[linux-2.6-block.git] / drivers / connector / connector.c

/*
 * 	connector.c
 * 
 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
 * All rights reserved.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/moduleparam.h>
#include <linux/connector.h>
#include <linux/mutex.h>

#include <net/sock.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
MODULE_DESCRIPTION("Generic userspace <-> kernelspace connector.");

static u32 cn_idx = CN_IDX_CONNECTOR;
static u32 cn_val = CN_VAL_CONNECTOR;

module_param(cn_idx, uint, 0);
module_param(cn_val, uint, 0);
MODULE_PARM_DESC(cn_idx, "Connector's main device idx.");
MODULE_PARM_DESC(cn_val, "Connector's main device val.");

static DEFINE_MUTEX(notify_lock);
static LIST_HEAD(notify_list);

static struct cn_dev cdev;

int cn_already_initialized = 0;

/*
 * msg->seq and msg->ack are used to determine message genealogy.
 * When someone sends message it puts there locally unique sequence
 * and random acknowledge numbers.  Sequence number may be copied into
 * nlmsghdr->nlmsg_seq too.
 *
 * Sequence number is incremented with each message to be sent.
 *
 * If we expect reply to our message then the sequence number in
 * received message MUST be the same as in original message, and
 * acknowledge number MUST be the same + 1.
 *
 * If we receive a message and its sequence number is not equal to the
 * one we are expecting then it is a new message.
 *
 * If we receive a message and its sequence number is the same as one
 * we are expecting but it's acknowledgement number is not equal to
 * the acknowledgement number in the original message + 1, then it is
 * a new message.
 *
 */
int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
{
	struct cn_callback_entry *__cbq;
	unsigned int size;
	struct sk_buff *skb;
	struct nlmsghdr *nlh;
	struct cn_msg *data;
	struct cn_dev *dev = &cdev;
	u32 group = 0;
	int found = 0;

	if (!__group) {
		spin_lock_bh(&dev->cbdev->queue_lock);
		list_for_each_entry(__cbq, &dev->cbdev->queue_list,
				    callback_entry) {
			if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
				found = 1;
				group = __cbq->group;
			}
		}
		spin_unlock_bh(&dev->cbdev->queue_lock);

		if (!found)
			return -ENODEV;
	} else {
		group = __group;
	}

	if (!netlink_has_listeners(dev->nls, group))
		return -ESRCH;

	size = NLMSG_SPACE(sizeof(*msg) + msg->len);

	skb = alloc_skb(size, gfp_mask);
	if (!skb)
		return -ENOMEM;

	nlh = NLMSG_PUT(skb, 0, msg->seq, NLMSG_DONE, size - sizeof(*nlh));

	data = NLMSG_DATA(nlh);

	memcpy(data, msg, sizeof(*data) + msg->len);

	NETLINK_CB(skb).dst_group = group;

	return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);

nlmsg_failure:
	kfree_skb(skb);
	return -EINVAL;
}
EXPORT_SYMBOL_GPL(cn_netlink_send);

/*
 * Callback helper - queues work and setup destructor for given data.
 */
static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), void *data)
{
	struct cn_callback_entry *__cbq;
	struct cn_dev *dev = &cdev;
	int err = -ENODEV;

	spin_lock_bh(&dev->cbdev->queue_lock);
	list_for_each_entry(__cbq, &dev->cbdev->queue_list, callback_entry) {
		if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
			if (likely(!test_bit(WORK_STRUCT_PENDING,
					     &__cbq->work.work.management) &&
					__cbq->data.ddata == NULL)) {
				__cbq->data.callback_priv = msg;

				__cbq->data.ddata = data;
				__cbq->data.destruct_data = destruct_data;

				if (queue_delayed_work(
					    dev->cbdev->cn_queue,
					    &__cbq->work, 0))
					err = 0;
			} else {
				struct cn_callback_data *d;
				
				__cbq = kzalloc(sizeof(*__cbq), GFP_ATOMIC);
				if (__cbq) {
					d = &__cbq->data;
					d->callback_priv = msg;
					d->callback = __cbq->data.callback;
					d->ddata = data;
					d->destruct_data = destruct_data;
					d->free = __cbq;

					INIT_DELAYED_WORK(&__cbq->work,
							  &cn_queue_wrapper);
					
					if (queue_delayed_work(
						    dev->cbdev->cn_queue,
						    &__cbq->work, 0))
						err = 0;
					else {
						kfree(__cbq);
						err = -EINVAL;
					}
				} else
					err = -ENOMEM;
			}
			break;
		}
	}
	spin_unlock_bh(&dev->cbdev->queue_lock);

	return err;
}

/*
 * Skb receive helper - checks skb and msg size and calls callback
 * helper.
 */
static int __cn_rx_skb(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	u32 pid, uid, seq, group;
	struct cn_msg *msg;

	pid = NETLINK_CREDS(skb)->pid;
	uid = NETLINK_CREDS(skb)->uid;
	seq = nlh->nlmsg_seq;
	group = NETLINK_CB((skb)).dst_group;
	msg = NLMSG_DATA(nlh);

	return cn_call_callback(msg, (void (*)(void *))kfree_skb, skb);
}

/*
 * Main netlink receiving function.
 *
 * It checks skb and netlink header sizes and calls the skb receive
 * helper with a shared skb.
 */
static void cn_rx_skb(struct sk_buff *__skb)
{
	struct nlmsghdr *nlh;
	u32 len;
	int err;
	struct sk_buff *skb;

	skb = skb_get(__skb);

	if (skb->len >= NLMSG_SPACE(0)) {
		nlh = (struct nlmsghdr *)skb->data;

		if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
		    skb->len < nlh->nlmsg_len ||
		    nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
			kfree_skb(skb);
			goto out;
		}

		len = NLMSG_ALIGN(nlh->nlmsg_len);
		if (len > skb->len)
			len = skb->len;

		err = __cn_rx_skb(skb, nlh);
		if (err < 0)
			kfree_skb(skb);
	}

out:
	kfree_skb(__skb);
}

/*
 * Netlink socket input callback - dequeues the skbs and calls the
 * main netlink receiving function.
 */
static void cn_input(struct sock *sk, int len)
{
	struct sk_buff *skb;

	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL)
		cn_rx_skb(skb);
}

/*
 * Notification routing.
 *
 * Gets id and checks if there are notification request for it's idx
 * and val.  If there are such requests notify the listeners with the
 * given notify event.
 *
 */
static void cn_notify(struct cb_id *id, u32 notify_event)
{
	struct cn_ctl_entry *ent;

	mutex_lock(&notify_lock);
	list_for_each_entry(ent, &notify_list, notify_entry) {
		int i;
		struct cn_notify_req *req;
		struct cn_ctl_msg *ctl = ent->msg;
		int idx_found, val_found;

		idx_found = val_found = 0;

		req = (struct cn_notify_req *)ctl->data;
		for (i = 0; i < ctl->idx_notify_num; ++i, ++req) {
			if (id->idx >= req->first && 
					id->idx < req->first + req->range) {
				idx_found = 1;
				break;
			}
		}

		for (i = 0; i < ctl->val_notify_num; ++i, ++req) {
			if (id->val >= req->first && 
					id->val < req->first + req->range) {
				val_found = 1;
				break;
			}
		}

		if (idx_found && val_found) {
			struct cn_msg m = { .ack = notify_event, };

			memcpy(&m.id, id, sizeof(m.id));
			cn_netlink_send(&m, ctl->group, GFP_KERNEL);
		}
	}
	mutex_unlock(&notify_lock);
}

/*
 * Callback add routing - adds callback with given ID and name.
 * If there is registered callback with the same ID it will not be added.
 *
 * May sleep.
 */
int cn_add_callback(struct cb_id *id, char *name, void (*callback)(void *))
{
	int err;
	struct cn_dev *dev = &cdev;

	if (!cn_already_initialized)
		return -EAGAIN;

	err = cn_queue_add_callback(dev->cbdev, name, id, callback);
	if (err)
		return err;

	cn_notify(id, 0);

	return 0;
}
EXPORT_SYMBOL_GPL(cn_add_callback);

/*
 * Callback remove routing - removes callback
 * with given ID.
 * If there is no registered callback with given
 * ID nothing happens.
 *
 * May sleep while waiting for reference counter to become zero.
 */
void cn_del_callback(struct cb_id *id)
{
	struct cn_dev *dev = &cdev;

	cn_queue_del_callback(dev->cbdev, id);
	cn_notify(id, 1);
}
EXPORT_SYMBOL_GPL(cn_del_callback);

/*
 * Checks two connector's control messages to be the same.
 * Returns 1 if they are the same or if the first one is corrupted.
 */
static int cn_ctl_msg_equals(struct cn_ctl_msg *m1, struct cn_ctl_msg *m2)
{
	int i;
	struct cn_notify_req *req1, *req2;

	if (m1->idx_notify_num != m2->idx_notify_num)
		return 0;

	if (m1->val_notify_num != m2->val_notify_num)
		return 0;

	if (m1->len != m2->len)
		return 0;

	if ((m1->idx_notify_num + m1->val_notify_num) * sizeof(*req1) !=
	    m1->len)
		return 1;

	req1 = (struct cn_notify_req *)m1->data;
	req2 = (struct cn_notify_req *)m2->data;

	for (i = 0; i < m1->idx_notify_num; ++i) {
		if (req1->first != req2->first || req1->range != req2->range)
			return 0;
		req1++;
		req2++;
	}

	for (i = 0; i < m1->val_notify_num; ++i) {
		if (req1->first != req2->first || req1->range != req2->range)
			return 0;
		req1++;
		req2++;
	}

	return 1;
}

/*
 * Main connector device's callback.
 *
 * Used for notification of a request's processing.
 */
static void cn_callback(void *data)
{
	struct cn_msg *msg = data;
	struct cn_ctl_msg *ctl;
	struct cn_ctl_entry *ent;
	u32 size;

	if (msg->len < sizeof(*ctl))
		return;

	ctl = (struct cn_ctl_msg *)msg->data;

	size = (sizeof(*ctl) + ((ctl->idx_notify_num +
				 ctl->val_notify_num) *
				sizeof(struct cn_notify_req)));

	if (msg->len != size)
		return;

	if (ctl->len + sizeof(*ctl) != msg->len)
		return;

	/*
	 * Remove notification.
	 */
	if (ctl->group == 0) {
		struct cn_ctl_entry *n;

		mutex_lock(&notify_lock);
		list_for_each_entry_safe(ent, n, &notify_list, notify_entry) {
			if (cn_ctl_msg_equals(ent->msg, ctl)) {
				list_del(&ent->notify_entry);
				kfree(ent);
			}
		}
		mutex_unlock(&notify_lock);

		return;
	}

	size += sizeof(*ent);

	ent = kzalloc(size, GFP_KERNEL);
	if (!ent)
		return;

	ent->msg = (struct cn_ctl_msg *)(ent + 1);

	memcpy(ent->msg, ctl, size - sizeof(*ent));

	mutex_lock(&notify_lock);
	list_add(&ent->notify_entry, &notify_list);
	mutex_unlock(&notify_lock);
}

static int __devinit cn_init(void)
{
	struct cn_dev *dev = &cdev;
	int err;

	dev->input = cn_input;
	dev->id.idx = cn_idx;
	dev->id.val = cn_val;

	dev->nls = netlink_kernel_create(NETLINK_CONNECTOR,
					 CN_NETLINK_USERS + 0xf,
					 dev->input, THIS_MODULE);
	if (!dev->nls)
		return -EIO;

	dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
	if (!dev->cbdev) {
		if (dev->nls->sk_socket)
			sock_release(dev->nls->sk_socket);
		return -EINVAL;
	}
	
	cn_already_initialized = 1;

	err = cn_add_callback(&dev->id, "connector", &cn_callback);
	if (err) {
		cn_already_initialized = 0;
		cn_queue_free_dev(dev->cbdev);
		if (dev->nls->sk_socket)
			sock_release(dev->nls->sk_socket);
		return -EINVAL;
	}

	return 0;
}

static void __devexit cn_fini(void)
{
	struct cn_dev *dev = &cdev;

	cn_already_initialized = 0;

	cn_del_callback(&dev->id);
	cn_queue_free_dev(dev->cbdev);
	if (dev->nls->sk_socket)
		sock_release(dev->nls->sk_socket);
}

subsys_initcall(cn_init);
module_exit(cn_fini);
Commit	Line	Data
7672d0b5 EP	1	/*
	2	* connector.c
	3	*
	4	* 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
	5	* All rights reserved.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*/
	21
	22	#include <linux/kernel.h>
	23	#include <linux/module.h>
	24	#include <linux/list.h>
	25	#include <linux/skbuff.h>
	26	#include <linux/netlink.h>
	27	#include <linux/moduleparam.h>
	28	#include <linux/connector.h>
8ed965d6	29	#include <linux/mutex.h>
7672d0b5 EP	30
	31	#include <net/sock.h>
	32
	33	MODULE_LICENSE("GPL");
	34	MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
	35	MODULE_DESCRIPTION("Generic userspace <-> kernelspace connector.");
	36
	37	static u32 cn_idx = CN_IDX_CONNECTOR;
	38	static u32 cn_val = CN_VAL_CONNECTOR;
	39
	40	module_param(cn_idx, uint, 0);
	41	module_param(cn_val, uint, 0);
	42	MODULE_PARM_DESC(cn_idx, "Connector's main device idx.");
	43	MODULE_PARM_DESC(cn_val, "Connector's main device val.");
	44
8ed965d6	45	static DEFINE_MUTEX(notify_lock);
7672d0b5 EP	46	static LIST_HEAD(notify_list);
	47
	48	static struct cn_dev cdev;
	49
	50	int cn_already_initialized = 0;
	51
	52	/*
	53	* msg->seq and msg->ack are used to determine message genealogy.
	54	* When someone sends message it puts there locally unique sequence
	55	* and random acknowledge numbers. Sequence number may be copied into
	56	* nlmsghdr->nlmsg_seq too.
	57	*
	58	* Sequence number is incremented with each message to be sent.
	59	*
	60	* If we expect reply to our message then the sequence number in
	61	* received message MUST be the same as in original message, and
	62	* acknowledge number MUST be the same + 1.
	63	*
	64	* If we receive a message and its sequence number is not equal to the
	65	* one we are expecting then it is a new message.
	66	*
	67	* If we receive a message and its sequence number is the same as one
	68	* we are expecting but it's acknowledgement number is not equal to
	69	* the acknowledgement number in the original message + 1, then it is
	70	* a new message.
	71	*
	72	*/
dd0fc66f	73	int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
7672d0b5 EP	74	{
	75	struct cn_callback_entry *__cbq;
	76	unsigned int size;
	77	struct sk_buff *skb;
	78	struct nlmsghdr *nlh;
	79	struct cn_msg *data;
	80	struct cn_dev *dev = &cdev;
	81	u32 group = 0;
	82	int found = 0;
	83
	84	if (!__group) {
	85	spin_lock_bh(&dev->cbdev->queue_lock);
	86	list_for_each_entry(__cbq, &dev->cbdev->queue_list,
	87	callback_entry) {
acd042bb	88	if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
7672d0b5 EP	89	found = 1;
	90	group = __cbq->group;
	91	}
	92	}
	93	spin_unlock_bh(&dev->cbdev->queue_lock);
	94
	95	if (!found)
	96	return -ENODEV;
	97	} else {
	98	group = __group;
	99	}
	100
b191ba0d EP	101	if (!netlink_has_listeners(dev->nls, group))
	102	return -ESRCH;
	103
7672d0b5 EP	104	size = NLMSG_SPACE(sizeof(*msg) + msg->len);
	105
	106	skb = alloc_skb(size, gfp_mask);
	107	if (!skb)
	108	return -ENOMEM;
	109
	110	nlh = NLMSG_PUT(skb, 0, msg->seq, NLMSG_DONE, size - sizeof(*nlh));
	111
	112	data = NLMSG_DATA(nlh);
	113
	114	memcpy(data, msg, sizeof(*data) + msg->len);
	115
	116	NETLINK_CB(skb).dst_group = group;
	117
b191ba0d	118	return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
7672d0b5 EP	119
	120	nlmsg_failure:
	121	kfree_skb(skb);
	122	return -EINVAL;
	123	}
deb0e9b2	124	EXPORT_SYMBOL_GPL(cn_netlink_send);
7672d0b5 EP	125
	126	/*
	127	* Callback helper - queues work and setup destructor for given data.
	128	*/
	129	static int cn_call_callback(struct cn_msg msg, void (destruct_data)(void ), void data)
	130	{
	131	struct cn_callback_entry *__cbq;
	132	struct cn_dev *dev = &cdev;
acd042bb	133	int err = -ENODEV;
7672d0b5 EP	134
	135	spin_lock_bh(&dev->cbdev->queue_lock);
	136	list_for_each_entry(__cbq, &dev->cbdev->queue_list, callback_entry) {
acd042bb	137	if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
c4028958 DH	138	if (likely(!test_bit(WORK_STRUCT_PENDING,
c4028958 DH	139	&__cbq->work.work.management) &&
acd042bb EP	140	__cbq->data.ddata == NULL)) {
acd042bb EP	141	__cbq->data.callback_priv = msg;
7672d0b5	142
acd042bb EP	143	__cbq->data.ddata = data;
acd042bb EP	144	__cbq->data.destruct_data = destruct_data;
7672d0b5	145
c4028958 DH	146	if (queue_delayed_work(
	147	dev->cbdev->cn_queue,
	148	&__cbq->work, 0))
acd042bb	149	err = 0;
7672d0b5	150	} else {
acd042bb EP	151	struct cn_callback_data *d;
acd042bb EP	152
c4028958 DH	153	__cbq = kzalloc(sizeof(*__cbq), GFP_ATOMIC);
	154	if (__cbq) {
	155	d = &__cbq->data;
acd042bb EP	156	d->callback_priv = msg;
	157	d->callback = __cbq->data.callback;
	158	d->ddata = data;
	159	d->destruct_data = destruct_data;
c4028958	160	d->free = __cbq;
acd042bb	161
c4028958 DH	162	INIT_DELAYED_WORK(&__cbq->work,
c4028958 DH	163	&cn_queue_wrapper);
acd042bb	164
c4028958 DH	165	if (queue_delayed_work(
	166	dev->cbdev->cn_queue,
	167	&__cbq->work, 0))
acd042bb EP	168	err = 0;
acd042bb EP	169	else {
c4028958	170	kfree(__cbq);
acd042bb EP	171	err = -EINVAL;
	172	}
	173	} else
	174	err = -ENOMEM;
7672d0b5 EP	175	}
	176	break;
	177	}
	178	}
	179	spin_unlock_bh(&dev->cbdev->queue_lock);
	180
acd042bb	181	return err;
7672d0b5 EP	182	}
	183
	184	/*
	185	* Skb receive helper - checks skb and msg size and calls callback
	186	* helper.
	187	*/
	188	static int __cn_rx_skb(struct sk_buff skb, struct nlmsghdr nlh)
	189	{
	190	u32 pid, uid, seq, group;
	191	struct cn_msg *msg;
	192
	193	pid = NETLINK_CREDS(skb)->pid;
	194	uid = NETLINK_CREDS(skb)->uid;
	195	seq = nlh->nlmsg_seq;
	196	group = NETLINK_CB((skb)).dst_group;
	197	msg = NLMSG_DATA(nlh);
	198
	199	return cn_call_callback(msg, (void ()(void ))kfree_skb, skb);
	200	}
	201
	202	/*
	203	* Main netlink receiving function.
	204	*
	205	* It checks skb and netlink header sizes and calls the skb receive
	206	* helper with a shared skb.
	207	*/
	208	static void cn_rx_skb(struct sk_buff *__skb)
	209	{
	210	struct nlmsghdr *nlh;
	211	u32 len;
	212	int err;
	213	struct sk_buff *skb;
	214
	215	skb = skb_get(__skb);
	216
	217	if (skb->len >= NLMSG_SPACE(0)) {
	218	nlh = (struct nlmsghdr *)skb->data;
	219
	220	if (nlh->nlmsg_len < sizeof(struct cn_msg) \|\|
	221	skb->len < nlh->nlmsg_len \|\|
	222	nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
	223	kfree_skb(skb);
	224	goto out;
	225	}
	226
	227	len = NLMSG_ALIGN(nlh->nlmsg_len);
	228	if (len > skb->len)
	229	len = skb->len;
	230
	231	err = __cn_rx_skb(skb, nlh);
	232	if (err < 0)
	233	kfree_skb(skb);
	234	}
	235
	236	out:
	237	kfree_skb(__skb);
	238	}
	239
	240	/*
	241	* Netlink socket input callback - dequeues the skbs and calls the
	242	* main netlink receiving function.
	243	*/
	244	static void cn_input(struct sock *sk, int len)
	245	{
246	struct sk_buff *skb;
247
248	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL)
249	cn_rx_skb(skb);
250	}
251
252	/*
253	* Notification routing.
254	*
255	* Gets id and checks if there are notification request for it's idx
256	* and val. If there are such requests notify the listeners with the
257	* given notify event.
258	*
259	*/
260	static void cn_notify(struct cb_id *id, u32 notify_event)
261	{
262	struct cn_ctl_entry *ent;
263
8ed965d6	264	mutex_lock(&notify_lock);
7672d0b5 EP	265	list_for_each_entry(ent, &notify_list, notify_entry) {
	266	int i;
	267	struct cn_notify_req *req;
	268	struct cn_ctl_msg *ctl = ent->msg;
	269	int idx_found, val_found;
	270
	271	idx_found = val_found = 0;
	272
	273	req = (struct cn_notify_req *)ctl->data;
	274	for (i = 0; i < ctl->idx_notify_num; ++i, ++req) {
	275	if (id->idx >= req->first &&
	276	id->idx < req->first + req->range) {
	277	idx_found = 1;
	278	break;
	279	}
	280	}
	281
	282	for (i = 0; i < ctl->val_notify_num; ++i, ++req) {
	283	if (id->val >= req->first &&
	284	id->val < req->first + req->range) {
	285	val_found = 1;
	286	break;
	287	}
	288	}
	289
	290	if (idx_found && val_found) {
	291	struct cn_msg m = { .ack = notify_event, };
	292
	293	memcpy(&m.id, id, sizeof(m.id));
	294	cn_netlink_send(&m, ctl->group, GFP_KERNEL);
	295	}
	296	}
8ed965d6	297	mutex_unlock(&notify_lock);
7672d0b5 EP	298	}
	299
	300	/*
	301	* Callback add routing - adds callback with given ID and name.
	302	* If there is registered callback with the same ID it will not be added.
	303	*
	304	* May sleep.
	305	*/
	306	int cn_add_callback(struct cb_id id, char name, void (callback)(void ))
	307	{
	308	int err;
	309	struct cn_dev *dev = &cdev;
7672d0b5	310
d6cc7f1a EP	311	if (!cn_already_initialized)
	312	return -EAGAIN;
	313
acd042bb EP	314	err = cn_queue_add_callback(dev->cbdev, name, id, callback);
acd042bb EP	315	if (err)
7672d0b5	316	return err;
7672d0b5 EP	317
	318	cn_notify(id, 0);
	319
	320	return 0;
	321	}
deb0e9b2	322	EXPORT_SYMBOL_GPL(cn_add_callback);
7672d0b5 EP	323
	324	/*
	325	* Callback remove routing - removes callback
	326	* with given ID.
	327	* If there is no registered callback with given
	328	* ID nothing happens.
	329	*
	330	* May sleep while waiting for reference counter to become zero.
	331	*/
	332	void cn_del_callback(struct cb_id *id)
	333	{
	334	struct cn_dev *dev = &cdev;
	335
	336	cn_queue_del_callback(dev->cbdev, id);
	337	cn_notify(id, 1);
	338	}
deb0e9b2	339	EXPORT_SYMBOL_GPL(cn_del_callback);
7672d0b5 EP	340
	341	/*
	342	* Checks two connector's control messages to be the same.
	343	* Returns 1 if they are the same or if the first one is corrupted.
	344	*/
	345	static int cn_ctl_msg_equals(struct cn_ctl_msg m1, struct cn_ctl_msg m2)
	346	{
	347	int i;
	348	struct cn_notify_req req1, req2;
	349
	350	if (m1->idx_notify_num != m2->idx_notify_num)
	351	return 0;
	352
	353	if (m1->val_notify_num != m2->val_notify_num)
	354	return 0;
	355
	356	if (m1->len != m2->len)
	357	return 0;
	358
	359	if ((m1->idx_notify_num + m1->val_notify_num) * sizeof(*req1) !=
	360	m1->len)
	361	return 1;
	362
	363	req1 = (struct cn_notify_req *)m1->data;
	364	req2 = (struct cn_notify_req *)m2->data;
	365
	366	for (i = 0; i < m1->idx_notify_num; ++i) {
	367	if (req1->first != req2->first \|\| req1->range != req2->range)
	368	return 0;
	369	req1++;
	370	req2++;
	371	}
	372
	373	for (i = 0; i < m1->val_notify_num; ++i) {
	374	if (req1->first != req2->first \|\| req1->range != req2->range)
	375	return 0;
	376	req1++;
	377	req2++;
	378	}
	379
	380	return 1;
	381	}
	382
	383	/*
	384	* Main connector device's callback.
	385	*
	386	* Used for notification of a request's processing.
	387	*/
	388	static void cn_callback(void *data)
	389	{
	390	struct cn_msg *msg = data;
	391	struct cn_ctl_msg *ctl;
	392	struct cn_ctl_entry *ent;
	393	u32 size;
	394
	395	if (msg->len < sizeof(*ctl))
	396	return;
	397
	398	ctl = (struct cn_ctl_msg *)msg->data;
	399
	400	size = (sizeof(*ctl) + ((ctl->idx_notify_num +
	401	ctl->val_notify_num) *
	402	sizeof(struct cn_notify_req)));
	403
404	if (msg->len != size)
405	return;
406
407	if (ctl->len + sizeof(*ctl) != msg->len)
408	return;
409
410	/*
411	* Remove notification.
412	*/
413	if (ctl->group == 0) {
414	struct cn_ctl_entry *n;
415
8ed965d6	416	mutex_lock(&notify_lock);
7672d0b5 EP	417	list_for_each_entry_safe(ent, n, &notify_list, notify_entry) {
	418	if (cn_ctl_msg_equals(ent->msg, ctl)) {
	419	list_del(&ent->notify_entry);
	420	kfree(ent);
	421	}
	422	}
8ed965d6	423	mutex_unlock(&notify_lock);
7672d0b5 EP	424
	425	return;
	426	}
	427
	428	size += sizeof(*ent);
	429
	430	ent = kzalloc(size, GFP_KERNEL);
	431	if (!ent)
	432	return;
	433
	434	ent->msg = (struct cn_ctl_msg *)(ent + 1);
	435
	436	memcpy(ent->msg, ctl, size - sizeof(*ent));
	437
8ed965d6	438	mutex_lock(&notify_lock);
7672d0b5	439	list_add(&ent->notify_entry, &notify_list);
8ed965d6	440	mutex_unlock(&notify_lock);
7672d0b5 EP	441	}
7672d0b5 EP	442
d6cc7f1a	443	static int __devinit cn_init(void)
7672d0b5 EP	444	{
	445	struct cn_dev *dev = &cdev;
	446	int err;
	447
	448	dev->input = cn_input;
	449	dev->id.idx = cn_idx;
	450	dev->id.val = cn_val;
	451
	452	dev->nls = netlink_kernel_create(NETLINK_CONNECTOR,
	453	CN_NETLINK_USERS + 0xf,
	454	dev->input, THIS_MODULE);
	455	if (!dev->nls)
	456	return -EIO;
	457
	458	dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
	459	if (!dev->cbdev) {
	460	if (dev->nls->sk_socket)
	461	sock_release(dev->nls->sk_socket);
	462	return -EINVAL;
	463	}
d6cc7f1a EP	464
d6cc7f1a EP	465	cn_already_initialized = 1;
7672d0b5 EP	466
	467	err = cn_add_callback(&dev->id, "connector", &cn_callback);
	468	if (err) {
d6cc7f1a	469	cn_already_initialized = 0;
7672d0b5 EP	470	cn_queue_free_dev(dev->cbdev);
	471	if (dev->nls->sk_socket)
	472	sock_release(dev->nls->sk_socket);
	473	return -EINVAL;
	474	}
	475
7672d0b5 EP	476	return 0;
	477	}
	478
d6cc7f1a	479	static void __devexit cn_fini(void)
7672d0b5 EP	480	{
	481	struct cn_dev *dev = &cdev;
	482
	483	cn_already_initialized = 0;
	484
	485	cn_del_callback(&dev->id);
	486	cn_queue_free_dev(dev->cbdev);
	487	if (dev->nls->sk_socket)
	488	sock_release(dev->nls->sk_socket);
	489	}
	490
d6cc7f1a	491	subsys_initcall(cn_init);
7672d0b5	492	module_exit(cn_fini);