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/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed 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. */
#include <errno.h>
#include "nsswitch.h"
#include <nscd/nscd_proto.h>
/*******************************************************************\
|* Here we assume several symbols to be defined: *|
|* *|
|* LOOKUP_TYPE - the return type of the function *|
|* *|
|* FUNCTION_NAME - name of the non-reentrant function *|
|* *|
|* DATABASE_NAME - name of the database the function accesses *|
|* (e.g., host, services, ...) *|
|* *|
|* ADD_PARAMS - additional parameter, can vary in number *|
|* *|
|* ADD_VARIABLES - names of additional parameter *|
|* *|
|* Optionally the following vars can be defined: *|
|* *|
|* NEED_H_ERRNO - an extra parameter will be passed to point to *|
|* the global `h_errno' variable. *|
|* *|
|* NEED__RES - the global _res variable might be used so we *|
|* will have to initialize it if necessary *|
|* *|
\*******************************************************************/
/* To make the real sources a bit prettier. */
#define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
#define APPEND_R(name) APPEND_R1 (name)
#define APPEND_R1(name) name##_r
#define INTERNAL(name) INTERNAL1 (name)
#define INTERNAL1(name) __##name
#ifdef USE_NSCD
# define NSCD_NAME ADD_NSCD (REENTRANT_NAME)
# define ADD_NSCD(name) ADD_NSCD1 (name)
# define ADD_NSCD1(name) __nscd_##name
#endif
#define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME)
#define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME)
#define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
#define STRINGIZE(name) STRINGIZE1 (name)
#define STRINGIZE1(name) #name
#define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup)
#define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
#define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
/* Sometimes we need to store error codes in the `h_errno' variable. */
#ifdef NEED_H_ERRNO
# define H_ERRNO_PARM , int *h_errnop
# define H_ERRNO_VAR , h_errnop
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
#endif
/* Type of the lookup function we need here. */
typedef int (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *, size_t,
int * H_ERRNO_PARM);
/* Some usages of this file might use this variable. */
extern struct __res_state _res;
/* The lookup function for the first entry of this service. */
extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp);
/* Nonzero if the NSCD is not available. This variable will be increased
whenever we try to use the NSCD but see it is not avilable. So we
can recheck the presence every once in a while. */
extern int __nss_nscd_not_available;
/* Interval in which we transfer retry to contact the NSCD. */
#define NSS_NSCD_RETRY 100
int
INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
{
static service_user *startp = NULL;
static lookup_function start_fct;
service_user *nip;
lookup_function fct;
int no_more;
enum nss_status status = NSS_STATUS_UNAVAIL;
#ifdef USE_NSCD
int nscd_status;
#endif
#ifdef HANDLE_DIGITS_DOTS
# define resbuf (*resbuf)
# include "digits_dots.c"
# undef resbuf
#endif
#ifdef USE_NSCD
if (__nss_nscd_not_available && ++__nss_nscd_not_available > NSS_NSCD_RETRY)
__nss_nscd_not_available = 0;
if (!__nss_nscd_not_available)
{
nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen
H_ERRNO_VAR);
if (nscd_status < 1)
{
*result = nscd_status == 0 ? resbuf : NULL;
return nscd_status;
}
if (nscd_status == 2)
/* This return value indicates that contacting the server failed. */
__nss_nscd_not_available = 1;
}
#endif
if (startp == NULL)
{
no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING, (void **) &fct);
if (no_more)
startp = (service_user *) -1l;
else
{
startp = nip;
start_fct = fct;
#ifdef NEED__RES
/* The resolver code will really be used so we have to
initialize it. */
if ((_res.options & RES_INIT) == 0 && res_init () == -1)
{
*h_errnop = NETDB_INTERNAL;
*result = NULL;
return -1;
}
#endif /* need _res */
}
}
else
{
fct = start_fct;
no_more = (nip = startp) == (service_user *) -1l;
}
while (no_more == 0)
{
status = (*fct) (ADD_VARIABLES, resbuf, buffer, buflen,
__errno_location () H_ERRNO_VAR);
/* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
provided buffer is too small. In this case we should give
the user the possibility to enlarge the buffer and we should
not simply go on with the next service (even if the TRYAGAIN
action tells us so). */
if (status == NSS_STATUS_TRYAGAIN
#ifdef NEED_H_ERRNO
&& *h_errnop == NETDB_INTERNAL
#endif
&& errno == ERANGE)
break;
no_more = __nss_next (&nip, REENTRANT_NAME_STRING,
(void **) &fct, status, 0);
}
#ifdef HANDLE_DIGITS_DOTS
done:
#endif
*result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
return status == NSS_STATUS_SUCCESS ? 0 : -1;
}
#define do_weak_alias(n1, n2) weak_alias (n1, (n2))
do_weak_alias (INTERNAL (REENTRANT_NAME), REENTRANT_NAME)
|
