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1/*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2007 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/bcm.h>
58#include <linux/slab.h>
59#include <net/sock.h>
60#include <net/net_namespace.h>
61
62/*
63 * To send multiple CAN frame content within TX_SETUP or to filter
64 * CAN messages with multiplex index within RX_SETUP, the number of
65 * different filters is limited to 256 due to the one byte index value.
66 */
67#define MAX_NFRAMES 256
68
69/* use of last_frames[index].can_dlc */
70#define RX_RECV 0x40 /* received data for this element */
71#define RX_THR 0x80 /* element not been sent due to throttle feature */
72#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
73
74/* get best masking value for can_rx_register() for a given single can_id */
75#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
76 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
77 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
78
79#define CAN_BCM_VERSION CAN_VERSION
80static __initdata const char banner[] = KERN_INFO
81 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
82
83MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
84MODULE_LICENSE("Dual BSD/GPL");
85MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
86MODULE_ALIAS("can-proto-2");
87
88/* easy access to can_frame payload */
89static inline u64 GET_U64(const struct can_frame *cp)
90{
91 return *(u64 *)cp->data;
92}
93
94struct bcm_op {
95 struct list_head list;
96 int ifindex;
97 canid_t can_id;
98 u32 flags;
99 unsigned long frames_abs, frames_filtered;
100 struct timeval ival1, ival2;
101 struct hrtimer timer, thrtimer;
102 struct tasklet_struct tsklet, thrtsklet;
103 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
104 int rx_ifindex;
105 u32 count;
106 u32 nframes;
107 u32 currframe;
108 struct can_frame *frames;
109 struct can_frame *last_frames;
110 struct can_frame sframe;
111 struct can_frame last_sframe;
112 struct sock *sk;
113 struct net_device *rx_reg_dev;
114};
115
116static struct proc_dir_entry *proc_dir;
117
118struct bcm_sock {
119 struct sock sk;
120 int bound;
121 int ifindex;
122 struct notifier_block notifier;
123 struct list_head rx_ops;
124 struct list_head tx_ops;
125 unsigned long dropped_usr_msgs;
126 struct proc_dir_entry *bcm_proc_read;
127 char procname [32]; /* inode number in decimal with \0 */
128};
129
130static inline struct bcm_sock *bcm_sk(const struct sock *sk)
131{
132 return (struct bcm_sock *)sk;
133}
134
135#define CFSIZ sizeof(struct can_frame)
136#define OPSIZ sizeof(struct bcm_op)
137#define MHSIZ sizeof(struct bcm_msg_head)
138
139/*
140 * procfs functions
141 */
142static char *bcm_proc_getifname(char *result, int ifindex)
143{
144 struct net_device *dev;
145
146 if (!ifindex)
147 return "any";
148
149 rcu_read_lock();
150 dev = dev_get_by_index_rcu(&init_net, ifindex);
151 if (dev)
152 strcpy(result, dev->name);
153 else
154 strcpy(result, "???");
155 rcu_read_unlock();
156
157 return result;
158}
159
160static int bcm_proc_show(struct seq_file *m, void *v)
161{
162 char ifname[IFNAMSIZ];
163 struct sock *sk = (struct sock *)m->private;
164 struct bcm_sock *bo = bcm_sk(sk);
165 struct bcm_op *op;
166
167 seq_printf(m, ">>> socket %pK", sk->sk_socket);
168 seq_printf(m, " / sk %pK", sk);
169 seq_printf(m, " / bo %pK", bo);
170 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
171 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
172 seq_printf(m, " <<<\n");
173
174 list_for_each_entry(op, &bo->rx_ops, list) {
175
176 unsigned long reduction;
177
178 /* print only active entries & prevent division by zero */
179 if (!op->frames_abs)
180 continue;
181
182 seq_printf(m, "rx_op: %03X %-5s ",
183 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
184 seq_printf(m, "[%u]%c ", op->nframes,
185 (op->flags & RX_CHECK_DLC)?'d':' ');
186 if (op->kt_ival1.tv64)
187 seq_printf(m, "timeo=%lld ",
188 (long long)
189 ktime_to_us(op->kt_ival1));
190
191 if (op->kt_ival2.tv64)
192 seq_printf(m, "thr=%lld ",
193 (long long)
194 ktime_to_us(op->kt_ival2));
195
196 seq_printf(m, "# recv %ld (%ld) => reduction: ",
197 op->frames_filtered, op->frames_abs);
198
199 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
200
201 seq_printf(m, "%s%ld%%\n",
202 (reduction == 100)?"near ":"", reduction);
203 }
204
205 list_for_each_entry(op, &bo->tx_ops, list) {
206
207 seq_printf(m, "tx_op: %03X %s [%u] ",
208 op->can_id,
209 bcm_proc_getifname(ifname, op->ifindex),
210 op->nframes);
211
212 if (op->kt_ival1.tv64)
213 seq_printf(m, "t1=%lld ",
214 (long long) ktime_to_us(op->kt_ival1));
215
216 if (op->kt_ival2.tv64)
217 seq_printf(m, "t2=%lld ",
218 (long long) ktime_to_us(op->kt_ival2));
219
220 seq_printf(m, "# sent %ld\n", op->frames_abs);
221 }
222 seq_putc(m, '\n');
223 return 0;
224}
225
226static int bcm_proc_open(struct inode *inode, struct file *file)
227{
228 return single_open(file, bcm_proc_show, PDE(inode)->data);
229}
230
231static const struct file_operations bcm_proc_fops = {
232 .owner = THIS_MODULE,
233 .open = bcm_proc_open,
234 .read = seq_read,
235 .llseek = seq_lseek,
236 .release = single_release,
237};
238
239/*
240 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
241 * of the given bcm tx op
242 */
243static void bcm_can_tx(struct bcm_op *op)
244{
245 struct sk_buff *skb;
246 struct net_device *dev;
247 struct can_frame *cf = &op->frames[op->currframe];
248
249 /* no target device? => exit */
250 if (!op->ifindex)
251 return;
252
253 dev = dev_get_by_index(&init_net, op->ifindex);
254 if (!dev) {
255 /* RFC: should this bcm_op remove itself here? */
256 return;
257 }
258
259 skb = alloc_skb(CFSIZ, gfp_any());
260 if (!skb)
261 goto out;
262
263 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
264
265 /* send with loopback */
266 skb->dev = dev;
267 skb->sk = op->sk;
268 can_send(skb, 1);
269
270 /* update statistics */
271 op->currframe++;
272 op->frames_abs++;
273
274 /* reached last frame? */
275 if (op->currframe >= op->nframes)
276 op->currframe = 0;
277 out:
278 dev_put(dev);
279}
280
281/*
282 * bcm_send_to_user - send a BCM message to the userspace
283 * (consisting of bcm_msg_head + x CAN frames)
284 */
285static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
286 struct can_frame *frames, int has_timestamp)
287{
288 struct sk_buff *skb;
289 struct can_frame *firstframe;
290 struct sockaddr_can *addr;
291 struct sock *sk = op->sk;
292 unsigned int datalen = head->nframes * CFSIZ;
293 int err;
294
295 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
296 if (!skb)
297 return;
298
299 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
300
301 if (head->nframes) {
302 /* can_frames starting here */
303 firstframe = (struct can_frame *)skb_tail_pointer(skb);
304
305 memcpy(skb_put(skb, datalen), frames, datalen);
306
307 /*
308 * the BCM uses the can_dlc-element of the can_frame
309 * structure for internal purposes. This is only
310 * relevant for updates that are generated by the
311 * BCM, where nframes is 1
312 */
313 if (head->nframes == 1)
314 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
315 }
316
317 if (has_timestamp) {
318 /* restore rx timestamp */
319 skb->tstamp = op->rx_stamp;
320 }
321
322 /*
323 * Put the datagram to the queue so that bcm_recvmsg() can
324 * get it from there. We need to pass the interface index to
325 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
326 * containing the interface index.
327 */
328
329 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
330 addr = (struct sockaddr_can *)skb->cb;
331 memset(addr, 0, sizeof(*addr));
332 addr->can_family = AF_CAN;
333 addr->can_ifindex = op->rx_ifindex;
334
335 err = sock_queue_rcv_skb(sk, skb);
336 if (err < 0) {
337 struct bcm_sock *bo = bcm_sk(sk);
338
339 kfree_skb(skb);
340 /* don't care about overflows in this statistic */
341 bo->dropped_usr_msgs++;
342 }
343}
344
345static void bcm_tx_start_timer(struct bcm_op *op)
346{
347 if (op->kt_ival1.tv64 && op->count)
348 hrtimer_start(&op->timer,
349 ktime_add(ktime_get(), op->kt_ival1),
350 HRTIMER_MODE_ABS);
351 else if (op->kt_ival2.tv64)
352 hrtimer_start(&op->timer,
353 ktime_add(ktime_get(), op->kt_ival2),
354 HRTIMER_MODE_ABS);
355}
356
357static void bcm_tx_timeout_tsklet(unsigned long data)
358{
359 struct bcm_op *op = (struct bcm_op *)data;
360 struct bcm_msg_head msg_head;
361
362 if (op->kt_ival1.tv64 && (op->count > 0)) {
363
364 op->count--;
365 if (!op->count && (op->flags & TX_COUNTEVT)) {
366
367 /* create notification to user */
368 msg_head.opcode = TX_EXPIRED;
369 msg_head.flags = op->flags;
370 msg_head.count = op->count;
371 msg_head.ival1 = op->ival1;
372 msg_head.ival2 = op->ival2;
373 msg_head.can_id = op->can_id;
374 msg_head.nframes = 0;
375
376 bcm_send_to_user(op, &msg_head, NULL, 0);
377 }
378 bcm_can_tx(op);
379
380 } else if (op->kt_ival2.tv64)
381 bcm_can_tx(op);
382
383 bcm_tx_start_timer(op);
384}
385
386/*
387 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
388 */
389static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
390{
391 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
392
393 tasklet_schedule(&op->tsklet);
394
395 return HRTIMER_NORESTART;
396}
397
398/*
399 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
400 */
401static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
402{
403 struct bcm_msg_head head;
404
405 /* update statistics */
406 op->frames_filtered++;
407
408 /* prevent statistics overflow */
409 if (op->frames_filtered > ULONG_MAX/100)
410 op->frames_filtered = op->frames_abs = 0;
411
412 /* this element is not throttled anymore */
413 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
414
415 head.opcode = RX_CHANGED;
416 head.flags = op->flags;
417 head.count = op->count;
418 head.ival1 = op->ival1;
419 head.ival2 = op->ival2;
420 head.can_id = op->can_id;
421 head.nframes = 1;
422
423 bcm_send_to_user(op, &head, data, 1);
424}
425
426/*
427 * bcm_rx_update_and_send - process a detected relevant receive content change
428 * 1. update the last received data
429 * 2. send a notification to the user (if possible)
430 */
431static void bcm_rx_update_and_send(struct bcm_op *op,
432 struct can_frame *lastdata,
433 const struct can_frame *rxdata)
434{
435 memcpy(lastdata, rxdata, CFSIZ);
436
437 /* mark as used and throttled by default */
438 lastdata->can_dlc |= (RX_RECV|RX_THR);
439
440 /* throtteling mode inactive ? */
441 if (!op->kt_ival2.tv64) {
442 /* send RX_CHANGED to the user immediately */
443 bcm_rx_changed(op, lastdata);
444 return;
445 }
446
447 /* with active throttling timer we are just done here */
448 if (hrtimer_active(&op->thrtimer))
449 return;
450
451 /* first receiption with enabled throttling mode */
452 if (!op->kt_lastmsg.tv64)
453 goto rx_changed_settime;
454
455 /* got a second frame inside a potential throttle period? */
456 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
457 ktime_to_us(op->kt_ival2)) {
458 /* do not send the saved data - only start throttle timer */
459 hrtimer_start(&op->thrtimer,
460 ktime_add(op->kt_lastmsg, op->kt_ival2),
461 HRTIMER_MODE_ABS);
462 return;
463 }
464
465 /* the gap was that big, that throttling was not needed here */
466rx_changed_settime:
467 bcm_rx_changed(op, lastdata);
468 op->kt_lastmsg = ktime_get();
469}
470
471/*
472 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
473 * received data stored in op->last_frames[]
474 */
475static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
476 const struct can_frame *rxdata)
477{
478 /*
479 * no one uses the MSBs of can_dlc for comparation,
480 * so we use it here to detect the first time of reception
481 */
482
483 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
484 /* received data for the first time => send update to user */
485 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
486 return;
487 }
488
489 /* do a real check in can_frame data section */
490
491 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
492 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
493 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
494 return;
495 }
496
497 if (op->flags & RX_CHECK_DLC) {
498 /* do a real check in can_frame dlc */
499 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
500 BCM_CAN_DLC_MASK)) {
501 bcm_rx_update_and_send(op, &op->last_frames[index],
502 rxdata);
503 return;
504 }
505 }
506}
507
508/*
509 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
510 */
511static void bcm_rx_starttimer(struct bcm_op *op)
512{
513 if (op->flags & RX_NO_AUTOTIMER)
514 return;
515
516 if (op->kt_ival1.tv64)
517 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
518}
519
520static void bcm_rx_timeout_tsklet(unsigned long data)
521{
522 struct bcm_op *op = (struct bcm_op *)data;
523 struct bcm_msg_head msg_head;
524
525 /* create notification to user */
526 msg_head.opcode = RX_TIMEOUT;
527 msg_head.flags = op->flags;
528 msg_head.count = op->count;
529 msg_head.ival1 = op->ival1;
530 msg_head.ival2 = op->ival2;
531 msg_head.can_id = op->can_id;
532 msg_head.nframes = 0;
533
534 bcm_send_to_user(op, &msg_head, NULL, 0);
535}
536
537/*
538 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
539 */
540static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
541{
542 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
543
544 /* schedule before NET_RX_SOFTIRQ */
545 tasklet_hi_schedule(&op->tsklet);
546
547 /* no restart of the timer is done here! */
548
549 /* if user wants to be informed, when cyclic CAN-Messages come back */
550 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
551 /* clear received can_frames to indicate 'nothing received' */
552 memset(op->last_frames, 0, op->nframes * CFSIZ);
553 }
554
555 return HRTIMER_NORESTART;
556}
557
558/*
559 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
560 */
561static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
562 unsigned int index)
563{
564 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
565 if (update)
566 bcm_rx_changed(op, &op->last_frames[index]);
567 return 1;
568 }
569 return 0;
570}
571
572/*
573 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
574 *
575 * update == 0 : just check if throttled data is available (any irq context)
576 * update == 1 : check and send throttled data to userspace (soft_irq context)
577 */
578static int bcm_rx_thr_flush(struct bcm_op *op, int update)
579{
580 int updated = 0;
581
582 if (op->nframes > 1) {
583 unsigned int i;
584
585 /* for MUX filter we start at index 1 */
586 for (i = 1; i < op->nframes; i++)
587 updated += bcm_rx_do_flush(op, update, i);
588
589 } else {
590 /* for RX_FILTER_ID and simple filter */
591 updated += bcm_rx_do_flush(op, update, 0);
592 }
593
594 return updated;
595}
596
597static void bcm_rx_thr_tsklet(unsigned long data)
598{
599 struct bcm_op *op = (struct bcm_op *)data;
600
601 /* push the changed data to the userspace */
602 bcm_rx_thr_flush(op, 1);
603}
604
605/*
606 * bcm_rx_thr_handler - the time for blocked content updates is over now:
607 * Check for throttled data and send it to the userspace
608 */
609static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
610{
611 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
612
613 tasklet_schedule(&op->thrtsklet);
614
615 if (bcm_rx_thr_flush(op, 0)) {
616 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
617 return HRTIMER_RESTART;
618 } else {
619 /* rearm throttle handling */
620 op->kt_lastmsg = ktime_set(0, 0);
621 return HRTIMER_NORESTART;
622 }
623}
624
625/*
626 * bcm_rx_handler - handle a CAN frame receiption
627 */
628static void bcm_rx_handler(struct sk_buff *skb, void *data)
629{
630 struct bcm_op *op = (struct bcm_op *)data;
631 const struct can_frame *rxframe = (struct can_frame *)skb->data;
632 unsigned int i;
633
634 /* disable timeout */
635 hrtimer_cancel(&op->timer);
636
637 if (op->can_id != rxframe->can_id)
638 return;
639
640 /* save rx timestamp */
641 op->rx_stamp = skb->tstamp;
642 /* save originator for recvfrom() */
643 op->rx_ifindex = skb->dev->ifindex;
644 /* update statistics */
645 op->frames_abs++;
646
647 if (op->flags & RX_RTR_FRAME) {
648 /* send reply for RTR-request (placed in op->frames[0]) */
649 bcm_can_tx(op);
650 return;
651 }
652
653 if (op->flags & RX_FILTER_ID) {
654 /* the easiest case */
655 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
656 goto rx_starttimer;
657 }
658
659 if (op->nframes == 1) {
660 /* simple compare with index 0 */
661 bcm_rx_cmp_to_index(op, 0, rxframe);
662 goto rx_starttimer;
663 }
664
665 if (op->nframes > 1) {
666 /*
667 * multiplex compare
668 *
669 * find the first multiplex mask that fits.
670 * Remark: The MUX-mask is stored in index 0
671 */
672
673 for (i = 1; i < op->nframes; i++) {
674 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
675 (GET_U64(&op->frames[0]) &
676 GET_U64(&op->frames[i]))) {
677 bcm_rx_cmp_to_index(op, i, rxframe);
678 break;
679 }
680 }
681 }
682
683rx_starttimer:
684 bcm_rx_starttimer(op);
685}
686
687/*
688 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
689 */
690static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
691 int ifindex)
692{
693 struct bcm_op *op;
694
695 list_for_each_entry(op, ops, list) {
696 if ((op->can_id == can_id) && (op->ifindex == ifindex))
697 return op;
698 }
699
700 return NULL;
701}
702
703static void bcm_remove_op(struct bcm_op *op)
704{
705 hrtimer_cancel(&op->timer);
706 hrtimer_cancel(&op->thrtimer);
707
708 if (op->tsklet.func)
709 tasklet_kill(&op->tsklet);
710
711 if (op->thrtsklet.func)
712 tasklet_kill(&op->thrtsklet);
713
714 if ((op->frames) && (op->frames != &op->sframe))
715 kfree(op->frames);
716
717 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
718 kfree(op->last_frames);
719
720 kfree(op);
721}
722
723static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
724{
725 if (op->rx_reg_dev == dev) {
726 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
727 bcm_rx_handler, op);
728
729 /* mark as removed subscription */
730 op->rx_reg_dev = NULL;
731 } else
732 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
733 "mismatch %p %p\n", op->rx_reg_dev, dev);
734}
735
736/*
737 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
738 */
739static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
740{
741 struct bcm_op *op, *n;
742
743 list_for_each_entry_safe(op, n, ops, list) {
744 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
745
746 /*
747 * Don't care if we're bound or not (due to netdev
748 * problems) can_rx_unregister() is always a save
749 * thing to do here.
750 */
751 if (op->ifindex) {
752 /*
753 * Only remove subscriptions that had not
754 * been removed due to NETDEV_UNREGISTER
755 * in bcm_notifier()
756 */
757 if (op->rx_reg_dev) {
758 struct net_device *dev;
759
760 dev = dev_get_by_index(&init_net,
761 op->ifindex);
762 if (dev) {
763 bcm_rx_unreg(dev, op);
764 dev_put(dev);
765 }
766 }
767 } else
768 can_rx_unregister(NULL, op->can_id,
769 REGMASK(op->can_id),
770 bcm_rx_handler, op);
771
772 list_del(&op->list);
773 bcm_remove_op(op);
774 return 1; /* done */
775 }
776 }
777
778 return 0; /* not found */
779}
780
781/*
782 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
783 */
784static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
785{
786 struct bcm_op *op, *n;
787
788 list_for_each_entry_safe(op, n, ops, list) {
789 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
790 list_del(&op->list);
791 bcm_remove_op(op);
792 return 1; /* done */
793 }
794 }
795
796 return 0; /* not found */
797}
798
799/*
800 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
801 */
802static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
803 int ifindex)
804{
805 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
806
807 if (!op)
808 return -EINVAL;
809
810 /* put current values into msg_head */
811 msg_head->flags = op->flags;
812 msg_head->count = op->count;
813 msg_head->ival1 = op->ival1;
814 msg_head->ival2 = op->ival2;
815 msg_head->nframes = op->nframes;
816
817 bcm_send_to_user(op, msg_head, op->frames, 0);
818
819 return MHSIZ;
820}
821
822/*
823 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
824 */
825static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
826 int ifindex, struct sock *sk)
827{
828 struct bcm_sock *bo = bcm_sk(sk);
829 struct bcm_op *op;
830 unsigned int i;
831 int err;
832
833 /* we need a real device to send frames */
834 if (!ifindex)
835 return -ENODEV;
836
837 /* check nframes boundaries - we need at least one can_frame */
838 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
839 return -EINVAL;
840
841 /* check the given can_id */
842 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
843
844 if (op) {
845 /* update existing BCM operation */
846
847 /*
848 * Do we need more space for the can_frames than currently
849 * allocated? -> This is a _really_ unusual use-case and
850 * therefore (complexity / locking) it is not supported.
851 */
852 if (msg_head->nframes > op->nframes)
853 return -E2BIG;
854
855 /* update can_frames content */
856 for (i = 0; i < msg_head->nframes; i++) {
857 err = memcpy_fromiovec((u8 *)&op->frames[i],
858 msg->msg_iov, CFSIZ);
859
860 if (op->frames[i].can_dlc > 8)
861 err = -EINVAL;
862
863 if (err < 0)
864 return err;
865
866 if (msg_head->flags & TX_CP_CAN_ID) {
867 /* copy can_id into frame */
868 op->frames[i].can_id = msg_head->can_id;
869 }
870 }
871
872 } else {
873 /* insert new BCM operation for the given can_id */
874
875 op = kzalloc(OPSIZ, GFP_KERNEL);
876 if (!op)
877 return -ENOMEM;
878
879 op->can_id = msg_head->can_id;
880
881 /* create array for can_frames and copy the data */
882 if (msg_head->nframes > 1) {
883 op->frames = kmalloc(msg_head->nframes * CFSIZ,
884 GFP_KERNEL);
885 if (!op->frames) {
886 kfree(op);
887 return -ENOMEM;
888 }
889 } else
890 op->frames = &op->sframe;
891
892 for (i = 0; i < msg_head->nframes; i++) {
893 err = memcpy_fromiovec((u8 *)&op->frames[i],
894 msg->msg_iov, CFSIZ);
895
896 if (op->frames[i].can_dlc > 8)
897 err = -EINVAL;
898
899 if (err < 0) {
900 if (op->frames != &op->sframe)
901 kfree(op->frames);
902 kfree(op);
903 return err;
904 }
905
906 if (msg_head->flags & TX_CP_CAN_ID) {
907 /* copy can_id into frame */
908 op->frames[i].can_id = msg_head->can_id;
909 }
910 }
911
912 /* tx_ops never compare with previous received messages */
913 op->last_frames = NULL;
914
915 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
916 op->sk = sk;
917 op->ifindex = ifindex;
918
919 /* initialize uninitialized (kzalloc) structure */
920 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
921 op->timer.function = bcm_tx_timeout_handler;
922
923 /* initialize tasklet for tx countevent notification */
924 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
925 (unsigned long) op);
926
927 /* currently unused in tx_ops */
928 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
929
930 /* add this bcm_op to the list of the tx_ops */
931 list_add(&op->list, &bo->tx_ops);
932
933 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
934
935 if (op->nframes != msg_head->nframes) {
936 op->nframes = msg_head->nframes;
937 /* start multiple frame transmission with index 0 */
938 op->currframe = 0;
939 }
940
941 /* check flags */
942
943 op->flags = msg_head->flags;
944
945 if (op->flags & TX_RESET_MULTI_IDX) {
946 /* start multiple frame transmission with index 0 */
947 op->currframe = 0;
948 }
949
950 if (op->flags & SETTIMER) {
951 /* set timer values */
952 op->count = msg_head->count;
953 op->ival1 = msg_head->ival1;
954 op->ival2 = msg_head->ival2;
955 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
956 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
957
958 /* disable an active timer due to zero values? */
959 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
960 hrtimer_cancel(&op->timer);
961 }
962
963 if (op->flags & STARTTIMER) {
964 hrtimer_cancel(&op->timer);
965 /* spec: send can_frame when starting timer */
966 op->flags |= TX_ANNOUNCE;
967 }
968
969 if (op->flags & TX_ANNOUNCE) {
970 bcm_can_tx(op);
971 if (op->count)
972 op->count--;
973 }
974
975 if (op->flags & STARTTIMER)
976 bcm_tx_start_timer(op);
977
978 return msg_head->nframes * CFSIZ + MHSIZ;
979}
980
981/*
982 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
983 */
984static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
985 int ifindex, struct sock *sk)
986{
987 struct bcm_sock *bo = bcm_sk(sk);
988 struct bcm_op *op;
989 int do_rx_register;
990 int err = 0;
991
992 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
993 /* be robust against wrong usage ... */
994 msg_head->flags |= RX_FILTER_ID;
995 /* ignore trailing garbage */
996 msg_head->nframes = 0;
997 }
998
999 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1000 if (msg_head->nframes > MAX_NFRAMES + 1)
1001 return -EINVAL;
1002
1003 if ((msg_head->flags & RX_RTR_FRAME) &&
1004 ((msg_head->nframes != 1) ||
1005 (!(msg_head->can_id & CAN_RTR_FLAG))))
1006 return -EINVAL;
1007
1008 /* check the given can_id */
1009 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1010 if (op) {
1011 /* update existing BCM operation */
1012
1013 /*
1014 * Do we need more space for the can_frames than currently
1015 * allocated? -> This is a _really_ unusual use-case and
1016 * therefore (complexity / locking) it is not supported.
1017 */
1018 if (msg_head->nframes > op->nframes)
1019 return -E2BIG;
1020
1021 if (msg_head->nframes) {
1022 /* update can_frames content */
1023 err = memcpy_fromiovec((u8 *)op->frames,
1024 msg->msg_iov,
1025 msg_head->nframes * CFSIZ);
1026 if (err < 0)
1027 return err;
1028
1029 /* clear last_frames to indicate 'nothing received' */
1030 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1031 }
1032
1033 op->nframes = msg_head->nframes;
1034
1035 /* Only an update -> do not call can_rx_register() */
1036 do_rx_register = 0;
1037
1038 } else {
1039 /* insert new BCM operation for the given can_id */
1040 op = kzalloc(OPSIZ, GFP_KERNEL);
1041 if (!op)
1042 return -ENOMEM;
1043
1044 op->can_id = msg_head->can_id;
1045 op->nframes = msg_head->nframes;
1046
1047 if (msg_head->nframes > 1) {
1048 /* create array for can_frames and copy the data */
1049 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1050 GFP_KERNEL);
1051 if (!op->frames) {
1052 kfree(op);
1053 return -ENOMEM;
1054 }
1055
1056 /* create and init array for received can_frames */
1057 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1058 GFP_KERNEL);
1059 if (!op->last_frames) {
1060 kfree(op->frames);
1061 kfree(op);
1062 return -ENOMEM;
1063 }
1064
1065 } else {
1066 op->frames = &op->sframe;
1067 op->last_frames = &op->last_sframe;
1068 }
1069
1070 if (msg_head->nframes) {
1071 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1072 msg_head->nframes * CFSIZ);
1073 if (err < 0) {
1074 if (op->frames != &op->sframe)
1075 kfree(op->frames);
1076 if (op->last_frames != &op->last_sframe)
1077 kfree(op->last_frames);
1078 kfree(op);
1079 return err;
1080 }
1081 }
1082
1083 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1084 op->sk = sk;
1085 op->ifindex = ifindex;
1086
1087 /* initialize uninitialized (kzalloc) structure */
1088 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1089 op->timer.function = bcm_rx_timeout_handler;
1090
1091 /* initialize tasklet for rx timeout notification */
1092 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1093 (unsigned long) op);
1094
1095 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1096 op->thrtimer.function = bcm_rx_thr_handler;
1097
1098 /* initialize tasklet for rx throttle handling */
1099 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1100 (unsigned long) op);
1101
1102 /* add this bcm_op to the list of the rx_ops */
1103 list_add(&op->list, &bo->rx_ops);
1104
1105 /* call can_rx_register() */
1106 do_rx_register = 1;
1107
1108 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1109
1110 /* check flags */
1111 op->flags = msg_head->flags;
1112
1113 if (op->flags & RX_RTR_FRAME) {
1114
1115 /* no timers in RTR-mode */
1116 hrtimer_cancel(&op->thrtimer);
1117 hrtimer_cancel(&op->timer);
1118
1119 /*
1120 * funny feature in RX(!)_SETUP only for RTR-mode:
1121 * copy can_id into frame BUT without RTR-flag to
1122 * prevent a full-load-loopback-test ... ;-]
1123 */
1124 if ((op->flags & TX_CP_CAN_ID) ||
1125 (op->frames[0].can_id == op->can_id))
1126 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1127
1128 } else {
1129 if (op->flags & SETTIMER) {
1130
1131 /* set timer value */
1132 op->ival1 = msg_head->ival1;
1133 op->ival2 = msg_head->ival2;
1134 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1135 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1136
1137 /* disable an active timer due to zero value? */
1138 if (!op->kt_ival1.tv64)
1139 hrtimer_cancel(&op->timer);
1140
1141 /*
1142 * In any case cancel the throttle timer, flush
1143 * potentially blocked msgs and reset throttle handling
1144 */
1145 op->kt_lastmsg = ktime_set(0, 0);
1146 hrtimer_cancel(&op->thrtimer);
1147 bcm_rx_thr_flush(op, 1);
1148 }
1149
1150 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1151 hrtimer_start(&op->timer, op->kt_ival1,
1152 HRTIMER_MODE_REL);
1153 }
1154
1155 /* now we can register for can_ids, if we added a new bcm_op */
1156 if (do_rx_register) {
1157 if (ifindex) {
1158 struct net_device *dev;
1159
1160 dev = dev_get_by_index(&init_net, ifindex);
1161 if (dev) {
1162 err = can_rx_register(dev, op->can_id,
1163 REGMASK(op->can_id),
1164 bcm_rx_handler, op,
1165 "bcm");
1166
1167 op->rx_reg_dev = dev;
1168 dev_put(dev);
1169 }
1170
1171 } else
1172 err = can_rx_register(NULL, op->can_id,
1173 REGMASK(op->can_id),
1174 bcm_rx_handler, op, "bcm");
1175 if (err) {
1176 /* this bcm rx op is broken -> remove it */
1177 list_del(&op->list);
1178 bcm_remove_op(op);
1179 return err;
1180 }
1181 }
1182
1183 return msg_head->nframes * CFSIZ + MHSIZ;
1184}
1185
1186/*
1187 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1188 */
1189static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1190{
1191 struct sk_buff *skb;
1192 struct net_device *dev;
1193 int err;
1194
1195 /* we need a real device to send frames */
1196 if (!ifindex)
1197 return -ENODEV;
1198
1199 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1200
1201 if (!skb)
1202 return -ENOMEM;
1203
1204 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1205 if (err < 0) {
1206 kfree_skb(skb);
1207 return err;
1208 }
1209
1210 dev = dev_get_by_index(&init_net, ifindex);
1211 if (!dev) {
1212 kfree_skb(skb);
1213 return -ENODEV;
1214 }
1215
1216 skb->dev = dev;
1217 skb->sk = sk;
1218 err = can_send(skb, 1); /* send with loopback */
1219 dev_put(dev);
1220
1221 if (err)
1222 return err;
1223
1224 return CFSIZ + MHSIZ;
1225}
1226
1227/*
1228 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1229 */
1230static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1231 struct msghdr *msg, size_t size)
1232{
1233 struct sock *sk = sock->sk;
1234 struct bcm_sock *bo = bcm_sk(sk);
1235 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1236 struct bcm_msg_head msg_head;
1237 int ret; /* read bytes or error codes as return value */
1238
1239 if (!bo->bound)
1240 return -ENOTCONN;
1241
1242 /* check for valid message length from userspace */
1243 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1244 return -EINVAL;
1245
1246 /* check for alternative ifindex for this bcm_op */
1247
1248 if (!ifindex && msg->msg_name) {
1249 /* no bound device as default => check msg_name */
1250 struct sockaddr_can *addr =
1251 (struct sockaddr_can *)msg->msg_name;
1252
1253 if (msg->msg_namelen < sizeof(*addr))
1254 return -EINVAL;
1255
1256 if (addr->can_family != AF_CAN)
1257 return -EINVAL;
1258
1259 /* ifindex from sendto() */
1260 ifindex = addr->can_ifindex;
1261
1262 if (ifindex) {
1263 struct net_device *dev;
1264
1265 dev = dev_get_by_index(&init_net, ifindex);
1266 if (!dev)
1267 return -ENODEV;
1268
1269 if (dev->type != ARPHRD_CAN) {
1270 dev_put(dev);
1271 return -ENODEV;
1272 }
1273
1274 dev_put(dev);
1275 }
1276 }
1277
1278 /* read message head information */
1279
1280 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1281 if (ret < 0)
1282 return ret;
1283
1284 lock_sock(sk);
1285
1286 switch (msg_head.opcode) {
1287
1288 case TX_SETUP:
1289 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1290 break;
1291
1292 case RX_SETUP:
1293 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1294 break;
1295
1296 case TX_DELETE:
1297 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1298 ret = MHSIZ;
1299 else
1300 ret = -EINVAL;
1301 break;
1302
1303 case RX_DELETE:
1304 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1305 ret = MHSIZ;
1306 else
1307 ret = -EINVAL;
1308 break;
1309
1310 case TX_READ:
1311 /* reuse msg_head for the reply to TX_READ */
1312 msg_head.opcode = TX_STATUS;
1313 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1314 break;
1315
1316 case RX_READ:
1317 /* reuse msg_head for the reply to RX_READ */
1318 msg_head.opcode = RX_STATUS;
1319 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1320 break;
1321
1322 case TX_SEND:
1323 /* we need exactly one can_frame behind the msg head */
1324 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1325 ret = -EINVAL;
1326 else
1327 ret = bcm_tx_send(msg, ifindex, sk);
1328 break;
1329
1330 default:
1331 ret = -EINVAL;
1332 break;
1333 }
1334
1335 release_sock(sk);
1336
1337 return ret;
1338}
1339
1340/*
1341 * notification handler for netdevice status changes
1342 */
1343static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1344 void *data)
1345{
1346 struct net_device *dev = (struct net_device *)data;
1347 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1348 struct sock *sk = &bo->sk;
1349 struct bcm_op *op;
1350 int notify_enodev = 0;
1351
1352 if (!net_eq(dev_net(dev), &init_net))
1353 return NOTIFY_DONE;
1354
1355 if (dev->type != ARPHRD_CAN)
1356 return NOTIFY_DONE;
1357
1358 switch (msg) {
1359
1360 case NETDEV_UNREGISTER:
1361 lock_sock(sk);
1362
1363 /* remove device specific receive entries */
1364 list_for_each_entry(op, &bo->rx_ops, list)
1365 if (op->rx_reg_dev == dev)
1366 bcm_rx_unreg(dev, op);
1367
1368 /* remove device reference, if this is our bound device */
1369 if (bo->bound && bo->ifindex == dev->ifindex) {
1370 bo->bound = 0;
1371 bo->ifindex = 0;
1372 notify_enodev = 1;
1373 }
1374
1375 release_sock(sk);
1376
1377 if (notify_enodev) {
1378 sk->sk_err = ENODEV;
1379 if (!sock_flag(sk, SOCK_DEAD))
1380 sk->sk_error_report(sk);
1381 }
1382 break;
1383
1384 case NETDEV_DOWN:
1385 if (bo->bound && bo->ifindex == dev->ifindex) {
1386 sk->sk_err = ENETDOWN;
1387 if (!sock_flag(sk, SOCK_DEAD))
1388 sk->sk_error_report(sk);
1389 }
1390 }
1391
1392 return NOTIFY_DONE;
1393}
1394
1395/*
1396 * initial settings for all BCM sockets to be set at socket creation time
1397 */
1398static int bcm_init(struct sock *sk)
1399{
1400 struct bcm_sock *bo = bcm_sk(sk);
1401
1402 bo->bound = 0;
1403 bo->ifindex = 0;
1404 bo->dropped_usr_msgs = 0;
1405 bo->bcm_proc_read = NULL;
1406
1407 INIT_LIST_HEAD(&bo->tx_ops);
1408 INIT_LIST_HEAD(&bo->rx_ops);
1409
1410 /* set notifier */
1411 bo->notifier.notifier_call = bcm_notifier;
1412
1413 register_netdevice_notifier(&bo->notifier);
1414
1415 return 0;
1416}
1417
1418/*
1419 * standard socket functions
1420 */
1421static int bcm_release(struct socket *sock)
1422{
1423 struct sock *sk = sock->sk;
1424 struct bcm_sock *bo;
1425 struct bcm_op *op, *next;
1426
1427 if (sk == NULL)
1428 return 0;
1429
1430 bo = bcm_sk(sk);
1431
1432 /* remove bcm_ops, timer, rx_unregister(), etc. */
1433
1434 unregister_netdevice_notifier(&bo->notifier);
1435
1436 lock_sock(sk);
1437
1438 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1439 bcm_remove_op(op);
1440
1441 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1442 /*
1443 * Don't care if we're bound or not (due to netdev problems)
1444 * can_rx_unregister() is always a save thing to do here.
1445 */
1446 if (op->ifindex) {
1447 /*
1448 * Only remove subscriptions that had not
1449 * been removed due to NETDEV_UNREGISTER
1450 * in bcm_notifier()
1451 */
1452 if (op->rx_reg_dev) {
1453 struct net_device *dev;
1454
1455 dev = dev_get_by_index(&init_net, op->ifindex);
1456 if (dev) {
1457 bcm_rx_unreg(dev, op);
1458 dev_put(dev);
1459 }
1460 }
1461 } else
1462 can_rx_unregister(NULL, op->can_id,
1463 REGMASK(op->can_id),
1464 bcm_rx_handler, op);
1465
1466 bcm_remove_op(op);
1467 }
1468
1469 /* remove procfs entry */
1470 if (proc_dir && bo->bcm_proc_read)
1471 remove_proc_entry(bo->procname, proc_dir);
1472
1473 /* remove device reference */
1474 if (bo->bound) {
1475 bo->bound = 0;
1476 bo->ifindex = 0;
1477 }
1478
1479 sock_orphan(sk);
1480 sock->sk = NULL;
1481
1482 release_sock(sk);
1483 sock_put(sk);
1484
1485 return 0;
1486}
1487
1488static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1489 int flags)
1490{
1491 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1492 struct sock *sk = sock->sk;
1493 struct bcm_sock *bo = bcm_sk(sk);
1494
1495 if (len < sizeof(*addr))
1496 return -EINVAL;
1497
1498 if (bo->bound)
1499 return -EISCONN;
1500
1501 /* bind a device to this socket */
1502 if (addr->can_ifindex) {
1503 struct net_device *dev;
1504
1505 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1506 if (!dev)
1507 return -ENODEV;
1508
1509 if (dev->type != ARPHRD_CAN) {
1510 dev_put(dev);
1511 return -ENODEV;
1512 }
1513
1514 bo->ifindex = dev->ifindex;
1515 dev_put(dev);
1516
1517 } else {
1518 /* no interface reference for ifindex = 0 ('any' CAN device) */
1519 bo->ifindex = 0;
1520 }
1521
1522 bo->bound = 1;
1523
1524 if (proc_dir) {
1525 /* unique socket address as filename */
1526 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1527 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1528 proc_dir,
1529 &bcm_proc_fops, sk);
1530 }
1531
1532 return 0;
1533}
1534
1535static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1536 struct msghdr *msg, size_t size, int flags)
1537{
1538 struct sock *sk = sock->sk;
1539 struct sk_buff *skb;
1540 int error = 0;
1541 int noblock;
1542 int err;
1543
1544 noblock = flags & MSG_DONTWAIT;
1545 flags &= ~MSG_DONTWAIT;
1546 skb = skb_recv_datagram(sk, flags, noblock, &error);
1547 if (!skb)
1548 return error;
1549
1550 if (skb->len < size)
1551 size = skb->len;
1552
1553 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1554 if (err < 0) {
1555 skb_free_datagram(sk, skb);
1556 return err;
1557 }
1558
1559 sock_recv_ts_and_drops(msg, sk, skb);
1560
1561 if (msg->msg_name) {
1562 msg->msg_namelen = sizeof(struct sockaddr_can);
1563 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1564 }
1565
1566 skb_free_datagram(sk, skb);
1567
1568 return size;
1569}
1570
1571static const struct proto_ops bcm_ops = {
1572 .family = PF_CAN,
1573 .release = bcm_release,
1574 .bind = sock_no_bind,
1575 .connect = bcm_connect,
1576 .socketpair = sock_no_socketpair,
1577 .accept = sock_no_accept,
1578 .getname = sock_no_getname,
1579 .poll = datagram_poll,
1580 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1581 .listen = sock_no_listen,
1582 .shutdown = sock_no_shutdown,
1583 .setsockopt = sock_no_setsockopt,
1584 .getsockopt = sock_no_getsockopt,
1585 .sendmsg = bcm_sendmsg,
1586 .recvmsg = bcm_recvmsg,
1587 .mmap = sock_no_mmap,
1588 .sendpage = sock_no_sendpage,
1589};
1590
1591static struct proto bcm_proto __read_mostly = {
1592 .name = "CAN_BCM",
1593 .owner = THIS_MODULE,
1594 .obj_size = sizeof(struct bcm_sock),
1595 .init = bcm_init,
1596};
1597
1598static const struct can_proto bcm_can_proto = {
1599 .type = SOCK_DGRAM,
1600 .protocol = CAN_BCM,
1601 .ops = &bcm_ops,
1602 .prot = &bcm_proto,
1603};
1604
1605static int __init bcm_module_init(void)
1606{
1607 int err;
1608
1609 printk(banner);
1610
1611 err = can_proto_register(&bcm_can_proto);
1612 if (err < 0) {
1613 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1614 return err;
1615 }
1616
1617 /* create /proc/net/can-bcm directory */
1618 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1619 return 0;
1620}
1621
1622static void __exit bcm_module_exit(void)
1623{
1624 can_proto_unregister(&bcm_can_proto);
1625
1626 if (proc_dir)
1627 proc_net_remove(&init_net, "can-bcm");
1628}
1629
1630module_init(bcm_module_init);
1631module_exit(bcm_module_exit);
1/*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2007 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 * Send feedback to <socketcan-users@lists.berlios.de>
41 *
42 */
43
44#include <linux/module.h>
45#include <linux/init.h>
46#include <linux/interrupt.h>
47#include <linux/hrtimer.h>
48#include <linux/list.h>
49#include <linux/proc_fs.h>
50#include <linux/seq_file.h>
51#include <linux/uio.h>
52#include <linux/net.h>
53#include <linux/netdevice.h>
54#include <linux/socket.h>
55#include <linux/if_arp.h>
56#include <linux/skbuff.h>
57#include <linux/can.h>
58#include <linux/can/core.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/* use of last_frames[index].can_dlc */
72#define RX_RECV 0x40 /* received data for this element */
73#define RX_THR 0x80 /* element not been sent due to throttle feature */
74#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
75
76/* get best masking value for can_rx_register() for a given single can_id */
77#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
78 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
79 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
80
81#define CAN_BCM_VERSION CAN_VERSION
82static __initdata const char banner[] = KERN_INFO
83 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
84
85MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
86MODULE_LICENSE("Dual BSD/GPL");
87MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
88MODULE_ALIAS("can-proto-2");
89
90/* easy access to can_frame payload */
91static inline u64 GET_U64(const struct can_frame *cp)
92{
93 return *(u64 *)cp->data;
94}
95
96struct bcm_op {
97 struct list_head list;
98 int ifindex;
99 canid_t can_id;
100 u32 flags;
101 unsigned long frames_abs, frames_filtered;
102 struct timeval ival1, ival2;
103 struct hrtimer timer, thrtimer;
104 struct tasklet_struct tsklet, thrtsklet;
105 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
106 int rx_ifindex;
107 u32 count;
108 u32 nframes;
109 u32 currframe;
110 struct can_frame *frames;
111 struct can_frame *last_frames;
112 struct can_frame sframe;
113 struct can_frame last_sframe;
114 struct sock *sk;
115 struct net_device *rx_reg_dev;
116};
117
118static struct proc_dir_entry *proc_dir;
119
120struct bcm_sock {
121 struct sock sk;
122 int bound;
123 int ifindex;
124 struct notifier_block notifier;
125 struct list_head rx_ops;
126 struct list_head tx_ops;
127 unsigned long dropped_usr_msgs;
128 struct proc_dir_entry *bcm_proc_read;
129 char procname [32]; /* inode number in decimal with \0 */
130};
131
132static inline struct bcm_sock *bcm_sk(const struct sock *sk)
133{
134 return (struct bcm_sock *)sk;
135}
136
137#define CFSIZ sizeof(struct can_frame)
138#define OPSIZ sizeof(struct bcm_op)
139#define MHSIZ sizeof(struct bcm_msg_head)
140
141/*
142 * procfs functions
143 */
144static char *bcm_proc_getifname(char *result, int ifindex)
145{
146 struct net_device *dev;
147
148 if (!ifindex)
149 return "any";
150
151 rcu_read_lock();
152 dev = dev_get_by_index_rcu(&init_net, ifindex);
153 if (dev)
154 strcpy(result, dev->name);
155 else
156 strcpy(result, "???");
157 rcu_read_unlock();
158
159 return result;
160}
161
162static int bcm_proc_show(struct seq_file *m, void *v)
163{
164 char ifname[IFNAMSIZ];
165 struct sock *sk = (struct sock *)m->private;
166 struct bcm_sock *bo = bcm_sk(sk);
167 struct bcm_op *op;
168
169 seq_printf(m, ">>> socket %pK", sk->sk_socket);
170 seq_printf(m, " / sk %pK", sk);
171 seq_printf(m, " / bo %pK", bo);
172 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
173 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
174 seq_printf(m, " <<<\n");
175
176 list_for_each_entry(op, &bo->rx_ops, list) {
177
178 unsigned long reduction;
179
180 /* print only active entries & prevent division by zero */
181 if (!op->frames_abs)
182 continue;
183
184 seq_printf(m, "rx_op: %03X %-5s ",
185 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
186 seq_printf(m, "[%u]%c ", op->nframes,
187 (op->flags & RX_CHECK_DLC)?'d':' ');
188 if (op->kt_ival1.tv64)
189 seq_printf(m, "timeo=%lld ",
190 (long long)
191 ktime_to_us(op->kt_ival1));
192
193 if (op->kt_ival2.tv64)
194 seq_printf(m, "thr=%lld ",
195 (long long)
196 ktime_to_us(op->kt_ival2));
197
198 seq_printf(m, "# recv %ld (%ld) => reduction: ",
199 op->frames_filtered, op->frames_abs);
200
201 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
202
203 seq_printf(m, "%s%ld%%\n",
204 (reduction == 100)?"near ":"", reduction);
205 }
206
207 list_for_each_entry(op, &bo->tx_ops, list) {
208
209 seq_printf(m, "tx_op: %03X %s [%u] ",
210 op->can_id,
211 bcm_proc_getifname(ifname, op->ifindex),
212 op->nframes);
213
214 if (op->kt_ival1.tv64)
215 seq_printf(m, "t1=%lld ",
216 (long long) ktime_to_us(op->kt_ival1));
217
218 if (op->kt_ival2.tv64)
219 seq_printf(m, "t2=%lld ",
220 (long long) ktime_to_us(op->kt_ival2));
221
222 seq_printf(m, "# sent %ld\n", op->frames_abs);
223 }
224 seq_putc(m, '\n');
225 return 0;
226}
227
228static int bcm_proc_open(struct inode *inode, struct file *file)
229{
230 return single_open(file, bcm_proc_show, PDE(inode)->data);
231}
232
233static const struct file_operations bcm_proc_fops = {
234 .owner = THIS_MODULE,
235 .open = bcm_proc_open,
236 .read = seq_read,
237 .llseek = seq_lseek,
238 .release = single_release,
239};
240
241/*
242 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
243 * of the given bcm tx op
244 */
245static void bcm_can_tx(struct bcm_op *op)
246{
247 struct sk_buff *skb;
248 struct net_device *dev;
249 struct can_frame *cf = &op->frames[op->currframe];
250
251 /* no target device? => exit */
252 if (!op->ifindex)
253 return;
254
255 dev = dev_get_by_index(&init_net, op->ifindex);
256 if (!dev) {
257 /* RFC: should this bcm_op remove itself here? */
258 return;
259 }
260
261 skb = alloc_skb(CFSIZ, gfp_any());
262 if (!skb)
263 goto out;
264
265 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
266
267 /* send with loopback */
268 skb->dev = dev;
269 skb->sk = op->sk;
270 can_send(skb, 1);
271
272 /* update statistics */
273 op->currframe++;
274 op->frames_abs++;
275
276 /* reached last frame? */
277 if (op->currframe >= op->nframes)
278 op->currframe = 0;
279 out:
280 dev_put(dev);
281}
282
283/*
284 * bcm_send_to_user - send a BCM message to the userspace
285 * (consisting of bcm_msg_head + x CAN frames)
286 */
287static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
288 struct can_frame *frames, int has_timestamp)
289{
290 struct sk_buff *skb;
291 struct can_frame *firstframe;
292 struct sockaddr_can *addr;
293 struct sock *sk = op->sk;
294 unsigned int datalen = head->nframes * CFSIZ;
295 int err;
296
297 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
298 if (!skb)
299 return;
300
301 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
302
303 if (head->nframes) {
304 /* can_frames starting here */
305 firstframe = (struct can_frame *)skb_tail_pointer(skb);
306
307 memcpy(skb_put(skb, datalen), frames, datalen);
308
309 /*
310 * the BCM uses the can_dlc-element of the can_frame
311 * structure for internal purposes. This is only
312 * relevant for updates that are generated by the
313 * BCM, where nframes is 1
314 */
315 if (head->nframes == 1)
316 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
317 }
318
319 if (has_timestamp) {
320 /* restore rx timestamp */
321 skb->tstamp = op->rx_stamp;
322 }
323
324 /*
325 * Put the datagram to the queue so that bcm_recvmsg() can
326 * get it from there. We need to pass the interface index to
327 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
328 * containing the interface index.
329 */
330
331 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
332 addr = (struct sockaddr_can *)skb->cb;
333 memset(addr, 0, sizeof(*addr));
334 addr->can_family = AF_CAN;
335 addr->can_ifindex = op->rx_ifindex;
336
337 err = sock_queue_rcv_skb(sk, skb);
338 if (err < 0) {
339 struct bcm_sock *bo = bcm_sk(sk);
340
341 kfree_skb(skb);
342 /* don't care about overflows in this statistic */
343 bo->dropped_usr_msgs++;
344 }
345}
346
347static void bcm_tx_start_timer(struct bcm_op *op)
348{
349 if (op->kt_ival1.tv64 && op->count)
350 hrtimer_start(&op->timer,
351 ktime_add(ktime_get(), op->kt_ival1),
352 HRTIMER_MODE_ABS);
353 else if (op->kt_ival2.tv64)
354 hrtimer_start(&op->timer,
355 ktime_add(ktime_get(), op->kt_ival2),
356 HRTIMER_MODE_ABS);
357}
358
359static void bcm_tx_timeout_tsklet(unsigned long data)
360{
361 struct bcm_op *op = (struct bcm_op *)data;
362 struct bcm_msg_head msg_head;
363
364 if (op->kt_ival1.tv64 && (op->count > 0)) {
365
366 op->count--;
367 if (!op->count && (op->flags & TX_COUNTEVT)) {
368
369 /* create notification to user */
370 msg_head.opcode = TX_EXPIRED;
371 msg_head.flags = op->flags;
372 msg_head.count = op->count;
373 msg_head.ival1 = op->ival1;
374 msg_head.ival2 = op->ival2;
375 msg_head.can_id = op->can_id;
376 msg_head.nframes = 0;
377
378 bcm_send_to_user(op, &msg_head, NULL, 0);
379 }
380 bcm_can_tx(op);
381
382 } else if (op->kt_ival2.tv64)
383 bcm_can_tx(op);
384
385 bcm_tx_start_timer(op);
386}
387
388/*
389 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
390 */
391static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
392{
393 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
394
395 tasklet_schedule(&op->tsklet);
396
397 return HRTIMER_NORESTART;
398}
399
400/*
401 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
402 */
403static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
404{
405 struct bcm_msg_head head;
406
407 /* update statistics */
408 op->frames_filtered++;
409
410 /* prevent statistics overflow */
411 if (op->frames_filtered > ULONG_MAX/100)
412 op->frames_filtered = op->frames_abs = 0;
413
414 /* this element is not throttled anymore */
415 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
416
417 head.opcode = RX_CHANGED;
418 head.flags = op->flags;
419 head.count = op->count;
420 head.ival1 = op->ival1;
421 head.ival2 = op->ival2;
422 head.can_id = op->can_id;
423 head.nframes = 1;
424
425 bcm_send_to_user(op, &head, data, 1);
426}
427
428/*
429 * bcm_rx_update_and_send - process a detected relevant receive content change
430 * 1. update the last received data
431 * 2. send a notification to the user (if possible)
432 */
433static void bcm_rx_update_and_send(struct bcm_op *op,
434 struct can_frame *lastdata,
435 const struct can_frame *rxdata)
436{
437 memcpy(lastdata, rxdata, CFSIZ);
438
439 /* mark as used and throttled by default */
440 lastdata->can_dlc |= (RX_RECV|RX_THR);
441
442 /* throtteling mode inactive ? */
443 if (!op->kt_ival2.tv64) {
444 /* send RX_CHANGED to the user immediately */
445 bcm_rx_changed(op, lastdata);
446 return;
447 }
448
449 /* with active throttling timer we are just done here */
450 if (hrtimer_active(&op->thrtimer))
451 return;
452
453 /* first receiption with enabled throttling mode */
454 if (!op->kt_lastmsg.tv64)
455 goto rx_changed_settime;
456
457 /* got a second frame inside a potential throttle period? */
458 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
459 ktime_to_us(op->kt_ival2)) {
460 /* do not send the saved data - only start throttle timer */
461 hrtimer_start(&op->thrtimer,
462 ktime_add(op->kt_lastmsg, op->kt_ival2),
463 HRTIMER_MODE_ABS);
464 return;
465 }
466
467 /* the gap was that big, that throttling was not needed here */
468rx_changed_settime:
469 bcm_rx_changed(op, lastdata);
470 op->kt_lastmsg = ktime_get();
471}
472
473/*
474 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
475 * received data stored in op->last_frames[]
476 */
477static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
478 const struct can_frame *rxdata)
479{
480 /*
481 * no one uses the MSBs of can_dlc for comparation,
482 * so we use it here to detect the first time of reception
483 */
484
485 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
486 /* received data for the first time => send update to user */
487 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
488 return;
489 }
490
491 /* do a real check in can_frame data section */
492
493 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
494 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
495 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
496 return;
497 }
498
499 if (op->flags & RX_CHECK_DLC) {
500 /* do a real check in can_frame dlc */
501 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
502 BCM_CAN_DLC_MASK)) {
503 bcm_rx_update_and_send(op, &op->last_frames[index],
504 rxdata);
505 return;
506 }
507 }
508}
509
510/*
511 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
512 */
513static void bcm_rx_starttimer(struct bcm_op *op)
514{
515 if (op->flags & RX_NO_AUTOTIMER)
516 return;
517
518 if (op->kt_ival1.tv64)
519 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
520}
521
522static void bcm_rx_timeout_tsklet(unsigned long data)
523{
524 struct bcm_op *op = (struct bcm_op *)data;
525 struct bcm_msg_head msg_head;
526
527 /* create notification to user */
528 msg_head.opcode = RX_TIMEOUT;
529 msg_head.flags = op->flags;
530 msg_head.count = op->count;
531 msg_head.ival1 = op->ival1;
532 msg_head.ival2 = op->ival2;
533 msg_head.can_id = op->can_id;
534 msg_head.nframes = 0;
535
536 bcm_send_to_user(op, &msg_head, NULL, 0);
537}
538
539/*
540 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
541 */
542static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
543{
544 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
545
546 /* schedule before NET_RX_SOFTIRQ */
547 tasklet_hi_schedule(&op->tsklet);
548
549 /* no restart of the timer is done here! */
550
551 /* if user wants to be informed, when cyclic CAN-Messages come back */
552 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
553 /* clear received can_frames to indicate 'nothing received' */
554 memset(op->last_frames, 0, op->nframes * CFSIZ);
555 }
556
557 return HRTIMER_NORESTART;
558}
559
560/*
561 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
562 */
563static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
564 unsigned int index)
565{
566 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
567 if (update)
568 bcm_rx_changed(op, &op->last_frames[index]);
569 return 1;
570 }
571 return 0;
572}
573
574/*
575 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
576 *
577 * update == 0 : just check if throttled data is available (any irq context)
578 * update == 1 : check and send throttled data to userspace (soft_irq context)
579 */
580static int bcm_rx_thr_flush(struct bcm_op *op, int update)
581{
582 int updated = 0;
583
584 if (op->nframes > 1) {
585 unsigned int i;
586
587 /* for MUX filter we start at index 1 */
588 for (i = 1; i < op->nframes; i++)
589 updated += bcm_rx_do_flush(op, update, i);
590
591 } else {
592 /* for RX_FILTER_ID and simple filter */
593 updated += bcm_rx_do_flush(op, update, 0);
594 }
595
596 return updated;
597}
598
599static void bcm_rx_thr_tsklet(unsigned long data)
600{
601 struct bcm_op *op = (struct bcm_op *)data;
602
603 /* push the changed data to the userspace */
604 bcm_rx_thr_flush(op, 1);
605}
606
607/*
608 * bcm_rx_thr_handler - the time for blocked content updates is over now:
609 * Check for throttled data and send it to the userspace
610 */
611static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
612{
613 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
614
615 tasklet_schedule(&op->thrtsklet);
616
617 if (bcm_rx_thr_flush(op, 0)) {
618 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
619 return HRTIMER_RESTART;
620 } else {
621 /* rearm throttle handling */
622 op->kt_lastmsg = ktime_set(0, 0);
623 return HRTIMER_NORESTART;
624 }
625}
626
627/*
628 * bcm_rx_handler - handle a CAN frame receiption
629 */
630static void bcm_rx_handler(struct sk_buff *skb, void *data)
631{
632 struct bcm_op *op = (struct bcm_op *)data;
633 const struct can_frame *rxframe = (struct can_frame *)skb->data;
634 unsigned int i;
635
636 /* disable timeout */
637 hrtimer_cancel(&op->timer);
638
639 if (op->can_id != rxframe->can_id)
640 return;
641
642 /* save rx timestamp */
643 op->rx_stamp = skb->tstamp;
644 /* save originator for recvfrom() */
645 op->rx_ifindex = skb->dev->ifindex;
646 /* update statistics */
647 op->frames_abs++;
648
649 if (op->flags & RX_RTR_FRAME) {
650 /* send reply for RTR-request (placed in op->frames[0]) */
651 bcm_can_tx(op);
652 return;
653 }
654
655 if (op->flags & RX_FILTER_ID) {
656 /* the easiest case */
657 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
658 goto rx_starttimer;
659 }
660
661 if (op->nframes == 1) {
662 /* simple compare with index 0 */
663 bcm_rx_cmp_to_index(op, 0, rxframe);
664 goto rx_starttimer;
665 }
666
667 if (op->nframes > 1) {
668 /*
669 * multiplex compare
670 *
671 * find the first multiplex mask that fits.
672 * Remark: The MUX-mask is stored in index 0
673 */
674
675 for (i = 1; i < op->nframes; i++) {
676 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
677 (GET_U64(&op->frames[0]) &
678 GET_U64(&op->frames[i]))) {
679 bcm_rx_cmp_to_index(op, i, rxframe);
680 break;
681 }
682 }
683 }
684
685rx_starttimer:
686 bcm_rx_starttimer(op);
687}
688
689/*
690 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
691 */
692static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
693 int ifindex)
694{
695 struct bcm_op *op;
696
697 list_for_each_entry(op, ops, list) {
698 if ((op->can_id == can_id) && (op->ifindex == ifindex))
699 return op;
700 }
701
702 return NULL;
703}
704
705static void bcm_remove_op(struct bcm_op *op)
706{
707 hrtimer_cancel(&op->timer);
708 hrtimer_cancel(&op->thrtimer);
709
710 if (op->tsklet.func)
711 tasklet_kill(&op->tsklet);
712
713 if (op->thrtsklet.func)
714 tasklet_kill(&op->thrtsklet);
715
716 if ((op->frames) && (op->frames != &op->sframe))
717 kfree(op->frames);
718
719 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
720 kfree(op->last_frames);
721
722 kfree(op);
723}
724
725static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
726{
727 if (op->rx_reg_dev == dev) {
728 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
729 bcm_rx_handler, op);
730
731 /* mark as removed subscription */
732 op->rx_reg_dev = NULL;
733 } else
734 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
735 "mismatch %p %p\n", op->rx_reg_dev, dev);
736}
737
738/*
739 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
740 */
741static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
742{
743 struct bcm_op *op, *n;
744
745 list_for_each_entry_safe(op, n, ops, list) {
746 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
747
748 /*
749 * Don't care if we're bound or not (due to netdev
750 * problems) can_rx_unregister() is always a save
751 * thing to do here.
752 */
753 if (op->ifindex) {
754 /*
755 * Only remove subscriptions that had not
756 * been removed due to NETDEV_UNREGISTER
757 * in bcm_notifier()
758 */
759 if (op->rx_reg_dev) {
760 struct net_device *dev;
761
762 dev = dev_get_by_index(&init_net,
763 op->ifindex);
764 if (dev) {
765 bcm_rx_unreg(dev, op);
766 dev_put(dev);
767 }
768 }
769 } else
770 can_rx_unregister(NULL, op->can_id,
771 REGMASK(op->can_id),
772 bcm_rx_handler, op);
773
774 list_del(&op->list);
775 bcm_remove_op(op);
776 return 1; /* done */
777 }
778 }
779
780 return 0; /* not found */
781}
782
783/*
784 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
785 */
786static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
787{
788 struct bcm_op *op, *n;
789
790 list_for_each_entry_safe(op, n, ops, list) {
791 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
792 list_del(&op->list);
793 bcm_remove_op(op);
794 return 1; /* done */
795 }
796 }
797
798 return 0; /* not found */
799}
800
801/*
802 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
803 */
804static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
805 int ifindex)
806{
807 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
808
809 if (!op)
810 return -EINVAL;
811
812 /* put current values into msg_head */
813 msg_head->flags = op->flags;
814 msg_head->count = op->count;
815 msg_head->ival1 = op->ival1;
816 msg_head->ival2 = op->ival2;
817 msg_head->nframes = op->nframes;
818
819 bcm_send_to_user(op, msg_head, op->frames, 0);
820
821 return MHSIZ;
822}
823
824/*
825 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
826 */
827static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
828 int ifindex, struct sock *sk)
829{
830 struct bcm_sock *bo = bcm_sk(sk);
831 struct bcm_op *op;
832 unsigned int i;
833 int err;
834
835 /* we need a real device to send frames */
836 if (!ifindex)
837 return -ENODEV;
838
839 /* check nframes boundaries - we need at least one can_frame */
840 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
841 return -EINVAL;
842
843 /* check the given can_id */
844 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
845
846 if (op) {
847 /* update existing BCM operation */
848
849 /*
850 * Do we need more space for the can_frames than currently
851 * allocated? -> This is a _really_ unusual use-case and
852 * therefore (complexity / locking) it is not supported.
853 */
854 if (msg_head->nframes > op->nframes)
855 return -E2BIG;
856
857 /* update can_frames content */
858 for (i = 0; i < msg_head->nframes; i++) {
859 err = memcpy_fromiovec((u8 *)&op->frames[i],
860 msg->msg_iov, CFSIZ);
861
862 if (op->frames[i].can_dlc > 8)
863 err = -EINVAL;
864
865 if (err < 0)
866 return err;
867
868 if (msg_head->flags & TX_CP_CAN_ID) {
869 /* copy can_id into frame */
870 op->frames[i].can_id = msg_head->can_id;
871 }
872 }
873
874 } else {
875 /* insert new BCM operation for the given can_id */
876
877 op = kzalloc(OPSIZ, GFP_KERNEL);
878 if (!op)
879 return -ENOMEM;
880
881 op->can_id = msg_head->can_id;
882
883 /* create array for can_frames and copy the data */
884 if (msg_head->nframes > 1) {
885 op->frames = kmalloc(msg_head->nframes * CFSIZ,
886 GFP_KERNEL);
887 if (!op->frames) {
888 kfree(op);
889 return -ENOMEM;
890 }
891 } else
892 op->frames = &op->sframe;
893
894 for (i = 0; i < msg_head->nframes; i++) {
895 err = memcpy_fromiovec((u8 *)&op->frames[i],
896 msg->msg_iov, CFSIZ);
897
898 if (op->frames[i].can_dlc > 8)
899 err = -EINVAL;
900
901 if (err < 0) {
902 if (op->frames != &op->sframe)
903 kfree(op->frames);
904 kfree(op);
905 return err;
906 }
907
908 if (msg_head->flags & TX_CP_CAN_ID) {
909 /* copy can_id into frame */
910 op->frames[i].can_id = msg_head->can_id;
911 }
912 }
913
914 /* tx_ops never compare with previous received messages */
915 op->last_frames = NULL;
916
917 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
918 op->sk = sk;
919 op->ifindex = ifindex;
920
921 /* initialize uninitialized (kzalloc) structure */
922 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
923 op->timer.function = bcm_tx_timeout_handler;
924
925 /* initialize tasklet for tx countevent notification */
926 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
927 (unsigned long) op);
928
929 /* currently unused in tx_ops */
930 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
931
932 /* add this bcm_op to the list of the tx_ops */
933 list_add(&op->list, &bo->tx_ops);
934
935 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
936
937 if (op->nframes != msg_head->nframes) {
938 op->nframes = msg_head->nframes;
939 /* start multiple frame transmission with index 0 */
940 op->currframe = 0;
941 }
942
943 /* check flags */
944
945 op->flags = msg_head->flags;
946
947 if (op->flags & TX_RESET_MULTI_IDX) {
948 /* start multiple frame transmission with index 0 */
949 op->currframe = 0;
950 }
951
952 if (op->flags & SETTIMER) {
953 /* set timer values */
954 op->count = msg_head->count;
955 op->ival1 = msg_head->ival1;
956 op->ival2 = msg_head->ival2;
957 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
958 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
959
960 /* disable an active timer due to zero values? */
961 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
962 hrtimer_cancel(&op->timer);
963 }
964
965 if (op->flags & STARTTIMER) {
966 hrtimer_cancel(&op->timer);
967 /* spec: send can_frame when starting timer */
968 op->flags |= TX_ANNOUNCE;
969 }
970
971 if (op->flags & TX_ANNOUNCE) {
972 bcm_can_tx(op);
973 if (op->count)
974 op->count--;
975 }
976
977 if (op->flags & STARTTIMER)
978 bcm_tx_start_timer(op);
979
980 return msg_head->nframes * CFSIZ + MHSIZ;
981}
982
983/*
984 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
985 */
986static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
987 int ifindex, struct sock *sk)
988{
989 struct bcm_sock *bo = bcm_sk(sk);
990 struct bcm_op *op;
991 int do_rx_register;
992 int err = 0;
993
994 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
995 /* be robust against wrong usage ... */
996 msg_head->flags |= RX_FILTER_ID;
997 /* ignore trailing garbage */
998 msg_head->nframes = 0;
999 }
1000
1001 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1002 if (msg_head->nframes > MAX_NFRAMES + 1)
1003 return -EINVAL;
1004
1005 if ((msg_head->flags & RX_RTR_FRAME) &&
1006 ((msg_head->nframes != 1) ||
1007 (!(msg_head->can_id & CAN_RTR_FLAG))))
1008 return -EINVAL;
1009
1010 /* check the given can_id */
1011 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1012 if (op) {
1013 /* update existing BCM operation */
1014
1015 /*
1016 * Do we need more space for the can_frames than currently
1017 * allocated? -> This is a _really_ unusual use-case and
1018 * therefore (complexity / locking) it is not supported.
1019 */
1020 if (msg_head->nframes > op->nframes)
1021 return -E2BIG;
1022
1023 if (msg_head->nframes) {
1024 /* update can_frames content */
1025 err = memcpy_fromiovec((u8 *)op->frames,
1026 msg->msg_iov,
1027 msg_head->nframes * CFSIZ);
1028 if (err < 0)
1029 return err;
1030
1031 /* clear last_frames to indicate 'nothing received' */
1032 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1033 }
1034
1035 op->nframes = msg_head->nframes;
1036
1037 /* Only an update -> do not call can_rx_register() */
1038 do_rx_register = 0;
1039
1040 } else {
1041 /* insert new BCM operation for the given can_id */
1042 op = kzalloc(OPSIZ, GFP_KERNEL);
1043 if (!op)
1044 return -ENOMEM;
1045
1046 op->can_id = msg_head->can_id;
1047 op->nframes = msg_head->nframes;
1048
1049 if (msg_head->nframes > 1) {
1050 /* create array for can_frames and copy the data */
1051 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1052 GFP_KERNEL);
1053 if (!op->frames) {
1054 kfree(op);
1055 return -ENOMEM;
1056 }
1057
1058 /* create and init array for received can_frames */
1059 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1060 GFP_KERNEL);
1061 if (!op->last_frames) {
1062 kfree(op->frames);
1063 kfree(op);
1064 return -ENOMEM;
1065 }
1066
1067 } else {
1068 op->frames = &op->sframe;
1069 op->last_frames = &op->last_sframe;
1070 }
1071
1072 if (msg_head->nframes) {
1073 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1074 msg_head->nframes * CFSIZ);
1075 if (err < 0) {
1076 if (op->frames != &op->sframe)
1077 kfree(op->frames);
1078 if (op->last_frames != &op->last_sframe)
1079 kfree(op->last_frames);
1080 kfree(op);
1081 return err;
1082 }
1083 }
1084
1085 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1086 op->sk = sk;
1087 op->ifindex = ifindex;
1088
1089 /* initialize uninitialized (kzalloc) structure */
1090 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1091 op->timer.function = bcm_rx_timeout_handler;
1092
1093 /* initialize tasklet for rx timeout notification */
1094 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1095 (unsigned long) op);
1096
1097 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1098 op->thrtimer.function = bcm_rx_thr_handler;
1099
1100 /* initialize tasklet for rx throttle handling */
1101 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1102 (unsigned long) op);
1103
1104 /* add this bcm_op to the list of the rx_ops */
1105 list_add(&op->list, &bo->rx_ops);
1106
1107 /* call can_rx_register() */
1108 do_rx_register = 1;
1109
1110 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1111
1112 /* check flags */
1113 op->flags = msg_head->flags;
1114
1115 if (op->flags & RX_RTR_FRAME) {
1116
1117 /* no timers in RTR-mode */
1118 hrtimer_cancel(&op->thrtimer);
1119 hrtimer_cancel(&op->timer);
1120
1121 /*
1122 * funny feature in RX(!)_SETUP only for RTR-mode:
1123 * copy can_id into frame BUT without RTR-flag to
1124 * prevent a full-load-loopback-test ... ;-]
1125 */
1126 if ((op->flags & TX_CP_CAN_ID) ||
1127 (op->frames[0].can_id == op->can_id))
1128 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1129
1130 } else {
1131 if (op->flags & SETTIMER) {
1132
1133 /* set timer value */
1134 op->ival1 = msg_head->ival1;
1135 op->ival2 = msg_head->ival2;
1136 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1137 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1138
1139 /* disable an active timer due to zero value? */
1140 if (!op->kt_ival1.tv64)
1141 hrtimer_cancel(&op->timer);
1142
1143 /*
1144 * In any case cancel the throttle timer, flush
1145 * potentially blocked msgs and reset throttle handling
1146 */
1147 op->kt_lastmsg = ktime_set(0, 0);
1148 hrtimer_cancel(&op->thrtimer);
1149 bcm_rx_thr_flush(op, 1);
1150 }
1151
1152 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1153 hrtimer_start(&op->timer, op->kt_ival1,
1154 HRTIMER_MODE_REL);
1155 }
1156
1157 /* now we can register for can_ids, if we added a new bcm_op */
1158 if (do_rx_register) {
1159 if (ifindex) {
1160 struct net_device *dev;
1161
1162 dev = dev_get_by_index(&init_net, ifindex);
1163 if (dev) {
1164 err = can_rx_register(dev, op->can_id,
1165 REGMASK(op->can_id),
1166 bcm_rx_handler, op,
1167 "bcm");
1168
1169 op->rx_reg_dev = dev;
1170 dev_put(dev);
1171 }
1172
1173 } else
1174 err = can_rx_register(NULL, op->can_id,
1175 REGMASK(op->can_id),
1176 bcm_rx_handler, op, "bcm");
1177 if (err) {
1178 /* this bcm rx op is broken -> remove it */
1179 list_del(&op->list);
1180 bcm_remove_op(op);
1181 return err;
1182 }
1183 }
1184
1185 return msg_head->nframes * CFSIZ + MHSIZ;
1186}
1187
1188/*
1189 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1190 */
1191static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1192{
1193 struct sk_buff *skb;
1194 struct net_device *dev;
1195 int err;
1196
1197 /* we need a real device to send frames */
1198 if (!ifindex)
1199 return -ENODEV;
1200
1201 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1202
1203 if (!skb)
1204 return -ENOMEM;
1205
1206 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1207 if (err < 0) {
1208 kfree_skb(skb);
1209 return err;
1210 }
1211
1212 dev = dev_get_by_index(&init_net, ifindex);
1213 if (!dev) {
1214 kfree_skb(skb);
1215 return -ENODEV;
1216 }
1217
1218 skb->dev = dev;
1219 skb->sk = sk;
1220 err = can_send(skb, 1); /* send with loopback */
1221 dev_put(dev);
1222
1223 if (err)
1224 return err;
1225
1226 return CFSIZ + MHSIZ;
1227}
1228
1229/*
1230 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1231 */
1232static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1233 struct msghdr *msg, size_t size)
1234{
1235 struct sock *sk = sock->sk;
1236 struct bcm_sock *bo = bcm_sk(sk);
1237 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1238 struct bcm_msg_head msg_head;
1239 int ret; /* read bytes or error codes as return value */
1240
1241 if (!bo->bound)
1242 return -ENOTCONN;
1243
1244 /* check for valid message length from userspace */
1245 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1246 return -EINVAL;
1247
1248 /* check for alternative ifindex for this bcm_op */
1249
1250 if (!ifindex && msg->msg_name) {
1251 /* no bound device as default => check msg_name */
1252 struct sockaddr_can *addr =
1253 (struct sockaddr_can *)msg->msg_name;
1254
1255 if (msg->msg_namelen < sizeof(*addr))
1256 return -EINVAL;
1257
1258 if (addr->can_family != AF_CAN)
1259 return -EINVAL;
1260
1261 /* ifindex from sendto() */
1262 ifindex = addr->can_ifindex;
1263
1264 if (ifindex) {
1265 struct net_device *dev;
1266
1267 dev = dev_get_by_index(&init_net, ifindex);
1268 if (!dev)
1269 return -ENODEV;
1270
1271 if (dev->type != ARPHRD_CAN) {
1272 dev_put(dev);
1273 return -ENODEV;
1274 }
1275
1276 dev_put(dev);
1277 }
1278 }
1279
1280 /* read message head information */
1281
1282 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1283 if (ret < 0)
1284 return ret;
1285
1286 lock_sock(sk);
1287
1288 switch (msg_head.opcode) {
1289
1290 case TX_SETUP:
1291 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1292 break;
1293
1294 case RX_SETUP:
1295 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1296 break;
1297
1298 case TX_DELETE:
1299 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1300 ret = MHSIZ;
1301 else
1302 ret = -EINVAL;
1303 break;
1304
1305 case RX_DELETE:
1306 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1307 ret = MHSIZ;
1308 else
1309 ret = -EINVAL;
1310 break;
1311
1312 case TX_READ:
1313 /* reuse msg_head for the reply to TX_READ */
1314 msg_head.opcode = TX_STATUS;
1315 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1316 break;
1317
1318 case RX_READ:
1319 /* reuse msg_head for the reply to RX_READ */
1320 msg_head.opcode = RX_STATUS;
1321 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1322 break;
1323
1324 case TX_SEND:
1325 /* we need exactly one can_frame behind the msg head */
1326 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1327 ret = -EINVAL;
1328 else
1329 ret = bcm_tx_send(msg, ifindex, sk);
1330 break;
1331
1332 default:
1333 ret = -EINVAL;
1334 break;
1335 }
1336
1337 release_sock(sk);
1338
1339 return ret;
1340}
1341
1342/*
1343 * notification handler for netdevice status changes
1344 */
1345static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1346 void *data)
1347{
1348 struct net_device *dev = (struct net_device *)data;
1349 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1350 struct sock *sk = &bo->sk;
1351 struct bcm_op *op;
1352 int notify_enodev = 0;
1353
1354 if (!net_eq(dev_net(dev), &init_net))
1355 return NOTIFY_DONE;
1356
1357 if (dev->type != ARPHRD_CAN)
1358 return NOTIFY_DONE;
1359
1360 switch (msg) {
1361
1362 case NETDEV_UNREGISTER:
1363 lock_sock(sk);
1364
1365 /* remove device specific receive entries */
1366 list_for_each_entry(op, &bo->rx_ops, list)
1367 if (op->rx_reg_dev == dev)
1368 bcm_rx_unreg(dev, op);
1369
1370 /* remove device reference, if this is our bound device */
1371 if (bo->bound && bo->ifindex == dev->ifindex) {
1372 bo->bound = 0;
1373 bo->ifindex = 0;
1374 notify_enodev = 1;
1375 }
1376
1377 release_sock(sk);
1378
1379 if (notify_enodev) {
1380 sk->sk_err = ENODEV;
1381 if (!sock_flag(sk, SOCK_DEAD))
1382 sk->sk_error_report(sk);
1383 }
1384 break;
1385
1386 case NETDEV_DOWN:
1387 if (bo->bound && bo->ifindex == dev->ifindex) {
1388 sk->sk_err = ENETDOWN;
1389 if (!sock_flag(sk, SOCK_DEAD))
1390 sk->sk_error_report(sk);
1391 }
1392 }
1393
1394 return NOTIFY_DONE;
1395}
1396
1397/*
1398 * initial settings for all BCM sockets to be set at socket creation time
1399 */
1400static int bcm_init(struct sock *sk)
1401{
1402 struct bcm_sock *bo = bcm_sk(sk);
1403
1404 bo->bound = 0;
1405 bo->ifindex = 0;
1406 bo->dropped_usr_msgs = 0;
1407 bo->bcm_proc_read = NULL;
1408
1409 INIT_LIST_HEAD(&bo->tx_ops);
1410 INIT_LIST_HEAD(&bo->rx_ops);
1411
1412 /* set notifier */
1413 bo->notifier.notifier_call = bcm_notifier;
1414
1415 register_netdevice_notifier(&bo->notifier);
1416
1417 return 0;
1418}
1419
1420/*
1421 * standard socket functions
1422 */
1423static int bcm_release(struct socket *sock)
1424{
1425 struct sock *sk = sock->sk;
1426 struct bcm_sock *bo;
1427 struct bcm_op *op, *next;
1428
1429 if (sk == NULL)
1430 return 0;
1431
1432 bo = bcm_sk(sk);
1433
1434 /* remove bcm_ops, timer, rx_unregister(), etc. */
1435
1436 unregister_netdevice_notifier(&bo->notifier);
1437
1438 lock_sock(sk);
1439
1440 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1441 bcm_remove_op(op);
1442
1443 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1444 /*
1445 * Don't care if we're bound or not (due to netdev problems)
1446 * can_rx_unregister() is always a save thing to do here.
1447 */
1448 if (op->ifindex) {
1449 /*
1450 * Only remove subscriptions that had not
1451 * been removed due to NETDEV_UNREGISTER
1452 * in bcm_notifier()
1453 */
1454 if (op->rx_reg_dev) {
1455 struct net_device *dev;
1456
1457 dev = dev_get_by_index(&init_net, op->ifindex);
1458 if (dev) {
1459 bcm_rx_unreg(dev, op);
1460 dev_put(dev);
1461 }
1462 }
1463 } else
1464 can_rx_unregister(NULL, op->can_id,
1465 REGMASK(op->can_id),
1466 bcm_rx_handler, op);
1467
1468 bcm_remove_op(op);
1469 }
1470
1471 /* remove procfs entry */
1472 if (proc_dir && bo->bcm_proc_read)
1473 remove_proc_entry(bo->procname, proc_dir);
1474
1475 /* remove device reference */
1476 if (bo->bound) {
1477 bo->bound = 0;
1478 bo->ifindex = 0;
1479 }
1480
1481 sock_orphan(sk);
1482 sock->sk = NULL;
1483
1484 release_sock(sk);
1485 sock_put(sk);
1486
1487 return 0;
1488}
1489
1490static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1491 int flags)
1492{
1493 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1494 struct sock *sk = sock->sk;
1495 struct bcm_sock *bo = bcm_sk(sk);
1496
1497 if (len < sizeof(*addr))
1498 return -EINVAL;
1499
1500 if (bo->bound)
1501 return -EISCONN;
1502
1503 /* bind a device to this socket */
1504 if (addr->can_ifindex) {
1505 struct net_device *dev;
1506
1507 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1508 if (!dev)
1509 return -ENODEV;
1510
1511 if (dev->type != ARPHRD_CAN) {
1512 dev_put(dev);
1513 return -ENODEV;
1514 }
1515
1516 bo->ifindex = dev->ifindex;
1517 dev_put(dev);
1518
1519 } else {
1520 /* no interface reference for ifindex = 0 ('any' CAN device) */
1521 bo->ifindex = 0;
1522 }
1523
1524 bo->bound = 1;
1525
1526 if (proc_dir) {
1527 /* unique socket address as filename */
1528 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1529 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1530 proc_dir,
1531 &bcm_proc_fops, sk);
1532 }
1533
1534 return 0;
1535}
1536
1537static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1538 struct msghdr *msg, size_t size, int flags)
1539{
1540 struct sock *sk = sock->sk;
1541 struct sk_buff *skb;
1542 int error = 0;
1543 int noblock;
1544 int err;
1545
1546 noblock = flags & MSG_DONTWAIT;
1547 flags &= ~MSG_DONTWAIT;
1548 skb = skb_recv_datagram(sk, flags, noblock, &error);
1549 if (!skb)
1550 return error;
1551
1552 if (skb->len < size)
1553 size = skb->len;
1554
1555 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1556 if (err < 0) {
1557 skb_free_datagram(sk, skb);
1558 return err;
1559 }
1560
1561 sock_recv_ts_and_drops(msg, sk, skb);
1562
1563 if (msg->msg_name) {
1564 msg->msg_namelen = sizeof(struct sockaddr_can);
1565 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1566 }
1567
1568 skb_free_datagram(sk, skb);
1569
1570 return size;
1571}
1572
1573static const struct proto_ops bcm_ops = {
1574 .family = PF_CAN,
1575 .release = bcm_release,
1576 .bind = sock_no_bind,
1577 .connect = bcm_connect,
1578 .socketpair = sock_no_socketpair,
1579 .accept = sock_no_accept,
1580 .getname = sock_no_getname,
1581 .poll = datagram_poll,
1582 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1583 .listen = sock_no_listen,
1584 .shutdown = sock_no_shutdown,
1585 .setsockopt = sock_no_setsockopt,
1586 .getsockopt = sock_no_getsockopt,
1587 .sendmsg = bcm_sendmsg,
1588 .recvmsg = bcm_recvmsg,
1589 .mmap = sock_no_mmap,
1590 .sendpage = sock_no_sendpage,
1591};
1592
1593static struct proto bcm_proto __read_mostly = {
1594 .name = "CAN_BCM",
1595 .owner = THIS_MODULE,
1596 .obj_size = sizeof(struct bcm_sock),
1597 .init = bcm_init,
1598};
1599
1600static const struct can_proto bcm_can_proto = {
1601 .type = SOCK_DGRAM,
1602 .protocol = CAN_BCM,
1603 .ops = &bcm_ops,
1604 .prot = &bcm_proto,
1605};
1606
1607static int __init bcm_module_init(void)
1608{
1609 int err;
1610
1611 printk(banner);
1612
1613 err = can_proto_register(&bcm_can_proto);
1614 if (err < 0) {
1615 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1616 return err;
1617 }
1618
1619 /* create /proc/net/can-bcm directory */
1620 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1621 return 0;
1622}
1623
1624static void __exit bcm_module_exit(void)
1625{
1626 can_proto_unregister(&bcm_can_proto);
1627
1628 if (proc_dir)
1629 proc_net_remove(&init_net, "can-bcm");
1630}
1631
1632module_init(bcm_module_init);
1633module_exit(bcm_module_exit);