Bare socket implementation & proxy support

[rmckay]

This isn't really a 'bug' per-say, but it would be really nice to have this library implemented on top of the regular java Socket interface rather than the java nio one because the nio stuff doesn't work with proxy servers http://blog.tsunanet.net/2010/08/java-nio-and-overengineering.html

[Davidiusdadi]

When you talk about the socket interface do you mean the server or the client side?

[rmckay]

On Thu, 3 May 2012 09:22:17 -0700, David Rohmer wrote:

When you talk about the socket interface do you mean the server or
the client side?

I'm using it on the client side (actually I'm using
https://github.com/benkay/java-socket.io.client which uses WebSocket
under the hood).

Cheers,
Rob

[Davidiusdadi]

i never needed to authenticate to a proxy when using websockts and also did not considered it during development even though it is covered by the protocol specification http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17#page-17

So sooner or later i will take care of it.

Regarding this blogpost: Someone discovered that nonblocking io consumes more memory than blocking one...by use of his smart mind and fancy inspection tools. He probability also thinks of wappers as an antipattern because of performance loss duo avoidable function calls.

In case of my humble english could not stop you from despising nio you will probbably want your non nio websocket :)

Probably someone will have to implement such a non nio client then. It would be great if that someone would be you.

But currently there is not so much you can do because the IO related stuff is not yet 100% separated from the rest.
But because we want wss we need that separation anyway.
After pull 83 is through i will make sure that one can build his server or client as he likes.

EDIT: I highly likely can not lock horns with the author of that post in such topics also its fun to act as if :)
Someday....

[TooTallNate]

When I originally wrote this lib, I started off with the regular Socket class. I quickly bumped into walls when it came to trying to read and write data at the same time. At least when I implemented draft 75, non-blocking IO was a requirement because you have to both read and write data at the same time, and using two threads for that would be bad.

Anyways, I'm not speaking for David here, but I doubt this lib will ever have a version that doesn't use non-blocking IO.

[rmckay]

On Sat, 5 May 2012 23:07:03 -0700, Daniel Wu wrote:

NIO works with proxies, it just does not support the global VM proxy
properties (e.g. -Dhttp.proxyHost) which is not flexible (it's kind
of
having everything proxied or nothing proxied) and I never use them.
If
you want nio with proxies you just need a couple of lines of code:

Proxy proxy = new Proxy(Proxy.Type.HTTP, proxyUrl);
URL url = new URL("http://java.sun.com/");
URConnection conn = url.openConnection(proxy);

Although bio is slightly faster in a low concurrent environment, but
it does not scale. bio creates too many threads which put too much
pressure on the CPU context switching, and the JVM will also be
slowed
down by the big heap which bio model requires. Most importantly, you
have a hard limit of native threads on most operating systems. So
many
projects, especially server side projects, are going to drop bio
support totally. AFAIK, jetty 9 will totally remove bio support. Some
fancy languages I have been using like erlang do not provide a bio
model at all, its I/O was written in C with non-blocking model, it
uses a few shared native threads to simulate lightweight process
which
can scale up to millions concurrent processes on a commodity server.
Although Java does not have this programming model at language level
like erlang but you should be able to achieve the same scalability
with the nio model.

Thanks for all the replies..

For my purposes I only want one or possibly two WebSockets so the
overhead is almost completely irrelevant.. it's merely a question of
getting something that works with proxies. I'm not sure I understand
your example lines above -- surely that is for use with regular Java
Sockets, not the SocketChannel nio stuff used by WebSocket.. there
doesn't appear to be any Proxy support in the nio SocketChannel classes
which is basically my problem. If you want proxies you have to implement
your own proxy support on top of the SocketChannel. I might even resort
to some non-java solution - there are libraries you can preload that
take over the operating system socket io functions and add proxy support
(for example http://tsocks.sourceforge.net/).. but I'll play with java
solutions for a bit longer.

I originally started trying to write a replacement SocketChannel class
based on the original Socket class (using different threads for
reading/writing).. and was going to try and hack up a classloader to
poke it in place of the nio one but that turned out to be a pain
(loading my version in place of the 'real one').. still might be worth
doing for other purposes but probably not this.

I then started to hack some code into the WebSocket library to support
an HTTP proxy -- should be fairly simple, just make it spit out

CONNECT :80 HTTP/1.1
Host:

and then eat up the

HTTP/1.1 Connection Established.

message and then resume processing as per usual. With SOCKS it is
pretty similar except a more compact protocol.

http://en.wikipedia.org/wiki/SOCKS#Protocol

it's still just a case of sending one write and expecting one read and
from then on it's just a regular TCP connection.

I haven't quite got this working yet though.. basically I am having
problems handling the "HTTP/1.1 Connection Established." reply which
gets processed by the usual handleRead() stuff which then ends up
closing the connection due to it being unexpected.. I should be able to
get this working though.. I'll post whatever I come up with here
although I'm afraid it may end up being more of a complete hackjob than
something anyone else would want to use ;)

Cheers,
Rob

[DanielYWoo]

Sorry, Rob, I realized I replied too fast and deleted my comment but you still saw it:-). My fault, SocketChannel does not support proxy and we have to tunnel it. Hopefully this can help you a little bit:
http://www.koders.com/java/fid6C544EFC7FC1729D0DD2E500C72B74FD88479F6A.aspx

[arunkjn]

Long time since the last reply. Any progress here?
I am using this in one of my projects.
I need to forward a websockets proxy request from a node.js proxy server to the socket.io server.
It connects directly to the client, but does not support connection through proxy.
Is there any workaround or hack?

[Davidiusdadi]

We don't have proxies yet but there is progress :)

It can be easily implemented the same way ssl has been implemented:

You derive a new class from WrappedByteChannel ( just like SSLSocketChannel2 does) which performs the proxy stuff.
I have not yet looked at how to "talk" to a proxy but it seems to be simple:

CONNECT example.com:80 HTTP/1.1
Host: example.com
Proxy-authorization: Basic ZWRuYW1vZGU6bm9jYXBlcyE=

I think i will have implemented it within the next month.

[arunkjn]

Thanks for the update David.

Will look into this and try to implement proxy support.

I am also considering using an embedded Jetty server in my application to serve websocket content.
Jetty seems to support proxy.

Will let you know what I eventually come up with.

Thanks & regards,
Arun Kumar Jain | +91 9379820103 | www.mu-sigma.comhttp://www.mu-sigma.com |

From: David Rohmer [mailto:notifications@github.com]
Sent: Friday, September 28, 2012 2:02 AM
To: TooTallNate/Java-WebSocket
Cc: Arun Kumar Jain
Subject: Re: [Java-WebSocket] Bare socket implementation & proxy support (#88)

We don't have proxies yet but there is progress :)

It can be easily implemented the same way ssl has been implemented:

You derive a new class from WrappedByteChannel ( just like SSLSocketChannel2 does) which performs the proxy stuff.
I have not yet looked at how to "talk" to a proxy but it seems to be simple:

CONNECT example.com:80 HTTP/1.1
Host: example.com
Proxy-authorization: Basic ZWRuYW1vZGU6bm9jYXBlcyE=

I think i will have implemented it within the next month.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/88#issuecomment-8952936.

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[leizhu]

@Davidiusdadi ,I have also used Java-WebSocket in my project, and need to use proxy. Does the client support proxy now?

[Davidiusdadi]

Until now there has been no proxy support. But i just introduced basic proxy support in 76d1206.
The default proxy-"handshake" uses this scheme:

CONNECT example.com:80 HTTP/1.1
Host: example.com

I just copied the scheme it from http://tools.ietf.org/html/rfc6455#section-4.1 and did not even tried out if the code works since i currently do not have a proxy at hand.

In order to get better proxy support i would like you to take a look at src/main/example/ProxyClientExample.java and implement what is still missing.

Lets stay in contact to get proxy support working as soon as possible.

[leizhu]

compile:
[javac] Compiling 19 source files to /Users/leizhu/workspace/Cetas/Java-WebSocket/build/classes
[javac] /Users/leizhu/workspace/Cetas/Java-WebSocket/src/main/java/org/java_websocket/client/WebSocketClient.java:71: cannot find symbol
[javac] symbol : class DefaultWebSocketClientFactory
[javac] location: class org.java_websocket.client.WebSocketClient
[javac] private WebSocketClientFactory wsfactory = new DefaultWebSocketClientFactory( this );
[javac] ^
[javac] Note: /Users/leizhu/workspace/Cetas/Java-WebSocket/src/main/java/org/java_websocket/client/DefaultSSLWebSocketClientFactory.java uses or overrides a deprecated API.
[javac] Note: Recompile with -Xlint:deprecation for details.
[javac] 1 error

@Davidiusdadi ,seems that the class DefaultWebSocketClientFactory is missed...Can not compile with the latest codes

[Davidiusdadi]

ops, seems i forgot to commit that file. i will push it after work around 8 pm GMT+1