Loading...
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// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2/*
3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 *
5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of Volkswagen nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * Alternatively, provided that this notice is retained in full, this
21 * software may be distributed under the terms of the GNU General
22 * Public License ("GPL") version 2, in which case the provisions of the
23 * GPL apply INSTEAD OF those given above.
24 *
25 * The provided data structures and external interfaces from this code
26 * are not restricted to be used by modules with a GPL compatible license.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
39 * DAMAGE.
40 *
41 */
42
43#include <linux/module.h>
44#include <linux/init.h>
45#include <linux/interrupt.h>
46#include <linux/hrtimer.h>
47#include <linux/list.h>
48#include <linux/proc_fs.h>
49#include <linux/seq_file.h>
50#include <linux/uio.h>
51#include <linux/net.h>
52#include <linux/netdevice.h>
53#include <linux/socket.h>
54#include <linux/if_arp.h>
55#include <linux/skbuff.h>
56#include <linux/can.h>
57#include <linux/can/core.h>
58#include <linux/can/skb.h>
59#include <linux/can/bcm.h>
60#include <linux/slab.h>
61#include <net/sock.h>
62#include <net/net_namespace.h>
63
64/*
65 * To send multiple CAN frame content within TX_SETUP or to filter
66 * CAN messages with multiplex index within RX_SETUP, the number of
67 * different filters is limited to 256 due to the one byte index value.
68 */
69#define MAX_NFRAMES 256
70
71/* limit timers to 400 days for sending/timeouts */
72#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
73
74/* use of last_frames[index].flags */
75#define RX_RECV 0x40 /* received data for this element */
76#define RX_THR 0x80 /* element not been sent due to throttle feature */
77#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
78
79/* get best masking value for can_rx_register() for a given single can_id */
80#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
81 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
82 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
83
84MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
85MODULE_LICENSE("Dual BSD/GPL");
86MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
87MODULE_ALIAS("can-proto-2");
88
89#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
90
91/*
92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
95 */
96static inline u64 get_u64(const struct canfd_frame *cp, int offset)
97{
98 return *(u64 *)(cp->data + offset);
99}
100
101struct bcm_op {
102 struct list_head list;
103 struct rcu_head rcu;
104 int ifindex;
105 canid_t can_id;
106 u32 flags;
107 unsigned long frames_abs, frames_filtered;
108 struct bcm_timeval ival1, ival2;
109 struct hrtimer timer, thrtimer;
110 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
111 int rx_ifindex;
112 int cfsiz;
113 u32 count;
114 u32 nframes;
115 u32 currframe;
116 /* void pointers to arrays of struct can[fd]_frame */
117 void *frames;
118 void *last_frames;
119 struct canfd_frame sframe;
120 struct canfd_frame last_sframe;
121 struct sock *sk;
122 struct net_device *rx_reg_dev;
123};
124
125struct bcm_sock {
126 struct sock sk;
127 int bound;
128 int ifindex;
129 struct list_head notifier;
130 struct list_head rx_ops;
131 struct list_head tx_ops;
132 unsigned long dropped_usr_msgs;
133 struct proc_dir_entry *bcm_proc_read;
134 char procname [32]; /* inode number in decimal with \0 */
135};
136
137static LIST_HEAD(bcm_notifier_list);
138static DEFINE_SPINLOCK(bcm_notifier_lock);
139static struct bcm_sock *bcm_busy_notifier;
140
141static inline struct bcm_sock *bcm_sk(const struct sock *sk)
142{
143 return (struct bcm_sock *)sk;
144}
145
146static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
147{
148 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
149}
150
151/* check limitations for timeval provided by user */
152static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
153{
154 if ((msg_head->ival1.tv_sec < 0) ||
155 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
156 (msg_head->ival1.tv_usec < 0) ||
157 (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
158 (msg_head->ival2.tv_sec < 0) ||
159 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
160 (msg_head->ival2.tv_usec < 0) ||
161 (msg_head->ival2.tv_usec >= USEC_PER_SEC))
162 return true;
163
164 return false;
165}
166
167#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
168#define OPSIZ sizeof(struct bcm_op)
169#define MHSIZ sizeof(struct bcm_msg_head)
170
171/*
172 * procfs functions
173 */
174#if IS_ENABLED(CONFIG_PROC_FS)
175static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
176{
177 struct net_device *dev;
178
179 if (!ifindex)
180 return "any";
181
182 rcu_read_lock();
183 dev = dev_get_by_index_rcu(net, ifindex);
184 if (dev)
185 strcpy(result, dev->name);
186 else
187 strcpy(result, "???");
188 rcu_read_unlock();
189
190 return result;
191}
192
193static int bcm_proc_show(struct seq_file *m, void *v)
194{
195 char ifname[IFNAMSIZ];
196 struct net *net = m->private;
197 struct sock *sk = (struct sock *)pde_data(m->file->f_inode);
198 struct bcm_sock *bo = bcm_sk(sk);
199 struct bcm_op *op;
200
201 seq_printf(m, ">>> socket %pK", sk->sk_socket);
202 seq_printf(m, " / sk %pK", sk);
203 seq_printf(m, " / bo %pK", bo);
204 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
205 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
206 seq_printf(m, " <<<\n");
207
208 list_for_each_entry(op, &bo->rx_ops, list) {
209
210 unsigned long reduction;
211
212 /* print only active entries & prevent division by zero */
213 if (!op->frames_abs)
214 continue;
215
216 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
217 bcm_proc_getifname(net, ifname, op->ifindex));
218
219 if (op->flags & CAN_FD_FRAME)
220 seq_printf(m, "(%u)", op->nframes);
221 else
222 seq_printf(m, "[%u]", op->nframes);
223
224 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
225
226 if (op->kt_ival1)
227 seq_printf(m, "timeo=%lld ",
228 (long long)ktime_to_us(op->kt_ival1));
229
230 if (op->kt_ival2)
231 seq_printf(m, "thr=%lld ",
232 (long long)ktime_to_us(op->kt_ival2));
233
234 seq_printf(m, "# recv %ld (%ld) => reduction: ",
235 op->frames_filtered, op->frames_abs);
236
237 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
238
239 seq_printf(m, "%s%ld%%\n",
240 (reduction == 100) ? "near " : "", reduction);
241 }
242
243 list_for_each_entry(op, &bo->tx_ops, list) {
244
245 seq_printf(m, "tx_op: %03X %s ", op->can_id,
246 bcm_proc_getifname(net, ifname, op->ifindex));
247
248 if (op->flags & CAN_FD_FRAME)
249 seq_printf(m, "(%u) ", op->nframes);
250 else
251 seq_printf(m, "[%u] ", op->nframes);
252
253 if (op->kt_ival1)
254 seq_printf(m, "t1=%lld ",
255 (long long)ktime_to_us(op->kt_ival1));
256
257 if (op->kt_ival2)
258 seq_printf(m, "t2=%lld ",
259 (long long)ktime_to_us(op->kt_ival2));
260
261 seq_printf(m, "# sent %ld\n", op->frames_abs);
262 }
263 seq_putc(m, '\n');
264 return 0;
265}
266#endif /* CONFIG_PROC_FS */
267
268/*
269 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
270 * of the given bcm tx op
271 */
272static void bcm_can_tx(struct bcm_op *op)
273{
274 struct sk_buff *skb;
275 struct net_device *dev;
276 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
277 int err;
278
279 /* no target device? => exit */
280 if (!op->ifindex)
281 return;
282
283 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
284 if (!dev) {
285 /* RFC: should this bcm_op remove itself here? */
286 return;
287 }
288
289 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
290 if (!skb)
291 goto out;
292
293 can_skb_reserve(skb);
294 can_skb_prv(skb)->ifindex = dev->ifindex;
295 can_skb_prv(skb)->skbcnt = 0;
296
297 skb_put_data(skb, cf, op->cfsiz);
298
299 /* send with loopback */
300 skb->dev = dev;
301 can_skb_set_owner(skb, op->sk);
302 err = can_send(skb, 1);
303 if (!err)
304 op->frames_abs++;
305
306 op->currframe++;
307
308 /* reached last frame? */
309 if (op->currframe >= op->nframes)
310 op->currframe = 0;
311out:
312 dev_put(dev);
313}
314
315/*
316 * bcm_send_to_user - send a BCM message to the userspace
317 * (consisting of bcm_msg_head + x CAN frames)
318 */
319static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
320 struct canfd_frame *frames, int has_timestamp)
321{
322 struct sk_buff *skb;
323 struct canfd_frame *firstframe;
324 struct sockaddr_can *addr;
325 struct sock *sk = op->sk;
326 unsigned int datalen = head->nframes * op->cfsiz;
327 int err;
328
329 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
330 if (!skb)
331 return;
332
333 skb_put_data(skb, head, sizeof(*head));
334
335 if (head->nframes) {
336 /* CAN frames starting here */
337 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
338
339 skb_put_data(skb, frames, datalen);
340
341 /*
342 * the BCM uses the flags-element of the canfd_frame
343 * structure for internal purposes. This is only
344 * relevant for updates that are generated by the
345 * BCM, where nframes is 1
346 */
347 if (head->nframes == 1)
348 firstframe->flags &= BCM_CAN_FLAGS_MASK;
349 }
350
351 if (has_timestamp) {
352 /* restore rx timestamp */
353 skb->tstamp = op->rx_stamp;
354 }
355
356 /*
357 * Put the datagram to the queue so that bcm_recvmsg() can
358 * get it from there. We need to pass the interface index to
359 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
360 * containing the interface index.
361 */
362
363 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
364 addr = (struct sockaddr_can *)skb->cb;
365 memset(addr, 0, sizeof(*addr));
366 addr->can_family = AF_CAN;
367 addr->can_ifindex = op->rx_ifindex;
368
369 err = sock_queue_rcv_skb(sk, skb);
370 if (err < 0) {
371 struct bcm_sock *bo = bcm_sk(sk);
372
373 kfree_skb(skb);
374 /* don't care about overflows in this statistic */
375 bo->dropped_usr_msgs++;
376 }
377}
378
379static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
380{
381 ktime_t ival;
382
383 if (op->kt_ival1 && op->count)
384 ival = op->kt_ival1;
385 else if (op->kt_ival2)
386 ival = op->kt_ival2;
387 else
388 return false;
389
390 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
391 return true;
392}
393
394static void bcm_tx_start_timer(struct bcm_op *op)
395{
396 if (bcm_tx_set_expiry(op, &op->timer))
397 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
398}
399
400/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
401static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
402{
403 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
404 struct bcm_msg_head msg_head;
405
406 if (op->kt_ival1 && (op->count > 0)) {
407 op->count--;
408 if (!op->count && (op->flags & TX_COUNTEVT)) {
409
410 /* create notification to user */
411 memset(&msg_head, 0, sizeof(msg_head));
412 msg_head.opcode = TX_EXPIRED;
413 msg_head.flags = op->flags;
414 msg_head.count = op->count;
415 msg_head.ival1 = op->ival1;
416 msg_head.ival2 = op->ival2;
417 msg_head.can_id = op->can_id;
418 msg_head.nframes = 0;
419
420 bcm_send_to_user(op, &msg_head, NULL, 0);
421 }
422 bcm_can_tx(op);
423
424 } else if (op->kt_ival2) {
425 bcm_can_tx(op);
426 }
427
428 return bcm_tx_set_expiry(op, &op->timer) ?
429 HRTIMER_RESTART : HRTIMER_NORESTART;
430}
431
432/*
433 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
434 */
435static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
436{
437 struct bcm_msg_head head;
438
439 /* update statistics */
440 op->frames_filtered++;
441
442 /* prevent statistics overflow */
443 if (op->frames_filtered > ULONG_MAX/100)
444 op->frames_filtered = op->frames_abs = 0;
445
446 /* this element is not throttled anymore */
447 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
448
449 memset(&head, 0, sizeof(head));
450 head.opcode = RX_CHANGED;
451 head.flags = op->flags;
452 head.count = op->count;
453 head.ival1 = op->ival1;
454 head.ival2 = op->ival2;
455 head.can_id = op->can_id;
456 head.nframes = 1;
457
458 bcm_send_to_user(op, &head, data, 1);
459}
460
461/*
462 * bcm_rx_update_and_send - process a detected relevant receive content change
463 * 1. update the last received data
464 * 2. send a notification to the user (if possible)
465 */
466static void bcm_rx_update_and_send(struct bcm_op *op,
467 struct canfd_frame *lastdata,
468 const struct canfd_frame *rxdata)
469{
470 memcpy(lastdata, rxdata, op->cfsiz);
471
472 /* mark as used and throttled by default */
473 lastdata->flags |= (RX_RECV|RX_THR);
474
475 /* throttling mode inactive ? */
476 if (!op->kt_ival2) {
477 /* send RX_CHANGED to the user immediately */
478 bcm_rx_changed(op, lastdata);
479 return;
480 }
481
482 /* with active throttling timer we are just done here */
483 if (hrtimer_active(&op->thrtimer))
484 return;
485
486 /* first reception with enabled throttling mode */
487 if (!op->kt_lastmsg)
488 goto rx_changed_settime;
489
490 /* got a second frame inside a potential throttle period? */
491 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
492 ktime_to_us(op->kt_ival2)) {
493 /* do not send the saved data - only start throttle timer */
494 hrtimer_start(&op->thrtimer,
495 ktime_add(op->kt_lastmsg, op->kt_ival2),
496 HRTIMER_MODE_ABS_SOFT);
497 return;
498 }
499
500 /* the gap was that big, that throttling was not needed here */
501rx_changed_settime:
502 bcm_rx_changed(op, lastdata);
503 op->kt_lastmsg = ktime_get();
504}
505
506/*
507 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
508 * received data stored in op->last_frames[]
509 */
510static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
511 const struct canfd_frame *rxdata)
512{
513 struct canfd_frame *cf = op->frames + op->cfsiz * index;
514 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
515 int i;
516
517 /*
518 * no one uses the MSBs of flags for comparison,
519 * so we use it here to detect the first time of reception
520 */
521
522 if (!(lcf->flags & RX_RECV)) {
523 /* received data for the first time => send update to user */
524 bcm_rx_update_and_send(op, lcf, rxdata);
525 return;
526 }
527
528 /* do a real check in CAN frame data section */
529 for (i = 0; i < rxdata->len; i += 8) {
530 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
531 (get_u64(cf, i) & get_u64(lcf, i))) {
532 bcm_rx_update_and_send(op, lcf, rxdata);
533 return;
534 }
535 }
536
537 if (op->flags & RX_CHECK_DLC) {
538 /* do a real check in CAN frame length */
539 if (rxdata->len != lcf->len) {
540 bcm_rx_update_and_send(op, lcf, rxdata);
541 return;
542 }
543 }
544}
545
546/*
547 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
548 */
549static void bcm_rx_starttimer(struct bcm_op *op)
550{
551 if (op->flags & RX_NO_AUTOTIMER)
552 return;
553
554 if (op->kt_ival1)
555 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
556}
557
558/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
559static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
560{
561 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
562 struct bcm_msg_head msg_head;
563
564 /* if user wants to be informed, when cyclic CAN-Messages come back */
565 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
566 /* clear received CAN frames to indicate 'nothing received' */
567 memset(op->last_frames, 0, op->nframes * op->cfsiz);
568 }
569
570 /* create notification to user */
571 memset(&msg_head, 0, sizeof(msg_head));
572 msg_head.opcode = RX_TIMEOUT;
573 msg_head.flags = op->flags;
574 msg_head.count = op->count;
575 msg_head.ival1 = op->ival1;
576 msg_head.ival2 = op->ival2;
577 msg_head.can_id = op->can_id;
578 msg_head.nframes = 0;
579
580 bcm_send_to_user(op, &msg_head, NULL, 0);
581
582 return HRTIMER_NORESTART;
583}
584
585/*
586 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
587 */
588static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
589{
590 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
591
592 if ((op->last_frames) && (lcf->flags & RX_THR)) {
593 bcm_rx_changed(op, lcf);
594 return 1;
595 }
596 return 0;
597}
598
599/*
600 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
601 */
602static int bcm_rx_thr_flush(struct bcm_op *op)
603{
604 int updated = 0;
605
606 if (op->nframes > 1) {
607 unsigned int i;
608
609 /* for MUX filter we start at index 1 */
610 for (i = 1; i < op->nframes; i++)
611 updated += bcm_rx_do_flush(op, i);
612
613 } else {
614 /* for RX_FILTER_ID and simple filter */
615 updated += bcm_rx_do_flush(op, 0);
616 }
617
618 return updated;
619}
620
621/*
622 * bcm_rx_thr_handler - the time for blocked content updates is over now:
623 * Check for throttled data and send it to the userspace
624 */
625static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
626{
627 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
628
629 if (bcm_rx_thr_flush(op)) {
630 hrtimer_forward_now(hrtimer, op->kt_ival2);
631 return HRTIMER_RESTART;
632 } else {
633 /* rearm throttle handling */
634 op->kt_lastmsg = 0;
635 return HRTIMER_NORESTART;
636 }
637}
638
639/*
640 * bcm_rx_handler - handle a CAN frame reception
641 */
642static void bcm_rx_handler(struct sk_buff *skb, void *data)
643{
644 struct bcm_op *op = (struct bcm_op *)data;
645 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
646 unsigned int i;
647
648 if (op->can_id != rxframe->can_id)
649 return;
650
651 /* make sure to handle the correct frame type (CAN / CAN FD) */
652 if (op->flags & CAN_FD_FRAME) {
653 if (!can_is_canfd_skb(skb))
654 return;
655 } else {
656 if (!can_is_can_skb(skb))
657 return;
658 }
659
660 /* disable timeout */
661 hrtimer_cancel(&op->timer);
662
663 /* save rx timestamp */
664 op->rx_stamp = skb->tstamp;
665 /* save originator for recvfrom() */
666 op->rx_ifindex = skb->dev->ifindex;
667 /* update statistics */
668 op->frames_abs++;
669
670 if (op->flags & RX_RTR_FRAME) {
671 /* send reply for RTR-request (placed in op->frames[0]) */
672 bcm_can_tx(op);
673 return;
674 }
675
676 if (op->flags & RX_FILTER_ID) {
677 /* the easiest case */
678 bcm_rx_update_and_send(op, op->last_frames, rxframe);
679 goto rx_starttimer;
680 }
681
682 if (op->nframes == 1) {
683 /* simple compare with index 0 */
684 bcm_rx_cmp_to_index(op, 0, rxframe);
685 goto rx_starttimer;
686 }
687
688 if (op->nframes > 1) {
689 /*
690 * multiplex compare
691 *
692 * find the first multiplex mask that fits.
693 * Remark: The MUX-mask is stored in index 0 - but only the
694 * first 64 bits of the frame data[] are relevant (CAN FD)
695 */
696
697 for (i = 1; i < op->nframes; i++) {
698 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
699 (get_u64(op->frames, 0) &
700 get_u64(op->frames + op->cfsiz * i, 0))) {
701 bcm_rx_cmp_to_index(op, i, rxframe);
702 break;
703 }
704 }
705 }
706
707rx_starttimer:
708 bcm_rx_starttimer(op);
709}
710
711/*
712 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
713 */
714static struct bcm_op *bcm_find_op(struct list_head *ops,
715 struct bcm_msg_head *mh, int ifindex)
716{
717 struct bcm_op *op;
718
719 list_for_each_entry(op, ops, list) {
720 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
721 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
722 return op;
723 }
724
725 return NULL;
726}
727
728static void bcm_free_op_rcu(struct rcu_head *rcu_head)
729{
730 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
731
732 if ((op->frames) && (op->frames != &op->sframe))
733 kfree(op->frames);
734
735 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
736 kfree(op->last_frames);
737
738 kfree(op);
739}
740
741static void bcm_remove_op(struct bcm_op *op)
742{
743 hrtimer_cancel(&op->timer);
744 hrtimer_cancel(&op->thrtimer);
745
746 call_rcu(&op->rcu, bcm_free_op_rcu);
747}
748
749static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
750{
751 if (op->rx_reg_dev == dev) {
752 can_rx_unregister(dev_net(dev), dev, op->can_id,
753 REGMASK(op->can_id), bcm_rx_handler, op);
754
755 /* mark as removed subscription */
756 op->rx_reg_dev = NULL;
757 } else
758 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
759 "mismatch %p %p\n", op->rx_reg_dev, dev);
760}
761
762/*
763 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
764 */
765static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
766 int ifindex)
767{
768 struct bcm_op *op, *n;
769
770 list_for_each_entry_safe(op, n, ops, list) {
771 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
772 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
773
774 /* disable automatic timer on frame reception */
775 op->flags |= RX_NO_AUTOTIMER;
776
777 /*
778 * Don't care if we're bound or not (due to netdev
779 * problems) can_rx_unregister() is always a save
780 * thing to do here.
781 */
782 if (op->ifindex) {
783 /*
784 * Only remove subscriptions that had not
785 * been removed due to NETDEV_UNREGISTER
786 * in bcm_notifier()
787 */
788 if (op->rx_reg_dev) {
789 struct net_device *dev;
790
791 dev = dev_get_by_index(sock_net(op->sk),
792 op->ifindex);
793 if (dev) {
794 bcm_rx_unreg(dev, op);
795 dev_put(dev);
796 }
797 }
798 } else
799 can_rx_unregister(sock_net(op->sk), NULL,
800 op->can_id,
801 REGMASK(op->can_id),
802 bcm_rx_handler, op);
803
804 list_del(&op->list);
805 bcm_remove_op(op);
806 return 1; /* done */
807 }
808 }
809
810 return 0; /* not found */
811}
812
813/*
814 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
815 */
816static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
817 int ifindex)
818{
819 struct bcm_op *op, *n;
820
821 list_for_each_entry_safe(op, n, ops, list) {
822 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
823 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
824 list_del(&op->list);
825 bcm_remove_op(op);
826 return 1; /* done */
827 }
828 }
829
830 return 0; /* not found */
831}
832
833/*
834 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
835 */
836static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
837 int ifindex)
838{
839 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
840
841 if (!op)
842 return -EINVAL;
843
844 /* put current values into msg_head */
845 msg_head->flags = op->flags;
846 msg_head->count = op->count;
847 msg_head->ival1 = op->ival1;
848 msg_head->ival2 = op->ival2;
849 msg_head->nframes = op->nframes;
850
851 bcm_send_to_user(op, msg_head, op->frames, 0);
852
853 return MHSIZ;
854}
855
856/*
857 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
858 */
859static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
860 int ifindex, struct sock *sk)
861{
862 struct bcm_sock *bo = bcm_sk(sk);
863 struct bcm_op *op;
864 struct canfd_frame *cf;
865 unsigned int i;
866 int err;
867
868 /* we need a real device to send frames */
869 if (!ifindex)
870 return -ENODEV;
871
872 /* check nframes boundaries - we need at least one CAN frame */
873 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
874 return -EINVAL;
875
876 /* check timeval limitations */
877 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
878 return -EINVAL;
879
880 /* check the given can_id */
881 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
882 if (op) {
883 /* update existing BCM operation */
884
885 /*
886 * Do we need more space for the CAN frames than currently
887 * allocated? -> This is a _really_ unusual use-case and
888 * therefore (complexity / locking) it is not supported.
889 */
890 if (msg_head->nframes > op->nframes)
891 return -E2BIG;
892
893 /* update CAN frames content */
894 for (i = 0; i < msg_head->nframes; i++) {
895
896 cf = op->frames + op->cfsiz * i;
897 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
898
899 if (op->flags & CAN_FD_FRAME) {
900 if (cf->len > 64)
901 err = -EINVAL;
902 } else {
903 if (cf->len > 8)
904 err = -EINVAL;
905 }
906
907 if (err < 0)
908 return err;
909
910 if (msg_head->flags & TX_CP_CAN_ID) {
911 /* copy can_id into frame */
912 cf->can_id = msg_head->can_id;
913 }
914 }
915 op->flags = msg_head->flags;
916
917 } else {
918 /* insert new BCM operation for the given can_id */
919
920 op = kzalloc(OPSIZ, GFP_KERNEL);
921 if (!op)
922 return -ENOMEM;
923
924 op->can_id = msg_head->can_id;
925 op->cfsiz = CFSIZ(msg_head->flags);
926 op->flags = msg_head->flags;
927
928 /* create array for CAN frames and copy the data */
929 if (msg_head->nframes > 1) {
930 op->frames = kmalloc_array(msg_head->nframes,
931 op->cfsiz,
932 GFP_KERNEL);
933 if (!op->frames) {
934 kfree(op);
935 return -ENOMEM;
936 }
937 } else
938 op->frames = &op->sframe;
939
940 for (i = 0; i < msg_head->nframes; i++) {
941
942 cf = op->frames + op->cfsiz * i;
943 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
944
945 if (op->flags & CAN_FD_FRAME) {
946 if (cf->len > 64)
947 err = -EINVAL;
948 } else {
949 if (cf->len > 8)
950 err = -EINVAL;
951 }
952
953 if (err < 0) {
954 if (op->frames != &op->sframe)
955 kfree(op->frames);
956 kfree(op);
957 return err;
958 }
959
960 if (msg_head->flags & TX_CP_CAN_ID) {
961 /* copy can_id into frame */
962 cf->can_id = msg_head->can_id;
963 }
964 }
965
966 /* tx_ops never compare with previous received messages */
967 op->last_frames = NULL;
968
969 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
970 op->sk = sk;
971 op->ifindex = ifindex;
972
973 /* initialize uninitialized (kzalloc) structure */
974 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
975 HRTIMER_MODE_REL_SOFT);
976 op->timer.function = bcm_tx_timeout_handler;
977
978 /* currently unused in tx_ops */
979 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
980 HRTIMER_MODE_REL_SOFT);
981
982 /* add this bcm_op to the list of the tx_ops */
983 list_add(&op->list, &bo->tx_ops);
984
985 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
986
987 if (op->nframes != msg_head->nframes) {
988 op->nframes = msg_head->nframes;
989 /* start multiple frame transmission with index 0 */
990 op->currframe = 0;
991 }
992
993 /* check flags */
994
995 if (op->flags & TX_RESET_MULTI_IDX) {
996 /* start multiple frame transmission with index 0 */
997 op->currframe = 0;
998 }
999
1000 if (op->flags & SETTIMER) {
1001 /* set timer values */
1002 op->count = msg_head->count;
1003 op->ival1 = msg_head->ival1;
1004 op->ival2 = msg_head->ival2;
1005 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1006 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1007
1008 /* disable an active timer due to zero values? */
1009 if (!op->kt_ival1 && !op->kt_ival2)
1010 hrtimer_cancel(&op->timer);
1011 }
1012
1013 if (op->flags & STARTTIMER) {
1014 hrtimer_cancel(&op->timer);
1015 /* spec: send CAN frame when starting timer */
1016 op->flags |= TX_ANNOUNCE;
1017 }
1018
1019 if (op->flags & TX_ANNOUNCE) {
1020 bcm_can_tx(op);
1021 if (op->count)
1022 op->count--;
1023 }
1024
1025 if (op->flags & STARTTIMER)
1026 bcm_tx_start_timer(op);
1027
1028 return msg_head->nframes * op->cfsiz + MHSIZ;
1029}
1030
1031/*
1032 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1033 */
1034static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1035 int ifindex, struct sock *sk)
1036{
1037 struct bcm_sock *bo = bcm_sk(sk);
1038 struct bcm_op *op;
1039 int do_rx_register;
1040 int err = 0;
1041
1042 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1043 /* be robust against wrong usage ... */
1044 msg_head->flags |= RX_FILTER_ID;
1045 /* ignore trailing garbage */
1046 msg_head->nframes = 0;
1047 }
1048
1049 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1050 if (msg_head->nframes > MAX_NFRAMES + 1)
1051 return -EINVAL;
1052
1053 if ((msg_head->flags & RX_RTR_FRAME) &&
1054 ((msg_head->nframes != 1) ||
1055 (!(msg_head->can_id & CAN_RTR_FLAG))))
1056 return -EINVAL;
1057
1058 /* check timeval limitations */
1059 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1060 return -EINVAL;
1061
1062 /* check the given can_id */
1063 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1064 if (op) {
1065 /* update existing BCM operation */
1066
1067 /*
1068 * Do we need more space for the CAN frames than currently
1069 * allocated? -> This is a _really_ unusual use-case and
1070 * therefore (complexity / locking) it is not supported.
1071 */
1072 if (msg_head->nframes > op->nframes)
1073 return -E2BIG;
1074
1075 if (msg_head->nframes) {
1076 /* update CAN frames content */
1077 err = memcpy_from_msg(op->frames, msg,
1078 msg_head->nframes * op->cfsiz);
1079 if (err < 0)
1080 return err;
1081
1082 /* clear last_frames to indicate 'nothing received' */
1083 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1084 }
1085
1086 op->nframes = msg_head->nframes;
1087 op->flags = msg_head->flags;
1088
1089 /* Only an update -> do not call can_rx_register() */
1090 do_rx_register = 0;
1091
1092 } else {
1093 /* insert new BCM operation for the given can_id */
1094 op = kzalloc(OPSIZ, GFP_KERNEL);
1095 if (!op)
1096 return -ENOMEM;
1097
1098 op->can_id = msg_head->can_id;
1099 op->nframes = msg_head->nframes;
1100 op->cfsiz = CFSIZ(msg_head->flags);
1101 op->flags = msg_head->flags;
1102
1103 if (msg_head->nframes > 1) {
1104 /* create array for CAN frames and copy the data */
1105 op->frames = kmalloc_array(msg_head->nframes,
1106 op->cfsiz,
1107 GFP_KERNEL);
1108 if (!op->frames) {
1109 kfree(op);
1110 return -ENOMEM;
1111 }
1112
1113 /* create and init array for received CAN frames */
1114 op->last_frames = kcalloc(msg_head->nframes,
1115 op->cfsiz,
1116 GFP_KERNEL);
1117 if (!op->last_frames) {
1118 kfree(op->frames);
1119 kfree(op);
1120 return -ENOMEM;
1121 }
1122
1123 } else {
1124 op->frames = &op->sframe;
1125 op->last_frames = &op->last_sframe;
1126 }
1127
1128 if (msg_head->nframes) {
1129 err = memcpy_from_msg(op->frames, msg,
1130 msg_head->nframes * op->cfsiz);
1131 if (err < 0) {
1132 if (op->frames != &op->sframe)
1133 kfree(op->frames);
1134 if (op->last_frames != &op->last_sframe)
1135 kfree(op->last_frames);
1136 kfree(op);
1137 return err;
1138 }
1139 }
1140
1141 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1142 op->sk = sk;
1143 op->ifindex = ifindex;
1144
1145 /* ifindex for timeout events w/o previous frame reception */
1146 op->rx_ifindex = ifindex;
1147
1148 /* initialize uninitialized (kzalloc) structure */
1149 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1150 HRTIMER_MODE_REL_SOFT);
1151 op->timer.function = bcm_rx_timeout_handler;
1152
1153 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1154 HRTIMER_MODE_REL_SOFT);
1155 op->thrtimer.function = bcm_rx_thr_handler;
1156
1157 /* add this bcm_op to the list of the rx_ops */
1158 list_add(&op->list, &bo->rx_ops);
1159
1160 /* call can_rx_register() */
1161 do_rx_register = 1;
1162
1163 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1164
1165 /* check flags */
1166
1167 if (op->flags & RX_RTR_FRAME) {
1168 struct canfd_frame *frame0 = op->frames;
1169
1170 /* no timers in RTR-mode */
1171 hrtimer_cancel(&op->thrtimer);
1172 hrtimer_cancel(&op->timer);
1173
1174 /*
1175 * funny feature in RX(!)_SETUP only for RTR-mode:
1176 * copy can_id into frame BUT without RTR-flag to
1177 * prevent a full-load-loopback-test ... ;-]
1178 */
1179 if ((op->flags & TX_CP_CAN_ID) ||
1180 (frame0->can_id == op->can_id))
1181 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1182
1183 } else {
1184 if (op->flags & SETTIMER) {
1185
1186 /* set timer value */
1187 op->ival1 = msg_head->ival1;
1188 op->ival2 = msg_head->ival2;
1189 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1190 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1191
1192 /* disable an active timer due to zero value? */
1193 if (!op->kt_ival1)
1194 hrtimer_cancel(&op->timer);
1195
1196 /*
1197 * In any case cancel the throttle timer, flush
1198 * potentially blocked msgs and reset throttle handling
1199 */
1200 op->kt_lastmsg = 0;
1201 hrtimer_cancel(&op->thrtimer);
1202 bcm_rx_thr_flush(op);
1203 }
1204
1205 if ((op->flags & STARTTIMER) && op->kt_ival1)
1206 hrtimer_start(&op->timer, op->kt_ival1,
1207 HRTIMER_MODE_REL_SOFT);
1208 }
1209
1210 /* now we can register for can_ids, if we added a new bcm_op */
1211 if (do_rx_register) {
1212 if (ifindex) {
1213 struct net_device *dev;
1214
1215 dev = dev_get_by_index(sock_net(sk), ifindex);
1216 if (dev) {
1217 err = can_rx_register(sock_net(sk), dev,
1218 op->can_id,
1219 REGMASK(op->can_id),
1220 bcm_rx_handler, op,
1221 "bcm", sk);
1222
1223 op->rx_reg_dev = dev;
1224 dev_put(dev);
1225 }
1226
1227 } else
1228 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1229 REGMASK(op->can_id),
1230 bcm_rx_handler, op, "bcm", sk);
1231 if (err) {
1232 /* this bcm rx op is broken -> remove it */
1233 list_del(&op->list);
1234 bcm_remove_op(op);
1235 return err;
1236 }
1237 }
1238
1239 return msg_head->nframes * op->cfsiz + MHSIZ;
1240}
1241
1242/*
1243 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1244 */
1245static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1246 int cfsiz)
1247{
1248 struct sk_buff *skb;
1249 struct net_device *dev;
1250 int err;
1251
1252 /* we need a real device to send frames */
1253 if (!ifindex)
1254 return -ENODEV;
1255
1256 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1257 if (!skb)
1258 return -ENOMEM;
1259
1260 can_skb_reserve(skb);
1261
1262 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1263 if (err < 0) {
1264 kfree_skb(skb);
1265 return err;
1266 }
1267
1268 dev = dev_get_by_index(sock_net(sk), ifindex);
1269 if (!dev) {
1270 kfree_skb(skb);
1271 return -ENODEV;
1272 }
1273
1274 can_skb_prv(skb)->ifindex = dev->ifindex;
1275 can_skb_prv(skb)->skbcnt = 0;
1276 skb->dev = dev;
1277 can_skb_set_owner(skb, sk);
1278 err = can_send(skb, 1); /* send with loopback */
1279 dev_put(dev);
1280
1281 if (err)
1282 return err;
1283
1284 return cfsiz + MHSIZ;
1285}
1286
1287/*
1288 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1289 */
1290static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1291{
1292 struct sock *sk = sock->sk;
1293 struct bcm_sock *bo = bcm_sk(sk);
1294 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1295 struct bcm_msg_head msg_head;
1296 int cfsiz;
1297 int ret; /* read bytes or error codes as return value */
1298
1299 if (!bo->bound)
1300 return -ENOTCONN;
1301
1302 /* check for valid message length from userspace */
1303 if (size < MHSIZ)
1304 return -EINVAL;
1305
1306 /* read message head information */
1307 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1308 if (ret < 0)
1309 return ret;
1310
1311 cfsiz = CFSIZ(msg_head.flags);
1312 if ((size - MHSIZ) % cfsiz)
1313 return -EINVAL;
1314
1315 /* check for alternative ifindex for this bcm_op */
1316
1317 if (!ifindex && msg->msg_name) {
1318 /* no bound device as default => check msg_name */
1319 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1320
1321 if (msg->msg_namelen < BCM_MIN_NAMELEN)
1322 return -EINVAL;
1323
1324 if (addr->can_family != AF_CAN)
1325 return -EINVAL;
1326
1327 /* ifindex from sendto() */
1328 ifindex = addr->can_ifindex;
1329
1330 if (ifindex) {
1331 struct net_device *dev;
1332
1333 dev = dev_get_by_index(sock_net(sk), ifindex);
1334 if (!dev)
1335 return -ENODEV;
1336
1337 if (dev->type != ARPHRD_CAN) {
1338 dev_put(dev);
1339 return -ENODEV;
1340 }
1341
1342 dev_put(dev);
1343 }
1344 }
1345
1346 lock_sock(sk);
1347
1348 switch (msg_head.opcode) {
1349
1350 case TX_SETUP:
1351 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1352 break;
1353
1354 case RX_SETUP:
1355 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1356 break;
1357
1358 case TX_DELETE:
1359 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1360 ret = MHSIZ;
1361 else
1362 ret = -EINVAL;
1363 break;
1364
1365 case RX_DELETE:
1366 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1367 ret = MHSIZ;
1368 else
1369 ret = -EINVAL;
1370 break;
1371
1372 case TX_READ:
1373 /* reuse msg_head for the reply to TX_READ */
1374 msg_head.opcode = TX_STATUS;
1375 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1376 break;
1377
1378 case RX_READ:
1379 /* reuse msg_head for the reply to RX_READ */
1380 msg_head.opcode = RX_STATUS;
1381 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1382 break;
1383
1384 case TX_SEND:
1385 /* we need exactly one CAN frame behind the msg head */
1386 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1387 ret = -EINVAL;
1388 else
1389 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1390 break;
1391
1392 default:
1393 ret = -EINVAL;
1394 break;
1395 }
1396
1397 release_sock(sk);
1398
1399 return ret;
1400}
1401
1402/*
1403 * notification handler for netdevice status changes
1404 */
1405static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1406 struct net_device *dev)
1407{
1408 struct sock *sk = &bo->sk;
1409 struct bcm_op *op;
1410 int notify_enodev = 0;
1411
1412 if (!net_eq(dev_net(dev), sock_net(sk)))
1413 return;
1414
1415 switch (msg) {
1416
1417 case NETDEV_UNREGISTER:
1418 lock_sock(sk);
1419
1420 /* remove device specific receive entries */
1421 list_for_each_entry(op, &bo->rx_ops, list)
1422 if (op->rx_reg_dev == dev)
1423 bcm_rx_unreg(dev, op);
1424
1425 /* remove device reference, if this is our bound device */
1426 if (bo->bound && bo->ifindex == dev->ifindex) {
1427 bo->bound = 0;
1428 bo->ifindex = 0;
1429 notify_enodev = 1;
1430 }
1431
1432 release_sock(sk);
1433
1434 if (notify_enodev) {
1435 sk->sk_err = ENODEV;
1436 if (!sock_flag(sk, SOCK_DEAD))
1437 sk_error_report(sk);
1438 }
1439 break;
1440
1441 case NETDEV_DOWN:
1442 if (bo->bound && bo->ifindex == dev->ifindex) {
1443 sk->sk_err = ENETDOWN;
1444 if (!sock_flag(sk, SOCK_DEAD))
1445 sk_error_report(sk);
1446 }
1447 }
1448}
1449
1450static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1451 void *ptr)
1452{
1453 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1454
1455 if (dev->type != ARPHRD_CAN)
1456 return NOTIFY_DONE;
1457 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1458 return NOTIFY_DONE;
1459 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1460 return NOTIFY_DONE;
1461
1462 spin_lock(&bcm_notifier_lock);
1463 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1464 spin_unlock(&bcm_notifier_lock);
1465 bcm_notify(bcm_busy_notifier, msg, dev);
1466 spin_lock(&bcm_notifier_lock);
1467 }
1468 bcm_busy_notifier = NULL;
1469 spin_unlock(&bcm_notifier_lock);
1470 return NOTIFY_DONE;
1471}
1472
1473/*
1474 * initial settings for all BCM sockets to be set at socket creation time
1475 */
1476static int bcm_init(struct sock *sk)
1477{
1478 struct bcm_sock *bo = bcm_sk(sk);
1479
1480 bo->bound = 0;
1481 bo->ifindex = 0;
1482 bo->dropped_usr_msgs = 0;
1483 bo->bcm_proc_read = NULL;
1484
1485 INIT_LIST_HEAD(&bo->tx_ops);
1486 INIT_LIST_HEAD(&bo->rx_ops);
1487
1488 /* set notifier */
1489 spin_lock(&bcm_notifier_lock);
1490 list_add_tail(&bo->notifier, &bcm_notifier_list);
1491 spin_unlock(&bcm_notifier_lock);
1492
1493 return 0;
1494}
1495
1496/*
1497 * standard socket functions
1498 */
1499static int bcm_release(struct socket *sock)
1500{
1501 struct sock *sk = sock->sk;
1502 struct net *net;
1503 struct bcm_sock *bo;
1504 struct bcm_op *op, *next;
1505
1506 if (!sk)
1507 return 0;
1508
1509 net = sock_net(sk);
1510 bo = bcm_sk(sk);
1511
1512 /* remove bcm_ops, timer, rx_unregister(), etc. */
1513
1514 spin_lock(&bcm_notifier_lock);
1515 while (bcm_busy_notifier == bo) {
1516 spin_unlock(&bcm_notifier_lock);
1517 schedule_timeout_uninterruptible(1);
1518 spin_lock(&bcm_notifier_lock);
1519 }
1520 list_del(&bo->notifier);
1521 spin_unlock(&bcm_notifier_lock);
1522
1523 lock_sock(sk);
1524
1525 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1526 bcm_remove_op(op);
1527
1528 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1529 /*
1530 * Don't care if we're bound or not (due to netdev problems)
1531 * can_rx_unregister() is always a save thing to do here.
1532 */
1533 if (op->ifindex) {
1534 /*
1535 * Only remove subscriptions that had not
1536 * been removed due to NETDEV_UNREGISTER
1537 * in bcm_notifier()
1538 */
1539 if (op->rx_reg_dev) {
1540 struct net_device *dev;
1541
1542 dev = dev_get_by_index(net, op->ifindex);
1543 if (dev) {
1544 bcm_rx_unreg(dev, op);
1545 dev_put(dev);
1546 }
1547 }
1548 } else
1549 can_rx_unregister(net, NULL, op->can_id,
1550 REGMASK(op->can_id),
1551 bcm_rx_handler, op);
1552
1553 }
1554
1555 synchronize_rcu();
1556
1557 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1558 bcm_remove_op(op);
1559
1560#if IS_ENABLED(CONFIG_PROC_FS)
1561 /* remove procfs entry */
1562 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1563 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1564#endif /* CONFIG_PROC_FS */
1565
1566 /* remove device reference */
1567 if (bo->bound) {
1568 bo->bound = 0;
1569 bo->ifindex = 0;
1570 }
1571
1572 sock_orphan(sk);
1573 sock->sk = NULL;
1574
1575 release_sock(sk);
1576 sock_put(sk);
1577
1578 return 0;
1579}
1580
1581static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1582 int flags)
1583{
1584 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1585 struct sock *sk = sock->sk;
1586 struct bcm_sock *bo = bcm_sk(sk);
1587 struct net *net = sock_net(sk);
1588 int ret = 0;
1589
1590 if (len < BCM_MIN_NAMELEN)
1591 return -EINVAL;
1592
1593 lock_sock(sk);
1594
1595 if (bo->bound) {
1596 ret = -EISCONN;
1597 goto fail;
1598 }
1599
1600 /* bind a device to this socket */
1601 if (addr->can_ifindex) {
1602 struct net_device *dev;
1603
1604 dev = dev_get_by_index(net, addr->can_ifindex);
1605 if (!dev) {
1606 ret = -ENODEV;
1607 goto fail;
1608 }
1609 if (dev->type != ARPHRD_CAN) {
1610 dev_put(dev);
1611 ret = -ENODEV;
1612 goto fail;
1613 }
1614
1615 bo->ifindex = dev->ifindex;
1616 dev_put(dev);
1617
1618 } else {
1619 /* no interface reference for ifindex = 0 ('any' CAN device) */
1620 bo->ifindex = 0;
1621 }
1622
1623#if IS_ENABLED(CONFIG_PROC_FS)
1624 if (net->can.bcmproc_dir) {
1625 /* unique socket address as filename */
1626 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1627 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1628 net->can.bcmproc_dir,
1629 bcm_proc_show, sk);
1630 if (!bo->bcm_proc_read) {
1631 ret = -ENOMEM;
1632 goto fail;
1633 }
1634 }
1635#endif /* CONFIG_PROC_FS */
1636
1637 bo->bound = 1;
1638
1639fail:
1640 release_sock(sk);
1641
1642 return ret;
1643}
1644
1645static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1646 int flags)
1647{
1648 struct sock *sk = sock->sk;
1649 struct sk_buff *skb;
1650 int error = 0;
1651 int err;
1652
1653 skb = skb_recv_datagram(sk, flags, &error);
1654 if (!skb)
1655 return error;
1656
1657 if (skb->len < size)
1658 size = skb->len;
1659
1660 err = memcpy_to_msg(msg, skb->data, size);
1661 if (err < 0) {
1662 skb_free_datagram(sk, skb);
1663 return err;
1664 }
1665
1666 sock_recv_cmsgs(msg, sk, skb);
1667
1668 if (msg->msg_name) {
1669 __sockaddr_check_size(BCM_MIN_NAMELEN);
1670 msg->msg_namelen = BCM_MIN_NAMELEN;
1671 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1672 }
1673
1674 skb_free_datagram(sk, skb);
1675
1676 return size;
1677}
1678
1679static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1680 unsigned long arg)
1681{
1682 /* no ioctls for socket layer -> hand it down to NIC layer */
1683 return -ENOIOCTLCMD;
1684}
1685
1686static const struct proto_ops bcm_ops = {
1687 .family = PF_CAN,
1688 .release = bcm_release,
1689 .bind = sock_no_bind,
1690 .connect = bcm_connect,
1691 .socketpair = sock_no_socketpair,
1692 .accept = sock_no_accept,
1693 .getname = sock_no_getname,
1694 .poll = datagram_poll,
1695 .ioctl = bcm_sock_no_ioctlcmd,
1696 .gettstamp = sock_gettstamp,
1697 .listen = sock_no_listen,
1698 .shutdown = sock_no_shutdown,
1699 .sendmsg = bcm_sendmsg,
1700 .recvmsg = bcm_recvmsg,
1701 .mmap = sock_no_mmap,
1702 .sendpage = sock_no_sendpage,
1703};
1704
1705static struct proto bcm_proto __read_mostly = {
1706 .name = "CAN_BCM",
1707 .owner = THIS_MODULE,
1708 .obj_size = sizeof(struct bcm_sock),
1709 .init = bcm_init,
1710};
1711
1712static const struct can_proto bcm_can_proto = {
1713 .type = SOCK_DGRAM,
1714 .protocol = CAN_BCM,
1715 .ops = &bcm_ops,
1716 .prot = &bcm_proto,
1717};
1718
1719static int canbcm_pernet_init(struct net *net)
1720{
1721#if IS_ENABLED(CONFIG_PROC_FS)
1722 /* create /proc/net/can-bcm directory */
1723 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1724#endif /* CONFIG_PROC_FS */
1725
1726 return 0;
1727}
1728
1729static void canbcm_pernet_exit(struct net *net)
1730{
1731#if IS_ENABLED(CONFIG_PROC_FS)
1732 /* remove /proc/net/can-bcm directory */
1733 if (net->can.bcmproc_dir)
1734 remove_proc_entry("can-bcm", net->proc_net);
1735#endif /* CONFIG_PROC_FS */
1736}
1737
1738static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1739 .init = canbcm_pernet_init,
1740 .exit = canbcm_pernet_exit,
1741};
1742
1743static struct notifier_block canbcm_notifier = {
1744 .notifier_call = bcm_notifier
1745};
1746
1747static int __init bcm_module_init(void)
1748{
1749 int err;
1750
1751 pr_info("can: broadcast manager protocol\n");
1752
1753 err = register_pernet_subsys(&canbcm_pernet_ops);
1754 if (err)
1755 return err;
1756
1757 err = register_netdevice_notifier(&canbcm_notifier);
1758 if (err)
1759 goto register_notifier_failed;
1760
1761 err = can_proto_register(&bcm_can_proto);
1762 if (err < 0) {
1763 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1764 goto register_proto_failed;
1765 }
1766
1767 return 0;
1768
1769register_proto_failed:
1770 unregister_netdevice_notifier(&canbcm_notifier);
1771register_notifier_failed:
1772 unregister_pernet_subsys(&canbcm_pernet_ops);
1773 return err;
1774}
1775
1776static void __exit bcm_module_exit(void)
1777{
1778 can_proto_unregister(&bcm_can_proto);
1779 unregister_netdevice_notifier(&canbcm_notifier);
1780 unregister_pernet_subsys(&canbcm_pernet_ops);
1781}
1782
1783module_init(bcm_module_init);
1784module_exit(bcm_module_exit);