[thirdparty/glibc.git] / resolv / nss_dns / dns-network.c

/* Copyright (C) 1996-2012 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/* 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.
 * 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 > 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;

/* These functions are defined in res_comp.c.  */
#define NS_MAXCDNAME	255	/* maximum compressed domain name */
extern int __ns_name_ntop (const u_char *, char *, size_t) __THROW;
extern int __ns_name_unpack (const u_char *, const u_char *,
			     const u_char *, u_char *, size_t) __THROW;


/* Prototypes for local functions.  */
static enum nss_status getanswer_r (const querybuf *answer, int anslen,
				    struct netent *result, char *buffer,
				    size_t buflen, int *errnop, int *h_errnop,
				    lookup_method net_i);


enum nss_status
_nss_dns_getnetbyname_r (const char *name, struct netent *result,
			 char *buffer, size_t buflen, int *errnop,
			 int *herrnop)
{
  /* 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_maybe_init (&_res, 0) == -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, NULL, NULL, NULL);
  if (anslen < 0)
    {
      /* Nothing found.  */
      *errnop = errno;
      if (net_buffer.buf != orig_net_buffer)
	free (net_buffer.buf);
      return (errno == ECONNREFUSED
	      || errno == EPFNOSUPPORT
	      || errno == EAFNOSUPPORT)
	? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
    }

  status = getanswer_r (net_buffer.buf, anslen, result, buffer, buflen,
			errnop, herrnop, BYNAME);
  if (net_buffer.buf != orig_net_buffer)
    free (net_buffer.buf);
  return status;
}


enum nss_status
_nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
			 char *buffer, size_t buflen, int *errnop,
			 int *herrnop)
{
  /* 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;
  int olderr = errno;

  /* No net address lookup for IPv6 yet.  */
  if (type != AF_INET)
    return NSS_STATUS_UNAVAIL;

  if (__res_maybe_init (&_res, 0) == -1)
    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, NULL, NULL, NULL);
  if (anslen < 0)
    {
      /* Nothing found.  */
      int err = errno;
      __set_errno (olderr);
      if (net_buffer.buf != orig_net_buffer)
	free (net_buffer.buf);
      return (err == ECONNREFUSED
	      || err == EPFNOSUPPORT
	      || err == EAFNOSUPPORT)
	? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
    }

  status = getanswer_r (net_buffer.buf, anslen, result, buffer, buflen,
			errnop, herrnop, 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, int *errnop, int *h_errnop,
	     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;

  uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct net_data);
  buffer += pad;

  if (__builtin_expect (buflen < sizeof (*net_data) + pad, 0))
    {
      /* The buffer is too small.  */
    too_small:
      *errnop = ERANGE;
      *h_errnop = NETDB_INTERNAL;
      return NSS_STATUS_TRYAGAIN;
    }
  buflen -= pad;

  net_data = (struct net_data *) buffer;
  int linebuflen = buflen - offsetof (struct net_data, linebuffer);
  if (buflen - offsetof (struct net_data, linebuffer) != linebuflen)
    linebuflen = INT_MAX;
  const unsigned 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 unsigned char *cp = &answer->buf[HFIXEDSZ];
  char **alias_pointer;
  int have_answer;
  u_char packtmp[NS_MAXCDNAME];

  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;

  while (--answer_count >= 0 && cp < end_of_message)
    {
      int n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
      int type, class;

      n = __ns_name_unpack (answer->buf, end_of_message, cp,
			    packtmp, sizeof packtmp);
      if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
	{
	  if (errno == EMSGSIZE)
	    goto too_small;

	  n = -1;
	}

      if (n > 0 && bp[0] == '.')
	bp[0] = '\0';

      if (n < 0 || res_dnok (bp) == 0)
	break;
      cp += n;
      GETSHORT (type, cp);
      GETSHORT (class, cp);
      cp += INT32SZ;		/* TTL */
      GETSHORT (n, cp);

      if (class == C_IN && type == T_PTR)
	{
	  n = __ns_name_unpack (answer->buf, end_of_message, cp,
				packtmp, sizeof packtmp);
	  if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
	    {
	      if (errno == EMSGSIZE)
		goto too_small;

	      n = -1;
	    }

	  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;
}
Commit	Line	Data
f4cf5f2d	1	/* Copyright (C) 1996-2012 Free Software Foundation, Inc.
84384f5b UD	2	This file is part of the GNU C Library.
84384f5b UD	3	Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
5f0e6fc7	4
84384f5b	5	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
5f0e6fc7	9
84384f5b UD	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	13	Lesser General Public License for more details.
5f0e6fc7	14
41bdb6e2	15	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	16	License along with the GNU C Library; if not, see
59ba27a6 PE	17	<http://www.gnu.org/licenses/>. */
5f0e6fc7 RM	18
	19	/* Parts of this file are plain copies of the file `getnetnamadr.c' from
	20	the bind package and it has the following copyright. */
	21
	22	/* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
	23	* Dep. Matematica Universidade de Coimbra, Portugal, Europe
	24	*
	25	* Permission to use, copy, modify, and distribute this software for any
	26	* purpose with or without fee is hereby granted, provided that the above
	27	* copyright notice and this permission notice appear in all copies.
	28	*/
	29	/*
	30	* Copyright (c) 1983, 1993
	31	* The Regents of the University of California. All rights reserved.
	32	*
	33	* Redistribution and use in source and binary forms, with or without
	34	* modification, are permitted provided that the following conditions
	35	* are met:
	36	* 1. Redistributions of source code must retain the above copyright
	37	* notice, this list of conditions and the following disclaimer.
	38	* 2. Redistributions in binary form must reproduce the above copyright
	39	* notice, this list of conditions and the following disclaimer in the
	40	* documentation and/or other materials provided with the distribution.
5f0e6fc7 RM	41	* 4. Neither the name of the University nor the names of its contributors
	42	* may be used to endorse or promote products derived from this software
	43	* without specific prior written permission.
	44	*
	45	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	46	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	47	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	48	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	49	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	50	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	51	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	52	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	53	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	54	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	55	* SUCH DAMAGE.
	56	*/
	57
	58	#include <ctype.h>
	59	#include <errno.h>
	60	#include <netdb.h>
	61	#include <stdio.h>
	62	#include <stdlib.h>
	63	#include <string.h>
	64
	65	#include "nsswitch.h"
	66	#include <arpa/inet.h>
	67
	68	/* Maximum number of aliases we allow. */
	69	#define MAX_NR_ALIASES 48
	70
	71
870d19de RM	72	#if PACKETSZ > 65536
870d19de RM	73	# define MAXPACKET PACKETSZ
5f0e6fc7	74	#else
870d19de	75	# define MAXPACKET 65536
5f0e6fc7 RM	76	#endif
	77
	78
	79	typedef enum
	80	{
	81	BYADDR,
	82	BYNAME
	83	} lookup_method;
	84
	85
	86	/* We need this time later. */
	87	typedef union querybuf
	88	{
	89	HEADER hdr;
	90	u_char buf[MAXPACKET];
	91	} querybuf;
	92
8d8c6efa UD	93	/* These functions are defined in res_comp.c. */
8d8c6efa UD	94	#define NS_MAXCDNAME 255 /* maximum compressed domain name */
79937577 UD	95	extern int __ns_name_ntop (const u_char , char , size_t) __THROW;
	96	extern int __ns_name_unpack (const u_char , const u_char ,
	97	const u_char , u_char , size_t) __THROW;
8d8c6efa	98
5f0e6fc7	99
6d52618b	100	/* Prototypes for local functions. */
84384f5b UD	101	static enum nss_status getanswer_r (const querybuf *answer, int anslen,
84384f5b UD	102	struct netent result, char buffer,
2f1687b9 UD	103	size_t buflen, int errnop, int h_errnop,
2f1687b9 UD	104	lookup_method net_i);
5f0e6fc7 RM	105
5f0e6fc7 RM	106
84384f5b	107	enum nss_status
5f0e6fc7	108	_nss_dns_getnetbyname_r (const char name, struct netent result,
51eecc4a AJ	109	char buffer, size_t buflen, int errnop,
51eecc4a AJ	110	int *herrnop)
5f0e6fc7 RM	111	{
5f0e6fc7 RM	112	/* Return entry for network with NAME. */
16b66062 AJ	113	union
	114	{
	115	querybuf *buf;
	116	u_char *ptr;
	117	} net_buffer;
	118	querybuf *orig_net_buffer;
0420d888	119	int anslen;
5f0e6fc7	120	char *qbuf;
6166815d	121	enum nss_status status;
5f0e6fc7	122
87bb6b6c	123	if (__res_maybe_init (&_res, 0) == -1)
b43b13ac UD	124	return NSS_STATUS_UNAVAIL;
b43b13ac UD	125
5f0e6fc7	126	qbuf = strdupa (name);
6166815d	127
16b66062	128	net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
6166815d	129
16b66062	130	anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
b7da31a1	131	1024, &net_buffer.ptr, NULL, NULL, NULL);
5f0e6fc7	132	if (anslen < 0)
67479a70 UD	133	{
	134	/* Nothing found. */
	135	*errnop = errno;
16b66062 AJ	136	if (net_buffer.buf != orig_net_buffer)
16b66062 AJ	137	free (net_buffer.buf);
67479a70 UD	138	return (errno == ECONNREFUSED
	139	\|\| errno == EPFNOSUPPORT
	140	\|\| errno == EAFNOSUPPORT)
	141	? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
	142	}
5f0e6fc7	143
2f1687b9 UD	144	status = getanswer_r (net_buffer.buf, anslen, result, buffer, buflen,
2f1687b9 UD	145	errnop, herrnop, BYNAME);
16b66062 AJ	146	if (net_buffer.buf != orig_net_buffer)
16b66062 AJ	147	free (net_buffer.buf);
6166815d	148	return status;
5f0e6fc7 RM	149	}
	150
	151
84384f5b	152	enum nss_status
51eecc4a AJ	153	_nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
	154	char buffer, size_t buflen, int errnop,
	155	int *herrnop)
5f0e6fc7 RM	156	{
5f0e6fc7 RM	157	/* Return entry for network with NAME. */
84384f5b	158	enum nss_status status;
16b66062 AJ	159	union
	160	{
	161	querybuf *buf;
	162	u_char *ptr;
	163	} net_buffer;
	164	querybuf *orig_net_buffer;
5f0e6fc7 RM	165	unsigned int net_bytes[4];
5f0e6fc7 RM	166	char qbuf[MAXDNAME];
0420d888	167	int cnt, anslen;
5f0e6fc7	168	u_int32_t net2;
34816665	169	int olderr = errno;
5f0e6fc7 RM	170
	171	/* No net address lookup for IPv6 yet. */
	172	if (type != AF_INET)
	173	return NSS_STATUS_UNAVAIL;
	174
87bb6b6c	175	if (__res_maybe_init (&_res, 0) == -1)
b43b13ac	176	return NSS_STATUS_UNAVAIL;
51eecc4a	177
5f0e6fc7 RM	178	net2 = (u_int32_t) net;
	179	for (cnt = 4; net2 != 0; net2 >>= 8)
	180	net_bytes[--cnt] = net2 & 0xff;
	181
	182	switch (cnt)
	183	{
	184	case 3:
	185	/* Class A network. */
	186	sprintf (qbuf, "0.0.0.%u.in-addr.arpa", net_bytes[3]);
	187	break;
	188	case 2:
	189	/* Class B network. */
	190	sprintf (qbuf, "0.0.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2]);
	191	break;
	192	case 1:
	193	/* Class C network. */
	194	sprintf (qbuf, "0.%u.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2],
	195	net_bytes[1]);
	196	break;
	197	case 0:
	198	/* Class D - E network. */
	199	sprintf (qbuf, "%u.%u.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2],
	200	net_bytes[1], net_bytes[0]);
	201	break;
	202	}
	203
16b66062	204	net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
6166815d	205
16b66062	206	anslen = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
b7da31a1	207	1024, &net_buffer.ptr, NULL, NULL, NULL);
5f0e6fc7	208	if (anslen < 0)
67479a70 UD	209	{
67479a70 UD	210	/* Nothing found. */
34816665 UD	211	int err = errno;
34816665 UD	212	__set_errno (olderr);
16b66062 AJ	213	if (net_buffer.buf != orig_net_buffer)
16b66062 AJ	214	free (net_buffer.buf);
34816665 UD	215	return (err == ECONNREFUSED
	216	\|\| err == EPFNOSUPPORT
	217	\|\| err == EAFNOSUPPORT)
67479a70 UD	218	? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
67479a70 UD	219	}
5f0e6fc7	220
2f1687b9 UD	221	status = getanswer_r (net_buffer.buf, anslen, result, buffer, buflen,
2f1687b9 UD	222	errnop, herrnop, BYADDR);
16b66062 AJ	223	if (net_buffer.buf != orig_net_buffer)
16b66062 AJ	224	free (net_buffer.buf);
5f0e6fc7 RM	225	if (status == NSS_STATUS_SUCCESS)
	226	{
	227	/* Strip trailing zeros. */
	228	unsigned int u_net = net; /* Maybe net should be unsigned? */
	229
	230	while ((u_net & 0xff) == 0 && u_net != 0)
	231	u_net >>= 8;
	232	result->n_net = u_net;
	233	}
	234
	235	return status;
	236	}
	237
	238
	239	#undef offsetof
	240	#define offsetof(Type, Member) ((size_t) &((Type *) NULL)->Member)
	241
84384f5b	242	static enum nss_status
5f0e6fc7	243	getanswer_r (const querybuf answer, int anslen, struct netent result,
2f1687b9 UD	244	char buffer, size_t buflen, int errnop, int *h_errnop,
2f1687b9 UD	245	lookup_method net_i)
5f0e6fc7 RM	246	{
	247	/*
	248	* Find first satisfactory answer
	249	*
	250	* answer --> +------------+ ( MESSAGE )
	251	* \| Header \|
	252	* +------------+
	253	* \| Question \| the question for the name server
	254	* +------------+
	255	* \| Answer \| RRs answering the question
	256	* +------------+
	257	* \| Authority \| RRs pointing toward an authority
	258	* \| Additional \| RRs holding additional information
	259	* +------------+
	260	*/
	261	struct net_data
	262	{
	263	char *aliases[MAX_NR_ALIASES];
	264	char linebuffer[0];
2f1687b9 UD	265	} *net_data;
	266
	267	uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct net_data);
	268	buffer += pad;
	269
	270	if (__builtin_expect (buflen < sizeof (*net_data) + pad, 0))
	271	{
	272	/* The buffer is too small. */
	273	too_small:
	274	*errnop = ERANGE;
	275	*h_errnop = NETDB_INTERNAL;
	276	return NSS_STATUS_TRYAGAIN;
	277	}
	278	buflen -= pad;
	279
	280	net_data = (struct net_data *) buffer;
5f0e6fc7	281	int linebuflen = buflen - offsetof (struct net_data, linebuffer);
2f1687b9 UD	282	if (buflen - offsetof (struct net_data, linebuffer) != linebuflen)
2f1687b9 UD	283	linebuflen = INT_MAX;
9cfe5381	284	const unsigned char *end_of_message = &answer->buf[anslen];
5f0e6fc7 RM	285	const HEADER *header_pointer = &answer->hdr;
	286	/* #/records in the answer section. */
	287	int answer_count = ntohs (header_pointer->ancount);
	288	/* #/entries in the question section. */
	289	int question_count = ntohs (header_pointer->qdcount);
	290	char *bp = net_data->linebuffer;
9cfe5381	291	const unsigned char *cp = &answer->buf[HFIXEDSZ];
5f0e6fc7 RM	292	char **alias_pointer;
5f0e6fc7 RM	293	int have_answer;
8d8c6efa	294	u_char packtmp[NS_MAXCDNAME];
5f0e6fc7 RM	295
5f0e6fc7 RM	296	if (question_count == 0)
7ef90c15 UD	297	{
	298	/* FIXME: the Sun version uses for host name lookup an additional
	299	parameter for pointing to h_errno. this is missing here.
	300	OSF/1 has a per-thread h_errno variable. */
	301	if (header_pointer->aa != 0)
	302	{
	303	__set_h_errno (HOST_NOT_FOUND);
	304	return NSS_STATUS_NOTFOUND;
	305	}
	306	else
	307	{
	308	__set_h_errno (TRY_AGAIN);
	309	return NSS_STATUS_TRYAGAIN;
	310	}
	311	}
5f0e6fc7 RM	312
	313	/* Skip the question part. */
	314	while (question_count-- > 0)
9b57c1c1 RM	315	{
	316	int n = __dn_skipname (cp, end_of_message);
	317	if (n < 0 \|\| end_of_message - (cp + n) < QFIXEDSZ)
	318	{
	319	__set_h_errno (NO_RECOVERY);
	320	return NSS_STATUS_UNAVAIL;
	321	}
	322	cp += n + QFIXEDSZ;
	323	}
5f0e6fc7 RM	324
	325	alias_pointer = result->n_aliases = &net_data->aliases[0];
	326	*alias_pointer = NULL;
	327	have_answer = 0;
5f0e6fc7 RM	328
	329	while (--answer_count >= 0 && cp < end_of_message)
	330	{
	331	int n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
	332	int type, class;
	333
8d8c6efa UD	334	n = __ns_name_unpack (answer->buf, end_of_message, cp,
	335	packtmp, sizeof packtmp);
	336	if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
	337	{
	338	if (errno == EMSGSIZE)
2f1687b9	339	goto too_small;
8d8c6efa UD	340
	341	n = -1;
	342	}
	343
	344	if (n > 0 && bp[0] == '.')
	345	bp[0] = '\0';
	346
5f0e6fc7 RM	347	if (n < 0 \|\| res_dnok (bp) == 0)
	348	break;
	349	cp += n;
5f0e6fc7 RM	350	GETSHORT (type, cp);
	351	GETSHORT (class, cp);
	352	cp += INT32SZ; /* TTL */
	353	GETSHORT (n, cp);
	354
	355	if (class == C_IN && type == T_PTR)
	356	{
8d8c6efa UD	357	n = __ns_name_unpack (answer->buf, end_of_message, cp,
	358	packtmp, sizeof packtmp);
	359	if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
	360	{
	361	if (errno == EMSGSIZE)
2f1687b9	362	goto too_small;
8d8c6efa UD	363
	364	n = -1;
	365	}
	366
5f0e6fc7 RM	367	if (n < 0 \|\| !res_hnok (bp))
	368	{
	369	/* XXX What does this mean? The original form from bind
	370	returns NULL. Incrementing cp has no effect in any case.
	371	What should I return here. ??? */
	372	cp += n;
	373	return NSS_STATUS_UNAVAIL;
	374	}
	375	cp += n;
9b57c1c1 RM	376	if (alias_pointer + 2 < &net_data->aliases[MAX_NR_ALIASES])
	377	{
	378	*alias_pointer++ = bp;
	379	n = strlen (bp) + 1;
	380	bp += n;
	381	linebuflen -= n;
	382	result->n_addrtype = class == C_IN ? AF_INET : AF_UNSPEC;
	383	++have_answer;
	384	}
5f0e6fc7 RM	385	}
	386	}
	387
	388	if (have_answer)
	389	{
5f0e6fc7 RM	390	*alias_pointer = NULL;
	391	switch (net_i)
	392	{
	393	case BYADDR:
0bf5c050	394	result->n_name = *result->n_aliases++;
5f0e6fc7	395	result->n_net = 0L;
0bf5c050	396	return NSS_STATUS_SUCCESS;
5f0e6fc7	397
0bf5c050 RM	398	case BYNAME:
	399	{
	400	char **ap = result->n_aliases++;
	401	while (*ap != NULL)
	402	{
	403	/* Check each alias name for being of the forms:
	404	4.3.2.1.in-addr.arpa = net 1.2.3.4
	405	3.2.1.in-addr.arpa = net 0.1.2.3
	406	2.1.in-addr.arpa = net 0.0.1.2
	407	1.in-addr.arpa = net 0.0.0.1
	408	*/
	409	uint32_t val = 0; /* Accumulator for n_net value. */
	410	unsigned int shift = 0; /* Which part we are parsing now. */
	411	const char p = ap; /* Consuming the string. */
	412	do
	413	{
	414	/* Match the leading 0 or 0[xX] base indicator. */
	415	unsigned int base = 10;
	416	if (*p == '0' && p[1] != '.')
	417	{
	418	base = 8;
	419	++p;
	420	if (p == 'x' \|\| p == 'X')
	421	{
	422	base = 16;
	423	++p;
	424	if (*p == '.')
	425	break; /* No digit here. Give up on alias. */
	426	}
	427	if (*p == '\0')
	428	break;
	429	}
	430
	431	uint32_t part = 0; /* Accumulates this part's number. */
	432	do
	433	{
	434	if (isdigit (p) && (p - '0' < base))
	435	part = (part * base) + (*p - '0');
	436	else if (base == 16 && isxdigit (*p))
	437	part = (part << 4) + 10 + (tolower (*p) - 'a');
	438	++p;
	439	} while (p != '\0' && p != '.');
	440
	441	if (*p != '.')
	442	break; /* Bad form. Give up on this name. */
	443
	444	/* Install this as the next more significant byte. */
	445	val \|= part << shift;
	446	shift += 8;
	447	++p;
	448
	449	/* If we are out of digits now, there are two cases:
	450	1. We are done with digits and now see "in-addr.arpa".
	451	2. This is not the droid we are looking for. */
	452	if (!isdigit (*p) && !strcasecmp (p, "in-addr.arpa"))
	453	{
	454	result->n_net = val;
	455	return NSS_STATUS_SUCCESS;
	456	}
	457
	458	/* Keep going when we have seen fewer than 4 parts. */
	459	} while (shift < 32);
	460	}
	461	}
5f0e6fc7 RM	462	break;
5f0e6fc7 RM	463	}
5f0e6fc7 RM	464	}
5f0e6fc7 RM	465
a68b0d31	466	__set_h_errno (TRY_AGAIN);
5f0e6fc7 RM	467	return NSS_STATUS_TRYAGAIN;
5f0e6fc7 RM	468	}