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_MUTEX(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 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);
132 EXPORT_SYMBOL(can_ioctl);
134 static void can_sock_destruct(struct sock *sk)
136 skb_queue_purge(&sk->sk_receive_queue);
137 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
139 kfree(sk->sk_protinfo);
143 static struct can_proto *can_try_module_get(int protocol)
145 struct can_proto *cp;
148 cp = rcu_dereference(proto_tab[protocol]);
149 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
150 if (cp && !try_module_get(cp->prot->owner))
153 if (cp && !try_module_get(cp->owner))
161 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)
162 static int can_create(struct net *net, struct socket *sock, int protocol, int kern)
163 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
164 static int can_create(struct net *net, struct socket *sock, int protocol)
166 static int can_create(struct socket *sock, int protocol)
170 struct can_proto *cp;
173 sock->state = SS_UNCONNECTED;
175 if (protocol < 0 || protocol >= CAN_NPROTO)
178 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
179 if (net != &init_net)
180 return -EAFNOSUPPORT;
183 cp = can_try_module_get(protocol);
185 #ifdef CONFIG_MODULES
187 /* try to load protocol module if kernel is modular */
189 err = request_module("can-proto-%d", protocol);
192 * In case of error we only print a message but don't
193 * return the error code immediately. Below we will
194 * return -EPROTONOSUPPORT
196 if (err && printk_ratelimit())
197 printk(KERN_ERR "can: request_module "
198 "(can-proto-%d) failed.\n", protocol);
200 cp = can_try_module_get(protocol);
204 /* check for available protocol and correct usage */
207 return -EPROTONOSUPPORT;
209 if (cp->type != sock->type) {
214 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33)
215 if (cp->capability >= 0 && !capable(cp->capability)) {
222 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
223 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
224 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
225 sk = sk_alloc(PF_CAN, GFP_KERNEL, cp->prot, 1);
227 sk = sk_alloc(PF_CAN, GFP_KERNEL, 1, 0);
234 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
236 sk->sk_protinfo = kmalloc(cp->obj_size, GFP_KERNEL);
237 if (!sk->sk_protinfo) {
243 sk_set_owner(sk, proto_tab[protocol]->owner);
246 sock_init_data(sock, sk);
247 sk->sk_destruct = can_sock_destruct;
249 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
250 if (sk->sk_prot->init)
251 err = sk->sk_prot->init(sk);
258 /* release sk on errors */
264 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
265 module_put(cp->prot->owner);
267 module_put(cp->owner);
277 * can_send - transmit a CAN frame (optional with local loopback)
278 * @skb: pointer to socket buffer with CAN frame in data section
279 * @loop: loopback for listeners on local CAN sockets (recommended default!)
281 * Due to the loopback this routine must not be called from hardirq context.
285 * -ENETDOWN when the selected interface is down
286 * -ENOBUFS on full driver queue (see net_xmit_errno())
287 * -ENOMEM when local loopback failed at calling skb_clone()
288 * -EPERM when trying to send on a non-CAN interface
289 * -EINVAL when the skb->data does not contain a valid CAN frame
291 int can_send(struct sk_buff *skb, int loop)
293 struct sk_buff *newskb = NULL;
294 struct can_frame *cf = (struct can_frame *)skb->data;
297 if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
302 if (skb->dev->type != ARPHRD_CAN) {
307 if (!(skb->dev->flags & IFF_UP)) {
312 skb->protocol = htons(ETH_P_CAN);
313 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
314 skb_reset_network_header(skb);
315 skb_reset_transport_header(skb);
317 skb->nh.raw = skb->data;
318 skb->h.raw = skb->data;
322 /* local loopback of sent CAN frames */
324 /* indication for the CAN driver: do loopback */
325 skb->pkt_type = PACKET_LOOPBACK;
328 * The reference to the originating sock may be required
329 * by the receiving socket to check whether the frame is
330 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
331 * Therefore we have to ensure that skb->sk remains the
332 * reference to the originating sock by restoring skb->sk
333 * after each skb_clone() or skb_orphan() usage.
336 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
337 #define IFF_ECHO IFF_LOOPBACK
339 if (!(skb->dev->flags & IFF_ECHO)) {
341 * If the interface is not capable to do loopback
342 * itself, we do it here.
344 newskb = skb_clone(skb, GFP_ATOMIC);
350 newskb->sk = skb->sk;
351 newskb->ip_summed = CHECKSUM_UNNECESSARY;
352 newskb->pkt_type = PACKET_BROADCAST;
355 /* indication for the CAN driver: no loopback required */
356 skb->pkt_type = PACKET_HOST;
359 /* send to netdevice */
360 err = dev_queue_xmit(skb);
362 err = net_xmit_errno(err);
365 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)
366 /* kfree_skb() does not check for !NULL on older kernels */
378 /* update statistics */
379 can_stats.tx_frames++;
380 can_stats.tx_frames_delta++;
384 EXPORT_SYMBOL(can_send);
390 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
391 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
394 * find receive list for this device
396 * Since 2.6.26 a new "midlevel private" ml_priv pointer has been
397 * introduced in struct net_device. We use this pointer to omit the
398 * linear walk through the can_rx_dev_list. A similar speedup has been
399 * queued for 2.6.34 mainline but using the new netdev_rcu lists.
400 * Therefore the can_rx_dev_list is still needed (e.g. in proc.c)
403 /* dev == NULL is the indicator for the 'all' filterlist */
405 return &can_rx_alldev_list;
407 return (struct dev_rcv_lists *)dev->ml_priv;
410 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
412 struct dev_rcv_lists *d = NULL;
413 struct hlist_node *n;
416 * find receive list for this device
418 * The hlist_for_each_entry*() macros curse through the list
419 * using the pointer variable n and set d to the containing
420 * struct in each list iteration. Therefore, after list
421 * iteration, d is unmodified when the list is empty, and it
422 * points to last list element, when the list is non-empty
423 * but no match in the loop body is found. I.e. d is *not*
424 * NULL when no match is found. We can, however, use the
425 * cursor variable n to decide if a match was found.
428 hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
438 * find_rcv_list - determine optimal filterlist inside device filter struct
439 * @can_id: pointer to CAN identifier of a given can_filter
440 * @mask: pointer to CAN mask of a given can_filter
441 * @d: pointer to the device filter struct
444 * Returns the optimal filterlist to reduce the filter handling in the
445 * receive path. This function is called by service functions that need
446 * to register or unregister a can_filter in the filter lists.
448 * A filter matches in general, when
450 * <received_can_id> & mask == can_id & mask
452 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
453 * relevant bits for the filter.
455 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
456 * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
457 * there is a special filterlist and a special rx path filter handling.
460 * Pointer to optimal filterlist for the given can_id/mask pair.
461 * Constistency checked mask.
462 * Reduced can_id to have a preprocessed filter compare value.
464 static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
465 struct dev_rcv_lists *d)
467 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
469 /* filter for error frames in extra filterlist */
470 if (*mask & CAN_ERR_FLAG) {
471 /* clear CAN_ERR_FLAG in filter entry */
472 *mask &= CAN_ERR_MASK;
473 return &d->rx[RX_ERR];
476 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
478 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
480 /* ensure valid values in can_mask for 'SFF only' frame filtering */
481 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
482 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
484 /* reduce condition testing at receive time */
487 /* inverse can_id/can_mask filter */
489 return &d->rx[RX_INV];
491 /* mask == 0 => no condition testing at receive time */
493 return &d->rx[RX_ALL];
495 /* extra filterlists for the subscription of a single non-RTR can_id */
496 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS)
497 && !(*can_id & CAN_RTR_FLAG)) {
499 if (*can_id & CAN_EFF_FLAG) {
500 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
501 /* RFC: a future use-case for hash-tables? */
502 return &d->rx[RX_EFF];
505 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
506 return &d->rx_sff[*can_id];
510 /* default: filter via can_id/can_mask */
511 return &d->rx[RX_FIL];
515 * can_rx_register - subscribe CAN frames from a specific interface
516 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
517 * @can_id: CAN identifier (see description)
518 * @mask: CAN mask (see description)
519 * @func: callback function on filter match
520 * @data: returned parameter for callback function
521 * @ident: string for calling module indentification
524 * Invokes the callback function with the received sk_buff and the given
525 * parameter 'data' on a matching receive filter. A filter matches, when
527 * <received_can_id> & mask == can_id & mask
529 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
530 * filter for error frames (CAN_ERR_FLAG bit set in mask).
532 * The provided pointer to the sk_buff is guaranteed to be valid as long as
533 * the callback function is running. The callback function must *not* free
534 * the given sk_buff while processing it's task. When the given sk_buff is
535 * needed after the end of the callback function it must be cloned inside
536 * the callback function with skb_clone().
540 * -ENOMEM on missing cache mem to create subscription entry
541 * -ENODEV unknown device
543 int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
544 void (*func)(struct sk_buff *, void *), void *data,
548 struct hlist_head *rl;
549 struct dev_rcv_lists *d;
552 /* insert new receiver (dev,canid,mask) -> (func,data) */
554 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
555 if (dev && dev->type != ARPHRD_CAN)
559 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
563 spin_lock(&can_rcvlists_lock);
565 d = find_dev_rcv_lists(dev);
567 rl = find_rcv_list(&can_id, &mask, d);
576 hlist_add_head_rcu(&r->list, rl);
579 can_pstats.rcv_entries++;
580 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
581 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
583 kmem_cache_free(rcv_cache, r);
587 spin_unlock(&can_rcvlists_lock);
591 EXPORT_SYMBOL(can_rx_register);
594 * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
596 static void can_rx_delete_device(struct rcu_head *rp)
598 struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
604 * can_rx_delete_receiver - rcu callback for single receiver entry removal
606 static void can_rx_delete_receiver(struct rcu_head *rp)
608 struct receiver *r = container_of(rp, struct receiver, rcu);
610 kmem_cache_free(rcv_cache, r);
614 * can_rx_unregister - unsubscribe CAN frames from a specific interface
615 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
616 * @can_id: CAN identifier
618 * @func: callback function on filter match
619 * @data: returned parameter for callback function
622 * Removes subscription entry depending on given (subscription) values.
624 void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
625 void (*func)(struct sk_buff *, void *), void *data)
627 struct receiver *r = NULL;
628 struct hlist_head *rl;
629 struct hlist_node *next;
630 struct dev_rcv_lists *d;
632 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
633 if (dev && dev->type != ARPHRD_CAN)
637 spin_lock(&can_rcvlists_lock);
639 d = find_dev_rcv_lists(dev);
641 printk(KERN_ERR "BUG: receive list not found for "
642 "dev %s, id %03X, mask %03X\n",
643 DNAME(dev), can_id, mask);
647 rl = find_rcv_list(&can_id, &mask, d);
650 * Search the receiver list for the item to delete. This should
651 * exist, since no receiver may be unregistered that hasn't
652 * been registered before.
655 hlist_for_each_entry_rcu(r, next, rl, list) {
656 if (r->can_id == can_id && r->mask == mask
657 && r->func == func && r->data == data)
662 * Check for bugs in CAN protocol implementations:
663 * If no matching list item was found, the list cursor variable next
664 * will be NULL, while r will point to the last item of the list.
668 printk(KERN_ERR "BUG: receive list entry not found for "
669 "dev %s, id %03X, mask %03X\n",
670 DNAME(dev), can_id, mask);
676 hlist_del_rcu(&r->list);
679 if (can_pstats.rcv_entries > 0)
680 can_pstats.rcv_entries--;
682 /* remove device structure requested by NETDEV_UNREGISTER */
683 if (d->remove_on_zero_entries && !d->entries) {
684 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
687 hlist_del_rcu(&d->list);
692 spin_unlock(&can_rcvlists_lock);
694 /* schedule the receiver item for deletion */
696 call_rcu(&r->rcu, can_rx_delete_receiver);
698 /* schedule the device structure for deletion */
700 call_rcu(&d->rcu, can_rx_delete_device);
702 EXPORT_SYMBOL(can_rx_unregister);
704 static inline void deliver(struct sk_buff *skb, struct receiver *r)
706 r->func(skb, r->data);
710 static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
713 struct hlist_node *n;
715 struct can_frame *cf = (struct can_frame *)skb->data;
716 canid_t can_id = cf->can_id;
721 if (can_id & CAN_ERR_FLAG) {
722 /* check for error frame entries only */
723 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
724 if (can_id & r->mask) {
732 /* check for unfiltered entries */
733 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
738 /* check for can_id/mask entries */
739 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
740 if ((can_id & r->mask) == r->can_id) {
746 /* check for inverted can_id/mask entries */
747 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
748 if ((can_id & r->mask) != r->can_id) {
754 /* check filterlists for single non-RTR can_ids */
755 if (can_id & CAN_RTR_FLAG)
758 if (can_id & CAN_EFF_FLAG) {
759 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
760 if (r->can_id == can_id) {
766 can_id &= CAN_SFF_MASK;
767 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
776 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
777 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
778 struct packet_type *pt, struct net_device *orig_dev)
780 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
781 struct packet_type *pt)
784 struct dev_rcv_lists *d;
785 struct can_frame *cf = (struct can_frame *)skb->data;
788 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
789 if (!net_eq(dev_net(dev), &init_net))
791 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
792 if (dev->nd_net != &init_net)
796 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
797 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
798 skb->len != sizeof(struct can_frame) ||
800 "PF_CAN: dropped non conform skbuf: "
801 "dev type %d, len %d, can_dlc %d\n",
802 dev->type, skb->len, cf->can_dlc))
805 BUG_ON(dev->type != ARPHRD_CAN ||
806 skb->len != sizeof(struct can_frame) ||
810 /* update statistics */
811 can_stats.rx_frames++;
812 can_stats.rx_frames_delta++;
816 /* deliver the packet to sockets listening on all devices */
817 matches = can_rcv_filter(&can_rx_alldev_list, skb);
819 /* find receive list for this device */
820 d = find_dev_rcv_lists(dev);
822 matches += can_rcv_filter(d, skb);
826 /* consume the skbuff allocated by the netdevice driver */
827 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
835 can_stats.matches_delta++;
838 return NET_RX_SUCCESS;
840 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
848 * af_can protocol functions
852 * can_proto_register - register CAN transport protocol
853 * @cp: pointer to CAN protocol structure
857 * -EINVAL invalid (out of range) protocol number
858 * -EBUSY protocol already in use
859 * -ENOBUF if proto_register() fails
861 int can_proto_register(struct can_proto *cp)
863 int proto = cp->protocol;
866 if (proto < 0 || proto >= CAN_NPROTO) {
867 printk(KERN_ERR "can: protocol number %d out of range\n",
872 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
873 err = proto_register(cp->prot, 0);
878 mutex_lock(&proto_tab_lock);
880 if (proto_tab[proto]) {
881 printk(KERN_ERR "can: protocol %d already registered\n",
885 rcu_assign_pointer(proto_tab[proto], cp);
887 mutex_unlock(&proto_tab_lock);
889 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
891 proto_unregister(cp->prot);
896 EXPORT_SYMBOL(can_proto_register);
899 * can_proto_unregister - unregister CAN transport protocol
900 * @cp: pointer to CAN protocol structure
902 void can_proto_unregister(struct can_proto *cp)
904 int proto = cp->protocol;
906 mutex_lock(&proto_tab_lock);
907 BUG_ON(proto_tab[proto] != cp);
908 rcu_assign_pointer(proto_tab[proto], NULL);
909 mutex_unlock(&proto_tab_lock);
913 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
914 proto_unregister(cp->prot);
917 EXPORT_SYMBOL(can_proto_unregister);
920 * af_can notifier to create/remove CAN netdevice specific structs
922 static int can_notifier(struct notifier_block *nb, unsigned long msg,
925 struct net_device *dev = (struct net_device *)data;
926 struct dev_rcv_lists *d;
928 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
929 if (!net_eq(dev_net(dev), &init_net))
931 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
932 if (dev->nd_net != &init_net)
936 if (dev->type != ARPHRD_CAN)
941 case NETDEV_REGISTER:
944 * create new dev_rcv_lists for this device
946 * N.B. zeroing the struct is the correct initialization
947 * for the embedded hlist_head structs.
948 * Another list type, e.g. list_head, would require
949 * explicit initialization.
952 d = kzalloc(sizeof(*d), GFP_KERNEL);
955 "can: allocation of receive list failed\n");
960 spin_lock(&can_rcvlists_lock);
961 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
962 BUG_ON(dev->ml_priv);
965 hlist_add_head_rcu(&d->list, &can_rx_dev_list);
966 spin_unlock(&can_rcvlists_lock);
970 case NETDEV_UNREGISTER:
971 spin_lock(&can_rcvlists_lock);
973 d = find_dev_rcv_lists(dev);
976 d->remove_on_zero_entries = 1;
979 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
982 hlist_del_rcu(&d->list);
985 printk(KERN_ERR "can: notifier: receive list not "
986 "found for dev %s\n", dev->name);
988 spin_unlock(&can_rcvlists_lock);
991 call_rcu(&d->rcu, can_rx_delete_device);
1000 * af_can module init/exit functions
1003 static struct packet_type can_packet __read_mostly = {
1004 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
1005 .type = cpu_to_be16(ETH_P_CAN),
1007 .type = __constant_htons(ETH_P_CAN),
1013 static struct net_proto_family can_family_ops __read_mostly = {
1015 .create = can_create,
1016 .owner = THIS_MODULE,
1019 /* notifier block for netdevice event */
1020 static struct notifier_block can_netdev_notifier __read_mostly = {
1021 .notifier_call = can_notifier,
1024 static __init int can_init(void)
1028 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
1029 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
1032 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
1039 * Insert can_rx_alldev_list for reception on all devices.
1040 * This struct is zero initialized which is correct for the
1041 * embedded hlist heads, the dev pointer, and the entries counter.
1044 spin_lock(&can_rcvlists_lock);
1045 hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
1046 spin_unlock(&can_rcvlists_lock);
1049 /* the statistics are updated every second (timer triggered) */
1050 setup_timer(&can_stattimer, can_stat_update, 0);
1051 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
1053 can_stattimer.function = NULL;
1057 /* protocol register */
1058 sock_register(&can_family_ops);
1059 register_netdevice_notifier(&can_netdev_notifier);
1060 dev_add_pack(&can_packet);
1065 static __exit void can_exit(void)
1067 struct dev_rcv_lists *d;
1068 struct hlist_node *n, *next;
1071 del_timer(&can_stattimer);
1075 /* protocol unregister */
1076 dev_remove_pack(&can_packet);
1077 unregister_netdevice_notifier(&can_netdev_notifier);
1078 sock_unregister(PF_CAN);
1080 /* remove can_rx_dev_list */
1081 spin_lock(&can_rcvlists_lock);
1082 hlist_del(&can_rx_alldev_list.list);
1083 hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
1084 hlist_del(&d->list);
1086 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
1087 d->dev->ml_priv = NULL;
1091 spin_unlock(&can_rcvlists_lock);
1093 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
1094 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1097 kmem_cache_destroy(rcv_cache);
1100 module_init(can_init);
1101 module_exit(can_exit);