/*
 * Copyright (c) 2009 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup arp
 *  @{
 */

/** @file
 *  ARP module implementation.
 *  @see arp.h
 */

#include <async.h>
#include <malloc.h>
#include <mem.h>
#include <fibril_synch.h>
#include <stdio.h>
#include <str.h>
#include <task.h>
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <byteorder.h>
#include <err.h>

#include <net_messages.h>
#include <net/modules.h>
#include <net_device.h>
#include <arp_interface.h>
#include <nil_interface.h>
#include <protocol_map.h>
#include <adt/measured_strings.h>
#include <packet/packet.h>
#include <packet_client.h>
#include <packet_remote.h>
#include <il_messages.h>
#include <il_interface.h>
#include <il_local.h>
#include <arp_messages.h>

#include "arp.h"
#include "arp_header.h"
#include "arp_oc.h"
#include "arp_module.h"


/** ARP module name.
 */
#define NAME  "arp"

/** ARP global data.
 */
arp_globals_t	arp_globals;

/** Clears the device specific data.
 *  @param[in] device The device specific data.
 */
void arp_clear_device(arp_device_ref device);

/** Creates new protocol specific data.
 *  Allocates and returns the needed memory block as the proto parameter.
 *  @param[out] proto The allocated protocol specific data.
 *  @param[in] service The protocol module service.
 *  @param[in] address The actual protocol device address.
 *  @returns EOK on success.
 *  @returns ENOMEM if there is not enough memory left.
 */
int arp_proto_create(arp_proto_ref * proto, services_t service, measured_string_ref address);

/** @name Message processing functions
 */
/*@{*/

/** Registers the device.
 *  Creates new device entry in the cache or updates the protocol address if the device with the device identifier and the driver service exists.
 *  @param[in] device_id The device identifier.
 *  @param[in] service The device driver service.
 *  @param[in] protocol The protocol service.
 *  @param[in] address The actual device protocol address.
 *  @returns EOK on success.
 *  @returns EEXIST if another device with the same device identifier and different driver service exists.
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns Other error codes as defined for the measured_strings_return() function.
 */
int arp_device_message(device_id_t device_id, services_t service, services_t protocol, measured_string_ref address);

/** Updates the device content length according to the new MTU value.
 *  @param[in] device_id The device identifier.
 *  @param[in] mtu The new mtu value.
 *  @returns ENOENT if device is not found.
 *  @returns EOK on success.
 */
int arp_mtu_changed_message(device_id_t device_id, size_t mtu);

/** Processes the received ARP packet.
 *  Updates the source hardware address if the source entry exists or the packet is targeted to my protocol address.
 *  Responses to the ARP request if the packet is the ARP request and is targeted to my address.
 *  @param[in] device_id The source device identifier.
 *  @param[in,out] packet The received packet.
 *  @returns EOK on success and the packet is no longer needed.
 *  @returns 1 on success and the packet has been reused.
 *  @returns EINVAL if the packet is too small to carry an ARP packet.
 *  @returns EINVAL if the received address lengths differs from the registered values.
 *  @returns ENOENT if the device is not found in the cache.
 *  @returns ENOENT if the protocol for the device is not found in the cache.
 *  @returns ENOMEM if there is not enough memory left.
 */
int arp_receive_message(device_id_t device_id, packet_t packet);

/** Returns the hardware address for the given protocol address.
 *  Sends the ARP request packet if the hardware address is not found in the cache.
 *  @param[in] device_id The device identifier.
 *  @param[in] protocol The protocol service.
 *  @param[in] target The target protocol address.
 *  @returns The hardware address of the target.
 *  @returns NULL if the target parameter is NULL.
 *  @returns NULL if the device is not found.
 *  @returns NULL if the device packet is too small to send a&nbsp;request.
 *  @returns NULL if the hardware address is not found in the cache.
 */
measured_string_ref arp_translate_message(device_id_t device_id, services_t protocol, measured_string_ref target);

/*@}*/

DEVICE_MAP_IMPLEMENT(arp_cache, arp_device_t)

INT_MAP_IMPLEMENT(arp_protos, arp_proto_t)

GENERIC_CHAR_MAP_IMPLEMENT(arp_addr, measured_string_t)

int arp_clean_cache_req(int arp_phone){
	int count;
	arp_device_ref device;

	fibril_rwlock_write_lock(&arp_globals.lock);
	for(count = arp_cache_count(&arp_globals.cache) - 1; count >= 0; -- count){
		device = arp_cache_get_index(&arp_globals.cache, count);
		if(device){
			arp_clear_device(device);
			if(device->addr_data){
				free(device->addr_data);
			}
			if(device->broadcast_data){
				free(device->broadcast_data);
			}
		}
	}
	arp_cache_clear(&arp_globals.cache);
	fibril_rwlock_write_unlock(&arp_globals.lock);
	printf("Cache cleaned\n");
	return EOK;
}

int arp_clear_address_req(int arp_phone, device_id_t device_id, services_t protocol, measured_string_ref address){
	arp_device_ref device;
	arp_proto_ref proto;

	fibril_rwlock_write_lock(&arp_globals.lock);
	device = arp_cache_find(&arp_globals.cache, device_id);
	if(! device){
		fibril_rwlock_write_unlock(&arp_globals.lock);
		return ENOENT;
	}
	proto = arp_protos_find(&device->protos, protocol);
	if(! proto){
		fibril_rwlock_write_unlock(&arp_globals.lock);
		return ENOENT;
	}
	arp_addr_exclude(&proto->addresses, address->value, address->length);
	fibril_rwlock_write_unlock(&arp_globals.lock);
	return EOK;
}

void arp_clear_device(arp_device_ref device){
	int count;
	arp_proto_ref proto;

	for(count = arp_protos_count(&device->protos) - 1; count >= 0; -- count){
		proto = arp_protos_get_index(&device->protos, count);
		if(proto){
			if(proto->addr){
				free(proto->addr);
			}
			if(proto->addr_data){
				free(proto->addr_data);
			}
			arp_addr_destroy(&proto->addresses);
		}
	}
	arp_protos_clear(&device->protos);
}

int arp_clear_device_req(int arp_phone, device_id_t device_id){
	arp_device_ref device;

	fibril_rwlock_write_lock(&arp_globals.lock);
	device = arp_cache_find(&arp_globals.cache, device_id);
	if(! device){
		fibril_rwlock_write_unlock(&arp_globals.lock);
		return ENOENT;
	}
	arp_clear_device(device);
	printf("Device %d cleared\n", device_id);
	fibril_rwlock_write_unlock(&arp_globals.lock);
	return EOK;
}

int arp_connect_module(services_t service){
	if(service != SERVICE_ARP){
		return EINVAL;
	}
	return EOK;
}

int arp_device_message(device_id_t device_id, services_t service, services_t protocol, measured_string_ref address){
	ERROR_DECLARE;

	arp_device_ref device;
	arp_proto_ref proto;
	int index;
	hw_type_t hardware;

	fibril_rwlock_write_lock(&arp_globals.lock);
	// an existing device?
	device = arp_cache_find(&arp_globals.cache, device_id);
	if(device){
		if(device->service != service){
			printf("Device %d already exists\n", device->device_id);
			fibril_rwlock_write_unlock(&arp_globals.lock);
			return EEXIST;
		}
		proto = arp_protos_find(&device->protos, protocol);
		if(proto){
			free(proto->addr);
			free(proto->addr_data);
			proto->addr = address;
			proto->addr_data = address->value;
		}else{
			if(ERROR_OCCURRED(arp_proto_create(&proto, protocol, address))){
				fibril_rwlock_write_unlock(&arp_globals.lock);
				return ERROR_CODE;
			}
			index = arp_protos_add(&device->protos, proto->service, proto);
			if(index < 0){
				fibril_rwlock_write_unlock(&arp_globals.lock);
				free(proto);
				return index;
			}
			printf("New protocol added:\n\tdevice id\t= %d\n\tproto\t= %d", device_id, protocol);
		}
	}else{
		hardware = hardware_map(service);
		if(! hardware){
			return ENOENT;
		}
		// create a new device
		device = (arp_device_ref) malloc(sizeof(arp_device_t));
		if(! device){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			return ENOMEM;
		}
		device->hardware = hardware;
		device->device_id = device_id;
		if(ERROR_OCCURRED(arp_protos_initialize(&device->protos))
			|| ERROR_OCCURRED(arp_proto_create(&proto, protocol, address))){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			free(device);
			return ERROR_CODE;
		}
		index = arp_protos_add(&device->protos, proto->service, proto);
		if(index < 0){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			arp_protos_destroy(&device->protos);
			free(device);
			return index;
		}
		device->service = service;
		// bind the new one
		device->phone = nil_bind_service(device->service, (ipcarg_t) device->device_id, SERVICE_ARP, arp_globals.client_connection);
		if(device->phone < 0){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			arp_protos_destroy(&device->protos);
			free(device);
			return EREFUSED;
		}
		// get packet dimensions
		if(ERROR_OCCURRED(nil_packet_size_req(device->phone, device_id, &device->packet_dimension))){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			arp_protos_destroy(&device->protos);
			free(device);
			return ERROR_CODE;
		}
		// get hardware address
		if(ERROR_OCCURRED(nil_get_addr_req(device->phone, device_id, &device->addr, &device->addr_data))){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			arp_protos_destroy(&device->protos);
			free(device);
			return ERROR_CODE;
		}
		// get broadcast address
		if(ERROR_OCCURRED(nil_get_broadcast_addr_req(device->phone, device_id, &device->broadcast_addr, &device->broadcast_data))){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			free(device->addr);
			free(device->addr_data);
			arp_protos_destroy(&device->protos);
			free(device);
			return ERROR_CODE;
		}
		if(ERROR_OCCURRED(arp_cache_add(&arp_globals.cache, device->device_id, device))){
			fibril_rwlock_write_unlock(&arp_globals.lock);
			free(device->addr);
			free(device->addr_data);
			free(device->broadcast_addr);
			free(device->broadcast_data);
			arp_protos_destroy(&device->protos);
			free(device);
			return ERROR_CODE;
		}
		printf("%s: Device registered (id: %d, type: 0x%x, service: %d, proto: %d)\n",
		    NAME, device->device_id, device->hardware, device->service, protocol);
	}
	fibril_rwlock_write_unlock(&arp_globals.lock);
	return EOK;
}

int arp_device_req(int arp_phone, device_id_t device_id, services_t protocol, services_t netif, measured_string_ref address){
	ERROR_DECLARE;

	measured_string_ref tmp;

	// copy the given address for exclusive use
	tmp = measured_string_copy(address);
	if(ERROR_OCCURRED(arp_device_message(device_id, netif, protocol, tmp))){
		free(tmp->value);
		free(tmp);
	}
	return ERROR_CODE;
}

int arp_initialize(async_client_conn_t client_connection){
	ERROR_DECLARE;

	fibril_rwlock_initialize(&arp_globals.lock);
	fibril_rwlock_write_lock(&arp_globals.lock);
	arp_globals.client_connection = client_connection;
	ERROR_PROPAGATE(arp_cache_initialize(&arp_globals.cache));
	fibril_rwlock_write_unlock(&arp_globals.lock);
	return EOK;
}

int arp_message_standalone(ipc_callid_t callid, ipc_call_t *call,
    ipc_call_t *answer, int *answer_count)
{
	ERROR_DECLARE;
	
	measured_string_ref address;
	measured_string_ref translation;
	char * data;
	packet_t packet;
	packet_t next;
	
	*answer_count = 0;
	switch (IPC_GET_METHOD(*call)) {
		case IPC_M_PHONE_HUNGUP:
			return EOK;
		case NET_ARP_DEVICE:
			ERROR_PROPAGATE(measured_strings_receive(&address, &data, 1));
			if(ERROR_OCCURRED(arp_device_message(IPC_GET_DEVICE(call), IPC_GET_SERVICE(call), ARP_GET_NETIF(call), address))){
				free(address);
				free(data);
			}
			return ERROR_CODE;
		case NET_ARP_TRANSLATE:
			ERROR_PROPAGATE(measured_strings_receive(&address, &data, 1));
			fibril_rwlock_read_lock(&arp_globals.lock);
			translation = arp_translate_message(IPC_GET_DEVICE(call), IPC_GET_SERVICE(call), address);
			free(address);
			free(data);
			if(! translation){
				fibril_rwlock_read_unlock(&arp_globals.lock);
				return ENOENT;
			}
			ERROR_CODE = measured_strings_reply(translation, 1);
			fibril_rwlock_read_unlock(&arp_globals.lock);
			return ERROR_CODE;
		case NET_ARP_CLEAR_DEVICE:
			return arp_clear_device_req(0, IPC_GET_DEVICE(call));
		case NET_ARP_CLEAR_ADDRESS:
			ERROR_PROPAGATE(measured_strings_receive(&address, &data, 1));
			arp_clear_address_req(0, IPC_GET_DEVICE(call), IPC_GET_SERVICE(call), address);
			free(address);
			free(data);
			return EOK;
		case NET_ARP_CLEAN_CACHE:
			return arp_clean_cache_req(0);
		case NET_IL_DEVICE_STATE:
			// do nothing - keep the cache
			return EOK;
		case NET_IL_RECEIVED:
			if(! ERROR_OCCURRED(packet_translate_remote(arp_globals.net_phone, &packet, IPC_GET_PACKET(call)))){
				fibril_rwlock_read_lock(&arp_globals.lock);
				do{
					next = pq_detach(packet);
					ERROR_CODE = arp_receive_message(IPC_GET_DEVICE(call), packet);
					if(ERROR_CODE != 1){
						pq_release_remote(arp_globals.net_phone, packet_get_id(packet));
					}
					packet = next;
				}while(packet);
				fibril_rwlock_read_unlock(&arp_globals.lock);
			}
			return ERROR_CODE;
		case NET_IL_MTU_CHANGED:
			return arp_mtu_changed_message(IPC_GET_DEVICE(call), IPC_GET_MTU(call));
	}
	
	return ENOTSUP;
}

int arp_mtu_changed_message(device_id_t device_id, size_t mtu){
	arp_device_ref device;

	fibril_rwlock_write_lock(&arp_globals.lock);
	device = arp_cache_find(&arp_globals.cache, device_id);
	if(! device){
		fibril_rwlock_write_unlock(&arp_globals.lock);
		return ENOENT;
	}
	device->packet_dimension.content = mtu;
	printf("arp - device %d changed mtu to %d\n\n", device_id, mtu);
	fibril_rwlock_write_unlock(&arp_globals.lock);
	return EOK;
}

int arp_proto_create(arp_proto_ref * proto, services_t service, measured_string_ref address){
	ERROR_DECLARE;

	*proto = (arp_proto_ref) malloc(sizeof(arp_proto_t));
	if(!(*proto)){
		return ENOMEM;
	}
	(** proto).service = service;
	(** proto).addr = address;
	(** proto).addr_data = address->value;
	if(ERROR_OCCURRED(arp_addr_initialize(&(** proto).addresses))){
		free(*proto);
		return ERROR_CODE;
	}
	return EOK;
}

int arp_receive_message(device_id_t device_id, packet_t packet){
	ERROR_DECLARE;

	size_t length;
	arp_header_ref header;
	arp_device_ref device;
	arp_proto_ref proto;
	measured_string_ref hw_source;
	uint8_t * src_hw;
	uint8_t * src_proto;
	uint8_t * des_hw;
	uint8_t * des_proto;

	length = packet_get_data_length(packet);
	if(length <= sizeof(arp_header_t)){
		return EINVAL;
	}
	device = arp_cache_find(&arp_globals.cache, device_id);
	if(! device){
		return ENOENT;
	}
	header = (arp_header_ref) packet_get_data(packet);
	if((ntohs(header->hardware) != device->hardware)
		|| (length < sizeof(arp_header_t) + header->hardware_length * 2u + header->protocol_length * 2u)){
		return EINVAL;
	}
	proto = arp_protos_find(&device->protos, protocol_unmap(device->service, ntohs(header->protocol)));
	if(! proto){
		return ENOENT;
	}
	src_hw = ((uint8_t *) header) + sizeof(arp_header_t);
	src_proto = src_hw + header->hardware_length;
	des_hw = src_proto + header->protocol_length;
	des_proto = des_hw + header->hardware_length;
	hw_source = arp_addr_find(&proto->addresses, (char *) src_proto, CONVERT_SIZE(uint8_t, char, header->protocol_length));
	// exists?
	if(hw_source){
		if(hw_source->length != CONVERT_SIZE(uint8_t, char, header->hardware_length)){
			return EINVAL;
		}
		memcpy(hw_source->value, src_hw, hw_source->length);
	}
	// is my protocol address?
	if(proto->addr->length != CONVERT_SIZE(uint8_t, char, header->protocol_length)){
		return EINVAL;
	}
	if(! str_lcmp(proto->addr->value, (char *) des_proto, proto->addr->length)){
		// not already upadted?
		if(! hw_source){
			hw_source = measured_string_create_bulk((char *) src_hw, CONVERT_SIZE(uint8_t, char, header->hardware_length));
			if(! hw_source){
				return ENOMEM;
			}
			ERROR_PROPAGATE(arp_addr_add(&proto->addresses, (char *) src_proto, CONVERT_SIZE(uint8_t, char, header->protocol_length), hw_source));
		}
		if(ntohs(header->operation) == ARPOP_REQUEST){
			header->operation = htons(ARPOP_REPLY);
			memcpy(des_proto, src_proto, header->protocol_length);
			memcpy(src_proto, proto->addr->value, header->protocol_length);
			memcpy(src_hw, device->addr->value, device->packet_dimension.addr_len);
			memcpy(des_hw, hw_source->value, header->hardware_length);
			ERROR_PROPAGATE(packet_set_addr(packet, src_hw, des_hw, header->hardware_length));
			nil_send_msg(device->phone, device_id, packet, SERVICE_ARP);
			return 1;
		}
	}
	return EOK;
}

task_id_t arp_task_get_id(void){
	return task_get_id();
}

measured_string_ref arp_translate_message(device_id_t device_id, services_t protocol, measured_string_ref target){
	arp_device_ref device;
	arp_proto_ref proto;
	measured_string_ref addr;
	size_t length;
	packet_t packet;
	arp_header_ref header;

	if(! target){
		return NULL;
	}
	device = arp_cache_find(&arp_globals.cache, device_id);
	if(! device){
		return NULL;
	}
	proto = arp_protos_find(&device->protos, protocol);
	if((! proto) || (proto->addr->length != target->length)){
		return NULL;
	}
	addr = arp_addr_find(&proto->addresses, target->value, target->length);
	if(addr){
		return addr;
	}
	// ARP packet content size = header + (address + translation) * 2
	length = 8 + (CONVERT_SIZE(char, uint8_t, proto->addr->length) + CONVERT_SIZE(char, uint8_t, device->addr->length)) * 2;
	if(length > device->packet_dimension.content){
		return NULL;
	}
	packet = packet_get_4_remote(arp_globals.net_phone, device->packet_dimension.addr_len, device->packet_dimension.prefix, length, device->packet_dimension.suffix);
	if(! packet){
		return NULL;
	}
	header = (arp_header_ref) packet_suffix(packet, length);
	if(! header){
		pq_release_remote(arp_globals.net_phone, packet_get_id(packet));
		return NULL;
	}
	header->hardware = htons(device->hardware);
	header->hardware_length = (uint8_t) device->addr->length;
	header->protocol = htons(protocol_map(device->service, protocol));
	header->protocol_length = (uint8_t) proto->addr->length;
	header->operation = htons(ARPOP_REQUEST);
	length = sizeof(arp_header_t);
	memcpy(((uint8_t *) header) + length, device->addr->value, device->addr->length);
	length += device->addr->length;
	memcpy(((uint8_t *) header) + length, proto->addr->value, proto->addr->length);
	length += proto->addr->length;
	bzero(((uint8_t *) header) + length, device->addr->length);
	length += device->addr->length;
	memcpy(((uint8_t *) header) + length, target->value, target->length);
	if(packet_set_addr(packet, (uint8_t *) device->addr->value, (uint8_t *) device->broadcast_addr->value, CONVERT_SIZE(char, uint8_t, device->addr->length)) != EOK){
		pq_release_remote(arp_globals.net_phone, packet_get_id(packet));
		return NULL;
	}
	nil_send_msg(device->phone, device_id, packet, SERVICE_ARP);
	return NULL;
}

int arp_translate_req(int arp_phone, device_id_t device_id, services_t protocol, measured_string_ref address, measured_string_ref * translation, char ** data){
	measured_string_ref tmp;

	fibril_rwlock_read_lock(&arp_globals.lock);
	tmp = arp_translate_message(device_id, protocol, address);
	if(tmp){
		*translation = measured_string_copy(tmp);
		fibril_rwlock_read_unlock(&arp_globals.lock);
		if(*translation){
			*data = (** translation).value;
			return EOK;
		}else{
			return ENOMEM;
		}
	}else{
		fibril_rwlock_read_unlock(&arp_globals.lock);
		return ENOENT;
	}
}

/** Default thread for new connections.
 *
 *  @param[in] iid The initial message identifier.
 *  @param[in] icall The initial message call structure.
 *
 */
static void il_client_connection(ipc_callid_t iid, ipc_call_t * icall)
{
	/*
	 * Accept the connection
	 *  - Answer the first IPC_M_CONNECT_ME_TO call.
	 */
	ipc_answer_0(iid, EOK);
	
	while(true) {
		ipc_call_t answer;
		int answer_count;
		
		/* Clear the answer structure */
		refresh_answer(&answer, &answer_count);
		
		/* Fetch the next message */
		ipc_call_t call;
		ipc_callid_t callid = async_get_call(&call);
		
		/* Process the message */
		int res = il_module_message_standalone(callid, &call, &answer,
		    &answer_count);
		
		/* End if said to either by the message or the processing result */
		if ((IPC_GET_METHOD(call) == IPC_M_PHONE_HUNGUP) || (res == EHANGUP))
			return;
		
		/* Answer the message */
		answer_call(callid, res, &answer, answer_count);
	}
}

/** Starts the module.
 *
 *  @param argc The count of the command line arguments. Ignored parameter.
 *  @param argv The command line parameters. Ignored parameter.
 *
 *  @returns EOK on success.
 *  @returns Other error codes as defined for each specific module start function.
 *
 */
int main(int argc, char *argv[])
{
	ERROR_DECLARE;
	
	/* Start the module */
	if (ERROR_OCCURRED(il_module_start_standalone(il_client_connection)))
		return ERROR_CODE;
	
	return EOK;
}

/** @}
 */