hsa: move vcl test apps to hsa

Type: refactor

Change-Id: I352975585c1091bfc5b85d7f8fe985f9059820a7
Signed-off-by: Florin Coras <fcoras@cisco.com>

10 files changed, 4823 insertions, 6 deletions

diff --git a/src/plugins/hs_apps/CMakeLists.txt b/src/plugins/hs_apps/CMakeLists.txt
index e7885c3d1bf..bf1f49cfa42 100644
--- a/src/plugins/hs_apps/CMakeLists.txt
+++ b/src/plugins/hs_apps/CMakeLists.txt
@@ -11,6 +11,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+##############################################################################
+# vpp builtin hs apps
+##############################################################################
 add_vpp_plugin(hs_apps
   SOURCES
   echo_client.c
@@ -20,24 +23,46 @@ add_vpp_plugin(hs_apps
   proxy.c
 )
 
-option(VPP_BUILD_SESSION_ECHO_APPS "Build session echo apps." ON)
-if(VPP_BUILD_SESSION_ECHO_APPS)
+##############################################################################
+# vpp external hs apps that use the "raw" session layer api
+##############################################################################
+option(VPP_BUILD_HS_SAPI_APPS "Build hs apps that use the session api." ON)
+if(VPP_BUILD_HS_SAPI_APPS)
   add_vpp_executable(tcp_echo
-    SOURCES tcp_echo.c
+    SOURCES sapi/tcp_echo.c
     LINK_LIBRARIES vlibmemoryclient svm vppinfra pthread m rt
     DEPENDS api_headers
     NO_INSTALL
   )
   add_vpp_executable(quic_echo
-    SOURCES quic_echo.c
+    SOURCES sapi/quic_echo.c
     LINK_LIBRARIES vlibmemoryclient svm vppinfra pthread m rt
     DEPENDS api_headers
     NO_INSTALL
   )
   add_vpp_executable(udp_echo
-    SOURCES udp_echo.c
+    SOURCES sapi/udp_echo.c
     LINK_LIBRARIES vlibmemoryclient svm vppinfra pthread m rt
     DEPENDS api_headers
     NO_INSTALL
   )
-endif(VPP_BUILD_SESSION_ECHO_APPS)
+endif(VPP_BUILD_HS_SAPI_APPS)
+
+##############################################################################
+# vcl tests
+##############################################################################
+option(VPP_BUILD_VCL_TESTS "Build vcl tests." ON)
+if(VPP_BUILD_VCL_TESTS)
+  foreach(test
+    vcl_test_server
+    vcl_test_client
+    sock_test_server
+    sock_test_client
+  )
+    add_vpp_executable(${test}
+      SOURCES "vcl/${test}.c"
+      LINK_LIBRARIES vppcom pthread
+      NO_INSTALL
+    )
+  endforeach()
+endif(VPP_BUILD_VCL_TESTS)
diff --git a/src/plugins/hs_apps/quic_echo.c b/src/plugins/hs_apps/sapi/quic_echo.c
index a62af642b2f..a62af642b2f 100644
--- a/src/plugins/hs_apps/quic_echo.c
+++ b/src/plugins/hs_apps/sapi/quic_echo.c
diff --git a/src/plugins/hs_apps/tcp_echo.c b/src/plugins/hs_apps/sapi/tcp_echo.c
index 6c3ce928490..6c3ce928490 100644
--- a/src/plugins/hs_apps/tcp_echo.c
+++ b/src/plugins/hs_apps/sapi/tcp_echo.c
diff --git a/src/plugins/hs_apps/udp_echo.c b/src/plugins/hs_apps/sapi/udp_echo.c
index c9992befe98..c9992befe98 100644
--- a/src/plugins/hs_apps/udp_echo.c
+++ b/src/plugins/hs_apps/sapi/udp_echo.c
diff --git a/src/plugins/hs_apps/vcl/sock_test.h b/src/plugins/hs_apps/vcl/sock_test.h
new file mode 100644
index 00000000000..9f7f4379ce7
--- /dev/null
+++ b/src/plugins/hs_apps/vcl/sock_test.h
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __sock_test_h__
+#define __sock_test_h__
+
+#include <netdb.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <hs_apps/vcl/vcl_test.h>
+
+#define SOCK_TEST_AF_UNIX_FILENAME    "/tmp/ldp_server_af_unix_socket"
+#define SOCK_TEST_MIXED_EPOLL_DATA    "Hello, world! (over an AF_UNIX socket)"
+#define SOCK_TEST_AF_UNIX_ACCEPT_DATA 0xaf0000af
+#define SOCK_TEST_AF_UNIX_FD_MASK     0x00af0000
+#define SOCK_TEST_BANNER_STRING \
+  "============================================\n"
+
+static inline int
+sock_test_read (int fd, uint8_t *buf, uint32_t nbytes,
+                vcl_test_stats_t *stats)
+{
+  int rx_bytes, errno_val;
+  
+  do
+    {
+      if (stats)
+        stats->rx_xacts++;
+      rx_bytes = read (fd, buf, nbytes);
+      if (stats)
+        {
+          if ((rx_bytes == 0) ||
+              ((rx_bytes < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK))))
+            stats->rx_eagain++;
+          else if (rx_bytes < nbytes)
+            stats->rx_incomp++;
+        }
+    }
+  while ((rx_bytes == 0) ||
+         ((rx_bytes < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK))));
+  
+  if (rx_bytes < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in sock_test_read()");
+      fprintf (stderr, "SOCK_TEST: ERROR: socket read "
+               "failed (errno = %d)!\n", errno_val);
+      errno = errno_val;
+    }
+  else if (stats)
+    stats->rx_bytes += rx_bytes;
+
+  return (rx_bytes);
+}
+
+static inline int
+sock_test_write (int fd, uint8_t *buf, uint32_t nbytes,
+                 vcl_test_stats_t *stats, uint32_t verbose)
+{
+  int tx_bytes = 0;
+  int nbytes_left = nbytes;
+  int rv, errno_val;
+
+  do
+    {
+      if (stats)
+        stats->tx_xacts++;
+      rv = write (fd, buf, nbytes_left);
+      if (rv < 0)
+        {
+          if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
+            {
+              if (stats)
+                stats->tx_eagain++;
+              continue;
+            }
+          else
+            break;
+        }
+      tx_bytes += rv;
+     
+      if (tx_bytes != nbytes)
+        {
+          nbytes_left = nbytes_left - rv;
+          if (stats)
+            stats->tx_incomp++;
+          if (verbose)
+            {
+              printf ("SOCK_TEST: WARNING: bytes written (%d) "
+                      "!= bytes to write (%d)!\n", tx_bytes, nbytes);
+            }
+        }
+     
+    } while (tx_bytes != nbytes);
+
+  if (tx_bytes < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in sock_test_write()");
+      fprintf (stderr, "SOCK_TEST: ERROR: socket write failed "
+               "(errno = %d)!\n", errno_val);
+    }
+  else if (stats)
+    stats->tx_bytes += tx_bytes;
+  
+  return (tx_bytes);
+}
+
+#endif /* __sock_test_h__ */
diff --git a/src/plugins/hs_apps/vcl/sock_test_client.c b/src/plugins/hs_apps/vcl/sock_test_client.c
new file mode 100644
index 00000000000..ea89987f325
--- /dev/null
+++ b/src/plugins/hs_apps/vcl/sock_test_client.c
@@ -0,0 +1,1277 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <time.h>
+#include <arpa/inet.h>
+#include <hs_apps/vcl/sock_test.h>
+#include <fcntl.h>
+#ifndef VCL_TEST
+#include <sys/un.h>
+#endif
+
+typedef struct
+{
+#ifdef VCL_TEST
+  vppcom_endpt_t server_endpt;
+#else
+  int af_unix_echo_tx;
+  int af_unix_echo_rx;
+#endif
+  struct sockaddr_storage server_addr;
+  uint32_t server_addr_size;
+  uint32_t cfg_seq_num;
+  vcl_test_session_t ctrl_socket;
+  vcl_test_session_t *test_socket;
+  uint32_t num_test_sockets;
+  uint8_t dump_cfg;
+} sock_client_main_t;
+
+sock_client_main_t vcl_client_main;
+
+
+static int
+sock_test_cfg_sync (vcl_test_session_t * socket)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  vcl_test_cfg_t *rl_cfg = (vcl_test_cfg_t *) socket->rxbuf;
+  int rx_bytes, tx_bytes;
+
+  if (socket->cfg.verbose)
+    vcl_test_cfg_dump (&socket->cfg, 1 /* is_client */ );
+
+  ctrl->cfg.seq_num = ++scm->cfg_seq_num;
+  if (socket->cfg.verbose)
+    {
+      printf ("CLIENT (fd %d): Sending config sent to server.\n", socket->fd);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  tx_bytes = sock_test_write (socket->fd, (uint8_t *) & ctrl->cfg,
+			      sizeof (ctrl->cfg), NULL, ctrl->cfg.verbose);
+  if (tx_bytes < 0)
+    {
+      fprintf (stderr, "CLIENT (fd %d): ERROR: write test cfg failed (%d)!\n",
+	       socket->fd, tx_bytes);
+      return tx_bytes;
+    }
+
+  rx_bytes = sock_test_read (socket->fd, (uint8_t *) socket->rxbuf,
+			     sizeof (vcl_test_cfg_t), NULL);
+  if (rx_bytes < 0)
+    return rx_bytes;
+
+  if (rl_cfg->magic != VCL_TEST_CFG_CTRL_MAGIC)
+    {
+      fprintf (stderr, "CLIENT (fd %d): ERROR: Bad server reply cfg "
+	       "-- aborting!\n", socket->fd);
+      return -1;
+    }
+  if ((rx_bytes != sizeof (vcl_test_cfg_t))
+      || !vcl_test_cfg_verify (rl_cfg, &ctrl->cfg))
+    {
+      fprintf (stderr, "CLIENT (fd %d): ERROR: Invalid config received "
+	       "from server!\n", socket->fd);
+      if (rx_bytes != sizeof (vcl_test_cfg_t))
+	{
+	  fprintf (stderr, "\tRx bytes %d != cfg size %lu\n",
+		   rx_bytes, sizeof (vcl_test_cfg_t));
+	}
+      else
+	{
+	  vcl_test_cfg_dump (rl_cfg, 1 /* is_client */ );
+	  fprintf (stderr, "CLIENT (fd %d): Valid config sent to server.\n",
+		   socket->fd);
+	  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+	}
+      return -1;
+    }
+  else if (socket->cfg.verbose)
+    {
+      printf ("CLIENT (fd %d): Got config back from server.\n", socket->fd);
+      vcl_test_cfg_dump (rl_cfg, 1 /* is_client */ );
+    }
+  ctrl->cfg.ctrl_handle = ((ctrl->cfg.ctrl_handle == ~0) ?
+			   rl_cfg->ctrl_handle : ctrl->cfg.ctrl_handle);
+
+  return 0;
+}
+
+static void
+echo_test_client ()
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  vcl_test_session_t *tsock;
+  int rx_bytes, tx_bytes, nbytes;
+  uint32_t i, n;
+  int rv;
+  int nfds = 0;
+  fd_set wr_fdset, rd_fdset;
+  fd_set _wfdset, *wfdset = &_wfdset;
+  fd_set _rfdset, *rfdset = &_rfdset;
+
+  FD_ZERO (&wr_fdset);
+  FD_ZERO (&rd_fdset);
+  memset (&ctrl->stats, 0, sizeof (ctrl->stats));
+  ctrl->cfg.total_bytes = nbytes = strlen (ctrl->txbuf) + 1;
+  for (n = 0; n != ctrl->cfg.num_test_sessions; n++)
+    {
+      tsock = &scm->test_socket[n];
+      tsock->cfg = ctrl->cfg;
+      vcl_test_session_buf_alloc (tsock);
+      if (sock_test_cfg_sync (tsock))
+	return;
+
+      memcpy (tsock->txbuf, ctrl->txbuf, nbytes);
+      memset (&tsock->stats, 0, sizeof (tsock->stats));
+
+      FD_SET (tsock->fd, &wr_fdset);
+      FD_SET (tsock->fd, &rd_fdset);
+      nfds = ((tsock->fd + 1) > nfds) ? (tsock->fd + 1) : nfds;
+    }
+
+  nfds++;
+  clock_gettime (CLOCK_REALTIME, &ctrl->stats.start);
+  while (n)
+    {
+      _wfdset = wr_fdset;
+      _rfdset = rd_fdset;
+
+#ifdef VCL_TEST
+      rv =
+	vppcom_select (nfds, (unsigned long *) rfdset,
+		       (unsigned long *) wfdset, NULL, 0);
+#else
+      {
+	struct timeval timeout;
+	timeout.tv_sec = 0;
+	timeout.tv_usec = 0;
+	rv = select (nfds, rfdset, wfdset, NULL, &timeout);
+      }
+#endif
+      if (rv < 0)
+	{
+	  perror ("select()");
+	  fprintf (stderr, "\nCLIENT: ERROR: select() failed -- "
+		   "aborting test!\n");
+	  return;
+	}
+      else if (rv == 0)
+	continue;
+
+      for (i = 0; i < ctrl->cfg.num_test_sessions; i++)
+	{
+	  tsock = &scm->test_socket[i];
+	  if (!((tsock->stats.stop.tv_sec == 0) &&
+		(tsock->stats.stop.tv_nsec == 0)))
+	    continue;
+
+	  if (FD_ISSET (tsock->fd, wfdset) &&
+	      (tsock->stats.tx_bytes < ctrl->cfg.total_bytes))
+
+	    {
+	      tx_bytes =
+		sock_test_write (tsock->fd, (uint8_t *) tsock->txbuf, nbytes,
+				 &tsock->stats, ctrl->cfg.verbose);
+	      if (tx_bytes < 0)
+		{
+		  fprintf (stderr, "\nCLIENT: ERROR: sock_test_write(%d) "
+			   "failed -- aborting test!\n", tsock->fd);
+		  return;
+		}
+
+	      printf ("CLIENT (fd %d): TX (%d bytes) - '%s'\n",
+		      tsock->fd, tx_bytes, tsock->txbuf);
+	    }
+
+	  if ((FD_ISSET (tsock->fd, rfdset)) &&
+	      (tsock->stats.rx_bytes < ctrl->cfg.total_bytes))
+	    {
+	      rx_bytes =
+		sock_test_read (tsock->fd, (uint8_t *) tsock->rxbuf,
+				nbytes, &tsock->stats);
+	      if (rx_bytes > 0)
+		{
+		  printf ("CLIENT (fd %d): RX (%d bytes) - '%s'\n",
+			  tsock->fd, rx_bytes, tsock->rxbuf);
+
+		  if (tsock->stats.rx_bytes != tsock->stats.tx_bytes)
+		    printf ("CLIENT: WARNING: bytes read (%lu) "
+			    "!= bytes written (%lu)!\n",
+			    tsock->stats.rx_bytes, tsock->stats.tx_bytes);
+		}
+	    }
+
+	  if (tsock->stats.rx_bytes >= ctrl->cfg.total_bytes)
+	    {
+	      clock_gettime (CLOCK_REALTIME, &tsock->stats.stop);
+	      n--;
+	    }
+	}
+    }
+  clock_gettime (CLOCK_REALTIME, &ctrl->stats.stop);
+
+#ifndef VCL_TEST
+  {
+    int fd, errno_val;
+    struct sockaddr_un serveraddr;
+    uint8_t buffer[256];
+    size_t nbytes = strlen (SOCK_TEST_MIXED_EPOLL_DATA) + 1;
+    struct timeval timeout;
+
+    /* Open AF_UNIX socket and send an echo to test mixed epoll on server.
+     */
+    fd = socket (AF_UNIX, SOCK_STREAM, 0);
+    if (fd < 0)
+      {
+	errno_val = errno;
+	perror ("ERROR in echo_test_client(): socket(AF_UNIX) failed");
+	fprintf (stderr,
+		 "CLIENT: ERROR: socket(AF_UNIX, SOCK_STREAM, 0) failed "
+		 "(errno = %d)!\n", errno_val);
+	goto out;
+      }
+    memset (&serveraddr, 0, sizeof (serveraddr));
+    serveraddr.sun_family = AF_UNIX;
+    strcpy (serveraddr.sun_path, SOCK_TEST_AF_UNIX_FILENAME);
+    rv = connect (fd, (struct sockaddr *) &serveraddr, SUN_LEN (&serveraddr));
+    if (rv < 0)
+      {
+	errno_val = errno;
+	perror ("ERROR in echo_test_client(): connect() failed");
+	fprintf (stderr, "CLIENT: ERROR: connect(fd %d, \"%s\", %lu) "
+		 "failed (errno = %d)!\n", fd, SOCK_TEST_AF_UNIX_FILENAME,
+		 SUN_LEN (&serveraddr), errno_val);
+	goto done;
+      }
+
+    scm->af_unix_echo_tx++;
+    strcpy ((char *) buffer, SOCK_TEST_MIXED_EPOLL_DATA);
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 250000;
+    select (0, NULL, NULL, NULL, &timeout);	/* delay .25 secs */
+    rv = write (fd, buffer, nbytes);
+    if (rv < 0)
+      {
+	errno_val = errno;
+	perror ("ERROR in echo_test_client(): write() failed");
+	fprintf (stderr, "CLIENT: ERROR: write(fd %d, \"%s\", %lu) "
+		 "failed (errno = %d)!\n", fd, buffer, nbytes, errno_val);
+	goto done;
+      }
+    else if (rv < nbytes)
+      {
+	fprintf (stderr, "CLIENT: ERROR: write(fd %d, \"%s\", %lu) "
+		 "returned %d!\n", fd, buffer, nbytes, rv);
+	goto done;
+      }
+
+    printf ("CLIENT (AF_UNIX): TX (%d bytes) - '%s'\n", rv, buffer);
+    memset (buffer, 0, sizeof (buffer));
+    rv = read (fd, buffer, nbytes);
+    if (rv < 0)
+      {
+	errno_val = errno;
+	perror ("ERROR in echo_test_client(): read() failed");
+	fprintf (stderr, "CLIENT: ERROR: read(fd %d, %p, %lu) "
+		 "failed (errno = %d)!\n", fd, buffer, nbytes, errno_val);
+	goto done;
+      }
+    else if (rv < nbytes)
+      {
+	fprintf (stderr, "CLIENT: ERROR: read(fd %d, %p, %lu) "
+		 "returned %d!\n", fd, buffer, nbytes, rv);
+	goto done;
+      }
+
+    if (!strncmp (SOCK_TEST_MIXED_EPOLL_DATA, (const char *) buffer, nbytes))
+      {
+	printf ("CLIENT (AF_UNIX): RX (%d bytes) - '%s'\n", rv, buffer);
+	scm->af_unix_echo_rx++;
+      }
+    else
+      printf ("CLIENT (AF_UNIX): ERROR: RX (%d bytes) - '%s'\n", rv, buffer);
+
+  done:
+    close (fd);
+  out:
+    ;
+  }
+#endif
+
+  for (i = 0; i < ctrl->cfg.num_test_sessions; i++)
+    {
+      tsock = &scm->test_socket[i];
+      tsock->stats.start = ctrl->stats.start;
+
+      if (ctrl->cfg.verbose)
+	{
+	  static char buf[64];
+
+	  sprintf (buf, "CLIENT (fd %d) RESULTS", tsock->fd);
+	  vcl_test_stats_dump (buf, &tsock->stats,
+			       1 /* show_rx */ , 1 /* show tx */ ,
+			       ctrl->cfg.verbose);
+	}
+
+      vcl_test_stats_accumulate (&ctrl->stats, &tsock->stats);
+    }
+
+  if (ctrl->cfg.verbose)
+    {
+      vcl_test_stats_dump ("CLIENT RESULTS", &ctrl->stats,
+			   1 /* show_rx */ , 1 /* show tx */ ,
+			   ctrl->cfg.verbose);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+
+      if (ctrl->cfg.verbose > 1)
+	{
+	  printf ("  ctrl socket info\n"
+		  VCL_TEST_SEPARATOR_STRING
+		  "          fd:  %d (0x%08x)\n"
+		  "       rxbuf:  %p\n"
+		  "  rxbuf size:  %u (0x%08x)\n"
+		  "       txbuf:  %p\n"
+		  "  txbuf size:  %u (0x%08x)\n"
+		  VCL_TEST_SEPARATOR_STRING,
+		  ctrl->fd, (uint32_t) ctrl->fd,
+		  ctrl->rxbuf, ctrl->rxbuf_size, ctrl->rxbuf_size,
+		  ctrl->txbuf, ctrl->txbuf_size, ctrl->txbuf_size);
+	}
+    }
+}
+
+static void
+stream_test_client (vcl_test_t test)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  vcl_test_session_t *tsock;
+  int tx_bytes;
+  uint32_t i, n;
+  int rv;
+  int nfds = 0;
+  fd_set wr_fdset, rd_fdset;
+  fd_set _wfdset, *wfdset = &_wfdset;
+  fd_set _rfdset, *rfdset = (test == VCL_TEST_TYPE_BI) ? &_rfdset : 0;
+
+  ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+  ctrl->cfg.ctrl_handle = ~0;
+
+  printf ("\n" SOCK_TEST_BANNER_STRING
+	  "CLIENT (fd %d): %s-directional Stream Test!\n\n"
+	  "CLIENT (fd %d): Sending config to server on ctrl socket...\n",
+	  ctrl->fd, test == VCL_TEST_TYPE_BI ? "Bi" : "Uni", ctrl->fd);
+
+  if (sock_test_cfg_sync (ctrl))
+    {
+      fprintf (stderr, "CLIENT: ERROR: test cfg sync failed -- aborting!");
+      return;
+    }
+
+  FD_ZERO (&wr_fdset);
+  FD_ZERO (&rd_fdset);
+  memset (&ctrl->stats, 0, sizeof (ctrl->stats));
+  for (n = 0; n != ctrl->cfg.num_test_sessions; n++)
+    {
+      tsock = &scm->test_socket[n];
+      tsock->cfg = ctrl->cfg;
+      vcl_test_session_buf_alloc (tsock);
+      printf ("CLIENT (fd %d): Sending config to server on "
+	      "test socket %d...\n", tsock->fd, n);
+      sock_test_cfg_sync (tsock);
+
+      /* Fill payload with incrementing uint32's */
+      for (i = 0; i < tsock->txbuf_size; i++)
+	tsock->txbuf[i] = i & 0xff;
+
+      memset (&tsock->stats, 0, sizeof (tsock->stats));
+      FD_SET (tsock->fd, &wr_fdset);
+      FD_SET (tsock->fd, &rd_fdset);
+      nfds = ((tsock->fd + 1) > nfds) ? (tsock->fd + 1) : nfds;
+    }
+
+  nfds++;
+  clock_gettime (CLOCK_REALTIME, &ctrl->stats.start);
+  while (n)
+    {
+      _wfdset = wr_fdset;
+      _rfdset = rd_fdset;
+
+#ifdef VCL_TEST
+      rv =
+	vppcom_select (nfds, (unsigned long *) rfdset,
+		       (unsigned long *) wfdset, NULL, 0);
+#else
+      {
+	struct timeval timeout;
+	timeout.tv_sec = 0;
+	timeout.tv_usec = 0;
+	rv = select (nfds, rfdset, wfdset, NULL, &timeout);
+      }
+#endif
+      if (rv < 0)
+	{
+	  perror ("select()");
+	  fprintf (stderr, "\nCLIENT: ERROR: select() failed -- "
+		   "aborting test!\n");
+	  return;
+	}
+      else if (rv == 0)
+	continue;
+
+      for (i = 0; i < ctrl->cfg.num_test_sessions; i++)
+	{
+	  tsock = &scm->test_socket[i];
+	  if (!((tsock->stats.stop.tv_sec == 0) &&
+		(tsock->stats.stop.tv_nsec == 0)))
+	    continue;
+
+	  if ((test == VCL_TEST_TYPE_BI) &&
+	      FD_ISSET (tsock->fd, rfdset) &&
+	      (tsock->stats.rx_bytes < ctrl->cfg.total_bytes))
+	    {
+	      (void) sock_test_read (tsock->fd,
+				     (uint8_t *) tsock->rxbuf,
+				     tsock->rxbuf_size, &tsock->stats);
+	    }
+
+	  if (FD_ISSET (tsock->fd, wfdset) &&
+	      (tsock->stats.tx_bytes < ctrl->cfg.total_bytes))
+	    {
+	      tx_bytes = sock_test_write (tsock->fd, (uint8_t *) tsock->txbuf,
+					  ctrl->cfg.txbuf_size, &tsock->stats,
+					  ctrl->cfg.verbose);
+	      if (tx_bytes < 0)
+		{
+		  fprintf (stderr, "\nCLIENT: ERROR: sock_test_write(%d) "
+			   "failed -- aborting test!\n", tsock->fd);
+		  return;
+		}
+	    }
+
+	  if (((test == VCL_TEST_TYPE_UNI) &&
+	       (tsock->stats.tx_bytes >= ctrl->cfg.total_bytes)) ||
+	      ((test == VCL_TEST_TYPE_BI) &&
+	       (tsock->stats.rx_bytes >= ctrl->cfg.total_bytes)))
+	    {
+	      clock_gettime (CLOCK_REALTIME, &tsock->stats.stop);
+	      n--;
+	    }
+	}
+    }
+  clock_gettime (CLOCK_REALTIME, &ctrl->stats.stop);
+
+  printf ("CLIENT (fd %d): Sending config to server on ctrl socket...\n",
+	  ctrl->fd);
+
+  if (sock_test_cfg_sync (ctrl))
+    {
+      fprintf (stderr, "CLIENT: ERROR: test cfg sync failed -- aborting!");
+      return;
+    }
+
+  for (i = 0; i < ctrl->cfg.num_test_sessions; i++)
+    {
+      tsock = &scm->test_socket[i];
+
+      if (ctrl->cfg.verbose)
+	{
+	  static char buf[64];
+
+	  sprintf (buf, "CLIENT (fd %d) RESULTS", tsock->fd);
+	  vcl_test_stats_dump (buf, &tsock->stats,
+			       test == VCL_TEST_TYPE_BI /* show_rx */ ,
+			       1 /* show tx */ , ctrl->cfg.verbose);
+	}
+
+      vcl_test_stats_accumulate (&ctrl->stats, &tsock->stats);
+    }
+
+  vcl_test_stats_dump ("CLIENT RESULTS", &ctrl->stats,
+		       test == VCL_TEST_TYPE_BI /* show_rx */ ,
+		       1 /* show tx */ , ctrl->cfg.verbose);
+  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+
+  if (ctrl->cfg.verbose)
+    {
+      printf ("  ctrl socket info\n"
+	      VCL_TEST_SEPARATOR_STRING
+	      "          fd:  %d (0x%08x)\n"
+	      "       rxbuf:  %p\n"
+	      "  rxbuf size:  %u (0x%08x)\n"
+	      "       txbuf:  %p\n"
+	      "  txbuf size:  %u (0x%08x)\n"
+	      VCL_TEST_SEPARATOR_STRING,
+	      ctrl->fd, (uint32_t) ctrl->fd,
+	      ctrl->rxbuf, ctrl->rxbuf_size, ctrl->rxbuf_size,
+	      ctrl->txbuf, ctrl->txbuf_size, ctrl->txbuf_size);
+    }
+
+  ctrl->cfg.test = VCL_TEST_TYPE_ECHO;
+  if (sock_test_cfg_sync (ctrl))
+    fprintf (stderr, "CLIENT: ERROR: post-test cfg sync failed!");
+
+  printf ("CLIENT (fd %d): %s-directional Stream Test Complete!\n"
+	  SOCK_TEST_BANNER_STRING "\n", ctrl->fd,
+	  test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");
+}
+
+static void
+exit_client (void)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  vcl_test_session_t *tsock;
+  int i;
+
+#ifndef VCL_TEST
+  printf ("CLIENT: af_unix_echo_tx %d, af_unix_echo_rx %d\n",
+	  scm->af_unix_echo_tx, scm->af_unix_echo_rx);
+#endif
+  for (i = 0; i < ctrl->cfg.num_test_sessions; i++)
+    {
+      tsock = &scm->test_socket[i];
+      tsock->cfg.test = VCL_TEST_TYPE_EXIT;
+
+      /* coverity[COPY_PASTE_ERROR] */
+      if (ctrl->cfg.verbose)
+	{
+	  printf ("\nCLIENT (fd %d): Sending exit cfg to server...\n",
+		  tsock->fd);
+	  vcl_test_cfg_dump (&tsock->cfg, 1 /* is_client */ );
+	}
+      (void) sock_test_write (tsock->fd, (uint8_t *) & tsock->cfg,
+			      sizeof (tsock->cfg), &tsock->stats,
+			      ctrl->cfg.verbose);
+    }
+
+  ctrl->cfg.test = VCL_TEST_TYPE_EXIT;
+  if (ctrl->cfg.verbose)
+    {
+      printf ("\nCLIENT (fd %d): Sending exit cfg to server...\n", ctrl->fd);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  (void) sock_test_write (ctrl->fd, (uint8_t *) & ctrl->cfg,
+			  sizeof (ctrl->cfg), &ctrl->stats,
+			  ctrl->cfg.verbose);
+  printf ("\nCLIENT: So long and thanks for all the fish!\n\n");
+  sleep (1);
+}
+
+static int
+sock_test_connect_test_sockets (uint32_t num_test_sockets)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  vcl_test_session_t *tsock;
+  int i, rv, errno_val;
+
+  if (num_test_sockets < 1)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  if (num_test_sockets < scm->num_test_sockets)
+    {
+      for (i = scm->num_test_sockets - 1; i >= num_test_sockets; i--)
+	{
+	  tsock = &scm->test_socket[i];
+#ifdef VCL_TEST
+	  vppcom_session_close (tsock->fd);
+#else
+	  close (tsock->fd);
+#endif
+	  free (tsock->txbuf);
+	  free (tsock->rxbuf);
+	}
+    }
+
+  else if (num_test_sockets > scm->num_test_sockets)
+    {
+      tsock = realloc (scm->test_socket,
+		       sizeof (vcl_test_session_t) * num_test_sockets);
+      if (!tsock)
+	{
+	  errno_val = errno;
+	  perror ("ERROR in sock_test_connect_test_sockets()");
+	  fprintf (stderr, "CLIENT: ERROR: socket failed (errno = %d)!\n",
+		   errno_val);
+	  return -1;
+	}
+
+      if (!scm->test_socket)
+	memset (tsock, 0, sizeof (*tsock));
+
+      scm->test_socket = tsock;
+      for (i = scm->num_test_sockets; i < num_test_sockets; i++)
+	{
+	  tsock = &scm->test_socket[i];
+#ifdef VCL_TEST
+	  tsock->fd = vppcom_session_create (ctrl->cfg.transport_udp ?
+					     VPPCOM_PROTO_UDP :
+					     VPPCOM_PROTO_TCP,
+					     1 /* is_nonblocking */ );
+	  if (tsock->fd < 0)
+	    {
+	      errno = -tsock->fd;
+	      tsock->fd = -1;
+	    }
+#else
+	  tsock->fd = socket (ctrl->cfg.address_ip6 ? AF_INET6 : AF_INET,
+			      ctrl->cfg.transport_udp ?
+			      SOCK_DGRAM : SOCK_STREAM, 0);
+#endif
+	  if (tsock->fd < 0)
+	    {
+	      errno_val = errno;
+	      perror ("ERROR in sock_test_connect_test_sockets()");
+	      fprintf (stderr, "CLIENT: ERROR: socket failed (errno = %d)!\n",
+		       errno_val);
+	      return tsock->fd;
+	    }
+	  if (fcntl (tsock->fd, F_SETFL, O_NONBLOCK) < 0)
+	    {
+	      errno_val = errno;
+	      perror ("ERROR in sock_test_connect_test_sockets()");
+	      fprintf (stderr, "CLIENT: ERROR: fcntl failed (errno = %d)!\n",
+		       errno_val);
+	      return -1;
+	    }
+
+#ifdef VCL_TEST
+	  rv = vppcom_session_connect (tsock->fd, &scm->server_endpt);
+	  if (rv)
+	    {
+	      errno = -rv;
+	      rv = -1;
+	    }
+#else
+	  rv =
+	    connect (tsock->fd, (struct sockaddr *) &scm->server_addr,
+		     scm->server_addr_size);
+#endif
+	  if (rv < 0)
+	    {
+	      errno_val = errno;
+	      perror ("ERROR in sock_test_connect_test_sockets()");
+	      fprintf (stderr, "CLIENT: ERROR: connect failed "
+		       "(errno = %d)!\n", errno_val);
+	      return -1;
+	    }
+	  tsock->cfg = ctrl->cfg;
+	  vcl_test_session_buf_alloc (tsock);
+	  sock_test_cfg_sync (tsock);
+
+	  printf ("CLIENT (fd %d): Test socket %d connected.\n",
+		  tsock->fd, i);
+	}
+    }
+
+  scm->num_test_sockets = num_test_sockets;
+  printf ("CLIENT: All sockets (%d) connected!\n", scm->num_test_sockets + 1);
+  return 0;
+}
+
+static void
+dump_help (void)
+{
+#define INDENT "\n  "
+
+  printf ("CLIENT: Test configuration commands:"
+	  INDENT VCL_TEST_TOKEN_HELP
+	  "\t\t\tDisplay help."
+	  INDENT VCL_TEST_TOKEN_EXIT
+	  "\t\t\tExit test client & server."
+	  INDENT VCL_TEST_TOKEN_SHOW_CFG
+	  "\t\t\tShow the current test cfg."
+	  INDENT VCL_TEST_TOKEN_RUN_UNI
+	  "\t\t\tRun the Uni-directional test."
+	  INDENT VCL_TEST_TOKEN_RUN_BI
+	  "\t\t\tRun the Bi-directional test."
+	  INDENT VCL_TEST_TOKEN_VERBOSE
+	  "\t\t\tToggle verbose setting."
+	  INDENT VCL_TEST_TOKEN_RXBUF_SIZE
+	  "<rxbuf size>\tRx buffer size (bytes)."
+	  INDENT VCL_TEST_TOKEN_TXBUF_SIZE
+	  "<txbuf size>\tTx buffer size (bytes)."
+	  INDENT VCL_TEST_TOKEN_NUM_WRITES
+	  "<# of writes>\tNumber of txbuf writes to server." "\n");
+}
+
+static void
+cfg_txbuf_size_set (void)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_TXBUF_SIZE);
+  uint64_t txbuf_size = strtoull ((const char *) p, NULL, 10);
+
+  if (txbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+    {
+      ctrl->cfg.txbuf_size = txbuf_size;
+      ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+      vcl_test_buf_alloc (&ctrl->cfg, 0 /* is_rxbuf */ ,
+			  (uint8_t **) & ctrl->txbuf, &ctrl->txbuf_size);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    fprintf (stderr, "CLIENT: ERROR: Invalid txbuf size (%lu) < "
+	     "minimum buf size (%u)!\n",
+	     txbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+}
+
+static void
+cfg_num_writes_set (void)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_NUM_WRITES);
+  uint32_t num_writes = strtoul ((const char *) p, NULL, 10);
+
+  if (num_writes > 0)
+    {
+      ctrl->cfg.num_writes = num_writes;
+      ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    {
+      fprintf (stderr, "CLIENT: ERROR: invalid num writes: %u\n", num_writes);
+    }
+}
+
+static void
+cfg_num_test_sockets_set (void)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_NUM_TEST_SESS);
+  uint32_t num_test_sockets = strtoul ((const char *) p, NULL, 10);
+
+  if ((num_test_sockets > 0) &&
+      (num_test_sockets <= VCL_TEST_CFG_MAX_TEST_SESS))
+    {
+      ctrl->cfg.num_test_sessions = num_test_sockets;
+      sock_test_connect_test_sockets (num_test_sockets);
+
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    {
+      fprintf (stderr, "CLIENT: ERROR: invalid num test sockets: "
+	       "%u, (%d max)\n",
+	       num_test_sockets, VCL_TEST_CFG_MAX_TEST_SESS);
+    }
+}
+
+static void
+cfg_rxbuf_size_set (void)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_RXBUF_SIZE);
+  uint64_t rxbuf_size = strtoull ((const char *) p, NULL, 10);
+
+  if (rxbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+    {
+      ctrl->cfg.rxbuf_size = rxbuf_size;
+      vcl_test_buf_alloc (&ctrl->cfg, 1 /* is_rxbuf */ ,
+			  (uint8_t **) & ctrl->rxbuf, &ctrl->rxbuf_size);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    fprintf (stderr, "CLIENT: ERROR: Invalid rxbuf size (%lu) < "
+	     "minimum buf size (%u)!\n",
+	     rxbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+}
+
+static void
+cfg_verbose_toggle (void)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+
+  ctrl->cfg.verbose = ctrl->cfg.verbose ? 0 : 1;
+  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+
+}
+
+static vcl_test_t
+parse_input ()
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  vcl_test_t rv = VCL_TEST_TYPE_NONE;
+
+  if (!strncmp (VCL_TEST_TOKEN_EXIT, ctrl->txbuf,
+		strlen (VCL_TEST_TOKEN_EXIT)))
+    rv = VCL_TEST_TYPE_EXIT;
+
+  else if (!strncmp (VCL_TEST_TOKEN_HELP, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_HELP)))
+    dump_help ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_SHOW_CFG, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_SHOW_CFG)))
+    scm->dump_cfg = 1;
+
+  else if (!strncmp (VCL_TEST_TOKEN_VERBOSE, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_VERBOSE)))
+    cfg_verbose_toggle ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_TXBUF_SIZE, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_TXBUF_SIZE)))
+    cfg_txbuf_size_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_NUM_TEST_SESS, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_NUM_TEST_SESS)))
+    cfg_num_test_sockets_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_NUM_WRITES, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_NUM_WRITES)))
+    cfg_num_writes_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_RXBUF_SIZE, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_RXBUF_SIZE)))
+    cfg_rxbuf_size_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_RUN_UNI, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_RUN_UNI)))
+    rv = ctrl->cfg.test = VCL_TEST_TYPE_UNI;
+
+  else if (!strncmp (VCL_TEST_TOKEN_RUN_BI, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_RUN_BI)))
+    rv = ctrl->cfg.test = VCL_TEST_TYPE_BI;
+
+  else
+    rv = VCL_TEST_TYPE_ECHO;
+
+  return rv;
+}
+
+void
+print_usage_and_exit (void)
+{
+  fprintf (stderr,
+	   "sock_test_client [OPTIONS] <ipaddr> <port>\n"
+	   "  OPTIONS\n"
+	   "  -h               Print this message and exit.\n"
+	   "  -6               Use IPv6\n"
+	   "  -u               Use UDP transport layer\n"
+	   "  -c               Print test config before test.\n"
+	   "  -w <dir>         Write test results to <dir>.\n"
+	   "  -X               Exit after running test.\n"
+	   "  -E               Run Echo test.\n"
+	   "  -N <num-writes>  Test Cfg: number of writes.\n"
+	   "  -R <rxbuf-size>  Test Cfg: rx buffer size.\n"
+	   "  -T <txbuf-size>  Test Cfg: tx buffer size.\n"
+	   "  -U               Run Uni-directional test.\n"
+	   "  -B               Run Bi-directional test.\n"
+	   "  -V               Verbose mode.\n");
+  exit (1);
+}
+
+int
+main (int argc, char **argv)
+{
+  sock_client_main_t *scm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &scm->ctrl_socket;
+  int c, rv, errno_val;
+  vcl_test_t post_test = VCL_TEST_TYPE_NONE;
+
+  vcl_test_cfg_init (&ctrl->cfg);
+  vcl_test_session_buf_alloc (ctrl);
+
+  opterr = 0;
+  while ((c = getopt (argc, argv, "chn:w:XE:I:N:R:T:UBV6D")) != -1)
+    switch (c)
+      {
+      case 'c':
+	scm->dump_cfg = 1;
+	break;
+
+      case 's':
+	if (sscanf (optarg, "0x%x", &ctrl->cfg.num_test_sessions) != 1)
+	  if (sscanf (optarg, "%u", &ctrl->cfg.num_test_sessions) != 1)
+	    {
+	      fprintf (stderr, "CLIENT: ERROR: Invalid value for "
+		       "option -%c!\n", c);
+	      print_usage_and_exit ();
+	    }
+	if (!ctrl->cfg.num_test_sessions ||
+	    (ctrl->cfg.num_test_sessions > FD_SETSIZE))
+	  {
+	    fprintf (stderr, "CLIENT: ERROR: Invalid number of "
+		     "sockets (%d) specified for option -%c!\n"
+		     "       Valid range is 1 - %d\n",
+		     ctrl->cfg.num_test_sessions, c, FD_SETSIZE);
+	    print_usage_and_exit ();
+	  }
+	break;
+
+      case 'w':
+	fprintf (stderr, "CLIENT: Writing test results to files is TBD.\n");
+	break;
+
+      case 'X':
+	post_test = VCL_TEST_TYPE_EXIT;
+	break;
+
+      case 'E':
+	if (strlen (optarg) > ctrl->txbuf_size)
+	  {
+	    fprintf (stderr, "CLIENT: ERROR: Option -%c value "
+		     "larger than txbuf size (%d)!\n",
+		     optopt, ctrl->txbuf_size);
+	    print_usage_and_exit ();
+	  }
+	strcpy (ctrl->txbuf, optarg);
+	ctrl->cfg.test = VCL_TEST_TYPE_ECHO;
+	break;
+
+      case 'I':
+	if (sscanf (optarg, "0x%x", &ctrl->cfg.num_test_sessions) != 1)
+	  if (sscanf (optarg, "%d", &ctrl->cfg.num_test_sessions) != 1)
+	    {
+	      fprintf (stderr, "CLIENT: ERROR: Invalid value for "
+		       "option -%c!\n", c);
+	      print_usage_and_exit ();
+	    }
+	if (ctrl->cfg.num_test_sessions > VCL_TEST_CFG_MAX_TEST_SESS)
+	  {
+	    fprintf (stderr, "CLIENT: ERROR: value greater than max "
+		     "number test sockets (%d)!", VCL_TEST_CFG_MAX_TEST_SESS);
+	    print_usage_and_exit ();
+	  }
+	break;
+
+      case 'N':
+	if (sscanf (optarg, "0x%lx", &ctrl->cfg.num_writes) != 1)
+	  if (sscanf (optarg, "%ld", &ctrl->cfg.num_writes) != 1)
+	    {
+	      fprintf (stderr, "CLIENT: ERROR: Invalid value for "
+		       "option -%c!\n", c);
+	      print_usage_and_exit ();
+	    }
+	ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+	break;
+
+      case 'R':
+	if (sscanf (optarg, "0x%lx", &ctrl->cfg.rxbuf_size) != 1)
+	  if (sscanf (optarg, "%ld", &ctrl->cfg.rxbuf_size) != 1)
+	    {
+	      fprintf (stderr, "CLIENT: ERROR: Invalid value for "
+		       "option -%c!\n", c);
+	      print_usage_and_exit ();
+	    }
+	if (ctrl->cfg.rxbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+	  {
+	    ctrl->rxbuf_size = ctrl->cfg.rxbuf_size;
+	    vcl_test_buf_alloc (&ctrl->cfg, 1 /* is_rxbuf */ ,
+				(uint8_t **) & ctrl->rxbuf,
+				&ctrl->rxbuf_size);
+	  }
+	else
+	  {
+	    fprintf (stderr, "CLIENT: ERROR: rxbuf size (%lu) "
+		     "less than minumum (%u)\n",
+		     ctrl->cfg.rxbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+	    print_usage_and_exit ();
+	  }
+
+	break;
+
+      case 'T':
+	if (sscanf (optarg, "0x%lx", &ctrl->cfg.txbuf_size) != 1)
+	  if (sscanf (optarg, "%ld", &ctrl->cfg.txbuf_size) != 1)
+	    {
+	      fprintf (stderr, "CLIENT: ERROR: Invalid value "
+		       "for option -%c!\n", c);
+	      print_usage_and_exit ();
+	    }
+	if (ctrl->cfg.txbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+	  {
+	    ctrl->txbuf_size = ctrl->cfg.txbuf_size;
+	    vcl_test_buf_alloc (&ctrl->cfg, 0 /* is_rxbuf */ ,
+				(uint8_t **) & ctrl->txbuf,
+				&ctrl->txbuf_size);
+	    ctrl->cfg.total_bytes =
+	      ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+	  }
+	else
+	  {
+	    fprintf (stderr, "CLIENT: ERROR: txbuf size (%lu) "
+		     "less than minumum (%u)!\n",
+		     ctrl->cfg.txbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+	    print_usage_and_exit ();
+	  }
+	break;
+
+      case 'U':
+	ctrl->cfg.test = VCL_TEST_TYPE_UNI;
+	break;
+
+      case 'B':
+	ctrl->cfg.test = VCL_TEST_TYPE_BI;
+	break;
+
+      case 'V':
+	ctrl->cfg.verbose = 1;
+	break;
+
+      case '6':
+	ctrl->cfg.address_ip6 = 1;
+	break;
+
+      case 'D':
+	ctrl->cfg.transport_udp = 1;
+	break;
+
+      case '?':
+	switch (optopt)
+	  {
+	  case 'E':
+	  case 'I':
+	  case 'N':
+	  case 'R':
+	  case 'T':
+	  case 'w':
+	    fprintf (stderr, "CLIENT: ERROR: Option -%c "
+		     "requires an argument.\n", optopt);
+	    break;
+
+	  default:
+	    if (isprint (optopt))
+	      fprintf (stderr, "CLIENT: ERROR: Unknown "
+		       "option `-%c'.\n", optopt);
+	    else
+	      fprintf (stderr, "CLIENT: ERROR: Unknown "
+		       "option character `\\x%x'.\n", optopt);
+	  }
+	/* fall thru */
+      case 'h':
+      default:
+	print_usage_and_exit ();
+      }
+
+  if (argc < (optind + 2))
+    {
+      fprintf (stderr, "CLIENT: ERROR: Insufficient number of arguments!\n");
+      print_usage_and_exit ();
+    }
+
+#ifdef VCL_TEST
+  ctrl->fd = vppcom_app_create ("vcl_test_client");
+  if (ctrl->fd < 0)
+    {
+      errno = -ctrl->fd;
+      ctrl->fd = -1;
+    }
+  else
+    {
+      ctrl->fd = vppcom_session_create (ctrl->cfg.transport_udp ?
+					VPPCOM_PROTO_UDP :
+					VPPCOM_PROTO_TCP,
+					0 /* is_nonblocking */ );
+      if (ctrl->fd < 0)
+	{
+	  errno = -ctrl->fd;
+	  ctrl->fd = -1;
+	}
+    }
+#else
+  ctrl->fd = socket (ctrl->cfg.address_ip6 ? AF_INET6 : AF_INET,
+		     ctrl->cfg.transport_udp ? SOCK_DGRAM : SOCK_STREAM, 0);
+#endif
+
+  if (ctrl->fd < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "CLIENT: ERROR: socket "
+	       "failed (errno = %d)!\n", errno_val);
+      return ctrl->fd;
+    }
+
+  memset (&scm->server_addr, 0, sizeof (scm->server_addr));
+  if (ctrl->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *server_addr =
+	(struct sockaddr_in6 *) &scm->server_addr;
+      scm->server_addr_size = sizeof (*server_addr);
+      server_addr->sin6_family = AF_INET6;
+      inet_pton (AF_INET6, argv[optind++], &(server_addr->sin6_addr));
+      server_addr->sin6_port = htons (atoi (argv[optind]));
+    }
+  else
+    {
+      struct sockaddr_in *server_addr =
+	(struct sockaddr_in *) &scm->server_addr;
+      scm->server_addr_size = sizeof (*server_addr);
+      server_addr->sin_family = AF_INET;
+      inet_pton (AF_INET, argv[optind++], &(server_addr->sin_addr));
+      server_addr->sin_port = htons (atoi (argv[optind]));
+    }
+
+#ifdef VCL_TEST
+  if (ctrl->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *server_addr =
+	(struct sockaddr_in6 *) &scm->server_addr;
+      scm->server_endpt.is_ip4 = 0;
+      scm->server_endpt.ip = (uint8_t *) & server_addr->sin6_addr;
+      scm->server_endpt.port = (uint16_t) server_addr->sin6_port;
+    }
+  else
+    {
+      struct sockaddr_in *server_addr =
+	(struct sockaddr_in *) &scm->server_addr;
+      scm->server_endpt.is_ip4 = 1;
+      scm->server_endpt.ip = (uint8_t *) & server_addr->sin_addr;
+      scm->server_endpt.port = (uint16_t) server_addr->sin_port;
+    }
+#endif
+
+  do
+    {
+      printf ("\nCLIENT: Connecting to server...\n");
+
+#ifdef VCL_TEST
+      rv = vppcom_session_connect (ctrl->fd, &scm->server_endpt);
+      if (rv)
+	{
+	  errno = -rv;
+	  rv = -1;
+	}
+#else
+      rv =
+	connect (ctrl->fd, (struct sockaddr *) &scm->server_addr,
+		 scm->server_addr_size);
+#endif
+      if (rv < 0)
+	{
+	  errno_val = errno;
+	  perror ("ERROR in main()");
+	  fprintf (stderr, "CLIENT: ERROR: connect failed (errno = %d)!\n",
+		   errno_val);
+	  return -1;
+	}
+
+      sock_test_cfg_sync (ctrl);
+      printf ("CLIENT (fd %d): Control socket connected.\n", ctrl->fd);
+    }
+  while (rv < 0);
+
+  sock_test_connect_test_sockets (ctrl->cfg.num_test_sessions);
+
+  while (ctrl->cfg.test != VCL_TEST_TYPE_EXIT)
+    {
+      if (scm->dump_cfg)
+	{
+	  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+	  scm->dump_cfg = 0;
+	}
+
+      switch (ctrl->cfg.test)
+	{
+	case VCL_TEST_TYPE_ECHO:
+	  echo_test_client ();
+	  break;
+
+	case VCL_TEST_TYPE_UNI:
+	case VCL_TEST_TYPE_BI:
+	  stream_test_client (ctrl->cfg.test);
+	  break;
+
+	case VCL_TEST_TYPE_EXIT:
+	  continue;
+
+	case VCL_TEST_TYPE_NONE:
+	default:
+	  break;
+	}
+      switch (post_test)
+	{
+	case VCL_TEST_TYPE_EXIT:
+	  switch (ctrl->cfg.test)
+	    {
+	    case VCL_TEST_TYPE_EXIT:
+	    case VCL_TEST_TYPE_UNI:
+	    case VCL_TEST_TYPE_BI:
+	    case VCL_TEST_TYPE_ECHO:
+	      ctrl->cfg.test = VCL_TEST_TYPE_EXIT;
+	      continue;
+
+	    case VCL_TEST_TYPE_NONE:
+	    default:
+	      break;
+	    }
+	  break;
+
+	case VCL_TEST_TYPE_NONE:
+	case VCL_TEST_TYPE_ECHO:
+	case VCL_TEST_TYPE_UNI:
+	case VCL_TEST_TYPE_BI:
+	default:
+	  break;
+	}
+
+      memset (ctrl->txbuf, 0, ctrl->txbuf_size);
+      memset (ctrl->rxbuf, 0, ctrl->rxbuf_size);
+
+      printf ("\nCLIENT: Type some characters and hit <return>\n"
+	      "('" VCL_TEST_TOKEN_HELP "' for help): ");
+
+      if (fgets (ctrl->txbuf, ctrl->txbuf_size, stdin) != NULL)
+	{
+	  if (strlen (ctrl->txbuf) == 1)
+	    {
+	      printf ("\nCLIENT: Nothing to send!  Please try again...\n");
+	      continue;
+	    }
+	  ctrl->txbuf[strlen (ctrl->txbuf) - 1] = 0;	// chomp the newline.
+
+	  /* Parse input for keywords */
+	  ctrl->cfg.test = parse_input ();
+	}
+    }
+
+  exit_client ();
+#ifdef VCL_TEST
+  vppcom_session_close (ctrl->fd);
+  vppcom_app_destroy ();
+  return 0;
+#else
+  close (ctrl->fd);
+  return (scm->af_unix_echo_tx == scm->af_unix_echo_rx) ? 0 : -1;
+#endif
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/hs_apps/vcl/sock_test_server.c b/src/plugins/hs_apps/vcl/sock_test_server.c
new file mode 100644
index 00000000000..59dae179cd8
--- /dev/null
+++ b/src/plugins/hs_apps/vcl/sock_test_server.c
@@ -0,0 +1,1015 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <ctype.h>
+#include <hs_apps/vcl/sock_test.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#define SOCK_SERVER_USE_EPOLL 1
+#define VPPCOM_SESSION_ATTR_UNIT_TEST 0
+
+#if SOCK_SERVER_USE_EPOLL
+#include <sys/epoll.h>
+#if !defined(VCL_TEST)
+#include <sys/un.h>
+#endif
+#endif
+
+#ifdef VCL_TEST
+#if VPPCOM_SESSION_ATTR_UNIT_TEST
+#define BUFLEN  sizeof (uint64_t) * 16
+uint64_t buffer[16];
+uint32_t buflen = BUFLEN;
+uint32_t *flags = (uint32_t *) buffer;
+#endif
+#endif
+
+typedef struct
+{
+  uint8_t is_alloc;
+  int fd;
+  uint8_t *buf;
+  uint32_t buf_size;
+  vcl_test_cfg_t cfg;
+  vcl_test_stats_t stats;
+#ifdef VCL_TEST
+  vppcom_endpt_t endpt;
+  uint8_t ip[16];
+#endif
+} sock_server_conn_t;
+
+typedef struct
+{
+  uint32_t port;
+  uint32_t address_ip6;
+  uint32_t transport_udp;
+} sock_server_cfg_t;
+
+#define SOCK_SERVER_MAX_TEST_CONN  10
+#define SOCK_SERVER_MAX_EPOLL_EVENTS 10
+typedef struct
+{
+  int listen_fd;
+  sock_server_cfg_t cfg;
+#if SOCK_SERVER_USE_EPOLL
+  int epfd;
+  struct epoll_event listen_ev;
+  struct epoll_event wait_events[SOCK_SERVER_MAX_EPOLL_EVENTS];
+#if !defined (VCL_TEST)
+  int af_unix_listen_fd;
+  int af_unix_fd;
+  struct epoll_event af_unix_listen_ev;
+  struct sockaddr_un serveraddr;
+  uint32_t af_unix_xacts;
+#endif
+#endif
+  size_t num_conn;
+  size_t conn_pool_size;
+  sock_server_conn_t *conn_pool;
+  int nfds;
+  fd_set rd_fdset;
+  fd_set wr_fdset;
+  struct timeval timeout;
+} sock_server_main_t;
+
+sock_server_main_t sock_server_main;
+
+#if ! SOCK_SERVER_USE_EPOLL
+static inline int
+get_nfds (void)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  int i, nfds;
+
+  for (nfds = i = 0; i < FD_SETSIZE; i++)
+    {
+      if (FD_ISSET (i, &ssm->rd_fdset) || FD_ISSET (i, &ssm->wr_fdset))
+	nfds = i + 1;
+    }
+  return nfds;
+}
+
+static inline void
+conn_fdset_set (sock_server_conn_t * conn, fd_set * fdset)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+
+  FD_SET (conn->fd, fdset);
+  ssm->nfds = get_nfds ();
+}
+
+static inline void
+conn_fdset_clr (sock_server_conn_t * conn, fd_set * fdset)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+
+  FD_CLR (conn->fd, fdset);
+  ssm->nfds = get_nfds ();
+}
+#endif
+
+static inline void
+conn_pool_expand (size_t expand_size)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  sock_server_conn_t *conn_pool;
+  size_t new_size = ssm->conn_pool_size + expand_size;
+  int i;
+
+  conn_pool = realloc (ssm->conn_pool, new_size * sizeof (*ssm->conn_pool));
+  if (conn_pool)
+    {
+      for (i = ssm->conn_pool_size; i < new_size; i++)
+	{
+	  sock_server_conn_t *conn = &conn_pool[i];
+	  memset (conn, 0, sizeof (*conn));
+	  vcl_test_cfg_init (&conn->cfg);
+	  vcl_test_buf_alloc (&conn->cfg, 1 /* is_rxbuf */ ,
+			      &conn->buf, &conn->buf_size);
+	  conn->cfg.txbuf_size = conn->cfg.rxbuf_size;
+	}
+
+      ssm->conn_pool = conn_pool;
+      ssm->conn_pool_size = new_size;
+    }
+  else
+    {
+      int errno_val = errno;
+      perror ("ERROR in conn_pool_expand()");
+      fprintf (stderr, "SERVER: ERROR: Memory allocation "
+	       "failed (errno = %d)!\n", errno_val);
+    }
+}
+
+static inline sock_server_conn_t *
+conn_pool_alloc (void)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  int i;
+
+  for (i = 0; i < ssm->conn_pool_size; i++)
+    {
+      if (!ssm->conn_pool[i].is_alloc)
+	{
+#ifdef VCL_TEST
+	  ssm->conn_pool[i].endpt.ip = ssm->conn_pool[i].ip;
+#endif
+	  ssm->conn_pool[i].is_alloc = 1;
+	  return (&ssm->conn_pool[i]);
+	}
+    }
+
+  return 0;
+}
+
+static inline void
+conn_pool_free (sock_server_conn_t * conn)
+{
+#if ! SOCK_SERVER_USE_EPOLL
+  sock_server_main_t *ssm = &sock_server_main;
+
+  conn_fdset_clr (conn, &ssm->rd_fdset);
+  conn_fdset_clr (conn, &ssm->wr_fdset);
+#endif
+  conn->fd = 0;
+  conn->is_alloc = 0;
+}
+
+static inline void
+sync_config_and_reply (sock_server_conn_t * conn, vcl_test_cfg_t * rx_cfg)
+{
+  conn->cfg = *rx_cfg;
+  vcl_test_buf_alloc (&conn->cfg, 1 /* is_rxbuf */ ,
+		      &conn->buf, &conn->buf_size);
+  conn->cfg.txbuf_size = conn->cfg.rxbuf_size;
+
+  if (conn->cfg.verbose)
+    {
+      printf ("\nSERVER (fd %d): Replying to cfg message!\n", conn->fd);
+      vcl_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
+    }
+  (void) sock_test_write (conn->fd, (uint8_t *) & conn->cfg,
+			  sizeof (conn->cfg), NULL, conn->cfg.verbose);
+}
+
+static void
+stream_test_server_start_stop (sock_server_conn_t * conn,
+			       vcl_test_cfg_t * rx_cfg)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  int client_fd = conn->fd;
+  vcl_test_t test = rx_cfg->test;
+
+  if (rx_cfg->ctrl_handle == conn->fd)
+    {
+      int i;
+      clock_gettime (CLOCK_REALTIME, &conn->stats.stop);
+
+      for (i = 0; i < ssm->conn_pool_size; i++)
+	{
+	  sock_server_conn_t *tc = &ssm->conn_pool[i];
+
+	  if (tc->cfg.ctrl_handle == conn->fd)
+	    {
+	      vcl_test_stats_accumulate (&conn->stats, &tc->stats);
+
+	      if (conn->cfg.verbose)
+		{
+		  static char buf[64];
+
+		  sprintf (buf, "SERVER (fd %d) RESULTS", tc->fd);
+		  vcl_test_stats_dump (buf, &tc->stats, 1 /* show_rx */ ,
+				       test == VCL_TEST_TYPE_BI
+				       /* show tx */ ,
+				       conn->cfg.verbose);
+		}
+	    }
+	}
+
+      vcl_test_stats_dump ("SERVER RESULTS", &conn->stats, 1 /* show_rx */ ,
+			   (test == VCL_TEST_TYPE_BI) /* show_tx */ ,
+			   conn->cfg.verbose);
+      vcl_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
+      if (conn->cfg.verbose)
+	{
+	  printf ("  sock server main\n"
+		  VCL_TEST_SEPARATOR_STRING
+		  "       buf:  %p\n"
+		  "  buf size:  %u (0x%08x)\n"
+		  VCL_TEST_SEPARATOR_STRING,
+		  conn->buf, conn->buf_size, conn->buf_size);
+	}
+
+      sync_config_and_reply (conn, rx_cfg);
+      printf ("\nSERVER (fd %d): %s-directional Stream Test Complete!\n"
+	      SOCK_TEST_BANNER_STRING "\n", conn->fd,
+	      test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");
+    }
+  else
+    {
+      printf ("\n" SOCK_TEST_BANNER_STRING
+	      "SERVER (fd %d): %s-directional Stream Test!\n"
+	      "  Sending client the test cfg to start streaming data...\n",
+	      client_fd, test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");
+
+      rx_cfg->ctrl_handle = (rx_cfg->ctrl_handle == ~0) ? conn->fd :
+	rx_cfg->ctrl_handle;
+
+      sync_config_and_reply (conn, rx_cfg);
+
+      /* read the 1st chunk, record start time */
+      memset (&conn->stats, 0, sizeof (conn->stats));
+      clock_gettime (CLOCK_REALTIME, &conn->stats.start);
+    }
+}
+
+
+static inline void
+stream_test_server (sock_server_conn_t * conn, int rx_bytes)
+{
+  int client_fd = conn->fd;
+  vcl_test_t test = conn->cfg.test;
+
+  if (test == VCL_TEST_TYPE_BI)
+    (void) sock_test_write (client_fd, conn->buf, rx_bytes, &conn->stats,
+			    conn->cfg.verbose);
+
+  if (conn->stats.rx_bytes >= conn->cfg.total_bytes)
+    {
+      clock_gettime (CLOCK_REALTIME, &conn->stats.stop);
+    }
+}
+
+#if SOCK_SERVER_USE_EPOLL && !defined (VCL_TEST)
+static inline void
+af_unix_echo (void)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  int af_unix_client_fd;
+  int rv;
+  int errno_val;
+  uint8_t buffer[256];
+  size_t nbytes = strlen (SOCK_TEST_MIXED_EPOLL_DATA) + 1;
+
+#if HAVE_ACCEPT4
+  af_unix_client_fd = accept4 (ssm->af_unix_listen_fd,
+			       (struct sockaddr *) NULL, NULL, NULL);
+#else
+  af_unix_client_fd = accept (ssm->af_unix_listen_fd,
+			      (struct sockaddr *) NULL, NULL);
+#endif
+  if (af_unix_client_fd < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in af_unix_accept()");
+      fprintf (stderr, "SERVER: ERROR: accept failed "
+	       "(errno = %d)!\n", errno_val);
+      return;
+    }
+
+  printf ("SERVER: Got an AF_UNIX connection -- fd = %d (0x%08x)!\n",
+	  af_unix_client_fd, af_unix_client_fd);
+
+  memset (buffer, 0, sizeof (buffer));
+
+  rv = read (af_unix_client_fd, buffer, nbytes);
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in af_unix_echo(): read() failed");
+      fprintf (stderr, "SERVER: ERROR: read(af_unix_client_fd %d (0x%x), "
+	       "\"%s\", nbytes %lu) failed (errno = %d)!\n",
+	       af_unix_client_fd, af_unix_client_fd, buffer, nbytes,
+	       errno_val);
+      goto done;
+    }
+
+  printf ("SERVER (AF_UNIX): RX (%d bytes) - '%s'\n", rv, buffer);
+
+  if (!strncmp (SOCK_TEST_MIXED_EPOLL_DATA, (const char *) buffer, nbytes))
+    {
+      rv = write (af_unix_client_fd, buffer, nbytes);
+      if (rv < 0)
+	{
+	  errno_val = errno;
+	  perror ("ERROR in af_unix_echo(): write() failed");
+	  fprintf (stderr,
+		   "SERVER: ERROR: write(af_unix_client_fd %d (0x%x), "
+		   "\"%s\", nbytes %ld) failed (errno = %d)!\n",
+		   af_unix_client_fd, af_unix_client_fd, buffer, nbytes,
+		   errno_val);
+	  goto done;
+	}
+      printf ("SERVER (AF_UNIX): TX (%d bytes) - '%s'\n", rv, buffer);
+      ssm->af_unix_xacts++;
+    }
+done:
+  close (af_unix_client_fd);
+}
+
+#endif
+
+static inline void
+new_client (void)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  int client_fd;
+  sock_server_conn_t *conn;
+
+  if (ssm->conn_pool_size < (ssm->num_conn + SOCK_SERVER_MAX_TEST_CONN + 1))
+    conn_pool_expand (SOCK_SERVER_MAX_TEST_CONN + 1);
+
+  conn = conn_pool_alloc ();
+  if (!conn)
+    {
+      fprintf (stderr, "\nSERVER: ERROR: No free connections!\n");
+      return;
+    }
+
+#ifdef VCL_TEST
+  client_fd = vppcom_session_accept (ssm->listen_fd, &conn->endpt, 0);
+  if (client_fd < 0)
+    errno = -client_fd;
+#elif HAVE_ACCEPT4
+  client_fd = accept4 (ssm->listen_fd, (struct sockaddr *) NULL, NULL, NULL);
+#else
+  client_fd = accept (ssm->listen_fd, (struct sockaddr *) NULL, NULL);
+#endif
+  if (client_fd < 0)
+    {
+      int errno_val;
+      errno_val = errno;
+      perror ("ERROR in new_client()");
+      fprintf (stderr, "SERVER: ERROR: accept failed "
+	       "(errno = %d)!\n", errno_val);
+      return;
+    }
+
+  printf ("SERVER: Got a connection -- fd = %d (0x%08x)!\n",
+	  client_fd, client_fd);
+
+  conn->fd = client_fd;
+
+#if ! SOCK_SERVER_USE_EPOLL
+  conn_fdset_set (conn, &ssm->rd_fdset);
+  ssm->nfds++;
+#else
+  {
+    struct epoll_event ev;
+    int rv;
+
+    ev.events = EPOLLIN;
+    ev.data.u64 = conn - ssm->conn_pool;
+#ifdef VCL_TEST
+    rv = vppcom_epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, client_fd, &ev);
+    if (rv)
+      errno = -rv;
+#else
+    rv = epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, client_fd, &ev);
+#endif
+    if (rv < 0)
+      {
+	int errno_val;
+	errno_val = errno;
+	perror ("ERROR in new_client()");
+	fprintf (stderr, "SERVER: ERROR: epoll_ctl failed (errno = %d)!\n",
+		 errno_val);
+      }
+    else
+      ssm->nfds++;
+  }
+#endif
+}
+
+void
+print_usage_and_exit (void)
+{
+  fprintf (stderr,
+	   "sock_test_server [OPTIONS] <port>\n"
+	   "  OPTIONS\n"
+	   "  -h               Print this message and exit.\n"
+	   "  -6               Use IPv6\n"
+	   "  -u               Use UDP transport layer\n");
+  exit (1);
+}
+
+int
+main (int argc, char **argv)
+{
+  sock_server_main_t *ssm = &sock_server_main;
+  int client_fd, rv, main_rv = 0;
+  int tx_bytes, rx_bytes, nbytes;
+  sock_server_conn_t *conn;
+  vcl_test_cfg_t *rx_cfg;
+  uint32_t xtra = 0;
+  uint64_t xtra_bytes = 0;
+  struct sockaddr_storage servaddr;
+  int errno_val;
+  int c, v, i;
+  uint16_t port = VCL_TEST_SERVER_PORT;
+#if ! SOCK_SERVER_USE_EPOLL
+  fd_set _rfdset, *rfdset = &_rfdset;
+#endif
+#ifdef VCL_TEST
+  vppcom_endpt_t endpt;
+#else
+  uint32_t servaddr_size;
+#if ! SOCK_SERVER_USE_EPOLL
+  fd_set _wfdset, *wfdset = &_wfdset;
+#endif
+#endif
+
+  opterr = 0;
+  while ((c = getopt (argc, argv, "6D")) != -1)
+    switch (c)
+      {
+      case '6':
+	ssm->cfg.address_ip6 = 1;
+	break;
+
+      case 'D':
+	ssm->cfg.transport_udp = 1;
+	break;
+
+      case '?':
+	switch (optopt)
+	  {
+	  default:
+	    if (isprint (optopt))
+	      fprintf (stderr, "SERVER: ERROR: Unknown "
+		       "option `-%c'.\n", optopt);
+	    else
+	      fprintf (stderr, "SERVER: ERROR: Unknown "
+		       "option character `\\x%x'.\n", optopt);
+	  }
+	/* fall thru */
+      case 'h':
+      default:
+	print_usage_and_exit ();
+      }
+
+  if (argc < (optind + 1))
+    {
+      fprintf (stderr, "SERVER: ERROR: Insufficient number of arguments!\n");
+      print_usage_and_exit ();
+    }
+
+  if (sscanf (argv[optind], "%d", &v) == 1)
+    port = (uint16_t) v;
+  else
+    {
+      fprintf (stderr, "SERVER: ERROR: Invalid port (%s)!\n", argv[optind]);
+      print_usage_and_exit ();
+    }
+
+  conn_pool_expand (SOCK_SERVER_MAX_TEST_CONN + 1);
+
+#ifdef VCL_TEST
+  rv = vppcom_app_create ("vcl_test_server");
+  if (rv)
+    {
+      errno = -rv;
+      ssm->listen_fd = -1;
+    }
+  else
+    {
+      ssm->listen_fd = vppcom_session_create (ssm->cfg.transport_udp ?
+					      VPPCOM_PROTO_UDP :
+					      VPPCOM_PROTO_TCP,
+					      0 /* is_nonblocking */ );
+    }
+#else
+  ssm->listen_fd = socket (ssm->cfg.address_ip6 ? AF_INET6 : AF_INET,
+			   ssm->cfg.transport_udp ? SOCK_DGRAM : SOCK_STREAM,
+			   0);
+#if SOCK_SERVER_USE_EPOLL && !defined (VCL_TEST)
+  unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
+  ssm->af_unix_listen_fd = socket (AF_UNIX, SOCK_STREAM, 0);
+  if (ssm->af_unix_listen_fd < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main(): socket(AF_UNIX) failed");
+      fprintf (stderr,
+	       "SERVER: ERROR: socket(AF_UNIX, SOCK_STREAM, 0) failed "
+	       "(errno = %d)!\n", errno_val);
+      return ssm->af_unix_listen_fd;
+    }
+
+  memset (&ssm->serveraddr, 0, sizeof (ssm->serveraddr));
+  ssm->serveraddr.sun_family = AF_UNIX;
+  strcpy (ssm->serveraddr.sun_path, SOCK_TEST_AF_UNIX_FILENAME);
+
+  rv = bind (ssm->af_unix_listen_fd, (struct sockaddr *) &ssm->serveraddr,
+	     SUN_LEN (&ssm->serveraddr));
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main(): bind(SOCK_TEST_AF_UNIX_FILENAME) failed");
+      fprintf (stderr, "SERVER: ERROR: bind() fd %d, \"%s\": "
+	       "failed (errno = %d)!\n", ssm->af_unix_listen_fd,
+	       SOCK_TEST_AF_UNIX_FILENAME, errno_val);
+      close (ssm->af_unix_listen_fd);
+      unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
+      return rv;
+    }
+
+  rv = listen (ssm->af_unix_listen_fd, 10);
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main(): listen(AF_UNIX) failed");
+      fprintf (stderr, "SERVER: ERROR: listen() fd %d, \"%s\": "
+	       "failed (errno = %d)!\n", ssm->af_unix_listen_fd,
+	       SOCK_TEST_AF_UNIX_FILENAME, errno_val);
+      close (ssm->af_unix_listen_fd);
+      unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
+      return rv;
+    }
+#endif /* SOCK_SERVER_USE_EPOLL */
+#endif
+  if (ssm->listen_fd < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "SERVER: ERROR: socket() failed "
+	       "(errno = %d)!\n", errno_val);
+      return ssm->listen_fd;
+    }
+
+  memset (&servaddr, 0, sizeof (servaddr));
+
+  if (ssm->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *server_addr = (struct sockaddr_in6 *) &servaddr;
+#ifndef VCL_TEST
+      servaddr_size = sizeof (*server_addr);
+#endif
+      server_addr->sin6_family = AF_INET6;
+      server_addr->sin6_addr = in6addr_any;
+      server_addr->sin6_port = htons (port);
+    }
+  else
+    {
+      struct sockaddr_in *server_addr = (struct sockaddr_in *) &servaddr;
+#ifndef VCL_TEST
+      servaddr_size = sizeof (*server_addr);
+#endif
+      server_addr->sin_family = AF_INET;
+      server_addr->sin_addr.s_addr = htonl (INADDR_ANY);
+      server_addr->sin_port = htons (port);
+    }
+
+#ifdef VCL_TEST
+  if (ssm->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *server_addr = (struct sockaddr_in6 *) &servaddr;
+      endpt.is_ip4 = 0;
+      endpt.ip = (uint8_t *) & server_addr->sin6_addr;
+      endpt.port = (uint16_t) server_addr->sin6_port;
+    }
+  else
+    {
+      struct sockaddr_in *server_addr = (struct sockaddr_in *) &servaddr;
+      endpt.is_ip4 = 1;
+      endpt.ip = (uint8_t *) & server_addr->sin_addr;
+      endpt.port = (uint16_t) server_addr->sin_port;
+    }
+
+  rv = vppcom_session_bind (ssm->listen_fd, &endpt);
+  if (rv)
+    {
+      errno = -rv;
+      rv = -1;
+    }
+#else
+  rv = bind (ssm->listen_fd, (struct sockaddr *) &servaddr, servaddr_size);
+#endif
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "SERVER: ERROR: bind failed (errno = %d)!\n",
+	       errno_val);
+      return rv;
+    }
+  if (fcntl (ssm->listen_fd, F_SETFL, O_NONBLOCK) < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "SERVER: ERROR: fcntl failed (errno = %d)!\n",
+	       errno_val);
+      return rv;
+    }
+
+#ifdef VCL_TEST
+  rv = vppcom_session_listen (ssm->listen_fd, 10);
+  if (rv)
+    {
+      errno = -rv;
+      rv = -1;
+    }
+#else
+  rv = listen (ssm->listen_fd, 10);
+#endif
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "SERVER: ERROR: listen failed "
+	       "(errno = %d)!\n", errno_val);
+      return rv;
+    }
+
+#if ! SOCK_SERVER_USE_EPOLL
+
+  FD_ZERO (&ssm->wr_fdset);
+  FD_ZERO (&ssm->rd_fdset);
+
+  FD_SET (ssm->listen_fd, &ssm->rd_fdset);
+  ssm->nfds = ssm->listen_fd + 1;
+
+#else
+#ifdef VCL_TEST
+  ssm->epfd = vppcom_epoll_create ();
+  if (ssm->epfd < 0)
+    errno = -ssm->epfd;
+#else
+  ssm->epfd = epoll_create (1);
+#endif
+  if (ssm->epfd < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "SERVER: ERROR: epoll_create failed (errno = %d)!\n",
+	       errno_val);
+      return ssm->epfd;
+    }
+
+  ssm->listen_ev.events = EPOLLIN;
+  ssm->listen_ev.data.u32 = ~0;
+#ifdef VCL_TEST
+  rv = vppcom_epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, ssm->listen_fd,
+			 &ssm->listen_ev);
+  if (rv < 0)
+    errno = -rv;
+#else
+  ssm->af_unix_listen_ev.events = EPOLLIN;
+  ssm->af_unix_listen_ev.data.u32 = SOCK_TEST_AF_UNIX_ACCEPT_DATA;
+  rv = epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, ssm->af_unix_listen_fd,
+		  &ssm->af_unix_listen_ev);
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main(): mixed epoll_ctl(EPOLL_CTL_ADD)");
+      fprintf (stderr, "SERVER: ERROR: mixed epoll_ctl(epfd %d (0x%x), "
+	       "EPOLL_CTL_ADD, af_unix_listen_fd %d (0x%x), EPOLLIN) failed "
+	       "(errno = %d)!\n", ssm->epfd, ssm->epfd,
+	       ssm->af_unix_listen_fd, ssm->af_unix_listen_fd, errno_val);
+      close (ssm->af_unix_listen_fd);
+      unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
+      return rv;
+    }
+
+  rv = epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, ssm->listen_fd, &ssm->listen_ev);
+#endif
+  if (rv < 0)
+    {
+      errno_val = errno;
+      perror ("ERROR in main()");
+      fprintf (stderr, "SERVER: ERROR: epoll_ctl failed "
+	       "(errno = %d)!\n", errno_val);
+      return rv;
+    }
+#endif
+
+  printf ("\nSERVER: Waiting for a client to connect on port %d...\n", port);
+
+  while (1)
+    {
+#if ! SOCK_SERVER_USE_EPOLL
+      _rfdset = ssm->rd_fdset;
+
+#ifdef VCL_TEST
+      rv = vppcom_select (ssm->nfds, (unsigned long *) rfdset, NULL, NULL, 0);
+#else
+      {
+	struct timeval timeout;
+	timeout = ssm->timeout;
+	_wfdset = ssm->wr_fdset;
+	rv = select (ssm->nfds, rfdset, wfdset, NULL, &timeout);
+      }
+#endif
+      if (rv < 0)
+	{
+	  perror ("select()");
+	  fprintf (stderr, "\nSERVER: ERROR: select() failed -- aborting!\n");
+	  main_rv = -1;
+	  goto done;
+	}
+      else if (rv == 0)
+	continue;
+
+      if (FD_ISSET (ssm->listen_fd, rfdset))
+	new_client ();
+
+      for (i = 0; i < ssm->conn_pool_size; i++)
+	{
+	  if (!ssm->conn_pool[i].is_alloc)
+	    continue;
+
+	  conn = &ssm->conn_pool[i];
+#else
+      int num_ev;
+#ifdef VCL_TEST
+      num_ev = vppcom_epoll_wait (ssm->epfd, ssm->wait_events,
+				  SOCK_SERVER_MAX_EPOLL_EVENTS, 60.0);
+      if (num_ev < 0)
+	errno = -num_ev;
+#else
+      num_ev = epoll_wait (ssm->epfd, ssm->wait_events,
+			   SOCK_SERVER_MAX_EPOLL_EVENTS, 60000);
+#endif
+      if (num_ev < 0)
+	{
+	  perror ("epoll_wait()");
+	  fprintf (stderr, "\nSERVER: ERROR: epoll_wait() "
+		   "failed -- aborting!\n");
+	  main_rv = -1;
+	  goto done;
+	}
+      if (num_ev == 0)
+	{
+	  fprintf (stderr, "\nSERVER: epoll_wait() timeout!\n");
+	  continue;
+	}
+      for (i = 0; i < num_ev; i++)
+	{
+	  conn = &ssm->conn_pool[ssm->wait_events[i].data.u32];
+	  if (ssm->wait_events[i].events & (EPOLLHUP | EPOLLRDHUP))
+	    {
+#ifdef VCL_TEST
+	      vppcom_session_close (conn->fd);
+#else
+	      close (conn->fd);
+#endif
+	      continue;
+	    }
+	  if (ssm->wait_events[i].data.u32 == ~0)
+	    {
+	      new_client ();
+	      continue;
+	    }
+#if !defined (VCL_TEST)
+	  else if (ssm->wait_events[i].data.u32 ==
+		   SOCK_TEST_AF_UNIX_ACCEPT_DATA)
+	    {
+	      af_unix_echo ();
+	      continue;
+	    }
+#endif
+#endif
+	  client_fd = conn->fd;
+
+#if ! SOCK_SERVER_USE_EPOLL
+	  if (FD_ISSET (client_fd, rfdset))
+#else
+	  if (EPOLLIN & ssm->wait_events[i].events)
+#endif
+	    {
+	    read_again:
+	      rx_bytes = sock_test_read (client_fd, conn->buf,
+					 conn->buf_size, &conn->stats);
+	      if (rx_bytes > 0)
+		{
+		  rx_cfg = (vcl_test_cfg_t *) conn->buf;
+		  if (rx_cfg->magic == VCL_TEST_CFG_CTRL_MAGIC)
+		    {
+		      if (rx_cfg->verbose)
+			{
+			  printf ("SERVER (fd %d): Received a cfg message!\n",
+				  client_fd);
+			  vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
+			}
+
+		      if (rx_bytes != sizeof (*rx_cfg))
+			{
+			  printf ("SERVER (fd %d): Invalid cfg message "
+				  "size (%d)!\n  Should be %lu bytes.\n",
+				  client_fd, rx_bytes, sizeof (*rx_cfg));
+			  conn->cfg.rxbuf_size = 0;
+			  conn->cfg.num_writes = 0;
+			  if (conn->cfg.verbose)
+			    {
+			      printf ("SERVER (fd %d): Replying to "
+				      "cfg message!\n", client_fd);
+			      vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
+			    }
+			  sock_test_write (client_fd, (uint8_t *) & conn->cfg,
+					   sizeof (conn->cfg), NULL,
+					   conn->cfg.verbose);
+			  continue;
+			}
+
+		      switch (rx_cfg->test)
+			{
+			case VCL_TEST_TYPE_NONE:
+			case VCL_TEST_TYPE_ECHO:
+			  sync_config_and_reply (conn, rx_cfg);
+			  break;
+
+			case VCL_TEST_TYPE_BI:
+			case VCL_TEST_TYPE_UNI:
+			  stream_test_server_start_stop (conn, rx_cfg);
+			  break;
+
+			case VCL_TEST_TYPE_EXIT:
+			  printf ("SERVER: Have a great day, "
+				  "connection %d!\n", client_fd);
+#ifdef VCL_TEST
+			  vppcom_session_close (client_fd);
+#else
+			  close (client_fd);
+#endif
+			  conn_pool_free (conn);
+			  printf ("SERVER: Closed client fd %d\n", client_fd);
+#if ! SOCK_SERVER_USE_EPOLL
+			  if (ssm->nfds == (ssm->listen_fd + 1))
+#else
+			  ssm->nfds--;
+			  if (!ssm->nfds)
+#endif
+			    {
+			      printf ("SERVER: All client connections "
+				      "closed.\n\nSERVER: "
+				      "May the force be with you!\n\n");
+			      goto done;
+			    }
+			  break;
+
+			default:
+			  fprintf (stderr,
+				   "SERVER: ERROR: Unknown test type!\n");
+			  vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
+			  break;
+			}
+		      continue;
+		    }
+
+		  else if ((conn->cfg.test == VCL_TEST_TYPE_UNI) ||
+			   (conn->cfg.test == VCL_TEST_TYPE_BI))
+		    {
+		      stream_test_server (conn, rx_bytes);
+		      if (ioctl (conn->fd, FIONREAD))
+			goto read_again;
+		      continue;
+		    }
+
+		  else if (isascii (conn->buf[0]))
+		    {
+		      // If it looks vaguely like a string, make sure it's terminated
+		      ((char *) conn->buf)[rx_bytes <
+					   conn->buf_size ? rx_bytes :
+					   conn->buf_size - 1] = 0;
+		      printf ("SERVER (fd %d): RX (%d bytes) - '%s'\n",
+			      conn->fd, rx_bytes, conn->buf);
+		    }
+		}
+	      else		// rx_bytes < 0
+		{
+		  if (errno == ECONNRESET)
+		    {
+		      printf ("\nSERVER: Connection reset by remote peer.\n"
+			      "  Y'all have a great day now!\n\n");
+		      break;
+		    }
+		  else
+		    continue;
+		}
+
+	      if (isascii (conn->buf[0]))
+		{
+		  /* If it looks vaguely like a string,
+		   * make sure it's terminated
+		   */
+		  ((char *) conn->buf)[rx_bytes <
+				       conn->buf_size ? rx_bytes :
+				       conn->buf_size - 1] = 0;
+		  if (xtra)
+		    fprintf (stderr, "SERVER: ERROR: "
+			     "FIFO not drained in previous test!\n"
+			     "       extra chunks %u (0x%x)\n"
+			     "        extra bytes %lu (0x%lx)\n",
+			     xtra, xtra, xtra_bytes, xtra_bytes);
+
+		  xtra = 0;
+		  xtra_bytes = 0;
+
+		  if (conn->cfg.verbose)
+		    printf ("SERVER (fd %d): Echoing back\n", client_fd);
+
+		  nbytes = strlen ((const char *) conn->buf) + 1;
+
+		  tx_bytes = sock_test_write (client_fd, conn->buf,
+					      nbytes, &conn->stats,
+					      conn->cfg.verbose);
+		  if (tx_bytes >= 0)
+		    printf ("SERVER (fd %d): TX (%d bytes) - '%s'\n",
+			    conn->fd, tx_bytes, conn->buf);
+		}
+
+	      else		// Extraneous read data from non-echo tests???
+		{
+		  xtra++;
+		  xtra_bytes += rx_bytes;
+		}
+	    }
+	}
+    }
+
+done:
+#ifdef VCL_TEST
+  vppcom_session_close (ssm->listen_fd);
+  vppcom_app_destroy ();
+#else
+  close (ssm->listen_fd);
+
+#if SOCK_SERVER_USE_EPOLL && !defined (VCL_TEST)
+  close (ssm->af_unix_listen_fd);
+  unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
+#endif /* SOCK_SERVER_USE_EPOLL */
+
+#endif
+  if (ssm->conn_pool)
+    free (ssm->conn_pool);
+
+  return main_rv;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/hs_apps/vcl/vcl_test.h b/src/plugins/hs_apps/vcl/vcl_test.h
new file mode 100644
index 00000000000..ab05f7ae9cf
--- /dev/null
+++ b/src/plugins/hs_apps/vcl/vcl_test.h
@@ -0,0 +1,538 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __vcl_test_h__
+#define __vcl_test_h__
+
+#include <netdb.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <vcl/vppcom.h>
+
+#define vtfail(_fn, _rv)						\
+{									\
+  errno = -_rv;								\
+  perror ("ERROR when calling " _fn);					\
+  fprintf (stderr, "\nERROR: " _fn " failed (errno = %d)!\n", -_rv);	\
+  exit (1);								\
+}
+
+#define vterr(_fn, _rv)							\
+{									\
+  errno = -_rv;								\
+  fprintf (stderr, "\nERROR: " _fn " failed (errno = %d)!\n", -_rv);	\
+}
+
+#define vtwrn(_fmt, _args...)						\
+  fprintf (stderr, "\nERROR: " _fmt "\n", ##_args)			\
+
+#define vtinf(_fmt, _args...)						\
+  fprintf (stdout, "vt<w%u>: " _fmt "\n", __wrk_index, ##_args)
+
+#define vt_atomic_add(_ptr, _val) 					\
+  __atomic_fetch_add (_ptr, _val, __ATOMIC_RELEASE)
+
+#define VCL_TEST_TOKEN_HELP           	"#H"
+#define VCL_TEST_TOKEN_EXIT           	"#X"
+#define VCL_TEST_TOKEN_VERBOSE        	"#V"
+#define VCL_TEST_TOKEN_TXBUF_SIZE     	"#T:"
+#define VCL_TEST_TOKEN_NUM_TEST_SESS 	"#I:"
+#define VCL_TEST_TOKEN_NUM_WRITES     	"#N:"
+#define VCL_TEST_TOKEN_RXBUF_SIZE     	"#R:"
+#define VCL_TEST_TOKEN_SHOW_CFG       	"#C"
+#define VCL_TEST_TOKEN_RUN_UNI        	"#U"
+#define VCL_TEST_TOKEN_RUN_BI         	"#B"
+
+#define VCL_TEST_SERVER_PORT         	22000
+#define VCL_TEST_LOCALHOST_IPADDR    	"127.0.0.1"
+
+#define VCL_TEST_CFG_CTRL_MAGIC      	0xfeedface
+#define VCL_TEST_CFG_NUM_WRITES_DEF  	1000000
+#define VCL_TEST_CFG_TXBUF_SIZE_DEF  	8192
+#define VCL_TEST_CFG_RXBUF_SIZE_DEF  	(64*VCL_TEST_CFG_TXBUF_SIZE_DEF)
+#define VCL_TEST_CFG_BUF_SIZE_MIN    	128
+#define VCL_TEST_CFG_MAX_TEST_SESS 	32
+#define VCL_TEST_CFG_MAX_EPOLL_EVENTS 	16
+
+#define VCL_TEST_DELAY_DISCONNECT	1
+#define VCL_TEST_SEPARATOR_STRING 	\
+  "  -----------------------------\n"
+typedef enum
+{
+  VCL_TEST_TYPE_NONE,
+  VCL_TEST_TYPE_ECHO,
+  VCL_TEST_TYPE_UNI,
+  VCL_TEST_TYPE_BI,
+  VCL_TEST_TYPE_EXIT,
+} vcl_test_t;
+
+typedef struct __attribute__ ((packed))
+{
+  uint32_t magic;
+  uint32_t seq_num;
+  uint32_t test;
+  uint32_t ctrl_handle;
+  uint32_t num_test_sessions;
+  uint32_t verbose;
+  uint32_t address_ip6;
+  uint32_t transport_udp;
+  uint32_t transport_tls;
+  uint64_t rxbuf_size;
+  uint64_t txbuf_size;
+  uint64_t num_writes;
+  uint64_t total_bytes;
+} vcl_test_cfg_t;
+
+typedef struct
+{
+  uint64_t rx_xacts;
+  uint64_t rx_bytes;
+  uint32_t rx_eagain;
+  uint32_t rx_incomp;
+  uint64_t tx_xacts;
+  uint64_t tx_bytes;
+  uint32_t tx_eagain;
+  uint32_t tx_incomp;
+  struct timespec start;
+  struct timespec stop;
+} vcl_test_stats_t;
+
+typedef struct
+{
+  int fd;
+  uint32_t txbuf_size;
+  char *txbuf;
+  uint32_t rxbuf_size;
+  char *rxbuf;
+  vcl_test_cfg_t cfg;
+  vcl_test_stats_t stats;
+} vcl_test_session_t;
+
+
+/*
+ * TLS server cert and keys to be used for testing only
+ */
+char vcl_test_crt_rsa[] =
+  "-----BEGIN CERTIFICATE-----\r\n"
+  "MIID5zCCAs+gAwIBAgIJALeMYCEHrTtJMA0GCSqGSIb3DQEBCwUAMIGJMQswCQYD\r\n"
+  "VQQGEwJVUzELMAkGA1UECAwCQ0ExETAPBgNVBAcMCFNhbiBKb3NlMQ4wDAYDVQQK\r\n"
+  "DAVDaXNjbzEOMAwGA1UECwwFZmQuaW8xFjAUBgNVBAMMDXRlc3R0bHMuZmQuaW8x\r\n"
+  "IjAgBgkqhkiG9w0BCQEWE3ZwcC1kZXZAbGlzdHMuZmQuaW8wHhcNMTgwMzA1MjEx\r\n"
+  "NTEyWhcNMjgwMzAyMjExNTEyWjCBiTELMAkGA1UEBhMCVVMxCzAJBgNVBAgMAkNB\r\n"
+  "MREwDwYDVQQHDAhTYW4gSm9zZTEOMAwGA1UECgwFQ2lzY28xDjAMBgNVBAsMBWZk\r\n"
+  "LmlvMRYwFAYDVQQDDA10ZXN0dGxzLmZkLmlvMSIwIAYJKoZIhvcNAQkBFhN2cHAt\r\n"
+  "ZGV2QGxpc3RzLmZkLmlvMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA\r\n"
+  "4C1k8a1DuStgggqT4o09fP9sJ2dC54bxhS/Xk2VEfaIZ222WSo4X/syRVfVy9Yah\r\n"
+  "cpI1zJ/RDxaZSFhgA+nPZBrFMsrULkrdAOpOVj8eDEp9JuWdO2ODSoFnCvLxcYWB\r\n"
+  "Yc5kHryJpEaGJl1sFQSesnzMFty/59ta0stk0Fp8r5NhIjWvSovGzPo6Bhz+VS2c\r\n"
+  "ebIZh4x1t2hHaFcgm0qJoJ6DceReWCW8w+yOVovTolGGq+bpb2Hn7MnRSZ2K2NdL\r\n"
+  "+aLXpkZbS/AODP1FF2vTO1mYL290LO7/51vJmPXNKSDYMy5EvILr5/VqtjsFCwRL\r\n"
+  "Q4jcM/+GeHSAFWx4qIv0BwIDAQABo1AwTjAdBgNVHQ4EFgQUWa1SOB37xmT53tZQ\r\n"
+  "aXuLLhRI7U8wHwYDVR0jBBgwFoAUWa1SOB37xmT53tZQaXuLLhRI7U8wDAYDVR0T\r\n"
+  "BAUwAwEB/zANBgkqhkiG9w0BAQsFAAOCAQEAoUht13W4ya27NVzQuCMvqPWL3VM4\r\n"
+  "3xbPFk02FaGz/WupPu276zGlzJAZrbuDcQowwwU1Ni1Yygxl96s1c2M5rHDTrOKG\r\n"
+  "rK0hbkSFBo+i6I8u4HiiQ4rYmG0Hv6+sXn3of0HsbtDPGgWZoipPWDljPYEURu3e\r\n"
+  "3HRe/Dtsj9CakBoSDzs8ndWaBR+f4sM9Tk1cjD46Gq2T/qpSPXqKxEUXlzhdCAn4\r\n"
+  "twub17Bq2kykHpppCwPg5M+v30tHG/R2Go15MeFWbEJthFk3TZMjKL7UFs7fH+x2\r\n"
+  "wSonXb++jY+KmCb93C+soABBizE57g/KmiR2IxQ/LMjDik01RSUIaM0lLA==\r\n"
+  "-----END CERTIFICATE-----\r\n";
+uint32_t vcl_test_crt_rsa_len = sizeof (vcl_test_crt_rsa);
+
+char vcl_test_key_rsa[] =
+  "-----BEGIN PRIVATE KEY-----\r\n"
+  "MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQDgLWTxrUO5K2CC\r\n"
+  "CpPijT18/2wnZ0LnhvGFL9eTZUR9ohnbbZZKjhf+zJFV9XL1hqFykjXMn9EPFplI\r\n"
+  "WGAD6c9kGsUyytQuSt0A6k5WPx4MSn0m5Z07Y4NKgWcK8vFxhYFhzmQevImkRoYm\r\n"
+  "XWwVBJ6yfMwW3L/n21rSy2TQWnyvk2EiNa9Ki8bM+joGHP5VLZx5shmHjHW3aEdo\r\n"
+  "VyCbSomgnoNx5F5YJbzD7I5Wi9OiUYar5ulvYefsydFJnYrY10v5otemRltL8A4M\r\n"
+  "/UUXa9M7WZgvb3Qs7v/nW8mY9c0pINgzLkS8guvn9Wq2OwULBEtDiNwz/4Z4dIAV\r\n"
+  "bHioi/QHAgMBAAECggEBAMzGipP8+oT166U+NlJXRFifFVN1DvdhG9PWnOxGL+c3\r\n"
+  "ILmBBC08WQzmHshPemBvR6DZkA1H23cV5JTiLWrFtC00CvhXsLRMrE5+uWotI6yE\r\n"
+  "iofybMroHvD6/X5R510UX9hQ6MHu5ShLR5VZ9zXHz5MpTmB/60jG5dLx+jgcwBK8\r\n"
+  "LuGv2YB/WCUwT9QJ3YU2eaingnXtz/MrFbkbltrqlnBdlD+kTtw6Yac9y1XuuQXc\r\n"
+  "BPeulLNDuPolJVWbUvDBZrpt2dXTgz8ws1sv+wCNE0xwQJsqW4Nx3QkpibUL9RUr\r\n"
+  "CVbKlNfa9lopT6nGKlgX69R/uH35yh9AOsfasro6w0ECgYEA82UJ8u/+ORah+0sF\r\n"
+  "Q0FfW5MTdi7OAUHOz16pUsGlaEv0ERrjZxmAkHA/VRwpvDBpx4alCv0Hc39PFLIk\r\n"
+  "nhSsM2BEuBkTAs6/GaoNAiBtQVE/hN7awNRWVmlieS0go3Y3dzaE9IUMyj8sPOFT\r\n"
+  "5JdJ6BM69PHKCkY3dKdnnfpFEuECgYEA68mRpteunF1mdZgXs+WrN+uLlRrQR20F\r\n"
+  "ZyMYiUCH2Dtn26EzA2moy7FipIIrQcX/j+KhYNGM3e7MU4LymIO29E18mn8JODnH\r\n"
+  "sQOXzBTsf8A4yIVMkcuQD3bfb0JiUGYUPOidTp2N7IJA7+6Yc3vQOyb74lnKnJoO\r\n"
+  "gougPT2wS+cCgYAn7muzb6xFsXDhyW0Tm6YJYBfRS9yAWEuVufINobeBZPSl2cN1\r\n"
+  "Jrnw+HlrfTNbrJWuJmjtZJXUXQ6cVp2rUbjutNyRV4vG6iRwEXYQ40EJdkr1gZpi\r\n"
+  "CHQhuShuuPih2MNAy7EEbM+sXrDjTBR3bFqzuHPzu7dp+BshCFX3lRfAAQKBgGQt\r\n"
+  "K5i7IhCFDjb/+3IPLgOAK7mZvsvZ4eXD33TQ2eZgtut1PXtBtNl17/b85uv293Fm\r\n"
+  "VDISVcsk3eLNS8zIiT6afUoWlxAwXEs0v5WRfjl4radkGvgGiJpJYvyeM67877RB\r\n"
+  "EDSKc/X8ESLfOB44iGvZUEMG6zJFscx9DgN25iQZAoGAbyd+JEWwdVH9/K3IH1t2\r\n"
+  "PBkZX17kNWv+iVM1WyFjbe++vfKZCrOJiyiqhDeEqgrP3AuNMlaaduC3VRC3G5oV\r\n"
+  "Mj1tlhDWQ/qhvKdCKNdIVQYDE75nw+FRWV8yYkHAnXYW3tNoweDIwixE0hkPR1bc\r\n"
+  "oEjPLVNtx8SOj/M4rhaPT3I=\r\n" "-----END PRIVATE KEY-----\r\n";
+uint32_t vcl_test_key_rsa_len = sizeof (vcl_test_key_rsa);
+
+static inline void
+vcl_test_stats_accumulate (vcl_test_stats_t * accum, vcl_test_stats_t * incr)
+{
+  accum->rx_xacts += incr->rx_xacts;
+  accum->rx_bytes += incr->rx_bytes;
+  accum->rx_eagain += incr->rx_eagain;
+  accum->rx_incomp += incr->rx_incomp;
+  accum->tx_xacts += incr->tx_xacts;
+  accum->tx_bytes += incr->tx_bytes;
+  accum->tx_eagain += incr->tx_eagain;
+  accum->tx_incomp += incr->tx_incomp;
+}
+
+static inline void
+vcl_test_cfg_init (vcl_test_cfg_t * cfg)
+{
+  cfg->magic = VCL_TEST_CFG_CTRL_MAGIC;
+  cfg->test = VCL_TEST_TYPE_NONE;
+  cfg->ctrl_handle = ~0;
+  cfg->num_test_sessions = 1;
+  cfg->verbose = 0;
+  cfg->rxbuf_size = VCL_TEST_CFG_RXBUF_SIZE_DEF;
+  cfg->num_writes = VCL_TEST_CFG_NUM_WRITES_DEF;
+  cfg->txbuf_size = VCL_TEST_CFG_TXBUF_SIZE_DEF;
+  cfg->total_bytes = cfg->num_writes * cfg->txbuf_size;
+}
+
+static inline int
+vcl_test_cfg_verify (vcl_test_cfg_t * cfg, vcl_test_cfg_t * valid_cfg)
+{
+  /* Note: txbuf & rxbuf on server are the same buffer,
+   *       so txbuf_size is not included in this check.
+   */
+  return ((cfg->magic == valid_cfg->magic)
+	  && (cfg->test == valid_cfg->test)
+	  && (cfg->verbose == valid_cfg->verbose)
+	  && (cfg->rxbuf_size == valid_cfg->rxbuf_size)
+	  && (cfg->num_writes == valid_cfg->num_writes)
+	  && (cfg->total_bytes == valid_cfg->total_bytes));
+}
+
+static inline void
+vcl_test_buf_alloc (vcl_test_cfg_t * cfg, uint8_t is_rxbuf, uint8_t ** buf,
+		    uint32_t * bufsize)
+{
+  uint32_t alloc_size = is_rxbuf ? cfg->rxbuf_size : cfg->txbuf_size;
+  uint8_t *lb = realloc (*buf, (size_t) alloc_size);
+
+  if (lb)
+    {
+      if (is_rxbuf)
+	cfg->rxbuf_size = *bufsize = alloc_size;
+      else
+	cfg->txbuf_size = *bufsize = alloc_size;
+
+      *buf = lb;
+    }
+  else
+    {
+      vtwrn ("realloc failed. using buffer size %d instead of %u",
+	     *bufsize, alloc_size);
+    }
+}
+
+static inline void
+vcl_test_session_buf_alloc (vcl_test_session_t * socket)
+{
+  socket->rxbuf_size = socket->cfg.rxbuf_size;
+  socket->txbuf_size = socket->cfg.txbuf_size;
+  vcl_test_buf_alloc (&socket->cfg, 0 /* is_rxbuf */ ,
+		      (uint8_t **) & socket->txbuf, &socket->txbuf_size);
+  vcl_test_buf_alloc (&socket->cfg, 1 /* is_rxbuf */ ,
+		      (uint8_t **) & socket->rxbuf, &socket->rxbuf_size);
+}
+
+static inline char *
+vcl_test_type_str (vcl_test_t t)
+{
+  switch (t)
+    {
+    case VCL_TEST_TYPE_NONE:
+      return "NONE";
+
+    case VCL_TEST_TYPE_ECHO:
+      return "ECHO";
+
+    case VCL_TEST_TYPE_UNI:
+      return "UNI";
+
+    case VCL_TEST_TYPE_BI:
+      return "BI";
+
+    case VCL_TEST_TYPE_EXIT:
+      return "EXIT";
+
+    default:
+      return "Unknown";
+    }
+}
+
+static inline void
+vcl_test_cfg_dump (vcl_test_cfg_t * cfg, uint8_t is_client)
+{
+  char *spc = "     ";
+
+  printf ("  test config (%p):\n"
+	  VCL_TEST_SEPARATOR_STRING
+	  "                 magic:  0x%08x\n"
+	  "               seq_num:  0x%08x\n"
+	  "%-5s             test:  %s (%d)\n"
+	  "           ctrl handle:  %d (0x%x)\n"
+	  "%-5s num test sockets:  %u (0x%08x)\n"
+	  "%-5s          verbose:  %s (%d)\n"
+	  "%-5s       rxbuf size:  %lu (0x%08lx)\n"
+	  "%-5s       txbuf size:  %lu (0x%08lx)\n"
+	  "%-5s       num writes:  %lu (0x%08lx)\n"
+	  "       client tx bytes:  %lu (0x%08lx)\n"
+	  VCL_TEST_SEPARATOR_STRING,
+	  (void *) cfg, cfg->magic, cfg->seq_num,
+	  is_client && (cfg->test == VCL_TEST_TYPE_UNI) ?
+	  "'" VCL_TEST_TOKEN_RUN_UNI "'" :
+	  is_client && (cfg->test == VCL_TEST_TYPE_BI) ?
+	  "'" VCL_TEST_TOKEN_RUN_BI "'" : spc,
+	  vcl_test_type_str (cfg->test), cfg->test,
+	  cfg->ctrl_handle, cfg->ctrl_handle,
+	  is_client ? "'" VCL_TEST_TOKEN_NUM_TEST_SESS "'" : spc,
+	  cfg->num_test_sessions, cfg->num_test_sessions,
+	  is_client ? "'" VCL_TEST_TOKEN_VERBOSE "'" : spc,
+	  cfg->verbose ? "on" : "off", cfg->verbose,
+	  is_client ? "'" VCL_TEST_TOKEN_RXBUF_SIZE "'" : spc,
+	  cfg->rxbuf_size, cfg->rxbuf_size,
+	  is_client ? "'" VCL_TEST_TOKEN_TXBUF_SIZE "'" : spc,
+	  cfg->txbuf_size, cfg->txbuf_size,
+	  is_client ? "'" VCL_TEST_TOKEN_NUM_WRITES "'" : spc,
+	  cfg->num_writes, cfg->num_writes,
+	  cfg->total_bytes, cfg->total_bytes);
+}
+
+static inline void
+vcl_test_stats_dump (char *header, vcl_test_stats_t * stats,
+		     uint8_t show_rx, uint8_t show_tx, uint8_t verbose)
+{
+  struct timespec diff;
+  double duration, rate;
+  uint64_t total_bytes;
+
+  if ((stats->stop.tv_nsec - stats->start.tv_nsec) < 0)
+    {
+      diff.tv_sec = stats->stop.tv_sec - stats->start.tv_sec - 1;
+      diff.tv_nsec = stats->stop.tv_nsec - stats->start.tv_nsec + 1e9;
+    }
+  else
+    {
+      diff.tv_sec = stats->stop.tv_sec - stats->start.tv_sec;
+      diff.tv_nsec = stats->stop.tv_nsec - stats->start.tv_nsec;
+    }
+  duration = (double) diff.tv_sec + (1e-9 * diff.tv_nsec);
+
+  total_bytes = stats->tx_bytes + stats->rx_bytes;
+  rate = (double) total_bytes *8 / duration / 1e9;
+  printf ("\n%s: Streamed %lu bytes\n"
+	  "  in %lf seconds (%lf Gbps %s-duplex)!\n",
+	  header, total_bytes, duration, rate,
+	  (show_rx && show_tx) ? "full" : "half");
+
+  if (show_tx)
+    {
+      printf (VCL_TEST_SEPARATOR_STRING
+	      "  tx stats (0x%p):\n"
+	      VCL_TEST_SEPARATOR_STRING
+	      "         writes:  %lu (0x%08lx)\n"
+	      "       tx bytes:  %lu (0x%08lx)\n"
+	      "      tx eagain:  %u (0x%08x)\n"
+	      "  tx incomplete:  %u (0x%08x)\n",
+	      (void *) stats, stats->tx_xacts, stats->tx_xacts,
+	      stats->tx_bytes, stats->tx_bytes,
+	      stats->tx_eagain, stats->tx_eagain,
+	      stats->tx_incomp, stats->tx_incomp);
+    }
+  if (show_rx)
+    {
+      printf (VCL_TEST_SEPARATOR_STRING
+	      "  rx stats (0x%p):\n"
+	      VCL_TEST_SEPARATOR_STRING
+	      "          reads:  %lu (0x%08lx)\n"
+	      "       rx bytes:  %lu (0x%08lx)\n"
+	      "      rx eagain:  %u (0x%08x)\n"
+	      "  rx incomplete:  %u (0x%08x)\n",
+	      (void *) stats, stats->rx_xacts, stats->rx_xacts,
+	      stats->rx_bytes, stats->rx_bytes,
+	      stats->rx_eagain, stats->rx_eagain,
+	      stats->rx_incomp, stats->rx_incomp);
+    }
+  if (verbose)
+    printf ("   start.tv_sec:  %ld\n"
+	    "  start.tv_nsec:  %ld\n"
+	    "    stop.tv_sec:  %ld\n"
+	    "   stop.tv_nsec:  %ld\n",
+	    stats->start.tv_sec, stats->start.tv_nsec,
+	    stats->stop.tv_sec, stats->stop.tv_nsec);
+
+  printf (VCL_TEST_SEPARATOR_STRING);
+}
+
+static inline int
+vcl_comp_tspec (struct timespec *a, struct timespec *b)
+{
+  if (a->tv_sec < b->tv_sec)
+    return -1;
+  else if (a->tv_sec > b->tv_sec)
+    return 1;
+  else if (a->tv_nsec < b->tv_nsec)
+    return -1;
+  else if (a->tv_nsec > b->tv_nsec)
+    return 1;
+  else
+    return 0;
+}
+
+static inline int
+vcl_test_read (int fd, uint8_t * buf, uint32_t nbytes,
+	       vcl_test_stats_t * stats)
+{
+  int rx_bytes;
+
+  do
+    {
+      if (stats)
+	stats->rx_xacts++;
+      rx_bytes = vppcom_session_read (fd, buf, nbytes);
+
+      if (rx_bytes < 0)
+	{
+	  errno = -rx_bytes;
+	  rx_bytes = -1;
+	}
+      if (stats)
+	{
+	  if ((rx_bytes == 0) ||
+	      ((rx_bytes < 0)
+	       && ((errno == EAGAIN) || (errno == EWOULDBLOCK))))
+	    stats->rx_eagain++;
+	  else if (rx_bytes < nbytes)
+	    stats->rx_incomp++;
+	}
+    }
+  while ((rx_bytes == 0) ||
+	 ((rx_bytes < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK))));
+
+  if (rx_bytes < 0)
+    {
+      vterr ("vppcom_session_read()", -errno);
+    }
+  else if (stats)
+    stats->rx_bytes += rx_bytes;
+
+  return (rx_bytes);
+}
+
+static inline int
+vcl_test_read_ds (int fd, vppcom_data_segments_t ds, vcl_test_stats_t * stats)
+{
+  int rx_bytes;
+
+  do
+    {
+      if (stats)
+	stats->rx_xacts++;
+      rx_bytes = vppcom_session_read_segments (fd, ds);
+
+      if (rx_bytes < 0)
+	{
+	  errno = -rx_bytes;
+	  rx_bytes = -1;
+	}
+      if (stats)
+	{
+	  if ((rx_bytes == 0) ||
+	      ((rx_bytes < 0)
+	       && ((errno == EAGAIN) || (errno == EWOULDBLOCK))))
+	    stats->rx_eagain++;
+	}
+    }
+  while ((rx_bytes == 0) ||
+	 ((rx_bytes < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK))));
+
+  if (rx_bytes < 0)
+    {
+      vterr ("vppcom_session_read()", -errno);
+    }
+  else if (stats)
+    stats->rx_bytes += rx_bytes;
+
+  return (rx_bytes);
+}
+
+static inline int
+vcl_test_write (int fd, uint8_t * buf, uint32_t nbytes,
+		vcl_test_stats_t * stats, uint32_t verbose)
+{
+  int tx_bytes = 0, nbytes_left = nbytes, rv;
+
+  do
+    {
+      if (stats)
+	stats->tx_xacts++;
+      rv = vppcom_session_write (fd, buf, nbytes_left);
+      if (rv < 0)
+	{
+	  errno = -rv;
+	  rv = -1;
+	}
+      if (rv < 0)
+	{
+	  if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
+	    {
+	      if (stats)
+		stats->tx_eagain++;
+	      break;
+	    }
+	  else
+	    break;
+	}
+      tx_bytes += rv;
+
+      if (tx_bytes != nbytes)
+	{
+	  nbytes_left = nbytes_left - rv;
+	  buf += rv;
+	  if (stats)
+	    stats->tx_incomp++;
+	}
+
+    }
+  while (tx_bytes != nbytes);
+
+  if (tx_bytes < 0)
+    {
+      vterr ("vpcom_session_write", -errno);
+    }
+  else if (stats)
+    stats->tx_bytes += tx_bytes;
+
+  return (tx_bytes);
+}
+
+#endif /* __vcl_test_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/hs_apps/vcl/vcl_test_client.c b/src/plugins/hs_apps/vcl/vcl_test_client.c
new file mode 100644
index 00000000000..1ead146aef5
--- /dev/null
+++ b/src/plugins/hs_apps/vcl/vcl_test_client.c
@@ -0,0 +1,1097 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <time.h>
+#include <arpa/inet.h>
+#include <hs_apps/vcl/vcl_test.h>
+#include <pthread.h>
+
+typedef struct
+{
+  vcl_test_session_t *sessions;
+  uint32_t n_sessions;
+  uint32_t wrk_index;
+  fd_set wr_fdset;
+  fd_set rd_fdset;
+  int max_fd_index;
+  pthread_t thread_handle;
+  vcl_test_cfg_t cfg;
+} vcl_test_client_worker_t;
+
+typedef struct
+{
+  vcl_test_client_worker_t *workers;
+  vppcom_endpt_t server_endpt;
+  uint32_t cfg_seq_num;
+  vcl_test_session_t ctrl_session;
+  vcl_test_session_t *sessions;
+  uint8_t dump_cfg;
+  vcl_test_t post_test;
+  uint32_t proto;
+  uint32_t n_workers;
+  volatile int active_workers;
+  struct sockaddr_storage server_addr;
+} vcl_test_client_main_t;
+
+static __thread int __wrk_index = 0;
+
+vcl_test_client_main_t vcl_client_main;
+
+#define vtc_min(a, b) (a < b ? a : b)
+#define vtc_max(a, b) (a > b ? a : b)
+
+static int
+vtc_cfg_sync (vcl_test_session_t * ts)
+{
+  vcl_test_cfg_t *rx_cfg = (vcl_test_cfg_t *) ts->rxbuf;
+  int rx_bytes, tx_bytes;
+
+  vt_atomic_add (&ts->cfg.seq_num, 1);
+  if (ts->cfg.verbose)
+    {
+      vtinf ("(fd %d): Sending config to server.", ts->fd);
+      vcl_test_cfg_dump (&ts->cfg, 1 /* is_client */ );
+    }
+  tx_bytes = vcl_test_write (ts->fd, (uint8_t *) & ts->cfg,
+			     sizeof (ts->cfg), NULL, ts->cfg.verbose);
+  if (tx_bytes < 0)
+    {
+      vtwrn ("(fd %d): write test cfg failed (%d)!", ts->fd, tx_bytes);
+      return tx_bytes;
+    }
+
+  rx_bytes = vcl_test_read (ts->fd, (uint8_t *) ts->rxbuf,
+			    sizeof (vcl_test_cfg_t), NULL);
+  if (rx_bytes < 0)
+    return rx_bytes;
+
+  if (rx_cfg->magic != VCL_TEST_CFG_CTRL_MAGIC)
+    {
+      vtwrn ("(fd %d): Bad server reply cfg -- aborting!", ts->fd);
+      return -1;
+    }
+  if ((rx_bytes != sizeof (vcl_test_cfg_t))
+      || !vcl_test_cfg_verify (rx_cfg, &ts->cfg))
+    {
+      vtwrn ("(fd %d): Invalid config received from server!", ts->fd);
+      if (rx_bytes != sizeof (vcl_test_cfg_t))
+	{
+	  vtinf ("\tRx bytes %d != cfg size %lu", rx_bytes,
+		 sizeof (vcl_test_cfg_t));
+	}
+      else
+	{
+	  vcl_test_cfg_dump (rx_cfg, 1 /* is_client */ );
+	  vtinf ("(fd %d): Valid config sent to server.", ts->fd);
+	  vcl_test_cfg_dump (&ts->cfg, 1 /* is_client */ );
+	}
+      return -1;
+    }
+  if (ts->cfg.verbose)
+    {
+      vtinf ("(fd %d): Got config back from server.", ts->fd);
+      vcl_test_cfg_dump (rx_cfg, 1 /* is_client */ );
+    }
+
+  return 0;
+}
+
+static int
+vtc_connect_test_sessions (vcl_test_client_worker_t * wrk)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ts;
+  uint32_t n_test_sessions;
+  int i, rv;
+
+  n_test_sessions = wrk->cfg.num_test_sessions;
+  if (n_test_sessions < 1)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  if (wrk->n_sessions >= n_test_sessions)
+    goto done;
+
+  if (wrk->n_sessions)
+    wrk->sessions = realloc (wrk->sessions,
+			     n_test_sessions * sizeof (vcl_test_session_t));
+  else
+    wrk->sessions = calloc (n_test_sessions, sizeof (vcl_test_session_t));
+
+  if (!wrk->sessions)
+    {
+      vterr ("failed to alloc sessions", -errno);
+      return errno;
+    }
+
+  for (i = 0; i < n_test_sessions; i++)
+    {
+      ts = &wrk->sessions[i];
+      ts->fd = vppcom_session_create (vcm->proto, 1 /* is_nonblocking */ );
+      if (ts->fd < 0)
+	{
+	  vterr ("vppcom_session_create()", ts->fd);
+	  return ts->fd;
+	}
+
+      rv = vppcom_session_connect (ts->fd, &vcm->server_endpt);
+      if (rv < 0)
+	{
+	  vterr ("vppcom_session_connect()", rv);
+	  return rv;
+	}
+      vtinf ("Test session %d (fd %d) connected.", i, ts->fd);
+    }
+  wrk->n_sessions = n_test_sessions;
+
+done:
+  vtinf ("All test sessions (%d) connected!", n_test_sessions);
+  return 0;
+}
+
+static int
+vtc_worker_test_setup (vcl_test_client_worker_t * wrk)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  vcl_test_cfg_t *cfg = &wrk->cfg;
+  vcl_test_session_t *ts;
+  uint32_t sidx;
+  int i, j;
+
+  FD_ZERO (&wrk->wr_fdset);
+  FD_ZERO (&wrk->rd_fdset);
+
+  for (i = 0; i < cfg->num_test_sessions; i++)
+    {
+      ts = &wrk->sessions[i];
+      ts->cfg = wrk->cfg;
+      vcl_test_session_buf_alloc (ts);
+
+      switch (cfg->test)
+	{
+	case VCL_TEST_TYPE_ECHO:
+	  memcpy (ts->txbuf, ctrl->txbuf, cfg->total_bytes);
+	  break;
+	case VCL_TEST_TYPE_UNI:
+	case VCL_TEST_TYPE_BI:
+	  for (j = 0; j < ts->txbuf_size; j++)
+	    ts->txbuf[j] = j & 0xff;
+	  break;
+	}
+
+      FD_SET (vppcom_session_index (ts->fd), &wrk->wr_fdset);
+      FD_SET (vppcom_session_index (ts->fd), &wrk->rd_fdset);
+      sidx = vppcom_session_index (ts->fd);
+      wrk->max_fd_index = vtc_max (sidx, wrk->max_fd_index);
+    }
+  wrk->max_fd_index += 1;
+
+  return 0;
+}
+
+static int
+vtc_worker_init (vcl_test_client_worker_t * wrk)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_cfg_t *cfg = &wrk->cfg;
+  vcl_test_session_t *ts;
+  uint32_t n;
+  int rv;
+
+  __wrk_index = wrk->wrk_index;
+
+  vtinf ("Initializing worker %u ...", wrk->wrk_index);
+
+  if (wrk->wrk_index)
+    {
+      if (vppcom_worker_register ())
+	{
+	  vtwrn ("failed to register worker");
+	  return -1;
+	}
+      vt_atomic_add (&vcm->active_workers, 1);
+    }
+  rv = vtc_connect_test_sessions (wrk);
+  if (rv)
+    {
+      vterr ("vtc_connect_test_sessions ()", rv);
+      return rv;
+    }
+
+  if (vtc_worker_test_setup (wrk))
+    return -1;
+
+  vtinf ("Sending config to server on all sessions ...");
+
+  for (n = 0; n < cfg->num_test_sessions; n++)
+    {
+      ts = &wrk->sessions[n];
+      if (vtc_cfg_sync (ts))
+	return -1;
+      memset (&ts->stats, 0, sizeof (ts->stats));
+    }
+
+  return 0;
+}
+
+static int stats_lock = 0;
+
+static void
+vtc_accumulate_stats (vcl_test_client_worker_t * wrk,
+		      vcl_test_session_t * ctrl)
+{
+  vcl_test_session_t *ts;
+  static char buf[64];
+  int i, show_rx = 0;
+
+  while (__sync_lock_test_and_set (&stats_lock, 1))
+    ;
+
+  if (ctrl->cfg.test == VCL_TEST_TYPE_BI
+      || ctrl->cfg.test == VCL_TEST_TYPE_ECHO)
+    show_rx = 1;
+
+  for (i = 0; i < wrk->cfg.num_test_sessions; i++)
+    {
+      ts = &wrk->sessions[i];
+      ts->stats.start = ctrl->stats.start;
+
+      if (ctrl->cfg.verbose > 1)
+	{
+	  sprintf (buf, "CLIENT (fd %d) RESULTS", ts->fd);
+	  vcl_test_stats_dump (buf, &ts->stats, show_rx, 1 /* show tx */ ,
+			       ctrl->cfg.verbose);
+	}
+
+      vcl_test_stats_accumulate (&ctrl->stats, &ts->stats);
+      if (vcl_comp_tspec (&ctrl->stats.stop, &ts->stats.stop) < 0)
+	ctrl->stats.stop = ts->stats.stop;
+    }
+
+  __sync_lock_release (&stats_lock);
+}
+
+static void
+vtc_worker_sessions_exit (vcl_test_client_worker_t * wrk)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  vcl_test_session_t *ts;
+  int i, verbose = ctrl->cfg.verbose;
+
+  for (i = 0; i < wrk->cfg.num_test_sessions; i++)
+    {
+      ts = &wrk->sessions[i];
+      ts->cfg.test = VCL_TEST_TYPE_EXIT;
+
+      if (verbose)
+	{
+	  vtinf ("(fd %d): Sending exit cfg to server...", ts->fd);
+	  vcl_test_cfg_dump (&ts->cfg, 1 /* is_client */ );
+	}
+      (void) vcl_test_write (ts->fd, (uint8_t *) & ts->cfg,
+			     sizeof (ts->cfg), &ts->stats, verbose);
+    }
+  wrk->n_sessions = 0;
+}
+
+static void *
+vtc_worker_loop (void *arg)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  vcl_test_client_worker_t *wrk = arg;
+  uint32_t n_active_sessions, n_bytes;
+  fd_set _wfdset, *wfdset = &_wfdset;
+  fd_set _rfdset, *rfdset = &_rfdset;
+  vcl_test_session_t *ts;
+  int i, rv, check_rx = 0;
+
+  rv = vtc_worker_init (wrk);
+  if (rv)
+    {
+      vterr ("vtc_worker_init()", rv);
+      return 0;
+    }
+
+  vtinf ("Starting test ...");
+
+  if (wrk->wrk_index == 0)
+    clock_gettime (CLOCK_REALTIME, &ctrl->stats.start);
+
+  check_rx = wrk->cfg.test != VCL_TEST_TYPE_UNI;
+  n_active_sessions = wrk->cfg.num_test_sessions;
+  while (n_active_sessions)
+    {
+      _wfdset = wrk->wr_fdset;
+      _rfdset = wrk->rd_fdset;
+
+      rv = vppcom_select (wrk->max_fd_index, (unsigned long *) rfdset,
+			  (unsigned long *) wfdset, NULL, 0);
+      if (rv < 0)
+	{
+	  vterr ("vppcom_select()", rv);
+	  goto exit;
+	}
+      else if (rv == 0)
+	continue;
+
+      for (i = 0; i < wrk->cfg.num_test_sessions; i++)
+	{
+	  ts = &wrk->sessions[i];
+	  if (!((ts->stats.stop.tv_sec == 0) &&
+		(ts->stats.stop.tv_nsec == 0)))
+	    continue;
+
+	  if (FD_ISSET (vppcom_session_index (ts->fd), rfdset)
+	      && ts->stats.rx_bytes < ts->cfg.total_bytes)
+	    {
+	      (void) vcl_test_read (ts->fd, (uint8_t *) ts->rxbuf,
+				    ts->rxbuf_size, &ts->stats);
+	    }
+
+	  if (FD_ISSET (vppcom_session_index (ts->fd), wfdset)
+	      && ts->stats.tx_bytes < ts->cfg.total_bytes)
+	    {
+	      n_bytes = ts->cfg.txbuf_size;
+	      if (ts->cfg.test == VCL_TEST_TYPE_ECHO)
+		n_bytes = strlen (ctrl->txbuf) + 1;
+	      rv = vcl_test_write (ts->fd, (uint8_t *) ts->txbuf,
+				   n_bytes, &ts->stats, ts->cfg.verbose);
+	      if (rv < 0)
+		{
+		  vtwrn ("vppcom_test_write (%d) failed -- aborting test",
+			 ts->fd);
+		  goto exit;
+		}
+	    }
+
+	  if ((!check_rx && ts->stats.tx_bytes >= ts->cfg.total_bytes)
+	      || (check_rx && ts->stats.rx_bytes >= ts->cfg.total_bytes))
+	    {
+	      clock_gettime (CLOCK_REALTIME, &ts->stats.stop);
+	      n_active_sessions--;
+	    }
+	}
+    }
+exit:
+  vtinf ("Worker %d done ...", wrk->wrk_index);
+  if (wrk->cfg.test != VCL_TEST_TYPE_ECHO)
+    vtc_accumulate_stats (wrk, ctrl);
+  sleep (VCL_TEST_DELAY_DISCONNECT);
+  vtc_worker_sessions_exit (wrk);
+  if (wrk->wrk_index)
+    vt_atomic_add (&vcm->active_workers, -1);
+  return 0;
+}
+
+static void
+vtc_print_stats (vcl_test_session_t * ctrl)
+{
+  int is_echo = ctrl->cfg.test == VCL_TEST_TYPE_ECHO;
+  int show_rx = 0;
+  char buf[64];
+
+  if (ctrl->cfg.test == VCL_TEST_TYPE_BI
+      || ctrl->cfg.test == VCL_TEST_TYPE_ECHO)
+    show_rx = 1;
+
+  vcl_test_stats_dump ("CLIENT RESULTS", &ctrl->stats,
+		       show_rx, 1 /* show tx */ ,
+		       ctrl->cfg.verbose);
+  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+
+  if (ctrl->cfg.verbose)
+    {
+      vtinf ("  ctrl session info\n"
+	     VCL_TEST_SEPARATOR_STRING
+	     "          fd:  %d (0x%08x)\n"
+	     "       rxbuf:  %p\n"
+	     "  rxbuf size:  %u (0x%08x)\n"
+	     "       txbuf:  %p\n"
+	     "  txbuf size:  %u (0x%08x)\n"
+	     VCL_TEST_SEPARATOR_STRING,
+	     ctrl->fd, (uint32_t) ctrl->fd,
+	     ctrl->rxbuf, ctrl->rxbuf_size, ctrl->rxbuf_size,
+	     ctrl->txbuf, ctrl->txbuf_size, ctrl->txbuf_size);
+    }
+
+  if (is_echo)
+    sprintf (buf, "Echo");
+  else
+    sprintf (buf, "%s-directional Stream",
+	     ctrl->cfg.test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");
+}
+
+static void
+vtc_echo_client (vcl_test_client_main_t * vcm)
+{
+  vcl_test_client_worker_t *wrk;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  vcl_test_cfg_t *cfg = &ctrl->cfg;
+
+  cfg->total_bytes = strlen (ctrl->txbuf) + 1;
+  memset (&ctrl->stats, 0, sizeof (ctrl->stats));
+
+  /* Echo works with only one worker */
+  wrk = vcm->workers;
+  wrk->wrk_index = 0;
+  wrk->cfg = *cfg;
+
+  vtc_worker_loop (wrk);
+
+  /* Not relevant for echo test
+     clock_gettime (CLOCK_REALTIME, &ctrl->stats.stop);
+     vtc_accumulate_stats (wrk, ctrl);
+     vtc_print_stats (ctrl);
+   */
+}
+
+static void
+vtc_stream_client (vcl_test_client_main_t * vcm)
+{
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  vcl_test_cfg_t *cfg = &ctrl->cfg;
+  vcl_test_client_worker_t *wrk;
+  uint32_t i, n_conn, n_conn_per_wrk;
+
+  vtinf ("%s-directional Stream Test Starting!",
+	 ctrl->cfg.test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");
+
+  cfg->total_bytes = cfg->num_writes * cfg->txbuf_size;
+  cfg->ctrl_handle = ~0;
+  if (vtc_cfg_sync (ctrl))
+    {
+      vtwrn ("test cfg sync failed -- aborting!");
+      return;
+    }
+  cfg->ctrl_handle = ((vcl_test_cfg_t *) ctrl->rxbuf)->ctrl_handle;
+  memset (&ctrl->stats, 0, sizeof (ctrl->stats));
+
+  n_conn = cfg->num_test_sessions;
+  n_conn_per_wrk = n_conn / vcm->n_workers;
+  for (i = 0; i < vcm->n_workers; i++)
+    {
+      wrk = &vcm->workers[i];
+      wrk->wrk_index = i;
+      wrk->cfg = ctrl->cfg;
+      wrk->cfg.num_test_sessions = vtc_min (n_conn_per_wrk, n_conn);
+      n_conn -= wrk->cfg.num_test_sessions;
+    }
+
+  for (i = 1; i < vcm->n_workers; i++)
+    {
+      wrk = &vcm->workers[i];
+      pthread_create (&wrk->thread_handle, NULL, vtc_worker_loop,
+		      (void *) wrk);
+    }
+  vtc_worker_loop (&vcm->workers[0]);
+
+  while (vcm->active_workers > 0)
+    ;
+
+  vtinf ("Sending config on ctrl session (fd %d) for stats...", ctrl->fd);
+  if (vtc_cfg_sync (ctrl))
+    {
+      vtwrn ("test cfg sync failed -- aborting!");
+      return;
+    }
+
+  vtc_print_stats (ctrl);
+
+  ctrl->cfg.test = VCL_TEST_TYPE_ECHO;
+  ctrl->cfg.total_bytes = 0;
+  if (vtc_cfg_sync (ctrl))
+    vtwrn ("post-test cfg sync failed!");
+}
+
+static void
+dump_help (void)
+{
+#define INDENT "\n  "
+
+  printf ("CLIENT: Test configuration commands:"
+	  INDENT VCL_TEST_TOKEN_HELP
+	  "\t\t\tDisplay help."
+	  INDENT VCL_TEST_TOKEN_EXIT
+	  "\t\t\tExit test client & server."
+	  INDENT VCL_TEST_TOKEN_SHOW_CFG
+	  "\t\t\tShow the current test cfg."
+	  INDENT VCL_TEST_TOKEN_RUN_UNI
+	  "\t\t\tRun the Uni-directional test."
+	  INDENT VCL_TEST_TOKEN_RUN_BI
+	  "\t\t\tRun the Bi-directional test."
+	  INDENT VCL_TEST_TOKEN_VERBOSE
+	  "\t\t\tToggle verbose setting."
+	  INDENT VCL_TEST_TOKEN_RXBUF_SIZE
+	  "<rxbuf size>\tRx buffer size (bytes)."
+	  INDENT VCL_TEST_TOKEN_TXBUF_SIZE
+	  "<txbuf size>\tTx buffer size (bytes)."
+	  INDENT VCL_TEST_TOKEN_NUM_WRITES
+	  "<# of writes>\tNumber of txbuf writes to server." "\n");
+}
+
+static void
+cfg_txbuf_size_set (void)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_TXBUF_SIZE);
+  uint64_t txbuf_size = strtoull ((const char *) p, NULL, 10);
+
+  if (txbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+    {
+      ctrl->cfg.txbuf_size = txbuf_size;
+      ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+      vcl_test_buf_alloc (&ctrl->cfg, 0 /* is_rxbuf */ ,
+			  (uint8_t **) & ctrl->txbuf, &ctrl->txbuf_size);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    vtwrn ("Invalid txbuf size (%lu) < minimum buf size (%u)!",
+	   txbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+}
+
+static void
+cfg_num_writes_set (void)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_NUM_WRITES);
+  uint32_t num_writes = strtoul ((const char *) p, NULL, 10);
+
+  if (num_writes > 0)
+    {
+      ctrl->cfg.num_writes = num_writes;
+      ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    {
+      vtwrn ("invalid num writes: %u", num_writes);
+    }
+}
+
+static void
+cfg_num_test_sessions_set (void)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_NUM_TEST_SESS);
+  uint32_t num_test_sessions = strtoul ((const char *) p, NULL, 10);
+
+  if ((num_test_sessions > 0) &&
+      (num_test_sessions <= VCL_TEST_CFG_MAX_TEST_SESS))
+    {
+      ctrl->cfg.num_test_sessions = num_test_sessions;
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    {
+      vtwrn ("invalid num test sessions: %u, (%d max)",
+	     num_test_sessions, VCL_TEST_CFG_MAX_TEST_SESS);
+    }
+}
+
+static void
+cfg_rxbuf_size_set (void)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  char *p = ctrl->txbuf + strlen (VCL_TEST_TOKEN_RXBUF_SIZE);
+  uint64_t rxbuf_size = strtoull ((const char *) p, NULL, 10);
+
+  if (rxbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+    {
+      ctrl->cfg.rxbuf_size = rxbuf_size;
+      vcl_test_buf_alloc (&ctrl->cfg, 1 /* is_rxbuf */ ,
+			  (uint8_t **) & ctrl->rxbuf, &ctrl->rxbuf_size);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  else
+    vtwrn ("Invalid rxbuf size (%lu) < minimum buf size (%u)!",
+	   rxbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+}
+
+static void
+cfg_verbose_toggle (void)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+
+  ctrl->cfg.verbose = ctrl->cfg.verbose ? 0 : 1;
+  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+
+}
+
+static vcl_test_t
+parse_input ()
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  vcl_test_t rv = VCL_TEST_TYPE_NONE;
+
+  if (!strncmp (VCL_TEST_TOKEN_EXIT, ctrl->txbuf,
+		strlen (VCL_TEST_TOKEN_EXIT)))
+    rv = VCL_TEST_TYPE_EXIT;
+
+  else if (!strncmp (VCL_TEST_TOKEN_HELP, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_HELP)))
+    dump_help ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_SHOW_CFG, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_SHOW_CFG)))
+    vcm->dump_cfg = 1;
+
+  else if (!strncmp (VCL_TEST_TOKEN_VERBOSE, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_VERBOSE)))
+    cfg_verbose_toggle ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_TXBUF_SIZE, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_TXBUF_SIZE)))
+    cfg_txbuf_size_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_NUM_TEST_SESS, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_NUM_TEST_SESS)))
+    cfg_num_test_sessions_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_NUM_WRITES, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_NUM_WRITES)))
+    cfg_num_writes_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_RXBUF_SIZE, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_RXBUF_SIZE)))
+    cfg_rxbuf_size_set ();
+
+  else if (!strncmp (VCL_TEST_TOKEN_RUN_UNI, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_RUN_UNI)))
+    rv = ctrl->cfg.test = VCL_TEST_TYPE_UNI;
+
+  else if (!strncmp (VCL_TEST_TOKEN_RUN_BI, ctrl->txbuf,
+		     strlen (VCL_TEST_TOKEN_RUN_BI)))
+    rv = ctrl->cfg.test = VCL_TEST_TYPE_BI;
+
+  else
+    rv = VCL_TEST_TYPE_ECHO;
+
+  return rv;
+}
+
+void
+print_usage_and_exit (void)
+{
+  fprintf (stderr,
+	   "vcl_test_client [OPTIONS] <ipaddr> <port>\n"
+	   "  OPTIONS\n"
+	   "  -h               Print this message and exit.\n"
+	   "  -6               Use IPv6\n"
+	   "  -c               Print test config before test.\n"
+	   "  -w <dir>         Write test results to <dir>.\n"
+	   "  -X               Exit after running test.\n"
+	   "  -D               Use UDP transport layer\n"
+	   "  -L               Use TLS transport layer\n"
+	   "  -E               Run Echo test.\n"
+	   "  -N <num-writes>  Test Cfg: number of writes.\n"
+	   "  -R <rxbuf-size>  Test Cfg: rx buffer size.\n"
+	   "  -T <txbuf-size>  Test Cfg: tx buffer size.\n"
+	   "  -U               Run Uni-directional test.\n"
+	   "  -B               Run Bi-directional test.\n"
+	   "  -V               Verbose mode.\n");
+  exit (1);
+}
+
+static void
+vtc_process_opts (vcl_test_client_main_t * vcm, int argc, char **argv)
+{
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  int c, v;
+
+  opterr = 0;
+  while ((c = getopt (argc, argv, "chn:w:XE:I:N:R:T:UBV6DL")) != -1)
+    switch (c)
+      {
+      case 'c':
+	vcm->dump_cfg = 1;
+	break;
+
+      case 's':
+	if (sscanf (optarg, "0x%x", &ctrl->cfg.num_test_sessions) != 1)
+	  if (sscanf (optarg, "%u", &ctrl->cfg.num_test_sessions) != 1)
+	    {
+	      vtwrn ("Invalid value for option -%c!", c);
+	      print_usage_and_exit ();
+	    }
+	if (!ctrl->cfg.num_test_sessions ||
+	    (ctrl->cfg.num_test_sessions > FD_SETSIZE))
+	  {
+	    vtwrn ("Invalid number of sessions (%d) specified for option -%c!"
+		   "\n       Valid range is 1 - %d",
+		   ctrl->cfg.num_test_sessions, c, FD_SETSIZE);
+	    print_usage_and_exit ();
+	  }
+	break;
+
+      case 'w':
+	if (sscanf (optarg, "%d", &v) != 1)
+	  {
+	    vtwrn ("Invalid value for option -%c!", c);
+	    print_usage_and_exit ();
+	  }
+	if (v > 1)
+	  vcm->n_workers = v;
+	break;
+
+      case 'X':
+	vcm->post_test = VCL_TEST_TYPE_EXIT;
+	break;
+
+      case 'E':
+	if (strlen (optarg) > ctrl->txbuf_size)
+	  {
+	    vtwrn ("Option -%c value larger than txbuf size (%d)!",
+		   optopt, ctrl->txbuf_size);
+	    print_usage_and_exit ();
+	  }
+	strcpy (ctrl->txbuf, optarg);
+	ctrl->cfg.test = VCL_TEST_TYPE_ECHO;
+	break;
+
+      case 'I':
+	if (sscanf (optarg, "0x%x", &ctrl->cfg.num_test_sessions) != 1)
+	  if (sscanf (optarg, "%d", &ctrl->cfg.num_test_sessions) != 1)
+	    {
+	      vtwrn ("Invalid value for option -%c!", c);
+	      print_usage_and_exit ();
+	    }
+	if (ctrl->cfg.num_test_sessions > VCL_TEST_CFG_MAX_TEST_SESS)
+	  {
+	    vtwrn ("value greater than max number test sessions (%d)!",
+		   VCL_TEST_CFG_MAX_TEST_SESS);
+	    print_usage_and_exit ();
+	  }
+	break;
+
+      case 'N':
+	if (sscanf (optarg, "0x%lx", &ctrl->cfg.num_writes) != 1)
+	  if (sscanf (optarg, "%ld", &ctrl->cfg.num_writes) != 1)
+	    {
+	      vtwrn ("Invalid value for option -%c!", c);
+	      print_usage_and_exit ();
+	    }
+	ctrl->cfg.total_bytes = ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+	break;
+
+      case 'R':
+	if (sscanf (optarg, "0x%lx", &ctrl->cfg.rxbuf_size) != 1)
+	  if (sscanf (optarg, "%ld", &ctrl->cfg.rxbuf_size) != 1)
+	    {
+	      vtwrn ("Invalid value for option -%c!", c);
+	      print_usage_and_exit ();
+	    }
+	if (ctrl->cfg.rxbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+	  {
+	    ctrl->rxbuf_size = ctrl->cfg.rxbuf_size;
+	    vcl_test_buf_alloc (&ctrl->cfg, 1 /* is_rxbuf */ ,
+				(uint8_t **) & ctrl->rxbuf,
+				&ctrl->rxbuf_size);
+	  }
+	else
+	  {
+	    vtwrn ("rxbuf size (%lu) less than minumum (%u)",
+		   ctrl->cfg.rxbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+	    print_usage_and_exit ();
+	  }
+
+	break;
+
+      case 'T':
+	if (sscanf (optarg, "0x%lx", &ctrl->cfg.txbuf_size) != 1)
+	  if (sscanf (optarg, "%ld", &ctrl->cfg.txbuf_size) != 1)
+	    {
+	      vtwrn ("Invalid value for option -%c!", c);
+	      print_usage_and_exit ();
+	    }
+	if (ctrl->cfg.txbuf_size >= VCL_TEST_CFG_BUF_SIZE_MIN)
+	  {
+	    ctrl->txbuf_size = ctrl->cfg.txbuf_size;
+	    vcl_test_buf_alloc (&ctrl->cfg, 0 /* is_rxbuf */ ,
+				(uint8_t **) & ctrl->txbuf,
+				&ctrl->txbuf_size);
+	    ctrl->cfg.total_bytes =
+	      ctrl->cfg.num_writes * ctrl->cfg.txbuf_size;
+	  }
+	else
+	  {
+	    vtwrn ("txbuf size (%lu) less than minumum (%u)!",
+		   ctrl->cfg.txbuf_size, VCL_TEST_CFG_BUF_SIZE_MIN);
+	    print_usage_and_exit ();
+	  }
+	break;
+
+      case 'U':
+	ctrl->cfg.test = VCL_TEST_TYPE_UNI;
+	break;
+
+      case 'B':
+	ctrl->cfg.test = VCL_TEST_TYPE_BI;
+	break;
+
+      case 'V':
+	ctrl->cfg.verbose = 1;
+	break;
+
+      case '6':
+	ctrl->cfg.address_ip6 = 1;
+	break;
+
+      case 'D':
+	ctrl->cfg.transport_udp = 1;
+	break;
+
+      case 'L':
+	ctrl->cfg.transport_tls = 1;
+	break;
+
+      case '?':
+	switch (optopt)
+	  {
+	  case 'E':
+	  case 'I':
+	  case 'N':
+	  case 'R':
+	  case 'T':
+	  case 'w':
+	    vtwrn ("Option -%c requires an argument.", optopt);
+	    break;
+
+	  default:
+	    if (isprint (optopt))
+	      vtwrn ("Unknown option `-%c'.", optopt);
+	    else
+	      vtwrn ("Unknown option character `\\x%x'.", optopt);
+	  }
+	/* fall thru */
+      case 'h':
+      default:
+	print_usage_and_exit ();
+      }
+
+  if (argc < (optind + 2))
+    {
+      vtwrn ("Insufficient number of arguments!");
+      print_usage_and_exit ();
+    }
+
+  if (ctrl->cfg.transport_udp)
+    {
+      vcm->proto = VPPCOM_PROTO_UDP;
+    }
+  else if (ctrl->cfg.transport_tls)
+    {
+      vcm->proto = VPPCOM_PROTO_TLS;
+    }
+  else
+    {
+      vcm->proto = VPPCOM_PROTO_TCP;
+    }
+
+  memset (&vcm->server_addr, 0, sizeof (vcm->server_addr));
+  if (ctrl->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *sddr6 = (struct sockaddr_in6 *) &vcm->server_addr;
+      sddr6->sin6_family = AF_INET6;
+      inet_pton (AF_INET6, argv[optind++], &(sddr6->sin6_addr));
+      sddr6->sin6_port = htons (atoi (argv[optind]));
+
+      vcm->server_endpt.is_ip4 = 0;
+      vcm->server_endpt.ip = (uint8_t *) & sddr6->sin6_addr;
+      vcm->server_endpt.port = (uint16_t) sddr6->sin6_port;
+    }
+  else
+    {
+      struct sockaddr_in *saddr4 = (struct sockaddr_in *) &vcm->server_addr;
+      saddr4->sin_family = AF_INET;
+      inet_pton (AF_INET, argv[optind++], &(saddr4->sin_addr));
+      saddr4->sin_port = htons (atoi (argv[optind]));
+
+      vcm->server_endpt.is_ip4 = 1;
+      vcm->server_endpt.ip = (uint8_t *) & saddr4->sin_addr;
+      vcm->server_endpt.port = (uint16_t) saddr4->sin_port;
+    }
+}
+
+static void
+vtc_read_user_input (vcl_test_session_t * ctrl)
+{
+  printf ("\nType some characters and hit <return>\n"
+	  "('" VCL_TEST_TOKEN_HELP "' for help): ");
+
+  if (fgets (ctrl->txbuf, ctrl->txbuf_size, stdin) != NULL)
+    {
+      if (strlen (ctrl->txbuf) == 1)
+	{
+	  printf ("\nNothing to send!  Please try again...\n");
+	  return;
+	}
+      ctrl->txbuf[strlen (ctrl->txbuf) - 1] = 0;	// chomp the newline.
+
+      /* Parse input for keywords */
+      ctrl->cfg.test = parse_input ();
+    }
+}
+
+static void
+vtc_ctrl_session_exit (void)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  int verbose = ctrl->cfg.verbose;
+
+  ctrl->cfg.test = VCL_TEST_TYPE_EXIT;
+  if (verbose)
+    {
+      vtinf ("(fd %d): Sending exit cfg to server...", ctrl->fd);
+      vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
+  (void) vcl_test_write (ctrl->fd, (uint8_t *) & ctrl->cfg,
+			 sizeof (ctrl->cfg), &ctrl->stats, verbose);
+  sleep (1);
+}
+
+int
+main (int argc, char **argv)
+{
+  vcl_test_client_main_t *vcm = &vcl_client_main;
+  vcl_test_session_t *ctrl = &vcm->ctrl_session;
+  int rv;
+
+  vcm->n_workers = 1;
+  vcl_test_cfg_init (&ctrl->cfg);
+  vcl_test_session_buf_alloc (ctrl);
+  vtc_process_opts (vcm, argc, argv);
+
+  vcm->workers = calloc (vcm->n_workers, sizeof (vcl_test_client_worker_t));
+  rv = vppcom_app_create ("vcl_test_client");
+  if (rv < 0)
+    vtfail ("vppcom_app_create()", rv);
+
+  ctrl->fd = vppcom_session_create (vcm->proto, 0 /* is_nonblocking */ );
+  if (ctrl->fd < 0)
+    vtfail ("vppcom_session_create()", ctrl->fd);
+
+  if (vcm->proto == VPPCOM_PROTO_TLS)
+    {
+      vtinf ("Adding tls certs ...");
+      vppcom_session_tls_add_cert (ctrl->fd, vcl_test_crt_rsa,
+				   vcl_test_crt_rsa_len);
+      vppcom_session_tls_add_key (ctrl->fd, vcl_test_key_rsa,
+				  vcl_test_key_rsa_len);
+    }
+
+  vtinf ("Connecting to server...");
+  rv = vppcom_session_connect (ctrl->fd, &vcm->server_endpt);
+  if (rv)
+    vtfail ("vppcom_session_connect()", rv);
+  vtinf ("Control session (fd %d) connected.", ctrl->fd);
+
+  rv = vtc_cfg_sync (ctrl);
+  if (rv)
+    vtfail ("vtc_cfg_sync()", rv);
+
+  ctrl->cfg.ctrl_handle = ((vcl_test_cfg_t *) ctrl->rxbuf)->ctrl_handle;
+  memset (&ctrl->stats, 0, sizeof (ctrl->stats));
+
+  while (ctrl->cfg.test != VCL_TEST_TYPE_EXIT)
+    {
+      if (vcm->dump_cfg)
+	{
+	  vcl_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+	  vcm->dump_cfg = 0;
+	}
+
+      switch (ctrl->cfg.test)
+	{
+	case VCL_TEST_TYPE_ECHO:
+	  vtc_echo_client (vcm);
+	  break;
+
+	case VCL_TEST_TYPE_UNI:
+	case VCL_TEST_TYPE_BI:
+	  vtc_stream_client (vcm);
+	  break;
+
+	case VCL_TEST_TYPE_EXIT:
+	  continue;
+
+	case VCL_TEST_TYPE_NONE:
+	default:
+	  break;
+	}
+      switch (vcm->post_test)
+	{
+	case VCL_TEST_TYPE_EXIT:
+	  switch (ctrl->cfg.test)
+	    {
+	    case VCL_TEST_TYPE_EXIT:
+	    case VCL_TEST_TYPE_UNI:
+	    case VCL_TEST_TYPE_BI:
+	    case VCL_TEST_TYPE_ECHO:
+	      ctrl->cfg.test = VCL_TEST_TYPE_EXIT;
+	      continue;
+
+	    case VCL_TEST_TYPE_NONE:
+	    default:
+	      break;
+	    }
+	  break;
+
+	case VCL_TEST_TYPE_NONE:
+	case VCL_TEST_TYPE_ECHO:
+	case VCL_TEST_TYPE_UNI:
+	case VCL_TEST_TYPE_BI:
+	default:
+	  break;
+	}
+
+      memset (ctrl->txbuf, 0, ctrl->txbuf_size);
+      memset (ctrl->rxbuf, 0, ctrl->rxbuf_size);
+
+      vtc_read_user_input (ctrl);
+    }
+
+  vtc_ctrl_session_exit ();
+  vppcom_session_close (ctrl->fd);
+  vppcom_app_destroy ();
+  free (vcm->workers);
+  return 0;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/hs_apps/vcl/vcl_test_server.c b/src/plugins/hs_apps/vcl/vcl_test_server.c
new file mode 100644
index 00000000000..62292adae5f
--- /dev/null
+++ b/src/plugins/hs_apps/vcl/vcl_test_server.c
@@ -0,0 +1,743 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <ctype.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <hs_apps/vcl/vcl_test.h>
+#include <sys/epoll.h>
+#include <vppinfra/mem.h>
+#include <pthread.h>
+
+typedef struct
+{
+  uint8_t is_alloc;
+  int fd;
+  uint8_t *buf;
+  uint32_t buf_size;
+  vcl_test_cfg_t cfg;
+  vcl_test_stats_t stats;
+  vppcom_endpt_t endpt;
+  uint8_t ip[16];
+  vppcom_data_segments_t ds;
+} vcl_test_server_conn_t;
+
+typedef struct
+{
+  uint16_t port;
+  uint32_t address_ip6;
+  u8 proto;
+  u8 workers;
+  vppcom_endpt_t endpt;
+} vcl_test_server_cfg_t;
+
+typedef struct
+{
+  uint32_t wrk_index;
+  int listen_fd;
+  int epfd;
+  struct epoll_event wait_events[VCL_TEST_CFG_MAX_EPOLL_EVENTS];
+  size_t conn_pool_size;
+  vcl_test_server_conn_t *conn_pool;
+  int nfds;
+  pthread_t thread_handle;
+} vcl_test_server_worker_t;
+
+typedef struct
+{
+  vcl_test_server_cfg_t cfg;
+  vcl_test_server_worker_t *workers;
+
+  struct sockaddr_storage servaddr;
+  volatile int worker_fails;
+  volatile int active_workers;
+  u8 use_ds;
+} vcl_test_server_main_t;
+
+static __thread int __wrk_index = 0;
+
+static vcl_test_server_main_t vcl_server_main;
+
+static inline void
+conn_pool_expand (vcl_test_server_worker_t * wrk, size_t expand_size)
+{
+  vcl_test_server_conn_t *conn_pool;
+  size_t new_size = wrk->conn_pool_size + expand_size;
+  int i;
+
+  conn_pool = realloc (wrk->conn_pool, new_size * sizeof (*wrk->conn_pool));
+  if (conn_pool)
+    {
+      for (i = wrk->conn_pool_size; i < new_size; i++)
+	{
+	  vcl_test_server_conn_t *conn = &conn_pool[i];
+	  memset (conn, 0, sizeof (*conn));
+	  vcl_test_cfg_init (&conn->cfg);
+	  vcl_test_buf_alloc (&conn->cfg, 1 /* is_rxbuf */ ,
+			      &conn->buf, &conn->buf_size);
+	  conn->cfg.txbuf_size = conn->cfg.rxbuf_size;
+	}
+
+      wrk->conn_pool = conn_pool;
+      wrk->conn_pool_size = new_size;
+    }
+  else
+    {
+      vterr ("conn_pool_expand()", -errno);
+    }
+}
+
+static inline vcl_test_server_conn_t *
+conn_pool_alloc (vcl_test_server_worker_t * wrk)
+{
+  int i, expand = 0;
+
+again:
+  for (i = 0; i < wrk->conn_pool_size; i++)
+    {
+      if (!wrk->conn_pool[i].is_alloc)
+	{
+	  wrk->conn_pool[i].endpt.ip = wrk->conn_pool[i].ip;
+	  wrk->conn_pool[i].is_alloc = 1;
+	  return (&wrk->conn_pool[i]);
+	}
+    }
+
+  if (expand == 0)
+    {
+      conn_pool_expand (wrk, 2 * wrk->conn_pool_size);
+      expand = 1;
+      goto again;
+    }
+  vtwrn ("Failed to allocate connection even after expand");
+  return 0;
+}
+
+static inline void
+conn_pool_free (vcl_test_server_conn_t * conn)
+{
+  conn->fd = 0;
+  conn->is_alloc = 0;
+}
+
+static inline void
+sync_config_and_reply (vcl_test_server_conn_t * conn, vcl_test_cfg_t * rx_cfg)
+{
+  conn->cfg = *rx_cfg;
+  vcl_test_buf_alloc (&conn->cfg, 1 /* is_rxbuf */ ,
+		      &conn->buf, &conn->buf_size);
+  conn->cfg.txbuf_size = conn->cfg.rxbuf_size;
+
+  if (conn->cfg.verbose)
+    {
+      vtinf ("(fd %d): Replying to cfg message!\n", conn->fd);
+      vcl_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
+    }
+  (void) vcl_test_write (conn->fd, (uint8_t *) & conn->cfg,
+			 sizeof (conn->cfg), NULL, conn->cfg.verbose);
+}
+
+static void
+vts_server_start_stop (vcl_test_server_worker_t * wrk,
+		       vcl_test_server_conn_t * conn, vcl_test_cfg_t * rx_cfg)
+{
+  u8 is_bi = rx_cfg->test == VCL_TEST_TYPE_BI;
+  vcl_test_server_conn_t *tc;
+  char buf[64];
+  int i;
+
+  if (rx_cfg->ctrl_handle == conn->fd)
+    {
+      for (i = 0; i < wrk->conn_pool_size; i++)
+	{
+	  tc = &wrk->conn_pool[i];
+	  if (tc->cfg.ctrl_handle != conn->fd)
+	    continue;
+
+	  vcl_test_stats_accumulate (&conn->stats, &tc->stats);
+	  if (vcl_comp_tspec (&conn->stats.stop, &tc->stats.stop) < 0)
+	    conn->stats.stop = tc->stats.stop;
+	  /* Client delays sending of disconnect */
+	  conn->stats.stop.tv_sec -= VCL_TEST_DELAY_DISCONNECT;
+	  if (conn->cfg.verbose)
+	    {
+	      sprintf (buf, "SERVER (fd %d) RESULTS", tc->fd);
+	      vcl_test_stats_dump (buf, &tc->stats, 1 /* show_rx */ ,
+				   is_bi /* show tx */ , conn->cfg.verbose);
+	    }
+	}
+
+      vcl_test_stats_dump ("SERVER RESULTS", &conn->stats, 1 /* show_rx */ ,
+			   is_bi /* show_tx */ , conn->cfg.verbose);
+      vcl_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
+      if (conn->cfg.verbose)
+	{
+	  vtinf ("  vcl server main\n"
+		 VCL_TEST_SEPARATOR_STRING
+		 "       buf:  %p\n"
+		 "  buf size:  %u (0x%08x)\n"
+		 VCL_TEST_SEPARATOR_STRING,
+		 conn->buf, conn->buf_size, conn->buf_size);
+	}
+
+      sync_config_and_reply (conn, rx_cfg);
+      memset (&conn->stats, 0, sizeof (conn->stats));
+    }
+  else
+    {
+      if (rx_cfg->ctrl_handle == ~0)
+	{
+	  rx_cfg->ctrl_handle = conn->fd;
+	  vtinf ("Set control fd %d for test!", conn->fd);
+	}
+      else
+	{
+	  vtinf ("Starting %s-directional Stream Test (fd %d)!",
+		 is_bi ? "Bi" : "Uni", conn->fd);
+	}
+
+      sync_config_and_reply (conn, rx_cfg);
+
+      /* read the 1st chunk, record start time */
+      memset (&conn->stats, 0, sizeof (conn->stats));
+      clock_gettime (CLOCK_REALTIME, &conn->stats.start);
+    }
+}
+
+static inline void
+vts_server_rx (vcl_test_server_conn_t * conn, int rx_bytes)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+  int client_fd = conn->fd;
+
+  if (conn->cfg.test == VCL_TEST_TYPE_BI)
+    {
+      if (vsm->use_ds)
+	{
+	  (void) vcl_test_write (client_fd, conn->ds[0].data, conn->ds[0].len,
+				 &conn->stats, conn->cfg.verbose);
+	  if (conn->ds[1].len)
+	    (void) vcl_test_write (client_fd, conn->ds[1].data,
+				   conn->ds[1].len, &conn->stats,
+				   conn->cfg.verbose);
+	}
+      else
+	(void) vcl_test_write (client_fd, conn->buf, rx_bytes, &conn->stats,
+			       conn->cfg.verbose);
+    }
+
+  if (vsm->use_ds)
+    vppcom_session_free_segments (conn->fd, conn->ds);
+
+  if (conn->stats.rx_bytes >= conn->cfg.total_bytes)
+    clock_gettime (CLOCK_REALTIME, &conn->stats.stop);
+}
+
+static void
+vts_server_echo (vcl_test_server_conn_t * conn, int rx_bytes)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+  int tx_bytes, nbytes, pos;
+
+  if (vsm->use_ds)
+    vppcom_data_segment_copy (conn->buf, conn->ds, rx_bytes);
+
+  /* If it looks vaguely like a string, make sure it's terminated */
+  pos = rx_bytes < conn->buf_size ? rx_bytes : conn->buf_size - 1;
+  ((char *) conn->buf)[pos] = 0;
+  vtinf ("(fd %d): RX (%d bytes) - '%s'", conn->fd, rx_bytes, conn->buf);
+
+  if (conn->cfg.verbose)
+    vtinf ("(fd %d): Echoing back", conn->fd);
+
+  nbytes = strlen ((const char *) conn->buf) + 1;
+  tx_bytes = vcl_test_write (conn->fd, conn->buf, nbytes, &conn->stats,
+			     conn->cfg.verbose);
+  if (tx_bytes >= 0)
+    vtinf ("(fd %d): TX (%d bytes) - '%s'", conn->fd, tx_bytes, conn->buf);
+}
+
+static void
+vts_new_client (vcl_test_server_worker_t * wrk)
+{
+  vcl_test_server_conn_t *conn;
+  struct epoll_event ev;
+  int rv, client_fd;
+
+  conn = conn_pool_alloc (wrk);
+  if (!conn)
+    {
+      vtwrn ("No free connections!");
+      return;
+    }
+
+  client_fd = vppcom_session_accept (wrk->listen_fd, &conn->endpt, 0);
+  if (client_fd < 0)
+    {
+      vterr ("vppcom_session_accept()", client_fd);
+      return;
+    }
+  conn->fd = client_fd;
+
+  vtinf ("Got a connection -- fd = %d (0x%08x)!", client_fd, client_fd);
+
+  ev.events = EPOLLIN;
+  ev.data.u64 = conn - wrk->conn_pool;
+  rv = vppcom_epoll_ctl (wrk->epfd, EPOLL_CTL_ADD, client_fd, &ev);
+  if (rv < 0)
+    {
+      vterr ("vppcom_epoll_ctl()", rv);
+      return;
+    }
+  wrk->nfds++;
+}
+
+static void
+print_usage_and_exit (void)
+{
+  fprintf (stderr,
+	   "vcl_test_server [OPTIONS] <port>\n"
+	   "  OPTIONS\n"
+	   "  -h               Print this message and exit.\n"
+	   "  -6               Use IPv6\n"
+	   "  -w <num>         Number of workers\n"
+	   "  -D               Use UDP transport layer\n"
+	   "  -L               Use TLS transport layer\n");
+  exit (1);
+}
+
+static void
+vcl_test_init_endpoint_addr (vcl_test_server_main_t * vsm)
+{
+  struct sockaddr_storage *servaddr = &vsm->servaddr;
+  memset (servaddr, 0, sizeof (*servaddr));
+
+  if (vsm->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *server_addr = (struct sockaddr_in6 *) servaddr;
+      server_addr->sin6_family = AF_INET6;
+      server_addr->sin6_addr = in6addr_any;
+      server_addr->sin6_port = htons (vsm->cfg.port);
+    }
+  else
+    {
+      struct sockaddr_in *server_addr = (struct sockaddr_in *) servaddr;
+      server_addr->sin_family = AF_INET;
+      server_addr->sin_addr.s_addr = htonl (INADDR_ANY);
+      server_addr->sin_port = htons (vsm->cfg.port);
+    }
+
+  if (vsm->cfg.address_ip6)
+    {
+      struct sockaddr_in6 *server_addr = (struct sockaddr_in6 *) servaddr;
+      vsm->cfg.endpt.is_ip4 = 0;
+      vsm->cfg.endpt.ip = (uint8_t *) & server_addr->sin6_addr;
+      vsm->cfg.endpt.port = (uint16_t) server_addr->sin6_port;
+    }
+  else
+    {
+      struct sockaddr_in *server_addr = (struct sockaddr_in *) servaddr;
+      vsm->cfg.endpt.is_ip4 = 1;
+      vsm->cfg.endpt.ip = (uint8_t *) & server_addr->sin_addr;
+      vsm->cfg.endpt.port = (uint16_t) server_addr->sin_port;
+    }
+}
+
+static void
+vcl_test_server_process_opts (vcl_test_server_main_t * vsm, int argc,
+			      char **argv)
+{
+  int v, c;
+
+  vsm->cfg.proto = VPPCOM_PROTO_TCP;
+
+  opterr = 0;
+  while ((c = getopt (argc, argv, "6DLsw:")) != -1)
+    switch (c)
+      {
+      case '6':
+	vsm->cfg.address_ip6 = 1;
+	break;
+
+      case 'D':
+	vsm->cfg.proto = VPPCOM_PROTO_UDP;
+	break;
+
+      case 'L':
+	vsm->cfg.proto = VPPCOM_PROTO_TLS;
+	break;
+
+      case 'w':
+	v = atoi (optarg);
+	if (v > 1)
+	  vsm->cfg.workers = v;
+	else
+	  vtwrn ("Invalid number of workers %d", v);
+	break;
+      case 's':
+	vsm->use_ds = 1;
+	break;
+      case '?':
+	switch (optopt)
+	  {
+	  default:
+	    if (isprint (optopt))
+	      vtwrn ("Unknown option `-%c'.", optopt);
+	    else
+	      vtwrn ("Unknown option character `\\x%x'.", optopt);
+	  }
+	/* fall thru */
+      case 'h':
+      default:
+	print_usage_and_exit ();
+      }
+
+  if (argc < (optind + 1))
+    {
+      fprintf (stderr, "SERVER: ERROR: Insufficient number of arguments!\n");
+      print_usage_and_exit ();
+    }
+
+  if (sscanf (argv[optind], "%d", &v) == 1)
+    vsm->cfg.port = (uint16_t) v;
+  else
+    {
+      fprintf (stderr, "SERVER: ERROR: Invalid port (%s)!\n", argv[optind]);
+      print_usage_and_exit ();
+    }
+
+  vcl_test_init_endpoint_addr (vsm);
+}
+
+int
+vts_handle_cfg (vcl_test_server_worker_t * wrk, vcl_test_cfg_t * rx_cfg,
+		vcl_test_server_conn_t * conn, int rx_bytes)
+{
+  if (rx_cfg->verbose)
+    {
+      vtinf ("(fd %d): Received a cfg msg!", conn->fd);
+      vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
+    }
+
+  if (rx_bytes != sizeof (*rx_cfg))
+    {
+      vtinf ("(fd %d): Invalid cfg msg size %d expected %lu!", conn->fd,
+	     rx_bytes, sizeof (*rx_cfg));
+      conn->cfg.rxbuf_size = 0;
+      conn->cfg.num_writes = 0;
+      if (conn->cfg.verbose)
+	{
+	  vtinf ("(fd %d): Replying to cfg msg", conn->fd);
+	  vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
+	}
+      vcl_test_write (conn->fd, (uint8_t *) & conn->cfg,
+		      sizeof (conn->cfg), NULL, conn->cfg.verbose);
+      return -1;
+    }
+
+  switch (rx_cfg->test)
+    {
+    case VCL_TEST_TYPE_NONE:
+    case VCL_TEST_TYPE_ECHO:
+      sync_config_and_reply (conn, rx_cfg);
+      break;
+
+    case VCL_TEST_TYPE_BI:
+    case VCL_TEST_TYPE_UNI:
+      vts_server_start_stop (wrk, conn, rx_cfg);
+      break;
+
+    case VCL_TEST_TYPE_EXIT:
+      vtinf ("Session fd %d closing!", conn->fd);
+      clock_gettime (CLOCK_REALTIME, &conn->stats.stop);
+      vppcom_session_close (conn->fd);
+      conn_pool_free (conn);
+      wrk->nfds--;
+      break;
+
+    default:
+      vtwrn ("Unknown test type %d", rx_cfg->test);
+      vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
+      break;
+    }
+
+  return 0;
+}
+
+static void
+vts_worker_init (vcl_test_server_worker_t * wrk)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+  struct epoll_event listen_ev;
+  int rv;
+
+  __wrk_index = wrk->wrk_index;
+
+  vtinf ("Initializing worker ...");
+
+  conn_pool_expand (wrk, VCL_TEST_CFG_MAX_TEST_SESS + 1);
+  if (wrk->wrk_index)
+    if (vppcom_worker_register ())
+      vtfail ("vppcom_worker_register()", 1);
+
+  wrk->listen_fd = vppcom_session_create (vsm->cfg.proto,
+					  0 /* is_nonblocking */ );
+  if (wrk->listen_fd < 0)
+    vtfail ("vppcom_session_create()", wrk->listen_fd);
+
+
+  if (vsm->cfg.proto == VPPCOM_PROTO_TLS)
+    {
+      vppcom_session_tls_add_cert (wrk->listen_fd, vcl_test_crt_rsa,
+				   vcl_test_crt_rsa_len);
+      vppcom_session_tls_add_key (wrk->listen_fd, vcl_test_key_rsa,
+				  vcl_test_key_rsa_len);
+    }
+
+  rv = vppcom_session_bind (wrk->listen_fd, &vsm->cfg.endpt);
+  if (rv < 0)
+    vtfail ("vppcom_session_bind()", rv);
+
+  if (!(vsm->cfg.proto == VPPCOM_PROTO_UDP))
+    {
+      rv = vppcom_session_listen (wrk->listen_fd, 10);
+      if (rv < 0)
+	vtfail ("vppcom_session_listen()", rv);
+    }
+
+  wrk->epfd = vppcom_epoll_create ();
+  if (wrk->epfd < 0)
+    vtfail ("vppcom_epoll_create()", wrk->epfd);
+
+  listen_ev.events = EPOLLIN;
+  listen_ev.data.u32 = ~0;
+  rv = vppcom_epoll_ctl (wrk->epfd, EPOLL_CTL_ADD, wrk->listen_fd,
+			 &listen_ev);
+  if (rv < 0)
+    vtfail ("vppcom_epoll_ctl", rv);
+
+  vsm->active_workers += 1;
+  vtinf ("Waiting for a client to connect on port %d ...", vsm->cfg.port);
+}
+
+static int
+vts_conn_expect_config (vcl_test_server_conn_t * conn)
+{
+  if (conn->cfg.test == VCL_TEST_TYPE_ECHO)
+    return 1;
+
+  return (conn->stats.rx_bytes < 128
+	  || conn->stats.rx_bytes > conn->cfg.total_bytes);
+}
+
+static vcl_test_cfg_t *
+vts_conn_read_config (vcl_test_server_conn_t * conn)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+
+  if (vsm->use_ds)
+    {
+      /* We could avoid the copy if the first segment is big enough but this
+       * just simplifies things */
+      vppcom_data_segment_copy (conn->buf, conn->ds, sizeof (vcl_test_cfg_t));
+    }
+  return (vcl_test_cfg_t *) conn->buf;
+}
+
+static inline int
+vts_conn_read (vcl_test_server_conn_t * conn)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+  if (vsm->use_ds)
+    return vcl_test_read_ds (conn->fd, conn->ds, &conn->stats);
+  else
+    return vcl_test_read (conn->fd, conn->buf, conn->buf_size, &conn->stats);
+}
+
+static inline int
+vts_conn_has_ascii (vcl_test_server_conn_t * conn)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+
+  if (vsm->use_ds)
+    return isascii (conn->ds[0].data[0]);
+  else
+    return isascii (conn->buf[0]);
+}
+
+static void *
+vts_worker_loop (void *arg)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+  vcl_test_server_worker_t *wrk = arg;
+  vcl_test_server_conn_t *conn;
+  int i, rx_bytes, num_ev;
+  vcl_test_cfg_t *rx_cfg;
+
+  if (wrk->wrk_index)
+    vts_worker_init (wrk);
+
+  while (1)
+    {
+      num_ev = vppcom_epoll_wait (wrk->epfd, wrk->wait_events,
+				  VCL_TEST_CFG_MAX_EPOLL_EVENTS, 60000.0);
+      if (num_ev < 0)
+	{
+	  vterr ("vppcom_epoll_wait()", num_ev);
+	  goto fail;
+	}
+      else if (num_ev == 0)
+	{
+	  vtinf ("vppcom_epoll_wait() timeout!");
+	  continue;
+	}
+      for (i = 0; i < num_ev; i++)
+	{
+	  conn = &wrk->conn_pool[wrk->wait_events[i].data.u32];
+	  if (wrk->wait_events[i].events & (EPOLLHUP | EPOLLRDHUP))
+	    {
+	      vppcom_session_close (conn->fd);
+	      wrk->nfds -= 1;
+	      if (!wrk->nfds)
+		{
+		  vtinf ("All client connections closed\n");
+		  goto done;
+		}
+	      continue;
+	    }
+	  if (wrk->wait_events[i].data.u32 == ~0)
+	    {
+	      vts_new_client (wrk);
+	      continue;
+	    }
+
+	  if (EPOLLIN & wrk->wait_events[i].events)
+	    {
+	    read_again:
+	      rx_bytes = vts_conn_read (conn);
+
+	      if (rx_bytes <= 0)
+		{
+		  if (errno == ECONNRESET)
+		    {
+		      vtinf ("Connection reset by remote peer.\n");
+		      goto fail;
+		    }
+		  else
+		    continue;
+		}
+
+	      if (vts_conn_expect_config (conn))
+		{
+		  rx_cfg = vts_conn_read_config (conn);
+		  if (rx_cfg->magic == VCL_TEST_CFG_CTRL_MAGIC)
+		    {
+		      if (vsm->use_ds)
+			vppcom_session_free_segments (conn->fd, conn->ds);
+		      vts_handle_cfg (wrk, rx_cfg, conn, rx_bytes);
+		      if (!wrk->nfds)
+			{
+			  vtinf ("All client connections closed\n");
+			  goto done;
+			}
+		      continue;
+		    }
+		}
+	      if ((conn->cfg.test == VCL_TEST_TYPE_UNI)
+		  || (conn->cfg.test == VCL_TEST_TYPE_BI))
+		{
+		  vts_server_rx (conn, rx_bytes);
+		  if (vppcom_session_attr (conn->fd, VPPCOM_ATTR_GET_NREAD, 0,
+					   0) > 0)
+		    goto read_again;
+		  continue;
+		}
+	      if (vts_conn_has_ascii (conn))
+		{
+		  vts_server_echo (conn, rx_bytes);
+		}
+	      else
+		{
+		  vtwrn ("FIFO not drained! extra bytes %d", rx_bytes);
+		}
+	    }
+	  else
+	    {
+	      vtwrn ("Unhandled event");
+	      goto fail;
+	    }
+	}
+    }
+
+fail:
+  vsm->worker_fails -= 1;
+
+done:
+  vppcom_session_close (wrk->listen_fd);
+  if (wrk->conn_pool)
+    free (wrk->conn_pool);
+  vsm->active_workers -= 1;
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  vcl_test_server_main_t *vsm = &vcl_server_main;
+  int rv, i;
+
+  clib_mem_init_thread_safe (0, 64 << 20);
+  vsm->cfg.port = VCL_TEST_SERVER_PORT;
+  vsm->cfg.workers = 1;
+  vsm->active_workers = 0;
+  vcl_test_server_process_opts (vsm, argc, argv);
+
+  rv = vppcom_app_create ("vcl_test_server");
+  if (rv)
+    vtfail ("vppcom_app_create()", rv);
+
+  vsm->workers = calloc (vsm->cfg.workers, sizeof (*vsm->workers));
+  vts_worker_init (&vsm->workers[0]);
+  for (i = 1; i < vsm->cfg.workers; i++)
+    {
+      vsm->workers[i].wrk_index = i;
+      rv = pthread_create (&vsm->workers[i].thread_handle, NULL,
+			   vts_worker_loop, (void *) &vsm->workers[i]);
+    }
+  vts_worker_loop (&vsm->workers[0]);
+
+  while (vsm->active_workers > 0)
+    ;
+
+  vppcom_app_destroy ();
+  free (vsm->workers);
+
+  return vsm->worker_fails;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */