source: mainline/uspace/srv/ethip/pdu.c@ 1493811

/*
 * Copyright (c) 2012 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 <byteorder.h>
#include <errno.h>
#include <io/log.h>
#include <mem.h>
#include <stdlib.h>

#include "ethip.h"
#include "std.h"
#include "pdu.h"

static void mac48_encode(mac48_addr_t *addr, void *buf);
static void mac48_decode(void *data, mac48_addr_t *addr);

#define MAC48_BYTES 6

/** Encode Ethernet PDU. */
int eth_pdu_encode(eth_frame_t *frame, void **rdata, size_t *rsize)
{
        void *data;
        size_t size;
        eth_header_t *hdr;

        size = sizeof(eth_header_t) + frame->size;

        data = calloc(size, 1);
        if (data == NULL)
                return ENOMEM;

        hdr = (eth_header_t *)data;
        mac48_encode(&frame->src, hdr->src);
        mac48_encode(&frame->dest, hdr->dest);
        hdr->etype_len = host2uint16_t_be(frame->etype_len);

        memcpy((uint8_t *)data + sizeof(eth_header_t), frame->data,
            frame->size);

        *rdata = data;
        *rsize = size;
        return EOK;
}

/** Decode Ethernet PDU. */
int eth_pdu_decode(void *data, size_t size, eth_frame_t *frame)
{
        eth_header_t *hdr;

        log_msg(LVL_DEBUG, "eth_pdu_decode()");

        if (size < sizeof(eth_header_t)) {
                log_msg(LVL_DEBUG, "PDU too short (%zu)", size);
                return EINVAL;
        }

        hdr = (eth_header_t *)data;

        frame->size = size - sizeof(eth_header_t);
        frame->data = calloc(frame->size, 1);
        if (frame->data == NULL)
                return ENOMEM;

        mac48_decode(hdr->src, &frame->src);
        mac48_decode(hdr->dest, &frame->dest);
        frame->etype_len = uint16_t_be2host(hdr->etype_len);

        memcpy(frame->data, (uint8_t *)data + sizeof(eth_header_t),
            frame->size);

        return EOK;
}

static void mac48_encode(mac48_addr_t *addr, void *buf)
{
        uint64_t val;
        uint8_t *bbuf = (uint8_t *)buf;
        int i;

        val = addr->addr;
        for (i = 0; i < MAC48_BYTES; i++) {
                bbuf[i] = (val >> 8*(MAC48_BYTES - i - 1)) & 0xff;
                val = val >> 8;
        }
}

static void mac48_decode(void *data, mac48_addr_t *addr)
{
        uint64_t val;
        uint8_t *bdata = (uint8_t *)data;
        int i;

        val = 0;
        for (i = 0; i < MAC48_BYTES; i++)
                val |= ((uint64_t)bdata[i]) << (MAC48_BYTES - i - 1);

        addr->addr = val;
}

/** @}
 */