tclunixchan.c

linux系统下的音频通信

 *
 *----------------------------------------------------------------------
 */

static int
WaitForConnect(statePtr, errorCodePtr)
    TcpState *statePtr;		/* State of the socket. */
    int *errorCodePtr;		/* Where to store errors? */
{
    int timeOut;		/* How long to wait. */
    int state;			/* Of calling TclWaitForFile. */
    int flags;			/* fcntl flags for the socket. */

    /*
     * If an asynchronous connect is in progress, attempt to wait for it
     * to complete before reading.
     */
    
    if (statePtr->flags & TCP_ASYNC_CONNECT) {
        if (statePtr->flags & TCP_ASYNC_SOCKET) {
            timeOut = 0;
        } else {
            timeOut = -1;
        }
        errno = 0;
        state = TclUnixWaitForFile(statePtr->fd,
		TCL_WRITABLE | TCL_EXCEPTION, timeOut);
        if (!(statePtr->flags & TCP_ASYNC_SOCKET)) {
#ifndef	USE_FIONBIO
            flags = fcntl(statePtr->fd, F_GETFL);
            flags &= (~(O_NONBLOCK));
            (void) fcntl(statePtr->fd, F_SETFL, flags);
#endif

#ifdef	USE_FIONBIO
            flags = 0;
            (void) ioctl(statePtr->fd, FIONBIO, &flags);
#endif
        }
        if (state & TCL_EXCEPTION) {
            return -1;
        }
        if (state & TCL_WRITABLE) {
            statePtr->flags &= (~(TCP_ASYNC_CONNECT));
        } else if (timeOut == 0) {
            *errorCodePtr = errno = EWOULDBLOCK;
            return -1;
        }
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpInputProc --
 *
 *	This procedure is invoked by the generic IO level to read input
 *	from a TCP socket based channel.
 *
 *	NOTE: We cannot share code with FilePipeInputProc because here
 *	we must use recv to obtain the input from the channel, not read.
 *
 * Results:
 *	The number of bytes read is returned or -1 on error. An output
 *	argument contains the POSIX error code on error, or zero if no
 *	error occurred.
 *
 * Side effects:
 *	Reads input from the input device of the channel.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
static int
TcpInputProc(instanceData, buf, bufSize, errorCodePtr)
    ClientData instanceData;		/* Socket state. */
    char *buf;				/* Where to store data read. */
    int bufSize;			/* How much space is available
                                         * in the buffer? */
    int *errorCodePtr;			/* Where to store error code. */
{
    TcpState *statePtr = (TcpState *) instanceData;
    int bytesRead, state;

    *errorCodePtr = 0;
    state = WaitForConnect(statePtr, errorCodePtr);
    if (state != 0) {
        return -1;
    }
    bytesRead = recv(statePtr->fd, buf, bufSize, 0);
    if (bytesRead > -1) {
        return bytesRead;
    }
    if (errno == ECONNRESET) {

        /*
         * Turn ECONNRESET into a soft EOF condition.
         */
        
        return 0;
    }
    *errorCodePtr = errno;
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpOutputProc --
 *
 *	This procedure is invoked by the generic IO level to write output
 *	to a TCP socket based channel.
 *
 *	NOTE: We cannot share code with FilePipeOutputProc because here
 *	we must use send, not write, to get reliable error reporting.
 *
 * Results:
 *	The number of bytes written is returned. An output argument is
 *	set to a POSIX error code if an error occurred, or zero.
 *
 * Side effects:
 *	Writes output on the output device of the channel.
 *
 *----------------------------------------------------------------------
 */

static int
TcpOutputProc(instanceData, buf, toWrite, errorCodePtr)
    ClientData instanceData;		/* Socket state. */
    char *buf;				/* The data buffer. */
    int toWrite;			/* How many bytes to write? */
    int *errorCodePtr;			/* Where to store error code. */
{
    TcpState *statePtr = (TcpState *) instanceData;
    int written;
    int state;				/* Of waiting for connection. */

    *errorCodePtr = 0;
    state = WaitForConnect(statePtr, errorCodePtr);
    if (state != 0) {
        return -1;
    }
    written = send(statePtr->fd, buf, toWrite, 0);
    if (written > -1) {
        return written;
    }
    *errorCodePtr = errno;
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpCloseProc --
 *
 *	This procedure is invoked by the generic IO level to perform
 *	channel-type-specific cleanup when a TCP socket based channel
 *	is closed.
 *
 * Results:
 *	0 if successful, the value of errno if failed.
 *
 * Side effects:
 *	Closes the socket of the channel.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
static int
TcpCloseProc(instanceData, interp)
    ClientData instanceData;	/* The socket to close. */
    Tcl_Interp *interp;		/* For error reporting - unused. */
{
    TcpState *statePtr = (TcpState *) instanceData;
    int errorCode = 0;

    /*
     * Delete a file handler that may be active for this socket if this
     * is a server socket - the file handler was created automatically
     * by Tcl as part of the mechanism to accept new client connections.
     * Channel handlers are already deleted in the generic IO channel
     * closing code that called this function, so we do not have to
     * delete them here.
     */
    
    Tcl_DeleteFileHandler(statePtr->fd);

    if (close(statePtr->fd) < 0) {
	errorCode = errno;
    }
    ckfree((char *) statePtr);

    return errorCode;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpGetOptionProc --
 *
 *	Computes an option value for a TCP socket based channel, or a
 *	list of all options and their values.
 *
 *	Note: This code is based on code contributed by John Haxby.
 *
 * Results:
 *	A standard Tcl result. The value of the specified option or a
 *	list of all options and	their values is returned in the
 *	supplied DString. Sets Error message if needed.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TcpGetOptionProc(instanceData, interp, optionName, dsPtr)
    ClientData instanceData;     /* Socket state. */
    Tcl_Interp *interp;          /* For error reporting - can be NULL. */
    char *optionName;	         /* Name of the option to
				  * retrieve the value for, or
				  * NULL to get all options and
				  * their values. */
    Tcl_DString *dsPtr;	         /* Where to store the computed
				  * value; initialized by caller. */
{
    TcpState *statePtr = (TcpState *) instanceData;
    struct sockaddr_in sockname;
    struct sockaddr_in peername;
    struct hostent *hostEntPtr;
    int size = sizeof(struct sockaddr_in);
    size_t len = 0;
    char buf[128];

    if (optionName != (char *) NULL) {
        len = strlen(optionName);
    }

    if ((len == 0) ||
            ((len > 1) && (optionName[1] == 'p') &&
                    (strncmp(optionName, "-peername", len) == 0))) {
        if (getpeername(statePtr->fd, (struct sockaddr *) &peername, &size)
		>= 0) {
            if (len == 0) {
                Tcl_DStringAppendElement(dsPtr, "-peername");
                Tcl_DStringStartSublist(dsPtr);
            }
            Tcl_DStringAppendElement(dsPtr, inet_ntoa(peername.sin_addr));
            hostEntPtr = gethostbyaddr((char *) &(peername.sin_addr),
                    sizeof(peername.sin_addr), AF_INET);
            if (hostEntPtr != (struct hostent *) NULL) {
                Tcl_DStringAppendElement(dsPtr, hostEntPtr->h_name);
            } else {
                Tcl_DStringAppendElement(dsPtr, inet_ntoa(peername.sin_addr));
            }
            sprintf(buf, "%d", ntohs(peername.sin_port));
            Tcl_DStringAppendElement(dsPtr, buf);
            if (len == 0) {
                Tcl_DStringEndSublist(dsPtr);
            } else {
                return TCL_OK;
            }
        } else {
            /*
             * getpeername failed - but if we were asked for all the options
             * (len==0), don't flag an error at that point because it could
             * be an fconfigure request on a server socket. (which have
             * no peer). same must be done on win&mac.
             */

            if (len) {
                if (interp) {
                    Tcl_AppendResult(interp, "can't get peername: ",
                                     Tcl_PosixError(interp),
                                     (char *) NULL);
                }
                return TCL_ERROR;
            }
        }
    }

    if ((len == 0) ||
            ((len > 1) && (optionName[1] == 's') &&
                    (strncmp(optionName, "-sockname", len) == 0))) {
        if (getsockname(statePtr->fd, (struct sockaddr *) &sockname, &size)
		>= 0) {
            if (len == 0) {
                Tcl_DStringAppendElement(dsPtr, "-sockname");
                Tcl_DStringStartSublist(dsPtr);
            }
            Tcl_DStringAppendElement(dsPtr, inet_ntoa(sockname.sin_addr));
            hostEntPtr = gethostbyaddr((char *) &(sockname.sin_addr),
                    sizeof(sockname.sin_addr), AF_INET);
            if (hostEntPtr != (struct hostent *) NULL) {
                Tcl_DStringAppendElement(dsPtr, hostEntPtr->h_name);
            } else {
                Tcl_DStringAppendElement(dsPtr, inet_ntoa(sockname.sin_addr));
            }
            sprintf(buf, "%d", ntohs(sockname.sin_port));
            Tcl_DStringAppendElement(dsPtr, buf);
            if (len == 0) {
                Tcl_DStringEndSublist(dsPtr);
            } else {
                return TCL_OK;
            }
        } else {
	    if (interp) {
		Tcl_AppendResult(interp, "can't get sockname: ",
				 Tcl_PosixError(interp),
				 (char *) NULL);
	    }
	    return TCL_ERROR;
	}
    }

    if (len > 0) {
        return Tcl_BadChannelOption(interp, optionName, "peername sockname");
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpWatchProc --
 *
 *	Initialize the notifier to watch the fd from this channel.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Sets up the notifier so that a future event on the channel will
 *	be seen by Tcl.
 *
 *----------------------------------------------------------------------
 */

static void
TcpWatchProc(instanceData, mask)
    ClientData instanceData;		/* The socket state. */
    int mask;				/* Events of interest; an OR-ed
                                         * combination of TCL_READABLE,
                                         * TCL_WRITABLE and TCL_EXCEPTION. */
{
    TcpState *statePtr = (TcpState *) instanceData;

    /*
     * Make sure we don't mess with server sockets since they will never
     * be readable or writable at the Tcl level.  This keeps Tcl scripts
     * from interfering with the -accept behavior.
     */

    if (!statePtr->acceptProc) {
	if (mask) {
	    Tcl_CreateFileHandler(statePtr->fd, mask,
		    (Tcl_FileProc *) Tcl_NotifyChannel,
		    (ClientData) statePtr->channel);
	} else {
	    Tcl_DeleteFileHandler(statePtr->fd);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TcpGetHandleProc --
 *
 *	Called from Tcl_GetChannelFile to retrieve OS handles from inside
 *	a TCP socket based channel.
 *
 * Results:
 *	Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if
 *	there is no handle for the specified direction. 
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
static int
TcpGetHandleProc(instanceData, direction, handlePtr)
    ClientData instanceData;	/* The socket state. */
    int direction;		/* Not used. */
    ClientData *handlePtr;	/* Where to store the handle.  */
{
    TcpState *statePtr = (TcpState *) instanceData;

    *handlePtr = (ClientData)statePtr->fd;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * CreateSocket --
 *
 *	This function opens a new socket in client or server mode
 *	and initializes the TcpState structure.
 *
 * Results:
 *	Returns a new TcpState, or NULL with an error in interp->result,
 *	if interp is not NULL.
 *
 * Side effects:
 *	Opens a socket.
 *
 *----------------------------------------------------------------------
 */

static TcpState *
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.
				 * NULL implies INADDR_ANY */
    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 and creating a client socket,
                                 * attempt to do an async connect. Otherwise
                                 * do a synchronous connect or bind. */
{
    int status, sock, asyncConnect, curState, origState;
    struct sockaddr_in sockaddr;	/* socket address */
    struct sockaddr_in mysockaddr;	/* Socket address for client */
    TcpState *statePtr;

    sock = -1;
    origState = 0;
    if (! CreateSocketAddress(&sockaddr, host, port)) {
	goto addressError;
    }
    if ((myaddr != NULL || myport != 0) &&
	    ! CreateSocketAddress(&mysockaddr, myaddr, myport)) {
	goto addressError;
    }

    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
	goto addressError;
    }

    /*
     * Set the close-on-exec flag so that the socket will not get
     * inherited by child processes.
     */

    fcntl(sock, F_SETFD, FD_CLOEXEC);
    
    /*
     * Set kernel space buffering
     */

    TclSockMinimumBuffers(sock, SOCKET_BUFSIZE);

    asyncConnect = 0;
    status = 0;
    if (server) {

	/*
	 * Set up to reuse server addresses automatically and bind to the
	 * specified port.
	 */