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
80 static __initdata const char banner[] = KERN_INFO
81 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
82
83 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
84 MODULE_LICENSE("Dual BSD/GPL");
85 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
86 MODULE_ALIAS("can-proto-2");
87
88 /* easy access to can_frame payload */
GET_U64(const struct can_frame * cp)89 static inline u64 GET_U64(const struct can_frame *cp)
90 {
91 return *(u64 *)cp->data;
92 }
93
94 struct 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
116 static struct proc_dir_entry *proc_dir;
117
118 struct 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
bcm_sk(const struct sock * sk)130 static 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 */
bcm_proc_getifname(char * result,int ifindex)142 static 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
bcm_proc_show(struct seq_file * m,void * v)160 static 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
bcm_proc_open(struct inode * inode,struct file * file)226 static int bcm_proc_open(struct inode *inode, struct file *file)
227 {
228 return single_open(file, bcm_proc_show, PDE(inode)->data);
229 }
230
231 static 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 */
bcm_can_tx(struct bcm_op * op)243 static 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 */
bcm_send_to_user(struct bcm_op * op,struct bcm_msg_head * head,struct can_frame * frames,int has_timestamp)285 static 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
bcm_tx_start_timer(struct bcm_op * op)345 static 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
bcm_tx_timeout_tsklet(unsigned long data)357 static 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 */
bcm_tx_timeout_handler(struct hrtimer * hrtimer)389 static 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 */
bcm_rx_changed(struct bcm_op * op,struct can_frame * data)401 static 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 */
bcm_rx_update_and_send(struct bcm_op * op,struct can_frame * lastdata,const struct can_frame * rxdata)431 static 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 */
466 rx_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 */
bcm_rx_cmp_to_index(struct bcm_op * op,unsigned int index,const struct can_frame * rxdata)475 static 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 */
bcm_rx_starttimer(struct bcm_op * op)511 static 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
bcm_rx_timeout_tsklet(unsigned long data)520 static 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 */
bcm_rx_timeout_handler(struct hrtimer * hrtimer)540 static 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 */
bcm_rx_do_flush(struct bcm_op * op,int update,unsigned int index)561 static 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 */
bcm_rx_thr_flush(struct bcm_op * op,int update)578 static 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
bcm_rx_thr_tsklet(unsigned long data)597 static 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 */
bcm_rx_thr_handler(struct hrtimer * hrtimer)609 static 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 */
bcm_rx_handler(struct sk_buff * skb,void * data)628 static 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
683 rx_starttimer:
684 bcm_rx_starttimer(op);
685 }
686
687 /*
688 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
689 */
bcm_find_op(struct list_head * ops,canid_t can_id,int ifindex)690 static 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
bcm_remove_op(struct bcm_op * op)703 static 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
bcm_rx_unreg(struct net_device * dev,struct bcm_op * op)723 static 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 */
bcm_delete_rx_op(struct list_head * ops,canid_t can_id,int ifindex)739 static 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 */
bcm_delete_tx_op(struct list_head * ops,canid_t can_id,int ifindex)784 static 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 */
bcm_read_op(struct list_head * ops,struct bcm_msg_head * msg_head,int ifindex)802 static 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 */
bcm_tx_setup(struct bcm_msg_head * msg_head,struct msghdr * msg,int ifindex,struct sock * sk)825 static 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 */
bcm_rx_setup(struct bcm_msg_head * msg_head,struct msghdr * msg,int ifindex,struct sock * sk)984 static 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 /* ifindex for timeout events w/o previous frame reception */
1088 op->rx_ifindex = ifindex;
1089
1090 /* initialize uninitialized (kzalloc) structure */
1091 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1092 op->timer.function = bcm_rx_timeout_handler;
1093
1094 /* initialize tasklet for rx timeout notification */
1095 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1096 (unsigned long) op);
1097
1098 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1099 op->thrtimer.function = bcm_rx_thr_handler;
1100
1101 /* initialize tasklet for rx throttle handling */
1102 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1103 (unsigned long) op);
1104
1105 /* add this bcm_op to the list of the rx_ops */
1106 list_add(&op->list, &bo->rx_ops);
1107
1108 /* call can_rx_register() */
1109 do_rx_register = 1;
1110
1111 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1112
1113 /* check flags */
1114 op->flags = msg_head->flags;
1115
1116 if (op->flags & RX_RTR_FRAME) {
1117
1118 /* no timers in RTR-mode */
1119 hrtimer_cancel(&op->thrtimer);
1120 hrtimer_cancel(&op->timer);
1121
1122 /*
1123 * funny feature in RX(!)_SETUP only for RTR-mode:
1124 * copy can_id into frame BUT without RTR-flag to
1125 * prevent a full-load-loopback-test ... ;-]
1126 */
1127 if ((op->flags & TX_CP_CAN_ID) ||
1128 (op->frames[0].can_id == op->can_id))
1129 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1130
1131 } else {
1132 if (op->flags & SETTIMER) {
1133
1134 /* set timer value */
1135 op->ival1 = msg_head->ival1;
1136 op->ival2 = msg_head->ival2;
1137 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1138 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1139
1140 /* disable an active timer due to zero value? */
1141 if (!op->kt_ival1.tv64)
1142 hrtimer_cancel(&op->timer);
1143
1144 /*
1145 * In any case cancel the throttle timer, flush
1146 * potentially blocked msgs and reset throttle handling
1147 */
1148 op->kt_lastmsg = ktime_set(0, 0);
1149 hrtimer_cancel(&op->thrtimer);
1150 bcm_rx_thr_flush(op, 1);
1151 }
1152
1153 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1154 hrtimer_start(&op->timer, op->kt_ival1,
1155 HRTIMER_MODE_REL);
1156 }
1157
1158 /* now we can register for can_ids, if we added a new bcm_op */
1159 if (do_rx_register) {
1160 if (ifindex) {
1161 struct net_device *dev;
1162
1163 dev = dev_get_by_index(&init_net, ifindex);
1164 if (dev) {
1165 err = can_rx_register(dev, op->can_id,
1166 REGMASK(op->can_id),
1167 bcm_rx_handler, op,
1168 "bcm");
1169
1170 op->rx_reg_dev = dev;
1171 dev_put(dev);
1172 }
1173
1174 } else
1175 err = can_rx_register(NULL, op->can_id,
1176 REGMASK(op->can_id),
1177 bcm_rx_handler, op, "bcm");
1178 if (err) {
1179 /* this bcm rx op is broken -> remove it */
1180 list_del(&op->list);
1181 bcm_remove_op(op);
1182 return err;
1183 }
1184 }
1185
1186 return msg_head->nframes * CFSIZ + MHSIZ;
1187 }
1188
1189 /*
1190 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1191 */
bcm_tx_send(struct msghdr * msg,int ifindex,struct sock * sk)1192 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1193 {
1194 struct sk_buff *skb;
1195 struct net_device *dev;
1196 int err;
1197
1198 /* we need a real device to send frames */
1199 if (!ifindex)
1200 return -ENODEV;
1201
1202 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1203
1204 if (!skb)
1205 return -ENOMEM;
1206
1207 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1208 if (err < 0) {
1209 kfree_skb(skb);
1210 return err;
1211 }
1212
1213 dev = dev_get_by_index(&init_net, ifindex);
1214 if (!dev) {
1215 kfree_skb(skb);
1216 return -ENODEV;
1217 }
1218
1219 skb->dev = dev;
1220 skb->sk = sk;
1221 err = can_send(skb, 1); /* send with loopback */
1222 dev_put(dev);
1223
1224 if (err)
1225 return err;
1226
1227 return CFSIZ + MHSIZ;
1228 }
1229
1230 /*
1231 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1232 */
bcm_sendmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size)1233 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1234 struct msghdr *msg, size_t size)
1235 {
1236 struct sock *sk = sock->sk;
1237 struct bcm_sock *bo = bcm_sk(sk);
1238 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1239 struct bcm_msg_head msg_head;
1240 int ret; /* read bytes or error codes as return value */
1241
1242 if (!bo->bound)
1243 return -ENOTCONN;
1244
1245 /* check for valid message length from userspace */
1246 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1247 return -EINVAL;
1248
1249 /* check for alternative ifindex for this bcm_op */
1250
1251 if (!ifindex && msg->msg_name) {
1252 /* no bound device as default => check msg_name */
1253 struct sockaddr_can *addr =
1254 (struct sockaddr_can *)msg->msg_name;
1255
1256 if (msg->msg_namelen < sizeof(*addr))
1257 return -EINVAL;
1258
1259 if (addr->can_family != AF_CAN)
1260 return -EINVAL;
1261
1262 /* ifindex from sendto() */
1263 ifindex = addr->can_ifindex;
1264
1265 if (ifindex) {
1266 struct net_device *dev;
1267
1268 dev = dev_get_by_index(&init_net, ifindex);
1269 if (!dev)
1270 return -ENODEV;
1271
1272 if (dev->type != ARPHRD_CAN) {
1273 dev_put(dev);
1274 return -ENODEV;
1275 }
1276
1277 dev_put(dev);
1278 }
1279 }
1280
1281 /* read message head information */
1282
1283 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1284 if (ret < 0)
1285 return ret;
1286
1287 lock_sock(sk);
1288
1289 switch (msg_head.opcode) {
1290
1291 case TX_SETUP:
1292 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1293 break;
1294
1295 case RX_SETUP:
1296 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1297 break;
1298
1299 case TX_DELETE:
1300 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1301 ret = MHSIZ;
1302 else
1303 ret = -EINVAL;
1304 break;
1305
1306 case RX_DELETE:
1307 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1308 ret = MHSIZ;
1309 else
1310 ret = -EINVAL;
1311 break;
1312
1313 case TX_READ:
1314 /* reuse msg_head for the reply to TX_READ */
1315 msg_head.opcode = TX_STATUS;
1316 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1317 break;
1318
1319 case RX_READ:
1320 /* reuse msg_head for the reply to RX_READ */
1321 msg_head.opcode = RX_STATUS;
1322 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1323 break;
1324
1325 case TX_SEND:
1326 /* we need exactly one can_frame behind the msg head */
1327 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1328 ret = -EINVAL;
1329 else
1330 ret = bcm_tx_send(msg, ifindex, sk);
1331 break;
1332
1333 default:
1334 ret = -EINVAL;
1335 break;
1336 }
1337
1338 release_sock(sk);
1339
1340 return ret;
1341 }
1342
1343 /*
1344 * notification handler for netdevice status changes
1345 */
bcm_notifier(struct notifier_block * nb,unsigned long msg,void * data)1346 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1347 void *data)
1348 {
1349 struct net_device *dev = (struct net_device *)data;
1350 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1351 struct sock *sk = &bo->sk;
1352 struct bcm_op *op;
1353 int notify_enodev = 0;
1354
1355 if (!net_eq(dev_net(dev), &init_net))
1356 return NOTIFY_DONE;
1357
1358 if (dev->type != ARPHRD_CAN)
1359 return NOTIFY_DONE;
1360
1361 switch (msg) {
1362
1363 case NETDEV_UNREGISTER:
1364 lock_sock(sk);
1365
1366 /* remove device specific receive entries */
1367 list_for_each_entry(op, &bo->rx_ops, list)
1368 if (op->rx_reg_dev == dev)
1369 bcm_rx_unreg(dev, op);
1370
1371 /* remove device reference, if this is our bound device */
1372 if (bo->bound && bo->ifindex == dev->ifindex) {
1373 bo->bound = 0;
1374 bo->ifindex = 0;
1375 notify_enodev = 1;
1376 }
1377
1378 release_sock(sk);
1379
1380 if (notify_enodev) {
1381 sk->sk_err = ENODEV;
1382 if (!sock_flag(sk, SOCK_DEAD))
1383 sk->sk_error_report(sk);
1384 }
1385 break;
1386
1387 case NETDEV_DOWN:
1388 if (bo->bound && bo->ifindex == dev->ifindex) {
1389 sk->sk_err = ENETDOWN;
1390 if (!sock_flag(sk, SOCK_DEAD))
1391 sk->sk_error_report(sk);
1392 }
1393 }
1394
1395 return NOTIFY_DONE;
1396 }
1397
1398 /*
1399 * initial settings for all BCM sockets to be set at socket creation time
1400 */
bcm_init(struct sock * sk)1401 static int bcm_init(struct sock *sk)
1402 {
1403 struct bcm_sock *bo = bcm_sk(sk);
1404
1405 bo->bound = 0;
1406 bo->ifindex = 0;
1407 bo->dropped_usr_msgs = 0;
1408 bo->bcm_proc_read = NULL;
1409
1410 INIT_LIST_HEAD(&bo->tx_ops);
1411 INIT_LIST_HEAD(&bo->rx_ops);
1412
1413 /* set notifier */
1414 bo->notifier.notifier_call = bcm_notifier;
1415
1416 register_netdevice_notifier(&bo->notifier);
1417
1418 return 0;
1419 }
1420
1421 /*
1422 * standard socket functions
1423 */
bcm_release(struct socket * sock)1424 static int bcm_release(struct socket *sock)
1425 {
1426 struct sock *sk = sock->sk;
1427 struct bcm_sock *bo;
1428 struct bcm_op *op, *next;
1429
1430 if (sk == NULL)
1431 return 0;
1432
1433 bo = bcm_sk(sk);
1434
1435 /* remove bcm_ops, timer, rx_unregister(), etc. */
1436
1437 unregister_netdevice_notifier(&bo->notifier);
1438
1439 lock_sock(sk);
1440
1441 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1442 bcm_remove_op(op);
1443
1444 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1445 /*
1446 * Don't care if we're bound or not (due to netdev problems)
1447 * can_rx_unregister() is always a save thing to do here.
1448 */
1449 if (op->ifindex) {
1450 /*
1451 * Only remove subscriptions that had not
1452 * been removed due to NETDEV_UNREGISTER
1453 * in bcm_notifier()
1454 */
1455 if (op->rx_reg_dev) {
1456 struct net_device *dev;
1457
1458 dev = dev_get_by_index(&init_net, op->ifindex);
1459 if (dev) {
1460 bcm_rx_unreg(dev, op);
1461 dev_put(dev);
1462 }
1463 }
1464 } else
1465 can_rx_unregister(NULL, op->can_id,
1466 REGMASK(op->can_id),
1467 bcm_rx_handler, op);
1468
1469 bcm_remove_op(op);
1470 }
1471
1472 /* remove procfs entry */
1473 if (proc_dir && bo->bcm_proc_read)
1474 remove_proc_entry(bo->procname, proc_dir);
1475
1476 /* remove device reference */
1477 if (bo->bound) {
1478 bo->bound = 0;
1479 bo->ifindex = 0;
1480 }
1481
1482 sock_orphan(sk);
1483 sock->sk = NULL;
1484
1485 release_sock(sk);
1486 sock_put(sk);
1487
1488 return 0;
1489 }
1490
bcm_connect(struct socket * sock,struct sockaddr * uaddr,int len,int flags)1491 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1492 int flags)
1493 {
1494 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1495 struct sock *sk = sock->sk;
1496 struct bcm_sock *bo = bcm_sk(sk);
1497
1498 if (len < sizeof(*addr))
1499 return -EINVAL;
1500
1501 if (bo->bound)
1502 return -EISCONN;
1503
1504 /* bind a device to this socket */
1505 if (addr->can_ifindex) {
1506 struct net_device *dev;
1507
1508 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1509 if (!dev)
1510 return -ENODEV;
1511
1512 if (dev->type != ARPHRD_CAN) {
1513 dev_put(dev);
1514 return -ENODEV;
1515 }
1516
1517 bo->ifindex = dev->ifindex;
1518 dev_put(dev);
1519
1520 } else {
1521 /* no interface reference for ifindex = 0 ('any' CAN device) */
1522 bo->ifindex = 0;
1523 }
1524
1525 bo->bound = 1;
1526
1527 if (proc_dir) {
1528 /* unique socket address as filename */
1529 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1530 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1531 proc_dir,
1532 &bcm_proc_fops, sk);
1533 }
1534
1535 return 0;
1536 }
1537
bcm_recvmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size,int flags)1538 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1539 struct msghdr *msg, size_t size, int flags)
1540 {
1541 struct sock *sk = sock->sk;
1542 struct sk_buff *skb;
1543 int error = 0;
1544 int noblock;
1545 int err;
1546
1547 noblock = flags & MSG_DONTWAIT;
1548 flags &= ~MSG_DONTWAIT;
1549 skb = skb_recv_datagram(sk, flags, noblock, &error);
1550 if (!skb)
1551 return error;
1552
1553 if (skb->len < size)
1554 size = skb->len;
1555
1556 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1557 if (err < 0) {
1558 skb_free_datagram(sk, skb);
1559 return err;
1560 }
1561
1562 sock_recv_ts_and_drops(msg, sk, skb);
1563
1564 if (msg->msg_name) {
1565 msg->msg_namelen = sizeof(struct sockaddr_can);
1566 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1567 }
1568
1569 skb_free_datagram(sk, skb);
1570
1571 return size;
1572 }
1573
1574 static const struct proto_ops bcm_ops = {
1575 .family = PF_CAN,
1576 .release = bcm_release,
1577 .bind = sock_no_bind,
1578 .connect = bcm_connect,
1579 .socketpair = sock_no_socketpair,
1580 .accept = sock_no_accept,
1581 .getname = sock_no_getname,
1582 .poll = datagram_poll,
1583 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1584 .listen = sock_no_listen,
1585 .shutdown = sock_no_shutdown,
1586 .setsockopt = sock_no_setsockopt,
1587 .getsockopt = sock_no_getsockopt,
1588 .sendmsg = bcm_sendmsg,
1589 .recvmsg = bcm_recvmsg,
1590 .mmap = sock_no_mmap,
1591 .sendpage = sock_no_sendpage,
1592 };
1593
1594 static struct proto bcm_proto __read_mostly = {
1595 .name = "CAN_BCM",
1596 .owner = THIS_MODULE,
1597 .obj_size = sizeof(struct bcm_sock),
1598 .init = bcm_init,
1599 };
1600
1601 static const struct can_proto bcm_can_proto = {
1602 .type = SOCK_DGRAM,
1603 .protocol = CAN_BCM,
1604 .ops = &bcm_ops,
1605 .prot = &bcm_proto,
1606 };
1607
bcm_module_init(void)1608 static int __init bcm_module_init(void)
1609 {
1610 int err;
1611
1612 printk(banner);
1613
1614 err = can_proto_register(&bcm_can_proto);
1615 if (err < 0) {
1616 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1617 return err;
1618 }
1619
1620 /* create /proc/net/can-bcm directory */
1621 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1622 return 0;
1623 }
1624
bcm_module_exit(void)1625 static void __exit bcm_module_exit(void)
1626 {
1627 can_proto_unregister(&bcm_can_proto);
1628
1629 if (proc_dir)
1630 proc_net_remove(&init_net, "can-bcm");
1631 }
1632
1633 module_init(bcm_module_init);
1634 module_exit(bcm_module_exit);
1635