Broken recvmmsg #30
Description
Implementation broken when using non-blocking sockets and/or MSG_DONTWAIT. Returns either error or 'vlen' worth of messages. Discarding any messages and returing when an error occurs.
https://man7.org/linux/man-pages/man2/recvmmsg.2.html
If an error occurs after at least one message has been received, the
call succeeds, and returns the number of messages received. The
error code is expected to be returned on a subsequent call to
recvmmsg(). In the current implementation, however, the error code
can be overwritten in the meantime by an unrelated network event on a
socket, for example an incoming ICMP packet.