Add safelist:maxlisters which prevents more than x number of people doing a LIST at the same time.

(as i've just noticed, 500 bots all doing LIST at once can severely lag your ircd)


git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@6658 e03df62e-2008-0410-955e-edbf42e46eb7

2 files changed, 28 insertions, 6 deletions

diff --git a/docs/inspircd.conf.example b/docs/inspircd.conf.example
index 1ea44d1bf..2849650c3 100644
--- a/docs/inspircd.conf.example
+++ b/docs/inspircd.conf.example
@@ -1561,13 +1561,19 @@
 #
 #-#-#-#-#-#-#-#-#-#-# SAFELIST CONFIGURATION -#-#-#-#-#-#-#-#-#-#-#-#-#
 #
-# When using Safelist, you may set the following value, which sets the
-# amount of time in seconds a user must wait between LIST commands.
-# For example, if this is set to 60 (the default) then the user may not
-# /LIST more than once a minute. If not defined, the default value is
-# 60 seconds.
+# When using Safelist, you may set the following values;
 #
-#<safelist throttle="60">
+# The first value, 'throttle', sets the amount of time in seconds a user
+# must wait between LIST commands. For example, if this is set to 60
+# (the default) then the user may not /LIST more than once a minute.
+# If not defined, the default value is 60 seconds.
+#
+# The second value, 'maxlisters', indicates the maximum number of users
+# which may be retrieving a LIST at once. It is not recommended you raise
+# this value, as increasing it too high can make your network vulnerable
+# to floodbots which waste your bandwidth and CPU time with LIST requests.
+#
+#<safelist throttle="60" maxlisters="50">
 
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # SAJOIN module: Adds the /SAJOIN command
diff --git a/src/modules/m_safelist.cpp b/src/modules/m_safelist.cpp
index 1bdfb97bd..45e4dab11 100644
--- a/src/modules/m_safelist.cpp
+++ b/src/modules/m_safelist.cpp
@@ -38,6 +38,8 @@ class ModuleSafeList : public Module
 {
 	time_t ThrottleSecs;
 	size_t ServerNameSize;
+	int global_listing;
+	int LimitList;
  public:
 	ModuleSafeList(InspIRCd* Me) : Module::Module(Me)
 	{
@@ -52,7 +54,9 @@ class ModuleSafeList : public Module
 	{
 		ConfigReader MyConf(ServerInstance);
 		ThrottleSecs = MyConf.ReadInteger("safelist", "throttle", "60", 0, true);
+		LimitList = MyConf.ReadInteger("safelist", "maxlisters", "50", 0, true);
 		ServerNameSize = strlen(ServerInstance->Config->ServerName) + 4;
+		global_listing = 0;
 	}
  
 	virtual Version GetVersion()
@@ -88,6 +92,14 @@ class ModuleSafeList : public Module
 	 */
 	int HandleList(const char** parameters, int pcnt, userrec* user)
 	{
+		if (global_listing >= LimitList)
+		{
+			user->WriteServ("NOTICE %s :*** Server load is currently too heavy. Please try again later.", user->nick);
+			user->WriteServ("321 %s Channel :Users Name",user->nick);
+			user->WriteServ("323 %s :End of channel list.",user->nick);
+			return 1;
+		}
+
 		/* First, let's check if the user is currently /list'ing */
 		ListData *ld;
 		user->GetExt("safelist_cache", ld);
@@ -117,6 +129,7 @@ class ModuleSafeList : public Module
 			DELETE(last_list_time);
 			user->Shrink("safelist_last");
 		}
+
  
 		/*
 		 * start at channel 0! ;)
@@ -130,6 +143,8 @@ class ModuleSafeList : public Module
 
 		user->WriteServ("321 %s Channel :Users Name",user->nick);
 
+		global_listing++;
+
 		return 1;
 	}
 
@@ -185,6 +200,7 @@ class ModuleSafeList : public Module
 			{
 				user->Shrink("safelist_cache");
 				DELETE(ld);
+				global_listing--;
 			}
 		}
 	}