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  */
  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/raw.h>
  54 #include <net/sock.h>
  55 #include <net/net_namespace.h>
  56
  57 #define CAN_RAW_VERSION CAN_VERSION
  58 static __initdata const char banner[] =
  59         KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";
  60
  61 MODULE_DESCRIPTION("PF_CAN raw protocol");
  62 MODULE_LICENSE("Dual BSD/GPL");
  63 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
  64 MODULE_ALIAS("can-proto-1");
  65
  66 #define MASK_ALL 0
  67
  68 /*
  69  * A raw socket has a list of can_filters attached to it, each receiving
  70  * the CAN frames matching that filter.  If the filter list is empty,
  71  * no CAN frames will be received by the socket.  The default after
  72  * opening the socket, is to have one filter which receives all frames.
  73  * The filter list is allocated dynamically with the exception of the
  74  * list containing only one item.  This common case is optimized by
  75  * storing the single filter in dfilter, to avoid using dynamic memory.
  76  */
  77
  78 struct raw_sock {
  79         struct sock sk;
  80         int bound;
  81         int ifindex;
  82         struct notifier_block notifier;
  83         int loopback;
  84         int recv_own_msgs;
  85         int count;                 /* number of active filters */
  86         struct can_filter dfilter; /* default/single filter */
  87         struct can_filter *filter; /* pointer to filter(s) */
  88         can_err_mask_t err_mask;
  89 };
  90
  91 /*
  92  * Return pointer to store the extra msg flags for raw_recvmsg().
  93  * We use the space of one unsigned int beyond the 'struct sockaddr_can'
  94  * in skb->cb.
  95  */
  96 static inline unsigned int *raw_flags(struct sk_buff *skb)
  97 {
  98         BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
  99                                          sizeof(unsigned int)));
 100
 101         /* return pointer after struct sockaddr_can */
 102         return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
 103 }
 104
 105 static inline struct raw_sock *raw_sk(const struct sock *sk)
 106 {
 107         return (struct raw_sock *)sk;
 108 }
 109
 110 static void raw_rcv(struct sk_buff *oskb, void *data)
 111 {
 112         struct sock *sk = (struct sock *)data;
 113         struct raw_sock *ro = raw_sk(sk);
 114         struct sockaddr_can *addr;
 115         struct sk_buff *skb;
 116         unsigned int *pflags;
 117
 118         /* check the received tx sock reference */
 119         if (!ro->recv_own_msgs && oskb->sk == sk)
 120                 return;
 121
 122         /* clone the given skb to be able to enqueue it into the rcv queue */
 123         skb = skb_clone(oskb, GFP_ATOMIC);
 124         if (!skb)
 125                 return;
 126
 127         /*
 128          *  Put the datagram to the queue so that raw_recvmsg() can
 129          *  get it from there.  We need to pass the interface index to
 130          *  raw_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 131          *  containing the interface index.
 132          */
 133
 134         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
 135         addr = (struct sockaddr_can *)skb->cb;
 136         memset(addr, 0, sizeof(*addr));
 137         addr->can_family  = AF_CAN;
 138         addr->can_ifindex = skb->dev->ifindex;
 139
 140         /* add CAN specific message flags for raw_recvmsg() */
 141         pflags = raw_flags(skb);
 142         *pflags = 0;
 143         if (oskb->sk)
 144                 *pflags |= MSG_DONTROUTE;
 145         if (oskb->sk == sk)
 146                 *pflags |= MSG_CONFIRM;
 147
 148         if (sock_queue_rcv_skb(sk, skb) < 0)
 149                 kfree_skb(skb);
 150 }
 151
 152 static int raw_enable_filters(struct net_device *dev, struct sock *sk,
 153                               struct can_filter *filter, int count)
 154 {
 155         int err = 0;
 156         int i;
 157
 158         for (i = 0; i < count; i++) {
 159                 err = can_rx_register(dev, filter[i].can_id,
 160                                       filter[i].can_mask,
 161                                       raw_rcv, sk, "raw");
 162                 if (err) {
 163                         /* clean up successfully registered filters */
 164                         while (--i >= 0)
 165                                 can_rx_unregister(dev, filter[i].can_id,
 166                                                   filter[i].can_mask,
 167                                                   raw_rcv, sk);
 168                         break;
 169                 }
 170         }
 171
 172         return err;
 173 }
 174
 175 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
 176                                 can_err_mask_t err_mask)
 177 {
 178         int err = 0;
 179
 180         if (err_mask)
 181                 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
 182                                       raw_rcv, sk, "raw");
 183
 184         return err;
 185 }
 186
 187 static void raw_disable_filters(struct net_device *dev, struct sock *sk,
 188                               struct can_filter *filter, int count)
 189 {
 190         int i;
 191
 192         for (i = 0; i < count; i++)
 193                 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
 194                                   raw_rcv, sk);
 195 }
 196
 197 static inline void raw_disable_errfilter(struct net_device *dev,
 198                                          struct sock *sk,
 199                                          can_err_mask_t err_mask)
 200
 201 {
 202         if (err_mask)
 203                 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
 204                                   raw_rcv, sk);
 205 }
 206
 207 static inline void raw_disable_allfilters(struct net_device *dev,
 208                                           struct sock *sk)
 209 {
 210         struct raw_sock *ro = raw_sk(sk);
 211
 212         raw_disable_filters(dev, sk, ro->filter, ro->count);
 213         raw_disable_errfilter(dev, sk, ro->err_mask);
 214 }
 215
 216 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
 217 {
 218         struct raw_sock *ro = raw_sk(sk);
 219         int err;
 220
 221         err = raw_enable_filters(dev, sk, ro->filter, ro->count);
 222         if (!err) {
 223                 err = raw_enable_errfilter(dev, sk, ro->err_mask);
 224                 if (err)
 225                         raw_disable_filters(dev, sk, ro->filter, ro->count);
 226         }
 227
 228         return err;
 229 }
 230
 231 static int raw_notifier(struct notifier_block *nb,
 232                         unsigned long msg, void *data)
 233 {
 234         struct net_device *dev = (struct net_device *)data;
 235         struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
 236         struct sock *sk = &ro->sk;
 237
 238         if (!net_eq(dev_net(dev), &init_net))
 239                 return NOTIFY_DONE;
 240
 241         if (dev->type != ARPHRD_CAN)
 242                 return NOTIFY_DONE;
 243
 244         if (ro->ifindex != dev->ifindex)
 245                 return NOTIFY_DONE;
 246
 247         switch (msg) {
 248
 249         case NETDEV_UNREGISTER:
 250                 lock_sock(sk);
 251                 /* remove current filters & unregister */
 252                 if (ro->bound)
 253                         raw_disable_allfilters(dev, sk);
 254
 255                 if (ro->count > 1)
 256                         kfree(ro->filter);
 257
 258                 ro->ifindex = 0;
 259                 ro->bound   = 0;
 260                 ro->count   = 0;
 261                 release_sock(sk);
 262
 263                 sk->sk_err = ENODEV;
 264                 if (!sock_flag(sk, SOCK_DEAD))
 265                         sk->sk_error_report(sk);
 266                 break;
 267
 268         case NETDEV_DOWN:
 269                 sk->sk_err = ENETDOWN;
 270                 if (!sock_flag(sk, SOCK_DEAD))
 271                         sk->sk_error_report(sk);
 272                 break;
 273         }
 274
 275         return NOTIFY_DONE;
 276 }
 277
 278 static int raw_init(struct sock *sk)
 279 {
 280         struct raw_sock *ro = raw_sk(sk);
 281
 282         ro->bound            = 0;
 283         ro->ifindex          = 0;
 284
 285         /* set default filter to single entry dfilter */
 286         ro->dfilter.can_id   = 0;
 287         ro->dfilter.can_mask = MASK_ALL;
 288         ro->filter           = &ro->dfilter;
 289         ro->count            = 1;
 290
 291         /* set default loopback behaviour */
 292         ro->loopback         = 1;
 293         ro->recv_own_msgs    = 0;
 294
 295         /* set notifier */
 296         ro->notifier.notifier_call = raw_notifier;
 297
 298         register_netdevice_notifier(&ro->notifier);
 299
 300         return 0;
 301 }
 302
 303 static int raw_release(struct socket *sock)
 304 {
 305         struct sock *sk = sock->sk;
 306         struct raw_sock *ro;
 307
 308         if (!sk)
 309                 return 0;
 310
 311         ro = raw_sk(sk);
 312
 313         unregister_netdevice_notifier(&ro->notifier);
 314
 315         lock_sock(sk);
 316
 317         /* remove current filters & unregister */
 318         if (ro->bound) {
 319                 if (ro->ifindex) {
 320                         struct net_device *dev;
 321
 322                         dev = dev_get_by_index(&init_net, ro->ifindex);
 323                         if (dev) {
 324                                 raw_disable_allfilters(dev, sk);
 325                                 dev_put(dev);
 326                         }
 327                 } else
 328                         raw_disable_allfilters(NULL, sk);
 329         }
 330
 331         if (ro->count > 1)
 332                 kfree(ro->filter);
 333
 334         ro->ifindex = 0;
 335         ro->bound   = 0;
 336         ro->count   = 0;
 337
 338         sock_orphan(sk);
 339         sock->sk = NULL;
 340
 341         release_sock(sk);
 342         sock_put(sk);
 343
 344         return 0;
 345 }
 346
 347 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 348 {
 349         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 350         struct sock *sk = sock->sk;
 351         struct raw_sock *ro = raw_sk(sk);
 352         int ifindex;
 353         int err = 0;
 354         int notify_enetdown = 0;
 355
 356         if (len < sizeof(*addr))
 357                 return -EINVAL;
 358
 359         lock_sock(sk);
 360
 361         if (ro->bound && addr->can_ifindex == ro->ifindex)
 362                 goto out;
 363
 364         if (addr->can_ifindex) {
 365                 struct net_device *dev;
 366
 367                 dev = dev_get_by_index(&init_net, addr->can_ifindex);
 368                 if (!dev) {
 369                         err = -ENODEV;
 370                         goto out;
 371                 }
 372                 if (dev->type != ARPHRD_CAN) {
 373                         dev_put(dev);
 374                         err = -ENODEV;
 375                         goto out;
 376                 }
 377                 if (!(dev->flags & IFF_UP))
 378                         notify_enetdown = 1;
 379
 380                 ifindex = dev->ifindex;
 381
 382                 /* filters set by default/setsockopt */
 383                 err = raw_enable_allfilters(dev, sk);
 384                 dev_put(dev);
 385         } else {
 386                 ifindex = 0;
 387
 388                 /* filters set by default/setsockopt */
 389                 err = raw_enable_allfilters(NULL, sk);
 390         }
 391
 392         if (!err) {
 393                 if (ro->bound) {
 394                         /* unregister old filters */
 395                         if (ro->ifindex) {
 396                                 struct net_device *dev;
 397
 398                                 dev = dev_get_by_index(&init_net, ro->ifindex);
 399                                 if (dev) {
 400                                         raw_disable_allfilters(dev, sk);
 401                                         dev_put(dev);
 402                                 }
 403                         } else
 404                                 raw_disable_allfilters(NULL, sk);
 405                 }
 406                 ro->ifindex = ifindex;
 407                 ro->bound = 1;
 408         }
 409
 410  out:
 411         release_sock(sk);
 412
 413         if (notify_enetdown) {
 414                 sk->sk_err = ENETDOWN;
 415                 if (!sock_flag(sk, SOCK_DEAD))
 416                         sk->sk_error_report(sk);
 417         }
 418
 419         return err;
 420 }
 421
 422 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
 423                        int *len, int peer)
 424 {
 425         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 426         struct sock *sk = sock->sk;
 427         struct raw_sock *ro = raw_sk(sk);
 428
 429         if (peer)
 430                 return -EOPNOTSUPP;
 431
 432         memset(addr, 0, sizeof(*addr));
 433         addr->can_family  = AF_CAN;
 434         addr->can_ifindex = ro->ifindex;
 435
 436         *len = sizeof(*addr);
 437
 438         return 0;
 439 }
 440
 441 static int raw_setsockopt(struct socket *sock, int level, int optname,
 442                           char __user *optval, unsigned int optlen)
 443 {
 444         struct sock *sk = sock->sk;
 445         struct raw_sock *ro = raw_sk(sk);
 446         struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
 447         struct can_filter sfilter;         /* single filter */
 448         struct net_device *dev = NULL;
 449         can_err_mask_t err_mask = 0;
 450         int count = 0;
 451         int err = 0;
 452
 453         if (level != SOL_CAN_RAW)
 454                 return -EINVAL;
 455
 456         switch (optname) {
 457
 458         case CAN_RAW_FILTER:
 459                 if (optlen % sizeof(struct can_filter) != 0)
 460                         return -EINVAL;
 461
 462                 count = optlen / sizeof(struct can_filter);
 463
 464                 if (count > 1) {
 465                         /* filter does not fit into dfilter => alloc space */
 466                         filter = memdup_user(optval, optlen);
 467                         if (IS_ERR(filter))
 468                                 return PTR_ERR(filter);
 469                 } else if (count == 1) {
 470                         if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
 471                                 return -EFAULT;
 472                 }
 473
 474                 lock_sock(sk);
 475
 476                 if (ro->bound && ro->ifindex)
 477                         dev = dev_get_by_index(&init_net, ro->ifindex);
 478
 479                 if (ro->bound) {
 480                         /* (try to) register the new filters */
 481                         if (count == 1)
 482                                 err = raw_enable_filters(dev, sk, &sfilter, 1);
 483                         else
 484                                 err = raw_enable_filters(dev, sk, filter,
 485                                                          count);
 486                         if (err) {
 487                                 if (count > 1)
 488                                         kfree(filter);
 489                                 goto out_fil;
 490                         }
 491
 492                         /* remove old filter registrations */
 493                         raw_disable_filters(dev, sk, ro->filter, ro->count);
 494                 }
 495
 496                 /* remove old filter space */
 497                 if (ro->count > 1)
 498                         kfree(ro->filter);
 499
 500                 /* link new filters to the socket */
 501                 if (count == 1) {
 502                         /* copy filter data for single filter */
 503                         ro->dfilter = sfilter;
 504                         filter = &ro->dfilter;
 505                 }
 506                 ro->filter = filter;
 507                 ro->count  = count;
 508
 509  out_fil:
 510                 if (dev)
 511                         dev_put(dev);
 512
 513                 release_sock(sk);
 514
 515                 break;
 516
 517         case CAN_RAW_ERR_FILTER:
 518                 if (optlen != sizeof(err_mask))
 519                         return -EINVAL;
 520
 521                 if (copy_from_user(&err_mask, optval, optlen))
 522                         return -EFAULT;
 523
 524                 err_mask &= CAN_ERR_MASK;
 525
 526                 lock_sock(sk);
 527
 528                 if (ro->bound && ro->ifindex)
 529                         dev = dev_get_by_index(&init_net, ro->ifindex);
 530
 531                 /* remove current error mask */
 532                 if (ro->bound) {
 533                         /* (try to) register the new err_mask */
 534                         err = raw_enable_errfilter(dev, sk, err_mask);
 535
 536                         if (err)
 537                                 goto out_err;
 538
 539                         /* remove old err_mask registration */
 540                         raw_disable_errfilter(dev, sk, ro->err_mask);
 541                 }
 542
 543                 /* link new err_mask to the socket */
 544                 ro->err_mask = err_mask;
 545
 546  out_err:
 547                 if (dev)
 548                         dev_put(dev);
 549
 550                 release_sock(sk);
 551
 552                 break;
 553
 554         case CAN_RAW_LOOPBACK:
 555                 if (optlen != sizeof(ro->loopback))
 556                         return -EINVAL;
 557
 558                 if (copy_from_user(&ro->loopback, optval, optlen))
 559                         return -EFAULT;
 560
 561                 break;
 562
 563         case CAN_RAW_RECV_OWN_MSGS:
 564                 if (optlen != sizeof(ro->recv_own_msgs))
 565                         return -EINVAL;
 566
 567                 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
 568                         return -EFAULT;
 569
 570                 break;
 571
 572         default:
 573                 return -ENOPROTOOPT;
 574         }
 575         return err;
 576 }
 577
 578 static int raw_getsockopt(struct socket *sock, int level, int optname,
 579                           char __user *optval, int __user *optlen)
 580 {
 581         struct sock *sk = sock->sk;
 582         struct raw_sock *ro = raw_sk(sk);
 583         int len;
 584         void *val;
 585         int err = 0;
 586
 587         if (level != SOL_CAN_RAW)
 588                 return -EINVAL;
 589         if (get_user(len, optlen))
 590                 return -EFAULT;
 591         if (len < 0)
 592                 return -EINVAL;
 593
 594         switch (optname) {
 595
 596         case CAN_RAW_FILTER:
 597                 lock_sock(sk);
 598                 if (ro->count > 0) {
 599                         int fsize = ro->count * sizeof(struct can_filter);
 600                         if (len > fsize)
 601                                 len = fsize;
 602                         if (copy_to_user(optval, ro->filter, len))
 603                                 err = -EFAULT;
 604                 } else
 605                         len = 0;
 606                 release_sock(sk);
 607
 608                 if (!err)
 609                         err = put_user(len, optlen);
 610                 return err;
 611
 612         case CAN_RAW_ERR_FILTER:
 613                 if (len > sizeof(can_err_mask_t))
 614                         len = sizeof(can_err_mask_t);
 615                 val = &ro->err_mask;
 616                 break;
 617
 618         case CAN_RAW_LOOPBACK:
 619                 if (len > sizeof(int))
 620                         len = sizeof(int);
 621                 val = &ro->loopback;
 622                 break;
 623
 624         case CAN_RAW_RECV_OWN_MSGS:
 625                 if (len > sizeof(int))
 626                         len = sizeof(int);
 627                 val = &ro->recv_own_msgs;
 628                 break;
 629
 630         default:
 631                 return -ENOPROTOOPT;
 632         }
 633
 634         if (put_user(len, optlen))
 635                 return -EFAULT;
 636         if (copy_to_user(optval, val, len))
 637                 return -EFAULT;
 638         return 0;
 639 }
 640
 641 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 642                        struct msghdr *msg, size_t size)
 643 {
 644         struct sock *sk = sock->sk;
 645         struct raw_sock *ro = raw_sk(sk);
 646         struct sk_buff *skb;
 647         struct net_device *dev;
 648         int ifindex;
 649         int err;
 650
 651         if (msg->msg_name) {
 652                 struct sockaddr_can *addr =
 653                         (struct sockaddr_can *)msg->msg_name;
 654
 655                 if (msg->msg_namelen < sizeof(*addr))
 656                         return -EINVAL;
 657
 658                 if (addr->can_family != AF_CAN)
 659                         return -EINVAL;
 660
 661                 ifindex = addr->can_ifindex;
 662         } else
 663                 ifindex = ro->ifindex;
 664
 665         if (size != sizeof(struct can_frame))
 666                 return -EINVAL;
 667
 668         dev = dev_get_by_index(&init_net, ifindex);
 669         if (!dev)
 670                 return -ENXIO;
 671
 672         skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
 673                                   &err);
 674         if (!skb)
 675                 goto put_dev;
 676
 677         err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 678         if (err < 0)
 679                 goto free_skb;
 680         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
 681         if (err < 0)
 682                 goto free_skb;
 683
 684         /* to be able to check the received tx sock reference in raw_rcv() */
 685         skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF;
 686
 687         skb->dev = dev;
 688         skb->sk  = sk;
 689
 690         err = can_send(skb, ro->loopback);
 691
 692         dev_put(dev);
 693
 694         if (err)
 695                 goto send_failed;
 696
 697         return size;
 698
 699 free_skb:
 700         kfree_skb(skb);
 701 put_dev:
 702         dev_put(dev);
 703 send_failed:
 704         return err;
 705 }
 706
 707 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 708                        struct msghdr *msg, size_t size, int flags)
 709 {
 710         struct sock *sk = sock->sk;
 711         struct sk_buff *skb;
 712         int err = 0;
 713         int noblock;
 714
 715         noblock =  flags & MSG_DONTWAIT;
 716         flags   &= ~MSG_DONTWAIT;
 717
 718         skb = skb_recv_datagram(sk, flags, noblock, &err);
 719         if (!skb)
 720                 return err;
 721
 722         if (size < skb->len)
 723                 msg->msg_flags |= MSG_TRUNC;
 724         else
 725                 size = skb->len;
 726
 727         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
 728         if (err < 0) {
 729                 skb_free_datagram(sk, skb);
 730                 return err;
 731         }
 732
 733         sock_recv_ts_and_drops(msg, sk, skb);
 734
 735         if (msg->msg_name) {
 736                 msg->msg_namelen = sizeof(struct sockaddr_can);
 737                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 738         }
 739
 740         /* assign the flags that have been recorded in raw_rcv() */
 741         msg->msg_flags |= *(raw_flags(skb));
 742
 743         skb_free_datagram(sk, skb);
 744
 745         return size;
 746 }
 747
 748 static const struct proto_ops raw_ops = {
 749         .family        = PF_CAN,
 750         .release       = raw_release,
 751         .bind          = raw_bind,
 752         .connect       = sock_no_connect,
 753         .socketpair    = sock_no_socketpair,
 754         .accept        = sock_no_accept,
 755         .getname       = raw_getname,
 756         .poll          = datagram_poll,
 757         .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
 758         .listen        = sock_no_listen,
 759         .shutdown      = sock_no_shutdown,
 760         .setsockopt    = raw_setsockopt,
 761         .getsockopt    = raw_getsockopt,
 762         .sendmsg       = raw_sendmsg,
 763         .recvmsg       = raw_recvmsg,
 764         .mmap          = sock_no_mmap,
 765         .sendpage      = sock_no_sendpage,
 766 };
 767
 768 static struct proto raw_proto __read_mostly = {
 769         .name       = "CAN_RAW",
 770         .owner      = THIS_MODULE,
 771         .obj_size   = sizeof(struct raw_sock),
 772         .init       = raw_init,
 773 };
 774
 775 static const struct can_proto raw_can_proto = {
 776         .type       = SOCK_RAW,
 777         .protocol   = CAN_RAW,
 778         .ops        = &raw_ops,
 779         .prot       = &raw_proto,
 780 };
 781
 782 static __init int raw_module_init(void)
 783 {
 784         int err;
 785
 786         printk(banner);
 787
 788         err = can_proto_register(&raw_can_proto);
 789         if (err < 0)
 790                 printk(KERN_ERR "can: registration of raw protocol failed\n");
 791
 792         return err;
 793 }
 794
 795 static __exit void raw_module_exit(void)
 796 {
 797         can_proto_unregister(&raw_can_proto);
 798 }
 799
 800 module_init(raw_module_init);
 801 module_exit(raw_module_exit);