Add RESYNC command to allow automatic recovery from a detected desync

src/modules/m_spanningtree/compat.cpp

@@ -143,6 +143,11 @@ void TreeSocket::WriteLine(std::string line)
 				line.erase(b,c-b);
 			}
 		}
+		else if (proto_version < 1203 && command == "RESYNC")
+		{
+			// drop the command. 2.0 and earlier cannot automatically recover from desync
+			return;
+		}
 		else if (proto_version < 1202 && command == "ENCAP")
 		{
 			// :src ENCAP target command [args...]

src/modules/m_spanningtree/fjoin.cpp

@@ -56,6 +56,7 @@ CmdResult CommandFJoin::Handle(const std::vector<std::string>& params, User *src
 	irc::tokenstream users((params.size() > 3) ? params[params.size() - 1] : "");   /* users from the user list */
 	bool apply_other_sides_modes = true;				/* True if we are accepting the other side's modes */
 	Channel* chan = ServerInstance->FindChan(channel);		/* The channel we're sending joins to */
+	bool incremental = (params[2] == "*");
 	bool created = !chan;						/* True if the channel doesnt exist here yet */
 	std::string item;						/* One item in the list of nicks */
 
@@ -71,7 +72,13 @@ CmdResult CommandFJoin::Handle(const std::vector<std::string>& params, User *src
 	if (created)
 	{
 		chan = new Channel(channel, TS);
-		ServerInstance->SNO->WriteToSnoMask('d', "Creation FJOIN recieved for %s, timestamp: %lu", chan->name.c_str(), (unsigned long)TS);
+		if (incremental)
+		{
+			ServerInstance->SNO->WriteToSnoMask('d', "Incremental creation FJOIN recieved for %s, timestamp: %lu", chan->name.c_str(), (unsigned long)TS);
+			parameterlist resync;
+			resync.push_back(channel);
+			Utils->DoOneToOne(ServerInstance->Config->GetSID().c_str(), "RESYNC", resync, srcuser->uuid);
+		}
 	}
 	else
 	{
@@ -97,12 +104,19 @@ CmdResult CommandFJoin::Handle(const std::vector<std::string>& params, User *src
 			chan->age = TS;
 			param_list.push_back(channel);
 			this->RemoveStatus(ServerInstance->FakeClient, param_list);
+			if (incremental)
+			{
+				ServerInstance->SNO->WriteToSnoMask('d', "Incremental merge FJOIN recieved for %s, timestamp: %lu", chan->name.c_str(), (unsigned long)TS);
+				parameterlist resync;
+				resync.push_back(channel);
+				Utils->DoOneToOne(ServerInstance->Config->GetSID().c_str(), "RESYNC", resync, srcuser->uuid);
+			}
 		}
 		// The silent case here is ourTS == TS, we don't need to remove modes here, just to merge them later on.
 	}
 
 	/* First up, apply their modes if they won the TS war */
-	if (apply_other_sides_modes)
+	if (apply_other_sides_modes && !incremental)
 	{
 		unsigned int idx = 2;
 		std::vector<std::string> modelist;

src/modules/m_spanningtree/main.cpp

@@ -611,9 +611,7 @@ void ModuleSpanningTree::OnUserJoin(Membership* memb, bool sync, bool created, C
 		// new joining permissions for the user.
 		params.push_back(memb->chan->name);
 		params.push_back(ConvToStr(memb->chan->age));
-		irc::modestacker ms;
-		memb->chan->ChanModes(ms, MODELIST_SHORT);
-		params.push_back(ms.popModeLine(FORMAT_NETWORK, 400, INT_MAX));
+		params.push_back("*");
 		params.push_back(memb->modes+","+std::string(memb->user->uuid));
 		Utils->DoOneToMany(ServerInstance->Config->GetSID(),"FJOIN",params);
 	}

src/modules/m_spanningtree/main.h

@@ -26,7 +26,7 @@
  * Failure to document your protocol changes will result in a painfully
  * painful death by pain. You have been warned.
  */
-const long ProtocolVersion = 1202;
+const long ProtocolVersion = 1203;
 const long MinCompatProtocol = 1201;
 
 /** Forward declarations

src/modules/m_spanningtree/netburst.cpp

@@ -81,7 +81,7 @@ void TreeSocket::SendServers(TreeServer* Current, TreeServer* s, int hops)
  * If the length of a single line is more than 480-NICKMAX
  * in length, it is split over multiple lines.
  */
-void TreeSocket::SendFJoins(TreeServer* Current, Channel* c)
+void TreeSocket::SendFJoins(Channel* c)
 {
 	char list[MAXBUF];
 
@@ -138,6 +138,22 @@ void TreeSocket::SendFJoins(TreeServer* Current, Channel* c)
 	snprintf(list, MAXBUF, ":%s FMODE %s %ld ", ServerInstance->Config->GetSID().c_str(), c->name.c_str(), (unsigned long)c->age);
 	while (!fmodes.empty())
 		WriteLine(list + fmodes.popModeLine(FORMAT_NETWORK));
+
+	if (!c->topic.empty())
+	{
+		snprintf(list,MAXBUF,":%s FTOPIC %s %lu %s :%s", ServerInstance->Config->GetSID().c_str(), c->name.c_str(), (unsigned long)c->topicset, c->setby.c_str(), c->topic.c_str());
+		WriteLine(list);
+	}
+
+	for(Extensible::ExtensibleStore::const_iterator i = c->GetExtList().begin(); i != c->GetExtList().end(); i++)
+	{
+		ExtensionItem* item = i->first;
+		std::string value = item->serialize(FORMAT_NETWORK, c, i->second);
+		if (!value.empty())
+			sync.SendMetaData(c, item->name, value);
+	}
+
+	FOREACH_MOD(I_OnSyncChannel,OnSyncChannel(c, &sync));
 }
 
 /** Send G, Q, Z and E lines */
@@ -183,28 +199,9 @@ void TreeSocket::SendXLines(TreeServer* Current)
 /** Send channel modes and topics */
 void TreeSocket::SendChannelModes(TreeServer* Current)
 {
-	char data[MAXBUF];
-	std::deque<std::string> list;
-	std::string n = ServerInstance->Config->GetSID();
-	const char* sn = n.c_str();
 	for (chan_hash::iterator c = ServerInstance->chanlist->begin(); c != ServerInstance->chanlist->end(); c++)
 	{
-		SendFJoins(Current, c->second);
-		if (!c->second->topic.empty())
-		{
-			snprintf(data,MAXBUF,":%s FTOPIC %s %lu %s :%s", sn, c->second->name.c_str(), (unsigned long)c->second->topicset, c->second->setby.c_str(), c->second->topic.c_str());
-			this->WriteLine(data);
-		}
-
-		for(Extensible::ExtensibleStore::const_iterator i = c->second->GetExtList().begin(); i != c->second->GetExtList().end(); i++)
-		{
-			ExtensionItem* item = i->first;
-			std::string value = item->serialize(FORMAT_NETWORK, c->second, i->second);
-			if (!value.empty())
-				sync.SendMetaData(c->second, item->name, value);
-		}
-
-		FOREACH_MOD(I_OnSyncChannel,OnSyncChannel(c->second,&sync));
+		SendFJoins(c->second);
 	}
 }
 

src/modules/m_spanningtree/treesocket.h

@@ -218,7 +218,7 @@ class TreeSocket : public BufferedSocket
 	 * If the length of a single line is more than 480-NICKMAX
 	 * in length, it is split over multiple lines.
 	 */
-	void SendFJoins(TreeServer* Current, Channel* c);
+	void SendFJoins(Channel* c);
 
 	/** Send G, Q, Z and E lines */
 	void SendXLines(TreeServer* Current);

src/modules/m_spanningtree/treesocket2.cpp

@@ -289,6 +289,12 @@ void TreeSocket::ProcessConnectedLine(std::string& prefix, std::string& command,
 	{
 		this->Away(prefix,params);
 	}
+	else if (command == "RESYNC" && !params.empty())
+	{
+		Channel* chan = ServerInstance->FindChan(params[0]);
+		if (chan)
+			SendFJoins(chan);
+	}
 	else if (command == "PING")
 	{
 		this->LocalPing(prefix,params);