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_now(hrtimer, op->kt_ival2);
631 return HRTIMER_RESTART;
632 } else {
633 /* rearm throttle handling */
634 op->kt_lastmsg = 0;
635 return HRTIMER_NORESTART;
636 }
637 }
638
639 /*
640 * bcm_rx_handler - handle a CAN frame reception
641 */
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 (op->flags & CAN_FD_FRAME) {
653 if (!can_is_canfd_skb(skb))
654 return;
655 } else {
656 if (!can_is_can_skb(skb))
657 return;
658 }
659
660 /* disable timeout */
661 hrtimer_cancel(&op->timer);
662
663 /* save rx timestamp */
664 op->rx_stamp = skb->tstamp;
665 /* save originator for recvfrom() */
666 op->rx_ifindex = skb->dev->ifindex;
667 /* update statistics */
668 op->frames_abs++;
669
670 if (op->flags & RX_RTR_FRAME) {
671 /* send reply for RTR-request (placed in op->frames[0]) */
672 bcm_can_tx(op);
673 return;
674 }
675
676 if (op->flags & RX_FILTER_ID) {
677 /* the easiest case */
678 bcm_rx_update_and_send(op, op->last_frames, rxframe);
679 goto rx_starttimer;
680 }
681
682 if (op->nframes == 1) {
683 /* simple compare with index 0 */
684 bcm_rx_cmp_to_index(op, 0, rxframe);
685 goto rx_starttimer;
686 }
687
688 if (op->nframes > 1) {
689 /*
690 * multiplex compare
691 *
692 * find the first multiplex mask that fits.
693 * Remark: The MUX-mask is stored in index 0 - but only the
694 * first 64 bits of the frame data[] are relevant (CAN FD)
695 */
696
697 for (i = 1; i < op->nframes; i++) {
698 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
699 (get_u64(op->frames, 0) &
700 get_u64(op->frames + op->cfsiz * i, 0))) {
701 bcm_rx_cmp_to_index(op, i, rxframe);
702 break;
703 }
704 }
705 }
706
707 rx_starttimer:
708 bcm_rx_starttimer(op);
709 }
710
711 /*
712 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
713 */
bcm_find_op(struct list_head * ops,struct bcm_msg_head * mh,int ifindex)714 static struct bcm_op *bcm_find_op(struct list_head *ops,
715 struct bcm_msg_head *mh, int ifindex)
716 {
717 struct bcm_op *op;
718
719 list_for_each_entry(op, ops, list) {
720 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
721 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
722 return op;
723 }
724
725 return NULL;
726 }
727
bcm_free_op_rcu(struct rcu_head * rcu_head)728 static void bcm_free_op_rcu(struct rcu_head *rcu_head)
729 {
730 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
731
732 if ((op->frames) && (op->frames != &op->sframe))
733 kfree(op->frames);
734
735 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
736 kfree(op->last_frames);
737
738 kfree(op);
739 }
740
bcm_remove_op(struct bcm_op * op)741 static void bcm_remove_op(struct bcm_op *op)
742 {
743 hrtimer_cancel(&op->timer);
744 hrtimer_cancel(&op->thrtimer);
745
746 call_rcu(&op->rcu, bcm_free_op_rcu);
747 }
748
bcm_rx_unreg(struct net_device * dev,struct bcm_op * op)749 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
750 {
751 if (op->rx_reg_dev == dev) {
752 can_rx_unregister(dev_net(dev), dev, op->can_id,
753 REGMASK(op->can_id), bcm_rx_handler, op);
754
755 /* mark as removed subscription */
756 op->rx_reg_dev = NULL;
757 } else
758 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
759 "mismatch %p %p\n", op->rx_reg_dev, dev);
760 }
761
762 /*
763 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
764 */
bcm_delete_rx_op(struct list_head * ops,struct bcm_msg_head * mh,int ifindex)765 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
766 int ifindex)
767 {
768 struct bcm_op *op, *n;
769
770 list_for_each_entry_safe(op, n, ops, list) {
771 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
772 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
773
774 /* disable automatic timer on frame reception */
775 op->flags |= RX_NO_AUTOTIMER;
776
777 /*
778 * Don't care if we're bound or not (due to netdev
779 * problems) can_rx_unregister() is always a save
780 * thing to do here.
781 */
782 if (op->ifindex) {
783 /*
784 * Only remove subscriptions that had not
785 * been removed due to NETDEV_UNREGISTER
786 * in bcm_notifier()
787 */
788 if (op->rx_reg_dev) {
789 struct net_device *dev;
790
791 dev = dev_get_by_index(sock_net(op->sk),
792 op->ifindex);
793 if (dev) {
794 bcm_rx_unreg(dev, op);
795 dev_put(dev);
796 }
797 }
798 } else
799 can_rx_unregister(sock_net(op->sk), NULL,
800 op->can_id,
801 REGMASK(op->can_id),
802 bcm_rx_handler, op);
803
804 list_del(&op->list);
805 bcm_remove_op(op);
806 return 1; /* done */
807 }
808 }
809
810 return 0; /* not found */
811 }
812
813 /*
814 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
815 */
bcm_delete_tx_op(struct list_head * ops,struct bcm_msg_head * mh,int ifindex)816 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
817 int ifindex)
818 {
819 struct bcm_op *op, *n;
820
821 list_for_each_entry_safe(op, n, ops, list) {
822 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
823 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
824 list_del(&op->list);
825 bcm_remove_op(op);
826 return 1; /* done */
827 }
828 }
829
830 return 0; /* not found */
831 }
832
833 /*
834 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
835 */
bcm_read_op(struct list_head * ops,struct bcm_msg_head * msg_head,int ifindex)836 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
837 int ifindex)
838 {
839 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
840
841 if (!op)
842 return -EINVAL;
843
844 /* put current values into msg_head */
845 msg_head->flags = op->flags;
846 msg_head->count = op->count;
847 msg_head->ival1 = op->ival1;
848 msg_head->ival2 = op->ival2;
849 msg_head->nframes = op->nframes;
850
851 bcm_send_to_user(op, msg_head, op->frames, 0);
852
853 return MHSIZ;
854 }
855
856 /*
857 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
858 */
bcm_tx_setup(struct bcm_msg_head * msg_head,struct msghdr * msg,int ifindex,struct sock * sk)859 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
860 int ifindex, struct sock *sk)
861 {
862 struct bcm_sock *bo = bcm_sk(sk);
863 struct bcm_op *op;
864 struct canfd_frame *cf;
865 unsigned int i;
866 int err;
867
868 /* we need a real device to send frames */
869 if (!ifindex)
870 return -ENODEV;
871
872 /* check nframes boundaries - we need at least one CAN frame */
873 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
874 return -EINVAL;
875
876 /* check timeval limitations */
877 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
878 return -EINVAL;
879
880 /* check the given can_id */
881 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
882 if (op) {
883 /* update existing BCM operation */
884
885 /*
886 * Do we need more space for the CAN frames than currently
887 * allocated? -> This is a _really_ unusual use-case and
888 * therefore (complexity / locking) it is not supported.
889 */
890 if (msg_head->nframes > op->nframes)
891 return -E2BIG;
892
893 /* update CAN frames content */
894 for (i = 0; i < msg_head->nframes; i++) {
895
896 cf = op->frames + op->cfsiz * i;
897 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
898
899 if (op->flags & CAN_FD_FRAME) {
900 if (cf->len > 64)
901 err = -EINVAL;
902 } else {
903 if (cf->len > 8)
904 err = -EINVAL;
905 }
906
907 if (err < 0)
908 return err;
909
910 if (msg_head->flags & TX_CP_CAN_ID) {
911 /* copy can_id into frame */
912 cf->can_id = msg_head->can_id;
913 }
914 }
915 op->flags = msg_head->flags;
916
917 } else {
918 /* insert new BCM operation for the given can_id */
919
920 op = kzalloc(OPSIZ, GFP_KERNEL);
921 if (!op)
922 return -ENOMEM;
923
924 op->can_id = msg_head->can_id;
925 op->cfsiz = CFSIZ(msg_head->flags);
926 op->flags = msg_head->flags;
927
928 /* create array for CAN frames and copy the data */
929 if (msg_head->nframes > 1) {
930 op->frames = kmalloc_array(msg_head->nframes,
931 op->cfsiz,
932 GFP_KERNEL);
933 if (!op->frames) {
934 kfree(op);
935 return -ENOMEM;
936 }
937 } else
938 op->frames = &op->sframe;
939
940 for (i = 0; i < msg_head->nframes; i++) {
941
942 cf = op->frames + op->cfsiz * i;
943 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
944 if (err < 0)
945 goto free_op;
946
947 if (op->flags & CAN_FD_FRAME) {
948 if (cf->len > 64)
949 err = -EINVAL;
950 } else {
951 if (cf->len > 8)
952 err = -EINVAL;
953 }
954
955 if (err < 0)
956 goto free_op;
957
958 if (msg_head->flags & TX_CP_CAN_ID) {
959 /* copy can_id into frame */
960 cf->can_id = msg_head->can_id;
961 }
962 }
963
964 /* tx_ops never compare with previous received messages */
965 op->last_frames = NULL;
966
967 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
968 op->sk = sk;
969 op->ifindex = ifindex;
970
971 /* initialize uninitialized (kzalloc) structure */
972 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
973 HRTIMER_MODE_REL_SOFT);
974 op->timer.function = bcm_tx_timeout_handler;
975
976 /* currently unused in tx_ops */
977 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
978 HRTIMER_MODE_REL_SOFT);
979
980 /* add this bcm_op to the list of the tx_ops */
981 list_add(&op->list, &bo->tx_ops);
982
983 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
984
985 if (op->nframes != msg_head->nframes) {
986 op->nframes = msg_head->nframes;
987 /* start multiple frame transmission with index 0 */
988 op->currframe = 0;
989 }
990
991 /* check flags */
992
993 if (op->flags & TX_RESET_MULTI_IDX) {
994 /* start multiple frame transmission with index 0 */
995 op->currframe = 0;
996 }
997
998 if (op->flags & SETTIMER) {
999 /* set timer values */
1000 op->count = msg_head->count;
1001 op->ival1 = msg_head->ival1;
1002 op->ival2 = msg_head->ival2;
1003 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1004 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1005
1006 /* disable an active timer due to zero values? */
1007 if (!op->kt_ival1 && !op->kt_ival2)
1008 hrtimer_cancel(&op->timer);
1009 }
1010
1011 if (op->flags & STARTTIMER) {
1012 hrtimer_cancel(&op->timer);
1013 /* spec: send CAN frame when starting timer */
1014 op->flags |= TX_ANNOUNCE;
1015 }
1016
1017 if (op->flags & TX_ANNOUNCE) {
1018 bcm_can_tx(op);
1019 if (op->count)
1020 op->count--;
1021 }
1022
1023 if (op->flags & STARTTIMER)
1024 bcm_tx_start_timer(op);
1025
1026 return msg_head->nframes * op->cfsiz + MHSIZ;
1027
1028 free_op:
1029 if (op->frames != &op->sframe)
1030 kfree(op->frames);
1031 kfree(op);
1032 return err;
1033 }
1034
1035 /*
1036 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1037 */
bcm_rx_setup(struct bcm_msg_head * msg_head,struct msghdr * msg,int ifindex,struct sock * sk)1038 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1039 int ifindex, struct sock *sk)
1040 {
1041 struct bcm_sock *bo = bcm_sk(sk);
1042 struct bcm_op *op;
1043 int do_rx_register;
1044 int err = 0;
1045
1046 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1047 /* be robust against wrong usage ... */
1048 msg_head->flags |= RX_FILTER_ID;
1049 /* ignore trailing garbage */
1050 msg_head->nframes = 0;
1051 }
1052
1053 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1054 if (msg_head->nframes > MAX_NFRAMES + 1)
1055 return -EINVAL;
1056
1057 if ((msg_head->flags & RX_RTR_FRAME) &&
1058 ((msg_head->nframes != 1) ||
1059 (!(msg_head->can_id & CAN_RTR_FLAG))))
1060 return -EINVAL;
1061
1062 /* check timeval limitations */
1063 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1064 return -EINVAL;
1065
1066 /* check the given can_id */
1067 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1068 if (op) {
1069 /* update existing BCM operation */
1070
1071 /*
1072 * Do we need more space for the CAN frames than currently
1073 * allocated? -> This is a _really_ unusual use-case and
1074 * therefore (complexity / locking) it is not supported.
1075 */
1076 if (msg_head->nframes > op->nframes)
1077 return -E2BIG;
1078
1079 if (msg_head->nframes) {
1080 /* update CAN frames content */
1081 err = memcpy_from_msg(op->frames, msg,
1082 msg_head->nframes * op->cfsiz);
1083 if (err < 0)
1084 return err;
1085
1086 /* clear last_frames to indicate 'nothing received' */
1087 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1088 }
1089
1090 op->nframes = msg_head->nframes;
1091 op->flags = msg_head->flags;
1092
1093 /* Only an update -> do not call can_rx_register() */
1094 do_rx_register = 0;
1095
1096 } else {
1097 /* insert new BCM operation for the given can_id */
1098 op = kzalloc(OPSIZ, GFP_KERNEL);
1099 if (!op)
1100 return -ENOMEM;
1101
1102 op->can_id = msg_head->can_id;
1103 op->nframes = msg_head->nframes;
1104 op->cfsiz = CFSIZ(msg_head->flags);
1105 op->flags = msg_head->flags;
1106
1107 if (msg_head->nframes > 1) {
1108 /* create array for CAN frames and copy the data */
1109 op->frames = kmalloc_array(msg_head->nframes,
1110 op->cfsiz,
1111 GFP_KERNEL);
1112 if (!op->frames) {
1113 kfree(op);
1114 return -ENOMEM;
1115 }
1116
1117 /* create and init array for received CAN frames */
1118 op->last_frames = kcalloc(msg_head->nframes,
1119 op->cfsiz,
1120 GFP_KERNEL);
1121 if (!op->last_frames) {
1122 kfree(op->frames);
1123 kfree(op);
1124 return -ENOMEM;
1125 }
1126
1127 } else {
1128 op->frames = &op->sframe;
1129 op->last_frames = &op->last_sframe;
1130 }
1131
1132 if (msg_head->nframes) {
1133 err = memcpy_from_msg(op->frames, msg,
1134 msg_head->nframes * op->cfsiz);
1135 if (err < 0) {
1136 if (op->frames != &op->sframe)
1137 kfree(op->frames);
1138 if (op->last_frames != &op->last_sframe)
1139 kfree(op->last_frames);
1140 kfree(op);
1141 return err;
1142 }
1143 }
1144
1145 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1146 op->sk = sk;
1147 op->ifindex = ifindex;
1148
1149 /* ifindex for timeout events w/o previous frame reception */
1150 op->rx_ifindex = ifindex;
1151
1152 /* initialize uninitialized (kzalloc) structure */
1153 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1154 HRTIMER_MODE_REL_SOFT);
1155 op->timer.function = bcm_rx_timeout_handler;
1156
1157 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1158 HRTIMER_MODE_REL_SOFT);
1159 op->thrtimer.function = bcm_rx_thr_handler;
1160
1161 /* add this bcm_op to the list of the rx_ops */
1162 list_add(&op->list, &bo->rx_ops);
1163
1164 /* call can_rx_register() */
1165 do_rx_register = 1;
1166
1167 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1168
1169 /* check flags */
1170
1171 if (op->flags & RX_RTR_FRAME) {
1172 struct canfd_frame *frame0 = op->frames;
1173
1174 /* no timers in RTR-mode */
1175 hrtimer_cancel(&op->thrtimer);
1176 hrtimer_cancel(&op->timer);
1177
1178 /*
1179 * funny feature in RX(!)_SETUP only for RTR-mode:
1180 * copy can_id into frame BUT without RTR-flag to
1181 * prevent a full-load-loopback-test ... ;-]
1182 */
1183 if ((op->flags & TX_CP_CAN_ID) ||
1184 (frame0->can_id == op->can_id))
1185 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1186
1187 } else {
1188 if (op->flags & SETTIMER) {
1189
1190 /* set timer value */
1191 op->ival1 = msg_head->ival1;
1192 op->ival2 = msg_head->ival2;
1193 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1194 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1195
1196 /* disable an active timer due to zero value? */
1197 if (!op->kt_ival1)
1198 hrtimer_cancel(&op->timer);
1199
1200 /*
1201 * In any case cancel the throttle timer, flush
1202 * potentially blocked msgs and reset throttle handling
1203 */
1204 op->kt_lastmsg = 0;
1205 hrtimer_cancel(&op->thrtimer);
1206 bcm_rx_thr_flush(op);
1207 }
1208
1209 if ((op->flags & STARTTIMER) && op->kt_ival1)
1210 hrtimer_start(&op->timer, op->kt_ival1,
1211 HRTIMER_MODE_REL_SOFT);
1212 }
1213
1214 /* now we can register for can_ids, if we added a new bcm_op */
1215 if (do_rx_register) {
1216 if (ifindex) {
1217 struct net_device *dev;
1218
1219 dev = dev_get_by_index(sock_net(sk), ifindex);
1220 if (dev) {
1221 err = can_rx_register(sock_net(sk), dev,
1222 op->can_id,
1223 REGMASK(op->can_id),
1224 bcm_rx_handler, op,
1225 "bcm", sk);
1226
1227 op->rx_reg_dev = dev;
1228 dev_put(dev);
1229 }
1230
1231 } else
1232 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1233 REGMASK(op->can_id),
1234 bcm_rx_handler, op, "bcm", sk);
1235 if (err) {
1236 /* this bcm rx op is broken -> remove it */
1237 list_del(&op->list);
1238 bcm_remove_op(op);
1239 return err;
1240 }
1241 }
1242
1243 return msg_head->nframes * op->cfsiz + MHSIZ;
1244 }
1245
1246 /*
1247 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1248 */
bcm_tx_send(struct msghdr * msg,int ifindex,struct sock * sk,int cfsiz)1249 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1250 int cfsiz)
1251 {
1252 struct sk_buff *skb;
1253 struct net_device *dev;
1254 int err;
1255
1256 /* we need a real device to send frames */
1257 if (!ifindex)
1258 return -ENODEV;
1259
1260 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1261 if (!skb)
1262 return -ENOMEM;
1263
1264 can_skb_reserve(skb);
1265
1266 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1267 if (err < 0) {
1268 kfree_skb(skb);
1269 return err;
1270 }
1271
1272 dev = dev_get_by_index(sock_net(sk), ifindex);
1273 if (!dev) {
1274 kfree_skb(skb);
1275 return -ENODEV;
1276 }
1277
1278 can_skb_prv(skb)->ifindex = dev->ifindex;
1279 can_skb_prv(skb)->skbcnt = 0;
1280 skb->dev = dev;
1281 can_skb_set_owner(skb, sk);
1282 err = can_send(skb, 1); /* send with loopback */
1283 dev_put(dev);
1284
1285 if (err)
1286 return err;
1287
1288 return cfsiz + MHSIZ;
1289 }
1290
1291 /*
1292 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1293 */
bcm_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)1294 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1295 {
1296 struct sock *sk = sock->sk;
1297 struct bcm_sock *bo = bcm_sk(sk);
1298 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1299 struct bcm_msg_head msg_head;
1300 int cfsiz;
1301 int ret; /* read bytes or error codes as return value */
1302
1303 if (!bo->bound)
1304 return -ENOTCONN;
1305
1306 /* check for valid message length from userspace */
1307 if (size < MHSIZ)
1308 return -EINVAL;
1309
1310 /* read message head information */
1311 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1312 if (ret < 0)
1313 return ret;
1314
1315 cfsiz = CFSIZ(msg_head.flags);
1316 if ((size - MHSIZ) % cfsiz)
1317 return -EINVAL;
1318
1319 /* check for alternative ifindex for this bcm_op */
1320
1321 if (!ifindex && msg->msg_name) {
1322 /* no bound device as default => check msg_name */
1323 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1324
1325 if (msg->msg_namelen < BCM_MIN_NAMELEN)
1326 return -EINVAL;
1327
1328 if (addr->can_family != AF_CAN)
1329 return -EINVAL;
1330
1331 /* ifindex from sendto() */
1332 ifindex = addr->can_ifindex;
1333
1334 if (ifindex) {
1335 struct net_device *dev;
1336
1337 dev = dev_get_by_index(sock_net(sk), ifindex);
1338 if (!dev)
1339 return -ENODEV;
1340
1341 if (dev->type != ARPHRD_CAN) {
1342 dev_put(dev);
1343 return -ENODEV;
1344 }
1345
1346 dev_put(dev);
1347 }
1348 }
1349
1350 lock_sock(sk);
1351
1352 switch (msg_head.opcode) {
1353
1354 case TX_SETUP:
1355 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1356 break;
1357
1358 case RX_SETUP:
1359 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1360 break;
1361
1362 case TX_DELETE:
1363 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1364 ret = MHSIZ;
1365 else
1366 ret = -EINVAL;
1367 break;
1368
1369 case RX_DELETE:
1370 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1371 ret = MHSIZ;
1372 else
1373 ret = -EINVAL;
1374 break;
1375
1376 case TX_READ:
1377 /* reuse msg_head for the reply to TX_READ */
1378 msg_head.opcode = TX_STATUS;
1379 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1380 break;
1381
1382 case RX_READ:
1383 /* reuse msg_head for the reply to RX_READ */
1384 msg_head.opcode = RX_STATUS;
1385 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1386 break;
1387
1388 case TX_SEND:
1389 /* we need exactly one CAN frame behind the msg head */
1390 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1391 ret = -EINVAL;
1392 else
1393 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1394 break;
1395
1396 default:
1397 ret = -EINVAL;
1398 break;
1399 }
1400
1401 release_sock(sk);
1402
1403 return ret;
1404 }
1405
1406 /*
1407 * notification handler for netdevice status changes
1408 */
bcm_notify(struct bcm_sock * bo,unsigned long msg,struct net_device * dev)1409 static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1410 struct net_device *dev)
1411 {
1412 struct sock *sk = &bo->sk;
1413 struct bcm_op *op;
1414 int notify_enodev = 0;
1415
1416 if (!net_eq(dev_net(dev), sock_net(sk)))
1417 return;
1418
1419 switch (msg) {
1420
1421 case NETDEV_UNREGISTER:
1422 lock_sock(sk);
1423
1424 /* remove device specific receive entries */
1425 list_for_each_entry(op, &bo->rx_ops, list)
1426 if (op->rx_reg_dev == dev)
1427 bcm_rx_unreg(dev, op);
1428
1429 /* remove device reference, if this is our bound device */
1430 if (bo->bound && bo->ifindex == dev->ifindex) {
1431 bo->bound = 0;
1432 bo->ifindex = 0;
1433 notify_enodev = 1;
1434 }
1435
1436 release_sock(sk);
1437
1438 if (notify_enodev) {
1439 sk->sk_err = ENODEV;
1440 if (!sock_flag(sk, SOCK_DEAD))
1441 sk_error_report(sk);
1442 }
1443 break;
1444
1445 case NETDEV_DOWN:
1446 if (bo->bound && bo->ifindex == dev->ifindex) {
1447 sk->sk_err = ENETDOWN;
1448 if (!sock_flag(sk, SOCK_DEAD))
1449 sk_error_report(sk);
1450 }
1451 }
1452 }
1453
bcm_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)1454 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1455 void *ptr)
1456 {
1457 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1458
1459 if (dev->type != ARPHRD_CAN)
1460 return NOTIFY_DONE;
1461 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1462 return NOTIFY_DONE;
1463 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1464 return NOTIFY_DONE;
1465
1466 spin_lock(&bcm_notifier_lock);
1467 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1468 spin_unlock(&bcm_notifier_lock);
1469 bcm_notify(bcm_busy_notifier, msg, dev);
1470 spin_lock(&bcm_notifier_lock);
1471 }
1472 bcm_busy_notifier = NULL;
1473 spin_unlock(&bcm_notifier_lock);
1474 return NOTIFY_DONE;
1475 }
1476
1477 /*
1478 * initial settings for all BCM sockets to be set at socket creation time
1479 */
bcm_init(struct sock * sk)1480 static int bcm_init(struct sock *sk)
1481 {
1482 struct bcm_sock *bo = bcm_sk(sk);
1483
1484 bo->bound = 0;
1485 bo->ifindex = 0;
1486 bo->dropped_usr_msgs = 0;
1487 bo->bcm_proc_read = NULL;
1488
1489 INIT_LIST_HEAD(&bo->tx_ops);
1490 INIT_LIST_HEAD(&bo->rx_ops);
1491
1492 /* set notifier */
1493 spin_lock(&bcm_notifier_lock);
1494 list_add_tail(&bo->notifier, &bcm_notifier_list);
1495 spin_unlock(&bcm_notifier_lock);
1496
1497 return 0;
1498 }
1499
1500 /*
1501 * standard socket functions
1502 */
bcm_release(struct socket * sock)1503 static int bcm_release(struct socket *sock)
1504 {
1505 struct sock *sk = sock->sk;
1506 struct net *net;
1507 struct bcm_sock *bo;
1508 struct bcm_op *op, *next;
1509
1510 if (!sk)
1511 return 0;
1512
1513 net = sock_net(sk);
1514 bo = bcm_sk(sk);
1515
1516 /* remove bcm_ops, timer, rx_unregister(), etc. */
1517
1518 spin_lock(&bcm_notifier_lock);
1519 while (bcm_busy_notifier == bo) {
1520 spin_unlock(&bcm_notifier_lock);
1521 schedule_timeout_uninterruptible(1);
1522 spin_lock(&bcm_notifier_lock);
1523 }
1524 list_del(&bo->notifier);
1525 spin_unlock(&bcm_notifier_lock);
1526
1527 lock_sock(sk);
1528
1529 #if IS_ENABLED(CONFIG_PROC_FS)
1530 /* remove procfs entry */
1531 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1532 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1533 #endif /* CONFIG_PROC_FS */
1534
1535 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1536 bcm_remove_op(op);
1537
1538 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1539 /*
1540 * Don't care if we're bound or not (due to netdev problems)
1541 * can_rx_unregister() is always a save thing to do here.
1542 */
1543 if (op->ifindex) {
1544 /*
1545 * Only remove subscriptions that had not
1546 * been removed due to NETDEV_UNREGISTER
1547 * in bcm_notifier()
1548 */
1549 if (op->rx_reg_dev) {
1550 struct net_device *dev;
1551
1552 dev = dev_get_by_index(net, op->ifindex);
1553 if (dev) {
1554 bcm_rx_unreg(dev, op);
1555 dev_put(dev);
1556 }
1557 }
1558 } else
1559 can_rx_unregister(net, NULL, op->can_id,
1560 REGMASK(op->can_id),
1561 bcm_rx_handler, op);
1562
1563 }
1564
1565 synchronize_rcu();
1566
1567 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1568 bcm_remove_op(op);
1569
1570 /* remove device reference */
1571 if (bo->bound) {
1572 bo->bound = 0;
1573 bo->ifindex = 0;
1574 }
1575
1576 sock_orphan(sk);
1577 sock->sk = NULL;
1578
1579 release_sock(sk);
1580 sock_put(sk);
1581
1582 return 0;
1583 }
1584
bcm_connect(struct socket * sock,struct sockaddr * uaddr,int len,int flags)1585 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1586 int flags)
1587 {
1588 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1589 struct sock *sk = sock->sk;
1590 struct bcm_sock *bo = bcm_sk(sk);
1591 struct net *net = sock_net(sk);
1592 int ret = 0;
1593
1594 if (len < BCM_MIN_NAMELEN)
1595 return -EINVAL;
1596
1597 lock_sock(sk);
1598
1599 if (bo->bound) {
1600 ret = -EISCONN;
1601 goto fail;
1602 }
1603
1604 /* bind a device to this socket */
1605 if (addr->can_ifindex) {
1606 struct net_device *dev;
1607
1608 dev = dev_get_by_index(net, addr->can_ifindex);
1609 if (!dev) {
1610 ret = -ENODEV;
1611 goto fail;
1612 }
1613 if (dev->type != ARPHRD_CAN) {
1614 dev_put(dev);
1615 ret = -ENODEV;
1616 goto fail;
1617 }
1618
1619 bo->ifindex = dev->ifindex;
1620 dev_put(dev);
1621
1622 } else {
1623 /* no interface reference for ifindex = 0 ('any' CAN device) */
1624 bo->ifindex = 0;
1625 }
1626
1627 #if IS_ENABLED(CONFIG_PROC_FS)
1628 if (net->can.bcmproc_dir) {
1629 /* unique socket address as filename */
1630 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1631 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1632 net->can.bcmproc_dir,
1633 bcm_proc_show, sk);
1634 if (!bo->bcm_proc_read) {
1635 ret = -ENOMEM;
1636 goto fail;
1637 }
1638 }
1639 #endif /* CONFIG_PROC_FS */
1640
1641 bo->bound = 1;
1642
1643 fail:
1644 release_sock(sk);
1645
1646 return ret;
1647 }
1648
bcm_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1649 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1650 int flags)
1651 {
1652 struct sock *sk = sock->sk;
1653 struct sk_buff *skb;
1654 int error = 0;
1655 int err;
1656
1657 skb = skb_recv_datagram(sk, flags, &error);
1658 if (!skb)
1659 return error;
1660
1661 if (skb->len < size)
1662 size = skb->len;
1663
1664 err = memcpy_to_msg(msg, skb->data, size);
1665 if (err < 0) {
1666 skb_free_datagram(sk, skb);
1667 return err;
1668 }
1669
1670 sock_recv_cmsgs(msg, sk, skb);
1671
1672 if (msg->msg_name) {
1673 __sockaddr_check_size(BCM_MIN_NAMELEN);
1674 msg->msg_namelen = BCM_MIN_NAMELEN;
1675 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1676 }
1677
1678 skb_free_datagram(sk, skb);
1679
1680 return size;
1681 }
1682
bcm_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)1683 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1684 unsigned long arg)
1685 {
1686 /* no ioctls for socket layer -> hand it down to NIC layer */
1687 return -ENOIOCTLCMD;
1688 }
1689
1690 static const struct proto_ops bcm_ops = {
1691 .family = PF_CAN,
1692 .release = bcm_release,
1693 .bind = sock_no_bind,
1694 .connect = bcm_connect,
1695 .socketpair = sock_no_socketpair,
1696 .accept = sock_no_accept,
1697 .getname = sock_no_getname,
1698 .poll = datagram_poll,
1699 .ioctl = bcm_sock_no_ioctlcmd,
1700 .gettstamp = sock_gettstamp,
1701 .listen = sock_no_listen,
1702 .shutdown = sock_no_shutdown,
1703 .sendmsg = bcm_sendmsg,
1704 .recvmsg = bcm_recvmsg,
1705 .mmap = sock_no_mmap,
1706 };
1707
1708 static struct proto bcm_proto __read_mostly = {
1709 .name = "CAN_BCM",
1710 .owner = THIS_MODULE,
1711 .obj_size = sizeof(struct bcm_sock),
1712 .init = bcm_init,
1713 };
1714
1715 static const struct can_proto bcm_can_proto = {
1716 .type = SOCK_DGRAM,
1717 .protocol = CAN_BCM,
1718 .ops = &bcm_ops,
1719 .prot = &bcm_proto,
1720 };
1721
canbcm_pernet_init(struct net * net)1722 static int canbcm_pernet_init(struct net *net)
1723 {
1724 #if IS_ENABLED(CONFIG_PROC_FS)
1725 /* create /proc/net/can-bcm directory */
1726 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1727 #endif /* CONFIG_PROC_FS */
1728
1729 return 0;
1730 }
1731
canbcm_pernet_exit(struct net * net)1732 static void canbcm_pernet_exit(struct net *net)
1733 {
1734 #if IS_ENABLED(CONFIG_PROC_FS)
1735 /* remove /proc/net/can-bcm directory */
1736 if (net->can.bcmproc_dir)
1737 remove_proc_entry("can-bcm", net->proc_net);
1738 #endif /* CONFIG_PROC_FS */
1739 }
1740
1741 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1742 .init = canbcm_pernet_init,
1743 .exit = canbcm_pernet_exit,
1744 };
1745
1746 static struct notifier_block canbcm_notifier = {
1747 .notifier_call = bcm_notifier
1748 };
1749
bcm_module_init(void)1750 static int __init bcm_module_init(void)
1751 {
1752 int err;
1753
1754 pr_info("can: broadcast manager protocol\n");
1755
1756 err = register_pernet_subsys(&canbcm_pernet_ops);
1757 if (err)
1758 return err;
1759
1760 err = register_netdevice_notifier(&canbcm_notifier);
1761 if (err)
1762 goto register_notifier_failed;
1763
1764 err = can_proto_register(&bcm_can_proto);
1765 if (err < 0) {
1766 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1767 goto register_proto_failed;
1768 }
1769
1770 return 0;
1771
1772 register_proto_failed:
1773 unregister_netdevice_notifier(&canbcm_notifier);
1774 register_notifier_failed:
1775 unregister_pernet_subsys(&canbcm_pernet_ops);
1776 return err;
1777 }
1778
bcm_module_exit(void)1779 static void __exit bcm_module_exit(void)
1780 {
1781 can_proto_unregister(&bcm_can_proto);
1782 unregister_netdevice_notifier(&canbcm_notifier);
1783 unregister_pernet_subsys(&canbcm_pernet_ops);
1784 }
1785
1786 module_init(bcm_module_init);
1787 module_exit(bcm_module_exit);
1788