X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fnslookup.c;h=f4fd407dd7922c515950cdf2ccdf9c7296668308;hb=3f21044f20ef304309651bbdef8b275475f03a28;hp=8a820ce37cb4329cbd042d7f43c9db37a7a7ad72;hpb=3f5f24646656b761d2d50e57d778f41b13bffa11;p=oweals%2Fbusybox.git

diff --git a/networking/nslookup.c b/networking/nslookup.c
index 8a820ce37..f4fd407dd 100644
--- a/networking/nslookup.c
+++ b/networking/nslookup.c
@@ -8,9 +8,23 @@
  * Correct default name server display and explicit name server option
  * added by Ben Zeckel <bzeckel@hmc.edu> June 2001
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
+//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"
 
@@ -66,7 +80,7 @@ static int print_host(const char *hostname, const char *header)
 	// hint.ai_flags = AI_CANONNAME;
 	rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
 
-	if (!rc) {
+	if (rc == 0) {
 		struct addrinfo *cur = result;
 		unsigned cnt = 0;
 
@@ -94,7 +108,7 @@ static int print_host(const char *hostname, const char *header)
 		bb_error_msg("can't resolve '%s'", hostname);
 #endif
 	}
-	if (ENABLE_FEATURE_CLEAN_UP)
+	if (ENABLE_FEATURE_CLEAN_UP && result)
 		freeaddrinfo(result);
 	return (rc != 0);
 }
@@ -133,14 +147,19 @@ static void set_default_dns(const char *server)
 		_res.nsaddr_list[0] = lsa->u.sin;
 	}
 #if ENABLE_FEATURE_IPV6
-// Hoping libc will handle an IPv4 address there too,
-// if it so happens that family is indeed AF_INET
-//	if (lsa->u.sa.sa_family == AF_INET6) {
+	/* Hoped libc can cope with IPv4 address there too.
+	 * No such luck, glibc 2.4 segfaults even with IPv6,
+	 * maybe I misunderstand how to make glibc use IPv6 addr?
+	 * (uclibc 0.9.31+ should work) */
+	if (lsa->u.sa.sa_family == AF_INET6) {
+		// glibc neither SEGVs nor sends any dgrams with this
+		// (strace shows no socket ops):
+		//_res.nscount = 0;
 		_res._u._ext.nscount = 1;
 		/* store a pointer to part of malloc'ed lsa */
 		_res._u._ext.nsaddrs[0] = &lsa->u.sin6;
 		/* must not free(lsa)! */
-//	}
+	}
 #endif
 }