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(secs: tv.tv_sec, nsecs: 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(p: result, q: dev->name);
198 else
199 strcpy(p: result, q: "???");
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(inode: m->file->f_inode);
210 struct bcm_sock *bo = bcm_sk(sk);
211 struct bcm_op *op;
212
213 seq_printf(m, fmt: ">>> socket %pK", sk->sk_socket);
214 seq_printf(m, fmt: " / sk %pK", sk);
215 seq_printf(m, fmt: " / bo %pK", bo);
216 seq_printf(m, fmt: " / dropped %lu", bo->dropped_usr_msgs);
217 seq_printf(m, fmt: " / bound %s", bcm_proc_getifname(net, result: ifname, ifindex: bo->ifindex));
218 seq_printf(m, fmt: " <<<\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, fmt: "rx_op: %03X %-5s ", op->can_id,
229 bcm_proc_getifname(net, result: ifname, ifindex: op->ifindex));
230
231 if (op->flags & CAN_FD_FRAME)
232 seq_printf(m, fmt: "(%u)", op->nframes);
233 else
234 seq_printf(m, fmt: "[%u]", op->nframes);
235
236 seq_printf(m, fmt: "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
237
238 if (op->kt_ival1)
239 seq_printf(m, fmt: "timeo=%lld ",
240 (long long)ktime_to_us(kt: op->kt_ival1));
241
242 if (op->kt_ival2)
243 seq_printf(m, fmt: "thr=%lld ",
244 (long long)ktime_to_us(kt: op->kt_ival2));
245
246 seq_printf(m, fmt: "# 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, fmt: "%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, fmt: "tx_op: %03X %s ", op->can_id,
258 bcm_proc_getifname(net, result: ifname, ifindex: op->ifindex));
259
260 if (op->flags & CAN_FD_FRAME)
261 seq_printf(m, fmt: "(%u) ", op->nframes);
262 else
263 seq_printf(m, fmt: "[%u] ", op->nframes);
264
265 if (op->kt_ival1)
266 seq_printf(m, fmt: "t1=%lld ",
267 (long long)ktime_to_us(kt: op->kt_ival1));
268
269 if (op->kt_ival2)
270 seq_printf(m, fmt: "t2=%lld ",
271 (long long)ktime_to_us(kt: op->kt_ival2));
272
273 seq_printf(m, fmt: "# sent %ld\n", op->frames_abs);
274 }
275 seq_putc(m, c: '\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(net: sock_net(sk: op->sk), ifindex: op->ifindex);
296 if (!dev) {
297 /* RFC: should this bcm_op remove itself here? */
298 return;
299 }
300
301 skb = alloc_skb(size: op->cfsiz + sizeof(struct can_skb_priv), priority: 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, data: cf, len: op->cfsiz);
310
311 /* send with loopback */
312 skb->dev = dev;
313 can_skb_set_owner(skb, sk: op->sk);
314 err = can_send(skb, loop: 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(size: sizeof(*head) + datalen, priority: gfp_any());
343 if (!skb)
344 return;
345
346 skb_put_data(skb, data: head, len: 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, data: frames, len: 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(timer: 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, hrt: &op->timer))
423 hrtimer_start_expires(timer: &op->timer, mode: 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, head: &msg_head, NULL, has_timestamp: 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, hrt: &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: &head, frames: data, has_timestamp: 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, data: lastdata);
509 return;
510 }
511
512 /* with active throttling timer we are just done here */
513 if (hrtimer_active(timer: &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(later: ktime_get(), earlier: op->kt_lastmsg) <
522 ktime_to_us(kt: op->kt_ival2)) {
523 /* do not send the saved data - only start throttle timer */
524 hrtimer_start(timer: &op->thrtimer,
525 ktime_add(op->kt_lastmsg, op->kt_ival2),
526 mode: 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, data: 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, lastdata: 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(cp: cf, offset: i) & get_u64(cp: rxdata, offset: i)) !=
562 (get_u64(cp: cf, offset: i) & get_u64(cp: lcf, offset: i))) {
563 bcm_rx_update_and_send(op, lastdata: 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, lastdata: 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(timer: &op->timer, tim: op->kt_ival1, mode: 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, head: &msg_head, NULL, has_timestamp: 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, data: 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, index: i);
643
644 } else {
645 /* for RX_FILTER_ID and simple filter */
646 updated += bcm_rx_do_flush(op, index: 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(timer: hrtimer, interval: 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(timer: &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, lastdata: op->last_frames, rxdata: 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, index: 0, rxdata: 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(cp: op->frames, offset: 0) & get_u64(cp: rxframe, offset: 0)) ==
740 (get_u64(cp: op->frames, offset: 0) &
741 get_u64(cp: op->frames + op->cfsiz * i, offset: 0))) {
742 bcm_rx_cmp_to_index(op, index: i, rxdata: 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(objp: op->frames);
776
777 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
778 kfree(objp: op->last_frames);
779
780 kfree(objp: op);
781}
782
783static void bcm_remove_op(struct bcm_op *op)
784{
785 hrtimer_cancel(timer: &op->timer);
786 hrtimer_cancel(timer: &op->thrtimer);
787
788 call_rcu(head: &op->rcu, func: 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(net: dev_net(dev), dev, can_id: op->can_id,
795 REGMASK(op->can_id), func: bcm_rx_handler, data: 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(net: sock_net(sk: op->sk),
834 ifindex: op->ifindex);
835 if (dev) {
836 bcm_rx_unreg(dev, op);
837 dev_put(dev);
838 }
839 }
840 } else
841 can_rx_unregister(net: sock_net(sk: op->sk), NULL,
842 can_id: op->can_id,
843 REGMASK(op->can_id),
844 func: bcm_rx_handler, data: op);
845
846 list_del(entry: &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(entry: &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, mh: 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, head: msg_head, frames: op->frames, has_timestamp: 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(ops: &bo->tx_ops, mh: 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(data: (u8 *)cf, msg, len: 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(n: msg_head->nframes,
973 size: op->cfsiz,
974 GFP_KERNEL);
975 if (!op->frames) {
976 kfree(objp: 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(data: (u8 *)cf, msg, len: 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(timer: &op->timer, CLOCK_MONOTONIC,
1015 mode: HRTIMER_MODE_REL_SOFT);
1016 op->timer.function = bcm_tx_timeout_handler;
1017
1018 /* currently unused in tx_ops */
1019 hrtimer_init(timer: &op->thrtimer, CLOCK_MONOTONIC,
1020 mode: HRTIMER_MODE_REL_SOFT);
1021
1022 /* add this bcm_op to the list of the tx_ops */
1023 list_add(new: &op->list, head: &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(tv: msg_head->ival1);
1046 op->kt_ival2 = bcm_timeval_to_ktime(tv: msg_head->ival2);
1047
1048 /* disable an active timer due to zero values? */
1049 if (!op->kt_ival1 && !op->kt_ival2)
1050 hrtimer_cancel(timer: &op->timer);
1051 }
1052
1053 if (op->flags & STARTTIMER) {
1054 hrtimer_cancel(timer: &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(objp: op->frames);
1073 kfree(objp: 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(ops: &bo->rx_ops, mh: 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(data: op->frames, msg,
1124 len: 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(n: msg_head->nframes,
1152 size: op->cfsiz,
1153 GFP_KERNEL);
1154 if (!op->frames) {
1155 kfree(objp: op);
1156 return -ENOMEM;
1157 }
1158
1159 /* create and init array for received CAN frames */
1160 op->last_frames = kcalloc(n: msg_head->nframes,
1161 size: op->cfsiz,
1162 GFP_KERNEL);
1163 if (!op->last_frames) {
1164 kfree(objp: op->frames);
1165 kfree(objp: 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(data: op->frames, msg,
1176 len: msg_head->nframes * op->cfsiz);
1177 if (err < 0) {
1178 if (op->frames != &op->sframe)
1179 kfree(objp: op->frames);
1180 if (op->last_frames != &op->last_sframe)
1181 kfree(objp: op->last_frames);
1182 kfree(objp: 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(timer: &op->timer, CLOCK_MONOTONIC,
1196 mode: HRTIMER_MODE_REL_SOFT);
1197 op->timer.function = bcm_rx_timeout_handler;
1198
1199 hrtimer_init(timer: &op->thrtimer, CLOCK_MONOTONIC,
1200 mode: 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(new: &op->list, head: &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(timer: &op->thrtimer);
1218 hrtimer_cancel(timer: &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(tv: msg_head->ival1);
1236 op->kt_ival2 = bcm_timeval_to_ktime(tv: msg_head->ival2);
1237
1238 /* disable an active timer due to zero value? */
1239 if (!op->kt_ival1)
1240 hrtimer_cancel(timer: &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(timer: &op->thrtimer);
1248 bcm_rx_thr_flush(op);
1249 }
1250
1251 if ((op->flags & STARTTIMER) && op->kt_ival1)
1252 hrtimer_start(timer: &op->timer, tim: op->kt_ival1,
1253 mode: 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(net: sock_net(sk), ifindex);
1262 if (dev) {
1263 err = can_rx_register(net: sock_net(sk), dev,
1264 can_id: op->can_id,
1265 REGMASK(op->can_id),
1266 func: bcm_rx_handler, data: op,
1267 ident: "bcm", sk);
1268
1269 op->rx_reg_dev = dev;
1270 dev_put(dev);
1271 }
1272
1273 } else
1274 err = can_rx_register(net: sock_net(sk), NULL, can_id: op->can_id,
1275 REGMASK(op->can_id),
1276 func: bcm_rx_handler, data: op, ident: "bcm", sk);
1277 if (err) {
1278 /* this bcm rx op is broken -> remove it */
1279 list_del(entry: &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(size: 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(data: skb_put(skb, len: cfsiz), msg, len: cfsiz);
1309 if (err < 0) {
1310 kfree_skb(skb);
1311 return err;
1312 }
1313
1314 dev = dev_get_by_index(net: 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, loop: 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(data: (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(net: 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_head, msg, ifindex, sk);
1398 break;
1399
1400 case RX_SETUP:
1401 ret = bcm_rx_setup(msg_head: &msg_head, msg, ifindex, sk);
1402 break;
1403
1404 case TX_DELETE:
1405 if (bcm_delete_tx_op(ops: &bo->tx_ops, mh: &msg_head, ifindex))
1406 ret = MHSIZ;
1407 else
1408 ret = -EINVAL;
1409 break;
1410
1411 case RX_DELETE:
1412 if (bcm_delete_rx_op(ops: &bo->rx_ops, mh: &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(ops: &bo->tx_ops, msg_head: &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(ops: &bo->rx_ops, msg_head: &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(net1: dev_net(dev), net2: 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 bo->bound = 0;
1474 bo->ifindex = 0;
1475 notify_enodev = 1;
1476 }
1477
1478 release_sock(sk);
1479
1480 if (notify_enodev) {
1481 sk->sk_err = ENODEV;
1482 if (!sock_flag(sk, flag: SOCK_DEAD))
1483 sk_error_report(sk);
1484 }
1485 break;
1486
1487 case NETDEV_DOWN:
1488 if (bo->bound && bo->ifindex == dev->ifindex) {
1489 sk->sk_err = ENETDOWN;
1490 if (!sock_flag(sk, flag: SOCK_DEAD))
1491 sk_error_report(sk);
1492 }
1493 }
1494}
1495
1496static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1497 void *ptr)
1498{
1499 struct net_device *dev = netdev_notifier_info_to_dev(info: ptr);
1500
1501 if (dev->type != ARPHRD_CAN)
1502 return NOTIFY_DONE;
1503 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1504 return NOTIFY_DONE;
1505 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1506 return NOTIFY_DONE;
1507
1508 spin_lock(lock: &bcm_notifier_lock);
1509 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1510 spin_unlock(lock: &bcm_notifier_lock);
1511 bcm_notify(bo: bcm_busy_notifier, msg, dev);
1512 spin_lock(lock: &bcm_notifier_lock);
1513 }
1514 bcm_busy_notifier = NULL;
1515 spin_unlock(lock: &bcm_notifier_lock);
1516 return NOTIFY_DONE;
1517}
1518
1519/*
1520 * initial settings for all BCM sockets to be set at socket creation time
1521 */
1522static int bcm_init(struct sock *sk)
1523{
1524 struct bcm_sock *bo = bcm_sk(sk);
1525
1526 bo->bound = 0;
1527 bo->ifindex = 0;
1528 bo->dropped_usr_msgs = 0;
1529 bo->bcm_proc_read = NULL;
1530
1531 INIT_LIST_HEAD(list: &bo->tx_ops);
1532 INIT_LIST_HEAD(list: &bo->rx_ops);
1533
1534 /* set notifier */
1535 spin_lock(lock: &bcm_notifier_lock);
1536 list_add_tail(new: &bo->notifier, head: &bcm_notifier_list);
1537 spin_unlock(lock: &bcm_notifier_lock);
1538
1539 return 0;
1540}
1541
1542/*
1543 * standard socket functions
1544 */
1545static int bcm_release(struct socket *sock)
1546{
1547 struct sock *sk = sock->sk;
1548 struct net *net;
1549 struct bcm_sock *bo;
1550 struct bcm_op *op, *next;
1551
1552 if (!sk)
1553 return 0;
1554
1555 net = sock_net(sk);
1556 bo = bcm_sk(sk);
1557
1558 /* remove bcm_ops, timer, rx_unregister(), etc. */
1559
1560 spin_lock(lock: &bcm_notifier_lock);
1561 while (bcm_busy_notifier == bo) {
1562 spin_unlock(lock: &bcm_notifier_lock);
1563 schedule_timeout_uninterruptible(timeout: 1);
1564 spin_lock(lock: &bcm_notifier_lock);
1565 }
1566 list_del(entry: &bo->notifier);
1567 spin_unlock(lock: &bcm_notifier_lock);
1568
1569 lock_sock(sk);
1570
1571#if IS_ENABLED(CONFIG_PROC_FS)
1572 /* remove procfs entry */
1573 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1574 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1575#endif /* CONFIG_PROC_FS */
1576
1577 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1578 bcm_remove_op(op);
1579
1580 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1581 /*
1582 * Don't care if we're bound or not (due to netdev problems)
1583 * can_rx_unregister() is always a save thing to do here.
1584 */
1585 if (op->ifindex) {
1586 /*
1587 * Only remove subscriptions that had not
1588 * been removed due to NETDEV_UNREGISTER
1589 * in bcm_notifier()
1590 */
1591 if (op->rx_reg_dev) {
1592 struct net_device *dev;
1593
1594 dev = dev_get_by_index(net, ifindex: op->ifindex);
1595 if (dev) {
1596 bcm_rx_unreg(dev, op);
1597 dev_put(dev);
1598 }
1599 }
1600 } else
1601 can_rx_unregister(net, NULL, can_id: op->can_id,
1602 REGMASK(op->can_id),
1603 func: bcm_rx_handler, data: op);
1604
1605 }
1606
1607 synchronize_rcu();
1608
1609 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1610 bcm_remove_op(op);
1611
1612 /* remove device reference */
1613 if (bo->bound) {
1614 bo->bound = 0;
1615 bo->ifindex = 0;
1616 }
1617
1618 sock_orphan(sk);
1619 sock->sk = NULL;
1620
1621 release_sock(sk);
1622 sock_put(sk);
1623
1624 return 0;
1625}
1626
1627static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1628 int flags)
1629{
1630 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1631 struct sock *sk = sock->sk;
1632 struct bcm_sock *bo = bcm_sk(sk);
1633 struct net *net = sock_net(sk);
1634 int ret = 0;
1635
1636 if (len < BCM_MIN_NAMELEN)
1637 return -EINVAL;
1638
1639 lock_sock(sk);
1640
1641 if (bo->bound) {
1642 ret = -EISCONN;
1643 goto fail;
1644 }
1645
1646 /* bind a device to this socket */
1647 if (addr->can_ifindex) {
1648 struct net_device *dev;
1649
1650 dev = dev_get_by_index(net, ifindex: addr->can_ifindex);
1651 if (!dev) {
1652 ret = -ENODEV;
1653 goto fail;
1654 }
1655 if (dev->type != ARPHRD_CAN) {
1656 dev_put(dev);
1657 ret = -ENODEV;
1658 goto fail;
1659 }
1660
1661 bo->ifindex = dev->ifindex;
1662 dev_put(dev);
1663
1664 } else {
1665 /* no interface reference for ifindex = 0 ('any' CAN device) */
1666 bo->ifindex = 0;
1667 }
1668
1669#if IS_ENABLED(CONFIG_PROC_FS)
1670 if (net->can.bcmproc_dir) {
1671 /* unique socket address as filename */
1672 sprintf(buf: bo->procname, fmt: "%lu", sock_i_ino(sk));
1673 bo->bcm_proc_read = proc_create_net_single(name: bo->procname, mode: 0644,
1674 parent: net->can.bcmproc_dir,
1675 show: bcm_proc_show, data: sk);
1676 if (!bo->bcm_proc_read) {
1677 ret = -ENOMEM;
1678 goto fail;
1679 }
1680 }
1681#endif /* CONFIG_PROC_FS */
1682
1683 bo->bound = 1;
1684
1685fail:
1686 release_sock(sk);
1687
1688 return ret;
1689}
1690
1691static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1692 int flags)
1693{
1694 struct sock *sk = sock->sk;
1695 struct sk_buff *skb;
1696 int error = 0;
1697 int err;
1698
1699 skb = skb_recv_datagram(sk, flags, err: &error);
1700 if (!skb)
1701 return error;
1702
1703 if (skb->len < size)
1704 size = skb->len;
1705
1706 err = memcpy_to_msg(msg, data: skb->data, len: size);
1707 if (err < 0) {
1708 skb_free_datagram(sk, skb);
1709 return err;
1710 }
1711
1712 sock_recv_cmsgs(msg, sk, skb);
1713
1714 if (msg->msg_name) {
1715 __sockaddr_check_size(BCM_MIN_NAMELEN);
1716 msg->msg_namelen = BCM_MIN_NAMELEN;
1717 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1718 }
1719
1720 /* assign the flags that have been recorded in bcm_send_to_user() */
1721 msg->msg_flags |= *(bcm_flags(skb));
1722
1723 skb_free_datagram(sk, skb);
1724
1725 return size;
1726}
1727
1728static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1729 unsigned long arg)
1730{
1731 /* no ioctls for socket layer -> hand it down to NIC layer */
1732 return -ENOIOCTLCMD;
1733}
1734
1735static const struct proto_ops bcm_ops = {
1736 .family = PF_CAN,
1737 .release = bcm_release,
1738 .bind = sock_no_bind,
1739 .connect = bcm_connect,
1740 .socketpair = sock_no_socketpair,
1741 .accept = sock_no_accept,
1742 .getname = sock_no_getname,
1743 .poll = datagram_poll,
1744 .ioctl = bcm_sock_no_ioctlcmd,
1745 .gettstamp = sock_gettstamp,
1746 .listen = sock_no_listen,
1747 .shutdown = sock_no_shutdown,
1748 .sendmsg = bcm_sendmsg,
1749 .recvmsg = bcm_recvmsg,
1750 .mmap = sock_no_mmap,
1751};
1752
1753static struct proto bcm_proto __read_mostly = {
1754 .name = "CAN_BCM",
1755 .owner = THIS_MODULE,
1756 .obj_size = sizeof(struct bcm_sock),
1757 .init = bcm_init,
1758};
1759
1760static const struct can_proto bcm_can_proto = {
1761 .type = SOCK_DGRAM,
1762 .protocol = CAN_BCM,
1763 .ops = &bcm_ops,
1764 .prot = &bcm_proto,
1765};
1766
1767static int canbcm_pernet_init(struct net *net)
1768{
1769#if IS_ENABLED(CONFIG_PROC_FS)
1770 /* create /proc/net/can-bcm directory */
1771 net->can.bcmproc_dir = proc_net_mkdir(net, name: "can-bcm", parent: net->proc_net);
1772#endif /* CONFIG_PROC_FS */
1773
1774 return 0;
1775}
1776
1777static void canbcm_pernet_exit(struct net *net)
1778{
1779#if IS_ENABLED(CONFIG_PROC_FS)
1780 /* remove /proc/net/can-bcm directory */
1781 if (net->can.bcmproc_dir)
1782 remove_proc_entry("can-bcm", net->proc_net);
1783#endif /* CONFIG_PROC_FS */
1784}
1785
1786static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1787 .init = canbcm_pernet_init,
1788 .exit = canbcm_pernet_exit,
1789};
1790
1791static struct notifier_block canbcm_notifier = {
1792 .notifier_call = bcm_notifier
1793};
1794
1795static int __init bcm_module_init(void)
1796{
1797 int err;
1798
1799 pr_info("can: broadcast manager protocol\n");
1800
1801 err = register_pernet_subsys(&canbcm_pernet_ops);
1802 if (err)
1803 return err;
1804
1805 err = register_netdevice_notifier(nb: &canbcm_notifier);
1806 if (err)
1807 goto register_notifier_failed;
1808
1809 err = can_proto_register(cp: &bcm_can_proto);
1810 if (err < 0) {
1811 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1812 goto register_proto_failed;
1813 }
1814
1815 return 0;
1816
1817register_proto_failed:
1818 unregister_netdevice_notifier(nb: &canbcm_notifier);
1819register_notifier_failed:
1820 unregister_pernet_subsys(&canbcm_pernet_ops);
1821 return err;
1822}
1823
1824static void __exit bcm_module_exit(void)
1825{
1826 can_proto_unregister(cp: &bcm_can_proto);
1827 unregister_netdevice_notifier(nb: &canbcm_notifier);
1828 unregister_pernet_subsys(&canbcm_pernet_ops);
1829}
1830
1831module_init(bcm_module_init);
1832module_exit(bcm_module_exit);
1833

source code of linux/net/can/bcm.c