rdate: make it do something remotely sane, facing 32-bit time overflow

[oweals/busybox.git] / networking / nslookup.c

diff --git a/networking/nslookup.c b/networking/nslookup.c
index 67fc01547c67d71aeef5c3b01f8b8edc9ca24d2d..8e3c8fed9af02f79755c789001c2d285ef9a0f0f 100644 (file)
--- a/networking/nslookup.c
+++ b/networking/nslookup.c
@@ -10,6 +10,29 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
+//config:config NSLOOKUP
+//config:      bool "nslookup"
+//config:      default y
+//config:      help
+//config:        nslookup is a tool to query Internet name servers.
+
+//applet:IF_NSLOOKUP(APPLET(nslookup, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_NSLOOKUP) += nslookup.o
+
+//usage:#define nslookup_trivial_usage
+//usage:       "[HOST] [SERVER]"
+//usage:#define nslookup_full_usage "\n\n"
+//usage:       "Query the nameserver for the IP address of the given HOST\n"
+//usage:       "optionally using a specified DNS server"
+//usage:
+//usage:#define nslookup_example_usage
+//usage:       "$ nslookup localhost\n"
+//usage:       "Server:     default\n"
+//usage:       "Address:    default\n"
+//usage:       "\n"
+//usage:       "Name:       debian\n"
+//usage:       "Address:    127.0.0.1\n"
 
 #include <resolv.h>
 #include "libbb.h"
@@ -124,6 +147,9 @@ static void set_default_dns(const char *server)
 {
        len_and_sockaddr *lsa;
 
+       if (!server)
+               return;
+
        /* NB: this works even with, say, "[::1]:5353"! :) */
        lsa = xhost2sockaddr(server, 53);
 
@@ -167,9 +193,17 @@ int nslookup_main(int argc, char **argv)
        /* (but it also says "may be enabled in /etc/resolv.conf") */
        /*_res.options |= RES_USE_INET6;*/
 
-       if (argv[2])
-               set_default_dns(argv[2]);
+       set_default_dns(argv[2]);
 
        server_print();
+
+       /* getaddrinfo and friends are free to request a resolver
+        * reinitialization. Just in case, set_default_dns() again
+        * after getaddrinfo (in server_print). This reportedly helps
+        * with bug 675 "nslookup does not properly use second argument"
+        * at least on Debian Wheezy and Openwrt AA (eglibc based).
+        */
+       set_default_dns(argv[2]);
+
        return print_host(argv[1], "Name:");
 }