2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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.
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.
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
40 * Send feedback to <socketcan-users@lists.berlios.de>
44 #include <linux/module.h>
45 #include <linux/version.h>
46 #include <linux/init.h>
47 #include <linux/hrtimer.h>
48 #include <linux/list.h>
49 #include <linux/proc_fs.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/bcm.h>
60 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
61 #include <net/net_namespace.h>
63 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
67 #include <linux/can/version.h> /* for RCSID. Removed by mkpatch script */
70 /* use of last_frames[index].can_dlc */
71 #define RX_RECV 0x40 /* received data for this element */
72 #define RX_THR 0x80 /* element not been sent due to throttle feature */
73 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
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))
80 #define CAN_BCM_VERSION CAN_VERSION
81 static __initdata const char banner[] = KERN_INFO
82 "can: broadcast manager protocol (rev " CAN_BCM_VERSION ")\n";
84 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
85 MODULE_LICENSE("Dual BSD/GPL");
86 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
88 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
89 #error This code only supports Kernel versions 2.6.22+
90 #error For older 2.6 Kernels please use bcm-prior-2-6-22.c instead of bcm.c
93 /* easy access to can_frame payload */
94 static inline u64 GET_U64(const struct can_frame *cp)
96 return *(u64 *)cp->data;
100 struct list_head list;
104 unsigned long frames_abs, frames_filtered;
105 struct timeval ival1, ival2;
106 struct hrtimer timer, thrtimer;
107 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
112 struct can_frame *frames;
113 struct can_frame *last_frames;
114 struct can_frame sframe;
115 struct can_frame last_sframe;
117 struct net_device *rx_reg_dev;
120 static struct proc_dir_entry *proc_dir;
126 struct notifier_block notifier;
127 struct list_head rx_ops;
128 struct list_head tx_ops;
129 unsigned long dropped_usr_msgs;
130 struct proc_dir_entry *bcm_proc_read;
131 char procname [9]; /* pointer printed in ASCII with \0 */
134 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
136 return (struct bcm_sock *)sk;
139 #define CFSIZ sizeof(struct can_frame)
140 #define OPSIZ sizeof(struct bcm_op)
141 #define MHSIZ sizeof(struct bcm_msg_head)
146 static char *bcm_proc_getifname(int ifindex)
148 struct net_device *dev;
153 /* no usage counting */
154 dev = __dev_get_by_index(&init_net, ifindex);
161 static int bcm_read_proc(char *page, char **start, off_t off,
162 int count, int *eof, void *data)
165 struct sock *sk = (struct sock *)data;
166 struct bcm_sock *bo = bcm_sk(sk);
169 len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p",
171 len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk);
172 len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo);
173 len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu",
174 bo->dropped_usr_msgs);
175 len += snprintf(page + len, PAGE_SIZE - len, " / bound %s",
176 bcm_proc_getifname(bo->ifindex));
177 len += snprintf(page + len, PAGE_SIZE - len, " <<<\n");
179 list_for_each_entry(op, &bo->rx_ops, list) {
181 unsigned long reduction;
183 /* print only active entries & prevent division by zero */
187 len += snprintf(page + len, PAGE_SIZE - len,
189 op->can_id, bcm_proc_getifname(op->ifindex));
190 len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ",
192 (op->flags & RX_CHECK_DLC)?'d':' ');
193 if (op->kt_ival1.tv64)
194 len += snprintf(page + len, PAGE_SIZE - len,
197 ktime_to_us(op->kt_ival1));
199 if (op->kt_ival2.tv64)
200 len += snprintf(page + len, PAGE_SIZE - len,
203 ktime_to_us(op->kt_ival2));
205 len += snprintf(page + len, PAGE_SIZE - len,
206 "# recv %ld (%ld) => reduction: ",
207 op->frames_filtered, op->frames_abs);
209 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
211 len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n",
212 (reduction == 100)?"near ":"", reduction);
214 if (len > PAGE_SIZE - 200) {
215 /* mark output cut off */
216 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
221 list_for_each_entry(op, &bo->tx_ops, list) {
223 len += snprintf(page + len, PAGE_SIZE - len,
224 "tx_op: %03X %s [%d] ",
225 op->can_id, bcm_proc_getifname(op->ifindex),
228 if (op->kt_ival1.tv64)
229 len += snprintf(page + len, PAGE_SIZE - len, "t1=%lld ",
230 (long long) ktime_to_us(op->kt_ival1));
232 if (op->kt_ival2.tv64)
233 len += snprintf(page + len, PAGE_SIZE - len, "t2=%lld ",
234 (long long) ktime_to_us(op->kt_ival2));
236 len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n",
239 if (len > PAGE_SIZE - 100) {
240 /* mark output cut off */
241 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
246 len += snprintf(page + len, PAGE_SIZE - len, "\n");
253 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
254 * of the given bcm tx op
256 static void bcm_can_tx(struct bcm_op *op)
259 struct net_device *dev;
260 struct can_frame *cf = &op->frames[op->currframe];
262 /* no target device? => exit */
266 dev = dev_get_by_index(&init_net, op->ifindex);
268 /* RFC: should this bcm_op remove itself here? */
272 skb = alloc_skb(CFSIZ, gfp_any());
276 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
278 /* send with loopback */
283 /* update statistics */
287 /* reached last frame? */
288 if (op->currframe >= op->nframes)
295 * bcm_send_to_user - send a BCM message to the userspace
296 * (consisting of bcm_msg_head + x CAN frames)
298 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
299 struct can_frame *frames, int has_timestamp)
302 struct can_frame *firstframe;
303 struct sockaddr_can *addr;
304 struct sock *sk = op->sk;
305 int datalen = head->nframes * CFSIZ;
308 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
312 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
315 /* can_frames starting here */
316 firstframe = (struct can_frame *)skb_tail_pointer(skb);
318 memcpy(skb_put(skb, datalen), frames, datalen);
321 * the BCM uses the can_dlc-element of the can_frame
322 * structure for internal purposes. This is only
323 * relevant for updates that are generated by the
324 * BCM, where nframes is 1
326 if (head->nframes == 1)
327 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
331 /* restore rx timestamp */
332 skb->tstamp = op->rx_stamp;
336 * Put the datagram to the queue so that bcm_recvmsg() can
337 * get it from there. We need to pass the interface index to
338 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
339 * containing the interface index.
342 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
343 addr = (struct sockaddr_can *)skb->cb;
344 memset(addr, 0, sizeof(*addr));
345 addr->can_family = AF_CAN;
346 addr->can_ifindex = op->rx_ifindex;
348 err = sock_queue_rcv_skb(sk, skb);
350 struct bcm_sock *bo = bcm_sk(sk);
353 /* don't care about overflows in this statistic */
354 bo->dropped_usr_msgs++;
359 * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
361 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
363 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
364 enum hrtimer_restart ret = HRTIMER_NORESTART;
366 if (op->kt_ival1.tv64 && (op->count > 0)) {
369 if (!op->count && (op->flags & TX_COUNTEVT)) {
370 struct bcm_msg_head msg_head;
372 /* create notification to user */
373 msg_head.opcode = TX_EXPIRED;
374 msg_head.flags = op->flags;
375 msg_head.count = op->count;
376 msg_head.ival1 = op->ival1;
377 msg_head.ival2 = op->ival2;
378 msg_head.can_id = op->can_id;
379 msg_head.nframes = 0;
381 bcm_send_to_user(op, &msg_head, NULL, 0);
385 if (op->kt_ival1.tv64 && (op->count > 0)) {
387 /* send (next) frame */
389 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival1);
390 ret = HRTIMER_RESTART;
393 if (op->kt_ival2.tv64) {
395 /* send (next) frame */
397 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
398 ret = HRTIMER_RESTART;
406 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
408 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
410 struct bcm_msg_head head;
412 /* update statistics */
413 op->frames_filtered++;
415 /* prevent statistics overflow */
416 if (op->frames_filtered > ULONG_MAX/100)
417 op->frames_filtered = op->frames_abs = 0;
419 head.opcode = RX_CHANGED;
420 head.flags = op->flags;
421 head.count = op->count;
422 head.ival1 = op->ival1;
423 head.ival2 = op->ival2;
424 head.can_id = op->can_id;
427 bcm_send_to_user(op, &head, data, 1);
430 #if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,25)
431 /* is part of linux/hrtimer.h since 2.6.26 */
432 static inline int hrtimer_callback_running(struct hrtimer *timer)
434 return timer->state & HRTIMER_STATE_CALLBACK;
437 #if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,22)
438 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
440 return ktime_to_us(ktime_sub(later, earlier));
444 * bcm_rx_update_and_send - process a detected relevant receive content change
445 * 1. update the last received data
446 * 2. send a notification to the user (if possible)
448 static void bcm_rx_update_and_send(struct bcm_op *op,
449 struct can_frame *lastdata,
450 struct can_frame *rxdata)
452 memcpy(lastdata, rxdata, CFSIZ);
455 lastdata->can_dlc |= RX_RECV;
457 /* throtteling mode inactive OR data update already on the run ? */
458 if (!op->kt_ival2.tv64 || hrtimer_callback_running(&op->thrtimer)) {
459 /* send RX_CHANGED to the user immediately */
460 bcm_rx_changed(op, rxdata);
464 if (hrtimer_active(&op->thrtimer)) {
465 /* mark as 'throttled' */
466 lastdata->can_dlc |= RX_THR;
470 if (!op->kt_lastmsg.tv64) {
471 /* send first RX_CHANGED to the user immediately */
472 bcm_rx_changed(op, rxdata);
473 op->kt_lastmsg = ktime_get();
477 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
478 ktime_to_us(op->kt_ival2)) {
479 /* mark as 'throttled' and start timer */
480 lastdata->can_dlc |= RX_THR;
481 hrtimer_start(&op->thrtimer,
482 ktime_add(op->kt_lastmsg, op->kt_ival2),
487 /* the gap was that big, that throttling was not needed here */
488 bcm_rx_changed(op, rxdata);
489 op->kt_lastmsg = ktime_get();
493 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
494 * received data stored in op->last_frames[]
496 static void bcm_rx_cmp_to_index(struct bcm_op *op, int index,
497 struct can_frame *rxdata)
500 * no one uses the MSBs of can_dlc for comparation,
501 * so we use it here to detect the first time of reception
504 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
505 /* received data for the first time => send update to user */
506 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
510 /* do a real check in can_frame data section */
512 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
513 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
514 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
518 if (op->flags & RX_CHECK_DLC) {
519 /* do a real check in can_frame dlc */
520 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
522 bcm_rx_update_and_send(op, &op->last_frames[index],
530 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
532 static void bcm_rx_starttimer(struct bcm_op *op)
534 if (op->flags & RX_NO_AUTOTIMER)
537 if (op->kt_ival1.tv64)
538 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
542 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
544 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
546 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
547 struct bcm_msg_head msg_head;
549 msg_head.opcode = RX_TIMEOUT;
550 msg_head.flags = op->flags;
551 msg_head.count = op->count;
552 msg_head.ival1 = op->ival1;
553 msg_head.ival2 = op->ival2;
554 msg_head.can_id = op->can_id;
555 msg_head.nframes = 0;
557 bcm_send_to_user(op, &msg_head, NULL, 0);
559 /* no restart of the timer is done here! */
561 /* if user wants to be informed, when cyclic CAN-Messages come back */
562 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
563 /* clear received can_frames to indicate 'nothing received' */
564 memset(op->last_frames, 0, op->nframes * CFSIZ);
567 return HRTIMER_NORESTART;
571 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
573 static int bcm_rx_thr_flush(struct bcm_op *op)
577 if (op->nframes > 1) {
580 /* for MUX filter we start at index 1 */
581 for (i = 1; i < op->nframes; i++) {
582 if ((op->last_frames) &&
583 (op->last_frames[i].can_dlc & RX_THR)) {
584 op->last_frames[i].can_dlc &= ~RX_THR;
585 bcm_rx_changed(op, &op->last_frames[i]);
591 /* for RX_FILTER_ID and simple filter */
592 if (op->last_frames && (op->last_frames[0].can_dlc & RX_THR)) {
593 op->last_frames[0].can_dlc &= ~RX_THR;
594 bcm_rx_changed(op, &op->last_frames[0]);
603 * bcm_rx_thr_handler - the time for blocked content updates is over now:
604 * Check for throttled data and send it to the userspace
606 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
608 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
610 if (bcm_rx_thr_flush(op)) {
611 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
612 return HRTIMER_RESTART;
614 /* rearm throttle handling */
615 op->kt_lastmsg = ktime_set(0, 0);
616 return HRTIMER_NORESTART;
621 * bcm_rx_handler - handle a CAN frame receiption
623 static void bcm_rx_handler(struct sk_buff *skb, void *data)
625 struct bcm_op *op = (struct bcm_op *)data;
626 struct can_frame rxframe;
629 /* disable timeout */
630 hrtimer_cancel(&op->timer);
632 if (skb->len == sizeof(rxframe)) {
633 memcpy(&rxframe, skb->data, sizeof(rxframe));
634 /* save rx timestamp */
635 op->rx_stamp = skb->tstamp;
636 /* save originator for recvfrom() */
637 op->rx_ifindex = skb->dev->ifindex;
638 /* update statistics */
647 if (op->can_id != rxframe.can_id)
650 if (op->flags & RX_RTR_FRAME) {
651 /* send reply for RTR-request (placed in op->frames[0]) */
656 if (op->flags & RX_FILTER_ID) {
657 /* the easiest case */
658 bcm_rx_update_and_send(op, &op->last_frames[0], &rxframe);
659 bcm_rx_starttimer(op);
663 if (op->nframes == 1) {
664 /* simple compare with index 0 */
665 bcm_rx_cmp_to_index(op, 0, &rxframe);
666 bcm_rx_starttimer(op);
670 if (op->nframes > 1) {
674 * find the first multiplex mask that fits.
675 * Remark: The MUX-mask is stored in index 0
678 for (i = 1; i < op->nframes; i++) {
679 if ((GET_U64(&op->frames[0]) & GET_U64(&rxframe)) ==
680 (GET_U64(&op->frames[0]) &
681 GET_U64(&op->frames[i]))) {
682 bcm_rx_cmp_to_index(op, i, &rxframe);
686 bcm_rx_starttimer(op);
691 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
693 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
698 list_for_each_entry(op, ops, list) {
699 if ((op->can_id == can_id) && (op->ifindex == ifindex))
706 static void bcm_remove_op(struct bcm_op *op)
708 hrtimer_cancel(&op->timer);
709 hrtimer_cancel(&op->thrtimer);
711 if ((op->frames) && (op->frames != &op->sframe))
714 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
715 kfree(op->last_frames);
722 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
724 if (op->rx_reg_dev == dev) {
725 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
728 /* mark as removed subscription */
729 op->rx_reg_dev = NULL;
731 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
732 "mismatch %p %p\n", op->rx_reg_dev, dev);
736 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
738 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
740 struct bcm_op *op, *n;
742 list_for_each_entry_safe(op, n, ops, list) {
743 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
746 * Don't care if we're bound or not (due to netdev
747 * problems) can_rx_unregister() is always a save
752 * Only remove subscriptions that had not
753 * been removed due to NETDEV_UNREGISTER
756 if (op->rx_reg_dev) {
757 struct net_device *dev;
759 dev = dev_get_by_index(&init_net,
762 bcm_rx_unreg(dev, op);
767 can_rx_unregister(NULL, op->can_id,
777 return 0; /* not found */
781 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
783 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
785 struct bcm_op *op, *n;
787 list_for_each_entry_safe(op, n, ops, list) {
788 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
795 return 0; /* not found */
799 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
801 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
804 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
809 /* put current values into msg_head */
810 msg_head->flags = op->flags;
811 msg_head->count = op->count;
812 msg_head->ival1 = op->ival1;
813 msg_head->ival2 = op->ival2;
814 msg_head->nframes = op->nframes;
816 bcm_send_to_user(op, msg_head, op->frames, 0);
822 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
824 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
825 int ifindex, struct sock *sk)
827 struct bcm_sock *bo = bcm_sk(sk);
831 /* we need a real device to send frames */
835 /* we need at least one can_frame */
836 if (msg_head->nframes < 1)
839 /* check the given can_id */
840 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
843 /* update existing BCM operation */
846 * Do we need more space for the can_frames than currently
847 * allocated? -> This is a _really_ unusual use-case and
848 * therefore (complexity / locking) it is not supported.
850 if (msg_head->nframes > op->nframes)
853 /* update can_frames content */
854 for (i = 0; i < msg_head->nframes; i++) {
855 err = memcpy_fromiovec((u8 *)&op->frames[i],
856 msg->msg_iov, CFSIZ);
858 if (op->frames[i].can_dlc > 8)
864 if (msg_head->flags & TX_CP_CAN_ID) {
865 /* copy can_id into frame */
866 op->frames[i].can_id = msg_head->can_id;
871 /* insert new BCM operation for the given can_id */
873 op = kzalloc(OPSIZ, GFP_KERNEL);
877 op->can_id = msg_head->can_id;
879 /* create array for can_frames and copy the data */
880 if (msg_head->nframes > 1) {
881 op->frames = kmalloc(msg_head->nframes * CFSIZ,
888 op->frames = &op->sframe;
890 for (i = 0; i < msg_head->nframes; i++) {
891 err = memcpy_fromiovec((u8 *)&op->frames[i],
892 msg->msg_iov, CFSIZ);
894 if (op->frames[i].can_dlc > 8)
898 if (op->frames != &op->sframe)
904 if (msg_head->flags & TX_CP_CAN_ID) {
905 /* copy can_id into frame */
906 op->frames[i].can_id = msg_head->can_id;
910 /* tx_ops never compare with previous received messages */
911 op->last_frames = NULL;
913 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
915 op->ifindex = ifindex;
917 /* initialize uninitialized (kzalloc) structure */
918 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
919 op->timer.function = bcm_tx_timeout_handler;
921 /* currently unused in tx_ops */
922 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
924 /* add this bcm_op to the list of the tx_ops */
925 list_add(&op->list, &bo->tx_ops);
927 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
929 if (op->nframes != msg_head->nframes) {
930 op->nframes = msg_head->nframes;
931 /* start multiple frame transmission with index 0 */
937 op->flags = msg_head->flags;
939 if (op->flags & TX_RESET_MULTI_IDX) {
940 /* start multiple frame transmission with index 0 */
944 if (op->flags & SETTIMER) {
945 /* set timer values */
946 op->count = msg_head->count;
947 op->ival1 = msg_head->ival1;
948 op->ival2 = msg_head->ival2;
949 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
950 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
952 /* disable an active timer due to zero values? */
953 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
954 hrtimer_cancel(&op->timer);
957 if ((op->flags & STARTTIMER) &&
958 ((op->kt_ival1.tv64 && op->count) || op->kt_ival2.tv64)) {
960 /* spec: send can_frame when starting timer */
961 op->flags |= TX_ANNOUNCE;
963 if (op->kt_ival1.tv64 && (op->count > 0)) {
964 /* op->count-- is done in bcm_tx_timeout_handler */
965 hrtimer_start(&op->timer, op->kt_ival1,
968 hrtimer_start(&op->timer, op->kt_ival2,
972 if (op->flags & TX_ANNOUNCE)
975 return msg_head->nframes * CFSIZ + MHSIZ;
979 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
981 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
982 int ifindex, struct sock *sk)
984 struct bcm_sock *bo = bcm_sk(sk);
989 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
990 /* be robust against wrong usage ... */
991 msg_head->flags |= RX_FILTER_ID;
992 /* ignore trailing garbage */
993 msg_head->nframes = 0;
996 if ((msg_head->flags & RX_RTR_FRAME) &&
997 ((msg_head->nframes != 1) ||
998 (!(msg_head->can_id & CAN_RTR_FLAG))))
1001 /* check the given can_id */
1002 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1004 /* update existing BCM operation */
1007 * Do we need more space for the can_frames than currently
1008 * allocated? -> This is a _really_ unusual use-case and
1009 * therefore (complexity / locking) it is not supported.
1011 if (msg_head->nframes > op->nframes)
1014 if (msg_head->nframes) {
1015 /* update can_frames content */
1016 err = memcpy_fromiovec((u8 *)op->frames,
1018 msg_head->nframes * CFSIZ);
1022 /* clear last_frames to indicate 'nothing received' */
1023 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1026 op->nframes = msg_head->nframes;
1028 /* Only an update -> do not call can_rx_register() */
1032 /* insert new BCM operation for the given can_id */
1033 op = kzalloc(OPSIZ, GFP_KERNEL);
1037 op->can_id = msg_head->can_id;
1038 op->nframes = msg_head->nframes;
1040 if (msg_head->nframes > 1) {
1041 /* create array for can_frames and copy the data */
1042 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1049 /* create and init array for received can_frames */
1050 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1052 if (!op->last_frames) {
1059 op->frames = &op->sframe;
1060 op->last_frames = &op->last_sframe;
1063 if (msg_head->nframes) {
1064 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1065 msg_head->nframes * CFSIZ);
1067 if (op->frames != &op->sframe)
1069 if (op->last_frames != &op->last_sframe)
1070 kfree(op->last_frames);
1076 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1078 op->ifindex = ifindex;
1080 /* initialize uninitialized (kzalloc) structure */
1081 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1082 op->timer.function = bcm_rx_timeout_handler;
1084 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1085 op->thrtimer.function = bcm_rx_thr_handler;
1087 /* add this bcm_op to the list of the rx_ops */
1088 list_add(&op->list, &bo->rx_ops);
1090 /* call can_rx_register() */
1093 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1096 op->flags = msg_head->flags;
1098 if (op->flags & RX_RTR_FRAME) {
1100 /* no timers in RTR-mode */
1101 hrtimer_cancel(&op->thrtimer);
1102 hrtimer_cancel(&op->timer);
1105 * funny feature in RX(!)_SETUP only for RTR-mode:
1106 * copy can_id into frame BUT without RTR-flag to
1107 * prevent a full-load-loopback-test ... ;-]
1109 if ((op->flags & TX_CP_CAN_ID) ||
1110 (op->frames[0].can_id == op->can_id))
1111 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1114 if (op->flags & SETTIMER) {
1116 /* set timer value */
1117 op->ival1 = msg_head->ival1;
1118 op->ival2 = msg_head->ival2;
1119 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1120 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1122 /* disable an active timer due to zero value? */
1123 if (!op->kt_ival1.tv64)
1124 hrtimer_cancel(&op->timer);
1127 * In any case cancel the throttle timer, flush
1128 * potentially blocked msgs and reset throttle handling
1130 op->kt_lastmsg = ktime_set(0, 0);
1131 hrtimer_cancel(&op->thrtimer);
1132 bcm_rx_thr_flush(op);
1135 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1136 hrtimer_start(&op->timer, op->kt_ival1,
1140 /* now we can register for can_ids, if we added a new bcm_op */
1141 if (do_rx_register) {
1143 struct net_device *dev;
1145 dev = dev_get_by_index(&init_net, ifindex);
1147 err = can_rx_register(dev, op->can_id,
1148 REGMASK(op->can_id),
1152 op->rx_reg_dev = dev;
1157 err = can_rx_register(NULL, op->can_id,
1158 REGMASK(op->can_id),
1159 bcm_rx_handler, op, "bcm");
1161 /* this bcm rx op is broken -> remove it */
1162 list_del(&op->list);
1168 return msg_head->nframes * CFSIZ + MHSIZ;
1172 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1174 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1176 struct sk_buff *skb;
1177 struct net_device *dev;
1180 /* we need a real device to send frames */
1184 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1189 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1195 dev = dev_get_by_index(&init_net, ifindex);
1203 err = can_send(skb, 1); /* send with loopback */
1209 return CFSIZ + MHSIZ;
1213 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1215 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1216 struct msghdr *msg, size_t size)
1218 struct sock *sk = sock->sk;
1219 struct bcm_sock *bo = bcm_sk(sk);
1220 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1221 struct bcm_msg_head msg_head;
1222 int ret; /* read bytes or error codes as return value */
1227 /* check for valid message length from userspace */
1228 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1231 /* check for alternative ifindex for this bcm_op */
1233 if (!ifindex && msg->msg_name) {
1234 /* no bound device as default => check msg_name */
1235 struct sockaddr_can *addr =
1236 (struct sockaddr_can *)msg->msg_name;
1238 if (addr->can_family != AF_CAN)
1241 /* ifindex from sendto() */
1242 ifindex = addr->can_ifindex;
1245 struct net_device *dev;
1247 dev = dev_get_by_index(&init_net, ifindex);
1251 if (dev->type != ARPHRD_CAN) {
1260 /* read message head information */
1262 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1268 switch (msg_head.opcode) {
1271 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1275 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1279 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1286 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1293 /* reuse msg_head for the reply to TX_READ */
1294 msg_head.opcode = TX_STATUS;
1295 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1299 /* reuse msg_head for the reply to RX_READ */
1300 msg_head.opcode = RX_STATUS;
1301 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1305 /* we need exactly one can_frame behind the msg head */
1306 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1309 ret = bcm_tx_send(msg, ifindex, sk);
1323 * notification handler for netdevice status changes
1325 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1328 struct net_device *dev = (struct net_device *)data;
1329 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1330 struct sock *sk = &bo->sk;
1332 int notify_enodev = 0;
1334 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
1335 if (!net_eq(dev_net(dev), &init_net))
1337 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
1338 if (dev->nd_net != &init_net)
1342 if (dev->type != ARPHRD_CAN)
1347 case NETDEV_UNREGISTER:
1350 /* remove device specific receive entries */
1351 list_for_each_entry(op, &bo->rx_ops, list)
1352 if (op->rx_reg_dev == dev)
1353 bcm_rx_unreg(dev, op);
1355 /* remove device reference, if this is our bound device */
1356 if (bo->bound && bo->ifindex == dev->ifindex) {
1364 if (notify_enodev) {
1365 sk->sk_err = ENODEV;
1366 if (!sock_flag(sk, SOCK_DEAD))
1367 sk->sk_error_report(sk);
1372 if (bo->bound && bo->ifindex == dev->ifindex) {
1373 sk->sk_err = ENETDOWN;
1374 if (!sock_flag(sk, SOCK_DEAD))
1375 sk->sk_error_report(sk);
1383 * initial settings for all BCM sockets to be set at socket creation time
1385 static int bcm_init(struct sock *sk)
1387 struct bcm_sock *bo = bcm_sk(sk);
1391 bo->dropped_usr_msgs = 0;
1392 bo->bcm_proc_read = NULL;
1394 INIT_LIST_HEAD(&bo->tx_ops);
1395 INIT_LIST_HEAD(&bo->rx_ops);
1398 bo->notifier.notifier_call = bcm_notifier;
1400 register_netdevice_notifier(&bo->notifier);
1406 * standard socket functions
1408 static int bcm_release(struct socket *sock)
1410 struct sock *sk = sock->sk;
1411 struct bcm_sock *bo = bcm_sk(sk);
1412 struct bcm_op *op, *next;
1414 /* remove bcm_ops, timer, rx_unregister(), etc. */
1416 unregister_netdevice_notifier(&bo->notifier);
1420 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1423 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1425 * Don't care if we're bound or not (due to netdev problems)
1426 * can_rx_unregister() is always a save thing to do here.
1430 * Only remove subscriptions that had not
1431 * been removed due to NETDEV_UNREGISTER
1434 if (op->rx_reg_dev) {
1435 struct net_device *dev;
1437 dev = dev_get_by_index(&init_net, op->ifindex);
1439 bcm_rx_unreg(dev, op);
1444 can_rx_unregister(NULL, op->can_id,
1445 REGMASK(op->can_id),
1446 bcm_rx_handler, op);
1451 /* remove procfs entry */
1452 if (proc_dir && bo->bcm_proc_read)
1453 remove_proc_entry(bo->procname, proc_dir);
1455 /* remove device reference */
1467 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1470 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1471 struct sock *sk = sock->sk;
1472 struct bcm_sock *bo = bcm_sk(sk);
1477 /* bind a device to this socket */
1478 if (addr->can_ifindex) {
1479 struct net_device *dev;
1481 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1485 if (dev->type != ARPHRD_CAN) {
1490 bo->ifindex = dev->ifindex;
1494 /* no interface reference for ifindex = 0 ('any' CAN device) */
1501 /* unique socket address as filename */
1502 sprintf(bo->procname, "%p", sock);
1503 bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644,
1511 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1512 struct msghdr *msg, size_t size, int flags)
1514 struct sock *sk = sock->sk;
1515 struct sk_buff *skb;
1520 noblock = flags & MSG_DONTWAIT;
1521 flags &= ~MSG_DONTWAIT;
1522 skb = skb_recv_datagram(sk, flags, noblock, &error);
1526 if (skb->len < size)
1529 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1531 skb_free_datagram(sk, skb);
1535 sock_recv_timestamp(msg, sk, skb);
1537 if (msg->msg_name) {
1538 msg->msg_namelen = sizeof(struct sockaddr_can);
1539 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1542 skb_free_datagram(sk, skb);
1547 static struct proto_ops bcm_ops __read_mostly = {
1549 .release = bcm_release,
1550 .bind = sock_no_bind,
1551 .connect = bcm_connect,
1552 .socketpair = sock_no_socketpair,
1553 .accept = sock_no_accept,
1554 .getname = sock_no_getname,
1555 .poll = datagram_poll,
1556 .ioctl = NULL, /* use can_ioctl() from af_can.c */
1557 .listen = sock_no_listen,
1558 .shutdown = sock_no_shutdown,
1559 .setsockopt = sock_no_setsockopt,
1560 .getsockopt = sock_no_getsockopt,
1561 .sendmsg = bcm_sendmsg,
1562 .recvmsg = bcm_recvmsg,
1563 .mmap = sock_no_mmap,
1564 .sendpage = sock_no_sendpage,
1567 static struct proto bcm_proto __read_mostly = {
1569 .owner = THIS_MODULE,
1570 .obj_size = sizeof(struct bcm_sock),
1574 static struct can_proto bcm_can_proto __read_mostly = {
1576 .protocol = CAN_BCM,
1582 static int __init bcm_module_init(void)
1588 err = can_proto_register(&bcm_can_proto);
1590 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1594 /* create /proc/net/can-bcm directory */
1595 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
1596 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1598 proc_dir = proc_mkdir("can-bcm", proc_net);
1602 proc_dir->owner = THIS_MODULE;
1607 static void __exit bcm_module_exit(void)
1609 can_proto_unregister(&bcm_can_proto);
1612 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
1613 proc_net_remove(&init_net, "can-bcm");
1615 proc_net_remove("can-bcm");
1619 module_init(bcm_module_init);
1620 module_exit(bcm_module_exit);