1 /* 2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content 3 * 4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of Volkswagen nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * Alternatively, provided that this notice is retained in full, this 20 * software may be distributed under the terms of the GNU General 21 * Public License ("GPL") version 2, in which case the provisions of the 22 * GPL apply INSTEAD OF those given above. 23 * 24 * The provided data structures and external interfaces from this code 25 * are not restricted to be used by modules with a GPL compatible license. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 38 * DAMAGE. 39 * 40 */ 41 42 #include <linux/module.h> 43 #include <linux/init.h> 44 #include <linux/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/bcm.h> 58 #include <linux/slab.h> 59 #include <net/sock.h> 60 #include <net/net_namespace.h> 61 62 /* 63 * To send multiple CAN frame content within TX_SETUP or to filter 64 * CAN messages with multiplex index within RX_SETUP, the number of 65 * different filters is limited to 256 due to the one byte index value. 66 */ 67 #define MAX_NFRAMES 256 68 69 /* use of last_frames[index].can_dlc */ 70 #define RX_RECV 0x40 /* received data for this element */ 71 #define RX_THR 0x80 /* element not been sent due to throttle feature */ 72 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */ 73 74 /* get best masking value for can_rx_register() for a given single can_id */ 75 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ 76 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ 77 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) 78 79 #define CAN_BCM_VERSION CAN_VERSION 80 static __initconst const char banner[] = KERN_INFO 81 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"; 82 83 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 84 MODULE_LICENSE("Dual BSD/GPL"); 85 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 86 MODULE_ALIAS("can-proto-2"); 87 88 /* easy access to can_frame payload */ 89 static inline u64 GET_U64(const struct can_frame *cp) 90 { 91 return *(u64 *)cp->data; 92 } 93 94 struct bcm_op { 95 struct list_head list; 96 int ifindex; 97 canid_t can_id; 98 u32 flags; 99 unsigned long frames_abs, frames_filtered; 100 struct timeval ival1, ival2; 101 struct hrtimer timer, thrtimer; 102 struct tasklet_struct tsklet, thrtsklet; 103 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 104 int rx_ifindex; 105 u32 count; 106 u32 nframes; 107 u32 currframe; 108 struct can_frame *frames; 109 struct can_frame *last_frames; 110 struct can_frame sframe; 111 struct can_frame last_sframe; 112 struct sock *sk; 113 struct net_device *rx_reg_dev; 114 }; 115 116 static struct proc_dir_entry *proc_dir; 117 118 struct bcm_sock { 119 struct sock sk; 120 int bound; 121 int ifindex; 122 struct notifier_block notifier; 123 struct list_head rx_ops; 124 struct list_head tx_ops; 125 unsigned long dropped_usr_msgs; 126 struct proc_dir_entry *bcm_proc_read; 127 char procname [32]; /* inode number in decimal with \0 */ 128 }; 129 130 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 131 { 132 return (struct bcm_sock *)sk; 133 } 134 135 #define CFSIZ sizeof(struct can_frame) 136 #define OPSIZ sizeof(struct bcm_op) 137 #define MHSIZ sizeof(struct bcm_msg_head) 138 139 /* 140 * procfs functions 141 */ 142 static char *bcm_proc_getifname(char *result, int ifindex) 143 { 144 struct net_device *dev; 145 146 if (!ifindex) 147 return "any"; 148 149 rcu_read_lock(); 150 dev = dev_get_by_index_rcu(&init_net, ifindex); 151 if (dev) 152 strcpy(result, dev->name); 153 else 154 strcpy(result, "???"); 155 rcu_read_unlock(); 156 157 return result; 158 } 159 160 static int bcm_proc_show(struct seq_file *m, void *v) 161 { 162 char ifname[IFNAMSIZ]; 163 struct sock *sk = (struct sock *)m->private; 164 struct bcm_sock *bo = bcm_sk(sk); 165 struct bcm_op *op; 166 167 seq_printf(m, ">>> socket %pK", sk->sk_socket); 168 seq_printf(m, " / sk %pK", sk); 169 seq_printf(m, " / bo %pK", bo); 170 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 171 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex)); 172 seq_printf(m, " <<<\n"); 173 174 list_for_each_entry(op, &bo->rx_ops, list) { 175 176 unsigned long reduction; 177 178 /* print only active entries & prevent division by zero */ 179 if (!op->frames_abs) 180 continue; 181 182 seq_printf(m, "rx_op: %03X %-5s ", 183 op->can_id, bcm_proc_getifname(ifname, op->ifindex)); 184 seq_printf(m, "[%u]%c ", op->nframes, 185 (op->flags & RX_CHECK_DLC)?'d':' '); 186 if (op->kt_ival1.tv64) 187 seq_printf(m, "timeo=%lld ", 188 (long long) 189 ktime_to_us(op->kt_ival1)); 190 191 if (op->kt_ival2.tv64) 192 seq_printf(m, "thr=%lld ", 193 (long long) 194 ktime_to_us(op->kt_ival2)); 195 196 seq_printf(m, "# recv %ld (%ld) => reduction: ", 197 op->frames_filtered, op->frames_abs); 198 199 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 200 201 seq_printf(m, "%s%ld%%\n", 202 (reduction == 100)?"near ":"", reduction); 203 } 204 205 list_for_each_entry(op, &bo->tx_ops, list) { 206 207 seq_printf(m, "tx_op: %03X %s [%u] ", 208 op->can_id, 209 bcm_proc_getifname(ifname, op->ifindex), 210 op->nframes); 211 212 if (op->kt_ival1.tv64) 213 seq_printf(m, "t1=%lld ", 214 (long long) ktime_to_us(op->kt_ival1)); 215 216 if (op->kt_ival2.tv64) 217 seq_printf(m, "t2=%lld ", 218 (long long) ktime_to_us(op->kt_ival2)); 219 220 seq_printf(m, "# sent %ld\n", op->frames_abs); 221 } 222 seq_putc(m, '\n'); 223 return 0; 224 } 225 226 static int bcm_proc_open(struct inode *inode, struct file *file) 227 { 228 return single_open(file, bcm_proc_show, PDE(inode)->data); 229 } 230 231 static const struct file_operations bcm_proc_fops = { 232 .owner = THIS_MODULE, 233 .open = bcm_proc_open, 234 .read = seq_read, 235 .llseek = seq_lseek, 236 .release = single_release, 237 }; 238 239 /* 240 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 241 * of the given bcm tx op 242 */ 243 static void bcm_can_tx(struct bcm_op *op) 244 { 245 struct sk_buff *skb; 246 struct net_device *dev; 247 struct can_frame *cf = &op->frames[op->currframe]; 248 249 /* no target device? => exit */ 250 if (!op->ifindex) 251 return; 252 253 dev = dev_get_by_index(&init_net, op->ifindex); 254 if (!dev) { 255 /* RFC: should this bcm_op remove itself here? */ 256 return; 257 } 258 259 skb = alloc_skb(CFSIZ, gfp_any()); 260 if (!skb) 261 goto out; 262 263 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ); 264 265 /* send with loopback */ 266 skb->dev = dev; 267 skb->sk = op->sk; 268 can_send(skb, 1); 269 270 /* update statistics */ 271 op->currframe++; 272 op->frames_abs++; 273 274 /* reached last frame? */ 275 if (op->currframe >= op->nframes) 276 op->currframe = 0; 277 out: 278 dev_put(dev); 279 } 280 281 /* 282 * bcm_send_to_user - send a BCM message to the userspace 283 * (consisting of bcm_msg_head + x CAN frames) 284 */ 285 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 286 struct can_frame *frames, int has_timestamp) 287 { 288 struct sk_buff *skb; 289 struct can_frame *firstframe; 290 struct sockaddr_can *addr; 291 struct sock *sk = op->sk; 292 unsigned int datalen = head->nframes * CFSIZ; 293 int err; 294 295 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 296 if (!skb) 297 return; 298 299 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head)); 300 301 if (head->nframes) { 302 /* can_frames starting here */ 303 firstframe = (struct can_frame *)skb_tail_pointer(skb); 304 305 memcpy(skb_put(skb, datalen), frames, datalen); 306 307 /* 308 * the BCM uses the can_dlc-element of the can_frame 309 * structure for internal purposes. This is only 310 * relevant for updates that are generated by the 311 * BCM, where nframes is 1 312 */ 313 if (head->nframes == 1) 314 firstframe->can_dlc &= BCM_CAN_DLC_MASK; 315 } 316 317 if (has_timestamp) { 318 /* restore rx timestamp */ 319 skb->tstamp = op->rx_stamp; 320 } 321 322 /* 323 * Put the datagram to the queue so that bcm_recvmsg() can 324 * get it from there. We need to pass the interface index to 325 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 326 * containing the interface index. 327 */ 328 329 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can)); 330 addr = (struct sockaddr_can *)skb->cb; 331 memset(addr, 0, sizeof(*addr)); 332 addr->can_family = AF_CAN; 333 addr->can_ifindex = op->rx_ifindex; 334 335 err = sock_queue_rcv_skb(sk, skb); 336 if (err < 0) { 337 struct bcm_sock *bo = bcm_sk(sk); 338 339 kfree_skb(skb); 340 /* don't care about overflows in this statistic */ 341 bo->dropped_usr_msgs++; 342 } 343 } 344 345 static void bcm_tx_start_timer(struct bcm_op *op) 346 { 347 if (op->kt_ival1.tv64 && op->count) 348 hrtimer_start(&op->timer, 349 ktime_add(ktime_get(), op->kt_ival1), 350 HRTIMER_MODE_ABS); 351 else if (op->kt_ival2.tv64) 352 hrtimer_start(&op->timer, 353 ktime_add(ktime_get(), op->kt_ival2), 354 HRTIMER_MODE_ABS); 355 } 356 357 static void bcm_tx_timeout_tsklet(unsigned long data) 358 { 359 struct bcm_op *op = (struct bcm_op *)data; 360 struct bcm_msg_head msg_head; 361 362 if (op->kt_ival1.tv64 && (op->count > 0)) { 363 364 op->count--; 365 if (!op->count && (op->flags & TX_COUNTEVT)) { 366 367 /* create notification to user */ 368 msg_head.opcode = TX_EXPIRED; 369 msg_head.flags = op->flags; 370 msg_head.count = op->count; 371 msg_head.ival1 = op->ival1; 372 msg_head.ival2 = op->ival2; 373 msg_head.can_id = op->can_id; 374 msg_head.nframes = 0; 375 376 bcm_send_to_user(op, &msg_head, NULL, 0); 377 } 378 bcm_can_tx(op); 379 380 } else if (op->kt_ival2.tv64) 381 bcm_can_tx(op); 382 383 bcm_tx_start_timer(op); 384 } 385 386 /* 387 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions 388 */ 389 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 390 { 391 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 392 393 tasklet_schedule(&op->tsklet); 394 395 return HRTIMER_NORESTART; 396 } 397 398 /* 399 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 400 */ 401 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data) 402 { 403 struct bcm_msg_head head; 404 405 /* update statistics */ 406 op->frames_filtered++; 407 408 /* prevent statistics overflow */ 409 if (op->frames_filtered > ULONG_MAX/100) 410 op->frames_filtered = op->frames_abs = 0; 411 412 /* this element is not throttled anymore */ 413 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV); 414 415 head.opcode = RX_CHANGED; 416 head.flags = op->flags; 417 head.count = op->count; 418 head.ival1 = op->ival1; 419 head.ival2 = op->ival2; 420 head.can_id = op->can_id; 421 head.nframes = 1; 422 423 bcm_send_to_user(op, &head, data, 1); 424 } 425 426 /* 427 * bcm_rx_update_and_send - process a detected relevant receive content change 428 * 1. update the last received data 429 * 2. send a notification to the user (if possible) 430 */ 431 static void bcm_rx_update_and_send(struct bcm_op *op, 432 struct can_frame *lastdata, 433 const struct can_frame *rxdata) 434 { 435 memcpy(lastdata, rxdata, CFSIZ); 436 437 /* mark as used and throttled by default */ 438 lastdata->can_dlc |= (RX_RECV|RX_THR); 439 440 /* throtteling mode inactive ? */ 441 if (!op->kt_ival2.tv64) { 442 /* send RX_CHANGED to the user immediately */ 443 bcm_rx_changed(op, lastdata); 444 return; 445 } 446 447 /* with active throttling timer we are just done here */ 448 if (hrtimer_active(&op->thrtimer)) 449 return; 450 451 /* first receiption with enabled throttling mode */ 452 if (!op->kt_lastmsg.tv64) 453 goto rx_changed_settime; 454 455 /* got a second frame inside a potential throttle period? */ 456 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 457 ktime_to_us(op->kt_ival2)) { 458 /* do not send the saved data - only start throttle timer */ 459 hrtimer_start(&op->thrtimer, 460 ktime_add(op->kt_lastmsg, op->kt_ival2), 461 HRTIMER_MODE_ABS); 462 return; 463 } 464 465 /* the gap was that big, that throttling was not needed here */ 466 rx_changed_settime: 467 bcm_rx_changed(op, lastdata); 468 op->kt_lastmsg = ktime_get(); 469 } 470 471 /* 472 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 473 * received data stored in op->last_frames[] 474 */ 475 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 476 const struct can_frame *rxdata) 477 { 478 /* 479 * no one uses the MSBs of can_dlc for comparation, 480 * so we use it here to detect the first time of reception 481 */ 482 483 if (!(op->last_frames[index].can_dlc & RX_RECV)) { 484 /* received data for the first time => send update to user */ 485 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata); 486 return; 487 } 488 489 /* do a real check in can_frame data section */ 490 491 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) != 492 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) { 493 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata); 494 return; 495 } 496 497 if (op->flags & RX_CHECK_DLC) { 498 /* do a real check in can_frame dlc */ 499 if (rxdata->can_dlc != (op->last_frames[index].can_dlc & 500 BCM_CAN_DLC_MASK)) { 501 bcm_rx_update_and_send(op, &op->last_frames[index], 502 rxdata); 503 return; 504 } 505 } 506 } 507 508 /* 509 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption 510 */ 511 static void bcm_rx_starttimer(struct bcm_op *op) 512 { 513 if (op->flags & RX_NO_AUTOTIMER) 514 return; 515 516 if (op->kt_ival1.tv64) 517 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); 518 } 519 520 static void bcm_rx_timeout_tsklet(unsigned long data) 521 { 522 struct bcm_op *op = (struct bcm_op *)data; 523 struct bcm_msg_head msg_head; 524 525 /* create notification to user */ 526 msg_head.opcode = RX_TIMEOUT; 527 msg_head.flags = op->flags; 528 msg_head.count = op->count; 529 msg_head.ival1 = op->ival1; 530 msg_head.ival2 = op->ival2; 531 msg_head.can_id = op->can_id; 532 msg_head.nframes = 0; 533 534 bcm_send_to_user(op, &msg_head, NULL, 0); 535 } 536 537 /* 538 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out 539 */ 540 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 541 { 542 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 543 544 /* schedule before NET_RX_SOFTIRQ */ 545 tasklet_hi_schedule(&op->tsklet); 546 547 /* no restart of the timer is done here! */ 548 549 /* if user wants to be informed, when cyclic CAN-Messages come back */ 550 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 551 /* clear received can_frames to indicate 'nothing received' */ 552 memset(op->last_frames, 0, op->nframes * CFSIZ); 553 } 554 555 return HRTIMER_NORESTART; 556 } 557 558 /* 559 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 560 */ 561 static inline int bcm_rx_do_flush(struct bcm_op *op, int update, 562 unsigned int index) 563 { 564 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) { 565 if (update) 566 bcm_rx_changed(op, &op->last_frames[index]); 567 return 1; 568 } 569 return 0; 570 } 571 572 /* 573 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 574 * 575 * update == 0 : just check if throttled data is available (any irq context) 576 * update == 1 : check and send throttled data to userspace (soft_irq context) 577 */ 578 static int bcm_rx_thr_flush(struct bcm_op *op, int update) 579 { 580 int updated = 0; 581 582 if (op->nframes > 1) { 583 unsigned int i; 584 585 /* for MUX filter we start at index 1 */ 586 for (i = 1; i < op->nframes; i++) 587 updated += bcm_rx_do_flush(op, update, i); 588 589 } else { 590 /* for RX_FILTER_ID and simple filter */ 591 updated += bcm_rx_do_flush(op, update, 0); 592 } 593 594 return updated; 595 } 596 597 static void bcm_rx_thr_tsklet(unsigned long data) 598 { 599 struct bcm_op *op = (struct bcm_op *)data; 600 601 /* push the changed data to the userspace */ 602 bcm_rx_thr_flush(op, 1); 603 } 604 605 /* 606 * bcm_rx_thr_handler - the time for blocked content updates is over now: 607 * Check for throttled data and send it to the userspace 608 */ 609 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 610 { 611 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 612 613 tasklet_schedule(&op->thrtsklet); 614 615 if (bcm_rx_thr_flush(op, 0)) { 616 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); 617 return HRTIMER_RESTART; 618 } else { 619 /* rearm throttle handling */ 620 op->kt_lastmsg = ktime_set(0, 0); 621 return HRTIMER_NORESTART; 622 } 623 } 624 625 /* 626 * bcm_rx_handler - handle a CAN frame receiption 627 */ 628 static void bcm_rx_handler(struct sk_buff *skb, void *data) 629 { 630 struct bcm_op *op = (struct bcm_op *)data; 631 const struct can_frame *rxframe = (struct can_frame *)skb->data; 632 unsigned int i; 633 634 /* disable timeout */ 635 hrtimer_cancel(&op->timer); 636 637 if (op->can_id != rxframe->can_id) 638 return; 639 640 /* save rx timestamp */ 641 op->rx_stamp = skb->tstamp; 642 /* save originator for recvfrom() */ 643 op->rx_ifindex = skb->dev->ifindex; 644 /* update statistics */ 645 op->frames_abs++; 646 647 if (op->flags & RX_RTR_FRAME) { 648 /* send reply for RTR-request (placed in op->frames[0]) */ 649 bcm_can_tx(op); 650 return; 651 } 652 653 if (op->flags & RX_FILTER_ID) { 654 /* the easiest case */ 655 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe); 656 goto rx_starttimer; 657 } 658 659 if (op->nframes == 1) { 660 /* simple compare with index 0 */ 661 bcm_rx_cmp_to_index(op, 0, rxframe); 662 goto rx_starttimer; 663 } 664 665 if (op->nframes > 1) { 666 /* 667 * multiplex compare 668 * 669 * find the first multiplex mask that fits. 670 * Remark: The MUX-mask is stored in index 0 671 */ 672 673 for (i = 1; i < op->nframes; i++) { 674 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) == 675 (GET_U64(&op->frames[0]) & 676 GET_U64(&op->frames[i]))) { 677 bcm_rx_cmp_to_index(op, i, rxframe); 678 break; 679 } 680 } 681 } 682 683 rx_starttimer: 684 bcm_rx_starttimer(op); 685 } 686 687 /* 688 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 689 */ 690 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id, 691 int ifindex) 692 { 693 struct bcm_op *op; 694 695 list_for_each_entry(op, ops, list) { 696 if ((op->can_id == can_id) && (op->ifindex == ifindex)) 697 return op; 698 } 699 700 return NULL; 701 } 702 703 static void bcm_remove_op(struct bcm_op *op) 704 { 705 hrtimer_cancel(&op->timer); 706 hrtimer_cancel(&op->thrtimer); 707 708 if (op->tsklet.func) 709 tasklet_kill(&op->tsklet); 710 711 if (op->thrtsklet.func) 712 tasklet_kill(&op->thrtsklet); 713 714 if ((op->frames) && (op->frames != &op->sframe)) 715 kfree(op->frames); 716 717 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 718 kfree(op->last_frames); 719 720 kfree(op); 721 } 722 723 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 724 { 725 if (op->rx_reg_dev == dev) { 726 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id), 727 bcm_rx_handler, op); 728 729 /* mark as removed subscription */ 730 op->rx_reg_dev = NULL; 731 } else 732 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 733 "mismatch %p %p\n", op->rx_reg_dev, dev); 734 } 735 736 /* 737 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 738 */ 739 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex) 740 { 741 struct bcm_op *op, *n; 742 743 list_for_each_entry_safe(op, n, ops, list) { 744 if ((op->can_id == can_id) && (op->ifindex == ifindex)) { 745 746 /* 747 * Don't care if we're bound or not (due to netdev 748 * problems) can_rx_unregister() is always a save 749 * thing to do here. 750 */ 751 if (op->ifindex) { 752 /* 753 * Only remove subscriptions that had not 754 * been removed due to NETDEV_UNREGISTER 755 * in bcm_notifier() 756 */ 757 if (op->rx_reg_dev) { 758 struct net_device *dev; 759 760 dev = dev_get_by_index(&init_net, 761 op->ifindex); 762 if (dev) { 763 bcm_rx_unreg(dev, op); 764 dev_put(dev); 765 } 766 } 767 } else 768 can_rx_unregister(NULL, op->can_id, 769 REGMASK(op->can_id), 770 bcm_rx_handler, op); 771 772 list_del(&op->list); 773 bcm_remove_op(op); 774 return 1; /* done */ 775 } 776 } 777 778 return 0; /* not found */ 779 } 780 781 /* 782 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 783 */ 784 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex) 785 { 786 struct bcm_op *op, *n; 787 788 list_for_each_entry_safe(op, n, ops, list) { 789 if ((op->can_id == can_id) && (op->ifindex == ifindex)) { 790 list_del(&op->list); 791 bcm_remove_op(op); 792 return 1; /* done */ 793 } 794 } 795 796 return 0; /* not found */ 797 } 798 799 /* 800 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 801 */ 802 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 803 int ifindex) 804 { 805 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex); 806 807 if (!op) 808 return -EINVAL; 809 810 /* put current values into msg_head */ 811 msg_head->flags = op->flags; 812 msg_head->count = op->count; 813 msg_head->ival1 = op->ival1; 814 msg_head->ival2 = op->ival2; 815 msg_head->nframes = op->nframes; 816 817 bcm_send_to_user(op, msg_head, op->frames, 0); 818 819 return MHSIZ; 820 } 821 822 /* 823 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 824 */ 825 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 826 int ifindex, struct sock *sk) 827 { 828 struct bcm_sock *bo = bcm_sk(sk); 829 struct bcm_op *op; 830 unsigned int i; 831 int err; 832 833 /* we need a real device to send frames */ 834 if (!ifindex) 835 return -ENODEV; 836 837 /* check nframes boundaries - we need at least one can_frame */ 838 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 839 return -EINVAL; 840 841 /* check the given can_id */ 842 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex); 843 844 if (op) { 845 /* update existing BCM operation */ 846 847 /* 848 * Do we need more space for the can_frames than currently 849 * allocated? -> This is a _really_ unusual use-case and 850 * therefore (complexity / locking) it is not supported. 851 */ 852 if (msg_head->nframes > op->nframes) 853 return -E2BIG; 854 855 /* update can_frames content */ 856 for (i = 0; i < msg_head->nframes; i++) { 857 err = memcpy_fromiovec((u8 *)&op->frames[i], 858 msg->msg_iov, CFSIZ); 859 860 if (op->frames[i].can_dlc > 8) 861 err = -EINVAL; 862 863 if (err < 0) 864 return err; 865 866 if (msg_head->flags & TX_CP_CAN_ID) { 867 /* copy can_id into frame */ 868 op->frames[i].can_id = msg_head->can_id; 869 } 870 } 871 872 } else { 873 /* insert new BCM operation for the given can_id */ 874 875 op = kzalloc(OPSIZ, GFP_KERNEL); 876 if (!op) 877 return -ENOMEM; 878 879 op->can_id = msg_head->can_id; 880 881 /* create array for can_frames and copy the data */ 882 if (msg_head->nframes > 1) { 883 op->frames = kmalloc(msg_head->nframes * CFSIZ, 884 GFP_KERNEL); 885 if (!op->frames) { 886 kfree(op); 887 return -ENOMEM; 888 } 889 } else 890 op->frames = &op->sframe; 891 892 for (i = 0; i < msg_head->nframes; i++) { 893 err = memcpy_fromiovec((u8 *)&op->frames[i], 894 msg->msg_iov, CFSIZ); 895 896 if (op->frames[i].can_dlc > 8) 897 err = -EINVAL; 898 899 if (err < 0) { 900 if (op->frames != &op->sframe) 901 kfree(op->frames); 902 kfree(op); 903 return err; 904 } 905 906 if (msg_head->flags & TX_CP_CAN_ID) { 907 /* copy can_id into frame */ 908 op->frames[i].can_id = msg_head->can_id; 909 } 910 } 911 912 /* tx_ops never compare with previous received messages */ 913 op->last_frames = NULL; 914 915 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 916 op->sk = sk; 917 op->ifindex = ifindex; 918 919 /* initialize uninitialized (kzalloc) structure */ 920 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 921 op->timer.function = bcm_tx_timeout_handler; 922 923 /* initialize tasklet for tx countevent notification */ 924 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, 925 (unsigned long) op); 926 927 /* currently unused in tx_ops */ 928 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 929 930 /* add this bcm_op to the list of the tx_ops */ 931 list_add(&op->list, &bo->tx_ops); 932 933 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 934 935 if (op->nframes != msg_head->nframes) { 936 op->nframes = msg_head->nframes; 937 /* start multiple frame transmission with index 0 */ 938 op->currframe = 0; 939 } 940 941 /* check flags */ 942 943 op->flags = msg_head->flags; 944 945 if (op->flags & TX_RESET_MULTI_IDX) { 946 /* start multiple frame transmission with index 0 */ 947 op->currframe = 0; 948 } 949 950 if (op->flags & SETTIMER) { 951 /* set timer values */ 952 op->count = msg_head->count; 953 op->ival1 = msg_head->ival1; 954 op->ival2 = msg_head->ival2; 955 op->kt_ival1 = timeval_to_ktime(msg_head->ival1); 956 op->kt_ival2 = timeval_to_ktime(msg_head->ival2); 957 958 /* disable an active timer due to zero values? */ 959 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64) 960 hrtimer_cancel(&op->timer); 961 } 962 963 if (op->flags & STARTTIMER) { 964 hrtimer_cancel(&op->timer); 965 /* spec: send can_frame when starting timer */ 966 op->flags |= TX_ANNOUNCE; 967 } 968 969 if (op->flags & TX_ANNOUNCE) { 970 bcm_can_tx(op); 971 if (op->count) 972 op->count--; 973 } 974 975 if (op->flags & STARTTIMER) 976 bcm_tx_start_timer(op); 977 978 return msg_head->nframes * CFSIZ + MHSIZ; 979 } 980 981 /* 982 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 983 */ 984 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 985 int ifindex, struct sock *sk) 986 { 987 struct bcm_sock *bo = bcm_sk(sk); 988 struct bcm_op *op; 989 int do_rx_register; 990 int err = 0; 991 992 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 993 /* be robust against wrong usage ... */ 994 msg_head->flags |= RX_FILTER_ID; 995 /* ignore trailing garbage */ 996 msg_head->nframes = 0; 997 } 998 999 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1000 if (msg_head->nframes > MAX_NFRAMES + 1) 1001 return -EINVAL; 1002 1003 if ((msg_head->flags & RX_RTR_FRAME) && 1004 ((msg_head->nframes != 1) || 1005 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1006 return -EINVAL; 1007 1008 /* check the given can_id */ 1009 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex); 1010 if (op) { 1011 /* update existing BCM operation */ 1012 1013 /* 1014 * Do we need more space for the can_frames than currently 1015 * allocated? -> This is a _really_ unusual use-case and 1016 * therefore (complexity / locking) it is not supported. 1017 */ 1018 if (msg_head->nframes > op->nframes) 1019 return -E2BIG; 1020 1021 if (msg_head->nframes) { 1022 /* update can_frames content */ 1023 err = memcpy_fromiovec((u8 *)op->frames, 1024 msg->msg_iov, 1025 msg_head->nframes * CFSIZ); 1026 if (err < 0) 1027 return err; 1028 1029 /* clear last_frames to indicate 'nothing received' */ 1030 memset(op->last_frames, 0, msg_head->nframes * CFSIZ); 1031 } 1032 1033 op->nframes = msg_head->nframes; 1034 1035 /* Only an update -> do not call can_rx_register() */ 1036 do_rx_register = 0; 1037 1038 } else { 1039 /* insert new BCM operation for the given can_id */ 1040 op = kzalloc(OPSIZ, GFP_KERNEL); 1041 if (!op) 1042 return -ENOMEM; 1043 1044 op->can_id = msg_head->can_id; 1045 op->nframes = msg_head->nframes; 1046 1047 if (msg_head->nframes > 1) { 1048 /* create array for can_frames and copy the data */ 1049 op->frames = kmalloc(msg_head->nframes * CFSIZ, 1050 GFP_KERNEL); 1051 if (!op->frames) { 1052 kfree(op); 1053 return -ENOMEM; 1054 } 1055 1056 /* create and init array for received can_frames */ 1057 op->last_frames = kzalloc(msg_head->nframes * CFSIZ, 1058 GFP_KERNEL); 1059 if (!op->last_frames) { 1060 kfree(op->frames); 1061 kfree(op); 1062 return -ENOMEM; 1063 } 1064 1065 } else { 1066 op->frames = &op->sframe; 1067 op->last_frames = &op->last_sframe; 1068 } 1069 1070 if (msg_head->nframes) { 1071 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov, 1072 msg_head->nframes * CFSIZ); 1073 if (err < 0) { 1074 if (op->frames != &op->sframe) 1075 kfree(op->frames); 1076 if (op->last_frames != &op->last_sframe) 1077 kfree(op->last_frames); 1078 kfree(op); 1079 return err; 1080 } 1081 } 1082 1083 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1084 op->sk = sk; 1085 op->ifindex = ifindex; 1086 1087 /* ifindex for timeout events w/o previous frame reception */ 1088 op->rx_ifindex = ifindex; 1089 1090 /* initialize uninitialized (kzalloc) structure */ 1091 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1092 op->timer.function = bcm_rx_timeout_handler; 1093 1094 /* initialize tasklet for rx timeout notification */ 1095 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, 1096 (unsigned long) op); 1097 1098 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1099 op->thrtimer.function = bcm_rx_thr_handler; 1100 1101 /* initialize tasklet for rx throttle handling */ 1102 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, 1103 (unsigned long) op); 1104 1105 /* add this bcm_op to the list of the rx_ops */ 1106 list_add(&op->list, &bo->rx_ops); 1107 1108 /* call can_rx_register() */ 1109 do_rx_register = 1; 1110 1111 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1112 1113 /* check flags */ 1114 op->flags = msg_head->flags; 1115 1116 if (op->flags & RX_RTR_FRAME) { 1117 1118 /* no timers in RTR-mode */ 1119 hrtimer_cancel(&op->thrtimer); 1120 hrtimer_cancel(&op->timer); 1121 1122 /* 1123 * funny feature in RX(!)_SETUP only for RTR-mode: 1124 * copy can_id into frame BUT without RTR-flag to 1125 * prevent a full-load-loopback-test ... ;-] 1126 */ 1127 if ((op->flags & TX_CP_CAN_ID) || 1128 (op->frames[0].can_id == op->can_id)) 1129 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG; 1130 1131 } else { 1132 if (op->flags & SETTIMER) { 1133 1134 /* set timer value */ 1135 op->ival1 = msg_head->ival1; 1136 op->ival2 = msg_head->ival2; 1137 op->kt_ival1 = timeval_to_ktime(msg_head->ival1); 1138 op->kt_ival2 = timeval_to_ktime(msg_head->ival2); 1139 1140 /* disable an active timer due to zero value? */ 1141 if (!op->kt_ival1.tv64) 1142 hrtimer_cancel(&op->timer); 1143 1144 /* 1145 * In any case cancel the throttle timer, flush 1146 * potentially blocked msgs and reset throttle handling 1147 */ 1148 op->kt_lastmsg = ktime_set(0, 0); 1149 hrtimer_cancel(&op->thrtimer); 1150 bcm_rx_thr_flush(op, 1); 1151 } 1152 1153 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64) 1154 hrtimer_start(&op->timer, op->kt_ival1, 1155 HRTIMER_MODE_REL); 1156 } 1157 1158 /* now we can register for can_ids, if we added a new bcm_op */ 1159 if (do_rx_register) { 1160 if (ifindex) { 1161 struct net_device *dev; 1162 1163 dev = dev_get_by_index(&init_net, ifindex); 1164 if (dev) { 1165 err = can_rx_register(dev, op->can_id, 1166 REGMASK(op->can_id), 1167 bcm_rx_handler, op, 1168 "bcm"); 1169 1170 op->rx_reg_dev = dev; 1171 dev_put(dev); 1172 } 1173 1174 } else 1175 err = can_rx_register(NULL, op->can_id, 1176 REGMASK(op->can_id), 1177 bcm_rx_handler, op, "bcm"); 1178 if (err) { 1179 /* this bcm rx op is broken -> remove it */ 1180 list_del(&op->list); 1181 bcm_remove_op(op); 1182 return err; 1183 } 1184 } 1185 1186 return msg_head->nframes * CFSIZ + MHSIZ; 1187 } 1188 1189 /* 1190 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1191 */ 1192 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk) 1193 { 1194 struct sk_buff *skb; 1195 struct net_device *dev; 1196 int err; 1197 1198 /* we need a real device to send frames */ 1199 if (!ifindex) 1200 return -ENODEV; 1201 1202 skb = alloc_skb(CFSIZ, GFP_KERNEL); 1203 1204 if (!skb) 1205 return -ENOMEM; 1206 1207 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ); 1208 if (err < 0) { 1209 kfree_skb(skb); 1210 return err; 1211 } 1212 1213 dev = dev_get_by_index(&init_net, ifindex); 1214 if (!dev) { 1215 kfree_skb(skb); 1216 return -ENODEV; 1217 } 1218 1219 skb->dev = dev; 1220 skb->sk = sk; 1221 err = can_send(skb, 1); /* send with loopback */ 1222 dev_put(dev); 1223 1224 if (err) 1225 return err; 1226 1227 return CFSIZ + MHSIZ; 1228 } 1229 1230 /* 1231 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1232 */ 1233 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock, 1234 struct msghdr *msg, size_t size) 1235 { 1236 struct sock *sk = sock->sk; 1237 struct bcm_sock *bo = bcm_sk(sk); 1238 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1239 struct bcm_msg_head msg_head; 1240 int ret; /* read bytes or error codes as return value */ 1241 1242 if (!bo->bound) 1243 return -ENOTCONN; 1244 1245 /* check for valid message length from userspace */ 1246 if (size < MHSIZ || (size - MHSIZ) % CFSIZ) 1247 return -EINVAL; 1248 1249 /* check for alternative ifindex for this bcm_op */ 1250 1251 if (!ifindex && msg->msg_name) { 1252 /* no bound device as default => check msg_name */ 1253 struct sockaddr_can *addr = 1254 (struct sockaddr_can *)msg->msg_name; 1255 1256 if (msg->msg_namelen < sizeof(*addr)) 1257 return -EINVAL; 1258 1259 if (addr->can_family != AF_CAN) 1260 return -EINVAL; 1261 1262 /* ifindex from sendto() */ 1263 ifindex = addr->can_ifindex; 1264 1265 if (ifindex) { 1266 struct net_device *dev; 1267 1268 dev = dev_get_by_index(&init_net, ifindex); 1269 if (!dev) 1270 return -ENODEV; 1271 1272 if (dev->type != ARPHRD_CAN) { 1273 dev_put(dev); 1274 return -ENODEV; 1275 } 1276 1277 dev_put(dev); 1278 } 1279 } 1280 1281 /* read message head information */ 1282 1283 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ); 1284 if (ret < 0) 1285 return ret; 1286 1287 lock_sock(sk); 1288 1289 switch (msg_head.opcode) { 1290 1291 case TX_SETUP: 1292 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1293 break; 1294 1295 case RX_SETUP: 1296 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1297 break; 1298 1299 case TX_DELETE: 1300 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex)) 1301 ret = MHSIZ; 1302 else 1303 ret = -EINVAL; 1304 break; 1305 1306 case RX_DELETE: 1307 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex)) 1308 ret = MHSIZ; 1309 else 1310 ret = -EINVAL; 1311 break; 1312 1313 case TX_READ: 1314 /* reuse msg_head for the reply to TX_READ */ 1315 msg_head.opcode = TX_STATUS; 1316 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1317 break; 1318 1319 case RX_READ: 1320 /* reuse msg_head for the reply to RX_READ */ 1321 msg_head.opcode = RX_STATUS; 1322 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1323 break; 1324 1325 case TX_SEND: 1326 /* we need exactly one can_frame behind the msg head */ 1327 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ)) 1328 ret = -EINVAL; 1329 else 1330 ret = bcm_tx_send(msg, ifindex, sk); 1331 break; 1332 1333 default: 1334 ret = -EINVAL; 1335 break; 1336 } 1337 1338 release_sock(sk); 1339 1340 return ret; 1341 } 1342 1343 /* 1344 * notification handler for netdevice status changes 1345 */ 1346 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1347 void *data) 1348 { 1349 struct net_device *dev = (struct net_device *)data; 1350 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); 1351 struct sock *sk = &bo->sk; 1352 struct bcm_op *op; 1353 int notify_enodev = 0; 1354 1355 if (!net_eq(dev_net(dev), &init_net)) 1356 return NOTIFY_DONE; 1357 1358 if (dev->type != ARPHRD_CAN) 1359 return NOTIFY_DONE; 1360 1361 switch (msg) { 1362 1363 case NETDEV_UNREGISTER: 1364 lock_sock(sk); 1365 1366 /* remove device specific receive entries */ 1367 list_for_each_entry(op, &bo->rx_ops, list) 1368 if (op->rx_reg_dev == dev) 1369 bcm_rx_unreg(dev, op); 1370 1371 /* remove device reference, if this is our bound device */ 1372 if (bo->bound && bo->ifindex == dev->ifindex) { 1373 bo->bound = 0; 1374 bo->ifindex = 0; 1375 notify_enodev = 1; 1376 } 1377 1378 release_sock(sk); 1379 1380 if (notify_enodev) { 1381 sk->sk_err = ENODEV; 1382 if (!sock_flag(sk, SOCK_DEAD)) 1383 sk->sk_error_report(sk); 1384 } 1385 break; 1386 1387 case NETDEV_DOWN: 1388 if (bo->bound && bo->ifindex == dev->ifindex) { 1389 sk->sk_err = ENETDOWN; 1390 if (!sock_flag(sk, SOCK_DEAD)) 1391 sk->sk_error_report(sk); 1392 } 1393 } 1394 1395 return NOTIFY_DONE; 1396 } 1397 1398 /* 1399 * initial settings for all BCM sockets to be set at socket creation time 1400 */ 1401 static int bcm_init(struct sock *sk) 1402 { 1403 struct bcm_sock *bo = bcm_sk(sk); 1404 1405 bo->bound = 0; 1406 bo->ifindex = 0; 1407 bo->dropped_usr_msgs = 0; 1408 bo->bcm_proc_read = NULL; 1409 1410 INIT_LIST_HEAD(&bo->tx_ops); 1411 INIT_LIST_HEAD(&bo->rx_ops); 1412 1413 /* set notifier */ 1414 bo->notifier.notifier_call = bcm_notifier; 1415 1416 register_netdevice_notifier(&bo->notifier); 1417 1418 return 0; 1419 } 1420 1421 /* 1422 * standard socket functions 1423 */ 1424 static int bcm_release(struct socket *sock) 1425 { 1426 struct sock *sk = sock->sk; 1427 struct bcm_sock *bo; 1428 struct bcm_op *op, *next; 1429 1430 if (sk == NULL) 1431 return 0; 1432 1433 bo = bcm_sk(sk); 1434 1435 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1436 1437 unregister_netdevice_notifier(&bo->notifier); 1438 1439 lock_sock(sk); 1440 1441 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1442 bcm_remove_op(op); 1443 1444 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1445 /* 1446 * Don't care if we're bound or not (due to netdev problems) 1447 * can_rx_unregister() is always a save thing to do here. 1448 */ 1449 if (op->ifindex) { 1450 /* 1451 * Only remove subscriptions that had not 1452 * been removed due to NETDEV_UNREGISTER 1453 * in bcm_notifier() 1454 */ 1455 if (op->rx_reg_dev) { 1456 struct net_device *dev; 1457 1458 dev = dev_get_by_index(&init_net, op->ifindex); 1459 if (dev) { 1460 bcm_rx_unreg(dev, op); 1461 dev_put(dev); 1462 } 1463 } 1464 } else 1465 can_rx_unregister(NULL, op->can_id, 1466 REGMASK(op->can_id), 1467 bcm_rx_handler, op); 1468 1469 bcm_remove_op(op); 1470 } 1471 1472 /* remove procfs entry */ 1473 if (proc_dir && bo->bcm_proc_read) 1474 remove_proc_entry(bo->procname, proc_dir); 1475 1476 /* remove device reference */ 1477 if (bo->bound) { 1478 bo->bound = 0; 1479 bo->ifindex = 0; 1480 } 1481 1482 sock_orphan(sk); 1483 sock->sk = NULL; 1484 1485 release_sock(sk); 1486 sock_put(sk); 1487 1488 return 0; 1489 } 1490 1491 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1492 int flags) 1493 { 1494 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1495 struct sock *sk = sock->sk; 1496 struct bcm_sock *bo = bcm_sk(sk); 1497 1498 if (len < sizeof(*addr)) 1499 return -EINVAL; 1500 1501 if (bo->bound) 1502 return -EISCONN; 1503 1504 /* bind a device to this socket */ 1505 if (addr->can_ifindex) { 1506 struct net_device *dev; 1507 1508 dev = dev_get_by_index(&init_net, addr->can_ifindex); 1509 if (!dev) 1510 return -ENODEV; 1511 1512 if (dev->type != ARPHRD_CAN) { 1513 dev_put(dev); 1514 return -ENODEV; 1515 } 1516 1517 bo->ifindex = dev->ifindex; 1518 dev_put(dev); 1519 1520 } else { 1521 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1522 bo->ifindex = 0; 1523 } 1524 1525 bo->bound = 1; 1526 1527 if (proc_dir) { 1528 /* unique socket address as filename */ 1529 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1530 bo->bcm_proc_read = proc_create_data(bo->procname, 0644, 1531 proc_dir, 1532 &bcm_proc_fops, sk); 1533 } 1534 1535 return 0; 1536 } 1537 1538 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock, 1539 struct msghdr *msg, size_t size, int flags) 1540 { 1541 struct sock *sk = sock->sk; 1542 struct sk_buff *skb; 1543 int error = 0; 1544 int noblock; 1545 int err; 1546 1547 noblock = flags & MSG_DONTWAIT; 1548 flags &= ~MSG_DONTWAIT; 1549 skb = skb_recv_datagram(sk, flags, noblock, &error); 1550 if (!skb) 1551 return error; 1552 1553 if (skb->len < size) 1554 size = skb->len; 1555 1556 err = memcpy_toiovec(msg->msg_iov, skb->data, size); 1557 if (err < 0) { 1558 skb_free_datagram(sk, skb); 1559 return err; 1560 } 1561 1562 sock_recv_ts_and_drops(msg, sk, skb); 1563 1564 if (msg->msg_name) { 1565 msg->msg_namelen = sizeof(struct sockaddr_can); 1566 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1567 } 1568 1569 skb_free_datagram(sk, skb); 1570 1571 return size; 1572 } 1573 1574 static const struct proto_ops bcm_ops = { 1575 .family = PF_CAN, 1576 .release = bcm_release, 1577 .bind = sock_no_bind, 1578 .connect = bcm_connect, 1579 .socketpair = sock_no_socketpair, 1580 .accept = sock_no_accept, 1581 .getname = sock_no_getname, 1582 .poll = datagram_poll, 1583 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ 1584 .listen = sock_no_listen, 1585 .shutdown = sock_no_shutdown, 1586 .setsockopt = sock_no_setsockopt, 1587 .getsockopt = sock_no_getsockopt, 1588 .sendmsg = bcm_sendmsg, 1589 .recvmsg = bcm_recvmsg, 1590 .mmap = sock_no_mmap, 1591 .sendpage = sock_no_sendpage, 1592 }; 1593 1594 static struct proto bcm_proto __read_mostly = { 1595 .name = "CAN_BCM", 1596 .owner = THIS_MODULE, 1597 .obj_size = sizeof(struct bcm_sock), 1598 .init = bcm_init, 1599 }; 1600 1601 static const struct can_proto bcm_can_proto = { 1602 .type = SOCK_DGRAM, 1603 .protocol = CAN_BCM, 1604 .ops = &bcm_ops, 1605 .prot = &bcm_proto, 1606 }; 1607 1608 static int __init bcm_module_init(void) 1609 { 1610 int err; 1611 1612 printk(banner); 1613 1614 err = can_proto_register(&bcm_can_proto); 1615 if (err < 0) { 1616 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1617 return err; 1618 } 1619 1620 /* create /proc/net/can-bcm directory */ 1621 proc_dir = proc_mkdir("can-bcm", init_net.proc_net); 1622 return 0; 1623 } 1624 1625 static void __exit bcm_module_exit(void) 1626 { 1627 can_proto_unregister(&bcm_can_proto); 1628 1629 if (proc_dir) 1630 proc_net_remove(&init_net, "can-bcm"); 1631 } 1632 1633 module_init(bcm_module_init); 1634 module_exit(bcm_module_exit); 1635