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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
82a37132 DB |
2 | /* |
3 | * Xtables module to match the process control group. | |
4 | * | |
5 | * Might be used to implement individual "per-application" firewall | |
6 | * policies in contrast to global policies based on control groups. | |
7 | * Matching is based upon processes tagged to net_cls' classid marker. | |
8 | * | |
9 | * (C) 2013 Daniel Borkmann <dborkman@redhat.com> | |
82a37132 DB |
10 | */ |
11 | ||
b2606644 FW |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
82a37132 DB |
14 | #include <linux/skbuff.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/netfilter/x_tables.h> | |
17 | #include <linux/netfilter/xt_cgroup.h> | |
18 | #include <net/sock.h> | |
19 | ||
20 | MODULE_LICENSE("GPL"); | |
21 | MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>"); | |
22 | MODULE_DESCRIPTION("Xtables: process control group matching"); | |
23 | MODULE_ALIAS("ipt_cgroup"); | |
24 | MODULE_ALIAS("ip6t_cgroup"); | |
25 | ||
4ec8ff0e | 26 | static int cgroup_mt_check_v0(const struct xt_mtchk_param *par) |
82a37132 | 27 | { |
4ec8ff0e | 28 | struct xt_cgroup_info_v0 *info = par->matchinfo; |
82a37132 DB |
29 | |
30 | if (info->invert & ~1) | |
31 | return -EINVAL; | |
32 | ||
caa8ad94 | 33 | return 0; |
82a37132 DB |
34 | } |
35 | ||
c38c4597 TH |
36 | static int cgroup_mt_check_v1(const struct xt_mtchk_param *par) |
37 | { | |
38 | struct xt_cgroup_info_v1 *info = par->matchinfo; | |
39 | struct cgroup *cgrp; | |
40 | ||
41 | if ((info->invert_path & ~1) || (info->invert_classid & ~1)) | |
42 | return -EINVAL; | |
43 | ||
44 | if (!info->has_path && !info->has_classid) { | |
45 | pr_info("xt_cgroup: no path or classid specified\n"); | |
46 | return -EINVAL; | |
47 | } | |
48 | ||
49 | if (info->has_path && info->has_classid) { | |
b2606644 | 50 | pr_info_ratelimited("path and classid specified\n"); |
c38c4597 TH |
51 | return -EINVAL; |
52 | } | |
53 | ||
ba7cd5d9 | 54 | info->priv = NULL; |
c38c4597 TH |
55 | if (info->has_path) { |
56 | cgrp = cgroup_get_from_path(info->path); | |
57 | if (IS_ERR(cgrp)) { | |
b2606644 FW |
58 | pr_info_ratelimited("invalid path, errno=%ld\n", |
59 | PTR_ERR(cgrp)); | |
c38c4597 TH |
60 | return -EINVAL; |
61 | } | |
62 | info->priv = cgrp; | |
63 | } | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
0d704967 PNA |
68 | static int cgroup_mt_check_v2(const struct xt_mtchk_param *par) |
69 | { | |
70 | struct xt_cgroup_info_v2 *info = par->matchinfo; | |
71 | struct cgroup *cgrp; | |
72 | ||
73 | if ((info->invert_path & ~1) || (info->invert_classid & ~1)) | |
74 | return -EINVAL; | |
75 | ||
76 | if (!info->has_path && !info->has_classid) { | |
77 | pr_info("xt_cgroup: no path or classid specified\n"); | |
78 | return -EINVAL; | |
79 | } | |
80 | ||
81 | if (info->has_path && info->has_classid) { | |
82 | pr_info_ratelimited("path and classid specified\n"); | |
83 | return -EINVAL; | |
84 | } | |
85 | ||
86 | info->priv = NULL; | |
87 | if (info->has_path) { | |
88 | cgrp = cgroup_get_from_path(info->path); | |
89 | if (IS_ERR(cgrp)) { | |
90 | pr_info_ratelimited("invalid path, errno=%ld\n", | |
91 | PTR_ERR(cgrp)); | |
92 | return -EINVAL; | |
93 | } | |
94 | info->priv = cgrp; | |
95 | } | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
82a37132 | 100 | static bool |
4ec8ff0e | 101 | cgroup_mt_v0(const struct sk_buff *skb, struct xt_action_param *par) |
82a37132 | 102 | { |
4ec8ff0e | 103 | const struct xt_cgroup_info_v0 *info = par->matchinfo; |
f5646501 | 104 | struct sock *sk = skb->sk; |
82a37132 | 105 | |
f5646501 | 106 | if (!sk || !sk_fullsock(sk) || !net_eq(xt_net(par), sock_net(sk))) |
82a37132 DB |
107 | return false; |
108 | ||
2a56a1fe TH |
109 | return (info->id == sock_cgroup_classid(&skb->sk->sk_cgrp_data)) ^ |
110 | info->invert; | |
82a37132 DB |
111 | } |
112 | ||
c38c4597 TH |
113 | static bool cgroup_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) |
114 | { | |
115 | const struct xt_cgroup_info_v1 *info = par->matchinfo; | |
116 | struct sock_cgroup_data *skcd = &skb->sk->sk_cgrp_data; | |
117 | struct cgroup *ancestor = info->priv; | |
f5646501 | 118 | struct sock *sk = skb->sk; |
c38c4597 | 119 | |
f5646501 | 120 | if (!sk || !sk_fullsock(sk) || !net_eq(xt_net(par), sock_net(sk))) |
c38c4597 TH |
121 | return false; |
122 | ||
123 | if (ancestor) | |
124 | return cgroup_is_descendant(sock_cgroup_ptr(skcd), ancestor) ^ | |
125 | info->invert_path; | |
126 | else | |
127 | return (info->classid == sock_cgroup_classid(skcd)) ^ | |
128 | info->invert_classid; | |
129 | } | |
130 | ||
0d704967 PNA |
131 | static bool cgroup_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
132 | { | |
133 | const struct xt_cgroup_info_v2 *info = par->matchinfo; | |
134 | struct sock_cgroup_data *skcd = &skb->sk->sk_cgrp_data; | |
135 | struct cgroup *ancestor = info->priv; | |
136 | struct sock *sk = skb->sk; | |
137 | ||
138 | if (!sk || !sk_fullsock(sk) || !net_eq(xt_net(par), sock_net(sk))) | |
139 | return false; | |
140 | ||
141 | if (ancestor) | |
142 | return cgroup_is_descendant(sock_cgroup_ptr(skcd), ancestor) ^ | |
143 | info->invert_path; | |
144 | else | |
145 | return (info->classid == sock_cgroup_classid(skcd)) ^ | |
146 | info->invert_classid; | |
147 | } | |
148 | ||
c38c4597 TH |
149 | static void cgroup_mt_destroy_v1(const struct xt_mtdtor_param *par) |
150 | { | |
151 | struct xt_cgroup_info_v1 *info = par->matchinfo; | |
152 | ||
153 | if (info->priv) | |
154 | cgroup_put(info->priv); | |
155 | } | |
156 | ||
0d704967 PNA |
157 | static void cgroup_mt_destroy_v2(const struct xt_mtdtor_param *par) |
158 | { | |
159 | struct xt_cgroup_info_v2 *info = par->matchinfo; | |
160 | ||
161 | if (info->priv) | |
162 | cgroup_put(info->priv); | |
163 | } | |
164 | ||
4ec8ff0e TH |
165 | static struct xt_match cgroup_mt_reg[] __read_mostly = { |
166 | { | |
167 | .name = "cgroup", | |
168 | .revision = 0, | |
169 | .family = NFPROTO_UNSPEC, | |
170 | .checkentry = cgroup_mt_check_v0, | |
171 | .match = cgroup_mt_v0, | |
172 | .matchsize = sizeof(struct xt_cgroup_info_v0), | |
173 | .me = THIS_MODULE, | |
174 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
175 | (1 << NF_INET_POST_ROUTING) | | |
176 | (1 << NF_INET_LOCAL_IN), | |
177 | }, | |
c38c4597 TH |
178 | { |
179 | .name = "cgroup", | |
180 | .revision = 1, | |
181 | .family = NFPROTO_UNSPEC, | |
182 | .checkentry = cgroup_mt_check_v1, | |
183 | .match = cgroup_mt_v1, | |
184 | .matchsize = sizeof(struct xt_cgroup_info_v1), | |
ec231890 | 185 | .usersize = offsetof(struct xt_cgroup_info_v1, priv), |
c38c4597 TH |
186 | .destroy = cgroup_mt_destroy_v1, |
187 | .me = THIS_MODULE, | |
188 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
189 | (1 << NF_INET_POST_ROUTING) | | |
190 | (1 << NF_INET_LOCAL_IN), | |
191 | }, | |
0d704967 PNA |
192 | { |
193 | .name = "cgroup", | |
194 | .revision = 2, | |
195 | .family = NFPROTO_UNSPEC, | |
196 | .checkentry = cgroup_mt_check_v2, | |
197 | .match = cgroup_mt_v2, | |
198 | .matchsize = sizeof(struct xt_cgroup_info_v2), | |
199 | .usersize = offsetof(struct xt_cgroup_info_v2, priv), | |
200 | .destroy = cgroup_mt_destroy_v2, | |
201 | .me = THIS_MODULE, | |
202 | .hooks = (1 << NF_INET_LOCAL_OUT) | | |
203 | (1 << NF_INET_POST_ROUTING) | | |
204 | (1 << NF_INET_LOCAL_IN), | |
205 | }, | |
82a37132 DB |
206 | }; |
207 | ||
208 | static int __init cgroup_mt_init(void) | |
209 | { | |
4ec8ff0e | 210 | return xt_register_matches(cgroup_mt_reg, ARRAY_SIZE(cgroup_mt_reg)); |
82a37132 DB |
211 | } |
212 | ||
213 | static void __exit cgroup_mt_exit(void) | |
214 | { | |
4ec8ff0e | 215 | xt_unregister_matches(cgroup_mt_reg, ARRAY_SIZE(cgroup_mt_reg)); |
82a37132 DB |
216 | } |
217 | ||
218 | module_init(cgroup_mt_init); | |
219 | module_exit(cgroup_mt_exit); |