Tcl Source Code

an unused port for use as a server socket.  The port number actually
allocated may be retrieved from the created server socket using the
\fBchan configure\fR command to retrieve the \fB\-sockname\fR option as
described below.
.SH "CONFIGURATION OPTIONS"
.PP
The \fBchan configure\fR command can be used to query several readonly
configuration options for socket channels:
configuration options for socket channels or in some cases to set
alternative properties on socket channels:
.TP
\fB\-error\fR
.
This option gets the current error status of the given socket.  This
is useful when you need to determine if an asynchronous connect
operation succeeded.  If there was an error, the error message is
returned.  If there was no error, an empty string is returned.

address, the host name and the port to which the peer socket is connected
or bound. If the host name cannot be computed, the second element of the
list is identical to the address, its first element.
.TP
\fB\-connecting\fR
.
This option is not supported by server sockets. For client sockets, this option returns 1 if an asyncroneous connect is still in progress, 0 otherwise.
.TP
\fB\-keepalive\fR
.
This option sets or queries the TCP keepalive option on the socket as 1 if
keepalive is turned on, 0 otherwise.
.TP
\fB\-nodelay\fR
.
This option sets or queries the TCP nodelay option on the socket as 1 if
nodelay is turned on, 0 otherwise.
.PP
.SH "EXAMPLES"
.PP
Here is a very simple time server:
.PP
.CS
proc Server {startTime channel clientaddr clientport} {

} -returnCodes error -cleanup {
    catch {close $chan}
} -result [expectedOpts "-buffer" {}]
removeFile fconfigure.dummy
test iocmd-8.14 {fconfigure command} {
    fconfigure stdin -buffers
} 4096
test iocmd-8.15.1 {fconfigure command / tcp channel} -constraints {socket unixOrWin} -setup {
test iocmd-8.15 {fconfigure command / tcp channel} -constraints {socket unixOrWin} -setup {
    set srv [socket -server iocmdSRV -myaddr 127.0.0.1 0]
    set port [lindex [fconfigure $srv -sockname] 2]
    proc iocmdSRV {sock ip port} {close $sock}
    set cli [socket 127.0.0.1 $port]
} -body {
    fconfigure $cli -blah
} -cleanup {
    close $cli
    close $srv
    unset cli srv port
    rename iocmdSRV {}
} -returnCodes error -result [expectedOpts "-blah" {-connecting -peername -sockname}]
} -returnCodes error -result [expectedOpts "-blah" {-connecting -keepalive -nodelay -peername -sockname}]
test iocmd-8.16 {fconfigure command / tcp channel} -constraints socket -setup {
    set srv [socket -server iocmdSRV -myaddr 127.0.0.1 0]
    set port [lindex [fconfigure $srv -sockname] 2]
    proc iocmdSRV {sock ip port} {close $sock}
    set cli [socket 127.0.0.1 $port]
} -body {
    expr {[lindex [fconfigure $cli -peername] 2] == $port}

} -result {3 1 0}
test socket_$af-7.3 {testing socket specific options} -constraints [list socket supported_$af] -body {
    set s [socket -server accept -myaddr $localhost 0]
    set l [fconfigure $s]
    close $s
    update
    llength $l
} -result 14
} -result 18
test socket_$af-7.4 {testing socket specific options} -constraints [list socket supported_$af] -setup {
    set timer [after 10000 "set x timed_out"]
    set l ""
} -body {
    set s [socket -server accept -myaddr $localhost 0]
    proc accept {s a p} {
	global x

/*
 * tclUnixSock.c --
 *
 *	This file contains Unix-specific socket related code.
 *
 * Copyright © 1995 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include <netinet/tcp.h>
#include "tclInt.h"

/*
 * Helper macros to make parts of this file clearer. The macros do exactly
 * what they say on the tin. :-) They also only ever refer to their arguments
 * once, and so can be used without regard to side effects.
 */

static int		TcpGetOptionProc(void *instanceData,
			    Tcl_Interp *interp, const char *optionName,
			    Tcl_DString *dsPtr);
static int		TcpInputProc(void *instanceData, char *buf,
			    int toRead, int *errorCode);
static int		TcpOutputProc(void *instanceData,
			    const char *buf, int toWrite, int *errorCode);
static int		TcpSetOptionProc(void *instanceData,
			    Tcl_Interp *interp, const char *optionName,
			    const char *value);
static void		TcpThreadActionProc(void *instanceData, int action);
static void		TcpWatchProc(void *instanceData, int mask);
static int		WaitForConnect(TcpState *statePtr, int *errorCodePtr);
static void		WrapNotify(void *clientData, int mask);

/*
 * This structure describes the channel type structure for TCP socket

    TcpCloseProc,		/* Close proc. */
#else
    TCL_CLOSE2PROC,		/* Close proc. */
#endif
    TcpInputProc,		/* Input proc. */
    TcpOutputProc,		/* Output proc. */
    NULL,			/* Seek proc. */
    NULL,			/* Set option proc. */
    TcpSetOptionProc,		/* Set option proc. */
    TcpGetOptionProc,		/* Get option proc. */
    TcpWatchProc,		/* Initialize notifier. */
    TcpGetHandleProc,		/* Get OS handles out of channel. */
    TcpClose2Proc,		/* Close2 proc. */
    TcpBlockModeProc,		/* Set blocking or non-blocking mode.*/
    NULL,			/* flush proc. */
    NULL,			/* handler proc. */

    }
    Tcl_DStringAppendElement(dsPtr, nport);
}

/*
 *----------------------------------------------------------------------
 *
 * TcpSetOptionProc --
 *
 *	Sets TCP channel specific options.
 *
 * Results:
 *	None, unless an error happens.
 *
 * Side effects:
 *	Changes attributes of the socket at the system level.
 *
 *----------------------------------------------------------------------
 */

static int
TcpSetOptionProc(
    void *instanceData,		/* Socket state. */
    Tcl_Interp *interp,		/* For error reporting - can be NULL. */
    const char *optionName,	/* Name of the option to set. */
    const char *value)		/* New value for option. */
{
    TcpState *statePtr = (TcpState *)instanceData;
    size_t len = 0;

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

    if ((len > 1) && (optionName[1] == 'k') &&
	    (strncmp(optionName, "-keepalive", len) == 0)) {
	int val = 0, ret;

	if (Tcl_GetBoolean(interp, value, &val) != TCL_OK) {
	    return TCL_ERROR;
	}
#if defined(SO_KEEPALIVE)
	ret = setsockopt(statePtr->fds.fd, SOL_SOCKET, SO_KEEPALIVE,
		(const char *) &val, sizeof(int));
#else
	ret = -1;
	Tcl_SetErrno(ENOTSUP);
#endif
	if (ret < 0) {
	    if (interp) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"couldn't set socket option: %s",
			Tcl_PosixError(interp)));
	    }
	    return TCL_ERROR;
	}
	return TCL_OK;
    }
    if ((len > 1) && (optionName[1] == 'n') &&
	    (strncmp(optionName, "-nodelay", len) == 0)) {
	int val = 0, ret;

	if (Tcl_GetBoolean(interp, value, &val) != TCL_OK) {
	    return TCL_ERROR;
	}
#if defined(SOL_TCP) && defined(TCP_NODELAY)
	ret = setsockopt(statePtr->fds.fd, SOL_TCP, TCP_NODELAY,
		(const char *) &val, sizeof(int));
#else
	ret = -1;
	Tcl_SetErrno(ENOTSUP);
#endif
	if (ret < 0) {
	    if (interp) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"couldn't set socket option: %s",
			Tcl_PosixError(interp)));
	    }
	    return TCL_ERROR;
	}
	return TCL_OK;
    }
    return Tcl_BadChannelOption(interp, optionName, "keepalive nodelay");
}

/*
 *----------------------------------------------------------------------
 *
 * 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(
    void *instanceData,	/* Socket state. */
    void *instanceData,		/* Socket state. */
    Tcl_Interp *interp,		/* For error reporting - can be NULL. */
    const 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;
    size_t len = 0;

    WaitForConnect(statePtr, NULL);

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

    if ((len > 1) && (optionName[1] == 'e') &&
	    (strncmp(optionName, "-error", len) == 0)) {
	socklen_t optlen = sizeof(int);

	WaitForConnect(statePtr, NULL);
        if (GOT_BITS(statePtr->flags, TCP_ASYNC_CONNECT)) {
            /*
             * Suppress errors as long as we are not done.
             */

            errno = 0;
        } else if (statePtr->connectError != 0) {

	    Tcl_DStringAppend(dsPtr, Tcl_ErrnoMsg(errno), TCL_INDEX_NONE);
        }
	return TCL_OK;
    }

    if ((len > 1) && (optionName[1] == 'c') &&
	    (strncmp(optionName, "-connecting", len) == 0)) {
	WaitForConnect(statePtr, NULL);
	Tcl_DStringAppend(dsPtr,
		GOT_BITS(statePtr->flags, TCP_ASYNC_CONNECT) ? "1" : "0", TCL_INDEX_NONE);
        return TCL_OK;
    }

    if ((len == 0) || ((len > 1) && (optionName[1] == 'p') &&
	    (strncmp(optionName, "-peername", len) == 0))) {
        address peername;
        socklen_t size = sizeof(peername);

	WaitForConnect(statePtr, NULL);
	if (GOT_BITS(statePtr->flags, TCP_ASYNC_CONNECT)) {
	    /*
	     * In async connect output an empty string
	     */

	    if (len == 0) {
		Tcl_DStringAppendElement(dsPtr, "-peername");

    if ((len == 0) || ((len > 1) && (optionName[1] == 's') &&
	    (strncmp(optionName, "-sockname", len) == 0))) {
	TcpFdList *fds;
        address sockname;
        socklen_t size;
	int found = 0;

	WaitForConnect(statePtr, NULL);
	if (len == 0) {
	    Tcl_DStringAppendElement(dsPtr, "-sockname");
	    Tcl_DStringStartSublist(dsPtr);
	}
	if (GOT_BITS(statePtr->flags, TCP_ASYNC_CONNECT)) {
	    /*
	     * In async connect output an empty string

            if (interp) {
                Tcl_SetObjResult(interp, Tcl_ObjPrintf(
                        "can't get sockname: %s", Tcl_PosixError(interp)));
            }
	    return TCL_ERROR;
	}
    }

    if ((len == 0) || ((len > 1) && (optionName[1] == 'k') &&
	    (strncmp(optionName, "-keepalive", len) == 0))) {
        socklen_t size;
	int opt = 0;

	if (len == 0) {
	    Tcl_DStringAppendElement(dsPtr, "-keepalive");
	}
#if defined(SO_KEEPALIVE)
	getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_KEEPALIVE,
		(char *) &opt, &size);
#endif
	Tcl_DStringAppendElement(dsPtr, opt ? "1" : "0");
    if (len > 0) {
	if (len > 0) {
	    return TCL_OK;
	}
    }

    if ((len == 0) || ((len > 1) && (optionName[1] == 'n') &&
	    (strncmp(optionName, "-nodelay", len) == 0))) {
        socklen_t size;
	int opt = 0;

	if (len == 0) {
	    Tcl_DStringAppendElement(dsPtr, "-nodelay");
	}
#if defined(SOL_TCP) && defined(TCP_NODELAY)
	getsockopt(statePtr->fds.fd, SOL_TCP, TCP_NODELAY,
		(char *) &opt, &size);
#endif
	Tcl_DStringAppendElement(dsPtr, opt ? "1" : "0");
	if (len > 0) {
	    return TCL_OK;
	}
    }

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

    return TCL_OK;
}

/*
 * ----------------------------------------------------------------------

#include "tclWinInt.h"

#ifdef _MSC_VER
#   pragma comment (lib, "ws2_32")
#endif

/*
 * Support for control over sockets' KEEPALIVE and NODELAY behavior is
 * currently disabled.
 */

#undef TCL_FEATURE_KEEPALIVE_NAGLE

/*
 * Helper macros to make parts of this file clearer. The macros do exactly
 * what they say on the tin. :-) They also only ever refer to their arguments
 * once, and so can be used without regard to side effects.
 */

#define SET_BITS(var, bits)	((var) |= (bits))

 */

static int
TcpSetOptionProc(
    void *instanceData,	/* Socket state. */
    Tcl_Interp *interp,		/* For error reporting - can be NULL. */
    const char *optionName,	/* Name of the option to set. */
    TCL_UNUSED(const char *) /*value*/)		/* New value for option. */
    const char *value)		/* New value for option. */
{
#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
    TcpState *statePtr = instanceData;
    TcpState *statePtr = (TcpState *)instanceData;
    SOCKET sock;
#else
    (void)instanceData;
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/
    size_t len = 0;

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

    /*
     * 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 (!SocketsEnabled()) {
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "winsock is not initialized", -1));
	}
	return TCL_ERROR;
    }

#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
#error "TCL_FEATURE_KEEPALIVE_NAGLE not reviewed for whether to treat statePtr->sockets as single fd or list"
    sock = statePtr->sockets->fd;

    if ((len > 1) && (optionName[1] == 'k') &&
    if (!strcasecmp(optionName, "-keepalive")) {
	BOOL val = FALSE;
	    (strncmp(optionName, "-keepalive", len) == 0)) {
	BOOL val;
	int boolVar, rtn;

	if (Tcl_GetBoolean(interp, value, &boolVar) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (boolVar) {
	    val = TRUE;
	val = boolVar ? TRUE : FALSE;
	}
	rtn = setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
		(const char *) &val, sizeof(BOOL));
	if (rtn != 0) {
	    Tcl_WinConvertError(WSAGetLastError());
	    if (interp) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"couldn't set socket option: %s",
			Tcl_PosixError(interp)));
	    }
	    return TCL_ERROR;
	}
	return TCL_OK;
    }
    if ((len > 1) && (optionName[1] == 'n') &&
    } else if (!strcasecmp(optionName, "-nagle")) {
	BOOL val = FALSE;
	(strncmp(optionName, "-nodelay", len) == 0)) {
	BOOL val;
	int boolVar, rtn;

	if (Tcl_GetBoolean(interp, value, &boolVar) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (!boolVar) {
	    val = TRUE;
	val = boolVar ? TRUE : FALSE;
	}
	rtn = setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
		(const char *) &val, sizeof(BOOL));
	if (rtn != 0) {
	    Tcl_WinConvertError(WSAGetLastError());
	    if (interp) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"couldn't set socket option: %s",
			Tcl_PosixError(interp)));
	    }
	    return TCL_ERROR;
	}
	return TCL_OK;
    }

    return Tcl_BadChannelOption(interp, optionName, "keepalive nagle");
    return Tcl_BadChannelOption(interp, optionName, "keepalive nodelay");
#else
    return Tcl_BadChannelOption(interp, optionName, "");
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/
}

/*
 *----------------------------------------------------------------------
 *
 * TcpGetOptionProc --
 *

		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"can't get sockname: %s", Tcl_PosixError(interp)));
	    }
	    return TCL_ERROR;
	}
    }

#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
    if (len == 0 || !strncmp(optionName, "-keepalive", len)) {
    if ((len == 0) || ((len > 1) && (optionName[1] == 'k') &&
	    (strncmp(optionName, "-keepalive", len) == 0))) {
	int optlen;
	BOOL opt = FALSE;

	if (len == 0) {
	    sock = statePtr->sockets->fd;
	    Tcl_DStringAppendElement(dsPtr, "-keepalive");
	}
	optlen = sizeof(BOOL);
	getsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (char *)&opt, &optlen);
	if (opt) {
	    Tcl_DStringAppendElement(dsPtr, "1");
	} else {
	    Tcl_DStringAppendElement(dsPtr, "0");
	Tcl_DStringAppendElement(dsPtr, opt ? "1" : "0");
	if (len > 0) {
	    return TCL_OK;
	}
    }

    if ((len == 0) || ((len > 1) && (optionName[1] == 'n') &&
	    (strncmp(optionName, "-nodelay", len) == 0))) {
	int optlen;
	BOOL opt = FALSE;

	if (len == 0) {
	    sock = statePtr->sockets->fd;
	    Tcl_DStringAppendElement(dsPtr, "-nodelay");
	}
	optlen = sizeof(BOOL);
	getsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (char *)&opt, &optlen);
	Tcl_DStringAppendElement(dsPtr, opt ? "1" : "0");
	if (len > 0) {
	    return TCL_OK;
	}
    }

    if (len == 0 || !strncmp(optionName, "-nagle", len)) {
	int optlen;
	BOOL opt = FALSE;

	if (len == 0) {
	    Tcl_DStringAppendElement(dsPtr, "-nagle");
	}
	optlen = sizeof(BOOL);
	getsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (char *)&opt, &optlen);
	if (opt) {
	    Tcl_DStringAppendElement(dsPtr, "0");
	} else {
	    Tcl_DStringAppendElement(dsPtr, "1");
	}
	if (len > 0) {
    if (len > 0) {
	    return TCL_OK;
	}
    }
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/

    if (len > 0) {
#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
	return Tcl_BadChannelOption(interp, optionName,
		"connecting peername sockname keepalive nagle");
#else
	return Tcl_BadChannelOption(interp, optionName,
                "connecting peername sockname");
		"connecting keepalive nodelay peername sockname");
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------

    void **handlePtr)	/* Where to store the handle. */
{
    TcpState *statePtr = (TcpState *)instanceData;

    *handlePtr = INT2PTR(statePtr->sockets->fd);
    return TCL_OK;
}



/*
 *----------------------------------------------------------------------
 *
 * TcpConnect --
 *
 *	This function opens a new socket in client mode.