source: mainline/uspace/lib/socket/packet/packet.c@ 849ed54

/*
 * 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 map and queue implementation.
 *  This file has to be compiled with both the packet server and the client.
 */

#include <errno.h>
#include <malloc.h>
#include <mem.h>
#include <fibril_synch.h>
#include <unistd.h>

#include <sys/mman.h>

#include <net_err.h>
#include <adt/generic_field.h>
#include <packet/packet.h>
#include <packet/packet_header.h>

/** Packet map page size.
 */
#define PACKET_MAP_SIZE 100

/** Returns the packet map page index.
 *  @param[in] packet_id The packet identifier.
 */
#define PACKET_MAP_PAGE(packet_id)      (((packet_id) - 1) / PACKET_MAP_SIZE)

/** Returns the packet index in the corresponding packet map page.
 *  @param[in] packet_id The packet identifier.
 */
#define PACKET_MAP_INDEX(packet_id)     (((packet_id) - 1) % PACKET_MAP_SIZE)

/** Type definition of the packet map page.
 */
typedef packet_t packet_map_t[PACKET_MAP_SIZE];
/** Type definition of the packet map page pointer.
 */
typedef packet_map_t * packet_map_ref;

/** Packet map.
 *  Maps packet identifiers to the packet references.
 *  @see generic_field.h
 */
GENERIC_FIELD_DECLARE(gpm, packet_map_t);

/** Releases the packet.
 *  @param[in] packet The packet to be released.
 *  @returns EOK on success.
 *  @returns EINVAL if the packet is not valid.
 */
int packet_destroy(packet_t packet);

/** Packet map global data.
 */
static struct{
        /** Safety lock.
         */
        fibril_rwlock_t lock;
        /** Packet map.
         */
        gpm_t packet_map;
} pm_globals;

GENERIC_FIELD_IMPLEMENT(gpm, packet_map_t);

int packet_destroy(packet_t packet){
        if(! packet_is_valid(packet)){
                return EINVAL;
        }
        return munmap(packet, packet->length);
}

int pm_init(void){
        ERROR_DECLARE;

        fibril_rwlock_initialize(&pm_globals.lock);
        fibril_rwlock_write_lock(&pm_globals.lock);
        ERROR_PROPAGATE(gpm_initialize(&pm_globals.packet_map));
        fibril_rwlock_write_unlock(&pm_globals.lock);
        return EOK;
}

packet_t pm_find(packet_id_t packet_id){
        packet_map_ref map;
        packet_t packet;

        if(! packet_id){
                return NULL;
        }
        fibril_rwlock_read_lock(&pm_globals.lock);
        if(packet_id > PACKET_MAP_SIZE * gpm_count(&pm_globals.packet_map)){
                fibril_rwlock_read_unlock(&pm_globals.lock);
                return NULL;
        }
        map = gpm_get_index(&pm_globals.packet_map, PACKET_MAP_PAGE(packet_id));
        if(! map){
                fibril_rwlock_read_unlock(&pm_globals.lock);
                return NULL;
        }
        packet = (*map)[PACKET_MAP_INDEX(packet_id)];
        fibril_rwlock_read_unlock(&pm_globals.lock);
        return packet;
}

int pm_add(packet_t packet){
        ERROR_DECLARE;

        packet_map_ref map;

        if(! packet_is_valid(packet)){
                return EINVAL;
        }
        fibril_rwlock_write_lock(&pm_globals.lock);
        if(PACKET_MAP_PAGE(packet->packet_id) < gpm_count(&pm_globals.packet_map)){
                map = gpm_get_index(&pm_globals.packet_map, PACKET_MAP_PAGE(packet->packet_id));
        }else{
                do{
                        map = (packet_map_ref) malloc(sizeof(packet_map_t));
                        if(! map){
                                fibril_rwlock_write_unlock(&pm_globals.lock);
                                return ENOMEM;
                        }
                        bzero(map, sizeof(packet_map_t));
                        if((ERROR_CODE = gpm_add(&pm_globals.packet_map, map)) < 0){
                                fibril_rwlock_write_unlock(&pm_globals.lock);
                                free(map);
                                return ERROR_CODE;
                        }
                }while(PACKET_MAP_PAGE(packet->packet_id) >= gpm_count(&pm_globals.packet_map));
        }
        (*map)[PACKET_MAP_INDEX(packet->packet_id)] = packet;
        fibril_rwlock_write_unlock(&pm_globals.lock);
        return EOK;
}

void pm_destroy(void){
        int count;
        int index;
        packet_map_ref map;
        packet_t packet;

        fibril_rwlock_write_lock(&pm_globals.lock);
        count = gpm_count(&pm_globals.packet_map);
        while(count > 0){
                map = gpm_get_index(&pm_globals.packet_map, count - 1);
                for(index = PACKET_MAP_SIZE - 1; index >= 0; -- index){
                        packet = (*map)[index];
                        if(packet_is_valid(packet)){
                                munmap(packet, packet->length);
                        }
                }
        }
        gpm_destroy(&pm_globals.packet_map);
        // leave locked
}

int pq_add(packet_t * first, packet_t packet, size_t order, size_t metric){
        packet_t item;

        if((! first) || (! packet_is_valid(packet))){
                return EINVAL;
        }
        pq_set_order(packet, order, metric);
        if(packet_is_valid(*first)){
                item = * first;
                do{
                        if(item->order < order){
                                if(item->next){
                                        item = pm_find(item->next);
                                }else{
                                        item->next = packet->packet_id;
                                        packet->previous = item->packet_id;
                                        return EOK;
                                }
                        }else{
                                packet->previous = item->previous;
                                packet->next = item->packet_id;
                                item->previous = packet->packet_id;
                                item = pm_find(packet->previous);
                                if(item){
                                        item->next = packet->packet_id;
                                }else{
                                        *first = packet;
                                }
                                return EOK;
                        }
                }while(packet_is_valid(item));
        }
        *first = packet;
        return EOK;
}

packet_t pq_find(packet_t packet, size_t order){
        packet_t item;

        if(! packet_is_valid(packet)){
                return NULL;
        }
        item = packet;
        do{
                if(item->order == order){
                        return item;
                }
                item = pm_find(item->next);
        }while(item && (item != packet) && packet_is_valid(item));
        return NULL;
}

int pq_insert_after(packet_t packet, packet_t new_packet){
        packet_t item;

        if(!(packet_is_valid(packet) && packet_is_valid(new_packet))){
                return EINVAL;
        }
        new_packet->previous = packet->packet_id;
        new_packet->next = packet->next;
        item = pm_find(packet->next);
        if(item){
                item->previous = new_packet->packet_id;
        }
        packet->next = new_packet->packet_id;
        return EOK;
}

packet_t pq_detach(packet_t packet){
        packet_t next;
        packet_t previous;

        if(! packet_is_valid(packet)){
                return NULL;
        }
        next = pm_find(packet->next);
        if(next){
                next->previous = packet->previous;
                previous = pm_find(next->previous);
                if(previous){
                        previous->next = next->packet_id;
                }
        }
        packet->previous = 0;
        packet->next = 0;
        return next;
}

int pq_set_order(packet_t packet, size_t order, size_t metric){
        if(! packet_is_valid(packet)){
                return EINVAL;
        }
        packet->order = order;
        packet->metric = metric;
        return EOK;
}

int pq_get_order(packet_t packet, size_t * order, size_t * metric){
        if(! packet_is_valid(packet)){
                return EINVAL;
        }
        if(order){
                *order = packet->order;
        }
        if(metric){
                *metric = packet->metric;
        }
        return EOK;
}

void pq_destroy(packet_t first, void (*packet_release)(packet_t packet)){
        packet_t actual;
        packet_t next;

        actual = first;
        while(packet_is_valid(actual)){
                next = pm_find(actual->next);
                actual->next = 0;
                actual->previous = 0;
                if(packet_release){
                        packet_release(actual);
                }
                actual = next;
        }
}

packet_t pq_next(packet_t packet){
        if(! packet_is_valid(packet)){
                return NULL;
        }
        return pm_find(packet->next);
}

packet_t pq_previous(packet_t packet){
        if(! packet_is_valid(packet)){
                return NULL;
        }
        return pm_find(packet->previous);
}

/** @}
 */