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