examples/bridge/bridge_main.c - nuttx-apps - Git at Google

 /****************************************************************************
  * apps/examples/bridge/bridge_main.c
  *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.  The
  * ASF licenses this file to you 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.
  *
  ****************************************************************************/

 /****************************************************************************
  * Included Files
  ****************************************************************************/

 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sched.h>
 #include <errno.h>
 #include <debug.h>
 #include <unistd.h>

 #include <net/if.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>

 #include "netutils/netlib.h"

 #if defined(CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC) || \
     defined(CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC)
 #  include "netutils/dhcpc.h"
 #endif

 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/

 /****************************************************************************
  * Private Data
  ****************************************************************************/

 static in_addr_t g_net1_ipaddr;
 static in_addr_t g_net2_ipaddr;
 static uint8_t g_net1_buffer[CONFIG_EXAMPLES_BRIDGE_NET1_IOBUFIZE];
 static uint8_t g_net2_buffer[CONFIG_EXAMPLES_BRIDGE_NET2_IOBUFIZE];

 /****************************************************************************
  * Private Functions
  ****************************************************************************/

 /****************************************************************************
  * Name: briget_net1_setup
  ****************************************************************************/

 static int briget_net1_setup(void)
 {
   /* If this task is executed as an NSH built-in function, then the
    * network has already been configured by NSH's start-up logic.
    */

 #ifndef CONFIG_NSH_NETINIT
   struct in_addr addr;
 #if defined(CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC) || \
     defined(CONFIG_EXAMPLES_BRIDGE_NET1_NOMAC)
   uint8_t mac[IFHWADDRLEN];
 #endif
 #ifdef CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC
   struct dhcpc_state ds;
   void *handle;
   char inetaddr[INET_ADDRSTRLEN];
 #endif

   printf("NET1: Configuring %s\n", CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME);

   /* Many embedded network interfaces must have a software assigned MAC */

 #ifdef CONFIG_EXAMPLES_BRIDGE_NET1_NOMAC
   mac[0] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 5)) & 0xff;
   mac[1] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 4)) & 0xff;
   mac[2] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 3)) & 0xff;
   mac[3] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 2)) & 0xff;
   mac[4] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 1)) & 0xff;
   mac[5] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 0)) & 0xff;
   netlib_setmacaddr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, mac);
 #endif

   /* Set up our host address */

 #ifdef CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC
   addr.s_addr = 0;
 #else
   addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_IPADDR);
 #endif
   netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &addr);

   /* Set up the default router address */

   addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_DRIPADDR);
   netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &addr);

   /* Setup the subnet mask */

   addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_NETMASK);
   netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &addr);

   /* New versions of netlib_set_ipvXaddr will not bring the network up,
    * So ensure the network is really up at this point.
    */

   netlib_ifup("eth0");

 #ifdef CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC
   /* Get the MAC address of the NIC */

   netlib_getmacaddr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, mac);

   /* Set up the DHCPC modules */

   handle = dhcpc_open("eth0", &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)
     {
       fprintf(stderr, "NET1 ERROR: dhcpc_open failed\n");
       return ERROR;
     }

   if (dhcpc_request(handle, &ds) != OK)
     {
       fprintf(stderr, "NET1 ERROR: dhcpc_request failed\n");
       return ERROR;
     }

   netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &ds.ipaddr);

   if (ds.netmask.s_addr != 0)
     {
       netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME,
                              &ds.netmask);
     }

   if (ds.default_router.s_addr != 0)
     {
       netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME,
                             &ds.default_router);
     }

   if (ds.dnsaddr.s_addr != 0)
     {
       netlib_set_ipv4dnsaddr(&ds.dnsaddr);
     }

   dhcpc_close(handle);
   printf("NET1: Assigned IP: %s\n",
          net_ntoa_r(ds.ipaddr, inetaddr, sizeof(inetaddr)));

   /* Save the IP address in network order */

   g_net1_ipaddr = ds.ipaddr;

 #else
   /* Save the IP address in network order */

   g_net1_ipaddr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_IPADDR);

 #endif /* CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC */

 #else /* CONFIG_NSH_NETINIT */
   /* Hmmm.. there is an issue here.  Where do we get the IP address if we
    * are a builtin in application?
    */
 #  warning Missing logic

 #endif /* CONFIG_NSH_NETINIT */

   return OK;
 }

 /****************************************************************************
  * Name: briget_net2_setup
  ****************************************************************************/

 static int briget_net2_setup(void)
 {
   /* If this task is executed as an NSH built-in function, then the
    * network has already been configured by NSH's start-up logic.
    */

 #ifndef CONFIG_NSH_NETINIT
   struct in_addr addr;
 #if defined(CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC) || \
     defined(CONFIG_EXAMPLES_BRIDGE_NET2_NOMAC)
   uint8_t mac[IFHWADDRLEN];
 #endif
 #ifdef CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC
   struct dhcpc_state ds;
   void *handle;
   char inetaddr[INET_ADDRSTRLEN];
 #endif

   printf("NET2: Configuring %s\n", CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME);

   /* Many embedded network interfaces must have a software assigned MAC */

 #ifdef CONFIG_EXAMPLES_BRIDGE_NET2_NOMAC
   mac[0] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 5)) & 0xff;
   mac[1] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 4)) & 0xff;
   mac[2] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 3)) & 0xff;
   mac[3] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 2)) & 0xff;
   mac[4] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 1)) & 0xff;
   mac[5] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 0)) & 0xff;
   netlib_setmacaddr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, mac);
 #endif

   /* Set up our host address */

 #ifdef CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC
   addr.s_addr = 0;
 #else
   addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_IPADDR);
 #endif
   netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &addr);

   /* Set up the default router address */

   addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_DRIPADDR);
   netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &addr);

   /* Setup the subnet mask */

   addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_NETMASK);
   netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &addr);

 #ifdef CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC
   /* Get the MAC address of the NIC */

   netlib_getmacaddr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, 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)
     {
       fprintf(stderr, "NET2 ERROR: dhcpc_open failed\n");
       return ERROR;
     }

   if (dhcpc_request(handle, &ds) != OK)
     {
       fprintf(stderr, "NET2 ERROR: dhcpc_request failed\n");
       return ERROR;
     }

   netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &ds.ipaddr);

   if (ds.netmask.s_addr != 0)
     {
       netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME,
                              &ds.netmask);
     }

   if (ds.default_router.s_addr != 0)
     {
       netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME,
                             &ds.default_router);
     }

   if (ds.dnsaddr.s_addr != 0)
     {
       netlib_set_ipv4dnsaddr(&ds.dnsaddr);
     }

   dhcpc_close(handle);
   printf("NET1: Assigned IP: %s\n",
          inet_ntoa_r(ds.ipaddr, inetaddr, sizeof(inetaddr)));

   /* Save the IP address in network order */

   g_net2_ipaddr = ds.ipaddr;

 #else
   /* Save the IP address in network order */

   g_net2_ipaddr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_IPADDR);

 #endif /* CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC */

 #else /* CONFIG_NSH_NETINIT */
   /* Hmmm.. there is an issue here.  Where do we get the IP address if we
    * are a builtin in application?
    */
 #  warning Missing logic

 #endif /* CONFIG_NSH_NETINIT */

   return OK;
 }

 /****************************************************************************
  * Name: bridge_net1_worker
  ****************************************************************************/

 static int bridge_net1_worker(int argc, char *argv[])
 {
   struct sockaddr_in receiver;
   struct sockaddr_in sender;
   struct sockaddr_in fromaddr;
   struct sockaddr_in toaddr;
   socklen_t addrlen;
   in_addr_t tmpaddr;
   ssize_t nrecvd;
   ssize_t nsent;
   int optval;
   int recvsd;
   int sndsd;

   printf("NET1: Worker started.  PID=%d\n", getpid());

   /* Create a UDP receive socket on network 1 */

   tmpaddr = ntohl(g_net1_ipaddr);
   printf("NET1: Create receive socket: %d.%d.%d.%d:%d\n",
          (int)(tmpaddr >> 24),
          (int)((tmpaddr >> 16) & 0xff),
          (int)((tmpaddr >> 8) & 0xff),
          (int)(tmpaddr & 0xff),
          CONFIG_EXAMPLES_BRIDGE_NET1_RECVPORT);

   recvsd = socket(PF_INET, SOCK_DGRAM, 0);
   if (recvsd < 0)
     {
       fprintf(stderr, "NET1 ERROR: Failed to create receive socket: %d\n",
               errno);
       return EXIT_FAILURE;
     }

   /* Set socket to reuse address */

   optval = 1;
   if (setsockopt(recvsd, SOL_SOCKET, SO_REUSEADDR,
                  &optval, sizeof(int)) < 0)
     {
       fprintf(stderr, "NET1 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
               errno);
       goto errout_with_recvsd;
     }

   /* Bind the socket to a local address */

   receiver.sin_family      = AF_INET;
   receiver.sin_port        = HTONS(CONFIG_EXAMPLES_BRIDGE_NET1_RECVPORT);
   receiver.sin_addr.s_addr = g_net1_ipaddr;

   if (bind(recvsd, (struct sockaddr *)&receiver,
            sizeof(struct sockaddr_in)) < 0)
     {
       fprintf(stderr, "NET1 ERROR: bind failure: %d\n", errno);
       goto errout_with_recvsd;
     }

   /* Create a UDP send socket on network 2 */

   tmpaddr = ntohl(g_net2_ipaddr);
   printf("NET1: Create send socket: %d.%d.%d.%d:INPORT_ANY\n",
          (int)(tmpaddr >> 24),
          (int)((tmpaddr >> 16) & 0xff),
          (int)((tmpaddr >> 8) & 0xff),
          (int)(tmpaddr & 0xff));

   sndsd = socket(PF_INET, SOCK_DGRAM, 0);
   if (sndsd < 0)
     {
       fprintf(stderr, "NET1 ERROR: Failed to create send socket: %d\n",
               errno);
       goto errout_with_recvsd;
     }

   /* Set socket to reuse address */

   optval = 1;
   if (setsockopt(sndsd, SOL_SOCKET, SO_REUSEADDR,
                  &optval, sizeof(int)) < 0)
     {
       fprintf(stderr, "NET1 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
               errno);
       goto errout_with_sendsd;
     }

   /* Bind the socket to a local address */

   sender.sin_family      = AF_INET;
   sender.sin_port        = 0;
   sender.sin_addr.s_addr = g_net2_ipaddr;

   if (bind(sndsd, (struct sockaddr *)&sender,
            sizeof(struct sockaddr_in)) < 0)
     {
       printf("NET1: bind failure: %d\n", errno);
       goto errout_with_sendsd;
     }

   /* Then receive and forward UDP packets forever  */

   for (; ; )
     {
       /* Read a packet on network 1 */

       printf("NET1: Receiving up to %d bytes on network 1\n",
              CONFIG_EXAMPLES_BRIDGE_NET1_IOBUFIZE);

       addrlen = sizeof(struct sockaddr_in);
       nrecvd = recvfrom(recvsd, g_net1_buffer,
                         CONFIG_EXAMPLES_BRIDGE_NET1_IOBUFIZE, 0,
                         (FAR struct sockaddr *)&fromaddr, &addrlen);

       tmpaddr = ntohl(fromaddr.sin_addr.s_addr);
       printf("NET1: Received %ld bytes from %d.%d.%d.%d:%d\n",
              (long)nrecvd,
              (int)(tmpaddr >> 24),
              (int)((tmpaddr >> 16) & 0xff),
              (int)((tmpaddr >> 8) & 0xff),
              (int)(tmpaddr & 0xff),
              ntohs(fromaddr.sin_port));

       /* Check for a receive error or zero bytes received.  The negative
        * return value indicates a receive error; Zero would mean that the
        * other side of the "connection" performed an "orderly" shutdown.
        * This should not occur with a UDP socket and so must also be an
        * error of some kind.
        */

       if (nrecvd <= 0)
         {
           if (nrecvd < 0)
             {
               fprintf(stderr, "NET1 ERROR: recvfrom failed: %d\n", errno);
             }
           else
             {
               fprintf(stderr, "NET1 ERROR: recvfrom returned zero\n");
             }

           goto errout_with_sendsd;
         }

       /* Send the newly received packet out network 2 */

       printf("NET1: Sending %ld bytes on network 2: %d.%d.%d.%d:%d\n",
              (long)nrecvd,
              CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST >> 24,
              (CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST >> 16) & 0xff,
              (CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST >> 8) & 0xff,
              CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST & 0xff,
              CONFIG_EXAMPLES_BRIDGE_NET2_HOSTPORT);

       toaddr.sin_family      = AF_INET;
       toaddr.sin_port        = htons(CONFIG_EXAMPLES_BRIDGE_NET2_HOSTPORT);
       toaddr.sin_addr.s_addr = htonl(CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST);

       nsent = sendto(sndsd, g_net1_buffer, nrecvd, 0,
                      (struct sockaddr *)&toaddr,
                      sizeof(struct sockaddr_in));

       /* Check for send errors */

       if (nsent < 0)
         {
           fprintf(stderr, "NET1 ERROR: sendto failed: %d\n", errno);
           goto errout_with_sendsd;
         }
       else if (nsent != nrecvd)
         {
           fprintf(stderr, "NET1 ERROR: Bad send length: %ld Expected: %ld\n",
                   (long)nsent, (long)nrecvd);
           goto errout_with_sendsd;
         }
     }

   close(recvsd);
   close(recvsd);
   return EXIT_SUCCESS;

 errout_with_sendsd:
   close(sndsd);
 errout_with_recvsd:
   close(recvsd);
   return EXIT_FAILURE;
 }

 /****************************************************************************
  * Name: bridge_net2_worker
  ****************************************************************************/

 static int bridge_net2_worker(int argc, char *argv[])
 {
   struct sockaddr_in receiver;
   struct sockaddr_in sender;
   struct sockaddr_in fromaddr;
   struct sockaddr_in toaddr;
   socklen_t addrlen;
   in_addr_t tmpaddr;
   ssize_t nrecvd;
   ssize_t nsent;
   int optval;
   int recvsd;
   int sndsd;

   printf("NET2: Worker started.  PID=%d\n", getpid());

   /* Create a UDP receive socket on network 2 */

   tmpaddr = ntohl(g_net2_ipaddr);
   printf("NET2: Create receive socket: %d.%d.%d.%d:%d\n",
          (int)(tmpaddr >> 24),
          (int)((tmpaddr >> 16) & 0xff),
          (int)((tmpaddr >> 8) & 0xff),
          (int)(tmpaddr & 0xff),
          CONFIG_EXAMPLES_BRIDGE_NET2_RECVPORT);

   recvsd = socket(PF_INET, SOCK_DGRAM, 0);
   if (recvsd < 0)
     {
       fprintf(stderr, "NET2 ERROR: Failed to create receive socket: %d\n",
               errno);
       return EXIT_FAILURE;
     }

   /* Set socket to reuse address */

   optval = 1;
   if (setsockopt(recvsd, SOL_SOCKET, SO_REUSEADDR,
                  &optval, sizeof(int)) < 0)
     {
       fprintf(stderr, "NET2 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
               errno);
       goto errout_with_recvsd;
     }

   /* Bind the socket to a local address */

   receiver.sin_family      = AF_INET;
   receiver.sin_port        = HTONS(CONFIG_EXAMPLES_BRIDGE_NET2_RECVPORT);
   receiver.sin_addr.s_addr = g_net2_ipaddr;

   if (bind(recvsd, (struct sockaddr *)&receiver,
            sizeof(struct sockaddr_in)) < 0)
     {
       fprintf(stderr, "NET2 ERROR: bind failure: %d\n", errno);
       goto errout_with_recvsd;
     }

   /* Create a UDP send socket on network 1 */

   tmpaddr = ntohl(g_net1_ipaddr);
   printf("NET2: Create send socket: %d.%d.%d.%d:INPORT_ANY\n",
          (int)(tmpaddr >> 24),
          (int)((tmpaddr >> 16) & 0xff),
          (int)((tmpaddr >> 8) & 0xff),
          (int)(tmpaddr & 0xff));

   sndsd = socket(PF_INET, SOCK_DGRAM, 0);
   if (sndsd < 0)
     {
       fprintf(stderr, "NET2 ERROR: Failed to create send socket: %d\n",
               errno);
       goto errout_with_recvsd;
     }

   /* Set socket to reuse address */

   optval = 1;
   if (setsockopt(sndsd, SOL_SOCKET, SO_REUSEADDR, &optval,
                  sizeof(int)) < 0)
     {
       fprintf(stderr, "NET2 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
               errno);
       goto errout_with_sendsd;
     }

   /* Bind the socket to a local address */

   sender.sin_family      = AF_INET;
   sender.sin_port        = 0;
   sender.sin_addr.s_addr = g_net1_ipaddr;

   if (bind(sndsd, (struct sockaddr *)&sender,
            sizeof(struct sockaddr_in)) < 0)
     {
       printf("NET2: bind failure: %d\n", errno);
       goto errout_with_sendsd;
     }

   /* Then receive and forward UDP packets forever  */

   for (; ; )
     {
       /* Read a packet on network 2 */

       printf("NET2: Receiving up to %d bytes on network 2\n",
              CONFIG_EXAMPLES_BRIDGE_NET2_IOBUFIZE);

       addrlen = sizeof(struct sockaddr_in);
       nrecvd = recvfrom(recvsd, g_net2_buffer,
                         CONFIG_EXAMPLES_BRIDGE_NET2_IOBUFIZE, 0,
                         (FAR struct sockaddr *)&fromaddr, &addrlen);

       tmpaddr = ntohl(fromaddr.sin_addr.s_addr);
       printf("NET2: Received %ld bytes from %d.%d.%d.%d:%d\n",
              (long)nrecvd,
              (int)(tmpaddr >> 24),
              (int)((tmpaddr >> 16) & 0xff),
              (int)((tmpaddr >> 8) & 0xff),
              (int)(tmpaddr & 0xff),
              ntohs(fromaddr.sin_port));

       /* Check for a receive error or zero bytes received.  The negative
        * return value indicates a receive error; Zero would mean that the
        * other side of the "connection" performed an "orderly" shutdown.
        * This should not occur with a UDP socket and so must also be an
        * error of some kind.
        */

       if (nrecvd <= 0)
         {
           if (nrecvd < 0)
             {
               fprintf(stderr, "NET2 ERROR: recvfrom failed: %d\n", errno);
             }
           else
             {
               fprintf(stderr, "NET2 ERROR: recvfrom returned zero\n");
             }

           goto errout_with_sendsd;
         }

       /* Send the newly received packet out network 1 */

       printf("NET2: Sending %ld bytes on network 1: %d.%d.%d.%d:%d\n",
              (long)nrecvd,
              CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST >> 24,
              (CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST >> 16) & 0xff,
              (CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST >> 8) & 0xff,
              CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST & 0xff,
              CONFIG_EXAMPLES_BRIDGE_NET1_HOSTPORT);

       toaddr.sin_family      = AF_INET;
       toaddr.sin_port        = htons(CONFIG_EXAMPLES_BRIDGE_NET1_HOSTPORT);
       toaddr.sin_addr.s_addr = htonl(CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST);

       nsent = sendto(sndsd, g_net2_buffer, nrecvd, 0,
                      (struct sockaddr *)&toaddr, sizeof(struct sockaddr_in));

       /* Check for send errors */

       if (nsent < 0)
         {
           fprintf(stderr, "NET2 ERROR: sendto failed: %d\n", errno);
           goto errout_with_sendsd;
         }
       else if (nsent != nrecvd)
         {
           fprintf(stderr, "NET2 ERROR: Bad send length: %ld Expected: %ld\n",
                   (long)nsent, (long)nrecvd);
           goto errout_with_sendsd;
         }
     }

   close(recvsd);
   close(recvsd);
   return EXIT_SUCCESS;

 errout_with_sendsd:
   close(sndsd);
 errout_with_recvsd:
   close(recvsd);
   return EXIT_FAILURE;
 }

 /****************************************************************************
  * Public Functions
  ****************************************************************************/

 /****************************************************************************
  * bridge_main
  ****************************************************************************/

 int main(int argc, FAR char *argv[])
 {
   pid_t net1_worker;
   pid_t net2_worker;
   int ret;

   /* Initialize networks */

   ret = briget_net1_setup();
   if (ret != OK)
     {
       fprintf(stderr, "ERROR: Failed to setup network 1\n");
       return EXIT_FAILURE;
     }

   ret = briget_net2_setup();
   if (ret != OK)
     {
       fprintf(stderr, "ERROR: Failed to setup network 2\n");
       return EXIT_FAILURE;
     }

   /* Start network daemons */

   printf("Start network 1 worker\n");

   net1_worker = task_create("NET1 Worker",
                             CONFIG_EXAMPLES_BRIDGE_NET1_PRIORITY,
                             CONFIG_EXAMPLES_BRIDGE_NET1_STACKSIZE,
                             bridge_net1_worker,
                             NULL);
   if (net1_worker < 0)
     {
       fprintf(stderr, "ERROR: Failed to start network daemon 1\n");
       return EXIT_FAILURE;
     }

   printf("Start network 2 worker\n");

   net2_worker = task_create("NET2 Worker",
                             CONFIG_EXAMPLES_BRIDGE_NET2_PRIORITY,
                             CONFIG_EXAMPLES_BRIDGE_NET2_STACKSIZE,
                             bridge_net2_worker,
                             NULL);
   if (net2_worker < 0)
     {
       fprintf(stderr, "ERROR: Failed to start network daemon 2\n");
       return EXIT_FAILURE;
     }

   return EXIT_SUCCESS;
 }
	/****************************************************************************
	* apps/examples/bridge/bridge_main.c
	*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership. The
	* ASF licenses this file to you 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.
	*
	****************************************************************************/

	/****************************************************************************
	* Included Files
	****************************************************************************/

	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <sched.h>
	#include <errno.h>
	#include <debug.h>
	#include <unistd.h>

	#include <net/if.h>
	#include <arpa/inet.h>
	#include <netinet/in.h>

	#include "netutils/netlib.h"

	#if defined(CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC) \|\| \
	defined(CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC)
	# include "netutils/dhcpc.h"
	#endif

	/****************************************************************************
	* Pre-processor Definitions
	****************************************************************************/

	/****************************************************************************
	* Private Data
	****************************************************************************/

	static in_addr_t g_net1_ipaddr;
	static in_addr_t g_net2_ipaddr;
	static uint8_t g_net1_buffer[CONFIG_EXAMPLES_BRIDGE_NET1_IOBUFIZE];
	static uint8_t g_net2_buffer[CONFIG_EXAMPLES_BRIDGE_NET2_IOBUFIZE];

	/****************************************************************************
	* Private Functions
	****************************************************************************/

	/****************************************************************************
	* Name: briget_net1_setup
	****************************************************************************/

	static int briget_net1_setup(void)
	{
	/* If this task is executed as an NSH built-in function, then the
	* network has already been configured by NSH's start-up logic.
	*/

	#ifndef CONFIG_NSH_NETINIT
	struct in_addr addr;
	#if defined(CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC) \|\| \
	defined(CONFIG_EXAMPLES_BRIDGE_NET1_NOMAC)
	uint8_t mac[IFHWADDRLEN];
	#endif
	#ifdef CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC
	struct dhcpc_state ds;
	void *handle;
	char inetaddr[INET_ADDRSTRLEN];
	#endif

	printf("NET1: Configuring %s\n", CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME);

	/* Many embedded network interfaces must have a software assigned MAC */

	#ifdef CONFIG_EXAMPLES_BRIDGE_NET1_NOMAC
	mac[0] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 5)) & 0xff;
	mac[1] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 4)) & 0xff;
	mac[2] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 3)) & 0xff;
	mac[3] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 2)) & 0xff;
	mac[4] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 1)) & 0xff;
	mac[5] = (CONFIG_EXAMPLES_BRIDGE_NET1_MACADDR >> (8 * 0)) & 0xff;
	netlib_setmacaddr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, mac);
	#endif

	/* Set up our host address */

	#ifdef CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC
	addr.s_addr = 0;
	#else
	addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_IPADDR);
	#endif
	netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &addr);

	/* Set up the default router address */

	addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_DRIPADDR);
	netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &addr);

	/* Setup the subnet mask */

	addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_NETMASK);
	netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &addr);

	/* New versions of netlib_set_ipvXaddr will not bring the network up,
	* So ensure the network is really up at this point.
	*/

	netlib_ifup("eth0");

	#ifdef CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC
	/* Get the MAC address of the NIC */

	netlib_getmacaddr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, mac);

	/* Set up the DHCPC modules */

	handle = dhcpc_open("eth0", &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)
	{
	fprintf(stderr, "NET1 ERROR: dhcpc_open failed\n");
	return ERROR;
	}

	if (dhcpc_request(handle, &ds) != OK)
	{
	fprintf(stderr, "NET1 ERROR: dhcpc_request failed\n");
	return ERROR;
	}

	netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME, &ds.ipaddr);

	if (ds.netmask.s_addr != 0)
	{
	netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME,
	&ds.netmask);
	}

	if (ds.default_router.s_addr != 0)
	{
	netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET1_IFNAME,
	&ds.default_router);
	}

	if (ds.dnsaddr.s_addr != 0)
	{
	netlib_set_ipv4dnsaddr(&ds.dnsaddr);
	}

	dhcpc_close(handle);
	printf("NET1: Assigned IP: %s\n",
	net_ntoa_r(ds.ipaddr, inetaddr, sizeof(inetaddr)));

	/* Save the IP address in network order */

	g_net1_ipaddr = ds.ipaddr;

	#else
	/* Save the IP address in network order */

	g_net1_ipaddr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET1_IPADDR);

	#endif /* CONFIG_EXAMPLES_BRIDGE_NET1_DHCPC */

	#else /* CONFIG_NSH_NETINIT */
	/* Hmmm.. there is an issue here. Where do we get the IP address if we
	* are a builtin in application?
	*/
	# warning Missing logic

	#endif /* CONFIG_NSH_NETINIT */

	return OK;
	}

	/****************************************************************************
	* Name: briget_net2_setup
	****************************************************************************/

	static int briget_net2_setup(void)
	{
	/* If this task is executed as an NSH built-in function, then the
	* network has already been configured by NSH's start-up logic.
	*/

	#ifndef CONFIG_NSH_NETINIT
	struct in_addr addr;
	#if defined(CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC) \|\| \
	defined(CONFIG_EXAMPLES_BRIDGE_NET2_NOMAC)
	uint8_t mac[IFHWADDRLEN];
	#endif
	#ifdef CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC
	struct dhcpc_state ds;
	void *handle;
	char inetaddr[INET_ADDRSTRLEN];
	#endif

	printf("NET2: Configuring %s\n", CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME);

	/* Many embedded network interfaces must have a software assigned MAC */

	#ifdef CONFIG_EXAMPLES_BRIDGE_NET2_NOMAC
	mac[0] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 5)) & 0xff;
	mac[1] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 4)) & 0xff;
	mac[2] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 3)) & 0xff;
	mac[3] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 2)) & 0xff;
	mac[4] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 1)) & 0xff;
	mac[5] = (CONFIG_EXAMPLES_BRIDGE_NET2_MACADDR >> (8 * 0)) & 0xff;
	netlib_setmacaddr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, mac);
	#endif

	/* Set up our host address */

	#ifdef CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC
	addr.s_addr = 0;
	#else
	addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_IPADDR);
	#endif
	netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &addr);

	/* Set up the default router address */

	addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_DRIPADDR);
	netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &addr);

	/* Setup the subnet mask */

	addr.s_addr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_NETMASK);
	netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &addr);

	#ifdef CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC
	/* Get the MAC address of the NIC */

	netlib_getmacaddr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, 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)
	{
	fprintf(stderr, "NET2 ERROR: dhcpc_open failed\n");
	return ERROR;
	}

	if (dhcpc_request(handle, &ds) != OK)
	{
	fprintf(stderr, "NET2 ERROR: dhcpc_request failed\n");
	return ERROR;
	}

	netlib_set_ipv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME, &ds.ipaddr);

	if (ds.netmask.s_addr != 0)
	{
	netlib_set_ipv4netmask(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME,
	&ds.netmask);
	}

	if (ds.default_router.s_addr != 0)
	{
	netlib_set_dripv4addr(CONFIG_EXAMPLES_BRIDGE_NET2_IFNAME,
	&ds.default_router);
	}

	if (ds.dnsaddr.s_addr != 0)
	{
	netlib_set_ipv4dnsaddr(&ds.dnsaddr);
	}

	dhcpc_close(handle);
	printf("NET1: Assigned IP: %s\n",
	inet_ntoa_r(ds.ipaddr, inetaddr, sizeof(inetaddr)));

	/* Save the IP address in network order */

	g_net2_ipaddr = ds.ipaddr;

	#else
	/* Save the IP address in network order */

	g_net2_ipaddr = HTONL(CONFIG_EXAMPLES_BRIDGE_NET2_IPADDR);

	#endif /* CONFIG_EXAMPLES_BRIDGE_NET2_DHCPC */

	#else /* CONFIG_NSH_NETINIT */
	/* Hmmm.. there is an issue here. Where do we get the IP address if we
	* are a builtin in application?
	*/
	# warning Missing logic

	#endif /* CONFIG_NSH_NETINIT */

	return OK;
	}

	/****************************************************************************
	* Name: bridge_net1_worker
	****************************************************************************/

	static int bridge_net1_worker(int argc, char *argv[])
	{
	struct sockaddr_in receiver;
	struct sockaddr_in sender;
	struct sockaddr_in fromaddr;
	struct sockaddr_in toaddr;
	socklen_t addrlen;
	in_addr_t tmpaddr;
	ssize_t nrecvd;
	ssize_t nsent;
	int optval;
	int recvsd;
	int sndsd;

	printf("NET1: Worker started. PID=%d\n", getpid());

	/* Create a UDP receive socket on network 1 */

	tmpaddr = ntohl(g_net1_ipaddr);
	printf("NET1: Create receive socket: %d.%d.%d.%d:%d\n",
	(int)(tmpaddr >> 24),
	(int)((tmpaddr >> 16) & 0xff),
	(int)((tmpaddr >> 8) & 0xff),
	(int)(tmpaddr & 0xff),
	CONFIG_EXAMPLES_BRIDGE_NET1_RECVPORT);

	recvsd = socket(PF_INET, SOCK_DGRAM, 0);
	if (recvsd < 0)
	{
	fprintf(stderr, "NET1 ERROR: Failed to create receive socket: %d\n",
	errno);
	return EXIT_FAILURE;
	}

	/* Set socket to reuse address */

	optval = 1;
	if (setsockopt(recvsd, SOL_SOCKET, SO_REUSEADDR,
	&optval, sizeof(int)) < 0)
	{
	fprintf(stderr, "NET1 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
	errno);
	goto errout_with_recvsd;
	}

	/* Bind the socket to a local address */

	receiver.sin_family = AF_INET;
	receiver.sin_port = HTONS(CONFIG_EXAMPLES_BRIDGE_NET1_RECVPORT);
	receiver.sin_addr.s_addr = g_net1_ipaddr;

	if (bind(recvsd, (struct sockaddr *)&receiver,
	sizeof(struct sockaddr_in)) < 0)
	{
	fprintf(stderr, "NET1 ERROR: bind failure: %d\n", errno);
	goto errout_with_recvsd;
	}

	/* Create a UDP send socket on network 2 */

	tmpaddr = ntohl(g_net2_ipaddr);
	printf("NET1: Create send socket: %d.%d.%d.%d:INPORT_ANY\n",
	(int)(tmpaddr >> 24),
	(int)((tmpaddr >> 16) & 0xff),
	(int)((tmpaddr >> 8) & 0xff),
	(int)(tmpaddr & 0xff));

	sndsd = socket(PF_INET, SOCK_DGRAM, 0);
	if (sndsd < 0)
	{
	fprintf(stderr, "NET1 ERROR: Failed to create send socket: %d\n",
	errno);
	goto errout_with_recvsd;
	}

	/* Set socket to reuse address */

	optval = 1;
	if (setsockopt(sndsd, SOL_SOCKET, SO_REUSEADDR,
	&optval, sizeof(int)) < 0)
	{
	fprintf(stderr, "NET1 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
	errno);
	goto errout_with_sendsd;
	}

	/* Bind the socket to a local address */

	sender.sin_family = AF_INET;
	sender.sin_port = 0;
	sender.sin_addr.s_addr = g_net2_ipaddr;

	if (bind(sndsd, (struct sockaddr *)&sender,
	sizeof(struct sockaddr_in)) < 0)
	{
	printf("NET1: bind failure: %d\n", errno);
	goto errout_with_sendsd;
	}

	/* Then receive and forward UDP packets forever */

	for (; ; )
	{
	/* Read a packet on network 1 */

	printf("NET1: Receiving up to %d bytes on network 1\n",
	CONFIG_EXAMPLES_BRIDGE_NET1_IOBUFIZE);

	addrlen = sizeof(struct sockaddr_in);
	nrecvd = recvfrom(recvsd, g_net1_buffer,
	CONFIG_EXAMPLES_BRIDGE_NET1_IOBUFIZE, 0,
	(FAR struct sockaddr *)&fromaddr, &addrlen);

	tmpaddr = ntohl(fromaddr.sin_addr.s_addr);
	printf("NET1: Received %ld bytes from %d.%d.%d.%d:%d\n",
	(long)nrecvd,
	(int)(tmpaddr >> 24),
	(int)((tmpaddr >> 16) & 0xff),
	(int)((tmpaddr >> 8) & 0xff),
	(int)(tmpaddr & 0xff),
	ntohs(fromaddr.sin_port));

	/* Check for a receive error or zero bytes received. The negative
	* return value indicates a receive error; Zero would mean that the
	* other side of the "connection" performed an "orderly" shutdown.
	* This should not occur with a UDP socket and so must also be an
	* error of some kind.
	*/

	if (nrecvd <= 0)
	{
	if (nrecvd < 0)
	{
	fprintf(stderr, "NET1 ERROR: recvfrom failed: %d\n", errno);
	}
	else
	{
	fprintf(stderr, "NET1 ERROR: recvfrom returned zero\n");
	}

	goto errout_with_sendsd;
	}

	/* Send the newly received packet out network 2 */

	printf("NET1: Sending %ld bytes on network 2: %d.%d.%d.%d:%d\n",
	(long)nrecvd,
	CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST >> 24,
	(CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST >> 16) & 0xff,
	(CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST >> 8) & 0xff,
	CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST & 0xff,
	CONFIG_EXAMPLES_BRIDGE_NET2_HOSTPORT);

	toaddr.sin_family = AF_INET;
	toaddr.sin_port = htons(CONFIG_EXAMPLES_BRIDGE_NET2_HOSTPORT);
	toaddr.sin_addr.s_addr = htonl(CONFIG_EXAMPLES_BRIDGE_NET2_IPHOST);

	nsent = sendto(sndsd, g_net1_buffer, nrecvd, 0,
	(struct sockaddr *)&toaddr,
	sizeof(struct sockaddr_in));

	/* Check for send errors */

	if (nsent < 0)
	{
	fprintf(stderr, "NET1 ERROR: sendto failed: %d\n", errno);
	goto errout_with_sendsd;
	}
	else if (nsent != nrecvd)
	{
	fprintf(stderr, "NET1 ERROR: Bad send length: %ld Expected: %ld\n",
	(long)nsent, (long)nrecvd);
	goto errout_with_sendsd;
	}
	}

	close(recvsd);
	close(recvsd);
	return EXIT_SUCCESS;

	errout_with_sendsd:
	close(sndsd);
	errout_with_recvsd:
	close(recvsd);
	return EXIT_FAILURE;
	}

	/****************************************************************************
	* Name: bridge_net2_worker
	****************************************************************************/

	static int bridge_net2_worker(int argc, char *argv[])
	{
	struct sockaddr_in receiver;
	struct sockaddr_in sender;
	struct sockaddr_in fromaddr;
	struct sockaddr_in toaddr;
	socklen_t addrlen;
	in_addr_t tmpaddr;
	ssize_t nrecvd;
	ssize_t nsent;
	int optval;
	int recvsd;
	int sndsd;

	printf("NET2: Worker started. PID=%d\n", getpid());

	/* Create a UDP receive socket on network 2 */

	tmpaddr = ntohl(g_net2_ipaddr);
	printf("NET2: Create receive socket: %d.%d.%d.%d:%d\n",
	(int)(tmpaddr >> 24),
	(int)((tmpaddr >> 16) & 0xff),
	(int)((tmpaddr >> 8) & 0xff),
	(int)(tmpaddr & 0xff),
	CONFIG_EXAMPLES_BRIDGE_NET2_RECVPORT);

	recvsd = socket(PF_INET, SOCK_DGRAM, 0);
	if (recvsd < 0)
	{
	fprintf(stderr, "NET2 ERROR: Failed to create receive socket: %d\n",
	errno);
	return EXIT_FAILURE;
	}

	/* Set socket to reuse address */

	optval = 1;
	if (setsockopt(recvsd, SOL_SOCKET, SO_REUSEADDR,
	&optval, sizeof(int)) < 0)
	{
	fprintf(stderr, "NET2 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
	errno);
	goto errout_with_recvsd;
	}

	/* Bind the socket to a local address */

	receiver.sin_family = AF_INET;
	receiver.sin_port = HTONS(CONFIG_EXAMPLES_BRIDGE_NET2_RECVPORT);
	receiver.sin_addr.s_addr = g_net2_ipaddr;

	if (bind(recvsd, (struct sockaddr *)&receiver,
	sizeof(struct sockaddr_in)) < 0)
	{
	fprintf(stderr, "NET2 ERROR: bind failure: %d\n", errno);
	goto errout_with_recvsd;
	}

	/* Create a UDP send socket on network 1 */

	tmpaddr = ntohl(g_net1_ipaddr);
	printf("NET2: Create send socket: %d.%d.%d.%d:INPORT_ANY\n",
	(int)(tmpaddr >> 24),
	(int)((tmpaddr >> 16) & 0xff),
	(int)((tmpaddr >> 8) & 0xff),
	(int)(tmpaddr & 0xff));

	sndsd = socket(PF_INET, SOCK_DGRAM, 0);
	if (sndsd < 0)
	{
	fprintf(stderr, "NET2 ERROR: Failed to create send socket: %d\n",
	errno);
	goto errout_with_recvsd;
	}

	/* Set socket to reuse address */

	optval = 1;
	if (setsockopt(sndsd, SOL_SOCKET, SO_REUSEADDR, &optval,
	sizeof(int)) < 0)
	{
	fprintf(stderr, "NET2 ERROR: setsockopt SO_REUSEADDR failure: %d\n",
	errno);
	goto errout_with_sendsd;
	}

	/* Bind the socket to a local address */

	sender.sin_family = AF_INET;
	sender.sin_port = 0;
	sender.sin_addr.s_addr = g_net1_ipaddr;

	if (bind(sndsd, (struct sockaddr *)&sender,
	sizeof(struct sockaddr_in)) < 0)
	{
	printf("NET2: bind failure: %d\n", errno);
	goto errout_with_sendsd;
	}

	/* Then receive and forward UDP packets forever */

	for (; ; )
	{
	/* Read a packet on network 2 */

	printf("NET2: Receiving up to %d bytes on network 2\n",
	CONFIG_EXAMPLES_BRIDGE_NET2_IOBUFIZE);

	addrlen = sizeof(struct sockaddr_in);
	nrecvd = recvfrom(recvsd, g_net2_buffer,
	CONFIG_EXAMPLES_BRIDGE_NET2_IOBUFIZE, 0,
	(FAR struct sockaddr *)&fromaddr, &addrlen);

	tmpaddr = ntohl(fromaddr.sin_addr.s_addr);
	printf("NET2: Received %ld bytes from %d.%d.%d.%d:%d\n",
	(long)nrecvd,
	(int)(tmpaddr >> 24),
	(int)((tmpaddr >> 16) & 0xff),
	(int)((tmpaddr >> 8) & 0xff),
	(int)(tmpaddr & 0xff),
	ntohs(fromaddr.sin_port));

	/* Check for a receive error or zero bytes received. The negative
	* return value indicates a receive error; Zero would mean that the
	* other side of the "connection" performed an "orderly" shutdown.
	* This should not occur with a UDP socket and so must also be an
	* error of some kind.
	*/

	if (nrecvd <= 0)
	{
	if (nrecvd < 0)
	{
	fprintf(stderr, "NET2 ERROR: recvfrom failed: %d\n", errno);
	}
	else
	{
	fprintf(stderr, "NET2 ERROR: recvfrom returned zero\n");
	}

	goto errout_with_sendsd;
	}

	/* Send the newly received packet out network 1 */

	printf("NET2: Sending %ld bytes on network 1: %d.%d.%d.%d:%d\n",
	(long)nrecvd,
	CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST >> 24,
	(CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST >> 16) & 0xff,
	(CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST >> 8) & 0xff,
	CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST & 0xff,
	CONFIG_EXAMPLES_BRIDGE_NET1_HOSTPORT);

	toaddr.sin_family = AF_INET;
	toaddr.sin_port = htons(CONFIG_EXAMPLES_BRIDGE_NET1_HOSTPORT);
	toaddr.sin_addr.s_addr = htonl(CONFIG_EXAMPLES_BRIDGE_NET1_IPHOST);

	nsent = sendto(sndsd, g_net2_buffer, nrecvd, 0,
	(struct sockaddr *)&toaddr, sizeof(struct sockaddr_in));

	/* Check for send errors */

	if (nsent < 0)
	{
	fprintf(stderr, "NET2 ERROR: sendto failed: %d\n", errno);
	goto errout_with_sendsd;
	}
	else if (nsent != nrecvd)
	{
	fprintf(stderr, "NET2 ERROR: Bad send length: %ld Expected: %ld\n",
	(long)nsent, (long)nrecvd);
	goto errout_with_sendsd;
	}
	}

	close(recvsd);
	close(recvsd);
	return EXIT_SUCCESS;

	errout_with_sendsd:
	close(sndsd);
	errout_with_recvsd:
	close(recvsd);
	return EXIT_FAILURE;
	}

	/****************************************************************************
	* Public Functions
	****************************************************************************/

	/****************************************************************************
	* bridge_main
	****************************************************************************/

	int main(int argc, FAR char *argv[])
	{
	pid_t net1_worker;
	pid_t net2_worker;
	int ret;

	/* Initialize networks */

	ret = briget_net1_setup();
	if (ret != OK)
	{
	fprintf(stderr, "ERROR: Failed to setup network 1\n");
	return EXIT_FAILURE;
	}

	ret = briget_net2_setup();
	if (ret != OK)
	{
	fprintf(stderr, "ERROR: Failed to setup network 2\n");
	return EXIT_FAILURE;
	}

	/* Start network daemons */

	printf("Start network 1 worker\n");

	net1_worker = task_create("NET1 Worker",
	CONFIG_EXAMPLES_BRIDGE_NET1_PRIORITY,
	CONFIG_EXAMPLES_BRIDGE_NET1_STACKSIZE,
	bridge_net1_worker,
	NULL);
	if (net1_worker < 0)
	{
	fprintf(stderr, "ERROR: Failed to start network daemon 1\n");
	return EXIT_FAILURE;
	}

	printf("Start network 2 worker\n");

	net2_worker = task_create("NET2 Worker",
	CONFIG_EXAMPLES_BRIDGE_NET2_PRIORITY,
	CONFIG_EXAMPLES_BRIDGE_NET2_STACKSIZE,
	bridge_net2_worker,
	NULL);
	if (net2_worker < 0)
	{
	fprintf(stderr, "ERROR: Failed to start network daemon 2\n");
	return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;
	}