[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 void audit_proto(struct audit_buffer *ab, struct sk_buff *skb,
			unsigned int proto, unsigned int offset)
{
	switch (proto) {
	case IPPROTO_TCP:
	case IPPROTO_UDP:
	case IPPROTO_UDPLITE: {
		const __be16 *pptr;
		__be16 _ports[2];

		pptr = skb_header_pointer(skb, offset, sizeof(_ports), _ports);
		if (pptr == NULL) {
			audit_log_format(ab, " truncated=1");
			return;
		}

		audit_log_format(ab, " sport=%hu dport=%hu",
				 ntohs(pptr[0]), ntohs(pptr[1]));
		}
		break;

	case IPPROTO_ICMP:
	case IPPROTO_ICMPV6: {
		const u8 *iptr;
		u8 _ih[2];

		iptr = skb_header_pointer(skb, offset, sizeof(_ih), &_ih);
		if (iptr == NULL) {
			audit_log_format(ab, " truncated=1");
			return;
		}

		audit_log_format(ab, " icmptype=%hhu icmpcode=%hhu",
				 iptr[0], iptr[1]);

		}
		break;
	}
}

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

	ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
	if (!ih) {
		audit_log_format(ab, " truncated=1");
		return;
	}

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

	if (ntohs(ih->frag_off) & IP_OFFSET) {
		audit_log_format(ab, " frag=1");
		return;
	}

	audit_proto(ab, skb, ih->protocol, ih->ihl * 4);
}

static void audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
{
	struct ipv6hdr _ip6h;
	const struct ipv6hdr *ih;
	u8 nexthdr;
	int offset;

	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
	if (!ih) {
		audit_log_format(ab, " truncated=1");
		return;
	}

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

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

	if (offset)
		audit_proto(ab, skb, nexthdr, offset);
}

static unsigned int
audit_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct xt_audit_info *info = par->targinfo;
	struct audit_buffer *ab;

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

	audit_log_format(ab, "action=%hhu hook=%u len=%u inif=%s outif=%s",
			 info->type, par->hooknum, skb->len,
			 par->in ? par->in->name : "?",
			 par->out ? par->out->name : "?");

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

	if (skb->dev && skb->dev->type == ARPHRD_ETHER) {
		audit_log_format(ab, " smac=%pM dmac=%pM macproto=0x%04x",
				 eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
				 ntohs(eth_hdr(skb)->h_proto));

		if (par->family == NFPROTO_BRIDGE) {
			switch (eth_hdr(skb)->h_proto) {
			case __constant_htons(ETH_P_IP):
				audit_ip4(ab, skb);
				break;

			case __constant_htons(ETH_P_IPV6):
				audit_ip6(ab, skb);
				break;
			}
		}
	}

	switch (par->family) {
	case NFPROTO_IPV4:
		audit_ip4(ab, skb);
		break;

	case NFPROTO_IPV6:
		audit_ip6(ab, skb);
		break;
	}

#ifdef CONFIG_NETWORK_SECMARK
	if (skb->secmark)
		audit_log_secctx(ab, skb->secmark);
#endif

	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
	34	static void audit_proto(struct audit_buffer ab, struct sk_buff skb,
	35	unsigned int proto, unsigned int offset)
	36	{
	37	switch (proto) {
	38	case IPPROTO_TCP:
	39	case IPPROTO_UDP:
	40	case IPPROTO_UDPLITE: {
	41	const __be16 *pptr;
	42	__be16 _ports[2];
	43
	44	pptr = skb_header_pointer(skb, offset, sizeof(_ports), _ports);
	45	if (pptr == NULL) {
	46	audit_log_format(ab, " truncated=1");
	47	return;
	48	}
	49
	50	audit_log_format(ab, " sport=%hu dport=%hu",
	51	ntohs(pptr[0]), ntohs(pptr[1]));
	52	}
	53	break;
	54
	55	case IPPROTO_ICMP:
	56	case IPPROTO_ICMPV6: {
	57	const u8 *iptr;
	58	u8 _ih[2];
	59
	60	iptr = skb_header_pointer(skb, offset, sizeof(_ih), &_ih);
	61	if (iptr == NULL) {
	62	audit_log_format(ab, " truncated=1");
	63	return;
	64	}
	65
	66	audit_log_format(ab, " icmptype=%hhu icmpcode=%hhu",
	67	iptr[0], iptr[1]);
	68
	69	}
	70	break;
	71	}
	72	}
	73
	74	static void audit_ip4(struct audit_buffer ab, struct sk_buff skb)
	75	{
	76	struct iphdr _iph;
	77	const struct iphdr *ih;
	78
	79	ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
	80	if (!ih) {
	81	audit_log_format(ab, " truncated=1");
	82	return;
	83	}
	84
	85	audit_log_format(ab, " saddr=%pI4 daddr=%pI4 ipid=%hu proto=%hhu",
	86	&ih->saddr, &ih->daddr, ntohs(ih->id), ih->protocol);
87
88	if (ntohs(ih->frag_off) & IP_OFFSET) {
89	audit_log_format(ab, " frag=1");
90	return;
91	}
92
93	audit_proto(ab, skb, ih->protocol, ih->ihl * 4);
94	}
95
96	static void audit_ip6(struct audit_buffer ab, struct sk_buff skb)
97	{
98	struct ipv6hdr _ip6h;
99	const struct ipv6hdr *ih;
100	u8 nexthdr;
101	int offset;
102
103	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
104	if (!ih) {
105	audit_log_format(ab, " truncated=1");
106	return;
107	}
108
109	nexthdr = ih->nexthdr;
110	offset = ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h),
111	&nexthdr);
112
113	audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
114	&ih->saddr, &ih->daddr, nexthdr);
115
116	if (offset)
117	audit_proto(ab, skb, nexthdr, offset);
118	}
119
120	static unsigned int
121	audit_tg(struct sk_buff skb, const struct xt_action_param par)
122	{
123	const struct xt_audit_info *info = par->targinfo;
124	struct audit_buffer *ab;
125
126	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
127	if (ab == NULL)
128	goto errout;
129
130	audit_log_format(ab, "action=%hhu hook=%u len=%u inif=%s outif=%s",
131	info->type, par->hooknum, skb->len,
132	par->in ? par->in->name : "?",
133	par->out ? par->out->name : "?");
134
135	if (skb->mark)
136	audit_log_format(ab, " mark=%#x", skb->mark);
137
138	if (skb->dev && skb->dev->type == ARPHRD_ETHER) {
139	audit_log_format(ab, " smac=%pM dmac=%pM macproto=0x%04x",
140	eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
141	ntohs(eth_hdr(skb)->h_proto));
142
143	if (par->family == NFPROTO_BRIDGE) {
144	switch (eth_hdr(skb)->h_proto) {
145	case __constant_htons(ETH_P_IP):
146	audit_ip4(ab, skb);
147	break;
148
149	case __constant_htons(ETH_P_IPV6):
150	audit_ip6(ab, skb);
151	break;
152	}
153	}
154	}
155
156	switch (par->family) {
157	case NFPROTO_IPV4:
158	audit_ip4(ab, skb);
159	break;
160
161	case NFPROTO_IPV6:
162	audit_ip6(ab, skb);
163	break;
164	}
165
131ad62d MDF	166	#ifdef CONFIG_NETWORK_SECMARK
	167	if (skb->secmark)
	168	audit_log_secctx(ab, skb->secmark);
	169	#endif
	170
43f393ca TG	171	audit_log_end(ab);
	172
	173	errout:
	174	return XT_CONTINUE;
	175	}
	176
400b871b TG	177	static unsigned int
	178	audit_tg_ebt(struct sk_buff skb, const struct xt_action_param par)
	179	{
	180	audit_tg(skb, par);
	181	return EBT_CONTINUE;
	182	}
	183
43f393ca TG	184	static int audit_tg_check(const struct xt_tgchk_param *par)
	185	{
	186	const struct xt_audit_info *info = par->targinfo;
	187
	188	if (info->type > XT_AUDIT_TYPE_MAX) {
	189	pr_info("Audit type out of range (valid range: 0..%hhu)\n",
	190	XT_AUDIT_TYPE_MAX);
	191	return -ERANGE;
	192	}
	193
	194	return 0;
	195	}
	196
400b871b TG	197	static struct xt_target audit_tg_reg[] __read_mostly = {
	198	{
	199	.name = "AUDIT",
	200	.family = NFPROTO_UNSPEC,
	201	.target = audit_tg,
	202	.targetsize = sizeof(struct xt_audit_info),
	203	.checkentry = audit_tg_check,
	204	.me = THIS_MODULE,
	205	},
	206	{
	207	.name = "AUDIT",
	208	.family = NFPROTO_BRIDGE,
	209	.target = audit_tg_ebt,
	210	.targetsize = sizeof(struct xt_audit_info),
	211	.checkentry = audit_tg_check,
	212	.me = THIS_MODULE,
	213	},
43f393ca TG	214	};
	215
	216	static int __init audit_tg_init(void)
	217	{
400b871b	218	return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
43f393ca TG	219	}
	220
	221	static void __exit audit_tg_exit(void)
	222	{
400b871b	223	xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
43f393ca TG	224	}
	225
	226	module_init(audit_tg_init);
	227	module_exit(audit_tg_exit);