2 * af_can.c - Protocol family CAN core module
3 * (used by different CAN protocol modules)
5 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of Volkswagen nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * Alternatively, provided that this notice is retained in full, this
21 * software may be distributed under the terms of the GNU General
22 * Public License ("GPL") version 2, in which case the provisions of the
23 * GPL apply INSTEAD OF those given above.
25 * The provided data structures and external interfaces from this code
26 * are not restricted to be used by modules with a GPL compatible license.
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
43 #include <linux/module.h>
44 #include <linux/stddef.h>
45 #include <linux/init.h>
46 #include <linux/kmod.h>
47 #include <linux/slab.h>
48 #include <linux/list.h>
49 #include <linux/spinlock.h>
50 #include <linux/rcupdate.h>
51 #include <linux/uaccess.h>
52 #include <linux/net.h>
53 #include <linux/netdevice.h>
54 #include <linux/socket.h>
55 #include <linux/if_ether.h>
56 #include <linux/if_arp.h>
57 #include <linux/skbuff.h>
58 #include <linux/can.h>
59 #include <linux/can/core.h>
60 #include <linux/can/skb.h>
61 #include <linux/ratelimit.h>
62 #include <net/net_namespace.h>
67 MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
68 MODULE_LICENSE("Dual BSD/GPL");
69 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
70 "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
72 MODULE_ALIAS_NETPROTO(PF_CAN);
74 static int stats_timer __read_mostly = 1;
75 module_param(stats_timer, int, S_IRUGO);
76 MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
78 /* receive filters subscribed for 'all' CAN devices */
79 struct dev_rcv_lists can_rx_alldev_list;
80 static DEFINE_SPINLOCK(can_rcvlists_lock);
82 static struct kmem_cache *rcv_cache __read_mostly;
84 /* table of registered CAN protocols */
85 static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
86 static DEFINE_MUTEX(proto_tab_lock);
88 struct timer_list can_stattimer; /* timer for statistics update */
89 struct s_stats can_stats; /* packet statistics */
90 struct s_pstats can_pstats; /* receive list statistics */
92 static atomic_t skbcounter = ATOMIC_INIT(0);
95 * af_can socket functions
98 int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
100 struct sock *sk = sock->sk;
105 return sock_get_timestamp(sk, (struct timeval __user *)arg);
111 EXPORT_SYMBOL(can_ioctl);
113 static void can_sock_destruct(struct sock *sk)
115 skb_queue_purge(&sk->sk_receive_queue);
116 skb_queue_purge(&sk->sk_error_queue);
119 static const struct can_proto *can_get_proto(int protocol)
121 const struct can_proto *cp;
124 cp = rcu_dereference(proto_tab[protocol]);
125 if (cp && !try_module_get(cp->prot->owner))
132 static inline void can_put_proto(const struct can_proto *cp)
134 module_put(cp->prot->owner);
137 static int can_create(struct net *net, struct socket *sock, int protocol,
141 const struct can_proto *cp;
144 sock->state = SS_UNCONNECTED;
146 if (protocol < 0 || protocol >= CAN_NPROTO)
149 if (!net_eq(net, &init_net))
150 return -EAFNOSUPPORT;
152 cp = can_get_proto(protocol);
154 #ifdef CONFIG_MODULES
156 /* try to load protocol module if kernel is modular */
158 err = request_module("can-proto-%d", protocol);
161 * In case of error we only print a message but don't
162 * return the error code immediately. Below we will
163 * return -EPROTONOSUPPORT
166 printk_ratelimited(KERN_ERR "can: request_module "
167 "(can-proto-%d) failed.\n", protocol);
169 cp = can_get_proto(protocol);
173 /* check for available protocol and correct usage */
176 return -EPROTONOSUPPORT;
178 if (cp->type != sock->type) {
185 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);
191 sock_init_data(sock, sk);
192 sk->sk_destruct = can_sock_destruct;
194 if (sk->sk_prot->init)
195 err = sk->sk_prot->init(sk);
198 /* release sk on errors */
213 * can_send - transmit a CAN frame (optional with local loopback)
214 * @skb: pointer to socket buffer with CAN frame in data section
215 * @loop: loopback for listeners on local CAN sockets (recommended default!)
217 * Due to the loopback this routine must not be called from hardirq context.
221 * -ENETDOWN when the selected interface is down
222 * -ENOBUFS on full driver queue (see net_xmit_errno())
223 * -ENOMEM when local loopback failed at calling skb_clone()
224 * -EPERM when trying to send on a non-CAN interface
225 * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
226 * -EINVAL when the skb->data does not contain a valid CAN frame
228 int can_send(struct sk_buff *skb, int loop)
230 struct sk_buff *newskb = NULL;
231 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
234 if (skb->len == CAN_MTU) {
235 skb->protocol = htons(ETH_P_CAN);
236 if (unlikely(cfd->len > CAN_MAX_DLEN))
238 } else if (skb->len == CANFD_MTU) {
239 skb->protocol = htons(ETH_P_CANFD);
240 if (unlikely(cfd->len > CANFD_MAX_DLEN))
246 * Make sure the CAN frame can pass the selected CAN netdevice.
247 * As structs can_frame and canfd_frame are similar, we can provide
248 * CAN FD frames to legacy CAN drivers as long as the length is <= 8
250 if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
255 if (unlikely(skb->dev->type != ARPHRD_CAN)) {
260 if (unlikely(!(skb->dev->flags & IFF_UP))) {
265 skb->ip_summed = CHECKSUM_UNNECESSARY;
267 skb_reset_mac_header(skb);
268 skb_reset_network_header(skb);
269 skb_reset_transport_header(skb);
272 /* local loopback of sent CAN frames */
274 /* indication for the CAN driver: do loopback */
275 skb->pkt_type = PACKET_LOOPBACK;
278 * The reference to the originating sock may be required
279 * by the receiving socket to check whether the frame is
280 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
281 * Therefore we have to ensure that skb->sk remains the
282 * reference to the originating sock by restoring skb->sk
283 * after each skb_clone() or skb_orphan() usage.
286 if (!(skb->dev->flags & IFF_ECHO)) {
288 * If the interface is not capable to do loopback
289 * itself, we do it here.
291 newskb = skb_clone(skb, GFP_ATOMIC);
297 can_skb_set_owner(newskb, skb->sk);
298 newskb->ip_summed = CHECKSUM_UNNECESSARY;
299 newskb->pkt_type = PACKET_BROADCAST;
302 /* indication for the CAN driver: no loopback required */
303 skb->pkt_type = PACKET_HOST;
306 /* send to netdevice */
307 err = dev_queue_xmit(skb);
309 err = net_xmit_errno(err);
319 /* update statistics */
320 can_stats.tx_frames++;
321 can_stats.tx_frames_delta++;
329 EXPORT_SYMBOL(can_send);
335 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
338 return &can_rx_alldev_list;
340 return (struct dev_rcv_lists *)dev->ml_priv;
344 * effhash - hash function for 29 bit CAN identifier reduction
345 * @can_id: 29 bit CAN identifier
348 * To reduce the linear traversal in one linked list of _single_ EFF CAN
349 * frame subscriptions the 29 bit identifier is mapped to 10 bits.
350 * (see CAN_EFF_RCV_HASH_BITS definition)
353 * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
355 static unsigned int effhash(canid_t can_id)
360 hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
361 hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
363 return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
367 * find_rcv_list - determine optimal filterlist inside device filter struct
368 * @can_id: pointer to CAN identifier of a given can_filter
369 * @mask: pointer to CAN mask of a given can_filter
370 * @d: pointer to the device filter struct
373 * Returns the optimal filterlist to reduce the filter handling in the
374 * receive path. This function is called by service functions that need
375 * to register or unregister a can_filter in the filter lists.
377 * A filter matches in general, when
379 * <received_can_id> & mask == can_id & mask
381 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
382 * relevant bits for the filter.
384 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
385 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
386 * frames there is a special filterlist and a special rx path filter handling.
389 * Pointer to optimal filterlist for the given can_id/mask pair.
390 * Constistency checked mask.
391 * Reduced can_id to have a preprocessed filter compare value.
393 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
394 struct dev_rcv_lists *d)
396 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
398 /* filter for error message frames in extra filterlist */
399 if (*mask & CAN_ERR_FLAG) {
400 /* clear CAN_ERR_FLAG in filter entry */
401 *mask &= CAN_ERR_MASK;
402 return &d->rx[RX_ERR];
405 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
407 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
409 /* ensure valid values in can_mask for 'SFF only' frame filtering */
410 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
411 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
413 /* reduce condition testing at receive time */
416 /* inverse can_id/can_mask filter */
418 return &d->rx[RX_INV];
420 /* mask == 0 => no condition testing at receive time */
422 return &d->rx[RX_ALL];
424 /* extra filterlists for the subscription of a single non-RTR can_id */
425 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
426 !(*can_id & CAN_RTR_FLAG)) {
428 if (*can_id & CAN_EFF_FLAG) {
429 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
430 return &d->rx_eff[effhash(*can_id)];
432 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
433 return &d->rx_sff[*can_id];
437 /* default: filter via can_id/can_mask */
438 return &d->rx[RX_FIL];
442 * can_rx_register - subscribe CAN frames from a specific interface
443 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
444 * @can_id: CAN identifier (see description)
445 * @mask: CAN mask (see description)
446 * @func: callback function on filter match
447 * @data: returned parameter for callback function
448 * @ident: string for calling module identification
449 * @sk: socket pointer (might be NULL)
452 * Invokes the callback function with the received sk_buff and the given
453 * parameter 'data' on a matching receive filter. A filter matches, when
455 * <received_can_id> & mask == can_id & mask
457 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
458 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
460 * The provided pointer to the sk_buff is guaranteed to be valid as long as
461 * the callback function is running. The callback function must *not* free
462 * the given sk_buff while processing it's task. When the given sk_buff is
463 * needed after the end of the callback function it must be cloned inside
464 * the callback function with skb_clone().
468 * -ENOMEM on missing cache mem to create subscription entry
469 * -ENODEV unknown device
471 int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
472 void (*func)(struct sk_buff *, void *), void *data,
473 char *ident, struct sock *sk)
476 struct hlist_head *rl;
477 struct dev_rcv_lists *d;
480 /* insert new receiver (dev,canid,mask) -> (func,data) */
482 if (dev && dev->type != ARPHRD_CAN)
485 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
489 spin_lock(&can_rcvlists_lock);
491 d = find_dev_rcv_lists(dev);
493 rl = find_rcv_list(&can_id, &mask, d);
503 hlist_add_head_rcu(&r->list, rl);
506 can_pstats.rcv_entries++;
507 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
508 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
510 kmem_cache_free(rcv_cache, r);
514 spin_unlock(&can_rcvlists_lock);
518 EXPORT_SYMBOL(can_rx_register);
521 * can_rx_delete_receiver - rcu callback for single receiver entry removal
523 static void can_rx_delete_receiver(struct rcu_head *rp)
525 struct receiver *r = container_of(rp, struct receiver, rcu);
526 struct sock *sk = r->sk;
528 kmem_cache_free(rcv_cache, r);
534 * can_rx_unregister - unsubscribe CAN frames from a specific interface
535 * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
536 * @can_id: CAN identifier
538 * @func: callback function on filter match
539 * @data: returned parameter for callback function
542 * Removes subscription entry depending on given (subscription) values.
544 void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
545 void (*func)(struct sk_buff *, void *), void *data)
547 struct receiver *r = NULL;
548 struct hlist_head *rl;
549 struct dev_rcv_lists *d;
551 if (dev && dev->type != ARPHRD_CAN)
554 spin_lock(&can_rcvlists_lock);
556 d = find_dev_rcv_lists(dev);
558 pr_err("BUG: receive list not found for "
559 "dev %s, id %03X, mask %03X\n",
560 DNAME(dev), can_id, mask);
564 rl = find_rcv_list(&can_id, &mask, d);
567 * Search the receiver list for the item to delete. This should
568 * exist, since no receiver may be unregistered that hasn't
569 * been registered before.
572 hlist_for_each_entry_rcu(r, rl, list) {
573 if (r->can_id == can_id && r->mask == mask &&
574 r->func == func && r->data == data)
579 * Check for bugs in CAN protocol implementations using af_can.c:
580 * 'r' will be NULL if no matching list item was found for removal.
584 WARN(1, "BUG: receive list entry not found for dev %s, "
585 "id %03X, mask %03X\n", DNAME(dev), can_id, mask);
589 hlist_del_rcu(&r->list);
592 if (can_pstats.rcv_entries > 0)
593 can_pstats.rcv_entries--;
595 /* remove device structure requested by NETDEV_UNREGISTER */
596 if (d->remove_on_zero_entries && !d->entries) {
602 spin_unlock(&can_rcvlists_lock);
604 /* schedule the receiver item for deletion */
608 call_rcu(&r->rcu, can_rx_delete_receiver);
611 EXPORT_SYMBOL(can_rx_unregister);
613 static inline void deliver(struct sk_buff *skb, struct receiver *r)
615 r->func(skb, r->data);
619 static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
623 struct can_frame *cf = (struct can_frame *)skb->data;
624 canid_t can_id = cf->can_id;
629 if (can_id & CAN_ERR_FLAG) {
630 /* check for error message frame entries only */
631 hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) {
632 if (can_id & r->mask) {
640 /* check for unfiltered entries */
641 hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) {
646 /* check for can_id/mask entries */
647 hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) {
648 if ((can_id & r->mask) == r->can_id) {
654 /* check for inverted can_id/mask entries */
655 hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) {
656 if ((can_id & r->mask) != r->can_id) {
662 /* check filterlists for single non-RTR can_ids */
663 if (can_id & CAN_RTR_FLAG)
666 if (can_id & CAN_EFF_FLAG) {
667 hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
668 if (r->can_id == can_id) {
674 can_id &= CAN_SFF_MASK;
675 hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) {
684 static void can_receive(struct sk_buff *skb, struct net_device *dev)
686 struct dev_rcv_lists *d;
689 /* update statistics */
690 can_stats.rx_frames++;
691 can_stats.rx_frames_delta++;
693 /* create non-zero unique skb identifier together with *skb */
694 while (!(can_skb_prv(skb)->skbcnt))
695 can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);
699 /* deliver the packet to sockets listening on all devices */
700 matches = can_rcv_filter(&can_rx_alldev_list, skb);
702 /* find receive list for this device */
703 d = find_dev_rcv_lists(dev);
705 matches += can_rcv_filter(d, skb);
709 /* consume the skbuff allocated by the netdevice driver */
714 can_stats.matches_delta++;
718 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
719 struct packet_type *pt, struct net_device *orig_dev)
721 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
723 if (unlikely(!net_eq(dev_net(dev), &init_net)))
726 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU ||
727 cfd->len > CAN_MAX_DLEN)) {
728 pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n",
729 dev->type, skb->len, cfd->len);
733 can_receive(skb, dev);
734 return NET_RX_SUCCESS;
741 static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
742 struct packet_type *pt, struct net_device *orig_dev)
744 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
746 if (unlikely(!net_eq(dev_net(dev), &init_net)))
749 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU ||
750 cfd->len > CANFD_MAX_DLEN)) {
751 pr_warn_once("PF_CAN: dropped non conform CAN FD skbuf: dev type %d, len %d, datalen %d\n",
752 dev->type, skb->len, cfd->len);
756 can_receive(skb, dev);
757 return NET_RX_SUCCESS;
765 * af_can protocol functions
769 * can_proto_register - register CAN transport protocol
770 * @cp: pointer to CAN protocol structure
774 * -EINVAL invalid (out of range) protocol number
775 * -EBUSY protocol already in use
776 * -ENOBUF if proto_register() fails
778 int can_proto_register(const struct can_proto *cp)
780 int proto = cp->protocol;
783 if (proto < 0 || proto >= CAN_NPROTO) {
784 pr_err("can: protocol number %d out of range\n", proto);
788 err = proto_register(cp->prot, 0);
792 mutex_lock(&proto_tab_lock);
794 if (proto_tab[proto]) {
795 pr_err("can: protocol %d already registered\n", proto);
798 RCU_INIT_POINTER(proto_tab[proto], cp);
800 mutex_unlock(&proto_tab_lock);
803 proto_unregister(cp->prot);
807 EXPORT_SYMBOL(can_proto_register);
810 * can_proto_unregister - unregister CAN transport protocol
811 * @cp: pointer to CAN protocol structure
813 void can_proto_unregister(const struct can_proto *cp)
815 int proto = cp->protocol;
817 mutex_lock(&proto_tab_lock);
818 BUG_ON(proto_tab[proto] != cp);
819 RCU_INIT_POINTER(proto_tab[proto], NULL);
820 mutex_unlock(&proto_tab_lock);
824 proto_unregister(cp->prot);
826 EXPORT_SYMBOL(can_proto_unregister);
829 * af_can notifier to create/remove CAN netdevice specific structs
831 static int can_notifier(struct notifier_block *nb, unsigned long msg,
834 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
835 struct dev_rcv_lists *d;
837 if (!net_eq(dev_net(dev), &init_net))
840 if (dev->type != ARPHRD_CAN)
845 case NETDEV_REGISTER:
847 /* create new dev_rcv_lists for this device */
848 d = kzalloc(sizeof(*d), GFP_KERNEL);
851 BUG_ON(dev->ml_priv);
856 case NETDEV_UNREGISTER:
857 spin_lock(&can_rcvlists_lock);
862 d->remove_on_zero_entries = 1;
868 pr_err("can: notifier: receive list not found for dev "
871 spin_unlock(&can_rcvlists_lock);
880 * af_can module init/exit functions
883 static struct packet_type can_packet __read_mostly = {
884 .type = cpu_to_be16(ETH_P_CAN),
888 static struct packet_type canfd_packet __read_mostly = {
889 .type = cpu_to_be16(ETH_P_CANFD),
893 static const struct net_proto_family can_family_ops = {
895 .create = can_create,
896 .owner = THIS_MODULE,
899 /* notifier block for netdevice event */
900 static struct notifier_block can_netdev_notifier __read_mostly = {
901 .notifier_call = can_notifier,
904 static __init int can_init(void)
906 /* check for correct padding to be able to use the structs similarly */
907 BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
908 offsetof(struct canfd_frame, len) ||
909 offsetof(struct can_frame, data) !=
910 offsetof(struct canfd_frame, data));
912 pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");
914 memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
916 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
922 /* the statistics are updated every second (timer triggered) */
923 setup_timer(&can_stattimer, can_stat_update, 0);
924 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
926 can_stattimer.function = NULL;
930 /* protocol register */
931 sock_register(&can_family_ops);
932 register_netdevice_notifier(&can_netdev_notifier);
933 dev_add_pack(&can_packet);
934 dev_add_pack(&canfd_packet);
939 static __exit void can_exit(void)
941 struct net_device *dev;
944 del_timer_sync(&can_stattimer);
948 /* protocol unregister */
949 dev_remove_pack(&canfd_packet);
950 dev_remove_pack(&can_packet);
951 unregister_netdevice_notifier(&can_netdev_notifier);
952 sock_unregister(PF_CAN);
954 /* remove created dev_rcv_lists from still registered CAN devices */
956 for_each_netdev_rcu(&init_net, dev) {
957 if (dev->type == ARPHRD_CAN && dev->ml_priv) {
959 struct dev_rcv_lists *d = dev->ml_priv;
968 rcu_barrier(); /* Wait for completion of call_rcu()'s */
970 kmem_cache_destroy(rcv_cache);
973 module_init(can_init);
974 module_exit(can_exit);