net/can/raw.c

   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);