projects/smsdaemon/daemon.cpp

#include <iostream>
#include <sstream>
#include <signal.h>
#include <fcntl.h>
#include <stdlib.h>
#include <cstring>

#include <sys/types.h>
#include <pwd.h>
#include <grp.h>


#include "ConfigFile.h"
#include "daemon.h"
#include "Common.h"
#include "Logger.h"


using namespace std;


void signal_handler(int sig)
{
        switch (sig)
        {
        case SIGHUP:
                Logger::logMessage("hangup signal catched");
                break;

        case SIGTERM:
                Logger::logMessage("terminate signal catched...exiting");
                Common::instance()->mainContinue = false;
                break;
        default:
                std::stringstream ss;
                ss << "Received unknown signal: " << sig;
                Logger::logMessage(ss.str());
                break;
        }
}

void lookup_uid_values()
{
        Common* cmn = Common::instance();

        std::string userstr = cmn->GetConfigfile()->GetValue("smsdaemon","user");
        std::string groupstr = cmn->GetConfigfile()->GetValue("smsdaemon","group");

        passwd* pass = getpwnam(userstr.c_str());
        if (pass != 0)
        {
                cmn->uid = pass->pw_uid;
        }
        else
        {
                Logger::logMessage( string("could not lookup userid: ") + userstr );
                exit(1);
        }


        group* grp = getgrnam(groupstr.c_str() );
        if (grp != 0)
        {
                cmn->gid = grp->gr_gid;
        }
        else
        {
                Logger::logMessage( string("could not lookup groupid: ") + groupstr );
                exit(1);
        }
}


void daemonCleanup()
{
        unlink( Common::instance()->pidfile.c_str() );
}

void daemonize()
{
        int i, lfp;
        char str[10];
        Common* cmn = Common::instance();

        if (getuid() != 0)
        {
                cout << "Please start this daemon as root\n" << endl;
                daemon_shutdown(0);
        }


        if (getppid() == 1) /* already a daemon */
                return;

        i=fork();

        if (i<0) /* fork error */
                daemon_shutdown(FORK_ERROR);
        if (i>0) /* parent exits */
                daemon_shutdown(0);
        /* child daemon continues */

        setsid(); /* obtain a new process group */

        for (i=getdtablesize(); i>=0; --i)
                close(i); /*close all descriptors*/

        i=open("/dev/null", O_RDWR); /* handle std. io */
        dup(i);
        dup(i);

        umask(027); /* set newly created file permissions */

        chdir("/tmp"); /* change running directory*/

        /*attempt to create lockfile and put a file-lock on it*/
        lfp=open(cmn->pidfile.c_str(), O_RDWR|O_CREAT, 0640);
        if (lfp<0) /* can not open */
                daemon_shutdown(CANT_OPEN_LOCK);
        if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */
                daemon_shutdown(ALREADY_LOCKED);

        /* first instance continues */
        sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */
        write(lfp, str, strlen(str) );
        //signal(SIGCHLD, SIG_IGN); /* ignore child */
        signal(SIGTSTP, SIG_IGN); /* ignore tty signals */
        signal(SIGTTOU, SIG_IGN);
        signal(SIGTTIN, SIG_IGN);
        signal(SIGHUP, signal_handler); /* catch hangup signal */
        signal(SIGTERM, signal_handler); /* catch kill signal */
        signal(SIGINT, signal_handler); /* keyboard interrupt */
        signal(SIGQUIT, signal_handler); /* QUIT */

        /*this program is now a daemon*/
        setegid( cmn->gid );
        seteuid( cmn->uid );
}
1	#include <iostream>
2	#include <sstream>
3	#include <signal.h>
4	#include <fcntl.h>
5	#include <stdlib.h>
6	#include <cstring>
7
8	#include <sys/types.h>
9	#include <pwd.h>
10	#include <grp.h>
11
12
13	#include "ConfigFile.h"
14	#include "daemon.h"
15	#include "Common.h"
16	#include "Logger.h"
17
18
19
20	using namespace std;
21
22
23	void signal_handler(int sig)
24	{
25	switch (sig)
26	{
27	case SIGHUP:
28	Logger::logMessage("hangup signal catched");
29	break;
30
31	case SIGTERM:
32	Logger::logMessage("terminate signal catched...exiting");
33	Common::instance()->mainContinue = false;
34	break;
35	default:
36	std::stringstream ss;
37	ss << "Received unknown signal: " << sig;
38	Logger::logMessage(ss.str());
39	break;
40	}
41	}
42
43	void lookup_uid_values()
44	{
45	Common* cmn = Common::instance();
46
47	std::string userstr = cmn->GetConfigfile()->GetValue("smsdaemon","user");
48	std::string groupstr = cmn->GetConfigfile()->GetValue("smsdaemon","group");
49
50	passwd* pass = getpwnam(userstr.c_str());
51	if (pass != 0)
52	{
53	cmn->uid = pass->pw_uid;
54	}
55	else
56	{
57	Logger::logMessage( string("could not lookup userid: ") + userstr );
58	exit(1);
59	}
60
61
62	group* grp = getgrnam(groupstr.c_str() );
63	if (grp != 0)
64	{
65	cmn->gid = grp->gr_gid;
66	}
67	else
68	{
69	Logger::logMessage( string("could not lookup groupid: ") + groupstr );
70	exit(1);
71	}
72	}
73
74
75	void daemonCleanup()
76	{
77	unlink( Common::instance()->pidfile.c_str() );
78	}
79
80	void daemonize()
81	{
82	int i, lfp;
83	char str[10];
84	Common* cmn = Common::instance();
85
86	if (getuid() != 0)
87	{
88	cout << "Please start this daemon as root\n" << endl;
89	daemon_shutdown(0);
90	}
91
92
93	if (getppid() == 1) /* already a daemon */
94	return;
95
96	i=fork();
97
98	if (i<0) /* fork error */
99	daemon_shutdown(FORK_ERROR);
100	if (i>0) /* parent exits */
101	daemon_shutdown(0);
102	/* child daemon continues */
103
104	setsid(); /* obtain a new process group */
105
106	for (i=getdtablesize(); i>=0; --i)
107	close(i); /close all descriptors/
108
109	i=open("/dev/null", O_RDWR); /* handle std. io */
110	dup(i);
111	dup(i);
112
113	umask(027); /* set newly created file permissions */
114
115	chdir("/tmp"); /* change running directory*/
116
117	/attempt to create lockfile and put a file-lock on it/
118	lfp=open(cmn->pidfile.c_str(), O_RDWR\|O_CREAT, 0640);
119	if (lfp<0) /* can not open */
120	daemon_shutdown(CANT_OPEN_LOCK);
121	if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */
122	daemon_shutdown(ALREADY_LOCKED);
123
124	/* first instance continues */
125	sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */
126	write(lfp, str, strlen(str) );
127	//signal(SIGCHLD, SIG_IGN); /* ignore child */
128	signal(SIGTSTP, SIG_IGN); /* ignore tty signals */
129	signal(SIGTTOU, SIG_IGN);
130	signal(SIGTTIN, SIG_IGN);
131	signal(SIGHUP, signal_handler); /* catch hangup signal */
132	signal(SIGTERM, signal_handler); /* catch kill signal */
133	signal(SIGINT, signal_handler); /* keyboard interrupt */
134	signal(SIGQUIT, signal_handler); /* QUIT */
135
136	/this program is now a daemon/
137	setegid( cmn->gid );
138	seteuid( cmn->uid );
139	}