2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 * Copyright (c) 2002-2017 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
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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 /* use of last_frames[index].flags */
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_FLAGS_MASK 0x3F /* to clean private flags after usage */
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 "20170425"
82 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
83 MODULE_LICENSE("Dual BSD/GPL");
84 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
85 MODULE_ALIAS("can-proto-2");
88 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
89 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
90 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
92 static inline u64 get_u64(const struct canfd_frame *cp, int offset)
94 return *(u64 *)(cp->data + offset);
98 struct list_head list;
102 unsigned long frames_abs, frames_filtered;
103 struct bcm_timeval ival1, ival2;
104 struct hrtimer timer, thrtimer;
105 struct tasklet_struct tsklet, thrtsklet;
106 ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
112 /* void pointers to arrays of struct can[fd]_frame */
115 struct canfd_frame sframe;
116 struct canfd_frame last_sframe;
118 struct net_device *rx_reg_dev;
125 struct notifier_block notifier;
126 struct list_head rx_ops;
127 struct list_head tx_ops;
128 unsigned long dropped_usr_msgs;
129 struct proc_dir_entry *bcm_proc_read;
130 char procname [32]; /* inode number in decimal with \0 */
133 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
135 return (struct bcm_sock *)sk;
138 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
140 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
143 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
144 #define OPSIZ sizeof(struct bcm_op)
145 #define MHSIZ sizeof(struct bcm_msg_head)
150 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
152 struct net_device *dev;
158 dev = dev_get_by_index_rcu(net, ifindex);
160 strcpy(result, dev->name);
162 strcpy(result, "???");
168 static int bcm_proc_show(struct seq_file *m, void *v)
170 char ifname[IFNAMSIZ];
171 struct net *net = m->private;
172 struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
173 struct bcm_sock *bo = bcm_sk(sk);
176 seq_printf(m, ">>> socket %pK", sk->sk_socket);
177 seq_printf(m, " / sk %pK", sk);
178 seq_printf(m, " / bo %pK", bo);
179 seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
180 seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
181 seq_printf(m, " <<<\n");
183 list_for_each_entry(op, &bo->rx_ops, list) {
185 unsigned long reduction;
187 /* print only active entries & prevent division by zero */
191 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
192 bcm_proc_getifname(net, ifname, op->ifindex));
194 if (op->flags & CAN_FD_FRAME)
195 seq_printf(m, "(%u)", op->nframes);
197 seq_printf(m, "[%u]", op->nframes);
199 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
202 seq_printf(m, "timeo=%lld ",
203 (long long)ktime_to_us(op->kt_ival1));
206 seq_printf(m, "thr=%lld ",
207 (long long)ktime_to_us(op->kt_ival2));
209 seq_printf(m, "# recv %ld (%ld) => reduction: ",
210 op->frames_filtered, op->frames_abs);
212 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
214 seq_printf(m, "%s%ld%%\n",
215 (reduction == 100) ? "near " : "", reduction);
218 list_for_each_entry(op, &bo->tx_ops, list) {
220 seq_printf(m, "tx_op: %03X %s ", op->can_id,
221 bcm_proc_getifname(net, ifname, op->ifindex));
223 if (op->flags & CAN_FD_FRAME)
224 seq_printf(m, "(%u) ", op->nframes);
226 seq_printf(m, "[%u] ", op->nframes);
229 seq_printf(m, "t1=%lld ",
230 (long long)ktime_to_us(op->kt_ival1));
233 seq_printf(m, "t2=%lld ",
234 (long long)ktime_to_us(op->kt_ival2));
236 seq_printf(m, "# sent %ld\n", op->frames_abs);
242 static int bcm_proc_open(struct inode *inode, struct file *file)
244 return single_open_net(inode, file, bcm_proc_show);
247 static const struct file_operations bcm_proc_fops = {
248 .owner = THIS_MODULE,
249 .open = bcm_proc_open,
252 .release = single_release,
256 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
257 * of the given bcm tx op
259 static void bcm_can_tx(struct bcm_op *op)
262 struct net_device *dev;
263 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
265 /* no target device? => exit */
269 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
271 /* RFC: should this bcm_op remove itself here? */
275 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
279 can_skb_reserve(skb);
280 can_skb_prv(skb)->ifindex = dev->ifindex;
281 can_skb_prv(skb)->skbcnt = 0;
283 memcpy(skb_put(skb, op->cfsiz), cf, op->cfsiz);
285 /* send with loopback */
287 can_skb_set_owner(skb, op->sk);
290 /* update statistics */
294 /* reached last frame? */
295 if (op->currframe >= op->nframes)
302 * bcm_send_to_user - send a BCM message to the userspace
303 * (consisting of bcm_msg_head + x CAN frames)
305 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
306 struct canfd_frame *frames, int has_timestamp)
309 struct canfd_frame *firstframe;
310 struct sockaddr_can *addr;
311 struct sock *sk = op->sk;
312 unsigned int datalen = head->nframes * op->cfsiz;
315 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
319 memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
322 /* CAN frames starting here */
323 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
325 memcpy(skb_put(skb, datalen), frames, datalen);
328 * the BCM uses the flags-element of the canfd_frame
329 * structure for internal purposes. This is only
330 * relevant for updates that are generated by the
331 * BCM, where nframes is 1
333 if (head->nframes == 1)
334 firstframe->flags &= BCM_CAN_FLAGS_MASK;
338 /* restore rx timestamp */
339 skb->tstamp = op->rx_stamp;
343 * Put the datagram to the queue so that bcm_recvmsg() can
344 * get it from there. We need to pass the interface index to
345 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
346 * containing the interface index.
349 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
350 addr = (struct sockaddr_can *)skb->cb;
351 memset(addr, 0, sizeof(*addr));
352 addr->can_family = AF_CAN;
353 addr->can_ifindex = op->rx_ifindex;
355 err = sock_queue_rcv_skb(sk, skb);
357 struct bcm_sock *bo = bcm_sk(sk);
360 /* don't care about overflows in this statistic */
361 bo->dropped_usr_msgs++;
365 static void bcm_tx_start_timer(struct bcm_op *op)
367 if (op->kt_ival1 && op->count)
368 hrtimer_start(&op->timer,
369 ktime_add(ktime_get(), op->kt_ival1),
371 else if (op->kt_ival2)
372 hrtimer_start(&op->timer,
373 ktime_add(ktime_get(), op->kt_ival2),
377 static void bcm_tx_timeout_tsklet(unsigned long data)
379 struct bcm_op *op = (struct bcm_op *)data;
380 struct bcm_msg_head msg_head;
382 if (op->kt_ival1 && (op->count > 0)) {
385 if (!op->count && (op->flags & TX_COUNTEVT)) {
387 /* create notification to user */
388 msg_head.opcode = TX_EXPIRED;
389 msg_head.flags = op->flags;
390 msg_head.count = op->count;
391 msg_head.ival1 = op->ival1;
392 msg_head.ival2 = op->ival2;
393 msg_head.can_id = op->can_id;
394 msg_head.nframes = 0;
396 bcm_send_to_user(op, &msg_head, NULL, 0);
400 } else if (op->kt_ival2)
403 bcm_tx_start_timer(op);
407 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
409 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
411 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
413 tasklet_schedule(&op->tsklet);
415 return HRTIMER_NORESTART;
419 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
421 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
423 struct bcm_msg_head head;
425 /* update statistics */
426 op->frames_filtered++;
428 /* prevent statistics overflow */
429 if (op->frames_filtered > ULONG_MAX/100)
430 op->frames_filtered = op->frames_abs = 0;
432 /* this element is not throttled anymore */
433 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
435 head.opcode = RX_CHANGED;
436 head.flags = op->flags;
437 head.count = op->count;
438 head.ival1 = op->ival1;
439 head.ival2 = op->ival2;
440 head.can_id = op->can_id;
443 bcm_send_to_user(op, &head, data, 1);
447 * bcm_rx_update_and_send - process a detected relevant receive content change
448 * 1. update the last received data
449 * 2. send a notification to the user (if possible)
451 static void bcm_rx_update_and_send(struct bcm_op *op,
452 struct canfd_frame *lastdata,
453 const struct canfd_frame *rxdata)
455 memcpy(lastdata, rxdata, op->cfsiz);
457 /* mark as used and throttled by default */
458 lastdata->flags |= (RX_RECV|RX_THR);
460 /* throttling mode inactive ? */
462 /* send RX_CHANGED to the user immediately */
463 bcm_rx_changed(op, lastdata);
467 /* with active throttling timer we are just done here */
468 if (hrtimer_active(&op->thrtimer))
471 /* first reception with enabled throttling mode */
473 goto rx_changed_settime;
475 /* got a second frame inside a potential throttle period? */
476 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
477 ktime_to_us(op->kt_ival2)) {
478 /* do not send the saved data - only start throttle timer */
479 hrtimer_start(&op->thrtimer,
480 ktime_add(op->kt_lastmsg, op->kt_ival2),
485 /* the gap was that big, that throttling was not needed here */
487 bcm_rx_changed(op, lastdata);
488 op->kt_lastmsg = ktime_get();
492 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
493 * received data stored in op->last_frames[]
495 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
496 const struct canfd_frame *rxdata)
498 struct canfd_frame *cf = op->frames + op->cfsiz * index;
499 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
503 * no one uses the MSBs of flags for comparison,
504 * so we use it here to detect the first time of reception
507 if (!(lcf->flags & RX_RECV)) {
508 /* received data for the first time => send update to user */
509 bcm_rx_update_and_send(op, lcf, rxdata);
513 /* do a real check in CAN frame data section */
514 for (i = 0; i < rxdata->len; i += 8) {
515 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
516 (get_u64(cf, i) & get_u64(lcf, i))) {
517 bcm_rx_update_and_send(op, lcf, rxdata);
522 if (op->flags & RX_CHECK_DLC) {
523 /* do a real check in CAN frame length */
524 if (rxdata->len != lcf->len) {
525 bcm_rx_update_and_send(op, lcf, rxdata);
532 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
534 static void bcm_rx_starttimer(struct bcm_op *op)
536 if (op->flags & RX_NO_AUTOTIMER)
540 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
543 static void bcm_rx_timeout_tsklet(unsigned long data)
545 struct bcm_op *op = (struct bcm_op *)data;
546 struct bcm_msg_head msg_head;
548 /* create notification to user */
549 msg_head.opcode = RX_TIMEOUT;
550 msg_head.flags = op->flags;
551 msg_head.count = op->count;
552 msg_head.ival1 = op->ival1;
553 msg_head.ival2 = op->ival2;
554 msg_head.can_id = op->can_id;
555 msg_head.nframes = 0;
557 bcm_send_to_user(op, &msg_head, NULL, 0);
561 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
563 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
565 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
567 /* schedule before NET_RX_SOFTIRQ */
568 tasklet_hi_schedule(&op->tsklet);
570 /* no restart of the timer is done here! */
572 /* if user wants to be informed, when cyclic CAN-Messages come back */
573 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
574 /* clear received CAN frames to indicate 'nothing received' */
575 memset(op->last_frames, 0, op->nframes * op->cfsiz);
578 return HRTIMER_NORESTART;
582 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
584 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
587 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
589 if ((op->last_frames) && (lcf->flags & RX_THR)) {
591 bcm_rx_changed(op, lcf);
598 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
600 * update == 0 : just check if throttled data is available (any irq context)
601 * update == 1 : check and send throttled data to userspace (soft_irq context)
603 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
607 if (op->nframes > 1) {
610 /* for MUX filter we start at index 1 */
611 for (i = 1; i < op->nframes; i++)
612 updated += bcm_rx_do_flush(op, update, i);
615 /* for RX_FILTER_ID and simple filter */
616 updated += bcm_rx_do_flush(op, update, 0);
622 static void bcm_rx_thr_tsklet(unsigned long data)
624 struct bcm_op *op = (struct bcm_op *)data;
626 /* push the changed data to the userspace */
627 bcm_rx_thr_flush(op, 1);
631 * bcm_rx_thr_handler - the time for blocked content updates is over now:
632 * Check for throttled data and send it to the userspace
634 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
636 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
638 tasklet_schedule(&op->thrtsklet);
640 if (bcm_rx_thr_flush(op, 0)) {
641 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
642 return HRTIMER_RESTART;
644 /* rearm throttle handling */
646 return HRTIMER_NORESTART;
651 * bcm_rx_handler - handle a CAN frame reception
653 static void bcm_rx_handler(struct sk_buff *skb, void *data)
655 struct bcm_op *op = (struct bcm_op *)data;
656 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
659 if (op->can_id != rxframe->can_id)
662 /* make sure to handle the correct frame type (CAN / CAN FD) */
663 if (skb->len != op->cfsiz)
666 /* disable timeout */
667 hrtimer_cancel(&op->timer);
669 /* save rx timestamp */
670 op->rx_stamp = skb->tstamp;
671 /* save originator for recvfrom() */
672 op->rx_ifindex = skb->dev->ifindex;
673 /* update statistics */
676 if (op->flags & RX_RTR_FRAME) {
677 /* send reply for RTR-request (placed in op->frames[0]) */
682 if (op->flags & RX_FILTER_ID) {
683 /* the easiest case */
684 bcm_rx_update_and_send(op, op->last_frames, rxframe);
688 if (op->nframes == 1) {
689 /* simple compare with index 0 */
690 bcm_rx_cmp_to_index(op, 0, rxframe);
694 if (op->nframes > 1) {
698 * find the first multiplex mask that fits.
699 * Remark: The MUX-mask is stored in index 0 - but only the
700 * first 64 bits of the frame data[] are relevant (CAN FD)
703 for (i = 1; i < op->nframes; i++) {
704 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
705 (get_u64(op->frames, 0) &
706 get_u64(op->frames + op->cfsiz * i, 0))) {
707 bcm_rx_cmp_to_index(op, i, rxframe);
714 bcm_rx_starttimer(op);
718 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
720 static struct bcm_op *bcm_find_op(struct list_head *ops,
721 struct bcm_msg_head *mh, int ifindex)
725 list_for_each_entry(op, ops, list) {
726 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
727 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
734 static void bcm_remove_op(struct bcm_op *op)
736 if (op->tsklet.func) {
737 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
738 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
739 hrtimer_active(&op->timer)) {
740 hrtimer_cancel(&op->timer);
741 tasklet_kill(&op->tsklet);
745 if (op->thrtsklet.func) {
746 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
747 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
748 hrtimer_active(&op->thrtimer)) {
749 hrtimer_cancel(&op->thrtimer);
750 tasklet_kill(&op->thrtsklet);
754 if ((op->frames) && (op->frames != &op->sframe))
757 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
758 kfree(op->last_frames);
763 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
765 if (op->rx_reg_dev == dev) {
766 can_rx_unregister(dev_net(dev), dev, op->can_id,
767 REGMASK(op->can_id), bcm_rx_handler, op);
769 /* mark as removed subscription */
770 op->rx_reg_dev = NULL;
772 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
773 "mismatch %p %p\n", op->rx_reg_dev, dev);
777 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
779 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
782 struct bcm_op *op, *n;
784 list_for_each_entry_safe(op, n, ops, list) {
785 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
786 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
789 * Don't care if we're bound or not (due to netdev
790 * problems) can_rx_unregister() is always a save
795 * Only remove subscriptions that had not
796 * been removed due to NETDEV_UNREGISTER
799 if (op->rx_reg_dev) {
800 struct net_device *dev;
802 dev = dev_get_by_index(sock_net(op->sk),
805 bcm_rx_unreg(dev, op);
810 can_rx_unregister(sock_net(op->sk), NULL,
821 return 0; /* not found */
825 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
827 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
830 struct bcm_op *op, *n;
832 list_for_each_entry_safe(op, n, ops, list) {
833 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
834 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
841 return 0; /* not found */
845 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
847 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
850 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
855 /* put current values into msg_head */
856 msg_head->flags = op->flags;
857 msg_head->count = op->count;
858 msg_head->ival1 = op->ival1;
859 msg_head->ival2 = op->ival2;
860 msg_head->nframes = op->nframes;
862 bcm_send_to_user(op, msg_head, op->frames, 0);
868 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
870 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
871 int ifindex, struct sock *sk)
873 struct bcm_sock *bo = bcm_sk(sk);
875 struct canfd_frame *cf;
879 /* we need a real device to send frames */
883 /* check nframes boundaries - we need at least one CAN frame */
884 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
887 /* check the given can_id */
888 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
890 /* update existing BCM operation */
893 * Do we need more space for the CAN frames than currently
894 * allocated? -> This is a _really_ unusual use-case and
895 * therefore (complexity / locking) it is not supported.
897 if (msg_head->nframes > op->nframes)
900 /* update CAN frames content */
901 for (i = 0; i < msg_head->nframes; i++) {
903 cf = op->frames + op->cfsiz * i;
904 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
906 if (op->flags & CAN_FD_FRAME) {
917 if (msg_head->flags & TX_CP_CAN_ID) {
918 /* copy can_id into frame */
919 cf->can_id = msg_head->can_id;
922 op->flags = msg_head->flags;
925 /* insert new BCM operation for the given can_id */
927 op = kzalloc(OPSIZ, GFP_KERNEL);
931 op->can_id = msg_head->can_id;
932 op->cfsiz = CFSIZ(msg_head->flags);
933 op->flags = msg_head->flags;
935 /* create array for CAN frames and copy the data */
936 if (msg_head->nframes > 1) {
937 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
944 op->frames = &op->sframe;
946 for (i = 0; i < msg_head->nframes; i++) {
948 cf = op->frames + op->cfsiz * i;
949 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
951 if (op->flags & CAN_FD_FRAME) {
960 if (op->frames != &op->sframe)
966 if (msg_head->flags & TX_CP_CAN_ID) {
967 /* copy can_id into frame */
968 cf->can_id = msg_head->can_id;
972 /* tx_ops never compare with previous received messages */
973 op->last_frames = NULL;
975 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
977 op->ifindex = ifindex;
979 /* initialize uninitialized (kzalloc) structure */
980 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
981 op->timer.function = bcm_tx_timeout_handler;
983 /* initialize tasklet for tx countevent notification */
984 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
987 /* currently unused in tx_ops */
988 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
990 /* add this bcm_op to the list of the tx_ops */
991 list_add(&op->list, &bo->tx_ops);
993 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
995 if (op->nframes != msg_head->nframes) {
996 op->nframes = msg_head->nframes;
997 /* start multiple frame transmission with index 0 */
1003 if (op->flags & TX_RESET_MULTI_IDX) {
1004 /* start multiple frame transmission with index 0 */
1008 if (op->flags & SETTIMER) {
1009 /* set timer values */
1010 op->count = msg_head->count;
1011 op->ival1 = msg_head->ival1;
1012 op->ival2 = msg_head->ival2;
1013 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1014 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1016 /* disable an active timer due to zero values? */
1017 if (!op->kt_ival1 && !op->kt_ival2)
1018 hrtimer_cancel(&op->timer);
1021 if (op->flags & STARTTIMER) {
1022 hrtimer_cancel(&op->timer);
1023 /* spec: send CAN frame when starting timer */
1024 op->flags |= TX_ANNOUNCE;
1027 if (op->flags & TX_ANNOUNCE) {
1033 if (op->flags & STARTTIMER)
1034 bcm_tx_start_timer(op);
1036 return msg_head->nframes * op->cfsiz + MHSIZ;
1040 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1042 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1043 int ifindex, struct sock *sk)
1045 struct bcm_sock *bo = bcm_sk(sk);
1050 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1051 /* be robust against wrong usage ... */
1052 msg_head->flags |= RX_FILTER_ID;
1053 /* ignore trailing garbage */
1054 msg_head->nframes = 0;
1057 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1058 if (msg_head->nframes > MAX_NFRAMES + 1)
1061 if ((msg_head->flags & RX_RTR_FRAME) &&
1062 ((msg_head->nframes != 1) ||
1063 (!(msg_head->can_id & CAN_RTR_FLAG))))
1066 /* check the given can_id */
1067 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1069 /* update existing BCM operation */
1072 * Do we need more space for the CAN frames than currently
1073 * allocated? -> This is a _really_ unusual use-case and
1074 * therefore (complexity / locking) it is not supported.
1076 if (msg_head->nframes > op->nframes)
1079 if (msg_head->nframes) {
1080 /* update CAN frames content */
1081 err = memcpy_from_msg(op->frames, msg,
1082 msg_head->nframes * op->cfsiz);
1086 /* clear last_frames to indicate 'nothing received' */
1087 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1090 op->nframes = msg_head->nframes;
1091 op->flags = msg_head->flags;
1093 /* Only an update -> do not call can_rx_register() */
1097 /* insert new BCM operation for the given can_id */
1098 op = kzalloc(OPSIZ, GFP_KERNEL);
1102 op->can_id = msg_head->can_id;
1103 op->nframes = msg_head->nframes;
1104 op->cfsiz = CFSIZ(msg_head->flags);
1105 op->flags = msg_head->flags;
1107 if (msg_head->nframes > 1) {
1108 /* create array for CAN frames and copy the data */
1109 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1116 /* create and init array for received CAN frames */
1117 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1119 if (!op->last_frames) {
1126 op->frames = &op->sframe;
1127 op->last_frames = &op->last_sframe;
1130 if (msg_head->nframes) {
1131 err = memcpy_from_msg(op->frames, msg,
1132 msg_head->nframes * op->cfsiz);
1134 if (op->frames != &op->sframe)
1136 if (op->last_frames != &op->last_sframe)
1137 kfree(op->last_frames);
1143 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1145 op->ifindex = ifindex;
1147 /* ifindex for timeout events w/o previous frame reception */
1148 op->rx_ifindex = ifindex;
1150 /* initialize uninitialized (kzalloc) structure */
1151 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1152 op->timer.function = bcm_rx_timeout_handler;
1154 /* initialize tasklet for rx timeout notification */
1155 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1156 (unsigned long) op);
1158 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1159 op->thrtimer.function = bcm_rx_thr_handler;
1161 /* initialize tasklet for rx throttle handling */
1162 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1163 (unsigned long) op);
1165 /* add this bcm_op to the list of the rx_ops */
1166 list_add(&op->list, &bo->rx_ops);
1168 /* call can_rx_register() */
1171 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1175 if (op->flags & RX_RTR_FRAME) {
1176 struct canfd_frame *frame0 = op->frames;
1178 /* no timers in RTR-mode */
1179 hrtimer_cancel(&op->thrtimer);
1180 hrtimer_cancel(&op->timer);
1183 * funny feature in RX(!)_SETUP only for RTR-mode:
1184 * copy can_id into frame BUT without RTR-flag to
1185 * prevent a full-load-loopback-test ... ;-]
1187 if ((op->flags & TX_CP_CAN_ID) ||
1188 (frame0->can_id == op->can_id))
1189 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1192 if (op->flags & SETTIMER) {
1194 /* set timer value */
1195 op->ival1 = msg_head->ival1;
1196 op->ival2 = msg_head->ival2;
1197 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1198 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1200 /* disable an active timer due to zero value? */
1202 hrtimer_cancel(&op->timer);
1205 * In any case cancel the throttle timer, flush
1206 * potentially blocked msgs and reset throttle handling
1209 hrtimer_cancel(&op->thrtimer);
1210 bcm_rx_thr_flush(op, 1);
1213 if ((op->flags & STARTTIMER) && op->kt_ival1)
1214 hrtimer_start(&op->timer, op->kt_ival1,
1218 /* now we can register for can_ids, if we added a new bcm_op */
1219 if (do_rx_register) {
1221 struct net_device *dev;
1223 dev = dev_get_by_index(sock_net(sk), ifindex);
1225 err = can_rx_register(sock_net(sk), dev,
1227 REGMASK(op->can_id),
1231 op->rx_reg_dev = dev;
1236 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1237 REGMASK(op->can_id),
1238 bcm_rx_handler, op, "bcm", sk);
1240 /* this bcm rx op is broken -> remove it */
1241 list_del(&op->list);
1247 return msg_head->nframes * op->cfsiz + MHSIZ;
1251 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1253 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1256 struct sk_buff *skb;
1257 struct net_device *dev;
1260 /* we need a real device to send frames */
1264 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1268 can_skb_reserve(skb);
1270 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1276 dev = dev_get_by_index(sock_net(sk), ifindex);
1282 can_skb_prv(skb)->ifindex = dev->ifindex;
1283 can_skb_prv(skb)->skbcnt = 0;
1285 can_skb_set_owner(skb, sk);
1286 err = can_send(skb, 1); /* send with loopback */
1292 return cfsiz + MHSIZ;
1296 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1298 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1300 struct sock *sk = sock->sk;
1301 struct bcm_sock *bo = bcm_sk(sk);
1302 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1303 struct bcm_msg_head msg_head;
1305 int ret; /* read bytes or error codes as return value */
1310 /* check for valid message length from userspace */
1314 /* read message head information */
1315 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1319 cfsiz = CFSIZ(msg_head.flags);
1320 if ((size - MHSIZ) % cfsiz)
1323 /* check for alternative ifindex for this bcm_op */
1325 if (!ifindex && msg->msg_name) {
1326 /* no bound device as default => check msg_name */
1327 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1329 if (msg->msg_namelen < sizeof(*addr))
1332 if (addr->can_family != AF_CAN)
1335 /* ifindex from sendto() */
1336 ifindex = addr->can_ifindex;
1339 struct net_device *dev;
1341 dev = dev_get_by_index(sock_net(sk), ifindex);
1345 if (dev->type != ARPHRD_CAN) {
1356 switch (msg_head.opcode) {
1359 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1363 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1367 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1374 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1381 /* reuse msg_head for the reply to TX_READ */
1382 msg_head.opcode = TX_STATUS;
1383 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1387 /* reuse msg_head for the reply to RX_READ */
1388 msg_head.opcode = RX_STATUS;
1389 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1393 /* we need exactly one CAN frame behind the msg head */
1394 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1397 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1411 * notification handler for netdevice status changes
1413 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1416 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1417 struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1418 struct sock *sk = &bo->sk;
1420 int notify_enodev = 0;
1422 if (!net_eq(dev_net(dev), sock_net(sk)))
1425 if (dev->type != ARPHRD_CAN)
1430 case NETDEV_UNREGISTER:
1433 /* remove device specific receive entries */
1434 list_for_each_entry(op, &bo->rx_ops, list)
1435 if (op->rx_reg_dev == dev)
1436 bcm_rx_unreg(dev, op);
1438 /* remove device reference, if this is our bound device */
1439 if (bo->bound && bo->ifindex == dev->ifindex) {
1447 if (notify_enodev) {
1448 sk->sk_err = ENODEV;
1449 if (!sock_flag(sk, SOCK_DEAD))
1450 sk->sk_error_report(sk);
1455 if (bo->bound && bo->ifindex == dev->ifindex) {
1456 sk->sk_err = ENETDOWN;
1457 if (!sock_flag(sk, SOCK_DEAD))
1458 sk->sk_error_report(sk);
1466 * initial settings for all BCM sockets to be set at socket creation time
1468 static int bcm_init(struct sock *sk)
1470 struct bcm_sock *bo = bcm_sk(sk);
1474 bo->dropped_usr_msgs = 0;
1475 bo->bcm_proc_read = NULL;
1477 INIT_LIST_HEAD(&bo->tx_ops);
1478 INIT_LIST_HEAD(&bo->rx_ops);
1481 bo->notifier.notifier_call = bcm_notifier;
1483 register_netdevice_notifier(&bo->notifier);
1489 * standard socket functions
1491 static int bcm_release(struct socket *sock)
1493 struct sock *sk = sock->sk;
1494 struct net *net = sock_net(sk);
1495 struct bcm_sock *bo;
1496 struct bcm_op *op, *next;
1503 /* remove bcm_ops, timer, rx_unregister(), etc. */
1505 unregister_netdevice_notifier(&bo->notifier);
1509 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1512 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1514 * Don't care if we're bound or not (due to netdev problems)
1515 * can_rx_unregister() is always a save thing to do here.
1519 * Only remove subscriptions that had not
1520 * been removed due to NETDEV_UNREGISTER
1523 if (op->rx_reg_dev) {
1524 struct net_device *dev;
1526 dev = dev_get_by_index(net, op->ifindex);
1528 bcm_rx_unreg(dev, op);
1533 can_rx_unregister(net, NULL, op->can_id,
1534 REGMASK(op->can_id),
1535 bcm_rx_handler, op);
1540 /* remove procfs entry */
1541 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1542 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1544 /* remove device reference */
1559 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1562 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1563 struct sock *sk = sock->sk;
1564 struct bcm_sock *bo = bcm_sk(sk);
1565 struct net *net = sock_net(sk);
1568 if (len < sizeof(*addr))
1578 /* bind a device to this socket */
1579 if (addr->can_ifindex) {
1580 struct net_device *dev;
1582 dev = dev_get_by_index(net, addr->can_ifindex);
1587 if (dev->type != ARPHRD_CAN) {
1593 bo->ifindex = dev->ifindex;
1597 /* no interface reference for ifindex = 0 ('any' CAN device) */
1601 if (net->can.bcmproc_dir) {
1602 /* unique socket address as filename */
1603 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1604 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1605 net->can.bcmproc_dir,
1606 &bcm_proc_fops, sk);
1607 if (!bo->bcm_proc_read) {
1621 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1624 struct sock *sk = sock->sk;
1625 struct sk_buff *skb;
1630 noblock = flags & MSG_DONTWAIT;
1631 flags &= ~MSG_DONTWAIT;
1632 skb = skb_recv_datagram(sk, flags, noblock, &error);
1636 if (skb->len < size)
1639 err = memcpy_to_msg(msg, skb->data, size);
1641 skb_free_datagram(sk, skb);
1645 sock_recv_ts_and_drops(msg, sk, skb);
1647 if (msg->msg_name) {
1648 __sockaddr_check_size(sizeof(struct sockaddr_can));
1649 msg->msg_namelen = sizeof(struct sockaddr_can);
1650 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1653 skb_free_datagram(sk, skb);
1658 static const struct proto_ops bcm_ops = {
1660 .release = bcm_release,
1661 .bind = sock_no_bind,
1662 .connect = bcm_connect,
1663 .socketpair = sock_no_socketpair,
1664 .accept = sock_no_accept,
1665 .getname = sock_no_getname,
1666 .poll = datagram_poll,
1667 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1668 .listen = sock_no_listen,
1669 .shutdown = sock_no_shutdown,
1670 .setsockopt = sock_no_setsockopt,
1671 .getsockopt = sock_no_getsockopt,
1672 .sendmsg = bcm_sendmsg,
1673 .recvmsg = bcm_recvmsg,
1674 .mmap = sock_no_mmap,
1675 .sendpage = sock_no_sendpage,
1678 static struct proto bcm_proto __read_mostly = {
1680 .owner = THIS_MODULE,
1681 .obj_size = sizeof(struct bcm_sock),
1685 static const struct can_proto bcm_can_proto = {
1687 .protocol = CAN_BCM,
1692 static int canbcm_pernet_init(struct net *net)
1694 /* create /proc/net/can-bcm directory */
1695 if (IS_ENABLED(CONFIG_PROC_FS)) {
1696 net->can.bcmproc_dir =
1697 proc_net_mkdir(net, "can-bcm", net->proc_net);
1703 static void canbcm_pernet_exit(struct net *net)
1705 /* remove /proc/net/can-bcm directory */
1706 if (IS_ENABLED(CONFIG_PROC_FS)) {
1707 if (net->can.bcmproc_dir)
1708 remove_proc_entry("can-bcm", net->proc_net);
1712 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1713 .init = canbcm_pernet_init,
1714 .exit = canbcm_pernet_exit,
1717 static int __init bcm_module_init(void)
1721 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1723 err = can_proto_register(&bcm_can_proto);
1725 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1729 register_pernet_subsys(&canbcm_pernet_ops);
1733 static void __exit bcm_module_exit(void)
1735 can_proto_unregister(&bcm_can_proto);
1736 unregister_pernet_subsys(&canbcm_pernet_ops);
1739 module_init(bcm_module_init);
1740 module_exit(bcm_module_exit);