session: extend connect api for internal apps

Change-Id: Ie4c5cfc4c97acb321a46b4df589dc44de1b616ba
Signed-off-by: Florin Coras <fcoras@cisco.com>

12 files changed, 397 insertions, 119 deletions

diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index 90c067d6d31..1d7b3ad1125 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -715,7 +715,7 @@ app_worker_stop_listen (app_worker_t * app_wrk, session_handle_t handle)
  */
 int
 application_start_listen (application_t * app,
-			  session_endpoint_extended_t * sep_ext,
+			  session_endpoint_cfg_t * sep_ext,
 			  session_handle_t * res)
 {
   app_listener_t *app_listener;
@@ -1055,7 +1055,7 @@ application_start_stop_proxy_fib_proto (application_t * app, u8 fib_proto,
 {
   app_namespace_t *app_ns = app_namespace_get (app->ns_index);
   u8 is_ip4 = (fib_proto == FIB_PROTOCOL_IP4);
-  session_endpoint_extended_t sep = SESSION_ENDPOINT_EXT_NULL;
+  session_endpoint_cfg_t sep = SESSION_ENDPOINT_CFG_NULL;
   transport_connection_t *tc;
   app_worker_t *app_wrk;
   stream_session_t *s;
@@ -1408,7 +1408,7 @@ application_local_listen_session_free (application_t * app,
 
 int
 application_start_local_listen (application_t * app,
-				session_endpoint_extended_t * sep_ext,
+				session_endpoint_cfg_t * sep_ext,
 				session_handle_t * handle)
 {
   app_listener_t *app_listener;
diff --git a/src/vnet/session/application.h b/src/vnet/session/application.h
index e2f2279d77f..3888cf7f463 100644
--- a/src/vnet/session/application.h
+++ b/src/vnet/session/application.h
@@ -243,7 +243,7 @@ int app_worker_lock_and_send_event (app_worker_t * app, stream_session_t * s,
 clib_error_t *vnet_app_worker_add_del (vnet_app_worker_add_del_args_t * a);
 
 int application_start_listen (application_t * app,
-			      session_endpoint_extended_t * tep,
+			      session_endpoint_cfg_t * tep,
 			      session_handle_t * handle);
 int application_stop_listen (u32 app_index, u32 app_or_wrk,
 			     session_handle_t handle);
@@ -295,7 +295,7 @@ local_session_t *application_get_local_session_from_handle (session_handle_t
 local_session_t
   * application_get_local_listen_session_from_handle (session_handle_t lh);
 int application_start_local_listen (application_t * server,
-				    session_endpoint_extended_t * sep,
+				    session_endpoint_cfg_t * sep,
 				    session_handle_t * handle);
 int application_stop_local_listen (u32 app_index, u32 app_or_wrk,
 				   session_handle_t lh);
diff --git a/src/vnet/session/application_interface.c b/src/vnet/session/application_interface.c
index d35a8293723..1f5c6ff5a31 100644
--- a/src/vnet/session/application_interface.c
+++ b/src/vnet/session/application_interface.c
@@ -137,11 +137,11 @@ api_parse_session_handle (u64 handle, u32 * session_index, u32 * thread_index)
 }
 
 static void
-session_endpoint_update_for_app (session_endpoint_extended_t * sep,
-				 application_t * app)
+session_endpoint_update_for_app (session_endpoint_cfg_t * sep,
+				 application_t * app, u8 is_connect)
 {
   app_namespace_t *app_ns;
-  u32 ns_index;
+  u32 ns_index, fib_index;
 
   ns_index = app->ns_index;
 
@@ -156,15 +156,29 @@ session_endpoint_update_for_app (session_endpoint_extended_t * sep,
       ns_index = owner_app->ns_index;
     }
   app_ns = app_namespace_get (ns_index);
-  if (app_ns)
+  if (!app_ns)
+    return;
+
+  /* Ask transport and network to bind to/connect using local interface
+   * that "supports" app's namespace. This will fix our local connection
+   * endpoint.
+   */
+  fib_index = sep->is_ip4 ? app_ns->ip4_fib_index : app_ns->ip6_fib_index;
+  sep->peer.fib_index = fib_index;
+  sep->fib_index = fib_index;
+
+  if (!is_connect)
     {
-      /* Ask transport and network to bind to/connect using local interface
-       * that "supports" app's namespace. This will fix our local connection
-       * endpoint.
-       */
       sep->sw_if_index = app_ns->sw_if_index;
-      sep->fib_index =
-	sep->is_ip4 ? app_ns->ip4_fib_index : app_ns->ip6_fib_index;
+    }
+  else
+    {
+      if (app_ns->sw_if_index != APP_NAMESPACE_INVALID_INDEX
+	  && sep->peer.sw_if_index != ENDPOINT_INVALID_INDEX
+	  && sep->peer.sw_if_index != app_ns->sw_if_index)
+	clib_warning ("Local sw_if_index different from app ns sw_if_index");
+
+      sep->peer.sw_if_index = app_ns->sw_if_index;
     }
 }
 
@@ -185,7 +199,7 @@ vnet_bind_inline (vnet_bind_args_t * a)
   app_wrk = application_get_worker (app, a->wrk_map_index);
   a->sep_ext.app_wrk_index = app_wrk->wrk_index;
 
-  session_endpoint_update_for_app (&a->sep_ext, app);
+  session_endpoint_update_for_app (&a->sep_ext, app, 0 /* is_connect */ );
   if (!session_endpoint_in_ns (&a->sep))
     return VNET_API_ERROR_INVALID_VALUE_2;
 
@@ -278,7 +292,7 @@ application_connect (vnet_connect_args_t * a)
     return VNET_API_ERROR_INVALID_VALUE;
 
   client = application_get (a->app_index);
-  session_endpoint_update_for_app (&a->sep_ext, client);
+  session_endpoint_update_for_app (&a->sep_ext, client, 1 /* is_connect */ );
   client_wrk = application_get_worker (client, a->wrk_map_index);
 
   /*
@@ -368,8 +382,7 @@ global_scope:
 uword
 unformat_vnet_uri (unformat_input_t * input, va_list * args)
 {
-  session_endpoint_extended_t *sep = va_arg (*args,
-					     session_endpoint_extended_t *);
+  session_endpoint_cfg_t *sep = va_arg (*args, session_endpoint_cfg_t *);
   u32 transport_proto = 0, port;
 
   if (unformat (input, "%U://%U/%d", unformat_transport_proto,
@@ -411,10 +424,10 @@ unformat_vnet_uri (unformat_input_t * input, va_list * args)
 }
 
 static u8 *cache_uri;
-static session_endpoint_extended_t *cache_sep;
+static session_endpoint_cfg_t *cache_sep;
 
 int
-parse_uri (char *uri, session_endpoint_extended_t * sep)
+parse_uri (char *uri, session_endpoint_cfg_t * sep)
 {
   unformat_input_t _input, *input = &_input;
 
@@ -548,7 +561,7 @@ vnet_application_detach (vnet_app_detach_args_t * a)
 int
 vnet_bind_uri (vnet_bind_args_t * a)
 {
-  session_endpoint_extended_t sep = SESSION_ENDPOINT_EXT_NULL;
+  session_endpoint_cfg_t sep = SESSION_ENDPOINT_CFG_NULL;
   int rv;
 
   rv = parse_uri (a->uri, &sep);
@@ -562,7 +575,7 @@ vnet_bind_uri (vnet_bind_args_t * a)
 int
 vnet_unbind_uri (vnet_unbind_args_t * a)
 {
-  session_endpoint_extended_t sep = SESSION_ENDPOINT_EXT_NULL;
+  session_endpoint_cfg_t sep = SESSION_ENDPOINT_CFG_NULL;
   stream_session_t *listener;
   u32 table_index;
   int rv;
@@ -585,7 +598,7 @@ vnet_unbind_uri (vnet_unbind_args_t * a)
 clib_error_t *
 vnet_connect_uri (vnet_connect_args_t * a)
 {
-  session_endpoint_extended_t sep = SESSION_ENDPOINT_EXT_NULL;
+  session_endpoint_cfg_t sep = SESSION_ENDPOINT_CFG_NULL;
   int rv;
 
   /* Parse uri */
diff --git a/src/vnet/session/application_interface.h b/src/vnet/session/application_interface.h
index c8ceb4e07a5..2da69fcab92 100644
--- a/src/vnet/session/application_interface.h
+++ b/src/vnet/session/application_interface.h
@@ -39,7 +39,7 @@ typedef struct _vnet_bind_args_t
 {
   union
   {
-    session_endpoint_extended_t sep_ext;
+    session_endpoint_cfg_t sep_ext;
     session_endpoint_t sep;
     char *uri;
   };
@@ -71,7 +71,7 @@ typedef struct _vnet_connect_args
 {
   union
   {
-    session_endpoint_extended_t sep_ext;
+    session_endpoint_cfg_t sep_ext;
     session_endpoint_t sep;
     char *uri;
   };
diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index 1d421b978c1..9c246a1ad87 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -886,14 +886,14 @@ int
 session_open_cl (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
   transport_connection_t *tc;
-  transport_endpoint_t *tep;
+  transport_endpoint_cfg_t *tep;
   segment_manager_t *sm;
   app_worker_t *app_wrk;
   stream_session_t *s;
   application_t *app;
   int rv;
 
-  tep = session_endpoint_to_transport (rmt);
+  tep = session_endpoint_to_transport_cfg (rmt);
   rv = tp_vfts[rmt->transport_proto].open (tep);
   if (rv < 0)
     {
@@ -924,11 +924,11 @@ int
 session_open_vc (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
   transport_connection_t *tc;
-  transport_endpoint_t *tep;
+  transport_endpoint_cfg_t *tep;
   u64 handle;
   int rv;
 
-  tep = session_endpoint_to_transport (rmt);
+  tep = session_endpoint_to_transport_cfg (rmt);
   rv = tp_vfts[rmt->transport_proto].open (tep);
   if (rv < 0)
     {
@@ -958,11 +958,13 @@ session_open_vc (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 int
 session_open_app (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
-  session_endpoint_extended_t *sep = (session_endpoint_extended_t *) rmt;
+  session_endpoint_cfg_t *sep = (session_endpoint_cfg_t *) rmt;
+  transport_endpoint_cfg_t *tep_cfg = session_endpoint_to_transport_cfg (sep);
+
   sep->app_wrk_index = app_wrk_index;
   sep->opaque = opaque;
 
-  return tp_vfts[rmt->transport_proto].open ((transport_endpoint_t *) sep);
+  return tp_vfts[rmt->transport_proto].open (tep_cfg);
 }
 
 typedef int (*session_open_service_fn) (u32, session_endpoint_t *, u32);
@@ -1004,7 +1006,7 @@ session_open (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
  * @param sep Local endpoint to be listened on.
  */
 int
-session_listen (stream_session_t * ls, session_endpoint_extended_t * sep)
+session_listen (stream_session_t * ls, session_endpoint_cfg_t * sep)
 {
   transport_connection_t *tc;
   transport_endpoint_t *tep;
diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index f0aa36cc1bc..4d46596813f 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -570,7 +570,7 @@ void stream_session_reset_notify (transport_connection_t * tc);
 int stream_session_accept (transport_connection_t * tc, u32 listener_index,
 			   u8 notify);
 int session_open (u32 app_index, session_endpoint_t * tep, u32 opaque);
-int session_listen (stream_session_t * s, session_endpoint_extended_t * sep);
+int session_listen (stream_session_t * s, session_endpoint_cfg_t * sep);
 int session_stop_listen (stream_session_t * s);
 void stream_session_disconnect (stream_session_t * s);
 void stream_session_disconnect_transport (stream_session_t * s);
diff --git a/src/vnet/session/session_api.c b/src/vnet/session/session_api.c
index f0273641e7f..eb33db03f33 100755
--- a/src/vnet/session/session_api.c
+++ b/src/vnet/session/session_api.c
@@ -1290,8 +1290,8 @@ vl_api_connect_sock_t_handler (vl_api_connect_sock_t * mp)
       a->sep.ip = *ip46;
       a->sep.port = mp->port;
       a->sep.transport_proto = mp->proto;
-      a->sep.fib_index = mp->vrf;
-      a->sep.sw_if_index = ENDPOINT_INVALID_INDEX;
+      a->sep.peer.fib_index = mp->vrf;
+      a->sep.peer.sw_if_index = ENDPOINT_INVALID_INDEX;
       if (mp->hostname_len)
 	{
 	  vec_validate (a->sep_ext.hostname, mp->hostname_len - 1);
diff --git a/src/vnet/session/session_test.c b/src/vnet/session/session_test.c
index 8fe1b0d36e0..5c2993e3322 100644
--- a/src/vnet/session/session_test.c
+++ b/src/vnet/session/session_test.c
@@ -45,12 +45,18 @@ dummy_session_reset_callback (stream_session_t * s)
   clib_warning ("called...");
 }
 
+volatile u32 connected_session_index = ~0;
+volatile u32 connected_session_thread = ~0;
 int
 dummy_session_connected_callback (u32 app_index, u32 api_context,
 				  stream_session_t * s, u8 is_fail)
 {
-  clib_warning ("called...");
-  return -1;
+  if (s)
+    {
+      connected_session_index = s->session_index;
+      connected_session_thread = s->thread_index;
+    }
+  return 0;
 }
 
 static u32 dummy_segment_count;
@@ -76,11 +82,15 @@ dummy_session_disconnect_callback (stream_session_t * s)
 }
 
 static u32 dummy_accept;
+volatile u32 accepted_session_index;
+volatile u32 accepted_session_thread;
 
 int
 dummy_session_accept_callback (stream_session_t * s)
 {
   dummy_accept = 1;
+  accepted_session_index = s->session_index;
+  accepted_session_thread = s->thread_index;
   s->session_state = SESSION_STATE_READY;
   return 0;
 }
@@ -119,7 +129,10 @@ session_create_lookpback (u32 table_id, u32 * sw_if_index,
     }
 
   if (table_id != 0)
-    ip_table_bind (FIB_PROTOCOL_IP4, *sw_if_index, table_id, 0);
+    {
+      ip_table_create (FIB_PROTOCOL_IP4, table_id, 0, 0);
+      ip_table_bind (FIB_PROTOCOL_IP4, *sw_if_index, table_id, 0);
+    }
 
   vnet_sw_interface_set_flags (vnet_get_main (), *sw_if_index,
 			       VNET_SW_INTERFACE_FLAG_ADMIN_UP);
@@ -207,6 +220,189 @@ session_test_basic (vlib_main_t * vm, unformat_input_t * input)
   return 0;
 }
 
+static void
+session_add_del_route_via_lookup_in_table (u32 in_table_id, u32 via_table_id,
+					   ip4_address_t * ip, u8 mask,
+					   u8 is_add)
+{
+  fib_route_path_t *rpaths = 0, *rpath;
+  u32 in_fib_index, via_fib_index;
+
+  fib_prefix_t prefix = {
+    .fp_addr.ip4.as_u32 = ip->as_u32,
+    .fp_len = mask,
+    .fp_proto = FIB_PROTOCOL_IP4,
+  };
+
+  via_fib_index = fib_table_find (FIB_PROTOCOL_IP4, via_table_id);
+  if (via_fib_index == ~0)
+    {
+      clib_warning ("couldn't resolve via table id to index");
+      return;
+    }
+  in_fib_index = fib_table_find (FIB_PROTOCOL_IP4, in_table_id);
+  if (in_fib_index == ~0)
+    {
+      clib_warning ("couldn't resolve in table id to index");
+      return;
+    }
+
+  vec_add2 (rpaths, rpath, 1);
+  clib_memset (rpath, 0, sizeof (*rpath));
+  rpath->frp_weight = 1;
+  rpath->frp_fib_index = via_fib_index;
+  rpath->frp_proto = DPO_PROTO_IP4;
+  rpath->frp_sw_if_index = ~0;
+  rpath->frp_flags |= FIB_ROUTE_PATH_DEAG;
+
+  if (is_add)
+    fib_table_entry_path_add2 (in_fib_index, &prefix, FIB_SOURCE_CLI,
+			       FIB_ENTRY_FLAG_NONE, rpath);
+  else
+    fib_table_entry_path_remove2 (in_fib_index, &prefix, FIB_SOURCE_CLI,
+				  rpath);
+  vec_free (rpaths);
+}
+
+static int
+session_test_endpoint_cfg (vlib_main_t * vm, unformat_input_t * input)
+{
+  session_endpoint_cfg_t client_sep = SESSION_ENDPOINT_CFG_NULL;
+  u64 options[APP_OPTIONS_N_OPTIONS], dummy_secret = 1234;
+  u16 dummy_server_port = 1234, dummy_client_port = 5678;
+  session_endpoint_t server_sep = SESSION_ENDPOINT_NULL;
+  u32 server_index, client_index, sw_if_index[2];
+  ip4_address_t intf_addr[3];
+  transport_connection_t *tc;
+  stream_session_t *s;
+  clib_error_t *error;
+  u8 *appns_id;
+
+  /*
+   * Create the loopbacks
+   */
+  intf_addr[0].as_u32 = clib_host_to_net_u32 (0x01010101),
+    session_create_lookpback (0, &sw_if_index[0], &intf_addr[0]);
+
+  intf_addr[1].as_u32 = clib_host_to_net_u32 (0x02020202),
+    session_create_lookpback (1, &sw_if_index[1], &intf_addr[1]);
+
+  session_add_del_route_via_lookup_in_table (0, 1, &intf_addr[1], 32,
+					     1 /* is_add */ );
+  session_add_del_route_via_lookup_in_table (1, 0, &intf_addr[0], 32,
+					     1 /* is_add */ );
+
+  /*
+   * Insert namespace
+   */
+  appns_id = format (0, "appns1");
+  vnet_app_namespace_add_del_args_t ns_args = {
+    .ns_id = appns_id,
+    .secret = dummy_secret,
+    .sw_if_index = sw_if_index[1],
+    .ip4_fib_id = 0,
+    .is_add = 1
+  };
+  error = vnet_app_namespace_add_del (&ns_args);
+  SESSION_TEST ((error == 0), "app ns insertion should succeed: %d",
+		clib_error_get_code (error));
+
+  /*
+   * Attach client/server
+   */
+  clib_memset (options, 0, sizeof (options));
+  options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
+  options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
+
+  vnet_app_attach_args_t attach_args = {
+    .api_client_index = ~0,
+    .options = options,
+    .namespace_id = 0,
+    .session_cb_vft = &dummy_session_cbs,
+    .name = format (0, "session_test_client"),
+  };
+
+  error = vnet_application_attach (&attach_args);
+  SESSION_TEST ((error == 0), "client app attached");
+  client_index = attach_args.app_index;
+  vec_free (attach_args.name);
+
+  attach_args.name = format (0, "session_test_server");
+  attach_args.namespace_id = appns_id;
+  attach_args.options[APP_OPTIONS_NAMESPACE_SECRET] = dummy_secret;
+  error = vnet_application_attach (&attach_args);
+  SESSION_TEST ((error == 0), "server app attached: %U", format_clib_error,
+		error);
+  vec_free (attach_args.name);
+  server_index = attach_args.app_index;
+
+  server_sep.is_ip4 = 1;
+  server_sep.port = dummy_server_port;
+  vnet_bind_args_t bind_args = {
+    .sep = server_sep,
+    .app_index = server_index,
+  };
+  error = vnet_bind (&bind_args);
+  SESSION_TEST ((error == 0), "server bind should work");
+
+  /*
+   * Connect and force lcl ip
+   */
+  client_sep.is_ip4 = 1;
+  client_sep.ip.ip4.as_u32 = clib_host_to_net_u32 (0x02020202);
+  client_sep.port = dummy_server_port;
+  client_sep.peer.is_ip4 = 1;
+  client_sep.peer.ip.ip4.as_u32 = clib_host_to_net_u32 (0x01010101);
+  client_sep.peer.port = dummy_client_port;
+  client_sep.transport_proto = TRANSPORT_PROTO_TCP;
+
+  vnet_connect_args_t connect_args = {
+    .sep_ext = client_sep,
+    .app_index = client_index,
+  };
+
+  error = vnet_connect (&connect_args);
+  SESSION_TEST ((error == 0), "connect should work");
+
+  /* wait for stuff to happen */
+  vlib_process_suspend (vm, 10e-3);
+
+  SESSION_TEST ((connected_session_index != ~0), "session should exist");
+  s = session_get (connected_session_index, connected_session_thread);
+  tc = session_get_transport (s);
+  SESSION_TEST ((tc != 0), "transport should exist");
+  SESSION_TEST ((memcmp (&tc->lcl_ip, &client_sep.peer.ip,
+			 sizeof (tc->lcl_ip)) == 0), "ips should be equal");
+  SESSION_TEST ((tc->lcl_port == dummy_client_port), "ports should be equal");
+
+  /* These sessions, because of the way they're established are pinned to
+   * main thread, even when we have workers and we avoid polling main thread,
+   * i.e., we can't cleanup pending disconnects, so force cleanup for both
+   */
+  stream_session_cleanup (s);
+  s = session_get (accepted_session_index, accepted_session_thread);
+  stream_session_cleanup (s);
+
+  vnet_app_detach_args_t detach_args = {
+    .app_index = server_index,
+  };
+  vnet_application_detach (&detach_args);
+  detach_args.app_index = client_index;
+  vnet_application_detach (&detach_args);
+
+  /* Allow the disconnects to finish before removing the routes. */
+  vlib_process_suspend (vm, 10e-3);
+
+  session_add_del_route_via_lookup_in_table (0, 1, &intf_addr[1], 32,
+					     0 /* is_add */ );
+  session_add_del_route_via_lookup_in_table (1, 0, &intf_addr[0], 32,
+					     0 /* is_add */ );
+
+  session_delete_loopback (sw_if_index[0]);
+  session_delete_loopback (sw_if_index[1]);
+  return 0;
+}
+
 static int
 session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
 {
@@ -1515,6 +1711,8 @@ session_test (vlib_main_t * vm,
 	res = session_test_rules (vm, input);
       else if (unformat (input, "proxy"))
 	res = session_test_proxy (vm, input);
+      else if (unformat (input, "endpt-cfg"))
+	res = session_test_endpoint_cfg (vm, input);
       else if (unformat (input, "all"))
 	{
 	  if ((res = session_test_basic (vm, input)))
@@ -1527,6 +1725,8 @@ session_test (vlib_main_t * vm,
 	    goto done;
 	  if ((res = session_test_proxy (vm, input)))
 	    goto done;
+	  if ((res = session_test_endpoint_cfg (vm, input)))
+	    goto done;
 	}
       else
 	break;
diff --git a/src/vnet/session/stream_session.h b/src/vnet/session/stream_session.h
index 287a8927339..c335c5b833e 100644
--- a/src/vnet/session/stream_session.h
+++ b/src/vnet/session/stream_session.h
@@ -153,8 +153,8 @@ typedef struct local_session_
 } local_session_t;
 
 #define foreach_session_endpoint_fields				\
-    foreach_transport_connection_fields				\
-    _(u8, transport_proto)					\
+  foreach_transport_endpoint_cfg_fields				\
+  _(u8, transport_proto)					\
 
 typedef struct _session_endpoint
 {
@@ -163,7 +163,7 @@ typedef struct _session_endpoint
 #undef _
 } session_endpoint_t;
 
-typedef struct _session_endpoint_extended
+typedef struct _session_endpoint_cfg
 {
 #define _(type, name) type name;
   foreach_session_endpoint_fields
@@ -171,7 +171,7 @@ typedef struct _session_endpoint_extended
   u32 app_wrk_index;
   u32 opaque;
   u8 *hostname;
-} session_endpoint_extended_t;
+} session_endpoint_cfg_t;
 
 #define SESSION_IP46_ZERO			\
 {						\
@@ -179,6 +179,15 @@ typedef struct _session_endpoint_extended
 	{ 0, 0, },				\
     },						\
 }
+
+#define TRANSPORT_ENDPOINT_NULL			\
+{						\
+  .sw_if_index = ENDPOINT_INVALID_INDEX,	\
+  .ip = SESSION_IP46_ZERO,			\
+  .fib_index = ENDPOINT_INVALID_INDEX,		\
+  .is_ip4 = 0,					\
+  .port = 0,					\
+}
 #define SESSION_ENDPOINT_NULL 			\
 {						\
   .sw_if_index = ENDPOINT_INVALID_INDEX,	\
@@ -186,15 +195,17 @@ typedef struct _session_endpoint_extended
   .fib_index = ENDPOINT_INVALID_INDEX,		\
   .is_ip4 = 0,					\
   .port = 0,					\
+  .peer = TRANSPORT_ENDPOINT_NULL,		\
   .transport_proto = 0,				\
 }
-#define SESSION_ENDPOINT_EXT_NULL 		\
+#define SESSION_ENDPOINT_CFG_NULL 		\
 {						\
   .sw_if_index = ENDPOINT_INVALID_INDEX,	\
   .ip = SESSION_IP46_ZERO,			\
   .fib_index = ENDPOINT_INVALID_INDEX,		\
   .is_ip4 = 0,					\
   .port = 0,					\
+  .peer = TRANSPORT_ENDPOINT_NULL,		\
   .transport_proto = 0,				\
   .app_wrk_index = ENDPOINT_INVALID_INDEX,	\
   .opaque = ENDPOINT_INVALID_INDEX,		\
@@ -202,6 +213,8 @@ typedef struct _session_endpoint_extended
 }
 
 #define session_endpoint_to_transport(_sep) ((transport_endpoint_t *)_sep)
+#define session_endpoint_to_transport_cfg(_sep)		\
+  ((transport_endpoint_cfg_t *)_sep)
 
 always_inline u8
 session_endpoint_fib_proto (session_endpoint_t * sep)
diff --git a/src/vnet/session/transport.c b/src/vnet/session/transport.c
index 8cbad0d397f..fefedcae8f2 100644
--- a/src/vnet/session/transport.c
+++ b/src/vnet/session/transport.c
@@ -291,7 +291,7 @@ always_inline transport_endpoint_t *
 transport_endpoint_new (void)
 {
   transport_endpoint_t *tep;
-  pool_get (local_endpoints, tep);
+  pool_get_zero (local_endpoints, tep);
   return tep;
 }
 
@@ -312,6 +312,19 @@ transport_endpoint_cleanup (u8 proto, ip46_address_t * lcl_ip, u16 port)
     }
 }
 
+static void
+transport_endpoint_mark_used (u8 proto, ip46_address_t * ip, u16 port)
+{
+  transport_endpoint_t *tep;
+  clib_spinlock_lock_if_init (&local_endpoints_lock);
+  tep = transport_endpoint_new ();
+  clib_memcpy (&tep->ip, ip, sizeof (*ip));
+  tep->port = port;
+  transport_endpoint_table_add (&local_endpoints_table, proto, tep,
+				tep - local_endpoints);
+  clib_spinlock_unlock_if_init (&local_endpoints_lock);
+}
+
 /**
  * Allocate local port and add if successful add entry to local endpoint
  * table to mark the pair as used.
@@ -319,10 +332,9 @@ transport_endpoint_cleanup (u8 proto, ip46_address_t * lcl_ip, u16 port)
 int
 transport_alloc_local_port (u8 proto, ip46_address_t * ip)
 {
-  transport_endpoint_t *tep;
-  u32 tei;
   u16 min = 1024, max = 65535;	/* XXX configurable ? */
   int tries, limit;
+  u32 tei;
 
   limit = max - min;
 
@@ -347,96 +359,123 @@ transport_alloc_local_port (u8 proto, ip46_address_t * ip)
 				       port);
       if (tei == ENDPOINT_INVALID_INDEX)
 	{
-	  clib_spinlock_lock_if_init (&local_endpoints_lock);
-	  tep = transport_endpoint_new ();
-	  clib_memcpy (&tep->ip, ip, sizeof (*ip));
-	  tep->port = port;
-	  transport_endpoint_table_add (&local_endpoints_table, proto, tep,
-					tep - local_endpoints);
-	  clib_spinlock_unlock_if_init (&local_endpoints_lock);
-
-	  return tep->port;
+	  transport_endpoint_mark_used (proto, ip, port);
+	  return port;
 	}
     }
   return -1;
 }
 
-int
-transport_alloc_local_endpoint (u8 proto, transport_endpoint_t * rmt,
-				ip46_address_t * lcl_addr, u16 * lcl_port)
+static clib_error_t *
+transport_get_interface_ip (u32 sw_if_index, u8 is_ip4, ip46_address_t * addr)
 {
-  fib_prefix_t prefix;
-  fib_node_index_t fei;
-  u32 sw_if_index;
-  int port;
-
-  /*
-   * Find the local address and allocate port
-   */
-
-  /* Find a FIB path to the destination */
-  clib_memcpy (&prefix.fp_addr, &rmt->ip, sizeof (rmt->ip));
-  prefix.fp_proto = rmt->is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
-  prefix.fp_len = rmt->is_ip4 ? 32 : 128;
-
-  ASSERT (rmt->fib_index != ENDPOINT_INVALID_INDEX);
-  fei = fib_table_lookup (rmt->fib_index, &prefix);
-
-  /* Couldn't find route to destination. Bail out. */
-  if (fei == FIB_NODE_INDEX_INVALID)
+  if (is_ip4)
     {
-      clib_warning ("no route to destination");
-      return -1;
+      ip4_address_t *ip4;
+      ip4 = ip_interface_get_first_ip (sw_if_index, 1);
+      if (!ip4)
+	return clib_error_return (0, "no routable ip4 address on %U",
+				  format_vnet_sw_if_index_name,
+				  vnet_get_main (), sw_if_index);
+      addr->ip4.as_u32 = ip4->as_u32;
     }
+  else
+    {
+      ip6_address_t *ip6;
+      ip6 = ip_interface_get_first_ip (sw_if_index, 0);
+      if (ip6 == 0)
+	return clib_error_return (0, "no routable ip6 addresses on %U",
+				  format_vnet_sw_if_index_name,
+				  vnet_get_main (), sw_if_index);
+      clib_memcpy (&addr->ip6, ip6, sizeof (*ip6));
+    }
+  return 0;
+}
 
-  sw_if_index = rmt->sw_if_index;
-  if (sw_if_index == ENDPOINT_INVALID_INDEX)
-    sw_if_index = fib_entry_get_resolving_interface (fei);
+static clib_error_t *
+transport_find_local_ip_for_remote (u32 sw_if_index,
+				    transport_endpoint_t * rmt,
+				    ip46_address_t * lcl_addr)
+{
+  fib_node_index_t fei;
+  fib_prefix_t prefix;
 
   if (sw_if_index == ENDPOINT_INVALID_INDEX)
     {
-      clib_warning ("no resolving interface for %U", format_ip46_address,
-		    &rmt->ip, (rmt->is_ip4 == 0) + 1);
-      return -1;
+      /* Find a FIB path to the destination */
+      clib_memcpy (&prefix.fp_addr, &rmt->ip, sizeof (rmt->ip));
+      prefix.fp_proto = rmt->is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
+      prefix.fp_len = rmt->is_ip4 ? 32 : 128;
+
+      ASSERT (rmt->fib_index != ENDPOINT_INVALID_INDEX);
+      fei = fib_table_lookup (rmt->fib_index, &prefix);
+
+      /* Couldn't find route to destination. Bail out. */
+      if (fei == FIB_NODE_INDEX_INVALID)
+	return clib_error_return (0, "no route to %U", format_ip46_address,
+				  &rmt->ip, (rmt->is_ip4 == 0) + 1);
+
+      sw_if_index = fib_entry_get_resolving_interface (fei);
+      if (sw_if_index == ENDPOINT_INVALID_INDEX)
+	return clib_error_return (0, "no resolving interface for %U",
+				  format_ip46_address, &rmt->ip,
+				  (rmt->is_ip4 == 0) + 1);
     }
 
   clib_memset (lcl_addr, 0, sizeof (*lcl_addr));
+  return transport_get_interface_ip (sw_if_index, rmt->is_ip4, lcl_addr);
+}
 
-  if (rmt->is_ip4)
+int
+transport_alloc_local_endpoint (u8 proto, transport_endpoint_cfg_t * rmt_cfg,
+				ip46_address_t * lcl_addr, u16 * lcl_port)
+{
+  transport_endpoint_t *rmt = (transport_endpoint_t *) rmt_cfg;
+  clib_error_t *error;
+  int port;
+  u32 tei;
+
+  /*
+   * Find the local address
+   */
+  if (ip_is_zero (&rmt_cfg->peer.ip, rmt_cfg->peer.is_ip4))
     {
-      ip4_address_t *ip4;
-      ip4 = ip_interface_get_first_ip (sw_if_index, 1);
-      if (!ip4)
-	{
-	  clib_warning ("no routable ip4 address on %U",
-			format_vnet_sw_if_index_name, vnet_get_main (),
-			sw_if_index);
-	  return -1;
-	}
-      lcl_addr->ip4.as_u32 = ip4->as_u32;
+      error = transport_find_local_ip_for_remote (rmt_cfg->peer.sw_if_index,
+						  rmt, lcl_addr);
+      if (error)
+	return -1;
     }
   else
     {
-      ip6_address_t *ip6;
-      ip6 = ip_interface_get_first_ip (sw_if_index, 0);
-      if (ip6 == 0)
+      /* Assume session layer vetted this address */
+      clib_memcpy (lcl_addr, &rmt_cfg->peer.ip, sizeof (rmt_cfg->peer.ip));
+    }
+
+  /*
+   * Allocate source port
+   */
+  if (rmt_cfg->peer.port == 0)
+    {
+      port = transport_alloc_local_port (proto, lcl_addr);
+      if (port < 1)
 	{
-	  clib_warning ("no routable ip6 addresses on %U",
-			format_vnet_sw_if_index_name, vnet_get_main (),
-			sw_if_index);
+	  clib_warning ("Failed to allocate src port");
 	  return -1;
 	}
-      clib_memcpy (&lcl_addr->ip6, ip6, sizeof (*ip6));
+      *lcl_port = port;
     }
-
-  /* Allocate source port */
-  port = transport_alloc_local_port (proto, lcl_addr);
-  if (port < 1)
+  else
     {
-      clib_warning ("Failed to allocate src port");
-      return -1;
+      port = clib_net_to_host_u16 (rmt_cfg->peer.port);
+      tei = transport_endpoint_lookup (&local_endpoints_table, proto,
+				       lcl_addr, port);
+      if (tei != ENDPOINT_INVALID_INDEX)
+	return -1;
+
+      transport_endpoint_mark_used (proto, lcl_addr, port);
+      *lcl_port = port;
     }
-  *lcl_port = port;
+
   return 0;
 }
 
diff --git a/src/vnet/session/transport.h b/src/vnet/session/transport.h
index a4f26a45a6a..952f97d9ac3 100644
--- a/src/vnet/session/transport.h
+++ b/src/vnet/session/transport.h
@@ -122,20 +122,31 @@ u8 *format_transport_half_open_connection (u8 * s, va_list * args);
 
 uword unformat_transport_proto (unformat_input_t * input, va_list * args);
 
-#define foreach_transport_connection_fields				\
+#define foreach_transport_endpoint_fields				\
+  _(ip46_address_t, ip) /**< ip address in net order */			\
+  _(u16, port)		/**< port in net order */			\
+  _(u8, is_ip4)		/**< set if ip4 */				\
   _(u32, sw_if_index) 	/**< interface endpoint is associated with  */	\
-  _(ip46_address_t, ip) /**< ip address */				\
   _(u32, fib_index)	/**< fib table endpoint is associated with */	\
-  _(u8, is_ip4)		/**< set if ip4 */				\
-  _(u16, port)		/**< port in net order */			\
 
-typedef struct _transport_endpoint
+typedef struct transport_endpoint_
 {
 #define _(type, name) type name;
-  foreach_transport_connection_fields
+  foreach_transport_endpoint_fields
 #undef _
 } transport_endpoint_t;
 
+#define foreach_transport_endpoint_cfg_fields				\
+  foreach_transport_endpoint_fields					\
+  _(transport_endpoint_t, peer)						\
+
+typedef struct transport_endpoint_pair_
+{
+#define _(type, name) type name;
+  foreach_transport_endpoint_cfg_fields
+#undef _
+} transport_endpoint_cfg_t;
+
 typedef clib_bihash_24_8_t transport_endpoint_table_t;
 
 #define ENDPOINT_INVALID_INDEX ((u32)~0)
@@ -153,7 +164,7 @@ transport_endpoint_fib_proto (transport_endpoint_t * tep)
 }
 
 int transport_alloc_local_port (u8 proto, ip46_address_t * ip);
-int transport_alloc_local_endpoint (u8 proto, transport_endpoint_t * rmt,
+int transport_alloc_local_endpoint (u8 proto, transport_endpoint_cfg_t * rmt,
 				    ip46_address_t * lcl_addr,
 				    u16 * lcl_port);
 void transport_endpoint_cleanup (u8 proto, ip46_address_t * lcl_ip, u16 port);
diff --git a/src/vnet/session/transport_interface.h b/src/vnet/session/transport_interface.h
index a96c5e12d7a..ce3bb7fab7c 100644
--- a/src/vnet/session/transport_interface.h
+++ b/src/vnet/session/transport_interface.h
@@ -47,7 +47,7 @@ typedef struct _transport_proto_vft
    */
   u32 (*bind) (u32 session_index, transport_endpoint_t * lcl);
   u32 (*unbind) (u32);
-  int (*open) (transport_endpoint_t * rmt);
+  int (*open) (transport_endpoint_cfg_t * rmt);
   void (*close) (u32 conn_index, u32 thread_index);
   void (*cleanup) (u32 conn_index, u32 thread_index);
   clib_error_t *(*enable) (vlib_main_t * vm, u8 is_en);