aboutsummaryrefslogtreecommitdiff
path: root/advtrains_luaautomation/environment.lua
blob: 476faaf2448f492726968621a906b6a8663a6206 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
-------------
-- LuaATC sandboxed environment
-- @module atlatc

-- function to cross out functions and userdata.
-- modified from dump()
function atlatc.remove_invalid_data(o, nested)
	if o==nil then return nil end
	local valid_dt={["nil"]=true, boolean=true, number=true, string=true}
	if type(o) ~= "table" then
		--check valid data type
		if not valid_dt[type(o)] then
			return nil
		end
		return o
	end
	-- Contains table -> true/nil of currently nested tables
	nested = nested or {}
	if nested[o] then
		return nil
	end
	nested[o] = true
	for k, v in pairs(o) do
		v = atlatc.remove_invalid_data(v, nested)
	end
	nested[o] = nil
	return o
end


local env_proto={
	load = function(self, envname, data)
		self.name=envname
		self.sdata=data.sdata and atlatc.remove_invalid_data(data.sdata) or {}
		self.fdata={}
		self.init_code=data.init_code or ""
		self.subscribers=data.subscribers or {}
	end,
	save = function(self)
		-- throw any function values out of the sdata table
		self.sdata = atlatc.remove_invalid_data(self.sdata)
		return {sdata = self.sdata, init_code=self.init_code, subscribers=self.subscribers}
	end,
}

--Environment
--Code modified from mesecons_luacontroller (credit goes to Jeija and mesecons contributors)

local safe_globals = {
	"assert", "error", "ipairs", "next", "pairs", "select",
	"tonumber", "tostring", "type", "unpack", "_VERSION"
}

local function safe_date(f, t)
	if not f then
		-- fall back to old behavior
		return(os.date("*t",os.time()))
	else
		--pass parameters
		return os.date(f,t)
	end
end

-- string.rep(str, n) with a high value for n can be used to DoS
-- the server. Therefore, limit max. length of generated string.
local function safe_string_rep(str, n)
	if #str * n > 2000 then
		debug.sethook() -- Clear hook
		error("string.rep: string length overflow", 2)
	end

	return string.rep(str, n)
end

-- string.find with a pattern can be used to DoS the server.
-- Therefore, limit string.find to patternless matching.
-- Note: Disabled security since there are enough security leaks and this would be unneccessary anyway to DoS the server
local function safe_string_find(...)
	--if (select(4, ...)) ~= true then
	--	debug.sethook() -- Clear hook
	--	error("string.find: 'plain' (fourth parameter) must always be true for security reasons.")
	--end

	return string.find(...)
end

local mp=minetest.get_modpath("advtrains_luaautomation")

local static_env = {
	--core LUA functions
	string = {
		byte = string.byte,
		char = string.char,
		format = string.format,
		len = string.len,
		lower = string.lower,
		upper = string.upper,
		rep = safe_string_rep,
		reverse = string.reverse,
		sub = string.sub,
		find = safe_string_find,
	},
	math = {
		abs = math.abs,
		acos = math.acos,
		asin = math.asin,
		atan = math.atan,
		atan2 = math.atan2,
		ceil = math.ceil,
		cos = math.cos,
		cosh = math.cosh,
		deg = math.deg,
		exp = math.exp,
		floor = math.floor,
		fmod = math.fmod,
		frexp = math.frexp,
		huge = math.huge,
		ldexp = math.ldexp,
		log = math.log,
		log10 = math.log10,
		max = math.max,
		min = math.min,
		modf = math.modf,
		pi = math.pi,
		pow = math.pow,
		rad = math.rad,
		random = math.random,
		sin = math.sin,
		sinh = math.sinh,
		sqrt = math.sqrt,
		tan = math.tan,
		tanh = math.tanh,
	},
	table = {
		concat = table.concat,
		insert = table.insert,
		maxn = table.maxn,
		remove = table.remove,
		sort = table.sort,
	},
	os = {
		clock = os.clock,
		difftime = os.difftime,
		time = os.time,
		date = safe_date,
	},
	POS = function(x,y,z) return {x=x, y=y, z=z} end,
	getstate = advtrains.getstate,
	setstate = advtrains.setstate,
	is_passive = advtrains.is_passive,
	--interrupts are handled per node, position unknown. (same goes for digilines)
	--however external interrupts can be set here.
	interrupt_pos = function(parpos, imesg)
		local pos=atlatc.pcnaming.resolve_pos(parpos, "interrupt_pos")
		atlatc.interrupt.add(0, pos, {type="ext_int", ext_int=true, message=imesg})
	end,
	-- sends an atc command to train regardless of where it is in the world
	atc_send_to_train = function(train_id, command)
		assertt(command, "string")
		local train = advtrains.trains[train_id]
		if train then
			advtrains.atc.train_set_command(train, command, true)
			return true
		else
			return false
		end
	end,
}

-- If interlocking is present, enable route setting functions
if advtrains.interlocking then
	local function gen_checks(signal, route_name, noroutesearch)
		assertt(route_name, "string")
		local pos = atlatc.pcnaming.resolve_pos(signal)
		local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
		if not sigd then
			error("There's no signal at "..minetest.pos_to_string(pos))
		end
		local tcbs = advtrains.interlocking.db.get_tcbs(sigd)
		if not tcbs then
			error("Inconsistent configuration, no tcbs for signal at "..minetest.pos_to_string(pos))
		end
		
		local routeid, route
		if not noroutesearch then
			for routeidt, routet in ipairs(tcbs.routes) do
				if routet.name == route_name then
					routeid = routeidt
					route = routet
					break
				end
			end
			if not route then
				error("No route called "..route_name.." at "..minetest.pos_to_string(pos))
			end
		end
		return pos, sigd, tcbs, routeid, route
	end


	static_env.can_set_route = function(signal, route_name)
		local pos, sigd, tcbs, routeid, route = gen_checks(signal, route_name)
		-- if route is already set on signal, return whether it's committed
		if tcbs.routeset == routeid then
			return tcbs.route_committed
		end
		-- actually try setting route (parameter 'true' designates try-run
		local ok = advtrains.interlocking.route.set_route(sigd, route, true)
		return ok
	end
	static_env.set_route = function(signal, route_name)
		local pos, sigd, tcbs, routeid, route = gen_checks(signal, route_name)
		return advtrains.interlocking.route.update_route(sigd, tcbs, routeid)
	end
	static_env.cancel_route = function(signal)
		local pos, sigd, tcbs, routeid, route = gen_checks(signal, "", true)
		return advtrains.interlocking.route.update_route(sigd, tcbs, nil, true)
	end
	static_env.get_aspect = function(signal)
		local pos = atlatc.pcnaming.resolve_pos(signal)
		return advtrains.interlocking.signal_get_aspect(pos)
	end
	static_env.set_aspect = function(signal, asp)
		local pos = atlatc.pcnaming.resolve_pos(signal)
		return advtrains.interlocking.signal_set_aspect(pos)
	end
	
	--section_occupancy()
	static_env.section_occupancy = function(ts_id)
		if not ts_id then return nil end
		ts_id = tostring(ts_id)
		local response = advtrains.interlocking.db.get_ts(ts_id)
		if response == nil then
			return false
		else
			return response.trains
		end
	end
end

-- Lines-specific:
if advtrains.lines then
	local atlrwt = advtrains.lines.rwt
	static_env.rwt = {
		now = atlrwt.now,
		new = atlrwt.new,
		copy = atlrwt.copy,
		to_table = atlrwt.to_table,
		to_secs = atlrwt.to_secs,
		to_string = atlrwt.to_string,
		add = atlrwt.add,
		diff = atlrwt.diff,
		sub = atlrwt.sub,
		adj_diff = atlrwt.adj_diff,
		adjust_cycle = atlrwt.adjust_cycle,
		adjust = atlrwt.adjust,
		to_string = atlrwt.to_string,
		get_time_until = atlrwt.get_time_until,
		next_rpt = atlrwt.next_rpt,
		last_rpt = atlrwt.last_rpt,
		time_from_last_rpt = atlrwt.time_from_last_rpt,
		time_to_next_rpt = atlrwt.time_to_next_rpt,
	}
end

for _, name in pairs(safe_globals) do
	static_env[name] = _G[name]
end

--The environment all code calls get is a table that has set static_env as metatable.
--In general, every variable is local to a single code chunk, but kept persistent over code re-runs. Data is also saved, but functions and userdata and circular references are removed
--Init code and step code's environments are not saved
-- S - Table that can contain any save data global to the environment. Will be saved statically. Can't contain functions or userdata or circular references.
-- F - Table global to the environment, can contain volatile data that is deleted when server quits.
--     The init code should populate this table with functions and other definitions.

local proxy_env={}
--proxy_env gets a new metatable in every run, but is the shared environment of all functions ever defined.

-- returns: true, fenv if successful; nil, error if error 
function env_proto:execute_code(localenv, code, evtdata, customfct)
	-- create us a print function specific for this environment
	if not self.safe_print_func then
		local myenv = self
		self.safe_print_func = function(...)
			myenv:log("info", ...)
		end
	end
	
	local metatbl ={
		__index = function(t, i)
			if i=="S" then
				return self.sdata
			elseif i=="F" then
				return self.fdata
			elseif i=="event" then
				return evtdata
			elseif customfct and customfct[i] then
				return customfct[i]
			elseif localenv and localenv[i] then
				return localenv[i]
			elseif i=="print" then
				return self.safe_print_func
			end
			return static_env[i]
		end,
		__newindex = function(t, i, v)
			if i=="S" or i=="F" or i=="event" or (customfct and customfct[i]) or static_env[i] then
				debug.sethook()
				error("Trying to overwrite environment contents")
			end
			localenv[i]=v
		end,
	}
	setmetatable(proxy_env, metatbl)
	local fun, err=loadstring(code)
	if not fun then
		return false, err
	end
	
	setfenv(fun, proxy_env)
	local succ, data = pcall(fun)
	if succ then
		data=localenv
	end
	return succ, data
end

function env_proto:run_initcode()
	if self.init_code and self.init_code~="" then
		local old_fdata=self.fdata
		self.fdata = {}
		--atprint("[atlatc]Running initialization code for environment '"..self.name.."'")
		local succ, err = self:execute_code({}, self.init_code, {type="init", init=true})
		if not succ then
			self:log("error", "Executing InitCode for '"..self.name.."' failed:"..err)
			self.init_err=err
			if old_fdata then
				self.fdata=old_fdata
				self:log("warning", "The 'F' table has been restored to the previous state.")
			end
		end
	end
end

-- log to environment subscribers. severity can be "error", "warning" or "info" (used by internal print)
function env_proto:log(severity, ...)
	local text=advtrains.print_concat_table({"[atlatc "..self.name.." "..severity.."]", ...})
	minetest.log("action", text)
	for _, pname in ipairs(self.subscribers) do
		minetest.chat_send_player(pname, text)
	end
end

-- env.subscribers table may be directly altered by callers.


-- class interface

function atlatc.env_new(name)
	local newenv={
		name=name,
		init_code="",
		sdata={},
		subscribers={},
	}
	setmetatable(newenv, {__index=env_proto})
	return newenv
end
function atlatc.env_load(name, data)
	local newenv={}
	setmetatable(newenv, {__index=env_proto})
	newenv:load(name, data)
	return newenv
end

function atlatc.run_initcode()
	for envname, env in pairs(atlatc.envs) do
		env:run_initcode()
	end
end