fixed signal handling, so that dudki can be HUP-ped more than once.0.0

1 files changed, 5 insertions, 0 deletions

diff --git a/src/dudki.cc b/src/dudki.cc
index 3c50e56..b769109 100644
--- a/src/dudki.cc
+++ b/src/dudki.cc
@@ -1,244 +1,249 @@
 #include <unistd.h>
 #include <signal.h>
 #include <syslog.h>
 #include <iostream>
 #include <fstream>
 #include <stdexcept>
 using namespace std;
 #include "configuration.h"
 #include "util.h"
 
 #include "config.h"
 #ifdef HAVE_GETOPT_H
 # include <getopt.h>
 #endif
 
 #ifndef DEFAULT_CONF_FILE
 # define DEFAULT_CONF_FILE "/etc/dudki.conf"
 #endif
 
 #define PHEADER PACKAGE " Version " VERSION
 #define PCOPY   "Copyright (c) 2004 Klever Group"
 
 bool finishing = false;
 static char **_argv = NULL;
 
 static void lethal_signal_handler(int signum) {
     syslog(LOG_NOTICE,"Lethal signal received. Terminating.");
     finishing = true;
 }
 static void sighup_handler(int signum) {
     syslog(LOG_NOTICE,"SUGHUP received, reloading.");
     execvp(_argv[0],_argv);
 }
 
 void check_herd(configuration& config) {
     for(processes_t::iterator i=config.processes.begin();i!=config.processes.end();++i)
 	i->second.check(i->first,config);
 }
 
 void signal_self(const configuration& config,int signum) {
     ifstream pids(config.pidfile.c_str(),ios::in);
     if(!pids)
 	throw runtime_error("Can't detect running instance");
     pid_t pid = 0;
     pids >> pid;
     if(!pid)
 	throw runtime_error("Can't detect running instance");
     if(pid==getpid())
 	throw 0;
     if(kill(pid,signum))
 	throw runtime_error("Failed to signal running instance");
 }
 
 int main(int argc,char **argv) {
     try {
 	_argv = new char*[argc+1];
 	if(!_argv)
 	    throw runtime_error("memory allocation problem at the very start");
 	memmove(_argv,argv,sizeof(*_argv)*(argc+1));
 	string config_file = DEFAULT_CONF_FILE;
 	enum {
 	    op_default,
 	    op_work,
 	    op_hup,
 	    op_term,
 	    op_check,
 	    op_ensure,
 	    op_test
 	} op = op_default;
 	while(true) {
 #define	SHORTOPTSTRING "f:hVLrkcet"
 #ifdef HAVE_GETOPT_LONG
 	    static struct option opts[] = {
 		{ "help", no_argument, 0, 'h' },
 		{ "usage", no_argument, 0, 'h' },
 		{ "version", no_argument, 0, 'V' },
 		{ "license", no_argument, 0, 'L' },
 		{ "config", required_argument, 0, 'f' },
 		{ "kill", no_argument, 0, 'k' },
 		{ "reload", no_argument, 0, 'r' },
 		{ "check", no_argument, 0, 'c' },
 		{ "ensure", no_argument, 0, 'e' },
 		{ "test", no_argument, 0, 't' },
 		{ NULL, 0, 0, 0 }
 	    };
 	    int c = getopt_long(argc,argv,SHORTOPTSTRING,opts,NULL);
 #else /* !HAVE_GETOPT_LONG */
 	    int c = getopt(argc,argv,SHORTOPTSTRING);
 #endif /* /HAVE_GETOPT_LONG */
 	    if(c==-1)
 		break;
 	    switch(c) {
 		case 'h':
 		    cerr << PHEADER << endl
 			<< PCOPY << endl << endl <<
 #ifdef HAVE_GETOPT_LONG
 			" -h, --help\n"
 			" --usage         display this text\n"
 			" -V, --version   display version number\n"
 			" -L, --license   show license\n"
 			" -f filename, --config=filename\n"
 			"                 specify the configuration file to use\n"
 			"\n"
 			" -k, --kill      stop running instance\n"
 			" -r, --reload    reload running instance (send SIGHUP)\n"
 			" -c, --check     check if dudki is running\n"
 			" -e, --ensure    ensure that dudki is running\n"
 			" -t, --test      test configuration file and exit"
 #else /* !HAVE_GETOPT_LONG */
 			" -h              display this text\n"
 			" -V              display version number\n"
 			" -L              show license\n"
 			" -f filename     specify the configuration file to use\n"
 			"\n"
 			" -k              stop running instance\n"
 			" -r              reload running instance (send SIGHUP)\n"
 			" -c              check if dudki is running\n"
 			" -e              ensure that dudki is running\n"
 			" -t              test configuration file and exit"
 #endif /* /HAVE_GETOPT_LONG */
 			<< endl;
 		    exit(0);
 		    break;
 		case 'V':
 		    cerr << VERSION << endl;
 		    exit(0);
 		    break;
 		case 'L':
 		    extern const char *COPYING;
 		    cerr << COPYING << endl;
 		    exit(0);
 		    break;
 		case 'f':
 		    config_file = optarg;
 		    break;
 		case 'k':
 		    if(op!=op_default) {
 			cerr << "Can't obey two or more orders at once" << endl;
 			exit(1);
 		    }
 		    op = op_term;
 		    break;
 		case 'r':
 		    if(op!=op_default) {
 			cerr << "Can't obey two or more orders at once" << endl;
 			exit(1);
 		    }
 		    op = op_hup;
 		    break;
 		case 'c':
 		    if(op!=op_default) {
 			cerr << "Can't obey two or more orders at once" << endl;
 			exit(1);
 		    }
 		    op = op_check;
 		    break;
 		case 'e':
 		    if(op!=op_default) {
 			cerr << "Can't obey two or more orders at once" << endl;
 			exit(1);
 		    }
 		    op = op_ensure;
 		    break;
 		case 't':
 		    if(op!=op_default) {
 			cerr << "Can't obey two or more orders at once" << endl;
 			exit(1);
 		    }
 		    op = op_test;
 		    break;
 		default:
 		    cerr << "Huh??" << endl;
 		    exit(1);
 		    break;
 	    }
 	}
 	const char *sid = *argv;
 	const char *t;
 	while(t = index(sid,'/')) {
 	    sid = t; sid++;
 	}
 	openlog(sid,LOG_CONS|LOG_PERROR|LOG_PID,LOG_DAEMON);
 	configuration config;
 	config.parse(config_file);
 	switch(op) {
 	    case op_test:
 		cerr << "Configuration OK" << endl;
 		break;
 	    case op_hup:
 		signal_self(config,SIGHUP);
 		break;
 	    case op_term:
 		signal_self(config,SIGTERM);
 		break;
 	    case op_check:
 		try{
 		    signal_self(config,0);
 		    exit(0);
 		}catch(exception& e) {
 		    exit(1);
 		}
 	    case op_ensure:
 		try {
 		    signal_self(config,0);
 		    break;
 		}catch(exception& e) {
 		    syslog(LOG_NOTICE,"The dudki process is down, taking its place");
 		    config.daemonize = true;
 		}catch(int zero) {
 		    // we throw zero in case we're ensuring that this very process is running.
 		    // we don't have to daemonize if we're daemonic.
 		    config.daemonize = false;
 		}
 	    case op_default:
 	    case op_work:
 		{
 		    if(config.daemonize) {
 			pid_t pf = fork();
 			if(pf<0)
 			    throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to fork()");
 			if(pf) {
 			    _exit(0);
 			}
 		    }
 		    pid_file pidfile;
 		    pidfile.set(config.pidfile);
 		    signal(SIGINT,lethal_signal_handler);
 		    signal(SIGABRT,lethal_signal_handler);
 		    signal(SIGTERM,lethal_signal_handler);
 		    signal(SIGHUP,sighup_handler);
+		    sigset_t sset;
+		    sigemptyset(&sset);
+		    sigaddset(&sset,SIGINT); sigaddset(&sset,SIGABRT);
+		    sigaddset(&sset,SIGTERM); sigaddset(&sset,SIGHUP);
+		    sigprocmask(SIG_UNBLOCK,&sset,NULL);
 		    while(!finishing) {
 			check_herd(config);
 			sleep(config.check_interval);
 		    }
 		}
 		break;
 	    default:
 		throw runtime_error(string(__PRETTY_FUNCTION__)+": internal error");
 	}
     }catch(exception& e) {
 	cerr << "Oops: " << e.what() << endl;
 	return 1;
     }
 }