xref: /netbsd-src/external/bsd/ntp/dist/ntpd/ntp_filegen.c (revision cdfa2a7ef92791ba9db70a584a1d904730e6fb46)
1 /*	$NetBSD: ntp_filegen.c,v 1.9 2020/05/25 20:47:25 christos Exp $	*/
2 
3 /*
4  * ntp_filegen.c,v 3.12 1994/01/25 19:06:11 kardel Exp
5  *
6  *  implements file generations support for NTP
7  *  logfiles and statistic files
8  *
9  *
10  * Copyright (C) 1992, 1996 by Rainer Pruy
11  * Friedrich-Alexander Universitaet Erlangen-Nuernberg, Germany
12  *
13  * This code may be modified and used freely
14  * provided credits remain intact.
15  */
16 
17 #ifdef HAVE_CONFIG_H
18 # include <config.h>
19 #endif
20 
21 #include <stdio.h>
22 #include <sys/types.h>
23 #include <sys/stat.h>
24 
25 #include "ntpd.h"
26 #include "ntp_io.h"
27 #include "ntp_string.h"
28 #include "ntp_calendar.h"
29 #include "ntp_filegen.h"
30 #include "ntp_stdlib.h"
31 
32 /*
33  * NTP is intended to run long periods of time without restart.
34  * Thus log and statistic files generated by NTP will grow large.
35  *
36  * this set of routines provides a central interface
37  * to generating files using file generations
38  *
39  * the generation of a file is changed according to file generation type
40  */
41 
42 
43 /*
44  * redefine this if your system dislikes filename suffixes like
45  * X.19910101 or X.1992W50 or ....
46  */
47 #define SUFFIX_SEP '.'
48 
49 static	void	filegen_open	(FILEGEN *, u_int32, const time_t*);
50 static	int	valid_fileref	(const char *, const char *);
51 static	void	filegen_init	(const char *, const char *, FILEGEN *);
52 #ifdef	DEBUG
53 static	void	filegen_uninit		(FILEGEN *);
54 #endif	/* DEBUG */
55 
56 
57 /*
58  * filegen_init
59  */
60 
61 static void
filegen_init(const char * dir,const char * fname,FILEGEN * fgp)62 filegen_init(
63 	const char *	dir,
64 	const char *	fname,
65 	FILEGEN *	fgp
66 	)
67 {
68 	fgp->fp = NULL;
69 	fgp->dir = estrdup(dir);
70 	fgp->fname = estrdup(fname);
71 	fgp->id_lo = 0;
72 	fgp->id_hi = 0;
73 	fgp->type = FILEGEN_DAY;
74 	fgp->flag = FGEN_FLAG_LINK; /* not yet enabled !!*/
75 }
76 
77 
78 /*
79  * filegen_uninit - free memory allocated by filegen_init
80  */
81 #ifdef DEBUG
82 static void
filegen_uninit(FILEGEN * fgp)83 filegen_uninit(
84 	FILEGEN *fgp
85 	)
86 {
87 	free(fgp->dir);
88 	free(fgp->fname);
89 }
90 #endif
91 
92 
93 /*
94  * open a file generation according to the current settings of gen
95  * will also provide a link to basename if requested to do so
96  */
97 
98 static void
filegen_open(FILEGEN * gen,u_int32 stamp,const time_t * pivot)99 filegen_open(
100 	FILEGEN *	gen,
101 	u_int32		stamp,
102 	const time_t *	pivot
103 	)
104 {
105 	char *savename;	/* temp store for name collision handling */
106 	char *fullname;	/* name with any designation extension */
107 	char *filename;	/* name without designation extension */
108 	char *suffix;	/* where to print suffix extension */
109 	u_int len, suflen;
110 	FILE *fp;
111 	struct calendar cal;
112 	struct isodate	iso;
113 
114 	/* get basic filename in buffer, leave room for extensions */
115 	len = strlen(gen->dir) + strlen(gen->fname) + 65;
116 	filename = emalloc(len);
117 	fullname = emalloc(len);
118 	savename = NULL;
119 	snprintf(filename, len, "%s%s", gen->dir, gen->fname);
120 
121 	/* where to place suffix */
122 	suflen = strlcpy(fullname, filename, len);
123 	suffix = fullname + suflen;
124 	suflen = len - suflen;
125 
126 	/* last octet of fullname set to '\0' for truncation check */
127 	fullname[len - 1] = '\0';
128 
129 	switch (gen->type) {
130 
131 	default:
132 		msyslog(LOG_ERR,
133 			"unsupported file generations type %d for "
134 			"\"%s\" - reverting to FILEGEN_NONE",
135 			gen->type, filename);
136 		gen->type = FILEGEN_NONE;
137 		break;
138 
139 	case FILEGEN_NONE:
140 		/* no suffix, all set */
141 		break;
142 
143 	case FILEGEN_PID:
144 		gen->id_lo = getpid();
145 		gen->id_hi = 0;
146 		snprintf(suffix, suflen, "%c#%ld",
147 			 SUFFIX_SEP, gen->id_lo);
148 		break;
149 
150 	case FILEGEN_DAY:
151 		/*
152 		 * You can argue here in favor of using MJD, but I
153 		 * would assume it to be easier for humans to interpret
154 		 * dates in a format they are used to in everyday life.
155 		 */
156 		ntpcal_ntp_to_date(&cal, stamp, pivot);
157 		snprintf(suffix, suflen, "%c%04d%02d%02d",
158 			 SUFFIX_SEP, cal.year, cal.month, cal.monthday);
159 		cal.hour = cal.minute = cal.second = 0;
160 		gen->id_lo = ntpcal_date_to_ntp(&cal);
161 		gen->id_hi = (u_int32)(gen->id_lo + SECSPERDAY);
162 		break;
163 
164 	case FILEGEN_WEEK:
165 		isocal_ntp_to_date(&iso, stamp, pivot);
166 		snprintf(suffix, suflen, "%c%04dw%02d",
167 			 SUFFIX_SEP, iso.year, iso.week);
168 		iso.hour = iso.minute = iso.second = 0;
169 		iso.weekday = 1;
170 		gen->id_lo = isocal_date_to_ntp(&iso);
171 		gen->id_hi = (u_int32)(gen->id_lo + 7 * SECSPERDAY);
172 		break;
173 
174 	case FILEGEN_MONTH:
175 		ntpcal_ntp_to_date(&cal, stamp, pivot);
176 		snprintf(suffix, suflen, "%c%04d%02d",
177 			 SUFFIX_SEP, cal.year, cal.month);
178 		cal.hour = cal.minute = cal.second = 0;
179 		cal.monthday = 1;
180 		gen->id_lo = ntpcal_date_to_ntp(&cal);
181 		cal.month++;
182 		gen->id_hi = ntpcal_date_to_ntp(&cal);
183 		break;
184 
185 	case FILEGEN_YEAR:
186 		ntpcal_ntp_to_date(&cal, stamp, pivot);
187 		snprintf(suffix, suflen, "%c%04d",
188 			 SUFFIX_SEP, cal.year);
189 		cal.hour = cal.minute = cal.second = 0;
190 		cal.month = cal.monthday = 1;
191 		gen->id_lo = ntpcal_date_to_ntp(&cal);
192 		cal.year++;
193 		gen->id_hi = ntpcal_date_to_ntp(&cal);
194 		break;
195 
196 	case FILEGEN_AGE:
197 		gen->id_lo = current_time - (current_time % SECSPERDAY);
198 		gen->id_hi = gen->id_lo + SECSPERDAY;
199 		snprintf(suffix, suflen, "%ca%08ld",
200 			 SUFFIX_SEP, gen->id_lo);
201 	}
202 
203 	/* check possible truncation */
204 	if ('\0' != fullname[len - 1]) {
205 		fullname[len - 1] = '\0';
206 		msyslog(LOG_ERR, "logfile name truncated: \"%s\"",
207 			fullname);
208 	}
209 
210 	if (FILEGEN_NONE != gen->type) {
211 		/*
212 		 * check for existence of a file with name 'basename'
213 		 * as we disallow such a file
214 		 * if FGEN_FLAG_LINK is set create a link
215 		 */
216 		struct stat stats;
217 		/*
218 		 * try to resolve name collisions
219 		 */
220 		static u_long conflicts = 0;
221 
222 #ifndef	S_ISREG
223 #define	S_ISREG(mode)	(((mode) & S_IFREG) == S_IFREG)
224 #endif
225 		if (stat(filename, &stats) == 0) {
226 			/* Hm, file exists... */
227 			if (S_ISREG(stats.st_mode)) {
228 				if (stats.st_nlink <= 1)	{
229 					/*
230 					 * Oh, it is not linked - try to save it
231 					 */
232 					savename = emalloc(len);
233 					snprintf(savename, len,
234 						"%s%c%dC%lu",
235 						filename, SUFFIX_SEP,
236 						(int)getpid(), conflicts++);
237 
238 					if (rename(filename, savename) != 0)
239 						msyslog(LOG_ERR,
240 							"couldn't save %s: %m",
241 							filename);
242 					free(savename);
243 				} else {
244 					/*
245 					 * there is at least a second link to
246 					 * this file.
247 					 * just remove the conflicting one
248 					 */
249 					if (
250 #if !defined(VMS)
251 						unlink(filename) != 0
252 #else
253 						delete(filename) != 0
254 #endif
255 						)
256 						msyslog(LOG_ERR,
257 							"couldn't unlink %s: %m",
258 							filename);
259 				}
260 			} else {
261 				/*
262 				 * Ehh? Not a regular file ?? strange !!!!
263 				 */
264 				msyslog(LOG_ERR,
265 					"expected regular file for %s "
266 					"(found mode 0%lo)",
267 					filename,
268 					(unsigned long)stats.st_mode);
269 			}
270 		} else {
271 			/*
272 			 * stat(..) failed, but it is absolutely correct for
273 			 * 'basename' not to exist
274 			 */
275 			if (ENOENT != errno)
276 				msyslog(LOG_ERR, "stat(%s) failed: %m",
277 						 filename);
278 		}
279 	}
280 
281 	/*
282 	 * now, try to open new file generation...
283 	 */
284 	DPRINTF(4, ("opening filegen (type=%d/stamp=%u) \"%s\"\n",
285 		    gen->type, stamp, fullname));
286 
287 	fp = fopen(fullname, "a");
288 
289 	if (NULL == fp)	{
290 		/* open failed -- keep previous state
291 		 *
292 		 * If the file was open before keep the previous generation.
293 		 * This will cause output to end up in the 'wrong' file,
294 		 * but I think this is still better than losing output
295 		 *
296 		 * ignore errors due to missing directories
297 		 */
298 
299 		if (ENOENT != errno)
300 			msyslog(LOG_ERR, "can't open %s: %m", fullname);
301 	} else {
302 		if (NULL != gen->fp) {
303 			fclose(gen->fp);
304 			gen->fp = NULL;
305 		}
306 		gen->fp = fp;
307 
308 		if (gen->flag & FGEN_FLAG_LINK) {
309 			/*
310 			 * need to link file to basename
311 			 * have to use hardlink for now as I want to allow
312 			 * gen->basename spanning directory levels
313 			 * this would make it more complex to get the correct
314 			 * fullname for symlink
315 			 *
316 			 * Ok, it would just mean taking the part following
317 			 * the last '/' in the name.... Should add it later....
318 			 */
319 
320 			/* Windows NT does not support file links -Greg Schueman 1/18/97 */
321 
322 #if defined(SYS_WINNT) || defined(SYS_VXWORKS)
323 			SetLastError(0); /* On WinNT, don't support FGEN_FLAG_LINK */
324 #elif defined(VMS)
325 			errno = 0; /* On VMS, don't support FGEN_FLAG_LINK */
326 #else  /* not (VMS) / VXWORKS / WINNT ; DO THE LINK) */
327 			if (link(fullname, filename) != 0)
328 				if (EEXIST != errno)
329 					msyslog(LOG_ERR,
330 						"can't link(%s, %s): %m",
331 						fullname, filename);
332 #endif /* SYS_WINNT || VXWORKS */
333 		}		/* flags & FGEN_FLAG_LINK */
334 	}			/* else fp == NULL */
335 
336 	free(filename);
337 	free(fullname);
338 	return;
339 }
340 
341 /*
342  * this function sets up gen->fp to point to the correct
343  * generation of the file for the time specified by 'now'
344  *
345  * 'now' usually is interpreted as second part of a l_fp as is in the cal...
346  * library routines
347  */
348 
349 void
filegen_setup(FILEGEN * gen,u_int32 now)350 filegen_setup(
351 	FILEGEN *	gen,
352 	u_int32		now
353 	)
354 {
355 	int	current;
356 	time_t	pivot;
357 
358 	if (!(gen->flag & FGEN_FLAG_ENABLED)) {
359 		if (NULL != gen->fp) {
360 			fclose(gen->fp);
361 			gen->fp = NULL;
362 		}
363 		return;
364 	}
365 
366 	switch (gen->type) {
367 
368 	default:
369 	case FILEGEN_NONE:
370 		current = TRUE;
371 		break;
372 
373 	case FILEGEN_PID:
374 		current = ((int)gen->id_lo == getpid());
375 		break;
376 
377 	case FILEGEN_AGE:
378 		current = (gen->id_lo <= current_time) &&
379 			  (gen->id_hi > current_time);
380 		break;
381 
382 	case FILEGEN_DAY:
383 	case FILEGEN_WEEK:
384 	case FILEGEN_MONTH:
385 	case FILEGEN_YEAR:
386 		current = (gen->id_lo <= now) &&
387 			  (gen->id_hi > now);
388 		break;
389 	}
390 	/*
391 	 * try to open file if not yet open
392 	 * reopen new file generation file on change of generation id
393 	 */
394 	if (NULL == gen->fp || !current) {
395 		DPRINTF(1, ("filegen  %0x %u\n", gen->type, now));
396 		pivot = time(NULL);
397 		filegen_open(gen, now, &pivot);
398 	}
399 }
400 
401 
402 /*
403  * change settings for filegen files
404  */
405 void
filegen_config(FILEGEN * gen,const char * dir,const char * fname,u_int type,u_int flag)406 filegen_config(
407 	FILEGEN *	gen,
408 	const char *	dir,
409 	const char *	fname,
410 	u_int		type,
411 	u_int		flag
412 	)
413 {
414 	int file_existed;
415 	l_fp now;
416 
417 
418 	/*
419 	 * if nothing would be changed...
420 	 */
421 	if (strcmp(dir, gen->dir) == 0 && strcmp(fname, gen->fname) == 0
422 	    && type == gen->type && flag == gen->flag)
423 		return;
424 
425 	/*
426 	 * validate parameters
427 	 */
428 	if (!valid_fileref(dir, fname))
429 		return;
430 
431 	if (NULL != gen->fp) {
432 		fclose(gen->fp);
433 		gen->fp = NULL;
434 		file_existed = TRUE;
435 	} else {
436 		file_existed = FALSE;
437 	}
438 
439 	DPRINTF(3, ("configuring filegen:\n"
440 		    "\tdir:\t%s -> %s\n"
441 		    "\tfname:\t%s -> %s\n"
442 		    "\ttype:\t%d -> %d\n"
443 		    "\tflag: %x -> %x\n",
444 		    gen->dir, dir,
445 		    gen->fname, fname,
446 		    gen->type, type,
447 		    gen->flag, flag));
448 
449 	if (strcmp(gen->dir, dir) != 0) {
450 		free(gen->dir);
451 		gen->dir = estrdup(dir);
452 	}
453 
454 	if (strcmp(gen->fname, fname) != 0) {
455 		free(gen->fname);
456 		gen->fname = estrdup(fname);
457 	}
458 	gen->type = (u_char)type;
459 	gen->flag = (u_char)flag;
460 
461 	/*
462 	 * make filegen use the new settings
463 	 * special action is only required when a generation file
464 	 * is currently open
465 	 * otherwise the new settings will be used anyway at the next open
466 	 */
467 	if (file_existed) {
468 		get_systime(&now);
469 		filegen_setup(gen, now.l_ui);
470 	}
471 }
472 
473 
474 /*
475  * check whether concatenating prefix and basename
476  * yields a legal filename
477  */
478 static int
valid_fileref(const char * dir,const char * fname)479 valid_fileref(
480 	const char *	dir,
481 	const char *	fname
482 	)
483 {
484 	/*
485 	 * dir cannot be changed dynamically
486 	 * (within the context of filegen)
487 	 * so just reject basenames containing '..'
488 	 *
489 	 * ASSUMPTION:
490 	 *		file system parts 'below' dir may be
491 	 *		specified without infringement of security
492 	 *
493 	 *		restricting dir to legal values
494 	 *		has to be ensured by other means
495 	 * (however, it would be possible to perform some checks here...)
496 	 */
497 	const char *p;
498 
499 	/*
500 	 * Just to catch, dumb errors opening up the world...
501 	 */
502 	if (NULL == dir || '\0' == dir[0])
503 		return FALSE;
504 
505 	if (NULL == fname)
506 		return FALSE;
507 
508 #ifdef SYS_WINNT
509 	/*
510 	 * Windows treats / equivalent to \, reject any / to ensure
511 	 * check below for DIR_SEP (\ on windows) are adequate.
512 	 */
513 	if (strchr(fname, '/')) {
514 		msyslog(LOG_ERR,
515 			"filegen filenames must not contain '/': %s",
516 			fname);
517 		return FALSE;
518 	}
519 #endif
520 
521 	for (p = fname; p != NULL; p = strchr(p, DIR_SEP)) {
522 		if ('.' == p[0] && '.' == p[1]
523 		    && ('\0' == p[2] || DIR_SEP == p[2]))
524 			return FALSE;
525 	}
526 
527 	return TRUE;
528 }
529 
530 
531 /*
532  * filegen registry
533  */
534 
535 static struct filegen_entry {
536 	char *			name;
537 	FILEGEN *		filegen;
538 	struct filegen_entry *	next;
539 } *filegen_registry = NULL;
540 
541 
542 FILEGEN *
filegen_get(const char * name)543 filegen_get(
544 	const char *	name
545 	)
546 {
547 	struct filegen_entry *f = filegen_registry;
548 
549 	while (f) {
550 		if (f->name == name || strcmp(name, f->name) == 0) {
551 			DPRINTF(4, ("filegen_get(%s) = %p\n",
552 				    name, f->filegen));
553 			return f->filegen;
554 		}
555 		f = f->next;
556 	}
557 	DPRINTF(4, ("filegen_get(%s) = NULL\n", name));
558 	return NULL;
559 }
560 
561 
562 void
filegen_register(const char * dir,const char * name,FILEGEN * filegen)563 filegen_register(
564 	const char *	dir,
565 	const char *	name,
566 	FILEGEN *	filegen
567 	)
568 {
569 	struct filegen_entry **ppfe;
570 
571 	DPRINTF(4, ("filegen_register(%s, %p)\n", name, filegen));
572 
573 	filegen_init(dir, name, filegen);
574 
575 	ppfe = &filegen_registry;
576 	while (NULL != *ppfe) {
577 		if ((*ppfe)->name == name
578 		    || !strcmp((*ppfe)->name, name)) {
579 
580 			DPRINTF(5, ("replacing filegen %p\n",
581 				    (*ppfe)->filegen));
582 
583 			(*ppfe)->filegen = filegen;
584 			return;
585 		}
586 		ppfe = &((*ppfe)->next);
587 	}
588 
589 	*ppfe = emalloc(sizeof **ppfe);
590 
591 	(*ppfe)->next = NULL;
592 	(*ppfe)->name = estrdup(name);
593 	(*ppfe)->filegen = filegen;
594 
595 	DPRINTF(6, ("adding new filegen\n"));
596 
597 	return;
598 }
599 
600 
601 /*
602  * filegen_statsdir() - reset each filegen entry's dir to statsdir.
603  */
604 void
filegen_statsdir(void)605 filegen_statsdir(void)
606 {
607 	struct filegen_entry *f;
608 
609 	for (f = filegen_registry; f != NULL; f = f->next)
610 		filegen_config(f->filegen, statsdir, f->filegen->fname,
611 			       f->filegen->type, f->filegen->flag);
612 }
613 
614 
615 /*
616  * filegen_unregister frees memory allocated by filegen_register for
617  * name.
618  */
619 #ifdef DEBUG
620 void
filegen_unregister(const char * name)621 filegen_unregister(
622 	const char *name
623 	)
624 {
625 	struct filegen_entry **	ppfe;
626 	struct filegen_entry *	pfe;
627 	FILEGEN *		fg;
628 
629 	DPRINTF(4, ("filegen_unregister(%s)\n", name));
630 
631 	ppfe = &filegen_registry;
632 
633 	while (NULL != *ppfe) {
634 		if ((*ppfe)->name == name
635 		    || !strcmp((*ppfe)->name, name)) {
636 			pfe = *ppfe;
637 			*ppfe = (*ppfe)->next;
638 			fg = pfe->filegen;
639 			free(pfe->name);
640 			free(pfe);
641 			filegen_uninit(fg);
642 			break;
643 		}
644 		ppfe = &((*ppfe)->next);
645 	}
646 }
647 #endif	/* DEBUG */
648