From e3121f52a7fa6e91061f9553ecc72214d071983a Mon Sep 17 00:00:00 2001
From: Frediano Ziglio <fziglio@redhat.com>
Date: Sat, 8 Oct 2016 22:43:45 +0100
Subject: Add bandwidth test

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
---
 .gitignore        |   1 +
 tests/Makefile.am |   4 ++
 tests/bandwidth.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 139 insertions(+)
 create mode 100644 tests/bandwidth.c

diff --git a/.gitignore b/.gitignore
index d453e3b..f781164 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,4 +21,5 @@ latency.spec
 ar-lib
 tests/libtest.a
 tests/delay
+tests/bandwidth
 .*.swp
diff --git a/tests/Makefile.am b/tests/Makefile.am
index b3c9f45..9a98d58 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -15,3 +15,7 @@ LDADD = \
 
 TESTS += delay
 delay_SOURCES = delay.c
+
+TESTS += bandwidth
+bandwidth_SOURCES = bandwidth.c
+bandwidth_LDFLAGS = -pthread
diff --git a/tests/bandwidth.c b/tests/bandwidth.c
new file mode 100644
index 0000000..3e2fe59
--- /dev/null
+++ b/tests/bandwidth.c
@@ -0,0 +1,134 @@
+/* check that the delay we setup is respected */
+#include "common.h"
+#include "../utils.h"
+#include <poll.h>
+#include <pthread.h>
+
+#define MIN_IP_UDP_HEADER 28
+
+static int udp_socks[2] = { -1, -1 };
+
+typedef struct {
+	uint8_t data[1024];
+} test_payload;
+
+#define SOCK2PTR(s) ((void *)(uintptr_t)(s))
+#define PTR2SOCK(p) ((int)(uintptr_t)(p))
+
+static void *
+send_proc(void *arg)
+{
+	int sock = PTR2SOCK(arg);
+	test_payload payload;
+
+	int n;
+	for (n = 0; n < sizeof(payload.data); ++n)
+		payload.data[n] = n * 123 + 456;
+
+	uint64_t start_time = get_time_us();
+	while (get_time_us() - start_time < 130 * 1000) {
+		send(sock, &payload, sizeof(payload), MSG_NOSIGNAL);
+		send(sock, &payload, sizeof(payload), MSG_NOSIGNAL);
+		send(sock, &payload, sizeof(payload), MSG_NOSIGNAL);
+		send(sock, &payload, sizeof(payload), MSG_NOSIGNAL);
+		send(sock, &payload, sizeof(payload), MSG_NOSIGNAL);
+		usleep(1000);
+	}
+	return NULL;
+}
+
+static void *
+recv_proc(void *arg)
+{
+	int sock = PTR2SOCK(arg);
+	test_payload payload;
+
+	uint64_t bytes_received = 0;
+	uint64_t start_time = 0;
+	for (;;) {
+		ssize_t len = recv(sock, &payload, sizeof(payload), MSG_TRUNC);
+		assert(len > 0);
+
+		uint64_t curr_time = get_time_us();
+		assert(bytes_received <= 0xffffffffu - len - MIN_IP_UDP_HEADER);
+		if (start_time == 0)
+			start_time = curr_time;
+		else
+			bytes_received += len + MIN_IP_UDP_HEADER;
+		if (curr_time - start_time >= 100 * 1000)
+			break;
+	}
+	return (void *) (uintptr_t) bytes_received;
+}
+
+static void
+flush_socks(void)
+{
+	struct pollfd fds[2];
+	int i;
+
+	fds[0].fd = udp_socks[0];
+	fds[0].events = POLLIN;
+	fds[1].fd = udp_socks[1];
+	fds[1].events = POLLIN;
+	for (;;) {
+		// wait any packet for 30 ms
+		fds[0].revents = 0;
+		fds[1].revents = 0;
+		int res = poll(fds, 2, 30);
+		if (res == 0)
+			break;
+
+		for (i = 0; i < 2; ++i) {
+			char buf[1024];
+			if (fds[i].revents)
+				recv(fds[i].fd, buf, sizeof(buf), MSG_TRUNC);
+		}
+	}
+}
+
+static void
+test_bandwidth(unsigned bw)
+{
+	pthread_t th[3];
+	void *thread_res;
+	unsigned bytes_received;
+	unsigned expected = 1024 * 1024 * bw / 8 / 10 + 1 * (1024 + MIN_IP_UDP_HEADER);
+
+	// launch program with given latency
+	launch_latency("10 %uMbit", bw);
+	create_udp_pair(udp_socks);
+
+	// one direction
+	assert(pthread_create(th, NULL, recv_proc, SOCK2PTR(udp_socks[1])) == 0);
+	send_proc(SOCK2PTR(udp_socks[0]));
+	assert(pthread_join(th[0], &thread_res) == 0);
+	bytes_received = (uintptr_t) thread_res;
+	printf("received %u/%u\n", bytes_received, expected);
+	// check into -5% to +5%
+	assert(bytes_received >= expected * 0.96 && bytes_received <= expected * 1.04);
+
+	// other direction
+	flush_socks();
+	assert(pthread_create(th, NULL, recv_proc, SOCK2PTR(udp_socks[0])) == 0);
+	send_proc(SOCK2PTR(udp_socks[1]));
+	assert(pthread_join(th[0], &thread_res) == 0);
+	bytes_received = (uintptr_t) thread_res;
+	printf("received %u/%u\n", bytes_received, expected);
+	// check into -5% to +5%
+	assert(bytes_received >= expected * 0.96 && bytes_received <= expected * 1.04);
+
+	close_udp_pair(udp_socks);
+	kill_latency();
+}
+
+int main(void)
+{
+	printf("Testing bandwidth limitation\n");
+
+	test_bandwidth(2);
+	test_bandwidth(4);
+	test_bandwidth(8);
+	test_bandwidth(16);
+	return 0;
+}
-- 
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