1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /*
3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 *
5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of Volkswagen nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * Alternatively, provided that this notice is retained in full, this
21 * software may be distributed under the terms of the GNU General
22 * Public License ("GPL") version 2, in which case the provisions of the
23 * GPL apply INSTEAD OF those given above.
24 *
25 * The provided data structures and external interfaces from this code
26 * are not restricted to be used by modules with a GPL compatible license.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
39 * DAMAGE.
40 *
41 */
42
43 #include <linux/module.h>
44 #include <linux/init.h>
45 #include <linux/interrupt.h>
46 #include <linux/hrtimer.h>
47 #include <linux/list.h>
48 #include <linux/proc_fs.h>
49 #include <linux/seq_file.h>
50 #include <linux/uio.h>
51 #include <linux/net.h>
52 #include <linux/netdevice.h>
53 #include <linux/socket.h>
54 #include <linux/if_arp.h>
55 #include <linux/skbuff.h>
56 #include <linux/can.h>
57 #include <linux/can/core.h>
58 #include <linux/can/skb.h>
59 #include <linux/can/bcm.h>
60 #include <linux/slab.h>
61 #include <net/sock.h>
62 #include <net/net_namespace.h>
63
64 /*
65 * To send multiple CAN frame content within TX_SETUP or to filter
66 * CAN messages with multiplex index within RX_SETUP, the number of
67 * different filters is limited to 256 due to the one byte index value.
68 */
69 #define MAX_NFRAMES 256
70
71 /* limit timers to 400 days for sending/timeouts */
72 #define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
73
74 /* use of last_frames[index].flags */
75 #define RX_RECV 0x40 /* received data for this element */
76 #define RX_THR 0x80 /* element not been sent due to throttle feature */
77 #define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
78
79 /* get best masking value for can_rx_register() for a given single can_id */
80 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
81 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
82 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
83
84 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
85 MODULE_LICENSE("Dual BSD/GPL");
86 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
87 MODULE_ALIAS("can-proto-2");
88
89 #define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
90
91 /*
92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
95 */
get_u64(const struct canfd_frame * cp,int offset)96 static inline u64 get_u64(const struct canfd_frame *cp, int offset)
97 {
98 return *(u64 *)(cp->data + offset);
99 }
100
101 struct bcm_op {
102 struct list_head list;
103 int ifindex;
104 canid_t can_id;
105 u32 flags;
106 unsigned long frames_abs, frames_filtered;
107 struct bcm_timeval ival1, ival2;
108 struct hrtimer timer, thrtimer;
109 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
124 struct 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
136 static LIST_HEAD(bcm_notifier_list);
137 static DEFINE_SPINLOCK(bcm_notifier_lock);
138 static struct bcm_sock *bcm_busy_notifier;
139
bcm_sk(const struct sock * sk)140 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
141 {
142 return (struct bcm_sock *)sk;
143 }
144
bcm_timeval_to_ktime(struct bcm_timeval tv)145 static 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 */
bcm_is_invalid_tv(struct bcm_msg_head * msg_head)151 static 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)
bcm_proc_getifname(struct net * net,char * result,int ifindex)174 static 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
bcm_proc_show(struct seq_file * m,void * v)192 static 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 */
bcm_can_tx(struct bcm_op * op)271 static 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;
309 out:
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 */
bcm_send_to_user(struct bcm_op * op,struct bcm_msg_head * head,struct canfd_frame * frames,int has_timestamp)317 static 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
bcm_tx_set_expiry(struct bcm_op * op,struct hrtimer * hrt)377 static 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
bcm_tx_start_timer(struct bcm_op * op)392 static 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 */
bcm_tx_timeout_handler(struct hrtimer * hrtimer)399 static 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 */
bcm_rx_changed(struct bcm_op * op,struct canfd_frame * data)433 static 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 */
bcm_rx_update_and_send(struct bcm_op * op,struct canfd_frame * lastdata,const struct canfd_frame * rxdata)464 static 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 */
499 rx_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 */
bcm_rx_cmp_to_index(struct bcm_op * op,unsigned int index,const struct canfd_frame * rxdata)508 static 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 */
bcm_rx_starttimer(struct bcm_op * op)547 static 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 */
bcm_rx_timeout_handler(struct hrtimer * hrtimer)557 static 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 */
bcm_rx_do_flush(struct bcm_op * op,unsigned int index)586 static 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 */
bcm_rx_thr_flush(struct bcm_op * op)600 static 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 */
bcm_rx_thr_handler(struct hrtimer * hrtimer)623 static 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 */
bcm_rx_handler(struct sk_buff * skb,void * data)640 static 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
700 rx_starttimer:
701 bcm_rx_starttimer(op);
702 }
703
704 /*
705 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
706 */
bcm_find_op(struct list_head * ops,struct bcm_msg_head * mh,int ifindex)707 static 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
bcm_remove_op(struct bcm_op * op)721 static 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
bcm_rx_unreg(struct net_device * dev,struct bcm_op * op)735 static 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 */
bcm_delete_rx_op(struct list_head * ops,struct bcm_msg_head * mh,int ifindex)751 static 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 */
bcm_delete_tx_op(struct list_head * ops,struct bcm_msg_head * mh,int ifindex)800 static 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 */
bcm_read_op(struct list_head * ops,struct bcm_msg_head * msg_head,int ifindex)820 static 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 */
bcm_tx_setup(struct bcm_msg_head * msg_head,struct msghdr * msg,int ifindex,struct sock * sk)843 static 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 */
bcm_rx_setup(struct bcm_msg_head * msg_head,struct msghdr * msg,int ifindex,struct sock * sk)1018 static 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 */
bcm_tx_send(struct msghdr * msg,int ifindex,struct sock * sk,int cfsiz)1229 static 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 */
bcm_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)1274 static 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 */
bcm_notify(struct bcm_sock * bo,unsigned long msg,struct net_device * dev)1389 static 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
bcm_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)1434 static 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 */
bcm_init(struct sock * sk)1460 static 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 */
bcm_release(struct socket * sock)1483 static 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
bcm_connect(struct socket * sock,struct sockaddr * uaddr,int len,int flags)1565 static 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
1623 fail:
1624 release_sock(sk);
1625
1626 return ret;
1627 }
1628
bcm_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1629 static 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
bcm_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)1666 static 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
1673 static 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
1692 static 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
1699 static 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
canbcm_pernet_init(struct net * net)1706 static 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
canbcm_pernet_exit(struct net * net)1716 static 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
1725 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1726 .init = canbcm_pernet_init,
1727 .exit = canbcm_pernet_exit,
1728 };
1729
1730 static struct notifier_block canbcm_notifier = {
1731 .notifier_call = bcm_notifier
1732 };
1733
bcm_module_init(void)1734 static 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
bcm_module_exit(void)1751 static 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
1758 module_init(bcm_module_init);
1759 module_exit(bcm_module_exit);
1760
