udp/session: refactor to support dgram mode

- adds session layer support for datagram based protocols
- updates udp to work in pure connectionless and datagram mode. The
  existing connected mode is now 'accessible' for apps as a dummy UDPC,
  as in, connected udp, protocol.
- updates udp_echo, echo client, echo server code to work in datagram
  mode.

Change-Id: I2960c0d2d246cb166005f545794ec31fe0d546dd
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index 1c46e786e13..68bbd59098e 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -445,13 +445,9 @@ application_start_listen (application_t * srv, session_endpoint_t * sep,
   s = listen_session_new (0, sst);
   s->app_index = srv->index;
 
-  if (stream_session_listen (s, sep))
-    goto err;
-
   /* Allocate segment manager. All sessions derived out of a listen session
    * have fifos allocated by the same segment manager. */
-  sm = application_alloc_segment_manager (srv);
-  if (sm == 0)
+  if (!(sm = application_alloc_segment_manager (srv)))
     goto err;
 
   /* Add to app's listener table. Useful to find all child listeners
@@ -459,6 +455,13 @@ application_start_listen (application_t * srv, session_endpoint_t * sep,
   handle = listen_session_get_handle (s);
   hash_set (srv->listeners_table, handle, segment_manager_index (sm));
 
+  if (stream_session_listen (s, sep))
+    {
+      segment_manager_del (sm);
+      hash_unset (srv->listeners_table, handle);
+      goto err;
+    }
+
   *res = handle;
   return 0;