Fix userland build failure in linux/if_tunnel.h]

Hello all,

As suggested, reposting the message in this list. Could someone please comment? Original message here:
http://lkml.org/lkml/2009/6/18/223

Thanks in advance,
Sergei

-------- Original Message --------
Subject: Re: [PATCH] Fix userland build failure in linux/if_tunnel.h
Date: Fri, 7 Aug 2009 15:31:06 +0400
From: Sergei Poselenov <[email protected]>
Organisation: Emcraft Systems
To: [email protected]
CC: [email protected]
References: <[email protected]>

Hello all,

Unfortunately, received no replies, but the problem still persists.

Probably, I was unclear describing the issue. It is not the busybox build problem - any application including exported linux/if_tunnel.h could fail the linkage because of unresolved __cpu_to_be16().

Here is a reduced testcase program:

#include <netinet/ip.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <asm/types.h>

#include <linux/if_tunnel.h>

void foo(void);
void foo(void)

{
	int a = GRE_CSUM;
}

How to reproduce:

bash> arm-linux-gcc -c t.c
bash> nm -n t.o

        U __cpu_to_be16

00000000 t $a
00000000 T foo

As you see, __cpu_to_be16 is undefined, so linking will fail. Adding <asm/byteorder.h> to if_tunnel.h, as I suggested, fixes the problem.

Thanks for any comments,
Sergei