gnapbus.c

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/* (c) 2006 by Marcin Wiacek */

#include "../../gsmstate.h"

#if defined(GSM_ENABLE_BLUEGNAPBUS) || defined(GSM_ENABLE_IRDAGNAPBUS)

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "../../gsmcomon.h"
#include "gnapbus.h"

static GSM_Error GNAPBUS_WriteMessage (GSM_StateMachine *s, unsigned const char *MsgBuffer,
                                    int MsgLength, int MsgType)
{
        unsigned char   *buffer=NULL;
        int             sent=0,length=0,i=0;
        unsigned char   checksum=0;

        GSM_DumpMessageBinary(s, MsgBuffer, MsgLength, MsgType);

        buffer = (unsigned char *)malloc(MsgLength + 10);

        buffer[0] = GNAPBUS_FRAME_ID,
        buffer[1] = 0x00;
        buffer[2] = MsgLength / 256;
        buffer[3] = MsgLength % 256;
        buffer[4] = MsgType;
        buffer[5] = 0x00;
        memcpy(buffer + 6, MsgBuffer, MsgLength);
        length = MsgLength+6;

        if (MsgLength & 1) buffer[length++] = 0x00;
        /* Odd messages require additional 0x00 byte */
/*      if (MsgLength % 2) buffer[length++] = 0x00; */

        checksum        = 0;
        for (i = 0; i < length; i+=2) checksum ^= buffer[i];
        buffer[length++]        = checksum;

        checksum        = 0;
        for (i = 1; i < length; i+=2) checksum ^= buffer[i];
        buffer[length++]        = checksum;

/*      GSM_DumpMessageText(s, buffer, length, MsgType); */
        GSM_DumpMessageText(s, MsgBuffer, MsgLength, MsgType);

        /* Sending to phone */
        sent = s->Device.Functions->WriteDevice(s,buffer,length);
        free(buffer);
        buffer=NULL;

        if (sent!=length) {
                return ERR_DEVICEWRITEERROR;
        }
        return ERR_NONE;
}

static GSM_Error GNAPBUS_StateMachine(GSM_StateMachine *s, unsigned char rx_char)
{
        GSM_Protocol_GNAPBUSData *d = &s->Protocol.Data.GNAPBUS;

/* printf("%02x ",rx_char); */
/* fflush(stdout); */
        /* XOR the byte with the earlier checksum */
        d->Msg.CheckSum[d->Msg.Count & 1] ^= rx_char;

        switch (d->MsgRXState) {
        case RX_Sync:
                if (rx_char == GNAPBUS_FRAME_ID) {
                        d->MsgRXState = RX_GetDestination;
                        d->Msg.Count = 0;
                        d->Msg.Length = 0;
                        d->Msg.CheckSum[0] = rx_char;
                        d->Msg.CheckSum[1] = 0;
                } else smprintf(s,"Sync error: %02x\n",rx_char);
                break;
        case RX_GetDestination:
                d->MsgRXState = RX_GetLength1;
                break;
        case RX_GetLength1:
                d->MsgRXState = RX_GetLength2;
                d->Msg.Length = rx_char << 8;
                break;
        case RX_GetLength2:
                d->MsgRXState = RX_GetType;
                d->Msg.Length += rx_char;
                d->Msg.Buffer   = (unsigned char *)malloc(d->Msg.Length+3);
                break;
        case RX_GetType:
                d->MsgRXState = RX_GetSource;
                d->Msg.Type = rx_char;
                break;
        case RX_GetSource:
                d->MsgRXState = RX_GetMessage;
                break;
        case RX_GetMessage:
                d->Msg.Buffer[d->Msg.Count] = rx_char;
                d->Msg.Count++;

                if (d->Msg.Count != ((d->Msg.Length+3)& ~1)) return ERR_NONE;

/*      GSM_DumpMessageText(s, d->Msg.Buffer, d->Msg.Count, d->Msg.Type); */
/* printf("\n%02x %02x\n",d->Msg.CheckSum[0],d->Msg.CheckSum[1]); */
                /* Checksum is incorrect */
                if (d->Msg.CheckSum[0] != d->Msg.CheckSum[1]) {
                        if (s->di.dl==DL_TEXT || s->di.dl==DL_TEXTALL || s->di.dl==DL_TEXTERROR ||
                            s->di.dl==DL_TEXTDATE || s->di.dl==DL_TEXTALLDATE || s->di.dl==DL_TEXTERRORDATE) {
                                smprintf(s,"[ERROR: checksum]\n");
                        }
                        free(d->Msg.Buffer);
                        d->Msg.Buffer = NULL;
                        d->Msg.Length = 0;
                        d->MsgRXState = RX_Sync;
                        return ERR_NONE;
                }
                s->Phone.Data.RequestMsg = &d->Msg;
                s->Phone.Data.DispatchError = s->Phone.Functions->DispatchMessage(s);
                free(d->Msg.Buffer);
                d->Msg.Buffer = NULL;
                d->Msg.Length = 0;
                d->MsgRXState = RX_Sync;
                return ERR_NONE;
        }
        return ERR_NONE;
}

static GSM_Error GNAPBUS_Initialise(GSM_StateMachine *s)
{
        GSM_Protocol_GNAPBUSData *d = &s->Protocol.Data.GNAPBUS;

        d->Msg.BufferUsed       = 0;
        d->Msg.Buffer           = NULL;
        d->Msg.Length           = 0;

        d->MsgRXState           = RX_Sync;

        return ERR_NONE;
}

static GSM_Error GNAPBUS_Terminate(GSM_StateMachine *s)
{
        free(s->Protocol.Data.GNAPBUS.Msg.Buffer);
        s->Protocol.Data.GNAPBUS.Msg.Buffer=NULL;
        return ERR_NONE;
}

GSM_Protocol_Functions GNAPBUSProtocol = {
        GNAPBUS_WriteMessage,
        GNAPBUS_StateMachine,
        GNAPBUS_Initialise,
        GNAPBUS_Terminate
};

#endif

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