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