[SCTP]: extend exported data in /proc/net/sctp/assoc

RFC 3873 specifies several MIB objects that can't be obtained by the
current data set exported by /proc/sys/net/sctp/assoc.  This patch
adds the missing pieces of data that allow us to compute all the
objects in the sctpAssocTable object.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 9c827a7..8966599 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1661,6 +1661,9 @@
 	/* Transport to which SHUTDOWN chunk was last sent.  */
 	struct sctp_transport *shutdown_last_sent_to;
 
+	/* How many times have we resent a SHUTDOWN */
+	int shutdown_retries;
+
 	/* Transport to which INIT chunk was last sent.  */
 	struct sctp_transport *init_last_sent_to;
 
@@ -1695,6 +1698,11 @@
 	 */
 	__u16 unack_data;
 
+	/* The total number of data chunks that we've had to retransmit
+	 * as the result of a T3 timer expiration
+	 */
+	__u32 rtx_data_chunks;
+
 	/* This is the association's receive buffer space.  This value is used
 	 * to set a_rwnd field in an INIT or a SACK chunk.
 	 */