1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Netlink event notifications for SELinux.
4 *
5 * Author: James Morris <jmorris@redhat.com>
6 *
7 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
8 */
9 #include <linux/init.h>
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/stddef.h>
13 #include <linux/kernel.h>
14 #include <linux/export.h>
15 #include <linux/skbuff.h>
16 #include <linux/selinux_netlink.h>
17 #include <net/net_namespace.h>
18 #include <net/netlink.h>
19
20 #include "initcalls.h"
21 #include "security.h"
22
23 static struct sock *selnl __ro_after_init;
24
selnl_msglen(int msgtype)25 static int selnl_msglen(int msgtype)
26 {
27 int ret = 0;
28
29 switch (msgtype) {
30 case SELNL_MSG_SETENFORCE:
31 ret = sizeof(struct selnl_msg_setenforce);
32 break;
33
34 case SELNL_MSG_POLICYLOAD:
35 ret = sizeof(struct selnl_msg_policyload);
36 break;
37
38 default:
39 BUG();
40 }
41 return ret;
42 }
43
selnl_add_payload(struct nlmsghdr * nlh,int len,int msgtype,void * data)44 static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data)
45 {
46 switch (msgtype) {
47 case SELNL_MSG_SETENFORCE: {
48 struct selnl_msg_setenforce *msg = nlmsg_data(nlh);
49
50 memset(msg, 0, len);
51 msg->val = *((int *)data);
52 break;
53 }
54
55 case SELNL_MSG_POLICYLOAD: {
56 struct selnl_msg_policyload *msg = nlmsg_data(nlh);
57
58 memset(msg, 0, len);
59 msg->seqno = *((u32 *)data);
60 break;
61 }
62
63 default:
64 BUG();
65 }
66 }
67
selnl_notify(int msgtype,void * data)68 static void selnl_notify(int msgtype, void *data)
69 {
70 int len;
71 sk_buff_data_t tmp;
72 struct sk_buff *skb;
73 struct nlmsghdr *nlh;
74
75 len = selnl_msglen(msgtype);
76
77 skb = nlmsg_new(len, GFP_USER);
78 if (!skb)
79 goto oom;
80
81 tmp = skb->tail;
82 nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0);
83 if (!nlh)
84 goto out_kfree_skb;
85 selnl_add_payload(nlh, len, msgtype, data);
86 nlh->nlmsg_len = skb->tail - tmp;
87 NETLINK_CB(skb).dst_group = SELNLGRP_AVC;
88 netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER);
89 out:
90 return;
91
92 out_kfree_skb:
93 kfree_skb(skb);
94 oom:
95 pr_err("SELinux: OOM in %s\n", __func__);
96 goto out;
97 }
98
selnl_notify_setenforce(int val)99 void selnl_notify_setenforce(int val)
100 {
101 selnl_notify(SELNL_MSG_SETENFORCE, &val);
102 }
103
selnl_notify_policyload(u32 seqno)104 void selnl_notify_policyload(u32 seqno)
105 {
106 selnl_notify(SELNL_MSG_POLICYLOAD, &seqno);
107 }
108
sel_netlink_init(void)109 int __init sel_netlink_init(void)
110 {
111 struct netlink_kernel_cfg cfg = {
112 .groups = SELNLGRP_MAX,
113 .flags = NL_CFG_F_NONROOT_RECV,
114 };
115
116 selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg);
117 if (selnl == NULL)
118 panic("SELinux: Cannot create netlink socket.");
119 return 0;
120 }
121