/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. 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 <errno.h> #include <bits/libc-lock.h> #include <stdlib.h> #include <resolv.h> #include "nsswitch.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 *| |* *| |* BUFLEN - length of buffer allocated for the non *| |* reentrant version *| |* *| |* Optionally the following vars can be defined: *| |* *| |* 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_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 /* 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_tmp #else # define H_ERRNO_PARM # define H_ERRNO_VAR #endif /* Prototype for reentrant version we use here. */ extern int INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer, size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM); /* We need to protect the dynamic buffer handling. */ __libc_lock_define_initialized (static, lock); /* This points to the static buffer used. */ static char *buffer; LOOKUP_TYPE * FUNCTION_NAME (ADD_PARAMS) { static size_t buffer_size; static LOOKUP_TYPE resbuf; LOOKUP_TYPE *result; int save; #ifdef NEED_H_ERRNO int h_errno_tmp = 0; # ifdef HANDLE_DIGITS_DOTS int *const h_errnop = &h_errno_tmp;; # endif #endif /* Get lock. */ __libc_lock_lock (lock); if (buffer == NULL) { buffer_size = BUFLEN; buffer = malloc (buffer_size); } if (buffer != NULL) { #ifdef HANDLE_DIGITS_DOTS /* We have to test for the use of IPv6 which can only be done by examining `_res'. */ if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1) { # ifdef NEED_H_ERRNO h_errno_tmp = NETDB_INTERNAL; # endif result = NULL; goto done; } # include "digits_dots.c" #endif } while (buffer != NULL && (INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, &resbuf, buffer, buffer_size, &result H_ERRNO_VAR) == ERANGE) #ifdef NEED_H_ERRNO && h_errno_tmp == NETDB_INTERNAL #endif ) { char *new_buf; buffer_size += BUFLEN; new_buf = realloc (buffer, buffer_size); if (new_buf == NULL) { /* We are out of memory. Free the current buffer so that the process gets a chance for a normal termination. */ save = errno; free (buffer); __set_errno (save); } buffer = new_buf; } if (buffer == NULL) result = NULL; #ifdef HANDLE_DIGITS_DOTS done: #endif /* Release lock. Preserve error value. */ save = errno; __libc_lock_unlock (lock); __set_errno (save); #ifdef NEED_H_ERRNO if (h_errno_tmp != 0) __set_h_errno (h_errno_tmp); #endif return result; } /* Free all resources if necessary. */ static void __attribute__ ((unused)) free_mem (void) { if (buffer != NULL) free (buffer); } text_set_element (__libc_subfreeres, free_mem);