Socket Options and IOCTLs (Windows CE 5.0)
The socket options for Winsock are summarized in the following table. More detailed information is provided in section 4 under WSPGetSockOpt and/or WSPSetSockOpt. There are other new protocol-specific socket options that can be found in the Protocol-Specific Annex.
A Windows Sockets service provider must recognize all of these options, and (for WSPGetSockOpt) return plausible values for each. The default value for each option is shown in the following table.
| Value | Type | Description | Default | Note |
|---|---|---|---|---|
| SO_ACCEPTCONN | BOOL | Socket is listening. | FALSE unless a WSPListen has been performed. | |
| SO_BROADCAST | BOOL | Socket is configured for the transmission of broadcast messages. | FALSE | |
| SO_DEBUG | BOOL | Debugging is enabled. | FALSE | (i) |
| SO_DONTLINGER | BOOL | If true, the SO_LINGER option is disabled. | TRUE | |
| SO_DONTROUTE | BOOL | Routing is disabled. Not supported on ATM sockets (results in an error). | FALSE | (i) |
| SO_ERROR | int | Retrieves error status and clear. | 0 | |
| SO_GROUP_ID | GROUP | Reserved. | NULL | Get only |
| SO_GROUP_PRIORITY | int | Reserved. | 0 | |
| SO_KEEPALIVE | BOOL | Keepalives are being sent. Not supported on ATM sockets (results in an error). | FALSE | (i) |
| SO_LINGER | Structure linger | Returns the current linger options. | l_onoff is 0 | |
| SO_MAX_MSG_SIZE | int | Maximum outbound size of a message for message socket types. There is no provision to determine the maximum inbound message size. Has no meaning for stream-oriented sockets. | Implementation dependent | Get only |
| SO_OOBINLINE | BOOL | OOB data is being received in the typical data stream. | FALSE | |
| SO_PROTOCOL_INFOW | structure WSAPROTOCOL_INFOW | Description of protocol information for the protocol that is bound to this socket. | Protocol dependent | Get only |
| SO_RCVBUF | int | Buffer size for receives. | Implementation dependent | (i) |
| SO_REUSEADDR | BOOL | The address to which this socket is bound can be used by others. Not applicable on ATM sockets. | FALSE | |
| SO_SNDBUF | int | Total per-socket buffer space reserved for sends. This is unrelated to SO_MAX_MSG _SIZE or the size of a TCP window. |
Implementation dependent | (i) |
| SO_TYPE | int | The type of the socket (for example, SOCK_STREAM). | As created through socket. | |
| PVD_CONFIG | char FAR * | An opaque data structure object containing configuration information of the service provider. | Implementation dependent | |
| TCP_NODELAY | BOOL | Disables the Nagle algorithm for send coalescing. | Implementation dependent |
Note (i) A service provider may silently ignore this option on WSPSetSockOpt and return a constant value for WSPGetSockOpt, or it may accept a value for WSPSetSockOpt and return the corresponding value in WSPGetSockOpt without using the value in any way.
See Also
Winsock Service Provider Interface (SPI) | Summary of Socket IOCTL Opcodes
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