* core: Apply SO_REUSEPORT to UDP sockets
For some reason, 10 months ago when I implemented SO_REUSEPORT
for TCP, I didn't realize, or forgot, that it can be used for UDP too. It is a
much better solution than using deadline hacks to reuse a socket, at
least for TCP.
Then https://github.com/mholt/caddy-l4/issues/132 was posted,
in which we see that UDP servers never actually stopped when the
L4 app was stopped. I verified this using this command:
$ nc -u 127.0.0.1 55353
combined with POSTing configs to the /load admin endpoint (which
alternated between an echo server and a proxy server so I could tell
which config was being used).
I refactored the code to use SO_REUSEPORT for UDP, but of course
we still need graceful reloads on all platforms, not just Unix, so I
also implemented a deadline hack similar to what we used for
TCP before. That implementation for TCP was not perfect, possibly
having a logical (not data) race condition; but for UDP so far it
seems to be working. Verified the same way I verified that SO_REUSEPORT
works.
I think this code is slightly cleaner and I'm fairly confident this code
is effective.
* Check error
* Fix return
* Fix var name
* implement Unwrap interface and clean up
* move unix packet conn to platform specific file
* implement Unwrap for unix packet conn
* Move sharedPacketConn into proper file
* Fix Windows
* move sharedPacketConn and fakeClosePacketConn to proper file
---------
Co-authored-by: Weidi Deng <weidi_deng@icloud.com>
* added some tests for parseUpstreamDialAddress
Test 4 fails because it produces "[[::1]]:80" instead of "[::1]:80"
* support absolute windows path in unix reverse proxy address
* make IsUnixNetwork public, support +h2c and reuse it
* add new tests
* core: Refactor, improve listener logic
Deprecate:
- caddy.Listen
- caddy.ListenTimeout
- caddy.ListenPacket
Prefer caddy.NetworkAddress.Listen() instead.
Change:
- caddy.ListenQUIC (hopefully to remove later)
- caddy.ListenerFunc signature (add context and ListenConfig)
- Don't emit Alt-Svc header advertising h3 over HTTP/3
- Use quic.ListenEarly instead of quic.ListenEarlyAddr; this gives us
more flexibility (e.g. possibility of HTTP/3 over UDS) but also
introduces a new issue:
https://github.com/lucas-clemente/quic-go/issues/3560#issuecomment-1258959608
- Unlink unix socket before and after use
* Appease the linter
* Keep ListenAll
