/*
 * 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 packet
 *  @{
 */

/** @file
 *  Packet server implementation.
 */

#include <align.h>
#include <assert.h>
#include <async.h>
#include <errno.h>
#include <fibril_synch.h>
#include <unistd.h>

#include <ipc/ipc.h>
#include <sys/mman.h>

#include <net_err.h>
#include <net_messages.h>
#include <packet/packet.h>
#include <packet/packet_client.h>
#include <packet/packet_header.h>
#include <packet/packet_messages.h>
#include <packet/packet_server.h>

#define FREE_QUEUES_COUNT	7

/** The default address length reserved for new packets.
 */
#define DEFAULT_ADDR_LEN	32

/** The default prefix reserved for new packets.
 */
#define DEFAULT_PREFIX		64

/** The default suffix reserved for new packets.
 */
#define DEFAULT_SUFFIX		64

/** Packet server global data.
 */
static struct{
	/** Safety lock.
	 */
	fibril_mutex_t lock;
	/** Free packet queues.
	 */
	packet_t free[FREE_QUEUES_COUNT];
	/** Packet length upper bounds of the free packet queues.
	 *  The maximal lengths of packets in each queue in the ascending order.
	 *  The last queue is not limited.
	 */
	size_t sizes[FREE_QUEUES_COUNT];
	/** Total packets allocated.
	 */
	unsigned int count;
} ps_globals = {
	.lock = {
		.counter = 1,
		.waiters = {
			.prev = &ps_globals.lock.waiters,
			.next = &ps_globals.lock.waiters,
		}
	},
	.free = {NULL, NULL, NULL, NULL, NULL, NULL, NULL},
	.sizes = {PAGE_SIZE, PAGE_SIZE * 2, PAGE_SIZE * 4, PAGE_SIZE * 8, PAGE_SIZE * 16, PAGE_SIZE * 32, PAGE_SIZE * 64},
	.count = 0
};

int packet_translate_local(int phone, packet_ref packet, packet_id_t packet_id)
{
	if (!packet)
		return EINVAL;
	
	*packet = pm_find(packet_id);
	return (*packet) ? EOK : ENOENT;
}

/** Clears and initializes the packet according to the given dimensions.
 *  @param[in] packet The packet to be initialized.
 *  @param[in] addr_len The source and destination addresses maximal length in bytes.
 *  @param[in] max_prefix The maximal prefix length in bytes.
 *  @param[in] max_content The maximal content length in bytes.
 *  @param[in] max_suffix The maximal suffix length in bytes.
 */
static void packet_init(packet_t packet, size_t addr_len, size_t max_prefix, size_t max_content, size_t max_suffix){
	// clear the packet content
	bzero(((void *) packet) + sizeof(struct packet), packet->length - sizeof(struct packet));
	// clear the packet header
	packet->order = 0;
	packet->metric = 0;
	packet->previous = 0;
	packet->next = 0;
	packet->addr_len = 0;
	packet->src_addr = sizeof(struct packet);
	packet->dest_addr = packet->src_addr + addr_len;
	packet->max_prefix = max_prefix;
	packet->max_content = max_content;
	packet->data_start = packet->dest_addr + addr_len + packet->max_prefix;
	packet->data_end = packet->data_start;
}

/** Creates a&nbsp;new packet of dimensions at least as given.
 *  Should be used only when the global data are locked.
 *  @param[in] length The total length of the packet, including the header, the addresses and the data of the packet.
 *  @param[in] addr_len The source and destination addresses maximal length in bytes.
 *  @param[in] max_prefix The maximal prefix length in bytes.
 *  @param[in] max_content The maximal content length in bytes.
 *  @param[in] max_suffix The maximal suffix length in bytes.
 *  @returns The packet of dimensions at least as given.
 *  @returns NULL if there is not enough memory left.
 */
static packet_t packet_create(size_t length, size_t addr_len, size_t max_prefix, size_t max_content, size_t max_suffix){
	ERROR_DECLARE;

	packet_t packet;

	// already locked
	packet = (packet_t) mmap(NULL, length, PROTO_READ | PROTO_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
	if(packet == MAP_FAILED){
		return NULL;
	}
	++ ps_globals.count;
	packet->packet_id = ps_globals.count;
	packet->length = length;
	packet_init(packet, addr_len, max_prefix, max_content, max_suffix);
	packet->magic_value = PACKET_MAGIC_VALUE;
	if(ERROR_OCCURRED(pm_add(packet))){
		munmap(packet, packet->length);
		return NULL;
	}
	return packet;
}

/** Return the packet of dimensions at least as given.
 *
 * Try to reuse free packets first.
 * Create a new packet aligned to the memory page size if none available.
 * Lock the global data during its processing.
 *
 * @param[in] addr_len    The source and destination addresses
 *                        maximal length in bytes.
 * @param[in] max_prefix  The maximal prefix length in bytes.
 * @param[in] max_content The maximal content length in bytes.
 * @param[in] max_suffix  The maximal suffix length in bytes.
 *
 * @return The packet of dimensions at least as given.
 * @return NULL if there is not enough memory left.
 *
 */
static packet_t packet_get_local(size_t addr_len, size_t max_prefix,
    size_t max_content, size_t max_suffix)
{
	size_t length = ALIGN_UP(sizeof(struct packet) + 2 * addr_len + max_prefix
	    + max_content + max_suffix, PAGE_SIZE);
	
	fibril_mutex_lock(&ps_globals.lock);
	
	packet_t packet;
	unsigned int index;
	
	for (index = 0; index < FREE_QUEUES_COUNT - 1; index++) {
		if (length <= ps_globals.sizes[index]) {
			packet = ps_globals.free[index];
			
			while (packet_is_valid(packet) && (packet->length < length))
				packet = pm_find(packet->next);
			
			if (packet_is_valid(packet)) {
				if (packet == ps_globals.free[index])
					ps_globals.free[index] = pq_detach(packet);
				else
					pq_detach(packet);
				
				packet_init(packet, addr_len, max_prefix, max_content,
				    max_suffix);
				fibril_mutex_unlock(&ps_globals.lock);
				
				return packet;
			}
		}
	}
	
	packet = packet_create(length, addr_len, max_prefix, max_content,
	    max_suffix);
	
	fibril_mutex_unlock(&ps_globals.lock);
	
	return packet;
}

packet_t packet_get_4_local(int phone, size_t max_content, size_t addr_len,
    size_t max_prefix, size_t max_suffix)
{
	return packet_get_local(addr_len, max_prefix, max_content, max_suffix);
}

packet_t packet_get_1_local(int phone, size_t content)
{
	return packet_get_local(DEFAULT_ADDR_LEN, DEFAULT_PREFIX, content,
	    DEFAULT_SUFFIX);
}

/** Release the packet and returns it to the appropriate free packet queue.
 *
 *  Should be used only when the global data are locked.
 *
 *  @param[in] packet The packet to be released.
 *
 */
static void packet_release(packet_t packet){
	int index;
	int result;

	// remove debug dump
//	printf("packet %d released\n", packet->packet_id);
	for(index = 0; (index < FREE_QUEUES_COUNT - 1) && (packet->length > ps_globals.sizes[index]); ++ index);
	result = pq_add(&ps_globals.free[index], packet, packet->length, packet->length);
	assert(result == EOK);
}

/** Releases the packet queue.
 *  @param[in] packet_id The first packet identifier.
 *  @returns EOK on success.
 *  @returns ENOENT if there is no such packet.
 */
static int packet_release_wrapper(packet_id_t packet_id){
	packet_t packet;

	packet = pm_find(packet_id);
	if(! packet_is_valid(packet)){
		return ENOENT;
	}
	fibril_mutex_lock(&ps_globals.lock);
	pq_destroy(packet, packet_release);
	fibril_mutex_unlock(&ps_globals.lock);
	return EOK;
}

void pq_release_local(int phone, packet_id_t packet_id)
{
	(void) packet_release_wrapper(packet_id);
}

/** Shares the packet memory block.
 *  @param[in] packet The packet to be shared.
 *  @returns EOK on success.
 *  @returns EINVAL if the packet is not valid.
 *  @returns EINVAL if the calling module does not accept the memory.
 *  @returns ENOMEM if the desired and actual sizes differ.
 *  @returns Other error codes as defined for the async_share_in_finalize() function.
 */
static int packet_reply(const packet_t packet){
	ipc_callid_t callid;
	size_t size;

	if(! packet_is_valid(packet)){
		return EINVAL;
	}
	if(async_share_in_receive(&callid, &size) <= 0) return EINVAL;
	if(size != packet->length){
		return ENOMEM;
	}
	return async_share_in_finalize(callid, packet, PROTO_READ | PROTO_WRITE);
}

int packet_server_message(ipc_callid_t callid, ipc_call_t * call, ipc_call_t * answer, int * answer_count){
	packet_t packet;

	*answer_count = 0;
	switch(IPC_GET_METHOD(*call)){
		case IPC_M_PHONE_HUNGUP:
			return EOK;
		case NET_PACKET_CREATE_1:
			packet = packet_get_local(DEFAULT_ADDR_LEN, DEFAULT_PREFIX, IPC_GET_CONTENT(call), DEFAULT_SUFFIX);
			if(! packet){
				return ENOMEM;
			}
			*answer_count = 2;
			IPC_SET_ARG1(*answer, (ipcarg_t) packet->packet_id);
			IPC_SET_ARG2(*answer, (ipcarg_t) packet->length);
			return EOK;
		case NET_PACKET_CREATE_4:
			packet = packet_get_local(((DEFAULT_ADDR_LEN < IPC_GET_ADDR_LEN(call)) ? IPC_GET_ADDR_LEN(call) : DEFAULT_ADDR_LEN), DEFAULT_PREFIX + IPC_GET_PREFIX(call), IPC_GET_CONTENT(call), DEFAULT_SUFFIX + IPC_GET_SUFFIX(call));
			if(! packet){
				return ENOMEM;
			}
			*answer_count = 2;
			IPC_SET_ARG1(*answer, (ipcarg_t) packet->packet_id);
			IPC_SET_ARG2(*answer, (ipcarg_t) packet->length);
			return EOK;
		case NET_PACKET_GET:
			packet = pm_find(IPC_GET_ID(call));
			if(! packet_is_valid(packet)){
				return ENOENT;
			}
			return packet_reply(packet);
		case NET_PACKET_GET_SIZE:
			packet = pm_find(IPC_GET_ID(call));
			if(! packet_is_valid(packet)){
				return ENOENT;
			}
			IPC_SET_ARG1(*answer, (ipcarg_t) packet->length);
			*answer_count = 1;
			return EOK;
		case NET_PACKET_RELEASE:
			return packet_release_wrapper(IPC_GET_ID(call));
	}
	return ENOTSUP;
}

/** @}
 */