Re: ipv4 udplite broken in >=linux-3.0 ?
From: Jinxin Zheng <hidden>
Date: 2011-11-18 12:35:31
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On Fri, Nov 18, 2011 at 8:04 PM, Hagen Paul Pfeifer [off-list ref] wrote:
* Jinxin Zheng | 2011-11-18 12:09:25 [+0800]:quoted
I don't know how to debug udplite. Can any one of you give me a tip on how to get more debug info, then I can do further test and provide with it?net-next works for me: $ sudo aptitude install netsend $ sudo tcpdump -n -ttt -vv -i lo > pcap.trace & $ netsend udplite receive & $ netsend udplite transmit /etc/fstab 127.0.0.1 $ cat pcap.trace 00:00:00.000000 IP (tos 0x0, ttl 64, id 30602, offset 0, flags [DF], proto unknown (136), length 40) 127.0.0.1 > 127.0.0.1: udplite 20 00:00:00.000074 IP (tos 0x0, ttl 64, id 30603, offset 0, flags [DF], proto unknown (136), length 1125) 127.0.0.1 > 127.0.0.1: udplite 1105 Kernel version? What is the output of strace?
The kernel version is 3.0. I compiled it myself on a Gentoo i386. I do not use Ubuntu or Debian. Cannot get netsend in Gentoo ... But I did the test using the hello_world application downloaded from Gerrit's wiki: http://www.erg.abdn.ac.uk/~gerrit/udp-lite/ It contains a simple 'server' and a 'client' program. The client sends a "Hello World" to the server, and when the server receives the message it exits. $ tcpdump -n -ttt -vv -i lo > pcap.trace & $ ./server & $ ./client $ cat pcap.trace 00:00:00.000000 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto unknown (136), length 41) 127.0.0.1 > 127.0.0.1: ip-proto-136 21 the pcap trace seems ok. The sendto() in the client returns ok. But the server just cannot return from recv() and echo the message... I can't see anything suspicious from strace for the server or client either... -- Zheng Jinxin