root/net/can/raw.c

DEFINITIONS

1. raw_flags
2. raw_sk
3. raw_rcv
4. raw_enable_filters
5. raw_enable_errfilter
6. raw_disable_filters
7. raw_disable_errfilter
8. raw_disable_allfilters
9. raw_enable_allfilters
10. raw_notifier
11. raw_init
12. raw_release
13. raw_bind
14. raw_getname
15. raw_setsockopt
16. raw_getsockopt
17. raw_sendmsg
18. raw_recvmsg
19. raw_sock_no_ioctlcmd
20. raw_module_init
21. raw_module_exit

   1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
   2 /* raw.c - Raw sockets for protocol family CAN
   3  *
   4  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of Volkswagen nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * Alternatively, provided that this notice is retained in full, this
  20  * software may be distributed under the terms of the GNU General
  21  * Public License ("GPL") version 2, in which case the provisions of the
  22  * GPL apply INSTEAD OF those given above.
  23  *
  24  * The provided data structures and external interfaces from this code
  25  * are not restricted to be used by modules with a GPL compatible license.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  38  * DAMAGE.
  39  *
  40  */
  41 
  42 #include <linux/module.h>
  43 #include <linux/init.h>
  44 #include <linux/uio.h>
  45 #include <linux/net.h>
  46 #include <linux/slab.h>
  47 #include <linux/netdevice.h>
  48 #include <linux/socket.h>
  49 #include <linux/if_arp.h>
  50 #include <linux/skbuff.h>
  51 #include <linux/can.h>
  52 #include <linux/can/core.h>
  53 #include <linux/can/skb.h>
  54 #include <linux/can/raw.h>
  55 #include <net/sock.h>
  56 #include <net/net_namespace.h>
  57 
  58 #define CAN_RAW_VERSION CAN_VERSION
  59 
  60 MODULE_DESCRIPTION("PF_CAN raw protocol");
  61 MODULE_LICENSE("Dual BSD/GPL");
  62 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
  63 MODULE_ALIAS("can-proto-1");
  64 
  65 #define MASK_ALL 0
  66 
  67 /* A raw socket has a list of can_filters attached to it, each receiving
  68  * the CAN frames matching that filter.  If the filter list is empty,
  69  * no CAN frames will be received by the socket.  The default after
  70  * opening the socket, is to have one filter which receives all frames.
  71  * The filter list is allocated dynamically with the exception of the
  72  * list containing only one item.  This common case is optimized by
  73  * storing the single filter in dfilter, to avoid using dynamic memory.
  74  */
  75 
  76 struct uniqframe {
  77         int skbcnt;
  78         const struct sk_buff *skb;
  79         unsigned int join_rx_count;
  80 };
  81 
  82 struct raw_sock {
  83         struct sock sk;
  84         int bound;
  85         int ifindex;
  86         struct notifier_block notifier;
  87         int loopback;
  88         int recv_own_msgs;
  89         int fd_frames;
  90         int join_filters;
  91         int count;                 /* number of active filters */
  92         struct can_filter dfilter; /* default/single filter */
  93         struct can_filter *filter; /* pointer to filter(s) */
  94         can_err_mask_t err_mask;
  95         struct uniqframe __percpu *uniq;
  96 };
  97 
  98 /* Return pointer to store the extra msg flags for raw_recvmsg().
  99  * We use the space of one unsigned int beyond the 'struct sockaddr_can'
 100  * in skb->cb.
 101  */
 102 static inline unsigned int *raw_flags(struct sk_buff *skb)
 103 {
 104         sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
 105                                sizeof(unsigned int));
 106 
 107         /* return pointer after struct sockaddr_can */
 108         return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
 109 }
 110 
 111 static inline struct raw_sock *raw_sk(const struct sock *sk)
 112 {
 113         return (struct raw_sock *)sk;
 114 }
 115 
 116 static void raw_rcv(struct sk_buff *oskb, void *data)
 117 {
 118         struct sock *sk = (struct sock *)data;
 119         struct raw_sock *ro = raw_sk(sk);
 120         struct sockaddr_can *addr;
 121         struct sk_buff *skb;
 122         unsigned int *pflags;
 123 
 124         /* check the received tx sock reference */
 125         if (!ro->recv_own_msgs && oskb->sk == sk)
 126                 return;
 127 
 128         /* do not pass non-CAN2.0 frames to a legacy socket */
 129         if (!ro->fd_frames && oskb->len != CAN_MTU)
 130                 return;
 131 
 132         /* eliminate multiple filter matches for the same skb */
 133         if (this_cpu_ptr(ro->uniq)->skb == oskb &&
 134             this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
 135                 if (ro->join_filters) {
 136                         this_cpu_inc(ro->uniq->join_rx_count);
 137                         /* drop frame until all enabled filters matched */
 138                         if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
 139                                 return;
 140                 } else {
 141                         return;
 142                 }
 143         } else {
 144                 this_cpu_ptr(ro->uniq)->skb = oskb;
 145                 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
 146                 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
 147                 /* drop first frame to check all enabled filters? */
 148                 if (ro->join_filters && ro->count > 1)
 149                         return;
 150         }
 151 
 152         /* clone the given skb to be able to enqueue it into the rcv queue */
 153         skb = skb_clone(oskb, GFP_ATOMIC);
 154         if (!skb)
 155                 return;
 156 
 157         /*  Put the datagram to the queue so that raw_recvmsg() can
 158          *  get it from there.  We need to pass the interface index to
 159          *  raw_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 160          *  containing the interface index.
 161          */
 162 
 163         sock_skb_cb_check_size(sizeof(struct sockaddr_can));
 164         addr = (struct sockaddr_can *)skb->cb;
 165         memset(addr, 0, sizeof(*addr));
 166         addr->can_family  = AF_CAN;
 167         addr->can_ifindex = skb->dev->ifindex;
 168 
 169         /* add CAN specific message flags for raw_recvmsg() */
 170         pflags = raw_flags(skb);
 171         *pflags = 0;
 172         if (oskb->sk)
 173                 *pflags |= MSG_DONTROUTE;
 174         if (oskb->sk == sk)
 175                 *pflags |= MSG_CONFIRM;
 176 
 177         if (sock_queue_rcv_skb(sk, skb) < 0)
 178                 kfree_skb(skb);
 179 }
 180 
 181 static int raw_enable_filters(struct net *net, struct net_device *dev,
 182                               struct sock *sk, struct can_filter *filter,
 183                               int count)
 184 {
 185         int err = 0;
 186         int i;
 187 
 188         for (i = 0; i < count; i++) {
 189                 err = can_rx_register(net, dev, filter[i].can_id,
 190                                       filter[i].can_mask,
 191                                       raw_rcv, sk, "raw", sk);
 192                 if (err) {
 193                         /* clean up successfully registered filters */
 194                         while (--i >= 0)
 195                                 can_rx_unregister(net, dev, filter[i].can_id,
 196                                                   filter[i].can_mask,
 197                                                   raw_rcv, sk);
 198                         break;
 199                 }
 200         }
 201 
 202         return err;
 203 }
 204 
 205 static int raw_enable_errfilter(struct net *net, struct net_device *dev,
 206                                 struct sock *sk, can_err_mask_t err_mask)
 207 {
 208         int err = 0;
 209 
 210         if (err_mask)
 211                 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
 212                                       raw_rcv, sk, "raw", sk);
 213 
 214         return err;
 215 }
 216 
 217 static void raw_disable_filters(struct net *net, struct net_device *dev,
 218                                 struct sock *sk, struct can_filter *filter,
 219                                 int count)
 220 {
 221         int i;
 222 
 223         for (i = 0; i < count; i++)
 224                 can_rx_unregister(net, dev, filter[i].can_id,
 225                                   filter[i].can_mask, raw_rcv, sk);
 226 }
 227 
 228 static inline void raw_disable_errfilter(struct net *net,
 229                                          struct net_device *dev,
 230                                          struct sock *sk,
 231                                          can_err_mask_t err_mask)
 232 
 233 {
 234         if (err_mask)
 235                 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
 236                                   raw_rcv, sk);
 237 }
 238 
 239 static inline void raw_disable_allfilters(struct net *net,
 240                                           struct net_device *dev,
 241                                           struct sock *sk)
 242 {
 243         struct raw_sock *ro = raw_sk(sk);
 244 
 245         raw_disable_filters(net, dev, sk, ro->filter, ro->count);
 246         raw_disable_errfilter(net, dev, sk, ro->err_mask);
 247 }
 248 
 249 static int raw_enable_allfilters(struct net *net, struct net_device *dev,
 250                                  struct sock *sk)
 251 {
 252         struct raw_sock *ro = raw_sk(sk);
 253         int err;
 254 
 255         err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
 256         if (!err) {
 257                 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
 258                 if (err)
 259                         raw_disable_filters(net, dev, sk, ro->filter,
 260                                             ro->count);
 261         }
 262 
 263         return err;
 264 }
 265 
 266 static int raw_notifier(struct notifier_block *nb,
 267                         unsigned long msg, void *ptr)
 268 {
 269         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 270         struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
 271         struct sock *sk = &ro->sk;
 272 
 273         if (!net_eq(dev_net(dev), sock_net(sk)))
 274                 return NOTIFY_DONE;
 275 
 276         if (dev->type != ARPHRD_CAN)
 277                 return NOTIFY_DONE;
 278 
 279         if (ro->ifindex != dev->ifindex)
 280                 return NOTIFY_DONE;
 281 
 282         switch (msg) {
 283         case NETDEV_UNREGISTER:
 284                 lock_sock(sk);
 285                 /* remove current filters & unregister */
 286                 if (ro->bound)
 287                         raw_disable_allfilters(dev_net(dev), dev, sk);
 288 
 289                 if (ro->count > 1)
 290                         kfree(ro->filter);
 291 
 292                 ro->ifindex = 0;
 293                 ro->bound   = 0;
 294                 ro->count   = 0;
 295                 release_sock(sk);
 296 
 297                 sk->sk_err = ENODEV;
 298                 if (!sock_flag(sk, SOCK_DEAD))
 299                         sk->sk_error_report(sk);
 300                 break;
 301 
 302         case NETDEV_DOWN:
 303                 sk->sk_err = ENETDOWN;
 304                 if (!sock_flag(sk, SOCK_DEAD))
 305                         sk->sk_error_report(sk);
 306                 break;
 307         }
 308 
 309         return NOTIFY_DONE;
 310 }
 311 
 312 static int raw_init(struct sock *sk)
 313 {
 314         struct raw_sock *ro = raw_sk(sk);
 315 
 316         ro->bound            = 0;
 317         ro->ifindex          = 0;
 318 
 319         /* set default filter to single entry dfilter */
 320         ro->dfilter.can_id   = 0;
 321         ro->dfilter.can_mask = MASK_ALL;
 322         ro->filter           = &ro->dfilter;
 323         ro->count            = 1;
 324 
 325         /* set default loopback behaviour */
 326         ro->loopback         = 1;
 327         ro->recv_own_msgs    = 0;
 328         ro->fd_frames        = 0;
 329         ro->join_filters     = 0;
 330 
 331         /* alloc_percpu provides zero'ed memory */
 332         ro->uniq = alloc_percpu(struct uniqframe);
 333         if (unlikely(!ro->uniq))
 334                 return -ENOMEM;
 335 
 336         /* set notifier */
 337         ro->notifier.notifier_call = raw_notifier;
 338 
 339         register_netdevice_notifier(&ro->notifier);
 340 
 341         return 0;
 342 }
 343 
 344 static int raw_release(struct socket *sock)
 345 {
 346         struct sock *sk = sock->sk;
 347         struct raw_sock *ro;
 348 
 349         if (!sk)
 350                 return 0;
 351 
 352         ro = raw_sk(sk);
 353 
 354         unregister_netdevice_notifier(&ro->notifier);
 355 
 356         lock_sock(sk);
 357 
 358         /* remove current filters & unregister */
 359         if (ro->bound) {
 360                 if (ro->ifindex) {
 361                         struct net_device *dev;
 362 
 363                         dev = dev_get_by_index(sock_net(sk), ro->ifindex);
 364                         if (dev) {
 365                                 raw_disable_allfilters(dev_net(dev), dev, sk);
 366                                 dev_put(dev);
 367                         }
 368                 } else {
 369                         raw_disable_allfilters(sock_net(sk), NULL, sk);
 370                 }
 371         }
 372 
 373         if (ro->count > 1)
 374                 kfree(ro->filter);
 375 
 376         ro->ifindex = 0;
 377         ro->bound   = 0;
 378         ro->count   = 0;
 379         free_percpu(ro->uniq);
 380 
 381         sock_orphan(sk);
 382         sock->sk = NULL;
 383 
 384         release_sock(sk);
 385         sock_put(sk);
 386 
 387         return 0;
 388 }
 389 
 390 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 391 {
 392         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 393         struct sock *sk = sock->sk;
 394         struct raw_sock *ro = raw_sk(sk);
 395         int ifindex;
 396         int err = 0;
 397         int notify_enetdown = 0;
 398 
 399         if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex))
 400                 return -EINVAL;
 401         if (addr->can_family != AF_CAN)
 402                 return -EINVAL;
 403 
 404         lock_sock(sk);
 405 
 406         if (ro->bound && addr->can_ifindex == ro->ifindex)
 407                 goto out;
 408 
 409         if (addr->can_ifindex) {
 410                 struct net_device *dev;
 411 
 412                 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
 413                 if (!dev) {
 414                         err = -ENODEV;
 415                         goto out;
 416                 }
 417                 if (dev->type != ARPHRD_CAN) {
 418                         dev_put(dev);
 419                         err = -ENODEV;
 420                         goto out;
 421                 }
 422                 if (!(dev->flags & IFF_UP))
 423                         notify_enetdown = 1;
 424 
 425                 ifindex = dev->ifindex;
 426 
 427                 /* filters set by default/setsockopt */
 428                 err = raw_enable_allfilters(sock_net(sk), dev, sk);
 429                 dev_put(dev);
 430         } else {
 431                 ifindex = 0;
 432 
 433                 /* filters set by default/setsockopt */
 434                 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
 435         }
 436 
 437         if (!err) {
 438                 if (ro->bound) {
 439                         /* unregister old filters */
 440                         if (ro->ifindex) {
 441                                 struct net_device *dev;
 442 
 443                                 dev = dev_get_by_index(sock_net(sk),
 444                                                        ro->ifindex);
 445                                 if (dev) {
 446                                         raw_disable_allfilters(dev_net(dev),
 447                                                                dev, sk);
 448                                         dev_put(dev);
 449                                 }
 450                         } else {
 451                                 raw_disable_allfilters(sock_net(sk), NULL, sk);
 452                         }
 453                 }
 454                 ro->ifindex = ifindex;
 455                 ro->bound = 1;
 456         }
 457 
 458  out:
 459         release_sock(sk);
 460 
 461         if (notify_enetdown) {
 462                 sk->sk_err = ENETDOWN;
 463                 if (!sock_flag(sk, SOCK_DEAD))
 464                         sk->sk_error_report(sk);
 465         }
 466 
 467         return err;
 468 }
 469 
 470 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
 471                        int peer)
 472 {
 473         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 474         struct sock *sk = sock->sk;
 475         struct raw_sock *ro = raw_sk(sk);
 476 
 477         if (peer)
 478                 return -EOPNOTSUPP;
 479 
 480         memset(addr, 0, sizeof(*addr));
 481         addr->can_family  = AF_CAN;
 482         addr->can_ifindex = ro->ifindex;
 483 
 484         return sizeof(*addr);
 485 }
 486 
 487 static int raw_setsockopt(struct socket *sock, int level, int optname,
 488                           char __user *optval, unsigned int optlen)
 489 {
 490         struct sock *sk = sock->sk;
 491         struct raw_sock *ro = raw_sk(sk);
 492         struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
 493         struct can_filter sfilter;         /* single filter */
 494         struct net_device *dev = NULL;
 495         can_err_mask_t err_mask = 0;
 496         int count = 0;
 497         int err = 0;
 498 
 499         if (level != SOL_CAN_RAW)
 500                 return -EINVAL;
 501 
 502         switch (optname) {
 503         case CAN_RAW_FILTER:
 504                 if (optlen % sizeof(struct can_filter) != 0)
 505                         return -EINVAL;
 506 
 507                 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
 508                         return -EINVAL;
 509 
 510                 count = optlen / sizeof(struct can_filter);
 511 
 512                 if (count > 1) {
 513                         /* filter does not fit into dfilter => alloc space */
 514                         filter = memdup_user(optval, optlen);
 515                         if (IS_ERR(filter))
 516                                 return PTR_ERR(filter);
 517                 } else if (count == 1) {
 518                         if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
 519                                 return -EFAULT;
 520                 }
 521 
 522                 lock_sock(sk);
 523 
 524                 if (ro->bound && ro->ifindex)
 525                         dev = dev_get_by_index(sock_net(sk), ro->ifindex);
 526 
 527                 if (ro->bound) {
 528                         /* (try to) register the new filters */
 529                         if (count == 1)
 530                                 err = raw_enable_filters(sock_net(sk), dev, sk,
 531                                                          &sfilter, 1);
 532                         else
 533                                 err = raw_enable_filters(sock_net(sk), dev, sk,
 534                                                          filter, count);
 535                         if (err) {
 536                                 if (count > 1)
 537                                         kfree(filter);
 538                                 goto out_fil;
 539                         }
 540 
 541                         /* remove old filter registrations */
 542                         raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
 543                                             ro->count);
 544                 }
 545 
 546                 /* remove old filter space */
 547                 if (ro->count > 1)
 548                         kfree(ro->filter);
 549 
 550                 /* link new filters to the socket */
 551                 if (count == 1) {
 552                         /* copy filter data for single filter */
 553                         ro->dfilter = sfilter;
 554                         filter = &ro->dfilter;
 555                 }
 556                 ro->filter = filter;
 557                 ro->count  = count;
 558 
 559  out_fil:
 560                 if (dev)
 561                         dev_put(dev);
 562 
 563                 release_sock(sk);
 564 
 565                 break;
 566 
 567         case CAN_RAW_ERR_FILTER:
 568                 if (optlen != sizeof(err_mask))
 569                         return -EINVAL;
 570 
 571                 if (copy_from_user(&err_mask, optval, optlen))
 572                         return -EFAULT;
 573 
 574                 err_mask &= CAN_ERR_MASK;
 575 
 576                 lock_sock(sk);
 577 
 578                 if (ro->bound && ro->ifindex)
 579                         dev = dev_get_by_index(sock_net(sk), ro->ifindex);
 580 
 581                 /* remove current error mask */
 582                 if (ro->bound) {
 583                         /* (try to) register the new err_mask */
 584                         err = raw_enable_errfilter(sock_net(sk), dev, sk,
 585                                                    err_mask);
 586 
 587                         if (err)
 588                                 goto out_err;
 589 
 590                         /* remove old err_mask registration */
 591                         raw_disable_errfilter(sock_net(sk), dev, sk,
 592                                               ro->err_mask);
 593                 }
 594 
 595                 /* link new err_mask to the socket */
 596                 ro->err_mask = err_mask;
 597 
 598  out_err:
 599                 if (dev)
 600                         dev_put(dev);
 601 
 602                 release_sock(sk);
 603 
 604                 break;
 605 
 606         case CAN_RAW_LOOPBACK:
 607                 if (optlen != sizeof(ro->loopback))
 608                         return -EINVAL;
 609 
 610                 if (copy_from_user(&ro->loopback, optval, optlen))
 611                         return -EFAULT;
 612 
 613                 break;
 614 
 615         case CAN_RAW_RECV_OWN_MSGS:
 616                 if (optlen != sizeof(ro->recv_own_msgs))
 617                         return -EINVAL;
 618 
 619                 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
 620                         return -EFAULT;
 621 
 622                 break;
 623 
 624         case CAN_RAW_FD_FRAMES:
 625                 if (optlen != sizeof(ro->fd_frames))
 626                         return -EINVAL;
 627 
 628                 if (copy_from_user(&ro->fd_frames, optval, optlen))
 629                         return -EFAULT;
 630 
 631                 break;
 632 
 633         case CAN_RAW_JOIN_FILTERS:
 634                 if (optlen != sizeof(ro->join_filters))
 635                         return -EINVAL;
 636 
 637                 if (copy_from_user(&ro->join_filters, optval, optlen))
 638                         return -EFAULT;
 639 
 640                 break;
 641 
 642         default:
 643                 return -ENOPROTOOPT;
 644         }
 645         return err;
 646 }
 647 
 648 static int raw_getsockopt(struct socket *sock, int level, int optname,
 649                           char __user *optval, int __user *optlen)
 650 {
 651         struct sock *sk = sock->sk;
 652         struct raw_sock *ro = raw_sk(sk);
 653         int len;
 654         void *val;
 655         int err = 0;
 656 
 657         if (level != SOL_CAN_RAW)
 658                 return -EINVAL;
 659         if (get_user(len, optlen))
 660                 return -EFAULT;
 661         if (len < 0)
 662                 return -EINVAL;
 663 
 664         switch (optname) {
 665         case CAN_RAW_FILTER:
 666                 lock_sock(sk);
 667                 if (ro->count > 0) {
 668                         int fsize = ro->count * sizeof(struct can_filter);
 669 
 670                         if (len > fsize)
 671                                 len = fsize;
 672                         if (copy_to_user(optval, ro->filter, len))
 673                                 err = -EFAULT;
 674                 } else {
 675                         len = 0;
 676                 }
 677                 release_sock(sk);
 678 
 679                 if (!err)
 680                         err = put_user(len, optlen);
 681                 return err;
 682 
 683         case CAN_RAW_ERR_FILTER:
 684                 if (len > sizeof(can_err_mask_t))
 685                         len = sizeof(can_err_mask_t);
 686                 val = &ro->err_mask;
 687                 break;
 688 
 689         case CAN_RAW_LOOPBACK:
 690                 if (len > sizeof(int))
 691                         len = sizeof(int);
 692                 val = &ro->loopback;
 693                 break;
 694 
 695         case CAN_RAW_RECV_OWN_MSGS:
 696                 if (len > sizeof(int))
 697                         len = sizeof(int);
 698                 val = &ro->recv_own_msgs;
 699                 break;
 700 
 701         case CAN_RAW_FD_FRAMES:
 702                 if (len > sizeof(int))
 703                         len = sizeof(int);
 704                 val = &ro->fd_frames;
 705                 break;
 706 
 707         case CAN_RAW_JOIN_FILTERS:
 708                 if (len > sizeof(int))
 709                         len = sizeof(int);
 710                 val = &ro->join_filters;
 711                 break;
 712 
 713         default:
 714                 return -ENOPROTOOPT;
 715         }
 716 
 717         if (put_user(len, optlen))
 718                 return -EFAULT;
 719         if (copy_to_user(optval, val, len))
 720                 return -EFAULT;
 721         return 0;
 722 }
 723 
 724 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 725 {
 726         struct sock *sk = sock->sk;
 727         struct raw_sock *ro = raw_sk(sk);
 728         struct sk_buff *skb;
 729         struct net_device *dev;
 730         int ifindex;
 731         int err;
 732 
 733         if (msg->msg_name) {
 734                 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
 735 
 736                 if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex))
 737                         return -EINVAL;
 738 
 739                 if (addr->can_family != AF_CAN)
 740                         return -EINVAL;
 741 
 742                 ifindex = addr->can_ifindex;
 743         } else {
 744                 ifindex = ro->ifindex;
 745         }
 746 
 747         dev = dev_get_by_index(sock_net(sk), ifindex);
 748         if (!dev)
 749                 return -ENXIO;
 750 
 751         err = -EINVAL;
 752         if (ro->fd_frames && dev->mtu == CANFD_MTU) {
 753                 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
 754                         goto put_dev;
 755         } else {
 756                 if (unlikely(size != CAN_MTU))
 757                         goto put_dev;
 758         }
 759 
 760         skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
 761                                   msg->msg_flags & MSG_DONTWAIT, &err);
 762         if (!skb)
 763                 goto put_dev;
 764 
 765         can_skb_reserve(skb);
 766         can_skb_prv(skb)->ifindex = dev->ifindex;
 767         can_skb_prv(skb)->skbcnt = 0;
 768 
 769         err = memcpy_from_msg(skb_put(skb, size), msg, size);
 770         if (err < 0)
 771                 goto free_skb;
 772 
 773         skb_setup_tx_timestamp(skb, sk->sk_tsflags);
 774 
 775         skb->dev = dev;
 776         skb->sk  = sk;
 777         skb->priority = sk->sk_priority;
 778 
 779         err = can_send(skb, ro->loopback);
 780 
 781         dev_put(dev);
 782 
 783         if (err)
 784                 goto send_failed;
 785 
 786         return size;
 787 
 788 free_skb:
 789         kfree_skb(skb);
 790 put_dev:
 791         dev_put(dev);
 792 send_failed:
 793         return err;
 794 }
 795 
 796 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 797                        int flags)
 798 {
 799         struct sock *sk = sock->sk;
 800         struct sk_buff *skb;
 801         int err = 0;
 802         int noblock;
 803 
 804         noblock =  flags & MSG_DONTWAIT;
 805         flags   &= ~MSG_DONTWAIT;
 806 
 807         skb = skb_recv_datagram(sk, flags, noblock, &err);
 808         if (!skb)
 809                 return err;
 810 
 811         if (size < skb->len)
 812                 msg->msg_flags |= MSG_TRUNC;
 813         else
 814                 size = skb->len;
 815 
 816         err = memcpy_to_msg(msg, skb->data, size);
 817         if (err < 0) {
 818                 skb_free_datagram(sk, skb);
 819                 return err;
 820         }
 821 
 822         sock_recv_ts_and_drops(msg, sk, skb);
 823 
 824         if (msg->msg_name) {
 825                 __sockaddr_check_size(sizeof(struct sockaddr_can));
 826                 msg->msg_namelen = sizeof(struct sockaddr_can);
 827                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 828         }
 829 
 830         /* assign the flags that have been recorded in raw_rcv() */
 831         msg->msg_flags |= *(raw_flags(skb));
 832 
 833         skb_free_datagram(sk, skb);
 834 
 835         return size;
 836 }
 837 
 838 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
 839                                 unsigned long arg)
 840 {
 841         /* no ioctls for socket layer -> hand it down to NIC layer */
 842         return -ENOIOCTLCMD;
 843 }
 844 
 845 static const struct proto_ops raw_ops = {
 846         .family        = PF_CAN,
 847         .release       = raw_release,
 848         .bind          = raw_bind,
 849         .connect       = sock_no_connect,
 850         .socketpair    = sock_no_socketpair,
 851         .accept        = sock_no_accept,
 852         .getname       = raw_getname,
 853         .poll          = datagram_poll,
 854         .ioctl         = raw_sock_no_ioctlcmd,
 855         .gettstamp     = sock_gettstamp,
 856         .listen        = sock_no_listen,
 857         .shutdown      = sock_no_shutdown,
 858         .setsockopt    = raw_setsockopt,
 859         .getsockopt    = raw_getsockopt,
 860         .sendmsg       = raw_sendmsg,
 861         .recvmsg       = raw_recvmsg,
 862         .mmap          = sock_no_mmap,
 863         .sendpage      = sock_no_sendpage,
 864 };
 865 
 866 static struct proto raw_proto __read_mostly = {
 867         .name       = "CAN_RAW",
 868         .owner      = THIS_MODULE,
 869         .obj_size   = sizeof(struct raw_sock),
 870         .init       = raw_init,
 871 };
 872 
 873 static const struct can_proto raw_can_proto = {
 874         .type       = SOCK_RAW,
 875         .protocol   = CAN_RAW,
 876         .ops        = &raw_ops,
 877         .prot       = &raw_proto,
 878 };
 879 
 880 static __init int raw_module_init(void)
 881 {
 882         int err;
 883 
 884         pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n");
 885 
 886         err = can_proto_register(&raw_can_proto);
 887         if (err < 0)
 888                 pr_err("can: registration of raw protocol failed\n");
 889 
 890         return err;
 891 }
 892 
 893 static __exit void raw_module_exit(void)
 894 {
 895         can_proto_unregister(&raw_can_proto);
 896 }
 897 
 898 module_init(raw_module_init);
 899 module_exit(raw_module_exit);