1 /* 2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content 3 * 4 * Copyright (c) 2002-2016 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 /* use of last_frames[index].flags */ 71 #define RX_RECV 0x40 /* received data for this element */ 72 #define RX_THR 0x80 /* element not been sent due to throttle feature */ 73 #define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */ 74 75 /* get best masking value for can_rx_register() for a given single can_id */ 76 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ 77 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ 78 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) 79 80 #define CAN_BCM_VERSION "20160617" 81 82 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 83 MODULE_LICENSE("Dual BSD/GPL"); 84 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 85 MODULE_ALIAS("can-proto-2"); 86 87 /* 88 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is 89 * 64 bit aligned so the offset has to be multiples of 8 which is ensured 90 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler(). 91 */ 92 static inline u64 get_u64(const struct canfd_frame *cp, int offset) 93 { 94 return *(u64 *)(cp->data + offset); 95 } 96 97 struct bcm_op { 98 struct list_head list; 99 int ifindex; 100 canid_t can_id; 101 u32 flags; 102 unsigned long frames_abs, frames_filtered; 103 struct bcm_timeval ival1, ival2; 104 struct hrtimer timer, thrtimer; 105 struct tasklet_struct tsklet, thrtsklet; 106 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 107 int rx_ifindex; 108 int cfsiz; 109 u32 count; 110 u32 nframes; 111 u32 currframe; 112 struct canfd_frame *frames; 113 struct canfd_frame *last_frames; 114 struct canfd_frame sframe; 115 struct canfd_frame last_sframe; 116 struct sock *sk; 117 struct net_device *rx_reg_dev; 118 }; 119 120 static struct proc_dir_entry *proc_dir; 121 122 struct bcm_sock { 123 struct sock sk; 124 int bound; 125 int ifindex; 126 struct notifier_block notifier; 127 struct list_head rx_ops; 128 struct list_head tx_ops; 129 unsigned long dropped_usr_msgs; 130 struct proc_dir_entry *bcm_proc_read; 131 char procname [32]; /* inode number in decimal with \0 */ 132 }; 133 134 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 135 { 136 return (struct bcm_sock *)sk; 137 } 138 139 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 140 { 141 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 142 } 143 144 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 145 #define OPSIZ sizeof(struct bcm_op) 146 #define MHSIZ sizeof(struct bcm_msg_head) 147 148 /* 149 * procfs functions 150 */ 151 static char *bcm_proc_getifname(char *result, int ifindex) 152 { 153 struct net_device *dev; 154 155 if (!ifindex) 156 return "any"; 157 158 rcu_read_lock(); 159 dev = dev_get_by_index_rcu(&init_net, ifindex); 160 if (dev) 161 strcpy(result, dev->name); 162 else 163 strcpy(result, "???"); 164 rcu_read_unlock(); 165 166 return result; 167 } 168 169 static int bcm_proc_show(struct seq_file *m, void *v) 170 { 171 char ifname[IFNAMSIZ]; 172 struct sock *sk = (struct sock *)m->private; 173 struct bcm_sock *bo = bcm_sk(sk); 174 struct bcm_op *op; 175 176 seq_printf(m, ">>> socket %pK", sk->sk_socket); 177 seq_printf(m, " / sk %pK", sk); 178 seq_printf(m, " / bo %pK", bo); 179 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 180 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex)); 181 seq_printf(m, " <<<\n"); 182 183 list_for_each_entry(op, &bo->rx_ops, list) { 184 185 unsigned long reduction; 186 187 /* print only active entries & prevent division by zero */ 188 if (!op->frames_abs) 189 continue; 190 191 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 192 bcm_proc_getifname(ifname, op->ifindex)); 193 194 if (op->flags & CAN_FD_FRAME) 195 seq_printf(m, "(%u)", op->nframes); 196 else 197 seq_printf(m, "[%u]", op->nframes); 198 199 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 200 201 if (op->kt_ival1.tv64) 202 seq_printf(m, "timeo=%lld ", 203 (long long)ktime_to_us(op->kt_ival1)); 204 205 if (op->kt_ival2.tv64) 206 seq_printf(m, "thr=%lld ", 207 (long long)ktime_to_us(op->kt_ival2)); 208 209 seq_printf(m, "# recv %ld (%ld) => reduction: ", 210 op->frames_filtered, op->frames_abs); 211 212 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 213 214 seq_printf(m, "%s%ld%%\n", 215 (reduction == 100) ? "near " : "", reduction); 216 } 217 218 list_for_each_entry(op, &bo->tx_ops, list) { 219 220 seq_printf(m, "tx_op: %03X %s ", op->can_id, 221 bcm_proc_getifname(ifname, op->ifindex)); 222 223 if (op->flags & CAN_FD_FRAME) 224 seq_printf(m, "(%u) ", op->nframes); 225 else 226 seq_printf(m, "[%u] ", op->nframes); 227 228 if (op->kt_ival1.tv64) 229 seq_printf(m, "t1=%lld ", 230 (long long)ktime_to_us(op->kt_ival1)); 231 232 if (op->kt_ival2.tv64) 233 seq_printf(m, "t2=%lld ", 234 (long long)ktime_to_us(op->kt_ival2)); 235 236 seq_printf(m, "# sent %ld\n", op->frames_abs); 237 } 238 seq_putc(m, '\n'); 239 return 0; 240 } 241 242 static int bcm_proc_open(struct inode *inode, struct file *file) 243 { 244 return single_open(file, bcm_proc_show, PDE_DATA(inode)); 245 } 246 247 static const struct file_operations bcm_proc_fops = { 248 .owner = THIS_MODULE, 249 .open = bcm_proc_open, 250 .read = seq_read, 251 .llseek = seq_lseek, 252 .release = single_release, 253 }; 254 255 /* 256 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 257 * of the given bcm tx op 258 */ 259 static void bcm_can_tx(struct bcm_op *op) 260 { 261 struct sk_buff *skb; 262 struct net_device *dev; 263 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 264 265 /* no target device? => exit */ 266 if (!op->ifindex) 267 return; 268 269 dev = dev_get_by_index(&init_net, op->ifindex); 270 if (!dev) { 271 /* RFC: should this bcm_op remove itself here? */ 272 return; 273 } 274 275 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 276 if (!skb) 277 goto out; 278 279 can_skb_reserve(skb); 280 can_skb_prv(skb)->ifindex = dev->ifindex; 281 can_skb_prv(skb)->skbcnt = 0; 282 283 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz); 284 285 /* send with loopback */ 286 skb->dev = dev; 287 can_skb_set_owner(skb, op->sk); 288 can_send(skb, 1); 289 290 /* update statistics */ 291 op->currframe++; 292 op->frames_abs++; 293 294 /* reached last frame? */ 295 if (op->currframe >= op->nframes) 296 op->currframe = 0; 297 out: 298 dev_put(dev); 299 } 300 301 /* 302 * bcm_send_to_user - send a BCM message to the userspace 303 * (consisting of bcm_msg_head + x CAN frames) 304 */ 305 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 306 struct canfd_frame *frames, int has_timestamp) 307 { 308 struct sk_buff *skb; 309 struct canfd_frame *firstframe; 310 struct sockaddr_can *addr; 311 struct sock *sk = op->sk; 312 unsigned int datalen = head->nframes * op->cfsiz; 313 int err; 314 315 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 316 if (!skb) 317 return; 318 319 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head)); 320 321 if (head->nframes) { 322 /* CAN frames starting here */ 323 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 324 325 memcpy(skb_put(skb, datalen), frames, datalen); 326 327 /* 328 * the BCM uses the flags-element of the canfd_frame 329 * structure for internal purposes. This is only 330 * relevant for updates that are generated by the 331 * BCM, where nframes is 1 332 */ 333 if (head->nframes == 1) 334 firstframe->flags &= BCM_CAN_FLAGS_MASK; 335 } 336 337 if (has_timestamp) { 338 /* restore rx timestamp */ 339 skb->tstamp = op->rx_stamp; 340 } 341 342 /* 343 * Put the datagram to the queue so that bcm_recvmsg() can 344 * get it from there. We need to pass the interface index to 345 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 346 * containing the interface index. 347 */ 348 349 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 350 addr = (struct sockaddr_can *)skb->cb; 351 memset(addr, 0, sizeof(*addr)); 352 addr->can_family = AF_CAN; 353 addr->can_ifindex = op->rx_ifindex; 354 355 err = sock_queue_rcv_skb(sk, skb); 356 if (err < 0) { 357 struct bcm_sock *bo = bcm_sk(sk); 358 359 kfree_skb(skb); 360 /* don't care about overflows in this statistic */ 361 bo->dropped_usr_msgs++; 362 } 363 } 364 365 static void bcm_tx_start_timer(struct bcm_op *op) 366 { 367 if (op->kt_ival1.tv64 && op->count) 368 hrtimer_start(&op->timer, 369 ktime_add(ktime_get(), op->kt_ival1), 370 HRTIMER_MODE_ABS); 371 else if (op->kt_ival2.tv64) 372 hrtimer_start(&op->timer, 373 ktime_add(ktime_get(), op->kt_ival2), 374 HRTIMER_MODE_ABS); 375 } 376 377 static void bcm_tx_timeout_tsklet(unsigned long data) 378 { 379 struct bcm_op *op = (struct bcm_op *)data; 380 struct bcm_msg_head msg_head; 381 382 if (op->kt_ival1.tv64 && (op->count > 0)) { 383 384 op->count--; 385 if (!op->count && (op->flags & TX_COUNTEVT)) { 386 387 /* create notification to user */ 388 msg_head.opcode = TX_EXPIRED; 389 msg_head.flags = op->flags; 390 msg_head.count = op->count; 391 msg_head.ival1 = op->ival1; 392 msg_head.ival2 = op->ival2; 393 msg_head.can_id = op->can_id; 394 msg_head.nframes = 0; 395 396 bcm_send_to_user(op, &msg_head, NULL, 0); 397 } 398 bcm_can_tx(op); 399 400 } else if (op->kt_ival2.tv64) 401 bcm_can_tx(op); 402 403 bcm_tx_start_timer(op); 404 } 405 406 /* 407 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions 408 */ 409 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 410 { 411 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 412 413 tasklet_schedule(&op->tsklet); 414 415 return HRTIMER_NORESTART; 416 } 417 418 /* 419 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 420 */ 421 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 422 { 423 struct bcm_msg_head head; 424 425 /* update statistics */ 426 op->frames_filtered++; 427 428 /* prevent statistics overflow */ 429 if (op->frames_filtered > ULONG_MAX/100) 430 op->frames_filtered = op->frames_abs = 0; 431 432 /* this element is not throttled anymore */ 433 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 434 435 head.opcode = RX_CHANGED; 436 head.flags = op->flags; 437 head.count = op->count; 438 head.ival1 = op->ival1; 439 head.ival2 = op->ival2; 440 head.can_id = op->can_id; 441 head.nframes = 1; 442 443 bcm_send_to_user(op, &head, data, 1); 444 } 445 446 /* 447 * bcm_rx_update_and_send - process a detected relevant receive content change 448 * 1. update the last received data 449 * 2. send a notification to the user (if possible) 450 */ 451 static void bcm_rx_update_and_send(struct bcm_op *op, 452 struct canfd_frame *lastdata, 453 const struct canfd_frame *rxdata) 454 { 455 memcpy(lastdata, rxdata, op->cfsiz); 456 457 /* mark as used and throttled by default */ 458 lastdata->flags |= (RX_RECV|RX_THR); 459 460 /* throttling mode inactive ? */ 461 if (!op->kt_ival2.tv64) { 462 /* send RX_CHANGED to the user immediately */ 463 bcm_rx_changed(op, lastdata); 464 return; 465 } 466 467 /* with active throttling timer we are just done here */ 468 if (hrtimer_active(&op->thrtimer)) 469 return; 470 471 /* first reception with enabled throttling mode */ 472 if (!op->kt_lastmsg.tv64) 473 goto rx_changed_settime; 474 475 /* got a second frame inside a potential throttle period? */ 476 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 477 ktime_to_us(op->kt_ival2)) { 478 /* do not send the saved data - only start throttle timer */ 479 hrtimer_start(&op->thrtimer, 480 ktime_add(op->kt_lastmsg, op->kt_ival2), 481 HRTIMER_MODE_ABS); 482 return; 483 } 484 485 /* the gap was that big, that throttling was not needed here */ 486 rx_changed_settime: 487 bcm_rx_changed(op, lastdata); 488 op->kt_lastmsg = ktime_get(); 489 } 490 491 /* 492 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 493 * received data stored in op->last_frames[] 494 */ 495 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 496 const struct canfd_frame *rxdata) 497 { 498 struct canfd_frame *cf = op->frames + op->cfsiz * index; 499 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 500 int i; 501 502 /* 503 * no one uses the MSBs of flags for comparison, 504 * so we use it here to detect the first time of reception 505 */ 506 507 if (!(lcf->flags & RX_RECV)) { 508 /* received data for the first time => send update to user */ 509 bcm_rx_update_and_send(op, lcf, rxdata); 510 return; 511 } 512 513 /* do a real check in CAN frame data section */ 514 for (i = 0; i < rxdata->len; i += 8) { 515 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 516 (get_u64(cf, i) & get_u64(lcf, i))) { 517 bcm_rx_update_and_send(op, lcf, rxdata); 518 return; 519 } 520 } 521 522 if (op->flags & RX_CHECK_DLC) { 523 /* do a real check in CAN frame length */ 524 if (rxdata->len != lcf->len) { 525 bcm_rx_update_and_send(op, lcf, rxdata); 526 return; 527 } 528 } 529 } 530 531 /* 532 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 533 */ 534 static void bcm_rx_starttimer(struct bcm_op *op) 535 { 536 if (op->flags & RX_NO_AUTOTIMER) 537 return; 538 539 if (op->kt_ival1.tv64) 540 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); 541 } 542 543 static void bcm_rx_timeout_tsklet(unsigned long data) 544 { 545 struct bcm_op *op = (struct bcm_op *)data; 546 struct bcm_msg_head msg_head; 547 548 /* create notification to user */ 549 msg_head.opcode = RX_TIMEOUT; 550 msg_head.flags = op->flags; 551 msg_head.count = op->count; 552 msg_head.ival1 = op->ival1; 553 msg_head.ival2 = op->ival2; 554 msg_head.can_id = op->can_id; 555 msg_head.nframes = 0; 556 557 bcm_send_to_user(op, &msg_head, NULL, 0); 558 } 559 560 /* 561 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out 562 */ 563 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 564 { 565 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 566 567 /* schedule before NET_RX_SOFTIRQ */ 568 tasklet_hi_schedule(&op->tsklet); 569 570 /* no restart of the timer is done here! */ 571 572 /* if user wants to be informed, when cyclic CAN-Messages come back */ 573 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 574 /* clear received CAN frames to indicate 'nothing received' */ 575 memset(op->last_frames, 0, op->nframes * op->cfsiz); 576 } 577 578 return HRTIMER_NORESTART; 579 } 580 581 /* 582 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 583 */ 584 static inline int bcm_rx_do_flush(struct bcm_op *op, int update, 585 unsigned int index) 586 { 587 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 588 589 if ((op->last_frames) && (lcf->flags & RX_THR)) { 590 if (update) 591 bcm_rx_changed(op, lcf); 592 return 1; 593 } 594 return 0; 595 } 596 597 /* 598 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 599 * 600 * update == 0 : just check if throttled data is available (any irq context) 601 * update == 1 : check and send throttled data to userspace (soft_irq context) 602 */ 603 static int bcm_rx_thr_flush(struct bcm_op *op, int update) 604 { 605 int updated = 0; 606 607 if (op->nframes > 1) { 608 unsigned int i; 609 610 /* for MUX filter we start at index 1 */ 611 for (i = 1; i < op->nframes; i++) 612 updated += bcm_rx_do_flush(op, update, i); 613 614 } else { 615 /* for RX_FILTER_ID and simple filter */ 616 updated += bcm_rx_do_flush(op, update, 0); 617 } 618 619 return updated; 620 } 621 622 static void bcm_rx_thr_tsklet(unsigned long data) 623 { 624 struct bcm_op *op = (struct bcm_op *)data; 625 626 /* push the changed data to the userspace */ 627 bcm_rx_thr_flush(op, 1); 628 } 629 630 /* 631 * bcm_rx_thr_handler - the time for blocked content updates is over now: 632 * Check for throttled data and send it to the userspace 633 */ 634 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 635 { 636 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 637 638 tasklet_schedule(&op->thrtsklet); 639 640 if (bcm_rx_thr_flush(op, 0)) { 641 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); 642 return HRTIMER_RESTART; 643 } else { 644 /* rearm throttle handling */ 645 op->kt_lastmsg = ktime_set(0, 0); 646 return HRTIMER_NORESTART; 647 } 648 } 649 650 /* 651 * bcm_rx_handler - handle a CAN frame reception 652 */ 653 static void bcm_rx_handler(struct sk_buff *skb, void *data) 654 { 655 struct bcm_op *op = (struct bcm_op *)data; 656 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 657 unsigned int i; 658 659 if (op->can_id != rxframe->can_id) 660 return; 661 662 /* make sure to handle the correct frame type (CAN / CAN FD) */ 663 if (skb->len != op->cfsiz) 664 return; 665 666 /* disable timeout */ 667 hrtimer_cancel(&op->timer); 668 669 /* save rx timestamp */ 670 op->rx_stamp = skb->tstamp; 671 /* save originator for recvfrom() */ 672 op->rx_ifindex = skb->dev->ifindex; 673 /* update statistics */ 674 op->frames_abs++; 675 676 if (op->flags & RX_RTR_FRAME) { 677 /* send reply for RTR-request (placed in op->frames[0]) */ 678 bcm_can_tx(op); 679 return; 680 } 681 682 if (op->flags & RX_FILTER_ID) { 683 /* the easiest case */ 684 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe); 685 goto rx_starttimer; 686 } 687 688 if (op->nframes == 1) { 689 /* simple compare with index 0 */ 690 bcm_rx_cmp_to_index(op, 0, rxframe); 691 goto rx_starttimer; 692 } 693 694 if (op->nframes > 1) { 695 /* 696 * multiplex compare 697 * 698 * find the first multiplex mask that fits. 699 * Remark: The MUX-mask is stored in index 0 - but only the 700 * first 64 bits of the frame data[] are relevant (CAN FD) 701 */ 702 703 for (i = 1; i < op->nframes; i++) { 704 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 705 (get_u64(op->frames, 0) & 706 get_u64(op->frames + op->cfsiz * i, 0))) { 707 bcm_rx_cmp_to_index(op, i, rxframe); 708 break; 709 } 710 } 711 } 712 713 rx_starttimer: 714 bcm_rx_starttimer(op); 715 } 716 717 /* 718 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 719 */ 720 static struct bcm_op *bcm_find_op(struct list_head *ops, 721 struct bcm_msg_head *mh, int ifindex) 722 { 723 struct bcm_op *op; 724 725 list_for_each_entry(op, ops, list) { 726 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 727 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 728 return op; 729 } 730 731 return NULL; 732 } 733 734 static void bcm_remove_op(struct bcm_op *op) 735 { 736 hrtimer_cancel(&op->timer); 737 hrtimer_cancel(&op->thrtimer); 738 739 if (op->tsklet.func) 740 tasklet_kill(&op->tsklet); 741 742 if (op->thrtsklet.func) 743 tasklet_kill(&op->thrtsklet); 744 745 if ((op->frames) && (op->frames != &op->sframe)) 746 kfree(op->frames); 747 748 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 749 kfree(op->last_frames); 750 751 kfree(op); 752 } 753 754 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 755 { 756 if (op->rx_reg_dev == dev) { 757 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id), 758 bcm_rx_handler, op); 759 760 /* mark as removed subscription */ 761 op->rx_reg_dev = NULL; 762 } else 763 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 764 "mismatch %p %p\n", op->rx_reg_dev, dev); 765 } 766 767 /* 768 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 769 */ 770 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 771 int ifindex) 772 { 773 struct bcm_op *op, *n; 774 775 list_for_each_entry_safe(op, n, ops, list) { 776 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 777 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 778 779 /* 780 * Don't care if we're bound or not (due to netdev 781 * problems) can_rx_unregister() is always a save 782 * thing to do here. 783 */ 784 if (op->ifindex) { 785 /* 786 * Only remove subscriptions that had not 787 * been removed due to NETDEV_UNREGISTER 788 * in bcm_notifier() 789 */ 790 if (op->rx_reg_dev) { 791 struct net_device *dev; 792 793 dev = dev_get_by_index(&init_net, 794 op->ifindex); 795 if (dev) { 796 bcm_rx_unreg(dev, op); 797 dev_put(dev); 798 } 799 } 800 } else 801 can_rx_unregister(NULL, op->can_id, 802 REGMASK(op->can_id), 803 bcm_rx_handler, op); 804 805 list_del(&op->list); 806 bcm_remove_op(op); 807 return 1; /* done */ 808 } 809 } 810 811 return 0; /* not found */ 812 } 813 814 /* 815 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 816 */ 817 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 818 int ifindex) 819 { 820 struct bcm_op *op, *n; 821 822 list_for_each_entry_safe(op, n, ops, list) { 823 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 824 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 825 list_del(&op->list); 826 bcm_remove_op(op); 827 return 1; /* done */ 828 } 829 } 830 831 return 0; /* not found */ 832 } 833 834 /* 835 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 836 */ 837 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 838 int ifindex) 839 { 840 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 841 842 if (!op) 843 return -EINVAL; 844 845 /* put current values into msg_head */ 846 msg_head->flags = op->flags; 847 msg_head->count = op->count; 848 msg_head->ival1 = op->ival1; 849 msg_head->ival2 = op->ival2; 850 msg_head->nframes = op->nframes; 851 852 bcm_send_to_user(op, msg_head, op->frames, 0); 853 854 return MHSIZ; 855 } 856 857 /* 858 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 859 */ 860 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 861 int ifindex, struct sock *sk) 862 { 863 struct bcm_sock *bo = bcm_sk(sk); 864 struct bcm_op *op; 865 struct canfd_frame *cf; 866 unsigned int i; 867 int err; 868 869 /* we need a real device to send frames */ 870 if (!ifindex) 871 return -ENODEV; 872 873 /* check nframes boundaries - we need at least one CAN frame */ 874 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 875 return -EINVAL; 876 877 /* check the given can_id */ 878 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 879 if (op) { 880 /* update existing BCM operation */ 881 882 /* 883 * Do we need more space for the CAN frames than currently 884 * allocated? -> This is a _really_ unusual use-case and 885 * therefore (complexity / locking) it is not supported. 886 */ 887 if (msg_head->nframes > op->nframes) 888 return -E2BIG; 889 890 /* update CAN frames content */ 891 for (i = 0; i < msg_head->nframes; i++) { 892 893 cf = op->frames + op->cfsiz * i; 894 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 895 896 if (op->flags & CAN_FD_FRAME) { 897 if (cf->len > 64) 898 err = -EINVAL; 899 } else { 900 if (cf->len > 8) 901 err = -EINVAL; 902 } 903 904 if (err < 0) 905 return err; 906 907 if (msg_head->flags & TX_CP_CAN_ID) { 908 /* copy can_id into frame */ 909 cf->can_id = msg_head->can_id; 910 } 911 } 912 op->flags = msg_head->flags; 913 914 } else { 915 /* insert new BCM operation for the given can_id */ 916 917 op = kzalloc(OPSIZ, GFP_KERNEL); 918 if (!op) 919 return -ENOMEM; 920 921 op->can_id = msg_head->can_id; 922 op->cfsiz = CFSIZ(msg_head->flags); 923 op->flags = msg_head->flags; 924 925 /* create array for CAN frames and copy the data */ 926 if (msg_head->nframes > 1) { 927 op->frames = kmalloc(msg_head->nframes * op->cfsiz, 928 GFP_KERNEL); 929 if (!op->frames) { 930 kfree(op); 931 return -ENOMEM; 932 } 933 } else 934 op->frames = &op->sframe; 935 936 for (i = 0; i < msg_head->nframes; i++) { 937 938 cf = op->frames + op->cfsiz * i; 939 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 940 941 if (op->flags & CAN_FD_FRAME) { 942 if (cf->len > 64) 943 err = -EINVAL; 944 } else { 945 if (cf->len > 8) 946 err = -EINVAL; 947 } 948 949 if (err < 0) { 950 if (op->frames != &op->sframe) 951 kfree(op->frames); 952 kfree(op); 953 return err; 954 } 955 956 if (msg_head->flags & TX_CP_CAN_ID) { 957 /* copy can_id into frame */ 958 cf->can_id = msg_head->can_id; 959 } 960 } 961 962 /* tx_ops never compare with previous received messages */ 963 op->last_frames = NULL; 964 965 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 966 op->sk = sk; 967 op->ifindex = ifindex; 968 969 /* initialize uninitialized (kzalloc) structure */ 970 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 971 op->timer.function = bcm_tx_timeout_handler; 972 973 /* initialize tasklet for tx countevent notification */ 974 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, 975 (unsigned long) op); 976 977 /* currently unused in tx_ops */ 978 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 979 980 /* add this bcm_op to the list of the tx_ops */ 981 list_add(&op->list, &bo->tx_ops); 982 983 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 984 985 if (op->nframes != msg_head->nframes) { 986 op->nframes = msg_head->nframes; 987 /* start multiple frame transmission with index 0 */ 988 op->currframe = 0; 989 } 990 991 /* check flags */ 992 993 if (op->flags & TX_RESET_MULTI_IDX) { 994 /* start multiple frame transmission with index 0 */ 995 op->currframe = 0; 996 } 997 998 if (op->flags & SETTIMER) { 999 /* set timer values */ 1000 op->count = msg_head->count; 1001 op->ival1 = msg_head->ival1; 1002 op->ival2 = msg_head->ival2; 1003 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1004 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1005 1006 /* disable an active timer due to zero values? */ 1007 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64) 1008 hrtimer_cancel(&op->timer); 1009 } 1010 1011 if (op->flags & STARTTIMER) { 1012 hrtimer_cancel(&op->timer); 1013 /* spec: send CAN frame when starting timer */ 1014 op->flags |= TX_ANNOUNCE; 1015 } 1016 1017 if (op->flags & TX_ANNOUNCE) { 1018 bcm_can_tx(op); 1019 if (op->count) 1020 op->count--; 1021 } 1022 1023 if (op->flags & STARTTIMER) 1024 bcm_tx_start_timer(op); 1025 1026 return msg_head->nframes * op->cfsiz + MHSIZ; 1027 } 1028 1029 /* 1030 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1031 */ 1032 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1033 int ifindex, struct sock *sk) 1034 { 1035 struct bcm_sock *bo = bcm_sk(sk); 1036 struct bcm_op *op; 1037 int do_rx_register; 1038 int err = 0; 1039 1040 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1041 /* be robust against wrong usage ... */ 1042 msg_head->flags |= RX_FILTER_ID; 1043 /* ignore trailing garbage */ 1044 msg_head->nframes = 0; 1045 } 1046 1047 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1048 if (msg_head->nframes > MAX_NFRAMES + 1) 1049 return -EINVAL; 1050 1051 if ((msg_head->flags & RX_RTR_FRAME) && 1052 ((msg_head->nframes != 1) || 1053 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1054 return -EINVAL; 1055 1056 /* check the given can_id */ 1057 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1058 if (op) { 1059 /* update existing BCM operation */ 1060 1061 /* 1062 * Do we need more space for the CAN frames than currently 1063 * allocated? -> This is a _really_ unusual use-case and 1064 * therefore (complexity / locking) it is not supported. 1065 */ 1066 if (msg_head->nframes > op->nframes) 1067 return -E2BIG; 1068 1069 if (msg_head->nframes) { 1070 /* update CAN frames content */ 1071 err = memcpy_from_msg((u8 *)op->frames, msg, 1072 msg_head->nframes * op->cfsiz); 1073 if (err < 0) 1074 return err; 1075 1076 /* clear last_frames to indicate 'nothing received' */ 1077 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1078 } 1079 1080 op->nframes = msg_head->nframes; 1081 op->flags = msg_head->flags; 1082 1083 /* Only an update -> do not call can_rx_register() */ 1084 do_rx_register = 0; 1085 1086 } else { 1087 /* insert new BCM operation for the given can_id */ 1088 op = kzalloc(OPSIZ, GFP_KERNEL); 1089 if (!op) 1090 return -ENOMEM; 1091 1092 op->can_id = msg_head->can_id; 1093 op->nframes = msg_head->nframes; 1094 op->cfsiz = CFSIZ(msg_head->flags); 1095 op->flags = msg_head->flags; 1096 1097 if (msg_head->nframes > 1) { 1098 /* create array for CAN frames and copy the data */ 1099 op->frames = kmalloc(msg_head->nframes * op->cfsiz, 1100 GFP_KERNEL); 1101 if (!op->frames) { 1102 kfree(op); 1103 return -ENOMEM; 1104 } 1105 1106 /* create and init array for received CAN frames */ 1107 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz, 1108 GFP_KERNEL); 1109 if (!op->last_frames) { 1110 kfree(op->frames); 1111 kfree(op); 1112 return -ENOMEM; 1113 } 1114 1115 } else { 1116 op->frames = &op->sframe; 1117 op->last_frames = &op->last_sframe; 1118 } 1119 1120 if (msg_head->nframes) { 1121 err = memcpy_from_msg((u8 *)op->frames, msg, 1122 msg_head->nframes * op->cfsiz); 1123 if (err < 0) { 1124 if (op->frames != &op->sframe) 1125 kfree(op->frames); 1126 if (op->last_frames != &op->last_sframe) 1127 kfree(op->last_frames); 1128 kfree(op); 1129 return err; 1130 } 1131 } 1132 1133 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1134 op->sk = sk; 1135 op->ifindex = ifindex; 1136 1137 /* ifindex for timeout events w/o previous frame reception */ 1138 op->rx_ifindex = ifindex; 1139 1140 /* initialize uninitialized (kzalloc) structure */ 1141 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1142 op->timer.function = bcm_rx_timeout_handler; 1143 1144 /* initialize tasklet for rx timeout notification */ 1145 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, 1146 (unsigned long) op); 1147 1148 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1149 op->thrtimer.function = bcm_rx_thr_handler; 1150 1151 /* initialize tasklet for rx throttle handling */ 1152 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, 1153 (unsigned long) op); 1154 1155 /* add this bcm_op to the list of the rx_ops */ 1156 list_add(&op->list, &bo->rx_ops); 1157 1158 /* call can_rx_register() */ 1159 do_rx_register = 1; 1160 1161 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1162 1163 /* check flags */ 1164 1165 if (op->flags & RX_RTR_FRAME) { 1166 1167 /* no timers in RTR-mode */ 1168 hrtimer_cancel(&op->thrtimer); 1169 hrtimer_cancel(&op->timer); 1170 1171 /* 1172 * funny feature in RX(!)_SETUP only for RTR-mode: 1173 * copy can_id into frame BUT without RTR-flag to 1174 * prevent a full-load-loopback-test ... ;-] 1175 */ 1176 if ((op->flags & TX_CP_CAN_ID) || 1177 (op->frames[0].can_id == op->can_id)) 1178 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG; 1179 1180 } else { 1181 if (op->flags & SETTIMER) { 1182 1183 /* set timer value */ 1184 op->ival1 = msg_head->ival1; 1185 op->ival2 = msg_head->ival2; 1186 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1187 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1188 1189 /* disable an active timer due to zero value? */ 1190 if (!op->kt_ival1.tv64) 1191 hrtimer_cancel(&op->timer); 1192 1193 /* 1194 * In any case cancel the throttle timer, flush 1195 * potentially blocked msgs and reset throttle handling 1196 */ 1197 op->kt_lastmsg = ktime_set(0, 0); 1198 hrtimer_cancel(&op->thrtimer); 1199 bcm_rx_thr_flush(op, 1); 1200 } 1201 1202 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64) 1203 hrtimer_start(&op->timer, op->kt_ival1, 1204 HRTIMER_MODE_REL); 1205 } 1206 1207 /* now we can register for can_ids, if we added a new bcm_op */ 1208 if (do_rx_register) { 1209 if (ifindex) { 1210 struct net_device *dev; 1211 1212 dev = dev_get_by_index(&init_net, ifindex); 1213 if (dev) { 1214 err = can_rx_register(dev, op->can_id, 1215 REGMASK(op->can_id), 1216 bcm_rx_handler, op, 1217 "bcm"); 1218 1219 op->rx_reg_dev = dev; 1220 dev_put(dev); 1221 } 1222 1223 } else 1224 err = can_rx_register(NULL, op->can_id, 1225 REGMASK(op->can_id), 1226 bcm_rx_handler, op, "bcm"); 1227 if (err) { 1228 /* this bcm rx op is broken -> remove it */ 1229 list_del(&op->list); 1230 bcm_remove_op(op); 1231 return err; 1232 } 1233 } 1234 1235 return msg_head->nframes * op->cfsiz + MHSIZ; 1236 } 1237 1238 /* 1239 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1240 */ 1241 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1242 int cfsiz) 1243 { 1244 struct sk_buff *skb; 1245 struct net_device *dev; 1246 int err; 1247 1248 /* we need a real device to send frames */ 1249 if (!ifindex) 1250 return -ENODEV; 1251 1252 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1253 if (!skb) 1254 return -ENOMEM; 1255 1256 can_skb_reserve(skb); 1257 1258 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1259 if (err < 0) { 1260 kfree_skb(skb); 1261 return err; 1262 } 1263 1264 dev = dev_get_by_index(&init_net, ifindex); 1265 if (!dev) { 1266 kfree_skb(skb); 1267 return -ENODEV; 1268 } 1269 1270 can_skb_prv(skb)->ifindex = dev->ifindex; 1271 can_skb_prv(skb)->skbcnt = 0; 1272 skb->dev = dev; 1273 can_skb_set_owner(skb, sk); 1274 err = can_send(skb, 1); /* send with loopback */ 1275 dev_put(dev); 1276 1277 if (err) 1278 return err; 1279 1280 return cfsiz + MHSIZ; 1281 } 1282 1283 /* 1284 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1285 */ 1286 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1287 { 1288 struct sock *sk = sock->sk; 1289 struct bcm_sock *bo = bcm_sk(sk); 1290 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1291 struct bcm_msg_head msg_head; 1292 int cfsiz; 1293 int ret; /* read bytes or error codes as return value */ 1294 1295 if (!bo->bound) 1296 return -ENOTCONN; 1297 1298 /* check for valid message length from userspace */ 1299 if (size < MHSIZ) 1300 return -EINVAL; 1301 1302 /* read message head information */ 1303 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1304 if (ret < 0) 1305 return ret; 1306 1307 cfsiz = CFSIZ(msg_head.flags); 1308 if ((size - MHSIZ) % cfsiz) 1309 return -EINVAL; 1310 1311 /* check for alternative ifindex for this bcm_op */ 1312 1313 if (!ifindex && msg->msg_name) { 1314 /* no bound device as default => check msg_name */ 1315 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1316 1317 if (msg->msg_namelen < sizeof(*addr)) 1318 return -EINVAL; 1319 1320 if (addr->can_family != AF_CAN) 1321 return -EINVAL; 1322 1323 /* ifindex from sendto() */ 1324 ifindex = addr->can_ifindex; 1325 1326 if (ifindex) { 1327 struct net_device *dev; 1328 1329 dev = dev_get_by_index(&init_net, ifindex); 1330 if (!dev) 1331 return -ENODEV; 1332 1333 if (dev->type != ARPHRD_CAN) { 1334 dev_put(dev); 1335 return -ENODEV; 1336 } 1337 1338 dev_put(dev); 1339 } 1340 } 1341 1342 lock_sock(sk); 1343 1344 switch (msg_head.opcode) { 1345 1346 case TX_SETUP: 1347 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1348 break; 1349 1350 case RX_SETUP: 1351 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1352 break; 1353 1354 case TX_DELETE: 1355 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1356 ret = MHSIZ; 1357 else 1358 ret = -EINVAL; 1359 break; 1360 1361 case RX_DELETE: 1362 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1363 ret = MHSIZ; 1364 else 1365 ret = -EINVAL; 1366 break; 1367 1368 case TX_READ: 1369 /* reuse msg_head for the reply to TX_READ */ 1370 msg_head.opcode = TX_STATUS; 1371 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1372 break; 1373 1374 case RX_READ: 1375 /* reuse msg_head for the reply to RX_READ */ 1376 msg_head.opcode = RX_STATUS; 1377 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1378 break; 1379 1380 case TX_SEND: 1381 /* we need exactly one CAN frame behind the msg head */ 1382 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1383 ret = -EINVAL; 1384 else 1385 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1386 break; 1387 1388 default: 1389 ret = -EINVAL; 1390 break; 1391 } 1392 1393 release_sock(sk); 1394 1395 return ret; 1396 } 1397 1398 /* 1399 * notification handler for netdevice status changes 1400 */ 1401 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1402 void *ptr) 1403 { 1404 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1405 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); 1406 struct sock *sk = &bo->sk; 1407 struct bcm_op *op; 1408 int notify_enodev = 0; 1409 1410 if (!net_eq(dev_net(dev), &init_net)) 1411 return NOTIFY_DONE; 1412 1413 if (dev->type != ARPHRD_CAN) 1414 return NOTIFY_DONE; 1415 1416 switch (msg) { 1417 1418 case NETDEV_UNREGISTER: 1419 lock_sock(sk); 1420 1421 /* remove device specific receive entries */ 1422 list_for_each_entry(op, &bo->rx_ops, list) 1423 if (op->rx_reg_dev == dev) 1424 bcm_rx_unreg(dev, op); 1425 1426 /* remove device reference, if this is our bound device */ 1427 if (bo->bound && bo->ifindex == dev->ifindex) { 1428 bo->bound = 0; 1429 bo->ifindex = 0; 1430 notify_enodev = 1; 1431 } 1432 1433 release_sock(sk); 1434 1435 if (notify_enodev) { 1436 sk->sk_err = ENODEV; 1437 if (!sock_flag(sk, SOCK_DEAD)) 1438 sk->sk_error_report(sk); 1439 } 1440 break; 1441 1442 case NETDEV_DOWN: 1443 if (bo->bound && bo->ifindex == dev->ifindex) { 1444 sk->sk_err = ENETDOWN; 1445 if (!sock_flag(sk, SOCK_DEAD)) 1446 sk->sk_error_report(sk); 1447 } 1448 } 1449 1450 return NOTIFY_DONE; 1451 } 1452 1453 /* 1454 * initial settings for all BCM sockets to be set at socket creation time 1455 */ 1456 static int bcm_init(struct sock *sk) 1457 { 1458 struct bcm_sock *bo = bcm_sk(sk); 1459 1460 bo->bound = 0; 1461 bo->ifindex = 0; 1462 bo->dropped_usr_msgs = 0; 1463 bo->bcm_proc_read = NULL; 1464 1465 INIT_LIST_HEAD(&bo->tx_ops); 1466 INIT_LIST_HEAD(&bo->rx_ops); 1467 1468 /* set notifier */ 1469 bo->notifier.notifier_call = bcm_notifier; 1470 1471 register_netdevice_notifier(&bo->notifier); 1472 1473 return 0; 1474 } 1475 1476 /* 1477 * standard socket functions 1478 */ 1479 static int bcm_release(struct socket *sock) 1480 { 1481 struct sock *sk = sock->sk; 1482 struct bcm_sock *bo; 1483 struct bcm_op *op, *next; 1484 1485 if (sk == NULL) 1486 return 0; 1487 1488 bo = bcm_sk(sk); 1489 1490 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1491 1492 unregister_netdevice_notifier(&bo->notifier); 1493 1494 lock_sock(sk); 1495 1496 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1497 bcm_remove_op(op); 1498 1499 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1500 /* 1501 * Don't care if we're bound or not (due to netdev problems) 1502 * can_rx_unregister() is always a save thing to do here. 1503 */ 1504 if (op->ifindex) { 1505 /* 1506 * Only remove subscriptions that had not 1507 * been removed due to NETDEV_UNREGISTER 1508 * in bcm_notifier() 1509 */ 1510 if (op->rx_reg_dev) { 1511 struct net_device *dev; 1512 1513 dev = dev_get_by_index(&init_net, op->ifindex); 1514 if (dev) { 1515 bcm_rx_unreg(dev, op); 1516 dev_put(dev); 1517 } 1518 } 1519 } else 1520 can_rx_unregister(NULL, op->can_id, 1521 REGMASK(op->can_id), 1522 bcm_rx_handler, op); 1523 1524 bcm_remove_op(op); 1525 } 1526 1527 /* remove procfs entry */ 1528 if (proc_dir && bo->bcm_proc_read) 1529 remove_proc_entry(bo->procname, proc_dir); 1530 1531 /* remove device reference */ 1532 if (bo->bound) { 1533 bo->bound = 0; 1534 bo->ifindex = 0; 1535 } 1536 1537 sock_orphan(sk); 1538 sock->sk = NULL; 1539 1540 release_sock(sk); 1541 sock_put(sk); 1542 1543 return 0; 1544 } 1545 1546 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1547 int flags) 1548 { 1549 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1550 struct sock *sk = sock->sk; 1551 struct bcm_sock *bo = bcm_sk(sk); 1552 1553 if (len < sizeof(*addr)) 1554 return -EINVAL; 1555 1556 if (bo->bound) 1557 return -EISCONN; 1558 1559 /* bind a device to this socket */ 1560 if (addr->can_ifindex) { 1561 struct net_device *dev; 1562 1563 dev = dev_get_by_index(&init_net, addr->can_ifindex); 1564 if (!dev) 1565 return -ENODEV; 1566 1567 if (dev->type != ARPHRD_CAN) { 1568 dev_put(dev); 1569 return -ENODEV; 1570 } 1571 1572 bo->ifindex = dev->ifindex; 1573 dev_put(dev); 1574 1575 } else { 1576 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1577 bo->ifindex = 0; 1578 } 1579 1580 bo->bound = 1; 1581 1582 if (proc_dir) { 1583 /* unique socket address as filename */ 1584 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1585 bo->bcm_proc_read = proc_create_data(bo->procname, 0644, 1586 proc_dir, 1587 &bcm_proc_fops, sk); 1588 } 1589 1590 return 0; 1591 } 1592 1593 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1594 int flags) 1595 { 1596 struct sock *sk = sock->sk; 1597 struct sk_buff *skb; 1598 int error = 0; 1599 int noblock; 1600 int err; 1601 1602 noblock = flags & MSG_DONTWAIT; 1603 flags &= ~MSG_DONTWAIT; 1604 skb = skb_recv_datagram(sk, flags, noblock, &error); 1605 if (!skb) 1606 return error; 1607 1608 if (skb->len < size) 1609 size = skb->len; 1610 1611 err = memcpy_to_msg(msg, skb->data, size); 1612 if (err < 0) { 1613 skb_free_datagram(sk, skb); 1614 return err; 1615 } 1616 1617 sock_recv_ts_and_drops(msg, sk, skb); 1618 1619 if (msg->msg_name) { 1620 __sockaddr_check_size(sizeof(struct sockaddr_can)); 1621 msg->msg_namelen = sizeof(struct sockaddr_can); 1622 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1623 } 1624 1625 skb_free_datagram(sk, skb); 1626 1627 return size; 1628 } 1629 1630 static const struct proto_ops bcm_ops = { 1631 .family = PF_CAN, 1632 .release = bcm_release, 1633 .bind = sock_no_bind, 1634 .connect = bcm_connect, 1635 .socketpair = sock_no_socketpair, 1636 .accept = sock_no_accept, 1637 .getname = sock_no_getname, 1638 .poll = datagram_poll, 1639 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ 1640 .listen = sock_no_listen, 1641 .shutdown = sock_no_shutdown, 1642 .setsockopt = sock_no_setsockopt, 1643 .getsockopt = sock_no_getsockopt, 1644 .sendmsg = bcm_sendmsg, 1645 .recvmsg = bcm_recvmsg, 1646 .mmap = sock_no_mmap, 1647 .sendpage = sock_no_sendpage, 1648 }; 1649 1650 static struct proto bcm_proto __read_mostly = { 1651 .name = "CAN_BCM", 1652 .owner = THIS_MODULE, 1653 .obj_size = sizeof(struct bcm_sock), 1654 .init = bcm_init, 1655 }; 1656 1657 static const struct can_proto bcm_can_proto = { 1658 .type = SOCK_DGRAM, 1659 .protocol = CAN_BCM, 1660 .ops = &bcm_ops, 1661 .prot = &bcm_proto, 1662 }; 1663 1664 static int __init bcm_module_init(void) 1665 { 1666 int err; 1667 1668 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"); 1669 1670 err = can_proto_register(&bcm_can_proto); 1671 if (err < 0) { 1672 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1673 return err; 1674 } 1675 1676 /* create /proc/net/can-bcm directory */ 1677 proc_dir = proc_mkdir("can-bcm", init_net.proc_net); 1678 return 0; 1679 } 1680 1681 static void __exit bcm_module_exit(void) 1682 { 1683 can_proto_unregister(&bcm_can_proto); 1684 1685 if (proc_dir) 1686 remove_proc_entry("can-bcm", init_net.proc_net); 1687 } 1688 1689 module_init(bcm_module_init); 1690 module_exit(bcm_module_exit); 1691