Network discover utility from Max Holtzberg

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5137 42af7a65-404d-4744-a932-0658087f49c3

16 files changed, 1041 insertions, 4 deletions

diff --git a/apps/ChangeLog.txt b/apps/ChangeLog.txt
index 833a62cd1..6df66b95f 100755
--- a/apps/ChangeLog.txt
+++ b/apps/ChangeLog.txt
@@ -319,3 +319,7 @@
 	* apps/netutils/webserver/httpd_sendfile.c:  Add and option,
 	  CONFIG_NETUTILS_HTTPD_SENDFILE to transfer files using the NuttX
 	  sendfile() interface.
+	* apps/netutils/discover:  A UDP network discovery utility contributed
+	  by Max Holtzberg.
+	* apps/examples/discover:  A test example for the UDP network discovery
+	  utility (also contribed by Max Holtzberg).
diff --git a/apps/examples/README.txt b/apps/examples/README.txt
index 52d7279da..0d327ebfb 100644
--- a/apps/examples/README.txt
+++ b/apps/examples/README.txt
@@ -275,6 +275,28 @@ examples/dhcpd
 
   CONFIGURED_APPS += uiplib
 
+examples/discover
+^^^^^^^^^^^^^^^^^
+
+  This example execises netutils/discover utility.  This example initializes
+  and starts the UDP discover daemon. This daemon is useful for discovering
+  devices in local networks, especially with DHCP configured devices.  It
+  listens for UDP broadcasts which also can include a device class so that
+  groups of devices can be discovered. It is also possible to address all
+  classes with a kind of broadcast discover.
+
+  This example will automatically be built as an NSH built-in if
+  CONFIG_NSH_BUILTIN_APPS is selected.  Otherwise, it will be a standalone
+  program with entry point "discover_main".
+
+  NuttX configuration settings:
+
+    CONFIG_EXAMPLE_DISCOVER_DHCPC - DHCP Client
+    CONFIG_EXAMPLE_DISCOVER_NOMAC - Use canned MAC address
+    CONFIG_EXAMPLE_DISCOVER_IPADDR - Target IP address
+    CONFIG_EXAMPLE_DISCOVER_DRIPADDR - Router IP address
+    CONFIG_EXAMPLE_DISCOVER_NETMASK - Network Mask
+
 examples/ftpc
 ^^^^^^^^^^^^^
 
diff --git a/apps/examples/discover/Kconfig b/apps/examples/discover/Kconfig
new file mode 100644
index 000000000..afdb9ff82
--- /dev/null
+++ b/apps/examples/discover/Kconfig
@@ -0,0 +1,42 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config EXAMPLES_DISCOVER
+	bool "UDP Discovery Example"
+	default n
+	depends on NET_UDP
+	select NETUTILS_DISCOVER
+	---help---
+		Enable the netutils/discover utility.  This example initializes and
+		starts the UDP discover daemon. This daemon is useful for
+		discovering devices in local networks, especially with DHCP
+		configured devices.  It listens for UDP broadcasts which also can
+		include a device class so that groups of devices can be discovered.
+		It is also possible to address all classes with a kind of broadcast
+		discover.
+
+if EXAMPLES_DISCOVER
+
+config EXAMPLE_DISCOVER_DHCPC
+	bool "DHCP Client"
+	default n
+
+config EXAMPLE_DISCOVER_NOMAC
+	bool "Use canned MAC address"
+	default n
+
+config EXAMPLE_DISCOVER_IPADDR
+	hex "Target IP address"
+	default 0x0a000002
+
+config EXAMPLE_DISCOVER_DRIPADDR
+	hex "Router IP address"
+	default 0x0a000001
+
+config EXAMPLE_DISCOVER_NETMASK
+	hex "Network Mask"
+	default 0xffffff00
+
+endif
diff --git a/apps/examples/discover/Makefile b/apps/examples/discover/Makefile
new file mode 100644
index 000000000..f42f310a1
--- /dev/null
+++ b/apps/examples/discover/Makefile
@@ -0,0 +1,106 @@
+############################################################################
+# apps/examples/discover/Makefile
+#
+#   Copyright (C) 2012 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		= discover
+PRIORITY	= SCHED_PRIORITY_DEFAULT
+STACKSIZE	= 2048
+
+ASRCS		=
+CSRCS		= main.c
+
+AOBJS		= $(ASRCS:.S=$(OBJEXT))
+COBJS		= $(CSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS)
+OBJS		= $(AOBJS) $(COBJS)
+
+ifeq ($(WINTOOL),y)
+  BIN		= "${shell cygpath -w  $(APPDIR)/libapps$(LIBEXT)}"
+else
+  BIN		= "$(APPDIR)/libapps$(LIBEXT)"
+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)
+	@( for obj in $(OBJS) ; do \
+		$(call ARCHIVE, $(BIN), $${obj}); \
+	done ; )
+	@touch .built
+
+.context:
+ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
+	$(call REGISTER,$(APPNAME),$(PRIORITY),$(STACKSIZE),$(APPNAME)_main)
+	@touch $@
+endif
+
+context: .context
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	@rm -f *.o *~ .*.swp .built
+	$(call CLEAN)
+
+distclean: clean
+	@rm -f Make.dep .depend
+
+-include Make.dep
diff --git a/apps/examples/discover/main.c b/apps/examples/discover/main.c
new file mode 100644
index 000000000..b857e4f68
--- /dev/null
+++ b/apps/examples/discover/main.c
@@ -0,0 +1,183 @@
+/****************************************************************************
+ * examples/discover/main.c
+ *
+ *   Copyright (C) 2012 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>
+ *
+ * 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 <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <debug.h>
+
+#include <net/if.h>
+#include <nuttx/net/uip/uip.h>
+#include <nuttx/net/uip/uip-arp.h>
+
+#include <apps/netutils/uiplib.h>
+#include <apps/netutils/discover.h>
+
+#ifdef CONFIG_EXAMPLE_DISCOVER_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_EXAMPLE_DISCOVER_DHCPC
+#  include <apps/netutils/resolv.h>
+#  include <apps/netutils/dhcpc.h>
+#endif
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * discover_main
+ ****************************************************************************/
+
+int discover_main(int argc, char *argv[])
+{
+#ifndef CONFIG_NSH_BUILTIN_APPS
+  struct in_addr addr;
+#if defined(CONFIG_EXAMPLE_DISCOVER_DHCPC) || defined(CONFIG_EXAMPLE_DISCOVER_NOMAC)
+  uint8_t mac[IFHWADDRLEN];
+#endif
+#ifdef CONFIG_EXAMPLE_DISCOVER_DHCPC
+  void *handle;
+#endif
+
+/* Many embedded network interfaces must have a software assigned MAC */
+
+#ifdef CONFIG_EXAMPLE_DISCOVER_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_EXAMPLE_DISCOVER_DHCPC
+  addr.s_addr = 0;
+#else
+  addr.s_addr = HTONL(CONFIG_EXAMPLE_DISCOVER_IPADDR);
+#endif
+  uip_sethostaddr("eth0", &addr);
+
+  /* Set up the default router address */
+
+  addr.s_addr = HTONL(CONFIG_EXAMPLE_DISCOVER_DRIPADDR);
+  uip_setdraddr("eth0", &addr);
+
+  /* Setup the subnet mask */
+
+  addr.s_addr = HTONL(CONFIG_EXAMPLE_DISCOVER_NETMASK);
+  uip_setnetmask("eth0", &addr);
+
+#ifdef CONFIG_EXAMPLE_DISCOVER_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.
+   */
+
+  printf("Getting IP address\n");
+  if (handle)
+    {
+        struct dhcpc_state ds;
+        (void)dhcpc_request(handle, &ds);
+        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
+#endif /* CONFIG_NSH_BUILTIN_APPS */
+
+  if (discover_start() < 0)
+    {
+      ndbg("Could not start discover daemon.\n");
+      return ERROR;
+    }
+
+  return OK;
+}
+
diff --git a/apps/include/netutils/discover.h b/apps/include/netutils/discover.h
new file mode 100644
index 000000000..c2226918d
--- /dev/null
+++ b/apps/include/netutils/discover.h
@@ -0,0 +1,58 @@
+/****************************************************************************
+ * apps/include/netutils/discover.h
+ *
+ *   Copyright (C) 2012 Max Holtzberg. All rights reserved.
+ *   Author: Max Holtzberg <mh@uvc.de>
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_INCLUDE_NETUTILS_DISCOVER_H
+#define __APPS_INCLUDE_NETUTILS_DISCOVER_H
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: discover_start
+ *
+ * Description:
+ *   Start the discover daemon.
+ *
+ * Return:
+ *   The process ID (pid) of the new discover daemon is returned on
+ *   success; A negated errno is returned if the daemon was not successfully
+ *   started.
+ *
+ ****************************************************************************/
+
+int discover_start(void);
+
+#endif /* __APPS_INCLUDE_NETUTILS_DISCOVER_H */
diff --git a/apps/netutils/Kconfig b/apps/netutils/Kconfig
index cd0cb84dd..aa0f14963 100644
--- a/apps/netutils/Kconfig
+++ b/apps/netutils/Kconfig
@@ -52,3 +52,7 @@ endmenu
 menu "uIP web server"
 source "$APPSDIR/netutils/webserver/Kconfig"
 endmenu
+
+menu "UDP Discovery Utility"
+source "$APPSDIR/netutils/discover/Kconfig"
+endmenu
diff --git a/apps/netutils/Make.defs b/apps/netutils/Make.defs
index 04accf5d2..f957009b5 100644
--- a/apps/netutils/Make.defs
+++ b/apps/netutils/Make.defs
@@ -78,6 +78,10 @@ ifeq ($(CONFIG_NETUTILS_WEBCLIENT),y)
 CONFIGURED_APPS += netutils/webclient
 endif
 
-ifeq ($(CONFIGNETUTILS_WEBSERVER),y)
+ifeq ($(CONFIG_NETUTILS_WEBSERVER),y)
 CONFIGURED_APPS += netutils/webserver
 endif
+
+ifeq ($(CONFIG_NETUTILS_DISCOVER),y)
+CONFIGURED_APPS += netutils/discover
+endif
diff --git a/apps/netutils/Makefile b/apps/netutils/Makefile
index 1313c223d..03261c7a3 100644
--- a/apps/netutils/Makefile
+++ b/apps/netutils/Makefile
@@ -38,7 +38,8 @@
 # Sub-directories
 
 ifeq ($(CONFIG_NET),y)
-SUBDIRS = uiplib dhcpc dhcpd ftpc ftpd resolv smtp telnetd webclient webserver tftpc thttpd
+SUBDIRS  = uiplib dhcpc dhcpd discover ftpc ftpd resolv smtp telnetd
+SUBDIRS += webclient webserver tftpc thttpd
 endif
 
 all: nothing
diff --git a/apps/netutils/README.txt b/apps/netutils/README.txt
index 26f11b7ce..231cf62c1 100644
--- a/apps/netutils/README.txt
+++ b/apps/netutils/README.txt
@@ -1,5 +1,5 @@
-netutils
-^^^^^^^^
+netutils README.txt
+^^^^^^^^^^^^^^^^^^^
 
 Contents
 --------
@@ -39,6 +39,12 @@ highly influenced by uIP) include:
 
   dhcpd     - Dynamic Host Configuration Protocol (DHCP) server.  See
               apps/include/netutils/dhcpd.h for interface information.
+  discover  - This daemon is useful for discovering devices in local
+              networks, especially with DHCP configured devices.  It
+              listens for UDP broadcasts which also can include a
+              device class so that groups of devices can be discovered.
+              It is also possible to address all classes with a kind of
+              broadcast discover. (Contributed by Max Holtzberg).
   tftpc     - TFTP client.  See apps/include/netutils/tftp.h
               for interface information.
   telnetd   - TELNET server.  This is the Telnet logic adapted from
diff --git a/apps/netutils/discover/Kconfig b/apps/netutils/discover/Kconfig
new file mode 100644
index 000000000..336550511
--- /dev/null
+++ b/apps/netutils/discover/Kconfig
@@ -0,0 +1,39 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config NETUTILS_DISCOVER
+	bool "Network Discovery Utility"
+	default n
+	depends on NET_UDP
+	---help---
+		Tool for discovering devices on the local network per UDP broadcast.
+
+if NETUTILS_DISCOVER
+
+DISCOVER_STACK_SIZE
+	int "Discover Daemon Stack Size"
+	default 1024
+
+DISCOVER_PRIORITY
+	int "Discover Daemon Priority"
+	default 50
+
+DISCOVER_PORT
+	int "Discover Daemon Port Number"
+	default 96
+
+DISCOVER_INTERFACE
+	int "Network Interface Name"
+	default "eth0"
+
+DISCOVER_DEVICE_CLASS
+	hex "Network Discovery Class"
+	default 0xff
+
+CONFIG_DISCOVER_DESCR
+	string "Discoverer Description"
+	default "NuttX"
+
+endif
diff --git a/apps/netutils/discover/Makefile b/apps/netutils/discover/Makefile
new file mode 100644
index 000000000..52099b439
--- /dev/null
+++ b/apps/netutils/discover/Makefile
@@ -0,0 +1,100 @@
+############################################################################
+# apps/netutils/discover/Makefile
+#
+#   Copyright (C) 2012 Max Holtzberg. All rights reserved.
+#   Copyright (C) 2011-2012 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 $(APPDIR)/Make.defs
+
+# Telnet daemon
+
+ASRCS		=
+CSRCS		= 
+
+ifeq ($(CONFIG_NET_UDP),y)
+CSRCS		+= discover.c
+endif
+
+AOBJS		= $(ASRCS:.S=$(OBJEXT))
+COBJS		= $(CSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS)
+OBJS		= $(AOBJS) $(COBJS)
+
+ifeq ($(WINTOOL),y)
+  BIN		= "${shell cygpath -w  $(APPDIR)/libapps$(LIBEXT)}"
+else
+  BIN		= "$(APPDIR)/libapps$(LIBEXT)"
+endif
+
+ROOTDEPPATH	= --dep-path .
+
+# Common build
+
+VPATH		= 
+
+all: .built
+.PHONY: context depend clean distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	@( for obj in $(OBJS) ; do \
+		$(call ARCHIVE, $(BIN), $${obj}); \
+	done ; )
+	@touch .built
+
+context:
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	@rm -f *.o *~ .*.swp .built
+	$(call CLEAN)
+
+distclean: clean
+	@rm -f Make.dep .depend
+
+-include Make.dep
diff --git a/apps/netutils/discover/README.txt b/apps/netutils/discover/README.txt
new file mode 100644
index 000000000..11aab8bf3
--- /dev/null
+++ b/apps/netutils/discover/README.txt
@@ -0,0 +1,9 @@
+apps/netutils/discover README.txt
+=================================
+
+This daemon is useful for discovering devices in local networks, especially
+with DHCP configured devices.  It listens for UDP broadcasts which also can
+include a device class so that groups of devices can be discovered. It is
+also possible to address all classes with a kind of broadcast discover.
+
+See nuttx/tools/discover.py for a client example.
diff --git a/apps/netutils/discover/discover.c b/apps/netutils/discover/discover.c
new file mode 100644
index 000000000..67df02b3f
--- /dev/null
+++ b/apps/netutils/discover/discover.c
@@ -0,0 +1,456 @@
+/****************************************************************************
+ * examples/discover/main.c
+ *
+ *   Copyright (C) 2012 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 derived from the netutils/dhcpd code.
+ *
+ * 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 <sched.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <apps/netutils/discover.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_DISCOVER_STACK_SIZE
+#  define CONFIG_DISCOVER_STACK_SIZE 1024
+#endif
+
+#ifndef CONFIG_DISCOVER_PRIORITY
+#  define CONFIG_DISCOVER_PRIORITY SCHED_PRIORITY_DEFAULT
+#endif
+
+#ifndef CONFIG_DISCOVER_PORT
+#  define CONFIG_DISCOVER_PORT 96
+#endif
+
+#ifndef CONFIG_DISCOVER_INTERFACE
+#  define CONFIG_DISCOVER_INTERFACE "eth0"
+#endif
+
+#ifndef CONFIG_DISCOVER_DEVICE_CLASS
+#  define CONFIG_DISCOVER_DEVICE_CLASS DISCOVER_ALL
+#endif
+
+#ifndef CONFIG_DISCOVER_DESCR
+#  define CONFIG_DISCOVER_DESCR CONFIG_ARCH_BOARD
+#endif
+
+/* Internal Definitions *****************************************************/
+/* Discover request packet format:
+ * Byte Description
+ * 0    Protocol indentifier (0x99)
+ * 1    Request command 0x01
+ * 2    Destination device class (For querying subsets of available devices) 
+ *      0xff for all devices
+ * 3    Checksum (Byte 0 - Byte 1 - Byte n) & 0xff
+ */
+
+/* Discover response packet format:
+ * Byte Description
+ * 0    Protocol indentifier (0x99)
+ * 1    Reponse command (0x02)
+ * 2-33 Device description string with 0 bytes filled    
+ * 34   Checksum (Byte 0 - Byte 1 - Byte n) & 0xff
+ */
+
+#define DISCOVER_PROTO_ID 0x99
+#define DISCOVER_REQUEST 0x01
+#define DISCOVER_RESPONSE 0x02
+#define DISCOVER_ALL 0xff
+#define DISCOVER_REQUEST_SIZE 4
+#define DISCOVER_RESPONSE_SIZE 35
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+typedef uint8_t request_t[DISCOVER_REQUEST_SIZE];
+typedef uint8_t response_t[DISCOVER_RESPONSE_SIZE];
+
+struct discover_state_s
+{
+  in_addr_t serverip;
+  request_t request;
+  response_t response;
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+struct discover_state_s g_state;
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int discover_daemon(int argc, char *argv[]);
+static inline int discover_socket(void);
+static inline int discover_openlistener(void);
+static inline int discover_openresponder(void);
+static inline int discover_parse(request_t packet);
+static inline int discover_respond(in_addr_t *ipaddr);
+static inline void discover_initresponse(void);
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static inline void discover_initresponse()
+{
+  int chk = 0;
+  int i;
+
+  g_state.response[0] = DISCOVER_PROTO_ID;
+  g_state.response[1] = DISCOVER_RESPONSE;
+
+  strncpy((char*) &g_state.response[2], CONFIG_DISCOVER_DESCR,
+          DISCOVER_RESPONSE_SIZE-3);
+
+  for (i = 0; i < DISCOVER_RESPONSE_SIZE-1; i++)
+    {
+      chk -= g_state.response[i];
+    }
+
+  /* Append check sum */
+
+  g_state.response[DISCOVER_RESPONSE_SIZE-1] = chk & 0xff;
+}
+
+static int discover_daemon(int argc, char *argv[])
+{
+  int sockfd = -1;
+  int nbytes;
+  int addrlen = sizeof(struct sockaddr_in);
+  struct sockaddr_in srcaddr; 
+
+  memset(&g_state, 0, sizeof(struct discover_state_s));
+  discover_initresponse();
+
+  nvdbg("Started\n");
+
+  for (;;)
+    {
+      /* Create a socket to listen for requests from DHCP clients */
+
+      if (sockfd < 0)
+        {
+          sockfd = discover_openlistener();
+          if (sockfd < 0)
+            {
+                ndbg("Failed to create socket\n");
+                break;
+            }
+        }
+
+      /* Read the next packet */
+      
+      nbytes = recvfrom(sockfd, &g_state.request, sizeof(g_state.request), 0,
+                        (struct sockaddr*) &srcaddr,
+                        (socklen_t *) &addrlen);
+      if (nbytes < 0)
+        {
+          /* On errors (other EINTR), close the socket and try again */
+
+          ndbg("recv failed: %d\n", errno);
+          if (errno != EINTR)
+            {
+              close(sockfd);
+              sockfd = -1;
+            }
+          continue;
+        }
+      
+      if (discover_parse(g_state.request) != OK)
+        {
+          continue;
+        }
+      
+      ndbg("Received discover from %08lx'\n", srcaddr.sin_addr.s_addr);
+      
+      discover_respond(&srcaddr.sin_addr.s_addr);
+    }
+
+  return OK;
+}
+
+static inline int discover_parse(request_t packet)
+{
+  int i;
+  uint8_t chk = 0;
+
+  if (packet[0] != DISCOVER_PROTO_ID)
+    {
+      ndbg("Wrong protocol id: %d\n", packet[0]);
+      return ERROR;
+    }
+
+  if (packet[1] != DISCOVER_REQUEST)
+    {
+      ndbg("Wrong command: %d\n", packet[1]);
+      return ERROR;
+    }
+     
+  if (packet[2] == 0xff || packet[2] == CONFIG_DISCOVER_DEVICE_CLASS)
+    {
+      for (i = 0; i < DISCOVER_REQUEST_SIZE-1; i++)
+        chk -= packet[i];
+
+      if ((chk & 0xff) != packet[3])
+        {
+          ndbg("Checksum does not match: %d\n", packet[3]);
+          return ERROR;
+        }
+      else
+        {
+          return OK;
+        }
+    }
+  return ERROR;
+}
+
+static inline int discover_respond(in_addr_t *ipaddr)
+{
+  struct sockaddr_in addr;
+  int sockfd;
+  int ret;
+
+  sockfd = discover_openresponder();
+  if (sockfd >= 0)
+    {
+      /* Then send the reponse to the DHCP client port at that address */
+
+      memset(&addr, 0, sizeof(struct sockaddr_in));
+      addr.sin_family      = AF_INET;
+      addr.sin_port        = HTONS(CONFIG_DISCOVER_PORT);
+      addr.sin_addr.s_addr = *ipaddr;
+
+      ret = sendto(sockfd, &g_state.response, sizeof(g_state.response), 0,
+                   (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
+      if (ret < 0)
+        {
+          ndbg("Could not send discovery response: %d\n", errno);
+        }
+
+      close(sockfd);
+    }
+
+  return ret;
+}
+
+static inline int discover_socket()
+{
+  int sockfd;
+#if defined(HAVE_SO_REUSEADDR) || defined(HAVE_SO_BROADCAST)
+  int optval;
+  int ret;
+#endif
+
+  /* Create a socket to listen for requests from DHCP clients */
+
+  sockfd = socket(PF_INET, SOCK_DGRAM, 0);
+  if (sockfd < 0)
+    {
+      ndbg("socket failed: %d\n", errno);
+      return ERROR;
+    }
+
+  /* Configure the socket */
+
+#ifdef HAVE_SO_REUSEADDR
+  optval = 1;
+  ret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (void*)&optval, sizeof(int));
+  if (ret < 0)
+    {
+      ndbg("setsockopt SO_REUSEADDR failed: %d\n", errno);
+      close(sockfd);
+      return ERROR;
+    }
+#endif
+
+#ifdef HAVE_SO_BROADCAST
+  optval = 1;
+  ret = setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, (void*)&optval, sizeof(int));
+  if (ret < 0)
+    {
+      ndbg("setsockopt SO_BROADCAST failed: %d\n", errno);
+      close(sockfd);
+      return ERROR;
+    }
+#endif
+
+  return sockfd;
+}
+
+static inline int discover_openlistener()
+{
+  struct sockaddr_in addr;
+  struct ifreq req;
+  int sockfd;
+  int ret;
+
+  /* Create a socket to listen for requests from DHCP clients */
+
+  sockfd = discover_socket();
+  if (sockfd < 0)
+    {
+      ndbg("socket failed: %d\n", errno);
+      return ERROR;
+    }
+
+  /* Get the IP address of the selected device */
+
+  strncpy(req.ifr_name, CONFIG_DISCOVER_INTERFACE, IFNAMSIZ);
+  ret = ioctl(sockfd, SIOCGIFADDR, (unsigned long)&req);
+  if (ret < 0)
+    {
+      ndbg("setsockopt SIOCGIFADDR failed: %d\n", errno);
+      close(sockfd);
+      return ERROR;
+    }
+  g_state.serverip = ((struct sockaddr_in*)&req.ifr_addr)->sin_addr.s_addr;
+  nvdbg("serverip: %08lx\n", ntohl(g_state.serverip));
+
+  /* Bind the socket to a local port. We have to bind to INADDRY_ANY to
+   * receive broadcast messages.
+   */
+
+  addr.sin_family      = AF_INET;
+  addr.sin_port        = htons(CONFIG_DISCOVER_PORT);
+  addr.sin_addr.s_addr = INADDR_ANY;
+
+  ret = bind(sockfd, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
+  if (ret < 0)
+   {
+     ndbg("bind failed, port=%d addr=%08lx: %d\n",
+           addr.sin_port, (long)addr.sin_addr.s_addr, errno);
+     close(sockfd);
+     return ERROR;
+   }
+
+  return sockfd;
+}
+
+static inline int discover_openresponder(void)
+{
+  struct sockaddr_in addr;
+  int sockfd;
+  int ret;
+
+  /* Create a socket for responding to discovery message */
+
+  sockfd = discover_socket();
+  if (sockfd < 0)
+    {
+      ndbg("socket failed: %d\n", errno);
+      return ERROR;
+    }
+
+  /* Bind the socket to a local port.*/
+
+  addr.sin_family      = AF_INET;
+  addr.sin_port        = 0;
+  addr.sin_addr.s_addr = g_state.serverip;
+
+  ret = bind(sockfd, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
+  if (ret < 0)
+   {
+     ndbg("bind failed, port=%d addr=%08lx: %d\n",
+           addr.sin_port, (long)addr.sin_addr.s_addr, errno);
+     close(sockfd);
+     return ERROR;
+   }
+
+  return sockfd;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: discover_start
+ *
+ * Description:
+ *   Start the discover daemon.
+ *
+ * Return:
+ *   The process ID (pid) of the new discover daemon is returned on
+ *   success; A negated errno is returned if the daemon was not successfully
+ *   started.
+ *
+ ****************************************************************************/
+
+int discover_start()
+{
+  pid_t pid;
+
+  /* Then start the new daemon */
+
+  pid = TASK_CREATE("Discover daemon", CONFIG_DISCOVER_PRIORITY,
+                    CONFIG_DISCOVER_STACK_SIZE, discover_daemon, NULL);
+  if (pid < 0)
+    {
+      int errval = errno;
+      ndbg("Failed to start the discover daemon: %d\n", errval);
+      return -errval;
+    }
+
+  /* Return success */
+
+  return pid;
+}
diff --git a/nuttx/Documentation/README.html b/nuttx/Documentation/README.html
index 135c4f359..5bc3d1d96 100644
--- a/nuttx/Documentation/README.html
+++ b/nuttx/Documentation/README.html
@@ -254,6 +254,7 @@
      |- modbus/
      |   `- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/apps/modbus/README.txt?view=log"><b><i>README.txt</i></b></a>
      |- netutils/
+     |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/apps/netutils/discover/README.txt?view=log">discover/README.txt</a>
      |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/apps/netutils/ftpc/README.txt?view=log">ftpc/README.txt</a>
      |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/apps/netutils/telnetd/README.txt?view=log">telnetd/README.txt</a>
      |   `- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/apps/netutils/README?view=log"><b><i>README</i></b></a>
diff --git a/nuttx/README.txt b/nuttx/README.txt
index b0aa5384c..ae33a6e9c 100644
--- a/nuttx/README.txt
+++ b/nuttx/README.txt
@@ -824,6 +824,8 @@ apps
  |- modbus/
  |   `- README.txt
  |- netutils/
+ |   |- discover
+ |   |  `- README.txt
  |   |- ftpc
  |   |  `- README.txt
  |   |- telnetd