X25: Enable setting of cause and diagnostic fields

Adds SIOCX25SCAUSEDIAG, allowing X.25 programs to set the cause and
diagnostic fields.

Normally used to indicate status upon closing connections.

Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/x25.h b/include/linux/x25.h
index d035e4e..6450a7f 100644
--- a/include/linux/x25.h
+++ b/include/linux/x25.h
@@ -25,6 +25,7 @@
 #define SIOCX25SENDCALLACCPT    (SIOCPROTOPRIVATE + 9)
 #define SIOCX25GDTEFACILITIES (SIOCPROTOPRIVATE + 10)
 #define SIOCX25SDTEFACILITIES (SIOCPROTOPRIVATE + 11)
+#define SIOCX25SCAUSEDIAG	(SIOCPROTOPRIVATE + 12)
 
 /*
  *	Values for {get,set}sockopt.