Backport: Add m_commonchans.so (documented in example conf, no wiki yet) resolves bug #342 feature request by Casey

git-svn-id: http://svn.inspircd.org/repository/branches/1_1_stable@7833 e03df62e-2008-0410-955e-edbf42e46eb7

docs/inspircd.conf.example

@@ -1360,6 +1360,12 @@
 # command is issued, use with care.
 #<module name="m_clones.so">
 
+#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
+# Common channels module: Adds user mode +c, which, when set, requires
+# that users must share a common channel with you to PRIVMSG or NOTICE
+# you.
+#<module name="m_commonchans.so">
+
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # Conn-Join: Allows you to force users to join one or more channels
 # automatically upon connecting to the server.

src/modules/m_commonchans.cpp

@@ -0,0 +1,102 @@
+/*       +------------------------------------+
+ *       | Inspire Internet Relay Chat Daemon |
+ *       +------------------------------------+
+ *
+ *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
+ * See: http://www.inspircd.org/wiki/index.php/Credits
+ *
+ * This program is free but copyrighted software; see
+ *            the file COPYING for details.
+ *
+ * ---------------------------------------------------
+ */
+
+#include "inspircd.h"
+#include <stdio.h>
+#include <string>
+#include "users.h"
+#include "channels.h"
+#include "modules.h"
+#include "configreader.h"
+
+/* $ModDesc: Adds user mode +c, which if set, users must be on a common channel with you to private message you */
+
+/** Handles user mode +c
+ */
+class PrivacyMode : public ModeHandler
+{
+ public:
+	PrivacyMode(InspIRCd* Instance) : ModeHandler(Instance, 'c', 0, 0, false, MODETYPE_USER, false) { }
+
+	ModeAction OnModeChange(userrec* source, userrec* dest, chanrec* channel, std::string &parameter, bool adding)
+	{
+		if (adding)
+		{
+			if (!dest->IsModeSet('c'))
+			{
+				dest->SetMode('c',true);
+				return MODEACTION_ALLOW;
+			}
+		}
+		else
+		{
+			if (dest->IsModeSet('c'))
+			{
+				dest->SetMode('c',false);
+				return MODEACTION_ALLOW;
+			}
+		}
+		
+		return MODEACTION_DENY;
+	}
+};
+
+class ModulePrivacyMode : public Module
+{
+	PrivacyMode* pm;
+ public:
+	ModulePrivacyMode(InspIRCd* Me) : Module(Me)
+	{
+		pm = new PrivacyMode(ServerInstance);
+		if (!ServerInstance->AddMode(pm, 'c'))
+			throw ModuleException("Could not add new modes!");
+	}
+
+	void Implements(char* List)
+	{
+		List[I_OnUserPreMessage] = List[I_OnUserPreNotice] = 1;
+	}
+	
+	virtual ~ModulePrivacyMode()
+	{
+		ServerInstance->Modes->DelMode(pm);
+		DELETE(pm);
+	}
+	
+	virtual Version GetVersion()
+	{
+		return Version(1,1,0,0, VF_COMMON|VF_VENDOR, API_VERSION);
+	}
+
+	virtual int OnUserPreMessage(userrec* user,void* dest,int target_type, std::string &text, char status, CUList &exempt_list)
+	{
+		if (target_type == TYPE_USER)
+		{
+			userrec* t = (userrec*)dest;
+			if (!IS_OPER(user) && (t->IsModeSet('c')) && (!ServerInstance->ULine(user->server)) && !user->SharesChannelWith(t))
+			{
+				user->WriteServ("531 %s %s :You are not permitted to send private messages to this user (+c set)", user->nick, t->nick);
+				return 1;
+			}
+		}
+		return 0;
+	}
+
+	virtual int OnUserPreNotice(userrec* user,void* dest,int target_type, std::string &text, char status, CUList &exempt_list)
+	{
+		return OnUserPreMessage(user, dest, target_type, text, status, exempt_list);
+	}
+};
+
+
+MODULE_INIT(ModulePrivacyMode)