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/list.h>
48 #include <linux/proc_fs.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 <socketcan/can.h>
56 #include <socketcan/can/core.h>
57 #include <socketcan/can/bcm.h>
61 #include <socketcan/can/version.h> /* for RCSID. Removed by mkpatch script */
64 /* use of last_frames[index].can_dlc */
65 #define RX_RECV 0x40 /* received data for this element */
66 #define RX_THR 0x80 /* element not been sent due to throttle feature */
67 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
69 /* get best masking value for can_rx_register() for a given single can_id */
70 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
71 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
72 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
74 #define CAN_BCM_VERSION CAN_VERSION
75 static __initdata const char banner[] = KERN_INFO
76 "can: broadcast manager protocol (rev " CAN_BCM_VERSION ")\n";
78 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
79 MODULE_LICENSE("Dual BSD/GPL");
80 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
81 MODULE_ALIAS("can-proto-2");
83 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
84 #error This code only supports Kernel versions _below_ 2.6.22
85 #error For 2.6.22+ Kernels please use bcm.c instead of bcm-prior-2-6-22.c
88 /* easy access to can_frame payload */
89 static inline u64 GET_U64(const struct can_frame *cp)
91 return *(u64 *)cp->data;
95 struct list_head list;
99 unsigned long frames_abs, frames_filtered;
100 struct timeval ival1, ival2;
101 struct timer_list timer, thrtimer;
102 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
103 struct skb_timeval rx_stamp;
105 struct timeval rx_stamp;
107 unsigned long j_ival1, j_ival2, j_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;
123 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
130 struct notifier_block notifier;
131 struct list_head rx_ops;
132 struct list_head tx_ops;
133 unsigned long dropped_usr_msgs;
134 struct proc_dir_entry *bcm_proc_read;
135 char procname [9]; /* pointer printed in ASCII with \0 */
138 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
140 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
141 return (struct bcm_sock *)sk;
143 return (struct bcm_sock *)sk->sk_protinfo;
147 #define CFSIZ sizeof(struct can_frame)
148 #define OPSIZ sizeof(struct bcm_op)
149 #define MHSIZ sizeof(struct bcm_msg_head)
152 * rounded_tv2jif - calculate jiffies from timeval including optional up
153 * @tv: pointer to timeval
156 * Unlike timeval_to_jiffies() provided in include/linux/jiffies.h, this
157 * function is intentionally more relaxed on precise timer ticks to get
158 * exact one jiffy for requested 1000us on a 1000HZ machine.
159 * This code is to be removed when upgrading to kernel hrtimer.
162 * calculated jiffies (max: ULONG_MAX)
164 static unsigned long rounded_tv2jif(const struct timeval *tv)
166 unsigned long sec = tv->tv_sec;
167 unsigned long usec = tv->tv_usec;
170 if (sec > ULONG_MAX / HZ)
173 /* round up to get at least the requested time */
174 usec += 1000000 / HZ - 1;
176 jif = usec / (1000000 / HZ);
178 if (sec * HZ > ULONG_MAX - jif)
181 return jif + sec * HZ;
187 static char *bcm_proc_getifname(int ifindex)
189 struct net_device *dev;
194 /* no usage counting */
195 dev = __dev_get_by_index(&init_net, ifindex);
202 static int bcm_read_proc(char *page, char **start, off_t off,
203 int count, int *eof, void *data)
206 struct sock *sk = (struct sock *)data;
207 struct bcm_sock *bo = bcm_sk(sk);
210 len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p",
212 len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk);
213 len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo);
214 len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu",
215 bo->dropped_usr_msgs);
216 len += snprintf(page + len, PAGE_SIZE - len, " / bound %s",
217 bcm_proc_getifname(bo->ifindex));
218 len += snprintf(page + len, PAGE_SIZE - len, " <<<\n");
220 list_for_each_entry(op, &bo->rx_ops, list) {
222 unsigned long reduction;
224 /* print only active entries & prevent division by zero */
228 len += snprintf(page + len, PAGE_SIZE - len,
230 op->can_id, bcm_proc_getifname(op->ifindex));
231 len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ",
233 (op->flags & RX_CHECK_DLC)?'d':' ');
235 len += snprintf(page + len, PAGE_SIZE - len,
236 "timeo=%ld ", op->j_ival1);
239 len += snprintf(page + len, PAGE_SIZE - len,
240 "thr=%ld ", op->j_ival2);
242 len += snprintf(page + len, PAGE_SIZE - len,
243 "# recv %ld (%ld) => reduction: ",
244 op->frames_filtered, op->frames_abs);
246 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
248 len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n",
249 (reduction == 100)?"near ":"", reduction);
251 if (len > PAGE_SIZE - 200) {
252 /* mark output cut off */
253 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
258 list_for_each_entry(op, &bo->tx_ops, list) {
260 len += snprintf(page + len, PAGE_SIZE - len,
261 "tx_op: %03X %s [%d] ",
262 op->can_id, bcm_proc_getifname(op->ifindex),
266 len += snprintf(page + len, PAGE_SIZE - len, "t1=%ld ",
270 len += snprintf(page + len, PAGE_SIZE - len, "t2=%ld ",
273 len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n",
276 if (len > PAGE_SIZE - 100) {
277 /* mark output cut off */
278 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
283 len += snprintf(page + len, PAGE_SIZE - len, "\n");
290 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
291 * of the given bcm tx op
293 static void bcm_can_tx(struct bcm_op *op)
296 struct net_device *dev;
297 struct can_frame *cf = &op->frames[op->currframe];
299 /* no target device? => exit */
303 dev = dev_get_by_index(&init_net, op->ifindex);
305 /* RFC: should this bcm_op remove itself here? */
309 skb = alloc_skb(CFSIZ, gfp_any());
313 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
315 /* send with loopback */
320 /* update statistics */
324 /* reached last frame? */
325 if (op->currframe >= op->nframes)
332 * bcm_send_to_user - send a BCM message to the userspace
333 * (consisting of bcm_msg_head + x CAN frames)
335 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
336 struct can_frame *frames, int has_timestamp)
339 struct can_frame *firstframe;
340 struct sockaddr_can *addr;
341 struct sock *sk = op->sk;
342 int datalen = head->nframes * CFSIZ;
345 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
349 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
352 /* can_frames starting here */
353 firstframe = (struct can_frame *)skb->tail;
355 memcpy(skb_put(skb, datalen), frames, datalen);
358 * the BCM uses the can_dlc-element of the can_frame
359 * structure for internal purposes. This is only
360 * relevant for updates that are generated by the
361 * BCM, where nframes is 1
363 if (head->nframes == 1)
364 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
368 /* restore rx timestamp */
369 skb->tstamp = op->rx_stamp;
373 * Put the datagram to the queue so that bcm_recvmsg() can
374 * get it from there. We need to pass the interface index to
375 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
376 * containing the interface index.
379 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
380 addr = (struct sockaddr_can *)skb->cb;
381 memset(addr, 0, sizeof(*addr));
382 addr->can_family = AF_CAN;
383 addr->can_ifindex = op->rx_ifindex;
385 err = sock_queue_rcv_skb(sk, skb);
387 struct bcm_sock *bo = bcm_sk(sk);
390 /* don't care about overflows in this statistic */
391 bo->dropped_usr_msgs++;
396 * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
398 static void bcm_tx_timeout_handler(unsigned long data)
400 struct bcm_op *op = (struct bcm_op *)data;
401 struct bcm_msg_head msg_head;
403 if (op->j_ival1 && (op->count > 0)) {
406 if (!op->count && (op->flags & TX_COUNTEVT)) {
408 /* create notification to user */
409 msg_head.opcode = TX_EXPIRED;
410 msg_head.flags = op->flags;
411 msg_head.count = op->count;
412 msg_head.ival1 = op->ival1;
413 msg_head.ival2 = op->ival2;
414 msg_head.can_id = op->can_id;
415 msg_head.nframes = 0;
417 bcm_send_to_user(op, &msg_head, NULL, 0);
420 /* send (next) frame */
422 mod_timer(&op->timer, jiffies + op->j_ival1);
427 /* send (next) frame */
429 mod_timer(&op->timer, jiffies + op->j_ival2);
435 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
437 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
439 struct bcm_msg_head head;
441 op->j_lastmsg = jiffies;
443 /* update statistics */
444 op->frames_filtered++;
446 /* prevent statistics overflow */
447 if (op->frames_filtered > ULONG_MAX/100)
448 op->frames_filtered = op->frames_abs = 0;
450 /* this element is not throttled anymore */
451 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
453 head.opcode = RX_CHANGED;
454 head.flags = op->flags;
455 head.count = op->count;
456 head.ival1 = op->ival1;
457 head.ival2 = op->ival2;
458 head.can_id = op->can_id;
461 bcm_send_to_user(op, &head, data, 1);
465 * bcm_rx_update_and_send - process a detected relevant receive content change
466 * 1. update the last received data
467 * 2. send a notification to the user (if possible)
469 static void bcm_rx_update_and_send(struct bcm_op *op,
470 struct can_frame *lastdata,
471 const struct can_frame *rxdata)
473 unsigned long nexttx = op->j_lastmsg + op->j_ival2;
475 memcpy(lastdata, rxdata, CFSIZ);
477 /* mark as used and throttled by default */
478 lastdata->can_dlc |= (RX_RECV|RX_THR);
480 /* throttle bcm_rx_changed ? */
481 if ((op->thrtimer.expires) ||
482 ((op->j_ival2) && (nexttx > jiffies))) {
483 /* we are already waiting OR we have to start waiting */
485 if (!(op->thrtimer.expires)) {
486 /* start the timer only the first time */
487 mod_timer(&op->thrtimer, nexttx);
491 /* send RX_CHANGED to the user immediately */
492 bcm_rx_changed(op, lastdata);
497 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
498 * received data stored in op->last_frames[]
500 static void bcm_rx_cmp_to_index(struct bcm_op *op, int index,
501 const struct can_frame *rxdata)
504 * no one uses the MSBs of can_dlc for comparation,
505 * so we use it here to detect the first time of reception
508 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
509 /* received data for the first time => send update to user */
510 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
514 /* do a real check in can_frame data section */
516 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
517 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
518 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
522 if (op->flags & RX_CHECK_DLC) {
523 /* do a real check in can_frame dlc */
524 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
526 bcm_rx_update_and_send(op, &op->last_frames[index],
534 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
536 static void bcm_rx_starttimer(struct bcm_op *op)
538 if (op->flags & RX_NO_AUTOTIMER)
542 mod_timer(&op->timer, jiffies + op->j_ival1);
546 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
548 static void bcm_rx_timeout_handler(unsigned long data)
550 struct bcm_op *op = (struct bcm_op *)data;
551 struct bcm_msg_head msg_head;
553 /* create notification to user */
554 msg_head.opcode = RX_TIMEOUT;
555 msg_head.flags = op->flags;
556 msg_head.count = op->count;
557 msg_head.ival1 = op->ival1;
558 msg_head.ival2 = op->ival2;
559 msg_head.can_id = op->can_id;
560 msg_head.nframes = 0;
562 bcm_send_to_user(op, &msg_head, NULL, 0);
564 /* no restart of the timer is done here! */
566 /* if user wants to be informed, when cyclic CAN-Messages come back */
567 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
568 /* clear received can_frames to indicate 'nothing received' */
569 memset(op->last_frames, 0, op->nframes * CFSIZ);
574 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
576 static inline int bcm_rx_do_flush(struct bcm_op *op, int index)
578 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
579 bcm_rx_changed(op, &op->last_frames[index]);
586 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
588 static int bcm_rx_thr_flush(struct bcm_op *op)
592 if (op->nframes > 1) {
595 /* for MUX filter we start at index 1 */
596 for (i = 1; i < op->nframes; i++)
597 updated += bcm_rx_do_flush(op, i);
600 /* for RX_FILTER_ID and simple filter */
601 updated += bcm_rx_do_flush(op, 0);
608 * bcm_rx_thr_handler - the time for blocked content updates is over now:
609 * Check for throttled data and send it to the userspace
611 static void bcm_rx_thr_handler(unsigned long data)
613 struct bcm_op *op = (struct bcm_op *)data;
615 if (bcm_rx_thr_flush(op))
616 mod_timer(&op->thrtimer, jiffies + op->j_ival2);
618 /* mark disabled / consumed timer */
619 op->thrtimer.expires = 0;
624 * bcm_rx_handler - handle a CAN frame receiption
626 static void bcm_rx_handler(struct sk_buff *skb, void *data)
628 struct bcm_op *op = (struct bcm_op *)data;
629 const struct can_frame *rxframe = (struct can_frame *)skb->data;
632 /* disable timeout */
633 del_timer(&op->timer);
635 if (op->can_id != rxframe->can_id)
638 /* save rx timestamp */
639 op->rx_stamp = skb->tstamp;
640 /* save originator for recvfrom() */
641 op->rx_ifindex = skb->dev->ifindex;
642 /* update statistics */
645 if (op->flags & RX_RTR_FRAME) {
646 /* send reply for RTR-request (placed in op->frames[0]) */
651 if (op->flags & RX_FILTER_ID) {
652 /* the easiest case */
653 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
657 if (op->nframes == 1) {
658 /* simple compare with index 0 */
659 bcm_rx_cmp_to_index(op, 0, rxframe);
663 if (op->nframes > 1) {
667 * find the first multiplex mask that fits.
668 * Remark: The MUX-mask is stored in index 0
671 for (i = 1; i < op->nframes; i++) {
672 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
673 (GET_U64(&op->frames[0]) &
674 GET_U64(&op->frames[i]))) {
675 bcm_rx_cmp_to_index(op, i, rxframe);
682 bcm_rx_starttimer(op);
686 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
688 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
693 list_for_each_entry(op, ops, list) {
694 if ((op->can_id == can_id) && (op->ifindex == ifindex))
701 static void bcm_remove_op(struct bcm_op *op)
703 del_timer(&op->timer);
704 del_timer(&op->thrtimer);
706 if ((op->frames) && (op->frames != &op->sframe))
709 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
710 kfree(op->last_frames);
717 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
719 if (op->rx_reg_dev == dev) {
720 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
723 /* mark as removed subscription */
724 op->rx_reg_dev = NULL;
726 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
727 "mismatch %p %p\n", op->rx_reg_dev, dev);
731 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
733 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
735 struct bcm_op *op, *n;
737 list_for_each_entry_safe(op, n, ops, list) {
738 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
741 * Don't care if we're bound or not (due to netdev
742 * problems) can_rx_unregister() is always a save
747 * Only remove subscriptions that had not
748 * been removed due to NETDEV_UNREGISTER
751 if (op->rx_reg_dev) {
752 struct net_device *dev;
754 dev = dev_get_by_index(&init_net,
757 bcm_rx_unreg(dev, op);
762 can_rx_unregister(NULL, op->can_id,
772 return 0; /* not found */
776 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
778 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
780 struct bcm_op *op, *n;
782 list_for_each_entry_safe(op, n, ops, list) {
783 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
790 return 0; /* not found */
794 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
796 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
799 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
804 /* put current values into msg_head */
805 msg_head->flags = op->flags;
806 msg_head->count = op->count;
807 msg_head->ival1 = op->ival1;
808 msg_head->ival2 = op->ival2;
809 msg_head->nframes = op->nframes;
811 bcm_send_to_user(op, msg_head, op->frames, 0);
817 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
819 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
820 int ifindex, struct sock *sk)
822 struct bcm_sock *bo = bcm_sk(sk);
826 /* we need a real device to send frames */
830 /* we need at least one can_frame */
831 if (msg_head->nframes < 1)
834 /* check the given can_id */
835 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
838 /* update existing BCM operation */
841 * Do we need more space for the can_frames than currently
842 * allocated? -> This is a _really_ unusual use-case and
843 * therefore (complexity / locking) it is not supported.
845 if (msg_head->nframes > op->nframes)
848 /* update can_frames content */
849 for (i = 0; i < msg_head->nframes; i++) {
850 err = memcpy_fromiovec((u8 *)&op->frames[i],
851 msg->msg_iov, CFSIZ);
853 if (op->frames[i].can_dlc > 8)
859 if (msg_head->flags & TX_CP_CAN_ID) {
860 /* copy can_id into frame */
861 op->frames[i].can_id = msg_head->can_id;
866 /* insert new BCM operation for the given can_id */
868 op = kzalloc(OPSIZ, GFP_KERNEL);
872 op->can_id = msg_head->can_id;
874 /* create array for can_frames and copy the data */
875 if (msg_head->nframes > 1) {
876 op->frames = kmalloc(msg_head->nframes * CFSIZ,
883 op->frames = &op->sframe;
885 for (i = 0; i < msg_head->nframes; i++) {
886 err = memcpy_fromiovec((u8 *)&op->frames[i],
887 msg->msg_iov, CFSIZ);
889 if (op->frames[i].can_dlc > 8)
893 if (op->frames != &op->sframe)
899 if (msg_head->flags & TX_CP_CAN_ID) {
900 /* copy can_id into frame */
901 op->frames[i].can_id = msg_head->can_id;
905 /* tx_ops never compare with previous received messages */
906 op->last_frames = NULL;
908 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
910 op->ifindex = ifindex;
912 /* initialize uninitialized (kzalloc) structure */
913 setup_timer(&op->timer, bcm_tx_timeout_handler,
916 /* currently unused in tx_ops */
917 init_timer(&op->thrtimer);
919 /* add this bcm_op to the list of the tx_ops */
920 list_add(&op->list, &bo->tx_ops);
922 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
924 if (op->nframes != msg_head->nframes) {
925 op->nframes = msg_head->nframes;
926 /* start multiple frame transmission with index 0 */
932 op->flags = msg_head->flags;
934 if (op->flags & TX_RESET_MULTI_IDX) {
935 /* start multiple frame transmission with index 0 */
939 if (op->flags & SETTIMER) {
940 /* set timer values */
941 op->count = msg_head->count;
942 op->ival1 = msg_head->ival1;
943 op->ival2 = msg_head->ival2;
944 op->j_ival1 = rounded_tv2jif(&msg_head->ival1);
945 op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
947 /* disable an active timer due to zero values? */
948 if (!op->j_ival1 && !op->j_ival2)
949 del_timer(&op->timer);
952 if ((op->flags & STARTTIMER) &&
953 ((op->j_ival1 && op->count) || op->j_ival2)) {
955 /* spec: send can_frame when starting timer */
956 op->flags |= TX_ANNOUNCE;
958 /* only start timer when having more frames than sent below */
959 if (op->j_ival1 && (op->count > 1)) {
960 /* op->count-- is done in bcm_tx_timeout_handler */
961 mod_timer(&op->timer, jiffies + op->j_ival1);
963 mod_timer(&op->timer, jiffies + op->j_ival2);
966 if (op->flags & TX_ANNOUNCE) {
968 if (op->j_ival1 && (op->count > 0))
972 return msg_head->nframes * CFSIZ + MHSIZ;
976 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
978 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
979 int ifindex, struct sock *sk)
981 struct bcm_sock *bo = bcm_sk(sk);
986 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
987 /* be robust against wrong usage ... */
988 msg_head->flags |= RX_FILTER_ID;
989 /* ignore trailing garbage */
990 msg_head->nframes = 0;
993 if ((msg_head->flags & RX_RTR_FRAME) &&
994 ((msg_head->nframes != 1) ||
995 (!(msg_head->can_id & CAN_RTR_FLAG))))
998 /* check the given can_id */
999 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1001 /* update existing BCM operation */
1004 * Do we need more space for the can_frames than currently
1005 * allocated? -> This is a _really_ unusual use-case and
1006 * therefore (complexity / locking) it is not supported.
1008 if (msg_head->nframes > op->nframes)
1011 if (msg_head->nframes) {
1012 /* update can_frames content */
1013 err = memcpy_fromiovec((u8 *)op->frames,
1015 msg_head->nframes * CFSIZ);
1019 /* clear last_frames to indicate 'nothing received' */
1020 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1023 op->nframes = msg_head->nframes;
1025 /* Only an update -> do not call can_rx_register() */
1029 /* insert new BCM operation for the given can_id */
1030 op = kzalloc(OPSIZ, GFP_KERNEL);
1034 op->can_id = msg_head->can_id;
1035 op->nframes = msg_head->nframes;
1037 if (msg_head->nframes > 1) {
1038 /* create array for can_frames and copy the data */
1039 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1046 /* create and init array for received can_frames */
1047 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1049 if (!op->last_frames) {
1056 op->frames = &op->sframe;
1057 op->last_frames = &op->last_sframe;
1060 if (msg_head->nframes) {
1061 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1062 msg_head->nframes * CFSIZ);
1064 if (op->frames != &op->sframe)
1066 if (op->last_frames != &op->last_sframe)
1067 kfree(op->last_frames);
1073 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1075 op->ifindex = ifindex;
1077 /* initialize uninitialized (kzalloc) structure */
1078 setup_timer(&op->timer, bcm_rx_timeout_handler,
1081 /* init throttle timer for RX_CHANGED */
1082 setup_timer(&op->thrtimer, bcm_rx_thr_handler,
1085 /* mark disabled timer */
1086 op->thrtimer.expires = 0;
1088 /* add this bcm_op to the list of the rx_ops */
1089 list_add(&op->list, &bo->rx_ops);
1091 /* call can_rx_register() */
1094 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1097 op->flags = msg_head->flags;
1099 if (op->flags & RX_RTR_FRAME) {
1101 /* no timers in RTR-mode */
1102 del_timer(&op->thrtimer);
1103 del_timer(&op->timer);
1106 * funny feature in RX(!)_SETUP only for RTR-mode:
1107 * copy can_id into frame BUT without RTR-flag to
1108 * prevent a full-load-loopback-test ... ;-]
1110 if ((op->flags & TX_CP_CAN_ID) ||
1111 (op->frames[0].can_id == op->can_id))
1112 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1115 if (op->flags & SETTIMER) {
1117 /* set timer value */
1118 op->ival1 = msg_head->ival1;
1119 op->ival2 = msg_head->ival2;
1120 op->j_ival1 = rounded_tv2jif(&msg_head->ival1);
1121 op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
1123 /* disable an active timer due to zero value? */
1125 del_timer(&op->timer);
1128 * In any case cancel the throttle timer, flush
1129 * potentially blocked msgs and reset throttle handling
1131 del_timer(&op->thrtimer);
1132 bcm_rx_thr_flush(op);
1133 op->thrtimer.expires = 0;
1136 if ((op->flags & STARTTIMER) && op->j_ival1)
1137 mod_timer(&op->timer, jiffies + op->j_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 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
1331 struct sock *sk = &bo->sk;
1333 struct sock *sk = bo->sk;
1336 int notify_enodev = 0;
1338 if (dev->type != ARPHRD_CAN)
1343 case NETDEV_UNREGISTER:
1346 /* remove device specific receive entries */
1347 list_for_each_entry(op, &bo->rx_ops, list)
1348 if (op->rx_reg_dev == dev)
1349 bcm_rx_unreg(dev, op);
1351 /* remove device reference, if this is our bound device */
1352 if (bo->bound && bo->ifindex == dev->ifindex) {
1360 if (notify_enodev) {
1361 sk->sk_err = ENODEV;
1362 if (!sock_flag(sk, SOCK_DEAD))
1363 sk->sk_error_report(sk);
1368 if (bo->bound && bo->ifindex == dev->ifindex) {
1369 sk->sk_err = ENETDOWN;
1370 if (!sock_flag(sk, SOCK_DEAD))
1371 sk->sk_error_report(sk);
1379 * initial settings for all BCM sockets to be set at socket creation time
1381 static int bcm_init(struct sock *sk)
1383 struct bcm_sock *bo = bcm_sk(sk);
1385 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
1390 bo->dropped_usr_msgs = 0;
1391 bo->bcm_proc_read = NULL;
1393 INIT_LIST_HEAD(&bo->tx_ops);
1394 INIT_LIST_HEAD(&bo->rx_ops);
1397 bo->notifier.notifier_call = bcm_notifier;
1399 register_netdevice_notifier(&bo->notifier);
1405 * standard socket functions
1407 static int bcm_release(struct socket *sock)
1409 struct sock *sk = sock->sk;
1410 struct bcm_sock *bo = bcm_sk(sk);
1411 struct bcm_op *op, *next;
1413 /* remove bcm_ops, timer, rx_unregister(), etc. */
1415 unregister_netdevice_notifier(&bo->notifier);
1419 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1422 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1424 * Don't care if we're bound or not (due to netdev problems)
1425 * can_rx_unregister() is always a save thing to do here.
1429 * Only remove subscriptions that had not
1430 * been removed due to NETDEV_UNREGISTER
1433 if (op->rx_reg_dev) {
1434 struct net_device *dev;
1436 dev = dev_get_by_index(&init_net, op->ifindex);
1438 bcm_rx_unreg(dev, op);
1443 can_rx_unregister(NULL, op->can_id,
1444 REGMASK(op->can_id),
1445 bcm_rx_handler, op);
1450 /* remove procfs entry */
1451 if (proc_dir && bo->bcm_proc_read)
1452 remove_proc_entry(bo->procname, proc_dir);
1454 /* remove device reference */
1469 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1472 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1473 struct sock *sk = sock->sk;
1474 struct bcm_sock *bo = bcm_sk(sk);
1479 /* bind a device to this socket */
1480 if (addr->can_ifindex) {
1481 struct net_device *dev;
1483 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1487 if (dev->type != ARPHRD_CAN) {
1492 bo->ifindex = dev->ifindex;
1496 /* no interface reference for ifindex = 0 ('any' CAN device) */
1503 /* unique socket address as filename */
1504 sprintf(bo->procname, "%p", sock);
1505 bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644,
1513 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1514 struct msghdr *msg, size_t size, int flags)
1516 struct sock *sk = sock->sk;
1517 struct sk_buff *skb;
1522 noblock = flags & MSG_DONTWAIT;
1523 flags &= ~MSG_DONTWAIT;
1524 skb = skb_recv_datagram(sk, flags, noblock, &error);
1528 if (skb->len < size)
1531 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1533 skb_free_datagram(sk, skb);
1537 sock_recv_timestamp(msg, sk, skb);
1539 if (msg->msg_name) {
1540 msg->msg_namelen = sizeof(struct sockaddr_can);
1541 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1544 skb_free_datagram(sk, skb);
1549 static const struct proto_ops bcm_ops = {
1551 .release = bcm_release,
1552 .bind = sock_no_bind,
1553 .connect = bcm_connect,
1554 .socketpair = sock_no_socketpair,
1555 .accept = sock_no_accept,
1556 .getname = sock_no_getname,
1557 .poll = datagram_poll,
1558 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1559 .listen = sock_no_listen,
1560 .shutdown = sock_no_shutdown,
1561 .setsockopt = sock_no_setsockopt,
1562 .getsockopt = sock_no_getsockopt,
1563 .sendmsg = bcm_sendmsg,
1564 .recvmsg = bcm_recvmsg,
1565 .mmap = sock_no_mmap,
1566 .sendpage = sock_no_sendpage,
1569 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
1570 static struct proto bcm_proto __read_mostly = {
1572 .owner = THIS_MODULE,
1573 .obj_size = sizeof(struct bcm_sock),
1577 static const struct can_proto bcm_can_proto = {
1579 .protocol = CAN_BCM,
1585 static const struct can_proto bcm_can_proto = {
1587 .protocol = CAN_BCM,
1590 .owner = THIS_MODULE,
1591 .obj_size = sizeof(struct bcm_sock),
1596 static int __init bcm_module_init(void)
1602 err = can_proto_register(&bcm_can_proto);
1604 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1608 /* create /proc/net/can-bcm directory */
1609 proc_dir = proc_mkdir("can-bcm", proc_net);
1612 proc_dir->owner = THIS_MODULE;
1617 static void __exit bcm_module_exit(void)
1619 can_proto_unregister(&bcm_can_proto);
1622 proc_net_remove("can-bcm");
1625 module_init(bcm_module_init);
1626 module_exit(bcm_module_exit);