175 lines
4.0 KiB
C
175 lines
4.0 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Mini nslookup implementation for busybox
|
|
*
|
|
* Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
|
|
* Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.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.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include <ctype.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
|
|
#include <netdb.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/types.h>
|
|
#include <netinet/in.h>
|
|
#include <resolv.h>
|
|
#include <arpa/inet.h>
|
|
#include "busybox.h"
|
|
|
|
/*
|
|
| I'm only implementing non-interactive mode;
|
|
| I totally forgot nslookup even had an interactive mode.
|
|
|
|
|
| [ TODO ]
|
|
| + find out how to use non-default name servers
|
|
*/
|
|
|
|
/* only works for IPv4 */
|
|
static int addr_fprint(char *addr)
|
|
{
|
|
u_int8_t split[4];
|
|
u_int32_t ip;
|
|
u_int32_t *x = (u_int32_t *) addr;
|
|
|
|
ip = ntohl(*x);
|
|
split[0] = (ip & 0xff000000) >> 24;
|
|
split[1] = (ip & 0x00ff0000) >> 16;
|
|
split[2] = (ip & 0x0000ff00) >> 8;
|
|
split[3] = (ip & 0x000000ff);
|
|
printf("%d.%d.%d.%d", split[0], split[1], split[2], split[3]);
|
|
return 0;
|
|
}
|
|
|
|
/* takes the NULL-terminated array h_addr_list, and
|
|
* prints its contents appropriately
|
|
*/
|
|
static int addr_list_fprint(char **h_addr_list)
|
|
{
|
|
int i, j;
|
|
char *addr_string = (h_addr_list[1])
|
|
? "Addresses: " : "Address: ";
|
|
|
|
printf("%s ", addr_string);
|
|
for (i = 0, j = 0; h_addr_list[i]; i++, j++) {
|
|
addr_fprint(h_addr_list[i]);
|
|
|
|
/* real nslookup does this */
|
|
if (j == 4) {
|
|
if (h_addr_list[i + 1]) {
|
|
printf("\n ");
|
|
}
|
|
j = 0;
|
|
} else {
|
|
if (h_addr_list[i + 1]) {
|
|
printf(", ");
|
|
}
|
|
}
|
|
|
|
}
|
|
printf("\n");
|
|
return 0;
|
|
}
|
|
|
|
/* print the results as nslookup would */
|
|
static struct hostent *hostent_fprint(struct hostent *host, const char *server_host)
|
|
{
|
|
if (host) {
|
|
printf("%s %s\n", server_host, host->h_name);
|
|
addr_list_fprint(host->h_addr_list);
|
|
} else {
|
|
printf("*** Unknown host\n");
|
|
}
|
|
return host;
|
|
}
|
|
|
|
/* changes a c-string matching the perl regex \d+\.\d+\.\d+\.\d+
|
|
* into a u_int32_t
|
|
*/
|
|
static u_int32_t str_to_addr(const char *addr)
|
|
{
|
|
u_int32_t split[4];
|
|
u_int32_t ip;
|
|
|
|
sscanf(addr, "%d.%d.%d.%d",
|
|
&split[0], &split[1], &split[2], &split[3]);
|
|
|
|
/* assuming sscanf worked */
|
|
ip = (split[0] << 24) |
|
|
(split[1] << 16) | (split[2] << 8) | (split[3]);
|
|
|
|
return htonl(ip);
|
|
}
|
|
|
|
/* gethostbyaddr wrapper */
|
|
static struct hostent *gethostbyaddr_wrapper(const char *address)
|
|
{
|
|
struct in_addr addr;
|
|
|
|
addr.s_addr = str_to_addr(address);
|
|
return gethostbyaddr((char *) &addr, 4, AF_INET); /* IPv4 only for now */
|
|
}
|
|
|
|
/* lookup the default nameserver and display it */
|
|
static inline void server_print(void)
|
|
{
|
|
struct sockaddr_in def = _res.nsaddr_list[0];
|
|
char *ip = inet_ntoa(def.sin_addr);
|
|
|
|
hostent_fprint(gethostbyaddr_wrapper(ip), "Server:");
|
|
printf("\n");
|
|
}
|
|
|
|
/* naive function to check whether char *s is an ip address */
|
|
static int is_ip_address(const char *s)
|
|
{
|
|
while (*s) {
|
|
if ((isdigit(*s)) || (*s == '.')) {
|
|
s++;
|
|
continue;
|
|
}
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* ________________________________________________________________________ */
|
|
int nslookup_main(int argc, char **argv)
|
|
{
|
|
struct hostent *host;
|
|
|
|
if (argc < 2 || *argv[1]=='-') {
|
|
show_usage();
|
|
}
|
|
|
|
res_init();
|
|
server_print();
|
|
if (is_ip_address(argv[1])) {
|
|
host = gethostbyaddr_wrapper(argv[1]);
|
|
} else {
|
|
host = xgethostbyname(argv[1]);
|
|
}
|
|
hostent_fprint(host, "Name: ");
|
|
return EXIT_SUCCESS;
|
|
}
|
|
|
|
/* $Id: nslookup.c,v 1.28 2002/04/27 04:06:55 andersen Exp $ */
|