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
25 static struct sock *selnl;
26
selnl_msglen(int msgtype)27 static 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
selnl_add_payload(struct nlmsghdr * nlh,int len,int msgtype,void * data)46 static 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
selnl_notify(int msgtype,void * data)70 static 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);
91 out:
92 return;
93
94 out_kfree_skb:
95 kfree_skb(skb);
96 oom:
97 printk(KERN_ERR "SELinux: OOM in %s\n", __func__);
98 goto out;
99 }
100
selnl_notify_setenforce(int val)101 void selnl_notify_setenforce(int val)
102 {
103 selnl_notify(SELNL_MSG_SETENFORCE, &val);
104 }
105
selnl_notify_policyload(u32 seqno)106 void selnl_notify_policyload(u32 seqno)
107 {
108 selnl_notify(SELNL_MSG_POLICYLOAD, &seqno);
109 }
110
selnl_init(void)111 static 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