xref: /netbsd-src/external/bsd/openldap/dist/libraries/libldap/util-int.c (revision 6cf6fe02a981b55727c49c3d37b0d8191a98c0ee)
1 /*	$NetBSD: util-int.c,v 1.1.1.4 2014/05/28 09:58:42 tron Exp $	*/
2 
3 /* $OpenLDAP$ */
4 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
5  *
6  * Copyright 1998-2014 The OpenLDAP Foundation.
7  * Portions Copyright 1998 A. Hartgers.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted only as authorized by the OpenLDAP
12  * Public License.
13  *
14  * A copy of this license is available in the file LICENSE in the
15  * top-level directory of the distribution or, alternatively, at
16  * <http://www.OpenLDAP.org/license.html>.
17  */
18 /* ACKNOWLEDGEMENTS:
19  * This work was initially developed by Bart Hartgers for inclusion in
20  * OpenLDAP Software.
21  */
22 
23 /*
24  * util-int.c	Various functions to replace missing threadsafe ones.
25  *				Without the real *_r funcs, things will
26  *				work, but might not be threadsafe.
27  */
28 
29 #include "portable.h"
30 
31 #include <ac/stdlib.h>
32 
33 #include <ac/errno.h>
34 #include <ac/socket.h>
35 #include <ac/string.h>
36 #include <ac/time.h>
37 #include <ac/unistd.h>
38 
39 #include "ldap-int.h"
40 
41 #ifndef h_errno
42 /* newer systems declare this in <netdb.h> for you, older ones don't.
43  * harmless to declare it again (unless defined by a macro).
44  */
45 extern int h_errno;
46 #endif
47 
48 #ifdef HAVE_HSTRERROR
49 # define HSTRERROR(e)	hstrerror(e)
50 #else
51 # define HSTRERROR(e)	hp_strerror(e)
52 #endif
53 
54 #ifndef LDAP_R_COMPILE
55 # undef HAVE_REENTRANT_FUNCTIONS
56 # undef HAVE_CTIME_R
57 # undef HAVE_GETHOSTBYNAME_R
58 # undef HAVE_GETHOSTBYADDR_R
59 
60 #else
61 # include <ldap_pvt_thread.h>
62   ldap_pvt_thread_mutex_t ldap_int_resolv_mutex;
63   ldap_pvt_thread_mutex_t ldap_int_hostname_mutex;
64   static ldap_pvt_thread_mutex_t ldap_int_gettime_mutex;
65 
66 # if (defined( HAVE_CTIME_R ) || defined( HAVE_REENTRANT_FUNCTIONS)) \
67 	 && defined( CTIME_R_NARGS )
68 #   define USE_CTIME_R
69 # else
70 	static ldap_pvt_thread_mutex_t ldap_int_ctime_mutex;
71 # endif
72 
73 /* USE_GMTIME_R and USE_LOCALTIME_R defined in ldap_pvt.h */
74 
75 #ifdef LDAP_DEVEL
76 	/* to be released with 2.5 */
77 #if !defined( USE_GMTIME_R ) || !defined( USE_LOCALTIME_R )
78 	/* we use the same mutex for gmtime(3) and localtime(3)
79 	 * because implementations may use the same buffer
80 	 * for both functions */
81 	static ldap_pvt_thread_mutex_t ldap_int_gmtime_mutex;
82 #endif
83 #else /* ! LDAP_DEVEL */
84 	ldap_pvt_thread_mutex_t ldap_int_gmtime_mutex;
85 #endif /* ! LDAP_DEVEL */
86 
87 # if defined(HAVE_GETHOSTBYNAME_R) && \
88 	(GETHOSTBYNAME_R_NARGS < 5) || (6 < GETHOSTBYNAME_R_NARGS)
89 	/* Don't know how to handle this version, pretend it's not there */
90 #	undef HAVE_GETHOSTBYNAME_R
91 # endif
92 # if defined(HAVE_GETHOSTBYADDR_R) && \
93 	(GETHOSTBYADDR_R_NARGS < 7) || (8 < GETHOSTBYADDR_R_NARGS)
94 	/* Don't know how to handle this version, pretend it's not there */
95 #	undef HAVE_GETHOSTBYADDR_R
96 # endif
97 #endif /* LDAP_R_COMPILE */
98 
99 char *ldap_pvt_ctime( const time_t *tp, char *buf )
100 {
101 #ifdef USE_CTIME_R
102 # if (CTIME_R_NARGS > 3) || (CTIME_R_NARGS < 2)
103 #	error "CTIME_R_NARGS should be 2 or 3"
104 # elif CTIME_R_NARGS > 2 && defined(CTIME_R_RETURNS_INT)
105 	return( ctime_r(tp,buf,26) < 0 ? 0 : buf );
106 # elif CTIME_R_NARGS > 2
107 	return ctime_r(tp,buf,26);
108 # else
109 	return ctime_r(tp,buf);
110 # endif
111 
112 #else
113 
114 	LDAP_MUTEX_LOCK( &ldap_int_ctime_mutex );
115 	AC_MEMCPY( buf, ctime(tp), 26 );
116 	LDAP_MUTEX_UNLOCK( &ldap_int_ctime_mutex );
117 
118 	return buf;
119 #endif
120 }
121 
122 #if !defined( USE_GMTIME_R ) || !defined( USE_LOCALTIME_R )
123 int
124 ldap_pvt_gmtime_lock( void )
125 {
126 # ifndef LDAP_R_COMPILE
127 	return 0;
128 # else /* LDAP_R_COMPILE */
129 	return ldap_pvt_thread_mutex_lock( &ldap_int_gmtime_mutex );
130 # endif /* LDAP_R_COMPILE */
131 }
132 
133 int
134 ldap_pvt_gmtime_unlock( void )
135 {
136 # ifndef LDAP_R_COMPILE
137 	return 0;
138 # else /* LDAP_R_COMPILE */
139 	return ldap_pvt_thread_mutex_unlock( &ldap_int_gmtime_mutex );
140 # endif /* LDAP_R_COMPILE */
141 }
142 #endif /* !USE_GMTIME_R || !USE_LOCALTIME_R */
143 
144 #ifndef USE_GMTIME_R
145 struct tm *
146 ldap_pvt_gmtime( const time_t *timep, struct tm *result )
147 {
148 	struct tm *tm_ptr;
149 
150 	LDAP_MUTEX_LOCK( &ldap_int_gmtime_mutex );
151 	tm_ptr = gmtime( timep );
152 	if ( tm_ptr == NULL ) {
153 		result = NULL;
154 
155 	} else {
156 		*result = *tm_ptr;
157 	}
158 	LDAP_MUTEX_UNLOCK( &ldap_int_gmtime_mutex );
159 
160 	return result;
161 }
162 #endif /* !USE_GMTIME_R */
163 
164 #ifndef USE_LOCALTIME_R
165 struct tm *
166 ldap_pvt_localtime( const time_t *timep, struct tm *result )
167 {
168 	struct tm *tm_ptr;
169 
170 	LDAP_MUTEX_LOCK( &ldap_int_gmtime_mutex );
171 	tm_ptr = localtime( timep );
172 	if ( tm_ptr == NULL ) {
173 		result = NULL;
174 
175 	} else {
176 		*result = *tm_ptr;
177 	}
178 	LDAP_MUTEX_UNLOCK( &ldap_int_gmtime_mutex );
179 
180 	return result;
181 }
182 #endif /* !USE_LOCALTIME_R */
183 
184 /* return a broken out time, with microseconds
185  */
186 #ifdef _WIN32
187 /* Windows SYSTEMTIME only has 10 millisecond resolution, so we
188  * also need to use a high resolution timer to get microseconds.
189  * This is pretty clunky.
190  */
191 void
192 ldap_pvt_gettime( struct lutil_tm *tm )
193 {
194 	static LARGE_INTEGER cFreq;
195 	static LARGE_INTEGER prevCount;
196 	static int subs;
197 	static int offset;
198 	LARGE_INTEGER count;
199 	SYSTEMTIME st;
200 
201 	GetSystemTime( &st );
202 	QueryPerformanceCounter( &count );
203 
204 	/* It shouldn't ever go backwards, but multiple CPUs might
205 	 * be able to hit in the same tick.
206 	 */
207 	LDAP_MUTEX_LOCK( &ldap_int_gettime_mutex );
208 	if ( count.QuadPart <= prevCount.QuadPart ) {
209 		subs++;
210 	} else {
211 		subs = 0;
212 		prevCount = count;
213 	}
214 	LDAP_MUTEX_UNLOCK( &ldap_int_gettime_mutex );
215 
216 	/* We assume Windows has at least a vague idea of
217 	 * when a second begins. So we align our microsecond count
218 	 * with the Windows millisecond count using this offset.
219 	 * We retain the submillisecond portion of our own count.
220 	 *
221 	 * Note - this also assumes that the relationship between
222 	 * the PerformanceCouunter and SystemTime stays constant;
223 	 * that assumption breaks if the SystemTime is adjusted by
224 	 * an external action.
225 	 */
226 	if ( !cFreq.QuadPart ) {
227 		long long t;
228 		int usec;
229 		QueryPerformanceFrequency( &cFreq );
230 
231 		/* just get sub-second portion of counter */
232 		t = count.QuadPart % cFreq.QuadPart;
233 
234 		/* convert to microseconds */
235 		t *= 1000000;
236 		usec = t / cFreq.QuadPart;
237 
238 		offset = usec - st.wMilliseconds * 1000;
239 	}
240 
241 	tm->tm_usub = subs;
242 
243 	/* convert to microseconds */
244 	count.QuadPart %= cFreq.QuadPart;
245 	count.QuadPart *= 1000000;
246 	count.QuadPart /= cFreq.QuadPart;
247 	count.QuadPart -= offset;
248 
249 	tm->tm_usec = count.QuadPart % 1000000;
250 	if ( tm->tm_usec < 0 )
251 		tm->tm_usec += 1000000;
252 
253 	/* any difference larger than microseconds is
254 	 * already reflected in st
255 	 */
256 
257 	tm->tm_sec = st.wSecond;
258 	tm->tm_min = st.wMinute;
259 	tm->tm_hour = st.wHour;
260 	tm->tm_mday = st.wDay;
261 	tm->tm_mon = st.wMonth - 1;
262 	tm->tm_year = st.wYear - 1900;
263 }
264 #else
265 void
266 ldap_pvt_gettime( struct lutil_tm *ltm )
267 {
268 	struct timeval tv;
269 	static struct timeval prevTv;
270 	static int subs;
271 
272 	struct tm tm;
273 	time_t t;
274 
275 	gettimeofday( &tv, NULL );
276 	t = tv.tv_sec;
277 
278 	LDAP_MUTEX_LOCK( &ldap_int_gettime_mutex );
279 	if ( tv.tv_sec < prevTv.tv_sec
280 		|| ( tv.tv_sec == prevTv.tv_sec && tv.tv_usec <= prevTv.tv_usec )) {
281 		subs++;
282 	} else {
283 		subs = 0;
284 		prevTv = tv;
285 	}
286 	LDAP_MUTEX_UNLOCK( &ldap_int_gettime_mutex );
287 
288 	ltm->tm_usub = subs;
289 
290 	ldap_pvt_gmtime( &t, &tm );
291 
292 	ltm->tm_sec = tm.tm_sec;
293 	ltm->tm_min = tm.tm_min;
294 	ltm->tm_hour = tm.tm_hour;
295 	ltm->tm_mday = tm.tm_mday;
296 	ltm->tm_mon = tm.tm_mon;
297 	ltm->tm_year = tm.tm_year;
298 	ltm->tm_usec = tv.tv_usec;
299 }
300 #endif
301 
302 size_t
303 ldap_pvt_csnstr(char *buf, size_t len, unsigned int replica, unsigned int mod)
304 {
305 	struct lutil_tm tm;
306 	int n;
307 
308 	ldap_pvt_gettime( &tm );
309 
310 	n = snprintf( buf, len,
311 		"%4d%02d%02d%02d%02d%02d.%06dZ#%06x#%03x#%06x",
312 		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
313 		tm.tm_min, tm.tm_sec, tm.tm_usec, tm.tm_usub, replica, mod );
314 
315 	if( n < 0 ) return 0;
316 	return ( (size_t) n < len ) ? n : 0;
317 }
318 
319 #define BUFSTART (1024-32)
320 #define BUFMAX (32*1024-32)
321 
322 #if defined(LDAP_R_COMPILE)
323 static char *safe_realloc( char **buf, int len );
324 
325 #if !(defined(HAVE_GETHOSTBYNAME_R) && defined(HAVE_GETHOSTBYADDR_R))
326 static int copy_hostent( struct hostent *res,
327 	char **buf, struct hostent * src );
328 #endif
329 #endif
330 
331 int ldap_pvt_gethostbyname_a(
332 	const char *name,
333 	struct hostent *resbuf,
334 	char **buf,
335 	struct hostent **result,
336 	int *herrno_ptr )
337 {
338 #if defined( HAVE_GETHOSTBYNAME_R )
339 
340 # define NEED_SAFE_REALLOC 1
341 	int r=-1;
342 	int buflen=BUFSTART;
343 	*buf = NULL;
344 	for(;buflen<BUFMAX;) {
345 		if (safe_realloc( buf, buflen )==NULL)
346 			return r;
347 
348 #if (GETHOSTBYNAME_R_NARGS < 6)
349 		*result=gethostbyname_r( name, resbuf, *buf, buflen, herrno_ptr );
350 		r = (*result == NULL) ?  -1 : 0;
351 #else
352 		r = gethostbyname_r( name, resbuf, *buf,
353 			buflen, result, herrno_ptr );
354 #endif
355 
356 		Debug( LDAP_DEBUG_TRACE, "ldap_pvt_gethostbyname_a: host=%s, r=%d\n",
357 		       name, r, 0 );
358 
359 #ifdef NETDB_INTERNAL
360 		if ((r<0) &&
361 			(*herrno_ptr==NETDB_INTERNAL) &&
362 			(errno==ERANGE))
363 		{
364 			buflen*=2;
365 			continue;
366 	 	}
367 #endif
368 		return r;
369 	}
370 	return -1;
371 #elif defined( LDAP_R_COMPILE )
372 # define NEED_COPY_HOSTENT
373 	struct hostent *he;
374 	int	retval;
375 	*buf = NULL;
376 
377 	LDAP_MUTEX_LOCK( &ldap_int_resolv_mutex );
378 
379 	he = gethostbyname( name );
380 
381 	if (he==NULL) {
382 		*herrno_ptr = h_errno;
383 		retval = -1;
384 	} else if (copy_hostent( resbuf, buf, he )<0) {
385 		*herrno_ptr = -1;
386 		retval = -1;
387 	} else {
388 		*result = resbuf;
389 		retval = 0;
390 	}
391 
392 	LDAP_MUTEX_UNLOCK( &ldap_int_resolv_mutex );
393 
394 	return retval;
395 #else
396 	*buf = NULL;
397 	*result = gethostbyname( name );
398 
399 	if (*result!=NULL) {
400 		return 0;
401 	}
402 
403 	*herrno_ptr = h_errno;
404 
405 	return -1;
406 #endif
407 }
408 
409 #if !defined( HAVE_GETNAMEINFO ) && !defined( HAVE_HSTRERROR )
410 static const char *
411 hp_strerror( int err )
412 {
413 	switch (err) {
414 	case HOST_NOT_FOUND:	return _("Host not found (authoritative)");
415 	case TRY_AGAIN:			return _("Host not found (server fail?)");
416 	case NO_RECOVERY:		return _("Non-recoverable failure");
417 	case NO_DATA:			return _("No data of requested type");
418 #ifdef NETDB_INTERNAL
419 	case NETDB_INTERNAL:	return STRERROR( errno );
420 #endif
421 	}
422 	return _("Unknown resolver error");
423 }
424 #endif
425 
426 int ldap_pvt_get_hname(
427 	const struct sockaddr *sa,
428 	int len,
429 	char *name,
430 	int namelen,
431 	char **err )
432 {
433 	int rc;
434 #if defined( HAVE_GETNAMEINFO )
435 
436 	LDAP_MUTEX_LOCK( &ldap_int_resolv_mutex );
437 	rc = getnameinfo( sa, len, name, namelen, NULL, 0, 0 );
438 	LDAP_MUTEX_UNLOCK( &ldap_int_resolv_mutex );
439 	if ( rc ) *err = (char *)AC_GAI_STRERROR( rc );
440 	return rc;
441 
442 #else /* !HAVE_GETNAMEINFO */
443 	char *addr;
444 	int alen;
445 	struct hostent *hp = NULL;
446 #ifdef HAVE_GETHOSTBYADDR_R
447 	struct hostent hb;
448 	int buflen=BUFSTART, h_errno;
449 	char *buf=NULL;
450 #endif
451 
452 #ifdef LDAP_PF_INET6
453 	if (sa->sa_family == AF_INET6) {
454 		struct sockaddr_in6 *sin = (struct sockaddr_in6 *)sa;
455 		addr = (char *)&sin->sin6_addr;
456 		alen = sizeof(sin->sin6_addr);
457 	} else
458 #endif
459 	if (sa->sa_family == AF_INET) {
460 		struct sockaddr_in *sin = (struct sockaddr_in *)sa;
461 		addr = (char *)&sin->sin_addr;
462 		alen = sizeof(sin->sin_addr);
463 	} else {
464 		rc = NO_RECOVERY;
465 		*err = (char *)HSTRERROR( rc );
466 		return rc;
467 	}
468 #if defined( HAVE_GETHOSTBYADDR_R )
469 	for(;buflen<BUFMAX;) {
470 		if (safe_realloc( &buf, buflen )==NULL) {
471 			*err = (char *)STRERROR( ENOMEM );
472 			return ENOMEM;
473 		}
474 #if (GETHOSTBYADDR_R_NARGS < 8)
475 		hp=gethostbyaddr_r( addr, alen, sa->sa_family,
476 			&hb, buf, buflen, &h_errno );
477 		rc = (hp == NULL) ? -1 : 0;
478 #else
479 		rc = gethostbyaddr_r( addr, alen, sa->sa_family,
480 			&hb, buf, buflen,
481 			&hp, &h_errno );
482 #endif
483 #ifdef NETDB_INTERNAL
484 		if ((rc<0) &&
485 			(h_errno==NETDB_INTERNAL) &&
486 			(errno==ERANGE))
487 		{
488 			buflen*=2;
489 			continue;
490 		}
491 #endif
492 		break;
493 	}
494 	if (hp) {
495 		strncpy( name, hp->h_name, namelen );
496 	} else {
497 		*err = (char *)HSTRERROR( h_errno );
498 	}
499 	LDAP_FREE(buf);
500 #else /* HAVE_GETHOSTBYADDR_R */
501 
502 	LDAP_MUTEX_LOCK( &ldap_int_resolv_mutex );
503 	hp = gethostbyaddr( addr, alen, sa->sa_family );
504 	if (hp) {
505 		strncpy( name, hp->h_name, namelen );
506 		rc = 0;
507 	} else {
508 		rc = h_errno;
509 		*err = (char *)HSTRERROR( h_errno );
510 	}
511 	LDAP_MUTEX_UNLOCK( &ldap_int_resolv_mutex );
512 
513 #endif	/* !HAVE_GETHOSTBYADDR_R */
514 	return rc;
515 #endif	/* !HAVE_GETNAMEINFO */
516 }
517 
518 int ldap_pvt_gethostbyaddr_a(
519 	const char *addr,
520 	int len,
521 	int type,
522 	struct hostent *resbuf,
523 	char **buf,
524 	struct hostent **result,
525 	int *herrno_ptr )
526 {
527 #if defined( HAVE_GETHOSTBYADDR_R )
528 
529 # undef NEED_SAFE_REALLOC
530 # define NEED_SAFE_REALLOC
531 	int r=-1;
532 	int buflen=BUFSTART;
533 	*buf = NULL;
534 	for(;buflen<BUFMAX;) {
535 		if (safe_realloc( buf, buflen )==NULL)
536 			return r;
537 #if (GETHOSTBYADDR_R_NARGS < 8)
538 		*result=gethostbyaddr_r( addr, len, type,
539 			resbuf, *buf, buflen, herrno_ptr );
540 		r = (*result == NULL) ? -1 : 0;
541 #else
542 		r = gethostbyaddr_r( addr, len, type,
543 			resbuf, *buf, buflen,
544 			result, herrno_ptr );
545 #endif
546 
547 #ifdef NETDB_INTERNAL
548 		if ((r<0) &&
549 			(*herrno_ptr==NETDB_INTERNAL) &&
550 			(errno==ERANGE))
551 		{
552 			buflen*=2;
553 			continue;
554 		}
555 #endif
556 		return r;
557 	}
558 	return -1;
559 #elif defined( LDAP_R_COMPILE )
560 # undef NEED_COPY_HOSTENT
561 # define NEED_COPY_HOSTENT
562 	struct hostent *he;
563 	int	retval;
564 	*buf = NULL;
565 
566 	LDAP_MUTEX_LOCK( &ldap_int_resolv_mutex );
567 	he = gethostbyaddr( addr, len, type );
568 
569 	if (he==NULL) {
570 		*herrno_ptr = h_errno;
571 		retval = -1;
572 	} else if (copy_hostent( resbuf, buf, he )<0) {
573 		*herrno_ptr = -1;
574 		retval = -1;
575 	} else {
576 		*result = resbuf;
577 		retval = 0;
578 	}
579 	LDAP_MUTEX_UNLOCK( &ldap_int_resolv_mutex );
580 
581 	return retval;
582 
583 #else /* gethostbyaddr() */
584 	*buf = NULL;
585 	*result = gethostbyaddr( addr, len, type );
586 
587 	if (*result!=NULL) {
588 		return 0;
589 	}
590 	return -1;
591 #endif
592 }
593 /*
594  * ldap_int_utils_init() should be called before any other function.
595  */
596 
597 void ldap_int_utils_init( void )
598 {
599 	static int done=0;
600 	if (done)
601 	  return;
602 	done=1;
603 
604 #ifdef LDAP_R_COMPILE
605 #if !defined( USE_CTIME_R ) && !defined( HAVE_REENTRANT_FUNCTIONS )
606 	ldap_pvt_thread_mutex_init( &ldap_int_ctime_mutex );
607 #endif
608 #if !defined( USE_GMTIME_R ) && !defined( USE_LOCALTIME_R )
609 	ldap_pvt_thread_mutex_init( &ldap_int_gmtime_mutex );
610 #endif
611 	ldap_pvt_thread_mutex_init( &ldap_int_resolv_mutex );
612 
613 	ldap_pvt_thread_mutex_init( &ldap_int_hostname_mutex );
614 
615 	ldap_pvt_thread_mutex_init( &ldap_int_gettime_mutex );
616 
617 #ifdef HAVE_GSSAPI
618 	ldap_pvt_thread_mutex_init( &ldap_int_gssapi_mutex );
619 #endif
620 #endif
621 
622 	/* call other module init functions here... */
623 }
624 
625 #if defined( NEED_COPY_HOSTENT )
626 # undef NEED_SAFE_REALLOC
627 #define NEED_SAFE_REALLOC
628 
629 static char *cpy_aliases(
630 	char ***tgtio,
631 	char *buf,
632 	char **src )
633 {
634 	int len;
635 	char **tgt=*tgtio;
636 	for( ; (*src) ; src++ ) {
637 		len = strlen( *src ) + 1;
638 		AC_MEMCPY( buf, *src, len );
639 		*tgt++=buf;
640 		buf+=len;
641 	}
642 	*tgtio=tgt;
643 	return buf;
644 }
645 
646 static char *cpy_addresses(
647 	char ***tgtio,
648 	char *buf,
649 	char **src,
650 	int len )
651 {
652    	char **tgt=*tgtio;
653 	for( ; (*src) ; src++ ) {
654 		AC_MEMCPY( buf, *src, len );
655 		*tgt++=buf;
656 		buf+=len;
657 	}
658 	*tgtio=tgt;
659 	return buf;
660 }
661 
662 static int copy_hostent(
663 	struct hostent *res,
664 	char **buf,
665 	struct hostent * src )
666 {
667 	char	**p;
668 	char	**tp;
669 	char	*tbuf;
670 	int	name_len;
671 	int	n_alias=0;
672 	int	total_alias_len=0;
673 	int	n_addr=0;
674 	int	total_addr_len=0;
675 	int	total_len;
676 
677 	/* calculate the size needed for the buffer */
678 	name_len = strlen( src->h_name ) + 1;
679 
680 	if( src->h_aliases != NULL ) {
681 		for( p = src->h_aliases; (*p) != NULL; p++ ) {
682 			total_alias_len += strlen( *p ) + 1;
683 			n_alias++;
684 		}
685 	}
686 
687 	if( src->h_addr_list != NULL ) {
688 		for( p = src->h_addr_list; (*p) != NULL; p++ ) {
689 			n_addr++;
690 		}
691 		total_addr_len = n_addr * src->h_length;
692 	}
693 
694 	total_len = (n_alias + n_addr + 2) * sizeof( char * ) +
695 		total_addr_len + total_alias_len + name_len;
696 
697 	if (safe_realloc( buf, total_len )) {
698 		tp = (char **) *buf;
699 		tbuf = *buf + (n_alias + n_addr + 2) * sizeof( char * );
700 		AC_MEMCPY( res, src, sizeof( struct hostent ) );
701 		/* first the name... */
702 		AC_MEMCPY( tbuf, src->h_name, name_len );
703 		res->h_name = tbuf; tbuf+=name_len;
704 		/* now the aliases */
705 		res->h_aliases = tp;
706 		if ( src->h_aliases != NULL ) {
707 			tbuf = cpy_aliases( &tp, tbuf, src->h_aliases );
708 		}
709 		*tp++=NULL;
710 		/* finally the addresses */
711 		res->h_addr_list = tp;
712 		if ( src->h_addr_list != NULL ) {
713 			tbuf = cpy_addresses( &tp, tbuf, src->h_addr_list, src->h_length );
714 		}
715 		*tp++=NULL;
716 		return 0;
717 	}
718 	return -1;
719 }
720 #endif
721 
722 #if defined( NEED_SAFE_REALLOC )
723 static char *safe_realloc( char **buf, int len )
724 {
725 	char *tmpbuf;
726 	tmpbuf = LDAP_REALLOC( *buf, len );
727 	if (tmpbuf) {
728 		*buf=tmpbuf;
729 	}
730 	return tmpbuf;
731 }
732 #endif
733 
734 char * ldap_pvt_get_fqdn( char *name )
735 {
736 	char *fqdn, *ha_buf;
737 	char hostbuf[MAXHOSTNAMELEN+1];
738 	struct hostent *hp, he_buf;
739 	int rc, local_h_errno;
740 
741 	if( name == NULL ) {
742 		if( gethostname( hostbuf, MAXHOSTNAMELEN ) == 0 ) {
743 			hostbuf[MAXHOSTNAMELEN] = '\0';
744 			name = hostbuf;
745 		} else {
746 			name = "localhost";
747 		}
748 	}
749 
750 	rc = ldap_pvt_gethostbyname_a( name,
751 		&he_buf, &ha_buf, &hp, &local_h_errno );
752 
753 	if( rc < 0 || hp == NULL || hp->h_name == NULL ) {
754 		fqdn = LDAP_STRDUP( name );
755 	} else {
756 		fqdn = LDAP_STRDUP( hp->h_name );
757 	}
758 
759 	LDAP_FREE( ha_buf );
760 	return fqdn;
761 }
762 
763 #if ( defined( HAVE_GETADDRINFO ) || defined( HAVE_GETNAMEINFO ) ) \
764 	&& !defined( HAVE_GAI_STRERROR )
765 char *ldap_pvt_gai_strerror (int code) {
766 	static struct {
767 		int code;
768 		const char *msg;
769 	} values[] = {
770 #ifdef EAI_ADDRFAMILY
771 		{ EAI_ADDRFAMILY, N_("Address family for hostname not supported") },
772 #endif
773 		{ EAI_AGAIN, N_("Temporary failure in name resolution") },
774 		{ EAI_BADFLAGS, N_("Bad value for ai_flags") },
775 		{ EAI_FAIL, N_("Non-recoverable failure in name resolution") },
776 		{ EAI_FAMILY, N_("ai_family not supported") },
777 		{ EAI_MEMORY, N_("Memory allocation failure") },
778 #ifdef EAI_NODATA
779 		{ EAI_NODATA, N_("No address associated with hostname") },
780 #endif
781 		{ EAI_NONAME, N_("Name or service not known") },
782 		{ EAI_SERVICE, N_("Servname not supported for ai_socktype") },
783 		{ EAI_SOCKTYPE, N_("ai_socktype not supported") },
784 #ifdef EAI_SYSTEM
785 		{ EAI_SYSTEM, N_("System error") },
786 #endif
787 		{ 0, NULL }
788 	};
789 
790 	int i;
791 
792 	for ( i = 0; values[i].msg != NULL; i++ ) {
793 		if ( values[i].code == code ) {
794 			return (char *) _(values[i].msg);
795 		}
796 	}
797 
798 	return _("Unknown error");
799 }
800 #endif
801