SO_ERROR is used to report asynchronous errors that are the result
of events within the network stack and not synchronous errors that
are the result of a library call(send/recv/connect)
Synchronous results are reported via errno.
Linux Programmer's Manual
...
NAME
getsockopt, setsockopt - get and set options on sockets
...
RETURN VALUE
...
On error, -1 is returned, and errno is set appropriately
Change-Id: I1a1a05a684dff8672aaf47eabee157ac0d275c2d
Signed-off-by: chao.an <anchao@xiaomi.com>
net/tcp: Add logic to send probes when SO_KEEPALIVE is enabled.
net/tcp: TCP socket should not have to be connected to configure KeepAlive.
net/: Add a separate configuration to enable/disable KEEPALIVE socket options.
net/tcp: Arguments to TCP keep-alive timing functions probably should be struct timeval as are the times for other time-related socket options.
net/tcp: Fix a backward conditional
net/tcp: Add some more checks and debug output to TCP-protocol socket options.
net/tcp: Cosmetic changes to some alignment.
net/: Adds socket options needed to manage TCP-keepalive and TCP state machine logic to detect if that the remote peer is alive. Still missing the timer poll logic to send the keep-alive probes and the state machine logic to respond to probes.
net/: psock_recvfrom() is an internal interface and should not set the errno nor should it be a cancellation point.
net/: psock_accept() is not a cancellation point.
net/: psock_getsockopt() and psock_socket*9 are an internal interfaces and should not set the errno.
net/: psock_getsockopt() is an internal interface and should not set the errno.
net/: psock_listen() is an internal interface and should not set the errno.
net/: psock_connect(( is an internal interface and should not set the errno nor should it be a cancellation point.
net/: psock_bind() is an internal interface and should not set the errno.
net/: psock_accept() is an internal interface and should not set the errno.
User-space networking stack API allows user-space daemon to
provide TCP/IP stack implementation for NuttX network.
Main use for this is to allow use and seamless integration of
HW-provided TCP/IP stacks to NuttX.
For example, user-space daemon can translate /dev/usrsock
API requests to HW TCP/IP API requests while rest of the
user-space can access standard socket API, with socket
descriptors that can be used with NuttX system calls.
For the setsockopt() case, it will always use the final option. This means that a time of zero (i.e., not timeout) can only occur if the value zero was explicated provided to setsockopt().
