Commit 83e96d44 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: log: split family specific code to nf_log_{ip,ip6,common}.c files 



The plain text logging is currently embedded into the xt_LOG target.
In order to be able to use the plain text logging from nft_log, as a
first step, this patch moves the family specific code to the following
files and Kconfig symbols:

1) net/ipv4/netfilter/nf_log_ip.c: CONFIG_NF_LOG_IPV4
2) net/ipv6/netfilter/nf_log_ip6.c: CONFIG_NF_LOG_IPV6
3) net/netfilter/nf_log_common.c: CONFIG_NF_LOG_COMMON

These new modules will be required by xt_LOG and nft_log. This patch
is based on original patch from Arturo Borrero Gonzalez.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 27fd8d90

include/net/netfilter/nf_log.h

+28 −0
Original line number Diff line number Diff line
@@ -78,4 +78,32 @@ struct nf_log_buf *nf_log_buf_open(void); 
__printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...);

void nf_log_buf_close(struct nf_log_buf *m);



void nf_log_ip_packet(struct net *net, u_int8_t pf,

		      unsigned int hooknum, const struct sk_buff *skb,

		      const struct net_device *in,

		      const struct net_device *out,

		      const struct nf_loginfo *loginfo,

		      const char *prefix);



void nf_log_ip6_packet(struct net *net, u_int8_t pf,

		       unsigned int hooknum, const struct sk_buff *skb,

		       const struct net_device *in,

		       const struct net_device *out,

		       const struct nf_loginfo *loginfo,

		       const char *prefix);



/* common logging functions */

int nf_log_dump_udp_header(struct nf_log_buf *m, const struct sk_buff *skb,

			   u8 proto, int fragment, unsigned int offset);

int nf_log_dump_tcp_header(struct nf_log_buf *m, const struct sk_buff *skb,

			   u8 proto, int fragment, unsigned int offset,

			   unsigned int logflags);

void nf_log_dump_sk_uid_gid(struct nf_log_buf *m, struct sock *sk);

void nf_log_dump_packet_common(struct nf_log_buf *m, u_int8_t pf,

			       unsigned int hooknum, const struct sk_buff *skb,

			       const struct net_device *in,

			       const struct net_device *out,

			       const struct nf_loginfo *loginfo,

			       const char *prefix);



#endif /* _NF_LOG_H */

net/ipv4/netfilter/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -159,6 +159,11 @@ config IP_NF_TARGET_SYNPROXY 


	  To compile it as a module, choose M here. If unsure, say N.



config NF_LOG_IPV4

	tristate "IPv4 packet logging"

	default m if NETFILTER_ADVANCED=n

	select NF_LOG_COMMON



# NAT + specific targets: nf_conntrack

config NF_NAT_IPV4

	tristate "IPv4 NAT"

net/ipv4/netfilter/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -19,6 +19,9 @@ obj-$(CONFIG_NF_NAT_IPV4) += nf_nat_ipv4.o 
# defrag

obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o



# logging

obj-$(CONFIG_NF_LOG_IPV4) += nf_log_ipv4.o



# NAT helpers (nf_conntrack)

obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o

obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o

net/ipv4/netfilter/nf_log_ipv4.c

0 → 100644
+385 −0
Original line number Diff line number Diff line 
/* (C) 1999-2001 Paul `Rusty' Russell

 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>

 *

 * 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/module.h>

#include <linux/spinlock.h>

#include <linux/skbuff.h>

#include <linux/if_arp.h>

#include <linux/ip.h>

#include <net/ipv6.h>

#include <net/icmp.h>

#include <net/udp.h>

#include <net/tcp.h>

#include <net/route.h>



#include <linux/netfilter.h>

#include <linux/netfilter/xt_LOG.h>

#include <net/netfilter/nf_log.h>



static struct nf_loginfo default_loginfo = {

	.type	= NF_LOG_TYPE_LOG,

	.u = {

		.log = {

			.level	  = 5,

			.logflags = NF_LOG_MASK,

		},

	},

};



/* One level of recursion won't kill us */

static void dump_ipv4_packet(struct nf_log_buf *m,

			     const struct nf_loginfo *info,

			     const struct sk_buff *skb, unsigned int iphoff)

{

	struct iphdr _iph;

	const struct iphdr *ih;

	unsigned int logflags;



	if (info->type == NF_LOG_TYPE_LOG)

		logflags = info->u.log.logflags;

	else

		logflags = NF_LOG_MASK;



	ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);

	if (ih == NULL) {

		nf_log_buf_add(m, "TRUNCATED");

		return;

	}



	/* Important fields:

	 * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */

	/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */

	nf_log_buf_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr);



	/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */

	nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",

		       ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,

		       ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));



	/* Max length: 6 "CE DF MF " */

	if (ntohs(ih->frag_off) & IP_CE)

		nf_log_buf_add(m, "CE ");

	if (ntohs(ih->frag_off) & IP_DF)

		nf_log_buf_add(m, "DF ");

	if (ntohs(ih->frag_off) & IP_MF)

		nf_log_buf_add(m, "MF ");



	/* Max length: 11 "FRAG:65535 " */

	if (ntohs(ih->frag_off) & IP_OFFSET)

		nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);



	if ((logflags & XT_LOG_IPOPT) &&

	    ih->ihl * 4 > sizeof(struct iphdr)) {

		const unsigned char *op;

		unsigned char _opt[4 * 15 - sizeof(struct iphdr)];

		unsigned int i, optsize;



		optsize = ih->ihl * 4 - sizeof(struct iphdr);

		op = skb_header_pointer(skb, iphoff+sizeof(_iph),

					optsize, _opt);

		if (op == NULL) {

			nf_log_buf_add(m, "TRUNCATED");

			return;

		}



		/* Max length: 127 "OPT (" 15*4*2chars ") " */

		nf_log_buf_add(m, "OPT (");

		for (i = 0; i < optsize; i++)

			nf_log_buf_add(m, "%02X", op[i]);

		nf_log_buf_add(m, ") ");

	}



	switch (ih->protocol) {

	case IPPROTO_TCP:

		if (nf_log_dump_tcp_header(m, skb, ih->protocol,

					   ntohs(ih->frag_off) & IP_OFFSET,

					   iphoff+ih->ihl*4, logflags))

			return;

		break;

	case IPPROTO_UDP:

	case IPPROTO_UDPLITE:

		if (nf_log_dump_udp_header(m, skb, ih->protocol,

					   ntohs(ih->frag_off) & IP_OFFSET,

					   iphoff+ih->ihl*4))

			return;

		break;

	case IPPROTO_ICMP: {

		struct icmphdr _icmph;

		const struct icmphdr *ich;

		static const size_t required_len[NR_ICMP_TYPES+1]

			= { [ICMP_ECHOREPLY] = 4,

			    [ICMP_DEST_UNREACH]

			    = 8 + sizeof(struct iphdr),

			    [ICMP_SOURCE_QUENCH]

			    = 8 + sizeof(struct iphdr),

			    [ICMP_REDIRECT]

			    = 8 + sizeof(struct iphdr),

			    [ICMP_ECHO] = 4,

			    [ICMP_TIME_EXCEEDED]

			    = 8 + sizeof(struct iphdr),

			    [ICMP_PARAMETERPROB]

			    = 8 + sizeof(struct iphdr),

			    [ICMP_TIMESTAMP] = 20,

			    [ICMP_TIMESTAMPREPLY] = 20,

			    [ICMP_ADDRESS] = 12,

			    [ICMP_ADDRESSREPLY] = 12 };



		/* Max length: 11 "PROTO=ICMP " */

		nf_log_buf_add(m, "PROTO=ICMP ");



		if (ntohs(ih->frag_off) & IP_OFFSET)

			break;



		/* Max length: 25 "INCOMPLETE [65535 bytes] " */

		ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,

					 sizeof(_icmph), &_icmph);

		if (ich == NULL) {

			nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",

				       skb->len - iphoff - ih->ihl*4);

			break;

		}



		/* Max length: 18 "TYPE=255 CODE=255 " */

		nf_log_buf_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code);



		/* Max length: 25 "INCOMPLETE [65535 bytes] " */

		if (ich->type <= NR_ICMP_TYPES &&

		    required_len[ich->type] &&

		    skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {

			nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",

				       skb->len - iphoff - ih->ihl*4);

			break;

		}



		switch (ich->type) {

		case ICMP_ECHOREPLY:

		case ICMP_ECHO:

			/* Max length: 19 "ID=65535 SEQ=65535 " */

			nf_log_buf_add(m, "ID=%u SEQ=%u ",

				       ntohs(ich->un.echo.id),

				       ntohs(ich->un.echo.sequence));

			break;



		case ICMP_PARAMETERPROB:

			/* Max length: 14 "PARAMETER=255 " */

			nf_log_buf_add(m, "PARAMETER=%u ",

				       ntohl(ich->un.gateway) >> 24);

			break;

		case ICMP_REDIRECT:

			/* Max length: 24 "GATEWAY=255.255.255.255 " */

			nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);

			/* Fall through */

		case ICMP_DEST_UNREACH:

		case ICMP_SOURCE_QUENCH:

		case ICMP_TIME_EXCEEDED:

			/* Max length: 3+maxlen */

			if (!iphoff) { /* Only recurse once. */

				nf_log_buf_add(m, "[");

				dump_ipv4_packet(m, info, skb,

					    iphoff + ih->ihl*4+sizeof(_icmph));

				nf_log_buf_add(m, "] ");

			}



			/* Max length: 10 "MTU=65535 " */

			if (ich->type == ICMP_DEST_UNREACH &&

			    ich->code == ICMP_FRAG_NEEDED) {

				nf_log_buf_add(m, "MTU=%u ",

					       ntohs(ich->un.frag.mtu));

			}

		}

		break;

	}

	/* Max Length */

	case IPPROTO_AH: {

		struct ip_auth_hdr _ahdr;

		const struct ip_auth_hdr *ah;



		if (ntohs(ih->frag_off) & IP_OFFSET)

			break;



		/* Max length: 9 "PROTO=AH " */

		nf_log_buf_add(m, "PROTO=AH ");



		/* Max length: 25 "INCOMPLETE [65535 bytes] " */

		ah = skb_header_pointer(skb, iphoff+ih->ihl*4,

					sizeof(_ahdr), &_ahdr);

		if (ah == NULL) {

			nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",

				       skb->len - iphoff - ih->ihl*4);

			break;

		}



		/* Length: 15 "SPI=0xF1234567 " */

		nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi));

		break;

	}

	case IPPROTO_ESP: {

		struct ip_esp_hdr _esph;

		const struct ip_esp_hdr *eh;



		/* Max length: 10 "PROTO=ESP " */

		nf_log_buf_add(m, "PROTO=ESP ");



		if (ntohs(ih->frag_off) & IP_OFFSET)

			break;



		/* Max length: 25 "INCOMPLETE [65535 bytes] " */

		eh = skb_header_pointer(skb, iphoff+ih->ihl*4,

					sizeof(_esph), &_esph);

		if (eh == NULL) {

			nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",

				       skb->len - iphoff - ih->ihl*4);

			break;

		}



		/* Length: 15 "SPI=0xF1234567 " */

		nf_log_buf_add(m, "SPI=0x%x ", ntohl(eh->spi));

		break;

	}

	/* Max length: 10 "PROTO 255 " */

	default:

		nf_log_buf_add(m, "PROTO=%u ", ih->protocol);

	}



	/* Max length: 15 "UID=4294967295 " */

	if ((logflags & XT_LOG_UID) && !iphoff)

		nf_log_dump_sk_uid_gid(m, skb->sk);



	/* Max length: 16 "MARK=0xFFFFFFFF " */

	if (!iphoff && skb->mark)

		nf_log_buf_add(m, "MARK=0x%x ", skb->mark);



	/* Proto    Max log string length */

	/* IP:	    40+46+6+11+127 = 230 */

	/* TCP:     10+max(25,20+30+13+9+32+11+127) = 252 */

	/* UDP:     10+max(25,20) = 35 */

	/* UDPLITE: 14+max(25,20) = 39 */

	/* ICMP:    11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */

	/* ESP:     10+max(25)+15 = 50 */

	/* AH:	    9+max(25)+15 = 49 */

	/* unknown: 10 */



	/* (ICMP allows recursion one level deep) */

	/* maxlen =  IP + ICMP +  IP + max(TCP,UDP,ICMP,unknown) */

	/* maxlen = 230+   91  + 230 + 252 = 803 */

}



static void dump_ipv4_mac_header(struct nf_log_buf *m,

			    const struct nf_loginfo *info,

			    const struct sk_buff *skb)

{

	struct net_device *dev = skb->dev;

	unsigned int logflags = 0;



	if (info->type == NF_LOG_TYPE_LOG)

		logflags = info->u.log.logflags;



	if (!(logflags & XT_LOG_MACDECODE))

		goto fallback;



	switch (dev->type) {

	case ARPHRD_ETHER:

		nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ",

			       eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,

			       ntohs(eth_hdr(skb)->h_proto));

		return;

	default:

		break;

	}



fallback:

	nf_log_buf_add(m, "MAC=");

	if (dev->hard_header_len &&

	    skb->mac_header != skb->network_header) {

		const unsigned char *p = skb_mac_header(skb);

		unsigned int i;



		nf_log_buf_add(m, "%02x", *p++);

		for (i = 1; i < dev->hard_header_len; i++, p++)

			nf_log_buf_add(m, ":%02x", *p);

	}

	nf_log_buf_add(m, " ");

}



void nf_log_ip_packet(struct net *net, u_int8_t pf,

		      unsigned int hooknum, const struct sk_buff *skb,

		      const struct net_device *in,

		      const struct net_device *out,

		      const struct nf_loginfo *loginfo,

		      const char *prefix)

{

	struct nf_log_buf *m;



	/* FIXME: Disabled from containers until syslog ns is supported */

	if (!net_eq(net, &init_net))

		return;



	m = nf_log_buf_open();



	if (!loginfo)

		loginfo = &default_loginfo;



	nf_log_dump_packet_common(m, pf, hooknum, skb, in,

				  out, loginfo, prefix);



	if (in != NULL)

		dump_ipv4_mac_header(m, loginfo, skb);



	dump_ipv4_packet(m, loginfo, skb, 0);



	nf_log_buf_close(m);

}

EXPORT_SYMBOL_GPL(nf_log_ip_packet);



static struct nf_logger nf_ip_logger __read_mostly = {

	.name		= "nf_log_ipv4",

	.type		= NF_LOG_TYPE_LOG,

	.logfn		= nf_log_ip_packet,

	.me		= THIS_MODULE,

};



static int __net_init nf_log_ipv4_net_init(struct net *net)

{

	nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);

	return 0;

}



static void __net_exit nf_log_ipv4_net_exit(struct net *net)

{

	nf_log_unset(net, &nf_ip_logger);

}



static struct pernet_operations nf_log_ipv4_net_ops = {

	.init = nf_log_ipv4_net_init,

	.exit = nf_log_ipv4_net_exit,

};



static int __init nf_log_ipv4_init(void)

{

	int ret;



	ret = register_pernet_subsys(&nf_log_ipv4_net_ops);

	if (ret < 0)

		return ret;



	nf_log_register(NFPROTO_IPV4, &nf_ip_logger);

	return 0;

}



static void __exit nf_log_ipv4_exit(void)

{

	unregister_pernet_subsys(&nf_log_ipv4_net_ops);

	nf_log_unregister(&nf_ip_logger);

}



module_init(nf_log_ipv4_init);

module_exit(nf_log_ipv4_exit);



MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");

MODULE_DESCRIPTION("Netfilter IPv4 packet logging");

MODULE_LICENSE("GPL");

net/ipv6/netfilter/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -227,6 +227,11 @@ config IP6_NF_SECURITY 


         If unsure, say N.



config NF_LOG_IPV6

	tristate "IPv6 packet logging"

	depends on NETFILTER_ADVANCED

	select NF_LOG_COMMON



config NF_NAT_IPV6

	tristate "IPv6 NAT"

	depends on NF_CONNTRACK_IPV6

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