commit c3c737ed3862b046ae518563fdee1340ab014768
Author: SmallJoker <st.rentsch@hotmail.com>
Date:   Wed Jul 16 11:55:37 2014 +0200

    Upload. Needs testing

diff --git a/depends.txt b/depends.txt
new file mode 100644
index 0000000..e69de29
diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..d61ab36
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,103 @@
+-- Created by Krock to stop mass-account-creators
+-- License: WTFPL
+ipnames = {}
+ipnames.data = {}
+ipnames.tmp_data = {}
+ipnames.changes = false
+ipnames.save_interval = 480
+ipnames.save_time = 0
+ipnames.file = minetest.get_worldpath().."/ipnames.data"
+
+ipnames.name_per_ip_limit = 3
+
+-- Get accounts self.
+minetest.register_chatcommand("whois", {
+	description = "Gets all player names which have the same IP as <param>.",
+	privs = {ban=true},
+	func = function(name, param)
+		if not ipnames.data[param] then
+			minetest.chat_send_player(name, "The player '"..param.."' did not join yet.")
+			return
+		end
+		
+		local ip = ipnames.data[param]
+		local names = "";
+		for k, v in pairs(ipnames.data) do
+			if v == ip then
+				names = names.." "..k
+			end
+		end
+		minetest.chat_send_player(name, "Following players share an IP: "..names)
+	end,
+})
+
+-- Get IP if player tries to join, ban if there are too much names per IP
+minetest.register_on_prejoinplayer(function(name, ip)
+	-- Only stop new accounts
+	ipnames.tmp_data[name] = ip
+	if not ipnames.data[name] then
+		local count = 1
+		local names = ""
+		for k, v in pairs(ipnames.data) do
+			if v == ip then
+				count = count + 1
+				names = names..k..", "
+			end
+		end
+		if count > ipnames.name_per_ip_limit then
+			ipnames.tmp_data[name] = nil
+			return ("\nYou exceeded the limit of accounts.\nYou already own the following accounts:\n"..names)
+		end
+	end
+end)
+
+-- Save IP if player joined
+minetest.register_on_joinplayer(function(player)
+	local name = player:get_player_name()
+	ipnames.data[name] = ipnames.tmp_data[name]
+	ipnames.tmp_data[name] = nil
+	ipnames.changes = true
+end)
+
+function ipnames.load_data()
+	local file = io.open(ipnames.file, "r")
+	if not file then
+		return
+	end
+	for line in file:lines() do
+		if line ~= "" then
+			local data = line:split("|")
+			if #data >= 2 then
+				ipnames.data[data[1]] = data[2]
+			end
+		end
+	end
+	io.close(file)
+end
+
+function ipnames.save_data()
+	if not ipnames.changes then
+		return
+	end
+	ipnames.changes = false
+	local file = io.open(ipnames.file, "w")
+	for i, v in pairs(ipnames.data) do
+		if v ~= nil then
+			file:write(i.."|"..v.."\n")
+		end
+	end
+	io.close(file)
+end
+
+minetest.register_globalstep(function(t)
+	ipnames.save_time = ipnames.save_time + t
+	if ipnames.save_time < ipnames.save_interval then
+		return
+	end
+	ipnames.save_time = 0
+	ipnames.save_data()
+end)
+
+minetest.register_on_shutdown(function() ipnames.save_data() end)
+
+minetest.after(3, function() ipnames.load_data() end)
\ No newline at end of file