Shuffle the modules about a bit.

1 files changed, 923 insertions, 0 deletions

diff --git a/modules/spanningtree/main.cpp b/modules/spanningtree/main.cpp
new file mode 100644
index 000000000..f0560123a
--- /dev/null
+++ b/modules/spanningtree/main.cpp
@@ -0,0 +1,923 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2020 Matt Schatz <genius3000@g3k.solutions>
+ *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
+ *   Copyright (C) 2013, 2017-2024 Sadie Powell <sadie@witchery.services>
+ *   Copyright (C) 2013, 2016 Adam <Adam@anope.org>
+ *   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) 2007-2009 Robin Burchell <robin+git@viroteck.net>
+ *   Copyright (C) 2007-2008 Dennis Friis <peavey@inspircd.org>
+ *   Copyright (C) 2005, 2007-2009 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 "clientprotocolmsg.h"
+#include "iohook.h"
+#include "socket.h"
+#include "xline.h"
+
+#include "commands.h"
+#include "link.h"
+#include "main.h"
+#include "resolvers.h"
+#include "translate.h"
+#include "treeserver.h"
+#include "treesocket.h"
+#include "utils.h"
+
+ModuleSpanningTree::ModuleSpanningTree()
+	: Module(VF_VENDOR, "Allows linking multiple servers together as part of one network.")
+	, Away::EventListener(this)
+	, Stats::EventListener(this)
+	, CTCTags::EventListener(this)
+	, rconnect(this)
+	, rsquit(this)
+	, map(this)
+	, commands(this)
+	, routeeventprov(this, "event/server-route")
+	, linkeventprov(this, "event/server-link")
+	, messageeventprov(this, "event/server-message")
+	, synceventprov(this, "event/server-sync")
+	, sslapi(this)
+	, servertags(this)
+	, DNS(this)
+	, tagevprov(this)
+{
+}
+
+SpanningTreeCommands::SpanningTreeCommands(ModuleSpanningTree* module)
+	: metadata(module)
+	, uid(module)
+	, opertype(module)
+	, fjoin(module)
+	, ijoin(module)
+	, resync(module)
+	, fmode(module)
+	, ftopic(module)
+	, fhost(module)
+	, frhost(module)
+	, fident(module)
+	, fname(module)
+	, away(module)
+	, addline(module)
+	, delline(module)
+	, encap(module)
+	, idle(module)
+	, nick(module)
+	, ping(module)
+	, pong(module)
+	, save(module)
+	, server(module)
+	, squit(module)
+	, snonotice(module)
+	, endburst(module)
+	, sinfo(module)
+	, num(module)
+	, lmode(module)
+{
+}
+
+namespace
+{
+	void SetLocalUsersServer(Server* newserver)
+	{
+		// Does not change the server of quitting users because those are not in the list
+
+		ServerInstance->FakeClient->server = newserver;
+		for (auto* user : ServerInstance->Users.GetLocalUsers())
+			user->server = newserver;
+	}
+
+	void ResetMembershipIds()
+	{
+		// Set all membership ids to 0
+		for (const auto* user : ServerInstance->Users.GetLocalUsers())
+		{
+			for (auto* memb : user->chans)
+				memb->id = 0;
+		}
+	}
+}
+
+void ModuleSpanningTree::init()
+{
+	ServerInstance->SNO.EnableSnomask('l', "LINK");
+
+	ResetMembershipIds();
+
+	Utils = new SpanningTreeUtilities(this);
+	Utils->TreeRoot = new TreeServer;
+
+	ServerInstance->PI = &protocolinterface;
+
+	delete ServerInstance->FakeClient->server;
+	SetLocalUsersServer(Utils->TreeRoot);
+}
+
+void ModuleSpanningTree::ShowLinks(TreeServer* Current, User* user, int hops)
+{
+	std::string Parent = Utils->TreeRoot->GetName();
+	if (Current->GetParent())
+	{
+		Parent = Current->GetParent()->GetName();
+	}
+
+	for (auto* server : Current->GetChildren())
+	{
+		if ((server->Hidden) || ((Utils->HideServices) && (server->IsService())))
+		{
+			if (user->IsOper())
+			{
+				ShowLinks(server, user, hops+1);
+			}
+		}
+		else
+		{
+			ShowLinks(server, user, hops+1);
+		}
+	}
+	/* Don't display the line if its a service, hide services is on, and the user isn't an oper */
+	if ((Utils->HideServices) && (Current->IsService()) && (!user->IsOper()))
+		return;
+	/* Or if the server is hidden and they're not an oper */
+	else if ((Current->Hidden) && (!user->IsOper()))
+		return;
+
+	user->WriteNumeric(RPL_LINKS, Current->GetName(),
+			(((Utils->FlatLinks) && (!user->IsOper())) ? ServerInstance->Config->GetServerName() : Parent),
+			fmt::format("{} {}", (((Utils->FlatLinks) && (!user->IsOper())) ? 0 : hops), Current->GetDesc()));
+}
+
+void ModuleSpanningTree::HandleLinks(const CommandBase::Params& parameters, User* user)
+{
+	ShowLinks(Utils->TreeRoot, user, 0);
+	user->WriteNumeric(RPL_ENDOFLINKS, '*', "End of /LINKS list.");
+}
+
+void ModuleSpanningTree::ConnectServer(const std::shared_ptr<Autoconnect>& a, bool on_timer)
+{
+	if (!a)
+		return;
+	for(unsigned int j=0; j < a->servers.size(); j++)
+	{
+		if (Utils->FindServer(a->servers[j]))
+		{
+			// found something in this block. Should the server fail,
+			// we want to start at the start of the list, not in the
+			// middle where we left off
+			a->position = -1;
+			return;
+		}
+	}
+	if (on_timer && a->position >= 0)
+		return;
+	if (!on_timer && a->position < 0)
+		return;
+
+	a->position++;
+	while (a->position < (int)a->servers.size())
+	{
+		std::shared_ptr<Link> x = Utils->FindLink(a->servers[a->position]);
+		if (x)
+		{
+			ServerInstance->SNO.WriteToSnoMask('l', "AUTOCONNECT: Auto-connecting server \002{}\002", x->Name);
+			ConnectServer(x, a);
+			return;
+		}
+		a->position++;
+	}
+	// Autoconnect chain has been fully iterated; start at the beginning on the
+	// next AutoConnectServers run
+	a->position = -1;
+}
+
+void ModuleSpanningTree::ConnectServer(const std::shared_ptr<Link>& x, const std::shared_ptr<Autoconnect>& y)
+{
+	if (InspIRCd::Match(ServerInstance->Config->ServerName, x->Name, ascii_case_insensitive_map))
+	{
+		ServerInstance->SNO.WriteToSnoMask('l', "CONNECT: Not connecting to myself.");
+		return;
+	}
+
+	irc::sockets::sockaddrs sa;
+	if (x->IPAddr.find('/') != std::string::npos)
+	{
+		if (!irc::sockets::isunix(x->IPAddr) || !sa.from_unix(x->IPAddr))
+		{
+			// We don't use the family() != AF_UNSPEC check below for UNIX sockets as
+			// that results in a DNS lookup.
+			ServerInstance->SNO.WriteToSnoMask('l', "CONNECT: Error connecting \002{}\002: {} is not a UNIX socket!",
+				x->Name, x->IPAddr);
+			return;
+		}
+	}
+	else
+	{
+		// If this fails then the IP sa will be AF_UNSPEC.
+		sa.from_ip_port(x->IPAddr, x->Port);
+	}
+
+	/* Do we already have an IP? If so, no need to resolve it. */
+	if (sa.family() != AF_UNSPEC)
+	{
+		// Create a TreeServer object that will start connecting immediately in the background
+		auto* newsocket = new TreeSocket(x, y, sa);
+		if (!newsocket->HasFd())
+		{
+			ServerInstance->SNO.WriteToSnoMask('l', "CONNECT: Error connecting \002{}\002: {}.",
+				x->Name, newsocket->GetError());
+			ServerInstance->GlobalCulls.AddItem(newsocket);
+		}
+	}
+	else if (!DNS)
+	{
+		ServerInstance->SNO.WriteToSnoMask('l', "CONNECT: Error connecting \002{}\002: Hostname given and core_dns is not loaded, unable to resolve.", x->Name);
+	}
+	else
+	{
+		// Guess start_type from bindip aftype
+		DNS::QueryType start_type = DNS::QUERY_AAAA;
+		irc::sockets::sockaddrs bind;
+		if (!x->Bind.empty() && bind.from_ip(x->Bind))
+		{
+			if (bind.family() == AF_INET)
+				start_type = DNS::QUERY_A;
+		}
+
+		auto* snr = new ServerNameResolver(*DNS, x->IPAddr, x, start_type, y);
+		try
+		{
+			DNS->Process(snr);
+		}
+		catch (const DNS::Exception& e)
+		{
+			delete snr;
+			ServerInstance->SNO.WriteToSnoMask('l', "CONNECT: Error connecting \002{}\002: {}.", x->Name, e.GetReason());
+			ConnectServer(y, false);
+		}
+	}
+}
+
+void ModuleSpanningTree::AutoConnectServers(time_t curtime)
+{
+	for (const auto& x : Utils->AutoconnectBlocks)
+	{
+		if (curtime >= x->NextConnectTime)
+		{
+			x->NextConnectTime = curtime + x->Period;
+			ConnectServer(x, true);
+		}
+	}
+}
+
+void ModuleSpanningTree::DoConnectTimeout(time_t curtime)
+{
+	SpanningTreeUtilities::TimeoutList::iterator i = Utils->timeoutlist.begin();
+	while (i != Utils->timeoutlist.end())
+	{
+		TreeSocket* s = i->first;
+		std::pair<std::string, unsigned int> p = i->second;
+		SpanningTreeUtilities::TimeoutList::iterator me = i;
+		i++;
+		if (s->GetLinkState() == DYING)
+		{
+			Utils->timeoutlist.erase(me);
+			s->Close();
+		}
+		else if (curtime > s->age + (time_t)p.second)
+		{
+			ServerInstance->SNO.WriteToSnoMask('l', "CONNECT: Error connecting \002{}\002 (timeout of {} seconds)", p.first, p.second);
+			Utils->timeoutlist.erase(me);
+			s->Close();
+		}
+	}
+}
+
+ModResult ModuleSpanningTree::HandleVersion(const CommandBase::Params& parameters, User* user)
+{
+	// We've already confirmed that !parameters.empty(), so this is safe
+	TreeServer* found = Utils->FindServerMask(parameters[0]);
+	if (found)
+	{
+		if (found == Utils->TreeRoot)
+		{
+			// Pass to default VERSION handler.
+			return MOD_RES_PASSTHRU;
+		}
+
+		Numeric::Numeric numeric(RPL_VERSION);
+		if (user->IsOper())
+		{
+			numeric.push(found->rawversion + ".");
+			numeric.push(found->GetName());
+			numeric.push("[" + found->GetId() + "] " + found->customversion);
+		}
+		else
+		{
+			numeric.push(found->rawbranch + ".");
+			numeric.push(found->GetPublicName());
+			numeric.push(found->customversion);
+		}
+		user->WriteNumeric(numeric);
+	}
+	else
+	{
+		user->WriteNumeric(ERR_NOSUCHSERVER, parameters[0], "No such server");
+	}
+	return MOD_RES_DENY;
+}
+
+ModResult ModuleSpanningTree::HandleConnect(const CommandBase::Params& parameters, User* user)
+{
+	for (const auto& x : Utils->LinkBlocks)
+	{
+		if (InspIRCd::Match(x->Name, parameters[0], ascii_case_insensitive_map))
+		{
+			if (InspIRCd::Match(ServerInstance->Config->ServerName, x->Name, ascii_case_insensitive_map))
+			{
+				user->WriteRemoteNotice(fmt::format("*** CONNECT: Server \002{}\002 is ME, not connecting.", x->Name));
+				return MOD_RES_DENY;
+			}
+
+			TreeServer* CheckDupe = Utils->FindServer(x->Name);
+			if (!CheckDupe)
+			{
+				user->WriteRemoteNotice(fmt::format("*** CONNECT: Connecting to server: \002{}\002 ({}:{})", x->Name, (x->HiddenFromStats ? "<hidden>" : x->IPAddr), x->Port));
+				ConnectServer(x);
+				return MOD_RES_DENY;
+			}
+			else
+			{
+				user->WriteRemoteNotice(fmt::format("*** CONNECT: Server \002{}\002 already exists on the network and is connected via \002{}\002", x->Name, CheckDupe->GetParent()->GetName()));
+				return MOD_RES_DENY;
+			}
+		}
+	}
+	user->WriteRemoteNotice(fmt::format("*** CONNECT: No server matching \002{}\002 could be found in the config file.", parameters[0]));
+	return MOD_RES_DENY;
+}
+
+void ModuleSpanningTree::OnUserInvite(User* source, User* dest, Channel* channel, time_t expiry, ModeHandler::Rank notifyrank, CUList& notifyexcepts)
+{
+	if (IS_LOCAL(source))
+	{
+		CmdBuilder params(source, "INVITE");
+		params.push(dest->uuid);
+		params.push(channel->name);
+		params.push_int(channel->age);
+		params.push(ConvToStr(expiry));
+		params.Broadcast();
+	}
+}
+
+ModResult ModuleSpanningTree::OnPreTopicChange(User* user, Channel* chan, const std::string& topic)
+{
+	// XXX: Deny topic changes if the current topic set time is the current time or is in the future because
+	// other servers will drop our FTOPIC. This restriction will be removed when the protocol is updated.
+	if ((chan->topicset >= ServerInstance->Time()) && (Utils->serverlist.size() > 1))
+	{
+		user->WriteNumeric(ERR_UNAVAILRESOURCE, chan->name, "Retry topic change later");
+		return MOD_RES_DENY;
+	}
+	return MOD_RES_PASSTHRU;
+}
+
+void ModuleSpanningTree::OnPostTopicChange(User* user, Channel* chan, const std::string& topic)
+{
+	// Drop remote events on the floor.
+	if (!IS_LOCAL(user))
+		return;
+
+	CommandFTopic::Builder(user, chan).Broadcast();
+}
+
+void ModuleSpanningTree::OnUserPostMessage(User* user, const MessageTarget& target, const MessageDetails& details)
+{
+	if (!IS_LOCAL(user))
+		return;
+
+	const char* message_type = (details.type == MessageType::PRIVMSG ? "PRIVMSG" : "NOTICE");
+	switch (target.type)
+	{
+		case MessageTarget::TYPE_USER:
+		{
+			auto* d = target.Get<User>();
+			if (!IS_LOCAL(d))
+			{
+				CmdBuilder params(user, message_type);
+				params.push_tags(details.tags_out);
+				params.push(d->uuid);
+				params.push_last(details.text);
+				params.Unicast(d);
+			}
+			break;
+		}
+		case MessageTarget::TYPE_CHANNEL:
+		{
+			Utils->SendChannelMessage(user, target.Get<Channel>(), details.text, target.status, details.tags_out, details.exemptions, message_type);
+			break;
+		}
+		case MessageTarget::TYPE_SERVER:
+		{
+			const auto* serverglob = target.Get<std::string>();
+			CmdBuilder par(user, message_type);
+			par.push_tags(details.tags_out);
+			par.push(std::string("$") + *serverglob);
+			par.push_last(details.text);
+			par.Broadcast();
+			break;
+		}
+	}
+}
+
+void ModuleSpanningTree::OnUserPostTagMessage(User* user, const MessageTarget& target, const CTCTags::TagMessageDetails& details)
+{
+	if (!IS_LOCAL(user))
+		return;
+
+	switch (target.type)
+	{
+		case MessageTarget::TYPE_USER:
+		{
+			auto* d = target.Get<User>();
+			if (!IS_LOCAL(d))
+			{
+				CmdBuilder params(user, "TAGMSG");
+				params.push_tags(details.tags_out);
+				params.push(d->uuid);
+				params.Unicast(d);
+			}
+			break;
+		}
+		case MessageTarget::TYPE_CHANNEL:
+		{
+			Utils->SendChannelMessage(user, target.Get<Channel>(), "", target.status, details.tags_out, details.exemptions, "TAGMSG");
+			break;
+		}
+		case MessageTarget::TYPE_SERVER:
+		{
+			const auto* serverglob = target.Get<std::string>();
+			CmdBuilder par(user, "TAGMSG");
+			par.push_tags(details.tags_out);
+			par.push(std::string("$") + *serverglob);
+			par.Broadcast();
+			break;
+		}
+	}
+}
+
+void ModuleSpanningTree::OnBackgroundTimer(time_t curtime)
+{
+	AutoConnectServers(curtime);
+	DoConnectTimeout(curtime);
+}
+
+void ModuleSpanningTree::OnUserConnect(LocalUser* user)
+{
+	if (user->quitting)
+		return;
+
+	// Create the lazy ssl_cert metadata for this user if not already created.
+	if (sslapi)
+		sslapi->GetCertificate(user);
+
+	CommandUID::Builder uid(user, true);
+	CommandUID::Builder olduid(user, false);
+
+	// NOTE: we can't do CommandUID::Builder(user).Broadcast() whilst
+	// we still support the 1205 protocol.
+	for (const auto* server : Utils->TreeRoot->GetChildren())
+	{
+		TreeSocket* socket = server->GetSocket();
+		if (!socket)
+			continue; // Should never happen?
+
+		if (socket->proto_version >= PROTO_INSPIRCD_4)
+			socket->WriteLine(uid);
+		else
+			socket->WriteLine(olduid);
+	}
+
+	if (user->IsOper())
+		CommandOpertype::Builder(user, user->oper).Broadcast();
+
+	if (user->IsAway())
+		CommandAway::Builder(user).Broadcast();
+
+	if (user->uniqueusername) // TODO: convert this to BooleanExtItem.
+		CommandMetadata::Builder(user, "uniqueusername", "1").Broadcast();
+
+	for (const auto& [item, obj] : user->GetExtList())
+	{
+		const std::string value = item->ToNetwork(user, obj);
+		if (!value.empty())
+			ServerInstance->PI->SendMetadata(user, item->name, value);
+	}
+
+	Utils->TreeRoot->UserCount++;
+}
+
+void ModuleSpanningTree::OnUserJoin(Membership* memb, bool sync, bool created_by_local, CUList& excepts)
+{
+	// Only do this for local users
+	if (!IS_LOCAL(memb->user))
+		return;
+
+	// Assign the current membership id to the new Membership and increase it
+	memb->id = currmembid++;
+
+	if (created_by_local)
+	{
+		CommandFJoin::Builder params(memb->chan);
+		params.add(memb);
+		params.finalize();
+		params.Broadcast();
+		SpanningTreeUtilities::SendListLimits(memb->chan, nullptr);
+	}
+	else
+	{
+		CmdBuilder params(memb->user, "IJOIN");
+		params.push(memb->chan->name);
+		params.push_int(memb->id);
+		if (!memb->modes.empty())
+		{
+			params.push(ConvToStr(memb->chan->age));
+			params.push(memb->GetAllPrefixModes());
+		}
+		params.Broadcast();
+	}
+}
+
+void ModuleSpanningTree::OnChangeHost(User* user, const std::string& newhost)
+{
+	if (!user->IsFullyConnected() || !IS_LOCAL(user))
+		return;
+
+	CmdBuilder(user, "FHOST").push(newhost).push('*').Broadcast();
+}
+
+void ModuleSpanningTree::OnChangeRealHost(User* user, const std::string& newhost)
+{
+	if (!user->IsFullyConnected() || !IS_LOCAL(user))
+		return;
+
+	CmdBuilder(user, "FHOST").push('*').push(newhost).Broadcast();
+}
+
+void ModuleSpanningTree::OnChangeRealName(User* user, const std::string& real)
+{
+	if (!user->IsFullyConnected() || !IS_LOCAL(user))
+		return;
+
+	CmdBuilder(user, "FNAME").push_last(real).Broadcast();
+}
+
+void ModuleSpanningTree::OnChangeUser(User* user, const std::string& newuser)
+{
+	if (!user->IsFullyConnected() || !IS_LOCAL(user))
+		return;
+
+	CmdBuilder(user, "FIDENT").push(newuser).push("*").Broadcast();
+}
+
+void ModuleSpanningTree::OnChangeRealUser(User* user, const std::string& newuser)
+{
+	if (!user->IsFullyConnected() || !IS_LOCAL(user))
+		return;
+
+	CmdBuilder(user, "FIDENT").push("*").push(newuser).Broadcast();
+}
+
+void ModuleSpanningTree::OnUserPart(Membership* memb, std::string& partmessage, CUList& excepts)
+{
+	if (IS_LOCAL(memb->user))
+	{
+		CmdBuilder params(memb->user, "PART");
+		params.push(memb->chan->name);
+		if (!partmessage.empty())
+			params.push_last(partmessage);
+		params.Broadcast();
+	}
+}
+
+void ModuleSpanningTree::OnUserQuit(User* user, const std::string& reason, const std::string& oper_message)
+{
+	if (IS_LOCAL(user))
+	{
+		if (oper_message != reason)
+			ServerInstance->PI->SendMetadata(user, "operquit", oper_message);
+
+		CmdBuilder(user, "QUIT").push_last(reason).Broadcast();
+	}
+	else
+	{
+		// Hide the message if one of the following is true:
+		// - User is being quit due to a netsplit and quietbursts is on
+		// - User is on a silent services server
+		TreeServer* server = TreeServer::Get(user);
+		bool hide = (((server->IsDead()) && (Utils->quiet_bursts)) || (server->IsSilentService()));
+		if (!hide)
+		{
+			ServerInstance->SNO.WriteToSnoMask('Q', "Client exiting on server {}: {} ({}) [{}]", user->server->GetName(),
+				user->GetRealMask(), user->GetAddress(), oper_message);
+		}
+	}
+
+	// Regardless, update the UserCount
+	TreeServer::Get(user)->UserCount--;
+}
+
+void ModuleSpanningTree::OnUserPostNick(User* user, const std::string& oldnick)
+{
+	if (IS_LOCAL(user))
+	{
+		// The nick TS is updated by the core, we don't do it
+		CmdBuilder params(user, "NICK");
+		params.push(user->nick);
+		params.push(ConvToStr(user->nickchanged));
+		params.Broadcast();
+	}
+	else if (!loopCall)
+	{
+		ServerInstance->Logs.Normal(MODNAME, "WARNING: Changed nick of remote user {} from {} to {} TS {} by ourselves!", user->uuid, oldnick, user->nick, user->nickchanged);
+	}
+}
+
+void ModuleSpanningTree::OnUserKick(User* source, Membership* memb, const std::string& reason, CUList& excepts)
+{
+	if ((!IS_LOCAL(source)) && (source != ServerInstance->FakeClient))
+		return;
+
+	CmdBuilder params(source, "KICK");
+	params.push(memb->chan->name);
+	params.push(memb->user->uuid);
+	// If a remote user is being kicked by us then send the membership id in the kick too
+	if (!IS_LOCAL(memb->user))
+		params.push_int(memb->id);
+	params.push_last(reason);
+	params.Broadcast();
+}
+
+void ModuleSpanningTree::OnPreRehash(User* user, const std::string& parameter)
+{
+	ServerInstance->Logs.Debug(MODNAME, "OnPreRehash called with param {}", parameter);
+
+	// Send out to other servers
+	if (!parameter.empty() && parameter[0] != '-')
+	{
+		CmdBuilder params(user ? user : ServerInstance->FakeClient, "REHASH");
+		params.push(parameter);
+		params.Forward(user ? TreeServer::Get(user)->GetRoute() : nullptr);
+	}
+}
+
+void ModuleSpanningTree::ReadConfig(ConfigStatus& status)
+{
+	// Did this rehash change the description of this server?
+	const std::string& newdesc = ServerInstance->Config->ServerDesc;
+	if (newdesc != Utils->TreeRoot->GetDesc())
+	{
+		// Broadcast a SINFO desc message to let the network know about the new description. This is the description
+		// string that is sent in the SERVER message initially and shown for example in WHOIS.
+		// We don't need to update the field itself in the Server object - the core does that.
+		CommandSInfo::Builder(Utils->TreeRoot, "desc", newdesc).Broadcast();
+	}
+
+	const auto& newcustomversion = ServerInstance->Config->CustomVersion;
+	if (newcustomversion != Utils->TreeRoot->customversion)
+	{
+		Utils->TreeRoot->customversion = newcustomversion;
+		CommandSInfo::Builder(Utils->TreeRoot, "customversion", newcustomversion).Broadcast();
+	}
+
+	// Re-read config stuff
+	try
+	{
+		Utils->ReadConfiguration();
+	}
+	catch (const ModuleException& e)
+	{
+		// Refresh the IP cache anyway, so servers read before the error will be allowed to connect
+		Utils->RefreshIPCache();
+		// Always warn local opers with snomask +l, also warn globally (snomask +L) if the rehash was issued by a remote user
+		std::string msg = "Error in configuration: ";
+		msg.append(e.GetReason());
+		ServerInstance->SNO.WriteToSnoMask('l', msg);
+		if (status.srcuser && !IS_LOCAL(status.srcuser))
+			ServerInstance->PI->SendSNONotice('L', msg);
+	}
+}
+
+namespace
+{
+	void BroadcastModuleState(Module* mod, bool loading)
+	{
+		std::stringstream buffer;
+		buffer << (loading ? '+' : '-') << ModuleManager::ShrinkModName(mod->ModuleFile);
+
+		std::stringstream compatbuffer;
+		compatbuffer << (loading ? '+' : '-') << mod->ModuleFile;
+
+		if (loading)
+		{
+			const std::string linkstring = SpanningTreeUtilities::BuildLinkString(PROTO_INSPIRCD_4, mod);
+			if (!linkstring.empty())
+				buffer << '=' << linkstring;
+
+			const std::string compatlinkstring = SpanningTreeUtilities::BuildLinkString(PROTO_INSPIRCD_3, mod);
+			if (!compatlinkstring.empty())
+				compatbuffer << '=' << compatlinkstring;
+		}
+
+		for (const auto* child : Utils->TreeRoot->GetChildren())
+		{
+			if (!child->GetSocket())
+				continue; // Should never happen?
+
+			if (child->GetSocket()->proto_version <= PROTO_INSPIRCD_3)
+				CommandMetadata::Builder("modules", buffer.str()).Forward(child);
+			else
+				CommandMetadata::Builder("modules", compatbuffer.str()).Forward(child);
+		}
+	}
+}
+
+void ModuleSpanningTree::OnLoadModule(Module* mod)
+{
+	BroadcastModuleState(mod, true);
+}
+
+void ModuleSpanningTree::OnUnloadModule(Module* mod)
+{
+	if (!Utils)
+		return;
+
+	BroadcastModuleState(mod, false);
+	if (mod == this)
+	{
+		// We are being unloaded, inform modules about all servers splitting which cannot be done later when the servers are actually disconnected
+		for (const auto& [_, server] : Utils->serverlist)
+		{
+			if (!server->IsRoot())
+				linkeventprov.Call(&ServerProtocol::LinkEventListener::OnServerSplit, server, false);
+		}
+		return;
+	}
+
+	// Some other module is being unloaded. If it provides an IOHook we use, we must close that server connection now.
+
+restart:
+	// Close all connections which use an IO hook provided by this module
+	for (const auto* child : Utils->TreeRoot->GetChildren())
+	{
+		TreeSocket* sock = child->GetSocket();
+		if (sock->GetModHook(mod))
+		{
+			sock->SendError("TLS module unloaded");
+			sock->Close();
+			// XXX: The list we're iterating is modified by TreeServer::SQuit() which is called by Close()
+			goto restart;
+		}
+	}
+
+	for (const auto& [sock, _] : Utils->timeoutlist)
+	{
+		if (sock->GetModHook(mod))
+			sock->Close();
+	}
+}
+
+void ModuleSpanningTree::OnOperLogin(User* user, const std::shared_ptr<OperAccount>& oper, bool automatic)
+{
+	if (!user->IsFullyConnected() || !IS_LOCAL(user))
+		return;
+
+	// Note: The protocol does not allow direct umode +o;
+	// sending OPERTYPE infers +o modechange locally.
+	CommandOpertype::Builder(user, oper, automatic).Broadcast();
+}
+
+void ModuleSpanningTree::OnAddLine(User* user, XLine* x)
+{
+	if (!x->IsBurstable() || loopCall || (user && !IS_LOCAL(user)))
+		return;
+
+	if (!user)
+		user = ServerInstance->FakeClient;
+
+	CommandAddLine::Builder(x, user).Broadcast();
+}
+
+void ModuleSpanningTree::OnDelLine(User* user, XLine* x)
+{
+	if (!x->IsBurstable() || loopCall || (user && !IS_LOCAL(user)))
+		return;
+
+	if (!user)
+		user = ServerInstance->FakeClient;
+
+	CmdBuilder params(user, "DELLINE");
+	params.push(x->type);
+	params.push(x->Displayable());
+	params.Broadcast();
+}
+
+void ModuleSpanningTree::OnUserAway(User* user, const std::optional<AwayState>& prevstate)
+{
+	if (IS_LOCAL(user) && user->IsFullyConnected())
+		CommandAway::Builder(user).Broadcast();
+}
+
+void ModuleSpanningTree::OnUserBack(User* user, const std::optional<AwayState>& prevstate)
+{
+	OnUserAway(user, prevstate);
+}
+
+void ModuleSpanningTree::OnMode(User* source, User* u, Channel* c, const Modes::ChangeList& modes, ModeParser::ModeProcessFlag processflags)
+{
+	if (processflags & ModeParser::MODE_LOCALONLY)
+		return;
+
+	if (u)
+	{
+		if (!u->IsFullyConnected())
+			return;
+
+		CmdBuilder params(source, "MODE");
+		params.push(u->uuid);
+		params.push(ClientProtocol::Messages::Mode::ToModeLetters(modes));
+		params.push_raw(Translate::ModeChangeListToParams(modes.getlist()));
+		params.Broadcast();
+	}
+	else
+	{
+		CmdBuilder params(source, "FMODE");
+		params.push(c->name);
+		params.push_int(c->age);
+		params.push(ClientProtocol::Messages::Mode::ToModeLetters(modes));
+		params.push_raw(Translate::ModeChangeListToParams(modes.getlist()));
+		params.Broadcast();
+	}
+}
+
+void ModuleSpanningTree::OnShutdown(const std::string& reason)
+{
+	const TreeServer::ChildServers& children = Utils->TreeRoot->GetChildren();
+	while (!children.empty())
+		children.front()->SQuit(reason, true);
+}
+
+void ModuleSpanningTree::OnDecodeMetadata(Extensible* target, const std::string& extname, const std::string& extdata)
+{
+	// HACK: this should use automatically synced user metadata.
+	if (target && target->extype == ExtensionType::USER && irc::equals(extname, "uniqueusername"))
+		static_cast<User*>(target)->uniqueusername = (extdata != "0");
+}
+
+Cullable::Result ModuleSpanningTree::Cull()
+{
+	if (Utils)
+		Utils->Cull();
+	return Module::Cull();
+}
+
+ModuleSpanningTree::~ModuleSpanningTree()
+{
+	ServerInstance->PI = &ServerInstance->DefaultProtocolInterface;
+
+	auto* newsrv = new Server(ServerInstance->Config->ServerId, ServerInstance->Config->ServerName, ServerInstance->Config->ServerDesc);
+	SetLocalUsersServer(newsrv);
+
+	delete Utils;
+}
+
+/* It is IMPORTANT that m_spanningtree is the last module in the chain
+ * so that any activity it sees is FINAL, e.g. we arent going to send out
+ * a NICK message before the cloak module has finished putting the +x on the user,
+ * etc etc.
+ * Therefore, we set our priority to PRIORITY_LAST to make sure we end up at the END of
+ * the module call queue.
+ */
+void ModuleSpanningTree::Prioritize()
+{
+	ServerInstance->Modules.SetPriority(this, PRIORITY_LAST);
+	ServerInstance->Modules.SetPriority(this, I_OnPreTopicChange, PRIORITY_FIRST);
+}
+
+MODULE_INIT(ModuleSpanningTree)