1 /* 2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content 3 * 4 * Copyright (c) 2002-2017 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/interrupt.h> 45 #include <linux/hrtimer.h> 46 #include <linux/list.h> 47 #include <linux/proc_fs.h> 48 #include <linux/seq_file.h> 49 #include <linux/uio.h> 50 #include <linux/net.h> 51 #include <linux/netdevice.h> 52 #include <linux/socket.h> 53 #include <linux/if_arp.h> 54 #include <linux/skbuff.h> 55 #include <linux/can.h> 56 #include <linux/can/core.h> 57 #include <linux/can/skb.h> 58 #include <linux/can/bcm.h> 59 #include <linux/slab.h> 60 #include <net/sock.h> 61 #include <net/net_namespace.h> 62 63 /* 64 * To send multiple CAN frame content within TX_SETUP or to filter 65 * CAN messages with multiplex index within RX_SETUP, the number of 66 * different filters is limited to 256 due to the one byte index value. 67 */ 68 #define MAX_NFRAMES 256 69 70 /* limit timers to 400 days for sending/timeouts */ 71 #define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60) 72 73 /* use of last_frames[index].flags */ 74 #define RX_RECV 0x40 /* received data for this element */ 75 #define RX_THR 0x80 /* element not been sent due to throttle feature */ 76 #define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */ 77 78 /* get best masking value for can_rx_register() for a given single can_id */ 79 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ 80 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ 81 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) 82 83 #define CAN_BCM_VERSION "20170425" 84 85 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 86 MODULE_LICENSE("Dual BSD/GPL"); 87 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 88 MODULE_ALIAS("can-proto-2"); 89 90 /* 91 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is 92 * 64 bit aligned so the offset has to be multiples of 8 which is ensured 93 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler(). 94 */ 95 static inline u64 get_u64(const struct canfd_frame *cp, int offset) 96 { 97 return *(u64 *)(cp->data + offset); 98 } 99 100 struct bcm_op { 101 struct list_head list; 102 int ifindex; 103 canid_t can_id; 104 u32 flags; 105 unsigned long frames_abs, frames_filtered; 106 struct bcm_timeval ival1, ival2; 107 struct hrtimer timer, thrtimer; 108 struct tasklet_struct tsklet, thrtsklet; 109 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 110 int rx_ifindex; 111 int cfsiz; 112 u32 count; 113 u32 nframes; 114 u32 currframe; 115 /* void pointers to arrays of struct can[fd]_frame */ 116 void *frames; 117 void *last_frames; 118 struct canfd_frame sframe; 119 struct canfd_frame last_sframe; 120 struct sock *sk; 121 struct net_device *rx_reg_dev; 122 }; 123 124 struct bcm_sock { 125 struct sock sk; 126 int bound; 127 int ifindex; 128 struct notifier_block notifier; 129 struct list_head rx_ops; 130 struct list_head tx_ops; 131 unsigned long dropped_usr_msgs; 132 struct proc_dir_entry *bcm_proc_read; 133 char procname [32]; /* inode number in decimal with \0 */ 134 }; 135 136 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 137 { 138 return (struct bcm_sock *)sk; 139 } 140 141 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 142 { 143 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 144 } 145 146 /* check limitations for timeval provided by user */ 147 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 148 { 149 if ((msg_head->ival1.tv_sec < 0) || 150 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 151 (msg_head->ival1.tv_usec < 0) || 152 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 153 (msg_head->ival2.tv_sec < 0) || 154 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 155 (msg_head->ival2.tv_usec < 0) || 156 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 157 return true; 158 159 return false; 160 } 161 162 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 163 #define OPSIZ sizeof(struct bcm_op) 164 #define MHSIZ sizeof(struct bcm_msg_head) 165 166 /* 167 * procfs functions 168 */ 169 #if IS_ENABLED(CONFIG_PROC_FS) 170 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 171 { 172 struct net_device *dev; 173 174 if (!ifindex) 175 return "any"; 176 177 rcu_read_lock(); 178 dev = dev_get_by_index_rcu(net, ifindex); 179 if (dev) 180 strcpy(result, dev->name); 181 else 182 strcpy(result, "???"); 183 rcu_read_unlock(); 184 185 return result; 186 } 187 188 static int bcm_proc_show(struct seq_file *m, void *v) 189 { 190 char ifname[IFNAMSIZ]; 191 struct net *net = m->private; 192 struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode); 193 struct bcm_sock *bo = bcm_sk(sk); 194 struct bcm_op *op; 195 196 seq_printf(m, ">>> socket %pK", sk->sk_socket); 197 seq_printf(m, " / sk %pK", sk); 198 seq_printf(m, " / bo %pK", bo); 199 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 200 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 201 seq_printf(m, " <<<\n"); 202 203 list_for_each_entry(op, &bo->rx_ops, list) { 204 205 unsigned long reduction; 206 207 /* print only active entries & prevent division by zero */ 208 if (!op->frames_abs) 209 continue; 210 211 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 212 bcm_proc_getifname(net, ifname, op->ifindex)); 213 214 if (op->flags & CAN_FD_FRAME) 215 seq_printf(m, "(%u)", op->nframes); 216 else 217 seq_printf(m, "[%u]", op->nframes); 218 219 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 220 221 if (op->kt_ival1) 222 seq_printf(m, "timeo=%lld ", 223 (long long)ktime_to_us(op->kt_ival1)); 224 225 if (op->kt_ival2) 226 seq_printf(m, "thr=%lld ", 227 (long long)ktime_to_us(op->kt_ival2)); 228 229 seq_printf(m, "# recv %ld (%ld) => reduction: ", 230 op->frames_filtered, op->frames_abs); 231 232 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 233 234 seq_printf(m, "%s%ld%%\n", 235 (reduction == 100) ? "near " : "", reduction); 236 } 237 238 list_for_each_entry(op, &bo->tx_ops, list) { 239 240 seq_printf(m, "tx_op: %03X %s ", op->can_id, 241 bcm_proc_getifname(net, ifname, op->ifindex)); 242 243 if (op->flags & CAN_FD_FRAME) 244 seq_printf(m, "(%u) ", op->nframes); 245 else 246 seq_printf(m, "[%u] ", op->nframes); 247 248 if (op->kt_ival1) 249 seq_printf(m, "t1=%lld ", 250 (long long)ktime_to_us(op->kt_ival1)); 251 252 if (op->kt_ival2) 253 seq_printf(m, "t2=%lld ", 254 (long long)ktime_to_us(op->kt_ival2)); 255 256 seq_printf(m, "# sent %ld\n", op->frames_abs); 257 } 258 seq_putc(m, '\n'); 259 return 0; 260 } 261 #endif /* CONFIG_PROC_FS */ 262 263 /* 264 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 265 * of the given bcm tx op 266 */ 267 static void bcm_can_tx(struct bcm_op *op) 268 { 269 struct sk_buff *skb; 270 struct net_device *dev; 271 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 272 273 /* no target device? => exit */ 274 if (!op->ifindex) 275 return; 276 277 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 278 if (!dev) { 279 /* RFC: should this bcm_op remove itself here? */ 280 return; 281 } 282 283 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 284 if (!skb) 285 goto out; 286 287 can_skb_reserve(skb); 288 can_skb_prv(skb)->ifindex = dev->ifindex; 289 can_skb_prv(skb)->skbcnt = 0; 290 291 skb_put_data(skb, cf, op->cfsiz); 292 293 /* send with loopback */ 294 skb->dev = dev; 295 can_skb_set_owner(skb, op->sk); 296 can_send(skb, 1); 297 298 /* update statistics */ 299 op->currframe++; 300 op->frames_abs++; 301 302 /* reached last frame? */ 303 if (op->currframe >= op->nframes) 304 op->currframe = 0; 305 out: 306 dev_put(dev); 307 } 308 309 /* 310 * bcm_send_to_user - send a BCM message to the userspace 311 * (consisting of bcm_msg_head + x CAN frames) 312 */ 313 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 314 struct canfd_frame *frames, int has_timestamp) 315 { 316 struct sk_buff *skb; 317 struct canfd_frame *firstframe; 318 struct sockaddr_can *addr; 319 struct sock *sk = op->sk; 320 unsigned int datalen = head->nframes * op->cfsiz; 321 int err; 322 323 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 324 if (!skb) 325 return; 326 327 skb_put_data(skb, head, sizeof(*head)); 328 329 if (head->nframes) { 330 /* CAN frames starting here */ 331 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 332 333 skb_put_data(skb, frames, datalen); 334 335 /* 336 * the BCM uses the flags-element of the canfd_frame 337 * structure for internal purposes. This is only 338 * relevant for updates that are generated by the 339 * BCM, where nframes is 1 340 */ 341 if (head->nframes == 1) 342 firstframe->flags &= BCM_CAN_FLAGS_MASK; 343 } 344 345 if (has_timestamp) { 346 /* restore rx timestamp */ 347 skb->tstamp = op->rx_stamp; 348 } 349 350 /* 351 * Put the datagram to the queue so that bcm_recvmsg() can 352 * get it from there. We need to pass the interface index to 353 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 354 * containing the interface index. 355 */ 356 357 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 358 addr = (struct sockaddr_can *)skb->cb; 359 memset(addr, 0, sizeof(*addr)); 360 addr->can_family = AF_CAN; 361 addr->can_ifindex = op->rx_ifindex; 362 363 err = sock_queue_rcv_skb(sk, skb); 364 if (err < 0) { 365 struct bcm_sock *bo = bcm_sk(sk); 366 367 kfree_skb(skb); 368 /* don't care about overflows in this statistic */ 369 bo->dropped_usr_msgs++; 370 } 371 } 372 373 static void bcm_tx_start_timer(struct bcm_op *op) 374 { 375 if (op->kt_ival1 && op->count) 376 hrtimer_start(&op->timer, 377 ktime_add(ktime_get(), op->kt_ival1), 378 HRTIMER_MODE_ABS); 379 else if (op->kt_ival2) 380 hrtimer_start(&op->timer, 381 ktime_add(ktime_get(), op->kt_ival2), 382 HRTIMER_MODE_ABS); 383 } 384 385 static void bcm_tx_timeout_tsklet(unsigned long data) 386 { 387 struct bcm_op *op = (struct bcm_op *)data; 388 struct bcm_msg_head msg_head; 389 390 if (op->kt_ival1 && (op->count > 0)) { 391 392 op->count--; 393 if (!op->count && (op->flags & TX_COUNTEVT)) { 394 395 /* create notification to user */ 396 msg_head.opcode = TX_EXPIRED; 397 msg_head.flags = op->flags; 398 msg_head.count = op->count; 399 msg_head.ival1 = op->ival1; 400 msg_head.ival2 = op->ival2; 401 msg_head.can_id = op->can_id; 402 msg_head.nframes = 0; 403 404 bcm_send_to_user(op, &msg_head, NULL, 0); 405 } 406 bcm_can_tx(op); 407 408 } else if (op->kt_ival2) 409 bcm_can_tx(op); 410 411 bcm_tx_start_timer(op); 412 } 413 414 /* 415 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions 416 */ 417 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 418 { 419 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 420 421 tasklet_schedule(&op->tsklet); 422 423 return HRTIMER_NORESTART; 424 } 425 426 /* 427 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 428 */ 429 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 430 { 431 struct bcm_msg_head head; 432 433 /* update statistics */ 434 op->frames_filtered++; 435 436 /* prevent statistics overflow */ 437 if (op->frames_filtered > ULONG_MAX/100) 438 op->frames_filtered = op->frames_abs = 0; 439 440 /* this element is not throttled anymore */ 441 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 442 443 head.opcode = RX_CHANGED; 444 head.flags = op->flags; 445 head.count = op->count; 446 head.ival1 = op->ival1; 447 head.ival2 = op->ival2; 448 head.can_id = op->can_id; 449 head.nframes = 1; 450 451 bcm_send_to_user(op, &head, data, 1); 452 } 453 454 /* 455 * bcm_rx_update_and_send - process a detected relevant receive content change 456 * 1. update the last received data 457 * 2. send a notification to the user (if possible) 458 */ 459 static void bcm_rx_update_and_send(struct bcm_op *op, 460 struct canfd_frame *lastdata, 461 const struct canfd_frame *rxdata) 462 { 463 memcpy(lastdata, rxdata, op->cfsiz); 464 465 /* mark as used and throttled by default */ 466 lastdata->flags |= (RX_RECV|RX_THR); 467 468 /* throttling mode inactive ? */ 469 if (!op->kt_ival2) { 470 /* send RX_CHANGED to the user immediately */ 471 bcm_rx_changed(op, lastdata); 472 return; 473 } 474 475 /* with active throttling timer we are just done here */ 476 if (hrtimer_active(&op->thrtimer)) 477 return; 478 479 /* first reception with enabled throttling mode */ 480 if (!op->kt_lastmsg) 481 goto rx_changed_settime; 482 483 /* got a second frame inside a potential throttle period? */ 484 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 485 ktime_to_us(op->kt_ival2)) { 486 /* do not send the saved data - only start throttle timer */ 487 hrtimer_start(&op->thrtimer, 488 ktime_add(op->kt_lastmsg, op->kt_ival2), 489 HRTIMER_MODE_ABS); 490 return; 491 } 492 493 /* the gap was that big, that throttling was not needed here */ 494 rx_changed_settime: 495 bcm_rx_changed(op, lastdata); 496 op->kt_lastmsg = ktime_get(); 497 } 498 499 /* 500 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 501 * received data stored in op->last_frames[] 502 */ 503 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 504 const struct canfd_frame *rxdata) 505 { 506 struct canfd_frame *cf = op->frames + op->cfsiz * index; 507 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 508 int i; 509 510 /* 511 * no one uses the MSBs of flags for comparison, 512 * so we use it here to detect the first time of reception 513 */ 514 515 if (!(lcf->flags & RX_RECV)) { 516 /* received data for the first time => send update to user */ 517 bcm_rx_update_and_send(op, lcf, rxdata); 518 return; 519 } 520 521 /* do a real check in CAN frame data section */ 522 for (i = 0; i < rxdata->len; i += 8) { 523 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 524 (get_u64(cf, i) & get_u64(lcf, i))) { 525 bcm_rx_update_and_send(op, lcf, rxdata); 526 return; 527 } 528 } 529 530 if (op->flags & RX_CHECK_DLC) { 531 /* do a real check in CAN frame length */ 532 if (rxdata->len != lcf->len) { 533 bcm_rx_update_and_send(op, lcf, rxdata); 534 return; 535 } 536 } 537 } 538 539 /* 540 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 541 */ 542 static void bcm_rx_starttimer(struct bcm_op *op) 543 { 544 if (op->flags & RX_NO_AUTOTIMER) 545 return; 546 547 if (op->kt_ival1) 548 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); 549 } 550 551 static void bcm_rx_timeout_tsklet(unsigned long data) 552 { 553 struct bcm_op *op = (struct bcm_op *)data; 554 struct bcm_msg_head msg_head; 555 556 /* create notification to user */ 557 msg_head.opcode = RX_TIMEOUT; 558 msg_head.flags = op->flags; 559 msg_head.count = op->count; 560 msg_head.ival1 = op->ival1; 561 msg_head.ival2 = op->ival2; 562 msg_head.can_id = op->can_id; 563 msg_head.nframes = 0; 564 565 bcm_send_to_user(op, &msg_head, NULL, 0); 566 } 567 568 /* 569 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out 570 */ 571 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 572 { 573 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 574 575 /* schedule before NET_RX_SOFTIRQ */ 576 tasklet_hi_schedule(&op->tsklet); 577 578 /* no restart of the timer is done here! */ 579 580 /* if user wants to be informed, when cyclic CAN-Messages come back */ 581 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 582 /* clear received CAN frames to indicate 'nothing received' */ 583 memset(op->last_frames, 0, op->nframes * op->cfsiz); 584 } 585 586 return HRTIMER_NORESTART; 587 } 588 589 /* 590 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 591 */ 592 static inline int bcm_rx_do_flush(struct bcm_op *op, int update, 593 unsigned int index) 594 { 595 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 596 597 if ((op->last_frames) && (lcf->flags & RX_THR)) { 598 if (update) 599 bcm_rx_changed(op, lcf); 600 return 1; 601 } 602 return 0; 603 } 604 605 /* 606 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 607 * 608 * update == 0 : just check if throttled data is available (any irq context) 609 * update == 1 : check and send throttled data to userspace (soft_irq context) 610 */ 611 static int bcm_rx_thr_flush(struct bcm_op *op, int update) 612 { 613 int updated = 0; 614 615 if (op->nframes > 1) { 616 unsigned int i; 617 618 /* for MUX filter we start at index 1 */ 619 for (i = 1; i < op->nframes; i++) 620 updated += bcm_rx_do_flush(op, update, i); 621 622 } else { 623 /* for RX_FILTER_ID and simple filter */ 624 updated += bcm_rx_do_flush(op, update, 0); 625 } 626 627 return updated; 628 } 629 630 static void bcm_rx_thr_tsklet(unsigned long data) 631 { 632 struct bcm_op *op = (struct bcm_op *)data; 633 634 /* push the changed data to the userspace */ 635 bcm_rx_thr_flush(op, 1); 636 } 637 638 /* 639 * bcm_rx_thr_handler - the time for blocked content updates is over now: 640 * Check for throttled data and send it to the userspace 641 */ 642 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 643 { 644 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 645 646 tasklet_schedule(&op->thrtsklet); 647 648 if (bcm_rx_thr_flush(op, 0)) { 649 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); 650 return HRTIMER_RESTART; 651 } else { 652 /* rearm throttle handling */ 653 op->kt_lastmsg = 0; 654 return HRTIMER_NORESTART; 655 } 656 } 657 658 /* 659 * bcm_rx_handler - handle a CAN frame reception 660 */ 661 static void bcm_rx_handler(struct sk_buff *skb, void *data) 662 { 663 struct bcm_op *op = (struct bcm_op *)data; 664 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 665 unsigned int i; 666 667 if (op->can_id != rxframe->can_id) 668 return; 669 670 /* make sure to handle the correct frame type (CAN / CAN FD) */ 671 if (skb->len != op->cfsiz) 672 return; 673 674 /* disable timeout */ 675 hrtimer_cancel(&op->timer); 676 677 /* save rx timestamp */ 678 op->rx_stamp = skb->tstamp; 679 /* save originator for recvfrom() */ 680 op->rx_ifindex = skb->dev->ifindex; 681 /* update statistics */ 682 op->frames_abs++; 683 684 if (op->flags & RX_RTR_FRAME) { 685 /* send reply for RTR-request (placed in op->frames[0]) */ 686 bcm_can_tx(op); 687 return; 688 } 689 690 if (op->flags & RX_FILTER_ID) { 691 /* the easiest case */ 692 bcm_rx_update_and_send(op, op->last_frames, rxframe); 693 goto rx_starttimer; 694 } 695 696 if (op->nframes == 1) { 697 /* simple compare with index 0 */ 698 bcm_rx_cmp_to_index(op, 0, rxframe); 699 goto rx_starttimer; 700 } 701 702 if (op->nframes > 1) { 703 /* 704 * multiplex compare 705 * 706 * find the first multiplex mask that fits. 707 * Remark: The MUX-mask is stored in index 0 - but only the 708 * first 64 bits of the frame data[] are relevant (CAN FD) 709 */ 710 711 for (i = 1; i < op->nframes; i++) { 712 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 713 (get_u64(op->frames, 0) & 714 get_u64(op->frames + op->cfsiz * i, 0))) { 715 bcm_rx_cmp_to_index(op, i, rxframe); 716 break; 717 } 718 } 719 } 720 721 rx_starttimer: 722 bcm_rx_starttimer(op); 723 } 724 725 /* 726 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 727 */ 728 static struct bcm_op *bcm_find_op(struct list_head *ops, 729 struct bcm_msg_head *mh, int ifindex) 730 { 731 struct bcm_op *op; 732 733 list_for_each_entry(op, ops, list) { 734 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 735 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 736 return op; 737 } 738 739 return NULL; 740 } 741 742 static void bcm_remove_op(struct bcm_op *op) 743 { 744 if (op->tsklet.func) { 745 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) || 746 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) || 747 hrtimer_active(&op->timer)) { 748 hrtimer_cancel(&op->timer); 749 tasklet_kill(&op->tsklet); 750 } 751 } 752 753 if (op->thrtsklet.func) { 754 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) || 755 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) || 756 hrtimer_active(&op->thrtimer)) { 757 hrtimer_cancel(&op->thrtimer); 758 tasklet_kill(&op->thrtsklet); 759 } 760 } 761 762 if ((op->frames) && (op->frames != &op->sframe)) 763 kfree(op->frames); 764 765 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 766 kfree(op->last_frames); 767 768 kfree(op); 769 } 770 771 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 772 { 773 if (op->rx_reg_dev == dev) { 774 can_rx_unregister(dev_net(dev), dev, op->can_id, 775 REGMASK(op->can_id), bcm_rx_handler, op); 776 777 /* mark as removed subscription */ 778 op->rx_reg_dev = NULL; 779 } else 780 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 781 "mismatch %p %p\n", op->rx_reg_dev, dev); 782 } 783 784 /* 785 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 786 */ 787 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 788 int ifindex) 789 { 790 struct bcm_op *op, *n; 791 792 list_for_each_entry_safe(op, n, ops, list) { 793 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 794 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 795 796 /* 797 * Don't care if we're bound or not (due to netdev 798 * problems) can_rx_unregister() is always a save 799 * thing to do here. 800 */ 801 if (op->ifindex) { 802 /* 803 * Only remove subscriptions that had not 804 * been removed due to NETDEV_UNREGISTER 805 * in bcm_notifier() 806 */ 807 if (op->rx_reg_dev) { 808 struct net_device *dev; 809 810 dev = dev_get_by_index(sock_net(op->sk), 811 op->ifindex); 812 if (dev) { 813 bcm_rx_unreg(dev, op); 814 dev_put(dev); 815 } 816 } 817 } else 818 can_rx_unregister(sock_net(op->sk), NULL, 819 op->can_id, 820 REGMASK(op->can_id), 821 bcm_rx_handler, op); 822 823 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_delete_tx_op - find and remove a tx op (returns number of removed ops) 834 */ 835 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 836 int ifindex) 837 { 838 struct bcm_op *op, *n; 839 840 list_for_each_entry_safe(op, n, ops, list) { 841 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 842 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 843 list_del(&op->list); 844 bcm_remove_op(op); 845 return 1; /* done */ 846 } 847 } 848 849 return 0; /* not found */ 850 } 851 852 /* 853 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 854 */ 855 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 856 int ifindex) 857 { 858 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 859 860 if (!op) 861 return -EINVAL; 862 863 /* put current values into msg_head */ 864 msg_head->flags = op->flags; 865 msg_head->count = op->count; 866 msg_head->ival1 = op->ival1; 867 msg_head->ival2 = op->ival2; 868 msg_head->nframes = op->nframes; 869 870 bcm_send_to_user(op, msg_head, op->frames, 0); 871 872 return MHSIZ; 873 } 874 875 /* 876 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 877 */ 878 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 879 int ifindex, struct sock *sk) 880 { 881 struct bcm_sock *bo = bcm_sk(sk); 882 struct bcm_op *op; 883 struct canfd_frame *cf; 884 unsigned int i; 885 int err; 886 887 /* we need a real device to send frames */ 888 if (!ifindex) 889 return -ENODEV; 890 891 /* check nframes boundaries - we need at least one CAN frame */ 892 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 893 return -EINVAL; 894 895 /* check timeval limitations */ 896 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 897 return -EINVAL; 898 899 /* check the given can_id */ 900 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 901 if (op) { 902 /* update existing BCM operation */ 903 904 /* 905 * Do we need more space for the CAN frames than currently 906 * allocated? -> This is a _really_ unusual use-case and 907 * therefore (complexity / locking) it is not supported. 908 */ 909 if (msg_head->nframes > op->nframes) 910 return -E2BIG; 911 912 /* update CAN frames content */ 913 for (i = 0; i < msg_head->nframes; i++) { 914 915 cf = op->frames + op->cfsiz * i; 916 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 917 918 if (op->flags & CAN_FD_FRAME) { 919 if (cf->len > 64) 920 err = -EINVAL; 921 } else { 922 if (cf->len > 8) 923 err = -EINVAL; 924 } 925 926 if (err < 0) 927 return err; 928 929 if (msg_head->flags & TX_CP_CAN_ID) { 930 /* copy can_id into frame */ 931 cf->can_id = msg_head->can_id; 932 } 933 } 934 op->flags = msg_head->flags; 935 936 } else { 937 /* insert new BCM operation for the given can_id */ 938 939 op = kzalloc(OPSIZ, GFP_KERNEL); 940 if (!op) 941 return -ENOMEM; 942 943 op->can_id = msg_head->can_id; 944 op->cfsiz = CFSIZ(msg_head->flags); 945 op->flags = msg_head->flags; 946 947 /* create array for CAN frames and copy the data */ 948 if (msg_head->nframes > 1) { 949 op->frames = kmalloc_array(msg_head->nframes, 950 op->cfsiz, 951 GFP_KERNEL); 952 if (!op->frames) { 953 kfree(op); 954 return -ENOMEM; 955 } 956 } else 957 op->frames = &op->sframe; 958 959 for (i = 0; i < msg_head->nframes; i++) { 960 961 cf = op->frames + op->cfsiz * i; 962 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 963 964 if (op->flags & CAN_FD_FRAME) { 965 if (cf->len > 64) 966 err = -EINVAL; 967 } else { 968 if (cf->len > 8) 969 err = -EINVAL; 970 } 971 972 if (err < 0) { 973 if (op->frames != &op->sframe) 974 kfree(op->frames); 975 kfree(op); 976 return err; 977 } 978 979 if (msg_head->flags & TX_CP_CAN_ID) { 980 /* copy can_id into frame */ 981 cf->can_id = msg_head->can_id; 982 } 983 } 984 985 /* tx_ops never compare with previous received messages */ 986 op->last_frames = NULL; 987 988 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 989 op->sk = sk; 990 op->ifindex = ifindex; 991 992 /* initialize uninitialized (kzalloc) structure */ 993 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 994 op->timer.function = bcm_tx_timeout_handler; 995 996 /* initialize tasklet for tx countevent notification */ 997 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, 998 (unsigned long) op); 999 1000 /* currently unused in tx_ops */ 1001 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1002 1003 /* add this bcm_op to the list of the tx_ops */ 1004 list_add(&op->list, &bo->tx_ops); 1005 1006 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 1007 1008 if (op->nframes != msg_head->nframes) { 1009 op->nframes = msg_head->nframes; 1010 /* start multiple frame transmission with index 0 */ 1011 op->currframe = 0; 1012 } 1013 1014 /* check flags */ 1015 1016 if (op->flags & TX_RESET_MULTI_IDX) { 1017 /* start multiple frame transmission with index 0 */ 1018 op->currframe = 0; 1019 } 1020 1021 if (op->flags & SETTIMER) { 1022 /* set timer values */ 1023 op->count = msg_head->count; 1024 op->ival1 = msg_head->ival1; 1025 op->ival2 = msg_head->ival2; 1026 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1027 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1028 1029 /* disable an active timer due to zero values? */ 1030 if (!op->kt_ival1 && !op->kt_ival2) 1031 hrtimer_cancel(&op->timer); 1032 } 1033 1034 if (op->flags & STARTTIMER) { 1035 hrtimer_cancel(&op->timer); 1036 /* spec: send CAN frame when starting timer */ 1037 op->flags |= TX_ANNOUNCE; 1038 } 1039 1040 if (op->flags & TX_ANNOUNCE) { 1041 bcm_can_tx(op); 1042 if (op->count) 1043 op->count--; 1044 } 1045 1046 if (op->flags & STARTTIMER) 1047 bcm_tx_start_timer(op); 1048 1049 return msg_head->nframes * op->cfsiz + MHSIZ; 1050 } 1051 1052 /* 1053 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1054 */ 1055 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1056 int ifindex, struct sock *sk) 1057 { 1058 struct bcm_sock *bo = bcm_sk(sk); 1059 struct bcm_op *op; 1060 int do_rx_register; 1061 int err = 0; 1062 1063 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1064 /* be robust against wrong usage ... */ 1065 msg_head->flags |= RX_FILTER_ID; 1066 /* ignore trailing garbage */ 1067 msg_head->nframes = 0; 1068 } 1069 1070 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1071 if (msg_head->nframes > MAX_NFRAMES + 1) 1072 return -EINVAL; 1073 1074 if ((msg_head->flags & RX_RTR_FRAME) && 1075 ((msg_head->nframes != 1) || 1076 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1077 return -EINVAL; 1078 1079 /* check timeval limitations */ 1080 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1081 return -EINVAL; 1082 1083 /* check the given can_id */ 1084 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1085 if (op) { 1086 /* update existing BCM operation */ 1087 1088 /* 1089 * Do we need more space for the CAN frames than currently 1090 * allocated? -> This is a _really_ unusual use-case and 1091 * therefore (complexity / locking) it is not supported. 1092 */ 1093 if (msg_head->nframes > op->nframes) 1094 return -E2BIG; 1095 1096 if (msg_head->nframes) { 1097 /* update CAN frames content */ 1098 err = memcpy_from_msg(op->frames, msg, 1099 msg_head->nframes * op->cfsiz); 1100 if (err < 0) 1101 return err; 1102 1103 /* clear last_frames to indicate 'nothing received' */ 1104 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1105 } 1106 1107 op->nframes = msg_head->nframes; 1108 op->flags = msg_head->flags; 1109 1110 /* Only an update -> do not call can_rx_register() */ 1111 do_rx_register = 0; 1112 1113 } else { 1114 /* insert new BCM operation for the given can_id */ 1115 op = kzalloc(OPSIZ, GFP_KERNEL); 1116 if (!op) 1117 return -ENOMEM; 1118 1119 op->can_id = msg_head->can_id; 1120 op->nframes = msg_head->nframes; 1121 op->cfsiz = CFSIZ(msg_head->flags); 1122 op->flags = msg_head->flags; 1123 1124 if (msg_head->nframes > 1) { 1125 /* create array for CAN frames and copy the data */ 1126 op->frames = kmalloc_array(msg_head->nframes, 1127 op->cfsiz, 1128 GFP_KERNEL); 1129 if (!op->frames) { 1130 kfree(op); 1131 return -ENOMEM; 1132 } 1133 1134 /* create and init array for received CAN frames */ 1135 op->last_frames = kcalloc(msg_head->nframes, 1136 op->cfsiz, 1137 GFP_KERNEL); 1138 if (!op->last_frames) { 1139 kfree(op->frames); 1140 kfree(op); 1141 return -ENOMEM; 1142 } 1143 1144 } else { 1145 op->frames = &op->sframe; 1146 op->last_frames = &op->last_sframe; 1147 } 1148 1149 if (msg_head->nframes) { 1150 err = memcpy_from_msg(op->frames, msg, 1151 msg_head->nframes * op->cfsiz); 1152 if (err < 0) { 1153 if (op->frames != &op->sframe) 1154 kfree(op->frames); 1155 if (op->last_frames != &op->last_sframe) 1156 kfree(op->last_frames); 1157 kfree(op); 1158 return err; 1159 } 1160 } 1161 1162 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1163 op->sk = sk; 1164 op->ifindex = ifindex; 1165 1166 /* ifindex for timeout events w/o previous frame reception */ 1167 op->rx_ifindex = ifindex; 1168 1169 /* initialize uninitialized (kzalloc) structure */ 1170 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1171 op->timer.function = bcm_rx_timeout_handler; 1172 1173 /* initialize tasklet for rx timeout notification */ 1174 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, 1175 (unsigned long) op); 1176 1177 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1178 op->thrtimer.function = bcm_rx_thr_handler; 1179 1180 /* initialize tasklet for rx throttle handling */ 1181 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, 1182 (unsigned long) op); 1183 1184 /* add this bcm_op to the list of the rx_ops */ 1185 list_add(&op->list, &bo->rx_ops); 1186 1187 /* call can_rx_register() */ 1188 do_rx_register = 1; 1189 1190 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1191 1192 /* check flags */ 1193 1194 if (op->flags & RX_RTR_FRAME) { 1195 struct canfd_frame *frame0 = op->frames; 1196 1197 /* no timers in RTR-mode */ 1198 hrtimer_cancel(&op->thrtimer); 1199 hrtimer_cancel(&op->timer); 1200 1201 /* 1202 * funny feature in RX(!)_SETUP only for RTR-mode: 1203 * copy can_id into frame BUT without RTR-flag to 1204 * prevent a full-load-loopback-test ... ;-] 1205 */ 1206 if ((op->flags & TX_CP_CAN_ID) || 1207 (frame0->can_id == op->can_id)) 1208 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1209 1210 } else { 1211 if (op->flags & SETTIMER) { 1212 1213 /* set timer value */ 1214 op->ival1 = msg_head->ival1; 1215 op->ival2 = msg_head->ival2; 1216 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1217 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1218 1219 /* disable an active timer due to zero value? */ 1220 if (!op->kt_ival1) 1221 hrtimer_cancel(&op->timer); 1222 1223 /* 1224 * In any case cancel the throttle timer, flush 1225 * potentially blocked msgs and reset throttle handling 1226 */ 1227 op->kt_lastmsg = 0; 1228 hrtimer_cancel(&op->thrtimer); 1229 bcm_rx_thr_flush(op, 1); 1230 } 1231 1232 if ((op->flags & STARTTIMER) && op->kt_ival1) 1233 hrtimer_start(&op->timer, op->kt_ival1, 1234 HRTIMER_MODE_REL); 1235 } 1236 1237 /* now we can register for can_ids, if we added a new bcm_op */ 1238 if (do_rx_register) { 1239 if (ifindex) { 1240 struct net_device *dev; 1241 1242 dev = dev_get_by_index(sock_net(sk), ifindex); 1243 if (dev) { 1244 err = can_rx_register(sock_net(sk), dev, 1245 op->can_id, 1246 REGMASK(op->can_id), 1247 bcm_rx_handler, op, 1248 "bcm", sk); 1249 1250 op->rx_reg_dev = dev; 1251 dev_put(dev); 1252 } 1253 1254 } else 1255 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1256 REGMASK(op->can_id), 1257 bcm_rx_handler, op, "bcm", sk); 1258 if (err) { 1259 /* this bcm rx op is broken -> remove it */ 1260 list_del(&op->list); 1261 bcm_remove_op(op); 1262 return err; 1263 } 1264 } 1265 1266 return msg_head->nframes * op->cfsiz + MHSIZ; 1267 } 1268 1269 /* 1270 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1271 */ 1272 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1273 int cfsiz) 1274 { 1275 struct sk_buff *skb; 1276 struct net_device *dev; 1277 int err; 1278 1279 /* we need a real device to send frames */ 1280 if (!ifindex) 1281 return -ENODEV; 1282 1283 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1284 if (!skb) 1285 return -ENOMEM; 1286 1287 can_skb_reserve(skb); 1288 1289 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1290 if (err < 0) { 1291 kfree_skb(skb); 1292 return err; 1293 } 1294 1295 dev = dev_get_by_index(sock_net(sk), ifindex); 1296 if (!dev) { 1297 kfree_skb(skb); 1298 return -ENODEV; 1299 } 1300 1301 can_skb_prv(skb)->ifindex = dev->ifindex; 1302 can_skb_prv(skb)->skbcnt = 0; 1303 skb->dev = dev; 1304 can_skb_set_owner(skb, sk); 1305 err = can_send(skb, 1); /* send with loopback */ 1306 dev_put(dev); 1307 1308 if (err) 1309 return err; 1310 1311 return cfsiz + MHSIZ; 1312 } 1313 1314 /* 1315 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1316 */ 1317 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1318 { 1319 struct sock *sk = sock->sk; 1320 struct bcm_sock *bo = bcm_sk(sk); 1321 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1322 struct bcm_msg_head msg_head; 1323 int cfsiz; 1324 int ret; /* read bytes or error codes as return value */ 1325 1326 if (!bo->bound) 1327 return -ENOTCONN; 1328 1329 /* check for valid message length from userspace */ 1330 if (size < MHSIZ) 1331 return -EINVAL; 1332 1333 /* read message head information */ 1334 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1335 if (ret < 0) 1336 return ret; 1337 1338 cfsiz = CFSIZ(msg_head.flags); 1339 if ((size - MHSIZ) % cfsiz) 1340 return -EINVAL; 1341 1342 /* check for alternative ifindex for this bcm_op */ 1343 1344 if (!ifindex && msg->msg_name) { 1345 /* no bound device as default => check msg_name */ 1346 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1347 1348 if (msg->msg_namelen < sizeof(*addr)) 1349 return -EINVAL; 1350 1351 if (addr->can_family != AF_CAN) 1352 return -EINVAL; 1353 1354 /* ifindex from sendto() */ 1355 ifindex = addr->can_ifindex; 1356 1357 if (ifindex) { 1358 struct net_device *dev; 1359 1360 dev = dev_get_by_index(sock_net(sk), ifindex); 1361 if (!dev) 1362 return -ENODEV; 1363 1364 if (dev->type != ARPHRD_CAN) { 1365 dev_put(dev); 1366 return -ENODEV; 1367 } 1368 1369 dev_put(dev); 1370 } 1371 } 1372 1373 lock_sock(sk); 1374 1375 switch (msg_head.opcode) { 1376 1377 case TX_SETUP: 1378 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1379 break; 1380 1381 case RX_SETUP: 1382 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1383 break; 1384 1385 case TX_DELETE: 1386 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1387 ret = MHSIZ; 1388 else 1389 ret = -EINVAL; 1390 break; 1391 1392 case RX_DELETE: 1393 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1394 ret = MHSIZ; 1395 else 1396 ret = -EINVAL; 1397 break; 1398 1399 case TX_READ: 1400 /* reuse msg_head for the reply to TX_READ */ 1401 msg_head.opcode = TX_STATUS; 1402 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1403 break; 1404 1405 case RX_READ: 1406 /* reuse msg_head for the reply to RX_READ */ 1407 msg_head.opcode = RX_STATUS; 1408 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1409 break; 1410 1411 case TX_SEND: 1412 /* we need exactly one CAN frame behind the msg head */ 1413 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1414 ret = -EINVAL; 1415 else 1416 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1417 break; 1418 1419 default: 1420 ret = -EINVAL; 1421 break; 1422 } 1423 1424 release_sock(sk); 1425 1426 return ret; 1427 } 1428 1429 /* 1430 * notification handler for netdevice status changes 1431 */ 1432 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1433 void *ptr) 1434 { 1435 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1436 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); 1437 struct sock *sk = &bo->sk; 1438 struct bcm_op *op; 1439 int notify_enodev = 0; 1440 1441 if (!net_eq(dev_net(dev), sock_net(sk))) 1442 return NOTIFY_DONE; 1443 1444 if (dev->type != ARPHRD_CAN) 1445 return NOTIFY_DONE; 1446 1447 switch (msg) { 1448 1449 case NETDEV_UNREGISTER: 1450 lock_sock(sk); 1451 1452 /* remove device specific receive entries */ 1453 list_for_each_entry(op, &bo->rx_ops, list) 1454 if (op->rx_reg_dev == dev) 1455 bcm_rx_unreg(dev, op); 1456 1457 /* remove device reference, if this is our bound device */ 1458 if (bo->bound && bo->ifindex == dev->ifindex) { 1459 bo->bound = 0; 1460 bo->ifindex = 0; 1461 notify_enodev = 1; 1462 } 1463 1464 release_sock(sk); 1465 1466 if (notify_enodev) { 1467 sk->sk_err = ENODEV; 1468 if (!sock_flag(sk, SOCK_DEAD)) 1469 sk->sk_error_report(sk); 1470 } 1471 break; 1472 1473 case NETDEV_DOWN: 1474 if (bo->bound && bo->ifindex == dev->ifindex) { 1475 sk->sk_err = ENETDOWN; 1476 if (!sock_flag(sk, SOCK_DEAD)) 1477 sk->sk_error_report(sk); 1478 } 1479 } 1480 1481 return NOTIFY_DONE; 1482 } 1483 1484 /* 1485 * initial settings for all BCM sockets to be set at socket creation time 1486 */ 1487 static int bcm_init(struct sock *sk) 1488 { 1489 struct bcm_sock *bo = bcm_sk(sk); 1490 1491 bo->bound = 0; 1492 bo->ifindex = 0; 1493 bo->dropped_usr_msgs = 0; 1494 bo->bcm_proc_read = NULL; 1495 1496 INIT_LIST_HEAD(&bo->tx_ops); 1497 INIT_LIST_HEAD(&bo->rx_ops); 1498 1499 /* set notifier */ 1500 bo->notifier.notifier_call = bcm_notifier; 1501 1502 register_netdevice_notifier(&bo->notifier); 1503 1504 return 0; 1505 } 1506 1507 /* 1508 * standard socket functions 1509 */ 1510 static int bcm_release(struct socket *sock) 1511 { 1512 struct sock *sk = sock->sk; 1513 struct net *net; 1514 struct bcm_sock *bo; 1515 struct bcm_op *op, *next; 1516 1517 if (!sk) 1518 return 0; 1519 1520 net = sock_net(sk); 1521 bo = bcm_sk(sk); 1522 1523 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1524 1525 unregister_netdevice_notifier(&bo->notifier); 1526 1527 lock_sock(sk); 1528 1529 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1530 bcm_remove_op(op); 1531 1532 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1533 /* 1534 * Don't care if we're bound or not (due to netdev problems) 1535 * can_rx_unregister() is always a save thing to do here. 1536 */ 1537 if (op->ifindex) { 1538 /* 1539 * Only remove subscriptions that had not 1540 * been removed due to NETDEV_UNREGISTER 1541 * in bcm_notifier() 1542 */ 1543 if (op->rx_reg_dev) { 1544 struct net_device *dev; 1545 1546 dev = dev_get_by_index(net, op->ifindex); 1547 if (dev) { 1548 bcm_rx_unreg(dev, op); 1549 dev_put(dev); 1550 } 1551 } 1552 } else 1553 can_rx_unregister(net, NULL, op->can_id, 1554 REGMASK(op->can_id), 1555 bcm_rx_handler, op); 1556 1557 bcm_remove_op(op); 1558 } 1559 1560 #if IS_ENABLED(CONFIG_PROC_FS) 1561 /* remove procfs entry */ 1562 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1563 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1564 #endif /* CONFIG_PROC_FS */ 1565 1566 /* remove device reference */ 1567 if (bo->bound) { 1568 bo->bound = 0; 1569 bo->ifindex = 0; 1570 } 1571 1572 sock_orphan(sk); 1573 sock->sk = NULL; 1574 1575 release_sock(sk); 1576 sock_put(sk); 1577 1578 return 0; 1579 } 1580 1581 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1582 int flags) 1583 { 1584 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1585 struct sock *sk = sock->sk; 1586 struct bcm_sock *bo = bcm_sk(sk); 1587 struct net *net = sock_net(sk); 1588 int ret = 0; 1589 1590 if (len < sizeof(*addr)) 1591 return -EINVAL; 1592 1593 lock_sock(sk); 1594 1595 if (bo->bound) { 1596 ret = -EISCONN; 1597 goto fail; 1598 } 1599 1600 /* bind a device to this socket */ 1601 if (addr->can_ifindex) { 1602 struct net_device *dev; 1603 1604 dev = dev_get_by_index(net, addr->can_ifindex); 1605 if (!dev) { 1606 ret = -ENODEV; 1607 goto fail; 1608 } 1609 if (dev->type != ARPHRD_CAN) { 1610 dev_put(dev); 1611 ret = -ENODEV; 1612 goto fail; 1613 } 1614 1615 bo->ifindex = dev->ifindex; 1616 dev_put(dev); 1617 1618 } else { 1619 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1620 bo->ifindex = 0; 1621 } 1622 1623 #if IS_ENABLED(CONFIG_PROC_FS) 1624 if (net->can.bcmproc_dir) { 1625 /* unique socket address as filename */ 1626 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1627 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1628 net->can.bcmproc_dir, 1629 bcm_proc_show, sk); 1630 if (!bo->bcm_proc_read) { 1631 ret = -ENOMEM; 1632 goto fail; 1633 } 1634 } 1635 #endif /* CONFIG_PROC_FS */ 1636 1637 bo->bound = 1; 1638 1639 fail: 1640 release_sock(sk); 1641 1642 return ret; 1643 } 1644 1645 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1646 int flags) 1647 { 1648 struct sock *sk = sock->sk; 1649 struct sk_buff *skb; 1650 int error = 0; 1651 int noblock; 1652 int err; 1653 1654 noblock = flags & MSG_DONTWAIT; 1655 flags &= ~MSG_DONTWAIT; 1656 skb = skb_recv_datagram(sk, flags, noblock, &error); 1657 if (!skb) 1658 return error; 1659 1660 if (skb->len < size) 1661 size = skb->len; 1662 1663 err = memcpy_to_msg(msg, skb->data, size); 1664 if (err < 0) { 1665 skb_free_datagram(sk, skb); 1666 return err; 1667 } 1668 1669 sock_recv_ts_and_drops(msg, sk, skb); 1670 1671 if (msg->msg_name) { 1672 __sockaddr_check_size(sizeof(struct sockaddr_can)); 1673 msg->msg_namelen = sizeof(struct sockaddr_can); 1674 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1675 } 1676 1677 skb_free_datagram(sk, skb); 1678 1679 return size; 1680 } 1681 1682 static const struct proto_ops bcm_ops = { 1683 .family = PF_CAN, 1684 .release = bcm_release, 1685 .bind = sock_no_bind, 1686 .connect = bcm_connect, 1687 .socketpair = sock_no_socketpair, 1688 .accept = sock_no_accept, 1689 .getname = sock_no_getname, 1690 .poll = datagram_poll, 1691 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ 1692 .listen = sock_no_listen, 1693 .shutdown = sock_no_shutdown, 1694 .setsockopt = sock_no_setsockopt, 1695 .getsockopt = sock_no_getsockopt, 1696 .sendmsg = bcm_sendmsg, 1697 .recvmsg = bcm_recvmsg, 1698 .mmap = sock_no_mmap, 1699 .sendpage = sock_no_sendpage, 1700 }; 1701 1702 static struct proto bcm_proto __read_mostly = { 1703 .name = "CAN_BCM", 1704 .owner = THIS_MODULE, 1705 .obj_size = sizeof(struct bcm_sock), 1706 .init = bcm_init, 1707 }; 1708 1709 static const struct can_proto bcm_can_proto = { 1710 .type = SOCK_DGRAM, 1711 .protocol = CAN_BCM, 1712 .ops = &bcm_ops, 1713 .prot = &bcm_proto, 1714 }; 1715 1716 static int canbcm_pernet_init(struct net *net) 1717 { 1718 #if IS_ENABLED(CONFIG_PROC_FS) 1719 /* create /proc/net/can-bcm directory */ 1720 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1721 #endif /* CONFIG_PROC_FS */ 1722 1723 return 0; 1724 } 1725 1726 static void canbcm_pernet_exit(struct net *net) 1727 { 1728 #if IS_ENABLED(CONFIG_PROC_FS) 1729 /* remove /proc/net/can-bcm directory */ 1730 if (net->can.bcmproc_dir) 1731 remove_proc_entry("can-bcm", net->proc_net); 1732 #endif /* CONFIG_PROC_FS */ 1733 } 1734 1735 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1736 .init = canbcm_pernet_init, 1737 .exit = canbcm_pernet_exit, 1738 }; 1739 1740 static int __init bcm_module_init(void) 1741 { 1742 int err; 1743 1744 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"); 1745 1746 err = can_proto_register(&bcm_can_proto); 1747 if (err < 0) { 1748 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1749 return err; 1750 } 1751 1752 register_pernet_subsys(&canbcm_pernet_ops); 1753 return 0; 1754 } 1755 1756 static void __exit bcm_module_exit(void) 1757 { 1758 can_proto_unregister(&bcm_can_proto); 1759 unregister_pernet_subsys(&canbcm_pernet_ops); 1760 } 1761 1762 module_init(bcm_module_init); 1763 module_exit(bcm_module_exit); 1764