[linux-2.6-block.git] / net / netfilter / nft_log.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 * Copyright (c) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

#include <linux/audit.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/ipv6.h>
#include <net/ip.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_log.h>
#include <linux/netdevice.h>

static const char *nft_log_null_prefix = "";

struct nft_log {
	struct nf_loginfo	loginfo;
	char			*prefix;
};

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 void nft_log_eval_audit(const struct nft_pktinfo *pkt)
{
	struct sk_buff *skb = pkt->skb;
	struct audit_buffer *ab;
	int fam = -1;

	if (!audit_enabled)
		return;

	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
	if (!ab)
		return;

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

	switch (nft_pf(pkt)) {
	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);
}

static void nft_log_eval(const struct nft_expr *expr,
			 struct nft_regs *regs,
			 const struct nft_pktinfo *pkt)
{
	const struct nft_log *priv = nft_expr_priv(expr);

	if (priv->loginfo.type == NF_LOG_TYPE_LOG &&
	    priv->loginfo.u.log.level == NFT_LOGLEVEL_AUDIT) {
		nft_log_eval_audit(pkt);
		return;
	}

	nf_log_packet(nft_net(pkt), nft_pf(pkt), nft_hook(pkt), pkt->skb,
		      nft_in(pkt), nft_out(pkt), &priv->loginfo, "%s",
		      priv->prefix);
}

static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
	[NFTA_LOG_GROUP]	= { .type = NLA_U16 },
	[NFTA_LOG_PREFIX]	= { .type = NLA_STRING,
				    .len = NF_LOG_PREFIXLEN - 1 },
	[NFTA_LOG_SNAPLEN]	= { .type = NLA_U32 },
	[NFTA_LOG_QTHRESHOLD]	= { .type = NLA_U16 },
	[NFTA_LOG_LEVEL]	= { .type = NLA_U32 },
	[NFTA_LOG_FLAGS]	= { .type = NLA_U32 },
};

static int nft_log_init(const struct nft_ctx *ctx,
			const struct nft_expr *expr,
			const struct nlattr * const tb[])
{
	struct nft_log *priv = nft_expr_priv(expr);
	struct nf_loginfo *li = &priv->loginfo;
	const struct nlattr *nla;
	int err;

	li->type = NF_LOG_TYPE_LOG;
	if (tb[NFTA_LOG_LEVEL] != NULL &&
	    tb[NFTA_LOG_GROUP] != NULL)
		return -EINVAL;
	if (tb[NFTA_LOG_GROUP] != NULL) {
		li->type = NF_LOG_TYPE_ULOG;
		if (tb[NFTA_LOG_FLAGS] != NULL)
			return -EINVAL;
	}

	nla = tb[NFTA_LOG_PREFIX];
	if (nla != NULL) {
		priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
		if (priv->prefix == NULL)
			return -ENOMEM;
		nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
	} else {
		priv->prefix = (char *)nft_log_null_prefix;
	}

	switch (li->type) {
	case NF_LOG_TYPE_LOG:
		if (tb[NFTA_LOG_LEVEL] != NULL) {
			li->u.log.level =
				ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL]));
		} else {
			li->u.log.level = NFT_LOGLEVEL_WARNING;
		}
		if (li->u.log.level > NFT_LOGLEVEL_AUDIT) {
			err = -EINVAL;
			goto err1;
		}

		if (tb[NFTA_LOG_FLAGS] != NULL) {
			li->u.log.logflags =
				ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
			if (li->u.log.logflags & ~NF_LOG_MASK) {
				err = -EINVAL;
				goto err1;
			}
		}
		break;
	case NF_LOG_TYPE_ULOG:
		li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
		if (tb[NFTA_LOG_SNAPLEN] != NULL) {
			li->u.ulog.flags |= NF_LOG_F_COPY_LEN;
			li->u.ulog.copy_len =
				ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
		}
		if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
			li->u.ulog.qthreshold =
				ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
		}
		break;
	}

	if (li->u.log.level == NFT_LOGLEVEL_AUDIT)
		return 0;

	err = nf_logger_find_get(ctx->family, li->type);
	if (err < 0)
		goto err1;

	return 0;

err1:
	if (priv->prefix != nft_log_null_prefix)
		kfree(priv->prefix);
	return err;
}

static void nft_log_destroy(const struct nft_ctx *ctx,
			    const struct nft_expr *expr)
{
	struct nft_log *priv = nft_expr_priv(expr);
	struct nf_loginfo *li = &priv->loginfo;

	if (priv->prefix != nft_log_null_prefix)
		kfree(priv->prefix);

	if (li->u.log.level == NFT_LOGLEVEL_AUDIT)
		return;

	nf_logger_put(ctx->family, li->type);
}

static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_log *priv = nft_expr_priv(expr);
	const struct nf_loginfo *li = &priv->loginfo;

	if (priv->prefix != nft_log_null_prefix)
		if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
			goto nla_put_failure;
	switch (li->type) {
	case NF_LOG_TYPE_LOG:
		if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
			goto nla_put_failure;

		if (li->u.log.logflags) {
			if (nla_put_be32(skb, NFTA_LOG_FLAGS,
					 htonl(li->u.log.logflags)))
				goto nla_put_failure;
		}
		break;
	case NF_LOG_TYPE_ULOG:
		if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
			goto nla_put_failure;

		if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) {
			if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
					 htonl(li->u.ulog.copy_len)))
				goto nla_put_failure;
		}
		if (li->u.ulog.qthreshold) {
			if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
					 htons(li->u.ulog.qthreshold)))
				goto nla_put_failure;
		}
		break;
	}
	return 0;

nla_put_failure:
	return -1;
}

static struct nft_expr_type nft_log_type;
static const struct nft_expr_ops nft_log_ops = {
	.type		= &nft_log_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_log)),
	.eval		= nft_log_eval,
	.init		= nft_log_init,
	.destroy	= nft_log_destroy,
	.dump		= nft_log_dump,
};

static struct nft_expr_type nft_log_type __read_mostly = {
	.name		= "log",
	.ops		= &nft_log_ops,
	.policy		= nft_log_policy,
	.maxattr	= NFTA_LOG_MAX,
	.owner		= THIS_MODULE,
};

static int __init nft_log_module_init(void)
{
	return nft_register_expr(&nft_log_type);
}

static void __exit nft_log_module_exit(void)
{
	nft_unregister_expr(&nft_log_type);
}

module_init(nft_log_module_init);
module_exit(nft_log_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("log");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
96518518	2	/*
ef1f7df9	3	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
09d27b88	4	* Copyright (c) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org>
96518518	5	*
96518518 PM	6	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	7	*/
	8
1a893b44	9	#include <linux/audit.h>
96518518 PM	10	#include <linux/kernel.h>
	11	#include <linux/init.h>
	12	#include <linux/module.h>
	13	#include <linux/netlink.h>
	14	#include <linux/netfilter.h>
	15	#include <linux/netfilter/nf_tables.h>
1a893b44 PS	16	#include <net/ipv6.h>
1a893b44 PS	17	#include <net/ip.h>
96518518 PM	18	#include <net/netfilter/nf_tables.h>
	19	#include <net/netfilter/nf_log.h>
	20	#include <linux/netdevice.h>
	21
	22	static const char *nft_log_null_prefix = "";
	23
	24	struct nft_log {
	25	struct nf_loginfo loginfo;
	26	char *prefix;
96518518 PM	27	};
96518518 PM	28
1a893b44 PS	29	static bool audit_ip4(struct audit_buffer ab, struct sk_buff skb)
	30	{
	31	struct iphdr _iph;
	32	const struct iphdr *ih;
	33
	34	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph);
	35	if (!ih)
	36	return false;
	37
	38	audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu",
	39	&ih->saddr, &ih->daddr, ih->protocol);
	40
	41	return true;
	42	}
	43
	44	static bool audit_ip6(struct audit_buffer ab, struct sk_buff skb)
	45	{
	46	struct ipv6hdr _ip6h;
	47	const struct ipv6hdr *ih;
	48	u8 nexthdr;
	49	__be16 frag_off;
	50
	51	ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
	52	if (!ih)
	53	return false;
	54
	55	nexthdr = ih->nexthdr;
	56	ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off);
	57
	58	audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
	59	&ih->saddr, &ih->daddr, nexthdr);
	60
	61	return true;
	62	}
	63
	64	static void nft_log_eval_audit(const struct nft_pktinfo *pkt)
	65	{
	66	struct sk_buff *skb = pkt->skb;
	67	struct audit_buffer *ab;
	68	int fam = -1;
	69
	70	if (!audit_enabled)
	71	return;
	72
	73	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
	74	if (!ab)
	75	return;
	76
	77	audit_log_format(ab, "mark=%#x", skb->mark);
	78
	79	switch (nft_pf(pkt)) {
	80	case NFPROTO_BRIDGE:
	81	switch (eth_hdr(skb)->h_proto) {
	82	case htons(ETH_P_IP):
	83	fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
	84	break;
	85	case htons(ETH_P_IPV6):
	86	fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
	87	break;
	88	}
	89	break;
	90	case NFPROTO_IPV4:
	91	fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
	92	break;
93	case NFPROTO_IPV6:
94	fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
95	break;
96	}
97
98	if (fam == -1)
99	audit_log_format(ab, " saddr=? daddr=? proto=-1");
100
101	audit_log_end(ab);
102	}
103
96518518	104	static void nft_log_eval(const struct nft_expr *expr,
a55e22e9	105	struct nft_regs *regs,
96518518 PM	106	const struct nft_pktinfo *pkt)
	107	{
	108	const struct nft_log *priv = nft_expr_priv(expr);
96518518	109
1a893b44	110	if (priv->loginfo.type == NF_LOG_TYPE_LOG &&
7eced5ab	111	priv->loginfo.u.log.level == NFT_LOGLEVEL_AUDIT) {
1a893b44 PS	112	nft_log_eval_audit(pkt);
	113	return;
	114	}
	115
0e5a1c7e PNA	116	nf_log_packet(nft_net(pkt), nft_pf(pkt), nft_hook(pkt), pkt->skb,
	117	nft_in(pkt), nft_out(pkt), &priv->loginfo, "%s",
	118	priv->prefix);
96518518 PM	119	}
	120
	121	static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
	122	[NFTA_LOG_GROUP] = { .type = NLA_U16 },
5ce6b04c LZ	123	[NFTA_LOG_PREFIX] = { .type = NLA_STRING,
5ce6b04c LZ	124	.len = NF_LOG_PREFIXLEN - 1 },
96518518 PM	125	[NFTA_LOG_SNAPLEN] = { .type = NLA_U32 },
96518518 PM	126	[NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 },
09d27b88 PNA	127	[NFTA_LOG_LEVEL] = { .type = NLA_U32 },
09d27b88 PNA	128	[NFTA_LOG_FLAGS] = { .type = NLA_U32 },
96518518 PM	129	};
	130
	131	static int nft_log_init(const struct nft_ctx *ctx,
	132	const struct nft_expr *expr,
	133	const struct nlattr * const tb[])
	134	{
	135	struct nft_log *priv = nft_expr_priv(expr);
	136	struct nf_loginfo *li = &priv->loginfo;
	137	const struct nlattr *nla;
c2d9a429 LZ	138	int err;
	139
	140	li->type = NF_LOG_TYPE_LOG;
	141	if (tb[NFTA_LOG_LEVEL] != NULL &&
	142	tb[NFTA_LOG_GROUP] != NULL)
	143	return -EINVAL;
ff107d27	144	if (tb[NFTA_LOG_GROUP] != NULL) {
c2d9a429	145	li->type = NF_LOG_TYPE_ULOG;
ff107d27 LZ	146	if (tb[NFTA_LOG_FLAGS] != NULL)
	147	return -EINVAL;
	148	}
96518518	149
96518518 PM	150	nla = tb[NFTA_LOG_PREFIX];
	151	if (nla != NULL) {
	152	priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
	153	if (priv->prefix == NULL)
	154	return -ENOMEM;
	155	nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
09d27b88	156	} else {
96518518	157	priv->prefix = (char *)nft_log_null_prefix;
09d27b88	158	}
96518518	159
09d27b88 PNA	160	switch (li->type) {
	161	case NF_LOG_TYPE_LOG:
	162	if (tb[NFTA_LOG_LEVEL] != NULL) {
	163	li->u.log.level =
5cbfda20	164	ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL]));
09d27b88	165	} else {
7eced5ab	166	li->u.log.level = NFT_LOGLEVEL_WARNING;
09d27b88	167	}
7eced5ab	168	if (li->u.log.level > NFT_LOGLEVEL_AUDIT) {
1bc4e013 LZ	169	err = -EINVAL;
	170	goto err1;
	171	}
	172
09d27b88 PNA	173	if (tb[NFTA_LOG_FLAGS] != NULL) {
	174	li->u.log.logflags =
	175	ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
ff107d27 LZ	176	if (li->u.log.logflags & ~NF_LOG_MASK) {
	177	err = -EINVAL;
	178	goto err1;
	179	}
09d27b88 PNA	180	}
	181	break;
	182	case NF_LOG_TYPE_ULOG:
96518518	183	li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
09d27b88	184	if (tb[NFTA_LOG_SNAPLEN] != NULL) {
cc37c1ad	185	li->u.ulog.flags \|= NF_LOG_F_COPY_LEN;
09d27b88 PNA	186	li->u.ulog.copy_len =
	187	ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
	188	}
	189	if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
	190	li->u.ulog.qthreshold =
	191	ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
	192	}
	193	break;
96518518 PM	194	}
96518518 PM	195
7eced5ab	196	if (li->u.log.level == NFT_LOGLEVEL_AUDIT)
1a893b44 PS	197	return 0;
1a893b44 PS	198
36596dad	199	err = nf_logger_find_get(ctx->family, li->type);
c2d9a429 LZ	200	if (err < 0)
	201	goto err1;
	202
	203	return 0;
	204
	205	err1:
	206	if (priv->prefix != nft_log_null_prefix)
	207	kfree(priv->prefix);
	208	return err;
96518518 PM	209	}
96518518 PM	210
62472bce PM	211	static void nft_log_destroy(const struct nft_ctx *ctx,
62472bce PM	212	const struct nft_expr *expr)
96518518 PM	213	{
96518518 PM	214	struct nft_log *priv = nft_expr_priv(expr);
85d30e24	215	struct nf_loginfo *li = &priv->loginfo;
96518518 PM	216
	217	if (priv->prefix != nft_log_null_prefix)
	218	kfree(priv->prefix);
85d30e24	219
7eced5ab	220	if (li->u.log.level == NFT_LOGLEVEL_AUDIT)
1a893b44 PS	221	return;
1a893b44 PS	222
36596dad	223	nf_logger_put(ctx->family, li->type);
96518518 PM	224	}
	225
	226	static int nft_log_dump(struct sk_buff skb, const struct nft_expr expr)
	227	{
	228	const struct nft_log *priv = nft_expr_priv(expr);
	229	const struct nf_loginfo *li = &priv->loginfo;
	230
	231	if (priv->prefix != nft_log_null_prefix)
	232	if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
	233	goto nla_put_failure;
09d27b88 PNA	234	switch (li->type) {
	235	case NF_LOG_TYPE_LOG:
	236	if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
96518518	237	goto nla_put_failure;
09d27b88 PNA	238
	239	if (li->u.log.logflags) {
	240	if (nla_put_be32(skb, NFTA_LOG_FLAGS,
	241	htonl(li->u.log.logflags)))
	242	goto nla_put_failure;
	243	}
	244	break;
	245	case NF_LOG_TYPE_ULOG:
	246	if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
96518518	247	goto nla_put_failure;
09d27b88	248
cc37c1ad	249	if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) {
09d27b88 PNA	250	if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
	251	htonl(li->u.ulog.copy_len)))
	252	goto nla_put_failure;
	253	}
	254	if (li->u.ulog.qthreshold) {
	255	if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
	256	htons(li->u.ulog.qthreshold)))
	257	goto nla_put_failure;
	258	}
	259	break;
	260	}
96518518 PM	261	return 0;
	262
	263	nla_put_failure:
	264	return -1;
	265	}
	266
ef1f7df9 PM	267	static struct nft_expr_type nft_log_type;
	268	static const struct nft_expr_ops nft_log_ops = {
	269	.type = &nft_log_type,
96518518	270	.size = NFT_EXPR_SIZE(sizeof(struct nft_log)),
96518518 PM	271	.eval = nft_log_eval,
	272	.init = nft_log_init,
	273	.destroy = nft_log_destroy,
	274	.dump = nft_log_dump,
ef1f7df9 PM	275	};
	276
	277	static struct nft_expr_type nft_log_type __read_mostly = {
	278	.name = "log",
	279	.ops = &nft_log_ops,
96518518 PM	280	.policy = nft_log_policy,
96518518 PM	281	.maxattr = NFTA_LOG_MAX,
ef1f7df9	282	.owner = THIS_MODULE,
96518518 PM	283	};
	284
	285	static int __init nft_log_module_init(void)
	286	{
ef1f7df9	287	return nft_register_expr(&nft_log_type);
96518518 PM	288	}
	289
	290	static void __exit nft_log_module_exit(void)
	291	{
ef1f7df9	292	nft_unregister_expr(&nft_log_type);
96518518 PM	293	}
	294
	295	module_init(nft_log_module_init);
	296	module_exit(nft_log_module_exit);
	297
	298	MODULE_LICENSE("GPL");
	299	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	300	MODULE_ALIAS_NFT_EXPR("log");