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/*
* (C) 2005 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <stdio.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h> /* For htons */
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack_extensions.h>
static const char *states[] = {
"NONE",
"SYN_SENT",
"SYN_RECV",
"ESTABLISHED",
"FIN_WAIT",
"CLOSE_WAIT",
"LAST_ACK",
"TIME_WAIT",
"CLOSE",
"LISTEN"
};
static void parse_proto(struct nfattr *cda[], struct nfct_tuple *tuple)
{
if (cda[CTA_PROTO_SRC_PORT-1])
tuple->l4src.tcp.port =
*(u_int16_t *)NFA_DATA(cda[CTA_PROTO_SRC_PORT-1]);
if (cda[CTA_PROTO_DST_PORT-1])
tuple->l4dst.tcp.port =
*(u_int16_t *)NFA_DATA(cda[CTA_PROTO_DST_PORT-1]);
}
static void parse_protoinfo(struct nfattr *cda[], struct nfct_conntrack *ct)
{
struct nfattr *tb[CTA_PROTOINFO_TCP_MAX];
/*
* Listen to me carefully: This is easy to trigger with events ;).
* The conntrack event messages don't always contain all the
* information about a conntrack, just those fields that have changed.
* So you can receive a message about a TCP connection with no bits
* talking about the private protocol information.
*
* --pablo 05/10/31
*/
if (!cda[CTA_PROTOINFO_TCP-1])
return;
nfnl_parse_nested(tb,CTA_PROTOINFO_TCP_MAX, cda[CTA_PROTOINFO_TCP-1]);
if (tb[CTA_PROTOINFO_TCP_STATE-1])
ct->protoinfo.tcp.state =
*(u_int8_t *)NFA_DATA(tb[CTA_PROTOINFO_TCP_STATE-1]);
}
static void build_tuple_proto(struct nfnlhdr *req, int size,
struct nfct_tuple *t)
{
nfnl_addattr_l(&req->nlh, size, CTA_PROTO_SRC_PORT,
&t->l4src.tcp.port, sizeof(u_int16_t));
nfnl_addattr_l(&req->nlh, size, CTA_PROTO_DST_PORT,
&t->l4dst.tcp.port, sizeof(u_int16_t));
}
static void build_protoinfo(struct nfnlhdr *req, int size,
struct nfct_conntrack *ct)
{
struct nfattr *nest_proto;
nest_proto = nfnl_nest(&req->nlh, size, CTA_PROTOINFO_TCP);
nfnl_addattr_l(&req->nlh, size, CTA_PROTOINFO_TCP_STATE,
&ct->protoinfo.tcp.state, sizeof(u_int8_t));
nfnl_nest_end(&req->nlh, nest_proto);
}
static int print_protoinfo(char *buf, union nfct_protoinfo *protoinfo)
{
return(sprintf(buf, "%s ", states[protoinfo->tcp.state]));
}
static int print_proto(char *buf, struct nfct_tuple *tuple)
{
return(sprintf(buf, "sport=%u dport=%u ", htons(tuple->l4src.tcp.port),
htons(tuple->l4dst.tcp.port)));
}
static struct nfct_proto tcp = {
.name = "tcp",
.protonum = IPPROTO_TCP,
.parse_protoinfo = parse_protoinfo,
.parse_proto = parse_proto,
.build_tuple_proto = build_tuple_proto,
.build_protoinfo = build_protoinfo,
.print_protoinfo = print_protoinfo,
.print_proto = print_proto,
.version = LIBNETFILTER_CONNTRACK_VERSION
};
static void __attribute__ ((constructor)) init(void);
static void init(void)
{
nfct_register_proto(&tcp);
}
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