1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 2 /* 3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content 4 * 5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of Volkswagen nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * Alternatively, provided that this notice is retained in full, this 21 * software may be distributed under the terms of the GNU General 22 * Public License ("GPL") version 2, in which case the provisions of the 23 * GPL apply INSTEAD OF those given above. 24 * 25 * The provided data structures and external interfaces from this code 26 * are not restricted to be used by modules with a GPL compatible license. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 39 * DAMAGE. 40 * 41 */ 42 43 #include <linux/module.h> 44 #include <linux/init.h> 45 #include <linux/interrupt.h> 46 #include <linux/hrtimer.h> 47 #include <linux/list.h> 48 #include <linux/proc_fs.h> 49 #include <linux/seq_file.h> 50 #include <linux/uio.h> 51 #include <linux/net.h> 52 #include <linux/netdevice.h> 53 #include <linux/socket.h> 54 #include <linux/if_arp.h> 55 #include <linux/skbuff.h> 56 #include <linux/can.h> 57 #include <linux/can/core.h> 58 #include <linux/can/skb.h> 59 #include <linux/can/bcm.h> 60 #include <linux/slab.h> 61 #include <net/sock.h> 62 #include <net/net_namespace.h> 63 64 /* 65 * To send multiple CAN frame content within TX_SETUP or to filter 66 * CAN messages with multiplex index within RX_SETUP, the number of 67 * different filters is limited to 256 due to the one byte index value. 68 */ 69 #define MAX_NFRAMES 256 70 71 /* limit timers to 400 days for sending/timeouts */ 72 #define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60) 73 74 /* use of last_frames[index].flags */ 75 #define RX_RECV 0x40 /* received data for this element */ 76 #define RX_THR 0x80 /* element not been sent due to throttle feature */ 77 #define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */ 78 79 /* get best masking value for can_rx_register() for a given single can_id */ 80 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ 81 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ 82 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) 83 84 #define CAN_BCM_VERSION "20170425" 85 86 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 87 MODULE_LICENSE("Dual BSD/GPL"); 88 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 89 MODULE_ALIAS("can-proto-2"); 90 91 /* 92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is 93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured 94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler(). 95 */ 96 static inline u64 get_u64(const struct canfd_frame *cp, int offset) 97 { 98 return *(u64 *)(cp->data + offset); 99 } 100 101 struct bcm_op { 102 struct list_head list; 103 int ifindex; 104 canid_t can_id; 105 u32 flags; 106 unsigned long frames_abs, frames_filtered; 107 struct bcm_timeval ival1, ival2; 108 struct hrtimer timer, thrtimer; 109 struct tasklet_struct tsklet, thrtsklet; 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 notifier_block 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 inline struct bcm_sock *bcm_sk(const struct sock *sk) 138 { 139 return (struct bcm_sock *)sk; 140 } 141 142 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 143 { 144 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 145 } 146 147 /* check limitations for timeval provided by user */ 148 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 149 { 150 if ((msg_head->ival1.tv_sec < 0) || 151 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 152 (msg_head->ival1.tv_usec < 0) || 153 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 154 (msg_head->ival2.tv_sec < 0) || 155 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 156 (msg_head->ival2.tv_usec < 0) || 157 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 158 return true; 159 160 return false; 161 } 162 163 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 164 #define OPSIZ sizeof(struct bcm_op) 165 #define MHSIZ sizeof(struct bcm_msg_head) 166 167 /* 168 * procfs functions 169 */ 170 #if IS_ENABLED(CONFIG_PROC_FS) 171 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 172 { 173 struct net_device *dev; 174 175 if (!ifindex) 176 return "any"; 177 178 rcu_read_lock(); 179 dev = dev_get_by_index_rcu(net, ifindex); 180 if (dev) 181 strcpy(result, dev->name); 182 else 183 strcpy(result, "???"); 184 rcu_read_unlock(); 185 186 return result; 187 } 188 189 static int bcm_proc_show(struct seq_file *m, void *v) 190 { 191 char ifname[IFNAMSIZ]; 192 struct net *net = m->private; 193 struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode); 194 struct bcm_sock *bo = bcm_sk(sk); 195 struct bcm_op *op; 196 197 seq_printf(m, ">>> socket %pK", sk->sk_socket); 198 seq_printf(m, " / sk %pK", sk); 199 seq_printf(m, " / bo %pK", bo); 200 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 201 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 202 seq_printf(m, " <<<\n"); 203 204 list_for_each_entry(op, &bo->rx_ops, list) { 205 206 unsigned long reduction; 207 208 /* print only active entries & prevent division by zero */ 209 if (!op->frames_abs) 210 continue; 211 212 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 213 bcm_proc_getifname(net, ifname, op->ifindex)); 214 215 if (op->flags & CAN_FD_FRAME) 216 seq_printf(m, "(%u)", op->nframes); 217 else 218 seq_printf(m, "[%u]", op->nframes); 219 220 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 221 222 if (op->kt_ival1) 223 seq_printf(m, "timeo=%lld ", 224 (long long)ktime_to_us(op->kt_ival1)); 225 226 if (op->kt_ival2) 227 seq_printf(m, "thr=%lld ", 228 (long long)ktime_to_us(op->kt_ival2)); 229 230 seq_printf(m, "# recv %ld (%ld) => reduction: ", 231 op->frames_filtered, op->frames_abs); 232 233 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 234 235 seq_printf(m, "%s%ld%%\n", 236 (reduction == 100) ? "near " : "", reduction); 237 } 238 239 list_for_each_entry(op, &bo->tx_ops, list) { 240 241 seq_printf(m, "tx_op: %03X %s ", op->can_id, 242 bcm_proc_getifname(net, ifname, op->ifindex)); 243 244 if (op->flags & CAN_FD_FRAME) 245 seq_printf(m, "(%u) ", op->nframes); 246 else 247 seq_printf(m, "[%u] ", op->nframes); 248 249 if (op->kt_ival1) 250 seq_printf(m, "t1=%lld ", 251 (long long)ktime_to_us(op->kt_ival1)); 252 253 if (op->kt_ival2) 254 seq_printf(m, "t2=%lld ", 255 (long long)ktime_to_us(op->kt_ival2)); 256 257 seq_printf(m, "# sent %ld\n", op->frames_abs); 258 } 259 seq_putc(m, '\n'); 260 return 0; 261 } 262 #endif /* CONFIG_PROC_FS */ 263 264 /* 265 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 266 * of the given bcm tx op 267 */ 268 static void bcm_can_tx(struct bcm_op *op) 269 { 270 struct sk_buff *skb; 271 struct net_device *dev; 272 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe; 273 274 /* no target device? => exit */ 275 if (!op->ifindex) 276 return; 277 278 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 279 if (!dev) { 280 /* RFC: should this bcm_op remove itself here? */ 281 return; 282 } 283 284 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 285 if (!skb) 286 goto out; 287 288 can_skb_reserve(skb); 289 can_skb_prv(skb)->ifindex = dev->ifindex; 290 can_skb_prv(skb)->skbcnt = 0; 291 292 skb_put_data(skb, cf, op->cfsiz); 293 294 /* send with loopback */ 295 skb->dev = dev; 296 can_skb_set_owner(skb, op->sk); 297 can_send(skb, 1); 298 299 /* update statistics */ 300 op->currframe++; 301 op->frames_abs++; 302 303 /* reached last frame? */ 304 if (op->currframe >= op->nframes) 305 op->currframe = 0; 306 out: 307 dev_put(dev); 308 } 309 310 /* 311 * bcm_send_to_user - send a BCM message to the userspace 312 * (consisting of bcm_msg_head + x CAN frames) 313 */ 314 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 315 struct canfd_frame *frames, int has_timestamp) 316 { 317 struct sk_buff *skb; 318 struct canfd_frame *firstframe; 319 struct sockaddr_can *addr; 320 struct sock *sk = op->sk; 321 unsigned int datalen = head->nframes * op->cfsiz; 322 int err; 323 324 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 325 if (!skb) 326 return; 327 328 skb_put_data(skb, head, sizeof(*head)); 329 330 if (head->nframes) { 331 /* CAN frames starting here */ 332 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 333 334 skb_put_data(skb, frames, datalen); 335 336 /* 337 * the BCM uses the flags-element of the canfd_frame 338 * structure for internal purposes. This is only 339 * relevant for updates that are generated by the 340 * BCM, where nframes is 1 341 */ 342 if (head->nframes == 1) 343 firstframe->flags &= BCM_CAN_FLAGS_MASK; 344 } 345 346 if (has_timestamp) { 347 /* restore rx timestamp */ 348 skb->tstamp = op->rx_stamp; 349 } 350 351 /* 352 * Put the datagram to the queue so that bcm_recvmsg() can 353 * get it from there. We need to pass the interface index to 354 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 355 * containing the interface index. 356 */ 357 358 sock_skb_cb_check_size(sizeof(struct sockaddr_can)); 359 addr = (struct sockaddr_can *)skb->cb; 360 memset(addr, 0, sizeof(*addr)); 361 addr->can_family = AF_CAN; 362 addr->can_ifindex = op->rx_ifindex; 363 364 err = sock_queue_rcv_skb(sk, skb); 365 if (err < 0) { 366 struct bcm_sock *bo = bcm_sk(sk); 367 368 kfree_skb(skb); 369 /* don't care about overflows in this statistic */ 370 bo->dropped_usr_msgs++; 371 } 372 } 373 374 static void bcm_tx_start_timer(struct bcm_op *op) 375 { 376 if (op->kt_ival1 && op->count) 377 hrtimer_start(&op->timer, 378 ktime_add(ktime_get(), op->kt_ival1), 379 HRTIMER_MODE_ABS); 380 else if (op->kt_ival2) 381 hrtimer_start(&op->timer, 382 ktime_add(ktime_get(), op->kt_ival2), 383 HRTIMER_MODE_ABS); 384 } 385 386 static void bcm_tx_timeout_tsklet(unsigned long data) 387 { 388 struct bcm_op *op = (struct bcm_op *)data; 389 struct bcm_msg_head msg_head; 390 391 if (op->kt_ival1 && (op->count > 0)) { 392 393 op->count--; 394 if (!op->count && (op->flags & TX_COUNTEVT)) { 395 396 /* create notification to user */ 397 msg_head.opcode = TX_EXPIRED; 398 msg_head.flags = op->flags; 399 msg_head.count = op->count; 400 msg_head.ival1 = op->ival1; 401 msg_head.ival2 = op->ival2; 402 msg_head.can_id = op->can_id; 403 msg_head.nframes = 0; 404 405 bcm_send_to_user(op, &msg_head, NULL, 0); 406 } 407 bcm_can_tx(op); 408 409 } else if (op->kt_ival2) 410 bcm_can_tx(op); 411 412 bcm_tx_start_timer(op); 413 } 414 415 /* 416 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions 417 */ 418 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 419 { 420 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 421 422 tasklet_schedule(&op->tsklet); 423 424 return HRTIMER_NORESTART; 425 } 426 427 /* 428 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 429 */ 430 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 431 { 432 struct bcm_msg_head head; 433 434 /* update statistics */ 435 op->frames_filtered++; 436 437 /* prevent statistics overflow */ 438 if (op->frames_filtered > ULONG_MAX/100) 439 op->frames_filtered = op->frames_abs = 0; 440 441 /* this element is not throttled anymore */ 442 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); 443 444 head.opcode = RX_CHANGED; 445 head.flags = op->flags; 446 head.count = op->count; 447 head.ival1 = op->ival1; 448 head.ival2 = op->ival2; 449 head.can_id = op->can_id; 450 head.nframes = 1; 451 452 bcm_send_to_user(op, &head, data, 1); 453 } 454 455 /* 456 * bcm_rx_update_and_send - process a detected relevant receive content change 457 * 1. update the last received data 458 * 2. send a notification to the user (if possible) 459 */ 460 static void bcm_rx_update_and_send(struct bcm_op *op, 461 struct canfd_frame *lastdata, 462 const struct canfd_frame *rxdata) 463 { 464 memcpy(lastdata, rxdata, op->cfsiz); 465 466 /* mark as used and throttled by default */ 467 lastdata->flags |= (RX_RECV|RX_THR); 468 469 /* throttling mode inactive ? */ 470 if (!op->kt_ival2) { 471 /* send RX_CHANGED to the user immediately */ 472 bcm_rx_changed(op, lastdata); 473 return; 474 } 475 476 /* with active throttling timer we are just done here */ 477 if (hrtimer_active(&op->thrtimer)) 478 return; 479 480 /* first reception with enabled throttling mode */ 481 if (!op->kt_lastmsg) 482 goto rx_changed_settime; 483 484 /* got a second frame inside a potential throttle period? */ 485 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 486 ktime_to_us(op->kt_ival2)) { 487 /* do not send the saved data - only start throttle timer */ 488 hrtimer_start(&op->thrtimer, 489 ktime_add(op->kt_lastmsg, op->kt_ival2), 490 HRTIMER_MODE_ABS); 491 return; 492 } 493 494 /* the gap was that big, that throttling was not needed here */ 495 rx_changed_settime: 496 bcm_rx_changed(op, lastdata); 497 op->kt_lastmsg = ktime_get(); 498 } 499 500 /* 501 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 502 * received data stored in op->last_frames[] 503 */ 504 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 505 const struct canfd_frame *rxdata) 506 { 507 struct canfd_frame *cf = op->frames + op->cfsiz * index; 508 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 509 int i; 510 511 /* 512 * no one uses the MSBs of flags for comparison, 513 * so we use it here to detect the first time of reception 514 */ 515 516 if (!(lcf->flags & RX_RECV)) { 517 /* received data for the first time => send update to user */ 518 bcm_rx_update_and_send(op, lcf, rxdata); 519 return; 520 } 521 522 /* do a real check in CAN frame data section */ 523 for (i = 0; i < rxdata->len; i += 8) { 524 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 525 (get_u64(cf, i) & get_u64(lcf, i))) { 526 bcm_rx_update_and_send(op, lcf, rxdata); 527 return; 528 } 529 } 530 531 if (op->flags & RX_CHECK_DLC) { 532 /* do a real check in CAN frame length */ 533 if (rxdata->len != lcf->len) { 534 bcm_rx_update_and_send(op, lcf, rxdata); 535 return; 536 } 537 } 538 } 539 540 /* 541 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 542 */ 543 static void bcm_rx_starttimer(struct bcm_op *op) 544 { 545 if (op->flags & RX_NO_AUTOTIMER) 546 return; 547 548 if (op->kt_ival1) 549 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); 550 } 551 552 static void bcm_rx_timeout_tsklet(unsigned long data) 553 { 554 struct bcm_op *op = (struct bcm_op *)data; 555 struct bcm_msg_head msg_head; 556 557 /* create notification to user */ 558 msg_head.opcode = RX_TIMEOUT; 559 msg_head.flags = op->flags; 560 msg_head.count = op->count; 561 msg_head.ival1 = op->ival1; 562 msg_head.ival2 = op->ival2; 563 msg_head.can_id = op->can_id; 564 msg_head.nframes = 0; 565 566 bcm_send_to_user(op, &msg_head, NULL, 0); 567 } 568 569 /* 570 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out 571 */ 572 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 573 { 574 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 575 576 /* schedule before NET_RX_SOFTIRQ */ 577 tasklet_hi_schedule(&op->tsklet); 578 579 /* no restart of the timer is done here! */ 580 581 /* if user wants to be informed, when cyclic CAN-Messages come back */ 582 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 583 /* clear received CAN frames to indicate 'nothing received' */ 584 memset(op->last_frames, 0, op->nframes * op->cfsiz); 585 } 586 587 return HRTIMER_NORESTART; 588 } 589 590 /* 591 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 592 */ 593 static inline int bcm_rx_do_flush(struct bcm_op *op, int update, 594 unsigned int index) 595 { 596 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 597 598 if ((op->last_frames) && (lcf->flags & RX_THR)) { 599 if (update) 600 bcm_rx_changed(op, lcf); 601 return 1; 602 } 603 return 0; 604 } 605 606 /* 607 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 608 * 609 * update == 0 : just check if throttled data is available (any irq context) 610 * update == 1 : check and send throttled data to userspace (soft_irq context) 611 */ 612 static int bcm_rx_thr_flush(struct bcm_op *op, int update) 613 { 614 int updated = 0; 615 616 if (op->nframes > 1) { 617 unsigned int i; 618 619 /* for MUX filter we start at index 1 */ 620 for (i = 1; i < op->nframes; i++) 621 updated += bcm_rx_do_flush(op, update, i); 622 623 } else { 624 /* for RX_FILTER_ID and simple filter */ 625 updated += bcm_rx_do_flush(op, update, 0); 626 } 627 628 return updated; 629 } 630 631 static void bcm_rx_thr_tsklet(unsigned long data) 632 { 633 struct bcm_op *op = (struct bcm_op *)data; 634 635 /* push the changed data to the userspace */ 636 bcm_rx_thr_flush(op, 1); 637 } 638 639 /* 640 * bcm_rx_thr_handler - the time for blocked content updates is over now: 641 * Check for throttled data and send it to the userspace 642 */ 643 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 644 { 645 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 646 647 tasklet_schedule(&op->thrtsklet); 648 649 if (bcm_rx_thr_flush(op, 0)) { 650 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); 651 return HRTIMER_RESTART; 652 } else { 653 /* rearm throttle handling */ 654 op->kt_lastmsg = 0; 655 return HRTIMER_NORESTART; 656 } 657 } 658 659 /* 660 * bcm_rx_handler - handle a CAN frame reception 661 */ 662 static void bcm_rx_handler(struct sk_buff *skb, void *data) 663 { 664 struct bcm_op *op = (struct bcm_op *)data; 665 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 666 unsigned int i; 667 668 if (op->can_id != rxframe->can_id) 669 return; 670 671 /* make sure to handle the correct frame type (CAN / CAN FD) */ 672 if (skb->len != op->cfsiz) 673 return; 674 675 /* disable timeout */ 676 hrtimer_cancel(&op->timer); 677 678 /* save rx timestamp */ 679 op->rx_stamp = skb->tstamp; 680 /* save originator for recvfrom() */ 681 op->rx_ifindex = skb->dev->ifindex; 682 /* update statistics */ 683 op->frames_abs++; 684 685 if (op->flags & RX_RTR_FRAME) { 686 /* send reply for RTR-request (placed in op->frames[0]) */ 687 bcm_can_tx(op); 688 return; 689 } 690 691 if (op->flags & RX_FILTER_ID) { 692 /* the easiest case */ 693 bcm_rx_update_and_send(op, op->last_frames, rxframe); 694 goto rx_starttimer; 695 } 696 697 if (op->nframes == 1) { 698 /* simple compare with index 0 */ 699 bcm_rx_cmp_to_index(op, 0, rxframe); 700 goto rx_starttimer; 701 } 702 703 if (op->nframes > 1) { 704 /* 705 * multiplex compare 706 * 707 * find the first multiplex mask that fits. 708 * Remark: The MUX-mask is stored in index 0 - but only the 709 * first 64 bits of the frame data[] are relevant (CAN FD) 710 */ 711 712 for (i = 1; i < op->nframes; i++) { 713 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 714 (get_u64(op->frames, 0) & 715 get_u64(op->frames + op->cfsiz * i, 0))) { 716 bcm_rx_cmp_to_index(op, i, rxframe); 717 break; 718 } 719 } 720 } 721 722 rx_starttimer: 723 bcm_rx_starttimer(op); 724 } 725 726 /* 727 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 728 */ 729 static struct bcm_op *bcm_find_op(struct list_head *ops, 730 struct bcm_msg_head *mh, int ifindex) 731 { 732 struct bcm_op *op; 733 734 list_for_each_entry(op, ops, list) { 735 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 736 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 737 return op; 738 } 739 740 return NULL; 741 } 742 743 static void bcm_remove_op(struct bcm_op *op) 744 { 745 if (op->tsklet.func) { 746 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) || 747 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) || 748 hrtimer_active(&op->timer)) { 749 hrtimer_cancel(&op->timer); 750 tasklet_kill(&op->tsklet); 751 } 752 } 753 754 if (op->thrtsklet.func) { 755 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) || 756 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) || 757 hrtimer_active(&op->thrtimer)) { 758 hrtimer_cancel(&op->thrtimer); 759 tasklet_kill(&op->thrtsklet); 760 } 761 } 762 763 if ((op->frames) && (op->frames != &op->sframe)) 764 kfree(op->frames); 765 766 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 767 kfree(op->last_frames); 768 769 kfree(op); 770 } 771 772 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 773 { 774 if (op->rx_reg_dev == dev) { 775 can_rx_unregister(dev_net(dev), dev, op->can_id, 776 REGMASK(op->can_id), bcm_rx_handler, op); 777 778 /* mark as removed subscription */ 779 op->rx_reg_dev = NULL; 780 } else 781 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 782 "mismatch %p %p\n", op->rx_reg_dev, dev); 783 } 784 785 /* 786 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 787 */ 788 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 789 int ifindex) 790 { 791 struct bcm_op *op, *n; 792 793 list_for_each_entry_safe(op, n, ops, list) { 794 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 795 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 796 797 /* 798 * Don't care if we're bound or not (due to netdev 799 * problems) can_rx_unregister() is always a save 800 * thing to do here. 801 */ 802 if (op->ifindex) { 803 /* 804 * Only remove subscriptions that had not 805 * been removed due to NETDEV_UNREGISTER 806 * in bcm_notifier() 807 */ 808 if (op->rx_reg_dev) { 809 struct net_device *dev; 810 811 dev = dev_get_by_index(sock_net(op->sk), 812 op->ifindex); 813 if (dev) { 814 bcm_rx_unreg(dev, op); 815 dev_put(dev); 816 } 817 } 818 } else 819 can_rx_unregister(sock_net(op->sk), NULL, 820 op->can_id, 821 REGMASK(op->can_id), 822 bcm_rx_handler, op); 823 824 list_del(&op->list); 825 bcm_remove_op(op); 826 return 1; /* done */ 827 } 828 } 829 830 return 0; /* not found */ 831 } 832 833 /* 834 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 835 */ 836 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 837 int ifindex) 838 { 839 struct bcm_op *op, *n; 840 841 list_for_each_entry_safe(op, n, ops, list) { 842 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 843 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 844 list_del(&op->list); 845 bcm_remove_op(op); 846 return 1; /* done */ 847 } 848 } 849 850 return 0; /* not found */ 851 } 852 853 /* 854 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 855 */ 856 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 857 int ifindex) 858 { 859 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 860 861 if (!op) 862 return -EINVAL; 863 864 /* put current values into msg_head */ 865 msg_head->flags = op->flags; 866 msg_head->count = op->count; 867 msg_head->ival1 = op->ival1; 868 msg_head->ival2 = op->ival2; 869 msg_head->nframes = op->nframes; 870 871 bcm_send_to_user(op, msg_head, op->frames, 0); 872 873 return MHSIZ; 874 } 875 876 /* 877 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 878 */ 879 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 880 int ifindex, struct sock *sk) 881 { 882 struct bcm_sock *bo = bcm_sk(sk); 883 struct bcm_op *op; 884 struct canfd_frame *cf; 885 unsigned int i; 886 int err; 887 888 /* we need a real device to send frames */ 889 if (!ifindex) 890 return -ENODEV; 891 892 /* check nframes boundaries - we need at least one CAN frame */ 893 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 894 return -EINVAL; 895 896 /* check timeval limitations */ 897 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 898 return -EINVAL; 899 900 /* check the given can_id */ 901 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 902 if (op) { 903 /* update existing BCM operation */ 904 905 /* 906 * Do we need more space for the CAN frames than currently 907 * allocated? -> This is a _really_ unusual use-case and 908 * therefore (complexity / locking) it is not supported. 909 */ 910 if (msg_head->nframes > op->nframes) 911 return -E2BIG; 912 913 /* update CAN frames content */ 914 for (i = 0; i < msg_head->nframes; i++) { 915 916 cf = op->frames + op->cfsiz * i; 917 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 918 919 if (op->flags & CAN_FD_FRAME) { 920 if (cf->len > 64) 921 err = -EINVAL; 922 } else { 923 if (cf->len > 8) 924 err = -EINVAL; 925 } 926 927 if (err < 0) 928 return err; 929 930 if (msg_head->flags & TX_CP_CAN_ID) { 931 /* copy can_id into frame */ 932 cf->can_id = msg_head->can_id; 933 } 934 } 935 op->flags = msg_head->flags; 936 937 } else { 938 /* insert new BCM operation for the given can_id */ 939 940 op = kzalloc(OPSIZ, GFP_KERNEL); 941 if (!op) 942 return -ENOMEM; 943 944 op->can_id = msg_head->can_id; 945 op->cfsiz = CFSIZ(msg_head->flags); 946 op->flags = msg_head->flags; 947 948 /* create array for CAN frames and copy the data */ 949 if (msg_head->nframes > 1) { 950 op->frames = kmalloc_array(msg_head->nframes, 951 op->cfsiz, 952 GFP_KERNEL); 953 if (!op->frames) { 954 kfree(op); 955 return -ENOMEM; 956 } 957 } else 958 op->frames = &op->sframe; 959 960 for (i = 0; i < msg_head->nframes; i++) { 961 962 cf = op->frames + op->cfsiz * i; 963 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 964 965 if (op->flags & CAN_FD_FRAME) { 966 if (cf->len > 64) 967 err = -EINVAL; 968 } else { 969 if (cf->len > 8) 970 err = -EINVAL; 971 } 972 973 if (err < 0) { 974 if (op->frames != &op->sframe) 975 kfree(op->frames); 976 kfree(op); 977 return err; 978 } 979 980 if (msg_head->flags & TX_CP_CAN_ID) { 981 /* copy can_id into frame */ 982 cf->can_id = msg_head->can_id; 983 } 984 } 985 986 /* tx_ops never compare with previous received messages */ 987 op->last_frames = NULL; 988 989 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 990 op->sk = sk; 991 op->ifindex = ifindex; 992 993 /* initialize uninitialized (kzalloc) structure */ 994 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 995 op->timer.function = bcm_tx_timeout_handler; 996 997 /* initialize tasklet for tx countevent notification */ 998 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, 999 (unsigned long) op); 1000 1001 /* currently unused in tx_ops */ 1002 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1003 1004 /* add this bcm_op to the list of the tx_ops */ 1005 list_add(&op->list, &bo->tx_ops); 1006 1007 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 1008 1009 if (op->nframes != msg_head->nframes) { 1010 op->nframes = msg_head->nframes; 1011 /* start multiple frame transmission with index 0 */ 1012 op->currframe = 0; 1013 } 1014 1015 /* check flags */ 1016 1017 if (op->flags & TX_RESET_MULTI_IDX) { 1018 /* start multiple frame transmission with index 0 */ 1019 op->currframe = 0; 1020 } 1021 1022 if (op->flags & SETTIMER) { 1023 /* set timer values */ 1024 op->count = msg_head->count; 1025 op->ival1 = msg_head->ival1; 1026 op->ival2 = msg_head->ival2; 1027 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1028 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1029 1030 /* disable an active timer due to zero values? */ 1031 if (!op->kt_ival1 && !op->kt_ival2) 1032 hrtimer_cancel(&op->timer); 1033 } 1034 1035 if (op->flags & STARTTIMER) { 1036 hrtimer_cancel(&op->timer); 1037 /* spec: send CAN frame when starting timer */ 1038 op->flags |= TX_ANNOUNCE; 1039 } 1040 1041 if (op->flags & TX_ANNOUNCE) { 1042 bcm_can_tx(op); 1043 if (op->count) 1044 op->count--; 1045 } 1046 1047 if (op->flags & STARTTIMER) 1048 bcm_tx_start_timer(op); 1049 1050 return msg_head->nframes * op->cfsiz + MHSIZ; 1051 } 1052 1053 /* 1054 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1055 */ 1056 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1057 int ifindex, struct sock *sk) 1058 { 1059 struct bcm_sock *bo = bcm_sk(sk); 1060 struct bcm_op *op; 1061 int do_rx_register; 1062 int err = 0; 1063 1064 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1065 /* be robust against wrong usage ... */ 1066 msg_head->flags |= RX_FILTER_ID; 1067 /* ignore trailing garbage */ 1068 msg_head->nframes = 0; 1069 } 1070 1071 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1072 if (msg_head->nframes > MAX_NFRAMES + 1) 1073 return -EINVAL; 1074 1075 if ((msg_head->flags & RX_RTR_FRAME) && 1076 ((msg_head->nframes != 1) || 1077 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1078 return -EINVAL; 1079 1080 /* check timeval limitations */ 1081 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1082 return -EINVAL; 1083 1084 /* check the given can_id */ 1085 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1086 if (op) { 1087 /* update existing BCM operation */ 1088 1089 /* 1090 * Do we need more space for the CAN frames than currently 1091 * allocated? -> This is a _really_ unusual use-case and 1092 * therefore (complexity / locking) it is not supported. 1093 */ 1094 if (msg_head->nframes > op->nframes) 1095 return -E2BIG; 1096 1097 if (msg_head->nframes) { 1098 /* update CAN frames content */ 1099 err = memcpy_from_msg(op->frames, msg, 1100 msg_head->nframes * op->cfsiz); 1101 if (err < 0) 1102 return err; 1103 1104 /* clear last_frames to indicate 'nothing received' */ 1105 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1106 } 1107 1108 op->nframes = msg_head->nframes; 1109 op->flags = msg_head->flags; 1110 1111 /* Only an update -> do not call can_rx_register() */ 1112 do_rx_register = 0; 1113 1114 } else { 1115 /* insert new BCM operation for the given can_id */ 1116 op = kzalloc(OPSIZ, GFP_KERNEL); 1117 if (!op) 1118 return -ENOMEM; 1119 1120 op->can_id = msg_head->can_id; 1121 op->nframes = msg_head->nframes; 1122 op->cfsiz = CFSIZ(msg_head->flags); 1123 op->flags = msg_head->flags; 1124 1125 if (msg_head->nframes > 1) { 1126 /* create array for CAN frames and copy the data */ 1127 op->frames = kmalloc_array(msg_head->nframes, 1128 op->cfsiz, 1129 GFP_KERNEL); 1130 if (!op->frames) { 1131 kfree(op); 1132 return -ENOMEM; 1133 } 1134 1135 /* create and init array for received CAN frames */ 1136 op->last_frames = kcalloc(msg_head->nframes, 1137 op->cfsiz, 1138 GFP_KERNEL); 1139 if (!op->last_frames) { 1140 kfree(op->frames); 1141 kfree(op); 1142 return -ENOMEM; 1143 } 1144 1145 } else { 1146 op->frames = &op->sframe; 1147 op->last_frames = &op->last_sframe; 1148 } 1149 1150 if (msg_head->nframes) { 1151 err = memcpy_from_msg(op->frames, msg, 1152 msg_head->nframes * op->cfsiz); 1153 if (err < 0) { 1154 if (op->frames != &op->sframe) 1155 kfree(op->frames); 1156 if (op->last_frames != &op->last_sframe) 1157 kfree(op->last_frames); 1158 kfree(op); 1159 return err; 1160 } 1161 } 1162 1163 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1164 op->sk = sk; 1165 op->ifindex = ifindex; 1166 1167 /* ifindex for timeout events w/o previous frame reception */ 1168 op->rx_ifindex = ifindex; 1169 1170 /* initialize uninitialized (kzalloc) structure */ 1171 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1172 op->timer.function = bcm_rx_timeout_handler; 1173 1174 /* initialize tasklet for rx timeout notification */ 1175 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, 1176 (unsigned long) op); 1177 1178 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1179 op->thrtimer.function = bcm_rx_thr_handler; 1180 1181 /* initialize tasklet for rx throttle handling */ 1182 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, 1183 (unsigned long) op); 1184 1185 /* add this bcm_op to the list of the rx_ops */ 1186 list_add(&op->list, &bo->rx_ops); 1187 1188 /* call can_rx_register() */ 1189 do_rx_register = 1; 1190 1191 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1192 1193 /* check flags */ 1194 1195 if (op->flags & RX_RTR_FRAME) { 1196 struct canfd_frame *frame0 = op->frames; 1197 1198 /* no timers in RTR-mode */ 1199 hrtimer_cancel(&op->thrtimer); 1200 hrtimer_cancel(&op->timer); 1201 1202 /* 1203 * funny feature in RX(!)_SETUP only for RTR-mode: 1204 * copy can_id into frame BUT without RTR-flag to 1205 * prevent a full-load-loopback-test ... ;-] 1206 */ 1207 if ((op->flags & TX_CP_CAN_ID) || 1208 (frame0->can_id == op->can_id)) 1209 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1210 1211 } else { 1212 if (op->flags & SETTIMER) { 1213 1214 /* set timer value */ 1215 op->ival1 = msg_head->ival1; 1216 op->ival2 = msg_head->ival2; 1217 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1218 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1219 1220 /* disable an active timer due to zero value? */ 1221 if (!op->kt_ival1) 1222 hrtimer_cancel(&op->timer); 1223 1224 /* 1225 * In any case cancel the throttle timer, flush 1226 * potentially blocked msgs and reset throttle handling 1227 */ 1228 op->kt_lastmsg = 0; 1229 hrtimer_cancel(&op->thrtimer); 1230 bcm_rx_thr_flush(op, 1); 1231 } 1232 1233 if ((op->flags & STARTTIMER) && op->kt_ival1) 1234 hrtimer_start(&op->timer, op->kt_ival1, 1235 HRTIMER_MODE_REL); 1236 } 1237 1238 /* now we can register for can_ids, if we added a new bcm_op */ 1239 if (do_rx_register) { 1240 if (ifindex) { 1241 struct net_device *dev; 1242 1243 dev = dev_get_by_index(sock_net(sk), ifindex); 1244 if (dev) { 1245 err = can_rx_register(sock_net(sk), dev, 1246 op->can_id, 1247 REGMASK(op->can_id), 1248 bcm_rx_handler, op, 1249 "bcm", sk); 1250 1251 op->rx_reg_dev = dev; 1252 dev_put(dev); 1253 } 1254 1255 } else 1256 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1257 REGMASK(op->can_id), 1258 bcm_rx_handler, op, "bcm", sk); 1259 if (err) { 1260 /* this bcm rx op is broken -> remove it */ 1261 list_del(&op->list); 1262 bcm_remove_op(op); 1263 return err; 1264 } 1265 } 1266 1267 return msg_head->nframes * op->cfsiz + MHSIZ; 1268 } 1269 1270 /* 1271 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1272 */ 1273 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1274 int cfsiz) 1275 { 1276 struct sk_buff *skb; 1277 struct net_device *dev; 1278 int err; 1279 1280 /* we need a real device to send frames */ 1281 if (!ifindex) 1282 return -ENODEV; 1283 1284 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1285 if (!skb) 1286 return -ENOMEM; 1287 1288 can_skb_reserve(skb); 1289 1290 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1291 if (err < 0) { 1292 kfree_skb(skb); 1293 return err; 1294 } 1295 1296 dev = dev_get_by_index(sock_net(sk), ifindex); 1297 if (!dev) { 1298 kfree_skb(skb); 1299 return -ENODEV; 1300 } 1301 1302 can_skb_prv(skb)->ifindex = dev->ifindex; 1303 can_skb_prv(skb)->skbcnt = 0; 1304 skb->dev = dev; 1305 can_skb_set_owner(skb, sk); 1306 err = can_send(skb, 1); /* send with loopback */ 1307 dev_put(dev); 1308 1309 if (err) 1310 return err; 1311 1312 return cfsiz + MHSIZ; 1313 } 1314 1315 /* 1316 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1317 */ 1318 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1319 { 1320 struct sock *sk = sock->sk; 1321 struct bcm_sock *bo = bcm_sk(sk); 1322 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1323 struct bcm_msg_head msg_head; 1324 int cfsiz; 1325 int ret; /* read bytes or error codes as return value */ 1326 1327 if (!bo->bound) 1328 return -ENOTCONN; 1329 1330 /* check for valid message length from userspace */ 1331 if (size < MHSIZ) 1332 return -EINVAL; 1333 1334 /* read message head information */ 1335 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1336 if (ret < 0) 1337 return ret; 1338 1339 cfsiz = CFSIZ(msg_head.flags); 1340 if ((size - MHSIZ) % cfsiz) 1341 return -EINVAL; 1342 1343 /* check for alternative ifindex for this bcm_op */ 1344 1345 if (!ifindex && msg->msg_name) { 1346 /* no bound device as default => check msg_name */ 1347 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1348 1349 if (msg->msg_namelen < sizeof(*addr)) 1350 return -EINVAL; 1351 1352 if (addr->can_family != AF_CAN) 1353 return -EINVAL; 1354 1355 /* ifindex from sendto() */ 1356 ifindex = addr->can_ifindex; 1357 1358 if (ifindex) { 1359 struct net_device *dev; 1360 1361 dev = dev_get_by_index(sock_net(sk), ifindex); 1362 if (!dev) 1363 return -ENODEV; 1364 1365 if (dev->type != ARPHRD_CAN) { 1366 dev_put(dev); 1367 return -ENODEV; 1368 } 1369 1370 dev_put(dev); 1371 } 1372 } 1373 1374 lock_sock(sk); 1375 1376 switch (msg_head.opcode) { 1377 1378 case TX_SETUP: 1379 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1380 break; 1381 1382 case RX_SETUP: 1383 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1384 break; 1385 1386 case TX_DELETE: 1387 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1388 ret = MHSIZ; 1389 else 1390 ret = -EINVAL; 1391 break; 1392 1393 case RX_DELETE: 1394 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1395 ret = MHSIZ; 1396 else 1397 ret = -EINVAL; 1398 break; 1399 1400 case TX_READ: 1401 /* reuse msg_head for the reply to TX_READ */ 1402 msg_head.opcode = TX_STATUS; 1403 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1404 break; 1405 1406 case RX_READ: 1407 /* reuse msg_head for the reply to RX_READ */ 1408 msg_head.opcode = RX_STATUS; 1409 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1410 break; 1411 1412 case TX_SEND: 1413 /* we need exactly one CAN frame behind the msg head */ 1414 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1415 ret = -EINVAL; 1416 else 1417 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1418 break; 1419 1420 default: 1421 ret = -EINVAL; 1422 break; 1423 } 1424 1425 release_sock(sk); 1426 1427 return ret; 1428 } 1429 1430 /* 1431 * notification handler for netdevice status changes 1432 */ 1433 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1434 void *ptr) 1435 { 1436 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1437 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier); 1438 struct sock *sk = &bo->sk; 1439 struct bcm_op *op; 1440 int notify_enodev = 0; 1441 1442 if (!net_eq(dev_net(dev), sock_net(sk))) 1443 return NOTIFY_DONE; 1444 1445 if (dev->type != ARPHRD_CAN) 1446 return NOTIFY_DONE; 1447 1448 switch (msg) { 1449 1450 case NETDEV_UNREGISTER: 1451 lock_sock(sk); 1452 1453 /* remove device specific receive entries */ 1454 list_for_each_entry(op, &bo->rx_ops, list) 1455 if (op->rx_reg_dev == dev) 1456 bcm_rx_unreg(dev, op); 1457 1458 /* remove device reference, if this is our bound device */ 1459 if (bo->bound && bo->ifindex == dev->ifindex) { 1460 bo->bound = 0; 1461 bo->ifindex = 0; 1462 notify_enodev = 1; 1463 } 1464 1465 release_sock(sk); 1466 1467 if (notify_enodev) { 1468 sk->sk_err = ENODEV; 1469 if (!sock_flag(sk, SOCK_DEAD)) 1470 sk->sk_error_report(sk); 1471 } 1472 break; 1473 1474 case NETDEV_DOWN: 1475 if (bo->bound && bo->ifindex == dev->ifindex) { 1476 sk->sk_err = ENETDOWN; 1477 if (!sock_flag(sk, SOCK_DEAD)) 1478 sk->sk_error_report(sk); 1479 } 1480 } 1481 1482 return NOTIFY_DONE; 1483 } 1484 1485 /* 1486 * initial settings for all BCM sockets to be set at socket creation time 1487 */ 1488 static int bcm_init(struct sock *sk) 1489 { 1490 struct bcm_sock *bo = bcm_sk(sk); 1491 1492 bo->bound = 0; 1493 bo->ifindex = 0; 1494 bo->dropped_usr_msgs = 0; 1495 bo->bcm_proc_read = NULL; 1496 1497 INIT_LIST_HEAD(&bo->tx_ops); 1498 INIT_LIST_HEAD(&bo->rx_ops); 1499 1500 /* set notifier */ 1501 bo->notifier.notifier_call = bcm_notifier; 1502 1503 register_netdevice_notifier(&bo->notifier); 1504 1505 return 0; 1506 } 1507 1508 /* 1509 * standard socket functions 1510 */ 1511 static int bcm_release(struct socket *sock) 1512 { 1513 struct sock *sk = sock->sk; 1514 struct net *net; 1515 struct bcm_sock *bo; 1516 struct bcm_op *op, *next; 1517 1518 if (!sk) 1519 return 0; 1520 1521 net = sock_net(sk); 1522 bo = bcm_sk(sk); 1523 1524 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1525 1526 unregister_netdevice_notifier(&bo->notifier); 1527 1528 lock_sock(sk); 1529 1530 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1531 bcm_remove_op(op); 1532 1533 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1534 /* 1535 * Don't care if we're bound or not (due to netdev problems) 1536 * can_rx_unregister() is always a save thing to do here. 1537 */ 1538 if (op->ifindex) { 1539 /* 1540 * Only remove subscriptions that had not 1541 * been removed due to NETDEV_UNREGISTER 1542 * in bcm_notifier() 1543 */ 1544 if (op->rx_reg_dev) { 1545 struct net_device *dev; 1546 1547 dev = dev_get_by_index(net, op->ifindex); 1548 if (dev) { 1549 bcm_rx_unreg(dev, op); 1550 dev_put(dev); 1551 } 1552 } 1553 } else 1554 can_rx_unregister(net, NULL, op->can_id, 1555 REGMASK(op->can_id), 1556 bcm_rx_handler, op); 1557 1558 bcm_remove_op(op); 1559 } 1560 1561 #if IS_ENABLED(CONFIG_PROC_FS) 1562 /* remove procfs entry */ 1563 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1564 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1565 #endif /* CONFIG_PROC_FS */ 1566 1567 /* remove device reference */ 1568 if (bo->bound) { 1569 bo->bound = 0; 1570 bo->ifindex = 0; 1571 } 1572 1573 sock_orphan(sk); 1574 sock->sk = NULL; 1575 1576 release_sock(sk); 1577 sock_put(sk); 1578 1579 return 0; 1580 } 1581 1582 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1583 int flags) 1584 { 1585 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1586 struct sock *sk = sock->sk; 1587 struct bcm_sock *bo = bcm_sk(sk); 1588 struct net *net = sock_net(sk); 1589 int ret = 0; 1590 1591 if (len < sizeof(*addr)) 1592 return -EINVAL; 1593 1594 lock_sock(sk); 1595 1596 if (bo->bound) { 1597 ret = -EISCONN; 1598 goto fail; 1599 } 1600 1601 /* bind a device to this socket */ 1602 if (addr->can_ifindex) { 1603 struct net_device *dev; 1604 1605 dev = dev_get_by_index(net, addr->can_ifindex); 1606 if (!dev) { 1607 ret = -ENODEV; 1608 goto fail; 1609 } 1610 if (dev->type != ARPHRD_CAN) { 1611 dev_put(dev); 1612 ret = -ENODEV; 1613 goto fail; 1614 } 1615 1616 bo->ifindex = dev->ifindex; 1617 dev_put(dev); 1618 1619 } else { 1620 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1621 bo->ifindex = 0; 1622 } 1623 1624 #if IS_ENABLED(CONFIG_PROC_FS) 1625 if (net->can.bcmproc_dir) { 1626 /* unique socket address as filename */ 1627 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1628 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1629 net->can.bcmproc_dir, 1630 bcm_proc_show, sk); 1631 if (!bo->bcm_proc_read) { 1632 ret = -ENOMEM; 1633 goto fail; 1634 } 1635 } 1636 #endif /* CONFIG_PROC_FS */ 1637 1638 bo->bound = 1; 1639 1640 fail: 1641 release_sock(sk); 1642 1643 return ret; 1644 } 1645 1646 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1647 int flags) 1648 { 1649 struct sock *sk = sock->sk; 1650 struct sk_buff *skb; 1651 int error = 0; 1652 int noblock; 1653 int err; 1654 1655 noblock = flags & MSG_DONTWAIT; 1656 flags &= ~MSG_DONTWAIT; 1657 skb = skb_recv_datagram(sk, flags, noblock, &error); 1658 if (!skb) 1659 return error; 1660 1661 if (skb->len < size) 1662 size = skb->len; 1663 1664 err = memcpy_to_msg(msg, skb->data, size); 1665 if (err < 0) { 1666 skb_free_datagram(sk, skb); 1667 return err; 1668 } 1669 1670 sock_recv_ts_and_drops(msg, sk, skb); 1671 1672 if (msg->msg_name) { 1673 __sockaddr_check_size(sizeof(struct sockaddr_can)); 1674 msg->msg_namelen = sizeof(struct sockaddr_can); 1675 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1676 } 1677 1678 skb_free_datagram(sk, skb); 1679 1680 return size; 1681 } 1682 1683 int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1684 unsigned long arg) 1685 { 1686 /* no ioctls for socket layer -> hand it down to NIC layer */ 1687 return -ENOIOCTLCMD; 1688 } 1689 1690 static const struct proto_ops bcm_ops = { 1691 .family = PF_CAN, 1692 .release = bcm_release, 1693 .bind = sock_no_bind, 1694 .connect = bcm_connect, 1695 .socketpair = sock_no_socketpair, 1696 .accept = sock_no_accept, 1697 .getname = sock_no_getname, 1698 .poll = datagram_poll, 1699 .ioctl = bcm_sock_no_ioctlcmd, 1700 .gettstamp = sock_gettstamp, 1701 .listen = sock_no_listen, 1702 .shutdown = sock_no_shutdown, 1703 .setsockopt = sock_no_setsockopt, 1704 .getsockopt = sock_no_getsockopt, 1705 .sendmsg = bcm_sendmsg, 1706 .recvmsg = bcm_recvmsg, 1707 .mmap = sock_no_mmap, 1708 .sendpage = sock_no_sendpage, 1709 }; 1710 1711 static struct proto bcm_proto __read_mostly = { 1712 .name = "CAN_BCM", 1713 .owner = THIS_MODULE, 1714 .obj_size = sizeof(struct bcm_sock), 1715 .init = bcm_init, 1716 }; 1717 1718 static const struct can_proto bcm_can_proto = { 1719 .type = SOCK_DGRAM, 1720 .protocol = CAN_BCM, 1721 .ops = &bcm_ops, 1722 .prot = &bcm_proto, 1723 }; 1724 1725 static int canbcm_pernet_init(struct net *net) 1726 { 1727 #if IS_ENABLED(CONFIG_PROC_FS) 1728 /* create /proc/net/can-bcm directory */ 1729 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1730 #endif /* CONFIG_PROC_FS */ 1731 1732 return 0; 1733 } 1734 1735 static void canbcm_pernet_exit(struct net *net) 1736 { 1737 #if IS_ENABLED(CONFIG_PROC_FS) 1738 /* remove /proc/net/can-bcm directory */ 1739 if (net->can.bcmproc_dir) 1740 remove_proc_entry("can-bcm", net->proc_net); 1741 #endif /* CONFIG_PROC_FS */ 1742 } 1743 1744 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1745 .init = canbcm_pernet_init, 1746 .exit = canbcm_pernet_exit, 1747 }; 1748 1749 static int __init bcm_module_init(void) 1750 { 1751 int err; 1752 1753 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n"); 1754 1755 err = can_proto_register(&bcm_can_proto); 1756 if (err < 0) { 1757 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1758 return err; 1759 } 1760 1761 register_pernet_subsys(&canbcm_pernet_ops); 1762 return 0; 1763 } 1764 1765 static void __exit bcm_module_exit(void) 1766 { 1767 can_proto_unregister(&bcm_can_proto); 1768 unregister_pernet_subsys(&canbcm_pernet_ops); 1769 } 1770 1771 module_init(bcm_module_init); 1772 module_exit(bcm_module_exit); 1773