Annotation of libwww/Library/src/HTParse.c, revision 2.67
2.41 frystyk 1: /* HTParse.c
2: ** URI MANAGEMENT
3: **
2.46 frystyk 4: ** (c) COPYRIGHT MIT 1995.
2.41 frystyk 5: ** Please first read the full copyright statement in the file COPYRIGH.
2.67 ! frystyk 6: ** @(#) $Id: HTParse.c,v 2.66 1996/06/28 16:31:19 frystyk Exp $
2.26 frystyk 7: **
8: ** history:
9: ** May 12 94 TAB added as legal char in HTCleanTelnetString
10: **
1.1 timbl 11: */
2.31 frystyk 12:
2.44 frystyk 13: /* Library include files */
2.63 frystyk 14: #include "sysdep.h"
2.65 frystyk 15: #include "WWWUtil.h"
2.44 frystyk 16: #include "HTString.h"
2.65 frystyk 17: #include "HTParse.h" /* Implemented here */
2.6 timbl 18:
2.66 frystyk 19: typedef struct _HTURI {
20: char * access; /* Now known as "scheme" */
21: char * host;
22: char * absolute;
23: char * relative;
24: char * fragment;
25: } HTURI;
1.1 timbl 26:
27: /* Scan a filename for its consituents
28: ** -----------------------------------
29: **
30: ** On entry,
31: ** name points to a document name which may be incomplete.
32: ** On exit,
33: ** absolute or relative may be nonzero (but not both).
2.66 frystyk 34: ** host, fragment and access may be nonzero if they were specified.
1.1 timbl 35: ** Any which are nonzero point to zero terminated strings.
36: */
2.66 frystyk 37: PRIVATE void scan (char * name, HTURI * parts)
1.1 timbl 38: {
39: char * p;
2.66 frystyk 40: char * after_access = name;
41: memset(parts, '\0', sizeof(HTURI));
42:
43: /* Look for fragment identifier */
44: if ((p = strrchr(name, '#')) != NULL) {
45: *p++ = '\0';
46: parts->fragment = p;
47: }
1.1 timbl 48:
49: for(p=name; *p; p++) {
2.66 frystyk 50: if (*p=='/' || *p=='#' || *p=='?')
51: break;
1.1 timbl 52: if (*p==':') {
53: *p = 0;
2.20 timbl 54: parts->access = after_access; /* Scheme has been specified */
2.37 howcome 55:
2.44 frystyk 56: /* The combination of gcc, the "-O" flag and the HP platform is
57: unhealthy. The following three lines is a quick & dirty fix, but is
58: not recommended. Rather, turn off "-O". */
59:
2.42 howcome 60: /* after_access = p;*/
2.44 frystyk 61: /* while (*after_access == 0)*/
62: /* after_access++;*/
2.42 howcome 63:
1.1 timbl 64: after_access = p+1;
2.37 howcome 65:
2.22 luotonen 66: if (0==strcasecomp("URL", parts->access)) {
2.20 timbl 67: parts->access = NULL; /* Ignore IETF's URL: pre-prefix */
68: } else break;
1.1 timbl 69: }
70: }
71:
72: p = after_access;
73: if (*p=='/'){
74: if (p[1]=='/') {
75: parts->host = p+2; /* host has been specified */
76: *p=0; /* Terminate access */
77: p=strchr(parts->host,'/'); /* look for end of host name if any */
78: if(p) {
79: *p=0; /* Terminate host */
80: parts->absolute = p+1; /* Root has been found */
81: }
82: } else {
83: parts->absolute = p+1; /* Root found but no host */
84: }
85: } else {
2.49 frystyk 86: parts->relative = (*after_access) ? after_access : 0; /* zero for "" */
1.1 timbl 87: }
2.50 frystyk 88: }
1.1 timbl 89:
90:
91: /* Parse a Name relative to another name
92: ** -------------------------------------
93: **
94: ** This returns those parts of a name which are given (and requested)
95: ** substituting bits from the related name where necessary.
96: **
97: ** On entry,
98: ** aName A filename given
2.33 howcome 99: ** relatedName A name relative to which aName is to be parsed. Give
100: ** it an empty string if aName is absolute.
1.1 timbl 101: ** wanted A mask for the bits which are wanted.
102: **
103: ** On exit,
104: ** returns A pointer to a malloc'd string which MUST BE FREED
105: */
2.63 frystyk 106: PUBLIC char * HTParse (const char *aName, const char *relatedName, int wanted)
1.1 timbl 107: {
108: char * result = 0;
109: char * return_value = 0;
110: int len;
111: char * name = 0;
112: char * rel = 0;
113: char * p;
2.12 timbl 114: char * access;
2.66 frystyk 115: HTURI given, related;
2.33 howcome 116:
117: if (!relatedName) /* HWL 23/8/94: dont dump due to NULL */
118: relatedName = "";
1.1 timbl 119:
2.50 frystyk 120: /* Make working copies of input strings to cut up: */
1.1 timbl 121: len = strlen(aName)+strlen(relatedName)+10;
2.61 frystyk 122: if ((result=(char *) HT_MALLOC(len)) == NULL) /* Lots of space: more than enough */
123: HT_OUTOFMEM("parse space");
1.1 timbl 124: StrAllocCopy(name, aName);
125: StrAllocCopy(rel, relatedName);
126:
127: scan(name, &given);
128: scan(rel, &related);
129: result[0]=0; /* Clear string */
2.12 timbl 130: access = given.access ? given.access : related.access;
1.1 timbl 131: if (wanted & PARSE_ACCESS)
2.12 timbl 132: if (access) {
133: strcat(result, access);
1.1 timbl 134: if(wanted & PARSE_PUNCTUATION) strcat(result, ":");
135: }
136:
137: if (given.access && related.access) /* If different, inherit nothing. */
138: if (strcmp(given.access, related.access)!=0) {
139: related.host=0;
140: related.absolute=0;
141: related.relative=0;
2.66 frystyk 142: related.fragment=0;
1.1 timbl 143: }
144:
145: if (wanted & PARSE_HOST)
146: if(given.host || related.host) {
147: if(wanted & PARSE_PUNCTUATION) strcat(result, "//");
148: strcat(result, given.host ? given.host : related.host);
149: }
150:
151: if (given.host && related.host) /* If different hosts, inherit no path. */
152: if (strcmp(given.host, related.host)!=0) {
153: related.absolute=0;
154: related.relative=0;
2.66 frystyk 155: related.fragment=0;
1.1 timbl 156: }
157:
158: if (wanted & PARSE_PATH) {
159: if(given.absolute) { /* All is given */
160: if(wanted & PARSE_PUNCTUATION) strcat(result, "/");
161: strcat(result, given.absolute);
162: } else if(related.absolute) { /* Adopt path not name */
163: strcat(result, "/");
164: strcat(result, related.absolute);
165: if (given.relative) {
166: p = strchr(result, '?'); /* Search part? */
167: if (!p) p=result+strlen(result)-1;
168: for (; *p!='/'; p--); /* last / */
169: p[1]=0; /* Remove filename */
170: strcat(result, given.relative); /* Add given one */
2.55 frystyk 171: #if 0
2.45 frystyk 172: result = HTSimplify (&result);
2.55 frystyk 173: #endif
1.1 timbl 174: }
175: } else if(given.relative) {
176: strcat(result, given.relative); /* what we've got */
177: } else if(related.relative) {
178: strcat(result, related.relative);
179: } else { /* No inheritance */
180: strcat(result, "/");
181: }
182: }
183:
184: if (wanted & PARSE_ANCHOR)
2.66 frystyk 185: if(given.fragment || related.fragment) {
186: if(given.absolute && given.fragment) { /*Fixes for relURLs...*/
2.58 neon 187: if(wanted & PARSE_PUNCTUATION) strcat(result, "#");
2.66 frystyk 188: strcat(result, given.fragment);
189: } else if (!(given.absolute) && !(given.fragment)) {
2.58 neon 190: strcat(result, "");
191: } else {
192: if(wanted & PARSE_PUNCTUATION) strcat(result, "#");
2.66 frystyk 193: strcat(result, given.fragment ? given.fragment : related.fragment);
2.58 neon 194: }
1.1 timbl 195: }
2.61 frystyk 196: HT_FREE(rel);
197: HT_FREE(name);
1.1 timbl 198:
199: StrAllocCopy(return_value, result);
2.61 frystyk 200: HT_FREE(result);
1.1 timbl 201: return return_value; /* exactly the right length */
202: }
2.21 frystyk 203:
2.20 timbl 204:
2.65 frystyk 205: /*
2.53 frystyk 206: ** Canonicalizes the URL in the following manner starting from the host
207: ** pointer:
208: **
209: ** 1) The host name is converted to lowercase
2.65 frystyk 210: ** 2) Chop off port if `:80' (http), `:70' (gopher), or `:21' (ftp)
2.53 frystyk 211: **
212: ** Return: OK The position of the current path part of the URL
213: ** which might be the old one or a new one.
214: */
2.65 frystyk 215: PRIVATE char * HTCanon (char ** filename, char * host)
2.53 frystyk 216: {
217: char *newname = NULL;
218: char *port;
219: char *strptr;
220: char *path;
221: char *access = host-3;
222:
223: while (access>*filename && *(access-1)!='/') /* Find access method */
224: access--;
225: if ((path = strchr(host, '/')) == NULL) /* Find path */
226: path = host + strlen(host);
227: if ((strptr = strchr(host, '@')) != NULL && strptr<path) /* UserId */
228: host = strptr;
229: if ((port = strchr(host, ':')) != NULL && port>path) /* Port number */
230: port = NULL;
231:
232: strptr = host; /* Convert to lower-case */
233: while (strptr<path) {
234: *strptr = TOLOWER(*strptr);
235: strptr++;
236: }
237:
238: /* Does the URL contain a full domain name? This also works for a
239: numerical host name. The domain name is already made lower-case
240: and without a trailing dot. */
2.65 frystyk 241: #if 0
2.53 frystyk 242: if (((strptr = strchr(host, '.')) == NULL || strptr >= path) &&
243: strncasecomp(host, "localhost", 9)) {
2.63 frystyk 244: const char *domain = HTGetDomainName();
2.53 frystyk 245: if (domain && *domain) {
2.61 frystyk 246: if ((newname = (char *) HT_CALLOC(1, strlen(*filename) + strlen(domain)+2)) == NULL)
247: HT_OUTOFMEM("HTCanon");
2.53 frystyk 248: if (port)
249: strncpy(newname, *filename, (int) (port-*filename));
250: else
251: strncpy(newname, *filename, (int) (path-*filename));
252: strcat(newname, ".");
253: strcat(newname, domain);
254: }
2.65 frystyk 255: } else /* Look for a trailing dot */
256: #endif
257: {
2.53 frystyk 258: char *dot = port ? port : path;
259: if (dot > *filename && *--dot=='.') {
260: char *orig=dot, *dest=dot+1;
261: while((*orig++ = *dest++));
262: if (port) port--;
263: path--;
264: }
265: }
266: /* Chop off port if `:', `:80' (http), `:70' (gopher), or `:21' (ftp) */
267: if (port) {
268: if (!*(port+1) || *(port+1)=='/') {
269: if (!newname) {
270: char *orig=port, *dest=port+1;
271: while((*orig++ = *dest++));
272: }
273: } else if ((!strncmp(access, "http", 4) &&
274: (*(port+1)=='8'&&*(port+2)=='0'&&(*(port+3)=='/'||!*(port+3)))) ||
275: (!strncmp(access, "gopher", 6) &&
276: (*(port+1)=='7'&&*(port+2)=='0'&&(*(port+3)=='/'||!*(port+3)))) ||
277: (!strncmp(access, "ftp", 3) &&
278: (*(port+1)=='2'&&*(port+2)=='1'&&(*(port+3)=='/'||!*(port+3))))) {
279: if (!newname) {
280: char *orig=port, *dest=port+3;
281: while((*orig++ = *dest++));
2.54 frystyk 282: path -= 3; /* Update path position, Henry Minsky */
2.53 frystyk 283: }
284: } else if (newname)
285: strncat(newname, port, (int) (path-port));
286: }
287:
288: if (newname) {
289: char *newpath = newname+strlen(newname);
290: strcat(newname, path);
291: path = newpath;
2.61 frystyk 292: HT_FREE(*filename); /* Free old copy */
2.53 frystyk 293: *filename = newname;
294: }
295: return path;
2.67 ! frystyk 296: }
! 297:
! 298: /*
! 299: ** Search the URL and determine whether it is a relative or absolute URL.
! 300: ** We check to see if there is a ":" before any "/", "?", and "#". If this
! 301: ** is the case then we say it is absolute. Otherwise it is relative.
! 302: */
! 303: PUBLIC BOOL HTURL_isAbsolute (const char * url)
! 304: {
! 305: if (url) {
! 306: const char * ptr = url;
! 307: while (*ptr) {
! 308: if (*ptr == ':') return YES;
! 309: if (*ptr == '/' || *ptr == '?' || *ptr == '#') break;
! 310: ptr ++;
! 311: }
! 312: }
! 313: return NO;
2.53 frystyk 314: }
315:
2.20 timbl 316: /* Simplify a URI
317: // --------------
318: // A URI is allowed to contain the seqeunce xxx/../ which may be
1.1 timbl 319: // replaced by "" , and the seqeunce "/./" which may be replaced by "/".
2.20 timbl 320: // Simplification helps us recognize duplicate URIs.
1.1 timbl 321: //
322: // Thus, /etc/junk/../fred becomes /etc/fred
323: // /etc/junk/./fred becomes /etc/junk/fred
2.11 timbl 324: //
325: // but we should NOT change
326: // http://fred.xxx.edu/../..
327: //
328: // or ../../albert.html
2.26 frystyk 329: //
330: // In order to avoid empty URLs the following URLs become:
331: //
332: // /fred/.. becomes /fred/..
333: // /fred/././.. becomes /fred/..
2.27 frystyk 334: // /fred/.././junk/.././ becomes /fred/..
2.26 frystyk 335: //
2.30 frystyk 336: // If more than one set of `://' is found (several proxies in cascade) then
337: // only the part after the last `://' is simplified.
2.44 frystyk 338: //
339: // Returns: A string which might be the old one or a new one.
1.1 timbl 340: */
2.60 frystyk 341: PUBLIC char *HTSimplify (char ** url)
1.1 timbl 342: {
2.31 frystyk 343: char *path;
344: char *p;
2.55 frystyk 345: if (!url || !*url) {
2.62 eric 346: if (URI_TRACE) HTTrace("HTSimplify.. Nothing done\n");
2.55 frystyk 347: return *url;
2.31 frystyk 348: }
2.62 eric 349: if (URI_TRACE) HTTrace("HTSimplify.. `%s\' ", *url);
2.27 frystyk 350:
2.55 frystyk 351: /* Find any scheme name */
352: if ((path = strstr(*url, "://")) != NULL) { /* Find host name */
2.30 frystyk 353: char *newptr;
2.60 frystyk 354: char *access = *url;
355: while (access<path && (*access=TOLOWER(*access))) access++;
2.31 frystyk 356: path += 3;
2.60 frystyk 357: while ((newptr = strstr(path, "://")) != NULL) /* For proxies */
2.31 frystyk 358: path = newptr+3;
2.55 frystyk 359: path = HTCanon(url, path); /* We have a host name */
360: } else if ((path = strstr(*url, ":/")) != NULL) {
2.31 frystyk 361: path += 2;
2.27 frystyk 362: } else
2.55 frystyk 363: path = *url;
2.31 frystyk 364: if (*path == '/' && *(path+1)=='/') { /* Some URLs start //<foo> */
365: path += 1;
2.34 frystyk 366: } else if (!strncmp(path, "news:", 5)) {
367: char *ptr = strchr(path+5, '@');
368: if (!ptr) ptr = path+5;
369: while (*ptr) { /* Make group or host lower case */
370: *ptr = TOLOWER(*ptr);
371: ptr++;
2.31 frystyk 372: }
373: if (URI_TRACE)
2.62 eric 374: HTTrace("into\n............ `%s'\n", *url);
2.55 frystyk 375: return *url; /* Doesn't need to do any more */
2.31 frystyk 376: }
377: if ((p = path)) {
2.55 frystyk 378: char *end;
379: if (!((end = strchr(path, ';')) || (end = strchr(path, '?')) ||
380: (end = strchr(path, '#'))))
381: end = path+strlen(path);
2.31 frystyk 382:
383: /* Parse string second time to simplify */
384: p = path;
2.55 frystyk 385: while(p<end) {
2.31 frystyk 386: if (*p=='/') {
2.56 frystyk 387: if (p>*url && *(p+1)=='.' && (*(p+2)=='/' || !*(p+2))) {
388: char *orig = p+1;
389: char *dest = (*(p+2)!='/') ? p+2 : p+3;
2.31 frystyk 390: while ((*orig++ = *dest++)); /* Remove a slash and a dot */
2.55 frystyk 391: end = orig-1;
2.56 frystyk 392: } else if (*(p+1)=='.' && *(p+2)=='.' && (*(p+3)=='/' || !*(p+3))) {
2.31 frystyk 393: char *q = p;
394: while (q>path && *--q!='/'); /* prev slash */
2.56 frystyk 395: if (strncmp(q, "/../", 4)) {
396: char *orig = q+1;
397: char *dest = (*(p+3)!='/') ? p+3 : p+4;
2.31 frystyk 398: while ((*orig++ = *dest++)); /* Remove /xxx/.. */
2.55 frystyk 399: end = orig-1;
2.56 frystyk 400: p = q; /* Start again with prev slash */
2.31 frystyk 401: } else
402: p++;
403: } else if (*(p+1)=='/') {
404: while (*(p+1)=='/') {
405: char *orig=p, *dest=p+1;
406: while ((*orig++ = *dest++)); /* Remove multiple /'s */
2.55 frystyk 407: end = orig-1;
2.19 frystyk 408: }
2.56 frystyk 409: } else
410: p++;
411: } else
412: p++;
413: }
2.19 frystyk 414: }
2.31 frystyk 415: if (URI_TRACE)
2.62 eric 416: HTTrace("into\n............ `%s'\n", *url);
2.55 frystyk 417: return *url;
2.19 frystyk 418: }
2.31 frystyk 419:
1.1 timbl 420: /* Make Relative Name
421: ** ------------------
422: **
423: ** This function creates and returns a string which gives an expression of
424: ** one address as related to another. Where there is no relation, an absolute
425: ** address is retured.
426: **
427: ** On entry,
428: ** Both names must be absolute, fully qualified names of nodes
2.66 frystyk 429: ** (no fragment bits)
1.1 timbl 430: **
431: ** On exit,
432: ** The return result points to a newly allocated name which, if
433: ** parsed by HTParse relative to relatedName, will yield aName.
434: ** The caller is responsible for freeing the resulting name later.
435: **
436: */
2.63 frystyk 437: PUBLIC char * HTRelative (const char * aName, const char * relatedName)
1.1 timbl 438: {
439: char * result = 0;
2.63 frystyk 440: const char *p = aName;
441: const char *q = relatedName;
442: const char * after_access = 0;
443: const char * path = 0;
444: const char * last_slash = 0;
1.1 timbl 445: int slashes = 0;
446:
447: for(;*p; p++, q++) { /* Find extent of match */
448: if (*p!=*q) break;
449: if (*p==':') after_access = p+1;
450: if (*p=='/') {
451: last_slash = p;
452: slashes++;
453: if (slashes==3) path=p;
454: }
455: }
456:
457: /* q, p point to the first non-matching character or zero */
458:
459: if (!after_access) { /* Different access */
460: StrAllocCopy(result, aName);
461: } else if (slashes<3){ /* Different nodes */
462: StrAllocCopy(result, after_access);
463: } else { /* Some path in common */
464: int levels= 0;
465: for(; *q && (*q!='#'); q++) if (*q=='/') levels++;
2.61 frystyk 466: if ((result = (char *) HT_MALLOC(3*levels + strlen(last_slash) + 1)) == NULL)
467: HT_OUTOFMEM("HTRelative");
1.1 timbl 468: result[0]=0;
469: for(;levels; levels--)strcat(result, "../");
470: strcat(result, last_slash+1);
471: }
2.62 eric 472: if (URI_TRACE) HTTrace(
2.21 frystyk 473: "HTRelative.. `%s' expressed relative to `%s' is `%s'\n",
474: aName, relatedName, result);
1.1 timbl 475: return result;
476: }
2.1 timbl 477:
2.24 luotonen 478: /* HTCleanTelnetString()
479: * Make sure that the given string doesn't contain characters that
480: * could cause security holes, such as newlines in ftp, gopher,
481: * news or telnet URLs; more specifically: allows everything between
2.26 frystyk 482: * ASCII 20-7E, and also A0-FE, inclusive. Also TAB ('\t') allowed!
2.24 luotonen 483: *
484: * On entry,
485: * str the string that is *modified* if necessary. The
486: * string will be truncated at the first illegal
487: * character that is encountered.
488: * On exit,
489: * returns YES, if the string was modified.
490: * NO, otherwise.
491: */
2.60 frystyk 492: PUBLIC BOOL HTCleanTelnetString (char * str)
2.24 luotonen 493: {
494: char * cur = str;
495:
496: if (!str) return NO;
497:
498: while (*cur) {
2.52 frystyk 499: int a = TOASCII((unsigned char) *cur);
2.26 frystyk 500: if (a != 0x9 && (a < 0x20 || (a > 0x7E && a < 0xA0) || a > 0xFE)) {
2.31 frystyk 501: if (URI_TRACE)
2.62 eric 502: HTTrace("Illegal..... character in URL: \"%s\"\n",str);
2.24 luotonen 503: *cur = 0;
2.31 frystyk 504: if (URI_TRACE)
2.62 eric 505: HTTrace("Truncated... \"%s\"\n",str);
2.24 luotonen 506: return YES;
507: }
508: cur++;
509: }
510: return NO;
511: }
512:
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