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 struct rcu_head rcu; 104 int ifindex; 105 canid_t can_id; 106 u32 flags; 107 unsigned long frames_abs, frames_filtered; 108 struct bcm_timeval ival1, ival2; 109 struct hrtimer timer, thrtimer; 110 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 111 int rx_ifindex; 112 int cfsiz; 113 u32 count; 114 u32 nframes; 115 u32 currframe; 116 /* void pointers to arrays of struct can[fd]_frame */ 117 void *frames; 118 void *last_frames; 119 struct canfd_frame sframe; 120 struct canfd_frame last_sframe; 121 struct sock *sk; 122 struct net_device *rx_reg_dev; 123 }; 124 125 struct bcm_sock { 126 struct sock sk; 127 int bound; 128 int ifindex; 129 struct list_head notifier; 130 struct list_head rx_ops; 131 struct list_head tx_ops; 132 unsigned long dropped_usr_msgs; 133 struct proc_dir_entry *bcm_proc_read; 134 char procname [32]; /* inode number in decimal with \0 */ 135 }; 136 137 static LIST_HEAD(bcm_notifier_list); 138 static DEFINE_SPINLOCK(bcm_notifier_lock); 139 static struct bcm_sock *bcm_busy_notifier; 140 141 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 142 { 143 return (struct bcm_sock *)sk; 144 } 145 146 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 147 { 148 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 149 } 150 151 /* check limitations for timeval provided by user */ 152 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 153 { 154 if ((msg_head->ival1.tv_sec < 0) || 155 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 156 (msg_head->ival1.tv_usec < 0) || 157 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 158 (msg_head->ival2.tv_sec < 0) || 159 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 160 (msg_head->ival2.tv_usec < 0) || 161 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 162 return true; 163 164 return false; 165 } 166 167 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 168 #define OPSIZ sizeof(struct bcm_op) 169 #define MHSIZ sizeof(struct bcm_msg_head) 170 171 /* 172 * procfs functions 173 */ 174 #if IS_ENABLED(CONFIG_PROC_FS) 175 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 176 { 177 struct net_device *dev; 178 179 if (!ifindex) 180 return "any"; 181 182 rcu_read_lock(); 183 dev = dev_get_by_index_rcu(net, ifindex); 184 if (dev) 185 strcpy(result, dev->name); 186 else 187 strcpy(result, "???"); 188 rcu_read_unlock(); 189 190 return result; 191 } 192 193 static int bcm_proc_show(struct seq_file *m, void *v) 194 { 195 char ifname[IFNAMSIZ]; 196 struct net *net = m->private; 197 struct sock *sk = (struct sock *)pde_data(m->file->f_inode); 198 struct bcm_sock *bo = bcm_sk(sk); 199 struct bcm_op *op; 200 201 seq_printf(m, ">>> socket %pK", sk->sk_socket); 202 seq_printf(m, " / sk %pK", sk); 203 seq_printf(m, " / bo %pK", bo); 204 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 205 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 206 seq_printf(m, " <<<\n"); 207 208 list_for_each_entry(op, &bo->rx_ops, list) { 209 210 unsigned long reduction; 211 212 /* print only active entries & prevent division by zero */ 213 if (!op->frames_abs) 214 continue; 215 216 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 217 bcm_proc_getifname(net, ifname, op->ifindex)); 218 219 if (op->flags & CAN_FD_FRAME) 220 seq_printf(m, "(%u)", op->nframes); 221 else 222 seq_printf(m, "[%u]", op->nframes); 223 224 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 225 226 if (op->kt_ival1) 227 seq_printf(m, "timeo=%lld ", 228 (long long)ktime_to_us(op->kt_ival1)); 229 230 if (op->kt_ival2) 231 seq_printf(m, "thr=%lld ", 232 (long long)ktime_to_us(op->kt_ival2)); 233 234 seq_printf(m, "# recv %ld (%ld) => reduction: ", 235 op->frames_filtered, op->frames_abs); 236 237 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 238 239 seq_printf(m, "%s%ld%%\n", 240 (reduction == 100) ? "near " : "", reduction); 241 } 242 243 list_for_each_entry(op, &bo->tx_ops, list) { 244 245 seq_printf(m, "tx_op: %03X %s ", op->can_id, 246 bcm_proc_getifname(net, ifname, op->ifindex)); 247 248 if (op->flags & CAN_FD_FRAME) 249 seq_printf(m, "(%u) ", op->nframes); 250 else 251 seq_printf(m, "[%u] ", op->nframes); 252 253 if (op->kt_ival1) 254 seq_printf(m, "t1=%lld ", 255 (long long)ktime_to_us(op->kt_ival1)); 256 257 if (op->kt_ival2) 258 seq_printf(m, "t2=%lld ", 259 (long long)ktime_to_us(op->kt_ival2)); 260 261 seq_printf(m, "# sent %ld\n", op->frames_abs); 262 } 263 seq_putc(m, '\n'); 264 return 0; 265 } 266 #endif /* CONFIG_PROC_FS */ 267 268 /* 269 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 270 * of the given bcm tx op 271 */ 272 static void bcm_can_tx(struct bcm_op *op) 273 { 274 struct sk_buff *skb; 275 struct net_device *dev; 276 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 277 278 /* no target device? => exit */ 279 if (!op->ifindex) 280 return; 281 282 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 283 if (!dev) { 284 /* RFC: should this bcm_op remove itself here? */ 285 return; 286 } 287 288 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 289 if (!skb) 290 goto out; 291 292 can_skb_reserve(skb); 293 can_skb_prv(skb)->ifindex = dev->ifindex; 294 can_skb_prv(skb)->skbcnt = 0; 295 296 skb_put_data(skb, cf, op->cfsiz); 297 298 /* send with loopback */ 299 skb->dev = dev; 300 can_skb_set_owner(skb, op->sk); 301 can_send(skb, 1); 302 303 /* update statistics */ 304 op->currframe++; 305 op->frames_abs++; 306 307 /* reached last frame? */ 308 if (op->currframe >= op->nframes) 309 op->currframe = 0; 310 out: 311 dev_put(dev); 312 } 313 314 /* 315 * bcm_send_to_user - send a BCM message to the userspace 316 * (consisting of bcm_msg_head + x CAN frames) 317 */ 318 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 319 struct canfd_frame *frames, int has_timestamp) 320 { 321 struct sk_buff *skb; 322 struct canfd_frame *firstframe; 323 struct sockaddr_can *addr; 324 struct sock *sk = op->sk; 325 unsigned int datalen = head->nframes * op->cfsiz; 326 int err; 327 328 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 329 if (!skb) 330 return; 331 332 skb_put_data(skb, head, sizeof(*head)); 333 334 if (head->nframes) { 335 /* CAN frames starting here */ 336 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 337 338 skb_put_data(skb, frames, datalen); 339 340 /* 341 * the BCM uses the flags-element of the canfd_frame 342 * structure for internal purposes. This is only 343 * relevant for updates that are generated by the 344 * BCM, where nframes is 1 345 */ 346 if (head->nframes == 1) 347 firstframe->flags &= BCM_CAN_FLAGS_MASK; 348 } 349 350 if (has_timestamp) { 351 /* restore rx timestamp */ 352 skb->tstamp = op->rx_stamp; 353 } 354 355 /* 356 * Put the datagram to the queue so that bcm_recvmsg() can 357 * get it from there. We need to pass the interface index to 358 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 359 * containing the interface index. 360 */ 361 362 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 363 addr = (struct sockaddr_can *)skb->cb; 364 memset(addr, 0, sizeof(*addr)); 365 addr->can_family = AF_CAN; 366 addr->can_ifindex = op->rx_ifindex; 367 368 err = sock_queue_rcv_skb(sk, skb); 369 if (err < 0) { 370 struct bcm_sock *bo = bcm_sk(sk); 371 372 kfree_skb(skb); 373 /* don't care about overflows in this statistic */ 374 bo->dropped_usr_msgs++; 375 } 376 } 377 378 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt) 379 { 380 ktime_t ival; 381 382 if (op->kt_ival1 && op->count) 383 ival = op->kt_ival1; 384 else if (op->kt_ival2) 385 ival = op->kt_ival2; 386 else 387 return false; 388 389 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival)); 390 return true; 391 } 392 393 static void bcm_tx_start_timer(struct bcm_op *op) 394 { 395 if (bcm_tx_set_expiry(op, &op->timer)) 396 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT); 397 } 398 399 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */ 400 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 401 { 402 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 403 struct bcm_msg_head msg_head; 404 405 if (op->kt_ival1 && (op->count > 0)) { 406 op->count--; 407 if (!op->count && (op->flags & TX_COUNTEVT)) { 408 409 /* create notification to user */ 410 memset(&msg_head, 0, sizeof(msg_head)); 411 msg_head.opcode = TX_EXPIRED; 412 msg_head.flags = op->flags; 413 msg_head.count = op->count; 414 msg_head.ival1 = op->ival1; 415 msg_head.ival2 = op->ival2; 416 msg_head.can_id = op->can_id; 417 msg_head.nframes = 0; 418 419 bcm_send_to_user(op, &msg_head, NULL, 0); 420 } 421 bcm_can_tx(op); 422 423 } else if (op->kt_ival2) { 424 bcm_can_tx(op); 425 } 426 427 return bcm_tx_set_expiry(op, &op->timer) ? 428 HRTIMER_RESTART : HRTIMER_NORESTART; 429 } 430 431 /* 432 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 433 */ 434 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 435 { 436 struct bcm_msg_head head; 437 438 /* update statistics */ 439 op->frames_filtered++; 440 441 /* prevent statistics overflow */ 442 if (op->frames_filtered > ULONG_MAX/100) 443 op->frames_filtered = op->frames_abs = 0; 444 445 /* this element is not throttled anymore */ 446 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 447 448 memset(&head, 0, sizeof(head)); 449 head.opcode = RX_CHANGED; 450 head.flags = op->flags; 451 head.count = op->count; 452 head.ival1 = op->ival1; 453 head.ival2 = op->ival2; 454 head.can_id = op->can_id; 455 head.nframes = 1; 456 457 bcm_send_to_user(op, &head, data, 1); 458 } 459 460 /* 461 * bcm_rx_update_and_send - process a detected relevant receive content change 462 * 1. update the last received data 463 * 2. send a notification to the user (if possible) 464 */ 465 static void bcm_rx_update_and_send(struct bcm_op *op, 466 struct canfd_frame *lastdata, 467 const struct canfd_frame *rxdata) 468 { 469 memcpy(lastdata, rxdata, op->cfsiz); 470 471 /* mark as used and throttled by default */ 472 lastdata->flags |= (RX_RECV|RX_THR); 473 474 /* throttling mode inactive ? */ 475 if (!op->kt_ival2) { 476 /* send RX_CHANGED to the user immediately */ 477 bcm_rx_changed(op, lastdata); 478 return; 479 } 480 481 /* with active throttling timer we are just done here */ 482 if (hrtimer_active(&op->thrtimer)) 483 return; 484 485 /* first reception with enabled throttling mode */ 486 if (!op->kt_lastmsg) 487 goto rx_changed_settime; 488 489 /* got a second frame inside a potential throttle period? */ 490 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 491 ktime_to_us(op->kt_ival2)) { 492 /* do not send the saved data - only start throttle timer */ 493 hrtimer_start(&op->thrtimer, 494 ktime_add(op->kt_lastmsg, op->kt_ival2), 495 HRTIMER_MODE_ABS_SOFT); 496 return; 497 } 498 499 /* the gap was that big, that throttling was not needed here */ 500 rx_changed_settime: 501 bcm_rx_changed(op, lastdata); 502 op->kt_lastmsg = ktime_get(); 503 } 504 505 /* 506 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 507 * received data stored in op->last_frames[] 508 */ 509 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 510 const struct canfd_frame *rxdata) 511 { 512 struct canfd_frame *cf = op->frames + op->cfsiz * index; 513 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 514 int i; 515 516 /* 517 * no one uses the MSBs of flags for comparison, 518 * so we use it here to detect the first time of reception 519 */ 520 521 if (!(lcf->flags & RX_RECV)) { 522 /* received data for the first time => send update to user */ 523 bcm_rx_update_and_send(op, lcf, rxdata); 524 return; 525 } 526 527 /* do a real check in CAN frame data section */ 528 for (i = 0; i < rxdata->len; i += 8) { 529 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 530 (get_u64(cf, i) & get_u64(lcf, i))) { 531 bcm_rx_update_and_send(op, lcf, rxdata); 532 return; 533 } 534 } 535 536 if (op->flags & RX_CHECK_DLC) { 537 /* do a real check in CAN frame length */ 538 if (rxdata->len != lcf->len) { 539 bcm_rx_update_and_send(op, lcf, rxdata); 540 return; 541 } 542 } 543 } 544 545 /* 546 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 547 */ 548 static void bcm_rx_starttimer(struct bcm_op *op) 549 { 550 if (op->flags & RX_NO_AUTOTIMER) 551 return; 552 553 if (op->kt_ival1) 554 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT); 555 } 556 557 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */ 558 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 559 { 560 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 561 struct bcm_msg_head msg_head; 562 563 /* if user wants to be informed, when cyclic CAN-Messages come back */ 564 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 565 /* clear received CAN frames to indicate 'nothing received' */ 566 memset(op->last_frames, 0, op->nframes * op->cfsiz); 567 } 568 569 /* create notification to user */ 570 memset(&msg_head, 0, sizeof(msg_head)); 571 msg_head.opcode = RX_TIMEOUT; 572 msg_head.flags = op->flags; 573 msg_head.count = op->count; 574 msg_head.ival1 = op->ival1; 575 msg_head.ival2 = op->ival2; 576 msg_head.can_id = op->can_id; 577 msg_head.nframes = 0; 578 579 bcm_send_to_user(op, &msg_head, NULL, 0); 580 581 return HRTIMER_NORESTART; 582 } 583 584 /* 585 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 586 */ 587 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index) 588 { 589 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 590 591 if ((op->last_frames) && (lcf->flags & RX_THR)) { 592 bcm_rx_changed(op, lcf); 593 return 1; 594 } 595 return 0; 596 } 597 598 /* 599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 600 */ 601 static int bcm_rx_thr_flush(struct bcm_op *op) 602 { 603 int updated = 0; 604 605 if (op->nframes > 1) { 606 unsigned int i; 607 608 /* for MUX filter we start at index 1 */ 609 for (i = 1; i < op->nframes; i++) 610 updated += bcm_rx_do_flush(op, i); 611 612 } else { 613 /* for RX_FILTER_ID and simple filter */ 614 updated += bcm_rx_do_flush(op, 0); 615 } 616 617 return updated; 618 } 619 620 /* 621 * bcm_rx_thr_handler - the time for blocked content updates is over now: 622 * Check for throttled data and send it to the userspace 623 */ 624 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 625 { 626 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 627 628 if (bcm_rx_thr_flush(op)) { 629 hrtimer_forward_now(hrtimer, op->kt_ival2); 630 return HRTIMER_RESTART; 631 } else { 632 /* rearm throttle handling */ 633 op->kt_lastmsg = 0; 634 return HRTIMER_NORESTART; 635 } 636 } 637 638 /* 639 * bcm_rx_handler - handle a CAN frame reception 640 */ 641 static void bcm_rx_handler(struct sk_buff *skb, void *data) 642 { 643 struct bcm_op *op = (struct bcm_op *)data; 644 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 645 unsigned int i; 646 647 if (op->can_id != rxframe->can_id) 648 return; 649 650 /* make sure to handle the correct frame type (CAN / CAN FD) */ 651 if (skb->len != op->cfsiz) 652 return; 653 654 /* disable timeout */ 655 hrtimer_cancel(&op->timer); 656 657 /* save rx timestamp */ 658 op->rx_stamp = skb->tstamp; 659 /* save originator for recvfrom() */ 660 op->rx_ifindex = skb->dev->ifindex; 661 /* update statistics */ 662 op->frames_abs++; 663 664 if (op->flags & RX_RTR_FRAME) { 665 /* send reply for RTR-request (placed in op->frames[0]) */ 666 bcm_can_tx(op); 667 return; 668 } 669 670 if (op->flags & RX_FILTER_ID) { 671 /* the easiest case */ 672 bcm_rx_update_and_send(op, op->last_frames, rxframe); 673 goto rx_starttimer; 674 } 675 676 if (op->nframes == 1) { 677 /* simple compare with index 0 */ 678 bcm_rx_cmp_to_index(op, 0, rxframe); 679 goto rx_starttimer; 680 } 681 682 if (op->nframes > 1) { 683 /* 684 * multiplex compare 685 * 686 * find the first multiplex mask that fits. 687 * Remark: The MUX-mask is stored in index 0 - but only the 688 * first 64 bits of the frame data[] are relevant (CAN FD) 689 */ 690 691 for (i = 1; i < op->nframes; i++) { 692 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 693 (get_u64(op->frames, 0) & 694 get_u64(op->frames + op->cfsiz * i, 0))) { 695 bcm_rx_cmp_to_index(op, i, rxframe); 696 break; 697 } 698 } 699 } 700 701 rx_starttimer: 702 bcm_rx_starttimer(op); 703 } 704 705 /* 706 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 707 */ 708 static struct bcm_op *bcm_find_op(struct list_head *ops, 709 struct bcm_msg_head *mh, int ifindex) 710 { 711 struct bcm_op *op; 712 713 list_for_each_entry(op, ops, list) { 714 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 715 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 716 return op; 717 } 718 719 return NULL; 720 } 721 722 static void bcm_free_op_rcu(struct rcu_head *rcu_head) 723 { 724 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu); 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_remove_op(struct bcm_op *op) 736 { 737 hrtimer_cancel(&op->timer); 738 hrtimer_cancel(&op->thrtimer); 739 740 call_rcu(&op->rcu, bcm_free_op_rcu); 741 } 742 743 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 744 { 745 if (op->rx_reg_dev == dev) { 746 can_rx_unregister(dev_net(dev), dev, op->can_id, 747 REGMASK(op->can_id), bcm_rx_handler, op); 748 749 /* mark as removed subscription */ 750 op->rx_reg_dev = NULL; 751 } else 752 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 753 "mismatch %p %p\n", op->rx_reg_dev, dev); 754 } 755 756 /* 757 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 758 */ 759 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 760 int ifindex) 761 { 762 struct bcm_op *op, *n; 763 764 list_for_each_entry_safe(op, n, ops, list) { 765 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 766 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 767 768 /* disable automatic timer on frame reception */ 769 op->flags |= RX_NO_AUTOTIMER; 770 771 /* 772 * Don't care if we're bound or not (due to netdev 773 * problems) can_rx_unregister() is always a save 774 * thing to do here. 775 */ 776 if (op->ifindex) { 777 /* 778 * Only remove subscriptions that had not 779 * been removed due to NETDEV_UNREGISTER 780 * in bcm_notifier() 781 */ 782 if (op->rx_reg_dev) { 783 struct net_device *dev; 784 785 dev = dev_get_by_index(sock_net(op->sk), 786 op->ifindex); 787 if (dev) { 788 bcm_rx_unreg(dev, op); 789 dev_put(dev); 790 } 791 } 792 } else 793 can_rx_unregister(sock_net(op->sk), NULL, 794 op->can_id, 795 REGMASK(op->can_id), 796 bcm_rx_handler, op); 797 798 list_del(&op->list); 799 bcm_remove_op(op); 800 return 1; /* done */ 801 } 802 } 803 804 return 0; /* not found */ 805 } 806 807 /* 808 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 809 */ 810 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 811 int ifindex) 812 { 813 struct bcm_op *op, *n; 814 815 list_for_each_entry_safe(op, n, ops, list) { 816 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 817 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 818 list_del(&op->list); 819 bcm_remove_op(op); 820 return 1; /* done */ 821 } 822 } 823 824 return 0; /* not found */ 825 } 826 827 /* 828 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 829 */ 830 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 831 int ifindex) 832 { 833 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 834 835 if (!op) 836 return -EINVAL; 837 838 /* put current values into msg_head */ 839 msg_head->flags = op->flags; 840 msg_head->count = op->count; 841 msg_head->ival1 = op->ival1; 842 msg_head->ival2 = op->ival2; 843 msg_head->nframes = op->nframes; 844 845 bcm_send_to_user(op, msg_head, op->frames, 0); 846 847 return MHSIZ; 848 } 849 850 /* 851 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 852 */ 853 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 854 int ifindex, struct sock *sk) 855 { 856 struct bcm_sock *bo = bcm_sk(sk); 857 struct bcm_op *op; 858 struct canfd_frame *cf; 859 unsigned int i; 860 int err; 861 862 /* we need a real device to send frames */ 863 if (!ifindex) 864 return -ENODEV; 865 866 /* check nframes boundaries - we need at least one CAN frame */ 867 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 868 return -EINVAL; 869 870 /* check timeval limitations */ 871 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 872 return -EINVAL; 873 874 /* check the given can_id */ 875 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 876 if (op) { 877 /* update existing BCM operation */ 878 879 /* 880 * Do we need more space for the CAN frames than currently 881 * allocated? -> This is a _really_ unusual use-case and 882 * therefore (complexity / locking) it is not supported. 883 */ 884 if (msg_head->nframes > op->nframes) 885 return -E2BIG; 886 887 /* update CAN frames content */ 888 for (i = 0; i < msg_head->nframes; i++) { 889 890 cf = op->frames + op->cfsiz * i; 891 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 892 893 if (op->flags & CAN_FD_FRAME) { 894 if (cf->len > 64) 895 err = -EINVAL; 896 } else { 897 if (cf->len > 8) 898 err = -EINVAL; 899 } 900 901 if (err < 0) 902 return err; 903 904 if (msg_head->flags & TX_CP_CAN_ID) { 905 /* copy can_id into frame */ 906 cf->can_id = msg_head->can_id; 907 } 908 } 909 op->flags = msg_head->flags; 910 911 } else { 912 /* insert new BCM operation for the given can_id */ 913 914 op = kzalloc(OPSIZ, GFP_KERNEL); 915 if (!op) 916 return -ENOMEM; 917 918 op->can_id = msg_head->can_id; 919 op->cfsiz = CFSIZ(msg_head->flags); 920 op->flags = msg_head->flags; 921 922 /* create array for CAN frames and copy the data */ 923 if (msg_head->nframes > 1) { 924 op->frames = kmalloc_array(msg_head->nframes, 925 op->cfsiz, 926 GFP_KERNEL); 927 if (!op->frames) { 928 kfree(op); 929 return -ENOMEM; 930 } 931 } else 932 op->frames = &op->sframe; 933 934 for (i = 0; i < msg_head->nframes; i++) { 935 936 cf = op->frames + op->cfsiz * i; 937 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 938 939 if (op->flags & CAN_FD_FRAME) { 940 if (cf->len > 64) 941 err = -EINVAL; 942 } else { 943 if (cf->len > 8) 944 err = -EINVAL; 945 } 946 947 if (err < 0) { 948 if (op->frames != &op->sframe) 949 kfree(op->frames); 950 kfree(op); 951 return err; 952 } 953 954 if (msg_head->flags & TX_CP_CAN_ID) { 955 /* copy can_id into frame */ 956 cf->can_id = msg_head->can_id; 957 } 958 } 959 960 /* tx_ops never compare with previous received messages */ 961 op->last_frames = NULL; 962 963 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 964 op->sk = sk; 965 op->ifindex = ifindex; 966 967 /* initialize uninitialized (kzalloc) structure */ 968 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 969 HRTIMER_MODE_REL_SOFT); 970 op->timer.function = bcm_tx_timeout_handler; 971 972 /* currently unused in tx_ops */ 973 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 974 HRTIMER_MODE_REL_SOFT); 975 976 /* add this bcm_op to the list of the tx_ops */ 977 list_add(&op->list, &bo->tx_ops); 978 979 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 980 981 if (op->nframes != msg_head->nframes) { 982 op->nframes = msg_head->nframes; 983 /* start multiple frame transmission with index 0 */ 984 op->currframe = 0; 985 } 986 987 /* check flags */ 988 989 if (op->flags & TX_RESET_MULTI_IDX) { 990 /* start multiple frame transmission with index 0 */ 991 op->currframe = 0; 992 } 993 994 if (op->flags & SETTIMER) { 995 /* set timer values */ 996 op->count = msg_head->count; 997 op->ival1 = msg_head->ival1; 998 op->ival2 = msg_head->ival2; 999 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1000 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1001 1002 /* disable an active timer due to zero values? */ 1003 if (!op->kt_ival1 && !op->kt_ival2) 1004 hrtimer_cancel(&op->timer); 1005 } 1006 1007 if (op->flags & STARTTIMER) { 1008 hrtimer_cancel(&op->timer); 1009 /* spec: send CAN frame when starting timer */ 1010 op->flags |= TX_ANNOUNCE; 1011 } 1012 1013 if (op->flags & TX_ANNOUNCE) { 1014 bcm_can_tx(op); 1015 if (op->count) 1016 op->count--; 1017 } 1018 1019 if (op->flags & STARTTIMER) 1020 bcm_tx_start_timer(op); 1021 1022 return msg_head->nframes * op->cfsiz + MHSIZ; 1023 } 1024 1025 /* 1026 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1027 */ 1028 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1029 int ifindex, struct sock *sk) 1030 { 1031 struct bcm_sock *bo = bcm_sk(sk); 1032 struct bcm_op *op; 1033 int do_rx_register; 1034 int err = 0; 1035 1036 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1037 /* be robust against wrong usage ... */ 1038 msg_head->flags |= RX_FILTER_ID; 1039 /* ignore trailing garbage */ 1040 msg_head->nframes = 0; 1041 } 1042 1043 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1044 if (msg_head->nframes > MAX_NFRAMES + 1) 1045 return -EINVAL; 1046 1047 if ((msg_head->flags & RX_RTR_FRAME) && 1048 ((msg_head->nframes != 1) || 1049 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1050 return -EINVAL; 1051 1052 /* check timeval limitations */ 1053 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1054 return -EINVAL; 1055 1056 /* check the given can_id */ 1057 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1058 if (op) { 1059 /* update existing BCM operation */ 1060 1061 /* 1062 * Do we need more space for the CAN frames than currently 1063 * allocated? -> This is a _really_ unusual use-case and 1064 * therefore (complexity / locking) it is not supported. 1065 */ 1066 if (msg_head->nframes > op->nframes) 1067 return -E2BIG; 1068 1069 if (msg_head->nframes) { 1070 /* update CAN frames content */ 1071 err = memcpy_from_msg(op->frames, msg, 1072 msg_head->nframes * op->cfsiz); 1073 if (err < 0) 1074 return err; 1075 1076 /* clear last_frames to indicate 'nothing received' */ 1077 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1078 } 1079 1080 op->nframes = msg_head->nframes; 1081 op->flags = msg_head->flags; 1082 1083 /* Only an update -> do not call can_rx_register() */ 1084 do_rx_register = 0; 1085 1086 } else { 1087 /* insert new BCM operation for the given can_id */ 1088 op = kzalloc(OPSIZ, GFP_KERNEL); 1089 if (!op) 1090 return -ENOMEM; 1091 1092 op->can_id = msg_head->can_id; 1093 op->nframes = msg_head->nframes; 1094 op->cfsiz = CFSIZ(msg_head->flags); 1095 op->flags = msg_head->flags; 1096 1097 if (msg_head->nframes > 1) { 1098 /* create array for CAN frames and copy the data */ 1099 op->frames = kmalloc_array(msg_head->nframes, 1100 op->cfsiz, 1101 GFP_KERNEL); 1102 if (!op->frames) { 1103 kfree(op); 1104 return -ENOMEM; 1105 } 1106 1107 /* create and init array for received CAN frames */ 1108 op->last_frames = kcalloc(msg_head->nframes, 1109 op->cfsiz, 1110 GFP_KERNEL); 1111 if (!op->last_frames) { 1112 kfree(op->frames); 1113 kfree(op); 1114 return -ENOMEM; 1115 } 1116 1117 } else { 1118 op->frames = &op->sframe; 1119 op->last_frames = &op->last_sframe; 1120 } 1121 1122 if (msg_head->nframes) { 1123 err = memcpy_from_msg(op->frames, msg, 1124 msg_head->nframes * op->cfsiz); 1125 if (err < 0) { 1126 if (op->frames != &op->sframe) 1127 kfree(op->frames); 1128 if (op->last_frames != &op->last_sframe) 1129 kfree(op->last_frames); 1130 kfree(op); 1131 return err; 1132 } 1133 } 1134 1135 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1136 op->sk = sk; 1137 op->ifindex = ifindex; 1138 1139 /* ifindex for timeout events w/o previous frame reception */ 1140 op->rx_ifindex = ifindex; 1141 1142 /* initialize uninitialized (kzalloc) structure */ 1143 hrtimer_init(&op->timer, CLOCK_MONOTONIC, 1144 HRTIMER_MODE_REL_SOFT); 1145 op->timer.function = bcm_rx_timeout_handler; 1146 1147 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, 1148 HRTIMER_MODE_REL_SOFT); 1149 op->thrtimer.function = bcm_rx_thr_handler; 1150 1151 /* add this bcm_op to the list of the rx_ops */ 1152 list_add(&op->list, &bo->rx_ops); 1153 1154 /* call can_rx_register() */ 1155 do_rx_register = 1; 1156 1157 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1158 1159 /* check flags */ 1160 1161 if (op->flags & RX_RTR_FRAME) { 1162 struct canfd_frame *frame0 = op->frames; 1163 1164 /* no timers in RTR-mode */ 1165 hrtimer_cancel(&op->thrtimer); 1166 hrtimer_cancel(&op->timer); 1167 1168 /* 1169 * funny feature in RX(!)_SETUP only for RTR-mode: 1170 * copy can_id into frame BUT without RTR-flag to 1171 * prevent a full-load-loopback-test ... ;-] 1172 */ 1173 if ((op->flags & TX_CP_CAN_ID) || 1174 (frame0->can_id == op->can_id)) 1175 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1176 1177 } else { 1178 if (op->flags & SETTIMER) { 1179 1180 /* set timer value */ 1181 op->ival1 = msg_head->ival1; 1182 op->ival2 = msg_head->ival2; 1183 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1184 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1185 1186 /* disable an active timer due to zero value? */ 1187 if (!op->kt_ival1) 1188 hrtimer_cancel(&op->timer); 1189 1190 /* 1191 * In any case cancel the throttle timer, flush 1192 * potentially blocked msgs and reset throttle handling 1193 */ 1194 op->kt_lastmsg = 0; 1195 hrtimer_cancel(&op->thrtimer); 1196 bcm_rx_thr_flush(op); 1197 } 1198 1199 if ((op->flags & STARTTIMER) && op->kt_ival1) 1200 hrtimer_start(&op->timer, op->kt_ival1, 1201 HRTIMER_MODE_REL_SOFT); 1202 } 1203 1204 /* now we can register for can_ids, if we added a new bcm_op */ 1205 if (do_rx_register) { 1206 if (ifindex) { 1207 struct net_device *dev; 1208 1209 dev = dev_get_by_index(sock_net(sk), ifindex); 1210 if (dev) { 1211 err = can_rx_register(sock_net(sk), dev, 1212 op->can_id, 1213 REGMASK(op->can_id), 1214 bcm_rx_handler, op, 1215 "bcm", sk); 1216 1217 op->rx_reg_dev = dev; 1218 dev_put(dev); 1219 } 1220 1221 } else 1222 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1223 REGMASK(op->can_id), 1224 bcm_rx_handler, op, "bcm", sk); 1225 if (err) { 1226 /* this bcm rx op is broken -> remove it */ 1227 list_del(&op->list); 1228 bcm_remove_op(op); 1229 return err; 1230 } 1231 } 1232 1233 return msg_head->nframes * op->cfsiz + MHSIZ; 1234 } 1235 1236 /* 1237 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1238 */ 1239 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1240 int cfsiz) 1241 { 1242 struct sk_buff *skb; 1243 struct net_device *dev; 1244 int err; 1245 1246 /* we need a real device to send frames */ 1247 if (!ifindex) 1248 return -ENODEV; 1249 1250 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1251 if (!skb) 1252 return -ENOMEM; 1253 1254 can_skb_reserve(skb); 1255 1256 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1257 if (err < 0) { 1258 kfree_skb(skb); 1259 return err; 1260 } 1261 1262 dev = dev_get_by_index(sock_net(sk), ifindex); 1263 if (!dev) { 1264 kfree_skb(skb); 1265 return -ENODEV; 1266 } 1267 1268 can_skb_prv(skb)->ifindex = dev->ifindex; 1269 can_skb_prv(skb)->skbcnt = 0; 1270 skb->dev = dev; 1271 can_skb_set_owner(skb, sk); 1272 err = can_send(skb, 1); /* send with loopback */ 1273 dev_put(dev); 1274 1275 if (err) 1276 return err; 1277 1278 return cfsiz + MHSIZ; 1279 } 1280 1281 /* 1282 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1283 */ 1284 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1285 { 1286 struct sock *sk = sock->sk; 1287 struct bcm_sock *bo = bcm_sk(sk); 1288 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1289 struct bcm_msg_head msg_head; 1290 int cfsiz; 1291 int ret; /* read bytes or error codes as return value */ 1292 1293 if (!bo->bound) 1294 return -ENOTCONN; 1295 1296 /* check for valid message length from userspace */ 1297 if (size < MHSIZ) 1298 return -EINVAL; 1299 1300 /* read message head information */ 1301 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1302 if (ret < 0) 1303 return ret; 1304 1305 cfsiz = CFSIZ(msg_head.flags); 1306 if ((size - MHSIZ) % cfsiz) 1307 return -EINVAL; 1308 1309 /* check for alternative ifindex for this bcm_op */ 1310 1311 if (!ifindex && msg->msg_name) { 1312 /* no bound device as default => check msg_name */ 1313 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1314 1315 if (msg->msg_namelen < BCM_MIN_NAMELEN) 1316 return -EINVAL; 1317 1318 if (addr->can_family != AF_CAN) 1319 return -EINVAL; 1320 1321 /* ifindex from sendto() */ 1322 ifindex = addr->can_ifindex; 1323 1324 if (ifindex) { 1325 struct net_device *dev; 1326 1327 dev = dev_get_by_index(sock_net(sk), ifindex); 1328 if (!dev) 1329 return -ENODEV; 1330 1331 if (dev->type != ARPHRD_CAN) { 1332 dev_put(dev); 1333 return -ENODEV; 1334 } 1335 1336 dev_put(dev); 1337 } 1338 } 1339 1340 lock_sock(sk); 1341 1342 switch (msg_head.opcode) { 1343 1344 case TX_SETUP: 1345 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1346 break; 1347 1348 case RX_SETUP: 1349 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1350 break; 1351 1352 case TX_DELETE: 1353 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1354 ret = MHSIZ; 1355 else 1356 ret = -EINVAL; 1357 break; 1358 1359 case RX_DELETE: 1360 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1361 ret = MHSIZ; 1362 else 1363 ret = -EINVAL; 1364 break; 1365 1366 case TX_READ: 1367 /* reuse msg_head for the reply to TX_READ */ 1368 msg_head.opcode = TX_STATUS; 1369 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1370 break; 1371 1372 case RX_READ: 1373 /* reuse msg_head for the reply to RX_READ */ 1374 msg_head.opcode = RX_STATUS; 1375 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1376 break; 1377 1378 case TX_SEND: 1379 /* we need exactly one CAN frame behind the msg head */ 1380 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1381 ret = -EINVAL; 1382 else 1383 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1384 break; 1385 1386 default: 1387 ret = -EINVAL; 1388 break; 1389 } 1390 1391 release_sock(sk); 1392 1393 return ret; 1394 } 1395 1396 /* 1397 * notification handler for netdevice status changes 1398 */ 1399 static void bcm_notify(struct bcm_sock *bo, unsigned long msg, 1400 struct net_device *dev) 1401 { 1402 struct sock *sk = &bo->sk; 1403 struct bcm_op *op; 1404 int notify_enodev = 0; 1405 1406 if (!net_eq(dev_net(dev), sock_net(sk))) 1407 return; 1408 1409 switch (msg) { 1410 1411 case NETDEV_UNREGISTER: 1412 lock_sock(sk); 1413 1414 /* remove device specific receive entries */ 1415 list_for_each_entry(op, &bo->rx_ops, list) 1416 if (op->rx_reg_dev == dev) 1417 bcm_rx_unreg(dev, op); 1418 1419 /* remove device reference, if this is our bound device */ 1420 if (bo->bound && bo->ifindex == dev->ifindex) { 1421 bo->bound = 0; 1422 bo->ifindex = 0; 1423 notify_enodev = 1; 1424 } 1425 1426 release_sock(sk); 1427 1428 if (notify_enodev) { 1429 sk->sk_err = ENODEV; 1430 if (!sock_flag(sk, SOCK_DEAD)) 1431 sk_error_report(sk); 1432 } 1433 break; 1434 1435 case NETDEV_DOWN: 1436 if (bo->bound && bo->ifindex == dev->ifindex) { 1437 sk->sk_err = ENETDOWN; 1438 if (!sock_flag(sk, SOCK_DEAD)) 1439 sk_error_report(sk); 1440 } 1441 } 1442 } 1443 1444 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1445 void *ptr) 1446 { 1447 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1448 1449 if (dev->type != ARPHRD_CAN) 1450 return NOTIFY_DONE; 1451 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 1452 return NOTIFY_DONE; 1453 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */ 1454 return NOTIFY_DONE; 1455 1456 spin_lock(&bcm_notifier_lock); 1457 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) { 1458 spin_unlock(&bcm_notifier_lock); 1459 bcm_notify(bcm_busy_notifier, msg, dev); 1460 spin_lock(&bcm_notifier_lock); 1461 } 1462 bcm_busy_notifier = NULL; 1463 spin_unlock(&bcm_notifier_lock); 1464 return NOTIFY_DONE; 1465 } 1466 1467 /* 1468 * initial settings for all BCM sockets to be set at socket creation time 1469 */ 1470 static int bcm_init(struct sock *sk) 1471 { 1472 struct bcm_sock *bo = bcm_sk(sk); 1473 1474 bo->bound = 0; 1475 bo->ifindex = 0; 1476 bo->dropped_usr_msgs = 0; 1477 bo->bcm_proc_read = NULL; 1478 1479 INIT_LIST_HEAD(&bo->tx_ops); 1480 INIT_LIST_HEAD(&bo->rx_ops); 1481 1482 /* set notifier */ 1483 spin_lock(&bcm_notifier_lock); 1484 list_add_tail(&bo->notifier, &bcm_notifier_list); 1485 spin_unlock(&bcm_notifier_lock); 1486 1487 return 0; 1488 } 1489 1490 /* 1491 * standard socket functions 1492 */ 1493 static int bcm_release(struct socket *sock) 1494 { 1495 struct sock *sk = sock->sk; 1496 struct net *net; 1497 struct bcm_sock *bo; 1498 struct bcm_op *op, *next; 1499 1500 if (!sk) 1501 return 0; 1502 1503 net = sock_net(sk); 1504 bo = bcm_sk(sk); 1505 1506 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1507 1508 spin_lock(&bcm_notifier_lock); 1509 while (bcm_busy_notifier == bo) { 1510 spin_unlock(&bcm_notifier_lock); 1511 schedule_timeout_uninterruptible(1); 1512 spin_lock(&bcm_notifier_lock); 1513 } 1514 list_del(&bo->notifier); 1515 spin_unlock(&bcm_notifier_lock); 1516 1517 lock_sock(sk); 1518 1519 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1520 bcm_remove_op(op); 1521 1522 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1523 /* 1524 * Don't care if we're bound or not (due to netdev problems) 1525 * can_rx_unregister() is always a save thing to do here. 1526 */ 1527 if (op->ifindex) { 1528 /* 1529 * Only remove subscriptions that had not 1530 * been removed due to NETDEV_UNREGISTER 1531 * in bcm_notifier() 1532 */ 1533 if (op->rx_reg_dev) { 1534 struct net_device *dev; 1535 1536 dev = dev_get_by_index(net, op->ifindex); 1537 if (dev) { 1538 bcm_rx_unreg(dev, op); 1539 dev_put(dev); 1540 } 1541 } 1542 } else 1543 can_rx_unregister(net, NULL, op->can_id, 1544 REGMASK(op->can_id), 1545 bcm_rx_handler, op); 1546 1547 } 1548 1549 synchronize_rcu(); 1550 1551 list_for_each_entry_safe(op, next, &bo->rx_ops, list) 1552 bcm_remove_op(op); 1553 1554 #if IS_ENABLED(CONFIG_PROC_FS) 1555 /* remove procfs entry */ 1556 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1557 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1558 #endif /* CONFIG_PROC_FS */ 1559 1560 /* remove device reference */ 1561 if (bo->bound) { 1562 bo->bound = 0; 1563 bo->ifindex = 0; 1564 } 1565 1566 sock_orphan(sk); 1567 sock->sk = NULL; 1568 1569 release_sock(sk); 1570 sock_put(sk); 1571 1572 return 0; 1573 } 1574 1575 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1576 int flags) 1577 { 1578 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1579 struct sock *sk = sock->sk; 1580 struct bcm_sock *bo = bcm_sk(sk); 1581 struct net *net = sock_net(sk); 1582 int ret = 0; 1583 1584 if (len < BCM_MIN_NAMELEN) 1585 return -EINVAL; 1586 1587 lock_sock(sk); 1588 1589 if (bo->bound) { 1590 ret = -EISCONN; 1591 goto fail; 1592 } 1593 1594 /* bind a device to this socket */ 1595 if (addr->can_ifindex) { 1596 struct net_device *dev; 1597 1598 dev = dev_get_by_index(net, addr->can_ifindex); 1599 if (!dev) { 1600 ret = -ENODEV; 1601 goto fail; 1602 } 1603 if (dev->type != ARPHRD_CAN) { 1604 dev_put(dev); 1605 ret = -ENODEV; 1606 goto fail; 1607 } 1608 1609 bo->ifindex = dev->ifindex; 1610 dev_put(dev); 1611 1612 } else { 1613 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1614 bo->ifindex = 0; 1615 } 1616 1617 #if IS_ENABLED(CONFIG_PROC_FS) 1618 if (net->can.bcmproc_dir) { 1619 /* unique socket address as filename */ 1620 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1621 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1622 net->can.bcmproc_dir, 1623 bcm_proc_show, sk); 1624 if (!bo->bcm_proc_read) { 1625 ret = -ENOMEM; 1626 goto fail; 1627 } 1628 } 1629 #endif /* CONFIG_PROC_FS */ 1630 1631 bo->bound = 1; 1632 1633 fail: 1634 release_sock(sk); 1635 1636 return ret; 1637 } 1638 1639 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1640 int flags) 1641 { 1642 struct sock *sk = sock->sk; 1643 struct sk_buff *skb; 1644 int error = 0; 1645 int err; 1646 1647 skb = skb_recv_datagram(sk, flags, &error); 1648 if (!skb) 1649 return error; 1650 1651 if (skb->len < size) 1652 size = skb->len; 1653 1654 err = memcpy_to_msg(msg, skb->data, size); 1655 if (err < 0) { 1656 skb_free_datagram(sk, skb); 1657 return err; 1658 } 1659 1660 sock_recv_cmsgs(msg, sk, skb); 1661 1662 if (msg->msg_name) { 1663 __sockaddr_check_size(BCM_MIN_NAMELEN); 1664 msg->msg_namelen = BCM_MIN_NAMELEN; 1665 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1666 } 1667 1668 skb_free_datagram(sk, skb); 1669 1670 return size; 1671 } 1672 1673 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1674 unsigned long arg) 1675 { 1676 /* no ioctls for socket layer -> hand it down to NIC layer */ 1677 return -ENOIOCTLCMD; 1678 } 1679 1680 static const struct proto_ops bcm_ops = { 1681 .family = PF_CAN, 1682 .release = bcm_release, 1683 .bind = sock_no_bind, 1684 .connect = bcm_connect, 1685 .socketpair = sock_no_socketpair, 1686 .accept = sock_no_accept, 1687 .getname = sock_no_getname, 1688 .poll = datagram_poll, 1689 .ioctl = bcm_sock_no_ioctlcmd, 1690 .gettstamp = sock_gettstamp, 1691 .listen = sock_no_listen, 1692 .shutdown = sock_no_shutdown, 1693 .sendmsg = bcm_sendmsg, 1694 .recvmsg = bcm_recvmsg, 1695 .mmap = sock_no_mmap, 1696 .sendpage = sock_no_sendpage, 1697 }; 1698 1699 static struct proto bcm_proto __read_mostly = { 1700 .name = "CAN_BCM", 1701 .owner = THIS_MODULE, 1702 .obj_size = sizeof(struct bcm_sock), 1703 .init = bcm_init, 1704 }; 1705 1706 static const struct can_proto bcm_can_proto = { 1707 .type = SOCK_DGRAM, 1708 .protocol = CAN_BCM, 1709 .ops = &bcm_ops, 1710 .prot = &bcm_proto, 1711 }; 1712 1713 static int canbcm_pernet_init(struct net *net) 1714 { 1715 #if IS_ENABLED(CONFIG_PROC_FS) 1716 /* create /proc/net/can-bcm directory */ 1717 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1718 #endif /* CONFIG_PROC_FS */ 1719 1720 return 0; 1721 } 1722 1723 static void canbcm_pernet_exit(struct net *net) 1724 { 1725 #if IS_ENABLED(CONFIG_PROC_FS) 1726 /* remove /proc/net/can-bcm directory */ 1727 if (net->can.bcmproc_dir) 1728 remove_proc_entry("can-bcm", net->proc_net); 1729 #endif /* CONFIG_PROC_FS */ 1730 } 1731 1732 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1733 .init = canbcm_pernet_init, 1734 .exit = canbcm_pernet_exit, 1735 }; 1736 1737 static struct notifier_block canbcm_notifier = { 1738 .notifier_call = bcm_notifier 1739 }; 1740 1741 static int __init bcm_module_init(void) 1742 { 1743 int err; 1744 1745 pr_info("can: broadcast manager protocol\n"); 1746 1747 err = can_proto_register(&bcm_can_proto); 1748 if (err < 0) { 1749 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1750 return err; 1751 } 1752 1753 register_pernet_subsys(&canbcm_pernet_ops); 1754 register_netdevice_notifier(&canbcm_notifier); 1755 return 0; 1756 } 1757 1758 static void __exit bcm_module_exit(void) 1759 { 1760 can_proto_unregister(&bcm_can_proto); 1761 unregister_netdevice_notifier(&canbcm_notifier); 1762 unregister_pernet_subsys(&canbcm_pernet_ops); 1763 } 1764 1765 module_init(bcm_module_init); 1766 module_exit(bcm_module_exit); 1767