Initial revision

1 files changed, 2113 insertions, 0 deletions

diff --git a/win/tclWinSock.c b/win/tclWinSock.c
new file mode 100644
index 0000000..bd81d2d
--- /dev/null
+++ b/win/tclWinSock.c
@@ -0,0 +1,2113 @@
+/* 
+ * tclWinSock.c --
+ *
+ *	This file contains Windows-specific socket related code.
+ *
+ * Copyright (c) 1995-1997 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * SCCS: @(#) tclWinSock.c 1.80 97/10/09 18:24:59
+ */
+
+#include "tclInt.h"
+#include "tclPort.h"
+
+/*
+ * The following variable is used to tell whether this module has been
+ * initialized.
+ */
+
+static int initialized = 0;
+
+static int  hostnameInitialized = 0;
+static char hostname[255];	/* This buffer should be big enough for
+                                 * hostname plus domain name. */
+
+/*
+ * The following structure contains pointers to all of the WinSock API entry
+ * points used by Tcl.  It is initialized by InitSockets.  Since we
+ * dynamically load Winsock.dll on demand, we must use this function table
+ * to refer to functions in the socket API.
+ */
+
+static struct {
+    HINSTANCE hInstance;	/* Handle to WinSock library. */
+    HWND hwnd;			/* Handle to window for socket messages. */
+    SOCKET (PASCAL FAR *accept)(SOCKET s, struct sockaddr FAR *addr,
+	    int FAR *addrlen);
+    int (PASCAL FAR *bind)(SOCKET s, const struct sockaddr FAR *addr,
+	    int namelen);
+    int (PASCAL FAR *closesocket)(SOCKET s);
+    int (PASCAL FAR *connect)(SOCKET s, const struct sockaddr FAR *name,
+	    int namelen);
+    int (PASCAL FAR *ioctlsocket)(SOCKET s, long cmd, u_long FAR *argp);
+    int (PASCAL FAR *getsockopt)(SOCKET s, int level, int optname,
+	    char FAR * optval, int FAR *optlen);
+    u_short (PASCAL FAR *htons)(u_short hostshort);
+    unsigned long (PASCAL FAR *inet_addr)(const char FAR * cp);
+    char FAR * (PASCAL FAR *inet_ntoa)(struct in_addr in);
+    int (PASCAL FAR *listen)(SOCKET s, int backlog);
+    u_short (PASCAL FAR *ntohs)(u_short netshort);
+    int (PASCAL FAR *recv)(SOCKET s, char FAR * buf, int len, int flags);
+    int (PASCAL FAR *send)(SOCKET s, const char FAR * buf, int len, int flags);
+    int (PASCAL FAR *setsockopt)(SOCKET s, int level, int optname,
+	    const char FAR * optval, int optlen);
+    int (PASCAL FAR *shutdown)(SOCKET s, int how);
+    SOCKET (PASCAL FAR *socket)(int af, int type, int protocol);
+    struct hostent FAR * (PASCAL FAR *gethostbyname)(const char FAR * name);
+    struct hostent FAR * (PASCAL FAR *gethostbyaddr)(const char FAR *addr,
+            int addrlen, int addrtype);
+    int (PASCAL FAR *gethostname)(char FAR * name, int namelen);
+    int (PASCAL FAR *getpeername)(SOCKET sock, struct sockaddr FAR *name,
+            int FAR *namelen);
+    struct servent FAR * (PASCAL FAR *getservbyname)(const char FAR * name,
+	    const char FAR * proto);
+    int (PASCAL FAR *getsockname)(SOCKET sock, struct sockaddr FAR *name,
+            int FAR *namelen);
+    int (PASCAL FAR *WSAStartup)(WORD wVersionRequired, LPWSADATA lpWSAData);
+    int (PASCAL FAR *WSACleanup)(void);
+    int (PASCAL FAR *WSAGetLastError)(void);
+    int (PASCAL FAR *WSAAsyncSelect)(SOCKET s, HWND hWnd, u_int wMsg,
+	    long lEvent);
+} winSock;
+
+/*
+ * The following defines declare the messages used on socket windows.
+ */
+
+#define SOCKET_MESSAGE	WM_USER+1
+
+/*
+ * The following structure is used to store the data associated with
+ * each socket.
+ */
+
+typedef struct SocketInfo {
+    Tcl_Channel channel;	   /* Channel associated with this socket. */
+    SOCKET socket;		   /* Windows SOCKET handle. */
+    int flags;			   /* Bit field comprised of the flags
+				    * described below.  */
+    int watchEvents;		   /* OR'ed combination of FD_READ, FD_WRITE,
+                                    * FD_CLOSE, FD_ACCEPT and FD_CONNECT that
+				    * indicate which events are interesting. */
+    int readyEvents;		   /* OR'ed combination of FD_READ, FD_WRITE,
+                                    * FD_CLOSE, FD_ACCEPT and FD_CONNECT that
+				    * indicate which events have occurred. */
+    int selectEvents;		   /* OR'ed combination of FD_READ, FD_WRITE,
+                                    * FD_CLOSE, FD_ACCEPT and FD_CONNECT that
+				    * indicate which events are currently
+				    * being selected. */
+    Tcl_TcpAcceptProc *acceptProc; /* Proc to call on accept. */
+    ClientData acceptProcData;	   /* The data for the accept proc. */
+    int lastError;		   /* Error code from last message. */
+    struct SocketInfo *nextPtr;	   /* The next socket on the global socket
+				    * list. */
+} SocketInfo;
+
+/*
+ * The following structure is what is added to the Tcl event queue when
+ * a socket event occurs.
+ */
+
+typedef struct SocketEvent {
+    Tcl_Event header;		/* Information that is standard for
+				 * all events. */
+    SOCKET socket;		/* Socket descriptor that is ready.  Used
+				 * to find the SocketInfo structure for
+				 * the file (can't point directly to the
+				 * SocketInfo structure because it could
+				 * go away while the event is queued). */
+} SocketEvent;
+
+/*
+ * This defines the minimum buffersize maintained by the kernel.
+ */
+
+#define TCP_BUFFER_SIZE 4096
+
+/*
+ * The following macros may be used to set the flags field of
+ * a SocketInfo structure.
+ */
+
+#define SOCKET_ASYNC		(1<<0)	/* The socket is in blocking mode. */
+#define SOCKET_EOF		(1<<1)	/* A zero read happened on
+					 * the socket. */
+#define SOCKET_ASYNC_CONNECT	(1<<2)	/* This socket uses async connect. */
+#define SOCKET_PENDING		(1<<3)	/* A message has been sent
+					 * for this socket */
+
+/*
+ * Every open socket has an entry on the following list.
+ */
+
+static SocketInfo *socketList;
+
+/*
+ * Static functions defined in this file.
+ */
+
+static SocketInfo *	CreateSocket _ANSI_ARGS_((Tcl_Interp *interp,
+			    int port, char *host, int server, char *myaddr,
+			    int myport, int async));
+static int		CreateSocketAddress _ANSI_ARGS_(
+			    (struct sockaddr_in *sockaddrPtr,
+			    char *host, int port));
+static void		InitSockets _ANSI_ARGS_((void));
+static SocketInfo *	NewSocketInfo _ANSI_ARGS_((SOCKET socket));
+static void		SocketCheckProc _ANSI_ARGS_((ClientData clientData,
+			    int flags));
+static int		SocketEventProc _ANSI_ARGS_((Tcl_Event *evPtr,
+			    int flags));
+static void		SocketExitHandler _ANSI_ARGS_((ClientData clientData));
+static LRESULT CALLBACK	SocketProc _ANSI_ARGS_((HWND hwnd, UINT message,
+			    WPARAM wParam, LPARAM lParam));
+static void		SocketSetupProc _ANSI_ARGS_((ClientData clientData,
+			    int flags));
+static void		TcpAccept _ANSI_ARGS_((SocketInfo *infoPtr));
+static int		TcpBlockProc _ANSI_ARGS_((ClientData instanceData,
+			    int mode));
+static int		TcpCloseProc _ANSI_ARGS_((ClientData instanceData,
+	            	    Tcl_Interp *interp));
+static int		TcpGetOptionProc _ANSI_ARGS_((ClientData instanceData,
+		            Tcl_Interp *interp, char *optionName,
+			    Tcl_DString *optionValue));
+static int		TcpInputProc _ANSI_ARGS_((ClientData instanceData,
+	            	    char *buf, int toRead, int *errorCode));
+static int		TcpOutputProc _ANSI_ARGS_((ClientData instanceData,
+	            	    char *buf, int toWrite, int *errorCode));
+static void		TcpWatchProc _ANSI_ARGS_((ClientData instanceData,
+		            int mask));
+static int		TcpGetHandleProc _ANSI_ARGS_((ClientData instanceData,
+		            int direction, ClientData *handlePtr));
+static int		WaitForSocketEvent _ANSI_ARGS_((SocketInfo *infoPtr,
+		            int events, int *errorCodePtr));
+
+/*
+ * This structure describes the channel type structure for TCP socket
+ * based IO.
+ */
+
+static Tcl_ChannelType tcpChannelType = {
+    "tcp",		/* Type name. */
+    TcpBlockProc,	/* Set socket into blocking/non-blocking mode. */
+    TcpCloseProc,	/* Close proc. */
+    TcpInputProc,	/* Input proc. */
+    TcpOutputProc,	/* Output proc. */
+    NULL,		/* Seek proc. */
+    NULL,		/* Set option proc. */
+    TcpGetOptionProc,	/* Get option proc. */
+    TcpWatchProc,	/* Initialize notifier to watch this channel. */
+    TcpGetHandleProc,	/* Get an OS handle from channel. */
+};
+
+/*
+ * Define version of Winsock required by Tcl.
+ */
+
+#define WSA_VERSION_REQD MAKEWORD(1,1)
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * InitSockets --
+ *
+ *	Initialize the socket module.  Attempts to load the wsock32.dll
+ *	library and set up the winSock function table.  If successful,
+ *	registers the event window for the socket notifier code.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Dynamically loads wsock32.dll, and registers a new window
+ *	class and creates a window for use in asynchronous socket
+ *	notification.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+InitSockets()
+{
+    WSADATA wsaData;
+    OSVERSIONINFO info;
+    WNDCLASS class;
+
+    initialized = 1;
+    Tcl_CreateExitHandler(SocketExitHandler, (ClientData) NULL);
+
+    /*
+     * Find out if we're running on Win32s.
+     */
+
+    info.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+    GetVersionEx(&info);
+
+    /*
+     * Check to see if Sockets are supported on this system.  Since
+     * win32s panics if we call WSAStartup on a system that doesn't
+     * have winsock.dll, we need to look for it on the system first.
+     * If we find winsock, then load the library and initialize the
+     * stub table.
+     */
+
+    if ((info.dwPlatformId != VER_PLATFORM_WIN32s)
+	    || (SearchPath(NULL, "WINSOCK", ".DLL", 0, NULL, NULL) != 0)) {
+	winSock.hInstance = LoadLibrary("wsock32.dll");
+    } else {
+	winSock.hInstance = NULL;
+    }
+
+    /*
+     * Initialize the function table.
+     */
+
+    if (winSock.hInstance == NULL) {
+	return;
+    }
+
+    winSock.accept = (SOCKET (PASCAL FAR *)(SOCKET s,
+            struct sockaddr FAR *addr, int FAR *addrlen))
+        GetProcAddress(winSock.hInstance, "accept");
+    winSock.bind = (int (PASCAL FAR *)(SOCKET s,
+            const struct sockaddr FAR *addr, int namelen))
+        GetProcAddress(winSock.hInstance, "bind");
+    winSock.closesocket = (int (PASCAL FAR *)(SOCKET s))
+        GetProcAddress(winSock.hInstance, "closesocket");
+    winSock.connect = (int (PASCAL FAR *)(SOCKET s,
+            const struct sockaddr FAR *name, int namelen))
+        GetProcAddress(winSock.hInstance, "connect");
+    winSock.ioctlsocket = (int (PASCAL FAR *)(SOCKET s, long cmd,
+            u_long FAR *argp)) GetProcAddress(winSock.hInstance, "ioctlsocket");
+    winSock.getsockopt = (int (PASCAL FAR *)(SOCKET s,
+            int level, int optname, char FAR * optval, int FAR *optlen))
+        GetProcAddress(winSock.hInstance, "getsockopt");
+    winSock.htons = (u_short (PASCAL FAR *)(u_short hostshort))
+        GetProcAddress(winSock.hInstance, "htons");
+    winSock.inet_addr = (unsigned long (PASCAL FAR *)(const char FAR *cp))
+        GetProcAddress(winSock.hInstance, "inet_addr");
+    winSock.inet_ntoa = (char FAR * (PASCAL FAR *)(struct in_addr in))
+        GetProcAddress(winSock.hInstance, "inet_ntoa");
+    winSock.listen = (int (PASCAL FAR *)(SOCKET s, int backlog))
+        GetProcAddress(winSock.hInstance, "listen");
+    winSock.ntohs = (u_short (PASCAL FAR *)(u_short netshort))
+        GetProcAddress(winSock.hInstance, "ntohs");
+    winSock.recv = (int (PASCAL FAR *)(SOCKET s, char FAR * buf,
+            int len, int flags)) GetProcAddress(winSock.hInstance, "recv");
+    winSock.send = (int (PASCAL FAR *)(SOCKET s, const char FAR * buf,
+            int len, int flags)) GetProcAddress(winSock.hInstance, "send");
+    winSock.setsockopt = (int (PASCAL FAR *)(SOCKET s, int level,
+            int optname, const char FAR * optval, int optlen))
+        GetProcAddress(winSock.hInstance, "setsockopt");
+    winSock.shutdown = (int (PASCAL FAR *)(SOCKET s, int how))
+        GetProcAddress(winSock.hInstance, "shutdown");
+    winSock.socket = (SOCKET (PASCAL FAR *)(int af, int type,
+            int protocol)) GetProcAddress(winSock.hInstance, "socket");
+    winSock.gethostbyaddr = (struct hostent FAR * (PASCAL FAR *)
+            (const char FAR *addr, int addrlen, int addrtype))
+        GetProcAddress(winSock.hInstance, "gethostbyaddr");
+    winSock.gethostbyname = (struct hostent FAR * (PASCAL FAR *)
+            (const char FAR *name))
+        GetProcAddress(winSock.hInstance, "gethostbyname");
+    winSock.gethostname = (int (PASCAL FAR *)(char FAR * name,
+            int namelen)) GetProcAddress(winSock.hInstance, "gethostname");
+    winSock.getpeername = (int (PASCAL FAR *)(SOCKET sock,
+            struct sockaddr FAR *name, int FAR *namelen))
+        GetProcAddress(winSock.hInstance, "getpeername");
+    winSock.getservbyname = (struct servent FAR * (PASCAL FAR *)
+            (const char FAR * name, const char FAR * proto))
+        GetProcAddress(winSock.hInstance, "getservbyname");
+    winSock.getsockname = (int (PASCAL FAR *)(SOCKET sock,
+            struct sockaddr FAR *name, int FAR *namelen))
+        GetProcAddress(winSock.hInstance, "getsockname");
+    winSock.WSAStartup = (int (PASCAL FAR *)(WORD wVersionRequired,
+            LPWSADATA lpWSAData)) GetProcAddress(winSock.hInstance, "WSAStartup");
+    winSock.WSACleanup = (int (PASCAL FAR *)(void))
+        GetProcAddress(winSock.hInstance, "WSACleanup");
+    winSock.WSAGetLastError = (int (PASCAL FAR *)(void))
+        GetProcAddress(winSock.hInstance, "WSAGetLastError");
+    winSock.WSAAsyncSelect = (int (PASCAL FAR *)(SOCKET s, HWND hWnd,
+            u_int wMsg, long lEvent))
+        GetProcAddress(winSock.hInstance, "WSAAsyncSelect");
+
+    /*
+     * Now check that all fields are properly initialized. If not, return
+     * zero to indicate that we failed to initialize properly.
+     */
+
+    if ((winSock.hInstance == NULL) ||
+            (winSock.accept == NULL) ||
+            (winSock.bind == NULL) ||
+            (winSock.closesocket == NULL) ||
+            (winSock.connect == NULL) ||
+            (winSock.ioctlsocket == NULL) ||
+            (winSock.getsockopt == NULL) ||
+            (winSock.htons == NULL) ||
+            (winSock.inet_addr == NULL) ||
+            (winSock.inet_ntoa == NULL) ||
+            (winSock.listen == NULL) ||
+            (winSock.ntohs == NULL) ||
+            (winSock.recv == NULL) ||
+            (winSock.send == NULL) ||
+            (winSock.setsockopt == NULL) ||
+            (winSock.socket == NULL) ||
+            (winSock.gethostbyname == NULL) ||
+            (winSock.gethostbyaddr == NULL) ||
+            (winSock.gethostname == NULL) ||
+            (winSock.getpeername == NULL) ||
+            (winSock.getservbyname == NULL) ||
+            (winSock.getsockname == NULL) ||
+            (winSock.WSAStartup == NULL) ||
+            (winSock.WSACleanup == NULL) ||
+            (winSock.WSAGetLastError == NULL) ||
+            (winSock.WSAAsyncSelect == NULL)) {
+	goto unloadLibrary;
+    }
+    
+    /*
+     * Initialize the winsock library and check the version number.
+     */
+
+    if ((*winSock.WSAStartup)(WSA_VERSION_REQD, &wsaData) != 0) {
+	goto unloadLibrary;
+    }
+    if (wsaData.wVersion != WSA_VERSION_REQD) {
+	(*winSock.WSACleanup)();
+	goto unloadLibrary;
+    }
+
+    /*
+     * Create the async notification window with a new class.  We
+     * must create a new class to avoid a Windows 95 bug that causes
+     * us to get the wrong message number for socket events if the
+     * message window is a subclass of a static control.
+     */
+
+    class.style = 0;
+    class.cbClsExtra = 0;
+    class.cbWndExtra = 0;
+    class.hInstance = TclWinGetTclInstance();
+    class.hbrBackground = NULL;
+    class.lpszMenuName = NULL;
+    class.lpszClassName = "TclSocket";
+    class.lpfnWndProc = SocketProc;
+    class.hIcon = NULL;
+    class.hCursor = NULL;
+
+    if (RegisterClass(&class)) {
+	winSock.hwnd = CreateWindow("TclSocket", "TclSocket", WS_TILED, 0, 0,
+		0, 0, NULL, NULL, class.hInstance, NULL);
+    } else {
+	winSock.hwnd = NULL;
+    }
+    if (winSock.hwnd == NULL) {
+	TclWinConvertError(GetLastError());
+	(*winSock.WSACleanup)();
+	goto unloadLibrary;
+    }
+    Tcl_CreateEventSource(SocketSetupProc, SocketCheckProc, NULL);
+    return;
+
+unloadLibrary:
+    FreeLibrary(winSock.hInstance);
+    winSock.hInstance = NULL;
+    return;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SocketExitHandler --
+ *
+ *	Callback invoked during exit clean up to delete the socket
+ *	communication window and to release the WinSock DLL.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+    /* ARGSUSED */
+static void
+SocketExitHandler(clientData)
+    ClientData clientData;              /* Not used. */
+{
+    if (winSock.hInstance) {
+	DestroyWindow(winSock.hwnd);
+	UnregisterClass("TclSocket", TclWinGetTclInstance());
+	(*winSock.WSACleanup)();
+	FreeLibrary(winSock.hInstance);
+	winSock.hInstance = NULL;
+    }
+    Tcl_DeleteEventSource(SocketSetupProc, SocketCheckProc, NULL);
+    initialized = 0;
+    hostnameInitialized = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclHasSockets --
+ *
+ *	This function determines whether sockets are available on the
+ *	current system and returns an error in interp if they are not.
+ *	Note that interp may be NULL.
+ *
+ * Results:
+ *	Returns TCL_OK if the system supports sockets, or TCL_ERROR with
+ *	an error in interp.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclHasSockets(interp)
+    Tcl_Interp *interp;
+{
+    if (!initialized) {
+	InitSockets();
+    }
+    
+    if (winSock.hInstance != NULL) {
+	return TCL_OK;
+    }
+    if (interp != NULL) {
+	Tcl_AppendResult(interp, "sockets are not available on this system",
+		NULL);
+    }
+    return TCL_ERROR;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SocketSetupProc --
+ *
+ *	This procedure is invoked before Tcl_DoOneEvent blocks waiting
+ *	for an event.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Adjusts the block time if needed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+SocketSetupProc(data, flags)
+    ClientData data;		/* Not used. */
+    int flags;			/* Event flags as passed to Tcl_DoOneEvent. */
+{
+    SocketInfo *infoPtr;
+    Tcl_Time blockTime = { 0, 0 };
+
+    if (!(flags & TCL_FILE_EVENTS)) {
+	return;
+    }
+    
+    /*
+     * Check to see if there is a ready socket.  If so, poll.
+     */
+
+    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
+	if (infoPtr->readyEvents & infoPtr->watchEvents) {
+	    Tcl_SetMaxBlockTime(&blockTime);
+	    break;
+	}
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SocketCheckProc --
+ *
+ *	This procedure is called by Tcl_DoOneEvent to check the socket
+ *	event source for events. 
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	May queue an event.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+SocketCheckProc(data, flags)
+    ClientData data;		/* Not used. */
+    int flags;			/* Event flags as passed to Tcl_DoOneEvent. */
+{
+    SocketInfo *infoPtr;
+    SocketEvent *evPtr;
+
+    if (!(flags & TCL_FILE_EVENTS)) {
+	return;
+    }
+    
+    /*
+     * Queue events for any ready sockets that don't already have events
+     * queued (caused by persistent states that won't generate WinSock
+     * events).
+     */
+
+    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
+	if ((infoPtr->readyEvents & infoPtr->watchEvents)
+		&& !(infoPtr->flags & SOCKET_PENDING)) {
+	    infoPtr->flags |= SOCKET_PENDING;
+	    evPtr = (SocketEvent *) ckalloc(sizeof(SocketEvent));
+	    evPtr->header.proc = SocketEventProc;
+	    evPtr->socket = infoPtr->socket;
+	    Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
+	}
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SocketEventProc --
+ *
+ *	This procedure is called by Tcl_ServiceEvent when a socket event
+ *	reaches the front of the event queue.  This procedure is
+ *	responsible for notifying the generic channel code.
+ *
+ * Results:
+ *	Returns 1 if the event was handled, meaning it should be removed
+ *	from the queue.  Returns 0 if the event was not handled, meaning
+ *	it should stay on the queue.  The only time the event isn't
+ *	handled is if the TCL_FILE_EVENTS flag bit isn't set.
+ *
+ * Side effects:
+ *	Whatever the channel callback procedures do.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+SocketEventProc(evPtr, flags)
+    Tcl_Event *evPtr;		/* Event to service. */
+    int flags;			/* Flags that indicate what events to
+				 * handle, such as TCL_FILE_EVENTS. */
+{
+    SocketInfo *infoPtr;
+    SocketEvent *eventPtr = (SocketEvent *) evPtr;
+    int mask = 0;
+    u_long nBytes;
+    int status, events;
+
+    if (!(flags & TCL_FILE_EVENTS)) {
+	return 0;
+    }
+
+    /*
+     * Find the specified socket on the socket list.
+     */
+
+    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
+	if (infoPtr->socket == eventPtr->socket) {
+	    break;
+	}
+    }
+
+    /*
+     * Discard events that have gone stale.
+     */
+
+    if (!infoPtr) {
+	return 1;
+    }
+
+    infoPtr->flags &= ~SOCKET_PENDING;
+
+    /*
+     * Handle connection requests directly.
+     */
+
+    if (infoPtr->readyEvents & FD_ACCEPT) {
+	TcpAccept(infoPtr);
+	return 1;
+    }
+
+
+    /*
+     * Mask off unwanted events and compute the read/write mask so 
+     * we can notify the channel.
+     */
+
+    events = infoPtr->readyEvents & infoPtr->watchEvents;
+
+    if (events & FD_CLOSE) {
+	/*
+	 * If the socket was closed and the channel is still interested
+	 * in read events, then we need to ensure that we keep polling
+	 * for this event until someone does something with the channel.
+	 * Note that we do this before calling Tcl_NotifyChannel so we don't
+	 * have to watch out for the channel being deleted out from under
+	 * us.  This may cause a redundant trip through the event loop, but
+	 * it's simpler than trying to do unwind protection.
+	 */
+
+	Tcl_Time blockTime = { 0, 0 };
+	Tcl_SetMaxBlockTime(&blockTime);
+	mask |= TCL_READABLE;
+    } else if (events & FD_READ) {
+	/*
+	 * We must check to see if data is really available, since someone
+	 * could have consumed the data in the meantime.
+	 */
+
+	status = (*winSock.ioctlsocket)(infoPtr->socket, FIONREAD,
+		&nBytes);
+	if (status != SOCKET_ERROR && nBytes > 0) {
+	    mask |= TCL_READABLE;
+	} else {
+	    /*
+	     * We are in a strange state, probably because someone
+	     * besides Tcl is reading from this socket.  Try to
+	     * recover by clearing the read event.
+	     */
+	    
+	    infoPtr->readyEvents &= ~(FD_READ);
+
+ 	    /*
+ 	     * Re-issue WSAAsyncSelect() since we are gobbling up an
+ 	     * event,  without letting the reader do any I/O to re-enable
+	     * the notification.
+ 	     */
+
+ 	    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
+ 		    SOCKET_MESSAGE, infoPtr->selectEvents);
+	}
+    }
+    if (events & FD_WRITE) {
+	mask |= TCL_WRITABLE;
+    }
+
+    if (mask) {
+	Tcl_NotifyChannel(infoPtr->channel, mask);
+    }
+    return 1;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpBlockProc --
+ *
+ *	Sets a socket into blocking or non-blocking mode.
+ *
+ * Results:
+ *	0 if successful, errno if there was an error.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+TcpBlockProc(instanceData, mode)
+    ClientData	instanceData;	/* The socket to block/un-block. */
+    int mode;			/* TCL_MODE_BLOCKING or
+                                 * TCL_MODE_NONBLOCKING. */
+{
+    SocketInfo *infoPtr = (SocketInfo *) instanceData;
+
+    if (mode == TCL_MODE_NONBLOCKING) {
+	infoPtr->flags |= SOCKET_ASYNC;
+    } else {
+	infoPtr->flags &= ~(SOCKET_ASYNC);
+    }
+    return 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpCloseProc --
+ *
+ *	This procedure is called by the generic IO level to perform
+ *	channel type specific cleanup on a socket based channel
+ *	when the channel is closed.
+ *
+ * Results:
+ *	0 if successful, the value of errno if failed.
+ *
+ * Side effects:
+ *	Closes the socket.
+ *
+ *----------------------------------------------------------------------
+ */
+
+    /* ARGSUSED */
+static int
+TcpCloseProc(instanceData, interp)
+    ClientData instanceData;	/* The socket to close. */
+    Tcl_Interp *interp;		/* Unused. */
+{
+    SocketInfo *infoPtr = (SocketInfo *) instanceData;
+    SocketInfo **nextPtrPtr;
+    int errorCode = 0;
+
+    /*
+     * 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) {
+        
+	/*
+         * Clean up the OS socket handle.  The default Windows setting
+	 * for a socket is SO_DONTLINGER, which does a graceful shutdown
+	 * in the background.
+         */
+    
+        if ((*winSock.closesocket)(infoPtr->socket) == SOCKET_ERROR) {
+            TclWinConvertWSAError((*winSock.WSAGetLastError)());
+            errorCode = Tcl_GetErrno();
+        }
+    }
+
+    /*
+     * Remove the socket from socketList.
+     */
+
+    for (nextPtrPtr = &socketList; (*nextPtrPtr) != NULL;
+	 nextPtrPtr = &((*nextPtrPtr)->nextPtr)) {
+	if ((*nextPtrPtr) == infoPtr) {
+	    (*nextPtrPtr) = infoPtr->nextPtr;
+	    break;
+	}
+    }
+    ckfree((char *) infoPtr);
+    return errorCode;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * NewSocketInfo --
+ *
+ *	This function allocates and initializes a new SocketInfo
+ *	structure.
+ *
+ * Results:
+ *	Returns a newly allocated SocketInfo.
+ *
+ * Side effects:
+ *	Adds the socket to the global socket list.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static SocketInfo *
+NewSocketInfo(socket)
+    SOCKET socket;
+{
+    SocketInfo *infoPtr;
+
+    infoPtr = (SocketInfo *) ckalloc((unsigned) sizeof(SocketInfo));
+    infoPtr->socket = socket;
+    infoPtr->flags = 0;
+    infoPtr->watchEvents = 0;
+    infoPtr->readyEvents = 0;
+    infoPtr->selectEvents = 0;
+    infoPtr->acceptProc = NULL;
+    infoPtr->lastError = 0;
+    infoPtr->nextPtr = socketList;
+    socketList = infoPtr;
+    return infoPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * CreateSocket --
+ *
+ *	This function opens a new socket and initializes the
+ *	SocketInfo structure.
+ *
+ * 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.
+     */
+
+    (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);
+    
+    while (!(infoPtr->readyEvents & events)) {
+	if (infoPtr->flags & SOCKET_ASYNC) {
+	    if (!PeekMessage(&msg, winSock.hwnd, SOCKET_MESSAGE,
+		    SOCKET_MESSAGE, PM_REMOVE)) {
+		*errorCodePtr = EWOULDBLOCK;
+		result = 0;
+		break;
+	    }
+	} else {
+	    /*
+	     * Look for a socket event.  Note that we will be getting
+	     * events for all of Tcl's sockets, not just the one we wanted.
+	     */
+
+	    result = GetMessage(&msg, winSock.hwnd, SOCKET_MESSAGE,
+		    SOCKET_MESSAGE);
+	    if (result == -1) {
+		TclWinConvertError(GetLastError());
+		*errorCodePtr = Tcl_GetErrno();
+		result = 0;
+		break;
+	    }
+
+	    /*
+	     * I don't think we can get a WM_QUIT during a tight modal
+	     * loop, but just in case...
+	     */
+
+	    if (result == 0) {
+		panic("WaitForSocketEvent: Got WM_QUIT during modal loop!");
+	    }
+	}
+
+	/*
+	 * Dispatch the message and then check for an error on the socket.
+	 */
+
+	infoPtr->lastError = 0;
+	DispatchMessage(&msg);
+	if (infoPtr->lastError) {
+	    *errorCodePtr = infoPtr->lastError;
+	    result = 0;
+	    break;
+	}
+    }
+
+    (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 (markd@grizzly.com)
+ *
+ *----------------------------------------------------------------------
+ */
+
+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);
+
+    infoPtr = NewSocketInfo((SOCKET) sock);
+
+    /*
+     * Start watching for read/write events on the socket.
+     */
+
+    infoPtr->selectEvents = FD_READ | FD_CLOSE | FD_WRITE;
+    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
+	    SOCKET_MESSAGE, infoPtr->selectEvents);
+
+    sprintf(channelName, "sock%d", infoPtr->socket);
+    infoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
+	    (ClientData) infoPtr, (TCL_READABLE | TCL_WRITABLE));
+    Tcl_SetChannelOption(NULL, infoPtr->channel, "-translation", "auto crlf");
+    return infoPtr->channel;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_OpenTcpServer --
+ *
+ *	Opens a TCP server 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 server socket and creates a new channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_Channel
+Tcl_OpenTcpServer(interp, port, host, acceptProc, acceptProcData)
+    Tcl_Interp *interp;			/* For error reporting - may be
+                                         * NULL. */
+    int port;				/* Port number to open. */
+    char *host;				/* Name of local host. */
+    Tcl_TcpAcceptProc *acceptProc;	/* Callback for accepting connections
+                                         * from new clients. */
+    ClientData acceptProcData;		/* Data for the callback. */
+{
+    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, 1, NULL, 0, 0);
+    if (infoPtr == NULL) {
+	return NULL;
+    }
+
+    infoPtr->acceptProc = acceptProc;
+    infoPtr->acceptProcData = acceptProcData;
+
+    sprintf(channelName, "sock%d", infoPtr->socket);
+
+    infoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
+	    (ClientData) infoPtr, 0);
+    if (Tcl_SetChannelOption(interp, infoPtr->channel, "-eofchar", "")
+	    == TCL_ERROR) {
+        Tcl_Close((Tcl_Interp *) NULL, infoPtr->channel);
+        return (Tcl_Channel) NULL;
+    }
+
+    return infoPtr->channel;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpAccept --
+ *	Accept a TCP socket connection.  This is called by
+ *	SocketEventProc and it in turns calls the registered accept
+ *	procedure.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Invokes the accept proc which may invoke arbitrary Tcl code.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+TcpAccept(infoPtr)
+    SocketInfo *infoPtr;	/* Socket to accept. */
+{
+    SOCKET newSocket;
+    SocketInfo *newInfoPtr;
+    struct sockaddr_in addr;
+    int len;
+    char channelName[20];
+
+    /*
+     * Accept the incoming connection request.
+     */
+
+    len = sizeof(struct sockaddr_in);
+    newSocket = (*winSock.accept)(infoPtr->socket, (struct sockaddr *)&addr,
+	    &len);
+
+    /*
+     * Clear the ready mask so we can detect the next connection request.
+     * Note that connection requests are level triggered, so if there is
+     * a request already pending, a new event will be generated.
+     */
+
+    infoPtr->readyEvents &= ~(FD_ACCEPT);
+
+    if (newSocket == INVALID_SOCKET) {
+        return;
+    }
+
+    /*
+     * Add this socket to the global list of sockets.
+     */
+
+    newInfoPtr = NewSocketInfo(newSocket);
+
+    /*
+     * Select on read/write events and create the channel.
+     */
+
+    newInfoPtr->selectEvents = (FD_READ | FD_WRITE | FD_CLOSE);
+    (void) (*winSock.WSAAsyncSelect)(newInfoPtr->socket, winSock.hwnd, 
+	    SOCKET_MESSAGE, newInfoPtr->selectEvents);
+
+    sprintf(channelName, "sock%d", newInfoPtr->socket);
+    newInfoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
+	    (ClientData) newInfoPtr, (TCL_READABLE | TCL_WRITABLE));
+    if (Tcl_SetChannelOption(NULL, newInfoPtr->channel, "-translation",
+	    "auto crlf") == TCL_ERROR) {
+        Tcl_Close((Tcl_Interp *) NULL, newInfoPtr->channel);
+        return;
+    }
+    if (Tcl_SetChannelOption(NULL, newInfoPtr->channel, "-eofchar", "")
+	    == TCL_ERROR) {
+        Tcl_Close((Tcl_Interp *) NULL, newInfoPtr->channel);
+        return;
+    }
+
+    /*
+     * Invoke the accept callback procedure.
+     */
+
+    if (infoPtr->acceptProc != NULL) {
+	(infoPtr->acceptProc) (infoPtr->acceptProcData, newInfoPtr->channel,
+		(*winSock.inet_ntoa)(addr.sin_addr),
+		(*winSock.ntohs)(addr.sin_port));
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpInputProc --
+ *
+ *	This procedure is called by the generic IO level to read data from
+ *	a socket based channel.
+ *
+ * Results:
+ *	The number of bytes read or -1 on error.
+ *
+ * Side effects:
+ *	Consumes input from the socket.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+TcpInputProc(instanceData, buf, toRead, errorCodePtr)
+    ClientData instanceData;		/* The socket state. */
+    char *buf;				/* Where to store data. */
+    int toRead;				/* Maximum number of bytes to read. */
+    int *errorCodePtr;			/* Where to store error codes. */
+{
+    SocketInfo *infoPtr = (SocketInfo *) instanceData;
+    int bytesRead;
+    int error;
+    
+    *errorCodePtr = 0;
+
+    /*
+     * 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) {
+        *errorCodePtr = EFAULT;
+        return -1;
+    }
+
+    /*
+     * First check to see if EOF was already detected, to prevent
+     * calling the socket stack after the first time EOF is detected.
+     */
+
+    if (infoPtr->flags & SOCKET_EOF) {
+	return 0;
+    }
+
+    /*
+     * Check to see if the socket is connected before trying to read.
+     */
+
+    if ((infoPtr->flags & SOCKET_ASYNC_CONNECT)
+	    && ! WaitForSocketEvent(infoPtr,  FD_CONNECT, errorCodePtr)) {
+	return -1;
+    }
+    
+    /*
+     * No EOF, and it is connected, so try to read more from the socket.
+     * Note that we clear the FD_READ bit because read events are level
+     * triggered so a new event will be generated if there is still data
+     * available to be read.  We have to simulate blocking behavior here
+     * since we are always using non-blocking sockets.
+     */
+
+    while (1) {
+	if (infoPtr->readyEvents & (FD_CLOSE|FD_READ)) {
+	    bytesRead = (*winSock.recv)(infoPtr->socket, buf, toRead, 0);
+	    infoPtr->readyEvents &= ~(FD_READ);
+
+	    /*
+	     * Check for end-of-file condition or successful read.
+	     */
+
+	    if (bytesRead == 0) {
+		infoPtr->flags |= SOCKET_EOF;
+	    }
+	    if (bytesRead != SOCKET_ERROR) {
+		return bytesRead;
+	    }
+
+	    /*
+	     * If an error occurs after the FD_CLOSE has arrived,
+	     * then ignore the error and report an EOF.
+	     */
+
+	    if (infoPtr->readyEvents & FD_CLOSE) {
+		infoPtr->flags |= SOCKET_EOF;
+		return 0;
+	    }
+
+	    /*
+	     * Check for error condition or underflow in non-blocking case.
+	     */
+
+	    error = (*winSock.WSAGetLastError)();
+	    if ((infoPtr->flags & SOCKET_ASYNC) || (error != WSAEWOULDBLOCK)) {
+		TclWinConvertWSAError(error);
+		*errorCodePtr = Tcl_GetErrno();
+		return -1;
+	    }
+
+	} else if (infoPtr->flags & SOCKET_ASYNC) {
+	    *errorCodePtr = EWOULDBLOCK;
+	    return -1;
+	}
+
+	/*
+	 * In the blocking case, wait until the file becomes readable
+	 * or closed and try again.
+	 */
+
+	if (!WaitForSocketEvent(infoPtr, FD_READ|FD_CLOSE, errorCodePtr)) {
+	    return -1;
+	}
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpOutputProc --
+ *
+ *	This procedure is called by the generic IO level to write data
+ *	to a socket based channel.
+ *
+ * Results:
+ *	The number of bytes written or -1 on failure.
+ *
+ * Side effects:
+ *	Produces output on the socket.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+TcpOutputProc(instanceData, buf, toWrite, errorCodePtr)
+    ClientData instanceData;		/* The socket state. */
+    char *buf;				/* Where to get data. */
+    int toWrite;			/* Maximum number of bytes to write. */
+    int *errorCodePtr;			/* Where to store error codes. */
+{
+    SocketInfo *infoPtr = (SocketInfo *) instanceData;
+    int bytesWritten;
+    int error;
+
+    *errorCodePtr = 0;
+
+    /*
+     * 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) {
+        *errorCodePtr = EFAULT;
+        return -1;
+    }
+    
+    /*
+     * Check to see if the socket is connected before trying to write.
+     */
+    
+    if ((infoPtr->flags & SOCKET_ASYNC_CONNECT)
+	    && ! WaitForSocketEvent(infoPtr,  FD_CONNECT, errorCodePtr)) {
+	return -1;
+    }
+
+    while (1) {
+	bytesWritten = (*winSock.send)(infoPtr->socket, buf, toWrite, 0);
+	if (bytesWritten != SOCKET_ERROR) {
+	    /*
+	     * Since Windows won't generate a new write event until we hit
+	     * an overflow condition, we need to force the event loop to
+	     * poll until the condition changes.
+	     */
+
+	    if (infoPtr->watchEvents & FD_WRITE) {
+		Tcl_Time blockTime = { 0, 0 };
+		Tcl_SetMaxBlockTime(&blockTime);
+	    }		
+	    break;
+	}
+	
+	/*
+	 * Check for error condition or overflow.  In the event of overflow, we
+	 * need to clear the FD_WRITE flag so we can detect the next writable
+	 * event.  Note that Windows only sends a new writable event after a
+	 * send fails with WSAEWOULDBLOCK.
+	 */
+
+	error = (*winSock.WSAGetLastError)();
+	if (error == WSAEWOULDBLOCK) {
+	    infoPtr->readyEvents &= ~(FD_WRITE);
+	    if (infoPtr->flags & SOCKET_ASYNC) {
+		*errorCodePtr = EWOULDBLOCK;
+		return -1;
+	    } 
+	} else {
+	    TclWinConvertWSAError(error);
+	    *errorCodePtr = Tcl_GetErrno();
+	    return -1;
+	}
+
+	/*
+	 * In the blocking case, wait until the file becomes writable
+	 * or closed and try again.
+	 */
+
+	if (!WaitForSocketEvent(infoPtr, FD_WRITE|FD_CLOSE, errorCodePtr)) {
+	    return -1;
+	}
+    }
+
+    return bytesWritten;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * 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.
+ *
+ * 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. */
+{
+    SocketInfo *infoPtr;
+    struct sockaddr_in sockname;
+    struct sockaddr_in peername;
+    struct hostent *hostEntPtr;
+    SOCKET sock;
+    int size = sizeof(struct sockaddr_in);
+    size_t len = 0;
+    char buf[128];
+
+    /*
+     * 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) {
+	if (interp) {
+	    Tcl_AppendResult(interp, "winsock is not initialized", NULL);
+	}
+        return TCL_ERROR;
+    }
+    
+    infoPtr = (SocketInfo *) instanceData;
+    sock = (int) infoPtr->socket;
+    if (optionName != (char *) NULL) {
+        len = strlen(optionName);
+    }
+
+    if ((len == 0) ||
+            ((len > 1) && (optionName[1] == 'p') &&
+                    (strncmp(optionName, "-peername", len) == 0))) {
+        if ((*winSock.getpeername)(sock, (struct sockaddr *) &peername, &size)
+                == 0) {
+            if (len == 0) {
+                Tcl_DStringAppendElement(dsPtr, "-peername");
+                Tcl_DStringStartSublist(dsPtr);
+            }
+            Tcl_DStringAppendElement(dsPtr,
+                    (*winSock.inet_ntoa)(peername.sin_addr));
+            hostEntPtr = (*winSock.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,
+                        (*winSock.inet_ntoa)(peername.sin_addr));
+            }
+            sprintf(buf, "%d", (*winSock.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). {copied from unix/tclUnixChan.c}
+             */
+            if (len) {
+		TclWinConvertWSAError((*winSock.WSAGetLastError)());
+                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 ((*winSock.getsockname)(sock, (struct sockaddr *) &sockname, &size)
+                == 0) {
+            if (len == 0) {
+                Tcl_DStringAppendElement(dsPtr, "-sockname");
+                Tcl_DStringStartSublist(dsPtr);
+            }
+            Tcl_DStringAppendElement(dsPtr,
+                    (*winSock.inet_ntoa)(sockname.sin_addr));
+            hostEntPtr = (*winSock.gethostbyaddr)(
+                (char *) &(sockname.sin_addr), sizeof(peername.sin_addr),
+                AF_INET);
+            if (hostEntPtr != (struct hostent *) NULL) {
+                Tcl_DStringAppendElement(dsPtr, hostEntPtr->h_name);
+            } else {
+                Tcl_DStringAppendElement(dsPtr,
+                        (*winSock.inet_ntoa)(sockname.sin_addr));
+            }
+            sprintf(buf, "%d", (*winSock.ntohs)(sockname.sin_port));
+            Tcl_DStringAppendElement(dsPtr, buf);
+            if (len == 0) {
+                Tcl_DStringEndSublist(dsPtr);
+            } else {
+                return TCL_OK;
+            }
+        } else {
+	    if (interp) {
+		TclWinConvertWSAError((*winSock.WSAGetLastError)());
+		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 --
+ *
+ *	Informs the channel driver of the events that the generic
+ *	channel code wishes to receive on this socket.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	May cause the notifier to poll if any of the specified 
+ *	conditions are already true.
+ *
+ *----------------------------------------------------------------------
+ */
+
+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. */
+{
+    SocketInfo *infoPtr = (SocketInfo *) instanceData;
+    
+    /*
+     * Update the watch events mask.
+     */
+    
+    infoPtr->watchEvents = 0;
+    if (mask & TCL_READABLE) {
+	infoPtr->watchEvents |= (FD_READ|FD_CLOSE|FD_ACCEPT);
+    }
+    if (mask & TCL_WRITABLE) {
+	infoPtr->watchEvents |= (FD_WRITE);
+    }
+
+    /*
+     * If there are any conditions already set, then tell the notifier to poll
+     * rather than block.
+     */
+
+    if (infoPtr->readyEvents & infoPtr->watchEvents) {
+	Tcl_Time blockTime = { 0, 0 };
+	Tcl_SetMaxBlockTime(&blockTime);
+    }		
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpGetProc --
+ *
+ *	Called from Tcl_GetChannelFile to retrieve an OS handle from inside
+ *	a TCP socket based channel.
+ *
+ * Results:
+ *	Returns TCL_OK with the socket in handlePtr.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+TcpGetHandleProc(instanceData, direction, handlePtr)
+    ClientData instanceData;	/* The socket state. */
+    int direction;		/* Not used. */
+    ClientData *handlePtr;	/* Where to store the handle.  */
+{
+    SocketInfo *statePtr = (SocketInfo *) instanceData;
+
+    *handlePtr = (ClientData) statePtr->socket;
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SocketProc --
+ *
+ *	This function is called when WSAAsyncSelect has been used
+ *	to register interest in a socket event, and the event has
+ *	occurred.
+ *
+ * Results:
+ *	0 on success.
+ *
+ * Side effects:
+ *	The flags for the given socket are updated to reflect the
+ *	event that occured.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static LRESULT CALLBACK
+SocketProc(hwnd, message, wParam, lParam)
+    HWND hwnd;
+    UINT message;
+    WPARAM wParam;
+    LPARAM lParam;
+{
+    int event, error;
+    SOCKET socket;
+    SocketInfo *infoPtr;
+
+    if (message != SOCKET_MESSAGE) {
+	return DefWindowProc(hwnd, message, wParam, lParam);
+    }
+
+    event = WSAGETSELECTEVENT(lParam);
+    error = WSAGETSELECTERROR(lParam);
+    socket = (SOCKET) wParam;
+
+    /*
+     * Find the specified socket on the socket list and update its
+     * eventState flag.
+     */
+
+    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
+	if (infoPtr->socket == socket) {
+	    /*
+	     * Update the socket state.
+	     */
+
+	    if (event & FD_CLOSE) {
+		infoPtr->readyEvents &= ~(FD_WRITE|FD_ACCEPT);
+	    }
+	    if (event & FD_CONNECT) {
+		/*
+		 * The socket is now connected, so clear the async connect
+		 * flag.
+		 */
+
+		infoPtr->flags &= ~(SOCKET_ASYNC_CONNECT);
+
+		/*
+		 * Remember any error that occurred so we can report
+		 * connection failures.
+		 */
+
+		if (error != ERROR_SUCCESS) {
+		    TclWinConvertWSAError(error);
+		    infoPtr->lastError = Tcl_GetErrno();
+		}
+
+	    } 
+	    infoPtr->readyEvents |= event;
+	    break;
+	}
+    }
+
+    /*
+     * Flush the Tcl event queue before returning to the event loop.
+     */
+
+    Tcl_ServiceAll();
+
+    return 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_GetHostName --
+ *
+ *	Returns the name of the local host.
+ *
+ * Results:
+ *	A string containing the network name for this machine, or
+ *	an empty string if we can't figure out the name.  The caller 
+ *	must not modify or free this string.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+Tcl_GetHostName()
+{
+    DWORD length;
+    char *p;
+
+    if (hostnameInitialized) {
+        return hostname;
+    }
+
+    if (TclHasSockets(NULL) == TCL_OK) {
+	if ((*winSock.gethostname)(hostname, sizeof(hostname)) == 0) {
+	    hostnameInitialized = 1;
+	    return hostname;
+	}
+    }
+    length = sizeof(hostname);
+    if (GetComputerName(hostname, &length) != 0) {
+	for (p = hostname; *p != '\0'; p++) {
+	    if (isupper(*((unsigned char *) p))) {
+		*p = (char) tolower(*((unsigned char *) p));
+	    }
+	}
+    } else {
+	hostname[0] = '\0';
+    }
+    hostnameInitialized = 1;
+    return hostname;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclWinGetSockOpt, et al. --
+ *
+ *	These functions are wrappers that let us bind the WinSock
+ *	API dynamically so we can run on systems that don't have
+ *	the wsock32.dll.  We need wrappers for these interfaces
+ *	because they are called from the generic Tcl code.
+ *
+ * Results:
+ *	As defined for each function.
+ *
+ * Side effects:
+ *	As defined for each function.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int PASCAL FAR
+TclWinGetSockOpt(SOCKET s, int level, int optname, char FAR * optval,
+	int FAR *optlen)
+{
+    /*
+     * 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 SOCKET_ERROR;
+    }
+    
+    return (*winSock.getsockopt)(s, level, optname, optval, optlen);
+}
+
+int PASCAL FAR
+TclWinSetSockOpt(SOCKET s, int level, int optname, const char FAR * optval,
+	int optlen)
+{
+    /*
+     * 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 SOCKET_ERROR;
+    }
+
+    return (*winSock.setsockopt)(s, level, optname, optval, optlen);
+}
+
+u_short PASCAL FAR
+TclWinNToHS(u_short netshort)
+{
+    /*
+     * 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 (u_short) -1;
+    }
+
+    return (*winSock.ntohs)(netshort);
+}
+
+struct servent FAR * PASCAL FAR
+TclWinGetServByName(const char FAR * name, const char FAR * proto)
+{
+    /*
+     * 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 (struct servent FAR *) NULL;
+    }
+
+    return (*winSock.getservbyname)(name, proto);
+}