1 /*
2 * This is a URL parser, written to parse "Common Internet Scheme" URL
3 * syntax as described in RFC1738 and updated by RFC2396. Only absolute URLs
4 * are supported, using "server-based" naming authorities in the schemes.
5 * Support for literal IPv6 addresses is included, per RFC2732.
6 *
7 * Current "known" schemes: http, ftp, file.
8 *
9 * We can do all the parsing operations without Runes since URLs are
10 * defined to be composed of US-ASCII printable characters.
11 * See RFC1738, RFC2396.
12 */
13
14 #include <u.h>
15 #include <libc.h>
16 #include <ctype.h>
17 #include <regexp.h>
18 #include <plumb.h>
19 #include <thread.h>
20 #include <fcall.h>
21 #include <9p.h>
22 #include "dat.h"
23 #include "fns.h"
24
25 int urldebug;
26
27 /* If set, relative paths with leading ".." segments will have them trimmed */
28 #define RemoveExtraRelDotDots 0
29 #define ExpandCurrentDocUrls 1
30
31 static char*
32 schemestrtab[] =
33 {
34 nil,
35 "http",
36 "https",
37 "ftp",
38 "file",
39 };
40
41 static int
ischeme(char * s)42 ischeme(char *s)
43 {
44 int i;
45
46 for(i=0; i<nelem(schemestrtab); i++)
47 if(schemestrtab[i] && strcmp(s, schemestrtab[i])==0)
48 return i;
49 return USunknown;
50 }
51
52 /*
53 * URI splitting regexp is from RFC2396, Appendix B:
54 * ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
55 * 12 3 4 5 6 7 8 9
56 *
57 * Example: "http://www.ics.uci.edu/pub/ietf/uri/#Related"
58 * $2 = scheme "http"
59 * $4 = authority "www.ics.uci.edu"
60 * $5 = path "/pub/ietf/uri/"
61 * $7 = query <undefined>
62 * $9 = fragment "Related"
63 */
64
65 /*
66 * RFC2396, Sec 3.1, contains:
67 *
68 * Scheme names consist of a sequence of characters beginning with a
69 * lower case letter and followed by any combination of lower case
70 * letters, digits, plus ("+"), period ("."), or hyphen ("-"). For
71 * resiliency, programs interpreting URI should treat upper case letters
72 * as equivalent to lower case in scheme names (e.g., allow "HTTP" as
73 * well as "http").
74 */
75
76 /*
77 * For server-based naming authorities (RFC2396 Sec 3.2.2):
78 * server = [ [ userinfo "@" ] hostport ]
79 * userinfo = *( unreserved | escaped |
80 * ";" | ":" | "&" | "=" | "+" | "$" | "," )
81 * hostport = host [ ":" port ]
82 * host = hostname | IPv4address
83 * hostname = *( domainlabel "." ) toplabel [ "." ]
84 * domainlabel = alphanum | alphanum *( alphanum | "-" ) alphanum
85 * toplabel = alpha | alpha *( alphanum | "-" ) alphanum
86 * IPv4address = 1*digit "." 1*digit "." 1*digit "." 1*digit
87 * port = *digit
88 *
89 * The host is a domain name of a network host, or its IPv4 address as a
90 * set of four decimal digit groups separated by ".". Literal IPv6
91 * addresses are not supported.
92 *
93 * Note that literal IPv6 address support is outlined in RFC2732:
94 * host = hostname | IPv4address | IPv6reference
95 * ipv6reference = "[" IPv6address "]" (RFC2373)
96 *
97 * Since hostnames and numbers will have to be resolved by the OS anyway,
98 * we don't have to parse them too pedantically (counting '.'s, checking
99 * for well-formed literal IP addresses, etc.).
100 *
101 * In FTP/file paths, we reject most ";param"s and querys. In HTTP paths,
102 * we just pass them through.
103 *
104 * Instead of letting a "path" be 0-or-more characters as RFC2396 suggests,
105 * we'll say it's 1-or-more characters, 0-or-1 times. This way, an absent
106 * path yields a nil substring match, instead of an empty one.
107 *
108 * We're more restrictive than RFC2396 indicates with "userinfo" strings,
109 * insisting they have the form "[user[:password]]". This may need to
110 * change at some point, however.
111 */
112
113 /* RE character-class components -- these go in brackets */
114 #define PUNCT "\\-_.!~*'()"
115 #define RES ";/?:@&=+$,"
116 #define ALNUM "a-zA-Z0-9"
117 #define HEX "0-9a-fA-F"
118 #define UNRES ALNUM PUNCT
119
120 /* RE components; _N => has N parenthesized subexpressions when expanded */
121 #define ESCAPED_1 "(%[" HEX "][" HEX "])"
122 #define URIC_2 "([" RES UNRES "]|" ESCAPED_1 ")"
123 #define URICNOSLASH_2 "([" UNRES ";?:@&=+$,]|" ESCAPED_1 ")"
124 #define USERINFO_2 "([" UNRES ";:&=+$,]|" ESCAPED_1 ")"
125 #define PCHAR_2 "([" UNRES ":@&=+$,]|" ESCAPED_1 ")"
126 #define PSEGCHAR_3 "([/;]|" PCHAR_2 ")"
127
128 typedef struct Retab Retab;
129 struct Retab
130 {
131 char *str;
132 Reprog *prog;
133 int size;
134 int ind[5];
135 };
136
137 enum
138 {
139 REsplit = 0,
140 REscheme,
141 REunknowndata,
142 REauthority,
143 REhost,
144 REuserinfo,
145 REabspath,
146 REquery,
147 REfragment,
148 REhttppath,
149 REftppath,
150 REfilepath,
151
152 MaxResub= 20,
153 };
154
155 Retab retab[] = /* view in constant width Font */
156 {
157 [REsplit]
158 "^(([^:/?#]+):)?(//([^/?#]*))?([^?#]+)?(\\?([^#]*))?(#(.*))?$", nil, 0,
159 /* |-scheme-| |-auth.-| |path--| |query| |--|frag */
160 { 2, 4, 5, 7, 9},
161
162 [REscheme]
163 "^[a-z][a-z0-9+-.]*$", nil, 0,
164 { 0, },
165
166 [REunknowndata]
167 "^" URICNOSLASH_2 URIC_2 "*$", nil, 0,
168 { 0, },
169
170 [REauthority]
171 "^(((" USERINFO_2 "*)@)?(((\\[[^\\]@]+\\])|([^:\\[@]+))(:([0-9]*))?)?)?$", nil, 0,
172 /* |----user info-----| |--------host----------------| |-port-| */
173 { 3, 7, 11, },
174
175 [REhost]
176 "^(([a-zA-Z0-9\\-.]+)|(\\[([a-fA-F0-9.:]+)\\]))$", nil, 0,
177 /* |--regular host--| |-IPv6 literal-| */
178 { 2, 4, },
179
180 [REuserinfo]
181 "^(([^:]*)(:([^:]*))?)$", nil, 0,
182 /* |user-| |pass-| */
183 { 2, 4, },
184
185 [REabspath]
186 "^/" PSEGCHAR_3 "*$", nil, 0,
187 { 0, },
188
189 [REquery]
190 "^" URIC_2 "*$", nil, 0,
191 { 0, },
192
193 [REfragment]
194 "^" URIC_2 "*$", nil, 0,
195 { 0, },
196
197 [REhttppath]
198 "^.*$", nil, 0,
199 { 0, },
200
201 [REftppath]
202 "^(.+)(;[tT][yY][pP][eE]=([aAiIdD]))?$", nil, 0,
203 /*|--|-path |ftptype-| */
204 { 1, 3, },
205
206 [REfilepath]
207 "^.*$", nil, 0,
208 { 0, },
209 };
210
211 static int
countleftparen(char * s)212 countleftparen(char *s)
213 {
214 int n;
215
216 n = 0;
217 for(; *s; s++)
218 if(*s == '(')
219 n++;
220 return n;
221 }
222
223 void
initurl(void)224 initurl(void)
225 {
226 int i, j;
227
228 for(i=0; i<nelem(retab); i++){
229 retab[i].prog = regcomp(retab[i].str);
230 if(retab[i].prog == nil)
231 sysfatal("recomp(%s): %r", retab[i].str);
232 retab[i].size = countleftparen(retab[i].str)+1;
233 for(j=0; j<nelem(retab[i].ind); j++)
234 if(retab[i].ind[j] >= retab[i].size)
235 sysfatal("bad index in regexp table: retab[%d].ind[%d] = %d >= %d",
236 i, j, retab[i].ind[j], retab[i].size);
237 if(MaxResub < retab[i].size)
238 sysfatal("MaxResub too small: %d < %d", MaxResub, retab[i].size);
239 }
240 }
241
242 typedef struct SplitUrl SplitUrl;
243 struct SplitUrl
244 {
245 struct {
246 char *s;
247 char *e;
248 } url, scheme, authority, path, query, fragment;
249 };
250
251 /*
252 * Implements the algorithm in RFC2396 sec 5.2 step 6.
253 * Returns number of chars written, excluding NUL terminator.
254 * dest is known to be >= strlen(base)+rel_len.
255 */
256 static void
merge_relative_path(char * base,char * rel_st,int rel_len,char * dest)257 merge_relative_path(char *base, char *rel_st, int rel_len, char *dest)
258 {
259 char *s, *p, *e, *pdest;
260
261 pdest = dest;
262
263 /* 6a: start with base, discard last segment */
264 if(base && base[0]){
265 /* Empty paths don't match in our scheme; 'base' should be nil */
266 assert(base[0] == '/');
267 e = strrchr(base, '/');
268 e++;
269 memmove(pdest, base, e-base);
270 pdest += e-base;
271 }else{
272 /* Artistic license on my part */
273 *pdest++ = '/';
274 }
275
276 /* 6b: append relative component */
277 if(rel_st){
278 memmove(pdest, rel_st, rel_len);
279 pdest += rel_len;
280 }
281
282 /* 6c: remove any occurrences of "./" as a complete segment */
283 s = dest;
284 *pdest = '\0';
285 while(e = strstr(s, "./")){
286 if((e == dest) || (*(e-1) == '/')){
287 memmove(e, e+2, pdest+1-(e+2)); /* +1 for NUL */
288 pdest -= 2;
289 }else
290 s = e+1;
291 }
292
293 /* 6d: remove a trailing "." as a complete segment */
294 if(pdest>dest && *(pdest-1)=='.' &&
295 (pdest==dest+1 || *(pdest-2)=='/'))
296 *--pdest = '\0';
297
298 /* 6e: remove occurences of "seg/../", where seg != "..", left->right */
299 s = dest+1;
300 while(e = strstr(s, "/../")){
301 p = e - 1;
302 while(p >= dest && *p != '/')
303 p--;
304 if(memcmp(p, "/../", 4) != 0){
305 memmove(p+1, e+4, pdest+1-(e+4));
306 pdest -= (e+4) - (p+1);
307 }else
308 s = e+1;
309 }
310
311 /* 6f: remove a trailing "seg/..", where seg isn't ".." */
312 if(pdest-3 > dest && memcmp(pdest-3, "/..", 3)==0){
313 p = pdest-3 - 1;
314 while(p >= dest && *p != '/')
315 p--;
316 if(memcmp(p, "/../", 4) != 0){
317 pdest = p+1;
318 *pdest = '\0';
319 }
320 }
321
322 /* 6g: leading ".." segments are errors -- we'll just blat them out. */
323 if(RemoveExtraRelDotDots){
324 p = dest;
325 if (p[0] == '/')
326 p++;
327 s = p;
328 while(s[0]=='.' && s[1]=='.' && (s[2]==0 || s[2]=='/'))
329 s += 3;
330 if(s > p){
331 memmove(p, s, pdest+1-s);
332 pdest -= s-p;
333 }
334 }
335 USED(pdest);
336
337 if(urldebug)
338 fprint(2, "merge_relative_path: '%s' + '%.*s' -> '%s'\n", base, rel_len,
339 rel_st, dest);
340 }
341
342 /*
343 * See RFC2396 sec 5.2 for info on resolving relative URIs to absolute form.
344 *
345 * If successful, this just ends up freeing and replacing "u->url".
346 */
347 static int
resolve_relative(SplitUrl * su,Url * base,Url * u)348 resolve_relative(SplitUrl *su, Url *base, Url *u)
349 {
350 char *url, *path;
351 char *purl, *ppath;
352 int currentdoc, ulen, plen;
353
354 if(base == nil){
355 werrstr("relative URI given without base");
356 return -1;
357 }
358 if(base->scheme == nil){
359 werrstr("relative URI given with no scheme");
360 return -1;
361 }
362 if(base->ischeme == USunknown){
363 werrstr("relative URI given with unknown scheme");
364 return -1;
365 }
366 if(base->ischeme == UScurrent){
367 werrstr("relative URI given with incomplete base");
368 return -1;
369 }
370 assert(su->scheme.s == nil);
371
372 /* Sec 5.2 step 2 */
373 currentdoc = 0;
374 if(su->path.s==nil && su->scheme.s==nil && su->authority.s==nil && su->query.s==nil){
375 /* Reference is to current document */
376 if(urldebug)
377 fprint(2, "url %s is relative to current document\n", u->url);
378 u->ischeme = UScurrent;
379 if(!ExpandCurrentDocUrls)
380 return 0;
381 currentdoc = 1;
382 }
383
384 /* Over-estimate the maximum lengths, for allocation purposes */
385 /* (constants are for separators) */
386 plen = 1;
387 if(base->path)
388 plen += strlen(base->path);
389 if(su->path.s)
390 plen += 1 + (su->path.e - su->path.s);
391
392 ulen = 0;
393 ulen += strlen(base->scheme) + 1;
394 if(su->authority.s)
395 ulen += 2 + (su->authority.e - su->authority.s);
396 else
397 ulen += 2 + ((base->authority) ? strlen(base->authority) : 0);
398 ulen += plen;
399 if(su->query.s)
400 ulen += 1 + (su->query.e - su->query.s);
401 else if(currentdoc && base->query)
402 ulen += 1 + strlen(base->query);
403 if(su->fragment.s)
404 ulen += 1 + (su->fragment.e - su->fragment.s);
405 else if(currentdoc && base->fragment)
406 ulen += 1 + strlen(base->fragment);
407 url = emalloc(ulen+1);
408 path = emalloc(plen+1);
409
410 url[0] = '\0';
411 purl = url;
412 path[0] = '\0';
413 ppath = path;
414
415 if(su->authority.s || (su->path.s && (su->path.s[0] == '/'))){
416 /* Is a "network-path" or "absolute-path"; don't merge with base path */
417 /* Sec 5.2 steps 4,5 */
418 if(su->path.s){
419 memmove(ppath, su->path.s, su->path.e - su->path.s);
420 ppath += su->path.e - su->path.s;
421 *ppath = '\0';
422 }
423 }else if(currentdoc){
424 /* Is a current-doc reference; just copy the path from the base URL */
425 if(base->path){
426 strcpy(ppath, base->path);
427 ppath += strlen(ppath);
428 }
429 USED(ppath);
430 }else{
431 /* Is a relative-path reference; we have to merge it */
432 /* Sec 5.2 step 6 */
433 merge_relative_path(base->path,
434 su->path.s, su->path.e - su->path.s, ppath);
435 }
436
437 /* Build new URL from pieces, inheriting from base where needed */
438 strcpy(purl, base->scheme);
439 purl += strlen(purl);
440 *purl++ = ':';
441 if(su->authority.s){
442 strcpy(purl, "//");
443 purl += strlen(purl);
444 memmove(purl, su->authority.s, su->authority.e - su->authority.s);
445 purl += su->authority.e - su->authority.s;
446 }else if(base->authority){
447 strcpy(purl, "//");
448 purl += strlen(purl);
449 strcpy(purl, base->authority);
450 purl += strlen(purl);
451 }
452 assert((path[0] == '\0') || (path[0] == '/'));
453 strcpy(purl, path);
454 purl += strlen(purl);
455
456 /*
457 * The query and fragment are not inherited from the base,
458 * except in case of "current document" URLs, which inherit any query
459 * and may inherit the fragment.
460 */
461 if(su->query.s){
462 *purl++ = '?';
463 memmove(purl, su->query.s, su->query.e - su->query.s);
464 purl += su->query.e - su->query.s;
465 }else if(currentdoc && base->query){
466 *purl++ = '?';
467 strcpy(purl, base->query);
468 purl += strlen(purl);
469 }
470
471 if(su->fragment.s){
472 *purl++ = '#';
473 memmove(purl, su->query.s, su->query.e - su->query.s);
474 purl += su->fragment.e - su->fragment.s;
475 }else if(currentdoc && base->fragment){
476 *purl++ = '#';
477 strcpy(purl, base->fragment);
478 purl += strlen(purl);
479 }
480 USED(purl);
481
482 if(urldebug)
483 fprint(2, "resolve_relative: '%s' + '%s' -> '%s'\n", base->url, u->url, url);
484 free(u->url);
485 u->url = url;
486 free(path);
487 return 0;
488 }
489
490 int
regx(Reprog * prog,char * s,Resub * m,int nm)491 regx(Reprog *prog, char *s, Resub *m, int nm)
492 {
493 int i;
494
495 if(s == nil)
496 s = m[0].sp; /* why is this necessary? */
497
498 i = regexec(prog, s, m, nm);
499 /*
500 if(i >= 0)
501 for(j=0; j<nm; j++)
502 fprint(2, "match%d: %.*s\n", j, utfnlen(m[j].sp, m[j].ep-m[j].sp), m[j].sp);
503 */
504 return i;
505 }
506
507 static int
ismatch(int i,char * s,char * desc)508 ismatch(int i, char *s, char *desc)
509 {
510 Resub m[1];
511
512 m[0].sp = m[0].ep = nil;
513 if(!regx(retab[i].prog, s, m, 1)){
514 werrstr("malformed %s: %q", desc, s);
515 return 0;
516 }
517 return 1;
518 }
519
520 static int
spliturl(char * url,SplitUrl * su)521 spliturl(char *url, SplitUrl *su)
522 {
523 Resub m[MaxResub];
524 Retab *t;
525
526 /*
527 * Newlines are not valid in a URI, but regexp(2) treats them specially
528 * so it's best to make sure there are none before proceeding.
529 */
530 if(strchr(url, '\n')){
531 werrstr("newline in URI");
532 return -1;
533 }
534
535 /*
536 * Because we use NUL-terminated strings, as do many client and server
537 * implementations, an escaped NUL ("%00") will quite likely cause problems
538 * when unescaped. We can check for such a sequence once before examining
539 * the components because, per RFC2396 sec. 2.4.1 - 2.4.2, '%' is reserved
540 * in URIs to _always_ indicate escape sequences. Something like "%2500"
541 * will still get by, but that's legitimate, and if it ends up causing
542 * a NUL then someone is unescaping too many times.
543 */
544 if(strstr(url, "%00")){
545 werrstr("escaped NUL in URI");
546 return -1;
547 }
548
549 m[0].sp = m[0].ep = nil;
550 t = &retab[REsplit];
551 if(!regx(t->prog, url, m, t->size)){
552 werrstr("malformed URI: %q", url);
553 return -1;
554 }
555
556 su->url.s = m[0].sp;
557 su->url.e = m[0].ep;
558 su->scheme.s = m[t->ind[0]].sp;
559 su->scheme.e = m[t->ind[0]].ep;
560 su->authority.s = m[t->ind[1]].sp;
561 su->authority.e = m[t->ind[1]].ep;
562 su->path.s = m[t->ind[2]].sp;
563 su->path.e = m[t->ind[2]].ep;
564 su->query.s = m[t->ind[3]].sp;
565 su->query.e = m[t->ind[3]].ep;
566 su->fragment.s = m[t->ind[4]].sp;
567 su->fragment.e = m[t->ind[4]].ep;
568
569 if(urldebug)
570 fprint(2, "split url %s into %.*q %.*q %.*q %.*q %.*q %.*q\n",
571 url,
572 su->url.s ? utfnlen(su->url.s, su->url.e-su->url.s) : 10, su->url.s ? su->url.s : "",
573 su->scheme.s ? utfnlen(su->scheme.s, su->scheme.e-su->scheme.s) : 10, su->scheme.s ? su->scheme.s : "",
574 su->authority.s ? utfnlen(su->authority.s, su->authority.e-su->authority.s) : 10, su->authority.s ? su->authority.s : "",
575 su->path.s ? utfnlen(su->path.s, su->path.e-su->path.s) : 10, su->path.s ? su->path.s : "",
576 su->query.s ? utfnlen(su->query.s, su->query.e-su->query.s) : 10, su->query.s ? su->query.s : "",
577 su->fragment.s ? utfnlen(su->fragment.s, su->fragment.e-su->fragment.s) : 10, su->fragment.s ? su->fragment.s : "");
578
579 return 0;
580 }
581
582 static int
parse_scheme(SplitUrl * su,Url * u)583 parse_scheme(SplitUrl *su, Url *u)
584 {
585 if(su->scheme.s == nil){
586 werrstr("missing scheme");
587 return -1;
588 }
589 u->scheme = estredup(su->scheme.s, su->scheme.e);
590 strlower(u->scheme);
591
592 if(!ismatch(REscheme, u->scheme, "scheme"))
593 return -1;
594
595 u->ischeme = ischeme(u->scheme);
596 if(urldebug)
597 fprint(2, "parse_scheme %s => %d\n", u->scheme, u->ischeme);
598 return 0;
599 }
600
601 static int
parse_unknown_part(SplitUrl * su,Url * u)602 parse_unknown_part(SplitUrl *su, Url *u)
603 {
604 char *s, *e;
605
606 assert(u->ischeme == USunknown);
607 assert(su->scheme.e[0] == ':');
608
609 s = su->scheme.e+1;
610 if(su->fragment.s){
611 e = su->fragment.s-1;
612 assert(*e == '#');
613 }else
614 e = s+strlen(s);
615
616 u->schemedata = estredup(s, e);
617 if(!ismatch(REunknowndata, u->schemedata, "unknown scheme data"))
618 return -1;
619 return 0;
620 }
621
622 static int
parse_userinfo(char * s,char * e,Url * u)623 parse_userinfo(char *s, char *e, Url *u)
624 {
625 Resub m[MaxResub];
626 Retab *t;
627
628 m[0].sp = s;
629 m[0].ep = e;
630 t = &retab[REuserinfo];
631 if(!regx(t->prog, nil, m, t->size)){
632 werrstr("malformed userinfo: %.*q", utfnlen(s, e-s), s);
633 return -1;
634 }
635 if(m[t->ind[0]].sp)
636 u->user = estredup(m[t->ind[0]].sp, m[t->ind[0]].ep);
637 if(m[t->ind[1]].sp)
638 u->user = estredup(m[t->ind[1]].sp, m[t->ind[1]].ep);
639 return 0;
640 }
641
642 static int
parse_host(char * s,char * e,Url * u)643 parse_host(char *s, char *e, Url *u)
644 {
645 Resub m[MaxResub];
646 Retab *t;
647
648 m[0].sp = s;
649 m[0].ep = e;
650 t = &retab[REhost];
651 if(!regx(t->prog, nil, m, t->size)){
652 werrstr("malformed host: %.*q", utfnlen(s, e-s), s);
653 return -1;
654 }
655
656 assert(m[t->ind[0]].sp || m[t->ind[1]].sp);
657
658 if(m[t->ind[0]].sp) /* regular */
659 u->host = estredup(m[t->ind[0]].sp, m[t->ind[0]].ep);
660 else
661 u->host = estredup(m[t->ind[1]].sp, m[t->ind[1]].ep);
662 return 0;
663 }
664
665 static int
parse_authority(SplitUrl * su,Url * u)666 parse_authority(SplitUrl *su, Url *u)
667 {
668 Resub m[MaxResub];
669 Retab *t;
670 char *host;
671 char *userinfo;
672
673 if(su->authority.s == nil)
674 return 0;
675
676 u->authority = estredup(su->authority.s, su->authority.e);
677 m[0].sp = m[0].ep = nil;
678 t = &retab[REauthority];
679 if(!regx(t->prog, u->authority, m, t->size)){
680 werrstr("malformed authority: %q", u->authority);
681 return -1;
682 }
683
684 if(m[t->ind[0]].sp)
685 if(parse_userinfo(m[t->ind[0]].sp, m[t->ind[0]].ep, u) < 0)
686 return -1;
687 if(m[t->ind[1]].sp)
688 if(parse_host(m[t->ind[1]].sp, m[t->ind[1]].ep, u) < 0)
689 return -1;
690 if(m[t->ind[2]].sp)
691 u->port = estredup(m[t->ind[2]].sp, m[t->ind[2]].ep);
692
693
694 if(urldebug > 0){
695 userinfo = estredup(m[t->ind[0]].sp, m[t->ind[0]].ep);
696 host = estredup(m[t->ind[1]].sp, m[t->ind[1]].ep);
697 fprint(2, "port: %q, authority %q\n", u->port, u->authority);
698 fprint(2, "host %q, userinfo %q\n", host, userinfo);
699 free(host);
700 free(userinfo);
701 }
702 return 0;
703 }
704
705 static int
parse_abspath(SplitUrl * su,Url * u)706 parse_abspath(SplitUrl *su, Url *u)
707 {
708 if(su->path.s == nil)
709 return 0;
710 u->path = estredup(su->path.s, su->path.e);
711 if(!ismatch(REabspath, u->path, "absolute path"))
712 return -1;
713 return 0;
714 }
715
716 static int
parse_query(SplitUrl * su,Url * u)717 parse_query(SplitUrl *su, Url *u)
718 {
719 if(su->query.s == nil)
720 return 0;
721 u->query = estredup(su->query.s, su->query.e);
722 if(!ismatch(REquery, u->query, "query"))
723 return -1;
724 return 0;
725 }
726
727 static int
parse_fragment(SplitUrl * su,Url * u)728 parse_fragment(SplitUrl *su, Url *u)
729 {
730 if(su->fragment.s == nil)
731 return 0;
732 u->fragment = estredup(su->fragment.s, su->fragment.e);
733 if(!ismatch(REfragment, u->fragment, "fragment"))
734 return -1;
735 return 0;
736 }
737
738 static int
postparse_http(Url * u)739 postparse_http(Url *u)
740 {
741 u->open = httpopen;
742 u->read = httpread;
743 u->close = httpclose;
744
745 if(u->authority==nil){
746 werrstr("missing authority (hostname, port, etc.)");
747 return -1;
748 }
749 if(u->host == nil){
750 werrstr("missing host specification");
751 return -1;
752 }
753
754 if(u->path == nil){
755 u->http.page_spec = estrdup("/");
756 return 0;
757 }
758
759 if(!ismatch(REhttppath, u->path, "http path"))
760 return -1;
761 if(u->query){
762 u->http.page_spec = emalloc(strlen(u->path)+1+strlen(u->query)+1);
763 strcpy(u->http.page_spec, u->path);
764 strcat(u->http.page_spec, "?");
765 strcat(u->http.page_spec, u->query);
766 }else
767 u->http.page_spec = estrdup(u->path);
768
769 return 0;
770 }
771
772 static int
postparse_ftp(Url * u)773 postparse_ftp(Url *u)
774 {
775 Resub m[MaxResub];
776 Retab *t;
777
778 if(u->authority==nil){
779 werrstr("missing authority (hostname, port, etc.)");
780 return -1;
781 }
782 if(u->query){
783 werrstr("unexpected \"?query\" in ftp path");
784 return -1;
785 }
786 if(u->host == nil){
787 werrstr("missing host specification");
788 return -1;
789 }
790
791 if(u->path == nil){
792 u->ftp.path_spec = estrdup("/");
793 return 0;
794 }
795
796 m[0].sp = m[0].ep = nil;
797 t = &retab[REftppath];
798 if(!regx(t->prog, u->path, m, t->size)){
799 werrstr("malformed ftp path: %q", u->path);
800 return -1;
801 }
802
803 if(m[t->ind[0]].sp){
804 u->ftp.path_spec = estredup(m[t->ind[0]].sp, m[t->ind[0]].ep);
805 if(strchr(u->ftp.path_spec, ';')){
806 werrstr("unexpected \";param\" in ftp path");
807 return -1;
808 }
809 }else
810 u->ftp.path_spec = estrdup("/");
811
812 if(m[t->ind[1]].sp){
813 u->ftp.type = estredup(m[t->ind[1]].sp, m[t->ind[1]].ep);
814 strlower(u->ftp.type);
815 }
816 return 0;
817 }
818
819 static int
postparse_file(Url * u)820 postparse_file(Url *u)
821 {
822 if(u->user || u->passwd){
823 werrstr("user information not valid with file scheme");
824 return -1;
825 }
826 if(u->query){
827 werrstr("unexpected \"?query\" in file path");
828 return -1;
829 }
830 if(u->port){
831 werrstr("port not valid with file scheme");
832 return -1;
833 }
834 if(u->path == nil){
835 werrstr("missing path in file scheme");
836 return -1;
837 }
838 if(strchr(u->path, ';')){
839 werrstr("unexpected \";param\" in file path");
840 return -1;
841 }
842
843 if(!ismatch(REfilepath, u->path, "file path"))
844 return -1;
845
846 /* "localhost" is equivalent to no host spec, we'll chose the latter */
847 if(u->host && cistrcmp(u->host, "localhost") == 0){
848 free(u->host);
849 u->host = nil;
850 }
851 return 0;
852 }
853
854 static int (*postparse[])(Url*) = {
855 nil,
856 postparse_http,
857 postparse_http,
858 postparse_ftp,
859 postparse_file,
860 };
861
862 Url*
parseurl(char * url,Url * base)863 parseurl(char *url, Url *base)
864 {
865 Url *u;
866 SplitUrl su;
867
868 if(urldebug)
869 fprint(2, "parseurl %s with base %s\n", url, base ? base->url : "<none>");
870
871 u = emalloc(sizeof(Url));
872 u->url = estrdup(url);
873 if(spliturl(u->url, &su) < 0){
874 Fail:
875 freeurl(u);
876 return nil;
877 }
878
879 /* RFC2396 sec 3.1 says relative URIs are distinguished by absent scheme */
880 if(su.scheme.s==nil){
881 if(urldebug)
882 fprint(2, "parseurl has nil scheme\n");
883 if(resolve_relative(&su, base, u) < 0 || spliturl(u->url, &su) < 0)
884 goto Fail;
885 if(u->ischeme == UScurrent){
886 /* 'u.url' refers to current document; set fragment and return */
887 if(parse_fragment(&su, u) < 0)
888 goto Fail;
889 return u;
890 }
891 }
892
893 if(parse_scheme(&su, u) < 0
894 || parse_fragment(&su, u) < 0)
895 goto Fail;
896
897 if(u->ischeme == USunknown){
898 if(parse_unknown_part(&su, u) < 0)
899 goto Fail;
900 return u;
901 }
902
903 if(parse_query(&su, u) < 0
904 || parse_authority(&su, u) < 0
905 || parse_abspath(&su, u) < 0)
906 goto Fail;
907
908 if(u->ischeme < nelem(postparse) && postparse[u->ischeme])
909 if((*postparse[u->ischeme])(u) < 0)
910 goto Fail;
911
912 setmalloctag(u, getcallerpc(&url));
913 return u;
914 }
915
916 void
freeurl(Url * u)917 freeurl(Url *u)
918 {
919 if(u == nil)
920 return;
921 free(u->url);
922 free(u->scheme);
923 free(u->schemedata);
924 free(u->authority);
925 free(u->user);
926 free(u->passwd);
927 free(u->host);
928 free(u->port);
929 free(u->path);
930 free(u->query);
931 free(u->fragment);
932 switch(u->ischeme){
933 case UShttp:
934 free(u->http.page_spec);
935 break;
936 case USftp:
937 free(u->ftp.path_spec);
938 free(u->ftp.type);
939 break;
940 }
941 free(u);
942 }
943
944 void
rewriteurl(Url * u)945 rewriteurl(Url *u)
946 {
947 char *s;
948
949 if(u->schemedata)
950 s = estrmanydup(u->scheme, ":", u->schemedata, nil);
951 else
952 s = estrmanydup(u->scheme, "://",
953 u->user ? u->user : "",
954 u->passwd ? ":" : "", u->passwd ? u->passwd : "",
955 u->user ? "@" : "", u->host ? u->host : "",
956 u->port ? ":" : "", u->port ? u->port : "",
957 u->path,
958 u->query ? "?" : "", u->query ? u->query : "",
959 u->fragment ? "#" : "", u->fragment ? u->fragment : "",
960 nil);
961 free(u->url);
962 u->url = s;
963 }
964
965 int
seturlquery(Url * u,char * query)966 seturlquery(Url *u, char *query)
967 {
968 if(query == nil){
969 free(u->query);
970 u->query = nil;
971 return 0;
972 }
973
974 if(!ismatch(REquery, query, "query"))
975 return -1;
976
977 free(u->query);
978 u->query = estrdup(query);
979 return 0;
980 }
981
982 static void
dupp(char ** p)983 dupp(char **p)
984 {
985 if(*p)
986 *p = estrdup(*p);
987 }
988
989 Url*
copyurl(Url * u)990 copyurl(Url *u)
991 {
992 Url *v;
993
994 v = emalloc(sizeof(Url));
995 *v = *u;
996 dupp(&v->url);
997 dupp(&v->scheme);
998 dupp(&v->schemedata);
999 dupp(&v->authority);
1000 dupp(&v->user);
1001 dupp(&v->passwd);
1002 dupp(&v->host);
1003 dupp(&v->port);
1004 dupp(&v->path);
1005 dupp(&v->query);
1006 dupp(&v->fragment);
1007
1008 switch(v->ischeme){
1009 case UShttp:
1010 dupp(&v->http.page_spec);
1011 break;
1012 case USftp:
1013 dupp(&v->ftp.path_spec);
1014 dupp(&v->ftp.type);
1015 break;
1016 }
1017 return v;
1018 }
1019
1020 static int
dhex(char c)1021 dhex(char c)
1022 {
1023 if('0' <= c && c <= '9')
1024 return c-'0';
1025 if('a' <= c && c <= 'f')
1026 return c-'a'+10;
1027 if('A' <= c && c <= 'F')
1028 return c-'A'+10;
1029 return 0;
1030 }
1031
1032 char*
escapeurl(char * s,int (* needesc)(int))1033 escapeurl(char *s, int (*needesc)(int))
1034 {
1035 int n;
1036 char *t, *u;
1037 Rune r;
1038 static char *hex = "0123456789abcdef";
1039
1040 n = 0;
1041 for(t=s; *t; t++)
1042 if((*needesc)(*t))
1043 n++;
1044
1045 u = emalloc(strlen(s)+2*n+1);
1046 t = u;
1047 for(; *s; s++){
1048 s += chartorune(&r, s);
1049 if(r >= 0xFF){
1050 werrstr("URLs cannot contain Runes > 0xFF");
1051 free(t);
1052 return nil;
1053 }
1054 if((*needesc)(r)){
1055 *u++ = '%';
1056 *u++ = hex[(r>>4)&0xF];
1057 *u++ = hex[r&0xF];
1058 }else
1059 *u++ = r;
1060 }
1061 *u = '\0';
1062 return t;
1063 }
1064
1065 char*
unescapeurl(char * s)1066 unescapeurl(char *s)
1067 {
1068 char *r, *w;
1069 Rune rune;
1070
1071 s = estrdup(s);
1072 for(r=w=s; *r; r++){
1073 if(*r=='%'){
1074 r++;
1075 if(!isxdigit(r[0]) || !isxdigit(r[1])){
1076 werrstr("bad escape sequence '%.3s' in URL", r);
1077 return nil;
1078 }
1079 if(r[0]=='0' && r[2]=='0'){
1080 werrstr("escaped NUL in URL");
1081 return nil;
1082 }
1083 rune = (dhex(r[0])<<4)|dhex(r[1]); /* latin1 */
1084 w += runetochar(w, &rune);
1085 r += 2;
1086 }else
1087 *w++ = *r;
1088 }
1089 *w = '\0';
1090 return s;
1091 }
1092
1093