source: mainline/uspace/srv/net/ethip/pdu.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 <byteorder.h>
#include <errno.h>
#include <io/log.h>
#include <macros.h>
#include <mem.h>
#include <stdlib.h>

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

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

        size = max(sizeof(eth_header_t) + frame->size, ETH_FRAME_MIN_SIZE);

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

        hdr = (eth_header_t *)data;
        eth_addr_encode(&frame->src, hdr->src);
        eth_addr_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);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "Encoded Ethernet frame (%zu bytes)", size);

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

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

        log_msg(LOG_DEFAULT, LVL_DEBUG, "eth_pdu_decode()");

        if (size < sizeof(eth_header_t)) {
                log_msg(LOG_DEFAULT, 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;

        eth_addr_decode(hdr->src, &frame->src);
        eth_addr_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);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "Decoded Ethernet frame payload (%zu bytes)", frame->size);

        return EOK;
}

/** Encode ARP PDU. */
errno_t arp_pdu_encode(arp_eth_packet_t *packet, void **rdata, size_t *rsize)
{
        void *data;
        size_t size;
        arp_eth_packet_fmt_t *pfmt;
        uint16_t fopcode;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "arp_pdu_encode()");

        size = sizeof(arp_eth_packet_fmt_t);

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

        pfmt = (arp_eth_packet_fmt_t *)data;

        switch (packet->opcode) {
        case aop_request:
                fopcode = AOP_REQUEST;
                break;
        case aop_reply:
                fopcode = AOP_REPLY;
                break;
        default:
                assert(false);
                fopcode = 0;
        }

        pfmt->hw_addr_space = host2uint16_t_be(AHRD_ETHERNET);
        pfmt->proto_addr_space = host2uint16_t_be(ETYPE_IP);
        pfmt->hw_addr_size = ETH_ADDR_SIZE;
        pfmt->proto_addr_size = IPV4_ADDR_SIZE;
        pfmt->opcode = host2uint16_t_be(fopcode);
        eth_addr_encode(&packet->sender_hw_addr, pfmt->sender_hw_addr);
        pfmt->sender_proto_addr =
            host2uint32_t_be(packet->sender_proto_addr);
        eth_addr_encode(&packet->target_hw_addr, pfmt->target_hw_addr);
        pfmt->target_proto_addr =
            host2uint32_t_be(packet->target_proto_addr);

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

/** Decode ARP PDU. */
errno_t arp_pdu_decode(void *data, size_t size, arp_eth_packet_t *packet)
{
        arp_eth_packet_fmt_t *pfmt;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "arp_pdu_decode()");

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

        pfmt = (arp_eth_packet_fmt_t *)data;

        if (uint16_t_be2host(pfmt->hw_addr_space) != AHRD_ETHERNET) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "HW address space != %u (%" PRIu16 ")",
                    AHRD_ETHERNET, uint16_t_be2host(pfmt->hw_addr_space));
                return EINVAL;
        }

        if (uint16_t_be2host(pfmt->proto_addr_space) != 0x0800) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Proto address space != %u (%" PRIu16 ")",
                    ETYPE_IP, uint16_t_be2host(pfmt->proto_addr_space));
                return EINVAL;
        }

        if (pfmt->hw_addr_size != ETH_ADDR_SIZE) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "HW address size != %zu (%zu)",
                    (size_t)ETH_ADDR_SIZE, (size_t)pfmt->hw_addr_size);
                return EINVAL;
        }

        if (pfmt->proto_addr_size != IPV4_ADDR_SIZE) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Proto address size != %zu (%zu)",
                    (size_t)IPV4_ADDR_SIZE, (size_t)pfmt->proto_addr_size);
                return EINVAL;
        }

        switch (uint16_t_be2host(pfmt->opcode)) {
        case AOP_REQUEST:
                packet->opcode = aop_request;
                break;
        case AOP_REPLY:
                packet->opcode = aop_reply;
                break;
        default:
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Invalid ARP opcode (%" PRIu16 ")",
                    uint16_t_be2host(pfmt->opcode));
                return EINVAL;
        }

        eth_addr_decode(pfmt->sender_hw_addr, &packet->sender_hw_addr);
        packet->sender_proto_addr =
            uint32_t_be2host(pfmt->sender_proto_addr);
        eth_addr_decode(pfmt->target_hw_addr, &packet->target_hw_addr);
        packet->target_proto_addr =
            uint32_t_be2host(pfmt->target_proto_addr);
        log_msg(LOG_DEFAULT, LVL_DEBUG, "packet->tpa = %x\n", pfmt->target_proto_addr);

        return EOK;
}

/** @}
 */