/*		Access Manager					HTAccess.c
**		==============
**
** Authors
**	TBL	Tim Berners-Lee timbl@info.cern.ch
**	JFG	Jean-Francois Groff jfg@dxcern.cern.ch
**	DD	Denis DeLaRoca (310) 825-4580  <CSP1DWD@mvs.oac.ucla.edu>
** History
**       8 Jun 92 Telnet hopping prohibited as telnet is not secure TBL
**	26 Jun 92 When over DECnet, suppressed FTP, Gopher and News. JFG
**	 6 Oct 92 Moved HTClientHost and HTlogfile into here. TBL
**	17 Dec 92 Tn3270 added, bug fix. DD
**	 4 Feb 93 Access registration, Search escapes bad chars TBL
**		  PARAMETERS TO HTSEARCH AND HTLOADRELATIVE CHANGED
**	28 May 93 WAIS gateway explicit if no WAIS library linked in.
**	   Dec 93 Bug change around, more reentrant, etc
**	09 May 94 logfile renamed to HTlogfile to avoid clash with WAIS
**	 8 Jul 94 Insulate free() from _free structure element.
** Bugs
**	This module assumes that that the graphic object is hypertext, as it
**	needs to select it when it has been loaded.  A superclass needs to be
**	defined which accepts select and select_anchor.
*/

#ifndef DEFAULT_WAIS_GATEWAY
#define DEFAULT_WAIS_GATEWAY "http://info.cern.ch:8001/"
#endif

/* Implements:
*/
#include "HTAccess.h"

/* Uses:
*/

#include "HTParse.h"
#include "HTUtils.h"
#include "HTML.h"		/* SCW */

#ifndef NO_RULES
#include "HTRules.h"
#endif

#include "HTList.h"
#include "HText.h"	/* See bugs above */
#include "HTAlert.h"
#include "HTFWriter.h"	/* for cache stuff */
#include "HTTee.h"
#include "HTError.h"

/* These flags may be set to modify the operation of this module */
PUBLIC char * HTCacheDir = NULL;  /* Root for cached files or 0 for no cache */
PUBLIC char * HTSaveLocallyDir = SAVE_LOCALLY_HOME_DIR;	 /* Save & exe files */
PUBLIC char * HTClientHost = 0;		 /* Name of remote login host if any */
PUBLIC FILE * HTlogfile = 0;	       /* File to which to output one-liners */

PUBLIC BOOL HTForceReload = NO;	/* Force reload from cache or net */
PUBLIC BOOL HTSecure = NO;	/* Disable access for telnet users? */
PUBLIC BOOL using_proxy = NO;	/* are we using a proxy gateway? */
PUBLIC char * HTImServer = NULL;/* cern_httpd sets this to the translated URL*/
PUBLIC BOOL HTImProxy = NO;	/* cern_httpd as a proxy? */


/*	To generate other things, play with these:
*/

/* PUBLIC HTFormat HTOutputFormat = NULL;	use request->output_format */
/* PUBLIC HTStream* HTOutputStream = NULL;	use request->output_stream */ 

PRIVATE HTList * protocols = NULL;   /* List of registered protocol descriptors */

/* 	Superclass defn */

struct _HTStream {
	HTStreamClass * isa;
	/* ... */
};

/*	Create  a request structure
**	---------------------------
*/

PUBLIC HTRequest * HTRequest_new NOARGS
{
    HTRequest * me = (HTRequest*) calloc(1, sizeof(*me));  /* zero fill */
    if (!me) outofmem(__FILE__, "HTRequest_new()");
    
    me->conversions	= HTList_new();	/* No conversions registerd yet */
    me->output_format	= WWW_PRESENT;	/* default it to present to user */

    return me;
}


/*	Clear  a request structure
**	---------------------------
**	This function clears the reguest structure so that only the
**	conversions remain. Everything else is as if it was created from
**	scratch.
*/
PUBLIC void HTRequest_clear ARGS1(HTRequest *, req)
{
    HTList *conversions;
    if (!req) {
	if (TRACE)
	    fprintf(stderr, "Clear....... request: Bad argument!\n");
	return;
    }
    conversions = req->conversions;		     /* Save the conversions */
    HTErrorFree(req);
    HTAACleanup(req);
    FREE(req->from);
    memset(req, '\0', sizeof(HTRequest));

    /* Now initialize as from scratch but with the old list of conversions */
    req->conversions = conversions;
    req->output_format = WWW_PRESENT;	    /* default it to present to user */
}


/*	Delete a request structure
**	--------------------------
*/
PUBLIC void HTRequest_delete ARGS1(HTRequest *, req)
{
    if (req) {
	HTFormatDelete(req->conversions);
	HTErrorFree(req);
	HTAACleanup(req);
	FREE(req->from);
	FREE(req);
    }
}


PRIVATE char * method_names[(int)MAX_METHODS + 1] =
{
    "INVALID-METHOD",
    "GET",
    "HEAD",
    "POST",
    "PUT",
    "DELETE",
    "CHECKOUT",
    "CHECKIN",
    "SHOWMETHOD",
    "LINK",
    "UNLINK",
    NULL
};

/*	Get method enum value
**	---------------------
*/
PUBLIC HTMethod HTMethod_enum ARGS1(char *, name)
{
    if (name) {
	int i;
	for (i=1; i < (int)MAX_METHODS; i++)
	    if (!strcmp(name, method_names[i]))
		return (HTMethod)i;
    }
    return METHOD_INVALID;
}


/*	Get method name
**	---------------
*/
PUBLIC char * HTMethod_name ARGS1(HTMethod, method)
{
    if ((int)method > (int)METHOD_INVALID  && 
	(int)method < (int)MAX_METHODS)
	return method_names[(int)method];
    else
	return method_names[(int)METHOD_INVALID];
}


/*	Is method in a list of method names?
**	-----------------------------------
*/
PUBLIC BOOL HTMethod_inList ARGS2(HTMethod,	method,
				  HTList *,	list)
{
    char * method_name = HTMethod_name(method);
    HTList *cur = list;
    char *item;

    while (NULL != (item = (char*)HTList_nextObject(cur))) {
	CTRACE(stderr, " %s", item);
	if (0==strcasecomp(item, method_name))
	    return YES;
    }
    return NO;	/* Not found */
}





/*	Register a Protocol				HTRegisterProtocol
**	-------------------
*/

PUBLIC BOOL HTRegisterProtocol(protocol)
	HTProtocol * protocol;
{
    if (!protocols) protocols = HTList_new();
    HTList_addObject(protocols, protocol);
    return YES;
}


/*	Register all known protocols
**	----------------------------
**
**	Add to or subtract from this list if you add or remove protocol modules.
**	This routine is called the first time the protocol list is needed,
**	unless any protocols are already registered, in which case it is not
**	called. Therefore the application can override this list.
**
**	Compiling with NO_INIT prevents all known protocols from being forced
**	in at link time.
*/
#ifndef NO_INIT
PRIVATE void HTAccessInit NOARGS			/* Call me once */
{
GLOBALREF HTProtocol HTTP, HTFile, HTTelnet, HTTn3270, HTRlogin;
#ifndef DECNET
#ifdef NEW_CODE
GLOBALREF  HTProtocol HTFTP, HTNews, HTNNTP, HTGopher;
#endif
GLOBALREF  HTProtocol HTFTP, HTNews, HTGopher;

#ifdef DIRECT_WAIS
GLOBALREF  HTProtocol HTWAIS;
#endif
    HTRegisterProtocol(&HTFTP);
    HTRegisterProtocol(&HTNews);
#ifdef NEW_CODE
    HTRegisterProtocol(&HTNNTP);
#endif
    HTRegisterProtocol(&HTGopher);

#ifdef DIRECT_WAIS
    HTRegisterProtocol(&HTWAIS);
#endif

#endif /* DECNET */
    HTRegisterProtocol(&HTTP);
    HTRegisterProtocol(&HTFile);
    HTRegisterProtocol(&HTTelnet);
    HTRegisterProtocol(&HTTn3270);
    HTRegisterProtocol(&HTRlogin);
}
#endif



/*							override_proxy()
**
**	Check the no_proxy environment variable to get the list
**	of hosts for which proxy server is not consulted.
**
**	no_proxy is a comma- or space-separated list of machine
**	or domain names, with optional :port part.  If no :port
**	part is present, it applies to all ports on that domain.
**
**	Example:
**		no_proxy="cern.ch,some.domain:8001"
**
*/
PRIVATE BOOL override_proxy ARGS1(CONST char *, addr)
{
    CONST char * no_proxy = getenv("no_proxy");
    char * p = NULL;
    char * host = NULL;
    int port = 0;
    int h_len = 0;

    if (!no_proxy || !addr || !(host = HTParse(addr, "", PARSE_HOST)))
	return NO;
    if (!*host) { free(host); return NO; }

    if ((p = strchr(host, ':')) != NULL) {	/* Port specified */
	*p++ = 0;			/* Chop off port */
	port = atoi(p);
    }
    else {				/* Use default port */
	char * access = HTParse(addr, "", PARSE_ACCESS);
	if (access) {
	    if	    (!strcmp(access,"http"))	port = 80;
	    else if (!strcmp(access,"gopher"))	port = 70;
	    else if (!strcmp(access,"ftp"))	port = 21;
	    free(access);
	}
    }
    if (!port) port = 80;		/* Default */
    h_len = strlen(host);

    while (*no_proxy) {
	CONST char * end;
	CONST char * colon = NULL;
	int templ_port = 0;
	int t_len;

	while (*no_proxy && (WHITE(*no_proxy) || *no_proxy==','))
	    no_proxy++;			/* Skip whitespace and separators */

	end = no_proxy;
	while (*end && !WHITE(*end) && *end != ',') {	/* Find separator */
	    if (*end==':') colon = end;			/* Port number given */
	    end++;
	}

	if (colon) {
	    templ_port = atoi(colon+1);
	    t_len = colon - no_proxy;
	}
	else {
	    t_len = end - no_proxy;
	}

	if ((!templ_port || templ_port == port)  &&
	    (t_len > 0  &&  t_len <= h_len  &&
	     !strncmp(host + h_len - t_len, no_proxy, t_len))) {
	    free(host);
	    return YES;
	}
	if (*end) no_proxy = end+1;
	else break;
    }

    free(host);
    return NO;
}



/*		Find physical name and access protocol
**		--------------------------------------
**
**
** On entry,
**	addr		must point to the fully qualified hypertext reference.
**	anchor		a pareent anchor with whose address is addr
**
** On exit,
**	returns		HT_NO_ACCESS		Error has occured.
**			HT_OK			Success
**
*/
PRIVATE int get_physical ARGS1(HTRequest *, req)
{    
    char * access=0;	/* Name of access method */
    char * addr = HTAnchor_address((HTAnchor*)req->anchor);	/* free me */

    /*
    ** This HACK is here until we have redirection implemented.
    ** This is used when we are recursively calling HTLoad().
    ** We then take the physical address, because currently the
    ** virtual address is kept in a hash table so it can't be
    ** changed -- otherwise it wouldn't be found anymore.
    */
    if (HTAnchor_physical(req->anchor))
	StrAllocCopy(addr, HTAnchor_physical(req->anchor));

#ifndef NO_RULES
    if (HTImServer) {	/* cern_httpd has already done its own translations */
	HTAnchor_setPhysical(req->anchor, HTImServer);
	StrAllocCopy(addr, HTImServer);	/* Oops, queries thru many proxies */
					/* didn't work without this -- AL  */
    }
    else {
	char * physical = HTTranslate(addr);
	if (!physical) {
	    free(addr);
	    return HT_FORBIDDEN;
	}
	HTAnchor_setPhysical(req->anchor, physical);
	free(physical);			/* free our copy */
    }
#else
    HTAnchor_setPhysical(req->anchor, addr);
#endif

    access =  HTParse(HTAnchor_physical(req->anchor),
		      "file:", PARSE_ACCESS);

/*	Check whether gateway access has been set up for this
**
**	This function can be replaced by the rule system above.
*/
#define USE_GATEWAYS
#ifdef USE_GATEWAYS

    /* make sure the using_proxy variable is false */
    using_proxy = NO;

    if (!override_proxy(addr)) {
	char * gateway_parameter, *gateway, *proxy;

	gateway_parameter = (char *)malloc(strlen(access)+20);
	if (gateway_parameter == NULL) outofmem(__FILE__, "HTLoad");

	/* search for proxy gateways */
	strcpy(gateway_parameter, "WWW_");
	strcat(gateway_parameter, access);
	strcat(gateway_parameter, "_GATEWAY");
	gateway = (char *)getenv(gateway_parameter); /* coerce for decstation */

	/* search for proxy servers */
	strcpy(gateway_parameter, access);
	strcat(gateway_parameter, "_proxy");
	proxy = (char *)getenv(gateway_parameter);

	free(gateway_parameter);

	if (TRACE && gateway)
	    fprintf(stderr,"Gateway found: %s\n",gateway);
	if (TRACE && proxy)
	    fprintf(stderr,"Proxy server found: %s\n",proxy);

#ifndef DIRECT_WAIS
	if (!gateway && 0==strcmp(access, "wais")) {
	    gateway = DEFAULT_WAIS_GATEWAY;
	}
#endif

	/* proxy servers have precedence over gateway servers */
	if (proxy) {
	    char * gatewayed=0;

            StrAllocCopy(gatewayed,proxy);
	    StrAllocCat(gatewayed,addr);
	    using_proxy = YES;
	    HTAnchor_setPhysical(req->anchor, gatewayed);
	    free(gatewayed);
	    free(access);

	    access =  HTParse(HTAnchor_physical(req->anchor),
			      "http:", PARSE_ACCESS);
	} else if (gateway) {
	    char * path = HTParse(addr, "",
	    	PARSE_HOST + PARSE_PATH + PARSE_PUNCTUATION);
		/* Chop leading / off to make host into part of path */
	    char * gatewayed = HTParse(path+1, gateway, PARSE_ALL);
	    free(path);
            HTAnchor_setPhysical(req->anchor, gatewayed);
	    free(gatewayed);
	    free(access);
	    
    	    access =  HTParse(HTAnchor_physical(req->anchor),
    		"http:", PARSE_ACCESS);
	}
    }
#endif

    free(addr);


/*	Search registered protocols to find suitable one
*/
    {
	HTList *cur;
	HTProtocol *p;
#ifndef NO_INIT
        if (!protocols) HTAccessInit();
#endif
	cur = protocols;
	while ((p = (HTProtocol*)HTList_nextObject(cur))) {
	    if (strcmp(p->name, access)==0) {
		HTAnchor_setProtocol(req->anchor, p);
		free(access);
		return (HT_OK);
	    }
	}
    }

    free(access);
    return HT_NO_ACCESS;
}


/*		Load a document
**		---------------
**
**	This is an internal routine, which has an address AND a matching
**	anchor.  (The public routines are called with one OR the other.)
**
** On entry,
**	request->
**	    anchor		a parent anchor with fully qualified
**				hypertext reference as its address set
**	    output_format	valid
**	    output_stream	valid on NULL
**
** On exit,
**	returns		<0		Error has occured.
**			HT_LOADED	Success
**			HT_NO_DATA	Success, but no document loaded.
**					(telnet sesssion started etc)
**
*/
PUBLIC int HTLoad ARGS2(HTRequest *, request, BOOL, keep_error_stack)
{
    char	*arg = NULL;
    HTProtocol	*p;
    int 	status;

    if (request->method == METHOD_INVALID)
	request->method = METHOD_GET;
    if (!keep_error_stack) {
	HTErrorFree(request);
	request->error_block = NO;
    }

    status = get_physical(request);
    if (status == HT_FORBIDDEN) {
	char *url = HTAnchor_address((HTAnchor *) request->anchor);
	if (url) {
	    HTUnEscape(url);
	    HTErrorAdd(request, ERR_FATAL, NO, HTERR_FORBIDDEN,
		       (void *) url, (int) strlen(url), "HTLoad");
	    free(url);
	} else {
	    HTErrorAdd(request, ERR_FATAL, NO, HTERR_FORBIDDEN,
		       NULL, 0, "HTLoad");
	}
	return -1;
    }
    if (status < 0) return status;	/* Can't resolve or forbidden */

    if(!(arg = HTAnchor_physical(request->anchor)) || !*arg) 
    	return (-1);

    p = HTAnchor_protocol(request->anchor);
    return (*(p->load))(request);
}


/*		Get a save stream for a document
**		--------------------------------
*/
PUBLIC HTStream *HTSaveStream ARGS1(HTRequest *, request)
{
    HTProtocol * p;
    int status;
    request->method = METHOD_PUT;
    status = get_physical(request);
    if (status == HT_FORBIDDEN) {
	char *url = HTAnchor_address((HTAnchor *) request->anchor);
	if (url) {
	    HTUnEscape(url);
	    HTErrorAdd(request, ERR_FATAL, NO, HTERR_FORBIDDEN,
		       (void *) url, (int) strlen(url), "HTLoad");
	    free(url);
	} else {
	    HTErrorAdd(request, ERR_FATAL, NO, HTERR_FORBIDDEN,
		       NULL, 0, "HTLoad");
	}
	return NULL;	/* should return error status? */
    }
    if (status < 0) return NULL; /* @@ error. Can't resolve or forbidden */
    
    p = HTAnchor_protocol(request->anchor);
    if (!p) return NULL;
    
    return (*p->saveStream)(request);
    
}


/*		Load a document - with logging etc
**		----------------------------------
**
**	- Checks or documents already loaded
**	- Logs the access
**	- Allows stdin filter option
**	- Trace ouput and error messages
**
**    On Entry,
**        request->anchor	valid for of the document to be accessed.
**	 request->childAnchor   optional anchor within doc to be selected
**
**        filter            if YES, treat stdin as HTML
**
**	  request->anchor   is the node_anchor for the document
**	  request->output_format is valid
**
**    On Exit,
**        returns    YES     Success in opening document
**                   NO      Failure 
**
*/

PRIVATE BOOL HTLoadDocument ARGS2(HTRequest *,		request,
				  BOOL,			keep_error_stack)

{
    int	        status;
    HText *	text;
    char * full_address = HTAnchor_address((HTAnchor*)request->anchor);

    if (TRACE) fprintf (stderr, "HTAccess.... Loading document %s\n",
			full_address);

    request->using_cache = NULL;
    
    if (!request->output_format) request->output_format = WWW_PRESENT;

    if (!HTForceReload && (text=(HText *)HTAnchor_document(request->anchor)))
    {	/* Already loaded */
        if (TRACE) fprintf(stderr, "HTAccess: Document already in memory.\n");
	if (request->childAnchor) {
	    HText_selectAnchor(text, request->childAnchor);
	} else {
	    HText_select(text);	
	}
	free(full_address);
	return YES;
    }
    
    /* Check the Cache */
    /* Bug: for each format, we only check whether it is ok, we
       don't check them all and chose the best */
    if (request->anchor->cacheItems) {
        HTList * list = request->anchor->cacheItems;
	HTList * cur = list;
	HTCacheItem * item;

	while ((item = (HTCacheItem*)HTList_nextObject(cur))) {
	    HTStream * s;
	    
	    request->using_cache = item;
	    
	    s = HTStreamStack(item->format, request, NO);
	    if (s) {		/* format was suitable */
	        FILE * fp = fopen(item->filename, "r");
	    	if (TRACE) fprintf(stderr, "Cache: HIT file %s for %s\n",
				   item->filename, 
				   full_address);
		if (fp) {
		    HTFileCopy(fp, s);
		    (*s->isa->_free)(s);	/* close up pipeline */
		    fclose(fp);
		    free(full_address);
		    return YES;
		} else {
		    fprintf(stderr, "***** Can't read cache file %s !\n",
			    item->filename);
		} /* file open ok */
	    } /* stream ok */
	} /* next cache item */
    } /* if cache available for this anchor */
    
    status = HTLoad(request, keep_error_stack);

/*	Log the access if necessary
*/
    if (HTlogfile) {
	time_t theTime;
	time(&theTime);
	fprintf(HTlogfile, "%24.24s %s %s %s\n",
	    ctime(&theTime),
	    HTClientHost ? HTClientHost : "local",
	    status<0 ? "FAIL" : "GET",
	    full_address);
	fflush(HTlogfile);	/* Actually update it on disk */
	if (TRACE) fprintf(stderr, "Log: %24.24s %s %s %s\n",
	    ctime(&theTime),
	    HTClientHost ? HTClientHost : "local",
	    status<0 ? "FAIL" : "GET",
	    full_address);
    }

    /* The error stack might contain general information to the client
       about what has been going on in the library (not only errors) */
    if (request->error_stack)
	HTErrorMsg(request);

    if (status == HT_LOADED) {
	if (TRACE) {
	    fprintf(stderr, "HTAccess.... `%s' has been accessed.\n",
	    full_address);
	}
	free(full_address);
	return YES;
    }
    
    if (status == HT_NO_DATA) {
	if (TRACE) {
	    fprintf(stderr, 
	    "HTAccess.... `%s' has been accessed, No data left.\n",
	    full_address);
	}
	free(full_address);
	return NO;
    }
    
    /* Bug fix thanks to Lou Montulli. Henrik 10/03-94 */
    if (status<=0) {		      /* Failure in accessing a document */
#ifdef CURSES
        user_message("Can't access `%s'", full_address);
#else
	if (TRACE) fprintf(stderr, 
		"HTAccess: Can't access `%s'\n", full_address);
#endif
	free(full_address);
	return NO;
    }
 
    /* If you get this, then please find which routine is returning
       a positive unrecognised error code! */
    fprintf(stderr,
    "**** HTAccess: Internal software error in CERN WWWLib version %s ****\n\nPlease mail www-bug@info.cern.ch quoting what software and what version you are using\nand the URL: %s that caused the problem, thanks!\n",
	    HTLibraryVersion,
	    full_address);
    free(full_address);
   
    exit(-6996);
    return NO;	/* For gcc :-( */
} /* HTLoadDocument */



/*		Load a document from absolute name
**		---------------
**
**    On Entry,
**        addr     The absolute address of the document to be accessed.
**        filter   if YES, treat document as HTML
**
**    On Exit,
**        returns    YES     Success in opening document
**                   NO      Failure 
**
**
*/

PUBLIC BOOL HTLoadAbsolute ARGS2(CONST char *,addr, HTRequest*, request)
{
   HTAnchor * anchor = HTAnchor_findAddress(addr);
   request->anchor = HTAnchor_parent(anchor);
   request->childAnchor = ((HTAnchor*)request->anchor == anchor) ?
   			NULL : (HTChildAnchor*) anchor;
   return HTLoadDocument(request, NO);
}


/*		Load a document from absolute name to stream
**		--------------------------------------------
**
**    On Entry,
**        addr     The absolute address of the document to be accessed.
**        request->output_stream     if non-NULL, send data down this stream
**
**    On Exit,
**        returns    YES     Success in opening document
**                   NO      Failure 
**
**
*/

PUBLIC BOOL HTLoadToStream ARGS3(
		CONST char *,	addr,
		BOOL, 		filter,
		HTRequest*,	request)
{
   HTAnchor * anchor = HTAnchor_findAddress(addr);
   request->anchor = HTAnchor_parent(anchor);
   request->childAnchor = ((HTAnchor*)request->anchor == anchor) ? NULL :
   	(HTChildAnchor*) anchor;
    request->output_stream = request->output_stream;
    return HTLoadDocument(request, NO);
}




/*		Load a document from relative name
**		---------------
**
**    On Entry,
**        relative_name     The relative address of the document
**	  		    to be accessed.
**
**    On Exit,
**        returns    YES     Success in opening document
**                   NO      Failure 
**
**
*/

PUBLIC BOOL HTLoadRelative ARGS3(
		CONST char *,		relative_name,
		HTParentAnchor *,	here,
		HTRequest *,		request)
{
    char * 		full_address = 0;
    BOOL       		result;
    char * 		mycopy = 0;
    char * 		stripped = 0;
    char *		current_address =
    				HTAnchor_address((HTAnchor*)here);

    StrAllocCopy(mycopy, relative_name);

    stripped = HTStrip(mycopy);
    full_address = HTParse(stripped,
	           current_address,
		   PARSE_ACCESS|PARSE_HOST|PARSE_PATH|PARSE_PUNCTUATION);
    result = HTLoadAbsolute(full_address, request);
    free(full_address);
    free(current_address);
    free(mycopy);  /* Memory leak fixed 10/7/92 -- JFG */
    return result;
}


/*		Load if necessary, and select an anchor
**		--------------------------------------
**
**    On Entry,
**        destination      	    The child or parenet anchor to be loaded.
**
**    On Exit,
**        returns    YES     Success
**                   NO      Failure 
**
*/

PUBLIC BOOL HTLoadAnchor ARGS2(HTAnchor*, anchor, HTRequest *, request)
{
    if (!anchor) return NO;	/* No link */
    
    request->anchor  = HTAnchor_parent(anchor);
    request->childAnchor = ((HTAnchor*)request->anchor == anchor) ? NULL
    					: (HTChildAnchor*) anchor;
    
    return HTLoadDocument(request, NO) ? YES : NO;
	
} /* HTLoadAnchor */


/*		Load if necessary, and select an anchor
**		--------------------------------------
**
**	This function is almost identical to HTLoadAnchor, but it doesn't
**	clear the error stack so that the information in there is kept.
**
**    On Entry,
**        destination      	    The child or parenet anchor to be loaded.
**
**    On Exit,
**        returns    YES     Success
**                   NO      Failure 
**
*/

PUBLIC BOOL HTLoadAnchorRecursive ARGS2(HTAnchor*, anchor,
					HTRequest *, request)
{
    if (!anchor) return NO;	/* No link */
    
    request->anchor  = HTAnchor_parent(anchor);
    request->childAnchor = ((HTAnchor*)request->anchor == anchor) ? NULL
    					: (HTChildAnchor*) anchor;
    
    return HTLoadDocument(request, YES) ? YES : NO;
	
} /* HTLoadAnchor */


/*		Search
**		------
**  Performs a keyword search on word given by the user. Adds the keyword to 
**  the end of the current address and attempts to open the new address.
**
**  On Entry,
**       *keywords  	space-separated keyword list or similar search list
**	here		is anchor search is to be done on.
*/

PRIVATE char hex(i)
    int i;
{
    char * hexchars = "0123456789ABCDEF";
    return hexchars[i];
}

PUBLIC BOOL HTSearch ARGS3(
	CONST char *, 		keywords,
	HTParentAnchor *, 	here,
	HTRequest *,		request)
{

#define acceptable \
"1234567890abcdefghijlkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_"

    char *q, *u;
    CONST char * p, *s, *e;		/* Pointers into keywords */
    char * address = HTAnchor_address((HTAnchor*)here);
    BOOL result;
    char * escaped = malloc(strlen(keywords)*3+1);

    /* static CONST BOOL isAcceptable[96] = */
    /* static AND const is not good for a gnu compiler! Frystyk 25/02-94 */
    static BOOL isAcceptable[96] =
    /*   0 1 2 3 4 5 6 7 8 9 A B C D E F */
    {    0,0,0,0,0,0,0,0,0,0,1,0,0,1,1,0,	/* 2x   !"#$%&'()*+,-./	 */
         1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,	/* 3x  0123456789:;<=>?	 */
	 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,	/* 4x  @ABCDEFGHIJKLMNO  */
	 1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,1,	/* 5X  PQRSTUVWXYZ[\]^_	 */
	 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,	/* 6x  `abcdefghijklmno	 */
	 1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0 };	/* 7X  pqrstuvwxyz{\}~	DEL */

    if (escaped == NULL) outofmem(__FILE__, "HTSearch");
    
/* Convert spaces to + and hex escape unacceptable characters */

    for(s=keywords; *s && WHITE(*s); s++); /*scan */ 	 /* Skip white space */
    for(e = s + strlen(s); e>s && WHITE(*(e-1)) ; e--);     /* Skip trailers */
    for(q=escaped, p=s; p<e; p++) {		      /* scan stripped field */
        int c = (int)TOASCII(*p);
        if (WHITE(*p)) {
	    *q++ = '+';
	} else if (c>=32 && c<=127 && isAcceptable[c-32] != 0) {
	    *q++ = *p;			/* 930706 TBL for MVS bug */
	} else {
	    *q++ = '%';
	    *q++ = hex(c / 16);
	    *q++ = hex(c % 16);
	}
    } /* Loop over string */
    
    *q=0;
    				/* terminate escaped sctring */
    u=strchr(address, '?');		/* Find old search string */
    if (u) *u = 0;			        /* Chop old search off */

    StrAllocCat(address, "?");
    StrAllocCat(address, escaped);
    free(escaped);
    result = HTLoadRelative(address, here, request);
    free(address);
    
    return result;
}


/*		Search Given Indexname
**		------
**  Performs a keyword search on word given by the user. Adds the keyword to 
**  the end of the current address and attempts to open the new address.
**
**  On Entry,
**       *keywords  	space-separated keyword list or similar search list
**	*addres		is name of object search is to be done on.
*/

PUBLIC BOOL HTSearchAbsolute ARGS3(
	CONST char *, 	keywords,
	CONST char *, 	indexname,
	HTRequest *,	request)
{
    HTParentAnchor * anchor =
    	(HTParentAnchor*) HTAnchor_findAddress(indexname);
    return HTSearch(keywords, anchor, request);
}


/*		Generate the anchor for the home page
**		-------------------------------------
**
**	As it involves file access, this should only be done once
**	when the program first runs.
**	This is a default algorithm -- browser don't HAVE to use this.
**	But consistency betwen browsers is STRONGLY recommended!
**
**	Priority order is:
**
**		1	WWW_HOME environment variable (logical name, etc)
**		2	~/WWW/default.html
**		3	/usr/local/bin/default.html
**		4	http://info.cern.ch/default.html
**
*/
PUBLIC HTParentAnchor * HTHomeAnchor NOARGS
{
    char * my_home_document = NULL;
    char * home = (char *)getenv(LOGICAL_DEFAULT);
    char * ref;
    HTParentAnchor * anchor;
    
    if (home) {
        StrAllocCopy(my_home_document, home);
    
/* 	Someone telnets in, they get a special home.
*/
#define MAX_FILE_NAME 1024					/* @@@ */
    } else  if (HTClientHost) {			/* Telnet server */
    	FILE * fp = fopen(REMOTE_POINTER, "r");
	char * status;
	if (fp) {
	    my_home_document = (char*) malloc(MAX_FILE_NAME);
	    status = fgets(my_home_document, MAX_FILE_NAME, fp);
	    if (!status) {
	        free(my_home_document);
		my_home_document = NULL;
	    }
	    fclose(fp);
	}
	if (!my_home_document) StrAllocCopy(my_home_document, REMOTE_ADDRESS);
    }

    

#ifdef unix

    if (!my_home_document) {
	FILE * fp = NULL;
	CONST char * home =  (CONST char*)getenv("HOME");
	if (home) { 
	    my_home_document = (char *)malloc(
		strlen(home)+1+ strlen(PERSONAL_DEFAULT)+1);
	    if (my_home_document == NULL) outofmem(__FILE__, "HTLocalName");
	    sprintf(my_home_document, "%s/%s", home, PERSONAL_DEFAULT);
	    fp = fopen(my_home_document, "r");
	}
	
	if (!fp) {
	    StrAllocCopy(my_home_document, LOCAL_DEFAULT_FILE);
	    fp = fopen(my_home_document, "r");
	}
	if (fp) {
	    fclose(fp);
	} else {
	if (TRACE) fprintf(stderr,
	    "HTBrowse: No local home document ~/%s or %s\n",
	    PERSONAL_DEFAULT, LOCAL_DEFAULT_FILE);
	    free(my_home_document);
	    my_home_document = NULL;
	}
    }
#endif
    ref = HTParse( my_home_document ?	my_home_document :
				HTClientHost ? REMOTE_ADDRESS
				: LAST_RESORT,
		    "file:",
		    PARSE_ACCESS|PARSE_HOST|PARSE_PATH|PARSE_PUNCTUATION);
    if (my_home_document) {
	if (TRACE) fprintf(stderr,
	    "HTAccess: Using custom home page %s i.e. address %s\n",
	    my_home_document, ref);
	free(my_home_document);
    }
    anchor = (HTParentAnchor*) HTAnchor_findAddress(ref);
    free(ref);
    return anchor;
}


/*		Bind an Anchor to the request structure
**		---------------------------------------
**
**    On Entry,
**	anchor		The child or parenet anchor to be binded
**	request		The request sturcture
**    On Exit,
**        returns    YES     Success
**                   NO      Failure 
**
**  Note: Actually the same as HTLoadAnchor() but DOES NOT do the loading
**						Henrik Frystyk 17/02-94
*/

PUBLIC BOOL HTBindAnchor ARGS2(HTAnchor*, anchor, HTRequest *, request)
{
    if (!anchor) return NO;	/* No link */
    
    request->anchor  = HTAnchor_parent(anchor);
    request->childAnchor = ((HTAnchor*)request->anchor == anchor) ? NULL
    					: (HTChildAnchor*) anchor;
	
    return YES;
} /* HTBindAnchor */