The main thing to understand about the proxy gateway is that instead of a
partial URL being sent to the HTTP server, which is what we do today when a
client talks directly to an HTTP server, a client must send a full URL
(http://..., gopher://..., ftp://...) to the proxy gateway server, the rest
of the HTTP message is the same. For gopher and ftp, the proxy gateway
server will return the data encapsulated as a MIME content type to the
client like a normal HTTP message. HTTP MIME content types are returned for
all URL requests, regardless of the protocol type of the URL. FTP
directories, Gopher directories, etc. are returned as text/html.
ka
---From: [email protected] (Lou Montulli) Subject: Re: Firewall gateway solution, exodus Date: Tue, 1 Feb 94 19:05:06 CST
Per our earlier discussions about using <protocal>_proxy as the environment variables I have some new diffs:
This solution will only work with HTTP gateways. These diffs apply to libWWW 2.14
falcon.cc.ukans.edu> diff ../WWW2.14/Lib*/I*/HTAccess.c WWW/L*/I*/HTAccess.c 54a55 > PUBLIC BOOL using_proxy = NO; /* are we using a proxy gateway? */ 155c156,158 < char * gateway_parameter, *gateway;
--- > char * gateway_parameter, *gateway, *proxy; > > /* search for gateways */ 161a165,169 > > /* search for proxy servers */ > strcpy(gateway_parameter, access); > strcat(gateway_parameter, "_proxy"); > proxy = (char *)getenv(gateway_parameter); 162a171,175 > > if(TRACE && gateway) > fprintf(stderr,"Gateway found: %s\n",gateway); > if(TRACE && proxy) > fprintf(stderr,"proxy server found: %s\n",proxy); 169c182,199 < if (gateway) {--- > > /* make sure the using_proxy variable is false */ > using_proxy = NO; > > /* proxy servers have precedence over gateway servers */ > if(proxy) { > char * gatewayed=0; > StrAllocCopy(gatewayed,proxy); > StrAllocCat(gatewayed,addr); > using_proxy = YES; > HTAnchor_setPhysical(anchor, gatewayed); > free(gatewayed); > free(access); > > access = HTParse(HTAnchor_physical(anchor), > "http:", PARSE_ACCESS); > > } else if (gateway) {
I replaced the libWWW version of HTTP.c with Xmosaic's version and started changing, so rather than giving diffs I'll just describe the changes. :)
add this to define the global variable: extern BOOL using_proxy; /* are we using an HTTP proxy gateway? */
add this to remove the first character of the resulting path. This is done because the resulting URL of the gateway change in HTAccess causes something like these to appear: gopher://gopher.host/path">http://gateway.host/gopher://gopher.host/path wais://wais.host/path">http://gateway.host/wais://wais.host/path http://gateway.host/http://http.host/path
The protocol and host is stripped by the time we reach the variable p1 below, by the statement: char * p1 = HTParse(arg, "", PARSE_PATH|PARSE_PUNCTUATION); so we end up with: /gopher://gopher.host/path /wais://wais.host/path /http://http.host/path
and we want to send: gopher://gopher.host/path wais://wais.host/path http://http.host/path
/* if we are using a proxy gateway don't copy in the first slash * of say: /gopher://a;lkdjfl;ajdf;lkj/;aldk/adflj * so that just gohper://.... is sent. */ if(using_proxy) strcat(command, p1+1); else strcat(command, p1);
That should do it. Now when a gateway definition is used that gateway should be sent the entire URL of the requested document.
:lou
-- ************************************************************************** * T H E U N I V E R S I T Y O F K A N S A S * * Lou MONTULLI @ Ukanaix.cc.ukans.edu * * Kuhub.cc.ukans.edu ACS Computing Services * * 913/864-0436 Ukanvax.bitnet Lawrence, KS 66044 * * UNIX! Cool! I know that! Jurassic Park - The Movie * **************************************************************************