Add TCP echo server from Max Holtzberg

8 files changed, 582 insertions, 3 deletions

diff --git a/apps/ChangeLog.txt b/apps/ChangeLog.txt
index e6ceed475..474c1fd63 100644
--- a/apps/ChangeLog.txt
+++ b/apps/ChangeLog.txt
@@ -557,4 +557,6 @@
 	  example is built as an NSH built-in application.  (2013-5-16).
 	* apps/netutils/discover:  Added a runtime configuration for the
 	  UDP discover utility.  From Max Holtzberg (2013-5-21).
-
+	* apps/examples/tcpecho:  Added a simple single threaded, poll based
+ 	  TCP echo server based on W. Richard Stevens UNIX Network Programming
+	  Book.  Contributed by Max Holtberg (2013-5-22).
diff --git a/apps/examples/Kconfig b/apps/examples/Kconfig
index 11a56a81c..97e6ce140 100644
--- a/apps/examples/Kconfig
+++ b/apps/examples/Kconfig
@@ -50,6 +50,7 @@ source "$APPSDIR/examples/serloop/Kconfig"
 source "$APPSDIR/examples/flash_test/Kconfig"
 source "$APPSDIR/examples/smart_test/Kconfig"
 source "$APPSDIR/examples/smart/Kconfig"
+source "$APPSDIR/examples/tcpecho/Kconfig"
 source "$APPSDIR/examples/telnetd/Kconfig"
 source "$APPSDIR/examples/thttpd/Kconfig"
 source "$APPSDIR/examples/tiff/Kconfig"
diff --git a/apps/examples/Make.defs b/apps/examples/Make.defs
index 67b07a21b..28399192b 100644
--- a/apps/examples/Make.defs
+++ b/apps/examples/Make.defs
@@ -226,6 +226,10 @@ ifeq ($(CONFIG_EXAMPLES_SMART),y)
 CONFIGURED_APPS += examples/smart
 endif
 
+ifeq ($(CONFIG_EXAMPLES_TCPECHO),y)
+CONFIGURED_APPS += examples/tcpecho
+endif
+
 ifeq ($(CONFIG_EXAMPLES_TELNETD),y)
 CONFIGURED_APPS += examples/telnetd
 endif
diff --git a/apps/examples/Makefile b/apps/examples/Makefile
index 7827bf9a3..2ffe131c6 100644
--- a/apps/examples/Makefile
+++ b/apps/examples/Makefile
@@ -42,7 +42,7 @@ SUBDIRS += flash_test ftpc ftpd hello helloxx hidkbd igmp json keypadtest
 SUBDIRS += lcdrw mm modbus mount mtdpart nettest nsh null nx nxconsole nxffs
 SUBDIRS += nxflat nxhello nximage nxlines nxtext ostest  pashello pipe poll
 SUBDIRS += posix_spawn pwm qencoder relays rgmp romfs sendmail serloop
-SUBDIRS += smart smart_test telnetd thttpd tiff touchscreen udp uip
+SUBDIRS += smart smart_test tcpecho telnetd thttpd tiff touchscreen udp uip
 SUBDIRS += usbserial usbstorage usbterm watchdog wget wgetjson xmlrpc
 
 # Sub-directories that might need context setup.  Directories may need
@@ -60,7 +60,7 @@ CNTXTDIRS = pwm
 ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
 CNTXTDIRS += adc can cdcacm composite cxxtest dhcpd discover flash_test ftpd
 CNTXTDIRS += hello helloxx json keypadtestmodbus mtdpart nettest nxlines relays
-CNTXTDIRS += qencoder smart_test telnetd watchdog wgetjson
+CNTXTDIRS += qencoder smart_test tcpecho telnetd watchdog wgetjson
 endif
 
 ifeq ($(CONFIG_EXAMPLES_LCDRW_BUILTIN),y)
diff --git a/apps/examples/README.txt b/apps/examples/README.txt
index b41e2f4c2..ac922a703 100644
--- a/apps/examples/README.txt
+++ b/apps/examples/README.txt
@@ -727,6 +727,8 @@ examples/nettest
 
   CONFIGURED_APPS += uiplib
 
+  See also examples/tcpecho
+
 examples/nsh
 ^^^^^^^^^^^^
 
@@ -1508,6 +1510,25 @@ examples/smart_test
     * CONFIG_NSH_BUILTIN_APPS=y: This test can be built only as an NSH
       command
 
+examples/tcpecho
+^^^^^^^^^^^^^^^^
+
+  Simple single threaded, poll based TCP echo server. This example implements
+  the TCP Echo Server from W. Richard Stevens UNIX Network Programming Book.
+  Contributed by Max Holtberg.
+
+  See also examples/nettest
+
+    * CONFIG_EXAMPLES_TCPECHO =y: Enables the TCP echo server.
+    * CONFIG_XAMPLES_TCPECHO_PORT: Server Port, default 80
+    * CONFIG_EXAMPLES_TCPECHO_BACKLOG: Listen Backlog, default 8
+    * CONFIG_EXAMPLES_TCPECHO_NCONN: Number of Connections, default 8
+    * CONFIG_EXAMPLES_TCPECHO_DHCPC: DHCP Client, default n
+    * CONFIG_EXAMPLES_TCPECHO_NOMAC: Use Canned MAC Address, default n
+    * CONFIG_EXAMPLES_TCPECHO_IPADDR: Target IP address, default 0x0a000002
+    * CONFIG_EXAMPLES_TCPECHO_DRIPADDR: Default Router IP address (Gateway), default 0x0a000001
+    * CONFIG_EXAMPLES_TCPECHO_NETMASK: Network Mask, default 0xffffff00
+
 examples/telnetd
 ^^^^^^^^^^^^^^^^
 
diff --git a/apps/examples/tcpecho/Kconfig b/apps/examples/tcpecho/Kconfig
new file mode 100644
index 000000000..cc063e0a5
--- /dev/null
+++ b/apps/examples/tcpecho/Kconfig
@@ -0,0 +1,54 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config EXAMPLES_TCPECHO
+	bool "Simple TCP echo server"
+	default n
+	---help---
+		Simple single threaded, poll based TCP echo server. This example
+		implements the TCP Echo Server from W. Richard Stevens
+		UNIX Network Programming Book.
+
+config EXAMPLES_TCPECHO_PORT
+	int "Server Port"
+	default 80
+	depends on EXAMPLES_TCPECHO
+
+config EXAMPLES_TCPECHO_BACKLOG
+	int "Listen Backlog"
+	default 8
+	depends on EXAMPLES_TCPECHO
+
+config EXAMPLES_TCPECHO_NCONN
+	int "Number of Connections"
+	default 8
+	depends on EXAMPLES_TCPECHO
+
+config EXAMPLES_TCPECHO_DHCPC
+	bool "DHCP Client"
+	default n
+	depends on EXAMPLES_TCPECHO && !NSH_BUILTIN_APPS
+	select NETUTILS_DHCPC
+	select NETUTILS_RESOLV
+
+config EXAMPLES_TCPECHO_NOMAC
+	bool "Use Canned MAC Address"
+	default n
+	depends on EXAMPLES_TCPECHO && !NSH_BUILTIN_APPS
+
+config EXAMPLES_TCPECHO_IPADDR
+	hex "Target IP address"
+	default 0x0a000002
+	depends on EXAMPLES_TCPECHO && !NSH_BUILTIN_APPS && !EXAMPLES_TCPECHO_DHCPC
+
+config EXAMPLES_TCPECHO_DRIPADDR
+	hex "Default Router IP address (Gateway)"
+	default 0x0a000001
+	depends on EXAMPLES_TCPECHO && !NSH_BUILTIN_APPS
+
+config EXAMPLES_TCPECHO_NETMASK
+	hex "Network Mask"
+	default 0xffffff00
+	depends on EXAMPLES_TCPECHO && !NSH_BUILTIN_APPS
diff --git a/apps/examples/tcpecho/Makefile b/apps/examples/tcpecho/Makefile
new file mode 100644
index 000000000..7eb59120d
--- /dev/null
+++ b/apps/examples/tcpecho/Makefile
@@ -0,0 +1,110 @@
+############################################################################
+# apps/examples/tcpecho/Makefile
+#
+#   Copyright (C) 2013 Max Holtzberg. All rights reserved.
+#   Copyright (C) 2008, 2010-2012 Gregory Nutt. All rights reserved.
+#
+#   Authors: Max Holtzberg <mh@uvc.de>
+#            Gregory Nutt <gnutt@nuttx.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name NuttX nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+-include $(TOPDIR)/.config
+-include $(TOPDIR)/Make.defs
+include $(APPDIR)/Make.defs
+
+# Discover built-in application info
+
+APPNAME		= tcpecho
+PRIORITY	= SCHED_PRIORITY_DEFAULT
+STACKSIZE	= 2048
+
+ASRCS		=
+CSRCS		= tcpecho_main.c
+
+AOBJS		= $(ASRCS:.S=$(OBJEXT))
+COBJS		= $(CSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS)
+OBJS		= $(AOBJS) $(COBJS)
+
+ifeq ($(CONFIG_WINDOWS_NATIVE),y)
+  BIN		= ..\..\libapps$(LIBEXT)
+else
+ifeq ($(WINTOOL),y)
+  BIN		= ..\\..\\libapps$(LIBEXT)
+else
+  BIN		= ../../libapps$(LIBEXT)
+endif
+endif
+
+ROOTDEPPATH	= --dep-path .
+
+# Common build
+
+VPATH		=
+
+all: .built
+.PHONY: clean depend distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	$(call ARCHIVE, $(BIN), $(OBJS))
+	@touch .built
+
+ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
+$(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat: $(DEPCONFIG) Makefile
+	$(call REGISTER,$(APPNAME),$(PRIORITY),$(STACKSIZE),$(APPNAME)_main)
+
+context: $(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat
+else
+context:
+endif
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	$(call DELFILE, .built)
+	$(call CLEAN)
+
+distclean: clean
+	$(call DELFILE, Make.dep)
+	$(call DELFILE, .depend)
+
+-include Make.dep
diff --git a/apps/examples/tcpecho/tcpecho_main.c b/apps/examples/tcpecho/tcpecho_main.c
new file mode 100644
index 000000000..c26462f14
--- /dev/null
+++ b/apps/examples/tcpecho/tcpecho_main.c
@@ -0,0 +1,387 @@
+/****************************************************************************
+ * examples/tcpecho/tcpecho_main.c
+ *
+ *   Copyright (C) 2013 Max Holtzberg. All rights reserved.
+ *   Copyright (C) 2008, 2011-2012 Gregory Nutt. All rights reserved.
+ *
+ *   Authors: Max Holtzberg <mh@uvc.de>
+ *            Gregory Nutt <gnutt@nuttx.org>
+ *
+ * This code is based upon the poll example from W. Richard Stevens'
+ * UNIX Network Programming Book.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <debug.h>
+#include <errno.h>
+#include <poll.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <net/if.h>
+#include <nuttx/net/uip/uip.h>
+#include <nuttx/net/uip/uip-arp.h>
+
+#include <apps/netutils/uiplib.h>
+
+#ifdef CONFIG_EXAMPLES_TCPECHO_DHCPC
+#  include <arpa/inet.h>
+#endif
+
+/* Here we include the header file for the application(s) we use in
+ * our project as defined in the config/<board-name>/defconfig file
+ */
+
+/* DHCPC may be used in conjunction with any other feature (or not) */
+
+#ifdef CONFIG_EXAMPLES_TCPECHO_DHCPC
+#  include <apps/netutils/resolv.h>
+#  include <apps/netutils/dhcpc.h>
+#endif
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define TCPECHO_MAXLINE 64
+#define TCPECHO_POLLTIMEOUT 10000
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int tcpecho_netsetup(void);
+static int tcpecho_server(void);
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static int tcpecho_netsetup()
+{
+  /* If this task is excecutated as an NSH built-in function, then the
+   * network has already been configured by NSH's start-up logic.
+   */
+
+  struct dhcpc_state ds;
+#ifndef CONFIG_NSH_BUILTIN_APPS
+  struct in_addr addr;
+#if defined(CONFIG_EXAMPLES_TCPECHO_DHCPC) || defined(CONFIG_EXAMPLES_TCPECHO_NOMAC)
+  uint8_t mac[IFHWADDRLEN];
+#endif
+#ifdef CONFIG_EXAMPLES_TCPECHO_DHCPC
+  void *handle;
+#endif
+
+/* Many embedded network interfaces must have a software assigned MAC */
+
+#ifdef CONFIG_EXAMPLES_TCPECHO_NOMAC
+  mac[0] = 0x00;
+  mac[1] = 0xe0;
+  mac[2] = 0xde;
+  mac[3] = 0xad;
+  mac[4] = 0xbe;
+  mac[5] = 0xef;
+  uip_setmacaddr("eth0", mac);
+#endif
+
+  /* Set up our host address */
+
+#ifdef CONFIG_EXAMPLES_TCPECHO_DHCPC
+  addr.s_addr = 0;
+#else
+  addr.s_addr = HTONL(CONFIG_EXAMPLES_TCPECHO_IPADDR);
+#endif
+  uip_sethostaddr("eth0", &addr);
+
+  /* Set up the default router address */
+
+  addr.s_addr = HTONL(CONFIG_EXAMPLES_TCPECHO_DRIPADDR);
+  uip_setdraddr("eth0", &addr);
+
+  /* Setup the subnet mask */
+
+  addr.s_addr = HTONL(CONFIG_EXAMPLES_TCPECHO_NETMASK);
+  uip_setnetmask("eth0", &addr);
+
+#ifdef CONFIG_EXAMPLES_TCPECHO_DHCPC
+  /* Set up the resolver */
+
+  resolv_init();
+
+  /* Get the MAC address of the NIC */
+
+  uip_getmacaddr("eth0", mac);
+
+  /* Set up the DHCPC modules */
+
+  handle = dhcpc_open(&mac, IFHWADDRLEN);
+
+  /* Get an IP address.  Note:  there is no logic here for renewing the address in this
+   * example.  The address should be renewed in ds.lease_time/2 seconds.
+   */
+
+  if (!handle)
+    {
+      return ERROR;
+    }
+
+  if (dhcpc_request(handle, &ds) != OK)
+    {
+      return ERROR;
+    }
+
+  uip_sethostaddr("eth1", &ds.ipaddr);
+
+  if (ds.netmask.s_addr != 0)
+    {
+      uip_setnetmask("eth0", &ds.netmask);
+    }
+
+  if (ds.default_router.s_addr != 0)
+    {
+      uip_setdraddr("eth0", &ds.default_router);
+    }
+
+  if (ds.dnsaddr.s_addr != 0)
+    {
+      resolv_conf(&ds.dnsaddr);
+    }
+
+  dhcpc_close(handle);
+  printf("IP: %s\n", inet_ntoa(ds.ipaddr));
+
+#endif /* CONFIG_EXAMPLES_TCPECHO_DHCPC */
+#endif /* CONFIG_NSH_BUILTIN_APPS */
+
+  return OK;
+}
+
+static int tcpecho_server(void)
+{
+  int i, maxi, listenfd, connfd, sockfd;
+  int nready;
+  int ret;
+  ssize_t n;
+  char buf[TCPECHO_MAXLINE];
+  socklen_t clilen;
+  bool stop = false;
+  struct pollfd client[CONFIG_EXAMPLES_TCPECHO_NCONN];
+  struct sockaddr_in cliaddr, servaddr;
+
+  listenfd = socket(AF_INET, SOCK_STREAM, 0);
+
+  if (listenfd < 0)
+    {
+      perror("ERROR: failed to create socket.\n");
+      return ERROR;
+    }
+
+  bzero(&servaddr, sizeof(servaddr));
+  servaddr.sin_family      = AF_INET;
+  servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
+  servaddr.sin_port        = htons(CONFIG_EXAMPLES_TCPECHO_PORT);
+
+  ret = bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr));
+  if (ret < 0)
+    {
+      perror("ERROR: failed to bind socket.\n");
+      return ERROR;
+    }
+
+  ndbg("start listening on port: %d\n", CONFIG_EXAMPLES_TCPECHO_PORT);
+
+  ret = listen(listenfd, CONFIG_EXAMPLES_TCPECHO_BACKLOG);
+  if (ret < 0)
+    {
+      perror("ERROR: failed to start listening\n");
+      return ERROR;
+    }
+
+  client[0].fd = listenfd;
+  client[0].events = POLLRDNORM;
+  for (i = 1; i < CONFIG_EXAMPLES_TCPECHO_NCONN; i++)
+    {
+      client[i].fd = -1;        /* -1 indicates available entry */
+    }
+
+  maxi = 0;                     /* max index into client[] array */
+
+  while(!stop)
+    {
+      nready = poll(client, maxi+1, TCPECHO_POLLTIMEOUT);
+
+      if (client[0].revents & POLLRDNORM)
+        {
+          /* new client connection */
+
+          clilen = sizeof(cliaddr);
+          connfd = accept(listenfd, (struct sockaddr*)&cliaddr, &clilen);
+
+          ndbg("new client: %s\n", inet_ntoa(cliaddr.sin_addr));
+
+          for (i = 1; i < CONFIG_EXAMPLES_TCPECHO_NCONN; i++)
+            {
+              if (client[i].fd < 0)
+                {
+                  client[i].fd = connfd;  /* save descriptor */
+                  break;
+                }
+            }
+
+          if (i == CONFIG_EXAMPLES_TCPECHO_NCONN)
+            {
+              perror("ERROR: too many clients");
+              return ERROR;
+            }
+
+          client[i].events = POLLRDNORM;
+          if (i > maxi)
+            {
+              maxi = i;    /* max index in client[] array */
+            }
+
+          if (--nready <= 0)
+            {
+              continue;    /* no more readable descriptors */
+            }
+        }
+
+      for (i = 1; i <= maxi; i++)
+        {
+          /* check all clients for data */
+
+          if ((sockfd = client[i].fd) < 0)
+            {
+              continue;
+            }
+
+          if (client[i].revents & (POLLRDNORM | POLLERR))
+            {
+              if ( (n = read(sockfd, buf, TCPECHO_MAXLINE)) < 0)
+                {
+                  if (errno == ECONNRESET)
+                    {
+                      /* connection reset by client */
+
+                      ndbg("client[%d] aborted connection\n", i);
+
+                      close(sockfd);
+                      client[i].fd = -1;
+                    }
+                  else
+                    {
+                      perror("ERROR: readline error\n");
+                      close(sockfd);
+                      client[i].fd = -1;
+                    }
+                }
+              else if (n == 0)
+                {
+                  /* connection closed by client */
+
+                  ndbg("client[%d] closed connection\n", i);
+
+                  close(sockfd);
+                  client[i].fd = -1;
+                }
+              else
+                {
+                  if (strcmp(buf, "exit\r\n") == 0)
+                    {
+                      ndbg("client[%d] closed connection\n", i);
+                      close(sockfd);
+                      client[i].fd = -1;
+                    }
+                  else
+                    {
+                      write(sockfd, buf, n);
+                    }
+                }
+
+              if (--nready <= 0)
+                {
+                  break;  /* no more readable descriptors */
+                }
+            }
+        }
+    }
+
+  for (i = 0; i <= maxi; i++)
+    {
+      if (client[i].fd < 0)
+        {
+          continue;
+        }
+
+      close(client[i].fd);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * discover_main
+ ****************************************************************************/
+
+int tcpecho_main(int argc, char *argv[])
+{
+  int ret;
+
+  ret = tcpecho_netsetup();
+  if (ret != OK)
+    {
+      perror("ERROR: failed to setup network\n");
+      exit(1);
+    }
+
+  printf("Start echo server\n");
+
+  ret = tcpecho_server();
+
+  return ret;
+}
+