[PATCH v2] uapi: fix linux/if_pppol2tp.h userspace compilation errors

From: Dmitry V. Levin
Date: Tue Feb 14 2017 - 21:23:34 EST

Because of <linux/libc-compat.h> interface limitations, <netinet/in.h>
provided by libc cannot be included after <linux/in.h>, therefore any
header that includes <netinet/in.h> cannot be included after <linux/in.h>.

Change uapi/linux/l2tp.h, the last uapi header that includes
<netinet/in.h>, to include <linux/in.h> and <linux/in6.h> instead of
<netinet/in.h> and use __SOCK_SIZE__ instead of sizeof(struct sockaddr)
the same way as uapi/linux/in.h does, to fix linux/if_pppol2tp.h userspace
compilation errors like this:

In file included from /usr/include/linux/l2tp.h:12:0,
from /usr/include/linux/if_pppol2tp.h:21,
/usr/include/netinet/in.h:31:8: error: redefinition of 'struct in_addr'

Fixes: 47c3e7783be4 ("net: l2tp: deprecate PPPOL2TP_MSG_* in favour of L2TP_MSG_*")
Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
v2: change uapi/linux/l2tp.h to fix <linux/if_pppol2tp.h>

include/uapi/linux/l2tp.h | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/l2tp.h b/include/uapi/linux/l2tp.h
index 85ddb74..b23c191 100644
--- a/include/uapi/linux/l2tp.h
+++ b/include/uapi/linux/l2tp.h
@@ -9,9 +9,8 @@

#include <linux/types.h>
#include <linux/socket.h>
-#ifndef __KERNEL__
-#include <netinet/in.h>
+#include <linux/in.h>
+#include <linux/in6.h>

#define IPPROTO_L2TP 115

@@ -31,7 +30,7 @@ struct sockaddr_l2tpip {
__u32 l2tp_conn_id; /* Connection ID of tunnel */

/* Pad to size of `struct sockaddr'. */
- unsigned char __pad[sizeof(struct sockaddr) -
+ unsigned char __pad[__SOCK_SIZE__ -
sizeof(__kernel_sa_family_t) -
sizeof(__be16) - sizeof(struct in_addr) -