Session layer refactoring

Major refactoring of the session layer api
- Add attatch api for application binding to the the session layer
- Simplify listen/connect calls
- Update application CLI
- Add transport endpoint to accept callback
- Associate segment manager to application and allow for multiple
  binds/connects per app

Additional:
- svm fifo cleanup
- add fifo free, format fns
- add fifo offset enqueue unit test

Change-Id: Id93a65047de61afc2bf3d58c9b544339c02065af
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Barach <dave@barachs.net>

2 files changed, 416 insertions, 225 deletions

diff --git a/src/uri/uri_tcp_test.c b/src/uri/uri_tcp_test.c
index e2834817..c057e06e 100644
--- a/src/uri/uri_tcp_test.c
+++ b/src/uri/uri_tcp_test.c
@@ -15,8 +15,6 @@
 
 #include <stdio.h>
 #include <signal.h>
-#include <vlib/vlib.h>
-#include <vnet/vnet.h>
 #include <svm/svm_fifo_segment.h>
 #include <vlibmemory/api.h>
 #include <vpp/api/vpe_msg_enum.h>
@@ -47,8 +45,7 @@ typedef struct
   svm_fifo_t *server_rx_fifo;
   svm_fifo_t *server_tx_fifo;
 
-  u32 vpp_session_index;
-  u32 vpp_session_thread;
+  u32 vpp_session_handle;
 } session_t;
 
 typedef enum
@@ -116,7 +113,7 @@ typedef struct
   pthread_t client_rx_thread_handle;
   u32 client_bytes_received;
   u8 test_return_packets;
-  u32 bytes_to_send;
+  u64 bytes_to_send;
 
   /* convenience */
   svm_fifo_segment_main_t *segment_main;
@@ -152,6 +149,88 @@ wait_for_state_change (uri_tcp_test_main_t * utm, connection_state_t state)
   return -1;
 }
 
+void
+application_attach (uri_tcp_test_main_t * utm)
+{
+  vl_api_application_attach_t *bmp;
+  u32 fifo_size = 3 << 20;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_APPLICATION_ATTACH);
+  bmp->client_index = utm->my_client_index;
+  bmp->context = ntohl (0xfeedface);
+  bmp->options[SESSION_OPTIONS_FLAGS] =
+    SESSION_OPTIONS_FLAGS_USE_FIFO | SESSION_OPTIONS_FLAGS_ADD_SEGMENT;
+  bmp->options[SESSION_OPTIONS_RX_FIFO_SIZE] = fifo_size;
+  bmp->options[SESSION_OPTIONS_TX_FIFO_SIZE] = fifo_size;
+  bmp->options[SESSION_OPTIONS_ADD_SEGMENT_SIZE] = 128 << 20;
+  bmp->options[SESSION_OPTIONS_SEGMENT_SIZE] = 256 << 20;
+  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & bmp);
+}
+
+void
+application_detach (uri_tcp_test_main_t * utm)
+{
+  vl_api_application_detach_t *bmp;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_APPLICATION_DETACH);
+  bmp->client_index = utm->my_client_index;
+  bmp->context = ntohl (0xfeedface);
+  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & bmp);
+}
+
+static void
+vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
+					   mp)
+{
+  uri_tcp_test_main_t *utm = &uri_tcp_test_main;
+  svm_fifo_segment_create_args_t _a, *a = &_a;
+  int rv;
+
+  if (mp->retval)
+    {
+      uword *errp = hash_get (utm->error_string_by_error_number, mp->retval);
+      clib_warning ("attach failed: %s", *errp);
+      utm->state = STATE_FAILED;
+      return;
+    }
+
+  if (mp->segment_name_length == 0)
+    {
+      clib_warning ("segment_name_length zero");
+      return;
+    }
+
+  a->segment_name = (char *) mp->segment_name;
+  a->segment_size = mp->segment_size;
+
+  ASSERT (mp->app_event_queue_address);
+
+  /* Attach to the segment vpp created */
+  rv = svm_fifo_segment_attach (a);
+  if (rv)
+    {
+      clib_warning ("svm_fifo_segment_attach ('%s') failed",
+		    mp->segment_name);
+      return;
+    }
+
+  utm->our_event_queue =
+    (unix_shared_memory_queue_t *) mp->app_event_queue_address;
+
+}
+
+static void
+vl_api_application_detach_reply_t_handler (vl_api_application_detach_reply_t *
+					   mp)
+{
+  if (mp->retval)
+    clib_warning ("detach returned with err: %d", mp->retval);
+}
+
 static void
 init_error_string_table (uri_tcp_test_main_t * utm)
 {
@@ -239,21 +318,18 @@ vl_api_disconnect_session_t_handler (vl_api_disconnect_session_t * mp)
   vl_api_disconnect_session_reply_t *rmp;
   uword *p;
   int rv = 0;
-  u64 key;
-
-  key = (((u64) mp->session_thread_index) << 32) | (u64) mp->session_index;
 
-  p = hash_get (utm->session_index_by_vpp_handles, key);
+  p = hash_get (utm->session_index_by_vpp_handles, mp->handle);
 
   if (p)
     {
       session = pool_elt_at_index (utm->sessions, p[0]);
-      hash_unset (utm->session_index_by_vpp_handles, key);
+      hash_unset (utm->session_index_by_vpp_handles, mp->handle);
       pool_put (utm->sessions, session);
     }
   else
     {
-      clib_warning ("couldn't find session key %llx", key);
+      clib_warning ("couldn't find session key %llx", mp->handle);
       rv = -11;
     }
 
@@ -264,8 +340,7 @@ vl_api_disconnect_session_t_handler (vl_api_disconnect_session_t * mp)
 
   rmp->_vl_msg_id = ntohs (VL_API_DISCONNECT_SESSION_REPLY);
   rmp->retval = rv;
-  rmp->session_index = mp->session_index;
-  rmp->session_thread_index = mp->session_thread_index;
+  rmp->handle = mp->handle;
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & rmp);
 }
 
@@ -277,22 +352,19 @@ vl_api_reset_session_t_handler (vl_api_reset_session_t * mp)
   vl_api_reset_session_reply_t *rmp;
   uword *p;
   int rv = 0;
-  u64 key;
 
-  key = (((u64) mp->session_thread_index) << 32) | (u64) mp->session_index;
-
-  p = hash_get (utm->session_index_by_vpp_handles, key);
+  p = hash_get (utm->session_index_by_vpp_handles, mp->handle);
 
   if (p)
     {
       session = pool_elt_at_index (utm->sessions, p[0]);
-      hash_unset (utm->session_index_by_vpp_handles, key);
+      hash_unset (utm->session_index_by_vpp_handles, mp->handle);
       pool_put (utm->sessions, session);
       utm->time_to_stop = 1;
     }
   else
     {
-      clib_warning ("couldn't find session key %llx", key);
+      clib_warning ("couldn't find session key %llx", mp->handle);
       rv = -11;
     }
 
@@ -300,8 +372,7 @@ vl_api_reset_session_t_handler (vl_api_reset_session_t * mp)
   memset (rmp, 0, sizeof (*rmp));
   rmp->_vl_msg_id = ntohs (VL_API_RESET_SESSION_REPLY);
   rmp->retval = rv;
-  rmp->session_index = mp->session_index;
-  rmp->session_thread_index = mp->session_thread_index;
+  rmp->handle = mp->handle;
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & rmp);
 }
 
@@ -343,7 +414,7 @@ client_handle_fifo_event_rx (uri_tcp_test_main_t * utm,
 	{
 	  if (n_read == -2)
 	    {
-	      clib_warning ("weird!");
+//            clib_warning ("weird!");
 	      break;
 	    }
 	}
@@ -409,52 +480,19 @@ static void
 vl_api_connect_uri_reply_t_handler (vl_api_connect_uri_reply_t * mp)
 {
   uri_tcp_test_main_t *utm = &uri_tcp_test_main;
-  svm_fifo_segment_create_args_t _a, *a = &_a;
   session_t *session;
   u32 session_index;
   svm_fifo_t *rx_fifo, *tx_fifo;
   int rv;
-  u64 key;
 
   if (mp->retval)
     {
-      clib_warning ("connection failed with code: %d", mp->retval);
-      utm->state = STATE_FAILED;
-      return;
-    }
-
-  /*
-   * Attatch to segment
-   */
-
-  if (mp->segment_name_length == 0)
-    {
-      clib_warning ("segment_name_length zero");
+      uword *errp = hash_get (utm->error_string_by_error_number, -mp->retval);
+      clib_warning ("connection failed with code: %s", *errp);
       utm->state = STATE_FAILED;
       return;
     }
 
-  a->segment_name = (char *) mp->segment_name;
-  a->segment_size = mp->segment_size;
-
-  ASSERT (mp->client_event_queue_address);
-
-  /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (a);
-  if (rv)
-    {
-      clib_warning ("svm_fifo_segment_attach ('%s') failed",
-		    mp->segment_name);
-      return;
-    }
-
-  /*
-   * Save the queues
-   */
-
-  utm->our_event_queue = (unix_shared_memory_queue_t *)
-    mp->client_event_queue_address;
-
   utm->vpp_event_queue = (unix_shared_memory_queue_t *)
     mp->vpp_event_queue_address;
 
@@ -472,16 +510,14 @@ vl_api_connect_uri_reply_t_handler (vl_api_connect_uri_reply_t * mp)
 
   session->server_rx_fifo = rx_fifo;
   session->server_tx_fifo = tx_fifo;
-  session->vpp_session_index = mp->session_index;
-  session->vpp_session_thread = mp->session_thread_index;
+  session->vpp_session_handle = mp->handle;
 
   /* Save handle */
   utm->connected_session_index = session_index;
   utm->state = STATE_READY;
 
   /* Add it to lookup table */
-  key = (((u64) mp->session_thread_index) << 32) | (u64) mp->session_index;
-  hash_set (utm->session_index_by_vpp_handles, key, session_index);
+  hash_set (utm->session_index_by_vpp_handles, mp->handle, session_index);
 
   /* Start RX thread */
   rv = pthread_create (&utm->client_rx_thread_handle,
@@ -606,8 +642,7 @@ client_disconnect (uri_tcp_test_main_t * utm)
   memset (dmp, 0, sizeof (*dmp));
   dmp->_vl_msg_id = ntohs (VL_API_DISCONNECT_SESSION);
   dmp->client_index = utm->my_client_index;
-  dmp->session_index = connected_session->vpp_session_index;
-  dmp->session_thread_index = connected_session->vpp_session_thread;
+  dmp->handle = connected_session->vpp_session_handle;
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & dmp);
 }
 
@@ -616,6 +651,7 @@ client_test (uri_tcp_test_main_t * utm)
 {
   int i;
 
+  application_attach (utm);
   client_connect (utm);
 
   if (wait_for_state_change (utm, STATE_READY))
@@ -636,47 +672,26 @@ client_test (uri_tcp_test_main_t * utm)
 
   if (wait_for_state_change (utm, STATE_START))
     {
+      clib_warning ("Disconnect failed");
       return;
     }
+  application_detach (utm);
 }
 
 static void
 vl_api_bind_uri_reply_t_handler (vl_api_bind_uri_reply_t * mp)
 {
   uri_tcp_test_main_t *utm = &uri_tcp_test_main;
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  int rv;
 
   if (mp->retval)
     {
-      clib_warning ("bind failed: %d", mp->retval);
+      uword *errp = hash_get (utm->error_string_by_error_number,
+			      -clib_net_to_host_u32 (mp->retval));
+      clib_warning ("bind failed: %s", (char *) *errp);
       utm->state = STATE_FAILED;
       return;
     }
 
-  if (mp->segment_name_length == 0)
-    {
-      clib_warning ("segment_name_length zero");
-      return;
-    }
-
-  a->segment_name = (char *) mp->segment_name;
-  a->segment_size = mp->segment_size;
-
-  ASSERT (mp->server_event_queue_address);
-
-  /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (a);
-  if (rv)
-    {
-      clib_warning ("svm_fifo_segment_attach ('%s') failed",
-		    mp->segment_name);
-      return;
-    }
-
-  utm->our_event_queue =
-    (unix_shared_memory_queue_t *) mp->server_event_queue_address;
-
   utm->state = STATE_READY;
 }
 
@@ -691,6 +706,89 @@ vl_api_unbind_uri_reply_t_handler (vl_api_unbind_uri_reply_t * mp)
   utm->state = STATE_START;
 }
 
+u8 *
+format_ip4_address (u8 * s, va_list * args)
+{
+  u8 *a = va_arg (*args, u8 *);
+  return format (s, "%d.%d.%d.%d", a[0], a[1], a[2], a[3]);
+}
+
+u8 *
+format_ip6_address (u8 * s, va_list * args)
+{
+  ip6_address_t *a = va_arg (*args, ip6_address_t *);
+  u32 i, i_max_n_zero, max_n_zeros, i_first_zero, n_zeros, last_double_colon;
+
+  i_max_n_zero = ARRAY_LEN (a->as_u16);
+  max_n_zeros = 0;
+  i_first_zero = i_max_n_zero;
+  n_zeros = 0;
+  for (i = 0; i < ARRAY_LEN (a->as_u16); i++)
+    {
+      u32 is_zero = a->as_u16[i] == 0;
+      if (is_zero && i_first_zero >= ARRAY_LEN (a->as_u16))
+	{
+	  i_first_zero = i;
+	  n_zeros = 0;
+	}
+      n_zeros += is_zero;
+      if ((!is_zero && n_zeros > max_n_zeros)
+	  || (i + 1 >= ARRAY_LEN (a->as_u16) && n_zeros > max_n_zeros))
+	{
+	  i_max_n_zero = i_first_zero;
+	  max_n_zeros = n_zeros;
+	  i_first_zero = ARRAY_LEN (a->as_u16);
+	  n_zeros = 0;
+	}
+    }
+
+  last_double_colon = 0;
+  for (i = 0; i < ARRAY_LEN (a->as_u16); i++)
+    {
+      if (i == i_max_n_zero && max_n_zeros > 1)
+	{
+	  s = format (s, "::");
+	  i += max_n_zeros - 1;
+	  last_double_colon = 1;
+	}
+      else
+	{
+	  s = format (s, "%s%x",
+		      (last_double_colon || i == 0) ? "" : ":",
+		      clib_net_to_host_u16 (a->as_u16[i]));
+	  last_double_colon = 0;
+	}
+    }
+
+  return s;
+}
+
+/* Format an IP46 address. */
+u8 *
+format_ip46_address (u8 * s, va_list * args)
+{
+  ip46_address_t *ip46 = va_arg (*args, ip46_address_t *);
+  ip46_type_t type = va_arg (*args, ip46_type_t);
+  int is_ip4 = 1;
+
+  switch (type)
+    {
+    case IP46_TYPE_ANY:
+      is_ip4 = ip46_address_is_ip4 (ip46);
+      break;
+    case IP46_TYPE_IP4:
+      is_ip4 = 1;
+      break;
+    case IP46_TYPE_IP6:
+      is_ip4 = 0;
+      break;
+    }
+
+  return is_ip4 ?
+    format (s, "%U", format_ip4_address, &ip46->ip4) :
+    format (s, "%U", format_ip6_address, &ip46->ip6);
+}
+
 static void
 vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
 {
@@ -699,12 +797,15 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   svm_fifo_t *rx_fifo, *tx_fifo;
   session_t *session;
   static f64 start_time;
-  u64 key;
   u32 session_index;
+  u8 *ip_str;
 
   if (start_time == 0.0)
     start_time = clib_time_now (&utm->clib_time);
 
+  ip_str = format (0, "%U", format_ip46_address, &mp->ip, mp->is_ip4);
+  clib_warning ("Accepted session from: %s:%d", ip_str,
+		clib_net_to_host_u16 (mp->port));
   utm->vpp_event_queue = (unix_shared_memory_queue_t *)
     mp->vpp_event_queue_address;
 
@@ -721,8 +822,7 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   session->server_tx_fifo = tx_fifo;
 
   /* Add it to lookup table */
-  key = (((u64) mp->session_thread_index) << 32) | (u64) mp->session_index;
-  hash_set (utm->session_index_by_vpp_handles, key, session_index);
+  hash_set (utm->session_index_by_vpp_handles, mp->handle, session_index);
 
   utm->state = STATE_READY;
 
@@ -741,9 +841,7 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   rmp = vl_msg_api_alloc (sizeof (*rmp));
   memset (rmp, 0, sizeof (*rmp));
   rmp->_vl_msg_id = ntohs (VL_API_ACCEPT_SESSION_REPLY);
-  rmp->session_type = mp->session_type;
-  rmp->session_index = mp->session_index;
-  rmp->session_thread_index = mp->session_thread_index;
+  rmp->handle = mp->handle;
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & rmp);
 }
 
@@ -837,22 +935,15 @@ server_handle_event_queue (uri_tcp_test_main_t * utm)
 }
 
 void
-server_bind (uri_tcp_test_main_t * utm)
+server_listen (uri_tcp_test_main_t * utm)
 {
   vl_api_bind_uri_t *bmp;
-  u32 fifo_size = 3 << 20;
   bmp = vl_msg_api_alloc (sizeof (*bmp));
   memset (bmp, 0, sizeof (*bmp));
 
   bmp->_vl_msg_id = ntohs (VL_API_BIND_URI);
   bmp->client_index = utm->my_client_index;
   bmp->context = ntohl (0xfeedface);
-  bmp->initial_segment_size = 256 << 20;	/* size of initial segment */
-  bmp->options[SESSION_OPTIONS_FLAGS] =
-    SESSION_OPTIONS_FLAGS_USE_FIFO | SESSION_OPTIONS_FLAGS_ADD_SEGMENT;
-  bmp->options[SESSION_OPTIONS_RX_FIFO_SIZE] = fifo_size;
-  bmp->options[SESSION_OPTIONS_TX_FIFO_SIZE] = fifo_size;
-  bmp->options[SESSION_OPTIONS_ADD_SEGMENT_SIZE] = 128 << 20;
   memcpy (bmp->uri, utm->uri, vec_len (utm->uri));
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & bmp);
 }
@@ -874,8 +965,10 @@ server_unbind (uri_tcp_test_main_t * utm)
 void
 server_test (uri_tcp_test_main_t * utm)
 {
+  application_attach (utm);
+
   /* Bind to uri */
-  server_bind (utm);
+  server_listen (utm);
 
   if (wait_for_state_change (utm, STATE_READY))
     {
@@ -895,6 +988,8 @@ server_test (uri_tcp_test_main_t * utm)
       return;
     }
 
+  application_detach (utm);
+
   fformat (stdout, "Test complete...\n");
 }
 
@@ -916,7 +1011,9 @@ _(CONNECT_URI_REPLY, connect_uri_reply)                 \
 _(DISCONNECT_SESSION, disconnect_session)               \
 _(DISCONNECT_SESSION_REPLY, disconnect_session_reply)   \
 _(RESET_SESSION, reset_session)                         \
-_(MAP_ANOTHER_SEGMENT, map_another_segment)
+_(APPLICATION_ATTACH_REPLY, application_attach_reply)   \
+_(APPLICATION_DETACH_REPLY, application_detach_reply)	\
+_(MAP_ANOTHER_SEGMENT, map_another_segment)		\
 
 void
 uri_api_hookup (uri_tcp_test_main_t * utm)
@@ -941,7 +1038,7 @@ main (int argc, char **argv)
   u8 *heap, *uri = 0;
   u8 *bind_uri = (u8 *) "tcp://0.0.0.0/1234";
   u8 *connect_uri = (u8 *) "tcp://6.0.1.2/1234";
-  u32 bytes_to_send = 64 << 10, mbytes;
+  u64 bytes_to_send = 64 << 10, mbytes;
   u32 tmp;
   mheap_t *h;
   session_t *session;
@@ -988,10 +1085,14 @@ main (int argc, char **argv)
 	drop_packets = 1;
       else if (unformat (a, "test"))
 	test_return_packets = 1;
-      else if (unformat (a, "mbytes %d", &mbytes))
+      else if (unformat (a, "mbytes %lld", &mbytes))
 	{
 	  bytes_to_send = mbytes << 20;
 	}
+      else if (unformat (a, "gbytes %lld", &mbytes))
+	{
+	  bytes_to_send = mbytes << 30;
+	}
       else
 	{
 	  fformat (stderr, "%s: usage [master|slave]\n");
diff --git a/src/uri/uri_udp_test.c b/src/uri/uri_udp_test.c
index e6c239c1..598052bc 100644
--- a/src/uri/uri_udp_test.c
+++ b/src/uri/uri_udp_test.c
@@ -55,6 +55,7 @@ typedef enum
 {
   STATE_START,
   STATE_READY,
+  STATE_FAILED,
   STATE_DISCONNECTING,
 } connection_state_t;
 
@@ -162,6 +163,86 @@ setup_signal_handlers (void)
   return 0;
 }
 
+void
+application_attach (uri_udp_test_main_t * utm)
+{
+  vl_api_application_attach_t *bmp;
+  u32 fifo_size = 3 << 20;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_APPLICATION_ATTACH);
+  bmp->client_index = utm->my_client_index;
+  bmp->context = ntohl (0xfeedface);
+  bmp->options[SESSION_OPTIONS_FLAGS] =
+    SESSION_OPTIONS_FLAGS_USE_FIFO | SESSION_OPTIONS_FLAGS_ADD_SEGMENT;
+  bmp->options[SESSION_OPTIONS_RX_FIFO_SIZE] = fifo_size;
+  bmp->options[SESSION_OPTIONS_TX_FIFO_SIZE] = fifo_size;
+  bmp->options[SESSION_OPTIONS_ADD_SEGMENT_SIZE] = 128 << 20;
+  bmp->options[SESSION_OPTIONS_SEGMENT_SIZE] = 256 << 20;
+  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & bmp);
+}
+
+void
+application_detach (uri_udp_test_main_t * utm)
+{
+  vl_api_application_detach_t *bmp;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_APPLICATION_DETACH);
+  bmp->client_index = utm->my_client_index;
+  bmp->context = ntohl (0xfeedface);
+  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & bmp);
+}
+
+static void
+vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
+					   mp)
+{
+  uri_udp_test_main_t *utm = &uri_udp_test_main;
+  svm_fifo_segment_create_args_t _a, *a = &_a;
+  int rv;
+
+  if (mp->retval)
+    {
+      clib_warning ("attach failed: %d", mp->retval);
+      utm->state = STATE_FAILED;
+      return;
+    }
+
+  if (mp->segment_name_length == 0)
+    {
+      clib_warning ("segment_name_length zero");
+      return;
+    }
+
+  a->segment_name = (char *) mp->segment_name;
+  a->segment_size = mp->segment_size;
+
+  ASSERT (mp->app_event_queue_address);
+
+  /* Attach to the segment vpp created */
+  rv = svm_fifo_segment_attach (a);
+  if (rv)
+    {
+      clib_warning ("svm_fifo_segment_attach ('%s') failed",
+		    mp->segment_name);
+      return;
+    }
+
+  utm->our_event_queue =
+    (unix_shared_memory_queue_t *) mp->app_event_queue_address;
+}
+
+static void
+vl_api_application_detach_reply_t_handler (vl_api_application_detach_reply_t *
+					   mp)
+{
+  if (mp->retval)
+    clib_warning ("detach returned with err: %d", mp->retval);
+}
+
 u8 *
 format_api_error (u8 * s, va_list * args)
 {
@@ -255,9 +336,22 @@ cut_through_thread_fn (void *arg)
 }
 
 static void
-uri_udp_slave_test (uri_udp_test_main_t * utm)
+udp_client_connect (uri_udp_test_main_t * utm)
 {
   vl_api_connect_uri_t *cmp;
+  cmp = vl_msg_api_alloc (sizeof (*cmp));
+  memset (cmp, 0, sizeof (*cmp));
+
+  cmp->_vl_msg_id = ntohs (VL_API_CONNECT_URI);
+  cmp->client_index = utm->my_client_index;
+  cmp->context = ntohl (0xfeedface);
+  memcpy (cmp->uri, utm->connect_uri, vec_len (utm->connect_uri));
+  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & cmp);
+}
+
+static void
+client_send (uri_udp_test_main_t * utm, session_t * session)
+{
   int i;
   u8 *test_data = 0;
   u64 bytes_received = 0, bytes_sent = 0;
@@ -265,30 +359,16 @@ uri_udp_slave_test (uri_udp_test_main_t * utm)
   int rv;
   int mypid = getpid ();
   f64 before, after, delta, bytes_per_second;
-  session_t *session;
   svm_fifo_t *rx_fifo, *tx_fifo;
   int buffer_offset, bytes_to_send = 0;
 
+  /*
+   * Prepare test data
+   */
   vec_validate (test_data, 64 * 1024 - 1);
   for (i = 0; i < vec_len (test_data); i++)
     test_data[i] = i & 0xff;
 
-  cmp = vl_msg_api_alloc (sizeof (*cmp));
-  memset (cmp, 0, sizeof (*cmp));
-
-  cmp->_vl_msg_id = ntohs (VL_API_CONNECT_URI);
-  cmp->client_index = utm->my_client_index;
-  cmp->context = ntohl (0xfeedface);
-  memcpy (cmp->uri, utm->connect_uri, vec_len (utm->connect_uri));
-  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & cmp);
-
-  if (wait_for_state_change (utm, STATE_READY))
-    {
-      clib_warning ("timeout waiting for STATE_READY");
-      return;
-    }
-
-  session = pool_elt_at_index (utm->sessions, utm->cut_through_session_index);
   rx_fifo = session->server_rx_fifo;
   tx_fifo = session->server_tx_fifo;
 
@@ -375,35 +455,38 @@ uri_udp_slave_test (uri_udp_test_main_t * utm)
 }
 
 static void
-vl_api_bind_uri_reply_t_handler (vl_api_bind_uri_reply_t * mp)
+uri_udp_client_test (uri_udp_test_main_t * utm)
 {
-  uri_udp_test_main_t *utm = &uri_udp_test_main;
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  int rv;
+  session_t *session;
 
-  if (mp->segment_name_length == 0)
+  application_attach (utm);
+  udp_client_connect (utm);
+
+  if (wait_for_state_change (utm, STATE_READY))
     {
-      clib_warning ("segment_name_length zero");
+      clib_warning ("timeout waiting for STATE_READY");
       return;
     }
 
-  a->segment_name = (char *) mp->segment_name;
-  a->segment_size = mp->segment_size;
+  /* Only works with cut through sessions */
+  session = pool_elt_at_index (utm->sessions, utm->cut_through_session_index);
 
-  ASSERT (mp->server_event_queue_address);
+  client_send (utm, session);
+  application_detach (utm);
+}
 
-  /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (a);
-  if (rv)
+static void
+vl_api_bind_uri_reply_t_handler (vl_api_bind_uri_reply_t * mp)
+{
+  uri_udp_test_main_t *utm = &uri_udp_test_main;
+
+  if (mp->retval)
     {
-      clib_warning ("svm_fifo_segment_attach ('%s') failed",
-		    mp->segment_name);
+      clib_warning ("bind failed: %d", mp->retval);
+      utm->state = STATE_FAILED;
       return;
     }
 
-  utm->our_event_queue = (unix_shared_memory_queue_t *)
-    mp->server_event_queue_address;
-
   utm->state = STATE_READY;
 }
 
@@ -427,6 +510,9 @@ vl_api_map_another_segment_t_handler (vl_api_map_another_segment_t * mp)
 		mp->segment_size);
 }
 
+/**
+ * Acting as server for redirected connect requests
+ */
 static void
 vl_api_connect_uri_t_handler (vl_api_connect_uri_t * mp)
 {
@@ -456,7 +542,6 @@ vl_api_connect_uri_t_handler (vl_api_connect_uri_t * mp)
   vec_add2 (utm->seg, seg, 1);
 
   segment_index = vec_len (sm->segments) - 1;
-
   memcpy (seg, sm->segments + segment_index, sizeof (utm->seg[0]));
 
   pool_get (utm->sessions, session);
@@ -521,7 +606,6 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   svm_fifo_t *rx_fifo, *tx_fifo;
   session_t *session;
   static f64 start_time;
-  u64 key;
 
   if (start_time == 0.0)
     start_time = clib_time_now (&utm->clib_time);
@@ -539,9 +623,8 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   session->server_rx_fifo = rx_fifo;
   session->server_tx_fifo = tx_fifo;
 
-  key = (((u64) mp->session_thread_index) << 32) | (u64) mp->session_index;
-
-  hash_set (utm->session_index_by_vpp_handles, key, session - utm->sessions);
+  hash_set (utm->session_index_by_vpp_handles, mp->handle,
+	    session - utm->sessions);
 
   utm->state = STATE_READY;
 
@@ -556,9 +639,7 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   rmp = vl_msg_api_alloc (sizeof (*rmp));
   memset (rmp, 0, sizeof (*rmp));
   rmp->_vl_msg_id = ntohs (VL_API_ACCEPT_SESSION_REPLY);
-  rmp->session_type = mp->session_type;
-  rmp->session_index = mp->session_index;
-  rmp->session_thread_index = mp->session_thread_index;
+  rmp->handle = mp->handle;
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & rmp);
 }
 
@@ -570,21 +651,18 @@ vl_api_disconnect_session_t_handler (vl_api_disconnect_session_t * mp)
   vl_api_disconnect_session_reply_t *rmp;
   uword *p;
   int rv = 0;
-  u64 key;
-
-  key = (((u64) mp->session_thread_index) << 32) | (u64) mp->session_index;
 
-  p = hash_get (utm->session_index_by_vpp_handles, key);
+  p = hash_get (utm->session_index_by_vpp_handles, mp->handle);
 
   if (p)
     {
       session = pool_elt_at_index (utm->sessions, p[0]);
-      hash_unset (utm->session_index_by_vpp_handles, key);
+      hash_unset (utm->session_index_by_vpp_handles, mp->handle);
       pool_put (utm->sessions, session);
     }
   else
     {
-      clib_warning ("couldn't find session key %llx", key);
+      clib_warning ("couldn't find session key %llx", mp->handle);
       rv = -11;
     }
 
@@ -592,77 +670,76 @@ vl_api_disconnect_session_t_handler (vl_api_disconnect_session_t * mp)
   memset (rmp, 0, sizeof (*rmp));
   rmp->_vl_msg_id = ntohs (VL_API_DISCONNECT_SESSION_REPLY);
   rmp->retval = rv;
-  rmp->session_index = mp->session_index;
-  rmp->session_thread_index = mp->session_thread_index;
+  rmp->handle = mp->handle;
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & rmp);
 }
 
 static void
 vl_api_connect_uri_reply_t_handler (vl_api_connect_uri_reply_t * mp)
 {
-  svm_fifo_segment_main_t *sm = &svm_fifo_segment_main;
   uri_udp_test_main_t *utm = &uri_udp_test_main;
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  ssvm_shared_header_t *sh;
-  svm_fifo_segment_private_t *seg;
-  svm_fifo_segment_header_t *fsh;
-  session_t *session;
-  u32 segment_index;
-  int rv;
 
   ASSERT (utm->i_am_master == 0);
 
-  if (mp->segment_name_length == 0)
+  /* We've been redirected */
+  if (mp->segment_name_length > 0)
     {
-      clib_warning ("segment_name_length zero");
-      return;
-    }
-
-  memset (a, 0, sizeof (*a));
-
-  a->segment_name = (char *) mp->segment_name;
-
-  sleep (1);
-
-  rv = svm_fifo_segment_attach (a);
-  if (rv)
-    {
-      clib_warning ("sm_fifo_segment_create ('%v') failed", mp->segment_name);
-      return;
-    }
-
-  segment_index = vec_len (sm->segments) - 1;
+      svm_fifo_segment_main_t *sm = &svm_fifo_segment_main;
+      svm_fifo_segment_create_args_t _a, *a = &_a;
+      u32 segment_index;
+      session_t *session;
+      ssvm_shared_header_t *sh;
+      svm_fifo_segment_private_t *seg;
+      svm_fifo_segment_header_t *fsh;
+      int rv;
+
+      memset (a, 0, sizeof (*a));
+      a->segment_name = (char *) mp->segment_name;
+
+      sleep (1);
+
+      rv = svm_fifo_segment_attach (a);
+      if (rv)
+	{
+	  clib_warning ("sm_fifo_segment_create ('%v') failed",
+			mp->segment_name);
+	  return;
+	}
 
-  vec_add2 (utm->seg, seg, 1);
+      segment_index = vec_len (sm->segments) - 1;
+      vec_add2 (utm->seg, seg, 1);
 
-  memcpy (seg, sm->segments + segment_index, sizeof (*seg));
-  sh = seg->ssvm.sh;
-  fsh = (svm_fifo_segment_header_t *) sh->opaque[0];
+      memcpy (seg, sm->segments + segment_index, sizeof (*seg));
+      sh = seg->ssvm.sh;
+      fsh = (svm_fifo_segment_header_t *) sh->opaque[0];
 
-  while (vec_len (fsh->fifos) < 2)
-    sleep (1);
+      while (vec_len (fsh->fifos) < 2)
+	sleep (1);
 
-  pool_get (utm->sessions, session);
-  utm->cut_through_session_index = session - utm->sessions;
+      pool_get (utm->sessions, session);
+      utm->cut_through_session_index = session - utm->sessions;
 
-  session->server_rx_fifo = (svm_fifo_t *) fsh->fifos[0];
-  ASSERT (session->server_rx_fifo);
-  session->server_tx_fifo = (svm_fifo_t *) fsh->fifos[1];
-  ASSERT (session->server_tx_fifo);
+      session->server_rx_fifo = (svm_fifo_t *) fsh->fifos[0];
+      ASSERT (session->server_rx_fifo);
+      session->server_tx_fifo = (svm_fifo_t *) fsh->fifos[1];
+      ASSERT (session->server_tx_fifo);
+    }
 
   /* security: could unlink /dev/shm/<mp->segment_name> here, maybe */
 
   utm->state = STATE_READY;
 }
 
-#define foreach_uri_msg                         \
-_(BIND_URI_REPLY, bind_uri_reply)               \
-_(CONNECT_URI, connect_uri)                     \
-_(CONNECT_URI_REPLY, connect_uri_reply)         \
-_(UNBIND_URI_REPLY, unbind_uri_reply)           \
-_(ACCEPT_SESSION, accept_session)		\
-_(DISCONNECT_SESSION, disconnect_session)	\
-_(MAP_ANOTHER_SEGMENT, map_another_segment)
+#define foreach_uri_msg                         	\
+_(BIND_URI_REPLY, bind_uri_reply)               	\
+_(CONNECT_URI, connect_uri)                     	\
+_(CONNECT_URI_REPLY, connect_uri_reply)         	\
+_(UNBIND_URI_REPLY, unbind_uri_reply)           	\
+_(ACCEPT_SESSION, accept_session)			\
+_(DISCONNECT_SESSION, disconnect_session)		\
+_(MAP_ANOTHER_SEGMENT, map_another_segment)		\
+_(APPLICATION_ATTACH_REPLY, application_attach_reply)	\
+_(APPLICATION_DETACH_REPLY, application_detach_reply)	\
 
 void
 uri_api_hookup (uri_udp_test_main_t * utm)
@@ -679,7 +756,6 @@ uri_api_hookup (uri_udp_test_main_t * utm)
 
 }
 
-
 int
 connect_to_vpp (char *name)
 {
@@ -784,26 +860,43 @@ server_handle_event_queue (uri_udp_test_main_t * utm)
     }
 }
 
-void
-uri_udp_test (uri_udp_test_main_t * utm)
+static void
+server_unbind (uri_udp_test_main_t * utm)
 {
-  vl_api_bind_uri_t *bmp;
   vl_api_unbind_uri_t *ump;
 
+  ump = vl_msg_api_alloc (sizeof (*ump));
+  memset (ump, 0, sizeof (*ump));
+
+  ump->_vl_msg_id = ntohs (VL_API_UNBIND_URI);
+  ump->client_index = utm->my_client_index;
+  memcpy (ump->uri, utm->uri, vec_len (utm->uri));
+  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & ump);
+}
+
+static void
+server_listen (uri_udp_test_main_t * utm)
+{
+  vl_api_bind_uri_t *bmp;
+
   bmp = vl_msg_api_alloc (sizeof (*bmp));
   memset (bmp, 0, sizeof (*bmp));
 
   bmp->_vl_msg_id = ntohs (VL_API_BIND_URI);
   bmp->client_index = utm->my_client_index;
   bmp->context = ntohl (0xfeedface);
-  bmp->initial_segment_size = 256 << 20;	/* size of initial segment */
-  bmp->options[SESSION_OPTIONS_FLAGS] =
-    SESSION_OPTIONS_FLAGS_USE_FIFO | SESSION_OPTIONS_FLAGS_ADD_SEGMENT;
-  bmp->options[SESSION_OPTIONS_RX_FIFO_SIZE] = 16 << 10;
-  bmp->options[SESSION_OPTIONS_TX_FIFO_SIZE] = 16 << 10;
-  bmp->options[SESSION_OPTIONS_ADD_SEGMENT_SIZE] = 128 << 20;
   memcpy (bmp->uri, utm->uri, vec_len (utm->uri));
   vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & bmp);
+}
+
+void
+udp_server_test (uri_udp_test_main_t * utm)
+{
+
+  application_attach (utm);
+
+  /* Bind to uri */
+  server_listen (utm);
 
   if (wait_for_state_change (utm, STATE_READY))
     {
@@ -813,13 +906,8 @@ uri_udp_test (uri_udp_test_main_t * utm)
 
   server_handle_event_queue (utm);
 
-  ump = vl_msg_api_alloc (sizeof (*ump));
-  memset (ump, 0, sizeof (*ump));
-
-  ump->_vl_msg_id = ntohs (VL_API_UNBIND_URI);
-  ump->client_index = utm->my_client_index;
-  memcpy (ump->uri, utm->uri, vec_len (utm->uri));
-  vl_msg_api_send_shmem (utm->vl_input_queue, (u8 *) & ump);
+  /* Cleanup */
+  server_unbind (utm);
 
   if (wait_for_state_change (utm, STATE_START))
     {
@@ -827,6 +915,8 @@ uri_udp_test (uri_udp_test_main_t * utm)
       return;
     }
 
+  application_detach (utm);
+
   fformat (stdout, "Test complete...\n");
 }
 
@@ -892,7 +982,7 @@ main (int argc, char **argv)
   utm->i_am_master = i_am_master;
   utm->segment_main = &svm_fifo_segment_main;
 
-  utm->connect_uri = format (0, "udp://10.0.0.1/1234%c", 0);
+  utm->connect_uri = format (0, "udp://6.0.0.1/1234%c", 0);
 
   setup_signal_handlers ();
 
@@ -907,7 +997,7 @@ main (int argc, char **argv)
 
   if (i_am_master == 0)
     {
-      uri_udp_slave_test (utm);
+      uri_udp_client_test (utm);
       exit (0);
     }
 
@@ -920,7 +1010,7 @@ main (int argc, char **argv)
   for (i = 0; i < 200000; i++)
     pool_put_index (utm->sessions, i);
 
-  uri_udp_test (utm);
+  udp_server_test (utm);
 
   vl_client_disconnect_from_vlib ();
   exit (0);