Add m_ircv3_echomessage which implements the IRCv3.2 echo-message extension

docs/conf/modules.conf.example

@@ -981,6 +981,13 @@
 # extension will get the chghost message and won't see host cycling.
 #<module name="ircv3_chghost">
 
+#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
+# IRCv3 echo-message module: Provides the echo-message IRCv3.2
+# extension which allows capable clients to get an acknowledgement when
+# their messages are delivered and learn what modifications, if any,
+# were applied to them.
+#<module name="ircv3_echomessage">
+
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # Join flood module: Adds support for join flood protection +j X:Y.
 # Closes the channel for 60 seconds if X users join in Y seconds.

src/modules/m_ircv3_echomessage.cpp

@@ -0,0 +1,70 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2015 Attila Molnar <attilamolnar@hush.com>
+ *   Copyright (C) 2013-2015 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"
+#include "modules/cap.h"
+
+static const char* MessageTypeStringSp[] = { "PRIVMSG ", "NOTICE " };
+
+class ModuleIRCv3EchoMessage : public Module
+{
+	Cap::Capability cap;
+
+ public:
+	ModuleIRCv3EchoMessage()
+		: cap(this, "echo-message")
+	{
+	}
+
+	void OnUserMessage(User* user, void* dest, int target_type, const std::string& text, char status, const CUList& exempt_list, MessageType msgtype) CXX11_OVERRIDE
+	{
+		if (!cap.get(user))
+			return;
+
+		std::string msg = MessageTypeStringSp[msgtype];
+		if (target_type == TYPE_USER)
+		{
+			User* destuser = static_cast<User*>(dest);
+			msg.append(destuser->nick);
+		}
+		else if (target_type == TYPE_CHANNEL)
+		{
+			if (status)
+				msg.push_back(status);
+
+			Channel* chan = static_cast<Channel*>(dest);
+			msg.append(chan->name);
+		}
+		else
+		{
+			const char* servername = static_cast<const char*>(dest);
+			msg.append(servername);
+		}
+		msg.append(" :").append(text);
+		user->WriteFrom(user, msg);
+	}
+
+	Version GetVersion() CXX11_OVERRIDE
+	{
+		return Version("Provides the echo-message IRCv3.2 extension", VF_VENDOR);
+	}
+};
+
+MODULE_INIT(ModuleIRCv3EchoMessage)