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#include <iostream> |
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#include <signal.h> |
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#include <fcntl.h> |
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#include "daemon.h" |
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#include "common.h" |
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using namespace std; |
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|
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void signal_handler(int sig) |
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{ |
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switch(sig) { |
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case SIGHUP: |
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Common::instance()->logMessage("hangup signal catched"); |
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break; |
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|
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case SIGTERM: |
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Common::instance()->logMessage("terminate signal catched...exiting"); |
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Common::instance()->mainContinue = false; |
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break; |
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} |
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} |
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|
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void daemonCleanup() |
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{ |
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unlink( Common::instance()->pidfile.c_str() ); |
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} |
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|
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void daemonize() |
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{ |
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int i, lfp; |
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char str[10]; |
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Common* cmn = Common::instance(); |
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|
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if (getuid() != 0) |
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{ |
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cout << "Please start this daemon as root\n" << endl; |
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daemon_shutdown(0); |
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} |
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|
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|
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if (getppid() == 1) /* already a daemon */ |
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return; |
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|
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i=fork(); |
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|
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if (i<0) /* fork error */ |
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daemon_shutdown(FORK_ERROR); |
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if (i>0) /* parent exits */ |
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daemon_shutdown(0); |
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/* child daemon continues */ |
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|
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setsid(); /* obtain a new process group */ |
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|
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for (i=getdtablesize(); i>=0; --i) |
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close(i); /*close all descriptors*/ |
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i=open("/dev/null", O_RDWR); /* handle std. io */ |
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dup(i); |
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dup(i); |
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umask(027); /* set newly created file permissions */ |
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|
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chdir("/tmp"); /* change running directory*/ |
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|
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/*attempt to create lockfile and put a file-lock on it*/ |
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lfp=open(cmn->pidfile.c_str(), O_RDWR|O_CREAT, 0640); |
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if (lfp<0) /* can not open */ |
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daemon_shutdown(CANT_OPEN_LOCK); |
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if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */ |
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daemon_shutdown(ALREADY_LOCKED); |
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|
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/* first instance continues */ |
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sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */ |
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write(lfp, str, strlen(str) ); |
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signal(SIGCHLD, SIG_IGN); /* ignore child */ |
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signal(SIGTSTP, SIG_IGN); /* ignore tty signals */ |
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signal(SIGTTOU, SIG_IGN); |
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signal(SIGTTIN, SIG_IGN); |
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signal(SIGHUP, signal_handler); /* catch hangup signal */ |
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signal(SIGTERM, signal_handler); /* catch kill signal */ |
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|
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/*this program is now a daemon*/ |
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setegid( cmn->gid ); |
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seteuid( cmn->uid ); |
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} |