1 /*
2 * Copyright (c) 1997, 1999 Hellmuth Michaelis. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 *---------------------------------------------------------------------------
26 *
27 * i4b daemon - process handling routines
28 * --------------------------------------
29 *
30 * $Id: process.c,v 1.3 2003/10/06 09:43:27 itojun Exp $
31 *
32 * $FreeBSD$
33 *
34 * last edit-date: [Mon Dec 13 21:48:19 1999]
35 *
36 *---------------------------------------------------------------------------*/
37
38 #include "isdnd.h"
39
40 /*---------------------------------------------------------------------------*
41 * check if another instance of us is already running
42 *---------------------------------------------------------------------------*/
43 void
check_pid(void)44 check_pid(void)
45 {
46 FILE *fp;
47
48 /* check if another lock-file already exists */
49
50 if ((fp = fopen(PIDFILE, "r")) != NULL)
51 {
52 /* lockfile found, check */
53
54 int oldpid;
55
56 /* read pid from file */
57
58 if ((fscanf(fp, "%d", &oldpid)) != 1)
59 {
60 logit(LL_ERR, "ERROR, reading pid from lockfile failed, terminating!");
61 exit(1);
62 }
63
64 /* check if process got from file is still alive */
65
66 if ((kill(oldpid, 0)) != 0)
67 {
68 /* process does not exist */
69
70 /* close file */
71
72 fclose(fp);
73
74 DBGL(DL_PROC, (logit(LL_DBG, "removing old lock-file %s", PIDFILE)));
75
76 /* remove file */
77
78 unlink(PIDFILE);
79 }
80 else
81 {
82 /* process is still alive */
83
84 logit(LL_ERR, "ERROR, another daemon is already running, pid = %d, terminating!", oldpid);
85 exit(1);
86 }
87 }
88 }
89
90 /*---------------------------------------------------------------------------*
91 * establish and init process lock file
92 *---------------------------------------------------------------------------*/
93 void
write_pid(void)94 write_pid(void)
95 {
96 FILE *fp;
97
98 /* write my pid into lock-file */
99
100 if ((fp = fopen(PIDFILE, "w")) == NULL)
101 {
102 logit(LL_ERR, "ERROR, can't open lockfile for writing, terminating");
103 do_exit(1);
104 }
105
106 if ((fprintf(fp, "%d", (int)getpid())) == EOF)
107 {
108 logit(LL_ERR, "ERROR, can't write pid to lockfile, terminating");
109 do_exit(1);
110 }
111
112 fsync(fileno(fp));
113
114 fclose(fp);
115 }
116
117 /*---------------------------------------------------------------------------*
118 * become a daemon
119 *---------------------------------------------------------------------------*/
120 void
daemonize(void)121 daemonize(void)
122 {
123 int fd;
124
125 switch (fork())
126 {
127 case -1: /* error */
128 logit(LL_ERR, "ERROR, daemonize/fork: %s", strerror(errno));
129 exit(1);
130 case 0: /* child */
131 break;
132 default: /* parent */
133 exit(0);
134 }
135
136 /* new session / no control tty */
137
138 if (setsid() == -1)
139 {
140 logit(LL_ERR, "ERROR, setsid returns: %s", strerror(errno));
141 exit(1);
142 }
143
144 /* go away from mounted dir */
145
146 chdir("/");
147
148 /* move i/o to another device ? */
149
150 if (do_fullscreen && do_rdev)
151 {
152 char *tp;
153
154 if ((fd = open(rdev, O_RDWR, 0)) != -1)
155 {
156 if (!isatty(fd))
157 {
158 logit(LL_ERR, "ERROR, device %s is not a tty!", rdev);
159 exit(1);
160 }
161 if ((dup2(fd, STDIN_FILENO)) == -1)
162 {
163 logit(LL_ERR, "ERROR, dup2 stdin: %s", strerror(errno));
164 exit(1);
165 }
166 if ((dup2(fd, STDOUT_FILENO)) == -1)
167 {
168 logit(LL_ERR, "ERROR, dup2 stdout: %s", strerror(errno));
169 exit(1);
170 }
171 if ((dup2(fd, STDERR_FILENO)) == -1)
172 {
173 logit(LL_ERR, "ERROR, dup2 stderr: %s", strerror(errno));
174 exit(1);
175 }
176 }
177 else
178 {
179 logit(LL_ERR, "ERROR, cannot open redirected device: %s", strerror(errno));
180 exit(1);
181 }
182
183 if (fd > 2)
184 {
185 if ((close(fd)) == -1)
186 {
187 logit(LL_ERR, "ERROR, close in daemonize: %s", strerror(errno));
188 exit(1);
189 }
190 }
191
192 /* curses output && fork NEEDS controlling tty */
193
194 if ((ioctl(STDIN_FILENO, TIOCSCTTY, (char *)NULL)) < 0)
195 {
196 logit(LL_ERR, "ERROR, cannot setup tty as controlling terminal: %s", strerror(errno));
197 exit(1);
198 }
199
200 /* in case there is no environment ... */
201
202 if (((tp = getenv("TERM")) == NULL) || (*tp == '\0'))
203 {
204 if (do_ttytype == 0)
205 {
206 logit(LL_ERR, "ERROR, no environment variable TERM found and -t not specified!");
207 exit(1);
208 }
209
210 if ((setenv("TERM", ttype, 1)) != 0)
211 {
212 logit(LL_ERR, "ERROR, setenv TERM=%s failed: %s", ttype, strerror(errno));
213 exit(1);
214 }
215 }
216 }
217 }
218
219 /* EOF */
220