MUC joining issue on jabber.ru

Smack Smack Support
1

When I had already entered the multi-user chat in this instance from Android application and it began to load the list of users with presence, a rather strange problem arose with parsing replies and at that moment the connection was interrupted.

I have no idea what is special about Smack’s MUC feature (or maybe custom QIP client presence), since this instance caused an parsing error.

SCR_20240312_135216_studio64
SCR_20240312_135216_studio641036×730 72.7 KB

  • Smack ver. 4.4.0 (Gradle)
  • Full exception in file and first screenshot.

smack_issue_2024-03-12.txt
smack_issue_2024-03-12_stacktrace.txt

UPD: I tried with Smack 4.4.6, nothing has changed.

2

I don’t think we see the exception that was thrown during parsing in the screenshot. I think the NotConnectedException is probably a consequence the previous parsing exception.

Only the parsing exception will tell us what caused it.

3

I think the NotConnectedException is probably a consequence the previous parsing exception

The only catch is that Smack displays this exception in the logs, which led to the disconnection.

mucm = MultiUserChatManager.getInstanceFor(
   xmppClient.getConnection()
); // <-- ok
muc = mucm.getMultiUserChat(JidCreate.entityBareFrom((String) id)); // <-- ok
muc.join(Resourcepart.from(nickname)); //<-- disconnected due to parsing error and throwing NotConnectedException

// origin of exception, no specifics
Caused by: java.lang.NumberFormatException: Value out of range. Value:"128" Radix:10
at java.lang.Byte.parseByte(Byte.java:153)
at java.lang.Byte.valueOf(Byte.java:207)
at java.lang.Byte.valueOf(Byte.java:233)
at org.jivesoftware.smack.util.ParserUtils.getByteAttributeFromNextText(ParserUtils.java:197)
at org.jivesoftware.smack.util.PacketParserUtils.parsePresence(PacketParserUtils.java:453)
at org.jivesoftware.smack.util.PacketParserUtils.parseStanza(PacketParserUtils.java:115)
at org.jivesoftware.smack.AbstractXMPPConnection.parseAndProcessStanza(AbstractXMPPConnection.java:1448)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.access$1000(XMPPTCPConnection.java:130) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.parsePackets(XMPPTCPConnection.java:969) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.access$700(XMPPTCPConnection.java:913) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader$1.run(XMPPTCPConnection.java:936)

For detailed debugging, it may be necessary to monitor stanzas entering the client input.

4

Not sure if I understand, but the original exception should either be logged and/or thrown. I am pretty sure it is made available to the “user”. If not, then this is something that should be fixed in Smack. How did you obtain the exception below?

I am pretty sure that this is caused by a presence stanza with an invalid priority value (128).

5
  1. I logged into my account, which is located in the jabber.ru instance.
  2. I checked the list of chatrooms in the services provided by the instance.
  3. I joined to the runet-chat@conference.jabber.ru chatroom.
  4. At the entrance, Smack receives an incorrect priority number in the occupations’ presences and disconnects at this point.

изображение

6

The screenshot that’s provided in the first post in this thread shows that a <priority>128</priority> is being sent.

This is an invalid value. The value MUST be an integer between -128 and +127, as specified here: RFC 6121 - Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence

It appears that someone is sending an invalid presence stanza to a chatroom, and the server on conference.jabber.ru is not rejecting this, but instead broadcasts it.

7

It may be worth setting Stanzas processing to a correct priority value if initially this priority number is outside this range?

8

The problem here isn’t Smack. It is strict in what it accepts, but the data that it gets to parse is obviously invalid. There’s a valid argument to be made for Smack to simply drop data that is invalid, and that’s the design choice that was made here.