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 "security.h"
21
22static struct sock *selnl __ro_after_init;
23
24static int selnl_msglen(int msgtype)
25{
26 int ret = 0;
27
28 switch (msgtype) {
29 case SELNL_MSG_SETENFORCE:
30 ret = sizeof(struct selnl_msg_setenforce);
31 break;
32
33 case SELNL_MSG_POLICYLOAD:
34 ret = sizeof(struct selnl_msg_policyload);
35 break;
36
37 default:
38 BUG();
39 }
40 return ret;
41}
42
43static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data)
44{
45 switch (msgtype) {
46 case SELNL_MSG_SETENFORCE: {
47 struct selnl_msg_setenforce *msg = nlmsg_data(nlh);
48
49 memset(s: msg, c: 0, n: len);
50 msg->val = *((int *)data);
51 break;
52 }
53
54 case SELNL_MSG_POLICYLOAD: {
55 struct selnl_msg_policyload *msg = nlmsg_data(nlh);
56
57 memset(s: msg, c: 0, n: len);
58 msg->seqno = *((u32 *)data);
59 break;
60 }
61
62 default:
63 BUG();
64 }
65}
66
67static void selnl_notify(int msgtype, void *data)
68{
69 int len;
70 sk_buff_data_t tmp;
71 struct sk_buff *skb;
72 struct nlmsghdr *nlh;
73
74 len = selnl_msglen(msgtype);
75
76 skb = nlmsg_new(payload: len, GFP_USER);
77 if (!skb)
78 goto oom;
79
80 tmp = skb->tail;
81 nlh = nlmsg_put(skb, portid: 0, seq: 0, type: msgtype, payload: len, flags: 0);
82 if (!nlh)
83 goto out_kfree_skb;
84 selnl_add_payload(nlh, len, msgtype, data);
85 nlh->nlmsg_len = skb->tail - tmp;
86 NETLINK_CB(skb).dst_group = SELNLGRP_AVC;
87 netlink_broadcast(ssk: selnl, skb, portid: 0, SELNLGRP_AVC, GFP_USER);
88out:
89 return;
90
91out_kfree_skb:
92 kfree_skb(skb);
93oom:
94 pr_err("SELinux: OOM in %s\n", __func__);
95 goto out;
96}
97
98void selnl_notify_setenforce(int val)
99{
100 selnl_notify(msgtype: SELNL_MSG_SETENFORCE, data: &val);
101}
102
103void selnl_notify_policyload(u32 seqno)
104{
105 selnl_notify(msgtype: SELNL_MSG_POLICYLOAD, data: &seqno);
106}
107
108static int __init selnl_init(void)
109{
110 struct netlink_kernel_cfg cfg = {
111 .groups = SELNLGRP_MAX,
112 .flags = NL_CFG_F_NONROOT_RECV,
113 };
114
115 selnl = netlink_kernel_create(net: &init_net, NETLINK_SELINUX, cfg: &cfg);
116 if (selnl == NULL)
117 panic(fmt: "SELinux: Cannot create netlink socket.");
118 return 0;
119}
120
121__initcall(selnl_init);
122