summaryrefslogtreecommitdiff
path: root/support/dktools/dk4dmt.c
blob: 5e73c4e75c635782e9b7e6b05dbf589e001bb6a4 (plain)
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
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
/*
	WARNING: This file was generated by dkct.
	Changes you make here will be lost if dkct is run again!
	You should modify the original source and run dkct on it.
	Original source: dk4dmt.ctr
*/

/*
Copyright (C) 2016-2017, Dirk Krause

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above opyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
* Neither the name of the author nor the names of contributors may be used
  to endorse or promote products derived from this software without specific
  prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/**	@file dk4dmt.c The dk4dmt module.
*/


#line 101 "dk4dmt.ctr"


#include "dk4conf.h"

#include <stdio.h>

#if	DK4_HAVE_SYS_TYPES_H
#ifndef	SYS_TYPES_H_INCLUDED
#include <sys/types.h>
#define	SYS_TYPES_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_SYS_STAT_H
#ifndef	SYS_STAT_H_INCLUDED
#include <sys/stat.h>
#define	SYS_STAT_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_STDLIB_H
#ifndef	STDLIB_H_INCLUDED
#include <stdlib.h>
#define	STDLIB_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_UNISTD_H
#ifndef	UNISTD_H_INCLUDED
#include <unistd.h>
#define	UNISTD_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_FCNTL_H
#ifndef	FCNTL_H_INCLUDED
#include <fcntl.h>
#define	FCNTL_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_SIGNAL_H
#ifndef	SIGNAL_H_INCLUDED
#include <signal.h>
#define	SIGNAL_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_IO_H
#ifndef	IO_H_INCLUDED
#include <io.h>
#define	IO_H_INCLUDED 1
#endif
#endif

#if	DK4_HAVE_SYSLOG_H
#ifndef	SYSLOG_H_INCLUDED
#include <syslog.h>
#define	SYSLOG_H_INCLUDED 1
#endif
#endif

#include "dk4types.h"
#include "dk4dmt.h"
#include "dk4mem.h"
#include "dk4mao8d.h"
#include "dk4stat8.h"
#include "dk4str8.h"
#include "dk4fopc8.h"
#include "dk4mkdh8.h"





#line 175 "dk4dmt.ctr"



static const char * const	dk4dmt_kw[] = {
/* 0 */
"\n",

/* 1 */
": ",

/* 2 */
"Failed to create background process!",

/* 3 */
"Failed to detach from terminal (missing setsid()/setpgpr())!",

/* 4 */
"Failed to detach from terminal (setsid() failed)!",

/* 5 */
"Failed to create daemon process!",

/* 6 */
"Failed to reset signal handlers (sigemptyset)!",

/* 7 */
"Failed to reset signal handlers (sigaction)!",

/* 8 */
"Neither sigaction() nor sigset() available!",

/* 9 */
"Failed to unblock signals (sigemptyset)!",

/* 10 */
"Failed to unblock signals (sigprocmask)!",

/* 11 */
"PID file already exists:\n\"",

/* 12 */
"\"!",

/* 13 */
"Neither setsid() nor setpgrp() available!",

/* 14 */
"Failed to detach from terminal (setsid)!",

/* 15 */
"Failed to write PID file: \"",

/* 16 */
"\"!",

/* 17 */
"dk4dmt",

/* 18 */
"Failed to open /dev/null for read access!",

/* 19 */
"Failed to duplicate /dev/null to standard input!",

/* 20 */
"Failed to open /dev/null for write access!",

/* 21 */
"Failed to duplicate /dev/null to standard output!",

/* 22 */
"Failed to duplicate /dev/null to standard error output!",

/* 23 */
"Failed to change into root directory!",

/* 24 */
"Failed to remove PID file \"",

/* 25 */
"\"!",

NULL


#line 273 "dk4dmt.ctr"
};



static
void
dk4dmt_syslog_1(const char *prgname, int slf, size_t idx)
{
#if DK4_HAVE_SYSLOG
  openlog(((NULL != prgname) ? (prgname) : (dk4dmt_kw[17])), LOG_PID, slf);
  syslog(LOG_ERR, "%s", dk4dmt_kw[idx]);
  closelog();
#endif
}



static
void
dk4dmt_syslog_3(
  const char *prgname, int slf, size_t i1, size_t i2, const char *str
)
{
#if DK4_HAVE_SYSLOG
  openlog(((NULL != prgname) ? (prgname) : (dk4dmt_kw[17])), LOG_PID, slf);
  if (NULL != str) {
    syslog(LOG_ERR, "%s%s%s", dk4dmt_kw[i1], str, dk4dmt_kw[i2]);
  } else {
    syslog(LOG_ERR, "%s%s", dk4dmt_kw[i1], dk4dmt_kw[i2]);
  }
  closelog();
#endif
}



static
void
dk4dmt_log_1(const char *prgname, int slf, int lse, size_t i)
{
  if (0 != lse) {
    if (NULL != prgname) {
      fputs(prgname, stderr);
      fputs(dk4dmt_kw[1], stderr);
    }
    fputs(dk4dmt_kw[i], stderr);
    fputs(dk4dmt_kw[0], stderr);
    fflush(stderr);
  } else {
    dk4dmt_syslog_1(prgname, slf, i);
  }
}



static
void
dk4dmt_log_3(
  const char *prgname, int slf, int lse, size_t i1, size_t i2, const char *str
)
{
  if (0 != lse) {
    if (NULL != prgname) {
      fputs(prgname, stderr);
      fputs(dk4dmt_kw[1], stderr);
    }
    fputs(dk4dmt_kw[i1], stderr);
    if (NULL != str) { fputs(str, stderr); }
    fputs(dk4dmt_kw[i2], stderr);
    fputs(dk4dmt_kw[0], stderr);
    fflush(stderr);
  } else {
    dk4dmt_syslog_3(prgname, slf, i1, i2, str);
  }
}



/**	Reset all signals to SIG_DFL.
	@param	reason	Address of error code variable
	(1=sigemptyset failed, 2=sigaction failed, 3=no signal handling).
	@return	1 on success, 0 on error.
*/
static
int
dk4dmt_reset_all_signals(int *reason)
{
  

#line 361 "dk4dmt.ctr"
#if	DK4_HAVE_SIGACTION
  struct sigaction	sigact;		/* Signal information for sigaction() */
#endif
  int	back	= 1;			/* Function result */
  int	maxsig;				/* Maximum signal + 1 */
  int	i;				/* Current signal to modify */
  int	go;

#ifdef _NSIG
  maxsig = _NSIG;
#else
  maxsig = 16;
#endif

  for (i = 1; ((i < maxsig) && (1 == back)); i++) {
    go = 1;
#ifdef SIGKILL
    if (SIGKILL == i)	{ go = 0; }
#else
    if (9 == i)		{ go = 0; }
#endif
#ifdef SIGSTOP
    if (SIGSTOP == i)	{ go = 0; }
#else
    if (19 == i)	{ go = 0; }
#endif
    

#line 388 "dk4dmt.ctr"
    if (0 != go) {
#if	DK4_HAVE_SIGACTION
      DK4_MEMRES(&sigact, sizeof(sigact));
      sigact.sa_handler = SIG_DFL;
      sigact.sa_flags   = 0;
      if (0 != sigemptyset(&(sigact.sa_mask))) {
        if (16 > i) {
          back = 0;
	  if (NULL != reason) {	

#line 397 "dk4dmt.ctr"
	    *reason = 1;
	  }
	}
      }
      if (0 != sigaction(i, &sigact, NULL)) {
        if (16 > i) {
          back = 0;
	  if (NULL != reason) {	

#line 405 "dk4dmt.ctr"
	    *reason = 2;
	  }
	}
      }
#else
#if	DK4_HAVE_SIGSET
      sigset(i, SIG_DFL);
#else
#if	DK4_HAVE_SIGNAL
      signal(i, SIG_DFL);
#else
      back = 0;
      if (NULL != reason) { *reason = 3; }
#endif
#endif
#endif
    }
  }
  

#line 424 "dk4dmt.ctr"
  return back;
}



/**	Obtain maximum file descriptor number.
	@return	Maximum file descriptor.
*/
static
int
dk4dmt_max_file_descriptor(void)
{
#if DK4_HAVE_SYS_RESOURCE_H && DK4_HAVE_GETRLIMIT && defined(RLIMIT_NOFILE)
  struct rlimit		 rl;
#endif
  int		 back	= 1024;
#if DK4_HAVE_SYS_RESOURCE_H && DK4_HAVE_GETRLIMIT && defined(RLIMIT_NOFILE)
  if (0 == getrlimit(RLIMIT_NOFILE, &rl)) {
#if defined(RLIM_INFINITY)
    if (RLIM_INFINITY != rl.rlim_max) {
#endif
      back = rl.rlim_max;
#if defined(RLIM_INFINITY)
    }
#endif
  }
#endif
  return back;
}



/**	Close all file descriptors except 0 (stdin), 1 (stdout) and 2 (stderr).
*/
static
void
dk4dmt_close_non_std_file_descriptors(void)
{
  int	maxfd;
  int	fd;

  maxfd = dk4dmt_max_file_descriptor();
  for (fd = 3; fd < maxfd; fd++) {
    (void)close(fd);
  }
}



/**	Unblock all signals.
	@param	reason	Address of error code variable
	(1=sigemptyset failed, 2=sigprocmask failed).
	@return	1 on success, 0 on error.
*/
static
int
dk4dmt_unblock_all_signals(int *reason)
{
  sigset_t	set;
  int		back	= 1;
  if (0 != sigemptyset(&set)) {
    back = 0;
    if (NULL != reason) { *reason = 1; }
  }
  if (0 != sigprocmask(SIG_SETMASK, &set, NULL)) {
    back = 0;
    if (NULL != reason) { *reason = 2; }
  }
  return back;
}



int
dk4dmt_parent_before_fork(
  const char *prgname, const char *pidfilename, int logstderr, int slf
)
{
  dk4_stat_t	 stb;
  int		 reason	= 0;
  int		 back	= 1;

  /* Close file descriptors except 0, 1 and 2 */
  dk4dmt_close_non_std_file_descriptors();

  /* Reset all signal actions to default handlers */
  if (0 == dk4dmt_reset_all_signals(&reason)) {
    back = 0;
    if (0 != logstderr) {
      switch (reason) {
        case 1: {
	  /* ERROR: sigemptyset() failed */
	  dk4dmt_log_1(prgname, slf, logstderr, 6);
        } break;
        case 2: {
	  /* ERROR: sigaction() failed */
	  dk4dmt_log_1(prgname, slf, logstderr, 7);
        } break;
        default: {
	  /* ERROR: No sigaction()/sigset()/signal() function */
	  dk4dmt_log_1(prgname, slf, logstderr, 8);
        } break;
      }
    }
  }

  /* Unblock all signals */
  if (0 == dk4dmt_unblock_all_signals(&reason)) {
    back = 0;
    if (0 != logstderr) {
      switch (reason) {
        case 1: {
	  /* ERROR: sigemptyset() failed */
	  dk4dmt_log_1(prgname, slf, logstderr, 9);
	} break;
	case 2: {
	  /* ERROR: sigprocmask() failed */
	  dk4dmt_log_1(prgname, slf, logstderr, 10);
	} break;
      }
    }
  }

  if ((0 != back) && (NULL != pidfilename)) {
    if (0 != dk4stat_c8(&stb, pidfilename, NULL)) {
      back = 0;
      /* ERROR: PID file exists */
      dk4dmt_log_3(prgname, slf, logstderr, 11, 12, pidfilename);
    }
  }

  return back;
}


int
dk4dmt_intermediate_before_fork(const char *prgname, int slf)
{
  int		 back	= 1;
#if	DK4_HAVE_SETSID
  if ((pid_t)(-1) == setsid()) {
    back = 0;
    dk4dmt_syslog_1(prgname, slf, 14);
  }
#else
#if	DK4_HAVE_SETPGRP
  setpgrp();
#else
  back = 0;
  dk4dmt_syslog_1(prgname, slf, 13);
#endif
#endif
  return back;
}



int
dk4dmt_daemon_after_fork(const char *prgname, const char *pidfilename, int slf)
{
  char		 pidbuf[16*sizeof(dk4_um_t)];
  FILE		*fipo;
  int		 fdin;		/* File descriptor for input */
  int		 fdout;		/* File descriptor for output */
  int		 res;		/* Operation result */
  int		 back	= 1;

  if (NULL != pidfilename) {
    res = dk4ma_write_c8_decimal_unsigned(
      pidbuf, sizeof(pidbuf), (dk4_um_t)getpid(), 0, NULL
    );
    if (0 != res) {
      if (0 != dk4str8_cat_s(pidbuf, sizeof(pidbuf), dk4dmt_kw[0], NULL)) {
        (void)dk4mkdir_hierarchy_c8(pidfilename, 0, NULL);
        fipo = dk4fopen_c8(pidfilename, "w", DK4_FOPEN_SC_PRIVILEGED, NULL);
        if (NULL != fipo) {
          fputs(pidbuf, fipo);
          fclose(fipo);
        } else {
          dk4dmt_syslog_3(prgname, slf, 15, 16, pidfilename);
	  back = 0;
	}
      }
    }
  }

  /*	Connect /dev/null to stdin stout stderr or close them
  */
  fdin = open("/dev/null", O_RDONLY);
  if (-1 < fdin) {
    if (-1 == dup2(fdin, 0)) {
      back = 0;
      dk4dmt_syslog_1(prgname, slf, 19);
    }
    close(fdin);
  } else {
    back = 0;
    dk4dmt_syslog_1(prgname, slf, 18);
  }
  fdout = open("/dev/null", O_WRONLY);
  if (-1 < fdout) {
    if (-1 == dup2(fdout, 1)) {
      back = 0;
      dk4dmt_syslog_1(prgname, slf, 21);
    }
    if (-1 == dup2(fdout, 2)) {
      back = 0;
      dk4dmt_syslog_1(prgname, slf, 22);
    }
    close(fdout);
  } else {
    back = 0;
    dk4dmt_syslog_1(prgname, slf, 20);
  }

  /*	Use exact permissions when creating new files or directories.
  */
  umask(0);

  /*	Change to root directory, so the previous current directory
	can be unmounted without blocking.
  */
  if (0 != chdir("/")) {
    back = 0;
    dk4dmt_syslog_1(prgname, slf, 23);
  }

  /*	Indicate success or error.
  */
  return back;
}



void
dk4dmt_daemon_end(const char *prgname, const char *pidfilename, int slf)
{
  if (NULL != pidfilename) {
    if (0 != unlink(pidfilename)) {
      dk4dmt_syslog_3(prgname, slf, 24, 25, pidfilename);
    }
  }
}