1/*
2 * Netlink event notifications for SELinux.
3 *
4 * Author: James Morris <jmorris@redhat.com>
5 *
6 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2,
10 * as published by the Free Software Foundation.
11 */
12#include <linux/init.h>
13#include <linux/types.h>
14#include <linux/slab.h>
15#include <linux/stddef.h>
16#include <linux/kernel.h>
17#include <linux/export.h>
18#include <linux/skbuff.h>
19#include <linux/selinux_netlink.h>
20#include <net/net_namespace.h>
21#include <net/netlink.h>
22
23#include "security.h"
24
25static struct sock *selnl;
26
27static int selnl_msglen(int msgtype)
28{
29	int ret = 0;
30
31	switch (msgtype) {
32	case SELNL_MSG_SETENFORCE:
33		ret = sizeof(struct selnl_msg_setenforce);
34		break;
35
36	case SELNL_MSG_POLICYLOAD:
37		ret = sizeof(struct selnl_msg_policyload);
38		break;
39
40	default:
41		BUG();
42	}
43	return ret;
44}
45
46static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data)
47{
48	switch (msgtype) {
49	case SELNL_MSG_SETENFORCE: {
50		struct selnl_msg_setenforce *msg = nlmsg_data(nlh);
51
52		memset(msg, 0, len);
53		msg->val = *((int *)data);
54		break;
55	}
56
57	case SELNL_MSG_POLICYLOAD: {
58		struct selnl_msg_policyload *msg = nlmsg_data(nlh);
59
60		memset(msg, 0, len);
61		msg->seqno = *((u32 *)data);
62		break;
63	}
64
65	default:
66		BUG();
67	}
68}
69
70static void selnl_notify(int msgtype, void *data)
71{
72	int len;
73	sk_buff_data_t tmp;
74	struct sk_buff *skb;
75	struct nlmsghdr *nlh;
76
77	len = selnl_msglen(msgtype);
78
79	skb = nlmsg_new(len, GFP_USER);
80	if (!skb)
81		goto oom;
82
83	tmp = skb->tail;
84	nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0);
85	if (!nlh)
86		goto out_kfree_skb;
87	selnl_add_payload(nlh, len, msgtype, data);
88	nlh->nlmsg_len = skb->tail - tmp;
89	NETLINK_CB(skb).dst_group = SELNLGRP_AVC;
90	netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER);
91out:
92	return;
93
94out_kfree_skb:
95	kfree_skb(skb);
96oom:
97	printk(KERN_ERR "SELinux:  OOM in %s\n", __func__);
98	goto out;
99}
100
101void selnl_notify_setenforce(int val)
102{
103	selnl_notify(SELNL_MSG_SETENFORCE, &val);
104}
105
106void selnl_notify_policyload(u32 seqno)
107{
108	selnl_notify(SELNL_MSG_POLICYLOAD, &seqno);
109}
110
111static int __init selnl_init(void)
112{
113	struct netlink_kernel_cfg cfg = {
114		.groups	= SELNLGRP_MAX,
115		.flags	= NL_CFG_F_NONROOT_RECV,
116	};
117
118	selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg);
119	if (selnl == NULL)
120		panic("SELinux:  Cannot create netlink socket.");
121	return 0;
122}
123
124__initcall(selnl_init);
125