From e69088a2edb284f748570158097465e4c879e13c Mon Sep 17 00:00:00 2001
From: Aaron Taylor <ataylor@subgeniuskitty.com>
Date: Mon, 7 Oct 2019 04:19:28 -0700
Subject: [PATCH 1/1] Updated timeval_diff() to calculate a full difference.

---
 icmpmonitor.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/icmpmonitor.c b/icmpmonitor.c
index efa6d71..6bc2006 100644
--- a/icmpmonitor.c
+++ b/icmpmonitor.c
@@ -100,12 +100,16 @@ checksum(const uint16_t * data)
 }
 
 /*
- * Calculate difference between two timeval structs to within one second.
+ * Calculate difference (a-b) between two timeval structs.
  */
 void
 timeval_diff(struct timeval * a, const struct timeval * b)
 {
-    assert(a->tv_sec >= b->tv_sec);
+    if (a->tv_usec < b->tv_usec) {
+        a->tv_sec--;
+        a->tv_usec += 1000000;
+    }
+    a->tv_usec -= b->tv_usec;
     a->tv_sec -= b->tv_sec;
 }
 
-- 
2.20.1