1 // SPDX-License-Identifier: (GPL-2.0 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 MODULE_DESCRIPTION("PF_CAN raw protocol"); 59 MODULE_LICENSE("Dual BSD/GPL"); 60 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>"); 61 MODULE_ALIAS("can-proto-1"); 62 63 #define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) 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 list_head 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 static LIST_HEAD(raw_notifier_list); 99 static DEFINE_SPINLOCK(raw_notifier_lock); 100 static struct raw_sock *raw_busy_notifier; 101 102 /* Return pointer to store the extra msg flags for raw_recvmsg(). 103 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 104 * in skb->cb. 105 */ 106 static inline unsigned int *raw_flags(struct sk_buff *skb) 107 { 108 sock_skb_cb_check_size(sizeof(struct sockaddr_can) + 109 sizeof(unsigned int)); 110 111 /* return pointer after struct sockaddr_can */ 112 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 113 } 114 115 static inline struct raw_sock *raw_sk(const struct sock *sk) 116 { 117 return (struct raw_sock *)sk; 118 } 119 120 static void raw_rcv(struct sk_buff *oskb, void *data) 121 { 122 struct sock *sk = (struct sock *)data; 123 struct raw_sock *ro = raw_sk(sk); 124 struct sockaddr_can *addr; 125 struct sk_buff *skb; 126 unsigned int *pflags; 127 128 /* check the received tx sock reference */ 129 if (!ro->recv_own_msgs && oskb->sk == sk) 130 return; 131 132 /* do not pass non-CAN2.0 frames to a legacy socket */ 133 if (!ro->fd_frames && oskb->len != CAN_MTU) 134 return; 135 136 /* eliminate multiple filter matches for the same skb */ 137 if (this_cpu_ptr(ro->uniq)->skb == oskb && 138 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { 139 if (ro->join_filters) { 140 this_cpu_inc(ro->uniq->join_rx_count); 141 /* drop frame until all enabled filters matched */ 142 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) 143 return; 144 } else { 145 return; 146 } 147 } else { 148 this_cpu_ptr(ro->uniq)->skb = oskb; 149 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; 150 this_cpu_ptr(ro->uniq)->join_rx_count = 1; 151 /* drop first frame to check all enabled filters? */ 152 if (ro->join_filters && ro->count > 1) 153 return; 154 } 155 156 /* clone the given skb to be able to enqueue it into the rcv queue */ 157 skb = skb_clone(oskb, GFP_ATOMIC); 158 if (!skb) 159 return; 160 161 /* Put the datagram to the queue so that raw_recvmsg() can get 162 * it from there. We need to pass the interface index to 163 * raw_recvmsg(). We pass a whole struct sockaddr_can in 164 * skb->cb containing the interface index. 165 */ 166 167 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 168 addr = (struct sockaddr_can *)skb->cb; 169 memset(addr, 0, sizeof(*addr)); 170 addr->can_family = AF_CAN; 171 addr->can_ifindex = skb->dev->ifindex; 172 173 /* add CAN specific message flags for raw_recvmsg() */ 174 pflags = raw_flags(skb); 175 *pflags = 0; 176 if (oskb->sk) 177 *pflags |= MSG_DONTROUTE; 178 if (oskb->sk == sk) 179 *pflags |= MSG_CONFIRM; 180 181 if (sock_queue_rcv_skb(sk, skb) < 0) 182 kfree_skb(skb); 183 } 184 185 static int raw_enable_filters(struct net *net, struct net_device *dev, 186 struct sock *sk, struct can_filter *filter, 187 int count) 188 { 189 int err = 0; 190 int i; 191 192 for (i = 0; i < count; i++) { 193 err = can_rx_register(net, dev, filter[i].can_id, 194 filter[i].can_mask, 195 raw_rcv, sk, "raw", sk); 196 if (err) { 197 /* clean up successfully registered filters */ 198 while (--i >= 0) 199 can_rx_unregister(net, dev, filter[i].can_id, 200 filter[i].can_mask, 201 raw_rcv, sk); 202 break; 203 } 204 } 205 206 return err; 207 } 208 209 static int raw_enable_errfilter(struct net *net, struct net_device *dev, 210 struct sock *sk, can_err_mask_t err_mask) 211 { 212 int err = 0; 213 214 if (err_mask) 215 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG, 216 raw_rcv, sk, "raw", sk); 217 218 return err; 219 } 220 221 static void raw_disable_filters(struct net *net, struct net_device *dev, 222 struct sock *sk, struct can_filter *filter, 223 int count) 224 { 225 int i; 226 227 for (i = 0; i < count; i++) 228 can_rx_unregister(net, dev, filter[i].can_id, 229 filter[i].can_mask, raw_rcv, sk); 230 } 231 232 static inline void raw_disable_errfilter(struct net *net, 233 struct net_device *dev, 234 struct sock *sk, 235 can_err_mask_t err_mask) 236 237 { 238 if (err_mask) 239 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG, 240 raw_rcv, sk); 241 } 242 243 static inline void raw_disable_allfilters(struct net *net, 244 struct net_device *dev, 245 struct sock *sk) 246 { 247 struct raw_sock *ro = raw_sk(sk); 248 249 raw_disable_filters(net, dev, sk, ro->filter, ro->count); 250 raw_disable_errfilter(net, dev, sk, ro->err_mask); 251 } 252 253 static int raw_enable_allfilters(struct net *net, struct net_device *dev, 254 struct sock *sk) 255 { 256 struct raw_sock *ro = raw_sk(sk); 257 int err; 258 259 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count); 260 if (!err) { 261 err = raw_enable_errfilter(net, dev, sk, ro->err_mask); 262 if (err) 263 raw_disable_filters(net, dev, sk, ro->filter, 264 ro->count); 265 } 266 267 return err; 268 } 269 270 static void raw_notify(struct raw_sock *ro, unsigned long msg, 271 struct net_device *dev) 272 { 273 struct sock *sk = &ro->sk; 274 275 if (!net_eq(dev_net(dev), sock_net(sk))) 276 return; 277 278 if (ro->ifindex != dev->ifindex) 279 return; 280 281 switch (msg) { 282 case NETDEV_UNREGISTER: 283 lock_sock(sk); 284 /* remove current filters & unregister */ 285 if (ro->bound) 286 raw_disable_allfilters(dev_net(dev), dev, sk); 287 288 if (ro->count > 1) 289 kfree(ro->filter); 290 291 ro->ifindex = 0; 292 ro->bound = 0; 293 ro->count = 0; 294 release_sock(sk); 295 296 sk->sk_err = ENODEV; 297 if (!sock_flag(sk, SOCK_DEAD)) 298 sk_error_report(sk); 299 break; 300 301 case NETDEV_DOWN: 302 sk->sk_err = ENETDOWN; 303 if (!sock_flag(sk, SOCK_DEAD)) 304 sk_error_report(sk); 305 break; 306 } 307 } 308 309 static int raw_notifier(struct notifier_block *nb, unsigned long msg, 310 void *ptr) 311 { 312 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 313 314 if (dev->type != ARPHRD_CAN) 315 return NOTIFY_DONE; 316 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 317 return NOTIFY_DONE; 318 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */ 319 return NOTIFY_DONE; 320 321 spin_lock(&raw_notifier_lock); 322 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) { 323 spin_unlock(&raw_notifier_lock); 324 raw_notify(raw_busy_notifier, msg, dev); 325 spin_lock(&raw_notifier_lock); 326 } 327 raw_busy_notifier = NULL; 328 spin_unlock(&raw_notifier_lock); 329 return NOTIFY_DONE; 330 } 331 332 static int raw_init(struct sock *sk) 333 { 334 struct raw_sock *ro = raw_sk(sk); 335 336 ro->bound = 0; 337 ro->ifindex = 0; 338 339 /* set default filter to single entry dfilter */ 340 ro->dfilter.can_id = 0; 341 ro->dfilter.can_mask = MASK_ALL; 342 ro->filter = &ro->dfilter; 343 ro->count = 1; 344 345 /* set default loopback behaviour */ 346 ro->loopback = 1; 347 ro->recv_own_msgs = 0; 348 ro->fd_frames = 0; 349 ro->join_filters = 0; 350 351 /* alloc_percpu provides zero'ed memory */ 352 ro->uniq = alloc_percpu(struct uniqframe); 353 if (unlikely(!ro->uniq)) 354 return -ENOMEM; 355 356 /* set notifier */ 357 spin_lock(&raw_notifier_lock); 358 list_add_tail(&ro->notifier, &raw_notifier_list); 359 spin_unlock(&raw_notifier_lock); 360 361 return 0; 362 } 363 364 static int raw_release(struct socket *sock) 365 { 366 struct sock *sk = sock->sk; 367 struct raw_sock *ro; 368 369 if (!sk) 370 return 0; 371 372 ro = raw_sk(sk); 373 374 spin_lock(&raw_notifier_lock); 375 while (raw_busy_notifier == ro) { 376 spin_unlock(&raw_notifier_lock); 377 schedule_timeout_uninterruptible(1); 378 spin_lock(&raw_notifier_lock); 379 } 380 list_del(&ro->notifier); 381 spin_unlock(&raw_notifier_lock); 382 383 lock_sock(sk); 384 385 /* remove current filters & unregister */ 386 if (ro->bound) { 387 if (ro->ifindex) { 388 struct net_device *dev; 389 390 dev = dev_get_by_index(sock_net(sk), ro->ifindex); 391 if (dev) { 392 raw_disable_allfilters(dev_net(dev), dev, sk); 393 dev_put(dev); 394 } 395 } else { 396 raw_disable_allfilters(sock_net(sk), NULL, sk); 397 } 398 } 399 400 if (ro->count > 1) 401 kfree(ro->filter); 402 403 ro->ifindex = 0; 404 ro->bound = 0; 405 ro->count = 0; 406 free_percpu(ro->uniq); 407 408 sock_orphan(sk); 409 sock->sk = NULL; 410 411 release_sock(sk); 412 sock_put(sk); 413 414 return 0; 415 } 416 417 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 418 { 419 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 420 struct sock *sk = sock->sk; 421 struct raw_sock *ro = raw_sk(sk); 422 int ifindex; 423 int err = 0; 424 int notify_enetdown = 0; 425 426 if (len < RAW_MIN_NAMELEN) 427 return -EINVAL; 428 if (addr->can_family != AF_CAN) 429 return -EINVAL; 430 431 lock_sock(sk); 432 433 if (ro->bound && addr->can_ifindex == ro->ifindex) 434 goto out; 435 436 if (addr->can_ifindex) { 437 struct net_device *dev; 438 439 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); 440 if (!dev) { 441 err = -ENODEV; 442 goto out; 443 } 444 if (dev->type != ARPHRD_CAN) { 445 dev_put(dev); 446 err = -ENODEV; 447 goto out; 448 } 449 if (!(dev->flags & IFF_UP)) 450 notify_enetdown = 1; 451 452 ifindex = dev->ifindex; 453 454 /* filters set by default/setsockopt */ 455 err = raw_enable_allfilters(sock_net(sk), dev, sk); 456 dev_put(dev); 457 } else { 458 ifindex = 0; 459 460 /* filters set by default/setsockopt */ 461 err = raw_enable_allfilters(sock_net(sk), NULL, sk); 462 } 463 464 if (!err) { 465 if (ro->bound) { 466 /* unregister old filters */ 467 if (ro->ifindex) { 468 struct net_device *dev; 469 470 dev = dev_get_by_index(sock_net(sk), 471 ro->ifindex); 472 if (dev) { 473 raw_disable_allfilters(dev_net(dev), 474 dev, sk); 475 dev_put(dev); 476 } 477 } else { 478 raw_disable_allfilters(sock_net(sk), NULL, sk); 479 } 480 } 481 ro->ifindex = ifindex; 482 ro->bound = 1; 483 } 484 485 out: 486 release_sock(sk); 487 488 if (notify_enetdown) { 489 sk->sk_err = ENETDOWN; 490 if (!sock_flag(sk, SOCK_DEAD)) 491 sk_error_report(sk); 492 } 493 494 return err; 495 } 496 497 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 498 int peer) 499 { 500 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 501 struct sock *sk = sock->sk; 502 struct raw_sock *ro = raw_sk(sk); 503 504 if (peer) 505 return -EOPNOTSUPP; 506 507 memset(addr, 0, RAW_MIN_NAMELEN); 508 addr->can_family = AF_CAN; 509 addr->can_ifindex = ro->ifindex; 510 511 return RAW_MIN_NAMELEN; 512 } 513 514 static int raw_setsockopt(struct socket *sock, int level, int optname, 515 sockptr_t optval, unsigned int optlen) 516 { 517 struct sock *sk = sock->sk; 518 struct raw_sock *ro = raw_sk(sk); 519 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 520 struct can_filter sfilter; /* single filter */ 521 struct net_device *dev = NULL; 522 can_err_mask_t err_mask = 0; 523 int count = 0; 524 int err = 0; 525 526 if (level != SOL_CAN_RAW) 527 return -EINVAL; 528 529 switch (optname) { 530 case CAN_RAW_FILTER: 531 if (optlen % sizeof(struct can_filter) != 0) 532 return -EINVAL; 533 534 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) 535 return -EINVAL; 536 537 count = optlen / sizeof(struct can_filter); 538 539 if (count > 1) { 540 /* filter does not fit into dfilter => alloc space */ 541 filter = memdup_sockptr(optval, optlen); 542 if (IS_ERR(filter)) 543 return PTR_ERR(filter); 544 } else if (count == 1) { 545 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter))) 546 return -EFAULT; 547 } 548 549 lock_sock(sk); 550 551 if (ro->bound && ro->ifindex) 552 dev = dev_get_by_index(sock_net(sk), ro->ifindex); 553 554 if (ro->bound) { 555 /* (try to) register the new filters */ 556 if (count == 1) 557 err = raw_enable_filters(sock_net(sk), dev, sk, 558 &sfilter, 1); 559 else 560 err = raw_enable_filters(sock_net(sk), dev, sk, 561 filter, count); 562 if (err) { 563 if (count > 1) 564 kfree(filter); 565 goto out_fil; 566 } 567 568 /* remove old filter registrations */ 569 raw_disable_filters(sock_net(sk), dev, sk, ro->filter, 570 ro->count); 571 } 572 573 /* remove old filter space */ 574 if (ro->count > 1) 575 kfree(ro->filter); 576 577 /* link new filters to the socket */ 578 if (count == 1) { 579 /* copy filter data for single filter */ 580 ro->dfilter = sfilter; 581 filter = &ro->dfilter; 582 } 583 ro->filter = filter; 584 ro->count = count; 585 586 out_fil: 587 if (dev) 588 dev_put(dev); 589 590 release_sock(sk); 591 592 break; 593 594 case CAN_RAW_ERR_FILTER: 595 if (optlen != sizeof(err_mask)) 596 return -EINVAL; 597 598 if (copy_from_sockptr(&err_mask, optval, optlen)) 599 return -EFAULT; 600 601 err_mask &= CAN_ERR_MASK; 602 603 lock_sock(sk); 604 605 if (ro->bound && ro->ifindex) 606 dev = dev_get_by_index(sock_net(sk), ro->ifindex); 607 608 /* remove current error mask */ 609 if (ro->bound) { 610 /* (try to) register the new err_mask */ 611 err = raw_enable_errfilter(sock_net(sk), dev, sk, 612 err_mask); 613 614 if (err) 615 goto out_err; 616 617 /* remove old err_mask registration */ 618 raw_disable_errfilter(sock_net(sk), dev, sk, 619 ro->err_mask); 620 } 621 622 /* link new err_mask to the socket */ 623 ro->err_mask = err_mask; 624 625 out_err: 626 if (dev) 627 dev_put(dev); 628 629 release_sock(sk); 630 631 break; 632 633 case CAN_RAW_LOOPBACK: 634 if (optlen != sizeof(ro->loopback)) 635 return -EINVAL; 636 637 if (copy_from_sockptr(&ro->loopback, optval, optlen)) 638 return -EFAULT; 639 640 break; 641 642 case CAN_RAW_RECV_OWN_MSGS: 643 if (optlen != sizeof(ro->recv_own_msgs)) 644 return -EINVAL; 645 646 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen)) 647 return -EFAULT; 648 649 break; 650 651 case CAN_RAW_FD_FRAMES: 652 if (optlen != sizeof(ro->fd_frames)) 653 return -EINVAL; 654 655 if (copy_from_sockptr(&ro->fd_frames, optval, optlen)) 656 return -EFAULT; 657 658 break; 659 660 case CAN_RAW_JOIN_FILTERS: 661 if (optlen != sizeof(ro->join_filters)) 662 return -EINVAL; 663 664 if (copy_from_sockptr(&ro->join_filters, optval, optlen)) 665 return -EFAULT; 666 667 break; 668 669 default: 670 return -ENOPROTOOPT; 671 } 672 return err; 673 } 674 675 static int raw_getsockopt(struct socket *sock, int level, int optname, 676 char __user *optval, int __user *optlen) 677 { 678 struct sock *sk = sock->sk; 679 struct raw_sock *ro = raw_sk(sk); 680 int len; 681 void *val; 682 int err = 0; 683 684 if (level != SOL_CAN_RAW) 685 return -EINVAL; 686 if (get_user(len, optlen)) 687 return -EFAULT; 688 if (len < 0) 689 return -EINVAL; 690 691 switch (optname) { 692 case CAN_RAW_FILTER: 693 lock_sock(sk); 694 if (ro->count > 0) { 695 int fsize = ro->count * sizeof(struct can_filter); 696 697 /* user space buffer to small for filter list? */ 698 if (len < fsize) { 699 /* return -ERANGE and needed space in optlen */ 700 err = -ERANGE; 701 if (put_user(fsize, optlen)) 702 err = -EFAULT; 703 } else { 704 if (len > fsize) 705 len = fsize; 706 if (copy_to_user(optval, ro->filter, len)) 707 err = -EFAULT; 708 } 709 } else { 710 len = 0; 711 } 712 release_sock(sk); 713 714 if (!err) 715 err = put_user(len, optlen); 716 return err; 717 718 case CAN_RAW_ERR_FILTER: 719 if (len > sizeof(can_err_mask_t)) 720 len = sizeof(can_err_mask_t); 721 val = &ro->err_mask; 722 break; 723 724 case CAN_RAW_LOOPBACK: 725 if (len > sizeof(int)) 726 len = sizeof(int); 727 val = &ro->loopback; 728 break; 729 730 case CAN_RAW_RECV_OWN_MSGS: 731 if (len > sizeof(int)) 732 len = sizeof(int); 733 val = &ro->recv_own_msgs; 734 break; 735 736 case CAN_RAW_FD_FRAMES: 737 if (len > sizeof(int)) 738 len = sizeof(int); 739 val = &ro->fd_frames; 740 break; 741 742 case CAN_RAW_JOIN_FILTERS: 743 if (len > sizeof(int)) 744 len = sizeof(int); 745 val = &ro->join_filters; 746 break; 747 748 default: 749 return -ENOPROTOOPT; 750 } 751 752 if (put_user(len, optlen)) 753 return -EFAULT; 754 if (copy_to_user(optval, val, len)) 755 return -EFAULT; 756 return 0; 757 } 758 759 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 760 { 761 struct sock *sk = sock->sk; 762 struct raw_sock *ro = raw_sk(sk); 763 struct sk_buff *skb; 764 struct net_device *dev; 765 int ifindex; 766 int err; 767 768 if (msg->msg_name) { 769 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 770 771 if (msg->msg_namelen < RAW_MIN_NAMELEN) 772 return -EINVAL; 773 774 if (addr->can_family != AF_CAN) 775 return -EINVAL; 776 777 ifindex = addr->can_ifindex; 778 } else { 779 ifindex = ro->ifindex; 780 } 781 782 dev = dev_get_by_index(sock_net(sk), ifindex); 783 if (!dev) 784 return -ENXIO; 785 786 err = -EINVAL; 787 if (ro->fd_frames && dev->mtu == CANFD_MTU) { 788 if (unlikely(size != CANFD_MTU && size != CAN_MTU)) 789 goto put_dev; 790 } else { 791 if (unlikely(size != CAN_MTU)) 792 goto put_dev; 793 } 794 795 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), 796 msg->msg_flags & MSG_DONTWAIT, &err); 797 if (!skb) 798 goto put_dev; 799 800 can_skb_reserve(skb); 801 can_skb_prv(skb)->ifindex = dev->ifindex; 802 can_skb_prv(skb)->skbcnt = 0; 803 804 err = memcpy_from_msg(skb_put(skb, size), msg, size); 805 if (err < 0) 806 goto free_skb; 807 808 skb_setup_tx_timestamp(skb, sk->sk_tsflags); 809 810 skb->dev = dev; 811 skb->sk = sk; 812 skb->priority = sk->sk_priority; 813 814 err = can_send(skb, ro->loopback); 815 816 dev_put(dev); 817 818 if (err) 819 goto send_failed; 820 821 return size; 822 823 free_skb: 824 kfree_skb(skb); 825 put_dev: 826 dev_put(dev); 827 send_failed: 828 return err; 829 } 830 831 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 832 int flags) 833 { 834 struct sock *sk = sock->sk; 835 struct sk_buff *skb; 836 int err = 0; 837 int noblock; 838 839 noblock = flags & MSG_DONTWAIT; 840 flags &= ~MSG_DONTWAIT; 841 842 if (flags & MSG_ERRQUEUE) 843 return sock_recv_errqueue(sk, msg, size, 844 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE); 845 846 skb = skb_recv_datagram(sk, flags, noblock, &err); 847 if (!skb) 848 return err; 849 850 if (size < skb->len) 851 msg->msg_flags |= MSG_TRUNC; 852 else 853 size = skb->len; 854 855 err = memcpy_to_msg(msg, skb->data, size); 856 if (err < 0) { 857 skb_free_datagram(sk, skb); 858 return err; 859 } 860 861 sock_recv_ts_and_drops(msg, sk, skb); 862 863 if (msg->msg_name) { 864 __sockaddr_check_size(RAW_MIN_NAMELEN); 865 msg->msg_namelen = RAW_MIN_NAMELEN; 866 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 867 } 868 869 /* assign the flags that have been recorded in raw_rcv() */ 870 msg->msg_flags |= *(raw_flags(skb)); 871 872 skb_free_datagram(sk, skb); 873 874 return size; 875 } 876 877 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 878 unsigned long arg) 879 { 880 /* no ioctls for socket layer -> hand it down to NIC layer */ 881 return -ENOIOCTLCMD; 882 } 883 884 static const struct proto_ops raw_ops = { 885 .family = PF_CAN, 886 .release = raw_release, 887 .bind = raw_bind, 888 .connect = sock_no_connect, 889 .socketpair = sock_no_socketpair, 890 .accept = sock_no_accept, 891 .getname = raw_getname, 892 .poll = datagram_poll, 893 .ioctl = raw_sock_no_ioctlcmd, 894 .gettstamp = sock_gettstamp, 895 .listen = sock_no_listen, 896 .shutdown = sock_no_shutdown, 897 .setsockopt = raw_setsockopt, 898 .getsockopt = raw_getsockopt, 899 .sendmsg = raw_sendmsg, 900 .recvmsg = raw_recvmsg, 901 .mmap = sock_no_mmap, 902 .sendpage = sock_no_sendpage, 903 }; 904 905 static struct proto raw_proto __read_mostly = { 906 .name = "CAN_RAW", 907 .owner = THIS_MODULE, 908 .obj_size = sizeof(struct raw_sock), 909 .init = raw_init, 910 }; 911 912 static const struct can_proto raw_can_proto = { 913 .type = SOCK_RAW, 914 .protocol = CAN_RAW, 915 .ops = &raw_ops, 916 .prot = &raw_proto, 917 }; 918 919 static struct notifier_block canraw_notifier = { 920 .notifier_call = raw_notifier 921 }; 922 923 static __init int raw_module_init(void) 924 { 925 int err; 926 927 pr_info("can: raw protocol\n"); 928 929 err = can_proto_register(&raw_can_proto); 930 if (err < 0) 931 pr_err("can: registration of raw protocol failed\n"); 932 else 933 register_netdevice_notifier(&canraw_notifier); 934 935 return err; 936 } 937 938 static __exit void raw_module_exit(void) 939 { 940 can_proto_unregister(&raw_can_proto); 941 unregister_netdevice_notifier(&canraw_notifier); 942 } 943 944 module_init(raw_module_init); 945 module_exit(raw_module_exit); 946