File content as of revision 0:f09b7bb8bcce:

/**
 * Rapid-prototyping protection schemes with IEC 61850
 *
 * Copyright (c) 2012 Steven Blair
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include "encodePacket.h"
#include "gsePacketData.h"
#include "gseEncode.h"
#include "svEncode.h"

int getGseHeaderLength(struct gseControl *gseControl) {
    int size = 0;
    int len = 0;

    size = strlen((const char *) gseControl->gocbRef);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_INT32U(&gseControl->timeAllowedToLive);
    len += size + getLengthBytes(size) + 1;

    size = strlen((const char *) gseControl->datSet);
    len += size + getLengthBytes(size) + 1;

    size = strlen((const char *) gseControl->goID);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_TIMESTAMP(&gseControl->t);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_INT32U(&gseControl->stNum);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_INT32U(&gseControl->sqNum);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_BOOLEAN(&gseControl->test);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_INT32U(&gseControl->confRev);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_BOOLEAN(&gseControl->ndsCom);
    len += size + getLengthBytes(size) + 1;

    size = BER_GET_LENGTH_CTYPE_INT32U(&gseControl->numDatSetEntries);
    len += size + getLengthBytes(size) + 1;

    size = (gseControl->getDatasetLength)();
    len += size + getLengthBytes(size) + 1;

    return len;
}

// creates a GSE packet, including frame header. returns 0 on fail; number of bytes on success
int gseEncodePacket(struct gseControl *gseControl, unsigned char *buf) {
    int offset = 0;
    int size = 0;
    int ADPULength = getGseHeaderLength(gseControl);
    int len = ADPULength + 9 + getLengthBytes(ADPULength);    // APDU tag size (1 byte), plus 8 "header" bytes

    //printf("ADPULength: %i, len: %i\n", ADPULength, len);

    // frame header
    memcpy(&buf[offset], gseControl->ethHeaderData.destMACAddress, 6);    // destination MAC addresses
    offset += 6;
    memcpy(&buf[offset], LOCAL_MAC_ADDRESS, 6);                        // source MAC addresses
    offset += 6;

    buf[offset++] = 0x81;    // TPID
    buf[offset++] = 0x00;

    netmemcpy(&buf[offset], &gseControl->ethHeaderData.VLAN_ID, 2);    // TCI
    buf[offset] |= (gseControl->ethHeaderData.VLAN_PRIORITY << 5);
    offset += 2;

    buf[offset++] = 0x88;    // EtherType
    buf[offset++] = 0xB8;

    netmemcpy(&buf[offset], &gseControl->ethHeaderData.APPID, 2);    // APPID
    offset += 2;

    netmemcpy(&buf[offset], &len, 2);    // length
    offset += 2;

    buf[offset++] = 0x00;    // reserved 1
    buf[offset++] = 0x00;
    buf[offset++] = 0x00;    // reserved 2
    buf[offset++] = 0x00;

    buf[offset++] = ASN1_TAG_SEQUENCE;
    offset += encodeLength(&buf[offset], ADPULength /*+ getLengthBytes(ADPULength) + 1*/);

    buf[offset++] = GSE_TAG_GOCBREF;
    size = strlen((const char *) gseControl->gocbRef);
    buf[offset++] = size;
    memcpy(&buf[offset], gseControl->gocbRef, size);
    offset += size;

    buf[offset++] = GSE_TAG_TIME_ALLOWED_TO_LIVE;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_INT32U(&gseControl->timeAllowedToLive));
#if GOOSE_FIXED_SIZE == 1
    offset += ber_encode_integer_fixed_size(&buf[offset], &gseControl->timeAllowedToLive, SV_GET_LENGTH_INT32U);
#else
    offset += ber_encode_integer(&buf[offset], &gseControl->timeAllowedToLive, SV_GET_LENGTH_INT32U);
#endif

    buf[offset++] = GSE_TAG_DATSET;
    size = strlen((const char *) gseControl->datSet);
    buf[offset++] = size;
    memcpy(&buf[offset], gseControl->datSet, size);
    offset += size;

    buf[offset++] = GSE_TAG_GOID;
    size = strlen((const char *) gseControl->goID);
    buf[offset++] = size;
    memcpy(&buf[offset], gseControl->goID, size);
    offset += size;

    buf[offset++] = GSE_TAG_T;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_TIMESTAMP(&gseControl->t));
    setTimestamp(&gseControl->t);
    memcpy(&buf[offset], &gseControl->t, BER_GET_LENGTH_CTYPE_TIMESTAMP(&gseControl->t));
    offset += BER_GET_LENGTH_CTYPE_TIMESTAMP(&gseControl->t);

    buf[offset++] = GSE_TAG_STNUM;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_INT32U(&gseControl->stNum));
#if GOOSE_FIXED_SIZE == 1
    offset += ber_encode_integer_fixed_size(&buf[offset], &gseControl->stNum, SV_GET_LENGTH_INT32U);
#else
    offset += ber_encode_integer(&buf[offset], &gseControl->stNum, SV_GET_LENGTH_INT32U);
#endif

    buf[offset++] = GSE_TAG_SQNUM;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_INT32U(&gseControl->sqNum));
#if GOOSE_FIXED_SIZE == 1
    offset += ber_encode_integer_fixed_size(&buf[offset], &gseControl->sqNum, SV_GET_LENGTH_INT32U);
#else
    offset += ber_encode_integer(&buf[offset], &gseControl->sqNum, SV_GET_LENGTH_INT32U);
#endif

    buf[offset++] = GSE_TAG_SIMULATION;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_BOOLEAN(&gseControl->test));
    offset += ber_encode_integer(&buf[offset], &gseControl->test, SV_GET_LENGTH_BOOLEAN);

    buf[offset++] = GSE_TAG_CONFREV;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_INT32U(&gseControl->confRev));
#if GOOSE_FIXED_SIZE == 1
    offset += ber_encode_integer_fixed_size(&buf[offset], &gseControl->confRev, SV_GET_LENGTH_INT32U);
#else
    offset += ber_encode_integer(&buf[offset], &gseControl->confRev, SV_GET_LENGTH_INT32U);
#endif

    buf[offset++] = GSE_TAG_NDSCOM;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_BOOLEAN(&gseControl->ndsCom));
    offset += ber_encode_integer(&buf[offset], &gseControl->ndsCom, SV_GET_LENGTH_BOOLEAN);

    buf[offset++] = GSE_TAG_NUMDATSETENTRIES;
    offset += encodeLength(&buf[offset], BER_GET_LENGTH_CTYPE_INT32U(&gseControl->numDatSetEntries));
#if GOOSE_FIXED_SIZE == 1
    offset += ber_encode_integer_fixed_size(&buf[offset], &gseControl->numDatSetEntries, SV_GET_LENGTH_INT32U);
#else
    offset += ber_encode_integer(&buf[offset], &gseControl->numDatSetEntries, SV_GET_LENGTH_INT32U);
#endif

    buf[offset++] = GSE_TAG_ALLDATA;
    offset += encodeLength(&buf[offset], (gseControl->getDatasetLength)());
    offset += (gseControl->encodeDataset)(&buf[offset]);

    // assume network interface, such as WinPcap, generates CRC bytes

    return offset;
}