1/***
2  This file is part of libdaemon.
3
4  Copyright 2003-2008 Lennart Poettering
5
6  libdaemon is free software; you can redistribute it and/or modify
7  it under the terms of the GNU Lesser General Public License as
8  published by the Free Software Foundation, either version 2.1 of the
9  License, or (at your option) any later version.
10
11  libdaemon is distributed in the hope that it will be useful, but
12  WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  Lesser General Public License for more details.
15
16  You should have received a copy of the GNU Lesser General Public
17  License along with libdaemon. If not, see
18  <http://www.gnu.org/licenses/>.
19***/
20
21#include <signal.h>
22#include <errno.h>
23#include <string.h>
24#include <sys/types.h>
25#include <sys/time.h>
26#include <sys/unistd.h>
27#include <sys/select.h>
28
29#include <libdaemon/dfork.h>
30#include <libdaemon/dsignal.h>
31#include <libdaemon/dlog.h>
32#include <libdaemon/dpid.h>
33#include <libdaemon/dexec.h>
34
35int main(int argc, char *argv[]) {
36    pid_t pid;
37
38    /* Reset signal handlers */
39    if (daemon_reset_sigs(-1) < 0) {
40        daemon_log(LOG_ERR, "Failed to reset all signal handlers: %s", strerror(errno));
41        return 1;
42    }
43
44    /* Unblock signals */
45    if (daemon_unblock_sigs(-1) < 0) {
46        daemon_log(LOG_ERR, "Failed to unblock all signals: %s", strerror(errno));
47        return 1;
48    }
49
50    /* Set indetification string for the daemon for both syslog and PID file */
51    daemon_pid_file_ident = daemon_log_ident = daemon_ident_from_argv0(argv[0]);
52
53    /* Check if we are called with -k parameter */
54    if (argc >= 2 && !strcmp(argv[1], "-k")) {
55        int ret;
56
57        /* Kill daemon with SIGTERM */
58
59        /* Check if the new function daemon_pid_file_kill_wait() is available, if it is, use it. */
60        if ((ret = daemon_pid_file_kill_wait(SIGTERM, 5)) < 0)
61            daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
62
63        return ret < 0 ? 1 : 0;
64    }
65
66    /* Check that the daemon is not rung twice a the same time */
67    if ((pid = daemon_pid_file_is_running()) >= 0) {
68        daemon_log(LOG_ERR, "Daemon already running on PID file %u", pid);
69        return 1;
70    }
71
72    /* Prepare for return value passing from the initialization procedure of the daemon process */
73    if (daemon_retval_init() < 0) {
74        daemon_log(LOG_ERR, "Failed to create pipe.");
75        return 1;
76    }
77
78    /* Do the fork */
79    if ((pid = daemon_fork()) < 0) {
80
81        /* Exit on error */
82        daemon_retval_done();
83        return 1;
84
85    } else if (pid) { /* The parent */
86        int ret;
87
88        /* Wait for 20 seconds for the return value passed from the daemon process */
89        if ((ret = daemon_retval_wait(20)) < 0) {
90            daemon_log(LOG_ERR, "Could not recieve return value from daemon process: %s", strerror(errno));
91            return 255;
92        }
93
94        daemon_log(ret != 0 ? LOG_ERR : LOG_INFO, "Daemon returned %i as return value.", ret);
95        return ret;
96
97    } else { /* The daemon */
98        int fd, quit = 0;
99        fd_set fds;
100
101        /* Close FDs */
102        if (daemon_close_all(-1) < 0) {
103            daemon_log(LOG_ERR, "Failed to close all file descriptors: %s", strerror(errno));
104
105            /* Send the error condition to the parent process */
106            daemon_retval_send(1);
107            goto finish;
108        }
109
110        /* Create the PID file */
111        if (daemon_pid_file_create() < 0) {
112            daemon_log(LOG_ERR, "Could not create PID file (%s).", strerror(errno));
113            daemon_retval_send(2);
114            goto finish;
115        }
116
117        /* Initialize signal handling */
118        if (daemon_signal_init(SIGINT, SIGTERM, SIGQUIT, SIGHUP, 0) < 0) {
119            daemon_log(LOG_ERR, "Could not register signal handlers (%s).", strerror(errno));
120            daemon_retval_send(3);
121            goto finish;
122        }
123
124        /*... do some further init work here */
125
126
127        /* Send OK to parent process */
128        daemon_retval_send(0);
129
130        daemon_log(LOG_INFO, "Sucessfully started");
131
132        /* Prepare for select() on the signal fd */
133        FD_ZERO(&fds);
134        fd = daemon_signal_fd();
135        FD_SET(fd, &fds);
136
137        while (!quit) {
138            fd_set fds2 = fds;
139
140            /* Wait for an incoming signal */
141            if (select(FD_SETSIZE, &fds2, 0, 0, 0) < 0) {
142
143                /* If we've been interrupted by an incoming signal, continue */
144                if (errno == EINTR)
145                    continue;
146
147                daemon_log(LOG_ERR, "select(): %s", strerror(errno));
148                break;
149            }
150
151            /* Check if a signal has been recieved */
152            if (FD_ISSET(fd, &fds2)) {
153                int sig;
154
155                /* Get signal */
156                if ((sig = daemon_signal_next()) <= 0) {
157                    daemon_log(LOG_ERR, "daemon_signal_next() failed: %s", strerror(errno));
158                    break;
159                }
160
161                /* Dispatch signal */
162                switch (sig) {
163
164                    case SIGINT:
165                    case SIGQUIT:
166                    case SIGTERM:
167                        daemon_log(LOG_WARNING, "Got SIGINT, SIGQUIT or SIGTERM.");
168                        quit = 1;
169                        break;
170
171                    case SIGHUP:
172                        daemon_log(LOG_INFO, "Got a HUP");
173                        daemon_exec("/", NULL, "/bin/ls", "ls", (char*) NULL);
174                        break;
175
176                }
177            }
178        }
179
180        /* Do a cleanup */
181finish:
182        daemon_log(LOG_INFO, "Exiting...");
183        daemon_retval_send(255);
184        daemon_signal_done();
185        daemon_pid_file_remove();
186
187        return 0;
188    }
189}
190