RangeError

[mattjay]

Get an interesting error & I'm not sure what is causing it.
I've included the most recent question I got to the server and the error dump.

IPADDRESS:21018/udp4 {"id":11130,"type":"request","responseCode":0,"opcode":"query","authoritative":false,"truncated":false,"recursion_desired":false,"recursion_available":false,"authenticated":false,"checking_disabled":false,"question":[{"name":"MYDOMAIN.com","type":"A","class":"IN"}]}

buffer.js:579
throw new RangeError('Trying to access beyond buffer length');
^
RangeError: Trying to access beyond buffer length
at checkOffset (buffer.js:579:11)
at Buffer.readUInt8 (buffer.js:585:5)
at domain_parts (/home/MYREPO/node_modules/dnsd/parse.js:274:20)
at add_record (/home/MYREPO/node_modules/dnsd/parse.js:167:16)
at Object.sections (/home/MYREPO/node_modules/dnsd/parse.js:161:7)
at Request.DNSMessage.parse (/home/MYREPO/node_modules/dnsd/message.js:99:30)
at Request.DNSMessage (/home/MYREPO/node_modules/dnsd/message.js:55:10)
at new Request (/home/MYREPO/node_modules/dnsd/server.js:158:11)
at Server.on_udp (/home/MYREPO/node_modules/dnsd/server.js:148:13)
at Socket. (/home/MYREPO/node_modules/dnsd/server.js:45:54)
at Socket.EventEmitter.emit (events.js:98:17)

Any help or suggestions would be greatly appreciated.

[mattjay]

Seeing this more and more often on any server I use running dnsd

Will try to diagnose today but anybody else seeing this issue and have any insight?

IPADDRESS:33582/udp4 {"id":58080,"type":"request","responseCode":0,"opcode":"query","authoritative":false,"trun
cated":false,"recursion_desired":true,"recursion_available":false,"authenticated":false,"checking_disabled":false,"
question":[{"name":"www.DOMAIN.com","type":"A","class":"IN"}]}

buffer.js:579
    throw new RangeError('Trying to access beyond buffer length');
    ^
RangeError: Trying to access beyond buffer length
at checkOffset (buffer.js:579:11)
at Buffer.readUInt8 (buffer.js:585:5)
at domain_parts (/home/MYREPO/node_modules/dnsd/parse.js:274:20)
at add_record (/home/MYREPO/node_modules/dnsd/parse.js:167:16)
at Object.sections (/home/MYREPO/node_modules/dnsd/parse.js:161:7)
at Request.DNSMessage.parse (/home/MYREPO/node_modules/dnsd/message.js:99:30)
at Request.DNSMessage (/home/MYREPO/node_modules/dnsd/message.js:55:10)
at new Request (/home/MYREPO/node_modules/dnsd/server.js:158:11)
at Server.on_udp (/home/MYREPO/node_modules/dnsd/server.js:148:13)
at Socket. (/home/MYREPO/node_modules/dnsd/server.js:45:54)
at Socket.EventEmitter.emit (events.js:98:17)

[jhs]

Hi, @mattjay. I have not forgotten you! This is a very interesting bug. I have to say, we use dnsd to run npmjs and I have never seen this problem, so you have found some sort of untested or unexercised code.

Is it possible for you to run tcpdump or something and capture the DNS packets? Would you mind attaching a .pcap file (or sending it to me privately)?

One mystery is whether the 58080 request there is the problem, or if the packet after that is the problem. The bug is in the parsing code, but that log message indicates a successful parse. So I wonder if it is crashing on the next packet.

[jhs]

Okay, @mattjay, this error is coming from within inside an infinite loop. The code is obviously supposed to break out of it.

The most direct way to fix this is to capture that data that is triggering the error. You will need to either use tcpdump or edit the JavaScript code to log that message before it throws the exception. Let me know if I can help.

[BrianCraig]

Hello jhs ! i have the same problem ! Im using DNSD for a project, and i only use this module in 4 lines

var dnsd = require('dnsd');
dnsd.createServer(function(req, res) {
res.end('186.23.145.50');
}).listen(53);

But, today crashed with the same error. I am only giving some A records, that IP is my home IP, and when the error succeded i wasnt making a request to the module ( maybe other person was doing an request, but its just probably )

Im sorry for my bad English, my native language is Spanish.

-- Edit
If you want to know, im using Windows 7 ( maybe thats the reason because npmjs works great )

[jhs]

@BrianCraig great! That means the problem is from some request coming from the Internet.

Are you using the latest version, v0.9.4?

[BrianCraig]

@jhs No, im using 0.9.2, Im going to update the module, did you try to repair the Bug after 0.9.2 ?

[BrianCraig]

Using dnsd 0.9.4, Today got the same problem

buffer.js:582
throw new RangeError('Trying to access beyond buffer length');
^
RangeError: Trying to access beyond buffer length
at checkOffset (buffer.js:582:11)
at Buffer.readUInt8 (buffer.js:588:5)
at domain_parts (D:\vps\node_modules\dnsd\parse.js:274:20)
at add_record (D:\vps\node_modules\dnsd\parse.js:167:16)
at Object.sections (D:\vps\node_modules\dnsd\parse.js:161:7)
at Request.DNSMessage.parse (D:\vps\node_modules\dnsd\message.js:99:30)
at Request.DNSMessage (D:\vps\node_modules\dnsd\message.js:55:10)
at new Request (D:\vps\node_modules\dnsd\server.js:161:11)
at Server.on_udp (D:\vps\node_modules\dnsd\server.js:151:13)
at Socket. (D:\vps\node_modules\dnsd\server.js:45:54)
at Socket.EventEmitter.emit (events.js:98:17)

[jhs]

Thanks. I will need to see the data to move forward on this ticket.

[jhs]

@BrianCraig and @mattjay, I have two ideas, both are a bit intense. Let me know if you can help out on either one.

1. You run tcpdump on that server and privately send me the pcap file. Basically it is a command-line tool, plus some waiting, plus some emailing.
2. You run a modified version of dnsd where we add a feature for it to log all data received before it attempts to parse it.

I think either one of those will allow me to close this bug. Thanks!

[BrianCraig]

Ok! The only thing, im a bit noob on this, you will have to say which command should i run on tcpdump ( Server is on port 53 ), and say us when you have the branch ( which logs the data )

[BrianCraig]

remember, that im using windows ( i think there is no tcpdump ) where do i download it ?

[tommedema]

is this still a problem?

[mattjay]

I'm not sure honestly since I started using forever it kind of got deprioritized for me.

[tommedema]

@mattjay how is forever related to dynamic DNS?

[mattjay]

@tommedema it isn't. but if my dns is crashing here and there I'm not noticing it anymore and haven't got around to log surfing or trying to fix this error.

[codewise-nicolas]

The fix in issue #11 may fix this problem.