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 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
377 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
380 * find receive list for this device
382 * Since 2.6.26 a new "midlevel private" ml_priv pointer has been
383 * introduced in struct net_device. We use this pointer to omit the
384 * linear walk through the can_rx_dev_list. A similar speedup has been
385 * queued for 2.6.34 mainline but using the new netdev_rcu lists.
386 * Therefore the can_rx_dev_list is still needed (e.g. in proc.c)
389 /* dev == NULL is the indicator for the 'all' filterlist */
391 return &can_rx_alldev_list;
393 return (struct dev_rcv_lists *)dev->ml_priv;
396 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
398 struct dev_rcv_lists *d = NULL;
399 struct hlist_node *n;
402 * find receive list for this device
404 * The hlist_for_each_entry*() macros curse through the list
405 * using the pointer variable n and set d to the containing
406 * struct in each list iteration. Therefore, after list
407 * iteration, d is unmodified when the list is empty, and it
408 * points to last list element, when the list is non-empty
409 * but no match in the loop body is found. I.e. d is *not*
410 * NULL when no match is found. We can, however, use the
411 * cursor variable n to decide if a match was found.
414 hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
424 * find_rcv_list - determine optimal filterlist inside device filter struct
425 * @can_id: pointer to CAN identifier of a given can_filter
426 * @mask: pointer to CAN mask of a given can_filter
427 * @d: pointer to the device filter struct
430 * Returns the optimal filterlist to reduce the filter handling in the
431 * receive path. This function is called by service functions that need
432 * to register or unregister a can_filter in the filter lists.
434 * A filter matches in general, when
436 * <received_can_id> & mask == can_id & mask
438 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
439 * relevant bits for the filter.
441 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
442 * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
443 * there is a special filterlist and a special rx path filter handling.
446 * Pointer to optimal filterlist for the given can_id/mask pair.
447 * Constistency checked mask.
448 * Reduced can_id to have a preprocessed filter compare value.
450 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
451 struct dev_rcv_lists *d)
453 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
455 /* filter for error frames in extra filterlist */
456 if (*mask & CAN_ERR_FLAG) {
457 /* clear CAN_ERR_FLAG in filter entry */
458 *mask &= CAN_ERR_MASK;
459 return &d->rx[RX_ERR];
462 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
464 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
466 /* ensure valid values in can_mask for 'SFF only' frame filtering */
467 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
468 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
470 /* reduce condition testing at receive time */
473 /* inverse can_id/can_mask filter */
475 return &d->rx[RX_INV];
477 /* mask == 0 => no condition testing at receive time */
479 return &d->rx[RX_ALL];
481 /* extra filterlists for the subscription of a single non-RTR can_id */
482 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS)
483 && !(*can_id & CAN_RTR_FLAG)) {
485 if (*can_id & CAN_EFF_FLAG) {
486 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
487 /* RFC: a future use-case for hash-tables? */
488 return &d->rx[RX_EFF];
491 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
492 return &d->rx_sff[*can_id];
496 /* default: filter via can_id/can_mask */
497 return &d->rx[RX_FIL];
501 * can_rx_register - subscribe CAN frames from a specific interface
502 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
503 * @can_id: CAN identifier (see description)
504 * @mask: CAN mask (see description)
505 * @func: callback function on filter match
506 * @data: returned parameter for callback function
507 * @ident: string for calling module indentification
510 * Invokes the callback function with the received sk_buff and the given
511 * parameter 'data' on a matching receive filter. A filter matches, when
513 * <received_can_id> & mask == can_id & mask
515 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
516 * filter for error frames (CAN_ERR_FLAG bit set in mask).
518 * The provided pointer to the sk_buff is guaranteed to be valid as long as
519 * the callback function is running. The callback function must *not* free
520 * the given sk_buff while processing it's task. When the given sk_buff is
521 * needed after the end of the callback function it must be cloned inside
522 * the callback function with skb_clone().
526 * -ENOMEM on missing cache mem to create subscription entry
527 * -ENODEV unknown device
529 int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
530 void (*func)(struct sk_buff *, void *), void *data,
534 struct hlist_head *rl;
535 struct dev_rcv_lists *d;
538 /* insert new receiver (dev,canid,mask) -> (func,data) */
540 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
541 if (dev && dev->type != ARPHRD_CAN)
545 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
549 spin_lock(&can_rcvlists_lock);
551 d = find_dev_rcv_lists(dev);
553 rl = find_rcv_list(&can_id, &mask, d);
562 hlist_add_head_rcu(&r->list, rl);
565 can_pstats.rcv_entries++;
566 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
567 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
569 kmem_cache_free(rcv_cache, r);
573 spin_unlock(&can_rcvlists_lock);
577 EXPORT_SYMBOL(can_rx_register);
580 * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
582 static void can_rx_delete_device(struct rcu_head *rp)
584 struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
590 * can_rx_delete_receiver - rcu callback for single receiver entry removal
592 static void can_rx_delete_receiver(struct rcu_head *rp)
594 struct receiver *r = container_of(rp, struct receiver, rcu);
596 kmem_cache_free(rcv_cache, r);
600 * can_rx_unregister - unsubscribe CAN frames from a specific interface
601 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
602 * @can_id: CAN identifier
604 * @func: callback function on filter match
605 * @data: returned parameter for callback function
608 * Removes subscription entry depending on given (subscription) values.
610 void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
611 void (*func)(struct sk_buff *, void *), void *data)
613 struct receiver *r = NULL;
614 struct hlist_head *rl;
615 struct hlist_node *next;
616 struct dev_rcv_lists *d;
618 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
619 if (dev && dev->type != ARPHRD_CAN)
623 spin_lock(&can_rcvlists_lock);
625 d = find_dev_rcv_lists(dev);
627 printk(KERN_ERR "BUG: receive list not found for "
628 "dev %s, id %03X, mask %03X\n",
629 DNAME(dev), can_id, mask);
633 rl = find_rcv_list(&can_id, &mask, d);
636 * Search the receiver list for the item to delete. This should
637 * exist, since no receiver may be unregistered that hasn't
638 * been registered before.
641 hlist_for_each_entry_rcu(r, next, rl, list) {
642 if (r->can_id == can_id && r->mask == mask
643 && r->func == func && r->data == data)
648 * Check for bugs in CAN protocol implementations:
649 * If no matching list item was found, the list cursor variable next
650 * will be NULL, while r will point to the last item of the list.
654 printk(KERN_ERR "BUG: receive list entry not found for "
655 "dev %s, id %03X, mask %03X\n",
656 DNAME(dev), can_id, mask);
662 hlist_del_rcu(&r->list);
665 if (can_pstats.rcv_entries > 0)
666 can_pstats.rcv_entries--;
668 /* remove device structure requested by NETDEV_UNREGISTER */
669 if (d->remove_on_zero_entries && !d->entries) {
670 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
673 hlist_del_rcu(&d->list);
678 spin_unlock(&can_rcvlists_lock);
680 /* schedule the receiver item for deletion */
682 call_rcu(&r->rcu, can_rx_delete_receiver);
684 /* schedule the device structure for deletion */
686 call_rcu(&d->rcu, can_rx_delete_device);
688 EXPORT_SYMBOL(can_rx_unregister);
690 static inline void deliver(struct sk_buff *skb, struct receiver *r)
692 r->func(skb, r->data);
696 static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
699 struct hlist_node *n;
701 struct can_frame *cf = (struct can_frame *)skb->data;
702 canid_t can_id = cf->can_id;
707 if (can_id & CAN_ERR_FLAG) {
708 /* check for error frame entries only */
709 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
710 if (can_id & r->mask) {
718 /* check for unfiltered entries */
719 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
724 /* check for can_id/mask entries */
725 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
726 if ((can_id & r->mask) == r->can_id) {
732 /* check for inverted can_id/mask entries */
733 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
734 if ((can_id & r->mask) != r->can_id) {
740 /* check filterlists for single non-RTR can_ids */
741 if (can_id & CAN_RTR_FLAG)
744 if (can_id & CAN_EFF_FLAG) {
745 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
746 if (r->can_id == can_id) {
752 can_id &= CAN_SFF_MASK;
753 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
762 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
763 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
764 struct packet_type *pt, struct net_device *orig_dev)
766 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
767 struct packet_type *pt)
770 struct dev_rcv_lists *d;
771 struct can_frame *cf = (struct can_frame *)skb->data;
774 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
775 if (!net_eq(dev_net(dev), &init_net))
777 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
778 if (dev->nd_net != &init_net)
782 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
783 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
784 skb->len != sizeof(struct can_frame) ||
786 "PF_CAN: dropped non conform skbuf: "
787 "dev type %d, len %d, can_dlc %d\n",
788 dev->type, skb->len, cf->can_dlc))
791 BUG_ON(dev->type != ARPHRD_CAN ||
792 skb->len != sizeof(struct can_frame) ||
796 /* update statistics */
797 can_stats.rx_frames++;
798 can_stats.rx_frames_delta++;
802 /* deliver the packet to sockets listening on all devices */
803 matches = can_rcv_filter(&can_rx_alldev_list, skb);
805 /* find receive list for this device */
806 d = find_dev_rcv_lists(dev);
808 matches += can_rcv_filter(d, skb);
812 /* consume the skbuff allocated by the netdevice driver */
813 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
821 can_stats.matches_delta++;
824 return NET_RX_SUCCESS;
826 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
834 * af_can protocol functions
838 * can_proto_register - register CAN transport protocol
839 * @cp: pointer to CAN protocol structure
843 * -EINVAL invalid (out of range) protocol number
844 * -EBUSY protocol already in use
845 * -ENOBUF if proto_register() fails
847 int can_proto_register(struct can_proto *cp)
849 int proto = cp->protocol;
852 if (proto < 0 || proto >= CAN_NPROTO) {
853 printk(KERN_ERR "can: protocol number %d out of range\n",
858 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
859 err = proto_register(cp->prot, 0);
864 spin_lock(&proto_tab_lock);
865 if (proto_tab[proto]) {
866 printk(KERN_ERR "can: protocol %d already registered\n",
870 proto_tab[proto] = cp;
872 /* use generic ioctl function if not defined by module */
874 cp->ops->ioctl = can_ioctl;
876 spin_unlock(&proto_tab_lock);
878 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
880 proto_unregister(cp->prot);
885 EXPORT_SYMBOL(can_proto_register);
888 * can_proto_unregister - unregister CAN transport protocol
889 * @cp: pointer to CAN protocol structure
891 void can_proto_unregister(struct can_proto *cp)
893 int proto = cp->protocol;
895 spin_lock(&proto_tab_lock);
896 if (!proto_tab[proto]) {
897 printk(KERN_ERR "BUG: can: protocol %d is not registered\n",
900 proto_tab[proto] = NULL;
901 spin_unlock(&proto_tab_lock);
903 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
904 proto_unregister(cp->prot);
907 EXPORT_SYMBOL(can_proto_unregister);
910 * af_can notifier to create/remove CAN netdevice specific structs
912 static int can_notifier(struct notifier_block *nb, unsigned long msg,
915 struct net_device *dev = (struct net_device *)data;
916 struct dev_rcv_lists *d;
918 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
919 if (!net_eq(dev_net(dev), &init_net))
921 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
922 if (dev->nd_net != &init_net)
926 if (dev->type != ARPHRD_CAN)
931 case NETDEV_REGISTER:
934 * create new dev_rcv_lists for this device
936 * N.B. zeroing the struct is the correct initialization
937 * for the embedded hlist_head structs.
938 * Another list type, e.g. list_head, would require
939 * explicit initialization.
942 d = kzalloc(sizeof(*d), GFP_KERNEL);
945 "can: allocation of receive list failed\n");
950 spin_lock(&can_rcvlists_lock);
951 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
952 BUG_ON(dev->ml_priv);
955 hlist_add_head_rcu(&d->list, &can_rx_dev_list);
956 spin_unlock(&can_rcvlists_lock);
960 case NETDEV_UNREGISTER:
961 spin_lock(&can_rcvlists_lock);
963 d = find_dev_rcv_lists(dev);
966 d->remove_on_zero_entries = 1;
969 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
972 hlist_del_rcu(&d->list);
975 printk(KERN_ERR "can: notifier: receive list not "
976 "found for dev %s\n", dev->name);
978 spin_unlock(&can_rcvlists_lock);
981 call_rcu(&d->rcu, can_rx_delete_device);
990 * af_can module init/exit functions
993 static struct packet_type can_packet __read_mostly = {
994 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
995 .type = cpu_to_be16(ETH_P_CAN),
997 .type = __constant_htons(ETH_P_CAN),
1003 static struct net_proto_family can_family_ops __read_mostly = {
1005 .create = can_create,
1006 .owner = THIS_MODULE,
1009 /* notifier block for netdevice event */
1010 static struct notifier_block can_netdev_notifier __read_mostly = {
1011 .notifier_call = can_notifier,
1014 static __init int can_init(void)
1018 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
1019 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
1022 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
1029 * Insert can_rx_alldev_list for reception on all devices.
1030 * This struct is zero initialized which is correct for the
1031 * embedded hlist heads, the dev pointer, and the entries counter.
1034 spin_lock(&can_rcvlists_lock);
1035 hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
1036 spin_unlock(&can_rcvlists_lock);
1039 /* the statistics are updated every second (timer triggered) */
1040 setup_timer(&can_stattimer, can_stat_update, 0);
1041 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
1043 can_stattimer.function = NULL;
1047 /* protocol register */
1048 sock_register(&can_family_ops);
1049 register_netdevice_notifier(&can_netdev_notifier);
1050 dev_add_pack(&can_packet);
1055 static __exit void can_exit(void)
1057 struct dev_rcv_lists *d;
1058 struct hlist_node *n, *next;
1061 del_timer(&can_stattimer);
1065 /* protocol unregister */
1066 dev_remove_pack(&can_packet);
1067 unregister_netdevice_notifier(&can_netdev_notifier);
1068 sock_unregister(PF_CAN);
1070 /* remove can_rx_dev_list */
1071 spin_lock(&can_rcvlists_lock);
1072 hlist_del(&can_rx_alldev_list.list);
1073 hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
1074 hlist_del(&d->list);
1076 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
1077 d->dev->ml_priv = NULL;
1081 spin_unlock(&can_rcvlists_lock);
1083 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
1084 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1087 kmem_cache_destroy(rcv_cache);
1090 module_init(can_init);
1091 module_exit(can_exit);