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0265ab44 JE |
1 | /* |
2 | * Kernel module to match various things tied to sockets associated with | |
3 | * locally generated outgoing packets. | |
4 | * | |
5 | * (C) 2000 Marc Boucher <marc@mbsi.ca> | |
6 | * | |
edc26f7a JE |
7 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
8 | * <jengelh@computergmbh.de> | |
0265ab44 JE |
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 | #include <linux/module.h> | |
15 | #include <linux/skbuff.h> | |
16 | #include <linux/file.h> | |
17 | #include <net/sock.h> | |
18 | #include <linux/netfilter/x_tables.h> | |
19 | #include <linux/netfilter/xt_owner.h> | |
20 | #include <linux/netfilter_ipv4/ipt_owner.h> | |
21 | #include <linux/netfilter_ipv6/ip6t_owner.h> | |
22 | ||
23 | static bool | |
f7108a20 | 24 | owner_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par) |
0265ab44 | 25 | { |
f7108a20 | 26 | const struct ipt_owner_info *info = par->matchinfo; |
0265ab44 JE |
27 | const struct file *filp; |
28 | ||
29 | if (skb->sk == NULL || skb->sk->sk_socket == NULL) | |
30 | return false; | |
31 | ||
32 | filp = skb->sk->sk_socket->file; | |
33 | if (filp == NULL) | |
34 | return false; | |
35 | ||
36 | if (info->match & IPT_OWNER_UID) | |
d76b0d9b | 37 | if ((filp->f_cred->fsuid != info->uid) ^ |
0265ab44 JE |
38 | !!(info->invert & IPT_OWNER_UID)) |
39 | return false; | |
40 | ||
41 | if (info->match & IPT_OWNER_GID) | |
d76b0d9b | 42 | if ((filp->f_cred->fsgid != info->gid) ^ |
0265ab44 JE |
43 | !!(info->invert & IPT_OWNER_GID)) |
44 | return false; | |
45 | ||
46 | return true; | |
47 | } | |
48 | ||
49 | static bool | |
f7108a20 | 50 | owner_mt6_v0(const struct sk_buff *skb, const struct xt_match_param *par) |
0265ab44 | 51 | { |
f7108a20 | 52 | const struct ip6t_owner_info *info = par->matchinfo; |
0265ab44 JE |
53 | const struct file *filp; |
54 | ||
55 | if (skb->sk == NULL || skb->sk->sk_socket == NULL) | |
56 | return false; | |
57 | ||
58 | filp = skb->sk->sk_socket->file; | |
59 | if (filp == NULL) | |
60 | return false; | |
61 | ||
62 | if (info->match & IP6T_OWNER_UID) | |
d76b0d9b | 63 | if ((filp->f_cred->fsuid != info->uid) ^ |
0265ab44 JE |
64 | !!(info->invert & IP6T_OWNER_UID)) |
65 | return false; | |
66 | ||
67 | if (info->match & IP6T_OWNER_GID) | |
d76b0d9b | 68 | if ((filp->f_cred->fsgid != info->gid) ^ |
0265ab44 JE |
69 | !!(info->invert & IP6T_OWNER_GID)) |
70 | return false; | |
71 | ||
72 | return true; | |
73 | } | |
74 | ||
75 | static bool | |
f7108a20 | 76 | owner_mt(const struct sk_buff *skb, const struct xt_match_param *par) |
0265ab44 | 77 | { |
f7108a20 | 78 | const struct xt_owner_match_info *info = par->matchinfo; |
0265ab44 JE |
79 | const struct file *filp; |
80 | ||
81 | if (skb->sk == NULL || skb->sk->sk_socket == NULL) | |
82 | return (info->match ^ info->invert) == 0; | |
83 | else if (info->match & info->invert & XT_OWNER_SOCKET) | |
84 | /* | |
85 | * Socket exists but user wanted ! --socket-exists. | |
86 | * (Single ampersands intended.) | |
87 | */ | |
88 | return false; | |
89 | ||
90 | filp = skb->sk->sk_socket->file; | |
91 | if (filp == NULL) | |
92 | return ((info->match ^ info->invert) & | |
93 | (XT_OWNER_UID | XT_OWNER_GID)) == 0; | |
94 | ||
95 | if (info->match & XT_OWNER_UID) | |
d76b0d9b DH |
96 | if ((filp->f_cred->fsuid >= info->uid_min && |
97 | filp->f_cred->fsuid <= info->uid_max) ^ | |
edc26f7a | 98 | !(info->invert & XT_OWNER_UID)) |
0265ab44 JE |
99 | return false; |
100 | ||
101 | if (info->match & XT_OWNER_GID) | |
d76b0d9b DH |
102 | if ((filp->f_cred->fsgid >= info->gid_min && |
103 | filp->f_cred->fsgid <= info->gid_max) ^ | |
edc26f7a | 104 | !(info->invert & XT_OWNER_GID)) |
0265ab44 JE |
105 | return false; |
106 | ||
107 | return true; | |
108 | } | |
109 | ||
9b4fce7a | 110 | static bool owner_mt_check_v0(const struct xt_mtchk_param *par) |
0265ab44 | 111 | { |
9b4fce7a | 112 | const struct ipt_owner_info *info = par->matchinfo; |
0265ab44 JE |
113 | |
114 | if (info->match & (IPT_OWNER_PID | IPT_OWNER_SID | IPT_OWNER_COMM)) { | |
115 | printk(KERN_WARNING KBUILD_MODNAME | |
116 | ": PID, SID and command matching is not " | |
117 | "supported anymore\n"); | |
118 | return false; | |
119 | } | |
120 | ||
121 | return true; | |
122 | } | |
123 | ||
9b4fce7a | 124 | static bool owner_mt6_check_v0(const struct xt_mtchk_param *par) |
0265ab44 | 125 | { |
9b4fce7a | 126 | const struct ip6t_owner_info *info = par->matchinfo; |
0265ab44 JE |
127 | |
128 | if (info->match & (IP6T_OWNER_PID | IP6T_OWNER_SID)) { | |
129 | printk(KERN_WARNING KBUILD_MODNAME | |
130 | ": PID and SID matching is not supported anymore\n"); | |
131 | return false; | |
132 | } | |
133 | ||
134 | return true; | |
135 | } | |
136 | ||
137 | static struct xt_match owner_mt_reg[] __read_mostly = { | |
138 | { | |
139 | .name = "owner", | |
140 | .revision = 0, | |
ee999d8b | 141 | .family = NFPROTO_IPV4, |
0265ab44 JE |
142 | .match = owner_mt_v0, |
143 | .matchsize = sizeof(struct ipt_owner_info), | |
144 | .checkentry = owner_mt_check_v0, | |
145 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
146 | (1 << NF_INET_POST_ROUTING), | |
147 | .me = THIS_MODULE, | |
148 | }, | |
149 | { | |
150 | .name = "owner", | |
151 | .revision = 0, | |
ee999d8b | 152 | .family = NFPROTO_IPV6, |
0265ab44 JE |
153 | .match = owner_mt6_v0, |
154 | .matchsize = sizeof(struct ip6t_owner_info), | |
155 | .checkentry = owner_mt6_check_v0, | |
156 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
157 | (1 << NF_INET_POST_ROUTING), | |
158 | .me = THIS_MODULE, | |
159 | }, | |
160 | { | |
161 | .name = "owner", | |
162 | .revision = 1, | |
ab4f21e6 | 163 | .family = NFPROTO_UNSPEC, |
0265ab44 JE |
164 | .match = owner_mt, |
165 | .matchsize = sizeof(struct xt_owner_match_info), | |
166 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
167 | (1 << NF_INET_POST_ROUTING), | |
168 | .me = THIS_MODULE, | |
169 | }, | |
170 | }; | |
171 | ||
172 | static int __init owner_mt_init(void) | |
173 | { | |
174 | return xt_register_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg)); | |
175 | } | |
176 | ||
177 | static void __exit owner_mt_exit(void) | |
178 | { | |
179 | xt_unregister_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg)); | |
180 | } | |
181 | ||
182 | module_init(owner_mt_init); | |
183 | module_exit(owner_mt_exit); | |
184 | MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>"); | |
2ae15b64 | 185 | MODULE_DESCRIPTION("Xtables: socket owner matching"); |
0265ab44 JE |
186 | MODULE_LICENSE("GPL"); |
187 | MODULE_ALIAS("ipt_owner"); | |
188 | MODULE_ALIAS("ip6t_owner"); |