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1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2/*
3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 *
5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of Volkswagen nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * Alternatively, provided that this notice is retained in full, this
21 * software may be distributed under the terms of the GNU General
22 * Public License ("GPL") version 2, in which case the provisions of the
23 * GPL apply INSTEAD OF those given above.
24 *
25 * The provided data structures and external interfaces from this code
26 * are not restricted to be used by modules with a GPL compatible license.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
39 * DAMAGE.
40 *
41 */
42
43#include <linux/module.h>
44#include <linux/init.h>
45#include <linux/interrupt.h>
46#include <linux/hrtimer.h>
47#include <linux/list.h>
48#include <linux/proc_fs.h>
49#include <linux/seq_file.h>
50#include <linux/uio.h>
51#include <linux/net.h>
52#include <linux/netdevice.h>
53#include <linux/socket.h>
54#include <linux/if_arp.h>
55#include <linux/skbuff.h>
56#include <linux/can.h>
57#include <linux/can/core.h>
58#include <linux/can/skb.h>
59#include <linux/can/bcm.h>
60#include <linux/slab.h>
61#include <net/sock.h>
62#include <net/net_namespace.h>
63
64/*
65 * To send multiple CAN frame content within TX_SETUP or to filter
66 * CAN messages with multiplex index within RX_SETUP, the number of
67 * different filters is limited to 256 due to the one byte index value.
68 */
69#define MAX_NFRAMES 256
70
71/* limit timers to 400 days for sending/timeouts */
72#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
73
74/* use of last_frames[index].flags */
75#define RX_LOCAL 0x10 /* frame was created on the local host */
76#define RX_OWN 0x20 /* frame was sent via the socket it was received on */
77#define RX_RECV 0x40 /* received data for this element */
78#define RX_THR 0x80 /* element not been sent due to throttle feature */
79#define BCM_CAN_FLAGS_MASK 0x0F /* to clean private flags after usage */
80
81/* get best masking value for can_rx_register() for a given single can_id */
82#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
83 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
84 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
85
86MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
87MODULE_LICENSE("Dual BSD/GPL");
88MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
89MODULE_ALIAS("can-proto-2");
90
91#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
92
93/*
94 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
95 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
96 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
97 */
98static inline u64 get_u64(const struct canfd_frame *cp, int offset)
99{
100 return *(u64 *)(cp->data + offset);
101}
102
103struct bcm_op {
104 struct list_head list;
105 struct rcu_head rcu;
106 int ifindex;
107 canid_t can_id;
108 u32 flags;
109 unsigned long frames_abs, frames_filtered;
110 struct bcm_timeval ival1, ival2;
111 struct hrtimer timer, thrtimer;
112 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
113 int rx_ifindex;
114 int cfsiz;
115 u32 count;
116 u32 nframes;
117 u32 currframe;
118 /* void pointers to arrays of struct can[fd]_frame */
119 void *frames;
120 void *last_frames;
121 struct canfd_frame sframe;
122 struct canfd_frame last_sframe;
123 struct sock *sk;
124 struct net_device *rx_reg_dev;
125};
126
127struct bcm_sock {
128 struct sock sk;
129 int bound;
130 int ifindex;
131 struct list_head notifier;
132 struct list_head rx_ops;
133 struct list_head tx_ops;
134 unsigned long dropped_usr_msgs;
135 struct proc_dir_entry *bcm_proc_read;
136 char procname [32]; /* inode number in decimal with \0 */
137};
138
139static LIST_HEAD(bcm_notifier_list);
140static DEFINE_SPINLOCK(bcm_notifier_lock);
141static struct bcm_sock *bcm_busy_notifier;
142
143/* Return pointer to store the extra msg flags for bcm_recvmsg().
144 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
145 * in skb->cb.
146 */
147static inline unsigned int *bcm_flags(struct sk_buff *skb)
148{
149 /* return pointer after struct sockaddr_can */
150 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
151}
152
153static inline struct bcm_sock *bcm_sk(const struct sock *sk)
154{
155 return (struct bcm_sock *)sk;
156}
157
158static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
159{
160 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
161}
162
163/* check limitations for timeval provided by user */
164static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
165{
166 if ((msg_head->ival1.tv_sec < 0) ||
167 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
168 (msg_head->ival1.tv_usec < 0) ||
169 (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
170 (msg_head->ival2.tv_sec < 0) ||
171 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
172 (msg_head->ival2.tv_usec < 0) ||
173 (msg_head->ival2.tv_usec >= USEC_PER_SEC))
174 return true;
175
176 return false;
177}
178
179#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
180#define OPSIZ sizeof(struct bcm_op)
181#define MHSIZ sizeof(struct bcm_msg_head)
182
183/*
184 * procfs functions
185 */
186#if IS_ENABLED(CONFIG_PROC_FS)
187static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
188{
189 struct net_device *dev;
190
191 if (!ifindex)
192 return "any";
193
194 rcu_read_lock();
195 dev = dev_get_by_index_rcu(net, ifindex);
196 if (dev)
197 strcpy(result, dev->name);
198 else
199 strcpy(result, "???");
200 rcu_read_unlock();
201
202 return result;
203}
204
205static int bcm_proc_show(struct seq_file *m, void *v)
206{
207 char ifname[IFNAMSIZ];
208 struct net *net = m->private;
209 struct sock *sk = (struct sock *)pde_data(m->file->f_inode);
210 struct bcm_sock *bo = bcm_sk(sk);
211 struct bcm_op *op;
212
213 seq_printf(m, ">>> socket %pK", sk->sk_socket);
214 seq_printf(m, " / sk %pK", sk);
215 seq_printf(m, " / bo %pK", bo);
216 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
217 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
218 seq_printf(m, " <<<\n");
219
220 list_for_each_entry(op, &bo->rx_ops, list) {
221
222 unsigned long reduction;
223
224 /* print only active entries & prevent division by zero */
225 if (!op->frames_abs)
226 continue;
227
228 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
229 bcm_proc_getifname(net, ifname, op->ifindex));
230
231 if (op->flags & CAN_FD_FRAME)
232 seq_printf(m, "(%u)", op->nframes);
233 else
234 seq_printf(m, "[%u]", op->nframes);
235
236 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
237
238 if (op->kt_ival1)
239 seq_printf(m, "timeo=%lld ",
240 (long long)ktime_to_us(op->kt_ival1));
241
242 if (op->kt_ival2)
243 seq_printf(m, "thr=%lld ",
244 (long long)ktime_to_us(op->kt_ival2));
245
246 seq_printf(m, "# recv %ld (%ld) => reduction: ",
247 op->frames_filtered, op->frames_abs);
248
249 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
250
251 seq_printf(m, "%s%ld%%\n",
252 (reduction == 100) ? "near " : "", reduction);
253 }
254
255 list_for_each_entry(op, &bo->tx_ops, list) {
256
257 seq_printf(m, "tx_op: %03X %s ", op->can_id,
258 bcm_proc_getifname(net, ifname, op->ifindex));
259
260 if (op->flags & CAN_FD_FRAME)
261 seq_printf(m, "(%u) ", op->nframes);
262 else
263 seq_printf(m, "[%u] ", op->nframes);
264
265 if (op->kt_ival1)
266 seq_printf(m, "t1=%lld ",
267 (long long)ktime_to_us(op->kt_ival1));
268
269 if (op->kt_ival2)
270 seq_printf(m, "t2=%lld ",
271 (long long)ktime_to_us(op->kt_ival2));
272
273 seq_printf(m, "# sent %ld\n", op->frames_abs);
274 }
275 seq_putc(m, '\n');
276 return 0;
277}
278#endif /* CONFIG_PROC_FS */
279
280/*
281 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
282 * of the given bcm tx op
283 */
284static void bcm_can_tx(struct bcm_op *op)
285{
286 struct sk_buff *skb;
287 struct net_device *dev;
288 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
289 int err;
290
291 /* no target device? => exit */
292 if (!op->ifindex)
293 return;
294
295 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
296 if (!dev) {
297 /* RFC: should this bcm_op remove itself here? */
298 return;
299 }
300
301 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
302 if (!skb)
303 goto out;
304
305 can_skb_reserve(skb);
306 can_skb_prv(skb)->ifindex = dev->ifindex;
307 can_skb_prv(skb)->skbcnt = 0;
308
309 skb_put_data(skb, cf, op->cfsiz);
310
311 /* send with loopback */
312 skb->dev = dev;
313 can_skb_set_owner(skb, op->sk);
314 err = can_send(skb, 1);
315 if (!err)
316 op->frames_abs++;
317
318 op->currframe++;
319
320 /* reached last frame? */
321 if (op->currframe >= op->nframes)
322 op->currframe = 0;
323out:
324 dev_put(dev);
325}
326
327/*
328 * bcm_send_to_user - send a BCM message to the userspace
329 * (consisting of bcm_msg_head + x CAN frames)
330 */
331static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
332 struct canfd_frame *frames, int has_timestamp)
333{
334 struct sk_buff *skb;
335 struct canfd_frame *firstframe;
336 struct sockaddr_can *addr;
337 struct sock *sk = op->sk;
338 unsigned int datalen = head->nframes * op->cfsiz;
339 int err;
340 unsigned int *pflags;
341
342 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
343 if (!skb)
344 return;
345
346 skb_put_data(skb, head, sizeof(*head));
347
348 /* ensure space for sockaddr_can and msg flags */
349 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
350 sizeof(unsigned int));
351
352 /* initialize msg flags */
353 pflags = bcm_flags(skb);
354 *pflags = 0;
355
356 if (head->nframes) {
357 /* CAN frames starting here */
358 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
359
360 skb_put_data(skb, frames, datalen);
361
362 /*
363 * the BCM uses the flags-element of the canfd_frame
364 * structure for internal purposes. This is only
365 * relevant for updates that are generated by the
366 * BCM, where nframes is 1
367 */
368 if (head->nframes == 1) {
369 if (firstframe->flags & RX_LOCAL)
370 *pflags |= MSG_DONTROUTE;
371 if (firstframe->flags & RX_OWN)
372 *pflags |= MSG_CONFIRM;
373
374 firstframe->flags &= BCM_CAN_FLAGS_MASK;
375 }
376 }
377
378 if (has_timestamp) {
379 /* restore rx timestamp */
380 skb->tstamp = op->rx_stamp;
381 }
382
383 /*
384 * Put the datagram to the queue so that bcm_recvmsg() can
385 * get it from there. We need to pass the interface index to
386 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
387 * containing the interface index.
388 */
389
390 addr = (struct sockaddr_can *)skb->cb;
391 memset(addr, 0, sizeof(*addr));
392 addr->can_family = AF_CAN;
393 addr->can_ifindex = op->rx_ifindex;
394
395 err = sock_queue_rcv_skb(sk, skb);
396 if (err < 0) {
397 struct bcm_sock *bo = bcm_sk(sk);
398
399 kfree_skb(skb);
400 /* don't care about overflows in this statistic */
401 bo->dropped_usr_msgs++;
402 }
403}
404
405static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
406{
407 ktime_t ival;
408
409 if (op->kt_ival1 && op->count)
410 ival = op->kt_ival1;
411 else if (op->kt_ival2)
412 ival = op->kt_ival2;
413 else
414 return false;
415
416 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
417 return true;
418}
419
420static void bcm_tx_start_timer(struct bcm_op *op)
421{
422 if (bcm_tx_set_expiry(op, &op->timer))
423 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
424}
425
426/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
427static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
428{
429 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
430 struct bcm_msg_head msg_head;
431
432 if (op->kt_ival1 && (op->count > 0)) {
433 op->count--;
434 if (!op->count && (op->flags & TX_COUNTEVT)) {
435
436 /* create notification to user */
437 memset(&msg_head, 0, sizeof(msg_head));
438 msg_head.opcode = TX_EXPIRED;
439 msg_head.flags = op->flags;
440 msg_head.count = op->count;
441 msg_head.ival1 = op->ival1;
442 msg_head.ival2 = op->ival2;
443 msg_head.can_id = op->can_id;
444 msg_head.nframes = 0;
445
446 bcm_send_to_user(op, &msg_head, NULL, 0);
447 }
448 bcm_can_tx(op);
449
450 } else if (op->kt_ival2) {
451 bcm_can_tx(op);
452 }
453
454 return bcm_tx_set_expiry(op, &op->timer) ?
455 HRTIMER_RESTART : HRTIMER_NORESTART;
456}
457
458/*
459 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
460 */
461static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
462{
463 struct bcm_msg_head head;
464
465 /* update statistics */
466 op->frames_filtered++;
467
468 /* prevent statistics overflow */
469 if (op->frames_filtered > ULONG_MAX/100)
470 op->frames_filtered = op->frames_abs = 0;
471
472 /* this element is not throttled anymore */
473 data->flags &= ~RX_THR;
474
475 memset(&head, 0, sizeof(head));
476 head.opcode = RX_CHANGED;
477 head.flags = op->flags;
478 head.count = op->count;
479 head.ival1 = op->ival1;
480 head.ival2 = op->ival2;
481 head.can_id = op->can_id;
482 head.nframes = 1;
483
484 bcm_send_to_user(op, &head, data, 1);
485}
486
487/*
488 * bcm_rx_update_and_send - process a detected relevant receive content change
489 * 1. update the last received data
490 * 2. send a notification to the user (if possible)
491 */
492static void bcm_rx_update_and_send(struct bcm_op *op,
493 struct canfd_frame *lastdata,
494 const struct canfd_frame *rxdata,
495 unsigned char traffic_flags)
496{
497 memcpy(lastdata, rxdata, op->cfsiz);
498
499 /* mark as used and throttled by default */
500 lastdata->flags |= (RX_RECV|RX_THR);
501
502 /* add own/local/remote traffic flags */
503 lastdata->flags |= traffic_flags;
504
505 /* throttling mode inactive ? */
506 if (!op->kt_ival2) {
507 /* send RX_CHANGED to the user immediately */
508 bcm_rx_changed(op, lastdata);
509 return;
510 }
511
512 /* with active throttling timer we are just done here */
513 if (hrtimer_active(&op->thrtimer))
514 return;
515
516 /* first reception with enabled throttling mode */
517 if (!op->kt_lastmsg)
518 goto rx_changed_settime;
519
520 /* got a second frame inside a potential throttle period? */
521 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
522 ktime_to_us(op->kt_ival2)) {
523 /* do not send the saved data - only start throttle timer */
524 hrtimer_start(&op->thrtimer,
525 ktime_add(op->kt_lastmsg, op->kt_ival2),
526 HRTIMER_MODE_ABS_SOFT);
527 return;
528 }
529
530 /* the gap was that big, that throttling was not needed here */
531rx_changed_settime:
532 bcm_rx_changed(op, lastdata);
533 op->kt_lastmsg = ktime_get();
534}
535
536/*
537 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
538 * received data stored in op->last_frames[]
539 */
540static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
541 const struct canfd_frame *rxdata,
542 unsigned char traffic_flags)
543{
544 struct canfd_frame *cf = op->frames + op->cfsiz * index;
545 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
546 int i;
547
548 /*
549 * no one uses the MSBs of flags for comparison,
550 * so we use it here to detect the first time of reception
551 */
552
553 if (!(lcf->flags & RX_RECV)) {
554 /* received data for the first time => send update to user */
555 bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags);
556 return;
557 }
558
559 /* do a real check in CAN frame data section */
560 for (i = 0; i < rxdata->len; i += 8) {
561 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
562 (get_u64(cf, i) & get_u64(lcf, i))) {
563 bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags);
564 return;
565 }
566 }
567
568 if (op->flags & RX_CHECK_DLC) {
569 /* do a real check in CAN frame length */
570 if (rxdata->len != lcf->len) {
571 bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags);
572 return;
573 }
574 }
575}
576
577/*
578 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
579 */
580static void bcm_rx_starttimer(struct bcm_op *op)
581{
582 if (op->flags & RX_NO_AUTOTIMER)
583 return;
584
585 if (op->kt_ival1)
586 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
587}
588
589/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
590static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
591{
592 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
593 struct bcm_msg_head msg_head;
594
595 /* if user wants to be informed, when cyclic CAN-Messages come back */
596 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
597 /* clear received CAN frames to indicate 'nothing received' */
598 memset(op->last_frames, 0, op->nframes * op->cfsiz);
599 }
600
601 /* create notification to user */
602 memset(&msg_head, 0, sizeof(msg_head));
603 msg_head.opcode = RX_TIMEOUT;
604 msg_head.flags = op->flags;
605 msg_head.count = op->count;
606 msg_head.ival1 = op->ival1;
607 msg_head.ival2 = op->ival2;
608 msg_head.can_id = op->can_id;
609 msg_head.nframes = 0;
610
611 bcm_send_to_user(op, &msg_head, NULL, 0);
612
613 return HRTIMER_NORESTART;
614}
615
616/*
617 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
618 */
619static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
620{
621 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
622
623 if ((op->last_frames) && (lcf->flags & RX_THR)) {
624 bcm_rx_changed(op, lcf);
625 return 1;
626 }
627 return 0;
628}
629
630/*
631 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
632 */
633static int bcm_rx_thr_flush(struct bcm_op *op)
634{
635 int updated = 0;
636
637 if (op->nframes > 1) {
638 unsigned int i;
639
640 /* for MUX filter we start at index 1 */
641 for (i = 1; i < op->nframes; i++)
642 updated += bcm_rx_do_flush(op, i);
643
644 } else {
645 /* for RX_FILTER_ID and simple filter */
646 updated += bcm_rx_do_flush(op, 0);
647 }
648
649 return updated;
650}
651
652/*
653 * bcm_rx_thr_handler - the time for blocked content updates is over now:
654 * Check for throttled data and send it to the userspace
655 */
656static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
657{
658 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
659
660 if (bcm_rx_thr_flush(op)) {
661 hrtimer_forward_now(hrtimer, op->kt_ival2);
662 return HRTIMER_RESTART;
663 } else {
664 /* rearm throttle handling */
665 op->kt_lastmsg = 0;
666 return HRTIMER_NORESTART;
667 }
668}
669
670/*
671 * bcm_rx_handler - handle a CAN frame reception
672 */
673static void bcm_rx_handler(struct sk_buff *skb, void *data)
674{
675 struct bcm_op *op = (struct bcm_op *)data;
676 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
677 unsigned int i;
678 unsigned char traffic_flags;
679
680 if (op->can_id != rxframe->can_id)
681 return;
682
683 /* make sure to handle the correct frame type (CAN / CAN FD) */
684 if (op->flags & CAN_FD_FRAME) {
685 if (!can_is_canfd_skb(skb))
686 return;
687 } else {
688 if (!can_is_can_skb(skb))
689 return;
690 }
691
692 /* disable timeout */
693 hrtimer_cancel(&op->timer);
694
695 /* save rx timestamp */
696 op->rx_stamp = skb->tstamp;
697 /* save originator for recvfrom() */
698 op->rx_ifindex = skb->dev->ifindex;
699 /* update statistics */
700 op->frames_abs++;
701
702 if (op->flags & RX_RTR_FRAME) {
703 /* send reply for RTR-request (placed in op->frames[0]) */
704 bcm_can_tx(op);
705 return;
706 }
707
708 /* compute flags to distinguish between own/local/remote CAN traffic */
709 traffic_flags = 0;
710 if (skb->sk) {
711 traffic_flags |= RX_LOCAL;
712 if (skb->sk == op->sk)
713 traffic_flags |= RX_OWN;
714 }
715
716 if (op->flags & RX_FILTER_ID) {
717 /* the easiest case */
718 bcm_rx_update_and_send(op, op->last_frames, rxframe,
719 traffic_flags);
720 goto rx_starttimer;
721 }
722
723 if (op->nframes == 1) {
724 /* simple compare with index 0 */
725 bcm_rx_cmp_to_index(op, 0, rxframe, traffic_flags);
726 goto rx_starttimer;
727 }
728
729 if (op->nframes > 1) {
730 /*
731 * multiplex compare
732 *
733 * find the first multiplex mask that fits.
734 * Remark: The MUX-mask is stored in index 0 - but only the
735 * first 64 bits of the frame data[] are relevant (CAN FD)
736 */
737
738 for (i = 1; i < op->nframes; i++) {
739 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
740 (get_u64(op->frames, 0) &
741 get_u64(op->frames + op->cfsiz * i, 0))) {
742 bcm_rx_cmp_to_index(op, i, rxframe,
743 traffic_flags);
744 break;
745 }
746 }
747 }
748
749rx_starttimer:
750 bcm_rx_starttimer(op);
751}
752
753/*
754 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
755 */
756static struct bcm_op *bcm_find_op(struct list_head *ops,
757 struct bcm_msg_head *mh, int ifindex)
758{
759 struct bcm_op *op;
760
761 list_for_each_entry(op, ops, list) {
762 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
763 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
764 return op;
765 }
766
767 return NULL;
768}
769
770static void bcm_free_op_rcu(struct rcu_head *rcu_head)
771{
772 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
773
774 if ((op->frames) && (op->frames != &op->sframe))
775 kfree(op->frames);
776
777 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
778 kfree(op->last_frames);
779
780 kfree(op);
781}
782
783static void bcm_remove_op(struct bcm_op *op)
784{
785 hrtimer_cancel(&op->timer);
786 hrtimer_cancel(&op->thrtimer);
787
788 call_rcu(&op->rcu, bcm_free_op_rcu);
789}
790
791static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
792{
793 if (op->rx_reg_dev == dev) {
794 can_rx_unregister(dev_net(dev), dev, op->can_id,
795 REGMASK(op->can_id), bcm_rx_handler, op);
796
797 /* mark as removed subscription */
798 op->rx_reg_dev = NULL;
799 } else
800 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
801 "mismatch %p %p\n", op->rx_reg_dev, dev);
802}
803
804/*
805 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
806 */
807static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
808 int ifindex)
809{
810 struct bcm_op *op, *n;
811
812 list_for_each_entry_safe(op, n, ops, list) {
813 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
814 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
815
816 /* disable automatic timer on frame reception */
817 op->flags |= RX_NO_AUTOTIMER;
818
819 /*
820 * Don't care if we're bound or not (due to netdev
821 * problems) can_rx_unregister() is always a save
822 * thing to do here.
823 */
824 if (op->ifindex) {
825 /*
826 * Only remove subscriptions that had not
827 * been removed due to NETDEV_UNREGISTER
828 * in bcm_notifier()
829 */
830 if (op->rx_reg_dev) {
831 struct net_device *dev;
832
833 dev = dev_get_by_index(sock_net(op->sk),
834 op->ifindex);
835 if (dev) {
836 bcm_rx_unreg(dev, op);
837 dev_put(dev);
838 }
839 }
840 } else
841 can_rx_unregister(sock_net(op->sk), NULL,
842 op->can_id,
843 REGMASK(op->can_id),
844 bcm_rx_handler, op);
845
846 list_del(&op->list);
847 bcm_remove_op(op);
848 return 1; /* done */
849 }
850 }
851
852 return 0; /* not found */
853}
854
855/*
856 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
857 */
858static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
859 int ifindex)
860{
861 struct bcm_op *op, *n;
862
863 list_for_each_entry_safe(op, n, ops, list) {
864 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
865 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
866 list_del(&op->list);
867 bcm_remove_op(op);
868 return 1; /* done */
869 }
870 }
871
872 return 0; /* not found */
873}
874
875/*
876 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
877 */
878static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
879 int ifindex)
880{
881 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
882
883 if (!op)
884 return -EINVAL;
885
886 /* put current values into msg_head */
887 msg_head->flags = op->flags;
888 msg_head->count = op->count;
889 msg_head->ival1 = op->ival1;
890 msg_head->ival2 = op->ival2;
891 msg_head->nframes = op->nframes;
892
893 bcm_send_to_user(op, msg_head, op->frames, 0);
894
895 return MHSIZ;
896}
897
898/*
899 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
900 */
901static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
902 int ifindex, struct sock *sk)
903{
904 struct bcm_sock *bo = bcm_sk(sk);
905 struct bcm_op *op;
906 struct canfd_frame *cf;
907 unsigned int i;
908 int err;
909
910 /* we need a real device to send frames */
911 if (!ifindex)
912 return -ENODEV;
913
914 /* check nframes boundaries - we need at least one CAN frame */
915 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
916 return -EINVAL;
917
918 /* check timeval limitations */
919 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
920 return -EINVAL;
921
922 /* check the given can_id */
923 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
924 if (op) {
925 /* update existing BCM operation */
926
927 /*
928 * Do we need more space for the CAN frames than currently
929 * allocated? -> This is a _really_ unusual use-case and
930 * therefore (complexity / locking) it is not supported.
931 */
932 if (msg_head->nframes > op->nframes)
933 return -E2BIG;
934
935 /* update CAN frames content */
936 for (i = 0; i < msg_head->nframes; i++) {
937
938 cf = op->frames + op->cfsiz * i;
939 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
940
941 if (op->flags & CAN_FD_FRAME) {
942 if (cf->len > 64)
943 err = -EINVAL;
944 } else {
945 if (cf->len > 8)
946 err = -EINVAL;
947 }
948
949 if (err < 0)
950 return err;
951
952 if (msg_head->flags & TX_CP_CAN_ID) {
953 /* copy can_id into frame */
954 cf->can_id = msg_head->can_id;
955 }
956 }
957 op->flags = msg_head->flags;
958
959 } else {
960 /* insert new BCM operation for the given can_id */
961
962 op = kzalloc(OPSIZ, GFP_KERNEL);
963 if (!op)
964 return -ENOMEM;
965
966 op->can_id = msg_head->can_id;
967 op->cfsiz = CFSIZ(msg_head->flags);
968 op->flags = msg_head->flags;
969
970 /* create array for CAN frames and copy the data */
971 if (msg_head->nframes > 1) {
972 op->frames = kmalloc_array(msg_head->nframes,
973 op->cfsiz,
974 GFP_KERNEL);
975 if (!op->frames) {
976 kfree(op);
977 return -ENOMEM;
978 }
979 } else
980 op->frames = &op->sframe;
981
982 for (i = 0; i < msg_head->nframes; i++) {
983
984 cf = op->frames + op->cfsiz * i;
985 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
986 if (err < 0)
987 goto free_op;
988
989 if (op->flags & CAN_FD_FRAME) {
990 if (cf->len > 64)
991 err = -EINVAL;
992 } else {
993 if (cf->len > 8)
994 err = -EINVAL;
995 }
996
997 if (err < 0)
998 goto free_op;
999
1000 if (msg_head->flags & TX_CP_CAN_ID) {
1001 /* copy can_id into frame */
1002 cf->can_id = msg_head->can_id;
1003 }
1004 }
1005
1006 /* tx_ops never compare with previous received messages */
1007 op->last_frames = NULL;
1008
1009 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1010 op->sk = sk;
1011 op->ifindex = ifindex;
1012
1013 /* initialize uninitialized (kzalloc) structure */
1014 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1015 HRTIMER_MODE_REL_SOFT);
1016 op->timer.function = bcm_tx_timeout_handler;
1017
1018 /* currently unused in tx_ops */
1019 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1020 HRTIMER_MODE_REL_SOFT);
1021
1022 /* add this bcm_op to the list of the tx_ops */
1023 list_add(&op->list, &bo->tx_ops);
1024
1025 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
1026
1027 if (op->nframes != msg_head->nframes) {
1028 op->nframes = msg_head->nframes;
1029 /* start multiple frame transmission with index 0 */
1030 op->currframe = 0;
1031 }
1032
1033 /* check flags */
1034
1035 if (op->flags & TX_RESET_MULTI_IDX) {
1036 /* start multiple frame transmission with index 0 */
1037 op->currframe = 0;
1038 }
1039
1040 if (op->flags & SETTIMER) {
1041 /* set timer values */
1042 op->count = msg_head->count;
1043 op->ival1 = msg_head->ival1;
1044 op->ival2 = msg_head->ival2;
1045 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1046 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1047
1048 /* disable an active timer due to zero values? */
1049 if (!op->kt_ival1 && !op->kt_ival2)
1050 hrtimer_cancel(&op->timer);
1051 }
1052
1053 if (op->flags & STARTTIMER) {
1054 hrtimer_cancel(&op->timer);
1055 /* spec: send CAN frame when starting timer */
1056 op->flags |= TX_ANNOUNCE;
1057 }
1058
1059 if (op->flags & TX_ANNOUNCE) {
1060 bcm_can_tx(op);
1061 if (op->count)
1062 op->count--;
1063 }
1064
1065 if (op->flags & STARTTIMER)
1066 bcm_tx_start_timer(op);
1067
1068 return msg_head->nframes * op->cfsiz + MHSIZ;
1069
1070free_op:
1071 if (op->frames != &op->sframe)
1072 kfree(op->frames);
1073 kfree(op);
1074 return err;
1075}
1076
1077/*
1078 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1079 */
1080static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1081 int ifindex, struct sock *sk)
1082{
1083 struct bcm_sock *bo = bcm_sk(sk);
1084 struct bcm_op *op;
1085 int do_rx_register;
1086 int err = 0;
1087
1088 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1089 /* be robust against wrong usage ... */
1090 msg_head->flags |= RX_FILTER_ID;
1091 /* ignore trailing garbage */
1092 msg_head->nframes = 0;
1093 }
1094
1095 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1096 if (msg_head->nframes > MAX_NFRAMES + 1)
1097 return -EINVAL;
1098
1099 if ((msg_head->flags & RX_RTR_FRAME) &&
1100 ((msg_head->nframes != 1) ||
1101 (!(msg_head->can_id & CAN_RTR_FLAG))))
1102 return -EINVAL;
1103
1104 /* check timeval limitations */
1105 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1106 return -EINVAL;
1107
1108 /* check the given can_id */
1109 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1110 if (op) {
1111 /* update existing BCM operation */
1112
1113 /*
1114 * Do we need more space for the CAN frames than currently
1115 * allocated? -> This is a _really_ unusual use-case and
1116 * therefore (complexity / locking) it is not supported.
1117 */
1118 if (msg_head->nframes > op->nframes)
1119 return -E2BIG;
1120
1121 if (msg_head->nframes) {
1122 /* update CAN frames content */
1123 err = memcpy_from_msg(op->frames, msg,
1124 msg_head->nframes * op->cfsiz);
1125 if (err < 0)
1126 return err;
1127
1128 /* clear last_frames to indicate 'nothing received' */
1129 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1130 }
1131
1132 op->nframes = msg_head->nframes;
1133 op->flags = msg_head->flags;
1134
1135 /* Only an update -> do not call can_rx_register() */
1136 do_rx_register = 0;
1137
1138 } else {
1139 /* insert new BCM operation for the given can_id */
1140 op = kzalloc(OPSIZ, GFP_KERNEL);
1141 if (!op)
1142 return -ENOMEM;
1143
1144 op->can_id = msg_head->can_id;
1145 op->nframes = msg_head->nframes;
1146 op->cfsiz = CFSIZ(msg_head->flags);
1147 op->flags = msg_head->flags;
1148
1149 if (msg_head->nframes > 1) {
1150 /* create array for CAN frames and copy the data */
1151 op->frames = kmalloc_array(msg_head->nframes,
1152 op->cfsiz,
1153 GFP_KERNEL);
1154 if (!op->frames) {
1155 kfree(op);
1156 return -ENOMEM;
1157 }
1158
1159 /* create and init array for received CAN frames */
1160 op->last_frames = kcalloc(msg_head->nframes,
1161 op->cfsiz,
1162 GFP_KERNEL);
1163 if (!op->last_frames) {
1164 kfree(op->frames);
1165 kfree(op);
1166 return -ENOMEM;
1167 }
1168
1169 } else {
1170 op->frames = &op->sframe;
1171 op->last_frames = &op->last_sframe;
1172 }
1173
1174 if (msg_head->nframes) {
1175 err = memcpy_from_msg(op->frames, msg,
1176 msg_head->nframes * op->cfsiz);
1177 if (err < 0) {
1178 if (op->frames != &op->sframe)
1179 kfree(op->frames);
1180 if (op->last_frames != &op->last_sframe)
1181 kfree(op->last_frames);
1182 kfree(op);
1183 return err;
1184 }
1185 }
1186
1187 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1188 op->sk = sk;
1189 op->ifindex = ifindex;
1190
1191 /* ifindex for timeout events w/o previous frame reception */
1192 op->rx_ifindex = ifindex;
1193
1194 /* initialize uninitialized (kzalloc) structure */
1195 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1196 HRTIMER_MODE_REL_SOFT);
1197 op->timer.function = bcm_rx_timeout_handler;
1198
1199 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1200 HRTIMER_MODE_REL_SOFT);
1201 op->thrtimer.function = bcm_rx_thr_handler;
1202
1203 /* add this bcm_op to the list of the rx_ops */
1204 list_add(&op->list, &bo->rx_ops);
1205
1206 /* call can_rx_register() */
1207 do_rx_register = 1;
1208
1209 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1210
1211 /* check flags */
1212
1213 if (op->flags & RX_RTR_FRAME) {
1214 struct canfd_frame *frame0 = op->frames;
1215
1216 /* no timers in RTR-mode */
1217 hrtimer_cancel(&op->thrtimer);
1218 hrtimer_cancel(&op->timer);
1219
1220 /*
1221 * funny feature in RX(!)_SETUP only for RTR-mode:
1222 * copy can_id into frame BUT without RTR-flag to
1223 * prevent a full-load-loopback-test ... ;-]
1224 */
1225 if ((op->flags & TX_CP_CAN_ID) ||
1226 (frame0->can_id == op->can_id))
1227 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1228
1229 } else {
1230 if (op->flags & SETTIMER) {
1231
1232 /* set timer value */
1233 op->ival1 = msg_head->ival1;
1234 op->ival2 = msg_head->ival2;
1235 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1236 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1237
1238 /* disable an active timer due to zero value? */
1239 if (!op->kt_ival1)
1240 hrtimer_cancel(&op->timer);
1241
1242 /*
1243 * In any case cancel the throttle timer, flush
1244 * potentially blocked msgs and reset throttle handling
1245 */
1246 op->kt_lastmsg = 0;
1247 hrtimer_cancel(&op->thrtimer);
1248 bcm_rx_thr_flush(op);
1249 }
1250
1251 if ((op->flags & STARTTIMER) && op->kt_ival1)
1252 hrtimer_start(&op->timer, op->kt_ival1,
1253 HRTIMER_MODE_REL_SOFT);
1254 }
1255
1256 /* now we can register for can_ids, if we added a new bcm_op */
1257 if (do_rx_register) {
1258 if (ifindex) {
1259 struct net_device *dev;
1260
1261 dev = dev_get_by_index(sock_net(sk), ifindex);
1262 if (dev) {
1263 err = can_rx_register(sock_net(sk), dev,
1264 op->can_id,
1265 REGMASK(op->can_id),
1266 bcm_rx_handler, op,
1267 "bcm", sk);
1268
1269 op->rx_reg_dev = dev;
1270 dev_put(dev);
1271 }
1272
1273 } else
1274 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1275 REGMASK(op->can_id),
1276 bcm_rx_handler, op, "bcm", sk);
1277 if (err) {
1278 /* this bcm rx op is broken -> remove it */
1279 list_del(&op->list);
1280 bcm_remove_op(op);
1281 return err;
1282 }
1283 }
1284
1285 return msg_head->nframes * op->cfsiz + MHSIZ;
1286}
1287
1288/*
1289 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1290 */
1291static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1292 int cfsiz)
1293{
1294 struct sk_buff *skb;
1295 struct net_device *dev;
1296 int err;
1297
1298 /* we need a real device to send frames */
1299 if (!ifindex)
1300 return -ENODEV;
1301
1302 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1303 if (!skb)
1304 return -ENOMEM;
1305
1306 can_skb_reserve(skb);
1307
1308 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1309 if (err < 0) {
1310 kfree_skb(skb);
1311 return err;
1312 }
1313
1314 dev = dev_get_by_index(sock_net(sk), ifindex);
1315 if (!dev) {
1316 kfree_skb(skb);
1317 return -ENODEV;
1318 }
1319
1320 can_skb_prv(skb)->ifindex = dev->ifindex;
1321 can_skb_prv(skb)->skbcnt = 0;
1322 skb->dev = dev;
1323 can_skb_set_owner(skb, sk);
1324 err = can_send(skb, 1); /* send with loopback */
1325 dev_put(dev);
1326
1327 if (err)
1328 return err;
1329
1330 return cfsiz + MHSIZ;
1331}
1332
1333/*
1334 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1335 */
1336static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1337{
1338 struct sock *sk = sock->sk;
1339 struct bcm_sock *bo = bcm_sk(sk);
1340 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1341 struct bcm_msg_head msg_head;
1342 int cfsiz;
1343 int ret; /* read bytes or error codes as return value */
1344
1345 if (!bo->bound)
1346 return -ENOTCONN;
1347
1348 /* check for valid message length from userspace */
1349 if (size < MHSIZ)
1350 return -EINVAL;
1351
1352 /* read message head information */
1353 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1354 if (ret < 0)
1355 return ret;
1356
1357 cfsiz = CFSIZ(msg_head.flags);
1358 if ((size - MHSIZ) % cfsiz)
1359 return -EINVAL;
1360
1361 /* check for alternative ifindex for this bcm_op */
1362
1363 if (!ifindex && msg->msg_name) {
1364 /* no bound device as default => check msg_name */
1365 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1366
1367 if (msg->msg_namelen < BCM_MIN_NAMELEN)
1368 return -EINVAL;
1369
1370 if (addr->can_family != AF_CAN)
1371 return -EINVAL;
1372
1373 /* ifindex from sendto() */
1374 ifindex = addr->can_ifindex;
1375
1376 if (ifindex) {
1377 struct net_device *dev;
1378
1379 dev = dev_get_by_index(sock_net(sk), ifindex);
1380 if (!dev)
1381 return -ENODEV;
1382
1383 if (dev->type != ARPHRD_CAN) {
1384 dev_put(dev);
1385 return -ENODEV;
1386 }
1387
1388 dev_put(dev);
1389 }
1390 }
1391
1392 lock_sock(sk);
1393
1394 switch (msg_head.opcode) {
1395
1396 case TX_SETUP:
1397 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1398 break;
1399
1400 case RX_SETUP:
1401 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1402 break;
1403
1404 case TX_DELETE:
1405 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1406 ret = MHSIZ;
1407 else
1408 ret = -EINVAL;
1409 break;
1410
1411 case RX_DELETE:
1412 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1413 ret = MHSIZ;
1414 else
1415 ret = -EINVAL;
1416 break;
1417
1418 case TX_READ:
1419 /* reuse msg_head for the reply to TX_READ */
1420 msg_head.opcode = TX_STATUS;
1421 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1422 break;
1423
1424 case RX_READ:
1425 /* reuse msg_head for the reply to RX_READ */
1426 msg_head.opcode = RX_STATUS;
1427 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1428 break;
1429
1430 case TX_SEND:
1431 /* we need exactly one CAN frame behind the msg head */
1432 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1433 ret = -EINVAL;
1434 else
1435 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1436 break;
1437
1438 default:
1439 ret = -EINVAL;
1440 break;
1441 }
1442
1443 release_sock(sk);
1444
1445 return ret;
1446}
1447
1448/*
1449 * notification handler for netdevice status changes
1450 */
1451static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1452 struct net_device *dev)
1453{
1454 struct sock *sk = &bo->sk;
1455 struct bcm_op *op;
1456 int notify_enodev = 0;
1457
1458 if (!net_eq(dev_net(dev), sock_net(sk)))
1459 return;
1460
1461 switch (msg) {
1462
1463 case NETDEV_UNREGISTER:
1464 lock_sock(sk);
1465
1466 /* remove device specific receive entries */
1467 list_for_each_entry(op, &bo->rx_ops, list)
1468 if (op->rx_reg_dev == dev)
1469 bcm_rx_unreg(dev, op);
1470
1471 /* remove device reference, if this is our bound device */
1472 if (bo->bound && bo->ifindex == dev->ifindex) {
1473#if IS_ENABLED(CONFIG_PROC_FS)
1474 if (sock_net(sk)->can.bcmproc_dir && bo->bcm_proc_read) {
1475 remove_proc_entry(bo->procname, sock_net(sk)->can.bcmproc_dir);
1476 bo->bcm_proc_read = NULL;
1477 }
1478#endif
1479 bo->bound = 0;
1480 bo->ifindex = 0;
1481 notify_enodev = 1;
1482 }
1483
1484 release_sock(sk);
1485
1486 if (notify_enodev) {
1487 sk->sk_err = ENODEV;
1488 if (!sock_flag(sk, SOCK_DEAD))
1489 sk_error_report(sk);
1490 }
1491 break;
1492
1493 case NETDEV_DOWN:
1494 if (bo->bound && bo->ifindex == dev->ifindex) {
1495 sk->sk_err = ENETDOWN;
1496 if (!sock_flag(sk, SOCK_DEAD))
1497 sk_error_report(sk);
1498 }
1499 }
1500}
1501
1502static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1503 void *ptr)
1504{
1505 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1506
1507 if (dev->type != ARPHRD_CAN)
1508 return NOTIFY_DONE;
1509 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1510 return NOTIFY_DONE;
1511 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1512 return NOTIFY_DONE;
1513
1514 spin_lock(&bcm_notifier_lock);
1515 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1516 spin_unlock(&bcm_notifier_lock);
1517 bcm_notify(bcm_busy_notifier, msg, dev);
1518 spin_lock(&bcm_notifier_lock);
1519 }
1520 bcm_busy_notifier = NULL;
1521 spin_unlock(&bcm_notifier_lock);
1522 return NOTIFY_DONE;
1523}
1524
1525/*
1526 * initial settings for all BCM sockets to be set at socket creation time
1527 */
1528static int bcm_init(struct sock *sk)
1529{
1530 struct bcm_sock *bo = bcm_sk(sk);
1531
1532 bo->bound = 0;
1533 bo->ifindex = 0;
1534 bo->dropped_usr_msgs = 0;
1535 bo->bcm_proc_read = NULL;
1536
1537 INIT_LIST_HEAD(&bo->tx_ops);
1538 INIT_LIST_HEAD(&bo->rx_ops);
1539
1540 /* set notifier */
1541 spin_lock(&bcm_notifier_lock);
1542 list_add_tail(&bo->notifier, &bcm_notifier_list);
1543 spin_unlock(&bcm_notifier_lock);
1544
1545 return 0;
1546}
1547
1548/*
1549 * standard socket functions
1550 */
1551static int bcm_release(struct socket *sock)
1552{
1553 struct sock *sk = sock->sk;
1554 struct net *net;
1555 struct bcm_sock *bo;
1556 struct bcm_op *op, *next;
1557
1558 if (!sk)
1559 return 0;
1560
1561 net = sock_net(sk);
1562 bo = bcm_sk(sk);
1563
1564 /* remove bcm_ops, timer, rx_unregister(), etc. */
1565
1566 spin_lock(&bcm_notifier_lock);
1567 while (bcm_busy_notifier == bo) {
1568 spin_unlock(&bcm_notifier_lock);
1569 schedule_timeout_uninterruptible(1);
1570 spin_lock(&bcm_notifier_lock);
1571 }
1572 list_del(&bo->notifier);
1573 spin_unlock(&bcm_notifier_lock);
1574
1575 lock_sock(sk);
1576
1577#if IS_ENABLED(CONFIG_PROC_FS)
1578 /* remove procfs entry */
1579 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1580 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1581#endif /* CONFIG_PROC_FS */
1582
1583 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1584 bcm_remove_op(op);
1585
1586 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1587 /*
1588 * Don't care if we're bound or not (due to netdev problems)
1589 * can_rx_unregister() is always a save thing to do here.
1590 */
1591 if (op->ifindex) {
1592 /*
1593 * Only remove subscriptions that had not
1594 * been removed due to NETDEV_UNREGISTER
1595 * in bcm_notifier()
1596 */
1597 if (op->rx_reg_dev) {
1598 struct net_device *dev;
1599
1600 dev = dev_get_by_index(net, op->ifindex);
1601 if (dev) {
1602 bcm_rx_unreg(dev, op);
1603 dev_put(dev);
1604 }
1605 }
1606 } else
1607 can_rx_unregister(net, NULL, op->can_id,
1608 REGMASK(op->can_id),
1609 bcm_rx_handler, op);
1610
1611 }
1612
1613 synchronize_rcu();
1614
1615 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1616 bcm_remove_op(op);
1617
1618 /* remove device reference */
1619 if (bo->bound) {
1620 bo->bound = 0;
1621 bo->ifindex = 0;
1622 }
1623
1624 sock_orphan(sk);
1625 sock->sk = NULL;
1626
1627 release_sock(sk);
1628 sock_put(sk);
1629
1630 return 0;
1631}
1632
1633static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1634 int flags)
1635{
1636 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1637 struct sock *sk = sock->sk;
1638 struct bcm_sock *bo = bcm_sk(sk);
1639 struct net *net = sock_net(sk);
1640 int ret = 0;
1641
1642 if (len < BCM_MIN_NAMELEN)
1643 return -EINVAL;
1644
1645 lock_sock(sk);
1646
1647 if (bo->bound) {
1648 ret = -EISCONN;
1649 goto fail;
1650 }
1651
1652 /* bind a device to this socket */
1653 if (addr->can_ifindex) {
1654 struct net_device *dev;
1655
1656 dev = dev_get_by_index(net, addr->can_ifindex);
1657 if (!dev) {
1658 ret = -ENODEV;
1659 goto fail;
1660 }
1661 if (dev->type != ARPHRD_CAN) {
1662 dev_put(dev);
1663 ret = -ENODEV;
1664 goto fail;
1665 }
1666
1667 bo->ifindex = dev->ifindex;
1668 dev_put(dev);
1669
1670 } else {
1671 /* no interface reference for ifindex = 0 ('any' CAN device) */
1672 bo->ifindex = 0;
1673 }
1674
1675#if IS_ENABLED(CONFIG_PROC_FS)
1676 if (net->can.bcmproc_dir) {
1677 /* unique socket address as filename */
1678 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1679 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1680 net->can.bcmproc_dir,
1681 bcm_proc_show, sk);
1682 if (!bo->bcm_proc_read) {
1683 ret = -ENOMEM;
1684 goto fail;
1685 }
1686 }
1687#endif /* CONFIG_PROC_FS */
1688
1689 bo->bound = 1;
1690
1691fail:
1692 release_sock(sk);
1693
1694 return ret;
1695}
1696
1697static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1698 int flags)
1699{
1700 struct sock *sk = sock->sk;
1701 struct sk_buff *skb;
1702 int error = 0;
1703 int err;
1704
1705 skb = skb_recv_datagram(sk, flags, &error);
1706 if (!skb)
1707 return error;
1708
1709 if (skb->len < size)
1710 size = skb->len;
1711
1712 err = memcpy_to_msg(msg, skb->data, size);
1713 if (err < 0) {
1714 skb_free_datagram(sk, skb);
1715 return err;
1716 }
1717
1718 sock_recv_cmsgs(msg, sk, skb);
1719
1720 if (msg->msg_name) {
1721 __sockaddr_check_size(BCM_MIN_NAMELEN);
1722 msg->msg_namelen = BCM_MIN_NAMELEN;
1723 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1724 }
1725
1726 /* assign the flags that have been recorded in bcm_send_to_user() */
1727 msg->msg_flags |= *(bcm_flags(skb));
1728
1729 skb_free_datagram(sk, skb);
1730
1731 return size;
1732}
1733
1734static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1735 unsigned long arg)
1736{
1737 /* no ioctls for socket layer -> hand it down to NIC layer */
1738 return -ENOIOCTLCMD;
1739}
1740
1741static const struct proto_ops bcm_ops = {
1742 .family = PF_CAN,
1743 .release = bcm_release,
1744 .bind = sock_no_bind,
1745 .connect = bcm_connect,
1746 .socketpair = sock_no_socketpair,
1747 .accept = sock_no_accept,
1748 .getname = sock_no_getname,
1749 .poll = datagram_poll,
1750 .ioctl = bcm_sock_no_ioctlcmd,
1751 .gettstamp = sock_gettstamp,
1752 .listen = sock_no_listen,
1753 .shutdown = sock_no_shutdown,
1754 .sendmsg = bcm_sendmsg,
1755 .recvmsg = bcm_recvmsg,
1756 .mmap = sock_no_mmap,
1757};
1758
1759static struct proto bcm_proto __read_mostly = {
1760 .name = "CAN_BCM",
1761 .owner = THIS_MODULE,
1762 .obj_size = sizeof(struct bcm_sock),
1763 .init = bcm_init,
1764};
1765
1766static const struct can_proto bcm_can_proto = {
1767 .type = SOCK_DGRAM,
1768 .protocol = CAN_BCM,
1769 .ops = &bcm_ops,
1770 .prot = &bcm_proto,
1771};
1772
1773static int canbcm_pernet_init(struct net *net)
1774{
1775#if IS_ENABLED(CONFIG_PROC_FS)
1776 /* create /proc/net/can-bcm directory */
1777 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1778#endif /* CONFIG_PROC_FS */
1779
1780 return 0;
1781}
1782
1783static void canbcm_pernet_exit(struct net *net)
1784{
1785#if IS_ENABLED(CONFIG_PROC_FS)
1786 /* remove /proc/net/can-bcm directory */
1787 if (net->can.bcmproc_dir)
1788 remove_proc_entry("can-bcm", net->proc_net);
1789#endif /* CONFIG_PROC_FS */
1790}
1791
1792static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1793 .init = canbcm_pernet_init,
1794 .exit = canbcm_pernet_exit,
1795};
1796
1797static struct notifier_block canbcm_notifier = {
1798 .notifier_call = bcm_notifier
1799};
1800
1801static int __init bcm_module_init(void)
1802{
1803 int err;
1804
1805 pr_info("can: broadcast manager protocol\n");
1806
1807 err = register_pernet_subsys(&canbcm_pernet_ops);
1808 if (err)
1809 return err;
1810
1811 err = register_netdevice_notifier(&canbcm_notifier);
1812 if (err)
1813 goto register_notifier_failed;
1814
1815 err = can_proto_register(&bcm_can_proto);
1816 if (err < 0) {
1817 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1818 goto register_proto_failed;
1819 }
1820
1821 return 0;
1822
1823register_proto_failed:
1824 unregister_netdevice_notifier(&canbcm_notifier);
1825register_notifier_failed:
1826 unregister_pernet_subsys(&canbcm_pernet_ops);
1827 return err;
1828}
1829
1830static void __exit bcm_module_exit(void)
1831{
1832 can_proto_unregister(&bcm_can_proto);
1833 unregister_netdevice_notifier(&canbcm_notifier);
1834 unregister_pernet_subsys(&canbcm_pernet_ops);
1835}
1836
1837module_init(bcm_module_init);
1838module_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);