Add a license file (#27)

This should prevent bans database from resetting with a "function has more than 65536 constants" error. Older databases should still be loaded correctly.

Also makes use of minetest.safe_file_write to avoid data corruption.

.luacheckrc

@@ -0,0 +1,7 @@
+
+unused_args = false
+allow_defined_top = true
+
+read_globals = {
+	"minetest",
+}

LICENSE

@@ -0,0 +1,24 @@
+BSD 2-Clause License
+
+Copyright (c) 2014-2023, Diego Martínez
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -0,0 +1,112 @@
+
+# Extended Ban Mod for Minetest
+
+This mod attempts to be an improvement to Minetest's ban system.
+
+* It supports normal bans and temporary bans (from 60 seconds up to the end of
+  time, with 1 second granularity).
+* Records and joins all accounts using the same IP address and several IP
+  addresses using the same name into a single record, and can ban/unban them as
+  a single user.
+* Can ban offline players if you know their IP or username.
+* Holds a record of bans for each user, so moderators and administrators can
+  consult it to know if a player is a repeat offender.
+* Does not modify the default ban database in any way (`ipban.txt').
+* Has an API to ban and check the ban database to allows other mods to manage
+  users (for example, anticheat mods).
+
+## Chat commands
+
+The mod provides the following chat commands. All commands require the `ban`
+privilege.
+
+### `xban`
+
+Bans a player permanently.
+
+**Usage:** `/xban <player_or_ip> <reason>`
+
+**Example:** `/xban 127.0.0.1 Some reason.`
+
+### `xtempban`
+
+Bans a player temporarily.
+
+**Usage:** `/xtempban <player_or_ip> <time> <reason>`
+
+The `time` parameter is a string in the format `<count><unit>` where `<unit>`
+is one of `s` for seconds, `m` for minutes, `h` for hours, `D` for days, `W`
+for weeks, `M` for months, or `Y` for years. If the unit is omitted, it is
+assumed to mean seconds. For example, `42s` means 42 seconds, `1337m` 1337
+minutes, and so on. You can chain more than one such group and they will add
+up. For example, `1Y3M3D7h` will ban for 1 year, 3 months, 3 days and 7 hours.
+
+**Example:** `/xtempban Joe 3600 Some reason.`
+
+### `xunban`
+
+Unbans a player.
+
+**Usage:** `/xunban <player_or_ip>`
+
+**Example:** `/xunban Joe`
+
+### `xban_record`
+
+Shows the ban record on chat.
+
+**Usage:** `/xban_record <player_or_ip>`
+
+This prints one ban entry per line, with the time the ban came into effect,
+the expiration time (if applicable), the reason, and the source of the ban.
+The record is printed to chat with one entry per line.
+
+**Example:** `/xban_record Joe`
+
+### `xban_wl`
+
+Manages the whitelist.
+
+**Usage:** `/xban_wl (add|del|get) <player_or_ip>`
+
+Whitelisted players are allowed on the server even if it's otherwise marked
+as banned. This is useful to only allow certain users from shared computers,
+for example.
+
+The `add` subcommand adds the player to the whitelist. The `del` subcommand
+removes the player from the whitelist. The `get` subcommand checks if the
+player is in the whitelist, and prints the status to chat.
+
+**Example:** `/xban_record add Jane`
+
+### `xban_gui`
+
+Shows a form to consult the database interactively.
+
+**Usage:** `/xban_gui`
+
+## Administrator commands
+
+The following commands require the `server` privilege, so they are only
+available to server administrators.
+
+### `xban_dbi`
+
+Imports ban entries from other database formats.
+
+**Usage:** `/xban_dbi <importer>`
+
+The `importer` argument specifies from which database to import. These are
+the supported import plugins at the time of writing:
+
+* `minetest`: Import entries from Minetest's ban list (`ipban.txt`).
+* `v1`: Old format used by xban (`players.iplist`).
+* `v2`: Old format used by xban (`players.iplist.v2`).
+
+**Example:** `/xban_dbi minetest`
+
+### `xban_cleanup`
+
+Removes all non-banned entries from the xban db.
+
+**Usage:** `/xban_cleanup`

dbimport.lua

@@ -11,13 +11,13 @@ minetest.register_chatcommand("xban_dbi", {
 	privs = { server=true },
 	func = function(name, params)
 		if params == "--list" then
-			local names = { }
+			local importers = { }
-			for name in pairs(xban.importers) do
+			for importer in pairs(xban.importers) do
-				table.insert(names, name)
+				table.insert(importers, importer)
 			end
 			minetest.chat_send_player(name,
 			  ("[xban] Known importers: %s"):format(
-			  table.concat(names, ", ")))
+			  table.concat(importers, ", ")))
 			return
 		elseif not xban.importers[params] then
 			minetest.chat_send_player(name,

gui.lua

@@ -9,9 +9,7 @@ local ESC = minetest.formspec_escape
 local function make_list(filter)
 	filter = filter or ""
 	local list, n, dropped = { }, 0, false
-	local enumerate, e1, e2, e3 = minetest.get_auth_handler().enumerate_auths
+	for k in minetest.get_auth_handler().iterate() do
-	if enumerate then e1 = enumerate() else e1, e2, e3 = pairs(minetest.auth_table) end
-	for k in e1, e2, e3 do
 		if strfind(k, filter, 1, true) then
 			if n >= MAXLISTSIZE then
 				dropped = true
@@ -63,7 +61,8 @@ local function make_fs(name)
 		"size[16,12]",
 		"label[0,-.1;Filter]",
 		"field[1.5,0;12.8,1;filter;;"..ESC(filter).."]",
-		"button[14,-.3;2,1;search;Search]",
+		"field_close_on_enter[filter;false]",
+		"button[14,-.3;2,1;search_submit;Search]",
 	}
 	local fsn = #fs
 	fsn=fsn+1 fs[fsn] = format("textlist[0,.8;4,9.3;player;%s;%d;0]",
@@ -102,6 +101,11 @@ end
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 	if formname ~= FORMNAME then return end
 	local name = player:get_player_name()
+	if not minetest.check_player_privs(name, { ban=true }) then
+		minetest.log("warning",
+				"[xban2] Received fields from unauthorized user: "..name)
+		return
+	end
 	local state = get_state(name)
 	if fields.player then
 		local t = minetest.explode_textlist_event(fields.player)
@@ -119,7 +123,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		end
 		return
 	end
-	if fields.search then
+	if fields.search_submit or fields.filter then
 		local filter = fields.filter or ""
 		state.filter = filter
 		state.list = make_list(filter)
@@ -130,6 +134,7 @@ end)
 minetest.register_chatcommand("xban_gui", {
 	description = "Show XBan GUI",
 	params = "",
+	privs = { ban=true, },
 	func = function(name, params)
 		minetest.show_formspec(name, FORMNAME, make_fs(name))
 	end,

importers/v2.lua

@@ -8,19 +8,19 @@ function xban.importers.v2()
 		local text = f:read("*a")
 		f:close()
 		local db = minetest.deserialize(text)
-		for _, e in ipairs(db) do
+		for _, ent in ipairs(db) do
-			for name in pairs(e.names) do
+			for name in pairs(ent.names) do
 				local entry = xban.find_entry(name, true)
 				if entry.source ~= "xban:importer_v2" then
 					for nm in pairs(e.names) do
 						entry.names[nm] = true
 					end
-					if e.banned then
+					if ent.banned then
 						entry.banned = true
 						entry.reason = e.banned
 						entry.source = "xban:importer_v2"
-						entry.time = e.time
+						entry.time = ent.time
-						entry.expires = e.expires
+						entry.expires = ent.expires
 						table.insert(entry.record, {
 							source = entry.source,
 							reason = entry.reason,

init.lua

@@ -9,9 +9,9 @@ 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 DB_FILENAME = minetest.settings:get("xban.db_filename")
 local SAVE_INTERVAL = tonumber(
-  minetest.setting_get("xban.db_save_interval")) or DEF_SAVE_INTERVAL
+  minetest.settings:get("xban.db_save_interval")) or DEF_SAVE_INTERVAL
 
 if (not DB_FILENAME) or (DB_FILENAME == "") then
 	DB_FILENAME = DEF_DB_FILENAME
@@ -24,7 +24,6 @@ local function make_logger(level)
 end
 
 local ACTION = make_logger("action")
-local INFO = make_logger("info")
 local WARNING = make_logger("warning")
 local ERROR = make_logger("error")
 
@@ -42,6 +41,14 @@ local function parse_time(t) --> secs
 	return secs
 end
 
+local function concat_keys(t, sep)
+	local keys = {}
+	for k, _ in pairs(t) do
+		keys[#keys + 1] = k
+	end
+	return table.concat(keys, sep)
+end
+
 function xban.find_entry(player, create) --> entry, index
 	for index, e in ipairs(db) do
 		for name in pairs(e.names) do
@@ -72,7 +79,13 @@ function xban.get_info(player) --> ip_name_list, banned, last_record
 end
 
 function xban.ban_player(player, source, expires, reason) --> bool, err
+	if xban.get_whitelist(player) then
+		return nil, "Player is whitelisted; remove from whitelist first"
+	end
 	local e = xban.find_entry(player, true)
+	if e.banned then
+		return nil, "Already banned"
+	end
 	local rec = {
 		source = source,
 		time = os.time(),
@@ -107,7 +120,7 @@ function xban.ban_player(player, source, expires, reason) --> bool, err
 	end
 	ACTION("%s bans %s until %s for reason: %s", source, player,
 	  date, reason)
-	ACTION("Banned Names/IPs: %s", table.concat(e.names, ", "))
+	ACTION("Banned Names/IPs: %s", concat_keys(e.names, ", "))
 	return true
 end
 
@@ -127,7 +140,29 @@ function xban.unban_player(player, source) --> bool, err
 	e.expires = nil
 	e.time = nil
 	ACTION("%s unbans %s", source, player)
-	ACTION("Unbanned Names/IPs: %s", table.concat(e.names, ", "))
+	ACTION("Unbanned Names/IPs: %s", concat_keys(e.names, ", "))
+	return true
+end
+
+function xban.get_whitelist(name_or_ip)
+	return db.whitelist and db.whitelist[name_or_ip]
+end
+
+function xban.remove_whitelist(name_or_ip)
+	if db.whitelist then
+		db.whitelist[name_or_ip] = nil
+	end
+end
+
+function xban.add_whitelist(name_or_ip, source)
+	local wl = db.whitelist
+	if not wl then
+		wl = { }
+		db.whitelist = wl
+	end
+	wl[name_or_ip] = {
+		source=source,
+	}
 	return true
 end
 
@@ -158,6 +193,8 @@ function xban.get_record(player)
 end
 
 minetest.register_on_prejoinplayer(function(name, ip)
+	local wl = db.whitelist or { }
+	if wl[name] or wl[ip] then return end
 	local e = xban.find_entry(name) or xban.find_entry(ip)
 	if not e then return end
 	if e.banned then
@@ -195,8 +232,8 @@ minetest.register_chatcommand("xban", {
 		if not (plname and reason) then
 			return false, "Usage: /xban <player> <reason>"
 		end
-		xban.ban_player(plname, name, nil, reason)
+		local ok, e = xban.ban_player(plname, name, nil, reason)
-		return true, ("Banned %s."):format(plname)
+		return ok, ok and ("Banned %s."):format(plname) or e
 	end,
 })
 
@@ -214,8 +251,9 @@ minetest.register_chatcommand("xtempban", {
 			return false, "You must ban for at least 60 seconds."
 		end
 		local expires = os.time() + time
-		xban.ban_player(plname, name, expires, reason)
+		local ok, e = xban.ban_player(plname, name, expires, reason)
-		return true, ("Banned %s until %s."):format(plname, os.date("%c", expires))
+		return ok, (ok and ("Banned %s until %s."):format(
+				plname, os.date("%c", expires)) or e)
 	end,
 })
 
@@ -260,6 +298,32 @@ minetest.register_chatcommand("xban_record", {
 	end,
 })
 
+minetest.register_chatcommand("xban_wl", {
+	description = "Manages the whitelist",
+	params = "(add|del|get) <name_or_ip>",
+	privs = { ban=true },
+	func = function(name, params)
+		local cmd, plname = params:match("%s*(%S+)%s*(%S+)")
+		if cmd == "add" then
+			xban.add_whitelist(plname, name)
+			ACTION("%s adds %s to whitelist", name, plname)
+			return true, "Added to whitelist: "..plname
+		elseif cmd == "del" then
+			xban.remove_whitelist(plname)
+			ACTION("%s removes %s to whitelist", name, plname)
+			return true, "Removed from whitelist: "..plname
+		elseif cmd == "get" then
+			local e = xban.get_whitelist(plname)
+			if e then
+				return true, "Source: "..(e.source or "Unknown")
+			else
+				return true, "No whitelist for: "..plname
+			end
+		end
+	end,
+})
+
+
 local function check_temp_bans()
 	minetest.after(60, check_temp_bans)
 	local to_rm = { }
@@ -280,18 +344,12 @@ end
 
 local function save_db()
 	minetest.after(SAVE_INTERVAL, save_db)
-	local f, e = io.open(DB_FILENAME, "wt")
 	db.timestamp = os.time()
-	if f then
+	local contents = assert(xban.serialize_db(db))
-		local ok, err = f:write(xban.serialize(db))
+	local ok = minetest.safe_file_write(DB_FILENAME, contents)
 	if not ok then
-			WARNING("Unable to save database: %s", err)
+		ERROR("Unable to save database")
 	end
-	else
-		WARNING("Unable to save database: %s", e)
-	end
-	if f then f:close() end
-	return
 end
 
 local function load_db()
@@ -305,10 +363,10 @@ local function load_db()
 		WARNING("Unable to load database: %s", "Read failed")
 		return
 	end
-	local t = minetest.deserialize(cont)
+	local t, e2 = xban.deserialize_db(cont)
 	if not t then
 		WARNING("Unable to load database: %s",
-		  "Deserialization failed")
+		  "Deserialization failed: "..(e2 or "unknown error"))
 		return
 	end
 	db = t
@@ -320,6 +378,30 @@ local function load_db()
 	end
 end
 
+minetest.register_chatcommand("xban_cleanup", {
+	description = "Removes all non-banned entries from the xban db",
+	privs = { server=true },
+	func = function(name, params)
+		local old_count = #db
+
+		local i = 1
+		while i <= #db do
+			if not db[i].banned then
+				-- not banned, remove from db
+				table.remove(db, i)
+			else
+				-- banned, hold entry back
+				i = i + 1
+			end
+		end
+
+		-- save immediately
+		save_db()
+
+		return true, "Removed " .. (old_count - #db) .. " entries, new db entry-count: " .. #db
+	end,
+})
+
 minetest.register_on_shutdown(save_db)
 minetest.after(SAVE_INTERVAL, save_db)
 load_db()

mod.conf

@@ -0,0 +1 @@
+name = xban2

serialize.lua

@@ -27,5 +27,44 @@ local function my_serialize_2(t, level)
 end
 
 function xban.serialize(t)
+	minetest.log("warning", "[xban2] xban.serialize() is deprecated")
 	return "return {\n"..my_serialize_2(t, 1).."\n}"
 end
+
+-- JSON doesn't allow combined string+number keys, this function moves any
+-- number keys into an "entries" table
+function xban.serialize_db(t)
+	local res = {}
+	local entries = {}
+	for k, v in pairs(t) do
+		if type(k) == "number" then
+			entries[k] = v
+		else
+			res[k] = v
+		end
+	end
+	res.entries = entries
+	return minetest.write_json(res, true)
+end
+
+function xban.deserialize_db(s)
+	if s:sub(1, 1) ~= "{" then
+		-- Load legacy databases
+		return minetest.deserialize(s)
+	end
+
+	local res, err = minetest.parse_json(s)
+	if not res then
+		return nil, err
+	end
+
+	-- Remove all "null"s added by empty tables
+	for i, entry in ipairs(res.entries or {}) do
+		entry.names = entry.names or {}
+		entry.record = entry.record or {}
+		res[i] = entry
+	end
+	res.entries = nil
+
+	return res
+end