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/dev.h> /* for can_is_canxl_dev_mtu() */ 54 #include <linux/can/skb.h> 55 #include <linux/can/raw.h> 56 #include <net/sock.h> 57 #include <net/net_namespace.h> 58 59 MODULE_DESCRIPTION("PF_CAN raw protocol"); 60 MODULE_LICENSE("Dual BSD/GPL"); 61 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>"); 62 MODULE_ALIAS("can-proto-1"); 63 64 #define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) 65 66 #define MASK_ALL 0 67 68 /* A raw socket has a list of can_filters attached to it, each receiving 69 * the CAN frames matching that filter. If the filter list is empty, 70 * no CAN frames will be received by the socket. The default after 71 * opening the socket, is to have one filter which receives all frames. 72 * The filter list is allocated dynamically with the exception of the 73 * list containing only one item. This common case is optimized by 74 * storing the single filter in dfilter, to avoid using dynamic memory. 75 */ 76 77 struct uniqframe { 78 int skbcnt; 79 const struct sk_buff *skb; 80 unsigned int join_rx_count; 81 }; 82 83 struct raw_sock { 84 struct sock sk; 85 int bound; 86 int ifindex; 87 struct list_head notifier; 88 int loopback; 89 int recv_own_msgs; 90 int fd_frames; 91 int xl_frames; 92 int join_filters; 93 int count; /* number of active filters */ 94 struct can_filter dfilter; /* default/single filter */ 95 struct can_filter *filter; /* pointer to filter(s) */ 96 can_err_mask_t err_mask; 97 struct uniqframe __percpu *uniq; 98 }; 99 100 static LIST_HEAD(raw_notifier_list); 101 static DEFINE_SPINLOCK(raw_notifier_lock); 102 static struct raw_sock *raw_busy_notifier; 103 104 /* Return pointer to store the extra msg flags for raw_recvmsg(). 105 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 106 * in skb->cb. 107 */ 108 static inline unsigned int *raw_flags(struct sk_buff *skb) 109 { 110 sock_skb_cb_check_size(sizeof(struct sockaddr_can) + 111 sizeof(unsigned int)); 112 113 /* return pointer after struct sockaddr_can */ 114 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 115 } 116 117 static inline struct raw_sock *raw_sk(const struct sock *sk) 118 { 119 return (struct raw_sock *)sk; 120 } 121 122 static void raw_rcv(struct sk_buff *oskb, void *data) 123 { 124 struct sock *sk = (struct sock *)data; 125 struct raw_sock *ro = raw_sk(sk); 126 struct sockaddr_can *addr; 127 struct sk_buff *skb; 128 unsigned int *pflags; 129 130 /* check the received tx sock reference */ 131 if (!ro->recv_own_msgs && oskb->sk == sk) 132 return; 133 134 /* make sure to not pass oversized frames to the socket */ 135 if ((can_is_canfd_skb(oskb) && !ro->fd_frames && !ro->xl_frames) || 136 (can_is_canxl_skb(oskb) && !ro->xl_frames)) 137 return; 138 139 /* eliminate multiple filter matches for the same skb */ 140 if (this_cpu_ptr(ro->uniq)->skb == oskb && 141 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { 142 if (!ro->join_filters) 143 return; 144 145 this_cpu_inc(ro->uniq->join_rx_count); 146 /* drop frame until all enabled filters matched */ 147 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) 148 return; 149 } else { 150 this_cpu_ptr(ro->uniq)->skb = oskb; 151 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; 152 this_cpu_ptr(ro->uniq)->join_rx_count = 1; 153 /* drop first frame to check all enabled filters? */ 154 if (ro->join_filters && ro->count > 1) 155 return; 156 } 157 158 /* clone the given skb to be able to enqueue it into the rcv queue */ 159 skb = skb_clone(oskb, GFP_ATOMIC); 160 if (!skb) 161 return; 162 163 /* Put the datagram to the queue so that raw_recvmsg() can get 164 * it from there. We need to pass the interface index to 165 * raw_recvmsg(). We pass a whole struct sockaddr_can in 166 * skb->cb containing the interface index. 167 */ 168 169 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 170 addr = (struct sockaddr_can *)skb->cb; 171 memset(addr, 0, sizeof(*addr)); 172 addr->can_family = AF_CAN; 173 addr->can_ifindex = skb->dev->ifindex; 174 175 /* add CAN specific message flags for raw_recvmsg() */ 176 pflags = raw_flags(skb); 177 *pflags = 0; 178 if (oskb->sk) 179 *pflags |= MSG_DONTROUTE; 180 if (oskb->sk == sk) 181 *pflags |= MSG_CONFIRM; 182 183 if (sock_queue_rcv_skb(sk, skb) < 0) 184 kfree_skb(skb); 185 } 186 187 static int raw_enable_filters(struct net *net, struct net_device *dev, 188 struct sock *sk, struct can_filter *filter, 189 int count) 190 { 191 int err = 0; 192 int i; 193 194 for (i = 0; i < count; i++) { 195 err = can_rx_register(net, dev, filter[i].can_id, 196 filter[i].can_mask, 197 raw_rcv, sk, "raw", sk); 198 if (err) { 199 /* clean up successfully registered filters */ 200 while (--i >= 0) 201 can_rx_unregister(net, dev, filter[i].can_id, 202 filter[i].can_mask, 203 raw_rcv, sk); 204 break; 205 } 206 } 207 208 return err; 209 } 210 211 static int raw_enable_errfilter(struct net *net, struct net_device *dev, 212 struct sock *sk, can_err_mask_t err_mask) 213 { 214 int err = 0; 215 216 if (err_mask) 217 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG, 218 raw_rcv, sk, "raw", sk); 219 220 return err; 221 } 222 223 static void raw_disable_filters(struct net *net, struct net_device *dev, 224 struct sock *sk, struct can_filter *filter, 225 int count) 226 { 227 int i; 228 229 for (i = 0; i < count; i++) 230 can_rx_unregister(net, dev, filter[i].can_id, 231 filter[i].can_mask, raw_rcv, sk); 232 } 233 234 static inline void raw_disable_errfilter(struct net *net, 235 struct net_device *dev, 236 struct sock *sk, 237 can_err_mask_t err_mask) 238 239 { 240 if (err_mask) 241 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG, 242 raw_rcv, sk); 243 } 244 245 static inline void raw_disable_allfilters(struct net *net, 246 struct net_device *dev, 247 struct sock *sk) 248 { 249 struct raw_sock *ro = raw_sk(sk); 250 251 raw_disable_filters(net, dev, sk, ro->filter, ro->count); 252 raw_disable_errfilter(net, dev, sk, ro->err_mask); 253 } 254 255 static int raw_enable_allfilters(struct net *net, struct net_device *dev, 256 struct sock *sk) 257 { 258 struct raw_sock *ro = raw_sk(sk); 259 int err; 260 261 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count); 262 if (!err) { 263 err = raw_enable_errfilter(net, dev, sk, ro->err_mask); 264 if (err) 265 raw_disable_filters(net, dev, sk, ro->filter, 266 ro->count); 267 } 268 269 return err; 270 } 271 272 static void raw_notify(struct raw_sock *ro, unsigned long msg, 273 struct net_device *dev) 274 { 275 struct sock *sk = &ro->sk; 276 277 if (!net_eq(dev_net(dev), sock_net(sk))) 278 return; 279 280 if (ro->ifindex != dev->ifindex) 281 return; 282 283 switch (msg) { 284 case NETDEV_UNREGISTER: 285 lock_sock(sk); 286 /* remove current filters & unregister */ 287 if (ro->bound) 288 raw_disable_allfilters(dev_net(dev), dev, sk); 289 290 if (ro->count > 1) 291 kfree(ro->filter); 292 293 ro->ifindex = 0; 294 ro->bound = 0; 295 ro->count = 0; 296 release_sock(sk); 297 298 sk->sk_err = ENODEV; 299 if (!sock_flag(sk, SOCK_DEAD)) 300 sk_error_report(sk); 301 break; 302 303 case NETDEV_DOWN: 304 sk->sk_err = ENETDOWN; 305 if (!sock_flag(sk, SOCK_DEAD)) 306 sk_error_report(sk); 307 break; 308 } 309 } 310 311 static int raw_notifier(struct notifier_block *nb, unsigned long msg, 312 void *ptr) 313 { 314 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 315 316 if (dev->type != ARPHRD_CAN) 317 return NOTIFY_DONE; 318 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 319 return NOTIFY_DONE; 320 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */ 321 return NOTIFY_DONE; 322 323 spin_lock(&raw_notifier_lock); 324 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) { 325 spin_unlock(&raw_notifier_lock); 326 raw_notify(raw_busy_notifier, msg, dev); 327 spin_lock(&raw_notifier_lock); 328 } 329 raw_busy_notifier = NULL; 330 spin_unlock(&raw_notifier_lock); 331 return NOTIFY_DONE; 332 } 333 334 static int raw_init(struct sock *sk) 335 { 336 struct raw_sock *ro = raw_sk(sk); 337 338 ro->bound = 0; 339 ro->ifindex = 0; 340 341 /* set default filter to single entry dfilter */ 342 ro->dfilter.can_id = 0; 343 ro->dfilter.can_mask = MASK_ALL; 344 ro->filter = &ro->dfilter; 345 ro->count = 1; 346 347 /* set default loopback behaviour */ 348 ro->loopback = 1; 349 ro->recv_own_msgs = 0; 350 ro->fd_frames = 0; 351 ro->xl_frames = 0; 352 ro->join_filters = 0; 353 354 /* alloc_percpu provides zero'ed memory */ 355 ro->uniq = alloc_percpu(struct uniqframe); 356 if (unlikely(!ro->uniq)) 357 return -ENOMEM; 358 359 /* set notifier */ 360 spin_lock(&raw_notifier_lock); 361 list_add_tail(&ro->notifier, &raw_notifier_list); 362 spin_unlock(&raw_notifier_lock); 363 364 return 0; 365 } 366 367 static int raw_release(struct socket *sock) 368 { 369 struct sock *sk = sock->sk; 370 struct raw_sock *ro; 371 372 if (!sk) 373 return 0; 374 375 ro = raw_sk(sk); 376 377 spin_lock(&raw_notifier_lock); 378 while (raw_busy_notifier == ro) { 379 spin_unlock(&raw_notifier_lock); 380 schedule_timeout_uninterruptible(1); 381 spin_lock(&raw_notifier_lock); 382 } 383 list_del(&ro->notifier); 384 spin_unlock(&raw_notifier_lock); 385 386 lock_sock(sk); 387 388 /* remove current filters & unregister */ 389 if (ro->bound) { 390 if (ro->ifindex) { 391 struct net_device *dev; 392 393 dev = dev_get_by_index(sock_net(sk), ro->ifindex); 394 if (dev) { 395 raw_disable_allfilters(dev_net(dev), dev, sk); 396 dev_put(dev); 397 } 398 } else { 399 raw_disable_allfilters(sock_net(sk), NULL, sk); 400 } 401 } 402 403 if (ro->count > 1) 404 kfree(ro->filter); 405 406 ro->ifindex = 0; 407 ro->bound = 0; 408 ro->count = 0; 409 free_percpu(ro->uniq); 410 411 sock_orphan(sk); 412 sock->sk = NULL; 413 414 release_sock(sk); 415 sock_put(sk); 416 417 return 0; 418 } 419 420 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 421 { 422 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 423 struct sock *sk = sock->sk; 424 struct raw_sock *ro = raw_sk(sk); 425 int ifindex; 426 int err = 0; 427 int notify_enetdown = 0; 428 429 if (len < RAW_MIN_NAMELEN) 430 return -EINVAL; 431 if (addr->can_family != AF_CAN) 432 return -EINVAL; 433 434 lock_sock(sk); 435 436 if (ro->bound && addr->can_ifindex == ro->ifindex) 437 goto out; 438 439 if (addr->can_ifindex) { 440 struct net_device *dev; 441 442 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); 443 if (!dev) { 444 err = -ENODEV; 445 goto out; 446 } 447 if (dev->type != ARPHRD_CAN) { 448 dev_put(dev); 449 err = -ENODEV; 450 goto out; 451 } 452 if (!(dev->flags & IFF_UP)) 453 notify_enetdown = 1; 454 455 ifindex = dev->ifindex; 456 457 /* filters set by default/setsockopt */ 458 err = raw_enable_allfilters(sock_net(sk), dev, sk); 459 dev_put(dev); 460 } else { 461 ifindex = 0; 462 463 /* filters set by default/setsockopt */ 464 err = raw_enable_allfilters(sock_net(sk), NULL, sk); 465 } 466 467 if (!err) { 468 if (ro->bound) { 469 /* unregister old filters */ 470 if (ro->ifindex) { 471 struct net_device *dev; 472 473 dev = dev_get_by_index(sock_net(sk), 474 ro->ifindex); 475 if (dev) { 476 raw_disable_allfilters(dev_net(dev), 477 dev, sk); 478 dev_put(dev); 479 } 480 } else { 481 raw_disable_allfilters(sock_net(sk), NULL, sk); 482 } 483 } 484 ro->ifindex = ifindex; 485 ro->bound = 1; 486 } 487 488 out: 489 release_sock(sk); 490 491 if (notify_enetdown) { 492 sk->sk_err = ENETDOWN; 493 if (!sock_flag(sk, SOCK_DEAD)) 494 sk_error_report(sk); 495 } 496 497 return err; 498 } 499 500 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 501 int peer) 502 { 503 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 504 struct sock *sk = sock->sk; 505 struct raw_sock *ro = raw_sk(sk); 506 507 if (peer) 508 return -EOPNOTSUPP; 509 510 memset(addr, 0, RAW_MIN_NAMELEN); 511 addr->can_family = AF_CAN; 512 addr->can_ifindex = ro->ifindex; 513 514 return RAW_MIN_NAMELEN; 515 } 516 517 static int raw_setsockopt(struct socket *sock, int level, int optname, 518 sockptr_t optval, unsigned int optlen) 519 { 520 struct sock *sk = sock->sk; 521 struct raw_sock *ro = raw_sk(sk); 522 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 523 struct can_filter sfilter; /* single filter */ 524 struct net_device *dev = NULL; 525 can_err_mask_t err_mask = 0; 526 int count = 0; 527 int err = 0; 528 529 if (level != SOL_CAN_RAW) 530 return -EINVAL; 531 532 switch (optname) { 533 case CAN_RAW_FILTER: 534 if (optlen % sizeof(struct can_filter) != 0) 535 return -EINVAL; 536 537 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) 538 return -EINVAL; 539 540 count = optlen / sizeof(struct can_filter); 541 542 if (count > 1) { 543 /* filter does not fit into dfilter => alloc space */ 544 filter = memdup_sockptr(optval, optlen); 545 if (IS_ERR(filter)) 546 return PTR_ERR(filter); 547 } else if (count == 1) { 548 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter))) 549 return -EFAULT; 550 } 551 552 rtnl_lock(); 553 lock_sock(sk); 554 555 if (ro->bound && ro->ifindex) { 556 dev = dev_get_by_index(sock_net(sk), ro->ifindex); 557 if (!dev) { 558 if (count > 1) 559 kfree(filter); 560 err = -ENODEV; 561 goto out_fil; 562 } 563 } 564 565 if (ro->bound) { 566 /* (try to) register the new filters */ 567 if (count == 1) 568 err = raw_enable_filters(sock_net(sk), dev, sk, 569 &sfilter, 1); 570 else 571 err = raw_enable_filters(sock_net(sk), dev, sk, 572 filter, count); 573 if (err) { 574 if (count > 1) 575 kfree(filter); 576 goto out_fil; 577 } 578 579 /* remove old filter registrations */ 580 raw_disable_filters(sock_net(sk), dev, sk, ro->filter, 581 ro->count); 582 } 583 584 /* remove old filter space */ 585 if (ro->count > 1) 586 kfree(ro->filter); 587 588 /* link new filters to the socket */ 589 if (count == 1) { 590 /* copy filter data for single filter */ 591 ro->dfilter = sfilter; 592 filter = &ro->dfilter; 593 } 594 ro->filter = filter; 595 ro->count = count; 596 597 out_fil: 598 dev_put(dev); 599 release_sock(sk); 600 rtnl_unlock(); 601 602 break; 603 604 case CAN_RAW_ERR_FILTER: 605 if (optlen != sizeof(err_mask)) 606 return -EINVAL; 607 608 if (copy_from_sockptr(&err_mask, optval, optlen)) 609 return -EFAULT; 610 611 err_mask &= CAN_ERR_MASK; 612 613 rtnl_lock(); 614 lock_sock(sk); 615 616 if (ro->bound && ro->ifindex) { 617 dev = dev_get_by_index(sock_net(sk), ro->ifindex); 618 if (!dev) { 619 err = -ENODEV; 620 goto out_err; 621 } 622 } 623 624 /* remove current error mask */ 625 if (ro->bound) { 626 /* (try to) register the new err_mask */ 627 err = raw_enable_errfilter(sock_net(sk), dev, sk, 628 err_mask); 629 630 if (err) 631 goto out_err; 632 633 /* remove old err_mask registration */ 634 raw_disable_errfilter(sock_net(sk), dev, sk, 635 ro->err_mask); 636 } 637 638 /* link new err_mask to the socket */ 639 ro->err_mask = err_mask; 640 641 out_err: 642 dev_put(dev); 643 release_sock(sk); 644 rtnl_unlock(); 645 646 break; 647 648 case CAN_RAW_LOOPBACK: 649 if (optlen != sizeof(ro->loopback)) 650 return -EINVAL; 651 652 if (copy_from_sockptr(&ro->loopback, optval, optlen)) 653 return -EFAULT; 654 655 break; 656 657 case CAN_RAW_RECV_OWN_MSGS: 658 if (optlen != sizeof(ro->recv_own_msgs)) 659 return -EINVAL; 660 661 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen)) 662 return -EFAULT; 663 664 break; 665 666 case CAN_RAW_FD_FRAMES: 667 if (optlen != sizeof(ro->fd_frames)) 668 return -EINVAL; 669 670 if (copy_from_sockptr(&ro->fd_frames, optval, optlen)) 671 return -EFAULT; 672 673 break; 674 675 case CAN_RAW_XL_FRAMES: 676 if (optlen != sizeof(ro->xl_frames)) 677 return -EINVAL; 678 679 if (copy_from_sockptr(&ro->xl_frames, optval, optlen)) 680 return -EFAULT; 681 682 break; 683 684 case CAN_RAW_JOIN_FILTERS: 685 if (optlen != sizeof(ro->join_filters)) 686 return -EINVAL; 687 688 if (copy_from_sockptr(&ro->join_filters, optval, optlen)) 689 return -EFAULT; 690 691 break; 692 693 default: 694 return -ENOPROTOOPT; 695 } 696 return err; 697 } 698 699 static int raw_getsockopt(struct socket *sock, int level, int optname, 700 char __user *optval, int __user *optlen) 701 { 702 struct sock *sk = sock->sk; 703 struct raw_sock *ro = raw_sk(sk); 704 int len; 705 void *val; 706 int err = 0; 707 708 if (level != SOL_CAN_RAW) 709 return -EINVAL; 710 if (get_user(len, optlen)) 711 return -EFAULT; 712 if (len < 0) 713 return -EINVAL; 714 715 switch (optname) { 716 case CAN_RAW_FILTER: 717 lock_sock(sk); 718 if (ro->count > 0) { 719 int fsize = ro->count * sizeof(struct can_filter); 720 721 /* user space buffer to small for filter list? */ 722 if (len < fsize) { 723 /* return -ERANGE and needed space in optlen */ 724 err = -ERANGE; 725 if (put_user(fsize, optlen)) 726 err = -EFAULT; 727 } else { 728 if (len > fsize) 729 len = fsize; 730 if (copy_to_user(optval, ro->filter, len)) 731 err = -EFAULT; 732 } 733 } else { 734 len = 0; 735 } 736 release_sock(sk); 737 738 if (!err) 739 err = put_user(len, optlen); 740 return err; 741 742 case CAN_RAW_ERR_FILTER: 743 if (len > sizeof(can_err_mask_t)) 744 len = sizeof(can_err_mask_t); 745 val = &ro->err_mask; 746 break; 747 748 case CAN_RAW_LOOPBACK: 749 if (len > sizeof(int)) 750 len = sizeof(int); 751 val = &ro->loopback; 752 break; 753 754 case CAN_RAW_RECV_OWN_MSGS: 755 if (len > sizeof(int)) 756 len = sizeof(int); 757 val = &ro->recv_own_msgs; 758 break; 759 760 case CAN_RAW_FD_FRAMES: 761 if (len > sizeof(int)) 762 len = sizeof(int); 763 val = &ro->fd_frames; 764 break; 765 766 case CAN_RAW_XL_FRAMES: 767 if (len > sizeof(int)) 768 len = sizeof(int); 769 val = &ro->xl_frames; 770 break; 771 772 case CAN_RAW_JOIN_FILTERS: 773 if (len > sizeof(int)) 774 len = sizeof(int); 775 val = &ro->join_filters; 776 break; 777 778 default: 779 return -ENOPROTOOPT; 780 } 781 782 if (put_user(len, optlen)) 783 return -EFAULT; 784 if (copy_to_user(optval, val, len)) 785 return -EFAULT; 786 return 0; 787 } 788 789 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 790 { 791 struct sock *sk = sock->sk; 792 struct raw_sock *ro = raw_sk(sk); 793 struct sockcm_cookie sockc; 794 struct sk_buff *skb; 795 struct net_device *dev; 796 int ifindex; 797 int err = -EINVAL; 798 799 /* check for valid CAN frame sizes */ 800 if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU) 801 return -EINVAL; 802 803 if (msg->msg_name) { 804 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 805 806 if (msg->msg_namelen < RAW_MIN_NAMELEN) 807 return -EINVAL; 808 809 if (addr->can_family != AF_CAN) 810 return -EINVAL; 811 812 ifindex = addr->can_ifindex; 813 } else { 814 ifindex = ro->ifindex; 815 } 816 817 dev = dev_get_by_index(sock_net(sk), ifindex); 818 if (!dev) 819 return -ENXIO; 820 821 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), 822 msg->msg_flags & MSG_DONTWAIT, &err); 823 if (!skb) 824 goto put_dev; 825 826 can_skb_reserve(skb); 827 can_skb_prv(skb)->ifindex = dev->ifindex; 828 can_skb_prv(skb)->skbcnt = 0; 829 830 /* fill the skb before testing for valid CAN frames */ 831 err = memcpy_from_msg(skb_put(skb, size), msg, size); 832 if (err < 0) 833 goto free_skb; 834 835 err = -EINVAL; 836 if (ro->xl_frames && can_is_canxl_dev_mtu(dev->mtu)) { 837 /* CAN XL, CAN FD and Classical CAN */ 838 if (!can_is_canxl_skb(skb) && !can_is_canfd_skb(skb) && 839 !can_is_can_skb(skb)) 840 goto free_skb; 841 } else if (ro->fd_frames && dev->mtu == CANFD_MTU) { 842 /* CAN FD and Classical CAN */ 843 if (!can_is_canfd_skb(skb) && !can_is_can_skb(skb)) 844 goto free_skb; 845 } else { 846 /* Classical CAN */ 847 if (!can_is_can_skb(skb)) 848 goto free_skb; 849 } 850 851 sockcm_init(&sockc, sk); 852 if (msg->msg_controllen) { 853 err = sock_cmsg_send(sk, msg, &sockc); 854 if (unlikely(err)) 855 goto free_skb; 856 } 857 858 skb->dev = dev; 859 skb->priority = sk->sk_priority; 860 skb->mark = sk->sk_mark; 861 skb->tstamp = sockc.transmit_time; 862 863 skb_setup_tx_timestamp(skb, sockc.tsflags); 864 865 err = can_send(skb, ro->loopback); 866 867 dev_put(dev); 868 869 if (err) 870 goto send_failed; 871 872 return size; 873 874 free_skb: 875 kfree_skb(skb); 876 put_dev: 877 dev_put(dev); 878 send_failed: 879 return err; 880 } 881 882 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 883 int flags) 884 { 885 struct sock *sk = sock->sk; 886 struct sk_buff *skb; 887 int err = 0; 888 889 if (flags & MSG_ERRQUEUE) 890 return sock_recv_errqueue(sk, msg, size, 891 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE); 892 893 skb = skb_recv_datagram(sk, flags, &err); 894 if (!skb) 895 return err; 896 897 if (size < skb->len) 898 msg->msg_flags |= MSG_TRUNC; 899 else 900 size = skb->len; 901 902 err = memcpy_to_msg(msg, skb->data, size); 903 if (err < 0) { 904 skb_free_datagram(sk, skb); 905 return err; 906 } 907 908 sock_recv_cmsgs(msg, sk, skb); 909 910 if (msg->msg_name) { 911 __sockaddr_check_size(RAW_MIN_NAMELEN); 912 msg->msg_namelen = RAW_MIN_NAMELEN; 913 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 914 } 915 916 /* assign the flags that have been recorded in raw_rcv() */ 917 msg->msg_flags |= *(raw_flags(skb)); 918 919 skb_free_datagram(sk, skb); 920 921 return size; 922 } 923 924 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 925 unsigned long arg) 926 { 927 /* no ioctls for socket layer -> hand it down to NIC layer */ 928 return -ENOIOCTLCMD; 929 } 930 931 static const struct proto_ops raw_ops = { 932 .family = PF_CAN, 933 .release = raw_release, 934 .bind = raw_bind, 935 .connect = sock_no_connect, 936 .socketpair = sock_no_socketpair, 937 .accept = sock_no_accept, 938 .getname = raw_getname, 939 .poll = datagram_poll, 940 .ioctl = raw_sock_no_ioctlcmd, 941 .gettstamp = sock_gettstamp, 942 .listen = sock_no_listen, 943 .shutdown = sock_no_shutdown, 944 .setsockopt = raw_setsockopt, 945 .getsockopt = raw_getsockopt, 946 .sendmsg = raw_sendmsg, 947 .recvmsg = raw_recvmsg, 948 .mmap = sock_no_mmap, 949 .sendpage = sock_no_sendpage, 950 }; 951 952 static struct proto raw_proto __read_mostly = { 953 .name = "CAN_RAW", 954 .owner = THIS_MODULE, 955 .obj_size = sizeof(struct raw_sock), 956 .init = raw_init, 957 }; 958 959 static const struct can_proto raw_can_proto = { 960 .type = SOCK_RAW, 961 .protocol = CAN_RAW, 962 .ops = &raw_ops, 963 .prot = &raw_proto, 964 }; 965 966 static struct notifier_block canraw_notifier = { 967 .notifier_call = raw_notifier 968 }; 969 970 static __init int raw_module_init(void) 971 { 972 int err; 973 974 pr_info("can: raw protocol\n"); 975 976 err = register_netdevice_notifier(&canraw_notifier); 977 if (err) 978 return err; 979 980 err = can_proto_register(&raw_can_proto); 981 if (err < 0) { 982 pr_err("can: registration of raw protocol failed\n"); 983 goto register_proto_failed; 984 } 985 986 return 0; 987 988 register_proto_failed: 989 unregister_netdevice_notifier(&canraw_notifier); 990 return err; 991 } 992 993 static __exit void raw_module_exit(void) 994 { 995 can_proto_unregister(&raw_can_proto); 996 unregister_netdevice_notifier(&canraw_notifier); 997 } 998 999 module_init(raw_module_init); 1000 module_exit(raw_module_exit); 1001