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--
-- ~~~ fetch a pawsd service
--
-- require a name & service index to fetch
if not arg[1] or not arg[2] then
error("server name & index required")
end
-- imports
local PawSD = require("src/pawsd")
local Servers = require("src/servers")
require("src/utils")
local socket = require("socket")
local client = assert(socket.tcp())
-- get arguments & check validity
local server = Servers[arg[1]]
local index = arg[2]
if not server then
error("server not found")
end
-- connect to client
client:connect(server.host, server.port)
-- send request
local request = string.fromhex(PawSD.Magic.REQUEST .. PawSD.Version .. PawSD.Verbs.FETCH_SERVICE .. server.keyalg .. "0020" .. server.key .. index)
client:send(request)
-- print response
local response = {}
while true do
local packet, status = client:receive(1)
-- if packet then print(response) end
table.insert(response, packet)
if status == "closed" then break end
end
-- check that the response is correct
local responseMagic = extractfromresponse(response, 1, 8)
if not responseMagic == PawSD.Magic.RESPONSE then
error("invalid response")
end
-- check that the status is okay
local responseStatus = extractfromresponse(response, 11, 12)
if not responseStatus == PawSD.Responses.OK then
error("unsuccessful request")
end
-- get signature information
local responseSignatureLength = tonumber(extractfromresponse(response, 13, 14), 16)
local responseSignatureEnd = 14 + responseSignatureLength
local responseSignature = extractfromresponse(response, 15, responseSignatureEnd)
print("Signature: " .. responseSignature)
-- todo: check this?
-- get service index
local responseIndexStart = responseSignatureEnd + 1
local responseIndex = extractfromresponse(response, responseIndexStart, responseIndexStart + 1)
-- get service flags
local responseFlagsStart = responseIndexStart + 2
local responseFlags = extractfromresponse(response, responseFlagsStart, responseFlagsStart + 3)
-- get number of records
local responseRecordCountStart = responseFlagsStart + 4
local responseRecordCount = tonumber(extractfromresponse(response, responseRecordCountStart, responseRecordCountStart + 1), 16)
-- store offset
local recordOffset = responseRecordCountStart + 2
-- loop through each record
for recordNumber = 1, responseRecordCount, 1 do
print("\n--- Record Number " .. recordNumber .. " ---")
-- get number of tags
local responseTagCountStart = recordOffset
local responseTagCount = tonumber(extractfromresponse(response, responseTagCountStart, responseTagCountStart + 1), 16)
-- store offset
local tagOffset = recordOffset + 2
-- loop through each tag
for tagNumber = 1, responseTagCount, 1 do
print("\n - Tag Number " .. tagNumber .. " -\n")
-- high tag
local responseTagHighStart = tagOffset
local responseTagHigh = extractfromresponse(response, responseTagHighStart, responseTagHighStart + 7)
print(" High Tag: " .. responseTagHigh)
-- low tag
local responseTagLowStart = responseTagHighStart + 8
local responseTagLow = extractfromresponse(response, responseTagLowStart, responseTagLowStart + 7)
print(" Low Tag: " .. responseTagLow)
-- get value length
local responseTagValueLength = {}
local responseTagValueLengthStart = responseTagLowStart + 8
local responseTagValueLength = tonumber(extractfromresponse(response, responseTagValueLengthStart, responseTagValueLengthStart + 3), 16)
-- only check if value actually exists
if responseTagValueLength > 0 then
-- get value
local responseTagValueStart = responseTagValueLengthStart + 4
local responseTagValueEnd = responseTagValueStart + responseTagValueLength
local responseTagValue = string.fromhex(extractfromresponse(response, responseTagValueStart, responseTagValueEnd))
print(" Value: " .. responseTagValue)
-- adjust offset
tagOffset = responseTagValueEnd
else
-- adjust offset
tagOffset = responseTagValueLengthStart + 4
end
end
-- adjust offset
recordOffset = tagOffset
end
-- close connection
client:close()
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