Release 4.14 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 <net/netlink.h>
#include <linux/moduleparam.h>
#include <linux/connector.h>
#include <linux/slab.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.");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_CONNECTOR);


static struct cn_dev cdev;


static int cn_already_initialized;

/*
 * Sends mult (multiple) cn_msg at a time.
 *
 * 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 a 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.
 *
 * If msg->len != len, then additional cn_msg messages are expected following
 * the first msg.
 *
 * The message is sent to, the portid if given, the group if given, both if
 * both, or if both are zero then the group is looked up and sent there.
 */


int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, 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 (portid || __group) {
		group = __group;
	} else {
		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;
	}

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

	size = sizeof(*msg) + len;

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

	nlh = nlmsg_put(skb, 0, msg->seq, NLMSG_DONE, size, 0);
	if (!nlh) {
		kfree_skb(skb);
		return -EMSGSIZE;
	}

	data = nlmsg_data(nlh);

	memcpy(data, msg, size);

	NETLINK_CB(skb).dst_group = group;

	if (group)
		return netlink_broadcast(dev->nls, skb, portid, group,
					 gfp_mask);
	return netlink_unicast(dev->nls, skb, portid,
			!gfpflags_allow_blocking(gfp_mask));
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
227
77.47%
3
27.27%
David Fries
39
13.31%
2
18.18%
Javier Martinez Canillas
20
6.83%
1
9.09%
Mel Gorman
3
1.02%
1
9.09%
Al Viro
1
0.34%
1
9.09%
Hong Zhi Guo
1
0.34%
1
9.09%
Mathias Krause
1
0.34%
1
9.09%
Li Zefan
1
0.34%
1
9.09%
Total
293
100.00%
11
100.00%


EXPORT_SYMBOL_GPL(cn_netlink_send_mult);

/* same as cn_netlink_send_mult except msg->len is used for len */


int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
	gfp_t gfp_mask)
{
	return cn_netlink_send_mult(msg, msg->len, portid, __group, gfp_mask);
}
Contributors
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CommitProp
David Fries
35
100.00%
1
100.00%
Total
35
100.00%
1
100.00%


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 nlmsghdr *nlh;
	struct cn_callback_entry *i, *cbq = NULL;
	struct cn_dev *dev = &cdev;
	struct cn_msg *msg = nlmsg_data(nlmsg_hdr(skb));
	struct netlink_skb_parms *nsp = &NETLINK_CB(skb);
	int err = -ENODEV;

	/* verify msg->len is within skb */
	nlh = nlmsg_hdr(skb);
	if (nlh->nlmsg_len < NLMSG_HDRLEN + sizeof(struct cn_msg) + msg->len)
		return -EINVAL;

	spin_lock_bh(&dev->cbdev->queue_lock);
	list_for_each_entry(i, &dev->cbdev->queue_list, callback_entry) {
		if (cn_cb_equal(&i->id.id, &msg->id)) {
			atomic_inc(&i->refcnt);
			cbq = i;
			break;
		}
	}
	spin_unlock_bh(&dev->cbdev->queue_lock);

	if (cbq != NULL) {
		cbq->callback(msg, nsp);
		kfree_skb(skb);
		cn_queue_release_callback(cbq);
		err = 0;
	}

	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
90
47.37%
2
20.00%
Patrick McHardy
43
22.63%
2
20.00%
David Fries
35
18.42%
1
10.00%
Philipp Reisner
16
8.42%
2
20.00%
Tejun Heo
4
2.11%
1
10.00%
David Howells
1
0.53%
1
10.00%
Hong Zhi Guo
1
0.53%
1
10.00%
Total
190
100.00%
10
100.00%

/*
 * 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 len, err;

	if (skb->len >= NLMSG_HDRLEN) {
		nlh = nlmsg_hdr(skb);
		len = nlmsg_len(nlh);

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

		err = cn_call_callback(skb_get(skb));
		if (err < 0)
			kfree_skb(skb);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
62
67.39%
1
12.50%
Mathias Krause
17
18.48%
1
12.50%
Florian Westphal
4
4.35%
1
12.50%
Arnaldo Carvalho de Melo
3
3.26%
1
12.50%
Li Zefan
3
3.26%
1
12.50%
Philipp Reisner
1
1.09%
1
12.50%
Michal Januszewski
1
1.09%
1
12.50%
Hong Zhi Guo
1
1.09%
1
12.50%
Total
92
100.00%
8
100.00%

/*
 * 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, const 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;

	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
68
90.67%
3
50.00%
Philipp Reisner
4
5.33%
1
16.67%
Mike Frysinger
2
2.67%
1
16.67%
Joe Perches
1
1.33%
1
16.67%
Total
75
100.00%
6
100.00%


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);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
27
100.00%
1
100.00%
Total
27
100.00%
1
100.00%


EXPORT_SYMBOL_GPL(cn_del_callback);



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Li Zefan
67
71.28%
1
33.33%
Evgeniy Polyakov
27
28.72%
2
66.67%
Total
94
100.00%
3
100.00%



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

Contributors
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Li Zefan
26
100.00%
1
100.00%
Total
26
100.00%
1
100.00%


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 struct cn_dev cdev = {
	.input   = cn_rx_skb,
};



static int cn_init(void)
{
	struct cn_dev *dev = &cdev;
	struct netlink_kernel_cfg cfg = {
		.groups	= CN_NETLINK_USERS + 0xf,
		.input	= dev->input,
        };

	dev->nls = netlink_kernel_create(&init_net, NETLINK_CONNECTOR, &cfg);
	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;

	proc_create("connector", S_IRUGO, init_net.proc_net, &cn_file_ops);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
79
68.10%
2
28.57%
Pablo Neira Ayuso
19
16.38%
1
14.29%
Li Zefan
9
7.76%
1
14.29%
Gao Feng
5
4.31%
1
14.29%
Eric W. Biedermann
3
2.59%
1
14.29%
Denis V. Lunev
1
0.86%
1
14.29%
Total
116
100.00%
7
100.00%



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

	cn_already_initialized = 0;

	remove_proc_entry("connector", init_net.proc_net);

	cn_queue_free_dev(dev->cbdev);
	netlink_kernel_release(dev->nls);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
33
76.74%
1
25.00%
Gao Feng
5
11.63%
1
25.00%
Li Zefan
4
9.30%
1
25.00%
Denis V. Lunev
1
2.33%
1
25.00%
Total
43
100.00%
4
100.00%


subsys_initcall(cn_init);

module_exit(cn_fini);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Evgeniy Polyakov
672
58.95%
6
14.63%
Li Zefan
151
13.25%
4
9.76%
David Fries
116
10.18%
3
7.32%
Patrick McHardy
43
3.77%
2
4.88%
Pablo Neira Ayuso
31
2.72%
1
2.44%
Philipp Reisner
21
1.84%
3
7.32%
Javier Martinez Canillas
20
1.75%
1
2.44%
Mathias Krause
18
1.58%
2
4.88%
Andrew Morton
15
1.32%
1
2.44%
Gao Feng
10
0.88%
2
4.88%
Tejun Heo
7
0.61%
2
4.88%
Stephen Hemminger
7
0.61%
1
2.44%
Hong Zhi Guo
4
0.35%
1
2.44%
Florian Westphal
4
0.35%
1
2.44%
Arnaldo Carvalho de Melo
3
0.26%
1
2.44%
Arjan van de Ven
3
0.26%
1
2.44%
Eric W. Biedermann
3
0.26%
1
2.44%
Mel Gorman
3
0.26%
1
2.44%
Mike Frysinger
2
0.18%
1
2.44%
Denis V. Lunev
2
0.18%
1
2.44%
Al Viro
1
0.09%
1
2.44%
Valentin Ilie
1
0.09%
1
2.44%
Joe Perches
1
0.09%
1
2.44%
Michal Januszewski
1
0.09%
1
2.44%
David Howells
1
0.09%
1
2.44%
Total
1140
100.00%
41
100.00%
Directory: drivers/connector

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