diff options
| -rw-r--r-- | networking/nslookup.c | 42 |
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 $ */ |