[thirdparty/glibc.git] / nscd / nscd_gethst_r.c

/* Copyright (C) 1998-2005, 2006, 2007 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.

   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <assert.h>
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/nameser.h>
#include <not-cancel.h>

#include "nscd-client.h"
#include "nscd_proto.h"

int __nss_not_use_nscd_hosts;

static int nscd_gethst_r (const char *key, size_t keylen, request_type type,
			  struct hostent *resultbuf, char *buffer,
			  size_t buflen, struct hostent **result,
			  int *h_errnop) internal_function;


int
__nscd_gethostbyname_r (const char *name, struct hostent *resultbuf,
			char *buffer, size_t buflen, struct hostent **result,
			int *h_errnop)
{
  request_type reqtype;

  reqtype = (_res.options & RES_USE_INET6) ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;

  return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
			buffer, buflen, result, h_errnop);
}


int
__nscd_gethostbyname2_r (const char *name, int af, struct hostent *resultbuf,
			 char *buffer, size_t buflen, struct hostent **result,
			 int *h_errnop)
{
  request_type reqtype;

  reqtype = af == AF_INET6 ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;

  return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
			buffer, buflen, result, h_errnop);
}


int
__nscd_gethostbyaddr_r (const void *addr, socklen_t len, int type,
			struct hostent *resultbuf, char *buffer, size_t buflen,
			struct hostent **result, int *h_errnop)
{
  request_type reqtype;

  if (!((len == INADDRSZ && type == AF_INET)
	|| (len == IN6ADDRSZ && type == AF_INET6)))
    /* LEN and TYPE do not match.  */
    return -1;

  reqtype = type == AF_INET6 ? GETHOSTBYADDRv6 : GETHOSTBYADDR;

  return nscd_gethst_r (addr, len, reqtype, resultbuf, buffer, buflen, result,
			h_errnop);
}


libc_locked_map_ptr (, __hst_map_handle) attribute_hidden;
/* Note that we only free the structure if necessary.  The memory
   mapping is not removed since it is not visible to the malloc
   handling.  */
libc_freeres_fn (hst_map_free)
{
  if (__hst_map_handle.mapped != NO_MAPPING)
    {
      void *p = __hst_map_handle.mapped;
      __hst_map_handle.mapped = NO_MAPPING;
      free (p);
    }
}


static int
internal_function
nscd_gethst_r (const char *key, size_t keylen, request_type type,
	       struct hostent *resultbuf, char *buffer, size_t buflen,
	       struct hostent **result, int *h_errnop)
{
  int gc_cycle;
  int nretries = 0;

  /* If the mapping is available, try to search there instead of
     communicating with the nscd.  */
  struct mapped_database *mapped;
  mapped = __nscd_get_map_ref (GETFDHST, "hosts", &__hst_map_handle,
			       &gc_cycle);

 retry:;
  const char *h_name = NULL;
  const uint32_t *aliases_len = NULL;
  const char *addr_list = NULL;
  size_t addr_list_len = 0;
  int retval = -1;
  const char *recend = (const char *) ~UINTMAX_C (0);
  int sock = -1;
  hst_response_header hst_resp;
  if (mapped != NO_MAPPING)
    {
      /* No const qualifier, as it can change during garbage collection.  */
      struct datahead *found = __nscd_cache_search (type, key, keylen, mapped);
      if (found != NULL)
	{
	  h_name = (char *) (&found->data[0].hstdata + 1);
	  hst_resp = found->data[0].hstdata;
	  aliases_len = (uint32_t *) (h_name + hst_resp.h_name_len);
	  addr_list = ((char *) aliases_len
		       + hst_resp.h_aliases_cnt * sizeof (uint32_t));
	  addr_list_len = hst_resp.h_addr_list_cnt * INADDRSZ;
	  recend = (const char *) found->data + found->recsize;
	  /* Now check if we can trust hst_resp fields.  If GC is
	     in progress, it can contain anything.  */
	  if (mapped->head->gc_cycle != gc_cycle)
	    {
	      retval = -2;
	      goto out;
	    }

#ifndef _STRING_ARCH_unaligned
	  /* The aliases_len array in the mapped database might very
	     well be unaligned.  We will access it word-wise so on
	     platforms which do not tolerate unaligned accesses we
	     need to make an aligned copy.  */
	  if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1))
	      != 0)
	    {
	      uint32_t *tmp = alloca (hst_resp.h_aliases_cnt
				      * sizeof (uint32_t));
	      aliases_len = memcpy (tmp, aliases_len,
				    hst_resp.h_aliases_cnt
				    * sizeof (uint32_t));
	    }
#endif
	  if (type != GETHOSTBYADDR && type != GETHOSTBYNAME)
	    {
	      if (hst_resp.h_length == INADDRSZ)
		addr_list += addr_list_len;
	      addr_list_len = hst_resp.h_addr_list_cnt * IN6ADDRSZ;
	    }
	  if (__builtin_expect ((const char *) addr_list + addr_list_len
				> recend, 0))
	    goto out;
	}
    }

  if (h_name == NULL)
    {
      sock = __nscd_open_socket (key, keylen, type, &hst_resp,
				 sizeof (hst_resp));
      if (sock == -1)
	{
	  __nss_not_use_nscd_hosts = 1;
	  goto out;
	}
    }

  /* No value found so far.  */
  *result = NULL;

  if (__builtin_expect (hst_resp.found == -1, 0))
    {
      /* The daemon does not cache this database.  */
      __nss_not_use_nscd_hosts = 1;
      goto out_close;
    }

  if (hst_resp.found == 1)
    {
      struct iovec vec[4];
      char *cp = buffer;
      uintptr_t align1;
      uintptr_t align2;
      size_t total_len;
      ssize_t cnt;
      char *ignore;
      int n;

      /* A first check whether the buffer is sufficiently large is possible.  */
      /* Now allocate the buffer the array for the group members.  We must
	 align the pointer and the base of the h_addr_list pointers.  */
      align1 = ((__alignof__ (char *) - (cp - ((char *) 0)))
		& (__alignof__ (char *) - 1));
      align2 = ((__alignof__ (char *) - ((cp + align1 + hst_resp.h_name_len)
					 - ((char *) 0)))
		& (__alignof__ (char *) - 1));
      if (buflen < (align1 + hst_resp.h_name_len + align2
		    + ((hst_resp.h_aliases_cnt + hst_resp.h_addr_list_cnt
			+ 2)
		       * sizeof (char *))
		    + hst_resp.h_addr_list_cnt * (type == AF_INET
						  ? INADDRSZ : IN6ADDRSZ)))
	{
	no_room:
	  *h_errnop = NETDB_INTERNAL;
	  __set_errno (ERANGE);
	  retval = ERANGE;
	  goto out_close;
	}
      cp += align1;

      /* Prepare the result as far as we can.  */
      resultbuf->h_aliases = (char **) cp;
      cp += (hst_resp.h_aliases_cnt + 1) * sizeof (char *);
      resultbuf->h_addr_list = (char **) cp;
      cp += (hst_resp.h_addr_list_cnt + 1) * sizeof (char *);

      resultbuf->h_name = cp;
      cp += hst_resp.h_name_len + align2;

      if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
	{
	  resultbuf->h_addrtype = AF_INET;
	  resultbuf->h_length = INADDRSZ;
	}
      else
	{
	  resultbuf->h_addrtype = AF_INET6;
	  resultbuf->h_length = IN6ADDRSZ;
	}
      for (cnt = 0; cnt < hst_resp.h_addr_list_cnt; ++cnt)
	{
	  resultbuf->h_addr_list[cnt] = cp;
	  cp += resultbuf->h_length;
	}
      resultbuf->h_addr_list[cnt] = NULL;

      if (h_name == NULL)
	{
	  vec[0].iov_base = resultbuf->h_name;
	  vec[0].iov_len = hst_resp.h_name_len;
	  total_len = hst_resp.h_name_len;
	  n = 1;

	  if (hst_resp.h_aliases_cnt > 0)
	    {
	      aliases_len = alloca (hst_resp.h_aliases_cnt
				    * sizeof (uint32_t));
	      vec[n].iov_base = (void *) aliases_len;
	      vec[n].iov_len = hst_resp.h_aliases_cnt * sizeof (uint32_t);

	      total_len += hst_resp.h_aliases_cnt * sizeof (uint32_t);
	      ++n;
	    }

	  if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
	    {
	      vec[n].iov_base = resultbuf->h_addr_list[0];
	      vec[n].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ;

	      total_len += hst_resp.h_addr_list_cnt * INADDRSZ;

	      ++n;
	    }
	  else
	    {
	      if (hst_resp.h_length == INADDRSZ)
		{
		  ignore = alloca (hst_resp.h_addr_list_cnt * INADDRSZ);
		  vec[n].iov_base = ignore;
		  vec[n].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ;

		  total_len += hst_resp.h_addr_list_cnt * INADDRSZ;

		  ++n;
		}

	      vec[n].iov_base = resultbuf->h_addr_list[0];
	      vec[n].iov_len = hst_resp.h_addr_list_cnt * IN6ADDRSZ;

	      total_len += hst_resp.h_addr_list_cnt * IN6ADDRSZ;

	      ++n;
	    }

	  if ((size_t) __readvall (sock, vec, n) != total_len)
	    goto out_close;
	}
      else
	{
	  memcpy (resultbuf->h_name, h_name, hst_resp.h_name_len);
	  memcpy (resultbuf->h_addr_list[0], addr_list, addr_list_len);
	}

      /*  Now we also can read the aliases.  */
      total_len = 0;
      for (cnt = 0; cnt < hst_resp.h_aliases_cnt; ++cnt)
	{
	  resultbuf->h_aliases[cnt] = cp;
	  cp += aliases_len[cnt];
	  total_len += aliases_len[cnt];
	}
      resultbuf->h_aliases[cnt] = NULL;

      if (__builtin_expect ((const char *) addr_list + addr_list_len
			    + total_len > recend, 0))
	{
	  /* aliases_len array might contain garbage during nscd GC cycle,
	     retry rather than fail in that case.  */
	  if (addr_list != NULL && mapped->head->gc_cycle != gc_cycle)
	    retval = -2;
	  goto out_close;
	}
      /* See whether this would exceed the buffer capacity.  */
      if (__builtin_expect (cp > buffer + buflen, 0))
	{
	  /* aliases_len array might contain garbage during nscd GC cycle,
	     retry rather than fail in that case.  */
	  if (addr_list != NULL && mapped->head->gc_cycle != gc_cycle)
	    {
	      retval = -2;
	      goto out_close;
	    }
	  goto no_room;
	}

      /* And finally read the aliases.  */
      if (addr_list == NULL)
	{
	  if (total_len == 0
	      || ((size_t) __readall (sock, resultbuf->h_aliases[0], total_len)
		  == total_len))
	    {
	      retval = 0;
	      *result = resultbuf;
	    }
	}
      else
	{
	  memcpy (resultbuf->h_aliases[0],
		  (const char *) addr_list + addr_list_len, total_len);

	  /* Try to detect corrupt databases.  */
	  if (resultbuf->h_name[hst_resp.h_name_len - 1] != '\0'
	      || ({for (cnt = 0; cnt < hst_resp.h_aliases_cnt; ++cnt)
		     if (resultbuf->h_aliases[cnt][aliases_len[cnt] - 1]
			 != '\0')
		       break;
		   cnt < hst_resp.h_aliases_cnt; }))
	    {
	      /* We cannot use the database.  */
	      if (mapped->head->gc_cycle != gc_cycle)
		retval = -2;
	      goto out_close;
	    }

	  retval = 0;
	  *result = resultbuf;
	}
    }
  else
    {
      /* Store the error number.  */
      *h_errnop = hst_resp.error;

      /* The `errno' to some value != ERANGE.  */
      __set_errno (ENOENT);
      /* Even though we have not found anything, the result is zero.  */
      retval = 0;
    }

 out_close:
  if (sock != -1)
    close_not_cancel_no_status (sock);
 out:
  if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
    {
      /* When we come here this means there has been a GC cycle while we
	 were looking for the data.  This means the data might have been
	 inconsistent.  Retry if possible.  */
      if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)
	{
	  /* nscd is just running gc now.  Disable using the mapping.  */
	  if (atomic_decrement_val (&mapped->counter) == 0)
	    __nscd_unmap (mapped);
	  mapped = NO_MAPPING;
	}

      if (retval != -1)
	goto retry;
    }

  return retval;
}
Commit	Line	Data
0ecb606c	1	/* Copyright (C) 1998-2005, 2006, 2007 Free Software Foundation, Inc.
67479a70 UD	2	This file is part of the GNU C Library.
	3	Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
	4
	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.
67479a70 UD	9
	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.
67479a70	14
41bdb6e2 AJ	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
67479a70	19
c207f23b	20	#include <assert.h>
67479a70 UD	21	#include <errno.h>
	22	#include <netdb.h>
	23	#include <resolv.h>
390955cb	24	#include <stdint.h>
67479a70 UD	25	#include <stdio.h>
	26	#include <stdlib.h>
	27	#include <string.h>
	28	#include <unistd.h>
	29	#include <arpa/nameser.h>
40c38b6c	30	#include <not-cancel.h>
67479a70	31
3f804c95	32	#include "nscd-client.h"
67479a70 UD	33	#include "nscd_proto.h"
	34
	35	int __nss_not_use_nscd_hosts;
	36
	37	static int nscd_gethst_r (const char *key, size_t keylen, request_type type,
	38	struct hostent resultbuf, char buffer,
261eada2 UD	39	size_t buflen, struct hostent **result,
261eada2 UD	40	int *h_errnop) internal_function;
67479a70 UD	41
	42
	43	int
	44	__nscd_gethostbyname_r (const char name, struct hostent resultbuf,
261eada2 UD	45	char buffer, size_t buflen, struct hostent *result,
261eada2 UD	46	int *h_errnop)
67479a70 UD	47	{
	48	request_type reqtype;
	49
	50	reqtype = (_res.options & RES_USE_INET6) ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
	51
	52	return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
261eada2	53	buffer, buflen, result, h_errnop);
67479a70 UD	54	}
	55
	56
	57	int
	58	__nscd_gethostbyname2_r (const char name, int af, struct hostent resultbuf,
261eada2 UD	59	char buffer, size_t buflen, struct hostent *result,
261eada2 UD	60	int *h_errnop)
67479a70 UD	61	{
	62	request_type reqtype;
	63
	64	reqtype = af == AF_INET6 ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
	65
	66	return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
261eada2	67	buffer, buflen, result, h_errnop);
67479a70 UD	68	}
	69
	70
	71	int
9d4d69b8	72	__nscd_gethostbyaddr_r (const void *addr, socklen_t len, int type,
67479a70	73	struct hostent resultbuf, char buffer, size_t buflen,
261eada2	74	struct hostent *result, int h_errnop)
67479a70 UD	75	{
	76	request_type reqtype;
	77
	78	if (!((len == INADDRSZ && type == AF_INET)
	79	\|\| (len == IN6ADDRSZ && type == AF_INET6)))
	80	/* LEN and TYPE do not match. */
1670698f	81	return -1;
67479a70 UD	82
	83	reqtype = type == AF_INET6 ? GETHOSTBYADDRv6 : GETHOSTBYADDR;
	84
261eada2	85	return nscd_gethst_r (addr, len, reqtype, resultbuf, buffer, buflen, result,
67479a70 UD	86	h_errnop);
	87	}
	88
	89
0ecb606c	90	libc_locked_map_ptr (, __hst_map_handle) attribute_hidden;
c207f23b UD	91	/* Note that we only free the structure if necessary. The memory
	92	mapping is not removed since it is not visible to the malloc
	93	handling. */
ed2ced8a	94	libc_freeres_fn (hst_map_free)
67479a70	95	{
ed2ced8a UD	96	if (__hst_map_handle.mapped != NO_MAPPING)
	97	{
	98	void *p = __hst_map_handle.mapped;
	99	__hst_map_handle.mapped = NO_MAPPING;
	100	free (p);
	101	}
67479a70 UD	102	}
	103
	104
	105	static int
813f4f4d	106	internal_function
67479a70 UD	107	nscd_gethst_r (const char *key, size_t keylen, request_type type,
67479a70 UD	108	struct hostent resultbuf, char buffer, size_t buflen,
261eada2	109	struct hostent *result, int h_errnop)
67479a70	110	{
0891f970 UD	111	int gc_cycle;
	112	int nretries = 0;
	113
	114	/* If the mapping is available, try to search there instead of
	115	communicating with the nscd. */
	116	struct mapped_database *mapped;
ed2ced8a UD	117	mapped = __nscd_get_map_ref (GETFDHST, "hosts", &__hst_map_handle,
ed2ced8a UD	118	&gc_cycle);
0891f970 UD	119
0891f970 UD	120	retry:;
c207f23b UD	121	const char *h_name = NULL;
	122	const uint32_t *aliases_len = NULL;
	123	const char *addr_list = NULL;
	124	size_t addr_list_len = 0;
	125	int retval = -1;
c207f23b UD	126	const char recend = (const char ) ~UINTMAX_C (0);
c207f23b UD	127	int sock = -1;
0ecb606c	128	hst_response_header hst_resp;
af38d7ce	129	if (mapped != NO_MAPPING)
67479a70	130	{
0ecb606c JJ	131	/* No const qualifier, as it can change during garbage collection. */
0ecb606c JJ	132	struct datahead *found = __nscd_cache_search (type, key, keylen, mapped);
c207f23b UD	133	if (found != NULL)
c207f23b UD	134	{
0ecb606c JJ	135	h_name = (char *) (&found->data[0].hstdata + 1);
	136	hst_resp = found->data[0].hstdata;
	137	aliases_len = (uint32_t *) (h_name + hst_resp.h_name_len);
c207f23b	138	addr_list = ((char *) aliases_len
0ecb606c JJ	139	+ hst_resp.h_aliases_cnt * sizeof (uint32_t));
	140	addr_list_len = hst_resp.h_addr_list_cnt * INADDRSZ;
	141	recend = (const char *) found->data + found->recsize;
	142	/* Now check if we can trust hst_resp fields. If GC is
	143	in progress, it can contain anything. */
	144	if (mapped->head->gc_cycle != gc_cycle)
	145	{
	146	retval = -2;
	147	goto out;
	148	}
c207f23b UD	149
	150	#ifndef _STRING_ARCH_unaligned
	151	/* The aliases_len array in the mapped database might very
	152	well be unaligned. We will access it word-wise so on
	153	platforms which do not tolerate unaligned accesses we
	154	need to make an aligned copy. */
	155	if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1))
	156	!= 0)
	157	{
0ecb606c	158	uint32_t *tmp = alloca (hst_resp.h_aliases_cnt
c207f23b UD	159	* sizeof (uint32_t));
c207f23b UD	160	aliases_len = memcpy (tmp, aliases_len,
0ecb606c	161	hst_resp.h_aliases_cnt
c207f23b UD	162	* sizeof (uint32_t));
	163	}
	164	#endif
	165	if (type != GETHOSTBYADDR && type != GETHOSTBYNAME)
	166	{
0ecb606c	167	if (hst_resp.h_length == INADDRSZ)
c207f23b	168	addr_list += addr_list_len;
0ecb606c	169	addr_list_len = hst_resp.h_addr_list_cnt * IN6ADDRSZ;
c207f23b	170	}
c207f23b UD	171	if (__builtin_expect ((const char *) addr_list + addr_list_len
c207f23b UD	172	> recend, 0))
0ecb606c	173	goto out;
c207f23b UD	174	}
	175	}
	176
0ecb606c	177	if (h_name == NULL)
c207f23b	178	{
0ecb606c JJ	179	sock = __nscd_open_socket (key, keylen, type, &hst_resp,
0ecb606c JJ	180	sizeof (hst_resp));
c207f23b UD	181	if (sock == -1)
	182	{
	183	__nss_not_use_nscd_hosts = 1;
0ecb606c	184	goto out;
c207f23b	185	}
67479a70 UD	186	}
67479a70 UD	187
16aac663 UD	188	/* No value found so far. */
	189	*result = NULL;
	190
0ecb606c	191	if (__builtin_expect (hst_resp.found == -1, 0))
67479a70 UD	192	{
67479a70 UD	193	/* The daemon does not cache this database. */
67479a70	194	__nss_not_use_nscd_hosts = 1;
c207f23b	195	goto out_close;
67479a70 UD	196	}
67479a70 UD	197
0ecb606c	198	if (hst_resp.found == 1)
67479a70	199	{
40c38b6c	200	struct iovec vec[4];
67479a70	201	char *cp = buffer;
3810076f UD	202	uintptr_t align1;
3810076f UD	203	uintptr_t align2;
67479a70 UD	204	size_t total_len;
	205	ssize_t cnt;
	206	char *ignore;
	207	int n;
	208
49c091e5	209	/* A first check whether the buffer is sufficiently large is possible. */
67479a70	210	/* Now allocate the buffer the array for the group members. We must
3810076f UD	211	align the pointer and the base of the h_addr_list pointers. */
	212	align1 = ((__alignof__ (char ) - (cp - ((char ) 0)))
	213	& (__alignof__ (char *) - 1));
0ecb606c	214	align2 = ((__alignof__ (char *) - ((cp + align1 + hst_resp.h_name_len)
3810076f UD	215	- ((char *) 0)))
3810076f UD	216	& (__alignof__ (char *) - 1));
0ecb606c JJ	217	if (buflen < (align1 + hst_resp.h_name_len + align2
0ecb606c JJ	218	+ ((hst_resp.h_aliases_cnt + hst_resp.h_addr_list_cnt
c207f23b	219	+ 2)
67479a70	220	* sizeof (char *))
0ecb606c JJ	221	+ hst_resp.h_addr_list_cnt * (type == AF_INET
0ecb606c JJ	222	? INADDRSZ : IN6ADDRSZ)))
67479a70 UD	223	{
67479a70 UD	224	no_room:
0ecb606c	225	*h_errnop = NETDB_INTERNAL;
67479a70	226	__set_errno (ERANGE);
261eada2	227	retval = ERANGE;
c207f23b	228	goto out_close;
67479a70	229	}
3810076f	230	cp += align1;
67479a70 UD	231
	232	/* Prepare the result as far as we can. */
	233	resultbuf->h_aliases = (char **) cp;
0ecb606c	234	cp += (hst_resp.h_aliases_cnt + 1) * sizeof (char *);
67479a70	235	resultbuf->h_addr_list = (char **) cp;
0ecb606c	236	cp += (hst_resp.h_addr_list_cnt + 1) * sizeof (char *);
67479a70 UD	237
67479a70 UD	238	resultbuf->h_name = cp;
0ecb606c	239	cp += hst_resp.h_name_len + align2;
67479a70	240
67479a70 UD	241	if (type == GETHOSTBYADDR \|\| type == GETHOSTBYNAME)
67479a70 UD	242	{
67479a70 UD	243	resultbuf->h_addrtype = AF_INET;
67479a70 UD	244	resultbuf->h_length = INADDRSZ;
67479a70 UD	245	}
	246	else
	247	{
c207f23b UD	248	resultbuf->h_addrtype = AF_INET6;
	249	resultbuf->h_length = IN6ADDRSZ;
	250	}
0ecb606c	251	for (cnt = 0; cnt < hst_resp.h_addr_list_cnt; ++cnt)
c207f23b UD	252	{
	253	resultbuf->h_addr_list[cnt] = cp;
	254	cp += resultbuf->h_length;
	255	}
	256	resultbuf->h_addr_list[cnt] = NULL;
67479a70	257
c207f23b UD	258	if (h_name == NULL)
	259	{
	260	vec[0].iov_base = resultbuf->h_name;
0ecb606c JJ	261	vec[0].iov_len = hst_resp.h_name_len;
0ecb606c JJ	262	total_len = hst_resp.h_name_len;
c207f23b	263	n = 1;
67479a70	264
0ecb606c	265	if (hst_resp.h_aliases_cnt > 0)
c207f23b	266	{
0ecb606c	267	aliases_len = alloca (hst_resp.h_aliases_cnt
c207f23b UD	268	* sizeof (uint32_t));
c207f23b UD	269	vec[n].iov_base = (void *) aliases_len;
0ecb606c	270	vec[n].iov_len = hst_resp.h_aliases_cnt * sizeof (uint32_t);
67479a70	271
0ecb606c	272	total_len += hst_resp.h_aliases_cnt * sizeof (uint32_t);
c207f23b UD	273	++n;
c207f23b UD	274	}
67479a70	275
c207f23b	276	if (type == GETHOSTBYADDR \|\| type == GETHOSTBYNAME)
67479a70	277	{
c207f23b	278	vec[n].iov_base = resultbuf->h_addr_list[0];
0ecb606c	279	vec[n].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ;
c207f23b	280
0ecb606c	281	total_len += hst_resp.h_addr_list_cnt * INADDRSZ;
c207f23b UD	282
c207f23b UD	283	++n;
67479a70	284	}
c207f23b UD	285	else
c207f23b UD	286	{
0ecb606c	287	if (hst_resp.h_length == INADDRSZ)
c207f23b	288	{
0ecb606c	289	ignore = alloca (hst_resp.h_addr_list_cnt * INADDRSZ);
c207f23b	290	vec[n].iov_base = ignore;
0ecb606c	291	vec[n].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ;
67479a70	292
0ecb606c	293	total_len += hst_resp.h_addr_list_cnt * INADDRSZ;
67479a70	294
c207f23b UD	295	++n;
c207f23b UD	296	}
67479a70	297
c207f23b	298	vec[n].iov_base = resultbuf->h_addr_list[0];
0ecb606c	299	vec[n].iov_len = hst_resp.h_addr_list_cnt * IN6ADDRSZ;
67479a70	300
0ecb606c	301	total_len += hst_resp.h_addr_list_cnt * IN6ADDRSZ;
c207f23b UD	302
	303	++n;
	304	}
	305
0ecb606c	306	if ((size_t) __readvall (sock, vec, n) != total_len)
c207f23b UD	307	goto out_close;
	308	}
	309	else
	310	{
0ecb606c	311	memcpy (resultbuf->h_name, h_name, hst_resp.h_name_len);
c207f23b UD	312	memcpy (resultbuf->h_addr_list[0], addr_list, addr_list_len);
c207f23b UD	313	}
67479a70 UD	314
	315	/* Now we also can read the aliases. */
	316	total_len = 0;
0ecb606c	317	for (cnt = 0; cnt < hst_resp.h_aliases_cnt; ++cnt)
67479a70 UD	318	{
	319	resultbuf->h_aliases[cnt] = cp;
	320	cp += aliases_len[cnt];
	321	total_len += aliases_len[cnt];
	322	}
	323	resultbuf->h_aliases[cnt] = NULL;
	324
c207f23b UD	325	if (__builtin_expect ((const char *) addr_list + addr_list_len
c207f23b UD	326	+ total_len > recend, 0))
0ecb606c JJ	327	{
	328	/* aliases_len array might contain garbage during nscd GC cycle,
	329	retry rather than fail in that case. */
	330	if (addr_list != NULL && mapped->head->gc_cycle != gc_cycle)
	331	retval = -2;
	332	goto out_close;
	333	}
67479a70	334	/* See whether this would exceed the buffer capacity. */
c207f23b	335	if (__builtin_expect (cp > buffer + buflen, 0))
0ecb606c JJ	336	{
	337	/* aliases_len array might contain garbage during nscd GC cycle,
	338	retry rather than fail in that case. */
	339	if (addr_list != NULL && mapped->head->gc_cycle != gc_cycle)
	340	{
	341	retval = -2;
	342	goto out_close;
	343	}
	344	goto no_room;
	345	}
67479a70 UD	346
67479a70 UD	347	/* And finally read the aliases. */
c207f23b UD	348	if (addr_list == NULL)
c207f23b UD	349	{
0ecb606c JJ	350	if (total_len == 0
	351	\|\| ((size_t) __readall (sock, resultbuf->h_aliases[0], total_len)
	352	== total_len))
c207f23b UD	353	{
	354	retval = 0;
	355	*result = resultbuf;
	356	}
	357	}
	358	else
261eada2	359	{
c207f23b UD	360	memcpy (resultbuf->h_aliases[0],
	361	(const char *) addr_list + addr_list_len, total_len);
	362
5429ff76	363	/* Try to detect corrupt databases. */
0ecb606c JJ	364	if (resultbuf->h_name[hst_resp.h_name_len - 1] != '\0'
0ecb606c JJ	365	\|\| ({for (cnt = 0; cnt < hst_resp.h_aliases_cnt; ++cnt)
5429ff76 UD	366	if (resultbuf->h_aliases[cnt][aliases_len[cnt] - 1]
	367	!= '\0')
	368	break;
0ecb606c JJ	369	cnt < hst_resp.h_aliases_cnt; }))
	370	{
	371	/* We cannot use the database. */
	372	if (mapped->head->gc_cycle != gc_cycle)
	373	retval = -2;
	374	goto out_close;
	375	}
5429ff76	376
261eada2 UD	377	retval = 0;
	378	*result = resultbuf;
	379	}
67479a70 UD	380	}
	381	else
	382	{
	383	/* Store the error number. */
0ecb606c	384	*h_errnop = hst_resp.error;
67479a70	385
336dfb2d UD	386	/* The `errno' to some value != ERANGE. */
336dfb2d UD	387	__set_errno (ENOENT);
261eada2 UD	388	/* Even though we have not found anything, the result is zero. */
261eada2 UD	389	retval = 0;
67479a70	390	}
12c80513	391
c207f23b UD	392	out_close:
	393	if (sock != -1)
	394	close_not_cancel_no_status (sock);
12c80513	395	out:
0ecb606c	396	if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
0891f970 UD	397	{
	398	/* When we come here this means there has been a GC cycle while we
	399	were looking for the data. This means the data might have been
	400	inconsistent. Retry if possible. */
0ecb606c	401	if ((gc_cycle & 1) != 0 \|\| ++nretries == 5 \|\| retval == -1)
0891f970 UD	402	{
0891f970 UD	403	/* nscd is just running gc now. Disable using the mapping. */
0ecb606c JJ	404	if (atomic_decrement_val (&mapped->counter) == 0)
0ecb606c JJ	405	__nscd_unmap (mapped);
0891f970 UD	406	mapped = NO_MAPPING;
	407	}
	408
0ecb606c JJ	409	if (retval != -1)
0ecb606c JJ	410	goto retry;
0891f970	411	}
12c80513	412
261eada2	413	return retval;
67479a70	414	}