From 2c9dfa2823b30638bc2f7166c15008b722ddebbe Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@meshlink.io>
Date: Sat, 9 Aug 2014 19:15:22 +0200
Subject: [PATCH] Allow variable packet loss rates to be set in the test
 program.

---
 test.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/test.c b/test.c
index 10ebc9a..cda5f17 100644
--- a/test.c
+++ b/test.c
@@ -16,6 +16,8 @@
 struct utcp_connection *c;
 int dir = 3;
 bool running = true;
+double dropin;
+double dropout;
 
 int do_recv(struct utcp_connection *c, const void *data, size_t len) {
 	if(!data || !len) {
@@ -38,11 +40,15 @@ void do_accept(struct utcp_connection *nc, uint16_t port) {
 
 int do_send(struct utcp *utcp, const void *data, size_t len) {
 	int s = *(int *)utcp->priv;
-	return send(s, data, len, MSG_DONTWAIT);
+	if(drand48() >= dropout)
+		return send(s, data, len, MSG_DONTWAIT);
+	else
+		return 0;
 }
 
 int main(int argc, char *argv[]) {
 	srand(time(NULL));
+	srand48(time(NULL));
 
 	if(argc < 2 || argc > 3)
 		return 1;
@@ -50,6 +56,9 @@ int main(int argc, char *argv[]) {
 	bool server = argc == 2;
 	bool connected = false;
 
+	dropin = atof(getenv("DROPIN") ?: "0");
+	dropout = atof(getenv("DROPOUT") ?: "0");
+
 	struct addrinfo *ai;
 	struct addrinfo hint = {
 		.ai_flags = server ? AI_PASSIVE : 0,
@@ -118,7 +127,8 @@ int main(int argc, char *argv[]) {
 			if(!connected)
 				if(!connect(s, (struct sockaddr *)&ss, sl))
 					connected = true;
-			utcp_recv(u, buf, len);
+			if(drand48() >= dropin)
+				utcp_recv(u, buf, len);
 		}
 
 		timeout = utcp_timeout(u);
-- 
2.39.2