2 * af_can.c - Protocol family CAN core module
3 * (used by different CAN protocol modules)
5 * Copyright (c) 2002-2017 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, 0444);
76 MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
78 static struct kmem_cache *rcv_cache __read_mostly;
80 /* table of registered CAN protocols */
81 static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly;
82 static DEFINE_MUTEX(proto_tab_lock);
84 static atomic_t skbcounter = ATOMIC_INIT(0);
87 * af_can socket functions
90 int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
97 EXPORT_SYMBOL(can_ioctl);
99 static void can_sock_destruct(struct sock *sk)
101 skb_queue_purge(&sk->sk_receive_queue);
104 static const struct can_proto *can_get_proto(int protocol)
106 const struct can_proto *cp;
109 cp = rcu_dereference(proto_tab[protocol]);
110 if (cp && !try_module_get(cp->prot->owner))
117 static inline void can_put_proto(const struct can_proto *cp)
119 module_put(cp->prot->owner);
122 static int can_create(struct net *net, struct socket *sock, int protocol,
126 const struct can_proto *cp;
129 sock->state = SS_UNCONNECTED;
131 if (protocol < 0 || protocol >= CAN_NPROTO)
134 cp = can_get_proto(protocol);
136 #ifdef CONFIG_MODULES
138 /* try to load protocol module if kernel is modular */
140 err = request_module("can-proto-%d", protocol);
143 * In case of error we only print a message but don't
144 * return the error code immediately. Below we will
145 * return -EPROTONOSUPPORT
148 printk_ratelimited(KERN_ERR "can: request_module "
149 "(can-proto-%d) failed.\n", protocol);
151 cp = can_get_proto(protocol);
155 /* check for available protocol and correct usage */
158 return -EPROTONOSUPPORT;
160 if (cp->type != sock->type) {
167 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);
173 sock_init_data(sock, sk);
174 sk->sk_destruct = can_sock_destruct;
176 if (sk->sk_prot->init)
177 err = sk->sk_prot->init(sk);
180 /* release sk on errors */
195 * can_send - transmit a CAN frame (optional with local loopback)
196 * @skb: pointer to socket buffer with CAN frame in data section
197 * @loop: loopback for listeners on local CAN sockets (recommended default!)
199 * Due to the loopback this routine must not be called from hardirq context.
203 * -ENETDOWN when the selected interface is down
204 * -ENOBUFS on full driver queue (see net_xmit_errno())
205 * -ENOMEM when local loopback failed at calling skb_clone()
206 * -EPERM when trying to send on a non-CAN interface
207 * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
208 * -EINVAL when the skb->data does not contain a valid CAN frame
210 int can_send(struct sk_buff *skb, int loop)
212 struct sk_buff *newskb = NULL;
213 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
214 struct s_stats *can_stats = dev_net(skb->dev)->can.can_stats;
217 if (skb->len == CAN_MTU) {
218 skb->protocol = htons(ETH_P_CAN);
219 if (unlikely(cfd->len > CAN_MAX_DLEN))
221 } else if (skb->len == CANFD_MTU) {
222 skb->protocol = htons(ETH_P_CANFD);
223 if (unlikely(cfd->len > CANFD_MAX_DLEN))
229 * Make sure the CAN frame can pass the selected CAN netdevice.
230 * As structs can_frame and canfd_frame are similar, we can provide
231 * CAN FD frames to legacy CAN drivers as long as the length is <= 8
233 if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
238 if (unlikely(skb->dev->type != ARPHRD_CAN)) {
243 if (unlikely(!(skb->dev->flags & IFF_UP))) {
248 skb->ip_summed = CHECKSUM_UNNECESSARY;
250 skb_reset_mac_header(skb);
251 skb_reset_network_header(skb);
252 skb_reset_transport_header(skb);
255 /* local loopback of sent CAN frames */
257 /* indication for the CAN driver: do loopback */
258 skb->pkt_type = PACKET_LOOPBACK;
261 * The reference to the originating sock may be required
262 * by the receiving socket to check whether the frame is
263 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
264 * Therefore we have to ensure that skb->sk remains the
265 * reference to the originating sock by restoring skb->sk
266 * after each skb_clone() or skb_orphan() usage.
269 if (!(skb->dev->flags & IFF_ECHO)) {
271 * If the interface is not capable to do loopback
272 * itself, we do it here.
274 newskb = skb_clone(skb, GFP_ATOMIC);
280 can_skb_set_owner(newskb, skb->sk);
281 newskb->ip_summed = CHECKSUM_UNNECESSARY;
282 newskb->pkt_type = PACKET_BROADCAST;
285 /* indication for the CAN driver: no loopback required */
286 skb->pkt_type = PACKET_HOST;
289 /* send to netdevice */
290 err = dev_queue_xmit(skb);
292 err = net_xmit_errno(err);
302 /* update statistics */
303 can_stats->tx_frames++;
304 can_stats->tx_frames_delta++;
312 EXPORT_SYMBOL(can_send);
318 static struct can_dev_rcv_lists *find_dev_rcv_lists(struct net *net,
319 struct net_device *dev)
322 return net->can.can_rx_alldev_list;
324 return (struct can_dev_rcv_lists *)dev->ml_priv;
328 * effhash - hash function for 29 bit CAN identifier reduction
329 * @can_id: 29 bit CAN identifier
332 * To reduce the linear traversal in one linked list of _single_ EFF CAN
333 * frame subscriptions the 29 bit identifier is mapped to 10 bits.
334 * (see CAN_EFF_RCV_HASH_BITS definition)
337 * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
339 static unsigned int effhash(canid_t can_id)
344 hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
345 hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
347 return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
351 * find_rcv_list - determine optimal filterlist inside device filter struct
352 * @can_id: pointer to CAN identifier of a given can_filter
353 * @mask: pointer to CAN mask of a given can_filter
354 * @d: pointer to the device filter struct
357 * Returns the optimal filterlist to reduce the filter handling in the
358 * receive path. This function is called by service functions that need
359 * to register or unregister a can_filter in the filter lists.
361 * A filter matches in general, when
363 * <received_can_id> & mask == can_id & mask
365 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
366 * relevant bits for the filter.
368 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
369 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
370 * frames there is a special filterlist and a special rx path filter handling.
373 * Pointer to optimal filterlist for the given can_id/mask pair.
374 * Constistency checked mask.
375 * Reduced can_id to have a preprocessed filter compare value.
377 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
378 struct can_dev_rcv_lists *d)
380 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
382 /* filter for error message frames in extra filterlist */
383 if (*mask & CAN_ERR_FLAG) {
384 /* clear CAN_ERR_FLAG in filter entry */
385 *mask &= CAN_ERR_MASK;
386 return &d->rx[RX_ERR];
389 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
391 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
393 /* ensure valid values in can_mask for 'SFF only' frame filtering */
394 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
395 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
397 /* reduce condition testing at receive time */
400 /* inverse can_id/can_mask filter */
402 return &d->rx[RX_INV];
404 /* mask == 0 => no condition testing at receive time */
406 return &d->rx[RX_ALL];
408 /* extra filterlists for the subscription of a single non-RTR can_id */
409 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
410 !(*can_id & CAN_RTR_FLAG)) {
412 if (*can_id & CAN_EFF_FLAG) {
413 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
414 return &d->rx_eff[effhash(*can_id)];
416 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
417 return &d->rx_sff[*can_id];
421 /* default: filter via can_id/can_mask */
422 return &d->rx[RX_FIL];
426 * can_rx_register - subscribe CAN frames from a specific interface
427 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
428 * @can_id: CAN identifier (see description)
429 * @mask: CAN mask (see description)
430 * @func: callback function on filter match
431 * @data: returned parameter for callback function
432 * @ident: string for calling module identification
433 * @sk: socket pointer (might be NULL)
436 * Invokes the callback function with the received sk_buff and the given
437 * parameter 'data' on a matching receive filter. A filter matches, when
439 * <received_can_id> & mask == can_id & mask
441 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
442 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
444 * The provided pointer to the sk_buff is guaranteed to be valid as long as
445 * the callback function is running. The callback function must *not* free
446 * the given sk_buff while processing it's task. When the given sk_buff is
447 * needed after the end of the callback function it must be cloned inside
448 * the callback function with skb_clone().
452 * -ENOMEM on missing cache mem to create subscription entry
453 * -ENODEV unknown device
455 int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
456 canid_t mask, void (*func)(struct sk_buff *, void *),
457 void *data, char *ident, struct sock *sk)
460 struct hlist_head *rl;
461 struct can_dev_rcv_lists *d;
462 struct s_pstats *can_pstats = net->can.can_pstats;
465 /* insert new receiver (dev,canid,mask) -> (func,data) */
467 if (dev && dev->type != ARPHRD_CAN)
470 if (dev && !net_eq(net, dev_net(dev)))
473 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
477 spin_lock(&net->can.can_rcvlists_lock);
479 d = find_dev_rcv_lists(net, dev);
481 rl = find_rcv_list(&can_id, &mask, d);
491 hlist_add_head_rcu(&r->list, rl);
494 can_pstats->rcv_entries++;
495 if (can_pstats->rcv_entries_max < can_pstats->rcv_entries)
496 can_pstats->rcv_entries_max = can_pstats->rcv_entries;
498 kmem_cache_free(rcv_cache, r);
502 spin_unlock(&net->can.can_rcvlists_lock);
506 EXPORT_SYMBOL(can_rx_register);
509 * can_rx_delete_receiver - rcu callback for single receiver entry removal
511 static void can_rx_delete_receiver(struct rcu_head *rp)
513 struct receiver *r = container_of(rp, struct receiver, rcu);
514 struct sock *sk = r->sk;
516 kmem_cache_free(rcv_cache, r);
522 * can_rx_unregister - unsubscribe CAN frames from a specific interface
523 * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
524 * @can_id: CAN identifier
526 * @func: callback function on filter match
527 * @data: returned parameter for callback function
530 * Removes subscription entry depending on given (subscription) values.
532 void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
533 canid_t mask, void (*func)(struct sk_buff *, void *),
536 struct receiver *r = NULL;
537 struct hlist_head *rl;
538 struct s_pstats *can_pstats = net->can.can_pstats;
539 struct can_dev_rcv_lists *d;
541 if (dev && dev->type != ARPHRD_CAN)
544 if (dev && !net_eq(net, dev_net(dev)))
547 spin_lock(&net->can.can_rcvlists_lock);
549 d = find_dev_rcv_lists(net, dev);
551 pr_err("BUG: receive list not found for "
552 "dev %s, id %03X, mask %03X\n",
553 DNAME(dev), can_id, mask);
557 rl = find_rcv_list(&can_id, &mask, d);
560 * Search the receiver list for the item to delete. This should
561 * exist, since no receiver may be unregistered that hasn't
562 * been registered before.
565 hlist_for_each_entry_rcu(r, rl, list) {
566 if (r->can_id == can_id && r->mask == mask &&
567 r->func == func && r->data == data)
572 * Check for bugs in CAN protocol implementations using af_can.c:
573 * 'r' will be NULL if no matching list item was found for removal.
577 WARN(1, "BUG: receive list entry not found for dev %s, "
578 "id %03X, mask %03X\n", DNAME(dev), can_id, mask);
582 hlist_del_rcu(&r->list);
585 if (can_pstats->rcv_entries > 0)
586 can_pstats->rcv_entries--;
588 /* remove device structure requested by NETDEV_UNREGISTER */
589 if (d->remove_on_zero_entries && !d->entries) {
595 spin_unlock(&net->can.can_rcvlists_lock);
597 /* schedule the receiver item for deletion */
601 call_rcu(&r->rcu, can_rx_delete_receiver);
604 EXPORT_SYMBOL(can_rx_unregister);
606 static inline void deliver(struct sk_buff *skb, struct receiver *r)
608 r->func(skb, r->data);
612 static int can_rcv_filter(struct can_dev_rcv_lists *d, struct sk_buff *skb)
616 struct can_frame *cf = (struct can_frame *)skb->data;
617 canid_t can_id = cf->can_id;
622 if (can_id & CAN_ERR_FLAG) {
623 /* check for error message frame entries only */
624 hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) {
625 if (can_id & r->mask) {
633 /* check for unfiltered entries */
634 hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) {
639 /* check for can_id/mask entries */
640 hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) {
641 if ((can_id & r->mask) == r->can_id) {
647 /* check for inverted can_id/mask entries */
648 hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) {
649 if ((can_id & r->mask) != r->can_id) {
655 /* check filterlists for single non-RTR can_ids */
656 if (can_id & CAN_RTR_FLAG)
659 if (can_id & CAN_EFF_FLAG) {
660 hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
661 if (r->can_id == can_id) {
667 can_id &= CAN_SFF_MASK;
668 hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) {
677 static void can_receive(struct sk_buff *skb, struct net_device *dev)
679 struct can_dev_rcv_lists *d;
680 struct net *net = dev_net(dev);
681 struct s_stats *can_stats = net->can.can_stats;
684 /* update statistics */
685 can_stats->rx_frames++;
686 can_stats->rx_frames_delta++;
688 /* create non-zero unique skb identifier together with *skb */
689 while (!(can_skb_prv(skb)->skbcnt))
690 can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);
694 /* deliver the packet to sockets listening on all devices */
695 matches = can_rcv_filter(net->can.can_rx_alldev_list, skb);
697 /* find receive list for this device */
698 d = find_dev_rcv_lists(net, dev);
700 matches += can_rcv_filter(d, skb);
704 /* consume the skbuff allocated by the netdevice driver */
708 can_stats->matches++;
709 can_stats->matches_delta++;
713 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
714 struct packet_type *pt, struct net_device *orig_dev)
716 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
718 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU ||
719 cfd->len > CAN_MAX_DLEN)) {
720 pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n",
721 dev->type, skb->len, cfd->len);
726 can_receive(skb, dev);
727 return NET_RX_SUCCESS;
730 static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
731 struct packet_type *pt, struct net_device *orig_dev)
733 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
735 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU ||
736 cfd->len > CANFD_MAX_DLEN)) {
737 pr_warn_once("PF_CAN: dropped non conform CAN FD skbuf: dev type %d, len %d, datalen %d\n",
738 dev->type, skb->len, cfd->len);
743 can_receive(skb, dev);
744 return NET_RX_SUCCESS;
748 * af_can protocol functions
752 * can_proto_register - register CAN transport protocol
753 * @cp: pointer to CAN protocol structure
757 * -EINVAL invalid (out of range) protocol number
758 * -EBUSY protocol already in use
759 * -ENOBUF if proto_register() fails
761 int can_proto_register(const struct can_proto *cp)
763 int proto = cp->protocol;
766 if (proto < 0 || proto >= CAN_NPROTO) {
767 pr_err("can: protocol number %d out of range\n", proto);
771 err = proto_register(cp->prot, 0);
775 mutex_lock(&proto_tab_lock);
777 if (rcu_access_pointer(proto_tab[proto])) {
778 pr_err("can: protocol %d already registered\n", proto);
781 RCU_INIT_POINTER(proto_tab[proto], cp);
783 mutex_unlock(&proto_tab_lock);
786 proto_unregister(cp->prot);
790 EXPORT_SYMBOL(can_proto_register);
793 * can_proto_unregister - unregister CAN transport protocol
794 * @cp: pointer to CAN protocol structure
796 void can_proto_unregister(const struct can_proto *cp)
798 int proto = cp->protocol;
800 mutex_lock(&proto_tab_lock);
801 BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp);
802 RCU_INIT_POINTER(proto_tab[proto], NULL);
803 mutex_unlock(&proto_tab_lock);
807 proto_unregister(cp->prot);
809 EXPORT_SYMBOL(can_proto_unregister);
812 * af_can notifier to create/remove CAN netdevice specific structs
814 static int can_notifier(struct notifier_block *nb, unsigned long msg,
817 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
818 struct can_dev_rcv_lists *d;
820 if (dev->type != ARPHRD_CAN)
825 case NETDEV_REGISTER:
827 /* create new dev_rcv_lists for this device */
828 d = kzalloc(sizeof(*d), GFP_KERNEL);
831 BUG_ON(dev->ml_priv);
836 case NETDEV_UNREGISTER:
837 spin_lock(&dev_net(dev)->can.can_rcvlists_lock);
842 d->remove_on_zero_entries = 1;
848 pr_err("can: notifier: receive list not found for dev "
851 spin_unlock(&dev_net(dev)->can.can_rcvlists_lock);
859 static int can_pernet_init(struct net *net)
861 spin_lock_init(&net->can.can_rcvlists_lock);
862 net->can.can_rx_alldev_list =
863 kzalloc(sizeof(struct can_dev_rcv_lists), GFP_KERNEL);
864 if (!net->can.can_rx_alldev_list)
866 net->can.can_stats = kzalloc(sizeof(struct s_stats), GFP_KERNEL);
867 if (!net->can.can_stats)
868 goto out_free_alldev_list;
869 net->can.can_pstats = kzalloc(sizeof(struct s_pstats), GFP_KERNEL);
870 if (!net->can.can_pstats)
871 goto out_free_can_stats;
873 if (IS_ENABLED(CONFIG_PROC_FS)) {
874 /* the statistics are updated every second (timer triggered) */
876 timer_setup(&net->can.can_stattimer, can_stat_update,
878 mod_timer(&net->can.can_stattimer,
879 round_jiffies(jiffies + HZ));
881 net->can.can_stats->jiffies_init = jiffies;
888 kfree(net->can.can_stats);
889 out_free_alldev_list:
890 kfree(net->can.can_rx_alldev_list);
895 static void can_pernet_exit(struct net *net)
897 struct net_device *dev;
899 if (IS_ENABLED(CONFIG_PROC_FS)) {
900 can_remove_proc(net);
902 del_timer_sync(&net->can.can_stattimer);
905 /* remove created dev_rcv_lists from still registered CAN devices */
907 for_each_netdev_rcu(net, dev) {
908 if (dev->type == ARPHRD_CAN && dev->ml_priv) {
909 struct can_dev_rcv_lists *d = dev->ml_priv;
918 kfree(net->can.can_rx_alldev_list);
919 kfree(net->can.can_stats);
920 kfree(net->can.can_pstats);
924 * af_can module init/exit functions
927 static struct packet_type can_packet __read_mostly = {
928 .type = cpu_to_be16(ETH_P_CAN),
932 static struct packet_type canfd_packet __read_mostly = {
933 .type = cpu_to_be16(ETH_P_CANFD),
937 static const struct net_proto_family can_family_ops = {
939 .create = can_create,
940 .owner = THIS_MODULE,
943 /* notifier block for netdevice event */
944 static struct notifier_block can_netdev_notifier __read_mostly = {
945 .notifier_call = can_notifier,
948 static struct pernet_operations can_pernet_ops __read_mostly = {
949 .init = can_pernet_init,
950 .exit = can_pernet_exit,
953 static __init int can_init(void)
955 /* check for correct padding to be able to use the structs similarly */
956 BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
957 offsetof(struct canfd_frame, len) ||
958 offsetof(struct can_frame, data) !=
959 offsetof(struct canfd_frame, data));
961 pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");
963 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
968 register_pernet_subsys(&can_pernet_ops);
970 /* protocol register */
971 sock_register(&can_family_ops);
972 register_netdevice_notifier(&can_netdev_notifier);
973 dev_add_pack(&can_packet);
974 dev_add_pack(&canfd_packet);
979 static __exit void can_exit(void)
981 /* protocol unregister */
982 dev_remove_pack(&canfd_packet);
983 dev_remove_pack(&can_packet);
984 unregister_netdevice_notifier(&can_netdev_notifier);
985 sock_unregister(PF_CAN);
987 unregister_pernet_subsys(&can_pernet_ops);
989 rcu_barrier(); /* Wait for completion of call_rcu()'s */
991 kmem_cache_destroy(rcv_cache);
994 module_init(can_init);
995 module_exit(can_exit);