Add ERR_INVALIDMODEPARAM for responding to invalid mode params.

Currently on invalid modes we do a combination of different things:

1. Send a custom mode-specific numeric (which often collides with
   other modes).

2. Send a server notice.

3. Do absolutely nothing.

This new numeric is a generic way of handling invalid parameters
when setting a mode that avoids all of the mistakes of the previous
behaviour.

12 files changed, 98 insertions, 48 deletions

diff --git a/include/numeric.h b/include/numeric.h
index 8ea2447bf..85f2f13f0 100644
--- a/include/numeric.h
+++ b/include/numeric.h
@@ -85,30 +85,3 @@ class Numeric::Numeric
 	 */
 	std::vector<std::string>& GetParams() { return params; }
 };
-
-namespace Numerics
-{
-	/** Builder for the ERR_NOSUCHNICK numeric. */
-	class NoSuchNick : public Numeric::Numeric
-	{
-	 public:
-		NoSuchNick(const std::string& nick)
-			: Numeric(ERR_NOSUCHNICK)
-		{
-			push(nick);
-			push("No such nick");
-		}
-	};
-
-	/** Builder for the ERR_NOSUCHCHANNEL numeric. */
-	class NoSuchChannel : public Numeric::Numeric
-	{
-	 public:
-		NoSuchChannel(const std::string& chan)
-			: Numeric(ERR_NOSUCHCHANNEL)
-		{
-			push(chan);
-			push("No such channel");
-		}
-	};
-}
diff --git a/include/numericbuilder.h b/include/numericbuilder.h
index 17aa9e0c8..0d55093ca 100644
--- a/include/numericbuilder.h
+++ b/include/numericbuilder.h
@@ -196,3 +196,57 @@ class Numeric::ParamBuilder : public GenericParamBuilder<NumStaticParams, SendEm
 	{
 	}
 };
+
+namespace Numerics
+{
+	class InvalidModeParameter;
+	class NoSuchChannel;
+	class NoSuchNick;
+}
+
+/* Builder for the ERR_INVALIDMODEPARAM numeric. */
+class Numerics::InvalidModeParameter : public Numeric::Numeric
+{
+ public:
+	InvalidModeParameter(Channel* chan, ModeHandler* mode, const std::string& parameter, const std::string& message = "")
+		: Numeric(ERR_INVALIDMODEPARAM)
+	{
+		push(chan->name);
+		push(mode->GetModeChar());
+		push(parameter);
+		push(message.empty() ? InspIRCd::Format("Invalid %s mode parameter", mode->name.c_str()) : message);
+	}
+
+	InvalidModeParameter(User* user, ModeHandler* mode, const std::string& parameter, const std::string& message = "")
+		: Numeric(ERR_INVALIDMODEPARAM)
+	{
+		push(user->registered & REG_NICK ? user->nick : "*");
+		push(mode->GetModeChar());
+		push(parameter);
+		push(message.empty() ? InspIRCd::Format("Invalid %s mode parameter", mode->name.c_str()) : message);
+	}
+};
+
+/** Builder for the ERR_NOSUCHCHANNEL numeric. */
+class Numerics::NoSuchChannel : public Numeric::Numeric
+{
+ public:
+	NoSuchChannel(const std::string& chan)
+		: Numeric(ERR_NOSUCHCHANNEL)
+	{
+		push(chan);
+		push("No such channel");
+	}
+};
+
+/** Builder for the ERR_NOSUCHNICK numeric. */
+class Numerics::NoSuchNick : public Numeric::Numeric
+{
+ public:
+	NoSuchNick(const std::string& nick)
+		: Numeric(ERR_NOSUCHNICK)
+	{
+		push(nick);
+		push("No such nick");
+	}
+};
diff --git a/include/numerics.h b/include/numerics.h
index 57ecee4df..740ee1797 100644
--- a/include/numerics.h
+++ b/include/numerics.h
@@ -184,6 +184,7 @@ enum
 	ERR_CANTSENDTOUSER              = 531, // ???
 
 	RPL_SYNTAX                      = 650, // insp-specific
+	ERR_INVALIDMODEPARAM            = 696, // insp-specific
 
 	ERR_CHANOPEN                    = 713,
 	ERR_KNOCKONCHAN                 = 714,
diff --git a/src/mode.cpp b/src/mode.cpp
index c07c342a3..9d17f5be8 100644
--- a/src/mode.cpp
+++ b/src/mode.cpp
@@ -89,6 +89,11 @@ void ModeHandler::DisplayEmptyList(User*, Channel*)
 
 void ModeHandler::OnParameterMissing(User* user, User* dest, Channel* channel)
 {
+	const std::string message = InspIRCd::Format("You must specify a parameter for the %s mode", name.c_str());
+	if (channel)
+		user->WriteNumeric(Numerics::InvalidModeParameter(channel, this, "*", message));
+	else
+		user->WriteNumeric(Numerics::InvalidModeParameter(dest, this, "*", message));
 }
 
 bool ModeHandler::ResolveModeConflict(std::string& theirs, const std::string& ours, Channel*)
diff --git a/src/modules/m_chanfilter.cpp b/src/modules/m_chanfilter.cpp
index e7dc6372b..d201f5418 100644
--- a/src/modules/m_chanfilter.cpp
+++ b/src/modules/m_chanfilter.cpp
@@ -37,7 +37,7 @@ class ChanFilter : public ListModeBase
 	bool ValidateParam(User* user, Channel* chan, std::string& word) CXX11_OVERRIDE	{
 		if (word.length() > 35)
 		{
-			user->WriteNumeric(935, chan->name, word, "%word is too long for censor list");
+			user->WriteNumeric(Numerics::InvalidModeParameter(chan, this, word, "Word is too long for the spamfilter list"));
 			return false;
 		}
 
diff --git a/src/modules/m_chanhistory.cpp b/src/modules/m_chanhistory.cpp
index 4d74b65e0..5f081d9de 100644
--- a/src/modules/m_chanhistory.cpp
+++ b/src/modules/m_chanhistory.cpp
@@ -63,18 +63,25 @@ class HistoryMode : public ParamMode<HistoryMode, SimpleExtItem<HistoryList> >
 	{
 		std::string::size_type colon = parameter.find(':');
 		if (colon == std::string::npos)
+		{
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
+		}
 
 		std::string duration(parameter, colon+1);
 		if ((IS_LOCAL(source)) && ((duration.length() > 10) || (!IsValidDuration(duration))))
+		{
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
+		}
 
 		unsigned int len = ConvToInt(parameter.substr(0, colon));
 		unsigned int time = InspIRCd::Duration(duration);
-		if (len == 0)
-			return MODEACTION_DENY;
-		if (len > maxlines && IS_LOCAL(source))
+		if (len == 0 || (len > maxlines && IS_LOCAL(source)))
+		{
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
+		}
 		if (len > maxlines)
 			len = maxlines;
 
diff --git a/src/modules/m_exemptchanops.cpp b/src/modules/m_exemptchanops.cpp
index 52e7c4dad..b1d7b35df 100644
--- a/src/modules/m_exemptchanops.cpp
+++ b/src/modules/m_exemptchanops.cpp
@@ -32,7 +32,7 @@ class ExemptChanOps : public ListModeBase
 		std::string::size_type p = word.find(':');
 		if (p == std::string::npos)
 		{
-			user->WriteNumeric(955, chan->name, word, "Invalid exemptchanops entry, format is <restriction>:<prefix>");
+			user->WriteNumeric(Numerics::InvalidModeParameter(chan, this, word, "Invalid exemptchanops entry, format is <restriction>:<prefix>"));
 			return false;
 		}
 
@@ -45,7 +45,7 @@ class ExemptChanOps : public ListModeBase
 
 		if (!ServerInstance->Modes->FindMode(restriction, MODETYPE_CHANNEL))
 		{
-			user->WriteNumeric(955, chan->name, restriction, "Unknown restriction");
+			user->WriteNumeric(Numerics::InvalidModeParameter(chan, this, word, "Unknown restriction"));
 			return false;
 		}
 
diff --git a/src/modules/m_joinflood.cpp b/src/modules/m_joinflood.cpp
index b4a8f6181..bd9e0ad9e 100644
--- a/src/modules/m_joinflood.cpp
+++ b/src/modules/m_joinflood.cpp
@@ -98,7 +98,7 @@ class JoinFlood : public ParamMode<JoinFlood, SimpleExtItem<joinfloodsettings> >
 		std::string::size_type colon = parameter.find(':');
 		if ((colon == std::string::npos) || (parameter.find('-') != std::string::npos))
 		{
-			source->WriteNumeric(608, channel->name, "Invalid flood parameter");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
 		}
 
@@ -107,7 +107,7 @@ class JoinFlood : public ParamMode<JoinFlood, SimpleExtItem<joinfloodsettings> >
 		unsigned int nsecs = ConvToInt(parameter.substr(colon+1));
 		if ((njoins<1) || (nsecs<1))
 		{
-			source->WriteNumeric(608, channel->name, "Invalid flood parameter");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
 		}
 
diff --git a/src/modules/m_kicknorejoin.cpp b/src/modules/m_kicknorejoin.cpp
index 1bc11948c..67711f766 100644
--- a/src/modules/m_kicknorejoin.cpp
+++ b/src/modules/m_kicknorejoin.cpp
@@ -95,7 +95,10 @@ class KickRejoin : public ParamMode<KickRejoin, SimpleExtItem<KickRejoinData> >
 	{
 		int v = ConvToInt(parameter);
 		if (v <= 0)
+		{
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
+		}
 
 		if ((IS_LOCAL(source) && ((unsigned int)v > max)))
 			v = max;
diff --git a/src/modules/m_messageflood.cpp b/src/modules/m_messageflood.cpp
index 36f2c923b..0707e6ae4 100644
--- a/src/modules/m_messageflood.cpp
+++ b/src/modules/m_messageflood.cpp
@@ -77,7 +77,7 @@ class MsgFlood : public ParamMode<MsgFlood, SimpleExtItem<floodsettings> >
 		std::string::size_type colon = parameter.find(':');
 		if ((colon == std::string::npos) || (parameter.find('-') != std::string::npos))
 		{
-			source->WriteNumeric(608, channel->name, "Invalid flood parameter");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
 		}
 
@@ -88,7 +88,7 @@ class MsgFlood : public ParamMode<MsgFlood, SimpleExtItem<floodsettings> >
 
 		if ((nlines<2) || (nsecs<1))
 		{
-			source->WriteNumeric(608, channel->name, "Invalid flood parameter");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
 		}
 
diff --git a/src/modules/m_nickflood.cpp b/src/modules/m_nickflood.cpp
index e3b448871..50e2b3d93 100644
--- a/src/modules/m_nickflood.cpp
+++ b/src/modules/m_nickflood.cpp
@@ -95,7 +95,7 @@ class NickFlood : public ParamMode<NickFlood, SimpleExtItem<nickfloodsettings> >
 		std::string::size_type colon = parameter.find(':');
 		if ((colon == std::string::npos) || (parameter.find('-') != std::string::npos))
 		{
-			source->WriteNumeric(608, channel->name, "Invalid flood parameter");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
 		}
 
@@ -105,7 +105,7 @@ class NickFlood : public ParamMode<NickFlood, SimpleExtItem<nickfloodsettings> >
 
 		if ((nnicks<1) || (nsecs<1))
 		{
-			source->WriteNumeric(608, channel->name, "Invalid flood parameter");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter));
 			return MODEACTION_DENY;
 		}
 
diff --git a/src/modules/m_repeat.cpp b/src/modules/m_repeat.cpp
index a57e96740..3e974c221 100644
--- a/src/modules/m_repeat.cpp
+++ b/src/modules/m_repeat.cpp
@@ -140,18 +140,20 @@ class RepeatMode : public ParamMode<RepeatMode, SimpleExtItem<ChannelSettings> >
 		ChannelSettings settings;
 		if (!ParseSettings(source, parameter, settings))
 		{
-			source->WriteNotice("*** Invalid syntax. Syntax is {[~*]}[lines]:[time]{:[difference]}{:[backlog]}");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter,
+				"Invalid repeat 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");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter,
+				"Invalid repeat syntax. You can't set needed lines higher than backlog."));
 			return MODEACTION_DENY;
 		}
 
 		LocalUser* localsource = IS_LOCAL(source);
-		if ((localsource) && (!ValidateSettings(localsource, settings)))
+		if ((localsource) && (!ValidateSettings(localsource, channel, parameter, settings)))
 			return MODEACTION_DENY;
 
 		ext.set(channel, settings);
@@ -302,11 +304,12 @@ class RepeatMode : public ParamMode<RepeatMode, SimpleExtItem<ChannelSettings> >
 		return true;
 	}
 
-	bool ValidateSettings(LocalUser* source, const ChannelSettings& settings)
+	bool ValidateSettings(LocalUser* source, Channel* channel, const std::string& parameter, const ChannelSettings& settings)
 	{
 		if (settings.Backlog && !ms.MaxBacklog)
 		{
-			source->WriteNotice("*** The server administrator has disabled backlog matching");
+			source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter,
+				"Invalid repeat parameter. The server administrator has disabled backlog matching."));
 			return false;
 		}
 
@@ -315,21 +318,25 @@ class RepeatMode : public ParamMode<RepeatMode, SimpleExtItem<ChannelSettings> >
 			if (settings.Diff > ms.MaxDiff)
 			{
 				if (ms.MaxDiff == 0)
-					source->WriteNotice("*** The server administrator has disabled matching on edit distance");
+					source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter,
+						"Invalid repeat parameter. 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));
+					source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter, InspIRCd::Format(
+						"Invalid repeat parameter. The distance you specified is too great. Maximum allowed is %u.", 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));
+				source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter, InspIRCd::Format(
+					"Invalid repeat parameter. The line number you specified is too great. Maximum allowed is %u.", 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));
+				source->WriteNumeric(Numerics::InvalidModeParameter(channel, this, parameter, InspIRCd::Format(
+					"Invalid repeat parameter. The seconds you specified is too great. Maximum allowed is %u.", ms.MaxSecs)));
 				return false;
 			}
 		}