* Move IP Socket stuff to InternetSocket class which is inherited by TCP/UDP
* Implement sendto() and recvfrom() on TCP socket
* Implement connect() call on UDP
* Implement send() and recv() calls on UDP socket
Note, the registered callback is still disabled by a call to
socket_attach. This will avoid being called after the socket is closed
unless close is called from the attached callback, which is in irq
context.
As pointed out by kjbracey-arm, the previous behaviour was broken
for sockets that started out listening.
It's currently possible to generate a socket event when a non-blocking socket is closed:
1. _pending is set to 0 in https://github.com/ARMmbed/mbed-os/blob/master/features/netsocket/TCPSocket.cpp#L22
when the socket is created.
2. close() calls event() in https://github.com/ARMmbed/mbed-os/blob/master/features/netsocket/Socket.cpp#L66
3. event() increments _pending, and since _pending is 1 it will call _callback() in https://github.com/ARMmbed/mbed-os/blob/master/features/netsocket/TCPSocket.cpp#L167
However, if send() (for example) is called, this can happen:
- send() is called and sets _pending to 0.
- when the data is sent, event() is called, which sets _pending to 1 and calls _callback().
- if close() is called at this point, there won't be an event generated for close() anymore,
since _pending will be set to 2.
Same thing for recv. Also, same thing for TCPServer and UDPSocket.
This PR changes the initial value of _pending to 1 instead of 0, so that
events are never generated for close().
Initially these assertions were added to protected simultaneous
send/recv from the same socket when similarly purposed mutexes were
removed.
However, simultaneous send/recv can still be useful for UDP if the
payload is guaranteed to be less than the MTU across the entire
connection.
nsapi_error_t - enum of errors or 0 for NSAPI_ERROR_OK
nsapi_size_t - unsigned size of data that could be sent
nsapi_size_or_error_t - either a non-negative size or negative error
Seppo Takalo
Deepika
Christopher Haster
Bogdan Marinescu
Martin Kojtal
Jimmy Brisson