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authorRoland McGrath <roland@gnu.org>1996-06-25 08:56:57 +0000
committerRoland McGrath <roland@gnu.org>1996-06-25 08:56:57 +0000
commit5f0e6fc702296840d2daa39f83f6cb1e40073d58 (patch)
tree6e6c29e50f713eac4c87b54a6e5730fa0dedb65a /nss/nss_dns
parent7f8116797fdb967571c00ec1d5b19d9d06813445 (diff)
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Tue Jun 25 02:59:11 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> cvs/libc-960625
	* malloc/malloc.h: Declare malloc_object_allocated_size, malloc_walk.
	* malloc/Makefile (dist-routines): Add malloc-size, malloc-walk.
	* malloc/malloc-size.c: New file.
	* malloc/malloc-walk.c: New file.

	* malloc/malloc-find.c (malloc_find_object_address): Return null if
	PTR is outside the heap.

	* elf/dl-load.c (_dl_map_object): If the requested name matches the
 	soname of a loaded object, use that object.

Mon Jun 24 19:57:01 1996  Roland McGrath  <roland@delasyd.gnu.ai.mit.edu>

	* Makefile (subdirs): Add nss.

	* inet/Makefile (routines): Add getrpcent, getrpcbyname,
	getrpcbynumber, getrpcent_r, getrpcbyname_r, getrpcbynumber_r.
	* inet/getrpcbynumber_r.c: New file.
	* inet/getrpcbynumber.c: New file.
	* inet/getrpcbyname.c: New file.
	* inet/getrpcbyname_r.c: New file.
	* inet/getrpcent_r.c: New file.
	* inet/getrpcent.c: New file.
	* nss/rpc-lookup.c: New file.
	* nss/nss_files/files-rpc.c: New file.
	* nss/Makefile (routines): Add rpc-lookup.
	(libnss_files-routines): Add files-rpc.
	* sunrpc/Makefile (routines): Remove getrpcent.
	* sunrpc/getrpcent.c: File removed.

	* nss/getXXent_r.c (REENTRANT_GETNAME): Clear NO_MORE when NIP is
	non-null on entry.

	* Makeconfig (rpath-link): Add $(nssobjdir).
	(nssobjdir): New variable.

	* Makerules: Move shared library building before objects rules, so
	versions are known before extra-lib.mk gets included.
	* extra-lib.mk (lib-noranlib): Depend on the shared object too.

	* pwd/getpwuid.c: Rewritten using nss.
	* pwd/getpwnam.c: Likewise.
	* pwd/getpwent.c: Likewise.
	* grp/getgrnam.c: Likewise.
	* grp/getgrgid.c: Likewise.
	* grp/getgrent.c: Likewise.
	* pwd/Makefile (routines): Add getpwent_r, getpwnam_r, getpwuid_r.
	* pwd/getpwent_r.c: New file.
	* pwd/getpwnam_r.c: New file.
	* pwd/getpwuid_r.c: New file.
	* grp/Makefile (routines): Add getgrent_r, getgrgid_r, getgrnam_r.
	* grp/getgrnam_r.c: New file.
	* grp/getgrgid_r.c: New file.
	* grp/getgrent_r.c: New file.
	* grp/Makefile (routines): Remove grpopen, grpread.
	* pwd/Makefile (routines): Remove pwdopen, pwdread.
	* grp/grpopen.c, grp/grpread.c, pwd/pwdopen.c, pwd/pwdread.c: Removed.

	* pwd/fgetpwent.c: Rewritten using files-parse.c.
	* grp/fgetgrent.c: Likewise.

	* nss/Makefile (routines): Add grp-lookup and pwd-lookup.
	* nss/pwd-lookup.c, nss/grp-lookup.c: New files.
	* nss/nss_files/files-grp.c: New file.
	* nss/nss_files/files-pwd.c: New file.

	* nss/Makefile (subdir-dirs): New variable; use it in vpath.

	* nss/nss_files/files-parse.c: New file.
	* nss/nss_files/files-XXX.c: New file.
	* nss/nss_files/files-hosts.c, nss/nss_files/files-proto.c,
	nss/nss_files/files-service.c, nss/nss_files/files-network.c:
	Rewritten using them.

	* nss/Makefile (libnss_files-routines): Remove files-host.
	Add files-hosts, files-grp, files-pwd.

	* nss/nss_dns/dns-network.c: Don't include <pthread.h>.

Mon Jun 24 22:39:12 1996  Richard Henderson  <rth@tamu.edu>

	* sysdeps/alpha/dl-machine.h (ELF_MACHINE_RUNTIME_TRAMPOLINE):
	A .plt entry now loads the .rela.plt offset directly rather
	than making us calculate it.

Sun Jun 23 15:24:05 1996  Roland McGrath  <roland@delasyd.gnu.ai.mit.edu>

	* time/Makefile ($(installed-localtime-file) rule): Do
	$(make-target-directory) first.

	* resolv.h: Fix wrapper for resolv/resolv.h.

	* configure.in (ld --no-whole-archive check): Use AC_TRY_COMMAND.
	Compile dummy file and pass -nostdlib -nostartfiles so as not to
	require installed libraries.

	* shlib-versions (*-*-*): Set libresolv=2, libnss_files=1,
	libnss_dns=1.

Sun Jun 23 19:42:05 1996  Ulrich Drepper  <drepper@cygnus.com>

	* resolv/netdb.h (_PATH_NSSWITCH_CONF): New macro.

	* inet/herrno.c: New file.

	* resolv/res_init.c: Remove res_hconf calls.

	* nss/Makefile, nss/XXX-lookup.c, nss/file-lookup.c,
	nss/getXXbyYY.c, nss/getXXbyYY_r.c, nss/getXXent.c,
	nss/getXXent_r.c, nss/host-lookup.c, nss/network-lookup.c,
	nss/nsswitch.c, nss/nsswitch.h, nss/proto-lookup.c,
	nss/service-lookup.c: New files.  Implementation of name
	service switch, following the approach in Solaris.
	Interface specification and general structure inspired by Peter
	Eriksson <pen@lysator.liu.se>.
	* nss/nss_files/files-host.c, nss/nss_files/files-network.c,
	nss/nss_files/files-proto.c, nss/nss_files/files-service.c:
	Implementation of libnss_files.so module for file based databases
	in NSS service.
	* nss/nss_dns/dns-host.c, nss/nss_dns/dns-network.c: Implementation
        if libnss_dns.so module for DNS name lookup in NSS service.

	* inet/getproto.c, inet/getprtent.c, inet/getprtname.c,
	inet/getservent.c, inet/getsrvbynm.c, inet/getsrvbypt.c:
	Changed to serve as interface to NSS.
	* inet/gethstbyad.c, inet/gethstbyad_r.c, inet/gethstbynm.c,
	inet/gethstbynm2.c, inet/gethstbynm2_r.c, inet/gethstbynm_r.c,
	inet/gethstent.c, inet/gethstent_r.c, inet/getnetbynm.c,
	inet/getnetbynm_r.c, inet/getnetbypt.c, inet/getnetbypt_r.c,
	inet/getnetent.c, inet/getnetent_r.c, inet/getproto_r.c,
	inet/getprtent_r.c, inet/getprtname_r.c, inet/getservent_r.c,
	inet/getsrvbynm_r.c, inet/getsrvbypt_r.c: New files.  Implement
	interfaces to NSS, including reentrant functions.

	* resolv/getnetbyaddr.c, resolv/getnetbyname.c, resolv/getnetent.c,
	resolv/sethostent.c: Removed:  Obsoleted by NSS.

	* resolv/mapv4v6addr.h, resolv/mapv4v6hostent.h: Extracted from
	gethnamaddr.c.  These private functions are now used in more
	than one file.

	* resolv/inet_pton.c, resolv/gethnamaddr.c: Updated to bind-4.9.4-T5B.

Sat Jun 22 16:49:47 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* rpm/Makefile ($(config)): Make sure the word list in the for
	loop is syntactically non-empty.
Diffstat (limited to 'nss/nss_dns')
-rw-r--r--nss/nss_dns/dns-host.c611
-rw-r--r--nss/nss_dns/dns-network.c338
2 files changed, 949 insertions, 0 deletions
diff --git a/nss/nss_dns/dns-host.c b/nss/nss_dns/dns-host.c
new file mode 100644
index 0000000000..eaa9e81218
--- /dev/null
+++ b/nss/nss_dns/dns-host.c
@@ -0,0 +1,611 @@
+/* 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 <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;
+    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;
+      }
+
+  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:
+      errno = EAFNOSUPPORT;
+      *h_errnop = NETDB_INTERNAL;
+      return NSS_STATUS_UNAVAIL;
+    }
+  if (size != len)
+    {
+      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+1];
+  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);
+	  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);
+	  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 (haveanswer)
+	    {
+	      if (n != result->h_length)
+		{
+		  cp += n;
+		  continue;
+		}
+	    }
+	  else
+	    {
+	      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);
+	  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/nss/nss_dns/dns-network.c b/nss/nss_dns/dns-network.c
new file mode 100644
index 0000000000..b714128f1d
--- /dev/null
+++ b/nss/nss_dns/dns-network.c
@@ -0,0 +1,338 @@
+/* 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 int getanswer_r (const querybuf *answer, int anslen,
+			struct netent *result, char *buffer, int buflen,
+			lookup_method net_i);
+
+
+int
+_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 ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+
+  return getanswer_r (&net_buffer, anslen, result, buffer, buflen, BYNAME);
+}
+
+
+int
+_nss_dns_getnetbyaddr_r (long net, int type, struct netent *result,
+			 char *buffer, int buflen)
+{
+  /* Return entry for network with NAME.  */
+  int 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 ? 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 int
+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)
+      {
+	h_errno = HOST_NOT_FOUND;
+	return NSS_STATUS_NOTFOUND;
+      }
+    else
+      {
+	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;
+    }
+
+  /* XXX Really use global variable??? */
+  h_errno = TRY_AGAIN;
+  return NSS_STATUS_TRYAGAIN;
+}