1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Simplified MAC Kernel (smack) security module |
4 | * |
5 | * This file contains the Smack netfilter implementation |
6 | * |
7 | * Author: |
8 | * Casey Schaufler <casey@schaufler-ca.com> |
9 | * |
10 | * Copyright (C) 2014 Casey Schaufler <casey@schaufler-ca.com> |
11 | * Copyright (C) 2014 Intel Corporation. |
12 | */ |
13 | |
14 | #include <linux/netfilter_ipv4.h> |
15 | #include <linux/netfilter_ipv6.h> |
16 | #include <linux/netdevice.h> |
17 | #include <net/inet_sock.h> |
18 | #include <net/net_namespace.h> |
19 | #include "smack.h" |
20 | |
21 | static unsigned int smack_ip_output(void *priv, |
22 | struct sk_buff *skb, |
23 | const struct nf_hook_state *state) |
24 | { |
25 | struct sock *sk = skb_to_full_sk(skb); |
26 | struct socket_smack *ssp; |
27 | struct smack_known *skp; |
28 | |
29 | if (sk && sk->sk_security) { |
30 | ssp = sk->sk_security; |
31 | skp = ssp->smk_out; |
32 | skb->secmark = skp->smk_secid; |
33 | } |
34 | |
35 | return NF_ACCEPT; |
36 | } |
37 | |
38 | static const struct nf_hook_ops smack_nf_ops[] = { |
39 | { |
40 | .hook = smack_ip_output, |
41 | .pf = NFPROTO_IPV4, |
42 | .hooknum = NF_INET_LOCAL_OUT, |
43 | .priority = NF_IP_PRI_SELINUX_FIRST, |
44 | }, |
45 | #if IS_ENABLED(CONFIG_IPV6) |
46 | { |
47 | .hook = smack_ip_output, |
48 | .pf = NFPROTO_IPV6, |
49 | .hooknum = NF_INET_LOCAL_OUT, |
50 | .priority = NF_IP6_PRI_SELINUX_FIRST, |
51 | }, |
52 | #endif /* IPV6 */ |
53 | }; |
54 | |
55 | static int __net_init smack_nf_register(struct net *net) |
56 | { |
57 | return nf_register_net_hooks(net, reg: smack_nf_ops, |
58 | ARRAY_SIZE(smack_nf_ops)); |
59 | } |
60 | |
61 | static void __net_exit smack_nf_unregister(struct net *net) |
62 | { |
63 | nf_unregister_net_hooks(net, reg: smack_nf_ops, ARRAY_SIZE(smack_nf_ops)); |
64 | } |
65 | |
66 | static struct pernet_operations smack_net_ops = { |
67 | .init = smack_nf_register, |
68 | .exit = smack_nf_unregister, |
69 | }; |
70 | |
71 | static int __init smack_nf_ip_init(void) |
72 | { |
73 | if (smack_enabled == 0) |
74 | return 0; |
75 | |
76 | printk(KERN_DEBUG "Smack: Registering netfilter hooks\n" ); |
77 | return register_pernet_subsys(&smack_net_ops); |
78 | } |
79 | |
80 | __initcall(smack_nf_ip_init); |
81 | |