cc-mek-scada/rtu/rtu.lua

571 lines
20 KiB
Lua

local audio = require("scada-common.audio")
local comms = require("scada-common.comms")
local ppm = require("scada-common.ppm")
local log = require("scada-common.log")
local types = require("scada-common.types")
local util = require("scada-common.util")
local databus = require("rtu.databus")
local modbus = require("rtu.modbus")
local rtu = {}
local PROTOCOL = comms.PROTOCOL
local DEVICE_TYPE = comms.DEVICE_TYPE
local ESTABLISH_ACK = comms.ESTABLISH_ACK
local MGMT_TYPE = comms.MGMT_TYPE
local RTU_UNIT_TYPE = types.RTU_UNIT_TYPE
---@type rtu_config
local config = {}
rtu.config = config
-- load the RTU configuration
function rtu.load_config()
if not settings.load("/rtu.settings") then return false end
config.Peripherals = settings.get("Peripherals")
config.Redstone = settings.get("Redstone")
config.SpeakerVolume = settings.get("SpeakerVolume")
config.SVR_Channel = settings.get("SVR_Channel")
config.RTU_Channel = settings.get("RTU_Channel")
config.ConnTimeout = settings.get("ConnTimeout")
config.TrustedRange = settings.get("TrustedRange")
config.AuthKey = settings.get("AuthKey")
config.LogMode = settings.get("LogMode")
config.LogPath = settings.get("LogPath")
config.LogDebug = settings.get("LogDebug")
local cfv = util.new_validator()
cfv.assert_type_num(config.SpeakerVolume)
cfv.assert_channel(config.SVR_Channel)
cfv.assert_channel(config.RTU_Channel)
cfv.assert_type_int(config.ConnTimeout)
cfv.assert_min(config.ConnTimeout, 2)
cfv.assert_type_num(config.TrustedRange)
cfv.assert_min(config.TrustedRange, 0)
cfv.assert_type_str(config.AuthKey)
if type(config.AuthKey) == "string" then
local len = string.len(config.AuthKey)
cfv.assert_eq(len == 0 or len >= 8, true)
end
cfv.assert_type_int(config.LogMode)
cfv.assert_type_str(config.LogPath)
cfv.assert_type_bool(config.LogDebug)
cfv.assert_type_table(config.Peripherals)
cfv.assert_type_table(config.Redstone)
return cfv.valid()
end
-- create a new RTU unit
---@nodiscard
function rtu.init_unit()
local self = {
discrete_inputs = {},
coils = {},
input_regs = {},
holding_regs = {},
io_count_cache = { 0, 0, 0, 0 }
}
local insert = table.insert
---@class rtu_device
local public = {}
---@class rtu
local protected = {}
-- refresh IO count
local function _count_io()
self.io_count_cache = { #self.discrete_inputs, #self.coils, #self.input_regs, #self.holding_regs }
end
-- return IO count
---@return integer discrete_inputs, integer coils, integer input_regs, integer holding_regs
function public.io_count()
return self.io_count_cache[1], self.io_count_cache[2], self.io_count_cache[3], self.io_count_cache[4]
end
-- discrete inputs: single bit read-only
-- connect discrete input
---@param f function
---@return integer count count of discrete inputs
function protected.connect_di(f)
insert(self.discrete_inputs, { read = f })
_count_io()
return #self.discrete_inputs
end
-- read discrete input
---@param di_addr integer
---@return any value, boolean access_fault
function public.read_di(di_addr)
ppm.clear_fault()
local value = self.discrete_inputs[di_addr].read()
return value, ppm.is_faulted()
end
-- coils: single bit read-write
-- connect coil
---@param f_read function
---@param f_write function
---@return integer count count of coils
function protected.connect_coil(f_read, f_write)
insert(self.coils, { read = f_read, write = f_write })
_count_io()
return #self.coils
end
-- read coil
---@param coil_addr integer
---@return any value, boolean access_fault
function public.read_coil(coil_addr)
ppm.clear_fault()
local value = self.coils[coil_addr].read()
return value, ppm.is_faulted()
end
-- write coil
---@param coil_addr integer
---@param value any
---@return boolean access_fault
function public.write_coil(coil_addr, value)
ppm.clear_fault()
self.coils[coil_addr].write(value)
return ppm.is_faulted()
end
-- input registers: multi-bit read-only
-- connect input register
---@param f function
---@return integer count count of input registers
function protected.connect_input_reg(f)
insert(self.input_regs, { read = f })
_count_io()
return #self.input_regs
end
-- read input register
---@param reg_addr integer
---@return any value, boolean access_fault
function public.read_input_reg(reg_addr)
ppm.clear_fault()
local value = self.input_regs[reg_addr].read()
return value, ppm.is_faulted()
end
-- holding registers: multi-bit read-write
-- connect holding register
---@param f_read function
---@param f_write function
---@return integer count count of holding registers
function protected.connect_holding_reg(f_read, f_write)
insert(self.holding_regs, { read = f_read, write = f_write })
_count_io()
return #self.holding_regs
end
-- read holding register
---@param reg_addr integer
---@return any value, boolean access_fault
function public.read_holding_reg(reg_addr)
ppm.clear_fault()
local value = self.holding_regs[reg_addr].read()
return value, ppm.is_faulted()
end
-- write holding register
---@param reg_addr integer
---@param value any
---@return boolean access_fault
function public.write_holding_reg(reg_addr, value)
ppm.clear_fault()
self.holding_regs[reg_addr].write(value)
return ppm.is_faulted()
end
-- public RTU device access
-- get the public interface to this RTU
function protected.interface() return public end
return protected
end
-- create an alarm speaker sounder
---@param speaker table device peripheral
function rtu.init_sounder(speaker)
---@class rtu_speaker_sounder
local spkr_ctl = {
speaker = speaker,
name = ppm.get_iface(speaker),
playing = false,
stream = audio.new_stream(),
play = function () end,
stop = function () end,
continue = function () end
}
-- continue audio stream if playing
function spkr_ctl.continue()
if spkr_ctl.playing then
if spkr_ctl.speaker ~= nil and spkr_ctl.stream.has_next_block() then
local success = spkr_ctl.speaker.playAudio(spkr_ctl.stream.get_next_block(), config.SpeakerVolume)
if not success then log.error(util.c("rtu_sounder(", spkr_ctl.name, "): error playing audio")) end
end
end
end
-- start audio stream playback
function spkr_ctl.play()
if not spkr_ctl.playing then
spkr_ctl.playing = true
return spkr_ctl.continue()
end
end
-- stop audio stream playback
function spkr_ctl.stop()
spkr_ctl.playing = false
spkr_ctl.speaker.stop()
spkr_ctl.stream.stop()
end
return spkr_ctl
end
-- RTU Communications
---@nodiscard
---@param version string RTU version
---@param nic nic network interface device
---@param conn_watchdog watchdog watchdog reference
function rtu.comms(version, nic, conn_watchdog)
local self = {
sv_addr = comms.BROADCAST,
seq_num = 0,
r_seq_num = nil,
txn_id = 0,
last_est_ack = ESTABLISH_ACK.ALLOW
}
local insert = table.insert
comms.set_trusted_range(config.TrustedRange)
-- PRIVATE FUNCTIONS --
-- configure modem channels
nic.closeAll()
nic.open(config.RTU_Channel)
-- send a scada management packet
---@param msg_type MGMT_TYPE
---@param msg table
local function _send(msg_type, msg)
local s_pkt = comms.scada_packet()
local m_pkt = comms.mgmt_packet()
m_pkt.make(msg_type, msg)
s_pkt.make(self.sv_addr, self.seq_num, PROTOCOL.SCADA_MGMT, m_pkt.raw_sendable())
nic.transmit(config.SVR_Channel, config.RTU_Channel, s_pkt)
self.seq_num = self.seq_num + 1
end
-- keep alive ack
---@param srv_time integer
local function _send_keep_alive_ack(srv_time)
_send(MGMT_TYPE.KEEP_ALIVE, { srv_time, util.time() })
end
-- generate device advertisement table
---@nodiscard
---@param units table
---@return table advertisement
local function _generate_advertisement(units)
local advertisement = {}
for i = 1, #units do
local unit = units[i] ---@type rtu_unit_registry_entry
if unit.type ~= nil then
local advert = { unit.type, unit.index, unit.reactor }
if unit.type == RTU_UNIT_TYPE.REDSTONE then
insert(advert, unit.device)
end
insert(advertisement, advert)
end
end
return advertisement
end
-- PUBLIC FUNCTIONS --
---@class rtu_comms
local public = {}
-- send a MODBUS TCP packet
---@param m_pkt modbus_packet
function public.send_modbus(m_pkt)
local s_pkt = comms.scada_packet()
s_pkt.make(self.sv_addr, self.seq_num, PROTOCOL.MODBUS_TCP, m_pkt.raw_sendable())
nic.transmit(config.SVR_Channel, config.RTU_Channel, s_pkt)
self.seq_num = self.seq_num + 1
end
-- unlink from the server
---@param rtu_state rtu_state
function public.unlink(rtu_state)
rtu_state.linked = false
self.sv_addr = comms.BROADCAST
self.r_seq_num = nil
databus.tx_link_state(types.PANEL_LINK_STATE.DISCONNECTED)
end
-- close the connection to the server
---@param rtu_state rtu_state
function public.close(rtu_state)
conn_watchdog.cancel()
public.unlink(rtu_state)
_send(MGMT_TYPE.CLOSE, {})
end
-- send establish request (includes advertisement)
---@param units table
function public.send_establish(units)
_send(MGMT_TYPE.ESTABLISH, { comms.version, version, DEVICE_TYPE.RTU, _generate_advertisement(units) })
end
-- send capability advertisement
---@param units table
function public.send_advertisement(units)
_send(MGMT_TYPE.RTU_ADVERT, _generate_advertisement(units))
end
-- notify that a peripheral was remounted
---@param unit_index integer RTU unit ID
function public.send_remounted(unit_index)
_send(MGMT_TYPE.RTU_DEV_REMOUNT, { unit_index })
end
-- parse a MODBUS/SCADA packet
---@nodiscard
---@param side string
---@param sender integer
---@param reply_to integer
---@param message any
---@param distance integer
---@return modbus_frame|mgmt_frame|nil packet
function public.parse_packet(side, sender, reply_to, message, distance)
local s_pkt = nic.receive(side, sender, reply_to, message, distance)
local pkt = nil
if s_pkt then
-- get as MODBUS TCP packet
if s_pkt.protocol() == PROTOCOL.MODBUS_TCP then
local m_pkt = comms.modbus_packet()
if m_pkt.decode(s_pkt) then
pkt = m_pkt.get()
end
-- get as SCADA management packet
elseif s_pkt.protocol() == PROTOCOL.SCADA_MGMT then
local mgmt_pkt = comms.mgmt_packet()
if mgmt_pkt.decode(s_pkt) then
pkt = mgmt_pkt.get()
end
else
log.debug("illegal packet type " .. s_pkt.protocol(), true)
end
end
return pkt
end
-- handle a MODBUS/SCADA packet
---@param packet modbus_frame|mgmt_frame
---@param units table RTU units
---@param rtu_state rtu_state
---@param sounders table speaker alarm sounders
function public.handle_packet(packet, units, rtu_state, sounders)
-- print a log message to the terminal as long as the UI isn't running
local function println_ts(message) if not rtu_state.fp_ok then util.println_ts(message) end end
local protocol = packet.scada_frame.protocol()
local l_chan = packet.scada_frame.local_channel()
local src_addr = packet.scada_frame.src_addr()
if l_chan == config.RTU_Channel then
-- check sequence number
if self.r_seq_num == nil then
self.r_seq_num = packet.scada_frame.seq_num()
elseif rtu_state.linked and ((self.r_seq_num + 1) ~= packet.scada_frame.seq_num()) then
log.warning("sequence out-of-order: last = " .. self.r_seq_num .. ", new = " .. packet.scada_frame.seq_num())
return
elseif rtu_state.linked and (src_addr ~= self.sv_addr) then
log.debug("received packet from unknown computer " .. src_addr .. " while linked (expected " .. self.sv_addr ..
"); channel in use by another system?")
return
else
self.r_seq_num = packet.scada_frame.seq_num()
end
-- feed watchdog on valid sequence number
conn_watchdog.feed()
-- handle packet
if protocol == PROTOCOL.MODBUS_TCP then
---@cast packet modbus_frame
if rtu_state.linked then
local return_code ---@type boolean
local reply ---@type modbus_packet
-- handle MODBUS instruction
if packet.unit_id <= #units then
local unit = units[packet.unit_id] ---@type rtu_unit_registry_entry
local unit_dbg_tag = " (unit " .. packet.unit_id .. ")"
if unit.name == "redstone_io" then
-- immediately execute redstone RTU requests
return_code, reply = unit.modbus_io.handle_packet(packet)
if not return_code then
log.warning("requested MODBUS operation failed" .. unit_dbg_tag)
end
else
-- check validity then pass off to unit comms thread
return_code, reply = unit.modbus_io.check_request(packet)
if return_code then
-- check if there are more than 3 active transactions
-- still queue the packet, but this may indicate a problem
if unit.pkt_queue.length() > 3 then
reply = modbus.reply__srv_device_busy(packet)
log.debug("queueing new request with " .. unit.pkt_queue.length() ..
" transactions already in the queue" .. unit_dbg_tag)
end
-- always queue the command even if busy
unit.pkt_queue.push_packet(packet)
else
log.warning("cannot perform requested MODBUS operation" .. unit_dbg_tag)
end
end
else
-- unit ID out of range?
reply = modbus.reply__gw_unavailable(packet)
log.debug("received MODBUS packet for non-existent unit")
end
public.send_modbus(reply)
else
log.debug("discarding MODBUS packet before linked")
end
elseif protocol == PROTOCOL.SCADA_MGMT then
---@cast packet mgmt_frame
-- SCADA management packet
if rtu_state.linked then
if packet.type == MGMT_TYPE.KEEP_ALIVE then
-- keep alive request received, echo back
if packet.length == 1 and type(packet.data[1]) == "number" then
local timestamp = packet.data[1]
local trip_time = util.time() - timestamp
if trip_time > 750 then
log.warning("RTU KEEP_ALIVE trip time > 750ms (" .. trip_time .. "ms)")
end
-- log.debug("RTU RTT = " .. trip_time .. "ms")
_send_keep_alive_ack(timestamp)
else
log.debug("SCADA_MGMT keep alive packet length/type mismatch")
end
elseif packet.type == MGMT_TYPE.CLOSE then
-- close connection
conn_watchdog.cancel()
public.unlink(rtu_state)
println_ts("server connection closed by remote host")
log.warning("server connection closed by remote host")
elseif packet.type == MGMT_TYPE.RTU_ADVERT then
-- request for capabilities again
public.send_advertisement(units)
elseif packet.type == MGMT_TYPE.RTU_TONE_ALARM then
-- alarm tone update from supervisor
if (packet.length == 1) and type(packet.data[1] == "table") and (#packet.data[1] == 8) then
local states = packet.data[1]
for i = 1, #sounders do
local s = sounders[i] ---@type rtu_speaker_sounder
-- set tone states
for id = 1, #states do s.stream.set_active(id, states[id] == true) end
end
end
else
-- not supported
log.debug("received unsupported SCADA_MGMT message type " .. packet.type)
end
elseif packet.type == MGMT_TYPE.ESTABLISH then
if packet.length == 1 then
local est_ack = packet.data[1]
if est_ack == ESTABLISH_ACK.ALLOW then
-- establish allowed
rtu_state.linked = true
self.sv_addr = packet.scada_frame.src_addr()
self.r_seq_num = nil
println_ts("supervisor connection established")
log.info("supervisor connection established")
else
-- establish denied
if est_ack ~= self.last_est_ack then
if est_ack == ESTABLISH_ACK.BAD_VERSION then
-- version mismatch
println_ts("supervisor comms version mismatch (try updating), retrying...")
log.warning("supervisor connection denied due to comms version mismatch, retrying")
else
println_ts("supervisor connection denied, retrying...")
log.warning("supervisor connection denied, retrying")
end
end
public.unlink(rtu_state)
end
self.last_est_ack = est_ack
-- report link state
databus.tx_link_state(est_ack + 1)
else
log.debug("SCADA_MGMT establish packet length mismatch")
end
else
log.debug("discarding non-link SCADA_MGMT packet before linked")
end
else
-- should be unreachable assuming packet is from parse_packet()
log.error("illegal packet type " .. protocol, true)
end
else
log.debug("received packet on unconfigured channel " .. l_chan, true)
end
end
return public
end
return rtu