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 "20161123" 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 /* void pointers to arrays of struct can[fd]_frame */ 113 void *frames; 114 void *last_frames; 115 struct canfd_frame sframe; 116 struct canfd_frame last_sframe; 117 struct sock *sk; 118 struct net_device *rx_reg_dev; 119 }; 120 121 static struct proc_dir_entry *proc_dir; 122 123 struct bcm_sock { 124 struct sock sk; 125 int bound; 126 int ifindex; 127 struct notifier_block notifier; 128 struct list_head rx_ops; 129 struct list_head tx_ops; 130 unsigned long dropped_usr_msgs; 131 struct proc_dir_entry *bcm_proc_read; 132 char procname [32]; /* inode number in decimal with \0 */ 133 }; 134 135 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 136 { 137 return (struct bcm_sock *)sk; 138 } 139 140 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 141 { 142 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 143 } 144 145 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 146 #define OPSIZ sizeof(struct bcm_op) 147 #define MHSIZ sizeof(struct bcm_msg_head) 148 149 /* 150 * procfs functions 151 */ 152 static char *bcm_proc_getifname(char *result, int ifindex) 153 { 154 struct net_device *dev; 155 156 if (!ifindex) 157 return "any"; 158 159 rcu_read_lock(); 160 dev = dev_get_by_index_rcu(&init_net, ifindex); 161 if (dev) 162 strcpy(result, dev->name); 163 else 164 strcpy(result, "???"); 165 rcu_read_unlock(); 166 167 return result; 168 } 169 170 static int bcm_proc_show(struct seq_file *m, void *v) 171 { 172 char ifname[IFNAMSIZ]; 173 struct sock *sk = (struct sock *)m->private; 174 struct bcm_sock *bo = bcm_sk(sk); 175 struct bcm_op *op; 176 177 seq_printf(m, ">>> socket %pK", sk->sk_socket); 178 seq_printf(m, " / sk %pK", sk); 179 seq_printf(m, " / bo %pK", bo); 180 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 181 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex)); 182 seq_printf(m, " <<<\n"); 183 184 list_for_each_entry(op, &bo->rx_ops, list) { 185 186 unsigned long reduction; 187 188 /* print only active entries & prevent division by zero */ 189 if (!op->frames_abs) 190 continue; 191 192 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 193 bcm_proc_getifname(ifname, op->ifindex)); 194 195 if (op->flags & CAN_FD_FRAME) 196 seq_printf(m, "(%u)", op->nframes); 197 else 198 seq_printf(m, "[%u]", op->nframes); 199 200 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 201 202 if (op->kt_ival1.tv64) 203 seq_printf(m, "timeo=%lld ", 204 (long long)ktime_to_us(op->kt_ival1)); 205 206 if (op->kt_ival2.tv64) 207 seq_printf(m, "thr=%lld ", 208 (long long)ktime_to_us(op->kt_ival2)); 209 210 seq_printf(m, "# recv %ld (%ld) => reduction: ", 211 op->frames_filtered, op->frames_abs); 212 213 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 214 215 seq_printf(m, "%s%ld%%\n", 216 (reduction == 100) ? "near " : "", reduction); 217 } 218 219 list_for_each_entry(op, &bo->tx_ops, list) { 220 221 seq_printf(m, "tx_op: %03X %s ", op->can_id, 222 bcm_proc_getifname(ifname, op->ifindex)); 223 224 if (op->flags & CAN_FD_FRAME) 225 seq_printf(m, "(%u) ", op->nframes); 226 else 227 seq_printf(m, "[%u] ", op->nframes); 228 229 if (op->kt_ival1.tv64) 230 seq_printf(m, "t1=%lld ", 231 (long long)ktime_to_us(op->kt_ival1)); 232 233 if (op->kt_ival2.tv64) 234 seq_printf(m, "t2=%lld ", 235 (long long)ktime_to_us(op->kt_ival2)); 236 237 seq_printf(m, "# sent %ld\n", op->frames_abs); 238 } 239 seq_putc(m, '\n'); 240 return 0; 241 } 242 243 static int bcm_proc_open(struct inode *inode, struct file *file) 244 { 245 return single_open(file, bcm_proc_show, PDE_DATA(inode)); 246 } 247 248 static const struct file_operations bcm_proc_fops = { 249 .owner = THIS_MODULE, 250 .open = bcm_proc_open, 251 .read = seq_read, 252 .llseek = seq_lseek, 253 .release = single_release, 254 }; 255 256 /* 257 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 258 * of the given bcm tx op 259 */ 260 static void bcm_can_tx(struct bcm_op *op) 261 { 262 struct sk_buff *skb; 263 struct net_device *dev; 264 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 265 266 /* no target device? => exit */ 267 if (!op->ifindex) 268 return; 269 270 dev = dev_get_by_index(&init_net, op->ifindex); 271 if (!dev) { 272 /* RFC: should this bcm_op remove itself here? */ 273 return; 274 } 275 276 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 277 if (!skb) 278 goto out; 279 280 can_skb_reserve(skb); 281 can_skb_prv(skb)->ifindex = dev->ifindex; 282 can_skb_prv(skb)->skbcnt = 0; 283 284 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz); 285 286 /* send with loopback */ 287 skb->dev = dev; 288 can_skb_set_owner(skb, op->sk); 289 can_send(skb, 1); 290 291 /* update statistics */ 292 op->currframe++; 293 op->frames_abs++; 294 295 /* reached last frame? */ 296 if (op->currframe >= op->nframes) 297 op->currframe = 0; 298 out: 299 dev_put(dev); 300 } 301 302 /* 303 * bcm_send_to_user - send a BCM message to the userspace 304 * (consisting of bcm_msg_head + x CAN frames) 305 */ 306 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 307 struct canfd_frame *frames, int has_timestamp) 308 { 309 struct sk_buff *skb; 310 struct canfd_frame *firstframe; 311 struct sockaddr_can *addr; 312 struct sock *sk = op->sk; 313 unsigned int datalen = head->nframes * op->cfsiz; 314 int err; 315 316 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 317 if (!skb) 318 return; 319 320 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head)); 321 322 if (head->nframes) { 323 /* CAN frames starting here */ 324 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 325 326 memcpy(skb_put(skb, datalen), frames, datalen); 327 328 /* 329 * the BCM uses the flags-element of the canfd_frame 330 * structure for internal purposes. This is only 331 * relevant for updates that are generated by the 332 * BCM, where nframes is 1 333 */ 334 if (head->nframes == 1) 335 firstframe->flags &= BCM_CAN_FLAGS_MASK; 336 } 337 338 if (has_timestamp) { 339 /* restore rx timestamp */ 340 skb->tstamp = op->rx_stamp; 341 } 342 343 /* 344 * Put the datagram to the queue so that bcm_recvmsg() can 345 * get it from there. We need to pass the interface index to 346 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 347 * containing the interface index. 348 */ 349 350 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 351 addr = (struct sockaddr_can *)skb->cb; 352 memset(addr, 0, sizeof(*addr)); 353 addr->can_family = AF_CAN; 354 addr->can_ifindex = op->rx_ifindex; 355 356 err = sock_queue_rcv_skb(sk, skb); 357 if (err < 0) { 358 struct bcm_sock *bo = bcm_sk(sk); 359 360 kfree_skb(skb); 361 /* don't care about overflows in this statistic */ 362 bo->dropped_usr_msgs++; 363 } 364 } 365 366 static void bcm_tx_start_timer(struct bcm_op *op) 367 { 368 if (op->kt_ival1.tv64 && op->count) 369 hrtimer_start(&op->timer, 370 ktime_add(ktime_get(), op->kt_ival1), 371 HRTIMER_MODE_ABS); 372 else if (op->kt_ival2.tv64) 373 hrtimer_start(&op->timer, 374 ktime_add(ktime_get(), op->kt_ival2), 375 HRTIMER_MODE_ABS); 376 } 377 378 static void bcm_tx_timeout_tsklet(unsigned long data) 379 { 380 struct bcm_op *op = (struct bcm_op *)data; 381 struct bcm_msg_head msg_head; 382 383 if (op->kt_ival1.tv64 && (op->count > 0)) { 384 385 op->count--; 386 if (!op->count && (op->flags & TX_COUNTEVT)) { 387 388 /* create notification to user */ 389 msg_head.opcode = TX_EXPIRED; 390 msg_head.flags = op->flags; 391 msg_head.count = op->count; 392 msg_head.ival1 = op->ival1; 393 msg_head.ival2 = op->ival2; 394 msg_head.can_id = op->can_id; 395 msg_head.nframes = 0; 396 397 bcm_send_to_user(op, &msg_head, NULL, 0); 398 } 399 bcm_can_tx(op); 400 401 } else if (op->kt_ival2.tv64) 402 bcm_can_tx(op); 403 404 bcm_tx_start_timer(op); 405 } 406 407 /* 408 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions 409 */ 410 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 411 { 412 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 413 414 tasklet_schedule(&op->tsklet); 415 416 return HRTIMER_NORESTART; 417 } 418 419 /* 420 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 421 */ 422 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 423 { 424 struct bcm_msg_head head; 425 426 /* update statistics */ 427 op->frames_filtered++; 428 429 /* prevent statistics overflow */ 430 if (op->frames_filtered > ULONG_MAX/100) 431 op->frames_filtered = op->frames_abs = 0; 432 433 /* this element is not throttled anymore */ 434 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 435 436 head.opcode = RX_CHANGED; 437 head.flags = op->flags; 438 head.count = op->count; 439 head.ival1 = op->ival1; 440 head.ival2 = op->ival2; 441 head.can_id = op->can_id; 442 head.nframes = 1; 443 444 bcm_send_to_user(op, &head, data, 1); 445 } 446 447 /* 448 * bcm_rx_update_and_send - process a detected relevant receive content change 449 * 1. update the last received data 450 * 2. send a notification to the user (if possible) 451 */ 452 static void bcm_rx_update_and_send(struct bcm_op *op, 453 struct canfd_frame *lastdata, 454 const struct canfd_frame *rxdata) 455 { 456 memcpy(lastdata, rxdata, op->cfsiz); 457 458 /* mark as used and throttled by default */ 459 lastdata->flags |= (RX_RECV|RX_THR); 460 461 /* throttling mode inactive ? */ 462 if (!op->kt_ival2.tv64) { 463 /* send RX_CHANGED to the user immediately */ 464 bcm_rx_changed(op, lastdata); 465 return; 466 } 467 468 /* with active throttling timer we are just done here */ 469 if (hrtimer_active(&op->thrtimer)) 470 return; 471 472 /* first reception with enabled throttling mode */ 473 if (!op->kt_lastmsg.tv64) 474 goto rx_changed_settime; 475 476 /* got a second frame inside a potential throttle period? */ 477 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 478 ktime_to_us(op->kt_ival2)) { 479 /* do not send the saved data - only start throttle timer */ 480 hrtimer_start(&op->thrtimer, 481 ktime_add(op->kt_lastmsg, op->kt_ival2), 482 HRTIMER_MODE_ABS); 483 return; 484 } 485 486 /* the gap was that big, that throttling was not needed here */ 487 rx_changed_settime: 488 bcm_rx_changed(op, lastdata); 489 op->kt_lastmsg = ktime_get(); 490 } 491 492 /* 493 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 494 * received data stored in op->last_frames[] 495 */ 496 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 497 const struct canfd_frame *rxdata) 498 { 499 struct canfd_frame *cf = op->frames + op->cfsiz * index; 500 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 501 int i; 502 503 /* 504 * no one uses the MSBs of flags for comparison, 505 * so we use it here to detect the first time of reception 506 */ 507 508 if (!(lcf->flags & RX_RECV)) { 509 /* received data for the first time => send update to user */ 510 bcm_rx_update_and_send(op, lcf, rxdata); 511 return; 512 } 513 514 /* do a real check in CAN frame data section */ 515 for (i = 0; i < rxdata->len; i += 8) { 516 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 517 (get_u64(cf, i) & get_u64(lcf, i))) { 518 bcm_rx_update_and_send(op, lcf, rxdata); 519 return; 520 } 521 } 522 523 if (op->flags & RX_CHECK_DLC) { 524 /* do a real check in CAN frame length */ 525 if (rxdata->len != lcf->len) { 526 bcm_rx_update_and_send(op, lcf, rxdata); 527 return; 528 } 529 } 530 } 531 532 /* 533 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 534 */ 535 static void bcm_rx_starttimer(struct bcm_op *op) 536 { 537 if (op->flags & RX_NO_AUTOTIMER) 538 return; 539 540 if (op->kt_ival1.tv64) 541 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); 542 } 543 544 static void bcm_rx_timeout_tsklet(unsigned long data) 545 { 546 struct bcm_op *op = (struct bcm_op *)data; 547 struct bcm_msg_head msg_head; 548 549 /* create notification to user */ 550 msg_head.opcode = RX_TIMEOUT; 551 msg_head.flags = op->flags; 552 msg_head.count = op->count; 553 msg_head.ival1 = op->ival1; 554 msg_head.ival2 = op->ival2; 555 msg_head.can_id = op->can_id; 556 msg_head.nframes = 0; 557 558 bcm_send_to_user(op, &msg_head, NULL, 0); 559 } 560 561 /* 562 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out 563 */ 564 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 565 { 566 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 567 568 /* schedule before NET_RX_SOFTIRQ */ 569 tasklet_hi_schedule(&op->tsklet); 570 571 /* no restart of the timer is done here! */ 572 573 /* if user wants to be informed, when cyclic CAN-Messages come back */ 574 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 575 /* clear received CAN frames to indicate 'nothing received' */ 576 memset(op->last_frames, 0, op->nframes * op->cfsiz); 577 } 578 579 return HRTIMER_NORESTART; 580 } 581 582 /* 583 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 584 */ 585 static inline int bcm_rx_do_flush(struct bcm_op *op, int update, 586 unsigned int index) 587 { 588 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 589 590 if ((op->last_frames) && (lcf->flags & RX_THR)) { 591 if (update) 592 bcm_rx_changed(op, lcf); 593 return 1; 594 } 595 return 0; 596 } 597 598 /* 599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 600 * 601 * update == 0 : just check if throttled data is available (any irq context) 602 * update == 1 : check and send throttled data to userspace (soft_irq context) 603 */ 604 static int bcm_rx_thr_flush(struct bcm_op *op, int update) 605 { 606 int updated = 0; 607 608 if (op->nframes > 1) { 609 unsigned int i; 610 611 /* for MUX filter we start at index 1 */ 612 for (i = 1; i < op->nframes; i++) 613 updated += bcm_rx_do_flush(op, update, i); 614 615 } else { 616 /* for RX_FILTER_ID and simple filter */ 617 updated += bcm_rx_do_flush(op, update, 0); 618 } 619 620 return updated; 621 } 622 623 static void bcm_rx_thr_tsklet(unsigned long data) 624 { 625 struct bcm_op *op = (struct bcm_op *)data; 626 627 /* push the changed data to the userspace */ 628 bcm_rx_thr_flush(op, 1); 629 } 630 631 /* 632 * bcm_rx_thr_handler - the time for blocked content updates is over now: 633 * Check for throttled data and send it to the userspace 634 */ 635 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 636 { 637 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 638 639 tasklet_schedule(&op->thrtsklet); 640 641 if (bcm_rx_thr_flush(op, 0)) { 642 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); 643 return HRTIMER_RESTART; 644 } else { 645 /* rearm throttle handling */ 646 op->kt_lastmsg = ktime_set(0, 0); 647 return HRTIMER_NORESTART; 648 } 649 } 650 651 /* 652 * bcm_rx_handler - handle a CAN frame reception 653 */ 654 static void bcm_rx_handler(struct sk_buff *skb, void *data) 655 { 656 struct bcm_op *op = (struct bcm_op *)data; 657 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 658 unsigned int i; 659 660 if (op->can_id != rxframe->can_id) 661 return; 662 663 /* make sure to handle the correct frame type (CAN / CAN FD) */ 664 if (skb->len != op->cfsiz) 665 return; 666 667 /* disable timeout */ 668 hrtimer_cancel(&op->timer); 669 670 /* save rx timestamp */ 671 op->rx_stamp = skb->tstamp; 672 /* save originator for recvfrom() */ 673 op->rx_ifindex = skb->dev->ifindex; 674 /* update statistics */ 675 op->frames_abs++; 676 677 if (op->flags & RX_RTR_FRAME) { 678 /* send reply for RTR-request (placed in op->frames[0]) */ 679 bcm_can_tx(op); 680 return; 681 } 682 683 if (op->flags & RX_FILTER_ID) { 684 /* the easiest case */ 685 bcm_rx_update_and_send(op, op->last_frames, rxframe); 686 goto rx_starttimer; 687 } 688 689 if (op->nframes == 1) { 690 /* simple compare with index 0 */ 691 bcm_rx_cmp_to_index(op, 0, rxframe); 692 goto rx_starttimer; 693 } 694 695 if (op->nframes > 1) { 696 /* 697 * multiplex compare 698 * 699 * find the first multiplex mask that fits. 700 * Remark: The MUX-mask is stored in index 0 - but only the 701 * first 64 bits of the frame data[] are relevant (CAN FD) 702 */ 703 704 for (i = 1; i < op->nframes; i++) { 705 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 706 (get_u64(op->frames, 0) & 707 get_u64(op->frames + op->cfsiz * i, 0))) { 708 bcm_rx_cmp_to_index(op, i, rxframe); 709 break; 710 } 711 } 712 } 713 714 rx_starttimer: 715 bcm_rx_starttimer(op); 716 } 717 718 /* 719 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 720 */ 721 static struct bcm_op *bcm_find_op(struct list_head *ops, 722 struct bcm_msg_head *mh, int ifindex) 723 { 724 struct bcm_op *op; 725 726 list_for_each_entry(op, ops, list) { 727 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 728 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 729 return op; 730 } 731 732 return NULL; 733 } 734 735 static void bcm_remove_op(struct bcm_op *op) 736 { 737 hrtimer_cancel(&op->timer); 738 hrtimer_cancel(&op->thrtimer); 739 740 if (op->tsklet.func) 741 tasklet_kill(&op->tsklet); 742 743 if (op->thrtsklet.func) 744 tasklet_kill(&op->thrtsklet); 745 746 if ((op->frames) && (op->frames != &op->sframe)) 747 kfree(op->frames); 748 749 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 750 kfree(op->last_frames); 751 752 kfree(op); 753 } 754 755 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 756 { 757 if (op->rx_reg_dev == dev) { 758 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id), 759 bcm_rx_handler, op); 760 761 /* mark as removed subscription */ 762 op->rx_reg_dev = NULL; 763 } else 764 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 765 "mismatch %p %p\n", op->rx_reg_dev, dev); 766 } 767 768 /* 769 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 770 */ 771 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 772 int ifindex) 773 { 774 struct bcm_op *op, *n; 775 776 list_for_each_entry_safe(op, n, ops, list) { 777 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 778 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 779 780 /* 781 * Don't care if we're bound or not (due to netdev 782 * problems) can_rx_unregister() is always a save 783 * thing to do here. 784 */ 785 if (op->ifindex) { 786 /* 787 * Only remove subscriptions that had not 788 * been removed due to NETDEV_UNREGISTER 789 * in bcm_notifier() 790 */ 791 if (op->rx_reg_dev) { 792 struct net_device *dev; 793 794 dev = dev_get_by_index(&init_net, 795 op->ifindex); 796 if (dev) { 797 bcm_rx_unreg(dev, op); 798 dev_put(dev); 799 } 800 } 801 } else 802 can_rx_unregister(NULL, op->can_id, 803 REGMASK(op->can_id), 804 bcm_rx_handler, op); 805 806 list_del(&op->list); 807 bcm_remove_op(op); 808 return 1; /* done */ 809 } 810 } 811 812 return 0; /* not found */ 813 } 814 815 /* 816 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 817 */ 818 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 819 int ifindex) 820 { 821 struct bcm_op *op, *n; 822 823 list_for_each_entry_safe(op, n, ops, list) { 824 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 825 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 826 list_del(&op->list); 827 bcm_remove_op(op); 828 return 1; /* done */ 829 } 830 } 831 832 return 0; /* not found */ 833 } 834 835 /* 836 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 837 */ 838 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 839 int ifindex) 840 { 841 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 842 843 if (!op) 844 return -EINVAL; 845 846 /* put current values into msg_head */ 847 msg_head->flags = op->flags; 848 msg_head->count = op->count; 849 msg_head->ival1 = op->ival1; 850 msg_head->ival2 = op->ival2; 851 msg_head->nframes = op->nframes; 852 853 bcm_send_to_user(op, msg_head, op->frames, 0); 854 855 return MHSIZ; 856 } 857 858 /* 859 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 860 */ 861 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 862 int ifindex, struct sock *sk) 863 { 864 struct bcm_sock *bo = bcm_sk(sk); 865 struct bcm_op *op; 866 struct canfd_frame *cf; 867 unsigned int i; 868 int err; 869 870 /* we need a real device to send frames */ 871 if (!ifindex) 872 return -ENODEV; 873 874 /* check nframes boundaries - we need at least one CAN frame */ 875 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 876 return -EINVAL; 877 878 /* check the given can_id */ 879 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 880 if (op) { 881 /* update existing BCM operation */ 882 883 /* 884 * Do we need more space for the CAN frames than currently 885 * allocated? -> This is a _really_ unusual use-case and 886 * therefore (complexity / locking) it is not supported. 887 */ 888 if (msg_head->nframes > op->nframes) 889 return -E2BIG; 890 891 /* update CAN frames content */ 892 for (i = 0; i < msg_head->nframes; i++) { 893 894 cf = op->frames + op->cfsiz * i; 895 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 896 897 if (op->flags & CAN_FD_FRAME) { 898 if (cf->len > 64) 899 err = -EINVAL; 900 } else { 901 if (cf->len > 8) 902 err = -EINVAL; 903 } 904 905 if (err < 0) 906 return err; 907 908 if (msg_head->flags & TX_CP_CAN_ID) { 909 /* copy can_id into frame */ 910 cf->can_id = msg_head->can_id; 911 } 912 } 913 op->flags = msg_head->flags; 914 915 } else { 916 /* insert new BCM operation for the given can_id */ 917 918 op = kzalloc(OPSIZ, GFP_KERNEL); 919 if (!op) 920 return -ENOMEM; 921 922 op->can_id = msg_head->can_id; 923 op->cfsiz = CFSIZ(msg_head->flags); 924 op->flags = msg_head->flags; 925 926 /* create array for CAN frames and copy the data */ 927 if (msg_head->nframes > 1) { 928 op->frames = kmalloc(msg_head->nframes * op->cfsiz, 929 GFP_KERNEL); 930 if (!op->frames) { 931 kfree(op); 932 return -ENOMEM; 933 } 934 } else 935 op->frames = &op->sframe; 936 937 for (i = 0; i < msg_head->nframes; i++) { 938 939 cf = op->frames + op->cfsiz * i; 940 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 941 942 if (op->flags & CAN_FD_FRAME) { 943 if (cf->len > 64) 944 err = -EINVAL; 945 } else { 946 if (cf->len > 8) 947 err = -EINVAL; 948 } 949 950 if (err < 0) { 951 if (op->frames != &op->sframe) 952 kfree(op->frames); 953 kfree(op); 954 return err; 955 } 956 957 if (msg_head->flags & TX_CP_CAN_ID) { 958 /* copy can_id into frame */ 959 cf->can_id = msg_head->can_id; 960 } 961 } 962 963 /* tx_ops never compare with previous received messages */ 964 op->last_frames = NULL; 965 966 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 967 op->sk = sk; 968 op->ifindex = ifindex; 969 970 /* initialize uninitialized (kzalloc) structure */ 971 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 972 op->timer.function = bcm_tx_timeout_handler; 973 974 /* initialize tasklet for tx countevent notification */ 975 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, 976 (unsigned long) op); 977 978 /* currently unused in tx_ops */ 979 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 980 981 /* add this bcm_op to the list of the tx_ops */ 982 list_add(&op->list, &bo->tx_ops); 983 984 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 985 986 if (op->nframes != msg_head->nframes) { 987 op->nframes = msg_head->nframes; 988 /* start multiple frame transmission with index 0 */ 989 op->currframe = 0; 990 } 991 992 /* check flags */ 993 994 if (op->flags & TX_RESET_MULTI_IDX) { 995 /* start multiple frame transmission with index 0 */ 996 op->currframe = 0; 997 } 998 999 if (op->flags & SETTIMER) { 1000 /* set timer values */ 1001 op->count = msg_head->count; 1002 op->ival1 = msg_head->ival1; 1003 op->ival2 = msg_head->ival2; 1004 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1005 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1006 1007 /* disable an active timer due to zero values? */ 1008 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64) 1009 hrtimer_cancel(&op->timer); 1010 } 1011 1012 if (op->flags & STARTTIMER) { 1013 hrtimer_cancel(&op->timer); 1014 /* spec: send CAN frame when starting timer */ 1015 op->flags |= TX_ANNOUNCE; 1016 } 1017 1018 if (op->flags & TX_ANNOUNCE) { 1019 bcm_can_tx(op); 1020 if (op->count) 1021 op->count--; 1022 } 1023 1024 if (op->flags & STARTTIMER) 1025 bcm_tx_start_timer(op); 1026 1027 return msg_head->nframes * op->cfsiz + MHSIZ; 1028 } 1029 1030 /* 1031 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1032 */ 1033 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1034 int ifindex, struct sock *sk) 1035 { 1036 struct bcm_sock *bo = bcm_sk(sk); 1037 struct bcm_op *op; 1038 int do_rx_register; 1039 int err = 0; 1040 1041 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1042 /* be robust against wrong usage ... */ 1043 msg_head->flags |= RX_FILTER_ID; 1044 /* ignore trailing garbage */ 1045 msg_head->nframes = 0; 1046 } 1047 1048 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1049 if (msg_head->nframes > MAX_NFRAMES + 1) 1050 return -EINVAL; 1051 1052 if ((msg_head->flags & RX_RTR_FRAME) && 1053 ((msg_head->nframes != 1) || 1054 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1055 return -EINVAL; 1056 1057 /* check the given can_id */ 1058 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1059 if (op) { 1060 /* update existing BCM operation */ 1061 1062 /* 1063 * Do we need more space for the CAN frames than currently 1064 * allocated? -> This is a _really_ unusual use-case and 1065 * therefore (complexity / locking) it is not supported. 1066 */ 1067 if (msg_head->nframes > op->nframes) 1068 return -E2BIG; 1069 1070 if (msg_head->nframes) { 1071 /* update CAN frames content */ 1072 err = memcpy_from_msg(op->frames, msg, 1073 msg_head->nframes * op->cfsiz); 1074 if (err < 0) 1075 return err; 1076 1077 /* clear last_frames to indicate 'nothing received' */ 1078 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1079 } 1080 1081 op->nframes = msg_head->nframes; 1082 op->flags = msg_head->flags; 1083 1084 /* Only an update -> do not call can_rx_register() */ 1085 do_rx_register = 0; 1086 1087 } else { 1088 /* insert new BCM operation for the given can_id */ 1089 op = kzalloc(OPSIZ, GFP_KERNEL); 1090 if (!op) 1091 return -ENOMEM; 1092 1093 op->can_id = msg_head->can_id; 1094 op->nframes = msg_head->nframes; 1095 op->cfsiz = CFSIZ(msg_head->flags); 1096 op->flags = msg_head->flags; 1097 1098 if (msg_head->nframes > 1) { 1099 /* create array for CAN frames and copy the data */ 1100 op->frames = kmalloc(msg_head->nframes * op->cfsiz, 1101 GFP_KERNEL); 1102 if (!op->frames) { 1103 kfree(op); 1104 return -ENOMEM; 1105 } 1106 1107 /* create and init array for received CAN frames */ 1108 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz, 1109 GFP_KERNEL); 1110 if (!op->last_frames) { 1111 kfree(op->frames); 1112 kfree(op); 1113 return -ENOMEM; 1114 } 1115 1116 } else { 1117 op->frames = &op->sframe; 1118 op->last_frames = &op->last_sframe; 1119 } 1120 1121 if (msg_head->nframes) { 1122 err = memcpy_from_msg(op->frames, msg, 1123 msg_head->nframes * op->cfsiz); 1124 if (err < 0) { 1125 if (op->frames != &op->sframe) 1126 kfree(op->frames); 1127 if (op->last_frames != &op->last_sframe) 1128 kfree(op->last_frames); 1129 kfree(op); 1130 return err; 1131 } 1132 } 1133 1134 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1135 op->sk = sk; 1136 op->ifindex = ifindex; 1137 1138 /* ifindex for timeout events w/o previous frame reception */ 1139 op->rx_ifindex = ifindex; 1140 1141 /* initialize uninitialized (kzalloc) structure */ 1142 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1143 op->timer.function = bcm_rx_timeout_handler; 1144 1145 /* initialize tasklet for rx timeout notification */ 1146 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, 1147 (unsigned long) op); 1148 1149 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1150 op->thrtimer.function = bcm_rx_thr_handler; 1151 1152 /* initialize tasklet for rx throttle handling */ 1153 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, 1154 (unsigned long) op); 1155 1156 /* add this bcm_op to the list of the rx_ops */ 1157 list_add(&op->list, &bo->rx_ops); 1158 1159 /* call can_rx_register() */ 1160 do_rx_register = 1; 1161 1162 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1163 1164 /* check flags */ 1165 1166 if (op->flags & RX_RTR_FRAME) { 1167 struct canfd_frame *frame0 = op->frames; 1168 1169 /* no timers in RTR-mode */ 1170 hrtimer_cancel(&op->thrtimer); 1171 hrtimer_cancel(&op->timer); 1172 1173 /* 1174 * funny feature in RX(!)_SETUP only for RTR-mode: 1175 * copy can_id into frame BUT without RTR-flag to 1176 * prevent a full-load-loopback-test ... ;-] 1177 */ 1178 if ((op->flags & TX_CP_CAN_ID) || 1179 (frame0->can_id == op->can_id)) 1180 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1181 1182 } else { 1183 if (op->flags & SETTIMER) { 1184 1185 /* set timer value */ 1186 op->ival1 = msg_head->ival1; 1187 op->ival2 = msg_head->ival2; 1188 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1189 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1190 1191 /* disable an active timer due to zero value? */ 1192 if (!op->kt_ival1.tv64) 1193 hrtimer_cancel(&op->timer); 1194 1195 /* 1196 * In any case cancel the throttle timer, flush 1197 * potentially blocked msgs and reset throttle handling 1198 */ 1199 op->kt_lastmsg = ktime_set(0, 0); 1200 hrtimer_cancel(&op->thrtimer); 1201 bcm_rx_thr_flush(op, 1); 1202 } 1203 1204 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64) 1205 hrtimer_start(&op->timer, op->kt_ival1, 1206 HRTIMER_MODE_REL); 1207 } 1208 1209 /* now we can register for can_ids, if we added a new bcm_op */ 1210 if (do_rx_register) { 1211 if (ifindex) { 1212 struct net_device *dev; 1213 1214 dev = dev_get_by_index(&init_net, ifindex); 1215 if (dev) { 1216 err = can_rx_register(dev, op->can_id, 1217 REGMASK(op->can_id), 1218 bcm_rx_handler, op, 1219 "bcm"); 1220 1221 op->rx_reg_dev = dev; 1222 dev_put(dev); 1223 } 1224 1225 } else 1226 err = can_rx_register(NULL, op->can_id, 1227 REGMASK(op->can_id), 1228 bcm_rx_handler, op, "bcm"); 1229 if (err) { 1230 /* this bcm rx op is broken -> remove it */ 1231 list_del(&op->list); 1232 bcm_remove_op(op); 1233 return err; 1234 } 1235 } 1236 1237 return msg_head->nframes * op->cfsiz + MHSIZ; 1238 } 1239 1240 /* 1241 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1242 */ 1243 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1244 int cfsiz) 1245 { 1246 struct sk_buff *skb; 1247 struct net_device *dev; 1248 int err; 1249 1250 /* we need a real device to send frames */ 1251 if (!ifindex) 1252 return -ENODEV; 1253 1254 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1255 if (!skb) 1256 return -ENOMEM; 1257 1258 can_skb_reserve(skb); 1259 1260 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1261 if (err < 0) { 1262 kfree_skb(skb); 1263 return err; 1264 } 1265 1266 dev = dev_get_by_index(&init_net, ifindex); 1267 if (!dev) { 1268 kfree_skb(skb); 1269 return -ENODEV; 1270 } 1271 1272 can_skb_prv(skb)->ifindex = dev->ifindex; 1273 can_skb_prv(skb)->skbcnt = 0; 1274 skb->dev = dev; 1275 can_skb_set_owner(skb, sk); 1276 err = can_send(skb, 1); /* send with loopback */ 1277 dev_put(dev); 1278 1279 if (err) 1280 return err; 1281 1282 return cfsiz + MHSIZ; 1283 } 1284 1285 /* 1286 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1287 */ 1288 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1289 { 1290 struct sock *sk = sock->sk; 1291 struct bcm_sock *bo = bcm_sk(sk); 1292 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1293 struct bcm_msg_head msg_head; 1294 int cfsiz; 1295 int ret; /* read bytes or error codes as return value */ 1296 1297 if (!bo->bound) 1298 return -ENOTCONN; 1299 1300 /* check for valid message length from userspace */ 1301 if (size < MHSIZ) 1302 return -EINVAL; 1303 1304 /* read message head information */ 1305 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1306 if (ret < 0) 1307 return ret; 1308 1309 cfsiz = CFSIZ(msg_head.flags); 1310 if ((size - MHSIZ) % cfsiz) 1311 return -EINVAL; 1312 1313 /* check for alternative ifindex for this bcm_op */ 1314 1315 if (!ifindex && msg->msg_name) { 1316 /* no bound device as default => check msg_name */ 1317 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1318 1319 if (msg->msg_namelen < sizeof(*addr)) 1320 return -EINVAL; 1321 1322 if (addr->can_family != AF_CAN) 1323 return -EINVAL; 1324 1325 /* ifindex from sendto() */ 1326 ifindex = addr->can_ifindex; 1327 1328 if (ifindex) { 1329 struct net_device *dev; 1330 1331 dev = dev_get_by_index(&init_net, ifindex); 1332 if (!dev) 1333 return -ENODEV; 1334 1335 if (dev->type != ARPHRD_CAN) { 1336 dev_put(dev); 1337 return -ENODEV; 1338 } 1339 1340 dev_put(dev); 1341 } 1342 } 1343 1344 lock_sock(sk); 1345 1346 switch (msg_head.opcode) { 1347 1348 case TX_SETUP: 1349 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1350 break; 1351 1352 case RX_SETUP: 1353 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1354 break; 1355 1356 case TX_DELETE: 1357 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1358 ret = MHSIZ; 1359 else 1360 ret = -EINVAL; 1361 break; 1362 1363 case RX_DELETE: 1364 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1365 ret = MHSIZ; 1366 else 1367 ret = -EINVAL; 1368 break; 1369 1370 case TX_READ: 1371 /* reuse msg_head for the reply to TX_READ */ 1372 msg_head.opcode = TX_STATUS; 1373 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1374 break; 1375 1376 case RX_READ: 1377 /* reuse msg_head for the reply to RX_READ */ 1378 msg_head.opcode = RX_STATUS; 1379 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1380 break; 1381 1382 case TX_SEND: 1383 /* we need exactly one CAN frame behind the msg head */ 1384 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1385 ret = -EINVAL; 1386 else 1387 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1388 break; 1389 1390 default: 1391 ret = -EINVAL; 1392 break; 1393 } 1394 1395 release_sock(sk); 1396 1397 return ret; 1398 } 1399 1400 /* 1401 * notification handler for netdevice status changes 1402 */ 1403 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1404 void *ptr) 1405 { 1406 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1407 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); 1408 struct sock *sk = &bo->sk; 1409 struct bcm_op *op; 1410 int notify_enodev = 0; 1411 1412 if (!net_eq(dev_net(dev), &init_net)) 1413 return NOTIFY_DONE; 1414 1415 if (dev->type != ARPHRD_CAN) 1416 return NOTIFY_DONE; 1417 1418 switch (msg) { 1419 1420 case NETDEV_UNREGISTER: 1421 lock_sock(sk); 1422 1423 /* remove device specific receive entries */ 1424 list_for_each_entry(op, &bo->rx_ops, list) 1425 if (op->rx_reg_dev == dev) 1426 bcm_rx_unreg(dev, op); 1427 1428 /* remove device reference, if this is our bound device */ 1429 if (bo->bound && bo->ifindex == dev->ifindex) { 1430 bo->bound = 0; 1431 bo->ifindex = 0; 1432 notify_enodev = 1; 1433 } 1434 1435 release_sock(sk); 1436 1437 if (notify_enodev) { 1438 sk->sk_err = ENODEV; 1439 if (!sock_flag(sk, SOCK_DEAD)) 1440 sk->sk_error_report(sk); 1441 } 1442 break; 1443 1444 case NETDEV_DOWN: 1445 if (bo->bound && bo->ifindex == dev->ifindex) { 1446 sk->sk_err = ENETDOWN; 1447 if (!sock_flag(sk, SOCK_DEAD)) 1448 sk->sk_error_report(sk); 1449 } 1450 } 1451 1452 return NOTIFY_DONE; 1453 } 1454 1455 /* 1456 * initial settings for all BCM sockets to be set at socket creation time 1457 */ 1458 static int bcm_init(struct sock *sk) 1459 { 1460 struct bcm_sock *bo = bcm_sk(sk); 1461 1462 bo->bound = 0; 1463 bo->ifindex = 0; 1464 bo->dropped_usr_msgs = 0; 1465 bo->bcm_proc_read = NULL; 1466 1467 INIT_LIST_HEAD(&bo->tx_ops); 1468 INIT_LIST_HEAD(&bo->rx_ops); 1469 1470 /* set notifier */ 1471 bo->notifier.notifier_call = bcm_notifier; 1472 1473 register_netdevice_notifier(&bo->notifier); 1474 1475 return 0; 1476 } 1477 1478 /* 1479 * standard socket functions 1480 */ 1481 static int bcm_release(struct socket *sock) 1482 { 1483 struct sock *sk = sock->sk; 1484 struct bcm_sock *bo; 1485 struct bcm_op *op, *next; 1486 1487 if (sk == NULL) 1488 return 0; 1489 1490 bo = bcm_sk(sk); 1491 1492 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1493 1494 unregister_netdevice_notifier(&bo->notifier); 1495 1496 lock_sock(sk); 1497 1498 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1499 bcm_remove_op(op); 1500 1501 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1502 /* 1503 * Don't care if we're bound or not (due to netdev problems) 1504 * can_rx_unregister() is always a save thing to do here. 1505 */ 1506 if (op->ifindex) { 1507 /* 1508 * Only remove subscriptions that had not 1509 * been removed due to NETDEV_UNREGISTER 1510 * in bcm_notifier() 1511 */ 1512 if (op->rx_reg_dev) { 1513 struct net_device *dev; 1514 1515 dev = dev_get_by_index(&init_net, op->ifindex); 1516 if (dev) { 1517 bcm_rx_unreg(dev, op); 1518 dev_put(dev); 1519 } 1520 } 1521 } else 1522 can_rx_unregister(NULL, op->can_id, 1523 REGMASK(op->can_id), 1524 bcm_rx_handler, op); 1525 1526 bcm_remove_op(op); 1527 } 1528 1529 /* remove procfs entry */ 1530 if (proc_dir && bo->bcm_proc_read) 1531 remove_proc_entry(bo->procname, proc_dir); 1532 1533 /* remove device reference */ 1534 if (bo->bound) { 1535 bo->bound = 0; 1536 bo->ifindex = 0; 1537 } 1538 1539 sock_orphan(sk); 1540 sock->sk = NULL; 1541 1542 release_sock(sk); 1543 sock_put(sk); 1544 1545 return 0; 1546 } 1547 1548 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1549 int flags) 1550 { 1551 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1552 struct sock *sk = sock->sk; 1553 struct bcm_sock *bo = bcm_sk(sk); 1554 int ret = 0; 1555 1556 if (len < sizeof(*addr)) 1557 return -EINVAL; 1558 1559 lock_sock(sk); 1560 1561 if (bo->bound) { 1562 ret = -EISCONN; 1563 goto fail; 1564 } 1565 1566 /* bind a device to this socket */ 1567 if (addr->can_ifindex) { 1568 struct net_device *dev; 1569 1570 dev = dev_get_by_index(&init_net, addr->can_ifindex); 1571 if (!dev) { 1572 ret = -ENODEV; 1573 goto fail; 1574 } 1575 if (dev->type != ARPHRD_CAN) { 1576 dev_put(dev); 1577 ret = -ENODEV; 1578 goto fail; 1579 } 1580 1581 bo->ifindex = dev->ifindex; 1582 dev_put(dev); 1583 1584 } else { 1585 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1586 bo->ifindex = 0; 1587 } 1588 1589 if (proc_dir) { 1590 /* unique socket address as filename */ 1591 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1592 bo->bcm_proc_read = proc_create_data(bo->procname, 0644, 1593 proc_dir, 1594 &bcm_proc_fops, sk); 1595 if (!bo->bcm_proc_read) { 1596 ret = -ENOMEM; 1597 goto fail; 1598 } 1599 } 1600 1601 bo->bound = 1; 1602 1603 fail: 1604 release_sock(sk); 1605 1606 return ret; 1607 } 1608 1609 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1610 int flags) 1611 { 1612 struct sock *sk = sock->sk; 1613 struct sk_buff *skb; 1614 int error = 0; 1615 int noblock; 1616 int err; 1617 1618 noblock = flags & MSG_DONTWAIT; 1619 flags &= ~MSG_DONTWAIT; 1620 skb = skb_recv_datagram(sk, flags, noblock, &error); 1621 if (!skb) 1622 return error; 1623 1624 if (skb->len < size) 1625 size = skb->len; 1626 1627 err = memcpy_to_msg(msg, skb->data, size); 1628 if (err < 0) { 1629 skb_free_datagram(sk, skb); 1630 return err; 1631 } 1632 1633 sock_recv_ts_and_drops(msg, sk, skb); 1634 1635 if (msg->msg_name) { 1636 __sockaddr_check_size(sizeof(struct sockaddr_can)); 1637 msg->msg_namelen = sizeof(struct sockaddr_can); 1638 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1639 } 1640 1641 skb_free_datagram(sk, skb); 1642 1643 return size; 1644 } 1645 1646 static const struct proto_ops bcm_ops = { 1647 .family = PF_CAN, 1648 .release = bcm_release, 1649 .bind = sock_no_bind, 1650 .connect = bcm_connect, 1651 .socketpair = sock_no_socketpair, 1652 .accept = sock_no_accept, 1653 .getname = sock_no_getname, 1654 .poll = datagram_poll, 1655 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */ 1656 .listen = sock_no_listen, 1657 .shutdown = sock_no_shutdown, 1658 .setsockopt = sock_no_setsockopt, 1659 .getsockopt = sock_no_getsockopt, 1660 .sendmsg = bcm_sendmsg, 1661 .recvmsg = bcm_recvmsg, 1662 .mmap = sock_no_mmap, 1663 .sendpage = sock_no_sendpage, 1664 }; 1665 1666 static struct proto bcm_proto __read_mostly = { 1667 .name = "CAN_BCM", 1668 .owner = THIS_MODULE, 1669 .obj_size = sizeof(struct bcm_sock), 1670 .init = bcm_init, 1671 }; 1672 1673 static const struct can_proto bcm_can_proto = { 1674 .type = SOCK_DGRAM, 1675 .protocol = CAN_BCM, 1676 .ops = &bcm_ops, 1677 .prot = &bcm_proto, 1678 }; 1679 1680 static int __init bcm_module_init(void) 1681 { 1682 int err; 1683 1684 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"); 1685 1686 err = can_proto_register(&bcm_can_proto); 1687 if (err < 0) { 1688 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1689 return err; 1690 } 1691 1692 /* create /proc/net/can-bcm directory */ 1693 proc_dir = proc_mkdir("can-bcm", init_net.proc_net); 1694 return 0; 1695 } 1696 1697 static void __exit bcm_module_exit(void) 1698 { 1699 can_proto_unregister(&bcm_can_proto); 1700 1701 if (proc_dir) 1702 remove_proc_entry("can-bcm", init_net.proc_net); 1703 } 1704 1705 module_init(bcm_module_init); 1706 module_exit(bcm_module_exit); 1707