xref: /reactos/sdk/lib/3rdparty/libxml2/uri.c (revision 7e22dc05)
1 /**
2  * uri.c: set of generic URI related routines
3  *
4  * Reference: RFCs 3986, 2732 and 2373
5  *
6  * See Copyright for the status of this software.
7  *
8  * daniel@veillard.com
9  */
10 
11 #define IN_LIBXML
12 #include "libxml.h"
13 
14 #include <limits.h>
15 #include <string.h>
16 
17 #include <libxml/xmlmemory.h>
18 #include <libxml/uri.h>
19 #include <libxml/globals.h>
20 #include <libxml/xmlerror.h>
21 
22 /**
23  * MAX_URI_LENGTH:
24  *
25  * The definition of the URI regexp in the above RFC has no size limit
26  * In practice they are usually relatively short except for the
27  * data URI scheme as defined in RFC 2397. Even for data URI the usual
28  * maximum size before hitting random practical limits is around 64 KB
29  * and 4KB is usually a maximum admitted limit for proper operations.
30  * The value below is more a security limit than anything else and
31  * really should never be hit by 'normal' operations
32  * Set to 1 MByte in 2012, this is only enforced on output
33  */
34 #define MAX_URI_LENGTH 1024 * 1024
35 
36 static void
37 xmlURIErrMemory(const char *extra)
38 {
39     if (extra)
40         __xmlRaiseError(NULL, NULL, NULL,
41                         NULL, NULL, XML_FROM_URI,
42                         XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0,
43                         extra, NULL, NULL, 0, 0,
44                         "Memory allocation failed : %s\n", extra);
45     else
46         __xmlRaiseError(NULL, NULL, NULL,
47                         NULL, NULL, XML_FROM_URI,
48                         XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0,
49                         NULL, NULL, NULL, 0, 0,
50                         "Memory allocation failed\n");
51 }
52 
53 static void xmlCleanURI(xmlURIPtr uri);
54 
55 /*
56  * Old rule from 2396 used in legacy handling code
57  * alpha    = lowalpha | upalpha
58  */
59 #define IS_ALPHA(x) (IS_LOWALPHA(x) || IS_UPALPHA(x))
60 
61 
62 /*
63  * lowalpha = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" |
64  *            "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" | "s" | "t" |
65  *            "u" | "v" | "w" | "x" | "y" | "z"
66  */
67 
68 #define IS_LOWALPHA(x) (((x) >= 'a') && ((x) <= 'z'))
69 
70 /*
71  * upalpha = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" |
72  *           "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" |
73  *           "U" | "V" | "W" | "X" | "Y" | "Z"
74  */
75 #define IS_UPALPHA(x) (((x) >= 'A') && ((x) <= 'Z'))
76 
77 #ifdef IS_DIGIT
78 #undef IS_DIGIT
79 #endif
80 /*
81  * digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
82  */
83 #define IS_DIGIT(x) (((x) >= '0') && ((x) <= '9'))
84 
85 /*
86  * alphanum = alpha | digit
87  */
88 
89 #define IS_ALPHANUM(x) (IS_ALPHA(x) || IS_DIGIT(x))
90 
91 /*
92  * mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
93  */
94 
95 #define IS_MARK(x) (((x) == '-') || ((x) == '_') || ((x) == '.') ||     \
96     ((x) == '!') || ((x) == '~') || ((x) == '*') || ((x) == '\'') ||    \
97     ((x) == '(') || ((x) == ')'))
98 
99 /*
100  * unwise = "{" | "}" | "|" | "\" | "^" | "`"
101  */
102 
103 #define IS_UNWISE(p)                                                    \
104       (((*(p) == '{')) || ((*(p) == '}')) || ((*(p) == '|')) ||         \
105        ((*(p) == '\\')) || ((*(p) == '^')) || ((*(p) == '[')) ||        \
106        ((*(p) == ']')) || ((*(p) == '`')))
107 /*
108  * reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | "," |
109  *            "[" | "]"
110  */
111 
112 #define IS_RESERVED(x) (((x) == ';') || ((x) == '/') || ((x) == '?') || \
113         ((x) == ':') || ((x) == '@') || ((x) == '&') || ((x) == '=') || \
114         ((x) == '+') || ((x) == '$') || ((x) == ',') || ((x) == '[') || \
115         ((x) == ']'))
116 
117 /*
118  * unreserved = alphanum | mark
119  */
120 
121 #define IS_UNRESERVED(x) (IS_ALPHANUM(x) || IS_MARK(x))
122 
123 /*
124  * Skip to next pointer char, handle escaped sequences
125  */
126 
127 #define NEXT(p) ((*p == '%')? p += 3 : p++)
128 
129 /*
130  * Productions from the spec.
131  *
132  *    authority     = server | reg_name
133  *    reg_name      = 1*( unreserved | escaped | "$" | "," |
134  *                        ";" | ":" | "@" | "&" | "=" | "+" )
135  *
136  * path          = [ abs_path | opaque_part ]
137  */
138 
139 #define STRNDUP(s, n) (char *) xmlStrndup((const xmlChar *)(s), (n))
140 
141 /************************************************************************
142  *									*
143  *                         RFC 3986 parser				*
144  *									*
145  ************************************************************************/
146 
147 #define ISA_DIGIT(p) ((*(p) >= '0') && (*(p) <= '9'))
148 #define ISA_ALPHA(p) (((*(p) >= 'a') && (*(p) <= 'z')) ||		\
149                       ((*(p) >= 'A') && (*(p) <= 'Z')))
150 #define ISA_HEXDIG(p)							\
151        (ISA_DIGIT(p) || ((*(p) >= 'a') && (*(p) <= 'f')) ||		\
152         ((*(p) >= 'A') && (*(p) <= 'F')))
153 
154 /*
155  *    sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
156  *                     / "*" / "+" / "," / ";" / "="
157  */
158 #define ISA_SUB_DELIM(p)						\
159       (((*(p) == '!')) || ((*(p) == '$')) || ((*(p) == '&')) ||		\
160        ((*(p) == '(')) || ((*(p) == ')')) || ((*(p) == '*')) ||		\
161        ((*(p) == '+')) || ((*(p) == ',')) || ((*(p) == ';')) ||		\
162        ((*(p) == '=')) || ((*(p) == '\'')))
163 
164 /*
165  *    gen-delims    = ":" / "/" / "?" / "#" / "[" / "]" / "@"
166  */
167 #define ISA_GEN_DELIM(p)						\
168       (((*(p) == ':')) || ((*(p) == '/')) || ((*(p) == '?')) ||         \
169        ((*(p) == '#')) || ((*(p) == '[')) || ((*(p) == ']')) ||         \
170        ((*(p) == '@')))
171 
172 /*
173  *    reserved      = gen-delims / sub-delims
174  */
175 #define ISA_RESERVED(p) (ISA_GEN_DELIM(p) || (ISA_SUB_DELIM(p)))
176 
177 /*
178  *    unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
179  */
180 #define ISA_UNRESERVED(p)						\
181       ((ISA_ALPHA(p)) || (ISA_DIGIT(p)) || ((*(p) == '-')) ||		\
182        ((*(p) == '.')) || ((*(p) == '_')) || ((*(p) == '~')))
183 
184 /*
185  *    pct-encoded   = "%" HEXDIG HEXDIG
186  */
187 #define ISA_PCT_ENCODED(p)						\
188      ((*(p) == '%') && (ISA_HEXDIG(p + 1)) && (ISA_HEXDIG(p + 2)))
189 
190 /*
191  *    pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
192  */
193 #define ISA_PCHAR(p)							\
194      (ISA_UNRESERVED(p) || ISA_PCT_ENCODED(p) || ISA_SUB_DELIM(p) ||	\
195       ((*(p) == ':')) || ((*(p) == '@')))
196 
197 /**
198  * xmlParse3986Scheme:
199  * @uri:  pointer to an URI structure
200  * @str:  pointer to the string to analyze
201  *
202  * Parse an URI scheme
203  *
204  * ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
205  *
206  * Returns 0 or the error code
207  */
208 static int
209 xmlParse3986Scheme(xmlURIPtr uri, const char **str) {
210     const char *cur;
211 
212     if (str == NULL)
213 	return(-1);
214 
215     cur = *str;
216     if (!ISA_ALPHA(cur))
217 	return(2);
218     cur++;
219     while (ISA_ALPHA(cur) || ISA_DIGIT(cur) ||
220            (*cur == '+') || (*cur == '-') || (*cur == '.')) cur++;
221     if (uri != NULL) {
222 	if (uri->scheme != NULL) xmlFree(uri->scheme);
223 	uri->scheme = STRNDUP(*str, cur - *str);
224     }
225     *str = cur;
226     return(0);
227 }
228 
229 /**
230  * xmlParse3986Fragment:
231  * @uri:  pointer to an URI structure
232  * @str:  pointer to the string to analyze
233  *
234  * Parse the query part of an URI
235  *
236  * fragment      = *( pchar / "/" / "?" )
237  * NOTE: the strict syntax as defined by 3986 does not allow '[' and ']'
238  *       in the fragment identifier but this is used very broadly for
239  *       xpointer scheme selection, so we are allowing it here to not break
240  *       for example all the DocBook processing chains.
241  *
242  * Returns 0 or the error code
243  */
244 static int
245 xmlParse3986Fragment(xmlURIPtr uri, const char **str)
246 {
247     const char *cur;
248 
249     if (str == NULL)
250         return (-1);
251 
252     cur = *str;
253 
254     while ((ISA_PCHAR(cur)) || (*cur == '/') || (*cur == '?') ||
255            (*cur == '[') || (*cur == ']') ||
256            ((uri != NULL) && (uri->cleanup & 1) && (IS_UNWISE(cur))))
257         NEXT(cur);
258     if (uri != NULL) {
259         if (uri->fragment != NULL)
260             xmlFree(uri->fragment);
261 	if (uri->cleanup & 2)
262 	    uri->fragment = STRNDUP(*str, cur - *str);
263 	else
264 	    uri->fragment = xmlURIUnescapeString(*str, cur - *str, NULL);
265     }
266     *str = cur;
267     return (0);
268 }
269 
270 /**
271  * xmlParse3986Query:
272  * @uri:  pointer to an URI structure
273  * @str:  pointer to the string to analyze
274  *
275  * Parse the query part of an URI
276  *
277  * query = *uric
278  *
279  * Returns 0 or the error code
280  */
281 static int
282 xmlParse3986Query(xmlURIPtr uri, const char **str)
283 {
284     const char *cur;
285 
286     if (str == NULL)
287         return (-1);
288 
289     cur = *str;
290 
291     while ((ISA_PCHAR(cur)) || (*cur == '/') || (*cur == '?') ||
292            ((uri != NULL) && (uri->cleanup & 1) && (IS_UNWISE(cur))))
293         NEXT(cur);
294     if (uri != NULL) {
295         if (uri->query != NULL)
296             xmlFree(uri->query);
297 	if (uri->cleanup & 2)
298 	    uri->query = STRNDUP(*str, cur - *str);
299 	else
300 	    uri->query = xmlURIUnescapeString(*str, cur - *str, NULL);
301 
302 	/* Save the raw bytes of the query as well.
303 	 * See: http://mail.gnome.org/archives/xml/2007-April/thread.html#00114
304 	 */
305 	if (uri->query_raw != NULL)
306 	    xmlFree (uri->query_raw);
307 	uri->query_raw = STRNDUP (*str, cur - *str);
308     }
309     *str = cur;
310     return (0);
311 }
312 
313 /**
314  * xmlParse3986Port:
315  * @uri:  pointer to an URI structure
316  * @str:  the string to analyze
317  *
318  * Parse a port part and fills in the appropriate fields
319  * of the @uri structure
320  *
321  * port          = *DIGIT
322  *
323  * Returns 0 or the error code
324  */
325 static int
326 xmlParse3986Port(xmlURIPtr uri, const char **str)
327 {
328     const char *cur = *str;
329     int port = 0;
330 
331     if (ISA_DIGIT(cur)) {
332 	while (ISA_DIGIT(cur)) {
333             int digit = *cur - '0';
334 
335             if (port > INT_MAX / 10)
336                 return(1);
337             port *= 10;
338             if (port > INT_MAX - digit)
339                 return(1);
340 	    port += digit;
341 
342 	    cur++;
343 	}
344 	if (uri != NULL)
345 	    uri->port = port;
346 	*str = cur;
347 	return(0);
348     }
349     return(1);
350 }
351 
352 /**
353  * xmlParse3986Userinfo:
354  * @uri:  pointer to an URI structure
355  * @str:  the string to analyze
356  *
357  * Parse an user information part and fills in the appropriate fields
358  * of the @uri structure
359  *
360  * userinfo      = *( unreserved / pct-encoded / sub-delims / ":" )
361  *
362  * Returns 0 or the error code
363  */
364 static int
365 xmlParse3986Userinfo(xmlURIPtr uri, const char **str)
366 {
367     const char *cur;
368 
369     cur = *str;
370     while (ISA_UNRESERVED(cur) || ISA_PCT_ENCODED(cur) ||
371            ISA_SUB_DELIM(cur) || (*cur == ':'))
372 	NEXT(cur);
373     if (*cur == '@') {
374 	if (uri != NULL) {
375 	    if (uri->user != NULL) xmlFree(uri->user);
376 	    if (uri->cleanup & 2)
377 		uri->user = STRNDUP(*str, cur - *str);
378 	    else
379 		uri->user = xmlURIUnescapeString(*str, cur - *str, NULL);
380 	}
381 	*str = cur;
382 	return(0);
383     }
384     return(1);
385 }
386 
387 /**
388  * xmlParse3986DecOctet:
389  * @str:  the string to analyze
390  *
391  *    dec-octet     = DIGIT                 ; 0-9
392  *                  / %x31-39 DIGIT         ; 10-99
393  *                  / "1" 2DIGIT            ; 100-199
394  *                  / "2" %x30-34 DIGIT     ; 200-249
395  *                  / "25" %x30-35          ; 250-255
396  *
397  * Skip a dec-octet.
398  *
399  * Returns 0 if found and skipped, 1 otherwise
400  */
401 static int
402 xmlParse3986DecOctet(const char **str) {
403     const char *cur = *str;
404 
405     if (!(ISA_DIGIT(cur)))
406         return(1);
407     if (!ISA_DIGIT(cur+1))
408 	cur++;
409     else if ((*cur != '0') && (ISA_DIGIT(cur + 1)) && (!ISA_DIGIT(cur+2)))
410 	cur += 2;
411     else if ((*cur == '1') && (ISA_DIGIT(cur + 1)) && (ISA_DIGIT(cur + 2)))
412 	cur += 3;
413     else if ((*cur == '2') && (*(cur + 1) >= '0') &&
414 	     (*(cur + 1) <= '4') && (ISA_DIGIT(cur + 2)))
415 	cur += 3;
416     else if ((*cur == '2') && (*(cur + 1) == '5') &&
417 	     (*(cur + 2) >= '0') && (*(cur + 1) <= '5'))
418 	cur += 3;
419     else
420         return(1);
421     *str = cur;
422     return(0);
423 }
424 /**
425  * xmlParse3986Host:
426  * @uri:  pointer to an URI structure
427  * @str:  the string to analyze
428  *
429  * Parse an host part and fills in the appropriate fields
430  * of the @uri structure
431  *
432  * host          = IP-literal / IPv4address / reg-name
433  * IP-literal    = "[" ( IPv6address / IPvFuture  ) "]"
434  * IPv4address   = dec-octet "." dec-octet "." dec-octet "." dec-octet
435  * reg-name      = *( unreserved / pct-encoded / sub-delims )
436  *
437  * Returns 0 or the error code
438  */
439 static int
440 xmlParse3986Host(xmlURIPtr uri, const char **str)
441 {
442     const char *cur = *str;
443     const char *host;
444 
445     host = cur;
446     /*
447      * IPv6 and future addressing scheme are enclosed between brackets
448      */
449     if (*cur == '[') {
450         cur++;
451 	while ((*cur != ']') && (*cur != 0))
452 	    cur++;
453 	if (*cur != ']')
454 	    return(1);
455 	cur++;
456 	goto found;
457     }
458     /*
459      * try to parse an IPv4
460      */
461     if (ISA_DIGIT(cur)) {
462         if (xmlParse3986DecOctet(&cur) != 0)
463 	    goto not_ipv4;
464 	if (*cur != '.')
465 	    goto not_ipv4;
466 	cur++;
467         if (xmlParse3986DecOctet(&cur) != 0)
468 	    goto not_ipv4;
469 	if (*cur != '.')
470 	    goto not_ipv4;
471         if (xmlParse3986DecOctet(&cur) != 0)
472 	    goto not_ipv4;
473 	if (*cur != '.')
474 	    goto not_ipv4;
475         if (xmlParse3986DecOctet(&cur) != 0)
476 	    goto not_ipv4;
477 	goto found;
478 not_ipv4:
479         cur = *str;
480     }
481     /*
482      * then this should be a hostname which can be empty
483      */
484     while (ISA_UNRESERVED(cur) || ISA_PCT_ENCODED(cur) || ISA_SUB_DELIM(cur))
485         NEXT(cur);
486 found:
487     if (uri != NULL) {
488 	if (uri->authority != NULL) xmlFree(uri->authority);
489 	uri->authority = NULL;
490 	if (uri->server != NULL) xmlFree(uri->server);
491 	if (cur != host) {
492 	    if (uri->cleanup & 2)
493 		uri->server = STRNDUP(host, cur - host);
494 	    else
495 		uri->server = xmlURIUnescapeString(host, cur - host, NULL);
496 	} else
497 	    uri->server = NULL;
498     }
499     *str = cur;
500     return(0);
501 }
502 
503 /**
504  * xmlParse3986Authority:
505  * @uri:  pointer to an URI structure
506  * @str:  the string to analyze
507  *
508  * Parse an authority part and fills in the appropriate fields
509  * of the @uri structure
510  *
511  * authority     = [ userinfo "@" ] host [ ":" port ]
512  *
513  * Returns 0 or the error code
514  */
515 static int
516 xmlParse3986Authority(xmlURIPtr uri, const char **str)
517 {
518     const char *cur;
519     int ret;
520 
521     cur = *str;
522     /*
523      * try to parse an userinfo and check for the trailing @
524      */
525     ret = xmlParse3986Userinfo(uri, &cur);
526     if ((ret != 0) || (*cur != '@'))
527         cur = *str;
528     else
529         cur++;
530     ret = xmlParse3986Host(uri, &cur);
531     if (ret != 0) return(ret);
532     if (*cur == ':') {
533         cur++;
534         ret = xmlParse3986Port(uri, &cur);
535 	if (ret != 0) return(ret);
536     }
537     *str = cur;
538     return(0);
539 }
540 
541 /**
542  * xmlParse3986Segment:
543  * @str:  the string to analyze
544  * @forbid: an optional forbidden character
545  * @empty: allow an empty segment
546  *
547  * Parse a segment and fills in the appropriate fields
548  * of the @uri structure
549  *
550  * segment       = *pchar
551  * segment-nz    = 1*pchar
552  * segment-nz-nc = 1*( unreserved / pct-encoded / sub-delims / "@" )
553  *               ; non-zero-length segment without any colon ":"
554  *
555  * Returns 0 or the error code
556  */
557 static int
558 xmlParse3986Segment(const char **str, char forbid, int empty)
559 {
560     const char *cur;
561 
562     cur = *str;
563     if (!ISA_PCHAR(cur)) {
564         if (empty)
565 	    return(0);
566 	return(1);
567     }
568     while (ISA_PCHAR(cur) && (*cur != forbid))
569         NEXT(cur);
570     *str = cur;
571     return (0);
572 }
573 
574 /**
575  * xmlParse3986PathAbEmpty:
576  * @uri:  pointer to an URI structure
577  * @str:  the string to analyze
578  *
579  * Parse an path absolute or empty and fills in the appropriate fields
580  * of the @uri structure
581  *
582  * path-abempty  = *( "/" segment )
583  *
584  * Returns 0 or the error code
585  */
586 static int
587 xmlParse3986PathAbEmpty(xmlURIPtr uri, const char **str)
588 {
589     const char *cur;
590     int ret;
591 
592     cur = *str;
593 
594     while (*cur == '/') {
595         cur++;
596 	ret = xmlParse3986Segment(&cur, 0, 1);
597 	if (ret != 0) return(ret);
598     }
599     if (uri != NULL) {
600 	if (uri->path != NULL) xmlFree(uri->path);
601         if (*str != cur) {
602             if (uri->cleanup & 2)
603                 uri->path = STRNDUP(*str, cur - *str);
604             else
605                 uri->path = xmlURIUnescapeString(*str, cur - *str, NULL);
606         } else {
607             uri->path = NULL;
608         }
609     }
610     *str = cur;
611     return (0);
612 }
613 
614 /**
615  * xmlParse3986PathAbsolute:
616  * @uri:  pointer to an URI structure
617  * @str:  the string to analyze
618  *
619  * Parse an path absolute and fills in the appropriate fields
620  * of the @uri structure
621  *
622  * path-absolute = "/" [ segment-nz *( "/" segment ) ]
623  *
624  * Returns 0 or the error code
625  */
626 static int
627 xmlParse3986PathAbsolute(xmlURIPtr uri, const char **str)
628 {
629     const char *cur;
630     int ret;
631 
632     cur = *str;
633 
634     if (*cur != '/')
635         return(1);
636     cur++;
637     ret = xmlParse3986Segment(&cur, 0, 0);
638     if (ret == 0) {
639 	while (*cur == '/') {
640 	    cur++;
641 	    ret = xmlParse3986Segment(&cur, 0, 1);
642 	    if (ret != 0) return(ret);
643 	}
644     }
645     if (uri != NULL) {
646 	if (uri->path != NULL) xmlFree(uri->path);
647         if (cur != *str) {
648             if (uri->cleanup & 2)
649                 uri->path = STRNDUP(*str, cur - *str);
650             else
651                 uri->path = xmlURIUnescapeString(*str, cur - *str, NULL);
652         } else {
653             uri->path = NULL;
654         }
655     }
656     *str = cur;
657     return (0);
658 }
659 
660 /**
661  * xmlParse3986PathRootless:
662  * @uri:  pointer to an URI structure
663  * @str:  the string to analyze
664  *
665  * Parse an path without root and fills in the appropriate fields
666  * of the @uri structure
667  *
668  * path-rootless = segment-nz *( "/" segment )
669  *
670  * Returns 0 or the error code
671  */
672 static int
673 xmlParse3986PathRootless(xmlURIPtr uri, const char **str)
674 {
675     const char *cur;
676     int ret;
677 
678     cur = *str;
679 
680     ret = xmlParse3986Segment(&cur, 0, 0);
681     if (ret != 0) return(ret);
682     while (*cur == '/') {
683         cur++;
684 	ret = xmlParse3986Segment(&cur, 0, 1);
685 	if (ret != 0) return(ret);
686     }
687     if (uri != NULL) {
688 	if (uri->path != NULL) xmlFree(uri->path);
689         if (cur != *str) {
690             if (uri->cleanup & 2)
691                 uri->path = STRNDUP(*str, cur - *str);
692             else
693                 uri->path = xmlURIUnescapeString(*str, cur - *str, NULL);
694         } else {
695             uri->path = NULL;
696         }
697     }
698     *str = cur;
699     return (0);
700 }
701 
702 /**
703  * xmlParse3986PathNoScheme:
704  * @uri:  pointer to an URI structure
705  * @str:  the string to analyze
706  *
707  * Parse an path which is not a scheme and fills in the appropriate fields
708  * of the @uri structure
709  *
710  * path-noscheme = segment-nz-nc *( "/" segment )
711  *
712  * Returns 0 or the error code
713  */
714 static int
715 xmlParse3986PathNoScheme(xmlURIPtr uri, const char **str)
716 {
717     const char *cur;
718     int ret;
719 
720     cur = *str;
721 
722     ret = xmlParse3986Segment(&cur, ':', 0);
723     if (ret != 0) return(ret);
724     while (*cur == '/') {
725         cur++;
726 	ret = xmlParse3986Segment(&cur, 0, 1);
727 	if (ret != 0) return(ret);
728     }
729     if (uri != NULL) {
730 	if (uri->path != NULL) xmlFree(uri->path);
731         if (cur != *str) {
732             if (uri->cleanup & 2)
733                 uri->path = STRNDUP(*str, cur - *str);
734             else
735                 uri->path = xmlURIUnescapeString(*str, cur - *str, NULL);
736         } else {
737             uri->path = NULL;
738         }
739     }
740     *str = cur;
741     return (0);
742 }
743 
744 /**
745  * xmlParse3986HierPart:
746  * @uri:  pointer to an URI structure
747  * @str:  the string to analyze
748  *
749  * Parse an hierarchical part and fills in the appropriate fields
750  * of the @uri structure
751  *
752  * hier-part     = "//" authority path-abempty
753  *                / path-absolute
754  *                / path-rootless
755  *                / path-empty
756  *
757  * Returns 0 or the error code
758  */
759 static int
760 xmlParse3986HierPart(xmlURIPtr uri, const char **str)
761 {
762     const char *cur;
763     int ret;
764 
765     cur = *str;
766 
767     if ((*cur == '/') && (*(cur + 1) == '/')) {
768         cur += 2;
769 	ret = xmlParse3986Authority(uri, &cur);
770 	if (ret != 0) return(ret);
771 	if (uri->server == NULL)
772 	    uri->port = -1;
773 	ret = xmlParse3986PathAbEmpty(uri, &cur);
774 	if (ret != 0) return(ret);
775 	*str = cur;
776 	return(0);
777     } else if (*cur == '/') {
778         ret = xmlParse3986PathAbsolute(uri, &cur);
779 	if (ret != 0) return(ret);
780     } else if (ISA_PCHAR(cur)) {
781         ret = xmlParse3986PathRootless(uri, &cur);
782 	if (ret != 0) return(ret);
783     } else {
784 	/* path-empty is effectively empty */
785 	if (uri != NULL) {
786 	    if (uri->path != NULL) xmlFree(uri->path);
787 	    uri->path = NULL;
788 	}
789     }
790     *str = cur;
791     return (0);
792 }
793 
794 /**
795  * xmlParse3986RelativeRef:
796  * @uri:  pointer to an URI structure
797  * @str:  the string to analyze
798  *
799  * Parse an URI string and fills in the appropriate fields
800  * of the @uri structure
801  *
802  * relative-ref  = relative-part [ "?" query ] [ "#" fragment ]
803  * relative-part = "//" authority path-abempty
804  *               / path-absolute
805  *               / path-noscheme
806  *               / path-empty
807  *
808  * Returns 0 or the error code
809  */
810 static int
811 xmlParse3986RelativeRef(xmlURIPtr uri, const char *str) {
812     int ret;
813 
814     if ((*str == '/') && (*(str + 1) == '/')) {
815         str += 2;
816 	ret = xmlParse3986Authority(uri, &str);
817 	if (ret != 0) return(ret);
818 	ret = xmlParse3986PathAbEmpty(uri, &str);
819 	if (ret != 0) return(ret);
820     } else if (*str == '/') {
821 	ret = xmlParse3986PathAbsolute(uri, &str);
822 	if (ret != 0) return(ret);
823     } else if (ISA_PCHAR(str)) {
824         ret = xmlParse3986PathNoScheme(uri, &str);
825 	if (ret != 0) return(ret);
826     } else {
827 	/* path-empty is effectively empty */
828 	if (uri != NULL) {
829 	    if (uri->path != NULL) xmlFree(uri->path);
830 	    uri->path = NULL;
831 	}
832     }
833 
834     if (*str == '?') {
835 	str++;
836 	ret = xmlParse3986Query(uri, &str);
837 	if (ret != 0) return(ret);
838     }
839     if (*str == '#') {
840 	str++;
841 	ret = xmlParse3986Fragment(uri, &str);
842 	if (ret != 0) return(ret);
843     }
844     if (*str != 0) {
845 	xmlCleanURI(uri);
846 	return(1);
847     }
848     return(0);
849 }
850 
851 
852 /**
853  * xmlParse3986URI:
854  * @uri:  pointer to an URI structure
855  * @str:  the string to analyze
856  *
857  * Parse an URI string and fills in the appropriate fields
858  * of the @uri structure
859  *
860  * scheme ":" hier-part [ "?" query ] [ "#" fragment ]
861  *
862  * Returns 0 or the error code
863  */
864 static int
865 xmlParse3986URI(xmlURIPtr uri, const char *str) {
866     int ret;
867 
868     ret = xmlParse3986Scheme(uri, &str);
869     if (ret != 0) return(ret);
870     if (*str != ':') {
871 	return(1);
872     }
873     str++;
874     ret = xmlParse3986HierPart(uri, &str);
875     if (ret != 0) return(ret);
876     if (*str == '?') {
877 	str++;
878 	ret = xmlParse3986Query(uri, &str);
879 	if (ret != 0) return(ret);
880     }
881     if (*str == '#') {
882 	str++;
883 	ret = xmlParse3986Fragment(uri, &str);
884 	if (ret != 0) return(ret);
885     }
886     if (*str != 0) {
887 	xmlCleanURI(uri);
888 	return(1);
889     }
890     return(0);
891 }
892 
893 /**
894  * xmlParse3986URIReference:
895  * @uri:  pointer to an URI structure
896  * @str:  the string to analyze
897  *
898  * Parse an URI reference string and fills in the appropriate fields
899  * of the @uri structure
900  *
901  * URI-reference = URI / relative-ref
902  *
903  * Returns 0 or the error code
904  */
905 static int
906 xmlParse3986URIReference(xmlURIPtr uri, const char *str) {
907     int ret;
908 
909     if (str == NULL)
910 	return(-1);
911     xmlCleanURI(uri);
912 
913     /*
914      * Try first to parse absolute refs, then fallback to relative if
915      * it fails.
916      */
917     ret = xmlParse3986URI(uri, str);
918     if (ret != 0) {
919 	xmlCleanURI(uri);
920         ret = xmlParse3986RelativeRef(uri, str);
921 	if (ret != 0) {
922 	    xmlCleanURI(uri);
923 	    return(ret);
924 	}
925     }
926     return(0);
927 }
928 
929 /**
930  * xmlParseURI:
931  * @str:  the URI string to analyze
932  *
933  * Parse an URI based on RFC 3986
934  *
935  * URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
936  *
937  * Returns a newly built xmlURIPtr or NULL in case of error
938  */
939 xmlURIPtr
940 xmlParseURI(const char *str) {
941     xmlURIPtr uri;
942     int ret;
943 
944     if (str == NULL)
945 	return(NULL);
946     uri = xmlCreateURI();
947     if (uri != NULL) {
948 	ret = xmlParse3986URIReference(uri, str);
949         if (ret) {
950 	    xmlFreeURI(uri);
951 	    return(NULL);
952 	}
953     }
954     return(uri);
955 }
956 
957 /**
958  * xmlParseURIReference:
959  * @uri:  pointer to an URI structure
960  * @str:  the string to analyze
961  *
962  * Parse an URI reference string based on RFC 3986 and fills in the
963  * appropriate fields of the @uri structure
964  *
965  * URI-reference = URI / relative-ref
966  *
967  * Returns 0 or the error code
968  */
969 int
970 xmlParseURIReference(xmlURIPtr uri, const char *str) {
971     return(xmlParse3986URIReference(uri, str));
972 }
973 
974 /**
975  * xmlParseURIRaw:
976  * @str:  the URI string to analyze
977  * @raw:  if 1 unescaping of URI pieces are disabled
978  *
979  * Parse an URI but allows to keep intact the original fragments.
980  *
981  * URI-reference = URI / relative-ref
982  *
983  * Returns a newly built xmlURIPtr or NULL in case of error
984  */
985 xmlURIPtr
986 xmlParseURIRaw(const char *str, int raw) {
987     xmlURIPtr uri;
988     int ret;
989 
990     if (str == NULL)
991 	return(NULL);
992     uri = xmlCreateURI();
993     if (uri != NULL) {
994         if (raw) {
995 	    uri->cleanup |= 2;
996 	}
997 	ret = xmlParseURIReference(uri, str);
998         if (ret) {
999 	    xmlFreeURI(uri);
1000 	    return(NULL);
1001 	}
1002     }
1003     return(uri);
1004 }
1005 
1006 /************************************************************************
1007  *									*
1008  *			Generic URI structure functions			*
1009  *									*
1010  ************************************************************************/
1011 
1012 /**
1013  * xmlCreateURI:
1014  *
1015  * Simply creates an empty xmlURI
1016  *
1017  * Returns the new structure or NULL in case of error
1018  */
1019 xmlURIPtr
1020 xmlCreateURI(void) {
1021     xmlURIPtr ret;
1022 
1023     ret = (xmlURIPtr) xmlMalloc(sizeof(xmlURI));
1024     if (ret == NULL) {
1025         xmlURIErrMemory("creating URI structure\n");
1026 	return(NULL);
1027     }
1028     memset(ret, 0, sizeof(xmlURI));
1029     return(ret);
1030 }
1031 
1032 /**
1033  * xmlSaveUriRealloc:
1034  *
1035  * Function to handle properly a reallocation when saving an URI
1036  * Also imposes some limit on the length of an URI string output
1037  */
1038 static xmlChar *
1039 xmlSaveUriRealloc(xmlChar *ret, int *max) {
1040     xmlChar *temp;
1041     int tmp;
1042 
1043     if (*max > MAX_URI_LENGTH) {
1044         xmlURIErrMemory("reaching arbitrary MAX_URI_LENGTH limit\n");
1045         return(NULL);
1046     }
1047     tmp = *max * 2;
1048     temp = (xmlChar *) xmlRealloc(ret, (tmp + 1));
1049     if (temp == NULL) {
1050         xmlURIErrMemory("saving URI\n");
1051         return(NULL);
1052     }
1053     *max = tmp;
1054     return(temp);
1055 }
1056 
1057 /**
1058  * xmlSaveUri:
1059  * @uri:  pointer to an xmlURI
1060  *
1061  * Save the URI as an escaped string
1062  *
1063  * Returns a new string (to be deallocated by caller)
1064  */
1065 xmlChar *
1066 xmlSaveUri(xmlURIPtr uri) {
1067     xmlChar *ret = NULL;
1068     xmlChar *temp;
1069     const char *p;
1070     int len;
1071     int max;
1072 
1073     if (uri == NULL) return(NULL);
1074 
1075 
1076     max = 80;
1077     ret = (xmlChar *) xmlMallocAtomic((max + 1) * sizeof(xmlChar));
1078     if (ret == NULL) {
1079         xmlURIErrMemory("saving URI\n");
1080 	return(NULL);
1081     }
1082     len = 0;
1083 
1084     if (uri->scheme != NULL) {
1085 	p = uri->scheme;
1086 	while (*p != 0) {
1087 	    if (len >= max) {
1088                 temp = xmlSaveUriRealloc(ret, &max);
1089                 if (temp == NULL) goto mem_error;
1090 		ret = temp;
1091 	    }
1092 	    ret[len++] = *p++;
1093 	}
1094 	if (len >= max) {
1095             temp = xmlSaveUriRealloc(ret, &max);
1096             if (temp == NULL) goto mem_error;
1097             ret = temp;
1098 	}
1099 	ret[len++] = ':';
1100     }
1101     if (uri->opaque != NULL) {
1102 	p = uri->opaque;
1103 	while (*p != 0) {
1104 	    if (len + 3 >= max) {
1105                 temp = xmlSaveUriRealloc(ret, &max);
1106                 if (temp == NULL) goto mem_error;
1107                 ret = temp;
1108 	    }
1109 	    if (IS_RESERVED(*(p)) || IS_UNRESERVED(*(p)))
1110 		ret[len++] = *p++;
1111 	    else {
1112 		int val = *(unsigned char *)p++;
1113 		int hi = val / 0x10, lo = val % 0x10;
1114 		ret[len++] = '%';
1115 		ret[len++] = hi + (hi > 9? 'A'-10 : '0');
1116 		ret[len++] = lo + (lo > 9? 'A'-10 : '0');
1117 	    }
1118 	}
1119     } else {
1120 	if ((uri->server != NULL) || (uri->port == -1)) {
1121 	    if (len + 3 >= max) {
1122                 temp = xmlSaveUriRealloc(ret, &max);
1123                 if (temp == NULL) goto mem_error;
1124                 ret = temp;
1125 	    }
1126 	    ret[len++] = '/';
1127 	    ret[len++] = '/';
1128 	    if (uri->user != NULL) {
1129 		p = uri->user;
1130 		while (*p != 0) {
1131 		    if (len + 3 >= max) {
1132                         temp = xmlSaveUriRealloc(ret, &max);
1133                         if (temp == NULL) goto mem_error;
1134                         ret = temp;
1135 		    }
1136 		    if ((IS_UNRESERVED(*(p))) ||
1137 			((*(p) == ';')) || ((*(p) == ':')) ||
1138 			((*(p) == '&')) || ((*(p) == '=')) ||
1139 			((*(p) == '+')) || ((*(p) == '$')) ||
1140 			((*(p) == ',')))
1141 			ret[len++] = *p++;
1142 		    else {
1143 			int val = *(unsigned char *)p++;
1144 			int hi = val / 0x10, lo = val % 0x10;
1145 			ret[len++] = '%';
1146 			ret[len++] = hi + (hi > 9? 'A'-10 : '0');
1147 			ret[len++] = lo + (lo > 9? 'A'-10 : '0');
1148 		    }
1149 		}
1150 		if (len + 3 >= max) {
1151                     temp = xmlSaveUriRealloc(ret, &max);
1152                     if (temp == NULL) goto mem_error;
1153                     ret = temp;
1154 		}
1155 		ret[len++] = '@';
1156 	    }
1157 	    if (uri->server != NULL) {
1158 		p = uri->server;
1159 		while (*p != 0) {
1160 		    if (len >= max) {
1161 			temp = xmlSaveUriRealloc(ret, &max);
1162 			if (temp == NULL) goto mem_error;
1163 			ret = temp;
1164 		    }
1165 		    ret[len++] = *p++;
1166 		}
1167 		if (uri->port > 0) {
1168 		    if (len + 10 >= max) {
1169 			temp = xmlSaveUriRealloc(ret, &max);
1170 			if (temp == NULL) goto mem_error;
1171 			ret = temp;
1172 		    }
1173 		    len += snprintf((char *) &ret[len], max - len, ":%d", uri->port);
1174 		}
1175 	    }
1176 	} else if (uri->authority != NULL) {
1177 	    if (len + 3 >= max) {
1178                 temp = xmlSaveUriRealloc(ret, &max);
1179                 if (temp == NULL) goto mem_error;
1180                 ret = temp;
1181 	    }
1182 	    ret[len++] = '/';
1183 	    ret[len++] = '/';
1184 	    p = uri->authority;
1185 	    while (*p != 0) {
1186 		if (len + 3 >= max) {
1187                     temp = xmlSaveUriRealloc(ret, &max);
1188                     if (temp == NULL) goto mem_error;
1189                     ret = temp;
1190 		}
1191 		if ((IS_UNRESERVED(*(p))) ||
1192                     ((*(p) == '$')) || ((*(p) == ',')) || ((*(p) == ';')) ||
1193                     ((*(p) == ':')) || ((*(p) == '@')) || ((*(p) == '&')) ||
1194                     ((*(p) == '=')) || ((*(p) == '+')))
1195 		    ret[len++] = *p++;
1196 		else {
1197 		    int val = *(unsigned char *)p++;
1198 		    int hi = val / 0x10, lo = val % 0x10;
1199 		    ret[len++] = '%';
1200 		    ret[len++] = hi + (hi > 9? 'A'-10 : '0');
1201 		    ret[len++] = lo + (lo > 9? 'A'-10 : '0');
1202 		}
1203 	    }
1204 	} else if (uri->scheme != NULL) {
1205 	    if (len + 3 >= max) {
1206                 temp = xmlSaveUriRealloc(ret, &max);
1207                 if (temp == NULL) goto mem_error;
1208                 ret = temp;
1209 	    }
1210 	}
1211 	if (uri->path != NULL) {
1212 	    p = uri->path;
1213 	    /*
1214 	     * the colon in file:///d: should not be escaped or
1215 	     * Windows accesses fail later.
1216 	     */
1217 	    if ((uri->scheme != NULL) &&
1218 		(p[0] == '/') &&
1219 		(((p[1] >= 'a') && (p[1] <= 'z')) ||
1220 		 ((p[1] >= 'A') && (p[1] <= 'Z'))) &&
1221 		(p[2] == ':') &&
1222 	        (xmlStrEqual(BAD_CAST uri->scheme, BAD_CAST "file"))) {
1223 		if (len + 3 >= max) {
1224                     temp = xmlSaveUriRealloc(ret, &max);
1225                     if (temp == NULL) goto mem_error;
1226                     ret = temp;
1227 		}
1228 		ret[len++] = *p++;
1229 		ret[len++] = *p++;
1230 		ret[len++] = *p++;
1231 	    }
1232 	    while (*p != 0) {
1233 		if (len + 3 >= max) {
1234                     temp = xmlSaveUriRealloc(ret, &max);
1235                     if (temp == NULL) goto mem_error;
1236                     ret = temp;
1237 		}
1238 		if ((IS_UNRESERVED(*(p))) || ((*(p) == '/')) ||
1239                     ((*(p) == ';')) || ((*(p) == '@')) || ((*(p) == '&')) ||
1240 	            ((*(p) == '=')) || ((*(p) == '+')) || ((*(p) == '$')) ||
1241 	            ((*(p) == ',')))
1242 		    ret[len++] = *p++;
1243 		else {
1244 		    int val = *(unsigned char *)p++;
1245 		    int hi = val / 0x10, lo = val % 0x10;
1246 		    ret[len++] = '%';
1247 		    ret[len++] = hi + (hi > 9? 'A'-10 : '0');
1248 		    ret[len++] = lo + (lo > 9? 'A'-10 : '0');
1249 		}
1250 	    }
1251 	}
1252 	if (uri->query_raw != NULL) {
1253 	    if (len + 1 >= max) {
1254                 temp = xmlSaveUriRealloc(ret, &max);
1255                 if (temp == NULL) goto mem_error;
1256                 ret = temp;
1257 	    }
1258 	    ret[len++] = '?';
1259 	    p = uri->query_raw;
1260 	    while (*p != 0) {
1261 		if (len + 1 >= max) {
1262                     temp = xmlSaveUriRealloc(ret, &max);
1263                     if (temp == NULL) goto mem_error;
1264                     ret = temp;
1265 		}
1266 		ret[len++] = *p++;
1267 	    }
1268 	} else if (uri->query != NULL) {
1269 	    if (len + 3 >= max) {
1270                 temp = xmlSaveUriRealloc(ret, &max);
1271                 if (temp == NULL) goto mem_error;
1272                 ret = temp;
1273 	    }
1274 	    ret[len++] = '?';
1275 	    p = uri->query;
1276 	    while (*p != 0) {
1277 		if (len + 3 >= max) {
1278                     temp = xmlSaveUriRealloc(ret, &max);
1279                     if (temp == NULL) goto mem_error;
1280                     ret = temp;
1281 		}
1282 		if ((IS_UNRESERVED(*(p))) || (IS_RESERVED(*(p))))
1283 		    ret[len++] = *p++;
1284 		else {
1285 		    int val = *(unsigned char *)p++;
1286 		    int hi = val / 0x10, lo = val % 0x10;
1287 		    ret[len++] = '%';
1288 		    ret[len++] = hi + (hi > 9? 'A'-10 : '0');
1289 		    ret[len++] = lo + (lo > 9? 'A'-10 : '0');
1290 		}
1291 	    }
1292 	}
1293     }
1294     if (uri->fragment != NULL) {
1295 	if (len + 3 >= max) {
1296             temp = xmlSaveUriRealloc(ret, &max);
1297             if (temp == NULL) goto mem_error;
1298             ret = temp;
1299 	}
1300 	ret[len++] = '#';
1301 	p = uri->fragment;
1302 	while (*p != 0) {
1303 	    if (len + 3 >= max) {
1304                 temp = xmlSaveUriRealloc(ret, &max);
1305                 if (temp == NULL) goto mem_error;
1306                 ret = temp;
1307 	    }
1308 	    if ((IS_UNRESERVED(*(p))) || (IS_RESERVED(*(p))))
1309 		ret[len++] = *p++;
1310 	    else {
1311 		int val = *(unsigned char *)p++;
1312 		int hi = val / 0x10, lo = val % 0x10;
1313 		ret[len++] = '%';
1314 		ret[len++] = hi + (hi > 9? 'A'-10 : '0');
1315 		ret[len++] = lo + (lo > 9? 'A'-10 : '0');
1316 	    }
1317 	}
1318     }
1319     if (len >= max) {
1320         temp = xmlSaveUriRealloc(ret, &max);
1321         if (temp == NULL) goto mem_error;
1322         ret = temp;
1323     }
1324     ret[len] = 0;
1325     return(ret);
1326 
1327 mem_error:
1328     xmlFree(ret);
1329     return(NULL);
1330 }
1331 
1332 /**
1333  * xmlPrintURI:
1334  * @stream:  a FILE* for the output
1335  * @uri:  pointer to an xmlURI
1336  *
1337  * Prints the URI in the stream @stream.
1338  */
1339 void
1340 xmlPrintURI(FILE *stream, xmlURIPtr uri) {
1341     xmlChar *out;
1342 
1343     out = xmlSaveUri(uri);
1344     if (out != NULL) {
1345 	fprintf(stream, "%s", (char *) out);
1346 	xmlFree(out);
1347     }
1348 }
1349 
1350 /**
1351  * xmlCleanURI:
1352  * @uri:  pointer to an xmlURI
1353  *
1354  * Make sure the xmlURI struct is free of content
1355  */
1356 static void
1357 xmlCleanURI(xmlURIPtr uri) {
1358     if (uri == NULL) return;
1359 
1360     if (uri->scheme != NULL) xmlFree(uri->scheme);
1361     uri->scheme = NULL;
1362     if (uri->server != NULL) xmlFree(uri->server);
1363     uri->server = NULL;
1364     if (uri->user != NULL) xmlFree(uri->user);
1365     uri->user = NULL;
1366     if (uri->path != NULL) xmlFree(uri->path);
1367     uri->path = NULL;
1368     if (uri->fragment != NULL) xmlFree(uri->fragment);
1369     uri->fragment = NULL;
1370     if (uri->opaque != NULL) xmlFree(uri->opaque);
1371     uri->opaque = NULL;
1372     if (uri->authority != NULL) xmlFree(uri->authority);
1373     uri->authority = NULL;
1374     if (uri->query != NULL) xmlFree(uri->query);
1375     uri->query = NULL;
1376     if (uri->query_raw != NULL) xmlFree(uri->query_raw);
1377     uri->query_raw = NULL;
1378 }
1379 
1380 /**
1381  * xmlFreeURI:
1382  * @uri:  pointer to an xmlURI
1383  *
1384  * Free up the xmlURI struct
1385  */
1386 void
1387 xmlFreeURI(xmlURIPtr uri) {
1388     if (uri == NULL) return;
1389 
1390     if (uri->scheme != NULL) xmlFree(uri->scheme);
1391     if (uri->server != NULL) xmlFree(uri->server);
1392     if (uri->user != NULL) xmlFree(uri->user);
1393     if (uri->path != NULL) xmlFree(uri->path);
1394     if (uri->fragment != NULL) xmlFree(uri->fragment);
1395     if (uri->opaque != NULL) xmlFree(uri->opaque);
1396     if (uri->authority != NULL) xmlFree(uri->authority);
1397     if (uri->query != NULL) xmlFree(uri->query);
1398     if (uri->query_raw != NULL) xmlFree(uri->query_raw);
1399     xmlFree(uri);
1400 }
1401 
1402 /************************************************************************
1403  *									*
1404  *			Helper functions				*
1405  *									*
1406  ************************************************************************/
1407 
1408 /**
1409  * xmlNormalizeURIPath:
1410  * @path:  pointer to the path string
1411  *
1412  * Applies the 5 normalization steps to a path string--that is, RFC 2396
1413  * Section 5.2, steps 6.c through 6.g.
1414  *
1415  * Normalization occurs directly on the string, no new allocation is done
1416  *
1417  * Returns 0 or an error code
1418  */
1419 int
1420 xmlNormalizeURIPath(char *path) {
1421     char *cur, *out;
1422 
1423     if (path == NULL)
1424 	return(-1);
1425 
1426     /* Skip all initial "/" chars.  We want to get to the beginning of the
1427      * first non-empty segment.
1428      */
1429     cur = path;
1430     while (cur[0] == '/')
1431       ++cur;
1432     if (cur[0] == '\0')
1433       return(0);
1434 
1435     /* Keep everything we've seen so far.  */
1436     out = cur;
1437 
1438     /*
1439      * Analyze each segment in sequence for cases (c) and (d).
1440      */
1441     while (cur[0] != '\0') {
1442 	/*
1443 	 * c) All occurrences of "./", where "." is a complete path segment,
1444 	 *    are removed from the buffer string.
1445 	 */
1446 	if ((cur[0] == '.') && (cur[1] == '/')) {
1447 	    cur += 2;
1448 	    /* '//' normalization should be done at this point too */
1449 	    while (cur[0] == '/')
1450 		cur++;
1451 	    continue;
1452 	}
1453 
1454 	/*
1455 	 * d) If the buffer string ends with "." as a complete path segment,
1456 	 *    that "." is removed.
1457 	 */
1458 	if ((cur[0] == '.') && (cur[1] == '\0'))
1459 	    break;
1460 
1461 	/* Otherwise keep the segment.  */
1462 	while (cur[0] != '/') {
1463             if (cur[0] == '\0')
1464               goto done_cd;
1465 	    (out++)[0] = (cur++)[0];
1466 	}
1467 	/* normalize // */
1468 	while ((cur[0] == '/') && (cur[1] == '/'))
1469 	    cur++;
1470 
1471         (out++)[0] = (cur++)[0];
1472     }
1473  done_cd:
1474     out[0] = '\0';
1475 
1476     /* Reset to the beginning of the first segment for the next sequence.  */
1477     cur = path;
1478     while (cur[0] == '/')
1479       ++cur;
1480     if (cur[0] == '\0')
1481 	return(0);
1482 
1483     /*
1484      * Analyze each segment in sequence for cases (e) and (f).
1485      *
1486      * e) All occurrences of "<segment>/../", where <segment> is a
1487      *    complete path segment not equal to "..", are removed from the
1488      *    buffer string.  Removal of these path segments is performed
1489      *    iteratively, removing the leftmost matching pattern on each
1490      *    iteration, until no matching pattern remains.
1491      *
1492      * f) If the buffer string ends with "<segment>/..", where <segment>
1493      *    is a complete path segment not equal to "..", that
1494      *    "<segment>/.." is removed.
1495      *
1496      * To satisfy the "iterative" clause in (e), we need to collapse the
1497      * string every time we find something that needs to be removed.  Thus,
1498      * we don't need to keep two pointers into the string: we only need a
1499      * "current position" pointer.
1500      */
1501     while (1) {
1502         char *segp, *tmp;
1503 
1504         /* At the beginning of each iteration of this loop, "cur" points to
1505          * the first character of the segment we want to examine.
1506          */
1507 
1508         /* Find the end of the current segment.  */
1509         segp = cur;
1510         while ((segp[0] != '/') && (segp[0] != '\0'))
1511           ++segp;
1512 
1513         /* If this is the last segment, we're done (we need at least two
1514          * segments to meet the criteria for the (e) and (f) cases).
1515          */
1516         if (segp[0] == '\0')
1517           break;
1518 
1519         /* If the first segment is "..", or if the next segment _isn't_ "..",
1520          * keep this segment and try the next one.
1521          */
1522         ++segp;
1523         if (((cur[0] == '.') && (cur[1] == '.') && (segp == cur+3))
1524             || ((segp[0] != '.') || (segp[1] != '.')
1525                 || ((segp[2] != '/') && (segp[2] != '\0')))) {
1526           cur = segp;
1527           continue;
1528         }
1529 
1530         /* If we get here, remove this segment and the next one and back up
1531          * to the previous segment (if there is one), to implement the
1532          * "iteratively" clause.  It's pretty much impossible to back up
1533          * while maintaining two pointers into the buffer, so just compact
1534          * the whole buffer now.
1535          */
1536 
1537         /* If this is the end of the buffer, we're done.  */
1538         if (segp[2] == '\0') {
1539           cur[0] = '\0';
1540           break;
1541         }
1542         /* Valgrind complained, strcpy(cur, segp + 3); */
1543         /* string will overlap, do not use strcpy */
1544         tmp = cur;
1545         segp += 3;
1546         while ((*tmp++ = *segp++) != 0)
1547           ;
1548 
1549         /* If there are no previous segments, then keep going from here.  */
1550         segp = cur;
1551         while ((segp > path) && ((--segp)[0] == '/'))
1552           ;
1553         if (segp == path)
1554           continue;
1555 
1556         /* "segp" is pointing to the end of a previous segment; find it's
1557          * start.  We need to back up to the previous segment and start
1558          * over with that to handle things like "foo/bar/../..".  If we
1559          * don't do this, then on the first pass we'll remove the "bar/..",
1560          * but be pointing at the second ".." so we won't realize we can also
1561          * remove the "foo/..".
1562          */
1563         cur = segp;
1564         while ((cur > path) && (cur[-1] != '/'))
1565           --cur;
1566     }
1567     out[0] = '\0';
1568 
1569     /*
1570      * g) If the resulting buffer string still begins with one or more
1571      *    complete path segments of "..", then the reference is
1572      *    considered to be in error. Implementations may handle this
1573      *    error by retaining these components in the resolved path (i.e.,
1574      *    treating them as part of the final URI), by removing them from
1575      *    the resolved path (i.e., discarding relative levels above the
1576      *    root), or by avoiding traversal of the reference.
1577      *
1578      * We discard them from the final path.
1579      */
1580     if (path[0] == '/') {
1581       cur = path;
1582       while ((cur[0] == '/') && (cur[1] == '.') && (cur[2] == '.')
1583              && ((cur[3] == '/') || (cur[3] == '\0')))
1584 	cur += 3;
1585 
1586       if (cur != path) {
1587 	out = path;
1588 	while (cur[0] != '\0')
1589           (out++)[0] = (cur++)[0];
1590 	out[0] = 0;
1591       }
1592     }
1593 
1594     return(0);
1595 }
1596 
1597 static int is_hex(char c) {
1598     if (((c >= '0') && (c <= '9')) ||
1599         ((c >= 'a') && (c <= 'f')) ||
1600         ((c >= 'A') && (c <= 'F')))
1601 	return(1);
1602     return(0);
1603 }
1604 
1605 /**
1606  * xmlURIUnescapeString:
1607  * @str:  the string to unescape
1608  * @len:   the length in bytes to unescape (or <= 0 to indicate full string)
1609  * @target:  optional destination buffer
1610  *
1611  * Unescaping routine, but does not check that the string is an URI. The
1612  * output is a direct unsigned char translation of %XX values (no encoding)
1613  * Note that the length of the result can only be smaller or same size as
1614  * the input string.
1615  *
1616  * Returns a copy of the string, but unescaped, will return NULL only in case
1617  * of error
1618  */
1619 char *
1620 xmlURIUnescapeString(const char *str, int len, char *target) {
1621     char *ret, *out;
1622     const char *in;
1623 
1624     if (str == NULL)
1625 	return(NULL);
1626     if (len <= 0) len = strlen(str);
1627     if (len < 0) return(NULL);
1628 
1629     if (target == NULL) {
1630 	ret = (char *) xmlMallocAtomic(len + 1);
1631 	if (ret == NULL) {
1632             xmlURIErrMemory("unescaping URI value\n");
1633 	    return(NULL);
1634 	}
1635     } else
1636 	ret = target;
1637     in = str;
1638     out = ret;
1639     while(len > 0) {
1640 	if ((len > 2) && (*in == '%') && (is_hex(in[1])) && (is_hex(in[2]))) {
1641 	    in++;
1642 	    if ((*in >= '0') && (*in <= '9'))
1643 	        *out = (*in - '0');
1644 	    else if ((*in >= 'a') && (*in <= 'f'))
1645 	        *out = (*in - 'a') + 10;
1646 	    else if ((*in >= 'A') && (*in <= 'F'))
1647 	        *out = (*in - 'A') + 10;
1648 	    in++;
1649 	    if ((*in >= '0') && (*in <= '9'))
1650 	        *out = *out * 16 + (*in - '0');
1651 	    else if ((*in >= 'a') && (*in <= 'f'))
1652 	        *out = *out * 16 + (*in - 'a') + 10;
1653 	    else if ((*in >= 'A') && (*in <= 'F'))
1654 	        *out = *out * 16 + (*in - 'A') + 10;
1655 	    in++;
1656 	    len -= 3;
1657 	    out++;
1658 	} else {
1659 	    *out++ = *in++;
1660 	    len--;
1661 	}
1662     }
1663     *out = 0;
1664     return(ret);
1665 }
1666 
1667 /**
1668  * xmlURIEscapeStr:
1669  * @str:  string to escape
1670  * @list: exception list string of chars not to escape
1671  *
1672  * This routine escapes a string to hex, ignoring reserved characters (a-z)
1673  * and the characters in the exception list.
1674  *
1675  * Returns a new escaped string or NULL in case of error.
1676  */
1677 xmlChar *
1678 xmlURIEscapeStr(const xmlChar *str, const xmlChar *list) {
1679     xmlChar *ret, ch;
1680     xmlChar *temp;
1681     const xmlChar *in;
1682     int len, out;
1683 
1684     if (str == NULL)
1685 	return(NULL);
1686     if (str[0] == 0)
1687 	return(xmlStrdup(str));
1688     len = xmlStrlen(str);
1689     if (!(len > 0)) return(NULL);
1690 
1691     len += 20;
1692     ret = (xmlChar *) xmlMallocAtomic(len);
1693     if (ret == NULL) {
1694         xmlURIErrMemory("escaping URI value\n");
1695 	return(NULL);
1696     }
1697     in = (const xmlChar *) str;
1698     out = 0;
1699     while(*in != 0) {
1700 	if (len - out <= 3) {
1701             temp = xmlSaveUriRealloc(ret, &len);
1702 	    if (temp == NULL) {
1703                 xmlURIErrMemory("escaping URI value\n");
1704 		xmlFree(ret);
1705 		return(NULL);
1706 	    }
1707 	    ret = temp;
1708 	}
1709 
1710 	ch = *in;
1711 
1712 	if ((ch != '@') && (!IS_UNRESERVED(ch)) && (!xmlStrchr(list, ch))) {
1713 	    unsigned char val;
1714 	    ret[out++] = '%';
1715 	    val = ch >> 4;
1716 	    if (val <= 9)
1717 		ret[out++] = '0' + val;
1718 	    else
1719 		ret[out++] = 'A' + val - 0xA;
1720 	    val = ch & 0xF;
1721 	    if (val <= 9)
1722 		ret[out++] = '0' + val;
1723 	    else
1724 		ret[out++] = 'A' + val - 0xA;
1725 	    in++;
1726 	} else {
1727 	    ret[out++] = *in++;
1728 	}
1729 
1730     }
1731     ret[out] = 0;
1732     return(ret);
1733 }
1734 
1735 /**
1736  * xmlURIEscape:
1737  * @str:  the string of the URI to escape
1738  *
1739  * Escaping routine, does not do validity checks !
1740  * It will try to escape the chars needing this, but this is heuristic
1741  * based it's impossible to be sure.
1742  *
1743  * Returns an copy of the string, but escaped
1744  *
1745  * 25 May 2001
1746  * Uses xmlParseURI and xmlURIEscapeStr to try to escape correctly
1747  * according to RFC2396.
1748  *   - Carl Douglas
1749  */
1750 xmlChar *
1751 xmlURIEscape(const xmlChar * str)
1752 {
1753     xmlChar *ret, *segment = NULL;
1754     xmlURIPtr uri;
1755     int ret2;
1756 
1757     if (str == NULL)
1758         return (NULL);
1759 
1760     uri = xmlCreateURI();
1761     if (uri != NULL) {
1762 	/*
1763 	 * Allow escaping errors in the unescaped form
1764 	 */
1765         uri->cleanup = 1;
1766         ret2 = xmlParseURIReference(uri, (const char *)str);
1767         if (ret2) {
1768             xmlFreeURI(uri);
1769             return (NULL);
1770         }
1771     }
1772 
1773     if (!uri)
1774         return NULL;
1775 
1776     ret = NULL;
1777 
1778 #define NULLCHK(p) if(!p) { \
1779          xmlURIErrMemory("escaping URI value\n"); \
1780          xmlFreeURI(uri); \
1781          xmlFree(ret); \
1782          return NULL; } \
1783 
1784     if (uri->scheme) {
1785         segment = xmlURIEscapeStr(BAD_CAST uri->scheme, BAD_CAST "+-.");
1786         NULLCHK(segment)
1787         ret = xmlStrcat(ret, segment);
1788         ret = xmlStrcat(ret, BAD_CAST ":");
1789         xmlFree(segment);
1790     }
1791 
1792     if (uri->authority) {
1793         segment =
1794             xmlURIEscapeStr(BAD_CAST uri->authority, BAD_CAST "/?;:@");
1795         NULLCHK(segment)
1796         ret = xmlStrcat(ret, BAD_CAST "//");
1797         ret = xmlStrcat(ret, segment);
1798         xmlFree(segment);
1799     }
1800 
1801     if (uri->user) {
1802         segment = xmlURIEscapeStr(BAD_CAST uri->user, BAD_CAST ";:&=+$,");
1803         NULLCHK(segment)
1804         ret = xmlStrcat(ret,BAD_CAST "//");
1805         ret = xmlStrcat(ret, segment);
1806         ret = xmlStrcat(ret, BAD_CAST "@");
1807         xmlFree(segment);
1808     }
1809 
1810     if (uri->server) {
1811         segment = xmlURIEscapeStr(BAD_CAST uri->server, BAD_CAST "/?;:@");
1812         NULLCHK(segment)
1813         if (uri->user == NULL)
1814             ret = xmlStrcat(ret, BAD_CAST "//");
1815         ret = xmlStrcat(ret, segment);
1816         xmlFree(segment);
1817     }
1818 
1819     if (uri->port) {
1820         xmlChar port[10];
1821 
1822         snprintf((char *) port, 10, "%d", uri->port);
1823         ret = xmlStrcat(ret, BAD_CAST ":");
1824         ret = xmlStrcat(ret, port);
1825     }
1826 
1827     if (uri->path) {
1828         segment =
1829             xmlURIEscapeStr(BAD_CAST uri->path, BAD_CAST ":@&=+$,/?;");
1830         NULLCHK(segment)
1831         ret = xmlStrcat(ret, segment);
1832         xmlFree(segment);
1833     }
1834 
1835     if (uri->query_raw) {
1836         ret = xmlStrcat(ret, BAD_CAST "?");
1837         ret = xmlStrcat(ret, BAD_CAST uri->query_raw);
1838     }
1839     else if (uri->query) {
1840         segment =
1841             xmlURIEscapeStr(BAD_CAST uri->query, BAD_CAST ";/?:@&=+,$");
1842         NULLCHK(segment)
1843         ret = xmlStrcat(ret, BAD_CAST "?");
1844         ret = xmlStrcat(ret, segment);
1845         xmlFree(segment);
1846     }
1847 
1848     if (uri->opaque) {
1849         segment = xmlURIEscapeStr(BAD_CAST uri->opaque, BAD_CAST "");
1850         NULLCHK(segment)
1851         ret = xmlStrcat(ret, segment);
1852         xmlFree(segment);
1853     }
1854 
1855     if (uri->fragment) {
1856         segment = xmlURIEscapeStr(BAD_CAST uri->fragment, BAD_CAST "#");
1857         NULLCHK(segment)
1858         ret = xmlStrcat(ret, BAD_CAST "#");
1859         ret = xmlStrcat(ret, segment);
1860         xmlFree(segment);
1861     }
1862 
1863     xmlFreeURI(uri);
1864 #undef NULLCHK
1865 
1866     return (ret);
1867 }
1868 
1869 /************************************************************************
1870  *									*
1871  *			Public functions				*
1872  *									*
1873  ************************************************************************/
1874 
1875 /**
1876  * xmlBuildURI:
1877  * @URI:  the URI instance found in the document
1878  * @base:  the base value
1879  *
1880  * Computes he final URI of the reference done by checking that
1881  * the given URI is valid, and building the final URI using the
1882  * base URI. This is processed according to section 5.2 of the
1883  * RFC 2396
1884  *
1885  * 5.2. Resolving Relative References to Absolute Form
1886  *
1887  * Returns a new URI string (to be freed by the caller) or NULL in case
1888  *         of error.
1889  */
1890 xmlChar *
1891 xmlBuildURI(const xmlChar *URI, const xmlChar *base) {
1892     xmlChar *val = NULL;
1893     int ret, len, indx, cur, out;
1894     xmlURIPtr ref = NULL;
1895     xmlURIPtr bas = NULL;
1896     xmlURIPtr res = NULL;
1897 
1898     /*
1899      * 1) The URI reference is parsed into the potential four components and
1900      *    fragment identifier, as described in Section 4.3.
1901      *
1902      *    NOTE that a completely empty URI is treated by modern browsers
1903      *    as a reference to "." rather than as a synonym for the current
1904      *    URI.  Should we do that here?
1905      */
1906     if (URI == NULL)
1907 	ret = -1;
1908     else {
1909 	if (*URI) {
1910 	    ref = xmlCreateURI();
1911 	    if (ref == NULL)
1912 		goto done;
1913 	    ret = xmlParseURIReference(ref, (const char *) URI);
1914 	}
1915 	else
1916 	    ret = 0;
1917     }
1918     if (ret != 0)
1919 	goto done;
1920     if ((ref != NULL) && (ref->scheme != NULL)) {
1921 	/*
1922 	 * The URI is absolute don't modify.
1923 	 */
1924 	val = xmlStrdup(URI);
1925 	goto done;
1926     }
1927     if (base == NULL)
1928 	ret = -1;
1929     else {
1930 	bas = xmlCreateURI();
1931 	if (bas == NULL)
1932 	    goto done;
1933 	ret = xmlParseURIReference(bas, (const char *) base);
1934     }
1935     if (ret != 0) {
1936 	if (ref)
1937 	    val = xmlSaveUri(ref);
1938 	goto done;
1939     }
1940     if (ref == NULL) {
1941 	/*
1942 	 * the base fragment must be ignored
1943 	 */
1944 	if (bas->fragment != NULL) {
1945 	    xmlFree(bas->fragment);
1946 	    bas->fragment = NULL;
1947 	}
1948 	val = xmlSaveUri(bas);
1949 	goto done;
1950     }
1951 
1952     /*
1953      * 2) If the path component is empty and the scheme, authority, and
1954      *    query components are undefined, then it is a reference to the
1955      *    current document and we are done.  Otherwise, the reference URI's
1956      *    query and fragment components are defined as found (or not found)
1957      *    within the URI reference and not inherited from the base URI.
1958      *
1959      *    NOTE that in modern browsers, the parsing differs from the above
1960      *    in the following aspect:  the query component is allowed to be
1961      *    defined while still treating this as a reference to the current
1962      *    document.
1963      */
1964     res = xmlCreateURI();
1965     if (res == NULL)
1966 	goto done;
1967     if ((ref->scheme == NULL) && (ref->path == NULL) &&
1968 	((ref->authority == NULL) && (ref->server == NULL))) {
1969 	if (bas->scheme != NULL)
1970 	    res->scheme = xmlMemStrdup(bas->scheme);
1971 	if (bas->authority != NULL)
1972 	    res->authority = xmlMemStrdup(bas->authority);
1973 	else if ((bas->server != NULL) || (bas->port == -1)) {
1974 	    if (bas->server != NULL)
1975 		res->server = xmlMemStrdup(bas->server);
1976 	    if (bas->user != NULL)
1977 		res->user = xmlMemStrdup(bas->user);
1978 	    res->port = bas->port;
1979 	}
1980 	if (bas->path != NULL)
1981 	    res->path = xmlMemStrdup(bas->path);
1982 	if (ref->query_raw != NULL)
1983 	    res->query_raw = xmlMemStrdup (ref->query_raw);
1984 	else if (ref->query != NULL)
1985 	    res->query = xmlMemStrdup(ref->query);
1986 	else if (bas->query_raw != NULL)
1987 	    res->query_raw = xmlMemStrdup(bas->query_raw);
1988 	else if (bas->query != NULL)
1989 	    res->query = xmlMemStrdup(bas->query);
1990 	if (ref->fragment != NULL)
1991 	    res->fragment = xmlMemStrdup(ref->fragment);
1992 	goto step_7;
1993     }
1994 
1995     /*
1996      * 3) If the scheme component is defined, indicating that the reference
1997      *    starts with a scheme name, then the reference is interpreted as an
1998      *    absolute URI and we are done.  Otherwise, the reference URI's
1999      *    scheme is inherited from the base URI's scheme component.
2000      */
2001     if (ref->scheme != NULL) {
2002 	val = xmlSaveUri(ref);
2003 	goto done;
2004     }
2005     if (bas->scheme != NULL)
2006 	res->scheme = xmlMemStrdup(bas->scheme);
2007 
2008     if (ref->query_raw != NULL)
2009 	res->query_raw = xmlMemStrdup(ref->query_raw);
2010     else if (ref->query != NULL)
2011 	res->query = xmlMemStrdup(ref->query);
2012     if (ref->fragment != NULL)
2013 	res->fragment = xmlMemStrdup(ref->fragment);
2014 
2015     /*
2016      * 4) If the authority component is defined, then the reference is a
2017      *    network-path and we skip to step 7.  Otherwise, the reference
2018      *    URI's authority is inherited from the base URI's authority
2019      *    component, which will also be undefined if the URI scheme does not
2020      *    use an authority component.
2021      */
2022     if ((ref->authority != NULL) || (ref->server != NULL)) {
2023 	if (ref->authority != NULL)
2024 	    res->authority = xmlMemStrdup(ref->authority);
2025 	else {
2026 	    res->server = xmlMemStrdup(ref->server);
2027 	    if (ref->user != NULL)
2028 		res->user = xmlMemStrdup(ref->user);
2029             res->port = ref->port;
2030 	}
2031 	if (ref->path != NULL)
2032 	    res->path = xmlMemStrdup(ref->path);
2033 	goto step_7;
2034     }
2035     if (bas->authority != NULL)
2036 	res->authority = xmlMemStrdup(bas->authority);
2037     else if ((bas->server != NULL) || (bas->port == -1)) {
2038 	if (bas->server != NULL)
2039 	    res->server = xmlMemStrdup(bas->server);
2040 	if (bas->user != NULL)
2041 	    res->user = xmlMemStrdup(bas->user);
2042 	res->port = bas->port;
2043     }
2044 
2045     /*
2046      * 5) If the path component begins with a slash character ("/"), then
2047      *    the reference is an absolute-path and we skip to step 7.
2048      */
2049     if ((ref->path != NULL) && (ref->path[0] == '/')) {
2050 	res->path = xmlMemStrdup(ref->path);
2051 	goto step_7;
2052     }
2053 
2054 
2055     /*
2056      * 6) If this step is reached, then we are resolving a relative-path
2057      *    reference.  The relative path needs to be merged with the base
2058      *    URI's path.  Although there are many ways to do this, we will
2059      *    describe a simple method using a separate string buffer.
2060      *
2061      * Allocate a buffer large enough for the result string.
2062      */
2063     len = 2; /* extra / and 0 */
2064     if (ref->path != NULL)
2065 	len += strlen(ref->path);
2066     if (bas->path != NULL)
2067 	len += strlen(bas->path);
2068     res->path = (char *) xmlMallocAtomic(len);
2069     if (res->path == NULL) {
2070         xmlURIErrMemory("resolving URI against base\n");
2071 	goto done;
2072     }
2073     res->path[0] = 0;
2074 
2075     /*
2076      * a) All but the last segment of the base URI's path component is
2077      *    copied to the buffer.  In other words, any characters after the
2078      *    last (right-most) slash character, if any, are excluded.
2079      */
2080     cur = 0;
2081     out = 0;
2082     if (bas->path != NULL) {
2083 	while (bas->path[cur] != 0) {
2084 	    while ((bas->path[cur] != 0) && (bas->path[cur] != '/'))
2085 		cur++;
2086 	    if (bas->path[cur] == 0)
2087 		break;
2088 
2089 	    cur++;
2090 	    while (out < cur) {
2091 		res->path[out] = bas->path[out];
2092 		out++;
2093 	    }
2094 	}
2095     }
2096     res->path[out] = 0;
2097 
2098     /*
2099      * b) The reference's path component is appended to the buffer
2100      *    string.
2101      */
2102     if (ref->path != NULL && ref->path[0] != 0) {
2103 	indx = 0;
2104 	/*
2105 	 * Ensure the path includes a '/'
2106 	 */
2107 	if ((out == 0) && (bas->server != NULL))
2108 	    res->path[out++] = '/';
2109 	while (ref->path[indx] != 0) {
2110 	    res->path[out++] = ref->path[indx++];
2111 	}
2112     }
2113     res->path[out] = 0;
2114 
2115     /*
2116      * Steps c) to h) are really path normalization steps
2117      */
2118     xmlNormalizeURIPath(res->path);
2119 
2120 step_7:
2121 
2122     /*
2123      * 7) The resulting URI components, including any inherited from the
2124      *    base URI, are recombined to give the absolute form of the URI
2125      *    reference.
2126      */
2127     val = xmlSaveUri(res);
2128 
2129 done:
2130     if (ref != NULL)
2131 	xmlFreeURI(ref);
2132     if (bas != NULL)
2133 	xmlFreeURI(bas);
2134     if (res != NULL)
2135 	xmlFreeURI(res);
2136     return(val);
2137 }
2138 
2139 /**
2140  * xmlBuildRelativeURI:
2141  * @URI:  the URI reference under consideration
2142  * @base:  the base value
2143  *
2144  * Expresses the URI of the reference in terms relative to the
2145  * base.  Some examples of this operation include:
2146  *     base = "http://site1.com/docs/book1.html"
2147  *        URI input                        URI returned
2148  *     docs/pic1.gif                    pic1.gif
2149  *     docs/img/pic1.gif                img/pic1.gif
2150  *     img/pic1.gif                     ../img/pic1.gif
2151  *     http://site1.com/docs/pic1.gif   pic1.gif
2152  *     http://site2.com/docs/pic1.gif   http://site2.com/docs/pic1.gif
2153  *
2154  *     base = "docs/book1.html"
2155  *        URI input                        URI returned
2156  *     docs/pic1.gif                    pic1.gif
2157  *     docs/img/pic1.gif                img/pic1.gif
2158  *     img/pic1.gif                     ../img/pic1.gif
2159  *     http://site1.com/docs/pic1.gif   http://site1.com/docs/pic1.gif
2160  *
2161  *
2162  * Note: if the URI reference is really weird or complicated, it may be
2163  *       worthwhile to first convert it into a "nice" one by calling
2164  *       xmlBuildURI (using 'base') before calling this routine,
2165  *       since this routine (for reasonable efficiency) assumes URI has
2166  *       already been through some validation.
2167  *
2168  * Returns a new URI string (to be freed by the caller) or NULL in case
2169  * error.
2170  */
2171 xmlChar *
2172 xmlBuildRelativeURI (const xmlChar * URI, const xmlChar * base)
2173 {
2174     xmlChar *val = NULL;
2175     int ret;
2176     int ix;
2177     int nbslash = 0;
2178     int len;
2179     xmlURIPtr ref = NULL;
2180     xmlURIPtr bas = NULL;
2181     xmlChar *bptr, *uptr, *vptr;
2182     int remove_path = 0;
2183 
2184     if ((URI == NULL) || (*URI == 0))
2185 	return NULL;
2186 
2187     /*
2188      * First parse URI into a standard form
2189      */
2190     ref = xmlCreateURI ();
2191     if (ref == NULL)
2192 	return NULL;
2193     /* If URI not already in "relative" form */
2194     if (URI[0] != '.') {
2195 	ret = xmlParseURIReference (ref, (const char *) URI);
2196 	if (ret != 0)
2197 	    goto done;		/* Error in URI, return NULL */
2198     } else
2199 	ref->path = (char *)xmlStrdup(URI);
2200 
2201     /*
2202      * Next parse base into the same standard form
2203      */
2204     if ((base == NULL) || (*base == 0)) {
2205 	val = xmlStrdup (URI);
2206 	goto done;
2207     }
2208     bas = xmlCreateURI ();
2209     if (bas == NULL)
2210 	goto done;
2211     if (base[0] != '.') {
2212 	ret = xmlParseURIReference (bas, (const char *) base);
2213 	if (ret != 0)
2214 	    goto done;		/* Error in base, return NULL */
2215     } else
2216 	bas->path = (char *)xmlStrdup(base);
2217 
2218     /*
2219      * If the scheme / server on the URI differs from the base,
2220      * just return the URI
2221      */
2222     if ((ref->scheme != NULL) &&
2223 	((bas->scheme == NULL) ||
2224 	 (xmlStrcmp ((xmlChar *)bas->scheme, (xmlChar *)ref->scheme)) ||
2225 	 (xmlStrcmp ((xmlChar *)bas->server, (xmlChar *)ref->server)))) {
2226 	val = xmlStrdup (URI);
2227 	goto done;
2228     }
2229     if (xmlStrEqual((xmlChar *)bas->path, (xmlChar *)ref->path)) {
2230 	val = xmlStrdup(BAD_CAST "");
2231 	goto done;
2232     }
2233     if (bas->path == NULL) {
2234 	val = xmlStrdup((xmlChar *)ref->path);
2235 	goto done;
2236     }
2237     if (ref->path == NULL) {
2238         ref->path = (char *) "/";
2239 	remove_path = 1;
2240     }
2241 
2242     /*
2243      * At this point (at last!) we can compare the two paths
2244      *
2245      * First we take care of the special case where either of the
2246      * two path components may be missing (bug 316224)
2247      */
2248     bptr = (xmlChar *)bas->path;
2249     {
2250         xmlChar *rptr = (xmlChar *) ref->path;
2251         int pos = 0;
2252 
2253         /*
2254          * Next we compare the two strings and find where they first differ
2255          */
2256 	if ((*rptr == '.') && (rptr[1] == '/'))
2257             rptr += 2;
2258 	if ((*bptr == '.') && (bptr[1] == '/'))
2259             bptr += 2;
2260 	else if ((*bptr == '/') && (*rptr != '/'))
2261 	    bptr++;
2262 	while ((bptr[pos] == rptr[pos]) && (bptr[pos] != 0))
2263 	    pos++;
2264 
2265 	if (bptr[pos] == rptr[pos]) {
2266 	    val = xmlStrdup(BAD_CAST "");
2267 	    goto done;		/* (I can't imagine why anyone would do this) */
2268 	}
2269 
2270 	/*
2271 	 * In URI, "back up" to the last '/' encountered.  This will be the
2272 	 * beginning of the "unique" suffix of URI
2273 	 */
2274 	ix = pos;
2275 	for (; ix > 0; ix--) {
2276 	    if (rptr[ix - 1] == '/')
2277 		break;
2278 	}
2279 	uptr = (xmlChar *)&rptr[ix];
2280 
2281 	/*
2282 	 * In base, count the number of '/' from the differing point
2283 	 */
2284 	for (; bptr[ix] != 0; ix++) {
2285 	    if (bptr[ix] == '/')
2286 		nbslash++;
2287 	}
2288 
2289 	/*
2290 	 * e.g: URI="foo/" base="foo/bar" -> "./"
2291 	 */
2292 	if (nbslash == 0 && !uptr[0]) {
2293 	    val = xmlStrdup(BAD_CAST "./");
2294 	    goto done;
2295 	}
2296 
2297 	len = xmlStrlen (uptr) + 1;
2298     }
2299 
2300     if (nbslash == 0) {
2301 	if (uptr != NULL)
2302 	    /* exception characters from xmlSaveUri */
2303 	    val = xmlURIEscapeStr(uptr, BAD_CAST "/;&=+$,");
2304 	goto done;
2305     }
2306 
2307     /*
2308      * Allocate just enough space for the returned string -
2309      * length of the remainder of the URI, plus enough space
2310      * for the "../" groups, plus one for the terminator
2311      */
2312     val = (xmlChar *) xmlMalloc (len + 3 * nbslash);
2313     if (val == NULL) {
2314         xmlURIErrMemory("building relative URI\n");
2315 	goto done;
2316     }
2317     vptr = val;
2318     /*
2319      * Put in as many "../" as needed
2320      */
2321     for (; nbslash>0; nbslash--) {
2322 	*vptr++ = '.';
2323 	*vptr++ = '.';
2324 	*vptr++ = '/';
2325     }
2326     /*
2327      * Finish up with the end of the URI
2328      */
2329     if (uptr != NULL) {
2330         if ((vptr > val) && (len > 0) &&
2331 	    (uptr[0] == '/') && (vptr[-1] == '/')) {
2332 	    memcpy (vptr, uptr + 1, len - 1);
2333 	    vptr[len - 2] = 0;
2334 	} else {
2335 	    memcpy (vptr, uptr, len);
2336 	    vptr[len - 1] = 0;
2337 	}
2338     } else {
2339 	vptr[len - 1] = 0;
2340     }
2341 
2342     /* escape the freshly-built path */
2343     vptr = val;
2344 	/* exception characters from xmlSaveUri */
2345     val = xmlURIEscapeStr(vptr, BAD_CAST "/;&=+$,");
2346     xmlFree(vptr);
2347 
2348 done:
2349     /*
2350      * Free the working variables
2351      */
2352     if (remove_path != 0)
2353         ref->path = NULL;
2354     if (ref != NULL)
2355 	xmlFreeURI (ref);
2356     if (bas != NULL)
2357 	xmlFreeURI (bas);
2358 
2359     return val;
2360 }
2361 
2362 /**
2363  * xmlCanonicPath:
2364  * @path:  the resource locator in a filesystem notation
2365  *
2366  * Constructs a canonic path from the specified path.
2367  *
2368  * Returns a new canonic path, or a duplicate of the path parameter if the
2369  * construction fails. The caller is responsible for freeing the memory occupied
2370  * by the returned string. If there is insufficient memory available, or the
2371  * argument is NULL, the function returns NULL.
2372  */
2373 #define IS_WINDOWS_PATH(p)					\
2374 	((p != NULL) &&						\
2375 	 (((p[0] >= 'a') && (p[0] <= 'z')) ||			\
2376 	  ((p[0] >= 'A') && (p[0] <= 'Z'))) &&			\
2377 	 (p[1] == ':') && ((p[2] == '/') || (p[2] == '\\')))
2378 xmlChar *
2379 xmlCanonicPath(const xmlChar *path)
2380 {
2381 /*
2382  * For Windows implementations, additional work needs to be done to
2383  * replace backslashes in pathnames with "forward slashes"
2384  */
2385 #if defined(_WIN32) && !defined(__CYGWIN__)
2386     int len = 0;
2387     char *p = NULL;
2388 #endif
2389     xmlURIPtr uri;
2390     xmlChar *ret;
2391     const xmlChar *absuri;
2392 
2393     if (path == NULL)
2394 	return(NULL);
2395 
2396 #if defined(_WIN32)
2397     /*
2398      * We must not change the backslashes to slashes if the the path
2399      * starts with \\?\
2400      * Those paths can be up to 32k characters long.
2401      * Was added specifically for OpenOffice, those paths can't be converted
2402      * to URIs anyway.
2403      */
2404     if ((path[0] == '\\') && (path[1] == '\\') && (path[2] == '?') &&
2405         (path[3] == '\\') )
2406 	return xmlStrdup((const xmlChar *) path);
2407 #endif
2408 
2409 	/* sanitize filename starting with // so it can be used as URI */
2410     if ((path[0] == '/') && (path[1] == '/') && (path[2] != '/'))
2411         path++;
2412 
2413     if ((uri = xmlParseURI((const char *) path)) != NULL) {
2414 	xmlFreeURI(uri);
2415 	return xmlStrdup(path);
2416     }
2417 
2418     /* Check if this is an "absolute uri" */
2419     absuri = xmlStrstr(path, BAD_CAST "://");
2420     if (absuri != NULL) {
2421         int l, j;
2422 	unsigned char c;
2423 	xmlChar *escURI;
2424 
2425         /*
2426 	 * this looks like an URI where some parts have not been
2427 	 * escaped leading to a parsing problem.  Check that the first
2428 	 * part matches a protocol.
2429 	 */
2430 	l = absuri - path;
2431 	/* Bypass if first part (part before the '://') is > 20 chars */
2432 	if ((l <= 0) || (l > 20))
2433 	    goto path_processing;
2434 	/* Bypass if any non-alpha characters are present in first part */
2435 	for (j = 0;j < l;j++) {
2436 	    c = path[j];
2437 	    if (!(((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'))))
2438 	        goto path_processing;
2439 	}
2440 
2441 	/* Escape all except the characters specified in the supplied path */
2442         escURI = xmlURIEscapeStr(path, BAD_CAST ":/?_.#&;=");
2443 	if (escURI != NULL) {
2444 	    /* Try parsing the escaped path */
2445 	    uri = xmlParseURI((const char *) escURI);
2446 	    /* If successful, return the escaped string */
2447 	    if (uri != NULL) {
2448 	        xmlFreeURI(uri);
2449 		return escURI;
2450 	    }
2451             xmlFree(escURI);
2452 	}
2453     }
2454 
2455 path_processing:
2456 /* For Windows implementations, replace backslashes with 'forward slashes' */
2457 #if defined(_WIN32) && !defined(__CYGWIN__)
2458     /*
2459      * Create a URI structure
2460      */
2461     uri = xmlCreateURI();
2462     if (uri == NULL) {		/* Guard against 'out of memory' */
2463         return(NULL);
2464     }
2465 
2466     len = xmlStrlen(path);
2467     if ((len > 2) && IS_WINDOWS_PATH(path)) {
2468         /* make the scheme 'file' */
2469 	uri->scheme = (char *) xmlStrdup(BAD_CAST "file");
2470 	/* allocate space for leading '/' + path + string terminator */
2471 	uri->path = xmlMallocAtomic(len + 2);
2472 	if (uri->path == NULL) {
2473 	    xmlFreeURI(uri);	/* Guard against 'out of memory' */
2474 	    return(NULL);
2475 	}
2476 	/* Put in leading '/' plus path */
2477 	uri->path[0] = '/';
2478 	p = uri->path + 1;
2479 	strncpy(p, (char *) path, len + 1);
2480     } else {
2481 	uri->path = (char *) xmlStrdup(path);
2482 	if (uri->path == NULL) {
2483 	    xmlFreeURI(uri);
2484 	    return(NULL);
2485 	}
2486 	p = uri->path;
2487     }
2488     /* Now change all occurrences of '\' to '/' */
2489     while (*p != '\0') {
2490 	if (*p == '\\')
2491 	    *p = '/';
2492 	p++;
2493     }
2494 
2495     if (uri->scheme == NULL) {
2496 	ret = xmlStrdup((const xmlChar *) uri->path);
2497     } else {
2498 	ret = xmlSaveUri(uri);
2499     }
2500 
2501     xmlFreeURI(uri);
2502 #else
2503     ret = xmlStrdup((const xmlChar *) path);
2504 #endif
2505     return(ret);
2506 }
2507 
2508 /**
2509  * xmlPathToURI:
2510  * @path:  the resource locator in a filesystem notation
2511  *
2512  * Constructs an URI expressing the existing path
2513  *
2514  * Returns a new URI, or a duplicate of the path parameter if the
2515  * construction fails. The caller is responsible for freeing the memory
2516  * occupied by the returned string. If there is insufficient memory available,
2517  * or the argument is NULL, the function returns NULL.
2518  */
2519 xmlChar *
2520 xmlPathToURI(const xmlChar *path)
2521 {
2522     xmlURIPtr uri;
2523     xmlURI temp;
2524     xmlChar *ret, *cal;
2525 
2526     if (path == NULL)
2527         return(NULL);
2528 
2529     if ((uri = xmlParseURI((const char *) path)) != NULL) {
2530 	xmlFreeURI(uri);
2531 	return xmlStrdup(path);
2532     }
2533     cal = xmlCanonicPath(path);
2534     if (cal == NULL)
2535         return(NULL);
2536 #if defined(_WIN32) && !defined(__CYGWIN__)
2537     /* xmlCanonicPath can return an URI on Windows (is that the intended behaviour?)
2538        If 'cal' is a valid URI already then we are done here, as continuing would make
2539        it invalid. */
2540     if ((uri = xmlParseURI((const char *) cal)) != NULL) {
2541 	xmlFreeURI(uri);
2542 	return cal;
2543     }
2544     /* 'cal' can contain a relative path with backslashes. If that is processed
2545        by xmlSaveURI, they will be escaped and the external entity loader machinery
2546        will fail. So convert them to slashes. Misuse 'ret' for walking. */
2547     ret = cal;
2548     while (*ret != '\0') {
2549 	if (*ret == '\\')
2550 	    *ret = '/';
2551 	ret++;
2552     }
2553 #endif
2554     memset(&temp, 0, sizeof(temp));
2555     temp.path = (char *) cal;
2556     ret = xmlSaveUri(&temp);
2557     xmlFree(cal);
2558     return(ret);
2559 }
2560 #define bottom_uri
2561 #include "elfgcchack.h"
2562