cc-mek-scada/supervisor/session/pocket.lua
2024-06-29 02:27:55 +00:00

282 lines
9.7 KiB
Lua

local comms = require("scada-common.comms")
local log = require("scada-common.log")
local mqueue = require("scada-common.mqueue")
local util = require("scada-common.util")
local databus = require("supervisor.databus")
local pocket = {}
local PROTOCOL = comms.PROTOCOL
local MGMT_TYPE = comms.MGMT_TYPE
-- retry time constants in ms
-- local INITIAL_WAIT = 1500
-- local RETRY_PERIOD = 1000
local POCKET_S_CMDS = {
}
local POCKET_S_DATA = {
}
pocket.POCKET_S_CMDS = POCKET_S_CMDS
pocket.POCKET_S_DATA = POCKET_S_DATA
local PERIODICS = {
KEEP_ALIVE = 2000
}
-- pocket diagnostics session
---@nodiscard
---@param id integer session ID
---@param s_addr integer device source address
---@param i_seq_num integer initial sequence number
---@param in_queue mqueue in message queue
---@param out_queue mqueue out message queue
---@param timeout number communications timeout
---@param facility facility facility data table
---@param fp_ok boolean if the front panel UI is running
function pocket.new_session(id, s_addr, i_seq_num, in_queue, out_queue, timeout, facility, fp_ok)
-- print a log message to the terminal as long as the UI isn't running
local function println(message) if not fp_ok then util.println_ts(message) end end
local log_header = "pdg_session(" .. id .. "): "
local self = {
-- connection properties
seq_num = i_seq_num,
connected = true,
conn_watchdog = util.new_watchdog(timeout),
last_rtt = 0,
-- periodic messages
periodics = {
last_update = 0,
keep_alive = 0
},
-- when to next retry one of these requests
retry_times = {
},
-- command acknowledgements
acks = {
},
-- session database
---@class pdg_db
sDB = {
}
}
---@class pdg_session
local public = {}
-- mark this diagnostics session as closed, stop watchdog
local function _close()
self.conn_watchdog.cancel()
self.connected = false
databus.tx_pdg_disconnected(id)
end
-- send a SCADA management packet
---@param msg_type MGMT_TYPE
---@param msg table
local function _send_mgmt(msg_type, msg)
local s_pkt = comms.scada_packet()
local m_pkt = comms.mgmt_packet()
m_pkt.make(msg_type, msg)
s_pkt.make(s_addr, self.seq_num, PROTOCOL.SCADA_MGMT, m_pkt.raw_sendable())
out_queue.push_packet(s_pkt)
self.seq_num = self.seq_num + 1
end
-- handle a packet
---@param pkt mgmt_frame
local function _handle_packet(pkt)
-- check sequence number
if self.seq_num ~= pkt.scada_frame.seq_num() then
log.warning(log_header .. "sequence out-of-order: last = " .. self.seq_num .. ", new = " .. pkt.scada_frame.seq_num())
return
else
self.seq_num = pkt.scada_frame.seq_num() + 1
end
-- feed watchdog
self.conn_watchdog.feed()
-- process packet
if pkt.scada_frame.protocol() == PROTOCOL.SCADA_MGMT then
---@cast pkt mgmt_frame
if pkt.type == MGMT_TYPE.KEEP_ALIVE then
-- keep alive reply
if pkt.length == 2 then
local srv_start = pkt.data[1]
-- local pdg_send = pkt.data[2]
local srv_now = util.time()
self.last_rtt = srv_now - srv_start
if self.last_rtt > 750 then
log.warning(log_header .. "PDG KEEP_ALIVE round trip time > 750ms (" .. self.last_rtt .. "ms)")
end
-- log.debug(log_header .. "PDG RTT = " .. self.last_rtt .. "ms")
-- log.debug(log_header .. "PDG TT = " .. (srv_now - pdg_send) .. "ms")
databus.tx_pdg_rtt(id, self.last_rtt)
else
log.debug(log_header .. "SCADA keep alive packet length mismatch")
end
elseif pkt.type == MGMT_TYPE.CLOSE then
-- close the session
_close()
elseif pkt.type == MGMT_TYPE.DIAG_TONE_GET then
-- get the state of alarm tones
_send_mgmt(MGMT_TYPE.DIAG_TONE_GET, facility.get_alarm_tones())
elseif pkt.type == MGMT_TYPE.DIAG_TONE_SET then
local valid = false
-- attempt to set a tone state
if pkt.scada_frame.is_authenticated() then
if pkt.length == 2 then
if type(pkt.data[1]) == "number" and type(pkt.data[2]) == "boolean" then
valid = true
-- try to set tone states, then send back if testing is allowed
local allow_testing, test_tone_states = facility.diag_set_test_tone(pkt.data[1], pkt.data[2])
_send_mgmt(MGMT_TYPE.DIAG_TONE_SET, { allow_testing, test_tone_states })
else
log.debug(log_header .. "SCADA diag tone set packet data type mismatch")
end
else
log.debug(log_header .. "SCADA diag tone set packet length mismatch")
end
else
log.debug(log_header .. "DIAG_TONE_SET is blocked without HMAC for security")
end
if not valid then _send_mgmt(MGMT_TYPE.DIAG_TONE_SET, { false }) end
elseif pkt.type == MGMT_TYPE.DIAG_ALARM_SET then
local valid = false
-- attempt to set an alarm state
if pkt.scada_frame.is_authenticated() then
if pkt.length == 2 then
if type(pkt.data[1]) == "number" and type(pkt.data[2]) == "boolean" then
valid = true
-- try to set alarm states, then send back if testing is allowed
local allow_testing, test_alarm_states = facility.diag_set_test_alarm(pkt.data[1], pkt.data[2])
_send_mgmt(MGMT_TYPE.DIAG_ALARM_SET, { allow_testing, test_alarm_states })
else
log.debug(log_header .. "SCADA diag alarm set packet data type mismatch")
end
else
log.debug(log_header .. "SCADA diag alarm set packet length mismatch")
end
else
log.debug(log_header .. "DIAG_ALARM_SET is blocked without HMAC for security")
end
if not valid then _send_mgmt(MGMT_TYPE.DIAG_ALARM_SET, { false }) end
else
log.debug(log_header .. "handler received unsupported SCADA_MGMT packet type " .. pkt.type)
end
end
end
-- PUBLIC FUNCTIONS --
-- get the session ID
---@nodiscard
function public.get_id() return id end
-- get the session database
---@nodiscard
function public.get_db() return self.sDB end
-- check if a timer matches this session's watchdog
---@nodiscard
function public.check_wd(timer)
return self.conn_watchdog.is_timer(timer) and self.connected
end
-- close the connection
function public.close()
_close()
_send_mgmt(MGMT_TYPE.CLOSE, {})
println("connection to pocket diag session " .. id .. " closed by server")
log.info(log_header .. "session closed by server")
end
-- iterate the session
---@nodiscard
---@return boolean connected
function public.iterate()
if self.connected then
------------------
-- handle queue --
------------------
local handle_start = util.time()
while in_queue.ready() and self.connected do
-- get a new message to process
local message = in_queue.pop()
if message ~= nil then
if message.qtype == mqueue.TYPE.PACKET then
-- handle a packet
_handle_packet(message.message)
elseif message.qtype == mqueue.TYPE.COMMAND then
-- handle instruction
elseif message.qtype == mqueue.TYPE.DATA then
-- instruction with body
end
end
-- max 100ms spent processing queue
if util.time() - handle_start > 100 then
log.warning(log_header .. "exceeded 100ms queue process limit")
break
end
end
-- exit if connection was closed
if not self.connected then
println("connection to pocket diag session " .. id .. " closed by remote host")
log.info(log_header .. "session closed by remote host")
return self.connected
end
----------------------
-- update periodics --
----------------------
local elapsed = util.time() - self.periodics.last_update
local periodics = self.periodics
-- keep alive
periodics.keep_alive = periodics.keep_alive + elapsed
if periodics.keep_alive >= PERIODICS.KEEP_ALIVE then
_send_mgmt(MGMT_TYPE.KEEP_ALIVE, { util.time() })
periodics.keep_alive = 0
end
self.periodics.last_update = util.time()
---------------------
-- attempt retries --
---------------------
-- local rtimes = self.retry_times
end
return self.connected
end
return public
end
return pocket