bacnet_stack/ports/rx62n/ethernet.c

/**************************************************************************
 *
 * Copyright (C) 2011 Steve Karg <skarg@users.sourceforge.net>
 *
 * SPDX-License-Identifier: MIT
 *
 *********************************************************************/
#include <stdint.h> /* for standard integer types uint8_t etc. */
#include <stdbool.h> /* for the standard bool type. */
#include "bacnet/bacdef.h"
#include "bacnet/datalink/ethernet.h"
#include "bacnet/bacint.h"
#include "hardware.h"

/** @file rx62n/ethernet.c  Provides Renesas RX62N-specific functions
    for BACnet/Ethernet. */

/* commonly used comparison address for ethernet */
static uint8_t Ethernet_Broadcast[MAX_MAC_LEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
    0xFF };

/* IEEE maintains list of 48-bit MAC "addresses" AKA EUI-48 identifiers.
   An EUI-48 is structured into an initial 3-octet OUI
   (Organizationally Unique Identifier) and an additional 3 octets
   assigned by the OUI holder. */
/* see [RFC5342] for current information and registration procedures. */
/* The OUI 00-00-5E has been allocated to IANA. */
/* my local device data - MAC address */
static uint8_t Ethernet_MAC_Address[MAX_MAC_LEN] = { 0x00, 0x00, 0x5E, 0x00,
    0x00, 0x01 };

/* status of the link */
static int32_t Ethernet_Status = R_ETHER_ERROR;

bool ethernet_valid(void)
{
    if (Ethernet_Status != R_ETHER_OK) {
        Ethernet_Status = R_Ether_Open(0, Ethernet_MAC_Address);
    }

    return (Ethernet_Status != R_ETHER_ERROR);
}

void ethernet_cleanup(void)
{
    R_Ether_Close(0);
    Ethernet_Status = R_ETHER_ERROR;

    return;
}

bool ethernet_init(char *interface_name)
{
    interface_name = interface_name;
    Ethernet_Status = R_Ether_Open(0, Ethernet_MAC_Address);

    return (Ethernet_Status == R_ETHER_OK);
}

int ethernet_send(uint8_t *mtu, int mtu_len)
{
    int bytes = 0;

    /* Send the packet */
    bytes = R_Ether_Write(0, mtu, mtu_len);

    return bytes;
}

/* function to send a packet out the 802.2 socket */
/* returns number of bytes sent on success, negative on failure */
int ethernet_send_pdu(BACNET_ADDRESS *dest, /* destination address */
    BACNET_NPDU_DATA *npdu_data, /* network information */
    uint8_t *pdu, /* any data to be sent - may be null */
    unsigned pdu_len)
{ /* number of bytes of data */
    int i = 0; /* counter */
    int bytes = 0;
    BACNET_ADDRESS src = { 0 }; /* source address for npdu */
    uint8_t mtu[ETHERNET_MPDU_MAX] = { 0 }; /* our buffer */
    int mtu_len = 0;

    (void)npdu_data;
    /* load the BACnet address for NPDU data */
    for (i = 0; i < 6; i++) {
        src.mac[i] = Ethernet_MAC_Address[i];
        src.mac_len++;
    }

    /* don't waste time if the socket is not valid */
    if (!ethernet_valid()) {
        return -1;
    }
    /* load destination ethernet MAC address */
    if (dest->mac_len == 6) {
        for (i = 0; i < 6; i++) {
            mtu[i] = dest->mac[i];
        }
    } else {
        return -2;
    }

    /* load source ethernet MAC address */
    if (src.mac_len == 6) {
        for (i = 0; i < 6; i++) {
            mtu[6 + i] = src.mac[i];
        }
    } else {
        return -3;
    }
    /* Logical PDU portion */
    mtu[14] = 0x82; /* DSAP for BACnet */
    mtu[15] = 0x82; /* SSAP for BACnet */
    mtu[16] = 0x03; /* Control byte in header */
    mtu_len = 17;
    if ((mtu_len + pdu_len) > ETHERNET_MPDU_MAX) {
        return -4;
    }
    memcpy(&mtu[mtu_len], pdu, pdu_len);
    mtu_len += pdu_len;
    /* packet length - only the logical portion, not the address */
    encode_unsigned16(&mtu[12], 3 + pdu_len);

    /* Send the packet */
    bytes = R_Ether_Write(0, mtu, mtu_len);

    return bytes;
}

/* receives an 802.2 framed packet */
/* returns the number of octets in the PDU, or zero on failure */
uint16_t ethernet_receive(BACNET_ADDRESS *src, /* source address */
    uint8_t *pdu, /* PDU data */
    uint16_t max_pdu, /* amount of space available in the PDU  */
    unsigned timeout)
{ /* number of milliseconds to wait for a packet */
    int received_bytes;
    uint8_t buf[ETHERNET_MPDU_MAX] = { 0 }; /* data */
    uint16_t pdu_len = 0; /* return value */

    /* Make sure the socket is open */
    if (!ethernet_valid())
        return 0;

    received_bytes = R_Ether_Read(0, (void *)buf);

    if (received_bytes == 0)
        return 0;

    /* the signature of an 802.2 BACnet packet */
    if ((buf[14] != 0x82) && (buf[15] != 0x82)) {
        return 0;
    }
    /* copy the source address */
    src->mac_len = 6;
    memmove(src->mac, &buf[6], 6);

    /* check destination address for when */
    /* the Ethernet card is in promiscious mode */
    if ((memcmp(&buf[0], Ethernet_MAC_Address, 6) != 0) &&
        (memcmp(&buf[0], Ethernet_Broadcast, 6) != 0)) {
        return 0;
    }

    (void)decode_unsigned16(&buf[12], &pdu_len);
    pdu_len -= 3 /* DSAP, SSAP, LLC Control */;
    /* copy the buffer into the PDU */
    if (pdu_len < max_pdu)
        memmove(&pdu[0], &buf[17], pdu_len);
    /* ignore packets that are too large */
    else
        pdu_len = 0;

    return pdu_len;
}

void ethernet_set_my_address(BACNET_ADDRESS *my_address)
{
    int i = 0;

    for (i = 0; i < 6; i++) {
        Ethernet_MAC_Address[i] = my_address->mac[i];
    }

    return;
}

void ethernet_get_my_address(BACNET_ADDRESS *my_address)
{
    int i = 0;

    my_address->mac_len = 0;
    for (i = 0; i < 6; i++) {
        my_address->mac[i] = Ethernet_MAC_Address[i];
        my_address->mac_len++;
    }
    my_address->net = 0; /* DNET=0 is local only, no routing */
    my_address->len = 0;
    for (i = 0; i < MAX_MAC_LEN; i++) {
        my_address->adr[i] = 0;
    }

    return;
}

void ethernet_get_broadcast_address(BACNET_ADDRESS *dest)
{ /* destination address */
    int i = 0; /* counter */

    if (dest) {
        for (i = 0; i < 6; i++) {
            dest->mac[i] = Ethernet_Broadcast[i];
        }
        dest->mac_len = 6;
        dest->net = BACNET_BROADCAST_NETWORK;
        dest->len = 0; /* always zero when DNET is broadcast */
        for (i = 0; i < MAX_MAC_LEN; i++) {
            dest->adr[i] = 0;
        }
    }

    return;
}