1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) 2 /* 3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content 4 * 5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of Volkswagen nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * Alternatively, provided that this notice is retained in full, this 21 * software may be distributed under the terms of the GNU General 22 * Public License ("GPL") version 2, in which case the provisions of the 23 * GPL apply INSTEAD OF those given above. 24 * 25 * The provided data structures and external interfaces from this code 26 * are not restricted to be used by modules with a GPL compatible license. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 39 * DAMAGE. 40 * 41 */ 42 43 #include <linux/module.h> 44 #include <linux/init.h> 45 #include <linux/interrupt.h> 46 #include <linux/hrtimer.h> 47 #include <linux/list.h> 48 #include <linux/proc_fs.h> 49 #include <linux/seq_file.h> 50 #include <linux/uio.h> 51 #include <linux/net.h> 52 #include <linux/netdevice.h> 53 #include <linux/socket.h> 54 #include <linux/if_arp.h> 55 #include <linux/skbuff.h> 56 #include <linux/can.h> 57 #include <linux/can/core.h> 58 #include <linux/can/skb.h> 59 #include <linux/can/bcm.h> 60 #include <linux/slab.h> 61 #include <net/sock.h> 62 #include <net/net_namespace.h> 63 64 /* 65 * To send multiple CAN frame content within TX_SETUP or to filter 66 * CAN messages with multiplex index within RX_SETUP, the number of 67 * different filters is limited to 256 due to the one byte index value. 68 */ 69 #define MAX_NFRAMES 256 70 71 /* limit timers to 400 days for sending/timeouts */ 72 #define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60) 73 74 /* use of last_frames[index].flags */ 75 #define RX_RECV 0x40 /* received data for this element */ 76 #define RX_THR 0x80 /* element not been sent due to throttle feature */ 77 #define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */ 78 79 /* get best masking value for can_rx_register() for a given single can_id */ 80 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ 81 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ 82 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) 83 84 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 85 MODULE_LICENSE("Dual BSD/GPL"); 86 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 87 MODULE_ALIAS("can-proto-2"); 88 89 #define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) 90 91 /* 92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is 93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured 94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler(). 95 */ 96 static inline u64 get_u64(const struct canfd_frame *cp, int offset) 97 { 98 return *(u64 *)(cp->data + offset); 99 } 100 101 struct bcm_op { 102 struct list_head list; 103 struct rcu_head rcu; 104 int ifindex; 105 canid_t can_id; 106 u32 flags; 107 unsigned long frames_abs, frames_filtered; 108 struct bcm_timeval ival1, ival2; 109 struct hrtimer timer, thrtimer; 110 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 111 int rx_ifindex; 112 int cfsiz; 113 u32 count; 114 u32 nframes; 115 u32 currframe; 116 /* void pointers to arrays of struct can[fd]_frame */ 117 void *frames; 118 void *last_frames; 119 struct canfd_frame sframe; 120 struct canfd_frame last_sframe; 121 struct sock *sk; 122 struct net_device *rx_reg_dev; 123 }; 124 125 struct bcm_sock { 126 struct sock sk; 127 int bound; 128 int ifindex; 129 struct list_head notifier; 130 struct list_head rx_ops; 131 struct list_head tx_ops; 132 unsigned long dropped_usr_msgs; 133 struct proc_dir_entry *bcm_proc_read; 134 char procname [32]; /* inode number in decimal with \0 */ 135 }; 136 137 static LIST_HEAD(bcm_notifier_list); 138 static DEFINE_SPINLOCK(bcm_notifier_lock); 139 static struct bcm_sock *bcm_busy_notifier; 140 141 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 142 { 143 return (struct bcm_sock *)sk; 144 } 145 146 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 147 { 148 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 149 } 150 151 /* check limitations for timeval provided by user */ 152 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 153 { 154 if ((msg_head->ival1.tv_sec < 0) || 155 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 156 (msg_head->ival1.tv_usec < 0) || 157 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 158 (msg_head->ival2.tv_sec < 0) || 159 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 160 (msg_head->ival2.tv_usec < 0) || 161 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 162 return true; 163 164 return false; 165 } 166 167 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 168 #define OPSIZ sizeof(struct bcm_op) 169 #define MHSIZ sizeof(struct bcm_msg_head) 170 171 /* 172 * procfs functions 173 */ 174 #if IS_ENABLED(CONFIG_PROC_FS) 175 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 176 { 177 struct net_device *dev; 178 179 if (!ifindex) 180 return "any"; 181 182 rcu_read_lock(); 183 dev = dev_get_by_index_rcu(net, ifindex); 184 if (dev) 185 strcpy(result, dev->name); 186 else 187 strcpy(result, "???"); 188 rcu_read_unlock(); 189 190 return result; 191 } 192 193 static int bcm_proc_show(struct seq_file *m, void *v) 194 { 195 char ifname[IFNAMSIZ]; 196 struct net *net = m->private; 197 struct sock *sk = (struct sock *)pde_data(m->file->f_inode); 198 struct bcm_sock *bo = bcm_sk(sk); 199 struct bcm_op *op; 200 201 seq_printf(m, ">>> socket %pK", sk->sk_socket); 202 seq_printf(m, " / sk %pK", sk); 203 seq_printf(m, " / bo %pK", bo); 204 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 205 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 206 seq_printf(m, " <<<\n"); 207 208 list_for_each_entry(op, &bo->rx_ops, list) { 209 210 unsigned long reduction; 211 212 /* print only active entries & prevent division by zero */ 213 if (!op->frames_abs) 214 continue; 215 216 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 217 bcm_proc_getifname(net, ifname, op->ifindex)); 218 219 if (op->flags & CAN_FD_FRAME) 220 seq_printf(m, "(%u)", op->nframes); 221 else 222 seq_printf(m, "[%u]", op->nframes); 223 224 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 225 226 if (op->kt_ival1) 227 seq_printf(m, "timeo=%lld ", 228 (long long)ktime_to_us(op->kt_ival1)); 229 230 if (op->kt_ival2) 231 seq_printf(m, "thr=%lld ", 232 (long long)ktime_to_us(op->kt_ival2)); 233 234 seq_printf(m, "# recv %ld (%ld) => reduction: ", 235 op->frames_filtered, op->frames_abs); 236 237 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 238 239 seq_printf(m, "%s%ld%%\n", 240 (reduction == 100) ? "near " : "", reduction); 241 } 242 243 list_for_each_entry(op, &bo->tx_ops, list) { 244 245 seq_printf(m, "tx_op: %03X %s ", op->can_id, 246 bcm_proc_getifname(net, ifname, op->ifindex)); 247 248 if (op->flags & CAN_FD_FRAME) 249 seq_printf(m, "(%u) ", op->nframes); 250 else 251 seq_printf(m, "[%u] ", op->nframes); 252 253 if (op->kt_ival1) 254 seq_printf(m, "t1=%lld ", 255 (long long)ktime_to_us(op->kt_ival1)); 256 257 if (op->kt_ival2) 258 seq_printf(m, "t2=%lld ", 259 (long long)ktime_to_us(op->kt_ival2)); 260 261 seq_printf(m, "# sent %ld\n", op->frames_abs); 262 } 263 seq_putc(m, '\n'); 264 return 0; 265 } 266 #endif /* CONFIG_PROC_FS */ 267 268 /* 269 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 270 * of the given bcm tx op 271 */ 272 static void bcm_can_tx(struct bcm_op *op) 273 { 274 struct sk_buff *skb; 275 struct net_device *dev; 276 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 277 278 /* no target device? => exit */ 279 if (!op->ifindex) 280 return; 281 282 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 283 if (!dev) { 284 /* RFC: should this bcm_op remove itself here? */ 285 return; 286 } 287 288 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 289 if (!skb) 290 goto out; 291 292 can_skb_reserve(skb); 293 can_skb_prv(skb)->ifindex = dev->ifindex; 294 can_skb_prv(skb)->skbcnt = 0; 295 296 skb_put_data(skb, cf, op->cfsiz); 297 298 /* send with loopback */ 299 skb->dev = dev; 300 can_skb_set_owner(skb, op->sk); 301 can_send(skb, 1); 302 303 /* update statistics */ 304 op->currframe++; 305 op->frames_abs++; 306 307 /* reached last frame? */ 308 if (op->currframe >= op->nframes) 309 op->currframe = 0; 310 out: 311 dev_put(dev); 312 } 313 314 /* 315 * bcm_send_to_user - send a BCM message to the userspace 316 * (consisting of bcm_msg_head + x CAN frames) 317 */ 318 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 319 struct canfd_frame *frames, int has_timestamp) 320 { 321 struct sk_buff *skb; 322 struct canfd_frame *firstframe; 323 struct sockaddr_can *addr; 324 struct sock *sk = op->sk; 325 unsigned int datalen = head->nframes * op->cfsiz; 326 int err; 327 328 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 329 if (!skb) 330 return; 331 332 skb_put_data(skb, head, sizeof(*head)); 333 334 if (head->nframes) { 335 /* CAN frames starting here */ 336 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 337 338 skb_put_data(skb, frames, datalen); 339 340 /* 341 * the BCM uses the flags-element of the canfd_frame 342 * structure for internal purposes. This is only 343 * relevant for updates that are generated by the 344 * BCM, where nframes is 1 345 */ 346 if (head->nframes == 1) 347 firstframe->flags &= BCM_CAN_FLAGS_MASK; 348 } 349 350 if (has_timestamp) { 351 /* restore rx timestamp */ 352 skb->tstamp = op->rx_stamp; 353 } 354 355 /* 356 * Put the datagram to the queue so that bcm_recvmsg() can 357 * get it from there. We need to pass the interface index to 358 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 359 * containing the interface index. 360 */ 361 362 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 363 addr = (struct sockaddr_can *)skb->cb; 364 memset(addr, 0, sizeof(*addr)); 365 addr->can_family = AF_CAN; 366 addr->can_ifindex = op->rx_ifindex; 367 368 err = sock_queue_rcv_skb(sk, skb); 369 if (err < 0) { 370 struct bcm_sock *bo = bcm_sk(sk); 371 372 kfree_skb(skb); 373 /* don't care about overflows in this statistic */ 374 bo->dropped_usr_msgs++; 375 } 376 } 377 378 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt) 379 { 380 ktime_t ival; 381 382 if (op->kt_ival1 && op->count) 383 ival = op->kt_ival1; 384 else if (op->kt_ival2) 385 ival = op->kt_ival2; 386 else 387 return false; 388 389 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival)); 390 return true; 391 } 392 393 static void bcm_tx_start_timer(struct bcm_op *op) 394 { 395 if (bcm_tx_set_expiry(op, &op->timer)) 396 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT); 397 } 398 399 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */ 400 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 401 { 402 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 403 struct bcm_msg_head msg_head; 404 405 if (op->kt_ival1 && (op->count > 0)) { 406 op->count--; 407 if (!op->count && (op->flags & TX_COUNTEVT)) { 408 409 /* create notification to user */ 410 memset(&msg_head, 0, sizeof(msg_head)); 411 msg_head.opcode = TX_EXPIRED; 412 msg_head.flags = op->flags; 413 msg_head.count = op->count; 414 msg_head.ival1 = op->ival1; 415 msg_head.ival2 = op->ival2; 416 msg_head.can_id = op->can_id; 417 msg_head.nframes = 0; 418 419 bcm_send_to_user(op, &msg_head, NULL, 0); 420 } 421 bcm_can_tx(op); 422 423 } else if (op->kt_ival2) { 424 bcm_can_tx(op); 425 } 426 427 return bcm_tx_set_expiry(op, &op->timer) ? 428 HRTIMER_RESTART : HRTIMER_NORESTART; 429 } 430 431 /* 432 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 433 */ 434 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 435 { 436 struct bcm_msg_head head; 437 438 /* update statistics */ 439 op->frames_filtered++; 440 441 /* prevent statistics overflow */ 442 if (op->frames_filtered > ULONG_MAX/100) 443 op->frames_filtered = op->frames_abs = 0; 444 445 /* this element is not throttled anymore */ 446 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 447 448 memset(&head, 0, sizeof(head)); 449 head.opcode = RX_CHANGED; 450 head.flags = op->flags; 451 head.count = op->count; 452 head.ival1 = op->ival1; 453 head.ival2 = op->ival2; 454 head.can_id = op->can_id; 455 head.nframes = 1; 456 457 bcm_send_to_user(op, &head, data, 1); 458 } 459 460 /* 461 * bcm_rx_update_and_send - process a detected relevant receive content change 462 * 1. update the last received data 463 * 2. send a notification to the user (if possible) 464 */ 465 static void bcm_rx_update_and_send(struct bcm_op *op, 466 struct canfd_frame *lastdata, 467 const struct canfd_frame *rxdata) 468 { 469 memcpy(lastdata, rxdata, op->cfsiz); 470 471 /* mark as used and throttled by default */ 472 lastdata->flags |= (RX_RECV|RX_THR); 473 474 /* throttling mode inactive ? */ 475 if (!op->kt_ival2) { 476 /* send RX_CHANGED to the user immediately */ 477 bcm_rx_changed(op, lastdata); 478 return; 479 } 480 481 /* with active throttling timer we are just done here */ 482 if (hrtimer_active(&op->thrtimer)) 483 return; 484 485 /* first reception with enabled throttling mode */ 486 if (!op->kt_lastmsg) 487 goto rx_changed_settime; 488 489 /* got a second frame inside a potential throttle period? */ 490 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 491 ktime_to_us(op->kt_ival2)) { 492 /* do not send the saved data - only start throttle timer */ 493 hrtimer_start(&op->thrtimer, 494 ktime_add(op->kt_lastmsg, op->kt_ival2), 495 HRTIMER_MODE_ABS_SOFT); 496 return; 497 } 498 499 /* the gap was that big, that throttling was not needed here */ 500 rx_changed_settime: 501 bcm_rx_changed(op, lastdata); 502 op->kt_lastmsg = ktime_get(); 503 } 504 505 /* 506 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 507 * received data stored in op->last_frames[] 508 */ 509 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 510 const struct canfd_frame *rxdata) 511 { 512 struct canfd_frame *cf = op->frames + op->cfsiz * index; 513 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 514 int i; 515 516 /* 517 * no one uses the MSBs of flags for comparison, 518 * so we use it here to detect the first time of reception 519 */ 520 521 if (!(lcf->flags & RX_RECV)) { 522 /* received data for the first time => send update to user */ 523 bcm_rx_update_and_send(op, lcf, rxdata); 524 return; 525 } 526 527 /* do a real check in CAN frame data section */ 528 for (i = 0; i < rxdata->len; i += 8) { 529 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 530 (get_u64(cf, i) & get_u64(lcf, i))) { 531 bcm_rx_update_and_send(op, lcf, rxdata); 532 return; 533 } 534 } 535 536 if (op->flags & RX_CHECK_DLC) { 537 /* do a real check in CAN frame length */ 538 if (rxdata->len != lcf->len) { 539 bcm_rx_update_and_send(op, lcf, rxdata); 540 return; 541 } 542 } 543 } 544 545 /* 546 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 547 */ 548 static void bcm_rx_starttimer(struct bcm_op *op) 549 { 550 if (op->flags & RX_NO_AUTOTIMER) 551 return; 552 553 if (op->kt_ival1) 554 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT); 555 } 556 557 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */ 558 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 559 { 560 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 561 struct bcm_msg_head msg_head; 562 563 /* if user wants to be informed, when cyclic CAN-Messages come back */ 564 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 565 /* clear received CAN frames to indicate 'nothing received' */ 566 memset(op->last_frames, 0, op->nframes * op->cfsiz); 567 } 568 569 /* create notification to user */ 570 memset(&msg_head, 0, sizeof(msg_head)); 571 msg_head.opcode = RX_TIMEOUT; 572 msg_head.flags = op->flags; 573 msg_head.count = op->count; 574 msg_head.ival1 = op->ival1; 575 msg_head.ival2 = op->ival2; 576 msg_head.can_id = op->can_id; 577 msg_head.nframes = 0; 578 579 bcm_send_to_user(op, &msg_head, NULL, 0); 580 581 return HRTIMER_NORESTART; 582 } 583 584 /* 585 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 586 */ 587 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index) 588 { 589 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 590 591 if ((op->last_frames) && (lcf->flags & RX_THR)) { 592 bcm_rx_changed(op, lcf); 593 return 1; 594 } 595 return 0; 596 } 597 598 /* 599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 600 */ 601 static int bcm_rx_thr_flush(struct bcm_op *op) 602 { 603 int updated = 0; 604 605 if (op->nframes > 1) { 606 unsigned int i; 607 608 /* for MUX filter we start at index 1 */ 609 for (i = 1; i < op->nframes; i++) 610 updated += bcm_rx_do_flush(op, i); 611 612 } else { 613 /* for RX_FILTER_ID and simple filter */ 614 updated += bcm_rx_do_flush(op, 0); 615 } 616 617 return updated; 618 } 619 620 /* 621 * bcm_rx_thr_handler - the time for blocked content updates is over now: 622 * Check for throttled data and send it to the userspace 623 */ 624 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 625 { 626 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 627 628 if (bcm_rx_thr_flush(op)) { 629 hrtimer_forward_now(hrtimer, op->kt_ival2); 630 return HRTIMER_RESTART; 631 } else { 632 /* rearm throttle handling */ 633 op->kt_lastmsg = 0; 634 return HRTIMER_NORESTART; 635 } 636 } 637 638 /* 639 * bcm_rx_handler - handle a CAN frame reception 640 */ 641 static void bcm_rx_handler(struct sk_buff *skb, void *data) 642 { 643 struct bcm_op *op = (struct bcm_op *)data; 644 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 645 unsigned int i; 646 647 if (op->can_id != rxframe->can_id) 648 return; 649 650 /* make sure to handle the correct frame type (CAN / CAN FD) */ 651 if (op->flags & CAN_FD_FRAME) { 652 if (!can_is_canfd_skb(skb)) 653 return; 654 } else { 655 if (!can_is_can_skb(skb)) 656 return; 657 } 658 659 /* disable timeout */ 660 hrtimer_cancel(&op->timer); 661 662 /* save rx timestamp */ 663 op->rx_stamp = skb->tstamp; 664 /* save originator for recvfrom() */ 665 op->rx_ifindex = skb->dev->ifindex; 666 /* update statistics */ 667 op->frames_abs++; 668 669 if (op->flags & RX_RTR_FRAME) { 670 /* send reply for RTR-request (placed in op->frames[0]) */ 671 bcm_can_tx(op); 672 return; 673 } 674 675 if (op->flags & RX_FILTER_ID) { 676 /* the easiest case */ 677 bcm_rx_update_and_send(op, op->last_frames, rxframe); 678 goto rx_starttimer; 679 } 680 681 if (op->nframes == 1) { 682 /* simple compare with index 0 */ 683 bcm_rx_cmp_to_index(op, 0, rxframe); 684 goto rx_starttimer; 685 } 686 687 if (op->nframes > 1) { 688 /* 689 * multiplex compare 690 * 691 * find the first multiplex mask that fits. 692 * Remark: The MUX-mask is stored in index 0 - but only the 693 * first 64 bits of the frame data[] are relevant (CAN FD) 694 */ 695 696 for (i = 1; i < op->nframes; i++) { 697 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 698 (get_u64(op->frames, 0) & 699 get_u64(op->frames + op->cfsiz * i, 0))) { 700 bcm_rx_cmp_to_index(op, i, rxframe); 701 break; 702 } 703 } 704 } 705 706 rx_starttimer: 707 bcm_rx_starttimer(op); 708 } 709 710 /* 711 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 712 */ 713 static struct bcm_op *bcm_find_op(struct list_head *ops, 714 struct bcm_msg_head *mh, int ifindex) 715 { 716 struct bcm_op *op; 717 718 list_for_each_entry(op, ops, list) { 719 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 720 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 721 return op; 722 } 723 724 return NULL; 725 } 726 727 static void bcm_free_op_rcu(struct rcu_head *rcu_head) 728 { 729 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu); 730 731 if ((op->frames) && (op->frames != &op->sframe)) 732 kfree(op->frames); 733 734 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 735 kfree(op->last_frames); 736 737 kfree(op); 738 } 739 740 static void bcm_remove_op(struct bcm_op *op) 741 { 742 hrtimer_cancel(&op->timer); 743 hrtimer_cancel(&op->thrtimer); 744 745 call_rcu(&op->rcu, bcm_free_op_rcu); 746 } 747 748 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 749 { 750 if (op->rx_reg_dev == dev) { 751 can_rx_unregister(dev_net(dev), dev, op->can_id, 752 REGMASK(op->can_id), bcm_rx_handler, op); 753 754 /* mark as removed subscription */ 755 op->rx_reg_dev = NULL; 756 } else 757 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 758 "mismatch %p %p\n", op->rx_reg_dev, dev); 759 } 760 761 /* 762 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 763 */ 764 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 765 int ifindex) 766 { 767 struct bcm_op *op, *n; 768 769 list_for_each_entry_safe(op, n, ops, list) { 770 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 771 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 772 773 /* disable automatic timer on frame reception */ 774 op->flags |= RX_NO_AUTOTIMER; 775 776 /* 777 * Don't care if we're bound or not (due to netdev 778 * problems) can_rx_unregister() is always a save 779 * thing to do here. 780 */ 781 if (op->ifindex) { 782 /* 783 * Only remove subscriptions that had not 784 * been removed due to NETDEV_UNREGISTER 785 * in bcm_notifier() 786 */ 787 if (op->rx_reg_dev) { 788 struct net_device *dev; 789 790 dev = dev_get_by_index(sock_net(op->sk), 791 op->ifindex); 792 if (dev) { 793 bcm_rx_unreg(dev, op); 794 dev_put(dev); 795 } 796 } 797 } else 798 can_rx_unregister(sock_net(op->sk), NULL, 799 op->can_id, 800 REGMASK(op->can_id), 801 bcm_rx_handler, op); 802 803 list_del(&op->list); 804 bcm_remove_op(op); 805 return 1; /* done */ 806 } 807 } 808 809 return 0; /* not found */ 810 } 811 812 /* 813 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 814 */ 815 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 816 int ifindex) 817 { 818 struct bcm_op *op, *n; 819 820 list_for_each_entry_safe(op, n, ops, list) { 821 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 822 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 823 list_del(&op->list); 824 bcm_remove_op(op); 825 return 1; /* done */ 826 } 827 } 828 829 return 0; /* not found */ 830 } 831 832 /* 833 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 834 */ 835 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 836 int ifindex) 837 { 838 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 839 840 if (!op) 841 return -EINVAL; 842 843 /* put current values into msg_head */ 844 msg_head->flags = op->flags; 845 msg_head->count = op->count; 846 msg_head->ival1 = op->ival1; 847 msg_head->ival2 = op->ival2; 848 msg_head->nframes = op->nframes; 849 850 bcm_send_to_user(op, msg_head, op->frames, 0); 851 852 return MHSIZ; 853 } 854 855 /* 856 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 857 */ 858 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 859 int ifindex, struct sock *sk) 860 { 861 struct bcm_sock *bo = bcm_sk(sk); 862 struct bcm_op *op; 863 struct canfd_frame *cf; 864 unsigned int i; 865 int err; 866 867 /* we need a real device to send frames */ 868 if (!ifindex) 869 return -ENODEV; 870 871 /* check nframes boundaries - we need at least one CAN frame */ 872 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 873 return -EINVAL; 874 875 /* check timeval limitations */ 876 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 877 return -EINVAL; 878 879 /* check the given can_id */ 880 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 881 if (op) { 882 /* update existing BCM operation */ 883 884 /* 885 * Do we need more space for the CAN frames than currently 886 * allocated? -> This is a _really_ unusual use-case and 887 * therefore (complexity / locking) it is not supported. 888 */ 889 if (msg_head->nframes > op->nframes) 890 return -E2BIG; 891 892 /* update CAN frames content */ 893 for (i = 0; i < msg_head->nframes; i++) { 894 895 cf = op->frames + op->cfsiz * i; 896 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 897 898 if (op->flags & CAN_FD_FRAME) { 899 if (cf->len > 64) 900 err = -EINVAL; 901 } else { 902 if (cf->len > 8) 903 err = -EINVAL; 904 } 905 906 if (err < 0) 907 return err; 908 909 if (msg_head->flags & TX_CP_CAN_ID) { 910 /* copy can_id into frame */ 911 cf->can_id = msg_head->can_id; 912 } 913 } 914 op->flags = msg_head->flags; 915 916 } else { 917 /* insert new BCM operation for the given can_id */ 918 919 op = kzalloc(OPSIZ, GFP_KERNEL); 920 if (!op) 921 return -ENOMEM; 922 923 op->can_id = msg_head->can_id; 924 op->cfsiz = CFSIZ(msg_head->flags); 925 op->flags = msg_head->flags; 926 927 /* create array for CAN frames and copy the data */ 928 if (msg_head->nframes > 1) { 929 op->frames = kmalloc_array(msg_head->nframes, 930 op->cfsiz, 931 GFP_KERNEL); 932 if (!op->frames) { 933 kfree(op); 934 return -ENOMEM; 935 } 936 } else 937 op->frames = &op->sframe; 938 939 for (i = 0; i < msg_head->nframes; i++) { 940 941 cf = op->frames + op->cfsiz * i; 942 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 943 944 if (op->flags & CAN_FD_FRAME) { 945 if (cf->len > 64) 946 err = -EINVAL; 947 } else { 948 if (cf->len > 8) 949 err = -EINVAL; 950 } 951 952 if (err < 0) { 953 if (op->frames != &op->sframe) 954 kfree(op->frames); 955 kfree(op); 956 return err; 957 } 958 959 if (msg_head->flags & TX_CP_CAN_ID) { 960 /* copy can_id into frame */ 961 cf->can_id = msg_head->can_id; 962 } 963 } 964 965 /* tx_ops never compare with previous received messages */ 966 op->last_frames = NULL; 967 968 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 969 op->sk = sk; 970 op->ifindex = ifindex; 971 972 /* initialize uninitialized (kzalloc) structure */ 973 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 974 HRTIMER_MODE_REL_SOFT); 975 op->timer.function = bcm_tx_timeout_handler; 976 977 /* currently unused in tx_ops */ 978 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 979 HRTIMER_MODE_REL_SOFT); 980 981 /* add this bcm_op to the list of the tx_ops */ 982 list_add(&op->list, &bo->tx_ops); 983 984 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 985 986 if (op->nframes != msg_head->nframes) { 987 op->nframes = msg_head->nframes; 988 /* start multiple frame transmission with index 0 */ 989 op->currframe = 0; 990 } 991 992 /* check flags */ 993 994 if (op->flags & TX_RESET_MULTI_IDX) { 995 /* start multiple frame transmission with index 0 */ 996 op->currframe = 0; 997 } 998 999 if (op->flags & SETTIMER) { 1000 /* set timer values */ 1001 op->count = msg_head->count; 1002 op->ival1 = msg_head->ival1; 1003 op->ival2 = msg_head->ival2; 1004 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1005 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1006 1007 /* disable an active timer due to zero values? */ 1008 if (!op->kt_ival1 && !op->kt_ival2) 1009 hrtimer_cancel(&op->timer); 1010 } 1011 1012 if (op->flags & STARTTIMER) { 1013 hrtimer_cancel(&op->timer); 1014 /* spec: send CAN frame when starting timer */ 1015 op->flags |= TX_ANNOUNCE; 1016 } 1017 1018 if (op->flags & TX_ANNOUNCE) { 1019 bcm_can_tx(op); 1020 if (op->count) 1021 op->count--; 1022 } 1023 1024 if (op->flags & STARTTIMER) 1025 bcm_tx_start_timer(op); 1026 1027 return msg_head->nframes * op->cfsiz + MHSIZ; 1028 } 1029 1030 /* 1031 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1032 */ 1033 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1034 int ifindex, struct sock *sk) 1035 { 1036 struct bcm_sock *bo = bcm_sk(sk); 1037 struct bcm_op *op; 1038 int do_rx_register; 1039 int err = 0; 1040 1041 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1042 /* be robust against wrong usage ... */ 1043 msg_head->flags |= RX_FILTER_ID; 1044 /* ignore trailing garbage */ 1045 msg_head->nframes = 0; 1046 } 1047 1048 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1049 if (msg_head->nframes > MAX_NFRAMES + 1) 1050 return -EINVAL; 1051 1052 if ((msg_head->flags & RX_RTR_FRAME) && 1053 ((msg_head->nframes != 1) || 1054 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1055 return -EINVAL; 1056 1057 /* check timeval limitations */ 1058 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1059 return -EINVAL; 1060 1061 /* check the given can_id */ 1062 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1063 if (op) { 1064 /* update existing BCM operation */ 1065 1066 /* 1067 * Do we need more space for the CAN frames than currently 1068 * allocated? -> This is a _really_ unusual use-case and 1069 * therefore (complexity / locking) it is not supported. 1070 */ 1071 if (msg_head->nframes > op->nframes) 1072 return -E2BIG; 1073 1074 if (msg_head->nframes) { 1075 /* update CAN frames content */ 1076 err = memcpy_from_msg(op->frames, msg, 1077 msg_head->nframes * op->cfsiz); 1078 if (err < 0) 1079 return err; 1080 1081 /* clear last_frames to indicate 'nothing received' */ 1082 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1083 } 1084 1085 op->nframes = msg_head->nframes; 1086 op->flags = msg_head->flags; 1087 1088 /* Only an update -> do not call can_rx_register() */ 1089 do_rx_register = 0; 1090 1091 } else { 1092 /* insert new BCM operation for the given can_id */ 1093 op = kzalloc(OPSIZ, GFP_KERNEL); 1094 if (!op) 1095 return -ENOMEM; 1096 1097 op->can_id = msg_head->can_id; 1098 op->nframes = msg_head->nframes; 1099 op->cfsiz = CFSIZ(msg_head->flags); 1100 op->flags = msg_head->flags; 1101 1102 if (msg_head->nframes > 1) { 1103 /* create array for CAN frames and copy the data */ 1104 op->frames = kmalloc_array(msg_head->nframes, 1105 op->cfsiz, 1106 GFP_KERNEL); 1107 if (!op->frames) { 1108 kfree(op); 1109 return -ENOMEM; 1110 } 1111 1112 /* create and init array for received CAN frames */ 1113 op->last_frames = kcalloc(msg_head->nframes, 1114 op->cfsiz, 1115 GFP_KERNEL); 1116 if (!op->last_frames) { 1117 kfree(op->frames); 1118 kfree(op); 1119 return -ENOMEM; 1120 } 1121 1122 } else { 1123 op->frames = &op->sframe; 1124 op->last_frames = &op->last_sframe; 1125 } 1126 1127 if (msg_head->nframes) { 1128 err = memcpy_from_msg(op->frames, msg, 1129 msg_head->nframes * op->cfsiz); 1130 if (err < 0) { 1131 if (op->frames != &op->sframe) 1132 kfree(op->frames); 1133 if (op->last_frames != &op->last_sframe) 1134 kfree(op->last_frames); 1135 kfree(op); 1136 return err; 1137 } 1138 } 1139 1140 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1141 op->sk = sk; 1142 op->ifindex = ifindex; 1143 1144 /* ifindex for timeout events w/o previous frame reception */ 1145 op->rx_ifindex = ifindex; 1146 1147 /* initialize uninitialized (kzalloc) structure */ 1148 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 1149 HRTIMER_MODE_REL_SOFT); 1150 op->timer.function = bcm_rx_timeout_handler; 1151 1152 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 1153 HRTIMER_MODE_REL_SOFT); 1154 op->thrtimer.function = bcm_rx_thr_handler; 1155 1156 /* add this bcm_op to the list of the rx_ops */ 1157 list_add(&op->list, &bo->rx_ops); 1158 1159 /* call can_rx_register() */ 1160 do_rx_register = 1; 1161 1162 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1163 1164 /* check flags */ 1165 1166 if (op->flags & RX_RTR_FRAME) { 1167 struct canfd_frame *frame0 = op->frames; 1168 1169 /* no timers in RTR-mode */ 1170 hrtimer_cancel(&op->thrtimer); 1171 hrtimer_cancel(&op->timer); 1172 1173 /* 1174 * funny feature in RX(!)_SETUP only for RTR-mode: 1175 * copy can_id into frame BUT without RTR-flag to 1176 * prevent a full-load-loopback-test ... ;-] 1177 */ 1178 if ((op->flags & TX_CP_CAN_ID) || 1179 (frame0->can_id == op->can_id)) 1180 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1181 1182 } else { 1183 if (op->flags & SETTIMER) { 1184 1185 /* set timer value */ 1186 op->ival1 = msg_head->ival1; 1187 op->ival2 = msg_head->ival2; 1188 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1189 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1190 1191 /* disable an active timer due to zero value? */ 1192 if (!op->kt_ival1) 1193 hrtimer_cancel(&op->timer); 1194 1195 /* 1196 * In any case cancel the throttle timer, flush 1197 * potentially blocked msgs and reset throttle handling 1198 */ 1199 op->kt_lastmsg = 0; 1200 hrtimer_cancel(&op->thrtimer); 1201 bcm_rx_thr_flush(op); 1202 } 1203 1204 if ((op->flags & STARTTIMER) && op->kt_ival1) 1205 hrtimer_start(&op->timer, op->kt_ival1, 1206 HRTIMER_MODE_REL_SOFT); 1207 } 1208 1209 /* now we can register for can_ids, if we added a new bcm_op */ 1210 if (do_rx_register) { 1211 if (ifindex) { 1212 struct net_device *dev; 1213 1214 dev = dev_get_by_index(sock_net(sk), ifindex); 1215 if (dev) { 1216 err = can_rx_register(sock_net(sk), dev, 1217 op->can_id, 1218 REGMASK(op->can_id), 1219 bcm_rx_handler, op, 1220 "bcm", sk); 1221 1222 op->rx_reg_dev = dev; 1223 dev_put(dev); 1224 } 1225 1226 } else 1227 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1228 REGMASK(op->can_id), 1229 bcm_rx_handler, op, "bcm", sk); 1230 if (err) { 1231 /* this bcm rx op is broken -> remove it */ 1232 list_del(&op->list); 1233 bcm_remove_op(op); 1234 return err; 1235 } 1236 } 1237 1238 return msg_head->nframes * op->cfsiz + MHSIZ; 1239 } 1240 1241 /* 1242 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1243 */ 1244 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1245 int cfsiz) 1246 { 1247 struct sk_buff *skb; 1248 struct net_device *dev; 1249 int err; 1250 1251 /* we need a real device to send frames */ 1252 if (!ifindex) 1253 return -ENODEV; 1254 1255 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1256 if (!skb) 1257 return -ENOMEM; 1258 1259 can_skb_reserve(skb); 1260 1261 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1262 if (err < 0) { 1263 kfree_skb(skb); 1264 return err; 1265 } 1266 1267 dev = dev_get_by_index(sock_net(sk), ifindex); 1268 if (!dev) { 1269 kfree_skb(skb); 1270 return -ENODEV; 1271 } 1272 1273 can_skb_prv(skb)->ifindex = dev->ifindex; 1274 can_skb_prv(skb)->skbcnt = 0; 1275 skb->dev = dev; 1276 can_skb_set_owner(skb, sk); 1277 err = can_send(skb, 1); /* send with loopback */ 1278 dev_put(dev); 1279 1280 if (err) 1281 return err; 1282 1283 return cfsiz + MHSIZ; 1284 } 1285 1286 /* 1287 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1288 */ 1289 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1290 { 1291 struct sock *sk = sock->sk; 1292 struct bcm_sock *bo = bcm_sk(sk); 1293 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1294 struct bcm_msg_head msg_head; 1295 int cfsiz; 1296 int ret; /* read bytes or error codes as return value */ 1297 1298 if (!bo->bound) 1299 return -ENOTCONN; 1300 1301 /* check for valid message length from userspace */ 1302 if (size < MHSIZ) 1303 return -EINVAL; 1304 1305 /* read message head information */ 1306 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1307 if (ret < 0) 1308 return ret; 1309 1310 cfsiz = CFSIZ(msg_head.flags); 1311 if ((size - MHSIZ) % cfsiz) 1312 return -EINVAL; 1313 1314 /* check for alternative ifindex for this bcm_op */ 1315 1316 if (!ifindex && msg->msg_name) { 1317 /* no bound device as default => check msg_name */ 1318 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1319 1320 if (msg->msg_namelen < BCM_MIN_NAMELEN) 1321 return -EINVAL; 1322 1323 if (addr->can_family != AF_CAN) 1324 return -EINVAL; 1325 1326 /* ifindex from sendto() */ 1327 ifindex = addr->can_ifindex; 1328 1329 if (ifindex) { 1330 struct net_device *dev; 1331 1332 dev = dev_get_by_index(sock_net(sk), ifindex); 1333 if (!dev) 1334 return -ENODEV; 1335 1336 if (dev->type != ARPHRD_CAN) { 1337 dev_put(dev); 1338 return -ENODEV; 1339 } 1340 1341 dev_put(dev); 1342 } 1343 } 1344 1345 lock_sock(sk); 1346 1347 switch (msg_head.opcode) { 1348 1349 case TX_SETUP: 1350 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1351 break; 1352 1353 case RX_SETUP: 1354 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1355 break; 1356 1357 case TX_DELETE: 1358 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1359 ret = MHSIZ; 1360 else 1361 ret = -EINVAL; 1362 break; 1363 1364 case RX_DELETE: 1365 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1366 ret = MHSIZ; 1367 else 1368 ret = -EINVAL; 1369 break; 1370 1371 case TX_READ: 1372 /* reuse msg_head for the reply to TX_READ */ 1373 msg_head.opcode = TX_STATUS; 1374 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1375 break; 1376 1377 case RX_READ: 1378 /* reuse msg_head for the reply to RX_READ */ 1379 msg_head.opcode = RX_STATUS; 1380 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1381 break; 1382 1383 case TX_SEND: 1384 /* we need exactly one CAN frame behind the msg head */ 1385 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1386 ret = -EINVAL; 1387 else 1388 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1389 break; 1390 1391 default: 1392 ret = -EINVAL; 1393 break; 1394 } 1395 1396 release_sock(sk); 1397 1398 return ret; 1399 } 1400 1401 /* 1402 * notification handler for netdevice status changes 1403 */ 1404 static void bcm_notify(struct bcm_sock *bo, unsigned long msg, 1405 struct net_device *dev) 1406 { 1407 struct sock *sk = &bo->sk; 1408 struct bcm_op *op; 1409 int notify_enodev = 0; 1410 1411 if (!net_eq(dev_net(dev), sock_net(sk))) 1412 return; 1413 1414 switch (msg) { 1415 1416 case NETDEV_UNREGISTER: 1417 lock_sock(sk); 1418 1419 /* remove device specific receive entries */ 1420 list_for_each_entry(op, &bo->rx_ops, list) 1421 if (op->rx_reg_dev == dev) 1422 bcm_rx_unreg(dev, op); 1423 1424 /* remove device reference, if this is our bound device */ 1425 if (bo->bound && bo->ifindex == dev->ifindex) { 1426 bo->bound = 0; 1427 bo->ifindex = 0; 1428 notify_enodev = 1; 1429 } 1430 1431 release_sock(sk); 1432 1433 if (notify_enodev) { 1434 sk->sk_err = ENODEV; 1435 if (!sock_flag(sk, SOCK_DEAD)) 1436 sk_error_report(sk); 1437 } 1438 break; 1439 1440 case NETDEV_DOWN: 1441 if (bo->bound && bo->ifindex == dev->ifindex) { 1442 sk->sk_err = ENETDOWN; 1443 if (!sock_flag(sk, SOCK_DEAD)) 1444 sk_error_report(sk); 1445 } 1446 } 1447 } 1448 1449 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1450 void *ptr) 1451 { 1452 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1453 1454 if (dev->type != ARPHRD_CAN) 1455 return NOTIFY_DONE; 1456 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 1457 return NOTIFY_DONE; 1458 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */ 1459 return NOTIFY_DONE; 1460 1461 spin_lock(&bcm_notifier_lock); 1462 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) { 1463 spin_unlock(&bcm_notifier_lock); 1464 bcm_notify(bcm_busy_notifier, msg, dev); 1465 spin_lock(&bcm_notifier_lock); 1466 } 1467 bcm_busy_notifier = NULL; 1468 spin_unlock(&bcm_notifier_lock); 1469 return NOTIFY_DONE; 1470 } 1471 1472 /* 1473 * initial settings for all BCM sockets to be set at socket creation time 1474 */ 1475 static int bcm_init(struct sock *sk) 1476 { 1477 struct bcm_sock *bo = bcm_sk(sk); 1478 1479 bo->bound = 0; 1480 bo->ifindex = 0; 1481 bo->dropped_usr_msgs = 0; 1482 bo->bcm_proc_read = NULL; 1483 1484 INIT_LIST_HEAD(&bo->tx_ops); 1485 INIT_LIST_HEAD(&bo->rx_ops); 1486 1487 /* set notifier */ 1488 spin_lock(&bcm_notifier_lock); 1489 list_add_tail(&bo->notifier, &bcm_notifier_list); 1490 spin_unlock(&bcm_notifier_lock); 1491 1492 return 0; 1493 } 1494 1495 /* 1496 * standard socket functions 1497 */ 1498 static int bcm_release(struct socket *sock) 1499 { 1500 struct sock *sk = sock->sk; 1501 struct net *net; 1502 struct bcm_sock *bo; 1503 struct bcm_op *op, *next; 1504 1505 if (!sk) 1506 return 0; 1507 1508 net = sock_net(sk); 1509 bo = bcm_sk(sk); 1510 1511 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1512 1513 spin_lock(&bcm_notifier_lock); 1514 while (bcm_busy_notifier == bo) { 1515 spin_unlock(&bcm_notifier_lock); 1516 schedule_timeout_uninterruptible(1); 1517 spin_lock(&bcm_notifier_lock); 1518 } 1519 list_del(&bo->notifier); 1520 spin_unlock(&bcm_notifier_lock); 1521 1522 lock_sock(sk); 1523 1524 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1525 bcm_remove_op(op); 1526 1527 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1528 /* 1529 * Don't care if we're bound or not (due to netdev problems) 1530 * can_rx_unregister() is always a save thing to do here. 1531 */ 1532 if (op->ifindex) { 1533 /* 1534 * Only remove subscriptions that had not 1535 * been removed due to NETDEV_UNREGISTER 1536 * in bcm_notifier() 1537 */ 1538 if (op->rx_reg_dev) { 1539 struct net_device *dev; 1540 1541 dev = dev_get_by_index(net, op->ifindex); 1542 if (dev) { 1543 bcm_rx_unreg(dev, op); 1544 dev_put(dev); 1545 } 1546 } 1547 } else 1548 can_rx_unregister(net, NULL, op->can_id, 1549 REGMASK(op->can_id), 1550 bcm_rx_handler, op); 1551 1552 } 1553 1554 synchronize_rcu(); 1555 1556 list_for_each_entry_safe(op, next, &bo->rx_ops, list) 1557 bcm_remove_op(op); 1558 1559 #if IS_ENABLED(CONFIG_PROC_FS) 1560 /* remove procfs entry */ 1561 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1562 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1563 #endif /* CONFIG_PROC_FS */ 1564 1565 /* remove device reference */ 1566 if (bo->bound) { 1567 bo->bound = 0; 1568 bo->ifindex = 0; 1569 } 1570 1571 sock_orphan(sk); 1572 sock->sk = NULL; 1573 1574 release_sock(sk); 1575 sock_put(sk); 1576 1577 return 0; 1578 } 1579 1580 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1581 int flags) 1582 { 1583 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1584 struct sock *sk = sock->sk; 1585 struct bcm_sock *bo = bcm_sk(sk); 1586 struct net *net = sock_net(sk); 1587 int ret = 0; 1588 1589 if (len < BCM_MIN_NAMELEN) 1590 return -EINVAL; 1591 1592 lock_sock(sk); 1593 1594 if (bo->bound) { 1595 ret = -EISCONN; 1596 goto fail; 1597 } 1598 1599 /* bind a device to this socket */ 1600 if (addr->can_ifindex) { 1601 struct net_device *dev; 1602 1603 dev = dev_get_by_index(net, addr->can_ifindex); 1604 if (!dev) { 1605 ret = -ENODEV; 1606 goto fail; 1607 } 1608 if (dev->type != ARPHRD_CAN) { 1609 dev_put(dev); 1610 ret = -ENODEV; 1611 goto fail; 1612 } 1613 1614 bo->ifindex = dev->ifindex; 1615 dev_put(dev); 1616 1617 } else { 1618 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1619 bo->ifindex = 0; 1620 } 1621 1622 #if IS_ENABLED(CONFIG_PROC_FS) 1623 if (net->can.bcmproc_dir) { 1624 /* unique socket address as filename */ 1625 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1626 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1627 net->can.bcmproc_dir, 1628 bcm_proc_show, sk); 1629 if (!bo->bcm_proc_read) { 1630 ret = -ENOMEM; 1631 goto fail; 1632 } 1633 } 1634 #endif /* CONFIG_PROC_FS */ 1635 1636 bo->bound = 1; 1637 1638 fail: 1639 release_sock(sk); 1640 1641 return ret; 1642 } 1643 1644 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1645 int flags) 1646 { 1647 struct sock *sk = sock->sk; 1648 struct sk_buff *skb; 1649 int error = 0; 1650 int err; 1651 1652 skb = skb_recv_datagram(sk, flags, &error); 1653 if (!skb) 1654 return error; 1655 1656 if (skb->len < size) 1657 size = skb->len; 1658 1659 err = memcpy_to_msg(msg, skb->data, size); 1660 if (err < 0) { 1661 skb_free_datagram(sk, skb); 1662 return err; 1663 } 1664 1665 sock_recv_cmsgs(msg, sk, skb); 1666 1667 if (msg->msg_name) { 1668 __sockaddr_check_size(BCM_MIN_NAMELEN); 1669 msg->msg_namelen = BCM_MIN_NAMELEN; 1670 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1671 } 1672 1673 skb_free_datagram(sk, skb); 1674 1675 return size; 1676 } 1677 1678 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1679 unsigned long arg) 1680 { 1681 /* no ioctls for socket layer -> hand it down to NIC layer */ 1682 return -ENOIOCTLCMD; 1683 } 1684 1685 static const struct proto_ops bcm_ops = { 1686 .family = PF_CAN, 1687 .release = bcm_release, 1688 .bind = sock_no_bind, 1689 .connect = bcm_connect, 1690 .socketpair = sock_no_socketpair, 1691 .accept = sock_no_accept, 1692 .getname = sock_no_getname, 1693 .poll = datagram_poll, 1694 .ioctl = bcm_sock_no_ioctlcmd, 1695 .gettstamp = sock_gettstamp, 1696 .listen = sock_no_listen, 1697 .shutdown = sock_no_shutdown, 1698 .sendmsg = bcm_sendmsg, 1699 .recvmsg = bcm_recvmsg, 1700 .mmap = sock_no_mmap, 1701 .sendpage = sock_no_sendpage, 1702 }; 1703 1704 static struct proto bcm_proto __read_mostly = { 1705 .name = "CAN_BCM", 1706 .owner = THIS_MODULE, 1707 .obj_size = sizeof(struct bcm_sock), 1708 .init = bcm_init, 1709 }; 1710 1711 static const struct can_proto bcm_can_proto = { 1712 .type = SOCK_DGRAM, 1713 .protocol = CAN_BCM, 1714 .ops = &bcm_ops, 1715 .prot = &bcm_proto, 1716 }; 1717 1718 static int canbcm_pernet_init(struct net *net) 1719 { 1720 #if IS_ENABLED(CONFIG_PROC_FS) 1721 /* create /proc/net/can-bcm directory */ 1722 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1723 #endif /* CONFIG_PROC_FS */ 1724 1725 return 0; 1726 } 1727 1728 static void canbcm_pernet_exit(struct net *net) 1729 { 1730 #if IS_ENABLED(CONFIG_PROC_FS) 1731 /* remove /proc/net/can-bcm directory */ 1732 if (net->can.bcmproc_dir) 1733 remove_proc_entry("can-bcm", net->proc_net); 1734 #endif /* CONFIG_PROC_FS */ 1735 } 1736 1737 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1738 .init = canbcm_pernet_init, 1739 .exit = canbcm_pernet_exit, 1740 }; 1741 1742 static struct notifier_block canbcm_notifier = { 1743 .notifier_call = bcm_notifier 1744 }; 1745 1746 static int __init bcm_module_init(void) 1747 { 1748 int err; 1749 1750 pr_info("can: broadcast manager protocol\n"); 1751 1752 err = can_proto_register(&bcm_can_proto); 1753 if (err < 0) { 1754 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1755 return err; 1756 } 1757 1758 register_pernet_subsys(&canbcm_pernet_ops); 1759 register_netdevice_notifier(&canbcm_notifier); 1760 return 0; 1761 } 1762 1763 static void __exit bcm_module_exit(void) 1764 { 1765 can_proto_unregister(&bcm_can_proto); 1766 unregister_netdevice_notifier(&canbcm_notifier); 1767 unregister_pernet_subsys(&canbcm_pernet_ops); 1768 } 1769 1770 module_init(bcm_module_init); 1771 module_exit(bcm_module_exit); 1772