Annotation of libwww/Library/src/HTParse.c, revision 2.31

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: */
2.31    ! frystyk     8: 
1.1       timbl       9: #include "HTUtils.h"
2.31    ! frystyk    10: #include "HTTCP.h"
1.1       timbl      11: #include "HTParse.h"
                     12: 
2.6       timbl      13: #define HEX_ESCAPE '%'
                     14: 
1.1       timbl      15: struct struct_parts {
2.20      timbl      16:        char * access;          /* Now known as "scheme" */
1.1       timbl      17:        char * host;
                     18:        char * absolute;
                     19:        char * relative;
                     20: /*     char * search;          no - treated as part of path */
                     21:        char * anchor;
                     22: };
                     23: 
                     24: /*     Strip white space off a string
                     25: **     ------------------------------
                     26: **
                     27: ** On exit,
                     28: **     Return value points to first non-white character, or to 0 if none.
                     29: **     All trailing white space is OVERWRITTEN with zero.
                     30: */
                     31: 
2.13      luotonen   32: PUBLIC char * HTStrip ARGS1(char *, s)
1.1       timbl      33: {
                     34: #define SPACE(c) ((c==' ')||(c=='\t')||(c=='\n')) 
                     35:     char * p=s;
2.13      luotonen   36:     if (!s) return NULL;       /* Doesn't dump core if NULL */
                     37:     for(p=s;*p;p++);           /* Find end of string */
1.1       timbl      38:     for(p--;p>=s;p--) {
                     39:        if(SPACE(*p)) *p=0;     /* Zap trailing blanks */
                     40:        else break;
                     41:     }
                     42:     while(SPACE(*s))s++;       /* Strip leading blanks */
                     43:     return s;
                     44: }
                     45: 
                     46: 
                     47: /*     Scan a filename for its consituents
                     48: **     -----------------------------------
                     49: **
                     50: ** On entry,
                     51: **     name    points to a document name which may be incomplete.
                     52: ** On exit,
                     53: **      absolute or relative may be nonzero (but not both).
                     54: **     host, anchor and access may be nonzero if they were specified.
                     55: **     Any which are nonzero point to zero terminated strings.
                     56: */
                     57: #ifdef __STDC__
                     58: PRIVATE void scan(char * name, struct struct_parts *parts)
                     59: #else
                     60: PRIVATE void scan(name, parts)
                     61:     char * name;
                     62:     struct struct_parts *parts;
                     63: #endif
                     64: {
                     65:     char * after_access;
                     66:     char * p;
                     67:     int length = strlen(name);
                     68:     
                     69:     parts->access = 0;
                     70:     parts->host = 0;
                     71:     parts->absolute = 0;
                     72:     parts->relative = 0;
                     73:     parts->anchor = 0;
                     74:     
                     75:     after_access = name;
                     76:     for(p=name; *p; p++) {
                     77:        if (*p==':') {
                     78:                *p = 0;
2.20      timbl      79:                parts->access = after_access; /* Scheme has been specified */
1.1       timbl      80:                after_access = p+1;
2.22      luotonen   81:                if (0==strcasecomp("URL", parts->access)) {
2.20      timbl      82:                    parts->access = NULL;  /* Ignore IETF's URL: pre-prefix */
                     83:                } else break;
1.1       timbl      84:        }
2.20      timbl      85:        if (*p=='/') break;             /* Access has not been specified */
1.1       timbl      86:        if (*p=='#') break;
                     87:     }
                     88:     
                     89:     for(p=name+length-1; p>=name; p--) {
                     90:        if (*p =='#') {
                     91:            parts->anchor=p+1;
                     92:            *p=0;                               /* terminate the rest */
                     93:        }
                     94:     }
                     95:     p = after_access;
                     96:     if (*p=='/'){
                     97:        if (p[1]=='/') {
                     98:            parts->host = p+2;          /* host has been specified      */
                     99:            *p=0;                       /* Terminate access             */
                    100:            p=strchr(parts->host,'/');  /* look for end of host name if any */
                    101:            if(p) {
                    102:                *p=0;                   /* Terminate host */
                    103:                parts->absolute = p+1;          /* Root has been found */
                    104:            }
                    105:        } else {
                    106:            parts->absolute = p+1;              /* Root found but no host */
                    107:        }           
                    108:     } else {
                    109:         parts->relative = (*after_access) ? after_access : 0;  /* zero for "" */
                    110:     }
                    111: 
2.16      timbl     112: #ifdef OLD_CODE
1.1       timbl     113:     /* Access specified but no host: the anchor was not really one
2.16      timbl     114:        e.g. news:j462#36487@foo.bar -- JFG 10/jul/92, from bug report */
                    115:     /* This kludge doesn't work for example when coming across
                    116:        file:/usr/local/www/fred#123
                    117:        which loses its anchor. Correct approach in news is to
                    118:        escape weird characters not allowed in URL.  TBL 21/dec/93
                    119:     */
1.1       timbl     120:     if (parts->access && ! parts->host && parts->anchor) {
                    121:       *(parts->anchor - 1) = '#';  /* Restore the '#' in the address */
                    122:       parts->anchor = 0;
                    123:     }
2.16      timbl     124: #endif
1.1       timbl     125: 
                    126: #ifdef NOT_DEFINED     /* search is just treated as part of path */
                    127:     {
                    128:         char *p = relative ? relative : absolute;
                    129:        if (p) {
                    130:            char * q = strchr(p, '?');  /* Any search string? */
                    131:            if (q) {
                    132:                *q = 0;                 /* If so, chop that off. */
                    133:                parts->search = q+1;
                    134:            }
                    135:        }
                    136:     }
                    137: #endif
                    138: } /*scan */    
                    139: 
                    140: 
                    141: /*     Parse a Name relative to another name
                    142: **     -------------------------------------
                    143: **
                    144: **     This returns those parts of a name which are given (and requested)
                    145: **     substituting bits from the related name where necessary.
                    146: **
                    147: ** On entry,
                    148: **     aName           A filename given
                    149: **      relatedName     A name relative to which aName is to be parsed
                    150: **      wanted          A mask for the bits which are wanted.
                    151: **
                    152: ** On exit,
                    153: **     returns         A pointer to a malloc'd string which MUST BE FREED
                    154: */
                    155: #ifdef __STDC__
                    156: char * HTParse(const char * aName, const char * relatedName, int wanted)
                    157: #else
                    158: char * HTParse(aName, relatedName, wanted)
                    159:     char * aName;
                    160:     char * relatedName;
                    161:     int wanted;
                    162: #endif
                    163: 
                    164: {
                    165:     char * result = 0;
                    166:     char * return_value = 0;
                    167:     int len;
                    168:     char * name = 0;
                    169:     char * rel = 0;
                    170:     char * p;
2.12      timbl     171:     char * access;
1.1       timbl     172:     struct struct_parts given, related;
                    173:     
                    174:     /* Make working copies of input strings to cut up:
                    175:     */
                    176:     len = strlen(aName)+strlen(relatedName)+10;
                    177:     result=(char *)malloc(len);                /* Lots of space: more than enough */
                    178:     if (result == NULL) outofmem(__FILE__, "HTParse");
                    179:     
                    180:     StrAllocCopy(name, aName);
                    181:     StrAllocCopy(rel, relatedName);
                    182:     
                    183:     scan(name, &given);
                    184:     scan(rel,  &related); 
                    185:     result[0]=0;               /* Clear string  */
2.12      timbl     186:     access = given.access ? given.access : related.access;
1.1       timbl     187:     if (wanted & PARSE_ACCESS)
2.12      timbl     188:         if (access) {
                    189:            strcat(result, access);
1.1       timbl     190:            if(wanted & PARSE_PUNCTUATION) strcat(result, ":");
                    191:        }
                    192:        
                    193:     if (given.access && related.access)        /* If different, inherit nothing. */
                    194:         if (strcmp(given.access, related.access)!=0) {
                    195:            related.host=0;
                    196:            related.absolute=0;
                    197:            related.relative=0;
                    198:            related.anchor=0;
                    199:        }
                    200:        
                    201:     if (wanted & PARSE_HOST)
                    202:         if(given.host || related.host) {
                    203:            if(wanted & PARSE_PUNCTUATION) strcat(result, "//");
                    204:            strcat(result, given.host ? given.host : related.host);
2.31    ! frystyk   205: #if 0
        !           206: /* This is now done in HTCanon */
2.12      timbl     207: #define CLEAN_URLS
2.31    ! frystyk   208: #endif
2.12      timbl     209: #ifdef CLEAN_URLS
                    210:            /* Ignore default port numbers, and trailing dots on FQDNs
                    211:               which will only cause identical adreesses to look different */
                    212:            {
2.31    ! frystyk   213:                char *tail = result + strlen(result);
        !           214:                char *p = strchr(tail, ':');
2.12      timbl     215:                if (p && access) {              /* Port specified */
                    216:                    if (  (   strcmp(access, "http") == 0
                    217:                           && strcmp(p, ":80") == 0 )
                    218:                        ||
                    219:                          (   strcmp(access, "gopher") == 0
                    220:                           && strcmp(p, ":70") == 0 )
                    221:                        )
                    222:                    *p = (char)0;       /* It is the default: ignore it */
                    223:                }
                    224:                if (!p) p = tail + strlen(tail); /* After hostname */
2.21      frystyk   225:                if (*p) {                                 /* Henrik 17/04-94 */
                    226:                    p--;                                /* End of hostname */
                    227:                    if (*p == '.') *p = (char)0; /* chop final . */
                    228:                }
2.12      timbl     229:            }
                    230: #endif
1.1       timbl     231:        }
                    232:        
                    233:     if (given.host && related.host)  /* If different hosts, inherit no path. */
                    234:         if (strcmp(given.host, related.host)!=0) {
                    235:            related.absolute=0;
                    236:            related.relative=0;
                    237:            related.anchor=0;
                    238:        }
                    239:        
                    240:     if (wanted & PARSE_PATH) {
                    241:         if(given.absolute) {                           /* All is given */
                    242:            if(wanted & PARSE_PUNCTUATION) strcat(result, "/");
                    243:            strcat(result, given.absolute);
                    244:        } else if(related.absolute) {   /* Adopt path not name */
                    245:            strcat(result, "/");
                    246:            strcat(result, related.absolute);
                    247:            if (given.relative) {
                    248:                p = strchr(result, '?');        /* Search part? */
                    249:                if (!p) p=result+strlen(result)-1;
                    250:                for (; *p!='/'; p--);   /* last / */
                    251:                p[1]=0;                                 /* Remove filename */
                    252:                strcat(result, given.relative);         /* Add given one */
2.31    ! frystyk   253:                result = HTSimplify (result);
1.1       timbl     254:            }
                    255:        } else if(given.relative) {
                    256:            strcat(result, given.relative);             /* what we've got */
                    257:        } else if(related.relative) {
                    258:            strcat(result, related.relative);
                    259:        } else {  /* No inheritance */
                    260:            strcat(result, "/");
                    261:        }
                    262:     }
                    263:                
                    264:     if (wanted & PARSE_ANCHOR)
                    265:         if(given.anchor || related.anchor) {
                    266:            if(wanted & PARSE_PUNCTUATION) strcat(result, "#");
                    267:            strcat(result, given.anchor ? given.anchor : related.anchor);
                    268:        }
                    269:     free(rel);
                    270:     free(name);
                    271:     
                    272:     StrAllocCopy(return_value, result);
                    273:     free(result);
                    274:     return return_value;               /* exactly the right length */
                    275: }
                    276: 
2.11      timbl     277: 
2.21      frystyk   278: #if 0  /* NOT USED FOR THE MOMENT */
2.15      luotonen  279: /*
                    280: **     As strcpy() but guaranteed to work correctly
                    281: **     with overlapping parameters.    AL 7 Feb 1994
                    282: */
                    283: PRIVATE void ari_strcpy ARGS2(char *, to,
                    284:                              char *, from)
                    285: {
                    286:     char * tmp;
                    287: 
                    288:     if (!to || !from) return;
                    289: 
                    290:     tmp = (char*)malloc(strlen(from)+1);
                    291:     if (!tmp) outofmem(__FILE__, "my_strcpy");
                    292: 
                    293:     strcpy(tmp, from);
                    294:     strcpy(to, tmp);
                    295:     free(tmp);
                    296: }
2.21      frystyk   297: #endif
                    298: 
2.20      timbl     299: 
                    300: /*             Simplify a URI
                    301: //             --------------
                    302: // A URI is allowed to contain the seqeunce xxx/../ which may be
1.1       timbl     303: // replaced by "" , and the seqeunce "/./" which may be replaced by "/".
2.20      timbl     304: // Simplification helps us recognize duplicate URIs. 
1.1       timbl     305: //
                    306: //     Thus,   /etc/junk/../fred       becomes /etc/fred
                    307: //             /etc/junk/./fred        becomes /etc/junk/fred
2.11      timbl     308: //
                    309: //      but we should NOT change
                    310: //             http://fred.xxx.edu/../..
                    311: //
                    312: //     or      ../../albert.html
2.26      frystyk   313: //
                    314: // In the same manner, the following prefixed are preserved:
                    315: //
                    316: //     ./<etc>
                    317: //     //<etc>
                    318: //
                    319: // In order to avoid empty URLs the following URLs become:
                    320: //
                    321: //             /fred/..                becomes /fred/..
                    322: //             /fred/././..            becomes /fred/..
2.27      frystyk   323: //             /fred/.././junk/.././   becomes /fred/..
2.26      frystyk   324: //
2.30      frystyk   325: // If more than one set of `://' is found (several proxies in cascade) then
                    326: // only the part after the last `://' is simplified.
1.1       timbl     327: */
2.31    ! frystyk   328: PUBLIC char *HTSimplify ARGS1(char *, filename)
1.1       timbl     329: {
2.31    ! frystyk   330:     char *path;
        !           331:     char *p;
2.19      frystyk   332: 
2.31    ! frystyk   333:     if (!filename) {
        !           334:        if (URI_TRACE)
        !           335:            fprintf(stderr, "HTSimplify.. Bad argument\n");
        !           336:        return filename;
        !           337:     }
        !           338:     if (URI_TRACE)
2.27      frystyk   339:        fprintf(stderr, "HTSimplify.. `%s\' ", filename);
                    340: 
2.31    ! frystyk   341:     if ((path = strstr(filename, "://")) != NULL) {       /* Find host name */
2.30      frystyk   342:        char *newptr;
2.31    ! frystyk   343:        path += 3;
        !           344:        while ((newptr = strstr(path, "://")) != NULL)
        !           345:            path = newptr+3;
        !           346:        path = HTCanon(&filename, path);              /* We have a host name */
        !           347:     } else if ((path = strstr(filename, ":/")) != NULL) {
        !           348:        path += 2;
2.27      frystyk   349:     } else
2.31    ! frystyk   350:        path = filename;
        !           351:     if (*path == '/' && *(path+1)=='/') {        /* Some URLs start //<foo> */
        !           352:        path += 1;
        !           353:     } else if (!strncmp(path, "news:", 5)) {       /* Make group lower case */
        !           354:        char *group = path+5;
        !           355:        while (*group && *group!='@' && *group!='/') {
        !           356:            *group = TOLOWER(*group);
        !           357:            group++;
        !           358:        }
        !           359:        if (URI_TRACE)
        !           360:            fprintf(stderr, "into\n............ `%s'\n", filename);
        !           361:        return filename;                      /* Doesn't need to do any more */
        !           362:     }
        !           363:     if ((p = path)) {
        !           364:        int segments = 0;
        !           365: 
        !           366:        /* Parse string first time to find number of `real' tokens */
        !           367:        while (*p) {
        !           368:            if (*p=='/' || p==path) {
        !           369:                if (!((*(p+1)=='/' || !*(p+1)) ||
        !           370:                      (*(p+1)=='.' && (*(p+2)=='/' || !*(p+2))) ||
        !           371:                      (*(p+1)=='.' && *(p+2)=='.' &&(*(p+3)=='/' || !*(p+3)))))
        !           372:                    segments++;
        !           373:            }
        !           374:            p++;
        !           375:        }
2.19      frystyk   376:        
2.31    ! frystyk   377:        /* Parse string second time to simplify */
        !           378:        p = path;
        !           379:        while(*p) {
        !           380:            if (*p=='/') {
        !           381:                if (p>path && *(p+1)=='.' && (*(p+2)=='/' || !*(p+2))) {
        !           382:                    char *orig=p, *dest=p+2;
        !           383:                    while ((*orig++ = *dest++)); /* Remove a slash and a dot */
        !           384:                    p--;
        !           385:                } else if (segments>1 && *(p+1)=='.' && *(p+2)=='.' &&
        !           386:                    (*(p+3)=='/' || !*(p+3))) {
        !           387:                    char *q = p;
        !           388:                    while (q>path && *--q!='/');               /* prev slash */
        !           389:                    if (strncmp(q, "/../", 4) && strncmp(q, "/./", 3) &&
        !           390:                        strncmp(q, "./", 2)) {
        !           391:                        char *orig=q, *dest=p+3;
        !           392:                        if (*q!='/') dest++;
        !           393:                        while ((*orig++ = *dest++));       /* Remove /xxx/.. */
        !           394:                        segments--;
        !           395:                        p = q-1;              /* Start again with prev slash */
        !           396:                    } else
        !           397:                        p++;
        !           398:                } else if (*(p+1)=='/') {
        !           399:                    while (*(p+1)=='/') {
        !           400:                        char *orig=p, *dest=p+1;
        !           401:                        while ((*orig++ = *dest++));  /* Remove multiple /'s */
2.19      frystyk   402:                    }
                    403:                }
                    404:            }
2.31    ! frystyk   405:            p++;
        !           406:        }  /* end while (*p) */
2.19      frystyk   407:     }
2.31    ! frystyk   408:     if (URI_TRACE)
2.27      frystyk   409:        fprintf(stderr, "into\n............ `%s'\n", filename);
2.31    ! frystyk   410:     return filename;
2.19      frystyk   411: }
2.31    ! frystyk   412: 
2.19      frystyk   413: #ifdef OLD_CODE
2.17      frystyk   414:     char * p = filename;
1.1       timbl     415:     char * q;
2.17      frystyk   416:     
                    417:     if (p) {
                    418:        while (*p && (*p == '/' || *p == '.'))     /* Pass starting / or .'s */
                    419:            p++;
                    420:        while(*p) {
                    421:            if (*p=='/') {
1.1       timbl     422:            if ((p[1]=='.') && (p[2]=='.') && (p[3]=='/' || !p[3] )) {
2.11      timbl     423:                for (q=p-1; (q>=filename) && (*q!='/'); q--); /* prev slash */
                    424:                if (q[0]=='/' && 0!=strncmp(q, "/../", 4)
                    425:                        &&!(q-1>filename && q[-1]=='/')) {
2.15      luotonen  426:                    ari_strcpy(q, p+3);         /* Remove  /xxx/..      */
1.1       timbl     427:                    if (!*filename) strcpy(filename, "/");
                    428:                    p = q-1;            /* Start again with prev slash  */
2.11      timbl     429:                } else {                        /*   xxx/.. leave it!   */
2.9       timbl     430: #ifdef BUG_CODE
2.15      luotonen  431:                    ari_strcpy(filename, p[3] ? p+4 : p+3); /* rm  xxx/../ */
1.1       timbl     432:                    p = filename;               /* Start again */
2.9       timbl     433: #endif
1.1       timbl     434:                }
                    435:            } else if ((p[1]=='.') && (p[2]=='/' || !p[2])) {
2.15      luotonen  436:                ari_strcpy(p, p+2);             /* Remove a slash and a dot */
2.13      luotonen  437:            } else if (p[-1] != ':') {
                    438:                while (p[1] == '/') {
2.15      luotonen  439:                    ari_strcpy(p, p+1); /* Remove multiple slashes */
2.13      luotonen  440:                }
1.1       timbl     441:            }
2.17      frystyk   442:            }
                    443:            p++;
                    444:        }  /* end while (*p) */
                    445:     } /* end if (p) */
1.1       timbl     446: }
2.19      frystyk   447: #endif /* OLD_CODE */
1.1       timbl     448: 
                    449: 
                    450: /*             Make Relative Name
                    451: **             ------------------
                    452: **
                    453: ** This function creates and returns a string which gives an expression of
                    454: ** one address as related to another. Where there is no relation, an absolute
                    455: ** address is retured.
                    456: **
                    457: **  On entry,
                    458: **     Both names must be absolute, fully qualified names of nodes
                    459: **     (no anchor bits)
                    460: **
                    461: **  On exit,
                    462: **     The return result points to a newly allocated name which, if
                    463: **     parsed by HTParse relative to relatedName, will yield aName.
                    464: **     The caller is responsible for freeing the resulting name later.
                    465: **
                    466: */
                    467: #ifdef __STDC__
                    468: char * HTRelative(const char * aName, const char *relatedName)
                    469: #else
                    470: char * HTRelative(aName, relatedName)
                    471:    char * aName;
                    472:    char * relatedName;
                    473: #endif
                    474: {
                    475:     char * result = 0;
                    476:     CONST char *p = aName;
                    477:     CONST char *q = relatedName;
                    478:     CONST char * after_access = 0;
                    479:     CONST char * path = 0;
                    480:     CONST char * last_slash = 0;
                    481:     int slashes = 0;
                    482:     
                    483:     for(;*p; p++, q++) {       /* Find extent of match */
                    484:        if (*p!=*q) break;
                    485:        if (*p==':') after_access = p+1;
                    486:        if (*p=='/') {
                    487:            last_slash = p;
                    488:            slashes++;
                    489:            if (slashes==3) path=p;
                    490:        }
                    491:     }
                    492:     
                    493:     /* q, p point to the first non-matching character or zero */
                    494:     
                    495:     if (!after_access) {                       /* Different access */
                    496:         StrAllocCopy(result, aName);
                    497:     } else if (slashes<3){                     /* Different nodes */
                    498:        StrAllocCopy(result, after_access);
2.29      frystyk   499: #if 0 /* Henrik */
1.1       timbl     500:     } else if (slashes==3){                    /* Same node, different path */
                    501:         StrAllocCopy(result, path);
2.21      frystyk   502: #endif
1.1       timbl     503:     } else {                                   /* Some path in common */
                    504:         int levels= 0;
                    505:         for(; *q && (*q!='#'); q++)  if (*q=='/') levels++;
                    506:        result = (char *)malloc(3*levels + strlen(last_slash) + 1);
                    507:       if (result == NULL) outofmem(__FILE__, "HTRelative");
                    508:        result[0]=0;
                    509:        for(;levels; levels--)strcat(result, "../");
                    510:        strcat(result, last_slash+1);
                    511:     }
2.31    ! frystyk   512:     if (URI_TRACE) fprintf(stderr,
2.21      frystyk   513:                      "HTRelative.. `%s' expressed relative to `%s' is `%s'\n",
                    514:                       aName, relatedName, result);
1.1       timbl     515:     return result;
                    516: }
2.1       timbl     517: 
                    518: 
2.31    ! frystyk   519: /*                                                            HTCanon
        !           520: **
        !           521: **     Canonicalizes the URL in the following manner starting from the host
        !           522: **     pointer:
        !           523: **
        !           524: **     1) The host name is converted to lowercase
        !           525: **     2) Expands the host name of the URL from a local name to a full
        !           526: **        domain name. A host name is started by `://'.
        !           527: **     3) The default port indication :80, :70, and :21 for are stripped
        !           528: **
        !           529: **     Return: OK      The position of the current path part of the URL
        !           530: */
        !           531: PUBLIC char *HTCanon ARGS2 (char **, filename, char *, host)
        !           532: {
        !           533:     char *new = NULL;
        !           534:     char *port;
        !           535:     char *strptr;
        !           536:     char *path;
        !           537: 
        !           538:     if ((path = strchr(host, '/')) == NULL)                    /* Find path */
        !           539:        path = host + strlen(host);
        !           540:     if ((strptr = strchr(host, '@')) != NULL && strptr<path)      /* UserId */
        !           541:        host = strptr;
        !           542:     port = strchr(host, ':');                                /* Port number */
        !           543: 
        !           544:     strptr = host;                                 /* Convert to lower-case */
        !           545:     while (strptr<path) {
        !           546:        *strptr = TOLOWER(*strptr);
        !           547:        strptr++;
        !           548:     }
        !           549:     
        !           550:     /* Does the URL contain a full domain name? This also works for a
        !           551:        numerical host name. The domain name is already made lower-case
        !           552:        and without a trailing dot. */
        !           553:     if ((strptr = strchr(host, '.')) == NULL || strptr >= path) {
        !           554:        CONST char *domain = HTGetDomainName();
        !           555:        if (domain) {
        !           556:            if ((new = (char *) calloc(1, strlen(*filename) +
        !           557:                                       strlen(domain)+2)) == NULL)
        !           558:                outofmem(__FILE__, "HTCanon");
        !           559:            if (port)
        !           560:                strncpy(new, *filename, (int) (port-*filename));
        !           561:            else
        !           562:                strncpy(new, *filename, (int) (path-*filename));
        !           563:            strcat(new, ".");
        !           564:            strcat(new, domain);
        !           565:        }
        !           566:     } else {                                     /* Look for a trailing dot */
        !           567:        char *dot = port ? port : path;
        !           568:        if (dot > *filename && *--dot=='.') {
        !           569:            char *orig=dot, *dest=dot+1;
        !           570:            while((*orig++ = *dest++));
        !           571:            if (port) port--;
        !           572:            path--;
        !           573:        }
        !           574:     }
        !           575: 
        !           576:     /* Chop off port if `:80' (http), `:70' (gopher), or `:21' (ftp) */
        !           577:     if (port) {
        !           578:        if ((*(port+1)=='8' && *(port+2)=='0' &&
        !           579:             (*(port+3)=='/' || !*(port+3))) ||
        !           580:            (*(port+1)=='2' && *(port+2)=='1' &&
        !           581:             (*(port+3)=='/' || !*(port+3))) ||
        !           582:            (*(port+1)=='7' && *(port+2)=='0' &&
        !           583:             (*(port+3)=='/' || !*(port+3)))) {
        !           584:            if (!new) {
        !           585:                char *orig=port, *dest=port+3;
        !           586:                while((*orig++ = *dest++));
        !           587:            }
        !           588:        } else if (new)
        !           589:            strncat(new, port, (int) (path-port));
        !           590:     }
        !           591:     if (new) {
        !           592:        char *newpath = new+strlen(new);
        !           593:        strcat(new, path);
        !           594:        path = newpath;
        !           595:        free(*filename);                                    /* Free old copy */
        !           596:        *filename = new;
        !           597:     }
        !           598:     return path;
        !           599: }
        !           600: 
        !           601: 
2.6       timbl     602: /*             Escape undesirable characters using %           HTEscape()
                    603: **             -------------------------------------
                    604: **
                    605: **     This function takes a pointer to a string in which
                    606: **     some characters may be unacceptable unescaped.
                    607: **     It returns a string which has these characters
                    608: **     represented by a '%' character followed by two hex digits.
                    609: **
2.20      timbl     610: **     In the tradition of being conservative in what you do and liberal
                    611: **     in what you accept, we encode some characters which in fact are
                    612: **     allowed in URLs unencoded -- so DON'T use the table below for
                    613: **     parsing! 
                    614: **
2.6       timbl     615: **     Unlike HTUnEscape(), this routine returns a malloced string.
2.20      timbl     616: **
2.6       timbl     617: */
                    618: 
2.20      timbl     619: /* Not BOTH static AND const at the same time in gcc :-(, Henrik 18/03-94 
                    620: **  code gen error in gcc when making random access to
                    621: **  static const table(!!)  */
2.19      frystyk   622: /* PRIVATE CONST unsigned char isAcceptable[96] = */
                    623: PRIVATE unsigned char isAcceptable[96] =
2.6       timbl     624: 
2.20      timbl     625: /* Overencodes */
2.6       timbl     626: /*     Bit 0           xalpha          -- see HTFile.h
                    627: **     Bit 1           xpalpha         -- as xalpha but with plus.
2.20      timbl     628: **     Bit 2 ...       path            -- as xpalpha but with /
2.6       timbl     629: */
                    630:     /*   0 1 2 3 4 5 6 7 8 9 A B C D E F */
                    631:     {    0,0,0,0,0,0,0,0,0,0,7,6,0,7,7,4,      /* 2x   !"#$%&'()*+,-./  */
                    632:          7,7,7,7,7,7,7,7,7,7,0,0,0,0,0,0,      /* 3x  0123456789:;<=>?  */
                    633:         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,       /* 4x  @ABCDEFGHIJKLMNO  */
                    634:         7,7,7,7,7,7,7,7,7,7,7,0,0,0,0,7,       /* 5X  PQRSTUVWXYZ[\]^_  */
                    635:         0,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,       /* 6x  `abcdefghijklmno  */
                    636:         7,7,7,7,7,7,7,7,7,7,7,0,0,0,0,0 };     /* 7X  pqrstuvwxyz{\}~  DEL */
                    637: 
                    638: PRIVATE char *hex = "0123456789ABCDEF";
                    639: 
2.8       timbl     640: PUBLIC char * HTEscape ARGS2 (CONST char *, str,
2.6       timbl     641:        unsigned char, mask)
                    642: {
                    643: #define ACCEPTABLE(a)  ( a>=32 && a<128 && ((isAcceptable[a-32]) & mask))
                    644:     CONST char * p;
                    645:     char * q;
                    646:     char * result;
                    647:     int unacceptable = 0;
                    648:     for(p=str; *p; p++)
                    649:         if (!ACCEPTABLE((unsigned char)TOASCII(*p)))
                    650:                unacceptable++;
                    651:     result = (char *) malloc(p-str + unacceptable+ unacceptable + 1);
                    652:     if (result == NULL) outofmem(__FILE__, "HTEscape");
                    653:     for(q=result, p=str; *p; p++) {
                    654:        unsigned char a = TOASCII(*p);
                    655:        if (!ACCEPTABLE(a)) {
                    656:            *q++ = HEX_ESCAPE;  /* Means hex commming */
                    657:            *q++ = hex[a >> 4];
                    658:            *q++ = hex[a & 15];
                    659:        }
                    660:        else *q++ = *p;
                    661:     }
                    662:     *q++ = 0;                  /* Terminate */
                    663:     return result;
                    664: }
                    665: 
                    666: 
2.1       timbl     667: /*             Decode %xx escaped characters                   HTUnEscape()
                    668: **             -----------------------------
                    669: **
                    670: **     This function takes a pointer to a string in which some
                    671: **     characters may have been encoded in %xy form, where xy is
                    672: **     the acsii hex code for character 16x+y.
                    673: **     The string is converted in place, as it will never grow.
                    674: */
                    675: 
                    676: PRIVATE char from_hex ARGS1(char, c)
                    677: {
2.6       timbl     678:     return  c >= '0' && c <= '9' ?  c - '0' 
                    679:            : c >= 'A' && c <= 'F'? c - 'A' + 10
                    680:            : c - 'a' + 10;     /* accept small letters just in case */
2.1       timbl     681: }
                    682: 
                    683: PUBLIC char * HTUnEscape ARGS1( char *, str)
                    684: {
                    685:     char * p = str;
                    686:     char * q = str;
2.25      frystyk   687: 
                    688:     if (!str) {                                              /* Just for safety ;-) */
2.31    ! frystyk   689:        if (URI_TRACE)
2.25      frystyk   690:            fprintf(stderr, "HTUnEscape.. Called with NULL argument.\n");
                    691:        return "";
                    692:     }
2.1       timbl     693:     while(*p) {
2.6       timbl     694:         if (*p == HEX_ESCAPE) {
2.1       timbl     695:            p++;
                    696:            if (*p) *q = from_hex(*p++) * 16;
                    697:            if (*p) *q = FROMASCII(*q + from_hex(*p++));
                    698:            q++;
                    699:        } else {
                    700:            *q++ = *p++; 
                    701:        }
                    702:     }
                    703:     
                    704:     *q++ = 0;
                    705:     return str;
                    706:     
                    707: } /* HTUnEscape */
                    708: 
                    709: 
2.24      luotonen  710: /*                                                     HTCleanTelnetString()
                    711:  *     Make sure that the given string doesn't contain characters that
                    712:  *     could cause security holes, such as newlines in ftp, gopher,
                    713:  *     news or telnet URLs; more specifically: allows everything between
2.26      frystyk   714:  *     ASCII 20-7E, and also A0-FE, inclusive. Also TAB ('\t') allowed!
2.24      luotonen  715:  *
                    716:  * On entry,
                    717:  *     str     the string that is *modified* if necessary.  The
                    718:  *             string will be truncated at the first illegal
                    719:  *             character that is encountered.
                    720:  * On exit,
                    721:  *     returns YES, if the string was modified.
                    722:  *             NO, otherwise.
                    723:  */
                    724: PUBLIC BOOL HTCleanTelnetString ARGS1(char *, str)
                    725: {
                    726:     char * cur = str;
                    727: 
                    728:     if (!str) return NO;
                    729: 
                    730:     while (*cur) {
                    731:        int a = TOASCII(*cur);
2.26      frystyk   732:        if (a != 0x9 && (a < 0x20 || (a > 0x7E && a < 0xA0) ||  a > 0xFE)) {
2.31    ! frystyk   733:            if (URI_TRACE)
        !           734:                fprintf(stderr, "Illegal..... character in URL: \"%s\"\n",str);
2.24      luotonen  735:            *cur = 0;
2.31    ! frystyk   736:            if (URI_TRACE)
        !           737:                fprintf(stderr, "Truncated... \"%s\"\n",str);
2.24      luotonen  738:            return YES;
                    739:        }
                    740:        cur++;
                    741:     }
                    742:     return NO;
                    743: }
                    744: 

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