Add VPP Communications Library (VCL)

- VCL library
- client/server test application
- test script (make test integration tbd)
- gdb command file templates
- vppcom test config file

Change-Id: I21eab7aa09b4e5dc3412acf5c2eab07415c2fc0f
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

1 files changed, 2453 insertions, 0 deletions

diff --git a/src/uri/vppcom.c b/src/uri/vppcom.c
new file mode 100644
index 00000000000..44208cc0d82
--- /dev/null
+++ b/src/uri/vppcom.c
@@ -0,0 +1,2453 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <svm/svm_fifo_segment.h>
+#include <vlibmemory/api.h>
+#include <vpp/api/vpe_msg_enum.h>
+#include <vnet/session/application_interface.h>
+#include <uri/vppcom.h>
+#include <vlib/unix/unix.h>
+#include <vppinfra/vec_bootstrap.h>
+
+#define vl_typedefs		/* define message structures */
+#include <vpp/api/vpe_all_api_h.h>
+#undef vl_typedefs
+
+/* declare message handlers for each api */
+
+#define vl_endianfun		/* define message structures */
+#include <vpp/api/vpe_all_api_h.h>
+#undef vl_endianfun
+
+/* instantiate all the print functions we know about */
+#define vl_print(handle, ...)
+#define vl_printfun
+#include <vpp/api/vpe_all_api_h.h>
+#undef vl_printfun
+
+#if (CLIB_DEBUG > 0)
+/* Set VPPCOM_DEBUG 2 for connection debug, 3 for read/write debug output */
+#define VPPCOM_DEBUG 1
+#else
+#define VPPCOM_DEBUG 0
+#endif
+
+/*
+ * VPPCOM Private definitions and functions.
+ */
+typedef enum
+{
+  STATE_APP_START,
+  STATE_APP_CONN_VPP,
+  STATE_APP_ENABLED,
+  STATE_APP_ATTACHED,
+} app_state_t;
+
+typedef enum
+{
+  STATE_START,
+  STATE_CONNECT,
+  STATE_LISTEN,
+  STATE_ACCEPT,
+  STATE_DISCONNECT,
+  STATE_FAILED
+} session_state_t;
+
+typedef struct
+{
+  volatile session_state_t state;
+
+  svm_fifo_t *server_rx_fifo;
+  svm_fifo_t *server_tx_fifo;
+  u32 sm_seg_index;
+  u64 vpp_session_handle;
+  unix_shared_memory_queue_t *event_queue;
+
+  /* Socket configuration state */
+  u8 is_server;
+  u8 is_listen;
+  u8 is_cut_thru;
+  u8 is_nonblocking;
+  u32 vrf;
+  u8 is_ip4;
+  u8 ip[16];
+  u16 port;
+  u8 proto;
+  u64 client_queue_address;
+  u64 options[16];
+} session_t;
+
+typedef struct vppcom_cfg_t_
+{
+  u64 heapsize;
+  u64 segment_baseva;
+  u32 segment_size;
+  u32 add_segment_size;
+  u32 preallocated_fifo_pairs;
+  u32 rx_fifo_size;
+  u32 tx_fifo_size;
+  u32 event_queue_size;
+  u32 listen_queue_size;
+  f64 app_timeout;
+  f64 session_timeout;
+  f64 accept_timeout;
+} vppcom_cfg_t;
+
+typedef struct vppcom_main_t_
+{
+  u8 init;
+  u32 *client_session_index_fifo;
+  volatile u32 bind_session_index;
+  u32 tx_event_id;
+  int main_cpu;
+
+  /* vpe input queue */
+  unix_shared_memory_queue_t *vl_input_queue;
+
+  /* API client handle */
+  u32 my_client_index;
+
+  /* Session pool */
+  clib_spinlock_t sessions_lockp;
+  session_t *sessions;
+
+  /* Hash table for disconnect processing */
+  uword *session_index_by_vpp_handles;
+
+  /* Select bitmaps */
+  clib_bitmap_t *rd_bitmap;
+  clib_bitmap_t *wr_bitmap;
+  clib_bitmap_t *ex_bitmap;
+
+  /* Our event queue */
+  unix_shared_memory_queue_t *app_event_queue;
+
+  /* unique segment name counter */
+  u32 unique_segment_index;
+
+  pid_t my_pid;
+
+  /* For deadman timers */
+  clib_time_t clib_time;
+
+  /* State of the connection, shared between msg RX thread and main thread */
+  volatile app_state_t app_state;
+
+  vppcom_cfg_t cfg;
+
+  /* VNET_API_ERROR_FOO -> "Foo" hash table */
+  uword *error_string_by_error_number;
+} vppcom_main_t;
+
+vppcom_main_t vppcom_main = {.my_client_index = ~0 };
+
+static const char *
+vppcom_app_state_str (app_state_t state)
+{
+  char *st;
+
+  switch (state)
+    {
+    case STATE_APP_START:
+      st = "STATE_APP_START";
+      break;
+
+    case STATE_APP_CONN_VPP:
+      st = "STATE_APP_CONN_VPP";
+      break;
+
+    case STATE_APP_ENABLED:
+      st = "STATE_APP_ENABLED";
+      break;
+
+    case STATE_APP_ATTACHED:
+      st = "STATE_APP_ATTACHED";
+      break;
+
+    default:
+      st = "UNKNOWN_APP_STATE";
+      break;
+    }
+
+  return st;
+}
+
+static const char *
+vppcom_session_state_str (session_state_t state)
+{
+  char *st;
+
+  switch (state)
+    {
+    case STATE_START:
+      st = "STATE_START";
+      break;
+
+    case STATE_CONNECT:
+      st = "STATE_CONNECT";
+      break;
+
+    case STATE_LISTEN:
+      st = "STATE_LISTEN";
+      break;
+
+    case STATE_ACCEPT:
+      st = "STATE_ACCEPT";
+      break;
+
+    case STATE_DISCONNECT:
+      st = "STATE_DISCONNECT";
+      break;
+
+    case STATE_FAILED:
+      st = "STATE_FAILED";
+      break;
+
+    default:
+      st = "UNKNOWN_STATE";
+      break;
+    }
+
+  return st;
+}
+
+/*
+ * VPPCOM Utility Functions
+ */
+static inline int
+vppcom_session_at_index (u32 session_index, session_t * volatile *sess)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+
+  /* Assumes that caller has acquired spinlock: vcm->sessions_lockp */
+  if (PREDICT_FALSE ((session_index == ~0) ||
+		     pool_is_free_index (vcm->sessions, session_index)))
+    {
+      clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		    vcm->my_pid, session_index);
+      return VPPCOM_EBADFD;
+    }
+  *sess = pool_elt_at_index (vcm->sessions, session_index);
+  return VPPCOM_OK;
+}
+
+static int
+vppcom_connect_to_vpp (char *app_name)
+{
+  api_main_t *am = &api_main;
+  vppcom_main_t *vcm = &vppcom_main;
+
+  if (VPPCOM_DEBUG > 0)
+    printf ("\nConnecting to VPP api...");
+  if (vl_client_connect_to_vlib ("/vpe-api", app_name, 32) < 0)
+    {
+      clib_warning ("[%d] connect to vpp (%s) failed!",
+		    vcm->my_pid, app_name);
+      return VPPCOM_ECONNREFUSED;
+    }
+
+  vcm->vl_input_queue = am->shmem_hdr->vl_input_queue;
+  vcm->my_client_index = am->my_client_index;
+  if (VPPCOM_DEBUG > 0)
+    printf (" connected!\n");
+
+  vcm->app_state = STATE_APP_CONN_VPP;
+  return VPPCOM_OK;
+}
+
+static u8 *
+format_api_error (u8 * s, va_list * args)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  i32 error = va_arg (*args, u32);
+  uword *p;
+
+  p = hash_get (vcm->error_string_by_error_number, -error);
+
+  if (p)
+    s = format (s, "%s (%d)", p[0], error);
+  else
+    s = format (s, "%d", error);
+  return s;
+}
+
+static void
+vppcom_init_error_string_table (void)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+
+  vcm->error_string_by_error_number = hash_create (0, sizeof (uword));
+
+#define _(n,v,s) hash_set (vcm->error_string_by_error_number, -v, s);
+  foreach_vnet_api_error;
+#undef _
+
+  hash_set (vcm->error_string_by_error_number, 99, "Misc");
+}
+
+static inline int
+vppcom_wait_for_app_state_change (app_state_t app_state)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  f64 timeout = clib_time_now (&vcm->clib_time) + vcm->cfg.app_timeout;
+
+  while (clib_time_now (&vcm->clib_time) < timeout)
+    {
+      if (vcm->app_state == app_state)
+	return VPPCOM_OK;
+    }
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] timeout waiting for state %s (%d)", vcm->my_pid,
+		  vppcom_app_state_str (app_state), app_state);
+  return VPPCOM_ETIMEDOUT;
+}
+
+static inline int
+vppcom_wait_for_session_state_change (u32 session_index,
+				      session_state_t state,
+				      f64 wait_for_time)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  f64 timeout = clib_time_now (&vcm->clib_time) + wait_for_time;
+  session_t *volatile session;
+  int rv;
+
+  do
+    {
+      clib_spinlock_lock (&vcm->sessions_lockp);
+      rv = vppcom_session_at_index (session_index, &session);
+      if (PREDICT_FALSE (rv))
+	{
+	  clib_spinlock_unlock (&vcm->sessions_lockp);
+	  return rv;
+	}
+      if (session->state == state)
+	{
+	  clib_spinlock_unlock (&vcm->sessions_lockp);
+	  return VPPCOM_OK;
+	}
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+    }
+  while (clib_time_now (&vcm->clib_time) < timeout);
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] timeout waiting for state %s (%d)", vcm->my_pid,
+		  vppcom_session_state_str (state), state);
+  return VPPCOM_ETIMEDOUT;
+}
+
+static inline int
+vppcom_wait_for_client_session_index (f64 wait_for_time)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  f64 timeout = clib_time_now (&vcm->clib_time) + wait_for_time;
+
+  do
+    {
+      if (clib_fifo_elts (vcm->client_session_index_fifo))
+	return VPPCOM_OK;
+    }
+  while (clib_time_now (&vcm->clib_time) < timeout);
+
+  if (wait_for_time == 0)
+    return VPPCOM_EAGAIN;
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] timeout waiting for client_session_index",
+		  vcm->my_pid);
+  return VPPCOM_ETIMEDOUT;
+}
+
+/*
+ * VPP-API message functions
+ */
+static void
+vppcom_send_session_enable_disable (u8 is_enable)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_session_enable_disable_t *bmp;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_SESSION_ENABLE_DISABLE);
+  bmp->client_index = vcm->my_client_index;
+  bmp->context = htonl (0xfeedface);
+  bmp->is_enable = is_enable;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & bmp);
+}
+
+static int
+vppcom_app_session_enable (void)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  int rv;
+
+  if (vcm->app_state != STATE_APP_ENABLED)
+    {
+      vppcom_send_session_enable_disable (1 /* is_enabled == TRUE */ );
+      rv = vppcom_wait_for_app_state_change (STATE_APP_ENABLED);
+      if (PREDICT_FALSE (rv))
+	{
+	  if (VPPCOM_DEBUG > 0)
+	    clib_warning ("[%d] Session enable timed out, rv = %s (%d)",
+			  vcm->my_pid, vppcom_retval_str (rv), rv);
+	  return rv;
+	}
+    }
+  return VPPCOM_OK;
+}
+
+static void
+  vl_api_session_enable_disable_reply_t_handler
+  (vl_api_session_enable_disable_reply_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+
+  if (mp->retval)
+    {
+      clib_warning ("[%d] session_enable_disable failed: %U", vcm->my_pid,
+		    format_api_error, ntohl (mp->retval));
+    }
+  else
+    vcm->app_state = STATE_APP_ENABLED;
+}
+
+static void
+vppcom_app_send_attach (void)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_application_attach_t *bmp;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_APPLICATION_ATTACH);
+  bmp->client_index = vcm->my_client_index;
+  bmp->context = htonl (0xfeedface);
+  bmp->options[APP_OPTIONS_FLAGS] =
+    APP_OPTIONS_FLAGS_USE_FIFO | APP_OPTIONS_FLAGS_ADD_SEGMENT;
+  bmp->options[SESSION_OPTIONS_SEGMENT_SIZE] = vcm->cfg.segment_size;
+  bmp->options[SESSION_OPTIONS_ADD_SEGMENT_SIZE] = vcm->cfg.add_segment_size;
+  bmp->options[SESSION_OPTIONS_RX_FIFO_SIZE] = vcm->cfg.rx_fifo_size;
+  bmp->options[SESSION_OPTIONS_TX_FIFO_SIZE] = vcm->cfg.tx_fifo_size;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & bmp);
+}
+
+static int
+vppcom_app_attach (void)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  int rv;
+
+  vppcom_app_send_attach ();
+  rv = vppcom_wait_for_app_state_change (STATE_APP_ATTACHED);
+  if (PREDICT_FALSE (rv))
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] application attach timed out, rv = %s (%d)",
+		      vcm->my_pid, vppcom_retval_str (rv), rv);
+      return rv;
+    }
+  return VPPCOM_OK;
+}
+
+static void
+vppcom_app_detach (void)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  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 = vcm->my_client_index;
+  bmp->context = htonl (0xfeedface);
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & bmp);
+}
+
+static void
+vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
+					   mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  static svm_fifo_segment_create_args_t _a;
+  svm_fifo_segment_create_args_t *a = &_a;
+  int rv;
+
+  memset (a, 0, sizeof (*a));
+  if (mp->retval)
+    {
+      clib_warning ("[%d] attach failed: %U", vcm->my_pid,
+		    format_api_error, ntohl (mp->retval));
+      return;
+    }
+
+  if (mp->segment_name_length == 0)
+    {
+      clib_warning ("[%d] segment_name_length zero", vcm->my_pid);
+      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);
+  vec_reset_length (a->new_segment_indices);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_warning ("[%d] svm_fifo_segment_attach ('%s') failed", vcm->my_pid,
+		    mp->segment_name);
+      return;
+    }
+
+  vcm->app_event_queue =
+    uword_to_pointer (mp->app_event_queue_address,
+		      unix_shared_memory_queue_t *);
+
+  vcm->app_state = STATE_APP_ATTACHED;
+}
+
+static void
+vl_api_application_detach_reply_t_handler (vl_api_application_detach_reply_t *
+					   mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+
+  if (mp->retval)
+    clib_warning ("[%d] detach failed: %U", vcm->my_pid, format_api_error,
+		  ntohl (mp->retval));
+
+  vcm->app_state = STATE_APP_ENABLED;
+}
+
+static void
+vl_api_disconnect_session_reply_t_handler (vl_api_disconnect_session_reply_t *
+					   mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  uword *p;
+
+  p = hash_get (vcm->session_index_by_vpp_handles, mp->handle);
+  if (p)
+    {
+      session_t *session = 0;
+      int rv;
+      clib_spinlock_lock (&vcm->sessions_lockp);
+      rv = vppcom_session_at_index (p[0], &session);
+      if (PREDICT_FALSE (rv))
+	{
+	  if (VPPCOM_DEBUG > 1)
+	    clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+			  vcm->my_pid, p[0]);
+	}
+      hash_unset (vcm->session_index_by_vpp_handles, mp->handle);
+      session->state = STATE_DISCONNECT;
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+    }
+  else
+    {
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] couldn't find session key %llx", vcm->my_pid,
+		      mp->handle);
+    }
+
+  if (mp->retval)
+    clib_warning ("[%d] disconnect_session failed: %U", vcm->my_pid,
+		  format_api_error, ntohl (mp->retval));
+}
+
+static void
+vl_api_map_another_segment_t_handler (vl_api_map_another_segment_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  static svm_fifo_segment_create_args_t _a;
+  svm_fifo_segment_create_args_t *a = &_a;
+  int rv;
+
+  memset (a, 0, sizeof (*a));
+  a->segment_name = (char *) mp->segment_name;
+  a->segment_size = mp->segment_size;
+  /* Attach to the segment vpp created */
+  rv = svm_fifo_segment_attach (a);
+  vec_reset_length (a->new_segment_indices);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_warning ("[%d] svm_fifo_segment_attach ('%s') failed",
+		    vcm->my_pid, mp->segment_name);
+      return;
+    }
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("[%d] mapped new segment '%s' size %d", vcm->my_pid,
+		  mp->segment_name, mp->segment_size);
+}
+
+static void
+vl_api_disconnect_session_t_handler (vl_api_disconnect_session_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  vl_api_disconnect_session_reply_t *rmp;
+  uword *p;
+  int rv = 0;
+
+  p = hash_get (vcm->session_index_by_vpp_handles, mp->handle);
+  if (p)
+    {
+      int rval;
+      clib_spinlock_lock (&vcm->sessions_lockp);
+      rval = vppcom_session_at_index (p[0], &session);
+      if (PREDICT_FALSE (rval))
+	{
+	  if (VPPCOM_DEBUG > 1)
+	    clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+			  vcm->my_pid, p[0]);
+	}
+      else
+	pool_put (vcm->sessions, session);
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      hash_unset (vcm->session_index_by_vpp_handles, mp->handle);
+    }
+  else
+    {
+      clib_warning ("[%d] couldn't find session key %llx", vcm->my_pid,
+		    mp->handle);
+      rv = -11;
+    }
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+
+  rmp->_vl_msg_id = ntohs (VL_API_DISCONNECT_SESSION_REPLY);
+  rmp->retval = htonl (rv);
+  rmp->handle = mp->handle;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+}
+
+static void
+vl_api_reset_session_t_handler (vl_api_reset_session_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  vl_api_reset_session_reply_t *rmp;
+  uword *p;
+  int rv = 0;
+
+  p = hash_get (vcm->session_index_by_vpp_handles, mp->handle);
+  if (p)
+    {
+      int rval;
+      clib_spinlock_lock (&vcm->sessions_lockp);
+      rval = vppcom_session_at_index (p[0], &session);
+      if (PREDICT_FALSE (rval))
+	{
+	  if (VPPCOM_DEBUG > 1)
+	    clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+			  vcm->my_pid, p[0]);
+	}
+      else
+	pool_put (vcm->sessions, session);
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      hash_unset (vcm->session_index_by_vpp_handles, mp->handle);
+    }
+  else
+    {
+      clib_warning ("[%d] couldn't find session key %llx", vcm->my_pid,
+		    mp->handle);
+      rv = -11;
+    }
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_RESET_SESSION_REPLY);
+  rmp->retval = htonl (rv);
+  rmp->handle = mp->handle;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+}
+
+static void
+vl_api_connect_sock_reply_t_handler (vl_api_connect_sock_reply_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session;
+  u32 session_index;
+  svm_fifo_t *rx_fifo, *tx_fifo;
+  u8 is_cut_thru = 0;
+  int rv;
+
+  if (mp->retval)
+    {
+      clib_warning ("[%d] connect failed: %U", vcm->my_pid, format_api_error,
+		    ntohl (mp->retval));
+      return;
+    }
+
+  session_index = ntohl (mp->app_connect);
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("[%d] app_connect = %d 0x%08x", vcm->my_pid,
+		  session_index, session_index);
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  if (pool_is_free_index (vcm->sessions, session_index))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] invalid session, sid %d is closed!",
+		      vcm->my_pid, session_index);
+      return;
+    }
+
+  /* We've been redirected */
+  if (mp->segment_name_length > 0)
+    {
+      static svm_fifo_segment_create_args_t _a;
+      svm_fifo_segment_create_args_t *a = &_a;
+
+      is_cut_thru = 1;
+      memset (a, 0, sizeof (*a));
+      a->segment_name = (char *) mp->segment_name;
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] cut-thru segment: %s", vcm->my_pid,
+		      a->segment_name);
+      rv = svm_fifo_segment_attach (a);
+      vec_reset_length (a->new_segment_indices);
+      if (PREDICT_FALSE (rv))
+	{
+	  clib_warning ("[%d] sm_fifo_segment_attach ('%s') failed",
+			vcm->my_pid, a->segment_name);
+	  return;
+	}
+    }
+
+  /*
+   * Setup session
+   */
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("[%d] client sid %d", vcm->my_pid, session_index);
+
+  session = pool_elt_at_index (vcm->sessions, session_index);
+  session->is_cut_thru = is_cut_thru;
+  session->event_queue = uword_to_pointer (mp->vpp_event_queue_address,
+					   unix_shared_memory_queue_t *);
+
+  rx_fifo = uword_to_pointer (mp->server_rx_fifo, svm_fifo_t *);
+  rx_fifo->client_session_index = session_index;
+  tx_fifo = uword_to_pointer (mp->server_tx_fifo, svm_fifo_t *);
+  tx_fifo->client_session_index = session_index;
+
+  session->server_rx_fifo = rx_fifo;
+  session->server_tx_fifo = tx_fifo;
+  session->vpp_session_handle = mp->handle;
+  session->state = STATE_CONNECT;
+
+  /* Add it to lookup table */
+  hash_set (vcm->session_index_by_vpp_handles, mp->handle, session_index);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+}
+
+static void
+vppcom_send_connect_sock (session_t * session, u32 session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_connect_sock_t *cmp;
+
+  /* Assumes caller as acquired the spinlock: vcm->sessions_lockp */
+  session->is_server = 0;
+  cmp = vl_msg_api_alloc (sizeof (*cmp));
+  memset (cmp, 0, sizeof (*cmp));
+  cmp->_vl_msg_id = ntohs (VL_API_CONNECT_SOCK);
+  cmp->client_index = vcm->my_client_index;
+  cmp->context = htonl (0xfeedface);
+  cmp->app_connect = session_index;
+
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("[%d] session_index = %d 0x%08x, app_connect = %d 0x%08x",
+		  vcm->my_pid, session_index, session_index,
+		  cmp->app_connect, cmp->app_connect);
+
+  cmp->vrf = session->vrf;
+  cmp->is_ip4 = session->is_ip4;
+  clib_memcpy (cmp->ip, session->ip, (session->is_ip4 ?
+				      sizeof (ip4_address_t) :
+				      sizeof (ip6_address_t)));
+  cmp->port = session->port;
+  cmp->proto = session->proto;
+  clib_memcpy (cmp->options, session->options, sizeof (cmp->options));
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & cmp);
+}
+
+static int
+vppcom_send_disconnect (u32 session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_disconnect_session_t *dmp;
+  session_t *session = 0;
+  int rv;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+
+  dmp = vl_msg_api_alloc (sizeof (*dmp));
+  memset (dmp, 0, sizeof (*dmp));
+  dmp->_vl_msg_id = ntohs (VL_API_DISCONNECT_SESSION);
+  dmp->client_index = vcm->my_client_index;
+  dmp->handle = session->vpp_session_handle;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & dmp);
+  return VPPCOM_OK;
+}
+
+static void
+vl_api_bind_sock_reply_t_handler (vl_api_bind_sock_reply_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  int rv;
+
+  if (mp->retval)
+    clib_warning ("[%d] bind failed: %U", vcm->my_pid, format_api_error,
+		  ntohl (mp->retval));
+
+  ASSERT (vcm->bind_session_index != ~0);
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (vcm->bind_session_index, &session);
+  if (rv == VPPCOM_OK)
+    {
+      session->vpp_session_handle = mp->handle;
+      hash_set (vcm->session_index_by_vpp_handles, mp->handle,
+		vcm->bind_session_index);
+      session->state = mp->retval ? STATE_FAILED : STATE_LISTEN;
+      vcm->bind_session_index = ~0;
+    }
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+}
+
+static void
+vl_api_unbind_sock_reply_t_handler (vl_api_unbind_sock_reply_t * mp)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  int rv;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (vcm->bind_session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, vcm->bind_session_index);
+    }
+
+  if (mp->retval)
+    clib_warning ("[%d] unbind failed: %U", vcm->my_pid, format_api_error,
+		  ntohl (mp->retval));
+
+  vcm->bind_session_index = ~0;
+  session->state = STATE_START;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+}
+
+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)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_accept_session_reply_t *rmp;
+  svm_fifo_t *rx_fifo, *tx_fifo;
+  session_t *session;
+  u32 session_index;
+  int rv = 0;
+
+  if (!clib_fifo_free_elts (vcm->client_session_index_fifo))
+    {
+      clib_warning ("[%d] client session queue is full!", vcm->my_pid);
+      rv = VNET_API_ERROR_QUEUE_FULL;
+      goto send_reply;
+    }
+
+  if (VPPCOM_DEBUG > 1)
+    {
+      u8 *ip_str = format (0, "%U", format_ip46_address, &mp->ip, mp->is_ip4);
+      clib_warning ("[%d] accepted session from: %s:%d", vcm->my_pid, ip_str,
+		    clib_net_to_host_u16 (mp->port));
+      vec_free (ip_str);
+    }
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  /* Allocate local session and set it up */
+  pool_get (vcm->sessions, session);
+  memset (session, 0, sizeof (*session));
+  session_index = session - vcm->sessions;
+
+  rx_fifo = uword_to_pointer (mp->server_rx_fifo, svm_fifo_t *);
+  rx_fifo->client_session_index = session_index;
+  tx_fifo = uword_to_pointer (mp->server_tx_fifo, svm_fifo_t *);
+  tx_fifo->client_session_index = session_index;
+
+  session->server_rx_fifo = rx_fifo;
+  session->server_tx_fifo = tx_fifo;
+  session->event_queue = uword_to_pointer (mp->vpp_event_queue_address,
+					   unix_shared_memory_queue_t *);
+  session->state = STATE_ACCEPT;
+  session->is_cut_thru = 0;
+  session->port = ntohs (mp->port);
+  session->is_ip4 = mp->is_ip4;
+  clib_memcpy (session->ip, mp->ip, (mp->is_ip4 ?
+				     sizeof (ip4_address_t) :
+				     sizeof (ip6_address_t)));
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  /* Add it to lookup table */
+  hash_set (vcm->session_index_by_vpp_handles, mp->handle, session_index);
+
+  clib_fifo_add1 (vcm->client_session_index_fifo, session_index);
+
+  /*
+   * Send accept reply to vpp
+   */
+send_reply:
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_ACCEPT_SESSION_REPLY);
+  rmp->retval = htonl (rv);
+  rmp->handle = mp->handle;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+}
+
+/*
+ * Acting as server for redirected connect requests
+ */
+static void
+vl_api_connect_sock_t_handler (vl_api_connect_sock_t * mp)
+{
+  static svm_fifo_segment_create_args_t _a;
+  svm_fifo_segment_create_args_t *a = &_a;
+  vppcom_main_t *vcm = &vppcom_main;
+  u32 session_index;
+  svm_fifo_segment_private_t *seg;
+  unix_shared_memory_queue_t *client_q;
+  vl_api_connect_sock_reply_t *rmp;
+  session_t *session = 0;
+  int rv = 0;
+  svm_fifo_t *rx_fifo;
+  svm_fifo_t *tx_fifo;
+  unix_shared_memory_queue_t *event_q = 0;
+
+  if (!clib_fifo_free_elts (vcm->client_session_index_fifo))
+    {
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] client session queue is full!", vcm->my_pid);
+      rv = VNET_API_ERROR_QUEUE_FULL;
+      goto send_reply;
+    }
+
+  /* Create the segment */
+  memset (a, 0, sizeof (*a));
+  a->segment_name = (char *) format ((u8 *) a->segment_name, "%d:segment%d%c",
+				     vcm->my_pid, vcm->unique_segment_index++,
+				     0);
+  a->segment_size = vcm->cfg.segment_size;
+  a->preallocated_fifo_pairs = vcm->cfg.preallocated_fifo_pairs;
+  a->rx_fifo_size = vcm->cfg.rx_fifo_size;
+  a->tx_fifo_size = vcm->cfg.tx_fifo_size;
+
+  rv = svm_fifo_segment_create (a);
+  if (PREDICT_FALSE (rv))
+    {
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] svm_fifo_segment_create ('%s') failed",
+		      vcm->my_pid, a->segment_name);
+      vec_reset_length (a->new_segment_indices);
+      rv = VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+      goto send_reply;
+    }
+
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("[%d] created segment '%s'", vcm->my_pid, a->segment_name);
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  pool_get (vcm->sessions, session);
+  memset (session, 0, sizeof (*session));
+  session_index = session - vcm->sessions;
+
+  session->sm_seg_index = a->new_segment_indices[0];
+  vec_reset_length (a->new_segment_indices);
+
+  seg = svm_fifo_get_segment (session->sm_seg_index);
+  rx_fifo = session->server_rx_fifo =
+    svm_fifo_segment_alloc_fifo (seg, vcm->cfg.rx_fifo_size,
+				 FIFO_SEGMENT_RX_FREELIST);
+  if (PREDICT_FALSE (!session->server_rx_fifo))
+    {
+      svm_fifo_segment_delete (seg);
+      clib_warning ("[%d] rx fifo alloc failed, size %ld (0x%lx)",
+		    vcm->my_pid, vcm->cfg.rx_fifo_size,
+		    vcm->cfg.rx_fifo_size);
+      rv = VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      goto send_reply;
+    }
+
+  tx_fifo = session->server_tx_fifo =
+    svm_fifo_segment_alloc_fifo (seg, vcm->cfg.tx_fifo_size,
+				 FIFO_SEGMENT_TX_FREELIST);
+  if (PREDICT_FALSE (!session->server_tx_fifo))
+    {
+      svm_fifo_segment_delete (seg);
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] tx fifo alloc failed, size %ld (0x%lx)",
+		      vcm->my_pid, vcm->cfg.tx_fifo_size,
+		      vcm->cfg.tx_fifo_size);
+      rv = VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      goto send_reply;
+    }
+
+  session->server_rx_fifo->master_session_index = session_index;
+  session->server_tx_fifo->master_session_index = session_index;
+  session->client_queue_address = mp->client_queue_address;
+  session->is_cut_thru = 1;
+  session->is_server = 1;
+  session->is_ip4 = mp->is_ip4;
+  session->port = mp->port;
+  {
+    void *oldheap;
+    ssvm_shared_header_t *sh = seg->ssvm.sh;
+
+    ssvm_lock_non_recursive (sh, 1);
+    oldheap = ssvm_push_heap (sh);
+    event_q = session->event_queue =
+      unix_shared_memory_queue_init (vcm->cfg.event_queue_size,
+				     sizeof (session_fifo_event_t),
+				     vcm->my_pid, 0 /* signal not sent */ );
+    ssvm_pop_heap (oldheap);
+    ssvm_unlock_non_recursive (sh);
+  }
+  clib_memcpy (session->ip, mp->ip, (mp->is_ip4 ?
+				     sizeof (ip4_address_t) :
+				     sizeof (ip6_address_t)));
+  session->state = STATE_ACCEPT;
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("[%d] Connected cut-thru to client: sid %d",
+		  vcm->my_pid, session_index);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  clib_fifo_add1 (vcm->client_session_index_fifo, session_index);
+
+send_reply:
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+
+  rmp->_vl_msg_id = ntohs (VL_API_CONNECT_SOCK_REPLY);
+  rmp->context = mp->context;
+  rmp->app_connect = htonl (mp->app_connect);
+  rmp->retval = htonl (rv);
+  rmp->segment_name_length = vec_len (a->segment_name);
+  clib_memcpy (rmp->segment_name, a->segment_name, vec_len (a->segment_name));
+  vec_reset_length (a->segment_name);
+
+  if (event_q)
+    {
+      rmp->vpp_event_queue_address = pointer_to_uword (event_q);
+      rmp->server_rx_fifo = pointer_to_uword (rx_fifo);
+      rmp->server_tx_fifo = pointer_to_uword (tx_fifo);
+    }
+  client_q =
+    uword_to_pointer (mp->client_queue_address, unix_shared_memory_queue_t *);
+
+  ASSERT (client_q);
+  vl_msg_api_send_shmem (client_q, (u8 *) & rmp);
+}
+
+static void
+vppcom_send_bind_sock (session_t * session)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_bind_sock_t *bmp;
+
+  /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
+  session->is_server = 1;
+  bmp = vl_msg_api_alloc (sizeof (*bmp));
+  memset (bmp, 0, sizeof (*bmp));
+
+  bmp->_vl_msg_id = ntohs (VL_API_BIND_SOCK);
+  bmp->client_index = vcm->my_client_index;
+  bmp->context = htonl (0xfeedface);
+  bmp->vrf = session->vrf;
+  bmp->is_ip4 = session->is_ip4;
+  clib_memcpy (bmp->ip, session->ip, (session->is_ip4 ?
+				      sizeof (ip4_address_t) :
+				      sizeof (ip6_address_t)));
+  bmp->port = session->port;
+  bmp->proto = session->proto;
+  clib_memcpy (bmp->options, session->options, sizeof (bmp->options));
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & bmp);
+}
+
+static void
+vppcom_send_unbind_sock (u32 session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vl_api_unbind_sock_t *ump;
+  session_t *session = 0;
+  int rv;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return;
+    }
+
+  ump = vl_msg_api_alloc (sizeof (*ump));
+  memset (ump, 0, sizeof (*ump));
+
+  ump->_vl_msg_id = ntohs (VL_API_UNBIND_SOCK);
+  ump->client_index = vcm->my_client_index;
+  ump->handle = session->vpp_session_handle;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & ump);
+}
+
+static int
+vppcom_session_unbind_cut_thru (session_t * session)
+{
+  svm_fifo_segment_main_t *sm = &svm_fifo_segment_main;
+  svm_fifo_segment_private_t *seg;
+  int rv = VPPCOM_OK;
+
+  seg = vec_elt_at_index (sm->segments, session->sm_seg_index);
+  svm_fifo_segment_free_fifo (seg, session->server_rx_fifo,
+			      FIFO_SEGMENT_RX_FREELIST);
+  svm_fifo_segment_free_fifo (seg, session->server_tx_fifo,
+			      FIFO_SEGMENT_TX_FREELIST);
+  svm_fifo_segment_delete (seg);
+
+  return rv;
+}
+
+static int
+vppcom_session_unbind (u32 session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  int rv;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  if (PREDICT_FALSE (pool_is_free_index (vcm->sessions, session_index)))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 1)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return VPPCOM_EBADFD;
+    }
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  vcm->bind_session_index = session_index;
+  vppcom_send_unbind_sock (session_index);
+  rv = vppcom_wait_for_session_state_change (session_index, STATE_START,
+					     vcm->cfg.session_timeout);
+  if (PREDICT_FALSE (rv))
+    {
+      vcm->bind_session_index = ~0;
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] server unbind timed out, rv = %s (%d)",
+		      vcm->my_pid, vppcom_retval_str (rv), rv);
+      return rv;
+    }
+  return VPPCOM_OK;
+}
+
+static int
+vppcom_session_disconnect (u32 session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  int rv;
+
+  rv = vppcom_send_disconnect (session_index);
+  if (PREDICT_FALSE (rv))
+    return rv;
+
+  rv = vppcom_wait_for_session_state_change (session_index, STATE_DISCONNECT,
+					     vcm->cfg.session_timeout);
+  if (PREDICT_FALSE (rv))
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] client disconnect timed out, rv = %s (%d)",
+		      vcm->my_pid, vppcom_retval_str (rv), rv);
+      return rv;
+    }
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  pool_put_index (vcm->sessions, session_index);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  return VPPCOM_OK;
+}
+
+#define foreach_sock_msg                                        \
+_(SESSION_ENABLE_DISABLE_REPLY, session_enable_disable_reply)   \
+_(BIND_SOCK_REPLY, bind_sock_reply)                             \
+_(UNBIND_SOCK_REPLY, unbind_sock_reply)                         \
+_(ACCEPT_SESSION, accept_session)                               \
+_(CONNECT_SOCK, connect_sock)                                   \
+_(CONNECT_SOCK_REPLY, connect_sock_reply)                       \
+_(DISCONNECT_SESSION, disconnect_session)                       \
+_(DISCONNECT_SESSION_REPLY, disconnect_session_reply)           \
+_(RESET_SESSION, reset_session)                                 \
+_(APPLICATION_ATTACH_REPLY, application_attach_reply)           \
+_(APPLICATION_DETACH_REPLY, application_detach_reply)           \
+_(MAP_ANOTHER_SEGMENT, map_another_segment)
+
+static void
+vppcom_api_hookup (void)
+{
+#define _(N,n)                                                  \
+    vl_msg_api_set_handlers(VL_API_##N, #n,                     \
+                           vl_api_##n##_t_handler,              \
+                           vl_noop_handler,                     \
+                           vl_api_##n##_t_endian,               \
+                           vl_api_##n##_t_print,                \
+                           sizeof(vl_api_##n##_t), 1);
+  foreach_sock_msg;
+#undef _
+}
+
+static void
+vppcom_cfg_init (vppcom_cfg_t * vcl_cfg)
+{
+  ASSERT (vcl_cfg);
+
+  vcl_cfg->heapsize = (256ULL << 20);
+  vcl_cfg->segment_baseva = 0x200000000ULL;
+  vcl_cfg->segment_size = (256 << 20);
+  vcl_cfg->add_segment_size = (128 << 20);
+  vcl_cfg->preallocated_fifo_pairs = 8;
+  vcl_cfg->rx_fifo_size = (1 << 20);
+  vcl_cfg->tx_fifo_size = (1 << 20);
+  vcl_cfg->event_queue_size = 2048;
+  vcl_cfg->listen_queue_size = CLIB_CACHE_LINE_BYTES / sizeof (u32);
+  vcl_cfg->app_timeout = 10 * 60.0;
+  vcl_cfg->session_timeout = 10 * 60.0;
+  vcl_cfg->accept_timeout = 60.0;
+}
+
+static void
+vppcom_cfg_heapsize (char *conf_fname)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vppcom_cfg_t *vcl_cfg = &vcm->cfg;
+  FILE *fp;
+  char inbuf[4096];
+  int argc = 1;
+  char **argv = NULL;
+  char *arg = NULL;
+  char *p;
+  int i;
+  u8 *sizep;
+  u32 size;
+
+  fp = fopen (conf_fname, "r");
+  if (fp == NULL)
+    {
+      if (VPPCOM_DEBUG > 0)
+	fprintf (stderr, "open configuration file '%s' failed\n", conf_fname);
+      goto defaulted;
+    }
+  argv = calloc (1, sizeof (char *));
+  if (argv == NULL)
+    goto defaulted;
+
+  while (1)
+    {
+      if (fgets (inbuf, 4096, fp) == 0)
+	break;
+      p = strtok (inbuf, " \t\n");
+      while (p != NULL)
+	{
+	  if (*p == '#')
+	    break;
+	  argc++;
+	  char **tmp = realloc (argv, argc * sizeof (char *));
+	  if (tmp == NULL)
+	    {
+	      fclose (fp);
+	      goto defaulted;
+	    }
+	  argv = tmp;
+	  arg = strndup (p, 1024);
+	  if (arg == NULL)
+	    {
+	      fclose (fp);
+	      goto defaulted;
+	    }
+	  argv[argc - 1] = arg;
+	  p = strtok (NULL, " \t\n");
+	}
+    }
+
+  fclose (fp);
+
+  char **tmp = realloc (argv, (argc + 1) * sizeof (char *));
+  if (tmp == NULL)
+    goto defaulted;
+  argv = tmp;
+  argv[argc] = NULL;
+
+  /*
+   * Look for and parse the "heapsize" config parameter.
+   * Manual since none of the clib infra has been bootstrapped yet.
+   *
+   * Format: heapsize <nn>[mM][gG]
+   */
+
+  for (i = 1; i < (argc - 1); i++)
+    {
+      if (!strncmp (argv[i], "heapsize", 8))
+	{
+	  sizep = (u8 *) argv[i + 1];
+	  size = 0;
+	  while (*sizep >= '0' && *sizep <= '9')
+	    {
+	      size *= 10;
+	      size += *sizep++ - '0';
+	    }
+	  if (size == 0)
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] parse error '%s %s', "
+			      "using default heapsize %lld (0x%llx)",
+			      vcm->my_pid, argv[i], argv[i + 1],
+			      vcl_cfg->heapsize, vcl_cfg->heapsize);
+	      goto defaulted;
+	    }
+
+	  if (*sizep == 'g' || *sizep == 'G')
+	    vcl_cfg->heapsize = size << 30;
+	  else if (*sizep == 'm' || *sizep == 'M')
+	    vcl_cfg->heapsize = size << 20;
+	  else
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] parse error '%s %s', "
+			      "using default heapsize %lld (0x%llx)",
+			      vcm->my_pid, argv[i], argv[i + 1],
+			      vcl_cfg->heapsize, vcl_cfg->heapsize);
+	      goto defaulted;
+	    }
+	}
+    }
+
+defaulted:
+  if (!clib_mem_init (0, vcl_cfg->heapsize))
+    clib_warning ("[%d] vppcom heap allocation failure!", vcm->my_pid);
+  else if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] allocated vppcom heapsize %lld (0x%llx)",
+		  vcm->my_pid, vcl_cfg->heapsize, vcl_cfg->heapsize);
+}
+
+static void
+vppcom_cfg_read (char *conf_fname)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vppcom_cfg_t *vcl_cfg = &vcm->cfg;
+  int fd;
+  unformat_input_t _input, *input = &_input;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u8 vc_cfg_input = 0;
+  u8 *chroot_path;
+  struct stat s;
+  u32 uid, gid;
+
+  fd = open (conf_fname, O_RDONLY);
+  if (fd < 0)
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] open configuration file '%s' failed!",
+		      vcm->my_pid, conf_fname);
+      goto file_done;
+    }
+
+  if (fstat (fd, &s) < 0)
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] failed to stat `%s'", vcm->my_pid, conf_fname);
+      goto file_done;
+    }
+
+  if (!(S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] not a regular file `%s'", vcm->my_pid,
+		      conf_fname);
+      goto file_done;
+    }
+
+  unformat_init_unix_file (input, fd);
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      unformat_user (input, unformat_line_input, line_input);
+      unformat_skip_white_space (line_input);
+
+      if (unformat (line_input, "vppcom {"))
+	{
+	  vc_cfg_input = 1;
+	  continue;
+	}
+
+      if (vc_cfg_input)
+	{
+	  if (unformat (line_input, "heapsize %s", &chroot_path))
+	    {
+	      vec_terminate_c_string (chroot_path);
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured heapsize %s, "
+			      "actual heapsize %lld (0x%llx)",
+			      vcm->my_pid, chroot_path, vcl_cfg->heapsize,
+			      vcl_cfg->heapsize);
+	      vec_free (chroot_path);
+	    }
+	  else if (unformat (line_input, "api-prefix %s", &chroot_path))
+	    {
+	      vec_terminate_c_string (chroot_path);
+	      vl_set_memory_root_path ((char *) chroot_path);
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured api-prefix %s",
+			      vcm->my_pid, chroot_path);
+	      chroot_path = 0;	/* Don't vec_free() it! */
+	    }
+	  else if (unformat (line_input, "uid %d", &uid))
+	    {
+	      vl_set_memory_uid (uid);
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured uid %d", vcm->my_pid, uid);
+	    }
+	  else if (unformat (line_input, "gid %d", &gid))
+	    {
+	      vl_set_memory_gid (gid);
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured gid %d", vcm->my_pid, gid);
+	    }
+	  else if (unformat (line_input, "segment-baseva 0x%llx",
+			     &vcl_cfg->segment_baseva))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured segment_baseva 0x%llx",
+			      vcm->my_pid, vcl_cfg->segment_baseva);
+	    }
+	  else if (unformat (line_input, "segment-size 0x%lx",
+			     &vcl_cfg->segment_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured segment_size 0x%lx (%ld)",
+			      vcm->my_pid, vcl_cfg->segment_size,
+			      vcl_cfg->segment_size);
+	    }
+	  else if (unformat (line_input, "segment-size %ld",
+			     &vcl_cfg->segment_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured segment_size %ld (0x%lx)",
+			      vcm->my_pid, vcl_cfg->segment_size,
+			      vcl_cfg->segment_size);
+	    }
+	  else if (unformat (line_input, "add-segment-size 0x%lx",
+			     &vcl_cfg->add_segment_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning
+		  ("[%d] configured add_segment_size 0x%lx (%ld)",
+		   vcm->my_pid, vcl_cfg->add_segment_size,
+		   vcl_cfg->add_segment_size);
+	    }
+	  else if (unformat (line_input, "add-segment-size %ld",
+			     &vcl_cfg->add_segment_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning
+		  ("[%d] configured add_segment_size %ld (0x%lx)",
+		   vcm->my_pid, vcl_cfg->add_segment_size,
+		   vcl_cfg->add_segment_size);
+	    }
+	  else if (unformat (line_input, "preallocated-fifo-pairs %d",
+			     &vcl_cfg->preallocated_fifo_pairs))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured preallocated_fifo_pairs "
+			      "%d (0x%x)", vcm->my_pid,
+			      vcl_cfg->preallocated_fifo_pairs,
+			      vcl_cfg->preallocated_fifo_pairs);
+	    }
+	  else if (unformat (line_input, "rx-fifo-size 0x%lx",
+			     &vcl_cfg->rx_fifo_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured rx_fifo_size 0x%lx (%ld)",
+			      vcm->my_pid, vcl_cfg->rx_fifo_size,
+			      vcl_cfg->rx_fifo_size);
+	    }
+	  else if (unformat (line_input, "rx-fifo-size %ld",
+			     &vcl_cfg->rx_fifo_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured rx_fifo_size %ld (0x%lx)",
+			      vcm->my_pid, vcl_cfg->rx_fifo_size,
+			      vcl_cfg->rx_fifo_size);
+	    }
+	  else if (unformat (line_input, "tx-fifo-size 0x%lx",
+			     &vcl_cfg->tx_fifo_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured tx_fifo_size 0x%lx (%ld)",
+			      vcm->my_pid, vcl_cfg->tx_fifo_size,
+			      vcl_cfg->tx_fifo_size);
+	    }
+	  else if (unformat (line_input, "tx-fifo-size %ld",
+			     &vcl_cfg->tx_fifo_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured tx_fifo_size %ld (0x%lx)",
+			      vcm->my_pid, vcl_cfg->tx_fifo_size,
+			      vcl_cfg->tx_fifo_size);
+	    }
+	  else if (unformat (line_input, "event-queue-size 0x%lx",
+			     &vcl_cfg->event_queue_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured event_queue_size 0x%lx (%ld)",
+			      vcm->my_pid, vcl_cfg->event_queue_size,
+			      vcl_cfg->event_queue_size);
+	    }
+	  else if (unformat (line_input, "event-queue-size %ld",
+			     &vcl_cfg->event_queue_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured event_queue_size %ld (0x%lx)",
+			      vcm->my_pid, vcl_cfg->event_queue_size,
+			      vcl_cfg->event_queue_size);
+	    }
+	  else if (unformat (line_input, "listen-queue-size 0x%lx",
+			     &vcl_cfg->listen_queue_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured listen_queue_size 0x%lx (%ld)",
+			      vcm->my_pid, vcl_cfg->listen_queue_size,
+			      vcl_cfg->listen_queue_size);
+	    }
+	  else if (unformat (line_input, "listen-queue-size %ld",
+			     &vcl_cfg->listen_queue_size))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured listen_queue_size %ld (0x%lx)",
+			      vcm->my_pid, vcl_cfg->listen_queue_size,
+			      vcl_cfg->listen_queue_size);
+	    }
+	  else if (unformat (line_input, "app-timeout %f",
+			     &vcl_cfg->app_timeout))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured app_timeout %f",
+			      vcm->my_pid, vcl_cfg->app_timeout);
+	    }
+	  else if (unformat (line_input, "session-timeout %f",
+			     &vcl_cfg->session_timeout))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured session_timeout %f",
+			      vcm->my_pid, vcl_cfg->session_timeout);
+	    }
+	  else if (unformat (line_input, "accept-timeout %f",
+			     &vcl_cfg->accept_timeout))
+	    {
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] configured accept_timeout %f",
+			      vcm->my_pid, vcl_cfg->accept_timeout);
+	    }
+	  else if (unformat (line_input, "}"))
+	    {
+	      vc_cfg_input = 0;
+	      if (VPPCOM_DEBUG > 0)
+		clib_warning ("[%d] completed parsing vppcom config!",
+			      vcm->my_pid);
+	      goto input_done;
+	    }
+	  else
+	    {
+	      if (line_input->buffer[line_input->index] != '#')
+		{
+		  clib_warning ("[%d] Unknown vppcom config option: '%s'",
+				vcm->my_pid, (char *)
+				&line_input->buffer[line_input->index]);
+		}
+	    }
+	}
+    }
+
+input_done:
+  unformat_free (input);
+
+file_done:
+  if (fd > 0)
+    close (fd);
+}
+
+/*
+ * VPPCOM Public API functions
+ */
+int
+vppcom_app_create (char *app_name)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  vppcom_cfg_t *vcl_cfg = &vcm->cfg;
+  u8 *heap;
+  mheap_t *h;
+  int rv;
+
+  if (!vcm->init)
+    {
+      char *conf_fname;
+
+      vcm->init = 1;
+      vcm->my_pid = getpid ();
+      clib_fifo_validate (vcm->client_session_index_fifo,
+			  vcm->cfg.listen_queue_size);
+      vppcom_cfg_init (vcl_cfg);
+      conf_fname = getenv (VPPCOM_CONF_ENV);
+      if (!conf_fname)
+	{
+	  conf_fname = VPPCOM_CONF_DEFAULT;
+	  if (VPPCOM_DEBUG > 0)
+	    clib_warning ("[%d] getenv '%s' failed!", vcm->my_pid,
+			  VPPCOM_CONF_ENV);
+	}
+      vppcom_cfg_heapsize (conf_fname);
+      vppcom_cfg_read (conf_fname);
+      vcm->bind_session_index = ~0;
+      vcm->main_cpu = os_get_thread_index ();
+      heap = clib_mem_get_per_cpu_heap ();
+      h = mheap_header (heap);
+
+      /* make the main heap thread-safe */
+      h->flags |= MHEAP_FLAG_THREAD_SAFE;
+
+      vcm->session_index_by_vpp_handles = hash_create (0, sizeof (uword));
+
+      clib_time_init (&vcm->clib_time);
+      vppcom_init_error_string_table ();
+      svm_fifo_segment_init (vcl_cfg->segment_baseva,
+			     20 /* timeout in secs */ );
+      clib_spinlock_init (&vcm->sessions_lockp);
+      vppcom_api_hookup ();
+    }
+
+  if (vcm->my_client_index == ~0)
+    {
+      vcm->app_state = STATE_APP_START;
+      rv = vppcom_connect_to_vpp (app_name);
+      if (rv)
+	{
+	  clib_warning ("[%s] couldn't connect to VPP.", vcm->my_pid);
+	  return rv;
+	}
+
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] sending session enable", vcm->my_pid);
+
+      rv = vppcom_app_session_enable ();
+      if (rv)
+	{
+	  clib_warning ("[%d] vppcom_app_session_enable() failed!",
+			vcm->my_pid);
+	  return rv;
+	}
+
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] sending app attach", vcm->my_pid);
+
+      rv = vppcom_app_attach ();
+      if (rv)
+	{
+	  clib_warning ("[%d] vppcom_app_attach() failed!", vcm->my_pid);
+	  return rv;
+	}
+    }
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] app_name '%s', my_client_index %d (0x%x)",
+		  vcm->my_pid, app_name, vcm->my_client_index,
+		  vcm->my_client_index);
+
+  return VPPCOM_OK;
+}
+
+void
+vppcom_app_destroy (void)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  int rv;
+
+  if (vcm->my_client_index == ~0)
+    return;
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] detaching from VPP, my_client_index %d (0x%x)",
+		  vcm->my_pid, vcm->my_client_index, vcm->my_client_index);
+
+  vppcom_app_detach ();
+  rv = vppcom_wait_for_app_state_change (STATE_APP_ENABLED);
+  if (PREDICT_FALSE (rv))
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] application detach timed out, rv = %s (%d)",
+		      vcm->my_pid, vppcom_retval_str (rv), rv);
+    }
+  vl_client_disconnect_from_vlib ();
+  vcm->my_client_index = ~0;
+  vcm->app_state = STATE_APP_START;
+}
+
+int
+vppcom_session_create (u32 vrf, u8 proto, u8 is_nonblocking)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session;
+  u32 session_index;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  pool_get (vcm->sessions, session);
+  session_index = session - vcm->sessions;
+
+  session->vrf = vrf;
+  session->proto = proto;
+  session->state = STATE_START;
+  session->is_nonblocking = is_nonblocking;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] sid %d", vcm->my_pid, session_index);
+
+  return (int) session_index;
+}
+
+int
+vppcom_session_close (uint32_t session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  int rv;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] sid %d", vcm->my_pid, session_index);
+
+  if (session->is_cut_thru)
+    {
+      if (session->is_server)
+	rv = vppcom_session_unbind_cut_thru (session);
+    }
+  else
+    {
+      rv = (session->is_server) ?
+	vppcom_session_unbind (session_index) :
+	vppcom_session_disconnect (session_index);
+    }
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  pool_put_index (vcm->sessions, session_index);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  return rv;
+}
+
+int
+vppcom_session_bind (uint32_t session_index, vppcom_endpt_t * ep)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  int rv;
+
+  if (!ep || !ep->ip)
+    return VPPCOM_EINVAL;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] sid %d", vcm->my_pid, session_index);
+
+  session->vrf = ep->vrf;
+  session->is_ip4 = ep->is_ip4;
+  memset (session->ip, 0, sizeof (*session->ip));
+  clib_memcpy (session->ip, ep->ip, (ep->is_ip4 ?
+				     sizeof (ip4_address_t) :
+				     sizeof (ip6_address_t)));
+  session->port = ep->port;
+
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  return VPPCOM_OK;
+}
+
+int
+vppcom_session_listen (uint32_t session_index, uint32_t q_len)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  int rv;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] sid %d", vcm->my_pid, session_index);
+
+  ASSERT (vcm->bind_session_index == ~0);
+  vcm->bind_session_index = session_index;
+  vppcom_send_bind_sock (session);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  rv = vppcom_wait_for_session_state_change (session_index, STATE_LISTEN,
+					     vcm->cfg.session_timeout);
+  if (PREDICT_FALSE (rv))
+    {
+      vcm->bind_session_index = ~0;
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] server listen timed out, rv = %d (%d)",
+		      vcm->my_pid, vppcom_retval_str (rv), rv);
+      return rv;
+    }
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+  session->is_listen = 1;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  clib_fifo_validate (vcm->client_session_index_fifo, q_len);
+
+  return VPPCOM_OK;
+}
+
+int
+vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
+		       double wait_for_time)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  u32 client_session_index;
+  int rv;
+  f64 wait_for;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (listen_session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, listen_session_index);
+      return rv;
+    }
+
+  if (session->state != STATE_LISTEN)
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] session not in listen state, state = %s",
+		      vcm->my_pid, vppcom_session_state_str (session->state));
+      return VPPCOM_EBADFD;
+    }
+  wait_for = session->is_nonblocking ? 0 :
+    (wait_for_time < 0) ? vcm->cfg.accept_timeout : wait_for_time;
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] sid %d, state %s (%d)", vcm->my_pid,
+		  listen_session_index,
+		  vppcom_session_state_str (session->state), session->state);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  while (1)
+    {
+      rv = vppcom_wait_for_client_session_index (wait_for);
+      if (rv)
+	{
+	  if ((VPPCOM_DEBUG > 0))
+	    clib_warning ("[%d] sid %d, accept timed out, rv = %s (%d)",
+			  vcm->my_pid, listen_session_index,
+			  vppcom_retval_str (rv), rv);
+	  if ((wait_for == 0) || (wait_for_time > 0))
+	    return rv;
+	}
+      else
+	break;
+    }
+
+  clib_fifo_sub1 (vcm->client_session_index_fifo, client_session_index);
+
+  session = 0;
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (client_session_index, &session);
+  ASSERT (rv == VPPCOM_OK);
+  ASSERT (session->is_server);
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] Got a request: client sid %d", vcm->my_pid,
+		  client_session_index);
+
+  ep->vrf = session->vrf;
+  ep->is_cut_thru = session->is_cut_thru;
+  ep->is_ip4 = session->is_ip4;
+  ep->port = session->port;
+  memset (ep->ip, 0, sizeof (ip6_address_t));
+  clib_memcpy (ep->ip, session->ip, (session->is_ip4 ?
+				     sizeof (ip4_address_t) :
+				     sizeof (ip6_address_t)));
+  session->state = STATE_LISTEN;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  return (int) client_session_index;
+}
+
+int
+vppcom_session_connect (uint32_t session_index, vppcom_endpt_t * server_ep)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  int rv;
+  ip46_address_t *ip46;
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+
+  if (session->state == STATE_CONNECT)
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] session, sid (%d) already connected!",
+		      vcm->my_pid, session_index);
+      return VPPCOM_OK;
+    }
+
+  session->vrf = server_ep->vrf;
+  session->is_ip4 = server_ep->is_ip4;
+  ip46 = (ip46_address_t *) session->ip;
+  *ip46 = to_ip46 (!server_ep->is_ip4, server_ep->ip);
+  session->port = server_ep->port;
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      u8 *ip_str = format (0, "%U", format_ip46_address,
+			   &session->ip, session->is_ip4);
+      clib_warning ("[%d] connect sid %d to %s server port %d",
+		    vcm->my_pid, session_index, ip_str,
+		    clib_net_to_host_u16 (session->port));
+      vec_free (ip_str);
+    }
+
+  vppcom_send_connect_sock (session, session_index);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  rv = vppcom_wait_for_session_state_change (session_index, STATE_CONNECT,
+					     vcm->cfg.session_timeout);
+  if (PREDICT_FALSE (rv))
+    {
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] connect timed out, rv = %s (%d)",
+		      vcm->my_pid, vppcom_retval_str (rv), rv);
+      return rv;
+    }
+  return VPPCOM_OK;
+}
+
+int
+vppcom_session_read (uint32_t session_index, void *buf, int n)
+{
+  session_fifo_event_t _e, *e = &_e;
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  svm_fifo_t *rx_fifo;
+  int n_read = 0;
+  int rv;
+  char *fifo_str;
+
+  ASSERT (buf);
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+
+  if (session->is_cut_thru)
+    {
+      rx_fifo = session->is_server ? session->server_rx_fifo :
+	session->server_tx_fifo;
+      fifo_str = session->is_server ? "server_rx_fifo" : "server_tx_fifo";
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+
+      n_read = svm_fifo_dequeue_nowait (rx_fifo, n, buf);
+
+      if (n_read <= 0)
+	return VPPCOM_EAGAIN;
+
+    }
+  else
+    {
+      rv = unix_shared_memory_queue_sub (session->event_queue, (u8 *) e,
+					 1 /* nowait */ );
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (rv < 0)
+	return VPPCOM_EAGAIN;
+
+      switch (e->event_type)
+	{
+	case FIFO_EVENT_APP_RX:
+	  rx_fifo = e->fifo;
+	  fifo_str = "app_rx_fifo";
+	  n_read = svm_fifo_dequeue_nowait (rx_fifo, n, buf);
+	  break;
+
+	case FIFO_EVENT_DISCONNECT:
+	  return VPPCOM_ECONNRESET;
+
+	default:
+	  if (VPPCOM_DEBUG > 0)
+	    clib_warning ("[%d] unknown event type %d", vcm->my_pid,
+			  e->event_type);
+	  return VPPCOM_EAGAIN;
+	}
+    }
+
+  if (VPPCOM_DEBUG > 2)
+    clib_warning ("[%d] sid %d, read %d bytes from %s (%p)", vcm->my_pid,
+		  session_index, n_read, fifo_str, rx_fifo);
+  return n_read;
+}
+
+static inline int
+vppcom_session_read_ready (session_t * session, u32 session_index)
+{
+  session_fifo_event_t _e, *e = &_e;
+  vppcom_main_t *vcm = &vppcom_main;
+  svm_fifo_t *rx_fifo;
+  int rv;
+  int ready = 0;
+
+  /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
+  if (session->is_cut_thru)
+    {
+      rx_fifo = session->is_server ? session->server_rx_fifo :
+	session->server_tx_fifo;
+
+      ready = svm_fifo_max_dequeue (rx_fifo);
+    }
+  else if (session->is_listen)
+    ready = clib_fifo_elts (vcm->client_session_index_fifo);
+  else
+    {
+      rv = unix_shared_memory_queue_sub (vcm->app_event_queue, (u8 *) e,
+					 1 /* nowait */ );
+      if (rv >= 0)
+	{
+	  switch (e->event_type)
+	    {
+	    case FIFO_EVENT_APP_RX:
+	      rx_fifo = e->fifo;
+	      ready = svm_fifo_max_dequeue (rx_fifo);
+	      break;
+
+	    case FIFO_EVENT_DISCONNECT:
+	      return VPPCOM_ECONNRESET;
+
+	    default:
+	      clib_warning ("[%d] unknown event type %d", vcm->my_pid,
+			    e->event_type);
+	    }
+	}
+    }
+
+  if (VPPCOM_DEBUG > 2)
+    clib_warning ("[%d] sid %d, peek %s (%p), ready = %d", vcm->my_pid,
+		  session_index,
+		  session->is_server ? "server_rx_fifo" : "server_tx_fifo",
+		  rx_fifo, ready);
+
+  return ready;
+}
+
+int
+vppcom_session_write (uint32_t session_index, void *buf, int n)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  session_t *session = 0;
+  svm_fifo_t *tx_fifo;
+  unix_shared_memory_queue_t *q;
+  session_fifo_event_t evt;
+  int rv;
+  char *fifo_str;
+  u8 is_nonblocking;
+
+  ASSERT (buf);
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
+  rv = vppcom_session_at_index (session_index, &session);
+  if (PREDICT_FALSE (rv))
+    {
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 0)
+	clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+		      vcm->my_pid, session_index);
+      return rv;
+    }
+
+  tx_fifo = ((!session->is_cut_thru || session->is_server) ?
+	     session->server_tx_fifo : session->server_rx_fifo);
+  fifo_str = ((!session->is_cut_thru || session->is_server) ?
+	      "server_tx_fifo" : "server_rx_fifo");
+  is_nonblocking = session->is_nonblocking;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  do
+    {
+      rv = svm_fifo_enqueue_nowait (tx_fifo, n, buf);
+    }
+  while (!is_nonblocking && (rv <= 0));
+
+  /* If event wasn't set, add one */
+  if ((rv > 0) && svm_fifo_set_event (tx_fifo))
+    {
+      int rval;
+
+      /* Fabricate TX event, send to vpp */
+      evt.fifo = tx_fifo;
+      evt.event_type = FIFO_EVENT_APP_TX;
+      evt.event_id = vcm->tx_event_id++;
+
+      clib_spinlock_lock (&vcm->sessions_lockp);
+      rval = vppcom_session_at_index (session_index, &session);
+      if (PREDICT_FALSE (rval))
+	{
+	  clib_spinlock_unlock (&vcm->sessions_lockp);
+	  if (VPPCOM_DEBUG > 1)
+	    clib_warning ("[%d] invalid session, sid (%d) has been closed!",
+			  vcm->my_pid, session_index);
+	  return rval;
+	}
+      q = session->event_queue;
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      ASSERT (q);
+      unix_shared_memory_queue_add (q, (u8 *) & evt,
+				    0 /* do wait for mutex */ );
+    }
+
+  if (VPPCOM_DEBUG > 2)
+    clib_warning ("[%d] sid %d, wrote %d bytes to %s (%p)", vcm->my_pid,
+		  session_index, rv, fifo_str, tx_fifo);
+
+  return rv;
+}
+
+static inline int
+vppcom_session_write_ready (session_t * session, u32 session_index)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  svm_fifo_t *tx_fifo;
+  int rv;
+
+  /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
+  tx_fifo = ((!session->is_cut_thru || session->is_server) ?
+	     session->server_tx_fifo : session->server_rx_fifo);
+
+  rv = svm_fifo_max_enqueue (tx_fifo);
+
+  if (VPPCOM_DEBUG > 2)
+    clib_warning ("[%d] sid %d, peek %s (%p), ready = %d", vcm->my_pid,
+		  session_index,
+		  session->is_server ? "server_tx_fifo" : "server_rx_fifo",
+		  tx_fifo, rv);
+  return rv;
+}
+
+int
+vppcom_select (unsigned long n_bits, unsigned long *read_map,
+	       unsigned long *write_map, unsigned long *except_map,
+	       double time_to_wait)
+{
+  vppcom_main_t *vcm = &vppcom_main;
+  u32 session_index;
+  session_t *session = 0;
+  int rv, bits_set = 0;
+  f64 timeout = clib_time_now (&vcm->clib_time) + time_to_wait;
+  u32 minbits = clib_max (n_bits, BITS (uword));
+
+  ASSERT (sizeof (clib_bitmap_t) == sizeof (long int));
+
+  if (read_map)
+    {
+      clib_bitmap_validate (vcm->rd_bitmap, minbits);
+      clib_memcpy (vcm->rd_bitmap, read_map, vec_len (vcm->rd_bitmap));
+      memset (read_map, 0, vec_len (vcm->rd_bitmap));
+    }
+  if (write_map)
+    {
+      clib_bitmap_validate (vcm->wr_bitmap, minbits);
+      clib_memcpy (vcm->wr_bitmap, write_map, vec_len (vcm->wr_bitmap));
+      memset (write_map, 0, vec_len (vcm->wr_bitmap));
+    }
+  if (except_map)
+    {
+      clib_bitmap_validate (vcm->ex_bitmap, minbits);
+      clib_memcpy (vcm->ex_bitmap, except_map, vec_len (vcm->ex_bitmap));
+      memset (except_map, 0, vec_len (vcm->ex_bitmap));
+    }
+
+  do
+    {
+      /* *INDENT-OFF* */
+      clib_bitmap_foreach (session_index, vcm->rd_bitmap,
+        ({
+          clib_spinlock_lock (&vcm->sessions_lockp);
+          rv = vppcom_session_at_index (session_index, &session);
+          if (rv < 0)
+            {
+              clib_spinlock_unlock (&vcm->sessions_lockp);
+              if (VPPCOM_DEBUG > 1)
+                clib_warning ("[%d] session %d specified in "
+                              "read_map is closed.", vcm->my_pid,
+                              session_index);
+              bits_set = VPPCOM_EBADFD;
+              goto select_done;
+            }
+
+          rv = vppcom_session_read_ready (session, session_index);
+          clib_spinlock_unlock (&vcm->sessions_lockp);
+          if (vcm->ex_bitmap &&
+              clib_bitmap_get (vcm->ex_bitmap, session_index) && (rv < 0))
+            {
+              // TBD: clib_warning
+              clib_bitmap_set_no_check (except_map, session_index, 1);
+              bits_set++;
+            }
+          else if (rv > 0)
+            {
+              // TBD: clib_warning
+              clib_bitmap_set_no_check (read_map, session_index, 1);
+              bits_set++;
+            }
+        }));
+
+      clib_bitmap_foreach (session_index, vcm->wr_bitmap,
+        ({
+          clib_spinlock_lock (&vcm->sessions_lockp);
+          rv = vppcom_session_at_index (session_index, &session);
+          if (rv < 0)
+            {
+              clib_spinlock_unlock (&vcm->sessions_lockp);
+              if (VPPCOM_DEBUG > 0)
+                clib_warning ("[%d] session %d specified in "
+                              "write_map is closed.", vcm->my_pid,
+                              session_index);
+              bits_set = VPPCOM_EBADFD;
+              goto select_done;
+            }
+
+          rv = vppcom_session_write_ready (session, session_index);
+          clib_spinlock_unlock (&vcm->sessions_lockp);
+          if (rv > 0)
+            {
+              // TBD: clib_warning
+              clib_bitmap_set_no_check (write_map, session_index, 1);
+              bits_set++;
+            }
+        }));
+
+      clib_bitmap_foreach (session_index, vcm->ex_bitmap,
+        ({
+          clib_spinlock_lock (&vcm->sessions_lockp);
+          rv = vppcom_session_at_index (session_index, &session);
+          if (rv < 0)
+            {
+              clib_spinlock_unlock (&vcm->sessions_lockp);
+              if (VPPCOM_DEBUG > 1)
+                clib_warning ("[%d] session %d specified in "
+                              "except_map is closed.", vcm->my_pid,
+                              session_index);
+              bits_set = VPPCOM_EBADFD;
+              goto select_done;
+            }
+
+          rv = vppcom_session_read_ready (session, session_index);
+          clib_spinlock_unlock (&vcm->sessions_lockp);
+          if (rv < 0)
+            {
+              // TBD: clib_warning
+              clib_bitmap_set_no_check (except_map, session_index, 1);
+              bits_set++;
+            }
+        }));
+      /* *INDENT-ON* */
+    }
+  while (clib_time_now (&vcm->clib_time) < timeout);
+
+select_done:
+  return (bits_set);
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */