Added support for choosing ip to listen on for DNS

This commit is contained in:
Erik Ekman 2006-08-11 22:52:36 +00:00
parent fdb56f8e97
commit 4c0032c04c
4 changed files with 20 additions and 9 deletions

6
dns.c
View file

@ -58,7 +58,7 @@ uint16_t pingid;
int
open_dns(const char *domain, int localport)
open_dns(const char *domain, int localport, in_addr_t listen_ip)
{
int fd;
int flag;
@ -67,9 +67,9 @@ open_dns(const char *domain, int localport)
bzero(&addr, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(localport);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_addr.s_addr = listen_ip; // This is already network byte order, inet_addr() or constant INADDR_ANY (==0)
fd = socket(AF_INET, SOCK_DGRAM, 0);
fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if(fd < 0) {
warn("socket");
return -1;

2
dns.h
View file

@ -17,7 +17,7 @@
#ifndef _DNS_H_
#define _DNS_H_
int open_dns(const char *, int);
int open_dns(const char *, int, in_addr_t);
int dns_settarget(const char*);
void close_dns(int);

View file

@ -255,7 +255,7 @@ main(int argc, char **argv)
if ((tun_fd = open_tun(device)) == -1)
goto cleanup1;
if ((dns_fd = open_dns(argv[1], 0)) == -1)
if ((dns_fd = open_dns(argv[1], 0, INADDR_ANY)) == -1)
goto cleanup2;
if (dns_settarget(argv[0]) == -1)
goto cleanup2;

View file

@ -163,7 +163,7 @@ extern char *__progname;
static void
usage() {
printf("Usage: %s [-v] [-h] [-f] [-u user] [-t chrootdir] [-d device] [-m mtu] "
printf("Usage: %s [-v] [-h] [-f] [-u user] [-t chrootdir] [-d device] [-m mtu] [-l ip address to listen on] "
"tunnel_ip topdomain\n", __progname);
exit(2);
}
@ -171,7 +171,7 @@ usage() {
static void
help() {
printf("iodine IP over DNS tunneling server\n");
printf("Usage: %s [-v] [-h] [-f] [-u user] [-t chrootdir] [-d device] [-m mtu] "
printf("Usage: %s [-v] [-h] [-f] [-u user] [-t chrootdir] [-d device] [-m mtu] [-l ip address to listen on] "
"tunnel_ip topdomain\n", __progname);
printf(" -v to print version info and exit\n");
printf(" -h to print this help and exit\n");
@ -180,6 +180,7 @@ help() {
printf(" -t dir to chroot to directory dir\n");
printf(" -d device to set tunnel device name\n");
printf(" -m mtu to set tunnel device mtu\n");
printf(" -l ip address to listen on for incoming dns traffic (default 0.0.0.0)\n");
printf("tunnel_ip is the IP number of the local tunnel interface.\n");
printf("topdomain is the FQDN that is delegated to this server.\n");
exit(0);
@ -205,19 +206,21 @@ main(int argc, char **argv)
int foreground;
int mtu;
struct passwd *pw;
in_addr_t listen_ip;
username = NULL;
newroot = NULL;
device = NULL;
foreground = 0;
mtu = 1024;
listen_ip = INADDR_ANY;
packetbuf.len = 0;
packetbuf.offset = 0;
outpacket.len = 0;
q.id = 0;
while ((choice = getopt(argc, argv, "vfhu:t:d:m:")) != -1) {
while ((choice = getopt(argc, argv, "vfhu:t:d:m:l:")) != -1) {
switch(choice) {
case 'v':
version();
@ -240,6 +243,9 @@ main(int argc, char **argv)
case 'm':
mtu = atoi(optarg);
break;
case 'l':
listen_ip = inet_addr(optarg);
break;
default:
usage();
break;
@ -270,11 +276,16 @@ main(int argc, char **argv)
usage();
}
if (listen_ip == INADDR_NONE) {
printf("Bad IP address to listen on.\n");
usage();
}
if ((tun_fd = open_tun(device)) == -1)
goto cleanup0;
if (tun_setip(argv[0]) != 0 || tun_setmtu(mtu) != 0)
goto cleanup1;
if ((dnsd_fd = open_dns(argv[1], 53)) == -1)
if ((dnsd_fd = open_dns(argv[1], 53, listen_ip)) == -1)
goto cleanup2;
my_ip = inet_addr(argv[0]);