Data corruption when using TCP sockets

Data corruption when using TCP sockets

[madanagopal]

hai,
   We have a socket application in C which connects to a Java application 
through TCP sockets. We use read() system call to read from the socket. 
The Java application sends more than 20000 bytes of data sometimes. In the 
C program, we read those bytes as Type,Length,Value fields where a 
separate read() call is used for each field. This sometimes creates a data 
corruption while it works other times.
   We observe that the first 16384 bytes get read properly. Extra byte or 
bytes get added in the 16385 th location and this shifts the bytes from 
16385 onwards. Because of this our C program gets confused and we are 
forced to reopen the socket. This is not predictable. Suddenly this 
problem occurs. Is this an already known issue and if so what 
is it? How to solve it?
   We are running both the applications in the same machine which runs 
Red Hat Linux release 7.2 and its kernel version is 2.4.7-10

Re: Data corruption when using TCP sockets

[Benjamin LaHaise]

That kernel is beyond ancient -- a 2.4.9 errata kernel was released on 
the day that Red Hat 7.2 shipped.  It is known buggy and superceeded by 
many kernels with substantial bugfixes.

		-ben

On Fri, Dec 02, 2005 at 05:05:28PM +0530, madanagopal wrote:
> hai,
>    We have a socket application in C which connects to a Java application 
> through TCP sockets. We use read() system call to read from the socket. 
> The Java application sends more than 20000 bytes of data sometimes. In the 
> C program, we read those bytes as Type,Length,Value fields where a 
> separate read() call is used for each field. This sometimes creates a data 
> corruption while it works other times.
>    We observe that the first 16384 bytes get read properly. Extra byte or 
> bytes get added in the 16385 th location and this shifts the bytes from 
> 16385 onwards. Because of this our C program gets confused and we are 
> forced to reopen the socket. This is not predictable. Suddenly this 
> problem occurs. Is this an already known issue and if so what 
> is it? How to solve it?
>    We are running both the applications in the same machine which runs 
> Red Hat Linux release 7.2 and its kernel version is 2.4.7-10
> -
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Re: Data corruption when using TCP sockets

[madanagopal]

hai,
   Sorry to ask again. Was this exact problem noticed and fixed in some 
kernel version? If so which version is it? If it is not possible to get 
that info, which version should we use and are we guaranteed that this 
problem will not be present in it?


> That kernel is beyond ancient -- a 2.4.9 errata kernel was released on 
> the day that Red Hat 7.2 shipped.  It is known buggy and superceeded by 
> many kernels with substantial bugfixes.
> 
> 		-ben
> 
> On Fri, Dec 02, 2005 at 05:05:28PM +0530, madanagopal wrote:
> > hai,
> >    We have a socket application in C which connects to a Java application 
> > through TCP sockets. We use read() system call to read from the socket. 
> > The Java application sends more than 20000 bytes of data sometimes. In the 
> > C program, we read those bytes as Type,Length,Value fields where a 
> > separate read() call is used for each field. This sometimes creates a data 
> > corruption while it works other times.
> >    We observe that the first 16384 bytes get read properly. Extra byte or 
> > bytes get added in the 16385 th location and this shifts the bytes from 
> > 16385 onwards. Because of this our C program gets confused and we are 
> > forced to reopen the socket. This is not predictable. Suddenly this 
> > problem occurs. Is this an already known issue and if so what 
> > is it? How to solve it?
> >    We are running both the applications in the same machine which runs 
> > Red Hat Linux release 7.2 and its kernel version is 2.4.7-10
> > -
> > To unsubscribe from this list: send the line "unsubscribe netdev" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

Re: Data corruption when using TCP sockets

[Benjamin LaHaise]

On Fri, Dec 02, 2005 at 08:31:01PM +0530, madanagopal wrote:
> hai,
>    Sorry to ask again. Was this exact problem noticed and fixed in some 
> kernel version? If so which version is it? If it is not possible to get 
> that info, which version should we use and are we guaranteed that this 
> problem will not be present in it?

It certainly isn't a known problem with any recent 2.4 or 2.6 kernels.

		-ben