A patch from Benjamin Zeckel <bzeckel@cisco.com> to allow

nslookup.c to display the correct default nameservers.
This commit is contained in:
Eric Andersen 2001-06-12 22:21:24 +00:00
parent 583e3ca456
commit dab3d46b9d
2 changed files with 80 additions and 78 deletions

View File

@ -31,6 +31,8 @@
#include <sys/socket.h> #include <sys/socket.h>
#include <sys/types.h> #include <sys/types.h>
#include <netinet/in.h> #include <netinet/in.h>
#include <resolv.h>
#include <arpa/inet.h>
#include "busybox.h" #include "busybox.h"
/* /*
@ -39,19 +41,8 @@
| |
| [ TODO ] | [ TODO ]
| + find out how to use non-default name servers | + find out how to use non-default name servers
| + find out how the real nslookup gets the default name server
*/ */
/* I have to see how the real nslookup does this.
* I could dig through /etc/resolv.conf, but is there a
* better (programatic) way?
*/
static inline void server_print(void)
{
printf("Server: %s\n", "default");
printf("Address: %s\n\n", "default");
}
/* only works for IPv4 */ /* only works for IPv4 */
static int addr_fprint(char *addr) static int addr_fprint(char *addr)
{ {
@ -68,24 +59,6 @@ static int addr_fprint(char *addr)
return 0; return 0;
} }
/* 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);
}
/* takes the NULL-terminated array h_addr_list, and /* takes the NULL-terminated array h_addr_list, and
* prints its contents appropriately * prints its contents appropriately
*/ */
@ -116,15 +89,6 @@ static int addr_list_fprint(char **h_addr_list)
return 0; return 0;
} }
/* 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 */
}
/* print the results as nslookup would */ /* print the results as nslookup would */
static struct hostent *hostent_fprint(struct hostent *host) static struct hostent *hostent_fprint(struct hostent *host)
{ {
@ -137,6 +101,42 @@ static struct hostent *hostent_fprint(struct hostent *host)
return host; 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));
printf("\n");
}
/* naive function to check whether char *s is an ip address */ /* naive function to check whether char *s is an ip address */
static int is_ip_address(const char *s) static int is_ip_address(const char *s)
@ -160,6 +160,7 @@ int nslookup_main(int argc, char **argv)
show_usage(); show_usage();
} }
res_init();
server_print(); server_print();
if (is_ip_address(argv[1])) { if (is_ip_address(argv[1])) {
host = gethostbyaddr_wrapper(argv[1]); host = gethostbyaddr_wrapper(argv[1]);
@ -170,4 +171,4 @@ int nslookup_main(int argc, char **argv)
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }
/* $Id: nslookup.c,v 1.22 2001/02/20 06:14:08 andersen Exp $ */ /* $Id: nslookup.c,v 1.23 2001/06/12 22:21:24 andersen Exp $ */

View File

@ -31,6 +31,8 @@
#include <sys/socket.h> #include <sys/socket.h>
#include <sys/types.h> #include <sys/types.h>
#include <netinet/in.h> #include <netinet/in.h>
#include <resolv.h>
#include <arpa/inet.h>
#include "busybox.h" #include "busybox.h"
/* /*
@ -39,19 +41,8 @@
| |
| [ TODO ] | [ TODO ]
| + find out how to use non-default name servers | + find out how to use non-default name servers
| + find out how the real nslookup gets the default name server
*/ */
/* I have to see how the real nslookup does this.
* I could dig through /etc/resolv.conf, but is there a
* better (programatic) way?
*/
static inline void server_print(void)
{
printf("Server: %s\n", "default");
printf("Address: %s\n\n", "default");
}
/* only works for IPv4 */ /* only works for IPv4 */
static int addr_fprint(char *addr) static int addr_fprint(char *addr)
{ {
@ -68,24 +59,6 @@ static int addr_fprint(char *addr)
return 0; return 0;
} }
/* 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);
}
/* takes the NULL-terminated array h_addr_list, and /* takes the NULL-terminated array h_addr_list, and
* prints its contents appropriately * prints its contents appropriately
*/ */
@ -116,15 +89,6 @@ static int addr_list_fprint(char **h_addr_list)
return 0; return 0;
} }
/* 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 */
}
/* print the results as nslookup would */ /* print the results as nslookup would */
static struct hostent *hostent_fprint(struct hostent *host) static struct hostent *hostent_fprint(struct hostent *host)
{ {
@ -137,6 +101,42 @@ static struct hostent *hostent_fprint(struct hostent *host)
return host; 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));
printf("\n");
}
/* naive function to check whether char *s is an ip address */ /* naive function to check whether char *s is an ip address */
static int is_ip_address(const char *s) static int is_ip_address(const char *s)
@ -160,6 +160,7 @@ int nslookup_main(int argc, char **argv)
show_usage(); show_usage();
} }
res_init();
server_print(); server_print();
if (is_ip_address(argv[1])) { if (is_ip_address(argv[1])) {
host = gethostbyaddr_wrapper(argv[1]); host = gethostbyaddr_wrapper(argv[1]);
@ -170,4 +171,4 @@ int nslookup_main(int argc, char **argv)
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }
/* $Id: nslookup.c,v 1.22 2001/02/20 06:14:08 andersen Exp $ */ /* $Id: nslookup.c,v 1.23 2001/06/12 22:21:24 andersen Exp $ */