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#74 supervisor-coordinator comms establish

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This commit is contained in:
Mikayla Fischler
2022-07-07 00:34:42 -04:00
parent 39672fedb4
commit ea17ba41fe
11 changed files with 379 additions and 64 deletions
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207
supervisor/session/coordinator.lua
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@@ -1,3 +1,210 @@
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 coordinator = {}
local PROTOCOLS = comms.PROTOCOLS
local SCADA_MGMT_TYPES = comms.SCADA_MGMT_TYPES
local SCADA_CRDN_TYPES = comms.SCADA_CRDN_TYPES
local print = util.print
local println = util.println
local print_ts = util.print_ts
local println_ts = util.println_ts
local PERIODICS = {
KEEP_ALIVE = 2.0
}
-- coordinator supervisor session
---@param id integer
---@param in_queue mqueue
---@param out_queue mqueue
function coordinator.new_session(id, in_queue, out_queue)
local log_header = "crdn_session(" .. id .. "): "
local self = {
id = id,
in_q = in_queue,
out_q = out_queue,
-- connection properties
seq_num = 0,
r_seq_num = nil,
connected = true,
conn_watchdog = util.new_watchdog(3),
last_rtt = 0,
-- periodic messages
periodics = {
last_update = 0,
keep_alive = 0
}
}
-- mark this coordinator session as closed, stop watchdog
local function _close()
self.conn_watchdog.cancel()
self.connected = false
end
-- send a CRDN packet
---@param msg_type SCADA_CRDN_TYPES
---@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(self.seq_num, PROTOCOLS.SCADA_CRDN, c_pkt.raw_sendable())
self.out_q.push_packet(s_pkt)
self.seq_num = self.seq_num + 1
end
-- send a SCADA management packet
---@param msg_type SCADA_MGMT_TYPES
---@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(self.seq_num, PROTOCOLS.SCADA_MGMT, m_pkt.raw_sendable())
self.out_q.push_packet(s_pkt)
self.seq_num = self.seq_num + 1
end
-- handle a packet
---@param pkt 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 >= 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() == PROTOCOLS.SCADA_MGMT then
if pkt.type == SCADA_MGMT_TYPES.KEEP_ALIVE then
-- keep alive reply
if pkt.length == 2 then
local srv_start = pkt.data[1]
local coord_send = pkt.data[2]
local srv_now = util.time()
self.last_rtt = srv_now - srv_start
if self.last_rtt > 500 then
log.warning(log_header .. "COORD KEEP_ALIVE round trip time > 500ms (" .. self.last_rtt .. "ms)")
end
log.debug(log_header .. "COORD RTT = " .. self.last_rtt .. "ms")
log.debug(log_header .. "COORD TT = " .. (srv_now - coord_send) .. "ms")
else
log.debug(log_header .. "SCADA keep alive packet length mismatch")
end
elseif pkt.type == SCADA_MGMT_TYPES.CLOSE then
-- close the session
_close()
else
log.debug(log_header .. "handler received unsupported SCADA_MGMT packet type " .. pkt.type)
end
elseif pkt.scada_frame.protocol() == PROTOCOLS.SCADA_CRDN then
if pkt.type == SCADA_MGMT_TYPES.KEEP_ALIVE then
else
end
end
end
---@class coord_session
local public = {}
-- get the session ID
function public.get_id() return self.id end
-- check if a timer matches this session's watchdog
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(SCADA_MGMT_TYPES.CLOSE, {})
println("connection to coordinator #" .. self.id .. " closed by server")
log.info(log_header .. "session closed by server")
end
-- iterate the session
---@return boolean connected
function public.iterate()
if self.connected then
------------------
-- handle queue --
------------------
local handle_start = util.time()
while self.in_q.ready() and self.connected do
-- get a new message to process
local message = self.in_q.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 coordinator " .. self.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(SCADA_MGMT_TYPES.KEEP_ALIVE, { util.time() })
periodics.keep_alive = 0
end
self.periodics.last_update = util.time()
end
return self.connected
end
return public
end
return coordinator