samples/net/test_15_4/src/network.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /* network.c - Networking demo */

 /*
  * Copyright (c) 2015 Intel Corporation.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <zephyr.h>

 #if defined(CONFIG_STDOUT_CONSOLE)
 #include <stdio.h>
 #define PRINT           printf
 #else
 #include <misc/printk.h>
 #define PRINT           printk
 #endif

 #ifdef CONFIG_NET_SANITY_TEST
 #include <tc_util.h>
 #endif

 #include <net/ip_buf.h>
 #include <net/net_core.h>
 #include <net/net_socket.h>
 #include <net_driver_15_4.h>

 /* The following uIP includes are for testing purposes only. Never
  * ever use them in your application.
  */
 #include "contiki/ipv6/uip-ds6-route.h"  /* to set the route */
 #include "contiki/ipv6/uip-ds6-nbr.h"    /* to set the neighbor cache */

 #ifndef CONFIG_NET_15_4_LOOPBACK_NUM
 #define CONFIG_NET_15_4_LOOPBACK_NUM 0
 #endif

 #if 0
 #define SRC_IPADDR  { { { 0xfe,0x80,0,0,0,0,0,0,0x08,0xbe,0xef,0x2d,0xbc,0x15,0xf0,0x0d } } }
 #define DEST_IPADDR { { { 0xfe,0x80,0,0,0,0,0,0,0x08,0xbe,0xef,0x2d,0xbc,0x15,0xf0,0x0d } } }
 #define SRC_PORT       0xF0B1
 #define DEST_PORT      0xF0B0

 const struct in6_addr in6addr_src = SRC_IPADDR;
 const struct in6_addr in6addr_dest = DEST_IPADDR;

 /* source mac address */
 uint8_t src_mac[] = { 0x0a, 0xbe, 0xef, 0x2d, 0xbc, 0x15, 0xf0, 0x0d };
 /* destincation mac address */
 const uip_lladdr_t dest_mac = { { 0x0a, 0xbe, 0xef, 0x2d, 0xbc, 0x15, 0xf0, 0x0d } };

 #else

 #define SRC_PORT       0
 #define DEST_PORT      4242

 const struct in6_addr in6addr_src = IN6ADDR_ANY_INIT; /* ::  */
 const struct in6_addr in6addr_dest = IN6ADDR_LOOPBACK_INIT;  /* ::1 */
 /* source mac address */
 uint8_t src_mac[] = { 0x0a, 0xbe, 0xef, 0x2d, 0xbc, 0x15, 0xf0, 0x0d };
 /* destincation mac address */
 const uip_lladdr_t dest_mac = { };

 #endif

 static struct net_addr loopback_addr;
 static struct net_addr any_addr;

 #ifdef CONFIG_NET_SANITY_TEST
 static int loopback = 0;
 static int test_rp = TC_PASS;
 #endif

 /* Generated by http://www.lipsum.com/
  * 2 paragraphs, 185 words, 1230 bytes of Lorem Ipsum
  * The send_data() will add one null byte at the end and
  * 6lowpan needs one byte header so the maximum
  * length for the data to send is 1231 bytes.
  */
 #if 0
 static const char *lorem_ipsum =
 	"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam congue non neque vel tempor. In id porta nibh, ut cursus tortor. Morbi eleifend tristique vehicula. Nunc vitae risus mauris. Praesent vel imperdiet dolor, et ultricies nibh. Aliquam erat volutpat.";
 #else
 static const char *lorem_ipsum =
 	"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam congue non neque vel tempor. In id porta nibh, ut cursus tortor. Morbi eleifend tristique vehicula. Nunc vitae risus mauris. Praesent vel imperdiet dolor, et ultricies nibh. Aliquam erat volutpat. Maecenas pellentesque dolor vitae dictum tincidunt. Fusce vel nibh nec leo tristique auctor eu a massa. Nam et tellus ac tortor sollicitudin semper vitae nec tortor. Aliquam nec lacus velit. Maecenas ornare ullamcorper justo non auctor. Donec aliquam feugiat turpis, quis elementum sem rutrum ut. Sed eu ullamcorper libero, ut suscipit magna."
 	"\n"
 	"Donec vehicula magna ut varius aliquam. Ut vitae commodo nulla, quis ornare dolor. Nulla tortor sem, venenatis eu iaculis id, commodo ut massa. Sed est lorem, euismod vitae enim sed, hendrerit gravida felis. Donec eros lacus, auctor ut ultricies eget, lobortis quis nisl. Aliquam sit amet blandit eros. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque egestas nisl leo, sed consectetur leo ornare eu. Suspendisse vitae urna vel purus maximus finibus. Proin sed sollicitudin turpis. Mauris interdum neque eu tellus pellentesque, id fringilla nisi fermentum. Suspendisse gravida pharetra sodales orci aliquam";
 #endif

 static inline void init_test()
 {
 	PRINT("%s: run 802.15.4 loopback tester\n", __func__);

 	net_set_mac(src_mac, sizeof(src_mac));

 	any_addr.in6_addr = in6addr_src;
 	any_addr.family = AF_INET6;

 	loopback_addr.in6_addr = in6addr_dest;
 	loopback_addr.family = AF_INET6;
 }

 static void set_routes()
 {
 	/* Workaround to get packets from this task to listening fiber.
 	 * Do not attempt to do anything like this in live environment.
 	 */
 	if (!uip_ds6_nbr_add((uip_ipaddr_t *)&in6addr_dest,
 					&dest_mac, 0, NBR_REACHABLE))
 		PRINT("Cannot add neighbor cache\n");

 	if (!uip_ds6_route_add((uip_ipaddr_t *)&in6addr_dest, 128,
 					(uip_ipaddr_t *)&in6addr_dest))
 		PRINT("Cannot add localhost route\n");
 }

 static void send_data(const char *taskname, struct net_context *ctx)
 {
 	int len = strlen(lorem_ipsum);
 	struct net_buf *buf;

 	buf = ip_buf_get_tx(ctx);
 	if (buf) {
 		uint8_t *ptr;
 		uint16_t sent_len;

 		ptr = net_buf_add(buf, 0);
 		memcpy(ptr, lorem_ipsum, len);
 		ptr = net_buf_add(buf, len);
 		ptr = net_buf_add(buf, 1); /* add \0 */
 		*ptr = '\0';
 		sent_len = buf->len;

 		if (net_send(buf) < 0) {
 			PRINT("%s: %s(): sending %d bytes failed\n",
 			      taskname, __func__, len);
 			ip_buf_unref(buf);
 		} else {
 			PRINT("%s: %s(): sent %d bytes\n", taskname,
 			      __func__, sent_len);
 		}
 	}
 }

 static void receive_data(const char *taskname, struct net_context *ctx)
 {
 	struct net_buf *buf;
 #ifdef CONFIG_NET_SANITY_TEST
 	int rp;
 #endif

 	buf = net_receive(ctx, TICKS_NONE);
 	if (buf) {
 		PRINT("%s: %s(): received %d bytes\n", taskname,
 		      __func__, ip_buf_appdatalen(buf));
 		if (memcmp(ip_buf_appdata(buf),
 			   lorem_ipsum, strlen(lorem_ipsum))) {
 			PRINT("ERROR: data does not match\n");

 #ifdef CONFIG_NET_SANITY_TEST
 			rp = TC_FAIL;
 		} else {
 			rp = TC_PASS;
 #endif
 		}

 		ip_buf_unref(buf);

 #ifdef CONFIG_NET_SANITY_TEST
 		loopback++;
 		test_rp = test_rp && rp;
 		TC_END_RESULT(rp);

 		if (loopback == CONFIG_NET_15_4_LOOPBACK_NUM) {
 			loopback = 0;
 			TC_END_REPORT(test_rp);
 		}
 #endif
 	}
 }

 static struct net_context *get_context(const struct net_addr *remote,
 				       uint16_t remote_port,
 				       struct net_addr *local,
 				       uint16_t local_port)
 {
 	struct net_context *ctx;

 	ctx = net_context_get(IPPROTO_UDP,
 			      remote, remote_port,
 			      local, local_port);
 	if (!ctx) {
 		PRINT("%s: Cannot get network context\n", __func__);
 		return NULL;
 	}

 	return ctx;
 }

 #ifdef CONFIG_MICROKERNEL

 /*
  * Microkernel version of hello world demo has two tasks that utilize
  * semaphores and sleeps to take turns printing a greeting message at
  * a controlled rate.
  */

 /* specify delay between greetings (in ms); compute equivalent in ticks */

 #define SLEEPTIME  500
 #define SLEEPTICKS (SLEEPTIME * sys_clock_ticks_per_sec / 1000)

 /* specify delay between greetings (in ms); compute equivalent in ticks */

 #define SLEEPTIME  500
 #define SLEEPTICKS (SLEEPTIME * sys_clock_ticks_per_sec / 1000)

 /*
  *
  * @param taskname    task identification string
  * @param mySem       task's own semaphore
  * @param otherSem    other task's semaphore
  *
  */
 static void listen(const char *taskname, ksem_t mySem, ksem_t otherSem,
 		   struct net_context *ctx)
 {
 	int i = 0;

 	while (1) {
 		task_sem_take(mySem, TICKS_UNLIMITED);

 		receive_data(taskname, ctx);

 		if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
 					i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
 			task_sem_give(otherSem);
 			return;
 		}

 		/* wait a while, then let other task have a turn */
 		task_sleep(SLEEPTICKS);
 		task_sem_give(otherSem);
 		i++;
 	}
 }

 void taskA(void)
 {
 	struct net_context *ctx;

 	net_init();
 	init_test();

 	ctx = get_context(&any_addr, SRC_PORT, &loopback_addr, DEST_PORT);
 	if (!ctx) {
 		PRINT("%s: Cannot get network context\n", __func__);
 		return;
 	}

 	/* taskA gives its own semaphore, allowing it to say hello right away */
 	task_sem_give(TASKASEM);

 	listen(__func__, TASKASEM, TASKBSEM, ctx);
 }

 static void send(const char *taskname, ksem_t mySem, ksem_t otherSem,
 		 struct net_context *ctx)
 {
 	int i = 0;

 	while (1) {
 		if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
 					i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
 			task_sem_give(otherSem);
 			return;
 		}

 		task_sem_take(mySem, TICKS_UNLIMITED);

 		send_data(taskname, ctx);

 		/* wait a while, then let other task have a turn */
 		task_sleep(SLEEPTICKS);
 		task_sem_give(otherSem);
 		i++;
 	}
 }

 void taskB(void)
 {
 	struct net_context *ctx;

 	ctx = get_context(&loopback_addr, DEST_PORT, &any_addr, SRC_PORT);
 	if (!ctx) {
 		PRINT("%s: Cannot get network context\n", __func__);
 		return;
 	}

 	set_routes();

 	send(__func__, TASKBSEM, TASKASEM, ctx);
 }

 #else /*  CONFIG_NANOKERNEL */

 /*
  * Nanokernel version of hello world demo has a task and a fiber that utilize
  * semaphores and timers to take turns printing a greeting message at
  * a controlled rate.
  */

 /* specify delay between greetings (in ms); compute equivalent in ticks */

 #ifdef CONFIG_NETWORKING_WITH_15_4_LOOPBACK_UART
 #define SLEEPTIME  2000
 #else
 /* No need to sleep so long if we are using the loopback without uart */
 #define SLEEPTIME  100
 #endif
 #define SLEEPTICKS (SLEEPTIME * sys_clock_ticks_per_sec / 1000)

 #define STACKSIZE 2000

 char fiberStack_sending[STACKSIZE];
 char fiberStack_receiving[STACKSIZE];

 void fiber_receiving(void)
 {
 	struct nano_timer timer;
 	uint32_t data[2] = {0, 0};
 	struct net_context *ctx;
 	int i = 0;

 	ctx = get_context(&any_addr, SRC_PORT, &loopback_addr, DEST_PORT);
 	if (!ctx) {
 		PRINT("%s: Cannot get network context\n", __func__);
 		return;
 	}

 	nano_timer_init(&timer, data);

 	while (1) {
 		receive_data("listenFiber", ctx);

 		if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
 					i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
 			nano_fiber_timer_stop(&timer);
 			return;
 		}

 		nano_fiber_timer_start(&timer, SLEEPTICKS);
 		nano_fiber_timer_test(&timer, TICKS_UNLIMITED);
 		i++;
 	}
 }

 void fiber_sending(void)
 {
 	struct nano_timer timer;
 	uint32_t data[2] = {0, 0};
 	struct net_context *ctx;
 	int i = 0;

 	ctx = get_context(&loopback_addr, DEST_PORT, &any_addr, SRC_PORT);
 	if (!ctx) {
 		PRINT("Cannot get network context\n");
 		return;
 	}

 	nano_timer_init(&timer, data);

 	while (1) {
 		if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
 					i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
 			nano_fiber_timer_stop(&timer);
 			return;
 		}

 		send_data("sendFiber", ctx);

 		nano_fiber_timer_start(&timer, SLEEPTICKS);
 		nano_fiber_timer_test(&timer, TICKS_UNLIMITED);
 		i++;
 	}
 }

 void main(void)
 {
 	PRINT("%s: run test_15_4\n", __func__);

 	net_init();
 	init_test();

 	set_routes();

 	task_fiber_start(&fiberStack_receiving[0], STACKSIZE,
 			 (nano_fiber_entry_t) fiber_receiving, 0, 0, 7, 0);

 	task_fiber_start(&fiberStack_sending[0], STACKSIZE,
 			 (nano_fiber_entry_t) fiber_sending, 0, 0, 7, 0);
 }

 #endif /* CONFIG_MICROKERNEL ||  CONFIG_NANOKERNEL */
	/* network.c - Networking demo */

	/*
	* Copyright (c) 2015 Intel Corporation.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <zephyr.h>

	#if defined(CONFIG_STDOUT_CONSOLE)
	#include <stdio.h>
	#define PRINT printf
	#else
	#include <misc/printk.h>
	#define PRINT printk
	#endif

	#ifdef CONFIG_NET_SANITY_TEST
	#include <tc_util.h>
	#endif

	#include <net/ip_buf.h>
	#include <net/net_core.h>
	#include <net/net_socket.h>
	#include <net_driver_15_4.h>

	/* The following uIP includes are for testing purposes only. Never
	* ever use them in your application.
	*/
	#include "contiki/ipv6/uip-ds6-route.h" /* to set the route */
	#include "contiki/ipv6/uip-ds6-nbr.h" /* to set the neighbor cache */

	#ifndef CONFIG_NET_15_4_LOOPBACK_NUM
	#define CONFIG_NET_15_4_LOOPBACK_NUM 0
	#endif

	#if 0
	#define SRC_IPADDR { { { 0xfe,0x80,0,0,0,0,0,0,0x08,0xbe,0xef,0x2d,0xbc,0x15,0xf0,0x0d } } }
	#define DEST_IPADDR { { { 0xfe,0x80,0,0,0,0,0,0,0x08,0xbe,0xef,0x2d,0xbc,0x15,0xf0,0x0d } } }
	#define SRC_PORT 0xF0B1
	#define DEST_PORT 0xF0B0

	const struct in6_addr in6addr_src = SRC_IPADDR;
	const struct in6_addr in6addr_dest = DEST_IPADDR;

	/* source mac address */
	uint8_t src_mac[] = { 0x0a, 0xbe, 0xef, 0x2d, 0xbc, 0x15, 0xf0, 0x0d };
	/* destincation mac address */
	const uip_lladdr_t dest_mac = { { 0x0a, 0xbe, 0xef, 0x2d, 0xbc, 0x15, 0xf0, 0x0d } };

	#else

	#define SRC_PORT 0
	#define DEST_PORT 4242

	const struct in6_addr in6addr_src = IN6ADDR_ANY_INIT; /* :: */
	const struct in6_addr in6addr_dest = IN6ADDR_LOOPBACK_INIT; /* ::1 */
	/* source mac address */
	uint8_t src_mac[] = { 0x0a, 0xbe, 0xef, 0x2d, 0xbc, 0x15, 0xf0, 0x0d };
	/* destincation mac address */
	const uip_lladdr_t dest_mac = { };

	#endif

	static struct net_addr loopback_addr;
	static struct net_addr any_addr;

	#ifdef CONFIG_NET_SANITY_TEST
	static int loopback = 0;
	static int test_rp = TC_PASS;
	#endif

	/* Generated by http://www.lipsum.com/
	* 2 paragraphs, 185 words, 1230 bytes of Lorem Ipsum
	* The send_data() will add one null byte at the end and
	* 6lowpan needs one byte header so the maximum
	* length for the data to send is 1231 bytes.
	*/
	#if 0
	static const char *lorem_ipsum =
	"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam congue non neque vel tempor. In id porta nibh, ut cursus tortor. Morbi eleifend tristique vehicula. Nunc vitae risus mauris. Praesent vel imperdiet dolor, et ultricies nibh. Aliquam erat volutpat.";
	#else
	static const char *lorem_ipsum =
	"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam congue non neque vel tempor. In id porta nibh, ut cursus tortor. Morbi eleifend tristique vehicula. Nunc vitae risus mauris. Praesent vel imperdiet dolor, et ultricies nibh. Aliquam erat volutpat. Maecenas pellentesque dolor vitae dictum tincidunt. Fusce vel nibh nec leo tristique auctor eu a massa. Nam et tellus ac tortor sollicitudin semper vitae nec tortor. Aliquam nec lacus velit. Maecenas ornare ullamcorper justo non auctor. Donec aliquam feugiat turpis, quis elementum sem rutrum ut. Sed eu ullamcorper libero, ut suscipit magna."
	"\n"
	"Donec vehicula magna ut varius aliquam. Ut vitae commodo nulla, quis ornare dolor. Nulla tortor sem, venenatis eu iaculis id, commodo ut massa. Sed est lorem, euismod vitae enim sed, hendrerit gravida felis. Donec eros lacus, auctor ut ultricies eget, lobortis quis nisl. Aliquam sit amet blandit eros. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque egestas nisl leo, sed consectetur leo ornare eu. Suspendisse vitae urna vel purus maximus finibus. Proin sed sollicitudin turpis. Mauris interdum neque eu tellus pellentesque, id fringilla nisi fermentum. Suspendisse gravida pharetra sodales orci aliquam";
	#endif

	static inline void init_test()
	{
	PRINT("%s: run 802.15.4 loopback tester\n", __func__);

	net_set_mac(src_mac, sizeof(src_mac));

	any_addr.in6_addr = in6addr_src;
	any_addr.family = AF_INET6;

	loopback_addr.in6_addr = in6addr_dest;
	loopback_addr.family = AF_INET6;
	}

	static void set_routes()
	{
	/* Workaround to get packets from this task to listening fiber.
	* Do not attempt to do anything like this in live environment.
	*/
	if (!uip_ds6_nbr_add((uip_ipaddr_t *)&in6addr_dest,
	&dest_mac, 0, NBR_REACHABLE))
	PRINT("Cannot add neighbor cache\n");

	if (!uip_ds6_route_add((uip_ipaddr_t *)&in6addr_dest, 128,
	(uip_ipaddr_t *)&in6addr_dest))
	PRINT("Cannot add localhost route\n");
	}

	static void send_data(const char taskname, struct net_context ctx)
	{
	int len = strlen(lorem_ipsum);
	struct net_buf *buf;

	buf = ip_buf_get_tx(ctx);
	if (buf) {
	uint8_t *ptr;
	uint16_t sent_len;

	ptr = net_buf_add(buf, 0);
	memcpy(ptr, lorem_ipsum, len);
	ptr = net_buf_add(buf, len);
	ptr = net_buf_add(buf, 1); /* add \0 */
	*ptr = '\0';
	sent_len = buf->len;

	if (net_send(buf) < 0) {
	PRINT("%s: %s(): sending %d bytes failed\n",
	taskname, __func__, len);
	ip_buf_unref(buf);
	} else {
	PRINT("%s: %s(): sent %d bytes\n", taskname,
	__func__, sent_len);
	}
	}
	}

	static void receive_data(const char taskname, struct net_context ctx)
	{
	struct net_buf *buf;
	#ifdef CONFIG_NET_SANITY_TEST
	int rp;
	#endif

	buf = net_receive(ctx, TICKS_NONE);
	if (buf) {
	PRINT("%s: %s(): received %d bytes\n", taskname,
	__func__, ip_buf_appdatalen(buf));
	if (memcmp(ip_buf_appdata(buf),
	lorem_ipsum, strlen(lorem_ipsum))) {
	PRINT("ERROR: data does not match\n");

	#ifdef CONFIG_NET_SANITY_TEST
	rp = TC_FAIL;
	} else {
	rp = TC_PASS;
	#endif
	}

	ip_buf_unref(buf);

	#ifdef CONFIG_NET_SANITY_TEST
	loopback++;
	test_rp = test_rp && rp;
	TC_END_RESULT(rp);

	if (loopback == CONFIG_NET_15_4_LOOPBACK_NUM) {
	loopback = 0;
	TC_END_REPORT(test_rp);
	}
	#endif
	}
	}

	static struct net_context get_context(const struct net_addr remote,
	uint16_t remote_port,
	struct net_addr *local,
	uint16_t local_port)
	{
	struct net_context *ctx;

	ctx = net_context_get(IPPROTO_UDP,
	remote, remote_port,
	local, local_port);
	if (!ctx) {
	PRINT("%s: Cannot get network context\n", __func__);
	return NULL;
	}

	return ctx;
	}

	#ifdef CONFIG_MICROKERNEL

	/*
	* Microkernel version of hello world demo has two tasks that utilize
	* semaphores and sleeps to take turns printing a greeting message at
	* a controlled rate.
	*/

	/* specify delay between greetings (in ms); compute equivalent in ticks */

	#define SLEEPTIME 500
	#define SLEEPTICKS (SLEEPTIME * sys_clock_ticks_per_sec / 1000)

	/* specify delay between greetings (in ms); compute equivalent in ticks */

	#define SLEEPTIME 500
	#define SLEEPTICKS (SLEEPTIME * sys_clock_ticks_per_sec / 1000)

	/*
	*
	* @param taskname task identification string
	* @param mySem task's own semaphore
	* @param otherSem other task's semaphore
	*
	*/
	static void listen(const char *taskname, ksem_t mySem, ksem_t otherSem,
	struct net_context *ctx)
	{
	int i = 0;

	while (1) {
	task_sem_take(mySem, TICKS_UNLIMITED);

	receive_data(taskname, ctx);

	if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
	i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
	task_sem_give(otherSem);
	return;
	}

	/* wait a while, then let other task have a turn */
	task_sleep(SLEEPTICKS);
	task_sem_give(otherSem);
	i++;
	}
	}

	void taskA(void)
	{
	struct net_context *ctx;

	net_init();
	init_test();

	ctx = get_context(&any_addr, SRC_PORT, &loopback_addr, DEST_PORT);
	if (!ctx) {
	PRINT("%s: Cannot get network context\n", __func__);
	return;
	}

	/* taskA gives its own semaphore, allowing it to say hello right away */
	task_sem_give(TASKASEM);

	listen(__func__, TASKASEM, TASKBSEM, ctx);
	}

	static void send(const char *taskname, ksem_t mySem, ksem_t otherSem,
	struct net_context *ctx)
	{
	int i = 0;

	while (1) {
	if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
	i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
	task_sem_give(otherSem);
	return;
	}

	task_sem_take(mySem, TICKS_UNLIMITED);

	send_data(taskname, ctx);

	/* wait a while, then let other task have a turn */
	task_sleep(SLEEPTICKS);
	task_sem_give(otherSem);
	i++;
	}
	}

	void taskB(void)
	{
	struct net_context *ctx;

	ctx = get_context(&loopback_addr, DEST_PORT, &any_addr, SRC_PORT);
	if (!ctx) {
	PRINT("%s: Cannot get network context\n", __func__);
	return;
	}

	set_routes();

	send(__func__, TASKBSEM, TASKASEM, ctx);
	}

	#else /* CONFIG_NANOKERNEL */

	/*
	* Nanokernel version of hello world demo has a task and a fiber that utilize
	* semaphores and timers to take turns printing a greeting message at
	* a controlled rate.
	*/

	/* specify delay between greetings (in ms); compute equivalent in ticks */

	#ifdef CONFIG_NETWORKING_WITH_15_4_LOOPBACK_UART
	#define SLEEPTIME 2000
	#else
	/* No need to sleep so long if we are using the loopback without uart */
	#define SLEEPTIME 100
	#endif
	#define SLEEPTICKS (SLEEPTIME * sys_clock_ticks_per_sec / 1000)

	#define STACKSIZE 2000

	char fiberStack_sending[STACKSIZE];
	char fiberStack_receiving[STACKSIZE];

	void fiber_receiving(void)
	{
	struct nano_timer timer;
	uint32_t data[2] = {0, 0};
	struct net_context *ctx;
	int i = 0;

	ctx = get_context(&any_addr, SRC_PORT, &loopback_addr, DEST_PORT);
	if (!ctx) {
	PRINT("%s: Cannot get network context\n", __func__);
	return;
	}

	nano_timer_init(&timer, data);

	while (1) {
	receive_data("listenFiber", ctx);

	if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
	i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
	nano_fiber_timer_stop(&timer);
	return;
	}

	nano_fiber_timer_start(&timer, SLEEPTICKS);
	nano_fiber_timer_test(&timer, TICKS_UNLIMITED);
	i++;
	}
	}

	void fiber_sending(void)
	{
	struct nano_timer timer;
	uint32_t data[2] = {0, 0};
	struct net_context *ctx;
	int i = 0;

	ctx = get_context(&loopback_addr, DEST_PORT, &any_addr, SRC_PORT);
	if (!ctx) {
	PRINT("Cannot get network context\n");
	return;
	}

	nano_timer_init(&timer, data);

	while (1) {
	if (CONFIG_NET_15_4_LOOPBACK_NUM != 0 &&
	i >= CONFIG_NET_15_4_LOOPBACK_NUM) {
	nano_fiber_timer_stop(&timer);
	return;
	}

	send_data("sendFiber", ctx);

	nano_fiber_timer_start(&timer, SLEEPTICKS);
	nano_fiber_timer_test(&timer, TICKS_UNLIMITED);
	i++;
	}
	}

	void main(void)
	{
	PRINT("%s: run test_15_4\n", __func__);

	net_init();
	init_test();

	set_routes();

	task_fiber_start(&fiberStack_receiving[0], STACKSIZE,
	(nano_fiber_entry_t) fiber_receiving, 0, 0, 7, 0);

	task_fiber_start(&fiberStack_sending[0], STACKSIZE,
	(nano_fiber_entry_t) fiber_sending, 0, 0, 7, 0);
	}

	#endif /* CONFIG_MICROKERNEL \|\| CONFIG_NANOKERNEL */