/* WARNING: This file was generated by dkct. Changes you make here will be lost if dkct is run again! You should modify the original source and run dkct on it. Original source: dk4dmt.ctr */ /* Copyright (C) 2016-2017, Dirk Krause Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above opyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the author nor the names of contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef DK4DMT_H_INCLUDED /** Avoid multiple inclusions. */ #define DK4DMT_H_INCLUDED 1 #line 8 "dk4dmt.ctr" /** @file dk4dmt.h Daemon tools. The functions in this module can be used in standing daemons. In the original process, call the dk4dmt_parent_before_fork() function to close all file descriptors above 2, reset all signal handlers to defaults, unblock all signals and check whether a PID file already exists. If you plan to give up root privileges in the child processes (use setgid() and setuid() to change effective user and group), do not use /var/run/program.pid as PID file name, better use /var/run/program/program.pid instead and make sure to set ownership and group on /var/run/program to the unprivileged user and group used by the child process. User and group need write permission to the directory, so the unprivileged child process can remove the PID file when exiting. In the intermediate process after the first fork call dk4dmt_intermediate_before_fork(). Among other things this function completely decouples the process from the terminal. In the final process (after forking again) call dk4dmt_daemon_after_fork() to set up things before starting service. This function creates the PID file, connects file descriptors 0, 1 and 2 to /dev/null, resets the umask and changes into the / directory. After finishing service call dk4dmt_daemon_end() before exiting. This function removes the PID file. */ #ifdef __cplusplus extern "C" { #endif /** Activities in parent process before calling fork(). * Close all file descriptors above 2. * Reset all signal actions to default handlers. * Unblock all signals. * Check whether PID file already exists. Use this function to check whether the initial process can run fork(). @param prgname Program name. @param pidfilename PID file name. @param logstderr Flag: Logging to stderr allowed. @param slf Syslog feature. @return 1 on success (can call fork), 0 on error (abort). */ int dk4dmt_parent_before_fork( const char *prgname, const char *pidfilename, int logstderr, int slf ); /** Activities in first child before calling fork() again. * Decouple completely from terminal. Use this function to check whether the first child process can run fork() again. @param prgname Program name. @param slf Syslog feature. @return 1 on success (can call fork), 0 on error (abort). */ int dk4dmt_intermediate_before_fork(const char *prgname, int slf); /** Activities in final daemon process. * Create PID file. * Connect file descriptors 0, 1 and 2 to /dev/null. * Reset umask. * Change into / directory. @param prgname Program name. @param pidfilename File name for PID file. @param slf Syslog feature. @return 1 on success, 0 on error. */ int dk4dmt_daemon_after_fork(const char *prgname, const char *pidfilename, int slf); /** End of daemon, remove PID file. @param prgname Program name. @param pidfilename PID file name. @param slf Syslog feature. */ void dk4dmt_daemon_end(const char *prgname, const char *pidfilename, int slf); #ifdef __cplusplus } #endif #endif