projects/smsdaemon/daemon.cpp

#include <iostream>

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

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


#include "daemon.h"
#include "common.h"


using namespace std;


void signal_handler(int sig)
{
        switch (sig)
        {
        case SIGHUP:
                Common::instance()->logMessage("hangup signal catched");
                break;

        case SIGTERM:
                Common::instance()->logMessage("terminate signal catched...exiting");
                Common::instance()->mainContinue = false;
                break;
        }
}

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

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

        group* grp = getgrnam("smsdaemon");
        if (grp != 0)
        {
                cmn->gid = grp->gr_gid;
        }
        else
        {
                cmn->logMessage("could not lookup groupid: smsdaemon");
                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 */

        /*this program is now a daemon*/
        setegid( cmn->gid );
        seteuid( cmn->uid );
}
1	torben	26	#include <iostream>
2
3			#include <signal.h>
4			#include <fcntl.h>
5	torben	114	#include <stdlib.h>
6			#include <cstring>
7	torben	26
8	torben	146	#include <sys/types.h>
9			#include <pwd.h>
10			#include <grp.h>
11
12
13	torben	26	#include "daemon.h"
14			#include "common.h"
15
16
17
18			using namespace std;
19
20	torben	146
21	torben	26	void signal_handler(int sig)
22			{
23	torben	146	switch (sig)
24			{
25			case SIGHUP:
26			Common::instance()->logMessage("hangup signal catched");
27			break;
28	torben	26
29	torben	146	case SIGTERM:
30			Common::instance()->logMessage("terminate signal catched...exiting");
31			Common::instance()->mainContinue = false;
32			break;
33	torben	26	}
34			}
35
36	torben	146	void lookup_uid_values()
37			{
38			Common* cmn = Common::instance();
39
40			passwd* pass = getpwnam("smsdaemon");
41			if (pass != 0)
42			{
43			cmn->uid = pass->pw_uid;
44			}
45			else
46			{
47			cmn->logMessage("could not lookup userid: smsdaemon");
48			exit(1);
49			}
50
51			group* grp = getgrnam("smsdaemon");
52			if (grp != 0)
53			{
54			cmn->gid = grp->gr_gid;
55			}
56			else
57			{
58			cmn->logMessage("could not lookup groupid: smsdaemon");
59			exit(1);
60			}
61			}
62
63
64	torben	26	void daemonCleanup()
65			{
66			unlink( Common::instance()->pidfile.c_str() );
67			}
68
69			void daemonize()
70	torben	146	{
71	torben	26	int i, lfp;
72			char str[10];
73			Common* cmn = Common::instance();
74
75			if (getuid() != 0)
76			{
77			cout << "Please start this daemon as root\n" << endl;
78			daemon_shutdown(0);
79			}
80
81	torben	146
82	torben	26	if (getppid() == 1) /* already a daemon */
83			return;
84	torben	146
85	torben	26	i=fork();
86	torben	146
87	torben	26	if (i<0) /* fork error */
88			daemon_shutdown(FORK_ERROR);
89			if (i>0) /* parent exits */
90			daemon_shutdown(0);
91			/* child daemon continues */
92	torben	146
93	torben	26	setsid(); /* obtain a new process group */
94	torben	146
95	torben	26	for (i=getdtablesize(); i>=0; --i)
96			close(i); /close all descriptors/
97	torben	146
98	torben	26	i=open("/dev/null", O_RDWR); /* handle std. io */
99			dup(i);
100	torben	146	dup(i);
101
102	torben	26	umask(027); /* set newly created file permissions */
103	torben	146
104	torben	26	chdir("/tmp"); /* change running directory*/
105	torben	146
106	torben	26	/attempt to create lockfile and put a file-lock on it/
107			lfp=open(cmn->pidfile.c_str(), O_RDWR\|O_CREAT, 0640);
108			if (lfp<0) /* can not open */
109			daemon_shutdown(CANT_OPEN_LOCK);
110			if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */
111			daemon_shutdown(ALREADY_LOCKED);
112	torben	146
113	torben	26	/* first instance continues */
114			sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */
115			write(lfp, str, strlen(str) );
116	torben	86	//signal(SIGCHLD, SIG_IGN); /* ignore child */
117	torben	26	signal(SIGTSTP, SIG_IGN); /* ignore tty signals */
118			signal(SIGTTOU, SIG_IGN);
119			signal(SIGTTIN, SIG_IGN);
120			signal(SIGHUP, signal_handler); /* catch hangup signal */
121	torben	146	signal(SIGTERM, signal_handler); /* catch kill signal */
122	torben	26
123			/this program is now a daemon/
124			setegid( cmn->gid );
125			seteuid( cmn->uid );
126			}