From 8695476bebaea7469ea1aaf4c13ec8e020353d39 Mon Sep 17 00:00:00 2001
From: Diego Martinez <kaeza@users.sf.net>
Date: Mon, 19 May 2014 23:23:43 -0300
Subject: [PATCH] First commit.

---
 doc/API.md       |  32 ++++++
 doc/dbformat.txt |  45 ++++++++
 init.lua         | 271 +++++++++++++++++++++++++++++++++++++++++++++++
 serialize.lua    |  31 ++++++
 shutil.lua       |  42 ++++++++
 5 files changed, 421 insertions(+)
 create mode 100644 doc/API.md
 create mode 100644 doc/dbformat.txt
 create mode 100644 init.lua
 create mode 100644 serialize.lua
 create mode 100644 shutil.lua

diff --git a/doc/API.md b/doc/API.md
new file mode 100644
index 0000000..bee7c42
--- /dev/null
+++ b/doc/API.md
@@ -0,0 +1,32 @@
+
+## Extended Ban Mod API
+
+### ban_player
+
+`xban.ban_player(player_or_ip, source, expires, reason)`
+
+Ban a player and all of his/her alternative names and IPs.
+
+#### Arguments:
+
+* `player_or_ip` - Player to search for and ban. See note 1 below.
+* `source` - Source of the ban. See note 2 below.
+* `expires` - Time at which the ban expires. If nil, ban is permanent.
+* `reason` - Reason for ban.
+
+### unban_player
+
+`xban.unban_player(player_or_ip, source)`
+
+Unban a player and all of his/her alternative names and IPs.
+
+#### Arguments:
+
+* `player_or_ip` - Player to search for and unban.
+* `source` - Source of the ban. See note 2 below.
+
+### Notes
+
+* 1: If player is currently online, all his accounts are kicked.
+* 2: Mods using the xban API are advised to use the `"modname:source"`
+format for `source` (for example: `"anticheat:main"`).
diff --git a/doc/dbformat.txt b/doc/dbformat.txt
new file mode 100644
index 0000000..71b25a5
--- /dev/null
+++ b/doc/dbformat.txt
@@ -0,0 +1,45 @@
+
+Database is a regular Lua script that returns a table.
+
+Table has a single named field `timestamp' containing the time_t the
+DB was last saved. It's not used in the mod and is only meant for
+external use (I don't find filesystem timestamps too reliable).
+
+Next is a simple array (number indices) of entries.
+
+Each entry contains following fields:
+
+[1] = {
+	-- Names/IPs associated with this entry
+	names = {
+		["foo"] = true,
+		["bar"] = true,
+		["123.45.67.89"] = true,
+	},
+	banned = true,      -- Whether this user is banned
+	                    -- Other fields do not apply if false
+	time = 12341234,    -- Time of last ban (*1)
+	expires = 43214321  -- Time at which ban expires (*2)
+	                    -- If nil, permanent ban
+	reason = "asdf",    -- Reason for ban
+	source = "qwerty",  -- Source of ban (*2)
+	record = {
+		[1] = {
+			source = "asdf",
+			reason = "qwerty",
+			time = 12341234,
+			expires = 43214321,
+		},
+		[1] = {
+			source = "asdf",
+			reason = "Unbanned",  -- When unbanned
+			time = 12341234,
+		},
+	},
+}
+
+Notes:
+(*1)  All times are expressed in whatever unit `os.time()' uses
+      (`time_t' on most (all?) systems).
+(*2)  Mods using the xban API are advised to use the "modname:source"
+      format for `source' (for example: "anticheat:main").
diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..ef6143e
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,271 @@
+
+xban = { }
+
+local MP = minetest.get_modpath(minetest.get_current_modname())
+
+dofile(MP.."/serialize.lua")
+dofile(MP.."/shutil.lua")
+
+local db = { }
+local tempbans = { }
+
+local DEF_SAVE_INTERVAL = 300 -- 5 minutes
+local DEF_DB_FILENAME = minetest.get_worldpath().."/xban.db"
+
+local DB_FILENAME = minetest.setting_get("xban.db_filename")
+local SAVE_INTERVAL = tonumber(
+  minetest.setting_get("xban.db_save_interval")) or DEF_SAVE_INTERVAL
+
+if (not DB_FILENAME) or (DB_FILENAME == "") then
+	DB_FILENAME = DEF_DB_FILENAME
+end
+
+local function make_logger(level)
+	return function(text, ...)
+		minetest.log(level, "[xban] "..text:format(...))
+	end
+end
+
+local ACTION = make_logger("action")
+local INFO = make_logger("info")
+local WARNING = make_logger("warning")
+local ERROR = make_logger("error")
+
+local unit_to_secs = {
+	s = 1, m = 60, h = 3600,
+	D = 86400, W = 604800, M = 2592000, Y = 31104000,
+	[""] = 1,
+}
+
+local function parse_time(t) --> secs
+	local secs = 0
+	for num, unit in t:gmatch("(%d+)([smhDWMY]?)") do
+		secs = secs + (tonumber(num) * (unit_to_secs[unit] or 1))
+	end
+	return secs
+end
+
+function xban.find_entry(player, create) --> entry, index
+	for index, e in ipairs(db) do
+		for name in pairs(e.names) do
+			if name == player then
+				return e, index
+			end
+		end
+	end
+	if create then
+		local e = {
+			names = { [player]=true },
+			banned = false,
+			record = { },
+		}
+		table.insert(db, e)
+		return e, #db
+	end
+	return nil
+end
+
+function xban.get_info(player) --> ip_name_list, banned, last_record
+	local e = xban.find_entry(player)
+	if not e then
+		return nil, "No such entry"
+	end
+	return e.names, e.banned, e.record[#e.record]
+end
+
+function xban.ban_player(player, source, expires, reason) --> bool, err
+	local e = xban.find_entry(player, true)
+	local rec = {
+		source = source,
+		time = os.time(),
+		expires = expires,
+		reason = reason,
+	}
+	table.insert(e.record, rec)
+	e.names[player] = true
+	local pl = minetest.get_player_by_name(player)
+	if pl then
+		local ip = minetest.get_player_ip(player)
+		if ip then
+			e.names[ip] = true
+		end
+	end
+	e.reason = reason
+	e.time = rec.time
+	e.expires = expires
+	e.banned = true
+	local msg
+	local date = (expires and os.date("%c", expires)
+	  or "the end of time")
+	if expires then
+		table.insert(tempbans, e)
+		msg = ("Banned: Expires: %s, Reason: %s"):format(date, reason)
+	else
+		msg = ("Banned: Reason: %s"):format(reason)
+	end
+	for nm in pairs(e.names) do
+		minetest.kick_player(nm, msg)
+	end
+	ACTION("%s bans %s until %s for reason: %s", source, player,
+	  date, reason)
+	ACTION("Banned Names/IPs: %s", table.concat(e.names, ", "))
+	return true
+end
+
+function xban.unban_player(player, source) --> bool, err
+	local e = xban.find_entry(player)
+	if not e then
+		return nil, "No such entry"
+	end
+	local rec = {
+		source = source,
+		time = os.time(),
+		reason = "Unbanned",
+	}
+	table.insert(e.record, rec)
+	e.banned = false
+	e.reason = nil
+	e.expires = nil
+	e.time = nil
+	ACTION("%s unbans %s", source, player)
+	ACTION("Unbanned Names/IPs: %s", table.concat(e.names, ", "))
+	return true
+end
+
+minetest.register_on_prejoinplayer(function(name, ip)
+	local e = xban.find_entry(name) or xban.find_entry(ip, true)
+	e.names[name] = true
+	e.names[ip] = true
+	if e.banned then
+		local date = (e.expires and os.date("%c", e.expires)
+		  or "the end of time")
+		return ("Banned: Expires: %s, Reason: %s"):format(
+		  date, e.reason)
+	end
+end)
+
+minetest.register_chatcommand("xban", {
+	description = "XBan a player",
+	params = "<player> <reason>",
+	privs = { ban=true },
+	func = function(name, params)
+		local plname, reason = params:match("(%S+)%s+(.+)")
+		if not (plname and reason) then
+			minetest.chat_send_player(name,
+			  "Usage: /xban <player> <reason>")
+			return
+		end
+		xban.ban_player(plname, name, nil, reason)
+		minetest.chat_send_player(name,
+		  ("Banned %s."):format(plname))
+	end,
+})
+
+minetest.register_chatcommand("xtempban", {
+	description = "XBan a player temporarily",
+	params = "<player> <time> <reason>",
+	privs = { ban=true },
+	func = function(name, params)
+		local plname, time, reason = params:match("(%S+)%s+(%S+)%s+(.+)")
+		if not (plname and time and reason) then
+			minetest.chat_send_player(name,
+			  "Usage: /xtempban <player> <time> <reason>")
+			return
+		end
+		time = parse_time(time)
+		if time < 60 then
+			minetest.chat_send_player(name,
+			  "You must ban for at least 60 seconds.")
+			return
+		end
+		local expires = os.time() + time
+		xban.ban_player(plname, name, expires, reason)
+		minetest.chat_send_player(name,
+		  ("Banned %s until %s."):format(
+		  plname, os.date("%c", expires)))
+	end,
+})
+
+minetest.register_chatcommand("xunban", {
+	description = "XUnBan a player",
+	params = "<player_or_ip>",
+	privs = { ban=true },
+	func = function(name, params)
+		local plname = params:match("%S+")
+		if not plname then
+			minetest.chat_send_player(name,
+			  "Usage: /xunban <player_or_ip>")
+			return
+		end
+		local ok, e = xban.unban_player(plname, name)
+		minetest.chat_send_player(name,
+		  ("Unbanned %s."):format(plname))
+	end,
+})
+
+local function check_temp_bans()
+	minetest.after(60, check_temp_bans)
+	local to_rm = { }
+	local now = os.time()
+	for i, e in ipairs(tempbans) do
+		if e.expires and (e.expires <= now) then
+			table.insert(to_rm, i)
+			e.banned = false
+			e.expires = nil
+			e.reason = nil
+			e.time = nil
+		end
+	end
+	for _, i in ipairs(to_rm) do
+		table.remove(tempbans, i)
+	end
+end
+
+local function save_db()
+	minetest.after(SAVE_INTERVAL, save_db)
+	local ok
+	local f, e = io.open(DB_FILENAME, "wt")
+	db.timestamp = os.time()
+	if f then
+		ok, e = f:write(xban.serialize(db))
+		WARNING("Unable to save database: %s", e)
+	end
+	if f then f:close() end
+	return
+end
+
+local function load_db()
+	local f, e = io.open(DB_FILENAME, "rt")
+	if not f then
+		WARNING("Unable to load database: %s", e)
+		return
+	end
+	local cont
+	cont, e = f:read("*a")
+	if not cont then
+		WARNING("Unable to load database: %s", e)
+		return
+	end
+	local t = minetest.deserialize(cont)
+	if not t then
+		WARNING("Unable to load database: %s",
+		  "Deserialization failed")
+		return
+	end
+	db = t
+	tempbans = { }
+	for _, entry in ipairs(db) do
+		if entry.banned and entry.expires then
+			table.insert(tempbans, entry)
+		end
+	end
+end
+
+-- Backup database
+shutil.copy_file(DB_FILENAME,
+  DB_FILENAME.."."..os.date("%Y%m%d%H%M%S"))
+
+minetest.register_on_shutdown(save_db)
+minetest.after(SAVE_INTERVAL, save_db)
+load_db()
+xban.db = db
diff --git a/serialize.lua b/serialize.lua
new file mode 100644
index 0000000..d9177d9
--- /dev/null
+++ b/serialize.lua
@@ -0,0 +1,31 @@
+
+local function repr(x)
+	if type(x) == "string" then
+		return ("%q"):format(x)
+	else
+		return tostring(x)
+	end
+end
+
+local function my_serialize_2(t, level)
+	level = level or 0
+	local lines = { }
+	local indent = ("  "):rep(level)
+	for k, v in pairs(t) do
+		local typ = type(v)
+		if typ == "table" then
+			table.insert(lines,
+			  indent..("[%s] = {\n"):format(repr(k))
+			  ..my_serialize_2(v, level + 1).."\n"
+			  ..indent.."},")
+		else
+			table.insert(lines,
+			  indent..("[%s] = %s,"):format(repr(k), repr(v)))
+		end
+	end
+	return table.concat(lines, "\n")
+end
+
+function xban.serialize(t)
+	return "return {\n"..my_serialize_2(t, 1).."\n}"
+end
diff --git a/shutil.lua b/shutil.lua
new file mode 100644
index 0000000..e8ca269
--- /dev/null
+++ b/shutil.lua
@@ -0,0 +1,42 @@
+
+shutil = { }
+
+function shutil.copy_file(src, dst)
+	local e, sf, df, cont, ok
+	sf, e = io.open(src, "rb")
+	if not sf then
+		return nil, "Error opening input: "..(e or "")
+	end
+	df, e = io.open(dst, "wb")
+	if not df then
+		sf:close()
+		return nil, "Error opening output: "..(e or "")
+	end
+	cont, e = sf:read("*a")
+	if not cont then
+		sf:close()
+		df:close()
+		return nil, "Error reading input: "..(e or "")
+	end
+	ok, e = df:write(cont)
+	if not ok then
+		sf:close()
+		df:close()
+		return nil, "Error writing output: "..(e or "")
+	end
+	sf:close()
+	df:close()
+	return true
+end
+
+function shutil.move_file(src, dst)
+	local ok, e = shutil.copy_file(src, dst)
+	if not ok then
+		return nil, "Copy failed: "..(e or "")
+	end
+	ok, e = os.remove(src)
+	if not ok then
+		return nil, "Remove failed: "..(e or "")
+	end
+	return true
+end