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 /* 94 * Return pointer to store the extra msg flags for raw_recvmsg(). 95 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 96 * in skb->cb. 97 */ 98 static inline unsigned int *raw_flags(struct sk_buff *skb) 99 { 100 BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) + 101 sizeof(unsigned int))); 102 103 /* return pointer after struct sockaddr_can */ 104 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 105 } 106 107 static inline struct raw_sock *raw_sk(const struct sock *sk) 108 { 109 return (struct raw_sock *)sk; 110 } 111 112 static void raw_rcv(struct sk_buff *oskb, void *data) 113 { 114 struct sock *sk = (struct sock *)data; 115 struct raw_sock *ro = raw_sk(sk); 116 struct sockaddr_can *addr; 117 struct sk_buff *skb; 118 unsigned int *pflags; 119 120 /* check the received tx sock reference */ 121 if (!ro->recv_own_msgs && oskb->sk == sk) 122 return; 123 124 /* clone the given skb to be able to enqueue it into the rcv queue */ 125 skb = skb_clone(oskb, GFP_ATOMIC); 126 if (!skb) 127 return; 128 129 /* 130 * Put the datagram to the queue so that raw_recvmsg() can 131 * get it from there. We need to pass the interface index to 132 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 133 * containing the interface index. 134 */ 135 136 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can)); 137 addr = (struct sockaddr_can *)skb->cb; 138 memset(addr, 0, sizeof(*addr)); 139 addr->can_family = AF_CAN; 140 addr->can_ifindex = skb->dev->ifindex; 141 142 /* add CAN specific message flags for raw_recvmsg() */ 143 pflags = raw_flags(skb); 144 *pflags = 0; 145 if (oskb->sk) 146 *pflags |= MSG_DONTROUTE; 147 if (oskb->sk == sk) 148 *pflags |= MSG_CONFIRM; 149 150 if (sock_queue_rcv_skb(sk, skb) < 0) 151 kfree_skb(skb); 152 } 153 154 static int raw_enable_filters(struct net_device *dev, struct sock *sk, 155 struct can_filter *filter, int count) 156 { 157 int err = 0; 158 int i; 159 160 for (i = 0; i < count; i++) { 161 err = can_rx_register(dev, filter[i].can_id, 162 filter[i].can_mask, 163 raw_rcv, sk, "raw"); 164 if (err) { 165 /* clean up successfully registered filters */ 166 while (--i >= 0) 167 can_rx_unregister(dev, filter[i].can_id, 168 filter[i].can_mask, 169 raw_rcv, sk); 170 break; 171 } 172 } 173 174 return err; 175 } 176 177 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk, 178 can_err_mask_t err_mask) 179 { 180 int err = 0; 181 182 if (err_mask) 183 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG, 184 raw_rcv, sk, "raw"); 185 186 return err; 187 } 188 189 static void raw_disable_filters(struct net_device *dev, struct sock *sk, 190 struct can_filter *filter, int count) 191 { 192 int i; 193 194 for (i = 0; i < count; i++) 195 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask, 196 raw_rcv, sk); 197 } 198 199 static inline void raw_disable_errfilter(struct net_device *dev, 200 struct sock *sk, 201 can_err_mask_t err_mask) 202 203 { 204 if (err_mask) 205 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG, 206 raw_rcv, sk); 207 } 208 209 static inline void raw_disable_allfilters(struct net_device *dev, 210 struct sock *sk) 211 { 212 struct raw_sock *ro = raw_sk(sk); 213 214 raw_disable_filters(dev, sk, ro->filter, ro->count); 215 raw_disable_errfilter(dev, sk, ro->err_mask); 216 } 217 218 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk) 219 { 220 struct raw_sock *ro = raw_sk(sk); 221 int err; 222 223 err = raw_enable_filters(dev, sk, ro->filter, ro->count); 224 if (!err) { 225 err = raw_enable_errfilter(dev, sk, ro->err_mask); 226 if (err) 227 raw_disable_filters(dev, sk, ro->filter, ro->count); 228 } 229 230 return err; 231 } 232 233 static int raw_notifier(struct notifier_block *nb, 234 unsigned long msg, void *data) 235 { 236 struct net_device *dev = (struct net_device *)data; 237 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier); 238 struct sock *sk = &ro->sk; 239 240 if (!net_eq(dev_net(dev), &init_net)) 241 return NOTIFY_DONE; 242 243 if (dev->type != ARPHRD_CAN) 244 return NOTIFY_DONE; 245 246 if (ro->ifindex != dev->ifindex) 247 return NOTIFY_DONE; 248 249 switch (msg) { 250 251 case NETDEV_UNREGISTER: 252 lock_sock(sk); 253 /* remove current filters & unregister */ 254 if (ro->bound) 255 raw_disable_allfilters(dev, sk); 256 257 if (ro->count > 1) 258 kfree(ro->filter); 259 260 ro->ifindex = 0; 261 ro->bound = 0; 262 ro->count = 0; 263 release_sock(sk); 264 265 sk->sk_err = ENODEV; 266 if (!sock_flag(sk, SOCK_DEAD)) 267 sk->sk_error_report(sk); 268 break; 269 270 case NETDEV_DOWN: 271 sk->sk_err = ENETDOWN; 272 if (!sock_flag(sk, SOCK_DEAD)) 273 sk->sk_error_report(sk); 274 break; 275 } 276 277 return NOTIFY_DONE; 278 } 279 280 static int raw_init(struct sock *sk) 281 { 282 struct raw_sock *ro = raw_sk(sk); 283 284 ro->bound = 0; 285 ro->ifindex = 0; 286 287 /* set default filter to single entry dfilter */ 288 ro->dfilter.can_id = 0; 289 ro->dfilter.can_mask = MASK_ALL; 290 ro->filter = &ro->dfilter; 291 ro->count = 1; 292 293 /* set default loopback behaviour */ 294 ro->loopback = 1; 295 ro->recv_own_msgs = 0; 296 297 /* set notifier */ 298 ro->notifier.notifier_call = raw_notifier; 299 300 register_netdevice_notifier(&ro->notifier); 301 302 return 0; 303 } 304 305 static int raw_release(struct socket *sock) 306 { 307 struct sock *sk = sock->sk; 308 struct raw_sock *ro; 309 310 if (!sk) 311 return 0; 312 313 ro = raw_sk(sk); 314 315 unregister_netdevice_notifier(&ro->notifier); 316 317 lock_sock(sk); 318 319 /* remove current filters & unregister */ 320 if (ro->bound) { 321 if (ro->ifindex) { 322 struct net_device *dev; 323 324 dev = dev_get_by_index(&init_net, ro->ifindex); 325 if (dev) { 326 raw_disable_allfilters(dev, sk); 327 dev_put(dev); 328 } 329 } else 330 raw_disable_allfilters(NULL, sk); 331 } 332 333 if (ro->count > 1) 334 kfree(ro->filter); 335 336 ro->ifindex = 0; 337 ro->bound = 0; 338 ro->count = 0; 339 340 sock_orphan(sk); 341 sock->sk = NULL; 342 343 release_sock(sk); 344 sock_put(sk); 345 346 return 0; 347 } 348 349 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 350 { 351 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 352 struct sock *sk = sock->sk; 353 struct raw_sock *ro = raw_sk(sk); 354 int ifindex; 355 int err = 0; 356 int notify_enetdown = 0; 357 358 if (len < sizeof(*addr)) 359 return -EINVAL; 360 361 lock_sock(sk); 362 363 if (ro->bound && addr->can_ifindex == ro->ifindex) 364 goto out; 365 366 if (addr->can_ifindex) { 367 struct net_device *dev; 368 369 dev = dev_get_by_index(&init_net, addr->can_ifindex); 370 if (!dev) { 371 err = -ENODEV; 372 goto out; 373 } 374 if (dev->type != ARPHRD_CAN) { 375 dev_put(dev); 376 err = -ENODEV; 377 goto out; 378 } 379 if (!(dev->flags & IFF_UP)) 380 notify_enetdown = 1; 381 382 ifindex = dev->ifindex; 383 384 /* filters set by default/setsockopt */ 385 err = raw_enable_allfilters(dev, sk); 386 dev_put(dev); 387 } else { 388 ifindex = 0; 389 390 /* filters set by default/setsockopt */ 391 err = raw_enable_allfilters(NULL, sk); 392 } 393 394 if (!err) { 395 if (ro->bound) { 396 /* unregister old filters */ 397 if (ro->ifindex) { 398 struct net_device *dev; 399 400 dev = dev_get_by_index(&init_net, ro->ifindex); 401 if (dev) { 402 raw_disable_allfilters(dev, sk); 403 dev_put(dev); 404 } 405 } else 406 raw_disable_allfilters(NULL, sk); 407 } 408 ro->ifindex = ifindex; 409 ro->bound = 1; 410 } 411 412 out: 413 release_sock(sk); 414 415 if (notify_enetdown) { 416 sk->sk_err = ENETDOWN; 417 if (!sock_flag(sk, SOCK_DEAD)) 418 sk->sk_error_report(sk); 419 } 420 421 return err; 422 } 423 424 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 425 int *len, int peer) 426 { 427 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 428 struct sock *sk = sock->sk; 429 struct raw_sock *ro = raw_sk(sk); 430 431 if (peer) 432 return -EOPNOTSUPP; 433 434 memset(addr, 0, sizeof(*addr)); 435 addr->can_family = AF_CAN; 436 addr->can_ifindex = ro->ifindex; 437 438 *len = sizeof(*addr); 439 440 return 0; 441 } 442 443 static int raw_setsockopt(struct socket *sock, int level, int optname, 444 char __user *optval, unsigned int optlen) 445 { 446 struct sock *sk = sock->sk; 447 struct raw_sock *ro = raw_sk(sk); 448 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 449 struct can_filter sfilter; /* single filter */ 450 struct net_device *dev = NULL; 451 can_err_mask_t err_mask = 0; 452 int count = 0; 453 int err = 0; 454 455 if (level != SOL_CAN_RAW) 456 return -EINVAL; 457 458 switch (optname) { 459 460 case CAN_RAW_FILTER: 461 if (optlen % sizeof(struct can_filter) != 0) 462 return -EINVAL; 463 464 count = optlen / sizeof(struct can_filter); 465 466 if (count > 1) { 467 /* filter does not fit into dfilter => alloc space */ 468 filter = memdup_user(optval, optlen); 469 if (IS_ERR(filter)) 470 return PTR_ERR(filter); 471 } else if (count == 1) { 472 if (copy_from_user(&sfilter, optval, sizeof(sfilter))) 473 return -EFAULT; 474 } 475 476 lock_sock(sk); 477 478 if (ro->bound && ro->ifindex) 479 dev = dev_get_by_index(&init_net, ro->ifindex); 480 481 if (ro->bound) { 482 /* (try to) register the new filters */ 483 if (count == 1) 484 err = raw_enable_filters(dev, sk, &sfilter, 1); 485 else 486 err = raw_enable_filters(dev, sk, filter, 487 count); 488 if (err) { 489 if (count > 1) 490 kfree(filter); 491 goto out_fil; 492 } 493 494 /* remove old filter registrations */ 495 raw_disable_filters(dev, sk, ro->filter, ro->count); 496 } 497 498 /* remove old filter space */ 499 if (ro->count > 1) 500 kfree(ro->filter); 501 502 /* link new filters to the socket */ 503 if (count == 1) { 504 /* copy filter data for single filter */ 505 ro->dfilter = sfilter; 506 filter = &ro->dfilter; 507 } 508 ro->filter = filter; 509 ro->count = count; 510 511 out_fil: 512 if (dev) 513 dev_put(dev); 514 515 release_sock(sk); 516 517 break; 518 519 case CAN_RAW_ERR_FILTER: 520 if (optlen != sizeof(err_mask)) 521 return -EINVAL; 522 523 if (copy_from_user(&err_mask, optval, optlen)) 524 return -EFAULT; 525 526 err_mask &= CAN_ERR_MASK; 527 528 lock_sock(sk); 529 530 if (ro->bound && ro->ifindex) 531 dev = dev_get_by_index(&init_net, ro->ifindex); 532 533 /* remove current error mask */ 534 if (ro->bound) { 535 /* (try to) register the new err_mask */ 536 err = raw_enable_errfilter(dev, sk, err_mask); 537 538 if (err) 539 goto out_err; 540 541 /* remove old err_mask registration */ 542 raw_disable_errfilter(dev, sk, ro->err_mask); 543 } 544 545 /* link new err_mask to the socket */ 546 ro->err_mask = err_mask; 547 548 out_err: 549 if (dev) 550 dev_put(dev); 551 552 release_sock(sk); 553 554 break; 555 556 case CAN_RAW_LOOPBACK: 557 if (optlen != sizeof(ro->loopback)) 558 return -EINVAL; 559 560 if (copy_from_user(&ro->loopback, optval, optlen)) 561 return -EFAULT; 562 563 break; 564 565 case CAN_RAW_RECV_OWN_MSGS: 566 if (optlen != sizeof(ro->recv_own_msgs)) 567 return -EINVAL; 568 569 if (copy_from_user(&ro->recv_own_msgs, optval, optlen)) 570 return -EFAULT; 571 572 break; 573 574 default: 575 return -ENOPROTOOPT; 576 } 577 return err; 578 } 579 580 static int raw_getsockopt(struct socket *sock, int level, int optname, 581 char __user *optval, int __user *optlen) 582 { 583 struct sock *sk = sock->sk; 584 struct raw_sock *ro = raw_sk(sk); 585 int len; 586 void *val; 587 int err = 0; 588 589 if (level != SOL_CAN_RAW) 590 return -EINVAL; 591 if (get_user(len, optlen)) 592 return -EFAULT; 593 if (len < 0) 594 return -EINVAL; 595 596 switch (optname) { 597 598 case CAN_RAW_FILTER: 599 lock_sock(sk); 600 if (ro->count > 0) { 601 int fsize = ro->count * sizeof(struct can_filter); 602 if (len > fsize) 603 len = fsize; 604 if (copy_to_user(optval, ro->filter, len)) 605 err = -EFAULT; 606 } else 607 len = 0; 608 release_sock(sk); 609 610 if (!err) 611 err = put_user(len, optlen); 612 return err; 613 614 case CAN_RAW_ERR_FILTER: 615 if (len > sizeof(can_err_mask_t)) 616 len = sizeof(can_err_mask_t); 617 val = &ro->err_mask; 618 break; 619 620 case CAN_RAW_LOOPBACK: 621 if (len > sizeof(int)) 622 len = sizeof(int); 623 val = &ro->loopback; 624 break; 625 626 case CAN_RAW_RECV_OWN_MSGS: 627 if (len > sizeof(int)) 628 len = sizeof(int); 629 val = &ro->recv_own_msgs; 630 break; 631 632 default: 633 return -ENOPROTOOPT; 634 } 635 636 if (put_user(len, optlen)) 637 return -EFAULT; 638 if (copy_to_user(optval, val, len)) 639 return -EFAULT; 640 return 0; 641 } 642 643 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock, 644 struct msghdr *msg, size_t size) 645 { 646 struct sock *sk = sock->sk; 647 struct raw_sock *ro = raw_sk(sk); 648 struct sk_buff *skb; 649 struct net_device *dev; 650 int ifindex; 651 int err; 652 653 if (msg->msg_name) { 654 struct sockaddr_can *addr = 655 (struct sockaddr_can *)msg->msg_name; 656 657 if (msg->msg_namelen < sizeof(*addr)) 658 return -EINVAL; 659 660 if (addr->can_family != AF_CAN) 661 return -EINVAL; 662 663 ifindex = addr->can_ifindex; 664 } else 665 ifindex = ro->ifindex; 666 667 if (size != sizeof(struct can_frame)) 668 return -EINVAL; 669 670 dev = dev_get_by_index(&init_net, ifindex); 671 if (!dev) 672 return -ENXIO; 673 674 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, 675 &err); 676 if (!skb) 677 goto put_dev; 678 679 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 680 if (err < 0) 681 goto free_skb; 682 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 683 if (err < 0) 684 goto free_skb; 685 686 /* to be able to check the received tx sock reference in raw_rcv() */ 687 skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF; 688 689 skb->dev = dev; 690 skb->sk = sk; 691 692 err = can_send(skb, ro->loopback); 693 694 dev_put(dev); 695 696 if (err) 697 goto send_failed; 698 699 return size; 700 701 free_skb: 702 kfree_skb(skb); 703 put_dev: 704 dev_put(dev); 705 send_failed: 706 return err; 707 } 708 709 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock, 710 struct msghdr *msg, size_t size, int flags) 711 { 712 struct sock *sk = sock->sk; 713 struct sk_buff *skb; 714 int err = 0; 715 int noblock; 716 717 noblock = flags & MSG_DONTWAIT; 718 flags &= ~MSG_DONTWAIT; 719 720 skb = skb_recv_datagram(sk, flags, noblock, &err); 721 if (!skb) 722 return err; 723 724 if (size < skb->len) 725 msg->msg_flags |= MSG_TRUNC; 726 else 727 size = skb->len; 728 729 err = memcpy_toiovec(msg->msg_iov, skb->data, size); 730 if (err < 0) { 731 skb_free_datagram(sk, skb); 732 return err; 733 } 734 735 sock_recv_ts_and_drops(msg, sk, skb); 736 737 if (msg->msg_name) { 738 msg->msg_namelen = sizeof(struct sockaddr_can); 739 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 740 } 741 742 /* assign the flags that have been recorded in raw_rcv() */ 743 msg->msg_flags |= *(raw_flags(skb)); 744 745 skb_free_datagram(sk, skb); 746 747 return size; 748 } 749 750 static const struct proto_ops raw_ops = { 751 .family = PF_CAN, 752 .release = raw_release, 753 .bind = raw_bind, 754 .connect = sock_no_connect, 755 .socketpair = sock_no_socketpair, 756 .accept = sock_no_accept, 757 .getname = raw_getname, 758 .poll = datagram_poll, 759 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ 760 .listen = sock_no_listen, 761 .shutdown = sock_no_shutdown, 762 .setsockopt = raw_setsockopt, 763 .getsockopt = raw_getsockopt, 764 .sendmsg = raw_sendmsg, 765 .recvmsg = raw_recvmsg, 766 .mmap = sock_no_mmap, 767 .sendpage = sock_no_sendpage, 768 }; 769 770 static struct proto raw_proto __read_mostly = { 771 .name = "CAN_RAW", 772 .owner = THIS_MODULE, 773 .obj_size = sizeof(struct raw_sock), 774 .init = raw_init, 775 }; 776 777 static const struct can_proto raw_can_proto = { 778 .type = SOCK_RAW, 779 .protocol = CAN_RAW, 780 .ops = &raw_ops, 781 .prot = &raw_proto, 782 }; 783 784 static __init int raw_module_init(void) 785 { 786 int err; 787 788 printk(banner); 789 790 err = can_proto_register(&raw_can_proto); 791 if (err < 0) 792 printk(KERN_ERR "can: registration of raw protocol failed\n"); 793 794 return err; 795 } 796 797 static __exit void raw_module_exit(void) 798 { 799 can_proto_unregister(&raw_can_proto); 800 } 801 802 module_init(raw_module_init); 803 module_exit(raw_module_exit); 804