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1/*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2016 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42#include <linux/module.h>
43#include <linux/init.h>
44#include <linux/interrupt.h>
45#include <linux/hrtimer.h>
46#include <linux/list.h>
47#include <linux/proc_fs.h>
48#include <linux/seq_file.h>
49#include <linux/uio.h>
50#include <linux/net.h>
51#include <linux/netdevice.h>
52#include <linux/socket.h>
53#include <linux/if_arp.h>
54#include <linux/skbuff.h>
55#include <linux/can.h>
56#include <linux/can/core.h>
57#include <linux/can/skb.h>
58#include <linux/can/bcm.h>
59#include <linux/slab.h>
60#include <net/sock.h>
61#include <net/net_namespace.h>
62
63/*
64 * To send multiple CAN frame content within TX_SETUP or to filter
65 * CAN messages with multiplex index within RX_SETUP, the number of
66 * different filters is limited to 256 due to the one byte index value.
67 */
68#define MAX_NFRAMES 256
69
70/* use of last_frames[index].flags */
71#define RX_RECV 0x40 /* received data for this element */
72#define RX_THR 0x80 /* element not been sent due to throttle feature */
73#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
74
75/* get best masking value for can_rx_register() for a given single can_id */
76#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
77 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
78 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
79
80#define CAN_BCM_VERSION "20161123"
81
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
121static struct proc_dir_entry *proc_dir;
122
123struct bcm_sock {
124 struct sock sk;
125 int bound;
126 int ifindex;
127 struct notifier_block notifier;
128 struct list_head rx_ops;
129 struct list_head tx_ops;
130 unsigned long dropped_usr_msgs;
131 struct proc_dir_entry *bcm_proc_read;
132 char procname [32]; /* inode number in decimal with \0 */
133};
134
135static inline struct bcm_sock *bcm_sk(const struct sock *sk)
136{
137 return (struct bcm_sock *)sk;
138}
139
140static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
141{
142 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
143}
144
145#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
146#define OPSIZ sizeof(struct bcm_op)
147#define MHSIZ sizeof(struct bcm_msg_head)
148
149/*
150 * procfs functions
151 */
152static char *bcm_proc_getifname(char *result, int ifindex)
153{
154 struct net_device *dev;
155
156 if (!ifindex)
157 return "any";
158
159 rcu_read_lock();
160 dev = dev_get_by_index_rcu(&init_net, ifindex);
161 if (dev)
162 strcpy(result, dev->name);
163 else
164 strcpy(result, "???");
165 rcu_read_unlock();
166
167 return result;
168}
169
170static int bcm_proc_show(struct seq_file *m, void *v)
171{
172 char ifname[IFNAMSIZ];
173 struct sock *sk = (struct sock *)m->private;
174 struct bcm_sock *bo = bcm_sk(sk);
175 struct bcm_op *op;
176
177 seq_printf(m, ">>> socket %pK", sk->sk_socket);
178 seq_printf(m, " / sk %pK", sk);
179 seq_printf(m, " / bo %pK", bo);
180 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
181 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
182 seq_printf(m, " <<<\n");
183
184 list_for_each_entry(op, &bo->rx_ops, list) {
185
186 unsigned long reduction;
187
188 /* print only active entries & prevent division by zero */
189 if (!op->frames_abs)
190 continue;
191
192 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
193 bcm_proc_getifname(ifname, op->ifindex));
194
195 if (op->flags & CAN_FD_FRAME)
196 seq_printf(m, "(%u)", op->nframes);
197 else
198 seq_printf(m, "[%u]", op->nframes);
199
200 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
201
202 if (op->kt_ival1)
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(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(file, bcm_proc_show, PDE_DATA(inode));
246}
247
248static const struct file_operations bcm_proc_fops = {
249 .owner = THIS_MODULE,
250 .open = bcm_proc_open,
251 .read = seq_read,
252 .llseek = seq_lseek,
253 .release = single_release,
254};
255
256/*
257 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
258 * of the given bcm tx op
259 */
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(&init_net, op->ifindex);
271 if (!dev) {
272 /* RFC: should this bcm_op remove itself here? */
273 return;
274 }
275
276 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
277 if (!skb)
278 goto out;
279
280 can_skb_reserve(skb);
281 can_skb_prv(skb)->ifindex = dev->ifindex;
282 can_skb_prv(skb)->skbcnt = 0;
283
284 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz);
285
286 /* send with loopback */
287 skb->dev = dev;
288 can_skb_set_owner(skb, op->sk);
289 can_send(skb, 1);
290
291 /* update statistics */
292 op->currframe++;
293 op->frames_abs++;
294
295 /* reached last frame? */
296 if (op->currframe >= op->nframes)
297 op->currframe = 0;
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 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
321
322 if (head->nframes) {
323 /* CAN frames starting here */
324 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
325
326 memcpy(skb_put(skb, datalen), frames, datalen);
327
328 /*
329 * the BCM uses the flags-element of the canfd_frame
330 * structure for internal purposes. This is only
331 * relevant for updates that are generated by the
332 * BCM, where nframes is 1
333 */
334 if (head->nframes == 1)
335 firstframe->flags &= BCM_CAN_FLAGS_MASK;
336 }
337
338 if (has_timestamp) {
339 /* restore rx timestamp */
340 skb->tstamp = op->rx_stamp;
341 }
342
343 /*
344 * Put the datagram to the queue so that bcm_recvmsg() can
345 * get it from there. We need to pass the interface index to
346 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
347 * containing the interface index.
348 */
349
350 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
351 addr = (struct sockaddr_can *)skb->cb;
352 memset(addr, 0, sizeof(*addr));
353 addr->can_family = AF_CAN;
354 addr->can_ifindex = op->rx_ifindex;
355
356 err = sock_queue_rcv_skb(sk, skb);
357 if (err < 0) {
358 struct bcm_sock *bo = bcm_sk(sk);
359
360 kfree_skb(skb);
361 /* don't care about overflows in this statistic */
362 bo->dropped_usr_msgs++;
363 }
364}
365
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, op->can_id, REGMASK(op->can_id),
768 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(&init_net,
804 op->ifindex);
805 if (dev) {
806 bcm_rx_unreg(dev, op);
807 dev_put(dev);
808 }
809 }
810 } else
811 can_rx_unregister(NULL, op->can_id,
812 REGMASK(op->can_id),
813 bcm_rx_handler, op);
814
815 list_del(&op->list);
816 bcm_remove_op(op);
817 return 1; /* done */
818 }
819 }
820
821 return 0; /* not found */
822}
823
824/*
825 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
826 */
827static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
828 int ifindex)
829{
830 struct bcm_op *op, *n;
831
832 list_for_each_entry_safe(op, n, ops, list) {
833 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
834 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
835 list_del(&op->list);
836 bcm_remove_op(op);
837 return 1; /* done */
838 }
839 }
840
841 return 0; /* not found */
842}
843
844/*
845 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
846 */
847static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
848 int ifindex)
849{
850 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
851
852 if (!op)
853 return -EINVAL;
854
855 /* put current values into msg_head */
856 msg_head->flags = op->flags;
857 msg_head->count = op->count;
858 msg_head->ival1 = op->ival1;
859 msg_head->ival2 = op->ival2;
860 msg_head->nframes = op->nframes;
861
862 bcm_send_to_user(op, msg_head, op->frames, 0);
863
864 return MHSIZ;
865}
866
867/*
868 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
869 */
870static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
871 int ifindex, struct sock *sk)
872{
873 struct bcm_sock *bo = bcm_sk(sk);
874 struct bcm_op *op;
875 struct canfd_frame *cf;
876 unsigned int i;
877 int err;
878
879 /* we need a real device to send frames */
880 if (!ifindex)
881 return -ENODEV;
882
883 /* check nframes boundaries - we need at least one CAN frame */
884 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
885 return -EINVAL;
886
887 /* check the given can_id */
888 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
889 if (op) {
890 /* update existing BCM operation */
891
892 /*
893 * Do we need more space for the CAN frames than currently
894 * allocated? -> This is a _really_ unusual use-case and
895 * therefore (complexity / locking) it is not supported.
896 */
897 if (msg_head->nframes > op->nframes)
898 return -E2BIG;
899
900 /* update CAN frames content */
901 for (i = 0; i < msg_head->nframes; i++) {
902
903 cf = op->frames + op->cfsiz * i;
904 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
905
906 if (op->flags & CAN_FD_FRAME) {
907 if (cf->len > 64)
908 err = -EINVAL;
909 } else {
910 if (cf->len > 8)
911 err = -EINVAL;
912 }
913
914 if (err < 0)
915 return err;
916
917 if (msg_head->flags & TX_CP_CAN_ID) {
918 /* copy can_id into frame */
919 cf->can_id = msg_head->can_id;
920 }
921 }
922 op->flags = msg_head->flags;
923
924 } else {
925 /* insert new BCM operation for the given can_id */
926
927 op = kzalloc(OPSIZ, GFP_KERNEL);
928 if (!op)
929 return -ENOMEM;
930
931 op->can_id = msg_head->can_id;
932 op->cfsiz = CFSIZ(msg_head->flags);
933 op->flags = msg_head->flags;
934
935 /* create array for CAN frames and copy the data */
936 if (msg_head->nframes > 1) {
937 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
938 GFP_KERNEL);
939 if (!op->frames) {
940 kfree(op);
941 return -ENOMEM;
942 }
943 } else
944 op->frames = &op->sframe;
945
946 for (i = 0; i < msg_head->nframes; i++) {
947
948 cf = op->frames + op->cfsiz * i;
949 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
950
951 if (op->flags & CAN_FD_FRAME) {
952 if (cf->len > 64)
953 err = -EINVAL;
954 } else {
955 if (cf->len > 8)
956 err = -EINVAL;
957 }
958
959 if (err < 0) {
960 if (op->frames != &op->sframe)
961 kfree(op->frames);
962 kfree(op);
963 return err;
964 }
965
966 if (msg_head->flags & TX_CP_CAN_ID) {
967 /* copy can_id into frame */
968 cf->can_id = msg_head->can_id;
969 }
970 }
971
972 /* tx_ops never compare with previous received messages */
973 op->last_frames = NULL;
974
975 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
976 op->sk = sk;
977 op->ifindex = ifindex;
978
979 /* initialize uninitialized (kzalloc) structure */
980 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
981 op->timer.function = bcm_tx_timeout_handler;
982
983 /* initialize tasklet for tx countevent notification */
984 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
985 (unsigned long) op);
986
987 /* currently unused in tx_ops */
988 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
989
990 /* add this bcm_op to the list of the tx_ops */
991 list_add(&op->list, &bo->tx_ops);
992
993 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
994
995 if (op->nframes != msg_head->nframes) {
996 op->nframes = msg_head->nframes;
997 /* start multiple frame transmission with index 0 */
998 op->currframe = 0;
999 }
1000
1001 /* check flags */
1002
1003 if (op->flags & TX_RESET_MULTI_IDX) {
1004 /* start multiple frame transmission with index 0 */
1005 op->currframe = 0;
1006 }
1007
1008 if (op->flags & SETTIMER) {
1009 /* set timer values */
1010 op->count = msg_head->count;
1011 op->ival1 = msg_head->ival1;
1012 op->ival2 = msg_head->ival2;
1013 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1014 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1015
1016 /* disable an active timer due to zero values? */
1017 if (!op->kt_ival1 && !op->kt_ival2)
1018 hrtimer_cancel(&op->timer);
1019 }
1020
1021 if (op->flags & STARTTIMER) {
1022 hrtimer_cancel(&op->timer);
1023 /* spec: send CAN frame when starting timer */
1024 op->flags |= TX_ANNOUNCE;
1025 }
1026
1027 if (op->flags & TX_ANNOUNCE) {
1028 bcm_can_tx(op);
1029 if (op->count)
1030 op->count--;
1031 }
1032
1033 if (op->flags & STARTTIMER)
1034 bcm_tx_start_timer(op);
1035
1036 return msg_head->nframes * op->cfsiz + MHSIZ;
1037}
1038
1039/*
1040 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1041 */
1042static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1043 int ifindex, struct sock *sk)
1044{
1045 struct bcm_sock *bo = bcm_sk(sk);
1046 struct bcm_op *op;
1047 int do_rx_register;
1048 int err = 0;
1049
1050 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1051 /* be robust against wrong usage ... */
1052 msg_head->flags |= RX_FILTER_ID;
1053 /* ignore trailing garbage */
1054 msg_head->nframes = 0;
1055 }
1056
1057 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1058 if (msg_head->nframes > MAX_NFRAMES + 1)
1059 return -EINVAL;
1060
1061 if ((msg_head->flags & RX_RTR_FRAME) &&
1062 ((msg_head->nframes != 1) ||
1063 (!(msg_head->can_id & CAN_RTR_FLAG))))
1064 return -EINVAL;
1065
1066 /* check the given can_id */
1067 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1068 if (op) {
1069 /* update existing BCM operation */
1070
1071 /*
1072 * Do we need more space for the CAN frames than currently
1073 * allocated? -> This is a _really_ unusual use-case and
1074 * therefore (complexity / locking) it is not supported.
1075 */
1076 if (msg_head->nframes > op->nframes)
1077 return -E2BIG;
1078
1079 if (msg_head->nframes) {
1080 /* update CAN frames content */
1081 err = memcpy_from_msg(op->frames, msg,
1082 msg_head->nframes * op->cfsiz);
1083 if (err < 0)
1084 return err;
1085
1086 /* clear last_frames to indicate 'nothing received' */
1087 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1088 }
1089
1090 op->nframes = msg_head->nframes;
1091 op->flags = msg_head->flags;
1092
1093 /* Only an update -> do not call can_rx_register() */
1094 do_rx_register = 0;
1095
1096 } else {
1097 /* insert new BCM operation for the given can_id */
1098 op = kzalloc(OPSIZ, GFP_KERNEL);
1099 if (!op)
1100 return -ENOMEM;
1101
1102 op->can_id = msg_head->can_id;
1103 op->nframes = msg_head->nframes;
1104 op->cfsiz = CFSIZ(msg_head->flags);
1105 op->flags = msg_head->flags;
1106
1107 if (msg_head->nframes > 1) {
1108 /* create array for CAN frames and copy the data */
1109 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1110 GFP_KERNEL);
1111 if (!op->frames) {
1112 kfree(op);
1113 return -ENOMEM;
1114 }
1115
1116 /* create and init array for received CAN frames */
1117 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1118 GFP_KERNEL);
1119 if (!op->last_frames) {
1120 kfree(op->frames);
1121 kfree(op);
1122 return -ENOMEM;
1123 }
1124
1125 } else {
1126 op->frames = &op->sframe;
1127 op->last_frames = &op->last_sframe;
1128 }
1129
1130 if (msg_head->nframes) {
1131 err = memcpy_from_msg(op->frames, msg,
1132 msg_head->nframes * op->cfsiz);
1133 if (err < 0) {
1134 if (op->frames != &op->sframe)
1135 kfree(op->frames);
1136 if (op->last_frames != &op->last_sframe)
1137 kfree(op->last_frames);
1138 kfree(op);
1139 return err;
1140 }
1141 }
1142
1143 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1144 op->sk = sk;
1145 op->ifindex = ifindex;
1146
1147 /* ifindex for timeout events w/o previous frame reception */
1148 op->rx_ifindex = ifindex;
1149
1150 /* initialize uninitialized (kzalloc) structure */
1151 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1152 op->timer.function = bcm_rx_timeout_handler;
1153
1154 /* initialize tasklet for rx timeout notification */
1155 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1156 (unsigned long) op);
1157
1158 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1159 op->thrtimer.function = bcm_rx_thr_handler;
1160
1161 /* initialize tasklet for rx throttle handling */
1162 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1163 (unsigned long) op);
1164
1165 /* add this bcm_op to the list of the rx_ops */
1166 list_add(&op->list, &bo->rx_ops);
1167
1168 /* call can_rx_register() */
1169 do_rx_register = 1;
1170
1171 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1172
1173 /* check flags */
1174
1175 if (op->flags & RX_RTR_FRAME) {
1176 struct canfd_frame *frame0 = op->frames;
1177
1178 /* no timers in RTR-mode */
1179 hrtimer_cancel(&op->thrtimer);
1180 hrtimer_cancel(&op->timer);
1181
1182 /*
1183 * funny feature in RX(!)_SETUP only for RTR-mode:
1184 * copy can_id into frame BUT without RTR-flag to
1185 * prevent a full-load-loopback-test ... ;-]
1186 */
1187 if ((op->flags & TX_CP_CAN_ID) ||
1188 (frame0->can_id == op->can_id))
1189 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1190
1191 } else {
1192 if (op->flags & SETTIMER) {
1193
1194 /* set timer value */
1195 op->ival1 = msg_head->ival1;
1196 op->ival2 = msg_head->ival2;
1197 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1198 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1199
1200 /* disable an active timer due to zero value? */
1201 if (!op->kt_ival1)
1202 hrtimer_cancel(&op->timer);
1203
1204 /*
1205 * In any case cancel the throttle timer, flush
1206 * potentially blocked msgs and reset throttle handling
1207 */
1208 op->kt_lastmsg = 0;
1209 hrtimer_cancel(&op->thrtimer);
1210 bcm_rx_thr_flush(op, 1);
1211 }
1212
1213 if ((op->flags & STARTTIMER) && op->kt_ival1)
1214 hrtimer_start(&op->timer, op->kt_ival1,
1215 HRTIMER_MODE_REL);
1216 }
1217
1218 /* now we can register for can_ids, if we added a new bcm_op */
1219 if (do_rx_register) {
1220 if (ifindex) {
1221 struct net_device *dev;
1222
1223 dev = dev_get_by_index(&init_net, ifindex);
1224 if (dev) {
1225 err = can_rx_register(dev, op->can_id,
1226 REGMASK(op->can_id),
1227 bcm_rx_handler, op,
1228 "bcm", sk);
1229
1230 op->rx_reg_dev = dev;
1231 dev_put(dev);
1232 }
1233
1234 } else
1235 err = can_rx_register(NULL, op->can_id,
1236 REGMASK(op->can_id),
1237 bcm_rx_handler, op, "bcm", sk);
1238 if (err) {
1239 /* this bcm rx op is broken -> remove it */
1240 list_del(&op->list);
1241 bcm_remove_op(op);
1242 return err;
1243 }
1244 }
1245
1246 return msg_head->nframes * op->cfsiz + MHSIZ;
1247}
1248
1249/*
1250 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1251 */
1252static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1253 int cfsiz)
1254{
1255 struct sk_buff *skb;
1256 struct net_device *dev;
1257 int err;
1258
1259 /* we need a real device to send frames */
1260 if (!ifindex)
1261 return -ENODEV;
1262
1263 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1264 if (!skb)
1265 return -ENOMEM;
1266
1267 can_skb_reserve(skb);
1268
1269 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1270 if (err < 0) {
1271 kfree_skb(skb);
1272 return err;
1273 }
1274
1275 dev = dev_get_by_index(&init_net, ifindex);
1276 if (!dev) {
1277 kfree_skb(skb);
1278 return -ENODEV;
1279 }
1280
1281 can_skb_prv(skb)->ifindex = dev->ifindex;
1282 can_skb_prv(skb)->skbcnt = 0;
1283 skb->dev = dev;
1284 can_skb_set_owner(skb, sk);
1285 err = can_send(skb, 1); /* send with loopback */
1286 dev_put(dev);
1287
1288 if (err)
1289 return err;
1290
1291 return cfsiz + MHSIZ;
1292}
1293
1294/*
1295 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1296 */
1297static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1298{
1299 struct sock *sk = sock->sk;
1300 struct bcm_sock *bo = bcm_sk(sk);
1301 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1302 struct bcm_msg_head msg_head;
1303 int cfsiz;
1304 int ret; /* read bytes or error codes as return value */
1305
1306 if (!bo->bound)
1307 return -ENOTCONN;
1308
1309 /* check for valid message length from userspace */
1310 if (size < MHSIZ)
1311 return -EINVAL;
1312
1313 /* read message head information */
1314 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1315 if (ret < 0)
1316 return ret;
1317
1318 cfsiz = CFSIZ(msg_head.flags);
1319 if ((size - MHSIZ) % cfsiz)
1320 return -EINVAL;
1321
1322 /* check for alternative ifindex for this bcm_op */
1323
1324 if (!ifindex && msg->msg_name) {
1325 /* no bound device as default => check msg_name */
1326 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1327
1328 if (msg->msg_namelen < sizeof(*addr))
1329 return -EINVAL;
1330
1331 if (addr->can_family != AF_CAN)
1332 return -EINVAL;
1333
1334 /* ifindex from sendto() */
1335 ifindex = addr->can_ifindex;
1336
1337 if (ifindex) {
1338 struct net_device *dev;
1339
1340 dev = dev_get_by_index(&init_net, ifindex);
1341 if (!dev)
1342 return -ENODEV;
1343
1344 if (dev->type != ARPHRD_CAN) {
1345 dev_put(dev);
1346 return -ENODEV;
1347 }
1348
1349 dev_put(dev);
1350 }
1351 }
1352
1353 lock_sock(sk);
1354
1355 switch (msg_head.opcode) {
1356
1357 case TX_SETUP:
1358 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1359 break;
1360
1361 case RX_SETUP:
1362 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1363 break;
1364
1365 case TX_DELETE:
1366 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1367 ret = MHSIZ;
1368 else
1369 ret = -EINVAL;
1370 break;
1371
1372 case RX_DELETE:
1373 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1374 ret = MHSIZ;
1375 else
1376 ret = -EINVAL;
1377 break;
1378
1379 case TX_READ:
1380 /* reuse msg_head for the reply to TX_READ */
1381 msg_head.opcode = TX_STATUS;
1382 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1383 break;
1384
1385 case RX_READ:
1386 /* reuse msg_head for the reply to RX_READ */
1387 msg_head.opcode = RX_STATUS;
1388 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1389 break;
1390
1391 case TX_SEND:
1392 /* we need exactly one CAN frame behind the msg head */
1393 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1394 ret = -EINVAL;
1395 else
1396 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1397 break;
1398
1399 default:
1400 ret = -EINVAL;
1401 break;
1402 }
1403
1404 release_sock(sk);
1405
1406 return ret;
1407}
1408
1409/*
1410 * notification handler for netdevice status changes
1411 */
1412static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1413 void *ptr)
1414{
1415 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1416 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1417 struct sock *sk = &bo->sk;
1418 struct bcm_op *op;
1419 int notify_enodev = 0;
1420
1421 if (!net_eq(dev_net(dev), &init_net))
1422 return NOTIFY_DONE;
1423
1424 if (dev->type != ARPHRD_CAN)
1425 return NOTIFY_DONE;
1426
1427 switch (msg) {
1428
1429 case NETDEV_UNREGISTER:
1430 lock_sock(sk);
1431
1432 /* remove device specific receive entries */
1433 list_for_each_entry(op, &bo->rx_ops, list)
1434 if (op->rx_reg_dev == dev)
1435 bcm_rx_unreg(dev, op);
1436
1437 /* remove device reference, if this is our bound device */
1438 if (bo->bound && bo->ifindex == dev->ifindex) {
1439 bo->bound = 0;
1440 bo->ifindex = 0;
1441 notify_enodev = 1;
1442 }
1443
1444 release_sock(sk);
1445
1446 if (notify_enodev) {
1447 sk->sk_err = ENODEV;
1448 if (!sock_flag(sk, SOCK_DEAD))
1449 sk->sk_error_report(sk);
1450 }
1451 break;
1452
1453 case NETDEV_DOWN:
1454 if (bo->bound && bo->ifindex == dev->ifindex) {
1455 sk->sk_err = ENETDOWN;
1456 if (!sock_flag(sk, SOCK_DEAD))
1457 sk->sk_error_report(sk);
1458 }
1459 }
1460
1461 return NOTIFY_DONE;
1462}
1463
1464/*
1465 * initial settings for all BCM sockets to be set at socket creation time
1466 */
1467static int bcm_init(struct sock *sk)
1468{
1469 struct bcm_sock *bo = bcm_sk(sk);
1470
1471 bo->bound = 0;
1472 bo->ifindex = 0;
1473 bo->dropped_usr_msgs = 0;
1474 bo->bcm_proc_read = NULL;
1475
1476 INIT_LIST_HEAD(&bo->tx_ops);
1477 INIT_LIST_HEAD(&bo->rx_ops);
1478
1479 /* set notifier */
1480 bo->notifier.notifier_call = bcm_notifier;
1481
1482 register_netdevice_notifier(&bo->notifier);
1483
1484 return 0;
1485}
1486
1487/*
1488 * standard socket functions
1489 */
1490static int bcm_release(struct socket *sock)
1491{
1492 struct sock *sk = sock->sk;
1493 struct bcm_sock *bo;
1494 struct bcm_op *op, *next;
1495
1496 if (sk == NULL)
1497 return 0;
1498
1499 bo = bcm_sk(sk);
1500
1501 /* remove bcm_ops, timer, rx_unregister(), etc. */
1502
1503 unregister_netdevice_notifier(&bo->notifier);
1504
1505 lock_sock(sk);
1506
1507 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1508 bcm_remove_op(op);
1509
1510 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1511 /*
1512 * Don't care if we're bound or not (due to netdev problems)
1513 * can_rx_unregister() is always a save thing to do here.
1514 */
1515 if (op->ifindex) {
1516 /*
1517 * Only remove subscriptions that had not
1518 * been removed due to NETDEV_UNREGISTER
1519 * in bcm_notifier()
1520 */
1521 if (op->rx_reg_dev) {
1522 struct net_device *dev;
1523
1524 dev = dev_get_by_index(&init_net, op->ifindex);
1525 if (dev) {
1526 bcm_rx_unreg(dev, op);
1527 dev_put(dev);
1528 }
1529 }
1530 } else
1531 can_rx_unregister(NULL, op->can_id,
1532 REGMASK(op->can_id),
1533 bcm_rx_handler, op);
1534
1535 bcm_remove_op(op);
1536 }
1537
1538 /* remove procfs entry */
1539 if (proc_dir && bo->bcm_proc_read)
1540 remove_proc_entry(bo->procname, proc_dir);
1541
1542 /* remove device reference */
1543 if (bo->bound) {
1544 bo->bound = 0;
1545 bo->ifindex = 0;
1546 }
1547
1548 sock_orphan(sk);
1549 sock->sk = NULL;
1550
1551 release_sock(sk);
1552 sock_put(sk);
1553
1554 return 0;
1555}
1556
1557static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1558 int flags)
1559{
1560 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1561 struct sock *sk = sock->sk;
1562 struct bcm_sock *bo = bcm_sk(sk);
1563 int ret = 0;
1564
1565 if (len < sizeof(*addr))
1566 return -EINVAL;
1567
1568 lock_sock(sk);
1569
1570 if (bo->bound) {
1571 ret = -EISCONN;
1572 goto fail;
1573 }
1574
1575 /* bind a device to this socket */
1576 if (addr->can_ifindex) {
1577 struct net_device *dev;
1578
1579 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1580 if (!dev) {
1581 ret = -ENODEV;
1582 goto fail;
1583 }
1584 if (dev->type != ARPHRD_CAN) {
1585 dev_put(dev);
1586 ret = -ENODEV;
1587 goto fail;
1588 }
1589
1590 bo->ifindex = dev->ifindex;
1591 dev_put(dev);
1592
1593 } else {
1594 /* no interface reference for ifindex = 0 ('any' CAN device) */
1595 bo->ifindex = 0;
1596 }
1597
1598 if (proc_dir) {
1599 /* unique socket address as filename */
1600 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1601 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1602 proc_dir,
1603 &bcm_proc_fops, sk);
1604 if (!bo->bcm_proc_read) {
1605 ret = -ENOMEM;
1606 goto fail;
1607 }
1608 }
1609
1610 bo->bound = 1;
1611
1612fail:
1613 release_sock(sk);
1614
1615 return ret;
1616}
1617
1618static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1619 int flags)
1620{
1621 struct sock *sk = sock->sk;
1622 struct sk_buff *skb;
1623 int error = 0;
1624 int noblock;
1625 int err;
1626
1627 noblock = flags & MSG_DONTWAIT;
1628 flags &= ~MSG_DONTWAIT;
1629 skb = skb_recv_datagram(sk, flags, noblock, &error);
1630 if (!skb)
1631 return error;
1632
1633 if (skb->len < size)
1634 size = skb->len;
1635
1636 err = memcpy_to_msg(msg, skb->data, size);
1637 if (err < 0) {
1638 skb_free_datagram(sk, skb);
1639 return err;
1640 }
1641
1642 sock_recv_ts_and_drops(msg, sk, skb);
1643
1644 if (msg->msg_name) {
1645 __sockaddr_check_size(sizeof(struct sockaddr_can));
1646 msg->msg_namelen = sizeof(struct sockaddr_can);
1647 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1648 }
1649
1650 skb_free_datagram(sk, skb);
1651
1652 return size;
1653}
1654
1655static const struct proto_ops bcm_ops = {
1656 .family = PF_CAN,
1657 .release = bcm_release,
1658 .bind = sock_no_bind,
1659 .connect = bcm_connect,
1660 .socketpair = sock_no_socketpair,
1661 .accept = sock_no_accept,
1662 .getname = sock_no_getname,
1663 .poll = datagram_poll,
1664 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1665 .listen = sock_no_listen,
1666 .shutdown = sock_no_shutdown,
1667 .setsockopt = sock_no_setsockopt,
1668 .getsockopt = sock_no_getsockopt,
1669 .sendmsg = bcm_sendmsg,
1670 .recvmsg = bcm_recvmsg,
1671 .mmap = sock_no_mmap,
1672 .sendpage = sock_no_sendpage,
1673};
1674
1675static struct proto bcm_proto __read_mostly = {
1676 .name = "CAN_BCM",
1677 .owner = THIS_MODULE,
1678 .obj_size = sizeof(struct bcm_sock),
1679 .init = bcm_init,
1680};
1681
1682static const struct can_proto bcm_can_proto = {
1683 .type = SOCK_DGRAM,
1684 .protocol = CAN_BCM,
1685 .ops = &bcm_ops,
1686 .prot = &bcm_proto,
1687};
1688
1689static int __init bcm_module_init(void)
1690{
1691 int err;
1692
1693 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1694
1695 err = can_proto_register(&bcm_can_proto);
1696 if (err < 0) {
1697 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1698 return err;
1699 }
1700
1701 /* create /proc/net/can-bcm directory */
1702 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1703 return 0;
1704}
1705
1706static void __exit bcm_module_exit(void)
1707{
1708 can_proto_unregister(&bcm_can_proto);
1709
1710 if (proc_dir)
1711 remove_proc_entry("can-bcm", init_net.proc_net);
1712}
1713
1714module_init(bcm_module_init);
1715module_exit(bcm_module_exit);
1/*
2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
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].can_dlc */
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_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
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 CAN_VERSION
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/* easy access to can_frame payload */
88static inline u64 GET_U64(const struct can_frame *cp)
89{
90 return *(u64 *)cp->data;
91}
92
93struct bcm_op {
94 struct list_head list;
95 int ifindex;
96 canid_t can_id;
97 u32 flags;
98 unsigned long frames_abs, frames_filtered;
99 struct bcm_timeval ival1, ival2;
100 struct hrtimer timer, thrtimer;
101 struct tasklet_struct tsklet, thrtsklet;
102 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
103 int rx_ifindex;
104 u32 count;
105 u32 nframes;
106 u32 currframe;
107 struct can_frame *frames;
108 struct can_frame *last_frames;
109 struct can_frame sframe;
110 struct can_frame last_sframe;
111 struct sock *sk;
112 struct net_device *rx_reg_dev;
113};
114
115static struct proc_dir_entry *proc_dir;
116
117struct bcm_sock {
118 struct sock sk;
119 int bound;
120 int ifindex;
121 struct notifier_block notifier;
122 struct list_head rx_ops;
123 struct list_head tx_ops;
124 unsigned long dropped_usr_msgs;
125 struct proc_dir_entry *bcm_proc_read;
126 char procname [32]; /* inode number in decimal with \0 */
127};
128
129static inline struct bcm_sock *bcm_sk(const struct sock *sk)
130{
131 return (struct bcm_sock *)sk;
132}
133
134static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
135{
136 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
137}
138
139#define CFSIZ sizeof(struct can_frame)
140#define OPSIZ sizeof(struct bcm_op)
141#define MHSIZ sizeof(struct bcm_msg_head)
142
143/*
144 * procfs functions
145 */
146static char *bcm_proc_getifname(char *result, int ifindex)
147{
148 struct net_device *dev;
149
150 if (!ifindex)
151 return "any";
152
153 rcu_read_lock();
154 dev = dev_get_by_index_rcu(&init_net, ifindex);
155 if (dev)
156 strcpy(result, dev->name);
157 else
158 strcpy(result, "???");
159 rcu_read_unlock();
160
161 return result;
162}
163
164static int bcm_proc_show(struct seq_file *m, void *v)
165{
166 char ifname[IFNAMSIZ];
167 struct sock *sk = (struct sock *)m->private;
168 struct bcm_sock *bo = bcm_sk(sk);
169 struct bcm_op *op;
170
171 seq_printf(m, ">>> socket %pK", sk->sk_socket);
172 seq_printf(m, " / sk %pK", sk);
173 seq_printf(m, " / bo %pK", bo);
174 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
175 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
176 seq_printf(m, " <<<\n");
177
178 list_for_each_entry(op, &bo->rx_ops, list) {
179
180 unsigned long reduction;
181
182 /* print only active entries & prevent division by zero */
183 if (!op->frames_abs)
184 continue;
185
186 seq_printf(m, "rx_op: %03X %-5s ",
187 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
188 seq_printf(m, "[%u]%c ", op->nframes,
189 (op->flags & RX_CHECK_DLC)?'d':' ');
190 if (op->kt_ival1.tv64)
191 seq_printf(m, "timeo=%lld ",
192 (long long)
193 ktime_to_us(op->kt_ival1));
194
195 if (op->kt_ival2.tv64)
196 seq_printf(m, "thr=%lld ",
197 (long long)
198 ktime_to_us(op->kt_ival2));
199
200 seq_printf(m, "# recv %ld (%ld) => reduction: ",
201 op->frames_filtered, op->frames_abs);
202
203 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
204
205 seq_printf(m, "%s%ld%%\n",
206 (reduction == 100)?"near ":"", reduction);
207 }
208
209 list_for_each_entry(op, &bo->tx_ops, list) {
210
211 seq_printf(m, "tx_op: %03X %s [%u] ",
212 op->can_id,
213 bcm_proc_getifname(ifname, op->ifindex),
214 op->nframes);
215
216 if (op->kt_ival1.tv64)
217 seq_printf(m, "t1=%lld ",
218 (long long) ktime_to_us(op->kt_ival1));
219
220 if (op->kt_ival2.tv64)
221 seq_printf(m, "t2=%lld ",
222 (long long) ktime_to_us(op->kt_ival2));
223
224 seq_printf(m, "# sent %ld\n", op->frames_abs);
225 }
226 seq_putc(m, '\n');
227 return 0;
228}
229
230static int bcm_proc_open(struct inode *inode, struct file *file)
231{
232 return single_open(file, bcm_proc_show, PDE_DATA(inode));
233}
234
235static const struct file_operations bcm_proc_fops = {
236 .owner = THIS_MODULE,
237 .open = bcm_proc_open,
238 .read = seq_read,
239 .llseek = seq_lseek,
240 .release = single_release,
241};
242
243/*
244 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
245 * of the given bcm tx op
246 */
247static void bcm_can_tx(struct bcm_op *op)
248{
249 struct sk_buff *skb;
250 struct net_device *dev;
251 struct can_frame *cf = &op->frames[op->currframe];
252
253 /* no target device? => exit */
254 if (!op->ifindex)
255 return;
256
257 dev = dev_get_by_index(&init_net, op->ifindex);
258 if (!dev) {
259 /* RFC: should this bcm_op remove itself here? */
260 return;
261 }
262
263 skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), gfp_any());
264 if (!skb)
265 goto out;
266
267 can_skb_reserve(skb);
268 can_skb_prv(skb)->ifindex = dev->ifindex;
269 can_skb_prv(skb)->skbcnt = 0;
270
271 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
272
273 /* send with loopback */
274 skb->dev = dev;
275 can_skb_set_owner(skb, op->sk);
276 can_send(skb, 1);
277
278 /* update statistics */
279 op->currframe++;
280 op->frames_abs++;
281
282 /* reached last frame? */
283 if (op->currframe >= op->nframes)
284 op->currframe = 0;
285 out:
286 dev_put(dev);
287}
288
289/*
290 * bcm_send_to_user - send a BCM message to the userspace
291 * (consisting of bcm_msg_head + x CAN frames)
292 */
293static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
294 struct can_frame *frames, int has_timestamp)
295{
296 struct sk_buff *skb;
297 struct can_frame *firstframe;
298 struct sockaddr_can *addr;
299 struct sock *sk = op->sk;
300 unsigned int datalen = head->nframes * CFSIZ;
301 int err;
302
303 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
304 if (!skb)
305 return;
306
307 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
308
309 if (head->nframes) {
310 /* can_frames starting here */
311 firstframe = (struct can_frame *)skb_tail_pointer(skb);
312
313 memcpy(skb_put(skb, datalen), frames, datalen);
314
315 /*
316 * the BCM uses the can_dlc-element of the can_frame
317 * structure for internal purposes. This is only
318 * relevant for updates that are generated by the
319 * BCM, where nframes is 1
320 */
321 if (head->nframes == 1)
322 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
323 }
324
325 if (has_timestamp) {
326 /* restore rx timestamp */
327 skb->tstamp = op->rx_stamp;
328 }
329
330 /*
331 * Put the datagram to the queue so that bcm_recvmsg() can
332 * get it from there. We need to pass the interface index to
333 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
334 * containing the interface index.
335 */
336
337 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
338 addr = (struct sockaddr_can *)skb->cb;
339 memset(addr, 0, sizeof(*addr));
340 addr->can_family = AF_CAN;
341 addr->can_ifindex = op->rx_ifindex;
342
343 err = sock_queue_rcv_skb(sk, skb);
344 if (err < 0) {
345 struct bcm_sock *bo = bcm_sk(sk);
346
347 kfree_skb(skb);
348 /* don't care about overflows in this statistic */
349 bo->dropped_usr_msgs++;
350 }
351}
352
353static void bcm_tx_start_timer(struct bcm_op *op)
354{
355 if (op->kt_ival1.tv64 && op->count)
356 hrtimer_start(&op->timer,
357 ktime_add(ktime_get(), op->kt_ival1),
358 HRTIMER_MODE_ABS);
359 else if (op->kt_ival2.tv64)
360 hrtimer_start(&op->timer,
361 ktime_add(ktime_get(), op->kt_ival2),
362 HRTIMER_MODE_ABS);
363}
364
365static void bcm_tx_timeout_tsklet(unsigned long data)
366{
367 struct bcm_op *op = (struct bcm_op *)data;
368 struct bcm_msg_head msg_head;
369
370 if (op->kt_ival1.tv64 && (op->count > 0)) {
371
372 op->count--;
373 if (!op->count && (op->flags & TX_COUNTEVT)) {
374
375 /* create notification to user */
376 msg_head.opcode = TX_EXPIRED;
377 msg_head.flags = op->flags;
378 msg_head.count = op->count;
379 msg_head.ival1 = op->ival1;
380 msg_head.ival2 = op->ival2;
381 msg_head.can_id = op->can_id;
382 msg_head.nframes = 0;
383
384 bcm_send_to_user(op, &msg_head, NULL, 0);
385 }
386 bcm_can_tx(op);
387
388 } else if (op->kt_ival2.tv64)
389 bcm_can_tx(op);
390
391 bcm_tx_start_timer(op);
392}
393
394/*
395 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
396 */
397static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
398{
399 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
400
401 tasklet_schedule(&op->tsklet);
402
403 return HRTIMER_NORESTART;
404}
405
406/*
407 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
408 */
409static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
410{
411 struct bcm_msg_head head;
412
413 /* update statistics */
414 op->frames_filtered++;
415
416 /* prevent statistics overflow */
417 if (op->frames_filtered > ULONG_MAX/100)
418 op->frames_filtered = op->frames_abs = 0;
419
420 /* this element is not throttled anymore */
421 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
422
423 head.opcode = RX_CHANGED;
424 head.flags = op->flags;
425 head.count = op->count;
426 head.ival1 = op->ival1;
427 head.ival2 = op->ival2;
428 head.can_id = op->can_id;
429 head.nframes = 1;
430
431 bcm_send_to_user(op, &head, data, 1);
432}
433
434/*
435 * bcm_rx_update_and_send - process a detected relevant receive content change
436 * 1. update the last received data
437 * 2. send a notification to the user (if possible)
438 */
439static void bcm_rx_update_and_send(struct bcm_op *op,
440 struct can_frame *lastdata,
441 const struct can_frame *rxdata)
442{
443 memcpy(lastdata, rxdata, CFSIZ);
444
445 /* mark as used and throttled by default */
446 lastdata->can_dlc |= (RX_RECV|RX_THR);
447
448 /* throttling mode inactive ? */
449 if (!op->kt_ival2.tv64) {
450 /* send RX_CHANGED to the user immediately */
451 bcm_rx_changed(op, lastdata);
452 return;
453 }
454
455 /* with active throttling timer we are just done here */
456 if (hrtimer_active(&op->thrtimer))
457 return;
458
459 /* first reception with enabled throttling mode */
460 if (!op->kt_lastmsg.tv64)
461 goto rx_changed_settime;
462
463 /* got a second frame inside a potential throttle period? */
464 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
465 ktime_to_us(op->kt_ival2)) {
466 /* do not send the saved data - only start throttle timer */
467 hrtimer_start(&op->thrtimer,
468 ktime_add(op->kt_lastmsg, op->kt_ival2),
469 HRTIMER_MODE_ABS);
470 return;
471 }
472
473 /* the gap was that big, that throttling was not needed here */
474rx_changed_settime:
475 bcm_rx_changed(op, lastdata);
476 op->kt_lastmsg = ktime_get();
477}
478
479/*
480 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
481 * received data stored in op->last_frames[]
482 */
483static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
484 const struct can_frame *rxdata)
485{
486 /*
487 * no one uses the MSBs of can_dlc for comparison,
488 * so we use it here to detect the first time of reception
489 */
490
491 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
492 /* received data for the first time => send update to user */
493 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
494 return;
495 }
496
497 /* do a real check in can_frame data section */
498
499 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
500 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
501 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
502 return;
503 }
504
505 if (op->flags & RX_CHECK_DLC) {
506 /* do a real check in can_frame dlc */
507 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
508 BCM_CAN_DLC_MASK)) {
509 bcm_rx_update_and_send(op, &op->last_frames[index],
510 rxdata);
511 return;
512 }
513 }
514}
515
516/*
517 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
518 */
519static void bcm_rx_starttimer(struct bcm_op *op)
520{
521 if (op->flags & RX_NO_AUTOTIMER)
522 return;
523
524 if (op->kt_ival1.tv64)
525 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
526}
527
528static void bcm_rx_timeout_tsklet(unsigned long data)
529{
530 struct bcm_op *op = (struct bcm_op *)data;
531 struct bcm_msg_head msg_head;
532
533 /* create notification to user */
534 msg_head.opcode = RX_TIMEOUT;
535 msg_head.flags = op->flags;
536 msg_head.count = op->count;
537 msg_head.ival1 = op->ival1;
538 msg_head.ival2 = op->ival2;
539 msg_head.can_id = op->can_id;
540 msg_head.nframes = 0;
541
542 bcm_send_to_user(op, &msg_head, NULL, 0);
543}
544
545/*
546 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
547 */
548static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
549{
550 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
551
552 /* schedule before NET_RX_SOFTIRQ */
553 tasklet_hi_schedule(&op->tsklet);
554
555 /* no restart of the timer is done here! */
556
557 /* if user wants to be informed, when cyclic CAN-Messages come back */
558 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
559 /* clear received can_frames to indicate 'nothing received' */
560 memset(op->last_frames, 0, op->nframes * CFSIZ);
561 }
562
563 return HRTIMER_NORESTART;
564}
565
566/*
567 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
568 */
569static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
570 unsigned int index)
571{
572 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
573 if (update)
574 bcm_rx_changed(op, &op->last_frames[index]);
575 return 1;
576 }
577 return 0;
578}
579
580/*
581 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
582 *
583 * update == 0 : just check if throttled data is available (any irq context)
584 * update == 1 : check and send throttled data to userspace (soft_irq context)
585 */
586static int bcm_rx_thr_flush(struct bcm_op *op, int update)
587{
588 int updated = 0;
589
590 if (op->nframes > 1) {
591 unsigned int i;
592
593 /* for MUX filter we start at index 1 */
594 for (i = 1; i < op->nframes; i++)
595 updated += bcm_rx_do_flush(op, update, i);
596
597 } else {
598 /* for RX_FILTER_ID and simple filter */
599 updated += bcm_rx_do_flush(op, update, 0);
600 }
601
602 return updated;
603}
604
605static void bcm_rx_thr_tsklet(unsigned long data)
606{
607 struct bcm_op *op = (struct bcm_op *)data;
608
609 /* push the changed data to the userspace */
610 bcm_rx_thr_flush(op, 1);
611}
612
613/*
614 * bcm_rx_thr_handler - the time for blocked content updates is over now:
615 * Check for throttled data and send it to the userspace
616 */
617static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
618{
619 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
620
621 tasklet_schedule(&op->thrtsklet);
622
623 if (bcm_rx_thr_flush(op, 0)) {
624 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
625 return HRTIMER_RESTART;
626 } else {
627 /* rearm throttle handling */
628 op->kt_lastmsg = ktime_set(0, 0);
629 return HRTIMER_NORESTART;
630 }
631}
632
633/*
634 * bcm_rx_handler - handle a CAN frame reception
635 */
636static void bcm_rx_handler(struct sk_buff *skb, void *data)
637{
638 struct bcm_op *op = (struct bcm_op *)data;
639 const struct can_frame *rxframe = (struct can_frame *)skb->data;
640 unsigned int i;
641
642 /* disable timeout */
643 hrtimer_cancel(&op->timer);
644
645 if (op->can_id != rxframe->can_id)
646 return;
647
648 /* save rx timestamp */
649 op->rx_stamp = skb->tstamp;
650 /* save originator for recvfrom() */
651 op->rx_ifindex = skb->dev->ifindex;
652 /* update statistics */
653 op->frames_abs++;
654
655 if (op->flags & RX_RTR_FRAME) {
656 /* send reply for RTR-request (placed in op->frames[0]) */
657 bcm_can_tx(op);
658 return;
659 }
660
661 if (op->flags & RX_FILTER_ID) {
662 /* the easiest case */
663 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
664 goto rx_starttimer;
665 }
666
667 if (op->nframes == 1) {
668 /* simple compare with index 0 */
669 bcm_rx_cmp_to_index(op, 0, rxframe);
670 goto rx_starttimer;
671 }
672
673 if (op->nframes > 1) {
674 /*
675 * multiplex compare
676 *
677 * find the first multiplex mask that fits.
678 * Remark: The MUX-mask is stored in index 0
679 */
680
681 for (i = 1; i < op->nframes; i++) {
682 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
683 (GET_U64(&op->frames[0]) &
684 GET_U64(&op->frames[i]))) {
685 bcm_rx_cmp_to_index(op, i, rxframe);
686 break;
687 }
688 }
689 }
690
691rx_starttimer:
692 bcm_rx_starttimer(op);
693}
694
695/*
696 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
697 */
698static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
699 int ifindex)
700{
701 struct bcm_op *op;
702
703 list_for_each_entry(op, ops, list) {
704 if ((op->can_id == can_id) && (op->ifindex == ifindex))
705 return op;
706 }
707
708 return NULL;
709}
710
711static void bcm_remove_op(struct bcm_op *op)
712{
713 hrtimer_cancel(&op->timer);
714 hrtimer_cancel(&op->thrtimer);
715
716 if (op->tsklet.func)
717 tasklet_kill(&op->tsklet);
718
719 if (op->thrtsklet.func)
720 tasklet_kill(&op->thrtsklet);
721
722 if ((op->frames) && (op->frames != &op->sframe))
723 kfree(op->frames);
724
725 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
726 kfree(op->last_frames);
727
728 kfree(op);
729}
730
731static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
732{
733 if (op->rx_reg_dev == dev) {
734 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
735 bcm_rx_handler, op);
736
737 /* mark as removed subscription */
738 op->rx_reg_dev = NULL;
739 } else
740 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
741 "mismatch %p %p\n", op->rx_reg_dev, dev);
742}
743
744/*
745 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
746 */
747static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
748{
749 struct bcm_op *op, *n;
750
751 list_for_each_entry_safe(op, n, ops, list) {
752 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
753
754 /*
755 * Don't care if we're bound or not (due to netdev
756 * problems) can_rx_unregister() is always a save
757 * thing to do here.
758 */
759 if (op->ifindex) {
760 /*
761 * Only remove subscriptions that had not
762 * been removed due to NETDEV_UNREGISTER
763 * in bcm_notifier()
764 */
765 if (op->rx_reg_dev) {
766 struct net_device *dev;
767
768 dev = dev_get_by_index(&init_net,
769 op->ifindex);
770 if (dev) {
771 bcm_rx_unreg(dev, op);
772 dev_put(dev);
773 }
774 }
775 } else
776 can_rx_unregister(NULL, op->can_id,
777 REGMASK(op->can_id),
778 bcm_rx_handler, op);
779
780 list_del(&op->list);
781 bcm_remove_op(op);
782 return 1; /* done */
783 }
784 }
785
786 return 0; /* not found */
787}
788
789/*
790 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
791 */
792static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
793{
794 struct bcm_op *op, *n;
795
796 list_for_each_entry_safe(op, n, ops, list) {
797 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
798 list_del(&op->list);
799 bcm_remove_op(op);
800 return 1; /* done */
801 }
802 }
803
804 return 0; /* not found */
805}
806
807/*
808 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
809 */
810static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
811 int ifindex)
812{
813 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
814
815 if (!op)
816 return -EINVAL;
817
818 /* put current values into msg_head */
819 msg_head->flags = op->flags;
820 msg_head->count = op->count;
821 msg_head->ival1 = op->ival1;
822 msg_head->ival2 = op->ival2;
823 msg_head->nframes = op->nframes;
824
825 bcm_send_to_user(op, msg_head, op->frames, 0);
826
827 return MHSIZ;
828}
829
830/*
831 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
832 */
833static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
834 int ifindex, struct sock *sk)
835{
836 struct bcm_sock *bo = bcm_sk(sk);
837 struct bcm_op *op;
838 unsigned int i;
839 int err;
840
841 /* we need a real device to send frames */
842 if (!ifindex)
843 return -ENODEV;
844
845 /* check nframes boundaries - we need at least one can_frame */
846 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
847 return -EINVAL;
848
849 /* check the given can_id */
850 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
851
852 if (op) {
853 /* update existing BCM operation */
854
855 /*
856 * Do we need more space for the can_frames than currently
857 * allocated? -> This is a _really_ unusual use-case and
858 * therefore (complexity / locking) it is not supported.
859 */
860 if (msg_head->nframes > op->nframes)
861 return -E2BIG;
862
863 /* update can_frames content */
864 for (i = 0; i < msg_head->nframes; i++) {
865 err = memcpy_from_msg((u8 *)&op->frames[i], msg, CFSIZ);
866
867 if (op->frames[i].can_dlc > 8)
868 err = -EINVAL;
869
870 if (err < 0)
871 return err;
872
873 if (msg_head->flags & TX_CP_CAN_ID) {
874 /* copy can_id into frame */
875 op->frames[i].can_id = msg_head->can_id;
876 }
877 }
878
879 } else {
880 /* insert new BCM operation for the given can_id */
881
882 op = kzalloc(OPSIZ, GFP_KERNEL);
883 if (!op)
884 return -ENOMEM;
885
886 op->can_id = msg_head->can_id;
887
888 /* create array for can_frames and copy the data */
889 if (msg_head->nframes > 1) {
890 op->frames = kmalloc(msg_head->nframes * CFSIZ,
891 GFP_KERNEL);
892 if (!op->frames) {
893 kfree(op);
894 return -ENOMEM;
895 }
896 } else
897 op->frames = &op->sframe;
898
899 for (i = 0; i < msg_head->nframes; i++) {
900 err = memcpy_from_msg((u8 *)&op->frames[i], msg, CFSIZ);
901
902 if (op->frames[i].can_dlc > 8)
903 err = -EINVAL;
904
905 if (err < 0) {
906 if (op->frames != &op->sframe)
907 kfree(op->frames);
908 kfree(op);
909 return err;
910 }
911
912 if (msg_head->flags & TX_CP_CAN_ID) {
913 /* copy can_id into frame */
914 op->frames[i].can_id = msg_head->can_id;
915 }
916 }
917
918 /* tx_ops never compare with previous received messages */
919 op->last_frames = NULL;
920
921 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
922 op->sk = sk;
923 op->ifindex = ifindex;
924
925 /* initialize uninitialized (kzalloc) structure */
926 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
927 op->timer.function = bcm_tx_timeout_handler;
928
929 /* initialize tasklet for tx countevent notification */
930 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
931 (unsigned long) op);
932
933 /* currently unused in tx_ops */
934 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
935
936 /* add this bcm_op to the list of the tx_ops */
937 list_add(&op->list, &bo->tx_ops);
938
939 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
940
941 if (op->nframes != msg_head->nframes) {
942 op->nframes = msg_head->nframes;
943 /* start multiple frame transmission with index 0 */
944 op->currframe = 0;
945 }
946
947 /* check flags */
948
949 op->flags = msg_head->flags;
950
951 if (op->flags & TX_RESET_MULTI_IDX) {
952 /* start multiple frame transmission with index 0 */
953 op->currframe = 0;
954 }
955
956 if (op->flags & SETTIMER) {
957 /* set timer values */
958 op->count = msg_head->count;
959 op->ival1 = msg_head->ival1;
960 op->ival2 = msg_head->ival2;
961 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
962 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
963
964 /* disable an active timer due to zero values? */
965 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
966 hrtimer_cancel(&op->timer);
967 }
968
969 if (op->flags & STARTTIMER) {
970 hrtimer_cancel(&op->timer);
971 /* spec: send can_frame when starting timer */
972 op->flags |= TX_ANNOUNCE;
973 }
974
975 if (op->flags & TX_ANNOUNCE) {
976 bcm_can_tx(op);
977 if (op->count)
978 op->count--;
979 }
980
981 if (op->flags & STARTTIMER)
982 bcm_tx_start_timer(op);
983
984 return msg_head->nframes * CFSIZ + MHSIZ;
985}
986
987/*
988 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
989 */
990static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
991 int ifindex, struct sock *sk)
992{
993 struct bcm_sock *bo = bcm_sk(sk);
994 struct bcm_op *op;
995 int do_rx_register;
996 int err = 0;
997
998 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
999 /* be robust against wrong usage ... */
1000 msg_head->flags |= RX_FILTER_ID;
1001 /* ignore trailing garbage */
1002 msg_head->nframes = 0;
1003 }
1004
1005 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1006 if (msg_head->nframes > MAX_NFRAMES + 1)
1007 return -EINVAL;
1008
1009 if ((msg_head->flags & RX_RTR_FRAME) &&
1010 ((msg_head->nframes != 1) ||
1011 (!(msg_head->can_id & CAN_RTR_FLAG))))
1012 return -EINVAL;
1013
1014 /* check the given can_id */
1015 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1016 if (op) {
1017 /* update existing BCM operation */
1018
1019 /*
1020 * Do we need more space for the can_frames than currently
1021 * allocated? -> This is a _really_ unusual use-case and
1022 * therefore (complexity / locking) it is not supported.
1023 */
1024 if (msg_head->nframes > op->nframes)
1025 return -E2BIG;
1026
1027 if (msg_head->nframes) {
1028 /* update can_frames content */
1029 err = memcpy_from_msg((u8 *)op->frames, msg,
1030 msg_head->nframes * CFSIZ);
1031 if (err < 0)
1032 return err;
1033
1034 /* clear last_frames to indicate 'nothing received' */
1035 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1036 }
1037
1038 op->nframes = msg_head->nframes;
1039
1040 /* Only an update -> do not call can_rx_register() */
1041 do_rx_register = 0;
1042
1043 } else {
1044 /* insert new BCM operation for the given can_id */
1045 op = kzalloc(OPSIZ, GFP_KERNEL);
1046 if (!op)
1047 return -ENOMEM;
1048
1049 op->can_id = msg_head->can_id;
1050 op->nframes = msg_head->nframes;
1051
1052 if (msg_head->nframes > 1) {
1053 /* create array for can_frames and copy the data */
1054 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1055 GFP_KERNEL);
1056 if (!op->frames) {
1057 kfree(op);
1058 return -ENOMEM;
1059 }
1060
1061 /* create and init array for received can_frames */
1062 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1063 GFP_KERNEL);
1064 if (!op->last_frames) {
1065 kfree(op->frames);
1066 kfree(op);
1067 return -ENOMEM;
1068 }
1069
1070 } else {
1071 op->frames = &op->sframe;
1072 op->last_frames = &op->last_sframe;
1073 }
1074
1075 if (msg_head->nframes) {
1076 err = memcpy_from_msg((u8 *)op->frames, msg,
1077 msg_head->nframes * CFSIZ);
1078 if (err < 0) {
1079 if (op->frames != &op->sframe)
1080 kfree(op->frames);
1081 if (op->last_frames != &op->last_sframe)
1082 kfree(op->last_frames);
1083 kfree(op);
1084 return err;
1085 }
1086 }
1087
1088 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1089 op->sk = sk;
1090 op->ifindex = ifindex;
1091
1092 /* ifindex for timeout events w/o previous frame reception */
1093 op->rx_ifindex = ifindex;
1094
1095 /* initialize uninitialized (kzalloc) structure */
1096 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1097 op->timer.function = bcm_rx_timeout_handler;
1098
1099 /* initialize tasklet for rx timeout notification */
1100 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1101 (unsigned long) op);
1102
1103 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1104 op->thrtimer.function = bcm_rx_thr_handler;
1105
1106 /* initialize tasklet for rx throttle handling */
1107 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1108 (unsigned long) op);
1109
1110 /* add this bcm_op to the list of the rx_ops */
1111 list_add(&op->list, &bo->rx_ops);
1112
1113 /* call can_rx_register() */
1114 do_rx_register = 1;
1115
1116 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1117
1118 /* check flags */
1119 op->flags = msg_head->flags;
1120
1121 if (op->flags & RX_RTR_FRAME) {
1122
1123 /* no timers in RTR-mode */
1124 hrtimer_cancel(&op->thrtimer);
1125 hrtimer_cancel(&op->timer);
1126
1127 /*
1128 * funny feature in RX(!)_SETUP only for RTR-mode:
1129 * copy can_id into frame BUT without RTR-flag to
1130 * prevent a full-load-loopback-test ... ;-]
1131 */
1132 if ((op->flags & TX_CP_CAN_ID) ||
1133 (op->frames[0].can_id == op->can_id))
1134 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1135
1136 } else {
1137 if (op->flags & SETTIMER) {
1138
1139 /* set timer value */
1140 op->ival1 = msg_head->ival1;
1141 op->ival2 = msg_head->ival2;
1142 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1143 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1144
1145 /* disable an active timer due to zero value? */
1146 if (!op->kt_ival1.tv64)
1147 hrtimer_cancel(&op->timer);
1148
1149 /*
1150 * In any case cancel the throttle timer, flush
1151 * potentially blocked msgs and reset throttle handling
1152 */
1153 op->kt_lastmsg = ktime_set(0, 0);
1154 hrtimer_cancel(&op->thrtimer);
1155 bcm_rx_thr_flush(op, 1);
1156 }
1157
1158 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1159 hrtimer_start(&op->timer, op->kt_ival1,
1160 HRTIMER_MODE_REL);
1161 }
1162
1163 /* now we can register for can_ids, if we added a new bcm_op */
1164 if (do_rx_register) {
1165 if (ifindex) {
1166 struct net_device *dev;
1167
1168 dev = dev_get_by_index(&init_net, ifindex);
1169 if (dev) {
1170 err = can_rx_register(dev, op->can_id,
1171 REGMASK(op->can_id),
1172 bcm_rx_handler, op,
1173 "bcm");
1174
1175 op->rx_reg_dev = dev;
1176 dev_put(dev);
1177 }
1178
1179 } else
1180 err = can_rx_register(NULL, op->can_id,
1181 REGMASK(op->can_id),
1182 bcm_rx_handler, op, "bcm");
1183 if (err) {
1184 /* this bcm rx op is broken -> remove it */
1185 list_del(&op->list);
1186 bcm_remove_op(op);
1187 return err;
1188 }
1189 }
1190
1191 return msg_head->nframes * CFSIZ + MHSIZ;
1192}
1193
1194/*
1195 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1196 */
1197static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1198{
1199 struct sk_buff *skb;
1200 struct net_device *dev;
1201 int err;
1202
1203 /* we need a real device to send frames */
1204 if (!ifindex)
1205 return -ENODEV;
1206
1207 skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), GFP_KERNEL);
1208 if (!skb)
1209 return -ENOMEM;
1210
1211 can_skb_reserve(skb);
1212
1213 err = memcpy_from_msg(skb_put(skb, CFSIZ), msg, CFSIZ);
1214 if (err < 0) {
1215 kfree_skb(skb);
1216 return err;
1217 }
1218
1219 dev = dev_get_by_index(&init_net, ifindex);
1220 if (!dev) {
1221 kfree_skb(skb);
1222 return -ENODEV;
1223 }
1224
1225 can_skb_prv(skb)->ifindex = dev->ifindex;
1226 can_skb_prv(skb)->skbcnt = 0;
1227 skb->dev = dev;
1228 can_skb_set_owner(skb, sk);
1229 err = can_send(skb, 1); /* send with loopback */
1230 dev_put(dev);
1231
1232 if (err)
1233 return err;
1234
1235 return CFSIZ + MHSIZ;
1236}
1237
1238/*
1239 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1240 */
1241static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1242{
1243 struct sock *sk = sock->sk;
1244 struct bcm_sock *bo = bcm_sk(sk);
1245 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1246 struct bcm_msg_head msg_head;
1247 int ret; /* read bytes or error codes as return value */
1248
1249 if (!bo->bound)
1250 return -ENOTCONN;
1251
1252 /* check for valid message length from userspace */
1253 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1254 return -EINVAL;
1255
1256 /* check for alternative ifindex for this bcm_op */
1257
1258 if (!ifindex && msg->msg_name) {
1259 /* no bound device as default => check msg_name */
1260 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1261
1262 if (msg->msg_namelen < sizeof(*addr))
1263 return -EINVAL;
1264
1265 if (addr->can_family != AF_CAN)
1266 return -EINVAL;
1267
1268 /* ifindex from sendto() */
1269 ifindex = addr->can_ifindex;
1270
1271 if (ifindex) {
1272 struct net_device *dev;
1273
1274 dev = dev_get_by_index(&init_net, ifindex);
1275 if (!dev)
1276 return -ENODEV;
1277
1278 if (dev->type != ARPHRD_CAN) {
1279 dev_put(dev);
1280 return -ENODEV;
1281 }
1282
1283 dev_put(dev);
1284 }
1285 }
1286
1287 /* read message head information */
1288
1289 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1290 if (ret < 0)
1291 return ret;
1292
1293 lock_sock(sk);
1294
1295 switch (msg_head.opcode) {
1296
1297 case TX_SETUP:
1298 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1299 break;
1300
1301 case RX_SETUP:
1302 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1303 break;
1304
1305 case TX_DELETE:
1306 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1307 ret = MHSIZ;
1308 else
1309 ret = -EINVAL;
1310 break;
1311
1312 case RX_DELETE:
1313 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1314 ret = MHSIZ;
1315 else
1316 ret = -EINVAL;
1317 break;
1318
1319 case TX_READ:
1320 /* reuse msg_head for the reply to TX_READ */
1321 msg_head.opcode = TX_STATUS;
1322 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1323 break;
1324
1325 case RX_READ:
1326 /* reuse msg_head for the reply to RX_READ */
1327 msg_head.opcode = RX_STATUS;
1328 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1329 break;
1330
1331 case TX_SEND:
1332 /* we need exactly one can_frame behind the msg head */
1333 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1334 ret = -EINVAL;
1335 else
1336 ret = bcm_tx_send(msg, ifindex, sk);
1337 break;
1338
1339 default:
1340 ret = -EINVAL;
1341 break;
1342 }
1343
1344 release_sock(sk);
1345
1346 return ret;
1347}
1348
1349/*
1350 * notification handler for netdevice status changes
1351 */
1352static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1353 void *ptr)
1354{
1355 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1356 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1357 struct sock *sk = &bo->sk;
1358 struct bcm_op *op;
1359 int notify_enodev = 0;
1360
1361 if (!net_eq(dev_net(dev), &init_net))
1362 return NOTIFY_DONE;
1363
1364 if (dev->type != ARPHRD_CAN)
1365 return NOTIFY_DONE;
1366
1367 switch (msg) {
1368
1369 case NETDEV_UNREGISTER:
1370 lock_sock(sk);
1371
1372 /* remove device specific receive entries */
1373 list_for_each_entry(op, &bo->rx_ops, list)
1374 if (op->rx_reg_dev == dev)
1375 bcm_rx_unreg(dev, op);
1376
1377 /* remove device reference, if this is our bound device */
1378 if (bo->bound && bo->ifindex == dev->ifindex) {
1379 bo->bound = 0;
1380 bo->ifindex = 0;
1381 notify_enodev = 1;
1382 }
1383
1384 release_sock(sk);
1385
1386 if (notify_enodev) {
1387 sk->sk_err = ENODEV;
1388 if (!sock_flag(sk, SOCK_DEAD))
1389 sk->sk_error_report(sk);
1390 }
1391 break;
1392
1393 case NETDEV_DOWN:
1394 if (bo->bound && bo->ifindex == dev->ifindex) {
1395 sk->sk_err = ENETDOWN;
1396 if (!sock_flag(sk, SOCK_DEAD))
1397 sk->sk_error_report(sk);
1398 }
1399 }
1400
1401 return NOTIFY_DONE;
1402}
1403
1404/*
1405 * initial settings for all BCM sockets to be set at socket creation time
1406 */
1407static int bcm_init(struct sock *sk)
1408{
1409 struct bcm_sock *bo = bcm_sk(sk);
1410
1411 bo->bound = 0;
1412 bo->ifindex = 0;
1413 bo->dropped_usr_msgs = 0;
1414 bo->bcm_proc_read = NULL;
1415
1416 INIT_LIST_HEAD(&bo->tx_ops);
1417 INIT_LIST_HEAD(&bo->rx_ops);
1418
1419 /* set notifier */
1420 bo->notifier.notifier_call = bcm_notifier;
1421
1422 register_netdevice_notifier(&bo->notifier);
1423
1424 return 0;
1425}
1426
1427/*
1428 * standard socket functions
1429 */
1430static int bcm_release(struct socket *sock)
1431{
1432 struct sock *sk = sock->sk;
1433 struct bcm_sock *bo;
1434 struct bcm_op *op, *next;
1435
1436 if (sk == NULL)
1437 return 0;
1438
1439 bo = bcm_sk(sk);
1440
1441 /* remove bcm_ops, timer, rx_unregister(), etc. */
1442
1443 unregister_netdevice_notifier(&bo->notifier);
1444
1445 lock_sock(sk);
1446
1447 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1448 bcm_remove_op(op);
1449
1450 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1451 /*
1452 * Don't care if we're bound or not (due to netdev problems)
1453 * can_rx_unregister() is always a save thing to do here.
1454 */
1455 if (op->ifindex) {
1456 /*
1457 * Only remove subscriptions that had not
1458 * been removed due to NETDEV_UNREGISTER
1459 * in bcm_notifier()
1460 */
1461 if (op->rx_reg_dev) {
1462 struct net_device *dev;
1463
1464 dev = dev_get_by_index(&init_net, op->ifindex);
1465 if (dev) {
1466 bcm_rx_unreg(dev, op);
1467 dev_put(dev);
1468 }
1469 }
1470 } else
1471 can_rx_unregister(NULL, op->can_id,
1472 REGMASK(op->can_id),
1473 bcm_rx_handler, op);
1474
1475 bcm_remove_op(op);
1476 }
1477
1478 /* remove procfs entry */
1479 if (proc_dir && bo->bcm_proc_read)
1480 remove_proc_entry(bo->procname, proc_dir);
1481
1482 /* remove device reference */
1483 if (bo->bound) {
1484 bo->bound = 0;
1485 bo->ifindex = 0;
1486 }
1487
1488 sock_orphan(sk);
1489 sock->sk = NULL;
1490
1491 release_sock(sk);
1492 sock_put(sk);
1493
1494 return 0;
1495}
1496
1497static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1498 int flags)
1499{
1500 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1501 struct sock *sk = sock->sk;
1502 struct bcm_sock *bo = bcm_sk(sk);
1503
1504 if (len < sizeof(*addr))
1505 return -EINVAL;
1506
1507 if (bo->bound)
1508 return -EISCONN;
1509
1510 /* bind a device to this socket */
1511 if (addr->can_ifindex) {
1512 struct net_device *dev;
1513
1514 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1515 if (!dev)
1516 return -ENODEV;
1517
1518 if (dev->type != ARPHRD_CAN) {
1519 dev_put(dev);
1520 return -ENODEV;
1521 }
1522
1523 bo->ifindex = dev->ifindex;
1524 dev_put(dev);
1525
1526 } else {
1527 /* no interface reference for ifindex = 0 ('any' CAN device) */
1528 bo->ifindex = 0;
1529 }
1530
1531 bo->bound = 1;
1532
1533 if (proc_dir) {
1534 /* unique socket address as filename */
1535 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1536 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1537 proc_dir,
1538 &bcm_proc_fops, sk);
1539 }
1540
1541 return 0;
1542}
1543
1544static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1545 int flags)
1546{
1547 struct sock *sk = sock->sk;
1548 struct sk_buff *skb;
1549 int error = 0;
1550 int noblock;
1551 int err;
1552
1553 noblock = flags & MSG_DONTWAIT;
1554 flags &= ~MSG_DONTWAIT;
1555 skb = skb_recv_datagram(sk, flags, noblock, &error);
1556 if (!skb)
1557 return error;
1558
1559 if (skb->len < size)
1560 size = skb->len;
1561
1562 err = memcpy_to_msg(msg, skb->data, size);
1563 if (err < 0) {
1564 skb_free_datagram(sk, skb);
1565 return err;
1566 }
1567
1568 sock_recv_ts_and_drops(msg, sk, skb);
1569
1570 if (msg->msg_name) {
1571 __sockaddr_check_size(sizeof(struct sockaddr_can));
1572 msg->msg_namelen = sizeof(struct sockaddr_can);
1573 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1574 }
1575
1576 skb_free_datagram(sk, skb);
1577
1578 return size;
1579}
1580
1581static const struct proto_ops bcm_ops = {
1582 .family = PF_CAN,
1583 .release = bcm_release,
1584 .bind = sock_no_bind,
1585 .connect = bcm_connect,
1586 .socketpair = sock_no_socketpair,
1587 .accept = sock_no_accept,
1588 .getname = sock_no_getname,
1589 .poll = datagram_poll,
1590 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1591 .listen = sock_no_listen,
1592 .shutdown = sock_no_shutdown,
1593 .setsockopt = sock_no_setsockopt,
1594 .getsockopt = sock_no_getsockopt,
1595 .sendmsg = bcm_sendmsg,
1596 .recvmsg = bcm_recvmsg,
1597 .mmap = sock_no_mmap,
1598 .sendpage = sock_no_sendpage,
1599};
1600
1601static struct proto bcm_proto __read_mostly = {
1602 .name = "CAN_BCM",
1603 .owner = THIS_MODULE,
1604 .obj_size = sizeof(struct bcm_sock),
1605 .init = bcm_init,
1606};
1607
1608static const struct can_proto bcm_can_proto = {
1609 .type = SOCK_DGRAM,
1610 .protocol = CAN_BCM,
1611 .ops = &bcm_ops,
1612 .prot = &bcm_proto,
1613};
1614
1615static int __init bcm_module_init(void)
1616{
1617 int err;
1618
1619 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1620
1621 err = can_proto_register(&bcm_can_proto);
1622 if (err < 0) {
1623 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1624 return err;
1625 }
1626
1627 /* create /proc/net/can-bcm directory */
1628 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1629 return 0;
1630}
1631
1632static void __exit bcm_module_exit(void)
1633{
1634 can_proto_unregister(&bcm_can_proto);
1635
1636 if (proc_dir)
1637 remove_proc_entry("can-bcm", init_net.proc_net);
1638}
1639
1640module_init(bcm_module_init);
1641module_exit(bcm_module_exit);