linux-kernel - Re: how to read one udp packet with more than one recvfrom() calls?

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Message-Id: <201011091105.56137.varunc@linux.vnet.ibm.com>
Date:	Tue, 9 Nov 2010 11:05:55 +0530
From:	Varun Chandramohan <varunc@...ux.vnet.ibm.com>
To:	ranjith kumar <ranjithproxy@...il.com>
Cc:	"linux-kernel" <linux-kernel@...r.kernel.org>
Subject: Re: how to read one udp packet with more than one recvfrom() calls?

try MSG_PEEK option.

Regards,
Varun 

On Monday, November 08, 2010 12:38:47 pm ranjith kumar wrote:
> Hi,
> 
> I  have implemented client and server programs using udp
> protocol(files are attached).
> UDP packet size is 500bytes.
> 
> I want to read these 500bytes in two calls to recvfrom(). First time
> reading 100bytes and second time 400bytes.
> How to do this?
> 
> When I tried to change the third argument of recvfrom(size_t len),
> from 500 to 100, first 100bytes are read correctly.
> But when I call recvfrom() second time with len=400, it is reading the
> first 400bytes of "next udp packet".
> Why? Isn't it possible to read one udp packet in two calls to
> recvfrom()/read()????
> 
> Thanks in advance.
> 
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