State *statePtr = (State *)instanceData;

    if (mode == TCL_MODE_NONBLOCKING) {
	statePtr->flags |= TLS_TCL_ASYNC;
    } else {
	statePtr->flags &= ~(TLS_TCL_ASYNC);
    }
    return 0;
}

/*
 *-------------------------------------------------------------------
 *
 * TlsClose2Proc --
 *

 *
 *------------------------------------------------------*
 */
int Tls_WaitForConnect(State *statePtr, int *errorCodePtr, int handshakeFailureIsPermanent) {
    unsigned long backingError;
    int err, rc;
    int bioShouldRetry;
    *errorCodePtr = 0;

    dprintf("WaitForConnect(%p)", statePtr);
    dprintFlags(statePtr);

    if (!(statePtr->flags & TLS_TCL_INIT)) {
	dprintf("Tls_WaitForConnect called on already initialized channel -- returning with immediate success");

	return 0;
    }

    if (statePtr->flags & TLS_TCL_HANDSHAKE_FAILED) {
	/*
	 * Different types of operations have different requirements
	 * SSL being established
	 */
	if (handshakeFailureIsPermanent) {
	    dprintf("Asked to wait for a TLS handshake that has already failed.  Returning fatal error");
	    *errorCodePtr = ECONNABORTED;
	} else {
	    dprintf("Asked to wait for a TLS handshake that has already failed.  Returning soft error");
	    *errorCodePtr = ECONNRESET;
	}
	Tls_Error(statePtr, "Wait for failed handshake");
	return -1;
    }

    for (;;) {
	ERR_clear_error();

	/* Not initialized yet! Also calls SSL_do_handshake. */
	if (statePtr->flags & TLS_TCL_SERVER) {
	    dprintf("Calling SSL_accept()");
	    err = SSL_accept(statePtr->ssl);

	} else {
	    dprintf("Calling SSL_connect()");
	    err = SSL_connect(statePtr->ssl);
	}

	if (err > 0) {
	    dprintf("Accept or connect was successful");

	    err = BIO_flush(statePtr->bio);
	    if (err <= 0) {
		dprintf("Flushing the lower layers failed, this will probably terminate this session");
	    }
	} else {
	    dprintf("Accept or connect failed");
	}

	rc = SSL_get_error(statePtr->ssl, err);
	backingError = ERR_get_error();
	if (rc != SSL_ERROR_NONE) {
	    dprintf("Got error: %i (rc = %i)", err, rc);
	    dprintf("Got error: %s", ERR_reason_error_string(backingError));
	}

	bioShouldRetry = 0;
	if (err <= 0) {
	    if (rc == SSL_ERROR_WANT_CONNECT || rc == SSL_ERROR_WANT_ACCEPT || rc == SSL_ERROR_WANT_READ || rc == SSL_ERROR_WANT_WRITE) {
		bioShouldRetry = 1;
	    } else if (BIO_should_retry(statePtr->bio)) {
		bioShouldRetry = 1;

	if (bioShouldRetry) {
	    dprintf("The I/O did not complete -- but we should try it again");

	    if (statePtr->flags & TLS_TCL_ASYNC) {
		dprintf("Returning EAGAIN so that it can be retried later");
		*errorCodePtr = EAGAIN;
		Tls_Error(statePtr, "Handshake not complete, will retry later");
		return -1;
	    } else {
		dprintf("Doing so now");
		continue;
	    }
	}

	dprintf("We have either completely established the session or completely failed it -- there is no more need to ever retry it though");
	break;
    }




    switch (rc) {
	case SSL_ERROR_NONE:
	    /* The TLS/SSL I/O operation completed */
	    dprintf("The connection is good");
	    *errorCodePtr = 0;
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    /* The TLS/SSL peer has closed the connection for writing by sending the close_notify alert */
	    dprintf("SSL_ERROR_ZERO_RETURN: Connect returned an invalid value...");
	    *errorCodePtr = EINVAL;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    return -1;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */
	    dprintf("SSL_ERROR_SYSCALL");

	    if (backingError == 0 && err == 0) {
		dprintf("EOF reached")
		*errorCodePtr = ECONNRESET;
		Tls_Error(statePtr, "(unexpected) EOF reached");

	    } else if (backingError == 0 && err == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		if (*errorCodePtr == ECONNRESET) {
		    *errorCodePtr = ECONNABORTED;
		}
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		if (*errorCodePtr == ECONNRESET) {
		    *errorCodePtr = ECONNABORTED;
		}
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }

	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    return -1;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL_ERROR_SSL: Got permanent fatal SSL error, aborting immediately");
	    if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    }
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }
	    statePtr->flags |= TLS_TCL_HANDSHAKE_FAILED;
	    *errorCodePtr = ECONNABORTED;
	    return -1;
	default:
	    /* The operation did not complete and should be retried later. */
	    dprintf("Operation did not complete, call function again later: %i", rc);
	    *errorCodePtr = EAGAIN;
	    dprintf("ERR(%d, %d) ", rc, *errorCodePtr);


	    Tls_Error(statePtr, "Operation did not complete, call function again later");











	    return -1;
    }



    dprintf("Removing the \"TLS_TCL_INIT\" flag since we have completed the handshake");
    statePtr->flags &= ~TLS_TCL_INIT;

    dprintf("Returning in success");
    *errorCodePtr = 0;
    return 0;

    *errorCodePtr = 0;

    dprintf("BIO_read(%d)", bufSize);

    if (statePtr->flags & TLS_TCL_CALLBACK) {
	/* don't process any bytes while verify callback is running */
	dprintf("Callback is running, reading 0 bytes");
	return 0;
    }

    dprintf("Calling Tls_WaitForConnect");
    tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 0);
    if (tlsConnect < 0) {
	dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	Tls_Error(statePtr, strerror(*errorCodePtr));

	bytesRead = -1;
	if (*errorCodePtr == ECONNRESET) {
	    dprintf("Got connection reset");
	    /* Soft EOF */
	    *errorCodePtr = 0;
	    bytesRead = 0;
	}
	return bytesRead;
    }

    /*
     * We need to clear the SSL error stack now because we sometimes reach
     * this function with leftover errors in the stack.  If BIO_read
     * returns -1 and intends EAGAIN, there is a leftover error, it will be
     * misconstrued as an error, not EAGAIN.
     *
     * Alternatively, we may want to handle the <0 return codes from
     * BIO_read specially (as advised in the RSA docs).  TLS's lower level BIO
     * functions play with the retry flags though, and this seems to work
     * correctly.  Similar fix in TlsOutputProc. - hobbs
     */
    ERR_clear_error();
    bytesRead = BIO_read(statePtr->bio, buf, bufSize);
    dprintf("BIO_read -> %d", bytesRead);

    err = SSL_get_error(statePtr->ssl, bytesRead);
    backingError = ERR_get_error();

#if 0
    if (bytesRead <= 0) {
	if (BIO_should_retry(statePtr->bio)) {
	    dprintf("I/O failed, will retry based on EAGAIN");
	    *errorCodePtr = EAGAIN;
	}
    }
#endif

    switch (err) {
	case SSL_ERROR_NONE:
	    dprintBuffer(buf, bytesRead);
	    break;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }

	    *errorCodePtr = ECONNABORTED;
	    bytesRead = -1;

#if OPENSSL_VERSION_NUMBER >= 0x30000000L
	    /* Unexpected EOF from the peer for OpenSSL 3.0+ */
	    if (ERR_GET_REASON(backingError) == SSL_R_UNEXPECTED_EOF_WHILE_READING) {
		dprintf("(Unexpected) EOF reached")
		*errorCodePtr = 0;
		bytesRead = 0;
		Tls_Error(statePtr, "EOF reached");
	    }
#endif
	    break;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */

	    if (backingError == 0 && bytesRead == 0) {
		/* Unexpected EOF from the peer for OpenSSL 1.1 */
		dprintf("(Unexpected) EOF reached")
		*errorCodePtr = 0;
		bytesRead = 0;
		Tls_Error(statePtr, "EOF reached");

	    } else if (backingError == 0 && bytesRead == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		bytesRead = -1;
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		bytesRead = -1;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }

	    break;

	case SSL_ERROR_ZERO_RETURN:
	    dprintf("Got SSL_ERROR_ZERO_RETURN, this means an EOF has been reached");
	    bytesRead = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf("Got SSL_ERROR_WANT_READ, mapping this to EAGAIN");
	    bytesRead = -1;
	    *errorCodePtr = EAGAIN;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	default:
	    dprintf("Unknown error (err = %i), mapping to EOF", err);
	    *errorCodePtr = 0;
	    bytesRead = 0;
	    Tls_Error(statePtr, "Unknown error");
	    break;
    }

    dprintf("Input(%d) -> %d [%d]", bufSize, bytesRead, *errorCodePtr);
    return bytesRead;
}

/*

    dprintf("BIO_write(%p, %d)", (void *) statePtr, toWrite);
    dprintBuffer(buf, toWrite);

    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Don't process output while callbacks are running");
	written = -1;
	*errorCodePtr = EAGAIN;
	return -1;
    }

    dprintf("Calling Tls_WaitForConnect");
    tlsConnect = Tls_WaitForConnect(statePtr, errorCodePtr, 1);
    if (tlsConnect < 0) {
	dprintf("Got an error waiting to connect (tlsConnect = %i, *errorCodePtr = %i)", tlsConnect, *errorCodePtr);
	Tls_Error(statePtr, strerror(*errorCodePtr));

	written = -1;
	if (*errorCodePtr == ECONNRESET) {
	    dprintf("Got connection reset");
	    /* Soft EOF */
	    *errorCodePtr = 0;
	    written = 0;
	}
	return written;
    }

    if (toWrite == 0) {
	dprintf("zero-write");
	err = BIO_flush(statePtr->bio);

	if (err <= 0) {
	    dprintf("Flushing failed");
	    Tls_Error(statePtr, "Flush failed");

	    *errorCodePtr = EIO;
	    written = 0;
	    return -1;
	}

	written = 0;
	*errorCodePtr = 0;
	return 0;
    }

    /*
     * We need to clear the SSL error stack now because we sometimes reach
     * this function with leftover errors in the stack.  If BIO_write
     * returns -1 and intends EAGAIN, there is a leftover error, it will be
     * misconstrued as an error, not EAGAIN.
     *
     * Alternatively, we may want to handle the <0 return codes from
     * BIO_write specially (as advised in the RSA docs).  TLS's lower level
     * BIO functions play with the retry flags though, and this seems to
     * work correctly.  Similar fix in TlsInputProc. - hobbs
     */
    ERR_clear_error();
    written = BIO_write(statePtr->bio, buf, toWrite);
    dprintf("BIO_write(%p, %d) -> [%d]", (void *) statePtr, toWrite, written);

    err = SSL_get_error(statePtr->ssl, written);
    backingError = ERR_get_error();

    switch (err) {
	case SSL_ERROR_NONE:
	    if (written < 0) {
		written = 0;
	    }
	    break;

	case SSL_ERROR_WANT_WRITE:
	    dprintf("Got SSL_ERROR_WANT_WRITE, mapping it to EAGAIN");
	    *errorCodePtr = EAGAIN;
	    written = -1;
	    Tls_Error(statePtr, "SSL_ERROR_WANT_WRITE");
	    break;

	case SSL_ERROR_WANT_READ:
	    dprintf(" write R BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_READ");
	    break;

	case SSL_ERROR_WANT_X509_LOOKUP:
	    dprintf(" write X BLOCK");
	    Tls_Error(statePtr, "SSL_ERROR_WANT_X509_LOOKUP");
	    break;

	case SSL_ERROR_ZERO_RETURN:
	    dprintf(" closed");
	    written = 0;
	    *errorCodePtr = 0;
	    Tls_Error(statePtr, "Peer has closed the connection for writing by sending the close_notify alert");
	    break;

	case SSL_ERROR_SYSCALL:
	    /* Some non-recoverable, fatal I/O error occurred */

	    if (backingError == 0 && written == 0) {
		dprintf("EOF reached")
		*errorCodePtr = 0;
		written = 0;
		Tls_Error(statePtr, "EOF reached");

	    } else if (backingError == 0 && written == -1) {
		dprintf("I/O error occurred (errno = %lu)", (unsigned long) Tcl_GetErrno());
		*errorCodePtr = Tcl_GetErrno();
		written = -1;
		Tls_Error(statePtr, (char *) Tcl_ErrnoMsg(*errorCodePtr));

	    } else {
		dprintf("I/O error occurred (backingError = %lu)", backingError);
		*errorCodePtr = Tcl_GetErrno();
		written = -1;
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    }
	    break;

	case SSL_ERROR_SSL:
	    /* A non-recoverable, fatal error in the SSL library occurred, usually a protocol error */
	    dprintf("SSL error, indicating that the connection has been aborted");
	    if (backingError != 0) {
		Tls_Error(statePtr, (char *) ERR_reason_error_string(backingError));
	    } else if (SSL_get_verify_result(statePtr->ssl) != X509_V_OK) {
		Tls_Error(statePtr, (char *) X509_verify_cert_error_string(SSL_get_verify_result(statePtr->ssl)));
	    } else {
		Tls_Error(statePtr, "Unknown SSL error");
	    }
	    *errorCodePtr = ECONNABORTED;
	    written = -1;
	    break;

	default:
	    dprintf("unknown error: %d", err);
	    Tls_Error(statePtr, "Unknown error");
	    break;
    }

    dprintf("Output(%d) -> %d", toWrite, written);
    return written;
}

/*
 *-------------------------------------------------------------------
 *
 * TlsSetOptionProc --
 *

TlsWatchProc(
    void *instanceData,    /* The socket state. */
    int mask)			/* Events of interest; an OR-ed combination of
				 * TCL_READABLE, TCL_WRITABLE and TCL_EXCEPTION. */
{
    Tcl_Channel     downChan;
    State *statePtr = (State *)instanceData;
    Tcl_DriverWatchProc *watchProc;

    dprintf("TlsWatchProc(0x%x)", mask);

    /* Pretend to be dead as long as the verify callback is running.
     * Otherwise that callback could be invoked recursively. */
    if (statePtr->flags & TLS_TCL_CALLBACK) {
	dprintf("Callback is on-going, doing nothing");
	return;
    }

    dprintFlags(statePtr);

    downChan = Tls_GetParent(statePtr, TLS_TCL_FASTPATH);

    if (statePtr->flags & TLS_TCL_HANDSHAKE_FAILED) {
	dprintf("Asked to watch a socket with a failed handshake -- nothing can happen here");
	dprintf("Unregistering interest in the lower channel");

	watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(downChan));
	watchProc(Tcl_GetChannelInstanceData(downChan), 0);
	statePtr->watchMask = 0;
	return;
    }

    statePtr->watchMask = mask;

    /* No channel handlers any more. We will be notified automatically
     * about events on the channel below via a call to our
     * 'TransformNotifyProc'. But we have to pass the interest down now.
     * We are allowed to add additional 'interest' to the mask if we want
     * to. But this transformation has no such interest. It just passes
     * the request down, unchanged.
     */
    dprintf("Registering our interest in the lower channel (chan=%p)", (void *) downChan);
    watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(downChan));
    watchProc(Tcl_GetChannelInstanceData(downChan), mask);

    /*
     * Management of the internal timer.
     */
    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	dprintf("A timer was found, deleting it");
	Tcl_DeleteTimerHandler(statePtr->timer);

static int TlsGetHandleProc(
    void *instanceData,    /* Socket state. */
    int direction,		/* TCL_READABLE or TCL_WRITABLE */
    void **handlePtr)	/* Handle associated with the channel */
{
    State *statePtr = (State *)instanceData;

    return Tcl_GetChannelHandle(Tls_GetParent(statePtr, TLS_TCL_FASTPATH), direction, handlePtr);
}

/*
 *-------------------------------------------------------------------
 *
 * TlsNotifyProc --
 *

	dprintf("Returning 0 due to callback");
	return 0;
    }

    dprintf("Calling Tls_WaitForConnect");
    errorCode = 0;
    if (Tls_WaitForConnect(statePtr, &errorCode, 1) < 0) {
	Tls_Error(statePtr, strerror(errorCode));
	if (errorCode == EAGAIN) {
	    dprintf("Async flag could be set (didn't check) and errorCode == EAGAIN:  Returning 0");

	    return 0;
	}

	dprintf("Tls_WaitForConnect returned an error");
    }

    dprintf("Returning %i", mask);

    return mask;
}

/*
 *------------------------------------------------------*
 *
 *    TlsChannelHandlerTimer --
 *

}

Tcl_Channel Tls_GetParent(State *statePtr, int maskFlags) {
    dprintf("Requested to get parent of channel %p", statePtr->self);

    if ((statePtr->flags & ~maskFlags) & TLS_TCL_FASTPATH) {
	dprintf("Asked to get the parent channel while we are using FastPath -- returning NULL");
	return NULL;
    }
    return Tcl_GetStackedChannel(statePtr->self);
}

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