glibc/nss/getXXent_r.c
1996-10-02 01:40:17 +00:00

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/* Copyright (C) 1996 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 <libc-lock.h>
#include "nsswitch.h"
/*******************************************************************\
|* Here we assume several symbols to be defined: *|
|* *|
|* LOOKUP_TYPE - the return type of the function *|
|* *|
|* SETFUNC_NAME - name of the non-reentrant setXXXent function *|
|* *|
|* GETFUNC_NAME - name of the non-reentrant getXXXent function *|
|* *|
|* ENDFUNC_NAME - name of the non-reentrant endXXXent function *|
|* *|
|* DATABASE_NAME - name of the database the function accesses *|
|* (e.g., host, services, ...) *|
|* *|
|* Optionally the following vars can be defined: *|
|* *|
|* STAYOPEN - variable declaration for setXXXent function *|
|* *|
|* STAYOPEN_VAR - variable name for setXXXent function *|
|* *|
|* NEED_H_ERRNO - an extra parameter will be passed to point to *|
|* the global `h_errno' variable. *|
|* *|
\*******************************************************************/
/* To make the real sources a bit prettier. */
#define REENTRANT_GETNAME APPEND_R (GETFUNC_NAME)
#define APPEND_R(name) APPEND_R1 (name)
#define APPEND_R1(name) name##_r
#define INTERNAL(name) INTERNAL1 (name)
#define INTERNAL1(name) __##name
#define SETFUNC_NAME_STRING STRINGIZE (SETFUNC_NAME)
#define GETFUNC_NAME_STRING STRINGIZE (REENTRANT_GETNAME)
#define ENDFUNC_NAME_STRING STRINGIZE (ENDFUNC_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_errno
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
#endif
/* Some databases take the `stayopen' flag. */
#ifndef STAYOPEN
#define STAYOPEN void
#define STAYOPEN_VAR
#endif
/* Prototype for the setXXXent functions we use here. */
typedef int (*set_function) (STAYOPEN);
/* Prototype for the endXXXent functions we use here. */
typedef int (*end_function) (void);
/* Prototype for the setXXXent functions we use here. */
typedef int (*get_function) (LOOKUP_TYPE *, char *, int H_ERRNO_PARM);
/* This handle for the NSS data base is shared between all
set/get/endXXXent functions. */
static service_user *nip;
/* Remember the first service_entry, it's always the same. */
static service_user *startp;
/* Protect above variable against multiple uses at the same time. */
__libc_lock_define_initialized (static, lock)
/* The lookup function for the first entry of this service. */
extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp);
/* Set up NIP to run through the services. If ALL is zero, use NIP's
current location if it's not nil. Return nonzero if there are no
services (left). */
static enum nss_status
setup (void **fctp, const char *func_name, int all)
{
int no_more;
if (startp == NULL)
{
no_more = DB_LOOKUP_FCT (&nip, func_name, fctp);
startp = no_more ? (service_user *) -1 : nip;
}
else if (startp == (service_user *) -1)
/* No services at all. */
return 1;
else
{
if (all || !nip)
/* Reset to the beginning of the service list. */
nip = startp;
/* Look up the first function. */
no_more = __nss_lookup (&nip, func_name, fctp);
}
return no_more;
}
void
SETFUNC_NAME (STAYOPEN)
{
set_function fct;
int no_more;
#ifdef NEED__RES
if ((_res.options & RES_INIT) == 0 && res_init () == -1)
{
__set_h_errno (NETDB_INTERNAL);
return NULL;
}
#endif /* need _res */
__libc_lock_lock (lock);
/* Cycle through all the services and run their setXXent functions. */
no_more = setup ((void **) &fct, SETFUNC_NAME_STRING, 1);
while (! no_more)
{
/* Ignore status, we force check in __NSS_NEXT. */
(void) (*fct) (STAYOPEN_VAR);
no_more = __nss_next (&nip, SETFUNC_NAME_STRING, (void **) &fct, 0, 1);
}
__libc_lock_unlock (lock);
}
void
ENDFUNC_NAME (void)
{
end_function fct;
int no_more;
#ifdef NEED__RES
if ((_res.options & RES_INIT) == 0 && res_init () == -1)
{
__set_h_errno (NETDB_INTERNAL);
return NULL;
}
#endif /* need _res */
__libc_lock_lock (lock);
/* Cycle through all the services and run their endXXent functions. */
no_more = setup ((void **) &fct, ENDFUNC_NAME_STRING, 1);
while (! no_more)
{
/* Ignore status, we force check in __NSS_NEXT. */
(void) (*fct) ();
no_more = __nss_next (&nip, ENDFUNC_NAME_STRING, (void **) &fct, 0, 1);
}
__libc_lock_unlock (lock);
}
LOOKUP_TYPE *
INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *result, char *buffer, int buflen
H_ERRNO_PARM)
{
get_function fct;
int no_more;
enum nss_status status;
#ifdef NEED__RES
if ((_res.options & RES_INIT) == 0 && res_init () == -1)
{
__set_h_errno (NETDB_INTERNAL);
return NULL;
}
#endif /* need _res */
/* Initialize status to return if no more functions are found. */
status = NSS_STATUS_NOTFOUND;
__libc_lock_lock (lock);
/* Run through available functions, starting with the same function last
run. We will repeat each function as long as it succeeds, and then go
on to the next service action. */
no_more = setup ((void **) &fct, GETFUNC_NAME_STRING, 0);
while (! no_more)
{
status = (*fct) (result, buffer, buflen H_ERRNO_VAR);
no_more = __nss_next (&nip, GETFUNC_NAME_STRING, (void **) &fct,
status, 0);
}
__libc_lock_unlock (lock);
return status == NSS_STATUS_SUCCESS ? result : NULL;
}
#define do_weak_alias(n1, n2) weak_alias (n1, n2)
do_weak_alias (INTERNAL (REENTRANT_GETNAME), REENTRANT_GETNAME)