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Subject: Re: Redefinition of struct in6_addr in <netinet/in.h> and
 <linux/in6.h>
From: Cong Wang <amwang@redhat.com>
To: Jike Song <albcamus@gmail.com>
Cc: David Miller <davem@davemloft.net>, vapier@gentoo.org,
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Date: Thu, 17 Jan 2013 14:59:13 +0800
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On Thu, 2013-01-17 at 11:55 +0800, Jike Song wrote:
> On Thu, Jan 17, 2013 at 2:59 AM, David Miller <davem@davemloft.net> wrote:
> 
> >
> > When GLIBC doesn't provide it's own definition of some networking
> > macros or interfaces that the kernel provides, people include the
> > kernel header.
> >
> 
> Recently I got a problem when copying a structure from kernel to userspace,
> after debugging I found:
> 
> kernel:   include/linux/inet.h
> 
> #define INET6_ADDRSTRLEN        (48)
> 
> glibc:  /usr/include/netinet/in.h
> 
> #define INET6_ADDRSTRLEN 46
> 
> 
> Any reason to differentiate them from each other?
> 

I see no reason, even although I don't know why it is 46 instead of 40.

But include/linux/inet.h is not exported to user-space, AFAIK.