Re: [Qemu-devel] [Bug 1003054] Re: Socket not closed when a connection ends

[Zhi Yong Wu]

Please check my patch: [PATCH v4] net: add the support for -netdev
socket, listen
It fix this issue.

On Tue, May 29, 2012 at 7:04 PM, Vincent Autefage
<address@hidden> wrote:
> This implies serious duplication problem in case of reboot :
>
> A [192.168.0.1] <--> B [192.168.0.2]
>
>
> A# ping 192.168.0.1
> PING 192.168.0.1 56(84) bytes of data
> 64 bytes from 192.168.0.1: icmp_req=1 ttl=64 time=3.82 ms
> 64 bytes from 192.168.0.1: icmp_req=2 ttl=64 time=0.344 ms
> 64 bytes from 192.168.0.1: icmp_req=3 ttl=64 time=0.325 ms
>
> B# reboot
>
> A# ping 192.168.0.1
> PING 192.168.0.1 56(84) bytes of data
> 64 bytes from 192.168.0.1: icmp_req=1 ttl=64 time=3.82 ms
> 64 bytes from 192.168.0.1: icmp_req=1 ttl=64 time=3.82 ms (DUP!)
> 64 bytes from 192.168.0.1: icmp_req=2 ttl=64 time=0.344 ms
> 64 bytes from 192.168.0.1: icmp_req=2 ttl=64 time=0.344 ms (DUP!)
> 64 bytes from 192.168.0.1: icmp_req=3 ttl=64 time=0.325 ms
> 64 bytes from 192.168.0.1: icmp_req=3 ttl=64 time=0.325 ms (DUP!)
>
> Vince
>
> --
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/1003054
>
> Title:
>  Socket not closed when a connection ends
>
> Status in QEMU:
>  New
>
> Bug description:
>  Hi,
>
>  I've noticed in the QEMU monitor that when a TCP connection between to
>  QEMU virtual machines is closed in one side, the other side is not
>  closed. Consequence is that the network behavior is completely messed
>  up in case of a reconnection.
>
>  For instance, we consider that we have 2 virtual machines :
>
>  $ qemu -name A -net nic vlan=0 -net socket,vlan=0,listen=127.0.0.1:7000
>  $ qemu -name B -net nic vlan=0 -net socket,vlan=0,connect=127.0.0.1:7000
>
>  If the socket of B is closed (error or machine down), the socket in A
>  is not closed :
>
>  B % host_net_remove 0 socket.0
>
>  A % info network
>    e1000.0: ...
>    socket.0: ... (The removed connection)
>
>  B % host_net_add socket vlan=0,connect=127.0.0.1:7000
>
>  A % info network
>    e1000.0: ...
>    socket.0: ...  (The removed connection)
>    socket.1: ...  (The new connection)
>
>  By not perform any close on sockets of A, the new communication
>  between A and B is corrupted (duplicated packets, invalid
>  transmission, etc.).
>
>  In the case of the close was performed by A, B should detect a problem
>  on the socket and  retry a new connection, unfortunately, this is not
>  the case.
>
>
>  Those two problems corrupt the dynamicity of a QEMU topology which could be 
> strongly problematic for the development of network tools based on QEMU.
>
>
>  Thanks a lot.
>  Vince
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/1003054/+subscriptions
>



-- 
Regards,

Zhi Yong Wu