Merge pull request #167 from attilamolnar/insp21+spanningtree1204

[2.1] Spanningtree protocol version 1204

src/modules/m_spanningtree/compat.cpp

@@ -207,6 +207,46 @@ void TreeSocket::WriteLine(std::string line)
 				}
 			}
 		}
+		else if (proto_version < 1204 && command == "METADATA")
+		{
+			// Drop TS for channel METADATA
+			// :sid METADATA #target TS extname ...
+			//     A        B       C  D
+			if (b == std::string::npos)
+				return;
+			std::string::size_type c = line.find(' ', b + 1);
+			if (c == std::string::npos)
+				return;
+
+			if (line[b + 1] == '#')
+			{
+				// We're sending a channel metadata indeed
+				std::string::size_type d = line.find(' ', c + 1);
+				if (d == std::string::npos)
+					return;
+
+				ServerInstance->Logs->Log("m_spanningtree", DEBUG, "Stripping channel TS in METADATA for pre-1204-protocol server");
+				line.erase(c, d-c);
+			}
+		}
+		else if (proto_version < 1204 && command == "FTOPIC")
+		{
+			// Drop channel TS for FTOPIC
+			// :sid FTOPIC #target TS TopicTS ...
+			//     A      B       C  D
+			if (b == std::string::npos)
+				return;
+			std::string::size_type c = line.find(' ', b + 1);
+			if (c == std::string::npos)
+				return;
+
+			std::string::size_type d = line.find(' ', c + 1);
+			if (d == std::string::npos)
+				return;
+
+			ServerInstance->Logs->Log("m_spanningtree", DEBUG, "Stripping channel TS in FTOPIC for pre-1204-protocol server");
+			line.erase(c, d-c);
+		}
 	}
 
 	ServerInstance->Logs->Log("m_spanningtree", RAWIO, "S[%d] O %s", this->GetFd(), line.c_str());

src/modules/m_spanningtree/ftopic.cpp

@@ -28,24 +28,85 @@
 /** FTOPIC command */
 CmdResult CommandFTopic::Handle(const std::vector<std::string>& params, User *user)
 {
-	time_t ts = atoi(params[1].c_str());
 	Channel* c = ServerInstance->FindChan(params[0]);
-	if (c)
+	if ((!c) || (!IS_SERVER(user)))
+		return CMD_FAILURE;
+
+	/**
+	 * Here's how this works:
+	 *
+	 * In pre-1204 protocol version we had a syntax like
+	 *
+	 * FTOPIC #chan topicts setby :topic
+	 *
+	 * where topicts is the time when the topic was set, and setby is the n!u@h
+	 * of the user who set it. If the topicts value was bigger (newer) than our topic
+	 * TS (stored in Channel::topicset), we accepted the change, else we assumed
+	 * we already had a more recent topic and did nothing.
+	 *
+	 * However this behavior meant that if the channel was recreated on a server
+	 * during a netsplit, users there could set any topic and override ours with it
+	 * at merge because their topic had a newer topic TS.
+	 * Protocol version 1204 addresses this issue by adding the channel TS to FTOPIC:
+	 *
+	 * FTOPIC #chan chants topicts setby :topic
+	 *
+	 * so we notice when the channel has been recreated and discard the FTOPIC in that case.
+	 * Apart from this the logic remains the same. For previous versions not supporting the
+	 * new syntax we need to fall back to the old behavior.
+	 *
+	 */
+
+	// Determine the protocol version of the sender
+	SpanningTreeUtilities* Utils = ((ModuleSpanningTree*) (Module*) creator)->Utils;
+	TreeServer* srcserver = Utils->FindServer(user->server);
+	bool has_chants = (srcserver->Socket->proto_version >= 1204);
+
+	// If we got a channel TS compare it with ours. If it's different, drop the command.
+	// Also drop the command if we are using 1204, but there aren't enough parameters.
+	if (has_chants)
+	{
+		if (params.size() < 5)
+			return CMD_FAILURE;
+
+		// Only proceed if the TSes are equal. If their TS is newer the channel
+		// got recreated on their side, if it's older that means things are messed up,
+		// because they haven't sent us an FJOIN earlier which could lower the chan TS.
+		if (ConvToInt(params[1]) != c->age)
+			return CMD_FAILURE;
+	}
+
+	// Now do things as usual but if required, apply an offset to the index when accessing params
+	unsigned int indexoffset = (has_chants ? 1 : 0);
+	time_t topicts = ConvToInt(params[1+indexoffset]);
+
+	// See if the topic they sent is newer than ours (or we don't have a topic at all)
+	if ((topicts >= c->topicset) || (c->topic.empty()))
 	{
-		if ((ts >= c->topicset) || (c->topic.empty()))
+		if (c->topic != params[3+indexoffset])
 		{
-			if (c->topic != params[3])
-			{
-				// Update topic only when it differs from current topic
-				c->topic.assign(params[3], 0, ServerInstance->Config->Limits.MaxTopic);
-				c->WriteChannel(user, "TOPIC %s :%s", c->name.c_str(), c->topic.c_str());
-			}
-
-			// Always update setter and settime.
-			c->setby.assign(params[2], 0, 127);
-			c->topicset = ts;
+			// Update topic only when it differs from current topic
+			c->topic.assign(params[3+indexoffset], 0, ServerInstance->Config->Limits.MaxTopic);
+			c->WriteChannel(user, "TOPIC %s :%s", c->name.c_str(), c->topic.c_str());
 		}
+
+		// Always update setter and settime.
+		c->setby.assign(params[2+indexoffset], 0, 127);
+		c->topicset = topicts;
+	}
+	else
+	{
+		// We got a newer topic than this one, keep ours and drop the command
+		return CMD_FAILURE;
 	}
+
+	// They haven't sent us a channel TS, add ours before passing the command on
+	if (!has_chants)
+	{
+		parameterlist& p = const_cast<parameterlist&>(params);
+		p.insert(p.begin()+1, ConvToStr(c->age));
+	}
+
 	return CMD_SUCCESS;
 }
 

src/modules/m_spanningtree/main.h

@@ -36,7 +36,7 @@
  * Failure to document your protocol changes will result in a painfully
  * painful death by pain. You have been warned.
  */
-const long ProtocolVersion = 1203;
+const long ProtocolVersion = 1204;
 const long MinCompatProtocol = 1201;
 
 /** Forward declarations

src/modules/m_spanningtree/metadata.cpp

@@ -27,27 +27,66 @@
 
 CmdResult CommandMetadata::Handle(const std::vector<std::string>& params, User *srcuser)
 {
-	std::string value = params.size() < 3 ? "" : params[2];
-	ExtensionItem* item = ServerInstance->Extensions.GetItem(params[1]);
 	if (params[0] == "*")
 	{
+		std::string value = params.size() < 3 ? "" : params[2];
 		FOREACH_MOD(I_OnDecodeMetaData,OnDecodeMetaData(NULL,params[1],value));
 	}
 	else if (*(params[0].c_str()) == '#')
 	{
 		Channel* c = ServerInstance->FindChan(params[0]);
 		if (c)
 		{
+			/*
+			 * Since protocol version 1204 we have the channel TS in METADATA concerning channels and
+			 * we only accept them if the timestamps match. Previous versions don't send a timestamp
+			 * so we need to fall back to the old behaviour and accept what they sent.
+			 *
+			 * Pre-1204:       :sid METADATA #chan metaname :value
+			 * 1204 and later: :sid METADATA #chan chants metaname :value
+			 *
+			 */
+
+			// Determine the protocol version of the sender
+			SpanningTreeUtilities* Utils = ((ModuleSpanningTree*) (Module*) creator)->Utils;
+			TreeServer* srcserver = Utils->FindServer(srcuser->server);
+			if (!srcserver)
+			{
+				// Illegal prefix in METADATA
+				return CMD_FAILURE;
+			}
+
+			bool has_ts = (srcserver->Socket->proto_version >= 1204);
+
+			// If we got a channel TS compare it with ours. If it's different, drop the command.
+			// Also drop the command if we are using 1204, but there aren't enough parameters.
+			if ((has_ts) && ((ConvToInt(params[1]) != c->age) || params.size() < 3))
+				return CMD_FAILURE;
+
+			// Now do things as usual but if required, apply an offset to the index when accessing params
+			unsigned int indexoffset = has_ts ? 1 : 0;
+
+			std::string value = params.size() < (3+indexoffset) ? "" : params[2+indexoffset];
+			ExtensionItem* item = ServerInstance->Extensions.GetItem(params[1+indexoffset]);
 			if (item)
 				item->unserialize(FORMAT_NETWORK, c, value);
-			FOREACH_MOD(I_OnDecodeMetaData,OnDecodeMetaData(c,params[1],value));
+			FOREACH_MOD(I_OnDecodeMetaData,OnDecodeMetaData(c,params[1+indexoffset],value));
+
+			// Finally,	if they haven't sent us a channel TS add ours before passing the command on
+			if (!has_ts)
+			{
+				parameterlist& p = const_cast<parameterlist&>(params);
+				p.insert(p.begin()+1, ConvToStr(c->age));
+			}
 		}
 	}
 	else if (*(params[0].c_str()) != '#')
 	{
 		User* u = ServerInstance->FindNick(params[0]);
 		if (u)
 		{
+			std::string value = params.size() < 3 ? "" : params[2];
+			ExtensionItem* item = ServerInstance->Extensions.GetItem(params[1]);
 			if (item)
 				item->unserialize(FORMAT_NETWORK, u, value);
 			FOREACH_MOD(I_OnDecodeMetaData,OnDecodeMetaData(u,params[1],value));

src/modules/m_spanningtree/netburst.cpp

@@ -156,7 +156,7 @@ void TreeSocket::SendFJoins(Channel* c)
 
 	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());
+		snprintf(list,MAXBUF,":%s FTOPIC %s %lu %lu %s :%s", ServerInstance->Config->GetSID().c_str(), c->name.c_str(), (unsigned long) c->age, (unsigned long) c->topicset, c->setby.c_str(), c->topic.c_str());
 		WriteLine(list);
 	}
 

src/modules/m_spanningtree/protocolinterface.cpp

@@ -36,7 +36,7 @@ void SpanningTreeSyncTarget::SendMetaData(Extensible* target, const std::string
 	if (u)
 		ts.WriteLine(std::string(":")+ServerInstance->Config->GetSID()+" METADATA "+u->uuid+" "+extname+" :"+extdata);
 	else if (c)
-		ts.WriteLine(std::string(":")+ServerInstance->Config->GetSID()+" METADATA "+c->name+" "+extname+" :"+extdata);
+		ts.WriteLine(std::string(":")+ServerInstance->Config->GetSID()+" METADATA "+c->name+" "+ConvToStr(c->age)+" "+extname+" :"+extdata);
 	else if (!target)
 		ts.WriteLine(std::string(":")+ServerInstance->Config->GetSID()+" METADATA * "+extname+" :"+extdata);
 }
@@ -94,7 +94,10 @@ void SpanningTreeProtocolInterface::SendMetaData(Extensible* target, const std::
 	if (u)
 		params.push_back(u->uuid);
 	else if (c)
+	{
 		params.push_back(c->name);
+		params.push_back(ConvToStr(c->age));
+	}
 	else
 		params.push_back("*");
 
@@ -109,6 +112,7 @@ void SpanningTreeProtocolInterface::SendTopic(Channel* channel, std::string &top
 	parameterlist params;
 
 	params.push_back(channel->name);
+	params.push_back(ConvToStr(channel->age));
 	params.push_back(ConvToStr(ServerInstance->Time()));
 	params.push_back(ServerInstance->Config->ServerName);
 	params.push_back(":" + topic);