session: support local sessions and deprecate redirects

Memfd backed shared memory segments can only be negotiated over sockets.
For such scenarios, the existing redirect mechanism that establishes
cut-through sessions does not work anymore as the two peer application
do not share such a socket.

This patch adds support for local sessions, as opposed to sessions
backed by a transport connection, in a way that is almost transparent to
the two applications by reusing the existing binary api messages.
Moreover, all segment allocations are now entirely done through the
segment manager valloc, so segment overlaps due to independent
allocations previously required for redirects are completely avoided.
The one notable characteristic of local sessions (cut-through from app
perspective) notification messages is that they carry pointers to two
event queues, one for each app peer, instead of one. For
transport-backed sessions one of the queues can be inferred but for
local session they cannot.

Change-Id: Ia443fb63e2d9d8e43490275062a708f039038175
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 63 insertions, 53 deletions

diff --git a/src/vnet/session/session_test.c b/src/vnet/session/session_test.c
index febe1b7998a..85e8732ddab 100644
--- a/src/vnet/session/session_test.c
+++ b/src/vnet/session/session_test.c
@@ -53,12 +53,20 @@ dummy_session_connected_callback (u32 app_index, u32 api_context,
   return -1;
 }
 
+static u32 dummy_segment_count;
+
 int
-dummy_add_segment_callback (u32 client_index, const u8 * seg_name,
-			    u32 seg_size)
+dummy_add_segment_callback (u32 client_index, const ssvm_private_t * fs)
 {
-  clib_warning ("called...");
-  return -1;
+  dummy_segment_count = 1;
+  return 0;
+}
+
+int
+dummy_del_segment_callback (u32 client_index, const ssvm_private_t * fs)
+{
+  dummy_segment_count = 0;
+  return 0;
 }
 
 int
@@ -73,11 +81,14 @@ dummy_session_disconnect_callback (stream_session_t * s)
   clib_warning ("called...");
 }
 
+static u32 dummy_accept;
+
 int
 dummy_session_accept_callback (stream_session_t * s)
 {
-  clib_warning ("called...");
-  return -1;
+  dummy_accept = 1;
+  s->session_state = SESSION_STATE_READY;
+  return 0;
 }
 
 int
@@ -94,7 +105,8 @@ static session_cb_vft_t dummy_session_cbs = {
   .session_accept_callback = dummy_session_accept_callback,
   .session_disconnect_callback = dummy_session_disconnect_callback,
   .builtin_server_rx_callback = dummy_server_rx_callback,
-  .redirect_connect_callback = dummy_redirect_connect_callback,
+  .add_segment_callback = dummy_add_segment_callback,
+  .del_segment_callback = dummy_del_segment_callback,
 };
 /* *INDENT-ON* */
 
@@ -146,7 +158,6 @@ session_test_basic (vlib_main_t * vm, unformat_input_t * input)
 
   memset (options, 0, sizeof (options));
   options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
-  options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_ACCEPT_REDIRECT;
   options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
   options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE;
   vnet_app_attach_args_t attach_args = {
@@ -205,7 +216,7 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
 {
   u64 options[APP_OPTIONS_N_OPTIONS], dummy_secret = 1234;
   u32 server_index, server_st_index, server_local_st_index;
-  u32 dummy_port = 1234, local_listener, client_index;
+  u32 dummy_port = 1234, client_index;
   u32 dummy_api_context = 4321, dummy_client_api_index = 1234;
   u32 dummy_server_api_index = ~0, sw_if_index = 0;
   session_endpoint_t server_sep = SESSION_ENDPOINT_NULL;
@@ -216,6 +227,7 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
   app_namespace_t *app_ns;
   application_t *server;
   stream_session_t *s;
+  u64 handle;
   int code;
 
   server_sep.is_ip4 = 1;
@@ -225,7 +237,6 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
   memset (options, 0, sizeof (options));
 
   options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
-  options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_ACCEPT_REDIRECT;
   vnet_app_attach_args_t attach_args = {
     .api_client_index = ~0,
     .options = options,
@@ -361,9 +372,8 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
   SESSION_TEST ((s->app_index == server_index), "app_index should be that of "
 		"the server");
   server_local_st_index = application_local_session_table (server);
-  local_listener =
-    session_lookup_local_endpoint (server_local_st_index, &server_sep);
-  SESSION_TEST ((local_listener != SESSION_INVALID_INDEX),
+  handle = session_lookup_local_endpoint (server_local_st_index, &server_sep);
+  SESSION_TEST ((handle != SESSION_INVALID_HANDLE),
 		"listener should exist in local table");
 
   /*
@@ -381,12 +391,15 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
   code = clib_error_get_code (error);
   SESSION_TEST ((code == VNET_API_ERROR_INVALID_VALUE),
 		"error code should be invalid value (zero ip)");
+  SESSION_TEST ((dummy_segment_count == 0),
+		"shouldn't have received request to map new segment");
   connect_args.sep.ip.ip4.as_u8[0] = 127;
   error = vnet_connect (&connect_args);
-  SESSION_TEST ((error != 0), "client connect should return error code");
+  SESSION_TEST ((error == 0), "client connect should not return error code");
   code = clib_error_get_code (error);
-  SESSION_TEST ((code == VNET_API_ERROR_SESSION_REDIRECT),
-		"error code should be redirect");
+  SESSION_TEST ((dummy_segment_count == 1),
+		"should've received request to map new segment");
+  SESSION_TEST ((dummy_accept == 1), "should've received accept request");
   detach_args.app_index = client_index;
   vnet_application_detach (&detach_args);
 
@@ -413,9 +426,9 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
 
   s = session_lookup_listener (server_st_index, &server_sep);
   SESSION_TEST ((s == 0), "listener should not exist in global table");
-  local_listener =
-    session_lookup_local_endpoint (server_local_st_index, &server_sep);
-  SESSION_TEST ((s == 0), "listener should not exist in local table");
+  handle = session_lookup_local_endpoint (server_local_st_index, &server_sep);
+  SESSION_TEST ((handle == SESSION_INVALID_HANDLE),
+		"listener should not exist in local table");
 
   detach_args.app_index = server_index;
   vnet_application_detach (&detach_args);
@@ -438,18 +451,16 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
   s = session_lookup_listener (server_st_index, &server_sep);
   SESSION_TEST ((s == 0), "listener should not exist in global table");
   server_local_st_index = application_local_session_table (server);
-  local_listener =
-    session_lookup_local_endpoint (server_local_st_index, &server_sep);
-  SESSION_TEST ((local_listener != SESSION_INVALID_INDEX),
+  handle = session_lookup_local_endpoint (server_local_st_index, &server_sep);
+  SESSION_TEST ((handle != SESSION_INVALID_HANDLE),
 		"listener should exist in local table");
 
   unbind_args.handle = bind_args.handle;
   error = vnet_unbind (&unbind_args);
   SESSION_TEST ((error == 0), "unbind should work");
 
-  local_listener =
-    session_lookup_local_endpoint (server_local_st_index, &server_sep);
-  SESSION_TEST ((local_listener == SESSION_INVALID_INDEX),
+  handle = session_lookup_local_endpoint (server_local_st_index, &server_sep);
+  SESSION_TEST ((handle == SESSION_INVALID_HANDLE),
 		"listener should not exist in local table");
 
   /*
@@ -510,9 +521,8 @@ session_test_namespace (vlib_main_t * vm, unformat_input_t * input)
   SESSION_TEST ((s->app_index == server_index), "app_index should be that of "
 		"the server");
   server_local_st_index = application_local_session_table (server);
-  local_listener =
-    session_lookup_local_endpoint (server_local_st_index, &server_sep);
-  SESSION_TEST ((local_listener != SESSION_INVALID_INDEX),
+  handle = session_lookup_local_endpoint (server_local_st_index, &server_sep);
+  SESSION_TEST ((handle != SESSION_INVALID_HANDLE),
 		"zero listener should exist in local table");
   detach_args.app_index = server_index;
   vnet_application_detach (&detach_args);
@@ -800,7 +810,7 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
   session_endpoint_t server_sep = SESSION_ENDPOINT_NULL;
   u64 options[APP_OPTIONS_N_OPTIONS];
   u16 lcl_port = 1234, rmt_port = 4321;
-  u32 server_index, server_index2, app_index;
+  u32 server_index, server_index2;
   u32 dummy_server_api_index = ~0;
   transport_connection_t *tc;
   u32 dummy_port = 1111;
@@ -811,6 +821,7 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
   u32 local_ns_index = default_ns->local_table_index;
   int verbose = 0, rv;
   app_namespace_t *app_ns;
+  u64 handle;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
@@ -844,7 +855,6 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
    * Attach server with global and local default scope
    */
   options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
-  options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_ACCEPT_REDIRECT;
   options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
   options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE;
   attach_args.namespace_id = 0;
@@ -918,8 +928,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
     .port = rmt_port,
     .transport_proto = TRANSPORT_PROTO_TCP,
   };
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index != server_index), "local session endpoint lookup "
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle != server_index), "local session endpoint lookup "
 		"should not work (global scope)");
 
   tc = session_lookup_connection_wt4 (0, &lcl_pref.fp_addr.ip4,
@@ -943,8 +953,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
 				      &is_filtered);
   SESSION_TEST ((tc->c_index == listener->connection_index),
 		"optimized lookup for lcl port + 1 should work");
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == server_index), "local session endpoint lookup "
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == server_index), "local session endpoint lookup "
 		"should work (lcl ip was zeroed)");
 
   /*
@@ -976,8 +986,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
 		"should fail (deny rule)");
   SESSION_TEST ((is_filtered == 1), "lookup should be filtered (deny)");
 
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_DROP_INDEX), "lookup for 1.2.3.4/32 1234 "
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_DROP_HANDLE), "lookup for 1.2.3.4/32 1234 "
 		"5.6.7.8/16 4321 in local table should return deny");
 
   tc = session_lookup_connection_wt4 (0, &lcl_pref.fp_addr.ip4,
@@ -1011,9 +1021,9 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
 		"should fail (allow without app)");
   SESSION_TEST ((is_filtered == 0), "lookup should NOT be filtered");
 
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_INVALID_INDEX), "lookup for 1.2.3.4/32 1234"
-		" 5.6.7.8/32 4321 in local table should return invalid");
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_INVALID_HANDLE), "lookup for 1.2.3.4/32 "
+		"1234 5.6.7.8/32 4321 in local table should return invalid");
 
   if (verbose)
     {
@@ -1023,8 +1033,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
     }
 
   sep.ip.ip4.as_u32 += 1 << 24;
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_DROP_INDEX), "lookup for 1.2.3.4/32 1234"
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_DROP_HANDLE), "lookup for 1.2.3.4/32 1234"
 		" 5.6.7.9/32 4321 in local table should return deny");
 
   vnet_connect_args_t connect_args = {
@@ -1075,8 +1085,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
 					     TRANSPORT_PROTO_TCP);
     }
 
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_DROP_INDEX),
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_DROP_HANDLE),
 		"local session endpoint lookup should return deny");
 
   /*
@@ -1091,8 +1101,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
   error = vnet_session_rule_add_del (&args);
   SESSION_TEST ((error == 0), "Del 1.2.3.4/32 1234 5.6.7.8/32 4321 deny");
 
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_INVALID_INDEX),
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_INVALID_HANDLE),
 		"local session endpoint lookup should return invalid");
 
   /*
@@ -1108,8 +1118,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
   args.table_args.rmt_port = 4321;
   error = vnet_session_rule_add_del (&args);
   SESSION_TEST ((error == 0), "Del 0/0 * 5.6.7.8/16 4321");
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index != server_index), "local session endpoint lookup "
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle != server_index), "local session endpoint lookup "
 		"should not work (removed)");
 
   args.table_args.is_add = 0;
@@ -1296,14 +1306,14 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
   /*
    * Lookup default namespace
    */
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_INVALID_INDEX),
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_INVALID_HANDLE),
 		"lookup for 1.2.3.4/32 1234 5.6.7.8/32 4321 in local table "
 		"should return allow (invalid)");
 
   sep.port += 1;
-  app_index = session_lookup_local_endpoint (local_ns_index, &sep);
-  SESSION_TEST ((app_index == APP_DROP_INDEX), "lookup for 1.2.3.4/32 1234 "
+  handle = session_lookup_local_endpoint (local_ns_index, &sep);
+  SESSION_TEST ((handle == SESSION_DROP_HANDLE), "lookup for 1.2.3.4/32 1234 "
 		"5.6.7.8/16 432*2* in local table should return deny");
 
   connect_args.app_index = server_index;
@@ -1317,8 +1327,8 @@ session_test_rules (vlib_main_t * vm, unformat_input_t * input)
   /*
    * Lookup test namespace
    */
-  app_index = session_lookup_local_endpoint (app_ns->local_table_index, &sep);
-  SESSION_TEST ((app_index == APP_DROP_INDEX), "lookup for 1.2.3.4/32 1234 "
+  handle = session_lookup_local_endpoint (app_ns->local_table_index, &sep);
+  SESSION_TEST ((handle == SESSION_DROP_HANDLE), "lookup for 1.2.3.4/32 1234 "
 		"5.6.7.8/16 4321 in local table should return deny");
 
   connect_args.app_index = server_index;