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
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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 <linux/can.h>
56 #include <linux/can/core.h>
57 #include <linux/can/bcm.h>
61 #include <linux/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>");
82 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
83 #error This code only supports Kernel versions _below_ 2.6.22
84 #error For 2.6.22+ Kernels please use bcm.c instead of bcm-prior-2-6-22.c
87 /* easy access to can_frame payload */
88 static inline u64 GET_U64(const struct can_frame *cp)
90 return *(u64 *)cp->data;
94 struct list_head list;
98 unsigned long frames_abs, frames_filtered;
99 struct timeval ival1, ival2;
100 struct timer_list timer, thrtimer;
101 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
102 struct skb_timeval rx_stamp;
104 struct timeval rx_stamp;
106 unsigned long j_ival1, j_ival2, j_lastmsg;
111 struct can_frame *frames;
112 struct can_frame *last_frames;
113 struct can_frame sframe;
114 struct can_frame last_sframe;
116 struct net_device *rx_reg_dev;
119 static struct proc_dir_entry *proc_dir;
122 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
129 struct notifier_block notifier;
130 struct list_head rx_ops;
131 struct list_head tx_ops;
132 unsigned long dropped_usr_msgs;
133 struct proc_dir_entry *bcm_proc_read;
134 char procname [9]; /* pointer printed in ASCII with \0 */
137 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
139 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
140 return (struct bcm_sock *)sk;
142 return (struct bcm_sock *)sk->sk_protinfo;
146 #define CFSIZ sizeof(struct can_frame)
147 #define OPSIZ sizeof(struct bcm_op)
148 #define MHSIZ sizeof(struct bcm_msg_head)
151 * rounded_tv2jif - calculate jiffies from timeval including optional up
152 * @tv: pointer to timeval
155 * Unlike timeval_to_jiffies() provided in include/linux/jiffies.h, this
156 * function is intentionally more relaxed on precise timer ticks to get
157 * exact one jiffy for requested 1000us on a 1000HZ machine.
158 * This code is to be removed when upgrading to kernel hrtimer.
161 * calculated jiffies (max: ULONG_MAX)
163 static unsigned long rounded_tv2jif(const struct timeval *tv)
165 unsigned long sec = tv->tv_sec;
166 unsigned long usec = tv->tv_usec;
169 if (sec > ULONG_MAX / HZ)
172 /* round up to get at least the requested time */
173 usec += 1000000 / HZ - 1;
175 jif = usec / (1000000 / HZ);
177 if (sec * HZ > ULONG_MAX - jif)
180 return jif + sec * HZ;
186 static char *bcm_proc_getifname(int ifindex)
188 struct net_device *dev;
193 /* no usage counting */
194 dev = __dev_get_by_index(&init_net, ifindex);
201 static int bcm_read_proc(char *page, char **start, off_t off,
202 int count, int *eof, void *data)
205 struct sock *sk = (struct sock *)data;
206 struct bcm_sock *bo = bcm_sk(sk);
209 len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p",
211 len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk);
212 len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo);
213 len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu",
214 bo->dropped_usr_msgs);
215 len += snprintf(page + len, PAGE_SIZE - len, " / bound %s",
216 bcm_proc_getifname(bo->ifindex));
217 len += snprintf(page + len, PAGE_SIZE - len, " <<<\n");
219 list_for_each_entry(op, &bo->rx_ops, list) {
221 unsigned long reduction;
223 /* print only active entries & prevent division by zero */
227 len += snprintf(page + len, PAGE_SIZE - len,
229 op->can_id, bcm_proc_getifname(op->ifindex));
230 len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ",
232 (op->flags & RX_CHECK_DLC)?'d':' ');
234 len += snprintf(page + len, PAGE_SIZE - len,
235 "timeo=%ld ", op->j_ival1);
238 len += snprintf(page + len, PAGE_SIZE - len,
239 "thr=%ld ", op->j_ival2);
241 len += snprintf(page + len, PAGE_SIZE - len,
242 "# recv %ld (%ld) => reduction: ",
243 op->frames_filtered, op->frames_abs);
245 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
247 len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n",
248 (reduction == 100)?"near ":"", reduction);
250 if (len > PAGE_SIZE - 200) {
251 /* mark output cut off */
252 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
257 list_for_each_entry(op, &bo->tx_ops, list) {
259 len += snprintf(page + len, PAGE_SIZE - len,
260 "tx_op: %03X %s [%d] ",
261 op->can_id, bcm_proc_getifname(op->ifindex),
265 len += snprintf(page + len, PAGE_SIZE - len, "t1=%ld ",
269 len += snprintf(page + len, PAGE_SIZE - len, "t2=%ld ",
272 len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n",
275 if (len > PAGE_SIZE - 100) {
276 /* mark output cut off */
277 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
282 len += snprintf(page + len, PAGE_SIZE - len, "\n");
289 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
290 * of the given bcm tx op
292 static void bcm_can_tx(struct bcm_op *op)
295 struct net_device *dev;
296 struct can_frame *cf = &op->frames[op->currframe];
298 /* no target device? => exit */
302 dev = dev_get_by_index(&init_net, op->ifindex);
304 /* RFC: should this bcm_op remove itself here? */
308 skb = alloc_skb(CFSIZ, gfp_any());
312 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
314 /* send with loopback */
319 /* update statistics */
323 /* reached last frame? */
324 if (op->currframe >= op->nframes)
331 * bcm_send_to_user - send a BCM message to the userspace
332 * (consisting of bcm_msg_head + x CAN frames)
334 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
335 struct can_frame *frames, int has_timestamp)
338 struct can_frame *firstframe;
339 struct sockaddr_can *addr;
340 struct sock *sk = op->sk;
341 int datalen = head->nframes * CFSIZ;
344 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
348 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
351 /* can_frames starting here */
352 firstframe = (struct can_frame *)skb->tail;
354 memcpy(skb_put(skb, datalen), frames, datalen);
357 * the BCM uses the can_dlc-element of the can_frame
358 * structure for internal purposes. This is only
359 * relevant for updates that are generated by the
360 * BCM, where nframes is 1
362 if (head->nframes == 1)
363 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
367 /* restore rx timestamp */
368 skb->tstamp = op->rx_stamp;
372 * Put the datagram to the queue so that bcm_recvmsg() can
373 * get it from there. We need to pass the interface index to
374 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
375 * containing the interface index.
378 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
379 addr = (struct sockaddr_can *)skb->cb;
380 memset(addr, 0, sizeof(*addr));
381 addr->can_family = AF_CAN;
382 addr->can_ifindex = op->rx_ifindex;
384 err = sock_queue_rcv_skb(sk, skb);
386 struct bcm_sock *bo = bcm_sk(sk);
389 /* don't care about overflows in this statistic */
390 bo->dropped_usr_msgs++;
395 * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
397 static void bcm_tx_timeout_handler(unsigned long data)
399 struct bcm_op *op = (struct bcm_op *)data;
400 struct bcm_msg_head msg_head;
402 if (op->j_ival1 && (op->count > 0)) {
405 if (!op->count && (op->flags & TX_COUNTEVT)) {
407 /* create notification to user */
408 msg_head.opcode = TX_EXPIRED;
409 msg_head.flags = op->flags;
410 msg_head.count = op->count;
411 msg_head.ival1 = op->ival1;
412 msg_head.ival2 = op->ival2;
413 msg_head.can_id = op->can_id;
414 msg_head.nframes = 0;
416 bcm_send_to_user(op, &msg_head, NULL, 0);
420 if (op->j_ival1 && (op->count > 0)) {
422 /* send (next) frame */
424 mod_timer(&op->timer, jiffies + op->j_ival1);
429 /* send (next) frame */
431 mod_timer(&op->timer, jiffies + op->j_ival2);
437 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
439 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
441 struct bcm_msg_head head;
443 op->j_lastmsg = jiffies;
445 /* update statistics */
446 op->frames_filtered++;
448 /* prevent statistics overflow */
449 if (op->frames_filtered > ULONG_MAX/100)
450 op->frames_filtered = op->frames_abs = 0;
452 /* this element is not throttled anymore */
453 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
455 head.opcode = RX_CHANGED;
456 head.flags = op->flags;
457 head.count = op->count;
458 head.ival1 = op->ival1;
459 head.ival2 = op->ival2;
460 head.can_id = op->can_id;
463 bcm_send_to_user(op, &head, data, 1);
467 * bcm_rx_update_and_send - process a detected relevant receive content change
468 * 1. update the last received data
469 * 2. send a notification to the user (if possible)
471 static void bcm_rx_update_and_send(struct bcm_op *op,
472 struct can_frame *lastdata,
473 const struct can_frame *rxdata)
475 unsigned long nexttx = op->j_lastmsg + op->j_ival2;
477 memcpy(lastdata, rxdata, CFSIZ);
479 /* mark as used and throttled by default */
480 lastdata->can_dlc |= (RX_RECV|RX_THR);
482 /* throttle bcm_rx_changed ? */
483 if ((op->thrtimer.expires) ||
484 ((op->j_ival2) && (nexttx > jiffies))) {
485 /* we are already waiting OR we have to start waiting */
487 if (!(op->thrtimer.expires)) {
488 /* start the timer only the first time */
489 mod_timer(&op->thrtimer, nexttx);
493 /* send RX_CHANGED to the user immediately */
494 bcm_rx_changed(op, lastdata);
499 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
500 * received data stored in op->last_frames[]
502 static void bcm_rx_cmp_to_index(struct bcm_op *op, int index,
503 const struct can_frame *rxdata)
506 * no one uses the MSBs of can_dlc for comparation,
507 * so we use it here to detect the first time of reception
510 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
511 /* received data for the first time => send update to user */
512 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
516 /* do a real check in can_frame data section */
518 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
519 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
520 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
524 if (op->flags & RX_CHECK_DLC) {
525 /* do a real check in can_frame dlc */
526 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
528 bcm_rx_update_and_send(op, &op->last_frames[index],
536 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
538 static void bcm_rx_starttimer(struct bcm_op *op)
540 if (op->flags & RX_NO_AUTOTIMER)
544 mod_timer(&op->timer, jiffies + op->j_ival1);
548 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
550 static void bcm_rx_timeout_handler(unsigned long data)
552 struct bcm_op *op = (struct bcm_op *)data;
553 struct bcm_msg_head msg_head;
555 /* create notification to user */
556 msg_head.opcode = RX_TIMEOUT;
557 msg_head.flags = op->flags;
558 msg_head.count = op->count;
559 msg_head.ival1 = op->ival1;
560 msg_head.ival2 = op->ival2;
561 msg_head.can_id = op->can_id;
562 msg_head.nframes = 0;
564 bcm_send_to_user(op, &msg_head, NULL, 0);
566 /* no restart of the timer is done here! */
568 /* if user wants to be informed, when cyclic CAN-Messages come back */
569 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
570 /* clear received can_frames to indicate 'nothing received' */
571 memset(op->last_frames, 0, op->nframes * CFSIZ);
576 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
578 static inline int bcm_rx_do_flush(struct bcm_op *op, int index)
580 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
581 bcm_rx_changed(op, &op->last_frames[index]);
588 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
590 static int bcm_rx_thr_flush(struct bcm_op *op)
594 if (op->nframes > 1) {
597 /* for MUX filter we start at index 1 */
598 for (i = 1; i < op->nframes; i++)
599 updated += bcm_rx_do_flush(op, i);
602 /* for RX_FILTER_ID and simple filter */
603 updated += bcm_rx_do_flush(op, 0);
610 * bcm_rx_thr_handler - the time for blocked content updates is over now:
611 * Check for throttled data and send it to the userspace
613 static void bcm_rx_thr_handler(unsigned long data)
615 struct bcm_op *op = (struct bcm_op *)data;
617 if (bcm_rx_thr_flush(op))
618 mod_timer(&op->thrtimer, jiffies + op->j_ival2);
620 /* mark disabled / consumed timer */
621 op->thrtimer.expires = 0;
626 * bcm_rx_handler - handle a CAN frame receiption
628 static void bcm_rx_handler(struct sk_buff *skb, void *data)
630 struct bcm_op *op = (struct bcm_op *)data;
631 const struct can_frame *rxframe = (struct can_frame *)skb->data;
634 /* disable timeout */
635 del_timer(&op->timer);
637 if (op->can_id != rxframe->can_id)
640 /* save rx timestamp */
641 op->rx_stamp = skb->tstamp;
642 /* save originator for recvfrom() */
643 op->rx_ifindex = skb->dev->ifindex;
644 /* update statistics */
647 if (op->flags & RX_RTR_FRAME) {
648 /* send reply for RTR-request (placed in op->frames[0]) */
653 if (op->flags & RX_FILTER_ID) {
654 /* the easiest case */
655 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
659 if (op->nframes == 1) {
660 /* simple compare with index 0 */
661 bcm_rx_cmp_to_index(op, 0, rxframe);
665 if (op->nframes > 1) {
669 * find the first multiplex mask that fits.
670 * Remark: The MUX-mask is stored in index 0
673 for (i = 1; i < op->nframes; i++) {
674 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
675 (GET_U64(&op->frames[0]) &
676 GET_U64(&op->frames[i]))) {
677 bcm_rx_cmp_to_index(op, i, rxframe);
684 bcm_rx_starttimer(op);
688 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
690 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
695 list_for_each_entry(op, ops, list) {
696 if ((op->can_id == can_id) && (op->ifindex == ifindex))
703 static void bcm_remove_op(struct bcm_op *op)
705 del_timer(&op->timer);
706 del_timer(&op->thrtimer);
708 if ((op->frames) && (op->frames != &op->sframe))
711 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
712 kfree(op->last_frames);
719 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
721 if (op->rx_reg_dev == dev) {
722 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
725 /* mark as removed subscription */
726 op->rx_reg_dev = NULL;
728 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
729 "mismatch %p %p\n", op->rx_reg_dev, dev);
733 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
735 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
737 struct bcm_op *op, *n;
739 list_for_each_entry_safe(op, n, ops, list) {
740 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
743 * Don't care if we're bound or not (due to netdev
744 * problems) can_rx_unregister() is always a save
749 * Only remove subscriptions that had not
750 * been removed due to NETDEV_UNREGISTER
753 if (op->rx_reg_dev) {
754 struct net_device *dev;
756 dev = dev_get_by_index(&init_net,
759 bcm_rx_unreg(dev, op);
764 can_rx_unregister(NULL, op->can_id,
774 return 0; /* not found */
778 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
780 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
782 struct bcm_op *op, *n;
784 list_for_each_entry_safe(op, n, ops, list) {
785 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
792 return 0; /* not found */
796 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
798 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
801 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
806 /* put current values into msg_head */
807 msg_head->flags = op->flags;
808 msg_head->count = op->count;
809 msg_head->ival1 = op->ival1;
810 msg_head->ival2 = op->ival2;
811 msg_head->nframes = op->nframes;
813 bcm_send_to_user(op, msg_head, op->frames, 0);
819 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
821 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
822 int ifindex, struct sock *sk)
824 struct bcm_sock *bo = bcm_sk(sk);
828 /* we need a real device to send frames */
832 /* we need at least one can_frame */
833 if (msg_head->nframes < 1)
836 /* check the given can_id */
837 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
840 /* update existing BCM operation */
843 * Do we need more space for the can_frames than currently
844 * allocated? -> This is a _really_ unusual use-case and
845 * therefore (complexity / locking) it is not supported.
847 if (msg_head->nframes > op->nframes)
850 /* update can_frames content */
851 for (i = 0; i < msg_head->nframes; i++) {
852 err = memcpy_fromiovec((u8 *)&op->frames[i],
853 msg->msg_iov, CFSIZ);
855 if (op->frames[i].can_dlc > 8)
861 if (msg_head->flags & TX_CP_CAN_ID) {
862 /* copy can_id into frame */
863 op->frames[i].can_id = msg_head->can_id;
868 /* insert new BCM operation for the given can_id */
870 op = kzalloc(OPSIZ, GFP_KERNEL);
874 op->can_id = msg_head->can_id;
876 /* create array for can_frames and copy the data */
877 if (msg_head->nframes > 1) {
878 op->frames = kmalloc(msg_head->nframes * CFSIZ,
885 op->frames = &op->sframe;
887 for (i = 0; i < msg_head->nframes; i++) {
888 err = memcpy_fromiovec((u8 *)&op->frames[i],
889 msg->msg_iov, CFSIZ);
891 if (op->frames[i].can_dlc > 8)
895 if (op->frames != &op->sframe)
901 if (msg_head->flags & TX_CP_CAN_ID) {
902 /* copy can_id into frame */
903 op->frames[i].can_id = msg_head->can_id;
907 /* tx_ops never compare with previous received messages */
908 op->last_frames = NULL;
910 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
912 op->ifindex = ifindex;
914 /* initialize uninitialized (kzalloc) structure */
915 setup_timer(&op->timer, bcm_tx_timeout_handler,
918 /* currently unused in tx_ops */
919 init_timer(&op->thrtimer);
921 /* add this bcm_op to the list of the tx_ops */
922 list_add(&op->list, &bo->tx_ops);
924 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
926 if (op->nframes != msg_head->nframes) {
927 op->nframes = msg_head->nframes;
928 /* start multiple frame transmission with index 0 */
934 op->flags = msg_head->flags;
936 if (op->flags & TX_RESET_MULTI_IDX) {
937 /* start multiple frame transmission with index 0 */
941 if (op->flags & SETTIMER) {
942 /* set timer values */
943 op->count = msg_head->count;
944 op->ival1 = msg_head->ival1;
945 op->ival2 = msg_head->ival2;
946 op->j_ival1 = rounded_tv2jif(&msg_head->ival1);
947 op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
949 /* disable an active timer due to zero values? */
950 if (!op->j_ival1 && !op->j_ival2)
951 del_timer(&op->timer);
954 if ((op->flags & STARTTIMER) &&
955 ((op->j_ival1 && op->count) || op->j_ival2)) {
957 /* spec: send can_frame when starting timer */
958 op->flags |= TX_ANNOUNCE;
960 if (op->j_ival1 && (op->count > 0)) {
961 /* op->count-- is done in bcm_tx_timeout_handler */
962 mod_timer(&op->timer, jiffies + op->j_ival1);
964 mod_timer(&op->timer, jiffies + op->j_ival2);
967 if (op->flags & TX_ANNOUNCE)
970 return msg_head->nframes * CFSIZ + MHSIZ;
974 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
976 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
977 int ifindex, struct sock *sk)
979 struct bcm_sock *bo = bcm_sk(sk);
984 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
985 /* be robust against wrong usage ... */
986 msg_head->flags |= RX_FILTER_ID;
987 /* ignore trailing garbage */
988 msg_head->nframes = 0;
991 if ((msg_head->flags & RX_RTR_FRAME) &&
992 ((msg_head->nframes != 1) ||
993 (!(msg_head->can_id & CAN_RTR_FLAG))))
996 /* check the given can_id */
997 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
999 /* update existing BCM operation */
1002 * Do we need more space for the can_frames than currently
1003 * allocated? -> This is a _really_ unusual use-case and
1004 * therefore (complexity / locking) it is not supported.
1006 if (msg_head->nframes > op->nframes)
1009 if (msg_head->nframes) {
1010 /* update can_frames content */
1011 err = memcpy_fromiovec((u8 *)op->frames,
1013 msg_head->nframes * CFSIZ);
1017 /* clear last_frames to indicate 'nothing received' */
1018 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1021 op->nframes = msg_head->nframes;
1023 /* Only an update -> do not call can_rx_register() */
1027 /* insert new BCM operation for the given can_id */
1028 op = kzalloc(OPSIZ, GFP_KERNEL);
1032 op->can_id = msg_head->can_id;
1033 op->nframes = msg_head->nframes;
1035 if (msg_head->nframes > 1) {
1036 /* create array for can_frames and copy the data */
1037 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1044 /* create and init array for received can_frames */
1045 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1047 if (!op->last_frames) {
1054 op->frames = &op->sframe;
1055 op->last_frames = &op->last_sframe;
1058 if (msg_head->nframes) {
1059 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1060 msg_head->nframes * CFSIZ);
1062 if (op->frames != &op->sframe)
1064 if (op->last_frames != &op->last_sframe)
1065 kfree(op->last_frames);
1071 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1073 op->ifindex = ifindex;
1075 /* initialize uninitialized (kzalloc) structure */
1076 setup_timer(&op->timer, bcm_rx_timeout_handler,
1079 /* init throttle timer for RX_CHANGED */
1080 setup_timer(&op->thrtimer, bcm_rx_thr_handler,
1083 /* mark disabled timer */
1084 op->thrtimer.expires = 0;
1086 /* add this bcm_op to the list of the rx_ops */
1087 list_add(&op->list, &bo->rx_ops);
1089 /* call can_rx_register() */
1092 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1095 op->flags = msg_head->flags;
1097 if (op->flags & RX_RTR_FRAME) {
1099 /* no timers in RTR-mode */
1100 del_timer(&op->thrtimer);
1101 del_timer(&op->timer);
1104 * funny feature in RX(!)_SETUP only for RTR-mode:
1105 * copy can_id into frame BUT without RTR-flag to
1106 * prevent a full-load-loopback-test ... ;-]
1108 if ((op->flags & TX_CP_CAN_ID) ||
1109 (op->frames[0].can_id == op->can_id))
1110 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1113 if (op->flags & SETTIMER) {
1115 /* set timer value */
1116 op->ival1 = msg_head->ival1;
1117 op->ival2 = msg_head->ival2;
1118 op->j_ival1 = rounded_tv2jif(&msg_head->ival1);
1119 op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
1121 /* disable an active timer due to zero value? */
1123 del_timer(&op->timer);
1126 * In any case cancel the throttle timer, flush
1127 * potentially blocked msgs and reset throttle handling
1129 del_timer(&op->thrtimer);
1130 bcm_rx_thr_flush(op);
1131 op->thrtimer.expires = 0;
1134 if ((op->flags & STARTTIMER) && op->j_ival1)
1135 mod_timer(&op->timer, jiffies + op->j_ival1);
1138 /* now we can register for can_ids, if we added a new bcm_op */
1139 if (do_rx_register) {
1141 struct net_device *dev;
1143 dev = dev_get_by_index(&init_net, ifindex);
1145 err = can_rx_register(dev, op->can_id,
1146 REGMASK(op->can_id),
1150 op->rx_reg_dev = dev;
1155 err = can_rx_register(NULL, op->can_id,
1156 REGMASK(op->can_id),
1157 bcm_rx_handler, op, "bcm");
1159 /* this bcm rx op is broken -> remove it */
1160 list_del(&op->list);
1166 return msg_head->nframes * CFSIZ + MHSIZ;
1170 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1172 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1174 struct sk_buff *skb;
1175 struct net_device *dev;
1178 /* we need a real device to send frames */
1182 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1187 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1193 dev = dev_get_by_index(&init_net, ifindex);
1201 err = can_send(skb, 1); /* send with loopback */
1207 return CFSIZ + MHSIZ;
1211 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1213 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1214 struct msghdr *msg, size_t size)
1216 struct sock *sk = sock->sk;
1217 struct bcm_sock *bo = bcm_sk(sk);
1218 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1219 struct bcm_msg_head msg_head;
1220 int ret; /* read bytes or error codes as return value */
1225 /* check for valid message length from userspace */
1226 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1229 /* check for alternative ifindex for this bcm_op */
1231 if (!ifindex && msg->msg_name) {
1232 /* no bound device as default => check msg_name */
1233 struct sockaddr_can *addr =
1234 (struct sockaddr_can *)msg->msg_name;
1236 if (addr->can_family != AF_CAN)
1239 /* ifindex from sendto() */
1240 ifindex = addr->can_ifindex;
1243 struct net_device *dev;
1245 dev = dev_get_by_index(&init_net, ifindex);
1249 if (dev->type != ARPHRD_CAN) {
1258 /* read message head information */
1260 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1266 switch (msg_head.opcode) {
1269 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1273 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1277 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1284 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1291 /* reuse msg_head for the reply to TX_READ */
1292 msg_head.opcode = TX_STATUS;
1293 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1297 /* reuse msg_head for the reply to RX_READ */
1298 msg_head.opcode = RX_STATUS;
1299 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1303 /* we need exactly one can_frame behind the msg head */
1304 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1307 ret = bcm_tx_send(msg, ifindex, sk);
1321 * notification handler for netdevice status changes
1323 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1326 struct net_device *dev = (struct net_device *)data;
1327 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1328 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
1329 struct sock *sk = &bo->sk;
1331 struct sock *sk = bo->sk;
1334 int notify_enodev = 0;
1336 if (dev->type != ARPHRD_CAN)
1341 case NETDEV_UNREGISTER:
1344 /* remove device specific receive entries */
1345 list_for_each_entry(op, &bo->rx_ops, list)
1346 if (op->rx_reg_dev == dev)
1347 bcm_rx_unreg(dev, op);
1349 /* remove device reference, if this is our bound device */
1350 if (bo->bound && bo->ifindex == dev->ifindex) {
1358 if (notify_enodev) {
1359 sk->sk_err = ENODEV;
1360 if (!sock_flag(sk, SOCK_DEAD))
1361 sk->sk_error_report(sk);
1366 if (bo->bound && bo->ifindex == dev->ifindex) {
1367 sk->sk_err = ENETDOWN;
1368 if (!sock_flag(sk, SOCK_DEAD))
1369 sk->sk_error_report(sk);
1377 * initial settings for all BCM sockets to be set at socket creation time
1379 static int bcm_init(struct sock *sk)
1381 struct bcm_sock *bo = bcm_sk(sk);
1383 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
1388 bo->dropped_usr_msgs = 0;
1389 bo->bcm_proc_read = NULL;
1391 INIT_LIST_HEAD(&bo->tx_ops);
1392 INIT_LIST_HEAD(&bo->rx_ops);
1395 bo->notifier.notifier_call = bcm_notifier;
1397 register_netdevice_notifier(&bo->notifier);
1403 * standard socket functions
1405 static int bcm_release(struct socket *sock)
1407 struct sock *sk = sock->sk;
1408 struct bcm_sock *bo = bcm_sk(sk);
1409 struct bcm_op *op, *next;
1411 /* remove bcm_ops, timer, rx_unregister(), etc. */
1413 unregister_netdevice_notifier(&bo->notifier);
1417 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1420 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1422 * Don't care if we're bound or not (due to netdev problems)
1423 * can_rx_unregister() is always a save thing to do here.
1427 * Only remove subscriptions that had not
1428 * been removed due to NETDEV_UNREGISTER
1431 if (op->rx_reg_dev) {
1432 struct net_device *dev;
1434 dev = dev_get_by_index(&init_net, op->ifindex);
1436 bcm_rx_unreg(dev, op);
1441 can_rx_unregister(NULL, op->can_id,
1442 REGMASK(op->can_id),
1443 bcm_rx_handler, op);
1448 /* remove procfs entry */
1449 if (proc_dir && bo->bcm_proc_read)
1450 remove_proc_entry(bo->procname, proc_dir);
1452 /* remove device reference */
1464 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1467 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1468 struct sock *sk = sock->sk;
1469 struct bcm_sock *bo = bcm_sk(sk);
1474 /* bind a device to this socket */
1475 if (addr->can_ifindex) {
1476 struct net_device *dev;
1478 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1482 if (dev->type != ARPHRD_CAN) {
1487 bo->ifindex = dev->ifindex;
1491 /* no interface reference for ifindex = 0 ('any' CAN device) */
1498 /* unique socket address as filename */
1499 sprintf(bo->procname, "%p", sock);
1500 bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644,
1508 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1509 struct msghdr *msg, size_t size, int flags)
1511 struct sock *sk = sock->sk;
1512 struct sk_buff *skb;
1517 noblock = flags & MSG_DONTWAIT;
1518 flags &= ~MSG_DONTWAIT;
1519 skb = skb_recv_datagram(sk, flags, noblock, &error);
1523 if (skb->len < size)
1526 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1528 skb_free_datagram(sk, skb);
1532 sock_recv_timestamp(msg, sk, skb);
1534 if (msg->msg_name) {
1535 msg->msg_namelen = sizeof(struct sockaddr_can);
1536 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1539 skb_free_datagram(sk, skb);
1544 static struct proto_ops bcm_ops __read_mostly = {
1546 .release = bcm_release,
1547 .bind = sock_no_bind,
1548 .connect = bcm_connect,
1549 .socketpair = sock_no_socketpair,
1550 .accept = sock_no_accept,
1551 .getname = sock_no_getname,
1552 .poll = datagram_poll,
1553 .ioctl = NULL, /* use can_ioctl() from af_can.c */
1554 .listen = sock_no_listen,
1555 .shutdown = sock_no_shutdown,
1556 .setsockopt = sock_no_setsockopt,
1557 .getsockopt = sock_no_getsockopt,
1558 .sendmsg = bcm_sendmsg,
1559 .recvmsg = bcm_recvmsg,
1560 .mmap = sock_no_mmap,
1561 .sendpage = sock_no_sendpage,
1564 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
1565 static struct proto bcm_proto __read_mostly = {
1567 .owner = THIS_MODULE,
1568 .obj_size = sizeof(struct bcm_sock),
1572 static struct can_proto bcm_can_proto __read_mostly = {
1574 .protocol = CAN_BCM,
1580 static struct can_proto bcm_can_proto __read_mostly = {
1582 .protocol = CAN_BCM,
1585 .owner = THIS_MODULE,
1586 .obj_size = sizeof(struct bcm_sock),
1591 static int __init bcm_module_init(void)
1597 err = can_proto_register(&bcm_can_proto);
1599 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1603 /* create /proc/net/can-bcm directory */
1604 proc_dir = proc_mkdir("can-bcm", proc_net);
1607 proc_dir->owner = THIS_MODULE;
1612 static void __exit bcm_module_exit(void)
1614 can_proto_unregister(&bcm_can_proto);
1617 proc_net_remove("can-bcm");
1620 module_init(bcm_module_init);
1621 module_exit(bcm_module_exit);