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Hello,
On Thu, 22 Feb 2001, Radu-Adrian Feurdean wrote:
>
> Hi,
> While trying to implement a load-balancer based on ipvs-0.2.4 I found some
> bugs in the code. The testing environment used is: kernel 2.4.2-pre[34] for
> load balancer and NAT as load-balancing method
>
> 1. TCP state transition diagrams in ipvs/ip_vs_conn.c have initial states in
> the wrong order (according to ipvs/ip_vs.h). The problem is that
> IP_VS_S_SYNACK should be the 5th state in the table and it is the last. I have
> observed this because a close request initiated by the client leaves the
> connection open on the director. Here are the debug messages:
>
> IPVS: Schedule fwd:M s:NONE c:172.18.1.62:3206 v:172.18.1.58:21
> d:172.18.1.231:21 flg:140 cnt:2
> IPVS: TCP input [S...] 172.18.1.231:21->172.18.1.62:3206 state:
> NONE->SYN_RECV cnt:2
> IPVS: TCP input [..A.] 172.18.1.231:21->172.18.1.62:3206 state:
> SYN_RECV->ESTABLISHED cnt:2
> IPVS: TCP input [.FA.] 172.18.1.231:21->172.18.1.62:3206 state:
> ESTABLISHED->CLOSE_WAIT cnt:2
> IPVS: TCP output [..A.] 172.18.1.231:21->172.18.1.62:3206 state:
> CLOSE_WAIT->LAST_ACK cnt:2
> IPVS: TCP output [.FA.] 172.18.1.231:21->172.18.1.62:3206 state:
> LAST_ACK->LISTEN cnt:2
> IPVS: TCP input [..A.] 172.18.1.231:21->172.18.1.62:3206 state:
> LISTEN->ESTABLISHED cnt:2
>
> You can see that the last 2 lines are not exactly a correct behaviour.
>
> 2. The ftp module does not work for passive mode (it doesn't work at all but
> the active mode can be managed using standard masquerading). The FTP handling
> code does not properly deal with the new connection (the director doesn't
> handle it at all).
>
> There is an attached patch that solves the two above-mentioned problems. I'm
> not sure that the second problem is resolved the right way, but at least it
> works.
Ignoring the fact your patch is broken the (1) is a _REAL_ bug.
We must move and insert the SA column before FW. It seems the
SA value is different from Linux 2.2 but the same transition table is
used :)
For (2) we have to analyze where is really the problem. Personally,
I didn't tried the ftp module from long time ago.
Thanks for this report.
> Bye
>
> Radu-Adrian Feurdean
> mailto: raf@xxxxxxxx
> -------------------------------------------------------------------
> "If the night is silent enough you can hear a Windows NT rebooting"
Regards
--
Julian Anastasov <ja@xxxxxx>
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