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/* Copyright (C) 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
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. */
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include "nsswitch.h"
/* We avoid using a too large buffer in case the user is accumulating the
results and there is lots of unused space in the allocated buffer. */
#define BUFLEN 512
/* Internal function to test whether IPv4 and/or IPv6 are available. */
extern void __protocol_available (int *have_inet, int *have_inet6)
internal_function;
/* Type of the lookup function we need here. */
typedef enum nss_status (*lookup_function) (const char *, int, int,
struct hostent *, char *,
size_t, int *, int *);
/* The lookup function for the first entry of this service. */
extern int __nss_hosts_lookup (service_user **nip, const char *name,
void **fctp);
struct hostent *
getipnodebyname (const char *name, int type, int flags, int *h_errnop)
{
static service_user *startp;
static lookup_function start_fct;
service_user *nip;
lookup_function fct;
int no_more;
size_t buffer_size;
char *buffer;
struct hostent *result;
int save;
int have_inet = 1;
int have_inet6 = 1;
/* First determine whether we have the appropriate interfaces.
XXX I don't think we can cache the result since the system
can be reconfigured. */
if ((flags & AI_ADDRCONFIG) != 0)
__protocol_available (&have_inet, &have_inet6);
/* Handle impossible requests first. */
if ((type == AF_INET && have_inet == 0)
|| (type == AF_INET6 && have_inet6 == 0 && ((flags & AI_V4MAPPED) == 0
|| have_inet == 0))
|| (type != AF_INET && type != AF_INET6))
{
*h_errnop = NO_DATA;
return NULL;
}
buffer_size = BUFLEN;
buffer = (char *) malloc (buffer_size);
result = NULL;
if (buffer != NULL)
{
#define HAVE_TYPE
#define resbuf (*((struct hostent *) buffer))
#include "../nss/digits_dots.c"
}
if (startp == NULL)
{
no_more = __nss_hosts_lookup (&nip, "getipnodebyname_r", (void **) &fct);
if (no_more)
startp = (service_user *) -1l;
else
{
startp = nip;
start_fct = fct;
}
}
else
{
fct = start_fct;
no_more = (nip = startp) == (service_user *) -1l;
}
/* First do a lookup with the original protocol type. */
while (no_more == 0 && buffer != NULL)
{
enum nss_status status;
status = DL_CALL_FCT (fct, (name, type,
((flags & AI_ALL)
? flags : (flags & ~AI_V4MAPPED)),
(struct hostent *) buffer,
(char *) ((struct hostent *) buffer + 1),
buffer_size - sizeof (struct hostent),
&errno, h_errnop));
if (status == NSS_STATUS_SUCCESS)
{
result = (struct hostent *) buffer;
break;
}
if (status == NSS_STATUS_TRYAGAIN && *h_errnop == NETDB_INTERNAL
&& errno == ERANGE)
{
/* Resize the buffer, it's too small. */
buffer_size += BUFLEN;
buffer = (char *) realloc (buffer, buffer_size);
continue;
}
no_more = __nss_next (&nip, "getipnodebyname_r",
(void **) &fct, status, 0);
}
/* If we are looking for an IPv6 address but haven't found any and
do not have the AI_ALL but the AI_V4MAPPED flag set, now try
looking up an IPv4 address and map it. */
if (buffer != NULL && result == NULL
&& type == AF_INET6 && (flags & AI_V4MAPPED) != 0
&& (no_more = (nip = startp) == (service_user *) -1l) == 0)
{
/* We have to use a new buffer if there is already a result. */
fct = start_fct;
do
{
enum nss_status status;
status = DL_CALL_FCT (fct, (name, type, flags,
(struct hostent *) buffer,
(char *) ((struct hostent *) buffer + 1),
buffer_size - sizeof (struct hostent),
&errno, h_errnop));
if (status == NSS_STATUS_SUCCESS)
{
result = (struct hostent *) buffer;
break;
}
if (status == NSS_STATUS_TRYAGAIN && *h_errnop == NETDB_INTERNAL
&& errno == ERANGE)
{
/* Resize the buffer, it's too small. */
buffer_size += BUFLEN;
buffer = (char *) realloc (buffer, buffer_size);
continue;
}
no_more = __nss_next (&nip, "getipnodebyname_r",
(void **) &fct, status, 0);
}
while (no_more == 0 && buffer != NULL);
}
done:
if (buffer == NULL)
{
/* We are out of memory. */
*h_errnop = TRY_AGAIN;
assert (result == NULL);
}
else if (result == NULL && buffer != NULL)
free (buffer);
return result;
}
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