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1/*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42#include <linux/module.h>
43#include <linux/init.h>
44#include <linux/interrupt.h>
45#include <linux/hrtimer.h>
46#include <linux/list.h>
47#include <linux/proc_fs.h>
48#include <linux/seq_file.h>
49#include <linux/uio.h>
50#include <linux/net.h>
51#include <linux/netdevice.h>
52#include <linux/socket.h>
53#include <linux/if_arp.h>
54#include <linux/skbuff.h>
55#include <linux/can.h>
56#include <linux/can/core.h>
57#include <linux/can/bcm.h>
58#include <linux/slab.h>
59#include <net/sock.h>
60#include <net/net_namespace.h>
61
62/*
63 * To send multiple CAN frame content within TX_SETUP or to filter
64 * CAN messages with multiplex index within RX_SETUP, the number of
65 * different filters is limited to 256 due to the one byte index value.
66 */
67#define MAX_NFRAMES 256
68
69/* use of last_frames[index].can_dlc */
70#define RX_RECV 0x40 /* received data for this element */
71#define RX_THR 0x80 /* element not been sent due to throttle feature */
72#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
73
74/* get best masking value for can_rx_register() for a given single can_id */
75#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
76 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
77 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
78
79#define CAN_BCM_VERSION CAN_VERSION
80static __initdata const char banner[] = KERN_INFO
81 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
82
83MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
84MODULE_LICENSE("Dual BSD/GPL");
85MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
86MODULE_ALIAS("can-proto-2");
87
88/* easy access to can_frame payload */
89static inline u64 GET_U64(const struct can_frame *cp)
90{
91 return *(u64 *)cp->data;
92}
93
94struct bcm_op {
95 struct list_head list;
96 int ifindex;
97 canid_t can_id;
98 u32 flags;
99 unsigned long frames_abs, frames_filtered;
100 struct timeval ival1, ival2;
101 struct hrtimer timer, thrtimer;
102 struct tasklet_struct tsklet, thrtsklet;
103 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
104 int rx_ifindex;
105 u32 count;
106 u32 nframes;
107 u32 currframe;
108 struct can_frame *frames;
109 struct can_frame *last_frames;
110 struct can_frame sframe;
111 struct can_frame last_sframe;
112 struct sock *sk;
113 struct net_device *rx_reg_dev;
114};
115
116static struct proc_dir_entry *proc_dir;
117
118struct bcm_sock {
119 struct sock sk;
120 int bound;
121 int ifindex;
122 struct notifier_block notifier;
123 struct list_head rx_ops;
124 struct list_head tx_ops;
125 unsigned long dropped_usr_msgs;
126 struct proc_dir_entry *bcm_proc_read;
127 char procname [32]; /* inode number in decimal with \0 */
128};
129
130static inline struct bcm_sock *bcm_sk(const struct sock *sk)
131{
132 return (struct bcm_sock *)sk;
133}
134
135#define CFSIZ sizeof(struct can_frame)
136#define OPSIZ sizeof(struct bcm_op)
137#define MHSIZ sizeof(struct bcm_msg_head)
138
139/*
140 * procfs functions
141 */
142static char *bcm_proc_getifname(char *result, int ifindex)
143{
144 struct net_device *dev;
145
146 if (!ifindex)
147 return "any";
148
149 rcu_read_lock();
150 dev = dev_get_by_index_rcu(&init_net, ifindex);
151 if (dev)
152 strcpy(result, dev->name);
153 else
154 strcpy(result, "???");
155 rcu_read_unlock();
156
157 return result;
158}
159
160static int bcm_proc_show(struct seq_file *m, void *v)
161{
162 char ifname[IFNAMSIZ];
163 struct sock *sk = (struct sock *)m->private;
164 struct bcm_sock *bo = bcm_sk(sk);
165 struct bcm_op *op;
166
167 seq_printf(m, ">>> socket %pK", sk->sk_socket);
168 seq_printf(m, " / sk %pK", sk);
169 seq_printf(m, " / bo %pK", bo);
170 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
171 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
172 seq_printf(m, " <<<\n");
173
174 list_for_each_entry(op, &bo->rx_ops, list) {
175
176 unsigned long reduction;
177
178 /* print only active entries & prevent division by zero */
179 if (!op->frames_abs)
180 continue;
181
182 seq_printf(m, "rx_op: %03X %-5s ",
183 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
184 seq_printf(m, "[%u]%c ", op->nframes,
185 (op->flags & RX_CHECK_DLC)?'d':' ');
186 if (op->kt_ival1.tv64)
187 seq_printf(m, "timeo=%lld ",
188 (long long)
189 ktime_to_us(op->kt_ival1));
190
191 if (op->kt_ival2.tv64)
192 seq_printf(m, "thr=%lld ",
193 (long long)
194 ktime_to_us(op->kt_ival2));
195
196 seq_printf(m, "# recv %ld (%ld) => reduction: ",
197 op->frames_filtered, op->frames_abs);
198
199 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
200
201 seq_printf(m, "%s%ld%%\n",
202 (reduction == 100)?"near ":"", reduction);
203 }
204
205 list_for_each_entry(op, &bo->tx_ops, list) {
206
207 seq_printf(m, "tx_op: %03X %s [%u] ",
208 op->can_id,
209 bcm_proc_getifname(ifname, op->ifindex),
210 op->nframes);
211
212 if (op->kt_ival1.tv64)
213 seq_printf(m, "t1=%lld ",
214 (long long) ktime_to_us(op->kt_ival1));
215
216 if (op->kt_ival2.tv64)
217 seq_printf(m, "t2=%lld ",
218 (long long) ktime_to_us(op->kt_ival2));
219
220 seq_printf(m, "# sent %ld\n", op->frames_abs);
221 }
222 seq_putc(m, '\n');
223 return 0;
224}
225
226static int bcm_proc_open(struct inode *inode, struct file *file)
227{
228 return single_open(file, bcm_proc_show, PDE(inode)->data);
229}
230
231static const struct file_operations bcm_proc_fops = {
232 .owner = THIS_MODULE,
233 .open = bcm_proc_open,
234 .read = seq_read,
235 .llseek = seq_lseek,
236 .release = single_release,
237};
238
239/*
240 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
241 * of the given bcm tx op
242 */
243static void bcm_can_tx(struct bcm_op *op)
244{
245 struct sk_buff *skb;
246 struct net_device *dev;
247 struct can_frame *cf = &op->frames[op->currframe];
248
249 /* no target device? => exit */
250 if (!op->ifindex)
251 return;
252
253 dev = dev_get_by_index(&init_net, op->ifindex);
254 if (!dev) {
255 /* RFC: should this bcm_op remove itself here? */
256 return;
257 }
258
259 skb = alloc_skb(CFSIZ, gfp_any());
260 if (!skb)
261 goto out;
262
263 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
264
265 /* send with loopback */
266 skb->dev = dev;
267 skb->sk = op->sk;
268 can_send(skb, 1);
269
270 /* update statistics */
271 op->currframe++;
272 op->frames_abs++;
273
274 /* reached last frame? */
275 if (op->currframe >= op->nframes)
276 op->currframe = 0;
277 out:
278 dev_put(dev);
279}
280
281/*
282 * bcm_send_to_user - send a BCM message to the userspace
283 * (consisting of bcm_msg_head + x CAN frames)
284 */
285static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
286 struct can_frame *frames, int has_timestamp)
287{
288 struct sk_buff *skb;
289 struct can_frame *firstframe;
290 struct sockaddr_can *addr;
291 struct sock *sk = op->sk;
292 unsigned int datalen = head->nframes * CFSIZ;
293 int err;
294
295 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
296 if (!skb)
297 return;
298
299 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
300
301 if (head->nframes) {
302 /* can_frames starting here */
303 firstframe = (struct can_frame *)skb_tail_pointer(skb);
304
305 memcpy(skb_put(skb, datalen), frames, datalen);
306
307 /*
308 * the BCM uses the can_dlc-element of the can_frame
309 * structure for internal purposes. This is only
310 * relevant for updates that are generated by the
311 * BCM, where nframes is 1
312 */
313 if (head->nframes == 1)
314 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
315 }
316
317 if (has_timestamp) {
318 /* restore rx timestamp */
319 skb->tstamp = op->rx_stamp;
320 }
321
322 /*
323 * Put the datagram to the queue so that bcm_recvmsg() can
324 * get it from there. We need to pass the interface index to
325 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
326 * containing the interface index.
327 */
328
329 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
330 addr = (struct sockaddr_can *)skb->cb;
331 memset(addr, 0, sizeof(*addr));
332 addr->can_family = AF_CAN;
333 addr->can_ifindex = op->rx_ifindex;
334
335 err = sock_queue_rcv_skb(sk, skb);
336 if (err < 0) {
337 struct bcm_sock *bo = bcm_sk(sk);
338
339 kfree_skb(skb);
340 /* don't care about overflows in this statistic */
341 bo->dropped_usr_msgs++;
342 }
343}
344
345static void bcm_tx_start_timer(struct bcm_op *op)
346{
347 if (op->kt_ival1.tv64 && op->count)
348 hrtimer_start(&op->timer,
349 ktime_add(ktime_get(), op->kt_ival1),
350 HRTIMER_MODE_ABS);
351 else if (op->kt_ival2.tv64)
352 hrtimer_start(&op->timer,
353 ktime_add(ktime_get(), op->kt_ival2),
354 HRTIMER_MODE_ABS);
355}
356
357static void bcm_tx_timeout_tsklet(unsigned long data)
358{
359 struct bcm_op *op = (struct bcm_op *)data;
360 struct bcm_msg_head msg_head;
361
362 if (op->kt_ival1.tv64 && (op->count > 0)) {
363
364 op->count--;
365 if (!op->count && (op->flags & TX_COUNTEVT)) {
366
367 /* create notification to user */
368 msg_head.opcode = TX_EXPIRED;
369 msg_head.flags = op->flags;
370 msg_head.count = op->count;
371 msg_head.ival1 = op->ival1;
372 msg_head.ival2 = op->ival2;
373 msg_head.can_id = op->can_id;
374 msg_head.nframes = 0;
375
376 bcm_send_to_user(op, &msg_head, NULL, 0);
377 }
378 bcm_can_tx(op);
379
380 } else if (op->kt_ival2.tv64)
381 bcm_can_tx(op);
382
383 bcm_tx_start_timer(op);
384}
385
386/*
387 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
388 */
389static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
390{
391 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
392
393 tasklet_schedule(&op->tsklet);
394
395 return HRTIMER_NORESTART;
396}
397
398/*
399 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
400 */
401static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
402{
403 struct bcm_msg_head head;
404
405 /* update statistics */
406 op->frames_filtered++;
407
408 /* prevent statistics overflow */
409 if (op->frames_filtered > ULONG_MAX/100)
410 op->frames_filtered = op->frames_abs = 0;
411
412 /* this element is not throttled anymore */
413 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
414
415 head.opcode = RX_CHANGED;
416 head.flags = op->flags;
417 head.count = op->count;
418 head.ival1 = op->ival1;
419 head.ival2 = op->ival2;
420 head.can_id = op->can_id;
421 head.nframes = 1;
422
423 bcm_send_to_user(op, &head, data, 1);
424}
425
426/*
427 * bcm_rx_update_and_send - process a detected relevant receive content change
428 * 1. update the last received data
429 * 2. send a notification to the user (if possible)
430 */
431static void bcm_rx_update_and_send(struct bcm_op *op,
432 struct can_frame *lastdata,
433 const struct can_frame *rxdata)
434{
435 memcpy(lastdata, rxdata, CFSIZ);
436
437 /* mark as used and throttled by default */
438 lastdata->can_dlc |= (RX_RECV|RX_THR);
439
440 /* throtteling mode inactive ? */
441 if (!op->kt_ival2.tv64) {
442 /* send RX_CHANGED to the user immediately */
443 bcm_rx_changed(op, lastdata);
444 return;
445 }
446
447 /* with active throttling timer we are just done here */
448 if (hrtimer_active(&op->thrtimer))
449 return;
450
451 /* first receiption with enabled throttling mode */
452 if (!op->kt_lastmsg.tv64)
453 goto rx_changed_settime;
454
455 /* got a second frame inside a potential throttle period? */
456 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
457 ktime_to_us(op->kt_ival2)) {
458 /* do not send the saved data - only start throttle timer */
459 hrtimer_start(&op->thrtimer,
460 ktime_add(op->kt_lastmsg, op->kt_ival2),
461 HRTIMER_MODE_ABS);
462 return;
463 }
464
465 /* the gap was that big, that throttling was not needed here */
466rx_changed_settime:
467 bcm_rx_changed(op, lastdata);
468 op->kt_lastmsg = ktime_get();
469}
470
471/*
472 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
473 * received data stored in op->last_frames[]
474 */
475static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
476 const struct can_frame *rxdata)
477{
478 /*
479 * no one uses the MSBs of can_dlc for comparation,
480 * so we use it here to detect the first time of reception
481 */
482
483 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
484 /* received data for the first time => send update to user */
485 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
486 return;
487 }
488
489 /* do a real check in can_frame data section */
490
491 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
492 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
493 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
494 return;
495 }
496
497 if (op->flags & RX_CHECK_DLC) {
498 /* do a real check in can_frame dlc */
499 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
500 BCM_CAN_DLC_MASK)) {
501 bcm_rx_update_and_send(op, &op->last_frames[index],
502 rxdata);
503 return;
504 }
505 }
506}
507
508/*
509 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
510 */
511static void bcm_rx_starttimer(struct bcm_op *op)
512{
513 if (op->flags & RX_NO_AUTOTIMER)
514 return;
515
516 if (op->kt_ival1.tv64)
517 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
518}
519
520static void bcm_rx_timeout_tsklet(unsigned long data)
521{
522 struct bcm_op *op = (struct bcm_op *)data;
523 struct bcm_msg_head msg_head;
524
525 /* create notification to user */
526 msg_head.opcode = RX_TIMEOUT;
527 msg_head.flags = op->flags;
528 msg_head.count = op->count;
529 msg_head.ival1 = op->ival1;
530 msg_head.ival2 = op->ival2;
531 msg_head.can_id = op->can_id;
532 msg_head.nframes = 0;
533
534 bcm_send_to_user(op, &msg_head, NULL, 0);
535}
536
537/*
538 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
539 */
540static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
541{
542 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
543
544 /* schedule before NET_RX_SOFTIRQ */
545 tasklet_hi_schedule(&op->tsklet);
546
547 /* no restart of the timer is done here! */
548
549 /* if user wants to be informed, when cyclic CAN-Messages come back */
550 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
551 /* clear received can_frames to indicate 'nothing received' */
552 memset(op->last_frames, 0, op->nframes * CFSIZ);
553 }
554
555 return HRTIMER_NORESTART;
556}
557
558/*
559 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
560 */
561static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
562 unsigned int index)
563{
564 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
565 if (update)
566 bcm_rx_changed(op, &op->last_frames[index]);
567 return 1;
568 }
569 return 0;
570}
571
572/*
573 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
574 *
575 * update == 0 : just check if throttled data is available (any irq context)
576 * update == 1 : check and send throttled data to userspace (soft_irq context)
577 */
578static int bcm_rx_thr_flush(struct bcm_op *op, int update)
579{
580 int updated = 0;
581
582 if (op->nframes > 1) {
583 unsigned int i;
584
585 /* for MUX filter we start at index 1 */
586 for (i = 1; i < op->nframes; i++)
587 updated += bcm_rx_do_flush(op, update, i);
588
589 } else {
590 /* for RX_FILTER_ID and simple filter */
591 updated += bcm_rx_do_flush(op, update, 0);
592 }
593
594 return updated;
595}
596
597static void bcm_rx_thr_tsklet(unsigned long data)
598{
599 struct bcm_op *op = (struct bcm_op *)data;
600
601 /* push the changed data to the userspace */
602 bcm_rx_thr_flush(op, 1);
603}
604
605/*
606 * bcm_rx_thr_handler - the time for blocked content updates is over now:
607 * Check for throttled data and send it to the userspace
608 */
609static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
610{
611 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
612
613 tasklet_schedule(&op->thrtsklet);
614
615 if (bcm_rx_thr_flush(op, 0)) {
616 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
617 return HRTIMER_RESTART;
618 } else {
619 /* rearm throttle handling */
620 op->kt_lastmsg = ktime_set(0, 0);
621 return HRTIMER_NORESTART;
622 }
623}
624
625/*
626 * bcm_rx_handler - handle a CAN frame receiption
627 */
628static void bcm_rx_handler(struct sk_buff *skb, void *data)
629{
630 struct bcm_op *op = (struct bcm_op *)data;
631 const struct can_frame *rxframe = (struct can_frame *)skb->data;
632 unsigned int i;
633
634 /* disable timeout */
635 hrtimer_cancel(&op->timer);
636
637 if (op->can_id != rxframe->can_id)
638 return;
639
640 /* save rx timestamp */
641 op->rx_stamp = skb->tstamp;
642 /* save originator for recvfrom() */
643 op->rx_ifindex = skb->dev->ifindex;
644 /* update statistics */
645 op->frames_abs++;
646
647 if (op->flags & RX_RTR_FRAME) {
648 /* send reply for RTR-request (placed in op->frames[0]) */
649 bcm_can_tx(op);
650 return;
651 }
652
653 if (op->flags & RX_FILTER_ID) {
654 /* the easiest case */
655 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
656 goto rx_starttimer;
657 }
658
659 if (op->nframes == 1) {
660 /* simple compare with index 0 */
661 bcm_rx_cmp_to_index(op, 0, rxframe);
662 goto rx_starttimer;
663 }
664
665 if (op->nframes > 1) {
666 /*
667 * multiplex compare
668 *
669 * find the first multiplex mask that fits.
670 * Remark: The MUX-mask is stored in index 0
671 */
672
673 for (i = 1; i < op->nframes; i++) {
674 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
675 (GET_U64(&op->frames[0]) &
676 GET_U64(&op->frames[i]))) {
677 bcm_rx_cmp_to_index(op, i, rxframe);
678 break;
679 }
680 }
681 }
682
683rx_starttimer:
684 bcm_rx_starttimer(op);
685}
686
687/*
688 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
689 */
690static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
691 int ifindex)
692{
693 struct bcm_op *op;
694
695 list_for_each_entry(op, ops, list) {
696 if ((op->can_id == can_id) && (op->ifindex == ifindex))
697 return op;
698 }
699
700 return NULL;
701}
702
703static void bcm_remove_op(struct bcm_op *op)
704{
705 hrtimer_cancel(&op->timer);
706 hrtimer_cancel(&op->thrtimer);
707
708 if (op->tsklet.func)
709 tasklet_kill(&op->tsklet);
710
711 if (op->thrtsklet.func)
712 tasklet_kill(&op->thrtsklet);
713
714 if ((op->frames) && (op->frames != &op->sframe))
715 kfree(op->frames);
716
717 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
718 kfree(op->last_frames);
719
720 kfree(op);
721}
722
723static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
724{
725 if (op->rx_reg_dev == dev) {
726 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
727 bcm_rx_handler, op);
728
729 /* mark as removed subscription */
730 op->rx_reg_dev = NULL;
731 } else
732 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
733 "mismatch %p %p\n", op->rx_reg_dev, dev);
734}
735
736/*
737 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
738 */
739static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
740{
741 struct bcm_op *op, *n;
742
743 list_for_each_entry_safe(op, n, ops, list) {
744 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
745
746 /*
747 * Don't care if we're bound or not (due to netdev
748 * problems) can_rx_unregister() is always a save
749 * thing to do here.
750 */
751 if (op->ifindex) {
752 /*
753 * Only remove subscriptions that had not
754 * been removed due to NETDEV_UNREGISTER
755 * in bcm_notifier()
756 */
757 if (op->rx_reg_dev) {
758 struct net_device *dev;
759
760 dev = dev_get_by_index(&init_net,
761 op->ifindex);
762 if (dev) {
763 bcm_rx_unreg(dev, op);
764 dev_put(dev);
765 }
766 }
767 } else
768 can_rx_unregister(NULL, op->can_id,
769 REGMASK(op->can_id),
770 bcm_rx_handler, op);
771
772 list_del(&op->list);
773 bcm_remove_op(op);
774 return 1; /* done */
775 }
776 }
777
778 return 0; /* not found */
779}
780
781/*
782 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
783 */
784static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
785{
786 struct bcm_op *op, *n;
787
788 list_for_each_entry_safe(op, n, ops, list) {
789 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
790 list_del(&op->list);
791 bcm_remove_op(op);
792 return 1; /* done */
793 }
794 }
795
796 return 0; /* not found */
797}
798
799/*
800 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
801 */
802static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
803 int ifindex)
804{
805 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
806
807 if (!op)
808 return -EINVAL;
809
810 /* put current values into msg_head */
811 msg_head->flags = op->flags;
812 msg_head->count = op->count;
813 msg_head->ival1 = op->ival1;
814 msg_head->ival2 = op->ival2;
815 msg_head->nframes = op->nframes;
816
817 bcm_send_to_user(op, msg_head, op->frames, 0);
818
819 return MHSIZ;
820}
821
822/*
823 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
824 */
825static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
826 int ifindex, struct sock *sk)
827{
828 struct bcm_sock *bo = bcm_sk(sk);
829 struct bcm_op *op;
830 unsigned int i;
831 int err;
832
833 /* we need a real device to send frames */
834 if (!ifindex)
835 return -ENODEV;
836
837 /* check nframes boundaries - we need at least one can_frame */
838 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
839 return -EINVAL;
840
841 /* check the given can_id */
842 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
843
844 if (op) {
845 /* update existing BCM operation */
846
847 /*
848 * Do we need more space for the can_frames than currently
849 * allocated? -> This is a _really_ unusual use-case and
850 * therefore (complexity / locking) it is not supported.
851 */
852 if (msg_head->nframes > op->nframes)
853 return -E2BIG;
854
855 /* update can_frames content */
856 for (i = 0; i < msg_head->nframes; i++) {
857 err = memcpy_fromiovec((u8 *)&op->frames[i],
858 msg->msg_iov, CFSIZ);
859
860 if (op->frames[i].can_dlc > 8)
861 err = -EINVAL;
862
863 if (err < 0)
864 return err;
865
866 if (msg_head->flags & TX_CP_CAN_ID) {
867 /* copy can_id into frame */
868 op->frames[i].can_id = msg_head->can_id;
869 }
870 }
871
872 } else {
873 /* insert new BCM operation for the given can_id */
874
875 op = kzalloc(OPSIZ, GFP_KERNEL);
876 if (!op)
877 return -ENOMEM;
878
879 op->can_id = msg_head->can_id;
880
881 /* create array for can_frames and copy the data */
882 if (msg_head->nframes > 1) {
883 op->frames = kmalloc(msg_head->nframes * CFSIZ,
884 GFP_KERNEL);
885 if (!op->frames) {
886 kfree(op);
887 return -ENOMEM;
888 }
889 } else
890 op->frames = &op->sframe;
891
892 for (i = 0; i < msg_head->nframes; i++) {
893 err = memcpy_fromiovec((u8 *)&op->frames[i],
894 msg->msg_iov, CFSIZ);
895
896 if (op->frames[i].can_dlc > 8)
897 err = -EINVAL;
898
899 if (err < 0) {
900 if (op->frames != &op->sframe)
901 kfree(op->frames);
902 kfree(op);
903 return err;
904 }
905
906 if (msg_head->flags & TX_CP_CAN_ID) {
907 /* copy can_id into frame */
908 op->frames[i].can_id = msg_head->can_id;
909 }
910 }
911
912 /* tx_ops never compare with previous received messages */
913 op->last_frames = NULL;
914
915 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
916 op->sk = sk;
917 op->ifindex = ifindex;
918
919 /* initialize uninitialized (kzalloc) structure */
920 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
921 op->timer.function = bcm_tx_timeout_handler;
922
923 /* initialize tasklet for tx countevent notification */
924 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
925 (unsigned long) op);
926
927 /* currently unused in tx_ops */
928 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
929
930 /* add this bcm_op to the list of the tx_ops */
931 list_add(&op->list, &bo->tx_ops);
932
933 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
934
935 if (op->nframes != msg_head->nframes) {
936 op->nframes = msg_head->nframes;
937 /* start multiple frame transmission with index 0 */
938 op->currframe = 0;
939 }
940
941 /* check flags */
942
943 op->flags = msg_head->flags;
944
945 if (op->flags & TX_RESET_MULTI_IDX) {
946 /* start multiple frame transmission with index 0 */
947 op->currframe = 0;
948 }
949
950 if (op->flags & SETTIMER) {
951 /* set timer values */
952 op->count = msg_head->count;
953 op->ival1 = msg_head->ival1;
954 op->ival2 = msg_head->ival2;
955 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
956 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
957
958 /* disable an active timer due to zero values? */
959 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
960 hrtimer_cancel(&op->timer);
961 }
962
963 if (op->flags & STARTTIMER) {
964 hrtimer_cancel(&op->timer);
965 /* spec: send can_frame when starting timer */
966 op->flags |= TX_ANNOUNCE;
967 }
968
969 if (op->flags & TX_ANNOUNCE) {
970 bcm_can_tx(op);
971 if (op->count)
972 op->count--;
973 }
974
975 if (op->flags & STARTTIMER)
976 bcm_tx_start_timer(op);
977
978 return msg_head->nframes * CFSIZ + MHSIZ;
979}
980
981/*
982 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
983 */
984static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
985 int ifindex, struct sock *sk)
986{
987 struct bcm_sock *bo = bcm_sk(sk);
988 struct bcm_op *op;
989 int do_rx_register;
990 int err = 0;
991
992 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
993 /* be robust against wrong usage ... */
994 msg_head->flags |= RX_FILTER_ID;
995 /* ignore trailing garbage */
996 msg_head->nframes = 0;
997 }
998
999 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1000 if (msg_head->nframes > MAX_NFRAMES + 1)
1001 return -EINVAL;
1002
1003 if ((msg_head->flags & RX_RTR_FRAME) &&
1004 ((msg_head->nframes != 1) ||
1005 (!(msg_head->can_id & CAN_RTR_FLAG))))
1006 return -EINVAL;
1007
1008 /* check the given can_id */
1009 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1010 if (op) {
1011 /* update existing BCM operation */
1012
1013 /*
1014 * Do we need more space for the can_frames than currently
1015 * allocated? -> This is a _really_ unusual use-case and
1016 * therefore (complexity / locking) it is not supported.
1017 */
1018 if (msg_head->nframes > op->nframes)
1019 return -E2BIG;
1020
1021 if (msg_head->nframes) {
1022 /* update can_frames content */
1023 err = memcpy_fromiovec((u8 *)op->frames,
1024 msg->msg_iov,
1025 msg_head->nframes * CFSIZ);
1026 if (err < 0)
1027 return err;
1028
1029 /* clear last_frames to indicate 'nothing received' */
1030 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1031 }
1032
1033 op->nframes = msg_head->nframes;
1034
1035 /* Only an update -> do not call can_rx_register() */
1036 do_rx_register = 0;
1037
1038 } else {
1039 /* insert new BCM operation for the given can_id */
1040 op = kzalloc(OPSIZ, GFP_KERNEL);
1041 if (!op)
1042 return -ENOMEM;
1043
1044 op->can_id = msg_head->can_id;
1045 op->nframes = msg_head->nframes;
1046
1047 if (msg_head->nframes > 1) {
1048 /* create array for can_frames and copy the data */
1049 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1050 GFP_KERNEL);
1051 if (!op->frames) {
1052 kfree(op);
1053 return -ENOMEM;
1054 }
1055
1056 /* create and init array for received can_frames */
1057 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1058 GFP_KERNEL);
1059 if (!op->last_frames) {
1060 kfree(op->frames);
1061 kfree(op);
1062 return -ENOMEM;
1063 }
1064
1065 } else {
1066 op->frames = &op->sframe;
1067 op->last_frames = &op->last_sframe;
1068 }
1069
1070 if (msg_head->nframes) {
1071 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1072 msg_head->nframes * CFSIZ);
1073 if (err < 0) {
1074 if (op->frames != &op->sframe)
1075 kfree(op->frames);
1076 if (op->last_frames != &op->last_sframe)
1077 kfree(op->last_frames);
1078 kfree(op);
1079 return err;
1080 }
1081 }
1082
1083 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1084 op->sk = sk;
1085 op->ifindex = ifindex;
1086
1087 /* initialize uninitialized (kzalloc) structure */
1088 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1089 op->timer.function = bcm_rx_timeout_handler;
1090
1091 /* initialize tasklet for rx timeout notification */
1092 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1093 (unsigned long) op);
1094
1095 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1096 op->thrtimer.function = bcm_rx_thr_handler;
1097
1098 /* initialize tasklet for rx throttle handling */
1099 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1100 (unsigned long) op);
1101
1102 /* add this bcm_op to the list of the rx_ops */
1103 list_add(&op->list, &bo->rx_ops);
1104
1105 /* call can_rx_register() */
1106 do_rx_register = 1;
1107
1108 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1109
1110 /* check flags */
1111 op->flags = msg_head->flags;
1112
1113 if (op->flags & RX_RTR_FRAME) {
1114
1115 /* no timers in RTR-mode */
1116 hrtimer_cancel(&op->thrtimer);
1117 hrtimer_cancel(&op->timer);
1118
1119 /*
1120 * funny feature in RX(!)_SETUP only for RTR-mode:
1121 * copy can_id into frame BUT without RTR-flag to
1122 * prevent a full-load-loopback-test ... ;-]
1123 */
1124 if ((op->flags & TX_CP_CAN_ID) ||
1125 (op->frames[0].can_id == op->can_id))
1126 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1127
1128 } else {
1129 if (op->flags & SETTIMER) {
1130
1131 /* set timer value */
1132 op->ival1 = msg_head->ival1;
1133 op->ival2 = msg_head->ival2;
1134 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1135 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1136
1137 /* disable an active timer due to zero value? */
1138 if (!op->kt_ival1.tv64)
1139 hrtimer_cancel(&op->timer);
1140
1141 /*
1142 * In any case cancel the throttle timer, flush
1143 * potentially blocked msgs and reset throttle handling
1144 */
1145 op->kt_lastmsg = ktime_set(0, 0);
1146 hrtimer_cancel(&op->thrtimer);
1147 bcm_rx_thr_flush(op, 1);
1148 }
1149
1150 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1151 hrtimer_start(&op->timer, op->kt_ival1,
1152 HRTIMER_MODE_REL);
1153 }
1154
1155 /* now we can register for can_ids, if we added a new bcm_op */
1156 if (do_rx_register) {
1157 if (ifindex) {
1158 struct net_device *dev;
1159
1160 dev = dev_get_by_index(&init_net, ifindex);
1161 if (dev) {
1162 err = can_rx_register(dev, op->can_id,
1163 REGMASK(op->can_id),
1164 bcm_rx_handler, op,
1165 "bcm");
1166
1167 op->rx_reg_dev = dev;
1168 dev_put(dev);
1169 }
1170
1171 } else
1172 err = can_rx_register(NULL, op->can_id,
1173 REGMASK(op->can_id),
1174 bcm_rx_handler, op, "bcm");
1175 if (err) {
1176 /* this bcm rx op is broken -> remove it */
1177 list_del(&op->list);
1178 bcm_remove_op(op);
1179 return err;
1180 }
1181 }
1182
1183 return msg_head->nframes * CFSIZ + MHSIZ;
1184}
1185
1186/*
1187 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1188 */
1189static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1190{
1191 struct sk_buff *skb;
1192 struct net_device *dev;
1193 int err;
1194
1195 /* we need a real device to send frames */
1196 if (!ifindex)
1197 return -ENODEV;
1198
1199 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1200
1201 if (!skb)
1202 return -ENOMEM;
1203
1204 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1205 if (err < 0) {
1206 kfree_skb(skb);
1207 return err;
1208 }
1209
1210 dev = dev_get_by_index(&init_net, ifindex);
1211 if (!dev) {
1212 kfree_skb(skb);
1213 return -ENODEV;
1214 }
1215
1216 skb->dev = dev;
1217 skb->sk = sk;
1218 err = can_send(skb, 1); /* send with loopback */
1219 dev_put(dev);
1220
1221 if (err)
1222 return err;
1223
1224 return CFSIZ + MHSIZ;
1225}
1226
1227/*
1228 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1229 */
1230static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1231 struct msghdr *msg, size_t size)
1232{
1233 struct sock *sk = sock->sk;
1234 struct bcm_sock *bo = bcm_sk(sk);
1235 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1236 struct bcm_msg_head msg_head;
1237 int ret; /* read bytes or error codes as return value */
1238
1239 if (!bo->bound)
1240 return -ENOTCONN;
1241
1242 /* check for valid message length from userspace */
1243 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1244 return -EINVAL;
1245
1246 /* check for alternative ifindex for this bcm_op */
1247
1248 if (!ifindex && msg->msg_name) {
1249 /* no bound device as default => check msg_name */
1250 struct sockaddr_can *addr =
1251 (struct sockaddr_can *)msg->msg_name;
1252
1253 if (msg->msg_namelen < sizeof(*addr))
1254 return -EINVAL;
1255
1256 if (addr->can_family != AF_CAN)
1257 return -EINVAL;
1258
1259 /* ifindex from sendto() */
1260 ifindex = addr->can_ifindex;
1261
1262 if (ifindex) {
1263 struct net_device *dev;
1264
1265 dev = dev_get_by_index(&init_net, ifindex);
1266 if (!dev)
1267 return -ENODEV;
1268
1269 if (dev->type != ARPHRD_CAN) {
1270 dev_put(dev);
1271 return -ENODEV;
1272 }
1273
1274 dev_put(dev);
1275 }
1276 }
1277
1278 /* read message head information */
1279
1280 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1281 if (ret < 0)
1282 return ret;
1283
1284 lock_sock(sk);
1285
1286 switch (msg_head.opcode) {
1287
1288 case TX_SETUP:
1289 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1290 break;
1291
1292 case RX_SETUP:
1293 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1294 break;
1295
1296 case TX_DELETE:
1297 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1298 ret = MHSIZ;
1299 else
1300 ret = -EINVAL;
1301 break;
1302
1303 case RX_DELETE:
1304 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1305 ret = MHSIZ;
1306 else
1307 ret = -EINVAL;
1308 break;
1309
1310 case TX_READ:
1311 /* reuse msg_head for the reply to TX_READ */
1312 msg_head.opcode = TX_STATUS;
1313 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1314 break;
1315
1316 case RX_READ:
1317 /* reuse msg_head for the reply to RX_READ */
1318 msg_head.opcode = RX_STATUS;
1319 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1320 break;
1321
1322 case TX_SEND:
1323 /* we need exactly one can_frame behind the msg head */
1324 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1325 ret = -EINVAL;
1326 else
1327 ret = bcm_tx_send(msg, ifindex, sk);
1328 break;
1329
1330 default:
1331 ret = -EINVAL;
1332 break;
1333 }
1334
1335 release_sock(sk);
1336
1337 return ret;
1338}
1339
1340/*
1341 * notification handler for netdevice status changes
1342 */
1343static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1344 void *data)
1345{
1346 struct net_device *dev = (struct net_device *)data;
1347 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1348 struct sock *sk = &bo->sk;
1349 struct bcm_op *op;
1350 int notify_enodev = 0;
1351
1352 if (!net_eq(dev_net(dev), &init_net))
1353 return NOTIFY_DONE;
1354
1355 if (dev->type != ARPHRD_CAN)
1356 return NOTIFY_DONE;
1357
1358 switch (msg) {
1359
1360 case NETDEV_UNREGISTER:
1361 lock_sock(sk);
1362
1363 /* remove device specific receive entries */
1364 list_for_each_entry(op, &bo->rx_ops, list)
1365 if (op->rx_reg_dev == dev)
1366 bcm_rx_unreg(dev, op);
1367
1368 /* remove device reference, if this is our bound device */
1369 if (bo->bound && bo->ifindex == dev->ifindex) {
1370 bo->bound = 0;
1371 bo->ifindex = 0;
1372 notify_enodev = 1;
1373 }
1374
1375 release_sock(sk);
1376
1377 if (notify_enodev) {
1378 sk->sk_err = ENODEV;
1379 if (!sock_flag(sk, SOCK_DEAD))
1380 sk->sk_error_report(sk);
1381 }
1382 break;
1383
1384 case NETDEV_DOWN:
1385 if (bo->bound && bo->ifindex == dev->ifindex) {
1386 sk->sk_err = ENETDOWN;
1387 if (!sock_flag(sk, SOCK_DEAD))
1388 sk->sk_error_report(sk);
1389 }
1390 }
1391
1392 return NOTIFY_DONE;
1393}
1394
1395/*
1396 * initial settings for all BCM sockets to be set at socket creation time
1397 */
1398static int bcm_init(struct sock *sk)
1399{
1400 struct bcm_sock *bo = bcm_sk(sk);
1401
1402 bo->bound = 0;
1403 bo->ifindex = 0;
1404 bo->dropped_usr_msgs = 0;
1405 bo->bcm_proc_read = NULL;
1406
1407 INIT_LIST_HEAD(&bo->tx_ops);
1408 INIT_LIST_HEAD(&bo->rx_ops);
1409
1410 /* set notifier */
1411 bo->notifier.notifier_call = bcm_notifier;
1412
1413 register_netdevice_notifier(&bo->notifier);
1414
1415 return 0;
1416}
1417
1418/*
1419 * standard socket functions
1420 */
1421static int bcm_release(struct socket *sock)
1422{
1423 struct sock *sk = sock->sk;
1424 struct bcm_sock *bo;
1425 struct bcm_op *op, *next;
1426
1427 if (sk == NULL)
1428 return 0;
1429
1430 bo = bcm_sk(sk);
1431
1432 /* remove bcm_ops, timer, rx_unregister(), etc. */
1433
1434 unregister_netdevice_notifier(&bo->notifier);
1435
1436 lock_sock(sk);
1437
1438 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1439 bcm_remove_op(op);
1440
1441 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1442 /*
1443 * Don't care if we're bound or not (due to netdev problems)
1444 * can_rx_unregister() is always a save thing to do here.
1445 */
1446 if (op->ifindex) {
1447 /*
1448 * Only remove subscriptions that had not
1449 * been removed due to NETDEV_UNREGISTER
1450 * in bcm_notifier()
1451 */
1452 if (op->rx_reg_dev) {
1453 struct net_device *dev;
1454
1455 dev = dev_get_by_index(&init_net, op->ifindex);
1456 if (dev) {
1457 bcm_rx_unreg(dev, op);
1458 dev_put(dev);
1459 }
1460 }
1461 } else
1462 can_rx_unregister(NULL, op->can_id,
1463 REGMASK(op->can_id),
1464 bcm_rx_handler, op);
1465
1466 bcm_remove_op(op);
1467 }
1468
1469 /* remove procfs entry */
1470 if (proc_dir && bo->bcm_proc_read)
1471 remove_proc_entry(bo->procname, proc_dir);
1472
1473 /* remove device reference */
1474 if (bo->bound) {
1475 bo->bound = 0;
1476 bo->ifindex = 0;
1477 }
1478
1479 sock_orphan(sk);
1480 sock->sk = NULL;
1481
1482 release_sock(sk);
1483 sock_put(sk);
1484
1485 return 0;
1486}
1487
1488static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1489 int flags)
1490{
1491 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1492 struct sock *sk = sock->sk;
1493 struct bcm_sock *bo = bcm_sk(sk);
1494
1495 if (len < sizeof(*addr))
1496 return -EINVAL;
1497
1498 if (bo->bound)
1499 return -EISCONN;
1500
1501 /* bind a device to this socket */
1502 if (addr->can_ifindex) {
1503 struct net_device *dev;
1504
1505 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1506 if (!dev)
1507 return -ENODEV;
1508
1509 if (dev->type != ARPHRD_CAN) {
1510 dev_put(dev);
1511 return -ENODEV;
1512 }
1513
1514 bo->ifindex = dev->ifindex;
1515 dev_put(dev);
1516
1517 } else {
1518 /* no interface reference for ifindex = 0 ('any' CAN device) */
1519 bo->ifindex = 0;
1520 }
1521
1522 bo->bound = 1;
1523
1524 if (proc_dir) {
1525 /* unique socket address as filename */
1526 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1527 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1528 proc_dir,
1529 &bcm_proc_fops, sk);
1530 }
1531
1532 return 0;
1533}
1534
1535static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1536 struct msghdr *msg, size_t size, int flags)
1537{
1538 struct sock *sk = sock->sk;
1539 struct sk_buff *skb;
1540 int error = 0;
1541 int noblock;
1542 int err;
1543
1544 noblock = flags & MSG_DONTWAIT;
1545 flags &= ~MSG_DONTWAIT;
1546 skb = skb_recv_datagram(sk, flags, noblock, &error);
1547 if (!skb)
1548 return error;
1549
1550 if (skb->len < size)
1551 size = skb->len;
1552
1553 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1554 if (err < 0) {
1555 skb_free_datagram(sk, skb);
1556 return err;
1557 }
1558
1559 sock_recv_ts_and_drops(msg, sk, skb);
1560
1561 if (msg->msg_name) {
1562 msg->msg_namelen = sizeof(struct sockaddr_can);
1563 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1564 }
1565
1566 skb_free_datagram(sk, skb);
1567
1568 return size;
1569}
1570
1571static const struct proto_ops bcm_ops = {
1572 .family = PF_CAN,
1573 .release = bcm_release,
1574 .bind = sock_no_bind,
1575 .connect = bcm_connect,
1576 .socketpair = sock_no_socketpair,
1577 .accept = sock_no_accept,
1578 .getname = sock_no_getname,
1579 .poll = datagram_poll,
1580 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1581 .listen = sock_no_listen,
1582 .shutdown = sock_no_shutdown,
1583 .setsockopt = sock_no_setsockopt,
1584 .getsockopt = sock_no_getsockopt,
1585 .sendmsg = bcm_sendmsg,
1586 .recvmsg = bcm_recvmsg,
1587 .mmap = sock_no_mmap,
1588 .sendpage = sock_no_sendpage,
1589};
1590
1591static struct proto bcm_proto __read_mostly = {
1592 .name = "CAN_BCM",
1593 .owner = THIS_MODULE,
1594 .obj_size = sizeof(struct bcm_sock),
1595 .init = bcm_init,
1596};
1597
1598static const struct can_proto bcm_can_proto = {
1599 .type = SOCK_DGRAM,
1600 .protocol = CAN_BCM,
1601 .ops = &bcm_ops,
1602 .prot = &bcm_proto,
1603};
1604
1605static int __init bcm_module_init(void)
1606{
1607 int err;
1608
1609 printk(banner);
1610
1611 err = can_proto_register(&bcm_can_proto);
1612 if (err < 0) {
1613 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1614 return err;
1615 }
1616
1617 /* create /proc/net/can-bcm directory */
1618 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1619 return 0;
1620}
1621
1622static void __exit bcm_module_exit(void)
1623{
1624 can_proto_unregister(&bcm_can_proto);
1625
1626 if (proc_dir)
1627 proc_net_remove(&init_net, "can-bcm");
1628}
1629
1630module_init(bcm_module_init);
1631module_exit(bcm_module_exit);
1/*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42#include <linux/module.h>
43#include <linux/init.h>
44#include <linux/interrupt.h>
45#include <linux/hrtimer.h>
46#include <linux/list.h>
47#include <linux/proc_fs.h>
48#include <linux/seq_file.h>
49#include <linux/uio.h>
50#include <linux/net.h>
51#include <linux/netdevice.h>
52#include <linux/socket.h>
53#include <linux/if_arp.h>
54#include <linux/skbuff.h>
55#include <linux/can.h>
56#include <linux/can/core.h>
57#include <linux/can/skb.h>
58#include <linux/can/bcm.h>
59#include <linux/slab.h>
60#include <net/sock.h>
61#include <net/net_namespace.h>
62
63/*
64 * To send multiple CAN frame content within TX_SETUP or to filter
65 * CAN messages with multiplex index within RX_SETUP, the number of
66 * different filters is limited to 256 due to the one byte index value.
67 */
68#define MAX_NFRAMES 256
69
70/* use of last_frames[index].flags */
71#define RX_RECV 0x40 /* received data for this element */
72#define RX_THR 0x80 /* element not been sent due to throttle feature */
73#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
74
75/* get best masking value for can_rx_register() for a given single can_id */
76#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
77 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
78 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
79
80#define CAN_BCM_VERSION "20170425"
81
82MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
83MODULE_LICENSE("Dual BSD/GPL");
84MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
85MODULE_ALIAS("can-proto-2");
86
87/*
88 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
89 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
90 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
91 */
92static inline u64 get_u64(const struct canfd_frame *cp, int offset)
93{
94 return *(u64 *)(cp->data + offset);
95}
96
97struct bcm_op {
98 struct list_head list;
99 int ifindex;
100 canid_t can_id;
101 u32 flags;
102 unsigned long frames_abs, frames_filtered;
103 struct bcm_timeval ival1, ival2;
104 struct hrtimer timer, thrtimer;
105 struct tasklet_struct tsklet, thrtsklet;
106 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
107 int rx_ifindex;
108 int cfsiz;
109 u32 count;
110 u32 nframes;
111 u32 currframe;
112 /* void pointers to arrays of struct can[fd]_frame */
113 void *frames;
114 void *last_frames;
115 struct canfd_frame sframe;
116 struct canfd_frame last_sframe;
117 struct sock *sk;
118 struct net_device *rx_reg_dev;
119};
120
121struct bcm_sock {
122 struct sock sk;
123 int bound;
124 int ifindex;
125 struct notifier_block notifier;
126 struct list_head rx_ops;
127 struct list_head tx_ops;
128 unsigned long dropped_usr_msgs;
129 struct proc_dir_entry *bcm_proc_read;
130 char procname [32]; /* inode number in decimal with \0 */
131};
132
133static inline struct bcm_sock *bcm_sk(const struct sock *sk)
134{
135 return (struct bcm_sock *)sk;
136}
137
138static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
139{
140 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
141}
142
143#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
144#define OPSIZ sizeof(struct bcm_op)
145#define MHSIZ sizeof(struct bcm_msg_head)
146
147/*
148 * procfs functions
149 */
150#if IS_ENABLED(CONFIG_PROC_FS)
151static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
152{
153 struct net_device *dev;
154
155 if (!ifindex)
156 return "any";
157
158 rcu_read_lock();
159 dev = dev_get_by_index_rcu(net, ifindex);
160 if (dev)
161 strcpy(result, dev->name);
162 else
163 strcpy(result, "???");
164 rcu_read_unlock();
165
166 return result;
167}
168
169static int bcm_proc_show(struct seq_file *m, void *v)
170{
171 char ifname[IFNAMSIZ];
172 struct net *net = m->private;
173 struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
174 struct bcm_sock *bo = bcm_sk(sk);
175 struct bcm_op *op;
176
177 seq_printf(m, ">>> socket %pK", sk->sk_socket);
178 seq_printf(m, " / sk %pK", sk);
179 seq_printf(m, " / bo %pK", bo);
180 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
181 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
182 seq_printf(m, " <<<\n");
183
184 list_for_each_entry(op, &bo->rx_ops, list) {
185
186 unsigned long reduction;
187
188 /* print only active entries & prevent division by zero */
189 if (!op->frames_abs)
190 continue;
191
192 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
193 bcm_proc_getifname(net, ifname, op->ifindex));
194
195 if (op->flags & CAN_FD_FRAME)
196 seq_printf(m, "(%u)", op->nframes);
197 else
198 seq_printf(m, "[%u]", op->nframes);
199
200 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
201
202 if (op->kt_ival1)
203 seq_printf(m, "timeo=%lld ",
204 (long long)ktime_to_us(op->kt_ival1));
205
206 if (op->kt_ival2)
207 seq_printf(m, "thr=%lld ",
208 (long long)ktime_to_us(op->kt_ival2));
209
210 seq_printf(m, "# recv %ld (%ld) => reduction: ",
211 op->frames_filtered, op->frames_abs);
212
213 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
214
215 seq_printf(m, "%s%ld%%\n",
216 (reduction == 100) ? "near " : "", reduction);
217 }
218
219 list_for_each_entry(op, &bo->tx_ops, list) {
220
221 seq_printf(m, "tx_op: %03X %s ", op->can_id,
222 bcm_proc_getifname(net, ifname, op->ifindex));
223
224 if (op->flags & CAN_FD_FRAME)
225 seq_printf(m, "(%u) ", op->nframes);
226 else
227 seq_printf(m, "[%u] ", op->nframes);
228
229 if (op->kt_ival1)
230 seq_printf(m, "t1=%lld ",
231 (long long)ktime_to_us(op->kt_ival1));
232
233 if (op->kt_ival2)
234 seq_printf(m, "t2=%lld ",
235 (long long)ktime_to_us(op->kt_ival2));
236
237 seq_printf(m, "# sent %ld\n", op->frames_abs);
238 }
239 seq_putc(m, '\n');
240 return 0;
241}
242
243static int bcm_proc_open(struct inode *inode, struct file *file)
244{
245 return single_open_net(inode, file, bcm_proc_show);
246}
247
248static const struct file_operations bcm_proc_fops = {
249 .open = bcm_proc_open,
250 .read = seq_read,
251 .llseek = seq_lseek,
252 .release = single_release,
253};
254#endif /* CONFIG_PROC_FS */
255
256/*
257 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
258 * of the given bcm tx op
259 */
260static void bcm_can_tx(struct bcm_op *op)
261{
262 struct sk_buff *skb;
263 struct net_device *dev;
264 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
265
266 /* no target device? => exit */
267 if (!op->ifindex)
268 return;
269
270 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
271 if (!dev) {
272 /* RFC: should this bcm_op remove itself here? */
273 return;
274 }
275
276 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
277 if (!skb)
278 goto out;
279
280 can_skb_reserve(skb);
281 can_skb_prv(skb)->ifindex = dev->ifindex;
282 can_skb_prv(skb)->skbcnt = 0;
283
284 skb_put_data(skb, cf, op->cfsiz);
285
286 /* send with loopback */
287 skb->dev = dev;
288 can_skb_set_owner(skb, op->sk);
289 can_send(skb, 1);
290
291 /* update statistics */
292 op->currframe++;
293 op->frames_abs++;
294
295 /* reached last frame? */
296 if (op->currframe >= op->nframes)
297 op->currframe = 0;
298out:
299 dev_put(dev);
300}
301
302/*
303 * bcm_send_to_user - send a BCM message to the userspace
304 * (consisting of bcm_msg_head + x CAN frames)
305 */
306static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
307 struct canfd_frame *frames, int has_timestamp)
308{
309 struct sk_buff *skb;
310 struct canfd_frame *firstframe;
311 struct sockaddr_can *addr;
312 struct sock *sk = op->sk;
313 unsigned int datalen = head->nframes * op->cfsiz;
314 int err;
315
316 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
317 if (!skb)
318 return;
319
320 skb_put_data(skb, head, sizeof(*head));
321
322 if (head->nframes) {
323 /* CAN frames starting here */
324 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
325
326 skb_put_data(skb, frames, datalen);
327
328 /*
329 * the BCM uses the flags-element of the canfd_frame
330 * structure for internal purposes. This is only
331 * relevant for updates that are generated by the
332 * BCM, where nframes is 1
333 */
334 if (head->nframes == 1)
335 firstframe->flags &= BCM_CAN_FLAGS_MASK;
336 }
337
338 if (has_timestamp) {
339 /* restore rx timestamp */
340 skb->tstamp = op->rx_stamp;
341 }
342
343 /*
344 * Put the datagram to the queue so that bcm_recvmsg() can
345 * get it from there. We need to pass the interface index to
346 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
347 * containing the interface index.
348 */
349
350 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
351 addr = (struct sockaddr_can *)skb->cb;
352 memset(addr, 0, sizeof(*addr));
353 addr->can_family = AF_CAN;
354 addr->can_ifindex = op->rx_ifindex;
355
356 err = sock_queue_rcv_skb(sk, skb);
357 if (err < 0) {
358 struct bcm_sock *bo = bcm_sk(sk);
359
360 kfree_skb(skb);
361 /* don't care about overflows in this statistic */
362 bo->dropped_usr_msgs++;
363 }
364}
365
366static void bcm_tx_start_timer(struct bcm_op *op)
367{
368 if (op->kt_ival1 && op->count)
369 hrtimer_start(&op->timer,
370 ktime_add(ktime_get(), op->kt_ival1),
371 HRTIMER_MODE_ABS);
372 else if (op->kt_ival2)
373 hrtimer_start(&op->timer,
374 ktime_add(ktime_get(), op->kt_ival2),
375 HRTIMER_MODE_ABS);
376}
377
378static void bcm_tx_timeout_tsklet(unsigned long data)
379{
380 struct bcm_op *op = (struct bcm_op *)data;
381 struct bcm_msg_head msg_head;
382
383 if (op->kt_ival1 && (op->count > 0)) {
384
385 op->count--;
386 if (!op->count && (op->flags & TX_COUNTEVT)) {
387
388 /* create notification to user */
389 msg_head.opcode = TX_EXPIRED;
390 msg_head.flags = op->flags;
391 msg_head.count = op->count;
392 msg_head.ival1 = op->ival1;
393 msg_head.ival2 = op->ival2;
394 msg_head.can_id = op->can_id;
395 msg_head.nframes = 0;
396
397 bcm_send_to_user(op, &msg_head, NULL, 0);
398 }
399 bcm_can_tx(op);
400
401 } else if (op->kt_ival2)
402 bcm_can_tx(op);
403
404 bcm_tx_start_timer(op);
405}
406
407/*
408 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
409 */
410static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
411{
412 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
413
414 tasklet_schedule(&op->tsklet);
415
416 return HRTIMER_NORESTART;
417}
418
419/*
420 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
421 */
422static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
423{
424 struct bcm_msg_head head;
425
426 /* update statistics */
427 op->frames_filtered++;
428
429 /* prevent statistics overflow */
430 if (op->frames_filtered > ULONG_MAX/100)
431 op->frames_filtered = op->frames_abs = 0;
432
433 /* this element is not throttled anymore */
434 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
435
436 head.opcode = RX_CHANGED;
437 head.flags = op->flags;
438 head.count = op->count;
439 head.ival1 = op->ival1;
440 head.ival2 = op->ival2;
441 head.can_id = op->can_id;
442 head.nframes = 1;
443
444 bcm_send_to_user(op, &head, data, 1);
445}
446
447/*
448 * bcm_rx_update_and_send - process a detected relevant receive content change
449 * 1. update the last received data
450 * 2. send a notification to the user (if possible)
451 */
452static void bcm_rx_update_and_send(struct bcm_op *op,
453 struct canfd_frame *lastdata,
454 const struct canfd_frame *rxdata)
455{
456 memcpy(lastdata, rxdata, op->cfsiz);
457
458 /* mark as used and throttled by default */
459 lastdata->flags |= (RX_RECV|RX_THR);
460
461 /* throttling mode inactive ? */
462 if (!op->kt_ival2) {
463 /* send RX_CHANGED to the user immediately */
464 bcm_rx_changed(op, lastdata);
465 return;
466 }
467
468 /* with active throttling timer we are just done here */
469 if (hrtimer_active(&op->thrtimer))
470 return;
471
472 /* first reception with enabled throttling mode */
473 if (!op->kt_lastmsg)
474 goto rx_changed_settime;
475
476 /* got a second frame inside a potential throttle period? */
477 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
478 ktime_to_us(op->kt_ival2)) {
479 /* do not send the saved data - only start throttle timer */
480 hrtimer_start(&op->thrtimer,
481 ktime_add(op->kt_lastmsg, op->kt_ival2),
482 HRTIMER_MODE_ABS);
483 return;
484 }
485
486 /* the gap was that big, that throttling was not needed here */
487rx_changed_settime:
488 bcm_rx_changed(op, lastdata);
489 op->kt_lastmsg = ktime_get();
490}
491
492/*
493 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
494 * received data stored in op->last_frames[]
495 */
496static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
497 const struct canfd_frame *rxdata)
498{
499 struct canfd_frame *cf = op->frames + op->cfsiz * index;
500 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
501 int i;
502
503 /*
504 * no one uses the MSBs of flags for comparison,
505 * so we use it here to detect the first time of reception
506 */
507
508 if (!(lcf->flags & RX_RECV)) {
509 /* received data for the first time => send update to user */
510 bcm_rx_update_and_send(op, lcf, rxdata);
511 return;
512 }
513
514 /* do a real check in CAN frame data section */
515 for (i = 0; i < rxdata->len; i += 8) {
516 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
517 (get_u64(cf, i) & get_u64(lcf, i))) {
518 bcm_rx_update_and_send(op, lcf, rxdata);
519 return;
520 }
521 }
522
523 if (op->flags & RX_CHECK_DLC) {
524 /* do a real check in CAN frame length */
525 if (rxdata->len != lcf->len) {
526 bcm_rx_update_and_send(op, lcf, rxdata);
527 return;
528 }
529 }
530}
531
532/*
533 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
534 */
535static void bcm_rx_starttimer(struct bcm_op *op)
536{
537 if (op->flags & RX_NO_AUTOTIMER)
538 return;
539
540 if (op->kt_ival1)
541 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
542}
543
544static void bcm_rx_timeout_tsklet(unsigned long data)
545{
546 struct bcm_op *op = (struct bcm_op *)data;
547 struct bcm_msg_head msg_head;
548
549 /* create notification to user */
550 msg_head.opcode = RX_TIMEOUT;
551 msg_head.flags = op->flags;
552 msg_head.count = op->count;
553 msg_head.ival1 = op->ival1;
554 msg_head.ival2 = op->ival2;
555 msg_head.can_id = op->can_id;
556 msg_head.nframes = 0;
557
558 bcm_send_to_user(op, &msg_head, NULL, 0);
559}
560
561/*
562 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
563 */
564static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
565{
566 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
567
568 /* schedule before NET_RX_SOFTIRQ */
569 tasklet_hi_schedule(&op->tsklet);
570
571 /* no restart of the timer is done here! */
572
573 /* if user wants to be informed, when cyclic CAN-Messages come back */
574 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
575 /* clear received CAN frames to indicate 'nothing received' */
576 memset(op->last_frames, 0, op->nframes * op->cfsiz);
577 }
578
579 return HRTIMER_NORESTART;
580}
581
582/*
583 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
584 */
585static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
586 unsigned int index)
587{
588 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
589
590 if ((op->last_frames) && (lcf->flags & RX_THR)) {
591 if (update)
592 bcm_rx_changed(op, lcf);
593 return 1;
594 }
595 return 0;
596}
597
598/*
599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
600 *
601 * update == 0 : just check if throttled data is available (any irq context)
602 * update == 1 : check and send throttled data to userspace (soft_irq context)
603 */
604static int bcm_rx_thr_flush(struct bcm_op *op, int update)
605{
606 int updated = 0;
607
608 if (op->nframes > 1) {
609 unsigned int i;
610
611 /* for MUX filter we start at index 1 */
612 for (i = 1; i < op->nframes; i++)
613 updated += bcm_rx_do_flush(op, update, i);
614
615 } else {
616 /* for RX_FILTER_ID and simple filter */
617 updated += bcm_rx_do_flush(op, update, 0);
618 }
619
620 return updated;
621}
622
623static void bcm_rx_thr_tsklet(unsigned long data)
624{
625 struct bcm_op *op = (struct bcm_op *)data;
626
627 /* push the changed data to the userspace */
628 bcm_rx_thr_flush(op, 1);
629}
630
631/*
632 * bcm_rx_thr_handler - the time for blocked content updates is over now:
633 * Check for throttled data and send it to the userspace
634 */
635static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
636{
637 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
638
639 tasklet_schedule(&op->thrtsklet);
640
641 if (bcm_rx_thr_flush(op, 0)) {
642 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
643 return HRTIMER_RESTART;
644 } else {
645 /* rearm throttle handling */
646 op->kt_lastmsg = 0;
647 return HRTIMER_NORESTART;
648 }
649}
650
651/*
652 * bcm_rx_handler - handle a CAN frame reception
653 */
654static void bcm_rx_handler(struct sk_buff *skb, void *data)
655{
656 struct bcm_op *op = (struct bcm_op *)data;
657 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
658 unsigned int i;
659
660 if (op->can_id != rxframe->can_id)
661 return;
662
663 /* make sure to handle the correct frame type (CAN / CAN FD) */
664 if (skb->len != op->cfsiz)
665 return;
666
667 /* disable timeout */
668 hrtimer_cancel(&op->timer);
669
670 /* save rx timestamp */
671 op->rx_stamp = skb->tstamp;
672 /* save originator for recvfrom() */
673 op->rx_ifindex = skb->dev->ifindex;
674 /* update statistics */
675 op->frames_abs++;
676
677 if (op->flags & RX_RTR_FRAME) {
678 /* send reply for RTR-request (placed in op->frames[0]) */
679 bcm_can_tx(op);
680 return;
681 }
682
683 if (op->flags & RX_FILTER_ID) {
684 /* the easiest case */
685 bcm_rx_update_and_send(op, op->last_frames, rxframe);
686 goto rx_starttimer;
687 }
688
689 if (op->nframes == 1) {
690 /* simple compare with index 0 */
691 bcm_rx_cmp_to_index(op, 0, rxframe);
692 goto rx_starttimer;
693 }
694
695 if (op->nframes > 1) {
696 /*
697 * multiplex compare
698 *
699 * find the first multiplex mask that fits.
700 * Remark: The MUX-mask is stored in index 0 - but only the
701 * first 64 bits of the frame data[] are relevant (CAN FD)
702 */
703
704 for (i = 1; i < op->nframes; i++) {
705 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
706 (get_u64(op->frames, 0) &
707 get_u64(op->frames + op->cfsiz * i, 0))) {
708 bcm_rx_cmp_to_index(op, i, rxframe);
709 break;
710 }
711 }
712 }
713
714rx_starttimer:
715 bcm_rx_starttimer(op);
716}
717
718/*
719 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
720 */
721static struct bcm_op *bcm_find_op(struct list_head *ops,
722 struct bcm_msg_head *mh, int ifindex)
723{
724 struct bcm_op *op;
725
726 list_for_each_entry(op, ops, list) {
727 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
728 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
729 return op;
730 }
731
732 return NULL;
733}
734
735static void bcm_remove_op(struct bcm_op *op)
736{
737 if (op->tsklet.func) {
738 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
739 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
740 hrtimer_active(&op->timer)) {
741 hrtimer_cancel(&op->timer);
742 tasklet_kill(&op->tsklet);
743 }
744 }
745
746 if (op->thrtsklet.func) {
747 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
748 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
749 hrtimer_active(&op->thrtimer)) {
750 hrtimer_cancel(&op->thrtimer);
751 tasklet_kill(&op->thrtsklet);
752 }
753 }
754
755 if ((op->frames) && (op->frames != &op->sframe))
756 kfree(op->frames);
757
758 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
759 kfree(op->last_frames);
760
761 kfree(op);
762}
763
764static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
765{
766 if (op->rx_reg_dev == dev) {
767 can_rx_unregister(dev_net(dev), dev, op->can_id,
768 REGMASK(op->can_id), bcm_rx_handler, op);
769
770 /* mark as removed subscription */
771 op->rx_reg_dev = NULL;
772 } else
773 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
774 "mismatch %p %p\n", op->rx_reg_dev, dev);
775}
776
777/*
778 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
779 */
780static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
781 int ifindex)
782{
783 struct bcm_op *op, *n;
784
785 list_for_each_entry_safe(op, n, ops, list) {
786 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
787 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
788
789 /*
790 * Don't care if we're bound or not (due to netdev
791 * problems) can_rx_unregister() is always a save
792 * thing to do here.
793 */
794 if (op->ifindex) {
795 /*
796 * Only remove subscriptions that had not
797 * been removed due to NETDEV_UNREGISTER
798 * in bcm_notifier()
799 */
800 if (op->rx_reg_dev) {
801 struct net_device *dev;
802
803 dev = dev_get_by_index(sock_net(op->sk),
804 op->ifindex);
805 if (dev) {
806 bcm_rx_unreg(dev, op);
807 dev_put(dev);
808 }
809 }
810 } else
811 can_rx_unregister(sock_net(op->sk), NULL,
812 op->can_id,
813 REGMASK(op->can_id),
814 bcm_rx_handler, op);
815
816 list_del(&op->list);
817 bcm_remove_op(op);
818 return 1; /* done */
819 }
820 }
821
822 return 0; /* not found */
823}
824
825/*
826 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
827 */
828static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
829 int ifindex)
830{
831 struct bcm_op *op, *n;
832
833 list_for_each_entry_safe(op, n, ops, list) {
834 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
835 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
836 list_del(&op->list);
837 bcm_remove_op(op);
838 return 1; /* done */
839 }
840 }
841
842 return 0; /* not found */
843}
844
845/*
846 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
847 */
848static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
849 int ifindex)
850{
851 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
852
853 if (!op)
854 return -EINVAL;
855
856 /* put current values into msg_head */
857 msg_head->flags = op->flags;
858 msg_head->count = op->count;
859 msg_head->ival1 = op->ival1;
860 msg_head->ival2 = op->ival2;
861 msg_head->nframes = op->nframes;
862
863 bcm_send_to_user(op, msg_head, op->frames, 0);
864
865 return MHSIZ;
866}
867
868/*
869 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
870 */
871static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
872 int ifindex, struct sock *sk)
873{
874 struct bcm_sock *bo = bcm_sk(sk);
875 struct bcm_op *op;
876 struct canfd_frame *cf;
877 unsigned int i;
878 int err;
879
880 /* we need a real device to send frames */
881 if (!ifindex)
882 return -ENODEV;
883
884 /* check nframes boundaries - we need at least one CAN frame */
885 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
886 return -EINVAL;
887
888 /* check the given can_id */
889 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
890 if (op) {
891 /* update existing BCM operation */
892
893 /*
894 * Do we need more space for the CAN frames than currently
895 * allocated? -> This is a _really_ unusual use-case and
896 * therefore (complexity / locking) it is not supported.
897 */
898 if (msg_head->nframes > op->nframes)
899 return -E2BIG;
900
901 /* update CAN frames content */
902 for (i = 0; i < msg_head->nframes; i++) {
903
904 cf = op->frames + op->cfsiz * i;
905 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
906
907 if (op->flags & CAN_FD_FRAME) {
908 if (cf->len > 64)
909 err = -EINVAL;
910 } else {
911 if (cf->len > 8)
912 err = -EINVAL;
913 }
914
915 if (err < 0)
916 return err;
917
918 if (msg_head->flags & TX_CP_CAN_ID) {
919 /* copy can_id into frame */
920 cf->can_id = msg_head->can_id;
921 }
922 }
923 op->flags = msg_head->flags;
924
925 } else {
926 /* insert new BCM operation for the given can_id */
927
928 op = kzalloc(OPSIZ, GFP_KERNEL);
929 if (!op)
930 return -ENOMEM;
931
932 op->can_id = msg_head->can_id;
933 op->cfsiz = CFSIZ(msg_head->flags);
934 op->flags = msg_head->flags;
935
936 /* create array for CAN frames and copy the data */
937 if (msg_head->nframes > 1) {
938 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
939 GFP_KERNEL);
940 if (!op->frames) {
941 kfree(op);
942 return -ENOMEM;
943 }
944 } else
945 op->frames = &op->sframe;
946
947 for (i = 0; i < msg_head->nframes; i++) {
948
949 cf = op->frames + op->cfsiz * i;
950 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
951
952 if (op->flags & CAN_FD_FRAME) {
953 if (cf->len > 64)
954 err = -EINVAL;
955 } else {
956 if (cf->len > 8)
957 err = -EINVAL;
958 }
959
960 if (err < 0) {
961 if (op->frames != &op->sframe)
962 kfree(op->frames);
963 kfree(op);
964 return err;
965 }
966
967 if (msg_head->flags & TX_CP_CAN_ID) {
968 /* copy can_id into frame */
969 cf->can_id = msg_head->can_id;
970 }
971 }
972
973 /* tx_ops never compare with previous received messages */
974 op->last_frames = NULL;
975
976 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
977 op->sk = sk;
978 op->ifindex = ifindex;
979
980 /* initialize uninitialized (kzalloc) structure */
981 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
982 op->timer.function = bcm_tx_timeout_handler;
983
984 /* initialize tasklet for tx countevent notification */
985 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
986 (unsigned long) op);
987
988 /* currently unused in tx_ops */
989 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
990
991 /* add this bcm_op to the list of the tx_ops */
992 list_add(&op->list, &bo->tx_ops);
993
994 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
995
996 if (op->nframes != msg_head->nframes) {
997 op->nframes = msg_head->nframes;
998 /* start multiple frame transmission with index 0 */
999 op->currframe = 0;
1000 }
1001
1002 /* check flags */
1003
1004 if (op->flags & TX_RESET_MULTI_IDX) {
1005 /* start multiple frame transmission with index 0 */
1006 op->currframe = 0;
1007 }
1008
1009 if (op->flags & SETTIMER) {
1010 /* set timer values */
1011 op->count = msg_head->count;
1012 op->ival1 = msg_head->ival1;
1013 op->ival2 = msg_head->ival2;
1014 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1015 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1016
1017 /* disable an active timer due to zero values? */
1018 if (!op->kt_ival1 && !op->kt_ival2)
1019 hrtimer_cancel(&op->timer);
1020 }
1021
1022 if (op->flags & STARTTIMER) {
1023 hrtimer_cancel(&op->timer);
1024 /* spec: send CAN frame when starting timer */
1025 op->flags |= TX_ANNOUNCE;
1026 }
1027
1028 if (op->flags & TX_ANNOUNCE) {
1029 bcm_can_tx(op);
1030 if (op->count)
1031 op->count--;
1032 }
1033
1034 if (op->flags & STARTTIMER)
1035 bcm_tx_start_timer(op);
1036
1037 return msg_head->nframes * op->cfsiz + MHSIZ;
1038}
1039
1040/*
1041 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1042 */
1043static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1044 int ifindex, struct sock *sk)
1045{
1046 struct bcm_sock *bo = bcm_sk(sk);
1047 struct bcm_op *op;
1048 int do_rx_register;
1049 int err = 0;
1050
1051 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1052 /* be robust against wrong usage ... */
1053 msg_head->flags |= RX_FILTER_ID;
1054 /* ignore trailing garbage */
1055 msg_head->nframes = 0;
1056 }
1057
1058 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1059 if (msg_head->nframes > MAX_NFRAMES + 1)
1060 return -EINVAL;
1061
1062 if ((msg_head->flags & RX_RTR_FRAME) &&
1063 ((msg_head->nframes != 1) ||
1064 (!(msg_head->can_id & CAN_RTR_FLAG))))
1065 return -EINVAL;
1066
1067 /* check the given can_id */
1068 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1069 if (op) {
1070 /* update existing BCM operation */
1071
1072 /*
1073 * Do we need more space for the CAN frames than currently
1074 * allocated? -> This is a _really_ unusual use-case and
1075 * therefore (complexity / locking) it is not supported.
1076 */
1077 if (msg_head->nframes > op->nframes)
1078 return -E2BIG;
1079
1080 if (msg_head->nframes) {
1081 /* update CAN frames content */
1082 err = memcpy_from_msg(op->frames, msg,
1083 msg_head->nframes * op->cfsiz);
1084 if (err < 0)
1085 return err;
1086
1087 /* clear last_frames to indicate 'nothing received' */
1088 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1089 }
1090
1091 op->nframes = msg_head->nframes;
1092 op->flags = msg_head->flags;
1093
1094 /* Only an update -> do not call can_rx_register() */
1095 do_rx_register = 0;
1096
1097 } else {
1098 /* insert new BCM operation for the given can_id */
1099 op = kzalloc(OPSIZ, GFP_KERNEL);
1100 if (!op)
1101 return -ENOMEM;
1102
1103 op->can_id = msg_head->can_id;
1104 op->nframes = msg_head->nframes;
1105 op->cfsiz = CFSIZ(msg_head->flags);
1106 op->flags = msg_head->flags;
1107
1108 if (msg_head->nframes > 1) {
1109 /* create array for CAN frames and copy the data */
1110 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1111 GFP_KERNEL);
1112 if (!op->frames) {
1113 kfree(op);
1114 return -ENOMEM;
1115 }
1116
1117 /* create and init array for received CAN frames */
1118 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1119 GFP_KERNEL);
1120 if (!op->last_frames) {
1121 kfree(op->frames);
1122 kfree(op);
1123 return -ENOMEM;
1124 }
1125
1126 } else {
1127 op->frames = &op->sframe;
1128 op->last_frames = &op->last_sframe;
1129 }
1130
1131 if (msg_head->nframes) {
1132 err = memcpy_from_msg(op->frames, msg,
1133 msg_head->nframes * op->cfsiz);
1134 if (err < 0) {
1135 if (op->frames != &op->sframe)
1136 kfree(op->frames);
1137 if (op->last_frames != &op->last_sframe)
1138 kfree(op->last_frames);
1139 kfree(op);
1140 return err;
1141 }
1142 }
1143
1144 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1145 op->sk = sk;
1146 op->ifindex = ifindex;
1147
1148 /* ifindex for timeout events w/o previous frame reception */
1149 op->rx_ifindex = ifindex;
1150
1151 /* initialize uninitialized (kzalloc) structure */
1152 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1153 op->timer.function = bcm_rx_timeout_handler;
1154
1155 /* initialize tasklet for rx timeout notification */
1156 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1157 (unsigned long) op);
1158
1159 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1160 op->thrtimer.function = bcm_rx_thr_handler;
1161
1162 /* initialize tasklet for rx throttle handling */
1163 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1164 (unsigned long) op);
1165
1166 /* add this bcm_op to the list of the rx_ops */
1167 list_add(&op->list, &bo->rx_ops);
1168
1169 /* call can_rx_register() */
1170 do_rx_register = 1;
1171
1172 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1173
1174 /* check flags */
1175
1176 if (op->flags & RX_RTR_FRAME) {
1177 struct canfd_frame *frame0 = op->frames;
1178
1179 /* no timers in RTR-mode */
1180 hrtimer_cancel(&op->thrtimer);
1181 hrtimer_cancel(&op->timer);
1182
1183 /*
1184 * funny feature in RX(!)_SETUP only for RTR-mode:
1185 * copy can_id into frame BUT without RTR-flag to
1186 * prevent a full-load-loopback-test ... ;-]
1187 */
1188 if ((op->flags & TX_CP_CAN_ID) ||
1189 (frame0->can_id == op->can_id))
1190 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1191
1192 } else {
1193 if (op->flags & SETTIMER) {
1194
1195 /* set timer value */
1196 op->ival1 = msg_head->ival1;
1197 op->ival2 = msg_head->ival2;
1198 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1199 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1200
1201 /* disable an active timer due to zero value? */
1202 if (!op->kt_ival1)
1203 hrtimer_cancel(&op->timer);
1204
1205 /*
1206 * In any case cancel the throttle timer, flush
1207 * potentially blocked msgs and reset throttle handling
1208 */
1209 op->kt_lastmsg = 0;
1210 hrtimer_cancel(&op->thrtimer);
1211 bcm_rx_thr_flush(op, 1);
1212 }
1213
1214 if ((op->flags & STARTTIMER) && op->kt_ival1)
1215 hrtimer_start(&op->timer, op->kt_ival1,
1216 HRTIMER_MODE_REL);
1217 }
1218
1219 /* now we can register for can_ids, if we added a new bcm_op */
1220 if (do_rx_register) {
1221 if (ifindex) {
1222 struct net_device *dev;
1223
1224 dev = dev_get_by_index(sock_net(sk), ifindex);
1225 if (dev) {
1226 err = can_rx_register(sock_net(sk), dev,
1227 op->can_id,
1228 REGMASK(op->can_id),
1229 bcm_rx_handler, op,
1230 "bcm", sk);
1231
1232 op->rx_reg_dev = dev;
1233 dev_put(dev);
1234 }
1235
1236 } else
1237 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1238 REGMASK(op->can_id),
1239 bcm_rx_handler, op, "bcm", sk);
1240 if (err) {
1241 /* this bcm rx op is broken -> remove it */
1242 list_del(&op->list);
1243 bcm_remove_op(op);
1244 return err;
1245 }
1246 }
1247
1248 return msg_head->nframes * op->cfsiz + MHSIZ;
1249}
1250
1251/*
1252 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1253 */
1254static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1255 int cfsiz)
1256{
1257 struct sk_buff *skb;
1258 struct net_device *dev;
1259 int err;
1260
1261 /* we need a real device to send frames */
1262 if (!ifindex)
1263 return -ENODEV;
1264
1265 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1266 if (!skb)
1267 return -ENOMEM;
1268
1269 can_skb_reserve(skb);
1270
1271 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1272 if (err < 0) {
1273 kfree_skb(skb);
1274 return err;
1275 }
1276
1277 dev = dev_get_by_index(sock_net(sk), ifindex);
1278 if (!dev) {
1279 kfree_skb(skb);
1280 return -ENODEV;
1281 }
1282
1283 can_skb_prv(skb)->ifindex = dev->ifindex;
1284 can_skb_prv(skb)->skbcnt = 0;
1285 skb->dev = dev;
1286 can_skb_set_owner(skb, sk);
1287 err = can_send(skb, 1); /* send with loopback */
1288 dev_put(dev);
1289
1290 if (err)
1291 return err;
1292
1293 return cfsiz + MHSIZ;
1294}
1295
1296/*
1297 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1298 */
1299static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1300{
1301 struct sock *sk = sock->sk;
1302 struct bcm_sock *bo = bcm_sk(sk);
1303 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1304 struct bcm_msg_head msg_head;
1305 int cfsiz;
1306 int ret; /* read bytes or error codes as return value */
1307
1308 if (!bo->bound)
1309 return -ENOTCONN;
1310
1311 /* check for valid message length from userspace */
1312 if (size < MHSIZ)
1313 return -EINVAL;
1314
1315 /* read message head information */
1316 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1317 if (ret < 0)
1318 return ret;
1319
1320 cfsiz = CFSIZ(msg_head.flags);
1321 if ((size - MHSIZ) % cfsiz)
1322 return -EINVAL;
1323
1324 /* check for alternative ifindex for this bcm_op */
1325
1326 if (!ifindex && msg->msg_name) {
1327 /* no bound device as default => check msg_name */
1328 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1329
1330 if (msg->msg_namelen < sizeof(*addr))
1331 return -EINVAL;
1332
1333 if (addr->can_family != AF_CAN)
1334 return -EINVAL;
1335
1336 /* ifindex from sendto() */
1337 ifindex = addr->can_ifindex;
1338
1339 if (ifindex) {
1340 struct net_device *dev;
1341
1342 dev = dev_get_by_index(sock_net(sk), ifindex);
1343 if (!dev)
1344 return -ENODEV;
1345
1346 if (dev->type != ARPHRD_CAN) {
1347 dev_put(dev);
1348 return -ENODEV;
1349 }
1350
1351 dev_put(dev);
1352 }
1353 }
1354
1355 lock_sock(sk);
1356
1357 switch (msg_head.opcode) {
1358
1359 case TX_SETUP:
1360 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1361 break;
1362
1363 case RX_SETUP:
1364 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1365 break;
1366
1367 case TX_DELETE:
1368 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1369 ret = MHSIZ;
1370 else
1371 ret = -EINVAL;
1372 break;
1373
1374 case RX_DELETE:
1375 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1376 ret = MHSIZ;
1377 else
1378 ret = -EINVAL;
1379 break;
1380
1381 case TX_READ:
1382 /* reuse msg_head for the reply to TX_READ */
1383 msg_head.opcode = TX_STATUS;
1384 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1385 break;
1386
1387 case RX_READ:
1388 /* reuse msg_head for the reply to RX_READ */
1389 msg_head.opcode = RX_STATUS;
1390 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1391 break;
1392
1393 case TX_SEND:
1394 /* we need exactly one CAN frame behind the msg head */
1395 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1396 ret = -EINVAL;
1397 else
1398 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1399 break;
1400
1401 default:
1402 ret = -EINVAL;
1403 break;
1404 }
1405
1406 release_sock(sk);
1407
1408 return ret;
1409}
1410
1411/*
1412 * notification handler for netdevice status changes
1413 */
1414static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1415 void *ptr)
1416{
1417 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1418 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1419 struct sock *sk = &bo->sk;
1420 struct bcm_op *op;
1421 int notify_enodev = 0;
1422
1423 if (!net_eq(dev_net(dev), sock_net(sk)))
1424 return NOTIFY_DONE;
1425
1426 if (dev->type != ARPHRD_CAN)
1427 return NOTIFY_DONE;
1428
1429 switch (msg) {
1430
1431 case NETDEV_UNREGISTER:
1432 lock_sock(sk);
1433
1434 /* remove device specific receive entries */
1435 list_for_each_entry(op, &bo->rx_ops, list)
1436 if (op->rx_reg_dev == dev)
1437 bcm_rx_unreg(dev, op);
1438
1439 /* remove device reference, if this is our bound device */
1440 if (bo->bound && bo->ifindex == dev->ifindex) {
1441 bo->bound = 0;
1442 bo->ifindex = 0;
1443 notify_enodev = 1;
1444 }
1445
1446 release_sock(sk);
1447
1448 if (notify_enodev) {
1449 sk->sk_err = ENODEV;
1450 if (!sock_flag(sk, SOCK_DEAD))
1451 sk->sk_error_report(sk);
1452 }
1453 break;
1454
1455 case NETDEV_DOWN:
1456 if (bo->bound && bo->ifindex == dev->ifindex) {
1457 sk->sk_err = ENETDOWN;
1458 if (!sock_flag(sk, SOCK_DEAD))
1459 sk->sk_error_report(sk);
1460 }
1461 }
1462
1463 return NOTIFY_DONE;
1464}
1465
1466/*
1467 * initial settings for all BCM sockets to be set at socket creation time
1468 */
1469static int bcm_init(struct sock *sk)
1470{
1471 struct bcm_sock *bo = bcm_sk(sk);
1472
1473 bo->bound = 0;
1474 bo->ifindex = 0;
1475 bo->dropped_usr_msgs = 0;
1476 bo->bcm_proc_read = NULL;
1477
1478 INIT_LIST_HEAD(&bo->tx_ops);
1479 INIT_LIST_HEAD(&bo->rx_ops);
1480
1481 /* set notifier */
1482 bo->notifier.notifier_call = bcm_notifier;
1483
1484 register_netdevice_notifier(&bo->notifier);
1485
1486 return 0;
1487}
1488
1489/*
1490 * standard socket functions
1491 */
1492static int bcm_release(struct socket *sock)
1493{
1494 struct sock *sk = sock->sk;
1495 struct net *net;
1496 struct bcm_sock *bo;
1497 struct bcm_op *op, *next;
1498
1499 if (!sk)
1500 return 0;
1501
1502 net = sock_net(sk);
1503 bo = bcm_sk(sk);
1504
1505 /* remove bcm_ops, timer, rx_unregister(), etc. */
1506
1507 unregister_netdevice_notifier(&bo->notifier);
1508
1509 lock_sock(sk);
1510
1511 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1512 bcm_remove_op(op);
1513
1514 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1515 /*
1516 * Don't care if we're bound or not (due to netdev problems)
1517 * can_rx_unregister() is always a save thing to do here.
1518 */
1519 if (op->ifindex) {
1520 /*
1521 * Only remove subscriptions that had not
1522 * been removed due to NETDEV_UNREGISTER
1523 * in bcm_notifier()
1524 */
1525 if (op->rx_reg_dev) {
1526 struct net_device *dev;
1527
1528 dev = dev_get_by_index(net, op->ifindex);
1529 if (dev) {
1530 bcm_rx_unreg(dev, op);
1531 dev_put(dev);
1532 }
1533 }
1534 } else
1535 can_rx_unregister(net, NULL, op->can_id,
1536 REGMASK(op->can_id),
1537 bcm_rx_handler, op);
1538
1539 bcm_remove_op(op);
1540 }
1541
1542#if IS_ENABLED(CONFIG_PROC_FS)
1543 /* remove procfs entry */
1544 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1545 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1546#endif /* CONFIG_PROC_FS */
1547
1548 /* remove device reference */
1549 if (bo->bound) {
1550 bo->bound = 0;
1551 bo->ifindex = 0;
1552 }
1553
1554 sock_orphan(sk);
1555 sock->sk = NULL;
1556
1557 release_sock(sk);
1558 sock_put(sk);
1559
1560 return 0;
1561}
1562
1563static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1564 int flags)
1565{
1566 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1567 struct sock *sk = sock->sk;
1568 struct bcm_sock *bo = bcm_sk(sk);
1569 struct net *net = sock_net(sk);
1570 int ret = 0;
1571
1572 if (len < sizeof(*addr))
1573 return -EINVAL;
1574
1575 lock_sock(sk);
1576
1577 if (bo->bound) {
1578 ret = -EISCONN;
1579 goto fail;
1580 }
1581
1582 /* bind a device to this socket */
1583 if (addr->can_ifindex) {
1584 struct net_device *dev;
1585
1586 dev = dev_get_by_index(net, addr->can_ifindex);
1587 if (!dev) {
1588 ret = -ENODEV;
1589 goto fail;
1590 }
1591 if (dev->type != ARPHRD_CAN) {
1592 dev_put(dev);
1593 ret = -ENODEV;
1594 goto fail;
1595 }
1596
1597 bo->ifindex = dev->ifindex;
1598 dev_put(dev);
1599
1600 } else {
1601 /* no interface reference for ifindex = 0 ('any' CAN device) */
1602 bo->ifindex = 0;
1603 }
1604
1605#if IS_ENABLED(CONFIG_PROC_FS)
1606 if (net->can.bcmproc_dir) {
1607 /* unique socket address as filename */
1608 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1609 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1610 net->can.bcmproc_dir,
1611 &bcm_proc_fops, sk);
1612 if (!bo->bcm_proc_read) {
1613 ret = -ENOMEM;
1614 goto fail;
1615 }
1616 }
1617#endif /* CONFIG_PROC_FS */
1618
1619 bo->bound = 1;
1620
1621fail:
1622 release_sock(sk);
1623
1624 return ret;
1625}
1626
1627static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1628 int flags)
1629{
1630 struct sock *sk = sock->sk;
1631 struct sk_buff *skb;
1632 int error = 0;
1633 int noblock;
1634 int err;
1635
1636 noblock = flags & MSG_DONTWAIT;
1637 flags &= ~MSG_DONTWAIT;
1638 skb = skb_recv_datagram(sk, flags, noblock, &error);
1639 if (!skb)
1640 return error;
1641
1642 if (skb->len < size)
1643 size = skb->len;
1644
1645 err = memcpy_to_msg(msg, skb->data, size);
1646 if (err < 0) {
1647 skb_free_datagram(sk, skb);
1648 return err;
1649 }
1650
1651 sock_recv_ts_and_drops(msg, sk, skb);
1652
1653 if (msg->msg_name) {
1654 __sockaddr_check_size(sizeof(struct sockaddr_can));
1655 msg->msg_namelen = sizeof(struct sockaddr_can);
1656 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1657 }
1658
1659 skb_free_datagram(sk, skb);
1660
1661 return size;
1662}
1663
1664static const struct proto_ops bcm_ops = {
1665 .family = PF_CAN,
1666 .release = bcm_release,
1667 .bind = sock_no_bind,
1668 .connect = bcm_connect,
1669 .socketpair = sock_no_socketpair,
1670 .accept = sock_no_accept,
1671 .getname = sock_no_getname,
1672 .poll = datagram_poll,
1673 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1674 .listen = sock_no_listen,
1675 .shutdown = sock_no_shutdown,
1676 .setsockopt = sock_no_setsockopt,
1677 .getsockopt = sock_no_getsockopt,
1678 .sendmsg = bcm_sendmsg,
1679 .recvmsg = bcm_recvmsg,
1680 .mmap = sock_no_mmap,
1681 .sendpage = sock_no_sendpage,
1682};
1683
1684static struct proto bcm_proto __read_mostly = {
1685 .name = "CAN_BCM",
1686 .owner = THIS_MODULE,
1687 .obj_size = sizeof(struct bcm_sock),
1688 .init = bcm_init,
1689};
1690
1691static const struct can_proto bcm_can_proto = {
1692 .type = SOCK_DGRAM,
1693 .protocol = CAN_BCM,
1694 .ops = &bcm_ops,
1695 .prot = &bcm_proto,
1696};
1697
1698static int canbcm_pernet_init(struct net *net)
1699{
1700#if IS_ENABLED(CONFIG_PROC_FS)
1701 /* create /proc/net/can-bcm directory */
1702 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1703#endif /* CONFIG_PROC_FS */
1704
1705 return 0;
1706}
1707
1708static void canbcm_pernet_exit(struct net *net)
1709{
1710#if IS_ENABLED(CONFIG_PROC_FS)
1711 /* remove /proc/net/can-bcm directory */
1712 if (net->can.bcmproc_dir)
1713 remove_proc_entry("can-bcm", net->proc_net);
1714#endif /* CONFIG_PROC_FS */
1715}
1716
1717static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1718 .init = canbcm_pernet_init,
1719 .exit = canbcm_pernet_exit,
1720};
1721
1722static int __init bcm_module_init(void)
1723{
1724 int err;
1725
1726 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1727
1728 err = can_proto_register(&bcm_can_proto);
1729 if (err < 0) {
1730 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1731 return err;
1732 }
1733
1734 register_pernet_subsys(&canbcm_pernet_ops);
1735 return 0;
1736}
1737
1738static void __exit bcm_module_exit(void)
1739{
1740 can_proto_unregister(&bcm_can_proto);
1741 unregister_pernet_subsys(&canbcm_pernet_ops);
1742}
1743
1744module_init(bcm_module_init);
1745module_exit(bcm_module_exit);