htparse.c

www工具包. 这是W3C官方支持的www支撑库. 其中提供通用目的的客户端的WebAPI: complete HTTP/1.1 (with caching, pipelining, PUT, POS

	    char *orig=dot, *dest=dot+1;
	    while((*orig++ = *dest++));
	    if (port) port--;
	    path--;
	}
    }
    /* Chop off port if `:', `:80' (http), `:70' (gopher), or `:21' (ftp) */
    if (port) {
	if (!*(port+1) || *(port+1)=='/') {
	    if (!newname) {
		char *orig=port, *dest=port+1;
		while((*orig++ = *dest++));
	    }
	} else if ((!strncmp(access, "http", 4) &&
	     (*(port+1)=='8'&&*(port+2)=='0'&&(*(port+3)=='/'||!*(port+3)))) ||
	    (!strncmp(access, "gopher", 6) &&
	     (*(port+1)=='7'&&*(port+2)=='0'&&(*(port+3)=='/'||!*(port+3)))) ||
	    (!strncmp(access, "ftp", 3) &&
	     (*(port+1)=='2'&&*(port+2)=='1'&&(*(port+3)=='/'||!*(port+3))))) {
	    if (!newname) {
		char *orig=port, *dest=port+3;
		while((*orig++ = *dest++));
		path -= 3;   	       /* Update path position, Henry Minsky */
	    }
	} else if (newname)
	    strncat(newname, port, (int) (path-port));
    }

    if (newname) {
	char *newpath = newname+strlen(newname);
	strcat(newname, path);
	path = newpath;
	HT_FREE(*filename);				    /* Free old copy */
	*filename = newname;
    }
    return path;
}

/*
**  Search the URL and determine whether it is a relative or absolute URL.
**  We check to see if there is a ":" before any "/", "?", and "#". If this
**  is the case then we say it is absolute. Otherwise it is relative.
*/
PUBLIC BOOL HTURL_isAbsolute (const char * url)
{    
    if (url) {	
	const char * ptr = url;
	while (*ptr) {
	    if (*ptr == ':') return YES;
	    if (*ptr == '/' || *ptr == '?' || *ptr == '#') break;
	    ptr ++;
	}
    }	
    return NO;
}

/*	        Simplify a URI
//		--------------
// A URI is allowed to contain the seqeunce xxx/../ which may be
// replaced by "" , and the seqeunce "/./" which may be replaced by "/".
// Simplification helps us recognize duplicate URIs. 
//
//	Thus, 	/etc/junk/../fred 	becomes	/etc/fred
//		/etc/junk/./fred	becomes	/etc/junk/fred
//
//      but we should NOT change
//		http://fred.xxx.edu/../..
//
//	or	../../albert.html
//
// In order to avoid empty URLs the following URLs become:
//
//		/fred/..		becomes /fred/..
//		/fred/././..		becomes /fred/..
//		/fred/.././junk/.././	becomes /fred/..
//
// If more than one set of `://' is found (several proxies in cascade) then
// only the part after the last `://' is simplified.
//
// Returns: A string which might be the old one or a new one.
*/
PUBLIC char *HTSimplify (char ** url)
{
    char *path;
    char *p;
    if (!url || !*url) {
	HTTRACE(URI_TRACE, "HTSimplify.. Nothing done\n");
	return *url;
    }
    HTTRACE(URI_TRACE, "HTSimplify.. `%s\' " _ *url);

    /* Find any scheme name */
    if ((path = strstr(*url, "://")) != NULL) {		   /* Find host name */
	char *newptr;
	char *access = *url;
	while (access<path && (*access=TOLOWER(*access))) access++;
	path += 3;
	while ((newptr = strstr(path, "://")) != NULL)        /* For proxies */
	    path = newptr+3;
	path = HTCanon(url, path);       	      /* We have a host name */
    } else if ((path = strstr(*url, ":/")) != NULL) {
	path += 2;
    } else
	path = *url;
    if (*path == '/' && *(path+1)=='/') {	  /* Some URLs start //<foo> */
	path += 1;
    } else if (!strncmp(path, "news:", 5)) {
	char *ptr = strchr(path+5, '@');
	if (!ptr) ptr = path+5;
	while (*ptr) {			    /* Make group or host lower case */
	    *ptr = TOLOWER(*ptr);
	    ptr++;
	}
	HTTRACE(URI_TRACE, "into\n............ `%s'\n" _ *url);
	return *url;		      /* Doesn't need to do any more */
    }
    if ((p = path)) {
	char *end;
	if (!((end = strchr(path, ';')) || (end = strchr(path, '?')) ||
	      (end = strchr(path, '#'))))
	    end = path+strlen(path);

	/* Parse string second time to simplify */
	p = path;
	while(p<end) {
	    if (*p=='/') {
		if (p>*url && *(p+1)=='.' && (*(p+2)=='/' || !*(p+2))) {
		    char *orig = p+1;
		    char *dest = (*(p+2)!='/') ? p+2 : p+3;
		    while ((*orig++ = *dest++)); /* Remove a slash and a dot */
		    end = orig-1;
		} else if (*(p+1)=='.' && *(p+2)=='.' && (*(p+3)=='/' || !*(p+3))) {
		    char *q = p;
		    while (q>path && *--q!='/');	       /* prev slash */
		    if (strncmp(q, "/../", 4)) {
			char *orig = q+1;
			char *dest = (*(p+3)!='/') ? p+3 : p+4;
			while ((*orig++ = *dest++));	   /* Remove /xxx/.. */
			end = orig-1;
			p = q;		      /* Start again with prev slash */
		    } else
			p++;
		} else if (*(p+1)=='/') {
		    while (*(p+1)=='/') {
			char *orig=p, *dest=p+1;
			while ((*orig++ = *dest++));  /* Remove multiple /'s */
			end = orig-1;
		    }
		} else
		    p++;
	    } else
		p++;
	}
    }

    /*
    **  Check for host/../.. kind of things
    */
    while (*path=='/' && *(path+1)=='.' && *(path+2)=='.' &&
	   (!*(path+3) || *(path+3)=='/')) {
	char * orig = path;
	char * dest = path+3;
	while ((*orig++ = *dest++));
    }
    HTTRACE(URI_TRACE, "into\n............ `%s'\n" _ *url);
    return *url;
}

/*		Make Relative Name
**		------------------
**
** This function creates and returns a string which gives an expression of
** one address as related to another. Where there is no relation, an absolute
** address is retured.
**
**  On entry,
**	Both names must be absolute, fully qualified names of nodes
**	(no fragment bits)
**
**  On exit,
**	The return result points to a newly allocated name which, if
**	parsed by HTParse relative to relatedName, will yield aName.
**	The caller is responsible for freeing the resulting name later.
**
*/
PUBLIC char * HTRelative (const char * aName, const char * relatedName)
{
    char * result = 0;
    const char *p = aName;
    const char *q = relatedName;
    const char * after_access = NULL;
    const char * path = 0;
    const char * last_slash = 0;
    int slashes = 0;
    
    for(;*p; p++, q++) {	/* Find extent of match */
    	if (*p!=*q) break;
	if (*p==':') if (!after_access) after_access = p+1;
	if (*p=='/') {
	    last_slash = p;
	    slashes++;
	    if (slashes==3) path=p;
	}
    }
    
    /* q, p point to the first non-matching character or zero */
    
    if (!after_access) {			/* Different access */
        StrAllocCopy(result, aName);
    } else if (slashes<3){			/* Different nodes */
    	StrAllocCopy(result, after_access);
    } else {					/* Some path in common */
        int levels= 0;
        for(; *q && *q!='#' && *q!=';' && *q!='?'; q++) if (*q=='/') levels++;
	if ((result = (char  *) HT_MALLOC(3*levels + strlen(last_slash) + 4)) == NULL)
	    HT_OUTOFMEM("HTRelative");
	*result = '\0';
	if (!levels) strcat(result, "./");
	for(;levels; levels--)strcat(result, "../");
	strcat(result, last_slash+1);
	if (!*result) strcat(result, "./");
    }
    HTTRACE(URI_TRACE, "HTRelative.. `%s' expressed relative to  `%s' is `%s'\n" _ 
		aName _ relatedName _ result);
#if 0
    {
	char * absstr = HTParse(result, relatedName, PARSE_ALL);
	HTSimplify(&absstr);
	HTTRACE(URI_TRACE, "HTRelative.. `%s' made absolute based on `%s' is `%s'\n" _
		result _ relatedName _ absstr);
	if (strcmp(absstr, aName) != 0) HTTRACE(URI_TRACE, "THEY DIFFER!!!\n");
	HT_FREE(absstr);
    }
#endif
    return result;
}

/*							HTCleanTelnetString()
 *	Make sure that the given string doesn't contain characters that
 *	could cause security holes, such as newlines in ftp, gopher,
 *	news or telnet URLs; more specifically: allows everything between
 *	ASCII 20-7E, and also A0-FE, inclusive. Also TAB ('\t') allowed!
 *
 * On entry,
 *	str	the string that is *modified* if necessary.  The
 *		string will be truncated at the first illegal
 *		character that is encountered.
 * On exit,
 *	returns	YES, if the string was modified.
 *		NO, otherwise.
 */
PUBLIC BOOL HTCleanTelnetString (char * str)
{
    char * cur = str;

    if (!str) return NO;

    while (*cur) {
	int a = TOASCII((unsigned char) *cur);
	if (a != 0x9 && (a < 0x20 || (a > 0x7E && a < 0xA0) ||  a > 0xFE)) {
	    HTTRACE(URI_TRACE, "Illegal..... character in URL: \"%s\"\n" _ str);
	    *cur = 0;
	    HTTRACE(URI_TRACE, "Truncated... \"%s\"\n" _ str);
	    return YES;
	}
	cur++;
    }
    return NO;
}