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TakahikoKawasaki / nv-websocket-client

High-quality WebSocket client implementation in Java.
Apache License 2.0
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RFC6555 support #112

Closed biaxident closed 5 years ago

biaxident commented 7 years ago

Hi! Thank you for the great library again! We have major issue with nv-websocket-client that it has not correct ipv4 fallback when target host not reachable by ipv6. I'm talking about https://tools.ietf.org/html/rfc6555 and so called dual-stack hosts. WebSocketFactory uses straightforward InetSocketAddress obtained by InetAddress.getByName() function instead of InetAddress.getAllByName() to handle all existing InetAdresses. Is there are plans to add rfc6555 support to nv-websocket-client or is it possible to customize your library somehow to write it ourselves? This issue is very critical for us, because we have a lot of complaints from our users about this.

TakahikoKawasaki commented 7 years ago

I read RFC 6555 and understood what the problem is.

If java.net.Socket.connect(SocketAddress endpoint, int timeout) can be retried even after it throws an exception without re-creation of the Socket instance, it may be relatively easy to implement the code which tries all the addresses returned by getAllByName().

@biaxident Could you investigate whether Socket.connect() can be called twice or more on the same Socket instance until connect() succeeds?

biaxident commented 7 years ago

Thank you for fast reply. I've checked the behavior of calling Socket.connect() on already exceptioned socket. Unfortunately, in this case the second connect completes with exception java.net.ConnectException: failed to connect to ...: connect failed: EBADF (Bad file descriptor).

@TakahikoKawasaki Is it possible to recreate socket after exception is thrown?

TakahikoKawasaki commented 7 years ago

@biaxident Thank you for the investigation. I'll try to devise a mechanism for the issue described in RFC 6555. How urgent is this issue for you?

biaxident commented 7 years ago

It's pretty urgent. I think we will fork the repo and do it as soon as possible.

vazir commented 6 years ago

@TakahikoKawasaki Hi. Issue is listed as open. Any plans to fix it?

sjkummer commented 5 years ago

Also ran into this. People happen to have IPv6 enabled in their routers without having "real" IPv6 WAN connectivity. We may experience this more often, since more users & companies are starting their IPv6 journey.

//edit: seems like @biaxident already implemented a solution in his fork: https://github.com/biaxident/nv-websocket-client/commit/1676e7f2ed225a479d0be03fd75e9d48a565bfa3

dbrgn commented 5 years ago

I'm also affected by this. If a domain has both A and AAAA records, and if a device has a local IPv6 address but no proper routes set up, then connecting fails.

@biaxident could you maybe create a pull request against this repo with your implementation, so that the change can get upstreamed? (I'm not sure about the proxy change, I don't need proxy support but as far as I understand this has simply been removed.)