From: Dmitry V. Levin <ldv@xxxxxxxxxxxx> commit a725eb15db80643a160310ed6bcfd6c5a6c907f2 upstream. 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> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/uapi/linux/l2tp.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- 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> -#endif +#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) - sizeof(__u32)];