Musl defines its own struct ethhdr and thus defines __UAPI_DEF_ETHHDR to
zero. To avoid struct redefinition errors, user space is therefore
supposed to include netinet/if_ether.h before (or instead of)
linux/if_ether.h. To relieve them from this burden, include the libc
header here if not building for kernel space.

Reported-by: Alyssa Ross <hi@alyssa.is>
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
Changes since v1:
- Adjust to previously applied 0b3877bec78b ("netfilter: uapi: Use UAPI definition of INT_MAX and INT_MIN")
---
 include/uapi/linux/netfilter_bridge.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/uapi/linux/netfilter_bridge.h b/include/uapi/linux/netfilter_bridge.h
index f6e8d1e05c97..758de72b2764 100644
--- a/include/uapi/linux/netfilter_bridge.h
+++ b/include/uapi/linux/netfilter_bridge.h
@@ -5,6 +5,10 @@
 /* bridge-specific defines for netfilter. 
  */
 
+#ifndef __KERNEL__
+#include <netinet/if_ether.h>	/* for __UAPI_DEF_ETHHDR if defined */
+#endif
+
 #include <linux/in.h>
 #include <linux/netfilter.h>
 #include <linux/if_ether.h>
-- 
2.51.0