1/* io.c - ber general i/o routines */
2/* $OpenLDAP$ */
3/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
4 *
5 * Copyright 1998-2011 The OpenLDAP Foundation.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted only as authorized by the OpenLDAP
10 * Public License.
11 *
12 * A copy of this license is available in the file LICENSE in the
13 * top-level directory of the distribution or, alternatively, at
14 * <http://www.OpenLDAP.org/license.html>.
15 */
16/* Portions Copyright (c) 1990 Regents of the University of Michigan.
17 * All rights reserved.
18 *
19 * Redistribution and use in source and binary forms are permitted
20 * provided that this notice is preserved and that due credit is given
21 * to the University of Michigan at Ann Arbor. The name of the University
22 * may not be used to endorse or promote products derived from this
23 * software without specific prior written permission. This software
24 * is provided ``as is'' without express or implied warranty.
25 */
26/* ACKNOWLEDGEMENTS:
27 * This work was originally developed by the University of Michigan
28 * (as part of U-MICH LDAP).
29 */
30
31#include "portable.h"
32
33#include <stdio.h>
34
35#include <ac/stdlib.h>
36
37#include <ac/ctype.h>
38#include <ac/errno.h>
39#include <ac/socket.h>
40#include <ac/string.h>
41#include <ac/unistd.h>
42
43#ifdef HAVE_IO_H
44#include <io.h>
45#endif
46
47#include "lber-int.h"
48#include "ldap_log.h"
49
50ber_slen_t
51ber_skip_data(
52	BerElement *ber,
53	ber_len_t len )
54{
55	ber_len_t	actuallen, nleft;
56
57	assert( ber != NULL );
58	assert( LBER_VALID( ber ) );
59
60	nleft = ber_pvt_ber_remaining( ber );
61	actuallen = nleft < len ? nleft : len;
62	ber->ber_ptr += actuallen;
63	ber->ber_tag = *(unsigned char *)ber->ber_ptr;
64
65	return( (ber_slen_t) actuallen );
66}
67
68/*
69 * Read from the ber buffer.  The caller must maintain ber->ber_tag.
70 * Do not use to read whole tags.  See ber_get_tag() and ber_skip_data().
71 */
72ber_slen_t
73ber_read(
74	BerElement *ber,
75	char *buf,
76	ber_len_t len )
77{
78	ber_len_t	actuallen, nleft;
79
80	assert( ber != NULL );
81	assert( buf != NULL );
82	assert( LBER_VALID( ber ) );
83
84	nleft = ber_pvt_ber_remaining( ber );
85	actuallen = nleft < len ? nleft : len;
86
87	AC_MEMCPY( buf, ber->ber_ptr, actuallen );
88
89	ber->ber_ptr += actuallen;
90
91	return( (ber_slen_t) actuallen );
92}
93
94/*
95 * Write to the ber buffer.
96 * Note that ber_start_seqorset/ber_put_seqorset() bypass ber_write().
97 */
98ber_slen_t
99ber_write(
100	BerElement *ber,
101	LDAP_CONST char *buf,
102	ber_len_t len,
103	int zero )	/* nonzero is unsupported from OpenLDAP 2.4.18 */
104{
105	char **p;
106
107	assert( ber != NULL );
108	assert( buf != NULL );
109	assert( LBER_VALID( ber ) );
110
111	if ( zero != 0 ) {
112		ber_log_printf( LDAP_DEBUG_ANY, ber->ber_debug, "%s",
113			"ber_write: nonzero 4th argument not supported\n" );
114		return( -1 );
115	}
116
117	p = ber->ber_sos_ptr == NULL ? &ber->ber_ptr : &ber->ber_sos_ptr;
118	if ( len > (ber_len_t) (ber->ber_end - *p) ) {
119		if ( ber_realloc( ber, len ) != 0 ) return( -1 );
120	}
121	AC_MEMCPY( *p, buf, len );
122	*p += len;
123
124	return( (ber_slen_t) len );
125}
126
127/* Resize the ber buffer */
128int
129ber_realloc( BerElement *ber, ber_len_t len )
130{
131	ber_len_t	total, offset, sos_offset;
132	char		*buf;
133
134	assert( ber != NULL );
135	assert( LBER_VALID( ber ) );
136
137	/* leave room for ber_flatten() to \0-terminate ber_buf */
138	if ( ++len == 0 ) {
139		return( -1 );
140	}
141
142	total = ber_pvt_ber_total( ber );
143
144#define LBER_EXBUFSIZ	4060 /* a few words less than 2^N for binary buddy */
145#if defined( LBER_EXBUFSIZ ) && LBER_EXBUFSIZ > 0
146# ifndef notdef
147	/* don't realloc by small amounts */
148	total += len < LBER_EXBUFSIZ ? LBER_EXBUFSIZ : len;
149# else
150	{	/* not sure what value this adds.  reduce fragmentation? */
151		ber_len_t have = (total + (LBER_EXBUFSIZE - 1)) / LBER_EXBUFSIZ;
152		ber_len_t need = (len + (LBER_EXBUFSIZ - 1)) / LBER_EXBUFSIZ;
153		total = ( have + need ) * LBER_EXBUFSIZ;
154	}
155# endif
156#else
157	total += len;	/* realloc just what's needed */
158#endif
159
160	if ( total < len || total > (ber_len_t)-1 / 2 /* max ber_slen_t */ ) {
161		return( -1 );
162	}
163
164	buf = ber->ber_buf;
165	offset = ber->ber_ptr - buf;
166	sos_offset = ber->ber_sos_ptr ? ber->ber_sos_ptr - buf : 0;
167	/* if ber_sos_ptr != NULL, it is > ber_buf so that sos_offset > 0 */
168
169	buf = (char *) ber_memrealloc_x( buf, total, ber->ber_memctx );
170	if ( buf == NULL ) {
171		return( -1 );
172	}
173
174	ber->ber_buf = buf;
175	ber->ber_end = buf + total;
176	ber->ber_ptr = buf + offset;
177	if ( sos_offset )
178		ber->ber_sos_ptr = buf + sos_offset;
179
180	return( 0 );
181}
182
183void
184ber_free_buf( BerElement *ber )
185{
186	assert( LBER_VALID( ber ) );
187
188	if ( ber->ber_buf) ber_memfree_x( ber->ber_buf, ber->ber_memctx );
189
190	ber->ber_buf = NULL;
191	ber->ber_sos_ptr = NULL;
192	ber->ber_valid = LBER_UNINITIALIZED;
193}
194
195void
196ber_free( BerElement *ber, int freebuf )
197{
198	if( ber == NULL ) {
199		LDAP_MEMORY_DEBUG_ASSERT( ber != NULL );
200		return;
201	}
202
203	if( freebuf ) ber_free_buf( ber );
204
205	ber_memfree_x( (char *) ber, ber->ber_memctx );
206}
207
208int
209ber_flush( Sockbuf *sb, BerElement *ber, int freeit )
210{
211	return ber_flush2( sb, ber,
212		freeit ? LBER_FLUSH_FREE_ON_SUCCESS
213			: LBER_FLUSH_FREE_NEVER );
214}
215
216int
217ber_flush2( Sockbuf *sb, BerElement *ber, int freeit )
218{
219	ber_len_t	towrite;
220	ber_slen_t	rc;
221
222	assert( sb != NULL );
223	assert( ber != NULL );
224	assert( SOCKBUF_VALID( sb ) );
225	assert( LBER_VALID( ber ) );
226
227	if ( ber->ber_rwptr == NULL ) {
228		ber->ber_rwptr = ber->ber_buf;
229	}
230	towrite = ber->ber_ptr - ber->ber_rwptr;
231
232	if ( sb->sb_debug ) {
233		ber_log_printf( LDAP_DEBUG_TRACE, sb->sb_debug,
234			"ber_flush2: %ld bytes to sd %ld%s\n",
235			towrite, (long) sb->sb_fd,
236			ber->ber_rwptr != ber->ber_buf ?  " (re-flush)" : "" );
237		ber_log_bprint( LDAP_DEBUG_BER, sb->sb_debug,
238			ber->ber_rwptr, towrite );
239	}
240
241	while ( towrite > 0 ) {
242#ifdef LBER_TRICKLE
243		sleep(1);
244		rc = ber_int_sb_write( sb, ber->ber_rwptr, 1 );
245#else
246		rc = ber_int_sb_write( sb, ber->ber_rwptr, towrite );
247#endif
248		if ( rc <= 0 ) {
249			if ( freeit & LBER_FLUSH_FREE_ON_ERROR ) ber_free( ber, 1 );
250			return -1;
251		}
252		towrite -= rc;
253		ber->ber_rwptr += rc;
254	}
255
256	if ( freeit & LBER_FLUSH_FREE_ON_SUCCESS ) ber_free( ber, 1 );
257
258	return 0;
259}
260
261BerElement *
262ber_alloc_t( int options )
263{
264	BerElement	*ber;
265
266	ber = (BerElement *) LBER_CALLOC( 1, sizeof(BerElement) );
267
268	if ( ber == NULL ) {
269		return NULL;
270	}
271
272	ber->ber_valid = LBER_VALID_BERELEMENT;
273	ber->ber_tag = LBER_DEFAULT;
274	ber->ber_options = options;
275	ber->ber_debug = ber_int_debug;
276
277	assert( LBER_VALID( ber ) );
278	return ber;
279}
280
281BerElement *
282ber_alloc( void )	/* deprecated */
283{
284	return ber_alloc_t( 0 );
285}
286
287BerElement *
288der_alloc( void )	/* deprecated */
289{
290	return ber_alloc_t( LBER_USE_DER );
291}
292
293BerElement *
294ber_dup( BerElement *ber )
295{
296	BerElement	*new;
297
298	assert( ber != NULL );
299	assert( LBER_VALID( ber ) );
300
301	if ( (new = ber_alloc_t( ber->ber_options )) == NULL ) {
302		return NULL;
303	}
304
305	*new = *ber;
306
307	assert( LBER_VALID( new ) );
308	return( new );
309}
310
311
312void
313ber_init2( BerElement *ber, struct berval *bv, int options )
314{
315	assert( ber != NULL );
316
317	(void) memset( (char *)ber, '\0', sizeof( BerElement ));
318	ber->ber_valid = LBER_VALID_BERELEMENT;
319	ber->ber_tag = LBER_DEFAULT;
320	ber->ber_options = (char) options;
321	ber->ber_debug = ber_int_debug;
322
323	if ( bv != NULL ) {
324		ber->ber_buf = bv->bv_val;
325		ber->ber_ptr = ber->ber_buf;
326		ber->ber_end = ber->ber_buf + bv->bv_len;
327	}
328
329	assert( LBER_VALID( ber ) );
330}
331
332/* OLD U-Mich ber_init() */
333void
334ber_init_w_nullc( BerElement *ber, int options )
335{
336	ber_init2( ber, NULL, options );
337}
338
339/* New C-API ber_init() */
340/* This function constructs a BerElement containing a copy
341** of the data in the bv argument.
342*/
343BerElement *
344ber_init( struct berval *bv )
345{
346	BerElement *ber;
347
348	assert( bv != NULL );
349
350	if ( bv == NULL ) {
351		return NULL;
352	}
353
354	ber = ber_alloc_t( 0 );
355
356	if( ber == NULL ) {
357		/* allocation failed */
358		return NULL;
359	}
360
361	/* copy the data */
362	if ( ((ber_len_t) ber_write ( ber, bv->bv_val, bv->bv_len, 0 ))
363		!= bv->bv_len )
364	{
365		/* write failed, so free and return NULL */
366		ber_free( ber, 1 );
367		return NULL;
368	}
369
370	ber_reset( ber, 1 );	/* reset the pointer to the start of the buffer */
371	return ber;
372}
373
374/* New C-API ber_flatten routine */
375/* This routine allocates a struct berval whose contents are a BER
376** encoding taken from the ber argument.  The bvPtr pointer points to
377** the returned berval.
378**
379** ber_flatten2 is the same, but uses a struct berval passed by
380** the caller. If alloc is 0 the returned bv uses the ber buf directly.
381*/
382int ber_flatten2(
383	BerElement *ber,
384	struct berval *bv,
385	int alloc )
386{
387	assert( bv != NULL );
388
389	if ( bv == NULL ) {
390		return -1;
391	}
392
393	if ( ber == NULL ) {
394		/* ber is null, create an empty berval */
395		bv->bv_val = NULL;
396		bv->bv_len = 0;
397
398	} else if ( ber->ber_sos_ptr != NULL ) {
399		/* unmatched "{" and "}" */
400		return -1;
401
402	} else {
403		/* copy the berval */
404		ber_len_t len = ber_pvt_ber_write( ber );
405
406		if ( alloc ) {
407			bv->bv_val = (char *) ber_memalloc_x( len + 1, ber->ber_memctx );
408			if ( bv->bv_val == NULL ) {
409				return -1;
410			}
411			AC_MEMCPY( bv->bv_val, ber->ber_buf, len );
412			bv->bv_val[len] = '\0';
413		} else if ( ber->ber_buf != NULL ) {
414			bv->bv_val = ber->ber_buf;
415			bv->bv_val[len] = '\0';
416		} else {
417			bv->bv_val = "";
418		}
419		bv->bv_len = len;
420	}
421	return 0;
422}
423
424int ber_flatten(
425	BerElement *ber,
426	struct berval **bvPtr)
427{
428	struct berval *bv;
429	int rc;
430
431	assert( bvPtr != NULL );
432
433	if(bvPtr == NULL) {
434		return -1;
435	}
436
437	bv = ber_memalloc_x( sizeof(struct berval), ber->ber_memctx );
438	if ( bv == NULL ) {
439		return -1;
440	}
441	rc = ber_flatten2(ber, bv, 1);
442	if (rc == -1) {
443		ber_memfree_x(bv, ber->ber_memctx);
444	} else {
445		*bvPtr = bv;
446	}
447	return rc;
448}
449
450void
451ber_reset( BerElement *ber, int was_writing )
452{
453	assert( ber != NULL );
454	assert( LBER_VALID( ber ) );
455
456	if ( was_writing ) {
457		ber->ber_end = ber->ber_ptr;
458		ber->ber_ptr = ber->ber_buf;
459
460	} else {
461		ber->ber_ptr = ber->ber_end;
462	}
463
464	ber->ber_rwptr = NULL;
465}
466
467/*
468 * A rewrite of ber_get_next that can safely be called multiple times
469 * for the same packet. It will simply continue where it stopped until
470 * a full packet is read.
471 */
472
473#define LENSIZE	4
474
475ber_tag_t
476ber_get_next(
477	Sockbuf *sb,
478	ber_len_t *len,
479	BerElement *ber )
480{
481	assert( sb != NULL );
482	assert( len != NULL );
483	assert( ber != NULL );
484	assert( SOCKBUF_VALID( sb ) );
485	assert( LBER_VALID( ber ) );
486
487	if ( ber->ber_debug & LDAP_DEBUG_TRACE ) {
488		ber_log_printf( LDAP_DEBUG_TRACE, ber->ber_debug,
489			"ber_get_next\n" );
490	}
491
492	/*
493	 * Any ber element looks like this: tag length contents.
494	 * Assuming everything's ok, we return the tag byte (we
495	 * can assume a single byte), return the length in len,
496	 * and the rest of the undecoded element in buf.
497	 *
498	 * Assumptions:
499	 *	1) small tags (less than 128)
500	 *	2) definite lengths
501	 *	3) primitive encodings used whenever possible
502	 *
503	 * The code also handles multi-byte tags. The first few bytes
504	 * of the message are read to check for multi-byte tags and
505	 * lengths. These bytes are temporarily stored in the ber_tag,
506	 * ber_len, and ber_usertag fields of the berelement until
507	 * tag/len parsing is complete. After this parsing, any leftover
508	 * bytes and the rest of the message are copied into the ber_buf.
509	 *
510	 * We expect tag and len to be at most 32 bits wide.
511	 */
512
513	if (ber->ber_rwptr == NULL) {
514		assert( ber->ber_buf == NULL );
515		ber->ber_rwptr = (char *) &ber->ber_len-1;
516		ber->ber_ptr = ber->ber_rwptr;
517		ber->ber_tag = 0;
518	}
519
520	while (ber->ber_rwptr > (char *)&ber->ber_tag && ber->ber_rwptr <
521		(char *)&ber->ber_len + LENSIZE*2) {
522		ber_slen_t sblen;
523		char buf[sizeof(ber->ber_len)-1];
524		ber_len_t tlen = 0;
525
526		/* The tag & len can be at most 9 bytes; we try to read up to 8 here */
527		sock_errset(0);
528		sblen=((char *)&ber->ber_len + LENSIZE*2 - 1)-ber->ber_rwptr;
529		/* Trying to read the last len byte of a 9 byte tag+len */
530		if (sblen<1)
531			sblen = 1;
532		sblen=ber_int_sb_read( sb, ber->ber_rwptr, sblen );
533		if (sblen<=0) return LBER_DEFAULT;
534		ber->ber_rwptr += sblen;
535
536		/* We got at least one byte, try to parse the tag. */
537		if (ber->ber_ptr == (char *)&ber->ber_len-1) {
538			ber_tag_t tag;
539			unsigned char *p = (unsigned char *)ber->ber_ptr;
540			tag = *p++;
541			if ((tag & LBER_BIG_TAG_MASK) == LBER_BIG_TAG_MASK) {
542				ber_len_t i;
543				for (i=1; (char *)p<ber->ber_rwptr; i++) {
544					tag <<= 8;
545					tag |= *p++;
546					if (!(tag & LBER_MORE_TAG_MASK))
547						break;
548					/* Is the tag too big? */
549					if (i == sizeof(ber_tag_t)-1) {
550						sock_errset(ERANGE);
551						return LBER_DEFAULT;
552					}
553				}
554				/* Did we run out of bytes? */
555				if ((char *)p == ber->ber_rwptr) {
556					sock_errset(EWOULDBLOCK);
557					return LBER_DEFAULT;
558				}
559			}
560			ber->ber_tag = tag;
561			ber->ber_ptr = (char *)p;
562		}
563
564		if ( ber->ber_ptr == ber->ber_rwptr ) {
565			sock_errset(EWOULDBLOCK);
566			return LBER_DEFAULT;
567		}
568
569		/* Now look for the length */
570		if (*ber->ber_ptr & 0x80) {	/* multi-byte */
571			int i;
572			unsigned char *p = (unsigned char *)ber->ber_ptr;
573			int llen = *p++ & 0x7f;
574			if (llen > LENSIZE) {
575				sock_errset(ERANGE);
576				return LBER_DEFAULT;
577			}
578			/* Not enough bytes? */
579			if (ber->ber_rwptr - (char *)p < llen) {
580				sock_errset(EWOULDBLOCK);
581				return LBER_DEFAULT;
582			}
583			for (i=0; i<llen; i++) {
584				tlen <<=8;
585				tlen |= *p++;
586			}
587			ber->ber_ptr = (char *)p;
588		} else {
589			tlen = *(unsigned char *)ber->ber_ptr++;
590		}
591
592		/* Are there leftover data bytes inside ber->ber_len? */
593		if (ber->ber_ptr < (char *)&ber->ber_usertag) {
594			if (ber->ber_rwptr < (char *)&ber->ber_usertag) {
595				sblen = ber->ber_rwptr - ber->ber_ptr;
596			} else {
597				sblen = (char *)&ber->ber_usertag - ber->ber_ptr;
598			}
599			AC_MEMCPY(buf, ber->ber_ptr, sblen);
600			ber->ber_ptr += sblen;
601		} else {
602			sblen = 0;
603		}
604		ber->ber_len = tlen;
605
606		/* now fill the buffer. */
607
608		/* make sure length is reasonable */
609		if ( ber->ber_len == 0 ) {
610			sock_errset(ERANGE);
611			return LBER_DEFAULT;
612		}
613
614		if ( sb->sb_max_incoming && ber->ber_len > sb->sb_max_incoming ) {
615			ber_log_printf( LDAP_DEBUG_CONNS, ber->ber_debug,
616				"ber_get_next: sockbuf_max_incoming exceeded "
617				"(%ld > %ld)\n", ber->ber_len, sb->sb_max_incoming );
618			sock_errset(ERANGE);
619			return LBER_DEFAULT;
620		}
621
622		if (ber->ber_buf==NULL) {
623			ber_len_t l = ber->ber_rwptr - ber->ber_ptr;
624			/* ber->ber_ptr is always <= ber->ber->ber_rwptr.
625			 * make sure ber->ber_len agrees with what we've
626			 * already read.
627			 */
628			if ( ber->ber_len < sblen + l ) {
629				sock_errset(ERANGE);
630				return LBER_DEFAULT;
631			}
632			ber->ber_buf = (char *) ber_memalloc_x( ber->ber_len + 1, ber->ber_memctx );
633			if (ber->ber_buf==NULL) {
634				return LBER_DEFAULT;
635			}
636			ber->ber_end = ber->ber_buf + ber->ber_len;
637			if (sblen) {
638				AC_MEMCPY(ber->ber_buf, buf, sblen);
639			}
640			if (l > 0) {
641				AC_MEMCPY(ber->ber_buf + sblen, ber->ber_ptr, l);
642				sblen += l;
643			}
644			*ber->ber_end = '\0';
645			ber->ber_ptr = ber->ber_buf;
646			ber->ber_usertag = 0;
647			if ((ber_len_t)sblen == ber->ber_len) {
648				goto done;
649			}
650			ber->ber_rwptr = ber->ber_buf + sblen;
651		}
652	}
653
654	if ((ber->ber_rwptr>=ber->ber_buf) && (ber->ber_rwptr<ber->ber_end)) {
655		ber_slen_t res;
656		ber_slen_t to_go;
657
658		to_go = ber->ber_end - ber->ber_rwptr;
659		assert( to_go > 0 );
660
661		sock_errset(0);
662		res = ber_int_sb_read( sb, ber->ber_rwptr, to_go );
663		if (res<=0) return LBER_DEFAULT;
664		ber->ber_rwptr+=res;
665
666		if (res<to_go) {
667			sock_errset(EWOULDBLOCK);
668			return LBER_DEFAULT;
669		}
670done:
671		ber->ber_rwptr = NULL;
672		*len = ber->ber_len;
673		if ( ber->ber_debug ) {
674			ber_log_printf( LDAP_DEBUG_TRACE, ber->ber_debug,
675				"ber_get_next: tag 0x%lx len %ld contents:\n",
676				ber->ber_tag, ber->ber_len );
677			ber_log_dump( LDAP_DEBUG_BER, ber->ber_debug, ber, 1 );
678		}
679		return (ber->ber_tag);
680	}
681
682	assert( 0 ); /* ber structure is messed up ?*/
683	return LBER_DEFAULT;
684}
685
686char *
687ber_start( BerElement* ber )
688{
689	return ber->ber_buf;
690}
691
692int
693ber_len( BerElement* ber )
694{
695	return ( ber->ber_end - ber->ber_buf );
696}
697
698int
699ber_ptrlen( BerElement* ber )
700{
701	return ( ber->ber_ptr - ber->ber_buf );
702}
703
704void
705ber_rewind ( BerElement * ber )
706{
707	ber->ber_rwptr = NULL;
708	ber->ber_sos_ptr = NULL;
709	ber->ber_end = ber->ber_ptr;
710	ber->ber_ptr = ber->ber_buf;
711#if 0	/* TODO: Should we add this? */
712	ber->ber_tag = LBER_DEFAULT;
713	ber->ber_usertag = 0;
714#endif
715}
716
717int
718ber_remaining( BerElement * ber )
719{
720	return ber_pvt_ber_remaining( ber );
721}
722