![Florian Westphal](/assets/img/avatar_default.png)
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
149 lines
3.7 KiB
C
149 lines
3.7 KiB
C
/*
|
|
* 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>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#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 bool
|
|
cgroup_mt_v0(const struct sk_buff *skb, struct xt_action_param *par)
|
|
{
|
|
const struct xt_cgroup_info_v0 *info = par->matchinfo;
|
|
|
|
if (skb->sk == NULL || !sk_fullsock(skb->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;
|
|
|
|
if (!skb->sk || !sk_fullsock(skb->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 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),
|
|
},
|
|
};
|
|
|
|
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);
|