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netfilter: merge ipt_LOG and ip6_LOG into xt_LOG

Browse Source 
ipt_LOG and ip6_LOG have a lot of common code, merge them
to reduce duplicate code.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Richard Weinberger 2012-02-10 23:10:52 +01:00 committed by Pablo Neira Ayuso
parent 544d5c7d9f
commit 6939c33a75
13 changed files with 955 additions and 1063 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/netfilter/Kbuild
View File

@ -22,6 +22,7 @@ header-y += xt_CT.h
header-y += xt_DSCP.h
header-y += xt_IDLETIMER.h
header-y += xt_LED.h
header-y += xt_LOG.h
header-y += xt_MARK.h
header-y += xt_nfacct.h
header-y += xt_NFLOG.h

19
include/linux/netfilter/xt_LOG.h Normal file
View File

@ -0,0 +1,19 @@
#ifndef _XT_LOG_H
#define _XT_LOG_H
/* make sure not to change this without changing nf_log.h:NF_LOG_* (!) */
#define XT_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
#define XT_LOG_TCPOPT 0x02 /* Log TCP options */
#define XT_LOG_IPOPT 0x04 /* Log IP options */
#define XT_LOG_UID 0x08 /* Log UID owning local socket */
#define XT_LOG_NFLOG 0x10 /* Unsupported, don't reuse */
#define XT_LOG_MACDECODE 0x20 /* Decode MAC header */
#define XT_LOG_MASK 0x2f
struct xt_log_info {
unsigned char level;
unsigned char logflags;
char prefix[30];
};
#endif /* _XT_LOG_H */

2
include/linux/netfilter_ipv4/ipt_LOG.h
View File

@ -1,6 +1,8 @@
#ifndef _IPT_LOG_H
#define _IPT_LOG_H
#warning "Please update iptables, this file will be removed soon!"
/* make sure not to change this without changing netfilter.h:NF_LOG_* (!) */
#define IPT_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
#define IPT_LOG_TCPOPT 0x02 /* Log TCP options */

2
include/linux/netfilter_ipv6/ip6t_LOG.h
View File

@ -1,6 +1,8 @@
#ifndef _IP6T_LOG_H
#define _IP6T_LOG_H
#warning "Please update iptables, this file will be removed soon!"
/* make sure not to change this without changing netfilter.h:NF_LOG_* (!) */
#define IP6T_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
#define IP6T_LOG_TCPOPT 0x02 /* Log TCP options */

9
net/ipv4/netfilter/Kconfig
View File

@ -123,15 +123,6 @@ config IP_NF_TARGET_REJECT
To compile it as a module, choose M here. If unsure, say N.
config IP_NF_TARGET_LOG
tristate "LOG target support"
default m if NETFILTER_ADVANCED=n
help
This option adds a `LOG' target, which allows you to create rules in
any iptables table which records the packet header to the syslog.
To compile it as a module, choose M here. If unsure, say N.
config IP_NF_TARGET_ULOG
tristate "ULOG target support"
default m if NETFILTER_ADVANCED=n

1
net/ipv4/netfilter/Makefile
View File

@ -54,7 +54,6 @@ obj-$(CONFIG_IP_NF_MATCH_RPFILTER) += ipt_rpfilter.o
# targets
obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_ECN.o
obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o

516
net/ipv4/netfilter/ipt_LOG.c
View File

@ -1,516 +0,0 @@
/*
* This is a module which is used for logging packets.
*/
/* (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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <net/route.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ipt_LOG.h>
#include <net/netfilter/nf_log.h>
#include <net/netfilter/xt_log.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("Xtables: IPv4 packet logging to syslog");
/* One level of recursion won't kill us */
static void dump_packet(struct sbuff *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) {
sb_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 " */
sb_add(m, "SRC=%pI4 DST=%pI4 ",
&ih->saddr, &ih->daddr);
/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
sb_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)
sb_add(m, "CE ");
if (ntohs(ih->frag_off) & IP_DF)
sb_add(m, "DF ");
if (ntohs(ih->frag_off) & IP_MF)
sb_add(m, "MF ");
/* Max length: 11 "FRAG:65535 " */
if (ntohs(ih->frag_off) & IP_OFFSET)
sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
if ((logflags & IPT_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) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 127 "OPT (" 15*4*2chars ") " */
sb_add(m, "OPT (");
for (i = 0; i < optsize; i++)
sb_add(m, "%02X", op[i]);
sb_add(m, ") ");
}
switch (ih->protocol) {
case IPPROTO_TCP: {
struct tcphdr _tcph;
const struct tcphdr *th;
/* Max length: 10 "PROTO=TCP " */
sb_add(m, "PROTO=TCP ");
if (ntohs(ih->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
th = skb_header_pointer(skb, iphoff + ih->ihl * 4,
sizeof(_tcph), &_tcph);
if (th == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Max length: 20 "SPT=65535 DPT=65535 " */
sb_add(m, "SPT=%u DPT=%u ",
ntohs(th->source), ntohs(th->dest));
/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
if (logflags & IPT_LOG_TCPSEQ)
sb_add(m, "SEQ=%u ACK=%u ",
ntohl(th->seq), ntohl(th->ack_seq));
/* Max length: 13 "WINDOW=65535 " */
sb_add(m, "WINDOW=%u ", ntohs(th->window));
/* Max length: 9 "RES=0x3F " */
sb_add(m, "RES=0x%02x ", (u8)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
if (th->cwr)
sb_add(m, "CWR ");
if (th->ece)
sb_add(m, "ECE ");
if (th->urg)
sb_add(m, "URG ");
if (th->ack)
sb_add(m, "ACK ");
if (th->psh)
sb_add(m, "PSH ");
if (th->rst)
sb_add(m, "RST ");
if (th->syn)
sb_add(m, "SYN ");
if (th->fin)
sb_add(m, "FIN ");
/* Max length: 11 "URGP=65535 " */
sb_add(m, "URGP=%u ", ntohs(th->urg_ptr));
if ((logflags & IPT_LOG_TCPOPT) &&
th->doff * 4 > sizeof(struct tcphdr)) {
unsigned char _opt[4 * 15 - sizeof(struct tcphdr)];
const unsigned char *op;
unsigned int i, optsize;
optsize = th->doff * 4 - sizeof(struct tcphdr);
op = skb_header_pointer(skb,
iphoff+ih->ihl*4+sizeof(_tcph),
optsize, _opt);
if (op == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 127 "OPT (" 15*4*2chars ") " */
sb_add(m, "OPT (");
for (i = 0; i < optsize; i++)
sb_add(m, "%02X", op[i]);
sb_add(m, ") ");
}
break;
}
case IPPROTO_UDP:
case IPPROTO_UDPLITE: {
struct udphdr _udph;
const struct udphdr *uh;
if (ih->protocol == IPPROTO_UDP)
/* Max length: 10 "PROTO=UDP " */
sb_add(m, "PROTO=UDP " );
else /* Max length: 14 "PROTO=UDPLITE " */
sb_add(m, "PROTO=UDPLITE ");
if (ntohs(ih->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
uh = skb_header_pointer(skb, iphoff+ih->ihl*4,
sizeof(_udph), &_udph);
if (uh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Max length: 20 "SPT=65535 DPT=65535 " */
sb_add(m, "SPT=%u DPT=%u LEN=%u ",
ntohs(uh->source), ntohs(uh->dest),
ntohs(uh->len));
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 " */
sb_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) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
sb_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]) {
sb_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 " */
sb_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 " */
sb_add(m, "PARAMETER=%u ",
ntohl(ich->un.gateway) >> 24);
break;
case ICMP_REDIRECT:
/* Max length: 24 "GATEWAY=255.255.255.255 " */
sb_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. */
sb_add(m, "[");
dump_packet(m, info, skb,
iphoff + ih->ihl*4+sizeof(_icmph));
sb_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ich->type == ICMP_DEST_UNREACH &&
ich->code == ICMP_FRAG_NEEDED)
sb_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 " */
sb_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) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
sb_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 " */
sb_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) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
sb_add(m, "SPI=0x%x ", ntohl(eh->spi));
break;
}
/* Max length: 10 "PROTO 255 " */
default:
sb_add(m, "PROTO=%u ", ih->protocol);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket && skb->sk->sk_socket->file)
sb_add(m, "UID=%u GID=%u ",
skb->sk->sk_socket->file->f_cred->fsuid,
skb->sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&skb->sk->sk_callback_lock);
}
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (!iphoff && skb->mark)
sb_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_mac_header(struct sbuff *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 & IPT_LOG_MACDECODE))
goto fallback;
switch (dev->type) {
case ARPHRD_ETHER:
sb_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:
sb_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;
sb_add(m, "%02x", *p++);
for (i = 1; i < dev->hard_header_len; i++, p++)
sb_add(m, ":%02x", *p);
}
sb_add(m, " ");
}
static struct nf_loginfo default_loginfo = {
.type = NF_LOG_TYPE_LOG,
.u = {
.log = {
.level = 5,
.logflags = NF_LOG_MASK,
},
},
};
static void
ipt_log_packet(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 sbuff *m = sb_open();
if (!loginfo)
loginfo = &default_loginfo;
sb_add(m, "<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
prefix,
in ? in->name : "",
out ? out->name : "");
#ifdef CONFIG_BRIDGE_NETFILTER
if (skb->nf_bridge) {
const struct net_device *physindev;
const struct net_device *physoutdev;
physindev = skb->nf_bridge->physindev;
if (physindev && in != physindev)
sb_add(m, "PHYSIN=%s ", physindev->name);
physoutdev = skb->nf_bridge->physoutdev;
if (physoutdev && out != physoutdev)
sb_add(m, "PHYSOUT=%s ", physoutdev->name);
}
#endif
if (in != NULL)
dump_mac_header(m, loginfo, skb);
dump_packet(m, loginfo, skb, 0);
sb_close(m);
}
static unsigned int
log_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct ipt_log_info *loginfo = par->targinfo;
struct nf_loginfo li;
li.type = NF_LOG_TYPE_LOG;
li.u.log.level = loginfo->level;
li.u.log.logflags = loginfo->logflags;
ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, par->out, &li,
loginfo->prefix);
return XT_CONTINUE;
}
static int log_tg_check(const struct xt_tgchk_param *par)
{
const struct ipt_log_info *loginfo = par->targinfo;
if (loginfo->level >= 8) {
pr_debug("level %u >= 8\n", loginfo->level);
return -EINVAL;
}
if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
pr_debug("prefix is not null-terminated\n");
return -EINVAL;
}
return 0;
}
static struct xt_target log_tg_reg __read_mostly = {
.name = "LOG",
.family = NFPROTO_IPV4,
.target = log_tg,
.targetsize = sizeof(struct ipt_log_info),
.checkentry = log_tg_check,
.me = THIS_MODULE,
};
static struct nf_logger ipt_log_logger __read_mostly = {
.name = "ipt_LOG",
.logfn = &ipt_log_packet,
.me = THIS_MODULE,
};
static int __init log_tg_init(void)
{
int ret;
ret = xt_register_target(&log_tg_reg);
if (ret < 0)
return ret;
nf_log_register(NFPROTO_IPV4, &ipt_log_logger);
return 0;
}
static void __exit log_tg_exit(void)
{
nf_log_unregister(&ipt_log_logger);
xt_unregister_target(&log_tg_reg);
}
module_init(log_tg_init);
module_exit(log_tg_exit);

9
net/ipv6/netfilter/Kconfig
View File

@ -154,15 +154,6 @@ config IP6_NF_TARGET_HL
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_TARGET_HL.
config IP6_NF_TARGET_LOG
tristate "LOG target support"
default m if NETFILTER_ADVANCED=n
help
This option adds a `LOG' target, which allows you to create rules in
any iptables table which records the packet header to the syslog.
To compile it as a module, choose M here. If unsure, say N.
config IP6_NF_FILTER
tristate "Packet filtering"
default m if NETFILTER_ADVANCED=n

1
net/ipv6/netfilter/Makefile
View File

@ -31,5 +31,4 @@ obj-$(CONFIG_IP6_NF_MATCH_RPFILTER) += ip6t_rpfilter.o
obj-$(CONFIG_IP6_NF_MATCH_RT) += ip6t_rt.o
# targets
obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_LOG.o
obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o

527
net/ipv6/netfilter/ip6t_LOG.c
View File

@ -1,527 +0,0 @@
/*
* This is a module which is used for logging packets.
*/
/* (C) 2001 Jan Rekorajski <baggins@pld.org.pl>
* (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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <linux/spinlock.h>
#include <linux/icmpv6.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <net/ipv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <net/netfilter/nf_log.h>
#include <net/netfilter/xt_log.h>
MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
MODULE_DESCRIPTION("Xtables: IPv6 packet logging to syslog");
MODULE_LICENSE("GPL");
struct in_device;
#include <net/route.h>
#include <linux/netfilter_ipv6/ip6t_LOG.h>
/* One level of recursion won't kill us */
static void dump_packet(struct sbuff *m,
const struct nf_loginfo *info,
const struct sk_buff *skb, unsigned int ip6hoff,
int recurse)
{
u_int8_t currenthdr;
int fragment;
struct ipv6hdr _ip6h;
const struct ipv6hdr *ih;
unsigned int ptr;
unsigned int hdrlen = 0;
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, ip6hoff, sizeof(_ip6h), &_ip6h);
if (ih == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
sb_add(m, "LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
(ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
ih->hop_limit,
(ntohl(*(__be32 *)ih) & 0x000fffff));
fragment = 0;
ptr = ip6hoff + sizeof(struct ipv6hdr);
currenthdr = ih->nexthdr;
while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
struct ipv6_opt_hdr _hdr;
const struct ipv6_opt_hdr *hp;
hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
if (hp == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 48 "OPT (...) " */
if (logflags & IP6T_LOG_IPOPT)
sb_add(m, "OPT ( ");
switch (currenthdr) {
case IPPROTO_FRAGMENT: {
struct frag_hdr _fhdr;
const struct frag_hdr *fh;
sb_add(m, "FRAG:");
fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
&_fhdr);
if (fh == NULL) {
sb_add(m, "TRUNCATED ");
return;
}
/* Max length: 6 "65535 " */
sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8);
/* Max length: 11 "INCOMPLETE " */
if (fh->frag_off & htons(0x0001))
sb_add(m, "INCOMPLETE ");
sb_add(m, "ID:%08x ", ntohl(fh->identification));
if (ntohs(fh->frag_off) & 0xFFF8)
fragment = 1;
hdrlen = 8;
break;
}
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
if (fragment) {
if (logflags & IP6T_LOG_IPOPT)
sb_add(m, ")");
return;
}
hdrlen = ipv6_optlen(hp);
break;
/* Max Length */
case IPPROTO_AH:
if (logflags & IP6T_LOG_IPOPT) {
struct ip_auth_hdr _ahdr;
const struct ip_auth_hdr *ah;
/* Max length: 3 "AH " */
sb_add(m, "AH ");
if (fragment) {
sb_add(m, ")");
return;
}
ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
&_ahdr);
if (ah == NULL) {
/*
* Max length: 26 "INCOMPLETE [65535
* bytes] )"
*/
sb_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 15 "SPI=0xF1234567 */
sb_add(m, "SPI=0x%x ", ntohl(ah->spi));
}
hdrlen = (hp->hdrlen+2)<<2;
break;
case IPPROTO_ESP:
if (logflags & IP6T_LOG_IPOPT) {
struct ip_esp_hdr _esph;
const struct ip_esp_hdr *eh;
/* Max length: 4 "ESP " */
sb_add(m, "ESP ");
if (fragment) {
sb_add(m, ")");
return;
}
/*
* Max length: 26 "INCOMPLETE [65535 bytes] )"
*/
eh = skb_header_pointer(skb, ptr, sizeof(_esph),
&_esph);
if (eh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 16 "SPI=0xF1234567 )" */
sb_add(m, "SPI=0x%x )", ntohl(eh->spi) );
}
return;
default:
/* Max length: 20 "Unknown Ext Hdr 255" */
sb_add(m, "Unknown Ext Hdr %u", currenthdr);
return;
}
if (logflags & IP6T_LOG_IPOPT)
sb_add(m, ") ");
currenthdr = hp->nexthdr;
ptr += hdrlen;
}
switch (currenthdr) {
case IPPROTO_TCP: {
struct tcphdr _tcph;
const struct tcphdr *th;
/* Max length: 10 "PROTO=TCP " */
sb_add(m, "PROTO=TCP ");
if (fragment)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph);
if (th == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr);
return;
}
/* Max length: 20 "SPT=65535 DPT=65535 " */
sb_add(m, "SPT=%u DPT=%u ",
ntohs(th->source), ntohs(th->dest));
/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
if (logflags & IP6T_LOG_TCPSEQ)
sb_add(m, "SEQ=%u ACK=%u ",
ntohl(th->seq), ntohl(th->ack_seq));
/* Max length: 13 "WINDOW=65535 " */
sb_add(m, "WINDOW=%u ", ntohs(th->window));
/* Max length: 9 "RES=0x3C " */
sb_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
if (th->cwr)
sb_add(m, "CWR ");
if (th->ece)
sb_add(m, "ECE ");
if (th->urg)
sb_add(m, "URG ");
if (th->ack)
sb_add(m, "ACK ");
if (th->psh)
sb_add(m, "PSH ");
if (th->rst)
sb_add(m, "RST ");
if (th->syn)
sb_add(m, "SYN ");
if (th->fin)
sb_add(m, "FIN ");
/* Max length: 11 "URGP=65535 " */
sb_add(m, "URGP=%u ", ntohs(th->urg_ptr));
if ((logflags & IP6T_LOG_TCPOPT) &&
th->doff * 4 > sizeof(struct tcphdr)) {
u_int8_t _opt[60 - sizeof(struct tcphdr)];
const u_int8_t *op;
unsigned int i;
unsigned int optsize = th->doff * 4
- sizeof(struct tcphdr);
op = skb_header_pointer(skb,
ptr + sizeof(struct tcphdr),
optsize, _opt);
if (op == NULL) {
sb_add(m, "OPT (TRUNCATED)");
return;
}
/* Max length: 127 "OPT (" 15*4*2chars ") " */
sb_add(m, "OPT (");
for (i =0; i < optsize; i++)
sb_add(m, "%02X", op[i]);
sb_add(m, ") ");
}
break;
}
case IPPROTO_UDP:
case IPPROTO_UDPLITE: {
struct udphdr _udph;
const struct udphdr *uh;
if (currenthdr == IPPROTO_UDP)
/* Max length: 10 "PROTO=UDP " */
sb_add(m, "PROTO=UDP " );
else /* Max length: 14 "PROTO=UDPLITE " */
sb_add(m, "PROTO=UDPLITE ");
if (fragment)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph);
if (uh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr);
return;
}
/* Max length: 20 "SPT=65535 DPT=65535 " */
sb_add(m, "SPT=%u DPT=%u LEN=%u ",
ntohs(uh->source), ntohs(uh->dest),
ntohs(uh->len));
break;
}
case IPPROTO_ICMPV6: {
struct icmp6hdr _icmp6h;
const struct icmp6hdr *ic;
/* Max length: 13 "PROTO=ICMPv6 " */
sb_add(m, "PROTO=ICMPv6 ");
if (fragment)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
if (ic == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr);
return;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
sb_add(m, "TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
switch (ic->icmp6_type) {
case ICMPV6_ECHO_REQUEST:
case ICMPV6_ECHO_REPLY:
/* Max length: 19 "ID=65535 SEQ=65535 " */
sb_add(m, "ID=%u SEQ=%u ",
ntohs(ic->icmp6_identifier),
ntohs(ic->icmp6_sequence));
break;
case ICMPV6_MGM_QUERY:
case ICMPV6_MGM_REPORT:
case ICMPV6_MGM_REDUCTION:
break;
case ICMPV6_PARAMPROB:
/* Max length: 17 "POINTER=ffffffff " */
sb_add(m, "POINTER=%08x ", ntohl(ic->icmp6_pointer));
/* Fall through */
case ICMPV6_DEST_UNREACH:
case ICMPV6_PKT_TOOBIG:
case ICMPV6_TIME_EXCEED:
/* Max length: 3+maxlen */
if (recurse) {
sb_add(m, "[");
dump_packet(m, info, skb,
ptr + sizeof(_icmp6h), 0);
sb_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu));
}
break;
}
/* Max length: 10 "PROTO=255 " */
default:
sb_add(m, "PROTO=%u ", currenthdr);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) {
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket && skb->sk->sk_socket->file)
sb_add(m, "UID=%u GID=%u ",
skb->sk->sk_socket->file->f_cred->fsuid,
skb->sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&skb->sk->sk_callback_lock);
}
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (!recurse && skb->mark)
sb_add(m, "MARK=0x%x ", skb->mark);
}
static void dump_mac_header(struct sbuff *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 & IP6T_LOG_MACDECODE))
goto fallback;
switch (dev->type) {
case ARPHRD_ETHER:
sb_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:
sb_add(m, "MAC=");
if (dev->hard_header_len &&
skb->mac_header != skb->network_header) {
const unsigned char *p = skb_mac_header(skb);
unsigned int len = dev->hard_header_len;
unsigned int i;
if (dev->type == ARPHRD_SIT &&
(p -= ETH_HLEN) < skb->head)
p = NULL;
if (p != NULL) {
sb_add(m, "%02x", *p++);
for (i = 1; i < len; i++)
sb_add(m, ":%02x", *p++);
}
sb_add(m, " ");
if (dev->type == ARPHRD_SIT) {
const struct iphdr *iph =
(struct iphdr *)skb_mac_header(skb);
sb_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr, &iph->daddr);
}
} else
sb_add(m, " ");
}
static struct nf_loginfo default_loginfo = {
.type = NF_LOG_TYPE_LOG,
.u = {
.log = {
.level = 5,
.logflags = NF_LOG_MASK,
},
},
};
static void
ip6t_log_packet(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 sbuff *m = sb_open();
if (!loginfo)
loginfo = &default_loginfo;
sb_add(m, "<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
prefix,
in ? in->name : "",
out ? out->name : "");
if (in != NULL)
dump_mac_header(m, loginfo, skb);
dump_packet(m, loginfo, skb, skb_network_offset(skb), 1);
sb_close(m);
}
static unsigned int
log_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct ip6t_log_info *loginfo = par->targinfo;
struct nf_loginfo li;
li.type = NF_LOG_TYPE_LOG;
li.u.log.level = loginfo->level;
li.u.log.logflags = loginfo->logflags;
ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, par->out,
&li, loginfo->prefix);
return XT_CONTINUE;
}
static int log_tg6_check(const struct xt_tgchk_param *par)
{
const struct ip6t_log_info *loginfo = par->targinfo;
if (loginfo->level >= 8) {
pr_debug("level %u >= 8\n", loginfo->level);
return -EINVAL;
}
if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
pr_debug("prefix not null-terminated\n");
return -EINVAL;
}
return 0;
}
static struct xt_target log_tg6_reg __read_mostly = {
.name = "LOG",
.family = NFPROTO_IPV6,
.target = log_tg6,
.targetsize = sizeof(struct ip6t_log_info),
.checkentry = log_tg6_check,
.me = THIS_MODULE,
};
static struct nf_logger ip6t_logger __read_mostly = {
.name = "ip6t_LOG",
.logfn = &ip6t_log_packet,
.me = THIS_MODULE,
};
static int __init log_tg6_init(void)
{
int ret;
ret = xt_register_target(&log_tg6_reg);
if (ret < 0)
return ret;
nf_log_register(NFPROTO_IPV6, &ip6t_logger);
return 0;
}
static void __exit log_tg6_exit(void)
{
nf_log_unregister(&ip6t_logger);
xt_unregister_target(&log_tg6_reg);
}
module_init(log_tg6_init);
module_exit(log_tg6_exit);

9
net/netfilter/Kconfig
View File

@ -524,6 +524,15 @@ config NETFILTER_XT_TARGET_LED
For more information on the LEDs available on your system, see
Documentation/leds/leds-class.txt
config NETFILTER_XT_TARGET_LOG
tristate "LOG target support"
default m if NETFILTER_ADVANCED=n
help
This option adds a `LOG' target, which allows you to create rules in
any iptables table which records the packet header to the syslog.
To compile it as a module, choose M here. If unsure, say N.
config NETFILTER_XT_TARGET_MARK
tristate '"MARK" target support'
depends on NETFILTER_ADVANCED

1
net/netfilter/Makefile
View File

@ -58,6 +58,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CT) += xt_CT.o
obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o
obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o
obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
obj-$(CONFIG_NETFILTER_XT_TARGET_LOG) += xt_LOG.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o

921
net/netfilter/xt_LOG.c Normal file
View File

@ -0,0 +1,921 @@
/*
* This is a module which is used for logging packets.
*/
/* (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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/x_tables.h>
#include <linux/netfilter/xt_LOG.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <net/netfilter/nf_log.h>
#include <net/netfilter/xt_log.h>
static struct nf_loginfo default_loginfo = {
.type = NF_LOG_TYPE_LOG,
.u = {
.log = {
.level = 5,
.logflags = NF_LOG_MASK,
},
},
};
static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb,
u8 proto, int fragment, unsigned int offset)
{
struct udphdr _udph;
const struct udphdr *uh;
if (proto == IPPROTO_UDP)
/* Max length: 10 "PROTO=UDP " */
sb_add(m, "PROTO=UDP ");
else /* Max length: 14 "PROTO=UDPLITE " */
sb_add(m, "PROTO=UDPLITE ");
if (fragment)
goto out;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
if (uh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset);
return 1;
}
/* Max length: 20 "SPT=65535 DPT=65535 " */
sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest),
ntohs(uh->len));
out:
return 0;
}
static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb,
u8 proto, int fragment, unsigned int offset,
unsigned int logflags)
{
struct tcphdr _tcph;
const struct tcphdr *th;
/* Max length: 10 "PROTO=TCP " */
sb_add(m, "PROTO=TCP ");
if (fragment)
return 0;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
if (th == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset);
return 1;
}
/* Max length: 20 "SPT=65535 DPT=65535 " */
sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest));
/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
if (logflags & XT_LOG_TCPSEQ)
sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq));
/* Max length: 13 "WINDOW=65535 " */
sb_add(m, "WINDOW=%u ", ntohs(th->window));
/* Max length: 9 "RES=0x3C " */
sb_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) &
TCP_RESERVED_BITS) >> 22));
/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
if (th->cwr)
sb_add(m, "CWR ");
if (th->ece)
sb_add(m, "ECE ");
if (th->urg)
sb_add(m, "URG ");
if (th->ack)
sb_add(m, "ACK ");
if (th->psh)
sb_add(m, "PSH ");
if (th->rst)
sb_add(m, "RST ");
if (th->syn)
sb_add(m, "SYN ");
if (th->fin)
sb_add(m, "FIN ");
/* Max length: 11 "URGP=65535 " */
sb_add(m, "URGP=%u ", ntohs(th->urg_ptr));
if ((logflags & XT_LOG_TCPOPT) && th->doff*4 > sizeof(struct tcphdr)) {
u_int8_t _opt[60 - sizeof(struct tcphdr)];
const u_int8_t *op;
unsigned int i;
unsigned int optsize = th->doff*4 - sizeof(struct tcphdr);
op = skb_header_pointer(skb, offset + sizeof(struct tcphdr),
optsize, _opt);
if (op == NULL) {
sb_add(m, "OPT (TRUNCATED)");
return 1;
}
/* Max length: 127 "OPT (" 15*4*2chars ") " */
sb_add(m, "OPT (");
for (i = 0; i < optsize; i++)
sb_add(m, "%02X", op[i]);
sb_add(m, ") ");
}
return 0;
}
/* One level of recursion won't kill us */
static void dump_ipv4_packet(struct sbuff *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) {
sb_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 " */
sb_add(m, "SRC=%pI4 DST=%pI4 ",
&ih->saddr, &ih->daddr);
/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
sb_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)
sb_add(m, "CE ");
if (ntohs(ih->frag_off) & IP_DF)
sb_add(m, "DF ");
if (ntohs(ih->frag_off) & IP_MF)
sb_add(m, "MF ");
/* Max length: 11 "FRAG:65535 " */
if (ntohs(ih->frag_off) & IP_OFFSET)
sb_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) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 127 "OPT (" 15*4*2chars ") " */
sb_add(m, "OPT (");
for (i = 0; i < optsize; i++)
sb_add(m, "%02X", op[i]);
sb_add(m, ") ");
}
switch (ih->protocol) {
case IPPROTO_TCP:
if (dump_tcp_header(m, skb, ih->protocol,
ntohs(ih->frag_off) & IP_OFFSET,
iphoff+ih->ihl*4, logflags))
return;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
if (dump_udp_header(m, skb, ih->protocol,
ntohs(ih->frag_off) & IP_OFFSET,
iphoff+ih->ihl*4))
return;
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 " */
sb_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) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
sb_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]) {
sb_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 " */
sb_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 " */
sb_add(m, "PARAMETER=%u ",
ntohl(ich->un.gateway) >> 24);
break;
case ICMP_REDIRECT:
/* Max length: 24 "GATEWAY=255.255.255.255 " */
sb_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. */
sb_add(m, "[");
dump_ipv4_packet(m, info, skb,
iphoff + ih->ihl*4+sizeof(_icmph));
sb_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ich->type == ICMP_DEST_UNREACH &&
ich->code == ICMP_FRAG_NEEDED)
sb_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 " */
sb_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) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
sb_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 " */
sb_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) {
sb_add(m, "INCOMPLETE [%u bytes] ",
skb->len - iphoff - ih->ihl*4);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
sb_add(m, "SPI=0x%x ", ntohl(eh->spi));
break;
}
/* Max length: 10 "PROTO 255 " */
default:
sb_add(m, "PROTO=%u ", ih->protocol);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & XT_LOG_UID) && !iphoff && skb->sk) {
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket && skb->sk->sk_socket->file)
sb_add(m, "UID=%u GID=%u ",
skb->sk->sk_socket->file->f_cred->fsuid,
skb->sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&skb->sk->sk_callback_lock);
}
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (!iphoff && skb->mark)
sb_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 sbuff *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:
sb_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:
sb_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;
sb_add(m, "%02x", *p++);
for (i = 1; i < dev->hard_header_len; i++, p++)
sb_add(m, ":%02x", *p);
}
sb_add(m, " ");
}
static void
log_packet_common(struct sbuff *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)
{
sb_add(m, "<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
prefix,
in ? in->name : "",
out ? out->name : "");
#ifdef CONFIG_BRIDGE_NETFILTER
if (skb->nf_bridge) {
const struct net_device *physindev;
const struct net_device *physoutdev;
physindev = skb->nf_bridge->physindev;
if (physindev && in != physindev)
sb_add(m, "PHYSIN=%s ", physindev->name);
physoutdev = skb->nf_bridge->physoutdev;
if (physoutdev && out != physoutdev)
sb_add(m, "PHYSOUT=%s ", physoutdev->name);
}
#endif
}
static void
ipt_log_packet(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 sbuff *m = sb_open();
if (!loginfo)
loginfo = &default_loginfo;
log_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);
sb_close(m);
}
#if IS_ENABLED(CONFIG_IPV6)
/* One level of recursion won't kill us */
static void dump_ipv6_packet(struct sbuff *m,
const struct nf_loginfo *info,
const struct sk_buff *skb, unsigned int ip6hoff,
int recurse)
{
u_int8_t currenthdr;
int fragment;
struct ipv6hdr _ip6h;
const struct ipv6hdr *ih;
unsigned int ptr;
unsigned int hdrlen = 0;
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, ip6hoff, sizeof(_ip6h), &_ip6h);
if (ih == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
sb_add(m, "LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
(ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
ih->hop_limit,
(ntohl(*(__be32 *)ih) & 0x000fffff));
fragment = 0;
ptr = ip6hoff + sizeof(struct ipv6hdr);
currenthdr = ih->nexthdr;
while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
struct ipv6_opt_hdr _hdr;
const struct ipv6_opt_hdr *hp;
hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
if (hp == NULL) {
sb_add(m, "TRUNCATED");
return;
}
/* Max length: 48 "OPT (...) " */
if (logflags & XT_LOG_IPOPT)
sb_add(m, "OPT ( ");
switch (currenthdr) {
case IPPROTO_FRAGMENT: {
struct frag_hdr _fhdr;
const struct frag_hdr *fh;
sb_add(m, "FRAG:");
fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
&_fhdr);
if (fh == NULL) {
sb_add(m, "TRUNCATED ");
return;
}
/* Max length: 6 "65535 " */
sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8);
/* Max length: 11 "INCOMPLETE " */
if (fh->frag_off & htons(0x0001))
sb_add(m, "INCOMPLETE ");
sb_add(m, "ID:%08x ", ntohl(fh->identification));
if (ntohs(fh->frag_off) & 0xFFF8)
fragment = 1;
hdrlen = 8;
break;
}
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
if (fragment) {
if (logflags & XT_LOG_IPOPT)
sb_add(m, ")");
return;
}
hdrlen = ipv6_optlen(hp);
break;
/* Max Length */
case IPPROTO_AH:
if (logflags & XT_LOG_IPOPT) {
struct ip_auth_hdr _ahdr;
const struct ip_auth_hdr *ah;
/* Max length: 3 "AH " */
sb_add(m, "AH ");
if (fragment) {
sb_add(m, ")");
return;
}
ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
&_ahdr);
if (ah == NULL) {
/*
* Max length: 26 "INCOMPLETE [65535
* bytes] )"
*/
sb_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 15 "SPI=0xF1234567 */
sb_add(m, "SPI=0x%x ", ntohl(ah->spi));
}
hdrlen = (hp->hdrlen+2)<<2;
break;
case IPPROTO_ESP:
if (logflags & XT_LOG_IPOPT) {
struct ip_esp_hdr _esph;
const struct ip_esp_hdr *eh;
/* Max length: 4 "ESP " */
sb_add(m, "ESP ");
if (fragment) {
sb_add(m, ")");
return;
}
/*
* Max length: 26 "INCOMPLETE [65535 bytes] )"
*/
eh = skb_header_pointer(skb, ptr, sizeof(_esph),
&_esph);
if (eh == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 16 "SPI=0xF1234567 )" */
sb_add(m, "SPI=0x%x )", ntohl(eh->spi));
}
return;
default:
/* Max length: 20 "Unknown Ext Hdr 255" */
sb_add(m, "Unknown Ext Hdr %u", currenthdr);
return;
}
if (logflags & XT_LOG_IPOPT)
sb_add(m, ") ");
currenthdr = hp->nexthdr;
ptr += hdrlen;
}
switch (currenthdr) {
case IPPROTO_TCP:
if (dump_tcp_header(m, skb, currenthdr, fragment, ptr,
logflags))
return;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
if (dump_udp_header(m, skb, currenthdr, fragment, ptr))
return;
case IPPROTO_ICMPV6: {
struct icmp6hdr _icmp6h;
const struct icmp6hdr *ic;
/* Max length: 13 "PROTO=ICMPv6 " */
sb_add(m, "PROTO=ICMPv6 ");
if (fragment)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
if (ic == NULL) {
sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr);
return;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
sb_add(m, "TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
switch (ic->icmp6_type) {
case ICMPV6_ECHO_REQUEST:
case ICMPV6_ECHO_REPLY:
/* Max length: 19 "ID=65535 SEQ=65535 " */
sb_add(m, "ID=%u SEQ=%u ",
ntohs(ic->icmp6_identifier),
ntohs(ic->icmp6_sequence));
break;
case ICMPV6_MGM_QUERY:
case ICMPV6_MGM_REPORT:
case ICMPV6_MGM_REDUCTION:
break;
case ICMPV6_PARAMPROB:
/* Max length: 17 "POINTER=ffffffff " */
sb_add(m, "POINTER=%08x ", ntohl(ic->icmp6_pointer));
/* Fall through */
case ICMPV6_DEST_UNREACH:
case ICMPV6_PKT_TOOBIG:
case ICMPV6_TIME_EXCEED:
/* Max length: 3+maxlen */
if (recurse) {
sb_add(m, "[");
dump_ipv6_packet(m, info, skb,
ptr + sizeof(_icmp6h), 0);
sb_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu));
}
break;
}
/* Max length: 10 "PROTO=255 " */
default:
sb_add(m, "PROTO=%u ", currenthdr);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & XT_LOG_UID) && recurse && skb->sk) {
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket && skb->sk->sk_socket->file)
sb_add(m, "UID=%u GID=%u ",
skb->sk->sk_socket->file->f_cred->fsuid,
skb->sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&skb->sk->sk_callback_lock);
}
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (!recurse && skb->mark)
sb_add(m, "MARK=0x%x ", skb->mark);
}
static void dump_ipv6_mac_header(struct sbuff *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:
sb_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:
sb_add(m, "MAC=");
if (dev->hard_header_len &&
skb->mac_header != skb->network_header) {
const unsigned char *p = skb_mac_header(skb);
unsigned int len = dev->hard_header_len;
unsigned int i;
if (dev->type == ARPHRD_SIT) {
p -= ETH_HLEN;
if (p < skb->head)
p = NULL;
}
if (p != NULL) {
sb_add(m, "%02x", *p++);
for (i = 1; i < len; i++)
sb_add(m, ":%02x", *p++);
}
sb_add(m, " ");
if (dev->type == ARPHRD_SIT) {
const struct iphdr *iph =
(struct iphdr *)skb_mac_header(skb);
sb_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr,
&iph->daddr);
}
} else
sb_add(m, " ");
}
static void
ip6t_log_packet(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 sbuff *m = sb_open();
if (!loginfo)
loginfo = &default_loginfo;
log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix);
if (in != NULL)
dump_ipv6_mac_header(m, loginfo, skb);
dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1);
sb_close(m);
}
#endif
static unsigned int
log_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_log_info *loginfo = par->targinfo;
struct nf_loginfo li;
li.type = NF_LOG_TYPE_LOG;
li.u.log.level = loginfo->level;
li.u.log.logflags = loginfo->logflags;
if (par->family == NFPROTO_IPV4)
ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in,
par->out, &li, loginfo->prefix);
#if IS_ENABLED(CONFIG_IPV6)
else if (par->family == NFPROTO_IPV6)
ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in,
par->out, &li, loginfo->prefix);
#endif
else
WARN_ON_ONCE(1);
return XT_CONTINUE;
}
static int log_tg_check(const struct xt_tgchk_param *par)
{
const struct xt_log_info *loginfo = par->targinfo;
if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6)
return -EINVAL;
if (loginfo->level >= 8) {
pr_debug("level %u >= 8\n", loginfo->level);
return -EINVAL;
}
if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
pr_debug("prefix is not null-terminated\n");
return -EINVAL;
}
return 0;
}
static struct xt_target log_tg_regs[] __read_mostly = {
{
.name = "LOG",
.family = NFPROTO_IPV4,
.target = log_tg,
.targetsize = sizeof(struct xt_log_info),
.checkentry = log_tg_check,
.me = THIS_MODULE,
},
#if IS_ENABLED(CONFIG_IPV6)
{
.name = "LOG",
.family = NFPROTO_IPV6,
.target = log_tg,
.targetsize = sizeof(struct xt_log_info),
.checkentry = log_tg_check,
.me = THIS_MODULE,
},
#endif
};
static struct nf_logger ipt_log_logger __read_mostly = {
.name = "ipt_LOG",
.logfn = &ipt_log_packet,
.me = THIS_MODULE,
};
#if IS_ENABLED(CONFIG_IPV6)
static struct nf_logger ip6t_log_logger __read_mostly = {
.name = "ip6t_LOG",
.logfn = &ip6t_log_packet,
.me = THIS_MODULE,
};
#endif
static int __init log_tg_init(void)
{
int ret;
ret = xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
if (ret < 0)
return ret;
nf_log_register(NFPROTO_IPV4, &ipt_log_logger);
#if IS_ENABLED(CONFIG_IPV6)
nf_log_register(NFPROTO_IPV6, &ip6t_log_logger);
#endif
return 0;
}
static void __exit log_tg_exit(void)
{
nf_log_unregister(&ipt_log_logger);
#if IS_ENABLED(CONFIG_IPV6)
nf_log_unregister(&ip6t_log_logger);
#endif
xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
}
module_init(log_tg_init);
module_exit(log_tg_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging");
MODULE_ALIAS("ipt_LOG");
MODULE_ALIAS("ip6t_LOG");