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 net_device *dev; 88 netdevice_tracker dev_tracker; 89 struct list_head notifier; 90 int loopback; 91 int recv_own_msgs; 92 int fd_frames; 93 int xl_frames; 94 int join_filters; 95 int count; /* number of active filters */ 96 struct can_filter dfilter; /* default/single filter */ 97 struct can_filter *filter; /* pointer to filter(s) */ 98 can_err_mask_t err_mask; 99 struct uniqframe __percpu *uniq; 100 }; 101 102 static LIST_HEAD(raw_notifier_list); 103 static DEFINE_SPINLOCK(raw_notifier_lock); 104 static struct raw_sock *raw_busy_notifier; 105 106 /* Return pointer to store the extra msg flags for raw_recvmsg(). 107 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 108 * in skb->cb. 109 */ 110 static inline unsigned int *raw_flags(struct sk_buff *skb) 111 { 112 sock_skb_cb_check_size(sizeof(struct sockaddr_can) + 113 sizeof(unsigned int)); 114 115 /* return pointer after struct sockaddr_can */ 116 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 117 } 118 119 static inline struct raw_sock *raw_sk(const struct sock *sk) 120 { 121 return (struct raw_sock *)sk; 122 } 123 124 static void raw_rcv(struct sk_buff *oskb, void *data) 125 { 126 struct sock *sk = (struct sock *)data; 127 struct raw_sock *ro = raw_sk(sk); 128 struct sockaddr_can *addr; 129 struct sk_buff *skb; 130 unsigned int *pflags; 131 132 /* check the received tx sock reference */ 133 if (!ro->recv_own_msgs && oskb->sk == sk) 134 return; 135 136 /* make sure to not pass oversized frames to the socket */ 137 if ((!ro->fd_frames && can_is_canfd_skb(oskb)) || 138 (!ro->xl_frames && can_is_canxl_skb(oskb))) 139 return; 140 141 /* eliminate multiple filter matches for the same skb */ 142 if (this_cpu_ptr(ro->uniq)->skb == oskb && 143 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { 144 if (!ro->join_filters) 145 return; 146 147 this_cpu_inc(ro->uniq->join_rx_count); 148 /* drop frame until all enabled filters matched */ 149 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) 150 return; 151 } else { 152 this_cpu_ptr(ro->uniq)->skb = oskb; 153 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; 154 this_cpu_ptr(ro->uniq)->join_rx_count = 1; 155 /* drop first frame to check all enabled filters? */ 156 if (ro->join_filters && ro->count > 1) 157 return; 158 } 159 160 /* clone the given skb to be able to enqueue it into the rcv queue */ 161 skb = skb_clone(oskb, GFP_ATOMIC); 162 if (!skb) 163 return; 164 165 /* Put the datagram to the queue so that raw_recvmsg() can get 166 * it from there. We need to pass the interface index to 167 * raw_recvmsg(). We pass a whole struct sockaddr_can in 168 * skb->cb containing the interface index. 169 */ 170 171 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 172 addr = (struct sockaddr_can *)skb->cb; 173 memset(addr, 0, sizeof(*addr)); 174 addr->can_family = AF_CAN; 175 addr->can_ifindex = skb->dev->ifindex; 176 177 /* add CAN specific message flags for raw_recvmsg() */ 178 pflags = raw_flags(skb); 179 *pflags = 0; 180 if (oskb->sk) 181 *pflags |= MSG_DONTROUTE; 182 if (oskb->sk == sk) 183 *pflags |= MSG_CONFIRM; 184 185 if (sock_queue_rcv_skb(sk, skb) < 0) 186 kfree_skb(skb); 187 } 188 189 static int raw_enable_filters(struct net *net, struct net_device *dev, 190 struct sock *sk, struct can_filter *filter, 191 int count) 192 { 193 int err = 0; 194 int i; 195 196 for (i = 0; i < count; i++) { 197 err = can_rx_register(net, dev, filter[i].can_id, 198 filter[i].can_mask, 199 raw_rcv, sk, "raw", sk); 200 if (err) { 201 /* clean up successfully registered filters */ 202 while (--i >= 0) 203 can_rx_unregister(net, dev, filter[i].can_id, 204 filter[i].can_mask, 205 raw_rcv, sk); 206 break; 207 } 208 } 209 210 return err; 211 } 212 213 static int raw_enable_errfilter(struct net *net, struct net_device *dev, 214 struct sock *sk, can_err_mask_t err_mask) 215 { 216 int err = 0; 217 218 if (err_mask) 219 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG, 220 raw_rcv, sk, "raw", sk); 221 222 return err; 223 } 224 225 static void raw_disable_filters(struct net *net, struct net_device *dev, 226 struct sock *sk, struct can_filter *filter, 227 int count) 228 { 229 int i; 230 231 for (i = 0; i < count; i++) 232 can_rx_unregister(net, dev, filter[i].can_id, 233 filter[i].can_mask, raw_rcv, sk); 234 } 235 236 static inline void raw_disable_errfilter(struct net *net, 237 struct net_device *dev, 238 struct sock *sk, 239 can_err_mask_t err_mask) 240 241 { 242 if (err_mask) 243 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG, 244 raw_rcv, sk); 245 } 246 247 static inline void raw_disable_allfilters(struct net *net, 248 struct net_device *dev, 249 struct sock *sk) 250 { 251 struct raw_sock *ro = raw_sk(sk); 252 253 raw_disable_filters(net, dev, sk, ro->filter, ro->count); 254 raw_disable_errfilter(net, dev, sk, ro->err_mask); 255 } 256 257 static int raw_enable_allfilters(struct net *net, struct net_device *dev, 258 struct sock *sk) 259 { 260 struct raw_sock *ro = raw_sk(sk); 261 int err; 262 263 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count); 264 if (!err) { 265 err = raw_enable_errfilter(net, dev, sk, ro->err_mask); 266 if (err) 267 raw_disable_filters(net, dev, sk, ro->filter, 268 ro->count); 269 } 270 271 return err; 272 } 273 274 static void raw_notify(struct raw_sock *ro, unsigned long msg, 275 struct net_device *dev) 276 { 277 struct sock *sk = &ro->sk; 278 279 if (!net_eq(dev_net(dev), sock_net(sk))) 280 return; 281 282 if (ro->dev != dev) 283 return; 284 285 switch (msg) { 286 case NETDEV_UNREGISTER: 287 lock_sock(sk); 288 /* remove current filters & unregister */ 289 if (ro->bound) { 290 raw_disable_allfilters(dev_net(dev), dev, sk); 291 netdev_put(dev, &ro->dev_tracker); 292 } 293 294 if (ro->count > 1) 295 kfree(ro->filter); 296 297 ro->ifindex = 0; 298 ro->bound = 0; 299 ro->dev = NULL; 300 ro->count = 0; 301 release_sock(sk); 302 303 sk->sk_err = ENODEV; 304 if (!sock_flag(sk, SOCK_DEAD)) 305 sk_error_report(sk); 306 break; 307 308 case NETDEV_DOWN: 309 sk->sk_err = ENETDOWN; 310 if (!sock_flag(sk, SOCK_DEAD)) 311 sk_error_report(sk); 312 break; 313 } 314 } 315 316 static int raw_notifier(struct notifier_block *nb, unsigned long msg, 317 void *ptr) 318 { 319 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 320 321 if (dev->type != ARPHRD_CAN) 322 return NOTIFY_DONE; 323 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 324 return NOTIFY_DONE; 325 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */ 326 return NOTIFY_DONE; 327 328 spin_lock(&raw_notifier_lock); 329 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) { 330 spin_unlock(&raw_notifier_lock); 331 raw_notify(raw_busy_notifier, msg, dev); 332 spin_lock(&raw_notifier_lock); 333 } 334 raw_busy_notifier = NULL; 335 spin_unlock(&raw_notifier_lock); 336 return NOTIFY_DONE; 337 } 338 339 static int raw_init(struct sock *sk) 340 { 341 struct raw_sock *ro = raw_sk(sk); 342 343 ro->bound = 0; 344 ro->ifindex = 0; 345 ro->dev = NULL; 346 347 /* set default filter to single entry dfilter */ 348 ro->dfilter.can_id = 0; 349 ro->dfilter.can_mask = MASK_ALL; 350 ro->filter = &ro->dfilter; 351 ro->count = 1; 352 353 /* set default loopback behaviour */ 354 ro->loopback = 1; 355 ro->recv_own_msgs = 0; 356 ro->fd_frames = 0; 357 ro->xl_frames = 0; 358 ro->join_filters = 0; 359 360 /* alloc_percpu provides zero'ed memory */ 361 ro->uniq = alloc_percpu(struct uniqframe); 362 if (unlikely(!ro->uniq)) 363 return -ENOMEM; 364 365 /* set notifier */ 366 spin_lock(&raw_notifier_lock); 367 list_add_tail(&ro->notifier, &raw_notifier_list); 368 spin_unlock(&raw_notifier_lock); 369 370 return 0; 371 } 372 373 static int raw_release(struct socket *sock) 374 { 375 struct sock *sk = sock->sk; 376 struct raw_sock *ro; 377 378 if (!sk) 379 return 0; 380 381 ro = raw_sk(sk); 382 383 spin_lock(&raw_notifier_lock); 384 while (raw_busy_notifier == ro) { 385 spin_unlock(&raw_notifier_lock); 386 schedule_timeout_uninterruptible(1); 387 spin_lock(&raw_notifier_lock); 388 } 389 list_del(&ro->notifier); 390 spin_unlock(&raw_notifier_lock); 391 392 rtnl_lock(); 393 lock_sock(sk); 394 395 /* remove current filters & unregister */ 396 if (ro->bound) { 397 if (ro->dev) { 398 raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk); 399 netdev_put(ro->dev, &ro->dev_tracker); 400 } else { 401 raw_disable_allfilters(sock_net(sk), NULL, sk); 402 } 403 } 404 405 if (ro->count > 1) 406 kfree(ro->filter); 407 408 ro->ifindex = 0; 409 ro->bound = 0; 410 ro->dev = NULL; 411 ro->count = 0; 412 free_percpu(ro->uniq); 413 414 sock_orphan(sk); 415 sock->sk = NULL; 416 417 release_sock(sk); 418 rtnl_unlock(); 419 420 sock_put(sk); 421 422 return 0; 423 } 424 425 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) 426 { 427 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 428 struct sock *sk = sock->sk; 429 struct raw_sock *ro = raw_sk(sk); 430 struct net_device *dev = NULL; 431 int ifindex; 432 int err = 0; 433 int notify_enetdown = 0; 434 435 if (len < RAW_MIN_NAMELEN) 436 return -EINVAL; 437 if (addr->can_family != AF_CAN) 438 return -EINVAL; 439 440 rtnl_lock(); 441 lock_sock(sk); 442 443 if (ro->bound && addr->can_ifindex == ro->ifindex) 444 goto out; 445 446 if (addr->can_ifindex) { 447 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); 448 if (!dev) { 449 err = -ENODEV; 450 goto out; 451 } 452 if (dev->type != ARPHRD_CAN) { 453 err = -ENODEV; 454 goto out_put_dev; 455 } 456 457 if (!(dev->flags & IFF_UP)) 458 notify_enetdown = 1; 459 460 ifindex = dev->ifindex; 461 462 /* filters set by default/setsockopt */ 463 err = raw_enable_allfilters(sock_net(sk), dev, sk); 464 if (err) 465 goto out_put_dev; 466 467 } else { 468 ifindex = 0; 469 470 /* filters set by default/setsockopt */ 471 err = raw_enable_allfilters(sock_net(sk), NULL, sk); 472 } 473 474 if (!err) { 475 if (ro->bound) { 476 /* unregister old filters */ 477 if (ro->dev) { 478 raw_disable_allfilters(dev_net(ro->dev), 479 ro->dev, sk); 480 /* drop reference to old ro->dev */ 481 netdev_put(ro->dev, &ro->dev_tracker); 482 } else { 483 raw_disable_allfilters(sock_net(sk), NULL, sk); 484 } 485 } 486 ro->ifindex = ifindex; 487 ro->bound = 1; 488 /* bind() ok -> hold a reference for new ro->dev */ 489 ro->dev = dev; 490 if (ro->dev) 491 netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL); 492 } 493 494 out_put_dev: 495 /* remove potential reference from dev_get_by_index() */ 496 dev_put(dev); 497 out: 498 release_sock(sk); 499 rtnl_unlock(); 500 501 if (notify_enetdown) { 502 sk->sk_err = ENETDOWN; 503 if (!sock_flag(sk, SOCK_DEAD)) 504 sk_error_report(sk); 505 } 506 507 return err; 508 } 509 510 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 511 int peer) 512 { 513 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 514 struct sock *sk = sock->sk; 515 struct raw_sock *ro = raw_sk(sk); 516 517 if (peer) 518 return -EOPNOTSUPP; 519 520 memset(addr, 0, RAW_MIN_NAMELEN); 521 addr->can_family = AF_CAN; 522 addr->can_ifindex = ro->ifindex; 523 524 return RAW_MIN_NAMELEN; 525 } 526 527 static int raw_setsockopt(struct socket *sock, int level, int optname, 528 sockptr_t optval, unsigned int optlen) 529 { 530 struct sock *sk = sock->sk; 531 struct raw_sock *ro = raw_sk(sk); 532 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 533 struct can_filter sfilter; /* single filter */ 534 struct net_device *dev = NULL; 535 can_err_mask_t err_mask = 0; 536 int fd_frames; 537 int count = 0; 538 int err = 0; 539 540 if (level != SOL_CAN_RAW) 541 return -EINVAL; 542 543 switch (optname) { 544 case CAN_RAW_FILTER: 545 if (optlen % sizeof(struct can_filter) != 0) 546 return -EINVAL; 547 548 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) 549 return -EINVAL; 550 551 count = optlen / sizeof(struct can_filter); 552 553 if (count > 1) { 554 /* filter does not fit into dfilter => alloc space */ 555 filter = memdup_sockptr(optval, optlen); 556 if (IS_ERR(filter)) 557 return PTR_ERR(filter); 558 } else if (count == 1) { 559 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter))) 560 return -EFAULT; 561 } 562 563 rtnl_lock(); 564 lock_sock(sk); 565 566 dev = ro->dev; 567 if (ro->bound && dev) { 568 if (dev->reg_state != NETREG_REGISTERED) { 569 if (count > 1) 570 kfree(filter); 571 err = -ENODEV; 572 goto out_fil; 573 } 574 } 575 576 if (ro->bound) { 577 /* (try to) register the new filters */ 578 if (count == 1) 579 err = raw_enable_filters(sock_net(sk), dev, sk, 580 &sfilter, 1); 581 else 582 err = raw_enable_filters(sock_net(sk), dev, sk, 583 filter, count); 584 if (err) { 585 if (count > 1) 586 kfree(filter); 587 goto out_fil; 588 } 589 590 /* remove old filter registrations */ 591 raw_disable_filters(sock_net(sk), dev, sk, ro->filter, 592 ro->count); 593 } 594 595 /* remove old filter space */ 596 if (ro->count > 1) 597 kfree(ro->filter); 598 599 /* link new filters to the socket */ 600 if (count == 1) { 601 /* copy filter data for single filter */ 602 ro->dfilter = sfilter; 603 filter = &ro->dfilter; 604 } 605 ro->filter = filter; 606 ro->count = count; 607 608 out_fil: 609 release_sock(sk); 610 rtnl_unlock(); 611 612 break; 613 614 case CAN_RAW_ERR_FILTER: 615 if (optlen != sizeof(err_mask)) 616 return -EINVAL; 617 618 if (copy_from_sockptr(&err_mask, optval, optlen)) 619 return -EFAULT; 620 621 err_mask &= CAN_ERR_MASK; 622 623 rtnl_lock(); 624 lock_sock(sk); 625 626 dev = ro->dev; 627 if (ro->bound && dev) { 628 if (dev->reg_state != NETREG_REGISTERED) { 629 err = -ENODEV; 630 goto out_err; 631 } 632 } 633 634 /* remove current error mask */ 635 if (ro->bound) { 636 /* (try to) register the new err_mask */ 637 err = raw_enable_errfilter(sock_net(sk), dev, sk, 638 err_mask); 639 640 if (err) 641 goto out_err; 642 643 /* remove old err_mask registration */ 644 raw_disable_errfilter(sock_net(sk), dev, sk, 645 ro->err_mask); 646 } 647 648 /* link new err_mask to the socket */ 649 ro->err_mask = err_mask; 650 651 out_err: 652 release_sock(sk); 653 rtnl_unlock(); 654 655 break; 656 657 case CAN_RAW_LOOPBACK: 658 if (optlen != sizeof(ro->loopback)) 659 return -EINVAL; 660 661 if (copy_from_sockptr(&ro->loopback, optval, optlen)) 662 return -EFAULT; 663 664 break; 665 666 case CAN_RAW_RECV_OWN_MSGS: 667 if (optlen != sizeof(ro->recv_own_msgs)) 668 return -EINVAL; 669 670 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen)) 671 return -EFAULT; 672 673 break; 674 675 case CAN_RAW_FD_FRAMES: 676 if (optlen != sizeof(fd_frames)) 677 return -EINVAL; 678 679 if (copy_from_sockptr(&fd_frames, optval, optlen)) 680 return -EFAULT; 681 682 /* Enabling CAN XL includes CAN FD */ 683 if (ro->xl_frames && !fd_frames) 684 return -EINVAL; 685 686 ro->fd_frames = fd_frames; 687 break; 688 689 case CAN_RAW_XL_FRAMES: 690 if (optlen != sizeof(ro->xl_frames)) 691 return -EINVAL; 692 693 if (copy_from_sockptr(&ro->xl_frames, optval, optlen)) 694 return -EFAULT; 695 696 /* Enabling CAN XL includes CAN FD */ 697 if (ro->xl_frames) 698 ro->fd_frames = ro->xl_frames; 699 break; 700 701 case CAN_RAW_JOIN_FILTERS: 702 if (optlen != sizeof(ro->join_filters)) 703 return -EINVAL; 704 705 if (copy_from_sockptr(&ro->join_filters, optval, optlen)) 706 return -EFAULT; 707 708 break; 709 710 default: 711 return -ENOPROTOOPT; 712 } 713 return err; 714 } 715 716 static int raw_getsockopt(struct socket *sock, int level, int optname, 717 char __user *optval, int __user *optlen) 718 { 719 struct sock *sk = sock->sk; 720 struct raw_sock *ro = raw_sk(sk); 721 int len; 722 void *val; 723 int err = 0; 724 725 if (level != SOL_CAN_RAW) 726 return -EINVAL; 727 if (get_user(len, optlen)) 728 return -EFAULT; 729 if (len < 0) 730 return -EINVAL; 731 732 switch (optname) { 733 case CAN_RAW_FILTER: 734 lock_sock(sk); 735 if (ro->count > 0) { 736 int fsize = ro->count * sizeof(struct can_filter); 737 738 /* user space buffer to small for filter list? */ 739 if (len < fsize) { 740 /* return -ERANGE and needed space in optlen */ 741 err = -ERANGE; 742 if (put_user(fsize, optlen)) 743 err = -EFAULT; 744 } else { 745 if (len > fsize) 746 len = fsize; 747 if (copy_to_user(optval, ro->filter, len)) 748 err = -EFAULT; 749 } 750 } else { 751 len = 0; 752 } 753 release_sock(sk); 754 755 if (!err) 756 err = put_user(len, optlen); 757 return err; 758 759 case CAN_RAW_ERR_FILTER: 760 if (len > sizeof(can_err_mask_t)) 761 len = sizeof(can_err_mask_t); 762 val = &ro->err_mask; 763 break; 764 765 case CAN_RAW_LOOPBACK: 766 if (len > sizeof(int)) 767 len = sizeof(int); 768 val = &ro->loopback; 769 break; 770 771 case CAN_RAW_RECV_OWN_MSGS: 772 if (len > sizeof(int)) 773 len = sizeof(int); 774 val = &ro->recv_own_msgs; 775 break; 776 777 case CAN_RAW_FD_FRAMES: 778 if (len > sizeof(int)) 779 len = sizeof(int); 780 val = &ro->fd_frames; 781 break; 782 783 case CAN_RAW_XL_FRAMES: 784 if (len > sizeof(int)) 785 len = sizeof(int); 786 val = &ro->xl_frames; 787 break; 788 789 case CAN_RAW_JOIN_FILTERS: 790 if (len > sizeof(int)) 791 len = sizeof(int); 792 val = &ro->join_filters; 793 break; 794 795 default: 796 return -ENOPROTOOPT; 797 } 798 799 if (put_user(len, optlen)) 800 return -EFAULT; 801 if (copy_to_user(optval, val, len)) 802 return -EFAULT; 803 return 0; 804 } 805 806 static bool raw_bad_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu) 807 { 808 /* Classical CAN -> no checks for flags and device capabilities */ 809 if (can_is_can_skb(skb)) 810 return false; 811 812 /* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */ 813 if (ro->fd_frames && can_is_canfd_skb(skb) && 814 (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu))) 815 return false; 816 817 /* CAN XL -> needs to be enabled and a CAN XL device */ 818 if (ro->xl_frames && can_is_canxl_skb(skb) && 819 can_is_canxl_dev_mtu(mtu)) 820 return false; 821 822 return true; 823 } 824 825 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 826 { 827 struct sock *sk = sock->sk; 828 struct raw_sock *ro = raw_sk(sk); 829 struct sockcm_cookie sockc; 830 struct sk_buff *skb; 831 struct net_device *dev; 832 int ifindex; 833 int err = -EINVAL; 834 835 /* check for valid CAN frame sizes */ 836 if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU) 837 return -EINVAL; 838 839 if (msg->msg_name) { 840 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 841 842 if (msg->msg_namelen < RAW_MIN_NAMELEN) 843 return -EINVAL; 844 845 if (addr->can_family != AF_CAN) 846 return -EINVAL; 847 848 ifindex = addr->can_ifindex; 849 } else { 850 ifindex = ro->ifindex; 851 } 852 853 dev = dev_get_by_index(sock_net(sk), ifindex); 854 if (!dev) 855 return -ENXIO; 856 857 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), 858 msg->msg_flags & MSG_DONTWAIT, &err); 859 if (!skb) 860 goto put_dev; 861 862 can_skb_reserve(skb); 863 can_skb_prv(skb)->ifindex = dev->ifindex; 864 can_skb_prv(skb)->skbcnt = 0; 865 866 /* fill the skb before testing for valid CAN frames */ 867 err = memcpy_from_msg(skb_put(skb, size), msg, size); 868 if (err < 0) 869 goto free_skb; 870 871 err = -EINVAL; 872 if (raw_bad_txframe(ro, skb, dev->mtu)) 873 goto free_skb; 874 875 sockcm_init(&sockc, sk); 876 if (msg->msg_controllen) { 877 err = sock_cmsg_send(sk, msg, &sockc); 878 if (unlikely(err)) 879 goto free_skb; 880 } 881 882 skb->dev = dev; 883 skb->priority = READ_ONCE(sk->sk_priority); 884 skb->mark = READ_ONCE(sk->sk_mark); 885 skb->tstamp = sockc.transmit_time; 886 887 skb_setup_tx_timestamp(skb, sockc.tsflags); 888 889 err = can_send(skb, ro->loopback); 890 891 dev_put(dev); 892 893 if (err) 894 goto send_failed; 895 896 return size; 897 898 free_skb: 899 kfree_skb(skb); 900 put_dev: 901 dev_put(dev); 902 send_failed: 903 return err; 904 } 905 906 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 907 int flags) 908 { 909 struct sock *sk = sock->sk; 910 struct sk_buff *skb; 911 int err = 0; 912 913 if (flags & MSG_ERRQUEUE) 914 return sock_recv_errqueue(sk, msg, size, 915 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE); 916 917 skb = skb_recv_datagram(sk, flags, &err); 918 if (!skb) 919 return err; 920 921 if (size < skb->len) 922 msg->msg_flags |= MSG_TRUNC; 923 else 924 size = skb->len; 925 926 err = memcpy_to_msg(msg, skb->data, size); 927 if (err < 0) { 928 skb_free_datagram(sk, skb); 929 return err; 930 } 931 932 sock_recv_cmsgs(msg, sk, skb); 933 934 if (msg->msg_name) { 935 __sockaddr_check_size(RAW_MIN_NAMELEN); 936 msg->msg_namelen = RAW_MIN_NAMELEN; 937 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 938 } 939 940 /* assign the flags that have been recorded in raw_rcv() */ 941 msg->msg_flags |= *(raw_flags(skb)); 942 943 skb_free_datagram(sk, skb); 944 945 return size; 946 } 947 948 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 949 unsigned long arg) 950 { 951 /* no ioctls for socket layer -> hand it down to NIC layer */ 952 return -ENOIOCTLCMD; 953 } 954 955 static const struct proto_ops raw_ops = { 956 .family = PF_CAN, 957 .release = raw_release, 958 .bind = raw_bind, 959 .connect = sock_no_connect, 960 .socketpair = sock_no_socketpair, 961 .accept = sock_no_accept, 962 .getname = raw_getname, 963 .poll = datagram_poll, 964 .ioctl = raw_sock_no_ioctlcmd, 965 .gettstamp = sock_gettstamp, 966 .listen = sock_no_listen, 967 .shutdown = sock_no_shutdown, 968 .setsockopt = raw_setsockopt, 969 .getsockopt = raw_getsockopt, 970 .sendmsg = raw_sendmsg, 971 .recvmsg = raw_recvmsg, 972 .mmap = sock_no_mmap, 973 }; 974 975 static struct proto raw_proto __read_mostly = { 976 .name = "CAN_RAW", 977 .owner = THIS_MODULE, 978 .obj_size = sizeof(struct raw_sock), 979 .init = raw_init, 980 }; 981 982 static const struct can_proto raw_can_proto = { 983 .type = SOCK_RAW, 984 .protocol = CAN_RAW, 985 .ops = &raw_ops, 986 .prot = &raw_proto, 987 }; 988 989 static struct notifier_block canraw_notifier = { 990 .notifier_call = raw_notifier 991 }; 992 993 static __init int raw_module_init(void) 994 { 995 int err; 996 997 pr_info("can: raw protocol\n"); 998 999 err = register_netdevice_notifier(&canraw_notifier); 1000 if (err) 1001 return err; 1002 1003 err = can_proto_register(&raw_can_proto); 1004 if (err < 0) { 1005 pr_err("can: registration of raw protocol failed\n"); 1006 goto register_proto_failed; 1007 } 1008 1009 return 0; 1010 1011 register_proto_failed: 1012 unregister_netdevice_notifier(&canraw_notifier); 1013 return err; 1014 } 1015 1016 static __exit void raw_module_exit(void) 1017 { 1018 can_proto_unregister(&raw_can_proto); 1019 unregister_netdevice_notifier(&canraw_notifier); 1020 } 1021 1022 module_init(raw_module_init); 1023 module_exit(raw_module_exit); 1024