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 const struct sk_buff *skb; 79 int skbcnt; 80 unsigned int join_rx_count; 81 }; 82 83 struct raw_sock { 84 struct sock sk; 85 struct net_device *dev; 86 netdevice_tracker dev_tracker; 87 struct list_head notifier; 88 int ifindex; 89 unsigned int bound:1; 90 unsigned int loopback:1; 91 unsigned int recv_own_msgs:1; 92 unsigned int fd_frames:1; 93 unsigned int xl_frames:1; 94 unsigned int join_filters:1; 95 struct can_raw_vcid_options raw_vcid_opts; 96 canid_t tx_vcid_shifted; 97 canid_t rx_vcid_shifted; 98 canid_t rx_vcid_mask_shifted; 99 can_err_mask_t err_mask; 100 int count; /* number of active filters */ 101 struct can_filter dfilter; /* default/single filter */ 102 struct can_filter *filter; /* pointer to filter(s) */ 103 struct uniqframe __percpu *uniq; 104 }; 105 106 static LIST_HEAD(raw_notifier_list); 107 static DEFINE_SPINLOCK(raw_notifier_lock); 108 static struct raw_sock *raw_busy_notifier; 109 110 /* Return pointer to store the extra msg flags for raw_recvmsg(). 111 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 112 * in skb->cb. 113 */ 114 static inline unsigned int *raw_flags(struct sk_buff *skb) 115 { 116 sock_skb_cb_check_size(sizeof(struct sockaddr_can) + 117 sizeof(unsigned int)); 118 119 /* return pointer after struct sockaddr_can */ 120 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 121 } 122 123 static inline struct raw_sock *raw_sk(const struct sock *sk) 124 { 125 return (struct raw_sock *)sk; 126 } 127 128 static void raw_rcv(struct sk_buff *oskb, void *data) 129 { 130 struct sock *sk = (struct sock *)data; 131 struct raw_sock *ro = raw_sk(sk); 132 enum skb_drop_reason reason; 133 struct sockaddr_can *addr; 134 struct sk_buff *skb; 135 unsigned int *pflags; 136 137 /* check the received tx sock reference */ 138 if (!ro->recv_own_msgs && oskb->sk == sk) 139 return; 140 141 /* make sure to not pass oversized frames to the socket */ 142 if (!ro->fd_frames && can_is_canfd_skb(oskb)) 143 return; 144 145 if (can_is_canxl_skb(oskb)) { 146 struct canxl_frame *cxl = (struct canxl_frame *)oskb->data; 147 148 /* make sure to not pass oversized frames to the socket */ 149 if (!ro->xl_frames) 150 return; 151 152 /* filter CAN XL VCID content */ 153 if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_RX_FILTER) { 154 /* apply VCID filter if user enabled the filter */ 155 if ((cxl->prio & ro->rx_vcid_mask_shifted) != 156 (ro->rx_vcid_shifted & ro->rx_vcid_mask_shifted)) 157 return; 158 } else { 159 /* no filter => do not forward VCID tagged frames */ 160 if (cxl->prio & CANXL_VCID_MASK) 161 return; 162 } 163 } 164 165 /* eliminate multiple filter matches for the same skb */ 166 if (this_cpu_ptr(ro->uniq)->skb == oskb && 167 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { 168 if (!ro->join_filters) 169 return; 170 171 this_cpu_inc(ro->uniq->join_rx_count); 172 /* drop frame until all enabled filters matched */ 173 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) 174 return; 175 } else { 176 this_cpu_ptr(ro->uniq)->skb = oskb; 177 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; 178 this_cpu_ptr(ro->uniq)->join_rx_count = 1; 179 /* drop first frame to check all enabled filters? */ 180 if (ro->join_filters && ro->count > 1) 181 return; 182 } 183 184 /* clone the given skb to be able to enqueue it into the rcv queue */ 185 skb = skb_clone(oskb, GFP_ATOMIC); 186 if (!skb) 187 return; 188 189 /* Put the datagram to the queue so that raw_recvmsg() can get 190 * it from there. We need to pass the interface index to 191 * raw_recvmsg(). We pass a whole struct sockaddr_can in 192 * skb->cb containing the interface index. 193 */ 194 195 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 196 addr = (struct sockaddr_can *)skb->cb; 197 memset(addr, 0, sizeof(*addr)); 198 addr->can_family = AF_CAN; 199 addr->can_ifindex = skb->dev->ifindex; 200 201 /* add CAN specific message flags for raw_recvmsg() */ 202 pflags = raw_flags(skb); 203 *pflags = 0; 204 if (oskb->sk) 205 *pflags |= MSG_DONTROUTE; 206 if (oskb->sk == sk) 207 *pflags |= MSG_CONFIRM; 208 209 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) 210 sk_skb_reason_drop(sk, skb, reason); 211 } 212 213 static int raw_enable_filters(struct net *net, struct net_device *dev, 214 struct sock *sk, struct can_filter *filter, 215 int count) 216 { 217 int err = 0; 218 int i; 219 220 for (i = 0; i < count; i++) { 221 err = can_rx_register(net, dev, filter[i].can_id, 222 filter[i].can_mask, 223 raw_rcv, sk, "raw", sk); 224 if (err) { 225 /* clean up successfully registered filters */ 226 while (--i >= 0) 227 can_rx_unregister(net, dev, filter[i].can_id, 228 filter[i].can_mask, 229 raw_rcv, sk); 230 break; 231 } 232 } 233 234 return err; 235 } 236 237 static int raw_enable_errfilter(struct net *net, struct net_device *dev, 238 struct sock *sk, can_err_mask_t err_mask) 239 { 240 int err = 0; 241 242 if (err_mask) 243 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG, 244 raw_rcv, sk, "raw", sk); 245 246 return err; 247 } 248 249 static void raw_disable_filters(struct net *net, struct net_device *dev, 250 struct sock *sk, struct can_filter *filter, 251 int count) 252 { 253 int i; 254 255 for (i = 0; i < count; i++) 256 can_rx_unregister(net, dev, filter[i].can_id, 257 filter[i].can_mask, raw_rcv, sk); 258 } 259 260 static inline void raw_disable_errfilter(struct net *net, 261 struct net_device *dev, 262 struct sock *sk, 263 can_err_mask_t err_mask) 264 265 { 266 if (err_mask) 267 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG, 268 raw_rcv, sk); 269 } 270 271 static inline void raw_disable_allfilters(struct net *net, 272 struct net_device *dev, 273 struct sock *sk) 274 { 275 struct raw_sock *ro = raw_sk(sk); 276 277 raw_disable_filters(net, dev, sk, ro->filter, ro->count); 278 raw_disable_errfilter(net, dev, sk, ro->err_mask); 279 } 280 281 static int raw_enable_allfilters(struct net *net, struct net_device *dev, 282 struct sock *sk) 283 { 284 struct raw_sock *ro = raw_sk(sk); 285 int err; 286 287 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count); 288 if (!err) { 289 err = raw_enable_errfilter(net, dev, sk, ro->err_mask); 290 if (err) 291 raw_disable_filters(net, dev, sk, ro->filter, 292 ro->count); 293 } 294 295 return err; 296 } 297 298 static void raw_notify(struct raw_sock *ro, unsigned long msg, 299 struct net_device *dev) 300 { 301 struct sock *sk = &ro->sk; 302 303 if (!net_eq(dev_net(dev), sock_net(sk))) 304 return; 305 306 if (ro->dev != dev) 307 return; 308 309 switch (msg) { 310 case NETDEV_UNREGISTER: 311 lock_sock(sk); 312 /* remove current filters & unregister */ 313 if (ro->bound) { 314 raw_disable_allfilters(dev_net(dev), dev, sk); 315 netdev_put(dev, &ro->dev_tracker); 316 } 317 318 if (ro->count > 1) 319 kfree(ro->filter); 320 321 ro->ifindex = 0; 322 ro->bound = 0; 323 ro->dev = NULL; 324 ro->count = 0; 325 release_sock(sk); 326 327 sk->sk_err = ENODEV; 328 if (!sock_flag(sk, SOCK_DEAD)) 329 sk_error_report(sk); 330 break; 331 332 case NETDEV_DOWN: 333 sk->sk_err = ENETDOWN; 334 if (!sock_flag(sk, SOCK_DEAD)) 335 sk_error_report(sk); 336 break; 337 } 338 } 339 340 static int raw_notifier(struct notifier_block *nb, unsigned long msg, 341 void *ptr) 342 { 343 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 344 345 if (dev->type != ARPHRD_CAN) 346 return NOTIFY_DONE; 347 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 348 return NOTIFY_DONE; 349 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */ 350 return NOTIFY_DONE; 351 352 spin_lock(&raw_notifier_lock); 353 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) { 354 spin_unlock(&raw_notifier_lock); 355 raw_notify(raw_busy_notifier, msg, dev); 356 spin_lock(&raw_notifier_lock); 357 } 358 raw_busy_notifier = NULL; 359 spin_unlock(&raw_notifier_lock); 360 return NOTIFY_DONE; 361 } 362 363 static int raw_init(struct sock *sk) 364 { 365 struct raw_sock *ro = raw_sk(sk); 366 367 ro->bound = 0; 368 ro->ifindex = 0; 369 ro->dev = NULL; 370 371 /* set default filter to single entry dfilter */ 372 ro->dfilter.can_id = 0; 373 ro->dfilter.can_mask = MASK_ALL; 374 ro->filter = &ro->dfilter; 375 ro->count = 1; 376 377 /* set default loopback behaviour */ 378 ro->loopback = 1; 379 ro->recv_own_msgs = 0; 380 ro->fd_frames = 0; 381 ro->xl_frames = 0; 382 ro->join_filters = 0; 383 384 /* alloc_percpu provides zero'ed memory */ 385 ro->uniq = alloc_percpu(struct uniqframe); 386 if (unlikely(!ro->uniq)) 387 return -ENOMEM; 388 389 /* set notifier */ 390 spin_lock(&raw_notifier_lock); 391 list_add_tail(&ro->notifier, &raw_notifier_list); 392 spin_unlock(&raw_notifier_lock); 393 394 return 0; 395 } 396 397 static int raw_release(struct socket *sock) 398 { 399 struct sock *sk = sock->sk; 400 struct raw_sock *ro; 401 struct net *net; 402 403 if (!sk) 404 return 0; 405 406 ro = raw_sk(sk); 407 net = sock_net(sk); 408 409 spin_lock(&raw_notifier_lock); 410 while (raw_busy_notifier == ro) { 411 spin_unlock(&raw_notifier_lock); 412 schedule_timeout_uninterruptible(1); 413 spin_lock(&raw_notifier_lock); 414 } 415 list_del(&ro->notifier); 416 spin_unlock(&raw_notifier_lock); 417 418 rtnl_lock(); 419 lock_sock(sk); 420 421 /* remove current filters & unregister */ 422 if (ro->bound) { 423 if (ro->dev) { 424 raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk); 425 netdev_put(ro->dev, &ro->dev_tracker); 426 } else { 427 raw_disable_allfilters(net, NULL, sk); 428 } 429 } 430 431 if (ro->count > 1) 432 kfree(ro->filter); 433 434 ro->ifindex = 0; 435 ro->bound = 0; 436 ro->dev = NULL; 437 ro->count = 0; 438 free_percpu(ro->uniq); 439 440 sock_orphan(sk); 441 sock->sk = NULL; 442 443 release_sock(sk); 444 rtnl_unlock(); 445 446 sock_prot_inuse_add(net, sk->sk_prot, -1); 447 sock_put(sk); 448 449 return 0; 450 } 451 452 static int raw_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len) 453 { 454 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 455 struct sock *sk = sock->sk; 456 struct raw_sock *ro = raw_sk(sk); 457 struct net_device *dev = NULL; 458 int ifindex; 459 int err = 0; 460 int notify_enetdown = 0; 461 462 if (len < RAW_MIN_NAMELEN) 463 return -EINVAL; 464 if (addr->can_family != AF_CAN) 465 return -EINVAL; 466 467 rtnl_lock(); 468 lock_sock(sk); 469 470 if (ro->bound && addr->can_ifindex == ro->ifindex) 471 goto out; 472 473 if (addr->can_ifindex) { 474 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); 475 if (!dev) { 476 err = -ENODEV; 477 goto out; 478 } 479 if (dev->type != ARPHRD_CAN) { 480 err = -ENODEV; 481 goto out_put_dev; 482 } 483 484 if (!(dev->flags & IFF_UP)) 485 notify_enetdown = 1; 486 487 ifindex = dev->ifindex; 488 489 /* filters set by default/setsockopt */ 490 err = raw_enable_allfilters(sock_net(sk), dev, sk); 491 if (err) 492 goto out_put_dev; 493 494 } else { 495 ifindex = 0; 496 497 /* filters set by default/setsockopt */ 498 err = raw_enable_allfilters(sock_net(sk), NULL, sk); 499 } 500 501 if (!err) { 502 if (ro->bound) { 503 /* unregister old filters */ 504 if (ro->dev) { 505 raw_disable_allfilters(dev_net(ro->dev), 506 ro->dev, sk); 507 /* drop reference to old ro->dev */ 508 netdev_put(ro->dev, &ro->dev_tracker); 509 } else { 510 raw_disable_allfilters(sock_net(sk), NULL, sk); 511 } 512 } 513 ro->ifindex = ifindex; 514 ro->bound = 1; 515 /* bind() ok -> hold a reference for new ro->dev */ 516 ro->dev = dev; 517 if (ro->dev) 518 netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL); 519 } 520 521 out_put_dev: 522 /* remove potential reference from dev_get_by_index() */ 523 dev_put(dev); 524 out: 525 release_sock(sk); 526 rtnl_unlock(); 527 528 if (notify_enetdown) { 529 sk->sk_err = ENETDOWN; 530 if (!sock_flag(sk, SOCK_DEAD)) 531 sk_error_report(sk); 532 } 533 534 return err; 535 } 536 537 static int raw_getname(struct socket *sock, struct sockaddr *uaddr, 538 int peer) 539 { 540 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 541 struct sock *sk = sock->sk; 542 struct raw_sock *ro = raw_sk(sk); 543 544 if (peer) 545 return -EOPNOTSUPP; 546 547 memset(addr, 0, RAW_MIN_NAMELEN); 548 addr->can_family = AF_CAN; 549 addr->can_ifindex = ro->ifindex; 550 551 return RAW_MIN_NAMELEN; 552 } 553 554 static int raw_setsockopt(struct socket *sock, int level, int optname, 555 sockptr_t optval, unsigned int optlen) 556 { 557 struct sock *sk = sock->sk; 558 struct raw_sock *ro = raw_sk(sk); 559 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */ 560 struct can_filter sfilter; /* single filter */ 561 struct net_device *dev = NULL; 562 can_err_mask_t err_mask = 0; 563 int count = 0; 564 int flag; 565 int err = 0; 566 567 if (level != SOL_CAN_RAW) 568 return -EINVAL; 569 570 switch (optname) { 571 case CAN_RAW_FILTER: 572 if (optlen % sizeof(struct can_filter) != 0) 573 return -EINVAL; 574 575 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter)) 576 return -EINVAL; 577 578 count = optlen / sizeof(struct can_filter); 579 580 if (count > 1) { 581 /* filter does not fit into dfilter => alloc space */ 582 filter = memdup_sockptr(optval, optlen); 583 if (IS_ERR(filter)) 584 return PTR_ERR(filter); 585 } else if (count == 1) { 586 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter))) 587 return -EFAULT; 588 } 589 590 rtnl_lock(); 591 lock_sock(sk); 592 593 dev = ro->dev; 594 if (ro->bound && dev) { 595 if (dev->reg_state != NETREG_REGISTERED) { 596 if (count > 1) 597 kfree(filter); 598 err = -ENODEV; 599 goto out_fil; 600 } 601 } 602 603 if (ro->bound) { 604 /* (try to) register the new filters */ 605 if (count == 1) 606 err = raw_enable_filters(sock_net(sk), dev, sk, 607 &sfilter, 1); 608 else 609 err = raw_enable_filters(sock_net(sk), dev, sk, 610 filter, count); 611 if (err) { 612 if (count > 1) 613 kfree(filter); 614 goto out_fil; 615 } 616 617 /* remove old filter registrations */ 618 raw_disable_filters(sock_net(sk), dev, sk, ro->filter, 619 ro->count); 620 } 621 622 /* remove old filter space */ 623 if (ro->count > 1) 624 kfree(ro->filter); 625 626 /* link new filters to the socket */ 627 if (count == 1) { 628 /* copy filter data for single filter */ 629 ro->dfilter = sfilter; 630 filter = &ro->dfilter; 631 } 632 ro->filter = filter; 633 ro->count = count; 634 635 out_fil: 636 release_sock(sk); 637 rtnl_unlock(); 638 639 break; 640 641 case CAN_RAW_ERR_FILTER: 642 if (optlen != sizeof(err_mask)) 643 return -EINVAL; 644 645 if (copy_from_sockptr(&err_mask, optval, optlen)) 646 return -EFAULT; 647 648 err_mask &= CAN_ERR_MASK; 649 650 rtnl_lock(); 651 lock_sock(sk); 652 653 dev = ro->dev; 654 if (ro->bound && dev) { 655 if (dev->reg_state != NETREG_REGISTERED) { 656 err = -ENODEV; 657 goto out_err; 658 } 659 } 660 661 /* remove current error mask */ 662 if (ro->bound) { 663 /* (try to) register the new err_mask */ 664 err = raw_enable_errfilter(sock_net(sk), dev, sk, 665 err_mask); 666 667 if (err) 668 goto out_err; 669 670 /* remove old err_mask registration */ 671 raw_disable_errfilter(sock_net(sk), dev, sk, 672 ro->err_mask); 673 } 674 675 /* link new err_mask to the socket */ 676 ro->err_mask = err_mask; 677 678 out_err: 679 release_sock(sk); 680 rtnl_unlock(); 681 682 break; 683 684 case CAN_RAW_LOOPBACK: 685 if (optlen != sizeof(flag)) 686 return -EINVAL; 687 688 if (copy_from_sockptr(&flag, optval, optlen)) 689 return -EFAULT; 690 691 ro->loopback = !!flag; 692 break; 693 694 case CAN_RAW_RECV_OWN_MSGS: 695 if (optlen != sizeof(flag)) 696 return -EINVAL; 697 698 if (copy_from_sockptr(&flag, optval, optlen)) 699 return -EFAULT; 700 701 ro->recv_own_msgs = !!flag; 702 break; 703 704 case CAN_RAW_FD_FRAMES: 705 if (optlen != sizeof(flag)) 706 return -EINVAL; 707 708 if (copy_from_sockptr(&flag, optval, optlen)) 709 return -EFAULT; 710 711 /* Enabling CAN XL includes CAN FD */ 712 if (ro->xl_frames && !flag) 713 return -EINVAL; 714 715 ro->fd_frames = !!flag; 716 break; 717 718 case CAN_RAW_XL_FRAMES: 719 if (optlen != sizeof(flag)) 720 return -EINVAL; 721 722 if (copy_from_sockptr(&flag, optval, optlen)) 723 return -EFAULT; 724 725 ro->xl_frames = !!flag; 726 727 /* Enabling CAN XL includes CAN FD */ 728 if (ro->xl_frames) 729 ro->fd_frames = ro->xl_frames; 730 break; 731 732 case CAN_RAW_XL_VCID_OPTS: 733 if (optlen != sizeof(ro->raw_vcid_opts)) 734 return -EINVAL; 735 736 if (copy_from_sockptr(&ro->raw_vcid_opts, optval, optlen)) 737 return -EFAULT; 738 739 /* prepare 32 bit values for handling in hot path */ 740 ro->tx_vcid_shifted = ro->raw_vcid_opts.tx_vcid << CANXL_VCID_OFFSET; 741 ro->rx_vcid_shifted = ro->raw_vcid_opts.rx_vcid << CANXL_VCID_OFFSET; 742 ro->rx_vcid_mask_shifted = ro->raw_vcid_opts.rx_vcid_mask << CANXL_VCID_OFFSET; 743 break; 744 745 case CAN_RAW_JOIN_FILTERS: 746 if (optlen != sizeof(flag)) 747 return -EINVAL; 748 749 if (copy_from_sockptr(&flag, optval, optlen)) 750 return -EFAULT; 751 752 ro->join_filters = !!flag; 753 break; 754 755 default: 756 return -ENOPROTOOPT; 757 } 758 return err; 759 } 760 761 static int raw_getsockopt(struct socket *sock, int level, int optname, 762 char __user *optval, int __user *optlen) 763 { 764 struct sock *sk = sock->sk; 765 struct raw_sock *ro = raw_sk(sk); 766 int flag; 767 int len; 768 void *val; 769 770 if (level != SOL_CAN_RAW) 771 return -EINVAL; 772 if (get_user(len, optlen)) 773 return -EFAULT; 774 if (len < 0) 775 return -EINVAL; 776 777 switch (optname) { 778 case CAN_RAW_FILTER: { 779 int err = 0; 780 781 lock_sock(sk); 782 if (ro->count > 0) { 783 int fsize = ro->count * sizeof(struct can_filter); 784 785 /* user space buffer to small for filter list? */ 786 if (len < fsize) { 787 /* return -ERANGE and needed space in optlen */ 788 err = -ERANGE; 789 if (put_user(fsize, optlen)) 790 err = -EFAULT; 791 } else { 792 if (len > fsize) 793 len = fsize; 794 if (copy_to_user(optval, ro->filter, len)) 795 err = -EFAULT; 796 } 797 } else { 798 len = 0; 799 } 800 release_sock(sk); 801 802 if (!err) 803 err = put_user(len, optlen); 804 return err; 805 } 806 case CAN_RAW_ERR_FILTER: 807 if (len > sizeof(can_err_mask_t)) 808 len = sizeof(can_err_mask_t); 809 val = &ro->err_mask; 810 break; 811 812 case CAN_RAW_LOOPBACK: 813 if (len > sizeof(int)) 814 len = sizeof(int); 815 flag = ro->loopback; 816 val = &flag; 817 break; 818 819 case CAN_RAW_RECV_OWN_MSGS: 820 if (len > sizeof(int)) 821 len = sizeof(int); 822 flag = ro->recv_own_msgs; 823 val = &flag; 824 break; 825 826 case CAN_RAW_FD_FRAMES: 827 if (len > sizeof(int)) 828 len = sizeof(int); 829 flag = ro->fd_frames; 830 val = &flag; 831 break; 832 833 case CAN_RAW_XL_FRAMES: 834 if (len > sizeof(int)) 835 len = sizeof(int); 836 flag = ro->xl_frames; 837 val = &flag; 838 break; 839 840 case CAN_RAW_XL_VCID_OPTS: { 841 int err = 0; 842 843 /* user space buffer to small for VCID opts? */ 844 if (len < sizeof(ro->raw_vcid_opts)) { 845 /* return -ERANGE and needed space in optlen */ 846 err = -ERANGE; 847 if (put_user(sizeof(ro->raw_vcid_opts), optlen)) 848 err = -EFAULT; 849 } else { 850 if (len > sizeof(ro->raw_vcid_opts)) 851 len = sizeof(ro->raw_vcid_opts); 852 if (copy_to_user(optval, &ro->raw_vcid_opts, len)) 853 err = -EFAULT; 854 } 855 if (!err) 856 err = put_user(len, optlen); 857 return err; 858 } 859 case CAN_RAW_JOIN_FILTERS: 860 if (len > sizeof(int)) 861 len = sizeof(int); 862 flag = ro->join_filters; 863 val = &flag; 864 break; 865 866 default: 867 return -ENOPROTOOPT; 868 } 869 870 if (put_user(len, optlen)) 871 return -EFAULT; 872 if (copy_to_user(optval, val, len)) 873 return -EFAULT; 874 return 0; 875 } 876 877 static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb) 878 { 879 struct canxl_frame *cxl = (struct canxl_frame *)skb->data; 880 881 /* sanitize non CAN XL bits */ 882 cxl->prio &= (CANXL_PRIO_MASK | CANXL_VCID_MASK); 883 884 /* clear VCID in CAN XL frame if pass through is disabled */ 885 if (!(ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_PASS)) 886 cxl->prio &= CANXL_PRIO_MASK; 887 888 /* set VCID in CAN XL frame if enabled */ 889 if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_SET) { 890 cxl->prio &= CANXL_PRIO_MASK; 891 cxl->prio |= ro->tx_vcid_shifted; 892 } 893 } 894 895 static inline bool raw_dev_cc_enabled(struct net_device *dev, 896 struct can_priv *priv) 897 { 898 /* The CANXL-only mode disables error-signalling on the CAN bus 899 * which is needed to send CAN CC/FD frames 900 */ 901 if (priv) 902 return !can_dev_in_xl_only_mode(priv); 903 904 /* virtual CAN interfaces always support CAN CC */ 905 return true; 906 } 907 908 static inline bool raw_dev_fd_enabled(struct net_device *dev, 909 struct can_priv *priv) 910 { 911 /* check FD ctrlmode on real CAN interfaces */ 912 if (priv) 913 return (priv->ctrlmode & CAN_CTRLMODE_FD); 914 915 /* check MTU for virtual CAN FD interfaces */ 916 return (READ_ONCE(dev->mtu) >= CANFD_MTU); 917 } 918 919 static inline bool raw_dev_xl_enabled(struct net_device *dev, 920 struct can_priv *priv) 921 { 922 /* check XL ctrlmode on real CAN interfaces */ 923 if (priv) 924 return (priv->ctrlmode & CAN_CTRLMODE_XL); 925 926 /* check MTU for virtual CAN XL interfaces */ 927 return can_is_canxl_dev_mtu(READ_ONCE(dev->mtu)); 928 } 929 930 static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, 931 struct net_device *dev) 932 { 933 struct can_priv *priv = safe_candev_priv(dev); 934 935 /* Classical CAN */ 936 if (can_is_can_skb(skb) && raw_dev_cc_enabled(dev, priv)) 937 return CAN_MTU; 938 939 /* CAN FD */ 940 if (ro->fd_frames && can_is_canfd_skb(skb) && 941 raw_dev_fd_enabled(dev, priv)) 942 return CANFD_MTU; 943 944 /* CAN XL */ 945 if (ro->xl_frames && can_is_canxl_skb(skb) && 946 raw_dev_xl_enabled(dev, priv)) 947 return CANXL_MTU; 948 949 return 0; 950 } 951 952 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 953 { 954 struct sock *sk = sock->sk; 955 struct raw_sock *ro = raw_sk(sk); 956 struct sockcm_cookie sockc; 957 struct sk_buff *skb; 958 struct net_device *dev; 959 unsigned int txmtu; 960 int ifindex; 961 int err = -EINVAL; 962 963 /* check for valid CAN frame sizes */ 964 if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU) 965 return -EINVAL; 966 967 if (msg->msg_name) { 968 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 969 970 if (msg->msg_namelen < RAW_MIN_NAMELEN) 971 return -EINVAL; 972 973 if (addr->can_family != AF_CAN) 974 return -EINVAL; 975 976 ifindex = addr->can_ifindex; 977 } else { 978 ifindex = ro->ifindex; 979 } 980 981 dev = dev_get_by_index(sock_net(sk), ifindex); 982 if (!dev) 983 return -ENXIO; 984 985 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), 986 msg->msg_flags & MSG_DONTWAIT, &err); 987 if (!skb) 988 goto put_dev; 989 990 can_skb_reserve(skb); 991 can_skb_prv(skb)->ifindex = dev->ifindex; 992 can_skb_prv(skb)->skbcnt = 0; 993 994 /* fill the skb before testing for valid CAN frames */ 995 err = memcpy_from_msg(skb_put(skb, size), msg, size); 996 if (err < 0) 997 goto free_skb; 998 999 err = -EINVAL; 1000 1001 /* check for valid CAN (CC/FD/XL) frame content */ 1002 txmtu = raw_check_txframe(ro, skb, dev); 1003 if (!txmtu) 1004 goto free_skb; 1005 1006 /* only CANXL: clear/forward/set VCID value */ 1007 if (txmtu == CANXL_MTU) 1008 raw_put_canxl_vcid(ro, skb); 1009 1010 sockcm_init(&sockc, sk); 1011 if (msg->msg_controllen) { 1012 err = sock_cmsg_send(sk, msg, &sockc); 1013 if (unlikely(err)) 1014 goto free_skb; 1015 } 1016 1017 skb->dev = dev; 1018 skb->priority = sockc.priority; 1019 skb->mark = sockc.mark; 1020 skb->tstamp = sockc.transmit_time; 1021 1022 skb_setup_tx_timestamp(skb, &sockc); 1023 1024 err = can_send(skb, ro->loopback); 1025 1026 dev_put(dev); 1027 1028 if (err) 1029 goto send_failed; 1030 1031 return size; 1032 1033 free_skb: 1034 kfree_skb(skb); 1035 put_dev: 1036 dev_put(dev); 1037 send_failed: 1038 return err; 1039 } 1040 1041 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1042 int flags) 1043 { 1044 struct sock *sk = sock->sk; 1045 struct sk_buff *skb; 1046 int err = 0; 1047 1048 if (flags & MSG_ERRQUEUE) 1049 return sock_recv_errqueue(sk, msg, size, 1050 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE); 1051 1052 skb = skb_recv_datagram(sk, flags, &err); 1053 if (!skb) 1054 return err; 1055 1056 if (size < skb->len) 1057 msg->msg_flags |= MSG_TRUNC; 1058 else 1059 size = skb->len; 1060 1061 err = memcpy_to_msg(msg, skb->data, size); 1062 if (err < 0) { 1063 skb_free_datagram(sk, skb); 1064 return err; 1065 } 1066 1067 sock_recv_cmsgs(msg, sk, skb); 1068 1069 if (msg->msg_name) { 1070 __sockaddr_check_size(RAW_MIN_NAMELEN); 1071 msg->msg_namelen = RAW_MIN_NAMELEN; 1072 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1073 } 1074 1075 /* assign the flags that have been recorded in raw_rcv() */ 1076 msg->msg_flags |= *(raw_flags(skb)); 1077 1078 skb_free_datagram(sk, skb); 1079 1080 return size; 1081 } 1082 1083 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1084 unsigned long arg) 1085 { 1086 /* no ioctls for socket layer -> hand it down to NIC layer */ 1087 return -ENOIOCTLCMD; 1088 } 1089 1090 static const struct proto_ops raw_ops = { 1091 .family = PF_CAN, 1092 .release = raw_release, 1093 .bind = raw_bind, 1094 .connect = sock_no_connect, 1095 .socketpair = sock_no_socketpair, 1096 .accept = sock_no_accept, 1097 .getname = raw_getname, 1098 .poll = datagram_poll, 1099 .ioctl = raw_sock_no_ioctlcmd, 1100 .gettstamp = sock_gettstamp, 1101 .listen = sock_no_listen, 1102 .shutdown = sock_no_shutdown, 1103 .setsockopt = raw_setsockopt, 1104 .getsockopt = raw_getsockopt, 1105 .sendmsg = raw_sendmsg, 1106 .recvmsg = raw_recvmsg, 1107 .mmap = sock_no_mmap, 1108 }; 1109 1110 static struct proto raw_proto __read_mostly = { 1111 .name = "CAN_RAW", 1112 .owner = THIS_MODULE, 1113 .obj_size = sizeof(struct raw_sock), 1114 .init = raw_init, 1115 }; 1116 1117 static const struct can_proto raw_can_proto = { 1118 .type = SOCK_RAW, 1119 .protocol = CAN_RAW, 1120 .ops = &raw_ops, 1121 .prot = &raw_proto, 1122 }; 1123 1124 static struct notifier_block canraw_notifier = { 1125 .notifier_call = raw_notifier 1126 }; 1127 1128 static __init int raw_module_init(void) 1129 { 1130 int err; 1131 1132 pr_info("can: raw protocol\n"); 1133 1134 err = register_netdevice_notifier(&canraw_notifier); 1135 if (err) 1136 return err; 1137 1138 err = can_proto_register(&raw_can_proto); 1139 if (err < 0) { 1140 pr_err("can: registration of raw protocol failed\n"); 1141 goto register_proto_failed; 1142 } 1143 1144 return 0; 1145 1146 register_proto_failed: 1147 unregister_netdevice_notifier(&canraw_notifier); 1148 return err; 1149 } 1150 1151 static __exit void raw_module_exit(void) 1152 { 1153 can_proto_unregister(&raw_can_proto); 1154 unregister_netdevice_notifier(&canraw_notifier); 1155 } 1156 1157 module_init(raw_module_init); 1158 module_exit(raw_module_exit); 1159