Winsock functions

The following list provides concise descriptions of each Winsock function. For additional information on any function, click the function name.

Function	Description
accept	Permits an incoming connection attempt on a socket.
AcceptEx	Accepts a new connection, returns the local and remote address, and receives the first block of data sent by the client application.
bind	Associates a local address with a socket.
closesocket	Closes an existing socket.
connect	Establishes a connection to a specified socket.
ConnectEx	Establishes a connection to a specified socket, and optionally sends data once the connection is established. Only supported on connection-oriented sockets.
DisconnectEx	Closes a connection on a socket, and allows the socket handle to be reused.
EnumProtocols	Retrieves information about a specified set of network protocols that are active on a local host.
freeaddrinfo	Frees address information that the getaddrinfo function dynamically allocates in addrinfo structures.
FreeAddrInfoEx	Frees address information that the GetAddrInfoEx function dynamically allocates in addrinfoex structures.
FreeAddrInfoW	Frees address information that the GetAddrInfoW function dynamically allocates in addrinfoW structures.
gai_strerror	Assists in printing error messages based on the EAI_* errors returned by the getaddrinfo function.
GetAcceptExSockaddrs	Parses the data obtained from a call to the AcceptEx function.
GetAddressByName	Queries a namespace, or a set of default namespaces, to retrieve network address information for a specified network service. This process is known as service name resolution. A network service can also use the function to obtain local address information that it can use with the bind function.
getaddrinfo	Provides protocol-independent translation from an ANSI host name to an address.
GetAddrInfoEx	Provides protocol-independent name resolution with additional parameters to qualify which name space providers should handle the request.
GetAddrInfoExCancel	Cancels an asynchronous operation by the GetAddrInfoEx function.
GetAddrInfoExOverlappedResult	Gets the return code for an OVERLAPPED structure used by an asynchronous operation for the GetAddrInfoEx function.
GetAddrInfoW	Provides protocol-independent translation from a Unicode host name to an address.
gethostbyaddr	Retrieves the host information corresponding to a network address.
gethostbyname	Retrieves host information corresponding to a host name from a host database. Deprecated: use getaddrinfo instead.
gethostname	Retrieves the standard host name for the local computer.
GetHostNameW	Retrieves the standard host name for the local computer as a Unicode string.
getipv4sourcefilter	Retrieves the multicast filter state for an IPv4 socket.
GetNameByType	Retrieves the name of a network service for the specified service type.
getnameinfo	Provides name resolution from an IPv4 or IPv6 address to an ANSI host name and from a port number to the ANSI service name.
GetNameInfoW	Provides name resolution from an IPv4 or IPv6 address to a Unicode host name and from a port number to the Unicode service name.
getpeername	Retrieves the address of the peer to which a socket is connected.
getprotobyname	Retrieves the protocol information corresponding to a protocol name.
getprotobynumber	Retrieves protocol information corresponding to a protocol number.
getservbyname	Retrieves service information corresponding to a service name and protocol.
getservbyport	Retrieves service information corresponding to a port and protocol.
GetService	Retrieves information about a network service in the context of a set of default namespaces or a specified namespace.
getsockname	Retrieves the local name for a socket.
getsockopt	Retrieves a socket option.
getsourcefilter	Retrieves the multicast filter state for an IPv4 or IPv6 socket.
GetTypeByName	Retrieves a service type GUID for a network service specified by name.
htond	Converts a double from host to TCP/IP network byte order (which is big-endian).
htonf	Converts a float from host to TCP/IP network byte order (which is big-endian).
htonl	Converts a u_long from host to TCP/IP network byte order (which is big-endian).
htonll	Converts an unsigned __int64 from host to TCP/IP network byte order (which is big-endian).
htons	Converts a u_short from host to TCP/IP network byte order (which is big-endian).
inet_addr	Converts a string containing an (Ipv4) Internet Protocol dotted address into a proper address for the in_addr structure.
inet_ntoa	Converts an (IPv4) Internet network address into a string in Internet standard dotted format.
InetNtop	converts an IPv4 or IPv6 Internet network address into a string in Internet standard format. The ANSI version of this function is inet_ntop.
InetPton	Converts an IPv4 or IPv6 Internet network address in its standard text presentation form into its numeric binary form. The ANSI version of this function is inet_pton.
ioctlsocket	Controls the I/O mode of a socket.
listen	Places a socket a state where it is listening for an incoming connection.
ntohd	Converts an unsigned __int64 from TCP/IP network order to host byte order (which is little-endian on Intel processors) and returns a double.
ntohf	Converts an unsigned __int32 from TCP/IP network order to host byte order (which is little-endian on Intel processors) and returns a float.
ntohl	Converts a u_long from TCP/IP network order to host byte order (which is little-endian on Intel processors).
ntohll	Converts an unsigned __int64 from TCP/IP network order to host byte order (which is little-endian on Intel processors).
ntohs	Converts a u_short from TCP/IP network byte order to host byte order (which is little-endian on Intel processors).
recv	Receives data from a connected or bound socket.
recvfrom	Receives a datagram and stores the source address.
RIOCloseCompletionQueue	Closes an existing completion queue used for I/O completion notification by send and receive requests with the Winsock registered I/O extensions.
RIOCreateCompletionQueue	Creates an I/O completion queue of a specific size for use with the Winsock registered I/O extensions.
RIOCreateRequestQueue	Creates a registered I/O socket descriptor using a specified socket and I/O completion queues for use with the Winsock registered I/O extensions.
RIODequeueCompletion	Removes entries from an I/O completion queue for use with the Winsock registered I/O extensions.
RIODeregisterBuffer	Deregisters a registered buffer used with the Winsock registered I/O extensions.
RIONotify	Registers the method to use for notification behavior with an I/O completion queue for use with the Winsock registered I/O extensions.
RIOReceive	Receives network data on a connected registered I/O TCP socket or a bound registered I/O UDP socket for use with the Winsock registered I/O extensions.
RIOReceiveEx	Receives network data on a connected registered I/O TCP socket or a bound registered I/O UDP socket with additional options for use with the Winsock registered I/O extensions.
RIORegisterBuffer	Registers a RIO_BUFFERID, a registered buffer descriptor, with a specified buffer for use with the Winsock registered I/O extensions.
RIOResizeCompletionQueue	Resizes an I/O completion queue to be either larger or smaller for use with the Winsock registered I/O extensions.
RIOResizeRequestQueue	Resizes a request queue to be either larger or smaller for use with the Winsock registered I/O extensions.
RIOSend	Sends network data on a connected registered I/O TCP socket or a bound registered I/O UDP socket for use with the Winsock registered I/O extensions.
RIOSendEx	Sends network data on a connected registered I/O TCP socket or a bound registered I/O UDP socket with additional options for use with the Winsock registered I/O extensions.
select	Determines the status of one or more sockets, waiting if necessary, to perform synchronous I/O.
send	Sends data on a connected socket.
sendto	Sends data to a specific destination.
SetAddrInfoEx	Registers a host and service name along with associated addresses with a specific namespace provider.
setipv4sourcefilter	Sets the multicast filter state for an IPv4 socket.
SetService	Registers or removes from the registry a network service within one or more namespaces. Can also add or remove a network service type within one or more namespaces.
SetSocketMediaStreamingMode	Indicates whether the network is to be used for transferring streaming media that requires quality of service.
setsockopt	Sets a socket option.
setsourcefilter	Sets the multicast filter state for an IPv4 or IPv6 socket.
shutdown	Disables sends or receives on a socket.
socket	Creates a socket that is bound to a specific service provider.
TransmitFile	Transmits file data over a connected socket handle.
TransmitPackets	Transmits in-memory data or file data over a connected socket.
WSAAccept	Conditionally accepts a connection based on the return value of a condition function, provides quality of service flow specifications, and allows the transfer of connection data.
WSAAddressToString	Converts all components of a sockaddr structure into a human-readable string representation of the address.
WSAAsyncGetHostByAddr	Asynchronously retrieves host information that corresponds to an address.
WSAAsyncGetHostByName	Asynchronously retrieves host information that corresponds to a host name.
WSAAsyncGetProtoByName	Asynchronously retrieves protocol information that corresponds to a protocol name.
WSAAsyncGetProtoByNumber	Asynchronously retrieves protocol information that corresponds to a protocol number.
WSAAsyncGetServByName	Asynchronously retrieves service information that corresponds to a service name and port.
WSAAsyncGetServByPort	Asynchronously retrieves service information that corresponds to a port and protocol.
WSAAsyncSelect	Requests Windows message-based notification of network events for a socket.
WSACancelAsyncRequest	Cancels an incomplete asynchronous operation.
WSACleanup	Terminates use of the Ws2_32.DLL.
WSACloseEvent	Closes an open event object handle.
WSAConnect	Establishes a connection to another socket application, exchanges connect data, and specifies needed quality of service based on the specified FLOWSPEC structure.
WSAConnectByList	Establishes a connection to one out of a collection of possible endpoints represented by a set of destination addresses (host names and ports).
WSAConnectByName	Establishes a connection to another socket application on a specified host and port
WSACreateEvent	Creates a new event object.
WSADeleteSocketPeerTargetName	Removes the association between a peer target name and an IP address for a socket.
WSADuplicateSocket	Returns a structure that can be used to create a new socket descriptor for a shared socket.
WSAEnumNameSpaceProviders	Retrieves information about available namespaces.
WSAEnumNameSpaceProvidersEx	Retrieves information about available namespaces.
WSAEnumNetworkEvents	Discovers occurrences of network events for the indicated socket, clear internal network event records, and reset event objects (optional).
WSAEnumProtocols	Retrieves information about available transport protocols.
WSAEventSelect	Specifies an event object to be associated with the specified set of FD_XXX network events.
__WSAFDIsSet	Specifies whether a socket is included in a set of socket descriptors.
WSAGetFailConnectOnIcmpError	Queries the state of the TCP_FAIL_CONNECT_ON_ICMP_ERROR socket option.
WSAGetIcmpErrorInfo	Queries the source address of an ICMP error received on a TCP socket during connection setup.
WSAGetIPUserMtu	Retrieves the user-defined IP layer MTU for a socket.
WSAGetLastError	Returns the error status for the last operation that failed.
WSAGetOverlappedResult	Retrieves the results of an overlapped operation on the specified socket.
WSAGetQOSByName	Initializes a QOS structure based on a named template, or it supplies a buffer to retrieve an enumeration of the available template names.
WSAGetServiceClassInfo	Retrieves the class information (schema) pertaining to a specified service class from a specified namespace provider.
WSAGetServiceClassNameByClassId	Retrieves the name of the service associated with the specified type.
WSAGetUdpRecvMaxCoalescedSize	Retrieves the maximum size of a received, coalesced message for a UDP socket.
WSAGetUdpSendMessageSize	Retrieves the segmentation message size for a UDP socket.
WSAHtonl	Converts a u_long from host byte order to network byte order.
WSAHtons	Converts a u_short from host byte order to network byte order.
WSAImpersonateSocketPeer	Used to impersonate the security principal corresponding to a socket peer in order to perform application-level authorization.
WSAInstallServiceClass	Registers a service class schema within a namespace.
WSAIoctl	Controls the mode of a socket.
WSAJoinLeaf	Joins a leaf node into a multipoint session, exchanges connect data, and specifies needed quality of service based on the specified structures.
WSALookupServiceBegin	Initiates a client query that is constrained by the information contained within a WSAQUERYSET structure.
WSALookupServiceEnd	Frees the handle used by previous calls to WSALookupServiceBegin and WSALookupServiceNext.
WSALookupServiceNext	Retrieve the requested service information.
WSANSPIoctl	Developers to make I/O control calls to a registered namespace.
WSANtohl	Converts a u_long from network byte order to host byte order.
WSANtohs	Converts a u_short from network byte order to host byte order.
WSAPoll	Determines status of one or more sockets.
WSAProviderConfigChange	Notifies the application when the provider configuration is changed.
WSAQuerySocketSecurity	Queries information about the security applied to a connection on a socket.
WSARecv	Receives data from a connected socket.
WSARecvDisconnect	Terminates reception on a socket, and retrieves the disconnect data if the socket is connection oriented.
WSARecvEx	Receives data from a connected socket.
WSARecvFrom	Receives a datagram and stores the source address.
LPFN_WSARECVMSG (WSARecvMsg)	Receives data and optional control information from connected and unconnected sockets.
WSARemoveServiceClass	Permanently removes the service class schema from the registry.
WSAResetEvent	Resets the state of the specified event object to nonsignaled.
WSARevertImpersonation	Terminates the impersonation of a socket peer.
WSASend	Sends data on a connected socket.
WSASendDisconnect	Initiates termination of the connection for the socket and sends disconnect data.
WSASendMsg	Sends data and optional control information from connected and unconnected sockets.
WSASendTo	Sends data to a specific destination, using overlapped I/O where applicable.
WSASetEvent	Sets the state of the specified event object to signaled.
WSASetFailConnectOnIcmpError	Sets the state of the TCP_FAIL_CONNECT_ON_ICMP_ERROR socket option.
WSASetIPUserMtu	Sets the user-defined IP layer MTU on a socket.
WSASetLastError	Sets the error code.
WSASetService	Registers or removes from the registry a service instance within one or more namespaces.
WSASetSocketPeerTargetName	Used to specify the peer target name (SPN) that corresponds to a peer IP address. This target name is meant to be specified by client applications to securely identify the peer that should be authenticated.
WSASetSocketSecurity	Enables and applies security for a socket.
WSASetUdpRecvMaxCoalescedSize	Sets the maximum size of a coalesced message set on a UDP socket.
WSASetUdpSendMessageSize	Sets the segmentation message size on a UDP socket.
WSASocket	Creates a socket that is bound to a specific transport-service provider.
WSAStartup	Initiates use of WS2_32.DLL by a process.
WSAStringToAddress	Converts a numeric string to a sockaddr structure.
WSAWaitForMultipleEvents	Returns either when one or all of the specified event objects are in the signaled state, or when the time-out interval expires.