cc-mek-scada/coordinator/session/pocket.lua
2024-04-14 16:16:18 -04:00

283 lines
8.6 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 iocontrol = require("coordinator.iocontrol")
local pocket = {}
local PROTOCOL = comms.PROTOCOL
local CRDN_TYPE = comms.CRDN_TYPE
local MGMT_TYPE = comms.MGMT_TYPE
-- retry time constants in ms
-- local INITIAL_WAIT = 1500
-- local RETRY_PERIOD = 1000
local API_S_CMDS = {
}
local API_S_DATA = {
}
pocket.API_S_CMDS = API_S_CMDS
pocket.API_S_DATA = API_S_DATA
local PERIODICS = {
KEEP_ALIVE = 2000
}
-- pocket API session
---@nodiscard
---@param id integer session ID
---@param s_addr integer device source address
---@param in_queue mqueue in message queue
---@param out_queue mqueue out message queue
---@param timeout number communications timeout
function pocket.new_session(id, s_addr, in_queue, out_queue, timeout)
local log_header = "pkt_session(" .. id .. "): "
local self = {
-- connection properties
seq_num = 0,
r_seq_num = nil,
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 api_db
sDB = {
}
}
---@class pkt_session
local public = {}
-- mark this pocket session as closed, stop watchdog
local function _close()
self.conn_watchdog.cancel()
self.connected = false
iocontrol.fp_pkt_disconnected(id)
end
-- send a CRDN packet
---@param msg_type CRDN_TYPE
---@param msg table
local function _send(msg_type, msg)
local s_pkt = comms.scada_packet()
local c_pkt = comms.crdn_packet()
c_pkt.make(msg_type, msg)
s_pkt.make(s_addr, self.seq_num, PROTOCOL.SCADA_CRDN, c_pkt.raw_sendable())
out_queue.push_packet(s_pkt)
self.seq_num = self.seq_num + 1
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|crdn_frame
local function _handle_packet(pkt)
-- check sequence number
if self.r_seq_num == nil then
self.r_seq_num = pkt.scada_frame.seq_num()
elseif (self.r_seq_num + 1) ~= pkt.scada_frame.seq_num() then
log.warning(log_header .. "sequence out-of-order: last = " .. self.r_seq_num .. ", new = " .. pkt.scada_frame.seq_num())
return
else
self.r_seq_num = pkt.scada_frame.seq_num()
end
-- feed watchdog
self.conn_watchdog.feed()
-- process packet
if pkt.scada_frame.protocol() == PROTOCOL.SCADA_CRDN then
---@cast pkt crdn_frame
local db = iocontrol.get_db()
-- handle packet by type
if pkt.type == CRDN_TYPE.API_GET_FAC then
local fac = db.facility
local data = {
fac.all_sys_ok,
fac.rtu_count,
fac.radiation,
{ fac.auto_ready, fac.auto_active, fac.auto_ramping, fac.auto_saturated },
{ fac.auto_current_waste_product, fac.auto_pu_fallback_active },
util.table_len(fac.tank_data_tbl),
fac.induction_data_tbl[1] ~= nil,
fac.sps_data_tbl[1] ~= nil,
}
_send(CRDN_TYPE.API_GET_FAC, data)
elseif pkt.type == CRDN_TYPE.API_GET_UNITS then
local data = {}
for i = 1, #db.units do
local u = db.units[i] ---@type ioctl_unit
table.insert(data, {
u.unit_id,
u.num_boilers,
u.num_turbines,
u.num_snas,
u.has_tank
})
end
_send(CRDN_TYPE.API_GET_UNITS, data)
else
log.debug(log_header .. "handler received unsupported CRDN packet type " .. pkt.type)
end
elseif 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 api_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 .. "PKT KEEP_ALIVE round trip time > 750ms (" .. self.last_rtt .. "ms)")
end
-- log.debug(log_header .. "PKT RTT = " .. self.last_rtt .. "ms")
-- log.debug(log_header .. "PKT TT = " .. (srv_now - api_send) .. "ms")
iocontrol.fp_pkt_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()
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, {})
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
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