ci: added standard set of network suite for lwip as a part of weekend test

.gitlab-ci.yml

@@ -1079,6 +1079,23 @@ test_weekend_mqtt:
     ENV_FILE: "$CI_PROJECT_DIR/components/mqtt/weekend_test/env.yml"
     CONFIG_FILE: "$CI_PROJECT_DIR/components/mqtt/weekend_test/config.yml"
 
+test_weekend_network:
+  <<: *example_test_template
+  stage: target_test
+  image: $CI_DOCKER_REGISTRY/rpi-net-suite$BOT_DOCKER_IMAGE_TAG
+  tags:
+    - ESP32
+    - Example_WIFI
+  only:
+    variables:
+      - $BOT_LABEL_WEEKEND_TEST
+  variables:
+    TEST_CASE_PATH: "$CI_PROJECT_DIR/components/lwip/weekend_test"
+    TEST_FW_PATH: "$CI_PROJECT_DIR/tools/tiny-test-fw"
+    LOG_PATH: "$CI_PROJECT_DIR/TEST_LOGS"
+    ENV_FILE: "$CI_PROJECT_DIR/components/lwip/weekend_test/env.yml"
+    CONFIG_FILE: "$CI_PROJECT_DIR/components/lwip/weekend_test/config.yml"
+
 .test_template: &test_template
   stage: target_test
   when: on_success

components/lwip/CMakeLists.txt

@@ -87,6 +87,7 @@ set(COMPONENT_SRCS "apps/dhcpserver/dhcpserver.c"
                    "port/esp32/freertos/sys_arch.c"
                    "port/esp32/netif/dhcp_state.c"
                    "port/esp32/netif/ethernetif.c"
+                   "port/esp32/netif/nettestif.c"
                    "port/esp32/netif/wlanif.c")
 
 if(CONFIG_LWIP_PPP_SUPPORT)

components/lwip/port/esp32/include/netif/nettestif.h

@@ -0,0 +1,33 @@
+// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// 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 _NETTEST_LWIP_IF_H_
+#define _NETTEST_LWIP_IF_H_
+
+#include "lwip/err.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+err_t nettestif_init(struct netif *netif);
+
+void nettestif_input(void *buffer, u16_t len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*  _NETTEST_LWIP_IF_H_ */

components/lwip/port/esp32/netif/dhcp_state.c

@@ -26,7 +26,7 @@
 #define VALID_NETIF_ID(id) ((id < ESP_IF_MAX) && (id != ESP_IF_WIFI_AP))
 
 static uint32_t restored_ip_addr[TCPIP_ADAPTER_IF_MAX];
-static const char *interface_key[] = {"IF_STA", "IF_AP", "IF_ETH"};
+static const char *interface_key[] = {"IF_STA", "IF_AP", "IF_ETH", "IF_TEST"};
 
 _Static_assert(sizeof(interface_key) / sizeof(char*) == TCPIP_ADAPTER_IF_MAX,
                "Number interface keys differs from number of interfaces");

components/lwip/port/esp32/netif/nettestif.c

@@ -0,0 +1,105 @@
+
+#include "lwip/opt.h"
+
+#include "lwip/def.h"
+#include "lwip/mem.h"
+#include "lwip/pbuf.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "lwip/ethip6.h"
+#include "netif/etharp.h"
+#include "netif/wlanif.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include "tcpip_adapter.h"
+
+static struct netif *g_last_netif = NULL;
+
+
+err_t nettestif_output(struct netif *netif, struct pbuf *p)
+{
+  int i;
+  char *dat = p->payload;
+
+  /* output the packet to stdout */
+  printf("\nPacketOut:[");
+  for (i=0; i<p->len; i++) {
+    printf("%02x", *dat++);
+  }
+  printf("]\n");
+
+  return ERR_OK;
+}
+
+
+err_t nettestif_init(struct netif *netif)
+{
+
+  g_last_netif = netif;
+
+  netif->hostname = "espressif";
+
+  /*
+   * Initialize the snmp variables and counters inside the struct netif.
+   * The last argument should be replaced with your link speed, in units
+   * of bits per second.
+   */
+  NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 100);
+
+  /* We directly use etharp_output() here to save a function call.
+   * You can instead declare your own function an call etharp_output()
+   * from it if you have to do some checks before sending (e.g. if link
+   * is available...) */
+  netif->output = etharp_output;
+#if LWIP_IPV6
+  netif->output_ip6 = ethip6_output;
+#endif /* LWIP_IPV6 */
+  netif->linkoutput = nettestif_output;
+   /* set MAC hardware address length */
+  netif->hwaddr_len = ETHARP_HWADDR_LEN;
+
+  /* set MAC hardware address */
+
+  /* maximum transfer unit */
+  netif->mtu = 1500;
+
+  /* device capabilities */
+  /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
+  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
+
+#if ESP_LWIP
+#if LWIP_IGMP
+  netif->flags |= NETIF_FLAG_IGMP;
+#endif
+#endif
+  return ERR_OK;
+
+}
+
+void nettestif_input(void *buffer, u16_t len)
+{
+  struct pbuf *p;
+  if (g_last_netif == NULL) {
+    printf("error!");
+    return;
+  }
+
+  printf("simul in: %d\n", len);
+  if (len==0) return;
+
+  p = pbuf_alloc(PBUF_RAW, len, PBUF_RAM);
+  p->l2_owner = NULL;
+  memcpy(p->payload, buffer, len);
+
+  /* full packet send to tcpip_thread to process
+   * on success - the packet is processed and deallocated in tcpip stack
+   * on failure - log error and deallocate the packet
+   */
+  if (g_last_netif->input(p, g_last_netif) != ERR_OK) {
+    LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
+    pbuf_free(p);
+  }
+
+}

components/lwip/weekend_test/config.yml

@@ -0,0 +1,3 @@
+CaseConfig:
+- name: lwip_test_suite
+

components/lwip/weekend_test/esp32_netsuite.cfg

@@ -0,0 +1,11 @@
+[LOGGING]
+FileMask := LOG_ALL | DEBUG | TTCN_DEBUG
+ConsoleMask := LOG_ALL | DEBUG | TTCN_DEBUG
+LogSourceInfo := Yes
+
+[MODULE_PARAMETERS]
+libtest.m_ip_dst := "10.0.0.1"
+libtest.m_ip_src := "10.0.0.2"
+
+[EXECUTE]
+esp32_netsuite.control

components/lwip/weekend_test/esp32_netsuite.ttcn

@@ -0,0 +1,11 @@
+module esp32_netsuite {
+import from tcp_suite all;
+
+control {
+    execute(tc_tcp_002());
+    execute(tc_tcp_003());
+    execute(tc_tcp_004());
+    execute(tc_tcp_005());
+}
+
+}

components/lwip/weekend_test/net_suite_test.py

@@ -0,0 +1,164 @@
+import re
+import os
+import sys
+import socket
+from threading import Thread, Event
+import subprocess
+import time
+from shutil import copyfile
+
+try:
+    import IDF
+except ImportError:
+    # this is a test case write with tiny-test-fw.
+    # to run test cases outside tiny-test-fw,
+    # we need to set environment variable `TEST_FW_PATH`,
+    # then get and insert `TEST_FW_PATH` to sys path before import FW module
+    test_fw_path = os.getenv("TEST_FW_PATH")
+    if test_fw_path and test_fw_path not in sys.path:
+        sys.path.insert(0, test_fw_path)
+    import IDF
+
+import DUT
+import Utility
+
+stop_sock_listener = Event()
+stop_io_listener = Event()
+sock = None
+client_address = None
+manual_test = False
+
+
+def io_listener(dut1):
+    global sock
+    global client_address
+    data = b''
+    while not stop_io_listener.is_set():
+        try:
+            data = dut1.expect(re.compile(r"PacketOut:\[([a-fA-F0-9]+)\]"), timeout=5)
+        except DUT.ExpectTimeout:
+            continue
+        if data != () and data[0] != b'':
+            packet_data = data[0]
+            print("Packet_data>{}<".format(packet_data))
+            response = bytearray.fromhex(packet_data.decode())
+            print("Sending to socket:")
+            packet = ' '.join(format(x, '02x') for x in bytearray(response))
+            print("Packet>{}<".format(packet))
+            if client_address is not None:
+                sock.sendto(response, ('127.0.0.1', 7777))
+
+
+def sock_listener(dut1):
+    global sock
+    global client_address
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.settimeout(5)
+    server_address = '0.0.0.0'
+    server_port = 7771
+    server = (server_address, server_port)
+    sock.bind(server)
+    try:
+        while not stop_sock_listener.is_set():
+            try:
+                payload, client_address = sock.recvfrom(1024)
+                packet = ' '.join(format(x, '02x') for x in bytearray(payload))
+                print("Received from address {}, data {}".format(client_address, packet))
+                dut1.write(str.encode(packet))
+            except socket.timeout:
+                pass
+    finally:
+        sock.close()
+        sock = None
+
+
+@IDF.idf_example_test(env_tag="Example_WIFI")
+def lwip_test_suite(env, extra_data):
+    global stop_io_listener
+    global stop_sock_listener
+    """
+    steps: |
+      1. Rebuilds test suite with esp32_netsuite.ttcn
+      2. Starts listeners on stdout and socket
+      3. Execute ttcn3 test suite
+      4. Collect result from ttcn3
+    """
+    dut1 = env.get_dut("net_suite", "examples/system/network_tests")
+    # check and log bin size
+    binary_file = os.path.join(dut1.app.binary_path, "net_suite.bin")
+    bin_size = os.path.getsize(binary_file)
+    IDF.log_performance("net_suite", "{}KB".format(bin_size // 1024))
+    IDF.check_performance("net_suite", bin_size // 1024)
+    dut1.start_app()
+    thread1 = Thread(target=sock_listener, args=(dut1, ))
+    thread2 = Thread(target=io_listener, args=(dut1, ))
+    if not manual_test:
+        # Variables refering to esp32 ttcn test suite
+        TTCN_SRC = 'esp32_netsuite.ttcn'
+        TTCN_CFG = 'esp32_netsuite.cfg'
+        # System Paths
+        netsuite_path = os.getenv("NETSUITE_PATH")
+        netsuite_src_path = os.path.join(netsuite_path, "src")
+        test_dir = os.path.dirname(os.path.realpath(__file__))
+        # Building the suite
+        print("Rebuilding the test suite")
+        print("-------------------------")
+        # copy esp32 specific files to ttcn net-suite dir
+        copyfile(os.path.join(test_dir, TTCN_SRC), os.path.join(netsuite_src_path, TTCN_SRC))
+        copyfile(os.path.join(test_dir, TTCN_CFG), os.path.join(netsuite_src_path, TTCN_CFG))
+        proc = subprocess.Popen(['bash', '-c', 'cd ' + netsuite_src_path + ' && source make.sh'],
+                                cwd=netsuite_path, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        output = proc.stdout.read()
+        print("Note: First build step we expect failure (titan/net_suite build system not suitable for multijob make)")
+        print(output)
+        proc = subprocess.Popen(['bash', '-c', 'cd ' + netsuite_src_path + ' && make'],
+                                cwd=netsuite_path, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        print("Note: This time all dependencies shall be generated -- multijob make shall pass")
+        output = proc.stdout.read()
+        print(output)
+        # Executing the test suite
+        thread1.start()
+        thread2.start()
+        time.sleep(2)
+        print("Executing the test suite")
+        print("------------------------")
+        proc = subprocess.Popen(['ttcn3_start', os.path.join(netsuite_src_path,'test_suite'), os.path.join(netsuite_src_path, TTCN_CFG)],
+                                stdout=subprocess.PIPE)
+        output = proc.stdout.read()
+        print(output)
+        print("Collecting results")
+        print("------------------")
+        verdict_stats = re.search('(Verdict statistics:.*)', output)
+        if verdict_stats:
+            verdict_stats = verdict_stats.group(1)
+        else:
+            verdict_stats = b""
+        verdict = re.search('Overall verdict: pass', output)
+        if verdict:
+            print("Test passed!")
+            Utility.console_log(verdict_stats, "green")
+        else:
+            Utility.console_log(verdict_stats, "red")
+            raise ValueError('Test failed with: {}'.format(verdict_stats))
+    else:
+        try:
+            # Executing the test suite
+            thread1.start()
+            thread2.start()
+            time.sleep(2)
+            while True:
+                time.sleep(0.5)
+        except KeyboardInterrupt:
+            pass
+    print("Executing done, waiting for tests to finish")
+    print("-------------------------------------------")
+    stop_io_listener.set()
+    stop_sock_listener.set()
+    thread1.join()
+    thread2.join()
+
+
+if __name__ == '__main__':
+    print("Manual execution, please build and start ttcn in a separate console")
+    manual_test = True
+    lwip_test_suite()

components/tcpip_adapter/include/tcpip_adapter.h

@@ -96,6 +96,7 @@ typedef enum {
     TCPIP_ADAPTER_IF_STA = 0,     /**< Wi-Fi STA (station) interface */
     TCPIP_ADAPTER_IF_AP,          /**< Wi-Fi soft-AP interface */
     TCPIP_ADAPTER_IF_ETH,         /**< Ethernet interface */
+    TCPIP_ADAPTER_IF_TEST,        /**< tcpip stack test interface */
     TCPIP_ADAPTER_IF_MAX
 } tcpip_adapter_if_t;
 
@@ -692,6 +693,19 @@ esp_err_t tcpip_adapter_get_netif(tcpip_adapter_if_t tcpip_if, void ** netif);
  */
 bool tcpip_adapter_is_netif_up(tcpip_adapter_if_t tcpip_if);
 
+/**
+ * @brief  Cause the TCP/IP stack to start the test interface with specified MAC and IP.
+ * Test interface is used to exercise network stack with injected packets from SW.
+ *
+ * @param[in]  mac Set MAC address of this interface
+ * @param[in]  ip_info Set IP address of this interface
+ *
+ * @return
+ *         - ESP_OK
+ *         - ESP_ERR_TCPIP_ADAPTER_INVALID_PARAMS
+ *         - ESP_ERR_NO_MEM
+ */
+esp_err_t tcpip_adapter_test_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info);
 
 /**
  * @brief  Install default event handlers for Ethernet interface

components/tcpip_adapter/tcpip_adapter_lwip.c

@@ -32,6 +32,7 @@
 #endif
 #include "netif/wlanif.h"
 #include "netif/ethernetif.h"
+#include "netif/nettestif.h"
 
 #include "dhcpserver/dhcpserver.h"
 #include "dhcpserver/dhcpserver_options.h"
@@ -161,6 +162,8 @@ static esp_err_t tcpip_adapter_update_default_netif(void)
         netif_set_default(esp_netif[TCPIP_ADAPTER_IF_ETH]);
     } else if (netif_is_up(esp_netif[TCPIP_ADAPTER_IF_AP])) {
         netif_set_default(esp_netif[TCPIP_ADAPTER_IF_AP]);
+    } else if (netif_is_up(esp_netif[TCPIP_ADAPTER_IF_TEST])) {
+        netif_set_default(esp_netif[TCPIP_ADAPTER_IF_TEST]);
     }
 
     return ESP_OK;
@@ -210,6 +213,8 @@ static esp_err_t tcpip_adapter_start(tcpip_adapter_if_t tcpip_if, uint8_t *mac,
 
             dhcps_status = TCPIP_ADAPTER_DHCP_STARTED;
         }
+    } else if (tcpip_if == TCPIP_ADAPTER_IF_TEST) {
+        netif_set_up(esp_netif[tcpip_if]);
     }
 
     tcpip_adapter_update_default_netif();
@@ -229,6 +234,13 @@ esp_err_t tcpip_adapter_sta_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info
      return tcpip_adapter_start(TCPIP_ADAPTER_IF_STA, mac, ip_info);
 }
 
+esp_err_t tcpip_adapter_test_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info)
+{
+     esp_netif_init_fn[TCPIP_ADAPTER_IF_TEST] = nettestif_init;
+     return tcpip_adapter_start(TCPIP_ADAPTER_IF_TEST, mac, ip_info);
+}
+
+
 esp_err_t tcpip_adapter_ap_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info)
 {
      esp_netif_init_fn[TCPIP_ADAPTER_IF_AP] = wlanif_init_ap;

examples/system/network_tests/CMakeLists.txt

@@ -0,0 +1,6 @@
+# The following lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(net_suite)

examples/system/network_tests/Makefile

@@ -0,0 +1,9 @@
+#
+# This is a project Makefile. It is assumed the directory this Makefile resides in is a
+# project subdirectory.
+#
+
+PROJECT_NAME := net_suite
+
+include $(IDF_PATH)/make/project.mk
+

examples/system/network_tests/README.md

@@ -0,0 +1,66 @@
+# Intel net test suite for LwIP network stack
+
+This project provides a test interface to esp32 network stack in order to execute standard set of
+Intel network test suite defined in TTCN3 framework.
+
+## Important notice
+*This is an internal ESP-IDF test and not a user project example*
+
+##  Execute  net test suite
+
+These network tests could be executed in both manual or automated mode in CI.
+
+Note: TTCN3 engine works reliably only on Linux and Windows.
+
+## Setup TTCN3
+
+* Clone a repository https://github.com/intel/net-test-suites.git and install titan core a described in the README.md
+* Copy files `esp32_netsuite.cfg` and `esp32_netsuite.ttcn` (located in `$IDF_PATH/components/lwip/weekend_test`) to `src` subdir of the cloned repository `net-test-suites`
+* Rebuild the netsuite tests (according to README.md in net-test-suite) by executing `source make.sh` in `src` subdir
+
+
+## Build application
+
+```
+cd $IDF_PATH/examples/system/network_tests
+make defconfig
+make -j4
+make flash
+```
+
+## Run test
+Open two terminals (1) and (2)
+1) Start the test server which would pass packets from TTCN3 test suite into ESP32 board in `$IDF_PATH/components/lwip/weekend_test`
+```
+python net_suite_test.py
+```
+
+2) Start test suite in TTCN3 environment in `src` subdir of the cloned repository `net-test-suites.git`
+```
+ttcn3_start test_suite esp32_netsuite.cfg
+```
+
+## Internal connection
+
+Purpose of this test is to execute standard network suite on a ESP32 network stack.
+
+DUT (Network stack under test) runs normally on target, but a specific interface `TCPIP_ADAPTER_IF_TEST` was created for passing arbitrary data to
+and from the network stack. Embedded code `net_suite.c` implements an application which serves stdin/stdout and propagates the data to/from this test interface.
+
+Standard Intel net suite executed by TTCN3 engine uses udp ports for input/ouput of network packets. Python script `net_suite.py` translates this communication 
+from/to those udp ports to stdin/stdout, where after propagating over USB/UART to the ESP32 board are processed in the network stack (on the target).
+
+Actual test execution, progress, evaluation and test reporting is done using standard net-test-suite scripts running on PC.
+
+```
+  PC
++---------------------------------------------------------+       ESP32 board
+|                                                         |    +----------------------------------------+
+|  TTCN3 engine                                           |    |  +----------------------------------+  |
+|                                                         |    |  | net_suite.c                      |  |
+| +-----------------+            +--------------+         |    |  |         +------------------------+  |
+| | net-test-suite  |--7777/udp--| net_suite.py |--stdout---------| ----->  | tcpip_adapter/lwip     |  |
+| |                 |--7771/udp--|              |--stdin----------| <-----  |  TCPIP_ADAPTER_IF_TEST |  |
+| +-----------------+            +--------------+         |    |  +---------+------------------------+  |
++---------------------------------------------------------+    +----------------------------------------+
+```

examples/system/network_tests/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+set(COMPONENT_SRCS "net_suite.c")
+set(COMPONENT_ADD_INCLUDEDIRS ".")
+
+register_component()

examples/system/network_tests/main/component.mk

@@ -0,0 +1,8 @@
+#
+# Main component makefile.
+#
+# This Makefile can be left empty. By default, it will take the sources in the 
+# src/ directory, compile them and link them into lib(subdirectory_name).a 
+# in the build directory. This behaviour is entirely configurable,
+# please read the ESP-IDF documents if you need to do this.
+#

examples/system/network_tests/main/net_suite.c

@@ -0,0 +1,180 @@
+/* Net-suite test code
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/event_groups.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "esp_event_loop.h"
+#include "esp_log.h"
+#include "nvs_flash.h"
+#include "driver/uart.h"
+#include "esp_console.h"
+#include "esp_vfs_dev.h"
+#include "linenoise/linenoise.h"
+
+#include "lwip/err.h"
+#include "lwip/sys.h"
+#include "lwip/debug.h"
+#include "lwip/stats.h"
+#include "lwip/tcp.h"
+void nettestif_input(void *buffer, u16_t len);
+
+/* these data configures ARP cache so the test IPs are knows */
+static char arp1[] = {
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06, 0x00, 0x01, 0x08, 0x00, 0x06, 
+    0x04, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x0a, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x0a, 0x00, 0x00, 0x01
+};
+
+/* Test data (ICMP packet) for verification of tcp ip test netif
+    00-00-00-00-00-01-00-00-00-00-00-02-08-00-45-00-00-1c-00-00-00-00-ff-01-a7-de-0a-00-00-02-0a-00-00-01-08-00-f7-fd-00-01-00-01
+*/
+
+/* creating test pcb */
+static struct tcp_pcb *test_pcb;
+
+err_t test_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
+{
+    return ERR_OK;
+}
+
+void test_error(void *arg, err_t err)
+{
+    printf("Error CB from pcb %d\n", err);
+}
+
+err_t test_poll(void *arg, struct tcp_pcb *tpcb)
+{
+    return ERR_OK;
+}
+
+err_t test_accept(void *arg, struct tcp_pcb *newpcb, err_t err)
+{
+    LWIP_UNUSED_ARG(arg);
+    LWIP_UNUSED_ARG(err);
+
+    tcp_setprio(newpcb, TCP_PRIO_MIN);
+    tcp_arg(newpcb, NULL);
+    tcp_recv(newpcb, test_recv);
+    tcp_err(newpcb, test_error);
+    tcp_poll(newpcb, test_poll, 0);
+
+    return ERR_OK;
+}
+
+void test_tcp_init(void)
+{
+    test_pcb = tcp_new();
+    if (test_pcb != NULL) {
+        err_t err;
+        /* Binding this test_pcb to 4242 to accept connections on this port
+         * - this has to be configured as DUT endpoint
+         * - all network traffic from and to network stack is tracked in nettestif
+         */
+        err = tcp_bind(test_pcb, IP_ADDR_ANY, 4242);
+        if (err == ERR_OK) {
+            test_pcb = tcp_listen(test_pcb);
+            tcp_accept(test_pcb, test_accept);
+        } else  {
+            printf("cannot bind test_pcb\n");
+            abort();
+        }
+    } else  {
+        printf("cannot create test_pcb\n");
+        abort();
+    }
+}
+
+/**
+ * @brief Process line read from serial input, character by character
+ *
+ * Converts from hex string to byte stream, so it can be processed
+ * in test network interface
+ *
+ * @param line
+ * @param packet
+ *
+ * @return size of packet
+ */
+static size_t process_line(char* line, char* packet)
+{
+    size_t count = 0;
+    size_t i;
+
+    for (i=0; i< strlen(line); i++) {
+        char c = line[i];
+        // accept both separators between bytes
+        if (c == '-' || c == ' ') {
+            ++count;
+        // Processing numeric characters
+        } else if (c >= '0' && c <= '9') {
+            packet[count] *= 16;
+            packet[count] += c - '0';
+        // Processing alpha-numeric hex characters
+        } else if (c >= 'a' && c <= 'f') {
+            packet[count] *= 16;
+            packet[count] += c - 'a' + 10;
+        }
+    }
+
+    if (i>0 && strlen(line)>0) {
+        count++;
+    }
+    return count;
+}
+
+void app_main()
+{
+    char packet[128];
+
+    tcpip_adapter_ip_info_t ip_info;
+
+    uint8_t ap_mac[6] = { 0,0,0,0,0,1};
+    IP4_ADDR(&ip_info.ip, 10, 0 , 0, 1);
+    IP4_ADDR(&ip_info.gw, 10, 0 , 0, 1);
+    IP4_ADDR(&ip_info.netmask, 255, 255 , 255, 0);    
+
+    tcpip_adapter_init();
+
+    tcpip_adapter_test_start(ap_mac, &ip_info);
+
+    // initializes TCP endpoint on DUT per https://github.com/intel/net-test-suites#21-endpoints
+    test_tcp_init();
+    // Inject ARP packet to let the network stack know about IP/MAC of the counterpart
+    nettestif_input(arp1, sizeof(arp1));
+    // Initialize VFS & UART so we can use std::cout/cin
+    setvbuf(stdin, NULL, _IONBF, 0);
+    setvbuf(stdout, NULL, _IONBF, 0);
+    /* Install UART driver for interrupt-driven reads and writes */
+    ESP_ERROR_CHECK( uart_driver_install( (uart_port_t)CONFIG_CONSOLE_UART_NUM,
+            256, 0, 0, NULL, 0) );
+    /* Tell VFS to use UART driver */
+    esp_vfs_dev_uart_use_driver(CONFIG_CONSOLE_UART_NUM);
+    esp_vfs_dev_uart_set_rx_line_endings(ESP_LINE_ENDINGS_CR);
+    /* Move the caret to the beginning of the next line on '\n' */
+    esp_vfs_dev_uart_set_tx_line_endings(ESP_LINE_ENDINGS_CRLF);
+    linenoiseSetDumbMode(1);
+
+    /* Now read from stdin and pass the data to test netif */
+    while (1) {
+        size_t size;
+        char* line = linenoise("");
+        if (!line) {
+            continue;
+        }
+
+        size = process_line(line, packet);
+
+        nettestif_input(packet, size);
+
+        linenoiseFree(line);
+    }
+
+}