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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37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/interrupt.h>
45 #include <linux/hrtimer.h>
46 #include <linux/list.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.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/skb.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 /* limit timers to 400 days for sending/timeouts */
71 #define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
73 /* use of last_frames[index].can_dlc */
74 #define RX_RECV 0x40 /* received data for this element */
75 #define RX_THR 0x80 /* element not been sent due to throttle feature */
76 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
78 /* get best masking value for can_rx_register() for a given single can_id */
79 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
80 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
81 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
83 #define CAN_BCM_VERSION CAN_VERSION
85 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
86 MODULE_LICENSE("Dual BSD/GPL");
87 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
88 MODULE_ALIAS("can-proto-2");
90 /* easy access to can_frame payload */
91 static inline u64 GET_U64(const struct can_frame *cp)
93 return *(u64 *)cp->data;
97 struct list_head list;
101 unsigned long frames_abs, frames_filtered;
102 struct bcm_timeval ival1, ival2;
103 struct hrtimer timer, thrtimer;
104 struct tasklet_struct tsklet, thrtsklet;
105 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
110 struct can_frame *frames;
111 struct can_frame *last_frames;
112 struct can_frame sframe;
113 struct can_frame last_sframe;
115 struct net_device *rx_reg_dev;
118 static struct proc_dir_entry *proc_dir;
124 struct list_head notifier;
125 struct list_head rx_ops;
126 struct list_head tx_ops;
127 unsigned long dropped_usr_msgs;
128 struct proc_dir_entry *bcm_proc_read;
129 char procname [32]; /* inode number in decimal with \0 */
132 static LIST_HEAD(bcm_notifier_list);
133 static DEFINE_SPINLOCK(bcm_notifier_lock);
134 static struct bcm_sock *bcm_busy_notifier;
136 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
138 return (struct bcm_sock *)sk;
141 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
143 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
146 /* check limitations for timeval provided by user */
147 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
149 if ((msg_head->ival1.tv_sec < 0) ||
150 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
151 (msg_head->ival1.tv_usec < 0) ||
152 (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
153 (msg_head->ival2.tv_sec < 0) ||
154 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
155 (msg_head->ival2.tv_usec < 0) ||
156 (msg_head->ival2.tv_usec >= USEC_PER_SEC))
162 #define CFSIZ sizeof(struct can_frame)
163 #define OPSIZ sizeof(struct bcm_op)
164 #define MHSIZ sizeof(struct bcm_msg_head)
169 static char *bcm_proc_getifname(char *result, int ifindex)
171 struct net_device *dev;
177 dev = dev_get_by_index_rcu(&init_net, ifindex);
179 strcpy(result, dev->name);
181 strcpy(result, "???");
187 static int bcm_proc_show(struct seq_file *m, void *v)
189 char ifname[IFNAMSIZ];
190 struct sock *sk = (struct sock *)m->private;
191 struct bcm_sock *bo = bcm_sk(sk);
194 seq_printf(m, ">>> socket %pK", sk->sk_socket);
195 seq_printf(m, " / sk %pK", sk);
196 seq_printf(m, " / bo %pK", bo);
197 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
198 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
199 seq_printf(m, " <<<\n");
201 list_for_each_entry(op, &bo->rx_ops, list) {
203 unsigned long reduction;
205 /* print only active entries & prevent division by zero */
209 seq_printf(m, "rx_op: %03X %-5s ",
210 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
211 seq_printf(m, "[%u]%c ", op->nframes,
212 (op->flags & RX_CHECK_DLC)?'d':' ');
213 if (op->kt_ival1.tv64)
214 seq_printf(m, "timeo=%lld ",
216 ktime_to_us(op->kt_ival1));
218 if (op->kt_ival2.tv64)
219 seq_printf(m, "thr=%lld ",
221 ktime_to_us(op->kt_ival2));
223 seq_printf(m, "# recv %ld (%ld) => reduction: ",
224 op->frames_filtered, op->frames_abs);
226 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
228 seq_printf(m, "%s%ld%%\n",
229 (reduction == 100)?"near ":"", reduction);
232 list_for_each_entry(op, &bo->tx_ops, list) {
234 seq_printf(m, "tx_op: %03X %s [%u] ",
236 bcm_proc_getifname(ifname, op->ifindex),
239 if (op->kt_ival1.tv64)
240 seq_printf(m, "t1=%lld ",
241 (long long) ktime_to_us(op->kt_ival1));
243 if (op->kt_ival2.tv64)
244 seq_printf(m, "t2=%lld ",
245 (long long) ktime_to_us(op->kt_ival2));
247 seq_printf(m, "# sent %ld\n", op->frames_abs);
253 static int bcm_proc_open(struct inode *inode, struct file *file)
255 return single_open(file, bcm_proc_show, PDE_DATA(inode));
258 static const struct file_operations bcm_proc_fops = {
259 .owner = THIS_MODULE,
260 .open = bcm_proc_open,
263 .release = single_release,
267 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
268 * of the given bcm tx op
270 static void bcm_can_tx(struct bcm_op *op)
273 struct net_device *dev;
274 struct can_frame *cf = &op->frames[op->currframe];
276 /* no target device? => exit */
280 dev = dev_get_by_index(&init_net, op->ifindex);
282 /* RFC: should this bcm_op remove itself here? */
286 skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), gfp_any());
290 can_skb_reserve(skb);
291 can_skb_prv(skb)->ifindex = dev->ifindex;
292 can_skb_prv(skb)->skbcnt = 0;
294 memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
296 /* send with loopback */
298 can_skb_set_owner(skb, op->sk);
301 /* update statistics */
305 /* reached last frame? */
306 if (op->currframe >= op->nframes)
313 * bcm_send_to_user - send a BCM message to the userspace
314 * (consisting of bcm_msg_head + x CAN frames)
316 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
317 struct can_frame *frames, int has_timestamp)
320 struct can_frame *firstframe;
321 struct sockaddr_can *addr;
322 struct sock *sk = op->sk;
323 unsigned int datalen = head->nframes * CFSIZ;
326 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
330 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
333 /* can_frames starting here */
334 firstframe = (struct can_frame *)skb_tail_pointer(skb);
336 memcpy(skb_put(skb, datalen), frames, datalen);
339 * the BCM uses the can_dlc-element of the can_frame
340 * structure for internal purposes. This is only
341 * relevant for updates that are generated by the
342 * BCM, where nframes is 1
344 if (head->nframes == 1)
345 firstframe->can_dlc &= BCM_CAN_DLC_MASK;
349 /* restore rx timestamp */
350 skb->tstamp = op->rx_stamp;
354 * Put the datagram to the queue so that bcm_recvmsg() can
355 * get it from there. We need to pass the interface index to
356 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
357 * containing the interface index.
360 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
361 addr = (struct sockaddr_can *)skb->cb;
362 memset(addr, 0, sizeof(*addr));
363 addr->can_family = AF_CAN;
364 addr->can_ifindex = op->rx_ifindex;
366 err = sock_queue_rcv_skb(sk, skb);
368 struct bcm_sock *bo = bcm_sk(sk);
371 /* don't care about overflows in this statistic */
372 bo->dropped_usr_msgs++;
376 static void bcm_tx_start_timer(struct bcm_op *op)
378 if (op->kt_ival1.tv64 && op->count)
379 hrtimer_start(&op->timer,
380 ktime_add(ktime_get(), op->kt_ival1),
382 else if (op->kt_ival2.tv64)
383 hrtimer_start(&op->timer,
384 ktime_add(ktime_get(), op->kt_ival2),
388 static void bcm_tx_timeout_tsklet(unsigned long data)
390 struct bcm_op *op = (struct bcm_op *)data;
391 struct bcm_msg_head msg_head;
393 if (op->kt_ival1.tv64 && (op->count > 0)) {
396 if (!op->count && (op->flags & TX_COUNTEVT)) {
398 /* create notification to user */
399 memset(&msg_head, 0, sizeof(msg_head));
400 msg_head.opcode = TX_EXPIRED;
401 msg_head.flags = op->flags;
402 msg_head.count = op->count;
403 msg_head.ival1 = op->ival1;
404 msg_head.ival2 = op->ival2;
405 msg_head.can_id = op->can_id;
406 msg_head.nframes = 0;
408 bcm_send_to_user(op, &msg_head, NULL, 0);
412 } else if (op->kt_ival2.tv64)
415 bcm_tx_start_timer(op);
419 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
421 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
423 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
425 tasklet_schedule(&op->tsklet);
427 return HRTIMER_NORESTART;
431 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
433 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
435 struct bcm_msg_head head;
437 /* update statistics */
438 op->frames_filtered++;
440 /* prevent statistics overflow */
441 if (op->frames_filtered > ULONG_MAX/100)
442 op->frames_filtered = op->frames_abs = 0;
444 /* this element is not throttled anymore */
445 data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
447 memset(&head, 0, sizeof(head));
448 head.opcode = RX_CHANGED;
449 head.flags = op->flags;
450 head.count = op->count;
451 head.ival1 = op->ival1;
452 head.ival2 = op->ival2;
453 head.can_id = op->can_id;
456 bcm_send_to_user(op, &head, data, 1);
460 * bcm_rx_update_and_send - process a detected relevant receive content change
461 * 1. update the last received data
462 * 2. send a notification to the user (if possible)
464 static void bcm_rx_update_and_send(struct bcm_op *op,
465 struct can_frame *lastdata,
466 const struct can_frame *rxdata)
468 memcpy(lastdata, rxdata, CFSIZ);
470 /* mark as used and throttled by default */
471 lastdata->can_dlc |= (RX_RECV|RX_THR);
473 /* throttling mode inactive ? */
474 if (!op->kt_ival2.tv64) {
475 /* send RX_CHANGED to the user immediately */
476 bcm_rx_changed(op, lastdata);
480 /* with active throttling timer we are just done here */
481 if (hrtimer_active(&op->thrtimer))
484 /* first reception with enabled throttling mode */
485 if (!op->kt_lastmsg.tv64)
486 goto rx_changed_settime;
488 /* got a second frame inside a potential throttle period? */
489 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
490 ktime_to_us(op->kt_ival2)) {
491 /* do not send the saved data - only start throttle timer */
492 hrtimer_start(&op->thrtimer,
493 ktime_add(op->kt_lastmsg, op->kt_ival2),
498 /* the gap was that big, that throttling was not needed here */
500 bcm_rx_changed(op, lastdata);
501 op->kt_lastmsg = ktime_get();
505 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
506 * received data stored in op->last_frames[]
508 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
509 const struct can_frame *rxdata)
512 * no one uses the MSBs of can_dlc for comparison,
513 * so we use it here to detect the first time of reception
516 if (!(op->last_frames[index].can_dlc & RX_RECV)) {
517 /* received data for the first time => send update to user */
518 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
522 /* do a real check in can_frame data section */
524 if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
525 (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
526 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
530 if (op->flags & RX_CHECK_DLC) {
531 /* do a real check in can_frame dlc */
532 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
534 bcm_rx_update_and_send(op, &op->last_frames[index],
542 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
544 static void bcm_rx_starttimer(struct bcm_op *op)
546 if (op->flags & RX_NO_AUTOTIMER)
549 if (op->kt_ival1.tv64)
550 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
553 static void bcm_rx_timeout_tsklet(unsigned long data)
555 struct bcm_op *op = (struct bcm_op *)data;
556 struct bcm_msg_head msg_head;
558 /* create notification to user */
559 memset(&msg_head, 0, sizeof(msg_head));
560 msg_head.opcode = RX_TIMEOUT;
561 msg_head.flags = op->flags;
562 msg_head.count = op->count;
563 msg_head.ival1 = op->ival1;
564 msg_head.ival2 = op->ival2;
565 msg_head.can_id = op->can_id;
566 msg_head.nframes = 0;
568 bcm_send_to_user(op, &msg_head, NULL, 0);
572 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
574 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
576 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
578 /* schedule before NET_RX_SOFTIRQ */
579 tasklet_hi_schedule(&op->tsklet);
581 /* no restart of the timer is done here! */
583 /* if user wants to be informed, when cyclic CAN-Messages come back */
584 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
585 /* clear received can_frames to indicate 'nothing received' */
586 memset(op->last_frames, 0, op->nframes * CFSIZ);
589 return HRTIMER_NORESTART;
593 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
595 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
598 if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
600 bcm_rx_changed(op, &op->last_frames[index]);
607 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
609 * update == 0 : just check if throttled data is available (any irq context)
610 * update == 1 : check and send throttled data to userspace (soft_irq context)
612 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
616 if (op->nframes > 1) {
619 /* for MUX filter we start at index 1 */
620 for (i = 1; i < op->nframes; i++)
621 updated += bcm_rx_do_flush(op, update, i);
624 /* for RX_FILTER_ID and simple filter */
625 updated += bcm_rx_do_flush(op, update, 0);
631 static void bcm_rx_thr_tsklet(unsigned long data)
633 struct bcm_op *op = (struct bcm_op *)data;
635 /* push the changed data to the userspace */
636 bcm_rx_thr_flush(op, 1);
640 * bcm_rx_thr_handler - the time for blocked content updates is over now:
641 * Check for throttled data and send it to the userspace
643 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
645 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
647 tasklet_schedule(&op->thrtsklet);
649 if (bcm_rx_thr_flush(op, 0)) {
650 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
651 return HRTIMER_RESTART;
653 /* rearm throttle handling */
654 op->kt_lastmsg = ktime_set(0, 0);
655 return HRTIMER_NORESTART;
660 * bcm_rx_handler - handle a CAN frame reception
662 static void bcm_rx_handler(struct sk_buff *skb, void *data)
664 struct bcm_op *op = (struct bcm_op *)data;
665 const struct can_frame *rxframe = (struct can_frame *)skb->data;
668 /* disable timeout */
669 hrtimer_cancel(&op->timer);
671 if (op->can_id != rxframe->can_id)
674 /* save rx timestamp */
675 op->rx_stamp = skb->tstamp;
676 /* save originator for recvfrom() */
677 op->rx_ifindex = skb->dev->ifindex;
678 /* update statistics */
681 if (op->flags & RX_RTR_FRAME) {
682 /* send reply for RTR-request (placed in op->frames[0]) */
687 if (op->flags & RX_FILTER_ID) {
688 /* the easiest case */
689 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
693 if (op->nframes == 1) {
694 /* simple compare with index 0 */
695 bcm_rx_cmp_to_index(op, 0, rxframe);
699 if (op->nframes > 1) {
703 * find the first multiplex mask that fits.
704 * Remark: The MUX-mask is stored in index 0
707 for (i = 1; i < op->nframes; i++) {
708 if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
709 (GET_U64(&op->frames[0]) &
710 GET_U64(&op->frames[i]))) {
711 bcm_rx_cmp_to_index(op, i, rxframe);
718 bcm_rx_starttimer(op);
722 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
724 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
729 list_for_each_entry(op, ops, list) {
730 if ((op->can_id == can_id) && (op->ifindex == ifindex))
737 static void bcm_remove_op(struct bcm_op *op)
739 if (op->tsklet.func) {
740 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
741 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
742 hrtimer_active(&op->timer)) {
743 hrtimer_cancel(&op->timer);
744 tasklet_kill(&op->tsklet);
748 if (op->thrtsklet.func) {
749 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
750 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
751 hrtimer_active(&op->thrtimer)) {
752 hrtimer_cancel(&op->thrtimer);
753 tasklet_kill(&op->thrtsklet);
757 if ((op->frames) && (op->frames != &op->sframe))
760 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
761 kfree(op->last_frames);
766 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
768 if (op->rx_reg_dev == dev) {
769 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
772 /* mark as removed subscription */
773 op->rx_reg_dev = NULL;
775 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
776 "mismatch %p %p\n", op->rx_reg_dev, dev);
780 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
782 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
784 struct bcm_op *op, *n;
786 list_for_each_entry_safe(op, n, ops, list) {
787 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
790 * Don't care if we're bound or not (due to netdev
791 * problems) can_rx_unregister() is always a save
796 * Only remove subscriptions that had not
797 * been removed due to NETDEV_UNREGISTER
800 if (op->rx_reg_dev) {
801 struct net_device *dev;
803 dev = dev_get_by_index(&init_net,
806 bcm_rx_unreg(dev, op);
811 can_rx_unregister(NULL, op->can_id,
822 return 0; /* not found */
826 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
828 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
830 struct bcm_op *op, *n;
832 list_for_each_entry_safe(op, n, ops, list) {
833 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
840 return 0; /* not found */
844 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
846 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
849 struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
854 /* put current values into msg_head */
855 msg_head->flags = op->flags;
856 msg_head->count = op->count;
857 msg_head->ival1 = op->ival1;
858 msg_head->ival2 = op->ival2;
859 msg_head->nframes = op->nframes;
861 bcm_send_to_user(op, msg_head, op->frames, 0);
867 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
869 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
870 int ifindex, struct sock *sk)
872 struct bcm_sock *bo = bcm_sk(sk);
877 /* we need a real device to send frames */
881 /* check nframes boundaries - we need at least one can_frame */
882 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
885 /* check timeval limitations */
886 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
889 /* check the given can_id */
890 op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
893 /* update existing BCM operation */
896 * Do we need more space for the can_frames than currently
897 * allocated? -> This is a _really_ unusual use-case and
898 * therefore (complexity / locking) it is not supported.
900 if (msg_head->nframes > op->nframes)
903 /* update can_frames content */
904 for (i = 0; i < msg_head->nframes; i++) {
905 err = memcpy_from_msg((u8 *)&op->frames[i], msg, CFSIZ);
907 if (op->frames[i].can_dlc > 8)
913 if (msg_head->flags & TX_CP_CAN_ID) {
914 /* copy can_id into frame */
915 op->frames[i].can_id = msg_head->can_id;
920 /* insert new BCM operation for the given can_id */
922 op = kzalloc(OPSIZ, GFP_KERNEL);
926 op->can_id = msg_head->can_id;
928 /* create array for can_frames and copy the data */
929 if (msg_head->nframes > 1) {
930 op->frames = kmalloc(msg_head->nframes * CFSIZ,
937 op->frames = &op->sframe;
939 for (i = 0; i < msg_head->nframes; i++) {
940 err = memcpy_from_msg((u8 *)&op->frames[i], msg, CFSIZ);
942 if (op->frames[i].can_dlc > 8)
946 if (op->frames != &op->sframe)
952 if (msg_head->flags & TX_CP_CAN_ID) {
953 /* copy can_id into frame */
954 op->frames[i].can_id = msg_head->can_id;
958 /* tx_ops never compare with previous received messages */
959 op->last_frames = NULL;
961 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
963 op->ifindex = ifindex;
965 /* initialize uninitialized (kzalloc) structure */
966 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
967 op->timer.function = bcm_tx_timeout_handler;
969 /* initialize tasklet for tx countevent notification */
970 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
973 /* currently unused in tx_ops */
974 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
976 /* add this bcm_op to the list of the tx_ops */
977 list_add(&op->list, &bo->tx_ops);
979 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
981 if (op->nframes != msg_head->nframes) {
982 op->nframes = msg_head->nframes;
983 /* start multiple frame transmission with index 0 */
989 op->flags = msg_head->flags;
991 if (op->flags & TX_RESET_MULTI_IDX) {
992 /* start multiple frame transmission with index 0 */
996 if (op->flags & SETTIMER) {
997 /* set timer values */
998 op->count = msg_head->count;
999 op->ival1 = msg_head->ival1;
1000 op->ival2 = msg_head->ival2;
1001 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1002 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1004 /* disable an active timer due to zero values? */
1005 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
1006 hrtimer_cancel(&op->timer);
1009 if (op->flags & STARTTIMER) {
1010 hrtimer_cancel(&op->timer);
1011 /* spec: send can_frame when starting timer */
1012 op->flags |= TX_ANNOUNCE;
1015 if (op->flags & TX_ANNOUNCE) {
1021 if (op->flags & STARTTIMER)
1022 bcm_tx_start_timer(op);
1024 return msg_head->nframes * CFSIZ + MHSIZ;
1028 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1030 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1031 int ifindex, struct sock *sk)
1033 struct bcm_sock *bo = bcm_sk(sk);
1038 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1039 /* be robust against wrong usage ... */
1040 msg_head->flags |= RX_FILTER_ID;
1041 /* ignore trailing garbage */
1042 msg_head->nframes = 0;
1045 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1046 if (msg_head->nframes > MAX_NFRAMES + 1)
1049 if ((msg_head->flags & RX_RTR_FRAME) &&
1050 ((msg_head->nframes != 1) ||
1051 (!(msg_head->can_id & CAN_RTR_FLAG))))
1054 /* check timeval limitations */
1055 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1058 /* check the given can_id */
1059 op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1061 /* update existing BCM operation */
1064 * Do we need more space for the can_frames than currently
1065 * allocated? -> This is a _really_ unusual use-case and
1066 * therefore (complexity / locking) it is not supported.
1068 if (msg_head->nframes > op->nframes)
1071 if (msg_head->nframes) {
1072 /* update can_frames content */
1073 err = memcpy_from_msg((u8 *)op->frames, msg,
1074 msg_head->nframes * CFSIZ);
1078 /* clear last_frames to indicate 'nothing received' */
1079 memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1082 op->nframes = msg_head->nframes;
1084 /* Only an update -> do not call can_rx_register() */
1088 /* insert new BCM operation for the given can_id */
1089 op = kzalloc(OPSIZ, GFP_KERNEL);
1093 op->can_id = msg_head->can_id;
1094 op->nframes = msg_head->nframes;
1096 if (msg_head->nframes > 1) {
1097 /* create array for can_frames and copy the data */
1098 op->frames = kmalloc(msg_head->nframes * CFSIZ,
1105 /* create and init array for received can_frames */
1106 op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1108 if (!op->last_frames) {
1115 op->frames = &op->sframe;
1116 op->last_frames = &op->last_sframe;
1119 if (msg_head->nframes) {
1120 err = memcpy_from_msg((u8 *)op->frames, msg,
1121 msg_head->nframes * CFSIZ);
1123 if (op->frames != &op->sframe)
1125 if (op->last_frames != &op->last_sframe)
1126 kfree(op->last_frames);
1132 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1134 op->ifindex = ifindex;
1136 /* ifindex for timeout events w/o previous frame reception */
1137 op->rx_ifindex = ifindex;
1139 /* initialize uninitialized (kzalloc) structure */
1140 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1141 op->timer.function = bcm_rx_timeout_handler;
1143 /* initialize tasklet for rx timeout notification */
1144 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1145 (unsigned long) op);
1147 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1148 op->thrtimer.function = bcm_rx_thr_handler;
1150 /* initialize tasklet for rx throttle handling */
1151 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1152 (unsigned long) op);
1154 /* add this bcm_op to the list of the rx_ops */
1155 list_add(&op->list, &bo->rx_ops);
1157 /* call can_rx_register() */
1160 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1163 op->flags = msg_head->flags;
1165 if (op->flags & RX_RTR_FRAME) {
1167 /* no timers in RTR-mode */
1168 hrtimer_cancel(&op->thrtimer);
1169 hrtimer_cancel(&op->timer);
1172 * funny feature in RX(!)_SETUP only for RTR-mode:
1173 * copy can_id into frame BUT without RTR-flag to
1174 * prevent a full-load-loopback-test ... ;-]
1176 if ((op->flags & TX_CP_CAN_ID) ||
1177 (op->frames[0].can_id == op->can_id))
1178 op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1181 if (op->flags & SETTIMER) {
1183 /* set timer value */
1184 op->ival1 = msg_head->ival1;
1185 op->ival2 = msg_head->ival2;
1186 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1187 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1189 /* disable an active timer due to zero value? */
1190 if (!op->kt_ival1.tv64)
1191 hrtimer_cancel(&op->timer);
1194 * In any case cancel the throttle timer, flush
1195 * potentially blocked msgs and reset throttle handling
1197 op->kt_lastmsg = ktime_set(0, 0);
1198 hrtimer_cancel(&op->thrtimer);
1199 bcm_rx_thr_flush(op, 1);
1202 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1203 hrtimer_start(&op->timer, op->kt_ival1,
1207 /* now we can register for can_ids, if we added a new bcm_op */
1208 if (do_rx_register) {
1210 struct net_device *dev;
1212 dev = dev_get_by_index(&init_net, ifindex);
1214 err = can_rx_register(dev, op->can_id,
1215 REGMASK(op->can_id),
1219 op->rx_reg_dev = dev;
1224 err = can_rx_register(NULL, op->can_id,
1225 REGMASK(op->can_id),
1226 bcm_rx_handler, op, "bcm", sk);
1228 /* this bcm rx op is broken -> remove it */
1229 list_del(&op->list);
1235 return msg_head->nframes * CFSIZ + MHSIZ;
1239 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1241 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1243 struct sk_buff *skb;
1244 struct net_device *dev;
1247 /* we need a real device to send frames */
1251 skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), GFP_KERNEL);
1255 can_skb_reserve(skb);
1257 err = memcpy_from_msg(skb_put(skb, CFSIZ), msg, CFSIZ);
1263 dev = dev_get_by_index(&init_net, ifindex);
1269 can_skb_prv(skb)->ifindex = dev->ifindex;
1270 can_skb_prv(skb)->skbcnt = 0;
1272 can_skb_set_owner(skb, sk);
1273 err = can_send(skb, 1); /* send with loopback */
1279 return CFSIZ + MHSIZ;
1283 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1285 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1287 struct sock *sk = sock->sk;
1288 struct bcm_sock *bo = bcm_sk(sk);
1289 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1290 struct bcm_msg_head msg_head;
1291 int ret; /* read bytes or error codes as return value */
1296 /* check for valid message length from userspace */
1297 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1300 /* check for alternative ifindex for this bcm_op */
1302 if (!ifindex && msg->msg_name) {
1303 /* no bound device as default => check msg_name */
1304 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1306 if (msg->msg_namelen < sizeof(*addr))
1309 if (addr->can_family != AF_CAN)
1312 /* ifindex from sendto() */
1313 ifindex = addr->can_ifindex;
1316 struct net_device *dev;
1318 dev = dev_get_by_index(&init_net, ifindex);
1322 if (dev->type != ARPHRD_CAN) {
1331 /* read message head information */
1333 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1339 switch (msg_head.opcode) {
1342 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1346 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1350 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1357 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1364 /* reuse msg_head for the reply to TX_READ */
1365 msg_head.opcode = TX_STATUS;
1366 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1370 /* reuse msg_head for the reply to RX_READ */
1371 msg_head.opcode = RX_STATUS;
1372 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1376 /* we need exactly one can_frame behind the msg head */
1377 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1380 ret = bcm_tx_send(msg, ifindex, sk);
1394 * notification handler for netdevice status changes
1396 static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1397 struct net_device *dev)
1399 struct sock *sk = &bo->sk;
1401 int notify_enodev = 0;
1403 if (!net_eq(dev_net(dev), &init_net))
1408 case NETDEV_UNREGISTER:
1411 /* remove device specific receive entries */
1412 list_for_each_entry(op, &bo->rx_ops, list)
1413 if (op->rx_reg_dev == dev)
1414 bcm_rx_unreg(dev, op);
1416 /* remove device reference, if this is our bound device */
1417 if (bo->bound && bo->ifindex == dev->ifindex) {
1425 if (notify_enodev) {
1426 sk->sk_err = ENODEV;
1427 if (!sock_flag(sk, SOCK_DEAD))
1428 sk->sk_error_report(sk);
1433 if (bo->bound && bo->ifindex == dev->ifindex) {
1434 sk->sk_err = ENETDOWN;
1435 if (!sock_flag(sk, SOCK_DEAD))
1436 sk->sk_error_report(sk);
1441 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1444 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1446 if (dev->type != ARPHRD_CAN)
1448 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1450 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1453 spin_lock(&bcm_notifier_lock);
1454 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1455 spin_unlock(&bcm_notifier_lock);
1456 bcm_notify(bcm_busy_notifier, msg, dev);
1457 spin_lock(&bcm_notifier_lock);
1459 bcm_busy_notifier = NULL;
1460 spin_unlock(&bcm_notifier_lock);
1465 * initial settings for all BCM sockets to be set at socket creation time
1467 static int bcm_init(struct sock *sk)
1469 struct bcm_sock *bo = bcm_sk(sk);
1473 bo->dropped_usr_msgs = 0;
1474 bo->bcm_proc_read = NULL;
1476 INIT_LIST_HEAD(&bo->tx_ops);
1477 INIT_LIST_HEAD(&bo->rx_ops);
1480 spin_lock(&bcm_notifier_lock);
1481 list_add_tail(&bo->notifier, &bcm_notifier_list);
1482 spin_unlock(&bcm_notifier_lock);
1488 * standard socket functions
1490 static int bcm_release(struct socket *sock)
1492 struct sock *sk = sock->sk;
1493 struct bcm_sock *bo;
1494 struct bcm_op *op, *next;
1501 /* remove bcm_ops, timer, rx_unregister(), etc. */
1503 spin_lock(&bcm_notifier_lock);
1504 while (bcm_busy_notifier == bo) {
1505 spin_unlock(&bcm_notifier_lock);
1506 schedule_timeout_uninterruptible(1);
1507 spin_lock(&bcm_notifier_lock);
1509 list_del(&bo->notifier);
1510 spin_unlock(&bcm_notifier_lock);
1514 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1517 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1519 * Don't care if we're bound or not (due to netdev problems)
1520 * can_rx_unregister() is always a save thing to do here.
1524 * Only remove subscriptions that had not
1525 * been removed due to NETDEV_UNREGISTER
1528 if (op->rx_reg_dev) {
1529 struct net_device *dev;
1531 dev = dev_get_by_index(&init_net, op->ifindex);
1533 bcm_rx_unreg(dev, op);
1538 can_rx_unregister(NULL, op->can_id,
1539 REGMASK(op->can_id),
1540 bcm_rx_handler, op);
1546 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1549 /* remove procfs entry */
1550 if (proc_dir && bo->bcm_proc_read)
1551 remove_proc_entry(bo->procname, proc_dir);
1553 /* remove device reference */
1568 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1571 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1572 struct sock *sk = sock->sk;
1573 struct bcm_sock *bo = bcm_sk(sk);
1576 if (len < sizeof(*addr))
1586 /* bind a device to this socket */
1587 if (addr->can_ifindex) {
1588 struct net_device *dev;
1590 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1595 if (dev->type != ARPHRD_CAN) {
1601 bo->ifindex = dev->ifindex;
1605 /* no interface reference for ifindex = 0 ('any' CAN device) */
1610 /* unique socket address as filename */
1611 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1612 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1614 &bcm_proc_fops, sk);
1615 if (!bo->bcm_proc_read) {
1629 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1632 struct sock *sk = sock->sk;
1633 struct sk_buff *skb;
1638 noblock = flags & MSG_DONTWAIT;
1639 flags &= ~MSG_DONTWAIT;
1640 skb = skb_recv_datagram(sk, flags, noblock, &error);
1644 if (skb->len < size)
1647 err = memcpy_to_msg(msg, skb->data, size);
1649 skb_free_datagram(sk, skb);
1653 sock_recv_ts_and_drops(msg, sk, skb);
1655 if (msg->msg_name) {
1656 __sockaddr_check_size(sizeof(struct sockaddr_can));
1657 msg->msg_namelen = sizeof(struct sockaddr_can);
1658 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1661 skb_free_datagram(sk, skb);
1666 static const struct proto_ops bcm_ops = {
1668 .release = bcm_release,
1669 .bind = sock_no_bind,
1670 .connect = bcm_connect,
1671 .socketpair = sock_no_socketpair,
1672 .accept = sock_no_accept,
1673 .getname = sock_no_getname,
1674 .poll = datagram_poll,
1675 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1676 .listen = sock_no_listen,
1677 .shutdown = sock_no_shutdown,
1678 .setsockopt = sock_no_setsockopt,
1679 .getsockopt = sock_no_getsockopt,
1680 .sendmsg = bcm_sendmsg,
1681 .recvmsg = bcm_recvmsg,
1682 .mmap = sock_no_mmap,
1683 .sendpage = sock_no_sendpage,
1686 static struct proto bcm_proto __read_mostly = {
1688 .owner = THIS_MODULE,
1689 .obj_size = sizeof(struct bcm_sock),
1693 static const struct can_proto bcm_can_proto = {
1695 .protocol = CAN_BCM,
1700 static struct notifier_block canbcm_notifier = {
1701 .notifier_call = bcm_notifier
1704 static int __init bcm_module_init(void)
1708 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1710 err = can_proto_register(&bcm_can_proto);
1712 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1716 /* create /proc/net/can-bcm directory */
1717 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1718 register_netdevice_notifier(&canbcm_notifier);
1723 static void __exit bcm_module_exit(void)
1725 can_proto_unregister(&bcm_can_proto);
1728 remove_proc_entry("can-bcm", init_net.proc_net);
1730 unregister_netdevice_notifier(&canbcm_notifier);
1733 module_init(bcm_module_init);
1734 module_exit(bcm_module_exit);