xdmcp.c

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void
XdmcpRegisterAuthorizations ()
{
    XdmcpDisposeARRAYofARRAY8 (&AuthorizationNames);
    RegisterAuthorizations ();
}

void
XdmcpRegisterAuthorization (name, namelen)
    char    *name;
    int	    namelen;
{
    ARRAY8  authName;
    int	    i;

    authName.data = (CARD8 *) xalloc (namelen * sizeof (CARD8));
    if (!authName.data)
	return;
    if (!XdmcpReallocARRAYofARRAY8 (&AuthorizationNames, AuthorizationNames.length +1))
    {
	xfree (authName.data);
	return;
    }
    for (i = 0; i < namelen; i++)
	authName.data[i] = (CARD8) name[i];
    authName.length = namelen;
    AuthorizationNames.data[AuthorizationNames.length-1] = authName;
}

/*
 * Register the DisplayClass string
 */

ARRAY8	DisplayClass;

void
XdmcpRegisterDisplayClass (name, length)
    char    *name;
    int	    length;
{
    int	    i;

    XdmcpDisposeARRAY8 (&DisplayClass);
    if (!XdmcpAllocARRAY8 (&DisplayClass, length))
	return;
    for (i = 0; i < length; i++)
	DisplayClass.data[i] = (CARD8) name[i];
}

/*
 * Register the Manufacturer display ID
 */

ARRAY8 ManufacturerDisplayID;

void
XdmcpRegisterManufacturerDisplayID (name, length)
    char    *name;
    int	    length;
{
    int	    i;

    XdmcpDisposeARRAY8 (&ManufacturerDisplayID);
    if (!XdmcpAllocARRAY8 (&ManufacturerDisplayID, length))
	return;
    for (i = 0; i < length; i++)
	ManufacturerDisplayID.data[i] = (CARD8) name[i];
}

/* 
 * initialize XDMCP; create the socket, compute the display
 * number, set up the state machine
 */

void 
XdmcpInit()
{
    state = XDM_INIT_STATE;
#ifdef HASXDMAUTH
    if (xdmAuthCookie)
	XdmAuthenticationInit (xdmAuthCookie, strlen (xdmAuthCookie));
#endif
    if (state != XDM_OFF)
    {
	XdmcpRegisterAuthorizations();
	XdmcpRegisterDisplayClass (defaultDisplayClass, strlen (defaultDisplayClass));
	AccessUsingXdmcp();
	RegisterBlockAndWakeupHandlers (XdmcpBlockHandler, XdmcpWakeupHandler,
				        (pointer) 0);
    	timeOutRtx = 0;
    	DisplayNumber = (CARD16) atoi(display);
    	get_xdmcp_sock();
    	send_packet();
    }
}

void
XdmcpReset ()
{
    state = XDM_INIT_STATE;
    if (state != XDM_OFF)
    {
	RegisterBlockAndWakeupHandlers (XdmcpBlockHandler, XdmcpWakeupHandler,
				        (pointer) 0);
    	timeOutRtx = 0;
    	send_packet();
    }
}

/*
 * Called whenever a new connection is created; notices the
 * first connection and saves it to terminate the session
 * when it is closed
 */

void
XdmcpOpenDisplay(sock)
    int	sock;
{
    if (state != XDM_AWAIT_MANAGE_RESPONSE)
	return;
    state = XDM_RUN_SESSION;
    sessionSocket = sock;
}

void 
XdmcpCloseDisplay(sock)
    int	sock;
{
    if ((state != XDM_RUN_SESSION && state != XDM_AWAIT_ALIVE_RESPONSE)
	|| sessionSocket != sock)
	    return;
    state = XDM_INIT_STATE;
    if (OneSession)
	dispatchException |= DE_TERMINATE;
    else
	dispatchException |= DE_RESET;
    isItTimeToYield = TRUE;
}

/*
 * called before going to sleep, this routine
 * may modify the timeout value about to be sent
 * to select; in this way XDMCP can do appropriate things
 * dynamically while starting up
 */

/*ARGSUSED*/
static void
XdmcpBlockHandler(data, wt, pReadmask)
    pointer	    data;   /* unused */
    struct timeval  **wt;
    pointer	    pReadmask;
{
    fd_set *LastSelectMask = (fd_set*)pReadmask;
    CARD32 millisToGo, wtMillis;
    static struct timeval waittime;

    if (state == XDM_OFF)
	return;
    FD_SET(xdmcpSocket, LastSelectMask);
    if (timeOutTime == 0)
	return;
    millisToGo = GetTimeInMillis();
    if (millisToGo < timeOutTime)
	millisToGo = timeOutTime - millisToGo;
    else
	millisToGo = 0;
    if (*wt == NULL)
    {
	waittime.tv_sec = (millisToGo) / 1000;
	waittime.tv_usec = 1000 * (millisToGo % 1000);
	*wt = &waittime;
    }
    else
    {
	wtMillis = (*wt)->tv_sec * 1000 + (*wt)->tv_usec / 1000;
	if (millisToGo < wtMillis)
 	{
	    (*wt)->tv_sec = (millisToGo) / 1000;
	    (*wt)->tv_usec = 1000 * (millisToGo % 1000);
	}
    }
}

/*
 * called after select returns; this routine will
 * recognise when XDMCP packets await and
 * process them appropriately
 */

/*ARGSUSED*/
static void
XdmcpWakeupHandler(data, i, pReadmask)
    pointer data;   /* unused */
    int	    i;
    pointer pReadmask;
{
    fd_set* LastSelectMask = (fd_set*)pReadmask;
    fd_set   devicesReadable;

    if (state == XDM_OFF)
	return;
    if (i > 0)
    {
	if (FD_ISSET(xdmcpSocket, LastSelectMask))
	{
	    receive_packet();
	    FD_CLR(xdmcpSocket, LastSelectMask);
	} 
	XFD_ANDSET(&devicesReadable, LastSelectMask, &EnabledDevices);
	if (XFD_ANYSET(&devicesReadable))
	{
	    if (state == XDM_AWAIT_USER_INPUT)
		restart();
	    else if (state == XDM_RUN_SESSION)
		keepaliveDormancy = defaultKeepaliveDormancy;
	}
	if (XFD_ANYSET(&AllClients) && state == XDM_RUN_SESSION)
	    timeOutTime = GetTimeInMillis() +  keepaliveDormancy * 1000;
    }
    else if (timeOutTime && GetTimeInMillis() >= timeOutTime)
    {
    	if (state == XDM_RUN_SESSION)
    	{
	    state = XDM_KEEPALIVE;
	    send_packet();
    	}
    	else
	    timeout();
    }
}

/*
 * This routine should be called from the routine that drives the
 * user's host menu when the user selects a host
 */

XdmcpSelectHost(host_sockaddr, host_len, AuthenticationName)
    struct sockaddr_in	*host_sockaddr;
    int			host_len;
    ARRAY8Ptr		AuthenticationName;
{
    state = XDM_START_CONNECTION;
    memmove(&req_sockaddr, host_sockaddr, host_len);
    req_socklen = host_len;
    XdmcpSetAuthentication (AuthenticationName);
    send_packet();
}

/*
 * !!! this routine should be replaced by a routine that adds
 * the host to the user's host menu. the current version just
 * selects the first host to respond with willing message.
 */

/*ARGSUSED*/
XdmcpAddHost(from, fromlen, AuthenticationName, hostname, status)
    struct sockaddr_in  *from;
    ARRAY8Ptr		AuthenticationName, hostname, status;
{
    XdmcpSelectHost(from, fromlen, AuthenticationName);
}

/*
 * A message is queued on the socket; read it and
 * do the appropriate thing
 */

ARRAY8	UnwillingMessage = { (CARD8) 14, (CARD8 *) "Host unwilling" };

static void
receive_packet()
{
    struct sockaddr_in from;
    int fromlen = sizeof(struct sockaddr_in);
    XdmcpHeader	header;

    /* read message off socket */
    if (!XdmcpFill (xdmcpSocket, &buffer, (struct sockaddr *) &from, &fromlen))
	return;

    /* reset retransmission backoff */
    timeOutRtx = 0;

    if (!XdmcpReadHeader (&buffer, &header))
	return;

    if (header.version != XDM_PROTOCOL_VERSION)
	return;

    switch (header.opcode) {
    case WILLING:
	recv_willing_msg(&from, fromlen, header.length);
	break;
    case UNWILLING:
	XdmcpFatal("Manager unwilling", &UnwillingMessage);
	break;
    case ACCEPT:
	recv_accept_msg(header.length);
	break;
    case DECLINE:
	recv_decline_msg(header.length);
	break;
    case REFUSE:
	recv_refuse_msg(header.length);
	break;
    case FAILED:
	recv_failed_msg(header.length);
	break;
    case ALIVE:
	recv_alive_msg(header.length);
	break;
    }
}

/*
 * send the appropriate message given the current state
 */

static
send_packet()
{
    int rtx;
    switch (state) {
    case XDM_QUERY:
    case XDM_BROADCAST:
    case XDM_INDIRECT:
	send_query_msg();
	break;
    case XDM_START_CONNECTION:
	send_request_msg();
	break;
    case XDM_MANAGE:
	send_manage_msg();
	break;
    case XDM_KEEPALIVE:
	send_keepalive_msg();
	break;
    }
    rtx = (XDM_MIN_RTX << timeOutRtx);
    if (rtx > XDM_MAX_RTX)
	rtx = XDM_MAX_RTX;
    timeOutTime = GetTimeInMillis() + rtx * 1000;
}

/*
 * The session is declared dead for some reason; too many
 * timeouts, or Keepalive failure.
 */

XdmcpDeadSession (reason)
    char *reason;
{
    ErrorF ("XDM: %s, declaring session dead\n", reason);
    state = XDM_INIT_STATE;
    isItTimeToYield = TRUE;
    dispatchException |= DE_RESET;
    timeOutTime = 0;
    timeOutRtx = 0;
    send_packet();
}

/*
 * Timeout waiting for an XDMCP response.
 */

static void
timeout()
{
    timeOutRtx++;
    if (state == XDM_AWAIT_ALIVE_RESPONSE && timeOutRtx >= XDM_KA_RTX_LIMIT )
    {
	XdmcpDeadSession ("too many keepalive retransmissions");
	return;
    }
    else if (timeOutRtx >= XDM_RTX_LIMIT)
    {
	ErrorF("XDM: too many retransmissions\n");
	state = XDM_AWAIT_USER_INPUT;
	timeOutTime = 0;
	timeOutRtx = 0;
	return;
    }

    switch (state) {
    case XDM_COLLECT_QUERY:
	state = XDM_QUERY;
	break;
    case XDM_COLLECT_BROADCAST_QUERY:
	state = XDM_BROADCAST;
	break;
    case XDM_COLLECT_INDIRECT_QUERY:
	state = XDM_INDIRECT;
	break;
    case XDM_AWAIT_REQUEST_RESPONSE:
	state = XDM_START_CONNECTION;
	break;
    case XDM_AWAIT_MANAGE_RESPONSE:
	state = XDM_MANAGE;
	break;
    case XDM_AWAIT_ALIVE_RESPONSE:
	state = XDM_KEEPALIVE;
	break;
    }
    send_packet();
}

static
restart()
{
    state = XDM_INIT_STATE;
    timeOutRtx = 0;
    send_packet();
}

XdmcpCheckAuthentication (Name, Data, packet_type)
    ARRAY8Ptr	Name, Data;
    int	packet_type;
{
    return (XdmcpARRAY8Equal (Name, AuthenticationName) &&
	    (AuthenticationName->length == 0 ||
	     (*AuthenticationFuncs->Validator) (AuthenticationData, Data, packet_type)));
}

XdmcpAddAuthorization (name, data)
    ARRAY8Ptr	name, data;
{
    Bool    (*AddAuth)(), AddAuthorization();

    if (AuthenticationFuncs && AuthenticationFuncs->AddAuth)
	AddAuth = AuthenticationFuncs->AddAuth;
    else
	AddAuth = AddAuthorization;
    return (*AddAuth) ((unsigned short)name->length,
		       (char *)name->data,
		       (unsigned short)data->length,
		       (char *)data->data);
}

/*
 * from here to the end of this file are routines private
 * to the state machine.
 */

static void
get_xdmcp_sock()
{
#ifdef STREAMSCONN
    struct netconfig *nconf;

    if ((xdmcpSocket = t_open("/dev/udp", O_RDWR, 0)) < 0) {
	XdmcpWarning("t_open() of /dev/udp failed");
	return;
    }

    if( t_bind(xdmcpSocket,NULL,NULL) < 0 ) {
	XdmcpWarning("UDP socket creation failed");
	t_error("t_bind(xdmcpSocket) failed" );
	t_close(xdmcpSocket);
	return;
    }

    /*
     * This part of the code looks contrived. It will actually fit in nicely
     * when the CLTS part of Xtrans is implemented.
     */
 
    if( (nconf=getnetconfigent("udp")) == NULL ) {
	XdmcpWarning("UDP socket creation failed: getnetconfigent()");
	t_unbind(xdmcpSocket);
	t_close(xdmcpSocket);
	return;
    }
 
    if( netdir_options(nconf, ND_SET_BROADCAST, xdmcpSocket, NULL) ) {
	XdmcpWarning("UDP set broadcast option failed: netdir_options()");
	freenetconfigent(nconf);
	t_unbind(xdmcpSocket);
	t_close(xdmcpSocket);
	return;
    }
 
    freenetconfigent(nconf);
#else
#ifndef _MINIX
    int soopts = 1;

    if ((xdmcpSocket = socket(AF_INET, SOCK_DGRAM, 0)) < 0)