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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) 2002-2016 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42#include <linux/module.h>
43#include <linux/init.h>
44#include <linux/interrupt.h>
45#include <linux/hrtimer.h>
46#include <linux/list.h>
47#include <linux/proc_fs.h>
48#include <linux/seq_file.h>
49#include <linux/uio.h>
50#include <linux/net.h>
51#include <linux/netdevice.h>
52#include <linux/socket.h>
53#include <linux/if_arp.h>
54#include <linux/skbuff.h>
55#include <linux/can.h>
56#include <linux/can/core.h>
57#include <linux/can/skb.h>
58#include <linux/can/bcm.h>
59#include <linux/slab.h>
60#include <net/sock.h>
61#include <net/net_namespace.h>
62
63/*
64 * To send multiple CAN frame content within TX_SETUP or to filter
65 * CAN messages with multiplex index within RX_SETUP, the number of
66 * different filters is limited to 256 due to the one byte index value.
67 */
68#define MAX_NFRAMES 256
69
70/* use of last_frames[index].flags */
71#define RX_RECV 0x40 /* received data for this element */
72#define RX_THR 0x80 /* element not been sent due to throttle feature */
73#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
74
75/* get best masking value for can_rx_register() for a given single can_id */
76#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
77 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
78 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
79
80#define CAN_BCM_VERSION "20161123"
81
82MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
83MODULE_LICENSE("Dual BSD/GPL");
84MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
85MODULE_ALIAS("can-proto-2");
86
87/*
88 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
89 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
90 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
91 */
92static inline u64 get_u64(const struct canfd_frame *cp, int offset)
93{
94 return *(u64 *)(cp->data + offset);
95}
96
97struct bcm_op {
98 struct list_head list;
99 int ifindex;
100 canid_t can_id;
101 u32 flags;
102 unsigned long frames_abs, frames_filtered;
103 struct bcm_timeval ival1, ival2;
104 struct hrtimer timer, thrtimer;
105 struct tasklet_struct tsklet, thrtsklet;
106 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
107 int rx_ifindex;
108 int cfsiz;
109 u32 count;
110 u32 nframes;
111 u32 currframe;
112 /* void pointers to arrays of struct can[fd]_frame */
113 void *frames;
114 void *last_frames;
115 struct canfd_frame sframe;
116 struct canfd_frame last_sframe;
117 struct sock *sk;
118 struct net_device *rx_reg_dev;
119};
120
121static struct proc_dir_entry *proc_dir;
122
123struct bcm_sock {
124 struct sock sk;
125 int bound;
126 int ifindex;
127 struct notifier_block notifier;
128 struct list_head rx_ops;
129 struct list_head tx_ops;
130 unsigned long dropped_usr_msgs;
131 struct proc_dir_entry *bcm_proc_read;
132 char procname [32]; /* inode number in decimal with \0 */
133};
134
135static inline struct bcm_sock *bcm_sk(const struct sock *sk)
136{
137 return (struct bcm_sock *)sk;
138}
139
140static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
141{
142 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
143}
144
145#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
146#define OPSIZ sizeof(struct bcm_op)
147#define MHSIZ sizeof(struct bcm_msg_head)
148
149/*
150 * procfs functions
151 */
152static char *bcm_proc_getifname(char *result, int ifindex)
153{
154 struct net_device *dev;
155
156 if (!ifindex)
157 return "any";
158
159 rcu_read_lock();
160 dev = dev_get_by_index_rcu(&init_net, ifindex);
161 if (dev)
162 strcpy(result, dev->name);
163 else
164 strcpy(result, "???");
165 rcu_read_unlock();
166
167 return result;
168}
169
170static int bcm_proc_show(struct seq_file *m, void *v)
171{
172 char ifname[IFNAMSIZ];
173 struct sock *sk = (struct sock *)m->private;
174 struct bcm_sock *bo = bcm_sk(sk);
175 struct bcm_op *op;
176
177 seq_printf(m, ">>> socket %pK", sk->sk_socket);
178 seq_printf(m, " / sk %pK", sk);
179 seq_printf(m, " / bo %pK", bo);
180 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
181 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
182 seq_printf(m, " <<<\n");
183
184 list_for_each_entry(op, &bo->rx_ops, list) {
185
186 unsigned long reduction;
187
188 /* print only active entries & prevent division by zero */
189 if (!op->frames_abs)
190 continue;
191
192 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
193 bcm_proc_getifname(ifname, op->ifindex));
194
195 if (op->flags & CAN_FD_FRAME)
196 seq_printf(m, "(%u)", op->nframes);
197 else
198 seq_printf(m, "[%u]", op->nframes);
199
200 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
201
202 if (op->kt_ival1)
203 seq_printf(m, "timeo=%lld ",
204 (long long)ktime_to_us(op->kt_ival1));
205
206 if (op->kt_ival2)
207 seq_printf(m, "thr=%lld ",
208 (long long)ktime_to_us(op->kt_ival2));
209
210 seq_printf(m, "# recv %ld (%ld) => reduction: ",
211 op->frames_filtered, op->frames_abs);
212
213 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
214
215 seq_printf(m, "%s%ld%%\n",
216 (reduction == 100) ? "near " : "", reduction);
217 }
218
219 list_for_each_entry(op, &bo->tx_ops, list) {
220
221 seq_printf(m, "tx_op: %03X %s ", op->can_id,
222 bcm_proc_getifname(ifname, op->ifindex));
223
224 if (op->flags & CAN_FD_FRAME)
225 seq_printf(m, "(%u) ", op->nframes);
226 else
227 seq_printf(m, "[%u] ", op->nframes);
228
229 if (op->kt_ival1)
230 seq_printf(m, "t1=%lld ",
231 (long long)ktime_to_us(op->kt_ival1));
232
233 if (op->kt_ival2)
234 seq_printf(m, "t2=%lld ",
235 (long long)ktime_to_us(op->kt_ival2));
236
237 seq_printf(m, "# sent %ld\n", op->frames_abs);
238 }
239 seq_putc(m, '\n');
240 return 0;
241}
242
243static int bcm_proc_open(struct inode *inode, struct file *file)
244{
245 return single_open(file, bcm_proc_show, PDE_DATA(inode));
246}
247
248static const struct file_operations bcm_proc_fops = {
249 .owner = THIS_MODULE,
250 .open = bcm_proc_open,
251 .read = seq_read,
252 .llseek = seq_lseek,
253 .release = single_release,
254};
255
256/*
257 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
258 * of the given bcm tx op
259 */
260static void bcm_can_tx(struct bcm_op *op)
261{
262 struct sk_buff *skb;
263 struct net_device *dev;
264 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
265
266 /* no target device? => exit */
267 if (!op->ifindex)
268 return;
269
270 dev = dev_get_by_index(&init_net, op->ifindex);
271 if (!dev) {
272 /* RFC: should this bcm_op remove itself here? */
273 return;
274 }
275
276 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
277 if (!skb)
278 goto out;
279
280 can_skb_reserve(skb);
281 can_skb_prv(skb)->ifindex = dev->ifindex;
282 can_skb_prv(skb)->skbcnt = 0;
283
284 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz);
285
286 /* send with loopback */
287 skb->dev = dev;
288 can_skb_set_owner(skb, op->sk);
289 can_send(skb, 1);
290
291 /* update statistics */
292 op->currframe++;
293 op->frames_abs++;
294
295 /* reached last frame? */
296 if (op->currframe >= op->nframes)
297 op->currframe = 0;
298out:
299 dev_put(dev);
300}
301
302/*
303 * bcm_send_to_user - send a BCM message to the userspace
304 * (consisting of bcm_msg_head + x CAN frames)
305 */
306static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
307 struct canfd_frame *frames, int has_timestamp)
308{
309 struct sk_buff *skb;
310 struct canfd_frame *firstframe;
311 struct sockaddr_can *addr;
312 struct sock *sk = op->sk;
313 unsigned int datalen = head->nframes * op->cfsiz;
314 int err;
315
316 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
317 if (!skb)
318 return;
319
320 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
321
322 if (head->nframes) {
323 /* CAN frames starting here */
324 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
325
326 memcpy(skb_put(skb, datalen), frames, datalen);
327
328 /*
329 * the BCM uses the flags-element of the canfd_frame
330 * structure for internal purposes. This is only
331 * relevant for updates that are generated by the
332 * BCM, where nframes is 1
333 */
334 if (head->nframes == 1)
335 firstframe->flags &= BCM_CAN_FLAGS_MASK;
336 }
337
338 if (has_timestamp) {
339 /* restore rx timestamp */
340 skb->tstamp = op->rx_stamp;
341 }
342
343 /*
344 * Put the datagram to the queue so that bcm_recvmsg() can
345 * get it from there. We need to pass the interface index to
346 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
347 * containing the interface index.
348 */
349
350 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
351 addr = (struct sockaddr_can *)skb->cb;
352 memset(addr, 0, sizeof(*addr));
353 addr->can_family = AF_CAN;
354 addr->can_ifindex = op->rx_ifindex;
355
356 err = sock_queue_rcv_skb(sk, skb);
357 if (err < 0) {
358 struct bcm_sock *bo = bcm_sk(sk);
359
360 kfree_skb(skb);
361 /* don't care about overflows in this statistic */
362 bo->dropped_usr_msgs++;
363 }
364}
365
366static void bcm_tx_start_timer(struct bcm_op *op)
367{
368 if (op->kt_ival1 && op->count)
369 hrtimer_start(&op->timer,
370 ktime_add(ktime_get(), op->kt_ival1),
371 HRTIMER_MODE_ABS);
372 else if (op->kt_ival2)
373 hrtimer_start(&op->timer,
374 ktime_add(ktime_get(), op->kt_ival2),
375 HRTIMER_MODE_ABS);
376}
377
378static void bcm_tx_timeout_tsklet(unsigned long data)
379{
380 struct bcm_op *op = (struct bcm_op *)data;
381 struct bcm_msg_head msg_head;
382
383 if (op->kt_ival1 && (op->count > 0)) {
384
385 op->count--;
386 if (!op->count && (op->flags & TX_COUNTEVT)) {
387
388 /* create notification to user */
389 msg_head.opcode = TX_EXPIRED;
390 msg_head.flags = op->flags;
391 msg_head.count = op->count;
392 msg_head.ival1 = op->ival1;
393 msg_head.ival2 = op->ival2;
394 msg_head.can_id = op->can_id;
395 msg_head.nframes = 0;
396
397 bcm_send_to_user(op, &msg_head, NULL, 0);
398 }
399 bcm_can_tx(op);
400
401 } else if (op->kt_ival2)
402 bcm_can_tx(op);
403
404 bcm_tx_start_timer(op);
405}
406
407/*
408 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
409 */
410static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
411{
412 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
413
414 tasklet_schedule(&op->tsklet);
415
416 return HRTIMER_NORESTART;
417}
418
419/*
420 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
421 */
422static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
423{
424 struct bcm_msg_head head;
425
426 /* update statistics */
427 op->frames_filtered++;
428
429 /* prevent statistics overflow */
430 if (op->frames_filtered > ULONG_MAX/100)
431 op->frames_filtered = op->frames_abs = 0;
432
433 /* this element is not throttled anymore */
434 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
435
436 head.opcode = RX_CHANGED;
437 head.flags = op->flags;
438 head.count = op->count;
439 head.ival1 = op->ival1;
440 head.ival2 = op->ival2;
441 head.can_id = op->can_id;
442 head.nframes = 1;
443
444 bcm_send_to_user(op, &head, data, 1);
445}
446
447/*
448 * bcm_rx_update_and_send - process a detected relevant receive content change
449 * 1. update the last received data
450 * 2. send a notification to the user (if possible)
451 */
452static void bcm_rx_update_and_send(struct bcm_op *op,
453 struct canfd_frame *lastdata,
454 const struct canfd_frame *rxdata)
455{
456 memcpy(lastdata, rxdata, op->cfsiz);
457
458 /* mark as used and throttled by default */
459 lastdata->flags |= (RX_RECV|RX_THR);
460
461 /* throttling mode inactive ? */
462 if (!op->kt_ival2) {
463 /* send RX_CHANGED to the user immediately */
464 bcm_rx_changed(op, lastdata);
465 return;
466 }
467
468 /* with active throttling timer we are just done here */
469 if (hrtimer_active(&op->thrtimer))
470 return;
471
472 /* first reception with enabled throttling mode */
473 if (!op->kt_lastmsg)
474 goto rx_changed_settime;
475
476 /* got a second frame inside a potential throttle period? */
477 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
478 ktime_to_us(op->kt_ival2)) {
479 /* do not send the saved data - only start throttle timer */
480 hrtimer_start(&op->thrtimer,
481 ktime_add(op->kt_lastmsg, op->kt_ival2),
482 HRTIMER_MODE_ABS);
483 return;
484 }
485
486 /* the gap was that big, that throttling was not needed here */
487rx_changed_settime:
488 bcm_rx_changed(op, lastdata);
489 op->kt_lastmsg = ktime_get();
490}
491
492/*
493 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
494 * received data stored in op->last_frames[]
495 */
496static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
497 const struct canfd_frame *rxdata)
498{
499 struct canfd_frame *cf = op->frames + op->cfsiz * index;
500 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
501 int i;
502
503 /*
504 * no one uses the MSBs of flags for comparison,
505 * so we use it here to detect the first time of reception
506 */
507
508 if (!(lcf->flags & RX_RECV)) {
509 /* received data for the first time => send update to user */
510 bcm_rx_update_and_send(op, lcf, rxdata);
511 return;
512 }
513
514 /* do a real check in CAN frame data section */
515 for (i = 0; i < rxdata->len; i += 8) {
516 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
517 (get_u64(cf, i) & get_u64(lcf, i))) {
518 bcm_rx_update_and_send(op, lcf, rxdata);
519 return;
520 }
521 }
522
523 if (op->flags & RX_CHECK_DLC) {
524 /* do a real check in CAN frame length */
525 if (rxdata->len != lcf->len) {
526 bcm_rx_update_and_send(op, lcf, rxdata);
527 return;
528 }
529 }
530}
531
532/*
533 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
534 */
535static void bcm_rx_starttimer(struct bcm_op *op)
536{
537 if (op->flags & RX_NO_AUTOTIMER)
538 return;
539
540 if (op->kt_ival1)
541 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
542}
543
544static void bcm_rx_timeout_tsklet(unsigned long data)
545{
546 struct bcm_op *op = (struct bcm_op *)data;
547 struct bcm_msg_head msg_head;
548
549 /* create notification to user */
550 msg_head.opcode = RX_TIMEOUT;
551 msg_head.flags = op->flags;
552 msg_head.count = op->count;
553 msg_head.ival1 = op->ival1;
554 msg_head.ival2 = op->ival2;
555 msg_head.can_id = op->can_id;
556 msg_head.nframes = 0;
557
558 bcm_send_to_user(op, &msg_head, NULL, 0);
559}
560
561/*
562 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
563 */
564static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
565{
566 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
567
568 /* schedule before NET_RX_SOFTIRQ */
569 tasklet_hi_schedule(&op->tsklet);
570
571 /* no restart of the timer is done here! */
572
573 /* if user wants to be informed, when cyclic CAN-Messages come back */
574 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
575 /* clear received CAN frames to indicate 'nothing received' */
576 memset(op->last_frames, 0, op->nframes * op->cfsiz);
577 }
578
579 return HRTIMER_NORESTART;
580}
581
582/*
583 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
584 */
585static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
586 unsigned int index)
587{
588 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
589
590 if ((op->last_frames) && (lcf->flags & RX_THR)) {
591 if (update)
592 bcm_rx_changed(op, lcf);
593 return 1;
594 }
595 return 0;
596}
597
598/*
599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
600 *
601 * update == 0 : just check if throttled data is available (any irq context)
602 * update == 1 : check and send throttled data to userspace (soft_irq context)
603 */
604static int bcm_rx_thr_flush(struct bcm_op *op, int update)
605{
606 int updated = 0;
607
608 if (op->nframes > 1) {
609 unsigned int i;
610
611 /* for MUX filter we start at index 1 */
612 for (i = 1; i < op->nframes; i++)
613 updated += bcm_rx_do_flush(op, update, i);
614
615 } else {
616 /* for RX_FILTER_ID and simple filter */
617 updated += bcm_rx_do_flush(op, update, 0);
618 }
619
620 return updated;
621}
622
623static void bcm_rx_thr_tsklet(unsigned long data)
624{
625 struct bcm_op *op = (struct bcm_op *)data;
626
627 /* push the changed data to the userspace */
628 bcm_rx_thr_flush(op, 1);
629}
630
631/*
632 * bcm_rx_thr_handler - the time for blocked content updates is over now:
633 * Check for throttled data and send it to the userspace
634 */
635static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
636{
637 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
638
639 tasklet_schedule(&op->thrtsklet);
640
641 if (bcm_rx_thr_flush(op, 0)) {
642 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
643 return HRTIMER_RESTART;
644 } else {
645 /* rearm throttle handling */
646 op->kt_lastmsg = 0;
647 return HRTIMER_NORESTART;
648 }
649}
650
651/*
652 * bcm_rx_handler - handle a CAN frame reception
653 */
654static void bcm_rx_handler(struct sk_buff *skb, void *data)
655{
656 struct bcm_op *op = (struct bcm_op *)data;
657 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
658 unsigned int i;
659
660 if (op->can_id != rxframe->can_id)
661 return;
662
663 /* make sure to handle the correct frame type (CAN / CAN FD) */
664 if (skb->len != op->cfsiz)
665 return;
666
667 /* disable timeout */
668 hrtimer_cancel(&op->timer);
669
670 /* save rx timestamp */
671 op->rx_stamp = skb->tstamp;
672 /* save originator for recvfrom() */
673 op->rx_ifindex = skb->dev->ifindex;
674 /* update statistics */
675 op->frames_abs++;
676
677 if (op->flags & RX_RTR_FRAME) {
678 /* send reply for RTR-request (placed in op->frames[0]) */
679 bcm_can_tx(op);
680 return;
681 }
682
683 if (op->flags & RX_FILTER_ID) {
684 /* the easiest case */
685 bcm_rx_update_and_send(op, op->last_frames, rxframe);
686 goto rx_starttimer;
687 }
688
689 if (op->nframes == 1) {
690 /* simple compare with index 0 */
691 bcm_rx_cmp_to_index(op, 0, rxframe);
692 goto rx_starttimer;
693 }
694
695 if (op->nframes > 1) {
696 /*
697 * multiplex compare
698 *
699 * find the first multiplex mask that fits.
700 * Remark: The MUX-mask is stored in index 0 - but only the
701 * first 64 bits of the frame data[] are relevant (CAN FD)
702 */
703
704 for (i = 1; i < op->nframes; i++) {
705 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
706 (get_u64(op->frames, 0) &
707 get_u64(op->frames + op->cfsiz * i, 0))) {
708 bcm_rx_cmp_to_index(op, i, rxframe);
709 break;
710 }
711 }
712 }
713
714rx_starttimer:
715 bcm_rx_starttimer(op);
716}
717
718/*
719 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
720 */
721static struct bcm_op *bcm_find_op(struct list_head *ops,
722 struct bcm_msg_head *mh, int ifindex)
723{
724 struct bcm_op *op;
725
726 list_for_each_entry(op, ops, list) {
727 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
728 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
729 return op;
730 }
731
732 return NULL;
733}
734
735static void bcm_remove_op(struct bcm_op *op)
736{
737 if (op->tsklet.func) {
738 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
739 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
740 hrtimer_active(&op->timer)) {
741 hrtimer_cancel(&op->timer);
742 tasklet_kill(&op->tsklet);
743 }
744 }
745
746 if (op->thrtsklet.func) {
747 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
748 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
749 hrtimer_active(&op->thrtimer)) {
750 hrtimer_cancel(&op->thrtimer);
751 tasklet_kill(&op->thrtsklet);
752 }
753 }
754
755 if ((op->frames) && (op->frames != &op->sframe))
756 kfree(op->frames);
757
758 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
759 kfree(op->last_frames);
760
761 kfree(op);
762}
763
764static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
765{
766 if (op->rx_reg_dev == dev) {
767 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
768 bcm_rx_handler, op);
769
770 /* mark as removed subscription */
771 op->rx_reg_dev = NULL;
772 } else
773 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
774 "mismatch %p %p\n", op->rx_reg_dev, dev);
775}
776
777/*
778 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
779 */
780static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
781 int ifindex)
782{
783 struct bcm_op *op, *n;
784
785 list_for_each_entry_safe(op, n, ops, list) {
786 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
787 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
788
789 /*
790 * Don't care if we're bound or not (due to netdev
791 * problems) can_rx_unregister() is always a save
792 * thing to do here.
793 */
794 if (op->ifindex) {
795 /*
796 * Only remove subscriptions that had not
797 * been removed due to NETDEV_UNREGISTER
798 * in bcm_notifier()
799 */
800 if (op->rx_reg_dev) {
801 struct net_device *dev;
802
803 dev = dev_get_by_index(&init_net,
804 op->ifindex);
805 if (dev) {
806 bcm_rx_unreg(dev, op);
807 dev_put(dev);
808 }
809 }
810 } else
811 can_rx_unregister(NULL, op->can_id,
812 REGMASK(op->can_id),
813 bcm_rx_handler, op);
814
815 list_del(&op->list);
816 bcm_remove_op(op);
817 return 1; /* done */
818 }
819 }
820
821 return 0; /* not found */
822}
823
824/*
825 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
826 */
827static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
828 int ifindex)
829{
830 struct bcm_op *op, *n;
831
832 list_for_each_entry_safe(op, n, ops, list) {
833 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
834 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
835 list_del(&op->list);
836 bcm_remove_op(op);
837 return 1; /* done */
838 }
839 }
840
841 return 0; /* not found */
842}
843
844/*
845 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
846 */
847static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
848 int ifindex)
849{
850 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
851
852 if (!op)
853 return -EINVAL;
854
855 /* put current values into msg_head */
856 msg_head->flags = op->flags;
857 msg_head->count = op->count;
858 msg_head->ival1 = op->ival1;
859 msg_head->ival2 = op->ival2;
860 msg_head->nframes = op->nframes;
861
862 bcm_send_to_user(op, msg_head, op->frames, 0);
863
864 return MHSIZ;
865}
866
867/*
868 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
869 */
870static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
871 int ifindex, struct sock *sk)
872{
873 struct bcm_sock *bo = bcm_sk(sk);
874 struct bcm_op *op;
875 struct canfd_frame *cf;
876 unsigned int i;
877 int err;
878
879 /* we need a real device to send frames */
880 if (!ifindex)
881 return -ENODEV;
882
883 /* check nframes boundaries - we need at least one CAN frame */
884 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
885 return -EINVAL;
886
887 /* check the given can_id */
888 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
889 if (op) {
890 /* update existing BCM operation */
891
892 /*
893 * Do we need more space for the CAN frames than currently
894 * allocated? -> This is a _really_ unusual use-case and
895 * therefore (complexity / locking) it is not supported.
896 */
897 if (msg_head->nframes > op->nframes)
898 return -E2BIG;
899
900 /* update CAN frames content */
901 for (i = 0; i < msg_head->nframes; i++) {
902
903 cf = op->frames + op->cfsiz * i;
904 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
905
906 if (op->flags & CAN_FD_FRAME) {
907 if (cf->len > 64)
908 err = -EINVAL;
909 } else {
910 if (cf->len > 8)
911 err = -EINVAL;
912 }
913
914 if (err < 0)
915 return err;
916
917 if (msg_head->flags & TX_CP_CAN_ID) {
918 /* copy can_id into frame */
919 cf->can_id = msg_head->can_id;
920 }
921 }
922 op->flags = msg_head->flags;
923
924 } else {
925 /* insert new BCM operation for the given can_id */
926
927 op = kzalloc(OPSIZ, GFP_KERNEL);
928 if (!op)
929 return -ENOMEM;
930
931 op->can_id = msg_head->can_id;
932 op->cfsiz = CFSIZ(msg_head->flags);
933 op->flags = msg_head->flags;
934
935 /* create array for CAN frames and copy the data */
936 if (msg_head->nframes > 1) {
937 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
938 GFP_KERNEL);
939 if (!op->frames) {
940 kfree(op);
941 return -ENOMEM;
942 }
943 } else
944 op->frames = &op->sframe;
945
946 for (i = 0; i < msg_head->nframes; i++) {
947
948 cf = op->frames + op->cfsiz * i;
949 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
950
951 if (op->flags & CAN_FD_FRAME) {
952 if (cf->len > 64)
953 err = -EINVAL;
954 } else {
955 if (cf->len > 8)
956 err = -EINVAL;
957 }
958
959 if (err < 0) {
960 if (op->frames != &op->sframe)
961 kfree(op->frames);
962 kfree(op);
963 return err;
964 }
965
966 if (msg_head->flags & TX_CP_CAN_ID) {
967 /* copy can_id into frame */
968 cf->can_id = msg_head->can_id;
969 }
970 }
971
972 /* tx_ops never compare with previous received messages */
973 op->last_frames = NULL;
974
975 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
976 op->sk = sk;
977 op->ifindex = ifindex;
978
979 /* initialize uninitialized (kzalloc) structure */
980 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
981 op->timer.function = bcm_tx_timeout_handler;
982
983 /* initialize tasklet for tx countevent notification */
984 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
985 (unsigned long) op);
986
987 /* currently unused in tx_ops */
988 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
989
990 /* add this bcm_op to the list of the tx_ops */
991 list_add(&op->list, &bo->tx_ops);
992
993 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
994
995 if (op->nframes != msg_head->nframes) {
996 op->nframes = msg_head->nframes;
997 /* start multiple frame transmission with index 0 */
998 op->currframe = 0;
999 }
1000
1001 /* check flags */
1002
1003 if (op->flags & TX_RESET_MULTI_IDX) {
1004 /* start multiple frame transmission with index 0 */
1005 op->currframe = 0;
1006 }
1007
1008 if (op->flags & SETTIMER) {
1009 /* set timer values */
1010 op->count = msg_head->count;
1011 op->ival1 = msg_head->ival1;
1012 op->ival2 = msg_head->ival2;
1013 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1014 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1015
1016 /* disable an active timer due to zero values? */
1017 if (!op->kt_ival1 && !op->kt_ival2)
1018 hrtimer_cancel(&op->timer);
1019 }
1020
1021 if (op->flags & STARTTIMER) {
1022 hrtimer_cancel(&op->timer);
1023 /* spec: send CAN frame when starting timer */
1024 op->flags |= TX_ANNOUNCE;
1025 }
1026
1027 if (op->flags & TX_ANNOUNCE) {
1028 bcm_can_tx(op);
1029 if (op->count)
1030 op->count--;
1031 }
1032
1033 if (op->flags & STARTTIMER)
1034 bcm_tx_start_timer(op);
1035
1036 return msg_head->nframes * op->cfsiz + MHSIZ;
1037}
1038
1039/*
1040 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1041 */
1042static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1043 int ifindex, struct sock *sk)
1044{
1045 struct bcm_sock *bo = bcm_sk(sk);
1046 struct bcm_op *op;
1047 int do_rx_register;
1048 int err = 0;
1049
1050 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1051 /* be robust against wrong usage ... */
1052 msg_head->flags |= RX_FILTER_ID;
1053 /* ignore trailing garbage */
1054 msg_head->nframes = 0;
1055 }
1056
1057 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1058 if (msg_head->nframes > MAX_NFRAMES + 1)
1059 return -EINVAL;
1060
1061 if ((msg_head->flags & RX_RTR_FRAME) &&
1062 ((msg_head->nframes != 1) ||
1063 (!(msg_head->can_id & CAN_RTR_FLAG))))
1064 return -EINVAL;
1065
1066 /* check the given can_id */
1067 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1068 if (op) {
1069 /* update existing BCM operation */
1070
1071 /*
1072 * Do we need more space for the CAN frames than currently
1073 * allocated? -> This is a _really_ unusual use-case and
1074 * therefore (complexity / locking) it is not supported.
1075 */
1076 if (msg_head->nframes > op->nframes)
1077 return -E2BIG;
1078
1079 if (msg_head->nframes) {
1080 /* update CAN frames content */
1081 err = memcpy_from_msg(op->frames, msg,
1082 msg_head->nframes * op->cfsiz);
1083 if (err < 0)
1084 return err;
1085
1086 /* clear last_frames to indicate 'nothing received' */
1087 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1088 }
1089
1090 op->nframes = msg_head->nframes;
1091 op->flags = msg_head->flags;
1092
1093 /* Only an update -> do not call can_rx_register() */
1094 do_rx_register = 0;
1095
1096 } else {
1097 /* insert new BCM operation for the given can_id */
1098 op = kzalloc(OPSIZ, GFP_KERNEL);
1099 if (!op)
1100 return -ENOMEM;
1101
1102 op->can_id = msg_head->can_id;
1103 op->nframes = msg_head->nframes;
1104 op->cfsiz = CFSIZ(msg_head->flags);
1105 op->flags = msg_head->flags;
1106
1107 if (msg_head->nframes > 1) {
1108 /* create array for CAN frames and copy the data */
1109 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1110 GFP_KERNEL);
1111 if (!op->frames) {
1112 kfree(op);
1113 return -ENOMEM;
1114 }
1115
1116 /* create and init array for received CAN frames */
1117 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1118 GFP_KERNEL);
1119 if (!op->last_frames) {
1120 kfree(op->frames);
1121 kfree(op);
1122 return -ENOMEM;
1123 }
1124
1125 } else {
1126 op->frames = &op->sframe;
1127 op->last_frames = &op->last_sframe;
1128 }
1129
1130 if (msg_head->nframes) {
1131 err = memcpy_from_msg(op->frames, msg,
1132 msg_head->nframes * op->cfsiz);
1133 if (err < 0) {
1134 if (op->frames != &op->sframe)
1135 kfree(op->frames);
1136 if (op->last_frames != &op->last_sframe)
1137 kfree(op->last_frames);
1138 kfree(op);
1139 return err;
1140 }
1141 }
1142
1143 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1144 op->sk = sk;
1145 op->ifindex = ifindex;
1146
1147 /* ifindex for timeout events w/o previous frame reception */
1148 op->rx_ifindex = ifindex;
1149
1150 /* initialize uninitialized (kzalloc) structure */
1151 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1152 op->timer.function = bcm_rx_timeout_handler;
1153
1154 /* initialize tasklet for rx timeout notification */
1155 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1156 (unsigned long) op);
1157
1158 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1159 op->thrtimer.function = bcm_rx_thr_handler;
1160
1161 /* initialize tasklet for rx throttle handling */
1162 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1163 (unsigned long) op);
1164
1165 /* add this bcm_op to the list of the rx_ops */
1166 list_add(&op->list, &bo->rx_ops);
1167
1168 /* call can_rx_register() */
1169 do_rx_register = 1;
1170
1171 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1172
1173 /* check flags */
1174
1175 if (op->flags & RX_RTR_FRAME) {
1176 struct canfd_frame *frame0 = op->frames;
1177
1178 /* no timers in RTR-mode */
1179 hrtimer_cancel(&op->thrtimer);
1180 hrtimer_cancel(&op->timer);
1181
1182 /*
1183 * funny feature in RX(!)_SETUP only for RTR-mode:
1184 * copy can_id into frame BUT without RTR-flag to
1185 * prevent a full-load-loopback-test ... ;-]
1186 */
1187 if ((op->flags & TX_CP_CAN_ID) ||
1188 (frame0->can_id == op->can_id))
1189 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1190
1191 } else {
1192 if (op->flags & SETTIMER) {
1193
1194 /* set timer value */
1195 op->ival1 = msg_head->ival1;
1196 op->ival2 = msg_head->ival2;
1197 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1198 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1199
1200 /* disable an active timer due to zero value? */
1201 if (!op->kt_ival1)
1202 hrtimer_cancel(&op->timer);
1203
1204 /*
1205 * In any case cancel the throttle timer, flush
1206 * potentially blocked msgs and reset throttle handling
1207 */
1208 op->kt_lastmsg = 0;
1209 hrtimer_cancel(&op->thrtimer);
1210 bcm_rx_thr_flush(op, 1);
1211 }
1212
1213 if ((op->flags & STARTTIMER) && op->kt_ival1)
1214 hrtimer_start(&op->timer, op->kt_ival1,
1215 HRTIMER_MODE_REL);
1216 }
1217
1218 /* now we can register for can_ids, if we added a new bcm_op */
1219 if (do_rx_register) {
1220 if (ifindex) {
1221 struct net_device *dev;
1222
1223 dev = dev_get_by_index(&init_net, ifindex);
1224 if (dev) {
1225 err = can_rx_register(dev, op->can_id,
1226 REGMASK(op->can_id),
1227 bcm_rx_handler, op,
1228 "bcm", sk);
1229
1230 op->rx_reg_dev = dev;
1231 dev_put(dev);
1232 }
1233
1234 } else
1235 err = can_rx_register(NULL, op->can_id,
1236 REGMASK(op->can_id),
1237 bcm_rx_handler, op, "bcm", sk);
1238 if (err) {
1239 /* this bcm rx op is broken -> remove it */
1240 list_del(&op->list);
1241 bcm_remove_op(op);
1242 return err;
1243 }
1244 }
1245
1246 return msg_head->nframes * op->cfsiz + MHSIZ;
1247}
1248
1249/*
1250 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1251 */
1252static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1253 int cfsiz)
1254{
1255 struct sk_buff *skb;
1256 struct net_device *dev;
1257 int err;
1258
1259 /* we need a real device to send frames */
1260 if (!ifindex)
1261 return -ENODEV;
1262
1263 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1264 if (!skb)
1265 return -ENOMEM;
1266
1267 can_skb_reserve(skb);
1268
1269 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1270 if (err < 0) {
1271 kfree_skb(skb);
1272 return err;
1273 }
1274
1275 dev = dev_get_by_index(&init_net, ifindex);
1276 if (!dev) {
1277 kfree_skb(skb);
1278 return -ENODEV;
1279 }
1280
1281 can_skb_prv(skb)->ifindex = dev->ifindex;
1282 can_skb_prv(skb)->skbcnt = 0;
1283 skb->dev = dev;
1284 can_skb_set_owner(skb, sk);
1285 err = can_send(skb, 1); /* send with loopback */
1286 dev_put(dev);
1287
1288 if (err)
1289 return err;
1290
1291 return cfsiz + MHSIZ;
1292}
1293
1294/*
1295 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1296 */
1297static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1298{
1299 struct sock *sk = sock->sk;
1300 struct bcm_sock *bo = bcm_sk(sk);
1301 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1302 struct bcm_msg_head msg_head;
1303 int cfsiz;
1304 int ret; /* read bytes or error codes as return value */
1305
1306 if (!bo->bound)
1307 return -ENOTCONN;
1308
1309 /* check for valid message length from userspace */
1310 if (size < MHSIZ)
1311 return -EINVAL;
1312
1313 /* read message head information */
1314 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1315 if (ret < 0)
1316 return ret;
1317
1318 cfsiz = CFSIZ(msg_head.flags);
1319 if ((size - MHSIZ) % cfsiz)
1320 return -EINVAL;
1321
1322 /* check for alternative ifindex for this bcm_op */
1323
1324 if (!ifindex && msg->msg_name) {
1325 /* no bound device as default => check msg_name */
1326 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1327
1328 if (msg->msg_namelen < sizeof(*addr))
1329 return -EINVAL;
1330
1331 if (addr->can_family != AF_CAN)
1332 return -EINVAL;
1333
1334 /* ifindex from sendto() */
1335 ifindex = addr->can_ifindex;
1336
1337 if (ifindex) {
1338 struct net_device *dev;
1339
1340 dev = dev_get_by_index(&init_net, ifindex);
1341 if (!dev)
1342 return -ENODEV;
1343
1344 if (dev->type != ARPHRD_CAN) {
1345 dev_put(dev);
1346 return -ENODEV;
1347 }
1348
1349 dev_put(dev);
1350 }
1351 }
1352
1353 lock_sock(sk);
1354
1355 switch (msg_head.opcode) {
1356
1357 case TX_SETUP:
1358 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1359 break;
1360
1361 case RX_SETUP:
1362 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1363 break;
1364
1365 case TX_DELETE:
1366 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1367 ret = MHSIZ;
1368 else
1369 ret = -EINVAL;
1370 break;
1371
1372 case RX_DELETE:
1373 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1374 ret = MHSIZ;
1375 else
1376 ret = -EINVAL;
1377 break;
1378
1379 case TX_READ:
1380 /* reuse msg_head for the reply to TX_READ */
1381 msg_head.opcode = TX_STATUS;
1382 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1383 break;
1384
1385 case RX_READ:
1386 /* reuse msg_head for the reply to RX_READ */
1387 msg_head.opcode = RX_STATUS;
1388 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1389 break;
1390
1391 case TX_SEND:
1392 /* we need exactly one CAN frame behind the msg head */
1393 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1394 ret = -EINVAL;
1395 else
1396 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1397 break;
1398
1399 default:
1400 ret = -EINVAL;
1401 break;
1402 }
1403
1404 release_sock(sk);
1405
1406 return ret;
1407}
1408
1409/*
1410 * notification handler for netdevice status changes
1411 */
1412static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1413 void *ptr)
1414{
1415 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1416 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1417 struct sock *sk = &bo->sk;
1418 struct bcm_op *op;
1419 int notify_enodev = 0;
1420
1421 if (!net_eq(dev_net(dev), &init_net))
1422 return NOTIFY_DONE;
1423
1424 if (dev->type != ARPHRD_CAN)
1425 return NOTIFY_DONE;
1426
1427 switch (msg) {
1428
1429 case NETDEV_UNREGISTER:
1430 lock_sock(sk);
1431
1432 /* remove device specific receive entries */
1433 list_for_each_entry(op, &bo->rx_ops, list)
1434 if (op->rx_reg_dev == dev)
1435 bcm_rx_unreg(dev, op);
1436
1437 /* remove device reference, if this is our bound device */
1438 if (bo->bound && bo->ifindex == dev->ifindex) {
1439 bo->bound = 0;
1440 bo->ifindex = 0;
1441 notify_enodev = 1;
1442 }
1443
1444 release_sock(sk);
1445
1446 if (notify_enodev) {
1447 sk->sk_err = ENODEV;
1448 if (!sock_flag(sk, SOCK_DEAD))
1449 sk->sk_error_report(sk);
1450 }
1451 break;
1452
1453 case NETDEV_DOWN:
1454 if (bo->bound && bo->ifindex == dev->ifindex) {
1455 sk->sk_err = ENETDOWN;
1456 if (!sock_flag(sk, SOCK_DEAD))
1457 sk->sk_error_report(sk);
1458 }
1459 }
1460
1461 return NOTIFY_DONE;
1462}
1463
1464/*
1465 * initial settings for all BCM sockets to be set at socket creation time
1466 */
1467static int bcm_init(struct sock *sk)
1468{
1469 struct bcm_sock *bo = bcm_sk(sk);
1470
1471 bo->bound = 0;
1472 bo->ifindex = 0;
1473 bo->dropped_usr_msgs = 0;
1474 bo->bcm_proc_read = NULL;
1475
1476 INIT_LIST_HEAD(&bo->tx_ops);
1477 INIT_LIST_HEAD(&bo->rx_ops);
1478
1479 /* set notifier */
1480 bo->notifier.notifier_call = bcm_notifier;
1481
1482 register_netdevice_notifier(&bo->notifier);
1483
1484 return 0;
1485}
1486
1487/*
1488 * standard socket functions
1489 */
1490static int bcm_release(struct socket *sock)
1491{
1492 struct sock *sk = sock->sk;
1493 struct bcm_sock *bo;
1494 struct bcm_op *op, *next;
1495
1496 if (sk == NULL)
1497 return 0;
1498
1499 bo = bcm_sk(sk);
1500
1501 /* remove bcm_ops, timer, rx_unregister(), etc. */
1502
1503 unregister_netdevice_notifier(&bo->notifier);
1504
1505 lock_sock(sk);
1506
1507 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1508 bcm_remove_op(op);
1509
1510 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1511 /*
1512 * Don't care if we're bound or not (due to netdev problems)
1513 * can_rx_unregister() is always a save thing to do here.
1514 */
1515 if (op->ifindex) {
1516 /*
1517 * Only remove subscriptions that had not
1518 * been removed due to NETDEV_UNREGISTER
1519 * in bcm_notifier()
1520 */
1521 if (op->rx_reg_dev) {
1522 struct net_device *dev;
1523
1524 dev = dev_get_by_index(&init_net, op->ifindex);
1525 if (dev) {
1526 bcm_rx_unreg(dev, op);
1527 dev_put(dev);
1528 }
1529 }
1530 } else
1531 can_rx_unregister(NULL, op->can_id,
1532 REGMASK(op->can_id),
1533 bcm_rx_handler, op);
1534
1535 bcm_remove_op(op);
1536 }
1537
1538 /* remove procfs entry */
1539 if (proc_dir && bo->bcm_proc_read)
1540 remove_proc_entry(bo->procname, proc_dir);
1541
1542 /* remove device reference */
1543 if (bo->bound) {
1544 bo->bound = 0;
1545 bo->ifindex = 0;
1546 }
1547
1548 sock_orphan(sk);
1549 sock->sk = NULL;
1550
1551 release_sock(sk);
1552 sock_put(sk);
1553
1554 return 0;
1555}
1556
1557static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1558 int flags)
1559{
1560 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1561 struct sock *sk = sock->sk;
1562 struct bcm_sock *bo = bcm_sk(sk);
1563 int ret = 0;
1564
1565 if (len < sizeof(*addr))
1566 return -EINVAL;
1567
1568 lock_sock(sk);
1569
1570 if (bo->bound) {
1571 ret = -EISCONN;
1572 goto fail;
1573 }
1574
1575 /* bind a device to this socket */
1576 if (addr->can_ifindex) {
1577 struct net_device *dev;
1578
1579 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1580 if (!dev) {
1581 ret = -ENODEV;
1582 goto fail;
1583 }
1584 if (dev->type != ARPHRD_CAN) {
1585 dev_put(dev);
1586 ret = -ENODEV;
1587 goto fail;
1588 }
1589
1590 bo->ifindex = dev->ifindex;
1591 dev_put(dev);
1592
1593 } else {
1594 /* no interface reference for ifindex = 0 ('any' CAN device) */
1595 bo->ifindex = 0;
1596 }
1597
1598 if (proc_dir) {
1599 /* unique socket address as filename */
1600 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1601 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1602 proc_dir,
1603 &bcm_proc_fops, sk);
1604 if (!bo->bcm_proc_read) {
1605 ret = -ENOMEM;
1606 goto fail;
1607 }
1608 }
1609
1610 bo->bound = 1;
1611
1612fail:
1613 release_sock(sk);
1614
1615 return ret;
1616}
1617
1618static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1619 int flags)
1620{
1621 struct sock *sk = sock->sk;
1622 struct sk_buff *skb;
1623 int error = 0;
1624 int noblock;
1625 int err;
1626
1627 noblock = flags & MSG_DONTWAIT;
1628 flags &= ~MSG_DONTWAIT;
1629 skb = skb_recv_datagram(sk, flags, noblock, &error);
1630 if (!skb)
1631 return error;
1632
1633 if (skb->len < size)
1634 size = skb->len;
1635
1636 err = memcpy_to_msg(msg, skb->data, size);
1637 if (err < 0) {
1638 skb_free_datagram(sk, skb);
1639 return err;
1640 }
1641
1642 sock_recv_ts_and_drops(msg, sk, skb);
1643
1644 if (msg->msg_name) {
1645 __sockaddr_check_size(sizeof(struct sockaddr_can));
1646 msg->msg_namelen = sizeof(struct sockaddr_can);
1647 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1648 }
1649
1650 skb_free_datagram(sk, skb);
1651
1652 return size;
1653}
1654
1655static const struct proto_ops bcm_ops = {
1656 .family = PF_CAN,
1657 .release = bcm_release,
1658 .bind = sock_no_bind,
1659 .connect = bcm_connect,
1660 .socketpair = sock_no_socketpair,
1661 .accept = sock_no_accept,
1662 .getname = sock_no_getname,
1663 .poll = datagram_poll,
1664 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1665 .listen = sock_no_listen,
1666 .shutdown = sock_no_shutdown,
1667 .setsockopt = sock_no_setsockopt,
1668 .getsockopt = sock_no_getsockopt,
1669 .sendmsg = bcm_sendmsg,
1670 .recvmsg = bcm_recvmsg,
1671 .mmap = sock_no_mmap,
1672 .sendpage = sock_no_sendpage,
1673};
1674
1675static struct proto bcm_proto __read_mostly = {
1676 .name = "CAN_BCM",
1677 .owner = THIS_MODULE,
1678 .obj_size = sizeof(struct bcm_sock),
1679 .init = bcm_init,
1680};
1681
1682static const struct can_proto bcm_can_proto = {
1683 .type = SOCK_DGRAM,
1684 .protocol = CAN_BCM,
1685 .ops = &bcm_ops,
1686 .prot = &bcm_proto,
1687};
1688
1689static int __init bcm_module_init(void)
1690{
1691 int err;
1692
1693 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1694
1695 err = can_proto_register(&bcm_can_proto);
1696 if (err < 0) {
1697 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1698 return err;
1699 }
1700
1701 /* create /proc/net/can-bcm directory */
1702 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1703 return 0;
1704}
1705
1706static void __exit bcm_module_exit(void)
1707{
1708 can_proto_unregister(&bcm_can_proto);
1709
1710 if (proc_dir)
1711 remove_proc_entry("can-bcm", init_net.proc_net);
1712}
1713
1714module_init(bcm_module_init);
1715module_exit(bcm_module_exit);