etherdrv.c

这个是LINUX下的GDB调度工具的源码

#endif
}

/*
 *  Function: read_packet
 *   Purpose: read a packet, and pass it back to higher levels
 *
 *    Params:
 *      In/Out: packet  Holder for the read packet
 *
 *   Returns:  1 - Packet is complete
 *             0 - No complete packet read
 *
 * Post-conditions: Will call panic() if something goes wrong with the OS
 */
static int read_packet(struct data_packet *const packet)
{
    struct sockaddr_in from;
    int nbytes, fromlen = sizeof(from);
    DevChanID devchan;

    /*
     * try to get the packet
     */
    if ((nbytes = recvfrom(sock, (char *)(packet->data), packet->buf_len, 0,
                           (struct sockaddr *)&from, &fromlen)) < 0)
    {
#ifdef COMPILING_ON_WINDOWS
        if (nbytes == SOCKET_ERROR && WSAGetLastError() != WSAEWOULDBLOCK)
            MessageBox(GetFocus(), "Error receiving packet\n", "Angel", MB_OK | MB_ICONSTOP);
#else
        if (errno != EWOULDBLOCK)
        {
# ifdef DEBUG
            perror("recv");
# endif
            panic("ethernet recv failure");
        }
#endif
        return 0;
    }

#ifdef COMPILING_ON_WINDOWS
    if (pfnProgressCallback != NULL && nbytes != SOCKET_ERROR)
    {
        progressInfo.nRead += nbytes;
        (*pfnProgressCallback)(&progressInfo);
    }
#endif

    /*
     * work out where the packet was from
     */
    if (from.sin_addr.s_addr != remote.sin_addr.s_addr)
    {
        /*
         * not from our target - ignore it
         */
#ifdef DEBUG
        printf("read_packet: ignoring packet from %s\n",
               inet_ntoa(from.sin_addr));
#endif

        return 0;
    }
    else if (ntohs(from.sin_port) == ports[DBUG_INDEX])
        devchan = DC_DBUG;
    else if (ntohs(from.sin_port) == ports[APPL_INDEX])
        devchan = DC_APPL;
    else
    {
        /*
         * unknown port number - ignore it
         */
#ifdef DEBUG
        printf("read_packet: ignore packet from port %hd\n",
               htons(from.sin_port));
#endif

        return 0;
    }

#if defined(DEBUG) && !defined(DO_TRACE)
    printf("EthernetRead: %d bytes from %s channel\n",
           nbytes, (devchan == DC_DBUG) ? "DBUG" : "APPL");
#endif

#ifdef DO_TRACE
    printf("[%d on %d]\n", nbytes, devchan);
    {
        int i = 0;
        unsigned char *cptr = packet->data;

        while (i < nbytes)
        {
            printf("<%02X ", *(cptr++));

            if (!(++i % 16))
                printf("\n");
        }

        if (i % 16)
            printf("\n");
    }
#endif

    /*
     * OK - fill in the details
     */
    packet->type = devchan;
    packet->len = nbytes;
    return 1;
}

/**********************************************************************/

/*
 *  Function: Ethernet_Open
 *   Purpose: Open the Ethernet device.  See the documentation for
 *              DeviceOpen in drivers.h
 *
 * Post-conditions: Will have updated struct sockaddr_in remote (*ia)
 *                      with the address of the remote target.
 */
static int EthernetOpen(const char *name, const char *arg)
{
#ifdef COMPILING_ON_WINDOWS
    WORD wVersionRequested;
    WSADATA wsaData;
#endif
    /*
     * name is passed as e=<blah>, so skip 1st two characters
     */
    const char *etheraddr = name + 2;

#ifdef DEBUG
    printf("EthernetOpen: name `%s'\n", name);
#endif

    /* Check that the name is a valid one */
    if (EthernetMatch(name, arg) != 0)
        return -1;

#ifdef COMPILING_ON_WINDOWS
    wVersionRequested = MAKEWORD(1, 1);
    if (WSAStartup(wVersionRequested, &wsaData) != 0)
        /*
         * Couldn't find a useable winsock.dll.
         */
        return -1;

    if ( LOBYTE( wsaData.wVersion ) != 1 || HIBYTE( wsaData.wVersion ) != 1 )
    {
        WSACleanup();

        /*
         * Couldn't find a winsock.dll with supported version.
         */
        return -1;
    }
#endif

    memset((char *)ia, 0, sizeof(*ia));
    if (set_address(etheraddr, ia) < 0)
    {
#ifdef COMPILING_ON_WINDOWS
        /*
         * SJ - I'm not sure that this is the correct way to handle this
         * as Fail calls remote_disable and exits, while panic just exits.
         * However at the time of writing remote_disable does nothing!
         */
 /*     Panic("EthernetOpen: bad name `%s'\n", etheraddr); */
#else
        Fail("EthernetOpen: bad name `%s'\n", etheraddr);
#endif
        return -1;
    }

    if ((sock = open_socket()) < 0)
        return -1;

    /*
     * fetch the port numbers assigned by the remote target
     * to its Debug and Application sockets
     */
    fetch_ports();

    return 0;
}

static int EthernetMatch(const char *name, const char *arg)
{
    /* IGNORE arg */
    if (0)
        arg = arg;

    if (name == NULL)
        return -1;

    if (tolower(name[0]) != 'e' || name[1] != '=')
        return -1;

    return 0;
}

static void EthernetClose(void)
{
    if (sock >= 0)
    {
        closesocket(sock);
        sock = -1;
    }

#ifdef COMPILING_ON_WINDOWS
    WSACleanup();
#endif
}

static int EthernetRead(DriverCall *dc, bool block)
{
    fd_set fdset;
    struct timeval tv;
    int err;

    FD_ZERO(&fdset);
    FD_SET(sock, &fdset);

#ifdef COMPILING_ON_WINDOWS
    UNUSED(block);
    tv.tv_sec = tv.tv_usec = 0;
#else
    tv.tv_sec = 0;
    tv.tv_usec = (block ? 10000 : 0);
#endif

    err = select(sock + 1, &fdset, NULL, NULL, &tv);

    if (err < 0) {
      if (errno == EINTR) {
        return 0;
      }
      panic("ethernet select failure (errno=%i)",errno);
      return 0;
    }

    if (FD_ISSET(sock, &fdset))
      return read_packet(&dc->dc_packet);
    else
      return 0;
}

static int EthernetWrite(DriverCall *dc)
{
    int nbytes;
    struct data_packet *packet = &dc->dc_packet;

    if (packet->type == DC_DBUG)
        ia->sin_port = htons(ports[DBUG_INDEX]);
    else if (packet->type == DC_APPL)
        ia->sin_port = htons(ports[APPL_INDEX]);
    else
    {
        panic("EthernetWrite: unknown devchan");
        return 0;
    }

#if defined(DEBUG) && !defined(DO_TRACE)
    printf("EthernetWrite: %d bytes to %s channel\n",
           packet->len, (packet->type == DC_DBUG) ? "DBUG" : "APPL");
#endif

#ifdef DO_TRACE
    printf("[%d on %d]\n", packet->len, packet->type);
    {
        int i = 0;
        unsigned char *cptr = packet->data;

        while (i < packet->len)
        {
            printf(">%02X ", *(cptr++));

            if (!(++i % 16))
                printf("\n");
        }

        if (i % 16)
            printf("\n");
    }
#endif

    if ((nbytes = sendto(sock, (char *)(packet->data), packet->len, 0,
                         (struct sockaddr *)ia, sizeof(*ia))) != packet->len)
    {
#ifdef COMPILING_ON_WINDOWS
        if (nbytes == SOCKET_ERROR && WSAGetLastError() != WSAEWOULDBLOCK)
#else
        if (nbytes < 0 && errno != EWOULDBLOCK)
#endif
        {
#ifdef DEBUG
            perror("sendto");
#endif

#ifdef COMPILING_ON_WINDOWS
            panic("ethernet send failure\n");
#else
            /* might not work for Windows */
            panic("ethernet send failure [%s]\n",
#ifdef STDC_HEADERS
		  strerror(errno));
#else
                  errno < sys_nerr ? sys_errlist[errno] : "unknown errno");
#endif /* STDC_HEADERS */
#endif
        }
#ifdef DEBUG
        else if (nbytes >= 0)
            fprintf(stderr, "ethernet send: asked for %d, sent %d\n", packet->len, nbytes);
#endif
        return 0;
    }

#ifdef COMPILING_ON_WINDOWS
    if (pfnProgressCallback != NULL && nbytes != SOCKET_ERROR)
    {
        progressInfo.nWritten += nbytes;
        (*pfnProgressCallback)(&progressInfo);
    }
#endif

    return 1;
}

static int EthernetIoctl(const int opcode, void *args)
{
#ifdef DEBUG
    printf( "EthernetIoctl: op %d arg %x\n", opcode, args );
#endif

    /*
     * IGNORE(opcode)
     */
    if (0)
    {
        int dummy = opcode;
        UNUSED(dummy);
    }
    UNUSED(args);

    switch ( opcode )
    {
        case DC_RESYNC:
        {
#ifdef DEBUG
            printf( "EthernetIoctl: resync\n" );
#endif
            fetch_ports();
            return 0;
        }

        default:
        {
            return -1;
        }
    }
}

/* EOF etherdrv.c */