1 /* 2 * raw.c - Raw sockets for protocol family CAN 3 * 4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of Volkswagen nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * Alternatively, provided that this notice is retained in full, this 20 * software may be distributed under the terms of the GNU General 21 * Public License ("GPL") version 2, in which case the provisions of the 22 * GPL apply INSTEAD OF those given above. 23 * 24 * The provided data structures and external interfaces from this code 25 * are not restricted to be used by modules with a GPL compatible license. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 38 * DAMAGE. 39 * 40 * Send feedback to <socketcan-users@lists.berlios.de> 41 * 42 */ 43 44 #include <linux/module.h> 45 #include <linux/init.h> 46 #include <linux/uio.h> 47 #include <linux/net.h> 48 #include <linux/slab.h> 49 #include <linux/netdevice.h> 50 #include <linux/socket.h> 51 #include <linux/if_arp.h> 52 #include <linux/skbuff.h> 53 #include <linux/can.h> 54 #include <linux/can/core.h> 55 #include <linux/can/raw.h> 56 #include <net/sock.h> 57 #include <net/net_namespace.h> 58 59 #define CAN_RAW_VERSION CAN_VERSION 60 static __initdata const char banner[] = 61 KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n"; 62 63 MODULE_DESCRIPTION("PF_CAN raw protocol"); 64 MODULE_LICENSE("Dual BSD/GPL"); 65 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>"); 66 MODULE_ALIAS("can-proto-1"); 67 68 #define MASK_ALL 0 69 70 /* 71 * A raw socket has a list of can_filters attached to it, each receiving 72 * the CAN frames matching that filter. If the filter list is empty, 73 * no CAN frames will be received by the socket. The default after 74 * opening the socket, is to have one filter which receives all frames. 75 * The filter list is allocated dynamically with the exception of the 76 * list containing only one item. This common case is optimized by 77 * storing the single filter in dfilter, to avoid using dynamic memory. 78 */ 79 80 struct raw_sock { 81 struct sock sk; 82 int bound; 83 int ifindex; 84 struct notifier_block notifier; 85 int loopback; 86 int recv_own_msgs; 87 int count; /* number of active filters */ 88 struct can_filter dfilter; /* default/single filter */ 89 struct can_filter *filter; /* pointer to filter(s) */ 90 can_err_mask_t err_mask; 91 }; 92 93 static inline struct raw_sock *raw_sk(const struct sock *sk) 94 { 95 return (struct raw_sock *)sk; 96 } 97 98 static void raw_rcv(struct sk_buff *skb, void *data) 99 { 100 struct sock *sk = (struct sock *)data; 101 struct raw_sock *ro = raw_sk(sk); 102 struct sockaddr_can *addr; 103 104 /* check the received tx sock reference */ 105 if (!ro->recv_own_msgs && skb->sk == sk) 106 return; 107 108 /* clone the given skb to be able to enqueue it into the rcv queue */ 109 skb = skb_clone(skb, GFP_ATOMIC); 110 if (!skb) 111 return; 112 113 /* 114 * Put the datagram to the queue so that raw_recvmsg() can 115 * get it from there. We need to pass the interface index to 116 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 117 * containing the interface index. 118 */ 119 120 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can)); 121 addr = (struct sockaddr_can *)skb->cb; 122 memset(addr, 0, sizeof(*addr)); 123 addr->can_family = AF_CAN; 124 addr->can_ifindex = skb->dev->ifindex; 125 126 if (sock_queue_rcv_skb(sk, skb) < 0) 127 kfree_skb(skb); 128 } 129 130 static int raw_enable_filters(struct net_device *dev, struct sock *sk, 131 struct can_filter *filter, int count) 132 { 133 int err = 0; 134 int i; 135 136 for (i = 0; i < count; i++) { 137 err = can_rx_register(dev, filter[i].can_id, 138 filter[i].can_mask, 139 raw_rcv, sk, "raw"); 140 if (err) { 141 /* clean up successfully registered filters */ 142 while (--i >= 0) 143 can_rx_unregister(dev, filter[i].can_id, 144 filter[i].can_mask, 145 raw_rcv, sk); 146 break; 147 } 148 } 149 150 return err; 151 } 152 153 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk, 154 can_err_mask_t err_mask) 155 { 156 int err = 0; 157 158 if (err_mask) 159 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG, 160 raw_rcv, sk, "raw"); 161 162 return err; 163 } 164 165 static void raw_disable_filters(struct net_device *dev, struct sock *sk, 166 struct can_filter *filter, int count) 167 { 168 int i; 169 170 for (i = 0; i < count; i++) 171 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask, 172 raw_rcv, sk); 173 } 174 175 static inline void raw_disable_errfilter(struct net_device *dev, 176 struct sock *sk, 177 can_err_mask_t err_mask) 178 179 { 180 if (err_mask) 181 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG, 182 raw_rcv, sk); 183 } 184 185 static inline void raw_disable_allfilters(struct net_device *dev, 186 struct sock *sk) 187 { 188 struct raw_sock *ro = raw_sk(sk); 189 190 raw_disable_filters(dev, sk, ro->filter, ro->count); 191 raw_disable_errfilter(dev, sk, ro->err_mask); 192 } 193 194 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk) 195 { 196 struct raw_sock *ro = raw_sk(sk); 197 int err; 198 199 err = raw_enable_filters(dev, sk, ro->filter, ro->count); 200 if (!err) { 201 err = raw_enable_errfilter(dev, sk, ro->err_mask); 202 if (err) 203 raw_disable_filters(dev, sk, ro->filter, ro->count); 204 } 205 206 return err; 207 } 208 209 static int raw_notifier(struct notifier_block *nb, 210 unsigned long msg, void *data) 211 { 212 struct net_device *dev = (struct net_device *)data; 213 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier); 214 struct sock *sk = &ro->sk; 215 216 if (!net_eq(dev_net(dev), &init_net)) 217 return NOTIFY_DONE; 218 219 if (dev->type != ARPHRD_CAN) 220 return NOTIFY_DONE; 221 222 if (ro->ifindex != dev->ifindex) 223 return NOTIFY_DONE; 224 225 switch (msg) { 226 227 case NETDEV_UNREGISTER: 228 lock_sock(sk); 229 /* remove current filters & unregister */ 230 if (ro->bound) 231 raw_disable_allfilters(dev, sk); 232 233 if (ro->count > 1) 234 kfree(ro->filter); 235 236 ro->ifindex = 0; 237 ro->bound = 0; 238 ro->count = 0; 239 release_sock(sk); 240 241 sk->sk_err = ENODEV; 242 if (!sock_flag(sk, SOCK_DEAD)) 243 sk->sk_error_report(sk); 244 break; 245 246 case NETDEV_DOWN: 247 sk->sk_err = ENETDOWN; 248 if (!sock_flag(sk, SOCK_DEAD)) 249 sk->sk_error_report(sk); 250 break; 251 } 252 253 return NOTIFY_DONE; 254 } 255 256 static int raw_init(struct sock *sk) 257 { 258 struct raw_sock *ro = raw_sk(sk); 259 260 ro->bound = 0; 261 ro->ifindex = 0; 262 263 /* set default filter to single entry dfilter */ 264 ro->dfilter.can_id = 0; 265 ro->dfilter.can_mask = MASK_ALL; 266 ro->filter = &ro->dfilter; 267 ro->count = 1; 268 269 /* set default loopback behaviour */ 270 ro->loopback = 1; 271 ro->recv_own_msgs = 0; 272 273 /* set notifier */ 274 ro->notifier.notifier_call = raw_notifier; 275 276 register_netdevice_notifier(&ro->notifier); 277 278 return 0; 279 } 280 281 static int raw_release(struct socket *sock) 282 { 283 struct sock *sk = sock->sk; 284 struct raw_sock *ro = raw_sk(sk); 285 286 unregister_netdevice_notifier(&ro->notifier); 287 288 lock_sock(sk); 289 290 /* remove current filters & unregister */ 291 if (ro->bound) { 292 if (ro->ifindex) { 293 struct net_device *dev; 294 295 dev = dev_get_by_index(&init_net, ro->ifindex); 296 if (dev) { 297 raw_disable_allfilters(dev, sk); 298 dev_put(dev); 299 } 300 } else 301 raw_disable_allfilters(NULL, sk); 302 } 303 304 if (ro->count > 1) 305 kfree(ro->filter); 306 307 ro->ifindex = 0; 308 ro->bound = 0; 309 ro->count = 0; 310 311 sock_orphan(sk); 312 sock->sk = NULL; 313 314 release_sock(sk); 315 sock_put(sk); 316 317 return 0; 318 } 319 320 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 321 { 322 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 323 struct sock *sk = sock->sk; 324 struct raw_sock *ro = raw_sk(sk); 325 int ifindex; 326 int err = 0; 327 int notify_enetdown = 0; 328 329 if (len < sizeof(*addr)) 330 return -EINVAL; 331 332 lock_sock(sk); 333 334 if (ro->bound && addr->can_ifindex == ro->ifindex) 335 goto out; 336 337 if (addr->can_ifindex) { 338 struct net_device *dev; 339 340 dev = dev_get_by_index(&init_net, addr->can_ifindex); 341 if (!dev) { 342 err = -ENODEV; 343 goto out; 344 } 345 if (dev->type != ARPHRD_CAN) { 346 dev_put(dev); 347 err = -ENODEV; 348 goto out; 349 } 350 if (!(dev->flags & IFF_UP)) 351 notify_enetdown = 1; 352 353 ifindex = dev->ifindex; 354 355 /* filters set by default/setsockopt */ 356 err = raw_enable_allfilters(dev, sk); 357 dev_put(dev); 358 } else { 359 ifindex = 0; 360 361 /* filters set by default/setsockopt */ 362 err = raw_enable_allfilters(NULL, sk); 363 } 364 365 if (!err) { 366 if (ro->bound) { 367 /* unregister old filters */ 368 if (ro->ifindex) { 369 struct net_device *dev; 370 371 dev = dev_get_by_index(&init_net, ro->ifindex); 372 if (dev) { 373 raw_disable_allfilters(dev, sk); 374 dev_put(dev); 375 } 376 } else 377 raw_disable_allfilters(NULL, sk); 378 } 379 ro->ifindex = ifindex; 380 ro->bound = 1; 381 } 382 383 out: 384 release_sock(sk); 385 386 if (notify_enetdown) { 387 sk->sk_err = ENETDOWN; 388 if (!sock_flag(sk, SOCK_DEAD)) 389 sk->sk_error_report(sk); 390 } 391 392 return err; 393 } 394 395 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 396 int *len, int peer) 397 { 398 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 399 struct sock *sk = sock->sk; 400 struct raw_sock *ro = raw_sk(sk); 401 402 if (peer) 403 return -EOPNOTSUPP; 404 405 memset(addr, 0, sizeof(*addr)); 406 addr->can_family = AF_CAN; 407 addr->can_ifindex = ro->ifindex; 408 409 *len = sizeof(*addr); 410 411 return 0; 412 } 413 414 static int raw_setsockopt(struct socket *sock, int level, int optname, 415 char __user *optval, unsigned int optlen) 416 { 417 struct sock *sk = sock->sk; 418 struct raw_sock *ro = raw_sk(sk); 419 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 420 struct can_filter sfilter; /* single filter */ 421 struct net_device *dev = NULL; 422 can_err_mask_t err_mask = 0; 423 int count = 0; 424 int err = 0; 425 426 if (level != SOL_CAN_RAW) 427 return -EINVAL; 428 429 switch (optname) { 430 431 case CAN_RAW_FILTER: 432 if (optlen % sizeof(struct can_filter) != 0) 433 return -EINVAL; 434 435 count = optlen / sizeof(struct can_filter); 436 437 if (count > 1) { 438 /* filter does not fit into dfilter => alloc space */ 439 filter = kmalloc(optlen, GFP_KERNEL); 440 if (!filter) 441 return -ENOMEM; 442 443 if (copy_from_user(filter, optval, optlen)) { 444 kfree(filter); 445 return -EFAULT; 446 } 447 } else if (count == 1) { 448 if (copy_from_user(&sfilter, optval, sizeof(sfilter))) 449 return -EFAULT; 450 } 451 452 lock_sock(sk); 453 454 if (ro->bound && ro->ifindex) 455 dev = dev_get_by_index(&init_net, ro->ifindex); 456 457 if (ro->bound) { 458 /* (try to) register the new filters */ 459 if (count == 1) 460 err = raw_enable_filters(dev, sk, &sfilter, 1); 461 else 462 err = raw_enable_filters(dev, sk, filter, 463 count); 464 if (err) { 465 if (count > 1) 466 kfree(filter); 467 goto out_fil; 468 } 469 470 /* remove old filter registrations */ 471 raw_disable_filters(dev, sk, ro->filter, ro->count); 472 } 473 474 /* remove old filter space */ 475 if (ro->count > 1) 476 kfree(ro->filter); 477 478 /* link new filters to the socket */ 479 if (count == 1) { 480 /* copy filter data for single filter */ 481 ro->dfilter = sfilter; 482 filter = &ro->dfilter; 483 } 484 ro->filter = filter; 485 ro->count = count; 486 487 out_fil: 488 if (dev) 489 dev_put(dev); 490 491 release_sock(sk); 492 493 break; 494 495 case CAN_RAW_ERR_FILTER: 496 if (optlen != sizeof(err_mask)) 497 return -EINVAL; 498 499 if (copy_from_user(&err_mask, optval, optlen)) 500 return -EFAULT; 501 502 err_mask &= CAN_ERR_MASK; 503 504 lock_sock(sk); 505 506 if (ro->bound && ro->ifindex) 507 dev = dev_get_by_index(&init_net, ro->ifindex); 508 509 /* remove current error mask */ 510 if (ro->bound) { 511 /* (try to) register the new err_mask */ 512 err = raw_enable_errfilter(dev, sk, err_mask); 513 514 if (err) 515 goto out_err; 516 517 /* remove old err_mask registration */ 518 raw_disable_errfilter(dev, sk, ro->err_mask); 519 } 520 521 /* link new err_mask to the socket */ 522 ro->err_mask = err_mask; 523 524 out_err: 525 if (dev) 526 dev_put(dev); 527 528 release_sock(sk); 529 530 break; 531 532 case CAN_RAW_LOOPBACK: 533 if (optlen != sizeof(ro->loopback)) 534 return -EINVAL; 535 536 if (copy_from_user(&ro->loopback, optval, optlen)) 537 return -EFAULT; 538 539 break; 540 541 case CAN_RAW_RECV_OWN_MSGS: 542 if (optlen != sizeof(ro->recv_own_msgs)) 543 return -EINVAL; 544 545 if (copy_from_user(&ro->recv_own_msgs, optval, optlen)) 546 return -EFAULT; 547 548 break; 549 550 default: 551 return -ENOPROTOOPT; 552 } 553 return err; 554 } 555 556 static int raw_getsockopt(struct socket *sock, int level, int optname, 557 char __user *optval, int __user *optlen) 558 { 559 struct sock *sk = sock->sk; 560 struct raw_sock *ro = raw_sk(sk); 561 int len; 562 void *val; 563 int err = 0; 564 565 if (level != SOL_CAN_RAW) 566 return -EINVAL; 567 if (get_user(len, optlen)) 568 return -EFAULT; 569 if (len < 0) 570 return -EINVAL; 571 572 switch (optname) { 573 574 case CAN_RAW_FILTER: 575 lock_sock(sk); 576 if (ro->count > 0) { 577 int fsize = ro->count * sizeof(struct can_filter); 578 if (len > fsize) 579 len = fsize; 580 if (copy_to_user(optval, ro->filter, len)) 581 err = -EFAULT; 582 } else 583 len = 0; 584 release_sock(sk); 585 586 if (!err) 587 err = put_user(len, optlen); 588 return err; 589 590 case CAN_RAW_ERR_FILTER: 591 if (len > sizeof(can_err_mask_t)) 592 len = sizeof(can_err_mask_t); 593 val = &ro->err_mask; 594 break; 595 596 case CAN_RAW_LOOPBACK: 597 if (len > sizeof(int)) 598 len = sizeof(int); 599 val = &ro->loopback; 600 break; 601 602 case CAN_RAW_RECV_OWN_MSGS: 603 if (len > sizeof(int)) 604 len = sizeof(int); 605 val = &ro->recv_own_msgs; 606 break; 607 608 default: 609 return -ENOPROTOOPT; 610 } 611 612 if (put_user(len, optlen)) 613 return -EFAULT; 614 if (copy_to_user(optval, val, len)) 615 return -EFAULT; 616 return 0; 617 } 618 619 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock, 620 struct msghdr *msg, size_t size) 621 { 622 struct sock *sk = sock->sk; 623 struct raw_sock *ro = raw_sk(sk); 624 struct sk_buff *skb; 625 struct net_device *dev; 626 int ifindex; 627 int err; 628 629 if (msg->msg_name) { 630 struct sockaddr_can *addr = 631 (struct sockaddr_can *)msg->msg_name; 632 633 if (addr->can_family != AF_CAN) 634 return -EINVAL; 635 636 ifindex = addr->can_ifindex; 637 } else 638 ifindex = ro->ifindex; 639 640 if (size != sizeof(struct can_frame)) 641 return -EINVAL; 642 643 dev = dev_get_by_index(&init_net, ifindex); 644 if (!dev) 645 return -ENXIO; 646 647 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, 648 &err); 649 if (!skb) 650 goto put_dev; 651 652 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 653 if (err < 0) 654 goto free_skb; 655 err = sock_tx_timestamp(msg, sk, skb_tx(skb)); 656 if (err < 0) 657 goto free_skb; 658 skb->dev = dev; 659 skb->sk = sk; 660 661 err = can_send(skb, ro->loopback); 662 663 dev_put(dev); 664 665 if (err) 666 goto send_failed; 667 668 return size; 669 670 free_skb: 671 kfree_skb(skb); 672 put_dev: 673 dev_put(dev); 674 send_failed: 675 return err; 676 } 677 678 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock, 679 struct msghdr *msg, size_t size, int flags) 680 { 681 struct sock *sk = sock->sk; 682 struct sk_buff *skb; 683 int err = 0; 684 int noblock; 685 686 noblock = flags & MSG_DONTWAIT; 687 flags &= ~MSG_DONTWAIT; 688 689 skb = skb_recv_datagram(sk, flags, noblock, &err); 690 if (!skb) 691 return err; 692 693 if (size < skb->len) 694 msg->msg_flags |= MSG_TRUNC; 695 else 696 size = skb->len; 697 698 err = memcpy_toiovec(msg->msg_iov, skb->data, size); 699 if (err < 0) { 700 skb_free_datagram(sk, skb); 701 return err; 702 } 703 704 sock_recv_ts_and_drops(msg, sk, skb); 705 706 if (msg->msg_name) { 707 msg->msg_namelen = sizeof(struct sockaddr_can); 708 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 709 } 710 711 skb_free_datagram(sk, skb); 712 713 return size; 714 } 715 716 static struct proto_ops raw_ops __read_mostly = { 717 .family = PF_CAN, 718 .release = raw_release, 719 .bind = raw_bind, 720 .connect = sock_no_connect, 721 .socketpair = sock_no_socketpair, 722 .accept = sock_no_accept, 723 .getname = raw_getname, 724 .poll = datagram_poll, 725 .ioctl = NULL, /* use can_ioctl() from af_can.c */ 726 .listen = sock_no_listen, 727 .shutdown = sock_no_shutdown, 728 .setsockopt = raw_setsockopt, 729 .getsockopt = raw_getsockopt, 730 .sendmsg = raw_sendmsg, 731 .recvmsg = raw_recvmsg, 732 .mmap = sock_no_mmap, 733 .sendpage = sock_no_sendpage, 734 }; 735 736 static struct proto raw_proto __read_mostly = { 737 .name = "CAN_RAW", 738 .owner = THIS_MODULE, 739 .obj_size = sizeof(struct raw_sock), 740 .init = raw_init, 741 }; 742 743 static struct can_proto raw_can_proto __read_mostly = { 744 .type = SOCK_RAW, 745 .protocol = CAN_RAW, 746 .ops = &raw_ops, 747 .prot = &raw_proto, 748 }; 749 750 static __init int raw_module_init(void) 751 { 752 int err; 753 754 printk(banner); 755 756 err = can_proto_register(&raw_can_proto); 757 if (err < 0) 758 printk(KERN_ERR "can: registration of raw protocol failed\n"); 759 760 return err; 761 } 762 763 static __exit void raw_module_exit(void) 764 { 765 can_proto_unregister(&raw_can_proto); 766 } 767 768 module_init(raw_module_init); 769 module_exit(raw_module_exit); 770