build: fix missing symbol for old kernel headers (#3530)

Fix issue where IN6_ADDR_GEN_MODE_STABLE_PRIVACY is undefined but
IFLA_INET6_ADDR_GEN_MODE is defined and thus the former does not get
fixed in missing.h. This occurs with kernel headers new enough to have
the IFLA_INET6_ADDR_GEN_MODE but old enough to not yet have
IN6_ADDR_GEN_MODE_STABLE_PRIVACY (e.g. 3.18).

diff --git a/src/basic/missing.h b/src/basic/missing.h
index c33439ddea8cf48af702d80570e6e42c676b0ac6..4a3b5ecb5b8543a82d3246af47d9564125cc92ba 100644 (file)
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -582,6 +582,9 @@ struct btrfs_ioctl_quota_ctl_args {
 
 #define IN6_ADDR_GEN_MODE_EUI64 0
 #define IN6_ADDR_GEN_MODE_NONE 1
+#endif
+
+#if !HAVE_DECL_IN6_ADDR_GEN_MODE_STABLE_PRIVACY
 #define IN6_ADDR_GEN_MODE_STABLE_PRIVACY 2
 #endif