Shuffle the modules about a bit.

1 files changed, 458 insertions, 0 deletions

diff --git a/modules/spanningtree/treesocket2.cpp b/modules/spanningtree/treesocket2.cpp
new file mode 100644
index 000000000..eae8cbe21
--- /dev/null
+++ b/modules/spanningtree/treesocket2.cpp
@@ -0,0 +1,458 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
+ *   Copyright (C) 2018-2024 Sadie Powell <sadie@witchery.services>
+ *   Copyright (C) 2012-2016, 2018 Attila Molnar <attilamolnar@hush.com>
+ *   Copyright (C) 2012 Robby <robby@chatbelgie.be>
+ *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
+ *   Copyright (C) 2008, 2012 Robin Burchell <robin+git@viroteck.net>
+ *   Copyright (C) 2007-2008 Dennis Friis <peavey@inspircd.org>
+ *   Copyright (C) 2007-2008 Craig Edwards <brain@inspircd.org>
+ *
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "inspircd.h"
+#include "timeutils.h"
+
+#include "main.h"
+#include "utils.h"
+#include "treeserver.h"
+#include "treesocket.h"
+#include "resolvers.h"
+#include "commands.h"
+
+/* Handle ERROR command */
+void TreeSocket::Error(CommandBase::Params& params)
+{
+	const std::string msg = params.empty() ? "" : params[0];
+	SetError("received ERROR " + msg);
+}
+
+void TreeSocket::Split(const std::string& line, std::string& tags, std::string& prefix, std::string& command, CommandBase::Params& params)
+{
+	std::string token;
+	irc::tokenstream tokens(line);
+
+	if (!tokens.GetMiddle(token))
+		return;
+
+	if (token[0] == '@')
+	{
+		if (token.length() <= 1)
+		{
+			this->SendError("BUG: Received a message with empty tags: " + line);
+			return;
+		}
+
+		tags.assign(token, 1, std::string::npos);
+		if (!tokens.GetMiddle(token))
+		{
+			this->SendError("BUG: Received a message with no command: " + line);
+			return;
+		}
+	}
+
+	if (token[0] == ':')
+	{
+		if (token.length() <= 1)
+		{
+			this->SendError("BUG: Received a message with an empty prefix: " + line);
+			return;
+		}
+
+		prefix.assign(token, 1, std::string::npos);
+		if (!tokens.GetMiddle(token))
+		{
+			this->SendError("BUG: Received a message with no command: " + line);
+			return;
+		}
+	}
+
+	command.assign(token);
+	while (tokens.GetTrailing(token))
+		params.push_back(token);
+}
+
+void TreeSocket::ProcessLine(std::string& line)
+{
+	std::string tags;
+	std::string prefix;
+	std::string command;
+	CommandBase::Params params;
+
+	ServerInstance->Logs.RawIO(MODNAME, "S[{}] I {}", GetFd(), line);
+
+	Split(line, tags, prefix, command, params);
+
+	if (command.empty())
+		return;
+
+	switch (this->LinkState)
+	{
+		case WAIT_AUTH_1:
+			/*
+			 * State WAIT_AUTH_1:
+			 *  Waiting for SERVER command from remote server. Server initiating
+			 *  the connection sends the first SERVER command, listening server
+			 *  replies with theirs if its happy, then if the initiator is happy,
+			 *  it starts to send its net sync, which starts the merge, otherwise
+			 *  it sends an ERROR.
+			 */
+			if (command == "PASS")
+			{
+				/*
+				 * Ignore this silently. Some services packages insist on sending PASS, even
+				 * when it is not required (i.e. by us). We have to ignore this here, otherwise
+				 * as it's an unknown command (effectively), it will cause the connection to be
+				 * closed, which probably isn't what people want. -- w00t
+				 */
+			}
+			else if (command == "SERVER")
+			{
+				this->Inbound_Server(params);
+			}
+			else if (command == "ERROR")
+			{
+				this->Error(params);
+			}
+			else if (command == "USER")
+			{
+				this->SendError("Client connections to this port are prohibited.");
+			}
+			else if (command == "CAPAB")
+			{
+				this->Capab(params);
+			}
+			else
+			{
+				this->SendError("Invalid command in negotiation phase: " + command);
+			}
+		break;
+		case WAIT_AUTH_2:
+			/*
+			 * State WAIT_AUTH_2:
+			 *  We have sent SERVER to the other side of the connection. Now we're waiting for them to start BURST.
+			 *  The other option at this stage of things, of course, is for them to close our connection thanks
+			 *  to invalid credentials.. -- w
+			 */
+			if (command == "SERVER")
+			{
+				/*
+				 * Connection is either attempting to re-auth itself (stupid) or sending netburst without sending BURST.
+				 * Both of these aren't allowable, so block them here. -- w
+				 */
+				this->SendError("You may not re-authenticate or commence netburst without sending BURST.");
+			}
+			else if (command == "BURST")
+			{
+				if (!params.empty())
+				{
+					time_t them = ServerCommand::ExtractTS(params[0]);
+					time_t delta = them - ServerInstance->Time();
+					if ((delta < -15) || (delta > 15))
+					{
+						ServerInstance->SNO.WriteGlobalSno('l', "\002ERROR\002: Your clocks are off by {} seconds (this is more than fifteen seconds). Link aborted, \002PLEASE SYNC YOUR CLOCKS!\002", labs((long)delta));
+						SendError("Your clocks are out by "+ConvToStr(labs((long)delta))+" seconds (this is more than fifteen seconds). Link aborted, PLEASE SYNC YOUR CLOCKS!");
+						return;
+					}
+					else if ((delta < -5) || (delta > 5))
+					{
+						ServerInstance->SNO.WriteGlobalSno('l', "\002WARNING\002: Your clocks are off by {} seconds. Please consider syncing your clocks.", labs((long)delta));
+					}
+				}
+
+				// Check for duplicate server name/sid again, it's possible that a new
+				// server was introduced while we were waiting for them to send BURST.
+				// (we do not reserve their server name/sid when they send SERVER, we do it now)
+				if (!CheckDuplicate(capab->name, capab->sid))
+					return;
+
+				FinishAuth(capab->name, capab->sid, capab->description, capab->hidden);
+			}
+			else if (command == "ERROR")
+			{
+				this->Error(params);
+			}
+			else if (command == "CAPAB")
+			{
+				this->Capab(params);
+			}
+			else
+			{
+				ServerInstance->Logs.Debug(MODNAME, "Unknown command from fd {} in the WAIT_AUTH_2 phase: {}",
+					GetFd(), command);
+			}
+
+		break;
+		case CONNECTING:
+			/*
+			 * State CONNECTING:
+			 *  We're connecting (OUTGOING) to another server. They are in state WAIT_AUTH_1 until they verify
+			 *  our credentials, when they proceed into WAIT_AUTH_2 and send SERVER to us. We then send BURST
+			 *  + our netburst, which will put them into CONNECTED state. -- w
+			 */
+			if (command == "SERVER")
+			{
+				// Our credentials have been accepted, send netburst. (this puts US into the CONNECTED state)
+				this->Outbound_Reply_Server(params);
+			}
+			else if (command == "ERROR")
+			{
+				this->Error(params);
+			}
+			else if (command == "CAPAB")
+			{
+				this->Capab(params);
+			}
+			else
+			{
+				ServerInstance->Logs.Debug(MODNAME, "Unknown command from fd {} in the CONNECTING phase: {}",
+					GetFd(), command);
+			}
+		break;
+
+		case CONNECTED:
+			/*
+			 * State CONNECTED:
+			 *  Credentials have been exchanged, we've gotten their 'BURST' (or sent ours).
+			 *  Anything from here on should be accepted a little more reasonably.
+			 */
+			this->ProcessConnectedLine(tags, prefix, command, params);
+		break;
+
+		case DYING:
+		break;
+	}
+}
+
+User* TreeSocket::FindSource(const std::string& prefix, const std::string& command)
+{
+	// Empty prefix means the source is the directly connected server that sent this command
+	if (prefix.empty())
+		return MyRoot->ServerUser;
+
+	if (prefix.size() == 3)
+	{
+		// Prefix looks like a sid
+		TreeServer* server = Utils->FindServerID(prefix);
+		if (server)
+			return server->ServerUser;
+	}
+	else
+	{
+		// If the prefix string is a uuid FindUUID() returns the appropriate User object
+		auto* user = ServerInstance->Users.FindUUID(prefix);
+		if (user)
+			return user;
+	}
+
+	// Some implementations wrongly send a server name as prefix occasionally, handle that too for now
+	TreeServer* const server = Utils->FindServer(prefix);
+	if (server)
+		return server->ServerUser;
+
+	/* It is important that we don't close the link here, unknown prefix can occur
+	 * due to various race conditions such as the KILL message for a user somehow
+	 * crossing the users QUIT further upstream from the server. Thanks jilles!
+	 */
+
+	if ((prefix.length() == UIDGenerator::UUID_LENGTH) && (isdigit(prefix[0])) &&
+		((command == "FMODE") || (command == "MODE") || (command == "KICK") || (command == "TOPIC") || (command == "KILL") || (command == "ADDLINE") || (command == "DELLINE")))
+	{
+		/* Special case, we cannot drop these commands as they've been committed already on a
+		 * part of the network by the time we receive them, so in this scenario pretend the
+		 * command came from a server to avoid desync.
+		 */
+
+		TreeServer* const usersserver = Utils->FindServerID(prefix.substr(0, 3));
+		if (usersserver)
+			return usersserver->ServerUser;
+		return this->MyRoot->ServerUser;
+	}
+
+	// Unknown prefix
+	return nullptr;
+}
+
+void TreeSocket::ProcessTag(User* source, const std::string& tag, ClientProtocol::TagMap& tags)
+{
+	std::string tagkey;
+	std::string tagval;
+	const std::string::size_type p = tag.find('=');
+	if (p != std::string::npos)
+	{
+		// Tag has a value
+		tagkey.assign(tag, 0, p);
+		tagval.assign(tag, p + 1, std::string::npos);
+	}
+	else
+	{
+		tagkey.assign(tag);
+	}
+
+	for (auto* subscriber : Utils->Creator->tagevprov.GetSubscribers())
+	{
+		ClientProtocol::MessageTagProvider* const tagprov = static_cast<ClientProtocol::MessageTagProvider*>(subscriber);
+		const ModResult res = tagprov->OnProcessTag(source, tagkey, tagval);
+		if (res == MOD_RES_ALLOW)
+			tags.emplace(tagkey, ClientProtocol::MessageTagData(tagprov, tagval));
+		else if (res == MOD_RES_DENY)
+			break;
+	}
+}
+
+void TreeSocket::ProcessConnectedLine(std::string& taglist, std::string& prefix, std::string& command, CommandBase::Params& params)
+{
+	User* who = FindSource(prefix, command);
+	if (!who)
+	{
+		ServerInstance->Logs.Debug(MODNAME, "Command '{}' from unknown prefix '{}'! Dropping entire command.", command, prefix);
+		return;
+	}
+
+	/*
+	 * Check for fake direction here, and drop any instances that are found.
+	 * What is fake direction? Imagine the following server setup:
+	 *    0AA <-> 0AB <-> 0AC
+	 * Fake direction would be 0AC sending a message to 0AB claiming to be from
+	 * 0AA, or something similar. Basically, a message taking a path that *cannot*
+	 * be correct.
+	 *
+	 * When would this be seen?
+	 * Well, hopefully never. It could be caused by race conditions, bugs, or
+	 * "miscreant" servers, though, so let's check anyway. -- w
+	 *
+	 * We also check here for totally invalid prefixes (prefixes that are neither
+	 * a valid SID or a valid UUID, so that invalid UUID or SID never makes it
+	 * to the higher level functions. -- B
+	 */
+	TreeServer* const server = TreeServer::Get(who);
+	if (server->GetSocket() != this)
+	{
+		ServerInstance->Logs.Debug(MODNAME, "Protocol violation: Fake direction '{}' from connection '{}'", prefix, linkID);
+		return;
+	}
+
+	// Translate commands coming from servers using an older protocol
+	if (proto_version < PROTO_NEWEST)
+	{
+		if (!PreProcessOldProtocolMessage(who, command, params))
+			return;
+	}
+
+	ServerCommand* scmd = Utils->Creator->CmdManager.GetHandler(command);
+	CommandBase* cmdbase = scmd;
+	Command* cmd = nullptr;
+	if (!scmd)
+	{
+		// Not a special server-to-server command
+		cmd = ServerInstance->Parser.GetHandler(command);
+		if (!cmd)
+		{
+			if (command == "ERROR")
+			{
+				this->Error(params);
+				return;
+			}
+			else if (command == "BURST")
+			{
+				// This is sent even when there is no need for it, drop it here for now
+				return;
+			}
+
+			throw ProtocolException("Unknown command: " + command);
+		}
+		cmdbase = cmd;
+	}
+
+	if (params.size() < cmdbase->min_params)
+		throw ProtocolException("Insufficient parameters");
+
+	if ((!params.empty()) && (params.back().empty()) && (!cmdbase->allow_empty_last_param))
+	{
+		// the last param is empty and the command handler doesn't allow that, check if there will be enough params if we drop the last
+		if (params.size()-1 < cmdbase->min_params)
+			return;
+		params.pop_back();
+	}
+
+	CmdResult res;
+	ClientProtocol::TagMap tags;
+	std::string tag;
+	irc::sepstream tagstream(taglist, ';');
+	while (tagstream.GetToken(tag))
+		ProcessTag(who, tag, tags);
+
+	CommandBase::Params newparams(params, tags);
+
+	if (scmd)
+		res = scmd->Handle(who, newparams);
+	else
+	{
+		res = cmd->Handle(who, newparams);
+		if (res == CmdResult::INVALID)
+			throw ProtocolException("Error in command handler");
+	}
+
+	if (res == CmdResult::SUCCESS)
+		Utils->RouteCommand(server->GetRoute(), cmdbase, newparams, who);
+}
+
+void TreeSocket::OnTimeout()
+{
+	ServerInstance->SNO.WriteGlobalSno('l', "CONNECT: Connection to \002{}\002 timed out.", linkID);
+}
+
+void TreeSocket::Close()
+{
+	if (!HasFd())
+		return;
+
+	ServerInstance->GlobalCulls.AddItem(this);
+	this->BufferedSocket::Close();
+	SetError("Remote host closed connection");
+
+	// Connection closed.
+	// If the connection is fully up (state CONNECTED)
+	// then propagate a netsplit to all peers.
+	if (MyRoot && !MyRoot->IsDead())
+		MyRoot->SQuit(GetError(), true);
+	else
+		ServerInstance->SNO.WriteGlobalSno('l', "Connection to '\002{}\002' failed.", linkID);
+
+	time_t server_uptime = ServerInstance->Time() - this->age;
+	if (server_uptime)
+	{
+		std::string timestr = Duration::ToString(server_uptime);
+		ServerInstance->SNO.WriteGlobalSno('l', "Connection to '\002{}\002' was established for {}", linkID, timestr);
+	}
+}
+
+void TreeSocket::FinishAuth(const std::string& remotename, const std::string& remotesid, const std::string& remotedesc, bool hidden)
+{
+	this->LinkState = CONNECTED;
+	Utils->timeoutlist.erase(this);
+
+	linkID = remotename;
+
+	MyRoot = new TreeServer(remotename, remotedesc, remotesid, Utils->TreeRoot, this, hidden);
+
+	// Mark the server as bursting
+	MyRoot->BeginBurst();
+	this->DoBurst(MyRoot);
+
+	CommandServer::Builder(MyRoot).Forward(MyRoot);
+}