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 */ 41 42 #include <linux/module.h> 43 #include <linux/init.h> 44 #include <linux/uio.h> 45 #include <linux/net.h> 46 #include <linux/slab.h> 47 #include <linux/netdevice.h> 48 #include <linux/socket.h> 49 #include <linux/if_arp.h> 50 #include <linux/skbuff.h> 51 #include <linux/can.h> 52 #include <linux/can/core.h> 53 #include <linux/can/skb.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 60 MODULE_DESCRIPTION("PF_CAN raw protocol"); 61 MODULE_LICENSE("Dual BSD/GPL"); 62 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>"); 63 MODULE_ALIAS("can-proto-1"); 64 65 #define MASK_ALL 0 66 67 /* 68 * A raw socket has a list of can_filters attached to it, each receiving 69 * the CAN frames matching that filter. If the filter list is empty, 70 * no CAN frames will be received by the socket. The default after 71 * opening the socket, is to have one filter which receives all frames. 72 * The filter list is allocated dynamically with the exception of the 73 * list containing only one item. This common case is optimized by 74 * storing the single filter in dfilter, to avoid using dynamic memory. 75 */ 76 77 struct uniqframe { 78 int skbcnt; 79 const struct sk_buff *skb; 80 unsigned int join_rx_count; 81 }; 82 83 struct raw_sock { 84 struct sock sk; 85 int bound; 86 int ifindex; 87 struct notifier_block notifier; 88 int loopback; 89 int recv_own_msgs; 90 int fd_frames; 91 int join_filters; 92 int count; /* number of active filters */ 93 struct can_filter dfilter; /* default/single filter */ 94 struct can_filter *filter; /* pointer to filter(s) */ 95 can_err_mask_t err_mask; 96 struct uniqframe __percpu *uniq; 97 }; 98 99 /* 100 * Return pointer to store the extra msg flags for raw_recvmsg(). 101 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 102 * in skb->cb. 103 */ 104 static inline unsigned int *raw_flags(struct sk_buff *skb) 105 { 106 sock_skb_cb_check_size(sizeof(struct sockaddr_can) + 107 sizeof(unsigned int)); 108 109 /* return pointer after struct sockaddr_can */ 110 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 111 } 112 113 static inline struct raw_sock *raw_sk(const struct sock *sk) 114 { 115 return (struct raw_sock *)sk; 116 } 117 118 static void raw_rcv(struct sk_buff *oskb, void *data) 119 { 120 struct sock *sk = (struct sock *)data; 121 struct raw_sock *ro = raw_sk(sk); 122 struct sockaddr_can *addr; 123 struct sk_buff *skb; 124 unsigned int *pflags; 125 126 /* check the received tx sock reference */ 127 if (!ro->recv_own_msgs && oskb->sk == sk) 128 return; 129 130 /* do not pass non-CAN2.0 frames to a legacy socket */ 131 if (!ro->fd_frames && oskb->len != CAN_MTU) 132 return; 133 134 /* eliminate multiple filter matches for the same skb */ 135 if (this_cpu_ptr(ro->uniq)->skb == oskb && 136 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { 137 if (ro->join_filters) { 138 this_cpu_inc(ro->uniq->join_rx_count); 139 /* drop frame until all enabled filters matched */ 140 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) 141 return; 142 } else { 143 return; 144 } 145 } else { 146 this_cpu_ptr(ro->uniq)->skb = oskb; 147 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; 148 this_cpu_ptr(ro->uniq)->join_rx_count = 1; 149 /* drop first frame to check all enabled filters? */ 150 if (ro->join_filters && ro->count > 1) 151 return; 152 } 153 154 /* clone the given skb to be able to enqueue it into the rcv queue */ 155 skb = skb_clone(oskb, GFP_ATOMIC); 156 if (!skb) 157 return; 158 159 /* 160 * Put the datagram to the queue so that raw_recvmsg() can 161 * get it from there. We need to pass the interface index to 162 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 163 * containing the interface index. 164 */ 165 166 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 167 addr = (struct sockaddr_can *)skb->cb; 168 memset(addr, 0, sizeof(*addr)); 169 addr->can_family = AF_CAN; 170 addr->can_ifindex = skb->dev->ifindex; 171 172 /* add CAN specific message flags for raw_recvmsg() */ 173 pflags = raw_flags(skb); 174 *pflags = 0; 175 if (oskb->sk) 176 *pflags |= MSG_DONTROUTE; 177 if (oskb->sk == sk) 178 *pflags |= MSG_CONFIRM; 179 180 if (sock_queue_rcv_skb(sk, skb) < 0) 181 kfree_skb(skb); 182 } 183 184 static int raw_enable_filters(struct net_device *dev, struct sock *sk, 185 struct can_filter *filter, int count) 186 { 187 int err = 0; 188 int i; 189 190 for (i = 0; i < count; i++) { 191 err = can_rx_register(dev, filter[i].can_id, 192 filter[i].can_mask, 193 raw_rcv, sk, "raw"); 194 if (err) { 195 /* clean up successfully registered filters */ 196 while (--i >= 0) 197 can_rx_unregister(dev, filter[i].can_id, 198 filter[i].can_mask, 199 raw_rcv, sk); 200 break; 201 } 202 } 203 204 return err; 205 } 206 207 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk, 208 can_err_mask_t err_mask) 209 { 210 int err = 0; 211 212 if (err_mask) 213 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG, 214 raw_rcv, sk, "raw"); 215 216 return err; 217 } 218 219 static void raw_disable_filters(struct net_device *dev, struct sock *sk, 220 struct can_filter *filter, int count) 221 { 222 int i; 223 224 for (i = 0; i < count; i++) 225 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask, 226 raw_rcv, sk); 227 } 228 229 static inline void raw_disable_errfilter(struct net_device *dev, 230 struct sock *sk, 231 can_err_mask_t err_mask) 232 233 { 234 if (err_mask) 235 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG, 236 raw_rcv, sk); 237 } 238 239 static inline void raw_disable_allfilters(struct net_device *dev, 240 struct sock *sk) 241 { 242 struct raw_sock *ro = raw_sk(sk); 243 244 raw_disable_filters(dev, sk, ro->filter, ro->count); 245 raw_disable_errfilter(dev, sk, ro->err_mask); 246 } 247 248 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk) 249 { 250 struct raw_sock *ro = raw_sk(sk); 251 int err; 252 253 err = raw_enable_filters(dev, sk, ro->filter, ro->count); 254 if (!err) { 255 err = raw_enable_errfilter(dev, sk, ro->err_mask); 256 if (err) 257 raw_disable_filters(dev, sk, ro->filter, ro->count); 258 } 259 260 return err; 261 } 262 263 static int raw_notifier(struct notifier_block *nb, 264 unsigned long msg, void *ptr) 265 { 266 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 267 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier); 268 struct sock *sk = &ro->sk; 269 270 if (!net_eq(dev_net(dev), &init_net)) 271 return NOTIFY_DONE; 272 273 if (dev->type != ARPHRD_CAN) 274 return NOTIFY_DONE; 275 276 if (ro->ifindex != dev->ifindex) 277 return NOTIFY_DONE; 278 279 switch (msg) { 280 281 case NETDEV_UNREGISTER: 282 lock_sock(sk); 283 /* remove current filters & unregister */ 284 if (ro->bound) 285 raw_disable_allfilters(dev, sk); 286 287 if (ro->count > 1) 288 kfree(ro->filter); 289 290 ro->ifindex = 0; 291 ro->bound = 0; 292 ro->count = 0; 293 release_sock(sk); 294 295 sk->sk_err = ENODEV; 296 if (!sock_flag(sk, SOCK_DEAD)) 297 sk->sk_error_report(sk); 298 break; 299 300 case NETDEV_DOWN: 301 sk->sk_err = ENETDOWN; 302 if (!sock_flag(sk, SOCK_DEAD)) 303 sk->sk_error_report(sk); 304 break; 305 } 306 307 return NOTIFY_DONE; 308 } 309 310 static int raw_init(struct sock *sk) 311 { 312 struct raw_sock *ro = raw_sk(sk); 313 314 ro->bound = 0; 315 ro->ifindex = 0; 316 317 /* set default filter to single entry dfilter */ 318 ro->dfilter.can_id = 0; 319 ro->dfilter.can_mask = MASK_ALL; 320 ro->filter = &ro->dfilter; 321 ro->count = 1; 322 323 /* set default loopback behaviour */ 324 ro->loopback = 1; 325 ro->recv_own_msgs = 0; 326 ro->fd_frames = 0; 327 ro->join_filters = 0; 328 329 /* alloc_percpu provides zero'ed memory */ 330 ro->uniq = alloc_percpu(struct uniqframe); 331 if (unlikely(!ro->uniq)) 332 return -ENOMEM; 333 334 /* set notifier */ 335 ro->notifier.notifier_call = raw_notifier; 336 337 register_netdevice_notifier(&ro->notifier); 338 339 return 0; 340 } 341 342 static int raw_release(struct socket *sock) 343 { 344 struct sock *sk = sock->sk; 345 struct raw_sock *ro; 346 347 if (!sk) 348 return 0; 349 350 ro = raw_sk(sk); 351 352 unregister_netdevice_notifier(&ro->notifier); 353 354 lock_sock(sk); 355 356 /* remove current filters & unregister */ 357 if (ro->bound) { 358 if (ro->ifindex) { 359 struct net_device *dev; 360 361 dev = dev_get_by_index(&init_net, ro->ifindex); 362 if (dev) { 363 raw_disable_allfilters(dev, sk); 364 dev_put(dev); 365 } 366 } else 367 raw_disable_allfilters(NULL, sk); 368 } 369 370 if (ro->count > 1) 371 kfree(ro->filter); 372 373 ro->ifindex = 0; 374 ro->bound = 0; 375 ro->count = 0; 376 free_percpu(ro->uniq); 377 378 sock_orphan(sk); 379 sock->sk = NULL; 380 381 release_sock(sk); 382 sock_put(sk); 383 384 return 0; 385 } 386 387 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 388 { 389 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 390 struct sock *sk = sock->sk; 391 struct raw_sock *ro = raw_sk(sk); 392 int ifindex; 393 int err = 0; 394 int notify_enetdown = 0; 395 396 if (len < sizeof(*addr)) 397 return -EINVAL; 398 399 lock_sock(sk); 400 401 if (ro->bound && addr->can_ifindex == ro->ifindex) 402 goto out; 403 404 if (addr->can_ifindex) { 405 struct net_device *dev; 406 407 dev = dev_get_by_index(&init_net, addr->can_ifindex); 408 if (!dev) { 409 err = -ENODEV; 410 goto out; 411 } 412 if (dev->type != ARPHRD_CAN) { 413 dev_put(dev); 414 err = -ENODEV; 415 goto out; 416 } 417 if (!(dev->flags & IFF_UP)) 418 notify_enetdown = 1; 419 420 ifindex = dev->ifindex; 421 422 /* filters set by default/setsockopt */ 423 err = raw_enable_allfilters(dev, sk); 424 dev_put(dev); 425 } else { 426 ifindex = 0; 427 428 /* filters set by default/setsockopt */ 429 err = raw_enable_allfilters(NULL, sk); 430 } 431 432 if (!err) { 433 if (ro->bound) { 434 /* unregister old filters */ 435 if (ro->ifindex) { 436 struct net_device *dev; 437 438 dev = dev_get_by_index(&init_net, ro->ifindex); 439 if (dev) { 440 raw_disable_allfilters(dev, sk); 441 dev_put(dev); 442 } 443 } else 444 raw_disable_allfilters(NULL, sk); 445 } 446 ro->ifindex = ifindex; 447 ro->bound = 1; 448 } 449 450 out: 451 release_sock(sk); 452 453 if (notify_enetdown) { 454 sk->sk_err = ENETDOWN; 455 if (!sock_flag(sk, SOCK_DEAD)) 456 sk->sk_error_report(sk); 457 } 458 459 return err; 460 } 461 462 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 463 int *len, int peer) 464 { 465 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 466 struct sock *sk = sock->sk; 467 struct raw_sock *ro = raw_sk(sk); 468 469 if (peer) 470 return -EOPNOTSUPP; 471 472 memset(addr, 0, sizeof(*addr)); 473 addr->can_family = AF_CAN; 474 addr->can_ifindex = ro->ifindex; 475 476 *len = sizeof(*addr); 477 478 return 0; 479 } 480 481 static int raw_setsockopt(struct socket *sock, int level, int optname, 482 char __user *optval, unsigned int optlen) 483 { 484 struct sock *sk = sock->sk; 485 struct raw_sock *ro = raw_sk(sk); 486 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 487 struct can_filter sfilter; /* single filter */ 488 struct net_device *dev = NULL; 489 can_err_mask_t err_mask = 0; 490 int count = 0; 491 int err = 0; 492 493 if (level != SOL_CAN_RAW) 494 return -EINVAL; 495 496 switch (optname) { 497 498 case CAN_RAW_FILTER: 499 if (optlen % sizeof(struct can_filter) != 0) 500 return -EINVAL; 501 502 count = optlen / sizeof(struct can_filter); 503 504 if (count > 1) { 505 /* filter does not fit into dfilter => alloc space */ 506 filter = memdup_user(optval, optlen); 507 if (IS_ERR(filter)) 508 return PTR_ERR(filter); 509 } else if (count == 1) { 510 if (copy_from_user(&sfilter, optval, sizeof(sfilter))) 511 return -EFAULT; 512 } 513 514 lock_sock(sk); 515 516 if (ro->bound && ro->ifindex) 517 dev = dev_get_by_index(&init_net, ro->ifindex); 518 519 if (ro->bound) { 520 /* (try to) register the new filters */ 521 if (count == 1) 522 err = raw_enable_filters(dev, sk, &sfilter, 1); 523 else 524 err = raw_enable_filters(dev, sk, filter, 525 count); 526 if (err) { 527 if (count > 1) 528 kfree(filter); 529 goto out_fil; 530 } 531 532 /* remove old filter registrations */ 533 raw_disable_filters(dev, sk, ro->filter, ro->count); 534 } 535 536 /* remove old filter space */ 537 if (ro->count > 1) 538 kfree(ro->filter); 539 540 /* link new filters to the socket */ 541 if (count == 1) { 542 /* copy filter data for single filter */ 543 ro->dfilter = sfilter; 544 filter = &ro->dfilter; 545 } 546 ro->filter = filter; 547 ro->count = count; 548 549 out_fil: 550 if (dev) 551 dev_put(dev); 552 553 release_sock(sk); 554 555 break; 556 557 case CAN_RAW_ERR_FILTER: 558 if (optlen != sizeof(err_mask)) 559 return -EINVAL; 560 561 if (copy_from_user(&err_mask, optval, optlen)) 562 return -EFAULT; 563 564 err_mask &= CAN_ERR_MASK; 565 566 lock_sock(sk); 567 568 if (ro->bound && ro->ifindex) 569 dev = dev_get_by_index(&init_net, ro->ifindex); 570 571 /* remove current error mask */ 572 if (ro->bound) { 573 /* (try to) register the new err_mask */ 574 err = raw_enable_errfilter(dev, sk, err_mask); 575 576 if (err) 577 goto out_err; 578 579 /* remove old err_mask registration */ 580 raw_disable_errfilter(dev, sk, ro->err_mask); 581 } 582 583 /* link new err_mask to the socket */ 584 ro->err_mask = err_mask; 585 586 out_err: 587 if (dev) 588 dev_put(dev); 589 590 release_sock(sk); 591 592 break; 593 594 case CAN_RAW_LOOPBACK: 595 if (optlen != sizeof(ro->loopback)) 596 return -EINVAL; 597 598 if (copy_from_user(&ro->loopback, optval, optlen)) 599 return -EFAULT; 600 601 break; 602 603 case CAN_RAW_RECV_OWN_MSGS: 604 if (optlen != sizeof(ro->recv_own_msgs)) 605 return -EINVAL; 606 607 if (copy_from_user(&ro->recv_own_msgs, optval, optlen)) 608 return -EFAULT; 609 610 break; 611 612 case CAN_RAW_FD_FRAMES: 613 if (optlen != sizeof(ro->fd_frames)) 614 return -EINVAL; 615 616 if (copy_from_user(&ro->fd_frames, optval, optlen)) 617 return -EFAULT; 618 619 break; 620 621 case CAN_RAW_JOIN_FILTERS: 622 if (optlen != sizeof(ro->join_filters)) 623 return -EINVAL; 624 625 if (copy_from_user(&ro->join_filters, optval, optlen)) 626 return -EFAULT; 627 628 break; 629 630 default: 631 return -ENOPROTOOPT; 632 } 633 return err; 634 } 635 636 static int raw_getsockopt(struct socket *sock, int level, int optname, 637 char __user *optval, int __user *optlen) 638 { 639 struct sock *sk = sock->sk; 640 struct raw_sock *ro = raw_sk(sk); 641 int len; 642 void *val; 643 int err = 0; 644 645 if (level != SOL_CAN_RAW) 646 return -EINVAL; 647 if (get_user(len, optlen)) 648 return -EFAULT; 649 if (len < 0) 650 return -EINVAL; 651 652 switch (optname) { 653 654 case CAN_RAW_FILTER: 655 lock_sock(sk); 656 if (ro->count > 0) { 657 int fsize = ro->count * sizeof(struct can_filter); 658 if (len > fsize) 659 len = fsize; 660 if (copy_to_user(optval, ro->filter, len)) 661 err = -EFAULT; 662 } else 663 len = 0; 664 release_sock(sk); 665 666 if (!err) 667 err = put_user(len, optlen); 668 return err; 669 670 case CAN_RAW_ERR_FILTER: 671 if (len > sizeof(can_err_mask_t)) 672 len = sizeof(can_err_mask_t); 673 val = &ro->err_mask; 674 break; 675 676 case CAN_RAW_LOOPBACK: 677 if (len > sizeof(int)) 678 len = sizeof(int); 679 val = &ro->loopback; 680 break; 681 682 case CAN_RAW_RECV_OWN_MSGS: 683 if (len > sizeof(int)) 684 len = sizeof(int); 685 val = &ro->recv_own_msgs; 686 break; 687 688 case CAN_RAW_FD_FRAMES: 689 if (len > sizeof(int)) 690 len = sizeof(int); 691 val = &ro->fd_frames; 692 break; 693 694 case CAN_RAW_JOIN_FILTERS: 695 if (len > sizeof(int)) 696 len = sizeof(int); 697 val = &ro->join_filters; 698 break; 699 700 default: 701 return -ENOPROTOOPT; 702 } 703 704 if (put_user(len, optlen)) 705 return -EFAULT; 706 if (copy_to_user(optval, val, len)) 707 return -EFAULT; 708 return 0; 709 } 710 711 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 712 { 713 struct sock *sk = sock->sk; 714 struct raw_sock *ro = raw_sk(sk); 715 struct sk_buff *skb; 716 struct net_device *dev; 717 int ifindex; 718 int err; 719 720 if (msg->msg_name) { 721 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 722 723 if (msg->msg_namelen < sizeof(*addr)) 724 return -EINVAL; 725 726 if (addr->can_family != AF_CAN) 727 return -EINVAL; 728 729 ifindex = addr->can_ifindex; 730 } else 731 ifindex = ro->ifindex; 732 733 if (ro->fd_frames) { 734 if (unlikely(size != CANFD_MTU && size != CAN_MTU)) 735 return -EINVAL; 736 } else { 737 if (unlikely(size != CAN_MTU)) 738 return -EINVAL; 739 } 740 741 dev = dev_get_by_index(&init_net, ifindex); 742 if (!dev) 743 return -ENXIO; 744 745 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), 746 msg->msg_flags & MSG_DONTWAIT, &err); 747 if (!skb) 748 goto put_dev; 749 750 can_skb_reserve(skb); 751 can_skb_prv(skb)->ifindex = dev->ifindex; 752 can_skb_prv(skb)->skbcnt = 0; 753 754 err = memcpy_from_msg(skb_put(skb, size), msg, size); 755 if (err < 0) 756 goto free_skb; 757 758 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); 759 760 skb->dev = dev; 761 skb->sk = sk; 762 skb->priority = sk->sk_priority; 763 764 err = can_send(skb, ro->loopback); 765 766 dev_put(dev); 767 768 if (err) 769 goto send_failed; 770 771 return size; 772 773 free_skb: 774 kfree_skb(skb); 775 put_dev: 776 dev_put(dev); 777 send_failed: 778 return err; 779 } 780 781 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 782 int flags) 783 { 784 struct sock *sk = sock->sk; 785 struct sk_buff *skb; 786 int err = 0; 787 int noblock; 788 789 noblock = flags & MSG_DONTWAIT; 790 flags &= ~MSG_DONTWAIT; 791 792 skb = skb_recv_datagram(sk, flags, noblock, &err); 793 if (!skb) 794 return err; 795 796 if (size < skb->len) 797 msg->msg_flags |= MSG_TRUNC; 798 else 799 size = skb->len; 800 801 err = memcpy_to_msg(msg, skb->data, size); 802 if (err < 0) { 803 skb_free_datagram(sk, skb); 804 return err; 805 } 806 807 sock_recv_ts_and_drops(msg, sk, skb); 808 809 if (msg->msg_name) { 810 __sockaddr_check_size(sizeof(struct sockaddr_can)); 811 msg->msg_namelen = sizeof(struct sockaddr_can); 812 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 813 } 814 815 /* assign the flags that have been recorded in raw_rcv() */ 816 msg->msg_flags |= *(raw_flags(skb)); 817 818 skb_free_datagram(sk, skb); 819 820 return size; 821 } 822 823 static const struct proto_ops raw_ops = { 824 .family = PF_CAN, 825 .release = raw_release, 826 .bind = raw_bind, 827 .connect = sock_no_connect, 828 .socketpair = sock_no_socketpair, 829 .accept = sock_no_accept, 830 .getname = raw_getname, 831 .poll = datagram_poll, 832 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ 833 .listen = sock_no_listen, 834 .shutdown = sock_no_shutdown, 835 .setsockopt = raw_setsockopt, 836 .getsockopt = raw_getsockopt, 837 .sendmsg = raw_sendmsg, 838 .recvmsg = raw_recvmsg, 839 .mmap = sock_no_mmap, 840 .sendpage = sock_no_sendpage, 841 }; 842 843 static struct proto raw_proto __read_mostly = { 844 .name = "CAN_RAW", 845 .owner = THIS_MODULE, 846 .obj_size = sizeof(struct raw_sock), 847 .init = raw_init, 848 }; 849 850 static const struct can_proto raw_can_proto = { 851 .type = SOCK_RAW, 852 .protocol = CAN_RAW, 853 .ops = &raw_ops, 854 .prot = &raw_proto, 855 }; 856 857 static __init int raw_module_init(void) 858 { 859 int err; 860 861 pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n"); 862 863 err = can_proto_register(&raw_can_proto); 864 if (err < 0) 865 printk(KERN_ERR "can: registration of raw protocol failed\n"); 866 867 return err; 868 } 869 870 static __exit void raw_module_exit(void) 871 { 872 can_proto_unregister(&raw_can_proto); 873 } 874 875 module_init(raw_module_init); 876 module_exit(raw_module_exit); 877