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 if (dev) 497 dev_put(dev); 498 out: 499 release_sock(sk); 500 rtnl_unlock(); 501 502 if (notify_enetdown) { 503 sk->sk_err = ENETDOWN; 504 if (!sock_flag(sk, SOCK_DEAD)) 505 sk_error_report(sk); 506 } 507 508 return err; 509 } 510 511 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 512 int peer) 513 { 514 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 515 struct sock *sk = sock->sk; 516 struct raw_sock *ro = raw_sk(sk); 517 518 if (peer) 519 return -EOPNOTSUPP; 520 521 memset(addr, 0, RAW_MIN_NAMELEN); 522 addr->can_family = AF_CAN; 523 addr->can_ifindex = ro->ifindex; 524 525 return RAW_MIN_NAMELEN; 526 } 527 528 static int raw_setsockopt(struct socket *sock, int level, int optname, 529 sockptr_t optval, unsigned int optlen) 530 { 531 struct sock *sk = sock->sk; 532 struct raw_sock *ro = raw_sk(sk); 533 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 534 struct can_filter sfilter; /* single filter */ 535 struct net_device *dev = NULL; 536 can_err_mask_t err_mask = 0; 537 int fd_frames; 538 int count = 0; 539 int err = 0; 540 541 if (level != SOL_CAN_RAW) 542 return -EINVAL; 543 544 switch (optname) { 545 case CAN_RAW_FILTER: 546 if (optlen % sizeof(struct can_filter) != 0) 547 return -EINVAL; 548 549 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) 550 return -EINVAL; 551 552 count = optlen / sizeof(struct can_filter); 553 554 if (count > 1) { 555 /* filter does not fit into dfilter => alloc space */ 556 filter = memdup_sockptr(optval, optlen); 557 if (IS_ERR(filter)) 558 return PTR_ERR(filter); 559 } else if (count == 1) { 560 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter))) 561 return -EFAULT; 562 } 563 564 rtnl_lock(); 565 lock_sock(sk); 566 567 dev = ro->dev; 568 if (ro->bound && dev) { 569 if (dev->reg_state != NETREG_REGISTERED) { 570 if (count > 1) 571 kfree(filter); 572 err = -ENODEV; 573 goto out_fil; 574 } 575 } 576 577 if (ro->bound) { 578 /* (try to) register the new filters */ 579 if (count == 1) 580 err = raw_enable_filters(sock_net(sk), dev, sk, 581 &sfilter, 1); 582 else 583 err = raw_enable_filters(sock_net(sk), dev, sk, 584 filter, count); 585 if (err) { 586 if (count > 1) 587 kfree(filter); 588 goto out_fil; 589 } 590 591 /* remove old filter registrations */ 592 raw_disable_filters(sock_net(sk), dev, sk, ro->filter, 593 ro->count); 594 } 595 596 /* remove old filter space */ 597 if (ro->count > 1) 598 kfree(ro->filter); 599 600 /* link new filters to the socket */ 601 if (count == 1) { 602 /* copy filter data for single filter */ 603 ro->dfilter = sfilter; 604 filter = &ro->dfilter; 605 } 606 ro->filter = filter; 607 ro->count = count; 608 609 out_fil: 610 release_sock(sk); 611 rtnl_unlock(); 612 613 break; 614 615 case CAN_RAW_ERR_FILTER: 616 if (optlen != sizeof(err_mask)) 617 return -EINVAL; 618 619 if (copy_from_sockptr(&err_mask, optval, optlen)) 620 return -EFAULT; 621 622 err_mask &= CAN_ERR_MASK; 623 624 rtnl_lock(); 625 lock_sock(sk); 626 627 dev = ro->dev; 628 if (ro->bound && dev) { 629 if (dev->reg_state != NETREG_REGISTERED) { 630 err = -ENODEV; 631 goto out_err; 632 } 633 } 634 635 /* remove current error mask */ 636 if (ro->bound) { 637 /* (try to) register the new err_mask */ 638 err = raw_enable_errfilter(sock_net(sk), dev, sk, 639 err_mask); 640 641 if (err) 642 goto out_err; 643 644 /* remove old err_mask registration */ 645 raw_disable_errfilter(sock_net(sk), dev, sk, 646 ro->err_mask); 647 } 648 649 /* link new err_mask to the socket */ 650 ro->err_mask = err_mask; 651 652 out_err: 653 release_sock(sk); 654 rtnl_unlock(); 655 656 break; 657 658 case CAN_RAW_LOOPBACK: 659 if (optlen != sizeof(ro->loopback)) 660 return -EINVAL; 661 662 if (copy_from_sockptr(&ro->loopback, optval, optlen)) 663 return -EFAULT; 664 665 break; 666 667 case CAN_RAW_RECV_OWN_MSGS: 668 if (optlen != sizeof(ro->recv_own_msgs)) 669 return -EINVAL; 670 671 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen)) 672 return -EFAULT; 673 674 break; 675 676 case CAN_RAW_FD_FRAMES: 677 if (optlen != sizeof(fd_frames)) 678 return -EINVAL; 679 680 if (copy_from_sockptr(&fd_frames, optval, optlen)) 681 return -EFAULT; 682 683 /* Enabling CAN XL includes CAN FD */ 684 if (ro->xl_frames && !fd_frames) 685 return -EINVAL; 686 687 ro->fd_frames = fd_frames; 688 break; 689 690 case CAN_RAW_XL_FRAMES: 691 if (optlen != sizeof(ro->xl_frames)) 692 return -EINVAL; 693 694 if (copy_from_sockptr(&ro->xl_frames, optval, optlen)) 695 return -EFAULT; 696 697 /* Enabling CAN XL includes CAN FD */ 698 if (ro->xl_frames) 699 ro->fd_frames = ro->xl_frames; 700 break; 701 702 case CAN_RAW_JOIN_FILTERS: 703 if (optlen != sizeof(ro->join_filters)) 704 return -EINVAL; 705 706 if (copy_from_sockptr(&ro->join_filters, optval, optlen)) 707 return -EFAULT; 708 709 break; 710 711 default: 712 return -ENOPROTOOPT; 713 } 714 return err; 715 } 716 717 static int raw_getsockopt(struct socket *sock, int level, int optname, 718 char __user *optval, int __user *optlen) 719 { 720 struct sock *sk = sock->sk; 721 struct raw_sock *ro = raw_sk(sk); 722 int len; 723 void *val; 724 int err = 0; 725 726 if (level != SOL_CAN_RAW) 727 return -EINVAL; 728 if (get_user(len, optlen)) 729 return -EFAULT; 730 if (len < 0) 731 return -EINVAL; 732 733 switch (optname) { 734 case CAN_RAW_FILTER: 735 lock_sock(sk); 736 if (ro->count > 0) { 737 int fsize = ro->count * sizeof(struct can_filter); 738 739 /* user space buffer to small for filter list? */ 740 if (len < fsize) { 741 /* return -ERANGE and needed space in optlen */ 742 err = -ERANGE; 743 if (put_user(fsize, optlen)) 744 err = -EFAULT; 745 } else { 746 if (len > fsize) 747 len = fsize; 748 if (copy_to_user(optval, ro->filter, len)) 749 err = -EFAULT; 750 } 751 } else { 752 len = 0; 753 } 754 release_sock(sk); 755 756 if (!err) 757 err = put_user(len, optlen); 758 return err; 759 760 case CAN_RAW_ERR_FILTER: 761 if (len > sizeof(can_err_mask_t)) 762 len = sizeof(can_err_mask_t); 763 val = &ro->err_mask; 764 break; 765 766 case CAN_RAW_LOOPBACK: 767 if (len > sizeof(int)) 768 len = sizeof(int); 769 val = &ro->loopback; 770 break; 771 772 case CAN_RAW_RECV_OWN_MSGS: 773 if (len > sizeof(int)) 774 len = sizeof(int); 775 val = &ro->recv_own_msgs; 776 break; 777 778 case CAN_RAW_FD_FRAMES: 779 if (len > sizeof(int)) 780 len = sizeof(int); 781 val = &ro->fd_frames; 782 break; 783 784 case CAN_RAW_XL_FRAMES: 785 if (len > sizeof(int)) 786 len = sizeof(int); 787 val = &ro->xl_frames; 788 break; 789 790 case CAN_RAW_JOIN_FILTERS: 791 if (len > sizeof(int)) 792 len = sizeof(int); 793 val = &ro->join_filters; 794 break; 795 796 default: 797 return -ENOPROTOOPT; 798 } 799 800 if (put_user(len, optlen)) 801 return -EFAULT; 802 if (copy_to_user(optval, val, len)) 803 return -EFAULT; 804 return 0; 805 } 806 807 static bool raw_bad_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu) 808 { 809 /* Classical CAN -> no checks for flags and device capabilities */ 810 if (can_is_can_skb(skb)) 811 return false; 812 813 /* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */ 814 if (ro->fd_frames && can_is_canfd_skb(skb) && 815 (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu))) 816 return false; 817 818 /* CAN XL -> needs to be enabled and a CAN XL device */ 819 if (ro->xl_frames && can_is_canxl_skb(skb) && 820 can_is_canxl_dev_mtu(mtu)) 821 return false; 822 823 return true; 824 } 825 826 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 827 { 828 struct sock *sk = sock->sk; 829 struct raw_sock *ro = raw_sk(sk); 830 struct sockcm_cookie sockc; 831 struct sk_buff *skb; 832 struct net_device *dev; 833 int ifindex; 834 int err = -EINVAL; 835 836 /* check for valid CAN frame sizes */ 837 if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU) 838 return -EINVAL; 839 840 if (msg->msg_name) { 841 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 842 843 if (msg->msg_namelen < RAW_MIN_NAMELEN) 844 return -EINVAL; 845 846 if (addr->can_family != AF_CAN) 847 return -EINVAL; 848 849 ifindex = addr->can_ifindex; 850 } else { 851 ifindex = ro->ifindex; 852 } 853 854 dev = dev_get_by_index(sock_net(sk), ifindex); 855 if (!dev) 856 return -ENXIO; 857 858 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), 859 msg->msg_flags & MSG_DONTWAIT, &err); 860 if (!skb) 861 goto put_dev; 862 863 can_skb_reserve(skb); 864 can_skb_prv(skb)->ifindex = dev->ifindex; 865 can_skb_prv(skb)->skbcnt = 0; 866 867 /* fill the skb before testing for valid CAN frames */ 868 err = memcpy_from_msg(skb_put(skb, size), msg, size); 869 if (err < 0) 870 goto free_skb; 871 872 err = -EINVAL; 873 if (raw_bad_txframe(ro, skb, dev->mtu)) 874 goto free_skb; 875 876 sockcm_init(&sockc, sk); 877 if (msg->msg_controllen) { 878 err = sock_cmsg_send(sk, msg, &sockc); 879 if (unlikely(err)) 880 goto free_skb; 881 } 882 883 skb->dev = dev; 884 skb->priority = sk->sk_priority; 885 skb->mark = READ_ONCE(sk->sk_mark); 886 skb->tstamp = sockc.transmit_time; 887 888 skb_setup_tx_timestamp(skb, sockc.tsflags); 889 890 err = can_send(skb, ro->loopback); 891 892 dev_put(dev); 893 894 if (err) 895 goto send_failed; 896 897 return size; 898 899 free_skb: 900 kfree_skb(skb); 901 put_dev: 902 dev_put(dev); 903 send_failed: 904 return err; 905 } 906 907 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 908 int flags) 909 { 910 struct sock *sk = sock->sk; 911 struct sk_buff *skb; 912 int err = 0; 913 914 if (flags & MSG_ERRQUEUE) 915 return sock_recv_errqueue(sk, msg, size, 916 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE); 917 918 skb = skb_recv_datagram(sk, flags, &err); 919 if (!skb) 920 return err; 921 922 if (size < skb->len) 923 msg->msg_flags |= MSG_TRUNC; 924 else 925 size = skb->len; 926 927 err = memcpy_to_msg(msg, skb->data, size); 928 if (err < 0) { 929 skb_free_datagram(sk, skb); 930 return err; 931 } 932 933 sock_recv_cmsgs(msg, sk, skb); 934 935 if (msg->msg_name) { 936 __sockaddr_check_size(RAW_MIN_NAMELEN); 937 msg->msg_namelen = RAW_MIN_NAMELEN; 938 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 939 } 940 941 /* assign the flags that have been recorded in raw_rcv() */ 942 msg->msg_flags |= *(raw_flags(skb)); 943 944 skb_free_datagram(sk, skb); 945 946 return size; 947 } 948 949 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 950 unsigned long arg) 951 { 952 /* no ioctls for socket layer -> hand it down to NIC layer */ 953 return -ENOIOCTLCMD; 954 } 955 956 static const struct proto_ops raw_ops = { 957 .family = PF_CAN, 958 .release = raw_release, 959 .bind = raw_bind, 960 .connect = sock_no_connect, 961 .socketpair = sock_no_socketpair, 962 .accept = sock_no_accept, 963 .getname = raw_getname, 964 .poll = datagram_poll, 965 .ioctl = raw_sock_no_ioctlcmd, 966 .gettstamp = sock_gettstamp, 967 .listen = sock_no_listen, 968 .shutdown = sock_no_shutdown, 969 .setsockopt = raw_setsockopt, 970 .getsockopt = raw_getsockopt, 971 .sendmsg = raw_sendmsg, 972 .recvmsg = raw_recvmsg, 973 .mmap = sock_no_mmap, 974 }; 975 976 static struct proto raw_proto __read_mostly = { 977 .name = "CAN_RAW", 978 .owner = THIS_MODULE, 979 .obj_size = sizeof(struct raw_sock), 980 .init = raw_init, 981 }; 982 983 static const struct can_proto raw_can_proto = { 984 .type = SOCK_RAW, 985 .protocol = CAN_RAW, 986 .ops = &raw_ops, 987 .prot = &raw_proto, 988 }; 989 990 static struct notifier_block canraw_notifier = { 991 .notifier_call = raw_notifier 992 }; 993 994 static __init int raw_module_init(void) 995 { 996 int err; 997 998 pr_info("can: raw protocol\n"); 999 1000 err = register_netdevice_notifier(&canraw_notifier); 1001 if (err) 1002 return err; 1003 1004 err = can_proto_register(&raw_can_proto); 1005 if (err < 0) { 1006 pr_err("can: registration of raw protocol failed\n"); 1007 goto register_proto_failed; 1008 } 1009 1010 return 0; 1011 1012 register_proto_failed: 1013 unregister_netdevice_notifier(&canraw_notifier); 1014 return err; 1015 } 1016 1017 static __exit void raw_module_exit(void) 1018 { 1019 can_proto_unregister(&raw_can_proto); 1020 unregister_netdevice_notifier(&canraw_notifier); 1021 } 1022 1023 module_init(raw_module_init); 1024 module_exit(raw_module_exit); 1025