/* Copyright (C) 1996-2001,2003, 2004 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 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, see <http://www.gnu.org/licenses/>. */ #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 # define H_ERRNO_VAR_P &h_errno_tmp #else # define H_ERRNO_PARM # define H_ERRNO_VAR # define H_ERRNO_VAR_P NULL #endif #ifdef HAVE_AF # define AF_VAL af #else # define AF_VAL AF_INET #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. */ libc_freeres_ptr (static char *buffer); LOOKUP_TYPE * FUNCTION_NAME (ADD_PARAMS) { static size_t buffer_size; static LOOKUP_TYPE resbuf; LOOKUP_TYPE *result; #ifdef NEED_H_ERRNO int h_errno_tmp = 0; #endif /* Get lock. */ __libc_lock_lock (lock); if (buffer == NULL) { buffer_size = BUFLEN; buffer = (char *) malloc (buffer_size); } #ifdef HANDLE_DIGITS_DOTS if (buffer != NULL) { if (__nss_hostname_digits_dots (name, &resbuf, &buffer, &buffer_size, 0, &result, NULL, AF_VAL, H_ERRNO_VAR_P)) goto done; } #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 *= 2; new_buf = (char *) 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. */ free (buffer); __set_errno (ENOMEM); } buffer = new_buf; } if (buffer == NULL) result = NULL; #ifdef HANDLE_DIGITS_DOTS done: #endif /* Release lock. */ __libc_lock_unlock (lock); #ifdef NEED_H_ERRNO if (h_errno_tmp != 0) __set_h_errno (h_errno_tmp); #endif return result; } static_link_warning (FUNCTION_NAME)