update from main archive 961214 cvs/libc-961215

Sun Dec 15 01:53:20 1996  Ulrich Drepper  <drepper@cygnus.com>

	* Makefile (subdirs): Change crypt to md5-crypt.
	* crypt/Makefile, crypt/md5-crypt.c, crypt/md5.c, crypt/md5.h,
	crypt/md5c-test.c, crypt/md5test.c: Move to new directory
	md5-crypt.
	* sysdeps/unix/sysv/linux/configure.in: Refer to linuxthreads and
	crypt instead of LinuxThreads and des-crypt.

	* Makefile (subdirs): Add nss back.
	* sysdeps/unix/inet/Subdirs: Move nis to end of file to fulfill
	dependencies.

	* libio/iofclose.c: Implement fclose(NULL) as closing all streams.
	* stdio-common/Makefile (routines): Add fcloseall.
	* stdio-common/fcloseall.c: New file.
	* sysdeps/generic/abort.c: Make implementation POSIX.1 compatible.

	* sysdeps/mach/libc-lock.h: Add definition of __libc_lock_trylock.
	* sysdeps/stub/libc-lock.h: Define __libc_lock_trylock to always
	return 0.

	* stdio-common/printf.h: Define MIN and MAX only if not already
	defined.

	* stdio-common/vfprintf.c: Set errno to EBADF if stream does not
	allow writing.  Required by POSIX.1.

	* libio/libioP.h (CHECK_FILE): Use MAYBE_SET_EINVAL instead of
	assignment.

	* interp.c: Update copyright.
	* libio/clearerr.c: Likewise.
	* libio/ioseekoff.c: Likewise.
	* libio/ioseekpos.c: Likewise.
	* stdio/fclose.c: Likewise.
	* stdio/fflus.c: Likewise.

	* libio/libio.h [!_IO_MTSAFE_IO]: Define _IO_cleanup_region_start
	and _IO_cleanup_region_end as empty.
	* libio/fgetc.c: Use _IO_cleanup_region_start and
	_IO_cleanup_region_end instead of __libc_cleanup_region_start and
	__libc_cleanup_region_end.
	* libio/fputc.c: Likewise.
	* libio/freopen.c: Likewise.
	* libio/fseek.c: Likewise.
	* libio/getc.c: Likewise.
	* libio/getchar.c: Likewise.
	* libio/iofclose.c: Likewise.
	* libio/iofflush.c: Likewise.
	* libio/iofgetpos.c: Likewise.
	* libio/iofgets.c: Likewise.
	* libio/iofputs.c: Likewise.
	* libio/iofread.c: Likewise.
	* libio/iofsetpos.c: Likewise.
	* libio/ioftell.c: Likewise.
	* libio/iofwrite.c: Likewise.
	* libio/iogetdelim.c: Likewise.
	* libio/iogets.c: Likewise.
	* libio/ioputs.c: Likewise.
	* libio/iosetbuffer.c: Likewise.
	* libio/iosetvbuf.c: Likewise.
	* libio/ioungetc.c: Likewise.

	* libio/iovspintf.c: Use cleanup handler to make sure no dangling
	locks can stay over.
	* libio/iovsscanf.c: Likewise.

	* libio/genops.c: Use _IO_lock_init_recursive and _IO_lock_fini
	instead of __libc_lock_init_recursive and __libc_lock_fini.

	* libio/filedoalloc.c: Only use __isatty when compiling GNU libc.
	Otherwise use isatty.
	* libio/fileops.c: Likewise for __open and open.

	* login/utmp_file.c (getutent_r_file): Use fcntl instead of
	flock.

	* nis/ypclnt.h: Add more casts to prevent warnings.

	* nss/Makefile (services): Remove dns.
	(libnss_dns, libnss_dns-inhibit-o): Remove definition.
	($(objpfx)libnss_dns.so): Removed.
	* nss/nss_dns/dns-host.c, nss/nss_dns/dns-network.c: Moved to...
	* resolv/nss_dns: ...here.
	* resolv/Makefile (extra-libs): Add libnss_dns.
	(libnss_dns-routines, libnss_dns-inhibit-o): Define as in
	nss/Makefile.

	* nss/XXX-lookup.c: Call __nss_database_lookup with new argument
	specifying alternate name for entry in /etc/nsswitch.conf
	* nss/nsswitch.c: If no entry with primary name is found in
	/etc/nsswitch.conf try alternate name if given.
	* nss/nsswitch.h: Add new parameter in prototype for
	__nss_database_lookup.
	* nss/spwd-lookup.c: Provide alternative entry name to look for.
	This makes our NSS compatible with Solaris' nsswitch.conf files.

	* string/tst-strlen.c: Change all counting variables to type size_t
	to prevent warnings.

	* sysdeps/posix/fpathconf.c: Update copyright.
	* sysdeps/posix/pathconf.c: Don't call fpathconf to do the work.
	Opening the file at this path may fail if it is a FIFO or pipe.

	These changes make the time implementation POSIX.1 compliant.
	* time/localtime.c (__localtime_r): Always call __tzset not only
	if __tzset_run is zero.
	* time/strftime.c: Add definition of memset_space to help to
	reduce for systems which have memset.
	(strftime): Don't use tm_zone member of argument for zone name.
	Instead always use tzname[].
	Call tzset() as required by POSIX.1 before any action.
	* time/tzset.c (tzset): Set tzname[] as required by POSIX.1.
	Remove global variable __tzset_run.  __tzset is now called always
	when a dependent function is used.
	(__tzset): Caching happens based on the contents of the
	environment variable TZ.

Fri Dec 13 01:06:52 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/unix/sysv/linux/paths.h: Add _PATH_KLOG.

Thu Dec 12 09:16:35 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* rellns-sh: Correctly handle a relative source file name.

Wed Dec 11 19:18:40 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* login/utmp_file.c (setutent_file): Seek back to beginning of the
	file if resetting.

Thu Dec 12 16:39:12 1996  Thomas Bushnell, n/BSG  <thomas@gnu.ai.mit.edu>

	* hurd/hurdinit.c (map0): Delete function.  Don't do this on
	_hurd_preinit_hook.
	* hurd/hurdstartup.c (_hurd_startup): Map page zero redzone here.

3 files changed, 1010 insertions, 1 deletions

diff --git a/resolv/Makefile b/resolv/Makefile
index 962dbca0b9..a70ee99d08 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -27,12 +27,17 @@ distribute := ../conf/portability.h mapv4v6addr.h mapv4v6hostent.h \
 
 routines := herror inet_addr inet_ntop inet_pton nsap_addr res_init
 
-extra-libs := libresolv
+extra-libs := libresolv libnss_dns
 extra-libs-others = $(extra-libs)
 libresolv-routines := gethnamaddr res_comp res_debug	\
 		      res_data res_mkquery res_query res_send		\
 		      inet_net_ntop inet_net_pton inet_neta base64
 
+vpath %.c nss_dns
+
+libnss_dns-routines	:= dns-host dns-network
+libnss_dns-inhibit-o	= $(filter-out .so,$(object-suffixes))
+
 include ../Rules
 
 CPPFLAGS += -Dgethostbyname=res_gethostbyname \
@@ -48,3 +53,6 @@ CPPFLAGS += -Dgethostbyname=res_gethostbyname \
 # This ensures they will load libc.so for needed symbols if loaded by
 # a statically-linked program that hasn't already loaded it.
 $(objpfx)libresolv.so: $(common-objpfx)libc.so
+
+# The DNS NSS modules needs the resolver.
+$(objpfx)libnss_dns.so: $(objpfx)libresolv.so
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
new file mode 100644
index 0000000000..e4a9c788ce
--- /dev/null
+++ b/resolv/nss_dns/dns-host.c
@@ -0,0 +1,658 @@
+/* Copyright (C) 1996 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* Parts of this file are plain copies of the file `gethtnamadr.c' from
+   the bind package and it has the following copyright.  */
+
+/*
+ * ++Copyright++ 1985, 1988, 1993
+ * -
+ * Copyright (c) 1985, 1988, 1993
+ *    The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ * 	This product includes software developed by the University of
+ * 	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * -
+ * Portions Copyright (c) 1993 by Digital Equipment Corporation.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies, and that
+ * the name of Digital Equipment Corporation not be used in advertising or
+ * publicity pertaining to distribution of the document or software without
+ * specific, written prior permission.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
+ * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ * -
+ * --Copyright--
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/syslog.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+
+#include "nsswitch.h"
+
+/* Get implementation for some internal functions.  */
+#include "../resolv/mapv4v6addr.h"
+#include "../resolv/mapv4v6hostent.h"
+
+/* Maximum number of aliases we allow.  */
+#define MAX_NR_ALIASES	48
+#define MAX_NR_ADDRS	48
+
+#if PACKETSZ > 1024
+# define MAXPACKET	PACKETSZ
+#else
+# define MAXPACKET	1024
+#endif
+
+static const char AskedForGot[] = "\
+gethostby*.getanswer: asked for \"%s\", got \"%s\"";
+
+
+/* We need this time later.  */
+typedef union querybuf
+{
+  HEADER hdr;
+  u_char buf[MAXPACKET];
+} querybuf;
+
+
+static enum nss_status getanswer_r (const querybuf *answer, int anslen,
+				    const char *qname, int qtype,
+				    struct hostent *result,
+				    char *buffer, int buflen, int *h_errnop);
+
+enum nss_status
+_nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
+			   char *buffer, int buflen, int *h_errnop)
+{
+  struct host_data
+  {
+    char *aliases[MAX_NR_ALIASES];
+    unsigned char host_addr[16];	/* IPv4 or IPv6 */
+    char *h_addr_ptrs[MAX_NR_ADDRS + 1];
+    char linebuffer[0];
+  } *host_data = (struct host_data *) buffer;
+  int linebuflen = buflen - offsetof (struct host_data, linebuffer);
+  querybuf host_buffer;
+  int size, type, n;
+  const char *cp;
+
+  switch (af) {
+  case AF_INET:
+    size = INADDRSZ;
+    type = T_A;
+    break;
+  case AF_INET6:
+    size = IN6ADDRSZ;
+    type = T_AAAA;
+    break;
+  default:
+    *h_errnop = NETDB_INTERNAL;
+    __set_errno (EAFNOSUPPORT);
+    return NSS_STATUS_UNAVAIL;
+  }
+
+  result->h_addrtype = af;
+  result->h_length = size;
+
+  /*
+   * if there aren't any dots, it could be a user-level alias.
+   * this is also done in res_query() since we are not the only
+   * function that looks up host names.
+   */
+  if (strchr (name, '.') == NULL && (cp = __hostalias (name)) != NULL)
+    name = cp;
+
+  /*
+   * disallow names consisting only of digits/dots, unless
+   * they end in a dot.
+   */
+  if (isdigit (name[0]))
+    for (cp = name;; ++cp)
+      {
+	if (*cp == '\0')
+	  {
+	    char *bp;
+
+	    if (*--cp == '.')
+	      break;
+	    /*
+	     * All-numeric, no dot at the end.  Fake up a hostent
+	     * as if we'd actually done a lookup.
+	     */
+	    if (inet_pton (af, name, host_data->host_addr) <= 0)
+	      {
+		*h_errnop = HOST_NOT_FOUND;
+		return NSS_STATUS_NOTFOUND;
+	      }
+
+	    bp = __stpncpy (host_data->linebuffer, name, linebuflen);
+	    host_data->linebuffer[linebuflen - 1] = '\0';
+	    linebuflen -= bp - host_data->linebuffer;
+
+	    result->h_name = host_data->linebuffer;
+	    result->h_aliases = host_data->aliases;
+	    host_data->aliases[0] = NULL;
+	    host_data->h_addr_ptrs[0] = (char *) host_data->host_addr;
+	    host_data->h_addr_ptrs[1] = NULL;
+	    result->h_addr_list = host_data->h_addr_ptrs;
+
+	    if (_res.options & RES_USE_INET6)
+	      map_v4v6_hostent (result, &bp, &linebuflen);
+	    *h_errnop = NETDB_SUCCESS;
+	    return NSS_STATUS_SUCCESS;
+	  }
+	if (!isdigit (*cp) && *cp != '.')
+	  break;
+      }
+  if (isxdigit (name[0]) || name[0] == ':')
+    for (cp = name;; ++cp)
+      {
+	if (*cp == '\0')
+	  {
+	    char *bp;
+
+	    if (*--cp == '.')
+	      break;
+	    /*
+	     * All-IPv6-legal, no dot at the end.  Fake up a hostent
+	     * as if we'd actually done a lookup.
+	     */
+	    if (inet_pton (af, name, host_data->host_addr) <= 0)
+	      {
+		*h_errnop = HOST_NOT_FOUND;
+		return NSS_STATUS_NOTFOUND;
+	      }
+
+	    bp = __stpncpy (host_data->linebuffer, name, linebuflen);
+	    host_data->linebuffer[linebuflen - 1] = '\0';
+	    linebuflen -= bp - host_data->linebuffer;
+
+	    result->h_name = host_data->linebuffer;
+	    result->h_aliases = host_data->aliases;
+	    host_data->aliases[0] = NULL;
+	    host_data->h_addr_ptrs[0] = (char *) host_data->host_addr;
+	    host_data->h_addr_ptrs[1] = NULL;
+	    result->h_addr_list = host_data->h_addr_ptrs;
+	    *h_errnop = NETDB_SUCCESS;
+	    return NSS_STATUS_SUCCESS;
+	  }
+	if (!isxdigit (*cp) && *cp != ':' && *cp != '.')
+	  break;
+      }
+
+  n = res_search (name, C_IN, type, host_buffer.buf, sizeof (host_buffer));
+  if (n < 0)
+    return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+
+  return getanswer_r (&host_buffer, n, name, type, result, buffer, buflen,
+		      h_errnop);
+}
+
+
+enum nss_status
+_nss_dns_gethostbyname_r (const char *name, struct hostent *result,
+			  char *buffer, int buflen, int *h_errnop)
+{
+  enum nss_status status = NSS_STATUS_NOTFOUND;
+
+  if (_res.options & RES_USE_INET6)
+    status = _nss_dns_gethostbyname2_r (name, AF_INET6, result, buffer,
+					buflen, h_errnop);
+  if (status == NSS_STATUS_NOTFOUND)
+    status = _nss_dns_gethostbyname2_r (name, AF_INET, result, buffer,
+					buflen, h_errnop);
+
+  return status;
+}
+
+
+enum nss_status
+_nss_dns_gethostbyaddr_r (const char *addr, int len, int af,
+			  struct hostent *result, char *buffer, int buflen,
+			  int *h_errnop)
+{
+  static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
+  static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
+  const u_char *uaddr = (const u_char *)addr;
+  struct host_data
+  {
+    char *aliases[MAX_NR_ALIASES];
+    unsigned char host_addr[16];	/* IPv4 or IPv6 */
+    char *h_addr_ptrs[MAX_NR_ADDRS + 1];
+    char linebuffer[0];
+  } *host_data = (struct host_data *) buffer;
+  querybuf host_buffer;
+  char qbuf[MAXDNAME+1], *qp;
+  int size, n, status;
+
+  if (af == AF_INET6 && len == IN6ADDRSZ &&
+      (bcmp (uaddr, mapped, sizeof mapped) == 0
+       || bcmp (uaddr, tunnelled, sizeof tunnelled) == 0))
+    {
+      /* Unmap. */
+      addr += sizeof mapped;
+      uaddr += sizeof mapped;
+      af = AF_INET;
+      len = INADDRSZ;
+    }
+
+  switch (af)
+    {
+    case AF_INET:
+      size = INADDRSZ;
+      break;
+    case AF_INET6:
+      size = IN6ADDRSZ;
+      break;
+    default:
+      __set_errno (EAFNOSUPPORT);
+      *h_errnop = NETDB_INTERNAL;
+      return NSS_STATUS_UNAVAIL;
+    }
+  if (size != len)
+    {
+      __set_errno (EAFNOSUPPORT);
+      *h_errnop = NETDB_INTERNAL;
+      return NSS_STATUS_UNAVAIL;
+    }
+
+  switch (af)
+    {
+    case AF_INET:
+      sprintf (qbuf, "%u.%u.%u.%u.in-addr.arpa", (uaddr[3] & 0xff),
+	       (uaddr[2] & 0xff), (uaddr[1] & 0xff), (uaddr[0] & 0xff));
+      break;
+    case AF_INET6:
+      qp = qbuf;
+      for (n = IN6ADDRSZ - 1; n >= 0; n--)
+	qp += sprintf (qp, "%x.%x.", uaddr[n] & 0xf, (uaddr[n] >> 4) & 0xf);
+      strcpy(qp, "ip6.int");
+      break;
+    default:
+      /* Cannot happen.  */
+    }
+
+  n = res_query (qbuf, C_IN, T_PTR, (u_char *)host_buffer.buf,
+		 sizeof host_buffer);
+  if (n < 0)
+    return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+
+  status = getanswer_r (&host_buffer, n, qbuf, T_PTR, result, buffer, buflen,
+			h_errnop);
+  if (status != NSS_STATUS_SUCCESS)
+    return status;
+
+#ifdef SUNSECURITY
+  This is not implemented because it is not possible to use the current
+  source from bind in a multi-threaded program.
+#endif
+
+  result->h_addrtype = af;
+  result->h_length = len;
+  bcopy (addr, host_data->host_addr, len);
+  host_data->h_addr_ptrs[0] = (char *) host_data->host_addr;
+  host_data->h_addr_ptrs[1] = NULL;
+  if (af == AF_INET && (_res.options & RES_USE_INET6))
+    {
+      map_v4v6_address ((char *) host_data->host_addr,
+			(char *) host_data->host_addr);
+      result->h_addrtype = AF_INET6;
+      result->h_length = IN6ADDRSZ;
+    }
+  *h_errnop = NETDB_SUCCESS;
+  return NSS_STATUS_SUCCESS;
+}
+
+
+static enum nss_status
+getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
+	     struct hostent *result, char *buffer, int buflen, int *h_errnop)
+{
+  struct host_data
+  {
+    char *aliases[MAX_NR_ALIASES];
+    unsigned char host_addr[16];	/* IPv4 or IPv6 */
+    char *h_addr_ptrs[MAX_NR_ADDRS + 1];
+    char linebuffer[0];
+  } *host_data = (struct host_data *) buffer;
+  int linebuflen = buflen - offsetof (struct host_data, linebuffer);
+  register const HEADER *hp;
+  const u_char *end_of_message, *cp;
+  int n, ancount, qdcount;
+  int haveanswer, had_error;
+  char *bp, **ap, **hap;
+  char tbuf[MAXDNAME];
+  const char *tname;
+  int (*name_ok) __P ((const char *));
+
+  tname = qname;
+  result->h_name = NULL;
+  end_of_message = answer->buf + anslen;
+  switch (qtype)
+    {
+    case T_A:
+    case T_AAAA:
+      name_ok = res_hnok;
+      break;
+    case T_PTR:
+      name_ok = res_dnok;
+      break;
+    default:
+      return NSS_STATUS_UNAVAIL;  /* XXX should be abort(); */
+    }
+
+  /*
+   * find first satisfactory answer
+   */
+  hp = &answer->hdr;
+  bp = host_data->linebuffer;
+  ancount = ntohs (hp->ancount);
+  qdcount = ntohs (hp->qdcount);
+  cp = answer->buf + HFIXEDSZ;
+  if (qdcount != 1)
+    {
+      *h_errnop = NO_RECOVERY;
+      return NSS_STATUS_UNAVAIL;
+    }
+
+  n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
+  if (n < 0 || (*name_ok) (bp) == 0)
+    {
+      *h_errnop = NO_RECOVERY;
+      return NSS_STATUS_UNAVAIL;
+    }
+  cp += n + QFIXEDSZ;
+
+  if (qtype == T_A || qtype == T_AAAA)
+    {
+      /* res_send() has already verified that the query name is the
+       * same as the one we sent; this just gets the expanded name
+       * (i.e., with the succeeding search-domain tacked on).
+       */
+      n = strlen (bp) + 1;             /* for the \0 */
+      result->h_name = bp;
+      bp += n;
+      linebuflen -= n;
+      /* The qname can be abbreviated, but h_name is now absolute. */
+      qname = result->h_name;
+    }
+
+  ap = host_data->aliases;
+  *ap = NULL;
+  result->h_aliases = host_data->aliases;
+  hap = host_data->h_addr_ptrs;
+  *hap = NULL;
+  result->h_addr_list = host_data->h_addr_ptrs;
+  haveanswer = 0;
+  had_error = 0;
+
+  while (ancount-- > 0 && cp < end_of_message && had_error == 0)
+    {
+      int type, class;
+
+      n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
+      if (n < 0 || (*name_ok) (bp) == 0)
+	{
+	  ++had_error;
+	  continue;
+	}
+      cp += n;				/* name */
+      type = _getshort (cp);
+      cp += INT16SZ;			/* type */
+      class = _getshort(cp);
+      cp += INT16SZ + INT32SZ;		/* class, TTL */
+      n = _getshort(cp);
+      cp += INT16SZ;			/* len */
+      if (class != C_IN)
+	{
+	  /* XXX - debug? syslog? */
+	  cp += n;
+	  continue;			/* XXX - had_error++ ? */
+	}
+
+      if ((qtype ==T_A || qtype == T_AAAA) && type == T_CNAME)
+	{
+	  if (ap >= &host_data->aliases[MAX_NR_ALIASES - 1])
+	    continue;
+	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
+	  if (n < 0 || (*name_ok) (tbuf) == 0)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  cp += n;
+	  /* Store alias.  */
+	  *ap++ = bp;
+	  n = strlen (bp) + 1;		/* For the \0.  */
+	  bp += n;
+	  linebuflen -= n;
+	  /* Get canonical name.  */
+	  n = strlen (tbuf) + 1;	/* For the \0.  */
+	  if (n > buflen)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  strcpy (bp, tbuf);		/* Cannot overflow.  */
+	  result->h_name = bp;
+	  bp += n;
+	  linebuflen -= n;
+	  continue;
+	}
+
+      if (qtype == T_PTR && type == T_CNAME)
+	{
+	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
+	  if (n < 0 || res_hnok (tbuf) == 0)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  cp += n;
+	  /* Get canonical name. */
+	  n = strlen (tbuf) + 1;   /* For the \0.  */
+	  if (n > buflen)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  strcpy (bp, tbuf);		/* Cannot overflow.  */
+	  tname = bp;
+	  bp += n;
+	  linebuflen -= n;
+	  continue;
+	}
+      if (type != qtype)
+	{
+	  syslog (LOG_NOTICE | LOG_AUTH,
+	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
+		  qname, p_class (C_IN), p_type (qtype), p_type (type));
+	  cp += n;
+	  continue;			/* XXX - had_error++ ? */
+	}
+
+      switch (type)
+	{
+	case T_PTR:
+	  if (strcasecmp (tname, bp) != 0)
+	    {
+	      syslog (LOG_NOTICE | LOG_AUTH, AskedForGot, qname, bp);
+	      cp += n;
+	      continue;			/* XXX - had_error++ ? */
+	    }
+	  n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
+	  if (n < 0 || res_hnok (bp) == 0)
+	    {
+	      ++had_error;
+	      break;
+	    }
+#if MULTI_PTRS_ARE_ALIASES
+	  cp += n;
+	  if (haveanswer == 0)
+	    result->h_name = bp;
+	  else if (ap < &host_data->aliases[MAXALIASES-1])
+	    *ap++ = bp;
+	  else
+	    n = -1;
+	  if (n != -1)
+	    {
+	      n = strlen (bp) + 1;	/* for the \0 */
+	      bp += n;
+	      linebuflen -= n;
+	    }
+	  break;
+#else
+	  result->h_name = bp;
+	  if (_res.options & RES_USE_INET6)
+	    {
+	      n = strlen (bp) + 1;	/* for the \0 */
+	      bp += n;
+	      linebuflen -= n;
+	      map_v4v6_hostent (result, &bp, &linebuflen);
+	    }
+	  *h_errnop = NETDB_SUCCESS;
+	  return NSS_STATUS_SUCCESS;
+#endif
+	case T_A:
+	case T_AAAA:
+	  if (strcasecmp (result->h_name, bp) != 0)
+	    {
+	      syslog (LOG_NOTICE | LOG_AUTH, AskedForGot, result->h_name, bp);
+	      cp += n;
+	      continue;			/* XXX - had_error++ ? */
+	    }
+	  if (n != result->h_length)
+	    {
+	      cp += n;
+	      continue;
+	    }
+	  if (!haveanswer)
+	    {
+	      register int nn;
+
+	      result->h_name = bp;
+	      nn = strlen (bp) + 1;	/* for the \0 */
+	      bp += nn;
+	      linebuflen -= nn;
+	    }
+
+	  bp += sizeof (align) - ((u_long) bp % sizeof (align));
+
+	  if (n >= linebuflen)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  if (hap >= &host_data->h_addr_ptrs[MAX_NR_ADDRS-1])
+	    {
+	      cp += n;
+	      continue;
+	    }
+	  bcopy (cp, *hap++ = bp, n);
+	  bp += n;
+	  cp += n;
+	  linebuflen -= n;
+	  break;
+	default:
+	  abort ();
+	}
+      if (had_error == 0)
+	++haveanswer;
+    }
+
+  if (haveanswer > 0)
+    {
+      *ap = NULL;
+      *hap = NULL;
+#if defined(RESOLVSORT)
+      /*
+       * Note: we sort even if host can take only one address
+       * in its return structures - should give it the "best"
+       * address in that case, not some random one
+       */
+      if (_res.nsort && haveanswer > 1 && qtype == T_A)
+	addrsort (host_data->h_addr_ptrs, haveanswer);
+#endif /*RESOLVSORT*/
+
+      if (result->h_name == NULL)
+	{
+	  n = strlen (qname) + 1;	/* For the \0.  */
+	  if (n > linebuflen)
+	    goto try_again;
+	  strcpy (bp, qname);		/* Cannot overflow.  */
+	  result->h_name = bp;
+	  bp += n;
+	  linebuflen -= n;
+	}
+
+      if (_res.options & RES_USE_INET6)
+	map_v4v6_hostent (result, &bp, &linebuflen);
+      *h_errnop = NETDB_SUCCESS;
+      return NSS_STATUS_SUCCESS;
+    }
+try_again:
+  *h_errnop = TRY_AGAIN;
+  return NSS_STATUS_TRYAGAIN;
+}
diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
new file mode 100644
index 0000000000..94fa1c13c4
--- /dev/null
+++ b/resolv/nss_dns/dns-network.c
@@ -0,0 +1,343 @@
+/* Copyright (C) 1996 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* Parts of this file are plain copies of the file `getnetnamadr.c' from
+   the bind package and it has the following copyright.  */
+
+/* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
+ *      Dep. Matematica Universidade de Coimbra, Portugal, Europe
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+/*
+ * Copyright (c) 1983, 1993
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by the University of
+ *      California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "nsswitch.h"
+#include <arpa/inet.h>
+
+/* Maximum number of aliases we allow.  */
+#define MAX_NR_ALIASES	48
+
+
+#if PACKETSZ > 1024
+#define MAXPACKET       PACKETSZ
+#else
+#define MAXPACKET       1024
+#endif
+
+
+typedef enum
+{
+  BYADDR,
+  BYNAME
+} lookup_method;
+
+
+/* We need this time later.  */
+typedef union querybuf
+{
+  HEADER hdr;
+  u_char buf[MAXPACKET];
+} querybuf;
+
+
+/* Protortypes for local functions.  */
+static enum nss_status getanswer_r (const querybuf *answer, int anslen,
+				    struct netent *result, char *buffer,
+				    int buflen, lookup_method net_i);
+
+
+enum nss_status
+_nss_dns_getnetbyname_r (const char *name, struct netent *result,
+			 char *buffer, int buflen)
+{
+  /* Return entry for network with NAME.  */
+  querybuf net_buffer;
+  int anslen;
+  char *qbuf;
+
+  qbuf = strdupa (name);
+  anslen = res_search (qbuf, C_IN, T_PTR, (u_char *) &net_buffer,
+		       sizeof (querybuf));
+  if (anslen < 0)
+    /* Nothing found.  */
+    return (errno == ECONNREFUSED
+	    || errno == EPFNOSUPPORT
+	    || errno == EAFNOSUPPORT)
+      ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+
+  return getanswer_r (&net_buffer, anslen, result, buffer, buflen, BYNAME);
+}
+
+
+enum nss_status
+_nss_dns_getnetbyaddr_r (long net, int type, struct netent *result,
+			 char *buffer, int buflen)
+{
+  /* Return entry for network with NAME.  */
+  enum nss_status status;
+  querybuf net_buffer;
+  unsigned int net_bytes[4];
+  char qbuf[MAXDNAME];
+  int cnt, anslen;
+  u_int32_t net2;
+
+  /* No net address lookup for IPv6 yet.  */
+  if (type != AF_INET)
+    return NSS_STATUS_UNAVAIL;
+
+  net2 = (u_int32_t) net;
+  for (cnt = 4; net2 != 0; net2 >>= 8)
+    net_bytes[--cnt] = net2 & 0xff;
+
+  switch (cnt)
+    {
+    case 3:
+      /* Class A network.  */
+      sprintf (qbuf, "0.0.0.%u.in-addr.arpa", net_bytes[3]);
+      break;
+    case 2:
+      /* Class B network.  */
+      sprintf (qbuf, "0.0.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2]);
+      break;
+    case 1:
+      /* Class C network.  */
+      sprintf (qbuf, "0.%u.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2],
+	       net_bytes[1]);
+      break;
+    case 0:
+      /* Class D - E network.  */
+      sprintf (qbuf, "%u.%u.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2],
+	       net_bytes[1], net_bytes[0]);
+      break;
+    }
+
+  anslen = res_query (qbuf, C_IN, T_PTR, (u_char *) &net_buffer,
+		      sizeof (querybuf));
+  if (anslen < 0)
+    /* Nothing found.  */
+    return (errno == ECONNREFUSED
+	    || errno == EPFNOSUPPORT
+	    || errno == EAFNOSUPPORT)
+      ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+
+  status = getanswer_r (&net_buffer, anslen, result, buffer, buflen, BYADDR);
+  if (status == NSS_STATUS_SUCCESS)
+    {
+      /* Strip trailing zeros.  */
+      unsigned int u_net = net;	/* Maybe net should be unsigned?  */
+
+      while ((u_net & 0xff) == 0 && u_net != 0)
+	u_net >>= 8;
+      result->n_net = u_net;
+    }
+
+  return status;
+}
+
+
+#undef offsetof
+#define offsetof(Type, Member) ((size_t) &((Type *) NULL)->Member)
+
+static enum nss_status
+getanswer_r (const querybuf *answer, int anslen, struct netent *result,
+	     char *buffer, int buflen, lookup_method net_i)
+{
+  /*
+   * Find first satisfactory answer
+   *
+   *      answer --> +------------+  ( MESSAGE )
+   *                 |   Header   |
+   *                 +------------+
+   *                 |  Question  | the question for the name server
+   *                 +------------+
+   *                 |   Answer   | RRs answering the question
+   *                 +------------+
+   *                 | Authority  | RRs pointing toward an authority
+   *                 | Additional | RRs holding additional information
+   *                 +------------+
+   */
+  struct net_data
+  {
+    char *aliases[MAX_NR_ALIASES];
+    char linebuffer[0];
+  } *net_data = (struct net_data *) buffer;
+  int linebuflen = buflen - offsetof (struct net_data, linebuffer);
+  const char *end_of_message = &answer->buf[anslen];
+  const HEADER *header_pointer = &answer->hdr;
+  /* #/records in the answer section.  */
+  int answer_count =  ntohs (header_pointer->ancount);
+  /* #/entries in the question section.  */
+  int question_count = ntohs (header_pointer->qdcount);
+  char *bp = net_data->linebuffer;
+  const char *cp = &answer->buf[HFIXEDSZ];
+  char **alias_pointer;
+  int have_answer;
+  char *ans;
+
+  if (question_count == 0)
+    /* FIXME: the Sun version uses for host name lookup an additional
+       parameter for pointing to h_errno.  this is missing here.
+       OSF/1 has a per-thread h_errno variable.  */
+    if (header_pointer->aa != 0)
+      {
+	__set_h_errno (HOST_NOT_FOUND);
+	return NSS_STATUS_NOTFOUND;
+      }
+    else
+      {
+	__set_h_errno (TRY_AGAIN);
+	return NSS_STATUS_TRYAGAIN;
+      }
+
+  /* Skip the question part.  */
+  while (question_count-- > 0)
+    cp += __dn_skipname (cp, end_of_message) + QFIXEDSZ;
+
+  alias_pointer = result->n_aliases = &net_data->aliases[0];
+  *alias_pointer = NULL;
+  have_answer = 0;
+  ans = NULL;
+
+  while (--answer_count >= 0 && cp < end_of_message)
+    {
+      int n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
+      int type, class;
+
+      if (n < 0 || res_dnok (bp) == 0)
+	break;
+      cp += n;
+      ans = strdupa (bp);
+      GETSHORT (type, cp);
+      GETSHORT (class, cp);
+      cp += INT32SZ;		/* TTL */
+      GETSHORT (n, cp);
+
+      if (class == C_IN && type == T_PTR)
+	{
+	  n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
+	  if (n < 0 || !res_hnok (bp))
+	    {
+	      /* XXX What does this mean?  The original form from bind
+		 returns NULL. Incrementing cp has no effect in any case.
+		 What should I return here. ??? */
+	      cp += n;
+	      return NSS_STATUS_UNAVAIL;
+	    }
+	  cp += n;
+	  *alias_pointer++ = bp;
+	  bp += strlen (bp) + 1;
+	  result->n_addrtype = class == C_IN ? AF_INET : AF_UNSPEC;
+	  ++have_answer;
+	}
+    }
+
+  if (have_answer)
+    {
+      char *tmp;
+      int len;
+      char *in, *cp, *rp, *wp;
+      int cnt, first_flag;
+
+      *alias_pointer = NULL;
+      switch (net_i)
+	{
+	case BYADDR:
+	  result->n_name = result->n_aliases[0];
+	  result->n_net = 0L;
+	  break;
+	case BYNAME:
+	  len = strlen (result->n_aliases[0]);
+	  tmp = (char *) alloca (len + 1);
+	  tmp[len] = 0;
+	  wp = &tmp[len - 1];
+
+	  rp = in = result->n_aliases[0];
+	  result->n_name = ans;
+
+	  first_flag = 1;
+	  for (cnt = 0; cnt < 4; ++cnt)
+	    {
+	      char *startp;
+
+	      startp = rp;
+	      while (*rp != '.')
+		++rp;
+	      if (rp - startp > 1 || *startp != '0' || !first_flag)
+		{
+		  first_flag = 0;
+		  if (cnt > 0)
+		    *wp-- = '.';
+		  cp = rp;
+		  while (cp > startp)
+		    *wp-- = *--cp;
+		}
+	      in = rp + 1;
+	    }
+
+	  result->n_net = inet_network (wp);
+	  break;
+	}
+
+      ++result->n_aliases;
+      return NSS_STATUS_SUCCESS;
+    }
+
+  __set_h_errno (TRY_AGAIN);
+  return NSS_STATUS_TRYAGAIN;
+}