d9898ee8 |
1 | /* |
2 | ** Copyright 2000-2006 Double Precision, Inc. See COPYING for |
3 | ** distribution information. |
4 | */ |
5 | |
6 | #include "config.h" |
7 | #include "liblock.h" |
8 | #include <stdio.h> |
9 | #include <signal.h> |
10 | #include <stdlib.h> |
11 | #include <string.h> |
12 | #include <unistd.h> |
13 | #include <ctype.h> |
14 | #include <errno.h> |
15 | #if HAVE_FCNTL_H |
16 | #include <fcntl.h> |
17 | #endif |
18 | #include <sys/types.h> |
19 | #include "../numlib/numlib.h" |
20 | #if HAVE_SYS_WAIT_H |
21 | #include <sys/wait.h> |
22 | #endif |
23 | #ifndef WEXITSTATUS |
24 | #define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8) |
25 | #endif |
26 | #ifndef WIFEXITED |
27 | #define WIFEXITED(stat_val) (((stat_val) & 255) == 0) |
28 | #endif |
29 | #if HAVE_SYS_IOCTL_H |
30 | #include <sys/ioctl.h> |
31 | #endif |
32 | |
33 | #define exit(_a_) _exit(_a_) |
34 | |
35 | static const char rcsid[]="$Id: lockdaemon.c,v 1.10 2006/05/28 15:29:52 mrsam Exp $"; |
36 | |
37 | static int start1(const char *, int); |
38 | |
39 | #define CONSOLE "/dev/null" |
40 | |
41 | int ll_daemon_start(const char *lockfile) |
42 | { |
43 | pid_t p; |
44 | int pipefd[2]; |
45 | char c; |
46 | int i; |
47 | |
48 | /* |
49 | ** Close any open file descriptors. |
50 | */ |
51 | |
52 | for (i=3; i < 256; i++) |
53 | close(i); |
54 | |
55 | /* |
56 | ** We fork, and set up a pipe from the child process. If we read |
57 | ** a single 0 byte from the pipe, it means that the child has |
58 | ** succesfully initialized, and will return to main, so we exit(0). |
59 | ** If we do not read a single 0 byte from the pipe, it means that |
60 | ** there was an initialization error, so we return -1 to main. |
61 | */ |
62 | |
63 | if (pipe(pipefd) < 0) |
64 | { |
65 | perror("pipe"); |
66 | return (-1); |
67 | } |
68 | |
69 | if ((p=fork()) == -1) |
70 | { |
71 | close(pipefd[0]); |
72 | close(pipefd[1]); |
73 | perror("fork"); |
74 | return (-1); |
75 | } |
76 | |
77 | if (p == 0) |
78 | { |
79 | close(pipefd[0]); |
80 | |
81 | /* |
82 | ** We fork once more, so that the daemon process will not |
83 | ** be the child process of anyone. |
84 | */ |
85 | |
86 | p=fork(); |
87 | if (p == -1) |
88 | { |
89 | perror("fork"); |
90 | exit(0); |
91 | } |
92 | if (p) |
93 | exit(0); |
94 | |
95 | /* |
96 | ** Continue initialization in start1() |
97 | */ |
98 | return (start1(lockfile, pipefd[1])); |
99 | } |
100 | |
101 | close(pipefd[1]); |
102 | if (read(pipefd[0], &c, 1) <= 0) |
103 | c=1; |
104 | close(pipefd[0]); |
105 | if (c == 0) |
106 | exit (0); /* Successful start of daemon */ |
107 | errno=EAGAIN; |
108 | return (-1); |
109 | } |
110 | |
111 | static int start1(const char *lockfile, int fd) |
112 | { |
113 | int lockfd; |
114 | |
115 | #if HAVE_SETPGRP |
116 | #if SETPGRP_VOID |
117 | setpgrp(); |
118 | #else |
119 | setpgrp(0, 0); |
120 | #endif |
121 | #endif |
122 | #ifdef TIOCNOTTY |
123 | |
124 | { |
125 | int fd=open("/dev/tty", O_RDWR); |
126 | |
127 | if (fd >= 0) |
128 | { |
129 | ioctl(fd, TIOCNOTTY, 0); |
130 | close(fd); |
131 | } |
132 | } |
133 | #endif |
134 | |
135 | |
136 | /* Attempt to obtain a lock */ |
137 | |
138 | lockfd=open(lockfile, O_RDWR|O_CREAT, 0600); |
139 | |
140 | if (lockfd < 0) |
141 | { |
142 | /* Perhaps an upgraded daemon runs under new uid? */ |
143 | |
144 | unlink(lockfile); |
145 | lockfd=open(lockfile, O_RDWR|O_CREAT, 0600); |
146 | } |
147 | |
148 | if (lockfd < 0) |
149 | { |
150 | perror(lockfile); |
151 | exit(1); |
152 | } |
153 | |
154 | #ifdef FD_CLOEXEC |
155 | if (fcntl(lockfd, F_SETFD, FD_CLOEXEC) < 0) |
156 | { |
157 | perror("fcntl"); |
158 | close(lockfd); |
159 | exit(1); |
160 | } |
161 | #endif |
162 | |
163 | if (ll_lock_ex_test(lockfd)) |
164 | { |
165 | if (write(fd, "", 1) != 1) |
166 | exit(1); /* Shouldn't happen */ |
167 | |
168 | close(fd); |
169 | exit (0); /* Already running, pretend success */ |
170 | } |
171 | |
172 | /* |
173 | ** Return >0 to main, so it can continue main's setup. |
174 | */ |
175 | |
176 | return (fd); |
177 | } |
178 | |
179 | int ll_daemon_resetio() |
180 | { |
181 | int i; |
182 | |
183 | close(0); |
184 | if (open("/dev/null", O_RDONLY) != 0) |
185 | return (-1); |
186 | |
187 | close(1); |
188 | i=open(CONSOLE, O_WRONLY); |
189 | if (i < 0) i=open("/dev/null", O_WRONLY); |
190 | if (i != 1) return (-1); |
191 | |
192 | close(2); |
193 | i=open(CONSOLE, O_WRONLY); |
194 | if (i < 0) i=open("/dev/null", O_WRONLY); |
195 | if (i != 2) return (-1); |
196 | return (0); |
197 | } |
198 | |
199 | void ll_daemon_started(const char *pidfile, int fd) |
200 | { |
201 | char buf[NUMBUFSIZE+1]; |
202 | char *p=strcat(libmail_str_pid_t(getpid(), buf), "\n"); |
203 | FILE *fp; |
204 | |
205 | unlink(pidfile); |
206 | if ((fp=fopen(pidfile, "w")) == NULL || |
207 | fprintf(fp, "%s", p) < 0 || fflush(fp) < 0 || fclose(fp)) |
208 | { |
209 | perror(pidfile); |
210 | exit(1); |
211 | } |
212 | |
213 | if (write(fd, "", 1) != 1) /* Signal waiting parent */ |
214 | exit(1); /* Shouldn't happen */ |
215 | close(fd); |
216 | } |
217 | |
218 | static void stop1(const char *, const char *); |
219 | |
220 | int ll_daemon_stop(const char *lockfile, const char *pidfile) |
221 | { |
222 | pid_t p, p2; |
223 | int waitstat; |
224 | |
225 | /* |
226 | ** We fork, and the child process attempts to stop the daemon, |
227 | ** then communicates the success to us, via its exit code. |
228 | */ |
229 | |
230 | signal(SIGCHLD, SIG_DFL); |
231 | if ((p=fork()) == -1) |
232 | { |
233 | perror("fork"); |
234 | return (1); |
235 | } |
236 | if (p == 0) stop1(lockfile, pidfile); |
237 | |
238 | while ((p2=wait(&waitstat)) != p) |
239 | ; |
240 | |
241 | if (WIFEXITED(waitstat)) |
242 | return (WEXITSTATUS(waitstat)); |
243 | return (0); |
244 | } |
245 | |
246 | /* |
247 | ** The child process forks too. The parent process goes in a loop, |
248 | ** trying to kill the daemon process. |
249 | ** |
250 | ** The child process attempts to lock the lock file. When it |
251 | ** succeeds, it exits. When the child process exits, the parent |
252 | ** process kills itself. |
253 | */ |
254 | |
255 | static RETSIGTYPE sigexit(int signum) |
256 | { |
257 | kill(getpid(), SIGKILL); |
258 | #if RETSIGTYPE != void |
259 | return (0); |
260 | #endif |
261 | } |
262 | |
263 | static void stop1(const char *lockfile, const char *pidfile) |
264 | { |
265 | int lockfd; |
266 | pid_t p; |
267 | |
268 | if ((lockfd=open(lockfile, O_RDWR|O_CREAT, 0600)) < 0) |
269 | { |
270 | perror(lockfile); |
271 | exit(1); |
272 | } |
273 | |
274 | if ( ll_lock_ex_test(lockfd) == 0) /* No daemon process running */ |
275 | { |
276 | close(lockfd); |
277 | exit (0); /* That was easy! */ |
278 | } |
279 | |
280 | signal(SIGCHLD, sigexit); |
281 | |
282 | if ((p=fork()) == -1) |
283 | { |
284 | perror("fork"); |
285 | exit(1); |
286 | } |
287 | |
288 | if (p) /* Parent - first sends a SIGTERM, then a SIGKILL */ |
289 | { |
290 | int signum=SIGTERM; |
291 | |
292 | close(lockfd); |
293 | for (;; sleep(10)) |
294 | { |
295 | FILE *fp; |
296 | int c; |
297 | |
298 | if ((fp=fopen(pidfile, "r")) == NULL) |
299 | continue; |
300 | |
301 | p=0; |
302 | |
303 | while ((c=getc(fp)) != EOF && c != '\n') |
304 | { |
305 | if (isdigit(c)) |
306 | p=p*10+(c-'0'); |
307 | } |
308 | |
309 | fclose(fp); |
310 | if (p) |
311 | kill(p, signum); |
312 | signum=SIGKILL; |
313 | } |
314 | } |
315 | |
316 | if (ll_lock_ex(lockfd)) |
317 | perror("lock"); |
318 | close(lockfd); |
319 | exit(0); |
320 | } |
321 | |
322 | int ll_daemon_restart(const char *lockfile, const char *pidfile) |
323 | { |
324 | int lockfd; |
325 | pid_t p; |
326 | FILE *fp; |
327 | int c; |
328 | |
329 | if ((lockfd=open(lockfile, O_RDWR|O_CREAT, 0600)) < 0) |
330 | { |
331 | perror(lockfile); |
332 | return (1); |
333 | } |
334 | |
335 | if ( ll_lock_ex_test(lockfd) == 0) /* No daemon process running */ |
336 | { |
337 | close(lockfd); |
338 | return (0); /* That was easy! */ |
339 | } |
340 | close(lockfd); |
341 | |
342 | if ((fp=fopen(pidfile, "r")) == NULL) |
343 | return (0); |
344 | |
345 | p=0; |
346 | |
347 | while ((c=getc(fp)) != EOF && c != '\n') |
348 | { |
349 | if (isdigit(c)) |
350 | p=p*10+(c-'0'); |
351 | } |
352 | |
353 | fclose(fp); |
354 | if (p) |
355 | kill(p, SIGHUP); |
356 | return (0); |
357 | } |
358 | |