Thanks to vtorri for poiting out about close() is not the correct
socket function, we should use closesocket() instead.
Also defined SOCKET to int on Linux so we can use the same 'type' and
avoid lots of ifdef in our code. On Windows it's unsigned, thus would
cause some warnings about incorrect signed comparison.
Defined INVALID_SOCKET=-1 and SOCKET_ERROR=-1 on non-Windows platforms
so we can keep the same construct 'function() == error' and it should
work on POSIX and windows.
I cannot test these on Windows, but the situation should be improved
with this commit.
if no hints were specified, getaddrinfo() will assume ai_flags as
AI_ADDRCONFIG | AI_V4MAPPED, which only reports useful results based
on what system supports. For instance AI_ADDRCONFIG will only return
IPv4 if IPv4 address exists, likewise IPv6 will only be returned if
IPv6 address is configured, avoiding these to be tried and error for
most local networks where such address could not be used. AI_V4MAPPED
will map IPv4 address over IPv6 if no IPv4 was found.
This is the initial UDP server that works similarly to the TCP one,
however under the hood it's widely different since the socket is
reused for all "clients", thus needs a new Efl.Net.Server.Udp.Client
(Efl.Net.Socket) as Efl.Net.Socket.Udp exposes the fd and options such
as 'cork', which would interfere in other clients.
The main socket will read the packets and find an existing client to
feed it. If no client exists, then it will create one if not overr
limit. Since there is no kernel-queuing as done by listen()/accept(),
the 'no reject' case will just accept the client anyway.
Next commits will improve UDP server handling with some advanced
features:
- join multicast groups
- bind to a specific interface (SO_BINDTODEVICE)
- block packets going out of local network (SO_DONTROUTE)
- specify priorities (SO_PRIORITY)
Gustavo Sverzut Barbieri