File: runit.c

package info (click to toggle)
runit 2.1.2-9.2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 1,660 kB
  • ctags: 1,087
  • sloc: ansic: 5,701; sh: 664; makefile: 361
file content (351 lines) | stat: -rw-r--r-- 9,051 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
#include <sys/types.h>
#include <sys/reboot.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include "runit.h"
#include "sig.h"
#include "strerr.h"
#include "error.h"
#include "iopause.h"
#include "coe.h"
#include "ndelay.h"
#include "wait.h"
#include "open.h"
#include "reboot_system.h"

/* #define DEBUG */

#define INFO "- runit: "
#define WARNING "- runit: warning: "
#define FATAL "- runit: fatal: "

const char * const stage[3] ={
  "/etc/runit/1",
  "/etc/runit/2",
  "/etc/runit/3" };

int selfpipe[2];
int sigc =0;
int sigi =0;

void sig_cont_handler (void) {
  sigc++;
  write(selfpipe[1], "", 1);
}
void sig_int_handler (void) {
  sigi++;
  write(selfpipe[1], "", 1);
}
void sig_child_handler (void) { write(selfpipe[1], "", 1); }

void sync_if_needed() {
  struct stat s;
  if (stat(NOSYNC, &s) == -1) sync();
}

int main (int argc, const char * const *argv, char * const *envp) {
  const char * prog[2];
  int pid, pid2;
  int wstat;
  int st;
  iopause_fd x;
#ifndef IOPAUSE_POLL
  fd_set rfds;
  struct timeval t;
#endif
  char ch;
  int ttyfd;
  struct stat s;

  if (getpid() != 1) strerr_die2x(111, FATAL, "must be run as process no 1.");
  setsid();

  sig_block(sig_alarm);
  sig_block(sig_child);
  sig_catch(sig_child, sig_child_handler);
  sig_block(sig_cont);
  sig_catch(sig_cont, sig_cont_handler);
  sig_block(sig_hangup);
  sig_block(sig_int);
  sig_catch(sig_int, sig_int_handler);
  sig_block(sig_pipe);
  sig_block(sig_term);

  /* console */
  if ((ttyfd =open_write("/dev/console")) != -1) {
    dup2(ttyfd, 0); dup2(ttyfd, 1); dup2(ttyfd, 2);
    if (ttyfd > 2) close(ttyfd);
  }

  /* create selfpipe */
  while (pipe(selfpipe) == -1) {
    strerr_warn2(FATAL, "unable to create selfpipe, pausing: ", &strerr_sys);
    sleep(5);
  }
  coe(selfpipe[0]);
  coe(selfpipe[1]);
  ndelay_on(selfpipe[0]);
  ndelay_on(selfpipe[1]);

#ifdef RB_DISABLE_CAD
  /* activate ctrlaltdel handling, glibc, dietlibc */
  if (RB_DISABLE_CAD == 0) reboot_system(0);
#endif

  strerr_warn3(INFO, "$Id: 25da3b86f7bed4038b8a039d2f8e8c9bbcf0822b $",
               ": booting.", 0);

  /* runit */
  for (st =0; st < 3; st++) {
    /* if (st == 2) logwtmp("~", "reboot", ""); */
    while ((pid =fork()) == -1) {
      strerr_warn4(FATAL, "unable to fork for \"", stage[st], "\" pausing: ",
                   &strerr_sys);
      sleep(5);
    }
    if (!pid) {
      /* child */
      prog[0] =stage[st];
      prog[1] =0;

      /* stage 1 gets full control of console */
      if (st == 0) {
        if ((ttyfd =open("/dev/console", O_RDWR)) != -1) {
#ifdef TIOCSCTTY 
          ioctl(ttyfd, TIOCSCTTY, (char *)0);
#endif
          dup2(ttyfd, 0);
          if (ttyfd > 2) close(ttyfd);
        }
        else
          strerr_warn2(WARNING, "unable to open /dev/console: ", &strerr_sys);
      }
      else
        setsid();

      sig_unblock(sig_alarm);
      sig_unblock(sig_child);
      sig_uncatch(sig_child);
      sig_unblock(sig_cont);
      sig_ignore(sig_cont);
      sig_unblock(sig_hangup);
      sig_unblock(sig_int);
      sig_uncatch(sig_int);
      sig_unblock(sig_pipe);
      sig_unblock(sig_term);
            
      strerr_warn3(INFO, "enter stage: ", stage[st], 0);
      execve(*prog, (char *const *)prog, envp);
      strerr_die4sys(0, FATAL, "unable to start child: ", stage[st], ": ");
    }

    x.fd =selfpipe[0];
    x.events =IOPAUSE_READ;
    for (;;) {
      int child;

      sig_unblock(sig_child);
      sig_unblock(sig_cont);
      sig_unblock(sig_int);
#ifdef IOPAUSE_POLL
      poll(&x, 1, 14000);
#else
      t.tv_sec =14; t.tv_usec =0;
      FD_ZERO(&rfds);
      FD_SET(x.fd, &rfds);
      select(x.fd +1, &rfds, (fd_set*)0, (fd_set*)0, &t);
#endif
      sig_block(sig_cont);
      sig_block(sig_child);
      sig_block(sig_int);
      
      while (read(selfpipe[0], &ch, 1) == 1) {}
      while ((child =wait_nohang(&wstat)) > 0)
        if (child == pid) break;
      if (child == -1) {
        strerr_warn2(WARNING, "wait_nohang, pausing: ", &strerr_sys);
        sleep(5);
      }

      /* reget stderr */
      if ((ttyfd =open_write("/dev/console")) != -1) {
        dup2(ttyfd, 2);
        if (ttyfd > 2) close(ttyfd);
      }

      if (child == pid) {
        if (wait_exitcode(wstat) != 0) {
          if (wait_crashed(wstat))
            strerr_warn3(WARNING, "child crashed: ", stage[st], 0);
          else
            strerr_warn3(WARNING, "child failed: ", stage[st], 0);
          if (st == 0)
            /* this is stage 1 */
            if (wait_crashed(wstat) || (wait_exitcode(wstat) == 100)) {
              strerr_warn3(INFO, "leave stage: ", stage[st], 0);
              strerr_warn2(WARNING, "skipping stage 2...", 0);
              st++;
              break;
            }
          if (st == 1)
            /* this is stage 2 */
            if (wait_crashed(wstat) || (wait_exitcode(wstat) == 111)) {
              strerr_warn2(WARNING, "killing all processes in stage 2...", 0);
              kill(-pid, 9);
              sleep(5);
              strerr_warn2(WARNING, "restarting.", 0);
              st--;
              break;
            }
        }
        strerr_warn3(INFO, "leave stage: ", stage[st], 0);
        break;
      }
      if (child != 0) {
        /* collect terminated children */
        write(selfpipe[1], "", 1);
        continue;
      }

      /* sig? */
      if (!sigc  && !sigi) {
#ifdef DEBUG
        strerr_warn2(WARNING, "poll: ", &strerr_sys);
#endif
        continue;
      }
      if (st != 1) {
        strerr_warn2(WARNING, "signals only work in stage 2.", 0);
        sigc =sigi =0;
        continue;
      }
      if (sigi && (stat(CTRLALTDEL, &s) != -1) && (s.st_mode & S_IXUSR)) {
        strerr_warn2(INFO, "ctrl-alt-del request...", 0);
        prog[0] =CTRLALTDEL; prog[1] =0;
        while ((pid2 =fork()) == -1) {
          strerr_warn4(FATAL, "unable to fork for \"", CTRLALTDEL,
                       "\" pausing: ", &strerr_sys);
          sleep(5);
        }
        if (!pid2) {
          /* child */
          strerr_warn3(INFO, "enter stage: ", prog[0], 0);
          execve(*prog, (char *const *) prog, envp);
          strerr_die4sys(0, FATAL, "unable to start child: ", prog[0], ": ");
        }
        if (wait_pid(&wstat, pid2) == -1)
          strerr_warn2(FATAL, "wait_pid: ", &strerr_sys);
        if (wait_crashed(wstat))
          strerr_warn3(WARNING, "child crashed: ", CTRLALTDEL, 0);
        strerr_warn3(INFO, "leave stage: ", prog[0], 0);
        sigi =0;
        sigc++;
      }
      if (sigc && (stat(STOPIT, &s) != -1) && (s.st_mode & S_IXUSR)) {
        int i;
        /* unlink(STOPIT); */
        chmod(STOPIT, 0);

        /* kill stage 2 */
#ifdef DEBUG
        strerr_warn2(WARNING, "sending sigterm...", 0);
#endif
        kill(pid, sig_term);
        i =0;
        while (i < 5) {
          if ((child =wait_nohang(&wstat)) == pid) {
#ifdef DEBUG
            strerr_warn2(WARNING, "stage 2 terminated.", 0);
#endif
            pid =0;
            break;
          }
          if (child) continue;
          if (child == -1) 
            strerr_warn2(WARNING, "wait_nohang: ", &strerr_sys);
#ifdef DEBUG
          strerr_warn2(WARNING, "waiting...", 0);
#endif
          sleep(1);
          i++;
        }
        if (pid) {
          /* still there */
          strerr_warn2(WARNING,
                       "stage 2 not terminated, sending sigkill...", 0);
          kill(pid, 9);
          if (wait_pid(&wstat, pid) == -1)
            strerr_warn2(WARNING, "wait_pid: ", &strerr_sys);
        }
        sigc =0;
        strerr_warn3(INFO, "leave stage: ", stage[st], 0);

        /* enter stage 3 */
        break;
      }
      sigc =sigi =0;
#ifdef DEBUG
      strerr_warn2(WARNING, "no request.", 0);
#endif
    }
  }

  /* reget stderr */
  if ((ttyfd =open_write("/dev/console")) != -1) {
    dup2(ttyfd, 2);
    if (ttyfd > 2) close(ttyfd);
  }

#ifdef RB_AUTOBOOT
  /* fallthrough stage 3 */
  strerr_warn2(INFO, "sending KILL signal to all processes...", 0);
  kill(-1, SIGKILL);

  pid =fork();
  switch (pid) {
  case  0:
  case -1:
  if ((stat(REBOOT, &s) != -1) && (s.st_mode & S_IXUSR)) {
    strerr_warn2(INFO, "system reboot.", 0);
    sync_if_needed();
    reboot_system(RB_AUTOBOOT);
  }
  else {
#ifdef RB_POWER_OFF
    strerr_warn2(INFO, "power off...", 0);
    sync_if_needed();
    reboot_system(RB_POWER_OFF);
    sleep(2);
#endif
#ifdef RB_HALT_SYSTEM
    strerr_warn2(INFO, "system halt.", 0);
    sync_if_needed();
    reboot_system(RB_HALT_SYSTEM);
#else
#ifdef RB_HALT
    strerr_warn2(INFO, "system halt.", 0);
    sync_if_needed();
    reboot_system(RB_HALT);
#else
    strerr_warn2(INFO, "system reboot.", 0);
    sync_if_needed();
    reboot_system(RB_AUTOBOOT);
#endif
#endif
  }
  if (pid == 0) _exit(0);
  break;
  default:
  sig_unblock(sig_child);
  while (wait_pid(0, pid) == -1);
  }
#endif

  for (;;) sig_pause();
  /* not reached */
  strerr_die2x(0, INFO, "exit.");
  return(0);
}