connection.c

远程桌面连接工具

    int whichbyte = 1;
#ifndef AMOEBA
    struct timeval waittime;
    fd_set mask;

    /* if these seems like a lot of trouble to go to, it probably is */
    waittime.tv_sec = BOTIMEOUT / MILLI_PER_SECOND;
    waittime.tv_usec = (BOTIMEOUT % MILLI_PER_SECOND) *
		       (1000000 / MILLI_PER_SECOND);
    FD_ZERO(&mask);
    FD_SET(fd, &mask);
    (void)Select(fd + 1, &mask, NULL, NULL, &waittime);
#endif
    /* try to read the byte-order of the connection */
    (void)_XSERVTransRead(trans_conn, &byteOrder, 1);
    if ((byteOrder == 'l') || (byteOrder == 'B'))
    {
	csp.success = xFalse;
	csp.lengthReason = sizeof(NOROOM) - 1;
	csp.length = (sizeof(NOROOM) + 2) >> 2;
	csp.majorVersion = X_PROTOCOL;
	csp.minorVersion = X_PROTOCOL_REVISION;
	if (((*(char *) &whichbyte) && (byteOrder == 'B')) ||
	    (!(*(char *) &whichbyte) && (byteOrder == 'l')))
	{
	    swaps(&csp.majorVersion, whichbyte);
	    swaps(&csp.minorVersion, whichbyte);
	    swaps(&csp.length, whichbyte);
	}
	iov[0].iov_len = sz_xConnSetupPrefix;
	iov[0].iov_base = (char *) &csp;
	iov[1].iov_len = csp.lengthReason;
	iov[1].iov_base = NOROOM;
	iov[2].iov_len = (4 - (csp.lengthReason & 3)) & 3;
	iov[2].iov_base = pad;
	(void)_XSERVTransWritev(trans_conn, iov, 3);
    }
}

/************
 *   CloseDownFileDescriptor:
 *     Remove this file descriptor and it's I/O buffers, etc.
 ************/

#ifdef LBX
void
CloseDownFileDescriptor(client)
    ClientPtr	client;
#else
static void
CloseDownFileDescriptor(oc)
    register OsCommPtr oc;
#endif
{
#ifdef LBX
    register OsCommPtr oc = (OsCommPtr) client->osPrivate;
#endif
    int connection = oc->fd;

    if (oc->trans_conn) {
	_XSERVTransDisconnect(oc->trans_conn);
	_XSERVTransClose(oc->trans_conn);
    }
#ifdef LBX
    ConnectionTranslation[connection] = 0;
#else
    FreeOsBuffers(oc);
#endif
    FD_CLR(connection, &AllSockets);
    FD_CLR(connection, &AllClients);
    FD_CLR(connection, &ClientsWithInput);
    FD_CLR(connection, &GrabImperviousClients);
    if (GrabInProgress)
    {
	FD_CLR(connection, &SavedAllSockets);
	FD_CLR(connection, &SavedAllClients);
	FD_CLR(connection, &SavedClientsWithInput);
    }
    FD_CLR(connection, &ClientsWriteBlocked);
    if (!XFD_ANYSET(&ClientsWriteBlocked))
    	AnyClientsWriteBlocked = FALSE;
    FD_CLR(connection, &OutputPending);
#ifndef LBX
    xfree(oc);
#endif
}

/*****************
 * CheckConections
 *    Some connection has died, go find which one and shut it down 
 *    The file descriptor has been closed, but is still in AllClients.
 *    If would truly be wonderful if select() would put the bogus
 *    file descriptors in the exception mask, but nooooo.  So we have
 *    to check each and every socket individually.
 *****************/

void
CheckConnections()
{
#ifndef WIN32
    fd_mask		mask;
#endif
    fd_set		tmask; 
    register int	curclient, curoff;
    int			i;
    struct timeval	notime;
    int r;
#ifdef WIN32
    fd_set savedAllClients;
#endif

#ifndef AMOEBA
    notime.tv_sec = 0;
    notime.tv_usec = 0;

#ifndef WIN32
    for (i=0; i<howmany(XFD_SETSIZE, NFDBITS); i++)
    {
	mask = AllClients.fds_bits[i];
        while (mask)
    	{
	    curoff = ffsl(mask) - 1;
 	    curclient = curoff + (8 * sizeof(fd_mask) * i);
            FD_ZERO(&tmask);
            FD_SET(curclient, &tmask);
            r = Select (curclient + 1, &tmask, NULL, NULL, &notime);
            
            if (r < 0)
		CloseDownClient(clients[ConnectionTranslation[curclient]]);
	    mask &= ~(((fd_mask)1) << curoff);
	}
    }	
#else
    XFD_COPYSET(&AllClients, &savedAllClients);
    for (i = 0; i < XFD_SETCOUNT(&savedAllClients); i++)
    {
	curclient = XFD_FD(&savedAllClients, i);
	FD_ZERO(&tmask);
	FD_SET(curclient, &tmask);
	r = Select (curclient + 1, &tmask, NULL, NULL, &notime);
	if (r < 0)
	    CloseDownClient(clients[ConnectionTranslation[curclient]]);
    }	
#endif
#endif
}


/*****************
 * CloseDownConnection
 *    Delete client from AllClients and free resources 
 *****************/

void
CloseDownConnection(client)
    ClientPtr client;
{
    OsCommPtr oc = (OsCommPtr)client->osPrivate;

    if (oc->output && oc->output->count)
	FlushClient(client, oc, (char *)NULL, 0);
#ifdef XDMCP
    XdmcpCloseDisplay(oc->fd);
#endif
#ifndef LBX
    CloseDownFileDescriptor(oc);
#else
    (*oc->Close) (client);
    FreeOsBuffers(oc);
    xfree(oc);
#endif
    client->osPrivate = (pointer)NULL;
    if (auditTrailLevel > 1)
	AuditF("client %d disconnected\n", client->index);
}


AddEnabledDevice(fd)
    int fd;
{
    FD_SET(fd, &EnabledDevices);
    FD_SET(fd, &AllSockets);
}


RemoveEnabledDevice(fd)
    int fd;
{
    FD_CLR(fd, &EnabledDevices);
    FD_CLR(fd, &AllSockets);
}

/*****************
 * OnlyListenToOneClient:
 *    Only accept requests from  one client.  Continue to handle new
 *    connections, but don't take any protocol requests from the new
 *    ones.  Note that if GrabInProgress is set, EstablishNewConnections
 *    needs to put new clients into SavedAllSockets and SavedAllClients.
 *    Note also that there is no timeout for this in the protocol.
 *    This routine is "undone" by ListenToAllClients()
 *****************/

OnlyListenToOneClient(client)
    ClientPtr client;
{
    OsCommPtr oc = (OsCommPtr)client->osPrivate;
    int connection = oc->fd;

    if (! GrabInProgress)
    {
	XFD_COPYSET(&ClientsWithInput, &SavedClientsWithInput);
	XFD_ANDSET(&ClientsWithInput,
		       &ClientsWithInput, &GrabImperviousClients);
	if (FD_ISSET(connection, &SavedClientsWithInput))
	{
	    FD_CLR(connection, &SavedClientsWithInput);
	    FD_SET(connection, &ClientsWithInput);
	}
	XFD_UNSET(&SavedClientsWithInput, &GrabImperviousClients);
	XFD_COPYSET(&AllSockets, &SavedAllSockets);
	XFD_COPYSET(&AllClients, &SavedAllClients);
	XFD_UNSET(&AllSockets, &AllClients);
	XFD_ANDSET(&AllClients, &AllClients, &GrabImperviousClients);
	FD_SET(connection, &AllClients);
	XFD_ORSET(&AllSockets, &AllSockets, &AllClients);
	GrabInProgress = client->index;
    }
}

/****************
 * ListenToAllClients:
 *    Undoes OnlyListentToOneClient()
 ****************/

ListenToAllClients()
{
    if (GrabInProgress)
    {
	XFD_ORSET(&AllSockets, &AllSockets, &SavedAllSockets);
	XFD_ORSET(&AllClients, &AllClients, &SavedAllClients);
	XFD_ORSET(&ClientsWithInput, &ClientsWithInput, &SavedClientsWithInput);
	GrabInProgress = 0;
    }	
}

/****************
 * IgnoreClient
 *    Removes one client from input masks.
 *    Must have cooresponding call to AttendClient.
 ****************/

IgnoreClient (client)
    ClientPtr	client;
{
    OsCommPtr oc = (OsCommPtr)client->osPrivate;
    int connection = oc->fd;
#ifdef LBX
    LbxClientPtr lbxClient = LbxClient(client);
#endif

    isItTimeToYield = TRUE;
#ifdef LBX
    if (lbxClient) {
	lbxClient->ignored = TRUE;
	return;
    }
#endif
    if (!GrabInProgress || FD_ISSET(connection, &AllClients))
    {
    	if (FD_ISSET (connection, &ClientsWithInput))
	    FD_SET(connection, &IgnoredClientsWithInput);
    	else
	    FD_CLR(connection, &IgnoredClientsWithInput);
    	FD_CLR(connection, &ClientsWithInput);
    	FD_CLR(connection, &AllSockets);
    	FD_CLR(connection, &AllClients);
	FD_CLR(connection, &LastSelectMask);
    }
    else
    {
    	if (FD_ISSET (connection, &SavedClientsWithInput))
	    FD_SET(connection, &IgnoredClientsWithInput);
    	else
	    FD_CLR(connection, &IgnoredClientsWithInput);
	FD_CLR(connection, &SavedClientsWithInput);
	FD_CLR(connection, &SavedAllSockets);
	FD_CLR(connection, &SavedAllClients);
    }
}

/****************
 * AttendClient
 *    Adds one client back into the input masks.
 ****************/

AttendClient (client)
    ClientPtr	client;
{
    OsCommPtr oc = (OsCommPtr)client->osPrivate;
    int connection = oc->fd;
#ifdef LBX
    LbxClientPtr lbxClient = LbxClient(client);

    if (lbxClient) {
	lbxClient->ignored = FALSE;
	return;
    }
#endif
    if (!GrabInProgress || GrabInProgress == client->index ||
	FD_ISSET(connection, &GrabImperviousClients))
    {
    	FD_SET(connection, &AllClients);
    	FD_SET(connection, &AllSockets);
	FD_SET(connection, &LastSelectMask);
    	if (FD_ISSET (connection, &IgnoredClientsWithInput))
	    FD_SET(connection, &ClientsWithInput);
    }
    else
    {
	FD_SET(connection, &SavedAllClients);
	FD_SET(connection, &SavedAllSockets);
	if (FD_ISSET(connection, &IgnoredClientsWithInput))
	    FD_SET(connection, &SavedClientsWithInput);
    }
}

/* make client impervious to grabs; assume only executing client calls this */

MakeClientGrabImpervious(client)
    ClientPtr client;
{
    OsCommPtr oc = (OsCommPtr)client->osPrivate;
    int connection = oc->fd;

    FD_SET(connection, &GrabImperviousClients);

    if (ServerGrabCallback)
    {
	ServerGrabInfoRec grabinfo;
	grabinfo.client = client;
	grabinfo.grabstate  = CLIENT_IMPERVIOUS;
	CallCallbacks(&ServerGrabCallback, &grabinfo);
    }
}

/* make client pervious to grabs; assume only executing client calls this */

MakeClientGrabPervious(client)
    ClientPtr client;
{
    OsCommPtr oc = (OsCommPtr)client->osPrivate;
    int connection = oc->fd;

    FD_CLR(connection, &GrabImperviousClients);
    if (GrabInProgress && (GrabInProgress != client->index))
    {
	if (FD_ISSET(connection, &ClientsWithInput))
	{
	    FD_SET(connection, &SavedClientsWithInput);
	    FD_CLR(connection, &ClientsWithInput);
	}
	FD_CLR(connection, &AllSockets);
	FD_CLR(connection, &AllClients);
	isItTimeToYield = TRUE;
    }

    if (ServerGrabCallback)
    {
	ServerGrabInfoRec grabinfo;
	grabinfo.client = client;
	grabinfo.grabstate  = CLIENT_PERVIOUS;
	CallCallbacks(&ServerGrabCallback, &grabinfo);
    }
}

#ifdef AIXV3

static fd_set pendingActiveClients;
static BOOL reallyGrabbed;

/****************
* DontListenToAnybody:
*   Don't listen to requests from any clients. Continue to handle new
*   connections, but don't take any protocol requests from anybody.
*   We have to take care if there is already a grab in progress, though.
*   Undone by PayAttentionToClientsAgain. We also have to be careful
*   not to accept any more input from the currently dispatched client.
*   we do this be telling dispatch it is time to yield.

*   We call this when the server loses access to the glass
*   (user hot-keys away).  This looks like a grab by the 
*   server itself, but gets a little tricky if there is already
*   a grab in progress.
******************/

void
DontListenToAnybody()
{
    if (!GrabInProgress)
    {
	XFD_COPYSET(&ClientsWithInput, &SavedClientsWithInput);
	XFD_COPYSET(&AllSockets, &SavedAllSockets);
	XFD_COPYSET(&AllClients, &SavedAllClients);
	GrabInProgress = TRUE;
	reallyGrabbed = FALSE;
    }
    else
    {
	XFD_COPYSET(&AllClients, &pendingActiveClients);
	reallyGrabbed = TRUE;
    }
    FD_ZERO(&ClientsWithInput);
    XFD_UNSET(&AllSockets, &AllClients);
    FD_ZERO(&AllClients);
    isItTimeToYield = TRUE;
}

void
PayAttentionToClientsAgain()
{
    if (reallyGrabbed)
    {
	XFD_ORSET(&AllSockets, &AllSockets, &pendingActiveClients);
	XFD_ORSET(&AllClients, &AllClients, &pendingActiveClients);
    }
    else
    {
	ListenToAllClients();
    }
    reallyGrabbed = FALSE;
}

#endif