unix_diag: Basic module skeleton

#ifndef __UNIX_DIAG_H__

#define __UNIX_DIAG_H__

struct unix_diag_req {

	__u8	sdiag_family;

	__u8	sdiag_protocol;

	__u16	pad;

	__u32	udiag_states;

	__u32	udiag_ino;

	__u32	udiag_show;

	__u32	udiag_cookie[2];

};

struct unix_diag_msg {

	__u8	udiag_family;

	__u8	udiag_type;

	__u8	udiag_state;

	__u8	pad;

	__u32	udiag_ino;

	__u32	udiag_cookie[2];

};

#endif

#include <linux/types.h>

#include <linux/spinlock.h>

#include <linux/sock_diag.h>

#include <linux/unix_diag.h>

#include <linux/skbuff.h>

#include <net/netlink.h>

#include <net/af_unix.h>

#include <net/tcp_states.h>

#define UNIX_DIAG_PUT(skb, attrtype, attrlen) \

	RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))

static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)

{

	return 0;

}

static int unix_diag_get_exact(struct sk_buff *in_skb,

			       const struct nlmsghdr *nlh,

			       struct unix_diag_req *req)

{

	return -EAFNOSUPPORT;

}

static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)

{

	int hdrlen = sizeof(struct unix_diag_req);

	if (nlmsg_len(h) < hdrlen)

		return -EINVAL;

	if (h->nlmsg_flags & NLM_F_DUMP)

		return netlink_dump_start(sock_diag_nlsk, skb, h,

					  unix_diag_dump, NULL, 0);

	else

		return unix_diag_get_exact(skb, h, (struct unix_diag_req *)NLMSG_DATA(h));

}

static struct sock_diag_handler unix_diag_handler = {

	.family = AF_UNIX,

	.dump = unix_diag_handler_dump,

};

static int __init unix_diag_init(void)

{

	return sock_diag_register(&unix_diag_handler);

}

static void __exit unix_diag_exit(void)

{

	sock_diag_unregister(&unix_diag_handler);

}

module_init(unix_diag_init);

module_exit(unix_diag_exit);

MODULE_LICENSE("GPL");

MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);