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)
92 struct sock *sk = sock->sk;
97 return sock_get_timestamp(sk, (struct timeval __user *)arg);
103 EXPORT_SYMBOL(can_ioctl);
105 static void can_sock_destruct(struct sock *sk)
107 skb_queue_purge(&sk->sk_receive_queue);
108 skb_queue_purge(&sk->sk_error_queue);
111 static const struct can_proto *can_get_proto(int protocol)
113 const struct can_proto *cp;
116 cp = rcu_dereference(proto_tab[protocol]);
117 if (cp && !try_module_get(cp->prot->owner))
124 static inline void can_put_proto(const struct can_proto *cp)
126 module_put(cp->prot->owner);
129 static int can_create(struct net *net, struct socket *sock, int protocol,
133 const struct can_proto *cp;
136 sock->state = SS_UNCONNECTED;
138 if (protocol < 0 || protocol >= CAN_NPROTO)
141 cp = can_get_proto(protocol);
143 #ifdef CONFIG_MODULES
145 /* try to load protocol module if kernel is modular */
147 err = request_module("can-proto-%d", protocol);
150 * In case of error we only print a message but don't
151 * return the error code immediately. Below we will
152 * return -EPROTONOSUPPORT
155 printk_ratelimited(KERN_ERR "can: request_module "
156 "(can-proto-%d) failed.\n", protocol);
158 cp = can_get_proto(protocol);
162 /* check for available protocol and correct usage */
165 return -EPROTONOSUPPORT;
167 if (cp->type != sock->type) {
174 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);
180 sock_init_data(sock, sk);
181 sk->sk_destruct = can_sock_destruct;
183 if (sk->sk_prot->init)
184 err = sk->sk_prot->init(sk);
187 /* release sk on errors */
202 * can_send - transmit a CAN frame (optional with local loopback)
203 * @skb: pointer to socket buffer with CAN frame in data section
204 * @loop: loopback for listeners on local CAN sockets (recommended default!)
206 * Due to the loopback this routine must not be called from hardirq context.
210 * -ENETDOWN when the selected interface is down
211 * -ENOBUFS on full driver queue (see net_xmit_errno())
212 * -ENOMEM when local loopback failed at calling skb_clone()
213 * -EPERM when trying to send on a non-CAN interface
214 * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
215 * -EINVAL when the skb->data does not contain a valid CAN frame
217 int can_send(struct sk_buff *skb, int loop)
219 struct sk_buff *newskb = NULL;
220 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
221 struct s_stats *can_stats = dev_net(skb->dev)->can.can_stats;
224 if (skb->len == CAN_MTU) {
225 skb->protocol = htons(ETH_P_CAN);
226 if (unlikely(cfd->len > CAN_MAX_DLEN))
228 } else if (skb->len == CANFD_MTU) {
229 skb->protocol = htons(ETH_P_CANFD);
230 if (unlikely(cfd->len > CANFD_MAX_DLEN))
236 * Make sure the CAN frame can pass the selected CAN netdevice.
237 * As structs can_frame and canfd_frame are similar, we can provide
238 * CAN FD frames to legacy CAN drivers as long as the length is <= 8
240 if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
245 if (unlikely(skb->dev->type != ARPHRD_CAN)) {
250 if (unlikely(!(skb->dev->flags & IFF_UP))) {
255 skb->ip_summed = CHECKSUM_UNNECESSARY;
257 skb_reset_mac_header(skb);
258 skb_reset_network_header(skb);
259 skb_reset_transport_header(skb);
262 /* local loopback of sent CAN frames */
264 /* indication for the CAN driver: do loopback */
265 skb->pkt_type = PACKET_LOOPBACK;
268 * The reference to the originating sock may be required
269 * by the receiving socket to check whether the frame is
270 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
271 * Therefore we have to ensure that skb->sk remains the
272 * reference to the originating sock by restoring skb->sk
273 * after each skb_clone() or skb_orphan() usage.
276 if (!(skb->dev->flags & IFF_ECHO)) {
278 * If the interface is not capable to do loopback
279 * itself, we do it here.
281 newskb = skb_clone(skb, GFP_ATOMIC);
287 can_skb_set_owner(newskb, skb->sk);
288 newskb->ip_summed = CHECKSUM_UNNECESSARY;
289 newskb->pkt_type = PACKET_BROADCAST;
292 /* indication for the CAN driver: no loopback required */
293 skb->pkt_type = PACKET_HOST;
296 /* send to netdevice */
297 err = dev_queue_xmit(skb);
299 err = net_xmit_errno(err);
309 /* update statistics */
310 can_stats->tx_frames++;
311 can_stats->tx_frames_delta++;
319 EXPORT_SYMBOL(can_send);
325 static struct can_dev_rcv_lists *find_dev_rcv_lists(struct net *net,
326 struct net_device *dev)
329 return net->can.can_rx_alldev_list;
331 return (struct can_dev_rcv_lists *)dev->ml_priv;
335 * effhash - hash function for 29 bit CAN identifier reduction
336 * @can_id: 29 bit CAN identifier
339 * To reduce the linear traversal in one linked list of _single_ EFF CAN
340 * frame subscriptions the 29 bit identifier is mapped to 10 bits.
341 * (see CAN_EFF_RCV_HASH_BITS definition)
344 * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
346 static unsigned int effhash(canid_t can_id)
351 hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
352 hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
354 return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
358 * find_rcv_list - determine optimal filterlist inside device filter struct
359 * @can_id: pointer to CAN identifier of a given can_filter
360 * @mask: pointer to CAN mask of a given can_filter
361 * @d: pointer to the device filter struct
364 * Returns the optimal filterlist to reduce the filter handling in the
365 * receive path. This function is called by service functions that need
366 * to register or unregister a can_filter in the filter lists.
368 * A filter matches in general, when
370 * <received_can_id> & mask == can_id & mask
372 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
373 * relevant bits for the filter.
375 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
376 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
377 * frames there is a special filterlist and a special rx path filter handling.
380 * Pointer to optimal filterlist for the given can_id/mask pair.
381 * Constistency checked mask.
382 * Reduced can_id to have a preprocessed filter compare value.
384 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
385 struct can_dev_rcv_lists *d)
387 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
389 /* filter for error message frames in extra filterlist */
390 if (*mask & CAN_ERR_FLAG) {
391 /* clear CAN_ERR_FLAG in filter entry */
392 *mask &= CAN_ERR_MASK;
393 return &d->rx[RX_ERR];
396 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
398 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
400 /* ensure valid values in can_mask for 'SFF only' frame filtering */
401 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
402 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
404 /* reduce condition testing at receive time */
407 /* inverse can_id/can_mask filter */
409 return &d->rx[RX_INV];
411 /* mask == 0 => no condition testing at receive time */
413 return &d->rx[RX_ALL];
415 /* extra filterlists for the subscription of a single non-RTR can_id */
416 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
417 !(*can_id & CAN_RTR_FLAG)) {
419 if (*can_id & CAN_EFF_FLAG) {
420 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
421 return &d->rx_eff[effhash(*can_id)];
423 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
424 return &d->rx_sff[*can_id];
428 /* default: filter via can_id/can_mask */
429 return &d->rx[RX_FIL];
433 * can_rx_register - subscribe CAN frames from a specific interface
434 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
435 * @can_id: CAN identifier (see description)
436 * @mask: CAN mask (see description)
437 * @func: callback function on filter match
438 * @data: returned parameter for callback function
439 * @ident: string for calling module identification
440 * @sk: socket pointer (might be NULL)
443 * Invokes the callback function with the received sk_buff and the given
444 * parameter 'data' on a matching receive filter. A filter matches, when
446 * <received_can_id> & mask == can_id & mask
448 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
449 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
451 * The provided pointer to the sk_buff is guaranteed to be valid as long as
452 * the callback function is running. The callback function must *not* free
453 * the given sk_buff while processing it's task. When the given sk_buff is
454 * needed after the end of the callback function it must be cloned inside
455 * the callback function with skb_clone().
459 * -ENOMEM on missing cache mem to create subscription entry
460 * -ENODEV unknown device
462 int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
463 canid_t mask, void (*func)(struct sk_buff *, void *),
464 void *data, char *ident, struct sock *sk)
467 struct hlist_head *rl;
468 struct can_dev_rcv_lists *d;
469 struct s_pstats *can_pstats = net->can.can_pstats;
472 /* insert new receiver (dev,canid,mask) -> (func,data) */
474 if (dev && dev->type != ARPHRD_CAN)
477 if (dev && !net_eq(net, dev_net(dev)))
480 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
484 spin_lock(&net->can.can_rcvlists_lock);
486 d = find_dev_rcv_lists(net, dev);
488 rl = find_rcv_list(&can_id, &mask, d);
498 hlist_add_head_rcu(&r->list, rl);
501 can_pstats->rcv_entries++;
502 if (can_pstats->rcv_entries_max < can_pstats->rcv_entries)
503 can_pstats->rcv_entries_max = can_pstats->rcv_entries;
505 kmem_cache_free(rcv_cache, r);
509 spin_unlock(&net->can.can_rcvlists_lock);
513 EXPORT_SYMBOL(can_rx_register);
516 * can_rx_delete_receiver - rcu callback for single receiver entry removal
518 static void can_rx_delete_receiver(struct rcu_head *rp)
520 struct receiver *r = container_of(rp, struct receiver, rcu);
521 struct sock *sk = r->sk;
523 kmem_cache_free(rcv_cache, r);
529 * can_rx_unregister - unsubscribe CAN frames from a specific interface
530 * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
531 * @can_id: CAN identifier
533 * @func: callback function on filter match
534 * @data: returned parameter for callback function
537 * Removes subscription entry depending on given (subscription) values.
539 void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
540 canid_t mask, void (*func)(struct sk_buff *, void *),
543 struct receiver *r = NULL;
544 struct hlist_head *rl;
545 struct s_pstats *can_pstats = net->can.can_pstats;
546 struct can_dev_rcv_lists *d;
548 if (dev && dev->type != ARPHRD_CAN)
551 if (dev && !net_eq(net, dev_net(dev)))
554 spin_lock(&net->can.can_rcvlists_lock);
556 d = find_dev_rcv_lists(net, 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(&net->can.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 can_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 can_dev_rcv_lists *d;
687 struct net *net = dev_net(dev);
688 struct s_stats *can_stats = net->can.can_stats;
691 /* update statistics */
692 can_stats->rx_frames++;
693 can_stats->rx_frames_delta++;
695 /* create non-zero unique skb identifier together with *skb */
696 while (!(can_skb_prv(skb)->skbcnt))
697 can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);
701 /* deliver the packet to sockets listening on all devices */
702 matches = can_rcv_filter(net->can.can_rx_alldev_list, skb);
704 /* find receive list for this device */
705 d = find_dev_rcv_lists(net, dev);
707 matches += can_rcv_filter(d, skb);
711 /* consume the skbuff allocated by the netdevice driver */
715 can_stats->matches++;
716 can_stats->matches_delta++;
720 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
721 struct packet_type *pt, struct net_device *orig_dev)
723 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
725 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) {
726 pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n",
727 dev->type, skb->len);
731 /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
732 if (unlikely(cfd->len > CAN_MAX_DLEN)) {
733 pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n",
734 dev->type, skb->len, cfd->len);
738 can_receive(skb, dev);
739 return NET_RX_SUCCESS;
746 static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
747 struct packet_type *pt, struct net_device *orig_dev)
749 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
751 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) {
752 pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n",
753 dev->type, skb->len);
757 /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
758 if (unlikely(cfd->len > CANFD_MAX_DLEN)) {
759 pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n",
760 dev->type, skb->len, cfd->len);
764 can_receive(skb, dev);
765 return NET_RX_SUCCESS;
773 * af_can protocol functions
777 * can_proto_register - register CAN transport protocol
778 * @cp: pointer to CAN protocol structure
782 * -EINVAL invalid (out of range) protocol number
783 * -EBUSY protocol already in use
784 * -ENOBUF if proto_register() fails
786 int can_proto_register(const struct can_proto *cp)
788 int proto = cp->protocol;
791 if (proto < 0 || proto >= CAN_NPROTO) {
792 pr_err("can: protocol number %d out of range\n", proto);
796 err = proto_register(cp->prot, 0);
800 mutex_lock(&proto_tab_lock);
802 if (rcu_access_pointer(proto_tab[proto])) {
803 pr_err("can: protocol %d already registered\n", proto);
806 RCU_INIT_POINTER(proto_tab[proto], cp);
808 mutex_unlock(&proto_tab_lock);
811 proto_unregister(cp->prot);
815 EXPORT_SYMBOL(can_proto_register);
818 * can_proto_unregister - unregister CAN transport protocol
819 * @cp: pointer to CAN protocol structure
821 void can_proto_unregister(const struct can_proto *cp)
823 int proto = cp->protocol;
825 mutex_lock(&proto_tab_lock);
826 BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp);
827 RCU_INIT_POINTER(proto_tab[proto], NULL);
828 mutex_unlock(&proto_tab_lock);
832 proto_unregister(cp->prot);
834 EXPORT_SYMBOL(can_proto_unregister);
837 * af_can notifier to create/remove CAN netdevice specific structs
839 static int can_notifier(struct notifier_block *nb, unsigned long msg,
842 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
843 struct can_dev_rcv_lists *d;
845 if (dev->type != ARPHRD_CAN)
850 case NETDEV_REGISTER:
852 /* create new dev_rcv_lists for this device */
853 d = kzalloc(sizeof(*d), GFP_KERNEL);
856 BUG_ON(dev->ml_priv);
861 case NETDEV_UNREGISTER:
862 spin_lock(&dev_net(dev)->can.can_rcvlists_lock);
867 d->remove_on_zero_entries = 1;
873 pr_err("can: notifier: receive list not found for dev "
876 spin_unlock(&dev_net(dev)->can.can_rcvlists_lock);
884 static int can_pernet_init(struct net *net)
886 spin_lock_init(&net->can.can_rcvlists_lock);
887 net->can.can_rx_alldev_list =
888 kzalloc(sizeof(struct can_dev_rcv_lists), GFP_KERNEL);
889 if (!net->can.can_rx_alldev_list)
891 net->can.can_stats = kzalloc(sizeof(struct s_stats), GFP_KERNEL);
892 if (!net->can.can_stats)
893 goto out_free_alldev_list;
894 net->can.can_pstats = kzalloc(sizeof(struct s_pstats), GFP_KERNEL);
895 if (!net->can.can_pstats)
896 goto out_free_can_stats;
898 if (IS_ENABLED(CONFIG_PROC_FS)) {
899 /* the statistics are updated every second (timer triggered) */
901 timer_setup(&net->can.can_stattimer, can_stat_update,
903 mod_timer(&net->can.can_stattimer,
904 round_jiffies(jiffies + HZ));
906 net->can.can_stats->jiffies_init = jiffies;
913 kfree(net->can.can_stats);
914 out_free_alldev_list:
915 kfree(net->can.can_rx_alldev_list);
920 static void can_pernet_exit(struct net *net)
922 struct net_device *dev;
924 if (IS_ENABLED(CONFIG_PROC_FS)) {
925 can_remove_proc(net);
927 del_timer_sync(&net->can.can_stattimer);
930 /* remove created dev_rcv_lists from still registered CAN devices */
932 for_each_netdev_rcu(net, dev) {
933 if (dev->type == ARPHRD_CAN && dev->ml_priv) {
934 struct can_dev_rcv_lists *d = dev->ml_priv;
943 kfree(net->can.can_rx_alldev_list);
944 kfree(net->can.can_stats);
945 kfree(net->can.can_pstats);
949 * af_can module init/exit functions
952 static struct packet_type can_packet __read_mostly = {
953 .type = cpu_to_be16(ETH_P_CAN),
957 static struct packet_type canfd_packet __read_mostly = {
958 .type = cpu_to_be16(ETH_P_CANFD),
962 static const struct net_proto_family can_family_ops = {
964 .create = can_create,
965 .owner = THIS_MODULE,
968 /* notifier block for netdevice event */
969 static struct notifier_block can_netdev_notifier __read_mostly = {
970 .notifier_call = can_notifier,
973 static struct pernet_operations can_pernet_ops __read_mostly = {
974 .init = can_pernet_init,
975 .exit = can_pernet_exit,
978 static __init int can_init(void)
982 /* check for correct padding to be able to use the structs similarly */
983 BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
984 offsetof(struct canfd_frame, len) ||
985 offsetof(struct can_frame, data) !=
986 offsetof(struct canfd_frame, data));
988 pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");
990 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
995 err = register_pernet_subsys(&can_pernet_ops);
999 /* protocol register */
1000 err = sock_register(&can_family_ops);
1003 err = register_netdevice_notifier(&can_netdev_notifier);
1007 dev_add_pack(&can_packet);
1008 dev_add_pack(&canfd_packet);
1013 sock_unregister(PF_CAN);
1015 unregister_pernet_subsys(&can_pernet_ops);
1017 kmem_cache_destroy(rcv_cache);
1022 static __exit void can_exit(void)
1024 /* protocol unregister */
1025 dev_remove_pack(&canfd_packet);
1026 dev_remove_pack(&can_packet);
1027 unregister_netdevice_notifier(&can_netdev_notifier);
1028 sock_unregister(PF_CAN);
1030 unregister_pernet_subsys(&can_pernet_ops);
1032 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1034 kmem_cache_destroy(rcv_cache);
1037 module_init(can_init);
1038 module_exit(can_exit);