net: implement a SO_DOMAIN getsockoption
This sockopt goes in line with SO_TYPE and SO_PROTOCOL. It makes it
possible for userspace programs to pass around file descriptors — I
am referring to arguments-to-functions, but it may even work for the
fd passing over UNIX sockets — without needing to also pass the
auxiliary information (PF_INET6/IPPROTO_TCP).
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/s390/include/asm/socket.h b/arch/s390/include/asm/socket.h
index 65baa9a..e42df89 100644
--- a/arch/s390/include/asm/socket.h
+++ b/arch/s390/include/asm/socket.h
@@ -66,5 +66,6 @@
#define SCM_TIMESTAMPING SO_TIMESTAMPING
#define SO_PROTOCOL 38
+#define SO_DOMAIN 39
#endif /* _ASM_SOCKET_H */