VCL/LD_PRELOAD: Fix unfiltered debug output.
[vpp.git] / src / vcl / vppcom.c
index 75e86c8..aa149b7 100644 (file)
@@ -23,6 +23,7 @@
 #include <vcl/vppcom.h>
 #include <vlib/unix/unix.h>
 #include <vppinfra/vec_bootstrap.h>
+#include <vppinfra/elog.h>
 
 #define vl_typedefs            /* define message structures */
 #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
+/* Set VPPCOM_DEBUG_INIT 2 for connection debug,
+ *                       3 for read/write debug output
+ * or
+ *    export VCL_DEBUG=<#> to set dynamically.
+ */
+#define VPPCOM_DEBUG_INIT 1
 #else
-#define VPPCOM_DEBUG 0
+#define VPPCOM_DEBUG_INIT 0
 #endif
 
+#define VPPCOM_DEBUG vcm->debug
+
 /*
  * VPPCOM Private definitions and functions.
  */
@@ -60,14 +67,18 @@ typedef enum
 
 typedef enum
 {
-  STATE_START,
-  STATE_CONNECT,
-  STATE_LISTEN,
-  STATE_ACCEPT,
-  STATE_DISCONNECT,
-  STATE_FAILED
+  STATE_START = 0x01,
+  STATE_CONNECT = 0x02,
+  STATE_LISTEN = 0x04,
+  STATE_ACCEPT = 0x08,
+  STATE_CLOSE_ON_EMPTY = 0x10,
+  STATE_DISCONNECT = 0x20,
+  STATE_FAILED = 0x40
 } session_state_t;
 
+#define SERVER_STATE_OPEN  (STATE_ACCEPT|STATE_CLOSE_ON_EMPTY)
+#define CLIENT_STATE_OPEN  (STATE_CONNECT|STATE_CLOSE_ON_EMPTY)
+
 typedef struct epoll_event vppcom_epoll_event_t;
 
 typedef struct
@@ -77,6 +88,7 @@ typedef struct
   u32 vep_idx;
   vppcom_epoll_event_t ev;
 #define VEP_DEFAULT_ET_MASK  (EPOLLIN|EPOLLOUT)
+#define VEP_UNSUPPORTED_EVENTS (EPOLLONESHOT|EPOLLEXCLUSIVE)
   u32 et_mask;
 } vppcom_epoll_t;
 
@@ -86,26 +98,65 @@ typedef struct
   ip46_address_t ip46;
 } vppcom_ip46_t;
 
+enum
+{
+  VCL_SESS_ATTR_SERVER,
+  VCL_SESS_ATTR_CUT_THRU,
+  VCL_SESS_ATTR_VEP,
+  VCL_SESS_ATTR_VEP_SESSION,
+  VCL_SESS_ATTR_LISTEN,                // SOL_SOCKET,SO_ACCEPTCONN
+  VCL_SESS_ATTR_NONBLOCK,      // fcntl,O_NONBLOCK
+  VCL_SESS_ATTR_REUSEADDR,     // SOL_SOCKET,SO_REUSEADDR
+  VCL_SESS_ATTR_REUSEPORT,     // SOL_SOCKET,SO_REUSEPORT
+  VCL_SESS_ATTR_BROADCAST,     // SOL_SOCKET,SO_BROADCAST
+  VCL_SESS_ATTR_V6ONLY,                // SOL_TCP,IPV6_V6ONLY
+  VCL_SESS_ATTR_KEEPALIVE,     // SOL_SOCKET,SO_KEEPALIVE
+  VCL_SESS_ATTR_TCP_NODELAY,   // SOL_TCP,TCP_NODELAY
+  VCL_SESS_ATTR_TCP_KEEPIDLE,  // SOL_TCP,TCP_KEEPIDLE
+  VCL_SESS_ATTR_TCP_KEEPINTVL, // SOL_TCP,TCP_KEEPINTVL
+  VCL_SESS_ATTR_MAX
+} vppcom_session_attr_t;
+
+#define VCL_SESS_ATTR_SET(ATTR, VAL)            \
+do {                                            \
+  (ATTR) |= 1 << (VAL);                         \
+ } while (0)
+
+#define VCL_SESS_ATTR_CLR(ATTR, VAL)            \
+do {                                            \
+  (ATTR) &= ~(1 << (VAL));                      \
+ } while (0)
+
+#define VCL_SESS_ATTR_TEST(ATTR, VAL)           \
+  ((ATTR) & (1 << (VAL)) ? 1 : 0)
+
 typedef struct
 {
   volatile session_state_t state;
 
   svm_fifo_t *server_rx_fifo;
   svm_fifo_t *server_tx_fifo;
+  u32 sndbuf_size;             // VPP-TBD: Hack until support setsockopt(SO_SNDBUF)
+  u32 rcvbuf_size;             // VPP-TBD: Hack until support setsockopt(SO_RCVBUF)
+  u32 user_mss;                        // VPP-TBD: Hack until support setsockopt(TCP_MAXSEG)
+  u8 *segment_name;
   u32 sm_seg_index;
-  u64 vpp_session_handle;
-  unix_shared_memory_queue_t *vpp_event_queue;
+  u32 client_context;
+  u64 vpp_handle;
+  svm_queue_t *vpp_event_queue;
 
   /* Socket configuration state */
-  /* TBD: covert 'is_*' vars to bit in u8 flags; */
+  /* TBD: covert 'is_*' vars to bit in session->attr; */
   u8 is_server;
   u8 is_listen;
   u8 is_cut_thru;
   u8 is_nonblocking;
   u8 is_vep;
   u8 is_vep_session;
+  u32 attr;
   u32 wait_cont_idx;
   vppcom_epoll_t vep;
+  int libc_epfd;
   u32 vrf;
   vppcom_ip46_t lcl_addr;
   vppcom_ip46_t peer_addr;
@@ -114,11 +165,13 @@ typedef struct
   u8 proto;
   u64 client_queue_address;
   u64 options[16];
+  elog_track_t elog_track;
 } session_t;
 
 typedef struct vppcom_cfg_t_
 {
   u64 heapsize;
+  u32 vpp_api_q_length;
   u64 segment_baseva;
   u32 segment_size;
   u32 add_segment_size;
@@ -127,24 +180,28 @@ typedef struct vppcom_cfg_t_
   u32 tx_fifo_size;
   u32 event_queue_size;
   u32 listen_queue_size;
-  u8 session_scope_local;
-  u8 session_scope_global;
+  u8 app_proxy_transport_tcp;
+  u8 app_proxy_transport_udp;
+  u8 app_scope_local;
+  u8 app_scope_global;
   u8 *namespace_id;
   u64 namespace_secret;
   f64 app_timeout;
   f64 session_timeout;
   f64 accept_timeout;
+  u32 event_ring_size;
+  char *event_log_path;
 } vppcom_cfg_t;
 
 typedef struct vppcom_main_t_
 {
   u8 init;
+  u32 debug;
   u32 *client_session_index_fifo;
-  volatile u32 bind_session_index;
   int main_cpu;
 
   /* vpe input queue */
-  unix_shared_memory_queue_t *vl_input_queue;
+  svm_queue_t *vl_input_queue;
 
   /* API client handle */
   u32 my_client_index;
@@ -162,13 +219,11 @@ typedef struct vppcom_main_t_
   clib_bitmap_t *ex_bitmap;
 
   /* Our event queue */
-  unix_shared_memory_queue_t *app_event_queue;
+  svm_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;
 
@@ -177,11 +232,37 @@ typedef struct vppcom_main_t_
 
   vppcom_cfg_t cfg;
 
+  /* Event logging */
+  elog_main_t elog_main;
+  elog_track_t elog_track;
+
   /* 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 };
+/* NOTE: _vppcom_main is only used until the heap is allocated.
+ *       Do not access it directly -- use vcm which will point to
+ *       the heap allocated copy after init.
+ */
+static vppcom_main_t _vppcom_main = {
+  .debug = VPPCOM_DEBUG_INIT,
+  .my_client_index = ~0
+};
+
+static vppcom_main_t *vcm = &_vppcom_main;
+
+#define VCL_LOCK_AND_GET_SESSION(I, S)                          \
+do {                                                            \
+  clib_spinlock_lock (&vcm->sessions_lockp);                    \
+  rv = vppcom_session_at_index (I, S);                          \
+  if (PREDICT_FALSE (rv))                                       \
+    {                                                           \
+      clib_spinlock_unlock (&vcm->sessions_lockp);              \
+      clib_warning ("VCL<%d>: ERROR: Invalid ##I (%u)!",        \
+                    getpid (), I);                              \
+      goto done;                                                \
+    }                                                           \
+} while (0)
 
 static const char *
 vppcom_app_state_str (app_state_t state)
@@ -237,6 +318,10 @@ vppcom_session_state_str (session_state_t state)
       st = "STATE_ACCEPT";
       break;
 
+    case STATE_CLOSE_ON_EMPTY:
+      st = "STATE_CLOSE_ON_EMPTY";
+      break;
+
     case STATE_DISCONNECT:
       st = "STATE_DISCONNECT";
       break;
@@ -259,48 +344,143 @@ vppcom_session_state_str (session_state_t state)
 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 (%u) has been closed!",
-                   vcm->my_pid, session_index);
+      clib_warning ("VCL<%d>: invalid session, sid (%u) has been closed!",
+                   getpid (), session_index);
       return VPPCOM_EBADFD;
     }
   *sess = pool_elt_at_index (vcm->sessions, session_index);
   return VPPCOM_OK;
 }
 
+static inline void
+vppcom_session_table_add_listener (u64 listener_handle, u32 value)
+{
+  /* Session and listener handles have different formats. The latter has
+   * the thread index in the upper 32 bits while the former has the session
+   * type. Knowing that, for listeners we just flip the MSB to 1 */
+  listener_handle |= 1ULL << 63;
+  hash_set (vcm->session_index_by_vpp_handles, listener_handle, value);
+}
+
+static inline session_t *
+vppcom_session_table_lookup_listener (u64 listener_handle)
+{
+  uword *p;
+  u64 handle = listener_handle | (1ULL << 63);
+  session_t *session;
+
+  p = hash_get (vcm->session_index_by_vpp_handles, handle);
+  if (!p)
+    {
+      clib_warning ("VCL<%d>: couldn't find listen session: unknown vpp "
+                   "listener handle %llx", getpid (), listener_handle);
+      return 0;
+    }
+  if (pool_is_free_index (vcm->sessions, p[0]))
+    {
+      if (VPPCOM_DEBUG > 1)
+       clib_warning ("VCL<%d>: invalid listen session, sid (%u)",
+                     getpid (), p[0]);
+      return 0;
+    }
+
+  session = pool_elt_at_index (vcm->sessions, p[0]);
+  ASSERT (session->is_listen);
+  return session;
+}
+
+static inline void
+vppcom_session_table_del_listener (u64 listener_handle)
+{
+  listener_handle |= 1ULL << 63;
+  hash_unset (vcm->session_index_by_vpp_handles, listener_handle);
+}
+
+static void
+write_elog (void)
+{
+  elog_main_t *em = &vcm->elog_main;
+  char *chroot_file;
+  clib_error_t *error = 0;
+
+  chroot_file =
+    (char *) format (0, "%s/%d-%d-vcl-elog%c", vcm->cfg.event_log_path,
+                    vcm->my_client_index, getpid (), 0);
+  error = elog_write_file (em, chroot_file, 1 /* flush ring */ );
+  if (error)
+    {
+      clib_error_report (error);
+    }
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("[%d] Event Log:'%s' ", getpid (), chroot_file);
+
+}
+
 static int
 vppcom_connect_to_vpp (char *app_name)
 {
   api_main_t *am = &api_main;
-  vppcom_main_t *vcm = &vppcom_main;
+  int rv = VPPCOM_OK;
 
   if (VPPCOM_DEBUG > 0)
-    printf ("\nConnecting to VPP api...");
-  if (vl_client_connect_to_vlib ("/vpe-api", app_name, 32) < 0)
+    clib_warning ("VCL<%d>: app (%s) connecting to VPP api...",
+                 getpid (), app_name);
+
+  if (vl_client_connect_to_vlib ("/vpe-api", app_name,
+                                vcm->cfg.vpp_api_q_length) < 0)
+    {
+      clib_warning ("VCL<%d>: app (%s) connect failed!", getpid (), app_name);
+      rv = VPPCOM_ECONNREFUSED;
+    }
+  else
     {
-      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;
+      vcm->app_state = STATE_APP_CONN_VPP;
+
+      if (VPPCOM_DEBUG > 0)
+       clib_warning ("VCL<%d>: app (%s) is connected to VPP!",
+                     getpid (), app_name);
     }
 
-  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->elog_main.lock =
+       clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES, CLIB_CACHE_LINE_BYTES);
+      vcm->elog_main.lock[0] = 0;
+      vcm->elog_main.event_ring_size = vcm->cfg.event_ring_size;
+      elog_init (&vcm->elog_main, vcm->elog_main.event_ring_size);
+      elog_enable_disable (&vcm->elog_main, 1);
+
+      vcm->elog_track.name =
+       (char *) format (0, "P:%d:C:%d%c", getpid (),
+                        vcm->my_client_index, 0);
+      elog_track_register (&vcm->elog_main, &vcm->elog_track);
 
-  vcm->app_state = STATE_APP_CONN_VPP;
-  return VPPCOM_OK;
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "connect_vpp:rv:%d",
+       .format_args = "i4",
+      };
+      struct
+      {
+       u32 data;
+      } *ed;
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, vcm->elog_track);
+      ed->data = rv;
+      /* *INDENT-ON* */
+    }
+  return rv;
 }
 
 static u8 *
 format_api_error (u8 * s, va_list * args)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   i32 error = va_arg (*args, u32);
   uword *p;
 
@@ -316,8 +496,6 @@ format_api_error (u8 * s, va_list * args)
 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);
@@ -330,7 +508,6 @@ vppcom_init_error_string_table (void)
 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)
@@ -339,8 +516,28 @@ vppcom_wait_for_app_state_change (app_state_t app_state)
        return VPPCOM_OK;
     }
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] timeout waiting for state %s (%d)", vcm->my_pid,
+    clib_warning ("VCL<%d>: timeout waiting for state %s (%d)", getpid (),
                  vppcom_app_state_str (app_state), app_state);
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+       {
+         .format = "ERR: timeout state:%d",
+         .format_args = "i4",
+       };
+      struct
+      {
+       u32 data;
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, vcm->elog_track);
+
+      ed->data = app_state;
+      /* *INDENT-ON* */
+    }
+
   return VPPCOM_ETIMEDOUT;
 }
 
@@ -349,7 +546,6 @@ 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;
@@ -368,20 +564,45 @@ vppcom_wait_for_session_state_change (u32 session_index,
          clib_spinlock_unlock (&vcm->sessions_lockp);
          return VPPCOM_OK;
        }
+      if (session->state == STATE_FAILED)
+       {
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+         return VPPCOM_ECONNREFUSED;
+       }
+
       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);
+    clib_warning ("VCL<%d>: timeout waiting for state 0x%x (%s)", getpid (),
+                 state, vppcom_session_state_str (state));
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+       {
+         .format = "ERR: timeout state:%d",
+         .format_args = "i4",
+       };
+      struct
+      {
+       u32 data;
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+      ed->data = state;
+      /* *INDENT-ON* */
+    }
+
   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
@@ -395,8 +616,28 @@ vppcom_wait_for_client_session_index (f64 wait_for_time)
     return VPPCOM_EAGAIN;
 
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] timeout waiting for client_session_index",
-                 vcm->my_pid);
+    clib_warning ("VCL<%d>: timeout waiting for client_session_index",
+                 getpid ());
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+       {
+         .format = "ERR: timeout waiting for session index :%d",
+         .format_args = "i4",
+       };
+      struct
+      {
+       u32 data;
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, vcm->elog_track);
+
+      ed->data = getpid();
+      /* *INDENT-ON* */
+    }
+
   return VPPCOM_ETIMEDOUT;
 }
 
@@ -406,7 +647,6 @@ vppcom_wait_for_client_session_index (f64 wait_for_time)
 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));
@@ -421,7 +661,6 @@ vppcom_send_session_enable_disable (u8 is_enable)
 static int
 vppcom_app_session_enable (void)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   int rv;
 
   if (vcm->app_state != STATE_APP_ENABLED)
@@ -431,8 +670,9 @@ vppcom_app_session_enable (void)
       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);
+           clib_warning ("VCL<%d>: application session enable timed out! "
+                         "returning %d (%s)",
+                         getpid (), rv, vppcom_retval_str (rv));
          return rv;
        }
     }
@@ -443,11 +683,9 @@ 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,
+      clib_warning ("VCL<%d>: session_enable_disable failed: %U", getpid (),
                    format_api_error, ntohl (mp->retval));
     }
   else
@@ -457,9 +695,10 @@ static void
 static void
 vppcom_app_send_attach (void)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   vl_api_application_attach_t *bmp;
   u8 nsid_len = vec_len (vcm->cfg.namespace_id);
+  u8 app_is_proxy = (vcm->cfg.app_proxy_transport_tcp ||
+                    vcm->cfg.app_proxy_transport_udp);
 
   bmp = vl_msg_api_alloc (sizeof (*bmp));
   memset (bmp, 0, sizeof (*bmp));
@@ -469,12 +708,19 @@ vppcom_app_send_attach (void)
   bmp->context = htonl (0xfeedface);
   bmp->options[APP_OPTIONS_FLAGS] =
     APP_OPTIONS_FLAGS_ACCEPT_REDIRECT | APP_OPTIONS_FLAGS_ADD_SEGMENT |
-    (vcm->cfg.session_scope_local ? APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE : 0) |
-    (vcm->cfg.session_scope_global ? APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE : 0);
-  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;
+    (vcm->cfg.app_scope_local ? APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE : 0) |
+    (vcm->cfg.app_scope_global ? APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE : 0) |
+    (app_is_proxy ? APP_OPTIONS_FLAGS_IS_PROXY : 0);
+  bmp->options[APP_OPTIONS_PROXY_TRANSPORT] =
+    (vcm->cfg.app_proxy_transport_tcp ? 1 << TRANSPORT_PROTO_TCP : 0) |
+    (vcm->cfg.app_proxy_transport_udp ? 1 << TRANSPORT_PROTO_UDP : 0);
+  bmp->options[APP_OPTIONS_SEGMENT_SIZE] = vcm->cfg.segment_size;
+  bmp->options[APP_OPTIONS_ADD_SEGMENT_SIZE] = vcm->cfg.add_segment_size;
+  bmp->options[APP_OPTIONS_RX_FIFO_SIZE] = vcm->cfg.rx_fifo_size;
+  bmp->options[APP_OPTIONS_TX_FIFO_SIZE] = vcm->cfg.tx_fifo_size;
+  bmp->options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] =
+    vcm->cfg.preallocated_fifo_pairs;
+  bmp->options[APP_OPTIONS_EVT_QUEUE_SIZE] = vcm->cfg.event_queue_size;
   if (nsid_len)
     {
       bmp->namespace_id_len = nsid_len;
@@ -487,7 +733,6 @@ vppcom_app_send_attach (void)
 static int
 vppcom_app_attach (void)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   int rv;
 
   vppcom_app_send_attach ();
@@ -495,8 +740,9 @@ vppcom_app_attach (void)
   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);
+       clib_warning ("VCL<%d>: application attach timed out! "
+                     "returning %d (%s)",
+                     getpid (), rv, vppcom_retval_str (rv));
       return rv;
     }
   return VPPCOM_OK;
@@ -505,7 +751,6 @@ vppcom_app_attach (void)
 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));
@@ -520,7 +765,6 @@ 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;
@@ -528,14 +772,14 @@ vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
   memset (a, 0, sizeof (*a));
   if (mp->retval)
     {
-      clib_warning ("[%d] attach failed: %U", vcm->my_pid,
+      clib_warning ("VCL<%d>: attach failed: %U", getpid (),
                    format_api_error, ntohl (mp->retval));
       return;
     }
 
   if (mp->segment_name_length == 0)
     {
-      clib_warning ("[%d] segment_name_length zero", vcm->my_pid);
+      clib_warning ("VCL<%d>: segment_name_length zero", getpid ());
       return;
     }
 
@@ -549,14 +793,13 @@ vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
   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);
+      clib_warning ("VCL<%d>: svm_fifo_segment_attach ('%s') failed",
+                   getpid (), mp->segment_name);
       return;
     }
 
   vcm->app_event_queue =
-    uword_to_pointer (mp->app_event_queue_address,
-                     unix_shared_memory_queue_t *);
+    uword_to_pointer (mp->app_event_queue_address, svm_queue_t *);
 
   vcm->app_state = STATE_APP_ATTACHED;
 }
@@ -565,10 +808,8 @@ 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,
+    clib_warning ("VCL<%d>: detach failed: %U", getpid (), format_api_error,
                  ntohl (mp->retval));
 
   vcm->app_state = STATE_APP_ENABLED;
@@ -578,42 +819,15 @@ 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 (%u) 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));
+    clib_warning ("VCL<%d>: vpp handle 0x%llx: disconnect session failed: %U",
+                 getpid (), mp->handle, 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;
@@ -626,61 +840,52 @@ vl_api_map_another_segment_t_handler (vl_api_map_another_segment_t * mp)
   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);
+      clib_warning ("VCL<%d>: svm_fifo_segment_attach ('%s') failed",
+                   getpid (), mp->segment_name);
       return;
     }
   if (VPPCOM_DEBUG > 1)
-    clib_warning ("[%d] mapped new segment '%s' size %d", vcm->my_pid,
+    clib_warning ("VCL<%d>: mapped new segment '%s' size %d", getpid (),
                  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 (%u) has been closed!",
-                         vcm->my_pid, p[0]);
-       }
-      else
-       pool_put (vcm->sessions, session);
+      int rv;
+      session_t *session = 0;
+      u32 session_index = p[0];
+
+      VCL_LOCK_AND_GET_SESSION (session_index, &session);
+      session->state = STATE_CLOSE_ON_EMPTY;
+
+      if (VPPCOM_DEBUG > 1)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "setting state to 0x%x (%s)",
+                     getpid (), mp->handle, session_index, session->state,
+                     vppcom_session_state_str (session->state));
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      hash_unset (vcm->session_index_by_vpp_handles, mp->handle);
+      return;
+
+    done:
+      if (VPPCOM_DEBUG > 1)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "session lookup failed!",
+                     getpid (), mp->handle, session_index);
     }
   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);
+    clib_warning ("VCL<%d>: vpp handle 0x%llx: session lookup by "
+                 "handle failed!", getpid (), mp->handle);
 }
 
 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;
@@ -694,20 +899,33 @@ vl_api_reset_session_t_handler (vl_api_reset_session_t * mp)
       rval = vppcom_session_at_index (p[0], &session);
       if (PREDICT_FALSE (rval))
        {
-         if (VPPCOM_DEBUG > 1)
-           clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                         vcm->my_pid, p[0]);
+         rv = VNET_API_ERROR_INVALID_VALUE_2;
+         clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                       "session lookup failed! returning %d %U",
+                       getpid (), mp->handle, p[0],
+                       rv, format_api_error, rv);
        }
       else
-       pool_put (vcm->sessions, session);
+       {
+         /* TBD: should this disconnect immediately and
+          * flush the fifos?
+          */
+         session->state = STATE_CLOSE_ON_EMPTY;
+
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                         "state set to %d (%s)!", getpid (),
+                         mp->handle, p[0], session->state,
+                         vppcom_session_state_str (session->state));
+       }
       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;
+      rv = VNET_API_ERROR_INVALID_VALUE;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx: session lookup "
+                   "failed! returning %d %U",
+                   getpid (), mp->handle, rv, format_api_error, rv);
     }
 
   rmp = vl_msg_api_alloc (sizeof (*rmp));
@@ -721,34 +939,37 @@ vl_api_reset_session_t_handler (vl_api_reset_session_t * mp)
 static void
 vl_api_connect_session_reply_t_handler (vl_api_connect_session_reply_t * mp)
 {
-  vppcom_main_t *vcm = &vppcom_main;
-  session_t *session;
+  session_t *session = 0;
   u32 session_index;
   svm_fifo_t *rx_fifo, *tx_fifo;
   u8 is_cut_thru = 0;
   int rv;
 
+  session_index = mp->context;
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+done:
   if (mp->retval)
     {
-      clib_warning ("[%d] connect failed: %U", vcm->my_pid, format_api_error,
-                   ntohl (mp->retval));
-      return;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "connect failed! %U",
+                   getpid (), mp->handle, session_index,
+                   format_api_error, ntohl (mp->retval));
+      if (rv == VPPCOM_OK)
+       {
+         session->state = STATE_FAILED;
+         session->vpp_handle = mp->handle;
+       }
+      else
+       {
+         clib_warning ("[%s] ERROR: vpp handle 0x%llx, sid %u: "
+                       "Invalid session index (%u)!",
+                       getpid (), mp->handle, session_index);
+       }
+      goto done_unlock;
     }
 
-  session_index = mp->context;
-  if (VPPCOM_DEBUG > 1)
-    clib_warning ("[%d] session_index = %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;
-    }
+  if (rv)
+    goto done_unlock;
 
   /* We've been redirected */
   if (mp->segment_name_length > 0)
@@ -760,29 +981,25 @@ vl_api_connect_session_reply_t_handler (vl_api_connect_session_reply_t * mp)
       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);
+       clib_warning ("VCL<%d>: cut-thru segment: %s\n",
+                     getpid (), a->segment_name);
+
       rv = svm_fifo_segment_attach (a);
       vec_reset_length (a->new_segment_indices);
       if (PREDICT_FALSE (rv))
        {
-         clib_spinlock_unlock (&vcm->sessions_lockp);
-         clib_warning ("[%d] sm_fifo_segment_attach ('%s') failed",
-                       vcm->my_pid, a->segment_name);
-         return;
+         clib_warning ("VCL<%d>: sm_fifo_segment_attach ('%s') failed",
+                       getpid (), a->segment_name);
+         goto done_unlock;
        }
     }
 
   /*
    * 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->vpp_event_queue = uword_to_pointer (mp->vpp_event_queue_address,
-                                              unix_shared_memory_queue_t *);
+                                              svm_queue_t *);
 
   rx_fifo = uword_to_pointer (mp->server_rx_fifo, svm_fifo_t *);
   rx_fifo->client_session_index = session_index;
@@ -791,18 +1008,31 @@ vl_api_connect_session_reply_t_handler (vl_api_connect_session_reply_t * mp)
 
   session->server_rx_fifo = rx_fifo;
   session->server_tx_fifo = tx_fifo;
-  session->vpp_session_handle = mp->handle;
+  session->vpp_handle = mp->handle;
+  session->lcl_addr.is_ip4 = mp->is_ip4;
+  clib_memcpy (&session->lcl_addr.ip46, mp->lcl_ip,
+              sizeof (session->peer_addr.ip46));
+  session->lcl_port = mp->lcl_port;
   session->state = STATE_CONNECT;
 
   /* Add it to lookup table */
   hash_set (vcm->session_index_by_vpp_handles, mp->handle, session_index);
+
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: connect succeeded!"
+                 " session_rx_fifo %p, refcnt %d,"
+                 " session_tx_fifo %p, refcnt %d",
+                 getpid (), mp->handle, session_index,
+                 session->server_rx_fifo,
+                 session->server_rx_fifo->refcnt,
+                 session->server_tx_fifo, session->server_tx_fifo->refcnt);
+done_unlock:
   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 */
@@ -813,10 +1043,6 @@ vppcom_send_connect_sock (session_t * session, u32 session_index)
   cmp->client_index = vcm->my_client_index;
   cmp->context = session_index;
 
-  if (VPPCOM_DEBUG > 1)
-    clib_warning ("[%d] session_index = %d 0x%08x",
-                 vcm->my_pid, session_index, session_index);
-
   cmp->vrf = session->vrf;
   cmp->is_ip4 = session->peer_addr.is_ip4;
   clib_memcpy (cmp->ip, &session->peer_addr.ip46, sizeof (cmp->ip));
@@ -826,80 +1052,101 @@ vppcom_send_connect_sock (session_t * session, u32 session_index)
   vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & cmp);
 }
 
-static int
-vppcom_send_disconnect (u32 session_index)
+static inline void
+vppcom_send_disconnect_session_reply (u64 vpp_handle, u32 session_index,
+                                     int rv)
+{
+  vl_api_disconnect_session_reply_t *rmp;
+
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                 "sending disconnect msg",
+                 getpid (), vpp_handle, session_index);
+
+  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 = vpp_handle;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+}
+
+static inline void
+vppcom_send_disconnect_session (u64 vpp_handle, 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 (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      return rv;
-    }
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                 "sending disconnect msg",
+                 getpid (), vpp_handle, session_index);
 
   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);
+  dmp->handle = vpp_handle;
   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;
+  u32 session_index = mp->context;
   int rv;
 
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+done:
   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_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, "
+                   "sid %u: bind failed: %U",
+                   getpid (), mp->handle, session_index,
+                   format_api_error, ntohl (mp->retval));
+      rv = vppcom_session_at_index (session_index, &session);
+      if (rv == VPPCOM_OK)
+       {
+         session->state = STATE_FAILED;
+         session->vpp_handle = mp->handle;
+       }
+      else
+       {
+         clib_warning ("[%s] ERROR: vpp handle 0x%llx, sid %u: "
+                       "Invalid session index (%u)!",
+                       getpid (), mp->handle, session_index);
+       }
+      goto done_unlock;
     }
+
+  session->vpp_handle = mp->handle;
+  session->lcl_addr.is_ip4 = mp->lcl_is_ip4;
+  clib_memcpy (&session->lcl_addr.ip46, mp->lcl_ip,
+              sizeof (session->peer_addr.ip46));
+  session->lcl_port = mp->lcl_port;
+  vppcom_session_table_add_listener (mp->handle, session_index);
+  session->is_listen = 1;
+  session->state = STATE_LISTEN;
+
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: bind succeeded!",
+                 getpid (), mp->handle, mp->context);
+done_unlock:
   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 (rv == VPPCOM_OK)
-    {
-      if ((VPPCOM_DEBUG > 1) && (mp->retval))
-       clib_warning ("[%d] unbind failed: %U", vcm->my_pid, format_api_error,
-                     ntohl (mp->retval));
+  if (mp->retval)
+    clib_warning ("VCL<%d>: ERROR: sid %u: unbind failed: %U",
+                 getpid (), mp->context, format_api_error,
+                 ntohl (mp->retval));
 
-      vcm->bind_session_index = ~0;
-      session->state = STATE_START;
-    }
-  clib_spinlock_unlock (&vcm->sessions_lockp);
+  else if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: sid %u: unbind succeeded!",
+                 getpid (), mp->context);
 }
 
 u8 *
@@ -985,32 +1232,47 @@ format_ip46_address (u8 * s, va_list * args)
     format (s, "%U", format_ip6_address, &ip46->ip6);
 }
 
+static inline void
+vppcom_send_accept_session_reply (u64 handle, u32 context, int retval)
+{
+  vl_api_accept_session_reply_t *rmp;
+
+  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 (retval);
+  rmp->context = context;
+  rmp->handle = handle;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+}
+
 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;
+  session_t *session, *listen_session;
   u32 session_index;
-  int rv = 0;
 
+  clib_spinlock_lock (&vcm->sessions_lockp);
   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;
+      clib_warning ("VCL<%d>: client session queue is full!", getpid ());
+      vppcom_send_accept_session_reply (mp->handle, mp->context,
+                                       VNET_API_ERROR_QUEUE_FULL);
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      return;
     }
 
-  if (VPPCOM_DEBUG > 1)
+  listen_session = vppcom_session_table_lookup_listener (mp->listener_handle);
+  if (!listen_session)
     {
-      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_warning ("VCL<%d>: ERROR: couldn't find listen session: "
+                   "unknown vpp listener handle %llx",
+                   getpid (), mp->listener_handle);
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      return;
     }
 
-  clib_spinlock_lock (&vcm->sessions_lockp);
   /* Allocate local session and set it up */
   pool_get (vcm->sessions, session);
   memset (session, 0, sizeof (*session));
@@ -1021,10 +1283,12 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   tx_fifo = uword_to_pointer (mp->server_tx_fifo, svm_fifo_t *);
   tx_fifo->client_session_index = session_index;
 
+  session->vpp_handle = mp->handle;
+  session->client_context = mp->context;
   session->server_rx_fifo = rx_fifo;
   session->server_tx_fifo = tx_fifo;
   session->vpp_event_queue = uword_to_pointer (mp->vpp_event_queue_address,
-                                              unix_shared_memory_queue_t *);
+                                              svm_queue_t *);
   session->state = STATE_ACCEPT;
   session->is_cut_thru = 0;
   session->is_server = 1;
@@ -1035,20 +1299,101 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
 
   /* Add it to lookup table */
   hash_set (vcm->session_index_by_vpp_handles, mp->handle, session_index);
+  session->lcl_port = listen_session->lcl_port;
+  session->lcl_addr = listen_session->lcl_addr;
 
+  /* TBD: move client_session_index_fifo into listener session */
   clib_fifo_add1 (vcm->client_session_index_fifo, session_index);
+
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
-  /*
-   * 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);
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: client accept "
+                 "request from %s address %U port %d queue %p!", getpid (),
+                 mp->handle, session_index, mp->is_ip4 ? "IPv4" : "IPv6",
+                 format_ip46_address, &mp->ip, mp->is_ip4,
+                 clib_net_to_host_u16 (mp->port), session->vpp_event_queue);
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      session->elog_track.name =
+       (char *) format (0, "C:%d:S:%d%c", vcm->my_client_index,
+                        session_index, 0);
+      elog_track_register (&vcm->elog_main, &session->elog_track);
+
+      if (session->peer_addr.is_ip4)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+         {
+           .format =
+           "client_accept:handle:%x addr:%d.%d.%d.%d:%d",
+           .format_args = "i8i1i1i1i1i2",
+         };
+
+         CLIB_PACKED (struct {
+           u64 handle; //8
+           u8 addr[4]; //4
+           u16 port;   //2
+         }) * ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+         ed->handle = mp->handle;
+         ed->addr[0] = session->peer_addr.ip46.ip4.as_u8[0];
+         ed->addr[1] = session->peer_addr.ip46.ip4.as_u8[1];
+         ed->addr[2] = session->peer_addr.ip46.ip4.as_u8[2];
+         ed->addr[3] = session->peer_addr.ip46.ip4.as_u8[3];
+         ed->port = clib_net_to_host_u16 (session->peer_port);
+         /* *INDENT-ON* */
+       }
+      else
+       {
+         clib_warning ("ip6");
+       }
+    }
+
+}
+
+static void
+vppcom_send_connect_session_reply (session_t * session, u32 session_index,
+                                  u64 vpp_handle, u32 context, int retval)
+{
+  vl_api_connect_session_reply_t *rmp;
+  u32 len;
+  svm_queue_t *client_q;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_CONNECT_SESSION_REPLY);
+
+  if (!session)
+    {
+      rmp->context = context;
+      rmp->handle = vpp_handle;
+      rmp->retval = htonl (retval);
+      vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+      return;
+    }
+
+  rmp->context = session->client_context;
+  rmp->retval = htonl (retval);
+  rmp->handle = session->vpp_handle;
+  rmp->server_rx_fifo = pointer_to_uword (session->server_rx_fifo);
+  rmp->server_tx_fifo = pointer_to_uword (session->server_tx_fifo);
+  rmp->vpp_event_queue_address = pointer_to_uword (session->vpp_event_queue);
+  rmp->segment_size = vcm->cfg.segment_size;
+  len = vec_len (session->segment_name);
+  rmp->segment_name_length = clib_min (len, sizeof (rmp->segment_name));
+  clib_memcpy (rmp->segment_name, session->segment_name,
+              rmp->segment_name_length - 1);
+  clib_memcpy (rmp->lcl_ip, session->peer_addr.ip46.as_u8,
+              sizeof (rmp->lcl_ip));
+  rmp->is_ip4 = session->peer_addr.is_ip4;
+  rmp->lcl_port = session->peer_port;
+  client_q = uword_to_pointer (session->client_queue_address, svm_queue_t *);
+  ASSERT (client_q);
+  vl_msg_api_send_shmem (client_q, (u8 *) & rmp);
 }
 
 /*
@@ -1057,148 +1402,82 @@ send_reply:
 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_session_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;
 
   clib_spinlock_lock (&vcm->sessions_lockp);
   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;
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      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;
-    }
+       clib_warning ("VCL<%d>: client session queue is full!", getpid ());
 
-  if (VPPCOM_DEBUG > 1)
-    clib_warning ("[%d] created segment '%s'", vcm->my_pid, a->segment_name);
+      /* TBD: Fix api to include vpp handle */
+      vppcom_send_connect_session_reply (0 /* session */ , 0 /* sid */ ,
+                                        0 /* handle */ , mp->context,
+                                        VNET_API_ERROR_QUEUE_FULL);
+      return;
+    }
 
   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_segment_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_context = mp->context;
+  session->vpp_handle = session_index;
   session->client_queue_address = mp->client_queue_address;
   session->is_cut_thru = 1;
   session->is_server = 1;
-  session->peer_port = mp->port;
+  session->lcl_port = mp->port;
+  session->lcl_addr.is_ip4 = mp->is_ip4;
+  clib_memcpy (&session->lcl_addr.ip46, mp->ip,
+              sizeof (session->lcl_addr.ip46));
+
+  /* TBD: missing peer info in api msg.
+   */
   session->peer_addr.is_ip4 = mp->is_ip4;
-  clib_memcpy (&session->peer_addr.ip46, mp->ip,
-              sizeof (session->peer_addr.ip46));
-  {
-    void *oldheap;
-    ssvm_shared_header_t *sh = seg->ssvm.sh;
-
-    ssvm_lock_non_recursive (sh, 1);
-    oldheap = ssvm_push_heap (sh);
-    event_q = session->vpp_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);
-  }
+  ASSERT (session->lcl_addr.is_ip4 == session->peer_addr.is_ip4);
 
   session->state = STATE_ACCEPT;
-  if (VPPCOM_DEBUG > 1)
-    clib_warning ("[%d] Connected cut-thru to client: sid %d",
-                 vcm->my_pid, session_index);
   clib_fifo_add1 (vcm->client_session_index_fifo, session_index);
-  clib_spinlock_unlock (&vcm->sessions_lockp);
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: sid %u: Got a cut-thru connect request! "
+                 "clib_fifo_elts %u!\n", getpid (), session_index,
+                 clib_fifo_elts (vcm->client_session_index_fifo));
 
-send_reply:
-  rmp = vl_msg_api_alloc (sizeof (*rmp));
-  memset (rmp, 0, sizeof (*rmp));
+  if (VPPCOM_DEBUG > 0)
+    {
+      session->elog_track.name =
+       (char *) format (0, "C:%d:S:%d%c", vcm->my_client_index,
+                        session_index, 0);
+      elog_track_register (&vcm->elog_main, &session->elog_track);
 
-  rmp->_vl_msg_id = ntohs (VL_API_CONNECT_SESSION_REPLY);
-  rmp->context = mp->context;
-  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);
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "cut-thru-connect:S:%d clib_fifo_elts:%d",
+       .format_args = "i4i4",
+      };
 
-  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);
+      struct
+      {
+       u32 data[2];
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+      ed->data[0] = session_index;
+      ed->data[1] = clib_fifo_elts (vcm->client_session_index_fifo);
+      /* *INDENT-ON* */
     }
-  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);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
 }
 
 static void
-vppcom_send_bind_sock (session_t * session)
+vppcom_send_bind_sock (session_t * session, u32 session_index)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   vl_api_bind_sock_t *bmp;
 
   /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
@@ -1208,7 +1487,7 @@ vppcom_send_bind_sock (session_t * session)
 
   bmp->_vl_msg_id = ntohs (VL_API_BIND_SOCK);
   bmp->client_index = vcm->my_client_index;
-  bmp->context = htonl (0xfeedface);
+  bmp->context = session_index;
   bmp->vrf = session->vrf;
   bmp->is_ip4 = session->lcl_addr.is_ip4;
   clib_memcpy (bmp->ip, &session->lcl_addr.ip46, sizeof (bmp->ip));
@@ -1219,103 +1498,176 @@ vppcom_send_bind_sock (session_t * session)
 }
 
 static void
-vppcom_send_unbind_sock (u32 session_index)
+vppcom_send_unbind_sock (u64 vpp_handle)
 {
-  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 (%u) 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);
+  ump->handle = vpp_handle;
   vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & ump);
 }
 
 static int
-vppcom_session_unbind_cut_thru (session_t * session)
+vppcom_session_unbind (u32 session_index)
 {
-  svm_fifo_segment_main_t *sm = &svm_fifo_segment_main;
-  svm_fifo_segment_private_t *seg;
-  int rv = VPPCOM_OK;
+  session_t *session = 0;
+  int rv;
+  u64 vpp_handle;
 
-  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);
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+
+  vpp_handle = session->vpp_handle;
+  vppcom_session_table_del_listener (vpp_handle);
+  session->vpp_handle = ~0;
+  session->state = STATE_DISCONNECT;
+
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  if (VPPCOM_DEBUG > 1)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                 "sending unbind msg! new state 0x%x (%s)",
+                 getpid (), vpp_handle, session_index,
+                 session->state, vppcom_session_state_str (session->state));
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "unbind: handle:%x",
+       .format_args = "i8",
+      };
+
+      struct
+      {
+       u64 handle;
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+      ed->handle = vpp_handle;
+      /* *INDENT-ON* */
+    }
+  vppcom_send_unbind_sock (vpp_handle);
 
+done:
   return rv;
 }
 
-static int
-vppcom_session_unbind (u32 session_index)
+static inline int
+vppcom_session_disconnect (u32 session_index)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   int rv;
+  session_t *session;
+  u8 is_cut_thru, is_listen, is_server;
+  u64 vpp_handle;
+  session_state_t state;
 
-  clib_spinlock_lock (&vcm->sessions_lockp);
-  if (PREDICT_FALSE (pool_is_free_index (vcm->sessions, session_index)))
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+
+  vpp_handle = session->vpp_handle;
+  is_server = session->is_server;
+  is_listen = session->is_listen;
+  is_cut_thru = session->is_cut_thru;
+  state = session->state;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  if (VPPCOM_DEBUG > 1)
     {
-      clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 1)
-       clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: %s "
+                   "state 0x%x (%s), is_cut_thru %d, is_listen %d",
+                   getpid (), vpp_handle, session_index,
+                   is_server ? "server" : "client",
+                   state, vppcom_session_state_str (state),
+                   is_cut_thru, is_listen);
     }
-  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))
+  if (PREDICT_FALSE (is_listen))
     {
-      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;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "Cannot disconnect a listen socket!",
+                   getpid (), vpp_handle, session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
-  return VPPCOM_OK;
-}
 
-static int
-vppcom_session_disconnect (u32 session_index)
-{
-  vppcom_main_t *vcm = &vppcom_main;
-  int rv;
+  /* Through the VPP host stack...
+   */
+  else if (!is_cut_thru)
+    {
+      /* The peer has already initiated the close,
+       * so send the disconnect session reply.
+       */
+      if (state & STATE_CLOSE_ON_EMPTY)
+       {
+         vppcom_send_disconnect_session_reply (vpp_handle,
+                                               session_index, 0 /* rv */ );
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                         "sending disconnect REPLY...",
+                         getpid (), vpp_handle, session_index);
+       }
 
-  rv = vppcom_send_disconnect (session_index);
-  if (PREDICT_FALSE (rv))
-    return rv;
+      /* Otherwise, send a disconnect session msg...
+       */
+      else
+       {
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                         "sending disconnect...",
+                         getpid (), vpp_handle, session_index);
 
-  rv = vppcom_wait_for_session_state_change (session_index, STATE_DISCONNECT,
-                                            vcm->cfg.session_timeout);
-  if (PREDICT_FALSE (rv))
+         vppcom_send_disconnect_session (vpp_handle, session_index);
+       }
+    }
+
+  /* Cut-thru connections...
+   *
+   *   server: free fifos and segment allocated during connect/redirect
+   *   client: no cleanup required
+   */
+  else
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] client disconnect timed out, rv = %s (%d)",
-                     vcm->my_pid, vppcom_retval_str (rv), rv);
-      return rv;
+      if (is_server)
+       {
+         svm_fifo_segment_main_t *sm = &svm_fifo_segment_main;
+         svm_fifo_segment_private_t *seg;
+
+         VCL_LOCK_AND_GET_SESSION (session_index, &session);
+
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: sid %d: freeing cut-thru fifos in "
+                         "sm_seg_index %d! "
+                         " server_rx_fifo %p, refcnt = %d"
+                         " server_tx_fifo %p, refcnt = %d",
+                         getpid (), session_index, session->sm_seg_index,
+                         session->server_rx_fifo,
+                         session->server_rx_fifo->refcnt,
+                         session->server_tx_fifo,
+                         session->server_tx_fifo->refcnt);
+
+         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);
+
+         /* TBD: Send cut-thru disconnect event to client */
+
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+       }
+      else
+       {
+         /* TBD: Send cut-thru disconnect event to server */
+       }
     }
-  return VPPCOM_OK;
+
+done:
+  return rv;
 }
 
 #define foreach_sock_msg                                        \
@@ -1352,6 +1704,7 @@ vppcom_cfg_init (vppcom_cfg_t * vcl_cfg)
   ASSERT (vcl_cfg);
 
   vcl_cfg->heapsize = (256ULL << 20);
+  vcl_cfg->vpp_api_q_length = 1024;
   vcl_cfg->segment_baseva = 0x200000000ULL;
   vcl_cfg->segment_size = (256 << 20);
   vcl_cfg->add_segment_size = (128 << 20);
@@ -1363,12 +1716,13 @@ vppcom_cfg_init (vppcom_cfg_t * vcl_cfg)
   vcl_cfg->app_timeout = 10 * 60.0;
   vcl_cfg->session_timeout = 10 * 60.0;
   vcl_cfg->accept_timeout = 60.0;
+  vcl_cfg->event_ring_size = (128 << 10);
+  vcl_cfg->event_log_path = "/dev/shm";
 }
 
 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];
@@ -1379,6 +1733,8 @@ vppcom_cfg_heapsize (char *conf_fname)
   int i;
   u8 *sizep;
   u32 size;
+  void *vcl_mem;
+  void *heap;
 
   fp = fopen (conf_fname, "r");
   if (fp == NULL)
@@ -1443,9 +1799,9 @@ vppcom_cfg_heapsize (char *conf_fname)
          if (size == 0)
            {
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] parse error '%s %s', "
+               clib_warning ("VCL<%d>: parse error '%s %s', "
                              "using default heapsize %lld (0x%llx)",
-                             vcm->my_pid, argv[i], argv[i + 1],
+                             getpid (), argv[i], argv[i + 1],
                              vcl_cfg->heapsize, vcl_cfg->heapsize);
              goto defaulted;
            }
@@ -1457,9 +1813,9 @@ vppcom_cfg_heapsize (char *conf_fname)
          else
            {
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] parse error '%s %s', "
+               clib_warning ("VCL<%d>: parse error '%s %s', "
                              "using default heapsize %lld (0x%llx)",
-                             vcm->my_pid, argv[i], argv[i + 1],
+                             getpid (), argv[i], argv[i + 1],
                              vcl_cfg->heapsize, vcl_cfg->heapsize);
              goto defaulted;
            }
@@ -1471,17 +1827,41 @@ defaulted:
     fclose (fp);
   if (argv != NULL)
     free (argv);
-  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);
+
+  vcl_mem = mmap (0, vcl_cfg->heapsize, PROT_READ | PROT_WRITE,
+                 MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+  if (vcl_mem == MAP_FAILED)
+    {
+      clib_unix_error ("VCL<%d>: ERROR: mmap(0, %lld == 0x%llx, "
+                      "PROT_READ | PROT_WRITE,MAP_SHARED | MAP_ANONYMOUS, "
+                      "-1, 0) failed!",
+                      getpid (), vcl_cfg->heapsize, vcl_cfg->heapsize);
+      return;
+    }
+  heap = clib_mem_init (vcl_mem, vcl_cfg->heapsize);
+  if (!heap)
+    {
+      clib_warning ("VCL<%d>: ERROR: clib_mem_init() failed!", getpid ());
+      return;
+    }
+  vcl_mem = clib_mem_alloc (sizeof (_vppcom_main));
+  if (!vcl_mem)
+    {
+      clib_warning ("VCL<%d>: ERROR: clib_mem_alloc() failed!", getpid ());
+      return;
+    }
+
+  clib_memcpy (vcl_mem, &_vppcom_main, sizeof (_vppcom_main));
+  vcm = vcl_mem;
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("VCL<%d>: allocated VCL heap = %p, size %lld (0x%llx)",
+                 getpid (), heap, 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;
@@ -1489,29 +1869,29 @@ vppcom_cfg_read (char *conf_fname)
   u8 vc_cfg_input = 0;
   u8 *chroot_path;
   struct stat s;
-  u32 uid, gid;
+  u32 uid, gid, q_len;
 
   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);
+       clib_warning ("VCL<%d>: open configuration file '%s' failed!",
+                     getpid (), 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);
+       clib_warning ("VCL<%d>: failed to stat `%s'", getpid (), 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);
+       clib_warning ("VCL<%d>: not a regular file `%s'",
+                     getpid (), conf_fname);
       goto file_done;
     }
 
@@ -1534,9 +1914,9 @@ vppcom_cfg_read (char *conf_fname)
            {
              vec_terminate_c_string (chroot_path);
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] configured heapsize %s, "
+               clib_warning ("VCL<%d>: configured heapsize %s, "
                              "actual heapsize %lld (0x%llx)",
-                             vcm->my_pid, chroot_path, vcl_cfg->heapsize,
+                             getpid (), chroot_path, vcl_cfg->heapsize,
                              vcl_cfg->heapsize);
              vec_free (chroot_path);
            }
@@ -1545,43 +1925,60 @@ vppcom_cfg_read (char *conf_fname)
              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);
+               clib_warning ("VCL<%d>: configured api-prefix %s",
+                             getpid (), chroot_path);
              chroot_path = 0;  /* Don't vec_free() it! */
            }
+         else if (unformat (line_input, "vpp-api-q-length %d", &q_len))
+           {
+             if (q_len < vcl_cfg->vpp_api_q_length)
+               {
+                 clib_warning ("VCL<%d>: ERROR: configured vpp-api-q-length "
+                               "(%u) is too small! Using default: %u ",
+                               getpid (), q_len, vcl_cfg->vpp_api_q_length);
+               }
+             else
+               {
+                 vcl_cfg->vpp_api_q_length = q_len;
+
+                 if (VPPCOM_DEBUG > 0)
+                   clib_warning ("VCL<%d>: configured vpp-api-q-length %u",
+                                 getpid (), vcl_cfg->vpp_api_q_length);
+               }
+           }
          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);
+               clib_warning ("VCL<%d>: configured uid %d", getpid (), 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);
+               clib_warning ("VCL<%d>: configured gid %d", getpid (), gid);
            }
          else if (unformat (line_input, "segment-baseva 0x%lx",
                             &vcl_cfg->segment_baseva))
            {
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] configured segment_baseva 0x%lx",
-                             vcm->my_pid, vcl_cfg->segment_baseva);
+               clib_warning ("VCL<%d>: configured segment_baseva 0x%lx",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured segment_size 0x%lx (%ld)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured segment_size %ld (0x%lx)",
+                             getpid (), vcl_cfg->segment_size,
                              vcl_cfg->segment_size);
            }
          else if (unformat (line_input, "add-segment-size 0x%lx",
@@ -1589,8 +1986,8 @@ vppcom_cfg_read (char *conf_fname)
            {
              if (VPPCOM_DEBUG > 0)
                clib_warning
-                 ("[%d] configured add_segment_size 0x%lx (%ld)",
-                  vcm->my_pid, vcl_cfg->add_segment_size,
+                 ("VCL<%d>: configured add_segment_size 0x%lx (%ld)",
+                  getpid (), vcl_cfg->add_segment_size,
                   vcl_cfg->add_segment_size);
            }
          else if (unformat (line_input, "add-segment-size %ld",
@@ -1598,16 +1995,16 @@ vppcom_cfg_read (char *conf_fname)
            {
              if (VPPCOM_DEBUG > 0)
                clib_warning
-                 ("[%d] configured add_segment_size %ld (0x%lx)",
-                  vcm->my_pid, vcl_cfg->add_segment_size,
+                 ("VCL<%d>: configured add_segment_size %ld (0x%lx)",
+                  getpid (), 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,
+               clib_warning ("VCL<%d>: configured preallocated_fifo_pairs "
+                             "%d (0x%x)", getpid (),
                              vcl_cfg->preallocated_fifo_pairs,
                              vcl_cfg->preallocated_fifo_pairs);
            }
@@ -1615,117 +2012,128 @@ vppcom_cfg_read (char *conf_fname)
                             &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,
+               clib_warning ("VCL<%d>: configured rx_fifo_size 0x%lx (%ld)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured rx_fifo_size %ld (0x%lx)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured tx_fifo_size 0x%lx (%ld)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured tx_fifo_size %ld (0x%lx)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured event_queue_size "
+                             "0x%lx (%ld)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured event_queue_size "
+                             "%ld (0x%lx)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured listen_queue_size "
+                             "0x%lx (%ld)",
+                             getpid (), 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,
+               clib_warning ("VCL<%d>: configured listen_queue_size "
+                             "%ld (0x%lx)",
+                             getpid (), 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);
+               clib_warning ("VCL<%d>: configured app_timeout %f",
+                             getpid (), 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);
+               clib_warning ("VCL<%d>: configured session_timeout %f",
+                             getpid (), 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);
+               clib_warning ("VCL<%d>: configured accept_timeout %f",
+                             getpid (), vcl_cfg->accept_timeout);
            }
-         else if (unformat (line_input, "session-scope-local"))
+         else if (unformat (line_input, "app-proxy-transport-tcp"))
            {
-             vcl_cfg->session_scope_local = 1;
+             vcl_cfg->app_proxy_transport_tcp = 1;
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] configured session_scope_local (%d)",
-                             vcm->my_pid, vcl_cfg->session_scope_local);
+               clib_warning ("VCL<%d>: configured "
+                             "app_proxy_transport_tcp (%d)",
+                             getpid (), vcl_cfg->app_proxy_transport_tcp);
            }
-         else if (unformat (line_input, "session-scope-global"))
+         else if (unformat (line_input, "app-proxy-transport-udp"))
            {
-             vcl_cfg->session_scope_global = 1;
+             vcl_cfg->app_proxy_transport_udp = 1;
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] configured session_scope_global (%d)",
-                             vcm->my_pid, vcl_cfg->session_scope_global);
+               clib_warning ("VCL<%d>: configured "
+                             "app_proxy_transport_udp (%d)",
+                             getpid (), vcl_cfg->app_proxy_transport_udp);
            }
-         else if (unformat (line_input, "namespace-secret 0x%lx",
-                            &vcl_cfg->namespace_secret))
+         else if (unformat (line_input, "app-scope-local"))
            {
+             vcl_cfg->app_scope_local = 1;
              if (VPPCOM_DEBUG > 0)
-               clib_warning
-                 ("[%d] configured namespace_secret 0x%lx (%lu)",
-                  vcm->my_pid, vcl_cfg->namespace_secret,
-                  vcl_cfg->namespace_secret);
+               clib_warning ("VCL<%d>: configured app_scope_local (%d)",
+                             getpid (), vcl_cfg->app_scope_local);
+           }
+         else if (unformat (line_input, "app-scope-global"))
+           {
+             vcl_cfg->app_scope_global = 1;
+             if (VPPCOM_DEBUG > 0)
+               clib_warning ("VCL<%d>: configured app_scope_global (%d)",
+                             getpid (), vcl_cfg->app_scope_global);
            }
          else if (unformat (line_input, "namespace-secret %lu",
                             &vcl_cfg->namespace_secret))
            {
              if (VPPCOM_DEBUG > 0)
                clib_warning
-                 ("[%d] configured namespace_secret %lu (0x%lx)",
-                  vcm->my_pid, vcl_cfg->namespace_secret,
+                 ("VCL<%d>: configured namespace_secret %lu (0x%lx)",
+                  getpid (), vcl_cfg->namespace_secret,
                   vcl_cfg->namespace_secret);
            }
          else if (unformat (line_input, "namespace-id %v",
@@ -1738,29 +2146,29 @@ vppcom_cfg_read (char *conf_fname)
                {
                  _vec_len (vcl_cfg->namespace_id) = max_nsid_vec_len;
                  if (VPPCOM_DEBUG > 0)
-                   clib_warning ("[%d] configured namespace_id is too long,"
-                                 " truncated to %d characters!", vcm->my_pid,
-                                 max_nsid_vec_len);
+                   clib_warning ("VCL<%d>: configured namespace_id is "
+                                 "too long, truncated to %d characters!",
+                                 getpid (), max_nsid_vec_len);
                }
 
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] configured namespace_id %v",
-                             vcm->my_pid, vcl_cfg->namespace_id);
+               clib_warning ("VCL<%d>: configured namespace_id %v",
+                             getpid (), vcl_cfg->namespace_id);
            }
          else if (unformat (line_input, "}"))
            {
              vc_cfg_input = 0;
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] completed parsing vppcom config!",
-                             vcm->my_pid);
+               clib_warning ("VCL<%d>: completed parsing vppcom config!",
+                             getpid ());
              goto input_done;
            }
          else
            {
              if (line_input->buffer[line_input->index] != '#')
                {
-                 clib_warning ("[%d] Unknown vppcom config option: '%s'",
-                               vcm->my_pid, (char *)
+                 clib_warning ("VCL<%d>: Unknown vppcom config option: '%s'",
+                               getpid (), (char *)
                                &line_input->buffer[line_input->index]);
                }
            }
@@ -1781,7 +2189,6 @@ file_done:
 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;
@@ -1793,19 +2200,34 @@ vppcom_app_create (char *app_name)
       char *env_var_str;
 
       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);
+      env_var_str = getenv (VPPCOM_ENV_DEBUG);
+      if (env_var_str)
+       {
+         u32 tmp;
+         if (sscanf (env_var_str, "%u", &tmp) != 1)
+           clib_warning ("VCL<%d>: Invalid debug level specified in "
+                         "the environment variable "
+                         VPPCOM_ENV_DEBUG
+                         " (%s)!\n", getpid (), env_var_str);
+         else
+           {
+             vcm->debug = tmp;
+             clib_warning ("VCL<%d>: configured VCL debug level (%u) from "
+                           VPPCOM_ENV_DEBUG "!", getpid (), vcm->debug);
+           }
+       }
       conf_fname = getenv (VPPCOM_ENV_CONF);
       if (!conf_fname)
        {
          conf_fname = VPPCOM_CONF_DEFAULT;
          if (VPPCOM_DEBUG > 0)
-           clib_warning ("[%d] getenv '%s' failed!", vcm->my_pid,
+           clib_warning ("VCL<%d>: getenv '%s' failed!", getpid (),
                          VPPCOM_ENV_CONF);
        }
       vppcom_cfg_heapsize (conf_fname);
+      clib_fifo_validate (vcm->client_session_index_fifo,
+                         vcm->cfg.listen_queue_size);
       vppcom_cfg_read (conf_fname);
       env_var_str = getenv (VPPCOM_ENV_APP_NAMESPACE_ID);
       if (env_var_str)
@@ -1817,8 +2239,8 @@ vppcom_app_create (char *app_name)
          clib_memcpy (vcm->cfg.namespace_id, env_var_str, ns_id_vec_len);
 
          if (VPPCOM_DEBUG > 0)
-           clib_warning ("[%d] configured namespace_id (%v) from "
-                         VPPCOM_ENV_APP_NAMESPACE_ID "!", vcm->my_pid,
+           clib_warning ("VCL<%d>: configured namespace_id (%v) from "
+                         VPPCOM_ENV_APP_NAMESPACE_ID "!", getpid (),
                          vcm->cfg.namespace_id);
        }
       env_var_str = getenv (VPPCOM_ENV_APP_NAMESPACE_SECRET);
@@ -1826,37 +2248,52 @@ vppcom_app_create (char *app_name)
        {
          u64 tmp;
          if (sscanf (env_var_str, "%lu", &tmp) != 1)
-           clib_warning ("[%d] Invalid namespace secret specified in "
+           clib_warning ("VCL<%d>: Invalid namespace secret specified in "
                          "the environment variable "
                          VPPCOM_ENV_APP_NAMESPACE_SECRET
-                         " (%s)!\n", vcm->my_pid, env_var_str);
+                         " (%s)!\n", getpid (), env_var_str);
          else
            {
              vcm->cfg.namespace_secret = tmp;
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("[%d] configured namespace secret (%lu) from "
-                             VPPCOM_ENV_APP_NAMESPACE_ID "!", vcm->my_pid,
-                             vcm->cfg.namespace_secret);
+               clib_warning ("VCL<%d>: configured namespace secret "
+                             "(%lu) from " VPPCOM_ENV_APP_NAMESPACE_ID "!",
+                             getpid (), vcm->cfg.namespace_secret);
            }
        }
-      if (getenv (VPPCOM_ENV_SESSION_SCOPE_LOCAL))
+      if (getenv (VPPCOM_ENV_APP_PROXY_TRANSPORT_TCP))
+       {
+         vcm->cfg.app_proxy_transport_tcp = 1;
+         if (VPPCOM_DEBUG > 0)
+           clib_warning ("VCL<%d>: configured app_proxy_transport_tcp "
+                         "(%u) from " VPPCOM_ENV_APP_PROXY_TRANSPORT_TCP
+                         "!", getpid (), vcm->cfg.app_proxy_transport_tcp);
+       }
+      if (getenv (VPPCOM_ENV_APP_PROXY_TRANSPORT_UDP))
+       {
+         vcm->cfg.app_proxy_transport_udp = 1;
+         if (VPPCOM_DEBUG > 0)
+           clib_warning ("VCL<%d>: configured app_proxy_transport_udp "
+                         "(%u) from " VPPCOM_ENV_APP_PROXY_TRANSPORT_UDP
+                         "!", getpid (), vcm->cfg.app_proxy_transport_udp);
+       }
+      if (getenv (VPPCOM_ENV_APP_SCOPE_LOCAL))
        {
-         vcm->cfg.session_scope_local = 1;
+         vcm->cfg.app_scope_local = 1;
          if (VPPCOM_DEBUG > 0)
-           clib_warning ("[%d] configured session_scope_local (%u) from "
-                         VPPCOM_ENV_SESSION_SCOPE_LOCAL "!", vcm->my_pid,
-                         vcm->cfg.session_scope_local);
+           clib_warning ("VCL<%d>: configured app_scope_local (%u) from "
+                         VPPCOM_ENV_APP_SCOPE_LOCAL "!", getpid (),
+                         vcm->cfg.app_scope_local);
        }
-      if (getenv (VPPCOM_ENV_SESSION_SCOPE_GLOBAL))
+      if (getenv (VPPCOM_ENV_APP_SCOPE_GLOBAL))
        {
-         vcm->cfg.session_scope_global = 1;
+         vcm->cfg.app_scope_global = 1;
          if (VPPCOM_DEBUG > 0)
-           clib_warning ("[%d] configured session_scope_global (%u) from "
-                         VPPCOM_ENV_SESSION_SCOPE_GLOBAL "!", vcm->my_pid,
-                         vcm->cfg.session_scope_global);
+           clib_warning ("VCL<%d>: configured app_scope_global (%u) from "
+                         VPPCOM_ENV_APP_SCOPE_GLOBAL "!", getpid (),
+                         vcm->cfg.app_scope_global);
        }
 
-      vcm->bind_session_index = ~0;
       vcm->main_cpu = os_get_thread_index ();
       heap = clib_mem_get_per_cpu_heap ();
       h = mheap_header (heap);
@@ -1871,45 +2308,47 @@ vppcom_app_create (char *app_name)
       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)
     {
+      vppcom_api_hookup ();
       vcm->app_state = STATE_APP_START;
       rv = vppcom_connect_to_vpp (app_name);
       if (rv)
        {
-         clib_warning ("[%d] couldn't connect to VPP.", vcm->my_pid);
+         clib_warning ("VCL<%d>: ERROR: couldn't connect to VPP!",
+                       getpid ());
          return rv;
        }
 
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] sending session enable", vcm->my_pid);
+       clib_warning ("VCL<%d>: sending session enable", getpid ());
 
       rv = vppcom_app_session_enable ();
       if (rv)
        {
-         clib_warning ("[%d] vppcom_app_session_enable() failed!",
-                       vcm->my_pid);
+         clib_warning ("VCL<%d>: ERROR: vppcom_app_session_enable() "
+                       "failed!", getpid ());
          return rv;
        }
 
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] sending app attach", vcm->my_pid);
+       clib_warning ("VCL<%d>: sending app attach", getpid ());
 
       rv = vppcom_app_attach ();
       if (rv)
        {
-         clib_warning ("[%d] vppcom_app_attach() failed!", vcm->my_pid);
+         clib_warning ("VCL<%d>: ERROR: vppcom_app_attach() failed!",
+                       getpid ());
          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);
+      if (VPPCOM_DEBUG > 0)
+       clib_warning ("VCL<%d>: app_name '%s', my_client_index %d (0x%x)",
+                     getpid (), app_name, vcm->my_client_index,
+                     vcm->my_client_index);
+    }
 
   return VPPCOM_OK;
 }
@@ -1917,24 +2356,47 @@ vppcom_app_create (char *app_name)
 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);
+    clib_warning ("VCL<%d>: detaching from VPP, my_client_index %d (0x%x)",
+                 getpid (), vcm->my_client_index, vcm->my_client_index);
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "app_detach:C:%d",
+       .format_args = "i4",
+      };
+
+      struct
+      {
+       u32 data;
+      } *ed;
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, vcm->elog_track);
+      ed->data = vcm->my_client_index;
+      /* *INDENT-ON* */
+    }
 
   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);
+       clib_warning ("VCL<%d>: application detach timed out! "
+                     "returning %d (%s)",
+                     getpid (), rv, vppcom_retval_str (rv));
     }
+
+  /* Finished with logging before client gets reset to ~0 */
+  if (VPPCOM_DEBUG > 0)
+    write_elog ();
+
   vl_client_disconnect_from_vlib ();
   vcm->my_client_index = ~0;
   vcm->app_state = STATE_APP_START;
@@ -1943,7 +2405,6 @@ vppcom_app_destroy (void)
 int
 vppcom_session_create (u32 vrf, u8 proto, u8 is_nonblocking)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *session;
   u32 session_index;
 
@@ -1956,10 +2417,38 @@ vppcom_session_create (u32 vrf, u8 proto, u8 is_nonblocking)
   session->proto = proto;
   session->state = STATE_START;
   session->is_nonblocking = is_nonblocking ? 1 : 0;
+  session->vpp_handle = ~0;
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d", vcm->my_pid, session_index);
+    clib_warning ("VCL<%d>: sid %u", getpid (), session_index);
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      session->elog_track.name =
+       (char *) format (0, "C:%d:S:%d%c", vcm->my_client_index,
+                        session_index, 0);
+      elog_track_register (&vcm->elog_main, &session->elog_track);
+
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "session_create:vrf:%d proto:%d state:%d is_nonblocking:%d",
+       .format_args = "i4i4i4i4",
+      };
+
+      struct
+      {
+       u32 data[4];
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+      ed->data[0] = session->vrf;
+      ed->data[1] = session->proto;
+      ed->data[2] = session->state;
+      ed->data[3] = session->is_nonblocking;
+      /* *INDENT-ON* */
+    }
 
   return (int) session_index;
 }
@@ -1967,138 +2456,156 @@ vppcom_session_create (u32 vrf, u8 proto, u8 is_nonblocking)
 int
 vppcom_session_close (uint32_t session_index)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *session = 0;
   int rv;
+  u8 is_listen;
+  u8 is_vep;
+  u8 is_vep_session;
+  u32 next_sid;
+  u32 vep_idx;
+  u64 vpp_handle;
+  uword *p;
+  session_state_t state;
 
-  clib_spinlock_lock (&vcm->sessions_lockp);
-  rv = vppcom_session_at_index (session_index, &session);
-  if (PREDICT_FALSE (rv))
-    {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      clib_spinlock_unlock (&vcm->sessions_lockp);
-      goto done;
-    }
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+  is_listen = session->is_listen;
+  is_vep = session->is_vep;
+  is_vep_session = session->is_vep_session;
+  next_sid = session->vep.next_sid;
+  vep_idx = session->vep.vep_idx;
+  state = session->state;
+  vpp_handle = session->vpp_handle;
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d", vcm->my_pid, session_index);
+    {
+      if (is_vep)
+       clib_warning ("VCL<%d>: vep_idx %u / sid %u: "
+                     "closing epoll session...",
+                     getpid (), session_index, session_index);
+      else
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %d: "
+                     "closing session...",
+                     getpid (), vpp_handle, session_index);
+    }
 
-  if (session->is_vep)
+  if (is_vep)
     {
-      u32 next_sid;
-      for (next_sid = session->vep.next_sid; next_sid != ~0;
-          next_sid = session->vep.next_sid)
+      while (next_sid != ~0)
        {
          rv = vppcom_epoll_ctl (session_index, EPOLL_CTL_DEL, next_sid, 0);
-         if ((VPPCOM_DEBUG > 0) && (rv < 0))
-           clib_warning ("[%d] EPOLL_CTL_DEL vep_idx %u, sid %u failed, "
-                         "rv = %s (%d)", session_index, next_sid,
-                         vcm->my_pid, session_index,
-                         vppcom_retval_str (rv), rv);
+         if ((VPPCOM_DEBUG > 0) && PREDICT_FALSE (rv < 0))
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                         "EPOLL_CTL_DEL vep_idx %u failed! rv %d (%s)",
+                         getpid (), vpp_handle, next_sid, vep_idx,
+                         rv, vppcom_retval_str (rv));
 
-         clib_spinlock_lock (&vcm->sessions_lockp);
-         rv = vppcom_session_at_index (session_index, &session);
-         if (PREDICT_FALSE (rv))
-           {
-             if (VPPCOM_DEBUG > 0)
-               clib_warning
-                 ("[%d] invalid session, sid (%u) has been closed!",
-                  vcm->my_pid, session_index);
-             clib_spinlock_unlock (&vcm->sessions_lockp);
-             goto done;
-           }
+         VCL_LOCK_AND_GET_SESSION (session_index, &session);
+         next_sid = session->vep.next_sid;
          clib_spinlock_unlock (&vcm->sessions_lockp);
        }
     }
   else
     {
-      if (session->is_vep_session)
+      if (is_vep_session)
        {
-         u32 vep_idx = session->vep.vep_idx;
          rv = vppcom_epoll_ctl (vep_idx, EPOLL_CTL_DEL, session_index, 0);
          if ((VPPCOM_DEBUG > 0) && (rv < 0))
-           clib_warning ("[%d] EPOLL_CTL_DEL vep_idx %u, sid %u failed, "
-                         "rv = %s (%d)", vep_idx, session_index,
-                         vcm->my_pid, session_index,
-                         vppcom_retval_str (rv), rv);
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                         "EPOLL_CTL_DEL vep_idx %u failed! rv %d (%s)",
+                         getpid (), vpp_handle, session_index,
+                         vep_idx, rv, vppcom_retval_str (rv));
+       }
 
-         clib_spinlock_lock (&vcm->sessions_lockp);
-         rv = vppcom_session_at_index (session_index, &session);
-         if (PREDICT_FALSE (rv))
+      if (is_listen)
+       {
+         if (state == STATE_LISTEN)
            {
-             if (VPPCOM_DEBUG > 0)
-               clib_warning
-                 ("[%d] invalid session, sid (%u) has been closed!",
-                  vcm->my_pid, session_index);
-             clib_spinlock_unlock (&vcm->sessions_lockp);
-             goto done;
+             rv = vppcom_session_unbind (session_index);
+             if (PREDICT_FALSE (rv < 0))
+               {
+                 if (VPPCOM_DEBUG > 0)
+                   clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                                 "listener unbind failed! rv %d (%s)",
+                                 getpid (), vpp_handle, session_index,
+                                 rv, vppcom_retval_str (rv));
+               }
            }
-         clib_spinlock_unlock (&vcm->sessions_lockp);
        }
 
-      if (session->is_cut_thru && session->is_server &&
-         (session->state == STATE_ACCEPT))
-       {
-         rv = vppcom_session_unbind_cut_thru (session);
-         if ((VPPCOM_DEBUG > 0) && (rv < 0))
-           clib_warning ("[%d] unbind cut-thru (session %d) failed, "
-                         "rv = %s (%d)",
-                         vcm->my_pid, session_index,
-                         vppcom_retval_str (rv), rv);
-       }
-      else if (session->is_server && session->is_listen)
-       {
-         rv = vppcom_session_unbind (session_index);
-         if ((VPPCOM_DEBUG > 0) && (rv < 0))
-           clib_warning ("[%d] unbind (session %d) failed, rv = %s (%d)",
-                         vcm->my_pid, session_index,
-                         vppcom_retval_str (rv), rv);
-       }
-      else if (session->state == STATE_CONNECT)
+      else if (state & (CLIENT_STATE_OPEN | SERVER_STATE_OPEN))
        {
          rv = vppcom_session_disconnect (session_index);
-         if ((VPPCOM_DEBUG > 0) && (rv < 0))
-           clib_warning ("[%d] disconnect (session %d) failed, rv = %s (%d)",
-                         vcm->my_pid, session_index,
-                         vppcom_retval_str (rv), rv);
+         if (PREDICT_FALSE (rv < 0))
+           clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                         "session disconnect failed! rv %d (%s)",
+                         getpid (), vpp_handle, session_index,
+                         rv, vppcom_retval_str (rv));
        }
     }
+
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+  vpp_handle = session->vpp_handle;
+  if (vpp_handle != ~0)
+    {
+      p = hash_get (vcm->session_index_by_vpp_handles, vpp_handle);
+      if (p)
+       hash_unset (vcm->session_index_by_vpp_handles, vpp_handle);
+    }
   pool_put_index (vcm->sessions, session_index);
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      if (is_vep)
+       clib_warning ("VCL<%d>: vep_idx %u / sid %u: epoll session removed.",
+                     getpid (), session_index, session_index);
+      else
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: session removed.",
+                     getpid (), vpp_handle, session_index);
+    }
 done:
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "session_close:rv:%d",
+       .format_args = "i4",
+      };
+
+      struct
+      {
+       u32 data;
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+      ed->data = rv;
+      /* *INDENT-ON* */
+    }
+
   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 (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      return rv;
-    }
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
 
   if (session->is_vep)
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: ERROR: sid %u: cannot "
+                   "bind to an epoll session!", getpid (), session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
   session->vrf = ep->vrf;
@@ -2107,126 +2614,146 @@ vppcom_session_bind (uint32_t session_index, vppcom_endpt_t * ep)
   session->lcl_port = ep->port;
 
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d, bound to lcl address %U lcl port %u",
-                 vcm->my_pid, session_index, format_ip46_address,
-                 &session->lcl_addr.ip46, session->lcl_addr.is_ip4,
-                 clib_net_to_host_u16 (session->lcl_port));
+    clib_warning ("VCL<%d>: sid %u: binding to local %s address %U "
+                 "port %u, proto %s", getpid (), session_index,
+                 session->lcl_addr.is_ip4 ? "IPv4" : "IPv6",
+                 format_ip46_address, &session->lcl_addr.ip46,
+                 session->lcl_addr.is_ip4,
+                 clib_net_to_host_u16 (session->lcl_port),
+                 session->proto ? "UDP" : "TCP");
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      if (session->lcl_addr.is_ip4)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+         {
+           .format = "bind local:%s:%d.%d.%d.%d:%d ",
+           .format_args = "t1i1i1i1i1i2",
+           .n_enum_strings = 2,
+           .enum_strings = {"TCP", "UDP",},
+         };
+
+         CLIB_PACKED (struct {
+           u8 proto;
+           u8 addr[4];
+           u16 port;
+         }) * ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+         ed->proto = session->proto;
+         ed->addr[0] = session->lcl_addr.ip46.ip4.as_u8[0];
+         ed->addr[1] = session->lcl_addr.ip46.ip4.as_u8[1];
+         ed->addr[2] = session->lcl_addr.ip46.ip4.as_u8[2];
+         ed->addr[3] = session->lcl_addr.ip46.ip4.as_u8[3];
+         ed->port = clib_net_to_host_u16 (session->lcl_port);
+         /* *INDENT-ON* */
+       }
+    }
 
   clib_spinlock_unlock (&vcm->sessions_lockp);
-  return VPPCOM_OK;
+done:
+  return rv;
 }
 
 int
 vppcom_session_listen (uint32_t listen_session_index, uint32_t q_len)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *listen_session = 0;
-  int rv;
+  u64 listen_vpp_handle;
+  int rv, retval;
 
-  clib_spinlock_lock (&vcm->sessions_lockp);
-  rv = vppcom_session_at_index (listen_session_index, &listen_session);
-  if (PREDICT_FALSE (rv))
+  VCL_LOCK_AND_GET_SESSION (listen_session_index, &listen_session);
+
+  if (listen_session->is_vep)
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                     vcm->my_pid, listen_session_index);
-      return rv;
+      clib_warning ("VCL<%d>: ERROR: sid %u: cannot listen on an "
+                   "epoll session!", getpid (), listen_session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
-  if (listen_session->is_vep)
+  listen_vpp_handle = listen_session->vpp_handle;
+  if (listen_session->is_listen)
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, listen_session_index);
-      return VPPCOM_EBADFD;
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "already in listen state!",
+                     getpid (), listen_vpp_handle, listen_session_index);
+      rv = VPPCOM_OK;
+      goto done;
     }
 
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d", vcm->my_pid, listen_session_index);
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, "
+                 "sid %u: sending bind request...",
+                 getpid (), listen_vpp_handle, listen_session_index);
 
-  ASSERT (vcm->bind_session_index == ~0);
-  vcm->bind_session_index = listen_session_index;
-  vppcom_send_bind_sock (listen_session);
+  vppcom_send_bind_sock (listen_session, listen_session_index);
   clib_spinlock_unlock (&vcm->sessions_lockp);
-  rv =
+  retval =
     vppcom_wait_for_session_state_change (listen_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 (listen_session_index, &listen_session);
-  if (PREDICT_FALSE (rv))
+  VCL_LOCK_AND_GET_SESSION (listen_session_index, &listen_session);
+  if (PREDICT_FALSE (retval))
     {
-      clib_spinlock_unlock (&vcm->sessions_lockp);
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                     vcm->my_pid, listen_session_index);
-      return rv;
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: bind failed! "
+                     "returning %d (%s)", getpid (),
+                     listen_session->vpp_handle, listen_session_index,
+                     retval, vppcom_retval_str (retval));
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      rv = retval;
+      goto done;
     }
-  listen_session->is_listen = 1;
+
   clib_fifo_validate (vcm->client_session_index_fifo, q_len);
   clib_spinlock_unlock (&vcm->sessions_lockp);
-
-  return VPPCOM_OK;
+done:
+  return rv;
 }
 
 int
 vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
-                      double wait_for_time)
+                      uint32_t flags)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *listen_session = 0;
   session_t *client_session = 0;
-  u32 client_session_index;
+  u32 client_session_index = ~0;
   int rv;
   f64 wait_for;
+  char *cut_thru_str;
+  u64 listen_vpp_handle;
 
-  clib_spinlock_lock (&vcm->sessions_lockp);
-  rv = vppcom_session_at_index (listen_session_index, &listen_session);
-  if (PREDICT_FALSE (rv))
-    {
-      clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                     vcm->my_pid, listen_session_index);
-      return rv;
-    }
+  VCL_LOCK_AND_GET_SESSION (listen_session_index, &listen_session);
 
   if (listen_session->is_vep)
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, listen_session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: ERROR: sid %u: cannot accept on an "
+                   "epoll session!", getpid (), listen_session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
+  listen_vpp_handle = listen_session->vpp_handle;
   if (listen_session->state != STATE_LISTEN)
     {
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "not in listen state! state 0x%x (%s)", getpid (),
+                   listen_vpp_handle, listen_session_index,
+                   listen_session->state,
+                   vppcom_session_state_str (listen_session->state));
       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 (listen_session->state));
-      return VPPCOM_EBADFD;
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
-  wait_for = listen_session->is_nonblocking ? 0 :
-    (wait_for_time < 0) ? vcm->cfg.accept_timeout : wait_for_time;
+  wait_for = (listen_session->is_nonblocking) ? 0 : vcm->cfg.accept_timeout;
 
-  if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d: %s (%d)", vcm->my_pid,
-                 listen_session_index,
-                 vppcom_session_state_str (listen_session->state),
-                 listen_session->state);
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   while (1)
@@ -2235,11 +2762,12 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
       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;
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                         "accept failed! returning %d (%s)", getpid (),
+                         listen_vpp_handle, listen_session_index,
+                         rv, vppcom_retval_str (rv));
+         if (wait_for == 0)
+           goto done;
        }
       else
        break;
@@ -2248,72 +2776,278 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
   clib_spinlock_lock (&vcm->sessions_lockp);
   clib_fifo_sub1 (vcm->client_session_index_fifo, client_session_index);
   rv = vppcom_session_at_index (client_session_index, &client_session);
-  ASSERT (rv == VPPCOM_OK);
-  ASSERT (client_session->peer_addr.is_ip4 ==
-         listen_session->lcl_addr.is_ip4);
+  if (PREDICT_FALSE (rv))
+    {
+      rv = VPPCOM_ECONNABORTED;
+      clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: client sid %u "
+                   "lookup failed! returning %d (%s)", getpid (),
+                   listen_vpp_handle, listen_session_index,
+                   client_session_index, rv, vppcom_retval_str (rv));
+      goto done;
+    }
 
+  client_session->is_nonblocking = (flags & O_NONBLOCK) ? 1 : 0;
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] Got a request: client sid %d", vcm->my_pid,
-                 client_session_index);
-
-  // Copy the lcl information from the listening session to the client session
-  //  client_session->lcl_port = listen_session->lcl_port;
-  //  client_session->lcl_addr = listen_session->lcl_addr;
-
-  ep->vrf = client_session->vrf;
-  ep->is_cut_thru = client_session->is_cut_thru;
-  ep->is_ip4 = client_session->peer_addr.is_ip4;
-  ep->port = client_session->peer_port;
-  if (client_session->peer_addr.is_ip4)
-    clib_memcpy (ep->ip, &client_session->peer_addr.ip46.ip4,
-                sizeof (ip4_address_t));
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: Got a client request! "
+                 "vpp handle 0x%llx, sid %u, flags %d, is_nonblocking %u",
+                 getpid (), listen_vpp_handle, listen_session_index,
+                 client_session->vpp_handle, client_session_index,
+                 flags, client_session->is_nonblocking);
+
+  if (ep)
+    {
+      ep->vrf = client_session->vrf;
+      ep->is_cut_thru = client_session->is_cut_thru;
+      ep->is_ip4 = client_session->peer_addr.is_ip4;
+      ep->port = client_session->peer_port;
+      if (client_session->peer_addr.is_ip4)
+       clib_memcpy (ep->ip, &client_session->peer_addr.ip46.ip4,
+                    sizeof (ip4_address_t));
+      else
+       clib_memcpy (ep->ip, &client_session->peer_addr.ip46.ip6,
+                    sizeof (ip6_address_t));
+    }
+
+  if (client_session->is_server && client_session->is_cut_thru)
+    {
+      static svm_fifo_segment_create_args_t _a;
+      svm_fifo_segment_create_args_t *a = &_a;
+      svm_fifo_segment_private_t *seg;
+
+      cut_thru_str = " cut-thru ";
+
+      /* Create the segment */
+      memset (a, 0, sizeof (*a));
+      a->segment_name = (char *)
+       format ((u8 *) a->segment_name, "%d:segment%d%c",
+               getpid (), 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))
+       {
+         clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                       "client sid %u svm_fifo_segment_create ('%s') "
+                       "failed! rv %d", getpid (), listen_vpp_handle,
+                       listen_session_index, client_session_index,
+                       a->segment_name, rv);
+         vec_reset_length (a->new_segment_indices);
+         rv = VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+         vppcom_send_connect_session_reply (client_session,
+                                            client_session_index,
+                                            client_session->vpp_handle,
+                                            client_session->client_context,
+                                            rv);
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+         rv = VPPCOM_ENOMEM;
+         goto done;
+       }
+
+      client_session->segment_name = vec_dup ((u8 *) a->segment_name);
+      client_session->sm_seg_index = a->new_segment_indices[0];
+      vec_free (a->new_segment_indices);
+
+      seg = svm_fifo_segment_get_segment (client_session->sm_seg_index);
+      client_session->server_rx_fifo =
+       svm_fifo_segment_alloc_fifo (seg, vcm->cfg.rx_fifo_size,
+                                    FIFO_SEGMENT_RX_FREELIST);
+      if (PREDICT_FALSE (!client_session->server_rx_fifo))
+       {
+         svm_fifo_segment_delete (seg);
+         clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                       "client sid %u rx fifo alloc failed! "
+                       "size %ld (0x%lx)", getpid (), listen_vpp_handle,
+                       listen_session_index, client_session_index,
+                       vcm->cfg.rx_fifo_size, vcm->cfg.rx_fifo_size);
+         rv = VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+         vppcom_send_connect_session_reply (client_session,
+                                            client_session_index,
+                                            client_session->vpp_handle,
+                                            client_session->client_context,
+                                            rv);
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+         rv = VPPCOM_ENOMEM;
+         goto done;
+       }
+      client_session->server_rx_fifo->master_session_index =
+       client_session_index;
+
+      client_session->server_tx_fifo =
+       svm_fifo_segment_alloc_fifo (seg, vcm->cfg.tx_fifo_size,
+                                    FIFO_SEGMENT_TX_FREELIST);
+      if (PREDICT_FALSE (!client_session->server_tx_fifo))
+       {
+         svm_fifo_segment_delete (seg);
+         clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                       "client sid %u tx fifo alloc failed! "
+                       "size %ld (0x%lx)", getpid (), listen_vpp_handle,
+                       listen_session_index, client_session_index,
+                       vcm->cfg.tx_fifo_size, vcm->cfg.tx_fifo_size);
+         rv = VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
+         vppcom_send_connect_session_reply (client_session,
+                                            client_session_index,
+                                            client_session->vpp_handle,
+                                            client_session->client_context,
+                                            rv);
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+         rv = VPPCOM_ENOMEM;
+         goto done;
+       }
+      client_session->server_tx_fifo->master_session_index =
+       client_session_index;
+
+      if (VPPCOM_DEBUG > 1)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: client sid %u "
+                     "created segment '%s', rx_fifo %p, tx_fifo %p",
+                     getpid (), listen_vpp_handle, listen_session_index,
+                     client_session_index, client_session->segment_name,
+                     client_session->server_rx_fifo,
+                     client_session->server_tx_fifo);
+
+#ifdef CUT_THRU_EVENT_QUEUE    /* TBD */
+      {
+       void *oldheap;
+       ssvm_shared_header_t *sh = seg->ssvm.sh;
+
+       ssvm_lock_non_recursive (sh, 1);
+       oldheap = ssvm_push_heap (sh);
+       event_q = client_session->vpp_event_queue =
+         svm_queue_init (vcm->cfg.event_queue_size,
+                         sizeof (session_fifo_event_t),
+                         getpid (), 0 /* signal not sent */ );
+       ssvm_pop_heap (oldheap);
+       ssvm_unlock_non_recursive (sh);
+      }
+#endif
+      vppcom_send_connect_session_reply (client_session,
+                                        client_session_index,
+                                        client_session->vpp_handle,
+                                        client_session->client_context,
+                                        0 /* retval OK */ );
+    }
   else
-    clib_memcpy (ep->ip, &client_session->peer_addr.ip46.ip6,
-                sizeof (ip6_address_t));
+    {
+      cut_thru_str = " ";
+      vppcom_send_accept_session_reply (client_session->vpp_handle,
+                                       client_session->client_context,
+                                       0 /* retval OK */ );
+    }
+
+  if (VPPCOM_DEBUG > 0)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: accepted vpp handle "
+                 "0x%llx, sid %u%sconnection to local %s address "
+                 "%U port %u", getpid (), listen_vpp_handle,
+                 listen_session_index, client_session->vpp_handle,
+                 client_session_index, cut_thru_str,
+                 client_session->lcl_addr.is_ip4 ? "IPv4" : "IPv6",
+                 format_ip46_address, &client_session->lcl_addr.ip46,
+                 client_session->lcl_addr.is_ip4,
+                 clib_net_to_host_u16 (client_session->lcl_port));
+
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d, accepted peer address %U peer port %u",
-                 vcm->my_pid, client_session_index, format_ip46_address,
-                 &client_session->peer_addr.ip46,
-                 client_session->peer_addr.is_ip4,
-                 clib_net_to_host_u16 (client_session->peer_port));
+    {
+      client_session->elog_track.name =
+       (char *) format (0, "C:%d:S:%d%c", vcm->my_client_index,
+                        client_session_index, 0);
+      elog_track_register (&vcm->elog_main, &client_session->elog_track);
+
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "accept cut-thru: listen_handle:%x from_handle:%x",
+       .format_args = "i8i8",
+      };
+
+      struct
+      {
+       u64 handle[2];
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, client_session->elog_track);
+      ed->handle[0] = listen_vpp_handle;
+      ed->handle[1] = client_session->vpp_handle;
+      /* *INDENT-ON* */
+
+      if (client_session->lcl_addr.is_ip4)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e2) =
+         {
+           .format = "accept cut-thru: S:%d %d.%d.%d.%d:%d ",
+           .format_args = "i4i1i1i1i1i2",
+         };
+
+         CLIB_PACKED (struct {
+           u32 session;
+           u8 addr[4];
+           u16 port;
+         }) * ed2;
+
+         ed2 =
+           ELOG_TRACK_DATA (&vcm->elog_main, e2, client_session->elog_track);
+         ed2->session = client_session_index;
+         ed2->addr[0] = client_session->lcl_addr.ip46.ip4.as_u8[0];
+         ed2->addr[1] = client_session->lcl_addr.ip46.ip4.as_u8[1];
+         ed2->addr[2] = client_session->lcl_addr.ip46.ip4.as_u8[2];
+         ed2->addr[3] = client_session->lcl_addr.ip46.ip4.as_u8[3];
+         ed2->port = clib_net_to_host_u16 (client_session->lcl_port);
+         /* *INDENT-ON* */
+       }
+    }
+
   clib_spinlock_unlock (&vcm->sessions_lockp);
-  return (int) client_session_index;
+  rv = (int) client_session_index;
+done:
+  return rv;
 }
 
 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;
+  int rv, retval = VPPCOM_OK;
+  u64 vpp_handle = ~0;
 
-  clib_spinlock_lock (&vcm->sessions_lockp);
-  rv = vppcom_session_at_index (session_index, &session);
-  if (PREDICT_FALSE (rv))
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+
+  if (PREDICT_FALSE (session->is_vep))
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      return rv;
+      clib_warning ("VCL<%d>: ERROR: sid %u: cannot "
+                   "connect on an epoll session!", getpid (), session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
-  if (session->is_vep)
+  vpp_handle = session->vpp_handle;
+  if (PREDICT_FALSE (session->is_server))
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: is in use "
+                   "as a server session!", getpid (), vpp_handle,
+                   session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
-  if (session->state == STATE_CONNECT)
+  if (PREDICT_FALSE (session->state & CLIENT_STATE_OPEN))
     {
-      clib_spinlock_unlock (&vcm->sessions_lockp);
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] session, sid (%u) already connected!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_OK;
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: session already "
+                     "connected to %s %U port %d proto %s, state 0x%x (%s)",
+                     getpid (), vpp_handle, session_index,
+                     session->peer_addr.is_ip4 ? "IPv4" : "IPv6",
+                     format_ip46_address,
+                     &session->peer_addr.ip46, session->peer_addr.is_ip4,
+                     clib_net_to_host_u16 (session->peer_port),
+                     session->proto ? "UDP" : "TCP", session->state,
+                     vppcom_session_state_str (session->state));
+
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      goto done;
     }
 
   session->vrf = server_ep->vrf;
@@ -2322,82 +3056,94 @@ vppcom_session_connect (uint32_t session_index, vppcom_endpt_t * server_ep)
   session->peer_port = server_ep->port;
 
   if (VPPCOM_DEBUG > 0)
-    {
-      u8 *ip_str = format (0, "%U", format_ip46_address,
-                          &session->peer_addr.ip46,
-                          session->peer_addr.is_ip4);
-      clib_warning ("[%d] connect sid %d to %s server port %d proto %s",
-                   vcm->my_pid, session_index, ip_str,
-                   clib_net_to_host_u16 (session->peer_port),
-                   session->proto ? "UDP" : "TCP");
-      vec_free (ip_str);
-    }
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: connecting to server "
+                 "%s %U port %d proto %s",
+                 getpid (), vpp_handle, session_index,
+                 session->peer_addr.is_ip4 ? "IPv4" : "IPv6",
+                 format_ip46_address,
+                 &session->peer_addr.ip46, session->peer_addr.is_ip4,
+                 clib_net_to_host_u16 (session->peer_port),
+                 session->proto ? "UDP" : "TCP");
 
   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))
+
+  retval =
+    vppcom_wait_for_session_state_change (session_index, STATE_CONNECT,
+                                         vcm->cfg.session_timeout);
+
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
+  vpp_handle = session->vpp_handle;
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+done:
+  if (PREDICT_FALSE (retval))
     {
+      rv = retval;
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] connect timed out, rv = %s (%d)",
-                     vcm->my_pid, vppcom_retval_str (rv), rv);
-      return rv;
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: connect failed! "
+                     "returning %d (%s)", getpid (), vpp_handle,
+                     session_index, rv, vppcom_retval_str (rv));
     }
-  if (VPPCOM_DEBUG > 0)
-    clib_warning ("[%d] sid %d connected!", vcm->my_pid, session_index);
+  else if (VPPCOM_DEBUG > 0)
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: connected!",
+                 getpid (), vpp_handle, session_index);
 
-  return VPPCOM_OK;
+  return rv;
 }
 
 static inline int
 vppcom_session_read_internal (uint32_t session_index, void *buf, int n,
                              u8 peek)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *session = 0;
   svm_fifo_t *rx_fifo;
   int n_read = 0;
   int rv;
   char *fifo_str;
   u32 poll_et;
+  session_state_t state;
+  u8 is_server;
+  u8 is_nonblocking;
+  u64 vpp_handle;
 
   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 (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      return rv;
-    }
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
 
-  if (session->is_vep)
+  if (PREDICT_FALSE (session->is_vep))
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: ERROR: sid %u: cannot "
+                   "read from an epoll session!", getpid (), session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
-  if (session->state == STATE_DISCONNECT)
+  vpp_handle = session->vpp_handle;
+  is_server = session->is_server;
+  is_nonblocking = session->is_nonblocking;
+  state = session->state;
+  if (PREDICT_FALSE (!(state & (SERVER_STATE_OPEN | CLIENT_STATE_OPEN))))
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
+      rv = ((state == STATE_DISCONNECT) ?
+           VPPCOM_ECONNRESET : VPPCOM_ENOTCONN);
+
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] sid (%u) has been closed by remote peer!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_ECONNRESET;
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: %s session is "
+                     "not open! state 0x%x (%s), returning %d (%s)",
+                     getpid (), vpp_handle, session_index,
+                     is_server ? "server" : "client", state,
+                     vppcom_session_state_str (state),
+                     rv, vppcom_retval_str (rv));
+      goto done;
     }
 
-  rx_fifo = ((!session->is_cut_thru || session->is_server) ?
+  rx_fifo = ((!session->is_cut_thru || is_server) ?
             session->server_rx_fifo : session->server_tx_fifo);
-  fifo_str = ((!session->is_cut_thru || session->is_server) ?
+  fifo_str = ((!session->is_cut_thru || is_server) ?
              "server_rx_fifo" : "server_tx_fifo");
-  poll_et = EPOLLET & session->vep.ev.events;
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   do
@@ -2407,24 +3153,61 @@ vppcom_session_read_internal (uint32_t session_index, void *buf, int n,
       else
        n_read = svm_fifo_dequeue_nowait (rx_fifo, n, buf);
     }
-  while (!session->is_nonblocking && (n_read <= 0));
+  while (!is_nonblocking && (n_read <= 0));
 
-  if (poll_et && (n_read <= 0))
+  if (n_read <= 0)
     {
-      clib_spinlock_lock (&vcm->sessions_lockp);
-      session->vep.et_mask |= EPOLLIN;
+      VCL_LOCK_AND_GET_SESSION (session_index, &session);
+
+      poll_et = (((EPOLLET | EPOLLIN) & session->vep.ev.events) ==
+                (EPOLLET | EPOLLIN));
+      if (poll_et)
+       session->vep.et_mask |= EPOLLIN;
+
+      if (state == STATE_CLOSE_ON_EMPTY)
+       {
+         session_state_t new_state = STATE_DISCONNECT;
+         rv = VPPCOM_ECONNRESET;
+
+         if (VPPCOM_DEBUG > 1)
+           {
+             clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: Empty fifo "
+                           "with %s session state 0x%x (%s)!"
+                           "  Setting state to 0x%x (%s), returning %d (%s)",
+                           getpid (), vpp_handle, session_index,
+                           is_server ? "server" : "client",
+                           state, vppcom_session_state_str (state),
+                           new_state, vppcom_session_state_str (new_state),
+                           rv, vppcom_retval_str (rv));
+           }
+
+         session->state = new_state;
+       }
+      else
+       rv = VPPCOM_EAGAIN;
+
       clib_spinlock_unlock (&vcm->sessions_lockp);
     }
+  else
+    rv = n_read;
 
-  if ((VPPCOM_DEBUG > 2) && (n_read > 0))
-    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 <= 0) ? VPPCOM_EAGAIN : n_read;
+  if (VPPCOM_DEBUG > 2)
+    {
+      if (rv > 0)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: read %d bytes "
+                     "from %s (%p)", getpid (), vpp_handle,
+                     session_index, n_read, fifo_str, rx_fifo);
+      else
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: nothing read! "
+                     "returning %d (%s)", getpid (), vpp_handle,
+                     session_index, rv, vppcom_retval_str (rv));
+    }
+done:
+  return rv;
 }
 
 int
-vppcom_session_read (uint32_t session_index, void *buf, int n)
+vppcom_session_read (uint32_t session_index, void *buf, size_t n)
 {
   return (vppcom_session_read_internal (session_index, buf, n, 0));
 }
@@ -2438,171 +3221,268 @@ vppcom_session_peek (uint32_t session_index, void *buf, int n)
 static inline int
 vppcom_session_read_ready (session_t * session, u32 session_index)
 {
-  vppcom_main_t *vcm = &vppcom_main;
-  svm_fifo_t *rx_fifo;
+  svm_fifo_t *rx_fifo = 0;
   int ready = 0;
+  u32 poll_et;
+  int rv;
+  u8 is_server = session->is_server;
+  session_state_t state = session->state;
+  u64 vpp_handle = session->vpp_handle;
 
   /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
-  if (session->is_vep)
-    {
-      clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
-    }
-
-  if (session->state == STATE_DISCONNECT)
+  if (PREDICT_FALSE (session->is_vep))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] sid (%u) has been closed by remote peer!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_ECONNRESET;
+      clib_warning ("VCL<%d>: ERROR: sid %u: cannot read from an "
+                   "epoll session!", getpid (), session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
   if (session->is_listen)
     ready = clib_fifo_elts (vcm->client_session_index_fifo);
   else
     {
-      rx_fifo = ((!session->is_cut_thru || session->is_server) ?
+      if (!(state & (SERVER_STATE_OPEN | CLIENT_STATE_OPEN | STATE_LISTEN)))
+       {
+         rv = ((state == STATE_DISCONNECT) ? VPPCOM_ECONNRESET :
+               VPPCOM_ENOTCONN);
+
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: %s session is "
+                         "not open! state 0x%x (%s), returning %d (%s)",
+                         getpid (), vpp_handle, session_index,
+                         is_server ? "server" : "client",
+                         state, vppcom_session_state_str (state),
+                         rv, vppcom_retval_str (rv));
+         goto done;
+       }
+
+      rx_fifo = ((!session->is_cut_thru || is_server) ?
                 session->server_rx_fifo : session->server_tx_fifo);
 
       ready = svm_fifo_max_dequeue (rx_fifo);
     }
 
-  if (VPPCOM_DEBUG > 3)
-    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);
-  if ((session->vep.ev.events & EPOLLET) && (ready == 0))
-    session->vep.et_mask |= EPOLLIN;
+  if (ready == 0)
+    {
+      poll_et =
+       ((EPOLLET | EPOLLIN) & session->vep.ev.events) == (EPOLLET | EPOLLIN);
+      if (poll_et)
+       session->vep.et_mask |= EPOLLIN;
 
-  return ready;
-}
+      if (state == STATE_CLOSE_ON_EMPTY)
+       {
+         rv = VPPCOM_ECONNRESET;
+         session_state_t new_state = STATE_DISCONNECT;
 
-int
-vppcom_session_write (uint32_t session_index, void *buf, int n)
-{
-  vppcom_main_t *vcm = &vppcom_main;
-  session_t *session = 0;
+         if (VPPCOM_DEBUG > 1)
+           {
+             clib_warning ("VCL<%d>: vpp handle 0x%llx, "
+                           "sid %u: Empty fifo with"
+                           " %s session state 0x%x (%s)! Setting state to "
+                           "0x%x (%s), returning %d (%s)",
+                           getpid (), session_index, vpp_handle,
+                           is_server ? "server" : "client",
+                           state, vppcom_session_state_str (state),
+                           new_state, vppcom_session_state_str (new_state),
+                           rv, vppcom_retval_str (rv));
+           }
+         session->state = new_state;
+         goto done;
+       }
+    }
+  rv = ready;
+
+  if (vcm->app_event_queue->cursize &&
+      !pthread_mutex_trylock (&vcm->app_event_queue->mutex))
+    {
+      u32 i, n_to_dequeue = vcm->app_event_queue->cursize;
+      session_fifo_event_t e;
+
+      for (i = 0; i < n_to_dequeue; i++)
+       svm_queue_sub_raw (vcm->app_event_queue, (u8 *) & e);
+
+      pthread_mutex_unlock (&vcm->app_event_queue->mutex);
+    }
+done:
+  return rv;
+}
+
+int
+vppcom_session_write (uint32_t session_index, void *buf, size_t n)
+{
+  session_t *session = 0;
   svm_fifo_t *tx_fifo;
-  unix_shared_memory_queue_t *q;
+  svm_queue_t *q;
   session_fifo_event_t evt;
   int rv, n_write;
   char *fifo_str;
   u32 poll_et;
+  u8 is_server;
+  u8 is_nonblocking;
+  session_state_t state;
+  u64 vpp_handle;
 
   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 (%u) has been closed!",
-                     vcm->my_pid, session_index);
-      return rv;
-    }
+  VCL_LOCK_AND_GET_SESSION (session_index, &session);
 
-  if (session->is_vep)
+  if (PREDICT_FALSE (session->is_vep))
     {
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "cannot write to an epoll session!",
+                   getpid (), session->vpp_handle, session_index);
+
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
-  if (session->state == STATE_DISCONNECT)
+  is_server = session->is_server;
+  is_nonblocking = session->is_nonblocking;
+  vpp_handle = session->vpp_handle;
+  state = session->state;
+  if (!(state & (SERVER_STATE_OPEN | CLIENT_STATE_OPEN)))
     {
+      rv = ((state == STATE_DISCONNECT) ? VPPCOM_ECONNRESET :
+           VPPCOM_ENOTCONN);
+
       clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] sid (%u) has been closed by remote peer!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_ECONNRESET;
+      if (VPPCOM_DEBUG > 1)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "%s session is not open! state 0x%x (%s)",
+                     getpid (), vpp_handle, session_index,
+                     is_server ? "server" : "client", state,
+                     vppcom_session_state_str (state));
+      goto done;
     }
 
-  tx_fifo = ((!session->is_cut_thru || session->is_server) ?
+  tx_fifo = ((!session->is_cut_thru || is_server) ?
             session->server_tx_fifo : session->server_rx_fifo);
-  fifo_str = ((!session->is_cut_thru || session->is_server) ?
+  fifo_str = ((!session->is_cut_thru || is_server) ?
              "server_tx_fifo" : "server_rx_fifo");
-  q = session->vpp_event_queue;
-  poll_et = EPOLLET & session->vep.ev.events;
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   do
     {
-      n_write = svm_fifo_enqueue_nowait (tx_fifo, n, buf);
+      n_write = svm_fifo_enqueue_nowait (tx_fifo, n, (void *) buf);
     }
-  while (!session->is_nonblocking && (n_write <= 0));
+  while (!is_nonblocking && (n_write <= 0));
 
   /* If event wasn't set, add one */
   if (!session->is_cut_thru && (n_write > 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;
 
-      rval = vppcom_session_at_index (session_index, &session);
-      if (PREDICT_FALSE (rval))
-       {
-         if (VPPCOM_DEBUG > 1)
-           clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                         vcm->my_pid, session_index);
-         return rval;
-       }
+      VCL_LOCK_AND_GET_SESSION (session_index, &session);
+      q = session->vpp_event_queue;
       ASSERT (q);
-      unix_shared_memory_queue_add (q, (u8 *) & evt,
-                                   0 /* do wait for mutex */ );
+      svm_queue_add (q, (u8 *) & evt, 0 /* do wait for mutex */ );
+      clib_spinlock_unlock (&vcm->sessions_lockp);
+      if (VPPCOM_DEBUG > 1)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "added FIFO_EVENT_APP_TX to "
+                     "vpp_event_q %p, n_write %d", getpid (),
+                     vpp_handle, session_index, q, n_write);
     }
 
-  if (poll_et && (n_write <= 0))
+  if (n_write <= 0)
     {
-      clib_spinlock_lock (&vcm->sessions_lockp);
-      session->vep.et_mask |= EPOLLOUT;
+      VCL_LOCK_AND_GET_SESSION (session_index, &session);
+
+      poll_et = (((EPOLLET | EPOLLOUT) & session->vep.ev.events) ==
+                (EPOLLET | EPOLLOUT));
+      if (poll_et)
+       session->vep.et_mask |= EPOLLOUT;
+
+      if (state == STATE_CLOSE_ON_EMPTY)
+       {
+         session_state_t new_state = STATE_DISCONNECT;
+         rv = VPPCOM_ECONNRESET;
+
+         if (VPPCOM_DEBUG > 1)
+           {
+             clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                           "Empty fifo with %s session state 0x%x (%s)!"
+                           "  Setting state to 0x%x (%s), returning %d (%s)",
+                           getpid (), vpp_handle, session_index,
+                           is_server ? "server" : "client",
+                           state, vppcom_session_state_str (state),
+                           new_state, vppcom_session_state_str (new_state),
+                           rv, vppcom_retval_str (rv));
+           }
+
+         session->state = new_state;
+       }
+      else
+       rv = VPPCOM_EAGAIN;
+
       clib_spinlock_unlock (&vcm->sessions_lockp);
     }
+  else
+    rv = n_write;
 
   if (VPPCOM_DEBUG > 2)
     {
-      if (n_write == -2)
-       clib_warning ("[%d] sid %d, FIFO-FULL %s (%p)", vcm->my_pid,
+      if (n_write <= 0)
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "FIFO-FULL %s (%p)", getpid (), vpp_handle,
                      session_index, fifo_str, tx_fifo);
       else
-       clib_warning ("[%d] sid %d, wrote %d bytes to %s (%p)", vcm->my_pid,
+       clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                     "wrote %d bytes to %s (%p)", getpid (), vpp_handle,
                      session_index, n_write, fifo_str, tx_fifo);
     }
-  return (n_write < 0) ? VPPCOM_EAGAIN : n_write;
+done:
+  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;
   char *fifo_str;
   int ready;
+  u32 poll_et;
+  int rv;
+  u8 is_server = session->is_server;
+  session_state_t state = session->state;
 
   /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
-  if (session->is_vep)
+  if (PREDICT_FALSE (session->is_vep))
     {
-      clib_spinlock_unlock (&vcm->sessions_lockp);
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] invalid session, sid (%u) is an epoll session!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_EBADFD;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "cannot write to an epoll session!",
+                   getpid (), session->vpp_handle, session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
     }
 
-  if (session->state == STATE_DISCONNECT)
+  if (PREDICT_FALSE (session->is_listen))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("[%d] sid (%u) has been closed by remote peer!",
-                     vcm->my_pid, session_index);
-      return VPPCOM_ECONNRESET;
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "cannot write to a listen session!",
+                   getpid (), session->vpp_handle, session_index);
+      rv = VPPCOM_EBADFD;
+      goto done;
+    }
+
+  if (!(state & (SERVER_STATE_OPEN | CLIENT_STATE_OPEN)))
+    {
+      session_state_t state = session->state;
+
+      rv = ((state == STATE_DISCONNECT) ? VPPCOM_ECONNRESET :
+           VPPCOM_ENOTCONN);
+
+      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
+                   "%s session is not open! state 0x%x (%s), "
+                   "returning %d (%s)", getpid (), session->vpp_handle,
+                   session_index, is_server ? "server" : "client",
+                   state, vppcom_session_state_str (state),
+                   rv, vppcom_retval_str (rv));
+      goto done;
     }
 
   tx_fifo = ((!session->is_cut_thru || session->is_server) ?
@@ -2613,12 +3493,42 @@ vppcom_session_write_ready (session_t * session, u32 session_index)
   ready = svm_fifo_max_enqueue (tx_fifo);
 
   if (VPPCOM_DEBUG > 3)
-    clib_warning ("[%d] sid %d, peek %s (%p), ready = %d", vcm->my_pid,
-                 session_index, fifo_str, tx_fifo, ready);
-  if ((session->vep.ev.events & EPOLLET) && (ready == 0))
-    session->vep.et_mask |= EPOLLOUT;
+    clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                 "peek %s (%p), ready = %d", getpid (),
+                 session->vpp_handle, session_index,
+                 fifo_str, tx_fifo, ready);
 
-  return ready;
+  if (ready == 0)
+    {
+      poll_et = (((EPOLLET | EPOLLOUT) & session->vep.ev.events) ==
+                (EPOLLET | EPOLLOUT));
+      if (poll_et)
+       session->vep.et_mask |= EPOLLOUT;
+
+      if (state == STATE_CLOSE_ON_EMPTY)
+       {
+         rv = VPPCOM_ECONNRESET;
+         session_state_t new_state = STATE_DISCONNECT;
+
+         if (VPPCOM_DEBUG > 1)
+           {
+             clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: "
+                           "Empty fifo with %s session "
+                           "state 0x%x (%s)! Setting state to 0x%x (%s), "
+                           "returning %d (%s)", getpid (),
+                           session->vpp_handle, session_index,
+                           is_server ? "server" : "client",
+                           state, vppcom_session_state_str (state),
+                           new_state, vppcom_session_state_str (new_state),
+                           rv, vppcom_retval_str (rv));
+           }
+         session->state = new_state;
+         goto done;
+       }
+    }
+  rv = ready;
+done:
+  return rv;
 }
 
 int
@@ -2626,7 +3536,6 @@ 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;
@@ -2638,20 +3547,25 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
   if (n_bits && 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));
+      clib_memcpy (vcm->rd_bitmap, read_map,
+                  vec_len (vcm->rd_bitmap) * sizeof (clib_bitmap_t));
+      memset (read_map, 0, vec_len (vcm->rd_bitmap) * sizeof (clib_bitmap_t));
     }
   if (n_bits && 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));
+      clib_memcpy (vcm->wr_bitmap, write_map,
+                  vec_len (vcm->wr_bitmap) * sizeof (clib_bitmap_t));
+      memset (write_map, 0,
+             vec_len (vcm->wr_bitmap) * sizeof (clib_bitmap_t));
     }
   if (n_bits && 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));
+      clib_memcpy (vcm->ex_bitmap, except_map,
+                  vec_len (vcm->ex_bitmap) * sizeof (clib_bitmap_t));
+      memset (except_map, 0,
+             vec_len (vcm->ex_bitmap) * sizeof (clib_bitmap_t));
     }
 
   do
@@ -2669,8 +3583,8 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                     {
                       clib_spinlock_unlock (&vcm->sessions_lockp);
                       if (VPPCOM_DEBUG > 1)
-                        clib_warning ("[%d] session %d specified in "
-                                      "read_map is closed.", vcm->my_pid,
+                        clib_warning ("VCL<%d>: session %d specified in "
+                                      "read_map is closed.", getpid (),
                                       session_index);
                       bits_set = VPPCOM_EBADFD;
                       goto select_done;
@@ -2682,13 +3596,11 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                       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++;
                     }
@@ -2705,8 +3617,8 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                     {
                       clib_spinlock_unlock (&vcm->sessions_lockp);
                       if (VPPCOM_DEBUG > 0)
-                        clib_warning ("[%d] session %d specified in "
-                                      "write_map is closed.", vcm->my_pid,
+                        clib_warning ("VCL<%d>: session %d specified in "
+                                      "write_map is closed.", getpid (),
                                       session_index);
                       bits_set = VPPCOM_EBADFD;
                       goto select_done;
@@ -2716,7 +3628,6 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                   clib_spinlock_unlock (&vcm->sessions_lockp);
                   if (write_map && (rv > 0))
                     {
-                      // TBD: clib_warning
                       clib_bitmap_set_no_check (write_map, session_index, 1);
                       bits_set++;
                     }
@@ -2733,8 +3644,8 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                     {
                       clib_spinlock_unlock (&vcm->sessions_lockp);
                       if (VPPCOM_DEBUG > 1)
-                        clib_warning ("[%d] session %d specified in "
-                                      "except_map is closed.", vcm->my_pid,
+                        clib_warning ("VCL<%d>: session %d specified in "
+                                      "except_map is closed.", getpid (),
                                       session_index);
                       bits_set = VPPCOM_EBADFD;
                       goto select_done;
@@ -2744,7 +3655,6 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                   clib_spinlock_unlock (&vcm->sessions_lockp);
                   if (rv < 0)
                     {
-                      // TBD: clib_warning
                       clib_bitmap_set_no_check (except_map, session_index, 1);
                       bits_set++;
                     }
@@ -2753,7 +3663,7 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
         }
       /* *INDENT-ON* */
     }
-  while (clib_time_now (&vcm->clib_time) < timeout);
+  while ((time_to_wait == -1) || (clib_time_now (&vcm->clib_time) < timeout));
 
 select_done:
   return (bits_set);
@@ -2765,86 +3675,86 @@ vep_verify_epoll_chain (u32 vep_idx)
   session_t *session;
   vppcom_epoll_t *vep;
   int rv;
-  u32 sid;
+  u32 sid = vep_idx;
 
-  if (VPPCOM_DEBUG < 1)
+  if (VPPCOM_DEBUG <= 1)
     return;
 
   /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
   rv = vppcom_session_at_index (vep_idx, &session);
   if (PREDICT_FALSE (rv))
     {
-      clib_warning ("ERROR: Invalid vep_idx (%u)!", vep_idx);
+      clib_warning ("VCL<%d>: ERROR: Invalid vep_idx (%u)!",
+                   getpid (), vep_idx);
       goto done;
     }
   if (PREDICT_FALSE (!session->is_vep))
     {
-      clib_warning ("ERROR: vep_idx (%u) is not a vep!", vep_idx);
+      clib_warning ("VCL<%d>: ERROR: vep_idx (%u) is not a vep!",
+                   getpid (), vep_idx);
       goto done;
     }
-  if (VPPCOM_DEBUG > 1)
-    clib_warning ("vep_idx (%u): Dumping epoll chain\n"
-                 "{\n"
-                 "   is_vep         = %u\n"
-                 "   is_vep_session = %u\n"
-                 "   wait_cont_idx  = 0x%x (%u)\n"
-                 "}\n",
-                 vep_idx, session->is_vep, session->is_vep_session,
-                 session->wait_cont_idx, session->wait_cont_idx);
-  do
+  vep = &session->vep;
+  clib_warning ("VCL<%d>: vep_idx (%u): Dumping epoll chain\n"
+               "{\n"
+               "   is_vep         = %u\n"
+               "   is_vep_session = %u\n"
+               "   next_sid       = 0x%x (%u)\n"
+               "   wait_cont_idx  = 0x%x (%u)\n"
+               "}\n", getpid (), vep_idx,
+               session->is_vep, session->is_vep_session,
+               vep->next_sid, vep->next_sid,
+               session->wait_cont_idx, session->wait_cont_idx);
+
+  for (sid = vep->next_sid; sid != ~0; sid = vep->next_sid)
     {
+      rv = vppcom_session_at_index (sid, &session);
+      if (PREDICT_FALSE (rv))
+       {
+         clib_warning ("VCL<%d>: ERROR: Invalid sid (%u)!", getpid (), sid);
+         goto done;
+       }
+      if (PREDICT_FALSE (session->is_vep))
+       clib_warning ("VCL<%d>: ERROR: sid (%u) is a vep!",
+                     getpid (), vep_idx);
+      else if (PREDICT_FALSE (!session->is_vep_session))
+       {
+         clib_warning ("VCL<%d>: ERROR: session (%u) "
+                       "is not a vep session!", getpid (), sid);
+         goto done;
+       }
       vep = &session->vep;
-      sid = vep->next_sid;
+      if (PREDICT_FALSE (vep->vep_idx != vep_idx))
+       clib_warning ("VCL<%d>: ERROR: session (%u) vep_idx (%u) != "
+                     "vep_idx (%u)!", getpid (),
+                     sid, session->vep.vep_idx, vep_idx);
       if (session->is_vep_session)
        {
-         if (VPPCOM_DEBUG > 1)
-           clib_warning ("vep_idx[%u]: sid 0x%x (%u)\n"
-                         "{\n"
-                         "   next_sid       = 0x%x (%u)\n"
-                         "   prev_sid       = 0x%x (%u)\n"
-                         "   vep_idx        = 0x%x (%u)\n"
-                         "   ev.events      = 0x%x\n"
-                         "   ev.data.u64    = 0x%llx\n"
-                         "   et_mask        = 0x%x\n"
-                         "}\n",
-                         vep_idx, sid, sid,
-                         vep->next_sid, vep->next_sid,
-                         vep->prev_sid, vep->prev_sid,
-                         vep->vep_idx, vep->vep_idx,
-                         vep->ev.events, vep->ev.data.u64, vep->et_mask);
-       }
-      if (sid != ~0)
-       {
-         rv = vppcom_session_at_index (sid, &session);
-         if (PREDICT_FALSE (rv))
-           {
-             clib_warning ("ERROR: Invalid sid (%u)!", sid);
-             goto done;
-           }
-         if (PREDICT_FALSE (session->is_vep))
-           clib_warning ("ERROR: sid (%u) is a vep!", vep_idx);
-         else if (PREDICT_FALSE (!session->is_vep_session))
-           {
-             clib_warning ("ERROR: session (%u) is not a vep session!", sid);
-             goto done;
-           }
-         if (PREDICT_FALSE (session->vep.vep_idx != vep_idx))
-           clib_warning ("ERROR: session (%u) vep_idx (%u) != "
-                         "vep_idx (%u)!",
-                         sid, session->vep.vep_idx, vep_idx);
+         clib_warning ("vep_idx[%u]: sid 0x%x (%u)\n"
+                       "{\n"
+                       "   next_sid       = 0x%x (%u)\n"
+                       "   prev_sid       = 0x%x (%u)\n"
+                       "   vep_idx        = 0x%x (%u)\n"
+                       "   ev.events      = 0x%x\n"
+                       "   ev.data.u64    = 0x%llx\n"
+                       "   et_mask        = 0x%x\n"
+                       "}\n",
+                       vep_idx, sid, sid,
+                       vep->next_sid, vep->next_sid,
+                       vep->prev_sid, vep->prev_sid,
+                       vep->vep_idx, vep->vep_idx,
+                       vep->ev.events, vep->ev.data.u64, vep->et_mask);
        }
     }
-  while (sid != ~0);
 
 done:
-  if (VPPCOM_DEBUG > 1)
-    clib_warning ("vep_idx (%u): Dump complete!", vep_idx);
+  clib_warning ("VCL<%d>: vep_idx (%u): Dump complete!\n",
+               getpid (), vep_idx);
 }
 
 int
 vppcom_epoll_create (void)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *vep_session;
   u32 vep_idx;
 
@@ -2858,10 +3768,36 @@ vppcom_epoll_create (void)
   vep_session->vep.next_sid = ~0;
   vep_session->vep.prev_sid = ~0;
   vep_session->wait_cont_idx = ~0;
+  vep_session->vpp_handle = ~0;
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   if (VPPCOM_DEBUG > 0)
-    clib_warning ("Created vep_idx %u!", vep_idx);
+    clib_warning ("VCL<%d>: Created vep_idx %u / sid %u!",
+                 getpid (), vep_idx, vep_idx);
+
+  if (VPPCOM_DEBUG > 0)
+    {
+      vep_session->elog_track.name =
+       (char *) format (0, "C:%d:VEP:%d%c", vcm->my_client_index,
+                        vep_idx, 0);
+      elog_track_register (&vcm->elog_main, &vep_session->elog_track);
+
+      /* *INDENT-OFF* */
+      ELOG_TYPE_DECLARE (e) =
+      {
+       .format = "created epoll session:%d",
+       .format_args = "i4",
+      };
+
+      struct
+      {
+       u32 data;
+      } *ed;
+
+      ed = ELOG_TRACK_DATA (&vcm->elog_main, e, vep_session->elog_track);
+      ed->data = vep_idx;
+      /* *INDENT-ON* */
+    }
 
   return (vep_idx);
 }
@@ -2870,15 +3806,14 @@ int
 vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
                  struct epoll_event *event)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *vep_session;
   session_t *session;
   int rv;
 
   if (vep_idx == session_index)
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: vep_idx == session_index (%u)!", vep_idx);
+      clib_warning ("VCL<%d>: ERROR: vep_idx == session_index (%u)!",
+                   getpid (), vep_idx);
       return VPPCOM_EINVAL;
     }
 
@@ -2886,14 +3821,13 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
   rv = vppcom_session_at_index (vep_idx, &vep_session);
   if (PREDICT_FALSE (rv))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: Invalid vep_idx (%u)!", vep_idx);
+      clib_warning ("VCL<%d>: ERROR: Invalid vep_idx (%u)!", vep_idx);
       goto done;
     }
   if (PREDICT_FALSE (!vep_session->is_vep))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: vep_idx (%u) is not a vep!", vep_idx);
+      clib_warning ("VCL<%d>: ERROR: vep_idx (%u) is not a vep!",
+                   getpid (), vep_idx);
       rv = VPPCOM_EINVAL;
       goto done;
     }
@@ -2905,13 +3839,13 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
   if (PREDICT_FALSE (rv))
     {
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: Invalid session_index (%u)!", session_index);
+       clib_warning ("VCL<%d>: ERROR: Invalid session_index (%u)!",
+                     getpid (), session_index);
       goto done;
     }
   if (PREDICT_FALSE (session->is_vep))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: session_index (%u) is a vep!", vep_idx);
+      clib_warning ("ERROR: session_index (%u) is a vep!", vep_idx);
       rv = VPPCOM_EINVAL;
       goto done;
     }
@@ -2921,7 +3855,8 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
     case EPOLL_CTL_ADD:
       if (PREDICT_FALSE (!event))
        {
-         clib_warning ("NULL pointer to epoll_event structure!");
+         clib_warning ("VCL<%d>: ERROR: EPOLL_CTL_ADD: NULL pointer to "
+                       "epoll_event structure!", getpid ());
          rv = VPPCOM_EINVAL;
          goto done;
        }
@@ -2932,10 +3867,9 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
                                        &next_session);
          if (PREDICT_FALSE (rv))
            {
-             if (VPPCOM_DEBUG > 0)
-               clib_warning ("EPOLL_CTL_ADD: Invalid vep.next_sid (%u) on"
-                             " vep_idx (%u)!", vep_session->vep.next_sid,
-                             vep_idx);
+             clib_warning ("VCL<%d>: ERROR: EPOLL_CTL_ADD: Invalid "
+                           "vep.next_sid (%u) on vep_idx (%u)!",
+                           getpid (), vep_session->vep.next_sid, vep_idx);
              goto done;
            }
          ASSERT (next_session->vep.prev_sid == vep_idx);
@@ -2946,59 +3880,83 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
       session->vep.vep_idx = vep_idx;
       session->vep.et_mask = VEP_DEFAULT_ET_MASK;
       session->vep.ev = *event;
+      session->is_vep = 0;
       session->is_vep_session = 1;
       vep_session->vep.next_sid = session_index;
       if (VPPCOM_DEBUG > 1)
-       clib_warning ("EPOLL_CTL_ADD: vep_idx %u, sid %u, events 0x%x,"
-                     " data 0x%llx!", vep_idx, session_index,
+       clib_warning ("VCL<%d>: EPOLL_CTL_ADD: vep_idx %u, "
+                     "sid %u, events 0x%x, data 0x%llx!",
+                     getpid (), vep_idx, session_index,
                      event->events, event->data.u64);
+      if (VPPCOM_DEBUG > 0)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+           {
+             .format = "epoll_ctladd: events:%x data:%x",
+             .format_args = "i4i4i8",
+           };
+         struct
+         {
+           u32 events;
+           u64 event_data;
+         } *ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+         ed->events = event->events;
+         ed->event_data = event->data.u64;
+         /* *INDENT-ON* */
+       }
       break;
 
     case EPOLL_CTL_MOD:
       if (PREDICT_FALSE (!event))
        {
-         clib_warning ("NULL pointer to epoll_event structure!");
+         clib_warning ("VCL<%d>: ERROR: EPOLL_CTL_MOD: NULL pointer to "
+                       "epoll_event structure!", getpid ());
          rv = VPPCOM_EINVAL;
          goto done;
        }
-      if (PREDICT_FALSE (!session->is_vep_session &&
-                        (session->vep.vep_idx != vep_idx)))
+      else if (PREDICT_FALSE (!session->is_vep_session))
        {
-         if (VPPCOM_DEBUG > 0)
-           {
-             if (!session->is_vep_session)
-               clib_warning ("EPOLL_CTL_MOD: session (%u) is not "
-                             "a vep session!", session_index);
-             else
-               clib_warning ("EPOLL_CTL_MOD: session (%u) vep_idx (%u) != "
-                             "vep_idx (%u)!", session_index,
-                             session->vep.vep_idx, vep_idx);
-           }
+         clib_warning ("VCL<%d>: ERROR: sid %u EPOLL_CTL_MOD: "
+                       "not a vep session!", getpid (), session_index);
+         rv = VPPCOM_EINVAL;
+         goto done;
+       }
+      else if (PREDICT_FALSE (session->vep.vep_idx != vep_idx))
+       {
+         clib_warning ("VCL<%d>: ERROR: sid %u EPOLL_CTL_MOD: "
+                       "vep_idx (%u) != vep_idx (%u)!",
+                       getpid (), session_index,
+                       session->vep.vep_idx, vep_idx);
          rv = VPPCOM_EINVAL;
          goto done;
        }
       session->vep.et_mask = VEP_DEFAULT_ET_MASK;
       session->vep.ev = *event;
       if (VPPCOM_DEBUG > 1)
-       clib_warning ("EPOLL_CTL_MOD: vep_idx %u, sid %u, events 0x%x,"
-                     " data 0x%llx!", vep_idx, session_index,
-                     event->events, event->data.u64);
+       clib_warning
+         ("VCL<%d>: EPOLL_CTL_MOD: vep_idx %u, sid %u, events 0x%x,"
+          " data 0x%llx!", getpid (), vep_idx, session_index, event->events,
+          event->data.u64);
       break;
 
     case EPOLL_CTL_DEL:
-      if (PREDICT_FALSE (!session->is_vep_session &&
-                        (session->vep.vep_idx != vep_idx)))
+      if (PREDICT_FALSE (!session->is_vep_session))
        {
-         if (VPPCOM_DEBUG > 0)
-           {
-             if (!session->is_vep_session)
-               clib_warning ("EPOLL_CTL_DEL: session (%u) is not "
-                             "a vep session!", session_index);
-             else
-               clib_warning ("EPOLL_CTL_DEL: session (%u) vep_idx (%u) != "
-                             "vep_idx (%u)!", session_index,
-                             session->vep.vep_idx, vep_idx);
-           }
+         clib_warning ("VCL<%d>: ERROR: sid %u EPOLL_CTL_DEL: "
+                       "not a vep session!", getpid (), session_index);
+         rv = VPPCOM_EINVAL;
+         goto done;
+       }
+      else if (PREDICT_FALSE (session->vep.vep_idx != vep_idx))
+       {
+         clib_warning ("VCL<%d>: ERROR: sid %u EPOLL_CTL_DEL: "
+                       "vep_idx (%u) != vep_idx (%u)!",
+                       getpid (), session_index,
+                       session->vep.vep_idx, vep_idx);
          rv = VPPCOM_EINVAL;
          goto done;
        }
@@ -3015,10 +3973,9 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
          rv = vppcom_session_at_index (session->vep.prev_sid, &prev_session);
          if (PREDICT_FALSE (rv))
            {
-             if (VPPCOM_DEBUG > 0)
-               clib_warning ("EPOLL_CTL_DEL: Invalid vep.prev_sid (%u) on"
-                             " sid (%u)!", session->vep.prev_sid,
-                             session_index);
+             clib_warning ("VCL<%d>: ERROR: EPOLL_CTL_DEL: Invalid "
+                           "vep.prev_sid (%u) on sid (%u)!",
+                           getpid (), session->vep.prev_sid, session_index);
              goto done;
            }
          ASSERT (prev_session->vep.next_sid == session_index);
@@ -3030,10 +3987,9 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
          rv = vppcom_session_at_index (session->vep.next_sid, &next_session);
          if (PREDICT_FALSE (rv))
            {
-             if (VPPCOM_DEBUG > 0)
-               clib_warning ("EPOLL_CTL_DEL: Invalid vep.next_sid (%u) on"
-                             " sid (%u)!", session->vep.next_sid,
-                             session_index);
+             clib_warning ("VCL<%d>: ERROR: EPOLL_CTL_DEL: Invalid "
+                           "vep.next_sid (%u) on sid (%u)!",
+                           getpid (), session->vep.next_sid, session_index);
              goto done;
            }
          ASSERT (next_session->vep.prev_sid == session_index);
@@ -3046,12 +4002,30 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
       session->vep.vep_idx = ~0;
       session->is_vep_session = 0;
       if (VPPCOM_DEBUG > 1)
-       clib_warning ("EPOLL_CTL_DEL: vep_idx %u, sid %u!", vep_idx,
-                     session_index);
+       clib_warning ("VCL<%d>: EPOLL_CTL_DEL: vep_idx %u, sid %u!",
+                     getpid (), vep_idx, session_index);
+      if (VPPCOM_DEBUG > 0)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+           {
+             .format = "epoll_ctldel: vep:%d",
+             .format_args = "i4",
+           };
+         struct
+         {
+           u32 data;
+         } *ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+         ed->data = vep_idx;
+         /* *INDENT-ON* */
+       }
       break;
 
     default:
-      clib_warning ("Invalid operation (%d)!", op);
+      clib_warning ("VCL<%d>: ERROR: Invalid operation (%d)!", getpid (), op);
       rv = VPPCOM_EINVAL;
     }
 
@@ -3062,45 +4036,22 @@ done:
   return rv;
 }
 
-#define VCL_LOCK_AND_GET_SESSION(I, S)                  \
-do {                                                    \
-  vppcom_main_t *vcm = &vppcom_main;                    \
-                                                        \
-  clib_spinlock_lock (&vcm->sessions_lockp);            \
-  rv = vppcom_session_at_index (I, S);                  \
-  if (PREDICT_FALSE (rv))                               \
-    {                                                   \
-      clib_spinlock_unlock (&vcm->sessions_lockp);      \
-                                                        \
-      if (VPPCOM_DEBUG > 0)                             \
-        clib_warning ("ERROR: Invalid ##I (%u)!", I);   \
-                                                        \
-      goto done;                                        \
-    }                                                   \
-} while (0)
-
 int
 vppcom_epoll_wait (uint32_t vep_idx, struct epoll_event *events,
                   int maxevents, double wait_for_time)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *vep_session;
   int rv;
   f64 timeout = clib_time_now (&vcm->clib_time) + wait_for_time;
+  u32 keep_trying = 1;
   int num_ev = 0;
   u32 vep_next_sid, wait_cont_idx;
   u8 is_vep;
 
   if (PREDICT_FALSE (maxevents <= 0))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: Invalid maxevents (%d)!", maxevents);
-      return VPPCOM_EINVAL;
-    }
-  if (PREDICT_FALSE (wait_for_time < 0))
-    {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: Invalid wait_for_time (%f)!", wait_for_time);
+      clib_warning ("VCL<%d>: ERROR: Invalid maxevents (%d)!",
+                   getpid (), maxevents);
       return VPPCOM_EINVAL;
     }
   memset (events, 0, sizeof (*events) * maxevents);
@@ -3113,14 +4064,34 @@ vppcom_epoll_wait (uint32_t vep_idx, struct epoll_event *events,
 
   if (PREDICT_FALSE (!is_vep))
     {
-      if (VPPCOM_DEBUG > 0)
-       clib_warning ("ERROR: vep_idx (%u) is not a vep!", vep_idx);
+      clib_warning ("VCL<%d>: ERROR: vep_idx (%u) is not a vep!",
+                   getpid (), vep_idx);
       rv = VPPCOM_EINVAL;
       goto done;
     }
-  if ((VPPCOM_DEBUG > 0) && (PREDICT_FALSE (vep_next_sid == ~0)))
+  if (PREDICT_FALSE (vep_next_sid == ~0))
     {
-      clib_warning ("WARNING: vep_idx (%u) is empty!", vep_idx);
+      if (VPPCOM_DEBUG > 0)
+       clib_warning ("VCL<%d>: WARNING: vep_idx (%u) is empty!",
+                     getpid (), vep_idx);
+      if (VPPCOM_DEBUG > 0)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+           {
+             .format = "WRN: vep_idx:%d empty",
+             .format_args = "i4",
+           };
+         struct
+         {
+           u32 data;
+         } *ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, vep_session->elog_track);
+
+         ed->data = vep_idx;
+         /* *INDENT-ON* */
+       }
       goto done;
     }
 
@@ -3151,39 +4122,79 @@ vppcom_epoll_wait (uint32_t vep_idx, struct epoll_event *events,
          if (PREDICT_FALSE (is_vep))
            {
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("ERROR: sid (%u) is a vep!", vep_idx);
+               clib_warning ("VCL<%d>: ERROR: sid (%u) is a vep!",
+                             getpid (), vep_idx);
+             if (VPPCOM_DEBUG > 0)
+               {
+                 /* *INDENT-OFF* */
+                 ELOG_TYPE_DECLARE (e) =
+                   {
+                     .format = "ERR:vep_idx:%d is vep",
+                     .format_args = "i4",
+                   };
+                 struct
+                 {
+                   u32 data;
+                 } *ed;
+
+                 ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+                 ed->data = vep_idx;
+                 /* *INDENT-ON* */
+               }
+
              rv = VPPCOM_EINVAL;
              goto done;
            }
          if (PREDICT_FALSE (!is_vep_session))
            {
              if (VPPCOM_DEBUG > 0)
-               clib_warning ("EPOLL_CTL_MOD: session (%u) is not "
-                             "a vep session!", sid);
+               clib_warning ("VCL<%d>: ERROR: session (%u) is not "
+                             "a vep session!", getpid (), sid);
+             if (VPPCOM_DEBUG > 0)
+               {
+                 /* *INDENT-OFF* */
+                 ELOG_TYPE_DECLARE (e) =
+                   {
+                     .format = "ERR:SID:%d not vep",
+                     .format_args = "i4",
+                   };
+                 struct
+                 {
+                   u32 data;
+                 } *ed;
+
+                 ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+                 ed->data = sid;
+                 /* *INDENT-ON* */
+               }
+
              rv = VPPCOM_EINVAL;
              goto done;
            }
          if (PREDICT_FALSE (session_vep_idx != vep_idx))
            {
-             clib_warning ("EPOLL_CTL_MOD: session (%u) "
+             clib_warning ("VCL<%d>: ERROR: session (%u) "
                            "vep_idx (%u) != vep_idx (%u)!",
-                           sid, session->vep.vep_idx, vep_idx);
+                           getpid (), sid, session->vep.vep_idx, vep_idx);
              rv = VPPCOM_EINVAL;
              goto done;
            }
 
          add_event = clear_et_mask = 0;
 
-         if ((EPOLLIN & session_events) && (EPOLLIN & et_mask))
+         if (EPOLLIN & session_events)
            {
              VCL_LOCK_AND_GET_SESSION (sid, &session);
              ready = vppcom_session_read_ready (session, sid);
              clib_spinlock_unlock (&vcm->sessions_lockp);
-             if (ready > 0)
+             if ((ready > 0) && (EPOLLIN & et_mask))
                {
                  add_event = 1;
                  events[num_ev].events |= EPOLLIN;
-                 if (EPOLLET & session_events)
+                 if (((EPOLLET | EPOLLIN) & session_events) ==
+                     (EPOLLET | EPOLLIN))
                    clear_et_mask |= EPOLLIN;
                }
              else if (ready < 0)
@@ -3202,16 +4213,17 @@ vppcom_epoll_wait (uint32_t vep_idx, struct epoll_event *events,
                }
            }
 
-         if ((EPOLLOUT & session_events) && (EPOLLOUT & et_mask))
+         if (EPOLLOUT & session_events)
            {
              VCL_LOCK_AND_GET_SESSION (sid, &session);
              ready = vppcom_session_write_ready (session, sid);
              clib_spinlock_unlock (&vcm->sessions_lockp);
-             if (ready > 0)
+             if ((ready > 0) && (EPOLLOUT & et_mask))
                {
                  add_event = 1;
                  events[num_ev].events |= EPOLLOUT;
-                 if (EPOLLET & session_events)
+                 if (((EPOLLET | EPOLLOUT) & session_events) ==
+                     (EPOLLET | EPOLLOUT))
                    clear_et_mask |= EPOLLOUT;
                }
              else if (ready < 0)
@@ -3256,8 +4268,10 @@ vppcom_epoll_wait (uint32_t vep_idx, struct epoll_event *events,
                next_sid = ~0;
            }
        }
+      if (wait_for_time != -1)
+       keep_trying = (clib_time_now (&vcm->clib_time) <= timeout) ? 1 : 0;
     }
-  while ((num_ev == 0) && (clib_time_now (&vcm->clib_time) <= timeout));
+  while ((num_ev == 0) && keep_trying);
 
   if (wait_cont_idx != ~0)
     {
@@ -3273,7 +4287,6 @@ int
 vppcom_session_attr (uint32_t session_index, uint32_t op,
                     void *buffer, uint32_t * buflen)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   session_t *session;
   int rv = VPPCOM_OK;
   u32 *flags = buffer;
@@ -3284,44 +4297,127 @@ vppcom_session_attr (uint32_t session_index, uint32_t op,
     {
     case VPPCOM_ATTR_GET_NREAD:
       rv = vppcom_session_read_ready (session, session_index);
+      if (VPPCOM_DEBUG > 2)
+       clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_NREAD: sid %u, nread = %d",
+                     getpid (), rv);
       if (VPPCOM_DEBUG > 0)
-       clib_warning ("VPPCOM_ATTR_GET_NREAD: nread = %d", rv);
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+           {
+             .format = "VPPCOM_ATTR_GET_NREAD: nread=%d",
+             .format_args = "i4",
+           };
+         struct
+         {
+           u32 data;
+         } *ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+         ed->data = rv;
+         /* *INDENT-ON* */
+       }
 
       break;
 
-    case VPPCOM_ATTR_PEEK_NREAD:
-      /* TBD */
+    case VPPCOM_ATTR_GET_NWRITE:
+      rv = vppcom_session_write_ready (session, session_index);
+      if (VPPCOM_DEBUG > 2)
+       clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_NWRITE: sid %u, nwrite = %d",
+                     getpid (), session_index, rv);
+      if (VPPCOM_DEBUG > 0)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+           {
+             .format = "VPPCOM_ATTR_GET_NWRITE: nwrite=%d",
+             .format_args = "i4",
+           };
+         struct
+         {
+           u32 data;
+         } *ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+         ed->data = rv;
+         /* *INDENT-ON* */
+       }
       break;
 
     case VPPCOM_ATTR_GET_FLAGS:
-      if (buffer && buflen && (*buflen >= sizeof (*flags)))
+      if (PREDICT_TRUE (buffer && buflen && (*buflen >= sizeof (*flags))))
        {
          *flags = O_RDWR | ((session->is_nonblocking) ? O_NONBLOCK : 0);
          *buflen = sizeof (*flags);
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_FLAGS: sid %u, "
+                         "flags = 0x%08x, is_nonblocking = %u", getpid (),
+                         session_index, *flags, session->is_nonblocking);
          if (VPPCOM_DEBUG > 0)
-           clib_warning ("VPPCOM_ATTR_GET_FLAGS: flags = 0x%08x, "
-                         "is_nonblocking = %u", *flags,
-                         session->is_nonblocking);
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_FLAGS: flags=%x is_nonblk=%d",
+                 .format_args = "i4i4",
+               };
+             struct
+             {
+               u32 flags;
+               u32 is_nonblk;
+             } *ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+             ed->flags = *flags;
+             ed->is_nonblk = session->is_nonblocking;
+             /* *INDENT-ON* */
+           }
+
        }
       else
        rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_FLAGS:
-      if (buffer && buflen && (*buflen >= sizeof (*flags)))
+      if (PREDICT_TRUE (buffer && buflen && (*buflen == sizeof (*flags))))
        {
          session->is_nonblocking = (*flags & O_NONBLOCK) ? 1 : 0;
-         if (VPPCOM_DEBUG > 0)
-           clib_warning ("VPPCOM_ATTR_SET_FLAGS: flags = 0x%08x, "
-                         "is_nonblocking = %u", *flags,
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_FLAGS: sid %u, "
+                         "flags = 0x%08x, is_nonblocking = %u",
+                         getpid (), session_index, *flags,
                          session->is_nonblocking);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_SET_FLAGS: flags=%x is_nonblk=%d",
+                 .format_args = "i4i4",
+               };
+             struct
+             {
+               u32 flags;
+               u32 is_nonblk;
+             } *ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+             ed->flags = *flags;
+             ed->is_nonblk = session->is_nonblocking;
+             /* *INDENT-ON* */
+           }
        }
       else
        rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_GET_PEER_ADDR:
-      if (buffer && buflen && (*buflen >= sizeof (*ep)))
+      if (PREDICT_TRUE (buffer && buflen &&
+                       (*buflen >= sizeof (*ep)) && ep->ip))
        {
          ep->vrf = session->vrf;
          ep->is_ip4 = session->peer_addr.is_ip4;
@@ -3333,19 +4429,62 @@ vppcom_session_attr (uint32_t session_index, uint32_t op,
            clib_memcpy (ep->ip, &session->peer_addr.ip46.ip6,
                         sizeof (ip6_address_t));
          *buflen = sizeof (*ep);
-         if (VPPCOM_DEBUG > 0)
-           clib_warning ("VPPCOM_ATTR_GET_PEER_ADDR: sid %u is_ip4 = %u, "
-                         "addr = %U, port %u", session_index,
-                         ep->is_ip4, format_ip46_address,
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_PEER_ADDR: sid %u, "
+                         "is_ip4 = %u, addr = %U, port %u", getpid (),
+                         session_index, ep->is_ip4, format_ip46_address,
                          &session->peer_addr.ip46, ep->is_ip4,
                          clib_net_to_host_u16 (ep->port));
+         if (VPPCOM_DEBUG > 0)
+           {
+             if (ep->is_ip4)
+               {
+                 /* *INDENT-OFF* */
+                 ELOG_TYPE_DECLARE (e) =
+                   {
+                     .format = "VPPCOM_ATTR_GET_PEER_ADDR: addr:%d.%d.%d.%d:%d",
+                     .format_args = "i1i1i1i1i2",
+                   };
+                 CLIB_PACKED (struct {
+                   u8 addr[4]; //4
+                   u16 port;   //2
+                 }) * ed;
+
+                 ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+                 ed->addr[0] = session->peer_addr.ip46.ip4.as_u8[0];
+                 ed->addr[1] = session->peer_addr.ip46.ip4.as_u8[1];
+                 ed->addr[2] = session->peer_addr.ip46.ip4.as_u8[2];
+                 ed->addr[3] = session->peer_addr.ip46.ip4.as_u8[3];
+                 ed->port = clib_net_to_host_u16 (session->peer_port);
+                 /* *INDENT-ON* */
+               }
+             else
+               {
+                 /* *INDENT-OFF* */
+                 ELOG_TYPE_DECLARE (e) =
+                   {
+                     .format = "VPPCOM_ATTR_GET_PEER_ADDR: addr:IP6:%d",
+                     .format_args = "i2",
+                   };
+                 CLIB_PACKED (struct {
+                   u16 port;   //2
+                 }) * ed;
+
+                 ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+                 ed->port = clib_net_to_host_u16 (session->peer_port);
+                 /* *INDENT-ON* */
+               }
+           }
        }
       else
        rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_GET_LCL_ADDR:
-      if (buffer && buflen && (*buflen >= sizeof (*ep)))
+      if (PREDICT_TRUE (buffer && buflen &&
+                       (*buflen >= sizeof (*ep)) && ep->ip))
        {
          ep->vrf = session->vrf;
          ep->is_ip4 = session->lcl_addr.is_ip4;
@@ -3357,33 +4496,795 @@ vppcom_session_attr (uint32_t session_index, uint32_t op,
            clib_memcpy (ep->ip, &session->lcl_addr.ip46.ip6,
                         sizeof (ip6_address_t));
          *buflen = sizeof (*ep);
-         if (VPPCOM_DEBUG > 0)
-           clib_warning ("VPPCOM_ATTR_GET_LCL_ADDR: sid %u is_ip4 = %u, "
-                         "addr = %U port %d", session_index,
-                         ep->is_ip4, format_ip46_address,
+         if (VPPCOM_DEBUG > 1)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_LCL_ADDR: sid %u, "
+                         "is_ip4 = %u, addr = %U port %d", getpid (),
+                         session_index, ep->is_ip4, format_ip46_address,
                          &session->lcl_addr.ip46, ep->is_ip4,
                          clib_net_to_host_u16 (ep->port));
+         if (VPPCOM_DEBUG > 0)
+           {
+             if (ep->is_ip4)
+               {
+                 /* *INDENT-OFF* */
+                 ELOG_TYPE_DECLARE (e) =
+                   {
+                     .format = "VPPCOM_ATTR_GET_LCL_ADDR: addr:%d.%d.%d.%d:%d",
+                     .format_args = "i1i1i1i1i2",
+                   };
+                 CLIB_PACKED (struct {
+                   u8 addr[4]; //4
+                   u16 port;   //2
+                 }) * ed;
+
+                 ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+                 ed->addr[0] = session->lcl_addr.ip46.ip4.as_u8[0];
+                 ed->addr[1] = session->lcl_addr.ip46.ip4.as_u8[1];
+                 ed->addr[2] = session->lcl_addr.ip46.ip4.as_u8[2];
+                 ed->addr[3] = session->lcl_addr.ip46.ip4.as_u8[3];
+                 ed->port = clib_net_to_host_u16 (session->peer_port);
+                 /* *INDENT-ON* */
+               }
+             else
+               {
+                 /* *INDENT-OFF* */
+                 ELOG_TYPE_DECLARE (e) =
+                   {
+                     .format = "VPPCOM_ATTR_GET_LCL_ADDR: addr:IP6:%d",
+                     .format_args = "i2",
+                   };
+                 CLIB_PACKED (struct {
+                   u16 port;   //2
+                 }) * ed;
+
+                 ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+                 ed->port = clib_net_to_host_u16 (session->peer_port);
+                 /* *INDENT-ON* */
+               }
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_LIBC_EPFD:
+      rv = session->libc_epfd;
+      if (VPPCOM_DEBUG > 2)
+       clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_LIBC_EPFD: libc_epfd %d",
+                     getpid (), rv);
+      if (VPPCOM_DEBUG > 0)
+       {
+         /* *INDENT-OFF* */
+         ELOG_TYPE_DECLARE (e) =
+           {
+             .format = "VPPCOM_ATTR_GET_LIBC_EPFD: libc_epfd=%s%d buflen=%d",
+             .format_args = "t1i4i4",
+             .n_enum_strings = 2,
+             .enum_strings = {"", "-",},
+           };
+         CLIB_PACKED (struct {
+           u8 sign;
+           u32 data[2];
+         }) * ed;
+
+         ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+         ed->sign = (session->libc_epfd < 0);
+         ed->data[0] = abs(session->libc_epfd);
+         ed->data[1] = *buflen;
+         /* *INDENT-ON* */
+       }
+
+      break;
+
+    case VPPCOM_ATTR_SET_LIBC_EPFD:
+      if (PREDICT_TRUE (buffer && buflen &&
+                       (*buflen == sizeof (session->libc_epfd))))
+       {
+         session->libc_epfd = *(int *) buffer;
+         *buflen = sizeof (session->libc_epfd);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_LIBC_EPFD: libc_epfd %d, "
+                         "buflen %d", getpid (), session->libc_epfd,
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_SET_LIBC_EPFD: libc_epfd=%s%d buflen=%d",
+                 .format_args = "t1i4i4",
+                 .n_enum_strings = 2,
+                 .enum_strings = {"", "-",},
+               };
+             CLIB_PACKED (struct {
+               u8 sign;
+               u32 data[2];
+             }) * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+
+             ed->sign = (session->libc_epfd < 0);
+             ed->data[0] = abs(session->libc_epfd);
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_PROTOCOL:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         *(int *) buffer = session->proto;
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_PROTOCOL: %d (%s), "
+                         "buflen %d", getpid (), *(int *) buffer,
+                         *(int *) buffer ? "UDP" : "TCP", *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_PROTOCOL: %s buflen=%d",
+                 .format_args = "t1i4",
+                 .n_enum_strings = 2,
+                 .enum_strings = {"TCP", "UDP",},
+               };
+
+             CLIB_PACKED (struct {
+               u8 proto;
+               u32 buflen;
+             }) * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->proto = session->proto;
+             ed->buflen = *(int *) buffer;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_LISTEN:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_LISTEN);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_LISTEN: %d, "
+                         "buflen %d", getpid (), *(int *) buffer, *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_LISTEN: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(int *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_ERROR:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         *(int *) buffer = 0;
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_ERROR: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         *(int *) buffer, *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_ERROR: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(int *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_TX_FIFO_LEN:
+      if (buffer && buflen && (*buflen >= sizeof (u32)))
+       {
+         svm_fifo_t *tx_fifo;
+
+         tx_fifo = ((!session->is_cut_thru || session->is_server) ?
+                    session->server_tx_fifo : session->server_rx_fifo);
+
+         /* VPP-TBD */
+         *(size_t *) buffer = (session->sndbuf_size ? session->sndbuf_size :
+                               tx_fifo ? tx_fifo->nitems :
+                               vcm->cfg.tx_fifo_size);
+         *buflen = sizeof (u32);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_TX_FIFO_LEN: %u (0x%x), "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         *(size_t *) buffer, *(size_t *) buffer, *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_TX_FIFO_LEN: 0x%x buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(size_t *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_SET_TX_FIFO_LEN:
+      if (buffer && buflen && (*buflen == sizeof (u32)))
+       {
+         /* VPP-TBD */
+         session->sndbuf_size = *(u32 *) buffer;
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_TX_FIFO_LEN: %u (0x%x), "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         session->sndbuf_size, session->sndbuf_size,
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_SET_TX_FIFO_LEN: 0x%x buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = session->sndbuf_size;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_RX_FIFO_LEN:
+      if (buffer && buflen && (*buflen >= sizeof (u32)))
+       {
+         svm_fifo_t *rx_fifo;
+
+         rx_fifo = ((!session->is_cut_thru || session->is_server) ?
+                    session->server_rx_fifo : session->server_tx_fifo);
+
+         /* VPP-TBD */
+         *(size_t *) buffer = (session->rcvbuf_size ? session->rcvbuf_size :
+                               rx_fifo ? rx_fifo->nitems :
+                               vcm->cfg.rx_fifo_size);
+         *buflen = sizeof (u32);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_RX_FIFO_LEN: %u (0x%x), "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         *(size_t *) buffer, *(size_t *) buffer, *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_RX_FIFO_LEN: 0x%x buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(size_t *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_SET_RX_FIFO_LEN:
+      if (buffer && buflen && (*buflen == sizeof (u32)))
+       {
+         /* VPP-TBD */
+         session->rcvbuf_size = *(u32 *) buffer;
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_TX_FIFO_LEN: %u (0x%x), "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         session->sndbuf_size, session->sndbuf_size,
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_SET_TX_FIFO_LEN: 0x%x buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = session->sndbuf_size;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_REUSEADDR:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_REUSEADDR);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_REUSEADDR: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_REUSEADDR: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(int *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
        }
       else
        rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_REUSEADDR:
+      if (buffer && buflen && (*buflen == sizeof (int)) &&
+         !VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_LISTEN))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_REUSEADDR);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_REUSEADDR);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_REUSEADDR: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_REUSEADDR),
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_SET_REUSEADDR: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_REUSEADDR);
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_REUSEPORT:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_REUSEPORT);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_REUSEPORT: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_REUSEPORT: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(int *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_SET_REUSEPORT:
+      if (buffer && buflen && (*buflen == sizeof (int)) &&
+         !VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_LISTEN))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_REUSEPORT);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_REUSEPORT);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_REUSEPORT: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_REUSEPORT),
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_SET_REUSEPORT: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_REUSEPORT);
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_BROADCAST:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_BROADCAST);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_BROADCAST: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+         if (VPPCOM_DEBUG > 0)
+           {
+             /* *INDENT-OFF* */
+             ELOG_TYPE_DECLARE (e) =
+               {
+                 .format = "VPPCOM_ATTR_GET_BROADCAST: %d buflen=%d",
+                 .format_args = "i4i4",
+               };
+
+             struct {
+               u32 data[2];
+             } * ed;
+
+             ed = ELOG_TRACK_DATA (&vcm->elog_main, e, session->elog_track);
+             ed->data[0] = *(int *) buffer;
+             ed->data[1] = *buflen;
+             /* *INDENT-ON* */
+           }
+       }
+      else
+       rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_BROADCAST:
+      if (buffer && buflen && (*buflen == sizeof (int)))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_BROADCAST);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_BROADCAST);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_BROADCAST: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_BROADCAST),
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_V6ONLY:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_V6ONLY);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_V6ONLY: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_V6ONLY:
+      if (buffer && buflen && (*buflen == sizeof (int)))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_V6ONLY);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_V6ONLY);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_V6ONLY: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_V6ONLY), *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_KEEPALIVE:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_KEEPALIVE);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_KEEPALIVE: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_KEEPALIVE:
+      if (buffer && buflen && (*buflen == sizeof (int)))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_KEEPALIVE);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_KEEPALIVE);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_KEEPALIVE: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_KEEPALIVE),
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_TCP_NODELAY:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_TCP_NODELAY);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_TCP_NODELAY: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_SET_TCP_NODELAY:
+      if (buffer && buflen && (*buflen == sizeof (int)))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_TCP_NODELAY);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_TCP_NODELAY);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_TCP_NODELAY: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_TCP_NODELAY),
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_TCP_KEEPIDLE:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_TCP_KEEPIDLE);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_TCP_KEEPIDLE: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_TCP_KEEPIDLE:
+      if (buffer && buflen && (*buflen == sizeof (int)))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_TCP_KEEPIDLE);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_TCP_KEEPIDLE);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_TCP_KEEPIDLE: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_TCP_KEEPIDLE),
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_TCP_KEEPINTVL:
+      if (buffer && buflen && (*buflen >= sizeof (int)))
+       {
+         /* VPP-TBD */
+         *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
+                                               VCL_SESS_ATTR_TCP_KEEPINTVL);
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_TCP_KEEPINTVL: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
       break;
 
     case VPPCOM_ATTR_SET_TCP_KEEPINTVL:
+      if (buffer && buflen && (*buflen == sizeof (int)))
+       {
+         /* VPP-TBD */
+         if (*(int *) buffer)
+           VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_TCP_KEEPINTVL);
+         else
+           VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_TCP_KEEPINTVL);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_TCP_KEEPINTVL: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         VCL_SESS_ATTR_TEST (session->attr,
+                                             VCL_SESS_ATTR_TCP_KEEPINTVL),
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_GET_TCP_USER_MSS:
+      if (buffer && buflen && (*buflen >= sizeof (u32)))
+       {
+         /* VPP-TBD */
+         *(u32 *) buffer = session->user_mss;
+         *buflen = sizeof (int);
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_TCP_USER_MSS: %d, "
+                         "buflen %d, #VPP-TBD#", getpid (), *(int *) buffer,
+                         *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
+      break;
+
+    case VPPCOM_ATTR_SET_TCP_USER_MSS:
+      if (buffer && buflen && (*buflen == sizeof (u32)))
+       {
+         /* VPP-TBD */
+         session->user_mss = *(u32 *) buffer;
+
+         if (VPPCOM_DEBUG > 2)
+           clib_warning ("VCL<%d>: VPPCOM_ATTR_SET_TCP_KEEPINTVL: %u, "
+                         "buflen %d, #VPP-TBD#", getpid (),
+                         session->user_mss, *buflen);
+       }
+      else
+       rv = VPPCOM_EINVAL;
       break;
 
     default:
@@ -3400,7 +5301,6 @@ int
 vppcom_session_recvfrom (uint32_t session_index, void *buffer,
                         uint32_t buflen, int flags, vppcom_endpt_t * ep)
 {
-  vppcom_main_t *vcm = &vppcom_main;
   int rv = VPPCOM_OK;
   session_t *session = 0;
 
@@ -3412,9 +5312,12 @@ vppcom_session_recvfrom (uint32_t session_index, void *buffer,
        {
          clib_spinlock_unlock (&vcm->sessions_lockp);
          if (VPPCOM_DEBUG > 0)
-           clib_warning ("[%d] invalid session, sid (%u) has been closed!",
-                         vcm->my_pid, session_index);
-         rv = VPPCOM_EINVAL;
+           clib_warning ("VCL<%d>: invalid session, "
+                         "sid (%u) has been closed!",
+                         getpid (), session_index);
+         rv = VPPCOM_EBADFD;
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+         goto done;
        }
       ep->vrf = session->vrf;
       ep->is_ip4 = session->peer_addr.is_ip4;
@@ -3434,10 +5337,12 @@ vppcom_session_recvfrom (uint32_t session_index, void *buffer,
     rv = vppcom_session_peek (session_index, buffer, buflen);
   else
     {
-      clib_warning ("Unsupport flags for recvfrom %d", flags);
+      clib_warning ("VCL<%d>: Unsupport flags for recvfrom %d",
+                   getpid (), flags);
       rv = VPPCOM_EAFNOSUPPORT;
     }
 
+done:
   return rv;
 }
 
@@ -3445,8 +5350,6 @@ int
 vppcom_session_sendto (uint32_t session_index, void *buffer,
                       uint32_t buflen, int flags, vppcom_endpt_t * ep)
 {
-  vppcom_main_t *vcm = &vppcom_main;
-
   if (!buffer)
     return VPPCOM_EINVAL;
 
@@ -3460,13 +5363,118 @@ vppcom_session_sendto (uint32_t session_index, void *buffer,
     {
       // TBD check the flags and do the right thing
       if (VPPCOM_DEBUG > 2)
-       clib_warning ("[%d] handling flags 0x%u (%d) not implemented yet.",
-                     vcm->my_pid, flags, flags);
+       clib_warning ("VCL<%d>: handling flags 0x%u (%d) "
+                     "not implemented yet.", getpid (), flags, flags);
     }
 
   return (vppcom_session_write (session_index, buffer, buflen));
 }
 
+int
+vppcom_poll (vcl_poll_t * vp, uint32_t n_sids, double wait_for_time)
+{
+  f64 timeout = clib_time_now (&vcm->clib_time) + wait_for_time;
+  u32 i, keep_trying = 1;
+  int rv, num_ev = 0;
+
+  if (VPPCOM_DEBUG > 3)
+    clib_warning ("VCL<%d>: vp %p, nsids %u, wait_for_time %f",
+                 getpid (), vp, n_sids, wait_for_time);
+
+  if (!vp)
+    return VPPCOM_EFAULT;
+
+  do
+    {
+      session_t *session;
+
+      for (i = 0; i < n_sids; i++)
+       {
+         ASSERT (vp[i].revents);
+
+         VCL_LOCK_AND_GET_SESSION (vp[i].sid, &session);
+         clib_spinlock_unlock (&vcm->sessions_lockp);
+
+         if (*vp[i].revents)
+           *vp[i].revents = 0;
+
+         if (POLLIN & vp[i].events)
+           {
+             VCL_LOCK_AND_GET_SESSION (vp[i].sid, &session);
+             rv = vppcom_session_read_ready (session, vp[i].sid);
+             clib_spinlock_unlock (&vcm->sessions_lockp);
+             if (rv > 0)
+               {
+                 *vp[i].revents |= POLLIN;
+                 num_ev++;
+               }
+             else if (rv < 0)
+               {
+                 switch (rv)
+                   {
+                   case VPPCOM_ECONNRESET:
+                     *vp[i].revents = POLLHUP;
+                     break;
+
+                   default:
+                     *vp[i].revents = POLLERR;
+                     break;
+                   }
+                 num_ev++;
+               }
+           }
+
+         if (POLLOUT & vp[i].events)
+           {
+             VCL_LOCK_AND_GET_SESSION (vp[i].sid, &session);
+             rv = vppcom_session_write_ready (session, vp[i].sid);
+             clib_spinlock_unlock (&vcm->sessions_lockp);
+             if (rv > 0)
+               {
+                 *vp[i].revents |= POLLOUT;
+                 num_ev++;
+               }
+             else if (rv < 0)
+               {
+                 switch (rv)
+                   {
+                   case VPPCOM_ECONNRESET:
+                     *vp[i].revents = POLLHUP;
+                     break;
+
+                   default:
+                     *vp[i].revents = POLLERR;
+                     break;
+                   }
+                 num_ev++;
+               }
+           }
+
+         if (0)
+           {
+           done:
+             *vp[i].revents = POLLNVAL;
+             num_ev++;
+           }
+       }
+      if (wait_for_time != -1)
+       keep_trying = (clib_time_now (&vcm->clib_time) <= timeout) ? 1 : 0;
+    }
+  while ((num_ev == 0) && keep_trying);
+
+  if (VPPCOM_DEBUG > 3)
+    {
+      clib_warning ("VCL<%d>: returning %d", getpid (), num_ev);
+      for (i = 0; i < n_sids; i++)
+       {
+         clib_warning ("VCL<%d>: vp[%d].sid %d (0x%x), .events 0x%x, "
+                       ".revents 0x%x", getpid (), i, vp[i].sid, vp[i].sid,
+                       vp[i].events, *vp[i].revents);
+       }
+    }
+  return num_ev;
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *