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Date:      Mon, 20 Jul 2015 20:04:00 +0800
From:      arthurwang <wangzheng@jrq.com>
To:        net@freebsd.org, rizzo@iet.unipi.it
Subject:   Two netmap issues : 1. "protocol 0000 is buggy" , 2: network applications stuck
Message-ID:  <B0D3961A-B30B-426D-BB1C-2C2D0EEB5E4B@jrq.com>
In-Reply-To: <8714904D-22E4-4738-ABF8-C42ACACFEF3B@jrq.com>
References:  <8714904D-22E4-4738-ABF8-C42ACACFEF3B@jrq.com>

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Hi  ,

        I=E2=80=99m new to netmap , =E2=80=9Ca novel framework for fast =
packet I/O=E2=80=9D accroding to =
http://info.iet.unipi.it/~luigi/netmap/#85cb =
<http://info.iet.unipi.it/~luigi/netmap/#85cb>; ,  :). Im doing a test =
for its bridge.c example program , which do a bridging(namely proxying , =
I suppose ) job between NIC and host stack ,by  running  =E2=80=9C./bridge=
 -i net map:ethic=E2=80=9D from command line ,  and I have two problems =
:


Problem 1 :=20

        It issues  =E2=80=9Cprotocol 0000 is buggy=E2=80=9D  once per =
second ,  seems not running correctly, by contrast to the normal state , =
under which print =E2=80=9Cpoll timeout =E2=80=9C once per 2.5 seconds . =
This issue not always exist.=20

        Here is the procedure to reproduce:

        1>  install a centOS 6.5 on vmware fusion 7( host: mbp )
   =20
        2>  download kernel 2.6.32.67 from kernel.org =
<http://kernel.org/>, compile & install it, reboot the guest OS.=20

        3>  clone netmap from https://github.com/ppLorins/netmap =
<https://github.com/ppLorins/netmap>;  , unpack & compile it , insert the =
netma.ko to kernel.

        4>  compile the bridge.c example=20

        5>  run example with =E2=80=9C./bridge -i netmap:eth0=E2=80=9D

        Thus , it will print the error message =E2=80=9Cprotocol 0000 is =
buggy=E2=80=9D , I explore it by google for quite a long time, found =
nothing .=20

        Environment info about the guestOS centOS6.5   , from a =E2=80=9Cn=
ame -a=E2=80=9D call :   =20

        Linux localhost.localdomain 2.6.32.67 #1 SMP Fri Jul 17 08:41:59 =
CEST 2015 i686 i686 i386 GNU/Linux

       As for the NIC driver , I have no idea about it but it was =
simulated by vmware, sorry for this ,but  if you need extra information =
about it , tell me how to view it by command line , and I will reply as =
soon as possible .=20

Problem 2:=20

    Even though Problem 1 not exists ,   the program also appears to be  =
something  wrong , Here are what I found :

    1> ping request from another machine can return normally ( same as I =
supposed ) =20
  =20
    2> new tcp connection(requested by telnet, destination port is 22 ) =
can be successfully established  from other machine  ( same as I =
supposed ) =20

    3>  existing session (pts/0 , pts/1 )  founded by a precede ssh call =
, are stuck , cannot enter any character or get any response into/from =
screen. (confusing)

    4>  new ssh request (represents all  tcp applications ),    cannot =
get response  and timed out. (confusing )

     In my assumption, there should be no difference with or without the =
bridge program running ,  for the upper layer network applications =
.Since bridge just acts  as a proxy between NIC and host stack ,and do =
nothing except that .      Thus all ip(ping) or tcp(ssh) layer =
applications should act as normal , but unfortunately just part of them =
are okay .

     Can anyone help ? I know there are few people using netmap , it=E2=80=
=99s quite a novel technique for network application=E2=80=A6.

     Thanks a lot.
=20


=E2=80=94 ArthurWang
=E2=80=94 Best Regards







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