SCTP: API to add a sub-connection

This patch adds an API to add a sub-connection following a SRC/DST IP
mapping as required by the RFC4960.
At the same time, it changes the way the next available sub-connection
is being calculated: rather than having an index in the parent
connection which is prone to many issues at run-time, the next available
sub-connection is being calculated by looking at the state of the set
sub-connections and if marked as DOWN it means that is an available slot
to be used.

Change-Id: I662be6a247bfbbe8bf9aaf3f485183c07ef862fe
Signed-off-by: Marco Varlese <marco.varlese@suse.com>

1 files changed, 26 insertions, 6 deletions

diff --git a/src/vnet/sctp/sctp.h b/src/vnet/sctp/sctp.h
index 815ca172adb..487ff9e4824 100644
--- a/src/vnet/sctp/sctp.h
+++ b/src/vnet/sctp/sctp.h
@@ -235,8 +235,6 @@ typedef struct _sctp_connection
 
   sctp_options_t snd_opts;
 
-  u8 next_avail_sub_conn; /**< Represent the index of the next free slot in sub_conn */
-
   u8 forming_association_changed; /**< This is a flag indicating whether the original association has been modified during
   	  	  	  	  the life-span of the association itself. For instance, a new sub-connection might have been added. */
 
@@ -245,10 +243,17 @@ typedef struct _sctp_connection
 typedef void (sctp_timer_expiration_handler) (u32 conn_index, u32 timer_id);
 
 sctp_connection_t *sctp_connection_new (u8 thread_index);
-void sctp_sub_connection_add_ip4 (u8 thread_index,
-				  sctp_ipv4_addr_param_t * ipv4_addr);
-void sctp_sub_connection_add_ip6 (u8 thread_index,
-				  sctp_ipv6_addr_param_t * ipv6_addr);
+
+u8
+sctp_sub_connection_add_ip4 (vlib_main_t * vm,
+			     ip4_address_t * lcl_addr,
+			     ip4_address_t * rmt_addr);
+
+u8
+sctp_sub_connection_add_ip6 (vlib_main_t * vm,
+			     ip6_address_t * lcl_addr,
+			     ip6_address_t * rmt_addr);
+
 void sctp_connection_close (sctp_connection_t * sctp_conn);
 void sctp_connection_cleanup (sctp_connection_t * sctp_conn);
 void sctp_connection_del (sctp_connection_t * sctp_conn);
@@ -307,6 +312,8 @@ void sctp_prepare_heartbeat_ack_chunk (sctp_connection_t * sctp_conn, u8 idx,
 
 u16 sctp_check_outstanding_data_chunks (sctp_connection_t * sctp_conn);
 
+void sctp_api_reference (void);
+
 #define IP_PROTOCOL_SCTP	132
 
 /** SSCTP FSM state definitions as per RFC4960. */
@@ -830,6 +837,19 @@ vlib_buffer_push_sctp (vlib_buffer_t * b, u16 sp_net, u16 dp_net,
 					  sctp_hdr_opts_len);
 }
 
+always_inline u8
+sctp_next_avail_subconn (sctp_connection_t * sctp_conn)
+{
+  u8 i;
+
+  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
+    {
+      if (sctp_conn->sub_conn[i].state == SCTP_SUBCONN_STATE_DOWN)
+	return i;
+    }
+  return MAX_SCTP_CONNECTIONS;
+}
+
 always_inline void
 update_smallest_pmtu_idx (sctp_connection_t * sctp_conn)
 {