source: mainline/uspace/srv/net/ethip/atrans.c

/*
 * Copyright (c) 2021 Jiri Svoboda
 * 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 inet
 * @{
 */
/**
 * @file
 * @brief
 */

#include <adt/list.h>
#include <errno.h>
#include <fibril_synch.h>
#include <inet/eth_addr.h>
#include <inet/iplink_srv.h>
#include <stdlib.h>

#include "atrans.h"
#include "ethip.h"

/** Address translation list (of ethip_atrans_t) */
static FIBRIL_MUTEX_INITIALIZE(atrans_list_lock);
static LIST_INITIALIZE(atrans_list);
static FIBRIL_CONDVAR_INITIALIZE(atrans_cv);

static ethip_atrans_t *atrans_find(addr32_t ip_addr)
{
        list_foreach(atrans_list, atrans_list, ethip_atrans_t, atrans) {
                if (atrans->ip_addr == ip_addr)
                        return atrans;
        }

        return NULL;
}

errno_t atrans_add(addr32_t ip_addr, eth_addr_t *mac_addr)
{
        ethip_atrans_t *atrans;
        ethip_atrans_t *prev;

        atrans = calloc(1, sizeof(ethip_atrans_t));
        if (atrans == NULL)
                return ENOMEM;

        atrans->ip_addr = ip_addr;
        atrans->mac_addr = *mac_addr;

        fibril_mutex_lock(&atrans_list_lock);
        prev = atrans_find(ip_addr);
        if (prev != NULL) {
                list_remove(&prev->atrans_list);
                free(prev);
        }

        list_append(&atrans->atrans_list, &atrans_list);
        fibril_mutex_unlock(&atrans_list_lock);
        fibril_condvar_broadcast(&atrans_cv);

        return EOK;
}

errno_t atrans_remove(addr32_t ip_addr)
{
        ethip_atrans_t *atrans;

        fibril_mutex_lock(&atrans_list_lock);
        atrans = atrans_find(ip_addr);
        if (atrans == NULL) {
                fibril_mutex_unlock(&atrans_list_lock);
                return ENOENT;
        }

        list_remove(&atrans->atrans_list);
        fibril_mutex_unlock(&atrans_list_lock);
        free(atrans);

        return EOK;
}

static errno_t atrans_lookup_locked(addr32_t ip_addr, eth_addr_t *mac_addr)
{
        ethip_atrans_t *atrans = atrans_find(ip_addr);
        if (atrans == NULL)
                return ENOENT;

        *mac_addr = atrans->mac_addr;
        return EOK;
}

errno_t atrans_lookup(addr32_t ip_addr, eth_addr_t *mac_addr)
{
        errno_t rc;

        fibril_mutex_lock(&atrans_list_lock);
        rc = atrans_lookup_locked(ip_addr, mac_addr);
        fibril_mutex_unlock(&atrans_list_lock);

        return rc;
}

static void atrans_lookup_timeout_handler(void *arg)
{
        bool *timedout = (bool *)arg;

        fibril_mutex_lock(&atrans_list_lock);
        *timedout = true;
        fibril_mutex_unlock(&atrans_list_lock);
        fibril_condvar_broadcast(&atrans_cv);
}

errno_t atrans_lookup_timeout(addr32_t ip_addr, usec_t timeout,
    eth_addr_t *mac_addr)
{
        fibril_timer_t *t;
        bool timedout;
        errno_t rc;

        t = fibril_timer_create(NULL);
        if (t == NULL)
                return ENOMEM;

        timedout = false;
        fibril_timer_set(t, timeout, atrans_lookup_timeout_handler, &timedout);

        fibril_mutex_lock(&atrans_list_lock);

        while ((rc = atrans_lookup_locked(ip_addr, mac_addr)) == ENOENT &&
            !timedout) {
                fibril_condvar_wait(&atrans_cv, &atrans_list_lock);
        }

        fibril_mutex_unlock(&atrans_list_lock);
        (void) fibril_timer_clear(t);
        fibril_timer_destroy(t);

        return rc;
}

/** @}
 */