Socket Options and IOCTLs (Windows Embedded CE 6.0)
1/6/2010
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
Concepts
Winsock Service Provider Interface (SPI)
Summary of Socket IOCTL Opcodes