2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
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8 * modification, are permitted provided that the following conditions
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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.
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44 #include <linux/module.h>
45 #include <linux/init.h>
46 #include <linux/hrtimer.h>
47 #include <linux/list.h>
48 #include <linux/proc_fs.h>
49 #include <linux/seq_file.h>
50 #include <linux/uio.h>
51 #include <linux/net.h>
52 #include <linux/netdevice.h>
53 #include <linux/socket.h>
54 #include <linux/if_arp.h>
55 #include <linux/skbuff.h>
56 #include <linux/can.h>
57 #include <linux/can/core.h>
58 #include <linux/can/bcm.h>
59 #include <linux/slab.h>
61 #include <net/net_namespace.h>
64 * To send multiple CAN frame content within TX_SETUP or to filter
65 * CAN messages with multiplex index within RX_SETUP, the number of
66 * different filters is limited to 256 due to the one byte index value.
68 #define MAX_NFRAMES 256
70 /* use of last_frames[index].can_dlc */
71 #define RX_RECV 0x40 /* received data for this element */
72 #define RX_THR 0x80 /* element not been sent due to throttle feature */
73 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
75 /* get best masking value for can_rx_register() for a given single can_id */
76 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
77 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
78 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
80 #define CAN_BCM_VERSION CAN_VERSION
81 static __initdata const char banner[] = KERN_INFO
82 "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
84 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
85 MODULE_LICENSE("Dual BSD/GPL");
86 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
87 MODULE_ALIAS("can-proto-2");
89 /* easy access to can_frame payload */
90 static inline u64 GET_U64(const struct can_frame *cp)
92 return *(u64 *)cp->data;
96 struct list_head list;
100 unsigned long frames_abs, frames_filtered;
101 struct timeval ival1, ival2;
102 struct hrtimer timer, thrtimer;
103 struct tasklet_struct tsklet, thrtsklet;
104 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
109 struct can_frame *frames;
110 struct can_frame *last_frames;
111 struct can_frame sframe;
112 struct can_frame last_sframe;
114 struct net_device *rx_reg_dev;
117 static struct proc_dir_entry *proc_dir;
123 struct notifier_block notifier;
124 struct list_head rx_ops;
125 struct list_head tx_ops;
126 unsigned long dropped_usr_msgs;
127 struct proc_dir_entry *bcm_proc_read;
128 char procname [32]; /* inode number in decimal with \0 */
131 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
133 return (struct bcm_sock *)sk;
136 #define CFSIZ sizeof(struct can_frame)
137 #define OPSIZ sizeof(struct bcm_op)
138 #define MHSIZ sizeof(struct bcm_msg_head)
143 static char *bcm_proc_getifname(char *result, int ifindex)
145 struct net_device *dev;
151 dev = dev_get_by_index_rcu(&init_net, ifindex);
153 strcpy(result, dev->name);
155 strcpy(result, "???");
161 static int bcm_proc_show(struct seq_file *m, void *v)
163 char ifname[IFNAMSIZ];
164 struct sock *sk = (struct sock *)m->private;
165 struct bcm_sock *bo = bcm_sk(sk);
168 seq_printf(m, ">>> socket %pK", sk->sk_socket);
169 seq_printf(m, " / sk %pK", sk);
170 seq_printf(m, " / bo %pK", bo);
171 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
172 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
173 seq_printf(m, " <<<\n");
175 list_for_each_entry(op, &bo->rx_ops, list) {
177 unsigned long reduction;
179 /* print only active entries & prevent division by zero */
183 seq_printf(m, "rx_op: %03X %-5s ",
184 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
185 seq_printf(m, "[%u]%c ", op->nframes,
186 (op->flags & RX_CHECK_DLC)?'d':' ');
187 if (op->kt_ival1.tv64)
188 seq_printf(m, "timeo=%lld ",
190 ktime_to_us(op->kt_ival1));
192 if (op->kt_ival2.tv64)
193 seq_printf(m, "thr=%lld ",
195 ktime_to_us(op->kt_ival2));
197 seq_printf(m, "# recv %ld (%ld) => reduction: ",
198 op->frames_filtered, op->frames_abs);
200 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
202 seq_printf(m, "%s%ld%%\n",
203 (reduction == 100)?"near ":"", reduction);
206 list_for_each_entry(op, &bo->tx_ops, list) {
208 seq_printf(m, "tx_op: %03X %s [%u] ",
210 bcm_proc_getifname(ifname, op->ifindex),
213 if (op->kt_ival1.tv64)
214 seq_printf(m, "t1=%lld ",
215 (long long) ktime_to_us(op->kt_ival1));
217 if (op->kt_ival2.tv64)
218 seq_printf(m, "t2=%lld ",
219 (long long) ktime_to_us(op->kt_ival2));
221 seq_printf(m, "# sent %ld\n", op->frames_abs);
227 static int bcm_proc_open(struct inode *inode, struct file *file)
229 return single_open(file, bcm_proc_show, PDE(inode)->data);
232 static const struct file_operations bcm_proc_fops = {
233 .owner = THIS_MODULE,
234 .open = bcm_proc_open,
237 .release = single_release,
241 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
242 * of the given bcm tx op
244 static void bcm_can_tx(struct bcm_op *op)
247 struct net_device *dev;
248 struct can_frame *cf = &op->frames[op->currframe];
250 /* no target device? => exit */
254 dev = dev_get_by_index(&init_net, op->ifindex);
256 /* RFC: should this bcm_op remove itself here? */
260 skb = alloc_skb(CFSIZ, gfp_any());
264 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
266 /* send with loopback */
271 /* update statistics */
275 /* reached last frame? */
276 if (op->currframe >= op->nframes)
283 * bcm_send_to_user - send a BCM message to the userspace
284 * (consisting of bcm_msg_head + x CAN frames)
286 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
287 struct can_frame *frames, int has_timestamp)
290 struct can_frame *firstframe;
291 struct sockaddr_can *addr;
292 struct sock *sk = op->sk;
293 unsigned int datalen = head->nframes * CFSIZ;
296 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
300 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
303 /* can_frames starting here */
304 firstframe = (struct can_frame *)skb_tail_pointer(skb);
306 memcpy(skb_put(skb, datalen), frames, datalen);
309 * the BCM uses the can_dlc-element of the can_frame
310 * structure for internal purposes. This is only
311 * relevant for updates that are generated by the
312 * BCM, where nframes is 1
314 if (head->nframes == 1)
315 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
319 /* restore rx timestamp */
320 skb->tstamp = op->rx_stamp;
324 * Put the datagram to the queue so that bcm_recvmsg() can
325 * get it from there. We need to pass the interface index to
326 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
327 * containing the interface index.
330 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
331 addr = (struct sockaddr_can *)skb->cb;
332 memset(addr, 0, sizeof(*addr));
333 addr->can_family = AF_CAN;
334 addr->can_ifindex = op->rx_ifindex;
336 err = sock_queue_rcv_skb(sk, skb);
338 struct bcm_sock *bo = bcm_sk(sk);
341 /* don't care about overflows in this statistic */
342 bo->dropped_usr_msgs++;
346 static void bcm_tx_start_timer(struct bcm_op *op)
348 if (op->kt_ival1.tv64 && op->count)
349 hrtimer_start(&op->timer,
350 ktime_add(ktime_get(), op->kt_ival1),
352 else if (op->kt_ival2.tv64)
353 hrtimer_start(&op->timer,
354 ktime_add(ktime_get(), op->kt_ival2),
358 static void bcm_tx_timeout_tsklet(unsigned long data)
360 struct bcm_op *op = (struct bcm_op *)data;
361 struct bcm_msg_head msg_head;
363 if (op->kt_ival1.tv64 && (op->count > 0)) {
366 if (!op->count && (op->flags & TX_COUNTEVT)) {
368 /* create notification to user */
369 msg_head.opcode = TX_EXPIRED;
370 msg_head.flags = op->flags;
371 msg_head.count = op->count;
372 msg_head.ival1 = op->ival1;
373 msg_head.ival2 = op->ival2;
374 msg_head.can_id = op->can_id;
375 msg_head.nframes = 0;
377 bcm_send_to_user(op, &msg_head, NULL, 0);
381 } else if (op->kt_ival2.tv64)
384 bcm_tx_start_timer(op);
388 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
390 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
392 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
394 tasklet_schedule(&op->tsklet);
396 return HRTIMER_NORESTART;
400 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
402 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
404 struct bcm_msg_head head;
406 /* update statistics */
407 op->frames_filtered++;
409 /* prevent statistics overflow */
410 if (op->frames_filtered > ULONG_MAX/100)
411 op->frames_filtered = op->frames_abs = 0;
413 /* this element is not throttled anymore */
414 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
416 head.opcode = RX_CHANGED;
417 head.flags = op->flags;
418 head.count = op->count;
419 head.ival1 = op->ival1;
420 head.ival2 = op->ival2;
421 head.can_id = op->can_id;
424 bcm_send_to_user(op, &head, data, 1);
428 * bcm_rx_update_and_send - process a detected relevant receive content change
429 * 1. update the last received data
430 * 2. send a notification to the user (if possible)
432 static void bcm_rx_update_and_send(struct bcm_op *op,
433 struct can_frame *lastdata,
434 const struct can_frame *rxdata)
436 memcpy(lastdata, rxdata, CFSIZ);
438 /* mark as used and throttled by default */
439 lastdata->can_dlc |= (RX_RECV|RX_THR);
441 /* throtteling mode inactive ? */
442 if (!op->kt_ival2.tv64) {
443 /* send RX_CHANGED to the user immediately */
444 bcm_rx_changed(op, lastdata);
448 /* with active throttling timer we are just done here */
449 if (hrtimer_active(&op->thrtimer))
452 /* first receiption with enabled throttling mode */
453 if (!op->kt_lastmsg.tv64)
454 goto rx_changed_settime;
456 /* got a second frame inside a potential throttle period? */
457 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
458 ktime_to_us(op->kt_ival2)) {
459 /* do not send the saved data - only start throttle timer */
460 hrtimer_start(&op->thrtimer,
461 ktime_add(op->kt_lastmsg, op->kt_ival2),
466 /* the gap was that big, that throttling was not needed here */
468 bcm_rx_changed(op, lastdata);
469 op->kt_lastmsg = ktime_get();
473 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
474 * received data stored in op->last_frames[]
476 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
477 const struct can_frame *rxdata)
480 * no one uses the MSBs of can_dlc for comparation,
481 * so we use it here to detect the first time of reception
484 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
485 /* received data for the first time => send update to user */
486 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
490 /* do a real check in can_frame data section */
492 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
493 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
494 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
498 if (op->flags & RX_CHECK_DLC) {
499 /* do a real check in can_frame dlc */
500 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
502 bcm_rx_update_and_send(op, &op->last_frames[index],
510 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
512 static void bcm_rx_starttimer(struct bcm_op *op)
514 if (op->flags & RX_NO_AUTOTIMER)
517 if (op->kt_ival1.tv64)
518 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
521 static void bcm_rx_timeout_tsklet(unsigned long data)
523 struct bcm_op *op = (struct bcm_op *)data;
524 struct bcm_msg_head msg_head;
526 /* create notification to user */
527 msg_head.opcode = RX_TIMEOUT;
528 msg_head.flags = op->flags;
529 msg_head.count = op->count;
530 msg_head.ival1 = op->ival1;
531 msg_head.ival2 = op->ival2;
532 msg_head.can_id = op->can_id;
533 msg_head.nframes = 0;
535 bcm_send_to_user(op, &msg_head, NULL, 0);
539 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
541 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
543 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
545 /* schedule before NET_RX_SOFTIRQ */
546 tasklet_hi_schedule(&op->tsklet);
548 /* no restart of the timer is done here! */
550 /* if user wants to be informed, when cyclic CAN-Messages come back */
551 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
552 /* clear received can_frames to indicate 'nothing received' */
553 memset(op->last_frames, 0, op->nframes * CFSIZ);
556 return HRTIMER_NORESTART;
560 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
562 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
565 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
567 bcm_rx_changed(op, &op->last_frames[index]);
574 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
576 * update == 0 : just check if throttled data is available (any irq context)
577 * update == 1 : check and send throttled data to userspace (soft_irq context)
579 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
583 if (op->nframes > 1) {
586 /* for MUX filter we start at index 1 */
587 for (i = 1; i < op->nframes; i++)
588 updated += bcm_rx_do_flush(op, update, i);
591 /* for RX_FILTER_ID and simple filter */
592 updated += bcm_rx_do_flush(op, update, 0);
598 static void bcm_rx_thr_tsklet(unsigned long data)
600 struct bcm_op *op = (struct bcm_op *)data;
602 /* push the changed data to the userspace */
603 bcm_rx_thr_flush(op, 1);
607 * bcm_rx_thr_handler - the time for blocked content updates is over now:
608 * Check for throttled data and send it to the userspace
610 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
612 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
614 tasklet_schedule(&op->thrtsklet);
616 if (bcm_rx_thr_flush(op, 0)) {
617 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
618 return HRTIMER_RESTART;
620 /* rearm throttle handling */
621 op->kt_lastmsg = ktime_set(0, 0);
622 return HRTIMER_NORESTART;
627 * bcm_rx_handler - handle a CAN frame receiption
629 static void bcm_rx_handler(struct sk_buff *skb, void *data)
631 struct bcm_op *op = (struct bcm_op *)data;
632 const struct can_frame *rxframe = (struct can_frame *)skb->data;
635 /* disable timeout */
636 hrtimer_cancel(&op->timer);
638 if (op->can_id != rxframe->can_id)
641 /* save rx timestamp */
642 op->rx_stamp = skb->tstamp;
643 /* save originator for recvfrom() */
644 op->rx_ifindex = skb->dev->ifindex;
645 /* update statistics */
648 if (op->flags & RX_RTR_FRAME) {
649 /* send reply for RTR-request (placed in op->frames[0]) */
654 if (op->flags & RX_FILTER_ID) {
655 /* the easiest case */
656 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
660 if (op->nframes == 1) {
661 /* simple compare with index 0 */
662 bcm_rx_cmp_to_index(op, 0, rxframe);
666 if (op->nframes > 1) {
670 * find the first multiplex mask that fits.
671 * Remark: The MUX-mask is stored in index 0
674 for (i = 1; i < op->nframes; i++) {
675 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
676 (GET_U64(&op->frames[0]) &
677 GET_U64(&op->frames[i]))) {
678 bcm_rx_cmp_to_index(op, i, rxframe);
685 bcm_rx_starttimer(op);
689 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
691 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
696 list_for_each_entry(op, ops, list) {
697 if ((op->can_id == can_id) && (op->ifindex == ifindex))
704 static void bcm_remove_op(struct bcm_op *op)
706 hrtimer_cancel(&op->timer);
707 hrtimer_cancel(&op->thrtimer);
710 tasklet_kill(&op->tsklet);
712 if (op->thrtsklet.func)
713 tasklet_kill(&op->thrtsklet);
715 if ((op->frames) && (op->frames != &op->sframe))
718 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
719 kfree(op->last_frames);
724 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
726 if (op->rx_reg_dev == dev) {
727 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
730 /* mark as removed subscription */
731 op->rx_reg_dev = NULL;
733 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
734 "mismatch %p %p\n", op->rx_reg_dev, dev);
738 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
740 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
742 struct bcm_op *op, *n;
744 list_for_each_entry_safe(op, n, ops, list) {
745 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
748 * Don't care if we're bound or not (due to netdev
749 * problems) can_rx_unregister() is always a save
754 * Only remove subscriptions that had not
755 * been removed due to NETDEV_UNREGISTER
758 if (op->rx_reg_dev) {
759 struct net_device *dev;
761 dev = dev_get_by_index(&init_net,
764 bcm_rx_unreg(dev, op);
769 can_rx_unregister(NULL, op->can_id,
779 return 0; /* not found */
783 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
785 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
787 struct bcm_op *op, *n;
789 list_for_each_entry_safe(op, n, ops, list) {
790 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
797 return 0; /* not found */
801 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
803 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
806 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
811 /* put current values into msg_head */
812 msg_head->flags = op->flags;
813 msg_head->count = op->count;
814 msg_head->ival1 = op->ival1;
815 msg_head->ival2 = op->ival2;
816 msg_head->nframes = op->nframes;
818 bcm_send_to_user(op, msg_head, op->frames, 0);
824 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
826 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
827 int ifindex, struct sock *sk)
829 struct bcm_sock *bo = bcm_sk(sk);
834 /* we need a real device to send frames */
838 /* check nframes boundaries - we need at least one can_frame */
839 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
842 /* check the given can_id */
843 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
846 /* update existing BCM operation */
849 * Do we need more space for the can_frames than currently
850 * allocated? -> This is a _really_ unusual use-case and
851 * therefore (complexity / locking) it is not supported.
853 if (msg_head->nframes > op->nframes)
856 /* update can_frames content */
857 for (i = 0; i < msg_head->nframes; i++) {
858 err = memcpy_fromiovec((u8 *)&op->frames[i],
859 msg->msg_iov, CFSIZ);
861 if (op->frames[i].can_dlc > 8)
867 if (msg_head->flags & TX_CP_CAN_ID) {
868 /* copy can_id into frame */
869 op->frames[i].can_id = msg_head->can_id;
874 /* insert new BCM operation for the given can_id */
876 op = kzalloc(OPSIZ, GFP_KERNEL);
880 op->can_id = msg_head->can_id;
882 /* create array for can_frames and copy the data */
883 if (msg_head->nframes > 1) {
884 op->frames = kmalloc(msg_head->nframes * CFSIZ,
891 op->frames = &op->sframe;
893 for (i = 0; i < msg_head->nframes; i++) {
894 err = memcpy_fromiovec((u8 *)&op->frames[i],
895 msg->msg_iov, CFSIZ);
897 if (op->frames[i].can_dlc > 8)
901 if (op->frames != &op->sframe)
907 if (msg_head->flags & TX_CP_CAN_ID) {
908 /* copy can_id into frame */
909 op->frames[i].can_id = msg_head->can_id;
913 /* tx_ops never compare with previous received messages */
914 op->last_frames = NULL;
916 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
918 op->ifindex = ifindex;
920 /* initialize uninitialized (kzalloc) structure */
921 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
922 op->timer.function = bcm_tx_timeout_handler;
924 /* initialize tasklet for tx countevent notification */
925 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
928 /* currently unused in tx_ops */
929 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
931 /* add this bcm_op to the list of the tx_ops */
932 list_add(&op->list, &bo->tx_ops);
934 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
936 if (op->nframes != msg_head->nframes) {
937 op->nframes = msg_head->nframes;
938 /* start multiple frame transmission with index 0 */
944 op->flags = msg_head->flags;
946 if (op->flags & TX_RESET_MULTI_IDX) {
947 /* start multiple frame transmission with index 0 */
951 if (op->flags & SETTIMER) {
952 /* set timer values */
953 op->count = msg_head->count;
954 op->ival1 = msg_head->ival1;
955 op->ival2 = msg_head->ival2;
956 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
957 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
959 /* disable an active timer due to zero values? */
960 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
961 hrtimer_cancel(&op->timer);
964 if (op->flags & STARTTIMER) {
965 hrtimer_cancel(&op->timer);
966 /* spec: send can_frame when starting timer */
967 op->flags |= TX_ANNOUNCE;
970 if (op->flags & TX_ANNOUNCE) {
976 if (op->flags & STARTTIMER)
977 bcm_tx_start_timer(op);
979 return msg_head->nframes * CFSIZ + MHSIZ;
983 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
985 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
986 int ifindex, struct sock *sk)
988 struct bcm_sock *bo = bcm_sk(sk);
993 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
994 /* be robust against wrong usage ... */
995 msg_head->flags |= RX_FILTER_ID;
996 /* ignore trailing garbage */
997 msg_head->nframes = 0;
1000 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1001 if (msg_head->nframes > MAX_NFRAMES + 1)
1004 if ((msg_head->flags & RX_RTR_FRAME) &&
1005 ((msg_head->nframes != 1) ||
1006 (!(msg_head->can_id & CAN_RTR_FLAG))))
1009 /* check the given can_id */
1010 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1012 /* update existing BCM operation */
1015 * Do we need more space for the can_frames than currently
1016 * allocated? -> This is a _really_ unusual use-case and
1017 * therefore (complexity / locking) it is not supported.
1019 if (msg_head->nframes > op->nframes)
1022 if (msg_head->nframes) {
1023 /* update can_frames content */
1024 err = memcpy_fromiovec((u8 *)op->frames,
1026 msg_head->nframes * CFSIZ);
1030 /* clear last_frames to indicate 'nothing received' */
1031 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1034 op->nframes = msg_head->nframes;
1036 /* Only an update -> do not call can_rx_register() */
1040 /* insert new BCM operation for the given can_id */
1041 op = kzalloc(OPSIZ, GFP_KERNEL);
1045 op->can_id = msg_head->can_id;
1046 op->nframes = msg_head->nframes;
1048 if (msg_head->nframes > 1) {
1049 /* create array for can_frames and copy the data */
1050 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1057 /* create and init array for received can_frames */
1058 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1060 if (!op->last_frames) {
1067 op->frames = &op->sframe;
1068 op->last_frames = &op->last_sframe;
1071 if (msg_head->nframes) {
1072 err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1073 msg_head->nframes * CFSIZ);
1075 if (op->frames != &op->sframe)
1077 if (op->last_frames != &op->last_sframe)
1078 kfree(op->last_frames);
1084 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1086 op->ifindex = ifindex;
1088 /* ifindex for timeout events w/o previous frame reception */
1089 op->rx_ifindex = ifindex;
1091 /* initialize uninitialized (kzalloc) structure */
1092 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1093 op->timer.function = bcm_rx_timeout_handler;
1095 /* initialize tasklet for rx timeout notification */
1096 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1097 (unsigned long) op);
1099 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1100 op->thrtimer.function = bcm_rx_thr_handler;
1102 /* initialize tasklet for rx throttle handling */
1103 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1104 (unsigned long) op);
1106 /* add this bcm_op to the list of the rx_ops */
1107 list_add(&op->list, &bo->rx_ops);
1109 /* call can_rx_register() */
1112 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1115 op->flags = msg_head->flags;
1117 if (op->flags & RX_RTR_FRAME) {
1119 /* no timers in RTR-mode */
1120 hrtimer_cancel(&op->thrtimer);
1121 hrtimer_cancel(&op->timer);
1124 * funny feature in RX(!)_SETUP only for RTR-mode:
1125 * copy can_id into frame BUT without RTR-flag to
1126 * prevent a full-load-loopback-test ... ;-]
1128 if ((op->flags & TX_CP_CAN_ID) ||
1129 (op->frames[0].can_id == op->can_id))
1130 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1133 if (op->flags & SETTIMER) {
1135 /* set timer value */
1136 op->ival1 = msg_head->ival1;
1137 op->ival2 = msg_head->ival2;
1138 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1139 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1141 /* disable an active timer due to zero value? */
1142 if (!op->kt_ival1.tv64)
1143 hrtimer_cancel(&op->timer);
1146 * In any case cancel the throttle timer, flush
1147 * potentially blocked msgs and reset throttle handling
1149 op->kt_lastmsg = ktime_set(0, 0);
1150 hrtimer_cancel(&op->thrtimer);
1151 bcm_rx_thr_flush(op, 1);
1154 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1155 hrtimer_start(&op->timer, op->kt_ival1,
1159 /* now we can register for can_ids, if we added a new bcm_op */
1160 if (do_rx_register) {
1162 struct net_device *dev;
1164 dev = dev_get_by_index(&init_net, ifindex);
1166 err = can_rx_register(dev, op->can_id,
1167 REGMASK(op->can_id),
1171 op->rx_reg_dev = dev;
1176 err = can_rx_register(NULL, op->can_id,
1177 REGMASK(op->can_id),
1178 bcm_rx_handler, op, "bcm");
1180 /* this bcm rx op is broken -> remove it */
1181 list_del(&op->list);
1187 return msg_head->nframes * CFSIZ + MHSIZ;
1191 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1193 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1195 struct sk_buff *skb;
1196 struct net_device *dev;
1199 /* we need a real device to send frames */
1203 skb = alloc_skb(CFSIZ, GFP_KERNEL);
1208 err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1214 dev = dev_get_by_index(&init_net, ifindex);
1222 err = can_send(skb, 1); /* send with loopback */
1228 return CFSIZ + MHSIZ;
1232 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1234 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1235 struct msghdr *msg, size_t size)
1237 struct sock *sk = sock->sk;
1238 struct bcm_sock *bo = bcm_sk(sk);
1239 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1240 struct bcm_msg_head msg_head;
1241 int ret; /* read bytes or error codes as return value */
1246 /* check for valid message length from userspace */
1247 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1250 /* check for alternative ifindex for this bcm_op */
1252 if (!ifindex && msg->msg_name) {
1253 /* no bound device as default => check msg_name */
1254 struct sockaddr_can *addr =
1255 (struct sockaddr_can *)msg->msg_name;
1257 if (msg->msg_namelen < sizeof(*addr))
1260 if (addr->can_family != AF_CAN)
1263 /* ifindex from sendto() */
1264 ifindex = addr->can_ifindex;
1267 struct net_device *dev;
1269 dev = dev_get_by_index(&init_net, ifindex);
1273 if (dev->type != ARPHRD_CAN) {
1282 /* read message head information */
1284 ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1290 switch (msg_head.opcode) {
1293 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1297 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1301 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1308 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1315 /* reuse msg_head for the reply to TX_READ */
1316 msg_head.opcode = TX_STATUS;
1317 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1321 /* reuse msg_head for the reply to RX_READ */
1322 msg_head.opcode = RX_STATUS;
1323 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1327 /* we need exactly one can_frame behind the msg head */
1328 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1331 ret = bcm_tx_send(msg, ifindex, sk);
1345 * notification handler for netdevice status changes
1347 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1350 struct net_device *dev = (struct net_device *)data;
1351 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1352 struct sock *sk = &bo->sk;
1354 int notify_enodev = 0;
1356 if (!net_eq(dev_net(dev), &init_net))
1359 if (dev->type != ARPHRD_CAN)
1364 case NETDEV_UNREGISTER:
1367 /* remove device specific receive entries */
1368 list_for_each_entry(op, &bo->rx_ops, list)
1369 if (op->rx_reg_dev == dev)
1370 bcm_rx_unreg(dev, op);
1372 /* remove device reference, if this is our bound device */
1373 if (bo->bound && bo->ifindex == dev->ifindex) {
1381 if (notify_enodev) {
1382 sk->sk_err = ENODEV;
1383 if (!sock_flag(sk, SOCK_DEAD))
1384 sk->sk_error_report(sk);
1389 if (bo->bound && bo->ifindex == dev->ifindex) {
1390 sk->sk_err = ENETDOWN;
1391 if (!sock_flag(sk, SOCK_DEAD))
1392 sk->sk_error_report(sk);
1400 * initial settings for all BCM sockets to be set at socket creation time
1402 static int bcm_init(struct sock *sk)
1404 struct bcm_sock *bo = bcm_sk(sk);
1408 bo->dropped_usr_msgs = 0;
1409 bo->bcm_proc_read = NULL;
1411 INIT_LIST_HEAD(&bo->tx_ops);
1412 INIT_LIST_HEAD(&bo->rx_ops);
1415 bo->notifier.notifier_call = bcm_notifier;
1417 register_netdevice_notifier(&bo->notifier);
1423 * standard socket functions
1425 static int bcm_release(struct socket *sock)
1427 struct sock *sk = sock->sk;
1428 struct bcm_sock *bo;
1429 struct bcm_op *op, *next;
1436 /* remove bcm_ops, timer, rx_unregister(), etc. */
1438 unregister_netdevice_notifier(&bo->notifier);
1442 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1445 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1447 * Don't care if we're bound or not (due to netdev problems)
1448 * can_rx_unregister() is always a save thing to do here.
1452 * Only remove subscriptions that had not
1453 * been removed due to NETDEV_UNREGISTER
1456 if (op->rx_reg_dev) {
1457 struct net_device *dev;
1459 dev = dev_get_by_index(&init_net, op->ifindex);
1461 bcm_rx_unreg(dev, op);
1466 can_rx_unregister(NULL, op->can_id,
1467 REGMASK(op->can_id),
1468 bcm_rx_handler, op);
1473 /* remove procfs entry */
1474 if (proc_dir && bo->bcm_proc_read)
1475 remove_proc_entry(bo->procname, proc_dir);
1477 /* remove device reference */
1492 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1495 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1496 struct sock *sk = sock->sk;
1497 struct bcm_sock *bo = bcm_sk(sk);
1499 if (len < sizeof(*addr))
1505 /* bind a device to this socket */
1506 if (addr->can_ifindex) {
1507 struct net_device *dev;
1509 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1513 if (dev->type != ARPHRD_CAN) {
1518 bo->ifindex = dev->ifindex;
1522 /* no interface reference for ifindex = 0 ('any' CAN device) */
1529 /* unique socket address as filename */
1530 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1531 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1533 &bcm_proc_fops, sk);
1539 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1540 struct msghdr *msg, size_t size, int flags)
1542 struct sock *sk = sock->sk;
1543 struct sk_buff *skb;
1548 noblock = flags & MSG_DONTWAIT;
1549 flags &= ~MSG_DONTWAIT;
1550 skb = skb_recv_datagram(sk, flags, noblock, &error);
1554 if (skb->len < size)
1557 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1559 skb_free_datagram(sk, skb);
1563 sock_recv_ts_and_drops(msg, sk, skb);
1565 if (msg->msg_name) {
1566 msg->msg_namelen = sizeof(struct sockaddr_can);
1567 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1570 skb_free_datagram(sk, skb);
1575 static const struct proto_ops bcm_ops = {
1577 .release = bcm_release,
1578 .bind = sock_no_bind,
1579 .connect = bcm_connect,
1580 .socketpair = sock_no_socketpair,
1581 .accept = sock_no_accept,
1582 .getname = sock_no_getname,
1583 .poll = datagram_poll,
1584 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1585 .listen = sock_no_listen,
1586 .shutdown = sock_no_shutdown,
1587 .setsockopt = sock_no_setsockopt,
1588 .getsockopt = sock_no_getsockopt,
1589 .sendmsg = bcm_sendmsg,
1590 .recvmsg = bcm_recvmsg,
1591 .mmap = sock_no_mmap,
1592 .sendpage = sock_no_sendpage,
1595 static struct proto bcm_proto __read_mostly = {
1597 .owner = THIS_MODULE,
1598 .obj_size = sizeof(struct bcm_sock),
1602 static const struct can_proto bcm_can_proto = {
1604 .protocol = CAN_BCM,
1609 static int __init bcm_module_init(void)
1615 err = can_proto_register(&bcm_can_proto);
1617 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1621 /* create /proc/net/can-bcm directory */
1622 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1626 static void __exit bcm_module_exit(void)
1628 can_proto_unregister(&bcm_can_proto);
1631 proc_net_remove(&init_net, "can-bcm");
1634 module_init(bcm_module_init);
1635 module_exit(bcm_module_exit);