paulo@0: /*
paulo@0:  * $Id: ping.c,v 1.4 2004/03/05 17:49:40 hipnod Exp $
paulo@0:  *
paulo@0:  * Copyright (C) 2001-2003 giFT project (gift.sourceforge.net)
paulo@0:  *
paulo@0:  * This program is free software; you can redistribute it and/or modify it
paulo@0:  * under the terms of the GNU General Public License as published by the
paulo@0:  * Free Software Foundation; either version 2, or (at your option) any
paulo@0:  * later version.
paulo@0:  *
paulo@0:  * This program is distributed in the hope that it will be useful, but
paulo@0:  * WITHOUT ANY WARRANTY; without even the implied warranty of
paulo@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
paulo@0:  * General Public License for more details.
paulo@0:  */
paulo@0: 
paulo@0: #include "gt_gnutella.h"
paulo@0: #include "message/msg_handler.h"
paulo@0: 
paulo@0: #include "gt_node_list.h"
paulo@0: #include "gt_bind.h"
paulo@0: #include "gt_netorg.h"
paulo@0: 
paulo@0: #include "gt_stats.h"
paulo@0: #include "gt_share.h"
paulo@0: 
paulo@0: /******************************************************************************/
paulo@0: 
paulo@0: BOOL gt_is_pow2 (uint32_t num)
paulo@0: {
paulo@0: 	return BOOL_EXPR (num > 0 && (num & (num-1)) == 0);
paulo@0: }
paulo@0: 
paulo@0: static uint32_t get_shared_size (unsigned long size_mb)
paulo@0: {
paulo@0: 	uint32_t size_kb;
paulo@0: 
paulo@0: 	size_kb = size_mb * 1024;
paulo@0: 
paulo@0: 	if (GT_SELF->klass & GT_NODE_ULTRA)
paulo@0: 		/* TODO: round up to nearest power of two >= 8 here */;
paulo@0: 	else if (gt_is_pow2 (size_kb))
paulo@0: 		size_kb += 5; /* unmakes all powers of two, including 1 */
paulo@0: 
paulo@0: 	return size_kb;
paulo@0: }
paulo@0: 
paulo@0: /* reply to a ping packet */
paulo@0: static void ping_reply_self (GtPacket *packet, TCPC *c)
paulo@0: {
paulo@0: 	unsigned long  files, size_kb;
paulo@0: 	double         size_mb;
paulo@0: 	GtPacket      *reply;
paulo@0: 
paulo@0: 	share_index (&files, &size_mb);
paulo@0: 	size_kb = get_shared_size (size_mb);
paulo@0: 
paulo@0: 	if (!(reply = gt_packet_reply (packet, GT_MSG_PING_REPLY)))
paulo@0: 		return;
paulo@0: 
paulo@0: 	gt_packet_put_port   (reply, GT_SELF->gt_port);
paulo@0: 	gt_packet_put_ip     (reply, GT_NODE(c)->my_ip);
paulo@0: 	gt_packet_put_uint32 (reply, (uint32_t)files);
paulo@0: 	gt_packet_put_uint32 (reply, (uint32_t)size_kb);
paulo@0: 
paulo@0: 	if (gt_packet_error (reply))
paulo@0: 	{
paulo@0: 		gt_packet_free (reply);
paulo@0: 		return;
paulo@0: 	}
paulo@0: 
paulo@0: 	gt_packet_send (c, reply);
paulo@0: 	gt_packet_free (reply);
paulo@0: }
paulo@0: 
paulo@0: /* send info about node dst to node c */
paulo@0: static TCPC *send_status (TCPC *c, GtNode *node, void **data)
paulo@0: {
paulo@0: 	GtPacket   *pkt = (GtPacket *)   data[0];
paulo@0: 	TCPC       *dst = (TCPC *)       data[1];
paulo@0: 	GtPacket   *reply;
paulo@0: 
paulo@0: 	/* don't send a ping for the node itself */
paulo@0: 	if (c == dst)
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	if (!(reply = gt_packet_reply (pkt, GT_MSG_PING_REPLY)))
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	gt_packet_put_port   (reply, node->gt_port);
paulo@0: 	gt_packet_put_ip     (reply, node->ip);
paulo@0: 	gt_packet_put_uint32 (reply, node->files);
paulo@0: 	gt_packet_put_uint32 (reply, node->size_kb);
paulo@0: 
paulo@0: 	/* set the number of hops travelled to 1 */
paulo@0: 	gt_packet_set_hops (reply, 1);
paulo@0: 
paulo@0: 	if (gt_packet_error (reply))
paulo@0: 	{
paulo@0: 		gt_packet_free (reply);
paulo@0: 		return NULL;
paulo@0: 	}
paulo@0: 
paulo@0: 	gt_packet_send (dst, reply);
paulo@0: 	gt_packet_free (reply);
paulo@0: 
paulo@0: 	return NULL;
paulo@0: }
paulo@0: 
paulo@0: static void handle_crawler_ping (GtPacket *packet, TCPC *c)
paulo@0: {
paulo@0: 	void *data[2];
paulo@0: 
paulo@0: 	data[0] = packet;
paulo@0: 	data[1] = c;
paulo@0: 
paulo@0: 	/* reply ourselves */
paulo@0: 	ping_reply_self (packet, c);
paulo@0: 
paulo@0: 	/* send pings from connected hosts */
paulo@0: 	gt_conn_foreach (GT_CONN_FOREACH(send_status), data,
paulo@0: 	                 GT_NODE_NONE, GT_NODE_CONNECTED, 0);
paulo@0: }
paulo@0: 
paulo@0: static BOOL need_connections (void)
paulo@0: {
paulo@0: 	BOOL am_ultrapeer;
paulo@0: 
paulo@0: 	am_ultrapeer = GT_SELF->klass & GT_NODE_ULTRA;
paulo@0: 
paulo@0: 	/* send a pong if we need connections, but do this
paulo@0: 	 * only if this is a search node: leaves shouldnt send pongs */
paulo@0: 	if (gt_conn_need_connections (GT_NODE_ULTRA) > 0 && am_ultrapeer)
paulo@0: 		return TRUE;
paulo@0: 
paulo@0: 	/* pretend we need connections temporarily even if we don't in order to
paulo@0: 	 * figure out whether we are firewalled or not */
paulo@0: 	if (gt_uptime () < 10 * EMINUTES && GT_SELF->firewalled)
paulo@0: 		return TRUE;
paulo@0: 
paulo@0: 	return FALSE;
paulo@0: }
paulo@0: 
paulo@0: GT_MSG_HANDLER(gt_msg_ping)
paulo@0: {
paulo@0: 	time_t   last_ping_time, now;
paulo@0: 	uint8_t  ttl, hops;
paulo@0: 
paulo@0: 	now = time (NULL);
paulo@0: 
paulo@0: 	ttl  = gt_packet_ttl (packet);
paulo@0: 	hops = gt_packet_hops (packet);
paulo@0: 
paulo@0: 	last_ping_time = GT_NODE(c)->last_ping_time;
paulo@0: 	GT_NODE(c)->last_ping_time = now;
paulo@0: 
paulo@0: 	if ((ttl == 1 && (hops == 0 || hops == 1))    /* tests if host is up */
paulo@0: 	 || GT_NODE(c)->state == GT_NODE_CONNECTING_2 /* need to reply */
paulo@0: 	 || need_connections ())                      /* we need connections */
paulo@0: 	{
paulo@0: 		ping_reply_self (packet, c);
paulo@0: 
paulo@0: 		if (ttl == 1)
paulo@0: 			return;
paulo@0: 	}
paulo@0: 	else if (ttl == 2 && hops == 0)
paulo@0: 	{
paulo@0: 		/* crawler ping: respond with all connected nodes */
paulo@0: 		handle_crawler_ping (packet, c);
paulo@0: 		return;
paulo@0: 	}
paulo@0: 
paulo@0: 	/* dont re-broadcast pings from search nodes if we are not one */
paulo@0: 	if ((GT_NODE(c)->klass & GT_NODE_ULTRA) && !(GT_SELF->klass & GT_NODE_ULTRA))
paulo@0: 	   return;
paulo@0: 
paulo@0: #if 0
paulo@0: 	/* notify this host when the pong cache gets full */
paulo@0: 	pong_cache_waiter_add (c, packet);
paulo@0: #endif
paulo@0: 
paulo@0: 	/* dont accept pings too often */
paulo@0: 	if (now - last_ping_time < 30 * ESECONDS)
paulo@0: 		return;
paulo@0: 
paulo@0: #if 0
paulo@0: 	if (!pong_cache_reply (c, packet))
paulo@0: 	{
paulo@0: 		/* refill the pong cache */
paulo@0: 		pong_cache_refill ();
paulo@0: 		return;
paulo@0: 	}
paulo@0: 
paulo@0: 	pong_cache_waiter_remove (c);
paulo@0: #endif
paulo@0: }