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
41 * Send feedback to <socketcan-users@lists.berlios.de>
45 #include <linux/module.h>
46 #include <linux/version.h>
47 #include <linux/init.h>
48 #include <linux/kmod.h>
49 #include <linux/slab.h>
50 #include <linux/list.h>
51 #include <linux/spinlock.h>
52 #include <linux/rcupdate.h>
53 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
54 #include <linux/uaccess.h>
56 #include <asm/uaccess.h>
58 #include <linux/net.h>
59 #include <linux/netdevice.h>
60 #include <linux/socket.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_arp.h>
63 #include <linux/skbuff.h>
64 #include <linux/can.h>
65 #include <linux/can/core.h>
66 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
67 #include <net/net_namespace.h>
72 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
76 #include <linux/can/version.h> /* for RCSID. Removed by mkpatch script */
79 static __initdata const char banner[] = KERN_INFO
80 "can: controller area network core (" CAN_VERSION_STRING ")\n";
82 MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
83 MODULE_LICENSE("Dual BSD/GPL");
84 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
85 "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
87 MODULE_ALIAS_NETPROTO(PF_CAN);
89 static int stats_timer __read_mostly = 1;
90 module_param(stats_timer, int, S_IRUGO);
91 MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
93 HLIST_HEAD(can_rx_dev_list);
94 static struct dev_rcv_lists can_rx_alldev_list;
95 static DEFINE_SPINLOCK(can_rcvlists_lock);
97 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
98 static struct kmem_cache *rcv_cache __read_mostly;
100 static kmem_cache_t *rcv_cache;
103 /* table of registered CAN protocols */
104 static struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
105 static DEFINE_SPINLOCK(proto_tab_lock);
107 struct timer_list can_stattimer; /* timer for statistics update */
108 struct s_stats can_stats; /* packet statistics */
109 struct s_pstats can_pstats; /* receive list statistics */
112 * af_can socket functions
115 static int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
117 struct sock *sk = sock->sk;
122 return sock_get_timestamp(sk, (struct timeval __user *)arg);
125 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
128 return dev_ioctl(cmd, (void __user *)arg);
133 static void can_sock_destruct(struct sock *sk)
135 skb_queue_purge(&sk->sk_receive_queue);
136 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
138 kfree(sk->sk_protinfo);
142 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
143 static int can_create(struct net *net, struct socket *sock, int protocol)
145 static int can_create(struct socket *sock, int protocol)
149 struct can_proto *cp;
152 sock->state = SS_UNCONNECTED;
154 if (protocol < 0 || protocol >= CAN_NPROTO)
157 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
158 if (net != &init_net)
159 return -EAFNOSUPPORT;
163 /* try to load protocol module, when CONFIG_KMOD is defined */
164 if (!proto_tab[protocol]) {
165 err = request_module("can-proto-%d", protocol);
168 * In case of error we only print a message but don't
169 * return the error code immediately. Below we will
170 * return -EPROTONOSUPPORT
172 if (err && printk_ratelimit())
173 printk(KERN_ERR "can: request_module "
174 "(can-proto-%d) failed.\n", protocol);
178 spin_lock(&proto_tab_lock);
179 cp = proto_tab[protocol];
180 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
181 if (cp && !try_module_get(cp->prot->owner))
184 if (cp && !try_module_get(cp->owner))
187 spin_unlock(&proto_tab_lock);
189 /* check for available protocol and correct usage */
192 return -EPROTONOSUPPORT;
194 if (cp->type != sock->type) {
195 err = -EPROTONOSUPPORT;
199 if (cp->capability >= 0 && !capable(cp->capability)) {
206 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
207 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
208 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
209 sk = sk_alloc(PF_CAN, GFP_KERNEL, cp->prot, 1);
211 sk = sk_alloc(PF_CAN, GFP_KERNEL, 1, 0);
218 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
220 sk->sk_protinfo = kmalloc(cp->obj_size, GFP_KERNEL);
221 if (!sk->sk_protinfo) {
227 sk_set_owner(sk, proto_tab[protocol]->owner);
230 sock_init_data(sock, sk);
231 sk->sk_destruct = can_sock_destruct;
233 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
234 if (sk->sk_prot->init)
235 err = sk->sk_prot->init(sk);
242 /* release sk on errors */
248 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
249 module_put(cp->prot->owner);
251 module_put(cp->owner);
261 * can_send - transmit a CAN frame (optional with local loopback)
262 * @skb: pointer to socket buffer with CAN frame in data section
263 * @loop: loopback for listeners on local CAN sockets (recommended default!)
267 * -ENETDOWN when the selected interface is down
268 * -ENOBUFS on full driver queue (see net_xmit_errno())
269 * -ENOMEM when local loopback failed at calling skb_clone()
270 * -EPERM when trying to send on a non-CAN interface
271 * -EINVAL when the skb->data does not contain a valid CAN frame
273 int can_send(struct sk_buff *skb, int loop)
275 struct sk_buff *newskb = NULL;
276 struct can_frame *cf = (struct can_frame *)skb->data;
279 if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
284 if (skb->dev->type != ARPHRD_CAN) {
289 if (!(skb->dev->flags & IFF_UP)) {
294 skb->protocol = htons(ETH_P_CAN);
295 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
296 skb_reset_network_header(skb);
297 skb_reset_transport_header(skb);
299 skb->nh.raw = skb->data;
300 skb->h.raw = skb->data;
304 /* local loopback of sent CAN frames */
306 /* indication for the CAN driver: do loopback */
307 skb->pkt_type = PACKET_LOOPBACK;
310 * The reference to the originating sock may be required
311 * by the receiving socket to check whether the frame is
312 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
313 * Therefore we have to ensure that skb->sk remains the
314 * reference to the originating sock by restoring skb->sk
315 * after each skb_clone() or skb_orphan() usage.
318 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
319 #define IFF_ECHO IFF_LOOPBACK
321 if (!(skb->dev->flags & IFF_ECHO)) {
323 * If the interface is not capable to do loopback
324 * itself, we do it here.
326 newskb = skb_clone(skb, GFP_ATOMIC);
332 newskb->sk = skb->sk;
333 newskb->ip_summed = CHECKSUM_UNNECESSARY;
334 newskb->pkt_type = PACKET_BROADCAST;
337 /* indication for the CAN driver: no loopback required */
338 skb->pkt_type = PACKET_HOST;
341 /* send to netdevice */
342 err = dev_queue_xmit(skb);
344 err = net_xmit_errno(err);
355 /* update statistics */
356 can_stats.tx_frames++;
357 can_stats.tx_frames_delta++;
361 EXPORT_SYMBOL(can_send);
367 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
369 struct dev_rcv_lists *d = NULL;
370 struct hlist_node *n;
373 * find receive list for this device
375 * The hlist_for_each_entry*() macros curse through the list
376 * using the pointer variable n and set d to the containing
377 * struct in each list iteration. Therefore, after list
378 * iteration, d is unmodified when the list is empty, and it
379 * points to last list element, when the list is non-empty
380 * but no match in the loop body is found. I.e. d is *not*
381 * NULL when no match is found. We can, however, use the
382 * cursor variable n to decide if a match was found.
385 hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
394 * find_rcv_list - determine optimal filterlist inside device filter struct
395 * @can_id: pointer to CAN identifier of a given can_filter
396 * @mask: pointer to CAN mask of a given can_filter
397 * @d: pointer to the device filter struct
400 * Returns the optimal filterlist to reduce the filter handling in the
401 * receive path. This function is called by service functions that need
402 * to register or unregister a can_filter in the filter lists.
404 * A filter matches in general, when
406 * <received_can_id> & mask == can_id & mask
408 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
409 * relevant bits for the filter.
411 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
412 * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
413 * there is a special filterlist and a special rx path filter handling.
416 * Pointer to optimal filterlist for the given can_id/mask pair.
417 * Constistency checked mask.
418 * Reduced can_id to have a preprocessed filter compare value.
420 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
421 struct dev_rcv_lists *d)
423 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
425 /* filter for error frames in extra filterlist */
426 if (*mask & CAN_ERR_FLAG) {
427 /* clear CAN_ERR_FLAG in filter entry */
428 *mask &= CAN_ERR_MASK;
429 return &d->rx[RX_ERR];
432 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
434 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
436 /* ensure valid values in can_mask for 'SFF only' frame filtering */
437 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
438 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
440 /* reduce condition testing at receive time */
443 /* inverse can_id/can_mask filter */
445 return &d->rx[RX_INV];
447 /* mask == 0 => no condition testing at receive time */
449 return &d->rx[RX_ALL];
451 /* extra filterlists for the subscription of a single non-RTR can_id */
452 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS)
453 && !(*can_id & CAN_RTR_FLAG)) {
455 if (*can_id & CAN_EFF_FLAG) {
456 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
457 /* RFC: a future use-case for hash-tables? */
458 return &d->rx[RX_EFF];
461 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
462 return &d->rx_sff[*can_id];
466 /* default: filter via can_id/can_mask */
467 return &d->rx[RX_FIL];
471 * can_rx_register - subscribe CAN frames from a specific interface
472 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
473 * @can_id: CAN identifier (see description)
474 * @mask: CAN mask (see description)
475 * @func: callback function on filter match
476 * @data: returned parameter for callback function
477 * @ident: string for calling module indentification
480 * Invokes the callback function with the received sk_buff and the given
481 * parameter 'data' on a matching receive filter. A filter matches, when
483 * <received_can_id> & mask == can_id & mask
485 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
486 * filter for error frames (CAN_ERR_FLAG bit set in mask).
490 * -ENOMEM on missing cache mem to create subscription entry
491 * -ENODEV unknown device
493 int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
494 void (*func)(struct sk_buff *, void *), void *data,
498 struct hlist_head *rl;
499 struct dev_rcv_lists *d;
502 /* insert new receiver (dev,canid,mask) -> (func,data) */
504 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
508 spin_lock(&can_rcvlists_lock);
510 d = find_dev_rcv_lists(dev);
512 rl = find_rcv_list(&can_id, &mask, d);
521 hlist_add_head_rcu(&r->list, rl);
524 can_pstats.rcv_entries++;
525 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
526 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
528 kmem_cache_free(rcv_cache, r);
532 spin_unlock(&can_rcvlists_lock);
536 EXPORT_SYMBOL(can_rx_register);
539 * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
541 static void can_rx_delete_device(struct rcu_head *rp)
543 struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
549 * can_rx_delete_receiver - rcu callback for single receiver entry removal
551 static void can_rx_delete_receiver(struct rcu_head *rp)
553 struct receiver *r = container_of(rp, struct receiver, rcu);
555 kmem_cache_free(rcv_cache, r);
559 * can_rx_unregister - unsubscribe CAN frames from a specific interface
560 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
561 * @can_id: CAN identifier
563 * @func: callback function on filter match
564 * @data: returned parameter for callback function
567 * Removes subscription entry depending on given (subscription) values.
569 void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
570 void (*func)(struct sk_buff *, void *), void *data)
572 struct receiver *r = NULL;
573 struct hlist_head *rl;
574 struct hlist_node *next;
575 struct dev_rcv_lists *d;
577 spin_lock(&can_rcvlists_lock);
579 d = find_dev_rcv_lists(dev);
581 printk(KERN_ERR "BUG: receive list not found for "
582 "dev %s, id %03X, mask %03X\n",
583 DNAME(dev), can_id, mask);
587 rl = find_rcv_list(&can_id, &mask, d);
590 * Search the receiver list for the item to delete. This should
591 * exist, since no receiver may be unregistered that hasn't
592 * been registered before.
595 hlist_for_each_entry_rcu(r, next, rl, list) {
596 if (r->can_id == can_id && r->mask == mask
597 && r->func == func && r->data == data)
602 * Check for bugs in CAN protocol implementations:
603 * If no matching list item was found, the list cursor variable next
604 * will be NULL, while r will point to the last item of the list.
608 printk(KERN_ERR "BUG: receive list entry not found for "
609 "dev %s, id %03X, mask %03X\n",
610 DNAME(dev), can_id, mask);
616 hlist_del_rcu(&r->list);
619 if (can_pstats.rcv_entries > 0)
620 can_pstats.rcv_entries--;
622 /* remove device structure requested by NETDEV_UNREGISTER */
623 if (d->remove_on_zero_entries && !d->entries)
624 hlist_del_rcu(&d->list);
629 spin_unlock(&can_rcvlists_lock);
631 /* schedule the receiver item for deletion */
633 call_rcu(&r->rcu, can_rx_delete_receiver);
635 /* schedule the device structure for deletion */
637 call_rcu(&d->rcu, can_rx_delete_device);
639 EXPORT_SYMBOL(can_rx_unregister);
641 static inline void deliver(struct sk_buff *skb, struct receiver *r)
643 struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
647 r->func(clone, r->data);
652 static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
655 struct hlist_node *n;
657 struct can_frame *cf = (struct can_frame *)skb->data;
658 canid_t can_id = cf->can_id;
663 if (can_id & CAN_ERR_FLAG) {
664 /* check for error frame entries only */
665 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
666 if (can_id & r->mask) {
674 /* check for unfiltered entries */
675 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
680 /* check for can_id/mask entries */
681 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
682 if ((can_id & r->mask) == r->can_id) {
688 /* check for inverted can_id/mask entries */
689 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
690 if ((can_id & r->mask) != r->can_id) {
696 /* check filterlists for single non-RTR can_ids */
697 if (can_id & CAN_RTR_FLAG)
700 if (can_id & CAN_EFF_FLAG) {
701 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
702 if (r->can_id == can_id) {
708 can_id &= CAN_SFF_MASK;
709 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
718 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
719 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
720 struct packet_type *pt, struct net_device *orig_dev)
722 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
723 struct packet_type *pt)
726 struct dev_rcv_lists *d;
727 struct can_frame *cf = (struct can_frame *)skb->data;
730 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
731 if (dev->type != ARPHRD_CAN || !net_eq(dev_net(dev), &init_net)) {
732 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
733 if (dev->type != ARPHRD_CAN || dev->nd_net != &init_net) {
735 if (dev->type != ARPHRD_CAN) {
741 BUG_ON(skb->len != sizeof(struct can_frame) || cf->can_dlc > 8);
743 /* update statistics */
744 can_stats.rx_frames++;
745 can_stats.rx_frames_delta++;
749 /* deliver the packet to sockets listening on all devices */
750 matches = can_rcv_filter(&can_rx_alldev_list, skb);
752 /* find receive list for this device */
753 d = find_dev_rcv_lists(dev);
755 matches += can_rcv_filter(d, skb);
759 /* free the skbuff allocated by the netdevice driver */
764 can_stats.matches_delta++;
771 * af_can protocol functions
775 * can_proto_register - register CAN transport protocol
776 * @cp: pointer to CAN protocol structure
780 * -EINVAL invalid (out of range) protocol number
781 * -EBUSY protocol already in use
782 * -ENOBUF if proto_register() fails
784 int can_proto_register(struct can_proto *cp)
786 int proto = cp->protocol;
789 if (proto < 0 || proto >= CAN_NPROTO) {
790 printk(KERN_ERR "can: protocol number %d out of range\n",
795 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
796 err = proto_register(cp->prot, 0);
801 spin_lock(&proto_tab_lock);
802 if (proto_tab[proto]) {
803 printk(KERN_ERR "can: protocol %d already registered\n",
807 proto_tab[proto] = cp;
809 /* use generic ioctl function if not defined by module */
811 cp->ops->ioctl = can_ioctl;
813 spin_unlock(&proto_tab_lock);
815 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
817 proto_unregister(cp->prot);
822 EXPORT_SYMBOL(can_proto_register);
825 * can_proto_unregister - unregister CAN transport protocol
826 * @cp: pointer to CAN protocol structure
828 void can_proto_unregister(struct can_proto *cp)
830 int proto = cp->protocol;
832 spin_lock(&proto_tab_lock);
833 if (!proto_tab[proto]) {
834 printk(KERN_ERR "BUG: can: protocol %d is not registered\n",
837 proto_tab[proto] = NULL;
838 spin_unlock(&proto_tab_lock);
840 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
841 proto_unregister(cp->prot);
844 EXPORT_SYMBOL(can_proto_unregister);
847 * af_can notifier to create/remove CAN netdevice specific structs
849 static int can_notifier(struct notifier_block *nb, unsigned long msg,
852 struct net_device *dev = (struct net_device *)data;
853 struct dev_rcv_lists *d;
855 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
856 if (!net_eq(dev_net(dev), &init_net))
858 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
859 if (dev->nd_net != &init_net)
863 if (dev->type != ARPHRD_CAN)
868 case NETDEV_REGISTER:
871 * create new dev_rcv_lists for this device
873 * N.B. zeroing the struct is the correct initialization
874 * for the embedded hlist_head structs.
875 * Another list type, e.g. list_head, would require
876 * explicit initialization.
879 d = kzalloc(sizeof(*d), GFP_KERNEL);
882 "can: allocation of receive list failed\n");
887 spin_lock(&can_rcvlists_lock);
888 hlist_add_head_rcu(&d->list, &can_rx_dev_list);
889 spin_unlock(&can_rcvlists_lock);
893 case NETDEV_UNREGISTER:
894 spin_lock(&can_rcvlists_lock);
896 d = find_dev_rcv_lists(dev);
899 d->remove_on_zero_entries = 1;
902 hlist_del_rcu(&d->list);
904 printk(KERN_ERR "can: notifier: receive list not "
905 "found for dev %s\n", dev->name);
907 spin_unlock(&can_rcvlists_lock);
910 call_rcu(&d->rcu, can_rx_delete_device);
919 * af_can module init/exit functions
922 static struct packet_type can_packet __read_mostly = {
923 .type = __constant_htons(ETH_P_CAN),
928 static struct net_proto_family can_family_ops __read_mostly = {
930 .create = can_create,
931 .owner = THIS_MODULE,
934 /* notifier block for netdevice event */
935 static struct notifier_block can_netdev_notifier __read_mostly = {
936 .notifier_call = can_notifier,
939 static __init int can_init(void)
943 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
944 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
947 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
954 * Insert can_rx_alldev_list for reception on all devices.
955 * This struct is zero initialized which is correct for the
956 * embedded hlist heads, the dev pointer, and the entries counter.
959 spin_lock(&can_rcvlists_lock);
960 hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
961 spin_unlock(&can_rcvlists_lock);
964 /* the statistics are updated every second (timer triggered) */
965 setup_timer(&can_stattimer, can_stat_update, 0);
966 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
968 can_stattimer.function = NULL;
972 /* protocol register */
973 sock_register(&can_family_ops);
974 register_netdevice_notifier(&can_netdev_notifier);
975 dev_add_pack(&can_packet);
980 static __exit void can_exit(void)
982 struct dev_rcv_lists *d;
983 struct hlist_node *n, *next;
986 del_timer(&can_stattimer);
990 /* protocol unregister */
991 dev_remove_pack(&can_packet);
992 unregister_netdevice_notifier(&can_netdev_notifier);
993 sock_unregister(PF_CAN);
995 /* remove can_rx_dev_list */
996 spin_lock(&can_rcvlists_lock);
997 hlist_del(&can_rx_alldev_list.list);
998 hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
1002 spin_unlock(&can_rcvlists_lock);
1004 kmem_cache_destroy(rcv_cache);
1007 module_init(can_init);
1008 module_exit(can_exit);