Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

for example actionType "vlan"

#987

They were implemented using SO_SNDTIMEO/SO_RCVTIMEO on the
socket descriptor - but that doesn't work now the socket is
non-blocking. Instead, set deadlines on the file read/write.

Signed-off-by: Rob Murray <rob.murray@docker.com>

Signed-off-by: Daman Arora <aroradaman@gmail.com>

fou module added a bunch of new attributes in commit
torvalds/linux@1713cb3

which caused the old parsing logic failed, fix and add support for these attrributes.

Add a specific error to report that a netlink response had
NLM_F_DUMP_INTR set, indicating that the set of results may be
incomplete or inconsistent.

unix.EINTR was previously returned (with no results) when the
NLM_F_DUMP_INTR flag was set. Now, errors.Is(err, unix.EINTR) will
still work. But, this will be a breaking change for any code that's
checking for equality with unix.EINTR.

Return results with ErrDumpInterrupted. Results may be incomplete
or inconsistent, but give the caller the option of using them.

Look for NLM_F_DUMP_INTR in more places:
- linkSubscribeAt, neighSubscribeAt, routeSubscribeAt
  - can do an initial dump, which may report inconsistent results
  -> if there's an error callback, call it with ErrDumpInterrupted
- socketDiagXDPExecutor
  - makes an NLM_F_DUMP request, without using Execute()
  -> give it the same behaviour as functions that do use Execute()

Signed-off-by: Rob Murray <rob.murray@docker.com>