit(), input packets are processed by net_bh 455 sequencially, so that if we return skb to original state on exit, 456 we will not harm anyone. 457 */ 458 459 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 460 { 461 struct sock *sk; 462 struct sockaddr_ll *sll; 463 struct packet_sock *po; 464 u8 * skb_head = skb->data; 465 int skb_len = skb->len; 466 unsigned snaplen; 467 468 if (skb->pkt_type == PACKET_LOOPBACK) 469 goto drop; 470 471 sk = pt->af_packet_priv; 472 po = pkt_sk(sk); 473 474 skb->dev = dev; 475 476 if (dev->hard_header) { 477 /* The device has an explicit notion of ll header, 478 exported to higher levels. 479 480 Otherwise, the device hides datails of it frame 481 structure, so that corresponding packet head 482 never delivered to user. 483 */ 484 if (sk->sk_type != SOCK_DGRAM) 485 skb_push(skb, skb->data - skb->mac.raw); 486 else if (skb->pkt_type == PACKET_OUTGOING) { 487 /* Special case: outgoing packets have ll header at head */ 488 skb_pull(skb, skb->nh.raw - skb->data); 489 } 490 } 491 492 snaplen = skb->len; 493 494 if (sk->sk_filter) { 495 unsigned res = run_filter(skb, sk, snaplen); 496 if (res == 0) 497 goto drop_n_restore; 498 if (snaplen > res) 499 snaplen = res; 500 } 501 502 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 503 (unsigned)sk->sk_rcvbuf) 504 goto drop_n_acct; 505 506 if (skb_shared(skb)) { 507 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 508 if (nskb == NULL) 509 goto drop_n_acct; 510 511 if (skb_head != skb->data) { 512 skb->data = skb_head; 513 skb->len = skb_len; 514 } 515 kfree_skb(skb); 516 skb = nskb; 517 } 518 519 sll = (struct sockaddr_ll*)skb->cb; 520 sll->sll_family = AF_PACKET; 521 sll->sll_hatype = dev->type; 522 sll->sll_protocol = skb->protocol; 523 sll->sll_pkttype = skb->pkt_type; 524 sll->sll_ifindex = dev->ifindex; 525 sll->sll_halen = 0; 526 527 if (dev->hard_header_parse) 528 sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr); 529 530 if (pskb_trim(skb, snaplen)) 531 goto drop_n_acct; 532 533 skb_set_owner_r(skb, sk); 534 skb->dev = NULL; 535 dst_release(skb->dst); 536 skb->dst = NULL; 537 538 /* drop conntrack reference */ 539 nf_reset(skb); 540 541 spin_lock(&sk->sk_receive_queue.lock); 542 po->stats.tp_packets++; 543 __skb_queue_tail(&sk->sk_receive_queue, skb); 544 spin_unlock(&sk->sk_receive_queue.lock); 545 sk->sk_data_ready(sk, skb->len); 546 return 0; 547 548 drop_n_acct: 549 spin_lock(&sk->sk_receive_queue.lock); 550 po->stats.tp_drops++; 551 spin_unlock(&sk->sk_receive_queue.lock); 552 553 drop_n_restore: 554 if (skb_head != skb->data && skb_shared(skb)) { 555 skb->data = skb_head; 556 skb->len = skb_len; 557 } 558 drop: 559 kfree_skb(skb); 560 return 0; 561 } 562 563 #ifdef CONFIG_PACKET_MMAP 564 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 565 { 566 struct sock *sk; 567 struct packet_sock *po; 568 struct sockaddr_ll *sll; 569 struct tpacket_hdr *h; 570 u8 * skb_head = skb->data; 571 int skb_len = skb->len; 572 unsigned snaplen; 573 unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER; 574 unsigned short macoff, netoff; 575 struct sk_buff *copy_skb = NULL; 576 577 if (skb->pkt_type == PACKET_LOOPBACK) 578 goto drop; 579 580 sk = pt->af_packet_priv; 581 po = pkt_sk(sk); 582 583 if (dev->hard_header) { 584 if (sk->sk_type != SOCK_DGRAM) 585 skb_push(skb, skb->data - skb->mac.raw); 586 else if (skb->pkt_type == PACKET_OUTGOING) { 587 /* Special case: outgoing packets have ll header at head */ 588 skb_pull(skb, skb->nh.raw - skb->data); 589 if (skb->ip_summed == CHECKSUM_HW) 590 status |= TP_STATUS_CSUMNOTREADY; 591 } 592 } 593 594 snaplen = skb->len; 595 596 if (sk->sk_filter) { 597 unsigned res = run_filter(skb, sk, snaplen); 598 if (res == 0) 599 goto drop_n_restore; 600 if (snaplen > res) 601 snaplen = res; 602 } 603 604 if (sk->sk_type == SOCK_DGRAM) { 605 macoff = netoff = TPACKET_ALIGN(TPACKET_HDRLEN) + 16; 606 } else { 607 unsigned maclen = skb->nh.raw - skb->data; 608 netoff = TPACKET_ALIGN(TPACKET_HDRLEN + (maclen < 16 ? 16 : maclen)); 609 macoff = netoff - maclen; 610 } 611 612 if (macoff + snaplen > po->frame_size) { 613 if (po->copy_thresh && 614 atomic_read(&sk->sk_rmem_alloc) + skb->truesize < 615 (unsigned)sk->sk_rcvbuf) { 616 if (skb_shared(skb)) { 617 copy_skb = skb_clone(skb, GFP_ATOMIC); 618 } else { 619 copy_skb = skb_get(skb); 620 skb_head = skb->data; 621 } 622 if (copy_skb) 623 skb_set_owner_r(copy_skb, sk); 624 } 625 snaplen = po->frame_size - macoff; 626 if ((int)snaplen < 0) 627 snaplen = 0; 628 } 629 630 spin_lock(&sk->sk_receive_queue.lock); 631 h = (struct tpacket_hdr *)packet_lookup_frame(po, po->head); 632 633 if (h->tp_status) 634 goto ring_is_full; 635 po->head = po->head != po->frame_max ? po->head+1 : 0; 636 po->stats.tp_packets++; 637 if (copy_skb) { 638 status |= TP_STATUS_COPY; 639 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 640 } 641 if (!po->stats.tp_drops) 642 status &= ~TP_STATUS_LOSING; 643 spin_unlock(&sk->sk_receive_queue.lock); 644 645 skb_copy_bits(skb, 0, (u8*)h + macoff, snaplen); 646 647 h->tp_len = skb->len; 648 h->tp_snaplen = snaplen; 649 h->tp_mac = macoff; 650 h->tp_net = netoff; 651 if (skb->tstamp.off_sec == 0) { 652 __net_timestamp(skb); 653 sock_enable_timestamp(sk); 654 } 655 h->tp_sec = skb->tstamp.off_sec; 656 h->tp_usec = skb->tstamp.off_usec; 657 658 sll = (struct sockaddr_ll*)((u8*)h + TPACKET_ALIGN(sizeof(*h))); 659 sll->sll_halen = 0; 660 if (dev->hard_header_parse) 661 sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr); 662 sll->sll_family = AF_PACKET; 663 sll->sll_hatype = dev->type; 664 sll->sll_protocol = skb->protocol; 665 sll->sll_pkttype = skb->pkt_type; 666 sll->sll_ifindex = dev->ifindex; 667 668 h->tp_status = status; 669 mb(); 670 671 { 672 struct page *p_start, *p_end; 673 u8 *h_end = (u8 *)h + macoff + snaplen - 1; 674 675 p_start = virt_to_page(h); 676 p_end = virt_to_page(h_end); 677 while (p_start <= p_end) { 678 flush_dcache_page(p_start); 679 p_start++; 680 } 681 } 682 683 sk->sk_data_ready(sk, 0); 684 685 drop_n_restore: 686 if (skb_head != skb->data && skb_shared(skb)) { 687 skb->data = skb_head; 688 skb->len = skb_len; 689 } 690 drop: 691 kfree_skb(skb); 692 return 0; 693 694 ring_is_full: 695 po->stats.tp_drops++; 696 spin_unlock(&sk->sk_receive_queue.lock); 697 698 sk->sk_data_ready(sk, 0); 699 if (copy_skb) 700 kfree_skb(copy_skb); 701 goto drop_n_restore; 702 } 703 704 #endif 705 706 707 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, 708 struct msghdr *msg, size_t len) 709 { 710 struct sock *sk = sock->sk; 711 struct sockaddr_ll *saddr=(struct sockaddr_ll *)msg->msg_name; 712 struct sk_buff *skb; 713 struct net_device *dev; 714 unsigned short proto; 715 unsigned char *addr; 716 int ifindex, err, reserve = 0; 717 718 /* 719 * Get and verify the address. 720 */ 721 722 if (saddr == NULL) { 723 struct packet_sock *po = pkt_sk(sk); 724 725 ifindex = po->ifindex; 726 proto = po->num; 727 addr = NULL; 728 } else { 729 err = -EINVAL; 730 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 731 goto out; 732 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 733 goto out; 734 ifindex = saddr->sll_ifindex; 735 proto = saddr->sll_protocol; 736 addr = saddr->sll_addr; 737 } 738 739 740 dev = dev_get_by_index(ifindex); 741 err = -ENXIO; 742 if (dev == NULL) 743 goto out_unlock; 744 if (sock->type == SOCK_RAW) 745 reserve = dev->hard_header_len; 746 747 err = -EMSGSIZE; 748 if (len > dev->mtu+reserve) 749 goto out_unlock; 750 751 skb = sock_alloc_send_skb(sk, len + LL_RESERVED_SPACE(dev), 752 msg->msg_flags & MSG_DONTWAIT, &err); 753 if (skb==NULL) 754 goto out_unlock; 755 756 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 757 skb->nh.raw = skb->data; 758 759 if (dev->hard_header) { 760 int res; 761 err = -EINVAL; 762 res = dev->hard_header(skb, dev, ntohs(proto), addr, NULL, len); 763 if (sock->type != SOCK_DGRAM) { 764 skb->tail = skb->data; 765 skb->len = 0; 766 } else if (res < 0) 767 goto out_free; 768 } 769 770 /* Returns -EFAULT on error */ 771 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len); 772 if (err) 773 goto out_free; 774 775 skb->protocol = proto; 776 skb->dev = dev; 777 skb->priority = sk->sk_priority; 778 779 err = -ENETDOWN; 780 if (!(dev->flags & IFF_UP)) 781 goto out_free; 782 783 /* 784 * Now send it 785 */ 786 787 err = dev_queue_xmit(skb); 788 if (err > 0 && (err = net_xmit_errno(err)) != 0) 789 goto out_unlock; 790 791 dev_put(dev); 792 793 return(len); 794 795 out_free: 796 kfree_skb(skb); 797 out_unlock: 798 if (dev) 799 dev_put(dev); 800 out: 801 return err; 802 } 803 804 /* 805 * Close a PACKET socket. This is fairly simple. We immediately go 806 * to 'closed' state and remove our protocol entry in the device list. 807 */ 808 809 static int packet_release(struct socket *sock) 810 { 811 struct sock *sk = sock->sk; 812 struct packet_sock *po; 813 814 if (!sk) 815 return 0; 816 817 po = pkt_sk(sk); 818 819 write_lock_bh(&packet_sklist_lock); 820 sk_del_node_init(sk); 821 write_unlock_bh(&packet_sklist_lock); 822 823 /* 824 * Unhook packet receive handler. 825 */ 826 827 if (po->running) { 828 /* 829 * Remove the protocol hook 830 */ 831 dev_remove_pack(&po->prot_hook); 832 po->running = 0; 833 po->num = 0; 834 __sock_put(sk); 835 } 836 837 #ifdef CONFIG_PACKET_MULTICAST 838 packet_flush_mclist(sk); 839 #endif 840 841 #ifdef CONFIG_PACKET_MMAP 842 if (po->pg_vec) { 843 struct tpacket_req req; 844 memset(&req, 0, sizeof(req)); 845 packet_set_ring(sk, &req, 1); 846 } 847 #endif 848 849 /* 850 * Now the socket is dead. No more input will appear. 851 */ 852 853 sock_orphan(sk); 854 sock->sk = NULL; 855 856 /* Purge queues */ 857 858 skb_queue_purge(&sk->sk_receive_queue); 859 860 sock_put(sk); 861 return 0; 862 } 863 864 /* 865 * Attach a packet hook. 866 */ 867 868 static int packet_do_bind(struct sock *sk, struct net_device *dev, int protocol) 869 { 870 struct packet_sock *po = pkt_sk(sk); 871 /* 872 * Detach an existing hook if present. 873 */ 874 875 lock_sock(sk); 876 877 spin_lock(&po->bind_lock); 878 if (po->running) { 879 __sock_put(sk); 880 po->running = 0; 881 po->num = 0; 882 spin_unlock(&po->bind_lock); 883 dev_remove_pack(&po->prot_hook); 884 spin_lock(&po->bind_lock); 885 } 886 887 po->num = protocol; 888 po->prot_hook.type = protocol; 889 po->prot_hook.dev = dev; 890 891 po->ifindex = dev ? dev->ifindex : 0; 892 893 if (protocol == 0) 894 goto out_unlock; 895 896 if (dev) { 897 if (dev->flags&IFF_UP) { 898 dev_add_pack(&po->prot_hook); 899 sock_hold(sk); 900 po->running = 1; 901 } else { 902 sk->sk_err = ENETDOWN; 903 if (!sock_flag(sk, SOCK_DEAD)) 904 sk->sk_error_report(sk); 905 } 906 } else { 907 dev_add_pack(&po->prot_hook); 908 sock_hold(sk); 909 po->running = 1; 910 } 911 912 out_unlock: 913 spin_unlock(&po->bind_lock); 914 release_sock(sk); 915 return 0; 916 } 917 918 /* 919 * Bind a packet socket to a device 920 */ 921 922 #ifdef CONFIG_SOCK_PACKET 923 924 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, int addr_len) 925 { 926 struct sock *sk=sock->sk; 927 char name[15]; 928 struct net_device *dev; 929 int err = -ENODEV; 930 931 /* 932 * Check legality 933 */ 934 935 if (addr_len != sizeof(struct sockaddr)) 936 return -EINVAL; 937 strlcpy(name,uaddr->sa_data,sizeof(name)); 938 939 dev = dev_get_by_name(name); 940 if (dev) { 941 err = packet_do_bind(sk, dev, pkt_sk(sk)->num); 942 dev_put(dev); 943 } 944 return err; 945 } 946 #endif 947 948 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 949 { 950 struct sockaddr_ll *sll = (struct sockaddr_ll*)uaddr; 951 struct sock *sk=sock->sk; 952 struct net_device *dev = NULL; 953 int err; 954 955 956 /* 957 * Check legality 958 */ 959 960 if (addr_len < sizeof(struct sockaddr_ll)) 961 return -EINVAL; 962 if (sll->sll_family != AF_PACKET) 963 return -EINVAL; 964 965 if (sll->sll_ifindex) { 966 err = -ENODEV; 967 dev = dev_get_by_index(sll->sll_ifindex); 968 if (dev == NULL) 969 goto out; 970 } 971 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); 972 if (dev) 973 dev_put(dev); 974 975 out: 976 return err; 977 } 978 979 static struct proto packet_proto = { 980 .name = "PACKET", 981 .owner = THIS_MODULE, 982 .obj_size = sizeof(struct packet_sock), 983 }; 984 985 /* 986 * Create a packet of type SOCK_PACKET. 987 */ 988 989 static int packet_create(struct socket *sock, int protocol) 990 { 991 struct sock *sk; 992 struct packet_sock *po; 993 int err; 994 995 if (!capable(CAP_NET_RAW)) 996 return -EPERM; 997 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW 998 #ifdef CONFIG_SOCK_PACKET 999 && sock->type != SOCK_PACKET 1000 #endif 1001 ) 1002 return -ESOCKTNOSUPPORT; 1003 1004 sock->state = SS_UNCONNECTED; 1005 1006 err = -ENOBUFS; 1007 sk = sk_alloc(PF_PACKET, GFP_KERNEL, &packet_proto, 1); 1008 if (sk == NULL) 1009 goto out; 1010 1011 sock->ops = &packet_ops; 1012 #ifdef CONFIG_SOCK_PACKET 1013 if (sock->type == SOCK_PACKET) 1014 sock->ops = &packet_ops_spkt; 1015 #endif 1016 sock_init_data(sock, sk); 1017 1018 po = pkt_sk(sk); 1019 sk->sk_family = PF_PACKET; 1020 po->num = protocol; 1021 1022 sk->sk_destruct = packet_sock_destruct; 1023 atomic_inc(&packet_socks_nr); 1024 1025 /* 1026 * Attach a protocol block 1027 */ 1028 1029 spin_lock_init(&po->bind_lock); 1030 po->prot_hook.func = packet_rcv; 1031 #ifdef CONFIG_SOCK_PACKET 1032 if (sock->type == SOCK_PACKET) 1033 po->prot_hook.func = packet_rcv_spkt; 1034 #endif 1035 po->prot_hook.af_packet_priv = sk; 1036 1037 if (protocol) { 1038 po->prot_hook.type = protocol; 1039 dev_add_pack(&po->prot_hook); 1040 sock_hold(sk); 1041 po->running = 1; 1042 } 1043 1044 write_lock_bh(&packet_sklist_lock); 1045 sk_add_node(sk, &packet_sklist); 1046 write_unlock_bh(&packet_sklist_lock); 1047 return(0); 1048 out: 1049 return err; 1050 } 1051 1052 /* 1053 * Pull a packet from our receive queue and hand it to the user. 1054 * If necessary we block. 1055 */ 1056 1057 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, 1058 struct msghdr *msg, size_t len, int flags) 1059 { 1060 struct sock *sk = sock->sk; 1061 struct sk_buff *skb; 1062 int copied, err; 1063 struct sockaddr_ll *sll; 1064 1065 err = -EINVAL; 1066 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT)) 1067 goto out; 1068 1069 #if 0 1070 /* What error should we return now? EUNATTACH? */ 1071 if (pkt_sk(sk)->ifindex < 0) 1072 return -ENODEV; 1073 #endif 1074 1075 /* 1076 * Call the generic datagram receiver. This handles all sorts 1077 * of horrible races and re-entrancy so we can forget about it 1078 * in the protocol layers. 1079 * 1080 * Now it will return ENETDOWN, if device have just gone down, 1081 * but then it will block. 1082 */ 1083 1084 skb=skb_recv_datagram(sk,flags,flags&MSG_DONTWAIT,&err); 1085 1086 /* 1087 * An error occurred so return it. Because skb_recv_datagram() 1088 * handles the blocking we don't see and worry about blocking 1089 * retries. 1090 */ 1091 1092 if (skb == NULL) 1093 goto out; 1094 1095 /* 1096 * If the address length field is there to be filled in, we fill 1097 * it in now. 1098 */ 1099 1100 sll = (struct sockaddr_ll*)skb->cb; 1101 if (sock->type == SOCK_PACKET) 1102 msg->msg_namelen = sizeof(struct sockaddr_pkt); 1103 else 1104 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); 1105 1106 /* 1107 * You lose any data beyond the buffer you gave. If it worries a 1108 * user program they can ask the device for its MTU anyway. 1109 */ 1110 1111 copied = skb->len; 1112 if (copied > len) 1113 { 1114 copied=len; 1115 msg->msg_flags|=MSG_TRUNC; 1116 } 1117 1118 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 1119 if (err) 1120 goto out_free; 1121 1122 sock_recv_timestamp(msg, sk, skb); 1123 1124 if (msg->msg_name) 1125 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1126 1127 /* 1128 * Free or return the buffer as appropriate. Again this 1129 * hides all the races and re-entrancy issues from us. 1130 */ 1131 err = (flags&MSG_TRUNC) ? skb->len : copied; 1132 1133 out_free: 1134 skb_free_datagram(sk, skb); 1135 out: 1136 return err; 1137 } 1138 1139 #ifdef CONFIG_SOCK_PACKET 1140 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 1141 int *uaddr_len, int peer) 1142 { 1143 struct net_device *dev; 1144 struct sock *sk = sock->sk; 1145 1146 if (peer) 1147 return -EOPNOTSUPP; 1148 1149 uaddr->sa_family = AF_PACKET; 1150 dev = dev_get_by_index(pkt_sk(sk)->ifindex); 1151 if (dev) { 1152 strlcpy(uaddr->sa_data, dev->name, 15); 1153 dev_put(dev); 1154 } else 1155 memset(uaddr->sa_data, 0, 14); 1156 *uaddr_len = sizeof(*uaddr); 1157 1158 return 0; 1159 } 1160 #endif 1161 1162 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 1163 int *uaddr_len, int peer) 1164 { 1165 struct net_device *dev; 1166 struct sock *sk = sock->sk; 1167 struct packet_sock *po = pkt_sk(sk); 1168 struct sockaddr_ll *sll = (struct sockaddr_ll*)uaddr; 1169 1170 if (peer) 1171 return -EOPNOTSUPP; 1172 1173 sll->sll_family = AF_PACKET; 1174 sll->sll_ifindex = po->ifindex; 1175 sll->sll_protocol = po->num; 1176 dev = dev_get_by_index(po->ifindex); 1177 if (dev) { 1178 sll->sll_hatype = dev->type; 1179 sll->sll_halen = dev->addr_len; 1180 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 1181 dev_put(dev); 1182 } else { 1183 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 1184 sll->sll_halen = 0; 1185 } 1186 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 1187 1188 return 0; 1189 } 1190 1191 #ifdef CONFIG_PACKET_MULTICAST 1192 static void packet_dev_mc(struct net_device *dev, struct packet_mclist *i, int what) 1193 { 1194 switch (i->type) { 1195 case PACKET_MR_MULTICAST: 1196 if (what > 0) 1197 dev_mc_add(dev, i->addr, i->alen, 0); 1198 else 1199 dev_mc_delete(dev, i->addr, i->alen, 0); 1200 break; 1201 case PACKET_MR_PROMISC: 1202 dev_set_promiscuity(dev, what); 1203 break; 1204 case PACKET_MR_ALLMULTI: 1205 dev_set_allmulti(dev, what); 1206 break; 1207 default:; 1208 } 1209 } 1210 1211 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) 1212 { 1213 for ( ; i; i=i->next) { 1214 if (i->ifindex == dev->ifindex) 1215 packet_dev_mc(dev, i, what); 1216 } 1217 } 1218 1219 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 1220 { 1221 struct packet_sock *po = pkt_sk(sk); 1222 struct packet_mclist *ml, *i; 1223 struct net_device *dev; 1224 int err; 1225 1226 rtnl_lock(); 1227 1228 err = -ENODEV; 1229 dev = __dev_get_by_index(mreq->mr_ifindex); 1230 if (!dev) 1231 goto done; 1232 1233 err = -EINVAL; 1234 if (mreq->mr_alen > dev->addr_len) 1235 goto done; 1236 1237 err = -ENOBUFS; 1238 i = kmalloc(sizeof(*i), GFP_KERNEL); 1239 if (i == NULL) 1240 goto done; 1241 1242 err = 0; 1243 for (ml = po->mclist; ml; ml = ml->next) { 1244 if (ml->ifindex == mreq->mr_ifindex && 1245 ml->type == mreq->mr_type && 1246 ml->alen == mreq->mr_alen && 1247 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 1248 ml->count++; 1249 /* Free the new element ... */ 1250 kfree(i); 1251 goto done; 1252 } 1253 } 1254 1255 i->type = mreq->mr_type; 1256 i->ifindex = mreq->mr_ifindex; 1257 i->alen = mreq->mr_alen; 1258 memcpy(i->addr, mreq->mr_address, i->alen); 1259 i->count = 1; 1260 i->next = po->mclist; 1261 po->mclist = i; 1262 packet_dev_mc(dev, i, +1); 1263 1264 done: 1265 rtnl_unlock(); 1266 return err; 1267 } 1268 1269 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 1270 { 1271 struct packet_mclist *ml, **mlp; 1272 1273 rtnl_lock(); 1274 1275 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 1276 if (ml->ifindex == mreq->mr_ifindex && 1277 ml->type == mreq->mr_type && 1278 ml->alen == mreq->mr_alen && 1279 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 1280 if (--ml->count == 0) { 1281 struct net_device *dev; 1282 *mlp = ml->next; 1283 dev = dev_get_by_index(ml->ifindex); 1284 if (dev) { 1285 packet_dev_mc(dev, ml, -1); 1286 dev_put(dev); 1287 } 1288 kfree(ml); 1289 } 1290 rtnl_unlock(); 1291 return 0; 1292 } 1293 } 1294 rtnl_unlock(); 1295 return -EADDRNOTAVAIL; 1296 } 1297 1298 static void packet_flush_mclist(struct sock *sk) 1299 { 1300 struct packet_sock *po = pkt_sk(sk); 1301 struct packet_mclist *ml; 1302 1303 if (!po->mclist) 1304 return; 1305 1306 rtnl_lock(); 1307 while ((ml = po->mclist) != NULL) { 1308 struct net_device *dev; 1309 1310 po->mclist = ml->next; 1311 if ((dev = dev_get_by_index(ml->ifindex)) != NULL) { 1312 packet_dev_mc(dev, ml, -1); 1313 dev_put(dev); 1314 } 1315 kfree(ml); 1316 } 1317 rtnl_unlock(); 1318 } 1319 #endif 1320 1321 static int 1322 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen) 1323 { 1324 struct sock *sk = sock->sk; 1325 int ret; 1326 1327 if (level != SOL_PACKET) 1328 return -ENOPROTOOPT; 1329 1330 switch(optname) { 1331 #ifdef CONFIG_PACKET_MULTICAST 1332 case PACKET_ADD_MEMBERSHIP: 1333 case PACKET_DROP_MEMBERSHIP: 1334 { 1335 struct packet_mreq_max mreq; 1336 int len = optlen; 1337 memset(&mreq, 0, sizeof(mreq)); 1338 if (len < sizeof(struct packet_mreq)) 1339 return -EINVAL; 1340 if (len > sizeof(mreq)) 1341 len = sizeof(mreq); 1342 if (copy_from_user(&mreq,optval,len)) 1343 return -EFAULT; 1344 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 1345 return -EINVAL; 1346 if (optname == PACKET_ADD_MEMBERSHIP) 1347 ret = packet_mc_add(sk, &mreq); 1348 else 1349 ret = packet_mc_drop(sk, &mreq); 1350 return ret; 1351 } 1352 #endif 1353 #ifdef CONFIG_PACKET_MMAP 1354 case PACKET_RX_RING: 1355 { 1356 struct tpacket_req req; 1357 1358 if (optlen<sizeof(req)) 1359 return -EINVAL; 1360 if (copy_from_user(&req,optval,sizeof(req))) 1361 return -EFAULT; 1362 return packet_set_ring(sk, &req, 0); 1363 } 1364 case PACKET_COPY_THRESH: 1365 { 1366 int val; 1367 1368 if (optlen!=sizeof(val)) 1369 return -EINVAL; 1370 if (copy_from_user(&val,optval,sizeof(val))) 1371 return -EFAULT; 1372 1373 pkt_sk(sk)->copy_thresh = val; 1374 return 0; 1375 } 1376 #endif 1377 default: 1378 return -ENOPROTOOPT; 1379 } 1380 } 1381 1382 static int packet_getsockopt(struct socket *sock, int level, int optname, 1383 char __user *optval, int __user *optlen) 1384 { 1385 int len; 1386 struct sock *sk = sock->sk; 1387 struct packet_sock *po = pkt_sk(sk); 1388 1389 if (level != SOL_PACKET) 1390 return -ENOPROTOOPT; 1391 1392 if (get_user(len, optlen)) 1393 return -EFAULT; 1394 1395 if (len < 0) 1396 return -EINVAL; 1397 1398 switch(optname) { 1399 case PACKET_STATISTICS: 1400 { 1401 struct tpacket_stats st; 1402 1403 if (len > sizeof(struct tpacket_stats)) 1404 len = sizeof(struct tpacket_stats); 1405 spin_lock_bh(&sk->sk_receive_queue.lock); 1406 st = po->stats; 1407 memset(&po->stats, 0, sizeof(st)); 1408 spin_unlock_bh(&sk->sk_receive_queue.lock); 1409 st.tp_packets += st.tp_drops; 1410 1411 if (copy_to_user(optval, &st, len)) 1412 return -EFAULT; 1413 break; 1414 } 1415 default: 1416 return -ENOPROTOOPT; 1417 } 1418 1419 if (put_user(len, optlen)) 1420 return -EFAULT; 1421 return 0; 1422 } 1423 1424 1425 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) 1426 { 1427 struct sock *sk; 1428 struct hlist_node *node; 1429 struct net_device *dev = (struct net_device*)data; 1430 1431 read_lock(&packet_sklist_lock); 1432 sk_for_each(sk, node, &packet_sklist) { 1433 struct packet_sock *po = pkt_sk(sk); 1434 1435 switch (msg) { 1436 case NETDEV_UNREGISTER: 1437 #ifdef CONFIG_PACKET_MULTICAST 1438 if (po->mclist) 1439 packet_dev_mclist(dev, po->mclist, -1); 1440 // fallthrough 1441 #endif 1442 case NETDEV_DOWN: 1443 if (dev->ifindex == po->ifindex) { 1444 spin_lock(&po->bind_lock); 1445 if (po->running) { 1446 __dev_remove_pack(&po->prot_hook); 1447 __sock_put(sk); 1448 po->running = 0; 1449 sk->sk_err = ENETDOWN; 1450 if (!sock_flag(sk, SOCK_DEAD)) 1451 sk->sk_error_report(sk); 1452 } 1453 if (msg == NETDEV_UNREGISTER) { 1454 po->ifindex = -1; 1455 po->prot_hook.dev = NULL; 1456 } 1457 spin_unlock(&po->bind_lock); 1458 } 1459 break; 1460 case NETDEV_UP: 1461 spin_lock(&po->bind_lock); 1462 if (dev->ifindex == po->ifindex && po->num && 1463 !po->running) { 1464 dev_add_pack(&po->prot_hook); 1465 sock_hold(sk); 1466 po->running = 1; 1467 } 1468 spin_unlock(&po->bind_lock); 1469 break; 1470 } 1471 } 1472 read_unlock(&packet_sklist_lock); 1473 return NOTIFY_DONE; 1474 } 1475 1476 1477 static int packet_ioctl(struct socket *sock, unsigned int cmd, 1478 unsigned long arg) 1479 { 1480 struct sock *sk = sock->sk; 1481 1482 switch(cmd) { 1483 case SIOCOUTQ: 1484 { 1485 int amount = atomic_read(&sk->sk_wmem_alloc); 1486 return put_user(amount, (int __user *)arg); 1487 } 1488 case SIOCINQ: 1489 { 1490 struct sk_buff *skb; 1491 int amount = 0; 1492 1493 spin_lock_bh(&sk->sk_receive_queue.lock); 1494 skb = skb_peek(&sk->sk_receive_queue); 1495 if (skb) 1496 amount = skb->len; 1497 spin_unlock_bh(&sk->sk_receive_queue.lock); 1498 return put_user(amount, (int __user *)arg); 1499 } 1500 case SIOCGSTAMP: 1501 return sock_get_timestamp(sk, (struct timeval __user *)arg); 1502 1503 #ifdef CONFIG_INET 1504 case SIOCADDRT: 1505 case SIOCDELRT: 1506 case SIOCDARP: 1507 case SIOCGARP: 1508 case SIOCSARP: 1509 case SIOCGIFADDR: 1510 case SIOCSIFADDR: 1511 case SIOCGIFBRDADDR: 1512 case SIOCSIFBRDADDR: 1513 case SIOCGIFNETMASK: 1514 case SIOCSIFNETMASK: 1515 case SIOCGIFDSTADDR: 1516 case SIOCSIFDSTADDR: 1517 case SIOCSIFFLAGS: 1518 return inet_dgram_ops.ioctl(sock, cmd, arg); 1519 #endif 1520 1521 default: 1522 return -ENOIOCTLCMD; 1523 } 1524 return 0; 1525 } 1526 1527 #ifndef CONFIG_PACKET_MMAP 1528 #define packet_mmap sock_no_mmap 1529 #define packet_poll datagram_poll 1530 #else 1531 1532 static unsigned int packet_poll(struct file * file, struct socket *sock, 1533 poll_table *wait) 1534 { 1535 struct sock *sk = sock->sk; 1536 struct packet_sock *po = pkt_sk(sk); 1537 unsigned int mask = datagram_poll(file, sock, wait); 1538 1539 spin_lock_bh(&sk->sk_receive_queue.lock); 1540 if (po->pg_vec) { 1541 unsigned last = po->head ? po->head-1 : po->frame_max; 1542 struct tpacket_hdr *h; 1543 1544 h = (struct tpacket_hdr *)packet_lookup_frame(po, last); 1545 1546 if (h->tp_status) 1547 mask |= POLLIN | POLLRDNORM; 1548 } 1549 spin_unlock_bh(&sk->sk_receive_queue.lock); 1550 return mask; 1551 } 1552 1553 1554 /* Dirty? Well, I still did not learn better way to account 1555 * for user mmaps. 1556 */ 1557 1558 static void packet_mm_open(struct vm_area_struct *vma) 1559 { 1560 struct file *file = vma->vm_file; 1561 struct socket * sock = file->private_data; 1562 struct sock *sk = sock->sk; 1563 1564 if (sk) 1565 atomic_inc(&pkt_sk(sk)->mapped); 1566 } 1567 1568 static void packet_mm_close(struct vm_area_struct *vma) 1569 { 1570 struct file *file = vma->vm_file; 1571 struct socket * sock = file->private_data; 1572 struct sock *sk = sock->sk; 1573 1574 if (sk) 1575 atomic_dec(&pkt_sk(sk)->mapped); 1576 } 1577 1578 static struct vm_operations_struct packet_mmap_ops = { 1579 .open = packet_mm_open, 1580 .close =packet_mm_close, 1581 }; 1582 1583 static inline struct page *pg_vec_endpage(char *one_pg_vec, unsigned int order) 1584 { 1585 return virt_to_page(one_pg_vec + (PAGE_SIZE << order) - 1); 1586 } 1587 1588 static void free_pg_vec(char **pg_vec, unsigned int order, unsigned int len) 1589 { 1590 int i; 1591 1592 for (i = 0; i < len; i++) { 1593 if (likely(pg_vec[i])) 1594 free_pages((unsigned long) pg_vec[i], order); 1595 } 1596 kfree(pg_vec); 1597 } 1598 1599 static inline char *alloc_one_pg_vec_page(unsigned long order) 1600 { 1601 return (char *) __get_free_pages(GFP_KERNEL | __GFP_COMP | __GFP_ZERO, 1602 order); 1603 } 1604 1605 static char **alloc_pg_vec(struct tpacket_req *req, int order) 1606 { 1607 unsigned int block_nr = req->tp_block_nr; 1608 char **pg_vec; 1609 int i; 1610 1611 pg_vec = kzalloc(block_nr * sizeof(char *), GFP_KERNEL); 1612 if (unlikely(!pg_vec)) 1613 goto out; 1614 1615 for (i = 0; i < block_nr; i++) { 1616 pg_vec[i] = alloc_one_pg_vec_page(order); 1617 if (unlikely(!pg_vec[i])) 1618 goto out_free_pgvec; 1619 } 1620 1621 out: 1622 return pg_vec; 1623 1624 out_free_pgvec: 1625 free_pg_vec(pg_vec, order, block_nr); 1626 pg_vec = NULL; 1627 goto out; 1628 } 1629 1630 static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing) 1631 { 1632 char **pg_vec = NULL; 1633 struct packet_sock *po = pkt_sk(sk); 1634 int was_running, num, order = 0; 1635 int err = 0; 1636 1637 if (req->tp_block_nr) { 1638 int i, l; 1639 1640 /* Sanity tests and some calculations */ 1641 1642 if (unlikely(po->pg_vec)) 1643 return -EBUSY; 1644 1645 if (unlikely((int)req->tp_block_size <= 0)) 1646 return -EINVAL; 1647 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) 1648 return -EINVAL; 1649 if (unlikely(req->tp_frame_size < TPACKET_HDRLEN)) 1650 return -EINVAL; 1651 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 1652 return -EINVAL; 1653 1654 po->frames_per_block = req->tp_block_size/req->tp_frame_size; 1655 if (unlikely(po->frames_per_block <= 0)) 1656 return -EINVAL; 1657 if (unlikely((po->frames_per_block * req->tp_block_nr) != 1658 req->tp_frame_nr)) 1659 return -EINVAL; 1660 1661 err = -ENOMEM; 1662 order = get_order(req->tp_block_size); 1663 pg_vec = alloc_pg_vec(req, order); 1664 if (unlikely(!pg_vec)) 1665 goto out; 1666 1667 l = 0; 1668 for (i = 0; i < req->tp_block_nr; i++) { 1669 char *ptr = pg_vec[i]; 1670 struct tpacket_hdr *header; 1671 int k; 1672 1673 for (k = 0; k < po->frames_per_block; k++) { 1674 header = (struct tpacket_hdr *) ptr; 1675 header->tp_status = TP_STATUS_KERNEL; 1676 ptr += req->tp_frame_size; 1677 } 1678 } 1679 /* Done */ 1680 } else { 1681 if (unlikely(req->tp_frame_nr)) 1682 return -EINVAL; 1683 } 1684 1685 lock_sock(sk); 1686 1687 /* Detach socket from network */ 1688 spin_lock(&po->bind_lock); 1689 was_running = po->running; 1690 num = po->num; 1691 if (was_running) { 1692 __dev_remove_pack(&po->prot_hook); 1693 po->num = 0; 1694 po->running = 0; 1695 __sock_put(sk); 1696 } 1697 spin_unlock(&po->bind_lock); 1698 1699 synchronize_net(); 1700 1701 err = -EBUSY; 1702 if (closing || atomic_read(&po->mapped) == 0) { 1703 err = 0; 1704 #define XC(a, b) ({ __typeof__ ((a)) __t; __t = (a); (a) = (b); __t; }) 1705 1706 spin_lock_bh(&sk->sk_receive_queue.lock); 1707 pg_vec = XC(po->pg_vec, pg_vec); 1708 po->frame_max = (req->tp_frame_nr - 1); 1709 po->head = 0; 1710 po->frame_size = req->tp_frame_size; 1711 spin_unlock_bh(&sk->sk_receive_queue.lock); 1712 1713 order = XC(po->pg_vec_order, order); 1714 req->tp_block_nr = XC(po->pg_vec_len, req->tp_block_nr); 1715 1716 po->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 1717 po->prot_hook.func = po->pg_vec ? tpacket_rcv : packet_rcv; 1718 skb_queue_purge(&sk->sk_receive_queue); 1719 #undef XC 1720 if (atomic_read(&po->mapped)) 1721 printk(KERN_DEBUG "packet_mmap: vma is busy: %d\n", atomic_read(&po->mapped)); 1722 } 1723 1724 spin_lock(&po->bind_lock); 1725 if (was_running && !po->running) { 1726 sock_hold(sk); 1727 po->running = 1; 1728 po->num = num; 1729 dev_add_pack(&po->prot_hook); 1730 } 1731 spin_unlock(&po->bind_lock); 1732 1733 release_sock(sk); 1734 1735 if (pg_vec) 1736 free_pg_vec(pg_vec, order, req->tp_block_nr); 1737 out: 1738 return err; 1739 } 1740 1741 static int packet_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma) 1742 { 1743 struct sock *sk = sock->sk; 1744 struct packet_sock *po = pkt_sk(sk); 1745 unsigned long size; 1746 unsigned long start; 1747 int err = -EINVAL; 1748 int i; 1749 1750 if (vma->vm_pgoff) 1751 return -EINVAL; 1752 1753 size = vma->vm_end - vma->vm_start; 1754 1755 lock_sock(sk); 1756 if (po->pg_vec == NULL) 1757 goto out; 1758 if (size != po->pg_vec_len*po->pg_vec_pages*PAGE_SIZE) 1759 goto out; 1760 1761 start = vma->vm_start; 1762 for (i = 0; i < po->pg_vec_len; i++) { 1763 struct page *page = virt_to_page(po->pg_vec[i]); 1764 int pg_num; 1765 1766 for (pg_num = 0; pg_num < po->pg_vec_pages; pg_num++, page++) { 1767 err = vm_insert_page(vma, start, page); 1768 if (unlikely(err)) 1769 goto out; 1770 start += PAGE_SIZE; 1771 } 1772 } 1773 atomic_inc(&po->mapped); 1774 vma->vm_ops = &packet_mmap_ops; 1775 err = 0; 1776 1777 out: 1778 release_sock(sk); 1779 return err; 1780 } 1781 #endif 1782 1783 1784 #ifdef CONFIG_SOCK_PACKET 1785 static const struct proto_ops packet_ops_spkt = { 1786 .family = PF_PACKET, 1787 .owner = THIS_MODULE, 1788 .release = packet_release, 1789 .bind = packet_bind_spkt, 1790 .connect = sock_no_connect, 1791 .socketpair = sock_no_socketpair, 1792 .accept = sock_no_accept, 1793 .getname = packet_getname_spkt, 1794 .poll = datagram_poll, 1795 .ioctl = packet_ioctl, 1796 .listen = sock_no_listen, 1797 .shutdown = sock_no_shutdown, 1798 .setsockopt = sock_no_setsockopt, 1799 .getsockopt = sock_no_getsockopt, 1800 .sendmsg = packet_sendmsg_spkt, 1801 .recvmsg = packet_recvmsg, 1802 .mmap = sock_no_mmap, 1803 .sendpage = sock_no_sendpage, 1804 }; 1805 #endif 1806 1807 static const struct proto_ops packet_ops = { 1808 .family = PF_PACKET, 1809 .owner = THIS_MODULE, 1810 .release = packet_release, 1811 .bind = packet_bind, 1812 .connect = sock_no_connect, 1813 .socketpair = sock_no_socketpair, 1814 .accept = sock_no_accept, 1815 .getname = packet_getname, 1816 .poll = packet_poll, 1817 .ioctl = packet_ioctl, 1818 .listen = sock_no_listen, 1819 .shutdown = sock_no_shutdown, 1820 .setsockopt = packet_setsockopt, 1821 .getsockopt = packet_getsockopt, 1822 .sendmsg = packet_sendmsg, 1823 .recvmsg = packet_recvmsg, 1824 .mmap = packet_mmap, 1825 .sendpage = sock_no_sendpage, 1826 }; 1827 1828 static struct net_proto_family packet_family_ops = { 1829 .family = PF_PACKET, 1830 .create = packet_create, 1831 .owner = THIS_MODULE, 1832 }; 1833 1834 static struct notifier_block packet_netdev_notifier = { 1835 .notifier_call =packet_notifier, 1836 }; 1837 1838 #ifdef CONFIG_PROC_FS 1839 static inline struct sock *packet_seq_idx(loff_t off) 1840 { 1841 struct sock *s; 1842 struct hlist_node *node; 1843 1844 sk_for_each(s, node, &packet_sklist) { 1845 if (!off--) 1846 return s; 1847 } 1848 return NULL; 1849 } 1850 1851 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 1852 { 1853 read_lock(&packet_sklist_lock); 1854 return *pos ? packet_seq_idx(*pos - 1) : SEQ_START_TOKEN; 1855 } 1856 1857 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1858 { 1859 ++*pos; 1860 return (v == SEQ_START_TOKEN) 1861 ? sk_head(&packet_sklist) 1862 : sk_next((struct sock*)v) ; 1863 } 1864 1865 static void packet_seq_stop(struct seq_file *seq, void *v) 1866 { 1867 read_unlock(&packet_sklist_lock); 1868 } 1869 1870 static int packet_seq_show(struct seq_file *seq, void *v) 1871 { 1872 if (v == SEQ_START_TOKEN) 1873 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 1874 else { 1875 struct sock *s = v; 1876 const struct packet_sock *po = pkt_sk(s); 1877 1878 seq_printf(seq, 1879 "%p %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 1880 s, 1881 atomic_read(&s->sk_refcnt), 1882 s->sk_type, 1883 ntohs(po->num), 1884 po->ifindex, 1885 po->running, 1886 atomic_read(&s->sk_rmem_alloc), 1887 sock_i_uid(s), 1888 sock_i_ino(s) ); 1889 } 1890 1891 return 0; 1892 } 1893 1894 static struct seq_operations packet_seq_ops = { 1895 .start = packet_seq_start, 1896 .next = packet_seq_next, 1897 .stop = packet_seq_stop, 1898 .show = packet_seq_show, 1899 }; 1900 1901 static int packet_seq_open(struct inode *inode, struct file *file) 1902 { 1903 return seq_open(file, &packet_seq_ops); 1904 } 1905 1906 static struct file_operations packet_seq_fops = { 1907 .owner = THIS_MODULE, 1908 .open = packet_seq_open, 1909 .read = seq_read, 1910 .llseek = seq_lseek, 1911 .release = seq_release, 1912 }; 1913 1914 #endif 1915 1916 static void __exit packet_exit(void) 1917 { 1918 proc_net_remove("packet"); 1919 unregister_netdevice_notifier(&packet_netdev_notifier); 1920 sock_unregister(PF_PACKET); 1921 proto_unregister(&packet_proto); 1922 } 1923 1924 static int __init packet_init(void) 1925 { 1926 int rc = proto_register(&packet_proto, 0); 1927 1928 if (rc != 0) 1929 goto out; 1930 1931 sock_register(&packet_family_ops); 1932 register_netdevice_notifier(&packet_netdev_notifier); 1933 proc_net_fops_create("packet", 0, &packet_seq_fops); 1934 out: 1935 return rc; 1936 } 1937 1938 module_init(packet_init); 1939 module_exit(packet_exit); 1940 MODULE_LICENSE("GPL"); 1941 MODULE_ALIAS_NETPROTO(PF_PACKET); 1942