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

/*
 * 	connector.c
 *
 * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
 * 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 <linux/proc_fs.h>
#include <linux/spinlock.h>

#include <net/sock.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
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;

static int cn_already_initialized;

/*
 * 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;
				break;
			}
		}
		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 sk_buff *skb)
{
	struct cn_callback_entry *__cbq, *__new_cbq;
	struct cn_dev *dev = &cdev;
	struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb));
	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(!work_pending(&__cbq->work) &&
					__cbq->data.skb == NULL)) {
				__cbq->data.skb = skb;

				if (queue_cn_work(__cbq, &__cbq->work))
					err = 0;
				else
					err = -EINVAL;
			} else {
				struct cn_callback_data *d;

				err = -ENOMEM;
				__new_cbq = kzalloc(sizeof(struct cn_callback_entry), GFP_ATOMIC);
				if (__new_cbq) {
					d = &__new_cbq->data;
					d->skb = skb;
					d->callback = __cbq->data.callback;
					d->free = __new_cbq;

					__new_cbq->pdev = __cbq->pdev;

					INIT_WORK(&__new_cbq->work,
							&cn_queue_wrapper);

					if (queue_cn_work(__new_cbq,
						    &__new_cbq->work))
						err = 0;
					else {
						kfree(__new_cbq);
						err = -EINVAL;
					}
				}
			}
			break;
		}
	}
	spin_unlock_bh(&dev->cbdev->queue_lock);

	return err;
}

/*
 * Main netlink receiving function.
 *
 * It checks skb, netlink header and msg sizes, and calls callback helper.
 */
static void cn_rx_skb(struct sk_buff *__skb)
{
	struct nlmsghdr *nlh;
	int err;
	struct sk_buff *skb;

	skb = skb_get(__skb);

	if (skb->len >= NLMSG_SPACE(0)) {
		nlh = nlmsg_hdr(skb);

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

		err = cn_call_callback(skb);
		if (err < 0)
			kfree_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)(struct cn_msg *, struct netlink_skb_parms *))
{
	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(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
	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 cn_proc_show(struct seq_file *m, void *v)
{
	struct cn_queue_dev *dev = cdev.cbdev;
	struct cn_callback_entry *cbq;

	seq_printf(m, "Name            ID\n");

	spin_lock_bh(&dev->queue_lock);

	list_for_each_entry(cbq, &dev->queue_list, callback_entry) {
		seq_printf(m, "%-15s %u:%u\n",
			   cbq->id.name,
			   cbq->id.id.idx,
			   cbq->id.id.val);
	}

	spin_unlock_bh(&dev->queue_lock);

	return 0;
}

static int cn_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, cn_proc_show, NULL);
}

static const struct file_operations cn_file_ops = {
	.owner   = THIS_MODULE,
	.open    = cn_proc_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = single_release
};

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

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

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

	dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
	if (!dev->cbdev) {
		netlink_kernel_release(dev->nls);
		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);
		netlink_kernel_release(dev->nls);
		return -EINVAL;
	}

	proc_net_fops_create(&init_net, "connector", S_IRUGO, &cn_file_ops);

	return 0;
}

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

	cn_already_initialized = 0;

	proc_net_remove(&init_net, "connector");

	cn_del_callback(&dev->id);
	cn_queue_free_dev(dev->cbdev);
	netlink_kernel_release(dev->nls);
}

subsys_initcall(cn_init);
module_exit(cn_fini);
Commit	Line	Data
7672d0b5 EP	1	/*
7672d0b5 EP	2	* connector.c
1a5645bc	3	*
acb9c1b2	4	* 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
7672d0b5	5	* All rights reserved.
1a5645bc	6	*
7672d0b5 EP	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>
a0a61a60 LZ	30	#include <linux/proc_fs.h>
a0a61a60 LZ	31	#include <linux/spinlock.h>
7672d0b5 EP	32
	33	#include <net/sock.h>
	34
	35	MODULE_LICENSE("GPL");
acb9c1b2	36	MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
7672d0b5 EP	37	MODULE_DESCRIPTION("Generic userspace <-> kernelspace connector.");
	38
	39	static u32 cn_idx = CN_IDX_CONNECTOR;
	40	static u32 cn_val = CN_VAL_CONNECTOR;
	41
	42	module_param(cn_idx, uint, 0);
	43	module_param(cn_val, uint, 0);
	44	MODULE_PARM_DESC(cn_idx, "Connector's main device idx.");
	45	MODULE_PARM_DESC(cn_val, "Connector's main device val.");
	46
8ed965d6	47	static DEFINE_MUTEX(notify_lock);
7672d0b5 EP	48	static LIST_HEAD(notify_list);
	49
	50	static struct cn_dev cdev;
	51
78374676	52	static int cn_already_initialized;
7672d0b5 EP	53
	54	/*
	55	* msg->seq and msg->ack are used to determine message genealogy.
	56	* When someone sends message it puts there locally unique sequence
	57	* and random acknowledge numbers. Sequence number may be copied into
	58	* nlmsghdr->nlmsg_seq too.
	59	*
	60	* Sequence number is incremented with each message to be sent.
	61	*
	62	* If we expect reply to our message then the sequence number in
	63	* received message MUST be the same as in original message, and
	64	* acknowledge number MUST be the same + 1.
	65	*
	66	* If we receive a message and its sequence number is not equal to the
	67	* one we are expecting then it is a new message.
	68	*
	69	* If we receive a message and its sequence number is the same as one
	70	* we are expecting but it's acknowledgement number is not equal to
	71	* the acknowledgement number in the original message + 1, then it is
	72	* a new message.
	73	*
	74	*/
dd0fc66f	75	int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
7672d0b5 EP	76	{
	77	struct cn_callback_entry *__cbq;
	78	unsigned int size;
	79	struct sk_buff *skb;
	80	struct nlmsghdr *nlh;
	81	struct cn_msg *data;
	82	struct cn_dev *dev = &cdev;
	83	u32 group = 0;
	84	int found = 0;
	85
	86	if (!__group) {
	87	spin_lock_bh(&dev->cbdev->queue_lock);
	88	list_for_each_entry(__cbq, &dev->cbdev->queue_list,
	89	callback_entry) {
acd042bb	90	if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
7672d0b5 EP	91	found = 1;
7672d0b5 EP	92	group = __cbq->group;
fd00eecc	93	break;
7672d0b5 EP	94	}
	95	}
	96	spin_unlock_bh(&dev->cbdev->queue_lock);
	97
	98	if (!found)
	99	return -ENODEV;
	100	} else {
	101	group = __group;
	102	}
	103
b191ba0d EP	104	if (!netlink_has_listeners(dev->nls, group))
	105	return -ESRCH;
	106
7672d0b5 EP	107	size = NLMSG_SPACE(sizeof(*msg) + msg->len);
	108
	109	skb = alloc_skb(size, gfp_mask);
	110	if (!skb)
	111	return -ENOMEM;
	112
	113	nlh = NLMSG_PUT(skb, 0, msg->seq, NLMSG_DONE, size - sizeof(*nlh));
	114
	115	data = NLMSG_DATA(nlh);
	116
	117	memcpy(data, msg, sizeof(*data) + msg->len);
	118
	119	NETLINK_CB(skb).dst_group = group;
	120
b191ba0d	121	return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
7672d0b5 EP	122
	123	nlmsg_failure:
	124	kfree_skb(skb);
	125	return -EINVAL;
	126	}
deb0e9b2	127	EXPORT_SYMBOL_GPL(cn_netlink_send);
7672d0b5 EP	128
	129	/*
	130	* Callback helper - queues work and setup destructor for given data.
	131	*/
f1489cfb	132	static int cn_call_callback(struct sk_buff *skb)
7672d0b5	133	{
05e52dd7	134	struct cn_callback_entry __cbq, __new_cbq;
7672d0b5	135	struct cn_dev *dev = &cdev;
293500a2	136	struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb));
acd042bb	137	int err = -ENODEV;
7672d0b5 EP	138
	139	spin_lock_bh(&dev->cbdev->queue_lock);
	140	list_for_each_entry(__cbq, &dev->cbdev->queue_list, callback_entry) {
acd042bb	141	if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
a240d9f1	142	if (likely(!work_pending(&__cbq->work) &&
f1489cfb	143	__cbq->data.skb == NULL)) {
293500a2	144	__cbq->data.skb = skb;
7672d0b5	145
1a5645bc	146	if (queue_cn_work(__cbq, &__cbq->work))
acd042bb	147	err = 0;
134d99e3 LZ	148	else
134d99e3 LZ	149	err = -EINVAL;
7672d0b5	150	} else {
acd042bb	151	struct cn_callback_data *d;
1a5645bc	152
05e52dd7 PR	153	err = -ENOMEM;
	154	__new_cbq = kzalloc(sizeof(struct cn_callback_entry), GFP_ATOMIC);
	155	if (__new_cbq) {
	156	d = &__new_cbq->data;
293500a2	157	d->skb = skb;
acd042bb	158	d->callback = __cbq->data.callback;
05e52dd7	159	d->free = __new_cbq;
acd042bb	160
1a5645bc FW	161	__new_cbq->pdev = __cbq->pdev;
1a5645bc FW	162
05e52dd7	163	INIT_WORK(&__new_cbq->work,
a240d9f1	164	&cn_queue_wrapper);
05e52dd7	165
1a5645bc	166	if (queue_cn_work(__new_cbq,
05e52dd7	167	&__new_cbq->work))
acd042bb EP	168	err = 0;
acd042bb EP	169	else {
05e52dd7	170	kfree(__new_cbq);
acd042bb EP	171	err = -EINVAL;
acd042bb EP	172	}
05e52dd7	173	}
7672d0b5 EP	174	}
	175	break;
	176	}
	177	}
	178	spin_unlock_bh(&dev->cbdev->queue_lock);
	179
acd042bb	180	return err;
7672d0b5 EP	181	}
7672d0b5 EP	182
7672d0b5 EP	183	/*
	184	* Main netlink receiving function.
	185	*
00f5e06c	186	* It checks skb, netlink header and msg sizes, and calls callback helper.
7672d0b5 EP	187	*/
	188	static void cn_rx_skb(struct sk_buff *__skb)
	189	{
	190	struct nlmsghdr *nlh;
7672d0b5 EP	191	int err;
	192	struct sk_buff *skb;
	193
	194	skb = skb_get(__skb);
	195
	196	if (skb->len >= NLMSG_SPACE(0)) {
b529ccf2	197	nlh = nlmsg_hdr(skb);
7672d0b5 EP	198
	199	if (nlh->nlmsg_len < sizeof(struct cn_msg) \|\|
	200	skb->len < nlh->nlmsg_len \|\|
	201	nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
	202	kfree_skb(skb);
6cf92e98	203	return;
7672d0b5 EP	204	}
7672d0b5 EP	205
f1489cfb	206	err = cn_call_callback(skb);
7672d0b5 EP	207	if (err < 0)
	208	kfree_skb(skb);
	209	}
7672d0b5 EP	210	}
7672d0b5 EP	211
7672d0b5 EP	212	/*
	213	* Notification routing.
	214	*
	215	* Gets id and checks if there are notification request for it's idx
	216	* and val. If there are such requests notify the listeners with the
	217	* given notify event.
	218	*
	219	*/
	220	static void cn_notify(struct cb_id *id, u32 notify_event)
	221	{
	222	struct cn_ctl_entry *ent;
	223
8ed965d6	224	mutex_lock(&notify_lock);
7672d0b5 EP	225	list_for_each_entry(ent, &notify_list, notify_entry) {
	226	int i;
	227	struct cn_notify_req *req;
	228	struct cn_ctl_msg *ctl = ent->msg;
	229	int idx_found, val_found;
	230
	231	idx_found = val_found = 0;
	232
	233	req = (struct cn_notify_req *)ctl->data;
	234	for (i = 0; i < ctl->idx_notify_num; ++i, ++req) {
1a5645bc	235	if (id->idx >= req->first &&
7672d0b5 EP	236	id->idx < req->first + req->range) {
	237	idx_found = 1;
	238	break;
	239	}
	240	}
	241
	242	for (i = 0; i < ctl->val_notify_num; ++i, ++req) {
1a5645bc	243	if (id->val >= req->first &&
7672d0b5 EP	244	id->val < req->first + req->range) {
	245	val_found = 1;
	246	break;
	247	}
	248	}
	249
	250	if (idx_found && val_found) {
	251	struct cn_msg m = { .ack = notify_event, };
	252
	253	memcpy(&m.id, id, sizeof(m.id));
	254	cn_netlink_send(&m, ctl->group, GFP_KERNEL);
	255	}
	256	}
8ed965d6	257	mutex_unlock(&notify_lock);
7672d0b5 EP	258	}
	259
	260	/*
	261	* Callback add routing - adds callback with given ID and name.
	262	* If there is registered callback with the same ID it will not be added.
	263	*
	264	* May sleep.
	265	*/
0741241c	266	int cn_add_callback(struct cb_id id, char name,
7069331d	267	void (callback)(struct cn_msg , struct netlink_skb_parms *))
7672d0b5 EP	268	{
	269	int err;
	270	struct cn_dev *dev = &cdev;
7672d0b5	271
d6cc7f1a EP	272	if (!cn_already_initialized)
	273	return -EAGAIN;
	274
acd042bb EP	275	err = cn_queue_add_callback(dev->cbdev, name, id, callback);
acd042bb EP	276	if (err)
7672d0b5	277	return err;
7672d0b5 EP	278
	279	cn_notify(id, 0);
	280
	281	return 0;
	282	}
deb0e9b2	283	EXPORT_SYMBOL_GPL(cn_add_callback);
7672d0b5 EP	284
	285	/*
	286	* Callback remove routing - removes callback
	287	* with given ID.
	288	* If there is no registered callback with given
	289	* ID nothing happens.
	290	*
	291	* May sleep while waiting for reference counter to become zero.
	292	*/
	293	void cn_del_callback(struct cb_id *id)
	294	{
	295	struct cn_dev *dev = &cdev;
	296
	297	cn_queue_del_callback(dev->cbdev, id);
	298	cn_notify(id, 1);
	299	}
deb0e9b2	300	EXPORT_SYMBOL_GPL(cn_del_callback);
7672d0b5 EP	301
	302	/*
	303	* Checks two connector's control messages to be the same.
	304	* Returns 1 if they are the same or if the first one is corrupted.
	305	*/
	306	static int cn_ctl_msg_equals(struct cn_ctl_msg m1, struct cn_ctl_msg m2)
	307	{
	308	int i;
	309	struct cn_notify_req req1, req2;
	310
	311	if (m1->idx_notify_num != m2->idx_notify_num)
	312	return 0;
	313
	314	if (m1->val_notify_num != m2->val_notify_num)
	315	return 0;
	316
	317	if (m1->len != m2->len)
	318	return 0;
	319
	320	if ((m1->idx_notify_num + m1->val_notify_num) * sizeof(*req1) !=
	321	m1->len)
	322	return 1;
	323
	324	req1 = (struct cn_notify_req *)m1->data;
	325	req2 = (struct cn_notify_req *)m2->data;
	326
	327	for (i = 0; i < m1->idx_notify_num; ++i) {
	328	if (req1->first != req2->first \|\| req1->range != req2->range)
	329	return 0;
	330	req1++;
	331	req2++;
	332	}
	333
	334	for (i = 0; i < m1->val_notify_num; ++i) {
	335	if (req1->first != req2->first \|\| req1->range != req2->range)
	336	return 0;
	337	req1++;
	338	req2++;
	339	}
	340
	341	return 1;
	342	}
	343
	344	/*
	345	* Main connector device's callback.
	346	*
	347	* Used for notification of a request's processing.
	348	*/
7069331d	349	static void cn_callback(struct cn_msg msg, struct netlink_skb_parms nsp)
7672d0b5	350	{
7672d0b5 EP	351	struct cn_ctl_msg *ctl;
	352	struct cn_ctl_entry *ent;
	353	u32 size;
	354
	355	if (msg->len < sizeof(*ctl))
	356	return;
	357
	358	ctl = (struct cn_ctl_msg *)msg->data;
	359
	360	size = (sizeof(*ctl) + ((ctl->idx_notify_num +
	361	ctl->val_notify_num) *
	362	sizeof(struct cn_notify_req)));
	363
	364	if (msg->len != size)
	365	return;
	366
	367	if (ctl->len + sizeof(*ctl) != msg->len)
	368	return;
	369
	370	/*
	371	* Remove notification.
	372	*/
	373	if (ctl->group == 0) {
	374	struct cn_ctl_entry *n;
	375
8ed965d6	376	mutex_lock(&notify_lock);
7672d0b5 EP	377	list_for_each_entry_safe(ent, n, &notify_list, notify_entry) {
	378	if (cn_ctl_msg_equals(ent->msg, ctl)) {
	379	list_del(&ent->notify_entry);
	380	kfree(ent);
	381	}
	382	}
8ed965d6	383	mutex_unlock(&notify_lock);
7672d0b5 EP	384
	385	return;
	386	}
	387
	388	size += sizeof(*ent);
	389
	390	ent = kzalloc(size, GFP_KERNEL);
	391	if (!ent)
	392	return;
	393
	394	ent->msg = (struct cn_ctl_msg *)(ent + 1);
	395
	396	memcpy(ent->msg, ctl, size - sizeof(*ent));
	397
8ed965d6	398	mutex_lock(&notify_lock);
7672d0b5	399	list_add(&ent->notify_entry, &notify_list);
8ed965d6	400	mutex_unlock(&notify_lock);
7672d0b5 EP	401	}
7672d0b5 EP	402
a0a61a60 LZ	403	static int cn_proc_show(struct seq_file m, void v)
	404	{
	405	struct cn_queue_dev *dev = cdev.cbdev;
	406	struct cn_callback_entry *cbq;
	407
	408	seq_printf(m, "Name ID\n");
	409
	410	spin_lock_bh(&dev->queue_lock);
	411
	412	list_for_each_entry(cbq, &dev->queue_list, callback_entry) {
	413	seq_printf(m, "%-15s %u:%u\n",
	414	cbq->id.name,
	415	cbq->id.id.idx,
	416	cbq->id.id.val);
	417	}
	418
	419	spin_unlock_bh(&dev->queue_lock);
	420
	421	return 0;
	422	}
	423
	424	static int cn_proc_open(struct inode inode, struct file file)
	425	{
	426	return single_open(file, cn_proc_show, NULL);
	427	}
	428
	429	static const struct file_operations cn_file_ops = {
	430	.owner = THIS_MODULE,
	431	.open = cn_proc_open,
	432	.read = seq_read,
	433	.llseek = seq_lseek,
	434	.release = single_release
	435	};
	436
d6cc7f1a	437	static int __devinit cn_init(void)
7672d0b5 EP	438	{
	439	struct cn_dev *dev = &cdev;
	440	int err;
	441
cd40b7d3	442	dev->input = cn_rx_skb;
7672d0b5 EP	443	dev->id.idx = cn_idx;
	444	dev->id.val = cn_val;
	445
b4b51029	446	dev->nls = netlink_kernel_create(&init_net, NETLINK_CONNECTOR,
7672d0b5	447	CN_NETLINK_USERS + 0xf,
af65bdfc	448	dev->input, NULL, THIS_MODULE);
7672d0b5 EP	449	if (!dev->nls)
	450	return -EIO;
	451
	452	dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
	453	if (!dev->cbdev) {
b7c6ba6e	454	netlink_kernel_release(dev->nls);
7672d0b5 EP	455	return -EINVAL;
7672d0b5 EP	456	}
1a5645bc	457
d6cc7f1a	458	cn_already_initialized = 1;
7672d0b5 EP	459
	460	err = cn_add_callback(&dev->id, "connector", &cn_callback);
	461	if (err) {
d6cc7f1a	462	cn_already_initialized = 0;
7672d0b5	463	cn_queue_free_dev(dev->cbdev);
b7c6ba6e	464	netlink_kernel_release(dev->nls);
7672d0b5 EP	465	return -EINVAL;
	466	}
	467
a0a61a60 LZ	468	proc_net_fops_create(&init_net, "connector", S_IRUGO, &cn_file_ops);
a0a61a60 LZ	469
7672d0b5 EP	470	return 0;
	471	}
	472
d6cc7f1a	473	static void __devexit cn_fini(void)
7672d0b5 EP	474	{
	475	struct cn_dev *dev = &cdev;
	476
	477	cn_already_initialized = 0;
	478
a0a61a60 LZ	479	proc_net_remove(&init_net, "connector");
a0a61a60 LZ	480
7672d0b5 EP	481	cn_del_callback(&dev->id);
7672d0b5 EP	482	cn_queue_free_dev(dev->cbdev);
b7c6ba6e	483	netlink_kernel_release(dev->nls);
7672d0b5 EP	484	}
7672d0b5 EP	485
d6cc7f1a	486	subsys_initcall(cn_init);
7672d0b5	487	module_exit(cn_fini);