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 = raw_sk(sk);
 309
 310         unregister_netdevice_notifier(&ro->notifier);
 311
 312         lock_sock(sk);
 313
 314         /* remove current filters & unregister */
 315         if (ro->bound) {
 316                 if (ro->ifindex) {
 317                         struct net_device *dev;
 318
 319                         dev = dev_get_by_index(&init_net, ro->ifindex);
 320                         if (dev) {
 321                                 raw_disable_allfilters(dev, sk);
 322                                 dev_put(dev);
 323                         }
 324                 } else
 325                         raw_disable_allfilters(NULL, sk);
 326         }
 327
 328         if (ro->count > 1)
 329                 kfree(ro->filter);
 330
 331         ro->ifindex = 0;
 332         ro->bound   = 0;
 333         ro->count   = 0;
 334
 335         sock_orphan(sk);
 336         sock->sk = NULL;
 337
 338         release_sock(sk);
 339         sock_put(sk);
 340
 341         return 0;
 342 }
 343
 344 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 345 {
 346         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 347         struct sock *sk = sock->sk;
 348         struct raw_sock *ro = raw_sk(sk);
 349         int ifindex;
 350         int err = 0;
 351         int notify_enetdown = 0;
 352
 353         if (len < sizeof(*addr))
 354                 return -EINVAL;
 355
 356         lock_sock(sk);
 357
 358         if (ro->bound && addr->can_ifindex == ro->ifindex)
 359                 goto out;
 360
 361         if (addr->can_ifindex) {
 362                 struct net_device *dev;
 363
 364                 dev = dev_get_by_index(&init_net, addr->can_ifindex);
 365                 if (!dev) {
 366                         err = -ENODEV;
 367                         goto out;
 368                 }
 369                 if (dev->type != ARPHRD_CAN) {
 370                         dev_put(dev);
 371                         err = -ENODEV;
 372                         goto out;
 373                 }
 374                 if (!(dev->flags & IFF_UP))
 375                         notify_enetdown = 1;
 376
 377                 ifindex = dev->ifindex;
 378
 379                 /* filters set by default/setsockopt */
 380                 err = raw_enable_allfilters(dev, sk);
 381                 dev_put(dev);
 382         } else {
 383                 ifindex = 0;
 384
 385                 /* filters set by default/setsockopt */
 386                 err = raw_enable_allfilters(NULL, sk);
 387         }
 388
 389         if (!err) {
 390                 if (ro->bound) {
 391                         /* unregister old filters */
 392                         if (ro->ifindex) {
 393                                 struct net_device *dev;
 394
 395                                 dev = dev_get_by_index(&init_net, ro->ifindex);
 396                                 if (dev) {
 397                                         raw_disable_allfilters(dev, sk);
 398                                         dev_put(dev);
 399                                 }
 400                         } else
 401                                 raw_disable_allfilters(NULL, sk);
 402                 }
 403                 ro->ifindex = ifindex;
 404                 ro->bound = 1;
 405         }
 406
 407  out:
 408         release_sock(sk);
 409
 410         if (notify_enetdown) {
 411                 sk->sk_err = ENETDOWN;
 412                 if (!sock_flag(sk, SOCK_DEAD))
 413                         sk->sk_error_report(sk);
 414         }
 415
 416         return err;
 417 }
 418
 419 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
 420                        int *len, int peer)
 421 {
 422         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 423         struct sock *sk = sock->sk;
 424         struct raw_sock *ro = raw_sk(sk);
 425
 426         if (peer)
 427                 return -EOPNOTSUPP;
 428
 429         memset(addr, 0, sizeof(*addr));
 430         addr->can_family  = AF_CAN;
 431         addr->can_ifindex = ro->ifindex;
 432
 433         *len = sizeof(*addr);
 434
 435         return 0;
 436 }
 437
 438 static int raw_setsockopt(struct socket *sock, int level, int optname,
 439                           char __user *optval, unsigned int optlen)
 440 {
 441         struct sock *sk = sock->sk;
 442         struct raw_sock *ro = raw_sk(sk);
 443         struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
 444         struct can_filter sfilter;         /* single filter */
 445         struct net_device *dev = NULL;
 446         can_err_mask_t err_mask = 0;
 447         int count = 0;
 448         int err = 0;
 449
 450         if (level != SOL_CAN_RAW)
 451                 return -EINVAL;
 452
 453         switch (optname) {
 454
 455         case CAN_RAW_FILTER:
 456                 if (optlen % sizeof(struct can_filter) != 0)
 457                         return -EINVAL;
 458
 459                 count = optlen / sizeof(struct can_filter);
 460
 461                 if (count > 1) {
 462                         /* filter does not fit into dfilter => alloc space */
 463                         filter = memdup_user(optval, optlen);
 464                         if (IS_ERR(filter))
 465                                 return PTR_ERR(filter);
 466                 } else if (count == 1) {
 467                         if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
 468                                 return -EFAULT;
 469                 }
 470
 471                 lock_sock(sk);
 472
 473                 if (ro->bound && ro->ifindex)
 474                         dev = dev_get_by_index(&init_net, ro->ifindex);
 475
 476                 if (ro->bound) {
 477                         /* (try to) register the new filters */
 478                         if (count == 1)
 479                                 err = raw_enable_filters(dev, sk, &sfilter, 1);
 480                         else
 481                                 err = raw_enable_filters(dev, sk, filter,
 482                                                          count);
 483                         if (err) {
 484                                 if (count > 1)
 485                                         kfree(filter);
 486                                 goto out_fil;
 487                         }
 488
 489                         /* remove old filter registrations */
 490                         raw_disable_filters(dev, sk, ro->filter, ro->count);
 491                 }
 492
 493                 /* remove old filter space */
 494                 if (ro->count > 1)
 495                         kfree(ro->filter);
 496
 497                 /* link new filters to the socket */
 498                 if (count == 1) {
 499                         /* copy filter data for single filter */
 500                         ro->dfilter = sfilter;
 501                         filter = &ro->dfilter;
 502                 }
 503                 ro->filter = filter;
 504                 ro->count  = count;
 505
 506  out_fil:
 507                 if (dev)
 508                         dev_put(dev);
 509
 510                 release_sock(sk);
 511
 512                 break;
 513
 514         case CAN_RAW_ERR_FILTER:
 515                 if (optlen != sizeof(err_mask))
 516                         return -EINVAL;
 517
 518                 if (copy_from_user(&err_mask, optval, optlen))
 519                         return -EFAULT;
 520
 521                 err_mask &= CAN_ERR_MASK;
 522
 523                 lock_sock(sk);
 524
 525                 if (ro->bound && ro->ifindex)
 526                         dev = dev_get_by_index(&init_net, ro->ifindex);
 527
 528                 /* remove current error mask */
 529                 if (ro->bound) {
 530                         /* (try to) register the new err_mask */
 531                         err = raw_enable_errfilter(dev, sk, err_mask);
 532
 533                         if (err)
 534                                 goto out_err;
 535
 536                         /* remove old err_mask registration */
 537                         raw_disable_errfilter(dev, sk, ro->err_mask);
 538                 }
 539
 540                 /* link new err_mask to the socket */
 541                 ro->err_mask = err_mask;
 542
 543  out_err:
 544                 if (dev)
 545                         dev_put(dev);
 546
 547                 release_sock(sk);
 548
 549                 break;
 550
 551         case CAN_RAW_LOOPBACK:
 552                 if (optlen != sizeof(ro->loopback))
 553                         return -EINVAL;
 554
 555                 if (copy_from_user(&ro->loopback, optval, optlen))
 556                         return -EFAULT;
 557
 558                 break;
 559
 560         case CAN_RAW_RECV_OWN_MSGS:
 561                 if (optlen != sizeof(ro->recv_own_msgs))
 562                         return -EINVAL;
 563
 564                 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
 565                         return -EFAULT;
 566
 567                 break;
 568
 569         default:
 570                 return -ENOPROTOOPT;
 571         }
 572         return err;
 573 }
 574
 575 static int raw_getsockopt(struct socket *sock, int level, int optname,
 576                           char __user *optval, int __user *optlen)
 577 {
 578         struct sock *sk = sock->sk;
 579         struct raw_sock *ro = raw_sk(sk);
 580         int len;
 581         void *val;
 582         int err = 0;
 583
 584         if (level != SOL_CAN_RAW)
 585                 return -EINVAL;
 586         if (get_user(len, optlen))
 587                 return -EFAULT;
 588         if (len < 0)
 589                 return -EINVAL;
 590
 591         switch (optname) {
 592
 593         case CAN_RAW_FILTER:
 594                 lock_sock(sk);
 595                 if (ro->count > 0) {
 596                         int fsize = ro->count * sizeof(struct can_filter);
 597                         if (len > fsize)
 598                                 len = fsize;
 599                         if (copy_to_user(optval, ro->filter, len))
 600                                 err = -EFAULT;
 601                 } else
 602                         len = 0;
 603                 release_sock(sk);
 604
 605                 if (!err)
 606                         err = put_user(len, optlen);
 607                 return err;
 608
 609         case CAN_RAW_ERR_FILTER:
 610                 if (len > sizeof(can_err_mask_t))
 611                         len = sizeof(can_err_mask_t);
 612                 val = &ro->err_mask;
 613                 break;
 614
 615         case CAN_RAW_LOOPBACK:
 616                 if (len > sizeof(int))
 617                         len = sizeof(int);
 618                 val = &ro->loopback;
 619                 break;
 620
 621         case CAN_RAW_RECV_OWN_MSGS:
 622                 if (len > sizeof(int))
 623                         len = sizeof(int);
 624                 val = &ro->recv_own_msgs;
 625                 break;
 626
 627         default:
 628                 return -ENOPROTOOPT;
 629         }
 630
 631         if (put_user(len, optlen))
 632                 return -EFAULT;
 633         if (copy_to_user(optval, val, len))
 634                 return -EFAULT;
 635         return 0;
 636 }
 637
 638 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 639                        struct msghdr *msg, size_t size)
 640 {
 641         struct sock *sk = sock->sk;
 642         struct raw_sock *ro = raw_sk(sk);
 643         struct sk_buff *skb;
 644         struct net_device *dev;
 645         int ifindex;
 646         int err;
 647
 648         if (msg->msg_name) {
 649                 struct sockaddr_can *addr =
 650                         (struct sockaddr_can *)msg->msg_name;
 651
 652                 if (addr->can_family != AF_CAN)
 653                         return -EINVAL;
 654
 655                 ifindex = addr->can_ifindex;
 656         } else
 657                 ifindex = ro->ifindex;
 658
 659         if (size != sizeof(struct can_frame))
 660                 return -EINVAL;
 661
 662         dev = dev_get_by_index(&init_net, ifindex);
 663         if (!dev)
 664                 return -ENXIO;
 665
 666         skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
 667                                   &err);
 668         if (!skb)
 669                 goto put_dev;
 670
 671         err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 672         if (err < 0)
 673                 goto free_skb;
 674         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
 675         if (err < 0)
 676                 goto free_skb;
 677
 678         /* to be able to check the received tx sock reference in raw_rcv() */
 679         skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF;
 680
 681         skb->dev = dev;
 682         skb->sk  = sk;
 683
 684         err = can_send(skb, ro->loopback);
 685
 686         dev_put(dev);
 687
 688         if (err)
 689                 goto send_failed;
 690
 691         return size;
 692
 693 free_skb:
 694         kfree_skb(skb);
 695 put_dev:
 696         dev_put(dev);
 697 send_failed:
 698         return err;
 699 }
 700
 701 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 702                        struct msghdr *msg, size_t size, int flags)
 703 {
 704         struct sock *sk = sock->sk;
 705         struct sk_buff *skb;
 706         int err = 0;
 707         int noblock;
 708
 709         noblock =  flags & MSG_DONTWAIT;
 710         flags   &= ~MSG_DONTWAIT;
 711
 712         skb = skb_recv_datagram(sk, flags, noblock, &err);
 713         if (!skb)
 714                 return err;
 715
 716         if (size < skb->len)
 717                 msg->msg_flags |= MSG_TRUNC;
 718         else
 719                 size = skb->len;
 720
 721         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
 722         if (err < 0) {
 723                 skb_free_datagram(sk, skb);
 724                 return err;
 725         }
 726
 727         sock_recv_ts_and_drops(msg, sk, skb);
 728
 729         if (msg->msg_name) {
 730                 msg->msg_namelen = sizeof(struct sockaddr_can);
 731                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 732         }
 733
 734         /* assign the flags that have been recorded in raw_rcv() */
 735         msg->msg_flags |= *(raw_flags(skb));
 736
 737         skb_free_datagram(sk, skb);
 738
 739         return size;
 740 }
 741
 742 static struct proto_ops raw_ops __read_mostly = {
 743         .family        = PF_CAN,
 744         .release       = raw_release,
 745         .bind          = raw_bind,
 746         .connect       = sock_no_connect,
 747         .socketpair    = sock_no_socketpair,
 748         .accept        = sock_no_accept,
 749         .getname       = raw_getname,
 750         .poll          = datagram_poll,
 751         .ioctl         = NULL,          /* use can_ioctl() from af_can.c */
 752         .listen        = sock_no_listen,
 753         .shutdown      = sock_no_shutdown,
 754         .setsockopt    = raw_setsockopt,
 755         .getsockopt    = raw_getsockopt,
 756         .sendmsg       = raw_sendmsg,
 757         .recvmsg       = raw_recvmsg,
 758         .mmap          = sock_no_mmap,
 759         .sendpage      = sock_no_sendpage,
 760 };
 761
 762 static struct proto raw_proto __read_mostly = {
 763         .name       = "CAN_RAW",
 764         .owner      = THIS_MODULE,
 765         .obj_size   = sizeof(struct raw_sock),
 766         .init       = raw_init,
 767 };
 768
 769 static struct can_proto raw_can_proto __read_mostly = {
 770         .type       = SOCK_RAW,
 771         .protocol   = CAN_RAW,
 772         .ops        = &raw_ops,
 773         .prot       = &raw_proto,
 774 };
 775
 776 static __init int raw_module_init(void)
 777 {
 778         int err;
 779
 780         printk(banner);
 781
 782         err = can_proto_register(&raw_can_proto);
 783         if (err < 0)
 784                 printk(KERN_ERR "can: registration of raw protocol failed\n");
 785
 786         return err;
 787 }
 788
 789 static __exit void raw_module_exit(void)
 790 {
 791         can_proto_unregister(&raw_can_proto);
 792 }
 793
 794 module_init(raw_module_init);
 795 module_exit(raw_module_exit);