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/interrupt.h>
48 #include <linux/hrtimer.h>
49 #include <linux/list.h>
50 #include <linux/proc_fs.h>
51 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
52 #include <linux/seq_file.h>
54 #include <linux/uio.h>
55 #include <linux/net.h>
56 #include <linux/netdevice.h>
57 #include <linux/socket.h>
58 #include <linux/if_arp.h>
59 #include <linux/skbuff.h>
60 #include <socketcan/can.h>
61 #include <socketcan/can/core.h>
62 #include <socketcan/can/bcm.h>
64 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
65 #include <net/net_namespace.h>
67 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
71 #include <socketcan/can/version.h> /* for RCSID. Removed by mkpatch script */
75 * To send multiple CAN frame content within TX_SETUP or to filter
76 * CAN messages with multiplex index within RX_SETUP, the number of
77 * different filters is limited to 256 due to the one byte index value.
79 #define MAX_NFRAMES 256
81 /* use of last_frames[index].can_dlc */
82 #define RX_RECV 0x40 /* received data for this element */
83 #define RX_THR 0x80 /* element not been sent due to throttle feature */
84 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
86 /* get best masking value for can_rx_register() for a given single can_id */
87 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
88 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
89 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
91 #define CAN_BCM_VERSION CAN_VERSION
92 static __initdata const char banner[] = KERN_INFO
93 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
95 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
96 MODULE_LICENSE("Dual BSD/GPL");
97 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
98 MODULE_ALIAS("can-proto-2");
100 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
101 #error This code only supports Kernel versions 2.6.22+
102 #error For older 2.6 Kernels please use bcm-prior-2-6-22.c instead of bcm.c
105 /* easy access to can_frame payload */
106 static inline u64 GET_U64(const struct can_frame *cp)
108 return *(u64 *)cp->data;
112 struct list_head list;
116 unsigned long frames_abs, frames_filtered;
117 struct timeval ival1, ival2;
118 struct hrtimer timer, thrtimer;
119 struct tasklet_struct tsklet, thrtsklet;
120 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
125 struct can_frame *frames;
126 struct can_frame *last_frames;
127 struct can_frame sframe;
128 struct can_frame last_sframe;
130 struct net_device *rx_reg_dev;
133 static struct proc_dir_entry *proc_dir;
139 struct notifier_block notifier;
140 struct list_head rx_ops;
141 struct list_head tx_ops;
142 unsigned long dropped_usr_msgs;
143 struct proc_dir_entry *bcm_proc_read;
144 char procname [32]; /* inode number in decimal with \0 */
147 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
149 return (struct bcm_sock *)sk;
152 #define CFSIZ sizeof(struct can_frame)
153 #define OPSIZ sizeof(struct bcm_op)
154 #define MHSIZ sizeof(struct bcm_msg_head)
159 static char *bcm_proc_getifname(char *result, int ifindex)
161 struct net_device *dev;
166 read_lock(&dev_base_lock);
167 dev = __dev_get_by_index(&init_net, ifindex);
169 strcpy(result, dev->name);
171 strcpy(result, "???");
172 read_unlock(&dev_base_lock);
177 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
178 static int bcm_proc_show(struct seq_file *m, void *v)
180 char ifname[IFNAMSIZ];
181 struct sock *sk = (struct sock *)m->private;
182 struct bcm_sock *bo = bcm_sk(sk);
185 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,0,0)
186 seq_printf(m, ">>> socket %p", sk->sk_socket);
187 seq_printf(m, " / sk %p", sk);
188 seq_printf(m, " / bo %p", bo);
190 seq_printf(m, ">>> socket %pK", sk->sk_socket);
191 seq_printf(m, " / sk %pK", sk);
192 seq_printf(m, " / bo %pK", bo);
194 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
195 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
196 seq_printf(m, " <<<\n");
198 list_for_each_entry(op, &bo->rx_ops, list) {
200 unsigned long reduction;
202 /* print only active entries & prevent division by zero */
206 seq_printf(m, "rx_op: %03X %-5s ",
207 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
208 seq_printf(m, "[%u]%c ", op->nframes,
209 (op->flags & RX_CHECK_DLC)?'d':' ');
210 if (op->kt_ival1.tv64)
211 seq_printf(m, "timeo=%lld ",
213 ktime_to_us(op->kt_ival1));
215 if (op->kt_ival2.tv64)
216 seq_printf(m, "thr=%lld ",
218 ktime_to_us(op->kt_ival2));
220 seq_printf(m, "# recv %ld (%ld) => reduction: ",
221 op->frames_filtered, op->frames_abs);
223 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
225 seq_printf(m, "%s%ld%%\n",
226 (reduction == 100)?"near ":"", reduction);
229 list_for_each_entry(op, &bo->tx_ops, list) {
231 seq_printf(m, "tx_op: %03X %s [%u] ",
233 bcm_proc_getifname(ifname, op->ifindex),
236 if (op->kt_ival1.tv64)
237 seq_printf(m, "t1=%lld ",
238 (long long) ktime_to_us(op->kt_ival1));
240 if (op->kt_ival2.tv64)
241 seq_printf(m, "t2=%lld ",
242 (long long) ktime_to_us(op->kt_ival2));
244 seq_printf(m, "# sent %ld\n", op->frames_abs);
250 static int bcm_proc_open(struct inode *inode, struct file *file)
252 return single_open(file, bcm_proc_show, PDE(inode)->data);
255 static const struct file_operations bcm_proc_fops = {
256 .owner = THIS_MODULE,
257 .open = bcm_proc_open,
260 .release = single_release,
263 static int bcm_read_proc(char *page, char **start, off_t off,
264 int count, int *eof, void *data)
266 char ifname[IFNAMSIZ];
268 struct sock *sk = (struct sock *)data;
269 struct bcm_sock *bo = bcm_sk(sk);
272 len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p",
274 len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk);
275 len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo);
276 len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu",
277 bo->dropped_usr_msgs);
278 len += snprintf(page + len, PAGE_SIZE - len, " / bound %s",
279 bcm_proc_getifname(ifname, bo->ifindex));
280 len += snprintf(page + len, PAGE_SIZE - len, " <<<\n");
282 list_for_each_entry(op, &bo->rx_ops, list) {
284 unsigned long reduction;
286 /* print only active entries & prevent division by zero */
290 len += snprintf(page + len, PAGE_SIZE - len,
292 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
293 len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ",
295 (op->flags & RX_CHECK_DLC)?'d':' ');
296 if (op->kt_ival1.tv64)
297 len += snprintf(page + len, PAGE_SIZE - len,
300 ktime_to_us(op->kt_ival1));
302 if (op->kt_ival2.tv64)
303 len += snprintf(page + len, PAGE_SIZE - len,
306 ktime_to_us(op->kt_ival2));
308 len += snprintf(page + len, PAGE_SIZE - len,
309 "# recv %ld (%ld) => reduction: ",
310 op->frames_filtered, op->frames_abs);
312 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
314 len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n",
315 (reduction == 100)?"near ":"", reduction);
317 if (len > PAGE_SIZE - 200) {
318 /* mark output cut off */
319 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
324 list_for_each_entry(op, &bo->tx_ops, list) {
326 len += snprintf(page + len, PAGE_SIZE - len,
327 "tx_op: %03X %s [%d] ",
329 bcm_proc_getifname(ifname, op->ifindex),
332 if (op->kt_ival1.tv64)
333 len += snprintf(page + len, PAGE_SIZE - len, "t1=%lld ",
334 (long long) ktime_to_us(op->kt_ival1));
336 if (op->kt_ival2.tv64)
337 len += snprintf(page + len, PAGE_SIZE - len, "t2=%lld ",
338 (long long) ktime_to_us(op->kt_ival2));
340 len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n",
343 if (len > PAGE_SIZE - 100) {
344 /* mark output cut off */
345 len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
350 len += snprintf(page + len, PAGE_SIZE - len, "\n");
358 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
359 * of the given bcm tx op
361 static void bcm_can_tx(struct bcm_op *op)
364 struct net_device *dev;
365 struct can_frame *cf = &op->frames[op->currframe];
367 /* no target device? => exit */
371 dev = dev_get_by_index(&init_net, op->ifindex);
373 /* RFC: should this bcm_op remove itself here? */
377 skb = alloc_skb(CFSIZ, gfp_any());
381 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
383 /* send with loopback */
388 /* update statistics */
392 /* reached last frame? */
393 if (op->currframe >= op->nframes)
400 * bcm_send_to_user - send a BCM message to the userspace
401 * (consisting of bcm_msg_head + x CAN frames)
403 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
404 struct can_frame *frames, int has_timestamp)
407 struct can_frame *firstframe;
408 struct sockaddr_can *addr;
409 struct sock *sk = op->sk;
410 unsigned int datalen = head->nframes * CFSIZ;
413 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
417 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
420 /* can_frames starting here */
421 firstframe = (struct can_frame *)skb_tail_pointer(skb);
423 memcpy(skb_put(skb, datalen), frames, datalen);
426 * the BCM uses the can_dlc-element of the can_frame
427 * structure for internal purposes. This is only
428 * relevant for updates that are generated by the
429 * BCM, where nframes is 1
431 if (head->nframes == 1)
432 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
436 /* restore rx timestamp */
437 skb->tstamp = op->rx_stamp;
441 * Put the datagram to the queue so that bcm_recvmsg() can
442 * get it from there. We need to pass the interface index to
443 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
444 * containing the interface index.
447 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
448 addr = (struct sockaddr_can *)skb->cb;
449 memset(addr, 0, sizeof(*addr));
450 addr->can_family = AF_CAN;
451 addr->can_ifindex = op->rx_ifindex;
453 err = sock_queue_rcv_skb(sk, skb);
455 struct bcm_sock *bo = bcm_sk(sk);
458 /* don't care about overflows in this statistic */
459 bo->dropped_usr_msgs++;
463 static void bcm_tx_timeout_tsklet(unsigned long data)
465 struct bcm_op *op = (struct bcm_op *)data;
466 struct bcm_msg_head msg_head;
468 if (op->kt_ival1.tv64 && (op->count > 0)) {
471 if (!op->count && (op->flags & TX_COUNTEVT)) {
473 /* create notification to user */
474 msg_head.opcode = TX_EXPIRED;
475 msg_head.flags = op->flags;
476 msg_head.count = op->count;
477 msg_head.ival1 = op->ival1;
478 msg_head.ival2 = op->ival2;
479 msg_head.can_id = op->can_id;
480 msg_head.nframes = 0;
482 bcm_send_to_user(op, &msg_head, NULL, 0);
486 if (op->kt_ival1.tv64 && (op->count > 0)) {
488 /* send (next) frame */
490 hrtimer_start(&op->timer,
491 ktime_add(ktime_get(), op->kt_ival1),
495 if (op->kt_ival2.tv64) {
497 /* send (next) frame */
499 hrtimer_start(&op->timer,
500 ktime_add(ktime_get(), op->kt_ival2),
507 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
509 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
511 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
513 tasklet_schedule(&op->tsklet);
515 return HRTIMER_NORESTART;
519 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
521 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
523 struct bcm_msg_head head;
525 /* update statistics */
526 op->frames_filtered++;
528 /* prevent statistics overflow */
529 if (op->frames_filtered > ULONG_MAX/100)
530 op->frames_filtered = op->frames_abs = 0;
532 /* this element is not throttled anymore */
533 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
535 head.opcode = RX_CHANGED;
536 head.flags = op->flags;
537 head.count = op->count;
538 head.ival1 = op->ival1;
539 head.ival2 = op->ival2;
540 head.can_id = op->can_id;
543 bcm_send_to_user(op, &head, data, 1);
546 #if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,25)
547 /* is part of linux/hrtimer.h since 2.6.26 */
548 static inline int hrtimer_callback_running(struct hrtimer *timer)
550 return timer->state & HRTIMER_STATE_CALLBACK;
553 #if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,22)
554 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
556 return ktime_to_us(ktime_sub(later, earlier));
560 * bcm_rx_update_and_send - process a detected relevant receive content change
561 * 1. update the last received data
562 * 2. send a notification to the user (if possible)
564 static void bcm_rx_update_and_send(struct bcm_op *op,
565 struct can_frame *lastdata,
566 const struct can_frame *rxdata)
568 memcpy(lastdata, rxdata, CFSIZ);
570 /* mark as used and throttled by default */
571 lastdata->can_dlc |= (RX_RECV|RX_THR);
573 /* throtteling mode inactive ? */
574 if (!op->kt_ival2.tv64) {
575 /* send RX_CHANGED to the user immediately */
576 bcm_rx_changed(op, lastdata);
580 /* with active throttling timer we are just done here */
581 if (hrtimer_active(&op->thrtimer))
584 /* first receiption with enabled throttling mode */
585 if (!op->kt_lastmsg.tv64)
586 goto rx_changed_settime;
588 /* got a second frame inside a potential throttle period? */
589 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
590 ktime_to_us(op->kt_ival2)) {
591 /* do not send the saved data - only start throttle timer */
592 hrtimer_start(&op->thrtimer,
593 ktime_add(op->kt_lastmsg, op->kt_ival2),
598 /* the gap was that big, that throttling was not needed here */
600 bcm_rx_changed(op, lastdata);
601 op->kt_lastmsg = ktime_get();
605 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
606 * received data stored in op->last_frames[]
608 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
609 const struct can_frame *rxdata)
612 * no one uses the MSBs of can_dlc for comparation,
613 * so we use it here to detect the first time of reception
616 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
617 /* received data for the first time => send update to user */
618 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
622 /* do a real check in can_frame data section */
624 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
625 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
626 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
630 if (op->flags & RX_CHECK_DLC) {
631 /* do a real check in can_frame dlc */
632 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
634 bcm_rx_update_and_send(op, &op->last_frames[index],
642 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
644 static void bcm_rx_starttimer(struct bcm_op *op)
646 if (op->flags & RX_NO_AUTOTIMER)
649 if (op->kt_ival1.tv64)
650 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
653 static void bcm_rx_timeout_tsklet(unsigned long data)
655 struct bcm_op *op = (struct bcm_op *)data;
656 struct bcm_msg_head msg_head;
658 /* create notification to user */
659 msg_head.opcode = RX_TIMEOUT;
660 msg_head.flags = op->flags;
661 msg_head.count = op->count;
662 msg_head.ival1 = op->ival1;
663 msg_head.ival2 = op->ival2;
664 msg_head.can_id = op->can_id;
665 msg_head.nframes = 0;
667 bcm_send_to_user(op, &msg_head, NULL, 0);
671 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
673 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
675 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
677 /* schedule before NET_RX_SOFTIRQ */
678 tasklet_hi_schedule(&op->tsklet);
680 /* no restart of the timer is done here! */
682 /* if user wants to be informed, when cyclic CAN-Messages come back */
683 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
684 /* clear received can_frames to indicate 'nothing received' */
685 memset(op->last_frames, 0, op->nframes * CFSIZ);
688 return HRTIMER_NORESTART;
692 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
694 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
697 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
699 bcm_rx_changed(op, &op->last_frames[index]);
706 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
708 * update == 0 : just check if throttled data is available (any irq context)
709 * update == 1 : check and send throttled data to userspace (soft_irq context)
711 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
715 if (op->nframes > 1) {
718 /* for MUX filter we start at index 1 */
719 for (i = 1; i < op->nframes; i++)
720 updated += bcm_rx_do_flush(op, update, i);
723 /* for RX_FILTER_ID and simple filter */
724 updated += bcm_rx_do_flush(op, update, 0);
730 static void bcm_rx_thr_tsklet(unsigned long data)
732 struct bcm_op *op = (struct bcm_op *)data;
734 /* push the changed data to the userspace */
735 bcm_rx_thr_flush(op, 1);
739 * bcm_rx_thr_handler - the time for blocked content updates is over now:
740 * Check for throttled data and send it to the userspace
742 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
744 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
746 tasklet_schedule(&op->thrtsklet);
748 if (bcm_rx_thr_flush(op, 0)) {
749 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
750 return HRTIMER_RESTART;
752 /* rearm throttle handling */
753 op->kt_lastmsg = ktime_set(0, 0);
754 return HRTIMER_NORESTART;
759 * bcm_rx_handler - handle a CAN frame receiption
761 static void bcm_rx_handler(struct sk_buff *skb, void *data)
763 struct bcm_op *op = (struct bcm_op *)data;
764 const struct can_frame *rxframe = (struct can_frame *)skb->data;
767 /* disable timeout */
768 hrtimer_cancel(&op->timer);
770 if (op->can_id != rxframe->can_id)
773 /* save rx timestamp */
774 op->rx_stamp = skb->tstamp;
775 /* save originator for recvfrom() */
776 op->rx_ifindex = skb->dev->ifindex;
777 /* update statistics */
780 if (op->flags & RX_RTR_FRAME) {
781 /* send reply for RTR-request (placed in op->frames[0]) */
786 if (op->flags & RX_FILTER_ID) {
787 /* the easiest case */
788 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
792 if (op->nframes == 1) {
793 /* simple compare with index 0 */
794 bcm_rx_cmp_to_index(op, 0, rxframe);
798 if (op->nframes > 1) {
802 * find the first multiplex mask that fits.
803 * Remark: The MUX-mask is stored in index 0
806 for (i = 1; i < op->nframes; i++) {
807 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
808 (GET_U64(&op->frames[0]) &
809 GET_U64(&op->frames[i]))) {
810 bcm_rx_cmp_to_index(op, i, rxframe);
817 bcm_rx_starttimer(op);
821 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
823 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
828 list_for_each_entry(op, ops, list) {
829 if ((op->can_id == can_id) && (op->ifindex == ifindex))
836 static void bcm_remove_op(struct bcm_op *op)
838 hrtimer_cancel(&op->timer);
839 hrtimer_cancel(&op->thrtimer);
842 tasklet_kill(&op->tsklet);
844 if (op->thrtsklet.func)
845 tasklet_kill(&op->thrtsklet);
847 if ((op->frames) && (op->frames != &op->sframe))
850 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
851 kfree(op->last_frames);
858 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
860 if (op->rx_reg_dev == dev) {
861 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
864 /* mark as removed subscription */
865 op->rx_reg_dev = NULL;
867 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
868 "mismatch %p %p\n", op->rx_reg_dev, dev);
872 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
874 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
876 struct bcm_op *op, *n;
878 list_for_each_entry_safe(op, n, ops, list) {
879 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
882 * Don't care if we're bound or not (due to netdev
883 * problems) can_rx_unregister() is always a save
888 * Only remove subscriptions that had not
889 * been removed due to NETDEV_UNREGISTER
892 if (op->rx_reg_dev) {
893 struct net_device *dev;
895 dev = dev_get_by_index(&init_net,
898 bcm_rx_unreg(dev, op);
903 can_rx_unregister(NULL, op->can_id,
913 return 0; /* not found */
917 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
919 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
921 struct bcm_op *op, *n;
923 list_for_each_entry_safe(op, n, ops, list) {
924 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
931 return 0; /* not found */
935 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
937 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
940 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
945 /* put current values into msg_head */
946 msg_head->flags = op->flags;
947 msg_head->count = op->count;
948 msg_head->ival1 = op->ival1;
949 msg_head->ival2 = op->ival2;
950 msg_head->nframes = op->nframes;
952 bcm_send_to_user(op, msg_head, op->frames, 0);
958 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
960 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
961 int ifindex, struct sock *sk)
963 struct bcm_sock *bo = bcm_sk(sk);
968 /* we need a real device to send frames */
972 /* check nframes boundaries - we need at least one can_frame */
973 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
976 /* check the given can_id */
977 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
980 /* update existing BCM operation */
983 * Do we need more space for the can_frames than currently
984 * allocated? -> This is a _really_ unusual use-case and
985 * therefore (complexity / locking) it is not supported.
987 if (msg_head->nframes > op->nframes)
990 /* update can_frames content */
991 for (i = 0; i < msg_head->nframes; i++) {
992 err = memcpy_fromiovec((u8 *)&op->frames[i],
993 msg->msg_iov, CFSIZ);
995 if (op->frames[i].can_dlc > 8)
1001 if (msg_head->flags & TX_CP_CAN_ID) {
1002 /* copy can_id into frame */
1003 op->frames[i].can_id = msg_head->can_id;
1008 /* insert new BCM operation for the given can_id */
1010 op = kzalloc(OPSIZ, GFP_KERNEL);
1014 op->can_id = msg_head->can_id;
1016 /* create array for can_frames and copy the data */
1017 if (msg_head->nframes > 1) {
1018 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1025 op->frames = &op->sframe;
1027 for (i = 0; i < msg_head->nframes; i++) {
1028 err = memcpy_fromiovec((u8 *)&op->frames[i],
1029 msg->msg_iov, CFSIZ);
1031 if (op->frames[i].can_dlc > 8)
1035 if (op->frames != &op->sframe)
1041 if (msg_head->flags & TX_CP_CAN_ID) {
1042 /* copy can_id into frame */
1043 op->frames[i].can_id = msg_head->can_id;
1047 /* tx_ops never compare with previous received messages */
1048 op->last_frames = NULL;
1050 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1052 op->ifindex = ifindex;
1054 /* initialize uninitialized (kzalloc) structure */
1055 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1056 op->timer.function = bcm_tx_timeout_handler;
1058 /* initialize tasklet for tx countevent notification */
1059 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
1060 (unsigned long) op);
1062 /* currently unused in tx_ops */
1063 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1065 /* add this bcm_op to the list of the tx_ops */
1066 list_add(&op->list, &bo->tx_ops);
1068 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
1070 if (op->nframes != msg_head->nframes) {
1071 op->nframes = msg_head->nframes;
1072 /* start multiple frame transmission with index 0 */
1078 op->flags = msg_head->flags;
1080 if (op->flags & TX_RESET_MULTI_IDX) {
1081 /* start multiple frame transmission with index 0 */
1085 if (op->flags & SETTIMER) {
1086 /* set timer values */
1087 op->count = msg_head->count;
1088 op->ival1 = msg_head->ival1;
1089 op->ival2 = msg_head->ival2;
1090 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1091 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1093 /* disable an active timer due to zero values? */
1094 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
1095 hrtimer_cancel(&op->timer);
1098 if ((op->flags & STARTTIMER) &&
1099 ((op->kt_ival1.tv64 && op->count) || op->kt_ival2.tv64)) {
1101 /* spec: send can_frame when starting timer */
1102 op->flags |= TX_ANNOUNCE;
1104 if (op->kt_ival1.tv64 && (op->count > 0)) {
1105 /* op->count-- is done in bcm_tx_timeout_handler */
1106 hrtimer_start(&op->timer, op->kt_ival1,
1109 hrtimer_start(&op->timer, op->kt_ival2,
1113 if (op->flags & TX_ANNOUNCE)
1116 return msg_head->nframes * CFSIZ + MHSIZ;
1120 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1122 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1123 int ifindex, struct sock *sk)
1125 struct bcm_sock *bo = bcm_sk(sk);
1130 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1131 /* be robust against wrong usage ... */
1132 msg_head->flags |= RX_FILTER_ID;
1133 /* ignore trailing garbage */
1134 msg_head->nframes = 0;
1137 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1138 if (msg_head->nframes > MAX_NFRAMES + 1)
1141 if ((msg_head->flags & RX_RTR_FRAME) &&
1142 ((msg_head->nframes != 1) ||
1143 (!(msg_head->can_id & CAN_RTR_FLAG))))
1146 /* check the given can_id */
1147 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1149 /* update existing BCM operation */
1152 * Do we need more space for the can_frames than currently
1153 * allocated? -> This is a _really_ unusual use-case and
1154 * therefore (complexity / locking) it is not supported.
1156 if (msg_head->nframes > op->nframes)
1159 if (msg_head->nframes) {
1160 /* update can_frames content */
1161 err = memcpy_fromiovec((u8 *)op->frames,
1163 msg_head->nframes * CFSIZ);
1167 /* clear last_frames to indicate 'nothing received' */
1168 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1171 op->nframes = msg_head->nframes;
1173 /* Only an update -> do not call can_rx_register() */
1177 /* insert new BCM operation for the given can_id */
1178 op = kzalloc(OPSIZ, GFP_KERNEL);
1182 op->can_id = msg_head->can_id;
1183 op->nframes = msg_head->nframes;
1185 if (msg_head->nframes > 1) {
1186 /* create array for can_frames and copy the data */
1187 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1194 /* create and init array for received can_frames */
1195 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1197 if (!op->last_frames) {
1204 op->frames = &op->sframe;
1205 op->last_frames = &op->last_sframe;
1208 if (msg_head->nframes) {
1209 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1210 msg_head->nframes * CFSIZ);
1212 if (op->frames != &op->sframe)
1214 if (op->last_frames != &op->last_sframe)
1215 kfree(op->last_frames);
1221 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1223 op->ifindex = ifindex;
1225 /* initialize uninitialized (kzalloc) structure */
1226 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1227 op->timer.function = bcm_rx_timeout_handler;
1229 /* initialize tasklet for rx timeout notification */
1230 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1231 (unsigned long) op);
1233 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1234 op->thrtimer.function = bcm_rx_thr_handler;
1236 /* initialize tasklet for rx throttle handling */
1237 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1238 (unsigned long) op);
1240 /* add this bcm_op to the list of the rx_ops */
1241 list_add(&op->list, &bo->rx_ops);
1243 /* call can_rx_register() */
1246 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1249 op->flags = msg_head->flags;
1251 if (op->flags & RX_RTR_FRAME) {
1253 /* no timers in RTR-mode */
1254 hrtimer_cancel(&op->thrtimer);
1255 hrtimer_cancel(&op->timer);
1258 * funny feature in RX(!)_SETUP only for RTR-mode:
1259 * copy can_id into frame BUT without RTR-flag to
1260 * prevent a full-load-loopback-test ... ;-]
1262 if ((op->flags & TX_CP_CAN_ID) ||
1263 (op->frames[0].can_id == op->can_id))
1264 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1267 if (op->flags & SETTIMER) {
1269 /* set timer value */
1270 op->ival1 = msg_head->ival1;
1271 op->ival2 = msg_head->ival2;
1272 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1273 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1275 /* disable an active timer due to zero value? */
1276 if (!op->kt_ival1.tv64)
1277 hrtimer_cancel(&op->timer);
1280 * In any case cancel the throttle timer, flush
1281 * potentially blocked msgs and reset throttle handling
1283 op->kt_lastmsg = ktime_set(0, 0);
1284 hrtimer_cancel(&op->thrtimer);
1285 bcm_rx_thr_flush(op, 1);
1288 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1289 hrtimer_start(&op->timer, op->kt_ival1,
1293 /* now we can register for can_ids, if we added a new bcm_op */
1294 if (do_rx_register) {
1296 struct net_device *dev;
1298 dev = dev_get_by_index(&init_net, ifindex);
1300 err = can_rx_register(dev, op->can_id,
1301 REGMASK(op->can_id),
1305 op->rx_reg_dev = dev;
1310 err = can_rx_register(NULL, op->can_id,
1311 REGMASK(op->can_id),
1312 bcm_rx_handler, op, "bcm");
1314 /* this bcm rx op is broken -> remove it */
1315 list_del(&op->list);
1321 return msg_head->nframes * CFSIZ + MHSIZ;
1325 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1327 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1329 struct sk_buff *skb;
1330 struct net_device *dev;
1333 /* we need a real device to send frames */
1337 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1342 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1348 dev = dev_get_by_index(&init_net, ifindex);
1356 err = can_send(skb, 1); /* send with loopback */
1362 return CFSIZ + MHSIZ;
1366 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1368 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1369 struct msghdr *msg, size_t size)
1371 struct sock *sk = sock->sk;
1372 struct bcm_sock *bo = bcm_sk(sk);
1373 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1374 struct bcm_msg_head msg_head;
1375 int ret; /* read bytes or error codes as return value */
1380 /* check for valid message length from userspace */
1381 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1384 /* check for alternative ifindex for this bcm_op */
1386 if (!ifindex && msg->msg_name) {
1387 /* no bound device as default => check msg_name */
1388 struct sockaddr_can *addr =
1389 (struct sockaddr_can *)msg->msg_name;
1391 if (msg->msg_namelen < sizeof(*addr))
1394 if (addr->can_family != AF_CAN)
1397 /* ifindex from sendto() */
1398 ifindex = addr->can_ifindex;
1401 struct net_device *dev;
1403 dev = dev_get_by_index(&init_net, ifindex);
1407 if (dev->type != ARPHRD_CAN) {
1416 /* read message head information */
1418 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1424 switch (msg_head.opcode) {
1427 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1431 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1435 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1442 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1449 /* reuse msg_head for the reply to TX_READ */
1450 msg_head.opcode = TX_STATUS;
1451 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1455 /* reuse msg_head for the reply to RX_READ */
1456 msg_head.opcode = RX_STATUS;
1457 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1461 /* we need exactly one can_frame behind the msg head */
1462 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1465 ret = bcm_tx_send(msg, ifindex, sk);
1479 * notification handler for netdevice status changes
1481 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1484 struct net_device *dev = (struct net_device *)data;
1485 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1486 struct sock *sk = &bo->sk;
1488 int notify_enodev = 0;
1490 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
1491 if (!net_eq(dev_net(dev), &init_net))
1493 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
1494 if (dev->nd_net != &init_net)
1498 if (dev->type != ARPHRD_CAN)
1503 case NETDEV_UNREGISTER:
1506 /* remove device specific receive entries */
1507 list_for_each_entry(op, &bo->rx_ops, list)
1508 if (op->rx_reg_dev == dev)
1509 bcm_rx_unreg(dev, op);
1511 /* remove device reference, if this is our bound device */
1512 if (bo->bound && bo->ifindex == dev->ifindex) {
1520 if (notify_enodev) {
1521 sk->sk_err = ENODEV;
1522 if (!sock_flag(sk, SOCK_DEAD))
1523 sk->sk_error_report(sk);
1528 if (bo->bound && bo->ifindex == dev->ifindex) {
1529 sk->sk_err = ENETDOWN;
1530 if (!sock_flag(sk, SOCK_DEAD))
1531 sk->sk_error_report(sk);
1539 * initial settings for all BCM sockets to be set at socket creation time
1541 static int bcm_init(struct sock *sk)
1543 struct bcm_sock *bo = bcm_sk(sk);
1547 bo->dropped_usr_msgs = 0;
1548 bo->bcm_proc_read = NULL;
1550 INIT_LIST_HEAD(&bo->tx_ops);
1551 INIT_LIST_HEAD(&bo->rx_ops);
1554 bo->notifier.notifier_call = bcm_notifier;
1556 register_netdevice_notifier(&bo->notifier);
1562 * standard socket functions
1564 static int bcm_release(struct socket *sock)
1566 struct sock *sk = sock->sk;
1567 struct bcm_sock *bo;
1568 struct bcm_op *op, *next;
1575 /* remove bcm_ops, timer, rx_unregister(), etc. */
1577 unregister_netdevice_notifier(&bo->notifier);
1581 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1584 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1586 * Don't care if we're bound or not (due to netdev problems)
1587 * can_rx_unregister() is always a save thing to do here.
1591 * Only remove subscriptions that had not
1592 * been removed due to NETDEV_UNREGISTER
1595 if (op->rx_reg_dev) {
1596 struct net_device *dev;
1598 dev = dev_get_by_index(&init_net, op->ifindex);
1600 bcm_rx_unreg(dev, op);
1605 can_rx_unregister(NULL, op->can_id,
1606 REGMASK(op->can_id),
1607 bcm_rx_handler, op);
1612 /* remove procfs entry */
1613 if (proc_dir && bo->bcm_proc_read)
1614 remove_proc_entry(bo->procname, proc_dir);
1616 /* remove device reference */
1631 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1634 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1635 struct sock *sk = sock->sk;
1636 struct bcm_sock *bo = bcm_sk(sk);
1638 if (len < sizeof(*addr))
1644 /* bind a device to this socket */
1645 if (addr->can_ifindex) {
1646 struct net_device *dev;
1648 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1652 if (dev->type != ARPHRD_CAN) {
1657 bo->ifindex = dev->ifindex;
1661 /* no interface reference for ifindex = 0 ('any' CAN device) */
1668 /* unique socket address as filename */
1669 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1670 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
1671 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1673 &bcm_proc_fops, sk);
1675 bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644,
1684 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1685 struct msghdr *msg, size_t size, int flags)
1687 struct sock *sk = sock->sk;
1688 struct sk_buff *skb;
1693 noblock = flags & MSG_DONTWAIT;
1694 flags &= ~MSG_DONTWAIT;
1695 skb = skb_recv_datagram(sk, flags, noblock, &error);
1699 if (skb->len < size)
1702 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1704 skb_free_datagram(sk, skb);
1708 sock_recv_timestamp(msg, sk, skb);
1710 if (msg->msg_name) {
1711 msg->msg_namelen = sizeof(struct sockaddr_can);
1712 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1715 skb_free_datagram(sk, skb);
1720 static const struct proto_ops bcm_ops = {
1722 .release = bcm_release,
1723 .bind = sock_no_bind,
1724 .connect = bcm_connect,
1725 .socketpair = sock_no_socketpair,
1726 .accept = sock_no_accept,
1727 .getname = sock_no_getname,
1728 .poll = datagram_poll,
1729 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1730 .listen = sock_no_listen,
1731 .shutdown = sock_no_shutdown,
1732 .setsockopt = sock_no_setsockopt,
1733 .getsockopt = sock_no_getsockopt,
1734 .sendmsg = bcm_sendmsg,
1735 .recvmsg = bcm_recvmsg,
1736 .mmap = sock_no_mmap,
1737 .sendpage = sock_no_sendpage,
1740 static struct proto bcm_proto __read_mostly = {
1742 .owner = THIS_MODULE,
1743 .obj_size = sizeof(struct bcm_sock),
1747 static const struct can_proto bcm_can_proto = {
1749 .protocol = CAN_BCM,
1750 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33)
1757 static int __init bcm_module_init(void)
1763 err = can_proto_register(&bcm_can_proto);
1765 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1769 /* create /proc/net/can-bcm directory */
1770 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
1771 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1773 proc_dir = proc_mkdir("can-bcm", proc_net);
1776 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,30)
1778 proc_dir->owner = THIS_MODULE;
1784 static void __exit bcm_module_exit(void)
1786 can_proto_unregister(&bcm_can_proto);
1789 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
1790 proc_net_remove(&init_net, "can-bcm");
1792 proc_net_remove("can-bcm");
1796 module_init(bcm_module_init);
1797 module_exit(bcm_module_exit);