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

From: Dmitry V. Levin
Date: Mon Feb 20 2017 - 06:58:53 EST


Include <sys/socket.h> (guarded by ifndef __KERNEL__) to fix
the following linux/if.h userspace compilation errors:

/usr/include/linux/if.h:234:19: error: field 'ifru_addr' has incomplete type
struct sockaddr ifru_addr;
/usr/include/linux/if.h:235:19: error: field 'ifru_dstaddr' has incomplete type
struct sockaddr ifru_dstaddr;
/usr/include/linux/if.h:236:19: error: field 'ifru_broadaddr' has incomplete type
struct sockaddr ifru_broadaddr;
/usr/include/linux/if.h:237:19: error: field 'ifru_netmask' has incomplete type
struct sockaddr ifru_netmask;
/usr/include/linux/if.h:238:20: error: field 'ifru_hwaddr' has incomplete type
struct sockaddr ifru_hwaddr;

This also fixes userspace compilation of the following uapi headers:
linux/atmbr2684.h
linux/gsmmux.h
linux/if_arp.h
linux/if_bonding.h
linux/if_frad.h
linux/if_pppox.h
linux/if_tunnel.h
linux/netdevice.h
linux/route.h
linux/wireless.h

As no uapi header provides a definition of struct sockaddr, inclusion
of <sys/socket.h> seems to be the most conservative and the only safe
fix available.

All current users of <linux/if.h> are very likely to be including
<sys/socket.h> already because the latter is the sole provider
of struct sockaddr definition in libc, so adding a uapi header
with a definition of struct sockaddr would create a potential
conflict with <sys/socket.h>.

Replacing struct sockaddr in the definition of struct ifreq with
a different type would create a potential incompatibility with current
users of struct ifreq who might rely on ifru_addr et al members being
of type struct sockaddr.

Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
---
include/uapi/linux/if.h | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h
index 1158a04..259617a 100644
--- a/include/uapi/linux/if.h
+++ b/include/uapi/linux/if.h
@@ -24,6 +24,10 @@
#include <linux/socket.h> /* for "struct sockaddr" et al */
#include <linux/compiler.h> /* for "__user" et al */

+#ifndef __KERNEL__
+#include <sys/socket.h> /* for struct sockaddr. */
+#endif
+
#if __UAPI_DEF_IF_IFNAMSIZ
#define IFNAMSIZ 16
#endif /* __UAPI_DEF_IF_IFNAMSIZ */
--
ldv