Merge branch 'baseline' into refs/top-bases/tschwinge/Roger_Whittaker

1 files changed, 12 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/bits/in.h b/sysdeps/unix/sysv/linux/bits/in.h
index e959b33eac..d763ce9fc2 100644
--- a/sysdeps/unix/sysv/linux/bits/in.h
+++ b/sysdeps/unix/sysv/linux/bits/in.h
@@ -21,6 +21,18 @@
 # error "Never use <bits/in.h> directly; include <netinet/in.h> instead."
 #endif
 
+/* If the application has already included linux/in6.h from a linux-based
+   kernel then we will not define the IPv6 IPPROTO_* defines, in6_addr (nor the
+   defines), sockaddr_in6, or ipv6_mreq.  The ABI used by the linux-kernel and
+   glibc match exactly.  Neither the linux kernel nor glibc should break this
+   ABI without coordination.  */
+#ifdef _UAPI_LINUX_IN6_H
+/* This is not quite the same API since the kernel always defines s6_addr16 and
+   s6_addr32. This is not a violation of POSIX since POSIX says "at least the
+   following member" and that holds true.  */
+# define __USE_KERNEL_IPV6_DEFS
+#endif
+
 /* Options for use with `getsockopt' and `setsockopt' at the IP level.
    The first word in the comment at the right is the data type used;
    "bool" means a boolean value stored in an `int'.  */