Move the <disabled> tag out of the core to a new module.

11 files changed, 229 insertions, 138 deletions

diff --git a/docs/conf/inspircd.conf.example b/docs/conf/inspircd.conf.example
index f2db74500..890c9cc4c 100644
--- a/docs/conf/inspircd.conf.example
+++ b/docs/conf/inspircd.conf.example
@@ -520,25 +520,6 @@
 # up to 100 entries.
 <maxlist chan="*" limit="100">
 
-#-#-#-#-#-#-#-#-#-#-#-  DISABLED FEATURES  -#-#-#-#-#-#-#-#-#-#-#-#-#-#
-#                                                                     #
-# This tag is optional, and specifies one or more features which are  #
-# not available to non-operators.                                     #
-#                                                                     #
-# For example you may wish to disable NICK and prevent non-opers from #
-# changing their nicknames.                                           #
-# Note that any disabled commands take effect only after the user has #
-# 'registered' (e.g. after the initial USER/NICK/PASS on connection)  #
-# so for example disabling NICK will not cripple your network.        #
-#                                                                     #
-# You can also define if you want to disable any channelmodes         #
-# or usermodes from your users.                                       #
-#                                                                     #
-# `fakenonexistant' will make the ircd pretend that nonexistant       #
-# commands simply don't exist to non-opers ("no such command").       #
-#                                                                     #
-#<disabled commands="TOPIC MODE" usermodes="" chanmodes="" fakenonexistant="yes">
-
 #-#-#-#-#-#-#-#-#-#-#-#-#-  SERVER OPTIONS   -#-#-#-#-#-#-#-#-#-#-#-#-#
 #                                                                     #
 #   Settings to define which features are usable on your server.      #
diff --git a/docs/conf/modules.conf.example b/docs/conf/modules.conf.example
index 0647f77c0..980d0d6a5 100644
--- a/docs/conf/modules.conf.example
+++ b/docs/conf/modules.conf.example
@@ -765,6 +765,43 @@
 # Glob masks are accepted here also.                                  #
 
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
+# Disable module: Provides support for disabling commands and modes.  #
+#<module name="disable">
+#
+#-#-#-#-#-#-#-#-#-#-#-#- DISABLE CONFIGURATION -#-#-#-#-#-#-#-#-#-#-#-#
+#                                                                     #
+# If you have the disable module loaded then you need to specify the  #
+# commands and modes that you want disabled. Users who have not fully #
+# connected yet are exempt from this module so you can e.g. disable   #
+# the NICK command but still allow users to connect to the server.    #
+#                                                                     #
+# commands - A space-delimited list of commands that can not be used  #
+#            by users. You can exempt server operators from this with #
+#            the servers/use-disabled-commands privilege.             #
+#                                                                     #
+# chanmodes - One or more channel modes that can not be added/removed #
+#             by users. You can exempt server operators from this     #
+#             with the servers/use-disabled-commands privilege.       #
+#                                                                     #
+# usermodes - One or more user modes that can not be added/removed by #
+#             users. You can exempt server operators from this with   #
+#             the servers/use-disabled-commands privilege.            #
+#                                                                     #
+# fakenonexistent - Whether to pretend that a disabled command/mode   #
+#                   does not exist when executed/changed by a user.   #
+#                   Defaults to no.                                   #
+#                                                                     #
+# notifyopers - Whether to send a notice to snomask `a` when a user   #
+#               is prevented from using a disabled command/mode.      #
+#               Defaults to no.                                       #
+#                                                                     #
+#<disabled commands="KICK TOPIC"                                      #
+#          chanmodes="kp"                                             #
+#          usermodes="iw"                                             #
+#          fakenonexistent="yes"                                      #
+#          notifyopers="no">                                          #
+
+#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # DNS blacklist module: Provides support for looking up IPs on one or #
 # more blacklists.                                                    #
 #<module name="dnsbl">                                                #
diff --git a/include/configreader.h b/include/configreader.h
index fd9401c0f..511bedbee 100644
--- a/include/configreader.h
+++ b/include/configreader.h
@@ -332,18 +332,6 @@ class CoreExport ServerConfig
 	 */
 	std::string ServerDesc;
 
-	/** Pretend disabled commands don't exist.
-	 */
-	bool DisabledDontExist;
-
-	/** This variable identifies which usermodes have been diabled.
-	 */
-	std::bitset<64> DisabledUModes;
-
-	/** This variable identifies which chanmodes have been disabled.
-	 */
-	std::bitset<64> DisabledCModes;
-
 	/** How to treat a user in a channel who is banned. */
 	BannedUserTreatment RestrictBannedUsers;
 
@@ -466,9 +454,6 @@ class CoreExport ServerConfig
 
 	void Fill();
 
-	/** Disables the commands specified in <disabled:commands>. */
-	bool ApplyDisabledCommands();
-
 	/** Escapes a value for storage in a configuration key.
 	 * @param str The string to escape.
 	 * @param xml Are we using the XML config format?
diff --git a/include/ctables.h b/include/ctables.h
index 8be40cc54..1c7d5b4bd 100644
--- a/include/ctables.h
+++ b/include/ctables.h
@@ -163,10 +163,6 @@ class CoreExport CommandBase : public ServiceProvider
 	 */
 	unsigned long use_count;
 
-	/** True if the command is disabled to non-opers
-	 */
-	bool disabled;
-
 	/** True if the command can be issued before registering
 	 */
 	bool works_before_reg;
@@ -212,23 +208,6 @@ class CoreExport CommandBase : public ServiceProvider
 	 */
 	virtual void EncodeParameter(std::string& parameter, unsigned int index);
 
-	/** Disable or enable this command.
-	 * @param setting True to disable the command.
-	 */
-	void Disable(bool setting)
-	{
-		disabled = setting;
-	}
-
-	/** Obtain this command's disable state.
-	 * @return true if the command is currently disabled
-	 * (disabled commands can be used only by operators)
-	 */
-	bool IsDisabled()
-	{
-		return disabled;
-	}
-
 	/** @return true if the command works before registration.
 	 */
 	bool WorksBeforeReg()
diff --git a/src/command_parse.cpp b/src/command_parse.cpp
index c2ae39d49..7a732f8b5 100644
--- a/src/command_parse.cpp
+++ b/src/command_parse.cpp
@@ -266,24 +266,6 @@ void CommandParser::ProcessCommand(LocalUser* user, std::string& command, Comman
 		}
 	}
 
-	if ((user->registered == REG_ALL) && (!user->IsOper()) && (handler->IsDisabled()))
-	{
-		/* command is disabled! */
-		user->CommandFloodPenalty += failpenalty;
-		if (ServerInstance->Config->DisabledDontExist)
-		{
-			user->WriteNumeric(ERR_UNKNOWNCOMMAND, command, "Unknown command");
-		}
-		else
-		{
-			user->WriteNumeric(ERR_UNKNOWNCOMMAND, command, "This command has been disabled.");
-		}
-
-		ServerInstance->SNO->WriteToSnoMask('a', "%s denied for %s (%s@%s)",
-				command.c_str(), user->nick.c_str(), user->ident.c_str(), user->GetRealHost().c_str());
-		return;
-	}
-
 	if ((!command_p.empty()) && (command_p.back().empty()) && (!handler->allow_empty_last_param))
 		command_p.pop_back();
 
@@ -333,7 +315,6 @@ CommandBase::CommandBase(Module* mod, const std::string& cmd, unsigned int minpa
 	, min_params(minpara)
 	, max_params(maxpara)
 	, use_count(0)
-	, disabled(false)
 	, works_before_reg(false)
 	, allow_empty_last_param(true)
 	, Penalty(1)
diff --git a/src/configreader.cpp b/src/configreader.cpp
index ce03f1d9e..5a0ceff06 100644
--- a/src/configreader.cpp
+++ b/src/configreader.cpp
@@ -72,31 +72,6 @@ ServerConfig::~ServerConfig()
 	delete EmptyTag;
 }
 
-bool ServerConfig::ApplyDisabledCommands()
-{
-	// Enable everything first.
-	const CommandParser::CommandMap& commands = ServerInstance->Parser.GetCommands();
-	for (CommandParser::CommandMap::const_iterator x = commands.begin(); x != commands.end(); ++x)
-		x->second->Disable(false);
-
-	// Now disable the commands specified in the config.
-	std::string command;
-	irc::spacesepstream commandlist(ConfValue("disabled")->getString("commands"));
-	while (commandlist.GetToken(command))
-	{
-		Command* handler = ServerInstance->Parser.GetHandler(command);
-		if (!handler)
-		{
-			ServerInstance->Logs->Log("CONFIG", LOG_DEBUG, "Unable to disable the %s command as it does not exist!", command.c_str());
-			continue;
-		}
-
-		ServerInstance->Logs->Log("CONFIG", LOG_DEBUG, "The %s command has been disabled", command.c_str());
-		handler->Disable(true);
-	}
-	return true;
-}
-
 static void ReadXLine(ServerConfig* conf, const std::string& tag, const std::string& key, XLineFactory* make)
 {
 	ConfigTagList tags = conf->ConfTags(tag);
@@ -378,7 +353,6 @@ void ServerConfig::Fill()
 	ServerDesc = server->getString("description", "Configure Me");
 	Network = server->getString("network", "Network");
 	NetBufferSize = ConfValue("performance")->getInt("netbuffersize", 10240, 1024, 65534);
-	DisabledDontExist = ConfValue("disabled")->getBool("fakenonexistant");
 	CustomVersion = security->getString("customversion");
 	HideBans = security->getBool("hidebans");
 	HideServer = security->getString("hideserver", security->getString("hidewhois"));
@@ -429,25 +403,6 @@ void ServerConfig::Fill()
 		RestrictBannedUsers =  ServerConfig::BUT_RESTRICT_NOTIFY;
 	else
 		throw CoreException(restrictbannedusers + " is an invalid <options:restrictbannedusers> value, at " + options->getTagLocation());
-
-	DisabledUModes.reset();
-	std::string modes = ConfValue("disabled")->getString("usermodes");
-	for (std::string::const_iterator p = modes.begin(); p != modes.end(); ++p)
-	{
-		// Complain when the character is not a valid mode character.
-		if (!ModeParser::IsModeChar(*p))
-			throw CoreException("Invalid usermode " + std::string(1, *p) + " was found.");
-		DisabledUModes.set(*p - 'A');
-	}
-
-	DisabledCModes.reset();
-	modes = ConfValue("disabled")->getString("chanmodes");
-	for (std::string::const_iterator p = modes.begin(); p != modes.end(); ++p)
-	{
-		if (!ModeParser::IsModeChar(*p))
-			throw CoreException("Invalid chanmode " + std::string(1, *p) + " was found.");
-		DisabledCModes.set(*p - 'A');
-	}
 }
 
 // WARNING: it is not safe to use most of the codebase in this function, as it
@@ -723,7 +678,6 @@ void ConfigReaderThread::Finish()
 		ServerInstance->Users.RehashCloneCounts();
 		ServerInstance->XLines->CheckELines();
 		ServerInstance->XLines->ApplyLines();
-		Config->ApplyDisabledCommands();
 		User* user = ServerInstance->FindNick(TheUserUID);
 
 		ConfigStatus status(user);
diff --git a/src/inspircd.cpp b/src/inspircd.cpp
index 7e299700b..09e48ea1f 100644
--- a/src/inspircd.cpp
+++ b/src/inspircd.cpp
@@ -442,7 +442,6 @@ InspIRCd::InspIRCd(int argc, char** argv) :
 
 	// Build ISupport as ModuleManager::LoadAll() does not do it
 	this->ISupport.Build();
-	Config->ApplyDisabledCommands();
 
 	if (!pl.empty())
 	{
diff --git a/src/mode.cpp b/src/mode.cpp
index 5793b4e66..459eb21c8 100644
--- a/src/mode.cpp
+++ b/src/mode.cpp
@@ -312,17 +312,6 @@ ModeAction ModeParser::TryMode(User* user, User* targetuser, Channel* chan, Mode
 		}
 	}
 
-	if (IS_LOCAL(user) && !user->IsOper())
-	{
-		const std::bitset<64>& disabled = (type == MODETYPE_CHANNEL) ? ServerInstance->Config->DisabledCModes : ServerInstance->Config->DisabledUModes;
-		if (disabled.test(modechar - 'A'))
-		{
-			user->WriteNumeric(ERR_NOPRIVILEGES, InspIRCd::Format("Permission Denied - %s mode %c has been locked by the administrator",
-				type == MODETYPE_CHANNEL ? "channel" : "user", modechar));
-			return MODEACTION_DENY;
-		}
-	}
-
 	if ((adding) && (IS_LOCAL(user)) && (mh->NeedsOper()) && (!user->HasModePermission(mh)))
 	{
 		/* It's an oper only mode, and they don't have access to it. */
diff --git a/src/modules/m_conn_umodes.cpp b/src/modules/m_conn_umodes.cpp
index 1f2fe7455..3132aed40 100644
--- a/src/modules/m_conn_umodes.cpp
+++ b/src/modules/m_conn_umodes.cpp
@@ -38,10 +38,6 @@ class ModuleModesOnConnect : public Module
 
 	void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 	{
-		// Backup and zero out the disabled usermodes, so that we can override them here.
-		const std::bitset<64> save = ServerInstance->Config->DisabledUModes;
-		ServerInstance->Config->DisabledUModes.reset();
-
 		ConfigTag* tag = user->MyClass->config;
 		std::string ThisModes = tag->getString("modes");
 		if (!ThisModes.empty())
@@ -58,8 +54,6 @@ class ModuleModesOnConnect : public Module
 
 			ServerInstance->Parser.CallHandler("MODE", modes, user);
 		}
-
-		ServerInstance->Config->DisabledUModes = save;
 	}
 };
 
diff --git a/src/modules/m_disable.cpp b/src/modules/m_disable.cpp
new file mode 100644
index 000000000..203f9ee64
--- /dev/null
+++ b/src/modules/m_disable.cpp
@@ -0,0 +1,189 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2019 Peter Powell <petpow@saberuk.com>
+ *
+ * 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"
+
+enum
+{
+	// From ircu.
+	ERR_DISABLED = 517
+};
+
+// Holds a list of disabled commands.
+typedef std::vector<std::string> CommandList;
+
+// Holds whether modes are disabled or not.
+typedef std::bitset<64> ModeStatus;
+
+class ModuleDisable : public Module
+{
+ private:
+	CommandList commands;
+	ModeStatus chanmodes;
+	bool fakenonexistent;
+	bool notifyopers;
+	ModeStatus usermodes;
+
+	void ReadModes(ConfigTag* tag, const std::string& field, ModeType type, ModeStatus& status)
+	{
+		const std::string modes = tag->getString(field);
+		for (std::string::const_iterator iter = modes.begin(); iter != modes.end(); ++iter)
+		{
+			const char& chr = *iter;
+
+			// Check that the character is a valid mode letter.
+			if (!ModeParser::IsModeChar(chr))
+				throw ModuleException(InspIRCd::Format("Invalid mode '%c' was specified in <disabled:%s> at %s",
+					chr, field.c_str(), tag->getTagLocation().c_str()));
+
+			// Check that the mode actually exists.
+			ModeHandler* mh = ServerInstance->Modes->FindMode(chr, type);
+			if (!chr)
+				throw ModuleException(InspIRCd::Format("Non-existent mode '%c' was specified in <disabled:%s> at %s",
+					chr, field.c_str(), tag->getTagLocation().c_str()));
+
+			// Disable the mode.
+			ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "The %c (%s) %s mode has been disabled",
+				mh->GetModeChar(), mh->name.c_str(), type == MODETYPE_CHANNEL ? "channel" : "user");
+			status.set(chr - 'A');
+		}
+	}
+
+	void WriteLog(const char* message, ...) CUSTOM_PRINTF(2, 3)
+	{
+		std::string buffer;
+		VAFORMAT(buffer, message, message);
+
+		if (notifyopers)
+			ServerInstance->SNO->WriteToSnoMask('a', buffer);
+		else
+			ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, buffer);
+	}
+
+ public:
+	void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
+	{
+		ConfigTag* tag = ServerInstance->Config->ConfValue("disabled");
+
+		// Parse the disabled commands.
+		CommandList newcommands;
+		irc::spacesepstream commandlist(tag->getString("commands"));
+		for (std::string command; commandlist.GetToken(command); )
+		{
+			// Check that the command actually exists.
+			Command* handler = ServerInstance->Parser.GetHandler(command);
+			if (!handler)
+				throw ModuleException(InspIRCd::Format("Non-existent command '%s' was specified in <disabled:commands> at %s",
+					command.c_str(), tag->getTagLocation().c_str()));
+
+			// Prevent admins from disabling COMMANDS and MODULES for transparency reasons.
+			if (handler->name == "COMMANDS" || handler->name == "MODULES")
+				continue;
+
+			// Disable the command.
+			ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "The %s command has been disabled", handler->name.c_str());
+			newcommands.push_back(handler->name);
+		}
+
+		// Parse the disabled channel modes.
+		ModeStatus newchanmodes;
+		ReadModes(tag, "chanmodes", MODETYPE_CHANNEL, newchanmodes);
+
+		// Parse the disabled user modes.
+		ModeStatus newusermodes;
+		ReadModes(tag, "usermodes", MODETYPE_USER, newusermodes);
+
+		// The server config was valid so we can use these now.
+		chanmodes = newchanmodes;
+		usermodes = newusermodes;
+		commands.swap(newcommands);
+
+		// Whether we should fake the non-existence of disabled things.
+		fakenonexistent = tag->getBool("fakenonexistent", tag->getBool("fakenonexistant"));
+
+		// Whether to notify server operators via snomask `a` about the attempted use of disabled commands/modes.
+		notifyopers = tag->getBool("notifyopers");
+	}
+
+	ModResult OnPreCommand(std::string& command, CommandBase::Params& parameters, LocalUser* user, bool validated) CXX11_OVERRIDE
+	{
+		// If a command is unvalidated or the source is not registered we do nothing.
+		if (!validated || user->registered != REG_ALL)
+			return MOD_RES_PASSTHRU;
+
+		// If the command is not disabled or the user has the servers/use-disabled-commands priv we do nothing.
+		if (!stdalgo::isin(commands, command) || user->HasPrivPermission("servers/use-disabled-commands"))
+			return MOD_RES_PASSTHRU;
+
+		// The user has tried to execute a disabled command!
+		user->CommandFloodPenalty += 2000;
+		WriteLog("%s was blocked from executing the disabled %s command", user->GetFullRealHost().c_str(), command.c_str());
+
+		if (fakenonexistent)
+		{
+			// The server administrator has specified that disabled commands should be
+			// treated as if they do not exist.
+			user->WriteNumeric(ERR_UNKNOWNCOMMAND, command, "Unknown command");
+			ServerInstance->stats.Unknown++;
+			return MOD_RES_DENY;
+		}
+
+		// Inform the user that the command they executed has been disabled.
+		user->WriteNumeric(ERR_DISABLED, command, "Command disabled");
+		return MOD_RES_DENY;
+	}
+
+	ModResult OnRawMode(User* user, Channel* chan, ModeHandler* mh, const std::string& param, bool adding) CXX11_OVERRIDE
+	{
+		// If a mode change is remote or the source is not registered we do nothing.
+		if (!IS_LOCAL(user) || user->registered != REG_ALL)
+			return MOD_RES_PASSTHRU;
+
+		// If the mode is not disabled or the user has the servers/use-disabled-modes priv we do nothing.
+		const std::bitset<64>& disabled = (mh->GetModeType() == MODETYPE_CHANNEL) ? chanmodes : usermodes;
+		if (!disabled.test(mh->GetModeChar() - 'A') || user->HasPrivPermission("servers/use-disabled-modes"))
+			return MOD_RES_PASSTHRU;
+
+		// The user has tried to change a disabled mode!
+		const char* what = mh->GetModeType() == MODETYPE_CHANNEL ? "channel" : "user";
+		WriteLog("%s was blocked from executing the disabled %s mode %c (%s)",
+			user->GetFullRealHost().c_str(), what, mh->GetModeChar(), mh->name.c_str());
+
+		if (fakenonexistent)
+		{
+			// The server administrator has specified that disabled modes should be
+			// treated as if they do not exist.
+			user->WriteNumeric(mh->GetModeType() == MODETYPE_CHANNEL ? ERR_UNKNOWNMODE : ERR_UNKNOWNSNOMASK,
+				mh->GetModeChar(), "is unknown mode char to me");
+			return MOD_RES_DENY;
+		}
+
+		// Inform the user that the mode they changed has been disabled.
+		user->WriteNumeric(ERR_NOPRIVILEGES, InspIRCd::Format("Permission Denied - %s mode %c (%s) is disabled",
+			what, mh->GetModeChar(), mh->name.c_str()));
+		return MOD_RES_DENY;
+	}
+
+	Version GetVersion() CXX11_OVERRIDE
+	{
+		return Version("Provides support for disabling commands and modes", VF_VENDOR);
+	}
+};
+
+MODULE_INIT(ModuleDisable)
diff --git a/src/modules/m_samode.cpp b/src/modules/m_samode.cpp
index 8f28a7e9c..db3345b98 100644
--- a/src/modules/m_samode.cpp
+++ b/src/modules/m_samode.cpp
@@ -124,6 +124,9 @@ class ModuleSaMode : public Module
 
 	void Prioritize() CXX11_OVERRIDE
 	{
+		Module* disabled = ServerInstance->Modules->Find("m_disabled.so");
+		ServerInstance->Modules->SetPriority(this, I_OnRawMode, PRIORITY_BEFORE, disabled);
+
 		Module *override = ServerInstance->Modules->Find("m_override.so");
 		ServerInstance->Modules->SetPriority(this, I_OnPreMode, PRIORITY_BEFORE, override);
 	}