1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2/*
   3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
   4 *
   5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions
  10 * are met:
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the name of Volkswagen nor the names of its contributors
  17 *    may be used to endorse or promote products derived from this software
  18 *    without specific prior written permission.
  19 *
  20 * Alternatively, provided that this notice is retained in full, this
  21 * software may be distributed under the terms of the GNU General
  22 * Public License ("GPL") version 2, in which case the provisions of the
  23 * GPL apply INSTEAD OF those given above.
  24 *
  25 * The provided data structures and external interfaces from this code
  26 * are not restricted to be used by modules with a GPL compatible license.
  27 *
  28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  39 * DAMAGE.
  40 *
  41 */
  42
  43#include <linux/module.h>
  44#include <linux/init.h>
  45#include <linux/interrupt.h>
  46#include <linux/hrtimer.h>
  47#include <linux/list.h>
  48#include <linux/proc_fs.h>
  49#include <linux/seq_file.h>
  50#include <linux/uio.h>
  51#include <linux/net.h>
  52#include <linux/netdevice.h>
  53#include <linux/socket.h>
  54#include <linux/if_arp.h>
  55#include <linux/skbuff.h>
  56#include <linux/can.h>
  57#include <linux/can/core.h>
  58#include <linux/can/skb.h>
  59#include <linux/can/bcm.h>
  60#include <linux/slab.h>
  61#include <net/sock.h>
  62#include <net/net_namespace.h>
  63
  64/*
  65 * To send multiple CAN frame content within TX_SETUP or to filter
  66 * CAN messages with multiplex index within RX_SETUP, the number of
  67 * different filters is limited to 256 due to the one byte index value.
  68 */
  69#define MAX_NFRAMES 256
  70
  71/* limit timers to 400 days for sending/timeouts */
  72#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
  73
  74/* use of last_frames[index].flags */
  75#define RX_RECV    0x40 /* received data for this element */
  76#define RX_THR     0x80 /* element not been sent due to throttle feature */
  77#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
  78
  79/* get best masking value for can_rx_register() for a given single can_id */
  80#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
  81		     (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
  82		     (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
  83
  84MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
  85MODULE_LICENSE("Dual BSD/GPL");
  86MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
  87MODULE_ALIAS("can-proto-2");
  88
  89#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
  90
  91/*
  92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
  93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
  94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
  95 */
  96static inline u64 get_u64(const struct canfd_frame *cp, int offset)
  97{
  98	return *(u64 *)(cp->data + offset);
  99}
 100
 101struct bcm_op {
 102	struct list_head list;
 103	struct rcu_head rcu;
 104	int ifindex;
 105	canid_t can_id;
 106	u32 flags;
 107	unsigned long frames_abs, frames_filtered;
 108	struct bcm_timeval ival1, ival2;
 109	struct hrtimer timer, thrtimer;
 110	ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
 111	int rx_ifindex;
 112	int cfsiz;
 113	u32 count;
 114	u32 nframes;
 115	u32 currframe;
 116	/* void pointers to arrays of struct can[fd]_frame */
 117	void *frames;
 118	void *last_frames;
 119	struct canfd_frame sframe;
 120	struct canfd_frame last_sframe;
 121	struct sock *sk;
 122	struct net_device *rx_reg_dev;
 123};
 124
 125struct bcm_sock {
 126	struct sock sk;
 127	int bound;
 128	int ifindex;
 129	struct list_head notifier;
 130	struct list_head rx_ops;
 131	struct list_head tx_ops;
 132	unsigned long dropped_usr_msgs;
 133	struct proc_dir_entry *bcm_proc_read;
 134	char procname [32]; /* inode number in decimal with \0 */
 135};
 136
 137static LIST_HEAD(bcm_notifier_list);
 138static DEFINE_SPINLOCK(bcm_notifier_lock);
 139static struct bcm_sock *bcm_busy_notifier;
 140
 141static inline struct bcm_sock *bcm_sk(const struct sock *sk)
 142{
 143	return (struct bcm_sock *)sk;
 144}
 145
 146static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
 147{
 148	return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
 149}
 150
 151/* check limitations for timeval provided by user */
 152static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
 153{
 154	if ((msg_head->ival1.tv_sec < 0) ||
 155	    (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
 156	    (msg_head->ival1.tv_usec < 0) ||
 157	    (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
 158	    (msg_head->ival2.tv_sec < 0) ||
 159	    (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
 160	    (msg_head->ival2.tv_usec < 0) ||
 161	    (msg_head->ival2.tv_usec >= USEC_PER_SEC))
 162		return true;
 163
 164	return false;
 165}
 166
 167#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
 168#define OPSIZ sizeof(struct bcm_op)
 169#define MHSIZ sizeof(struct bcm_msg_head)
 170
 171/*
 172 * procfs functions
 173 */
 174#if IS_ENABLED(CONFIG_PROC_FS)
 175static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
 176{
 177	struct net_device *dev;
 178
 179	if (!ifindex)
 180		return "any";
 181
 182	rcu_read_lock();
 183	dev = dev_get_by_index_rcu(net, ifindex);
 184	if (dev)
 185		strcpy(result, dev->name);
 186	else
 187		strcpy(result, "???");
 188	rcu_read_unlock();
 189
 190	return result;
 191}
 192
 193static int bcm_proc_show(struct seq_file *m, void *v)
 194{
 195	char ifname[IFNAMSIZ];
 196	struct net *net = m->private;
 197	struct sock *sk = (struct sock *)pde_data(m->file->f_inode);
 198	struct bcm_sock *bo = bcm_sk(sk);
 199	struct bcm_op *op;
 200
 201	seq_printf(m, ">>> socket %pK", sk->sk_socket);
 202	seq_printf(m, " / sk %pK", sk);
 203	seq_printf(m, " / bo %pK", bo);
 204	seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
 205	seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
 206	seq_printf(m, " <<<\n");
 207
 208	list_for_each_entry(op, &bo->rx_ops, list) {
 209
 210		unsigned long reduction;
 211
 212		/* print only active entries & prevent division by zero */
 213		if (!op->frames_abs)
 214			continue;
 215
 216		seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
 217			   bcm_proc_getifname(net, ifname, op->ifindex));
 218
 219		if (op->flags & CAN_FD_FRAME)
 220			seq_printf(m, "(%u)", op->nframes);
 221		else
 222			seq_printf(m, "[%u]", op->nframes);
 223
 224		seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
 225
 226		if (op->kt_ival1)
 227			seq_printf(m, "timeo=%lld ",
 228				   (long long)ktime_to_us(op->kt_ival1));
 229
 230		if (op->kt_ival2)
 231			seq_printf(m, "thr=%lld ",
 232				   (long long)ktime_to_us(op->kt_ival2));
 233
 234		seq_printf(m, "# recv %ld (%ld) => reduction: ",
 235			   op->frames_filtered, op->frames_abs);
 236
 237		reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
 238
 239		seq_printf(m, "%s%ld%%\n",
 240			   (reduction == 100) ? "near " : "", reduction);
 241	}
 242
 243	list_for_each_entry(op, &bo->tx_ops, list) {
 244
 245		seq_printf(m, "tx_op: %03X %s ", op->can_id,
 246			   bcm_proc_getifname(net, ifname, op->ifindex));
 247
 248		if (op->flags & CAN_FD_FRAME)
 249			seq_printf(m, "(%u) ", op->nframes);
 250		else
 251			seq_printf(m, "[%u] ", op->nframes);
 252
 253		if (op->kt_ival1)
 254			seq_printf(m, "t1=%lld ",
 255				   (long long)ktime_to_us(op->kt_ival1));
 256
 257		if (op->kt_ival2)
 258			seq_printf(m, "t2=%lld ",
 259				   (long long)ktime_to_us(op->kt_ival2));
 260
 261		seq_printf(m, "# sent %ld\n", op->frames_abs);
 262	}
 263	seq_putc(m, '\n');
 264	return 0;
 265}
 266#endif /* CONFIG_PROC_FS */
 267
 268/*
 269 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
 270 *              of the given bcm tx op
 271 */
 272static void bcm_can_tx(struct bcm_op *op)
 273{
 274	struct sk_buff *skb;
 275	struct net_device *dev;
 276	struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
 277	int err;
 278
 279	/* no target device? => exit */
 280	if (!op->ifindex)
 281		return;
 282
 283	dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
 284	if (!dev) {
 285		/* RFC: should this bcm_op remove itself here? */
 286		return;
 287	}
 288
 289	skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
 290	if (!skb)
 291		goto out;
 292
 293	can_skb_reserve(skb);
 294	can_skb_prv(skb)->ifindex = dev->ifindex;
 295	can_skb_prv(skb)->skbcnt = 0;
 296
 297	skb_put_data(skb, cf, op->cfsiz);
 298
 299	/* send with loopback */
 300	skb->dev = dev;
 301	can_skb_set_owner(skb, op->sk);
 302	err = can_send(skb, 1);
 303	if (!err)
 304		op->frames_abs++;
 305
 306	op->currframe++;
 307
 308	/* reached last frame? */
 309	if (op->currframe >= op->nframes)
 310		op->currframe = 0;
 311out:
 312	dev_put(dev);
 313}
 314
 315/*
 316 * bcm_send_to_user - send a BCM message to the userspace
 317 *                    (consisting of bcm_msg_head + x CAN frames)
 318 */
 319static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
 320			     struct canfd_frame *frames, int has_timestamp)
 321{
 322	struct sk_buff *skb;
 323	struct canfd_frame *firstframe;
 324	struct sockaddr_can *addr;
 325	struct sock *sk = op->sk;
 326	unsigned int datalen = head->nframes * op->cfsiz;
 327	int err;
 328
 329	skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
 330	if (!skb)
 331		return;
 332
 333	skb_put_data(skb, head, sizeof(*head));
 334
 335	if (head->nframes) {
 336		/* CAN frames starting here */
 337		firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
 338
 339		skb_put_data(skb, frames, datalen);
 340
 341		/*
 342		 * the BCM uses the flags-element of the canfd_frame
 343		 * structure for internal purposes. This is only
 344		 * relevant for updates that are generated by the
 345		 * BCM, where nframes is 1
 346		 */
 347		if (head->nframes == 1)
 348			firstframe->flags &= BCM_CAN_FLAGS_MASK;
 349	}
 350
 351	if (has_timestamp) {
 352		/* restore rx timestamp */
 353		skb->tstamp = op->rx_stamp;
 354	}
 355
 356	/*
 357	 *  Put the datagram to the queue so that bcm_recvmsg() can
 358	 *  get it from there.  We need to pass the interface index to
 359	 *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 360	 *  containing the interface index.
 361	 */
 362
 363	sock_skb_cb_check_size(sizeof(struct sockaddr_can));
 364	addr = (struct sockaddr_can *)skb->cb;
 365	memset(addr, 0, sizeof(*addr));
 366	addr->can_family  = AF_CAN;
 367	addr->can_ifindex = op->rx_ifindex;
 368
 369	err = sock_queue_rcv_skb(sk, skb);
 370	if (err < 0) {
 371		struct bcm_sock *bo = bcm_sk(sk);
 372
 373		kfree_skb(skb);
 374		/* don't care about overflows in this statistic */
 375		bo->dropped_usr_msgs++;
 376	}
 377}
 378
 379static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
 380{
 381	ktime_t ival;
 382
 383	if (op->kt_ival1 && op->count)
 384		ival = op->kt_ival1;
 385	else if (op->kt_ival2)
 386		ival = op->kt_ival2;
 387	else
 388		return false;
 389
 390	hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
 391	return true;
 392}
 393
 394static void bcm_tx_start_timer(struct bcm_op *op)
 395{
 396	if (bcm_tx_set_expiry(op, &op->timer))
 397		hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
 398}
 399
 400/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
 401static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
 402{
 403	struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 404	struct bcm_msg_head msg_head;
 405
 406	if (op->kt_ival1 && (op->count > 0)) {
 407		op->count--;
 408		if (!op->count && (op->flags & TX_COUNTEVT)) {
 409
 410			/* create notification to user */
 411			memset(&msg_head, 0, sizeof(msg_head));
 412			msg_head.opcode  = TX_EXPIRED;
 413			msg_head.flags   = op->flags;
 414			msg_head.count   = op->count;
 415			msg_head.ival1   = op->ival1;
 416			msg_head.ival2   = op->ival2;
 417			msg_head.can_id  = op->can_id;
 418			msg_head.nframes = 0;
 419
 420			bcm_send_to_user(op, &msg_head, NULL, 0);
 421		}
 422		bcm_can_tx(op);
 423
 424	} else if (op->kt_ival2) {
 425		bcm_can_tx(op);
 426	}
 427
 428	return bcm_tx_set_expiry(op, &op->timer) ?
 429		HRTIMER_RESTART : HRTIMER_NORESTART;
 430}
 431
 432/*
 433 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
 434 */
 435static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
 436{
 437	struct bcm_msg_head head;
 438
 439	/* update statistics */
 440	op->frames_filtered++;
 441
 442	/* prevent statistics overflow */
 443	if (op->frames_filtered > ULONG_MAX/100)
 444		op->frames_filtered = op->frames_abs = 0;
 445
 446	/* this element is not throttled anymore */
 447	data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
 448
 449	memset(&head, 0, sizeof(head));
 450	head.opcode  = RX_CHANGED;
 451	head.flags   = op->flags;
 452	head.count   = op->count;
 453	head.ival1   = op->ival1;
 454	head.ival2   = op->ival2;
 455	head.can_id  = op->can_id;
 456	head.nframes = 1;
 457
 458	bcm_send_to_user(op, &head, data, 1);
 459}
 460
 461/*
 462 * bcm_rx_update_and_send - process a detected relevant receive content change
 463 *                          1. update the last received data
 464 *                          2. send a notification to the user (if possible)
 465 */
 466static void bcm_rx_update_and_send(struct bcm_op *op,
 467				   struct canfd_frame *lastdata,
 468				   const struct canfd_frame *rxdata)
 469{
 470	memcpy(lastdata, rxdata, op->cfsiz);
 471
 472	/* mark as used and throttled by default */
 473	lastdata->flags |= (RX_RECV|RX_THR);
 474
 475	/* throttling mode inactive ? */
 476	if (!op->kt_ival2) {
 477		/* send RX_CHANGED to the user immediately */
 478		bcm_rx_changed(op, lastdata);
 479		return;
 480	}
 481
 482	/* with active throttling timer we are just done here */
 483	if (hrtimer_active(&op->thrtimer))
 484		return;
 485
 486	/* first reception with enabled throttling mode */
 487	if (!op->kt_lastmsg)
 488		goto rx_changed_settime;
 489
 490	/* got a second frame inside a potential throttle period? */
 491	if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
 492	    ktime_to_us(op->kt_ival2)) {
 493		/* do not send the saved data - only start throttle timer */
 494		hrtimer_start(&op->thrtimer,
 495			      ktime_add(op->kt_lastmsg, op->kt_ival2),
 496			      HRTIMER_MODE_ABS_SOFT);
 497		return;
 498	}
 499
 500	/* the gap was that big, that throttling was not needed here */
 501rx_changed_settime:
 502	bcm_rx_changed(op, lastdata);
 503	op->kt_lastmsg = ktime_get();
 504}
 505
 506/*
 507 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
 508 *                       received data stored in op->last_frames[]
 509 */
 510static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
 511				const struct canfd_frame *rxdata)
 512{
 513	struct canfd_frame *cf = op->frames + op->cfsiz * index;
 514	struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
 515	int i;
 516
 517	/*
 518	 * no one uses the MSBs of flags for comparison,
 519	 * so we use it here to detect the first time of reception
 520	 */
 521
 522	if (!(lcf->flags & RX_RECV)) {
 523		/* received data for the first time => send update to user */
 524		bcm_rx_update_and_send(op, lcf, rxdata);
 525		return;
 526	}
 527
 528	/* do a real check in CAN frame data section */
 529	for (i = 0; i < rxdata->len; i += 8) {
 530		if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
 531		    (get_u64(cf, i) & get_u64(lcf, i))) {
 532			bcm_rx_update_and_send(op, lcf, rxdata);
 533			return;
 534		}
 535	}
 536
 537	if (op->flags & RX_CHECK_DLC) {
 538		/* do a real check in CAN frame length */
 539		if (rxdata->len != lcf->len) {
 540			bcm_rx_update_and_send(op, lcf, rxdata);
 541			return;
 542		}
 543	}
 544}
 545
 546/*
 547 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
 548 */
 549static void bcm_rx_starttimer(struct bcm_op *op)
 550{
 551	if (op->flags & RX_NO_AUTOTIMER)
 552		return;
 553
 554	if (op->kt_ival1)
 555		hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
 556}
 557
 558/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
 559static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
 560{
 561	struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 562	struct bcm_msg_head msg_head;
 563
 564	/* if user wants to be informed, when cyclic CAN-Messages come back */
 565	if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
 566		/* clear received CAN frames to indicate 'nothing received' */
 567		memset(op->last_frames, 0, op->nframes * op->cfsiz);
 568	}
 569
 570	/* create notification to user */
 571	memset(&msg_head, 0, sizeof(msg_head));
 572	msg_head.opcode  = RX_TIMEOUT;
 573	msg_head.flags   = op->flags;
 574	msg_head.count   = op->count;
 575	msg_head.ival1   = op->ival1;
 576	msg_head.ival2   = op->ival2;
 577	msg_head.can_id  = op->can_id;
 578	msg_head.nframes = 0;
 579
 580	bcm_send_to_user(op, &msg_head, NULL, 0);
 581
 582	return HRTIMER_NORESTART;
 583}
 584
 585/*
 586 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
 587 */
 588static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
 589{
 590	struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
 591
 592	if ((op->last_frames) && (lcf->flags & RX_THR)) {
 593		bcm_rx_changed(op, lcf);
 594		return 1;
 595	}
 596	return 0;
 597}
 598
 599/*
 600 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
 601 */
 602static int bcm_rx_thr_flush(struct bcm_op *op)
 603{
 604	int updated = 0;
 605
 606	if (op->nframes > 1) {
 607		unsigned int i;
 608
 609		/* for MUX filter we start at index 1 */
 610		for (i = 1; i < op->nframes; i++)
 611			updated += bcm_rx_do_flush(op, i);
 612
 613	} else {
 614		/* for RX_FILTER_ID and simple filter */
 615		updated += bcm_rx_do_flush(op, 0);
 616	}
 617
 618	return updated;
 619}
 620
 621/*
 622 * bcm_rx_thr_handler - the time for blocked content updates is over now:
 623 *                      Check for throttled data and send it to the userspace
 624 */
 625static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
 626{
 627	struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
 628
 629	if (bcm_rx_thr_flush(op)) {
 630		hrtimer_forward_now(hrtimer, op->kt_ival2);
 631		return HRTIMER_RESTART;
 632	} else {
 633		/* rearm throttle handling */
 634		op->kt_lastmsg = 0;
 635		return HRTIMER_NORESTART;
 636	}
 637}
 638
 639/*
 640 * bcm_rx_handler - handle a CAN frame reception
 641 */
 642static void bcm_rx_handler(struct sk_buff *skb, void *data)
 643{
 644	struct bcm_op *op = (struct bcm_op *)data;
 645	const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
 646	unsigned int i;
 647
 648	if (op->can_id != rxframe->can_id)
 649		return;
 650
 651	/* make sure to handle the correct frame type (CAN / CAN FD) */
 652	if (op->flags & CAN_FD_FRAME) {
 653		if (!can_is_canfd_skb(skb))
 654			return;
 655	} else {
 656		if (!can_is_can_skb(skb))
 657			return;
 658	}
 659
 660	/* disable timeout */
 661	hrtimer_cancel(&op->timer);
 662
 663	/* save rx timestamp */
 664	op->rx_stamp = skb->tstamp;
 665	/* save originator for recvfrom() */
 666	op->rx_ifindex = skb->dev->ifindex;
 667	/* update statistics */
 668	op->frames_abs++;
 669
 670	if (op->flags & RX_RTR_FRAME) {
 671		/* send reply for RTR-request (placed in op->frames[0]) */
 672		bcm_can_tx(op);
 673		return;
 674	}
 675
 676	if (op->flags & RX_FILTER_ID) {
 677		/* the easiest case */
 678		bcm_rx_update_and_send(op, op->last_frames, rxframe);
 679		goto rx_starttimer;
 680	}
 681
 682	if (op->nframes == 1) {
 683		/* simple compare with index 0 */
 684		bcm_rx_cmp_to_index(op, 0, rxframe);
 685		goto rx_starttimer;
 686	}
 687
 688	if (op->nframes > 1) {
 689		/*
 690		 * multiplex compare
 691		 *
 692		 * find the first multiplex mask that fits.
 693		 * Remark: The MUX-mask is stored in index 0 - but only the
 694		 * first 64 bits of the frame data[] are relevant (CAN FD)
 695		 */
 696
 697		for (i = 1; i < op->nframes; i++) {
 698			if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
 699			    (get_u64(op->frames, 0) &
 700			     get_u64(op->frames + op->cfsiz * i, 0))) {
 701				bcm_rx_cmp_to_index(op, i, rxframe);
 702				break;
 703			}
 704		}
 705	}
 706
 707rx_starttimer:
 708	bcm_rx_starttimer(op);
 709}
 710
 711/*
 712 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
 713 */
 714static struct bcm_op *bcm_find_op(struct list_head *ops,
 715				  struct bcm_msg_head *mh, int ifindex)
 716{
 717	struct bcm_op *op;
 718
 719	list_for_each_entry(op, ops, list) {
 720		if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 721		    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
 722			return op;
 723	}
 724
 725	return NULL;
 726}
 727
 728static void bcm_free_op_rcu(struct rcu_head *rcu_head)
 729{
 730	struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
 731
 732	if ((op->frames) && (op->frames != &op->sframe))
 733		kfree(op->frames);
 734
 735	if ((op->last_frames) && (op->last_frames != &op->last_sframe))
 736		kfree(op->last_frames);
 737
 738	kfree(op);
 739}
 740
 741static void bcm_remove_op(struct bcm_op *op)
 742{
 743	hrtimer_cancel(&op->timer);
 744	hrtimer_cancel(&op->thrtimer);
 745
 746	call_rcu(&op->rcu, bcm_free_op_rcu);
 747}
 748
 749static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
 750{
 751	if (op->rx_reg_dev == dev) {
 752		can_rx_unregister(dev_net(dev), dev, op->can_id,
 753				  REGMASK(op->can_id), bcm_rx_handler, op);
 754
 755		/* mark as removed subscription */
 756		op->rx_reg_dev = NULL;
 757	} else
 758		printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
 759		       "mismatch %p %p\n", op->rx_reg_dev, dev);
 760}
 761
 762/*
 763 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
 764 */
 765static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
 766			    int ifindex)
 767{
 768	struct bcm_op *op, *n;
 769
 770	list_for_each_entry_safe(op, n, ops, list) {
 771		if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 772		    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
 773
 774			/* disable automatic timer on frame reception */
 775			op->flags |= RX_NO_AUTOTIMER;
 776
 777			/*
 778			 * Don't care if we're bound or not (due to netdev
 779			 * problems) can_rx_unregister() is always a save
 780			 * thing to do here.
 781			 */
 782			if (op->ifindex) {
 783				/*
 784				 * Only remove subscriptions that had not
 785				 * been removed due to NETDEV_UNREGISTER
 786				 * in bcm_notifier()
 787				 */
 788				if (op->rx_reg_dev) {
 789					struct net_device *dev;
 790
 791					dev = dev_get_by_index(sock_net(op->sk),
 792							       op->ifindex);
 793					if (dev) {
 794						bcm_rx_unreg(dev, op);
 795						dev_put(dev);
 796					}
 797				}
 798			} else
 799				can_rx_unregister(sock_net(op->sk), NULL,
 800						  op->can_id,
 801						  REGMASK(op->can_id),
 802						  bcm_rx_handler, op);
 803
 804			list_del(&op->list);
 805			bcm_remove_op(op);
 806			return 1; /* done */
 807		}
 808	}
 809
 810	return 0; /* not found */
 811}
 812
 813/*
 814 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
 815 */
 816static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
 817			    int ifindex)
 818{
 819	struct bcm_op *op, *n;
 820
 821	list_for_each_entry_safe(op, n, ops, list) {
 822		if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 823		    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
 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_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
 835 */
 836static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
 837		       int ifindex)
 838{
 839	struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
 840
 841	if (!op)
 842		return -EINVAL;
 843
 844	/* put current values into msg_head */
 845	msg_head->flags   = op->flags;
 846	msg_head->count   = op->count;
 847	msg_head->ival1   = op->ival1;
 848	msg_head->ival2   = op->ival2;
 849	msg_head->nframes = op->nframes;
 850
 851	bcm_send_to_user(op, msg_head, op->frames, 0);
 852
 853	return MHSIZ;
 854}
 855
 856/*
 857 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
 858 */
 859static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 860			int ifindex, struct sock *sk)
 861{
 862	struct bcm_sock *bo = bcm_sk(sk);
 863	struct bcm_op *op;
 864	struct canfd_frame *cf;
 865	unsigned int i;
 866	int err;
 867
 868	/* we need a real device to send frames */
 869	if (!ifindex)
 870		return -ENODEV;
 871
 872	/* check nframes boundaries - we need at least one CAN frame */
 873	if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
 874		return -EINVAL;
 875
 876	/* check timeval limitations */
 877	if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
 878		return -EINVAL;
 879
 880	/* check the given can_id */
 881	op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
 882	if (op) {
 883		/* update existing BCM operation */
 884
 885		/*
 886		 * Do we need more space for the CAN frames than currently
 887		 * allocated? -> This is a _really_ unusual use-case and
 888		 * therefore (complexity / locking) it is not supported.
 889		 */
 890		if (msg_head->nframes > op->nframes)
 891			return -E2BIG;
 892
 893		/* update CAN frames content */
 894		for (i = 0; i < msg_head->nframes; i++) {
 895
 896			cf = op->frames + op->cfsiz * i;
 897			err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
 898
 899			if (op->flags & CAN_FD_FRAME) {
 900				if (cf->len > 64)
 901					err = -EINVAL;
 902			} else {
 903				if (cf->len > 8)
 904					err = -EINVAL;
 905			}
 906
 907			if (err < 0)
 908				return err;
 909
 910			if (msg_head->flags & TX_CP_CAN_ID) {
 911				/* copy can_id into frame */
 912				cf->can_id = msg_head->can_id;
 913			}
 914		}
 915		op->flags = msg_head->flags;
 916
 917	} else {
 918		/* insert new BCM operation for the given can_id */
 919
 920		op = kzalloc(OPSIZ, GFP_KERNEL);
 921		if (!op)
 922			return -ENOMEM;
 923
 924		op->can_id = msg_head->can_id;
 925		op->cfsiz = CFSIZ(msg_head->flags);
 926		op->flags = msg_head->flags;
 927
 928		/* create array for CAN frames and copy the data */
 929		if (msg_head->nframes > 1) {
 930			op->frames = kmalloc_array(msg_head->nframes,
 931						   op->cfsiz,
 932						   GFP_KERNEL);
 933			if (!op->frames) {
 934				kfree(op);
 935				return -ENOMEM;
 936			}
 937		} else
 938			op->frames = &op->sframe;
 939
 940		for (i = 0; i < msg_head->nframes; i++) {
 941
 942			cf = op->frames + op->cfsiz * i;
 943			err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
 
 
 944
 945			if (op->flags & CAN_FD_FRAME) {
 946				if (cf->len > 64)
 947					err = -EINVAL;
 948			} else {
 949				if (cf->len > 8)
 950					err = -EINVAL;
 951			}
 952
 953			if (err < 0) {
 954				if (op->frames != &op->sframe)
 955					kfree(op->frames);
 956				kfree(op);
 957				return err;
 958			}
 959
 960			if (msg_head->flags & TX_CP_CAN_ID) {
 961				/* copy can_id into frame */
 962				cf->can_id = msg_head->can_id;
 963			}
 964		}
 965
 966		/* tx_ops never compare with previous received messages */
 967		op->last_frames = NULL;
 968
 969		/* bcm_can_tx / bcm_tx_timeout_handler needs this */
 970		op->sk = sk;
 971		op->ifindex = ifindex;
 972
 973		/* initialize uninitialized (kzalloc) structure */
 974		hrtimer_init(&op->timer, CLOCK_MONOTONIC,
 975			     HRTIMER_MODE_REL_SOFT);
 976		op->timer.function = bcm_tx_timeout_handler;
 977
 978		/* currently unused in tx_ops */
 979		hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
 980			     HRTIMER_MODE_REL_SOFT);
 981
 982		/* add this bcm_op to the list of the tx_ops */
 983		list_add(&op->list, &bo->tx_ops);
 984
 985	} /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
 986
 987	if (op->nframes != msg_head->nframes) {
 988		op->nframes   = msg_head->nframes;
 989		/* start multiple frame transmission with index 0 */
 990		op->currframe = 0;
 991	}
 992
 993	/* check flags */
 994
 995	if (op->flags & TX_RESET_MULTI_IDX) {
 996		/* start multiple frame transmission with index 0 */
 997		op->currframe = 0;
 998	}
 999
1000	if (op->flags & SETTIMER) {
1001		/* set timer values */
1002		op->count = msg_head->count;
1003		op->ival1 = msg_head->ival1;
1004		op->ival2 = msg_head->ival2;
1005		op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1006		op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1007
1008		/* disable an active timer due to zero values? */
1009		if (!op->kt_ival1 && !op->kt_ival2)
1010			hrtimer_cancel(&op->timer);
1011	}
1012
1013	if (op->flags & STARTTIMER) {
1014		hrtimer_cancel(&op->timer);
1015		/* spec: send CAN frame when starting timer */
1016		op->flags |= TX_ANNOUNCE;
1017	}
1018
1019	if (op->flags & TX_ANNOUNCE) {
1020		bcm_can_tx(op);
1021		if (op->count)
1022			op->count--;
1023	}
1024
1025	if (op->flags & STARTTIMER)
1026		bcm_tx_start_timer(op);
1027
1028	return msg_head->nframes * op->cfsiz + MHSIZ;
 
 
 
 
 
 
1029}
1030
1031/*
1032 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1033 */
1034static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1035			int ifindex, struct sock *sk)
1036{
1037	struct bcm_sock *bo = bcm_sk(sk);
1038	struct bcm_op *op;
1039	int do_rx_register;
1040	int err = 0;
1041
1042	if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1043		/* be robust against wrong usage ... */
1044		msg_head->flags |= RX_FILTER_ID;
1045		/* ignore trailing garbage */
1046		msg_head->nframes = 0;
1047	}
1048
1049	/* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1050	if (msg_head->nframes > MAX_NFRAMES + 1)
1051		return -EINVAL;
1052
1053	if ((msg_head->flags & RX_RTR_FRAME) &&
1054	    ((msg_head->nframes != 1) ||
1055	     (!(msg_head->can_id & CAN_RTR_FLAG))))
1056		return -EINVAL;
1057
1058	/* check timeval limitations */
1059	if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1060		return -EINVAL;
1061
1062	/* check the given can_id */
1063	op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1064	if (op) {
1065		/* update existing BCM operation */
1066
1067		/*
1068		 * Do we need more space for the CAN frames than currently
1069		 * allocated? -> This is a _really_ unusual use-case and
1070		 * therefore (complexity / locking) it is not supported.
1071		 */
1072		if (msg_head->nframes > op->nframes)
1073			return -E2BIG;
1074
1075		if (msg_head->nframes) {
1076			/* update CAN frames content */
1077			err = memcpy_from_msg(op->frames, msg,
1078					      msg_head->nframes * op->cfsiz);
1079			if (err < 0)
1080				return err;
1081
1082			/* clear last_frames to indicate 'nothing received' */
1083			memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1084		}
1085
1086		op->nframes = msg_head->nframes;
1087		op->flags = msg_head->flags;
1088
1089		/* Only an update -> do not call can_rx_register() */
1090		do_rx_register = 0;
1091
1092	} else {
1093		/* insert new BCM operation for the given can_id */
1094		op = kzalloc(OPSIZ, GFP_KERNEL);
1095		if (!op)
1096			return -ENOMEM;
1097
1098		op->can_id = msg_head->can_id;
1099		op->nframes = msg_head->nframes;
1100		op->cfsiz = CFSIZ(msg_head->flags);
1101		op->flags = msg_head->flags;
1102
1103		if (msg_head->nframes > 1) {
1104			/* create array for CAN frames and copy the data */
1105			op->frames = kmalloc_array(msg_head->nframes,
1106						   op->cfsiz,
1107						   GFP_KERNEL);
1108			if (!op->frames) {
1109				kfree(op);
1110				return -ENOMEM;
1111			}
1112
1113			/* create and init array for received CAN frames */
1114			op->last_frames = kcalloc(msg_head->nframes,
1115						  op->cfsiz,
1116						  GFP_KERNEL);
1117			if (!op->last_frames) {
1118				kfree(op->frames);
1119				kfree(op);
1120				return -ENOMEM;
1121			}
1122
1123		} else {
1124			op->frames = &op->sframe;
1125			op->last_frames = &op->last_sframe;
1126		}
1127
1128		if (msg_head->nframes) {
1129			err = memcpy_from_msg(op->frames, msg,
1130					      msg_head->nframes * op->cfsiz);
1131			if (err < 0) {
1132				if (op->frames != &op->sframe)
1133					kfree(op->frames);
1134				if (op->last_frames != &op->last_sframe)
1135					kfree(op->last_frames);
1136				kfree(op);
1137				return err;
1138			}
1139		}
1140
1141		/* bcm_can_tx / bcm_tx_timeout_handler needs this */
1142		op->sk = sk;
1143		op->ifindex = ifindex;
1144
1145		/* ifindex for timeout events w/o previous frame reception */
1146		op->rx_ifindex = ifindex;
1147
1148		/* initialize uninitialized (kzalloc) structure */
1149		hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1150			     HRTIMER_MODE_REL_SOFT);
1151		op->timer.function = bcm_rx_timeout_handler;
1152
1153		hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1154			     HRTIMER_MODE_REL_SOFT);
1155		op->thrtimer.function = bcm_rx_thr_handler;
1156
1157		/* add this bcm_op to the list of the rx_ops */
1158		list_add(&op->list, &bo->rx_ops);
1159
1160		/* call can_rx_register() */
1161		do_rx_register = 1;
1162
1163	} /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1164
1165	/* check flags */
1166
1167	if (op->flags & RX_RTR_FRAME) {
1168		struct canfd_frame *frame0 = op->frames;
1169
1170		/* no timers in RTR-mode */
1171		hrtimer_cancel(&op->thrtimer);
1172		hrtimer_cancel(&op->timer);
1173
1174		/*
1175		 * funny feature in RX(!)_SETUP only for RTR-mode:
1176		 * copy can_id into frame BUT without RTR-flag to
1177		 * prevent a full-load-loopback-test ... ;-]
1178		 */
1179		if ((op->flags & TX_CP_CAN_ID) ||
1180		    (frame0->can_id == op->can_id))
1181			frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1182
1183	} else {
1184		if (op->flags & SETTIMER) {
1185
1186			/* set timer value */
1187			op->ival1 = msg_head->ival1;
1188			op->ival2 = msg_head->ival2;
1189			op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1190			op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1191
1192			/* disable an active timer due to zero value? */
1193			if (!op->kt_ival1)
1194				hrtimer_cancel(&op->timer);
1195
1196			/*
1197			 * In any case cancel the throttle timer, flush
1198			 * potentially blocked msgs and reset throttle handling
1199			 */
1200			op->kt_lastmsg = 0;
1201			hrtimer_cancel(&op->thrtimer);
1202			bcm_rx_thr_flush(op);
1203		}
1204
1205		if ((op->flags & STARTTIMER) && op->kt_ival1)
1206			hrtimer_start(&op->timer, op->kt_ival1,
1207				      HRTIMER_MODE_REL_SOFT);
1208	}
1209
1210	/* now we can register for can_ids, if we added a new bcm_op */
1211	if (do_rx_register) {
1212		if (ifindex) {
1213			struct net_device *dev;
1214
1215			dev = dev_get_by_index(sock_net(sk), ifindex);
1216			if (dev) {
1217				err = can_rx_register(sock_net(sk), dev,
1218						      op->can_id,
1219						      REGMASK(op->can_id),
1220						      bcm_rx_handler, op,
1221						      "bcm", sk);
1222
1223				op->rx_reg_dev = dev;
1224				dev_put(dev);
1225			}
1226
1227		} else
1228			err = can_rx_register(sock_net(sk), NULL, op->can_id,
1229					      REGMASK(op->can_id),
1230					      bcm_rx_handler, op, "bcm", sk);
1231		if (err) {
1232			/* this bcm rx op is broken -> remove it */
1233			list_del(&op->list);
1234			bcm_remove_op(op);
1235			return err;
1236		}
1237	}
1238
1239	return msg_head->nframes * op->cfsiz + MHSIZ;
1240}
1241
1242/*
1243 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1244 */
1245static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1246		       int cfsiz)
1247{
1248	struct sk_buff *skb;
1249	struct net_device *dev;
1250	int err;
1251
1252	/* we need a real device to send frames */
1253	if (!ifindex)
1254		return -ENODEV;
1255
1256	skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1257	if (!skb)
1258		return -ENOMEM;
1259
1260	can_skb_reserve(skb);
1261
1262	err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1263	if (err < 0) {
1264		kfree_skb(skb);
1265		return err;
1266	}
1267
1268	dev = dev_get_by_index(sock_net(sk), ifindex);
1269	if (!dev) {
1270		kfree_skb(skb);
1271		return -ENODEV;
1272	}
1273
1274	can_skb_prv(skb)->ifindex = dev->ifindex;
1275	can_skb_prv(skb)->skbcnt = 0;
1276	skb->dev = dev;
1277	can_skb_set_owner(skb, sk);
1278	err = can_send(skb, 1); /* send with loopback */
1279	dev_put(dev);
1280
1281	if (err)
1282		return err;
1283
1284	return cfsiz + MHSIZ;
1285}
1286
1287/*
1288 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1289 */
1290static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1291{
1292	struct sock *sk = sock->sk;
1293	struct bcm_sock *bo = bcm_sk(sk);
1294	int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1295	struct bcm_msg_head msg_head;
1296	int cfsiz;
1297	int ret; /* read bytes or error codes as return value */
1298
1299	if (!bo->bound)
1300		return -ENOTCONN;
1301
1302	/* check for valid message length from userspace */
1303	if (size < MHSIZ)
1304		return -EINVAL;
1305
1306	/* read message head information */
1307	ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1308	if (ret < 0)
1309		return ret;
1310
1311	cfsiz = CFSIZ(msg_head.flags);
1312	if ((size - MHSIZ) % cfsiz)
1313		return -EINVAL;
1314
1315	/* check for alternative ifindex for this bcm_op */
1316
1317	if (!ifindex && msg->msg_name) {
1318		/* no bound device as default => check msg_name */
1319		DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1320
1321		if (msg->msg_namelen < BCM_MIN_NAMELEN)
1322			return -EINVAL;
1323
1324		if (addr->can_family != AF_CAN)
1325			return -EINVAL;
1326
1327		/* ifindex from sendto() */
1328		ifindex = addr->can_ifindex;
1329
1330		if (ifindex) {
1331			struct net_device *dev;
1332
1333			dev = dev_get_by_index(sock_net(sk), ifindex);
1334			if (!dev)
1335				return -ENODEV;
1336
1337			if (dev->type != ARPHRD_CAN) {
1338				dev_put(dev);
1339				return -ENODEV;
1340			}
1341
1342			dev_put(dev);
1343		}
1344	}
1345
1346	lock_sock(sk);
1347
1348	switch (msg_head.opcode) {
1349
1350	case TX_SETUP:
1351		ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1352		break;
1353
1354	case RX_SETUP:
1355		ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1356		break;
1357
1358	case TX_DELETE:
1359		if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1360			ret = MHSIZ;
1361		else
1362			ret = -EINVAL;
1363		break;
1364
1365	case RX_DELETE:
1366		if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1367			ret = MHSIZ;
1368		else
1369			ret = -EINVAL;
1370		break;
1371
1372	case TX_READ:
1373		/* reuse msg_head for the reply to TX_READ */
1374		msg_head.opcode  = TX_STATUS;
1375		ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1376		break;
1377
1378	case RX_READ:
1379		/* reuse msg_head for the reply to RX_READ */
1380		msg_head.opcode  = RX_STATUS;
1381		ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1382		break;
1383
1384	case TX_SEND:
1385		/* we need exactly one CAN frame behind the msg head */
1386		if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1387			ret = -EINVAL;
1388		else
1389			ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1390		break;
1391
1392	default:
1393		ret = -EINVAL;
1394		break;
1395	}
1396
1397	release_sock(sk);
1398
1399	return ret;
1400}
1401
1402/*
1403 * notification handler for netdevice status changes
1404 */
1405static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1406		       struct net_device *dev)
1407{
1408	struct sock *sk = &bo->sk;
1409	struct bcm_op *op;
1410	int notify_enodev = 0;
1411
1412	if (!net_eq(dev_net(dev), sock_net(sk)))
1413		return;
1414
1415	switch (msg) {
1416
1417	case NETDEV_UNREGISTER:
1418		lock_sock(sk);
1419
1420		/* remove device specific receive entries */
1421		list_for_each_entry(op, &bo->rx_ops, list)
1422			if (op->rx_reg_dev == dev)
1423				bcm_rx_unreg(dev, op);
1424
1425		/* remove device reference, if this is our bound device */
1426		if (bo->bound && bo->ifindex == dev->ifindex) {
1427			bo->bound   = 0;
1428			bo->ifindex = 0;
1429			notify_enodev = 1;
1430		}
1431
1432		release_sock(sk);
1433
1434		if (notify_enodev) {
1435			sk->sk_err = ENODEV;
1436			if (!sock_flag(sk, SOCK_DEAD))
1437				sk_error_report(sk);
1438		}
1439		break;
1440
1441	case NETDEV_DOWN:
1442		if (bo->bound && bo->ifindex == dev->ifindex) {
1443			sk->sk_err = ENETDOWN;
1444			if (!sock_flag(sk, SOCK_DEAD))
1445				sk_error_report(sk);
1446		}
1447	}
1448}
1449
1450static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1451			void *ptr)
1452{
1453	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1454
1455	if (dev->type != ARPHRD_CAN)
1456		return NOTIFY_DONE;
1457	if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1458		return NOTIFY_DONE;
1459	if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1460		return NOTIFY_DONE;
1461
1462	spin_lock(&bcm_notifier_lock);
1463	list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1464		spin_unlock(&bcm_notifier_lock);
1465		bcm_notify(bcm_busy_notifier, msg, dev);
1466		spin_lock(&bcm_notifier_lock);
1467	}
1468	bcm_busy_notifier = NULL;
1469	spin_unlock(&bcm_notifier_lock);
1470	return NOTIFY_DONE;
1471}
1472
1473/*
1474 * initial settings for all BCM sockets to be set at socket creation time
1475 */
1476static int bcm_init(struct sock *sk)
1477{
1478	struct bcm_sock *bo = bcm_sk(sk);
1479
1480	bo->bound            = 0;
1481	bo->ifindex          = 0;
1482	bo->dropped_usr_msgs = 0;
1483	bo->bcm_proc_read    = NULL;
1484
1485	INIT_LIST_HEAD(&bo->tx_ops);
1486	INIT_LIST_HEAD(&bo->rx_ops);
1487
1488	/* set notifier */
1489	spin_lock(&bcm_notifier_lock);
1490	list_add_tail(&bo->notifier, &bcm_notifier_list);
1491	spin_unlock(&bcm_notifier_lock);
1492
1493	return 0;
1494}
1495
1496/*
1497 * standard socket functions
1498 */
1499static int bcm_release(struct socket *sock)
1500{
1501	struct sock *sk = sock->sk;
1502	struct net *net;
1503	struct bcm_sock *bo;
1504	struct bcm_op *op, *next;
1505
1506	if (!sk)
1507		return 0;
1508
1509	net = sock_net(sk);
1510	bo = bcm_sk(sk);
1511
1512	/* remove bcm_ops, timer, rx_unregister(), etc. */
1513
1514	spin_lock(&bcm_notifier_lock);
1515	while (bcm_busy_notifier == bo) {
1516		spin_unlock(&bcm_notifier_lock);
1517		schedule_timeout_uninterruptible(1);
1518		spin_lock(&bcm_notifier_lock);
1519	}
1520	list_del(&bo->notifier);
1521	spin_unlock(&bcm_notifier_lock);
1522
1523	lock_sock(sk);
1524
 
 
 
 
 
 
1525	list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1526		bcm_remove_op(op);
1527
1528	list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1529		/*
1530		 * Don't care if we're bound or not (due to netdev problems)
1531		 * can_rx_unregister() is always a save thing to do here.
1532		 */
1533		if (op->ifindex) {
1534			/*
1535			 * Only remove subscriptions that had not
1536			 * been removed due to NETDEV_UNREGISTER
1537			 * in bcm_notifier()
1538			 */
1539			if (op->rx_reg_dev) {
1540				struct net_device *dev;
1541
1542				dev = dev_get_by_index(net, op->ifindex);
1543				if (dev) {
1544					bcm_rx_unreg(dev, op);
1545					dev_put(dev);
1546				}
1547			}
1548		} else
1549			can_rx_unregister(net, NULL, op->can_id,
1550					  REGMASK(op->can_id),
1551					  bcm_rx_handler, op);
1552
1553	}
1554
1555	synchronize_rcu();
1556
1557	list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1558		bcm_remove_op(op);
1559
1560#if IS_ENABLED(CONFIG_PROC_FS)
1561	/* remove procfs entry */
1562	if (net->can.bcmproc_dir && bo->bcm_proc_read)
1563		remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1564#endif /* CONFIG_PROC_FS */
1565
1566	/* remove device reference */
1567	if (bo->bound) {
1568		bo->bound   = 0;
1569		bo->ifindex = 0;
1570	}
1571
1572	sock_orphan(sk);
1573	sock->sk = NULL;
1574
1575	release_sock(sk);
1576	sock_put(sk);
1577
1578	return 0;
1579}
1580
1581static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1582		       int flags)
1583{
1584	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1585	struct sock *sk = sock->sk;
1586	struct bcm_sock *bo = bcm_sk(sk);
1587	struct net *net = sock_net(sk);
1588	int ret = 0;
1589
1590	if (len < BCM_MIN_NAMELEN)
1591		return -EINVAL;
1592
1593	lock_sock(sk);
1594
1595	if (bo->bound) {
1596		ret = -EISCONN;
1597		goto fail;
1598	}
1599
1600	/* bind a device to this socket */
1601	if (addr->can_ifindex) {
1602		struct net_device *dev;
1603
1604		dev = dev_get_by_index(net, addr->can_ifindex);
1605		if (!dev) {
1606			ret = -ENODEV;
1607			goto fail;
1608		}
1609		if (dev->type != ARPHRD_CAN) {
1610			dev_put(dev);
1611			ret = -ENODEV;
1612			goto fail;
1613		}
1614
1615		bo->ifindex = dev->ifindex;
1616		dev_put(dev);
1617
1618	} else {
1619		/* no interface reference for ifindex = 0 ('any' CAN device) */
1620		bo->ifindex = 0;
1621	}
1622
1623#if IS_ENABLED(CONFIG_PROC_FS)
1624	if (net->can.bcmproc_dir) {
1625		/* unique socket address as filename */
1626		sprintf(bo->procname, "%lu", sock_i_ino(sk));
1627		bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1628						     net->can.bcmproc_dir,
1629						     bcm_proc_show, sk);
1630		if (!bo->bcm_proc_read) {
1631			ret = -ENOMEM;
1632			goto fail;
1633		}
1634	}
1635#endif /* CONFIG_PROC_FS */
1636
1637	bo->bound = 1;
1638
1639fail:
1640	release_sock(sk);
1641
1642	return ret;
1643}
1644
1645static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1646		       int flags)
1647{
1648	struct sock *sk = sock->sk;
1649	struct sk_buff *skb;
1650	int error = 0;
1651	int err;
1652
1653	skb = skb_recv_datagram(sk, flags, &error);
1654	if (!skb)
1655		return error;
1656
1657	if (skb->len < size)
1658		size = skb->len;
1659
1660	err = memcpy_to_msg(msg, skb->data, size);
1661	if (err < 0) {
1662		skb_free_datagram(sk, skb);
1663		return err;
1664	}
1665
1666	sock_recv_cmsgs(msg, sk, skb);
1667
1668	if (msg->msg_name) {
1669		__sockaddr_check_size(BCM_MIN_NAMELEN);
1670		msg->msg_namelen = BCM_MIN_NAMELEN;
1671		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1672	}
1673
1674	skb_free_datagram(sk, skb);
1675
1676	return size;
1677}
1678
1679static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1680				unsigned long arg)
1681{
1682	/* no ioctls for socket layer -> hand it down to NIC layer */
1683	return -ENOIOCTLCMD;
1684}
1685
1686static const struct proto_ops bcm_ops = {
1687	.family        = PF_CAN,
1688	.release       = bcm_release,
1689	.bind          = sock_no_bind,
1690	.connect       = bcm_connect,
1691	.socketpair    = sock_no_socketpair,
1692	.accept        = sock_no_accept,
1693	.getname       = sock_no_getname,
1694	.poll          = datagram_poll,
1695	.ioctl         = bcm_sock_no_ioctlcmd,
1696	.gettstamp     = sock_gettstamp,
1697	.listen        = sock_no_listen,
1698	.shutdown      = sock_no_shutdown,
1699	.sendmsg       = bcm_sendmsg,
1700	.recvmsg       = bcm_recvmsg,
1701	.mmap          = sock_no_mmap,
1702	.sendpage      = sock_no_sendpage,
1703};
1704
1705static struct proto bcm_proto __read_mostly = {
1706	.name       = "CAN_BCM",
1707	.owner      = THIS_MODULE,
1708	.obj_size   = sizeof(struct bcm_sock),
1709	.init       = bcm_init,
1710};
1711
1712static const struct can_proto bcm_can_proto = {
1713	.type       = SOCK_DGRAM,
1714	.protocol   = CAN_BCM,
1715	.ops        = &bcm_ops,
1716	.prot       = &bcm_proto,
1717};
1718
1719static int canbcm_pernet_init(struct net *net)
1720{
1721#if IS_ENABLED(CONFIG_PROC_FS)
1722	/* create /proc/net/can-bcm directory */
1723	net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1724#endif /* CONFIG_PROC_FS */
1725
1726	return 0;
1727}
1728
1729static void canbcm_pernet_exit(struct net *net)
1730{
1731#if IS_ENABLED(CONFIG_PROC_FS)
1732	/* remove /proc/net/can-bcm directory */
1733	if (net->can.bcmproc_dir)
1734		remove_proc_entry("can-bcm", net->proc_net);
1735#endif /* CONFIG_PROC_FS */
1736}
1737
1738static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1739	.init = canbcm_pernet_init,
1740	.exit = canbcm_pernet_exit,
1741};
1742
1743static struct notifier_block canbcm_notifier = {
1744	.notifier_call = bcm_notifier
1745};
1746
1747static int __init bcm_module_init(void)
1748{
1749	int err;
1750
1751	pr_info("can: broadcast manager protocol\n");
1752
1753	err = register_pernet_subsys(&canbcm_pernet_ops);
1754	if (err)
1755		return err;
1756
1757	err = register_netdevice_notifier(&canbcm_notifier);
1758	if (err)
1759		goto register_notifier_failed;
1760
1761	err = can_proto_register(&bcm_can_proto);
1762	if (err < 0) {
1763		printk(KERN_ERR "can: registration of bcm protocol failed\n");
1764		goto register_proto_failed;
1765	}
1766
1767	return 0;
1768
1769register_proto_failed:
1770	unregister_netdevice_notifier(&canbcm_notifier);
1771register_notifier_failed:
1772	unregister_pernet_subsys(&canbcm_pernet_ops);
1773	return err;
1774}
1775
1776static void __exit bcm_module_exit(void)
1777{
1778	can_proto_unregister(&bcm_can_proto);
1779	unregister_netdevice_notifier(&canbcm_notifier);
1780	unregister_pernet_subsys(&canbcm_pernet_ops);
1781}
1782
1783module_init(bcm_module_init);
1784module_exit(bcm_module_exit);