IEEE802.11 packet use after move RTS/CTS mode logic error

[sgalgano]

Reported via email by David Ward:

Fixed a bug in the 802.11 model which prevented RTS/CTS from ever being used. The old version tried to access a variable which had been moved, causing it to always return 0.

Developed by: Chris Pollard

diff --git a/src/models/mac/ieee80211abg/maclayer.cc b/src/models/mac/ieee80211abg/maclayer.cc
index bf5a18f..d743a29 100644
--- a/src/models/mac/ieee80211abg/maclayer.cc
+++ b/src/models/mac/ieee80211abg/maclayer.cc
@@ -1161,6 +1161,7 @@ EMANE::Models::IEEE80211ABG::MACLayer::processDownstreamPacket(DownstreamPacket
   std::uint8_t u8Retries{isBroadcast(pktInfo.getDestination()) ?
       std::uint8_t{} : macConfig_.getRetryLimit(u8Category)};

+  // this moves pkt, making it invalid, use entry.pkt_ from now on
   DownstreamQueueEntry entry{pkt, 
       timeNow, 
       macConfig_.getTxOpMicroseconds(u8Category), 
@@ -1168,7 +1169,7 @@ EMANE::Models::IEEE80211ABG::MACLayer::processDownstreamPacket(DownstreamPacket
       u8Retries};

   // check rts cts enable
-  if((macConfig_.getRtsThreshold() != 0) &&(macConfig_.getRtsThreshold() <= pkt.length()))
+  if((macConfig_.getRtsThreshold() != 0) &&(macConfig_.getRtsThreshold() <= entry.pkt_.length()))
     {
       // set rts cts flag
       entry.bRtsCtsEnable_ = true;