1 files changed, 403 insertions, 0 deletions
diff --git a/src/modules/m_repeat.cpp b/src/modules/m_repeat.cpp
new file mode 100644
index 000000000..b992fe0f4
--- /dev/null
+++ b/src/modules/m_repeat.cpp
@@ -0,0 +1,403 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2013 Daniel Vassdal <shutter@canternet.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"
+
+class ChannelSettings
+{
+ public:
+ 	enum RepeatAction
+	{
+		ACT_KICK,
+		ACT_BLOCK,
+		ACT_BAN
+	};
+
+	RepeatAction Action;
+	unsigned int Backlog;
+	unsigned int Lines;
+	unsigned int Diff;
+	unsigned int Seconds;
+
+	void serialize(std::string& out) const
+	{
+		if (Action == ACT_BAN)
+			out.push_back('*');
+		else if (Action == ACT_BLOCK)
+			out.push_back('~');
+
+		out.append(ConvToStr(Lines)).push_back(':');
+		out.append(ConvToStr(Seconds));
+		if (Diff)
+		{
+			out.push_back(':');
+			out.append(ConvToStr(Diff));
+			if (Backlog)
+			{
+				out.push_back(':');
+				out.append(ConvToStr(Backlog));
+			}
+		}
+	}
+};
+
+class RepeatMode : public ParamMode<RepeatMode, SimpleExtItem<ChannelSettings> >
+{
+ private:
+	struct RepeatItem
+	{
+		time_t ts;
+		std::string line;
+		RepeatItem(time_t TS, const std::string& Line) : ts(TS), line(Line) { }
+	};
+
+	typedef std::deque<RepeatItem> RepeatItemList;
+
+	struct MemberInfo
+	{
+		RepeatItemList ItemList;
+		unsigned int Counter;
+		MemberInfo() : Counter(0) {}
+	};
+
+	struct ModuleSettings
+	{
+		unsigned int MaxLines;
+		unsigned int MaxSecs;
+		unsigned int MaxBacklog;
+		unsigned int MaxDiff;
+		unsigned int MaxMessageSize;
+		ModuleSettings() : MaxLines(0), MaxSecs(0), MaxBacklog(0), MaxDiff() { }
+	};
+
+	std::vector<unsigned int> mx[2];
+	ModuleSettings ms;
+
+	bool CompareLines(const std::string& message, const std::string& historyline, unsigned int trigger)
+	{
+		if (message == historyline)
+			return true;
+		else if (trigger)
+			return (Levenshtein(message, historyline) <= trigger);
+
+		return false;
+	}
+
+	unsigned int Levenshtein(const std::string& s1, const std::string& s2)
+	{
+		unsigned int l1 = s1.size();
+		unsigned int l2 = s2.size();
+
+		for (unsigned int i = 0; i < l2; i++)
+			mx[0][i] = i;
+		for (unsigned int i = 0; i < l1; i++)
+		{
+			mx[1][0] = i + 1;
+			for (unsigned int j = 0; j < l2; j++)
+	            mx[1][j + 1] = std::min(std::min(mx[1][j] + 1, mx[0][j + 1] + 1), mx[0][j] + ((s1[i] == s2[j]) ? 0 : 1));
+
+			mx[0].swap(mx[1]);
+		}
+		return mx[0][l2];
+	}
+
+ public:
+	SimpleExtItem<MemberInfo> MemberInfoExt;
+
+	RepeatMode(Module* Creator)
+		: ParamMode<RepeatMode, SimpleExtItem<ChannelSettings> >(Creator, "repeat", 'E')
+		, MemberInfoExt("repeat_memb", Creator)
+	{
+	}
+
+	void OnUnset(User* source, Channel* chan)
+	{
+		// Unset the per-membership extension when the mode is removed
+		const Channel::MemberMap& users = chan->GetUsers();
+		for (Channel::MemberMap::const_iterator i = users.begin(); i != users.end(); ++i)
+			MemberInfoExt.unset(i->second);
+	}
+
+	ModeAction OnSet(User* source, Channel* channel, std::string& parameter)
+	{
+		ChannelSettings settings;
+		if (!ParseSettings(source, parameter, settings))
+		{
+			source->WriteNotice("*** Invalid syntax. Syntax is {[~*]}[lines]:[time]{:[difference]}{:[backlog]}");
+			return MODEACTION_DENY;
+		}
+
+		if ((settings.Backlog > 0) && (settings.Lines > settings.Backlog))
+		{
+			source->WriteNotice("*** You can't set needed lines higher than backlog");
+			return MODEACTION_DENY;
+		}
+
+		LocalUser* localsource = IS_LOCAL(source);
+		if ((localsource) && (!ValidateSettings(localsource, settings)))
+			return MODEACTION_DENY;
+
+		ext.set(channel, settings);
+
+		return MODEACTION_ALLOW;
+	}
+
+	bool MatchLine(Membership* memb, ChannelSettings* rs, std::string message)
+	{
+		// If the message is larger than whatever size it's set to,
+		// let's pretend it isn't. If the first 512 (def. setting) match, it's probably spam.
+		if (message.size() > ms.MaxMessageSize)
+			message.erase(ms.MaxMessageSize);
+
+		MemberInfo* rp = MemberInfoExt.get(memb);
+		if (!rp)
+		{
+			rp = new MemberInfo;
+			MemberInfoExt.set(memb, rp);
+		}
+
+		unsigned int matches = 0;
+		if (!rs->Backlog)
+			matches = rp->Counter;
+
+		RepeatItemList& items = rp->ItemList;
+		const unsigned int trigger = (message.size() * rs->Diff / 100);
+		const time_t now = ServerInstance->Time();
+
+		std::transform(message.begin(), message.end(), message.begin(), ::tolower);
+
+		for (std::deque<RepeatItem>::iterator it = items.begin(); it != items.end(); ++it)
+		{
+			if (it->ts < now)
+			{
+				items.erase(it, items.end());
+				matches = 0;
+				break;
+			}
+
+			if (CompareLines(message, it->line, trigger))
+			{
+				if (++matches >= rs->Lines)
+				{
+					if (rs->Action != ChannelSettings::ACT_BLOCK)
+						rp->Counter = 0;
+					return true;
+				}
+			}
+			else if ((ms.MaxBacklog == 0) || (rs->Backlog == 0))
+			{
+				matches = 0;
+				items.clear();
+				break;
+			}
+		}
+
+		unsigned int max_items = (rs->Backlog ? rs->Backlog : 1);
+		if (items.size() >= max_items)
+			items.pop_back();
+
+		items.push_front(RepeatItem(now + rs->Seconds, message));
+		rp->Counter = matches;
+		return false;
+	}
+
+	void Resize(size_t size)
+	{
+		size_t newsize = size+1;
+		if (newsize <= mx[0].size())
+			return;
+		ms.MaxMessageSize = size;
+		mx[0].resize(newsize);
+		mx[1].resize(newsize);
+	}
+
+	void ReadConfig()
+	{
+		ConfigTag* conf = ServerInstance->Config->ConfValue("repeat");
+		ms.MaxLines = conf->getInt("maxlines", 20);
+		ms.MaxBacklog = conf->getInt("maxbacklog", 20);
+		ms.MaxSecs = conf->getInt("maxsecs", 0);
+
+		ms.MaxDiff = conf->getInt("maxdistance", 50);
+		if (ms.MaxDiff > 100)
+			ms.MaxDiff = 100;
+
+		unsigned int newsize = conf->getInt("size", 512);
+		if (newsize > ServerInstance->Config->Limits.MaxLine)
+			newsize = ServerInstance->Config->Limits.MaxLine;
+		Resize(newsize);
+	}
+
+	std::string GetModuleSettings() const
+	{
+		return ConvToStr(ms.MaxLines) + ":" + ConvToStr(ms.MaxSecs) + ":" + ConvToStr(ms.MaxDiff) + ":" + ConvToStr(ms.MaxBacklog);
+	}
+
+	void SerializeParam(Channel* chan, const ChannelSettings* chset, std::string& out)
+	{
+		chset->serialize(out);
+	}
+
+ private:
+	bool ParseSettings(User* source, std::string& parameter, ChannelSettings& settings)
+	{
+		irc::sepstream stream(parameter, ':');
+		std::string	item;
+		if (!stream.GetToken(item))
+			// Required parameter missing
+			return false;
+
+		if ((item[0] == '*') || (item[0] == '~'))
+		{
+			settings.Action = ((item[0] == '*') ? ChannelSettings::ACT_BAN : ChannelSettings::ACT_BLOCK);
+			item.erase(item.begin());
+		}
+		else
+			settings.Action = ChannelSettings::ACT_KICK;
+
+		if ((settings.Lines = ConvToInt(item)) == 0)
+			return false;
+
+		if ((!stream.GetToken(item)) || ((settings.Seconds = InspIRCd::Duration(item)) == 0))
+			// Required parameter missing
+			return false;
+
+		// The diff and backlog parameters are optional
+		settings.Diff = settings.Backlog = 0;
+		if (stream.GetToken(item))
+		{
+			// There is a diff parameter, see if it's valid (> 0)
+			if ((settings.Diff = ConvToInt(item)) == 0)
+				return false;
+
+			if (stream.GetToken(item))
+			{
+				// There is a backlog parameter, see if it's valid
+				if ((settings.Backlog = ConvToInt(item)) == 0)
+					return false;
+
+				// If there are still tokens, then it's invalid because we allow only 4
+				if (stream.GetToken(item))
+					return false;
+			}
+		}
+
+		return true;
+	}
+
+	bool ValidateSettings(LocalUser* source, const ChannelSettings& settings)
+	{
+		if (settings.Backlog && !ms.MaxBacklog)
+		{
+			source->WriteNotice("*** The server administrator has disabled backlog matching");
+			return false;
+		}
+
+		if (settings.Diff)
+		{
+			if (settings.Diff > ms.MaxDiff)
+			{
+				if (ms.MaxDiff == 0)
+					source->WriteNotice("*** The server administrator has disabled matching on edit distance");
+				else
+					source->WriteNotice("*** The distance you specified is too great. Maximum allowed is " + ConvToStr(ms.MaxDiff));
+				return false;
+			}
+
+			if (ms.MaxLines && settings.Lines > ms.MaxLines)
+			{
+				source->WriteNotice("*** The line number you specified is too great. Maximum allowed is " + ConvToStr(ms.MaxLines));
+				return false;
+			}
+
+			if (ms.MaxSecs && settings.Seconds > ms.MaxSecs)
+			{
+				source->WriteNotice("*** The seconds you specified is too great. Maximum allowed is " + ConvToStr(ms.MaxSecs));
+				return false;
+			}
+		}
+
+		return true;
+	}
+};
+
+class RepeatModule : public Module
+{
+	RepeatMode rm;
+
+ public:
+	RepeatModule() : rm(this) {}
+
+	void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
+	{
+		rm.ReadConfig();
+	}
+
+	ModResult OnUserPreMessage(User* user, void* dest, int target_type, std::string& text, char status, CUList& exempt_list, MessageType msgtype) CXX11_OVERRIDE
+	{
+		if (target_type != TYPE_CHANNEL || !IS_LOCAL(user))
+			return MOD_RES_PASSTHRU;
+
+		Channel* chan = reinterpret_cast<Channel*>(dest);
+		ChannelSettings* settings = rm.ext.get(chan);
+		if (!settings)
+			return MOD_RES_PASSTHRU;
+
+		Membership* memb = chan->GetUser(user);
+		if (!memb)
+			return MOD_RES_PASSTHRU;
+
+		if (ServerInstance->OnCheckExemption(user, chan, "repeat") == MOD_RES_ALLOW)
+			return MOD_RES_PASSTHRU;
+
+		if (rm.MatchLine(memb, settings, text))
+		{
+			if (settings->Action == ChannelSettings::ACT_BLOCK)
+			{
+				user->WriteNotice("*** This line is too similiar to one of your last lines.");
+				return MOD_RES_DENY;
+			}
+
+			if (settings->Action == ChannelSettings::ACT_BAN)
+			{
+				std::vector<std::string> parameters;
+				parameters.push_back(memb->chan->name);
+				parameters.push_back("+b");
+				parameters.push_back("*!*@" + user->dhost);
+				ServerInstance->Modes->Process(parameters, ServerInstance->FakeClient);
+			}
+
+			memb->chan->KickUser(ServerInstance->FakeClient, user, "Repeat flood");
+			return MOD_RES_DENY;
+		}
+		return MOD_RES_PASSTHRU;
+	}
+
+	void Prioritize() CXX11_OVERRIDE
+	{
+		ServerInstance->Modules->SetPriority(this, I_OnUserPreMessage, PRIORITY_LAST);
+	}
+
+	Version GetVersion() CXX11_OVERRIDE
+	{
+		return Version("Provides the +E channel mode - for blocking of similiar messages", VF_COMMON|VF_VENDOR, rm.GetModuleSettings());
+	}
+};
+
+MODULE_INIT(RepeatModule)