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-rw-r--r--networking/nslookup.c42
1 files changed, 35 insertions, 7 deletions
diff --git a/networking/nslookup.c b/networking/nslookup.c
index 02d1846..edbc656 100644
--- a/networking/nslookup.c
+++ b/networking/nslookup.c
@@ -5,6 +5,9 @@
* Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
* Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
*
+ * Correct default name server display and explicit name server option
+ * added by Ben Zeckel <bzeckel@hmc.edu> June 2001
+ *
* 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
@@ -38,9 +41,6 @@
/*
| 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 */
@@ -138,6 +138,19 @@ static inline void server_print(void)
printf("\n");
}
+/* alter the global _res nameserver structure to use
+ an explicit dns server instead of what is in /etc/resolv.h */
+static inline void set_default_dns(char *server)
+{
+ struct in_addr server_in_addr;
+
+ if(inet_aton(server,&server_in_addr))
+ {
+ _res.nscount = 1;
+ _res.nsaddr_list[0].sin_addr = server_in_addr;
+ }
+}
+
/* naive function to check whether char *s is an ip address */
static int is_ip_address(const char *s)
{
@@ -156,11 +169,26 @@ int nslookup_main(int argc, char **argv)
{
struct hostent *host;
- if (argc < 2 || *argv[1]=='-') {
+ /*
+ * initialize DNS structure _res used in printing the default
+ * name server and in the explicit name server option feature.
+ */
+
+ res_init();
+
+ /*
+ * We allow 1 or 2 arguments.
+ * The first is the name to be looked up and the second is an
+ * optional DNS server with which to do the lookup.
+ * More than 3 arguments is an error to follow the pattern of the
+ * standard nslookup
+ */
+
+ if (argc < 2 || *argv[1]=='-' || argc > 3)
show_usage();
- }
+ else if(argc == 3)
+ set_default_dns(argv[2]);
- res_init();
server_print();
if (is_ip_address(argv[1])) {
host = gethostbyaddr_wrapper(argv[1]);
@@ -171,4 +199,4 @@ int nslookup_main(int argc, char **argv)
return EXIT_SUCCESS;
}
-/* $Id: nslookup.c,v 1.28 2002/04/27 04:06:55 andersen Exp $ */
+/* $Id: nslookup.c,v 1.29 2002/07/24 00:56:56 sandman Exp $ */