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 <linux/spinlock.h> 62 #include <net/sock.h> 63 #include <net/net_namespace.h> 64 65 /* 66 * To send multiple CAN frame content within TX_SETUP or to filter 67 * CAN messages with multiplex index within RX_SETUP, the number of 68 * different filters is limited to 256 due to the one byte index value. 69 */ 70 #define MAX_NFRAMES 256 71 72 /* limit timers to 400 days for sending/timeouts */ 73 #define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60) 74 75 /* use of last_frames[index].flags */ 76 #define RX_LOCAL 0x10 /* frame was created on the local host */ 77 #define RX_OWN 0x20 /* frame was sent via the socket it was received on */ 78 #define RX_RECV 0x40 /* received data for this element */ 79 #define RX_THR 0x80 /* element not been sent due to throttle feature */ 80 #define BCM_CAN_FLAGS_MASK 0x0F /* to clean private flags after usage */ 81 82 /* get best masking value for can_rx_register() for a given single can_id */ 83 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ 84 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ 85 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) 86 87 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol"); 88 MODULE_LICENSE("Dual BSD/GPL"); 89 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 90 MODULE_ALIAS("can-proto-2"); 91 92 #define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) 93 94 /* 95 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is 96 * 64 bit aligned so the offset has to be multiples of 8 which is ensured 97 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler(). 98 */ 99 static inline u64 get_u64(const struct canfd_frame *cp, int offset) 100 { 101 return *(u64 *)(cp->data + offset); 102 } 103 104 struct bcm_op { 105 struct list_head list; 106 struct rcu_head rcu; 107 int ifindex; 108 canid_t can_id; 109 u32 flags; 110 unsigned long frames_abs, frames_filtered; 111 struct bcm_timeval ival1, ival2; 112 struct hrtimer timer, thrtimer; 113 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; 114 int rx_ifindex; 115 int cfsiz; 116 u32 count; 117 u32 nframes; 118 u32 currframe; 119 /* void pointers to arrays of struct can[fd]_frame */ 120 void *frames; 121 void *last_frames; 122 struct canfd_frame sframe; 123 struct canfd_frame last_sframe; 124 struct sock *sk; 125 struct net_device *rx_reg_dev; 126 spinlock_t bcm_tx_lock; /* protect currframe/count in runtime updates */ 127 }; 128 129 struct bcm_sock { 130 struct sock sk; 131 int bound; 132 int ifindex; 133 struct list_head notifier; 134 struct list_head rx_ops; 135 struct list_head tx_ops; 136 unsigned long dropped_usr_msgs; 137 struct proc_dir_entry *bcm_proc_read; 138 char procname [32]; /* inode number in decimal with \0 */ 139 }; 140 141 static LIST_HEAD(bcm_notifier_list); 142 static DEFINE_SPINLOCK(bcm_notifier_lock); 143 static struct bcm_sock *bcm_busy_notifier; 144 145 /* Return pointer to store the extra msg flags for bcm_recvmsg(). 146 * We use the space of one unsigned int beyond the 'struct sockaddr_can' 147 * in skb->cb. 148 */ 149 static inline unsigned int *bcm_flags(struct sk_buff *skb) 150 { 151 /* return pointer after struct sockaddr_can */ 152 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]); 153 } 154 155 static inline struct bcm_sock *bcm_sk(const struct sock *sk) 156 { 157 return (struct bcm_sock *)sk; 158 } 159 160 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv) 161 { 162 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 163 } 164 165 /* check limitations for timeval provided by user */ 166 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head) 167 { 168 if ((msg_head->ival1.tv_sec < 0) || 169 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) || 170 (msg_head->ival1.tv_usec < 0) || 171 (msg_head->ival1.tv_usec >= USEC_PER_SEC) || 172 (msg_head->ival2.tv_sec < 0) || 173 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) || 174 (msg_head->ival2.tv_usec < 0) || 175 (msg_head->ival2.tv_usec >= USEC_PER_SEC)) 176 return true; 177 178 return false; 179 } 180 181 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU) 182 #define OPSIZ sizeof(struct bcm_op) 183 #define MHSIZ sizeof(struct bcm_msg_head) 184 185 /* 186 * procfs functions 187 */ 188 #if IS_ENABLED(CONFIG_PROC_FS) 189 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex) 190 { 191 struct net_device *dev; 192 193 if (!ifindex) 194 return "any"; 195 196 rcu_read_lock(); 197 dev = dev_get_by_index_rcu(net, ifindex); 198 if (dev) 199 strcpy(result, dev->name); 200 else 201 strcpy(result, "???"); 202 rcu_read_unlock(); 203 204 return result; 205 } 206 207 static int bcm_proc_show(struct seq_file *m, void *v) 208 { 209 char ifname[IFNAMSIZ]; 210 struct net *net = m->private; 211 struct sock *sk = (struct sock *)pde_data(m->file->f_inode); 212 struct bcm_sock *bo = bcm_sk(sk); 213 struct bcm_op *op; 214 215 seq_printf(m, ">>> socket %pK", sk->sk_socket); 216 seq_printf(m, " / sk %pK", sk); 217 seq_printf(m, " / bo %pK", bo); 218 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs); 219 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex)); 220 seq_printf(m, " <<<\n"); 221 222 rcu_read_lock(); 223 224 list_for_each_entry_rcu(op, &bo->rx_ops, list) { 225 226 unsigned long reduction; 227 228 /* print only active entries & prevent division by zero */ 229 if (!op->frames_abs) 230 continue; 231 232 seq_printf(m, "rx_op: %03X %-5s ", op->can_id, 233 bcm_proc_getifname(net, ifname, op->ifindex)); 234 235 if (op->flags & CAN_FD_FRAME) 236 seq_printf(m, "(%u)", op->nframes); 237 else 238 seq_printf(m, "[%u]", op->nframes); 239 240 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' '); 241 242 if (op->kt_ival1) 243 seq_printf(m, "timeo=%lld ", 244 (long long)ktime_to_us(op->kt_ival1)); 245 246 if (op->kt_ival2) 247 seq_printf(m, "thr=%lld ", 248 (long long)ktime_to_us(op->kt_ival2)); 249 250 seq_printf(m, "# recv %ld (%ld) => reduction: ", 251 op->frames_filtered, op->frames_abs); 252 253 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs; 254 255 seq_printf(m, "%s%ld%%\n", 256 (reduction == 100) ? "near " : "", reduction); 257 } 258 259 list_for_each_entry(op, &bo->tx_ops, list) { 260 261 seq_printf(m, "tx_op: %03X %s ", op->can_id, 262 bcm_proc_getifname(net, ifname, op->ifindex)); 263 264 if (op->flags & CAN_FD_FRAME) 265 seq_printf(m, "(%u) ", op->nframes); 266 else 267 seq_printf(m, "[%u] ", op->nframes); 268 269 if (op->kt_ival1) 270 seq_printf(m, "t1=%lld ", 271 (long long)ktime_to_us(op->kt_ival1)); 272 273 if (op->kt_ival2) 274 seq_printf(m, "t2=%lld ", 275 (long long)ktime_to_us(op->kt_ival2)); 276 277 seq_printf(m, "# sent %ld\n", op->frames_abs); 278 } 279 seq_putc(m, '\n'); 280 281 rcu_read_unlock(); 282 283 return 0; 284 } 285 #endif /* CONFIG_PROC_FS */ 286 287 /* 288 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface 289 * of the given bcm tx op 290 */ 291 static void bcm_can_tx(struct bcm_op *op) 292 { 293 struct sk_buff *skb; 294 struct net_device *dev; 295 struct canfd_frame *cf; 296 int err; 297 298 /* no target device? => exit */ 299 if (!op->ifindex) 300 return; 301 302 /* read currframe under lock protection */ 303 spin_lock_bh(&op->bcm_tx_lock); 304 cf = op->frames + op->cfsiz * op->currframe; 305 spin_unlock_bh(&op->bcm_tx_lock); 306 307 dev = dev_get_by_index(sock_net(op->sk), op->ifindex); 308 if (!dev) { 309 /* RFC: should this bcm_op remove itself here? */ 310 return; 311 } 312 313 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any()); 314 if (!skb) 315 goto out; 316 317 can_skb_reserve(skb); 318 can_skb_prv(skb)->ifindex = dev->ifindex; 319 can_skb_prv(skb)->skbcnt = 0; 320 321 skb_put_data(skb, cf, op->cfsiz); 322 323 /* send with loopback */ 324 skb->dev = dev; 325 can_skb_set_owner(skb, op->sk); 326 err = can_send(skb, 1); 327 328 /* update currframe and count under lock protection */ 329 spin_lock_bh(&op->bcm_tx_lock); 330 331 if (!err) 332 op->frames_abs++; 333 334 op->currframe++; 335 336 /* reached last frame? */ 337 if (op->currframe >= op->nframes) 338 op->currframe = 0; 339 340 if (op->count > 0) 341 op->count--; 342 343 spin_unlock_bh(&op->bcm_tx_lock); 344 out: 345 dev_put(dev); 346 } 347 348 /* 349 * bcm_send_to_user - send a BCM message to the userspace 350 * (consisting of bcm_msg_head + x CAN frames) 351 */ 352 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, 353 struct canfd_frame *frames, int has_timestamp) 354 { 355 struct sk_buff *skb; 356 struct canfd_frame *firstframe; 357 struct sockaddr_can *addr; 358 struct sock *sk = op->sk; 359 unsigned int datalen = head->nframes * op->cfsiz; 360 int err; 361 unsigned int *pflags; 362 363 skb = alloc_skb(sizeof(*head) + datalen, gfp_any()); 364 if (!skb) 365 return; 366 367 skb_put_data(skb, head, sizeof(*head)); 368 369 /* ensure space for sockaddr_can and msg flags */ 370 sock_skb_cb_check_size(sizeof(struct sockaddr_can) + 371 sizeof(unsigned int)); 372 373 /* initialize msg flags */ 374 pflags = bcm_flags(skb); 375 *pflags = 0; 376 377 if (head->nframes) { 378 /* CAN frames starting here */ 379 firstframe = (struct canfd_frame *)skb_tail_pointer(skb); 380 381 skb_put_data(skb, frames, datalen); 382 383 /* 384 * the BCM uses the flags-element of the canfd_frame 385 * structure for internal purposes. This is only 386 * relevant for updates that are generated by the 387 * BCM, where nframes is 1 388 */ 389 if (head->nframes == 1) { 390 if (firstframe->flags & RX_LOCAL) 391 *pflags |= MSG_DONTROUTE; 392 if (firstframe->flags & RX_OWN) 393 *pflags |= MSG_CONFIRM; 394 395 firstframe->flags &= BCM_CAN_FLAGS_MASK; 396 } 397 } 398 399 if (has_timestamp) { 400 /* restore rx timestamp */ 401 skb->tstamp = op->rx_stamp; 402 } 403 404 /* 405 * Put the datagram to the queue so that bcm_recvmsg() can 406 * get it from there. We need to pass the interface index to 407 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb 408 * containing the interface index. 409 */ 410 411 addr = (struct sockaddr_can *)skb->cb; 412 memset(addr, 0, sizeof(*addr)); 413 addr->can_family = AF_CAN; 414 addr->can_ifindex = op->rx_ifindex; 415 416 err = sock_queue_rcv_skb(sk, skb); 417 if (err < 0) { 418 struct bcm_sock *bo = bcm_sk(sk); 419 420 kfree_skb(skb); 421 /* don't care about overflows in this statistic */ 422 bo->dropped_usr_msgs++; 423 } 424 } 425 426 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt) 427 { 428 ktime_t ival; 429 430 if (op->kt_ival1 && op->count) 431 ival = op->kt_ival1; 432 else if (op->kt_ival2) 433 ival = op->kt_ival2; 434 else 435 return false; 436 437 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival)); 438 return true; 439 } 440 441 static void bcm_tx_start_timer(struct bcm_op *op) 442 { 443 if (bcm_tx_set_expiry(op, &op->timer)) 444 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT); 445 } 446 447 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */ 448 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) 449 { 450 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 451 struct bcm_msg_head msg_head; 452 453 if (op->kt_ival1 && (op->count > 0)) { 454 bcm_can_tx(op); 455 if (!op->count && (op->flags & TX_COUNTEVT)) { 456 457 /* create notification to user */ 458 memset(&msg_head, 0, sizeof(msg_head)); 459 msg_head.opcode = TX_EXPIRED; 460 msg_head.flags = op->flags; 461 msg_head.count = op->count; 462 msg_head.ival1 = op->ival1; 463 msg_head.ival2 = op->ival2; 464 msg_head.can_id = op->can_id; 465 msg_head.nframes = 0; 466 467 bcm_send_to_user(op, &msg_head, NULL, 0); 468 } 469 470 } else if (op->kt_ival2) { 471 bcm_can_tx(op); 472 } 473 474 return bcm_tx_set_expiry(op, &op->timer) ? 475 HRTIMER_RESTART : HRTIMER_NORESTART; 476 } 477 478 /* 479 * bcm_rx_changed - create a RX_CHANGED notification due to changed content 480 */ 481 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) 482 { 483 struct bcm_msg_head head; 484 485 /* update statistics */ 486 op->frames_filtered++; 487 488 /* prevent statistics overflow */ 489 if (op->frames_filtered > ULONG_MAX/100) 490 op->frames_filtered = op->frames_abs = 0; 491 492 /* this element is not throttled anymore */ 493 data->flags &= ~RX_THR; 494 495 memset(&head, 0, sizeof(head)); 496 head.opcode = RX_CHANGED; 497 head.flags = op->flags; 498 head.count = op->count; 499 head.ival1 = op->ival1; 500 head.ival2 = op->ival2; 501 head.can_id = op->can_id; 502 head.nframes = 1; 503 504 bcm_send_to_user(op, &head, data, 1); 505 } 506 507 /* 508 * bcm_rx_update_and_send - process a detected relevant receive content change 509 * 1. update the last received data 510 * 2. send a notification to the user (if possible) 511 */ 512 static void bcm_rx_update_and_send(struct bcm_op *op, 513 struct canfd_frame *lastdata, 514 const struct canfd_frame *rxdata, 515 unsigned char traffic_flags) 516 { 517 memcpy(lastdata, rxdata, op->cfsiz); 518 519 /* mark as used and throttled by default */ 520 lastdata->flags |= (RX_RECV|RX_THR); 521 522 /* add own/local/remote traffic flags */ 523 lastdata->flags |= traffic_flags; 524 525 /* throttling mode inactive ? */ 526 if (!op->kt_ival2) { 527 /* send RX_CHANGED to the user immediately */ 528 bcm_rx_changed(op, lastdata); 529 return; 530 } 531 532 /* with active throttling timer we are just done here */ 533 if (hrtimer_active(&op->thrtimer)) 534 return; 535 536 /* first reception with enabled throttling mode */ 537 if (!op->kt_lastmsg) 538 goto rx_changed_settime; 539 540 /* got a second frame inside a potential throttle period? */ 541 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) < 542 ktime_to_us(op->kt_ival2)) { 543 /* do not send the saved data - only start throttle timer */ 544 hrtimer_start(&op->thrtimer, 545 ktime_add(op->kt_lastmsg, op->kt_ival2), 546 HRTIMER_MODE_ABS_SOFT); 547 return; 548 } 549 550 /* the gap was that big, that throttling was not needed here */ 551 rx_changed_settime: 552 bcm_rx_changed(op, lastdata); 553 op->kt_lastmsg = ktime_get(); 554 } 555 556 /* 557 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly 558 * received data stored in op->last_frames[] 559 */ 560 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index, 561 const struct canfd_frame *rxdata, 562 unsigned char traffic_flags) 563 { 564 struct canfd_frame *cf = op->frames + op->cfsiz * index; 565 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 566 int i; 567 568 /* 569 * no one uses the MSBs of flags for comparison, 570 * so we use it here to detect the first time of reception 571 */ 572 573 if (!(lcf->flags & RX_RECV)) { 574 /* received data for the first time => send update to user */ 575 bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags); 576 return; 577 } 578 579 /* do a real check in CAN frame data section */ 580 for (i = 0; i < rxdata->len; i += 8) { 581 if ((get_u64(cf, i) & get_u64(rxdata, i)) != 582 (get_u64(cf, i) & get_u64(lcf, i))) { 583 bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags); 584 return; 585 } 586 } 587 588 if (op->flags & RX_CHECK_DLC) { 589 /* do a real check in CAN frame length */ 590 if (rxdata->len != lcf->len) { 591 bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags); 592 return; 593 } 594 } 595 } 596 597 /* 598 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception 599 */ 600 static void bcm_rx_starttimer(struct bcm_op *op) 601 { 602 if (op->flags & RX_NO_AUTOTIMER) 603 return; 604 605 if (op->kt_ival1) 606 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT); 607 } 608 609 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */ 610 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) 611 { 612 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); 613 struct bcm_msg_head msg_head; 614 615 /* if user wants to be informed, when cyclic CAN-Messages come back */ 616 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { 617 /* clear received CAN frames to indicate 'nothing received' */ 618 memset(op->last_frames, 0, op->nframes * op->cfsiz); 619 } 620 621 /* create notification to user */ 622 memset(&msg_head, 0, sizeof(msg_head)); 623 msg_head.opcode = RX_TIMEOUT; 624 msg_head.flags = op->flags; 625 msg_head.count = op->count; 626 msg_head.ival1 = op->ival1; 627 msg_head.ival2 = op->ival2; 628 msg_head.can_id = op->can_id; 629 msg_head.nframes = 0; 630 631 bcm_send_to_user(op, &msg_head, NULL, 0); 632 633 return HRTIMER_NORESTART; 634 } 635 636 /* 637 * bcm_rx_do_flush - helper for bcm_rx_thr_flush 638 */ 639 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index) 640 { 641 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; 642 643 if ((op->last_frames) && (lcf->flags & RX_THR)) { 644 bcm_rx_changed(op, lcf); 645 return 1; 646 } 647 return 0; 648 } 649 650 /* 651 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace 652 */ 653 static int bcm_rx_thr_flush(struct bcm_op *op) 654 { 655 int updated = 0; 656 657 if (op->nframes > 1) { 658 unsigned int i; 659 660 /* for MUX filter we start at index 1 */ 661 for (i = 1; i < op->nframes; i++) 662 updated += bcm_rx_do_flush(op, i); 663 664 } else { 665 /* for RX_FILTER_ID and simple filter */ 666 updated += bcm_rx_do_flush(op, 0); 667 } 668 669 return updated; 670 } 671 672 /* 673 * bcm_rx_thr_handler - the time for blocked content updates is over now: 674 * Check for throttled data and send it to the userspace 675 */ 676 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer) 677 { 678 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); 679 680 if (bcm_rx_thr_flush(op)) { 681 hrtimer_forward_now(hrtimer, op->kt_ival2); 682 return HRTIMER_RESTART; 683 } else { 684 /* rearm throttle handling */ 685 op->kt_lastmsg = 0; 686 return HRTIMER_NORESTART; 687 } 688 } 689 690 /* 691 * bcm_rx_handler - handle a CAN frame reception 692 */ 693 static void bcm_rx_handler(struct sk_buff *skb, void *data) 694 { 695 struct bcm_op *op = (struct bcm_op *)data; 696 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data; 697 unsigned int i; 698 unsigned char traffic_flags; 699 700 if (op->can_id != rxframe->can_id) 701 return; 702 703 /* make sure to handle the correct frame type (CAN / CAN FD) */ 704 if (op->flags & CAN_FD_FRAME) { 705 if (!can_is_canfd_skb(skb)) 706 return; 707 } else { 708 if (!can_is_can_skb(skb)) 709 return; 710 } 711 712 /* disable timeout */ 713 hrtimer_cancel(&op->timer); 714 715 /* save rx timestamp */ 716 op->rx_stamp = skb->tstamp; 717 /* save originator for recvfrom() */ 718 op->rx_ifindex = skb->dev->ifindex; 719 /* update statistics */ 720 op->frames_abs++; 721 722 if (op->flags & RX_RTR_FRAME) { 723 /* send reply for RTR-request (placed in op->frames[0]) */ 724 bcm_can_tx(op); 725 return; 726 } 727 728 /* compute flags to distinguish between own/local/remote CAN traffic */ 729 traffic_flags = 0; 730 if (skb->sk) { 731 traffic_flags |= RX_LOCAL; 732 if (skb->sk == op->sk) 733 traffic_flags |= RX_OWN; 734 } 735 736 if (op->flags & RX_FILTER_ID) { 737 /* the easiest case */ 738 bcm_rx_update_and_send(op, op->last_frames, rxframe, 739 traffic_flags); 740 goto rx_starttimer; 741 } 742 743 if (op->nframes == 1) { 744 /* simple compare with index 0 */ 745 bcm_rx_cmp_to_index(op, 0, rxframe, traffic_flags); 746 goto rx_starttimer; 747 } 748 749 if (op->nframes > 1) { 750 /* 751 * multiplex compare 752 * 753 * find the first multiplex mask that fits. 754 * Remark: The MUX-mask is stored in index 0 - but only the 755 * first 64 bits of the frame data[] are relevant (CAN FD) 756 */ 757 758 for (i = 1; i < op->nframes; i++) { 759 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) == 760 (get_u64(op->frames, 0) & 761 get_u64(op->frames + op->cfsiz * i, 0))) { 762 bcm_rx_cmp_to_index(op, i, rxframe, 763 traffic_flags); 764 break; 765 } 766 } 767 } 768 769 rx_starttimer: 770 bcm_rx_starttimer(op); 771 } 772 773 /* 774 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements 775 */ 776 static struct bcm_op *bcm_find_op(struct list_head *ops, 777 struct bcm_msg_head *mh, int ifindex) 778 { 779 struct bcm_op *op; 780 781 list_for_each_entry(op, ops, list) { 782 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 783 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) 784 return op; 785 } 786 787 return NULL; 788 } 789 790 static void bcm_free_op_rcu(struct rcu_head *rcu_head) 791 { 792 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu); 793 794 if ((op->frames) && (op->frames != &op->sframe)) 795 kfree(op->frames); 796 797 if ((op->last_frames) && (op->last_frames != &op->last_sframe)) 798 kfree(op->last_frames); 799 800 kfree(op); 801 } 802 803 static void bcm_remove_op(struct bcm_op *op) 804 { 805 hrtimer_cancel(&op->timer); 806 hrtimer_cancel(&op->thrtimer); 807 808 call_rcu(&op->rcu, bcm_free_op_rcu); 809 } 810 811 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op) 812 { 813 if (op->rx_reg_dev == dev) { 814 can_rx_unregister(dev_net(dev), dev, op->can_id, 815 REGMASK(op->can_id), bcm_rx_handler, op); 816 817 /* mark as removed subscription */ 818 op->rx_reg_dev = NULL; 819 } else 820 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device " 821 "mismatch %p %p\n", op->rx_reg_dev, dev); 822 } 823 824 /* 825 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops) 826 */ 827 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh, 828 int ifindex) 829 { 830 struct bcm_op *op, *n; 831 832 list_for_each_entry_safe(op, n, ops, list) { 833 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 834 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 835 836 /* disable automatic timer on frame reception */ 837 op->flags |= RX_NO_AUTOTIMER; 838 839 /* 840 * Don't care if we're bound or not (due to netdev 841 * problems) can_rx_unregister() is always a save 842 * thing to do here. 843 */ 844 if (op->ifindex) { 845 /* 846 * Only remove subscriptions that had not 847 * been removed due to NETDEV_UNREGISTER 848 * in bcm_notifier() 849 */ 850 if (op->rx_reg_dev) { 851 struct net_device *dev; 852 853 dev = dev_get_by_index(sock_net(op->sk), 854 op->ifindex); 855 if (dev) { 856 bcm_rx_unreg(dev, op); 857 dev_put(dev); 858 } 859 } 860 } else 861 can_rx_unregister(sock_net(op->sk), NULL, 862 op->can_id, 863 REGMASK(op->can_id), 864 bcm_rx_handler, op); 865 866 list_del_rcu(&op->list); 867 bcm_remove_op(op); 868 return 1; /* done */ 869 } 870 } 871 872 return 0; /* not found */ 873 } 874 875 /* 876 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops) 877 */ 878 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh, 879 int ifindex) 880 { 881 struct bcm_op *op, *n; 882 883 list_for_each_entry_safe(op, n, ops, list) { 884 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) && 885 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) { 886 list_del_rcu(&op->list); 887 bcm_remove_op(op); 888 return 1; /* done */ 889 } 890 } 891 892 return 0; /* not found */ 893 } 894 895 /* 896 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg) 897 */ 898 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head, 899 int ifindex) 900 { 901 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex); 902 903 if (!op) 904 return -EINVAL; 905 906 /* put current values into msg_head */ 907 msg_head->flags = op->flags; 908 msg_head->count = op->count; 909 msg_head->ival1 = op->ival1; 910 msg_head->ival2 = op->ival2; 911 msg_head->nframes = op->nframes; 912 913 bcm_send_to_user(op, msg_head, op->frames, 0); 914 915 return MHSIZ; 916 } 917 918 /* 919 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg) 920 */ 921 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 922 int ifindex, struct sock *sk) 923 { 924 struct bcm_sock *bo = bcm_sk(sk); 925 struct bcm_op *op; 926 struct canfd_frame *cf; 927 unsigned int i; 928 int err; 929 930 /* we need a real device to send frames */ 931 if (!ifindex) 932 return -ENODEV; 933 934 /* check nframes boundaries - we need at least one CAN frame */ 935 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES) 936 return -EINVAL; 937 938 /* check timeval limitations */ 939 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 940 return -EINVAL; 941 942 /* check the given can_id */ 943 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex); 944 if (op) { 945 /* update existing BCM operation */ 946 947 /* 948 * Do we need more space for the CAN frames than currently 949 * allocated? -> This is a _really_ unusual use-case and 950 * therefore (complexity / locking) it is not supported. 951 */ 952 if (msg_head->nframes > op->nframes) 953 return -E2BIG; 954 955 /* update CAN frames content */ 956 for (i = 0; i < msg_head->nframes; i++) { 957 958 cf = op->frames + op->cfsiz * i; 959 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 960 961 if (op->flags & CAN_FD_FRAME) { 962 if (cf->len > 64) 963 err = -EINVAL; 964 } else { 965 if (cf->len > 8) 966 err = -EINVAL; 967 } 968 969 if (err < 0) 970 return err; 971 972 if (msg_head->flags & TX_CP_CAN_ID) { 973 /* copy can_id into frame */ 974 cf->can_id = msg_head->can_id; 975 } 976 } 977 op->flags = msg_head->flags; 978 979 /* only lock for unlikely count/nframes/currframe changes */ 980 if (op->nframes != msg_head->nframes || 981 op->flags & TX_RESET_MULTI_IDX || 982 op->flags & SETTIMER) { 983 984 spin_lock_bh(&op->bcm_tx_lock); 985 986 if (op->nframes != msg_head->nframes || 987 op->flags & TX_RESET_MULTI_IDX) { 988 /* potentially update changed nframes */ 989 op->nframes = msg_head->nframes; 990 /* restart multiple frame transmission */ 991 op->currframe = 0; 992 } 993 994 if (op->flags & SETTIMER) 995 op->count = msg_head->count; 996 997 spin_unlock_bh(&op->bcm_tx_lock); 998 } 999 1000 } else { 1001 /* insert new BCM operation for the given can_id */ 1002 1003 op = kzalloc(OPSIZ, GFP_KERNEL); 1004 if (!op) 1005 return -ENOMEM; 1006 1007 spin_lock_init(&op->bcm_tx_lock); 1008 op->can_id = msg_head->can_id; 1009 op->cfsiz = CFSIZ(msg_head->flags); 1010 op->flags = msg_head->flags; 1011 op->nframes = msg_head->nframes; 1012 1013 if (op->flags & SETTIMER) 1014 op->count = msg_head->count; 1015 1016 /* create array for CAN frames and copy the data */ 1017 if (msg_head->nframes > 1) { 1018 op->frames = kmalloc_array(msg_head->nframes, 1019 op->cfsiz, 1020 GFP_KERNEL); 1021 if (!op->frames) { 1022 kfree(op); 1023 return -ENOMEM; 1024 } 1025 } else 1026 op->frames = &op->sframe; 1027 1028 for (i = 0; i < msg_head->nframes; i++) { 1029 1030 cf = op->frames + op->cfsiz * i; 1031 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz); 1032 if (err < 0) 1033 goto free_op; 1034 1035 if (op->flags & CAN_FD_FRAME) { 1036 if (cf->len > 64) 1037 err = -EINVAL; 1038 } else { 1039 if (cf->len > 8) 1040 err = -EINVAL; 1041 } 1042 1043 if (err < 0) 1044 goto free_op; 1045 1046 if (msg_head->flags & TX_CP_CAN_ID) { 1047 /* copy can_id into frame */ 1048 cf->can_id = msg_head->can_id; 1049 } 1050 } 1051 1052 /* tx_ops never compare with previous received messages */ 1053 op->last_frames = NULL; 1054 1055 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1056 op->sk = sk; 1057 op->ifindex = ifindex; 1058 1059 /* initialize uninitialized (kzalloc) structure */ 1060 hrtimer_setup(&op->timer, bcm_tx_timeout_handler, CLOCK_MONOTONIC, 1061 HRTIMER_MODE_REL_SOFT); 1062 1063 /* currently unused in tx_ops */ 1064 hrtimer_setup(&op->thrtimer, hrtimer_dummy_timeout, CLOCK_MONOTONIC, 1065 HRTIMER_MODE_REL_SOFT); 1066 1067 /* add this bcm_op to the list of the tx_ops */ 1068 list_add(&op->list, &bo->tx_ops); 1069 1070 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */ 1071 1072 if (op->flags & SETTIMER) { 1073 /* set timer values */ 1074 op->ival1 = msg_head->ival1; 1075 op->ival2 = msg_head->ival2; 1076 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1077 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1078 1079 /* disable an active timer due to zero values? */ 1080 if (!op->kt_ival1 && !op->kt_ival2) 1081 hrtimer_cancel(&op->timer); 1082 } 1083 1084 if (op->flags & STARTTIMER) { 1085 hrtimer_cancel(&op->timer); 1086 /* spec: send CAN frame when starting timer */ 1087 op->flags |= TX_ANNOUNCE; 1088 } 1089 1090 if (op->flags & TX_ANNOUNCE) 1091 bcm_can_tx(op); 1092 1093 if (op->flags & STARTTIMER) 1094 bcm_tx_start_timer(op); 1095 1096 return msg_head->nframes * op->cfsiz + MHSIZ; 1097 1098 free_op: 1099 if (op->frames != &op->sframe) 1100 kfree(op->frames); 1101 kfree(op); 1102 return err; 1103 } 1104 1105 /* 1106 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg) 1107 */ 1108 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, 1109 int ifindex, struct sock *sk) 1110 { 1111 struct bcm_sock *bo = bcm_sk(sk); 1112 struct bcm_op *op; 1113 int do_rx_register; 1114 int err = 0; 1115 1116 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) { 1117 /* be robust against wrong usage ... */ 1118 msg_head->flags |= RX_FILTER_ID; 1119 /* ignore trailing garbage */ 1120 msg_head->nframes = 0; 1121 } 1122 1123 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */ 1124 if (msg_head->nframes > MAX_NFRAMES + 1) 1125 return -EINVAL; 1126 1127 if ((msg_head->flags & RX_RTR_FRAME) && 1128 ((msg_head->nframes != 1) || 1129 (!(msg_head->can_id & CAN_RTR_FLAG)))) 1130 return -EINVAL; 1131 1132 /* check timeval limitations */ 1133 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head)) 1134 return -EINVAL; 1135 1136 /* check the given can_id */ 1137 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex); 1138 if (op) { 1139 /* update existing BCM operation */ 1140 1141 /* 1142 * Do we need more space for the CAN frames than currently 1143 * allocated? -> This is a _really_ unusual use-case and 1144 * therefore (complexity / locking) it is not supported. 1145 */ 1146 if (msg_head->nframes > op->nframes) 1147 return -E2BIG; 1148 1149 if (msg_head->nframes) { 1150 /* update CAN frames content */ 1151 err = memcpy_from_msg(op->frames, msg, 1152 msg_head->nframes * op->cfsiz); 1153 if (err < 0) 1154 return err; 1155 1156 /* clear last_frames to indicate 'nothing received' */ 1157 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz); 1158 } 1159 1160 op->nframes = msg_head->nframes; 1161 op->flags = msg_head->flags; 1162 1163 /* Only an update -> do not call can_rx_register() */ 1164 do_rx_register = 0; 1165 1166 } else { 1167 /* insert new BCM operation for the given can_id */ 1168 op = kzalloc(OPSIZ, GFP_KERNEL); 1169 if (!op) 1170 return -ENOMEM; 1171 1172 op->can_id = msg_head->can_id; 1173 op->nframes = msg_head->nframes; 1174 op->cfsiz = CFSIZ(msg_head->flags); 1175 op->flags = msg_head->flags; 1176 1177 if (msg_head->nframes > 1) { 1178 /* create array for CAN frames and copy the data */ 1179 op->frames = kmalloc_array(msg_head->nframes, 1180 op->cfsiz, 1181 GFP_KERNEL); 1182 if (!op->frames) { 1183 kfree(op); 1184 return -ENOMEM; 1185 } 1186 1187 /* create and init array for received CAN frames */ 1188 op->last_frames = kcalloc(msg_head->nframes, 1189 op->cfsiz, 1190 GFP_KERNEL); 1191 if (!op->last_frames) { 1192 kfree(op->frames); 1193 kfree(op); 1194 return -ENOMEM; 1195 } 1196 1197 } else { 1198 op->frames = &op->sframe; 1199 op->last_frames = &op->last_sframe; 1200 } 1201 1202 if (msg_head->nframes) { 1203 err = memcpy_from_msg(op->frames, msg, 1204 msg_head->nframes * op->cfsiz); 1205 if (err < 0) { 1206 if (op->frames != &op->sframe) 1207 kfree(op->frames); 1208 if (op->last_frames != &op->last_sframe) 1209 kfree(op->last_frames); 1210 kfree(op); 1211 return err; 1212 } 1213 } 1214 1215 /* bcm_can_tx / bcm_tx_timeout_handler needs this */ 1216 op->sk = sk; 1217 op->ifindex = ifindex; 1218 1219 /* ifindex for timeout events w/o previous frame reception */ 1220 op->rx_ifindex = ifindex; 1221 1222 /* initialize uninitialized (kzalloc) structure */ 1223 hrtimer_setup(&op->timer, bcm_rx_timeout_handler, CLOCK_MONOTONIC, 1224 HRTIMER_MODE_REL_SOFT); 1225 hrtimer_setup(&op->thrtimer, bcm_rx_thr_handler, CLOCK_MONOTONIC, 1226 HRTIMER_MODE_REL_SOFT); 1227 1228 /* add this bcm_op to the list of the rx_ops */ 1229 list_add(&op->list, &bo->rx_ops); 1230 1231 /* call can_rx_register() */ 1232 do_rx_register = 1; 1233 1234 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */ 1235 1236 /* check flags */ 1237 1238 if (op->flags & RX_RTR_FRAME) { 1239 struct canfd_frame *frame0 = op->frames; 1240 1241 /* no timers in RTR-mode */ 1242 hrtimer_cancel(&op->thrtimer); 1243 hrtimer_cancel(&op->timer); 1244 1245 /* 1246 * funny feature in RX(!)_SETUP only for RTR-mode: 1247 * copy can_id into frame BUT without RTR-flag to 1248 * prevent a full-load-loopback-test ... ;-] 1249 */ 1250 if ((op->flags & TX_CP_CAN_ID) || 1251 (frame0->can_id == op->can_id)) 1252 frame0->can_id = op->can_id & ~CAN_RTR_FLAG; 1253 1254 } else { 1255 if (op->flags & SETTIMER) { 1256 1257 /* set timer value */ 1258 op->ival1 = msg_head->ival1; 1259 op->ival2 = msg_head->ival2; 1260 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1); 1261 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2); 1262 1263 /* disable an active timer due to zero value? */ 1264 if (!op->kt_ival1) 1265 hrtimer_cancel(&op->timer); 1266 1267 /* 1268 * In any case cancel the throttle timer, flush 1269 * potentially blocked msgs and reset throttle handling 1270 */ 1271 op->kt_lastmsg = 0; 1272 hrtimer_cancel(&op->thrtimer); 1273 bcm_rx_thr_flush(op); 1274 } 1275 1276 if ((op->flags & STARTTIMER) && op->kt_ival1) 1277 hrtimer_start(&op->timer, op->kt_ival1, 1278 HRTIMER_MODE_REL_SOFT); 1279 } 1280 1281 /* now we can register for can_ids, if we added a new bcm_op */ 1282 if (do_rx_register) { 1283 if (ifindex) { 1284 struct net_device *dev; 1285 1286 dev = dev_get_by_index(sock_net(sk), ifindex); 1287 if (dev) { 1288 err = can_rx_register(sock_net(sk), dev, 1289 op->can_id, 1290 REGMASK(op->can_id), 1291 bcm_rx_handler, op, 1292 "bcm", sk); 1293 1294 op->rx_reg_dev = dev; 1295 dev_put(dev); 1296 } 1297 1298 } else 1299 err = can_rx_register(sock_net(sk), NULL, op->can_id, 1300 REGMASK(op->can_id), 1301 bcm_rx_handler, op, "bcm", sk); 1302 if (err) { 1303 /* this bcm rx op is broken -> remove it */ 1304 list_del_rcu(&op->list); 1305 bcm_remove_op(op); 1306 return err; 1307 } 1308 } 1309 1310 return msg_head->nframes * op->cfsiz + MHSIZ; 1311 } 1312 1313 /* 1314 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg) 1315 */ 1316 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk, 1317 int cfsiz) 1318 { 1319 struct sk_buff *skb; 1320 struct net_device *dev; 1321 int err; 1322 1323 /* we need a real device to send frames */ 1324 if (!ifindex) 1325 return -ENODEV; 1326 1327 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL); 1328 if (!skb) 1329 return -ENOMEM; 1330 1331 can_skb_reserve(skb); 1332 1333 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz); 1334 if (err < 0) { 1335 kfree_skb(skb); 1336 return err; 1337 } 1338 1339 dev = dev_get_by_index(sock_net(sk), ifindex); 1340 if (!dev) { 1341 kfree_skb(skb); 1342 return -ENODEV; 1343 } 1344 1345 can_skb_prv(skb)->ifindex = dev->ifindex; 1346 can_skb_prv(skb)->skbcnt = 0; 1347 skb->dev = dev; 1348 can_skb_set_owner(skb, sk); 1349 err = can_send(skb, 1); /* send with loopback */ 1350 dev_put(dev); 1351 1352 if (err) 1353 return err; 1354 1355 return cfsiz + MHSIZ; 1356 } 1357 1358 /* 1359 * bcm_sendmsg - process BCM commands (opcodes) from the userspace 1360 */ 1361 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 1362 { 1363 struct sock *sk = sock->sk; 1364 struct bcm_sock *bo = bcm_sk(sk); 1365 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */ 1366 struct bcm_msg_head msg_head; 1367 int cfsiz; 1368 int ret; /* read bytes or error codes as return value */ 1369 1370 if (!bo->bound) 1371 return -ENOTCONN; 1372 1373 /* check for valid message length from userspace */ 1374 if (size < MHSIZ) 1375 return -EINVAL; 1376 1377 /* read message head information */ 1378 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ); 1379 if (ret < 0) 1380 return ret; 1381 1382 cfsiz = CFSIZ(msg_head.flags); 1383 if ((size - MHSIZ) % cfsiz) 1384 return -EINVAL; 1385 1386 /* check for alternative ifindex for this bcm_op */ 1387 1388 if (!ifindex && msg->msg_name) { 1389 /* no bound device as default => check msg_name */ 1390 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); 1391 1392 if (msg->msg_namelen < BCM_MIN_NAMELEN) 1393 return -EINVAL; 1394 1395 if (addr->can_family != AF_CAN) 1396 return -EINVAL; 1397 1398 /* ifindex from sendto() */ 1399 ifindex = addr->can_ifindex; 1400 1401 if (ifindex) { 1402 struct net_device *dev; 1403 1404 dev = dev_get_by_index(sock_net(sk), ifindex); 1405 if (!dev) 1406 return -ENODEV; 1407 1408 if (dev->type != ARPHRD_CAN) { 1409 dev_put(dev); 1410 return -ENODEV; 1411 } 1412 1413 dev_put(dev); 1414 } 1415 } 1416 1417 lock_sock(sk); 1418 1419 switch (msg_head.opcode) { 1420 1421 case TX_SETUP: 1422 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk); 1423 break; 1424 1425 case RX_SETUP: 1426 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk); 1427 break; 1428 1429 case TX_DELETE: 1430 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex)) 1431 ret = MHSIZ; 1432 else 1433 ret = -EINVAL; 1434 break; 1435 1436 case RX_DELETE: 1437 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex)) 1438 ret = MHSIZ; 1439 else 1440 ret = -EINVAL; 1441 break; 1442 1443 case TX_READ: 1444 /* reuse msg_head for the reply to TX_READ */ 1445 msg_head.opcode = TX_STATUS; 1446 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex); 1447 break; 1448 1449 case RX_READ: 1450 /* reuse msg_head for the reply to RX_READ */ 1451 msg_head.opcode = RX_STATUS; 1452 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex); 1453 break; 1454 1455 case TX_SEND: 1456 /* we need exactly one CAN frame behind the msg head */ 1457 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ)) 1458 ret = -EINVAL; 1459 else 1460 ret = bcm_tx_send(msg, ifindex, sk, cfsiz); 1461 break; 1462 1463 default: 1464 ret = -EINVAL; 1465 break; 1466 } 1467 1468 release_sock(sk); 1469 1470 return ret; 1471 } 1472 1473 /* 1474 * notification handler for netdevice status changes 1475 */ 1476 static void bcm_notify(struct bcm_sock *bo, unsigned long msg, 1477 struct net_device *dev) 1478 { 1479 struct sock *sk = &bo->sk; 1480 struct bcm_op *op; 1481 int notify_enodev = 0; 1482 1483 if (!net_eq(dev_net(dev), sock_net(sk))) 1484 return; 1485 1486 switch (msg) { 1487 1488 case NETDEV_UNREGISTER: 1489 lock_sock(sk); 1490 1491 /* remove device specific receive entries */ 1492 list_for_each_entry(op, &bo->rx_ops, list) 1493 if (op->rx_reg_dev == dev) 1494 bcm_rx_unreg(dev, op); 1495 1496 /* remove device reference, if this is our bound device */ 1497 if (bo->bound && bo->ifindex == dev->ifindex) { 1498 #if IS_ENABLED(CONFIG_PROC_FS) 1499 if (sock_net(sk)->can.bcmproc_dir && bo->bcm_proc_read) { 1500 remove_proc_entry(bo->procname, sock_net(sk)->can.bcmproc_dir); 1501 bo->bcm_proc_read = NULL; 1502 } 1503 #endif 1504 bo->bound = 0; 1505 bo->ifindex = 0; 1506 notify_enodev = 1; 1507 } 1508 1509 release_sock(sk); 1510 1511 if (notify_enodev) { 1512 sk->sk_err = ENODEV; 1513 if (!sock_flag(sk, SOCK_DEAD)) 1514 sk_error_report(sk); 1515 } 1516 break; 1517 1518 case NETDEV_DOWN: 1519 if (bo->bound && bo->ifindex == dev->ifindex) { 1520 sk->sk_err = ENETDOWN; 1521 if (!sock_flag(sk, SOCK_DEAD)) 1522 sk_error_report(sk); 1523 } 1524 } 1525 } 1526 1527 static int bcm_notifier(struct notifier_block *nb, unsigned long msg, 1528 void *ptr) 1529 { 1530 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1531 1532 if (dev->type != ARPHRD_CAN) 1533 return NOTIFY_DONE; 1534 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN) 1535 return NOTIFY_DONE; 1536 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */ 1537 return NOTIFY_DONE; 1538 1539 spin_lock(&bcm_notifier_lock); 1540 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) { 1541 spin_unlock(&bcm_notifier_lock); 1542 bcm_notify(bcm_busy_notifier, msg, dev); 1543 spin_lock(&bcm_notifier_lock); 1544 } 1545 bcm_busy_notifier = NULL; 1546 spin_unlock(&bcm_notifier_lock); 1547 return NOTIFY_DONE; 1548 } 1549 1550 /* 1551 * initial settings for all BCM sockets to be set at socket creation time 1552 */ 1553 static int bcm_init(struct sock *sk) 1554 { 1555 struct bcm_sock *bo = bcm_sk(sk); 1556 1557 bo->bound = 0; 1558 bo->ifindex = 0; 1559 bo->dropped_usr_msgs = 0; 1560 bo->bcm_proc_read = NULL; 1561 1562 INIT_LIST_HEAD(&bo->tx_ops); 1563 INIT_LIST_HEAD(&bo->rx_ops); 1564 1565 /* set notifier */ 1566 spin_lock(&bcm_notifier_lock); 1567 list_add_tail(&bo->notifier, &bcm_notifier_list); 1568 spin_unlock(&bcm_notifier_lock); 1569 1570 return 0; 1571 } 1572 1573 /* 1574 * standard socket functions 1575 */ 1576 static int bcm_release(struct socket *sock) 1577 { 1578 struct sock *sk = sock->sk; 1579 struct net *net; 1580 struct bcm_sock *bo; 1581 struct bcm_op *op, *next; 1582 1583 if (!sk) 1584 return 0; 1585 1586 net = sock_net(sk); 1587 bo = bcm_sk(sk); 1588 1589 /* remove bcm_ops, timer, rx_unregister(), etc. */ 1590 1591 spin_lock(&bcm_notifier_lock); 1592 while (bcm_busy_notifier == bo) { 1593 spin_unlock(&bcm_notifier_lock); 1594 schedule_timeout_uninterruptible(1); 1595 spin_lock(&bcm_notifier_lock); 1596 } 1597 list_del(&bo->notifier); 1598 spin_unlock(&bcm_notifier_lock); 1599 1600 lock_sock(sk); 1601 1602 #if IS_ENABLED(CONFIG_PROC_FS) 1603 /* remove procfs entry */ 1604 if (net->can.bcmproc_dir && bo->bcm_proc_read) 1605 remove_proc_entry(bo->procname, net->can.bcmproc_dir); 1606 #endif /* CONFIG_PROC_FS */ 1607 1608 list_for_each_entry_safe(op, next, &bo->tx_ops, list) 1609 bcm_remove_op(op); 1610 1611 list_for_each_entry_safe(op, next, &bo->rx_ops, list) { 1612 /* 1613 * Don't care if we're bound or not (due to netdev problems) 1614 * can_rx_unregister() is always a save thing to do here. 1615 */ 1616 if (op->ifindex) { 1617 /* 1618 * Only remove subscriptions that had not 1619 * been removed due to NETDEV_UNREGISTER 1620 * in bcm_notifier() 1621 */ 1622 if (op->rx_reg_dev) { 1623 struct net_device *dev; 1624 1625 dev = dev_get_by_index(net, op->ifindex); 1626 if (dev) { 1627 bcm_rx_unreg(dev, op); 1628 dev_put(dev); 1629 } 1630 } 1631 } else 1632 can_rx_unregister(net, NULL, op->can_id, 1633 REGMASK(op->can_id), 1634 bcm_rx_handler, op); 1635 1636 } 1637 1638 synchronize_rcu(); 1639 1640 list_for_each_entry_safe(op, next, &bo->rx_ops, list) 1641 bcm_remove_op(op); 1642 1643 /* remove device reference */ 1644 if (bo->bound) { 1645 bo->bound = 0; 1646 bo->ifindex = 0; 1647 } 1648 1649 sock_orphan(sk); 1650 sock->sk = NULL; 1651 1652 release_sock(sk); 1653 sock_prot_inuse_add(net, sk->sk_prot, -1); 1654 sock_put(sk); 1655 1656 return 0; 1657 } 1658 1659 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, 1660 int flags) 1661 { 1662 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; 1663 struct sock *sk = sock->sk; 1664 struct bcm_sock *bo = bcm_sk(sk); 1665 struct net *net = sock_net(sk); 1666 int ret = 0; 1667 1668 if (len < BCM_MIN_NAMELEN) 1669 return -EINVAL; 1670 1671 lock_sock(sk); 1672 1673 if (bo->bound) { 1674 ret = -EISCONN; 1675 goto fail; 1676 } 1677 1678 /* bind a device to this socket */ 1679 if (addr->can_ifindex) { 1680 struct net_device *dev; 1681 1682 dev = dev_get_by_index(net, addr->can_ifindex); 1683 if (!dev) { 1684 ret = -ENODEV; 1685 goto fail; 1686 } 1687 if (dev->type != ARPHRD_CAN) { 1688 dev_put(dev); 1689 ret = -ENODEV; 1690 goto fail; 1691 } 1692 1693 bo->ifindex = dev->ifindex; 1694 dev_put(dev); 1695 1696 } else { 1697 /* no interface reference for ifindex = 0 ('any' CAN device) */ 1698 bo->ifindex = 0; 1699 } 1700 1701 #if IS_ENABLED(CONFIG_PROC_FS) 1702 if (net->can.bcmproc_dir) { 1703 /* unique socket address as filename */ 1704 sprintf(bo->procname, "%lu", sock_i_ino(sk)); 1705 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644, 1706 net->can.bcmproc_dir, 1707 bcm_proc_show, sk); 1708 if (!bo->bcm_proc_read) { 1709 ret = -ENOMEM; 1710 goto fail; 1711 } 1712 } 1713 #endif /* CONFIG_PROC_FS */ 1714 1715 bo->bound = 1; 1716 1717 fail: 1718 release_sock(sk); 1719 1720 return ret; 1721 } 1722 1723 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1724 int flags) 1725 { 1726 struct sock *sk = sock->sk; 1727 struct sk_buff *skb; 1728 int error = 0; 1729 int err; 1730 1731 skb = skb_recv_datagram(sk, flags, &error); 1732 if (!skb) 1733 return error; 1734 1735 if (skb->len < size) 1736 size = skb->len; 1737 1738 err = memcpy_to_msg(msg, skb->data, size); 1739 if (err < 0) { 1740 skb_free_datagram(sk, skb); 1741 return err; 1742 } 1743 1744 sock_recv_cmsgs(msg, sk, skb); 1745 1746 if (msg->msg_name) { 1747 __sockaddr_check_size(BCM_MIN_NAMELEN); 1748 msg->msg_namelen = BCM_MIN_NAMELEN; 1749 memcpy(msg->msg_name, skb->cb, msg->msg_namelen); 1750 } 1751 1752 /* assign the flags that have been recorded in bcm_send_to_user() */ 1753 msg->msg_flags |= *(bcm_flags(skb)); 1754 1755 skb_free_datagram(sk, skb); 1756 1757 return size; 1758 } 1759 1760 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd, 1761 unsigned long arg) 1762 { 1763 /* no ioctls for socket layer -> hand it down to NIC layer */ 1764 return -ENOIOCTLCMD; 1765 } 1766 1767 static const struct proto_ops bcm_ops = { 1768 .family = PF_CAN, 1769 .release = bcm_release, 1770 .bind = sock_no_bind, 1771 .connect = bcm_connect, 1772 .socketpair = sock_no_socketpair, 1773 .accept = sock_no_accept, 1774 .getname = sock_no_getname, 1775 .poll = datagram_poll, 1776 .ioctl = bcm_sock_no_ioctlcmd, 1777 .gettstamp = sock_gettstamp, 1778 .listen = sock_no_listen, 1779 .shutdown = sock_no_shutdown, 1780 .sendmsg = bcm_sendmsg, 1781 .recvmsg = bcm_recvmsg, 1782 .mmap = sock_no_mmap, 1783 }; 1784 1785 static struct proto bcm_proto __read_mostly = { 1786 .name = "CAN_BCM", 1787 .owner = THIS_MODULE, 1788 .obj_size = sizeof(struct bcm_sock), 1789 .init = bcm_init, 1790 }; 1791 1792 static const struct can_proto bcm_can_proto = { 1793 .type = SOCK_DGRAM, 1794 .protocol = CAN_BCM, 1795 .ops = &bcm_ops, 1796 .prot = &bcm_proto, 1797 }; 1798 1799 static int canbcm_pernet_init(struct net *net) 1800 { 1801 #if IS_ENABLED(CONFIG_PROC_FS) 1802 /* create /proc/net/can-bcm directory */ 1803 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net); 1804 #endif /* CONFIG_PROC_FS */ 1805 1806 return 0; 1807 } 1808 1809 static void canbcm_pernet_exit(struct net *net) 1810 { 1811 #if IS_ENABLED(CONFIG_PROC_FS) 1812 /* remove /proc/net/can-bcm directory */ 1813 if (net->can.bcmproc_dir) 1814 remove_proc_entry("can-bcm", net->proc_net); 1815 #endif /* CONFIG_PROC_FS */ 1816 } 1817 1818 static struct pernet_operations canbcm_pernet_ops __read_mostly = { 1819 .init = canbcm_pernet_init, 1820 .exit = canbcm_pernet_exit, 1821 }; 1822 1823 static struct notifier_block canbcm_notifier = { 1824 .notifier_call = bcm_notifier 1825 }; 1826 1827 static int __init bcm_module_init(void) 1828 { 1829 int err; 1830 1831 pr_info("can: broadcast manager protocol\n"); 1832 1833 err = register_pernet_subsys(&canbcm_pernet_ops); 1834 if (err) 1835 return err; 1836 1837 err = register_netdevice_notifier(&canbcm_notifier); 1838 if (err) 1839 goto register_notifier_failed; 1840 1841 err = can_proto_register(&bcm_can_proto); 1842 if (err < 0) { 1843 printk(KERN_ERR "can: registration of bcm protocol failed\n"); 1844 goto register_proto_failed; 1845 } 1846 1847 return 0; 1848 1849 register_proto_failed: 1850 unregister_netdevice_notifier(&canbcm_notifier); 1851 register_notifier_failed: 1852 unregister_pernet_subsys(&canbcm_pernet_ops); 1853 return err; 1854 } 1855 1856 static void __exit bcm_module_exit(void) 1857 { 1858 can_proto_unregister(&bcm_can_proto); 1859 unregister_netdevice_notifier(&canbcm_notifier); 1860 unregister_pernet_subsys(&canbcm_pernet_ops); 1861 } 1862 1863 module_init(bcm_module_init); 1864 module_exit(bcm_module_exit); 1865