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Copy pathexpect-create-userspace.c
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163 lines (128 loc) · 4.24 KB
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/* Copyright (C) 2011 Wurldtech Security Technologies All rights reserved. */
/* Note - This code links to libnetfilter_conntrack, which is GPL. */
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <arpa/inet.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack_tcp.h>
static int verbose;
void ctprint(struct nf_conntrack* ct, const char* msg)
{
if(verbose) {
char buf[1024];
nfct_snprintf(buf, sizeof(buf), ct, 0, 0, 0);
printf("ct=%s -- %s\n", buf, msg);
}
}
void expprint(struct nf_expect *exp)
{
if(verbose) {
char buf[1024];
nfexp_snprintf(buf, sizeof(buf), exp, 0, 0, 0);
printf("exp=%s\n", buf);
}
}
void usage(void)
{
fprintf(stderr,
"usage: expect-create-userspace [-v ] -s srcip -d dstip -f srcport -t dstport -e expectport -T timeout [-P]\n"
);
exit(1);
}
int main(int argc, char* argv[])
{
const char* src = 0;
const char* dst = 0;
int sport = 0;
int dport = 0;
int expectport = 0;
int timeout = 0;
int flags = 0;
int opt;
while((opt = getopt(argc, argv, "s:d:f:t:e:T:Pv")) != -1) {
switch(opt) {
case 's': src = optarg; break;
case 'd': dst = optarg; break;
case 'f': sport = atoi(optarg); break;
case 't': dport = atoi(optarg); break;
case 'e': expectport = atoi(optarg); break;
case 'T': timeout = atoi(optarg); break;
case 'P': flags = NF_CT_EXPECT_PERMANENT; break;
case 'v': verbose = 1; break;
default:
usage();
break;
}
}
if(!(src && dst && sport && dport && expectport && timeout)) {
fprintf(stderr, "not all mandatory args were specified\n");
usage();
}
struct nf_conntrack* master = nfct_new();
if (!master) {
perror("nfct_new");
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(master, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(master, ATTR_IPV4_SRC, inet_addr(src));
nfct_set_attr_u32(master, ATTR_IPV4_DST, inet_addr(dst));
nfct_set_attr_u8(master, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(master, ATTR_PORT_SRC, htons(sport));
nfct_set_attr_u16(master, ATTR_PORT_DST, htons(dport));
ctprint(master, "master");
struct nf_conntrack* expected = nfct_new();
if (!expected) {
perror("nfct_new");
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(expected, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(expected, ATTR_IPV4_SRC, inet_addr(src));
nfct_set_attr_u32(expected, ATTR_IPV4_DST, inet_addr(dst));
nfct_set_attr_u8(expected, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(expected, ATTR_PORT_SRC, 0);
nfct_set_attr_u16(expected, ATTR_PORT_DST, htons(expectport));
ctprint(expected, "expected");
struct nf_conntrack* mask = nfct_new();
if (!mask) {
perror("nfct_new");
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(mask, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(mask, ATTR_IPV4_SRC, 0xffffffff);
nfct_set_attr_u32(mask, ATTR_IPV4_DST, 0xffffffff);
nfct_set_attr_u8(mask, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(mask, ATTR_PORT_SRC, 0x0000);
nfct_set_attr_u16(mask, ATTR_PORT_DST, 0xffff);
ctprint(mask, "mask");
struct nf_expect* exp = nfexp_new();
if (!exp) {
perror("nfexp_new");
exit(EXIT_FAILURE);
}
nfexp_set_attr(exp, ATTR_EXP_MASTER, master);
nfexp_set_attr(exp, ATTR_EXP_EXPECTED, expected);
nfexp_set_attr(exp, ATTR_EXP_MASK, mask);
nfexp_set_attr_u32(exp, ATTR_EXP_TIMEOUT, timeout);
nfexp_set_attr_u32(exp, ATTR_EXP_FLAGS, flags);
nfct_destroy(master);
nfct_destroy(expected);
nfct_destroy(mask);
expprint(exp);
struct nfct_handle* h = nfct_open(EXPECT, 0);
if (!h) {
perror("nfct_open");
exit(EXIT_FAILURE);
}
if (nfexp_query(h, NFCT_Q_CREATE_UPDATE, exp) < 0) {
perror("nfexp_query");
exit(EXIT_FAILURE);
} else {
printf("Expecting traffic on TCP port %d on %s from %s\n",
expectport, dst, src);
}
nfct_close(h);
return 0;
}