uapi/if_ether.h: prevent redefinition of struct ethhdr

commit 6926e041a8920c8ec27e4e155efa760aa01551fd upstream.

Musl provides its own ethhdr struct definition. Add a guard to prevent
its definition of the appropriate musl header has already been included.

glibc does not implement this header, but when glibc will implement this
they can just define __UAPI_DEF_ETHHDR 0 to make it work with the
kernel.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/uapi/linux/if_ether.h b/include/uapi/linux/if_ether.h
index 064d2026ab38899032bb5090830f0c9b3b51747a..cb490cd9376fb78f5c6d7ad67e57241b1159d7e3 100644 (file)
--- a/include/uapi/linux/if_ether.h
+++ b/include/uapi/linux/if_ether.h
@@ -22,6 +22,7 @@
 #define _UAPI_LINUX_IF_ETHER_H
 
 #include <linux/types.h>
+#include <linux/libc-compat.h>
 
 /*
  *     IEEE 802.3 Ethernet magic constants.  The frame sizes omit the preamble
@@ -136,11 +137,13 @@
  *     This is an Ethernet frame header.
  */
 
+#if __UAPI_DEF_ETHHDR
 struct ethhdr {
        unsigned char   h_dest[ETH_ALEN];       /* destination eth addr */
        unsigned char   h_source[ETH_ALEN];     /* source ether addr    */
        __be16          h_proto;                /* packet type ID field */
 } __attribute__((packed));
+#endif
 
 
 #endif /* _UAPI_LINUX_IF_ETHER_H */

diff --git a/include/uapi/linux/libc-compat.h b/include/uapi/linux/libc-compat.h
index e4f048ee7043d196a0948c9dfc520b78082c6e54..5da44c571cddaf84f4960dc889eee02ed68ec2d3 100644 (file)
--- a/include/uapi/linux/libc-compat.h
+++ b/include/uapi/linux/libc-compat.h
@@ -184,4 +184,10 @@
 
 #endif /* __GLIBC__ */
 
+/* Definitions for if_ether.h */
+/* allow libcs like musl to deactivate this, glibc does not implement this. */
+#ifndef __UAPI_DEF_ETHHDR
+#define __UAPI_DEF_ETHHDR              1
+#endif
+
 #endif /* _UAPI_LIBC_COMPAT_H */