/*
    protocol_node.c -- handle the meta-protocol, nodes
    Copyright (C) 1999-2002 Ivo Timmermans <ivo@o2w.nl>,
                  2000-2002 Guus Sliepen <guus@sliepen.eu.org>

    This program 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 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    $Id: protocol_node.c,v 1.1.4.8 2002/09/09 21:25:02 guus Exp $
*/

#include "config.h"

#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <stdio.h>
#include <stdarg.h>
#include <errno.h>

#include <utils.h>
#include <xalloc.h>
#include <avl_tree.h>

#include "conf.h"
#include "net.h"
#include "netutl.h"
#include "protocol.h"
#include "meta.h"
#include "connection.h"
#include "node.h"

#include "system.h"

int send_add_node(connection_t * c, node_t * n)
{
	int x;
	char *address, *port;
	cp();
	if(!n->status.reachable)
		return 0;

	sockaddr2str(&n->address, &address, &port);
	x = send_request(c, "%d %s %s %s %lx %d %s %s", ADD_NODE, n->name, address, port, n->options, n->distance + 1,	// Alternatively, use n->distance + c->estimated_weight
					 n->prevhop->name, n->via->name);
	free(address);
	free(port);
	cp();
	return x;
}

int add_node_h(connection_t * c)
{
	connection_t *other;
	node_t *n, *prevhop, *via;
	char name[MAX_STRING_SIZE];
	char address[MAX_STRING_SIZE];
	char port[MAX_STRING_SIZE];
	char prevhopname[MAX_STRING_SIZE];
	char vianame[MAX_STRING_SIZE];
	long int options;
	int distance;
	avl_node_t *node;
	cp();
	if(sscanf
	   (c->buffer,
		"%*d " MAX_STRING " " MAX_STRING " " MAX_STRING " %lx %d " MAX_STRING
		" " MAX_STRING, name, address, port, &options, &distance, prevhopname,
		vianame) != 7) {
		syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ADD_NODE", c->name,
			   c->hostname);
		return -1;
	}

	/* Check if names are valid */

	if(check_id(name)) {
		syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_NODE", c->name,
			   c->hostname, _("invalid name"));
		return -1;
	}

	/* This node is indirect if it's nexthop is as well */

	if(c->node->options & OPTION_INDIRECT)
		options |= OPTION_INDIRECT;

	/* Lookup nodes */

	prevhop = lookup_node(prevhopname);

	if(!prevhop) {
		prevhop = new_node();
		prevhop->name = xstrdup(prevhopname);
		node_add(prevhop);
	}

	via = lookup_node(vianame);

	if(!via) {
		via = new_node();
		via->name = xstrdup(vianame);
		node_add(via);
	}

	n = lookup_node(name);

	if(!n) {
		// It's a new node. Add it and tell the others.
		n = new_node();
		n->name = xstrdup(name);
		n->address = str2sockaddr(address, port);
		n->hostname = sockaddr2hostname(&n->address);
		n->options = options;
		n->distance = distance;
		n->nexthop = c->node;
		n->prevhop = prevhop;
		n->via = via;
		node_add(n);
		if(prevhop == myself) {
			syslog(LOG_WARNING,
				   _
				   ("Got ADD_NODE %s prevhop %s via %s from %s, sending back a DEL_NODE!"),
				   name, prevhopname, vianame, c->name);
			// send_del_node(c, n);
			return 0;
		}
		n->status.reachable = 1;
	} else {
		// If this ADD_NODE is closer or more direct, use it instead of the old one.
		if(!n->status.reachable
		   || ((n->options & OPTION_INDIRECT) && !(options & OPTION_INDIRECT))
		   || n->distance > distance) {
			if(prevhop == myself) {
				syslog(LOG_WARNING,
					   _("Got ADD_NODE %s prevhop %s via %s from %s!"), name,
					   prevhopname, vianame, c->name);
				// send_del_node(c, n);
				return 0;
			}
			node = avl_unlink(node_udp_tree, n);
			n->address = str2sockaddr(address, port);
			avl_insert_node(node_udp_tree, node);
			if(n->hostname)
				free(n->hostname);
			n->hostname = sockaddr2hostname(&n->address);
			n->options = options;
			n->distance = distance;
			n->via = n->nexthop = c->node;
			n->status.reachable = 1;
			n->status.validkey = 0;
			n->status.waitingforkey = 0;
		} else
			// Otherwise, just ignore it.
			return 0;
	}

	/* Tell the rest about the new node */

	for(node = connection_tree->head; node; node = node->next) {
		other = (connection_t *) node->data;
		if(other->status.active && other != c)
			send_add_node(other, n);
	}

	cp();
	return 0;
}

int send_del_node(connection_t * c, node_t * n)
{
	cp();
	return send_request(c, "%d %s %s", DEL_NODE, n->name, n->prevhop->name);
}

int del_node_h(connection_t * c)
{
	char name[MAX_STRING_SIZE];
	char prevhopname[MAX_STRING_SIZE];
	node_t *n, *prevhop;
	connection_t *other;
	avl_node_t *node;
	cp();
	if(sscanf(c->buffer, "%*d " MAX_STRING " " MAX_STRING, name, prevhopname) !=
	   2) {
		syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "DEL_NODE", c->name,
			   c->hostname);
		return -1;
	}

	/* Check if names are valid */

	if(check_id(name)) {
		syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_NODE", c->name,
			   c->hostname, _("invalid name"));
		return -1;
	}

	/* Lookup nodes */

	n = lookup_node(name);
	prevhop = lookup_node(prevhopname);

	if(!n || !prevhop) {
		if(debug_lvl >= DEBUG_PROTOCOL)
			syslog(LOG_WARNING,
				   _
				   ("Got %s from %s (%s) which does not appear in the node tree"),
				   "DEL_NODE", c->name, c->hostname);
		return 0;
	}

	/* If we got a DEL_NODE but we know of a different route to it, tell the one who send the DEL_NODE */

	if(n->nexthop != c->node) {
		return send_add_node(c, n);
	}

	/* Otherwise, tell the rest about the deleted node */

	for(node = connection_tree->head; node; node = node->next) {
		other = (connection_t *) node->data;
		if(other->status.active && other != c)
			send_del_node(other, n);
	}

	/* "Delete" the node */

	n->status.reachable = 0;
	n->status.validkey = 0;
	cp();
	return 0;
}