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 addr->can_family = AF_CAN; 405 addr->can_ifindex = ro->ifindex; 406 407 *len = sizeof(*addr); 408 409 return 0; 410 } 411 412 static int raw_setsockopt(struct socket *sock, int level, int optname, 413 char __user *optval, int optlen) 414 { 415 struct sock *sk = sock->sk; 416 struct raw_sock *ro = raw_sk(sk); 417 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 418 struct can_filter sfilter; /* single filter */ 419 struct net_device *dev = NULL; 420 can_err_mask_t err_mask = 0; 421 int count = 0; 422 int err = 0; 423 424 if (level != SOL_CAN_RAW) 425 return -EINVAL; 426 if (optlen < 0) 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, optlen)) 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_timestamp(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 .capability = -1, 747 .ops = &raw_ops, 748 .prot = &raw_proto, 749 }; 750 751 static __init int raw_module_init(void) 752 { 753 int err; 754 755 printk(banner); 756 757 err = can_proto_register(&raw_can_proto); 758 if (err < 0) 759 printk(KERN_ERR "can: registration of raw protocol failed\n"); 760 761 return err; 762 } 763 764 static __exit void raw_module_exit(void) 765 { 766 can_proto_unregister(&raw_can_proto); 767 } 768 769 module_init(raw_module_init); 770 module_exit(raw_module_exit); 771