[SCTP]: Implement SCTP-AUTH initializations.

The patch initializes AUTH related members of the generic SCTP
structures and provides a way to enable/disable auth extension.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 3ec8b12b..4e6b59e 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -1185,6 +1185,9 @@
 	/* Enable PR-SCTP by default. */
 	sctp_prsctp_enable = 1;
 
+	/* Disable AUTH by default. */
+	sctp_auth_enable = 0;
+
 	sctp_sysctl_register();
 
 	INIT_LIST_HEAD(&sctp_address_families);