1 /*
2  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
3  *
4  * SPDX-License-Identifier: MPL-2.0
5  *
6  * This Source Code Form is subject to the terms of the Mozilla Public
7  * License, v. 2.0. If a copy of the MPL was not distributed with this
8  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
9  *
10  * See the COPYRIGHT file distributed with this work for additional
11  * information regarding copyright ownership.
12  */
13 
14 /*! \file */
15 
16 #include <errno.h>
17 #include <inttypes.h>
18 #include <limits.h>
19 #include <stdbool.h>
20 #include <stdlib.h>
21 #include <sys/types.h> /* dev_t FreeBSD 2.1 */
22 #include <time.h>
23 
24 #include <isc/atomic.h>
25 #include <isc/dir.h>
26 #include <isc/file.h>
27 #include <isc/log.h>
28 #include <isc/magic.h>
29 #include <isc/mem.h>
30 #include <isc/platform.h>
31 #include <isc/print.h>
32 #include <isc/rwlock.h>
33 #include <isc/stat.h>
34 #include <isc/stdio.h>
35 #include <isc/string.h>
36 #include <isc/time.h>
37 #include <isc/util.h>
38 
39 #define LCTX_MAGIC	    ISC_MAGIC('L', 'c', 't', 'x')
40 #define VALID_CONTEXT(lctx) ISC_MAGIC_VALID(lctx, LCTX_MAGIC)
41 
42 #define LCFG_MAGIC	   ISC_MAGIC('L', 'c', 'f', 'g')
43 #define VALID_CONFIG(lcfg) ISC_MAGIC_VALID(lcfg, LCFG_MAGIC)
44 
45 #define RDLOCK(lp)   RWLOCK(lp, isc_rwlocktype_read);
46 #define WRLOCK(lp)   RWLOCK(lp, isc_rwlocktype_write);
47 #define RDUNLOCK(lp) RWUNLOCK(lp, isc_rwlocktype_read);
48 #define WRUNLOCK(lp) RWUNLOCK(lp, isc_rwlocktype_write);
49 
50 /*
51  * XXXDCL make dynamic?
52  */
53 #define LOG_BUFFER_SIZE (8 * 1024)
54 
55 /*!
56  * This is the structure that holds each named channel.  A simple linked
57  * list chains all of the channels together, so an individual channel is
58  * found by doing strcmp()s with the names down the list.  Their should
59  * be no performance penalty from this as it is expected that the number
60  * of named channels will be no more than a dozen or so, and name lookups
61  * from the head of the list are only done when isc_log_usechannel() is
62  * called, which should also be very infrequent.
63  */
64 typedef struct isc_logchannel isc_logchannel_t;
65 
66 struct isc_logchannel {
67 	char *name;
68 	unsigned int type;
69 	int level;
70 	unsigned int flags;
71 	isc_logdestination_t destination;
72 	ISC_LINK(isc_logchannel_t) link;
73 };
74 
75 /*!
76  * The logchannellist structure associates categories and modules with
77  * channels.  First the appropriate channellist is found based on the
78  * category, and then each structure in the linked list is checked for
79  * a matching module.  It is expected that the number of channels
80  * associated with any given category will be very short, no more than
81  * three or four in the more unusual cases.
82  */
83 typedef struct isc_logchannellist isc_logchannellist_t;
84 
85 struct isc_logchannellist {
86 	const isc_logmodule_t *module;
87 	isc_logchannel_t *channel;
88 	ISC_LINK(isc_logchannellist_t) link;
89 };
90 
91 /*!
92  * This structure is used to remember messages for pruning via
93  * isc_log_[v]write1().
94  */
95 typedef struct isc_logmessage isc_logmessage_t;
96 
97 struct isc_logmessage {
98 	char *text;
99 	isc_time_t time;
100 	ISC_LINK(isc_logmessage_t) link;
101 };
102 
103 /*!
104  * The isc_logconfig structure is used to store the configurable information
105  * about where messages are actually supposed to be sent -- the information
106  * that could changed based on some configuration file, as opposed to the
107  * the category/module specification of isc_log_[v]write[1] that is compiled
108  * into a program, or the debug_level which is dynamic state information.
109  */
110 struct isc_logconfig {
111 	unsigned int magic;
112 	isc_log_t *lctx;
113 	ISC_LIST(isc_logchannel_t) channels;
114 	ISC_LIST(isc_logchannellist_t) * channellists;
115 	unsigned int channellist_count;
116 	unsigned int duplicate_interval;
117 	int_fast32_t highest_level;
118 	char *tag;
119 	bool dynamic;
120 };
121 
122 /*!
123  * This isc_log structure provides the context for the isc_log functions.
124  * The log context locks itself in isc_log_doit, the internal backend to
125  * isc_log_write.  The locking is necessary both to provide exclusive access
126  * to the buffer into which the message is formatted and to guard against
127  * competing threads trying to write to the same syslog resource.  (On
128  * some systems, such as BSD/OS, stdio is thread safe but syslog is not.)
129  * Unfortunately, the lock cannot guard against a _different_ logging
130  * context in the same program competing for syslog's attention.  Thus
131  * There Can Be Only One, but this is not enforced.
132  * XXXDCL enforce it?
133  *
134  * Note that the category and module information is not locked.
135  * This is because in the usual case, only one isc_log_t is ever created
136  * in a program, and the category/module registration happens only once.
137  * XXXDCL it might be wise to add more locking overall.
138  */
139 struct isc_log {
140 	/* Not locked. */
141 	unsigned int magic;
142 	isc_mem_t *mctx;
143 	isc_logcategory_t *categories;
144 	unsigned int category_count;
145 	isc_logmodule_t *modules;
146 	unsigned int module_count;
147 	atomic_int_fast32_t debug_level;
148 	isc_rwlock_t lcfg_rwl;
149 	/* Locked by isc_log lcfg_rwl */
150 	isc_logconfig_t *logconfig;
151 	isc_mutex_t lock;
152 	/* Locked by isc_log lock. */
153 	char buffer[LOG_BUFFER_SIZE];
154 	ISC_LIST(isc_logmessage_t) messages;
155 	atomic_bool dynamic;
156 	atomic_int_fast32_t highest_level;
157 };
158 
159 /*!
160  * Used when ISC_LOG_PRINTLEVEL is enabled for a channel.
161  */
162 static const char *log_level_strings[] = { "debug",   "info",  "notice",
163 					   "warning", "error", "critical" };
164 
165 /*!
166  * Used to convert ISC_LOG_* priorities into syslog priorities.
167  * XXXDCL This will need modification for NT.
168  */
169 static const int syslog_map[] = { LOG_DEBUG,   LOG_INFO, LOG_NOTICE,
170 				  LOG_WARNING, LOG_ERR,	 LOG_CRIT };
171 
172 /*!
173  * When adding new categories, a corresponding ISC_LOGCATEGORY_foo
174  * definition needs to be added to <isc/log.h>.
175  *
176  * The default category is provided so that the internal default can
177  * be overridden.  Since the default is always looked up as the first
178  * channellist in the log context, it must come first in isc_categories[].
179  */
180 LIBISC_EXTERNAL_DATA isc_logcategory_t isc_categories[] = { { "default",
181 							      0 }, /* "default
182 								      must come
183 								      first. */
184 							    { "general", 0 },
185 							    { NULL, 0 } };
186 
187 /*!
188  * See above comment for categories on LIBISC_EXTERNAL_DATA, and apply it to
189  * modules.
190  */
191 LIBISC_EXTERNAL_DATA isc_logmodule_t isc_modules[] = {
192 	{ "socket", 0 }, { "time", 0 },	  { "interface", 0 }, { "timer", 0 },
193 	{ "file", 0 },	 { "netmgr", 0 }, { "other", 0 },     { NULL, 0 }
194 };
195 
196 /*!
197  * This essentially constant structure must be filled in at run time,
198  * because its channel member is pointed to a channel that is created
199  * dynamically with isc_log_createchannel.
200  */
201 static isc_logchannellist_t default_channel;
202 
203 /*!
204  * libisc logs to this context.
205  */
206 LIBISC_EXTERNAL_DATA isc_log_t *isc_lctx = NULL;
207 
208 /*!
209  * Forward declarations.
210  */
211 static void
212 assignchannel(isc_logconfig_t *lcfg, unsigned int category_id,
213 	      const isc_logmodule_t *module, isc_logchannel_t *channel);
214 
215 static void
216 sync_channellist(isc_logconfig_t *lcfg);
217 
218 static void
219 sync_highest_level(isc_log_t *lctx, isc_logconfig_t *lcfg);
220 
221 static isc_result_t
222 greatest_version(isc_logfile_t *file, int versions, int *greatest);
223 
224 static void
225 isc_log_doit(isc_log_t *lctx, isc_logcategory_t *category,
226 	     isc_logmodule_t *module, int level, bool write_once,
227 	     const char *format, va_list args) ISC_FORMAT_PRINTF(6, 0);
228 
229 /*@{*/
230 /*!
231  * Convenience macros.
232  */
233 
234 #define FACILITY(channel)	 (channel->destination.facility)
235 #define FILE_NAME(channel)	 (channel->destination.file.name)
236 #define FILE_STREAM(channel)	 (channel->destination.file.stream)
237 #define FILE_VERSIONS(channel)	 (channel->destination.file.versions)
238 #define FILE_SUFFIX(channel)	 (channel->destination.file.suffix)
239 #define FILE_MAXSIZE(channel)	 (channel->destination.file.maximum_size)
240 #define FILE_MAXREACHED(channel) (channel->destination.file.maximum_reached)
241 
242 /*@}*/
243 /****
244 **** Public interfaces.
245 ****/
246 
247 /*
248  * Establish a new logging context, with default channels.
249  */
250 void
isc_log_create(isc_mem_t * mctx,isc_log_t ** lctxp,isc_logconfig_t ** lcfgp)251 isc_log_create(isc_mem_t *mctx, isc_log_t **lctxp, isc_logconfig_t **lcfgp) {
252 	isc_log_t *lctx;
253 	isc_logconfig_t *lcfg = NULL;
254 
255 	REQUIRE(mctx != NULL);
256 	REQUIRE(lctxp != NULL && *lctxp == NULL);
257 	REQUIRE(lcfgp == NULL || *lcfgp == NULL);
258 
259 	lctx = isc_mem_get(mctx, sizeof(*lctx));
260 	lctx->mctx = NULL;
261 	isc_mem_attach(mctx, &lctx->mctx);
262 	lctx->categories = NULL;
263 	lctx->category_count = 0;
264 	lctx->modules = NULL;
265 	lctx->module_count = 0;
266 	atomic_init(&lctx->debug_level, 0);
267 
268 	ISC_LIST_INIT(lctx->messages);
269 
270 	isc_mutex_init(&lctx->lock);
271 	isc_rwlock_init(&lctx->lcfg_rwl, 0, 0);
272 
273 	/*
274 	 * Normally setting the magic number is the last step done
275 	 * in a creation function, but a valid log context is needed
276 	 * by isc_log_registercategories and isc_logconfig_create.
277 	 * If either fails, the lctx is destroyed and not returned
278 	 * to the caller.
279 	 */
280 	lctx->magic = LCTX_MAGIC;
281 
282 	isc_log_registercategories(lctx, isc_categories);
283 	isc_log_registermodules(lctx, isc_modules);
284 	isc_logconfig_create(lctx, &lcfg);
285 
286 	sync_channellist(lcfg);
287 
288 	lctx->logconfig = lcfg;
289 
290 	atomic_init(&lctx->highest_level, lcfg->highest_level);
291 	atomic_init(&lctx->dynamic, lcfg->dynamic);
292 
293 	*lctxp = lctx;
294 	if (lcfgp != NULL) {
295 		*lcfgp = lcfg;
296 	}
297 }
298 
299 void
isc_logconfig_create(isc_log_t * lctx,isc_logconfig_t ** lcfgp)300 isc_logconfig_create(isc_log_t *lctx, isc_logconfig_t **lcfgp) {
301 	isc_logconfig_t *lcfg;
302 	isc_logdestination_t destination;
303 	int level = ISC_LOG_INFO;
304 
305 	REQUIRE(lcfgp != NULL && *lcfgp == NULL);
306 	REQUIRE(VALID_CONTEXT(lctx));
307 
308 	lcfg = isc_mem_get(lctx->mctx, sizeof(*lcfg));
309 
310 	lcfg->lctx = lctx;
311 	lcfg->channellists = NULL;
312 	lcfg->channellist_count = 0;
313 	lcfg->duplicate_interval = 0;
314 	lcfg->highest_level = level;
315 	lcfg->tag = NULL;
316 	lcfg->dynamic = false;
317 	ISC_LIST_INIT(lcfg->channels);
318 	lcfg->magic = LCFG_MAGIC;
319 
320 	/*
321 	 * Create the default channels:
322 	 *      default_syslog, default_stderr, default_debug and null.
323 	 */
324 	destination.facility = LOG_DAEMON;
325 	isc_log_createchannel(lcfg, "default_syslog", ISC_LOG_TOSYSLOG, level,
326 			      &destination, 0);
327 
328 	destination.file.stream = stderr;
329 	destination.file.name = NULL;
330 	destination.file.versions = ISC_LOG_ROLLNEVER;
331 	destination.file.suffix = isc_log_rollsuffix_increment;
332 	destination.file.maximum_size = 0;
333 	isc_log_createchannel(lcfg, "default_stderr", ISC_LOG_TOFILEDESC, level,
334 			      &destination, ISC_LOG_PRINTTIME);
335 
336 	/*
337 	 * Set the default category's channel to default_stderr,
338 	 * which is at the head of the channels list because it was
339 	 * just created.
340 	 */
341 	default_channel.channel = ISC_LIST_HEAD(lcfg->channels);
342 
343 	destination.file.stream = stderr;
344 	destination.file.name = NULL;
345 	destination.file.versions = ISC_LOG_ROLLNEVER;
346 	destination.file.suffix = isc_log_rollsuffix_increment;
347 	destination.file.maximum_size = 0;
348 	isc_log_createchannel(lcfg, "default_debug", ISC_LOG_TOFILEDESC,
349 			      ISC_LOG_DYNAMIC, &destination, ISC_LOG_PRINTTIME);
350 
351 	isc_log_createchannel(lcfg, "null", ISC_LOG_TONULL, ISC_LOG_DYNAMIC,
352 			      NULL, 0);
353 
354 	*lcfgp = lcfg;
355 }
356 
357 void
isc_logconfig_use(isc_log_t * lctx,isc_logconfig_t * lcfg)358 isc_logconfig_use(isc_log_t *lctx, isc_logconfig_t *lcfg) {
359 	isc_logconfig_t *old_cfg;
360 
361 	REQUIRE(VALID_CONTEXT(lctx));
362 	REQUIRE(VALID_CONFIG(lcfg));
363 	REQUIRE(lcfg->lctx == lctx);
364 
365 	/*
366 	 * Ensure that lcfg->channellist_count == lctx->category_count.
367 	 * They won't be equal if isc_log_usechannel has not been called
368 	 * since any call to isc_log_registercategories.
369 	 */
370 	sync_channellist(lcfg);
371 
372 	WRLOCK(&lctx->lcfg_rwl);
373 	old_cfg = lctx->logconfig;
374 	lctx->logconfig = lcfg;
375 	sync_highest_level(lctx, lcfg);
376 	WRUNLOCK(&lctx->lcfg_rwl);
377 
378 	isc_logconfig_destroy(&old_cfg);
379 }
380 
381 void
isc_log_destroy(isc_log_t ** lctxp)382 isc_log_destroy(isc_log_t **lctxp) {
383 	isc_log_t *lctx;
384 	isc_logconfig_t *lcfg;
385 	isc_mem_t *mctx;
386 	isc_logmessage_t *message;
387 
388 	REQUIRE(lctxp != NULL && VALID_CONTEXT(*lctxp));
389 
390 	lctx = *lctxp;
391 	*lctxp = NULL;
392 	mctx = lctx->mctx;
393 
394 	/* Stop the logging as a first thing */
395 	atomic_store_release(&lctx->debug_level, 0);
396 	atomic_store_release(&lctx->highest_level, 0);
397 	atomic_store_release(&lctx->dynamic, false);
398 
399 	WRLOCK(&lctx->lcfg_rwl);
400 	lcfg = lctx->logconfig;
401 	lctx->logconfig = NULL;
402 	WRUNLOCK(&lctx->lcfg_rwl);
403 
404 	if (lcfg != NULL) {
405 		isc_logconfig_destroy(&lcfg);
406 	}
407 
408 	isc_rwlock_destroy(&lctx->lcfg_rwl);
409 	isc_mutex_destroy(&lctx->lock);
410 
411 	while ((message = ISC_LIST_HEAD(lctx->messages)) != NULL) {
412 		ISC_LIST_UNLINK(lctx->messages, message, link);
413 
414 		isc_mem_put(mctx, message,
415 			    sizeof(*message) + strlen(message->text) + 1);
416 	}
417 
418 	lctx->buffer[0] = '\0';
419 	lctx->categories = NULL;
420 	lctx->category_count = 0;
421 	lctx->modules = NULL;
422 	lctx->module_count = 0;
423 	lctx->mctx = NULL;
424 	lctx->magic = 0;
425 
426 	isc_mem_putanddetach(&mctx, lctx, sizeof(*lctx));
427 }
428 
429 void
isc_logconfig_destroy(isc_logconfig_t ** lcfgp)430 isc_logconfig_destroy(isc_logconfig_t **lcfgp) {
431 	isc_logconfig_t *lcfg;
432 	isc_mem_t *mctx;
433 	isc_logchannel_t *channel;
434 	char *filename;
435 	unsigned int i;
436 
437 	REQUIRE(lcfgp != NULL && VALID_CONFIG(*lcfgp));
438 
439 	lcfg = *lcfgp;
440 	*lcfgp = NULL;
441 
442 	/*
443 	 * This function cannot be called with a logconfig that is in
444 	 * use by a log context.
445 	 */
446 	REQUIRE(lcfg->lctx != NULL);
447 
448 	RDLOCK(&lcfg->lctx->lcfg_rwl);
449 	REQUIRE(lcfg->lctx->logconfig != lcfg);
450 	RDUNLOCK(&lcfg->lctx->lcfg_rwl);
451 
452 	mctx = lcfg->lctx->mctx;
453 
454 	while ((channel = ISC_LIST_HEAD(lcfg->channels)) != NULL) {
455 		ISC_LIST_UNLINK(lcfg->channels, channel, link);
456 
457 		if (channel->type == ISC_LOG_TOFILE) {
458 			/*
459 			 * The filename for the channel may have ultimately
460 			 * started its life in user-land as a const string,
461 			 * but in isc_log_createchannel it gets copied
462 			 * into writable memory and is not longer truly const.
463 			 */
464 			DE_CONST(FILE_NAME(channel), filename);
465 			isc_mem_free(mctx, filename);
466 
467 			if (FILE_STREAM(channel) != NULL) {
468 				(void)fclose(FILE_STREAM(channel));
469 			}
470 		}
471 
472 		isc_mem_free(mctx, channel->name);
473 		isc_mem_put(mctx, channel, sizeof(*channel));
474 	}
475 
476 	for (i = 0; i < lcfg->channellist_count; i++) {
477 		isc_logchannellist_t *item;
478 		while ((item = ISC_LIST_HEAD(lcfg->channellists[i])) != NULL) {
479 			ISC_LIST_UNLINK(lcfg->channellists[i], item, link);
480 			isc_mem_put(mctx, item, sizeof(*item));
481 		}
482 	}
483 
484 	if (lcfg->channellist_count > 0) {
485 		isc_mem_put(mctx, lcfg->channellists,
486 			    lcfg->channellist_count *
487 				    sizeof(ISC_LIST(isc_logchannellist_t)));
488 	}
489 
490 	lcfg->dynamic = false;
491 	if (lcfg->tag != NULL) {
492 		isc_mem_free(lcfg->lctx->mctx, lcfg->tag);
493 	}
494 	lcfg->tag = NULL;
495 	lcfg->highest_level = 0;
496 	lcfg->duplicate_interval = 0;
497 	lcfg->magic = 0;
498 
499 	isc_mem_put(mctx, lcfg, sizeof(*lcfg));
500 }
501 
502 void
isc_log_registercategories(isc_log_t * lctx,isc_logcategory_t categories[])503 isc_log_registercategories(isc_log_t *lctx, isc_logcategory_t categories[]) {
504 	isc_logcategory_t *catp;
505 
506 	REQUIRE(VALID_CONTEXT(lctx));
507 	REQUIRE(categories != NULL && categories[0].name != NULL);
508 
509 	/*
510 	 * XXXDCL This somewhat sleazy situation of using the last pointer
511 	 * in one category array to point to the next array exists because
512 	 * this registration function returns void and I didn't want to have
513 	 * change everything that used it by making it return an isc_result_t.
514 	 * It would need to do that if it had to allocate memory to store
515 	 * pointers to each array passed in.
516 	 */
517 	if (lctx->categories == NULL) {
518 		lctx->categories = categories;
519 	} else {
520 		/*
521 		 * Adjust the last (NULL) pointer of the already registered
522 		 * categories to point to the incoming array.
523 		 */
524 		for (catp = lctx->categories; catp->name != NULL;) {
525 			if (catp->id == UINT_MAX) {
526 				/*
527 				 * The name pointer points to the next array.
528 				 * Ick.
529 				 */
530 				DE_CONST(catp->name, catp);
531 			} else {
532 				catp++;
533 			}
534 		}
535 
536 		catp->name = (void *)categories;
537 		catp->id = UINT_MAX;
538 	}
539 
540 	/*
541 	 * Update the id number of the category with its new global id.
542 	 */
543 	for (catp = categories; catp->name != NULL; catp++) {
544 		catp->id = lctx->category_count++;
545 	}
546 }
547 
548 isc_logcategory_t *
isc_log_categorybyname(isc_log_t * lctx,const char * name)549 isc_log_categorybyname(isc_log_t *lctx, const char *name) {
550 	isc_logcategory_t *catp;
551 
552 	REQUIRE(VALID_CONTEXT(lctx));
553 	REQUIRE(name != NULL);
554 
555 	for (catp = lctx->categories; catp->name != NULL;) {
556 		if (catp->id == UINT_MAX) {
557 			/*
558 			 * catp is neither modified nor returned to the
559 			 * caller, so removing its const qualifier is ok.
560 			 */
561 			DE_CONST(catp->name, catp);
562 		} else {
563 			if (strcmp(catp->name, name) == 0) {
564 				return (catp);
565 			}
566 			catp++;
567 		}
568 	}
569 
570 	return (NULL);
571 }
572 
573 void
isc_log_registermodules(isc_log_t * lctx,isc_logmodule_t modules[])574 isc_log_registermodules(isc_log_t *lctx, isc_logmodule_t modules[]) {
575 	isc_logmodule_t *modp;
576 
577 	REQUIRE(VALID_CONTEXT(lctx));
578 	REQUIRE(modules != NULL && modules[0].name != NULL);
579 
580 	/*
581 	 * XXXDCL This somewhat sleazy situation of using the last pointer
582 	 * in one category array to point to the next array exists because
583 	 * this registration function returns void and I didn't want to have
584 	 * change everything that used it by making it return an isc_result_t.
585 	 * It would need to do that if it had to allocate memory to store
586 	 * pointers to each array passed in.
587 	 */
588 	if (lctx->modules == NULL) {
589 		lctx->modules = modules;
590 	} else {
591 		/*
592 		 * Adjust the last (NULL) pointer of the already registered
593 		 * modules to point to the incoming array.
594 		 */
595 		for (modp = lctx->modules; modp->name != NULL;) {
596 			if (modp->id == UINT_MAX) {
597 				/*
598 				 * The name pointer points to the next array.
599 				 * Ick.
600 				 */
601 				DE_CONST(modp->name, modp);
602 			} else {
603 				modp++;
604 			}
605 		}
606 
607 		modp->name = (void *)modules;
608 		modp->id = UINT_MAX;
609 	}
610 
611 	/*
612 	 * Update the id number of the module with its new global id.
613 	 */
614 	for (modp = modules; modp->name != NULL; modp++) {
615 		modp->id = lctx->module_count++;
616 	}
617 }
618 
619 isc_logmodule_t *
isc_log_modulebyname(isc_log_t * lctx,const char * name)620 isc_log_modulebyname(isc_log_t *lctx, const char *name) {
621 	isc_logmodule_t *modp;
622 
623 	REQUIRE(VALID_CONTEXT(lctx));
624 	REQUIRE(name != NULL);
625 
626 	for (modp = lctx->modules; modp->name != NULL;) {
627 		if (modp->id == UINT_MAX) {
628 			/*
629 			 * modp is neither modified nor returned to the
630 			 * caller, so removing its const qualifier is ok.
631 			 */
632 			DE_CONST(modp->name, modp);
633 		} else {
634 			if (strcmp(modp->name, name) == 0) {
635 				return (modp);
636 			}
637 			modp++;
638 		}
639 	}
640 
641 	return (NULL);
642 }
643 
644 void
isc_log_createchannel(isc_logconfig_t * lcfg,const char * name,unsigned int type,int level,const isc_logdestination_t * destination,unsigned int flags)645 isc_log_createchannel(isc_logconfig_t *lcfg, const char *name,
646 		      unsigned int type, int level,
647 		      const isc_logdestination_t *destination,
648 		      unsigned int flags) {
649 	isc_logchannel_t *channel;
650 	isc_mem_t *mctx;
651 	unsigned int permitted = ISC_LOG_PRINTALL | ISC_LOG_DEBUGONLY |
652 				 ISC_LOG_BUFFERED | ISC_LOG_ISO8601 |
653 				 ISC_LOG_UTC;
654 
655 	REQUIRE(VALID_CONFIG(lcfg));
656 	REQUIRE(name != NULL);
657 	REQUIRE(type == ISC_LOG_TOSYSLOG || type == ISC_LOG_TOFILE ||
658 		type == ISC_LOG_TOFILEDESC || type == ISC_LOG_TONULL);
659 	REQUIRE(destination != NULL || type == ISC_LOG_TONULL);
660 	REQUIRE(level >= ISC_LOG_CRITICAL);
661 	REQUIRE((flags & ~permitted) == 0);
662 
663 	/* XXXDCL find duplicate names? */
664 
665 	mctx = lcfg->lctx->mctx;
666 
667 	channel = isc_mem_get(mctx, sizeof(*channel));
668 
669 	channel->name = isc_mem_strdup(mctx, name);
670 
671 	channel->type = type;
672 	channel->level = level;
673 	channel->flags = flags;
674 	ISC_LINK_INIT(channel, link);
675 
676 	switch (type) {
677 	case ISC_LOG_TOSYSLOG:
678 		FACILITY(channel) = destination->facility;
679 		break;
680 
681 	case ISC_LOG_TOFILE:
682 		/*
683 		 * The file name is copied because greatest_version wants
684 		 * to scribble on it, so it needs to be definitely in
685 		 * writable memory.
686 		 */
687 		FILE_NAME(channel) = isc_mem_strdup(mctx,
688 						    destination->file.name);
689 		FILE_STREAM(channel) = NULL;
690 		FILE_VERSIONS(channel) = destination->file.versions;
691 		FILE_SUFFIX(channel) = destination->file.suffix;
692 		FILE_MAXSIZE(channel) = destination->file.maximum_size;
693 		FILE_MAXREACHED(channel) = false;
694 		break;
695 
696 	case ISC_LOG_TOFILEDESC:
697 		FILE_NAME(channel) = NULL;
698 		FILE_STREAM(channel) = destination->file.stream;
699 		FILE_MAXSIZE(channel) = 0;
700 		FILE_VERSIONS(channel) = ISC_LOG_ROLLNEVER;
701 		FILE_SUFFIX(channel) = isc_log_rollsuffix_increment;
702 		break;
703 
704 	case ISC_LOG_TONULL:
705 		/* Nothing. */
706 		break;
707 
708 	default:
709 		INSIST(0);
710 		ISC_UNREACHABLE();
711 	}
712 
713 	ISC_LIST_PREPEND(lcfg->channels, channel, link);
714 
715 	/*
716 	 * If default_stderr was redefined, make the default category
717 	 * point to the new default_stderr.
718 	 */
719 	if (strcmp(name, "default_stderr") == 0) {
720 		default_channel.channel = channel;
721 	}
722 }
723 
724 isc_result_t
isc_log_usechannel(isc_logconfig_t * lcfg,const char * name,const isc_logcategory_t * category,const isc_logmodule_t * module)725 isc_log_usechannel(isc_logconfig_t *lcfg, const char *name,
726 		   const isc_logcategory_t *category,
727 		   const isc_logmodule_t *module) {
728 	isc_log_t *lctx;
729 	isc_logchannel_t *channel;
730 
731 	REQUIRE(VALID_CONFIG(lcfg));
732 	REQUIRE(name != NULL);
733 
734 	lctx = lcfg->lctx;
735 
736 	REQUIRE(category == NULL || category->id < lctx->category_count);
737 	REQUIRE(module == NULL || module->id < lctx->module_count);
738 
739 	for (channel = ISC_LIST_HEAD(lcfg->channels); channel != NULL;
740 	     channel = ISC_LIST_NEXT(channel, link))
741 	{
742 		if (strcmp(name, channel->name) == 0) {
743 			break;
744 		}
745 	}
746 
747 	if (channel == NULL) {
748 		return (ISC_R_NOTFOUND);
749 	}
750 
751 	if (category != NULL) {
752 		assignchannel(lcfg, category->id, module, channel);
753 	} else {
754 		/*
755 		 * Assign to all categories.  Note that this includes
756 		 * the default channel.
757 		 */
758 		for (size_t i = 0; i < lctx->category_count; i++) {
759 			assignchannel(lcfg, i, module, channel);
760 		}
761 	}
762 
763 	/*
764 	 * Update the highest logging level, if the current lcfg is in use.
765 	 */
766 	if (lcfg->lctx->logconfig == lcfg) {
767 		sync_highest_level(lctx, lcfg);
768 	}
769 
770 	return (ISC_R_SUCCESS);
771 }
772 
773 void
isc_log_write(isc_log_t * lctx,isc_logcategory_t * category,isc_logmodule_t * module,int level,const char * format,...)774 isc_log_write(isc_log_t *lctx, isc_logcategory_t *category,
775 	      isc_logmodule_t *module, int level, const char *format, ...) {
776 	va_list args;
777 
778 	/*
779 	 * Contract checking is done in isc_log_doit().
780 	 */
781 
782 	va_start(args, format);
783 	isc_log_doit(lctx, category, module, level, false, format, args);
784 	va_end(args);
785 }
786 
787 void
isc_log_vwrite(isc_log_t * lctx,isc_logcategory_t * category,isc_logmodule_t * module,int level,const char * format,va_list args)788 isc_log_vwrite(isc_log_t *lctx, isc_logcategory_t *category,
789 	       isc_logmodule_t *module, int level, const char *format,
790 	       va_list args) {
791 	/*
792 	 * Contract checking is done in isc_log_doit().
793 	 */
794 	isc_log_doit(lctx, category, module, level, false, format, args);
795 }
796 
797 void
isc_log_write1(isc_log_t * lctx,isc_logcategory_t * category,isc_logmodule_t * module,int level,const char * format,...)798 isc_log_write1(isc_log_t *lctx, isc_logcategory_t *category,
799 	       isc_logmodule_t *module, int level, const char *format, ...) {
800 	va_list args;
801 
802 	/*
803 	 * Contract checking is done in isc_log_doit().
804 	 */
805 
806 	va_start(args, format);
807 	isc_log_doit(lctx, category, module, level, true, format, args);
808 	va_end(args);
809 }
810 
811 void
isc_log_vwrite1(isc_log_t * lctx,isc_logcategory_t * category,isc_logmodule_t * module,int level,const char * format,va_list args)812 isc_log_vwrite1(isc_log_t *lctx, isc_logcategory_t *category,
813 		isc_logmodule_t *module, int level, const char *format,
814 		va_list args) {
815 	/*
816 	 * Contract checking is done in isc_log_doit().
817 	 */
818 	isc_log_doit(lctx, category, module, level, true, format, args);
819 }
820 
821 void
isc_log_setcontext(isc_log_t * lctx)822 isc_log_setcontext(isc_log_t *lctx) {
823 	isc_lctx = lctx;
824 }
825 
826 void
isc_log_setdebuglevel(isc_log_t * lctx,unsigned int level)827 isc_log_setdebuglevel(isc_log_t *lctx, unsigned int level) {
828 	REQUIRE(VALID_CONTEXT(lctx));
829 
830 	atomic_store_release(&lctx->debug_level, level);
831 	/*
832 	 * Close ISC_LOG_DEBUGONLY channels if level is zero.
833 	 */
834 	if (level == 0) {
835 		RDLOCK(&lctx->lcfg_rwl);
836 		isc_logconfig_t *lcfg = lctx->logconfig;
837 		if (lcfg != NULL) {
838 			LOCK(&lctx->lock);
839 			for (isc_logchannel_t *channel =
840 				     ISC_LIST_HEAD(lcfg->channels);
841 			     channel != NULL;
842 			     channel = ISC_LIST_NEXT(channel, link))
843 			{
844 				if (channel->type == ISC_LOG_TOFILE &&
845 				    (channel->flags & ISC_LOG_DEBUGONLY) != 0 &&
846 				    FILE_STREAM(channel) != NULL)
847 				{
848 					(void)fclose(FILE_STREAM(channel));
849 					FILE_STREAM(channel) = NULL;
850 				}
851 			}
852 			UNLOCK(&lctx->lock);
853 		}
854 		RDUNLOCK(&lctx->lcfg_rwl);
855 	}
856 }
857 
858 unsigned int
isc_log_getdebuglevel(isc_log_t * lctx)859 isc_log_getdebuglevel(isc_log_t *lctx) {
860 	REQUIRE(VALID_CONTEXT(lctx));
861 
862 	return (atomic_load_acquire(&lctx->debug_level));
863 }
864 
865 void
isc_log_setduplicateinterval(isc_logconfig_t * lcfg,unsigned int interval)866 isc_log_setduplicateinterval(isc_logconfig_t *lcfg, unsigned int interval) {
867 	REQUIRE(VALID_CONFIG(lcfg));
868 
869 	lcfg->duplicate_interval = interval;
870 }
871 
872 unsigned int
isc_log_getduplicateinterval(isc_logconfig_t * lcfg)873 isc_log_getduplicateinterval(isc_logconfig_t *lcfg) {
874 	REQUIRE(VALID_CONTEXT(lcfg));
875 
876 	return (lcfg->duplicate_interval);
877 }
878 
879 void
isc_log_settag(isc_logconfig_t * lcfg,const char * tag)880 isc_log_settag(isc_logconfig_t *lcfg, const char *tag) {
881 	REQUIRE(VALID_CONFIG(lcfg));
882 
883 	if (tag != NULL && *tag != '\0') {
884 		if (lcfg->tag != NULL) {
885 			isc_mem_free(lcfg->lctx->mctx, lcfg->tag);
886 		}
887 		lcfg->tag = isc_mem_strdup(lcfg->lctx->mctx, tag);
888 	} else {
889 		if (lcfg->tag != NULL) {
890 			isc_mem_free(lcfg->lctx->mctx, lcfg->tag);
891 		}
892 		lcfg->tag = NULL;
893 	}
894 }
895 
896 char *
isc_log_gettag(isc_logconfig_t * lcfg)897 isc_log_gettag(isc_logconfig_t *lcfg) {
898 	REQUIRE(VALID_CONFIG(lcfg));
899 
900 	return (lcfg->tag);
901 }
902 
903 /* XXXDCL NT  -- This interface will assuredly be changing. */
904 void
isc_log_opensyslog(const char * tag,int options,int facility)905 isc_log_opensyslog(const char *tag, int options, int facility) {
906 	(void)openlog(tag, options, facility);
907 }
908 
909 void
isc_log_closefilelogs(isc_log_t * lctx)910 isc_log_closefilelogs(isc_log_t *lctx) {
911 	REQUIRE(VALID_CONTEXT(lctx));
912 
913 	RDLOCK(&lctx->lcfg_rwl);
914 	isc_logconfig_t *lcfg = lctx->logconfig;
915 	if (lcfg != NULL) {
916 		LOCK(&lctx->lock);
917 		for (isc_logchannel_t *channel = ISC_LIST_HEAD(lcfg->channels);
918 		     channel != NULL; channel = ISC_LIST_NEXT(channel, link))
919 		{
920 			if (channel->type == ISC_LOG_TOFILE &&
921 			    FILE_STREAM(channel) != NULL) {
922 				(void)fclose(FILE_STREAM(channel));
923 				FILE_STREAM(channel) = NULL;
924 			}
925 		}
926 		UNLOCK(&lctx->lock);
927 	}
928 	RDUNLOCK(&lctx->lcfg_rwl);
929 }
930 
931 /****
932 **** Internal functions
933 ****/
934 
935 static void
assignchannel(isc_logconfig_t * lcfg,unsigned int category_id,const isc_logmodule_t * module,isc_logchannel_t * channel)936 assignchannel(isc_logconfig_t *lcfg, unsigned int category_id,
937 	      const isc_logmodule_t *module, isc_logchannel_t *channel) {
938 	isc_logchannellist_t *new_item;
939 	isc_log_t *lctx;
940 
941 	REQUIRE(VALID_CONFIG(lcfg));
942 
943 	lctx = lcfg->lctx;
944 
945 	REQUIRE(category_id < lctx->category_count);
946 	REQUIRE(module == NULL || module->id < lctx->module_count);
947 	REQUIRE(channel != NULL);
948 
949 	/*
950 	 * Ensure lcfg->channellist_count == lctx->category_count.
951 	 */
952 	sync_channellist(lcfg);
953 
954 	new_item = isc_mem_get(lctx->mctx, sizeof(*new_item));
955 
956 	new_item->channel = channel;
957 	new_item->module = module;
958 	ISC_LIST_INITANDPREPEND(lcfg->channellists[category_id], new_item,
959 				link);
960 
961 	/*
962 	 * Remember the highest logging level set by any channel in the
963 	 * logging config, so isc_log_doit() can quickly return if the
964 	 * message is too high to be logged by any channel.
965 	 */
966 	if (channel->type != ISC_LOG_TONULL) {
967 		if (lcfg->highest_level < channel->level) {
968 			lcfg->highest_level = channel->level;
969 		}
970 		if (channel->level == ISC_LOG_DYNAMIC) {
971 			lcfg->dynamic = true;
972 		}
973 	}
974 }
975 
976 /*
977  * This would ideally be part of isc_log_registercategories(), except then
978  * that function would have to return isc_result_t instead of void.
979  */
980 static void
sync_channellist(isc_logconfig_t * lcfg)981 sync_channellist(isc_logconfig_t *lcfg) {
982 	unsigned int bytes;
983 	isc_log_t *lctx;
984 	void *lists;
985 
986 	REQUIRE(VALID_CONFIG(lcfg));
987 
988 	lctx = lcfg->lctx;
989 
990 	REQUIRE(lctx->category_count != 0);
991 
992 	if (lctx->category_count == lcfg->channellist_count) {
993 		return;
994 	}
995 
996 	bytes = lctx->category_count * sizeof(ISC_LIST(isc_logchannellist_t));
997 
998 	lists = isc_mem_get(lctx->mctx, bytes);
999 
1000 	memset(lists, 0, bytes);
1001 
1002 	if (lcfg->channellist_count != 0) {
1003 		bytes = lcfg->channellist_count *
1004 			sizeof(ISC_LIST(isc_logchannellist_t));
1005 		memmove(lists, lcfg->channellists, bytes);
1006 		isc_mem_put(lctx->mctx, lcfg->channellists, bytes);
1007 	}
1008 
1009 	lcfg->channellists = lists;
1010 	lcfg->channellist_count = lctx->category_count;
1011 }
1012 
1013 static void
sync_highest_level(isc_log_t * lctx,isc_logconfig_t * lcfg)1014 sync_highest_level(isc_log_t *lctx, isc_logconfig_t *lcfg) {
1015 	atomic_store(&lctx->highest_level, lcfg->highest_level);
1016 	atomic_store(&lctx->dynamic, lcfg->dynamic);
1017 }
1018 
1019 static isc_result_t
greatest_version(isc_logfile_t * file,int versions,int * greatestp)1020 greatest_version(isc_logfile_t *file, int versions, int *greatestp) {
1021 	char *bname, *digit_end;
1022 	const char *dirname;
1023 	int version, greatest = -1;
1024 	size_t bnamelen;
1025 	isc_dir_t dir;
1026 	isc_result_t result;
1027 	char sep = '/';
1028 #ifdef _WIN32
1029 	char *bname2;
1030 #endif /* ifdef _WIN32 */
1031 
1032 	/*
1033 	 * It is safe to DE_CONST the file.name because it was copied
1034 	 * with isc_mem_strdup().
1035 	 */
1036 	bname = strrchr(file->name, sep);
1037 #ifdef _WIN32
1038 	bname2 = strrchr(file->name, '\\');
1039 	if ((bname != NULL && bname2 != NULL && bname2 > bname) ||
1040 	    (bname == NULL && bname2 != NULL))
1041 	{
1042 		bname = bname2;
1043 		sep = '\\';
1044 	}
1045 #endif /* ifdef _WIN32 */
1046 	if (bname != NULL) {
1047 		*bname++ = '\0';
1048 		dirname = file->name;
1049 	} else {
1050 		DE_CONST(file->name, bname);
1051 		dirname = ".";
1052 	}
1053 	bnamelen = strlen(bname);
1054 
1055 	isc_dir_init(&dir);
1056 	result = isc_dir_open(&dir, dirname);
1057 
1058 	/*
1059 	 * Replace the file separator if it was taken out.
1060 	 */
1061 	if (bname != file->name) {
1062 		*(bname - 1) = sep;
1063 	}
1064 
1065 	/*
1066 	 * Return if the directory open failed.
1067 	 */
1068 	if (result != ISC_R_SUCCESS) {
1069 		return (result);
1070 	}
1071 
1072 	while (isc_dir_read(&dir) == ISC_R_SUCCESS) {
1073 		if (dir.entry.length > bnamelen &&
1074 		    strncmp(dir.entry.name, bname, bnamelen) == 0 &&
1075 		    dir.entry.name[bnamelen] == '.')
1076 		{
1077 			version = strtol(&dir.entry.name[bnamelen + 1],
1078 					 &digit_end, 10);
1079 			/*
1080 			 * Remove any backup files that exceed versions.
1081 			 */
1082 			if (*digit_end == '\0' && version >= versions) {
1083 				result = isc_file_remove(dir.entry.name);
1084 				if (result != ISC_R_SUCCESS &&
1085 				    result != ISC_R_FILENOTFOUND) {
1086 					syslog(LOG_ERR,
1087 					       "unable to remove "
1088 					       "log file '%s': %s",
1089 					       dir.entry.name,
1090 					       isc_result_totext(result));
1091 				}
1092 			} else if (*digit_end == '\0' && version > greatest) {
1093 				greatest = version;
1094 			}
1095 		}
1096 	}
1097 	isc_dir_close(&dir);
1098 
1099 	*greatestp = greatest;
1100 
1101 	return (ISC_R_SUCCESS);
1102 }
1103 
1104 static void
insert_sort(int64_t to_keep[],int64_t versions,int version)1105 insert_sort(int64_t to_keep[], int64_t versions, int version) {
1106 	int i = 0;
1107 	while (i < versions && version < to_keep[i]) {
1108 		i++;
1109 	}
1110 	if (i == versions) {
1111 		return;
1112 	}
1113 	if (i < versions - 1) {
1114 		memmove(&to_keep[i + 1], &to_keep[i],
1115 			sizeof(to_keep[0]) * (versions - i - 1));
1116 	}
1117 	to_keep[i] = version;
1118 }
1119 
1120 static int64_t
last_to_keep(int64_t versions,isc_dir_t * dirp,char * bname,size_t bnamelen)1121 last_to_keep(int64_t versions, isc_dir_t *dirp, char *bname, size_t bnamelen) {
1122 	if (versions <= 0) {
1123 		return INT64_MAX;
1124 	}
1125 
1126 	int64_t to_keep[ISC_LOG_MAX_VERSIONS] = { 0 };
1127 	int64_t version = 0;
1128 	if (versions > ISC_LOG_MAX_VERSIONS) {
1129 		versions = ISC_LOG_MAX_VERSIONS;
1130 	}
1131 	/*
1132 	 * First we fill 'to_keep' structure using insertion sort
1133 	 */
1134 	memset(to_keep, 0, sizeof(to_keep));
1135 	while (isc_dir_read(dirp) == ISC_R_SUCCESS) {
1136 		if (dirp->entry.length <= bnamelen ||
1137 		    strncmp(dirp->entry.name, bname, bnamelen) != 0 ||
1138 		    dirp->entry.name[bnamelen] != '.')
1139 		{
1140 			continue;
1141 		}
1142 
1143 		char *digit_end;
1144 		char *ename = &dirp->entry.name[bnamelen + 1];
1145 		version = strtoull(ename, &digit_end, 10);
1146 		if (*digit_end == '\0') {
1147 			insert_sort(to_keep, versions, version);
1148 		}
1149 	}
1150 
1151 	isc_dir_reset(dirp);
1152 
1153 	/*
1154 	 * to_keep[versions - 1] is the last one we want to keep
1155 	 */
1156 	return (to_keep[versions - 1]);
1157 }
1158 
1159 static isc_result_t
remove_old_tsversions(isc_logfile_t * file,int versions)1160 remove_old_tsversions(isc_logfile_t *file, int versions) {
1161 	isc_result_t result;
1162 	char *bname, *digit_end;
1163 	const char *dirname;
1164 	int64_t version, last = INT64_MAX;
1165 	size_t bnamelen;
1166 	isc_dir_t dir;
1167 	char sep = '/';
1168 #ifdef _WIN32
1169 	char *bname2;
1170 #endif /* ifdef _WIN32 */
1171 	/*
1172 	 * It is safe to DE_CONST the file.name because it was copied
1173 	 * with isc_mem_strdup().
1174 	 */
1175 	bname = strrchr(file->name, sep);
1176 #ifdef _WIN32
1177 	bname2 = strrchr(file->name, '\\');
1178 	if ((bname != NULL && bname2 != NULL && bname2 > bname) ||
1179 	    (bname == NULL && bname2 != NULL))
1180 	{
1181 		bname = bname2;
1182 		sep = '\\';
1183 	}
1184 #endif /* ifdef _WIN32 */
1185 	if (bname != NULL) {
1186 		*bname++ = '\0';
1187 		dirname = file->name;
1188 	} else {
1189 		DE_CONST(file->name, bname);
1190 		dirname = ".";
1191 	}
1192 	bnamelen = strlen(bname);
1193 
1194 	isc_dir_init(&dir);
1195 	result = isc_dir_open(&dir, dirname);
1196 
1197 	/*
1198 	 * Replace the file separator if it was taken out.
1199 	 */
1200 	if (bname != file->name) {
1201 		*(bname - 1) = sep;
1202 	}
1203 
1204 	/*
1205 	 * Return if the directory open failed.
1206 	 */
1207 	if (result != ISC_R_SUCCESS) {
1208 		return (result);
1209 	}
1210 
1211 	last = last_to_keep(versions, &dir, bname, bnamelen);
1212 
1213 	/*
1214 	 * Then we remove all files that we don't want to_keep
1215 	 */
1216 	while (isc_dir_read(&dir) == ISC_R_SUCCESS) {
1217 		if (dir.entry.length > bnamelen &&
1218 		    strncmp(dir.entry.name, bname, bnamelen) == 0 &&
1219 		    dir.entry.name[bnamelen] == '.')
1220 		{
1221 			char *ename = &dir.entry.name[bnamelen + 1];
1222 			version = strtoull(ename, &digit_end, 10);
1223 			/*
1224 			 * Remove any backup files that exceed versions.
1225 			 */
1226 			if (*digit_end == '\0' && version < last) {
1227 				result = isc_file_remove(dir.entry.name);
1228 				if (result != ISC_R_SUCCESS &&
1229 				    result != ISC_R_FILENOTFOUND) {
1230 					syslog(LOG_ERR,
1231 					       "unable to remove "
1232 					       "log file '%s': %s",
1233 					       dir.entry.name,
1234 					       isc_result_totext(result));
1235 				}
1236 			}
1237 		}
1238 	}
1239 
1240 	isc_dir_close(&dir);
1241 
1242 	return (ISC_R_SUCCESS);
1243 }
1244 
1245 static isc_result_t
roll_increment(isc_logfile_t * file)1246 roll_increment(isc_logfile_t *file) {
1247 	int i, n, greatest;
1248 	char current[PATH_MAX + 1];
1249 	char newpath[PATH_MAX + 1];
1250 	const char *path;
1251 	isc_result_t result = ISC_R_SUCCESS;
1252 
1253 	REQUIRE(file != NULL);
1254 	REQUIRE(file->versions != 0);
1255 
1256 	path = file->name;
1257 
1258 	if (file->versions == ISC_LOG_ROLLINFINITE) {
1259 		/*
1260 		 * Find the first missing entry in the log file sequence.
1261 		 */
1262 		for (greatest = 0; greatest < INT_MAX; greatest++) {
1263 			n = snprintf(current, sizeof(current), "%s.%u", path,
1264 				     (unsigned)greatest);
1265 			if (n >= (int)sizeof(current) || n < 0 ||
1266 			    !isc_file_exists(current)) {
1267 				break;
1268 			}
1269 		}
1270 	} else {
1271 		/*
1272 		 * Get the largest existing version and remove any
1273 		 * version greater than the permitted version.
1274 		 */
1275 		result = greatest_version(file, file->versions, &greatest);
1276 		if (result != ISC_R_SUCCESS) {
1277 			return (result);
1278 		}
1279 
1280 		/*
1281 		 * Increment if greatest is not the actual maximum value.
1282 		 */
1283 		if (greatest < file->versions - 1) {
1284 			greatest++;
1285 		}
1286 	}
1287 
1288 	for (i = greatest; i > 0; i--) {
1289 		result = ISC_R_SUCCESS;
1290 		n = snprintf(current, sizeof(current), "%s.%u", path,
1291 			     (unsigned)(i - 1));
1292 		if (n >= (int)sizeof(current) || n < 0) {
1293 			result = ISC_R_NOSPACE;
1294 		}
1295 		if (result == ISC_R_SUCCESS) {
1296 			n = snprintf(newpath, sizeof(newpath), "%s.%u", path,
1297 				     (unsigned)i);
1298 			if (n >= (int)sizeof(newpath) || n < 0) {
1299 				result = ISC_R_NOSPACE;
1300 			}
1301 		}
1302 		if (result == ISC_R_SUCCESS) {
1303 			result = isc_file_rename(current, newpath);
1304 		}
1305 		if (result != ISC_R_SUCCESS && result != ISC_R_FILENOTFOUND) {
1306 			syslog(LOG_ERR,
1307 			       "unable to rename log file '%s.%u' to "
1308 			       "'%s.%u': %s",
1309 			       path, i - 1, path, i, isc_result_totext(result));
1310 		}
1311 	}
1312 
1313 	n = snprintf(newpath, sizeof(newpath), "%s.0", path);
1314 	if (n >= (int)sizeof(newpath) || n < 0) {
1315 		result = ISC_R_NOSPACE;
1316 	} else {
1317 		result = isc_file_rename(path, newpath);
1318 	}
1319 	if (result != ISC_R_SUCCESS && result != ISC_R_FILENOTFOUND) {
1320 		syslog(LOG_ERR, "unable to rename log file '%s' to '%s.0': %s",
1321 		       path, path, isc_result_totext(result));
1322 	}
1323 
1324 	return (ISC_R_SUCCESS);
1325 }
1326 
1327 static isc_result_t
roll_timestamp(isc_logfile_t * file)1328 roll_timestamp(isc_logfile_t *file) {
1329 	int n;
1330 	char newts[PATH_MAX + 1];
1331 	char newpath[PATH_MAX + 1];
1332 	const char *path;
1333 	isc_time_t now;
1334 	isc_result_t result = ISC_R_SUCCESS;
1335 
1336 	REQUIRE(file != NULL);
1337 	REQUIRE(file->versions != 0);
1338 
1339 	path = file->name;
1340 
1341 	/*
1342 	 * First find all the logfiles and remove the oldest ones
1343 	 * Save one fewer than file->versions because we'll be renaming
1344 	 * the existing file to a timestamped version after this.
1345 	 */
1346 	if (file->versions != ISC_LOG_ROLLINFINITE) {
1347 		remove_old_tsversions(file, file->versions - 1);
1348 	}
1349 
1350 	/* Then just rename the current logfile */
1351 	isc_time_now(&now);
1352 	isc_time_formatshorttimestamp(&now, newts, PATH_MAX + 1);
1353 	n = snprintf(newpath, sizeof(newpath), "%s.%s", path, newts);
1354 	if (n >= (int)sizeof(newpath) || n < 0) {
1355 		result = ISC_R_NOSPACE;
1356 	} else {
1357 		result = isc_file_rename(path, newpath);
1358 	}
1359 	if (result != ISC_R_SUCCESS && result != ISC_R_FILENOTFOUND) {
1360 		syslog(LOG_ERR, "unable to rename log file '%s' to '%s.0': %s",
1361 		       path, path, isc_result_totext(result));
1362 	}
1363 
1364 	return (ISC_R_SUCCESS);
1365 }
1366 
1367 isc_result_t
isc_logfile_roll(isc_logfile_t * file)1368 isc_logfile_roll(isc_logfile_t *file) {
1369 	isc_result_t result;
1370 
1371 	REQUIRE(file != NULL);
1372 
1373 	/*
1374 	 * Do nothing (not even excess version trimming) if ISC_LOG_ROLLNEVER
1375 	 * is specified.  Apparently complete external control over the log
1376 	 * files is desired.
1377 	 */
1378 	if (file->versions == ISC_LOG_ROLLNEVER) {
1379 		return (ISC_R_SUCCESS);
1380 	} else if (file->versions == 0) {
1381 		result = isc_file_remove(file->name);
1382 		if (result != ISC_R_SUCCESS && result != ISC_R_FILENOTFOUND) {
1383 			syslog(LOG_ERR, "unable to remove log file '%s': %s",
1384 			       file->name, isc_result_totext(result));
1385 		}
1386 		return (ISC_R_SUCCESS);
1387 	}
1388 
1389 	switch (file->suffix) {
1390 	case isc_log_rollsuffix_increment:
1391 		return (roll_increment(file));
1392 	case isc_log_rollsuffix_timestamp:
1393 		return (roll_timestamp(file));
1394 	default:
1395 		return (ISC_R_UNEXPECTED);
1396 	}
1397 }
1398 
1399 static isc_result_t
isc_log_open(isc_logchannel_t * channel)1400 isc_log_open(isc_logchannel_t *channel) {
1401 	struct stat statbuf;
1402 	bool regular_file;
1403 	bool roll = false;
1404 	isc_result_t result = ISC_R_SUCCESS;
1405 	const char *path;
1406 
1407 	REQUIRE(channel->type == ISC_LOG_TOFILE);
1408 	REQUIRE(FILE_STREAM(channel) == NULL);
1409 
1410 	path = FILE_NAME(channel);
1411 
1412 	REQUIRE(path != NULL && *path != '\0');
1413 
1414 	/*
1415 	 * Determine type of file; only regular files will be
1416 	 * version renamed, and only if the base file exists
1417 	 * and either has no size limit or has reached its size limit.
1418 	 */
1419 	if (stat(path, &statbuf) == 0) {
1420 		regular_file = S_ISREG(statbuf.st_mode) ? true : false;
1421 		/* XXXDCL if not regular_file complain? */
1422 		if ((FILE_MAXSIZE(channel) == 0 &&
1423 		     FILE_VERSIONS(channel) != ISC_LOG_ROLLNEVER) ||
1424 		    (FILE_MAXSIZE(channel) > 0 &&
1425 		     statbuf.st_size >= FILE_MAXSIZE(channel)))
1426 		{
1427 			roll = regular_file;
1428 		}
1429 	} else if (errno == ENOENT) {
1430 		regular_file = true;
1431 		POST(regular_file);
1432 	} else {
1433 		result = ISC_R_INVALIDFILE;
1434 	}
1435 
1436 	/*
1437 	 * Version control.
1438 	 */
1439 	if (result == ISC_R_SUCCESS && roll) {
1440 		if (FILE_VERSIONS(channel) == ISC_LOG_ROLLNEVER) {
1441 			return (ISC_R_MAXSIZE);
1442 		}
1443 		result = isc_logfile_roll(&channel->destination.file);
1444 		if (result != ISC_R_SUCCESS) {
1445 			if ((channel->flags & ISC_LOG_OPENERR) == 0) {
1446 				syslog(LOG_ERR,
1447 				       "isc_log_open: isc_logfile_roll '%s' "
1448 				       "failed: %s",
1449 				       FILE_NAME(channel),
1450 				       isc_result_totext(result));
1451 				channel->flags |= ISC_LOG_OPENERR;
1452 			}
1453 			return (result);
1454 		}
1455 	}
1456 
1457 	result = isc_stdio_open(path, "a", &FILE_STREAM(channel));
1458 
1459 	return (result);
1460 }
1461 
1462 ISC_NO_SANITIZE_THREAD bool
isc_log_wouldlog(isc_log_t * lctx,int level)1463 isc_log_wouldlog(isc_log_t *lctx, int level) {
1464 	/*
1465 	 * Try to avoid locking the mutex for messages which can't
1466 	 * possibly be logged to any channels -- primarily debugging
1467 	 * messages that the debug level is not high enough to print.
1468 	 *
1469 	 * If the level is (mathematically) less than or equal to the
1470 	 * highest_level, or if there is a dynamic channel and the level is
1471 	 * less than or equal to the debug level, the main loop must be
1472 	 * entered to see if the message should really be output.
1473 	 */
1474 	if (lctx == NULL) {
1475 		return (false);
1476 	}
1477 
1478 	int highest_level = atomic_load_acquire(&lctx->highest_level);
1479 	if (level <= highest_level) {
1480 		return (true);
1481 	}
1482 	if (atomic_load_acquire(&lctx->dynamic)) {
1483 		int debug_level = atomic_load_acquire(&lctx->debug_level);
1484 		if (level <= debug_level) {
1485 			return (true);
1486 		}
1487 	}
1488 
1489 	return (false);
1490 }
1491 
1492 static void
isc_log_doit(isc_log_t * lctx,isc_logcategory_t * category,isc_logmodule_t * module,int level,bool write_once,const char * format,va_list args)1493 isc_log_doit(isc_log_t *lctx, isc_logcategory_t *category,
1494 	     isc_logmodule_t *module, int level, bool write_once,
1495 	     const char *format, va_list args) {
1496 	int syslog_level;
1497 	const char *time_string;
1498 	char local_time[64];
1499 	char iso8601z_string[64];
1500 	char iso8601l_string[64];
1501 	char level_string[24] = { 0 };
1502 	struct stat statbuf;
1503 	bool matched = false;
1504 	bool printtime, iso8601, utc, printtag, printcolon;
1505 	bool printcategory, printmodule, printlevel, buffered;
1506 	isc_logchannel_t *channel;
1507 	isc_logchannellist_t *category_channels;
1508 	isc_result_t result;
1509 
1510 	REQUIRE(lctx == NULL || VALID_CONTEXT(lctx));
1511 	REQUIRE(category != NULL);
1512 	REQUIRE(module != NULL);
1513 	REQUIRE(level != ISC_LOG_DYNAMIC);
1514 	REQUIRE(format != NULL);
1515 
1516 	/*
1517 	 * Programs can use libraries that use this logging code without
1518 	 * wanting to do any logging, thus the log context is allowed to
1519 	 * be non-existent.
1520 	 */
1521 	if (lctx == NULL) {
1522 		return;
1523 	}
1524 
1525 	REQUIRE(category->id < lctx->category_count);
1526 	REQUIRE(module->id < lctx->module_count);
1527 
1528 	if (!isc_log_wouldlog(lctx, level)) {
1529 		return;
1530 	}
1531 
1532 	local_time[0] = '\0';
1533 	iso8601l_string[0] = '\0';
1534 	iso8601z_string[0] = '\0';
1535 
1536 	RDLOCK(&lctx->lcfg_rwl);
1537 	LOCK(&lctx->lock);
1538 
1539 	lctx->buffer[0] = '\0';
1540 
1541 	isc_logconfig_t *lcfg = lctx->logconfig;
1542 
1543 	category_channels = ISC_LIST_HEAD(lcfg->channellists[category->id]);
1544 
1545 	/*
1546 	 * XXXDCL add duplicate filtering? (To not write multiple times
1547 	 * to the same source via various channels).
1548 	 */
1549 	do {
1550 		/*
1551 		 * If the channel list end was reached and a match was
1552 		 * made, everything is finished.
1553 		 */
1554 		if (category_channels == NULL && matched) {
1555 			break;
1556 		}
1557 
1558 		if (category_channels == NULL && !matched &&
1559 		    category_channels != ISC_LIST_HEAD(lcfg->channellists[0]))
1560 		{
1561 			/*
1562 			 * No category/module pair was explicitly
1563 			 * configured. Try the category named "default".
1564 			 */
1565 			category_channels =
1566 				ISC_LIST_HEAD(lcfg->channellists[0]);
1567 		}
1568 
1569 		if (category_channels == NULL && !matched) {
1570 			/*
1571 			 * No matching module was explicitly configured
1572 			 * for the category named "default".  Use the
1573 			 * internal default channel.
1574 			 */
1575 			category_channels = &default_channel;
1576 		}
1577 
1578 		if (category_channels->module != NULL &&
1579 		    category_channels->module != module) {
1580 			category_channels = ISC_LIST_NEXT(category_channels,
1581 							  link);
1582 			continue;
1583 		}
1584 
1585 		matched = true;
1586 
1587 		channel = category_channels->channel;
1588 		category_channels = ISC_LIST_NEXT(category_channels, link);
1589 
1590 		int_fast32_t dlevel = atomic_load_acquire(&lctx->debug_level);
1591 		if (((channel->flags & ISC_LOG_DEBUGONLY) != 0) && dlevel == 0)
1592 		{
1593 			continue;
1594 		}
1595 
1596 		if (channel->level == ISC_LOG_DYNAMIC) {
1597 			if (dlevel < level) {
1598 				continue;
1599 			}
1600 		} else if (channel->level < level) {
1601 			continue;
1602 		}
1603 
1604 		if ((channel->flags & ISC_LOG_PRINTTIME) != 0 &&
1605 		    local_time[0] == '\0') {
1606 			isc_time_t isctime;
1607 
1608 			TIME_NOW(&isctime);
1609 
1610 			isc_time_formattimestamp(&isctime, local_time,
1611 						 sizeof(local_time));
1612 			isc_time_formatISO8601ms(&isctime, iso8601z_string,
1613 						 sizeof(iso8601z_string));
1614 			isc_time_formatISO8601Lms(&isctime, iso8601l_string,
1615 						  sizeof(iso8601l_string));
1616 		}
1617 
1618 		if ((channel->flags & ISC_LOG_PRINTLEVEL) != 0 &&
1619 		    level_string[0] == '\0') {
1620 			if (level < ISC_LOG_CRITICAL) {
1621 				snprintf(level_string, sizeof(level_string),
1622 					 "level %d: ", level);
1623 			} else if (level > ISC_LOG_DYNAMIC) {
1624 				snprintf(level_string, sizeof(level_string),
1625 					 "%s %d: ", log_level_strings[0],
1626 					 level);
1627 			} else {
1628 				snprintf(level_string, sizeof(level_string),
1629 					 "%s: ", log_level_strings[-level]);
1630 			}
1631 		}
1632 
1633 		/*
1634 		 * Only format the message once.
1635 		 */
1636 		if (lctx->buffer[0] == '\0') {
1637 			(void)vsnprintf(lctx->buffer, sizeof(lctx->buffer),
1638 					format, args);
1639 
1640 			/*
1641 			 * Check for duplicates.
1642 			 */
1643 			if (write_once) {
1644 				isc_logmessage_t *message, *next;
1645 				isc_time_t oldest;
1646 				isc_interval_t interval;
1647 				size_t size;
1648 
1649 				isc_interval_set(&interval,
1650 						 lcfg->duplicate_interval, 0);
1651 
1652 				/*
1653 				 * 'oldest' is the age of the oldest
1654 				 * messages which fall within the
1655 				 * duplicate_interval range.
1656 				 */
1657 				TIME_NOW(&oldest);
1658 				if (isc_time_subtract(&oldest, &interval,
1659 						      &oldest) != ISC_R_SUCCESS)
1660 				{
1661 					/*
1662 					 * Can't effectively do the
1663 					 * checking without having a
1664 					 * valid time.
1665 					 */
1666 					message = NULL;
1667 				} else {
1668 					message = ISC_LIST_HEAD(lctx->messages);
1669 				}
1670 
1671 				while (message != NULL) {
1672 					if (isc_time_compare(&message->time,
1673 							     &oldest) < 0) {
1674 						/*
1675 						 * This message is older
1676 						 * than the
1677 						 * duplicate_interval,
1678 						 * so it should be
1679 						 * dropped from the
1680 						 * history.
1681 						 *
1682 						 * Setting the interval
1683 						 * to be to be longer
1684 						 * will obviously not
1685 						 * cause the expired
1686 						 * message to spring
1687 						 * back into existence.
1688 						 */
1689 						next = ISC_LIST_NEXT(message,
1690 								     link);
1691 
1692 						ISC_LIST_UNLINK(lctx->messages,
1693 								message, link);
1694 
1695 						isc_mem_put(
1696 							lctx->mctx, message,
1697 							sizeof(*message) + 1 +
1698 								strlen(message->text));
1699 
1700 						message = next;
1701 						continue;
1702 					}
1703 
1704 					/*
1705 					 * This message is in the
1706 					 * duplicate filtering interval
1707 					 * ...
1708 					 */
1709 					if (strcmp(lctx->buffer,
1710 						   message->text) == 0) {
1711 						/*
1712 						 * ... and it is a
1713 						 * duplicate. Unlock the
1714 						 * mutex and get the
1715 						 * hell out of Dodge.
1716 						 */
1717 						goto unlock;
1718 					}
1719 
1720 					message = ISC_LIST_NEXT(message, link);
1721 				}
1722 
1723 				/*
1724 				 * It wasn't in the duplicate interval,
1725 				 * so add it to the message list.
1726 				 */
1727 				size = sizeof(isc_logmessage_t) +
1728 				       strlen(lctx->buffer) + 1;
1729 				message = isc_mem_get(lctx->mctx, size);
1730 				message->text = (char *)(message + 1);
1731 				size -= sizeof(isc_logmessage_t);
1732 				strlcpy(message->text, lctx->buffer, size);
1733 				TIME_NOW(&message->time);
1734 				ISC_LINK_INIT(message, link);
1735 				ISC_LIST_APPEND(lctx->messages, message, link);
1736 			}
1737 		}
1738 
1739 		utc = ((channel->flags & ISC_LOG_UTC) != 0);
1740 		iso8601 = ((channel->flags & ISC_LOG_ISO8601) != 0);
1741 		printtime = ((channel->flags & ISC_LOG_PRINTTIME) != 0);
1742 		printtag = ((channel->flags &
1743 			     (ISC_LOG_PRINTTAG | ISC_LOG_PRINTPREFIX)) != 0 &&
1744 			    lcfg->tag != NULL);
1745 		printcolon = ((channel->flags & ISC_LOG_PRINTTAG) != 0 &&
1746 			      lcfg->tag != NULL);
1747 		printcategory = ((channel->flags & ISC_LOG_PRINTCATEGORY) != 0);
1748 		printmodule = ((channel->flags & ISC_LOG_PRINTMODULE) != 0);
1749 		printlevel = ((channel->flags & ISC_LOG_PRINTLEVEL) != 0);
1750 		buffered = ((channel->flags & ISC_LOG_BUFFERED) != 0);
1751 
1752 		if (printtime) {
1753 			if (iso8601) {
1754 				if (utc) {
1755 					time_string = iso8601z_string;
1756 				} else {
1757 					time_string = iso8601l_string;
1758 				}
1759 			} else {
1760 				time_string = local_time;
1761 			}
1762 		} else {
1763 			time_string = "";
1764 		}
1765 
1766 		switch (channel->type) {
1767 		case ISC_LOG_TOFILE:
1768 			if (FILE_MAXREACHED(channel)) {
1769 				/*
1770 				 * If the file can be rolled, OR
1771 				 * If the file no longer exists, OR
1772 				 * If the file is less than the maximum
1773 				 * size, (such as if it had been renamed
1774 				 * and a new one touched, or it was
1775 				 * truncated in place)
1776 				 * ... then close it to trigger
1777 				 * reopening.
1778 				 */
1779 				if (FILE_VERSIONS(channel) !=
1780 					    ISC_LOG_ROLLNEVER ||
1781 				    (stat(FILE_NAME(channel), &statbuf) != 0 &&
1782 				     errno == ENOENT) ||
1783 				    statbuf.st_size < FILE_MAXSIZE(channel))
1784 				{
1785 					(void)fclose(FILE_STREAM(channel));
1786 					FILE_STREAM(channel) = NULL;
1787 					FILE_MAXREACHED(channel) = false;
1788 				} else {
1789 					/*
1790 					 * Eh, skip it.
1791 					 */
1792 					break;
1793 				}
1794 			}
1795 
1796 			if (FILE_STREAM(channel) == NULL) {
1797 				result = isc_log_open(channel);
1798 				if (result != ISC_R_SUCCESS &&
1799 				    result != ISC_R_MAXSIZE &&
1800 				    (channel->flags & ISC_LOG_OPENERR) == 0)
1801 				{
1802 					syslog(LOG_ERR,
1803 					       "isc_log_open '%s' "
1804 					       "failed: %s",
1805 					       FILE_NAME(channel),
1806 					       isc_result_totext(result));
1807 					channel->flags |= ISC_LOG_OPENERR;
1808 				}
1809 				if (result != ISC_R_SUCCESS) {
1810 					break;
1811 				}
1812 				channel->flags &= ~ISC_LOG_OPENERR;
1813 			}
1814 			/* FALLTHROUGH */
1815 
1816 		case ISC_LOG_TOFILEDESC:
1817 			fprintf(FILE_STREAM(channel), "%s%s%s%s%s%s%s%s%s%s\n",
1818 				printtime ? time_string : "",
1819 				printtime ? " " : "", printtag ? lcfg->tag : "",
1820 				printcolon ? ": " : "",
1821 				printcategory ? category->name : "",
1822 				printcategory ? ": " : "",
1823 				printmodule ? (module != NULL ? module->name
1824 							      : "no_module")
1825 					    : "",
1826 				printmodule ? ": " : "",
1827 				printlevel ? level_string : "", lctx->buffer);
1828 
1829 			if (!buffered) {
1830 				fflush(FILE_STREAM(channel));
1831 			}
1832 
1833 			/*
1834 			 * If the file now exceeds its maximum size
1835 			 * threshold, note it so that it will not be
1836 			 * logged to any more.
1837 			 */
1838 			if (FILE_MAXSIZE(channel) > 0) {
1839 				INSIST(channel->type == ISC_LOG_TOFILE);
1840 
1841 				/* XXXDCL NT fstat/fileno */
1842 				/* XXXDCL complain if fstat fails? */
1843 				if (fstat(fileno(FILE_STREAM(channel)),
1844 					  &statbuf) >= 0 &&
1845 				    statbuf.st_size > FILE_MAXSIZE(channel))
1846 				{
1847 					FILE_MAXREACHED(channel) = true;
1848 				}
1849 			}
1850 
1851 			break;
1852 
1853 		case ISC_LOG_TOSYSLOG:
1854 			if (level > 0) {
1855 				syslog_level = LOG_DEBUG;
1856 			} else if (level < ISC_LOG_CRITICAL) {
1857 				syslog_level = LOG_CRIT;
1858 			} else {
1859 				syslog_level = syslog_map[-level];
1860 			}
1861 
1862 			(void)syslog(
1863 				FACILITY(channel) | syslog_level,
1864 				"%s%s%s%s%s%s%s%s%s%s",
1865 				printtime ? time_string : "",
1866 				printtime ? " " : "", printtag ? lcfg->tag : "",
1867 				printcolon ? ": " : "",
1868 				printcategory ? category->name : "",
1869 				printcategory ? ": " : "",
1870 				printmodule ? (module != NULL ? module->name
1871 							      : "no_module")
1872 					    : "",
1873 				printmodule ? ": " : "",
1874 				printlevel ? level_string : "", lctx->buffer);
1875 			break;
1876 
1877 		case ISC_LOG_TONULL:
1878 			break;
1879 		}
1880 	} while (1);
1881 
1882 unlock:
1883 	UNLOCK(&lctx->lock);
1884 	RDUNLOCK(&lctx->lcfg_rwl);
1885 }
1886