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;
106 unsigned long frames_abs, frames_filtered;
107 struct bcm_timeval ival1, ival2;
108 struct hrtimer timer, thrtimer;
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;
278 /* no target device? => exit */
282 dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
284 /* RFC: should this bcm_op remove itself here? */
288 skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
292 can_skb_reserve(skb);
293 can_skb_prv(skb)->ifindex = dev->ifindex;
294 can_skb_prv(skb)->skbcnt = 0;
296 skb_put_data(skb, cf, op->cfsiz);
298 /* send with loopback */
300 can_skb_set_owner(skb, op->sk);
301 err = can_send(skb, 1);
307 /* reached last frame? */
308 if (op->currframe >= op->nframes)
315 * bcm_send_to_user - send a BCM message to the userspace
316 * (consisting of bcm_msg_head + x CAN frames)
318 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
319 struct canfd_frame *frames, int has_timestamp)
322 struct canfd_frame *firstframe;
323 struct sockaddr_can *addr;
324 struct sock *sk = op->sk;
325 unsigned int datalen = head->nframes * op->cfsiz;
328 skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
332 skb_put_data(skb, head, sizeof(*head));
335 /* CAN frames starting here */
336 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
338 skb_put_data(skb, frames, datalen);
341 * the BCM uses the flags-element of the canfd_frame
342 * structure for internal purposes. This is only
343 * relevant for updates that are generated by the
344 * BCM, where nframes is 1
346 if (head->nframes == 1)
347 firstframe->flags &= BCM_CAN_FLAGS_MASK;
351 /* restore rx timestamp */
352 skb->tstamp = op->rx_stamp;
356 * Put the datagram to the queue so that bcm_recvmsg() can
357 * get it from there. We need to pass the interface index to
358 * bcm_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
359 * containing the interface index.
362 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
363 addr = (struct sockaddr_can *)skb->cb;
364 memset(addr, 0, sizeof(*addr));
365 addr->can_family = AF_CAN;
366 addr->can_ifindex = op->rx_ifindex;
368 err = sock_queue_rcv_skb(sk, skb);
370 struct bcm_sock *bo = bcm_sk(sk);
373 /* don't care about overflows in this statistic */
374 bo->dropped_usr_msgs++;
378 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
382 if (op->kt_ival1 && op->count)
384 else if (op->kt_ival2)
389 hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
393 static void bcm_tx_start_timer(struct bcm_op *op)
395 if (bcm_tx_set_expiry(op, &op->timer))
396 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
399 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
400 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
402 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
403 struct bcm_msg_head msg_head;
405 if (op->kt_ival1 && (op->count > 0)) {
407 if (!op->count && (op->flags & TX_COUNTEVT)) {
409 /* create notification to user */
410 memset(&msg_head, 0, sizeof(msg_head));
411 msg_head.opcode = TX_EXPIRED;
412 msg_head.flags = op->flags;
413 msg_head.count = op->count;
414 msg_head.ival1 = op->ival1;
415 msg_head.ival2 = op->ival2;
416 msg_head.can_id = op->can_id;
417 msg_head.nframes = 0;
419 bcm_send_to_user(op, &msg_head, NULL, 0);
423 } else if (op->kt_ival2) {
427 return bcm_tx_set_expiry(op, &op->timer) ?
428 HRTIMER_RESTART : 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),
495 HRTIMER_MODE_ABS_SOFT);
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_SOFT);
557 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
558 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
560 struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
561 struct bcm_msg_head msg_head;
563 /* if user wants to be informed, when cyclic CAN-Messages come back */
564 if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
565 /* clear received CAN frames to indicate 'nothing received' */
566 memset(op->last_frames, 0, op->nframes * op->cfsiz);
569 /* create notification to user */
570 memset(&msg_head, 0, sizeof(msg_head));
571 msg_head.opcode = RX_TIMEOUT;
572 msg_head.flags = op->flags;
573 msg_head.count = op->count;
574 msg_head.ival1 = op->ival1;
575 msg_head.ival2 = op->ival2;
576 msg_head.can_id = op->can_id;
577 msg_head.nframes = 0;
579 bcm_send_to_user(op, &msg_head, NULL, 0);
581 return HRTIMER_NORESTART;
585 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
587 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
589 struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
591 if ((op->last_frames) && (lcf->flags & RX_THR)) {
592 bcm_rx_changed(op, lcf);
599 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
601 static int bcm_rx_thr_flush(struct bcm_op *op)
605 if (op->nframes > 1) {
608 /* for MUX filter we start at index 1 */
609 for (i = 1; i < op->nframes; i++)
610 updated += bcm_rx_do_flush(op, i);
613 /* for RX_FILTER_ID and simple filter */
614 updated += bcm_rx_do_flush(op, 0);
621 * bcm_rx_thr_handler - the time for blocked content updates is over now:
622 * Check for throttled data and send it to the userspace
624 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
626 struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
628 if (bcm_rx_thr_flush(op)) {
629 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
630 return HRTIMER_RESTART;
632 /* rearm throttle handling */
634 return HRTIMER_NORESTART;
639 * bcm_rx_handler - handle a CAN frame reception
641 static void bcm_rx_handler(struct sk_buff *skb, void *data)
643 struct bcm_op *op = (struct bcm_op *)data;
644 const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
647 if (op->can_id != rxframe->can_id)
650 /* make sure to handle the correct frame type (CAN / CAN FD) */
651 if (skb->len != op->cfsiz)
654 /* disable timeout */
655 hrtimer_cancel(&op->timer);
657 /* save rx timestamp */
658 op->rx_stamp = skb->tstamp;
659 /* save originator for recvfrom() */
660 op->rx_ifindex = skb->dev->ifindex;
661 /* update statistics */
664 if (op->flags & RX_RTR_FRAME) {
665 /* send reply for RTR-request (placed in op->frames[0]) */
670 if (op->flags & RX_FILTER_ID) {
671 /* the easiest case */
672 bcm_rx_update_and_send(op, op->last_frames, rxframe);
676 if (op->nframes == 1) {
677 /* simple compare with index 0 */
678 bcm_rx_cmp_to_index(op, 0, rxframe);
682 if (op->nframes > 1) {
686 * find the first multiplex mask that fits.
687 * Remark: The MUX-mask is stored in index 0 - but only the
688 * first 64 bits of the frame data[] are relevant (CAN FD)
691 for (i = 1; i < op->nframes; i++) {
692 if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
693 (get_u64(op->frames, 0) &
694 get_u64(op->frames + op->cfsiz * i, 0))) {
695 bcm_rx_cmp_to_index(op, i, rxframe);
702 bcm_rx_starttimer(op);
706 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
708 static struct bcm_op *bcm_find_op(struct list_head *ops,
709 struct bcm_msg_head *mh, int ifindex)
713 list_for_each_entry(op, ops, list) {
714 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
715 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
722 static void bcm_free_op_rcu(struct rcu_head *rcu_head)
724 struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
726 if ((op->frames) && (op->frames != &op->sframe))
729 if ((op->last_frames) && (op->last_frames != &op->last_sframe))
730 kfree(op->last_frames);
735 static void bcm_remove_op(struct bcm_op *op)
737 hrtimer_cancel(&op->timer);
738 hrtimer_cancel(&op->thrtimer);
740 call_rcu(&op->rcu, bcm_free_op_rcu);
743 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
745 if (op->rx_reg_dev == dev) {
746 can_rx_unregister(dev_net(dev), dev, op->can_id,
747 REGMASK(op->can_id), bcm_rx_handler, op);
749 /* mark as removed subscription */
750 op->rx_reg_dev = NULL;
752 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
753 "mismatch %p %p\n", op->rx_reg_dev, dev);
757 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
759 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
762 struct bcm_op *op, *n;
764 list_for_each_entry_safe(op, n, ops, list) {
765 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
766 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
768 /* disable automatic timer on frame reception */
769 op->flags |= RX_NO_AUTOTIMER;
772 * Don't care if we're bound or not (due to netdev
773 * problems) can_rx_unregister() is always a save
778 * Only remove subscriptions that had not
779 * been removed due to NETDEV_UNREGISTER
782 if (op->rx_reg_dev) {
783 struct net_device *dev;
785 dev = dev_get_by_index(sock_net(op->sk),
788 bcm_rx_unreg(dev, op);
793 can_rx_unregister(sock_net(op->sk), NULL,
804 return 0; /* not found */
808 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
810 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
813 struct bcm_op *op, *n;
815 list_for_each_entry_safe(op, n, ops, list) {
816 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
817 (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
824 return 0; /* not found */
828 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
830 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
833 struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
838 /* put current values into msg_head */
839 msg_head->flags = op->flags;
840 msg_head->count = op->count;
841 msg_head->ival1 = op->ival1;
842 msg_head->ival2 = op->ival2;
843 msg_head->nframes = op->nframes;
845 bcm_send_to_user(op, msg_head, op->frames, 0);
851 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
853 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
854 int ifindex, struct sock *sk)
856 struct bcm_sock *bo = bcm_sk(sk);
858 struct canfd_frame *cf;
862 /* we need a real device to send frames */
866 /* check nframes boundaries - we need at least one CAN frame */
867 if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
870 /* check timeval limitations */
871 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
874 /* check the given can_id */
875 op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
877 /* update existing BCM operation */
880 * Do we need more space for the CAN frames than currently
881 * allocated? -> This is a _really_ unusual use-case and
882 * therefore (complexity / locking) it is not supported.
884 if (msg_head->nframes > op->nframes)
887 /* update CAN frames content */
888 for (i = 0; i < msg_head->nframes; i++) {
890 cf = op->frames + op->cfsiz * i;
891 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
893 if (op->flags & CAN_FD_FRAME) {
904 if (msg_head->flags & TX_CP_CAN_ID) {
905 /* copy can_id into frame */
906 cf->can_id = msg_head->can_id;
909 op->flags = msg_head->flags;
912 /* insert new BCM operation for the given can_id */
914 op = kzalloc(OPSIZ, GFP_KERNEL);
918 op->can_id = msg_head->can_id;
919 op->cfsiz = CFSIZ(msg_head->flags);
920 op->flags = msg_head->flags;
922 /* create array for CAN frames and copy the data */
923 if (msg_head->nframes > 1) {
924 op->frames = kmalloc_array(msg_head->nframes,
932 op->frames = &op->sframe;
934 for (i = 0; i < msg_head->nframes; i++) {
936 cf = op->frames + op->cfsiz * i;
937 err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
941 if (op->flags & CAN_FD_FRAME) {
952 if (msg_head->flags & TX_CP_CAN_ID) {
953 /* copy can_id into frame */
954 cf->can_id = msg_head->can_id;
958 /* tx_ops never compare with previous received messages */
959 op->last_frames = NULL;
961 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
963 op->ifindex = ifindex;
965 /* initialize uninitialized (kzalloc) structure */
966 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
967 HRTIMER_MODE_REL_SOFT);
968 op->timer.function = bcm_tx_timeout_handler;
970 /* currently unused in tx_ops */
971 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
972 HRTIMER_MODE_REL_SOFT);
974 /* add this bcm_op to the list of the tx_ops */
975 list_add(&op->list, &bo->tx_ops);
977 } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
979 if (op->nframes != msg_head->nframes) {
980 op->nframes = msg_head->nframes;
981 /* start multiple frame transmission with index 0 */
987 if (op->flags & TX_RESET_MULTI_IDX) {
988 /* start multiple frame transmission with index 0 */
992 if (op->flags & SETTIMER) {
993 /* set timer values */
994 op->count = msg_head->count;
995 op->ival1 = msg_head->ival1;
996 op->ival2 = msg_head->ival2;
997 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
998 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1000 /* disable an active timer due to zero values? */
1001 if (!op->kt_ival1 && !op->kt_ival2)
1002 hrtimer_cancel(&op->timer);
1005 if (op->flags & STARTTIMER) {
1006 hrtimer_cancel(&op->timer);
1007 /* spec: send CAN frame when starting timer */
1008 op->flags |= TX_ANNOUNCE;
1011 if (op->flags & TX_ANNOUNCE) {
1017 if (op->flags & STARTTIMER)
1018 bcm_tx_start_timer(op);
1020 return msg_head->nframes * op->cfsiz + MHSIZ;
1023 if (op->frames != &op->sframe)
1030 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1032 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1033 int ifindex, struct sock *sk)
1035 struct bcm_sock *bo = bcm_sk(sk);
1040 if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1041 /* be robust against wrong usage ... */
1042 msg_head->flags |= RX_FILTER_ID;
1043 /* ignore trailing garbage */
1044 msg_head->nframes = 0;
1047 /* the first element contains the mux-mask => MAX_NFRAMES + 1 */
1048 if (msg_head->nframes > MAX_NFRAMES + 1)
1051 if ((msg_head->flags & RX_RTR_FRAME) &&
1052 ((msg_head->nframes != 1) ||
1053 (!(msg_head->can_id & CAN_RTR_FLAG))))
1056 /* check timeval limitations */
1057 if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1060 /* check the given can_id */
1061 op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1063 /* update existing BCM operation */
1066 * Do we need more space for the CAN frames than currently
1067 * allocated? -> This is a _really_ unusual use-case and
1068 * therefore (complexity / locking) it is not supported.
1070 if (msg_head->nframes > op->nframes)
1073 if (msg_head->nframes) {
1074 /* update CAN frames content */
1075 err = memcpy_from_msg(op->frames, msg,
1076 msg_head->nframes * op->cfsiz);
1080 /* clear last_frames to indicate 'nothing received' */
1081 memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1084 op->nframes = msg_head->nframes;
1085 op->flags = msg_head->flags;
1087 /* Only an update -> do not call can_rx_register() */
1091 /* insert new BCM operation for the given can_id */
1092 op = kzalloc(OPSIZ, GFP_KERNEL);
1096 op->can_id = msg_head->can_id;
1097 op->nframes = msg_head->nframes;
1098 op->cfsiz = CFSIZ(msg_head->flags);
1099 op->flags = msg_head->flags;
1101 if (msg_head->nframes > 1) {
1102 /* create array for CAN frames and copy the data */
1103 op->frames = kmalloc_array(msg_head->nframes,
1111 /* create and init array for received CAN frames */
1112 op->last_frames = kcalloc(msg_head->nframes,
1115 if (!op->last_frames) {
1122 op->frames = &op->sframe;
1123 op->last_frames = &op->last_sframe;
1126 if (msg_head->nframes) {
1127 err = memcpy_from_msg(op->frames, msg,
1128 msg_head->nframes * op->cfsiz);
1130 if (op->frames != &op->sframe)
1132 if (op->last_frames != &op->last_sframe)
1133 kfree(op->last_frames);
1139 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1141 op->ifindex = ifindex;
1143 /* ifindex for timeout events w/o previous frame reception */
1144 op->rx_ifindex = ifindex;
1146 /* initialize uninitialized (kzalloc) structure */
1147 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1148 HRTIMER_MODE_REL_SOFT);
1149 op->timer.function = bcm_rx_timeout_handler;
1151 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1152 HRTIMER_MODE_REL_SOFT);
1153 op->thrtimer.function = bcm_rx_thr_handler;
1155 /* add this bcm_op to the list of the rx_ops */
1156 list_add(&op->list, &bo->rx_ops);
1158 /* call can_rx_register() */
1161 } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1165 if (op->flags & RX_RTR_FRAME) {
1166 struct canfd_frame *frame0 = op->frames;
1168 /* no timers in RTR-mode */
1169 hrtimer_cancel(&op->thrtimer);
1170 hrtimer_cancel(&op->timer);
1173 * funny feature in RX(!)_SETUP only for RTR-mode:
1174 * copy can_id into frame BUT without RTR-flag to
1175 * prevent a full-load-loopback-test ... ;-]
1177 if ((op->flags & TX_CP_CAN_ID) ||
1178 (frame0->can_id == op->can_id))
1179 frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1182 if (op->flags & SETTIMER) {
1184 /* set timer value */
1185 op->ival1 = msg_head->ival1;
1186 op->ival2 = msg_head->ival2;
1187 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1188 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1190 /* disable an active timer due to zero value? */
1192 hrtimer_cancel(&op->timer);
1195 * In any case cancel the throttle timer, flush
1196 * potentially blocked msgs and reset throttle handling
1199 hrtimer_cancel(&op->thrtimer);
1200 bcm_rx_thr_flush(op);
1203 if ((op->flags & STARTTIMER) && op->kt_ival1)
1204 hrtimer_start(&op->timer, op->kt_ival1,
1205 HRTIMER_MODE_REL_SOFT);
1208 /* now we can register for can_ids, if we added a new bcm_op */
1209 if (do_rx_register) {
1211 struct net_device *dev;
1213 dev = dev_get_by_index(sock_net(sk), ifindex);
1215 err = can_rx_register(sock_net(sk), dev,
1217 REGMASK(op->can_id),
1221 op->rx_reg_dev = dev;
1226 err = can_rx_register(sock_net(sk), NULL, op->can_id,
1227 REGMASK(op->can_id),
1228 bcm_rx_handler, op, "bcm", sk);
1230 /* this bcm rx op is broken -> remove it */
1231 list_del(&op->list);
1237 return msg_head->nframes * op->cfsiz + MHSIZ;
1241 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1243 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1246 struct sk_buff *skb;
1247 struct net_device *dev;
1250 /* we need a real device to send frames */
1254 skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1258 can_skb_reserve(skb);
1260 err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1266 dev = dev_get_by_index(sock_net(sk), ifindex);
1272 can_skb_prv(skb)->ifindex = dev->ifindex;
1273 can_skb_prv(skb)->skbcnt = 0;
1275 can_skb_set_owner(skb, sk);
1276 err = can_send(skb, 1); /* send with loopback */
1282 return cfsiz + MHSIZ;
1286 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1288 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1290 struct sock *sk = sock->sk;
1291 struct bcm_sock *bo = bcm_sk(sk);
1292 int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1293 struct bcm_msg_head msg_head;
1295 int ret; /* read bytes or error codes as return value */
1300 /* check for valid message length from userspace */
1304 /* read message head information */
1305 ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1309 cfsiz = CFSIZ(msg_head.flags);
1310 if ((size - MHSIZ) % cfsiz)
1313 /* check for alternative ifindex for this bcm_op */
1315 if (!ifindex && msg->msg_name) {
1316 /* no bound device as default => check msg_name */
1317 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1319 if (msg->msg_namelen < sizeof(*addr))
1322 if (addr->can_family != AF_CAN)
1325 /* ifindex from sendto() */
1326 ifindex = addr->can_ifindex;
1329 struct net_device *dev;
1331 dev = dev_get_by_index(sock_net(sk), ifindex);
1335 if (dev->type != ARPHRD_CAN) {
1346 switch (msg_head.opcode) {
1349 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1353 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1357 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1364 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1371 /* reuse msg_head for the reply to TX_READ */
1372 msg_head.opcode = TX_STATUS;
1373 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1377 /* reuse msg_head for the reply to RX_READ */
1378 msg_head.opcode = RX_STATUS;
1379 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1383 /* we need exactly one CAN frame behind the msg head */
1384 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1387 ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1401 * notification handler for netdevice status changes
1403 static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1404 struct net_device *dev)
1406 struct sock *sk = &bo->sk;
1408 int notify_enodev = 0;
1410 if (!net_eq(dev_net(dev), sock_net(sk)))
1415 case NETDEV_UNREGISTER:
1418 /* remove device specific receive entries */
1419 list_for_each_entry(op, &bo->rx_ops, list)
1420 if (op->rx_reg_dev == dev)
1421 bcm_rx_unreg(dev, op);
1423 /* remove device reference, if this is our bound device */
1424 if (bo->bound && bo->ifindex == dev->ifindex) {
1432 if (notify_enodev) {
1433 sk->sk_err = ENODEV;
1434 if (!sock_flag(sk, SOCK_DEAD))
1435 sk->sk_error_report(sk);
1440 if (bo->bound && bo->ifindex == dev->ifindex) {
1441 sk->sk_err = ENETDOWN;
1442 if (!sock_flag(sk, SOCK_DEAD))
1443 sk->sk_error_report(sk);
1448 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1451 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1453 if (dev->type != ARPHRD_CAN)
1455 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1457 if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1460 spin_lock(&bcm_notifier_lock);
1461 list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1462 spin_unlock(&bcm_notifier_lock);
1463 bcm_notify(bcm_busy_notifier, msg, dev);
1464 spin_lock(&bcm_notifier_lock);
1466 bcm_busy_notifier = NULL;
1467 spin_unlock(&bcm_notifier_lock);
1472 * initial settings for all BCM sockets to be set at socket creation time
1474 static int bcm_init(struct sock *sk)
1476 struct bcm_sock *bo = bcm_sk(sk);
1480 bo->dropped_usr_msgs = 0;
1481 bo->bcm_proc_read = NULL;
1483 INIT_LIST_HEAD(&bo->tx_ops);
1484 INIT_LIST_HEAD(&bo->rx_ops);
1487 spin_lock(&bcm_notifier_lock);
1488 list_add_tail(&bo->notifier, &bcm_notifier_list);
1489 spin_unlock(&bcm_notifier_lock);
1495 * standard socket functions
1497 static int bcm_release(struct socket *sock)
1499 struct sock *sk = sock->sk;
1501 struct bcm_sock *bo;
1502 struct bcm_op *op, *next;
1510 /* remove bcm_ops, timer, rx_unregister(), etc. */
1512 spin_lock(&bcm_notifier_lock);
1513 while (bcm_busy_notifier == bo) {
1514 spin_unlock(&bcm_notifier_lock);
1515 schedule_timeout_uninterruptible(1);
1516 spin_lock(&bcm_notifier_lock);
1518 list_del(&bo->notifier);
1519 spin_unlock(&bcm_notifier_lock);
1523 list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1526 list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1528 * Don't care if we're bound or not (due to netdev problems)
1529 * can_rx_unregister() is always a save thing to do here.
1533 * Only remove subscriptions that had not
1534 * been removed due to NETDEV_UNREGISTER
1537 if (op->rx_reg_dev) {
1538 struct net_device *dev;
1540 dev = dev_get_by_index(net, op->ifindex);
1542 bcm_rx_unreg(dev, op);
1547 can_rx_unregister(net, NULL, op->can_id,
1548 REGMASK(op->can_id),
1549 bcm_rx_handler, op);
1555 list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1558 #if IS_ENABLED(CONFIG_PROC_FS)
1559 /* remove procfs entry */
1560 if (net->can.bcmproc_dir && bo->bcm_proc_read)
1561 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1562 #endif /* CONFIG_PROC_FS */
1564 /* remove device reference */
1579 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1582 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1583 struct sock *sk = sock->sk;
1584 struct bcm_sock *bo = bcm_sk(sk);
1585 struct net *net = sock_net(sk);
1588 if (len < sizeof(*addr))
1598 /* bind a device to this socket */
1599 if (addr->can_ifindex) {
1600 struct net_device *dev;
1602 dev = dev_get_by_index(net, addr->can_ifindex);
1607 if (dev->type != ARPHRD_CAN) {
1613 bo->ifindex = dev->ifindex;
1617 /* no interface reference for ifindex = 0 ('any' CAN device) */
1621 #if IS_ENABLED(CONFIG_PROC_FS)
1622 if (net->can.bcmproc_dir) {
1623 /* unique socket address as filename */
1624 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1625 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1626 net->can.bcmproc_dir,
1628 if (!bo->bcm_proc_read) {
1633 #endif /* CONFIG_PROC_FS */
1643 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1646 struct sock *sk = sock->sk;
1647 struct sk_buff *skb;
1652 noblock = flags & MSG_DONTWAIT;
1653 flags &= ~MSG_DONTWAIT;
1654 skb = skb_recv_datagram(sk, flags, noblock, &error);
1658 if (skb->len < size)
1661 err = memcpy_to_msg(msg, skb->data, size);
1663 skb_free_datagram(sk, skb);
1667 sock_recv_ts_and_drops(msg, sk, skb);
1669 if (msg->msg_name) {
1670 __sockaddr_check_size(sizeof(struct sockaddr_can));
1671 msg->msg_namelen = sizeof(struct sockaddr_can);
1672 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1675 skb_free_datagram(sk, skb);
1680 static const struct proto_ops bcm_ops = {
1682 .release = bcm_release,
1683 .bind = sock_no_bind,
1684 .connect = bcm_connect,
1685 .socketpair = sock_no_socketpair,
1686 .accept = sock_no_accept,
1687 .getname = sock_no_getname,
1688 .poll = datagram_poll,
1689 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
1690 .listen = sock_no_listen,
1691 .shutdown = sock_no_shutdown,
1692 .setsockopt = sock_no_setsockopt,
1693 .getsockopt = sock_no_getsockopt,
1694 .sendmsg = bcm_sendmsg,
1695 .recvmsg = bcm_recvmsg,
1696 .mmap = sock_no_mmap,
1697 .sendpage = sock_no_sendpage,
1700 static struct proto bcm_proto __read_mostly = {
1702 .owner = THIS_MODULE,
1703 .obj_size = sizeof(struct bcm_sock),
1707 static const struct can_proto bcm_can_proto = {
1709 .protocol = CAN_BCM,
1714 static int canbcm_pernet_init(struct net *net)
1716 #if IS_ENABLED(CONFIG_PROC_FS)
1717 /* create /proc/net/can-bcm directory */
1718 net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1719 #endif /* CONFIG_PROC_FS */
1724 static void canbcm_pernet_exit(struct net *net)
1726 #if IS_ENABLED(CONFIG_PROC_FS)
1727 /* remove /proc/net/can-bcm directory */
1728 if (net->can.bcmproc_dir)
1729 remove_proc_entry("can-bcm", net->proc_net);
1730 #endif /* CONFIG_PROC_FS */
1733 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1734 .init = canbcm_pernet_init,
1735 .exit = canbcm_pernet_exit,
1738 static struct notifier_block canbcm_notifier = {
1739 .notifier_call = bcm_notifier
1742 static int __init bcm_module_init(void)
1746 pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1748 err = can_proto_register(&bcm_can_proto);
1750 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1754 register_pernet_subsys(&canbcm_pernet_ops);
1755 register_netdevice_notifier(&canbcm_notifier);
1759 static void __exit bcm_module_exit(void)
1761 can_proto_unregister(&bcm_can_proto);
1762 unregister_netdevice_notifier(&canbcm_notifier);
1763 unregister_pernet_subsys(&canbcm_pernet_ops);
1766 module_init(bcm_module_init);
1767 module_exit(bcm_module_exit);