- FAQ - Winsock Errors

¿What is a Winsock Error..?

A Winsock (Windows Socket) error is an error that occurs in the
communications of two end points on the Internet.

¿What do the errors mean..?

A... The following is a list of possible Winsock error codes, along with their
extended explanations. Errors are listed in alphabetical order by error macro.

WSAEINTR
(10004)
Interrupted function call.
A blocking operation was interrupted by a call to WSACancelBlockingCall.

WSAEACCES
(10013)
Permission denied.
An attempt was made to access a socket in a way forbidden by its access
permissions. An example is using a broadcast address for sendto without
broadcast permission being set using setsockopt(SO_BROADCAST).

WSAEFAULT
(10014)
Bad address.
The system detected an invalid pointer address in attempting to use a pointer
argument of a call. This error occurs if an application passes an invalid
pointer value, or if the length of the buffer is too small. For instance, if the
length of an argument which is a struct sockaddr is smaller than sizeof(struct
sockaddr).

WSAEINVAL
(10022)
Invalid argument.
Some invalid argument was supplied (for example, specifying an invalid level to
the setsockopt function). In some instances, it also refers to the current state
of the socket - for instance, calling accept on a socket that is not listening.

WSAEMFILE
(10024)
Too many open files.
Too many open sockets. Each implementation may have a maximum number of socket
handles available, either globally, per process or per thread.

WSAEWOULDBLOCK
(10035)
Resource temporarily unavailable.
This error is returned from operations on non-blocking sockets that cannot be
completed immediately, for example recv when no data is queued to be read from
the socket. It is a non-fatal error, and the operation should be retried later.
It is normal for WSAEWOULDBLOCK to be reported as the result from calling
connecton a non-blocking SOCK_STREAM socket, since some time must elapse for the
connection to be established.

WSAEINPROGRESS
(10036)
Operation now in progress.
A blocking operation is currently executing. Windows Sockets only allows a
single blocking operation to be outstanding per task (or thread), and if any
other function call is made (whether or not it references that or any other
socket) the function fails with the WSAEINPROGRESS error.

WSAEALREADY
(10037)
Operation already in progress.
An operation was attempted on a non-blocking socket that already had an
operation in progress - i.e. calling connecta second time on a non-blocking
socket that is already connecting, or canceling an asynchronous request
(WSAAsyncGetXbyY) that has already been canceled or completed.

WSAENOTSOCK
(10038)
Socket operation on non-socket.
An operation was attempted on something that is not a socket. Either the socket
handle parameter did not reference a valid socket, or for select, a member of an
fd_set was not valid.

WSAEDESTADDRREQ
(10039)
Destination address required.
A required address was omitted from an operation on a socket. For example, this
error will be returned if sendtois called with the remote address of ADDR_ANY.

WSAEMSGSIZE
(10040)
Message too long.
A message sent on a datagram socket was larger than the internal message buffer
or some other network limit, or the buffer used to receive a datagram into was
smaller than the datagram itself.

WSAEPROTOTYPE
(10041)
Protocol wrong type for socket.
A protocol was specified in the socketfunction call that does not support the
semantics of the socket type requested. For example, the ARPA Internet UDP
protocol cannot be specified with a socket type of SOCK_STREAM.

WSAENOPROTOOPT
(10042)
Bad protocol option.
An unknown, invalid or unsupported option or level was specified in a getsockopt
or setsockoptcall.

WSAEPROTONOSUPPORT
(10043)
Protocol not supported.
The requested protocol has not been configured into the system, or no
implementation for it exists. For example, a socketcall requests a SOCK_DGRAM
socket, but specifies a stream protocol.

WSAESOCKTNOSUPPORT
(10044)
Socket type not supported.
The support for the specified socket type does not exist in this address family.
For example, the optional type SOCK_RAW might be selected in a socketcall, and
the implementation does not support SOCK_RAW sockets at all.

WSAEOPNOTSUPP
(10045)
Operation not supported.
The attempted operation is not supported for the type of object referenced.
Usually this occurs when a socket descriptor to a socket that cannot support
this operation, for example, trying to accept a connection on a datagram socket.

WSAEPFNOSUPPORT
(10046)
Protocol family not supported.
The protocol family has not been configured into the system or no implementation
for it exists. Has a slightly different meaning to WSAEAFNOSUPPORT, but is
interchangeable in most cases, and all Windows Sockets functions that return one
of these specify WSAEAFNOSUPPORT.

WSAEAFNOSUPPORT
(10047)
Address family not supported by protocol family.
An address incompatible with the requested protocol was used. All sockets are
created with an associated "address family" (i.e. AF_INET for Internet
Protocols) and a generic protocol type (i.e. SOCK_STREAM). This error will be
returned if an incorrect protocol is explicitly requested in the socket call, or
if an address of the wrong family is used for a socket, e.g. in sendto.

WSAEADDRINUSE
(10048)
Address already in use.
Only one usage of each socket address (protocol/IP address/port) is normally
permitted. This error occurs if an application attempts to bind a socket to an
IP address/port that has already been used for an existing socket, or a socket
that wasn't closed properly, or one that is still in the process of closing. For
server applications that need to bind multiple sockets to the same port number,
consider using setsockopt(SO_REUSEADDR). Client applications usually need not
call bind at all - connectwill choose an unused port automatically.

WSAEADDRNOTAVAIL
(10049)
Cannot assign requested address.
The requested address is not valid in its context. Normally results from an
attempt to bind to an address that is not valid for the local machine, or
connect/sendtoan address or port that is not valid for a remote machine (e.g.
port 0).

WSAENETDOWN
(10050)
Network is down.
A socket operation encountered a dead network. This could indicate a serious
failure of the network system (i.e. the protocol stack that the WinSock DLL runs
over), the network interface, or the local network itself.

WSAENETUNREACH
(10051)
Network is unreachable.
A socket operation was attempted to an unreachable network. This usually means
the local software knows no route to reach the remote host.

WSAENETRESET
(10052)
Network dropped connection on reset.
The host you were connected to crashed and rebooted. May also be returned by
setsockoptif an attempt is made to set SO_KEEPALIVE on a connection that has
already failed.

WSAECONNABORTED
(10053)
Software caused connection abort.
An established connection was aborted by the software in your host machine,
possibly due to a data transmission timeout or protocol error.

WSAECONNRESET
(10054)
Connection reset by peer.
A existing connection was forcibly closed by the remote host. This normally
results if the peer application on the remote host is suddenly stopped, the host
is rebooted, or the remote host used a "hard close" (see setsockopt for more
information on the SO_LINGERoption on the remote socket.)

WSAENOBUFS
(10055)
No buffer space available.
An operation on a socket could not be performed because the system lacked
sufficient buffer space or because a queue was full.

WSAEISCONN
(10056)
Socket is already connected.
A connect request was made on an already connected socket. Some implementations
also return this error if sendto is called on a connected SOCK_DGRAM socket (For
SOCK_STREAM sockets, the to parameter in sendtois ignored), although other
implementations treat this as a legal occurrence.

WSAENOTCONN
(10057)
Socket is not connected.
A request to send or receive data was disallowed because the socket is not
connected and (when sending on a datagram socket using sendto) no address was
supplied. Any other type of operation might also return this error - for
example, setsockoptsetting SO_KEEPALIVE if the connection has been reset.

WSAESHUTDOWN
(10058)
Cannot send after socket shutdown.
A request to send or receive data was disallowed because the socket had already
been shut down in that direction with a previous shutdown call. By calling
shutdowna partial close of a socket is requested, which is a signal that sending
or receiving or both has been discontinued.

WSAETIMEDOUT
(10060)
Connection timed out.
A connection attempt failed because the connected party did not properly respond
after a period of time, or established connection failed because connected host
has failed to respond.

WSAECONNREFUSED
(10061)
Connection refused.
No connection could be made because the target machine actively refused it. This
usually results from trying to connect to a service that is inactive on the
foreign host - i.e. one with no server application running.

WSAEHOSTDOWN
(10064)
Host is down.
A socket operation failed because the destination host was down. A socket
operation encountered a dead host. Networking activity on the local host has not
been initiated. These conditions are more likely to be indicated by the error
WSAETIMEDOUT.

WSAEHOSTUNREACH
(10065)
No route to host.
A socket operation was attempted to an unreachable host. See WSAENETUNREACH

WSAEPROCLIM
(10067)
Too many processes.
A Windows Sockets implementation may have a limit on the number of applications
that may use it simultaneously. WSAStartupmay fail with this error if the limit
has been reached.

WSASYSNOTREADY
(10091)
Network subsystem is unavailable.
This error is returned by WSAStartup if the Windows Sockets implementation
cannot function at this time because the underlying system it uses to provide
network services is currently unavailable. Users should check:
· that the appropriate Windows Sockets DLL file is in the current path,
· that they are not trying to use more than one Windows Sockets implementation
simultaneously. If there is more than one WINSOCK DLL on your system, be sure
the first one in the path is appropriate for the network subsystem currently
loaded.
· the Windows Sockets implementation documentation to be sure all necessary
components are currently installed and configured correctly.

WSAVERNOTSUPPORTED
(10092)
WINSOCK.DLL version out of range.
The current Windows Sockets implementation does not support the Windows Sockets
specification version requested by the application. Check that no old Windows
Sockets DLL files are being accessed.

WSANOTINITIALISED
(10093)
Successful WSAStartup not yet performed.
Either the application hasn't called WSAStartup or WSAStartup failed. The
application may be accessing a socket which the current active task does not own
(i.e. trying to share a socket between tasks), or WSACleanuphas been called too
many times.

WSAEDISCON
(10094)
Graceful shutdown in progress.
Returned by recv, WSARecvto indicate the remote party has initiated a graceful
shutdown sequence.

WSAHOST_NOT_FOUND
(11001)
Host not found.
No such host is known. The name is not an official hostname or alias, or it
cannot be found in the database(s) being queried. This error may also be
returned for protocol and service queries, and means the specified name could
not be found in the relevant database.

WSATRY_AGAIN
(11002)
Non-authoritative host not found.
This is usually a temporary error during hostname resolution and means that the
local server did not receive a response from an authoritative server. A retry at
some time later may be successful.

WSANO_RECOVERY
(11003)
This is a non-recoverable error.
This indicates some sort of non-recoverable error occurred during a database
lookup. This may be because the database files (e.g. BSD-compatible HOSTS,
SERVICES or PROTOCOLS files) could not be found, or a DNS request was returned
by the server with a severe error.

WSANO_DATA
(11004)
Valid name, no data record of requested type.
The requested name is valid and was found in the database, but it does not have
the correct associated data being resolved for. The usual example for this is a
hostname -> address translation attempt (using gethostbyname or
WSAAsyncGetHostByName) which uses the DNS (Domain Name Server), and an MX record
is returned but no A record - indicating the host itself exists, but is not
directly reachable.

WSA_INVALID_HANDLE
(OS dependent)
Specified event object handle is invalid.
An application attempts to use an event object, but the specified handle is not
valid.

WSA_INVALID_PARAMETER
(OS dependent)
One or more parameters are invalid.
An application used a Windows Sockets function which directly maps to a Win32
function. The Win32 function is indicating a problem with one or more
parameters.

WSAINVALIDPROCTABLE
(OS dependent)
Invalid procedure table from service provider.
A service provider returned a bogus proc table to WS2_32.DLL. (Usually caused by
one or more of the function pointers being NULL.)

WSAINVALIDPROVIDER
(OS dependent)
Invalid service provider version number.
A service provider returned a version number other than 2.0.

WSA_IO_PENDING
(OS dependent)
Overlapped operations will complete later.
The application has initiated an overlapped operation which cannot be completed
immediately. A completion indication will be given at a later time when the
operation has been completed.

WSA_IO_INCOMPLETE
(OS dependent)
Overlapped I/O event object not in signaled state.
The application has tried to determine the status of an overlapped operation
which is not yet completed. Applications that use WSAWaitForMultipleEventsin a
polling mode to determine when an overlapped operation has completed will get
this error code until the operation is complete.

WSA_NOT_ENOUGH_MEMORY
(OS dependent)
Insufficient memory available.
An application used a Windows Sockets function which directly maps to a Win32
function. The Win32 function is indicating a lack of required memory resources.

WSAPROVIDERFAILEDINIT
(OS dependent)
Unable to initialize a service provider.
Either a service provider's DLL could not be loaded (LoadLibrary failed) or the
provider's WSPStartup/NSPStartupfunction failed.

WSASYSCALLFAILURE
(OS dependent)
System call failure.
Returned when a system call that should never fail does. For example, if a call
to WaitForMultipleObjectsfails or one of the registry functions fails trying to
manipulate theprotocol/namespace catalogs.

WSA_OPERATION_ABORTED
(OS dependent)
Overlapped operation aborted.
An overlapped operation was canceled due to the closure of the socket, or the
execution of the SIO_FLUSH command in WSAIoctl.