tclwinsock.c

linux系统下的音频通信

 *
 * Results:
 *	Returns a new SocketInfo, or NULL with an error in interp.
 *
 * Side effects:
 *	Adds a new socket to the socketList.
 *
 *----------------------------------------------------------------------
 */

static SocketInfo *
CreateSocket(interp, port, host, server, myaddr, myport, async)
    Tcl_Interp *interp;		/* For error reporting; can be NULL. */
    int port;			/* Port number to open. */
    char *host;			/* Name of host on which to open port. */
    int server;			/* 1 if socket should be a server socket,
				 * else 0 for a client socket. */
    char *myaddr;		/* Optional client-side address */
    int myport;			/* Optional client-side port */
    int async;			/* If nonzero, connect client socket
                                 * asynchronously. */
{
    u_long flag = 1;			/* Indicates nonblocking mode. */
    int asyncConnect = 0;		/* Will be 1 if async connect is
                                         * in progress. */
    struct sockaddr_in sockaddr;	/* Socket address */
    struct sockaddr_in mysockaddr;	/* Socket address for client */
    SOCKET sock;
    SocketInfo *infoPtr;		/* The returned value. */

    /*
     * Check that WinSock is initialized; do not call it if not, to
     * prevent system crashes. This can happen at exit time if the exit
     * handler for WinSock ran before other exit handlers that want to
     * use sockets.
     */
    
    if (winSock.hInstance == NULL) {
        return NULL;
    }
    
    if (! CreateSocketAddress(&sockaddr, host, port)) {
	goto error;
    }
    if ((myaddr != NULL || myport != 0) &&
	    ! CreateSocketAddress(&mysockaddr, myaddr, myport)) {
	goto error;
    }

    sock = (*winSock.socket)(AF_INET, SOCK_STREAM, 0);
    if (sock == INVALID_SOCKET) {
	goto error;
    }

    /*
     * Set kernel space buffering
     */

    TclSockMinimumBuffers(sock, TCP_BUFFER_SIZE);

    if (server) {
	/*
	 * Bind to the specified port.  Note that we must not call setsockopt
	 * with SO_REUSEADDR because Microsoft allows addresses to be reused
	 * even if they are still in use.
         *
         * Bind should not be affected by the socket having already been
         * set into nonblocking mode. If there is trouble, this is one place
         * to look for bugs.
	 */
    
	if ((*winSock.bind)(sock, (struct sockaddr *) &sockaddr,
		sizeof(sockaddr)) == SOCKET_ERROR) {
            goto error;
        }

        /*
         * Set the maximum number of pending connect requests to the
         * max value allowed on each platform (Win32 and Win32s may be
         * different, and there may be differences between TCP/IP stacks).
         */
        
	if ((*winSock.listen)(sock, SOMAXCONN) == SOCKET_ERROR) {
	    goto error;
	}

	/*
	 * Add this socket to the global list of sockets.
	 */

	infoPtr = NewSocketInfo(sock);

	/*
	 * Set up the select mask for connection request events.
	 */

	infoPtr->selectEvents = FD_ACCEPT;
	infoPtr->watchEvents |= FD_ACCEPT;

    } else {

        /*
         * Try to bind to a local port, if specified.
         */
        
	if (myaddr != NULL || myport != 0) { 
	    if ((*winSock.bind)(sock, (struct sockaddr *) &mysockaddr,
		    sizeof(struct sockaddr)) == SOCKET_ERROR) {
		goto error;
	    }
	}            
    
	/*
	 * Set the socket into nonblocking mode if the connect should be
	 * done in the background.
	 */
    
	if (async) {
	    if ((*winSock.ioctlsocket)(sock, FIONBIO, &flag) == SOCKET_ERROR) {
		goto error;
	    }
	}

	/*
	 * Attempt to connect to the remote socket.
	 */

	if ((*winSock.connect)(sock, (struct sockaddr *) &sockaddr,
		sizeof(sockaddr)) == SOCKET_ERROR) {
            TclWinConvertWSAError((*winSock.WSAGetLastError)());
	    if (Tcl_GetErrno() != EWOULDBLOCK) {
		goto error;
	    }

	    /*
	     * The connection is progressing in the background.
	     */

	    asyncConnect = 1;
        }

	/*
	 * Add this socket to the global list of sockets.
	 */

	infoPtr = NewSocketInfo(sock);

	/*
	 * Set up the select mask for read/write events.  If the connect
	 * attempt has not completed, include connect events.
	 */

	infoPtr->selectEvents = FD_READ | FD_WRITE | FD_CLOSE;
	if (asyncConnect) {
	    infoPtr->flags |= SOCKET_ASYNC_CONNECT;
	    infoPtr->selectEvents |= FD_CONNECT;
	}
    }

    /*
     * Register for interest in events in the select mask.  Note that this
     * automatically places the socket into non-blocking mode.
     */

    (*winSock.ioctlsocket)(sock, FIONBIO, &flag);
    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
	    SOCKET_MESSAGE, infoPtr->selectEvents);

    return infoPtr;

error:
    TclWinConvertWSAError((*winSock.WSAGetLastError)());
    if (interp != NULL) {
	Tcl_AppendResult(interp, "couldn't open socket: ",
		Tcl_PosixError(interp), (char *) NULL);
    }
    if (sock != INVALID_SOCKET) {
	(*winSock.closesocket)(sock);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * CreateSocketAddress --
 *
 *	This function initializes a sockaddr structure for a host and port.
 *
 * Results:
 *	1 if the host was valid, 0 if the host could not be converted to
 *	an IP address.
 *
 * Side effects:
 *	Fills in the *sockaddrPtr structure.
 *
 *----------------------------------------------------------------------
 */

static int
CreateSocketAddress(sockaddrPtr, host, port)
    struct sockaddr_in *sockaddrPtr;	/* Socket address */
    char *host;				/* Host.  NULL implies INADDR_ANY */
    int port;				/* Port number */
{
    struct hostent *hostent;		/* Host database entry */
    struct in_addr addr;		/* For 64/32 bit madness */

    /*
     * Check that WinSock is initialized; do not call it if not, to
     * prevent system crashes. This can happen at exit time if the exit
     * handler for WinSock ran before other exit handlers that want to
     * use sockets.
     */

    if (winSock.hInstance == NULL) {
        Tcl_SetErrno(EFAULT);
        return 0;
    }
    
    (void) memset((char *) sockaddrPtr, '\0', sizeof(struct sockaddr_in));
    sockaddrPtr->sin_family = AF_INET;
    sockaddrPtr->sin_port = (*winSock.htons)((short) (port & 0xFFFF));
    if (host == NULL) {
	addr.s_addr = INADDR_ANY;
    } else {
        addr.s_addr = (*winSock.inet_addr)(host);
        if (addr.s_addr == INADDR_NONE) {
            hostent = (*winSock.gethostbyname)(host);
            if (hostent != NULL) {
                memcpy((char *) &addr,
                        (char *) hostent->h_addr_list[0],
                        (size_t) hostent->h_length);
            } else {
#ifdef	EHOSTUNREACH
                Tcl_SetErrno(EHOSTUNREACH);
#else
#ifdef ENXIO
                Tcl_SetErrno(ENXIO);
#endif
#endif
		return 0;	/* Error. */
	    }
	}
    }

    /*
     * NOTE: On 64 bit machines the assignment below is rumored to not
     * do the right thing. Please report errors related to this if you
     * observe incorrect behavior on 64 bit machines such as DEC Alphas.
     * Should we modify this code to do an explicit memcpy?
     */

    sockaddrPtr->sin_addr.s_addr = addr.s_addr;
    return 1;	/* Success. */
}

/*
 *----------------------------------------------------------------------
 *
 * WaitForSocketEvent --
 *
 *	Waits until one of the specified events occurs on a socket.
 *
 * Results:
 *	Returns 1 on success or 0 on failure, with an error code in
 *	errorCodePtr.
 *
 * Side effects:
 *	Processes socket events off the system queue.
 *
 *----------------------------------------------------------------------
 */

static int
WaitForSocketEvent(infoPtr, events, errorCodePtr)
    SocketInfo *infoPtr;	/* Information about this socket. */
    int events;			/* Events to look for. */
    int *errorCodePtr;		/* Where to store errors? */
{
    MSG msg;
    int result = 1;
    int oldMode;

    /*
     * Be sure to disable event servicing so we are truly modal.
     */

    oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);
    
    /*
     * Reset WSAAsyncSelect so we have a fresh set of events pending.
     */

    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd, 0, 0);
    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
	    SOCKET_MESSAGE, infoPtr->selectEvents);

    while (1) {
	/*
	 * Process all outstanding messages on the socket window.
	 */

	while (PeekMessage(&msg, winSock.hwnd, 0, 0, PM_REMOVE)) {
	    DispatchMessage(&msg);
	}
	
	if (infoPtr->lastError) {
	    *errorCodePtr = infoPtr->lastError;
	    result = 0;
	    break;
	} else if (infoPtr->readyEvents & events) {
	    break;
	} else if (infoPtr->flags & SOCKET_ASYNC) {
	    *errorCodePtr = EWOULDBLOCK;
	    result = 0;
	    break;
	}

	/*
	 * Wait until something happens.
	 */

	WaitMessage();
    }
    
    (void) Tcl_SetServiceMode(oldMode);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_OpenTcpClient --
 *
 *	Opens a TCP client socket and creates a channel around it.
 *
 * Results:
 *	The channel or NULL if failed.  An error message is returned
 *	in the interpreter on failure.
 *
 * Side effects:
 *	Opens a client socket and creates a new channel.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_OpenTcpClient(interp, port, host, myaddr, myport, async)
    Tcl_Interp *interp;			/* For error reporting; can be NULL. */
    int port;				/* Port number to open. */
    char *host;				/* Host on which to open port. */
    char *myaddr;			/* Client-side address */
    int myport;				/* Client-side port */
    int async;				/* If nonzero, should connect
                                         * client socket asynchronously. */
{
    SocketInfo *infoPtr;
    char channelName[20];

    if (TclHasSockets(interp) != TCL_OK) {
	return NULL;
    }

    /*
     * Create a new client socket and wrap it in a channel.
     */

    infoPtr = CreateSocket(interp, port, host, 0, myaddr, myport, async);
    if (infoPtr == NULL) {
	return NULL;
    }

    sprintf(channelName, "sock%d", infoPtr->socket);

    infoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    (ClientData) infoPtr, (TCL_READABLE | TCL_WRITABLE));
    if (Tcl_SetChannelOption(interp, infoPtr->channel, "-translation",
	    "auto crlf") == TCL_ERROR) {
        Tcl_Close((Tcl_Interp *) NULL, infoPtr->channel);
        return (Tcl_Channel) NULL;
    }
    if (Tcl_SetChannelOption(NULL, infoPtr->channel, "-eofchar", "")
	    == TCL_ERROR) {
        Tcl_Close((Tcl_Interp *) NULL, infoPtr->channel);
        return (Tcl_Channel) NULL;
    }
    return infoPtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_MakeTcpClientChannel --
 *
 *	Creates a Tcl_Channel from an existing client TCP socket.
 *
 * Results:
 *	The Tcl_Channel wrapped around the preexisting TCP socket.
 *
 * Side effects:
 *	None.
 *
 * NOTE: Code contributed by Mark Diekhans ([e-mail])
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_MakeTcpClientChannel(sock)
    ClientData sock;		/* The socket to wrap up into a channel. */
{
    SocketInfo *infoPtr;
    char channelName[20];

    if (TclHasSockets(NULL) != TCL_OK) {
	return NULL;
    }

    /*
     * Set kernel space buffering and non-blocking.
     */

    TclSockMinimumBuffers((SOCKET) sock, TCP_BUFFER_SIZE);