Re: [UDT] SO_REUSEADDR

[Yunhong Gu <yu...@la...>]

Yes, you can use that line of code to determine if the response is from 
the expected source.

However, I am not sure if by repeating the process UDT can get the correct 
response. I read somewhere that SO_REUSEADDR on UDP has undetermined 
behavior on different systems.

You can test it though. Simply include the "secure" checking code into the 
while loop right above it.

Yunhong


On Sat, 22 Jul 2006 ar...@ph... wrote:

> Yunhong,
>
>  Thank you for your reply.  I do have an idea.  Can you tell me if this is possible.
>
>  Can UDT use IP:port obtained from getpeername() to confirm that the socket is the right one prior to set m_bConnected=ture.  If the socket is wrong, can UDT go thru this again with other sockets until it finds the right one.
>
>  P.S.  In void CUDT::connect(const sockaddr* serv_addr)
>  ...
>     if ((0 != strcmp(req_ip, res_ip)) || (0 != strcmp(req_port, res_port)))
>  ...
>
>  Art Pharn
>
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> 1. SO_REUSEADDR (ar...@ph...)
> 2. Re: SO_REUSEADDR (Yunhong Gu)
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>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 21 Jul 2006 13:31:12 -0700 (PDT)
> From:
> Subject: [UDT] SO_REUSEADDR
> To: udt...@li...
> Cc: Art Pharn
> Message-ID: <200...@we...>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Yunhong,
>
> First, I'd like to complement on the UDT.
>
> I have a question about the SO_REUSEADDR. Does the implementation of UDT prohibit the use of SO_REUSEADDR? When I modify UDT such that I can set the SO_REUSEADDR option directly on sockets that use the same local port, to the same remote host but with diff. remote ports, I found out that I could get a connect on the wrong socket, i.e wrong remote port.
>
> Thanks,
>
> Art Pharn
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> ------------------------------
>
> Message: 2
> Date: Fri, 21 Jul 2006 16:06:29 -0500 (CDT)
> From: Yunhong Gu
> Subject: Re: [UDT] SO_REUSEADDR
> To: Art Pharn
> Cc: udt...@li...
> Message-ID:
>
> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
>
>
>
> I think it is the problem of UDP with SO_REUSEADDR. When you have two UDP
> sockets bound to the same port, it seems there is no way to guarantee
> that an incoming packet goes to one socket rather than the other, becuase
> UDP is connectionless, it cannot use source IP:port to determine the
> destination socket. The outcome may depend on different system
> implementations.
>
> Due to the same reason, the conenction request from remote host may reach
> any local UDT listening socket, thus you may get wrong connection.
>
> I don't think there is any way to support SO_REUSEADDR in UDT, but if you
> have any idea, I would like to try.
>
> Thanks
> Yunhong
>
>
> On Fri, 21 Jul 2006 ar...@ph... wrote:
>
>> Yunhong,
>>
>> First, I'd like to complement on the UDT.
>>
>> I have a question about the SO_REUSEADDR. Does the implementation of UDT prohibit the use of SO_REUSEADDR? When I modify UDT such that I can set the SO_REUSEADDR option directly on sockets that use the same local port, to the same remote host but with diff. remote ports, I found out that I could get a connect on the wrong socket, i.e wrong remote port.
>>
>> Thanks,
>>
>> Art Pharn
>>
>
>
>
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