tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Module for modifying the secmark field of the skb, for use by
3 * security subsystems.
4 *
5 * Based on the nfmark match by:
6 * (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
7 *
8 * (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 */
15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/selinux.h>
18#include <linux/netfilter/x_tables.h>
19#include <linux/netfilter/xt_SECMARK.h>
20
21MODULE_LICENSE("GPL");
22MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
23MODULE_DESCRIPTION("ip[6]tables SECMARK modification module");
24MODULE_ALIAS("ipt_SECMARK");
25MODULE_ALIAS("ip6t_SECMARK");
26
27#define PFX "SECMARK: "
28
29static u8 mode;
30
31static unsigned int target(struct sk_buff **pskb, const struct net_device *in,
32 const struct net_device *out, unsigned int hooknum,
33 const struct xt_target *target,
34 const void *targinfo, void *userinfo)
35{
36 u32 secmark = 0;
37 const struct xt_secmark_target_info *info = targinfo;
38
39 BUG_ON(info->mode != mode);
40
41 switch (mode) {
42 case SECMARK_MODE_SEL:
43 secmark = info->u.sel.selsid;
44 break;
45
46 default:
47 BUG();
48 }
49
50 if ((*pskb)->secmark != secmark)
51 (*pskb)->secmark = secmark;
52
53 return XT_CONTINUE;
54}
55
56static int checkentry_selinux(struct xt_secmark_target_info *info)
57{
58 int err;
59 struct xt_secmark_target_selinux_info *sel = &info->u.sel;
60
61 err = selinux_string_to_sid(sel->selctx, &sel->selsid);
62 if (err) {
63 if (err == -EINVAL)
64 printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n",
65 sel->selctx);
66 return 0;
67 }
68
69 if (!sel->selsid) {
70 printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
71 sel->selctx);
72 return 0;
73 }
74
75 err = selinux_relabel_packet_permission(sel->selsid);
76 if (err) {
77 printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
78 return 0;
79 }
80
81 return 1;
82}
83
84static int checkentry(const char *tablename, const void *entry,
85 const struct xt_target *target, void *targinfo,
86 unsigned int targinfosize, unsigned int hook_mask)
87{
88 struct xt_secmark_target_info *info = targinfo;
89
90 if (mode && mode != info->mode) {
91 printk(KERN_INFO PFX "mode already set to %hu cannot mix with "
92 "rules for mode %hu\n", mode, info->mode);
93 return 0;
94 }
95
96 switch (info->mode) {
97 case SECMARK_MODE_SEL:
98 if (!checkentry_selinux(info))
99 return 0;
100 break;
101
102 default:
103 printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
104 return 0;
105 }
106
107 if (!mode)
108 mode = info->mode;
109 return 1;
110}
111
112static struct xt_target ipt_secmark_reg = {
113 .name = "SECMARK",
114 .target = target,
115 .targetsize = sizeof(struct xt_secmark_target_info),
116 .table = "mangle",
117 .checkentry = checkentry,
118 .me = THIS_MODULE,
119 .family = AF_INET,
120 .revision = 0,
121};
122
123static struct xt_target ip6t_secmark_reg = {
124 .name = "SECMARK",
125 .target = target,
126 .targetsize = sizeof(struct xt_secmark_target_info),
127 .table = "mangle",
128 .checkentry = checkentry,
129 .me = THIS_MODULE,
130 .family = AF_INET6,
131 .revision = 0,
132};
133
134static int __init xt_secmark_init(void)
135{
136 int err;
137
138 err = xt_register_target(&ipt_secmark_reg);
139 if (err)
140 return err;
141
142 err = xt_register_target(&ip6t_secmark_reg);
143 if (err)
144 xt_unregister_target(&ipt_secmark_reg);
145
146 return err;
147}
148
149static void __exit xt_secmark_fini(void)
150{
151 xt_unregister_target(&ip6t_secmark_reg);
152 xt_unregister_target(&ipt_secmark_reg);
153}
154
155module_init(xt_secmark_init);
156module_exit(xt_secmark_fini);