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