Annotation of libwww/Library/src/HTParse.c, revision 2.30

1.1       timbl       1: /*             Parse HyperText Document Address                HTParse.c
                      2: **             ================================
2.26      frystyk     3: **
                      4: ** history:
                      5: **     May 12 94       TAB added as legal char in HTCleanTelnetString
                      6: **
1.1       timbl       7: */
2.27      frystyk     8: #include "tcp.h"
1.1       timbl       9: #include "HTUtils.h"
                     10: #include "HTParse.h"
                     11: 
2.6       timbl      12: #define HEX_ESCAPE '%'
                     13: 
1.1       timbl      14: struct struct_parts {
2.20      timbl      15:        char * access;          /* Now known as "scheme" */
1.1       timbl      16:        char * host;
                     17:        char * absolute;
                     18:        char * relative;
                     19: /*     char * search;          no - treated as part of path */
                     20:        char * anchor;
                     21: };
                     22: 
                     23: /*     Strip white space off a string
                     24: **     ------------------------------
                     25: **
                     26: ** On exit,
                     27: **     Return value points to first non-white character, or to 0 if none.
                     28: **     All trailing white space is OVERWRITTEN with zero.
                     29: */
                     30: 
2.13      luotonen   31: PUBLIC char * HTStrip ARGS1(char *, s)
1.1       timbl      32: {
                     33: #define SPACE(c) ((c==' ')||(c=='\t')||(c=='\n')) 
                     34:     char * p=s;
2.13      luotonen   35:     if (!s) return NULL;       /* Doesn't dump core if NULL */
                     36:     for(p=s;*p;p++);           /* Find end of string */
1.1       timbl      37:     for(p--;p>=s;p--) {
                     38:        if(SPACE(*p)) *p=0;     /* Zap trailing blanks */
                     39:        else break;
                     40:     }
                     41:     while(SPACE(*s))s++;       /* Strip leading blanks */
                     42:     return s;
                     43: }
                     44: 
                     45: 
                     46: /*     Scan a filename for its consituents
                     47: **     -----------------------------------
                     48: **
                     49: ** On entry,
                     50: **     name    points to a document name which may be incomplete.
                     51: ** On exit,
                     52: **      absolute or relative may be nonzero (but not both).
                     53: **     host, anchor and access may be nonzero if they were specified.
                     54: **     Any which are nonzero point to zero terminated strings.
                     55: */
                     56: #ifdef __STDC__
                     57: PRIVATE void scan(char * name, struct struct_parts *parts)
                     58: #else
                     59: PRIVATE void scan(name, parts)
                     60:     char * name;
                     61:     struct struct_parts *parts;
                     62: #endif
                     63: {
                     64:     char * after_access;
                     65:     char * p;
                     66:     int length = strlen(name);
                     67:     
                     68:     parts->access = 0;
                     69:     parts->host = 0;
                     70:     parts->absolute = 0;
                     71:     parts->relative = 0;
                     72:     parts->anchor = 0;
                     73:     
                     74:     after_access = name;
                     75:     for(p=name; *p; p++) {
                     76:        if (*p==':') {
                     77:                *p = 0;
2.20      timbl      78:                parts->access = after_access; /* Scheme has been specified */
1.1       timbl      79:                after_access = p+1;
2.22      luotonen   80:                if (0==strcasecomp("URL", parts->access)) {
2.20      timbl      81:                    parts->access = NULL;  /* Ignore IETF's URL: pre-prefix */
                     82:                } else break;
1.1       timbl      83:        }
2.20      timbl      84:        if (*p=='/') break;             /* Access has not been specified */
1.1       timbl      85:        if (*p=='#') break;
                     86:     }
                     87:     
                     88:     for(p=name+length-1; p>=name; p--) {
                     89:        if (*p =='#') {
                     90:            parts->anchor=p+1;
                     91:            *p=0;                               /* terminate the rest */
                     92:        }
                     93:     }
                     94:     p = after_access;
                     95:     if (*p=='/'){
                     96:        if (p[1]=='/') {
                     97:            parts->host = p+2;          /* host has been specified      */
                     98:            *p=0;                       /* Terminate access             */
                     99:            p=strchr(parts->host,'/');  /* look for end of host name if any */
                    100:            if(p) {
                    101:                *p=0;                   /* Terminate host */
                    102:                parts->absolute = p+1;          /* Root has been found */
                    103:            }
                    104:        } else {
                    105:            parts->absolute = p+1;              /* Root found but no host */
                    106:        }           
                    107:     } else {
                    108:         parts->relative = (*after_access) ? after_access : 0;  /* zero for "" */
                    109:     }
                    110: 
2.16      timbl     111: #ifdef OLD_CODE
1.1       timbl     112:     /* Access specified but no host: the anchor was not really one
2.16      timbl     113:        e.g. news:j462#36487@foo.bar -- JFG 10/jul/92, from bug report */
                    114:     /* This kludge doesn't work for example when coming across
                    115:        file:/usr/local/www/fred#123
                    116:        which loses its anchor. Correct approach in news is to
                    117:        escape weird characters not allowed in URL.  TBL 21/dec/93
                    118:     */
1.1       timbl     119:     if (parts->access && ! parts->host && parts->anchor) {
                    120:       *(parts->anchor - 1) = '#';  /* Restore the '#' in the address */
                    121:       parts->anchor = 0;
                    122:     }
2.16      timbl     123: #endif
1.1       timbl     124: 
                    125: #ifdef NOT_DEFINED     /* search is just treated as part of path */
                    126:     {
                    127:         char *p = relative ? relative : absolute;
                    128:        if (p) {
                    129:            char * q = strchr(p, '?');  /* Any search string? */
                    130:            if (q) {
                    131:                *q = 0;                 /* If so, chop that off. */
                    132:                parts->search = q+1;
                    133:            }
                    134:        }
                    135:     }
                    136: #endif
                    137: } /*scan */    
                    138: 
                    139: 
                    140: /*     Parse a Name relative to another name
                    141: **     -------------------------------------
                    142: **
                    143: **     This returns those parts of a name which are given (and requested)
                    144: **     substituting bits from the related name where necessary.
                    145: **
                    146: ** On entry,
                    147: **     aName           A filename given
                    148: **      relatedName     A name relative to which aName is to be parsed
                    149: **      wanted          A mask for the bits which are wanted.
                    150: **
                    151: ** On exit,
                    152: **     returns         A pointer to a malloc'd string which MUST BE FREED
                    153: */
                    154: #ifdef __STDC__
                    155: char * HTParse(const char * aName, const char * relatedName, int wanted)
                    156: #else
                    157: char * HTParse(aName, relatedName, wanted)
                    158:     char * aName;
                    159:     char * relatedName;
                    160:     int wanted;
                    161: #endif
                    162: 
                    163: {
                    164:     char * result = 0;
                    165:     char * return_value = 0;
                    166:     int len;
                    167:     char * name = 0;
                    168:     char * rel = 0;
                    169:     char * p;
2.12      timbl     170:     char * access;
1.1       timbl     171:     struct struct_parts given, related;
                    172:     
                    173:     /* Make working copies of input strings to cut up:
                    174:     */
                    175:     len = strlen(aName)+strlen(relatedName)+10;
                    176:     result=(char *)malloc(len);                /* Lots of space: more than enough */
                    177:     if (result == NULL) outofmem(__FILE__, "HTParse");
                    178:     
                    179:     StrAllocCopy(name, aName);
                    180:     StrAllocCopy(rel, relatedName);
                    181:     
                    182:     scan(name, &given);
                    183:     scan(rel,  &related); 
                    184:     result[0]=0;               /* Clear string  */
2.12      timbl     185:     access = given.access ? given.access : related.access;
1.1       timbl     186:     if (wanted & PARSE_ACCESS)
2.12      timbl     187:         if (access) {
                    188:            strcat(result, access);
1.1       timbl     189:            if(wanted & PARSE_PUNCTUATION) strcat(result, ":");
                    190:        }
                    191:        
                    192:     if (given.access && related.access)        /* If different, inherit nothing. */
                    193:         if (strcmp(given.access, related.access)!=0) {
                    194:            related.host=0;
                    195:            related.absolute=0;
                    196:            related.relative=0;
                    197:            related.anchor=0;
                    198:        }
                    199:        
                    200:     if (wanted & PARSE_HOST)
                    201:         if(given.host || related.host) {
2.12      timbl     202:            char * tail = result + strlen(result);
1.1       timbl     203:            if(wanted & PARSE_PUNCTUATION) strcat(result, "//");
                    204:            strcat(result, given.host ? given.host : related.host);
2.12      timbl     205: #define CLEAN_URLS
                    206: #ifdef CLEAN_URLS
                    207:            /* Ignore default port numbers, and trailing dots on FQDNs
                    208:               which will only cause identical adreesses to look different */
                    209:            {
                    210:                char * p;
                    211:                p = strchr(tail, ':');
                    212:                if (p && access) {              /* Port specified */
                    213:                    if (  (   strcmp(access, "http") == 0
                    214:                           && strcmp(p, ":80") == 0 )
                    215:                        ||
                    216:                          (   strcmp(access, "gopher") == 0
                    217:                           && strcmp(p, ":70") == 0 )
                    218:                        )
                    219:                    *p = (char)0;       /* It is the default: ignore it */
                    220:                }
                    221:                if (!p) p = tail + strlen(tail); /* After hostname */
2.21      frystyk   222:                if (*p) {                                 /* Henrik 17/04-94 */
                    223:                    p--;                                /* End of hostname */
                    224:                    if (*p == '.') *p = (char)0; /* chop final . */
                    225:                }
2.12      timbl     226:            }
                    227: #endif
1.1       timbl     228:        }
                    229:        
                    230:     if (given.host && related.host)  /* If different hosts, inherit no path. */
                    231:         if (strcmp(given.host, related.host)!=0) {
                    232:            related.absolute=0;
                    233:            related.relative=0;
                    234:            related.anchor=0;
                    235:        }
                    236:        
                    237:     if (wanted & PARSE_PATH) {
                    238:         if(given.absolute) {                           /* All is given */
                    239:            if(wanted & PARSE_PUNCTUATION) strcat(result, "/");
                    240:            strcat(result, given.absolute);
                    241:        } else if(related.absolute) {   /* Adopt path not name */
                    242:            strcat(result, "/");
                    243:            strcat(result, related.absolute);
                    244:            if (given.relative) {
                    245:                p = strchr(result, '?');        /* Search part? */
                    246:                if (!p) p=result+strlen(result)-1;
                    247:                for (; *p!='/'; p--);   /* last / */
                    248:                p[1]=0;                                 /* Remove filename */
                    249:                strcat(result, given.relative);         /* Add given one */
                    250:                HTSimplify (result);
                    251:            }
                    252:        } else if(given.relative) {
                    253:            strcat(result, given.relative);             /* what we've got */
                    254:        } else if(related.relative) {
                    255:            strcat(result, related.relative);
                    256:        } else {  /* No inheritance */
                    257:            strcat(result, "/");
                    258:        }
                    259:     }
                    260:                
                    261:     if (wanted & PARSE_ANCHOR)
                    262:         if(given.anchor || related.anchor) {
                    263:            if(wanted & PARSE_PUNCTUATION) strcat(result, "#");
                    264:            strcat(result, given.anchor ? given.anchor : related.anchor);
                    265:        }
                    266:     free(rel);
                    267:     free(name);
                    268:     
                    269:     StrAllocCopy(return_value, result);
                    270:     free(result);
                    271:     return return_value;               /* exactly the right length */
                    272: }
                    273: 
2.11      timbl     274: 
2.21      frystyk   275: #if 0  /* NOT USED FOR THE MOMENT */
2.15      luotonen  276: /*
                    277: **     As strcpy() but guaranteed to work correctly
                    278: **     with overlapping parameters.    AL 7 Feb 1994
                    279: */
                    280: PRIVATE void ari_strcpy ARGS2(char *, to,
                    281:                              char *, from)
                    282: {
                    283:     char * tmp;
                    284: 
                    285:     if (!to || !from) return;
                    286: 
                    287:     tmp = (char*)malloc(strlen(from)+1);
                    288:     if (!tmp) outofmem(__FILE__, "my_strcpy");
                    289: 
                    290:     strcpy(tmp, from);
                    291:     strcpy(to, tmp);
                    292:     free(tmp);
                    293: }
2.21      frystyk   294: #endif
                    295: 
2.20      timbl     296: 
                    297: /*             Simplify a URI
                    298: //             --------------
                    299: // A URI is allowed to contain the seqeunce xxx/../ which may be
1.1       timbl     300: // replaced by "" , and the seqeunce "/./" which may be replaced by "/".
2.20      timbl     301: // Simplification helps us recognize duplicate URIs. 
1.1       timbl     302: //
                    303: //     Thus,   /etc/junk/../fred       becomes /etc/fred
                    304: //             /etc/junk/./fred        becomes /etc/junk/fred
2.11      timbl     305: //
                    306: //      but we should NOT change
                    307: //             http://fred.xxx.edu/../..
                    308: //
                    309: //     or      ../../albert.html
2.26      frystyk   310: //
                    311: // In the same manner, the following prefixed are preserved:
                    312: //
                    313: //     ./<etc>
                    314: //     //<etc>
                    315: //
                    316: // In order to avoid empty URLs the following URLs become:
                    317: //
                    318: //             /fred/..                becomes /fred/..
                    319: //             /fred/././..            becomes /fred/..
2.27      frystyk   320: //             /fred/.././junk/.././   becomes /fred/..
2.26      frystyk   321: //
2.30    ! frystyk   322: // If more than one set of `://' is found (several proxies in cascade) then
        !           323: // only the part after the last `://' is simplified.
1.1       timbl     324: */
2.14      luotonen  325: PUBLIC void HTSimplify ARGS1(char *, filename)
1.1       timbl     326: {
2.19      frystyk   327:     int tokcnt = 0;
                    328:     char *strptr;
                    329:     char *urlptr;
2.27      frystyk   330:     BOOL prefix = NO;   /* If prefix == YES then we can delete all segments */
2.19      frystyk   331:     if (!filename || !*filename)                         /* Just to be sure! */
                    332:        return;
                    333: 
2.27      frystyk   334:     if (TRACE)
                    335:        fprintf(stderr, "HTSimplify.. `%s\' ", filename);
                    336: 
2.19      frystyk   337:     /* Skip prefix, starting ./ and starting ///<etc> */
2.27      frystyk   338:     if ((urlptr = strstr(filename, "://")) != NULL) {        /* Find prefix */
2.30    ! frystyk   339:        char *newptr;
2.27      frystyk   340:        urlptr += 3;
2.30    ! frystyk   341:        while ((newptr = strstr(urlptr, "://")) != NULL)
        !           342:            urlptr = newptr+3;
2.27      frystyk   343:        prefix = YES;
                    344:     } else if ((urlptr = strstr(filename, ":/")) != NULL) {
                    345:        urlptr += 2;
                    346:        prefix = YES;
                    347:     } else
                    348:        urlptr = filename;
                    349:     if (*urlptr == '.' && *(urlptr+1) == '/') {          /* Starting ./<etc> */
2.19      frystyk   350:        urlptr += 2;
2.27      frystyk   351:        prefix = YES;
                    352:     } else if (*urlptr == '/') {                /* Some URLs start //<file> */
2.19      frystyk   353:        while (*++urlptr == '/');
2.27      frystyk   354:        prefix = YES;
2.19      frystyk   355:     }
2.27      frystyk   356:     if (!*urlptr) {                                      /* If nothing left */
                    357:        if (TRACE)
                    358:            fprintf(stderr, "No simplification possible\n");
2.19      frystyk   359:        return;
2.27      frystyk   360:     }
2.19      frystyk   361: 
                    362:     /* Now we have the string we want to work with */
                    363:     strptr = urlptr;
                    364:     while (*strptr++) {                        /* Count number of delimiters */
                    365:        if (*strptr == '/')
                    366:            tokcnt++;
                    367:     }
                    368:     {
                    369:        BOOL slashtail = NO;
2.27      frystyk   370:        int segcnt = 0;      /* Number of 'real segments' (not '.' and '..') */
2.19      frystyk   371:        char *empty = "";
                    372:        char *url = NULL;
                    373:        char **tokptr;
                    374:        char **tokstart;
                    375:        StrAllocCopy(url, urlptr);
                    376: 
                    377:        /* Does the URL end with a slash? */
                    378:        if(*(filename+strlen(filename)-1) == '/')
                    379:            slashtail = YES;
                    380:        
                    381:        /* I allocate cnt+2 as I don't know if the url is terminated by '/' */
                    382:        if ((tokstart = (char **) calloc(tokcnt+2, sizeof(char *))) == NULL)
                    383:            outofmem(__FILE__, "HTSimplify");
                    384: 
2.27      frystyk   385:        /* Read the tokens forwards and count `real' segments */
2.19      frystyk   386:        tokptr = tokstart;
2.27      frystyk   387:        *tokptr = strtok(url, "/");
                    388:        if (strcmp(*tokptr, ".") && strcmp(*tokptr, ".."))
                    389:            segcnt++;
                    390:        tokptr++;
                    391:        while ((strptr = strtok(NULL, "/")) != NULL) {
                    392:            if (strcmp(strptr, ".") && strcmp(strptr, ".."))
                    393:                segcnt++;
                    394:            else if (!strcmp(strptr, "..") && !segcnt)
                    395:                prefix = YES;
2.19      frystyk   396:            *tokptr++ = strptr;
2.27      frystyk   397:        }
                    398: 
2.19      frystyk   399:        /* Scan backwards for '.' and '..' */
                    400:        tokptr--;
                    401:        while(tokptr >= tokstart) {
                    402:            if (!strcmp(*tokptr, ".")) {
                    403:                *tokptr = empty;
                    404:            } else if (!strcmp(*tokptr, "..")) {
                    405:                char **pptr = tokptr-1;
                    406:                while (pptr >= tokstart) {
2.26      frystyk   407:                    if (**pptr && strcmp(*pptr, "..") && strcmp(*pptr, ".") &&
2.27      frystyk   408:                        (segcnt > 1 || prefix)) {
2.19      frystyk   409:                        *pptr = empty;
                    410:                        *tokptr = empty;
2.27      frystyk   411:                        segcnt--;
2.19      frystyk   412:                        break;
                    413:                    }
                    414:                    pptr--;
                    415:                }
                    416:            }
                    417:            tokptr--;
                    418:        }
                    419: 
                    420:        /* Write the rest out forwards */
                    421:        *urlptr = '\0';
                    422:        while (*++tokptr) {
                    423:            if (**tokptr) {
2.27      frystyk   424:                if (*urlptr)              /* Don't want two in the beginning */
                    425:                    strcat(urlptr, "/");
2.19      frystyk   426:                strcat(urlptr, *tokptr);
                    427:            }
                    428:        }
2.27      frystyk   429: 
                    430:        if (slashtail == YES && *(urlptr+(int)strlen(urlptr)-1) != '/')
2.19      frystyk   431:            strcat(urlptr, "/");
                    432:        free(url);
                    433:        free(tokstart);
                    434:     }
                    435:     if (TRACE)
2.27      frystyk   436:        fprintf(stderr, "into\n............ `%s'\n", filename);
2.19      frystyk   437: }
                    438: #ifdef OLD_CODE
2.17      frystyk   439:     char * p = filename;
1.1       timbl     440:     char * q;
2.17      frystyk   441:     
                    442:     if (p) {
                    443:        while (*p && (*p == '/' || *p == '.'))     /* Pass starting / or .'s */
                    444:            p++;
                    445:        while(*p) {
                    446:            if (*p=='/') {
1.1       timbl     447:            if ((p[1]=='.') && (p[2]=='.') && (p[3]=='/' || !p[3] )) {
2.11      timbl     448:                for (q=p-1; (q>=filename) && (*q!='/'); q--); /* prev slash */
                    449:                if (q[0]=='/' && 0!=strncmp(q, "/../", 4)
                    450:                        &&!(q-1>filename && q[-1]=='/')) {
2.15      luotonen  451:                    ari_strcpy(q, p+3);         /* Remove  /xxx/..      */
1.1       timbl     452:                    if (!*filename) strcpy(filename, "/");
                    453:                    p = q-1;            /* Start again with prev slash  */
2.11      timbl     454:                } else {                        /*   xxx/.. leave it!   */
2.9       timbl     455: #ifdef BUG_CODE
2.15      luotonen  456:                    ari_strcpy(filename, p[3] ? p+4 : p+3); /* rm  xxx/../ */
1.1       timbl     457:                    p = filename;               /* Start again */
2.9       timbl     458: #endif
1.1       timbl     459:                }
                    460:            } else if ((p[1]=='.') && (p[2]=='/' || !p[2])) {
2.15      luotonen  461:                ari_strcpy(p, p+2);             /* Remove a slash and a dot */
2.13      luotonen  462:            } else if (p[-1] != ':') {
                    463:                while (p[1] == '/') {
2.15      luotonen  464:                    ari_strcpy(p, p+1); /* Remove multiple slashes */
2.13      luotonen  465:                }
1.1       timbl     466:            }
2.17      frystyk   467:            }
                    468:            p++;
                    469:        }  /* end while (*p) */
                    470:     } /* end if (p) */
1.1       timbl     471: }
2.19      frystyk   472: #endif /* OLD_CODE */
1.1       timbl     473: 
                    474: 
                    475: /*             Make Relative Name
                    476: **             ------------------
                    477: **
                    478: ** This function creates and returns a string which gives an expression of
                    479: ** one address as related to another. Where there is no relation, an absolute
                    480: ** address is retured.
                    481: **
                    482: **  On entry,
                    483: **     Both names must be absolute, fully qualified names of nodes
                    484: **     (no anchor bits)
                    485: **
                    486: **  On exit,
                    487: **     The return result points to a newly allocated name which, if
                    488: **     parsed by HTParse relative to relatedName, will yield aName.
                    489: **     The caller is responsible for freeing the resulting name later.
                    490: **
                    491: */
                    492: #ifdef __STDC__
                    493: char * HTRelative(const char * aName, const char *relatedName)
                    494: #else
                    495: char * HTRelative(aName, relatedName)
                    496:    char * aName;
                    497:    char * relatedName;
                    498: #endif
                    499: {
                    500:     char * result = 0;
                    501:     CONST char *p = aName;
                    502:     CONST char *q = relatedName;
                    503:     CONST char * after_access = 0;
                    504:     CONST char * path = 0;
                    505:     CONST char * last_slash = 0;
                    506:     int slashes = 0;
                    507:     
                    508:     for(;*p; p++, q++) {       /* Find extent of match */
                    509:        if (*p!=*q) break;
                    510:        if (*p==':') after_access = p+1;
                    511:        if (*p=='/') {
                    512:            last_slash = p;
                    513:            slashes++;
                    514:            if (slashes==3) path=p;
                    515:        }
                    516:     }
                    517:     
                    518:     /* q, p point to the first non-matching character or zero */
                    519:     
                    520:     if (!after_access) {                       /* Different access */
                    521:         StrAllocCopy(result, aName);
                    522:     } else if (slashes<3){                     /* Different nodes */
                    523:        StrAllocCopy(result, after_access);
2.29      frystyk   524: #if 0 /* Henrik */
1.1       timbl     525:     } else if (slashes==3){                    /* Same node, different path */
                    526:         StrAllocCopy(result, path);
2.21      frystyk   527: #endif
1.1       timbl     528:     } else {                                   /* Some path in common */
                    529:         int levels= 0;
                    530:         for(; *q && (*q!='#'); q++)  if (*q=='/') levels++;
                    531:        result = (char *)malloc(3*levels + strlen(last_slash) + 1);
                    532:       if (result == NULL) outofmem(__FILE__, "HTRelative");
                    533:        result[0]=0;
                    534:        for(;levels; levels--)strcat(result, "../");
                    535:        strcat(result, last_slash+1);
                    536:     }
2.21      frystyk   537:     if (TRACE) fprintf(stderr,
                    538:                      "HTRelative.. `%s' expressed relative to `%s' is `%s'\n",
                    539:                       aName, relatedName, result);
1.1       timbl     540:     return result;
                    541: }
2.1       timbl     542: 
                    543: 
2.6       timbl     544: /*             Escape undesirable characters using %           HTEscape()
                    545: **             -------------------------------------
                    546: **
                    547: **     This function takes a pointer to a string in which
                    548: **     some characters may be unacceptable unescaped.
                    549: **     It returns a string which has these characters
                    550: **     represented by a '%' character followed by two hex digits.
                    551: **
2.20      timbl     552: **     In the tradition of being conservative in what you do and liberal
                    553: **     in what you accept, we encode some characters which in fact are
                    554: **     allowed in URLs unencoded -- so DON'T use the table below for
                    555: **     parsing! 
                    556: **
2.6       timbl     557: **     Unlike HTUnEscape(), this routine returns a malloced string.
2.20      timbl     558: **
2.6       timbl     559: */
                    560: 
2.20      timbl     561: /* Not BOTH static AND const at the same time in gcc :-(, Henrik 18/03-94 
                    562: **  code gen error in gcc when making random access to
                    563: **  static const table(!!)  */
2.19      frystyk   564: /* PRIVATE CONST unsigned char isAcceptable[96] = */
                    565: PRIVATE unsigned char isAcceptable[96] =
2.6       timbl     566: 
2.20      timbl     567: /* Overencodes */
2.6       timbl     568: /*     Bit 0           xalpha          -- see HTFile.h
                    569: **     Bit 1           xpalpha         -- as xalpha but with plus.
2.20      timbl     570: **     Bit 2 ...       path            -- as xpalpha but with /
2.6       timbl     571: */
                    572:     /*   0 1 2 3 4 5 6 7 8 9 A B C D E F */
                    573:     {    0,0,0,0,0,0,0,0,0,0,7,6,0,7,7,4,      /* 2x   !"#$%&'()*+,-./  */
                    574:          7,7,7,7,7,7,7,7,7,7,0,0,0,0,0,0,      /* 3x  0123456789:;<=>?  */
                    575:         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,       /* 4x  @ABCDEFGHIJKLMNO  */
                    576:         7,7,7,7,7,7,7,7,7,7,7,0,0,0,0,7,       /* 5X  PQRSTUVWXYZ[\]^_  */
                    577:         0,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,       /* 6x  `abcdefghijklmno  */
                    578:         7,7,7,7,7,7,7,7,7,7,7,0,0,0,0,0 };     /* 7X  pqrstuvwxyz{\}~  DEL */
                    579: 
                    580: PRIVATE char *hex = "0123456789ABCDEF";
                    581: 
2.8       timbl     582: PUBLIC char * HTEscape ARGS2 (CONST char *, str,
2.6       timbl     583:        unsigned char, mask)
                    584: {
                    585: #define ACCEPTABLE(a)  ( a>=32 && a<128 && ((isAcceptable[a-32]) & mask))
                    586:     CONST char * p;
                    587:     char * q;
                    588:     char * result;
                    589:     int unacceptable = 0;
                    590:     for(p=str; *p; p++)
                    591:         if (!ACCEPTABLE((unsigned char)TOASCII(*p)))
                    592:                unacceptable++;
                    593:     result = (char *) malloc(p-str + unacceptable+ unacceptable + 1);
                    594:     if (result == NULL) outofmem(__FILE__, "HTEscape");
                    595:     for(q=result, p=str; *p; p++) {
                    596:        unsigned char a = TOASCII(*p);
                    597:        if (!ACCEPTABLE(a)) {
                    598:            *q++ = HEX_ESCAPE;  /* Means hex commming */
                    599:            *q++ = hex[a >> 4];
                    600:            *q++ = hex[a & 15];
                    601:        }
                    602:        else *q++ = *p;
                    603:     }
                    604:     *q++ = 0;                  /* Terminate */
                    605:     return result;
                    606: }
                    607: 
                    608: 
2.1       timbl     609: /*             Decode %xx escaped characters                   HTUnEscape()
                    610: **             -----------------------------
                    611: **
                    612: **     This function takes a pointer to a string in which some
                    613: **     characters may have been encoded in %xy form, where xy is
                    614: **     the acsii hex code for character 16x+y.
                    615: **     The string is converted in place, as it will never grow.
                    616: */
                    617: 
                    618: PRIVATE char from_hex ARGS1(char, c)
                    619: {
2.6       timbl     620:     return  c >= '0' && c <= '9' ?  c - '0' 
                    621:            : c >= 'A' && c <= 'F'? c - 'A' + 10
                    622:            : c - 'a' + 10;     /* accept small letters just in case */
2.1       timbl     623: }
                    624: 
                    625: PUBLIC char * HTUnEscape ARGS1( char *, str)
                    626: {
                    627:     char * p = str;
                    628:     char * q = str;
2.25      frystyk   629: 
                    630:     if (!str) {                                              /* Just for safety ;-) */
                    631:        if (TRACE)
                    632:            fprintf(stderr, "HTUnEscape.. Called with NULL argument.\n");
                    633:        return "";
                    634:     }
2.1       timbl     635:     while(*p) {
2.6       timbl     636:         if (*p == HEX_ESCAPE) {
2.1       timbl     637:            p++;
                    638:            if (*p) *q = from_hex(*p++) * 16;
                    639:            if (*p) *q = FROMASCII(*q + from_hex(*p++));
                    640:            q++;
                    641:        } else {
                    642:            *q++ = *p++; 
                    643:        }
                    644:     }
                    645:     
                    646:     *q++ = 0;
                    647:     return str;
                    648:     
                    649: } /* HTUnEscape */
                    650: 
                    651: 
2.24      luotonen  652: /*                                                     HTCleanTelnetString()
                    653:  *     Make sure that the given string doesn't contain characters that
                    654:  *     could cause security holes, such as newlines in ftp, gopher,
                    655:  *     news or telnet URLs; more specifically: allows everything between
2.26      frystyk   656:  *     ASCII 20-7E, and also A0-FE, inclusive. Also TAB ('\t') allowed!
2.24      luotonen  657:  *
                    658:  * On entry,
                    659:  *     str     the string that is *modified* if necessary.  The
                    660:  *             string will be truncated at the first illegal
                    661:  *             character that is encountered.
                    662:  * On exit,
                    663:  *     returns YES, if the string was modified.
                    664:  *             NO, otherwise.
                    665:  */
                    666: PUBLIC BOOL HTCleanTelnetString ARGS1(char *, str)
                    667: {
                    668:     char * cur = str;
                    669: 
                    670:     if (!str) return NO;
                    671: 
                    672:     while (*cur) {
                    673:        int a = TOASCII(*cur);
2.26      frystyk   674:        if (a != 0x9 && (a < 0x20 || (a > 0x7E && a < 0xA0) ||  a > 0xFE)) {
2.24      luotonen  675:            CTRACE(stderr, "Illegal..... character in URL: \"%s\"\n",str);
                    676:            *cur = 0;
                    677:            CTRACE(stderr, "Truncated... \"%s\"\n",str);
                    678:            return YES;
                    679:        }
                    680:        cur++;
                    681:     }
                    682:     return NO;
                    683: }
                    684: 

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