[mirror_ubuntu-bionic-kernel.git] / net / netfilter / xt_cgroup.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.
 */

#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("xt_cgroup: both 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("xt_cgroup: 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);
Commit	Line	Data
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
	15	#include <linux/skbuff.h>
	16	#include <linux/module.h>
	17	#include <linux/netfilter/x_tables.h>
	18	#include <linux/netfilter/xt_cgroup.h>
	19	#include <net/sock.h>
	20
	21	MODULE_LICENSE("GPL");
	22	MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
	23	MODULE_DESCRIPTION("Xtables: process control group matching");
	24	MODULE_ALIAS("ipt_cgroup");
	25	MODULE_ALIAS("ip6t_cgroup");
	26
4ec8ff0e	27	static int cgroup_mt_check_v0(const struct xt_mtchk_param *par)
82a37132	28	{
4ec8ff0e	29	struct xt_cgroup_info_v0 *info = par->matchinfo;
82a37132 DB	30
	31	if (info->invert & ~1)
	32	return -EINVAL;
	33
caa8ad94	34	return 0;
82a37132 DB	35	}
82a37132 DB	36
c38c4597 TH	37	static int cgroup_mt_check_v1(const struct xt_mtchk_param *par)
	38	{
	39	struct xt_cgroup_info_v1 *info = par->matchinfo;
	40	struct cgroup *cgrp;
	41
	42	if ((info->invert_path & ~1) \|\| (info->invert_classid & ~1))
	43	return -EINVAL;
	44
	45	if (!info->has_path && !info->has_classid) {
	46	pr_info("xt_cgroup: no path or classid specified\n");
	47	return -EINVAL;
	48	}
	49
	50	if (info->has_path && info->has_classid) {
	51	pr_info("xt_cgroup: both path and classid specified\n");
	52	return -EINVAL;
	53	}
	54
b9e266e7	55	info->priv = NULL;
c38c4597 TH	56	if (info->has_path) {
	57	cgrp = cgroup_get_from_path(info->path);
	58	if (IS_ERR(cgrp)) {
	59	pr_info("xt_cgroup: invalid path, errno=%ld\n",
	60	PTR_ERR(cgrp));
	61	return -EINVAL;
	62	}
	63	info->priv = cgrp;
	64	}
	65
	66	return 0;
	67	}
	68
82a37132	69	static bool
4ec8ff0e	70	cgroup_mt_v0(const struct sk_buff skb, struct xt_action_param par)
82a37132	71	{
4ec8ff0e	72	const struct xt_cgroup_info_v0 *info = par->matchinfo;
82a37132	73
afb77180	74	if (skb->sk == NULL \|\| !sk_fullsock(skb->sk))
82a37132 DB	75	return false;
82a37132 DB	76
2a56a1fe TH	77	return (info->id == sock_cgroup_classid(&skb->sk->sk_cgrp_data)) ^
2a56a1fe TH	78	info->invert;
82a37132 DB	79	}
82a37132 DB	80
c38c4597 TH	81	static bool cgroup_mt_v1(const struct sk_buff skb, struct xt_action_param par)
	82	{
	83	const struct xt_cgroup_info_v1 *info = par->matchinfo;
	84	struct sock_cgroup_data *skcd = &skb->sk->sk_cgrp_data;
	85	struct cgroup *ancestor = info->priv;
	86
	87	if (!skb->sk \|\| !sk_fullsock(skb->sk))
	88	return false;
	89
	90	if (ancestor)
	91	return cgroup_is_descendant(sock_cgroup_ptr(skcd), ancestor) ^
	92	info->invert_path;
	93	else
	94	return (info->classid == sock_cgroup_classid(skcd)) ^
	95	info->invert_classid;
	96	}
	97
	98	static void cgroup_mt_destroy_v1(const struct xt_mtdtor_param *par)
	99	{
	100	struct xt_cgroup_info_v1 *info = par->matchinfo;
	101
	102	if (info->priv)
	103	cgroup_put(info->priv);
	104	}
	105
4ec8ff0e TH	106	static struct xt_match cgroup_mt_reg[] __read_mostly = {
	107	{
	108	.name = "cgroup",
	109	.revision = 0,
	110	.family = NFPROTO_UNSPEC,
	111	.checkentry = cgroup_mt_check_v0,
	112	.match = cgroup_mt_v0,
	113	.matchsize = sizeof(struct xt_cgroup_info_v0),
	114	.me = THIS_MODULE,
	115	.hooks = (1 << NF_INET_LOCAL_OUT) \|
	116	(1 << NF_INET_POST_ROUTING) \|
	117	(1 << NF_INET_LOCAL_IN),
	118	},
c38c4597 TH	119	{
	120	.name = "cgroup",
	121	.revision = 1,
	122	.family = NFPROTO_UNSPEC,
	123	.checkentry = cgroup_mt_check_v1,
	124	.match = cgroup_mt_v1,
	125	.matchsize = sizeof(struct xt_cgroup_info_v1),
ec231890	126	.usersize = offsetof(struct xt_cgroup_info_v1, priv),
c38c4597 TH	127	.destroy = cgroup_mt_destroy_v1,
	128	.me = THIS_MODULE,
	129	.hooks = (1 << NF_INET_LOCAL_OUT) \|
	130	(1 << NF_INET_POST_ROUTING) \|
	131	(1 << NF_INET_LOCAL_IN),
	132	},
82a37132 DB	133	};
	134
	135	static int __init cgroup_mt_init(void)
	136	{
4ec8ff0e	137	return xt_register_matches(cgroup_mt_reg, ARRAY_SIZE(cgroup_mt_reg));
82a37132 DB	138	}
	139
	140	static void __exit cgroup_mt_exit(void)
	141	{
4ec8ff0e	142	xt_unregister_matches(cgroup_mt_reg, ARRAY_SIZE(cgroup_mt_reg));
82a37132 DB	143	}
	144
	145	module_init(cgroup_mt_init);
	146	module_exit(cgroup_mt_exit);