1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) 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 #define CAN_BCM_VERSION "20170425" 85 86 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 87 MODULE_LICENSE("Dual BSD/GPL"); 88 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 89 MODULE_ALIAS("can-proto-2"); 90 91 /* 92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is 93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured 94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler(). 95 */ 96 static inline u64 get_u64(const struct canfd_frame *cp, int offset) 97 { 98 return *(u64 *)(cp->data + offset); 99 } 100 101 struct bcm_op { 102 struct list_head list; 103 int ifindex; 104 canid_t can_id; 105 u32 flags; 106 unsigned long frames_abs, frames_filtered; 107 struct bcm_timeval ival1, ival2; 108 struct hrtimer timer, thrtimer; 109 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 110 int rx_ifindex; 111 int cfsiz; 112 u32 count; 113 u32 nframes; 114 u32 currframe; 115 /* void pointers to arrays of struct can[fd]_frame */ 116 void *frames; 117 void *last_frames; 118 struct canfd_frame sframe; 119 struct canfd_frame last_sframe; 120 struct sock *sk; 121 struct net_device *rx_reg_dev; 122 }; 123 124 struct bcm_sock { 125 struct sock sk; 126 int bound; 127 int ifindex; 128 struct notifier_block notifier; 129 struct list_head rx_ops; 130 struct list_head tx_ops; 131 unsigned long dropped_usr_msgs; 132 struct proc_dir_entry *bcm_proc_read; 133 char procname [32]; /* inode number in decimal with \0 */ 134 }; 135 136 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 137 { 138 return (struct bcm_sock *)sk; 139 } 140 141 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 142 { 143 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 144 } 145 146 /* check limitations for timeval provided by user */ 147 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 148 { 149 if ((msg_head->ival1.tv_sec < 0) || 150 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 151 (msg_head->ival1.tv_usec < 0) || 152 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 153 (msg_head->ival2.tv_sec < 0) || 154 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 155 (msg_head->ival2.tv_usec < 0) || 156 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 157 return true; 158 159 return false; 160 } 161 162 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 163 #define OPSIZ sizeof(struct bcm_op) 164 #define MHSIZ sizeof(struct bcm_msg_head) 165 166 /* 167 * procfs functions 168 */ 169 #if IS_ENABLED(CONFIG_PROC_FS) 170 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 171 { 172 struct net_device *dev; 173 174 if (!ifindex) 175 return "any"; 176 177 rcu_read_lock(); 178 dev = dev_get_by_index_rcu(net, ifindex); 179 if (dev) 180 strcpy(result, dev->name); 181 else 182 strcpy(result, "???"); 183 rcu_read_unlock(); 184 185 return result; 186 } 187 188 static int bcm_proc_show(struct seq_file *m, void *v) 189 { 190 char ifname[IFNAMSIZ]; 191 struct net *net = m->private; 192 struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode); 193 struct bcm_sock *bo = bcm_sk(sk); 194 struct bcm_op *op; 195 196 seq_printf(m, ">>> socket %pK", sk->sk_socket); 197 seq_printf(m, " / sk %pK", sk); 198 seq_printf(m, " / bo %pK", bo); 199 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 200 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 201 seq_printf(m, " <<<\n"); 202 203 list_for_each_entry(op, &bo->rx_ops, list) { 204 205 unsigned long reduction; 206 207 /* print only active entries & prevent division by zero */ 208 if (!op->frames_abs) 209 continue; 210 211 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 212 bcm_proc_getifname(net, ifname, op->ifindex)); 213 214 if (op->flags & CAN_FD_FRAME) 215 seq_printf(m, "(%u)", op->nframes); 216 else 217 seq_printf(m, "[%u]", op->nframes); 218 219 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 220 221 if (op->kt_ival1) 222 seq_printf(m, "timeo=%lld ", 223 (long long)ktime_to_us(op->kt_ival1)); 224 225 if (op->kt_ival2) 226 seq_printf(m, "thr=%lld ", 227 (long long)ktime_to_us(op->kt_ival2)); 228 229 seq_printf(m, "# recv %ld (%ld) => reduction: ", 230 op->frames_filtered, op->frames_abs); 231 232 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 233 234 seq_printf(m, "%s%ld%%\n", 235 (reduction == 100) ? "near " : "", reduction); 236 } 237 238 list_for_each_entry(op, &bo->tx_ops, list) { 239 240 seq_printf(m, "tx_op: %03X %s ", op->can_id, 241 bcm_proc_getifname(net, ifname, op->ifindex)); 242 243 if (op->flags & CAN_FD_FRAME) 244 seq_printf(m, "(%u) ", op->nframes); 245 else 246 seq_printf(m, "[%u] ", op->nframes); 247 248 if (op->kt_ival1) 249 seq_printf(m, "t1=%lld ", 250 (long long)ktime_to_us(op->kt_ival1)); 251 252 if (op->kt_ival2) 253 seq_printf(m, "t2=%lld ", 254 (long long)ktime_to_us(op->kt_ival2)); 255 256 seq_printf(m, "# sent %ld\n", op->frames_abs); 257 } 258 seq_putc(m, '\n'); 259 return 0; 260 } 261 #endif /* CONFIG_PROC_FS */ 262 263 /* 264 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 265 * of the given bcm tx op 266 */ 267 static void bcm_can_tx(struct bcm_op *op) 268 { 269 struct sk_buff *skb; 270 struct net_device *dev; 271 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 272 273 /* no target device? => exit */ 274 if (!op->ifindex) 275 return; 276 277 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 278 if (!dev) { 279 /* RFC: should this bcm_op remove itself here? */ 280 return; 281 } 282 283 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 284 if (!skb) 285 goto out; 286 287 can_skb_reserve(skb); 288 can_skb_prv(skb)->ifindex = dev->ifindex; 289 can_skb_prv(skb)->skbcnt = 0; 290 291 skb_put_data(skb, cf, op->cfsiz); 292 293 /* send with loopback */ 294 skb->dev = dev; 295 can_skb_set_owner(skb, op->sk); 296 can_send(skb, 1); 297 298 /* update statistics */ 299 op->currframe++; 300 op->frames_abs++; 301 302 /* reached last frame? */ 303 if (op->currframe >= op->nframes) 304 op->currframe = 0; 305 out: 306 dev_put(dev); 307 } 308 309 /* 310 * bcm_send_to_user - send a BCM message to the userspace 311 * (consisting of bcm_msg_head + x CAN frames) 312 */ 313 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 314 struct canfd_frame *frames, int has_timestamp) 315 { 316 struct sk_buff *skb; 317 struct canfd_frame *firstframe; 318 struct sockaddr_can *addr; 319 struct sock *sk = op->sk; 320 unsigned int datalen = head->nframes * op->cfsiz; 321 int err; 322 323 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 324 if (!skb) 325 return; 326 327 skb_put_data(skb, head, sizeof(*head)); 328 329 if (head->nframes) { 330 /* CAN frames starting here */ 331 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 332 333 skb_put_data(skb, frames, datalen); 334 335 /* 336 * the BCM uses the flags-element of the canfd_frame 337 * structure for internal purposes. This is only 338 * relevant for updates that are generated by the 339 * BCM, where nframes is 1 340 */ 341 if (head->nframes == 1) 342 firstframe->flags &= BCM_CAN_FLAGS_MASK; 343 } 344 345 if (has_timestamp) { 346 /* restore rx timestamp */ 347 skb->tstamp = op->rx_stamp; 348 } 349 350 /* 351 * Put the datagram to the queue so that bcm_recvmsg() can 352 * get it from there. We need to pass the interface index to 353 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 354 * containing the interface index. 355 */ 356 357 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 358 addr = (struct sockaddr_can *)skb->cb; 359 memset(addr, 0, sizeof(*addr)); 360 addr->can_family = AF_CAN; 361 addr->can_ifindex = op->rx_ifindex; 362 363 err = sock_queue_rcv_skb(sk, skb); 364 if (err < 0) { 365 struct bcm_sock *bo = bcm_sk(sk); 366 367 kfree_skb(skb); 368 /* don't care about overflows in this statistic */ 369 bo->dropped_usr_msgs++; 370 } 371 } 372 373 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt) 374 { 375 ktime_t ival; 376 377 if (op->kt_ival1 && op->count) 378 ival = op->kt_ival1; 379 else if (op->kt_ival2) 380 ival = op->kt_ival2; 381 else 382 return false; 383 384 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival)); 385 return true; 386 } 387 388 static void bcm_tx_start_timer(struct bcm_op *op) 389 { 390 if (bcm_tx_set_expiry(op, &op->timer)) 391 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT); 392 } 393 394 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */ 395 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 396 { 397 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 398 struct bcm_msg_head msg_head; 399 400 if (op->kt_ival1 && (op->count > 0)) { 401 op->count--; 402 if (!op->count && (op->flags & TX_COUNTEVT)) { 403 404 /* create notification to user */ 405 msg_head.opcode = TX_EXPIRED; 406 msg_head.flags = op->flags; 407 msg_head.count = op->count; 408 msg_head.ival1 = op->ival1; 409 msg_head.ival2 = op->ival2; 410 msg_head.can_id = op->can_id; 411 msg_head.nframes = 0; 412 413 bcm_send_to_user(op, &msg_head, NULL, 0); 414 } 415 bcm_can_tx(op); 416 417 } else if (op->kt_ival2) { 418 bcm_can_tx(op); 419 } 420 421 return bcm_tx_set_expiry(op, &op->timer) ? 422 HRTIMER_RESTART : HRTIMER_NORESTART; 423 } 424 425 /* 426 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 427 */ 428 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 429 { 430 struct bcm_msg_head head; 431 432 /* update statistics */ 433 op->frames_filtered++; 434 435 /* prevent statistics overflow */ 436 if (op->frames_filtered > ULONG_MAX/100) 437 op->frames_filtered = op->frames_abs = 0; 438 439 /* this element is not throttled anymore */ 440 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 441 442 head.opcode = RX_CHANGED; 443 head.flags = op->flags; 444 head.count = op->count; 445 head.ival1 = op->ival1; 446 head.ival2 = op->ival2; 447 head.can_id = op->can_id; 448 head.nframes = 1; 449 450 bcm_send_to_user(op, &head, data, 1); 451 } 452 453 /* 454 * bcm_rx_update_and_send - process a detected relevant receive content change 455 * 1. update the last received data 456 * 2. send a notification to the user (if possible) 457 */ 458 static void bcm_rx_update_and_send(struct bcm_op *op, 459 struct canfd_frame *lastdata, 460 const struct canfd_frame *rxdata) 461 { 462 memcpy(lastdata, rxdata, op->cfsiz); 463 464 /* mark as used and throttled by default */ 465 lastdata->flags |= (RX_RECV|RX_THR); 466 467 /* throttling mode inactive ? */ 468 if (!op->kt_ival2) { 469 /* send RX_CHANGED to the user immediately */ 470 bcm_rx_changed(op, lastdata); 471 return; 472 } 473 474 /* with active throttling timer we are just done here */ 475 if (hrtimer_active(&op->thrtimer)) 476 return; 477 478 /* first reception with enabled throttling mode */ 479 if (!op->kt_lastmsg) 480 goto rx_changed_settime; 481 482 /* got a second frame inside a potential throttle period? */ 483 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 484 ktime_to_us(op->kt_ival2)) { 485 /* do not send the saved data - only start throttle timer */ 486 hrtimer_start(&op->thrtimer, 487 ktime_add(op->kt_lastmsg, op->kt_ival2), 488 HRTIMER_MODE_ABS_SOFT); 489 return; 490 } 491 492 /* the gap was that big, that throttling was not needed here */ 493 rx_changed_settime: 494 bcm_rx_changed(op, lastdata); 495 op->kt_lastmsg = ktime_get(); 496 } 497 498 /* 499 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 500 * received data stored in op->last_frames[] 501 */ 502 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 503 const struct canfd_frame *rxdata) 504 { 505 struct canfd_frame *cf = op->frames + op->cfsiz * index; 506 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 507 int i; 508 509 /* 510 * no one uses the MSBs of flags for comparison, 511 * so we use it here to detect the first time of reception 512 */ 513 514 if (!(lcf->flags & RX_RECV)) { 515 /* received data for the first time => send update to user */ 516 bcm_rx_update_and_send(op, lcf, rxdata); 517 return; 518 } 519 520 /* do a real check in CAN frame data section */ 521 for (i = 0; i < rxdata->len; i += 8) { 522 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 523 (get_u64(cf, i) & get_u64(lcf, i))) { 524 bcm_rx_update_and_send(op, lcf, rxdata); 525 return; 526 } 527 } 528 529 if (op->flags & RX_CHECK_DLC) { 530 /* do a real check in CAN frame length */ 531 if (rxdata->len != lcf->len) { 532 bcm_rx_update_and_send(op, lcf, rxdata); 533 return; 534 } 535 } 536 } 537 538 /* 539 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 540 */ 541 static void bcm_rx_starttimer(struct bcm_op *op) 542 { 543 if (op->flags & RX_NO_AUTOTIMER) 544 return; 545 546 if (op->kt_ival1) 547 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT); 548 } 549 550 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */ 551 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 552 { 553 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 554 struct bcm_msg_head msg_head; 555 556 /* if user wants to be informed, when cyclic CAN-Messages come back */ 557 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 558 /* clear received CAN frames to indicate 'nothing received' */ 559 memset(op->last_frames, 0, op->nframes * op->cfsiz); 560 } 561 562 /* create notification to user */ 563 msg_head.opcode = RX_TIMEOUT; 564 msg_head.flags = op->flags; 565 msg_head.count = op->count; 566 msg_head.ival1 = op->ival1; 567 msg_head.ival2 = op->ival2; 568 msg_head.can_id = op->can_id; 569 msg_head.nframes = 0; 570 571 bcm_send_to_user(op, &msg_head, NULL, 0); 572 573 return HRTIMER_NORESTART; 574 } 575 576 /* 577 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 578 */ 579 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index) 580 { 581 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 582 583 if ((op->last_frames) && (lcf->flags & RX_THR)) { 584 bcm_rx_changed(op, lcf); 585 return 1; 586 } 587 return 0; 588 } 589 590 /* 591 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 592 */ 593 static int bcm_rx_thr_flush(struct bcm_op *op) 594 { 595 int updated = 0; 596 597 if (op->nframes > 1) { 598 unsigned int i; 599 600 /* for MUX filter we start at index 1 */ 601 for (i = 1; i < op->nframes; i++) 602 updated += bcm_rx_do_flush(op, i); 603 604 } else { 605 /* for RX_FILTER_ID and simple filter */ 606 updated += bcm_rx_do_flush(op, 0); 607 } 608 609 return updated; 610 } 611 612 /* 613 * bcm_rx_thr_handler - the time for blocked content updates is over now: 614 * Check for throttled data and send it to the userspace 615 */ 616 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 617 { 618 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 619 620 if (bcm_rx_thr_flush(op)) { 621 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); 622 return HRTIMER_RESTART; 623 } else { 624 /* rearm throttle handling */ 625 op->kt_lastmsg = 0; 626 return HRTIMER_NORESTART; 627 } 628 } 629 630 /* 631 * bcm_rx_handler - handle a CAN frame reception 632 */ 633 static void bcm_rx_handler(struct sk_buff *skb, void *data) 634 { 635 struct bcm_op *op = (struct bcm_op *)data; 636 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 637 unsigned int i; 638 639 if (op->can_id != rxframe->can_id) 640 return; 641 642 /* make sure to handle the correct frame type (CAN / CAN FD) */ 643 if (skb->len != op->cfsiz) 644 return; 645 646 /* disable timeout */ 647 hrtimer_cancel(&op->timer); 648 649 /* save rx timestamp */ 650 op->rx_stamp = skb->tstamp; 651 /* save originator for recvfrom() */ 652 op->rx_ifindex = skb->dev->ifindex; 653 /* update statistics */ 654 op->frames_abs++; 655 656 if (op->flags & RX_RTR_FRAME) { 657 /* send reply for RTR-request (placed in op->frames[0]) */ 658 bcm_can_tx(op); 659 return; 660 } 661 662 if (op->flags & RX_FILTER_ID) { 663 /* the easiest case */ 664 bcm_rx_update_and_send(op, op->last_frames, rxframe); 665 goto rx_starttimer; 666 } 667 668 if (op->nframes == 1) { 669 /* simple compare with index 0 */ 670 bcm_rx_cmp_to_index(op, 0, rxframe); 671 goto rx_starttimer; 672 } 673 674 if (op->nframes > 1) { 675 /* 676 * multiplex compare 677 * 678 * find the first multiplex mask that fits. 679 * Remark: The MUX-mask is stored in index 0 - but only the 680 * first 64 bits of the frame data[] are relevant (CAN FD) 681 */ 682 683 for (i = 1; i < op->nframes; i++) { 684 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 685 (get_u64(op->frames, 0) & 686 get_u64(op->frames + op->cfsiz * i, 0))) { 687 bcm_rx_cmp_to_index(op, i, rxframe); 688 break; 689 } 690 } 691 } 692 693 rx_starttimer: 694 bcm_rx_starttimer(op); 695 } 696 697 /* 698 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 699 */ 700 static struct bcm_op *bcm_find_op(struct list_head *ops, 701 struct bcm_msg_head *mh, int ifindex) 702 { 703 struct bcm_op *op; 704 705 list_for_each_entry(op, ops, list) { 706 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 707 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 708 return op; 709 } 710 711 return NULL; 712 } 713 714 static void bcm_remove_op(struct bcm_op *op) 715 { 716 hrtimer_cancel(&op->timer); 717 hrtimer_cancel(&op->thrtimer); 718 719 if ((op->frames) && (op->frames != &op->sframe)) 720 kfree(op->frames); 721 722 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 723 kfree(op->last_frames); 724 725 kfree(op); 726 } 727 728 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 729 { 730 if (op->rx_reg_dev == dev) { 731 can_rx_unregister(dev_net(dev), dev, op->can_id, 732 REGMASK(op->can_id), bcm_rx_handler, op); 733 734 /* mark as removed subscription */ 735 op->rx_reg_dev = NULL; 736 } else 737 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 738 "mismatch %p %p\n", op->rx_reg_dev, dev); 739 } 740 741 /* 742 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 743 */ 744 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 745 int ifindex) 746 { 747 struct bcm_op *op, *n; 748 749 list_for_each_entry_safe(op, n, ops, list) { 750 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 751 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 752 753 /* 754 * Don't care if we're bound or not (due to netdev 755 * problems) can_rx_unregister() is always a save 756 * thing to do here. 757 */ 758 if (op->ifindex) { 759 /* 760 * Only remove subscriptions that had not 761 * been removed due to NETDEV_UNREGISTER 762 * in bcm_notifier() 763 */ 764 if (op->rx_reg_dev) { 765 struct net_device *dev; 766 767 dev = dev_get_by_index(sock_net(op->sk), 768 op->ifindex); 769 if (dev) { 770 bcm_rx_unreg(dev, op); 771 dev_put(dev); 772 } 773 } 774 } else 775 can_rx_unregister(sock_net(op->sk), NULL, 776 op->can_id, 777 REGMASK(op->can_id), 778 bcm_rx_handler, op); 779 780 list_del(&op->list); 781 bcm_remove_op(op); 782 return 1; /* done */ 783 } 784 } 785 786 return 0; /* not found */ 787 } 788 789 /* 790 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 791 */ 792 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 793 int ifindex) 794 { 795 struct bcm_op *op, *n; 796 797 list_for_each_entry_safe(op, n, ops, list) { 798 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 799 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 800 list_del(&op->list); 801 bcm_remove_op(op); 802 return 1; /* done */ 803 } 804 } 805 806 return 0; /* not found */ 807 } 808 809 /* 810 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 811 */ 812 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 813 int ifindex) 814 { 815 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 816 817 if (!op) 818 return -EINVAL; 819 820 /* put current values into msg_head */ 821 msg_head->flags = op->flags; 822 msg_head->count = op->count; 823 msg_head->ival1 = op->ival1; 824 msg_head->ival2 = op->ival2; 825 msg_head->nframes = op->nframes; 826 827 bcm_send_to_user(op, msg_head, op->frames, 0); 828 829 return MHSIZ; 830 } 831 832 /* 833 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 834 */ 835 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 836 int ifindex, struct sock *sk) 837 { 838 struct bcm_sock *bo = bcm_sk(sk); 839 struct bcm_op *op; 840 struct canfd_frame *cf; 841 unsigned int i; 842 int err; 843 844 /* we need a real device to send frames */ 845 if (!ifindex) 846 return -ENODEV; 847 848 /* check nframes boundaries - we need at least one CAN frame */ 849 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 850 return -EINVAL; 851 852 /* check timeval limitations */ 853 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 854 return -EINVAL; 855 856 /* check the given can_id */ 857 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 858 if (op) { 859 /* update existing BCM operation */ 860 861 /* 862 * Do we need more space for the CAN frames than currently 863 * allocated? -> This is a _really_ unusual use-case and 864 * therefore (complexity / locking) it is not supported. 865 */ 866 if (msg_head->nframes > op->nframes) 867 return -E2BIG; 868 869 /* update CAN frames content */ 870 for (i = 0; i < msg_head->nframes; i++) { 871 872 cf = op->frames + op->cfsiz * i; 873 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 874 875 if (op->flags & CAN_FD_FRAME) { 876 if (cf->len > 64) 877 err = -EINVAL; 878 } else { 879 if (cf->len > 8) 880 err = -EINVAL; 881 } 882 883 if (err < 0) 884 return err; 885 886 if (msg_head->flags & TX_CP_CAN_ID) { 887 /* copy can_id into frame */ 888 cf->can_id = msg_head->can_id; 889 } 890 } 891 op->flags = msg_head->flags; 892 893 } else { 894 /* insert new BCM operation for the given can_id */ 895 896 op = kzalloc(OPSIZ, GFP_KERNEL); 897 if (!op) 898 return -ENOMEM; 899 900 op->can_id = msg_head->can_id; 901 op->cfsiz = CFSIZ(msg_head->flags); 902 op->flags = msg_head->flags; 903 904 /* create array for CAN frames and copy the data */ 905 if (msg_head->nframes > 1) { 906 op->frames = kmalloc_array(msg_head->nframes, 907 op->cfsiz, 908 GFP_KERNEL); 909 if (!op->frames) { 910 kfree(op); 911 return -ENOMEM; 912 } 913 } else 914 op->frames = &op->sframe; 915 916 for (i = 0; i < msg_head->nframes; i++) { 917 918 cf = op->frames + op->cfsiz * i; 919 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 920 921 if (op->flags & CAN_FD_FRAME) { 922 if (cf->len > 64) 923 err = -EINVAL; 924 } else { 925 if (cf->len > 8) 926 err = -EINVAL; 927 } 928 929 if (err < 0) { 930 if (op->frames != &op->sframe) 931 kfree(op->frames); 932 kfree(op); 933 return err; 934 } 935 936 if (msg_head->flags & TX_CP_CAN_ID) { 937 /* copy can_id into frame */ 938 cf->can_id = msg_head->can_id; 939 } 940 } 941 942 /* tx_ops never compare with previous received messages */ 943 op->last_frames = NULL; 944 945 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 946 op->sk = sk; 947 op->ifindex = ifindex; 948 949 /* initialize uninitialized (kzalloc) structure */ 950 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 951 HRTIMER_MODE_REL_SOFT); 952 op->timer.function = bcm_tx_timeout_handler; 953 954 /* currently unused in tx_ops */ 955 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 956 HRTIMER_MODE_REL_SOFT); 957 958 /* add this bcm_op to the list of the tx_ops */ 959 list_add(&op->list, &bo->tx_ops); 960 961 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 962 963 if (op->nframes != msg_head->nframes) { 964 op->nframes = msg_head->nframes; 965 /* start multiple frame transmission with index 0 */ 966 op->currframe = 0; 967 } 968 969 /* check flags */ 970 971 if (op->flags & TX_RESET_MULTI_IDX) { 972 /* start multiple frame transmission with index 0 */ 973 op->currframe = 0; 974 } 975 976 if (op->flags & SETTIMER) { 977 /* set timer values */ 978 op->count = msg_head->count; 979 op->ival1 = msg_head->ival1; 980 op->ival2 = msg_head->ival2; 981 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 982 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 983 984 /* disable an active timer due to zero values? */ 985 if (!op->kt_ival1 && !op->kt_ival2) 986 hrtimer_cancel(&op->timer); 987 } 988 989 if (op->flags & STARTTIMER) { 990 hrtimer_cancel(&op->timer); 991 /* spec: send CAN frame when starting timer */ 992 op->flags |= TX_ANNOUNCE; 993 } 994 995 if (op->flags & TX_ANNOUNCE) { 996 bcm_can_tx(op); 997 if (op->count) 998 op->count--; 999 } 1000 1001 if (op->flags & STARTTIMER) 1002 bcm_tx_start_timer(op); 1003 1004 return msg_head->nframes * op->cfsiz + MHSIZ; 1005 } 1006 1007 /* 1008 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1009 */ 1010 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1011 int ifindex, struct sock *sk) 1012 { 1013 struct bcm_sock *bo = bcm_sk(sk); 1014 struct bcm_op *op; 1015 int do_rx_register; 1016 int err = 0; 1017 1018 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1019 /* be robust against wrong usage ... */ 1020 msg_head->flags |= RX_FILTER_ID; 1021 /* ignore trailing garbage */ 1022 msg_head->nframes = 0; 1023 } 1024 1025 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1026 if (msg_head->nframes > MAX_NFRAMES + 1) 1027 return -EINVAL; 1028 1029 if ((msg_head->flags & RX_RTR_FRAME) && 1030 ((msg_head->nframes != 1) || 1031 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1032 return -EINVAL; 1033 1034 /* check timeval limitations */ 1035 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1036 return -EINVAL; 1037 1038 /* check the given can_id */ 1039 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1040 if (op) { 1041 /* update existing BCM operation */ 1042 1043 /* 1044 * Do we need more space for the CAN frames than currently 1045 * allocated? -> This is a _really_ unusual use-case and 1046 * therefore (complexity / locking) it is not supported. 1047 */ 1048 if (msg_head->nframes > op->nframes) 1049 return -E2BIG; 1050 1051 if (msg_head->nframes) { 1052 /* update CAN frames content */ 1053 err = memcpy_from_msg(op->frames, msg, 1054 msg_head->nframes * op->cfsiz); 1055 if (err < 0) 1056 return err; 1057 1058 /* clear last_frames to indicate 'nothing received' */ 1059 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1060 } 1061 1062 op->nframes = msg_head->nframes; 1063 op->flags = msg_head->flags; 1064 1065 /* Only an update -> do not call can_rx_register() */ 1066 do_rx_register = 0; 1067 1068 } else { 1069 /* insert new BCM operation for the given can_id */ 1070 op = kzalloc(OPSIZ, GFP_KERNEL); 1071 if (!op) 1072 return -ENOMEM; 1073 1074 op->can_id = msg_head->can_id; 1075 op->nframes = msg_head->nframes; 1076 op->cfsiz = CFSIZ(msg_head->flags); 1077 op->flags = msg_head->flags; 1078 1079 if (msg_head->nframes > 1) { 1080 /* create array for CAN frames and copy the data */ 1081 op->frames = kmalloc_array(msg_head->nframes, 1082 op->cfsiz, 1083 GFP_KERNEL); 1084 if (!op->frames) { 1085 kfree(op); 1086 return -ENOMEM; 1087 } 1088 1089 /* create and init array for received CAN frames */ 1090 op->last_frames = kcalloc(msg_head->nframes, 1091 op->cfsiz, 1092 GFP_KERNEL); 1093 if (!op->last_frames) { 1094 kfree(op->frames); 1095 kfree(op); 1096 return -ENOMEM; 1097 } 1098 1099 } else { 1100 op->frames = &op->sframe; 1101 op->last_frames = &op->last_sframe; 1102 } 1103 1104 if (msg_head->nframes) { 1105 err = memcpy_from_msg(op->frames, msg, 1106 msg_head->nframes * op->cfsiz); 1107 if (err < 0) { 1108 if (op->frames != &op->sframe) 1109 kfree(op->frames); 1110 if (op->last_frames != &op->last_sframe) 1111 kfree(op->last_frames); 1112 kfree(op); 1113 return err; 1114 } 1115 } 1116 1117 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1118 op->sk = sk; 1119 op->ifindex = ifindex; 1120 1121 /* ifindex for timeout events w/o previous frame reception */ 1122 op->rx_ifindex = ifindex; 1123 1124 /* initialize uninitialized (kzalloc) structure */ 1125 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 1126 HRTIMER_MODE_REL_SOFT); 1127 op->timer.function = bcm_rx_timeout_handler; 1128 1129 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 1130 HRTIMER_MODE_REL_SOFT); 1131 op->thrtimer.function = bcm_rx_thr_handler; 1132 1133 /* add this bcm_op to the list of the rx_ops */ 1134 list_add(&op->list, &bo->rx_ops); 1135 1136 /* call can_rx_register() */ 1137 do_rx_register = 1; 1138 1139 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1140 1141 /* check flags */ 1142 1143 if (op->flags & RX_RTR_FRAME) { 1144 struct canfd_frame *frame0 = op->frames; 1145 1146 /* no timers in RTR-mode */ 1147 hrtimer_cancel(&op->thrtimer); 1148 hrtimer_cancel(&op->timer); 1149 1150 /* 1151 * funny feature in RX(!)_SETUP only for RTR-mode: 1152 * copy can_id into frame BUT without RTR-flag to 1153 * prevent a full-load-loopback-test ... ;-] 1154 */ 1155 if ((op->flags & TX_CP_CAN_ID) || 1156 (frame0->can_id == op->can_id)) 1157 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1158 1159 } else { 1160 if (op->flags & SETTIMER) { 1161 1162 /* set timer value */ 1163 op->ival1 = msg_head->ival1; 1164 op->ival2 = msg_head->ival2; 1165 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1166 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1167 1168 /* disable an active timer due to zero value? */ 1169 if (!op->kt_ival1) 1170 hrtimer_cancel(&op->timer); 1171 1172 /* 1173 * In any case cancel the throttle timer, flush 1174 * potentially blocked msgs and reset throttle handling 1175 */ 1176 op->kt_lastmsg = 0; 1177 hrtimer_cancel(&op->thrtimer); 1178 bcm_rx_thr_flush(op); 1179 } 1180 1181 if ((op->flags & STARTTIMER) && op->kt_ival1) 1182 hrtimer_start(&op->timer, op->kt_ival1, 1183 HRTIMER_MODE_REL_SOFT); 1184 } 1185 1186 /* now we can register for can_ids, if we added a new bcm_op */ 1187 if (do_rx_register) { 1188 if (ifindex) { 1189 struct net_device *dev; 1190 1191 dev = dev_get_by_index(sock_net(sk), ifindex); 1192 if (dev) { 1193 err = can_rx_register(sock_net(sk), dev, 1194 op->can_id, 1195 REGMASK(op->can_id), 1196 bcm_rx_handler, op, 1197 "bcm", sk); 1198 1199 op->rx_reg_dev = dev; 1200 dev_put(dev); 1201 } 1202 1203 } else 1204 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1205 REGMASK(op->can_id), 1206 bcm_rx_handler, op, "bcm", sk); 1207 if (err) { 1208 /* this bcm rx op is broken -> remove it */ 1209 list_del(&op->list); 1210 bcm_remove_op(op); 1211 return err; 1212 } 1213 } 1214 1215 return msg_head->nframes * op->cfsiz + MHSIZ; 1216 } 1217 1218 /* 1219 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1220 */ 1221 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1222 int cfsiz) 1223 { 1224 struct sk_buff *skb; 1225 struct net_device *dev; 1226 int err; 1227 1228 /* we need a real device to send frames */ 1229 if (!ifindex) 1230 return -ENODEV; 1231 1232 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1233 if (!skb) 1234 return -ENOMEM; 1235 1236 can_skb_reserve(skb); 1237 1238 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1239 if (err < 0) { 1240 kfree_skb(skb); 1241 return err; 1242 } 1243 1244 dev = dev_get_by_index(sock_net(sk), ifindex); 1245 if (!dev) { 1246 kfree_skb(skb); 1247 return -ENODEV; 1248 } 1249 1250 can_skb_prv(skb)->ifindex = dev->ifindex; 1251 can_skb_prv(skb)->skbcnt = 0; 1252 skb->dev = dev; 1253 can_skb_set_owner(skb, sk); 1254 err = can_send(skb, 1); /* send with loopback */ 1255 dev_put(dev); 1256 1257 if (err) 1258 return err; 1259 1260 return cfsiz + MHSIZ; 1261 } 1262 1263 /* 1264 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1265 */ 1266 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1267 { 1268 struct sock *sk = sock->sk; 1269 struct bcm_sock *bo = bcm_sk(sk); 1270 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1271 struct bcm_msg_head msg_head; 1272 int cfsiz; 1273 int ret; /* read bytes or error codes as return value */ 1274 1275 if (!bo->bound) 1276 return -ENOTCONN; 1277 1278 /* check for valid message length from userspace */ 1279 if (size < MHSIZ) 1280 return -EINVAL; 1281 1282 /* read message head information */ 1283 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1284 if (ret < 0) 1285 return ret; 1286 1287 cfsiz = CFSIZ(msg_head.flags); 1288 if ((size - MHSIZ) % cfsiz) 1289 return -EINVAL; 1290 1291 /* check for alternative ifindex for this bcm_op */ 1292 1293 if (!ifindex && msg->msg_name) { 1294 /* no bound device as default => check msg_name */ 1295 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1296 1297 if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex)) 1298 return -EINVAL; 1299 1300 if (addr->can_family != AF_CAN) 1301 return -EINVAL; 1302 1303 /* ifindex from sendto() */ 1304 ifindex = addr->can_ifindex; 1305 1306 if (ifindex) { 1307 struct net_device *dev; 1308 1309 dev = dev_get_by_index(sock_net(sk), ifindex); 1310 if (!dev) 1311 return -ENODEV; 1312 1313 if (dev->type != ARPHRD_CAN) { 1314 dev_put(dev); 1315 return -ENODEV; 1316 } 1317 1318 dev_put(dev); 1319 } 1320 } 1321 1322 lock_sock(sk); 1323 1324 switch (msg_head.opcode) { 1325 1326 case TX_SETUP: 1327 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1328 break; 1329 1330 case RX_SETUP: 1331 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1332 break; 1333 1334 case TX_DELETE: 1335 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1336 ret = MHSIZ; 1337 else 1338 ret = -EINVAL; 1339 break; 1340 1341 case RX_DELETE: 1342 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1343 ret = MHSIZ; 1344 else 1345 ret = -EINVAL; 1346 break; 1347 1348 case TX_READ: 1349 /* reuse msg_head for the reply to TX_READ */ 1350 msg_head.opcode = TX_STATUS; 1351 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1352 break; 1353 1354 case RX_READ: 1355 /* reuse msg_head for the reply to RX_READ */ 1356 msg_head.opcode = RX_STATUS; 1357 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1358 break; 1359 1360 case TX_SEND: 1361 /* we need exactly one CAN frame behind the msg head */ 1362 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1363 ret = -EINVAL; 1364 else 1365 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1366 break; 1367 1368 default: 1369 ret = -EINVAL; 1370 break; 1371 } 1372 1373 release_sock(sk); 1374 1375 return ret; 1376 } 1377 1378 /* 1379 * notification handler for netdevice status changes 1380 */ 1381 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1382 void *ptr) 1383 { 1384 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1385 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); 1386 struct sock *sk = &bo->sk; 1387 struct bcm_op *op; 1388 int notify_enodev = 0; 1389 1390 if (!net_eq(dev_net(dev), sock_net(sk))) 1391 return NOTIFY_DONE; 1392 1393 if (dev->type != ARPHRD_CAN) 1394 return NOTIFY_DONE; 1395 1396 switch (msg) { 1397 1398 case NETDEV_UNREGISTER: 1399 lock_sock(sk); 1400 1401 /* remove device specific receive entries */ 1402 list_for_each_entry(op, &bo->rx_ops, list) 1403 if (op->rx_reg_dev == dev) 1404 bcm_rx_unreg(dev, op); 1405 1406 /* remove device reference, if this is our bound device */ 1407 if (bo->bound && bo->ifindex == dev->ifindex) { 1408 bo->bound = 0; 1409 bo->ifindex = 0; 1410 notify_enodev = 1; 1411 } 1412 1413 release_sock(sk); 1414 1415 if (notify_enodev) { 1416 sk->sk_err = ENODEV; 1417 if (!sock_flag(sk, SOCK_DEAD)) 1418 sk->sk_error_report(sk); 1419 } 1420 break; 1421 1422 case NETDEV_DOWN: 1423 if (bo->bound && bo->ifindex == dev->ifindex) { 1424 sk->sk_err = ENETDOWN; 1425 if (!sock_flag(sk, SOCK_DEAD)) 1426 sk->sk_error_report(sk); 1427 } 1428 } 1429 1430 return NOTIFY_DONE; 1431 } 1432 1433 /* 1434 * initial settings for all BCM sockets to be set at socket creation time 1435 */ 1436 static int bcm_init(struct sock *sk) 1437 { 1438 struct bcm_sock *bo = bcm_sk(sk); 1439 1440 bo->bound = 0; 1441 bo->ifindex = 0; 1442 bo->dropped_usr_msgs = 0; 1443 bo->bcm_proc_read = NULL; 1444 1445 INIT_LIST_HEAD(&bo->tx_ops); 1446 INIT_LIST_HEAD(&bo->rx_ops); 1447 1448 /* set notifier */ 1449 bo->notifier.notifier_call = bcm_notifier; 1450 1451 register_netdevice_notifier(&bo->notifier); 1452 1453 return 0; 1454 } 1455 1456 /* 1457 * standard socket functions 1458 */ 1459 static int bcm_release(struct socket *sock) 1460 { 1461 struct sock *sk = sock->sk; 1462 struct net *net; 1463 struct bcm_sock *bo; 1464 struct bcm_op *op, *next; 1465 1466 if (!sk) 1467 return 0; 1468 1469 net = sock_net(sk); 1470 bo = bcm_sk(sk); 1471 1472 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1473 1474 unregister_netdevice_notifier(&bo->notifier); 1475 1476 lock_sock(sk); 1477 1478 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1479 bcm_remove_op(op); 1480 1481 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1482 /* 1483 * Don't care if we're bound or not (due to netdev problems) 1484 * can_rx_unregister() is always a save thing to do here. 1485 */ 1486 if (op->ifindex) { 1487 /* 1488 * Only remove subscriptions that had not 1489 * been removed due to NETDEV_UNREGISTER 1490 * in bcm_notifier() 1491 */ 1492 if (op->rx_reg_dev) { 1493 struct net_device *dev; 1494 1495 dev = dev_get_by_index(net, op->ifindex); 1496 if (dev) { 1497 bcm_rx_unreg(dev, op); 1498 dev_put(dev); 1499 } 1500 } 1501 } else 1502 can_rx_unregister(net, NULL, op->can_id, 1503 REGMASK(op->can_id), 1504 bcm_rx_handler, op); 1505 1506 bcm_remove_op(op); 1507 } 1508 1509 #if IS_ENABLED(CONFIG_PROC_FS) 1510 /* remove procfs entry */ 1511 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1512 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1513 #endif /* CONFIG_PROC_FS */ 1514 1515 /* remove device reference */ 1516 if (bo->bound) { 1517 bo->bound = 0; 1518 bo->ifindex = 0; 1519 } 1520 1521 sock_orphan(sk); 1522 sock->sk = NULL; 1523 1524 release_sock(sk); 1525 sock_put(sk); 1526 1527 return 0; 1528 } 1529 1530 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1531 int flags) 1532 { 1533 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1534 struct sock *sk = sock->sk; 1535 struct bcm_sock *bo = bcm_sk(sk); 1536 struct net *net = sock_net(sk); 1537 int ret = 0; 1538 1539 if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex)) 1540 return -EINVAL; 1541 1542 lock_sock(sk); 1543 1544 if (bo->bound) { 1545 ret = -EISCONN; 1546 goto fail; 1547 } 1548 1549 /* bind a device to this socket */ 1550 if (addr->can_ifindex) { 1551 struct net_device *dev; 1552 1553 dev = dev_get_by_index(net, addr->can_ifindex); 1554 if (!dev) { 1555 ret = -ENODEV; 1556 goto fail; 1557 } 1558 if (dev->type != ARPHRD_CAN) { 1559 dev_put(dev); 1560 ret = -ENODEV; 1561 goto fail; 1562 } 1563 1564 bo->ifindex = dev->ifindex; 1565 dev_put(dev); 1566 1567 } else { 1568 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1569 bo->ifindex = 0; 1570 } 1571 1572 #if IS_ENABLED(CONFIG_PROC_FS) 1573 if (net->can.bcmproc_dir) { 1574 /* unique socket address as filename */ 1575 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1576 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1577 net->can.bcmproc_dir, 1578 bcm_proc_show, sk); 1579 if (!bo->bcm_proc_read) { 1580 ret = -ENOMEM; 1581 goto fail; 1582 } 1583 } 1584 #endif /* CONFIG_PROC_FS */ 1585 1586 bo->bound = 1; 1587 1588 fail: 1589 release_sock(sk); 1590 1591 return ret; 1592 } 1593 1594 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1595 int flags) 1596 { 1597 struct sock *sk = sock->sk; 1598 struct sk_buff *skb; 1599 int error = 0; 1600 int noblock; 1601 int err; 1602 1603 noblock = flags & MSG_DONTWAIT; 1604 flags &= ~MSG_DONTWAIT; 1605 skb = skb_recv_datagram(sk, flags, noblock, &error); 1606 if (!skb) 1607 return error; 1608 1609 if (skb->len < size) 1610 size = skb->len; 1611 1612 err = memcpy_to_msg(msg, skb->data, size); 1613 if (err < 0) { 1614 skb_free_datagram(sk, skb); 1615 return err; 1616 } 1617 1618 sock_recv_ts_and_drops(msg, sk, skb); 1619 1620 if (msg->msg_name) { 1621 __sockaddr_check_size(sizeof(struct sockaddr_can)); 1622 msg->msg_namelen = sizeof(struct sockaddr_can); 1623 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1624 } 1625 1626 skb_free_datagram(sk, skb); 1627 1628 return size; 1629 } 1630 1631 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1632 unsigned long arg) 1633 { 1634 /* no ioctls for socket layer -> hand it down to NIC layer */ 1635 return -ENOIOCTLCMD; 1636 } 1637 1638 static const struct proto_ops bcm_ops = { 1639 .family = PF_CAN, 1640 .release = bcm_release, 1641 .bind = sock_no_bind, 1642 .connect = bcm_connect, 1643 .socketpair = sock_no_socketpair, 1644 .accept = sock_no_accept, 1645 .getname = sock_no_getname, 1646 .poll = datagram_poll, 1647 .ioctl = bcm_sock_no_ioctlcmd, 1648 .gettstamp = sock_gettstamp, 1649 .listen = sock_no_listen, 1650 .shutdown = sock_no_shutdown, 1651 .sendmsg = bcm_sendmsg, 1652 .recvmsg = bcm_recvmsg, 1653 .mmap = sock_no_mmap, 1654 .sendpage = sock_no_sendpage, 1655 }; 1656 1657 static struct proto bcm_proto __read_mostly = { 1658 .name = "CAN_BCM", 1659 .owner = THIS_MODULE, 1660 .obj_size = sizeof(struct bcm_sock), 1661 .init = bcm_init, 1662 }; 1663 1664 static const struct can_proto bcm_can_proto = { 1665 .type = SOCK_DGRAM, 1666 .protocol = CAN_BCM, 1667 .ops = &bcm_ops, 1668 .prot = &bcm_proto, 1669 }; 1670 1671 static int canbcm_pernet_init(struct net *net) 1672 { 1673 #if IS_ENABLED(CONFIG_PROC_FS) 1674 /* create /proc/net/can-bcm directory */ 1675 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1676 #endif /* CONFIG_PROC_FS */ 1677 1678 return 0; 1679 } 1680 1681 static void canbcm_pernet_exit(struct net *net) 1682 { 1683 #if IS_ENABLED(CONFIG_PROC_FS) 1684 /* remove /proc/net/can-bcm directory */ 1685 if (net->can.bcmproc_dir) 1686 remove_proc_entry("can-bcm", net->proc_net); 1687 #endif /* CONFIG_PROC_FS */ 1688 } 1689 1690 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1691 .init = canbcm_pernet_init, 1692 .exit = canbcm_pernet_exit, 1693 }; 1694 1695 static int __init bcm_module_init(void) 1696 { 1697 int err; 1698 1699 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"); 1700 1701 err = can_proto_register(&bcm_can_proto); 1702 if (err < 0) { 1703 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1704 return err; 1705 } 1706 1707 register_pernet_subsys(&canbcm_pernet_ops); 1708 return 0; 1709 } 1710 1711 static void __exit bcm_module_exit(void) 1712 { 1713 can_proto_unregister(&bcm_can_proto); 1714 unregister_pernet_subsys(&canbcm_pernet_ops); 1715 } 1716 1717 module_init(bcm_module_init); 1718 module_exit(bcm_module_exit); 1719