From e84892eb74b92e04c93beb0755687760351864b8 Mon Sep 17 00:00:00 2001
From: Hajimu UMEMOTO <ume@FreeBSD.org>
Date: Sat, 30 Apr 2005 20:07:01 +0000
Subject: [PATCH] oops, gethostbyaddr(3) must return h_addr as an IPv4-mapped
 IPv6 address when RES_USE_INET6 was set, according to RFC 2133 section 6.2.

---
 lib/libc/net/gethostbyht.c   | 9 ++++++++-
 lib/libc/net/gethostbynis.c  | 9 ++++-----
 lib/libc/net/gethostnamadr.c | 5 +++++
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/lib/libc/net/gethostbyht.c b/lib/libc/net/gethostbyht.c
index 452a6da1d032..d1ef23bc6477 100644
--- a/lib/libc/net/gethostbyht.c
+++ b/lib/libc/net/gethostbyht.c
@@ -246,8 +246,15 @@ _ht_gethostbyaddr(void *rval, void *cb_data, va_list ap)
 
 	sethostent_r(0, hed);
 	while ((error = gethostent_p(he, hed, 0)) == 0)
-		if (he->h_addrtype == af && !bcmp(he->h_addr, addr, len))
+		if (he->h_addrtype == af && !bcmp(he->h_addr, addr, len)) {
+			if (he->h_addrtype == AF_INET &&
+			    _res.options & RES_USE_INET6) {
+				_map_v4v6_address(he->h_addr, he->h_addr);
+				he->h_length = IN6ADDRSZ;
+				he->h_addrtype = AF_INET6;
+			}
 			break;
+		}
 	endhostent_r(hed);
 
 	return (error == 0) ? NS_SUCCESS : NS_NOTFOUND;
diff --git a/lib/libc/net/gethostbynis.c b/lib/libc/net/gethostbynis.c
index 45aed338ef4f..ca1a9a56ad87 100644
--- a/lib/libc/net/gethostbynis.c
+++ b/lib/libc/net/gethostbynis.c
@@ -50,7 +50,7 @@ __FBSDID("$FreeBSD$");
 #ifdef YP
 static int
 _gethostbynis(const char *name, char *map, int af, struct hostent *he,
-    struct hostent_data *hed, int mapped)
+    struct hostent_data *hed)
 {
 	char *p, *bp, *ep;
 	char *cp, **q;
@@ -101,7 +101,7 @@ _gethostbynis(const char *name, char *map, int af, struct hostent *he,
 		addrok = inet_aton(result, (struct in_addr *)hed->host_addr);
 		if (addrok != 1)
 			break;
-		if (mapped) {
+		if (_res.options & RES_USE_INET6) {
 			_map_v4v6_address((char *)hed->host_addr,
 			    (char *)hed->host_addr);
 			af = AF_INET6;
@@ -172,8 +172,7 @@ _gethostbynisname_r(const char *name, int af, struct hostent *he,
 		map = "ipnodes.byname";
 		break;
 	}
-	return _gethostbynis(name, map, af, he, hed,
-	    _res.options & RES_USE_INET6);
+	return _gethostbynis(name, map, af, he, hed);
 }
 
 static int
@@ -193,7 +192,7 @@ _gethostbynisaddr_r(const char *addr, int len, int af, struct hostent *he,
 	}
 	if (inet_ntop(af, addr, numaddr, sizeof(numaddr)) == NULL)
 		return -1;
-	return _gethostbynis(numaddr, map, af, he, hed, 0);
+	return _gethostbynis(numaddr, map, af, he, hed);
 }
 #endif /* YP */
 
diff --git a/lib/libc/net/gethostnamadr.c b/lib/libc/net/gethostnamadr.c
index 8aae1922458d..0646b0cb4b4b 100644
--- a/lib/libc/net/gethostnamadr.c
+++ b/lib/libc/net/gethostnamadr.c
@@ -264,6 +264,11 @@ gethostbyaddr_r(const char *addr, int len, int af, struct hostent *he,
 		{ 0 }
 	};
 
+	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
+		h_errno = NETDB_INTERNAL;
+		return -1;
+	}
+
 	if (af == AF_INET6 && len == IN6ADDRSZ) {
 		addr6 = (const struct in6_addr *)(const void *)uaddr;
 		if (IN6_IS_ADDR_LINKLOCAL(addr6)) {