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82a37132 DB |
1 | /* |
2 | * Xtables module to match the process control group. | |
3 | * | |
4 | * Might be used to implement individual "per-application" firewall | |
5 | * policies in contrast to global policies based on control groups. | |
6 | * Matching is based upon processes tagged to net_cls' classid marker. | |
7 | * | |
8 | * (C) 2013 Daniel Borkmann <dborkman@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 | ||
b2606644 FW |
15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
16 | ||
82a37132 DB |
17 | #include <linux/skbuff.h> |
18 | #include <linux/module.h> | |
19 | #include <linux/netfilter/x_tables.h> | |
20 | #include <linux/netfilter/xt_cgroup.h> | |
21 | #include <net/sock.h> | |
22 | ||
23 | MODULE_LICENSE("GPL"); | |
24 | MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>"); | |
25 | MODULE_DESCRIPTION("Xtables: process control group matching"); | |
26 | MODULE_ALIAS("ipt_cgroup"); | |
27 | MODULE_ALIAS("ip6t_cgroup"); | |
28 | ||
4ec8ff0e | 29 | static int cgroup_mt_check_v0(const struct xt_mtchk_param *par) |
82a37132 | 30 | { |
4ec8ff0e | 31 | struct xt_cgroup_info_v0 *info = par->matchinfo; |
82a37132 DB |
32 | |
33 | if (info->invert & ~1) | |
34 | return -EINVAL; | |
35 | ||
caa8ad94 | 36 | return 0; |
82a37132 DB |
37 | } |
38 | ||
c38c4597 TH |
39 | static int cgroup_mt_check_v1(const struct xt_mtchk_param *par) |
40 | { | |
41 | struct xt_cgroup_info_v1 *info = par->matchinfo; | |
42 | struct cgroup *cgrp; | |
43 | ||
44 | if ((info->invert_path & ~1) || (info->invert_classid & ~1)) | |
45 | return -EINVAL; | |
46 | ||
47 | if (!info->has_path && !info->has_classid) { | |
48 | pr_info("xt_cgroup: no path or classid specified\n"); | |
49 | return -EINVAL; | |
50 | } | |
51 | ||
52 | if (info->has_path && info->has_classid) { | |
b2606644 | 53 | pr_info_ratelimited("path and classid specified\n"); |
c38c4597 TH |
54 | return -EINVAL; |
55 | } | |
56 | ||
ba7cd5d9 | 57 | info->priv = NULL; |
c38c4597 TH |
58 | if (info->has_path) { |
59 | cgrp = cgroup_get_from_path(info->path); | |
60 | if (IS_ERR(cgrp)) { | |
b2606644 FW |
61 | pr_info_ratelimited("invalid path, errno=%ld\n", |
62 | PTR_ERR(cgrp)); | |
c38c4597 TH |
63 | return -EINVAL; |
64 | } | |
65 | info->priv = cgrp; | |
66 | } | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
0d704967 PNA |
71 | static int cgroup_mt_check_v2(const struct xt_mtchk_param *par) |
72 | { | |
73 | struct xt_cgroup_info_v2 *info = par->matchinfo; | |
74 | struct cgroup *cgrp; | |
75 | ||
76 | if ((info->invert_path & ~1) || (info->invert_classid & ~1)) | |
77 | return -EINVAL; | |
78 | ||
79 | if (!info->has_path && !info->has_classid) { | |
80 | pr_info("xt_cgroup: no path or classid specified\n"); | |
81 | return -EINVAL; | |
82 | } | |
83 | ||
84 | if (info->has_path && info->has_classid) { | |
85 | pr_info_ratelimited("path and classid specified\n"); | |
86 | return -EINVAL; | |
87 | } | |
88 | ||
89 | info->priv = NULL; | |
90 | if (info->has_path) { | |
91 | cgrp = cgroup_get_from_path(info->path); | |
92 | if (IS_ERR(cgrp)) { | |
93 | pr_info_ratelimited("invalid path, errno=%ld\n", | |
94 | PTR_ERR(cgrp)); | |
95 | return -EINVAL; | |
96 | } | |
97 | info->priv = cgrp; | |
98 | } | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
82a37132 | 103 | static bool |
4ec8ff0e | 104 | cgroup_mt_v0(const struct sk_buff *skb, struct xt_action_param *par) |
82a37132 | 105 | { |
4ec8ff0e | 106 | const struct xt_cgroup_info_v0 *info = par->matchinfo; |
f5646501 | 107 | struct sock *sk = skb->sk; |
82a37132 | 108 | |
f5646501 | 109 | if (!sk || !sk_fullsock(sk) || !net_eq(xt_net(par), sock_net(sk))) |
82a37132 DB |
110 | return false; |
111 | ||
2a56a1fe TH |
112 | return (info->id == sock_cgroup_classid(&skb->sk->sk_cgrp_data)) ^ |
113 | info->invert; | |
82a37132 DB |
114 | } |
115 | ||
c38c4597 TH |
116 | static bool cgroup_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) |
117 | { | |
118 | const struct xt_cgroup_info_v1 *info = par->matchinfo; | |
119 | struct sock_cgroup_data *skcd = &skb->sk->sk_cgrp_data; | |
120 | struct cgroup *ancestor = info->priv; | |
f5646501 | 121 | struct sock *sk = skb->sk; |
c38c4597 | 122 | |
f5646501 | 123 | if (!sk || !sk_fullsock(sk) || !net_eq(xt_net(par), sock_net(sk))) |
c38c4597 TH |
124 | return false; |
125 | ||
126 | if (ancestor) | |
127 | return cgroup_is_descendant(sock_cgroup_ptr(skcd), ancestor) ^ | |
128 | info->invert_path; | |
129 | else | |
130 | return (info->classid == sock_cgroup_classid(skcd)) ^ | |
131 | info->invert_classid; | |
132 | } | |
133 | ||
0d704967 PNA |
134 | static bool cgroup_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
135 | { | |
136 | const struct xt_cgroup_info_v2 *info = par->matchinfo; | |
137 | struct sock_cgroup_data *skcd = &skb->sk->sk_cgrp_data; | |
138 | struct cgroup *ancestor = info->priv; | |
139 | struct sock *sk = skb->sk; | |
140 | ||
141 | if (!sk || !sk_fullsock(sk) || !net_eq(xt_net(par), sock_net(sk))) | |
142 | return false; | |
143 | ||
144 | if (ancestor) | |
145 | return cgroup_is_descendant(sock_cgroup_ptr(skcd), ancestor) ^ | |
146 | info->invert_path; | |
147 | else | |
148 | return (info->classid == sock_cgroup_classid(skcd)) ^ | |
149 | info->invert_classid; | |
150 | } | |
151 | ||
c38c4597 TH |
152 | static void cgroup_mt_destroy_v1(const struct xt_mtdtor_param *par) |
153 | { | |
154 | struct xt_cgroup_info_v1 *info = par->matchinfo; | |
155 | ||
156 | if (info->priv) | |
157 | cgroup_put(info->priv); | |
158 | } | |
159 | ||
0d704967 PNA |
160 | static void cgroup_mt_destroy_v2(const struct xt_mtdtor_param *par) |
161 | { | |
162 | struct xt_cgroup_info_v2 *info = par->matchinfo; | |
163 | ||
164 | if (info->priv) | |
165 | cgroup_put(info->priv); | |
166 | } | |
167 | ||
4ec8ff0e TH |
168 | static struct xt_match cgroup_mt_reg[] __read_mostly = { |
169 | { | |
170 | .name = "cgroup", | |
171 | .revision = 0, | |
172 | .family = NFPROTO_UNSPEC, | |
173 | .checkentry = cgroup_mt_check_v0, | |
174 | .match = cgroup_mt_v0, | |
175 | .matchsize = sizeof(struct xt_cgroup_info_v0), | |
176 | .me = THIS_MODULE, | |
177 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
178 | (1 << NF_INET_POST_ROUTING) | | |
179 | (1 << NF_INET_LOCAL_IN), | |
180 | }, | |
c38c4597 TH |
181 | { |
182 | .name = "cgroup", | |
183 | .revision = 1, | |
184 | .family = NFPROTO_UNSPEC, | |
185 | .checkentry = cgroup_mt_check_v1, | |
186 | .match = cgroup_mt_v1, | |
187 | .matchsize = sizeof(struct xt_cgroup_info_v1), | |
ec231890 | 188 | .usersize = offsetof(struct xt_cgroup_info_v1, priv), |
c38c4597 TH |
189 | .destroy = cgroup_mt_destroy_v1, |
190 | .me = THIS_MODULE, | |
191 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
192 | (1 << NF_INET_POST_ROUTING) | | |
193 | (1 << NF_INET_LOCAL_IN), | |
194 | }, | |
0d704967 PNA |
195 | { |
196 | .name = "cgroup", | |
197 | .revision = 2, | |
198 | .family = NFPROTO_UNSPEC, | |
199 | .checkentry = cgroup_mt_check_v2, | |
200 | .match = cgroup_mt_v2, | |
201 | .matchsize = sizeof(struct xt_cgroup_info_v2), | |
202 | .usersize = offsetof(struct xt_cgroup_info_v2, priv), | |
203 | .destroy = cgroup_mt_destroy_v2, | |
204 | .me = THIS_MODULE, | |
205 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
206 | (1 << NF_INET_POST_ROUTING) | | |
207 | (1 << NF_INET_LOCAL_IN), | |
208 | }, | |
82a37132 DB |
209 | }; |
210 | ||
211 | static int __init cgroup_mt_init(void) | |
212 | { | |
4ec8ff0e | 213 | return xt_register_matches(cgroup_mt_reg, ARRAY_SIZE(cgroup_mt_reg)); |
82a37132 DB |
214 | } |
215 | ||
216 | static void __exit cgroup_mt_exit(void) | |
217 | { | |
4ec8ff0e | 218 | xt_unregister_matches(cgroup_mt_reg, ARRAY_SIZE(cgroup_mt_reg)); |
82a37132 DB |
219 | } |
220 | ||
221 | module_init(cgroup_mt_init); | |
222 | module_exit(cgroup_mt_exit); |