Rust RCON: Invalid packet type: 4

[ribasco]

Related to issue #86

RCON commands to a rust server fails due to an exception thrown.

The server sends a packet type of '4' which is not officially documented in the source rcon protocol documentation.

com.ibasco.agql.protocols.valve.source.query.rcon.exceptions.RconException: io.netty.handler.codec.DecoderException: com.ibasco.agql.core.exceptions.PacketDecodeException: Invalid packet type: 4
	at com.ibasco.agql.protocols.valve.source.query.rcon.SourceRconMessenger$RequestContext.collectAndRelease(SourceRconMessenger.java:927)
	at com.ibasco.agql.protocols.valve.source.query.rcon.SourceRconMessenger$RequestContext.access$1500(SourceRconMessenger.java:903)
	at com.ibasco.agql.protocols.valve.source.query.rcon.SourceRconMessenger.lambda$send$7(SourceRconMessenger.java:290)
	at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:836)
	at java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:811)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
	at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1990)
	at dev.failsafe.spi.FailsafeFuture.completeResult(FailsafeFuture.java:99)
	at dev.failsafe.AsyncExecutionImpl.complete(AsyncExecutionImpl.java:159)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
	at dev.failsafe.internal.RetryPolicyExecutor.lambda$null$5(RetryPolicyExecutor.java:155)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
	at java.util.concurrent.CompletableFuture.uniWhenCompleteStage(CompletableFuture.java:792)
	at java.util.concurrent.CompletableFuture.whenComplete(CompletableFuture.java:2153)
	at dev.failsafe.internal.RetryPolicyExecutor.lambda$handleAsync$6(RetryPolicyExecutor.java:150)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
	at dev.failsafe.spi.PolicyExecutor.lambda$null$2(PolicyExecutor.java:109)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
	at dev.failsafe.Functions.lambda$null$5(Functions.java:202)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
	at dev.failsafe.Functions.lambda$null$2(Functions.java:152)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
	at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1990)
	at com.ibasco.agql.core.NettyChannelContext.markInError(NettyChannelContext.java:361)
	at com.ibasco.agql.core.NettyMessenger.receive(NettyMessenger.java:340)
	at com.ibasco.agql.core.NettyChannelContext.receive(NettyChannelContext.java:375)
	at com.ibasco.agql.core.transport.handlers.MessageRouter.exceptionCaught(MessageRouter.java:208)
	at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
	at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:281)
	at io.netty.channel.AbstractChannelHandlerContext.fireExceptionCaught(AbstractChannelHandlerContext.java:273)
	at com.ibasco.agql.protocols.valve.source.query.rcon.handlers.SourceRconPacketAssembler.exceptionCaught(SourceRconPacketAssembler.java:290)
	at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
	at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:281)
	at io.netty.channel.AbstractChannelHandlerContext.fireExceptionCaught(AbstractChannelHandlerContext.java:273)
	at com.ibasco.agql.protocols.valve.source.query.rcon.handlers.SourceRconPacketDecoder.exceptionCaught(SourceRconPacketDecoder.java:271)
	at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:381)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at com.ibasco.agql.core.transport.handlers.MessageDecoder.channelRead(MessageDecoder.java:75)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:722)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:658)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:584)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:750)
Caused by: io.netty.handler.codec.DecoderException: com.ibasco.agql.core.exceptions.PacketDecodeException: Invalid packet type: 4
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:480)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:279)
	at com.ibasco.agql.protocols.valve.source.query.rcon.handlers.SourceRconPacketDecoder.channelRead(SourceRconPacketDecoder.java:95)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	... 25 more
Caused by: com.ibasco.agql.core.exceptions.PacketDecodeException: Invalid packet type: 4
	at com.ibasco.agql.protocols.valve.source.query.rcon.packets.SourceRconPacketDecoder.decode(SourceRconPacketDecoder.java:103)
	at com.ibasco.agql.protocols.valve.source.query.rcon.packets.SourceRconPacketDecoder.decode(SourceRconPacketDecoder.java:38)
	at com.ibasco.agql.protocols.valve.source.query.rcon.handlers.SourceRconPacketDecoder.decode(SourceRconPacketDecoder.java:198)
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:510)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:449)
	... 28 more

[ribasco]

This is the packet dump of the decoded response (packet type 4) after issuing a status command

         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 5b 52 43 4f 4e 5d 5b 31 39 32 2e 31 36 38 2e 35 |[RCON][192.168.5|
|00000010| 30 2e 33 3a 36 31 34 35 34 5d 20 73 74 61 74 75 |0.3:61454] statu|
|00000020| 73 00                                           |s.              |
+--------+-------------------------------------------------+----------------+
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 68 6f 73 74 6e 61 6d 65 3a 20 52 75 73 74 0a 76 |hostname: Rust.v|
|00000010| 65 72 73 69 6f 6e 20 3a 20 32 33 34 35 20 73 65 |ersion : 2345 se|
|00000020| 63 75 72 65 20 28 73 65 63 75 72 65 20 6d 6f 64 |cure (secure mod|
|00000030| 65 20 65 6e 61 62 6c 65 64 2c 20 63 6f 6e 6e 65 |e enabled, conne|
|00000040| 63 74 65 64 20 74 6f 20 53 74 65 61 6d 33 29 0a |cted to Steam3).|
|00000050| 6d 61 70 20 20 20 20 20 3a 20 50 72 6f 63 65 64 |map     : Proced|
|00000060| 75 72 61 6c 20 4d 61 70 0a 70 6c 61 79 65 72 73 |ural Map.players|
|00000070| 20 3a 20 30 20 28 35 30 20 6d 61 78 29 20 28 30 | : 0 (50 max) (0|
|00000080| 20 71 75 65 75 65 64 29 20 28 30 20 6a 6f 69 6e | queued) (0 join|
|00000090| 69 6e 67 29 0a 0a 69 64 20 6e 61 6d 65 20 70 69 |ing)..id name pi|
|000000a0| 6e 67 20 63 6f 6e 6e 65 63 74 65 64 20 61 64 64 |ng connected add|
|000000b0| 72 20 6f 77 6e 65 72 20 76 69 6f 6c 61 74 69 6f |r owner violatio|
|000000c0| 6e 20 6b 69 63 6b 73 20 0a 00                   |n kicks ..      |
+--------+-------------------------------------------------+----------------+

Observations:

• The server initially responds with a packet of type 4 (undocumented) which looks like a feedback regarding the issued command.
• Then immediately followed by a another packet of type 0 (documented) which contains the actual response of the server
• Packets of type 4 are not sent when authenticating with the server

[ribasco]

Rust has transitioned from legacy to web rcon (using web sockets) which is not officially supported by this library. There is a note on their readme stating that the legacy will be removed sometime in the future so its worth adding a note in the project documentation.

As to whether or not I will support this new mode in the library, I'll put it in consideration if there is demand for it.

From facepunch:

This will eventually be the default rcon mode. At that point you'll need to use another command to enable the old Rcon. Even more eventually, the old Rcon will be removed - so if you're a tool maker or otherwise, it would be advisable to have a way to talk to web rcon as soon as possible.

[iMax798]

Hello, I now want to develop a set of web management pages based on your code base, tools like rustadmin. I'm very sorry, my English is not very good, and I don't understand some meaning

[ribasco]

Hello, I now want to develop a set of web management pages based on your code base, tools like rustadmin.

I will see if I can make some changes in this library to make rcon work with Rust.

But please keep in mind that this library only supports the Source Rcon Protocol. Facepunch decided to switch from Source Rcon to Webrcon (using Web sockets) some time ago.

If you are planning to develop new management based apps using RCON, you might want to consider using another library that supports rust's websockets version since the legacy mode might be removed in the future.