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 <socketcan/can.h>
65 #include <socketcan/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 <socketcan/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(2,6,33)
143 static int can_create(struct net *net, struct socket *sock, int protocol, int kern)
144 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
145 static int can_create(struct net *net, struct socket *sock, int protocol)
147 static int can_create(struct socket *sock, int protocol)
151 struct can_proto *cp;
154 sock->state = SS_UNCONNECTED;
156 if (protocol < 0 || protocol >= CAN_NPROTO)
159 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
160 if (net != &init_net)
161 return -EAFNOSUPPORT;
164 #ifdef CONFIG_MODULES
165 /* try to load protocol module kernel is modular */
166 if (!proto_tab[protocol]) {
167 err = request_module("can-proto-%d", protocol);
170 * In case of error we only print a message but don't
171 * return the error code immediately. Below we will
172 * return -EPROTONOSUPPORT
174 if (err && printk_ratelimit())
175 printk(KERN_ERR "can: request_module "
176 "(can-proto-%d) failed.\n", protocol);
180 spin_lock(&proto_tab_lock);
181 cp = proto_tab[protocol];
182 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
183 if (cp && !try_module_get(cp->prot->owner))
186 if (cp && !try_module_get(cp->owner))
189 spin_unlock(&proto_tab_lock);
191 /* check for available protocol and correct usage */
194 return -EPROTONOSUPPORT;
196 if (cp->type != sock->type) {
197 err = -EPROTONOSUPPORT;
201 if (cp->capability >= 0 && !capable(cp->capability)) {
208 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
209 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
210 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
211 sk = sk_alloc(PF_CAN, GFP_KERNEL, cp->prot, 1);
213 sk = sk_alloc(PF_CAN, GFP_KERNEL, 1, 0);
220 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
222 sk->sk_protinfo = kmalloc(cp->obj_size, GFP_KERNEL);
223 if (!sk->sk_protinfo) {
229 sk_set_owner(sk, proto_tab[protocol]->owner);
232 sock_init_data(sock, sk);
233 sk->sk_destruct = can_sock_destruct;
235 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
236 if (sk->sk_prot->init)
237 err = sk->sk_prot->init(sk);
244 /* release sk on errors */
250 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
251 module_put(cp->prot->owner);
253 module_put(cp->owner);
263 * can_send - transmit a CAN frame (optional with local loopback)
264 * @skb: pointer to socket buffer with CAN frame in data section
265 * @loop: loopback for listeners on local CAN sockets (recommended default!)
267 * Due to the loopback this routine must not be called from hardirq context.
271 * -ENETDOWN when the selected interface is down
272 * -ENOBUFS on full driver queue (see net_xmit_errno())
273 * -ENOMEM when local loopback failed at calling skb_clone()
274 * -EPERM when trying to send on a non-CAN interface
275 * -EINVAL when the skb->data does not contain a valid CAN frame
277 int can_send(struct sk_buff *skb, int loop)
279 struct sk_buff *newskb = NULL;
280 struct can_frame *cf = (struct can_frame *)skb->data;
283 if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
288 if (skb->dev->type != ARPHRD_CAN) {
293 if (!(skb->dev->flags & IFF_UP)) {
298 skb->protocol = htons(ETH_P_CAN);
299 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
300 skb_reset_network_header(skb);
301 skb_reset_transport_header(skb);
303 skb->nh.raw = skb->data;
304 skb->h.raw = skb->data;
308 /* local loopback of sent CAN frames */
310 /* indication for the CAN driver: do loopback */
311 skb->pkt_type = PACKET_LOOPBACK;
314 * The reference to the originating sock may be required
315 * by the receiving socket to check whether the frame is
316 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
317 * Therefore we have to ensure that skb->sk remains the
318 * reference to the originating sock by restoring skb->sk
319 * after each skb_clone() or skb_orphan() usage.
322 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
323 #define IFF_ECHO IFF_LOOPBACK
325 if (!(skb->dev->flags & IFF_ECHO)) {
327 * If the interface is not capable to do loopback
328 * itself, we do it here.
330 newskb = skb_clone(skb, GFP_ATOMIC);
336 newskb->sk = skb->sk;
337 newskb->ip_summed = CHECKSUM_UNNECESSARY;
338 newskb->pkt_type = PACKET_BROADCAST;
341 /* indication for the CAN driver: no loopback required */
342 skb->pkt_type = PACKET_HOST;
345 /* send to netdevice */
346 err = dev_queue_xmit(skb);
348 err = net_xmit_errno(err);
351 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)
352 /* kfree_skb() does not check for !NULL on older kernels */
364 /* update statistics */
365 can_stats.tx_frames++;
366 can_stats.tx_frames_delta++;
370 EXPORT_SYMBOL(can_send);
376 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
378 struct dev_rcv_lists *d = NULL;
379 struct hlist_node *n;
381 /* find receive list for this device */
383 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
385 * Since 2.6.26 a new "midlevel private" ml_priv pointer has been
386 * introduced in struct net_device. We use this pointer to omit the
387 * linear walk through the can_rx_dev_list. A similar speedup has been
388 * queued for 2.6.34 mainline but using the new netdev_rcu lists.
391 /* dev == NULL is the indicator for the 'all' filterlist */
393 return &can_rx_alldev_list;
395 /* do not search in rcu list when we have a direct reference */
397 return (struct dev_rcv_lists *)dev->ml_priv;
399 /* fall back to standard behaviour */
403 * The hlist_for_each_entry*() macros curse through the list
404 * using the pointer variable n and set d to the containing
405 * struct in each list iteration. Therefore, after list
406 * iteration, d is unmodified when the list is empty, and it
407 * points to last list element, when the list is non-empty
408 * but no match in the loop body is found. I.e. d is *not*
409 * NULL when no match is found. We can, however, use the
410 * cursor variable n to decide if a match was found.
413 hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
422 * find_rcv_list - determine optimal filterlist inside device filter struct
423 * @can_id: pointer to CAN identifier of a given can_filter
424 * @mask: pointer to CAN mask of a given can_filter
425 * @d: pointer to the device filter struct
428 * Returns the optimal filterlist to reduce the filter handling in the
429 * receive path. This function is called by service functions that need
430 * to register or unregister a can_filter in the filter lists.
432 * A filter matches in general, when
434 * <received_can_id> & mask == can_id & mask
436 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
437 * relevant bits for the filter.
439 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
440 * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
441 * there is a special filterlist and a special rx path filter handling.
444 * Pointer to optimal filterlist for the given can_id/mask pair.
445 * Constistency checked mask.
446 * Reduced can_id to have a preprocessed filter compare value.
448 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
449 struct dev_rcv_lists *d)
451 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
453 /* filter for error frames in extra filterlist */
454 if (*mask & CAN_ERR_FLAG) {
455 /* clear CAN_ERR_FLAG in filter entry */
456 *mask &= CAN_ERR_MASK;
457 return &d->rx[RX_ERR];
460 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
462 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
464 /* ensure valid values in can_mask for 'SFF only' frame filtering */
465 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
466 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
468 /* reduce condition testing at receive time */
471 /* inverse can_id/can_mask filter */
473 return &d->rx[RX_INV];
475 /* mask == 0 => no condition testing at receive time */
477 return &d->rx[RX_ALL];
479 /* extra filterlists for the subscription of a single non-RTR can_id */
480 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS)
481 && !(*can_id & CAN_RTR_FLAG)) {
483 if (*can_id & CAN_EFF_FLAG) {
484 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
485 /* RFC: a future use-case for hash-tables? */
486 return &d->rx[RX_EFF];
489 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
490 return &d->rx_sff[*can_id];
494 /* default: filter via can_id/can_mask */
495 return &d->rx[RX_FIL];
499 * can_rx_register - subscribe CAN frames from a specific interface
500 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
501 * @can_id: CAN identifier (see description)
502 * @mask: CAN mask (see description)
503 * @func: callback function on filter match
504 * @data: returned parameter for callback function
505 * @ident: string for calling module indentification
508 * Invokes the callback function with the received sk_buff and the given
509 * parameter 'data' on a matching receive filter. A filter matches, when
511 * <received_can_id> & mask == can_id & mask
513 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
514 * filter for error frames (CAN_ERR_FLAG bit set in mask).
516 * The provided pointer to the sk_buff is guaranteed to be valid as long as
517 * the callback function is running. The callback function must *not* free
518 * the given sk_buff while processing it's task. When the given sk_buff is
519 * needed after the end of the callback function it must be cloned inside
520 * the callback function with skb_clone().
524 * -ENOMEM on missing cache mem to create subscription entry
525 * -ENODEV unknown device
527 int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
528 void (*func)(struct sk_buff *, void *), void *data,
532 struct hlist_head *rl;
533 struct dev_rcv_lists *d;
536 /* insert new receiver (dev,canid,mask) -> (func,data) */
538 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
542 spin_lock(&can_rcvlists_lock);
544 d = find_dev_rcv_lists(dev);
546 rl = find_rcv_list(&can_id, &mask, d);
555 hlist_add_head_rcu(&r->list, rl);
558 can_pstats.rcv_entries++;
559 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
560 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
562 kmem_cache_free(rcv_cache, r);
566 spin_unlock(&can_rcvlists_lock);
570 EXPORT_SYMBOL(can_rx_register);
573 * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
575 static void can_rx_delete_device(struct rcu_head *rp)
577 struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
583 * can_rx_delete_receiver - rcu callback for single receiver entry removal
585 static void can_rx_delete_receiver(struct rcu_head *rp)
587 struct receiver *r = container_of(rp, struct receiver, rcu);
589 kmem_cache_free(rcv_cache, r);
593 * can_rx_unregister - unsubscribe CAN frames from a specific interface
594 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
595 * @can_id: CAN identifier
597 * @func: callback function on filter match
598 * @data: returned parameter for callback function
601 * Removes subscription entry depending on given (subscription) values.
603 void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
604 void (*func)(struct sk_buff *, void *), void *data)
606 struct receiver *r = NULL;
607 struct hlist_head *rl;
608 struct hlist_node *next;
609 struct dev_rcv_lists *d;
611 spin_lock(&can_rcvlists_lock);
613 d = find_dev_rcv_lists(dev);
615 printk(KERN_ERR "BUG: receive list not found for "
616 "dev %s, id %03X, mask %03X\n",
617 DNAME(dev), can_id, mask);
621 rl = find_rcv_list(&can_id, &mask, d);
624 * Search the receiver list for the item to delete. This should
625 * exist, since no receiver may be unregistered that hasn't
626 * been registered before.
629 hlist_for_each_entry_rcu(r, next, rl, list) {
630 if (r->can_id == can_id && r->mask == mask
631 && r->func == func && r->data == data)
636 * Check for bugs in CAN protocol implementations:
637 * If no matching list item was found, the list cursor variable next
638 * will be NULL, while r will point to the last item of the list.
642 printk(KERN_ERR "BUG: receive list entry not found for "
643 "dev %s, id %03X, mask %03X\n",
644 DNAME(dev), can_id, mask);
650 hlist_del_rcu(&r->list);
653 if (can_pstats.rcv_entries > 0)
654 can_pstats.rcv_entries--;
656 /* remove device structure requested by NETDEV_UNREGISTER */
657 if (d->remove_on_zero_entries && !d->entries)
658 hlist_del_rcu(&d->list);
663 spin_unlock(&can_rcvlists_lock);
665 /* schedule the receiver item for deletion */
667 call_rcu(&r->rcu, can_rx_delete_receiver);
669 /* schedule the device structure for deletion */
671 call_rcu(&d->rcu, can_rx_delete_device);
673 EXPORT_SYMBOL(can_rx_unregister);
675 static inline void deliver(struct sk_buff *skb, struct receiver *r)
677 r->func(skb, r->data);
681 static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
684 struct hlist_node *n;
686 struct can_frame *cf = (struct can_frame *)skb->data;
687 canid_t can_id = cf->can_id;
692 if (can_id & CAN_ERR_FLAG) {
693 /* check for error frame entries only */
694 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
695 if (can_id & r->mask) {
703 /* check for unfiltered entries */
704 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
709 /* check for can_id/mask entries */
710 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
711 if ((can_id & r->mask) == r->can_id) {
717 /* check for inverted can_id/mask entries */
718 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
719 if ((can_id & r->mask) != r->can_id) {
725 /* check filterlists for single non-RTR can_ids */
726 if (can_id & CAN_RTR_FLAG)
729 if (can_id & CAN_EFF_FLAG) {
730 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
731 if (r->can_id == can_id) {
737 can_id &= CAN_SFF_MASK;
738 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
747 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
748 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
749 struct packet_type *pt, struct net_device *orig_dev)
751 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
752 struct packet_type *pt)
755 struct dev_rcv_lists *d;
756 struct can_frame *cf = (struct can_frame *)skb->data;
759 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
760 if (!net_eq(dev_net(dev), &init_net))
762 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
763 if (dev->nd_net != &init_net)
767 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
768 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
769 skb->len != sizeof(struct can_frame) ||
771 "PF_CAN: dropped non conform skbuf: "
772 "dev type %d, len %d, can_dlc %d\n",
773 dev->type, skb->len, cf->can_dlc))
776 BUG_ON(dev->type != ARPHRD_CAN ||
777 skb->len != sizeof(struct can_frame) ||
781 /* update statistics */
782 can_stats.rx_frames++;
783 can_stats.rx_frames_delta++;
787 /* deliver the packet to sockets listening on all devices */
788 matches = can_rcv_filter(&can_rx_alldev_list, skb);
790 /* find receive list for this device */
791 d = find_dev_rcv_lists(dev);
793 matches += can_rcv_filter(d, skb);
797 /* consume the skbuff allocated by the netdevice driver */
798 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
806 can_stats.matches_delta++;
809 return NET_RX_SUCCESS;
811 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
819 * af_can protocol functions
823 * can_proto_register - register CAN transport protocol
824 * @cp: pointer to CAN protocol structure
828 * -EINVAL invalid (out of range) protocol number
829 * -EBUSY protocol already in use
830 * -ENOBUF if proto_register() fails
832 int can_proto_register(struct can_proto *cp)
834 int proto = cp->protocol;
837 if (proto < 0 || proto >= CAN_NPROTO) {
838 printk(KERN_ERR "can: protocol number %d out of range\n",
843 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
844 err = proto_register(cp->prot, 0);
849 spin_lock(&proto_tab_lock);
850 if (proto_tab[proto]) {
851 printk(KERN_ERR "can: protocol %d already registered\n",
855 proto_tab[proto] = cp;
857 /* use generic ioctl function if not defined by module */
859 cp->ops->ioctl = can_ioctl;
861 spin_unlock(&proto_tab_lock);
863 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
865 proto_unregister(cp->prot);
870 EXPORT_SYMBOL(can_proto_register);
873 * can_proto_unregister - unregister CAN transport protocol
874 * @cp: pointer to CAN protocol structure
876 void can_proto_unregister(struct can_proto *cp)
878 int proto = cp->protocol;
880 spin_lock(&proto_tab_lock);
881 if (!proto_tab[proto]) {
882 printk(KERN_ERR "BUG: can: protocol %d is not registered\n",
885 proto_tab[proto] = NULL;
886 spin_unlock(&proto_tab_lock);
888 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
889 proto_unregister(cp->prot);
892 EXPORT_SYMBOL(can_proto_unregister);
895 * af_can notifier to create/remove CAN netdevice specific structs
897 static int can_notifier(struct notifier_block *nb, unsigned long msg,
900 struct net_device *dev = (struct net_device *)data;
901 struct dev_rcv_lists *d;
903 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
904 if (!net_eq(dev_net(dev), &init_net))
906 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
907 if (dev->nd_net != &init_net)
911 if (dev->type != ARPHRD_CAN)
916 case NETDEV_REGISTER:
919 * create new dev_rcv_lists for this device
921 * N.B. zeroing the struct is the correct initialization
922 * for the embedded hlist_head structs.
923 * Another list type, e.g. list_head, would require
924 * explicit initialization.
927 d = kzalloc(sizeof(*d), GFP_KERNEL);
930 "can: allocation of receive list failed\n");
935 spin_lock(&can_rcvlists_lock);
936 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
939 hlist_add_head_rcu(&d->list, &can_rx_dev_list);
940 spin_unlock(&can_rcvlists_lock);
944 case NETDEV_UNREGISTER:
945 spin_lock(&can_rcvlists_lock);
947 d = find_dev_rcv_lists(dev);
950 d->remove_on_zero_entries = 1;
953 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
956 hlist_del_rcu(&d->list);
959 printk(KERN_ERR "can: notifier: receive list not "
960 "found for dev %s\n", dev->name);
962 spin_unlock(&can_rcvlists_lock);
965 call_rcu(&d->rcu, can_rx_delete_device);
974 * af_can module init/exit functions
977 static struct packet_type can_packet __read_mostly = {
978 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
979 .type = cpu_to_be16(ETH_P_CAN),
981 .type = __constant_htons(ETH_P_CAN),
987 static struct net_proto_family can_family_ops __read_mostly = {
989 .create = can_create,
990 .owner = THIS_MODULE,
993 /* notifier block for netdevice event */
994 static struct notifier_block can_netdev_notifier __read_mostly = {
995 .notifier_call = can_notifier,
998 static __init int can_init(void)
1002 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
1003 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
1006 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
1013 * Insert can_rx_alldev_list for reception on all devices.
1014 * This struct is zero initialized which is correct for the
1015 * embedded hlist heads, the dev pointer, and the entries counter.
1018 spin_lock(&can_rcvlists_lock);
1019 hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
1020 spin_unlock(&can_rcvlists_lock);
1023 /* the statistics are updated every second (timer triggered) */
1024 setup_timer(&can_stattimer, can_stat_update, 0);
1025 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
1027 can_stattimer.function = NULL;
1031 /* protocol register */
1032 sock_register(&can_family_ops);
1033 register_netdevice_notifier(&can_netdev_notifier);
1034 dev_add_pack(&can_packet);
1039 static __exit void can_exit(void)
1041 struct dev_rcv_lists *d;
1042 struct hlist_node *n, *next;
1045 del_timer(&can_stattimer);
1049 /* protocol unregister */
1050 dev_remove_pack(&can_packet);
1051 unregister_netdevice_notifier(&can_netdev_notifier);
1052 sock_unregister(PF_CAN);
1054 /* remove can_rx_dev_list */
1055 spin_lock(&can_rcvlists_lock);
1056 hlist_del(&can_rx_alldev_list.list);
1057 hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
1058 hlist_del(&d->list);
1061 spin_unlock(&can_rcvlists_lock);
1063 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
1064 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1067 kmem_cache_destroy(rcv_cache);
1070 module_init(can_init);
1071 module_exit(can_exit);