RIOT/sys/net/mm/mmr.c

/******************************************************************************
Copyright 2009, Freie Universitaet Berlin (FUB). All rights reserved.

These sources were developed at the Freie Universitaet Berlin, Computer Systems
and Telematics group (http://cst.mi.fu-berlin.de).
-------------------------------------------------------------------------------
This file is part of RIOT.

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

RIOT 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, see http://www.gnu.org/licenses/ .
--------------------------------------------------------------------------------
For further information and questions please use the web site
	http://scatterweb.mi.fu-berlin.de
and the mailinglist (subscription via web site)
	scatterweb@lists.spline.inf.fu-berlin.de
*******************************************************************************/

/**
 * @file
 * @internal
 * @brief		Micro Mesh Routing
 *
 * @author      Freie Universität Berlin, Computer Systems & Telematics
 * @author		Thomas Hillebrandt <hillebra@inf.fu-berlin.de>
 * @version     $Revision: 3854 $
 *
 * @note		$Id: mmr.c 3854 2011-12-06 15:27:01Z hwill $
 */

#include "configure.h"
#include "mmr.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "net.h"

#include "clock.h"
#include "utimer.h"
#include "kernel.h"
#include "thread.h"
#include "msg.h"

#define LEVEL_INFO	2				///< All messages are printed
#define LEVEL_WARN	1				///< Only warnings and error messages are printed
#define LEVEL_ERROR	0				///< Only error messages are printed
#define MMR_INFO_LEVEL LEVEL_WARN	///< Current information level

#define DEBUG(...)
//#define DEBUG(...) printf(__VA_ARGS__)

#define CONSTANT_SECOND					 (1)

#define RREQ_ID_SEQUENCE_NUMBER_START	 (1)
#define RREQ_THRESHOLD					 (3)
#define RREQ_NONE						 (0xFF)	// Send no RREQs for these messages, value
                                                // must be greater than RREQ_THRESHOLD

#define TTL_START						 (1)
#define TTL_THRESHOLD					(10)

#define RREQ_TIMEOUT_BASE		(2*CONSTANT_SECOND)
#define RREQ_TIMEOUT_PER_TTL	(1*CONSTANT_SECOND)

/*---------------------------------------------------------------------------*/
//					Message queue data structures
/*---------------------------------------------------------------------------*/

#define MESSAGE_QUEUE_SIZE	(20)

typedef struct message_queue_entry_t
{
	net_message_t message;
	volatile uint32_t timestamp;
	uint8_t retry_count;
} message_queue_entry_t;

static message_queue_entry_t message_queue[MESSAGE_QUEUE_SIZE];

/*---------------------------------------------------------------------------*/
//					RREQ-Timeout data structures
/*---------------------------------------------------------------------------*/

static struct utimer ut;
static volatile bool rreq_to_active = false;		// RREQ timeout active bit
static const char *rreq_timeout_process_name  = "mmrd";
static uint16_t rreq_timeout_process_pid;
static void rreq_timeout_process(void);
static void post_next_rreq_timeout(void);

/*---------------------------------------------------------------------------*/
//					Statistic data structures
/*---------------------------------------------------------------------------*/

typedef struct mmr_stat
{
	uint32_t rreq_originated;
	uint32_t rrep_originated;
	uint32_t rerr_originated;
	uint32_t rreq_received;
	uint32_t rrep_received;
	uint32_t rerr_received;
	uint32_t messages_no_route_found;				// RREQ found no route
	uint32_t messages_no_route_avail_on_forward;	// Forwarding: no route in route table
	uint32_t messages_broken_link_on_forward;		// Forwarding: broken link detected
	uint32_t rreq_duplicated;
} mmr_stat_t;

static mmr_stat_t mmr_stats;

/*---------------------------------------------------------------------------*/

/**
 * Returns time of RTC in seconds.
 *
 * @return Time of RTC in seconds
 */
static uint32_t rtc_now(void)
{
	return (uint32_t)(clock_get_systemtime()/1000);
}

/*---------------------------------------------------------------------------*/
//					Routing table management
/*---------------------------------------------------------------------------*/

/**
 * @brief	Extract route information and store them in route table.
 *
 * @param 	local_addr Local network address of this node
 * @param 	length Length of address list
 * @param 	list Address list with route information
 */
static void rt_extract_routes(uint16_t local_addr, uint8_t length, uint16_t* list)
{
	DEBUG("call [%u]: rt_extract_routes\n", fk_thread->pid);
	uint16_t net_id = NETWORK_ADDR_BC(list[0]); 		// BC address of source of RREQ
	route_table_entry_t* rte = rt_lookup_route(net_id);	// Should exist (preconfigured)
	if (rte == NULL) {
		DEBUG("exit [%u]: rt_extract_routes\n", fk_thread->pid);
		return;											// else exit here
	}

	int i = 0;
	while (i < length && list[i] != local_addr) i++;
	if (i == length) {
		DEBUG("exit [%u]: rt_extract_routes\n", fk_thread->pid);
		return;
	}

	int pos = i;
	int leftNeighbour = -1;
	int rightNeighbour = -1;
	if (pos > 0)
	{
		leftNeighbour = list[pos-1];
	}
	if (pos+1 != length)
	{
		rightNeighbour = list[pos+1];
	}

	i = 0;
	while (i < length)
	{
		uint16_t next = list[i];
		if (local_addr != next)
		{
			int distance = pos - i;
			int router = leftNeighbour;
			if (distance < 0) { router = rightNeighbour; distance *= -1; }
			rt_add_route(next, (uint16_t)router, (uint8_t)distance, rte->interface_id);
		}
		i++;
	}
	DEBUG("exit [%u]: rt_extract_routes\n", fk_thread->pid);
}

/*---------------------------------------------------------------------------*/
//					Message queue management
/*---------------------------------------------------------------------------*/

/**
 * @brief	Add a message to the message queue.
 *
 * @param 	msg The packet to add to the queue
 *
 * @return	A pointer to a message queue entry or NULL if
 *          message queue is full.
 */
static message_queue_entry_t* mq_add(net_message_t* msg)
{
	DEBUG("call [%u]: mq_add\n", fk_thread->pid);

	// Holds eventually first active RREQ to same destination
	message_queue_entry_t* pFirstFoundDup = NULL;

	// Find the first active RREQ to this destination
	int i;
	for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
	{
		if (message_queue[i].timestamp != 0 && message_queue[i].message.destination == msg->destination &&
				message_queue[i].retry_count != RREQ_NONE)
		{
			DEBUG("%s FOUND Duplicated Request to %u.%u in route req queue\n",__FUNCTION__,(0xFF00&msg->destination)>>8,(0xFF&msg->destination));

			// Save the first found entry to modify later if insertion was successful
			pFirstFoundDup = &message_queue[i];
			break;
		}
	}

	// If RREQ for same destination found then reset values
	// even if the new message will get dropped later on because of
	// limited queue space. Route to this destination gets queried
	// again for sure so make new RREQ as soon as possible...
	if (pFirstFoundDup != NULL) {
		pFirstFoundDup->retry_count = 0;
		pFirstFoundDup->timestamp = 1;
		mmr_stats.rreq_duplicated++;
	}

	// Find free position to insert new message
	for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
	{
		if (message_queue[i].timestamp == 0)
		{
			// Free position found, add entry
			message_queue[i].message = *msg;
			if (pFirstFoundDup != NULL) {
				// There is already a RREQ for this destination, so don't generate a new one
				message_queue[i].retry_count = RREQ_NONE;
			} else {
				// Set initial RREQ retry counter to zero
				message_queue[i].retry_count = 0;
			}
			message_queue[i].timestamp = 1;
			DEBUG("exit [%u]: mq_add\n", fk_thread->pid);
			return &message_queue[i];
		}
	}

	DEBUG("exit [%u]: mq_add\n", fk_thread->pid);
	return NULL;
}

/**
 * @brief	Count messages for given destination.
 *
 * @param 	dst Destination address
 *
 * @return	The number of messages for the destination.
 */
static int mq_msgs_for_destination(uint16_t dst)
{
	DEBUG("call [%u]: mq_msgs_for_destination\n", fk_thread->pid);
	int i, dst_count = 0;
	for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
	{
		if (message_queue[i].timestamp != 0 && message_queue[i].message.destination == dst)
		{
			dst_count++;
		}
	}
	DEBUG("exit [%u]: mq_msgs_for_destination\n", fk_thread->pid);
	return dst_count;
}

/**
 * @brief	Remove all messages for given destination out of message queue.
 *
 * @param 	dst Destination address
 */
static void mq_remove_msgs_for_destination(uint16_t dst)
{
	DEBUG("call [%u]: mq_remove_msgs_for_destination\n", fk_thread->pid);
	int i;
	for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
	{
		if (message_queue[i].timestamp != 0 && message_queue[i].message.destination == dst)
		{
			message_queue[i].timestamp = 0;
		}
	}
	DEBUG("exit [%u]: mq_remove_msgs_for_destination\n", fk_thread->pid);
}

/**
 * @brief	Send all queued messages for given destination.
 *
 * @param 	dst Destination address
 */
static void mq_dequeue_and_send(uint16_t dst)
{
	int i;
	DEBUG("call [%u]: mq_dequeue_and_send\n", fk_thread->pid);

	// Stop any pending RREQ-Timeout, it's possibly handled now
	rreq_to_active = false;
	utimer_remove(&ut);

	// Prioritize packets for given destination, route entry should exist
	route_table_entry_t* rte = rt_lookup_route(dst);
	if (rte != NULL)
	{
		for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
		{
			if (message_queue[i].timestamp != 0 && message_queue[i].message.destination == dst)
			{
				bool res = net_enqueue_for_transmission(&message_queue[i].message, rte->interface_id, rte->gateway, true);
				if (res) message_queue[i].timestamp = 0;
			}
		}
	}
	// Now all other packets
	for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
	{
		if (message_queue[i].timestamp != 0 && message_queue[i].message.destination != dst)
		{
			route_table_entry_t* rte = rt_lookup_route(message_queue[i].message.destination);
			if (rte != NULL)
			{
				bool res = net_enqueue_for_transmission(&message_queue[i].message, rte->interface_id, rte->gateway, true);
				if (res) message_queue[i].timestamp = 0;
			}
		}
	}

	// This function was triggered either by RREP packet or RREQ-Timeout.
	// So update or set new RREQ-Timeout for other packets in queue.
	post_next_rreq_timeout();
	DEBUG("exit [%u]: mq_dequeue_and_send\n", fk_thread->pid);
}

/*---------------------------------------------------------------------------*/
//					Initialization of MMR layer
/*---------------------------------------------------------------------------*/

void mmr_init(void)
{
	rt_init();
	memset(message_queue, 0, sizeof(message_queue_entry_t) * MESSAGE_QUEUE_SIZE);
	rreq_timeout_process_pid = thread_create(2500, PRIORITY_MMREQ, CREATE_STACKTEST,
			rreq_timeout_process, rreq_timeout_process_name);
}

/*---------------------------------------------------------------------------*/
//						Send & receive functions
/*---------------------------------------------------------------------------*/

/**
 * @brief	Tests if the net message contains a RERR.
 *
 * @param 	msg The net message to test
 *
 * @return	true if the net message contains a RERR; false otherwise.
 */
static bool is_route_error(net_message_t* msg)
{
	if (msg->protocol == LAYER_2_PROTOCOL_MMR)
	{
		// First byte in {RREQ, RREP, RERR} is always type
		if (msg->payload[0] == MMR_TYPE_RERR) return true;
	}
	return false;
}

/**
 * @brief	Generates a route reply message.
 *
 * @param 	rreq_msg Corresponding route request message
 */
static void generate_route_reply_message(mmr_rreq_message_t* rreq_msg)
{
	DEBUG("call [%u]: generate_route_reply_message\n", fk_thread->pid);
	// Create RREP message
	mmr_rrep_message_t rrep_msg;
	rrep_msg.type = MMR_TYPE_RREP;
	rrep_msg.length = rreq_msg->length;
	rrep_msg.destination = rreq_msg->source;
	rrep_msg.source = rreq_msg->destination;
	memcpy(rrep_msg.address, rreq_msg->address, rreq_msg->length * sizeof(uint16_t));

	// Create MMR message containing the RREP message
	net_message_t net_msg;
	net_msg.protocol = LAYER_2_PROTOCOL_MMR;
	net_msg.flags_tos = PRIORITY_ALARM;
	net_msg.seq_clr_id = 0;
	net_msg.ttl = TTL_THRESHOLD;
	net_msg.source = rrep_msg.source;
	net_msg.destination = rrep_msg.destination;
	memcpy(net_msg.payload, (void*)&rrep_msg, sizeof(mmr_rrep_message_t));

	// Source address must exist in route table to find correct
	// interface id and next hop (should be created by RREQ)
	route_table_entry_t* rte = rt_lookup_route(net_msg.destination);
	if (rte != NULL)
	{
		// Send message to next hop
		mmr_stats.rrep_originated++;
		net_enqueue_for_transmission(&net_msg, rte->interface_id, rte->gateway, true);
	}
	DEBUG("exit [%u]: generate_route_reply_message\n", fk_thread->pid);
}

/**
 * @brief	Generates a route error message.
 *
 * @param 	dst Destination address of RERR packet
 * @param 	gateway Next hop network address of RERR packet
 * @param 	intf Interface id of RERR packet
 * @param 	type Error type of RERR packet
 * @param 	type_data Type specific data of RERR packet
 */
static void generate_route_error_message(uint16_t dst, uint16_t gateway, int intf, uint8_t type, uint16_t type_data)
{
	DEBUG("call [%u]: generate_route_error_message\n", fk_thread->pid);
	// Define RERR message
	mmr_rerr_message_t rerr_msg;
	rerr_msg.type = MMR_TYPE_RERR;
	rerr_msg.error_type = type;
	rerr_msg.type_specific_info = type_data;

	// Wrap RERR message in net message
	net_message_t net_msg;
	net_msg.protocol = LAYER_2_PROTOCOL_MMR;
	net_msg.flags_tos = PRIORITY_DATA;
	net_msg.seq_clr_id = 0;
	net_msg.ttl = TTL_THRESHOLD;
	net_msg.source = net_get_address_in_subnet(dst);
	net_msg.destination = dst;
	memcpy(net_msg.payload, (void*)&rerr_msg, sizeof(mmr_rerr_message_t));

	// Send message to next hop
	mmr_stats.rerr_originated++;
	net_enqueue_for_transmission(&net_msg, intf, gateway, true);
	DEBUG("exit [%u]: generate_route_error_message\n", fk_thread->pid);
}

/**
 * @brief	Receive a route request message.
 *
 * @param 	msg The route request packet
 * @param 	packet_info Additional packet information
 */
static void receive_route_request_message(mmr_rreq_message_t* msg, packet_info_t* packet_info)
{
	DEBUG("call [%u]: receive_route_request_message\n", fk_thread->pid);
	uint16_t my_addr = net_get_address_in_subnet(msg->source);
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
	if (my_addr == 0)
	{
		puts("MMR [WARN]: received RREQ with unknown network part of source address");
		puts("MMR [WARN]: => can't find own net address in sub net!");
	}
#endif
	// If address list of RREQ message has enough space
	if (msg->length < ADDRESS_LIST_SIZE)
	{
		// append our node id to list
		msg->address[msg->length++] = my_addr;
		// add routes with overhearing
		rt_extract_routes(my_addr, msg->length, msg->address);
	}
	// Distance between sender and receiver is too long, discard packet
	else
	{
		// Drop RREQ packet => set TTL to zero
		*packet_info->ttl_ptr = 0;
		DEBUG("exit [%u]: receive_route_request_message\n", fk_thread->pid);
		return;
	}

	// If RREQ message was send to us, then send RREP message
	if (msg->destination == my_addr)
	{
		// Don't forward RREQ packet any further => set TTL to zero
		*packet_info->ttl_ptr = 0;
		generate_route_reply_message(msg);
	}
	DEBUG("exit [%u]: receive_route_request_message\n", fk_thread->pid);
}

/**
 * @brief	Receive a route reply message.
 *
 * @param 	msg The route reply packet
 * @param 	packet_info Additional packet information
 */
static void receive_route_reply_message(mmr_rrep_message_t* msg, packet_info_t* packet_info)
{
	DEBUG("call [%u]: receive_route_reply_message\n", fk_thread->pid);
	// RREP received: Send out queued packets for which routes are now known
	mq_dequeue_and_send(msg->source);
	DEBUG("exit [%u]: receive_route_reply_message\n", fk_thread->pid);
}

/**
 * @brief	Receive a route error message.
 *
 * @param 	msg The route error packet
 * @param 	packet_info Additional packet information
 */
static void receive_route_error_message(mmr_rerr_message_t* msg, packet_info_t* packet_info)
{
	DEBUG("call [%u]: receive_route_error_message\n", fk_thread->pid);
	switch (msg->error_type)
	{
		case RERR_NODE_UNREACHABLE:
			rt_remove_route(msg->type_specific_info);
			break;
		default:
#if (MMR_INFO_LEVEL >= LEVEL_INFO)
			puts("MMR [INFO]: RERR error type is unknown");
#endif
			break;
	}
	DEBUG("exit [%u]: receive_route_error_message\n", fk_thread->pid);
}

/**
 * @brief	Computes the RREQ timeout period, given a
 *          TTL and destination address value.
 *
 * @param 	ttl Time to live
 * @param 	dst Network destination address
 *
 * @return	RREQ timeout period in seconds
 */
static int compute_rreq_timeout(int ttl, uint16_t dst)
{
	int t_hop = net_get_interface_transmission_duration(dst);
	if (t_hop == -1) {
		t_hop = RREQ_TIMEOUT_PER_TTL * ttl;
	} else {
		t_hop = (t_hop * ttl + 999) / 1000;
	}
	return RREQ_TIMEOUT_BASE + 2 * t_hop;
}

/**
 * @brief	Broadcast a RREQ message.
 *
 * A single route request can repeatedly broadcast RREQ messages,
 * with increasing TTL value, until a route has been found.
 *
 * @param 	mq_entry Pointer to a message queue entry (the packet
 *                   for which to find the route)
 */
static void rreq_broadcast(message_queue_entry_t* mq_entry)
{
	DEBUG("call [%u]: rreq_broadcast\n", fk_thread->pid);
	if(mq_entry->retry_count == RREQ_NONE)
	{
		DEBUG("call [%u]: rreq duplicated do not send\n", fk_thread->pid);
		return;
	}
	// Create RREQ message
	mmr_rreq_message_t rreq_msg;
	rreq_msg.type = MMR_TYPE_RREQ;
	rreq_msg.length = 1;
	rreq_msg.destination = mq_entry->message.destination;
	rreq_msg.source = mq_entry->message.source;
	rreq_msg.address[0] = mq_entry->message.source;

	// Wrap RREQ message in net message
	net_message_t net_msg;
	net_msg.protocol = LAYER_2_PROTOCOL_MMR;
	net_msg.flags_tos = PRIORITY_DATA;
	net_msg.seq_clr_id = 0;
	net_msg.ttl = mq_entry->retry_count == 0 ? TTL_START : TTL_THRESHOLD;
	net_msg.source = rreq_msg.source;
	net_msg.destination = NETWORK_ADDR_BC(rreq_msg.destination);
	memcpy(net_msg.payload, (void*)&rreq_msg, sizeof(mmr_rreq_message_t));

	// Broadcast the net message
	mq_entry->retry_count++;
	mq_entry->timestamp = rtc_now();
	// Find the broadcast route table entry
	route_table_entry_t* rte = rt_lookup_route(net_msg.destination);
	if (rte != NULL)
	{
		// Next hop address is broadcast address of lower layer
		net_enqueue_for_transmission(&net_msg, rte->interface_id, rte->gateway, true);
	}
	DEBUG("exit [%u]: rreq_broadcast\n", fk_thread->pid);
}

/**
 * @brief	Find next RREQ to time out. Post event immediately or
 *          with utimer.
 */
static void post_next_rreq_timeout(void)
{
	DEBUG("call [%u]: post_next_rreq_timeout\n", fk_thread->pid);
	int i, j = -1;
	uint32_t now, next = 0xffffffff;
	for (i = 0; i < MESSAGE_QUEUE_SIZE; i++)
	{
		if (message_queue[i].timestamp != 0 && message_queue[i].retry_count != RREQ_NONE)
		{
			int ttl = message_queue[i].retry_count == 1 ? TTL_START : TTL_THRESHOLD;
			int to = compute_rreq_timeout(ttl, message_queue[i].message.destination);
			if (message_queue[i].timestamp + to < next)
			{
				next = message_queue[i].timestamp + to;
				j = i;
			}
		}
	}
	if (j == -1) {
		DEBUG("exit [%u]: post_next_rreq_timeout\n", fk_thread->pid);
		return;
	}
	// Stop any utimer
	rreq_to_active = false;
	utimer_remove(&ut);
	// If current time greater than RREQ timeout value
	now = rtc_now();
	if (now >= next)
	{
		// Schedule RREQ-Timeout immediately
		msg m;
		m.type = MSG_TIMER;
		m.content.ptr = (char*)&message_queue[j];
		rreq_to_active = true;
		if (msg_send(&m, rreq_timeout_process_pid, false) != 1) {
			// Message could not be send (receiver not waiting), schedule timer with minimum delay
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
			puts("MMR [WARN]: Immediate schedule of RREQ-Timeout failed, process not waiting!");
#endif
			utimer_set_wpid(&ut, 1, rreq_timeout_process_pid, &message_queue[j]);
		}
	}
	else
	{
		// Set new utimer with time difference
		rreq_to_active = true;
		utimer_set_wpid(&ut, next - now, rreq_timeout_process_pid, &message_queue[j]);
	}
	DEBUG("exit [%u]: post_next_rreq_timeout\n", fk_thread->pid);
}

/**
 * This event is called periodically after a route request is originated,
 * until a route has been found.
 *
 * Each time it is called, it rebroadcasts the route request message with a
 * new rreq id and incremented TTL.
 */
static void rreq_timeout(message_queue_entry_t* mqe)
{
	DEBUG("call [%u]: rreq_timeout\n", fk_thread->pid);
	// Test if valid entry passed
	if (mqe->timestamp == 0)
	{
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
		puts("MMR [WARN]: invalid message queue entry for RREQ-Timeout");
#endif
		goto post_next_to;
	}
	// See if route to destination was found
	route_table_entry_t* rte = rt_lookup_route(mqe->message.destination);
	// If found and no messages in queue for destination: return (queued
	// packets are send on reception of RREP); If found but messages in
	// queue: trigger send immediately here!
	if (rte != NULL)
	{
		int msg_count = mq_msgs_for_destination(mqe->message.destination);
		if (msg_count > 0)
		{
			mq_dequeue_and_send(mqe->message.destination);
			DEBUG("exit [%u]: rreq_timeout\n", fk_thread->pid);
			return;
		}
		else
		{
			// Added just for security but this case should never occur
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
			puts("MMR [WARN]: RREQ-Timeout occurred, route is available but no messages for destination");
#endif
			// Anyway: jump to update next RREQ-Timeout
			goto post_next_to;
		}
	}
	// Otherwise send new RREQ if below threshold (means also retry count != RREQ_NONE)
	if (mqe->retry_count < RREQ_THRESHOLD)
	{
		// Broadcast new RREQ message (with incremented TTL)
		rreq_broadcast(mqe);
	}
	else
	{
		// Remove all messages for this destination
		mmr_stats.messages_no_route_found++;
		mq_remove_msgs_for_destination(mqe->message.destination);
	}
	// Anyway: update or set next RREQ-Timeout
	post_next_to:
	post_next_rreq_timeout();
	DEBUG("exit [%u]: rreq_timeout\n", fk_thread->pid);
}

static void rreq_timeout_process(void)
{
	msg m;
	do
	{
		msg_receive(&m);
		if (m.type == MSG_TIMER && rreq_to_active)
		{
			rreq_to_active = false;
			rreq_timeout((message_queue_entry_t*)m.content.ptr);
		}
	} while (m.type != MSG_EXIT);
}

void mmr_peek(net_message_t* message, packet_info_t* packet_info)
{
	DEBUG("call [%u]: mmr_peek\n", fk_thread->pid);
	// Only look at micro mesh routing messages
	if (message->protocol == LAYER_2_PROTOCOL_MMR)
	{
		uint8_t type = message->payload[0];
		uint16_t my_addr = net_get_address_in_subnet(message->source);
		if (type == MMR_TYPE_RREP)
		{
			// Add routes to route table
			mmr_rrep_message_t* rrep_msg = (mmr_rrep_message_t*)message->payload;
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
			if (my_addr == 0)
			{
				puts("MMR [WARN]: received RREP with unknown network part of source address");
				puts("MMR [WARN]: => can't find own net address in sub net!");
			}
#endif
			rt_extract_routes(my_addr, rrep_msg->length, rrep_msg->address);
		}
		else if (type == MMR_TYPE_RERR)
		{
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
			if (my_addr == 0)
			{
				puts("MMR [WARN]: received RERR with unknown network part of source address");
				puts("MMR [WARN]: => can't find own net address in sub net!");
			}
#endif
			// If not destination of RERR, then remove route to unavailable node in RERR packet
			if (message->destination != my_addr)
			{
				mmr_rerr_message_t* rerr_msg = (mmr_rerr_message_t*)message->payload;
				if (rerr_msg->error_type == RERR_NODE_UNREACHABLE)
				{
					rt_remove_route(rerr_msg->type_specific_info);
				}
			}
		}
	}
	DEBUG("exit [%u]: mmr_peek\n", fk_thread->pid);
}

bool mmr_send(net_message_t* message)
{
	DEBUG("call [%u]: mmr_send\n", fk_thread->pid);
	bool enqueue = true;
	if (message->destination == net_get_address_in_subnet(message->destination))
	{
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
		puts("MMR [WARN]: message is already at destination, why is routing called?");
#endif
		DEBUG("exit [%u]: mmr_send\n", fk_thread->pid);
		return false;
	}
	if (NETWORK_ADDR_NET(message->destination) == 0)
	{
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
		puts("MMR [WARN]: NET part of address cannot be 0!");
#endif
		DEBUG("exit [%u]: mmr_send\n", fk_thread->pid);
		return false;
	}
	if (NETWORK_ADDR_HOST(message->destination) == 0)
	{
#if (MMR_INFO_LEVEL >= LEVEL_INFO)
		puts("MMR [INFO]: broadcast destination, why is routing called? A route entry should exist!");
#endif
		enqueue = false;
	}

	// Look up next hop address for this destination in routing table
	route_table_entry_t* rte = rt_lookup_route(message->destination);

	// If next hop address found in routing table, forward message
	if (rte != NULL)
	{
		DEBUG("exit [%u]: mmr_send\n", fk_thread->pid);
		return net_enqueue_for_transmission(message, rte->interface_id, rte->gateway, true);
	}
	// Otherwise, save message in queue; broadcast RREQ message
	else
	{
		if (!enqueue) { DEBUG("exit [%u]: mmr_send\n", fk_thread->pid); return false; } // Don't enqueue broadcast destinations
		message_queue_entry_t* mqe = mq_add(message);
		if (mqe != NULL)
		{
			rreq_broadcast(mqe);
			post_next_rreq_timeout();
			mmr_stats.rreq_originated++;
			DEBUG("exit [%u]: mmr_send\n", fk_thread->pid);
			return true;
		}
	}
	DEBUG("exit [%u]: mmr_send\n", fk_thread->pid);
	return false;
}

void mmr_packet_dropped(net_message_t* message, uint16_t next_hop, int error)
{
	DEBUG("call [%u]: mmr_packet_dropped\n", fk_thread->pid);
	if (error == ROUTE_ERROR_BROKEN_ROUTE)
	{
		// Local failure detected - remove all routes through broken link
		rt_remove_gateway_routes(next_hop);
		mmr_stats.messages_broken_link_on_forward++;
	}
	else if (error == ROUTE_ERROR_MISSING_ROUTE)
	{
		mmr_stats.messages_no_route_avail_on_forward++;
	}

	// If source != net_addr, send RERR to source of message
	if (message->source != net_get_address_in_subnet(message->source))
	{
		// Do not generate RERR if it is already a RERR message
		if (is_route_error(message)) { DEBUG("exit [%u]: mmr_packet_dropped\n", fk_thread->pid); return; }
		// Find next hop to source
		route_table_entry_t* rte = rt_lookup_route(message->source);
		if (rte != NULL)
		{
			generate_route_error_message(message->source, rte->gateway,
					rte->interface_id, RERR_NODE_UNREACHABLE, message->destination);
		}
#if (MMR_INFO_LEVEL >= LEVEL_WARN)
		else
		{
			printf("MMR [WARN]: cannot send RERR to source #%u, no route found!\n", message->source);
		}
#endif
	}
	DEBUG("exit [%u]: mmr_packet_dropped\n", fk_thread->pid);
}

void mmr_receive(void* msg, int msg_size, packet_info_t* packet_info)
{
	DEBUG("call [%u]: mmr_receive\n", fk_thread->pid);
	uint8_t* p = (uint8_t*) msg;
	uint8_t type = p[0];
	if (type == MMR_TYPE_RREQ)
	{
		receive_route_request_message((mmr_rreq_message_t*)msg, packet_info);
		mmr_stats.rreq_received++;
	}
	else if (type == MMR_TYPE_RREP)
	{
		receive_route_reply_message((mmr_rrep_message_t*)msg, packet_info);
		mmr_stats.rrep_received++;
	}
	else if (type == MMR_TYPE_RERR)
	{
		receive_route_error_message((mmr_rerr_message_t*)msg, packet_info);
		mmr_stats.rerr_received++;
	}
#if (MMR_INFO_LEVEL >= LEVEL_INFO)
	else
	{
		printf("MMR [INFO]: can't handle message of type %u\n", type);
	}
#endif
	DEBUG("exit [%u]: mmr_receive\n", fk_thread->pid);
}

void mmr_print_stats(void)
{
	printf("ROUTING LAYER STATS\r\n");
	printf("-------------------\r\n");
	printf("Route requests originated: %lu\r\n", mmr_stats.rreq_originated);
	printf("Route requests duplicated: %lu\r\n", mmr_stats.rreq_duplicated);
	printf("Route replies originated:  %lu\r\n", mmr_stats.rrep_originated);
	printf("Route errors originated:   %lu\r\n", mmr_stats.rerr_originated);
	printf("Route requests received:   %lu\r\n", mmr_stats.rreq_received);
	printf("Route replies received:    %lu\r\n", mmr_stats.rrep_received);
	printf("Route errors received:     %lu\r\n", mmr_stats.rerr_received);
	printf("\r\n");
	printf("#Messages with no route found:                %lu\r\n", mmr_stats.messages_no_route_found);
	printf("#Messages with broken link on forward:        %lu\r\n", mmr_stats.messages_broken_link_on_forward);
	printf("#Messages with no route available on forward: %lu\r\n", mmr_stats.messages_no_route_avail_on_forward);
	printf("\r\n");
}