From 8bb25f535c14694a0a1f2533aa01355407655f35 Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Fri, 23 Jul 2021 16:50:11 +0000
Subject: [PATCH] Clarify HopByHop padding code, addressing LGTM.com finding

---
 libnetutil/HopByHopHeader.cc | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/libnetutil/HopByHopHeader.cc b/libnetutil/HopByHopHeader.cc
index 708daff15..1cfdf64aa 100644
--- a/libnetutil/HopByHopHeader.cc
+++ b/libnetutil/HopByHopHeader.cc
@@ -369,21 +369,21 @@ int HopByHopHeader::addOption(u8 type, u8 len, const u8 *data){
  * this method adds the necessary padding (either PadN or Pad1 options)*/
 int HopByHopHeader::addPadding(){
   u8 zeroes[8]={0,0,0,0,0,0,0,0};
-  int required_octets=8-(this->length%8);
+  // required_octets in range [0,7]
+  int required_octets=(8 - (this->length % 8)) % 8;
 
   /* Make sure we have enough space for the padding. */
   if ( (this->length+required_octets) > HOPBYHOP_MAX_HEADER_LEN )
     return OP_FAILURE;
 
   /* Insert Pad1 or PadN to fill the necessary octets */
-  if(required_octets>0 && required_octets<8){
-      if(required_octets==1){
-          curr_option[0]=EXTOPT_PAD1;
-          curr_option++;
-          this->length++;
-      }else{
-          this->addOption(EXTOPT_PADN, required_octets-2, zeroes );
-      }
+  if (required_octets == 1) {
+    curr_option[0]=EXTOPT_PAD1;
+    curr_option++;
+    this->length++;
+  }
+  else if (required_octets > 0) {
+    this->addOption(EXTOPT_PADN, required_octets-2, zeroes );
   }
   assert(this->length%8==0);
   this->h.len=(this->length/8)-1;