* nss/nss_files/files-hosts.c (LINE_PARSER): Support IPv6-style

	addresses for IPv4 queries if they can be mapped.

ChangeLog

@@ -1,3 +1,8 @@
+2006-11-19  Ulrich Drepper  <drepper@redhat.com>
+
+	* nss/nss_files/files-hosts.c (LINE_PARSER): Support IPv6-style
+	addresses for IPv4 queries if they can be mapped.
+
 2006-11-16  Jakub Jelinek  <jakub@redhat.com>
 
 	* sysdeps/x86_64/fpu/s_copysignf.S (__copysignf): Switch to .text.

nss/nss_files/files-hosts.c

@@ -1,5 +1,5 @@
 /* Hosts file parser in nss_files module.
-   Copyright (C) 1996-2001, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 1996-2001, 2003, 2004, 2006 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -55,14 +55,30 @@ LINE_PARSER
    STRING_FIELD (addr, isspace, 1);
 
    /* Parse address.  */
-   if (inet_pton (af, addr, entdata->host_addr) <= 0
-       && (af != AF_INET6 || (flags & AI_V4MAPPED) == 0
-	   || inet_pton (AF_INET, addr, entdata->host_addr) <= 0
-	   || (map_v4v6_address ((char *) entdata->host_addr,
-				 (char *) entdata->host_addr),
-	       0)))
-     /* Illegal address: ignore line.  */
-     return 0;
+   if (inet_pton (af, addr, entdata->host_addr) <= 0)
+     {
+       if (af == AF_INET6 && (flags & AI_V4MAPPED) != 0
+	   && inet_pton (AF_INET, addr, entdata->host_addr) > 0)
+	 map_v4v6_address ((char *) entdata->host_addr,
+			   (char *) entdata->host_addr);
+       else if (af == AF_INET
+		&& inet_pton (AF_INET6, addr, entdata->host_addr) > 0)
+	 {
+	   if (IN6_IS_ADDR_V4MAPPED (entdata->host_addr))
+	     memcpy (entdata->host_addr, entdata->host_addr + 12, INADDRSZ);
+	   else if (IN6_IS_ADDR_LOOPBACK (entdata->host_addr))
+	     {
+	       in_addr_t localhost = htonl (INADDR_LOOPBACK);
+	       memcpy (entdata->host_addr, &localhost, sizeof (localhost));
+	     }
+	   else
+	     /* Illegal address: ignore line.  */
+	     return 0;
+	 }
+       else
+	 /* Illegal address: ignore line.  */
+	 return 0;
+     }
 
    /* We always return entries of the requested form.  */
    result->h_addrtype = af;