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/netdevice.h> 49 #include <linux/socket.h> 50 #include <linux/if_arp.h> 51 #include <linux/skbuff.h> 52 #include <linux/can.h> 53 #include <linux/can/core.h> 54 #include <linux/can/raw.h> 55 #include <net/sock.h> 56 #include <net/net_namespace.h> 57 58 #define CAN_RAW_VERSION CAN_VERSION 59 static __initdata const char banner[] = 60 KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n"; 61 62 MODULE_DESCRIPTION("PF_CAN raw protocol"); 63 MODULE_LICENSE("Dual BSD/GPL"); 64 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>"); 65 MODULE_ALIAS("can-proto-1"); 66 67 #define MASK_ALL 0 68 69 /* 70 * A raw socket has a list of can_filters attached to it, each receiving 71 * the CAN frames matching that filter. If the filter list is empty, 72 * no CAN frames will be received by the socket. The default after 73 * opening the socket, is to have one filter which receives all frames. 74 * The filter list is allocated dynamically with the exception of the 75 * list containing only one item. This common case is optimized by 76 * storing the single filter in dfilter, to avoid using dynamic memory. 77 */ 78 79 struct raw_sock { 80 struct sock sk; 81 int bound; 82 int ifindex; 83 struct notifier_block notifier; 84 int loopback; 85 int recv_own_msgs; 86 int count; /* number of active filters */ 87 struct can_filter dfilter; /* default/single filter */ 88 struct can_filter *filter; /* pointer to filter(s) */ 89 can_err_mask_t err_mask; 90 }; 91 92 static inline struct raw_sock *raw_sk(const struct sock *sk) 93 { 94 return (struct raw_sock *)sk; 95 } 96 97 static void raw_rcv(struct sk_buff *skb, void *data) 98 { 99 struct sock *sk = (struct sock *)data; 100 struct raw_sock *ro = raw_sk(sk); 101 struct sockaddr_can *addr; 102 103 /* check the received tx sock reference */ 104 if (!ro->recv_own_msgs && skb->sk == sk) 105 return; 106 107 /* clone the given skb to be able to enqueue it into the rcv queue */ 108 skb = skb_clone(skb, GFP_ATOMIC); 109 if (!skb) 110 return; 111 112 /* 113 * Put the datagram to the queue so that raw_recvmsg() can 114 * get it from there. We need to pass the interface index to 115 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 116 * containing the interface index. 117 */ 118 119 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can)); 120 addr = (struct sockaddr_can *)skb->cb; 121 memset(addr, 0, sizeof(*addr)); 122 addr->can_family = AF_CAN; 123 addr->can_ifindex = skb->dev->ifindex; 124 125 if (sock_queue_rcv_skb(sk, skb) < 0) 126 kfree_skb(skb); 127 } 128 129 static int raw_enable_filters(struct net_device *dev, struct sock *sk, 130 struct can_filter *filter, int count) 131 { 132 int err = 0; 133 int i; 134 135 for (i = 0; i < count; i++) { 136 err = can_rx_register(dev, filter[i].can_id, 137 filter[i].can_mask, 138 raw_rcv, sk, "raw"); 139 if (err) { 140 /* clean up successfully registered filters */ 141 while (--i >= 0) 142 can_rx_unregister(dev, filter[i].can_id, 143 filter[i].can_mask, 144 raw_rcv, sk); 145 break; 146 } 147 } 148 149 return err; 150 } 151 152 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk, 153 can_err_mask_t err_mask) 154 { 155 int err = 0; 156 157 if (err_mask) 158 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG, 159 raw_rcv, sk, "raw"); 160 161 return err; 162 } 163 164 static void raw_disable_filters(struct net_device *dev, struct sock *sk, 165 struct can_filter *filter, int count) 166 { 167 int i; 168 169 for (i = 0; i < count; i++) 170 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask, 171 raw_rcv, sk); 172 } 173 174 static inline void raw_disable_errfilter(struct net_device *dev, 175 struct sock *sk, 176 can_err_mask_t err_mask) 177 178 { 179 if (err_mask) 180 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG, 181 raw_rcv, sk); 182 } 183 184 static inline void raw_disable_allfilters(struct net_device *dev, 185 struct sock *sk) 186 { 187 struct raw_sock *ro = raw_sk(sk); 188 189 raw_disable_filters(dev, sk, ro->filter, ro->count); 190 raw_disable_errfilter(dev, sk, ro->err_mask); 191 } 192 193 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk) 194 { 195 struct raw_sock *ro = raw_sk(sk); 196 int err; 197 198 err = raw_enable_filters(dev, sk, ro->filter, ro->count); 199 if (!err) { 200 err = raw_enable_errfilter(dev, sk, ro->err_mask); 201 if (err) 202 raw_disable_filters(dev, sk, ro->filter, ro->count); 203 } 204 205 return err; 206 } 207 208 static int raw_notifier(struct notifier_block *nb, 209 unsigned long msg, void *data) 210 { 211 struct net_device *dev = (struct net_device *)data; 212 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier); 213 struct sock *sk = &ro->sk; 214 215 if (!net_eq(dev_net(dev), &init_net)) 216 return NOTIFY_DONE; 217 218 if (dev->type != ARPHRD_CAN) 219 return NOTIFY_DONE; 220 221 if (ro->ifindex != dev->ifindex) 222 return NOTIFY_DONE; 223 224 switch (msg) { 225 226 case NETDEV_UNREGISTER: 227 lock_sock(sk); 228 /* remove current filters & unregister */ 229 if (ro->bound) 230 raw_disable_allfilters(dev, sk); 231 232 if (ro->count > 1) 233 kfree(ro->filter); 234 235 ro->ifindex = 0; 236 ro->bound = 0; 237 ro->count = 0; 238 release_sock(sk); 239 240 sk->sk_err = ENODEV; 241 if (!sock_flag(sk, SOCK_DEAD)) 242 sk->sk_error_report(sk); 243 break; 244 245 case NETDEV_DOWN: 246 sk->sk_err = ENETDOWN; 247 if (!sock_flag(sk, SOCK_DEAD)) 248 sk->sk_error_report(sk); 249 break; 250 } 251 252 return NOTIFY_DONE; 253 } 254 255 static int raw_init(struct sock *sk) 256 { 257 struct raw_sock *ro = raw_sk(sk); 258 259 ro->bound = 0; 260 ro->ifindex = 0; 261 262 /* set default filter to single entry dfilter */ 263 ro->dfilter.can_id = 0; 264 ro->dfilter.can_mask = MASK_ALL; 265 ro->filter = &ro->dfilter; 266 ro->count = 1; 267 268 /* set default loopback behaviour */ 269 ro->loopback = 1; 270 ro->recv_own_msgs = 0; 271 272 /* set notifier */ 273 ro->notifier.notifier_call = raw_notifier; 274 275 register_netdevice_notifier(&ro->notifier); 276 277 return 0; 278 } 279 280 static int raw_release(struct socket *sock) 281 { 282 struct sock *sk = sock->sk; 283 struct raw_sock *ro = raw_sk(sk); 284 285 unregister_netdevice_notifier(&ro->notifier); 286 287 lock_sock(sk); 288 289 /* remove current filters & unregister */ 290 if (ro->bound) { 291 if (ro->ifindex) { 292 struct net_device *dev; 293 294 dev = dev_get_by_index(&init_net, ro->ifindex); 295 if (dev) { 296 raw_disable_allfilters(dev, sk); 297 dev_put(dev); 298 } 299 } else 300 raw_disable_allfilters(NULL, sk); 301 } 302 303 if (ro->count > 1) 304 kfree(ro->filter); 305 306 ro->ifindex = 0; 307 ro->bound = 0; 308 ro->count = 0; 309 310 sock_orphan(sk); 311 sock->sk = NULL; 312 313 release_sock(sk); 314 sock_put(sk); 315 316 return 0; 317 } 318 319 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 320 { 321 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 322 struct sock *sk = sock->sk; 323 struct raw_sock *ro = raw_sk(sk); 324 int ifindex; 325 int err = 0; 326 int notify_enetdown = 0; 327 328 if (len < sizeof(*addr)) 329 return -EINVAL; 330 331 lock_sock(sk); 332 333 if (ro->bound && addr->can_ifindex == ro->ifindex) 334 goto out; 335 336 if (addr->can_ifindex) { 337 struct net_device *dev; 338 339 dev = dev_get_by_index(&init_net, addr->can_ifindex); 340 if (!dev) { 341 err = -ENODEV; 342 goto out; 343 } 344 if (dev->type != ARPHRD_CAN) { 345 dev_put(dev); 346 err = -ENODEV; 347 goto out; 348 } 349 if (!(dev->flags & IFF_UP)) 350 notify_enetdown = 1; 351 352 ifindex = dev->ifindex; 353 354 /* filters set by default/setsockopt */ 355 err = raw_enable_allfilters(dev, sk); 356 dev_put(dev); 357 } else { 358 ifindex = 0; 359 360 /* filters set by default/setsockopt */ 361 err = raw_enable_allfilters(NULL, sk); 362 } 363 364 if (!err) { 365 if (ro->bound) { 366 /* unregister old filters */ 367 if (ro->ifindex) { 368 struct net_device *dev; 369 370 dev = dev_get_by_index(&init_net, ro->ifindex); 371 if (dev) { 372 raw_disable_allfilters(dev, sk); 373 dev_put(dev); 374 } 375 } else 376 raw_disable_allfilters(NULL, sk); 377 } 378 ro->ifindex = ifindex; 379 ro->bound = 1; 380 } 381 382 out: 383 release_sock(sk); 384 385 if (notify_enetdown) { 386 sk->sk_err = ENETDOWN; 387 if (!sock_flag(sk, SOCK_DEAD)) 388 sk->sk_error_report(sk); 389 } 390 391 return err; 392 } 393 394 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 395 int *len, int peer) 396 { 397 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 398 struct sock *sk = sock->sk; 399 struct raw_sock *ro = raw_sk(sk); 400 401 if (peer) 402 return -EOPNOTSUPP; 403 404 memset(addr, 0, sizeof(*addr)); 405 addr->can_family = AF_CAN; 406 addr->can_ifindex = ro->ifindex; 407 408 *len = sizeof(*addr); 409 410 return 0; 411 } 412 413 static int raw_setsockopt(struct socket *sock, int level, int optname, 414 char __user *optval, unsigned int optlen) 415 { 416 struct sock *sk = sock->sk; 417 struct raw_sock *ro = raw_sk(sk); 418 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 419 struct can_filter sfilter; /* single filter */ 420 struct net_device *dev = NULL; 421 can_err_mask_t err_mask = 0; 422 int count = 0; 423 int err = 0; 424 425 if (level != SOL_CAN_RAW) 426 return -EINVAL; 427 if (optlen < 0) 428 return -EINVAL; 429 430 switch (optname) { 431 432 case CAN_RAW_FILTER: 433 if (optlen % sizeof(struct can_filter) != 0) 434 return -EINVAL; 435 436 count = optlen / sizeof(struct can_filter); 437 438 if (count > 1) { 439 /* filter does not fit into dfilter => alloc space */ 440 filter = kmalloc(optlen, GFP_KERNEL); 441 if (!filter) 442 return -ENOMEM; 443 444 if (copy_from_user(filter, optval, optlen)) { 445 kfree(filter); 446 return -EFAULT; 447 } 448 } else if (count == 1) { 449 if (copy_from_user(&sfilter, optval, optlen)) 450 return -EFAULT; 451 } 452 453 lock_sock(sk); 454 455 if (ro->bound && ro->ifindex) 456 dev = dev_get_by_index(&init_net, ro->ifindex); 457 458 if (ro->bound) { 459 /* (try to) register the new filters */ 460 if (count == 1) 461 err = raw_enable_filters(dev, sk, &sfilter, 1); 462 else 463 err = raw_enable_filters(dev, sk, filter, 464 count); 465 if (err) { 466 if (count > 1) 467 kfree(filter); 468 goto out_fil; 469 } 470 471 /* remove old filter registrations */ 472 raw_disable_filters(dev, sk, ro->filter, ro->count); 473 } 474 475 /* remove old filter space */ 476 if (ro->count > 1) 477 kfree(ro->filter); 478 479 /* link new filters to the socket */ 480 if (count == 1) { 481 /* copy filter data for single filter */ 482 ro->dfilter = sfilter; 483 filter = &ro->dfilter; 484 } 485 ro->filter = filter; 486 ro->count = count; 487 488 out_fil: 489 if (dev) 490 dev_put(dev); 491 492 release_sock(sk); 493 494 break; 495 496 case CAN_RAW_ERR_FILTER: 497 if (optlen != sizeof(err_mask)) 498 return -EINVAL; 499 500 if (copy_from_user(&err_mask, optval, optlen)) 501 return -EFAULT; 502 503 err_mask &= CAN_ERR_MASK; 504 505 lock_sock(sk); 506 507 if (ro->bound && ro->ifindex) 508 dev = dev_get_by_index(&init_net, ro->ifindex); 509 510 /* remove current error mask */ 511 if (ro->bound) { 512 /* (try to) register the new err_mask */ 513 err = raw_enable_errfilter(dev, sk, err_mask); 514 515 if (err) 516 goto out_err; 517 518 /* remove old err_mask registration */ 519 raw_disable_errfilter(dev, sk, ro->err_mask); 520 } 521 522 /* link new err_mask to the socket */ 523 ro->err_mask = err_mask; 524 525 out_err: 526 if (dev) 527 dev_put(dev); 528 529 release_sock(sk); 530 531 break; 532 533 case CAN_RAW_LOOPBACK: 534 if (optlen != sizeof(ro->loopback)) 535 return -EINVAL; 536 537 if (copy_from_user(&ro->loopback, optval, optlen)) 538 return -EFAULT; 539 540 break; 541 542 case CAN_RAW_RECV_OWN_MSGS: 543 if (optlen != sizeof(ro->recv_own_msgs)) 544 return -EINVAL; 545 546 if (copy_from_user(&ro->recv_own_msgs, optval, optlen)) 547 return -EFAULT; 548 549 break; 550 551 default: 552 return -ENOPROTOOPT; 553 } 554 return err; 555 } 556 557 static int raw_getsockopt(struct socket *sock, int level, int optname, 558 char __user *optval, int __user *optlen) 559 { 560 struct sock *sk = sock->sk; 561 struct raw_sock *ro = raw_sk(sk); 562 int len; 563 void *val; 564 int err = 0; 565 566 if (level != SOL_CAN_RAW) 567 return -EINVAL; 568 if (get_user(len, optlen)) 569 return -EFAULT; 570 if (len < 0) 571 return -EINVAL; 572 573 switch (optname) { 574 575 case CAN_RAW_FILTER: 576 lock_sock(sk); 577 if (ro->count > 0) { 578 int fsize = ro->count * sizeof(struct can_filter); 579 if (len > fsize) 580 len = fsize; 581 if (copy_to_user(optval, ro->filter, len)) 582 err = -EFAULT; 583 } else 584 len = 0; 585 release_sock(sk); 586 587 if (!err) 588 err = put_user(len, optlen); 589 return err; 590 591 case CAN_RAW_ERR_FILTER: 592 if (len > sizeof(can_err_mask_t)) 593 len = sizeof(can_err_mask_t); 594 val = &ro->err_mask; 595 break; 596 597 case CAN_RAW_LOOPBACK: 598 if (len > sizeof(int)) 599 len = sizeof(int); 600 val = &ro->loopback; 601 break; 602 603 case CAN_RAW_RECV_OWN_MSGS: 604 if (len > sizeof(int)) 605 len = sizeof(int); 606 val = &ro->recv_own_msgs; 607 break; 608 609 default: 610 return -ENOPROTOOPT; 611 } 612 613 if (put_user(len, optlen)) 614 return -EFAULT; 615 if (copy_to_user(optval, val, len)) 616 return -EFAULT; 617 return 0; 618 } 619 620 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock, 621 struct msghdr *msg, size_t size) 622 { 623 struct sock *sk = sock->sk; 624 struct raw_sock *ro = raw_sk(sk); 625 struct sk_buff *skb; 626 struct net_device *dev; 627 int ifindex; 628 int err; 629 630 if (msg->msg_name) { 631 struct sockaddr_can *addr = 632 (struct sockaddr_can *)msg->msg_name; 633 634 if (addr->can_family != AF_CAN) 635 return -EINVAL; 636 637 ifindex = addr->can_ifindex; 638 } else 639 ifindex = ro->ifindex; 640 641 if (size != sizeof(struct can_frame)) 642 return -EINVAL; 643 644 dev = dev_get_by_index(&init_net, ifindex); 645 if (!dev) 646 return -ENXIO; 647 648 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, 649 &err); 650 if (!skb) 651 goto put_dev; 652 653 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 654 if (err < 0) 655 goto free_skb; 656 err = sock_tx_timestamp(msg, sk, skb_tx(skb)); 657 if (err < 0) 658 goto free_skb; 659 skb->dev = dev; 660 skb->sk = sk; 661 662 err = can_send(skb, ro->loopback); 663 664 dev_put(dev); 665 666 if (err) 667 goto send_failed; 668 669 return size; 670 671 free_skb: 672 kfree_skb(skb); 673 put_dev: 674 dev_put(dev); 675 send_failed: 676 return err; 677 } 678 679 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock, 680 struct msghdr *msg, size_t size, int flags) 681 { 682 struct sock *sk = sock->sk; 683 struct sk_buff *skb; 684 int err = 0; 685 int noblock; 686 687 noblock = flags & MSG_DONTWAIT; 688 flags &= ~MSG_DONTWAIT; 689 690 skb = skb_recv_datagram(sk, flags, noblock, &err); 691 if (!skb) 692 return err; 693 694 if (size < skb->len) 695 msg->msg_flags |= MSG_TRUNC; 696 else 697 size = skb->len; 698 699 err = memcpy_toiovec(msg->msg_iov, skb->data, size); 700 if (err < 0) { 701 skb_free_datagram(sk, skb); 702 return err; 703 } 704 705 sock_recv_timestamp(msg, sk, skb); 706 707 if (msg->msg_name) { 708 msg->msg_namelen = sizeof(struct sockaddr_can); 709 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 710 } 711 712 skb_free_datagram(sk, skb); 713 714 return size; 715 } 716 717 static struct proto_ops raw_ops __read_mostly = { 718 .family = PF_CAN, 719 .release = raw_release, 720 .bind = raw_bind, 721 .connect = sock_no_connect, 722 .socketpair = sock_no_socketpair, 723 .accept = sock_no_accept, 724 .getname = raw_getname, 725 .poll = datagram_poll, 726 .ioctl = NULL, /* use can_ioctl() from af_can.c */ 727 .listen = sock_no_listen, 728 .shutdown = sock_no_shutdown, 729 .setsockopt = raw_setsockopt, 730 .getsockopt = raw_getsockopt, 731 .sendmsg = raw_sendmsg, 732 .recvmsg = raw_recvmsg, 733 .mmap = sock_no_mmap, 734 .sendpage = sock_no_sendpage, 735 }; 736 737 static struct proto raw_proto __read_mostly = { 738 .name = "CAN_RAW", 739 .owner = THIS_MODULE, 740 .obj_size = sizeof(struct raw_sock), 741 .init = raw_init, 742 }; 743 744 static struct can_proto raw_can_proto __read_mostly = { 745 .type = SOCK_RAW, 746 .protocol = CAN_RAW, 747 .capability = -1, 748 .ops = &raw_ops, 749 .prot = &raw_proto, 750 }; 751 752 static __init int raw_module_init(void) 753 { 754 int err; 755 756 printk(banner); 757 758 err = can_proto_register(&raw_can_proto); 759 if (err < 0) 760 printk(KERN_ERR "can: registration of raw protocol failed\n"); 761 762 return err; 763 } 764 765 static __exit void raw_module_exit(void) 766 { 767 can_proto_unregister(&raw_can_proto); 768 } 769 770 module_init(raw_module_init); 771 module_exit(raw_module_exit); 772