cc-mek-scada/pocket/pocket.lua
2023-06-23 14:12:41 -04:00

416 lines
17 KiB
Lua

local comms = require("scada-common.comms")
local log = require("scada-common.log")
local util = require("scada-common.util")
local coreio = require("pocket.coreio")
local PROTOCOL = comms.PROTOCOL
local DEVICE_TYPE = comms.DEVICE_TYPE
local ESTABLISH_ACK = comms.ESTABLISH_ACK
local SCADA_MGMT_TYPE = comms.SCADA_MGMT_TYPE
-- local CAPI_TYPE = comms.CAPI_TYPE
local LINK_STATE = coreio.LINK_STATE
local pocket = {}
-- pocket coordinator + supervisor communications
---@nodiscard
---@param version string pocket version
---@param nic nic network interface device
---@param pkt_channel integer pocket comms channel
---@param svr_channel integer supervisor access channel
---@param crd_channel integer coordinator access channel
---@param range integer trusted device connection range
---@param sv_watchdog watchdog
---@param api_watchdog watchdog
function pocket.comms(version, nic, pkt_channel, svr_channel, crd_channel, range, sv_watchdog, api_watchdog)
local self = {
sv = {
linked = false,
addr = comms.BROADCAST,
seq_num = 0,
r_seq_num = nil, ---@type nil|integer
last_est_ack = ESTABLISH_ACK.ALLOW
},
api = {
linked = false,
addr = comms.BROADCAST,
seq_num = 0,
r_seq_num = nil, ---@type nil|integer
last_est_ack = ESTABLISH_ACK.ALLOW
},
establish_delay_counter = 0
}
comms.set_trusted_range(range)
-- PRIVATE FUNCTIONS --
-- configure network channels
nic.closeAll()
nic.open(pkt_channel)
-- send a management packet to the supervisor
---@param msg_type SCADA_MGMT_TYPE
---@param msg table
local function _send_sv(msg_type, msg)
local s_pkt = comms.scada_packet()
local pkt = comms.mgmt_packet()
pkt.make(msg_type, msg)
s_pkt.make(self.sv.addr, self.sv.seq_num, PROTOCOL.SCADA_MGMT, pkt.raw_sendable())
nic.transmit(svr_channel, pkt_channel, s_pkt)
self.sv.seq_num = self.sv.seq_num + 1
end
-- send a management packet to the coordinator
---@param msg_type SCADA_MGMT_TYPE
---@param msg table
local function _send_crd(msg_type, msg)
local s_pkt = comms.scada_packet()
local pkt = comms.mgmt_packet()
pkt.make(msg_type, msg)
s_pkt.make(self.api.addr, self.api.seq_num, PROTOCOL.SCADA_MGMT, pkt.raw_sendable())
nic.transmit(crd_channel, pkt_channel, s_pkt)
self.api.seq_num = self.api.seq_num + 1
end
-- send a packet to the coordinator API
-----@param msg_type CAPI_TYPE
-----@param msg table
-- local function _send_api(msg_type, msg)
-- local s_pkt = comms.scada_packet()
-- local pkt = comms.capi_packet()
-- pkt.make(msg_type, msg)
-- s_pkt.make(self.api.addr, self.api.seq_num, PROTOCOL.COORD_API, pkt.raw_sendable())
-- nic.transmit(crd_channel, pkt_channel, s_pkt)
-- self.api.seq_num = self.api.seq_num + 1
-- end
-- attempt supervisor connection establishment
local function _send_sv_establish()
_send_sv(SCADA_MGMT_TYPE.ESTABLISH, { comms.version, version, DEVICE_TYPE.PKT })
end
-- attempt coordinator API connection establishment
local function _send_api_establish()
_send_crd(SCADA_MGMT_TYPE.ESTABLISH, { comms.version, version, DEVICE_TYPE.PKT })
end
-- keep alive ack to supervisor
---@param srv_time integer
local function _send_sv_keep_alive_ack(srv_time)
_send_sv(SCADA_MGMT_TYPE.KEEP_ALIVE, { srv_time, util.time() })
end
-- keep alive ack to coordinator
---@param srv_time integer
local function _send_api_keep_alive_ack(srv_time)
_send_crd(SCADA_MGMT_TYPE.KEEP_ALIVE, { srv_time, util.time() })
end
-- PUBLIC FUNCTIONS --
---@class pocket_comms
local public = {}
-- close connection to the supervisor
function public.close_sv()
sv_watchdog.cancel()
self.sv.linked = false
self.sv.r_seq_num = nil
self.sv.addr = comms.BROADCAST
_send_sv(SCADA_MGMT_TYPE.CLOSE, {})
end
-- close connection to coordinator API server
function public.close_api()
api_watchdog.cancel()
self.api.linked = false
self.api.r_seq_num = nil
self.api.addr = comms.BROADCAST
_send_crd(SCADA_MGMT_TYPE.CLOSE, {})
end
-- close the connections to the servers
function public.close()
public.close_sv()
public.close_api()
end
-- attempt to re-link if any of the dependent links aren't active
function public.link_update()
if not self.sv.linked then
coreio.report_link_state(util.trinary(self.api.linked, LINK_STATE.API_LINK_ONLY, LINK_STATE.UNLINKED))
if self.establish_delay_counter <= 0 then
_send_sv_establish()
self.establish_delay_counter = 4
else
self.establish_delay_counter = self.establish_delay_counter - 1
end
elseif not self.api.linked then
coreio.report_link_state(LINK_STATE.SV_LINK_ONLY)
if self.establish_delay_counter <= 0 then
_send_api_establish()
self.establish_delay_counter = 4
else
self.establish_delay_counter = self.establish_delay_counter - 1
end
else
-- linked, all good!
coreio.report_link_state(LINK_STATE.LINKED)
end
end
-- parse a packet
---@param side string
---@param sender integer
---@param reply_to integer
---@param message any
---@param distance integer
---@return mgmt_frame|capi_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 SCADA management packet
if 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
-- get as coordinator API packet
elseif s_pkt.protocol() == PROTOCOL.COORD_API then
local capi_pkt = comms.capi_packet()
if capi_pkt.decode(s_pkt) then
pkt = capi_pkt.get()
end
else
log.debug("attempted parse of illegal packet type " .. s_pkt.protocol(), true)
end
end
return pkt
end
-- handle a packet
---@param packet mgmt_frame|capi_frame|nil
function public.handle_packet(packet)
if packet ~= nil then
local l_chan = packet.scada_frame.local_channel()
local r_chan = packet.scada_frame.remote_channel()
local protocol = packet.scada_frame.protocol()
local src_addr = packet.scada_frame.src_addr()
if l_chan ~= pkt_channel then
log.debug("received packet on unconfigured channel " .. l_chan, true)
elseif r_chan == crd_channel then
-- check sequence number
if self.api.r_seq_num == nil then
self.api.r_seq_num = packet.scada_frame.seq_num()
elseif self.connected and ((self.api.r_seq_num + 1) ~= packet.scada_frame.seq_num()) then
log.warning("sequence out-of-order (API): last = " .. self.api.r_seq_num .. ", new = " .. packet.scada_frame.seq_num())
return
elseif self.api.linked and (src_addr ~= self.api.addr) then
log.debug("received packet from unknown computer " .. src_addr .. " while linked (API expected " .. self.api.addr ..
"); channel in use by another system?")
return
else
self.api.r_seq_num = packet.scada_frame.seq_num()
end
-- feed watchdog on valid sequence number
api_watchdog.feed()
if protocol == PROTOCOL.COORD_API then
---@cast packet capi_frame
elseif protocol == PROTOCOL.SCADA_MGMT then
---@cast packet mgmt_frame
if packet.type == SCADA_MGMT_TYPE.ESTABLISH then
-- connection with coordinator established
if packet.length == 1 then
local est_ack = packet.data[1]
if est_ack == ESTABLISH_ACK.ALLOW then
log.info("coordinator connection established")
self.establish_delay_counter = 0
self.api.linked = true
self.api.addr = src_addr
if self.sv.linked then
coreio.report_link_state(LINK_STATE.LINKED)
else
coreio.report_link_state(LINK_STATE.API_LINK_ONLY)
end
elseif est_ack == ESTABLISH_ACK.DENY then
if self.api.last_est_ack ~= est_ack then
log.info("coordinator connection denied")
end
elseif est_ack == ESTABLISH_ACK.COLLISION then
if self.api.last_est_ack ~= est_ack then
log.info("coordinator connection denied due to collision")
end
elseif est_ack == ESTABLISH_ACK.BAD_VERSION then
if self.api.last_est_ack ~= est_ack then
log.info("coordinator comms version mismatch")
end
else
log.debug("coordinator SCADA_MGMT establish packet reply unsupported")
end
self.api.last_est_ack = est_ack
else
log.debug("coordinator SCADA_MGMT establish packet length mismatch")
end
elseif self.api.linked then
if packet.type == SCADA_MGMT_TYPE.KEEP_ALIVE then
-- keep alive request received, echo back
if packet.length == 1 then
local timestamp = packet.data[1]
local trip_time = util.time() - timestamp
if trip_time > 750 then
log.warning("pocket coordinator KEEP_ALIVE trip time > 750ms (" .. trip_time .. "ms)")
end
-- log.debug("pocket coordinator RTT = " .. trip_time .. "ms")
_send_api_keep_alive_ack(timestamp)
else
log.debug("coordinator SCADA keep alive packet length mismatch")
end
elseif packet.type == SCADA_MGMT_TYPE.CLOSE then
-- handle session close
api_watchdog.cancel()
self.api.linked = false
self.api.r_seq_num = nil
self.api.addr = comms.BROADCAST
log.info("coordinator server connection closed by remote host")
else
log.debug("received unknown SCADA_MGMT packet type " .. packet.type .. " from coordinator")
end
else
log.debug("discarding coordinator non-link SCADA_MGMT packet before linked")
end
else
log.debug("illegal packet type " .. protocol .. " from coordinator", true)
end
elseif r_chan == svr_channel then
-- check sequence number
if self.sv.r_seq_num == nil then
self.sv.r_seq_num = packet.scada_frame.seq_num()
elseif self.connected and ((self.sv.r_seq_num + 1) ~= packet.scada_frame.seq_num()) then
log.warning("sequence out-of-order (SVR): last = " .. self.sv.r_seq_num .. ", new = " .. packet.scada_frame.seq_num())
return
elseif self.sv.linked and (src_addr ~= self.sv.addr) then
log.debug("received packet from unknown computer " .. src_addr .. " while linked (SVR expected " .. self.sv.addr ..
"); channel in use by another system?")
return
else
self.sv.r_seq_num = packet.scada_frame.seq_num()
end
-- feed watchdog on valid sequence number
sv_watchdog.feed()
-- handle packet
if protocol == PROTOCOL.SCADA_MGMT then
---@cast packet mgmt_frame
if packet.type == SCADA_MGMT_TYPE.ESTABLISH then
-- connection with supervisor established
if packet.length == 1 then
local est_ack = packet.data[1]
if est_ack == ESTABLISH_ACK.ALLOW then
log.info("supervisor connection established")
self.establish_delay_counter = 0
self.sv.linked = true
self.sv.addr = src_addr
if self.api.linked then
coreio.report_link_state(LINK_STATE.LINKED)
else
coreio.report_link_state(LINK_STATE.SV_LINK_ONLY)
end
elseif est_ack == ESTABLISH_ACK.DENY then
if self.sv.last_est_ack ~= est_ack then
log.info("supervisor connection denied")
end
elseif est_ack == ESTABLISH_ACK.COLLISION then
if self.sv.last_est_ack ~= est_ack then
log.info("supervisor connection denied due to collision")
end
elseif est_ack == ESTABLISH_ACK.BAD_VERSION then
if self.sv.last_est_ack ~= est_ack then
log.info("supervisor comms version mismatch")
end
else
log.debug("supervisor SCADA_MGMT establish packet reply unsupported")
end
self.sv.last_est_ack = est_ack
else
log.debug("supervisor SCADA_MGMT establish packet length mismatch")
end
elseif self.sv.linked then
if packet.type == SCADA_MGMT_TYPE.KEEP_ALIVE then
-- keep alive request received, echo back
if packet.length == 1 then
local timestamp = packet.data[1]
local trip_time = util.time() - timestamp
if trip_time > 750 then
log.warning("pocket supervisor KEEP_ALIVE trip time > 750ms (" .. trip_time .. "ms)")
end
-- log.debug("pocket supervisor RTT = " .. trip_time .. "ms")
_send_sv_keep_alive_ack(timestamp)
else
log.debug("supervisor SCADA keep alive packet length mismatch")
end
elseif packet.type == SCADA_MGMT_TYPE.CLOSE then
-- handle session close
sv_watchdog.cancel()
self.sv.linked = false
self.sv.r_seq_num = nil
self.sv.addr = comms.BROADCAST
log.info("supervisor server connection closed by remote host")
else
log.debug("received unknown SCADA_MGMT packet type " .. packet.type .. " from supervisor")
end
else
log.debug("discarding supervisor non-link SCADA_MGMT packet before linked")
end
else
log.debug("illegal packet type " .. protocol .. " from supervisor", true)
end
else
log.debug("received packet from unconfigured channel " .. r_chan, true)
end
end
end
-- check if we are still linked with the supervisor
---@nodiscard
function public.is_sv_linked() return self.sv.linked end
-- check if we are still linked with the coordinator
---@nodiscard
function public.is_api_linked() return self.api.linked end
return public
end
return pocket