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 /* easy access to can_frame payload */
83 static inline u64 GET_U64(const struct can_frame *cp)
85 return *(u64 *)cp->data;
89 struct list_head list;
93 unsigned long frames_abs, frames_filtered;
94 struct timeval ival1, ival2;
95 struct timer_list timer, thrtimer;
96 struct timeval rx_stamp;
97 unsigned long j_ival1, j_ival2, j_lastmsg;
102 struct can_frame *frames;
103 struct can_frame *last_frames;
104 struct can_frame sframe;
105 struct can_frame last_sframe;
107 struct net_device *rx_reg_dev;
110 static struct proc_dir_entry *proc_dir;
113 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
120 struct notifier_block notifier;
121 struct list_head rx_ops;
122 struct list_head tx_ops;
123 unsigned long dropped_usr_msgs;
124 struct proc_dir_entry *bcm_proc_read;
125 char procname [9]; /* pointer printed in ASCII with \0 */
128 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
130 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
131 return (struct bcm_sock *)sk;
133 return (struct bcm_sock *)sk->sk_protinfo;
137 #define CFSIZ sizeof(struct can_frame)
138 #define OPSIZ sizeof(struct bcm_op)
139 #define MHSIZ sizeof(struct bcm_msg_head)
142 * rounded_tv2jif - calculate jiffies from timeval including optional up
143 * @tv: pointer to timeval
146 * Unlike timeval_to_jiffies() provided in include/linux/jiffies.h, this
147 * function is intentionally more relaxed on precise timer ticks to get
148 * exact one jiffy for requested 1000us on a 1000HZ machine.
149 * This code is to be removed when upgrading to kernel hrtimer.
152 * calculated jiffies (max: ULONG_MAX)
154 static unsigned long rounded_tv2jif(const struct timeval *tv)
156 unsigned long sec = tv->tv_sec;
157 unsigned long usec = tv->tv_usec;
160 if (sec > ULONG_MAX / HZ)
163 /* round up to get at least the requested time */
164 usec += 1000000 / HZ - 1;
166 jif = usec / (1000000 / HZ);
168 if (sec * HZ > ULONG_MAX - jif)
171 return jif + sec * HZ;
177 static char *bcm_proc_getifname(int ifindex)
179 struct net_device *dev;
184 /* no usage counting */
185 dev = __dev_get_by_index(&init_net, ifindex);
192 static int bcm_read_proc(char *page, char **start, off_t off,
193 int count, int *eof, void *data)
196 struct sock *sk = (struct sock *)data;
197 struct bcm_sock *bo = bcm_sk(sk);
200 len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p",
202 len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk);
203 len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo);
204 len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu",
205 bo->dropped_usr_msgs);
206 len += snprintf(page + len, PAGE_SIZE - len, " / bound %s",
207 bcm_proc_getifname(bo->ifindex));
208 len += snprintf(page + len, PAGE_SIZE - len, " <<<\n");
210 list_for_each_entry(op, &bo->rx_ops, list) {
212 unsigned long reduction;
214 /* print only active entries & prevent division by zero */
218 len += snprintf(page + len, PAGE_SIZE - len,
220 op->can_id, bcm_proc_getifname(op->ifindex));
221 len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ",
223 (op->flags & RX_CHECK_DLC)?'d':' ');
225 len += snprintf(page + len, PAGE_SIZE - len,
226 "timeo=%ld ", op->j_ival1);
229 len += snprintf(page + len, PAGE_SIZE - len,
230 "thr=%ld ", op->j_ival2);
232 len += snprintf(page + len, PAGE_SIZE - len,
233 "# recv %ld (%ld) => reduction: ",
234 op->frames_filtered, op->frames_abs);
236 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
238 len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n",
239 (reduction == 100)?"near ":"", reduction);
241 if (len > PAGE_SIZE - 200) {
242 /* mark output cut off */
243 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
248 list_for_each_entry(op, &bo->tx_ops, list) {
250 len += snprintf(page + len, PAGE_SIZE - len,
251 "tx_op: %03X %s [%d] ",
252 op->can_id, bcm_proc_getifname(op->ifindex),
256 len += snprintf(page + len, PAGE_SIZE - len, "t1=%ld ",
260 len += snprintf(page + len, PAGE_SIZE - len, "t2=%ld ",
263 len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n",
266 if (len > PAGE_SIZE - 100) {
267 /* mark output cut off */
268 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
273 len += snprintf(page + len, PAGE_SIZE - len, "\n");
280 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
281 * of the given bcm tx op
283 static void bcm_can_tx(struct bcm_op *op)
286 struct net_device *dev;
287 struct can_frame *cf = &op->frames[op->currframe];
289 /* no target device? => exit */
293 dev = dev_get_by_index(&init_net, op->ifindex);
295 /* RFC: should this bcm_op remove itself here? */
299 skb = alloc_skb(CFSIZ, gfp_any());
303 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
305 /* send with loopback */
310 /* update statistics */
314 /* reached last frame? */
315 if (op->currframe >= op->nframes)
322 * bcm_send_to_user - send a BCM message to the userspace
323 * (consisting of bcm_msg_head + x CAN frames)
325 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
326 struct can_frame *frames, int has_timestamp)
329 struct can_frame *firstframe;
330 struct sockaddr_can *addr;
331 struct sock *sk = op->sk;
332 int datalen = head->nframes * CFSIZ;
335 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
339 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
342 /* can_frames starting here */
343 firstframe = (struct can_frame *)skb->tail;
345 memcpy(skb_put(skb, datalen), frames, datalen);
348 * the BCM uses the can_dlc-element of the can_frame
349 * structure for internal purposes. This is only
350 * relevant for updates that are generated by the
351 * BCM, where nframes is 1
353 if (head->nframes == 1)
354 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
358 /* restore rx timestamp */
359 skb_set_timestamp(skb, &op->rx_stamp);
363 * Put the datagram to the queue so that bcm_recvmsg() can
364 * get it from there. We need to pass the interface index to
365 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
366 * containing the interface index.
369 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
370 addr = (struct sockaddr_can *)skb->cb;
371 memset(addr, 0, sizeof(*addr));
372 addr->can_family = AF_CAN;
373 addr->can_ifindex = op->rx_ifindex;
375 err = sock_queue_rcv_skb(sk, skb);
377 struct bcm_sock *bo = bcm_sk(sk);
380 /* don't care about overflows in this statistic */
381 bo->dropped_usr_msgs++;
386 * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
388 static void bcm_tx_timeout_handler(unsigned long data)
390 struct bcm_op *op = (struct bcm_op *)data;
392 if (op->j_ival1 && (op->count > 0)) {
395 if (!op->count && (op->flags & TX_COUNTEVT)) {
396 struct bcm_msg_head msg_head;
398 /* create notification to user */
399 msg_head.opcode = TX_EXPIRED;
400 msg_head.flags = op->flags;
401 msg_head.count = op->count;
402 msg_head.ival1 = op->ival1;
403 msg_head.ival2 = op->ival2;
404 msg_head.can_id = op->can_id;
405 msg_head.nframes = 0;
407 bcm_send_to_user(op, &msg_head, NULL, 0);
411 if (op->j_ival1 && (op->count > 0)) {
413 /* send (next) frame */
415 mod_timer(&op->timer, jiffies + op->j_ival1);
420 /* send (next) frame */
422 mod_timer(&op->timer, jiffies + op->j_ival2);
430 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
432 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
434 struct bcm_msg_head head;
436 op->j_lastmsg = jiffies;
438 /* update statistics */
439 op->frames_filtered++;
441 /* prevent statistics overflow */
442 if (op->frames_filtered > ULONG_MAX/100)
443 op->frames_filtered = op->frames_abs = 0;
445 head.opcode = RX_CHANGED;
446 head.flags = op->flags;
447 head.count = op->count;
448 head.ival1 = op->ival1;
449 head.ival2 = op->ival2;
450 head.can_id = op->can_id;
453 bcm_send_to_user(op, &head, data, 1);
457 * bcm_rx_update_and_send - process a detected relevant receive content change
458 * 1. update the last received data
459 * 2. send a notification to the user (if possible)
461 static void bcm_rx_update_and_send(struct bcm_op *op,
462 struct can_frame *lastdata,
463 struct can_frame *rxdata)
465 unsigned long nexttx = op->j_lastmsg + op->j_ival2;
467 memcpy(lastdata, rxdata, CFSIZ);
470 lastdata->can_dlc |= RX_RECV;
472 /* throttle bcm_rx_changed ? */
473 if ((op->thrtimer.expires) ||
474 ((op->j_ival2) && (nexttx > jiffies))) {
475 /* we are already waiting OR we have to start waiting */
477 /* mark as 'throttled' */
478 lastdata->can_dlc |= RX_THR;
480 if (!(op->thrtimer.expires)) {
481 /* start the timer only the first time */
482 mod_timer(&op->thrtimer, nexttx);
486 /* send RX_CHANGED to the user immediately */
487 bcm_rx_changed(op, rxdata);
492 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
493 * received data stored in op->last_frames[]
495 static void bcm_rx_cmp_to_index(struct bcm_op *op, int index,
496 struct can_frame *rxdata)
499 * no one uses the MSBs of can_dlc for comparation,
500 * so we use it here to detect the first time of reception
503 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
504 /* received data for the first time => send update to user */
505 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
509 /* do a real check in can_frame data section */
511 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
512 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
513 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
517 if (op->flags & RX_CHECK_DLC) {
518 /* do a real check in can_frame dlc */
519 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
521 bcm_rx_update_and_send(op, &op->last_frames[index],
529 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
531 static void bcm_rx_starttimer(struct bcm_op *op)
533 if (op->flags & RX_NO_AUTOTIMER)
537 mod_timer(&op->timer, jiffies + op->j_ival1);
541 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
543 static void bcm_rx_timeout_handler(unsigned long data)
545 struct bcm_op *op = (struct bcm_op *)data;
546 struct bcm_msg_head msg_head;
548 msg_head.opcode = RX_TIMEOUT;
549 msg_head.flags = op->flags;
550 msg_head.count = op->count;
551 msg_head.ival1 = op->ival1;
552 msg_head.ival2 = op->ival2;
553 msg_head.can_id = op->can_id;
554 msg_head.nframes = 0;
556 bcm_send_to_user(op, &msg_head, NULL, 0);
558 /* no restart of the timer is done here! */
560 /* if user wants to be informed, when cyclic CAN-Messages come back */
561 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
562 /* clear received can_frames to indicate 'nothing received' */
563 memset(op->last_frames, 0, op->nframes * CFSIZ);
568 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
570 static int bcm_rx_thr_flush(struct bcm_op *op)
574 if (op->nframes > 1) {
577 /* for MUX filter we start at index 1 */
578 for (i = 1; i < op->nframes; i++) {
579 if ((op->last_frames) &&
580 (op->last_frames[i].can_dlc & RX_THR)) {
581 op->last_frames[i].can_dlc &= ~RX_THR;
582 bcm_rx_changed(op, &op->last_frames[i]);
588 /* for RX_FILTER_ID and simple filter */
589 if (op->last_frames && (op->last_frames[0].can_dlc & RX_THR)) {
590 op->last_frames[0].can_dlc &= ~RX_THR;
591 bcm_rx_changed(op, &op->last_frames[0]);
600 * bcm_rx_thr_handler - the time for blocked content updates is over now:
601 * Check for throttled data and send it to the userspace
603 static void bcm_rx_thr_handler(unsigned long data)
605 struct bcm_op *op = (struct bcm_op *)data;
607 if (bcm_rx_thr_flush(op))
608 mod_timer(&op->thrtimer, jiffies + op->j_ival2);
610 /* mark disabled / consumed timer */
611 op->thrtimer.expires = 0;
616 * bcm_rx_handler - handle a CAN frame receiption
618 static void bcm_rx_handler(struct sk_buff *skb, void *data)
620 struct bcm_op *op = (struct bcm_op *)data;
621 struct can_frame rxframe;
624 /* disable timeout */
625 del_timer(&op->timer);
627 if (skb->len == sizeof(rxframe)) {
628 memcpy(&rxframe, skb->data, sizeof(rxframe));
629 /* save rx timestamp */
630 skb_get_timestamp(skb, &op->rx_stamp);
631 /* save originator for recvfrom() */
632 op->rx_ifindex = skb->dev->ifindex;
633 /* update statistics */
642 if (op->can_id != rxframe.can_id)
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);
654 bcm_rx_starttimer(op);
658 if (op->nframes == 1) {
659 /* simple compare with index 0 */
660 bcm_rx_cmp_to_index(op, 0, &rxframe);
661 bcm_rx_starttimer(op);
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);
681 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 if (op->j_ival1 && (op->count > 0)) {
959 /* op->count-- is done in bcm_tx_timeout_handler */
960 mod_timer(&op->timer, jiffies + op->j_ival1);
962 mod_timer(&op->timer, jiffies + op->j_ival2);
965 if (op->flags & TX_ANNOUNCE)
968 return msg_head->nframes * CFSIZ + MHSIZ;
972 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
974 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
975 int ifindex, struct sock *sk)
977 struct bcm_sock *bo = bcm_sk(sk);
982 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
983 /* be robust against wrong usage ... */
984 msg_head->flags |= RX_FILTER_ID;
985 /* ignore trailing garbage */
986 msg_head->nframes = 0;
989 if ((msg_head->flags & RX_RTR_FRAME) &&
990 ((msg_head->nframes != 1) ||
991 (!(msg_head->can_id & CAN_RTR_FLAG))))
994 /* check the given can_id */
995 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
997 /* update existing BCM operation */
1000 * Do we need more space for the can_frames than currently
1001 * allocated? -> This is a _really_ unusual use-case and
1002 * therefore (complexity / locking) it is not supported.
1004 if (msg_head->nframes > op->nframes)
1007 if (msg_head->nframes) {
1008 /* update can_frames content */
1009 err = memcpy_fromiovec((u8 *)op->frames,
1011 msg_head->nframes * CFSIZ);
1015 /* clear last_frames to indicate 'nothing received' */
1016 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1019 op->nframes = msg_head->nframes;
1021 /* Only an update -> do not call can_rx_register() */
1025 /* insert new BCM operation for the given can_id */
1026 op = kzalloc(OPSIZ, GFP_KERNEL);
1030 op->can_id = msg_head->can_id;
1031 op->nframes = msg_head->nframes;
1033 if (msg_head->nframes > 1) {
1034 /* create array for can_frames and copy the data */
1035 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1042 /* create and init array for received can_frames */
1043 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1045 if (!op->last_frames) {
1052 op->frames = &op->sframe;
1053 op->last_frames = &op->last_sframe;
1056 if (msg_head->nframes) {
1057 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1058 msg_head->nframes * CFSIZ);
1060 if (op->frames != &op->sframe)
1062 if (op->last_frames != &op->last_sframe)
1063 kfree(op->last_frames);
1069 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1071 op->ifindex = ifindex;
1073 /* initialize uninitialized (kzalloc) structure */
1074 setup_timer(&op->timer, bcm_rx_timeout_handler,
1077 /* init throttle timer for RX_CHANGED */
1078 setup_timer(&op->thrtimer, bcm_rx_thr_handler,
1081 /* mark disabled timer */
1082 op->thrtimer.expires = 0;
1084 /* add this bcm_op to the list of the rx_ops */
1085 list_add(&op->list, &bo->rx_ops);
1087 /* call can_rx_register() */
1090 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1093 op->flags = msg_head->flags;
1095 if (op->flags & RX_RTR_FRAME) {
1097 /* no timers in RTR-mode */
1098 del_timer(&op->thrtimer);
1099 del_timer(&op->timer);
1102 * funny feature in RX(!)_SETUP only for RTR-mode:
1103 * copy can_id into frame BUT without RTR-flag to
1104 * prevent a full-load-loopback-test ... ;-]
1106 if ((op->flags & TX_CP_CAN_ID) ||
1107 (op->frames[0].can_id == op->can_id))
1108 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1111 if (op->flags & SETTIMER) {
1113 /* set timer value */
1114 op->ival1 = msg_head->ival1;
1115 op->ival2 = msg_head->ival2;
1116 op->j_ival1 = rounded_tv2jif(&msg_head->ival1);
1117 op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
1119 /* disable an active timer due to zero value? */
1121 del_timer(&op->timer);
1124 * In any case cancel the throttle timer, flush
1125 * potentially blocked msgs and reset throttle handling
1127 del_timer(&op->thrtimer);
1128 bcm_rx_thr_flush(op);
1129 op->thrtimer.expires = 0;
1132 if ((op->flags & STARTTIMER) && op->j_ival1)
1133 mod_timer(&op->timer, jiffies + op->j_ival1);
1136 /* now we can register for can_ids, if we added a new bcm_op */
1137 if (do_rx_register) {
1139 struct net_device *dev;
1141 dev = dev_get_by_index(&init_net, ifindex);
1143 err = can_rx_register(dev, op->can_id,
1144 REGMASK(op->can_id),
1148 op->rx_reg_dev = dev;
1153 err = can_rx_register(NULL, op->can_id,
1154 REGMASK(op->can_id),
1155 bcm_rx_handler, op, "bcm");
1157 /* this bcm rx op is broken -> remove it */
1158 list_del(&op->list);
1164 return msg_head->nframes * CFSIZ + MHSIZ;
1168 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1170 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1172 struct sk_buff *skb;
1173 struct net_device *dev;
1176 /* we need a real device to send frames */
1180 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1185 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1191 dev = dev_get_by_index(&init_net, ifindex);
1199 err = can_send(skb, 1); /* send with loopback */
1205 return CFSIZ + MHSIZ;
1209 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1211 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1212 struct msghdr *msg, size_t size)
1214 struct sock *sk = sock->sk;
1215 struct bcm_sock *bo = bcm_sk(sk);
1216 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1217 struct bcm_msg_head msg_head;
1218 int ret; /* read bytes or error codes as return value */
1223 /* check for valid message length from userspace */
1224 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1227 /* check for alternative ifindex for this bcm_op */
1229 if (!ifindex && msg->msg_name) {
1230 /* no bound device as default => check msg_name */
1231 struct sockaddr_can *addr =
1232 (struct sockaddr_can *)msg->msg_name;
1234 if (addr->can_family != AF_CAN)
1237 /* ifindex from sendto() */
1238 ifindex = addr->can_ifindex;
1241 struct net_device *dev;
1243 dev = dev_get_by_index(&init_net, ifindex);
1247 if (dev->type != ARPHRD_CAN) {
1256 /* read message head information */
1258 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1264 switch (msg_head.opcode) {
1267 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1271 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1275 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1282 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1289 /* reuse msg_head for the reply to TX_READ */
1290 msg_head.opcode = TX_STATUS;
1291 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1295 /* reuse msg_head for the reply to RX_READ */
1296 msg_head.opcode = RX_STATUS;
1297 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1301 /* we need exactly one can_frame behind the msg head */
1302 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1305 ret = bcm_tx_send(msg, ifindex, sk);
1319 * notification handler for netdevice status changes
1321 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1324 struct net_device *dev = (struct net_device *)data;
1325 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1326 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
1327 struct sock *sk = &bo->sk;
1329 struct sock *sk = bo->sk;
1332 int notify_enodev = 0;
1334 if (dev->type != ARPHRD_CAN)
1339 case NETDEV_UNREGISTER:
1342 /* remove device specific receive entries */
1343 list_for_each_entry(op, &bo->rx_ops, list)
1344 if (op->rx_reg_dev == dev)
1345 bcm_rx_unreg(dev, op);
1347 /* remove device reference, if this is our bound device */
1348 if (bo->bound && bo->ifindex == dev->ifindex) {
1356 if (notify_enodev) {
1357 sk->sk_err = ENODEV;
1358 if (!sock_flag(sk, SOCK_DEAD))
1359 sk->sk_error_report(sk);
1364 if (bo->bound && bo->ifindex == dev->ifindex) {
1365 sk->sk_err = ENETDOWN;
1366 if (!sock_flag(sk, SOCK_DEAD))
1367 sk->sk_error_report(sk);
1375 * initial settings for all BCM sockets to be set at socket creation time
1377 static int bcm_init(struct sock *sk)
1379 struct bcm_sock *bo = bcm_sk(sk);
1381 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
1386 bo->dropped_usr_msgs = 0;
1387 bo->bcm_proc_read = NULL;
1389 INIT_LIST_HEAD(&bo->tx_ops);
1390 INIT_LIST_HEAD(&bo->rx_ops);
1393 bo->notifier.notifier_call = bcm_notifier;
1395 register_netdevice_notifier(&bo->notifier);
1401 * standard socket functions
1403 static int bcm_release(struct socket *sock)
1405 struct sock *sk = sock->sk;
1406 struct bcm_sock *bo = bcm_sk(sk);
1407 struct bcm_op *op, *next;
1409 /* remove bcm_ops, timer, rx_unregister(), etc. */
1411 unregister_netdevice_notifier(&bo->notifier);
1415 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1418 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1420 * Don't care if we're bound or not (due to netdev problems)
1421 * can_rx_unregister() is always a save thing to do here.
1425 * Only remove subscriptions that had not
1426 * been removed due to NETDEV_UNREGISTER
1429 if (op->rx_reg_dev) {
1430 struct net_device *dev;
1432 dev = dev_get_by_index(&init_net, op->ifindex);
1434 bcm_rx_unreg(dev, op);
1439 can_rx_unregister(NULL, op->can_id,
1440 REGMASK(op->can_id),
1441 bcm_rx_handler, op);
1446 /* remove procfs entry */
1447 if (proc_dir && bo->bcm_proc_read)
1448 remove_proc_entry(bo->procname, proc_dir);
1450 /* remove device reference */
1462 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1465 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1466 struct sock *sk = sock->sk;
1467 struct bcm_sock *bo = bcm_sk(sk);
1472 /* bind a device to this socket */
1473 if (addr->can_ifindex) {
1474 struct net_device *dev;
1476 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1480 if (dev->type != ARPHRD_CAN) {
1485 bo->ifindex = dev->ifindex;
1489 /* no interface reference for ifindex = 0 ('any' CAN device) */
1496 /* unique socket address as filename */
1497 sprintf(bo->procname, "%p", sock);
1498 bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644,
1506 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1507 struct msghdr *msg, size_t size, int flags)
1509 struct sock *sk = sock->sk;
1510 struct sk_buff *skb;
1515 noblock = flags & MSG_DONTWAIT;
1516 flags &= ~MSG_DONTWAIT;
1517 skb = skb_recv_datagram(sk, flags, noblock, &error);
1521 if (skb->len < size)
1524 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1526 skb_free_datagram(sk, skb);
1530 sock_recv_timestamp(msg, sk, skb);
1532 if (msg->msg_name) {
1533 msg->msg_namelen = sizeof(struct sockaddr_can);
1534 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1537 skb_free_datagram(sk, skb);
1542 static struct proto_ops bcm_ops __read_mostly = {
1544 .release = bcm_release,
1545 .bind = sock_no_bind,
1546 .connect = bcm_connect,
1547 .socketpair = sock_no_socketpair,
1548 .accept = sock_no_accept,
1549 .getname = sock_no_getname,
1550 .poll = datagram_poll,
1551 .ioctl = NULL, /* use can_ioctl() from af_can.c */
1552 .listen = sock_no_listen,
1553 .shutdown = sock_no_shutdown,
1554 .setsockopt = sock_no_setsockopt,
1555 .getsockopt = sock_no_getsockopt,
1556 .sendmsg = bcm_sendmsg,
1557 .recvmsg = bcm_recvmsg,
1558 .mmap = sock_no_mmap,
1559 .sendpage = sock_no_sendpage,
1562 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
1563 static struct proto bcm_proto __read_mostly = {
1565 .owner = THIS_MODULE,
1566 .obj_size = sizeof(struct bcm_sock),
1570 static struct can_proto bcm_can_proto __read_mostly = {
1572 .protocol = CAN_BCM,
1578 static struct can_proto bcm_can_proto __read_mostly = {
1580 .protocol = CAN_BCM,
1583 .owner = THIS_MODULE,
1584 .obj_size = sizeof(struct bcm_sock),
1589 static int __init bcm_module_init(void)
1595 err = can_proto_register(&bcm_can_proto);
1597 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1601 /* create /proc/net/can-bcm directory */
1602 proc_dir = proc_mkdir("can-bcm", proc_net);
1605 proc_dir->owner = THIS_MODULE;
1610 static void __exit bcm_module_exit(void)
1612 can_proto_unregister(&bcm_can_proto);
1615 proc_net_remove("can-bcm");
1618 module_init(bcm_module_init);
1619 module_exit(bcm_module_exit);