Changes and additions migrated from cvs.devel.redhat.com:/cvs/devel/glibc to fedora-branch

2 files changed, 1061 insertions, 0 deletions

diff --git a/glibc-compat/nss_dns/dns-host.c b/glibc-compat/nss_dns/dns-host.c
new file mode 100644
index 0000000000..5db030cde1
--- /dev/null
+++ b/glibc-compat/nss_dns/dns-host.c
@@ -0,0 +1,641 @@
+/* Copyright (C) 1996, 1997, 1998 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 <glibc-compat/include/netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/syslog.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 > 65536
+# define MAXPACKET	PACKETSZ
+#else
+# define MAXPACKET	65536
+#endif
+/* As per RFC 1034 and 1035 a host name cannot exceed 255 octets in length.  */
+#ifdef MAXHOSTNAMELEN
+# undef MAXHOSTNAMELEN
+#endif
+#define MAXHOSTNAMELEN 256
+
+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,
+				    size_t buflen, int *h_errnop);
+
+enum nss_status
+_nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
+			   char *buffer, size_t buflen, int *h_errnop)
+{
+  union
+    {
+      querybuf *buf;
+      u_char *ptr;
+    } host_buffer;
+  querybuf *orig_host_buffer;
+  int size, type, n;
+  const char *cp;
+  enum nss_status status;
+
+  if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+    {
+      *h_errnop = NETDB_INTERNAL;
+      return NSS_STATUS_UNAVAIL;
+    }
+
+  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;
+
+  host_buffer.buf = orig_host_buffer = (querybuf *) alloca (1024);
+
+  n = __libc_res_nsearch (&_res, name, C_IN, type, host_buffer.buf->buf, 1024,
+			  &host_buffer.ptr);
+  if (n < 0)
+    {
+      *h_errnop = h_errno;
+      if (host_buffer.buf != orig_host_buffer)
+	free (host_buffer.buf);
+      return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+    }
+
+  status = getanswer_r (host_buffer.buf, n, name, type, result, buffer, buflen,
+			h_errnop);
+  if (host_buffer.buf != orig_host_buffer)
+    free (host_buffer.buf);
+  return status;
+}
+
+
+enum nss_status
+_nss_dns_gethostbyname_r (const char *name, struct hostent *result,
+			  char *buffer, size_t 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, size_t 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;
+  union
+    {
+      querybuf *buf;
+      u_char *ptr;
+    } host_buffer;
+  querybuf *orig_host_buffer;
+  char qbuf[MAXDNAME+1], *qp;
+  int size, n, status;
+
+  if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+    {
+      *h_errnop = NETDB_INTERNAL;
+      return NSS_STATUS_UNAVAIL;
+    }
+
+  if (af == AF_INET6 && len == IN6ADDRSZ &&
+      (memcmp (uaddr, mapped, sizeof mapped) == 0
+       || memcmp (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.  */
+      break;
+    }
+
+  host_buffer.buf = orig_host_buffer = (querybuf *) alloca (1024);
+
+  n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
+			 1024, &host_buffer.ptr);
+  if (n < 0)
+    {
+      *h_errnop = h_errno;
+      if (host_buffer.buf != orig_host_buffer)
+	free (host_buffer.buf);
+      return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+    }
+
+  status = getanswer_r (host_buffer.buf, n, qbuf, T_PTR, result, buffer, buflen,
+			h_errnop);
+  if (host_buffer.buf != orig_host_buffer)
+    free (host_buffer.buf);
+  if (status != NSS_STATUS_SUCCESS)
+    {
+      *h_errnop = h_errno;
+      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;
+  memcpy (host_data->host_addr, 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, size_t 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) (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 */
+      if (n >= MAXHOSTNAMELEN)
+	{
+	  __set_h_errno (NO_RECOVERY);
+	  return NSS_STATUS_TRYAGAIN;
+	}
+      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.  */
+	  if (n >= MAXHOSTNAMELEN)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  bp += n;
+	  linebuflen -= n;
+	  /* Get canonical name.  */
+	  n = strlen (tbuf) + 1;	/* For the \0.  */
+	  if ((size_t) n > linebuflen || n >= MAXHOSTNAMELEN)
+	    {
+	      ++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_dnok (tbuf) == 0)
+	    {
+	      ++had_error;
+	      continue;
+	    }
+	  cp += n;
+	  /* Get canonical name. */
+	  n = strlen (tbuf) + 1;   /* For the \0.  */
+	  if ((size_t) n > linebuflen || n >= MAXHOSTNAMELEN)
+	    {
+	      ++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 */
+	      if (n >= MAXHOSTNAMELEN)
+		{
+		  ++had_error;
+		  break;
+		}
+	      bp += n;
+	      linebuflen -= n;
+	    }
+	  break;
+#else
+	  result->h_name = bp;
+	  if (_res.options & RES_USE_INET6)
+	    {
+	      n = strlen (bp) + 1;	/* for the \0 */
+	      if (n >= MAXHOSTNAMELEN)
+		{
+		  ++had_error;
+		  break;
+		}
+	      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;
+	    }
+
+	  linebuflen -= sizeof (align) - ((u_long) bp % sizeof (align));
+	  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;
+	    }
+	  memcpy (*hap++ = bp, cp, 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 || n >= MAXHOSTNAMELEN)
+	    goto no_recovery;
+	  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;
+    }
+ no_recovery:
+  *h_errnop = NO_RECOVERY;
+  return NSS_STATUS_TRYAGAIN;
+}
diff --git a/glibc-compat/nss_dns/dns-network.c b/glibc-compat/nss_dns/dns-network.c
new file mode 100644
index 0000000000..b6c7a4fdc9
--- /dev/null
+++ b/glibc-compat/nss_dns/dns-network.c
@@ -0,0 +1,420 @@
+/* Copyright (C) 1996, 1997 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 <glibc-compat/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 > 65536
+#define MAXPACKET       PACKETSZ
+#else
+#define MAXPACKET       65536
+#endif
+
+
+typedef enum
+{
+  BYADDR,
+  BYNAME
+} lookup_method;
+
+
+/* We need this time later.  */
+typedef union querybuf
+{
+  HEADER hdr;
+  u_char buf[MAXPACKET];
+} querybuf;
+
+
+/* Prototypes for local functions.  */
+static enum nss_status getanswer_r (const querybuf *answer, int anslen,
+				    struct netent *result, char *buffer,
+				    size_t buflen, lookup_method net_i);
+
+
+enum nss_status
+_nss_dns_getnetbyname_r (const char *name, struct netent *result,
+			 char *buffer, size_t buflen)
+{
+  /* Return entry for network with NAME.  */
+  union
+  {
+    querybuf *buf;
+    u_char *ptr;
+  } net_buffer;
+  querybuf *orig_net_buffer;
+  int anslen;
+  char *qbuf;
+  enum nss_status status;
+
+  if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+    return NSS_STATUS_UNAVAIL;
+
+  qbuf = strdupa (name);
+
+  net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
+
+  anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
+			       1024, &net_buffer.ptr);
+  if (anslen < 0)
+    {
+      if (net_buffer.buf != orig_net_buffer)
+	free (net_buffer.buf);
+      /* Nothing found.  */
+      return (errno == ECONNREFUSED
+	      || errno == EPFNOSUPPORT
+	      || errno == EAFNOSUPPORT)
+	      ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+    }
+
+  status = getanswer_r (net_buffer.buf, anslen, result, buffer, buflen, BYNAME);
+  if (net_buffer.buf != orig_net_buffer)
+    free (net_buffer.buf);
+  return status;
+}
+
+
+enum nss_status
+_nss_dns_getnetbyaddr_r (long net, int type, struct netent *result,
+			 char *buffer, size_t buflen)
+{
+  /* Return entry for network with NAME.  */
+  enum nss_status status;
+  union
+  {
+    querybuf *buf;
+    u_char *ptr;
+  } net_buffer;
+  querybuf *orig_net_buffer;
+  unsigned int net_bytes[4];
+  char qbuf[MAXDNAME];
+  int cnt, anslen;
+  u_int32_t net2;
+
+  if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+    return NSS_STATUS_UNAVAIL;
+
+  /* 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;
+    }
+
+  net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
+
+  anslen = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
+			      1024, &net_buffer.ptr);
+  if (anslen < 0)
+    {
+      if (net_buffer.buf != orig_net_buffer)
+	free (net_buffer.buf);
+      /* Nothing found.  */
+      return (errno == ECONNREFUSED
+	      || errno == EPFNOSUPPORT
+	      || errno == EAFNOSUPPORT)
+	      ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
+    }
+
+  status = getanswer_r (net_buffer.buf, anslen, result, buffer, buflen, BYADDR);
+  if (net_buffer.buf != orig_net_buffer)
+    free (net_buffer.buf);
+  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, size_t 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)
+    {
+      int n = __dn_skipname (cp, end_of_message);
+      if (n < 0 || end_of_message - (cp + n) < QFIXEDSZ)
+       {
+         __set_h_errno (NO_RECOVERY);
+         return NSS_STATUS_UNAVAIL;
+       }
+      cp += n + 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;
+         if (alias_pointer + 2 < &net_data->aliases[MAX_NR_ALIASES])
+           {
+             *alias_pointer++ = bp;
+             n = strlen (bp) + 1;
+             bp += n;
+             linebuflen -= n;
+             result->n_addrtype = class == C_IN ? AF_INET : AF_UNSPEC;
+             ++have_answer;
+           }
+	}
+    }
+
+  if (have_answer)
+    {
+      *alias_pointer = NULL;
+      switch (net_i)
+	{
+	case BYADDR:
+	  result->n_name = *result->n_aliases++;
+	  result->n_net = 0L;
+	  return NSS_STATUS_SUCCESS;
+
+	case BYNAME:
+	  {
+	    char **ap = result->n_aliases++;
+	    while (*ap != NULL)
+	      {
+		/* Check each alias name for being of the forms:
+		   4.3.2.1.in-addr.arpa		= net 1.2.3.4
+		   3.2.1.in-addr.arpa		= net 0.1.2.3
+		   2.1.in-addr.arpa		= net 0.0.1.2
+		   1.in-addr.arpa		= net 0.0.0.1
+		*/
+		uint32_t val = 0;	/* Accumulator for n_net value.  */
+		unsigned int shift = 0; /* Which part we are parsing now.  */
+		const char *p = *ap; /* Consuming the string.  */
+		do
+		  {
+		    /* Match the leading 0 or 0[xX] base indicator.  */
+		    unsigned int base = 10;
+		    if (*p == '0' && p[1] != '.')
+		      {
+			base = 8;
+			++p;
+			if (*p == 'x' || *p == 'X')
+			  {
+			    base = 16;
+			    ++p;
+			    if (*p == '.')
+			      break; /* No digit here.  Give up on alias.  */
+			  }
+			if (*p == '\0')
+			  break;
+		      }
+
+		    uint32_t part = 0; /* Accumulates this part's number.  */
+		    do
+		      {
+			if (isdigit (*p) && (*p - '0' < base))
+			  part = (part * base) + (*p - '0');
+			else if (base == 16 && isxdigit (*p))
+			  part = (part << 4) + 10 + (tolower (*p) - 'a');
+			++p;
+		      } while (*p != '\0' && *p != '.');
+
+		    if (*p != '.')
+		      break;	/* Bad form.  Give up on this name.  */
+
+		    /* Install this as the next more significant byte.  */
+		    val |= part << shift;
+		    shift += 8;
+		    ++p;
+
+		    /* If we are out of digits now, there are two cases:
+		       1. We are done with digits and now see "in-addr.arpa".
+		       2. This is not the droid we are looking for.  */
+		    if (!isdigit (*p) && !strcasecmp (p, "in-addr.arpa"))
+		      {
+			result->n_net = val;
+			return NSS_STATUS_SUCCESS;
+		      }
+
+		    /* Keep going when we have seen fewer than 4 parts.  */
+		  } while (shift < 32);
+	      }
+	  }
+	  break;
+	}
+    }
+
+  __set_h_errno (TRY_AGAIN);
+  return NSS_STATUS_TRYAGAIN;
+}