// vim:foldmethod=marker:syntax=lpc:noexpandtab
// $Id: circuit.c,v 1.38 2008/10/14 19:02:29 lynx Exp $

#include "psyc.h"

#include <net.h>
#include <uniform.h>
#include <tls.h>
#include <text.h>

inherit NET_PATH "trust";
inherit NET_PATH "spyc/parse";
virtual inherit NET_PATH "output";

volatile string peerhost;
volatile string peeraddr;
volatile string peerip;
volatile int peerport;

volatile string netloc;

#ifndef NEW_RENDER
# define NEW_RENDER
#endif
#include "render.i"

// this is completely anti-psyc. it should take mcs as arguments
// and look up the actual message from textdb.. FIXME
#define CIRCUITERROR(reason) { \
                             croak("_error_circuit", "circuit error: "         \
                                    reason);                                   \
                             return 0;                                         \
                           }
                            
mapping instate = ([ ]);
mapping outstate;

mapping legal_senders;


volatile int flags = 0;

void circuit_msg(string mc, mapping vars, string data); // prototype
varargs int msg(string source, string mc, string data,
    mapping vars, int showingLog, mixed target); // prototype
protected void quit();	// prototype
void runQ();

int isServer() { return 0; }

void peek(string data) {
#if __EFUN_DEFINED__(enable_binary)
    enable_binary(ME);
#else
    raise_error("Driver compiled without enable_binary()");
#endif
}

void feed(string data) {
    input_to(#'feed, INPUT_IGNORE_BANG);
    ::feed(data);
}

// yes, this is a funny implementation of croak
// it does not use msg(). Yes, that is intended
varargs mixed croak(string mc, string data, vamapping vars, vamixed source) {
    PT(("croak(%O) in %O (%O)\n", mc, ME, query_ip_name()))
    unless (data) data = T(mc, "");
    binary_message(sprintf("\n%s\n%s\n|\n", mc, data));
    // right behaviour for all croaks!?
    remove_interactive(ME);
//  destruct(ME);
    return 0;
}

#ifdef USE_VERIFICATION
// request sender authentication and/or target acknowledgement 
// from the remote side
void sender_verification(array(string) sourcehosts, array(string) targethosts)
{
    // FIXME: wrong variables here
    mapping vars = ([ "_list_sources_hosts" : sourcehosts,
		    "_list_targets_hosts" : targethosts,
		    "_tag" : RANDHEXSTRING ]);
    // assumption: we have already resolved all targethosts and 
    // they point to the remote ip
    foreach(string ho : targethosts) {
	sAuthenticated(ho);
    }

    msg(0, "_request_verification", 0, vars);
}
#endif

// gets called during socket logon
int logon(int failure) {
    sAuthHosts(([ ])); // reset authhosts 
    legal_senders = ([ ]);
    instate = ([ "_INTERNAL_origin" : ME ]);
    outstate = ([ ]);
#ifdef __TLS__
    mixed cert;
    if (tls_available() && tls_query_connection_state(ME) == 1 && mappingp(cert = tls_certificate(ME, 0))) {
	mixed m, t;
	if (cert[0] != 0) {
	    // log error 17 + cert here
	    // and goodbye.
	    P0(("%O encountered a cert verify error %O in %O\n", ME,
		cert[0], cert))
	    remove_interactive(ME);
	    return 0;
	}
	if (m = cert["2.5.29.17:dNSName"]) {
	    // FIXME: this does not yet handle wildcard DNS names
	    P1(("%O believing dNSName %O\n", ME, m))
	    // probably also: register_target?
	    // but be careful never to register_target wildcards
	    if (stringp(m)) 
		sAuthenticated(NAMEPREP(m));
	    else 
		foreach(t : m) 
		    sAuthenticated(NAMEPREP(t));
	}
//#ifdef _flag_allow_certificate_name_common	// to be switched this year
#ifndef _flag_disallow_certificate_name_common
	// assume that CN is a host
	// as this is an assumption only, we may NEVER register_target it
	// note: CN is deprecated for good reasons.
	else if (t = cert["2.5.4.3"]) {
	    P1(("%O believing CN %O\n", ME, t))
	    sAuthenticated(NAMEPREP(t));
	}
#endif
	if (m = tls_query_connection_info(ME)) {
	    P2(("%O is using the %O cipher.\n", ME, m[TLS_CIPHER]))
	    // shouldn't our negotiation have ensured we have PFS?
	    if (stringp(t = m[TLS_CIPHER]) &&! abbrev("DHE", t)) {
//			croak("_warning_circuit_encryption_cipher",
//			"Your cipher choice does not provide forward secrecy.");
		monitor_report(
		    "_warning_circuit_encryption_cipher_details",
		    object_name(ME) +" · using "+ t +" cipher");
		//debug_message(sprintf(
		//  "TLS connection info for %O is %O\n", ME, m));
		//QUIT	// are we ready for *this* !???
	    }
	}
    }
#endif

    peerip = query_ip_number(ME) || "127.0.0.1";

    input_to(#'feed, INPUT_IGNORE_BANG);
    
    call_out(#'quit, 90);
    flags = TCP_PENDING_TIMEOUT;

    parser_init();

    // FIXME
    unless(isServer()) {
	emit("|\n"); // initial greeting
#ifdef USE_FEATURES
	// we have no features to request or offer
	msg(0, "_request_features", 0);
#else
# ifdef USE_VERIFICATION
	// start hostname verification
	// rather: look at Q and look for the hostnames we need
	sender_verification(({ SERVER_HOST }), ({ peerhost }));
# else
	if (function_exists("runQ")) {
	    runQ();
	}
# endif
#endif
    }
    return 1;
}

int disconnected(string remaining) {
	// i love to copy+paste source codes! thx for NOT sharing.. grrr
#if DEBUG > 0
	if (remaining && (!stringp(remaining) || strlen(remaining)))
	    PP(("%O ignoring remaining data from socket: %O\n", ME,
		remaining));
#endif
	// wow.. a sincerely expected disconnect!
	if (flags & TCP_PENDING_DISCONNECT) return 1;
#ifdef _flag_enable_report_failure_network_circuit_disconnect
	monitor_report("_failure_network_circuit_disconnect",
	    object_name(ME) +" · lost PSYC circuit");
#else
	P1(("%O disconnected unexpectedly\n", ME))
#endif
        return 0;   // unexpected

}

// respond to the first empty packet
first_response() {
    emit("|\n");
}

#define PSYC_TCP
#include "dispatch.i"

// receives a msg from the remote side
// note: this is circuit-messaging
void circuit_msg(string mc, mapping vars, string data) {
    switch(mc) {
    case "_request_verification":
	if (tls_query_connection_state(ME) == 0) {
	    array(string) targethosts = ({ });
	    foreach(string ho : vars["_list_targets_hosts"]) {
		if (is_localhost(lower_case(ho))) {
		    targethosts += ({ ho });
		}
	    }
	    if (sizeof(vars["_list_sources_hosts"]) == 1) {
		// doing multiple resolutions in parallel is more complicated
		string ho = vars["_list_sources_hosts"][0];
		if (qAuthenticated(ho)) {
		    P0(("warning: trying to reverify authenticated host %O",ho))
		} else {
		    dns_resolve(ho, (: 
			// FIXME: psyc/parse::deliver is much better here
			mixed rv = (["_list_targets_accepted_hosts":targethosts]);

			if (vars["_tag"]) rv["_tag_reply"] = vars["_tag"];
			if ($1 == peerip) {
			    sAuthenticated(NAMEPREP(ho));
			    rv["_list_sources_verified_hosts"] = ({ ho });
			} else {
			    rv["_list_sources_rejected_hosts"] = ({ ho });
			}
			msg(0, "_notice_verification", 0, rv);
			return;
		    :));
		}
	    } else {
		// FIXME!!!!
		CIRCUITERROR("sorry, no more than one element in _list_sources_hosts currently");
		P0(("more than one element in _list_sources_hosts: %O\n", vars["_list_sources_hosts"]))
	    }
	    // keep tag if present!!!
	    // resolve all of _list_sources_hosts
	    // look at _list_targets_hosts and determine localhostiness
	} else {
	    CIRCUITERROR("_request_verification is not allowed on TLS circuits.");
	}
	break;
    case "_notice_features":
	// FIXME: watch for _list_using_modules
	if (flags & TCP_PENDING_TIMEOUT) {
	    P0(("removing call out\n"))
	    remove_call_out(#'quit);
	    flags -= TCP_PENDING_TIMEOUT;
	}
	sTextPath();
#ifdef USE_FEATURES
	if (tls_query_connection_state(ME) == 0) {
# ifdef USE_VERIFICATION
	    // start hostname verification
	    // rather: look at Q and look for the hostnames we need
	    sender_verification(({ SERVER_HOST }), ({ peerhost }));
# endif
	} else {
	    if (function_exists("runQ")) {
		runQ();
	    }
	}
#endif
	break;
    case "_notice_verification":	
	P0(("_notice verification with %O\n", vars))
	if (function_exists("runQ")) {
	    runQ();
	}
	break;
    default:
	P0(("%O got circuit_msg %O, not implemented\n", ME, mc))
	break;
    }
}

// delivers a message to the remote side
varargs int msg(string source, string mc, string data,
    mapping vars, int showingLog, mixed target) {

    string buf = "";

    unless(vars) vars = ([ ]);
    buf = render_psyc(source, mc, data, vars, showingLog, target);
#ifdef _flag_log_sockets_SPYC
    log_file("RAW_SPYC", "« %O\n%s\n", ME, buf);
#endif
    return emit(buf);
}