2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
4 * Copyright (c) 2002-2017 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 "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);
266 static int bcm_proc_open(struct inode *inode, struct file *file)
268 return single_open_net(inode, file, bcm_proc_show);
271 static const struct file_operations bcm_proc_fops = {
272 .owner = THIS_MODULE,
273 .open = bcm_proc_open,
276 .release = single_release,
278 #endif /* CONFIG_PROC_FS */
281 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
282 * of the given bcm tx op
284 static void bcm_can_tx(struct bcm_op *op)
287 struct net_device *dev;
288 struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
291 /* no target device? => exit */
295 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
297 /* RFC: should this bcm_op remove itself here? */
301 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
305 can_skb_reserve(skb);
306 can_skb_prv(skb)->ifindex = dev->ifindex;
307 can_skb_prv(skb)->skbcnt = 0;
309 skb_put_data(skb, cf, op->cfsiz);
311 /* send with loopback */
313 can_skb_set_owner(skb, op->sk);
314 err = can_send(skb, 1);
320 /* reached last frame? */
321 if (op->currframe >= op->nframes)
328 * bcm_send_to_user - send a BCM message to the userspace
329 * (consisting of bcm_msg_head + x CAN frames)
331 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
332 struct canfd_frame *frames, int has_timestamp)
335 struct canfd_frame *firstframe;
336 struct sockaddr_can *addr;
337 struct sock *sk = op->sk;
338 unsigned int datalen = head->nframes * op->cfsiz;
341 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
345 skb_put_data(skb, head, sizeof(*head));
348 /* CAN frames starting here */
349 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
351 skb_put_data(skb, frames, datalen);
354 * the BCM uses the flags-element of the canfd_frame
355 * structure for internal purposes. This is only
356 * relevant for updates that are generated by the
357 * BCM, where nframes is 1
359 if (head->nframes == 1)
360 firstframe->flags &= BCM_CAN_FLAGS_MASK;
364 /* restore rx timestamp */
365 skb->tstamp = op->rx_stamp;
369 * Put the datagram to the queue so that bcm_recvmsg() can
370 * get it from there. We need to pass the interface index to
371 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
372 * containing the interface index.
375 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
376 addr = (struct sockaddr_can *)skb->cb;
377 memset(addr, 0, sizeof(*addr));
378 addr->can_family = AF_CAN;
379 addr->can_ifindex = op->rx_ifindex;
381 err = sock_queue_rcv_skb(sk, skb);
383 struct bcm_sock *bo = bcm_sk(sk);
386 /* don't care about overflows in this statistic */
387 bo->dropped_usr_msgs++;
391 static void bcm_tx_start_timer(struct bcm_op *op)
393 if (op->kt_ival1 && op->count)
394 hrtimer_start(&op->timer,
395 ktime_add(ktime_get(), op->kt_ival1),
397 else if (op->kt_ival2)
398 hrtimer_start(&op->timer,
399 ktime_add(ktime_get(), op->kt_ival2),
403 static void bcm_tx_timeout_tsklet(unsigned long data)
405 struct bcm_op *op = (struct bcm_op *)data;
406 struct bcm_msg_head msg_head;
408 if (op->kt_ival1 && (op->count > 0)) {
411 if (!op->count && (op->flags & TX_COUNTEVT)) {
413 /* create notification to user */
414 memset(&msg_head, 0, sizeof(msg_head));
415 msg_head.opcode = TX_EXPIRED;
416 msg_head.flags = op->flags;
417 msg_head.count = op->count;
418 msg_head.ival1 = op->ival1;
419 msg_head.ival2 = op->ival2;
420 msg_head.can_id = op->can_id;
421 msg_head.nframes = 0;
423 bcm_send_to_user(op, &msg_head, NULL, 0);
427 } else if (op->kt_ival2)
430 bcm_tx_start_timer(op);
434 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
436 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
438 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
440 tasklet_schedule(&op->tsklet);
442 return HRTIMER_NORESTART;
446 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
448 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
450 struct bcm_msg_head head;
452 /* update statistics */
453 op->frames_filtered++;
455 /* prevent statistics overflow */
456 if (op->frames_filtered > ULONG_MAX/100)
457 op->frames_filtered = op->frames_abs = 0;
459 /* this element is not throttled anymore */
460 data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
462 memset(&head, 0, sizeof(head));
463 head.opcode = RX_CHANGED;
464 head.flags = op->flags;
465 head.count = op->count;
466 head.ival1 = op->ival1;
467 head.ival2 = op->ival2;
468 head.can_id = op->can_id;
471 bcm_send_to_user(op, &head, data, 1);
475 * bcm_rx_update_and_send - process a detected relevant receive content change
476 * 1. update the last received data
477 * 2. send a notification to the user (if possible)
479 static void bcm_rx_update_and_send(struct bcm_op *op,
480 struct canfd_frame *lastdata,
481 const struct canfd_frame *rxdata)
483 memcpy(lastdata, rxdata, op->cfsiz);
485 /* mark as used and throttled by default */
486 lastdata->flags |= (RX_RECV|RX_THR);
488 /* throttling mode inactive ? */
490 /* send RX_CHANGED to the user immediately */
491 bcm_rx_changed(op, lastdata);
495 /* with active throttling timer we are just done here */
496 if (hrtimer_active(&op->thrtimer))
499 /* first reception with enabled throttling mode */
501 goto rx_changed_settime;
503 /* got a second frame inside a potential throttle period? */
504 if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
505 ktime_to_us(op->kt_ival2)) {
506 /* do not send the saved data - only start throttle timer */
507 hrtimer_start(&op->thrtimer,
508 ktime_add(op->kt_lastmsg, op->kt_ival2),
513 /* the gap was that big, that throttling was not needed here */
515 bcm_rx_changed(op, lastdata);
516 op->kt_lastmsg = ktime_get();
520 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
521 * received data stored in op->last_frames[]
523 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
524 const struct canfd_frame *rxdata)
526 struct canfd_frame *cf = op->frames + op->cfsiz * index;
527 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
531 * no one uses the MSBs of flags for comparison,
532 * so we use it here to detect the first time of reception
535 if (!(lcf->flags & RX_RECV)) {
536 /* received data for the first time => send update to user */
537 bcm_rx_update_and_send(op, lcf, rxdata);
541 /* do a real check in CAN frame data section */
542 for (i = 0; i < rxdata->len; i += 8) {
543 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
544 (get_u64(cf, i) & get_u64(lcf, i))) {
545 bcm_rx_update_and_send(op, lcf, rxdata);
550 if (op->flags & RX_CHECK_DLC) {
551 /* do a real check in CAN frame length */
552 if (rxdata->len != lcf->len) {
553 bcm_rx_update_and_send(op, lcf, rxdata);
560 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
562 static void bcm_rx_starttimer(struct bcm_op *op)
564 if (op->flags & RX_NO_AUTOTIMER)
568 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
571 static void bcm_rx_timeout_tsklet(unsigned long data)
573 struct bcm_op *op = (struct bcm_op *)data;
574 struct bcm_msg_head msg_head;
576 /* create notification to user */
577 memset(&msg_head, 0, sizeof(msg_head));
578 msg_head.opcode = RX_TIMEOUT;
579 msg_head.flags = op->flags;
580 msg_head.count = op->count;
581 msg_head.ival1 = op->ival1;
582 msg_head.ival2 = op->ival2;
583 msg_head.can_id = op->can_id;
584 msg_head.nframes = 0;
586 bcm_send_to_user(op, &msg_head, NULL, 0);
590 * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
592 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
594 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
596 /* schedule before NET_RX_SOFTIRQ */
597 tasklet_hi_schedule(&op->tsklet);
599 /* no restart of the timer is done here! */
601 /* if user wants to be informed, when cyclic CAN-Messages come back */
602 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
603 /* clear received CAN frames to indicate 'nothing received' */
604 memset(op->last_frames, 0, op->nframes * op->cfsiz);
607 return HRTIMER_NORESTART;
611 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
613 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
616 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
618 if ((op->last_frames) && (lcf->flags & RX_THR)) {
620 bcm_rx_changed(op, lcf);
627 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
629 * update == 0 : just check if throttled data is available (any irq context)
630 * update == 1 : check and send throttled data to userspace (soft_irq context)
632 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
636 if (op->nframes > 1) {
639 /* for MUX filter we start at index 1 */
640 for (i = 1; i < op->nframes; i++)
641 updated += bcm_rx_do_flush(op, update, i);
644 /* for RX_FILTER_ID and simple filter */
645 updated += bcm_rx_do_flush(op, update, 0);
651 static void bcm_rx_thr_tsklet(unsigned long data)
653 struct bcm_op *op = (struct bcm_op *)data;
655 /* push the changed data to the userspace */
656 bcm_rx_thr_flush(op, 1);
660 * bcm_rx_thr_handler - the time for blocked content updates is over now:
661 * Check for throttled data and send it to the userspace
663 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
665 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
667 tasklet_schedule(&op->thrtsklet);
669 if (bcm_rx_thr_flush(op, 0)) {
670 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
671 return HRTIMER_RESTART;
673 /* rearm throttle handling */
675 return HRTIMER_NORESTART;
680 * bcm_rx_handler - handle a CAN frame reception
682 static void bcm_rx_handler(struct sk_buff *skb, void *data)
684 struct bcm_op *op = (struct bcm_op *)data;
685 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
688 if (op->can_id != rxframe->can_id)
691 /* make sure to handle the correct frame type (CAN / CAN FD) */
692 if (skb->len != op->cfsiz)
695 /* disable timeout */
696 hrtimer_cancel(&op->timer);
698 /* save rx timestamp */
699 op->rx_stamp = skb->tstamp;
700 /* save originator for recvfrom() */
701 op->rx_ifindex = skb->dev->ifindex;
702 /* update statistics */
705 if (op->flags & RX_RTR_FRAME) {
706 /* send reply for RTR-request (placed in op->frames[0]) */
711 if (op->flags & RX_FILTER_ID) {
712 /* the easiest case */
713 bcm_rx_update_and_send(op, op->last_frames, rxframe);
717 if (op->nframes == 1) {
718 /* simple compare with index 0 */
719 bcm_rx_cmp_to_index(op, 0, rxframe);
723 if (op->nframes > 1) {
727 * find the first multiplex mask that fits.
728 * Remark: The MUX-mask is stored in index 0 - but only the
729 * first 64 bits of the frame data[] are relevant (CAN FD)
732 for (i = 1; i < op->nframes; i++) {
733 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
734 (get_u64(op->frames, 0) &
735 get_u64(op->frames + op->cfsiz * i, 0))) {
736 bcm_rx_cmp_to_index(op, i, rxframe);
743 bcm_rx_starttimer(op);
747 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
749 static struct bcm_op *bcm_find_op(struct list_head *ops,
750 struct bcm_msg_head *mh, int ifindex)
754 list_for_each_entry(op, ops, list) {
755 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
756 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
763 static void bcm_remove_op(struct bcm_op *op)
765 if (op->tsklet.func) {
767 tasklet_kill(&op->tsklet);
768 hrtimer_cancel(&op->timer);
769 } while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
770 test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
771 hrtimer_active(&op->timer));
774 if (op->thrtsklet.func) {
776 tasklet_kill(&op->thrtsklet);
777 hrtimer_cancel(&op->thrtimer);
778 } while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
779 test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
780 hrtimer_active(&op->thrtimer));
783 if ((op->frames) && (op->frames != &op->sframe))
786 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
787 kfree(op->last_frames);
792 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
794 if (op->rx_reg_dev == dev) {
795 can_rx_unregister(dev_net(dev), dev, op->can_id,
796 REGMASK(op->can_id), bcm_rx_handler, op);
798 /* mark as removed subscription */
799 op->rx_reg_dev = NULL;
801 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
802 "mismatch %p %p\n", op->rx_reg_dev, dev);
806 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
808 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
811 struct bcm_op *op, *n;
813 list_for_each_entry_safe(op, n, ops, list) {
814 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
815 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
818 * Don't care if we're bound or not (due to netdev
819 * problems) can_rx_unregister() is always a save
824 * Only remove subscriptions that had not
825 * been removed due to NETDEV_UNREGISTER
828 if (op->rx_reg_dev) {
829 struct net_device *dev;
831 dev = dev_get_by_index(sock_net(op->sk),
834 bcm_rx_unreg(dev, op);
839 can_rx_unregister(sock_net(op->sk), NULL,
851 return 0; /* not found */
855 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
857 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
860 struct bcm_op *op, *n;
862 list_for_each_entry_safe(op, n, ops, list) {
863 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
864 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
871 return 0; /* not found */
875 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
877 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
880 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
885 /* put current values into msg_head */
886 msg_head->flags = op->flags;
887 msg_head->count = op->count;
888 msg_head->ival1 = op->ival1;
889 msg_head->ival2 = op->ival2;
890 msg_head->nframes = op->nframes;
892 bcm_send_to_user(op, msg_head, op->frames, 0);
898 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
900 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
901 int ifindex, struct sock *sk)
903 struct bcm_sock *bo = bcm_sk(sk);
905 struct canfd_frame *cf;
909 /* we need a real device to send frames */
913 /* check nframes boundaries - we need at least one CAN frame */
914 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
917 /* check timeval limitations */
918 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
921 /* check the given can_id */
922 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
924 /* update existing BCM operation */
927 * Do we need more space for the CAN frames than currently
928 * allocated? -> This is a _really_ unusual use-case and
929 * therefore (complexity / locking) it is not supported.
931 if (msg_head->nframes > op->nframes)
934 /* update CAN frames content */
935 for (i = 0; i < msg_head->nframes; i++) {
937 cf = op->frames + op->cfsiz * i;
938 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
940 if (op->flags & CAN_FD_FRAME) {
951 if (msg_head->flags & TX_CP_CAN_ID) {
952 /* copy can_id into frame */
953 cf->can_id = msg_head->can_id;
956 op->flags = msg_head->flags;
959 /* insert new BCM operation for the given can_id */
961 op = kzalloc(OPSIZ, GFP_KERNEL);
965 op->can_id = msg_head->can_id;
966 op->cfsiz = CFSIZ(msg_head->flags);
967 op->flags = msg_head->flags;
969 /* create array for CAN frames and copy the data */
970 if (msg_head->nframes > 1) {
971 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
978 op->frames = &op->sframe;
980 for (i = 0; i < msg_head->nframes; i++) {
982 cf = op->frames + op->cfsiz * i;
983 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
987 if (op->flags & CAN_FD_FRAME) {
998 if (msg_head->flags & TX_CP_CAN_ID) {
999 /* copy can_id into frame */
1000 cf->can_id = msg_head->can_id;
1004 /* tx_ops never compare with previous received messages */
1005 op->last_frames = NULL;
1007 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1009 op->ifindex = ifindex;
1011 /* initialize uninitialized (kzalloc) structure */
1012 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1013 op->timer.function = bcm_tx_timeout_handler;
1015 /* initialize tasklet for tx countevent notification */
1016 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
1017 (unsigned long) op);
1019 /* currently unused in tx_ops */
1020 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1022 /* add this bcm_op to the list of the tx_ops */
1023 list_add(&op->list, &bo->tx_ops);
1025 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
1027 if (op->nframes != msg_head->nframes) {
1028 op->nframes = msg_head->nframes;
1029 /* start multiple frame transmission with index 0 */
1035 if (op->flags & TX_RESET_MULTI_IDX) {
1036 /* start multiple frame transmission with index 0 */
1040 if (op->flags & SETTIMER) {
1041 /* set timer values */
1042 op->count = msg_head->count;
1043 op->ival1 = msg_head->ival1;
1044 op->ival2 = msg_head->ival2;
1045 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1046 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1048 /* disable an active timer due to zero values? */
1049 if (!op->kt_ival1 && !op->kt_ival2)
1050 hrtimer_cancel(&op->timer);
1053 if (op->flags & STARTTIMER) {
1054 hrtimer_cancel(&op->timer);
1055 /* spec: send CAN frame when starting timer */
1056 op->flags |= TX_ANNOUNCE;
1059 if (op->flags & TX_ANNOUNCE) {
1065 if (op->flags & STARTTIMER)
1066 bcm_tx_start_timer(op);
1068 return msg_head->nframes * op->cfsiz + MHSIZ;
1071 if (op->frames != &op->sframe)
1078 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1080 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1081 int ifindex, struct sock *sk)
1083 struct bcm_sock *bo = bcm_sk(sk);
1088 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1089 /* be robust against wrong usage ... */
1090 msg_head->flags |= RX_FILTER_ID;
1091 /* ignore trailing garbage */
1092 msg_head->nframes = 0;
1095 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1096 if (msg_head->nframes > MAX_NFRAMES + 1)
1099 if ((msg_head->flags & RX_RTR_FRAME) &&
1100 ((msg_head->nframes != 1) ||
1101 (!(msg_head->can_id & CAN_RTR_FLAG))))
1104 /* check timeval limitations */
1105 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1108 /* check the given can_id */
1109 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1111 /* update existing BCM operation */
1114 * Do we need more space for the CAN frames than currently
1115 * allocated? -> This is a _really_ unusual use-case and
1116 * therefore (complexity / locking) it is not supported.
1118 if (msg_head->nframes > op->nframes)
1121 if (msg_head->nframes) {
1122 /* update CAN frames content */
1123 err = memcpy_from_msg(op->frames, msg,
1124 msg_head->nframes * op->cfsiz);
1128 /* clear last_frames to indicate 'nothing received' */
1129 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1132 op->nframes = msg_head->nframes;
1133 op->flags = msg_head->flags;
1135 /* Only an update -> do not call can_rx_register() */
1139 /* insert new BCM operation for the given can_id */
1140 op = kzalloc(OPSIZ, GFP_KERNEL);
1144 op->can_id = msg_head->can_id;
1145 op->nframes = msg_head->nframes;
1146 op->cfsiz = CFSIZ(msg_head->flags);
1147 op->flags = msg_head->flags;
1149 if (msg_head->nframes > 1) {
1150 /* create array for CAN frames and copy the data */
1151 op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1158 /* create and init array for received CAN frames */
1159 op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1161 if (!op->last_frames) {
1168 op->frames = &op->sframe;
1169 op->last_frames = &op->last_sframe;
1172 if (msg_head->nframes) {
1173 err = memcpy_from_msg(op->frames, msg,
1174 msg_head->nframes * op->cfsiz);
1176 if (op->frames != &op->sframe)
1178 if (op->last_frames != &op->last_sframe)
1179 kfree(op->last_frames);
1185 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1187 op->ifindex = ifindex;
1189 /* ifindex for timeout events w/o previous frame reception */
1190 op->rx_ifindex = ifindex;
1192 /* initialize uninitialized (kzalloc) structure */
1193 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1194 op->timer.function = bcm_rx_timeout_handler;
1196 /* initialize tasklet for rx timeout notification */
1197 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1198 (unsigned long) op);
1200 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1201 op->thrtimer.function = bcm_rx_thr_handler;
1203 /* initialize tasklet for rx throttle handling */
1204 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1205 (unsigned long) op);
1207 /* add this bcm_op to the list of the rx_ops */
1208 list_add(&op->list, &bo->rx_ops);
1210 /* call can_rx_register() */
1213 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1217 if (op->flags & RX_RTR_FRAME) {
1218 struct canfd_frame *frame0 = op->frames;
1220 /* no timers in RTR-mode */
1221 hrtimer_cancel(&op->thrtimer);
1222 hrtimer_cancel(&op->timer);
1225 * funny feature in RX(!)_SETUP only for RTR-mode:
1226 * copy can_id into frame BUT without RTR-flag to
1227 * prevent a full-load-loopback-test ... ;-]
1229 if ((op->flags & TX_CP_CAN_ID) ||
1230 (frame0->can_id == op->can_id))
1231 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1234 if (op->flags & SETTIMER) {
1236 /* set timer value */
1237 op->ival1 = msg_head->ival1;
1238 op->ival2 = msg_head->ival2;
1239 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1240 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1242 /* disable an active timer due to zero value? */
1244 hrtimer_cancel(&op->timer);
1247 * In any case cancel the throttle timer, flush
1248 * potentially blocked msgs and reset throttle handling
1251 hrtimer_cancel(&op->thrtimer);
1252 bcm_rx_thr_flush(op, 1);
1255 if ((op->flags & STARTTIMER) && op->kt_ival1)
1256 hrtimer_start(&op->timer, op->kt_ival1,
1260 /* now we can register for can_ids, if we added a new bcm_op */
1261 if (do_rx_register) {
1263 struct net_device *dev;
1265 dev = dev_get_by_index(sock_net(sk), ifindex);
1267 err = can_rx_register(sock_net(sk), dev,
1269 REGMASK(op->can_id),
1273 op->rx_reg_dev = dev;
1278 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1279 REGMASK(op->can_id),
1280 bcm_rx_handler, op, "bcm", sk);
1282 /* this bcm rx op is broken -> remove it */
1283 list_del(&op->list);
1289 return msg_head->nframes * op->cfsiz + MHSIZ;
1293 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1295 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1298 struct sk_buff *skb;
1299 struct net_device *dev;
1302 /* we need a real device to send frames */
1306 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1310 can_skb_reserve(skb);
1312 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1318 dev = dev_get_by_index(sock_net(sk), ifindex);
1324 can_skb_prv(skb)->ifindex = dev->ifindex;
1325 can_skb_prv(skb)->skbcnt = 0;
1327 can_skb_set_owner(skb, sk);
1328 err = can_send(skb, 1); /* send with loopback */
1334 return cfsiz + MHSIZ;
1338 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1340 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1342 struct sock *sk = sock->sk;
1343 struct bcm_sock *bo = bcm_sk(sk);
1344 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1345 struct bcm_msg_head msg_head;
1347 int ret; /* read bytes or error codes as return value */
1352 /* check for valid message length from userspace */
1356 /* read message head information */
1357 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1361 cfsiz = CFSIZ(msg_head.flags);
1362 if ((size - MHSIZ) % cfsiz)
1365 /* check for alternative ifindex for this bcm_op */
1367 if (!ifindex && msg->msg_name) {
1368 /* no bound device as default => check msg_name */
1369 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1371 if (msg->msg_namelen < sizeof(*addr))
1374 if (addr->can_family != AF_CAN)
1377 /* ifindex from sendto() */
1378 ifindex = addr->can_ifindex;
1381 struct net_device *dev;
1383 dev = dev_get_by_index(sock_net(sk), ifindex);
1387 if (dev->type != ARPHRD_CAN) {
1398 switch (msg_head.opcode) {
1401 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1405 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1409 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1416 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1423 /* reuse msg_head for the reply to TX_READ */
1424 msg_head.opcode = TX_STATUS;
1425 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1429 /* reuse msg_head for the reply to RX_READ */
1430 msg_head.opcode = RX_STATUS;
1431 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1435 /* we need exactly one CAN frame behind the msg head */
1436 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1439 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1453 * notification handler for netdevice status changes
1455 static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1456 struct net_device *dev)
1458 struct sock *sk = &bo->sk;
1460 int notify_enodev = 0;
1462 if (!net_eq(dev_net(dev), sock_net(sk)))
1467 case NETDEV_UNREGISTER:
1470 /* remove device specific receive entries */
1471 list_for_each_entry(op, &bo->rx_ops, list)
1472 if (op->rx_reg_dev == dev)
1473 bcm_rx_unreg(dev, op);
1475 /* remove device reference, if this is our bound device */
1476 if (bo->bound && bo->ifindex == dev->ifindex) {
1484 if (notify_enodev) {
1485 sk->sk_err = ENODEV;
1486 if (!sock_flag(sk, SOCK_DEAD))
1487 sk->sk_error_report(sk);
1492 if (bo->bound && bo->ifindex == dev->ifindex) {
1493 sk->sk_err = ENETDOWN;
1494 if (!sock_flag(sk, SOCK_DEAD))
1495 sk->sk_error_report(sk);
1500 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1503 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1505 if (dev->type != ARPHRD_CAN)
1507 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1509 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1512 spin_lock(&bcm_notifier_lock);
1513 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1514 spin_unlock(&bcm_notifier_lock);
1515 bcm_notify(bcm_busy_notifier, msg, dev);
1516 spin_lock(&bcm_notifier_lock);
1518 bcm_busy_notifier = NULL;
1519 spin_unlock(&bcm_notifier_lock);
1524 * initial settings for all BCM sockets to be set at socket creation time
1526 static int bcm_init(struct sock *sk)
1528 struct bcm_sock *bo = bcm_sk(sk);
1532 bo->dropped_usr_msgs = 0;
1533 bo->bcm_proc_read = NULL;
1535 INIT_LIST_HEAD(&bo->tx_ops);
1536 INIT_LIST_HEAD(&bo->rx_ops);
1539 spin_lock(&bcm_notifier_lock);
1540 list_add_tail(&bo->notifier, &bcm_notifier_list);
1541 spin_unlock(&bcm_notifier_lock);
1547 * standard socket functions
1549 static int bcm_release(struct socket *sock)
1551 struct sock *sk = sock->sk;
1553 struct bcm_sock *bo;
1554 struct bcm_op *op, *next;
1562 /* remove bcm_ops, timer, rx_unregister(), etc. */
1564 spin_lock(&bcm_notifier_lock);
1565 while (bcm_busy_notifier == bo) {
1566 spin_unlock(&bcm_notifier_lock);
1567 schedule_timeout_uninterruptible(1);
1568 spin_lock(&bcm_notifier_lock);
1570 list_del(&bo->notifier);
1571 spin_unlock(&bcm_notifier_lock);
1575 #if IS_ENABLED(CONFIG_PROC_FS)
1576 /* remove procfs entry */
1577 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1578 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1579 #endif /* CONFIG_PROC_FS */
1581 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1584 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1586 * Don't care if we're bound or not (due to netdev problems)
1587 * can_rx_unregister() is always a save thing to do here.
1591 * Only remove subscriptions that had not
1592 * been removed due to NETDEV_UNREGISTER
1595 if (op->rx_reg_dev) {
1596 struct net_device *dev;
1598 dev = dev_get_by_index(net, op->ifindex);
1600 bcm_rx_unreg(dev, op);
1605 can_rx_unregister(net, NULL, op->can_id,
1606 REGMASK(op->can_id),
1607 bcm_rx_handler, op);
1613 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1616 /* remove device reference */
1631 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1634 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1635 struct sock *sk = sock->sk;
1636 struct bcm_sock *bo = bcm_sk(sk);
1637 struct net *net = sock_net(sk);
1640 if (len < sizeof(*addr))
1650 /* bind a device to this socket */
1651 if (addr->can_ifindex) {
1652 struct net_device *dev;
1654 dev = dev_get_by_index(net, addr->can_ifindex);
1659 if (dev->type != ARPHRD_CAN) {
1665 bo->ifindex = dev->ifindex;
1669 /* no interface reference for ifindex = 0 ('any' CAN device) */
1673 #if IS_ENABLED(CONFIG_PROC_FS)
1674 if (net->can.bcmproc_dir) {
1675 /* unique socket address as filename */
1676 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1677 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1678 net->can.bcmproc_dir,
1679 &bcm_proc_fops, sk);
1680 if (!bo->bcm_proc_read) {
1685 #endif /* CONFIG_PROC_FS */
1695 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1698 struct sock *sk = sock->sk;
1699 struct sk_buff *skb;
1704 noblock = flags & MSG_DONTWAIT;
1705 flags &= ~MSG_DONTWAIT;
1706 skb = skb_recv_datagram(sk, flags, noblock, &error);
1710 if (skb->len < size)
1713 err = memcpy_to_msg(msg, skb->data, size);
1715 skb_free_datagram(sk, skb);
1719 sock_recv_ts_and_drops(msg, sk, skb);
1721 if (msg->msg_name) {
1722 __sockaddr_check_size(sizeof(struct sockaddr_can));
1723 msg->msg_namelen = sizeof(struct sockaddr_can);
1724 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1727 skb_free_datagram(sk, skb);
1732 static const struct proto_ops bcm_ops = {
1734 .release = bcm_release,
1735 .bind = sock_no_bind,
1736 .connect = bcm_connect,
1737 .socketpair = sock_no_socketpair,
1738 .accept = sock_no_accept,
1739 .getname = sock_no_getname,
1740 .poll = datagram_poll,
1741 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1742 .listen = sock_no_listen,
1743 .shutdown = sock_no_shutdown,
1744 .setsockopt = sock_no_setsockopt,
1745 .getsockopt = sock_no_getsockopt,
1746 .sendmsg = bcm_sendmsg,
1747 .recvmsg = bcm_recvmsg,
1748 .mmap = sock_no_mmap,
1749 .sendpage = sock_no_sendpage,
1752 static struct proto bcm_proto __read_mostly = {
1754 .owner = THIS_MODULE,
1755 .obj_size = sizeof(struct bcm_sock),
1759 static const struct can_proto bcm_can_proto = {
1761 .protocol = CAN_BCM,
1766 static int canbcm_pernet_init(struct net *net)
1768 #if IS_ENABLED(CONFIG_PROC_FS)
1769 /* create /proc/net/can-bcm directory */
1770 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1771 #endif /* CONFIG_PROC_FS */
1776 static void canbcm_pernet_exit(struct net *net)
1778 #if IS_ENABLED(CONFIG_PROC_FS)
1779 /* remove /proc/net/can-bcm directory */
1780 if (net->can.bcmproc_dir)
1781 remove_proc_entry("can-bcm", net->proc_net);
1782 #endif /* CONFIG_PROC_FS */
1785 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1786 .init = canbcm_pernet_init,
1787 .exit = canbcm_pernet_exit,
1790 static struct notifier_block canbcm_notifier = {
1791 .notifier_call = bcm_notifier
1794 static int __init bcm_module_init(void)
1798 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1800 err = can_proto_register(&bcm_can_proto);
1802 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1806 register_pernet_subsys(&canbcm_pernet_ops);
1807 register_netdevice_notifier(&canbcm_notifier);
1811 static void __exit bcm_module_exit(void)
1813 can_proto_unregister(&bcm_can_proto);
1814 unregister_netdevice_notifier(&canbcm_notifier);
1815 unregister_pernet_subsys(&canbcm_pernet_ops);
1818 module_init(bcm_module_init);
1819 module_exit(bcm_module_exit);