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 "ConfigFile.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();

        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
        {
                cmn->logMessage( string("could not lookup userid: ") + userstr );
                exit(1);
        }

        group* grp = getgrnam(groupstr.c_str() );
        if (grp != 0)
        {
                cmn->gid = grp->gr_gid;
        }
        else
        {
                cmn->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 */

        /*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	152	#include "ConfigFile.h"
14	torben	26	#include "daemon.h"
15			#include "common.h"
16
17
18
19			using namespace std;
20
21	torben	146
22	torben	26	void signal_handler(int sig)
23			{
24	torben	146	switch (sig)
25			{
26			case SIGHUP:
27			Common::instance()->logMessage("hangup signal catched");
28			break;
29	torben	26
30	torben	146	case SIGTERM:
31			Common::instance()->logMessage("terminate signal catched...exiting");
32			Common::instance()->mainContinue = false;
33			break;
34	torben	26	}
35			}
36
37	torben	146	void lookup_uid_values()
38			{
39			Common* cmn = Common::instance();
40
41	torben	152	std::string userstr = cmn->GetConfigfile()->GetValue("smsdaemon","user");
42			std::string groupstr = cmn->GetConfigfile()->GetValue("smsdaemon","group");
43
44			passwd* pass = getpwnam(userstr.c_str());
45	torben	146	if (pass != 0)
46			{
47			cmn->uid = pass->pw_uid;
48			}
49			else
50			{
51	torben	152	cmn->logMessage( string("could not lookup userid: ") + userstr );
52	torben	146	exit(1);
53			}
54
55	torben	152	group* grp = getgrnam(groupstr.c_str() );
56	torben	146	if (grp != 0)
57			{
58			cmn->gid = grp->gr_gid;
59			}
60			else
61			{
62	torben	152	cmn->logMessage( string("could not lookup groupid: ") + groupstr );
63	torben	146	exit(1);
64			}
65			}
66
67
68	torben	26	void daemonCleanup()
69			{
70			unlink( Common::instance()->pidfile.c_str() );
71			}
72
73			void daemonize()
74	torben	146	{
75	torben	26	int i, lfp;
76			char str[10];
77			Common* cmn = Common::instance();
78
79			if (getuid() != 0)
80			{
81			cout << "Please start this daemon as root\n" << endl;
82			daemon_shutdown(0);
83			}
84
85	torben	146
86	torben	26	if (getppid() == 1) /* already a daemon */
87			return;
88	torben	146
89	torben	26	i=fork();
90	torben	146
91	torben	26	if (i<0) /* fork error */
92			daemon_shutdown(FORK_ERROR);
93			if (i>0) /* parent exits */
94			daemon_shutdown(0);
95			/* child daemon continues */
96	torben	146
97	torben	26	setsid(); /* obtain a new process group */
98	torben	146
99	torben	26	for (i=getdtablesize(); i>=0; --i)
100			close(i); /close all descriptors/
101	torben	146
102	torben	26	i=open("/dev/null", O_RDWR); /* handle std. io */
103			dup(i);
104	torben	146	dup(i);
105
106	torben	26	umask(027); /* set newly created file permissions */
107	torben	146
108	torben	26	chdir("/tmp"); /* change running directory*/
109	torben	146
110	torben	26	/attempt to create lockfile and put a file-lock on it/
111			lfp=open(cmn->pidfile.c_str(), O_RDWR\|O_CREAT, 0640);
112			if (lfp<0) /* can not open */
113			daemon_shutdown(CANT_OPEN_LOCK);
114			if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */
115			daemon_shutdown(ALREADY_LOCKED);
116	torben	146
117	torben	26	/* first instance continues */
118			sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */
119			write(lfp, str, strlen(str) );
120	torben	86	//signal(SIGCHLD, SIG_IGN); /* ignore child */
121	torben	26	signal(SIGTSTP, SIG_IGN); /* ignore tty signals */
122			signal(SIGTTOU, SIG_IGN);
123			signal(SIGTTIN, SIG_IGN);
124			signal(SIGHUP, signal_handler); /* catch hangup signal */
125	torben	146	signal(SIGTERM, signal_handler); /* catch kill signal */
126	torben	26
127			/this program is now a daemon/
128			setegid( cmn->gid );
129			seteuid( cmn->uid );
130			}