Remove ValidateParam and rename CanonicalizeParam.

There's basically no safe way to handle a malformed list mode
sent by a remote server without causing a desync. Its probably
for the best if we just only apply validation to locally added
list modes entries.

include/listmode.h

@@ -156,16 +156,7 @@ public:
 	 * @param parameter The parameter that the user specified.
 	 * @return True if the parameter is valid; otherwise, false.
 	 */
-	virtual bool CanonicalizeParam(LocalUser* user, Channel* channel, std::string& parameter);
+	virtual bool ValidateParam(LocalUser* user, Channel* channel, std::string& parameter);
-
-	/** Validate parameters.
-	 * Overridden by implementing module.
-	 * @param user Source user adding the parameter
-	 * @param channel Channel the parameter is being added to
-	 * @param parameter The actual parameter being added
-	 * @return true if the parameter is valid
-	 */
-	virtual bool ValidateParam(User* user, Channel* channel, const std::string& parameter);
 
 	/** @copydoc ModeHandler::OnParameterMissing */
 	void OnParameterMissing(User* user, User* dest, Channel* channel) override;

src/coremods/core_channel/core_channel.h

@@ -114,7 +114,7 @@ private:
 	ExtBan::ManagerRef extbanmgr;
 public:
 	ModeChannelBan(Module* Creator);
-	bool CanonicalizeParam(LocalUser* user, Channel* channel, std::string& parameter) override;
+	bool ValidateParam(LocalUser* user, Channel* channel, std::string& parameter) override;
 };
 
 class ModeChannelKey final

src/coremods/core_channel/modes.cpp

@@ -27,7 +27,7 @@ ModeChannelBan::ModeChannelBan(Module* Creator)
 	syntax = "<mask>";
 }
 
-bool ModeChannelBan::CanonicalizeParam(LocalUser* user, Channel* channel, std::string& parameter)
+bool ModeChannelBan::ValidateParam(LocalUser* user, Channel* channel, std::string& parameter)
 {
 	if (!extbanmgr || !extbanmgr->Canonicalize(parameter))
 		ModeParser::CleanMask(parameter);

src/listmode.cpp

@@ -157,7 +157,7 @@ ModeAction ListModeBase::OnModeChange(User* source, User*, Channel* channel, Mod
 	{
 		// Try to canonicalise the parameter locally.
 		LocalUser* lsource = IS_LOCAL(source);
-		if (lsource && !CanonicalizeParam(lsource, channel, change.param))
+		if (lsource && !ValidateParam(lsource, channel, change.param))
 			return MODEACTION_DENY;
 
 		// If there was no list
@@ -188,27 +188,8 @@ ModeAction ListModeBase::OnModeChange(User* source, User*, Channel* channel, Mod
 			return MODEACTION_DENY;
 		}
 
-		/* Ok, it *could* be allowed, now give someone subclassing us
+		cd->list.emplace_back(change.param, change.set_by.value_or(source->nick), change.set_at.value_or(ServerInstance->Time()));
-		 * a chance to validate the parameter.
+		return MODEACTION_ALLOW;
-		 * The param is passed by reference, so they can both modify it
-		 * and tell us if we allow it or not.
-		 *
-		 * eg, the subclass could:
-		 * 1) allow
-		 * 2) 'fix' parameter and then allow
-		 * 3) deny
-		 */
-		if (ValidateParam(source, channel, change.param))
-		{
-			// And now add the mask onto the list...
-			cd->list.emplace_back(change.param, change.set_by.value_or(source->nick), change.set_at.value_or(ServerInstance->Time()));
-			return MODEACTION_ALLOW;
-		}
-		else
-		{
-			/* If they deny it they have the job of giving an error message */
-			return MODEACTION_DENY;
-		}
 	}
 	else
 	{
@@ -231,12 +212,7 @@ ModeAction ListModeBase::OnModeChange(User* source, User*, Channel* channel, Mod
 	}
 }
 
-bool ListModeBase::CanonicalizeParam(LocalUser* user, Channel* channel, std::string& parameter)
+bool ListModeBase::ValidateParam(LocalUser* user, Channel* channel, std::string& parameter)
-{
-	return true;
-}
-
-bool ListModeBase::ValidateParam(User* user, Channel* channel, const std::string& parameter)
 {
 	return true;
 }

src/modules/m_banexception.cpp

@@ -50,7 +50,7 @@ public:
 		syntax = "<mask>";
 	}
 
-	bool CanonicalizeParam(LocalUser* user, Channel* channel, std::string& parameter) override
+	bool ValidateParam(LocalUser* user, Channel* channel, std::string& parameter) override
 	{
 		if (!extbanmgr || !extbanmgr->Canonicalize(parameter))
 			ModeParser::CleanMask(parameter);

src/modules/m_chanfilter.cpp

@@ -47,8 +47,9 @@ public:
 		syntax = "<pattern>";
 	}
 
-	bool ValidateParam(User* user, Channel* chan, const std::string& parameter) override
+	bool ValidateParam(LocalUser* user, Channel* chan, std::string& parameter) override
 	{
+		// We only enforce the length restriction against local users to avoid causing a desync.
 		if (parameter.length() > maxlen)
 		{
 			user->WriteNumeric(Numerics::InvalidModeParameter(chan, this, parameter, "Entry is too long for the spamfilter list."));

src/modules/m_exemptchanops.cpp

@@ -81,8 +81,9 @@ public:
 		return MOD_RES_DENY;
 	}
 
-	bool ValidateParam(User* user, Channel* chan, const std::string& parameter) override
+	bool ValidateParam(LocalUser* user, Channel* chan, std::string& parameter) override
 	{
+		// We only enforce the format restriction against local users to avoid causing a desync.
 		std::string restriction;
 		std::string prefix;
 		if (!ParseEntry(parameter, restriction, prefix))

src/modules/m_inviteexception.cpp

@@ -48,7 +48,7 @@ public:
 		syntax = "<mask>";
 	}
 
-	bool CanonicalizeParam(LocalUser* user, Channel* channel, std::string& parameter) override
+	bool ValidateParam(LocalUser* user, Channel* channel, std::string& parameter) override
 	{
 		if (!extbanmgr || !extbanmgr->Canonicalize(parameter))
 			ModeParser::CleanMask(parameter);