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/*
* (C) 2005-2007 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 <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack_tcp.h>
#include "conntrack.h"
static struct option opts[] = {
{"orig-port-src", 1, 0, '1'},
{"sport", 1, 0, '1'},
{"orig-port-dst", 1, 0, '2'},
{"dport", 1, 0, '2'},
{"reply-port-src", 1, 0, '3'},
{"reply-port-dst", 1, 0, '4'},
{"mask-port-src", 1, 0, '5'},
{"mask-port-dst", 1, 0, '6'},
{"state", 1, 0, '7'},
{"tuple-port-src", 1, 0, '8'},
{"tuple-port-dst", 1, 0, '9'},
{0, 0, 0, 0}
};
#define TCP_NUMBER_OF_OPT 10
static const char *tcp_optflags[TCP_NUMBER_OF_OPT] = {
"sport", "dport", "reply-port-src", "reply-port-dst", "mask-port-src",
"mask-port-dst", "state", "tuple-port-src", "tuple-port-dst"
};
static char tcp_commands_v_options[NUMBER_OF_CMD][TCP_NUMBER_OF_OPT] =
/* Well, it's better than "Re: Sevilla vs Betis" */
{
/* 1 2 3 4 5 6 7 8 9 */
/*CT_LIST*/ {2,2,2,2,0,0,2,0,0},
/*CT_CREATE*/ {1,1,1,1,0,0,1,0,0},
/*CT_UPDATE*/ {1,1,1,1,0,0,2,0,0},
/*CT_DELETE*/ {1,1,1,1,0,0,0,0,0},
/*CT_GET*/ {1,1,1,1,0,0,2,0,0},
/*CT_FLUSH*/ {0,0,0,0,0,0,0,0,0},
/*CT_EVENT*/ {2,2,2,2,0,0,2,0,0},
/*CT_VERSION*/ {0,0,0,0,0,0,0,0,0},
/*CT_HELP*/ {0,0,0,0,0,0,0,0,0},
/*EXP_LIST*/ {0,0,0,0,0,0,0,0,0},
/*EXP_CREATE*/ {1,1,1,1,1,1,0,1,1},
/*EXP_DELETE*/ {1,1,1,1,0,0,0,0,0},
/*EXP_GET*/ {1,1,1,1,0,0,0,0,0},
/*EXP_FLUSH*/ {0,0,0,0,0,0,0,0,0},
/*EXP_EVENT*/ {0,0,0,0,0,0,0,0,0},
};
static const char *states[] = {
"NONE",
"SYN_SENT",
"SYN_RECV",
"ESTABLISHED",
"FIN_WAIT",
"CLOSE_WAIT",
"LAST_ACK",
"TIME_WAIT",
"CLOSE",
"LISTEN"
};
static void help()
{
fprintf(stdout, " --orig-port-src\t\toriginal source port\n");
fprintf(stdout, " --orig-port-dst\t\toriginal destination port\n");
fprintf(stdout, " --reply-port-src\t\treply source port\n");
fprintf(stdout, " --reply-port-dst\t\treply destination port\n");
fprintf(stdout, " --mask-port-src\t\tmask source port\n");
fprintf(stdout, " --mask-port-dst\t\tmask destination port\n");
fprintf(stdout, " --tuple-port-src\t\texpectation tuple src port\n");
fprintf(stdout, " --tuple-port-src\t\texpectation tuple dst port\n");
fprintf(stdout, " --state\t\t\tTCP state, fe. ESTABLISHED\n");
}
static int parse_options(char c,
struct nf_conntrack *ct,
struct nf_conntrack *exptuple,
struct nf_conntrack *mask,
unsigned int *flags)
{
int i;
switch(c) {
case '1':
if (!optarg)
break;
nfct_set_attr_u16(ct,
ATTR_ORIG_PORT_SRC,
htons(atoi(optarg)));
*flags |= TCP_ORIG_SPORT;
break;
case '2':
if (!optarg)
break;
nfct_set_attr_u16(ct,
ATTR_ORIG_PORT_DST,
htons(atoi(optarg)));
*flags |= TCP_ORIG_DPORT;
break;
case '3':
if (!optarg)
break;
nfct_set_attr_u16(ct,
ATTR_REPL_PORT_SRC,
htons(atoi(optarg)));
*flags |= TCP_REPL_SPORT;
break;
case '4':
if (!optarg)
break;
nfct_set_attr_u16(ct,
ATTR_REPL_PORT_DST,
htons(atoi(optarg)));
*flags |= TCP_REPL_DPORT;
break;
case '5':
if (!optarg)
break;
nfct_set_attr_u16(mask,
ATTR_ORIG_PORT_SRC,
htons(atoi(optarg)));
*flags |= TCP_MASK_SPORT;
break;
case '6':
if (!optarg)
break;
nfct_set_attr_u16(mask,
ATTR_ORIG_PORT_DST,
htons(atoi(optarg)));
*flags |= TCP_MASK_DPORT;
break;
case '7':
if (!optarg)
break;
for (i=0; i<10; i++) {
if (strcmp(optarg, states[i]) == 0) {
nfct_set_attr_u8(ct,
ATTR_TCP_STATE,
i);
break;
}
}
if (i == 10)
exit_error(PARAMETER_PROBLEM,
"Unknown TCP state %s\n", optarg);
*flags |= TCP_STATE;
break;
case '8':
if (!optarg)
break;
nfct_set_attr_u16(exptuple,
ATTR_ORIG_PORT_SRC,
htons(atoi(optarg)));
*flags |= TCP_EXPTUPLE_SPORT;
break;
case '9':
if (!optarg)
break;
nfct_set_attr_u16(exptuple,
ATTR_ORIG_PORT_DST,
htons(atoi(optarg)));
*flags |= TCP_EXPTUPLE_DPORT;
break;
}
return 1;
}
static void final_check(unsigned int flags,
unsigned int cmd,
struct nf_conntrack *ct)
{
if ((flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT))
&& !(flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))) {
nfct_set_attr_u16(ct,
ATTR_REPL_PORT_SRC,
nfct_get_attr_u16(ct, ATTR_ORIG_PORT_DST));
nfct_set_attr_u16(ct,
ATTR_REPL_PORT_DST,
nfct_get_attr_u16(ct, ATTR_ORIG_PORT_SRC));
flags |= TCP_REPL_SPORT;
flags |= TCP_REPL_DPORT;
} else if (!(flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT))
&& (flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))) {
nfct_set_attr_u16(ct,
ATTR_ORIG_PORT_SRC,
nfct_get_attr_u16(ct, ATTR_REPL_PORT_DST));
nfct_set_attr_u16(ct,
ATTR_ORIG_PORT_DST,
nfct_get_attr_u16(ct, ATTR_REPL_PORT_SRC));
flags |= TCP_ORIG_SPORT;
flags |= TCP_ORIG_DPORT;
}
generic_opt_check(flags,
TCP_NUMBER_OF_OPT,
tcp_commands_v_options[cmd],
tcp_optflags);
}
static struct ctproto_handler tcp = {
.name = "tcp",
.protonum = IPPROTO_TCP,
.parse_opts = parse_options,
.final_check = final_check,
.help = help,
.opts = opts,
.version = VERSION,
};
void register_tcp(void)
{
register_proto(&tcp);
}
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