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 __initconst 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 fd_frames;
  86         int count;                 /* number of active filters */
  87         struct can_filter dfilter; /* default/single filter */
  88         struct can_filter *filter; /* pointer to filter(s) */
  89         can_err_mask_t err_mask;
  90 };
  91
  92 /*
  93  * Return pointer to store the extra msg flags for raw_recvmsg().
  94  * We use the space of one unsigned int beyond the 'struct sockaddr_can'
  95  * in skb->cb.
  96  */
  97 static inline unsigned int *raw_flags(struct sk_buff *skb)
  98 {
  99         BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
 100                                          sizeof(unsigned int)));
 101
 102         /* return pointer after struct sockaddr_can */
 103         return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
 104 }
 105
 106 static inline struct raw_sock *raw_sk(const struct sock *sk)
 107 {
 108         return (struct raw_sock *)sk;
 109 }
 110
 111 static void raw_rcv(struct sk_buff *oskb, void *data)
 112 {
 113         struct sock *sk = (struct sock *)data;
 114         struct raw_sock *ro = raw_sk(sk);
 115         struct sockaddr_can *addr;
 116         struct sk_buff *skb;
 117         unsigned int *pflags;
 118
 119         /* check the received tx sock reference */
 120         if (!ro->recv_own_msgs && oskb->sk == sk)
 121                 return;
 122
 123         /* do not pass frames with DLC > 8 to a legacy socket */
 124         if (!ro->fd_frames) {
 125                 struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;
 126
 127                 if (unlikely(cfd->len > CAN_MAX_DLEN))
 128                         return;
 129         }
 130
 131         /* clone the given skb to be able to enqueue it into the rcv queue */
 132         skb = skb_clone(oskb, GFP_ATOMIC);
 133         if (!skb)
 134                 return;
 135
 136         /*
 137          *  Put the datagram to the queue so that raw_recvmsg() can
 138          *  get it from there.  We need to pass the interface index to
 139          *  raw_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 140          *  containing the interface index.
 141          */
 142
 143         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
 144         addr = (struct sockaddr_can *)skb->cb;
 145         memset(addr, 0, sizeof(*addr));
 146         addr->can_family  = AF_CAN;
 147         addr->can_ifindex = skb->dev->ifindex;
 148
 149         /* add CAN specific message flags for raw_recvmsg() */
 150         pflags = raw_flags(skb);
 151         *pflags = 0;
 152         if (oskb->sk)
 153                 *pflags |= MSG_DONTROUTE;
 154         if (oskb->sk == sk)
 155                 *pflags |= MSG_CONFIRM;
 156
 157         if (sock_queue_rcv_skb(sk, skb) < 0)
 158                 kfree_skb(skb);
 159 }
 160
 161 static int raw_enable_filters(struct net_device *dev, struct sock *sk,
 162                               struct can_filter *filter, int count)
 163 {
 164         int err = 0;
 165         int i;
 166
 167         for (i = 0; i < count; i++) {
 168                 err = can_rx_register(dev, filter[i].can_id,
 169                                       filter[i].can_mask,
 170                                       raw_rcv, sk, "raw");
 171                 if (err) {
 172                         /* clean up successfully registered filters */
 173                         while (--i >= 0)
 174                                 can_rx_unregister(dev, filter[i].can_id,
 175                                                   filter[i].can_mask,
 176                                                   raw_rcv, sk);
 177                         break;
 178                 }
 179         }
 180
 181         return err;
 182 }
 183
 184 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
 185                                 can_err_mask_t err_mask)
 186 {
 187         int err = 0;
 188
 189         if (err_mask)
 190                 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
 191                                       raw_rcv, sk, "raw");
 192
 193         return err;
 194 }
 195
 196 static void raw_disable_filters(struct net_device *dev, struct sock *sk,
 197                               struct can_filter *filter, int count)
 198 {
 199         int i;
 200
 201         for (i = 0; i < count; i++)
 202                 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
 203                                   raw_rcv, sk);
 204 }
 205
 206 static inline void raw_disable_errfilter(struct net_device *dev,
 207                                          struct sock *sk,
 208                                          can_err_mask_t err_mask)
 209
 210 {
 211         if (err_mask)
 212                 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
 213                                   raw_rcv, sk);
 214 }
 215
 216 static inline void raw_disable_allfilters(struct net_device *dev,
 217                                           struct sock *sk)
 218 {
 219         struct raw_sock *ro = raw_sk(sk);
 220
 221         raw_disable_filters(dev, sk, ro->filter, ro->count);
 222         raw_disable_errfilter(dev, sk, ro->err_mask);
 223 }
 224
 225 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
 226 {
 227         struct raw_sock *ro = raw_sk(sk);
 228         int err;
 229
 230         err = raw_enable_filters(dev, sk, ro->filter, ro->count);
 231         if (!err) {
 232                 err = raw_enable_errfilter(dev, sk, ro->err_mask);
 233                 if (err)
 234                         raw_disable_filters(dev, sk, ro->filter, ro->count);
 235         }
 236
 237         return err;
 238 }
 239
 240 static int raw_notifier(struct notifier_block *nb,
 241                         unsigned long msg, void *data)
 242 {
 243         struct net_device *dev = (struct net_device *)data;
 244         struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
 245         struct sock *sk = &ro->sk;
 246
 247         if (!net_eq(dev_net(dev), &init_net))
 248                 return NOTIFY_DONE;
 249
 250         if (dev->type != ARPHRD_CAN)
 251                 return NOTIFY_DONE;
 252
 253         if (ro->ifindex != dev->ifindex)
 254                 return NOTIFY_DONE;
 255
 256         switch (msg) {
 257
 258         case NETDEV_UNREGISTER:
 259                 lock_sock(sk);
 260                 /* remove current filters & unregister */
 261                 if (ro->bound)
 262                         raw_disable_allfilters(dev, sk);
 263
 264                 if (ro->count > 1)
 265                         kfree(ro->filter);
 266
 267                 ro->ifindex = 0;
 268                 ro->bound   = 0;
 269                 ro->count   = 0;
 270                 release_sock(sk);
 271
 272                 sk->sk_err = ENODEV;
 273                 if (!sock_flag(sk, SOCK_DEAD))
 274                         sk->sk_error_report(sk);
 275                 break;
 276
 277         case NETDEV_DOWN:
 278                 sk->sk_err = ENETDOWN;
 279                 if (!sock_flag(sk, SOCK_DEAD))
 280                         sk->sk_error_report(sk);
 281                 break;
 282         }
 283
 284         return NOTIFY_DONE;
 285 }
 286
 287 static int raw_init(struct sock *sk)
 288 {
 289         struct raw_sock *ro = raw_sk(sk);
 290
 291         ro->bound            = 0;
 292         ro->ifindex          = 0;
 293
 294         /* set default filter to single entry dfilter */
 295         ro->dfilter.can_id   = 0;
 296         ro->dfilter.can_mask = MASK_ALL;
 297         ro->filter           = &ro->dfilter;
 298         ro->count            = 1;
 299
 300         /* set default loopback behaviour */
 301         ro->loopback         = 1;
 302         ro->recv_own_msgs    = 0;
 303         ro->fd_frames        = 0;
 304
 305         /* set notifier */
 306         ro->notifier.notifier_call = raw_notifier;
 307
 308         register_netdevice_notifier(&ro->notifier);
 309
 310         return 0;
 311 }
 312
 313 static int raw_release(struct socket *sock)
 314 {
 315         struct sock *sk = sock->sk;
 316         struct raw_sock *ro;
 317
 318         if (!sk)
 319                 return 0;
 320
 321         ro = raw_sk(sk);
 322
 323         unregister_netdevice_notifier(&ro->notifier);
 324
 325         lock_sock(sk);
 326
 327         /* remove current filters & unregister */
 328         if (ro->bound) {
 329                 if (ro->ifindex) {
 330                         struct net_device *dev;
 331
 332                         dev = dev_get_by_index(&init_net, ro->ifindex);
 333                         if (dev) {
 334                                 raw_disable_allfilters(dev, sk);
 335                                 dev_put(dev);
 336                         }
 337                 } else
 338                         raw_disable_allfilters(NULL, sk);
 339         }
 340
 341         if (ro->count > 1)
 342                 kfree(ro->filter);
 343
 344         ro->ifindex = 0;
 345         ro->bound   = 0;
 346         ro->count   = 0;
 347
 348         sock_orphan(sk);
 349         sock->sk = NULL;
 350
 351         release_sock(sk);
 352         sock_put(sk);
 353
 354         return 0;
 355 }
 356
 357 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 358 {
 359         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 360         struct sock *sk = sock->sk;
 361         struct raw_sock *ro = raw_sk(sk);
 362         int ifindex;
 363         int err = 0;
 364         int notify_enetdown = 0;
 365
 366         if (len < sizeof(*addr))
 367                 return -EINVAL;
 368
 369         lock_sock(sk);
 370
 371         if (ro->bound && addr->can_ifindex == ro->ifindex)
 372                 goto out;
 373
 374         if (addr->can_ifindex) {
 375                 struct net_device *dev;
 376
 377                 dev = dev_get_by_index(&init_net, addr->can_ifindex);
 378                 if (!dev) {
 379                         err = -ENODEV;
 380                         goto out;
 381                 }
 382                 if (dev->type != ARPHRD_CAN) {
 383                         dev_put(dev);
 384                         err = -ENODEV;
 385                         goto out;
 386                 }
 387                 if (!(dev->flags & IFF_UP))
 388                         notify_enetdown = 1;
 389
 390                 ifindex = dev->ifindex;
 391
 392                 /* filters set by default/setsockopt */
 393                 err = raw_enable_allfilters(dev, sk);
 394                 dev_put(dev);
 395         } else {
 396                 ifindex = 0;
 397
 398                 /* filters set by default/setsockopt */
 399                 err = raw_enable_allfilters(NULL, sk);
 400         }
 401
 402         if (!err) {
 403                 if (ro->bound) {
 404                         /* unregister old filters */
 405                         if (ro->ifindex) {
 406                                 struct net_device *dev;
 407
 408                                 dev = dev_get_by_index(&init_net, ro->ifindex);
 409                                 if (dev) {
 410                                         raw_disable_allfilters(dev, sk);
 411                                         dev_put(dev);
 412                                 }
 413                         } else
 414                                 raw_disable_allfilters(NULL, sk);
 415                 }
 416                 ro->ifindex = ifindex;
 417                 ro->bound = 1;
 418         }
 419
 420  out:
 421         release_sock(sk);
 422
 423         if (notify_enetdown) {
 424                 sk->sk_err = ENETDOWN;
 425                 if (!sock_flag(sk, SOCK_DEAD))
 426                         sk->sk_error_report(sk);
 427         }
 428
 429         return err;
 430 }
 431
 432 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
 433                        int *len, int peer)
 434 {
 435         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 436         struct sock *sk = sock->sk;
 437         struct raw_sock *ro = raw_sk(sk);
 438
 439         if (peer)
 440                 return -EOPNOTSUPP;
 441
 442         memset(addr, 0, sizeof(*addr));
 443         addr->can_family  = AF_CAN;
 444         addr->can_ifindex = ro->ifindex;
 445
 446         *len = sizeof(*addr);
 447
 448         return 0;
 449 }
 450
 451 static int raw_setsockopt(struct socket *sock, int level, int optname,
 452                           char __user *optval, unsigned int optlen)
 453 {
 454         struct sock *sk = sock->sk;
 455         struct raw_sock *ro = raw_sk(sk);
 456         struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
 457         struct can_filter sfilter;         /* single filter */
 458         struct net_device *dev = NULL;
 459         can_err_mask_t err_mask = 0;
 460         int count = 0;
 461         int err = 0;
 462
 463         if (level != SOL_CAN_RAW)
 464                 return -EINVAL;
 465
 466         switch (optname) {
 467
 468         case CAN_RAW_FILTER:
 469                 if (optlen % sizeof(struct can_filter) != 0)
 470                         return -EINVAL;
 471
 472                 count = optlen / sizeof(struct can_filter);
 473
 474                 if (count > 1) {
 475                         /* filter does not fit into dfilter => alloc space */
 476                         filter = memdup_user(optval, optlen);
 477                         if (IS_ERR(filter))
 478                                 return PTR_ERR(filter);
 479                 } else if (count == 1) {
 480                         if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
 481                                 return -EFAULT;
 482                 }
 483
 484                 lock_sock(sk);
 485
 486                 if (ro->bound && ro->ifindex)
 487                         dev = dev_get_by_index(&init_net, ro->ifindex);
 488
 489                 if (ro->bound) {
 490                         /* (try to) register the new filters */
 491                         if (count == 1)
 492                                 err = raw_enable_filters(dev, sk, &sfilter, 1);
 493                         else
 494                                 err = raw_enable_filters(dev, sk, filter,
 495                                                          count);
 496                         if (err) {
 497                                 if (count > 1)
 498                                         kfree(filter);
 499                                 goto out_fil;
 500                         }
 501
 502                         /* remove old filter registrations */
 503                         raw_disable_filters(dev, sk, ro->filter, ro->count);
 504                 }
 505
 506                 /* remove old filter space */
 507                 if (ro->count > 1)
 508                         kfree(ro->filter);
 509
 510                 /* link new filters to the socket */
 511                 if (count == 1) {
 512                         /* copy filter data for single filter */
 513                         ro->dfilter = sfilter;
 514                         filter = &ro->dfilter;
 515                 }
 516                 ro->filter = filter;
 517                 ro->count  = count;
 518
 519  out_fil:
 520                 if (dev)
 521                         dev_put(dev);
 522
 523                 release_sock(sk);
 524
 525                 break;
 526
 527         case CAN_RAW_ERR_FILTER:
 528                 if (optlen != sizeof(err_mask))
 529                         return -EINVAL;
 530
 531                 if (copy_from_user(&err_mask, optval, optlen))
 532                         return -EFAULT;
 533
 534                 err_mask &= CAN_ERR_MASK;
 535
 536                 lock_sock(sk);
 537
 538                 if (ro->bound && ro->ifindex)
 539                         dev = dev_get_by_index(&init_net, ro->ifindex);
 540
 541                 /* remove current error mask */
 542                 if (ro->bound) {
 543                         /* (try to) register the new err_mask */
 544                         err = raw_enable_errfilter(dev, sk, err_mask);
 545
 546                         if (err)
 547                                 goto out_err;
 548
 549                         /* remove old err_mask registration */
 550                         raw_disable_errfilter(dev, sk, ro->err_mask);
 551                 }
 552
 553                 /* link new err_mask to the socket */
 554                 ro->err_mask = err_mask;
 555
 556  out_err:
 557                 if (dev)
 558                         dev_put(dev);
 559
 560                 release_sock(sk);
 561
 562                 break;
 563
 564         case CAN_RAW_LOOPBACK:
 565                 if (optlen != sizeof(ro->loopback))
 566                         return -EINVAL;
 567
 568                 if (copy_from_user(&ro->loopback, optval, optlen))
 569                         return -EFAULT;
 570
 571                 break;
 572
 573         case CAN_RAW_RECV_OWN_MSGS:
 574                 if (optlen != sizeof(ro->recv_own_msgs))
 575                         return -EINVAL;
 576
 577                 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
 578                         return -EFAULT;
 579
 580                 break;
 581
 582         case CAN_RAW_FD_FRAMES:
 583                 if (optlen != sizeof(ro->fd_frames))
 584                         return -EINVAL;
 585
 586                 if (copy_from_user(&ro->fd_frames, optval, optlen))
 587                         return -EFAULT;
 588
 589                 break;
 590
 591         default:
 592                 return -ENOPROTOOPT;
 593         }
 594         return err;
 595 }
 596
 597 static int raw_getsockopt(struct socket *sock, int level, int optname,
 598                           char __user *optval, int __user *optlen)
 599 {
 600         struct sock *sk = sock->sk;
 601         struct raw_sock *ro = raw_sk(sk);
 602         int len;
 603         void *val;
 604         int err = 0;
 605
 606         if (level != SOL_CAN_RAW)
 607                 return -EINVAL;
 608         if (get_user(len, optlen))
 609                 return -EFAULT;
 610         if (len < 0)
 611                 return -EINVAL;
 612
 613         switch (optname) {
 614
 615         case CAN_RAW_FILTER:
 616                 lock_sock(sk);
 617                 if (ro->count > 0) {
 618                         int fsize = ro->count * sizeof(struct can_filter);
 619                         if (len > fsize)
 620                                 len = fsize;
 621                         if (copy_to_user(optval, ro->filter, len))
 622                                 err = -EFAULT;
 623                 } else
 624                         len = 0;
 625                 release_sock(sk);
 626
 627                 if (!err)
 628                         err = put_user(len, optlen);
 629                 return err;
 630
 631         case CAN_RAW_ERR_FILTER:
 632                 if (len > sizeof(can_err_mask_t))
 633                         len = sizeof(can_err_mask_t);
 634                 val = &ro->err_mask;
 635                 break;
 636
 637         case CAN_RAW_LOOPBACK:
 638                 if (len > sizeof(int))
 639                         len = sizeof(int);
 640                 val = &ro->loopback;
 641                 break;
 642
 643         case CAN_RAW_RECV_OWN_MSGS:
 644                 if (len > sizeof(int))
 645                         len = sizeof(int);
 646                 val = &ro->recv_own_msgs;
 647                 break;
 648
 649         case CAN_RAW_FD_FRAMES:
 650                 if (len > sizeof(int))
 651                         len = sizeof(int);
 652                 val = &ro->fd_frames;
 653                 break;
 654
 655         default:
 656                 return -ENOPROTOOPT;
 657         }
 658
 659         if (put_user(len, optlen))
 660                 return -EFAULT;
 661         if (copy_to_user(optval, val, len))
 662                 return -EFAULT;
 663         return 0;
 664 }
 665
 666 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 667                        struct msghdr *msg, size_t size)
 668 {
 669         struct sock *sk = sock->sk;
 670         struct raw_sock *ro = raw_sk(sk);
 671         struct sk_buff *skb;
 672         struct net_device *dev;
 673         int ifindex;
 674         int err;
 675
 676         if (msg->msg_name) {
 677                 struct sockaddr_can *addr =
 678                         (struct sockaddr_can *)msg->msg_name;
 679
 680                 if (msg->msg_namelen < sizeof(*addr))
 681                         return -EINVAL;
 682
 683                 if (addr->can_family != AF_CAN)
 684                         return -EINVAL;
 685
 686                 ifindex = addr->can_ifindex;
 687         } else
 688                 ifindex = ro->ifindex;
 689
 690         if (ro->fd_frames) {
 691                 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
 692                         return -EINVAL;
 693         } else {
 694                 if (unlikely(size != CAN_MTU))
 695                         return -EINVAL;
 696         }
 697
 698         dev = dev_get_by_index(&init_net, ifindex);
 699         if (!dev)
 700                 return -ENXIO;
 701
 702         skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
 703                                   &err);
 704         if (!skb)
 705                 goto put_dev;
 706
 707         err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 708         if (err < 0)
 709                 goto free_skb;
 710         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
 711         if (err < 0)
 712                 goto free_skb;
 713
 714         skb->dev = dev;
 715         skb->sk  = sk;
 716
 717         err = can_send(skb, ro->loopback);
 718
 719         dev_put(dev);
 720
 721         if (err)
 722                 goto send_failed;
 723
 724         return size;
 725
 726 free_skb:
 727         kfree_skb(skb);
 728 put_dev:
 729         dev_put(dev);
 730 send_failed:
 731         return err;
 732 }
 733
 734 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 735                        struct msghdr *msg, size_t size, int flags)
 736 {
 737         struct sock *sk = sock->sk;
 738         struct raw_sock *ro = raw_sk(sk);
 739         struct sk_buff *skb;
 740         int rxmtu;
 741         int err = 0;
 742         int noblock;
 743
 744         noblock =  flags & MSG_DONTWAIT;
 745         flags   &= ~MSG_DONTWAIT;
 746
 747         skb = skb_recv_datagram(sk, flags, noblock, &err);
 748         if (!skb)
 749                 return err;
 750
 751         /*
 752          * when serving a legacy socket the DLC <= 8 is already checked inside
 753          * raw_rcv(). Now check if we need to pass a canfd_frame to a legacy
 754          * socket and cut the possible CANFD_MTU/CAN_MTU length to CAN_MTU
 755          */
 756         if (!ro->fd_frames)
 757                 rxmtu = CAN_MTU;
 758         else
 759                 rxmtu = skb->len;
 760
 761         if (size < rxmtu)
 762                 msg->msg_flags |= MSG_TRUNC;
 763         else
 764                 size = rxmtu;
 765
 766         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
 767         if (err < 0) {
 768                 skb_free_datagram(sk, skb);
 769                 return err;
 770         }
 771
 772         sock_recv_ts_and_drops(msg, sk, skb);
 773
 774         if (msg->msg_name) {
 775                 msg->msg_namelen = sizeof(struct sockaddr_can);
 776                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 777         }
 778
 779         /* assign the flags that have been recorded in raw_rcv() */
 780         msg->msg_flags |= *(raw_flags(skb));
 781
 782         skb_free_datagram(sk, skb);
 783
 784         return size;
 785 }
 786
 787 static const struct proto_ops raw_ops = {
 788         .family        = PF_CAN,
 789         .release       = raw_release,
 790         .bind          = raw_bind,
 791         .connect       = sock_no_connect,
 792         .socketpair    = sock_no_socketpair,
 793         .accept        = sock_no_accept,
 794         .getname       = raw_getname,
 795         .poll          = datagram_poll,
 796         .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
 797         .listen        = sock_no_listen,
 798         .shutdown      = sock_no_shutdown,
 799         .setsockopt    = raw_setsockopt,
 800         .getsockopt    = raw_getsockopt,
 801         .sendmsg       = raw_sendmsg,
 802         .recvmsg       = raw_recvmsg,
 803         .mmap          = sock_no_mmap,
 804         .sendpage      = sock_no_sendpage,
 805 };
 806
 807 static struct proto raw_proto __read_mostly = {
 808         .name       = "CAN_RAW",
 809         .owner      = THIS_MODULE,
 810         .obj_size   = sizeof(struct raw_sock),
 811         .init       = raw_init,
 812 };
 813
 814 static const struct can_proto raw_can_proto = {
 815         .type       = SOCK_RAW,
 816         .protocol   = CAN_RAW,
 817         .ops        = &raw_ops,
 818         .prot       = &raw_proto,
 819 };
 820
 821 static __init int raw_module_init(void)
 822 {
 823         int err;
 824
 825         printk(banner);
 826
 827         err = can_proto_register(&raw_can_proto);
 828         if (err < 0)
 829                 printk(KERN_ERR "can: registration of raw protocol failed\n");
 830
 831         return err;
 832 }
 833
 834 static __exit void raw_module_exit(void)
 835 {
 836         can_proto_unregister(&raw_can_proto);
 837 }
 838
 839 module_init(raw_module_init);
 840 module_exit(raw_module_exit);