Hi Baruch, On Fri, Nov 16, 2018 at 09:30:33AM +0200, Baruch Siach wrote: > Commit 672accf1530 (include: update kernel netfilter header files) > updated linux/netfilter.h and brought with it the update from kernel > commit a263653ed798 (netfilter: don't pull include/linux/netfilter.h > from netns headers). This triggers conflict of headers that is fixed in > kernel commit 279c6c7fa64f (api: fix compatibility of linux/in.h with > netinet/in.h) included in kernel version 4.2. For earlier kernel headers > we need a workaround that prevents the headers conflict. > > Fixes the following build failure: > > In file included from .../sysroot/usr/include/netinet/ip.h:25:0, > from ../include/libiptc/ipt_kernel_headers.h:8, > from ../include/libiptc/libiptc.h:6, > from libip4tc.c:29: > .../sysroot/usr/include/linux/in.h:26:3: error: redeclaration of enumerator ‘IPPROTO_IP’ > IPPROTO_IP = 0, /* Dummy protocol for TCP */ > ^ > .../sysroot/usr/include/netinet/in.h:33:5: note: previous definition of ‘IPPROTO_IP’ was here > IPPROTO_IP = 0, /* Dummy protocol for TCP. */ > ^~~~~~~~~~ > > Cc: Florian Westphal <fw@xxxxxxxxx> > Signed-off-by: Baruch Siach <baruch@xxxxxxxxxx> > --- > include/linux/netfilter.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h > index c3f087ac680c..bacf8cd92116 100644 > --- a/include/linux/netfilter.h > +++ b/include/linux/netfilter.h > @@ -3,7 +3,9 @@ > > #include <linux/types.h> > > +#ifndef _NETINET_IN_H > #include <linux/in.h> > +#endif This is updating a cached copy of the kernel headers, we basically copy kernel headers and place in the userspace tree to make sure that iptables compiles standalone, without the need for kernel-headers to be installed in the system in order to simplify building process. I would like we don't have to modify this cached copy, so if you can find a way to update the userspace C files without touching the cached copy of the kernel header, that would be great. My concern is that this little tweak will go away once we update the cached copy anytime soon in the future. Thanks.
