Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
/*	$NetBSD: ntp_filegen.c,v 1.8 2016/01/08 21:35:39 christos Exp $	*/

/*
 * ntp_filegen.c,v 3.12 1994/01/25 19:06:11 kardel Exp
 *
 *  implements file generations support for NTP
 *  logfiles and statistic files
 *
 *
 * Copyright (C) 1992, 1996 by Rainer Pruy
 * Friedrich-Alexander Universitaet Erlangen-Nuernberg, Germany
 *
 * This code may be modified and used freely
 * provided credits remain intact.
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_string.h"
#include "ntp_calendar.h"
#include "ntp_filegen.h"
#include "ntp_stdlib.h"

/*
 * NTP is intended to run long periods of time without restart.
 * Thus log and statistic files generated by NTP will grow large.
 *
 * this set of routines provides a central interface 
 * to generating files using file generations
 *
 * the generation of a file is changed according to file generation type
 */


/*
 * redefine this if your system dislikes filename suffixes like
 * X.19910101 or X.1992W50 or ....
 */
#define SUFFIX_SEP '.'

static	void	filegen_open	(FILEGEN *, u_int32, const time_t*);
static	int	valid_fileref	(const char *, const char *);
static	void	filegen_init	(const char *, const char *, FILEGEN *);
#ifdef	DEBUG
static	void	filegen_uninit		(FILEGEN *);
#endif	/* DEBUG */


/*
 * filegen_init
 */

static void
filegen_init(
	const char *	dir,
	const char *	fname,
	FILEGEN *	fgp
	)
{
	fgp->fp = NULL;
	fgp->dir = estrdup(dir);
	fgp->fname = estrdup(fname);
	fgp->id_lo = 0;
	fgp->id_hi = 0;
	fgp->type = FILEGEN_DAY;
	fgp->flag = FGEN_FLAG_LINK; /* not yet enabled !!*/
}


/*
 * filegen_uninit - free memory allocated by filegen_init
 */
#ifdef DEBUG
static void
filegen_uninit(
	FILEGEN *fgp
	)
{
	free(fgp->dir);
	free(fgp->fname);
}
#endif


/*
 * open a file generation according to the current settings of gen
 * will also provide a link to basename if requested to do so
 */

static void
filegen_open(
	FILEGEN *	gen,
	u_int32		stamp,
	const time_t *	pivot
	)
{
	char *savename;	/* temp store for name collision handling */
	char *fullname;	/* name with any designation extension */
	char *filename;	/* name without designation extension */
	char *suffix;	/* where to print suffix extension */
	u_int len, suflen;
	FILE *fp;
	struct calendar cal;
	struct isodate	iso;

	/* get basic filename in buffer, leave room for extensions */
	len = strlen(gen->dir) + strlen(gen->fname) + 65;
	filename = emalloc(len);
	fullname = emalloc(len);
	savename = NULL;
	snprintf(filename, len, "%s%s", gen->dir, gen->fname);

	/* where to place suffix */
	suflen = strlcpy(fullname, filename, len);
	suffix = fullname + suflen;
	suflen = len - suflen;

	/* last octet of fullname set to '\0' for truncation check */
	fullname[len - 1] = '\0';

	switch (gen->type) {

	default:
		msyslog(LOG_ERR, 
			"unsupported file generations type %d for "
			"\"%s\" - reverting to FILEGEN_NONE",
			gen->type, filename);
		gen->type = FILEGEN_NONE;
		break;

	case FILEGEN_NONE:
		/* no suffix, all set */
		break;

	case FILEGEN_PID:
		gen->id_lo = getpid();
		gen->id_hi = 0;
		snprintf(suffix, suflen, "%c#%ld",
			 SUFFIX_SEP, gen->id_lo);
		break;

	case FILEGEN_DAY:
		/*
		 * You can argue here in favor of using MJD, but I
		 * would assume it to be easier for humans to interpret
		 * dates in a format they are used to in everyday life.
		 */
		ntpcal_ntp_to_date(&cal, stamp, pivot);
		snprintf(suffix, suflen, "%c%04d%02d%02d",
			 SUFFIX_SEP, cal.year, cal.month, cal.monthday);
		cal.hour = cal.minute = cal.second = 0;
		gen->id_lo = ntpcal_date_to_ntp(&cal); 
		gen->id_hi = (u_int32)(gen->id_lo + SECSPERDAY);
		break;

	case FILEGEN_WEEK:
		isocal_ntp_to_date(&iso, stamp, pivot);
		snprintf(suffix, suflen, "%c%04dw%02d",
			 SUFFIX_SEP, iso.year, iso.week);
		iso.hour = iso.minute = iso.second = 0;
		iso.weekday = 1;
		gen->id_lo = isocal_date_to_ntp(&iso);
		gen->id_hi = (u_int32)(gen->id_lo + 7 * SECSPERDAY);
		break;

	case FILEGEN_MONTH:
		ntpcal_ntp_to_date(&cal, stamp, pivot);
		snprintf(suffix, suflen, "%c%04d%02d",
			 SUFFIX_SEP, cal.year, cal.month);
		cal.hour = cal.minute = cal.second = 0;
		cal.monthday = 1;
		gen->id_lo = ntpcal_date_to_ntp(&cal); 
		cal.month++;
		gen->id_hi = ntpcal_date_to_ntp(&cal); 
		break;

	case FILEGEN_YEAR:
		ntpcal_ntp_to_date(&cal, stamp, pivot);
		snprintf(suffix, suflen, "%c%04d",
			 SUFFIX_SEP, cal.year);
		cal.hour = cal.minute = cal.second = 0;
		cal.month = cal.monthday = 1;
		gen->id_lo = ntpcal_date_to_ntp(&cal); 
		cal.year++;
		gen->id_hi = ntpcal_date_to_ntp(&cal); 
		break;

	case FILEGEN_AGE:
		gen->id_lo = current_time - (current_time % SECSPERDAY);
		gen->id_hi = gen->id_lo + SECSPERDAY;
		snprintf(suffix, suflen, "%ca%08ld",
			 SUFFIX_SEP, gen->id_lo);
	}
  
	/* check possible truncation */
	if ('\0' != fullname[len - 1]) {
		fullname[len - 1] = '\0';
		msyslog(LOG_ERR, "logfile name truncated: \"%s\"",
			fullname);
	}

	if (FILEGEN_NONE != gen->type) {
		/*
		 * check for existence of a file with name 'basename'
		 * as we disallow such a file
		 * if FGEN_FLAG_LINK is set create a link
		 */
		struct stat stats;
		/*
		 * try to resolve name collisions
		 */
		static u_long conflicts = 0;

#ifndef	S_ISREG
#define	S_ISREG(mode)	(((mode) & S_IFREG) == S_IFREG)
#endif
		if (stat(filename, &stats) == 0) {
			/* Hm, file exists... */
			if (S_ISREG(stats.st_mode)) {
				if (stats.st_nlink <= 1)	{
					/*
					 * Oh, it is not linked - try to save it
					 */
					savename = emalloc(len);
					snprintf(savename, len,
						"%s%c%dC%lu",
						filename, SUFFIX_SEP,
						(int)getpid(), conflicts++);

					if (rename(filename, savename) != 0)
						msyslog(LOG_ERR,
							"couldn't save %s: %m",
							filename);
					free(savename);
				} else {
					/*
					 * there is at least a second link to
					 * this file.
					 * just remove the conflicting one
					 */
					if (
#if !defined(VMS)
						unlink(filename) != 0
#else
						delete(filename) != 0
#endif
						)
						msyslog(LOG_ERR, 
							"couldn't unlink %s: %m",
							filename);
				}
			} else {
				/*
				 * Ehh? Not a regular file ?? strange !!!!
				 */
				msyslog(LOG_ERR, 
					"expected regular file for %s "
					"(found mode 0%lo)",
					filename,
					(unsigned long)stats.st_mode);
			}
		} else {
			/*
			 * stat(..) failed, but it is absolutely correct for
			 * 'basename' not to exist
			 */
			if (ENOENT != errno)
				msyslog(LOG_ERR, "stat(%s) failed: %m",
						 filename);
		}
	}

	/*
	 * now, try to open new file generation...
	 */
	DPRINTF(4, ("opening filegen (type=%d/stamp=%u) \"%s\"\n",
		    gen->type, stamp, fullname));

	fp = fopen(fullname, "a");
  
	if (NULL == fp)	{
		/* open failed -- keep previous state
		 *
		 * If the file was open before keep the previous generation.
		 * This will cause output to end up in the 'wrong' file,
		 * but I think this is still better than losing output
		 *
		 * ignore errors due to missing directories
		 */

		if (ENOENT != errno)
			msyslog(LOG_ERR, "can't open %s: %m", fullname);
	} else {
		if (NULL != gen->fp) {
			fclose(gen->fp);
			gen->fp = NULL;
		}
		gen->fp = fp;

		if (gen->flag & FGEN_FLAG_LINK) {
			/*
			 * need to link file to basename
			 * have to use hardlink for now as I want to allow
			 * gen->basename spanning directory levels
			 * this would make it more complex to get the correct
			 * fullname for symlink
			 *
			 * Ok, it would just mean taking the part following
			 * the last '/' in the name.... Should add it later....
			 */

			/* Windows NT does not support file links -Greg Schueman 1/18/97 */

#if defined(SYS_WINNT) || defined(SYS_VXWORKS)
			SetLastError(0); /* On WinNT, don't support FGEN_FLAG_LINK */
#elif defined(VMS)
			errno = 0; /* On VMS, don't support FGEN_FLAG_LINK */
#else  /* not (VMS) / VXWORKS / WINNT ; DO THE LINK) */
			if (link(fullname, filename) != 0)
				if (EEXIST != errno)
					msyslog(LOG_ERR, 
						"can't link(%s, %s): %m",
						fullname, filename);
#endif /* SYS_WINNT || VXWORKS */
		}		/* flags & FGEN_FLAG_LINK */
	}			/* else fp == NULL */
	
	free(filename);
	free(fullname);
	return;
}

/*
 * this function sets up gen->fp to point to the correct
 * generation of the file for the time specified by 'now'
 *
 * 'now' usually is interpreted as second part of a l_fp as is in the cal...
 * library routines
 */

void
filegen_setup(
	FILEGEN *	gen,
	u_int32		now
	)
{
	int	current;
	time_t	pivot;

	if (!(gen->flag & FGEN_FLAG_ENABLED)) {
		if (NULL != gen->fp) {
			fclose(gen->fp);
			gen->fp = NULL;
		}
		return;
	}

	switch (gen->type) {

	default:
	case FILEGEN_NONE:
		current = TRUE;
		break;

	case FILEGEN_PID:
		current = ((int)gen->id_lo == getpid());
		break;

	case FILEGEN_AGE:
		current = (gen->id_lo <= current_time) &&
			  (gen->id_hi > current_time);
		break;

	case FILEGEN_DAY:
	case FILEGEN_WEEK:
	case FILEGEN_MONTH:
	case FILEGEN_YEAR:
		current = (gen->id_lo <= now) &&
			  (gen->id_hi > now);
		break;
	}
	/*
	 * try to open file if not yet open
	 * reopen new file generation file on change of generation id
	 */
	if (NULL == gen->fp || !current) {
		DPRINTF(1, ("filegen  %0x %u\n", gen->type, now));
		pivot = time(NULL);
		filegen_open(gen, now, &pivot);
	}
}


/*
 * change settings for filegen files
 */
void
filegen_config(
	FILEGEN *	gen,
	const char *	dir,
	const char *	fname,
	u_int		type,
	u_int		flag
	)
{
	int file_existed;
	l_fp now;


	/*
	 * if nothing would be changed...
	 */
	if (strcmp(dir, gen->dir) == 0 && strcmp(fname, gen->fname) == 0
	    && type == gen->type && flag == gen->flag)
		return;

	/*
	 * validate parameters
	 */
	if (!valid_fileref(dir, fname))
		return;
  
	if (NULL != gen->fp) {
		fclose(gen->fp);
		gen->fp = NULL;
		file_existed = TRUE;
	} else {
		file_existed = FALSE;
	}

	DPRINTF(3, ("configuring filegen:\n"
		    "\tdir:\t%s -> %s\n"
		    "\tfname:\t%s -> %s\n"
		    "\ttype:\t%d -> %d\n"
		    "\tflag: %x -> %x\n",
		    gen->dir, dir,
		    gen->fname, fname,
		    gen->type, type,
		    gen->flag, flag));

	if (strcmp(gen->dir, dir) != 0) {
		free(gen->dir);
		gen->dir = estrdup(dir);
	}

	if (strcmp(gen->fname, fname) != 0) {
		free(gen->fname);
		gen->fname = estrdup(fname);
	}
	gen->type = (u_char)type;
	gen->flag = (u_char)flag;

	/*
	 * make filegen use the new settings
	 * special action is only required when a generation file
	 * is currently open
	 * otherwise the new settings will be used anyway at the next open
	 */
	if (file_existed) {
		get_systime(&now);
		filegen_setup(gen, now.l_ui);
	}
}


/*
 * check whether concatenating prefix and basename
 * yields a legal filename
 */
static int
valid_fileref(
	const char *	dir,
	const char *	fname
	)
{
	/*
	 * dir cannot be changed dynamically
	 * (within the context of filegen)
	 * so just reject basenames containing '..'
	 *
	 * ASSUMPTION:
	 *		file system parts 'below' dir may be
	 *		specified without infringement of security
	 *
	 *		restricting dir to legal values
	 *		has to be ensured by other means
	 * (however, it would be possible to perform some checks here...)
	 */
	const char *p;

	/*
	 * Just to catch, dumb errors opening up the world...
	 */
	if (NULL == dir || '\0' == dir[0])
		return FALSE;

	if (NULL == fname)
		return FALSE;

#ifdef SYS_WINNT
	/*
	 * Windows treats / equivalent to \, reject any / to ensure
	 * check below for DIR_SEP (\ on windows) are adequate.
	 */
	if (strchr(fname, '/')) {
		msyslog(LOG_ERR,
			"filegen filenames must not contain '/': %s",
			fname);
		return FALSE;
	}
#endif

	for (p = fname; p != NULL; p = strchr(p, DIR_SEP)) {
		if ('.' == p[0] && '.' == p[1] 
		    && ('\0' == p[2] || DIR_SEP == p[2]))
			return FALSE;
	}

	return TRUE;
}


/*
 * filegen registry
 */

static struct filegen_entry {
	char *			name;
	FILEGEN *		filegen;
	struct filegen_entry *	next;
} *filegen_registry = NULL;


FILEGEN *
filegen_get(
	const char *	name
	)
{
	struct filegen_entry *f = filegen_registry;

	while (f) {
		if (f->name == name || strcmp(name, f->name) == 0) {
			DPRINTF(4, ("filegen_get(%s) = %p\n",
				    name, f->filegen));
			return f->filegen;
		}
		f = f->next;
	}
	DPRINTF(4, ("filegen_get(%s) = NULL\n", name));
	return NULL;
}


void
filegen_register(
	const char *	dir,
	const char *	name,
	FILEGEN *	filegen
	)
{
	struct filegen_entry **ppfe;

	DPRINTF(4, ("filegen_register(%s, %p)\n", name, filegen));

	filegen_init(dir, name, filegen);

	ppfe = &filegen_registry;
	while (NULL != *ppfe) {
		if ((*ppfe)->name == name 
		    || !strcmp((*ppfe)->name, name)) {

			DPRINTF(5, ("replacing filegen %p\n",
				    (*ppfe)->filegen));

			(*ppfe)->filegen = filegen;
			return;
		}
		ppfe = &((*ppfe)->next);
	}

	*ppfe = emalloc(sizeof **ppfe);

	(*ppfe)->next = NULL;
	(*ppfe)->name = estrdup(name);
	(*ppfe)->filegen = filegen;

	DPRINTF(6, ("adding new filegen\n"));
	
	return;
}


/*
 * filegen_statsdir() - reset each filegen entry's dir to statsdir.
 */
void
filegen_statsdir(void)
{
	struct filegen_entry *f;

	for (f = filegen_registry; f != NULL; f = f->next)
		filegen_config(f->filegen, statsdir, f->filegen->fname,
			       f->filegen->type, f->filegen->flag);
}


/*
 * filegen_unregister frees memory allocated by filegen_register for
 * name.
 */
#ifdef DEBUG
void
filegen_unregister(
	const char *name
	)
{
	struct filegen_entry **	ppfe;
	struct filegen_entry *	pfe;
	FILEGEN *		fg;
			
	DPRINTF(4, ("filegen_unregister(%s)\n", name));

	ppfe = &filegen_registry;

	while (NULL != *ppfe) {
		if ((*ppfe)->name == name
		    || !strcmp((*ppfe)->name, name)) {
			pfe = *ppfe;
			*ppfe = (*ppfe)->next;
			fg = pfe->filegen;
			free(pfe->name);
			free(pfe);
			filegen_uninit(fg);
			break;
		}
		ppfe = &((*ppfe)->next);
	}
}	
#endif	/* DEBUG */