inspircd/src/users.cpp

/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
 *   Copyright (C) 2006-2009 Robin Burchell <robin+git@viroteck.net>
 *   Copyright (C) 2006-2007, 2009 Dennis Friis <peavey@inspircd.org>
 *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
 *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
 *   Copyright (C) 2008 Oliver Lupton <oliverlupton@gmail.com>
 *   Copyright (C) 2003-2008 Craig Edwards <craigedwards@brainbox.cc>
 *
 * 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 "xline.h"

bool User::IsNoticeMaskSet(unsigned char sm)
{
	if (!isalpha(sm))
		return false;
	return (snomasks[sm-65]);
}

bool User::IsModeSet(unsigned char m) const
{
	ModeHandler* mh = ServerInstance->Modes->FindMode(m, MODETYPE_USER);
	return (mh && modes[mh->GetId()]);
}

std::string User::GetModeLetters(bool includeparams) const
{
	std::string ret(1, '+');
	std::string params;

	for (unsigned char i = 'A'; i < 'z'; i++)
	{
		const ModeHandler* const mh = ServerInstance->Modes.FindMode(i, MODETYPE_USER);
		if ((!mh) || (!IsModeSet(mh)))
			continue;

		ret.push_back(mh->GetModeChar());
		if ((includeparams) && (mh->NeedsParam(true)))
		{
			const std::string val = mh->GetUserParameter(this);
			if (!val.empty())
				params.append(1, ' ').append(val);
		}
	}

	ret += params;
	return ret;
}

User::User(const std::string& uid, Server* srv, UserType type)
	: age(ServerInstance->Time())
	, signon(0)
	, uuid(uid)
	, server(srv)
	, registered(REG_NONE)
	, quitting(false)
	, usertype(type)
{
	client_sa.sa.sa_family = AF_UNSPEC;

	ServerInstance->Logs->Log("USERS", LOG_DEBUG, "New UUID for user: %s", uuid.c_str());

	// Do not insert FakeUsers into the uuidlist so FindUUID() won't return them which is the desired behavior
	if (type != USERTYPE_SERVER)
	{
		if (!ServerInstance->Users.uuidlist.insert(std::make_pair(uuid, this)).second)
			throw CoreException("Duplicate UUID in User constructor: " + uuid);
	}
}

LocalUser::LocalUser(int myfd, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* servaddr)
	: User(ServerInstance->UIDGen.GetUID(), ServerInstance->FakeClient->server, USERTYPE_LOCAL)
	, eh(this)
	, bytes_in(0)
	, bytes_out(0)
	, cmds_in(0)
	, cmds_out(0)
	, quitting_sendq(false)
	, lastping(true)
	, exempt(false)
	, nping(0)
	, idle_lastmsg(0)
	, CommandFloodPenalty(0)
	, already_sent(0)
{
	signon = ServerInstance->Time();
	// The user's default nick is their UUID
	nick = uuid;
	ident = "unknown";
	eh.SetFd(myfd);
	memcpy(&client_sa, client, sizeof(irc::sockets::sockaddrs));
	memcpy(&server_sa, servaddr, sizeof(irc::sockets::sockaddrs));
	ChangeRealHost(GetIPString(), true);
}

User::~User()
{
}

const std::string& User::MakeHost()
{
	if (!this->cached_makehost.empty())
		return this->cached_makehost;

	// XXX: Is there really a need to cache this?
	this->cached_makehost = ident + "@" + GetRealHost();
	return this->cached_makehost;
}

const std::string& User::MakeHostIP()
{
	if (!this->cached_hostip.empty())
		return this->cached_hostip;

	// XXX: Is there really a need to cache this?
	this->cached_hostip = ident + "@" + this->GetIPString();
	return this->cached_hostip;
}

const std::string& User::GetFullHost()
{
	if (!this->cached_fullhost.empty())
		return this->cached_fullhost;

	// XXX: Is there really a need to cache this?
	this->cached_fullhost = nick + "!" + ident + "@" + GetDisplayedHost();
	return this->cached_fullhost;
}

const std::string& User::GetFullRealHost()
{
	if (!this->cached_fullrealhost.empty())
		return this->cached_fullrealhost;

	// XXX: Is there really a need to cache this?
	this->cached_fullrealhost = nick + "!" + ident + "@" + GetRealHost();
	return this->cached_fullrealhost;
}

bool User::HasModePermission(const ModeHandler* mh) const
{
	return true;
}

bool LocalUser::HasModePermission(const ModeHandler* mh) const
{
	if (!this->IsOper())
		return false;

	const unsigned char mode = mh->GetModeChar();
	if (mode < 'A' || mode > ('A' + 64)) return false;

	return ((mh->GetModeType() == MODETYPE_USER ? oper->AllowedUserModes : oper->AllowedChanModes))[(mode - 'A')];

}
/*
 * users on remote servers can completely bypass all permissions based checks.
 * This prevents desyncs when one server has different type/class tags to another.
 * That having been said, this does open things up to the possibility of source changes
 * allowing remote kills, etc - but if they have access to the src, they most likely have
 * access to the conf - so it's an end to a means either way.
 */
bool User::HasPermission(const std::string&)
{
	return true;
}

bool LocalUser::HasPermission(const std::string &command)
{
	// are they even an oper at all?
	if (!this->IsOper())
	{
		return false;
	}

	return oper->AllowedOperCommands.Contains(command);
}

bool User::HasPrivPermission(const std::string &privstr, bool noisy)
{
	return true;
}

bool LocalUser::HasPrivPermission(const std::string &privstr, bool noisy)
{
	if (!this->IsOper())
	{
		if (noisy)
			this->WriteNotice("You are not an oper");
		return false;
	}

	if (oper->AllowedPrivs.Contains(privstr))
		return true;

	if (noisy)
		this->WriteNotice("Oper type " + oper->name + " does not have access to priv " + privstr);

	return false;
}

void UserIOHandler::OnDataReady()
{
	if (user->quitting)
		return;

	if (recvq.length() > user->MyClass->GetRecvqMax() && !user->HasPrivPermission("users/flood/increased-buffers"))
	{
		ServerInstance->Users->QuitUser(user, "RecvQ exceeded");
		ServerInstance->SNO->WriteToSnoMask('a', "User %s RecvQ of %lu exceeds connect class maximum of %lu",
			user->nick.c_str(), (unsigned long)recvq.length(), user->MyClass->GetRecvqMax());
		return;
	}

	unsigned long sendqmax = ULONG_MAX;
	if (!user->HasPrivPermission("users/flood/increased-buffers"))
		sendqmax = user->MyClass->GetSendqSoftMax();

	unsigned long penaltymax = ULONG_MAX;
	if (!user->HasPrivPermission("users/flood/no-fakelag"))
		penaltymax = user->MyClass->GetPenaltyThreshold() * 1000;

	// The maximum size of an IRC message minus the terminating CR+LF.
	const size_t maxmessage = ServerInstance->Config->Limits.MaxLine - 2;
	std::string line;
	line.reserve(maxmessage);

	bool eol_found;
	std::string::size_type qpos;

	while (user->CommandFloodPenalty < penaltymax && getSendQSize() < sendqmax)
	{
		qpos = 0;
		eol_found = false;

		const size_t qlen = recvq.length();
		while (qpos < qlen)
		{
			char c = recvq[qpos++];
			switch (c)
			{
				case '\0':
					c = ' ';
					break;
				case '\r':
					continue;
				case '\n':
					eol_found = true;
					break;
			}

			if (eol_found)
				break;

			if (line.length() < maxmessage)
				line.push_back(c);
		}

		// if we return here, we haven't found a newline and make no modifications to recvq
		// so we can wait for more data
		if (!eol_found)
			return;

		// just found a newline. Terminate the string, and pull it out of recvq
		recvq.erase(0, qpos);

		// TODO should this be moved to when it was inserted in recvq?
		ServerInstance->stats.Recv += qpos;
		user->bytes_in += qpos;
		user->cmds_in++;

		ServerInstance->Parser.ProcessBuffer(line, user);
		if (user->quitting)
			return;

		// clear() does not reclaim memory associated with the string, so our .reserve() call is safe
		line.clear();
	}

	if (user->CommandFloodPenalty >= penaltymax && !user->MyClass->fakelag)
		ServerInstance->Users->QuitUser(user, "Excess Flood");
}

void UserIOHandler::AddWriteBuf(const std::string &data)
{
	if (user->quitting_sendq)
		return;
	if (!user->quitting && getSendQSize() + data.length() > user->MyClass->GetSendqHardMax() &&
		!user->HasPrivPermission("users/flood/increased-buffers"))
	{
		user->quitting_sendq = true;
		ServerInstance->GlobalCulls.AddSQItem(user);
		return;
	}

	// We still want to append data to the sendq of a quitting user,
	// e.g. their ERROR message that says 'closing link'

	WriteData(data);
}

void UserIOHandler::OnError(BufferedSocketError)
{
	ServerInstance->Users->QuitUser(user, getError());
}

CullResult User::cull()
{
	if (!quitting)
		ServerInstance->Users->QuitUser(this, "Culled without QuitUser");

	if (client_sa.sa.sa_family != AF_UNSPEC)
		ServerInstance->Users->RemoveCloneCounts(this);

	return Extensible::cull();
}

CullResult LocalUser::cull()
{
	eh.cull();
	return User::cull();
}

CullResult FakeUser::cull()
{
	// Fake users don't quit, they just get culled.
	quitting = true;
	// Fake users are not inserted into UserManager::clientlist or uuidlist, so we don't need to modify those here
	return User::cull();
}

void User::Oper(OperInfo* info)
{
	ModeHandler* opermh = ServerInstance->Modes->FindMode('o', MODETYPE_USER);
	if (this->IsModeSet(opermh))
		this->UnOper();

	this->SetMode(opermh, true);
	this->oper = info;
	this->WriteCommand("MODE", "+o");
	FOREACH_MOD(OnOper, (this, info->name));

	std::string opername;
	if (info->oper_block)
		opername = info->oper_block->getString("name");

	if (IS_LOCAL(this))
	{
		LocalUser* l = IS_LOCAL(this);
		std::string vhost = oper->getConfig("vhost");
		if (!vhost.empty())
			l->ChangeDisplayedHost(vhost);
		std::string opClass = oper->getConfig("class");
		if (!opClass.empty())
			l->SetClass(opClass);
	}

	ServerInstance->SNO->WriteToSnoMask('o',"%s (%s@%s) is now an IRC operator of type %s (using oper '%s')",
		nick.c_str(), ident.c_str(), GetRealHost().c_str(), oper->name.c_str(), opername.c_str());
	this->WriteNumeric(RPL_YOUAREOPER, InspIRCd::Format("You are now %s %s", strchr("aeiouAEIOU", oper->name[0]) ? "an" : "a", oper->name.c_str()));

	ServerInstance->Logs->Log("OPER", LOG_DEFAULT, "%s opered as type: %s", GetFullRealHost().c_str(), oper->name.c_str());
	ServerInstance->Users->all_opers.push_back(this);

	// Expand permissions from config for faster lookup
	if (IS_LOCAL(this))
		oper->init();

	FOREACH_MOD(OnPostOper, (this, oper->name, opername));
}

void OperInfo::init()
{
	AllowedOperCommands.Clear();
	AllowedPrivs.Clear();
	AllowedUserModes.reset();
	AllowedChanModes.reset();
	AllowedUserModes['o' - 'A'] = true; // Call me paranoid if you want.

	for(std::vector<reference<ConfigTag> >::iterator iter = class_blocks.begin(); iter != class_blocks.end(); ++iter)
	{
		ConfigTag* tag = *iter;

		AllowedOperCommands.AddList(tag->getString("commands"));
		AllowedPrivs.AddList(tag->getString("privs"));

		std::string modes = tag->getString("usermodes");
		for (std::string::const_iterator c = modes.begin(); c != modes.end(); ++c)
		{
			if (*c == '*')
			{
				this->AllowedUserModes.set();
			}
			else if (*c >= 'A' && *c <= 'z')
			{
				this->AllowedUserModes[*c - 'A'] = true;
			}
		}

		modes = tag->getString("chanmodes");
		for (std::string::const_iterator c = modes.begin(); c != modes.end(); ++c)
		{
			if (*c == '*')
			{
				this->AllowedChanModes.set();
			}
			else if (*c >= 'A' && *c <= 'z')
			{
				this->AllowedChanModes[*c - 'A'] = true;
			}
		}
	}
}

void User::UnOper()
{
	if (!this->IsOper())
		return;

	/*
	 * unset their oper type (what IS_OPER checks).
	 * note, order is important - this must come before modes as -o attempts
	 * to call UnOper. -- w00t
	 */
	oper = NULL;


	/* Remove all oper only modes from the user when the deoper - Bug #466*/
	Modes::ChangeList changelist;
	const ModeParser::ModeHandlerMap& usermodes = ServerInstance->Modes->GetModes(MODETYPE_USER);
	for (ModeParser::ModeHandlerMap::const_iterator i = usermodes.begin(); i != usermodes.end(); ++i)
	{
		ModeHandler* mh = i->second;
		if (mh->NeedsOper())
			changelist.push_remove(mh);
	}

	ServerInstance->Modes->Process(this, NULL, this, changelist);

	// Remove the user from the oper list
	stdalgo::vector::swaperase(ServerInstance->Users->all_opers, this);

	ModeHandler* opermh = ServerInstance->Modes->FindMode('o', MODETYPE_USER);
	this->SetMode(opermh, false);
	FOREACH_MOD(OnPostDeoper, (this));
}

/*
 * Check class restrictions
 */
void LocalUser::CheckClass(bool clone_count)
{
	ConnectClass* a = this->MyClass;

	if (!a)
	{
		ServerInstance->Users->QuitUser(this, "Access denied by configuration");
		return;
	}
	else if (a->type == CC_DENY)
	{
		ServerInstance->Users->QuitUser(this, a->config->getString("reason", "Unauthorised connection"));
		return;
	}
	else if (clone_count)
	{
		const UserManager::CloneCounts& clonecounts = ServerInstance->Users->GetCloneCounts(this);
		if ((a->GetMaxLocal()) && (clonecounts.local > a->GetMaxLocal()))
		{
			ServerInstance->Users->QuitUser(this, "No more connections allowed from your host via this connect class (local)");
			if (a->maxconnwarn)
				ServerInstance->SNO->WriteToSnoMask('a', "WARNING: maximum LOCAL connections (%ld) exceeded for IP %s", a->GetMaxLocal(), this->GetIPString().c_str());
			return;
		}
		else if ((a->GetMaxGlobal()) && (clonecounts.global > a->GetMaxGlobal()))
		{
			ServerInstance->Users->QuitUser(this, "No more connections allowed from your host via this connect class (global)");
			if (a->maxconnwarn)
				ServerInstance->SNO->WriteToSnoMask('a', "WARNING: maximum GLOBAL connections (%ld) exceeded for IP %s", a->GetMaxGlobal(), this->GetIPString().c_str());
			return;
		}
	}

	this->nping = ServerInstance->Time() + a->GetPingTime();
}

bool LocalUser::CheckLines(bool doZline)
{
	const char* check[] = { "G" , "K", (doZline) ? "Z" : NULL, NULL };

	if (!this->exempt)
	{
		for (int n = 0; check[n]; ++n)
		{
			XLine *r = ServerInstance->XLines->MatchesLine(check[n], this);

			if (r)
			{
				r->Apply(this);
				return true;
			}
		}
	}

	return false;
}

void LocalUser::FullConnect()
{
	ServerInstance->stats.Connects++;
	this->idle_lastmsg = ServerInstance->Time();

	/*
	 * You may be thinking "wtf, we checked this in User::AddClient!" - and yes, we did, BUT.
	 * At the time AddClient is called, we don't have a resolved host, by here we probably do - which
	 * may put the user into a totally seperate class with different restrictions! so we *must* check again.
	 * Don't remove this! -- w00t
	 */
	MyClass = NULL;
	SetClass();
	CheckClass();
	CheckLines();

	if (quitting)
		return;

	this->WriteNumeric(RPL_WELCOME, InspIRCd::Format("Welcome to the %s IRC Network %s", ServerInstance->Config->Network.c_str(), GetFullRealHost().c_str()));
	this->WriteNumeric(RPL_YOURHOSTIS, InspIRCd::Format("Your host is %s, running version %s", ServerInstance->Config->ServerName.c_str(), INSPIRCD_BRANCH));
	this->WriteNumeric(RPL_SERVERCREATED, InspIRCd::TimeString(ServerInstance->startup_time, "This server was created %H:%M:%S %b %d %Y"));

	const TR1NS::array<std::string, 3>& modelist = ServerInstance->Modes->GetModeListFor004Numeric();
	this->WriteNumeric(RPL_SERVERVERSION, ServerInstance->Config->ServerName, INSPIRCD_BRANCH, modelist[0], modelist[1], modelist[2]);

	ServerInstance->ISupport.SendTo(this);

	/* Now registered */
	if (ServerInstance->Users->unregistered_count)
		ServerInstance->Users->unregistered_count--;

	/* Trigger MOTD and LUSERS output, give modules a chance too */
	ModResult MOD_RESULT;
	std::string command("LUSERS");
	std::vector<std::string> parameters;
	FIRST_MOD_RESULT(OnPreCommand, MOD_RESULT, (command, parameters, this, true, command));
	if (!MOD_RESULT)
		ServerInstance->Parser.CallHandler(command, parameters, this);

	MOD_RESULT = MOD_RES_PASSTHRU;
	command = "MOTD";
	FIRST_MOD_RESULT(OnPreCommand, MOD_RESULT, (command, parameters, this, true, command));
	if (!MOD_RESULT)
		ServerInstance->Parser.CallHandler(command, parameters, this);

	if (ServerInstance->Config->RawLog)
		WriteServ("PRIVMSG %s :*** Raw I/O logging is enabled on this server. All messages, passwords, and commands are being recorded.", nick.c_str());

	/*
	 * We don't set REG_ALL until triggering OnUserConnect, so some module events don't spew out stuff
	 * for a user that doesn't exist yet.
	 */
	FOREACH_MOD(OnUserConnect, (this));

	this->registered = REG_ALL;

	FOREACH_MOD(OnPostConnect, (this));

	ServerInstance->SNO->WriteToSnoMask('c',"Client connecting on port %d (class %s): %s (%s) [%s]",
		this->GetServerPort(), this->MyClass->name.c_str(), GetFullRealHost().c_str(), this->GetIPString().c_str(), this->fullname.c_str());
	ServerInstance->Logs->Log("BANCACHE", LOG_DEBUG, "BanCache: Adding NEGATIVE hit for " + this->GetIPString());
	ServerInstance->BanCache.AddHit(this->GetIPString(), "", "");
	// reset the flood penalty (which could have been raised due to things like auto +x)
	CommandFloodPenalty = 0;
}

void User::InvalidateCache()
{
	/* Invalidate cache */
	cachedip.clear();
	cached_fullhost.clear();
	cached_hostip.clear();
	cached_makehost.clear();
	cached_fullrealhost.clear();
}

bool User::ChangeNick(const std::string& newnick, time_t newts)
{
	if (quitting)
	{
		ServerInstance->Logs->Log("USERS", LOG_DEFAULT, "ERROR: Attempted to change nick of a quitting user: " + this->nick);
		return false;
	}

	User* const InUse = ServerInstance->FindNickOnly(newnick);
	if (InUse == this)
	{
		// case change, don't need to check campers
		// and, if it's identical including case, we can leave right now
		// We also don't update the nick TS if it's a case change, either
		if (newnick == nick)
			return true;
	}
	else
	{
		/*
		 * Uh oh.. if the nickname is in use, and it's not in use by the person using it (doh) --
		 * then we have a potential collide. Check whether someone else is camping on the nick
		 * (i.e. connect -> send NICK, don't send USER.) If they are camping, force-change the
		 * camper to their UID, and allow the incoming nick change.
		 *
		 * If the guy using the nick is already using it, tell the incoming nick change to gtfo,
		 * because the nick is already (rightfully) in use. -- w00t
		 */
		if (InUse)
		{
			if (InUse->registered != REG_ALL)
			{
				/* force the camper to their UUID, and ask them to re-send a NICK. */
				LocalUser* const localuser = static_cast<LocalUser*>(InUse);
				localuser->OverruleNick();
			}
			else
			{
				/* No camping, tell the incoming user  to stop trying to change nick ;p */
				this->WriteNumeric(ERR_NICKNAMEINUSE, newnick, "Nickname is already in use.");
				return false;
			}
		}

		age = newts ? newts : ServerInstance->Time();
	}

	if (this->registered == REG_ALL)
		this->WriteCommon("NICK %s", newnick.c_str());
	const std::string oldnick = nick;
	nick = newnick;

	InvalidateCache();
	ServerInstance->Users->clientlist.erase(oldnick);
	ServerInstance->Users->clientlist[newnick] = this;

	if (registered == REG_ALL)
		FOREACH_MOD(OnUserPostNick, (this,oldnick));

	return true;
}

void LocalUser::OverruleNick()
{
	this->WriteFrom(this, "NICK %s", this->uuid.c_str());
	this->WriteNumeric(ERR_NICKNAMEINUSE, this->nick, "Nickname overruled.");

	// Clear the bit before calling ChangeNick() to make it NOT run the OnUserPostNick() hook
	this->registered &= ~REG_NICK;
	this->ChangeNick(this->uuid);
}

int LocalUser::GetServerPort()
{
	return this->server_sa.port();
}

const std::string& User::GetIPString()
{
	if (cachedip.empty())
	{
		cachedip = client_sa.addr();
		/* IP addresses starting with a : on irc are a Bad Thing (tm) */
		if (cachedip[0] == ':')
			cachedip.insert(cachedip.begin(),1,'0');
	}

	return cachedip;
}

const std::string& User::GetHost(bool uncloak) const
{
	return uncloak ? GetRealHost() : GetDisplayedHost();
}

const std::string& User::GetDisplayedHost() const
{
	return displayhost.empty() ? realhost : displayhost;
}

const std::string& User::GetRealHost() const
{
	return realhost;
}

irc::sockets::cidr_mask User::GetCIDRMask()
{
	unsigned char range = 0;
	switch (client_sa.sa.sa_family)
	{
		case AF_INET6:
			range = ServerInstance->Config->c_ipv6_range;
			break;
		case AF_INET:
			range = ServerInstance->Config->c_ipv4_range;
			break;
	}
	return irc::sockets::cidr_mask(client_sa, range);
}

bool User::SetClientIP(const std::string& address, bool recheck_eline)
{
	this->InvalidateCache();
	return irc::sockets::aptosa(address, 0, client_sa);
}

void User::SetClientIP(const irc::sockets::sockaddrs& sa, bool recheck_eline)
{
	this->InvalidateCache();
	memcpy(&client_sa, &sa, sizeof(irc::sockets::sockaddrs));
}

bool LocalUser::SetClientIP(const std::string& address, bool recheck_eline)
{
	irc::sockets::sockaddrs sa;
	if (!irc::sockets::aptosa(address, 0, sa))
		// Invalid
		return false;

	LocalUser::SetClientIP(sa, recheck_eline);
	return true;
}

void LocalUser::SetClientIP(const irc::sockets::sockaddrs& sa, bool recheck_eline)
{
	if (sa != client_sa)
	{
		User::SetClientIP(sa);
		if (recheck_eline)
			this->exempt = (ServerInstance->XLines->MatchesLine("E", this) != NULL);

		FOREACH_MOD(OnSetUserIP, (this));
	}
}

static std::string wide_newline("\r\n");

void User::Write(const std::string& text)
{
}

void User::Write(const char *text, ...)
{
}

void LocalUser::Write(const std::string& text)
{
	if (!SocketEngine::BoundsCheckFd(&eh))
		return;

	// The maximum size of an IRC message minus the terminating CR+LF.
	const size_t maxmessage = ServerInstance->Config->Limits.MaxLine - 2;
	if (text.length() > maxmessage)
	{
		// This should happen rarely or never. Crop the string at MaxLine and try again.
		std::string try_again(text, 0, maxmessage);
		Write(try_again);
		return;
	}

	ServerInstance->Logs->Log("USEROUTPUT", LOG_RAWIO, "C[%s] O %s", uuid.c_str(), text.c_str());

	eh.AddWriteBuf(text);
	eh.AddWriteBuf(wide_newline);

	const size_t bytessent = text.length() + 2;
	ServerInstance->stats.Sent += bytessent;
	this->bytes_out += bytessent;
	this->cmds_out++;
}

/** Write()
 */
void LocalUser::Write(const char *text, ...)
{
	std::string textbuffer;
	VAFORMAT(textbuffer, text, text);
	this->Write(textbuffer);
}

void User::WriteServ(const std::string& text)
{
	this->Write(":%s %s",ServerInstance->Config->ServerName.c_str(),text.c_str());
}

/** WriteServ()
 *  Same as Write(), except `text' is prefixed with `:server.name '.
 */
void User::WriteServ(const char* text, ...)
{
	std::string textbuffer;
	VAFORMAT(textbuffer, text, text);
	this->WriteServ(textbuffer);
}

void User::WriteCommand(const char* command, const std::string& text)
{
	this->WriteServ(command + (this->registered & REG_NICK ? " " + this->nick : " *") + " " + text);
}

namespace
{
	std::string BuildNumeric(const std::string& source, User* targetuser, unsigned int num, const std::vector<std::string>& params)
	{
		const char* const target = (targetuser->registered & REG_NICK ? targetuser->nick.c_str() : "*");
		std::string raw = InspIRCd::Format(":%s %03u %s", source.c_str(), num, target);
		if (!params.empty())
		{
			for (std::vector<std::string>::const_iterator i = params.begin(); i != params.end()-1; ++i)
				raw.append(1, ' ').append(*i);
			raw.append(" :").append(params.back());
		}
		return raw;
	}
}

void User::WriteNumeric(const Numeric::Numeric& numeric)
{
	ModResult MOD_RESULT;

	FIRST_MOD_RESULT(OnNumeric, MOD_RESULT, (this, numeric));

	if (MOD_RESULT == MOD_RES_DENY)
		return;

	const std::string& servername = (numeric.GetServer() ? numeric.GetServer()->GetName() : ServerInstance->Config->ServerName);
	this->Write(BuildNumeric(servername, this, numeric.GetNumeric(), numeric.GetParams()));
}

void User::WriteFrom(User *user, const std::string &text)
{
	const std::string message = ":" + user->GetFullHost() + " " + text;
	this->Write(message);
}


/* write text from an originating user to originating user */

void User::WriteFrom(User *user, const char* text, ...)
{
	std::string textbuffer;
	VAFORMAT(textbuffer, text, text);
	this->WriteFrom(user, textbuffer);
}

void User::WriteRemoteNotice(const std::string& text)
{
	ServerInstance->PI->SendUserNotice(this, text);
}

void LocalUser::WriteRemoteNotice(const std::string& text)
{
	WriteNotice(text);
}

namespace
{
	class WriteCommonRawHandler : public User::ForEachNeighborHandler
	{
		const std::string& msg;

		void Execute(LocalUser* user) CXX11_OVERRIDE
		{
			user->Write(msg);
		}

	 public:
		WriteCommonRawHandler(const std::string& message)
			: msg(message)
		{
		}
	};
}

void User::WriteCommon(const char* text, ...)
{
	std::string textbuffer;
	VAFORMAT(textbuffer, text, text);
	textbuffer = ":" + this->GetFullHost() + " " + textbuffer;
	this->WriteCommonRaw(textbuffer, true);
}

void User::WriteCommonRaw(const std::string &line, bool include_self)
{
	WriteCommonRawHandler handler(line);
	ForEachNeighbor(handler, include_self);
}

void User::ForEachNeighbor(ForEachNeighborHandler& handler, bool include_self)
{
	// The basic logic for visiting the neighbors of a user is to iterate the channel list of the user
	// and visit all users on those channels. Because two users may share more than one common channel,
	// we must skip users that we have already visited.
	// To do this, we make use of a global counter and an integral 'already_sent' field in LocalUser.
	// The global counter is incremented every time we do something for each neighbor of a user. Then,
	// before visiting a member we examine user->already_sent. If it's equal to the current counter, we
	// skip the member. Otherwise, we set it to the current counter and visit the member.

	// Ask modules to build a list of exceptions.
	// Mods may also exclude entire channels by erasing them from include_chans.
	IncludeChanList include_chans(chans.begin(), chans.end());
	std::map<User*, bool> exceptions;
	exceptions[this] = include_self;
	FOREACH_MOD(OnBuildNeighborList, (this, include_chans, exceptions));

	// Get next id, guaranteed to differ from the already_sent field of all users
	const already_sent_t newid = ServerInstance->Users.NextAlreadySentId();

	// Handle exceptions first
	for (std::map<User*, bool>::const_iterator i = exceptions.begin(); i != exceptions.end(); ++i)
	{
		LocalUser* curr = IS_LOCAL(i->first);
		if (curr)
		{
			// Mark as visited to ensure we won't visit again if there is a common channel
			curr->already_sent = newid;
			// Always treat quitting users as excluded
			if ((i->second) && (!curr->quitting))
				handler.Execute(curr);
		}
	}

	// Now consider the real neighbors
	for (IncludeChanList::const_iterator i = include_chans.begin(); i != include_chans.end(); ++i)
	{
		Channel* chan = (*i)->chan;
		const Channel::MemberMap& userlist = chan->GetUsers();
		for (Channel::MemberMap::const_iterator j = userlist.begin(); j != userlist.end(); ++j)
		{
			LocalUser* curr = IS_LOCAL(j->first);
			// User not yet visited?
			if ((curr) && (curr->already_sent != newid))
			{
				// Mark as visited and execute function
				curr->already_sent = newid;
				handler.Execute(curr);
			}
		}
	}
}

void User::WriteRemoteNumeric(const Numeric::Numeric& numeric)
{
	WriteNumeric(numeric);
}

/* return 0 or 1 depending if users u and u2 share one or more common channels
 * (used by QUIT, NICK etc which arent channel specific notices)
 *
 * The old algorithm in 1.0 for this was relatively inefficient, iterating over
 * the first users channels then the second users channels within the outer loop,
 * therefore it was a maximum of x*y iterations (upon returning 0 and checking
 * all possible iterations). However this new function instead checks against the
 * channel's userlist in the inner loop which is a std::map<User*,User*>
 * and saves us time as we already know what pointer value we are after.
 * Don't quote me on the maths as i am not a mathematician or computer scientist,
 * but i believe this algorithm is now x+(log y) maximum iterations instead.
 */
bool User::SharesChannelWith(User *other)
{
	/* Outer loop */
	for (User::ChanList::iterator i = this->chans.begin(); i != this->chans.end(); ++i)
	{
		/* Eliminate the inner loop (which used to be ~equal in size to the outer loop)
		 * by replacing it with a map::find which *should* be more efficient
		 */
		if ((*i)->chan->HasUser(other))
			return true;
	}
	return false;
}

bool User::ChangeName(const std::string& gecos)
{
	if (!this->fullname.compare(gecos))
		return true;

	if (IS_LOCAL(this))
	{
		ModResult MOD_RESULT;
		FIRST_MOD_RESULT(OnChangeLocalUserGECOS, MOD_RESULT, (IS_LOCAL(this),gecos));
		if (MOD_RESULT == MOD_RES_DENY)
			return false;
		FOREACH_MOD(OnChangeName, (this,gecos));
	}
	this->fullname.assign(gecos, 0, ServerInstance->Config->Limits.MaxGecos);

	return true;
}

bool User::ChangeDisplayedHost(const std::string& shost)
{
	if (GetDisplayedHost() == shost)
		return true;

	if (IS_LOCAL(this))
	{
		ModResult MOD_RESULT;
		FIRST_MOD_RESULT(OnChangeLocalUserHost, MOD_RESULT, (IS_LOCAL(this),shost));
		if (MOD_RESULT == MOD_RES_DENY)
			return false;
	}

	FOREACH_MOD(OnChangeHost, (this,shost));

	if (realhost == shost)
		this->displayhost.clear();
	else
		this->displayhost.assign(shost, 0, ServerInstance->Config->Limits.MaxHost);

	this->InvalidateCache();

	if (IS_LOCAL(this))
		this->WriteNumeric(RPL_YOURDISPLAYEDHOST, this->GetDisplayedHost(), "is now your displayed host");

	return true;
}

void User::ChangeRealHost(const std::string& host, bool resetdisplay)
{
	// If the real host is the new host and we are not resetting the
	// display host then we have nothing to do.
	const bool changehost = (realhost != host);
	if (!changehost && !resetdisplay)
		return;
	
	// If the displayhost is not set and we are not resetting it then
	// we need to copy it to the displayhost field.
	if (displayhost.empty() && !resetdisplay)
		displayhost = realhost;

	// If the displayhost is the new host or we are resetting it then
	// we clear its contents to save memory.
	else if (displayhost == host || resetdisplay)
		displayhost.clear();

	// If we are just resetting the display host then we don't need to
	// do anything else.
	if (!changehost)
		return;

	realhost = host;
	this->InvalidateCache();
}

bool User::ChangeIdent(const std::string& newident)
{
	if (this->ident == newident)
		return true;

	FOREACH_MOD(OnChangeIdent, (this,newident));

	this->ident.assign(newident, 0, ServerInstance->Config->Limits.IdentMax);
	this->InvalidateCache();

	return true;
}

/*
 * Sets a user's connection class.
 * If the class name is provided, it will be used. Otherwise, the class will be guessed using host/ip/ident/etc.
 * NOTE: If the <ALLOW> or <DENY> tag specifies an ip, and this user resolves,
 * then their ip will be taken as 'priority' anyway, so for example,
 * <connect allow="127.0.0.1"> will match joe!bloggs@localhost
 */
void LocalUser::SetClass(const std::string &explicit_name)
{
	ConnectClass *found = NULL;

	ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "Setting connect class for UID %s", this->uuid.c_str());

	if (!explicit_name.empty())
	{
		for (ServerConfig::ClassVector::const_iterator i = ServerInstance->Config->Classes.begin(); i != ServerInstance->Config->Classes.end(); ++i)
		{
			ConnectClass* c = *i;

			if (explicit_name == c->name)
			{
				ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "Explicitly set to %s", explicit_name.c_str());
				found = c;
			}
		}
	}
	else
	{
		for (ServerConfig::ClassVector::const_iterator i = ServerInstance->Config->Classes.begin(); i != ServerInstance->Config->Classes.end(); ++i)
		{
			ConnectClass* c = *i;
			ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "Checking %s", c->GetName().c_str());

			ModResult MOD_RESULT;
			FIRST_MOD_RESULT(OnSetConnectClass, MOD_RESULT, (this,c));
			if (MOD_RESULT == MOD_RES_DENY)
				continue;
			if (MOD_RESULT == MOD_RES_ALLOW)
			{
				ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "Class forced by module to %s", c->GetName().c_str());
				found = c;
				break;
			}

			if (c->type == CC_NAMED)
				continue;

			bool regdone = (registered != REG_NONE);
			if (c->config->getBool("registered", regdone) != regdone)
				continue;

			/* check if host matches.. */
			if (!InspIRCd::MatchCIDR(this->GetIPString(), c->GetHost(), NULL) &&
			    !InspIRCd::MatchCIDR(this->GetRealHost(), c->GetHost(), NULL))
			{
				ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "No host match (for %s)", c->GetHost().c_str());
				continue;
			}

			/*
			 * deny change if change will take class over the limit check it HERE, not after we found a matching class,
			 * because we should attempt to find another class if this one doesn't match us. -- w00t
			 */
			if (c->limit && (c->GetReferenceCount() >= c->limit))
			{
				ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "OOPS: Connect class limit (%lu) hit, denying", c->limit);
				continue;
			}

			/* if it requires a port ... */
			if (!c->ports.empty())
			{
				/* and our port doesn't match, fail. */
				if (!c->ports.count(this->GetServerPort()))
				{
					ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "Requires a different port, skipping");
					continue;
				}
			}

			if (regdone && !c->config->getString("password").empty())
			{
				if (!ServerInstance->PassCompare(this, c->config->getString("password"), password, c->config->getString("hash")))
				{
					ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "Bad password, skipping");
					continue;
				}
			}

			/* we stop at the first class that meets ALL critera. */
			found = c;
			break;
		}
	}

	/*
	 * Okay, assuming we found a class that matches.. switch us into that class, keeping refcounts up to date.
	 */
	if (found)
	{
		MyClass = found;
	}
}

void User::PurgeEmptyChannels()
{
	// firstly decrement the count on each channel
	for (User::ChanList::iterator i = this->chans.begin(); i != this->chans.end(); )
	{
		Channel* c = (*i)->chan;
		++i;
		c->DelUser(this);
	}

	this->UnOper();
}

const std::string& FakeUser::GetFullHost()
{
	if (!ServerInstance->Config->HideServer.empty())
		return ServerInstance->Config->HideServer;
	return server->GetName();
}

const std::string& FakeUser::GetFullRealHost()
{
	if (!ServerInstance->Config->HideServer.empty())
		return ServerInstance->Config->HideServer;
	return server->GetName();
}

ConnectClass::ConnectClass(ConfigTag* tag, char t, const std::string& mask)
	: config(tag), type(t), fakelag(true), name("unnamed"), registration_timeout(0), host(mask),
	pingtime(0), softsendqmax(0), hardsendqmax(0), recvqmax(0),
	penaltythreshold(0), commandrate(0), maxlocal(0), maxglobal(0), maxconnwarn(true), maxchans(ServerInstance->Config->MaxChans),
	limit(0), resolvehostnames(true)
{
}

ConnectClass::ConnectClass(ConfigTag* tag, char t, const std::string& mask, const ConnectClass& parent)
{
	Update(&parent);
	name = "unnamed";
	type = t;
	host = mask;

	// Connect classes can inherit from each other but this is problematic for modules which can't use
	// ConnectClass::Update so we build a hybrid tag containing all of the values set on this class as
	// well as the parent class.
	ConfigItems* items = NULL;
	config = ConfigTag::create(tag->tag, tag->src_name, tag->src_line, items);

	const ConfigItems& parentkeys = parent.config->getItems();
	for (ConfigItems::const_iterator piter = parentkeys.begin(); piter != parentkeys.end(); ++piter)
	{
		// The class name and parent name are not inherited
		if (piter->first == "name" || piter->first == "parent")
			continue;

		// Store the item in the config tag. If this item also
		// exists in the child it will be overwritten.
		(*items)[piter->first] = piter->second;
	}

	const ConfigItems& childkeys = tag->getItems();
	for (ConfigItems::const_iterator citer = childkeys.begin(); citer != childkeys.end(); ++citer)
	{
		// This will overwrite the parent value if present.
		(*items)[citer->first] = citer->second;
	}
}

void ConnectClass::Update(const ConnectClass* src)
{
	config = src->config;
	type = src->type;
	fakelag = src->fakelag;
	name = src->name;
	registration_timeout = src->registration_timeout;
	host = src->host;
	pingtime = src->pingtime;
	softsendqmax = src->softsendqmax;
	hardsendqmax = src->hardsendqmax;
	recvqmax = src->recvqmax;
	penaltythreshold = src->penaltythreshold;
	commandrate = src->commandrate;
	maxlocal = src->maxlocal;
	maxglobal = src->maxglobal;
	maxconnwarn = src->maxconnwarn;
	maxchans = src->maxchans;
	limit = src->limit;
	resolvehostnames = src->resolvehostnames;
	ports = src->ports;
}