fix musl compatibility

Let configure include sys/if_tun.h when testing for netinet/if_ether.h
to detect the Kernel/libc header conflict on musl.

After this patch, configure will correctly detect netinet/if_ether.h as
unusable and the subsequent compilation will not attempt to use it.

diff --git a/src/have.h b/src/have.h
index e83f98f..69d5100 100644 (file)
--- a/src/have.h
+++ b/src/have.h
@@ -207,4 +207,8 @@
 #include <resolv.h>
 #endif
 
+#ifdef HAVE_LINUX_IF_TUN_H
+#include <linux/if_tun.h>
+#endif
+
 #endif /* __TINC_SYSTEM_H__ */