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windows-nt-4.0/private/net/sockets/winsock2/wsp/ws2map/select.c

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/*++
Copyright (c) 1996 Microsoft Corporation
Module Name:
stubs.c
Abstract:
This module contains select routines for the Winsock 2 to
Winsock 1.1 Mapper Service Provider.
The following routines are exported by this module:
WSPAsyncSelect()
WSPEnumNetworkEvents()
WSPEventSelect()
WSPSelect()
SockDestroyAsyncWindow()
Author:
Keith Moore (keithmo) 29-May-1996
Revision History:
--*/
#include "precomp.h"
#pragma hdrstop
//
// The message we'll actually pass down to the WS1 DLL.
//
#define WM_MY_ASYNC_SELECT_MESSAGE 0x1234
//
// Window managment globals.
//
CHAR SockAsyncWindowClassName[] = "WinSock2MapperAsyncHelperWindow";
HWND SockAsyncWindowHandle;
//
// Forward procedure references.
//
LRESULT
CALLBACK
SockAsyncWindowProc(
HWND hwnd,
UINT msg,
WPARAM wParam,
LPARAM lParam
);
VOID
SockProcessAsyncSelectMessage(
WPARAM wParam,
LPARAM lParam
);
BOOL
SockCreateAsyncWindow(
VOID
);
INT
SockMapWS2FdSetToWS1(
PFD_SET WS2FdSet,
PFD_SET * WS1FdSet,
PULONG * TargetBuffer,
PSOCKET_INFORMATION * SocketInfo
);
INT
SockMapWS1FdSetToWS2(
PFD_SET WS1FdSet,
PFD_SET WS2FdSet
);
INT
WSPAPI
WSPAsyncSelect(
IN SOCKET s,
IN HWND hWnd,
IN unsigned int wMsg,
IN long lEvent,
OUT LPINT lpErrno
)
/*++
Routine Description:
This routine is used to request that the service provider send a Window
message to the client's window hWnd whenever it detects any of the
network events specified by the lEvent parameter. The service provider
should use the WPUPostMessage() function to post the message. The message
to be sent is specified by the wMsg parameter. The socket for which
notification is required is identified by s.
This routine automatically sets socket s to non-blocking mode, regardless
of the value of lEvent. See WSPIoctl() about how to set the socket back to
blocking mode.
The lEvent parameter is constructed by or'ing any of the values specified
in the following list.
Value Meaning
~~~~~ ~~~~~~~
FD_READ Issue notification of readiness for reading.
FD_WRITE Issue notification of readiness for writing.
FD_OOB Issue notification of the arrival of out-of-band data.
FD_ACCEPT Issue notification of incoming connections.
FD_CONNECT Issue notification of completed connection.
FD_CLOSE Issue notification of socket closure.
FD_QOS Issue notification of socket Quality of Service (QOS)
changes.
FD_GROUP_QOS Issue notification of socket group Quality of Service
(QOS) changes.
Invoking WSPAsyncSelect() for a socket cancels any previous
WSPAsyncSelect() or WSPEventSelect() for the same socket. For example,
to receive notification for both reading and writing, the WinSock SPI
client must call WSPAsyncSelect() with both FD_READ and FD_WRITE, as
follows:
rc = WSPAsyncSelect(s, hWnd, wMsg, FD_READ | FD_WRITE, &error);
It is not possible to specify different messages for different events. The
following code will not work; the second call will cancel the effects of
the first, and only FD_WRITE events will be reported with message wMsg2:
rc = WSPAsyncSelect(s, hWnd, wMsg1, FD_READ, &error);
rc = WSPAsyncSelect(s, hWnd, wMsg2, FD_WRITE, &error); // bad
To cancel all notification - i.e., to indicate that the service provider
should send no further messages related to network events on the socket -
lEvent will be set to zero.
rc = WSPAsyncSelect(s, hWnd, 0, 0, &error);
Since a WSPAccept()'ed socket has the same properties as the listening
socket used to accept it, any WSPAsyncSelect() events set for the
listening socket apply to the accepted socket. For example, if a listening
socket has WSPAsyncSelect() events FD_ACCEPT, FD_READ, and FD_WRITE, then
any socket accepted on that listening socket will also have FD_ACCEPT,
FD_READ, and FD_WRITE events with the same wMsg value used for messages.
If a different wMsg or events are desired, the WinSock SPI client must
call WSPAsyncSelect(), passing the accepted socket and the desired new
information.
When one of the nominated network events occurs on the specified socket s,
the service provider uses WPUPostMessage() to send message wMsg to the
WinSock SPI client's window hWnd. The wParam argument identifies the
socket on which a network event has occurred. The low word of lParam
specifies the network event that has occurred. The high word of lParam
contains any error code. The error code be any error as defined in
ws2spi.h.
The possible network event codes which may be indicated are as follows:
Value Meaning
~~~~~ ~~~~~~~
FD_READ Socket s ready for reading.
FD_WRITE Socket s ready for writing.
FD_OOB Out-of-band data ready for reading on socket s.
FD_ACCEPT Socket s ready for accepting a new incoming
connection.
FD_CONNECT Connection initiated on socket s completed.
FD_CLOSE Connection identified by socket s has been closed.
FD_QOS Quality of Service associated with socket s has
changed.
FD_GROUP_QOS Quality of Service associated with the socket group
to which s belongs has changed.
Although WSPAsyncSelect() can be called with interest in multiple events,
the service provider issues the same Windows message for each event.
A WinSock 2 provider shall not continually flood a WinSock SPI client
with messages for a particular network event. Having successfully posted
notification of a particular event to a WinSock SPI client window, no
further message(s) for that network event will be posted to the WinSock
SPI client window until the WinSock SPI client makes the function call
which implicitly reenables notification of that network event.
Event Re-enabling functions
~~~~~ ~~~~~~~~~~~~~~~~~~~~~
FD_READ WSPRecv() or WSPRecvFrom().
FD_WRITE WSPSend() or WSPSendTo().
FD_OOB WSPRecv() or WSPRecvFrom().
FD_ACCEPT WSPAccept() unless the error code returned is
WSATRY_AGAIN indicating that the condition
function returned CF_DEFER.
FD_CONNECT NONE
FD_CLOSE NONE
FD_QOS WSPIoctl() with SIO_GET_QOS
FD_GROUP_QOS WSPIoctl() with SIO_GET_GROUP_QOS
Any call to the reenabling routine, even one which fails, results in
reenabling of message posting for the relevant event.
For FD_READ, FD_OOB, and FD_ACCEPT events, message posting is "level-
triggered." This means that if the reenabling routine is called and the
relevant condition is still met after the call, a WSPAsyncSelect()
message is posted to the WinSock SPI client.
The FD_QOS and FD_GROUP_QOS events are considered edge triggered. A
message will be posted exactly once when a QOS change occurs. Further
messages will not be forthcoming until either the provider detects a
further change in QOS or the WinSock SPI client renegotiates the QOS
for the socket.
If any event has already happened when the WinSock SPI client calls
WSPAsyncSelect() or when the reenabling function is called, then a
message is posted as appropriate. For example, consider the following
sequence:
1. A WinSock SPI client calls WSPListen().
2. A connect request is received but not yet accepted.
3. The WinSock SPI client calls WSPAsyncSelect() specifying
that it wants to receive FD_ACCEPT messages for the socket.
Due to the persistence of events, the WinSock service provider
posts an FD_ACCEPT message immediately.
The FD_WRITE event is handled slightly differently. An FD_WRITE message
is posted when a socket is first connected with WSPConnect() (after
FD_CONNECT, if also registered) or accepted with WSPAccept(), and then
after a WSPSend() or WSPSendTo() fails with WSAEWOULDBLOCK and buffer
space becomes available. Therefore, a WinSock SPI client can assume that
sends are possible starting from the first FD_WRITE message and lasting
until a send returns WSAEWOULDBLOCK. After such a failure the WinSock SPI
client will be notified that sends are again possible with an FD_WRITE
message.
The FD_OOB event is used only when a socket is configured to receive
out-of-band data separately. If the socket is configured to receive
out-of-band data in-line, the out-of-band (expedited) data is treated as
normal data and the WinSock SPI client must register an interest in
FD_READ events, not FD_OOB events.
The error code in an FD_CLOSE message indicates whether the socket close
was graceful or abortive. If the error code is 0, then the close was
graceful; if the error code is WSAECONNRESET, then the socket's virtual
circuit was reset. This only applies to connection-oriented sockets such
as SOCK_STREAM.
The FD_CLOSE message is posted when a close indication is received for
the virtual circuit corresponding to the socket. In TCP terms, this means
that the FD_CLOSE is posted when the connection goes into the TIME WAIT
or CLOSE WAIT states. This results from the remote end performing a
WSPShutdown() on the send side or a WSPCloseSocket(). FD_CLOSE shall only
be posted after all data is read from a socket.
In the case of a graceful close, the service provider shall only send an
FD_CLOSE message to indicate virtual circuit closure after all the
received data has been read. It shall NOT send an FD_READ message to
indicate this condition.
The FD_QOS or FD_GROUP_QOS message is posted when any field in the flow
spec associated with socket s or the socket group that s belongs to has
changed, respectively. The service provider must update the QOS
information available to the client via WSPIoctl() with SIO_GET_QOS
and/or SIO_GET_GROUP_QOS.
Here is a summary of events and conditions for each asynchronous
notification message:
FD_READ
~~~~~~~
1. When WSPAsyncSelect() called, if there is data currently
available to receive.
2. When data arrives, if FD_READ not already posted.
3. after WSPRecv() or WSPRecvfrom() called (with or without
MSG_PEEK), if data is still available to receive.
N.B. When WSPSetSockOpt() SO_OOBINLINE is enabled "data" includes
both normal data and out-of-band (OOB) data in the instances noted
above.
FD_WRITE
~~~~~~~~
1. When WSPAsyncSelect() called, if a WSPSend() or WSPSendTo() is
possible.
2. After WSPConnect() or WSPAccept() called, when connection
established.
3. After WSPSend() or WSPSendTo() fail with WSAEWOULDBLOCK, when
WSPSend() or WSPSendTo() are likely to succeed.
4. After WSPBind() on a datagram socket.
FD_OOB
~~~~~~
Only valid when WSPSetSockOpt() SO_OOBINLINE is disabled (default).
1. When WSPAsyncSelect() called, if there is OOB data currently
available to receive with the MSG_OOB flag.
2. When OOB data arrives, if FD_OOB not already posted.
3. After WSPRecv() or WSPRecvfrom() called with or without MSG_OOB
flag, if OOB data is still available to receive.
FD_ACCEPT
~~~~~~~~~
1. When WSPAsyncSelect() called, if there is currently a connection
request available to accept.
2. When a connection request arrives, if FD_ACCEPT not already
posted.
3. After WSPAccept() called, if there is another connection request
available to accept.
FD_CONNECT
~~~~~~~~~~
1. When WSPAsyncSelect() called, if there is currently a connection
established.
2. After WSPConnect() called, when connection is established (even
when WSPConnect() succeeds immediately, as is typical with a
datagram socket)
FD_CLOSE
~~~~~~~~
Only valid on connection-oriented sockets (e.g. SOCK_STREAM)
1. When WSPAsyncSelect() called, if socket connection has been
closed.
2. After remote system initiated graceful close, when no data
currently available to receive (note: if data has been received
and is waiting to be read when the remote system initiates a
graceful close, the FD_CLOSE is not delivered until all pending
data has been read).
3. After local system initiates graceful close with WSPShutdown()
and remote system has responded with "End of Data" notification
(e.g. TCP FIN), when no data currently available to receive.
4. When remote system aborts connection (e.g. sent TCP RST), and
lParam will contain WSAECONNRESET error value.
N.B. FD_CLOSE is not posted after WSPClosesocket() is called.
FD_QOS
~~~~~~
1. When WSPAsyncSelect() called, if the QOS associated with the
socket has been changed.
2. After WSPIoctl() with SIO_GET_QOS called, when the QOS is
changed.
FD_GROUP_QOS
~~~~~~~~~~~~
1. When WSPAsyncSelect() called, if the group QOS associated with
the socket has been changed.
2. After WSPIoctl() with SIO_GET_GROUP_QOS called, when the group
QOS is changed.
Arguments:
s - A descriptor identifying the socket for which event notification is
required.
hWnd - A handle identifying the window which should receive a message
when a network event occurs.
wMsg - The message to be sent when a network event occurs.
lEvent - A bitmask which specifies a combination of network events in
which the WinSock SPI client is interested.
lpErrno - A pointer to the error code.
Return Value:
The return value is 0 if the WinSock SPI client's declaration of
interest in the network event set was successful. Otherwise the
value SOCKET_ERROR is returned, and a specific error code is
available in lpErrno.
--*/
{
PSOCKET_INFORMATION socketInfo;
INT err;
INT result;
HWND capturedWindowHandle;
UINT capturedWindowMessage;
SOCK_ENTER( "WSPAsyncSelect", (PVOID)s, (PVOID)hWnd, (PVOID)wMsg, (PVOID)lEvent );
SOCK_ASSERT( lpErrno != NULL );
err = SockEnterApi( TRUE, FALSE );
if( err != NO_ERROR ) {
SOCK_EXIT( "WSPAsyncSelect", SOCKET_ERROR, TRUE );
*lpErrno = err;
return SOCKET_ERROR;
}
//
// Setup locals so we know how to cleanup on exit.
//
socketInfo = NULL;
//
// Attempt to find the socket in our lookup table.
//
socketInfo = SockFindAndReferenceWS2Socket( s );
if( socketInfo == NULL || socketInfo->State == SocketStateClosing ) {
IF_DEBUG(SELECT) {
SOCK_PRINT((
"WSPAsyncSelect failed on %s handle: %lx\n",
socketInfo == NULL ? "unknown" : "closed",
s
));
}
if( socketInfo != NULL ) {
SockDereferenceSocket( socketInfo );
}
SOCK_EXIT( "WSPAsyncSelect", SOCKET_ERROR, TRUE );
*lpErrno = WSAENOTSOCK;
return SOCKET_ERROR;
}
//
// BUGBUG: Check for outstanding WSPEventSelect!
//
//
// Initialize the async window if necessary.
//
if( !SockCreateAsyncWindow() ) {
err = WSAENOBUFS; // SWAG
goto exit;
}
//
// Before we call the hooker, save the async select state in the
// socket.
//
capturedWindowHandle = socketInfo->WindowHandle;
capturedWindowMessage = socketInfo->WindowMessage;
socketInfo->WindowHandle = hWnd;
socketInfo->WindowMessage = wMsg;
//
// Let the hooker do its thang.
//
SockPreApiCallout();
result = socketInfo->Hooker->WSAAsyncSelect(
socketInfo->WS1Handle,
SockAsyncWindowHandle,
WM_MY_ASYNC_SELECT_MESSAGE,
lEvent
);
if( result == SOCKET_ERROR ) {
err = socketInfo->Hooker->WSAGetLastError();
SOCK_ASSERT( err != NO_ERROR );
SockPostApiCallout();
goto exit;
}
SockPostApiCallout();
//
// Success!
//
SOCK_ASSERT( err == NO_ERROR );
SOCK_ASSERT( result != SOCKET_ERROR );
exit:
if( err != NO_ERROR ) {
socketInfo->WindowHandle = capturedWindowHandle;
socketInfo->WindowMessage = capturedWindowMessage;
*lpErrno = err;
}
SockDereferenceSocket( socketInfo );
SOCK_EXIT( "WSPAsyncSelect", result, (BOOL)( result == SOCKET_ERROR ) );
return result;
} // WSPAsyncSelect
INT
WSPAPI
WSPEnumNetworkEvents(
IN SOCKET s,
IN WSAEVENT hEventObject,
OUT LPWSANETWORKEVENTS lpNetworkEvents,
OUT LPINT lpErrno
)
/*++
Routine Description:
This routine is used to report which network events have occurred for the
indicated socket since the last invocation of this routine. It is intended
for use in conjunction with WSPEventSelect(), which associates an event
object with one or more network events. Recording of network events
commences when WSPEventSelect() is called with a non-zero lNetworkEvents
parameter and remains in effect until another call is made to
WSPEventSelect() with the lNetworkEvents parameter set to zero, or until a
call is made to WSPAsyncSelect().
The socket's internal record of network events is copied to the structure
referenced by lpNetworkEvents, whereafter the internal network events
record is cleared. If hEventObject is non-null, the indicated event object
is also reset. The WinSock provider guarantees that the operations of
copying the network event record, clearing it and resetting any associated
event object are atomic, such that the next occurrence of a nominated
network event will cause the event object to become set. In the case of
this function returning SOCKET_ERROR, the associated event object is not
reset and the record of network events is not cleared.
The WSANETWORKEVENTS structure is defined as follows:
typedef struct _WSANETWORKEVENTS {
long lNetworkEvents;
int iErrorCodes[FD_MAX_EVENTS];
} WSANETWORKEVENTS, FAR * LPWSANETWORKEVENTS;
The lNetworkEvent field of the structure indicates which of the FD_XXX
network events have occurred. The iErrorCodes array is used to contain any
associated error codes, with array index corresponding to the position of
event bits in lNetworkEvents. The identifiers FD_READ_BIT, FD_WRITE_BIT,
etc. may be used to index the iErrorCodes array.
Arguments:
s - A descriptor identifying the socket.
hEventObject - An optional handle identifying an associated event
object to be reset.
lpNetworkEvents - A pointer to a WSANETWORKEVENTS struct which is
filled with a record of occurred network events and any associated
error codes.
lpErrno - A pointer to the error code.
Return Value:
The return value is 0 if the operation was successful. Otherwise the value
SOCKET_ERROR is returned, and a specific error number is available in
lpErrno.
--*/
{
return SOCKET_ERROR;
} // WSPEnumNetworkEvents
INT
WSPAPI
WSPEventSelect(
IN SOCKET s,
IN WSAEVENT hEventObject,
IN long lNetworkEvents,
OUT LPINT lpErrno
)
/*++
Routine Description:
This routine is used to specify an event object, hEventObject, to be
associated with the selected network events, lNetworkEvents. The socket
for which an event object is specified is identified by s. The event
object is set when any of the nominated network events occur.
WSPEventSelect() operates very similarly to WSPAsyncSelect(), the
difference being in the actions taken when a nominated network event
occurs. Whereas WSPAsyncSelect() causes a WinSock SPI client-specified
Windows message to be posted, WSPEventSelect() sets the associated event
object and records the occurrence of this event in an internal network
event record. A WinSock SPI client can use WSPEnumNetworkEvents() to
retrieve the contents of the internal network event record and thus
determine which of the nominated network events have occurred.
This routine automatically sets socket s to non-blocking mode, regardless
of the value of lNetworkEvents.
The lNetworkEvents parameter is constructed by OR'ing any of the values
specified in the following list.
Value Meaning
~~~~~ ~~~~~~~
FD_READ Issue notification of readiness for reading.
FD_WRITE Issue notification of readiness for writing.
FD_OOB Issue notification of the arrival of out-of-band data.
FD_ACCEPT Issue notification of incoming connections.
FD_CONNECT Issue notification of completed connection.
FD_CLOSE Issue notification of socket closure.
FD_QOS Issue notification of socket Quality of Service (QOS)
changes.
FD_GROUP_QOS Issue notification of socket group Quality of Service
(QOS) changes.
Issuing a WSPEventSelect() for a socket cancels any previous
WSPAsyncSelect() or WSPEventSelect() for the same socket and clears the
internal network event record. For example, to associate an event object
with both reading and writing network events, the WinSock SPI client must
call WSPEventSelect() with both FD_READ and FD_WRITE, as follows:
rc = WSPEventSelect(s, hEventObject, FD_READ | FD_WRITE);
It is not possible to specify different event objects for different
network events. The following code will not work; the second call will
cancel the effects of the first, and only FD_WRITE network event will be
associated with hEventObject2:
rc = WSPEventSelect(s, hEventObject1, FD_READ);
rc = WSPEventSelect(s, hEventObject2, FD_WRITE); //bad
To cancel the association and selection of network events on a socket,
lNetworkEvents should be set to zero, in which case the hEventObject
parameter will be ignored.
rc = WSPEventSelect(s, hEventObject, 0);
Closing a socket with WSPCloseSocket() also cancels the association and
selection of network events specified in WSPEventSelect() for the socket.
The WinSock SPI client, however, still must call WSACloseEvent() to
explicitly close the event object and free any resources.
Since a WSPAccept()'ed socket has the same properties as the listening
socket used to accept it, any WSPEventSelect() association and network
events selection set for the listening socket apply to the accepted socket.
For example, if a listening socket has WSPEventSelect() association of
hEventOject with FD_ACCEPT, FD_READ, and FD_WRITE, then any socket
accepted on that listening socket will also have FD_ACCEPT, FD_READ, and
FD_WRITE network events associated with the same hEventObject. If a
different hEventObject or network events are desired, the WinSock SPI
client should call WSPEventSelect(), passing the accepted socket and the
desired new information.
Having successfully recorded the occurrence of the network event and
signaled the associated event object, no further actions are taken for
that network event until the WinSock SPI client makes the function call
which implicitly reenables the setting of that network event and signaling
of the associated event object.
Event Re-enabling functions
~~~~~ ~~~~~~~~~~~~~~~~~~~~~
FD_READ WSPRecv() or WSPRecvFrom().
FD_WRITE WSPSend() or WSPSendTo().
FD_OOB WSPRecv() or WSPRecvFrom().
FD_ACCEPT WSPAccept() unless the error code returned is
WSATRY_AGAIN indicating that the condition
function returned CF_DEFER.
FD_CONNECT NONE
FD_CLOSE NONE
FD_QOS WSPIoctl() with SIO_GET_QOS
FD_GROUP_QOS WSPIoctl() with SIO_GET_GROUP_QOS
Any call to the reenabling routine, even one which fails, results in
reenabling of recording and signaling for the relevant network event and
event object, respectively.
For FD_READ, FD_OOB, and FD_ACCEPT network events, network event recording
and event object signaling are "level-triggered." This means that if the
reenabling routine is called and the relevant network condition is still
valid after the call, the network event is recorded and the associated
event object is signaled . This allows a WinSock SPI client to be event-
driven and not be concerned with the amount of data that arrives at any one
time. Consider the following sequence:
1. The service provider receives 100 bytes of data on socket s,
records the FD_READ network event and signals the associated
event object.
2. The WinSock SPI client issues WSPRecv( s, buffptr, 50, 0) to
read 50 bytes.
3. The service provider records the FD_READ network event and
signals the associated event object again since there is still
data to be read.
With these semantics, a WinSock SPI client need not read all available data
in response to an FD_READ network event --a single WSPRecv() in response to
each FD_READ network event is appropriate.
The FD_QOS and FD_GROUP_QOS events are considered edge triggered. A message
will be posted exactly once when a QOS change occurs. Further indications
will not be issued until either the service provider detects a further
change in QOS or the WinSock SPI client renegotiates the QOS for the
socket.
If a network event has already happened when the WinSock SPI client calls
WSPEventSelect() or when the reenabling function is called, then a network
event is recorded and the associated event object is signaled as
appropriate. For example, consider the following sequence:
1. A WinSock SPI client calls WSPListen().
2. A connect request is received but not yet accepted.
3. The WinSock SPI client calls WSPEventSelect() specifying that
it is interested in the FD_ACCEPT network event for the socket.
The service provider records the FD_ACCEPT network event and
signals the associated event object immediately.
The FD_WRITE network event is handled slightly differently. An FD_WRITE
network event is recorded when a socket is first connected with
WSPConnect() or accepted with WSPAccept(), and then after a WSPSend() or
WSPSendTo() fails with WSAEWOULDBLOCK and buffer space becomes available.
Therefore, a WinSock SPI client can assume that sends are possible
starting from the first FD_WRITE network event setting and lasting until
a send returns WSAEWOULDBLOCK. After such a failure the WinSock SPI client
will find out that sends are again possible when an FD_WRITE network event
is recorded and the associated event object is signaled.
The FD_OOB network event is used only when a socket is configured to
receive out-of-band data separately. If the socket is configured to receive
out-of-band data in-line, the out-of-band (expedited) data is treated as
normal data and the WinSock SPI client should register an interest in, and
will get, FD_READ network event, not FD_OOB network event. A WinSock SPI
client may set or inspect the way in which out-of-band data is to be
handled by using WSPSetSockOpt() or WSPGetSockOpt() for the SO_OOBINLINE
option.
The error code in an FD_CLOSE network event indicates whether the socket
close was graceful or abortive. If the error code is 0, then the close was
graceful; if the error code is WSAECONNRESET, then the socket's virtual
circuit was reset. This only applies to connection-oriented sockets such
as SOCK_STREAM.
The FD_CLOSE network event is recorded when a close indication is received
for the virtual circuit corresponding to the socket. In TCP terms, this
means that the FD_CLOSE is recorded when the connection goes into the
FIN WAIT or CLOSE WAIT states. This results from the remote end performing
a WSPShutdown() on the send side or a WSPCloseSocket().
Service providers shall record ONLY an FD_CLOSE network event to indicate
closure of a virtual circuit, they shall NOT record an FD_READ network
event to indicate this condition.
The FD_QOS or FD_GROUP_QOS network event is recorded when any field in the
flow spec associated with socket s or the socket group that s belongs to
has changed, respectively. This change must be made available to WinSock
SPI clients via the WSPIoctl() function with SIO_GET_QOS and/or
SIO_GET_GROUP_QOS to retrieve the current QOS for socket s or for the
socket group s belongs to, respectively.
Arguments:
s - A descriptor identifying the socket.
hEventObject - A handle identifying the event object to be associated
with the supplied set of network events.
lNetworkEvents - A bitmask which specifies the combination of network
events in which the WinSock SPI client has interest.
lpErrno - A pointer to the error code.
Return Value:
The return value is 0 if the WinSock SPI client's specification of the
network events and the associated event object was successful.
Otherwise the value SOCKET_ERROR is returned, and a specific error
number is available in lpErrno.
--*/
{
return SOCKET_ERROR;
} // WSPEventSelect
INT
WSPAPI
WSPSelect(
IN int nfds,
IN OUT fd_set FAR * readfds,
IN OUT fd_set FAR * writefds,
IN OUT fd_set FAR * exceptfds,
IN const struct timeval FAR * timeout,
OUT LPINT lpErrno
)
/*++
Routine Description:
This routine is used to determine the status of one or more sockets. For
each socket, the caller may request information on read, write or error
status. The set of sockets for which a given status is requested is
indicated by an fd_set structure. All entries in an fd_set correspond to
sockets created by the service provider. Upon return, the structures are
updated to reflect the subset of these sockets which meet the specified
condition, and WSPSelect() returns the total number of sockets meeting the
conditions. A set of macros is provided for manipulating an fd_set. These
macros are compatible with those used in the Berkeley software, but the
underlying representation is completely different.
The parameter readfds identifies those sockets which are to be checked for
readability. If the socket is currently WSPListen()ing, it will be marked
as readable if an incoming connection request has been received, so that a
WSPAccept() is guaranteed to complete without blocking. For other sockets,
readability means that queued data is available for reading so that a
WSPRecv() or WSPRecvfrom() is guaranteed not to block.
For connection-oriented sockets, readability may also indicate that a close
request has been received from the peer. If the virtual circuit was
closed gracefully, then a WSPRecv() will return immediately with 0 bytes
read. If the virtual circuit was reset, then a WSPRecv() will complete
immediately with an error code, such as WSAECONNRESET. The presence of
out-of-band data will be checked if the socket option SO_OOBINLINE has
been enabled (see WSPSetSockOpt()).
The parameter writefds identifies those sockets which are to be checked for
writability. If a socket is WSPConnect()ing, writability means that the
connection establishment successfully completed. If the socket is not in
the process of WSPConnect()ing, writability means that a WSPSend() or
WSPSendTo() are guaranteed to succeed. However, they may block on a
blocking socket if the len exceeds the amount of outgoing system buffer
space available.. (It is not specified how long these guarantees can be
assumed to be valid, particularly in a multithreaded environment.)
The parameter exceptfds identifies those sockets which are to be checked
for the presence of out-of-band data or any exceptional error conditions.
Note that out-of-band data will only be reported in this way if the option
SO_OOBINLINE is FALSE. If a socket is WSPConnect()ing (non-blocking),
failure of the connect attempt is indicated in exceptfds.
Any two of readfds, writefds, or exceptfds may be given as NULL if no
descriptors are to be checked for the condition of interest. At least one
must be non-NULL, and any non- NULL descriptor set must contain at least
one socket descriptor.
A socket will be identified in a particular set when WSPSelect() returns
if:
readfds
~~~~~~~
If WSPListen()ing, a connection is pending, WSPAccept()
will succeed.
Data is available for reading (includes OOB data if
SO_OOBINLINE is enabled).
Connection has been closed/reset/aborted.
writefds
~~~~~~~~
If WSPConnect()ing (non-blocking), connection has succeeded.
Data may be sent.
exceptfds
~~~~~~~~~
If WSPConnect()ing (non-blocking), connection attempt failed.
OOB data is available for reading (only if SO_OOBINLINE is
disabled).
Three macros and one upcall function are defined in the header file
ws2spi.h for manipulating and checking the descriptor sets. The variable
FD_SETSIZE determines the maximum number of descriptors in a set. (The
default value of FD_SETSIZE is 64, which may be modified by #defining
FD_SETSIZE to another value before #including ws2spi.h.) Internally,
socket handles in a fd_set are not represented as bit flags as in Berkeley
Unix. Their data representation is opaque. Use of these macros will
maintain software portability between different socket environments. The
macros to manipulate and check fd_set contents are:
FD_CLR(s, *set) Removes the descriptor s from set.
FD_SET(s, *set) Adds descriptor s to set.
FD_ZERO(*set) Initializes the set to the NULL set.
The upcall function used to check the membership is:
int WPUFDIsSet ( SOCKET s, FD_SET FAR * set );
which will return nonzero if s is a member of the set, or zero otherwise.
The parameter timeout controls how long the WSPSelect() may take to
complete. If timeout is a null pointer, WSPSelect() will block indefinitely
until at least one descriptor meets the specified criteria. Otherwise,
timeout points to a struct timeval which specifies the maximum time that
WSPSelect() should wait before returning. When WSPSelect() returns, the
contents of the struct timeval are not altered. If the timeval is
initialized to {0, 0}, WSPSelect() will return immediately; this is used
to "poll" the state of the selected sockets. If this is the case, then the
WSPSelect() call is considered nonblocking and the standard assumptions for
nonblocking calls apply. For example, the blocking hook will not be called,
and the WinSock provider will not yield.
WSPSelect() has no effect on the persistence of socket events registered
with WSPAsyncSelect() or WSPEventSelect().
Arguments:
nfds - This argument is ignored and included only for the sake of
compatibility.
readfds - An optional pointer to a set of sockets to be checked for
readability.
writefds - An optional pointer to a set of sockets to be checked for
writability
exceptfds - An optional pointer to a set of sockets to be checked for
errors.
timeout - The maximum time for WSPSelect() to wait, or NULL for a
blocking operation.
lpErrno - A pointer to the error code.
Return Value:
WSPSelect() returns the total number of descriptors which are ready and
contained in the fd_set structures, or SOCKET_ERROR if an error
occurred. If the return value is SOCKET_ERROR, a specific error code
is available in lpErrno.
--*/
{
PSOCKET_INFORMATION socketInfo;
INT err;
INT result;
UINT fdsetCount;
UINT socketCount;
UINT i;
PFD_SET ws1ReadFds;
PFD_SET ws1WriteFds;
PFD_SET ws1ExceptFds;
PVOID fdsetBuffer;
PULONG fdsetBufferScan;
ULONG fdsetBufferLength;
SOCK_ENTER( "WSPSelect", (PVOID)nfds, (PVOID)readfds, (PVOID)writefds, (PVOID)exceptfds );
SOCK_ASSERT( lpErrno != NULL );
err = SockEnterApi( TRUE, FALSE );
if( err != NO_ERROR ) {
SOCK_EXIT( "WSPSelect", SOCKET_ERROR, TRUE );
*lpErrno = err;
return SOCKET_ERROR;
}
//
// Setup locals so we know how to cleanup on exit.
//
fdsetCount = 0;
socketCount = 0;
ws1ReadFds = NULL;
ws1WriteFds = NULL;
ws1ExceptFds = NULL;
fdsetBuffer = NULL;
socketInfo = NULL;
//
// Count the number of FD_SETs and sockets in those sets.
//
if( readfds != NULL ) {
fdsetCount++;
socketCount += readfds->fd_count;
}
if( writefds != NULL ) {
fdsetCount++;
socketCount += writefds->fd_count;
}
if( exceptfds != NULL ) {
fdsetCount++;
socketCount += exceptfds->fd_count;
}
//
// Bail if there's no sets or no sockets.
//
if( fdsetCount == 0 || socketCount == 0 ) {
SOCK_EXIT( "WSPSelect", 0, FALSE );
return 0;
}
//
// Allocate a buffer to hold *all* of the mapped FD_SETs.
//
fdsetBufferLength = ( fdsetCount * sizeof(UINT) ) +
( socketCount * sizeof(SOCKET) );
fdsetBuffer = SOCK_ALLOCATE_HEAP( fdsetBufferLength );
if( fdsetBuffer == NULL ) {
SOCK_EXIT( "WSPSelect", SOCKET_ERROR, TRUE );
*lpErrno = WSAENOBUFS;
return SOCKET_ERROR;
}
RtlZeroMemory(
fdsetBuffer,
fdsetBufferLength
);
//
// Acquire the global lock. Any failure from this point must release
// the lock before returning.
//
//
// Build the mapped FD_SETs.
//
fdsetBufferScan = fdsetBuffer;
if( readfds != NULL ) {
err = SockMapWS2FdSetToWS1(
readfds,
&ws1ReadFds,
&fdsetBufferScan,
&socketInfo
);
if( err != NO_ERROR ) {
goto exit;
}
}
if( writefds != NULL ) {
err = SockMapWS2FdSetToWS1(
writefds,
&ws1WriteFds,
&fdsetBufferScan,
&socketInfo
);
if( err != NO_ERROR ) {
goto exit;
}
}
if( exceptfds != NULL ) {
err = SockMapWS2FdSetToWS1(
exceptfds,
&ws1ExceptFds,
&fdsetBufferScan,
&socketInfo
);
if( err != NO_ERROR ) {
goto exit;
}
}
SOCK_ASSERT( socketInfo != NULL );
//
// Now that we've got the sets mapped, we can let the hooker do
// its thang.
//
SockPrepareForBlockingHook( socketInfo );
SockPreApiCallout();
result = socketInfo->Hooker->select(
fdsetCount,
ws1ReadFds,
ws1WriteFds,
ws1ExceptFds,
timeout
);
if( result == SOCKET_ERROR ) {
err = socketInfo->Hooker->WSAGetLastError();
SOCK_ASSERT( err != NO_ERROR );
SockPostApiCallout();
goto exit;
}
SockPostApiCallout();
//
// Now, map the WS1 FD_SETs back to WS2 FD_Sets.
//
result = 0;
if( ws1ReadFds != NULL ) {
SOCK_ASSERT( readfds != NULL );
result += SockMapWS1FdSetToWS2(
ws1ReadFds,
readfds
);
}
if( ws1WriteFds != NULL ) {
SOCK_ASSERT( writefds != NULL );
result += SockMapWS1FdSetToWS2(
ws1WriteFds,
writefds
);
}
if( ws1ExceptFds != NULL ) {
SOCK_ASSERT( exceptfds != NULL );
result += SockMapWS1FdSetToWS2(
ws1ExceptFds,
exceptfds
);
}
//
// Success!
//
exit:
if( err != NO_ERROR ) {
*lpErrno = err;
result = SOCKET_ERROR;
}
if( fdsetBuffer != NULL ) {
SOCK_FREE_HEAP( fdsetBuffer );
}
if( socketInfo != NULL ) {
SockDereferenceSocket( socketInfo );
}
SOCK_EXIT( "WSPSelect", result, (BOOL)( result == SOCKET_ERROR ) );
return result;
} // WSPSelect
BOOL
SockCreateAsyncWindow(
VOID
)
/*++
Routine Description:
This routine creates the async window.
Arguments:
None.
Return Value:
BOOL - TRUE if the window was created successfully, FALSE otherwise.
--*/
{
WNDCLASS WndClass;
//
// First ensure that the window hasn't already been created.
//
if( SockAsyncWindowHandle != NULL ) {
return TRUE;
}
SockAcquireGlobalLock();
if( SockAsyncWindowHandle != NULL ) {
SockReleaseGlobalLock();
return TRUE;
}
//
// Register the window class.
//
WndClass.style = 0;
WndClass.lpfnWndProc = SockAsyncWindowProc;
WndClass.cbClsExtra = 0;
WndClass.cbWndExtra = 0;
WndClass.hInstance = NULL;
WndClass.hIcon = NULL;
WndClass.hCursor = NULL;
WndClass.hbrBackground = NULL;
WndClass.lpszMenuName = NULL;
WndClass.lpszClassName = SockAsyncWindowClassName;
if( !RegisterClass( &WndClass ) ) {
SOCK_PRINT((
"SockCreateAsyncWindow: cannot register class\n"
));
SockReleaseGlobalLock();
return FALSE;
}
//
// Create the window.
//
SockAsyncWindowHandle = CreateWindow(
SockAsyncWindowClassName,
"",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
NULL,
NULL
);
if( SockAsyncWindowHandle == NULL ) {
SOCK_PRINT((
"SockCreateAsyncWindow: cannot create window\n"
));
SockReleaseGlobalLock();
return FALSE;
}
IF_DEBUG(SELECT) {
SOCK_PRINT((
"SockCreateAsyncWindow: created %08lX\n",
SockAsyncWindowHandle
));
}
ShowWindow( SockAsyncWindowHandle, SW_HIDE );
UpdateWindow( SockAsyncWindowHandle );
//
// Success!
//
SockReleaseGlobalLock();
return TRUE;
} // SockCreateAsyncWindow
VOID
SockDestroyAsyncWindow(
VOID
)
/*++
Routine Description:
This routine destroys the async window.
Arguments:
None.
Return Value:
None.
--*/
{
SockAcquireGlobalLock();
if( SockAsyncWindowHandle != NULL ) {
IF_DEBUG(SELECT) {
SOCK_PRINT((
"SockDestroyAsyncWindow: destroying %08lX\n",
SockAsyncWindowHandle
));
}
SOCK_REQUIRE( DestroyWindow( SockAsyncWindowHandle ) );
SockAsyncWindowHandle = NULL;
}
SockReleaseGlobalLock();
} // SockDestroyAsyncWindow
LRESULT
CALLBACK
SockAsyncWindowProc(
HWND hwnd,
UINT msg,
WPARAM wParam,
LPARAM lParam
)
{
LRESULT Result;
Result = 0;
switch( msg ) {
case WM_DESTROY :
PostQuitMessage( 0 );
break;
case WM_MY_ASYNC_SELECT_MESSAGE :
SockProcessAsyncSelectMessage(
wParam,
lParam
);
default :
Result = DefWindowProc( hwnd, msg, wParam, lParam );
break;
}
return Result;
} // SockAsyncWindowProc
VOID
SockProcessAsyncSelectMessage(
WPARAM wParam,
LPARAM lParam
)
{
PSOCKET_INFORMATION socketInfo;
//
// See if we can map the WS1 handle to our socket info structure.
// If we can't, it's probably due to a race condition between the
// application and the WS1 DLL, so we'll just eat the message.
//
socketInfo = SockFindAndReferenceWS1Socket( (SOCKET)wParam );
if( socketInfo != NULL ) {
//
// Post the message to the application.
//
PostMessage(
socketInfo->WindowHandle,
socketInfo->WindowMessage,
(WPARAM)socketInfo->WS2Handle,
lParam
);
SockDereferenceSocket( socketInfo );
}
} // SockProcessAsyncSelectMessage
INT
SockMapWS2FdSetToWS1(
PFD_SET WS2FdSet,
PFD_SET * WS1FdSet,
PULONG * TargetBuffer,
PSOCKET_INFORMATION * SocketInfo
)
{
PSOCKET_INFORMATION socketInfo;
PSOCKET_INFORMATION returnedSocketInfo;
PFD_SET fdSet;
PULONG bufferScan;
UINT i;
INT err;
//
// Sanity check.
//
SOCK_ASSERT( WS2FdSet != NULL );
SOCK_ASSERT( WS1FdSet != NULL );
SOCK_ASSERT( TargetBuffer != NULL );
SOCK_ASSERT( SocketInfo != NULL );
//
// Grab the starting location for the mapped FD_SET.
//
bufferScan = *TargetBuffer;
fdSet = (PFD_SET)bufferScan;
returnedSocketInfo = *SocketInfo;
//
// Set the mapped count.
//
*bufferScan++ = WS2FdSet->fd_count;
//
// Scan the incoming array and map the WS2 handles to WS1 handles.
//
for( i = 0 ; i < WS2FdSet->fd_count ; i++ ) {
socketInfo = SockFindAndReferenceWS2Socket( WS2FdSet->fd_array[i] );
if( socketInfo == NULL || socketInfo->State == SocketStateClosing ) {
IF_DEBUG(SELECT) {
SOCK_PRINT((
"SockMapWS2FdSetToWS1: failed on %s handle: %lx\n",
socketInfo == NULL ? "unknown" : "closed",
fdSet->fd_array[i]
));
}
if( socketInfo != NULL ) {
SockDereferenceSocket( socketInfo );
}
return WSAENOTSOCK;
}
//
// Save the WS1 handle in the mapped FD_SET.
//
*bufferScan++ = socketInfo->WS1Handle;
//
// This is kind of a hack. The caller (WSPSelect) needs the
// PSOCKET_INFORMATION structure for any one socket in any of
// the FD_SETs. If we have not yet returned a PSOCKET_INFORMATION
// structure to the caller, we'll pass it the current one and
// *not* dereference it. Otherwise (we've already passed one back)
// we'll dereference it ourselves.
//
if( returnedSocketInfo == NULL ) {
returnedSocketInfo = socketInfo;
} else {
SockDereferenceSocket( socketInfo );
}
}
//
// Return the pointers back to the caller.
//
*WS1FdSet = fdSet;
*TargetBuffer = bufferScan;
*SocketInfo = returnedSocketInfo;
return NO_ERROR;
} // SockMapWS2FdSetToWS1
INT
SockMapWS1FdSetToWS2(
PFD_SET WS1FdSet,
PFD_SET WS2FdSet
)
{
PSOCKET_INFORMATION socketInfo;
UINT i, j;
//
// Sanity check.
//
SOCK_ASSERT( WS2FdSet != NULL );
SOCK_ASSERT( WS1FdSet != NULL );
//
// Move the count over.
//
WS2FdSet->fd_count = WS1FdSet->fd_count;
//
// Map the sockets over.
//
for( i = 0, j = 0 ; i < WS1FdSet->fd_count ; i++ ) {
//
// Try to find the info for this WS1 socket. If we can't,
// just remove it from the list.
//
socketInfo = SockFindAndReferenceWS1Socket( WS1FdSet->fd_array[i] );
if( socketInfo == NULL || socketInfo->State == SocketStateClosing ) {
WS2FdSet->fd_count--;
if( socketInfo != NULL ) {
SockDereferenceSocket( socketInfo );
}
} else {
WS2FdSet->fd_array[j++] = socketInfo->WS2Handle;
SockDereferenceSocket( socketInfo );
}
}
return j;
} // SockMapWS1FdSetToWS2