[linux.git] / net / netfilter / xt_AUDIT.c

/*
 * Creates audit record for dropped/accepted packets
 *
 * (C) 2010-2011 Thomas Graf <[email protected]>
 * (C) 2010-2011 Red Hat, Inc.
 *
 * 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/audit.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/if_arp.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_AUDIT.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <net/ipv6.h>
#include <net/ip.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Thomas Graf <[email protected]>");
MODULE_DESCRIPTION("Xtables: creates audit records for dropped/accepted packets");
MODULE_ALIAS("ipt_AUDIT");
MODULE_ALIAS("ip6t_AUDIT");
MODULE_ALIAS("ebt_AUDIT");
MODULE_ALIAS("arpt_AUDIT");

static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb)
{
	struct iphdr _iph;
	const struct iphdr *ih;

	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph);
	if (!ih)
		return false;

	audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu",
			 &ih->saddr, &ih->daddr, ih->protocol);

	return true;
}

static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
{
	struct ipv6hdr _ip6h;
	const struct ipv6hdr *ih;
	u8 nexthdr;
	__be16 frag_off;

	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
	if (!ih)
		return false;

	nexthdr = ih->nexthdr;
	ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off);

	audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
			 &ih->saddr, &ih->daddr, nexthdr);

	return true;
}

static unsigned int
audit_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	struct audit_buffer *ab;
	int fam = -1;

	if (audit_enabled == 0)
		goto errout;
	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
	if (ab == NULL)
		goto errout;

	audit_log_format(ab, "mark=%#x", skb->mark);

	switch (xt_family(par)) {
	case NFPROTO_BRIDGE:
		switch (eth_hdr(skb)->h_proto) {
		case htons(ETH_P_IP):
			fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
			break;
		case htons(ETH_P_IPV6):
			fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
			break;
		}
		break;
	case NFPROTO_IPV4:
		fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
		break;
	case NFPROTO_IPV6:
		fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
		break;
	}

	if (fam == -1)
		audit_log_format(ab, " saddr=? daddr=? proto=-1");

	audit_log_end(ab);

errout:
	return XT_CONTINUE;
}

static unsigned int
audit_tg_ebt(struct sk_buff *skb, const struct xt_action_param *par)
{
	audit_tg(skb, par);
	return EBT_CONTINUE;
}

static int audit_tg_check(const struct xt_tgchk_param *par)
{
	const struct xt_audit_info *info = par->targinfo;

	if (info->type > XT_AUDIT_TYPE_MAX) {
		pr_info("Audit type out of range (valid range: 0..%hhu)\n",
			XT_AUDIT_TYPE_MAX);
		return -ERANGE;
	}

	return 0;
}

static struct xt_target audit_tg_reg[] __read_mostly = {
	{
		.name		= "AUDIT",
		.family		= NFPROTO_UNSPEC,
		.target		= audit_tg,
		.targetsize	= sizeof(struct xt_audit_info),
		.checkentry	= audit_tg_check,
		.me		= THIS_MODULE,
	},
	{
		.name		= "AUDIT",
		.family		= NFPROTO_BRIDGE,
		.target		= audit_tg_ebt,
		.targetsize	= sizeof(struct xt_audit_info),
		.checkentry	= audit_tg_check,
		.me		= THIS_MODULE,
	},
};

static int __init audit_tg_init(void)
{
	return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
}

static void __exit audit_tg_exit(void)
{
	xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
}

module_init(audit_tg_init);
module_exit(audit_tg_exit);
Commit	Line	Data
43f393ca TG	1	/*
	2	* Creates audit record for dropped/accepted packets
	3	*
	4	* (C) 2010-2011 Thomas Graf <[email protected]>
	5	* (C) 2010-2011 Red Hat, Inc.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	13
	14	#include <linux/audit.h>
	15	#include <linux/module.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/tcp.h>
	18	#include <linux/udp.h>
	19	#include <linux/if_arp.h>
	20	#include <linux/netfilter/x_tables.h>
	21	#include <linux/netfilter/xt_AUDIT.h>
400b871b	22	#include <linux/netfilter_bridge/ebtables.h>
43f393ca TG	23	#include <net/ipv6.h>
	24	#include <net/ip.h>
	25
	26	MODULE_LICENSE("GPL");
	27	MODULE_AUTHOR("Thomas Graf <[email protected]>");
	28	MODULE_DESCRIPTION("Xtables: creates audit records for dropped/accepted packets");
	29	MODULE_ALIAS("ipt_AUDIT");
	30	MODULE_ALIAS("ip6t_AUDIT");
	31	MODULE_ALIAS("ebt_AUDIT");
	32	MODULE_ALIAS("arpt_AUDIT");
	33
2173c519	34	static bool audit_ip4(struct audit_buffer ab, struct sk_buff skb)
43f393ca TG	35	{
	36	struct iphdr _iph;
	37	const struct iphdr *ih;
	38
0cb88b6f	39	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph);
2173c519 RGB	40	if (!ih)
2173c519 RGB	41	return false;
43f393ca	42
2173c519 RGB	43	audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu",
2173c519 RGB	44	&ih->saddr, &ih->daddr, ih->protocol);
43f393ca	45
2173c519	46	return true;
43f393ca TG	47	}
43f393ca TG	48
2173c519	49	static bool audit_ip6(struct audit_buffer ab, struct sk_buff skb)
43f393ca TG	50	{
	51	struct ipv6hdr _ip6h;
	52	const struct ipv6hdr *ih;
	53	u8 nexthdr;
75f2811c	54	__be16 frag_off;
43f393ca TG	55
43f393ca TG	56	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
2173c519 RGB	57	if (!ih)
2173c519 RGB	58	return false;
43f393ca TG	59
43f393ca TG	60	nexthdr = ih->nexthdr;
2173c519	61	ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off);
43f393ca TG	62
	63	audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
	64	&ih->saddr, &ih->daddr, nexthdr);
	65
2173c519	66	return true;
43f393ca TG	67	}
	68
	69	static unsigned int
	70	audit_tg(struct sk_buff skb, const struct xt_action_param par)
	71	{
43f393ca	72	struct audit_buffer *ab;
2173c519	73	int fam = -1;
43f393ca	74
ed018fa4 G	75	if (audit_enabled == 0)
ed018fa4 G	76	goto errout;
43f393ca TG	77	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
	78	if (ab == NULL)
	79	goto errout;
	80
2173c519	81	audit_log_format(ab, "mark=%#x", skb->mark);
43f393ca	82
613dbd95	83	switch (xt_family(par)) {
2173c519 RGB	84	case NFPROTO_BRIDGE:
	85	switch (eth_hdr(skb)->h_proto) {
	86	case htons(ETH_P_IP):
	87	fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
	88	break;
	89	case htons(ETH_P_IPV6):
	90	fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
	91	break;
	92	}
	93	break;
43f393ca	94	case NFPROTO_IPV4:
2173c519	95	fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
43f393ca	96	break;
43f393ca	97	case NFPROTO_IPV6:
2173c519	98	fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
43f393ca TG	99	break;
	100	}
	101
2173c519 RGB	102	if (fam == -1)
2173c519 RGB	103	audit_log_format(ab, " saddr=? daddr=? proto=-1");
131ad62d	104
43f393ca TG	105	audit_log_end(ab);
	106
	107	errout:
	108	return XT_CONTINUE;
	109	}
	110
400b871b TG	111	static unsigned int
	112	audit_tg_ebt(struct sk_buff skb, const struct xt_action_param par)
	113	{
	114	audit_tg(skb, par);
	115	return EBT_CONTINUE;
	116	}
	117
43f393ca TG	118	static int audit_tg_check(const struct xt_tgchk_param *par)
	119	{
	120	const struct xt_audit_info *info = par->targinfo;
	121
	122	if (info->type > XT_AUDIT_TYPE_MAX) {
	123	pr_info("Audit type out of range (valid range: 0..%hhu)\n",
	124	XT_AUDIT_TYPE_MAX);
	125	return -ERANGE;
	126	}
	127
	128	return 0;
	129	}
	130
400b871b TG	131	static struct xt_target audit_tg_reg[] __read_mostly = {
	132	{
	133	.name = "AUDIT",
	134	.family = NFPROTO_UNSPEC,
	135	.target = audit_tg,
	136	.targetsize = sizeof(struct xt_audit_info),
	137	.checkentry = audit_tg_check,
	138	.me = THIS_MODULE,
	139	},
	140	{
	141	.name = "AUDIT",
	142	.family = NFPROTO_BRIDGE,
	143	.target = audit_tg_ebt,
	144	.targetsize = sizeof(struct xt_audit_info),
	145	.checkentry = audit_tg_check,
	146	.me = THIS_MODULE,
	147	},
43f393ca TG	148	};
	149
	150	static int __init audit_tg_init(void)
	151	{
400b871b	152	return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
43f393ca TG	153	}
	154
	155	static void __exit audit_tg_exit(void)
	156	{
400b871b	157	xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
43f393ca TG	158	}
	159
	160	module_init(audit_tg_init);
	161	module_exit(audit_tg_exit);