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/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2007, 2009 Robin Burchell <robin+git@viroteck.net>
*
* 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"
/** Holds settings and state associated with channel mode +F
*/
class nickfloodsettings
{
public:
unsigned int secs;
unsigned int nicks;
time_t reset;
time_t unlocktime;
unsigned int counter;
nickfloodsettings(unsigned int b, unsigned int c)
: secs(b), nicks(c), unlocktime(0), counter(0)
{
reset = ServerInstance->Time() + secs;
}
void addnick()
{
if (ServerInstance->Time() > reset)
{
counter = 1;
reset = ServerInstance->Time() + secs;
}
else
counter++;
}
bool shouldlock()
{
/* XXX HACK: using counter + 1 here now to allow the counter to only be incremented
* on successful nick changes; this will be checked before the counter is
* incremented.
*/
return ((ServerInstance->Time() <= reset) && (counter == this->nicks));
}
void clear()
{
counter = 0;
}
bool islocked()
{
if (ServerInstance->Time() > unlocktime)
unlocktime = 0;
return (unlocktime != 0);
}
void lock()
{
unlocktime = ServerInstance->Time() + 60;
}
};
/** Handles channel mode +F
*/
class NickFlood : public ModeHandler
{
public:
SimpleExtItem<nickfloodsettings> ext;
NickFlood(Module* Creator) : ModeHandler(Creator, "nickflood", 'F', PARAM_SETONLY, MODETYPE_CHANNEL),
ext("nickflood", Creator) { }
ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string ¶meter, bool adding)
{
if (adding)
{
std::string::size_type colon = parameter.find(':');
if ((colon == std::string::npos) || (parameter.find('-') != std::string::npos))
{
source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
return MODEACTION_DENY;
}
/* Set up the flood parameters for this channel */
unsigned int nnicks = ConvToInt(parameter.substr(0, colon));
unsigned int nsecs = ConvToInt(parameter.substr(colon+1));
if ((nnicks<1) || (nsecs<1))
{
source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
return MODEACTION_DENY;
}
nickfloodsettings* f = ext.get(channel);
if ((f) && (nnicks == f->nicks) && (nsecs == f->secs))
// mode params match
return MODEACTION_DENY;
ext.set(channel, new nickfloodsettings(nsecs, nnicks));
parameter = ConvToStr(nnicks) + ":" + ConvToStr(nsecs);
return MODEACTION_ALLOW;
}
else
{
if (!channel->IsModeSet(this))
return MODEACTION_DENY;
ext.unset(channel);
return MODEACTION_ALLOW;
}
}
};
class ModuleNickFlood : public Module
{
NickFlood nf;
public:
ModuleNickFlood()
: nf(this)
{
}
void init() CXX11_OVERRIDE
{
ServerInstance->Modules->AddService(nf);
ServerInstance->Modules->AddService(nf.ext);
Implementation eventlist[] = { I_OnUserPreNick, I_OnUserPostNick };
ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
}
ModResult OnUserPreNick(User* user, const std::string &newnick) CXX11_OVERRIDE
{
for (UCListIter i = user->chans.begin(); i != user->chans.end(); i++)
{
Channel *channel = *i;
ModResult res;
nickfloodsettings *f = nf.ext.get(channel);
if (f)
{
res = ServerInstance->OnCheckExemption(user,channel,"nickflood");
if (res == MOD_RES_ALLOW)
continue;
if (f->islocked())
{
user->WriteNumeric(447, "%s :%s has been locked for nickchanges for 60 seconds because there have been more than %u nick changes in %u seconds", user->nick.c_str(), channel->name.c_str(), f->nicks, f->secs);
return MOD_RES_DENY;
}
if (f->shouldlock())
{
f->clear();
f->lock();
channel->WriteChannelWithServ((char*)ServerInstance->Config->ServerName.c_str(), "NOTICE %s :No nick changes are allowed for 60 seconds because there have been more than %u nick changes in %u seconds.", channel->name.c_str(), f->nicks, f->secs);
return MOD_RES_DENY;
}
}
}
return MOD_RES_PASSTHRU;
}
/*
* XXX: HACK: We do the increment on the *POST* event here (instead of all together) because we have no way of knowing whether other modules would block a nickchange.
*/
void OnUserPostNick(User* user, const std::string &oldnick) CXX11_OVERRIDE
{
if (isdigit(user->nick[0])) /* allow switches to UID */
return;
for (UCListIter i = user->chans.begin(); i != user->chans.end(); ++i)
{
Channel *channel = *i;
ModResult res;
nickfloodsettings *f = nf.ext.get(channel);
if (f)
{
res = ServerInstance->OnCheckExemption(user,channel,"nickflood");
if (res == MOD_RES_ALLOW)
return;
/* moved this here to avoid incrementing the counter for nick
* changes that are denied for some other reason (bans, +N, etc.)
* per bug #874.
*/
f->addnick();
}
}
}
Version GetVersion() CXX11_OVERRIDE
{
return Version("Channel mode F - nick flood protection", VF_VENDOR);
}
};
MODULE_INIT(ModuleNickFlood)
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