1/***
2  This file is part of libdaemon.
3
4  Copyright 2003-2008 Lennart Poettering
5
6  Permission is hereby granted, free of charge, to any person obtaining a copy
7  of this software and associated documentation files (the "Software"), to deal
8  in the Software without restriction, including without limitation the rights
9  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  copies of the Software, and to permit persons to whom the Software is
11  furnished to do so, subject to the following conditions:
12
13  The above copyright notice and this permission notice shall be included in
14  all copies or substantial portions of the Software.
15
16  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  SOFTWARE.
23
24***/
25
26#include <signal.h>
27#include <errno.h>
28#include <string.h>
29#include <sys/types.h>
30#include <sys/time.h>
31#include <sys/unistd.h>
32#include <sys/select.h>
33
34#include <libdaemon/dfork.h>
35#include <libdaemon/dsignal.h>
36#include <libdaemon/dlog.h>
37#include <libdaemon/dpid.h>
38#include <libdaemon/dexec.h>
39
40int main(int argc, char *argv[]) {
41    pid_t pid;
42
43    /* Reset signal handlers */
44    if (daemon_reset_sigs(-1) < 0) {
45        daemon_log(LOG_ERR, "Failed to reset all signal handlers: %s", strerror(errno));
46        return 1;
47    }
48
49    /* Unblock signals */
50    if (daemon_unblock_sigs(-1) < 0) {
51        daemon_log(LOG_ERR, "Failed to unblock all signals: %s", strerror(errno));
52        return 1;
53    }
54
55    /* Set indetification string for the daemon for both syslog and PID file */
56    daemon_pid_file_ident = daemon_log_ident = daemon_ident_from_argv0(argv[0]);
57
58    /* Check if we are called with -k parameter */
59    if (argc >= 2 && !strcmp(argv[1], "-k")) {
60        int ret;
61
62        /* Kill daemon with SIGTERM */
63
64        /* Check if the new function daemon_pid_file_kill_wait() is available, if it is, use it. */
65        if ((ret = daemon_pid_file_kill_wait(SIGTERM, 5)) < 0)
66            daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
67
68        return ret < 0 ? 1 : 0;
69    }
70
71    /* Check that the daemon is not rung twice a the same time */
72    if ((pid = daemon_pid_file_is_running()) >= 0) {
73        daemon_log(LOG_ERR, "Daemon already running on PID file %u", pid);
74        return 1;
75    }
76
77    /* Prepare for return value passing from the initialization procedure of the daemon process */
78    if (daemon_retval_init() < 0) {
79        daemon_log(LOG_ERR, "Failed to create pipe.");
80        return 1;
81    }
82
83    /* Do the fork */
84    if ((pid = daemon_fork()) < 0) {
85
86        /* Exit on error */
87        daemon_retval_done();
88        return 1;
89
90    } else if (pid) { /* The parent */
91        int ret;
92
93        /* Wait for 20 seconds for the return value passed from the daemon process */
94        if ((ret = daemon_retval_wait(20)) < 0) {
95            daemon_log(LOG_ERR, "Could not recieve return value from daemon process: %s", strerror(errno));
96            return 255;
97        }
98
99        daemon_log(ret != 0 ? LOG_ERR : LOG_INFO, "Daemon returned %i as return value.", ret);
100        return ret;
101
102    } else { /* The daemon */
103        int fd, quit = 0;
104        fd_set fds;
105
106        /* Close FDs */
107        if (daemon_close_all(-1) < 0) {
108            daemon_log(LOG_ERR, "Failed to close all file descriptors: %s", strerror(errno));
109
110            /* Send the error condition to the parent process */
111            daemon_retval_send(1);
112            goto finish;
113        }
114
115        /* Create the PID file */
116        if (daemon_pid_file_create() < 0) {
117            daemon_log(LOG_ERR, "Could not create PID file (%s).", strerror(errno));
118            daemon_retval_send(2);
119            goto finish;
120        }
121
122        /* Initialize signal handling */
123        if (daemon_signal_init(SIGINT, SIGTERM, SIGQUIT, SIGHUP, 0) < 0) {
124            daemon_log(LOG_ERR, "Could not register signal handlers (%s).", strerror(errno));
125            daemon_retval_send(3);
126            goto finish;
127        }
128
129        /*... do some further init work here */
130
131
132        /* Send OK to parent process */
133        daemon_retval_send(0);
134
135        daemon_log(LOG_INFO, "Sucessfully started");
136
137        /* Prepare for select() on the signal fd */
138        FD_ZERO(&fds);
139        fd = daemon_signal_fd();
140        FD_SET(fd, &fds);
141
142        while (!quit) {
143            fd_set fds2 = fds;
144
145            /* Wait for an incoming signal */
146            if (select(FD_SETSIZE, &fds2, 0, 0, 0) < 0) {
147
148                /* If we've been interrupted by an incoming signal, continue */
149                if (errno == EINTR)
150                    continue;
151
152                daemon_log(LOG_ERR, "select(): %s", strerror(errno));
153                break;
154            }
155
156            /* Check if a signal has been recieved */
157            if (FD_ISSET(fd, &fds2)) {
158                int sig;
159
160                /* Get signal */
161                if ((sig = daemon_signal_next()) <= 0) {
162                    daemon_log(LOG_ERR, "daemon_signal_next() failed: %s", strerror(errno));
163                    break;
164                }
165
166                /* Dispatch signal */
167                switch (sig) {
168
169                    case SIGINT:
170                    case SIGQUIT:
171                    case SIGTERM:
172                        daemon_log(LOG_WARNING, "Got SIGINT, SIGQUIT or SIGTERM.");
173                        quit = 1;
174                        break;
175
176                    case SIGHUP:
177                        daemon_log(LOG_INFO, "Got a HUP");
178                        daemon_exec("/", NULL, "/bin/ls", "ls", (char*) NULL);
179                        break;
180
181                }
182            }
183        }
184
185        /* Do a cleanup */
186finish:
187        daemon_log(LOG_INFO, "Exiting...");
188        daemon_retval_send(255);
189        daemon_signal_done();
190        daemon_pid_file_remove();
191
192        return 0;
193    }
194}
195