/*****************************************************************************
 *
 * $Id$
 * Purpose ...............: Netmail tracker / router
 *
 *****************************************************************************
 * Copyright (C) 1997-2005
 *   
 * Michiel Broek		FIDO:		2:280/2802
 * Beekmansbos 10
 * 1971 BV IJmuiden
 * the Netherlands
 *
 * This file is part of MBSE BBS.
 *
 * This BBS is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * MBSE BBS is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with MBSE BBS; see the file COPYING.  If not, write to the Free
 * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *****************************************************************************/

#include "../config.h"
#include "../lib/mbselib.h"
#include "../lib/users.h"
#include "../lib/nodelist.h"
#include "../lib/mbsedb.h"
#include "tracker.h"


extern char	nodes_fil[81];
extern long	nodes_pos;

/*
 * Internal prototypes
 */
void ParseMask(char *, fidoaddr *);
char *get_routetype(int);
int  GetTableRoute(char *, fidoaddr *);
int  IsLocal(char *, fidoaddr *);
int  GetRoute(char *, fidoaddr *);
int  AreWeHost(faddr *);
int  AreWeHub(faddr *);



/*
 * Parse the mask from the routing table. If all 4d address parts
 * are 0, then something is wrong. This cannot happen because the
 * syntax is checked in mbsetup.
 * Matched values return the actual value, the "All" masks return 65535.
 */
void ParseMask(char *s, fidoaddr *addr)
{
    char	    *buf, *str, *p;
    int		    good = TRUE;

    memset(addr, 0, sizeof(fidoaddr));

    if (s == NULL)
	return;

    str = buf = xstrcpy(s);

    addr->zone = 65535;
    if ((p = strchr(str, ':'))) {
	*(p++) = '\0';
	if (strspn(str, "0123456789") == strlen(str))
	    addr->zone = atoi(str);
	else
	    if (strcmp(str,"All"))
		good = FALSE;
	str = p;
    }

    addr->net = 65535;
    if ((p = strchr(str, '/'))) {
	*(p++) = '\0';
	if (strspn(str, "0123456789") == strlen(str))
	    addr->net = atoi(str);
	else 
	    if (strcmp(str, "All"))
		good = FALSE;
	    str = p;
    }

    if ((p=strchr(str, '.'))) {
	*(p++) = '\0';
	if (strspn(str, "0123456789") == strlen(str))
	    addr->node = atoi(str);
	else 
	    if (strcmp(str, "All") == 0)
		addr->node = 65535;
	    else 
		good = FALSE;
	    str = p;
    } else {
	if (strspn(str, "0123456789") == strlen(str))
	    addr->node = atoi(str);
	else 
	    if (strcmp(str, "All") == 0)
		addr->node = 65535;
	    else 
		good = FALSE;
	    str = NULL;
    }

    if (str) {
	if (strspn(str, "0123456789") == strlen(str))
	    addr->point = atoi(str);
	else 
	    if (strcmp(str, "All") == 0)
		addr->point = 65535;
	    else 
		good = FALSE;
    }

    if (buf)
	free(buf);

    if (!good) {
	addr->zone  = 0;
	addr->net   = 0;
	addr->node  = 0;
	addr->point = 0;
    }

    return;
}



char *get_routetype(int val)
{
    switch (val) {
	case R_NOROUTE:     return (char *)"Default route";
	case R_ROUTE:       return (char *)"Route to";
	case R_DIRECT:      return (char *)"Direct";
	case R_REDIRECT:    return (char *)"New address";
	case R_BOUNCE:      return (char *)"Bounce";
	case R_CC:          return (char *)"CarbonCopy ";
	case R_LOCAL:	    return (char *)"Local aka";
	case R_UNLISTED:    return (char *)"Unlisted";
	default:            return (char *)"Internal error";
    }
}



int GetTableRoute(char *ftn, fidoaddr *res)
{
    char	*temp;
    faddr	*dest;
    fidoaddr	mask;
    int		match, last;
    long	ptr;
    FILE	*fil;

    /*
     * Check routing table
     */
    temp = calloc(PATH_MAX, sizeof(char));
    sprintf(temp, "%s/etc/route.data", getenv("MBSE_ROOT"));
    if ((fil = fopen(temp, "r")) == NULL) {
	free(temp);
	return R_NOROUTE;
    }
    free(temp);
    fread(&routehdr, sizeof(routehdr), 1, fil);

    memset(res, 0, sizeof(fidoaddr));
    dest = parsefnode(ftn);
    if (SearchFidonet(dest->zone)) {
	if (dest->domain)
	    free(dest->domain);
	dest->domain = xstrcpy(fidonet.domain);
    }
    Syslog('r', "Get table route for: %s", ascfnode(dest, 0xff));

    match = last = METRIC_MAX;
    ptr = ftell(fil);

    while (fread(&route, routehdr.recsize, 1, fil) == 1) {
        if (route.Active) {
            ParseMask(route.mask, &mask);
            Syslog('r', "Table %s (%s) => %s", route.mask, get_routetype(route.routetype), aka2str(route.dest));
            match = METRIC_MAX;
            if (mask.zone) {
                if ((mask.zone == 65535) || (mask.zone == dest->zone)) {
                    match = METRIC_ZONE;
                    if ((mask.net == 65535) || (mask.net == dest->net)) {
                        match = METRIC_NET;
                        if ((mask.node == 65535) || (mask.node == dest->node)) {
                            match = METRIC_NODE;
                            if ((mask.point == 65535) || (mask.point == dest->point))
                                match = METRIC_POINT;
                        }
                    }
                }
                if (match < last) {
                    Syslog('r', "Best util now");
                    last = match;
                    ptr = ftell(fil) - routehdr.recsize;
                }
            } else {
                Syslog('!', "Warning, internal error in routing table");
            }
        }
    }
    tidy_faddr(dest);

    if (last < METRIC_MAX) {
        fseek(fil, ptr, SEEK_SET);
        fread(&route, routehdr.recsize, 1, fil);
        fclose(fil);
        Syslog('r', "Route selected %s %s %s", route.mask, get_routetype(route.routetype), aka2str(route.dest));
	memcpy(res, &route.dest, sizeof(fidoaddr));
	return route.routetype;
    }

    fclose(fil);
    return R_NOROUTE;
}



/*
 * Check if destination is one of our local aka's
 */
int IsLocal(char *ftn, fidoaddr *res)
{
    faddr   *dest;
    int	    i;

    memset(res, 0, sizeof(fidoaddr));
    dest = parsefnode(ftn);
    if (SearchFidonet(dest->zone)) {
	if (dest->domain)
	    free(dest->domain);
	dest->domain = xstrcpy(fidonet.domain);
    }
    Syslog('r', "Check local aka for: %s", ascfnode(dest, 0xff));

    /*
     * Check if the destination is ourself.
     */
    for (i = 0; i < 40; i++) {
	if (CFG.akavalid[i] && (CFG.aka[i].zone == dest->zone) && (CFG.aka[i].net == dest->net) && 
	    (CFG.aka[i].node == dest->node) && (dest->point == CFG.aka[i].point)) {
	    Syslog('+', "R: %s => Loc %s", ascfnode(dest, 0x0f), aka2str(CFG.aka[i]));
	    memcpy(res, &CFG.aka[i], sizeof(fidoaddr));
	    tidy_faddr(dest);
	    return R_LOCAL;
	}
    }

    tidy_faddr(dest);
    return R_NOROUTE;
}



/*
 *  Netmail tracker. Return TRUE if we found a valid route.
 *  If we did find a route, it is returned in the route pointer.
 *  If not, return FALSE. The calling program must bounce the
 *  original message.
 */
int TrackMail(fidoaddr too, fidoaddr *routeto)
{
    int	rc, i;
    char    *tstr;

    Syslog('r', "Tracking destination to %s", aka2str(too));

    /*
     * Check for local destination
     */
    rc = IsLocal(aka2str(too) , routeto);
    if (rc == R_LOCAL) {
	// FIXME: When R_CC implemented check table for Cc:
	return rc;
    }

    /*
     * Check route table
     */
    tstr = xstrcpy(aka2str(too));
    rc = GetTableRoute(aka2str(too), routeto);
    if (rc != R_NOROUTE) {
	Syslog('+', "R: %s Routing table: %s => %s", tstr, get_routetype(rc), aka2str(*routeto));
	free(tstr);
	return rc;
    }
    free(tstr);

    /*
     * If no descision yet, get default routing
     */
    rc = GetRoute(aka2str(too) , routeto);
    if (rc == R_NOROUTE) {
	WriteError("No route to %s, not parsed", aka2str(too));
	return R_NOROUTE;
    }
    if (rc == R_UNLISTED) {
	WriteError("No route to %s, unlisted node", aka2str(too));
	return R_UNLISTED;
    }

    /*
     *  Now look again if from the routing result we find a
     *  direct link. If so, maybe adjust something.
     */
    if (SearchNode(*routeto)) {
	Syslog('r', "Node is in setup: %s", aka2str(nodes.Aka[0]));
	if (nodes.RouteVia.zone) {
	    Syslog('r', "Using RouteVia address %s", aka2str(nodes.RouteVia));
	    routeto->zone  = nodes.RouteVia.zone;
	    routeto->net   = nodes.RouteVia.net;
	    routeto->node  = nodes.RouteVia.node;
	    routeto->point = nodes.RouteVia.point;
	    sprintf(routeto->domain, "%s", nodes.RouteVia.domain);
	} else {
	    for (i = 0; i < 20; i++)
		if (routeto->zone == nodes.Aka[i].zone)
		    break;
	    routeto->zone  = nodes.Aka[i].zone;
	    routeto->net   = nodes.Aka[i].net;
	    routeto->node  = nodes.Aka[i].node;
	    routeto->point = nodes.Aka[i].point;
	    sprintf(routeto->domain, "%s", nodes.Aka[i].domain);
	}
	Syslog('r', "Final routing to: %s", aka2str(*routeto));
	return R_ROUTE;
    }

    return rc;
}



int AreWeHost(faddr *dest)
{
    int	i, j;

    /*
     * First a fast run in our own zone.
     */
    for (i = 0; i < 40; i++)
	if (CFG.akavalid[i] && (CFG.aka[i].zone == dest->zone))
	    if (CFG.aka[i].node == 0)
		return i;

    for (i = 0; i < 40; i++)
	if (CFG.akavalid[i])
	    if (SearchFidonet(dest->zone))
		for (j = 0; j < 6; j++)
		    if (CFG.aka[i].zone == fidonet.zone[j])
			if (CFG.aka[i].node == 0)
			    return i;

    return -1;
}



int AreWeHub(faddr *dest)
{
    int	    i, j;
    node    *nl;
    faddr   *fido;

    for (i = 0; i < 40; i++)
	if (CFG.akavalid[i])
	    if (CFG.aka[i].zone == dest->zone) {
		fido = fido2faddr(CFG.aka[i]);
		nl = getnlent(fido);
		tidy_faddr(fido);
		if (nl->addr.domain)
		    free(nl->addr.domain);
		if (nl->type == NL_HUB)
		    return i;
	    }

    for (i = 0; i < 40; i++)
	if (CFG.akavalid[i])
	    if (SearchFidonet(dest->zone))
		for (j = 0; j < 6; j++)
		    if (CFG.aka[i].zone == fidonet.zone[j]) {
			fido = fido2faddr(CFG.aka[i]);
			nl = getnlent(fido);
			tidy_faddr(fido);
			if (nl->addr.domain)
			    free(nl->addr.domain);
			if (nl->type == NL_HUB)
			    return i;
		    }

    return -1;
}



/*
 * Get routing information for specified netmail address.
 */
int GetRoute(char *ftn, fidoaddr *res)
{
    node	    *dnlent, *bnlent;
    unsigned short  myregion;
    faddr	    *dest, *best, *maddr;
    fidoaddr	    *fido, dir;
    int		    me_host = -1, me_hub = -1, i;
    FILE	    *fil;

    memset(res, 0, sizeof(fidoaddr));
    dest = parsefnode(ftn);
    if (SearchFidonet(dest->zone)) {
	if (dest->domain)
	    free(dest->domain);
	dest->domain = xstrcpy(fidonet.domain);
    }
    best = bestaka_s(dest);
    Syslog('r', "Get def. route for : %s", ascfnode(dest, 0xff));
    Syslog('r', "Our best aka is    : %s", ascfnode(best, 0xff));

    /*
     * Check if the destination our point.
     */
    for (i = 0; i < 40; i++) {
	if (CFG.akavalid[i] && 
		    (CFG.aka[i].zone == dest->zone) && (CFG.aka[i].net == dest->net) && (CFG.aka[i].node == dest->node)) {
	    if (dest->point && (!CFG.aka[i].point)) {
		Syslog('+', "R: %s => My point", ascfnode(dest, 0xff));
		fido = faddr2fido(dest);
		memcpy(res, fido, sizeof(fidoaddr));
		free(fido);
		tidy_faddr(best);
		tidy_faddr(dest);
		return R_DIRECT;
	    }
	}
    }

    if (best->point) {
        /*
	 *  We are a point, so don't bother the rest of the tests, route
         *  to our boss.
         */
	Syslog('r', "We are a point");
        res->zone = best->zone;
        res->net  = best->net;
        res->node = best->node;
        res->point = 0;
        Syslog('+', "R: %s => My boss %s", ascfnode(dest, 0x0f), aka2str(*res));
        tidy_faddr(best);
        tidy_faddr(dest);
        return R_DIRECT;
    }

    /*
     * Now test several possible setup matches.
     */
    dir.zone  = dest->zone;
    dir.net   = dest->net;
    dir.node  = dest->node;
    dir.point = dest->point;
    sprintf(dir.domain, "%s", dest->domain);

    /*
     * First direct match
     */
    Syslog('r', "Checking for a direct link, 4d");
    if (SearchNode(dir)) {
	for (i = 0; i < 20; i++) {
	    if ((dir.zone  == nodes.Aka[i].zone) && (dir.node  == nodes.Aka[i].node) &&
		(dir.net   == nodes.Aka[i].net) && (dir.point == nodes.Aka[i].point)) {
		memcpy(res, &nodes.Aka[i], sizeof(fidoaddr));
		Syslog('+', "R: %s => Dir link %s", ascfnode(dest, 0x0f), aka2str(*res));
		tidy_faddr(best);
		tidy_faddr(dest);
		return R_DIRECT;
	    }
	}
    }

    /*
     * Again, but now for points
     */
    Syslog('r', "Checking for a direct link, 3d");
    dir.point = 0;
    if (SearchNode(dir)) {
	for (i = 0; i < 20; i++) {
	    if ((dir.zone  == nodes.Aka[i].zone) && (dir.node  == nodes.Aka[i].node) && (dir.net   == nodes.Aka[i].net)) {
		memcpy(res, &nodes.Aka[i], sizeof(fidoaddr));
		res->point = 0;
		Syslog('+', "R: %s => Boss link %s", ascfnode(dest, 0x0f), aka2str(*res));
		tidy_faddr(best);
		tidy_faddr(dest);
		return R_DIRECT;
	    }
	}
    }

    /*
     * Check if we know the uplink, but first check if the node is listed.
     */
    Syslog('r', "Checking for a known uplink");
    dnlent = (node *)malloc(sizeof(node));
    memcpy(dnlent, getnlent(dest), sizeof(node));
    if (dnlent->addr.domain)
	free(dnlent->addr.domain);

    if (!(dnlent->pflag & NL_DUMMY)) {
	dir.node = dnlent->upnode;
	dir.net  = dnlent->upnet;
	if (SearchNode(dir)) {
	    for (i = 0; i < 20; i++) {
		if ((dir.zone  == nodes.Aka[i].zone) && (dir.node  == nodes.Aka[i].node) && (dir.net   == nodes.Aka[i].net)) {
		    memcpy(res, &nodes.Aka[i], sizeof(fidoaddr));
		    res->point = 0;
		    Syslog('+', "R: %s => Uplink %s", ascfnode(dest, 0x0f), aka2str(*res));
		    free(dnlent);
		    tidy_faddr(best);
		    tidy_faddr(dest);
		    return R_DIRECT;
		}
	    }
	}
    }

    /*
     *  We don't know the route from direct links. We will first see
     *  what we are, host, hub or node.
     */
    me_host = AreWeHost(dest);
    if (me_host == -1)
	me_hub = AreWeHub(dest);
    bnlent = getnlent(best);
    myregion = bnlent->region;
    Syslog('r', "We are in region %d", myregion);

    /*
     *  This is default routing for hosts:
     *   1.  Out of zone and region mail goes to the myzone:myregion/0
     *   2.  Out of net mail goes to host myzone:destnet/0
     *   3.  Nodes without hub are my downlinks, no route.
     *   4.  The rest goes to the hubs.
     */
    if (me_host != -1) {
	Syslog('r', "We are a host");
	sprintf(res->domain, "%s", CFG.aka[me_host].domain);
	if (((myregion != dnlent->region) && (!(dnlent->pflag & NL_DUMMY))) || (CFG.aka[me_host].zone != dest->zone)) {
	    res->zone = CFG.aka[me_host].zone;
	    res->net  = myregion;
	    Syslog('+', "R: %s => Region %s", ascfnode(dest, 0x0f), aka2str(*res));
	    free(dnlent);
	    if (bnlent->addr.domain)
		free(bnlent->addr.domain);
	    tidy_faddr(best);
	    tidy_faddr(dest);
	    return R_ROUTE;
	}
	if (CFG.aka[me_host].net != dest->net) {
	    res->zone = dest->zone;
	    res->net  = dest->net;
	    Syslog('+', "R: %s => Host %s", ascfnode(dest, 0x0f), aka2str(*res));
	    free(dnlent);
	    if (bnlent->addr.domain)
		free(bnlent->addr.domain);
	    tidy_faddr(best);
	    tidy_faddr(dest);
	    return R_ROUTE;
	}
	if (dnlent->upnode == 0) {
	    res->zone  = dest->zone;
	    res->net   = dest->net;
	    res->node  = dest->node;
	    Syslog('+', "R: %s => Dir link %s", ascfnode(dest, 0x0f), aka2str(*res));
	    free(dnlent);
	    if (bnlent->addr.domain)
		free(bnlent->addr.domain);
	    tidy_faddr(best);
	    tidy_faddr(dest);
	    return R_ROUTE;
	}
	res->zone = CFG.aka[me_host].zone;
	res->net  = dnlent->upnet;
	res->node = dnlent->upnode;
	Syslog('+', "R: %s => Hub %s", ascfnode(dest, 0x0f), aka2str(*res));
	free(dnlent);
	if (bnlent->addr.domain)
	    free(bnlent->addr.domain);
	tidy_faddr(best);
	tidy_faddr(dest);
	return R_ROUTE;
    }

    /*
     *  This is the default routing for hubs.
     *   1.  If the nodes hub is our own hub, it's a downlink.
     *   2.  Kick everything else to the host.
     */
    if (me_hub != -1) {
	Syslog('r', "We are a hub");
	sprintf(res->domain, "%s", CFG.aka[me_hub].domain);
	if ((dnlent->upnode == CFG.aka[me_hub].node) && (dnlent->upnet  == CFG.aka[me_hub].net) && 
		(dnlent->addr.zone == CFG.aka[me_hub].zone)) {
	    res->zone  = dest->zone;
	    res->net   = dest->net;
	    res->node  = dest->node;
	    res->point = dest->point;
	    Syslog('+', "R: %s => Dir link %s", ascfnode(dest, 0x0f), aka2str(*res));
	    free(dnlent);
	    if (bnlent->addr.domain)
		free(bnlent->addr.domain);
	    tidy_faddr(best);
	    tidy_faddr(dest);
	    return R_DIRECT;
	} else {
	    res->zone = CFG.aka[me_hub].zone;
	    res->net  = CFG.aka[me_hub].net;
	    Syslog('+', "R: %s => My host %s", ascfnode(dest, 0xff), aka2str(*res));
	    free(dnlent);
	    if (bnlent->addr.domain)
		free(bnlent->addr.domain);
	    tidy_faddr(best);
	    tidy_faddr(dest);
	    return R_ROUTE;
	}
    }
    free(dnlent);

    /*
     *  Routing for normal nodes, everything goes to the hub or host.
     */
    if ((me_hub == -1) && (me_host == -1)) {
	Syslog('r', "We are a normal node");
	if (bnlent->pflag != NL_DUMMY) {
	    res->zone = bnlent->addr.zone;
	    res->net  = bnlent->upnet;
	    res->node = bnlent->upnode;
	    sprintf(res->domain, "%s", bnlent->addr.domain);
	    Syslog('+', "R: %s => %s", ascfnode(dest, 0xff), aka2str(*res));
	    if (bnlent->addr.domain)
		free(bnlent->addr.domain);
	    tidy_faddr(best);
	    tidy_faddr(dest);
	    return R_ROUTE;
	}

	if (bnlent->addr.domain)
	    free(bnlent->addr.domain);

	/*
	 *  If the above failed, we are probably a new node without
	 *  a nodelist entry. We will switch to plan B.
	 */
	Syslog('r', "Plan B, we are a unlisted node");
	if ((fil = fopen(nodes_fil, "r")) != NULL) {
	    fread(&nodeshdr, sizeof(nodeshdr), 1, fil);
	    nodes_pos = -1;
	    while (fread(&nodes, nodeshdr.recsize, 1, fil) == 1) {
		fseek(fil, nodeshdr.filegrp + nodeshdr.mailgrp, SEEK_CUR);
		for (i = 0; i < 20; i++) {
		    if ((nodes.Aka[i].zone) && (nodes.Aka[i].zone == best->zone) && (nodes.Aka[i].net  == best->net)) {
			maddr = fido2faddr(nodes.Aka[i]);
			bnlent = getnlent(maddr);
			tidy_faddr(maddr);
			if (bnlent->addr.domain)
			    free(bnlent->addr.domain);
			if ((bnlent->type == NL_HUB) || (bnlent->type == NL_HOST)) {
			    fclose(fil);
			    memcpy(res, &nodes.Aka[i], sizeof(fidoaddr));
			    Syslog('r', "R: %s => %s", ascfnode(dest, 0xff), aka2str(*res));
			    tidy_faddr(best);
			    tidy_faddr(dest);
			    return R_DIRECT;
			}
		    }
		}
	    }
	    fclose(fil);
	}
    }

    WriteError("Routing parse error 2");
    tidy_faddr(best);
    tidy_faddr(dest);
    return R_NOROUTE;
}



void TestTracker(faddr *dest)
{
    fidoaddr	addr, result;
    int		rc;
    char	*too;

    memset(&addr, 0, sizeof(fidoaddr));
    addr.zone  = dest->zone;
    addr.net   = dest->net;
    addr.node  = dest->node;
    addr.point = dest->point;

    mbse_colour(LIGHTGRAY, BLACK);
    Syslog('+', "Test route to %s", aka2str(addr));

    rc = TrackMail(addr, &result);
    too = xstrcpy(aka2str(addr));
    printf("Route %s => %s, route result: %s\n", too, aka2str(result), get_routetype(rc));
    free(too);
}