/*								     HTProxy.c**	GATEWAY AND PROXY MANAGER****	(c) COPYRIGHT MIT 1995.**	Please first read the full copyright statement in the file COPYRIGH.**	@(#) $Id: HTProxy.c,v 2.21 2000/02/29 14:25:59 kahan Exp $****	Replaces the old env variables for gateways and proxies. However for**	backward compatibility there is a function that reads the env variables**	at start up. Note that there is a difference between a proxy and a**	gateway!**** Authors**	HF	Henrik Frystyk, frystyk@w3.org** History**       4 Jun 95 Written on a rainy day*/#if !defined(HT_DIRECT_WAIS) && !defined(HT_DEFAULT_WAIS_GATEWAY)#define HT_DEFAULT_WAIS_GATEWAY "http://www.w3.org:8001/"#endif/* Library include files */#include "wwwsys.h"#include "WWWUtil.h"#include "WWWCore.h"#include "WWWHTTP.h"#include "WWWApp.h"#include "HTProxy.h"					 /* Implemented here *//* Variables and typedefs local to this module */typedef struct _HTProxy {    char *	access;    char *	url;			          /* URL of Gateway or Proxy */#ifdef HT_POSIX_REGEX    regex_t *	regex;				  /* Compiled regex */#endif} HTProxy;typedef struct _HTHostlist {    char *	access;    char *	host;				  /* Host or domain name */    unsigned	port;#ifdef HT_POSIX_REGEX    regex_t *	regex;				  /* Compiled regex */#endif} HTHostList;PRIVATE HTList * proxies = NULL;		    /* List of proxy servers */PRIVATE HTList * gateways = NULL;			 /* List of gateways */PRIVATE HTList * noproxy = NULL;   /* Don't proxy on these hosts and domains */PRIVATE int      noproxy_is_onlyproxy = 0; /* Interpret the noproxy list as an onlyproxy one */#if 0PRIVATE HTList * onlyproxy = NULL;  /* Proxy only on these hosts and domains */#endif/* ------------------------------------------------------------------------- */#ifdef HT_POSIX_REGEXPRIVATE char * get_regex_error (int errcode, regex_t * compiled){    size_t length = regerror (errcode, compiled, NULL, 0);    char * str = NULL;    if ((str = (char *) HT_MALLOC(length+1)) == NULL)	HT_OUTOFMEM("get_regex_error");    (void) regerror (errcode, compiled, str, length);    return str;}PRIVATE regex_t * get_regex_t (const char * regex_str, int cflags){    regex_t * regex = NULL;    if (regex_str && *regex_str) {	int status;	if ((regex = (regex_t *) HT_CALLOC(1, sizeof(regex_t))) == NULL)	    HT_OUTOFMEM("get_regex_t");	if ((status = regcomp(regex, regex_str, cflags))) {	    char * err_msg = get_regex_error(status, regex);	    HTTRACE(PROT_TRACE, "HTProxy..... Regular expression error: %s\n" _ err_msg);	    HT_FREE(err_msg);	    HT_FREE(regex);	}    }    return regex;}#endif/***	Existing entries are replaced with new ones*/PRIVATE BOOL add_object (HTList * list, const char * access, const char * url,			 BOOL regex, int regex_flags){    HTProxy *me;    if (!list || !access || !url || !*url)	return NO;    if ((me = (HTProxy *) HT_CALLOC(1, sizeof(HTProxy))) == NULL)	HT_OUTOFMEM("add_object");    StrAllocCopy(me->access, access);		     	    /* Access method */#ifdef HT_POSIX_REGEX    /*     **  If we support regular expressions then compile one up for    **  this regular expression. Otherwise use is as a normal    **  access scheme.    */    if (regex) {	me->regex = get_regex_t(access,				regex_flags < 0 ?				W3C_DEFAULT_REGEX_FLAGS : regex_flags);    } else#endif    {	char *ptr = me->access;	while ((*ptr = TOLOWER(*ptr))) ptr++;    }    me->url = HTParse(url, "", PARSE_ACCESS+PARSE_HOST+PARSE_PUNCTUATION);    if (*(me->url+strlen(me->url)-1) != '/')	StrAllocCat(me->url, "/");    me->url = HTSimplify(&me->url);    /* See if we already have this one */    {	HTList *cur = list;	HTProxy *pres;	while ((pres = (HTProxy *) HTList_nextObject(cur)) != NULL) {	    if (!strcmp(pres->access, me->access))		break;				       /* We already have it */	}	if (pres) {	    HTTRACE(PROT_TRACE, "HTProxy..... replacing for `%s\' access %s\n" _ 			me->url _ me->access);	    HT_FREE(pres->access);	    HT_FREE(pres->url);#ifdef HT_POSIX_REGEX	    if (pres->regex) regfree(pres->regex);#endif	    HTList_removeObject(list, (void *) pres);	    HT_FREE(pres);	}	HTTRACE(PROT_TRACE, "HTProxy..... adding for `%s\' access %s\n" _ 		    me->url _ me->access);	HTList_addObject(list, (void *) me);    }    return YES;}PRIVATE BOOL remove_allObjects (HTList * list){    if (list) {	HTList *cur = list;	HTProxy *pres;	while ((pres = (HTProxy *) HTList_nextObject(cur)) != NULL) {	    HT_FREE(pres->access);	    HT_FREE(pres->url);#ifdef HT_POSIX_REGEX	    if (pres->regex) regfree(pres->regex);#endif	    HT_FREE(pres);	}	return YES;    }    return NO;}/*	Add an entry to a list of host names**	------------------------------------**	Existing entries are replaced with new ones*/PRIVATE BOOL add_hostname (HTList * list, const char * host,			   const char * access, unsigned port,			   BOOL regex, int regex_flags){    HTHostList *me;    if (!list || !host || !*host)	return NO;    if ((me = (HTHostList *) HT_CALLOC(1, sizeof(HTHostList))) == NULL)        HT_OUTOFMEM("add_hostname");#ifdef HT_POSIX_REGEX    if (regex)	me->regex = get_regex_t(host,				regex_flags < 0 ?				W3C_DEFAULT_REGEX_FLAGS : regex_flags);#endif    if (access) {	char *ptr;	StrAllocCopy(me->access, access);      	     	    /* Access method */	ptr = me->access;	while ((*ptr = TOLOWER(*ptr))) ptr++;    }    StrAllocCopy(me->host, host);		     	    	/* Host name */    {	char *ptr = me->host;	while ((*ptr = TOLOWER(*ptr))) ptr++;    }    me->port = port;					      /* Port number */    HTTRACE(PROT_TRACE, "HTHostList.. adding `%s\' to list\n" _ me->host);    HTList_addObject(list, (void *) me);    return YES;}PRIVATE BOOL remove_AllHostnames (HTList * list){    if (list) {	HTList *cur = list;	HTHostList *pres;	while ((pres = (HTHostList *) HTList_nextObject(cur)) != NULL) {	    HT_FREE(pres->access);	    HT_FREE(pres->host);#ifdef HT_POSIX_REGEX	    if (pres->regex) regfree(pres->regex);#endif	    HT_FREE(pres);	}	return YES;    }    return NO;}/*	HTProxy_add**	-----------**	Registers a proxy as the server to contact for a specific**	access method. `proxy' should be a fully valid name, like**	"http://proxy.w3.org:8001" but domain name is not required.**	If an entry exists for this access then delete it and use the **	ne one. Returns YES if OK, else NO*/PUBLIC BOOL HTProxy_add (const char * access, const char * proxy){    /*    **  If this is the first time here then also add a before filter to handle    **  proxy authentication and the normal AA after filter as well.    **  These filters will be removed if we remove all proxies again.    */    if (!proxies) {	proxies = HTList_new();	HTNet_addBefore(HTAA_proxyBeforeFilter, NULL, NULL,			HT_FILTER_MIDDLE);	HTNet_addAfter(HTAuthFilter, NULL, NULL,		       HT_NO_PROXY_ACCESS, HT_FILTER_MIDDLE);	HTNet_addAfter(HTAuthFilter, NULL, NULL,		       HT_PROXY_REAUTH, HT_FILTER_MIDDLE);    }    return add_object(proxies, access, proxy, NO, -1);}/*	HTProxy_addRegex**	----------------**	Registers a proxy as the server to contact for any URL matching the**	regular expression. `proxy' should be a fully valid name, like**	"http://proxy.w3.org:8001".**	If an entry exists for this access then delete it and use the **	new one. Returns YES if OK, else NO*/PUBLIC BOOL HTProxy_addRegex (const char * regex,			      const char * proxy,			      int regex_flags){    /*    **  If this is the first time here then also add a before filter to handle    **  proxy authentication and the normal AA after filter as well.    **  These filters will be removed if we remove all proxies again.    */    if (!proxies) {	proxies = HTList_new();	HTNet_addBefore(HTAA_proxyBeforeFilter, NULL, NULL,			HT_FILTER_MIDDLE);	HTNet_addAfter(HTAuthFilter, NULL, NULL,		       HT_NO_PROXY_ACCESS, HT_FILTER_MIDDLE);	HTNet_addAfter(HTAuthFilter, NULL, NULL,		       HT_PROXY_REAUTH, HT_FILTER_MIDDLE);    }#ifdef HT_POSIX_REGEX    return add_object(proxies, regex, proxy, YES, regex_flags);#else    return add_object(proxies, regex, proxy, NO, -1);#endif}/***	Removes all registered proxies*/PUBLIC BOOL HTProxy_deleteAll (void){    if (remove_allObjects(proxies)) {	HTList_delete(proxies);	/*	** If we have no more proxies then there is no reason for checking	** proxy authentication. We therefore unregister the filters for	** handling proxy authentication	*/	HTNet_deleteBefore(HTAA_proxyBeforeFilter);        HTNet_deleteAfterStatus(HT_NO_PROXY_ACCESS);        HTNet_deleteAfterStatus(HT_PROXY_REAUTH);	proxies = NULL;	return YES;    }    return NO;}