mbedtls/programs/test/syslog2stderr.c
2018-03-01 09:20:34 -05:00

70 lines
2.0 KiB
C

/** \brief Syslog to stderr wrapper for Unix-like systems
*
* By dynamically linking this module into an executable, any message sent to the system logs
* via the POSIX or Linux API is instead redirected to standard error.
*
* Compile this program with `cc -fPID -shared -o syslog2stderr.so syslog2stderr.c -ldl`
* and load it dynamically when running `myprogram` with
* `LD_PRELOAD=/path/to/syslog2stderr.so myprogram`.
* On macOS, replace `LD_PRELOAD` by `DYLD_PRELOAD`.
*/
/**
* Copyright (C) 2017-2018, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#include <dlfcn.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
void openlog( const char *ident, int option, int facility )
{
(void) ident;
(void) option;
(void) facility;
}
/* POSIX API */
void syslog( int priority, const char *format, ... )
{
va_list args;
va_start( args, format );
vfprintf( stderr, format, args );
va_end( args );
}
/* Linux ABI
* http://refspecs.linux-foundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/libc---syslog-chk-1.html
*/
void __syslog_chk( int priority, int flag, const char *format, ... )
{
va_list args;
(int) flag;
va_start( args, format );
vfprintf( stderr, format, args );
fputc( '\n', stderr );
va_end( args );
}
void closelog( void )
{
/* no-op */
}