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 #define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) 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 list_head 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 LIST_HEAD(bcm_notifier_list); 137 static DEFINE_SPINLOCK(bcm_notifier_lock); 138 static struct bcm_sock *bcm_busy_notifier; 139 140 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 141 { 142 return (struct bcm_sock *)sk; 143 } 144 145 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 146 { 147 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 148 } 149 150 /* check limitations for timeval provided by user */ 151 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 152 { 153 if ((msg_head->ival1.tv_sec < 0) || 154 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 155 (msg_head->ival1.tv_usec < 0) || 156 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 157 (msg_head->ival2.tv_sec < 0) || 158 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 159 (msg_head->ival2.tv_usec < 0) || 160 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 161 return true; 162 163 return false; 164 } 165 166 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 167 #define OPSIZ sizeof(struct bcm_op) 168 #define MHSIZ sizeof(struct bcm_msg_head) 169 170 /* 171 * procfs functions 172 */ 173 #if IS_ENABLED(CONFIG_PROC_FS) 174 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 175 { 176 struct net_device *dev; 177 178 if (!ifindex) 179 return "any"; 180 181 rcu_read_lock(); 182 dev = dev_get_by_index_rcu(net, ifindex); 183 if (dev) 184 strcpy(result, dev->name); 185 else 186 strcpy(result, "???"); 187 rcu_read_unlock(); 188 189 return result; 190 } 191 192 static int bcm_proc_show(struct seq_file *m, void *v) 193 { 194 char ifname[IFNAMSIZ]; 195 struct net *net = m->private; 196 struct sock *sk = (struct sock *)pde_data(m->file->f_inode); 197 struct bcm_sock *bo = bcm_sk(sk); 198 struct bcm_op *op; 199 200 seq_printf(m, ">>> socket %pK", sk->sk_socket); 201 seq_printf(m, " / sk %pK", sk); 202 seq_printf(m, " / bo %pK", bo); 203 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 204 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 205 seq_printf(m, " <<<\n"); 206 207 list_for_each_entry(op, &bo->rx_ops, list) { 208 209 unsigned long reduction; 210 211 /* print only active entries & prevent division by zero */ 212 if (!op->frames_abs) 213 continue; 214 215 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 216 bcm_proc_getifname(net, ifname, op->ifindex)); 217 218 if (op->flags & CAN_FD_FRAME) 219 seq_printf(m, "(%u)", op->nframes); 220 else 221 seq_printf(m, "[%u]", op->nframes); 222 223 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 224 225 if (op->kt_ival1) 226 seq_printf(m, "timeo=%lld ", 227 (long long)ktime_to_us(op->kt_ival1)); 228 229 if (op->kt_ival2) 230 seq_printf(m, "thr=%lld ", 231 (long long)ktime_to_us(op->kt_ival2)); 232 233 seq_printf(m, "# recv %ld (%ld) => reduction: ", 234 op->frames_filtered, op->frames_abs); 235 236 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 237 238 seq_printf(m, "%s%ld%%\n", 239 (reduction == 100) ? "near " : "", reduction); 240 } 241 242 list_for_each_entry(op, &bo->tx_ops, list) { 243 244 seq_printf(m, "tx_op: %03X %s ", op->can_id, 245 bcm_proc_getifname(net, ifname, op->ifindex)); 246 247 if (op->flags & CAN_FD_FRAME) 248 seq_printf(m, "(%u) ", op->nframes); 249 else 250 seq_printf(m, "[%u] ", op->nframes); 251 252 if (op->kt_ival1) 253 seq_printf(m, "t1=%lld ", 254 (long long)ktime_to_us(op->kt_ival1)); 255 256 if (op->kt_ival2) 257 seq_printf(m, "t2=%lld ", 258 (long long)ktime_to_us(op->kt_ival2)); 259 260 seq_printf(m, "# sent %ld\n", op->frames_abs); 261 } 262 seq_putc(m, '\n'); 263 return 0; 264 } 265 #endif /* CONFIG_PROC_FS */ 266 267 /* 268 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 269 * of the given bcm tx op 270 */ 271 static void bcm_can_tx(struct bcm_op *op) 272 { 273 struct sk_buff *skb; 274 struct net_device *dev; 275 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 276 277 /* no target device? => exit */ 278 if (!op->ifindex) 279 return; 280 281 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 282 if (!dev) { 283 /* RFC: should this bcm_op remove itself here? */ 284 return; 285 } 286 287 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 288 if (!skb) 289 goto out; 290 291 can_skb_reserve(skb); 292 can_skb_prv(skb)->ifindex = dev->ifindex; 293 can_skb_prv(skb)->skbcnt = 0; 294 295 skb_put_data(skb, cf, op->cfsiz); 296 297 /* send with loopback */ 298 skb->dev = dev; 299 can_skb_set_owner(skb, op->sk); 300 can_send(skb, 1); 301 302 /* update statistics */ 303 op->currframe++; 304 op->frames_abs++; 305 306 /* reached last frame? */ 307 if (op->currframe >= op->nframes) 308 op->currframe = 0; 309 out: 310 dev_put(dev); 311 } 312 313 /* 314 * bcm_send_to_user - send a BCM message to the userspace 315 * (consisting of bcm_msg_head + x CAN frames) 316 */ 317 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 318 struct canfd_frame *frames, int has_timestamp) 319 { 320 struct sk_buff *skb; 321 struct canfd_frame *firstframe; 322 struct sockaddr_can *addr; 323 struct sock *sk = op->sk; 324 unsigned int datalen = head->nframes * op->cfsiz; 325 int err; 326 327 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 328 if (!skb) 329 return; 330 331 skb_put_data(skb, head, sizeof(*head)); 332 333 if (head->nframes) { 334 /* CAN frames starting here */ 335 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 336 337 skb_put_data(skb, frames, datalen); 338 339 /* 340 * the BCM uses the flags-element of the canfd_frame 341 * structure for internal purposes. This is only 342 * relevant for updates that are generated by the 343 * BCM, where nframes is 1 344 */ 345 if (head->nframes == 1) 346 firstframe->flags &= BCM_CAN_FLAGS_MASK; 347 } 348 349 if (has_timestamp) { 350 /* restore rx timestamp */ 351 skb->tstamp = op->rx_stamp; 352 } 353 354 /* 355 * Put the datagram to the queue so that bcm_recvmsg() can 356 * get it from there. We need to pass the interface index to 357 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 358 * containing the interface index. 359 */ 360 361 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 362 addr = (struct sockaddr_can *)skb->cb; 363 memset(addr, 0, sizeof(*addr)); 364 addr->can_family = AF_CAN; 365 addr->can_ifindex = op->rx_ifindex; 366 367 err = sock_queue_rcv_skb(sk, skb); 368 if (err < 0) { 369 struct bcm_sock *bo = bcm_sk(sk); 370 371 kfree_skb(skb); 372 /* don't care about overflows in this statistic */ 373 bo->dropped_usr_msgs++; 374 } 375 } 376 377 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt) 378 { 379 ktime_t ival; 380 381 if (op->kt_ival1 && op->count) 382 ival = op->kt_ival1; 383 else if (op->kt_ival2) 384 ival = op->kt_ival2; 385 else 386 return false; 387 388 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival)); 389 return true; 390 } 391 392 static void bcm_tx_start_timer(struct bcm_op *op) 393 { 394 if (bcm_tx_set_expiry(op, &op->timer)) 395 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT); 396 } 397 398 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */ 399 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 400 { 401 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 402 struct bcm_msg_head msg_head; 403 404 if (op->kt_ival1 && (op->count > 0)) { 405 op->count--; 406 if (!op->count && (op->flags & TX_COUNTEVT)) { 407 408 /* create notification to user */ 409 memset(&msg_head, 0, sizeof(msg_head)); 410 msg_head.opcode = TX_EXPIRED; 411 msg_head.flags = op->flags; 412 msg_head.count = op->count; 413 msg_head.ival1 = op->ival1; 414 msg_head.ival2 = op->ival2; 415 msg_head.can_id = op->can_id; 416 msg_head.nframes = 0; 417 418 bcm_send_to_user(op, &msg_head, NULL, 0); 419 } 420 bcm_can_tx(op); 421 422 } else if (op->kt_ival2) { 423 bcm_can_tx(op); 424 } 425 426 return bcm_tx_set_expiry(op, &op->timer) ? 427 HRTIMER_RESTART : HRTIMER_NORESTART; 428 } 429 430 /* 431 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 432 */ 433 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 434 { 435 struct bcm_msg_head head; 436 437 /* update statistics */ 438 op->frames_filtered++; 439 440 /* prevent statistics overflow */ 441 if (op->frames_filtered > ULONG_MAX/100) 442 op->frames_filtered = op->frames_abs = 0; 443 444 /* this element is not throttled anymore */ 445 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 446 447 memset(&head, 0, sizeof(head)); 448 head.opcode = RX_CHANGED; 449 head.flags = op->flags; 450 head.count = op->count; 451 head.ival1 = op->ival1; 452 head.ival2 = op->ival2; 453 head.can_id = op->can_id; 454 head.nframes = 1; 455 456 bcm_send_to_user(op, &head, data, 1); 457 } 458 459 /* 460 * bcm_rx_update_and_send - process a detected relevant receive content change 461 * 1. update the last received data 462 * 2. send a notification to the user (if possible) 463 */ 464 static void bcm_rx_update_and_send(struct bcm_op *op, 465 struct canfd_frame *lastdata, 466 const struct canfd_frame *rxdata) 467 { 468 memcpy(lastdata, rxdata, op->cfsiz); 469 470 /* mark as used and throttled by default */ 471 lastdata->flags |= (RX_RECV|RX_THR); 472 473 /* throttling mode inactive ? */ 474 if (!op->kt_ival2) { 475 /* send RX_CHANGED to the user immediately */ 476 bcm_rx_changed(op, lastdata); 477 return; 478 } 479 480 /* with active throttling timer we are just done here */ 481 if (hrtimer_active(&op->thrtimer)) 482 return; 483 484 /* first reception with enabled throttling mode */ 485 if (!op->kt_lastmsg) 486 goto rx_changed_settime; 487 488 /* got a second frame inside a potential throttle period? */ 489 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 490 ktime_to_us(op->kt_ival2)) { 491 /* do not send the saved data - only start throttle timer */ 492 hrtimer_start(&op->thrtimer, 493 ktime_add(op->kt_lastmsg, op->kt_ival2), 494 HRTIMER_MODE_ABS_SOFT); 495 return; 496 } 497 498 /* the gap was that big, that throttling was not needed here */ 499 rx_changed_settime: 500 bcm_rx_changed(op, lastdata); 501 op->kt_lastmsg = ktime_get(); 502 } 503 504 /* 505 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 506 * received data stored in op->last_frames[] 507 */ 508 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 509 const struct canfd_frame *rxdata) 510 { 511 struct canfd_frame *cf = op->frames + op->cfsiz * index; 512 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 513 int i; 514 515 /* 516 * no one uses the MSBs of flags for comparison, 517 * so we use it here to detect the first time of reception 518 */ 519 520 if (!(lcf->flags & RX_RECV)) { 521 /* received data for the first time => send update to user */ 522 bcm_rx_update_and_send(op, lcf, rxdata); 523 return; 524 } 525 526 /* do a real check in CAN frame data section */ 527 for (i = 0; i < rxdata->len; i += 8) { 528 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 529 (get_u64(cf, i) & get_u64(lcf, i))) { 530 bcm_rx_update_and_send(op, lcf, rxdata); 531 return; 532 } 533 } 534 535 if (op->flags & RX_CHECK_DLC) { 536 /* do a real check in CAN frame length */ 537 if (rxdata->len != lcf->len) { 538 bcm_rx_update_and_send(op, lcf, rxdata); 539 return; 540 } 541 } 542 } 543 544 /* 545 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 546 */ 547 static void bcm_rx_starttimer(struct bcm_op *op) 548 { 549 if (op->flags & RX_NO_AUTOTIMER) 550 return; 551 552 if (op->kt_ival1) 553 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT); 554 } 555 556 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */ 557 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 558 { 559 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 560 struct bcm_msg_head msg_head; 561 562 /* if user wants to be informed, when cyclic CAN-Messages come back */ 563 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 564 /* clear received CAN frames to indicate 'nothing received' */ 565 memset(op->last_frames, 0, op->nframes * op->cfsiz); 566 } 567 568 /* create notification to user */ 569 memset(&msg_head, 0, sizeof(msg_head)); 570 msg_head.opcode = RX_TIMEOUT; 571 msg_head.flags = op->flags; 572 msg_head.count = op->count; 573 msg_head.ival1 = op->ival1; 574 msg_head.ival2 = op->ival2; 575 msg_head.can_id = op->can_id; 576 msg_head.nframes = 0; 577 578 bcm_send_to_user(op, &msg_head, NULL, 0); 579 580 return HRTIMER_NORESTART; 581 } 582 583 /* 584 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 585 */ 586 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index) 587 { 588 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 589 590 if ((op->last_frames) && (lcf->flags & RX_THR)) { 591 bcm_rx_changed(op, lcf); 592 return 1; 593 } 594 return 0; 595 } 596 597 /* 598 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 599 */ 600 static int bcm_rx_thr_flush(struct bcm_op *op) 601 { 602 int updated = 0; 603 604 if (op->nframes > 1) { 605 unsigned int i; 606 607 /* for MUX filter we start at index 1 */ 608 for (i = 1; i < op->nframes; i++) 609 updated += bcm_rx_do_flush(op, i); 610 611 } else { 612 /* for RX_FILTER_ID and simple filter */ 613 updated += bcm_rx_do_flush(op, 0); 614 } 615 616 return updated; 617 } 618 619 /* 620 * bcm_rx_thr_handler - the time for blocked content updates is over now: 621 * Check for throttled data and send it to the userspace 622 */ 623 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 624 { 625 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 626 627 if (bcm_rx_thr_flush(op)) { 628 hrtimer_forward_now(hrtimer, op->kt_ival2); 629 return HRTIMER_RESTART; 630 } else { 631 /* rearm throttle handling */ 632 op->kt_lastmsg = 0; 633 return HRTIMER_NORESTART; 634 } 635 } 636 637 /* 638 * bcm_rx_handler - handle a CAN frame reception 639 */ 640 static void bcm_rx_handler(struct sk_buff *skb, void *data) 641 { 642 struct bcm_op *op = (struct bcm_op *)data; 643 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 644 unsigned int i; 645 646 if (op->can_id != rxframe->can_id) 647 return; 648 649 /* make sure to handle the correct frame type (CAN / CAN FD) */ 650 if (skb->len != op->cfsiz) 651 return; 652 653 /* disable timeout */ 654 hrtimer_cancel(&op->timer); 655 656 /* save rx timestamp */ 657 op->rx_stamp = skb->tstamp; 658 /* save originator for recvfrom() */ 659 op->rx_ifindex = skb->dev->ifindex; 660 /* update statistics */ 661 op->frames_abs++; 662 663 if (op->flags & RX_RTR_FRAME) { 664 /* send reply for RTR-request (placed in op->frames[0]) */ 665 bcm_can_tx(op); 666 return; 667 } 668 669 if (op->flags & RX_FILTER_ID) { 670 /* the easiest case */ 671 bcm_rx_update_and_send(op, op->last_frames, rxframe); 672 goto rx_starttimer; 673 } 674 675 if (op->nframes == 1) { 676 /* simple compare with index 0 */ 677 bcm_rx_cmp_to_index(op, 0, rxframe); 678 goto rx_starttimer; 679 } 680 681 if (op->nframes > 1) { 682 /* 683 * multiplex compare 684 * 685 * find the first multiplex mask that fits. 686 * Remark: The MUX-mask is stored in index 0 - but only the 687 * first 64 bits of the frame data[] are relevant (CAN FD) 688 */ 689 690 for (i = 1; i < op->nframes; i++) { 691 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 692 (get_u64(op->frames, 0) & 693 get_u64(op->frames + op->cfsiz * i, 0))) { 694 bcm_rx_cmp_to_index(op, i, rxframe); 695 break; 696 } 697 } 698 } 699 700 rx_starttimer: 701 bcm_rx_starttimer(op); 702 } 703 704 /* 705 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 706 */ 707 static struct bcm_op *bcm_find_op(struct list_head *ops, 708 struct bcm_msg_head *mh, int ifindex) 709 { 710 struct bcm_op *op; 711 712 list_for_each_entry(op, ops, list) { 713 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 714 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 715 return op; 716 } 717 718 return NULL; 719 } 720 721 static void bcm_remove_op(struct bcm_op *op) 722 { 723 hrtimer_cancel(&op->timer); 724 hrtimer_cancel(&op->thrtimer); 725 726 if ((op->frames) && (op->frames != &op->sframe)) 727 kfree(op->frames); 728 729 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 730 kfree(op->last_frames); 731 732 kfree(op); 733 } 734 735 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 736 { 737 if (op->rx_reg_dev == dev) { 738 can_rx_unregister(dev_net(dev), dev, op->can_id, 739 REGMASK(op->can_id), bcm_rx_handler, op); 740 741 /* mark as removed subscription */ 742 op->rx_reg_dev = NULL; 743 } else 744 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 745 "mismatch %p %p\n", op->rx_reg_dev, dev); 746 } 747 748 /* 749 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 750 */ 751 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 752 int ifindex) 753 { 754 struct bcm_op *op, *n; 755 756 list_for_each_entry_safe(op, n, ops, list) { 757 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 758 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 759 760 /* 761 * Don't care if we're bound or not (due to netdev 762 * problems) can_rx_unregister() is always a save 763 * thing to do here. 764 */ 765 if (op->ifindex) { 766 /* 767 * Only remove subscriptions that had not 768 * been removed due to NETDEV_UNREGISTER 769 * in bcm_notifier() 770 */ 771 if (op->rx_reg_dev) { 772 struct net_device *dev; 773 774 dev = dev_get_by_index(sock_net(op->sk), 775 op->ifindex); 776 if (dev) { 777 bcm_rx_unreg(dev, op); 778 dev_put(dev); 779 } 780 } 781 } else 782 can_rx_unregister(sock_net(op->sk), NULL, 783 op->can_id, 784 REGMASK(op->can_id), 785 bcm_rx_handler, op); 786 787 list_del(&op->list); 788 synchronize_rcu(); 789 bcm_remove_op(op); 790 return 1; /* done */ 791 } 792 } 793 794 return 0; /* not found */ 795 } 796 797 /* 798 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 799 */ 800 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 801 int ifindex) 802 { 803 struct bcm_op *op, *n; 804 805 list_for_each_entry_safe(op, n, ops, list) { 806 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 807 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 808 list_del(&op->list); 809 bcm_remove_op(op); 810 return 1; /* done */ 811 } 812 } 813 814 return 0; /* not found */ 815 } 816 817 /* 818 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 819 */ 820 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 821 int ifindex) 822 { 823 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 824 825 if (!op) 826 return -EINVAL; 827 828 /* put current values into msg_head */ 829 msg_head->flags = op->flags; 830 msg_head->count = op->count; 831 msg_head->ival1 = op->ival1; 832 msg_head->ival2 = op->ival2; 833 msg_head->nframes = op->nframes; 834 835 bcm_send_to_user(op, msg_head, op->frames, 0); 836 837 return MHSIZ; 838 } 839 840 /* 841 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 842 */ 843 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 844 int ifindex, struct sock *sk) 845 { 846 struct bcm_sock *bo = bcm_sk(sk); 847 struct bcm_op *op; 848 struct canfd_frame *cf; 849 unsigned int i; 850 int err; 851 852 /* we need a real device to send frames */ 853 if (!ifindex) 854 return -ENODEV; 855 856 /* check nframes boundaries - we need at least one CAN frame */ 857 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 858 return -EINVAL; 859 860 /* check timeval limitations */ 861 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 862 return -EINVAL; 863 864 /* check the given can_id */ 865 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 866 if (op) { 867 /* update existing BCM operation */ 868 869 /* 870 * Do we need more space for the CAN frames than currently 871 * allocated? -> This is a _really_ unusual use-case and 872 * therefore (complexity / locking) it is not supported. 873 */ 874 if (msg_head->nframes > op->nframes) 875 return -E2BIG; 876 877 /* update CAN frames content */ 878 for (i = 0; i < msg_head->nframes; i++) { 879 880 cf = op->frames + op->cfsiz * i; 881 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 882 883 if (op->flags & CAN_FD_FRAME) { 884 if (cf->len > 64) 885 err = -EINVAL; 886 } else { 887 if (cf->len > 8) 888 err = -EINVAL; 889 } 890 891 if (err < 0) 892 return err; 893 894 if (msg_head->flags & TX_CP_CAN_ID) { 895 /* copy can_id into frame */ 896 cf->can_id = msg_head->can_id; 897 } 898 } 899 op->flags = msg_head->flags; 900 901 } else { 902 /* insert new BCM operation for the given can_id */ 903 904 op = kzalloc(OPSIZ, GFP_KERNEL); 905 if (!op) 906 return -ENOMEM; 907 908 op->can_id = msg_head->can_id; 909 op->cfsiz = CFSIZ(msg_head->flags); 910 op->flags = msg_head->flags; 911 912 /* create array for CAN frames and copy the data */ 913 if (msg_head->nframes > 1) { 914 op->frames = kmalloc_array(msg_head->nframes, 915 op->cfsiz, 916 GFP_KERNEL); 917 if (!op->frames) { 918 kfree(op); 919 return -ENOMEM; 920 } 921 } else 922 op->frames = &op->sframe; 923 924 for (i = 0; i < msg_head->nframes; i++) { 925 926 cf = op->frames + op->cfsiz * i; 927 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 928 929 if (op->flags & CAN_FD_FRAME) { 930 if (cf->len > 64) 931 err = -EINVAL; 932 } else { 933 if (cf->len > 8) 934 err = -EINVAL; 935 } 936 937 if (err < 0) { 938 if (op->frames != &op->sframe) 939 kfree(op->frames); 940 kfree(op); 941 return err; 942 } 943 944 if (msg_head->flags & TX_CP_CAN_ID) { 945 /* copy can_id into frame */ 946 cf->can_id = msg_head->can_id; 947 } 948 } 949 950 /* tx_ops never compare with previous received messages */ 951 op->last_frames = NULL; 952 953 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 954 op->sk = sk; 955 op->ifindex = ifindex; 956 957 /* initialize uninitialized (kzalloc) structure */ 958 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 959 HRTIMER_MODE_REL_SOFT); 960 op->timer.function = bcm_tx_timeout_handler; 961 962 /* currently unused in tx_ops */ 963 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 964 HRTIMER_MODE_REL_SOFT); 965 966 /* add this bcm_op to the list of the tx_ops */ 967 list_add(&op->list, &bo->tx_ops); 968 969 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 970 971 if (op->nframes != msg_head->nframes) { 972 op->nframes = msg_head->nframes; 973 /* start multiple frame transmission with index 0 */ 974 op->currframe = 0; 975 } 976 977 /* check flags */ 978 979 if (op->flags & TX_RESET_MULTI_IDX) { 980 /* start multiple frame transmission with index 0 */ 981 op->currframe = 0; 982 } 983 984 if (op->flags & SETTIMER) { 985 /* set timer values */ 986 op->count = msg_head->count; 987 op->ival1 = msg_head->ival1; 988 op->ival2 = msg_head->ival2; 989 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 990 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 991 992 /* disable an active timer due to zero values? */ 993 if (!op->kt_ival1 && !op->kt_ival2) 994 hrtimer_cancel(&op->timer); 995 } 996 997 if (op->flags & STARTTIMER) { 998 hrtimer_cancel(&op->timer); 999 /* spec: send CAN frame when starting timer */ 1000 op->flags |= TX_ANNOUNCE; 1001 } 1002 1003 if (op->flags & TX_ANNOUNCE) { 1004 bcm_can_tx(op); 1005 if (op->count) 1006 op->count--; 1007 } 1008 1009 if (op->flags & STARTTIMER) 1010 bcm_tx_start_timer(op); 1011 1012 return msg_head->nframes * op->cfsiz + MHSIZ; 1013 } 1014 1015 /* 1016 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1017 */ 1018 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1019 int ifindex, struct sock *sk) 1020 { 1021 struct bcm_sock *bo = bcm_sk(sk); 1022 struct bcm_op *op; 1023 int do_rx_register; 1024 int err = 0; 1025 1026 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1027 /* be robust against wrong usage ... */ 1028 msg_head->flags |= RX_FILTER_ID; 1029 /* ignore trailing garbage */ 1030 msg_head->nframes = 0; 1031 } 1032 1033 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1034 if (msg_head->nframes > MAX_NFRAMES + 1) 1035 return -EINVAL; 1036 1037 if ((msg_head->flags & RX_RTR_FRAME) && 1038 ((msg_head->nframes != 1) || 1039 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1040 return -EINVAL; 1041 1042 /* check timeval limitations */ 1043 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1044 return -EINVAL; 1045 1046 /* check the given can_id */ 1047 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1048 if (op) { 1049 /* update existing BCM operation */ 1050 1051 /* 1052 * Do we need more space for the CAN frames than currently 1053 * allocated? -> This is a _really_ unusual use-case and 1054 * therefore (complexity / locking) it is not supported. 1055 */ 1056 if (msg_head->nframes > op->nframes) 1057 return -E2BIG; 1058 1059 if (msg_head->nframes) { 1060 /* update CAN frames content */ 1061 err = memcpy_from_msg(op->frames, msg, 1062 msg_head->nframes * op->cfsiz); 1063 if (err < 0) 1064 return err; 1065 1066 /* clear last_frames to indicate 'nothing received' */ 1067 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1068 } 1069 1070 op->nframes = msg_head->nframes; 1071 op->flags = msg_head->flags; 1072 1073 /* Only an update -> do not call can_rx_register() */ 1074 do_rx_register = 0; 1075 1076 } else { 1077 /* insert new BCM operation for the given can_id */ 1078 op = kzalloc(OPSIZ, GFP_KERNEL); 1079 if (!op) 1080 return -ENOMEM; 1081 1082 op->can_id = msg_head->can_id; 1083 op->nframes = msg_head->nframes; 1084 op->cfsiz = CFSIZ(msg_head->flags); 1085 op->flags = msg_head->flags; 1086 1087 if (msg_head->nframes > 1) { 1088 /* create array for CAN frames and copy the data */ 1089 op->frames = kmalloc_array(msg_head->nframes, 1090 op->cfsiz, 1091 GFP_KERNEL); 1092 if (!op->frames) { 1093 kfree(op); 1094 return -ENOMEM; 1095 } 1096 1097 /* create and init array for received CAN frames */ 1098 op->last_frames = kcalloc(msg_head->nframes, 1099 op->cfsiz, 1100 GFP_KERNEL); 1101 if (!op->last_frames) { 1102 kfree(op->frames); 1103 kfree(op); 1104 return -ENOMEM; 1105 } 1106 1107 } else { 1108 op->frames = &op->sframe; 1109 op->last_frames = &op->last_sframe; 1110 } 1111 1112 if (msg_head->nframes) { 1113 err = memcpy_from_msg(op->frames, msg, 1114 msg_head->nframes * op->cfsiz); 1115 if (err < 0) { 1116 if (op->frames != &op->sframe) 1117 kfree(op->frames); 1118 if (op->last_frames != &op->last_sframe) 1119 kfree(op->last_frames); 1120 kfree(op); 1121 return err; 1122 } 1123 } 1124 1125 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1126 op->sk = sk; 1127 op->ifindex = ifindex; 1128 1129 /* ifindex for timeout events w/o previous frame reception */ 1130 op->rx_ifindex = ifindex; 1131 1132 /* initialize uninitialized (kzalloc) structure */ 1133 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 1134 HRTIMER_MODE_REL_SOFT); 1135 op->timer.function = bcm_rx_timeout_handler; 1136 1137 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 1138 HRTIMER_MODE_REL_SOFT); 1139 op->thrtimer.function = bcm_rx_thr_handler; 1140 1141 /* add this bcm_op to the list of the rx_ops */ 1142 list_add(&op->list, &bo->rx_ops); 1143 1144 /* call can_rx_register() */ 1145 do_rx_register = 1; 1146 1147 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1148 1149 /* check flags */ 1150 1151 if (op->flags & RX_RTR_FRAME) { 1152 struct canfd_frame *frame0 = op->frames; 1153 1154 /* no timers in RTR-mode */ 1155 hrtimer_cancel(&op->thrtimer); 1156 hrtimer_cancel(&op->timer); 1157 1158 /* 1159 * funny feature in RX(!)_SETUP only for RTR-mode: 1160 * copy can_id into frame BUT without RTR-flag to 1161 * prevent a full-load-loopback-test ... ;-] 1162 */ 1163 if ((op->flags & TX_CP_CAN_ID) || 1164 (frame0->can_id == op->can_id)) 1165 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1166 1167 } else { 1168 if (op->flags & SETTIMER) { 1169 1170 /* set timer value */ 1171 op->ival1 = msg_head->ival1; 1172 op->ival2 = msg_head->ival2; 1173 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1174 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1175 1176 /* disable an active timer due to zero value? */ 1177 if (!op->kt_ival1) 1178 hrtimer_cancel(&op->timer); 1179 1180 /* 1181 * In any case cancel the throttle timer, flush 1182 * potentially blocked msgs and reset throttle handling 1183 */ 1184 op->kt_lastmsg = 0; 1185 hrtimer_cancel(&op->thrtimer); 1186 bcm_rx_thr_flush(op); 1187 } 1188 1189 if ((op->flags & STARTTIMER) && op->kt_ival1) 1190 hrtimer_start(&op->timer, op->kt_ival1, 1191 HRTIMER_MODE_REL_SOFT); 1192 } 1193 1194 /* now we can register for can_ids, if we added a new bcm_op */ 1195 if (do_rx_register) { 1196 if (ifindex) { 1197 struct net_device *dev; 1198 1199 dev = dev_get_by_index(sock_net(sk), ifindex); 1200 if (dev) { 1201 err = can_rx_register(sock_net(sk), dev, 1202 op->can_id, 1203 REGMASK(op->can_id), 1204 bcm_rx_handler, op, 1205 "bcm", sk); 1206 1207 op->rx_reg_dev = dev; 1208 dev_put(dev); 1209 } 1210 1211 } else 1212 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1213 REGMASK(op->can_id), 1214 bcm_rx_handler, op, "bcm", sk); 1215 if (err) { 1216 /* this bcm rx op is broken -> remove it */ 1217 list_del(&op->list); 1218 bcm_remove_op(op); 1219 return err; 1220 } 1221 } 1222 1223 return msg_head->nframes * op->cfsiz + MHSIZ; 1224 } 1225 1226 /* 1227 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1228 */ 1229 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1230 int cfsiz) 1231 { 1232 struct sk_buff *skb; 1233 struct net_device *dev; 1234 int err; 1235 1236 /* we need a real device to send frames */ 1237 if (!ifindex) 1238 return -ENODEV; 1239 1240 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1241 if (!skb) 1242 return -ENOMEM; 1243 1244 can_skb_reserve(skb); 1245 1246 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1247 if (err < 0) { 1248 kfree_skb(skb); 1249 return err; 1250 } 1251 1252 dev = dev_get_by_index(sock_net(sk), ifindex); 1253 if (!dev) { 1254 kfree_skb(skb); 1255 return -ENODEV; 1256 } 1257 1258 can_skb_prv(skb)->ifindex = dev->ifindex; 1259 can_skb_prv(skb)->skbcnt = 0; 1260 skb->dev = dev; 1261 can_skb_set_owner(skb, sk); 1262 err = can_send(skb, 1); /* send with loopback */ 1263 dev_put(dev); 1264 1265 if (err) 1266 return err; 1267 1268 return cfsiz + MHSIZ; 1269 } 1270 1271 /* 1272 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1273 */ 1274 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1275 { 1276 struct sock *sk = sock->sk; 1277 struct bcm_sock *bo = bcm_sk(sk); 1278 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1279 struct bcm_msg_head msg_head; 1280 int cfsiz; 1281 int ret; /* read bytes or error codes as return value */ 1282 1283 if (!bo->bound) 1284 return -ENOTCONN; 1285 1286 /* check for valid message length from userspace */ 1287 if (size < MHSIZ) 1288 return -EINVAL; 1289 1290 /* read message head information */ 1291 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1292 if (ret < 0) 1293 return ret; 1294 1295 cfsiz = CFSIZ(msg_head.flags); 1296 if ((size - MHSIZ) % cfsiz) 1297 return -EINVAL; 1298 1299 /* check for alternative ifindex for this bcm_op */ 1300 1301 if (!ifindex && msg->msg_name) { 1302 /* no bound device as default => check msg_name */ 1303 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1304 1305 if (msg->msg_namelen < BCM_MIN_NAMELEN) 1306 return -EINVAL; 1307 1308 if (addr->can_family != AF_CAN) 1309 return -EINVAL; 1310 1311 /* ifindex from sendto() */ 1312 ifindex = addr->can_ifindex; 1313 1314 if (ifindex) { 1315 struct net_device *dev; 1316 1317 dev = dev_get_by_index(sock_net(sk), ifindex); 1318 if (!dev) 1319 return -ENODEV; 1320 1321 if (dev->type != ARPHRD_CAN) { 1322 dev_put(dev); 1323 return -ENODEV; 1324 } 1325 1326 dev_put(dev); 1327 } 1328 } 1329 1330 lock_sock(sk); 1331 1332 switch (msg_head.opcode) { 1333 1334 case TX_SETUP: 1335 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1336 break; 1337 1338 case RX_SETUP: 1339 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1340 break; 1341 1342 case TX_DELETE: 1343 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1344 ret = MHSIZ; 1345 else 1346 ret = -EINVAL; 1347 break; 1348 1349 case RX_DELETE: 1350 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1351 ret = MHSIZ; 1352 else 1353 ret = -EINVAL; 1354 break; 1355 1356 case TX_READ: 1357 /* reuse msg_head for the reply to TX_READ */ 1358 msg_head.opcode = TX_STATUS; 1359 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1360 break; 1361 1362 case RX_READ: 1363 /* reuse msg_head for the reply to RX_READ */ 1364 msg_head.opcode = RX_STATUS; 1365 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1366 break; 1367 1368 case TX_SEND: 1369 /* we need exactly one CAN frame behind the msg head */ 1370 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1371 ret = -EINVAL; 1372 else 1373 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1374 break; 1375 1376 default: 1377 ret = -EINVAL; 1378 break; 1379 } 1380 1381 release_sock(sk); 1382 1383 return ret; 1384 } 1385 1386 /* 1387 * notification handler for netdevice status changes 1388 */ 1389 static void bcm_notify(struct bcm_sock *bo, unsigned long msg, 1390 struct net_device *dev) 1391 { 1392 struct sock *sk = &bo->sk; 1393 struct bcm_op *op; 1394 int notify_enodev = 0; 1395 1396 if (!net_eq(dev_net(dev), sock_net(sk))) 1397 return; 1398 1399 switch (msg) { 1400 1401 case NETDEV_UNREGISTER: 1402 lock_sock(sk); 1403 1404 /* remove device specific receive entries */ 1405 list_for_each_entry(op, &bo->rx_ops, list) 1406 if (op->rx_reg_dev == dev) 1407 bcm_rx_unreg(dev, op); 1408 1409 /* remove device reference, if this is our bound device */ 1410 if (bo->bound && bo->ifindex == dev->ifindex) { 1411 bo->bound = 0; 1412 bo->ifindex = 0; 1413 notify_enodev = 1; 1414 } 1415 1416 release_sock(sk); 1417 1418 if (notify_enodev) { 1419 sk->sk_err = ENODEV; 1420 if (!sock_flag(sk, SOCK_DEAD)) 1421 sk_error_report(sk); 1422 } 1423 break; 1424 1425 case NETDEV_DOWN: 1426 if (bo->bound && bo->ifindex == dev->ifindex) { 1427 sk->sk_err = ENETDOWN; 1428 if (!sock_flag(sk, SOCK_DEAD)) 1429 sk_error_report(sk); 1430 } 1431 } 1432 } 1433 1434 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1435 void *ptr) 1436 { 1437 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1438 1439 if (dev->type != ARPHRD_CAN) 1440 return NOTIFY_DONE; 1441 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 1442 return NOTIFY_DONE; 1443 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */ 1444 return NOTIFY_DONE; 1445 1446 spin_lock(&bcm_notifier_lock); 1447 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) { 1448 spin_unlock(&bcm_notifier_lock); 1449 bcm_notify(bcm_busy_notifier, msg, dev); 1450 spin_lock(&bcm_notifier_lock); 1451 } 1452 bcm_busy_notifier = NULL; 1453 spin_unlock(&bcm_notifier_lock); 1454 return NOTIFY_DONE; 1455 } 1456 1457 /* 1458 * initial settings for all BCM sockets to be set at socket creation time 1459 */ 1460 static int bcm_init(struct sock *sk) 1461 { 1462 struct bcm_sock *bo = bcm_sk(sk); 1463 1464 bo->bound = 0; 1465 bo->ifindex = 0; 1466 bo->dropped_usr_msgs = 0; 1467 bo->bcm_proc_read = NULL; 1468 1469 INIT_LIST_HEAD(&bo->tx_ops); 1470 INIT_LIST_HEAD(&bo->rx_ops); 1471 1472 /* set notifier */ 1473 spin_lock(&bcm_notifier_lock); 1474 list_add_tail(&bo->notifier, &bcm_notifier_list); 1475 spin_unlock(&bcm_notifier_lock); 1476 1477 return 0; 1478 } 1479 1480 /* 1481 * standard socket functions 1482 */ 1483 static int bcm_release(struct socket *sock) 1484 { 1485 struct sock *sk = sock->sk; 1486 struct net *net; 1487 struct bcm_sock *bo; 1488 struct bcm_op *op, *next; 1489 1490 if (!sk) 1491 return 0; 1492 1493 net = sock_net(sk); 1494 bo = bcm_sk(sk); 1495 1496 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1497 1498 spin_lock(&bcm_notifier_lock); 1499 while (bcm_busy_notifier == bo) { 1500 spin_unlock(&bcm_notifier_lock); 1501 schedule_timeout_uninterruptible(1); 1502 spin_lock(&bcm_notifier_lock); 1503 } 1504 list_del(&bo->notifier); 1505 spin_unlock(&bcm_notifier_lock); 1506 1507 lock_sock(sk); 1508 1509 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1510 bcm_remove_op(op); 1511 1512 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1513 /* 1514 * Don't care if we're bound or not (due to netdev problems) 1515 * can_rx_unregister() is always a save thing to do here. 1516 */ 1517 if (op->ifindex) { 1518 /* 1519 * Only remove subscriptions that had not 1520 * been removed due to NETDEV_UNREGISTER 1521 * in bcm_notifier() 1522 */ 1523 if (op->rx_reg_dev) { 1524 struct net_device *dev; 1525 1526 dev = dev_get_by_index(net, op->ifindex); 1527 if (dev) { 1528 bcm_rx_unreg(dev, op); 1529 dev_put(dev); 1530 } 1531 } 1532 } else 1533 can_rx_unregister(net, NULL, op->can_id, 1534 REGMASK(op->can_id), 1535 bcm_rx_handler, op); 1536 1537 } 1538 1539 synchronize_rcu(); 1540 1541 list_for_each_entry_safe(op, next, &bo->rx_ops, list) 1542 bcm_remove_op(op); 1543 1544 #if IS_ENABLED(CONFIG_PROC_FS) 1545 /* remove procfs entry */ 1546 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1547 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1548 #endif /* CONFIG_PROC_FS */ 1549 1550 /* remove device reference */ 1551 if (bo->bound) { 1552 bo->bound = 0; 1553 bo->ifindex = 0; 1554 } 1555 1556 sock_orphan(sk); 1557 sock->sk = NULL; 1558 1559 release_sock(sk); 1560 sock_put(sk); 1561 1562 return 0; 1563 } 1564 1565 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1566 int flags) 1567 { 1568 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1569 struct sock *sk = sock->sk; 1570 struct bcm_sock *bo = bcm_sk(sk); 1571 struct net *net = sock_net(sk); 1572 int ret = 0; 1573 1574 if (len < BCM_MIN_NAMELEN) 1575 return -EINVAL; 1576 1577 lock_sock(sk); 1578 1579 if (bo->bound) { 1580 ret = -EISCONN; 1581 goto fail; 1582 } 1583 1584 /* bind a device to this socket */ 1585 if (addr->can_ifindex) { 1586 struct net_device *dev; 1587 1588 dev = dev_get_by_index(net, addr->can_ifindex); 1589 if (!dev) { 1590 ret = -ENODEV; 1591 goto fail; 1592 } 1593 if (dev->type != ARPHRD_CAN) { 1594 dev_put(dev); 1595 ret = -ENODEV; 1596 goto fail; 1597 } 1598 1599 bo->ifindex = dev->ifindex; 1600 dev_put(dev); 1601 1602 } else { 1603 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1604 bo->ifindex = 0; 1605 } 1606 1607 #if IS_ENABLED(CONFIG_PROC_FS) 1608 if (net->can.bcmproc_dir) { 1609 /* unique socket address as filename */ 1610 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1611 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1612 net->can.bcmproc_dir, 1613 bcm_proc_show, sk); 1614 if (!bo->bcm_proc_read) { 1615 ret = -ENOMEM; 1616 goto fail; 1617 } 1618 } 1619 #endif /* CONFIG_PROC_FS */ 1620 1621 bo->bound = 1; 1622 1623 fail: 1624 release_sock(sk); 1625 1626 return ret; 1627 } 1628 1629 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1630 int flags) 1631 { 1632 struct sock *sk = sock->sk; 1633 struct sk_buff *skb; 1634 int error = 0; 1635 int err; 1636 1637 skb = skb_recv_datagram(sk, flags, &error); 1638 if (!skb) 1639 return error; 1640 1641 if (skb->len < size) 1642 size = skb->len; 1643 1644 err = memcpy_to_msg(msg, skb->data, size); 1645 if (err < 0) { 1646 skb_free_datagram(sk, skb); 1647 return err; 1648 } 1649 1650 sock_recv_cmsgs(msg, sk, skb); 1651 1652 if (msg->msg_name) { 1653 __sockaddr_check_size(BCM_MIN_NAMELEN); 1654 msg->msg_namelen = BCM_MIN_NAMELEN; 1655 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1656 } 1657 1658 skb_free_datagram(sk, skb); 1659 1660 return size; 1661 } 1662 1663 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1664 unsigned long arg) 1665 { 1666 /* no ioctls for socket layer -> hand it down to NIC layer */ 1667 return -ENOIOCTLCMD; 1668 } 1669 1670 static const struct proto_ops bcm_ops = { 1671 .family = PF_CAN, 1672 .release = bcm_release, 1673 .bind = sock_no_bind, 1674 .connect = bcm_connect, 1675 .socketpair = sock_no_socketpair, 1676 .accept = sock_no_accept, 1677 .getname = sock_no_getname, 1678 .poll = datagram_poll, 1679 .ioctl = bcm_sock_no_ioctlcmd, 1680 .gettstamp = sock_gettstamp, 1681 .listen = sock_no_listen, 1682 .shutdown = sock_no_shutdown, 1683 .sendmsg = bcm_sendmsg, 1684 .recvmsg = bcm_recvmsg, 1685 .mmap = sock_no_mmap, 1686 .sendpage = sock_no_sendpage, 1687 }; 1688 1689 static struct proto bcm_proto __read_mostly = { 1690 .name = "CAN_BCM", 1691 .owner = THIS_MODULE, 1692 .obj_size = sizeof(struct bcm_sock), 1693 .init = bcm_init, 1694 }; 1695 1696 static const struct can_proto bcm_can_proto = { 1697 .type = SOCK_DGRAM, 1698 .protocol = CAN_BCM, 1699 .ops = &bcm_ops, 1700 .prot = &bcm_proto, 1701 }; 1702 1703 static int canbcm_pernet_init(struct net *net) 1704 { 1705 #if IS_ENABLED(CONFIG_PROC_FS) 1706 /* create /proc/net/can-bcm directory */ 1707 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1708 #endif /* CONFIG_PROC_FS */ 1709 1710 return 0; 1711 } 1712 1713 static void canbcm_pernet_exit(struct net *net) 1714 { 1715 #if IS_ENABLED(CONFIG_PROC_FS) 1716 /* remove /proc/net/can-bcm directory */ 1717 if (net->can.bcmproc_dir) 1718 remove_proc_entry("can-bcm", net->proc_net); 1719 #endif /* CONFIG_PROC_FS */ 1720 } 1721 1722 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1723 .init = canbcm_pernet_init, 1724 .exit = canbcm_pernet_exit, 1725 }; 1726 1727 static struct notifier_block canbcm_notifier = { 1728 .notifier_call = bcm_notifier 1729 }; 1730 1731 static int __init bcm_module_init(void) 1732 { 1733 int err; 1734 1735 pr_info("can: broadcast manager protocol\n"); 1736 1737 err = can_proto_register(&bcm_can_proto); 1738 if (err < 0) { 1739 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1740 return err; 1741 } 1742 1743 register_pernet_subsys(&canbcm_pernet_ops); 1744 register_netdevice_notifier(&canbcm_notifier); 1745 return 0; 1746 } 1747 1748 static void __exit bcm_module_exit(void) 1749 { 1750 can_proto_unregister(&bcm_can_proto); 1751 unregister_netdevice_notifier(&canbcm_notifier); 1752 unregister_pernet_subsys(&canbcm_pernet_ops); 1753 } 1754 1755 module_init(bcm_module_init); 1756 module_exit(bcm_module_exit); 1757