From 5bb854e504a0db968b47c0a983d0148629e126e7 Mon Sep 17 00:00:00 2001
From: Adam Ierymenko <adam.ierymenko@gmail.com>
Date: Tue, 28 Oct 2014 17:25:34 -0700
Subject: Fix a nasty bug introduced in packet fragmentation a while back
 during refactoring, and a few other things related to multicast.

---
 node/Multicaster.cpp       | 15 +++++++++++----
 node/OutboundMulticast.hpp |  2 +-
 node/Packet.hpp            |  7 ++++---
 node/Switch.cpp            |  8 +++++---
 4 files changed, 21 insertions(+), 11 deletions(-)

(limited to 'node')

diff --git a/node/Multicaster.cpp b/node/Multicaster.cpp
index 94c6a45b..4d1b82d4 100644
--- a/node/Multicaster.cpp
+++ b/node/Multicaster.cpp
@@ -325,7 +325,7 @@ void Multicaster::clean(uint64_t now)
 		// so that remaining members can be sorted in ascending order of
 		// transmit priority.
 		std::vector<MulticastGroupMember>::iterator reader(mm->second.members.begin());
-		std::vector<MulticastGroupMember>::iterator writer(mm->second.members.begin());
+		std::vector<MulticastGroupMember>::iterator writer(reader);
 		unsigned int count = 0;
 		while (reader != mm->second.members.end()) {
 			if ((now - reader->timestamp) < ZT_MULTICAST_LIKE_EXPIRE) {
@@ -363,7 +363,10 @@ void Multicaster::clean(uint64_t now)
 		} else if (mm->second.txQueue.empty()) {
 			// There are no remaining members and no pending multicasts, so erase the entry
 			_groups.erase(mm++);
-		} else ++mm;
+		} else {
+			mm->second.members.clear();
+			++mm;
+		}
 	}
 }
 
@@ -399,10 +402,14 @@ void Multicaster::_add(uint64_t now,uint64_t nwid,const MulticastGroup &mg,Multi
 	SharedPtr<Peer> p(RR->topology->getPeer(member));
 	if ((!p)||(!p->remoteVersionKnown())||(p->remoteVersionMajor() >= 1)) {
 		for(std::list<OutboundMulticast>::iterator tx(gs.txQueue.begin());tx!=gs.txQueue.end();) {
-			tx->sendIfNew(RR,member);
 			if (tx->atLimit())
 				gs.txQueue.erase(tx++);
-			else ++tx;
+			else {
+				tx->sendIfNew(RR,member);
+				if (tx->atLimit())
+					gs.txQueue.erase(tx++);
+				else ++tx;
+			}
 		}
 	}
 }
diff --git a/node/OutboundMulticast.hpp b/node/OutboundMulticast.hpp
index ab0aae55..f87656eb 100644
--- a/node/OutboundMulticast.hpp
+++ b/node/OutboundMulticast.hpp
@@ -102,7 +102,7 @@ public:
 	/**
 	 * @return True if this outbound multicast has been sent to enough peers
 	 */
-	inline bool atLimit() const throw() { return (_alreadySentTo.size() > _limit); }
+	inline bool atLimit() const throw() { return (_alreadySentTo.size() >= _limit); }
 
 	/**
 	 * Just send without checking log
diff --git a/node/Packet.hpp b/node/Packet.hpp
index a6ac9dc6..2d2c11e2 100644
--- a/node/Packet.hpp
+++ b/node/Packet.hpp
@@ -35,11 +35,12 @@
 #include <string>
 #include <iostream>
 
+#include "Constants.hpp"
+
 #include "Address.hpp"
 #include "Poly1305.hpp"
 #include "Salsa20.hpp"
 #include "Utils.hpp"
-#include "Constants.hpp"
 #include "Buffer.hpp"
 
 #include "../ext/lz4/lz4.h"
@@ -425,13 +426,13 @@ public:
 			setSize(fragLen + ZT_PROTO_MIN_FRAGMENT_LENGTH);
 
 			// NOTE: this copies both the IV/packet ID and the destination address.
-			memcpy(field(ZT_PACKET_FRAGMENT_IDX_PACKET_ID,13),field(ZT_PACKET_IDX_IV,13),13);
+			memcpy(field(ZT_PACKET_FRAGMENT_IDX_PACKET_ID,13),p.field(ZT_PACKET_IDX_IV,13),13);
 
 			(*this)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR] = ZT_PACKET_FRAGMENT_INDICATOR;
 			(*this)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_NO] = (char)(((fragTotal & 0xf) << 4) | (fragNo & 0xf));
 			(*this)[ZT_PACKET_FRAGMENT_IDX_HOPS] = 0;
 
-			memcpy(field(ZT_PACKET_FRAGMENT_IDX_PAYLOAD,fragLen),field(fragStart,fragLen),fragLen);
+			memcpy(field(ZT_PACKET_FRAGMENT_IDX_PAYLOAD,fragLen),p.field(fragStart,fragLen),fragLen);
 		}
 
 		/**
diff --git a/node/Switch.cpp b/node/Switch.cpp
index 4819bd56..7c63761b 100644
--- a/node/Switch.cpp
+++ b/node/Switch.cpp
@@ -785,9 +785,9 @@ bool Switch::_trySend(const Packet &packet,bool encrypt)
 					++fragsRemaining;
 				unsigned int totalFragments = fragsRemaining + 1;
 
-				for(unsigned int f=0;f<fragsRemaining;++f) {
+				for(unsigned int fno=1;fno<totalFragments;++fno) {
 					chunkSize = std::min(remaining,(unsigned int)(ZT_UDP_DEFAULT_PAYLOAD_MTU - ZT_PROTO_MIN_FRAGMENT_LENGTH));
-					Packet::Fragment frag(tmp,fragStart,chunkSize,f + 1,totalFragments);
+					Packet::Fragment frag(tmp,fragStart,chunkSize,fno,totalFragments);
 					via->send(RR,frag.data(),frag.size(),now);
 					fragStart += chunkSize;
 					remaining -= chunkSize;
@@ -795,7 +795,9 @@ bool Switch::_trySend(const Packet &packet,bool encrypt)
 			}
 			return true;
 		}
-	} else requestWhois(packet.destination());
+	} else {
+		requestWhois(packet.destination());
+	}
 	return false;
 }
 
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