Add core modules for RCON Data Bridge: audit log, Base64 codec, JSON parser, config management, logging, and options registry

Contents/mods/RconDataBridge/common/media/lua/shared/RconDataBridge/RDB_Base64.lua

@@ -0,0 +1,108 @@
+---@diagnostic disable: param-type-mismatch, need-check-nil
+
+-- Minimal base64 encode/decode. Required for the request channel: RCON's
+-- command-line tokenizer (CommandBase's constructor) strips every literal
+-- double-quote character from every changeoption argument, confirmed by
+-- decompiling CommandBase, and confirmed empirically (a raw JSON payload
+-- comes out with every " removed, corrupting it beyond recovery). No quoting
+-- strategy survives this since the strip is unconditional and happens after
+-- tokenization regardless of which token form matched. Base64 has no quote
+-- characters in its alphabet, so it survives changeoption intact.
+--
+-- Only the request channel needs this: responses are written via
+-- ServerOptions:putOption (a direct Lua/Java call, not the RCON text-command
+-- path) and read via showoptions, neither of which goes through the
+-- tokenizer, so they carry raw JSON unmolested.
+
+-- TODO: does output still base64 encode? otherwise the API is weird (base64 json in, json out)
+
+RDB_Base64 = {}
+
+local ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+
+local decodeTable
+local function buildDecodeTable()
+    decodeTable = {}
+    for i = 1, #ALPHABET do
+        decodeTable[ALPHABET:sub(i, i)] = i - 1
+    end
+end
+
+function RDB_Base64.encode(data)
+    local out = {}
+    local len = #data
+    local i = 1
+    while i <= len do
+        local b1, b2, b3 = data:byte(i, i + 2)
+        b2 = b2 or 0
+        b3 = b3 or 0
+
+        local n = b1 * 65536 + b2 * 256 + b3
+
+        local c1 = math.floor(n / 262144) % 64
+        local c2 = math.floor(n / 4096) % 64
+        local c3 = math.floor(n / 64) % 64
+        local c4 = n % 64
+
+        out[#out + 1] = ALPHABET:sub(c1 + 1, c1 + 1)
+        out[#out + 1] = ALPHABET:sub(c2 + 1, c2 + 1)
+        out[#out + 1] = (i + 1 <= len) and ALPHABET:sub(c3 + 1, c3 + 1) or "="
+        out[#out + 1] = (i + 2 <= len) and ALPHABET:sub(c4 + 1, c4 + 1) or "="
+
+        i = i + 3
+    end
+    return table.concat(out)
+end
+
+function RDB_Base64.decode(str)
+    if not decodeTable then
+        buildDecodeTable()
+    end
+
+    str = str:gsub("=", "")
+    local out = {}
+    local i = 1
+    local len = #str
+    while i <= len do
+        local c1 = decodeTable[str:sub(i, i)]
+        local c2 = decodeTable[str:sub(i + 1, i + 1)]
+        local c3str = str:sub(i + 2, i + 2)
+        local c4str = str:sub(i + 3, i + 3)
+        local c3 = c3str ~= "" and decodeTable[c3str] or nil
+        local c4 = c4str ~= "" and decodeTable[c4str] or nil
+
+        if c1 == nil or c2 == nil then
+            return nil, "invalid base64 input"
+        end
+
+        local n = c1 * 262144 + c2 * 4096 + (c3 or 0) * 64 + (c4 or 0)
+
+        out[#out + 1] = string.char(math.floor(n / 65536) % 256)
+        if c3 ~= nil then
+            out[#out + 1] = string.char(math.floor(n / 256) % 256)
+        end
+        if c4 ~= nil then
+            out[#out + 1] = string.char(n % 256)
+        end
+
+        i = i + 4
+    end
+    return table.concat(out)
+end
+
+function RDB_Base64.selfTest()
+    local samples = { "", "a", "ab", "abc", '{"v":1,"id":"t1","op":"echo","args":{"x":1}}' }
+
+    for _, s in ipairs(samples) do
+        local encoded = RDB_Base64.encode(s)
+        local decoded, err = RDB_Base64.decode(encoded)
+        if err then
+            return false, "decode error for " .. s .. ": " .. err
+        end
+        if decoded ~= s then
+            return false, "round-trip mismatch for " .. s
+        end
+    end
+
+    return true
+end

Contents/mods/RconDataBridge/common/media/lua/shared/RconDataBridge/RDB_Constants.lua

@@ -0,0 +1,35 @@
+-- Shared constants: option names, protocol version, limits.
+--
+-- Option names use underscores, not dots: RCON's changeoption command validates
+-- the option-name argument against the regex \w+ (word characters only), so a
+-- dotted name is silently rejected before it ever reaches the option lookup.
+
+RDB_Constants = {}
+
+RDB_Constants.DEBUG = true
+
+RDB_Constants.PROTOCOL_VERSION = 1
+
+RDB_Constants.OPT = {
+    PROTOCOL_VERSION = "RconDataBridge_ProtocolVersion",
+    WORLD_STATS      = "RconDataBridge_WorldStats",
+    REQUEST          = "RconDataBridge_Request",
+    RESPONSE         = "RconDataBridge_Response",
+    LAST_RESPONSE    = "RconDataBridge_LastResponse",
+}
+
+RDB_Constants.PLAYER_STATS_PREFIX = "RconDataBridge_PlayerStats_"
+
+RDB_Constants.MAX_PAYLOAD_BYTES = 4096
+RDB_Constants.OPTION_MAX_LENGTH = 8192
+RDB_Constants.POLL_EVERY_TICKS  = 30
+
+RDB_Constants.ERROR_CODES = {
+    SCHEMA_ERROR      = "SCHEMA_ERROR",
+    PAYLOAD_TOO_LARGE = "PAYLOAD_TOO_LARGE",
+    OP_NOT_ALLOWED    = "OP_NOT_ALLOWED",
+    RATE_LIMITED      = "RATE_LIMITED",
+    PLAYER_NOT_FOUND  = "PLAYER_NOT_FOUND",
+    SAVE_FAILED       = "SAVE_FAILED",
+    INTERNAL_ERROR    = "INTERNAL_ERROR",
+}

Contents/mods/RconDataBridge/common/media/lua/shared/RconDataBridge/RDB_Json.lua

@@ -0,0 +1,392 @@
+---@diagnostic disable: need-check-nil
+
+-- Dependency-free JSON encode/decode. No JSON library exists anywhere in the
+-- PZ Lua API (checked exhaustively against the umbrella + zdoc-lua stub
+-- trees), so the mod brings its own minimal one.
+--
+-- encode() always produces compact output (no whitespace). This is required,
+-- not just stylistic: RCON's command tokenizer only treats double-quoted
+-- spans as a single argument, so a payload containing a literal space would
+-- be split into multiple arguments and fail parsing.
+
+RDB_Json = {}
+
+local ESCAPES = {
+    ['"']  = '\\"',
+    ['\\'] = '\\\\',
+    ['\b'] = '\\b',
+    ['\f'] = '\\f',
+    ['\n'] = '\\n',
+    ['\r'] = '\\r',
+    ['\t'] = '\\t',
+}
+
+local function encodeString(s)
+    local out = { '"' }
+
+    for i = 1, #s do
+        local c = s:sub(i, i)
+        local esc = ESCAPES[c]
+        if esc then
+            out[#out + 1] = esc
+        elseif c:byte() < 0x20 then
+            out[#out + 1] = string.format('\\u%04x', c:byte())
+        else
+            out[#out + 1] = c
+        end
+    end
+
+    out[#out + 1] = '"'
+
+    return table.concat(out)
+end
+
+local function isArray(t)
+    local n = 0
+
+    for _ in pairs(t) do
+        n = n + 1
+    end
+
+    if n == 0 then
+        return true -- empty table encodes as [] ; use {} explicitly for an empty object
+    end
+
+    for i = 1, n do
+        if t[i] == nil then
+            return false
+        end
+    end
+
+    return true
+end
+
+local encodeValue
+
+local function encodeArray(t)
+    local parts = {}
+
+    for i = 1, #t do
+        parts[i] = encodeValue(t[i])
+    end
+
+    return "[" .. table.concat(parts, ",") .. "]"
+end
+
+local function encodeObject(t)
+    local parts = {}
+
+    for k, v in pairs(t) do
+        parts[#parts + 1] = encodeString(tostring(k)) .. ":" .. encodeValue(v)
+    end
+
+    return "{" .. table.concat(parts, ",") .. "}"
+end
+
+encodeValue = function(v)
+    local t = type(v)
+
+    if v == nil then
+        return "null"
+    elseif t == "boolean" then
+        return v and "true" or "false"
+    elseif t == "number" then
+        return tostring(v)
+    elseif t == "string" then
+        return encodeString(v)
+    elseif t == "table" then
+        if isArray(v) then
+            return encodeArray(v)
+        end
+        return encodeObject(v)
+    end
+
+    error("RDB_Json.encode: unsupported type " .. t)
+end
+
+function RDB_Json.encode(value)
+    return encodeValue(value)
+end
+
+-- Decoder: simple recursive-descent parser over a string + cursor index.
+
+local function newParser(str)
+    return { str = str, pos = 1, len = #str }
+end
+
+local function peek(p)
+    if p.pos > p.len then
+        return nil
+    end
+
+    return p.str:sub(p.pos, p.pos)
+end
+
+local function skipWhitespace(p)
+    while p.pos <= p.len do
+        local c = p.str:sub(p.pos, p.pos)
+
+        if c == " " or c == "\t" or c == "\n" or c == "\r" then
+            p.pos = p.pos + 1
+        else
+            break
+        end
+    end
+end
+
+local parseValue
+
+local function parseLiteral(p, literal, value)
+    if p.str:sub(p.pos, p.pos + #literal - 1) ~= literal then
+        return nil, "expected " .. literal
+    end
+    p.pos = p.pos + #literal
+    return value
+end
+
+local function parseString(p)
+    if peek(p) ~= '"' then
+        return nil, "expected string"
+    end
+
+    p.pos = p.pos + 1
+    local out = {}
+
+    while true do
+        if p.pos > p.len then
+            return nil, "unterminated string"
+        end
+
+        local c = p.str:sub(p.pos, p.pos)
+
+        if c == '"' then
+            p.pos = p.pos + 1
+            return table.concat(out)
+        elseif c == "\\" then
+            local nextC = p.str:sub(p.pos + 1, p.pos + 1)
+
+            if nextC == "u" then
+                local hex = p.str:sub(p.pos + 2, p.pos + 5)
+                local code = tonumber(hex, 16)
+                if not code then
+                    return nil, "invalid \\u escape"
+                end
+
+                out[#out + 1] = string.char(code < 256 and code or 63)
+                p.pos = p.pos + 6
+            else
+                local unescaped = ({
+                    ['"'] = '"', ['\\'] = '\\', ['/'] = '/',
+                    b = '\b', f = '\f', n = '\n', r = '\r', t = '\t',
+                })[nextC]
+
+                if not unescaped then
+                    return nil, "invalid escape \\" .. tostring(nextC)
+                end
+
+                out[#out + 1] = unescaped
+                p.pos = p.pos + 2
+            end
+        else
+            out[#out + 1] = c
+            p.pos = p.pos + 1
+        end
+    end
+end
+
+local function parseNumber(p)
+    local start = p.pos
+
+    if peek(p) == "-" then
+        p.pos = p.pos + 1
+    end
+
+    while peek(p) and peek(p):match("%d") do
+        p.pos = p.pos + 1
+    end
+
+    if peek(p) == "." then
+        p.pos = p.pos + 1
+
+        while peek(p) and peek(p):match("%d") do
+            p.pos = p.pos + 1
+        end
+    end
+
+    if peek(p) == "e" or peek(p) == "E" then
+        p.pos = p.pos + 1
+
+        if peek(p) == "+" or peek(p) == "-" then
+            p.pos = p.pos + 1
+        end
+
+        while peek(p) and peek(p):match("%d") do
+            p.pos = p.pos + 1
+        end
+    end
+
+    local numStr = p.str:sub(start, p.pos - 1)
+    local n = tonumber(numStr)
+    if not n then
+        return nil, "invalid number"
+    end
+
+    return n
+end
+
+local function parseArray(p)
+    p.pos = p.pos + 1 -- consume [
+    local out = {}
+    skipWhitespace(p)
+
+    if peek(p) == "]" then
+        p.pos = p.pos + 1
+        return out
+    end
+
+    local i = 1
+    while true do
+        skipWhitespace(p)
+
+        local v, err = parseValue(p)
+        if err then
+            return nil, err
+        end
+
+        out[i] = v
+        i = i + 1
+        skipWhitespace(p)
+        local c = peek(p)
+
+        if c == "," then
+            p.pos = p.pos + 1
+        elseif c == "]" then
+            p.pos = p.pos + 1
+            return out
+        else
+            return nil, "expected , or ] in array"
+        end
+    end
+end
+
+local function parseObject(p)
+    p.pos = p.pos + 1 -- consume {
+    local out = {}
+    skipWhitespace(p)
+
+    if peek(p) == "}" then
+        p.pos = p.pos + 1
+        return out
+    end
+
+    while true do
+        skipWhitespace(p)
+
+        local key, err = parseString(p)
+        if err then
+            return nil, err
+        end
+
+        skipWhitespace(p)
+
+        if peek(p) ~= ":" then
+            return nil, "expected : in object"
+        end
+
+        p.pos = p.pos + 1
+        skipWhitespace(p)
+
+        local value
+        value, err = parseValue(p)
+        if err then
+            return nil, err
+        end
+
+        out[key] = value
+        skipWhitespace(p)
+
+        local c = peek(p)
+        if c == "," then
+            p.pos = p.pos + 1
+        elseif c == "}" then
+            p.pos = p.pos + 1
+            return out
+        else
+            return nil, "expected , or } in object"
+        end
+    end
+end
+
+parseValue = function(p)
+    skipWhitespace(p)
+
+    local c = peek(p)
+    if c == nil then
+        return nil, "unexpected end of input"
+    elseif c == '"' then
+        return parseString(p)
+    elseif c == "{" then
+        return parseObject(p)
+    elseif c == "[" then
+        return parseArray(p)
+    elseif c == "t" then
+        return parseLiteral(p, "true", true)
+    elseif c == "f" then
+        return parseLiteral(p, "false", false)
+    elseif c == "n" then
+        return parseLiteral(p, "null", nil)
+    elseif c == "-" or c:match("%d") then
+        return parseNumber(p)
+    end
+
+    return nil, "unexpected character " .. c
+end
+
+-- Round-trips a nested table through encode/decode and checks the result
+-- matches. Not exhaustive, just a smoke test that the codec isn't broken.
+function RDB_Json.selfTest()
+    local sample = {
+        v = 1,
+        id = "t1",
+        ok = true,
+        nested = { a = 1, b = "two", c = { 1, 2, 3 } },
+        empty = {},
+    }
+
+    local encoded = RDB_Json.encode(sample)
+    local decoded, err = RDB_Json.decode(encoded)
+
+    if err then
+        return false, "decode error: " .. err
+    end
+    if decoded.v ~= 1 or decoded.id ~= "t1" or decoded.ok ~= true then
+        return false, "top-level mismatch"
+    end
+    if decoded.nested.a ~= 1 or decoded.nested.b ~= "two" then
+        return false, "nested mismatch"
+    end
+    if #decoded.nested.c ~= 3 or decoded.nested.c[2] ~= 2 then
+        return false, "array mismatch"
+    end
+    return true
+end
+
+function RDB_Json.decode(str)
+    if type(str) ~= "string" then
+        return nil, "input is not a string"
+    end
+
+    local p = newParser(str)
+    skipWhitespace(p)
+    local value, err = parseValue(p)
+    if err then
+        return nil, err
+    end
+
+    skipWhitespace(p)
+    if p.pos <= p.len then
+        return nil, "trailing data after value"
+    end
+
+    return value
+end

Contents/mods/RconDataBridge/common/media/lua/shared/RconDataBridge/RDB_Log.lua

@@ -0,0 +1,15 @@
+RDB_Log = {}
+
+local PREFIX = "[RconDataBridge] "
+
+function RDB_Log.info(msg)
+    print(PREFIX .. "INFO:  " .. tostring(msg))
+end
+
+function RDB_Log.warn(msg)
+    print(PREFIX .. "WARN:  " .. tostring(msg))
+end
+
+function RDB_Log.error(msg)
+    print(PREFIX .. "ERROR: " .. tostring(msg))
+end