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
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
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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.
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].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 "20170425"
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;
128 struct list_head notifier;
129 struct list_head rx_ops;
130 struct list_head tx_ops;
131 unsigned long dropped_usr_msgs;
132 struct proc_dir_entry *bcm_proc_read;
133 char procname [32]; /* inode number in decimal with \0 */
136 static LIST_HEAD(bcm_notifier_list);
137 static DEFINE_SPINLOCK(bcm_notifier_lock);
138 static struct bcm_sock *bcm_busy_notifier;
140 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
142 return (struct bcm_sock *)sk;
145 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
147 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
150 /* check limitations for timeval provided by user */
151 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
153 if ((msg_head->ival1.tv_sec < 0) ||
154 (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
155 (msg_head->ival1.tv_usec < 0) ||
156 (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
157 (msg_head->ival2.tv_sec < 0) ||
158 (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
159 (msg_head->ival2.tv_usec < 0) ||
160 (msg_head->ival2.tv_usec >= USEC_PER_SEC))
166 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
167 #define OPSIZ sizeof(struct bcm_op)
168 #define MHSIZ sizeof(struct bcm_msg_head)
173 #if IS_ENABLED(CONFIG_PROC_FS)
174 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
176 struct net_device *dev;
182 dev = dev_get_by_index_rcu(net, ifindex);
184 strcpy(result, dev->name);
186 strcpy(result, "???");
192 static int bcm_proc_show(struct seq_file *m, void *v)
194 char ifname[IFNAMSIZ];
195 struct net *net = m->private;
196 struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
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(net, 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(net, 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' : ' ');
226 seq_printf(m, "timeo=%lld ",
227 (long long)ktime_to_us(op->kt_ival1));
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(net, ifname, op->ifindex));
247 if (op->flags & CAN_FD_FRAME)
248 seq_printf(m, "(%u) ", op->nframes);
250 seq_printf(m, "[%u] ", op->nframes);
253 seq_printf(m, "t1=%lld ",
254 (long long)ktime_to_us(op->kt_ival1));
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);
265 #endif /* CONFIG_PROC_FS */
268 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
269 * of the given bcm tx op
271 static void bcm_can_tx(struct bcm_op *op)
274 struct net_device *dev;
275 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
277 /* no target device? => exit */
281 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
283 /* RFC: should this bcm_op remove itself here? */
287 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
291 can_skb_reserve(skb);
292 can_skb_prv(skb)->ifindex = dev->ifindex;
293 can_skb_prv(skb)->skbcnt = 0;
295 skb_put_data(skb, cf, op->cfsiz);
297 /* send with loopback */
299 can_skb_set_owner(skb, op->sk);
302 /* update statistics */
306 /* reached last frame? */
307 if (op->currframe >= op->nframes)
314 * bcm_send_to_user - send a BCM message to the userspace
315 * (consisting of bcm_msg_head + x CAN frames)
317 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
318 struct canfd_frame *frames, int has_timestamp)
321 struct canfd_frame *firstframe;
322 struct sockaddr_can *addr;
323 struct sock *sk = op->sk;
324 unsigned int datalen = head->nframes * op->cfsiz;
327 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
331 skb_put_data(skb, head, sizeof(*head));
334 /* CAN frames starting here */
335 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
337 skb_put_data(skb, frames, datalen);
340 * the BCM uses the flags-element of the canfd_frame
341 * structure for internal purposes. This is only
342 * relevant for updates that are generated by the
343 * BCM, where nframes is 1
345 if (head->nframes == 1)
346 firstframe->flags &= BCM_CAN_FLAGS_MASK;
350 /* restore rx timestamp */
351 skb->tstamp = op->rx_stamp;
355 * Put the datagram to the queue so that bcm_recvmsg() can
356 * get it from there. We need to pass the interface index to
357 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
358 * containing the interface index.
361 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
362 addr = (struct sockaddr_can *)skb->cb;
363 memset(addr, 0, sizeof(*addr));
364 addr->can_family = AF_CAN;
365 addr->can_ifindex = op->rx_ifindex;
367 err = sock_queue_rcv_skb(sk, skb);
369 struct bcm_sock *bo = bcm_sk(sk);
372 /* don't care about overflows in this statistic */
373 bo->dropped_usr_msgs++;
377 static void bcm_tx_start_timer(struct bcm_op *op)
379 if (op->kt_ival1 && op->count)
380 hrtimer_start(&op->timer,
381 ktime_add(ktime_get(), op->kt_ival1),
383 else if (op->kt_ival2)
384 hrtimer_start(&op->timer,
385 ktime_add(ktime_get(), op->kt_ival2),
389 static void bcm_tx_timeout_tsklet(unsigned long data)
391 struct bcm_op *op = (struct bcm_op *)data;
392 struct bcm_msg_head msg_head;
394 if (op->kt_ival1 && (op->count > 0)) {
397 if (!op->count && (op->flags & TX_COUNTEVT)) {
399 /* create notification to user */
400 memset(&msg_head, 0, sizeof(msg_head));
401 msg_head.opcode = TX_EXPIRED;
402 msg_head.flags = op->flags;
403 msg_head.count = op->count;
404 msg_head.ival1 = op->ival1;
405 msg_head.ival2 = op->ival2;
406 msg_head.can_id = op->can_id;
407 msg_head.nframes = 0;
409 bcm_send_to_user(op, &msg_head, NULL, 0);
413 } else if (op->kt_ival2)
416 bcm_tx_start_timer(op);
420 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
422 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
424 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
426 tasklet_schedule(&op->tsklet);
428 return HRTIMER_NORESTART;
432 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
434 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
436 struct bcm_msg_head head;
438 /* update statistics */
439 op->frames_filtered++;
441 /* prevent statistics overflow */
442 if (op->frames_filtered > ULONG_MAX/100)
443 op->frames_filtered = op->frames_abs = 0;
445 /* this element is not throttled anymore */
446 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
448 memset(&head, 0, sizeof(head));
449 head.opcode = RX_CHANGED;
450 head.flags = op->flags;
451 head.count = op->count;
452 head.ival1 = op->ival1;
453 head.ival2 = op->ival2;
454 head.can_id = op->can_id;
457 bcm_send_to_user(op, &head, data, 1);
461 * bcm_rx_update_and_send - process a detected relevant receive content change
462 * 1. update the last received data
463 * 2. send a notification to the user (if possible)
465 static void bcm_rx_update_and_send(struct bcm_op *op,
466 struct canfd_frame *lastdata,
467 const struct canfd_frame *rxdata)
469 memcpy(lastdata, rxdata, op->cfsiz);
471 /* mark as used and throttled by default */
472 lastdata->flags |= (RX_RECV|RX_THR);
474 /* throttling mode inactive ? */
476 /* send RX_CHANGED to the user immediately */
477 bcm_rx_changed(op, lastdata);
481 /* with active throttling timer we are just done here */
482 if (hrtimer_active(&op->thrtimer))
485 /* first reception with enabled throttling mode */
487 goto rx_changed_settime;
489 /* got a second frame inside a potential throttle period? */
490 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
491 ktime_to_us(op->kt_ival2)) {
492 /* do not send the saved data - only start throttle timer */
493 hrtimer_start(&op->thrtimer,
494 ktime_add(op->kt_lastmsg, op->kt_ival2),
499 /* the gap was that big, that throttling was not needed here */
501 bcm_rx_changed(op, lastdata);
502 op->kt_lastmsg = ktime_get();
506 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
507 * received data stored in op->last_frames[]
509 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
510 const struct canfd_frame *rxdata)
512 struct canfd_frame *cf = op->frames + op->cfsiz * index;
513 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
517 * no one uses the MSBs of flags for comparison,
518 * so we use it here to detect the first time of reception
521 if (!(lcf->flags & RX_RECV)) {
522 /* received data for the first time => send update to user */
523 bcm_rx_update_and_send(op, lcf, rxdata);
527 /* do a real check in CAN frame data section */
528 for (i = 0; i < rxdata->len; i += 8) {
529 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
530 (get_u64(cf, i) & get_u64(lcf, i))) {
531 bcm_rx_update_and_send(op, lcf, rxdata);
536 if (op->flags & RX_CHECK_DLC) {
537 /* do a real check in CAN frame length */
538 if (rxdata->len != lcf->len) {
539 bcm_rx_update_and_send(op, lcf, rxdata);
546 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
548 static void bcm_rx_starttimer(struct bcm_op *op)
550 if (op->flags & RX_NO_AUTOTIMER)
554 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
557 static void bcm_rx_timeout_tsklet(unsigned long data)
559 struct bcm_op *op = (struct bcm_op *)data;
560 struct bcm_msg_head msg_head;
562 /* create notification to user */
563 memset(&msg_head, 0, sizeof(msg_head));
564 msg_head.opcode = RX_TIMEOUT;
565 msg_head.flags = op->flags;
566 msg_head.count = op->count;
567 msg_head.ival1 = op->ival1;
568 msg_head.ival2 = op->ival2;
569 msg_head.can_id = op->can_id;
570 msg_head.nframes = 0;
572 bcm_send_to_user(op, &msg_head, NULL, 0);
576 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
578 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
580 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
582 /* schedule before NET_RX_SOFTIRQ */
583 tasklet_hi_schedule(&op->tsklet);
585 /* no restart of the timer is done here! */
587 /* if user wants to be informed, when cyclic CAN-Messages come back */
588 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
589 /* clear received CAN frames to indicate 'nothing received' */
590 memset(op->last_frames, 0, op->nframes * op->cfsiz);
593 return HRTIMER_NORESTART;
597 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
599 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
602 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
604 if ((op->last_frames) && (lcf->flags & RX_THR)) {
606 bcm_rx_changed(op, lcf);
613 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
615 * update == 0 : just check if throttled data is available (any irq context)
616 * update == 1 : check and send throttled data to userspace (soft_irq context)
618 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
622 if (op->nframes > 1) {
625 /* for MUX filter we start at index 1 */
626 for (i = 1; i < op->nframes; i++)
627 updated += bcm_rx_do_flush(op, update, i);
630 /* for RX_FILTER_ID and simple filter */
631 updated += bcm_rx_do_flush(op, update, 0);
637 static void bcm_rx_thr_tsklet(unsigned long data)
639 struct bcm_op *op = (struct bcm_op *)data;
641 /* push the changed data to the userspace */
642 bcm_rx_thr_flush(op, 1);
646 * bcm_rx_thr_handler - the time for blocked content updates is over now:
647 * Check for throttled data and send it to the userspace
649 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
651 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
653 tasklet_schedule(&op->thrtsklet);
655 if (bcm_rx_thr_flush(op, 0)) {
656 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
657 return HRTIMER_RESTART;
659 /* rearm throttle handling */
661 return HRTIMER_NORESTART;
666 * bcm_rx_handler - handle a CAN frame reception
668 static void bcm_rx_handler(struct sk_buff *skb, void *data)
670 struct bcm_op *op = (struct bcm_op *)data;
671 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
674 if (op->can_id != rxframe->can_id)
677 /* make sure to handle the correct frame type (CAN / CAN FD) */
678 if (skb->len != op->cfsiz)
681 /* disable timeout */
682 hrtimer_cancel(&op->timer);
684 /* save rx timestamp */
685 op->rx_stamp = skb->tstamp;
686 /* save originator for recvfrom() */
687 op->rx_ifindex = skb->dev->ifindex;
688 /* update statistics */
691 if (op->flags & RX_RTR_FRAME) {
692 /* send reply for RTR-request (placed in op->frames[0]) */
697 if (op->flags & RX_FILTER_ID) {
698 /* the easiest case */
699 bcm_rx_update_and_send(op, op->last_frames, rxframe);
703 if (op->nframes == 1) {
704 /* simple compare with index 0 */
705 bcm_rx_cmp_to_index(op, 0, rxframe);
709 if (op->nframes > 1) {
713 * find the first multiplex mask that fits.
714 * Remark: The MUX-mask is stored in index 0 - but only the
715 * first 64 bits of the frame data[] are relevant (CAN FD)
718 for (i = 1; i < op->nframes; i++) {
719 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
720 (get_u64(op->frames, 0) &
721 get_u64(op->frames + op->cfsiz * i, 0))) {
722 bcm_rx_cmp_to_index(op, i, rxframe);
729 bcm_rx_starttimer(op);
733 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
735 static struct bcm_op *bcm_find_op(struct list_head *ops,
736 struct bcm_msg_head *mh, int ifindex)
740 list_for_each_entry(op, ops, list) {
741 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
742 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
749 static void bcm_remove_op(struct bcm_op *op)
751 if (op->tsklet.func) {
752 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
753 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
754 hrtimer_active(&op->timer)) {
755 hrtimer_cancel(&op->timer);
756 tasklet_kill(&op->tsklet);
760 if (op->thrtsklet.func) {
761 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
762 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
763 hrtimer_active(&op->thrtimer)) {
764 hrtimer_cancel(&op->thrtimer);
765 tasklet_kill(&op->thrtsklet);
769 if ((op->frames) && (op->frames != &op->sframe))
772 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
773 kfree(op->last_frames);
778 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
780 if (op->rx_reg_dev == dev) {
781 can_rx_unregister(dev_net(dev), dev, op->can_id,
782 REGMASK(op->can_id), bcm_rx_handler, op);
784 /* mark as removed subscription */
785 op->rx_reg_dev = NULL;
787 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
788 "mismatch %p %p\n", op->rx_reg_dev, dev);
792 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
794 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
797 struct bcm_op *op, *n;
799 list_for_each_entry_safe(op, n, ops, list) {
800 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
801 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
804 * Don't care if we're bound or not (due to netdev
805 * problems) can_rx_unregister() is always a save
810 * Only remove subscriptions that had not
811 * been removed due to NETDEV_UNREGISTER
814 if (op->rx_reg_dev) {
815 struct net_device *dev;
817 dev = dev_get_by_index(sock_net(op->sk),
820 bcm_rx_unreg(dev, op);
825 can_rx_unregister(sock_net(op->sk), NULL,
837 return 0; /* not found */
841 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
843 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
846 struct bcm_op *op, *n;
848 list_for_each_entry_safe(op, n, ops, list) {
849 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
850 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
857 return 0; /* not found */
861 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
863 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
866 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
871 /* put current values into msg_head */
872 msg_head->flags = op->flags;
873 msg_head->count = op->count;
874 msg_head->ival1 = op->ival1;
875 msg_head->ival2 = op->ival2;
876 msg_head->nframes = op->nframes;
878 bcm_send_to_user(op, msg_head, op->frames, 0);
884 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
886 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
887 int ifindex, struct sock *sk)
889 struct bcm_sock *bo = bcm_sk(sk);
891 struct canfd_frame *cf;
895 /* we need a real device to send frames */
899 /* check nframes boundaries - we need at least one CAN frame */
900 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
903 /* check timeval limitations */
904 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
907 /* check the given can_id */
908 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
910 /* update existing BCM operation */
913 * Do we need more space for the CAN frames than currently
914 * allocated? -> This is a _really_ unusual use-case and
915 * therefore (complexity / locking) it is not supported.
917 if (msg_head->nframes > op->nframes)
920 /* update CAN frames content */
921 for (i = 0; i < msg_head->nframes; i++) {
923 cf = op->frames + op->cfsiz * i;
924 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
926 if (op->flags & CAN_FD_FRAME) {
937 if (msg_head->flags & TX_CP_CAN_ID) {
938 /* copy can_id into frame */
939 cf->can_id = msg_head->can_id;
942 op->flags = msg_head->flags;
945 /* insert new BCM operation for the given can_id */
947 op = kzalloc(OPSIZ, GFP_KERNEL);
951 op->can_id = msg_head->can_id;
952 op->cfsiz = CFSIZ(msg_head->flags);
953 op->flags = msg_head->flags;
955 /* create array for CAN frames and copy the data */
956 if (msg_head->nframes > 1) {
957 op->frames = kmalloc_array(msg_head->nframes,
965 op->frames = &op->sframe;
967 for (i = 0; i < msg_head->nframes; i++) {
969 cf = op->frames + op->cfsiz * i;
970 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
972 if (op->flags & CAN_FD_FRAME) {
981 if (op->frames != &op->sframe)
987 if (msg_head->flags & TX_CP_CAN_ID) {
988 /* copy can_id into frame */
989 cf->can_id = msg_head->can_id;
993 /* tx_ops never compare with previous received messages */
994 op->last_frames = NULL;
996 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
998 op->ifindex = ifindex;
1000 /* initialize uninitialized (kzalloc) structure */
1001 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1002 op->timer.function = bcm_tx_timeout_handler;
1004 /* initialize tasklet for tx countevent notification */
1005 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
1006 (unsigned long) op);
1008 /* currently unused in tx_ops */
1009 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1011 /* add this bcm_op to the list of the tx_ops */
1012 list_add(&op->list, &bo->tx_ops);
1014 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
1016 if (op->nframes != msg_head->nframes) {
1017 op->nframes = msg_head->nframes;
1018 /* start multiple frame transmission with index 0 */
1024 if (op->flags & TX_RESET_MULTI_IDX) {
1025 /* start multiple frame transmission with index 0 */
1029 if (op->flags & SETTIMER) {
1030 /* set timer values */
1031 op->count = msg_head->count;
1032 op->ival1 = msg_head->ival1;
1033 op->ival2 = msg_head->ival2;
1034 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1035 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1037 /* disable an active timer due to zero values? */
1038 if (!op->kt_ival1 && !op->kt_ival2)
1039 hrtimer_cancel(&op->timer);
1042 if (op->flags & STARTTIMER) {
1043 hrtimer_cancel(&op->timer);
1044 /* spec: send CAN frame when starting timer */
1045 op->flags |= TX_ANNOUNCE;
1048 if (op->flags & TX_ANNOUNCE) {
1054 if (op->flags & STARTTIMER)
1055 bcm_tx_start_timer(op);
1057 return msg_head->nframes * op->cfsiz + MHSIZ;
1061 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1063 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1064 int ifindex, struct sock *sk)
1066 struct bcm_sock *bo = bcm_sk(sk);
1071 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1072 /* be robust against wrong usage ... */
1073 msg_head->flags |= RX_FILTER_ID;
1074 /* ignore trailing garbage */
1075 msg_head->nframes = 0;
1078 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1079 if (msg_head->nframes > MAX_NFRAMES + 1)
1082 if ((msg_head->flags & RX_RTR_FRAME) &&
1083 ((msg_head->nframes != 1) ||
1084 (!(msg_head->can_id & CAN_RTR_FLAG))))
1087 /* check timeval limitations */
1088 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1091 /* check the given can_id */
1092 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1094 /* update existing BCM operation */
1097 * Do we need more space for the CAN frames than currently
1098 * allocated? -> This is a _really_ unusual use-case and
1099 * therefore (complexity / locking) it is not supported.
1101 if (msg_head->nframes > op->nframes)
1104 if (msg_head->nframes) {
1105 /* update CAN frames content */
1106 err = memcpy_from_msg(op->frames, msg,
1107 msg_head->nframes * op->cfsiz);
1111 /* clear last_frames to indicate 'nothing received' */
1112 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1115 op->nframes = msg_head->nframes;
1116 op->flags = msg_head->flags;
1118 /* Only an update -> do not call can_rx_register() */
1122 /* insert new BCM operation for the given can_id */
1123 op = kzalloc(OPSIZ, GFP_KERNEL);
1127 op->can_id = msg_head->can_id;
1128 op->nframes = msg_head->nframes;
1129 op->cfsiz = CFSIZ(msg_head->flags);
1130 op->flags = msg_head->flags;
1132 if (msg_head->nframes > 1) {
1133 /* create array for CAN frames and copy the data */
1134 op->frames = kmalloc_array(msg_head->nframes,
1142 /* create and init array for received CAN frames */
1143 op->last_frames = kcalloc(msg_head->nframes,
1146 if (!op->last_frames) {
1153 op->frames = &op->sframe;
1154 op->last_frames = &op->last_sframe;
1157 if (msg_head->nframes) {
1158 err = memcpy_from_msg(op->frames, msg,
1159 msg_head->nframes * op->cfsiz);
1161 if (op->frames != &op->sframe)
1163 if (op->last_frames != &op->last_sframe)
1164 kfree(op->last_frames);
1170 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1172 op->ifindex = ifindex;
1174 /* ifindex for timeout events w/o previous frame reception */
1175 op->rx_ifindex = ifindex;
1177 /* initialize uninitialized (kzalloc) structure */
1178 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1179 op->timer.function = bcm_rx_timeout_handler;
1181 /* initialize tasklet for rx timeout notification */
1182 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1183 (unsigned long) op);
1185 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1186 op->thrtimer.function = bcm_rx_thr_handler;
1188 /* initialize tasklet for rx throttle handling */
1189 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1190 (unsigned long) op);
1192 /* add this bcm_op to the list of the rx_ops */
1193 list_add(&op->list, &bo->rx_ops);
1195 /* call can_rx_register() */
1198 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1202 if (op->flags & RX_RTR_FRAME) {
1203 struct canfd_frame *frame0 = op->frames;
1205 /* no timers in RTR-mode */
1206 hrtimer_cancel(&op->thrtimer);
1207 hrtimer_cancel(&op->timer);
1210 * funny feature in RX(!)_SETUP only for RTR-mode:
1211 * copy can_id into frame BUT without RTR-flag to
1212 * prevent a full-load-loopback-test ... ;-]
1214 if ((op->flags & TX_CP_CAN_ID) ||
1215 (frame0->can_id == op->can_id))
1216 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1219 if (op->flags & SETTIMER) {
1221 /* set timer value */
1222 op->ival1 = msg_head->ival1;
1223 op->ival2 = msg_head->ival2;
1224 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1225 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1227 /* disable an active timer due to zero value? */
1229 hrtimer_cancel(&op->timer);
1232 * In any case cancel the throttle timer, flush
1233 * potentially blocked msgs and reset throttle handling
1236 hrtimer_cancel(&op->thrtimer);
1237 bcm_rx_thr_flush(op, 1);
1240 if ((op->flags & STARTTIMER) && op->kt_ival1)
1241 hrtimer_start(&op->timer, op->kt_ival1,
1245 /* now we can register for can_ids, if we added a new bcm_op */
1246 if (do_rx_register) {
1248 struct net_device *dev;
1250 dev = dev_get_by_index(sock_net(sk), ifindex);
1252 err = can_rx_register(sock_net(sk), dev,
1254 REGMASK(op->can_id),
1258 op->rx_reg_dev = dev;
1263 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1264 REGMASK(op->can_id),
1265 bcm_rx_handler, op, "bcm", sk);
1267 /* this bcm rx op is broken -> remove it */
1268 list_del(&op->list);
1274 return msg_head->nframes * op->cfsiz + MHSIZ;
1278 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1280 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1283 struct sk_buff *skb;
1284 struct net_device *dev;
1287 /* we need a real device to send frames */
1291 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1295 can_skb_reserve(skb);
1297 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1303 dev = dev_get_by_index(sock_net(sk), ifindex);
1309 can_skb_prv(skb)->ifindex = dev->ifindex;
1310 can_skb_prv(skb)->skbcnt = 0;
1312 can_skb_set_owner(skb, sk);
1313 err = can_send(skb, 1); /* send with loopback */
1319 return cfsiz + MHSIZ;
1323 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1325 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1327 struct sock *sk = sock->sk;
1328 struct bcm_sock *bo = bcm_sk(sk);
1329 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1330 struct bcm_msg_head msg_head;
1332 int ret; /* read bytes or error codes as return value */
1337 /* check for valid message length from userspace */
1341 /* read message head information */
1342 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1346 cfsiz = CFSIZ(msg_head.flags);
1347 if ((size - MHSIZ) % cfsiz)
1350 /* check for alternative ifindex for this bcm_op */
1352 if (!ifindex && msg->msg_name) {
1353 /* no bound device as default => check msg_name */
1354 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1356 if (msg->msg_namelen < sizeof(*addr))
1359 if (addr->can_family != AF_CAN)
1362 /* ifindex from sendto() */
1363 ifindex = addr->can_ifindex;
1366 struct net_device *dev;
1368 dev = dev_get_by_index(sock_net(sk), ifindex);
1372 if (dev->type != ARPHRD_CAN) {
1383 switch (msg_head.opcode) {
1386 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1390 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1394 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1401 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1408 /* reuse msg_head for the reply to TX_READ */
1409 msg_head.opcode = TX_STATUS;
1410 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1414 /* reuse msg_head for the reply to RX_READ */
1415 msg_head.opcode = RX_STATUS;
1416 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1420 /* we need exactly one CAN frame behind the msg head */
1421 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1424 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1438 * notification handler for netdevice status changes
1440 static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1441 struct net_device *dev)
1443 struct sock *sk = &bo->sk;
1445 int notify_enodev = 0;
1447 if (!net_eq(dev_net(dev), sock_net(sk)))
1452 case NETDEV_UNREGISTER:
1455 /* remove device specific receive entries */
1456 list_for_each_entry(op, &bo->rx_ops, list)
1457 if (op->rx_reg_dev == dev)
1458 bcm_rx_unreg(dev, op);
1460 /* remove device reference, if this is our bound device */
1461 if (bo->bound && bo->ifindex == dev->ifindex) {
1469 if (notify_enodev) {
1470 sk->sk_err = ENODEV;
1471 if (!sock_flag(sk, SOCK_DEAD))
1472 sk->sk_error_report(sk);
1477 if (bo->bound && bo->ifindex == dev->ifindex) {
1478 sk->sk_err = ENETDOWN;
1479 if (!sock_flag(sk, SOCK_DEAD))
1480 sk->sk_error_report(sk);
1485 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1488 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1490 if (dev->type != ARPHRD_CAN)
1492 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1494 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1497 spin_lock(&bcm_notifier_lock);
1498 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1499 spin_unlock(&bcm_notifier_lock);
1500 bcm_notify(bcm_busy_notifier, msg, dev);
1501 spin_lock(&bcm_notifier_lock);
1503 bcm_busy_notifier = NULL;
1504 spin_unlock(&bcm_notifier_lock);
1509 * initial settings for all BCM sockets to be set at socket creation time
1511 static int bcm_init(struct sock *sk)
1513 struct bcm_sock *bo = bcm_sk(sk);
1517 bo->dropped_usr_msgs = 0;
1518 bo->bcm_proc_read = NULL;
1520 INIT_LIST_HEAD(&bo->tx_ops);
1521 INIT_LIST_HEAD(&bo->rx_ops);
1524 spin_lock(&bcm_notifier_lock);
1525 list_add_tail(&bo->notifier, &bcm_notifier_list);
1526 spin_unlock(&bcm_notifier_lock);
1532 * standard socket functions
1534 static int bcm_release(struct socket *sock)
1536 struct sock *sk = sock->sk;
1538 struct bcm_sock *bo;
1539 struct bcm_op *op, *next;
1547 /* remove bcm_ops, timer, rx_unregister(), etc. */
1549 spin_lock(&bcm_notifier_lock);
1550 while (bcm_busy_notifier == bo) {
1551 spin_unlock(&bcm_notifier_lock);
1552 schedule_timeout_uninterruptible(1);
1553 spin_lock(&bcm_notifier_lock);
1555 list_del(&bo->notifier);
1556 spin_unlock(&bcm_notifier_lock);
1560 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1563 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1565 * Don't care if we're bound or not (due to netdev problems)
1566 * can_rx_unregister() is always a save thing to do here.
1570 * Only remove subscriptions that had not
1571 * been removed due to NETDEV_UNREGISTER
1574 if (op->rx_reg_dev) {
1575 struct net_device *dev;
1577 dev = dev_get_by_index(net, op->ifindex);
1579 bcm_rx_unreg(dev, op);
1584 can_rx_unregister(net, NULL, op->can_id,
1585 REGMASK(op->can_id),
1586 bcm_rx_handler, op);
1592 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1595 #if IS_ENABLED(CONFIG_PROC_FS)
1596 /* remove procfs entry */
1597 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1598 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1599 #endif /* CONFIG_PROC_FS */
1601 /* remove device reference */
1616 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1619 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1620 struct sock *sk = sock->sk;
1621 struct bcm_sock *bo = bcm_sk(sk);
1622 struct net *net = sock_net(sk);
1625 if (len < sizeof(*addr))
1635 /* bind a device to this socket */
1636 if (addr->can_ifindex) {
1637 struct net_device *dev;
1639 dev = dev_get_by_index(net, addr->can_ifindex);
1644 if (dev->type != ARPHRD_CAN) {
1650 bo->ifindex = dev->ifindex;
1654 /* no interface reference for ifindex = 0 ('any' CAN device) */
1658 #if IS_ENABLED(CONFIG_PROC_FS)
1659 if (net->can.bcmproc_dir) {
1660 /* unique socket address as filename */
1661 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1662 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1663 net->can.bcmproc_dir,
1665 if (!bo->bcm_proc_read) {
1670 #endif /* CONFIG_PROC_FS */
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 int canbcm_pernet_init(struct net *net)
1753 #if IS_ENABLED(CONFIG_PROC_FS)
1754 /* create /proc/net/can-bcm directory */
1755 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1756 #endif /* CONFIG_PROC_FS */
1761 static void canbcm_pernet_exit(struct net *net)
1763 #if IS_ENABLED(CONFIG_PROC_FS)
1764 /* remove /proc/net/can-bcm directory */
1765 if (net->can.bcmproc_dir)
1766 remove_proc_entry("can-bcm", net->proc_net);
1767 #endif /* CONFIG_PROC_FS */
1770 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1771 .init = canbcm_pernet_init,
1772 .exit = canbcm_pernet_exit,
1775 static struct notifier_block canbcm_notifier = {
1776 .notifier_call = bcm_notifier
1779 static int __init bcm_module_init(void)
1783 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1785 err = can_proto_register(&bcm_can_proto);
1787 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1791 register_pernet_subsys(&canbcm_pernet_ops);
1792 register_netdevice_notifier(&canbcm_notifier);
1796 static void __exit bcm_module_exit(void)
1798 can_proto_unregister(&bcm_can_proto);
1799 unregister_netdevice_notifier(&canbcm_notifier);
1800 unregister_pernet_subsys(&canbcm_pernet_ops);
1803 module_init(bcm_module_init);
1804 module_exit(bcm_module_exit);