2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 * Copyright (c) 2002-2016 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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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].flags */
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_FLAGS_MASK 0x3F /* to clean private flags after usage */
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 "20161123"
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");
91 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
92 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
93 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
95 static inline u64 get_u64(const struct canfd_frame *cp, int offset)
97 return *(u64 *)(cp->data + offset);
101 struct list_head list;
105 unsigned long frames_abs, frames_filtered;
106 struct bcm_timeval ival1, ival2;
107 struct hrtimer timer, thrtimer;
108 struct tasklet_struct tsklet, thrtsklet;
109 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
115 /* void pointers to arrays of struct can[fd]_frame */
118 struct canfd_frame sframe;
119 struct canfd_frame last_sframe;
121 struct net_device *rx_reg_dev;
124 static struct proc_dir_entry *proc_dir;
130 struct list_head notifier;
131 struct list_head rx_ops;
132 struct list_head tx_ops;
133 unsigned long dropped_usr_msgs;
134 struct proc_dir_entry *bcm_proc_read;
135 char procname [32]; /* inode number in decimal with \0 */
138 static LIST_HEAD(bcm_notifier_list);
139 static DEFINE_SPINLOCK(bcm_notifier_lock);
140 static struct bcm_sock *bcm_busy_notifier;
142 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
144 return (struct bcm_sock *)sk;
147 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
149 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
152 /* check limitations for timeval provided by user */
153 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
155 if ((msg_head->ival1.tv_sec < 0) ||
156 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
157 (msg_head->ival1.tv_usec < 0) ||
158 (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
159 (msg_head->ival2.tv_sec < 0) ||
160 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
161 (msg_head->ival2.tv_usec < 0) ||
162 (msg_head->ival2.tv_usec >= USEC_PER_SEC))
168 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
169 #define OPSIZ sizeof(struct bcm_op)
170 #define MHSIZ sizeof(struct bcm_msg_head)
175 static char *bcm_proc_getifname(char *result, int ifindex)
177 struct net_device *dev;
183 dev = dev_get_by_index_rcu(&init_net, ifindex);
185 strcpy(result, dev->name);
187 strcpy(result, "???");
193 static int bcm_proc_show(struct seq_file *m, void *v)
195 char ifname[IFNAMSIZ];
196 struct sock *sk = (struct sock *)m->private;
197 struct bcm_sock *bo = bcm_sk(sk);
200 seq_printf(m, ">>> socket %pK", sk->sk_socket);
201 seq_printf(m, " / sk %pK", sk);
202 seq_printf(m, " / bo %pK", bo);
203 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
204 seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
205 seq_printf(m, " <<<\n");
207 list_for_each_entry(op, &bo->rx_ops, list) {
209 unsigned long reduction;
211 /* print only active entries & prevent division by zero */
215 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
216 bcm_proc_getifname(ifname, op->ifindex));
218 if (op->flags & CAN_FD_FRAME)
219 seq_printf(m, "(%u)", op->nframes);
221 seq_printf(m, "[%u]", op->nframes);
223 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
225 if (op->kt_ival1.tv64)
226 seq_printf(m, "timeo=%lld ",
227 (long long)ktime_to_us(op->kt_ival1));
229 if (op->kt_ival2.tv64)
230 seq_printf(m, "thr=%lld ",
231 (long long)ktime_to_us(op->kt_ival2));
233 seq_printf(m, "# recv %ld (%ld) => reduction: ",
234 op->frames_filtered, op->frames_abs);
236 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
238 seq_printf(m, "%s%ld%%\n",
239 (reduction == 100) ? "near " : "", reduction);
242 list_for_each_entry(op, &bo->tx_ops, list) {
244 seq_printf(m, "tx_op: %03X %s ", op->can_id,
245 bcm_proc_getifname(ifname, op->ifindex));
247 if (op->flags & CAN_FD_FRAME)
248 seq_printf(m, "(%u) ", op->nframes);
250 seq_printf(m, "[%u] ", op->nframes);
252 if (op->kt_ival1.tv64)
253 seq_printf(m, "t1=%lld ",
254 (long long)ktime_to_us(op->kt_ival1));
256 if (op->kt_ival2.tv64)
257 seq_printf(m, "t2=%lld ",
258 (long long)ktime_to_us(op->kt_ival2));
260 seq_printf(m, "# sent %ld\n", op->frames_abs);
266 static int bcm_proc_open(struct inode *inode, struct file *file)
268 return single_open(file, bcm_proc_show, PDE_DATA(inode));
271 static const struct file_operations bcm_proc_fops = {
272 .owner = THIS_MODULE,
273 .open = bcm_proc_open,
276 .release = single_release,
280 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
281 * of the given bcm tx op
283 static void bcm_can_tx(struct bcm_op *op)
286 struct net_device *dev;
287 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
289 /* no target device? => exit */
293 dev = dev_get_by_index(&init_net, op->ifindex);
295 /* RFC: should this bcm_op remove itself here? */
299 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
303 can_skb_reserve(skb);
304 can_skb_prv(skb)->ifindex = dev->ifindex;
305 can_skb_prv(skb)->skbcnt = 0;
307 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz);
309 /* send with loopback */
311 can_skb_set_owner(skb, op->sk);
314 /* update statistics */
318 /* reached last frame? */
319 if (op->currframe >= op->nframes)
326 * bcm_send_to_user - send a BCM message to the userspace
327 * (consisting of bcm_msg_head + x CAN frames)
329 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
330 struct canfd_frame *frames, int has_timestamp)
333 struct canfd_frame *firstframe;
334 struct sockaddr_can *addr;
335 struct sock *sk = op->sk;
336 unsigned int datalen = head->nframes * op->cfsiz;
339 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
343 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
346 /* CAN frames starting here */
347 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
349 memcpy(skb_put(skb, datalen), frames, datalen);
352 * the BCM uses the flags-element of the canfd_frame
353 * structure for internal purposes. This is only
354 * relevant for updates that are generated by the
355 * BCM, where nframes is 1
357 if (head->nframes == 1)
358 firstframe->flags &= BCM_CAN_FLAGS_MASK;
362 /* restore rx timestamp */
363 skb->tstamp = op->rx_stamp;
367 * Put the datagram to the queue so that bcm_recvmsg() can
368 * get it from there. We need to pass the interface index to
369 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
370 * containing the interface index.
373 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
374 addr = (struct sockaddr_can *)skb->cb;
375 memset(addr, 0, sizeof(*addr));
376 addr->can_family = AF_CAN;
377 addr->can_ifindex = op->rx_ifindex;
379 err = sock_queue_rcv_skb(sk, skb);
381 struct bcm_sock *bo = bcm_sk(sk);
384 /* don't care about overflows in this statistic */
385 bo->dropped_usr_msgs++;
389 static void bcm_tx_start_timer(struct bcm_op *op)
391 if (op->kt_ival1.tv64 && op->count)
392 hrtimer_start(&op->timer,
393 ktime_add(ktime_get(), op->kt_ival1),
395 else if (op->kt_ival2.tv64)
396 hrtimer_start(&op->timer,
397 ktime_add(ktime_get(), op->kt_ival2),
401 static void bcm_tx_timeout_tsklet(unsigned long data)
403 struct bcm_op *op = (struct bcm_op *)data;
404 struct bcm_msg_head msg_head;
406 if (op->kt_ival1.tv64 && (op->count > 0)) {
409 if (!op->count && (op->flags & TX_COUNTEVT)) {
411 /* create notification to user */
412 memset(&msg_head, 0, sizeof(msg_head));
413 msg_head.opcode = TX_EXPIRED;
414 msg_head.flags = op->flags;
415 msg_head.count = op->count;
416 msg_head.ival1 = op->ival1;
417 msg_head.ival2 = op->ival2;
418 msg_head.can_id = op->can_id;
419 msg_head.nframes = 0;
421 bcm_send_to_user(op, &msg_head, NULL, 0);
425 } else if (op->kt_ival2.tv64)
428 bcm_tx_start_timer(op);
432 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
434 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
436 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
438 tasklet_schedule(&op->tsklet);
440 return HRTIMER_NORESTART;
444 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
446 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
448 struct bcm_msg_head head;
450 /* update statistics */
451 op->frames_filtered++;
453 /* prevent statistics overflow */
454 if (op->frames_filtered > ULONG_MAX/100)
455 op->frames_filtered = op->frames_abs = 0;
457 /* this element is not throttled anymore */
458 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
460 memset(&head, 0, sizeof(head));
461 head.opcode = RX_CHANGED;
462 head.flags = op->flags;
463 head.count = op->count;
464 head.ival1 = op->ival1;
465 head.ival2 = op->ival2;
466 head.can_id = op->can_id;
469 bcm_send_to_user(op, &head, data, 1);
473 * bcm_rx_update_and_send - process a detected relevant receive content change
474 * 1. update the last received data
475 * 2. send a notification to the user (if possible)
477 static void bcm_rx_update_and_send(struct bcm_op *op,
478 struct canfd_frame *lastdata,
479 const struct canfd_frame *rxdata)
481 memcpy(lastdata, rxdata, op->cfsiz);
483 /* mark as used and throttled by default */
484 lastdata->flags |= (RX_RECV|RX_THR);
486 /* throttling mode inactive ? */
487 if (!op->kt_ival2.tv64) {
488 /* send RX_CHANGED to the user immediately */
489 bcm_rx_changed(op, lastdata);
493 /* with active throttling timer we are just done here */
494 if (hrtimer_active(&op->thrtimer))
497 /* first reception with enabled throttling mode */
498 if (!op->kt_lastmsg.tv64)
499 goto rx_changed_settime;
501 /* got a second frame inside a potential throttle period? */
502 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
503 ktime_to_us(op->kt_ival2)) {
504 /* do not send the saved data - only start throttle timer */
505 hrtimer_start(&op->thrtimer,
506 ktime_add(op->kt_lastmsg, op->kt_ival2),
511 /* the gap was that big, that throttling was not needed here */
513 bcm_rx_changed(op, lastdata);
514 op->kt_lastmsg = ktime_get();
518 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
519 * received data stored in op->last_frames[]
521 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
522 const struct canfd_frame *rxdata)
524 struct canfd_frame *cf = op->frames + op->cfsiz * index;
525 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
529 * no one uses the MSBs of flags for comparison,
530 * so we use it here to detect the first time of reception
533 if (!(lcf->flags & RX_RECV)) {
534 /* received data for the first time => send update to user */
535 bcm_rx_update_and_send(op, lcf, rxdata);
539 /* do a real check in CAN frame data section */
540 for (i = 0; i < rxdata->len; i += 8) {
541 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
542 (get_u64(cf, i) & get_u64(lcf, i))) {
543 bcm_rx_update_and_send(op, lcf, rxdata);
548 if (op->flags & RX_CHECK_DLC) {
549 /* do a real check in CAN frame length */
550 if (rxdata->len != lcf->len) {
551 bcm_rx_update_and_send(op, lcf, rxdata);
558 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
560 static void bcm_rx_starttimer(struct bcm_op *op)
562 if (op->flags & RX_NO_AUTOTIMER)
565 if (op->kt_ival1.tv64)
566 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
569 static void bcm_rx_timeout_tsklet(unsigned long data)
571 struct bcm_op *op = (struct bcm_op *)data;
572 struct bcm_msg_head msg_head;
574 /* create notification to user */
575 memset(&msg_head, 0, sizeof(msg_head));
576 msg_head.opcode = RX_TIMEOUT;
577 msg_head.flags = op->flags;
578 msg_head.count = op->count;
579 msg_head.ival1 = op->ival1;
580 msg_head.ival2 = op->ival2;
581 msg_head.can_id = op->can_id;
582 msg_head.nframes = 0;
584 bcm_send_to_user(op, &msg_head, NULL, 0);
588 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
590 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
592 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
594 /* schedule before NET_RX_SOFTIRQ */
595 tasklet_hi_schedule(&op->tsklet);
597 /* no restart of the timer is done here! */
599 /* if user wants to be informed, when cyclic CAN-Messages come back */
600 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
601 /* clear received CAN frames to indicate 'nothing received' */
602 memset(op->last_frames, 0, op->nframes * op->cfsiz);
605 return HRTIMER_NORESTART;
609 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
611 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
614 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
616 if ((op->last_frames) && (lcf->flags & RX_THR)) {
618 bcm_rx_changed(op, lcf);
625 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
627 * update == 0 : just check if throttled data is available (any irq context)
628 * update == 1 : check and send throttled data to userspace (soft_irq context)
630 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
634 if (op->nframes > 1) {
637 /* for MUX filter we start at index 1 */
638 for (i = 1; i < op->nframes; i++)
639 updated += bcm_rx_do_flush(op, update, i);
642 /* for RX_FILTER_ID and simple filter */
643 updated += bcm_rx_do_flush(op, update, 0);
649 static void bcm_rx_thr_tsklet(unsigned long data)
651 struct bcm_op *op = (struct bcm_op *)data;
653 /* push the changed data to the userspace */
654 bcm_rx_thr_flush(op, 1);
658 * bcm_rx_thr_handler - the time for blocked content updates is over now:
659 * Check for throttled data and send it to the userspace
661 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
663 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
665 tasklet_schedule(&op->thrtsklet);
667 if (bcm_rx_thr_flush(op, 0)) {
668 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
669 return HRTIMER_RESTART;
671 /* rearm throttle handling */
672 op->kt_lastmsg = ktime_set(0, 0);
673 return HRTIMER_NORESTART;
678 * bcm_rx_handler - handle a CAN frame reception
680 static void bcm_rx_handler(struct sk_buff *skb, void *data)
682 struct bcm_op *op = (struct bcm_op *)data;
683 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
686 if (op->can_id != rxframe->can_id)
689 /* make sure to handle the correct frame type (CAN / CAN FD) */
690 if (skb->len != op->cfsiz)
693 /* disable timeout */
694 hrtimer_cancel(&op->timer);
696 /* save rx timestamp */
697 op->rx_stamp = skb->tstamp;
698 /* save originator for recvfrom() */
699 op->rx_ifindex = skb->dev->ifindex;
700 /* update statistics */
703 if (op->flags & RX_RTR_FRAME) {
704 /* send reply for RTR-request (placed in op->frames[0]) */
709 if (op->flags & RX_FILTER_ID) {
710 /* the easiest case */
711 bcm_rx_update_and_send(op, op->last_frames, rxframe);
715 if (op->nframes == 1) {
716 /* simple compare with index 0 */
717 bcm_rx_cmp_to_index(op, 0, rxframe);
721 if (op->nframes > 1) {
725 * find the first multiplex mask that fits.
726 * Remark: The MUX-mask is stored in index 0 - but only the
727 * first 64 bits of the frame data[] are relevant (CAN FD)
730 for (i = 1; i < op->nframes; i++) {
731 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
732 (get_u64(op->frames, 0) &
733 get_u64(op->frames + op->cfsiz * i, 0))) {
734 bcm_rx_cmp_to_index(op, i, rxframe);
741 bcm_rx_starttimer(op);
745 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
747 static struct bcm_op *bcm_find_op(struct list_head *ops,
748 struct bcm_msg_head *mh, int ifindex)
752 list_for_each_entry(op, ops, list) {
753 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
754 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
761 static void bcm_remove_op(struct bcm_op *op)
763 if (op->tsklet.func) {
765 tasklet_kill(&op->tsklet);
766 hrtimer_cancel(&op->timer);
767 } while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
768 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
769 hrtimer_active(&op->timer));
772 if (op->thrtsklet.func) {
774 tasklet_kill(&op->thrtsklet);
775 hrtimer_cancel(&op->thrtimer);
776 } while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
777 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
778 hrtimer_active(&op->thrtimer));
781 if ((op->frames) && (op->frames != &op->sframe))
784 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
785 kfree(op->last_frames);
790 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
792 if (op->rx_reg_dev == dev) {
793 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
796 /* mark as removed subscription */
797 op->rx_reg_dev = NULL;
799 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
800 "mismatch %p %p\n", op->rx_reg_dev, dev);
804 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
806 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
809 struct bcm_op *op, *n;
811 list_for_each_entry_safe(op, n, ops, list) {
812 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
813 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
816 * Don't care if we're bound or not (due to netdev
817 * problems) can_rx_unregister() is always a save
822 * Only remove subscriptions that had not
823 * been removed due to NETDEV_UNREGISTER
826 if (op->rx_reg_dev) {
827 struct net_device *dev;
829 dev = dev_get_by_index(&init_net,
832 bcm_rx_unreg(dev, op);
837 can_rx_unregister(NULL, op->can_id,
848 return 0; /* not found */
852 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
854 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
857 struct bcm_op *op, *n;
859 list_for_each_entry_safe(op, n, ops, list) {
860 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
861 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
868 return 0; /* not found */
872 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
874 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
877 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
882 /* put current values into msg_head */
883 msg_head->flags = op->flags;
884 msg_head->count = op->count;
885 msg_head->ival1 = op->ival1;
886 msg_head->ival2 = op->ival2;
887 msg_head->nframes = op->nframes;
889 bcm_send_to_user(op, msg_head, op->frames, 0);
895 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
897 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
898 int ifindex, struct sock *sk)
900 struct bcm_sock *bo = bcm_sk(sk);
902 struct canfd_frame *cf;
906 /* we need a real device to send frames */
910 /* check nframes boundaries - we need at least one CAN frame */
911 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
914 /* check timeval limitations */
915 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
918 /* check the given can_id */
919 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
921 /* update existing BCM operation */
924 * Do we need more space for the CAN frames than currently
925 * allocated? -> This is a _really_ unusual use-case and
926 * therefore (complexity / locking) it is not supported.
928 if (msg_head->nframes > op->nframes)
931 /* update CAN frames content */
932 for (i = 0; i < msg_head->nframes; i++) {
934 cf = op->frames + op->cfsiz * i;
935 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
937 if (op->flags & CAN_FD_FRAME) {
948 if (msg_head->flags & TX_CP_CAN_ID) {
949 /* copy can_id into frame */
950 cf->can_id = msg_head->can_id;
953 op->flags = msg_head->flags;
956 /* insert new BCM operation for the given can_id */
958 op = kzalloc(OPSIZ, GFP_KERNEL);
962 op->can_id = msg_head->can_id;
963 op->cfsiz = CFSIZ(msg_head->flags);
964 op->flags = msg_head->flags;
966 /* create array for CAN frames and copy the data */
967 if (msg_head->nframes > 1) {
968 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
975 op->frames = &op->sframe;
977 for (i = 0; i < msg_head->nframes; i++) {
979 cf = op->frames + op->cfsiz * i;
980 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
982 if (op->flags & CAN_FD_FRAME) {
991 if (op->frames != &op->sframe)
997 if (msg_head->flags & TX_CP_CAN_ID) {
998 /* copy can_id into frame */
999 cf->can_id = msg_head->can_id;
1003 /* tx_ops never compare with previous received messages */
1004 op->last_frames = NULL;
1006 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1008 op->ifindex = ifindex;
1010 /* initialize uninitialized (kzalloc) structure */
1011 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1012 op->timer.function = bcm_tx_timeout_handler;
1014 /* initialize tasklet for tx countevent notification */
1015 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
1016 (unsigned long) op);
1018 /* currently unused in tx_ops */
1019 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1021 /* add this bcm_op to the list of the tx_ops */
1022 list_add(&op->list, &bo->tx_ops);
1024 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
1026 if (op->nframes != msg_head->nframes) {
1027 op->nframes = msg_head->nframes;
1028 /* start multiple frame transmission with index 0 */
1034 if (op->flags & TX_RESET_MULTI_IDX) {
1035 /* start multiple frame transmission with index 0 */
1039 if (op->flags & SETTIMER) {
1040 /* set timer values */
1041 op->count = msg_head->count;
1042 op->ival1 = msg_head->ival1;
1043 op->ival2 = msg_head->ival2;
1044 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1045 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1047 /* disable an active timer due to zero values? */
1048 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
1049 hrtimer_cancel(&op->timer);
1052 if (op->flags & STARTTIMER) {
1053 hrtimer_cancel(&op->timer);
1054 /* spec: send CAN frame when starting timer */
1055 op->flags |= TX_ANNOUNCE;
1058 if (op->flags & TX_ANNOUNCE) {
1064 if (op->flags & STARTTIMER)
1065 bcm_tx_start_timer(op);
1067 return msg_head->nframes * op->cfsiz + MHSIZ;
1071 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1073 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1074 int ifindex, struct sock *sk)
1076 struct bcm_sock *bo = bcm_sk(sk);
1081 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1082 /* be robust against wrong usage ... */
1083 msg_head->flags |= RX_FILTER_ID;
1084 /* ignore trailing garbage */
1085 msg_head->nframes = 0;
1088 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1089 if (msg_head->nframes > MAX_NFRAMES + 1)
1092 if ((msg_head->flags & RX_RTR_FRAME) &&
1093 ((msg_head->nframes != 1) ||
1094 (!(msg_head->can_id & CAN_RTR_FLAG))))
1097 /* check timeval limitations */
1098 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1101 /* check the given can_id */
1102 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1104 /* update existing BCM operation */
1107 * Do we need more space for the CAN frames than currently
1108 * allocated? -> This is a _really_ unusual use-case and
1109 * therefore (complexity / locking) it is not supported.
1111 if (msg_head->nframes > op->nframes)
1114 if (msg_head->nframes) {
1115 /* update CAN frames content */
1116 err = memcpy_from_msg(op->frames, msg,
1117 msg_head->nframes * op->cfsiz);
1121 /* clear last_frames to indicate 'nothing received' */
1122 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1125 op->nframes = msg_head->nframes;
1126 op->flags = msg_head->flags;
1128 /* Only an update -> do not call can_rx_register() */
1132 /* insert new BCM operation for the given can_id */
1133 op = kzalloc(OPSIZ, GFP_KERNEL);
1137 op->can_id = msg_head->can_id;
1138 op->nframes = msg_head->nframes;
1139 op->cfsiz = CFSIZ(msg_head->flags);
1140 op->flags = msg_head->flags;
1142 if (msg_head->nframes > 1) {
1143 /* create array for CAN frames and copy the data */
1144 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1151 /* create and init array for received CAN frames */
1152 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1154 if (!op->last_frames) {
1161 op->frames = &op->sframe;
1162 op->last_frames = &op->last_sframe;
1165 if (msg_head->nframes) {
1166 err = memcpy_from_msg(op->frames, msg,
1167 msg_head->nframes * op->cfsiz);
1169 if (op->frames != &op->sframe)
1171 if (op->last_frames != &op->last_sframe)
1172 kfree(op->last_frames);
1178 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1180 op->ifindex = ifindex;
1182 /* ifindex for timeout events w/o previous frame reception */
1183 op->rx_ifindex = ifindex;
1185 /* initialize uninitialized (kzalloc) structure */
1186 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1187 op->timer.function = bcm_rx_timeout_handler;
1189 /* initialize tasklet for rx timeout notification */
1190 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1191 (unsigned long) op);
1193 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1194 op->thrtimer.function = bcm_rx_thr_handler;
1196 /* initialize tasklet for rx throttle handling */
1197 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1198 (unsigned long) op);
1200 /* add this bcm_op to the list of the rx_ops */
1201 list_add(&op->list, &bo->rx_ops);
1203 /* call can_rx_register() */
1206 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1210 if (op->flags & RX_RTR_FRAME) {
1211 struct canfd_frame *frame0 = op->frames;
1213 /* no timers in RTR-mode */
1214 hrtimer_cancel(&op->thrtimer);
1215 hrtimer_cancel(&op->timer);
1218 * funny feature in RX(!)_SETUP only for RTR-mode:
1219 * copy can_id into frame BUT without RTR-flag to
1220 * prevent a full-load-loopback-test ... ;-]
1222 if ((op->flags & TX_CP_CAN_ID) ||
1223 (frame0->can_id == op->can_id))
1224 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1227 if (op->flags & SETTIMER) {
1229 /* set timer value */
1230 op->ival1 = msg_head->ival1;
1231 op->ival2 = msg_head->ival2;
1232 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1233 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1235 /* disable an active timer due to zero value? */
1236 if (!op->kt_ival1.tv64)
1237 hrtimer_cancel(&op->timer);
1240 * In any case cancel the throttle timer, flush
1241 * potentially blocked msgs and reset throttle handling
1243 op->kt_lastmsg = ktime_set(0, 0);
1244 hrtimer_cancel(&op->thrtimer);
1245 bcm_rx_thr_flush(op, 1);
1248 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1249 hrtimer_start(&op->timer, op->kt_ival1,
1253 /* now we can register for can_ids, if we added a new bcm_op */
1254 if (do_rx_register) {
1256 struct net_device *dev;
1258 dev = dev_get_by_index(&init_net, ifindex);
1260 err = can_rx_register(dev, op->can_id,
1261 REGMASK(op->can_id),
1265 op->rx_reg_dev = dev;
1270 err = can_rx_register(NULL, op->can_id,
1271 REGMASK(op->can_id),
1272 bcm_rx_handler, op, "bcm", sk);
1274 /* this bcm rx op is broken -> remove it */
1275 list_del(&op->list);
1281 return msg_head->nframes * op->cfsiz + MHSIZ;
1285 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1287 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1290 struct sk_buff *skb;
1291 struct net_device *dev;
1294 /* we need a real device to send frames */
1298 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1302 can_skb_reserve(skb);
1304 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1310 dev = dev_get_by_index(&init_net, ifindex);
1316 can_skb_prv(skb)->ifindex = dev->ifindex;
1317 can_skb_prv(skb)->skbcnt = 0;
1319 can_skb_set_owner(skb, sk);
1320 err = can_send(skb, 1); /* send with loopback */
1326 return cfsiz + MHSIZ;
1330 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1332 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1334 struct sock *sk = sock->sk;
1335 struct bcm_sock *bo = bcm_sk(sk);
1336 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1337 struct bcm_msg_head msg_head;
1339 int ret; /* read bytes or error codes as return value */
1344 /* check for valid message length from userspace */
1348 /* read message head information */
1349 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1353 cfsiz = CFSIZ(msg_head.flags);
1354 if ((size - MHSIZ) % cfsiz)
1357 /* check for alternative ifindex for this bcm_op */
1359 if (!ifindex && msg->msg_name) {
1360 /* no bound device as default => check msg_name */
1361 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1363 if (msg->msg_namelen < sizeof(*addr))
1366 if (addr->can_family != AF_CAN)
1369 /* ifindex from sendto() */
1370 ifindex = addr->can_ifindex;
1373 struct net_device *dev;
1375 dev = dev_get_by_index(&init_net, ifindex);
1379 if (dev->type != ARPHRD_CAN) {
1390 switch (msg_head.opcode) {
1393 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1397 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1401 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1408 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1415 /* reuse msg_head for the reply to TX_READ */
1416 msg_head.opcode = TX_STATUS;
1417 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1421 /* reuse msg_head for the reply to RX_READ */
1422 msg_head.opcode = RX_STATUS;
1423 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1427 /* we need exactly one CAN frame behind the msg head */
1428 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1431 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1445 * notification handler for netdevice status changes
1447 static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1448 struct net_device *dev)
1450 struct sock *sk = &bo->sk;
1452 int notify_enodev = 0;
1454 if (!net_eq(dev_net(dev), &init_net))
1459 case NETDEV_UNREGISTER:
1462 /* remove device specific receive entries */
1463 list_for_each_entry(op, &bo->rx_ops, list)
1464 if (op->rx_reg_dev == dev)
1465 bcm_rx_unreg(dev, op);
1467 /* remove device reference, if this is our bound device */
1468 if (bo->bound && bo->ifindex == dev->ifindex) {
1476 if (notify_enodev) {
1477 sk->sk_err = ENODEV;
1478 if (!sock_flag(sk, SOCK_DEAD))
1479 sk->sk_error_report(sk);
1484 if (bo->bound && bo->ifindex == dev->ifindex) {
1485 sk->sk_err = ENETDOWN;
1486 if (!sock_flag(sk, SOCK_DEAD))
1487 sk->sk_error_report(sk);
1492 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1495 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1497 if (dev->type != ARPHRD_CAN)
1499 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1501 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1504 spin_lock(&bcm_notifier_lock);
1505 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1506 spin_unlock(&bcm_notifier_lock);
1507 bcm_notify(bcm_busy_notifier, msg, dev);
1508 spin_lock(&bcm_notifier_lock);
1510 bcm_busy_notifier = NULL;
1511 spin_unlock(&bcm_notifier_lock);
1516 * initial settings for all BCM sockets to be set at socket creation time
1518 static int bcm_init(struct sock *sk)
1520 struct bcm_sock *bo = bcm_sk(sk);
1524 bo->dropped_usr_msgs = 0;
1525 bo->bcm_proc_read = NULL;
1527 INIT_LIST_HEAD(&bo->tx_ops);
1528 INIT_LIST_HEAD(&bo->rx_ops);
1531 spin_lock(&bcm_notifier_lock);
1532 list_add_tail(&bo->notifier, &bcm_notifier_list);
1533 spin_unlock(&bcm_notifier_lock);
1539 * standard socket functions
1541 static int bcm_release(struct socket *sock)
1543 struct sock *sk = sock->sk;
1544 struct bcm_sock *bo;
1545 struct bcm_op *op, *next;
1552 /* remove bcm_ops, timer, rx_unregister(), etc. */
1554 spin_lock(&bcm_notifier_lock);
1555 while (bcm_busy_notifier == bo) {
1556 spin_unlock(&bcm_notifier_lock);
1557 schedule_timeout_uninterruptible(1);
1558 spin_lock(&bcm_notifier_lock);
1560 list_del(&bo->notifier);
1561 spin_unlock(&bcm_notifier_lock);
1565 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1568 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1570 * Don't care if we're bound or not (due to netdev problems)
1571 * can_rx_unregister() is always a save thing to do here.
1575 * Only remove subscriptions that had not
1576 * been removed due to NETDEV_UNREGISTER
1579 if (op->rx_reg_dev) {
1580 struct net_device *dev;
1582 dev = dev_get_by_index(&init_net, op->ifindex);
1584 bcm_rx_unreg(dev, op);
1589 can_rx_unregister(NULL, op->can_id,
1590 REGMASK(op->can_id),
1591 bcm_rx_handler, op);
1597 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1600 /* remove procfs entry */
1601 if (proc_dir && bo->bcm_proc_read)
1602 remove_proc_entry(bo->procname, proc_dir);
1604 /* remove device reference */
1619 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1622 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1623 struct sock *sk = sock->sk;
1624 struct bcm_sock *bo = bcm_sk(sk);
1627 if (len < sizeof(*addr))
1637 /* bind a device to this socket */
1638 if (addr->can_ifindex) {
1639 struct net_device *dev;
1641 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1646 if (dev->type != ARPHRD_CAN) {
1652 bo->ifindex = dev->ifindex;
1656 /* no interface reference for ifindex = 0 ('any' CAN device) */
1661 /* unique socket address as filename */
1662 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1663 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1665 &bcm_proc_fops, sk);
1666 if (!bo->bcm_proc_read) {
1680 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1683 struct sock *sk = sock->sk;
1684 struct sk_buff *skb;
1689 noblock = flags & MSG_DONTWAIT;
1690 flags &= ~MSG_DONTWAIT;
1691 skb = skb_recv_datagram(sk, flags, noblock, &error);
1695 if (skb->len < size)
1698 err = memcpy_to_msg(msg, skb->data, size);
1700 skb_free_datagram(sk, skb);
1704 sock_recv_ts_and_drops(msg, sk, skb);
1706 if (msg->msg_name) {
1707 __sockaddr_check_size(sizeof(struct sockaddr_can));
1708 msg->msg_namelen = sizeof(struct sockaddr_can);
1709 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1712 skb_free_datagram(sk, skb);
1717 static const struct proto_ops bcm_ops = {
1719 .release = bcm_release,
1720 .bind = sock_no_bind,
1721 .connect = bcm_connect,
1722 .socketpair = sock_no_socketpair,
1723 .accept = sock_no_accept,
1724 .getname = sock_no_getname,
1725 .poll = datagram_poll,
1726 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1727 .listen = sock_no_listen,
1728 .shutdown = sock_no_shutdown,
1729 .setsockopt = sock_no_setsockopt,
1730 .getsockopt = sock_no_getsockopt,
1731 .sendmsg = bcm_sendmsg,
1732 .recvmsg = bcm_recvmsg,
1733 .mmap = sock_no_mmap,
1734 .sendpage = sock_no_sendpage,
1737 static struct proto bcm_proto __read_mostly = {
1739 .owner = THIS_MODULE,
1740 .obj_size = sizeof(struct bcm_sock),
1744 static const struct can_proto bcm_can_proto = {
1746 .protocol = CAN_BCM,
1751 static struct notifier_block canbcm_notifier = {
1752 .notifier_call = bcm_notifier
1755 static int __init bcm_module_init(void)
1759 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1761 err = can_proto_register(&bcm_can_proto);
1763 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1767 /* create /proc/net/can-bcm directory */
1768 proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1769 register_netdevice_notifier(&canbcm_notifier);
1774 static void __exit bcm_module_exit(void)
1776 can_proto_unregister(&bcm_can_proto);
1779 remove_proc_entry("can-bcm", init_net.proc_net);
1781 unregister_netdevice_notifier(&canbcm_notifier);
1784 module_init(bcm_module_init);
1785 module_exit(bcm_module_exit);