]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - net/can/bcm.c
Merge remote-tracking branches 'asoc/topic/inntel', 'asoc/topic/input', 'asoc/topic...
[mirror_ubuntu-bionic-kernel.git] / net / can / bcm.c
1 /*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2016 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/interrupt.h>
45 #include <linux/hrtimer.h>
46 #include <linux/list.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49 #include <linux/uio.h>
50 #include <linux/net.h>
51 #include <linux/netdevice.h>
52 #include <linux/socket.h>
53 #include <linux/if_arp.h>
54 #include <linux/skbuff.h>
55 #include <linux/can.h>
56 #include <linux/can/core.h>
57 #include <linux/can/skb.h>
58 #include <linux/can/bcm.h>
59 #include <linux/slab.h>
60 #include <net/sock.h>
61 #include <net/net_namespace.h>
62
63 /*
64 * To send multiple CAN frame content within TX_SETUP or to filter
65 * CAN messages with multiplex index within RX_SETUP, the number of
66 * different filters is limited to 256 due to the one byte index value.
67 */
68 #define MAX_NFRAMES 256
69
70 /* use of last_frames[index].flags */
71 #define RX_RECV 0x40 /* received data for this element */
72 #define RX_THR 0x80 /* element not been sent due to throttle feature */
73 #define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
74
75 /* get best masking value for can_rx_register() for a given single can_id */
76 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
77 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
78 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
79
80 #define CAN_BCM_VERSION "20161123"
81
82 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
83 MODULE_LICENSE("Dual BSD/GPL");
84 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
85 MODULE_ALIAS("can-proto-2");
86
87 /*
88 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
89 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
90 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
91 */
92 static inline u64 get_u64(const struct canfd_frame *cp, int offset)
93 {
94 return *(u64 *)(cp->data + offset);
95 }
96
97 struct bcm_op {
98 struct list_head list;
99 int ifindex;
100 canid_t can_id;
101 u32 flags;
102 unsigned long frames_abs, frames_filtered;
103 struct bcm_timeval ival1, ival2;
104 struct hrtimer timer, thrtimer;
105 struct tasklet_struct tsklet, thrtsklet;
106 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
107 int rx_ifindex;
108 int cfsiz;
109 u32 count;
110 u32 nframes;
111 u32 currframe;
112 /* void pointers to arrays of struct can[fd]_frame */
113 void *frames;
114 void *last_frames;
115 struct canfd_frame sframe;
116 struct canfd_frame last_sframe;
117 struct sock *sk;
118 struct net_device *rx_reg_dev;
119 };
120
121 static struct proc_dir_entry *proc_dir;
122
123 struct bcm_sock {
124 struct sock sk;
125 int bound;
126 int ifindex;
127 struct notifier_block notifier;
128 struct list_head rx_ops;
129 struct list_head tx_ops;
130 unsigned long dropped_usr_msgs;
131 struct proc_dir_entry *bcm_proc_read;
132 char procname [32]; /* inode number in decimal with \0 */
133 };
134
135 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
136 {
137 return (struct bcm_sock *)sk;
138 }
139
140 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
141 {
142 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
143 }
144
145 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
146 #define OPSIZ sizeof(struct bcm_op)
147 #define MHSIZ sizeof(struct bcm_msg_head)
148
149 /*
150 * procfs functions
151 */
152 static char *bcm_proc_getifname(char *result, int ifindex)
153 {
154 struct net_device *dev;
155
156 if (!ifindex)
157 return "any";
158
159 rcu_read_lock();
160 dev = dev_get_by_index_rcu(&init_net, ifindex);
161 if (dev)
162 strcpy(result, dev->name);
163 else
164 strcpy(result, "???");
165 rcu_read_unlock();
166
167 return result;
168 }
169
170 static int bcm_proc_show(struct seq_file *m, void *v)
171 {
172 char ifname[IFNAMSIZ];
173 struct sock *sk = (struct sock *)m->private;
174 struct bcm_sock *bo = bcm_sk(sk);
175 struct bcm_op *op;
176
177 seq_printf(m, ">>> socket %pK", sk->sk_socket);
178 seq_printf(m, " / sk %pK", sk);
179 seq_printf(m, " / bo %pK", bo);
180 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
181 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
182 seq_printf(m, " <<<\n");
183
184 list_for_each_entry(op, &bo->rx_ops, list) {
185
186 unsigned long reduction;
187
188 /* print only active entries & prevent division by zero */
189 if (!op->frames_abs)
190 continue;
191
192 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
193 bcm_proc_getifname(ifname, op->ifindex));
194
195 if (op->flags & CAN_FD_FRAME)
196 seq_printf(m, "(%u)", op->nframes);
197 else
198 seq_printf(m, "[%u]", op->nframes);
199
200 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
201
202 if (op->kt_ival1.tv64)
203 seq_printf(m, "timeo=%lld ",
204 (long long)ktime_to_us(op->kt_ival1));
205
206 if (op->kt_ival2.tv64)
207 seq_printf(m, "thr=%lld ",
208 (long long)ktime_to_us(op->kt_ival2));
209
210 seq_printf(m, "# recv %ld (%ld) => reduction: ",
211 op->frames_filtered, op->frames_abs);
212
213 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
214
215 seq_printf(m, "%s%ld%%\n",
216 (reduction == 100) ? "near " : "", reduction);
217 }
218
219 list_for_each_entry(op, &bo->tx_ops, list) {
220
221 seq_printf(m, "tx_op: %03X %s ", op->can_id,
222 bcm_proc_getifname(ifname, op->ifindex));
223
224 if (op->flags & CAN_FD_FRAME)
225 seq_printf(m, "(%u) ", op->nframes);
226 else
227 seq_printf(m, "[%u] ", op->nframes);
228
229 if (op->kt_ival1.tv64)
230 seq_printf(m, "t1=%lld ",
231 (long long)ktime_to_us(op->kt_ival1));
232
233 if (op->kt_ival2.tv64)
234 seq_printf(m, "t2=%lld ",
235 (long long)ktime_to_us(op->kt_ival2));
236
237 seq_printf(m, "# sent %ld\n", op->frames_abs);
238 }
239 seq_putc(m, '\n');
240 return 0;
241 }
242
243 static int bcm_proc_open(struct inode *inode, struct file *file)
244 {
245 return single_open(file, bcm_proc_show, PDE_DATA(inode));
246 }
247
248 static const struct file_operations bcm_proc_fops = {
249 .owner = THIS_MODULE,
250 .open = bcm_proc_open,
251 .read = seq_read,
252 .llseek = seq_lseek,
253 .release = single_release,
254 };
255
256 /*
257 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
258 * of the given bcm tx op
259 */
260 static void bcm_can_tx(struct bcm_op *op)
261 {
262 struct sk_buff *skb;
263 struct net_device *dev;
264 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
265
266 /* no target device? => exit */
267 if (!op->ifindex)
268 return;
269
270 dev = dev_get_by_index(&init_net, op->ifindex);
271 if (!dev) {
272 /* RFC: should this bcm_op remove itself here? */
273 return;
274 }
275
276 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
277 if (!skb)
278 goto out;
279
280 can_skb_reserve(skb);
281 can_skb_prv(skb)->ifindex = dev->ifindex;
282 can_skb_prv(skb)->skbcnt = 0;
283
284 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz);
285
286 /* send with loopback */
287 skb->dev = dev;
288 can_skb_set_owner(skb, op->sk);
289 can_send(skb, 1);
290
291 /* update statistics */
292 op->currframe++;
293 op->frames_abs++;
294
295 /* reached last frame? */
296 if (op->currframe >= op->nframes)
297 op->currframe = 0;
298 out:
299 dev_put(dev);
300 }
301
302 /*
303 * bcm_send_to_user - send a BCM message to the userspace
304 * (consisting of bcm_msg_head + x CAN frames)
305 */
306 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
307 struct canfd_frame *frames, int has_timestamp)
308 {
309 struct sk_buff *skb;
310 struct canfd_frame *firstframe;
311 struct sockaddr_can *addr;
312 struct sock *sk = op->sk;
313 unsigned int datalen = head->nframes * op->cfsiz;
314 int err;
315
316 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
317 if (!skb)
318 return;
319
320 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
321
322 if (head->nframes) {
323 /* CAN frames starting here */
324 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
325
326 memcpy(skb_put(skb, datalen), frames, datalen);
327
328 /*
329 * the BCM uses the flags-element of the canfd_frame
330 * structure for internal purposes. This is only
331 * relevant for updates that are generated by the
332 * BCM, where nframes is 1
333 */
334 if (head->nframes == 1)
335 firstframe->flags &= BCM_CAN_FLAGS_MASK;
336 }
337
338 if (has_timestamp) {
339 /* restore rx timestamp */
340 skb->tstamp = op->rx_stamp;
341 }
342
343 /*
344 * Put the datagram to the queue so that bcm_recvmsg() can
345 * get it from there. We need to pass the interface index to
346 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
347 * containing the interface index.
348 */
349
350 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
351 addr = (struct sockaddr_can *)skb->cb;
352 memset(addr, 0, sizeof(*addr));
353 addr->can_family = AF_CAN;
354 addr->can_ifindex = op->rx_ifindex;
355
356 err = sock_queue_rcv_skb(sk, skb);
357 if (err < 0) {
358 struct bcm_sock *bo = bcm_sk(sk);
359
360 kfree_skb(skb);
361 /* don't care about overflows in this statistic */
362 bo->dropped_usr_msgs++;
363 }
364 }
365
366 static void bcm_tx_start_timer(struct bcm_op *op)
367 {
368 if (op->kt_ival1.tv64 && op->count)
369 hrtimer_start(&op->timer,
370 ktime_add(ktime_get(), op->kt_ival1),
371 HRTIMER_MODE_ABS);
372 else if (op->kt_ival2.tv64)
373 hrtimer_start(&op->timer,
374 ktime_add(ktime_get(), op->kt_ival2),
375 HRTIMER_MODE_ABS);
376 }
377
378 static void bcm_tx_timeout_tsklet(unsigned long data)
379 {
380 struct bcm_op *op = (struct bcm_op *)data;
381 struct bcm_msg_head msg_head;
382
383 if (op->kt_ival1.tv64 && (op->count > 0)) {
384
385 op->count--;
386 if (!op->count && (op->flags & TX_COUNTEVT)) {
387
388 /* create notification to user */
389 msg_head.opcode = TX_EXPIRED;
390 msg_head.flags = op->flags;
391 msg_head.count = op->count;
392 msg_head.ival1 = op->ival1;
393 msg_head.ival2 = op->ival2;
394 msg_head.can_id = op->can_id;
395 msg_head.nframes = 0;
396
397 bcm_send_to_user(op, &msg_head, NULL, 0);
398 }
399 bcm_can_tx(op);
400
401 } else if (op->kt_ival2.tv64)
402 bcm_can_tx(op);
403
404 bcm_tx_start_timer(op);
405 }
406
407 /*
408 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
409 */
410 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
411 {
412 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
413
414 tasklet_schedule(&op->tsklet);
415
416 return HRTIMER_NORESTART;
417 }
418
419 /*
420 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
421 */
422 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
423 {
424 struct bcm_msg_head head;
425
426 /* update statistics */
427 op->frames_filtered++;
428
429 /* prevent statistics overflow */
430 if (op->frames_filtered > ULONG_MAX/100)
431 op->frames_filtered = op->frames_abs = 0;
432
433 /* this element is not throttled anymore */
434 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
435
436 head.opcode = RX_CHANGED;
437 head.flags = op->flags;
438 head.count = op->count;
439 head.ival1 = op->ival1;
440 head.ival2 = op->ival2;
441 head.can_id = op->can_id;
442 head.nframes = 1;
443
444 bcm_send_to_user(op, &head, data, 1);
445 }
446
447 /*
448 * bcm_rx_update_and_send - process a detected relevant receive content change
449 * 1. update the last received data
450 * 2. send a notification to the user (if possible)
451 */
452 static void bcm_rx_update_and_send(struct bcm_op *op,
453 struct canfd_frame *lastdata,
454 const struct canfd_frame *rxdata)
455 {
456 memcpy(lastdata, rxdata, op->cfsiz);
457
458 /* mark as used and throttled by default */
459 lastdata->flags |= (RX_RECV|RX_THR);
460
461 /* throttling mode inactive ? */
462 if (!op->kt_ival2.tv64) {
463 /* send RX_CHANGED to the user immediately */
464 bcm_rx_changed(op, lastdata);
465 return;
466 }
467
468 /* with active throttling timer we are just done here */
469 if (hrtimer_active(&op->thrtimer))
470 return;
471
472 /* first reception with enabled throttling mode */
473 if (!op->kt_lastmsg.tv64)
474 goto rx_changed_settime;
475
476 /* got a second frame inside a potential throttle period? */
477 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
478 ktime_to_us(op->kt_ival2)) {
479 /* do not send the saved data - only start throttle timer */
480 hrtimer_start(&op->thrtimer,
481 ktime_add(op->kt_lastmsg, op->kt_ival2),
482 HRTIMER_MODE_ABS);
483 return;
484 }
485
486 /* the gap was that big, that throttling was not needed here */
487 rx_changed_settime:
488 bcm_rx_changed(op, lastdata);
489 op->kt_lastmsg = ktime_get();
490 }
491
492 /*
493 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
494 * received data stored in op->last_frames[]
495 */
496 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
497 const struct canfd_frame *rxdata)
498 {
499 struct canfd_frame *cf = op->frames + op->cfsiz * index;
500 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
501 int i;
502
503 /*
504 * no one uses the MSBs of flags for comparison,
505 * so we use it here to detect the first time of reception
506 */
507
508 if (!(lcf->flags & RX_RECV)) {
509 /* received data for the first time => send update to user */
510 bcm_rx_update_and_send(op, lcf, rxdata);
511 return;
512 }
513
514 /* do a real check in CAN frame data section */
515 for (i = 0; i < rxdata->len; i += 8) {
516 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
517 (get_u64(cf, i) & get_u64(lcf, i))) {
518 bcm_rx_update_and_send(op, lcf, rxdata);
519 return;
520 }
521 }
522
523 if (op->flags & RX_CHECK_DLC) {
524 /* do a real check in CAN frame length */
525 if (rxdata->len != lcf->len) {
526 bcm_rx_update_and_send(op, lcf, rxdata);
527 return;
528 }
529 }
530 }
531
532 /*
533 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
534 */
535 static void bcm_rx_starttimer(struct bcm_op *op)
536 {
537 if (op->flags & RX_NO_AUTOTIMER)
538 return;
539
540 if (op->kt_ival1.tv64)
541 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
542 }
543
544 static void bcm_rx_timeout_tsklet(unsigned long data)
545 {
546 struct bcm_op *op = (struct bcm_op *)data;
547 struct bcm_msg_head msg_head;
548
549 /* create notification to user */
550 msg_head.opcode = RX_TIMEOUT;
551 msg_head.flags = op->flags;
552 msg_head.count = op->count;
553 msg_head.ival1 = op->ival1;
554 msg_head.ival2 = op->ival2;
555 msg_head.can_id = op->can_id;
556 msg_head.nframes = 0;
557
558 bcm_send_to_user(op, &msg_head, NULL, 0);
559 }
560
561 /*
562 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
563 */
564 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
565 {
566 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
567
568 /* schedule before NET_RX_SOFTIRQ */
569 tasklet_hi_schedule(&op->tsklet);
570
571 /* no restart of the timer is done here! */
572
573 /* if user wants to be informed, when cyclic CAN-Messages come back */
574 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
575 /* clear received CAN frames to indicate 'nothing received' */
576 memset(op->last_frames, 0, op->nframes * op->cfsiz);
577 }
578
579 return HRTIMER_NORESTART;
580 }
581
582 /*
583 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
584 */
585 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
586 unsigned int index)
587 {
588 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
589
590 if ((op->last_frames) && (lcf->flags & RX_THR)) {
591 if (update)
592 bcm_rx_changed(op, lcf);
593 return 1;
594 }
595 return 0;
596 }
597
598 /*
599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
600 *
601 * update == 0 : just check if throttled data is available (any irq context)
602 * update == 1 : check and send throttled data to userspace (soft_irq context)
603 */
604 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
605 {
606 int updated = 0;
607
608 if (op->nframes > 1) {
609 unsigned int i;
610
611 /* for MUX filter we start at index 1 */
612 for (i = 1; i < op->nframes; i++)
613 updated += bcm_rx_do_flush(op, update, i);
614
615 } else {
616 /* for RX_FILTER_ID and simple filter */
617 updated += bcm_rx_do_flush(op, update, 0);
618 }
619
620 return updated;
621 }
622
623 static void bcm_rx_thr_tsklet(unsigned long data)
624 {
625 struct bcm_op *op = (struct bcm_op *)data;
626
627 /* push the changed data to the userspace */
628 bcm_rx_thr_flush(op, 1);
629 }
630
631 /*
632 * bcm_rx_thr_handler - the time for blocked content updates is over now:
633 * Check for throttled data and send it to the userspace
634 */
635 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
636 {
637 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
638
639 tasklet_schedule(&op->thrtsklet);
640
641 if (bcm_rx_thr_flush(op, 0)) {
642 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
643 return HRTIMER_RESTART;
644 } else {
645 /* rearm throttle handling */
646 op->kt_lastmsg = ktime_set(0, 0);
647 return HRTIMER_NORESTART;
648 }
649 }
650
651 /*
652 * bcm_rx_handler - handle a CAN frame reception
653 */
654 static void bcm_rx_handler(struct sk_buff *skb, void *data)
655 {
656 struct bcm_op *op = (struct bcm_op *)data;
657 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
658 unsigned int i;
659
660 if (op->can_id != rxframe->can_id)
661 return;
662
663 /* make sure to handle the correct frame type (CAN / CAN FD) */
664 if (skb->len != op->cfsiz)
665 return;
666
667 /* disable timeout */
668 hrtimer_cancel(&op->timer);
669
670 /* save rx timestamp */
671 op->rx_stamp = skb->tstamp;
672 /* save originator for recvfrom() */
673 op->rx_ifindex = skb->dev->ifindex;
674 /* update statistics */
675 op->frames_abs++;
676
677 if (op->flags & RX_RTR_FRAME) {
678 /* send reply for RTR-request (placed in op->frames[0]) */
679 bcm_can_tx(op);
680 return;
681 }
682
683 if (op->flags & RX_FILTER_ID) {
684 /* the easiest case */
685 bcm_rx_update_and_send(op, op->last_frames, rxframe);
686 goto rx_starttimer;
687 }
688
689 if (op->nframes == 1) {
690 /* simple compare with index 0 */
691 bcm_rx_cmp_to_index(op, 0, rxframe);
692 goto rx_starttimer;
693 }
694
695 if (op->nframes > 1) {
696 /*
697 * multiplex compare
698 *
699 * find the first multiplex mask that fits.
700 * Remark: The MUX-mask is stored in index 0 - but only the
701 * first 64 bits of the frame data[] are relevant (CAN FD)
702 */
703
704 for (i = 1; i < op->nframes; i++) {
705 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
706 (get_u64(op->frames, 0) &
707 get_u64(op->frames + op->cfsiz * i, 0))) {
708 bcm_rx_cmp_to_index(op, i, rxframe);
709 break;
710 }
711 }
712 }
713
714 rx_starttimer:
715 bcm_rx_starttimer(op);
716 }
717
718 /*
719 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
720 */
721 static struct bcm_op *bcm_find_op(struct list_head *ops,
722 struct bcm_msg_head *mh, int ifindex)
723 {
724 struct bcm_op *op;
725
726 list_for_each_entry(op, ops, list) {
727 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
728 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
729 return op;
730 }
731
732 return NULL;
733 }
734
735 static void bcm_remove_op(struct bcm_op *op)
736 {
737 hrtimer_cancel(&op->timer);
738 hrtimer_cancel(&op->thrtimer);
739
740 if (op->tsklet.func)
741 tasklet_kill(&op->tsklet);
742
743 if (op->thrtsklet.func)
744 tasklet_kill(&op->thrtsklet);
745
746 if ((op->frames) && (op->frames != &op->sframe))
747 kfree(op->frames);
748
749 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
750 kfree(op->last_frames);
751
752 kfree(op);
753 }
754
755 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
756 {
757 if (op->rx_reg_dev == dev) {
758 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
759 bcm_rx_handler, op);
760
761 /* mark as removed subscription */
762 op->rx_reg_dev = NULL;
763 } else
764 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
765 "mismatch %p %p\n", op->rx_reg_dev, dev);
766 }
767
768 /*
769 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
770 */
771 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
772 int ifindex)
773 {
774 struct bcm_op *op, *n;
775
776 list_for_each_entry_safe(op, n, ops, list) {
777 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
778 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
779
780 /*
781 * Don't care if we're bound or not (due to netdev
782 * problems) can_rx_unregister() is always a save
783 * thing to do here.
784 */
785 if (op->ifindex) {
786 /*
787 * Only remove subscriptions that had not
788 * been removed due to NETDEV_UNREGISTER
789 * in bcm_notifier()
790 */
791 if (op->rx_reg_dev) {
792 struct net_device *dev;
793
794 dev = dev_get_by_index(&init_net,
795 op->ifindex);
796 if (dev) {
797 bcm_rx_unreg(dev, op);
798 dev_put(dev);
799 }
800 }
801 } else
802 can_rx_unregister(NULL, op->can_id,
803 REGMASK(op->can_id),
804 bcm_rx_handler, op);
805
806 list_del(&op->list);
807 bcm_remove_op(op);
808 return 1; /* done */
809 }
810 }
811
812 return 0; /* not found */
813 }
814
815 /*
816 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
817 */
818 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
819 int ifindex)
820 {
821 struct bcm_op *op, *n;
822
823 list_for_each_entry_safe(op, n, ops, list) {
824 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
825 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
826 list_del(&op->list);
827 bcm_remove_op(op);
828 return 1; /* done */
829 }
830 }
831
832 return 0; /* not found */
833 }
834
835 /*
836 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
837 */
838 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
839 int ifindex)
840 {
841 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
842
843 if (!op)
844 return -EINVAL;
845
846 /* put current values into msg_head */
847 msg_head->flags = op->flags;
848 msg_head->count = op->count;
849 msg_head->ival1 = op->ival1;
850 msg_head->ival2 = op->ival2;
851 msg_head->nframes = op->nframes;
852
853 bcm_send_to_user(op, msg_head, op->frames, 0);
854
855 return MHSIZ;
856 }
857
858 /*
859 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
860 */
861 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
862 int ifindex, struct sock *sk)
863 {
864 struct bcm_sock *bo = bcm_sk(sk);
865 struct bcm_op *op;
866 struct canfd_frame *cf;
867 unsigned int i;
868 int err;
869
870 /* we need a real device to send frames */
871 if (!ifindex)
872 return -ENODEV;
873
874 /* check nframes boundaries - we need at least one CAN frame */
875 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
876 return -EINVAL;
877
878 /* check the given can_id */
879 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
880 if (op) {
881 /* update existing BCM operation */
882
883 /*
884 * Do we need more space for the CAN frames than currently
885 * allocated? -> This is a _really_ unusual use-case and
886 * therefore (complexity / locking) it is not supported.
887 */
888 if (msg_head->nframes > op->nframes)
889 return -E2BIG;
890
891 /* update CAN frames content */
892 for (i = 0; i < msg_head->nframes; i++) {
893
894 cf = op->frames + op->cfsiz * i;
895 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
896
897 if (op->flags & CAN_FD_FRAME) {
898 if (cf->len > 64)
899 err = -EINVAL;
900 } else {
901 if (cf->len > 8)
902 err = -EINVAL;
903 }
904
905 if (err < 0)
906 return err;
907
908 if (msg_head->flags & TX_CP_CAN_ID) {
909 /* copy can_id into frame */
910 cf->can_id = msg_head->can_id;
911 }
912 }
913 op->flags = msg_head->flags;
914
915 } else {
916 /* insert new BCM operation for the given can_id */
917
918 op = kzalloc(OPSIZ, GFP_KERNEL);
919 if (!op)
920 return -ENOMEM;
921
922 op->can_id = msg_head->can_id;
923 op->cfsiz = CFSIZ(msg_head->flags);
924 op->flags = msg_head->flags;
925
926 /* create array for CAN frames and copy the data */
927 if (msg_head->nframes > 1) {
928 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
929 GFP_KERNEL);
930 if (!op->frames) {
931 kfree(op);
932 return -ENOMEM;
933 }
934 } else
935 op->frames = &op->sframe;
936
937 for (i = 0; i < msg_head->nframes; i++) {
938
939 cf = op->frames + op->cfsiz * i;
940 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
941
942 if (op->flags & CAN_FD_FRAME) {
943 if (cf->len > 64)
944 err = -EINVAL;
945 } else {
946 if (cf->len > 8)
947 err = -EINVAL;
948 }
949
950 if (err < 0) {
951 if (op->frames != &op->sframe)
952 kfree(op->frames);
953 kfree(op);
954 return err;
955 }
956
957 if (msg_head->flags & TX_CP_CAN_ID) {
958 /* copy can_id into frame */
959 cf->can_id = msg_head->can_id;
960 }
961 }
962
963 /* tx_ops never compare with previous received messages */
964 op->last_frames = NULL;
965
966 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
967 op->sk = sk;
968 op->ifindex = ifindex;
969
970 /* initialize uninitialized (kzalloc) structure */
971 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
972 op->timer.function = bcm_tx_timeout_handler;
973
974 /* initialize tasklet for tx countevent notification */
975 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
976 (unsigned long) op);
977
978 /* currently unused in tx_ops */
979 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
980
981 /* add this bcm_op to the list of the tx_ops */
982 list_add(&op->list, &bo->tx_ops);
983
984 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
985
986 if (op->nframes != msg_head->nframes) {
987 op->nframes = msg_head->nframes;
988 /* start multiple frame transmission with index 0 */
989 op->currframe = 0;
990 }
991
992 /* check flags */
993
994 if (op->flags & TX_RESET_MULTI_IDX) {
995 /* start multiple frame transmission with index 0 */
996 op->currframe = 0;
997 }
998
999 if (op->flags & SETTIMER) {
1000 /* set timer values */
1001 op->count = msg_head->count;
1002 op->ival1 = msg_head->ival1;
1003 op->ival2 = msg_head->ival2;
1004 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1005 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1006
1007 /* disable an active timer due to zero values? */
1008 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
1009 hrtimer_cancel(&op->timer);
1010 }
1011
1012 if (op->flags & STARTTIMER) {
1013 hrtimer_cancel(&op->timer);
1014 /* spec: send CAN frame when starting timer */
1015 op->flags |= TX_ANNOUNCE;
1016 }
1017
1018 if (op->flags & TX_ANNOUNCE) {
1019 bcm_can_tx(op);
1020 if (op->count)
1021 op->count--;
1022 }
1023
1024 if (op->flags & STARTTIMER)
1025 bcm_tx_start_timer(op);
1026
1027 return msg_head->nframes * op->cfsiz + MHSIZ;
1028 }
1029
1030 /*
1031 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1032 */
1033 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1034 int ifindex, struct sock *sk)
1035 {
1036 struct bcm_sock *bo = bcm_sk(sk);
1037 struct bcm_op *op;
1038 int do_rx_register;
1039 int err = 0;
1040
1041 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1042 /* be robust against wrong usage ... */
1043 msg_head->flags |= RX_FILTER_ID;
1044 /* ignore trailing garbage */
1045 msg_head->nframes = 0;
1046 }
1047
1048 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1049 if (msg_head->nframes > MAX_NFRAMES + 1)
1050 return -EINVAL;
1051
1052 if ((msg_head->flags & RX_RTR_FRAME) &&
1053 ((msg_head->nframes != 1) ||
1054 (!(msg_head->can_id & CAN_RTR_FLAG))))
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(msg_head->nframes * op->cfsiz,
1101 GFP_KERNEL);
1102 if (!op->frames) {
1103 kfree(op);
1104 return -ENOMEM;
1105 }
1106
1107 /* create and init array for received CAN frames */
1108 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1109 GFP_KERNEL);
1110 if (!op->last_frames) {
1111 kfree(op->frames);
1112 kfree(op);
1113 return -ENOMEM;
1114 }
1115
1116 } else {
1117 op->frames = &op->sframe;
1118 op->last_frames = &op->last_sframe;
1119 }
1120
1121 if (msg_head->nframes) {
1122 err = memcpy_from_msg(op->frames, msg,
1123 msg_head->nframes * op->cfsiz);
1124 if (err < 0) {
1125 if (op->frames != &op->sframe)
1126 kfree(op->frames);
1127 if (op->last_frames != &op->last_sframe)
1128 kfree(op->last_frames);
1129 kfree(op);
1130 return err;
1131 }
1132 }
1133
1134 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1135 op->sk = sk;
1136 op->ifindex = ifindex;
1137
1138 /* ifindex for timeout events w/o previous frame reception */
1139 op->rx_ifindex = ifindex;
1140
1141 /* initialize uninitialized (kzalloc) structure */
1142 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1143 op->timer.function = bcm_rx_timeout_handler;
1144
1145 /* initialize tasklet for rx timeout notification */
1146 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1147 (unsigned long) op);
1148
1149 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1150 op->thrtimer.function = bcm_rx_thr_handler;
1151
1152 /* initialize tasklet for rx throttle handling */
1153 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1154 (unsigned long) op);
1155
1156 /* add this bcm_op to the list of the rx_ops */
1157 list_add(&op->list, &bo->rx_ops);
1158
1159 /* call can_rx_register() */
1160 do_rx_register = 1;
1161
1162 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1163
1164 /* check flags */
1165
1166 if (op->flags & RX_RTR_FRAME) {
1167 struct canfd_frame *frame0 = op->frames;
1168
1169 /* no timers in RTR-mode */
1170 hrtimer_cancel(&op->thrtimer);
1171 hrtimer_cancel(&op->timer);
1172
1173 /*
1174 * funny feature in RX(!)_SETUP only for RTR-mode:
1175 * copy can_id into frame BUT without RTR-flag to
1176 * prevent a full-load-loopback-test ... ;-]
1177 */
1178 if ((op->flags & TX_CP_CAN_ID) ||
1179 (frame0->can_id == op->can_id))
1180 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1181
1182 } else {
1183 if (op->flags & SETTIMER) {
1184
1185 /* set timer value */
1186 op->ival1 = msg_head->ival1;
1187 op->ival2 = msg_head->ival2;
1188 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1189 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1190
1191 /* disable an active timer due to zero value? */
1192 if (!op->kt_ival1.tv64)
1193 hrtimer_cancel(&op->timer);
1194
1195 /*
1196 * In any case cancel the throttle timer, flush
1197 * potentially blocked msgs and reset throttle handling
1198 */
1199 op->kt_lastmsg = ktime_set(0, 0);
1200 hrtimer_cancel(&op->thrtimer);
1201 bcm_rx_thr_flush(op, 1);
1202 }
1203
1204 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1205 hrtimer_start(&op->timer, op->kt_ival1,
1206 HRTIMER_MODE_REL);
1207 }
1208
1209 /* now we can register for can_ids, if we added a new bcm_op */
1210 if (do_rx_register) {
1211 if (ifindex) {
1212 struct net_device *dev;
1213
1214 dev = dev_get_by_index(&init_net, ifindex);
1215 if (dev) {
1216 err = can_rx_register(dev, op->can_id,
1217 REGMASK(op->can_id),
1218 bcm_rx_handler, op,
1219 "bcm");
1220
1221 op->rx_reg_dev = dev;
1222 dev_put(dev);
1223 }
1224
1225 } else
1226 err = can_rx_register(NULL, op->can_id,
1227 REGMASK(op->can_id),
1228 bcm_rx_handler, op, "bcm");
1229 if (err) {
1230 /* this bcm rx op is broken -> remove it */
1231 list_del(&op->list);
1232 bcm_remove_op(op);
1233 return err;
1234 }
1235 }
1236
1237 return msg_head->nframes * op->cfsiz + MHSIZ;
1238 }
1239
1240 /*
1241 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1242 */
1243 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1244 int cfsiz)
1245 {
1246 struct sk_buff *skb;
1247 struct net_device *dev;
1248 int err;
1249
1250 /* we need a real device to send frames */
1251 if (!ifindex)
1252 return -ENODEV;
1253
1254 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1255 if (!skb)
1256 return -ENOMEM;
1257
1258 can_skb_reserve(skb);
1259
1260 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1261 if (err < 0) {
1262 kfree_skb(skb);
1263 return err;
1264 }
1265
1266 dev = dev_get_by_index(&init_net, ifindex);
1267 if (!dev) {
1268 kfree_skb(skb);
1269 return -ENODEV;
1270 }
1271
1272 can_skb_prv(skb)->ifindex = dev->ifindex;
1273 can_skb_prv(skb)->skbcnt = 0;
1274 skb->dev = dev;
1275 can_skb_set_owner(skb, sk);
1276 err = can_send(skb, 1); /* send with loopback */
1277 dev_put(dev);
1278
1279 if (err)
1280 return err;
1281
1282 return cfsiz + MHSIZ;
1283 }
1284
1285 /*
1286 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1287 */
1288 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1289 {
1290 struct sock *sk = sock->sk;
1291 struct bcm_sock *bo = bcm_sk(sk);
1292 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1293 struct bcm_msg_head msg_head;
1294 int cfsiz;
1295 int ret; /* read bytes or error codes as return value */
1296
1297 if (!bo->bound)
1298 return -ENOTCONN;
1299
1300 /* check for valid message length from userspace */
1301 if (size < MHSIZ)
1302 return -EINVAL;
1303
1304 /* read message head information */
1305 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1306 if (ret < 0)
1307 return ret;
1308
1309 cfsiz = CFSIZ(msg_head.flags);
1310 if ((size - MHSIZ) % cfsiz)
1311 return -EINVAL;
1312
1313 /* check for alternative ifindex for this bcm_op */
1314
1315 if (!ifindex && msg->msg_name) {
1316 /* no bound device as default => check msg_name */
1317 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1318
1319 if (msg->msg_namelen < sizeof(*addr))
1320 return -EINVAL;
1321
1322 if (addr->can_family != AF_CAN)
1323 return -EINVAL;
1324
1325 /* ifindex from sendto() */
1326 ifindex = addr->can_ifindex;
1327
1328 if (ifindex) {
1329 struct net_device *dev;
1330
1331 dev = dev_get_by_index(&init_net, ifindex);
1332 if (!dev)
1333 return -ENODEV;
1334
1335 if (dev->type != ARPHRD_CAN) {
1336 dev_put(dev);
1337 return -ENODEV;
1338 }
1339
1340 dev_put(dev);
1341 }
1342 }
1343
1344 lock_sock(sk);
1345
1346 switch (msg_head.opcode) {
1347
1348 case TX_SETUP:
1349 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1350 break;
1351
1352 case RX_SETUP:
1353 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1354 break;
1355
1356 case TX_DELETE:
1357 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1358 ret = MHSIZ;
1359 else
1360 ret = -EINVAL;
1361 break;
1362
1363 case RX_DELETE:
1364 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1365 ret = MHSIZ;
1366 else
1367 ret = -EINVAL;
1368 break;
1369
1370 case TX_READ:
1371 /* reuse msg_head for the reply to TX_READ */
1372 msg_head.opcode = TX_STATUS;
1373 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1374 break;
1375
1376 case RX_READ:
1377 /* reuse msg_head for the reply to RX_READ */
1378 msg_head.opcode = RX_STATUS;
1379 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1380 break;
1381
1382 case TX_SEND:
1383 /* we need exactly one CAN frame behind the msg head */
1384 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1385 ret = -EINVAL;
1386 else
1387 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1388 break;
1389
1390 default:
1391 ret = -EINVAL;
1392 break;
1393 }
1394
1395 release_sock(sk);
1396
1397 return ret;
1398 }
1399
1400 /*
1401 * notification handler for netdevice status changes
1402 */
1403 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1404 void *ptr)
1405 {
1406 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1407 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1408 struct sock *sk = &bo->sk;
1409 struct bcm_op *op;
1410 int notify_enodev = 0;
1411
1412 if (!net_eq(dev_net(dev), &init_net))
1413 return NOTIFY_DONE;
1414
1415 if (dev->type != ARPHRD_CAN)
1416 return NOTIFY_DONE;
1417
1418 switch (msg) {
1419
1420 case NETDEV_UNREGISTER:
1421 lock_sock(sk);
1422
1423 /* remove device specific receive entries */
1424 list_for_each_entry(op, &bo->rx_ops, list)
1425 if (op->rx_reg_dev == dev)
1426 bcm_rx_unreg(dev, op);
1427
1428 /* remove device reference, if this is our bound device */
1429 if (bo->bound && bo->ifindex == dev->ifindex) {
1430 bo->bound = 0;
1431 bo->ifindex = 0;
1432 notify_enodev = 1;
1433 }
1434
1435 release_sock(sk);
1436
1437 if (notify_enodev) {
1438 sk->sk_err = ENODEV;
1439 if (!sock_flag(sk, SOCK_DEAD))
1440 sk->sk_error_report(sk);
1441 }
1442 break;
1443
1444 case NETDEV_DOWN:
1445 if (bo->bound && bo->ifindex == dev->ifindex) {
1446 sk->sk_err = ENETDOWN;
1447 if (!sock_flag(sk, SOCK_DEAD))
1448 sk->sk_error_report(sk);
1449 }
1450 }
1451
1452 return NOTIFY_DONE;
1453 }
1454
1455 /*
1456 * initial settings for all BCM sockets to be set at socket creation time
1457 */
1458 static int bcm_init(struct sock *sk)
1459 {
1460 struct bcm_sock *bo = bcm_sk(sk);
1461
1462 bo->bound = 0;
1463 bo->ifindex = 0;
1464 bo->dropped_usr_msgs = 0;
1465 bo->bcm_proc_read = NULL;
1466
1467 INIT_LIST_HEAD(&bo->tx_ops);
1468 INIT_LIST_HEAD(&bo->rx_ops);
1469
1470 /* set notifier */
1471 bo->notifier.notifier_call = bcm_notifier;
1472
1473 register_netdevice_notifier(&bo->notifier);
1474
1475 return 0;
1476 }
1477
1478 /*
1479 * standard socket functions
1480 */
1481 static int bcm_release(struct socket *sock)
1482 {
1483 struct sock *sk = sock->sk;
1484 struct bcm_sock *bo;
1485 struct bcm_op *op, *next;
1486
1487 if (sk == NULL)
1488 return 0;
1489
1490 bo = bcm_sk(sk);
1491
1492 /* remove bcm_ops, timer, rx_unregister(), etc. */
1493
1494 unregister_netdevice_notifier(&bo->notifier);
1495
1496 lock_sock(sk);
1497
1498 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1499 bcm_remove_op(op);
1500
1501 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1502 /*
1503 * Don't care if we're bound or not (due to netdev problems)
1504 * can_rx_unregister() is always a save thing to do here.
1505 */
1506 if (op->ifindex) {
1507 /*
1508 * Only remove subscriptions that had not
1509 * been removed due to NETDEV_UNREGISTER
1510 * in bcm_notifier()
1511 */
1512 if (op->rx_reg_dev) {
1513 struct net_device *dev;
1514
1515 dev = dev_get_by_index(&init_net, op->ifindex);
1516 if (dev) {
1517 bcm_rx_unreg(dev, op);
1518 dev_put(dev);
1519 }
1520 }
1521 } else
1522 can_rx_unregister(NULL, op->can_id,
1523 REGMASK(op->can_id),
1524 bcm_rx_handler, op);
1525
1526 bcm_remove_op(op);
1527 }
1528
1529 /* remove procfs entry */
1530 if (proc_dir && bo->bcm_proc_read)
1531 remove_proc_entry(bo->procname, proc_dir);
1532
1533 /* remove device reference */
1534 if (bo->bound) {
1535 bo->bound = 0;
1536 bo->ifindex = 0;
1537 }
1538
1539 sock_orphan(sk);
1540 sock->sk = NULL;
1541
1542 release_sock(sk);
1543 sock_put(sk);
1544
1545 return 0;
1546 }
1547
1548 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1549 int flags)
1550 {
1551 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1552 struct sock *sk = sock->sk;
1553 struct bcm_sock *bo = bcm_sk(sk);
1554 int ret = 0;
1555
1556 if (len < sizeof(*addr))
1557 return -EINVAL;
1558
1559 lock_sock(sk);
1560
1561 if (bo->bound) {
1562 ret = -EISCONN;
1563 goto fail;
1564 }
1565
1566 /* bind a device to this socket */
1567 if (addr->can_ifindex) {
1568 struct net_device *dev;
1569
1570 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1571 if (!dev) {
1572 ret = -ENODEV;
1573 goto fail;
1574 }
1575 if (dev->type != ARPHRD_CAN) {
1576 dev_put(dev);
1577 ret = -ENODEV;
1578 goto fail;
1579 }
1580
1581 bo->ifindex = dev->ifindex;
1582 dev_put(dev);
1583
1584 } else {
1585 /* no interface reference for ifindex = 0 ('any' CAN device) */
1586 bo->ifindex = 0;
1587 }
1588
1589 if (proc_dir) {
1590 /* unique socket address as filename */
1591 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1592 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1593 proc_dir,
1594 &bcm_proc_fops, sk);
1595 if (!bo->bcm_proc_read) {
1596 ret = -ENOMEM;
1597 goto fail;
1598 }
1599 }
1600
1601 bo->bound = 1;
1602
1603 fail:
1604 release_sock(sk);
1605
1606 return ret;
1607 }
1608
1609 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1610 int flags)
1611 {
1612 struct sock *sk = sock->sk;
1613 struct sk_buff *skb;
1614 int error = 0;
1615 int noblock;
1616 int err;
1617
1618 noblock = flags & MSG_DONTWAIT;
1619 flags &= ~MSG_DONTWAIT;
1620 skb = skb_recv_datagram(sk, flags, noblock, &error);
1621 if (!skb)
1622 return error;
1623
1624 if (skb->len < size)
1625 size = skb->len;
1626
1627 err = memcpy_to_msg(msg, skb->data, size);
1628 if (err < 0) {
1629 skb_free_datagram(sk, skb);
1630 return err;
1631 }
1632
1633 sock_recv_ts_and_drops(msg, sk, skb);
1634
1635 if (msg->msg_name) {
1636 __sockaddr_check_size(sizeof(struct sockaddr_can));
1637 msg->msg_namelen = sizeof(struct sockaddr_can);
1638 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1639 }
1640
1641 skb_free_datagram(sk, skb);
1642
1643 return size;
1644 }
1645
1646 static const struct proto_ops bcm_ops = {
1647 .family = PF_CAN,
1648 .release = bcm_release,
1649 .bind = sock_no_bind,
1650 .connect = bcm_connect,
1651 .socketpair = sock_no_socketpair,
1652 .accept = sock_no_accept,
1653 .getname = sock_no_getname,
1654 .poll = datagram_poll,
1655 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1656 .listen = sock_no_listen,
1657 .shutdown = sock_no_shutdown,
1658 .setsockopt = sock_no_setsockopt,
1659 .getsockopt = sock_no_getsockopt,
1660 .sendmsg = bcm_sendmsg,
1661 .recvmsg = bcm_recvmsg,
1662 .mmap = sock_no_mmap,
1663 .sendpage = sock_no_sendpage,
1664 };
1665
1666 static struct proto bcm_proto __read_mostly = {
1667 .name = "CAN_BCM",
1668 .owner = THIS_MODULE,
1669 .obj_size = sizeof(struct bcm_sock),
1670 .init = bcm_init,
1671 };
1672
1673 static const struct can_proto bcm_can_proto = {
1674 .type = SOCK_DGRAM,
1675 .protocol = CAN_BCM,
1676 .ops = &bcm_ops,
1677 .prot = &bcm_proto,
1678 };
1679
1680 static int __init bcm_module_init(void)
1681 {
1682 int err;
1683
1684 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1685
1686 err = can_proto_register(&bcm_can_proto);
1687 if (err < 0) {
1688 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1689 return err;
1690 }
1691
1692 /* create /proc/net/can-bcm directory */
1693 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1694 return 0;
1695 }
1696
1697 static void __exit bcm_module_exit(void)
1698 {
1699 can_proto_unregister(&bcm_can_proto);
1700
1701 if (proc_dir)
1702 remove_proc_entry("can-bcm", init_net.proc_net);
1703 }
1704
1705 module_init(bcm_module_init);
1706 module_exit(bcm_module_exit);