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