[fetch] added pretty output for service look-ups

3 files changed, 127 insertions, 4 deletions

diff --git a/fetch.lua b/fetch.lua
index 59c8e3c..43e268f 100644
--- a/fetch.lua
+++ b/fetch.lua
@@ -27,16 +27,111 @@ end
 client:connect(server.host, server.port)
 
 -- send request
-local request = string.fromhex(PawSD.Magic .. PawSD.Version .. PawSD.Verbs.FETCH_SERVICE .. server.keyalg .. "0020" .. server.key .. index)
+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 response, status = client:receive(1)
+    local packet, status = client:receive(1)
 
-    if response then print(response) end
+    -- 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()
diff --git a/src/pawsd.lua b/src/pawsd.lua
index 8efae57..4c7f82f 100644
--- a/src/pawsd.lua
+++ b/src/pawsd.lua
@@ -9,7 +9,11 @@ local verbs = {
 }
 
 -- metadata
-local magic = "5061775271757374" -- PawRqust
+local magic = {
+    REQUEST = "5061775271757374", -- PawRqust
+    RESPONSE = "5061775273706E73" -- PawRspns
+}
+
 local version = "0001"
 
 -- supported key algorithms
@@ -17,9 +21,21 @@ local keyalg = {
     ED25519 = "63af"
 }
 
+-- response codes
+local responses = {
+    OK = "0200",
+    CLIENT_ERROR = "0400",
+    NOT_FOUND = "0404",
+    SERVER_ERROR = "0500",
+    NOT_IMPLEMENTED = "0501",
+    UNAVAILABLE = "0503",
+    UNKNOWN = "0505"
+}
+
 -- return
 return {
     Verbs = verbs,
+    Responses = responses,
     Magic = magic,
     Version = version,
     KeyAlg = keyalg
diff --git a/src/utils.lua b/src/utils.lua
index af6e91f..5bcbc8c 100644
--- a/src/utils.lua
+++ b/src/utils.lua
@@ -15,3 +15,15 @@ function string.fromhex(str)
         return string.char(tonumber(cc, 16))
     end))
 end
+
+-- get information from the pawsd response
+function extractfromresponse(response, start, last)
+
+    local result = {}
+
+    table.move(response, start, last, 1, result)
+    result = string.tohex(table.concat(result))
+
+    return result
+
+end