From 23e47d52915c70515b8aa828e2ec3b2272a280d7 Mon Sep 17 00:00:00 2001
From: Pieter Willem Jordaan <pieterwjordaanpc@gmail.com>
Date: Thu, 24 Sep 2015 07:10:58 +0000
Subject: [PATCH 1/2] Exponential backoff retransmits

This commit fixes https://github.com/xelerance/xl2tpd/issues/76
---
 network.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/network.c b/network.c
index b1268c63..b840d302 100644
--- a/network.c
+++ b/network.c
@@ -30,6 +30,8 @@
 #include "ipsecmast.h"
 #include "misc.h"    /* for IPADDY macro */
 
+#include <math.h>
+
 char hostname[256];
 struct sockaddr_in server, from;        /* Server and transmitter structs */
 int server_socket;              /* Server socket */
@@ -264,9 +266,9 @@ void control_xmit (void *b)
     else
     {
         /*
-           * FIXME:  How about adaptive timeouts?
+           * Adaptive timeout with exponential backoff
          */
-        tv.tv_sec = 1;
+        tv.tv_sec = 1*pow(2, buf->retries-1);
         tv.tv_usec = 0;
         schedule (tv, control_xmit, buf);
 #ifdef DEBUG_CONTROL_XMIT

From 64f8ad1ab68b4b12f848b2d995a8f5da2bf0c4f0 Mon Sep 17 00:00:00 2001
From: Pieter Willem Jordaan <pieterwjordaanpc@gmail.com>
Date: Thu, 24 Sep 2015 07:12:57 +0000
Subject: [PATCH 2/2] libm needed in Makefile

libm was added into the Makefile
---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index 5d6bed3c..4620a134 100644
--- a/Makefile
+++ b/Makefile
@@ -103,6 +103,7 @@ OBJS=xl2tpd.o pty.o misc.o control.o avp.o call.o network.o avpsend.o scheduler.
 SRCS=${OBJS:.o=.c} ${HDRS}
 CONTROL_SRCS=xl2tpd-control.c
 #LIBS= $(OSLIBS) # -lefence # efence for malloc checking
+LDLIBS= -lm
 EXEC=xl2tpd
 CONTROL_EXEC=xl2tpd-control