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