FTP rework

Libraries/FTP.lua

@@ -0,0 +1,928 @@
+local event = require("Event")
+local filesystem = require("Filesystem")
+
+local FTP = {}
+
+----------------------------------------------------------------------------------------------------------------
+
+-- Connect to address:port and wait for the socket to finish connection until timeout exceeded
+local function socketConnect(address, port, timeout)
+    local socket, reason = component.get("internet").connect(address, port)
+
+    local connectionStartTime = computer.uptime()
+    while true do
+        local success, reason = socket.finishConnect()
+        if success then
+            return socket
+        end
+
+        if success == nil then
+            return nil, reason
+        end
+
+        if computer.uptime() - connectionStartTime > timeout then
+            return nil, "connection timed out"
+        end
+    end    
+end
+
+-- Wait for internet_ready event until timeout exceeded
+local function socketAwait(socket, timeout)
+    local startTime = computer.uptime()
+
+    while true do
+        local eventType, _, socketId = event.pull(timeout - (computer.uptime() - startTime))
+
+        if not eventType then
+            return false
+        end
+
+        if eventType == "internet_ready" and socketId == socket.id() then
+            return true
+        end
+    end
+end
+
+-- Read remaining data from the socket
+local function socketReceive(socket)
+    local data = ""
+
+    while true do
+        local chunk = socket.read()
+
+        if not chunk or #chunk == 0 then
+            break
+        end
+
+        data = data .. chunk
+    end
+
+    return data
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+-- FTP response line iterator
+function FTP.lines(data)
+    return data:gmatch("([^\r\n]+)\r\n")
+end
+
+-- Convert FTP modification time into unix timestamp
+function FTP.parseTimestamp(timestamp)
+    local year, month, day, hour, min, sec = timestamp:match("(%d%d%d%d)(%d%d)(%d%d)(%d%d)(%d%d)(%d%d)")
+
+    return os.time({
+        year = tonumber(year),
+        month = tonumber(month),
+        day = tonumber(day),
+        hour = tonumber(hour),
+        min = tonumber(min),
+        sec = tonumber(sec)                        
+    })    
+end
+
+-- File information returned by MLSD/MLST commands follows key=value; format:
+-- type=dir;sizd=4096;modify=20240924194606; home
+function FTP.parseFileInfo(fileInfo)
+    local info = {}
+
+    for token in fileInfo:gmatch("[^; ]+") do
+        local key, value = token:match("(.+)=(.+)")
+
+        if key then
+            key = key:lower()
+
+            if key == "type" then
+                info.isdir = not not value:match("dir")
+            elseif key:match("siz.") then
+                info.size = tonumber(value)
+            elseif key == "modify" then
+                info.modify = FTP.parseTimestamp(value)
+            end
+        else
+            info.name = token
+        end
+    end    
+
+    return info
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+-- Receive and parse FTP command response 
+-- If the function succeedes, the return values will be first responses and a table containing all parsed responses
+-- Most of the time second value may be discarded, though it may be useful when sending multiple commands in a single request
+local function FTPReceiveResponse(self)
+    if not socketAwait(self.controlSocket, self.responseTimeout) then
+        return nil, "response timed out"
+    end
+
+    local data, reason = socketReceive(self.controlSocket)
+    if not data then
+        return nil, reason
+    end
+
+    local responses, response = {}
+    for line in data:gmatch("[^\r\n]+\r\n") do
+        if not response then 
+            response = {
+                content = ""
+            }
+        end
+
+        local status, delimiter, content = line:match("(%d%d%d)([ -])(.+\r\n)")
+
+        if status then
+            response.content = response.content .. content
+
+            -- Space after the status code indicates the last line of the response
+            if delimiter == " " then
+                response.status = tonumber(status)
+                response.ok = 100 <= response.status and response.status < 400
+
+                table.insert(responses, response)
+                response = nil                
+            end
+        else
+            response.content = response.content .. line
+        end
+    end
+    
+    if #responses < 1 then
+        return nil, "no parsable responses"
+    end
+
+    return responses[1], responses
+end
+
+-- Send FTP command and receive response
+-- command argument may be either a string or a table containing multiple commands
+local function FTPSendCommand(self, command)
+    command = (type(command) == "table" and table.concat(command, "\r\n") or command) .. "\r\n"
+
+    -- Seems like windows IIS ftp server doesn't like large command blobs
+    for i = 1, math.ceil(#command / self.commandChunkSize) do
+        local result, reason = self.controlSocket.write(
+            command:sub(
+                self.commandChunkSize * (i - 1) + 1, 
+                self.commandChunkSize * i
+            )
+        )
+    
+        if not result then
+            return nil, reason
+        end
+    end
+
+    return self:receiveResponse()
+end
+
+-- Enter passive mode, send command and read data connection
+local function FTPSendPassiveModeCommand(self, command)
+    local result, reason = self:beginNegotiation()
+    if not result then
+        return nil, reason
+    end
+
+    local response, reason = self:sendCommand(command)
+    if not response then
+        self:endNegotiation()
+        return nil, reason
+    end    
+
+    if not response.ok then
+        self:endNegotiation()
+        return nil, "command failed: " .. response.content
+    end
+
+    local data, reason = self:receiveData()
+    self:endNegotiation()
+
+    if not data then
+        return nil, reason
+    end
+
+    return data
+end
+
+-- Enter passive mode and establish data connection
+local function FTPBeginNegotiation(self)
+    if self.dataSocket then
+        return nil, "data connection already open"
+    end
+
+    local response, reason = self:sendCommand("PASV")
+    if not response then
+        return nil, reason
+    end
+
+    if not response.ok then
+        return nil, "unable to enter passive mode: " .. response.content
+    end
+
+    local digits = {response.content:match("(%d+),(%d+),(%d+),(%d+),(%d+),(%d+)")}
+    if #digits ~= 6 then
+        return nil, "unable to enter passive mode: malformed response"
+    end
+
+    local dataSocket, reason = socketConnect(
+        table.concat(digits, ".", 1, 4), 
+        tonumber(digits[5]) * 256 + tonumber(digits[6]),
+        self.responseTimeout
+    )
+
+    if not dataSocket then
+        return nil, reason
+    end
+
+    self.dataSocket = dataSocket
+    return true
+end
+
+-- Close data connection
+local function FTPEndNegotiation(self)
+    if not self.dataSocket then
+        return nil, "data connection was not open"
+    end
+
+    self.dataSocket.close()
+    self.dataSocket = nil
+
+    return true
+end
+
+-- Read data response
+local function FTPReceiveData(self)
+    if not self.dataSocket then
+        return nil, "data connection was not open"
+    end
+
+    return socketReceive(self.dataSocket)
+end
+
+-- Send data through the data connection
+local function FTPSendData(self, data)
+    if not self.dataSocket then
+        return nil, "data connection was not open"
+    end
+
+    return self.dataSocket.write(data)
+end
+
+-- Close FTP connection
+local function FTPClose(self)
+    if self.controlSocket then
+        self.controlSocket.close()
+        self.controlSocket = nil
+    end
+
+    if self.dataSocket then
+        self.dataSocket.close()
+        self.dataSocket = nil
+    end
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+local function pizda(response)
+    return not response or not response.ok
+end
+
+local function cyka(response, ...)
+    if not response then
+        return nil, ...
+    end
+
+    if not response.ok then
+        return nil, response.content
+    end
+end
+
+local function getParentDirectory(path)
+    local directory, filename = path:match("^(.*/)([^/]+)/?$")
+    if not directory then
+        return nil, path
+    end
+
+    return directory, filename
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+local function FTPSetCacheValue(self, key, value)
+    self.cache[key] = value ~= nil and {computer.uptime(), value} or nil
+end
+
+local function FTPGetCacheValue(self, key)
+    local currentTime = computer.uptime()
+    for key, entry in pairs(self.cache) do
+        if currentTime - entry[1] > self.cacheTimeout then
+            self.cache[key] = nil
+        end
+    end
+
+    local entry = self.cache[key]
+    if entry then
+        return entry[2]
+    end
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+-- Keep connection alive
+local function FTPKeepAlive(self)
+    local response, reason = self:sendCommand("PWD")
+    if not response then
+        return nil, reason
+    end
+
+    return true
+end
+
+-- Login
+local function FTPLogin(self, username, password)
+    local response, reason = self:sendCommand("USER " .. username)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    local response, reason = self:sendCommand("PASS " .. password)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    return true
+end
+
+-- Set negotiation mode
+local function FTPSetMode(self, mode)
+    local response, reason = self:sendCommand("TYPE " .. mode)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    return true
+end
+
+-- Get working directory
+local function FTPGetWorkingDirectory(self, useCache)
+    if self.cacheTimeout and useCache then
+        local cache = self:getCacheValue("getWorkingDirectory")
+
+        if cache then
+            return cache
+        end
+    end
+
+    local response, reason = self:sendCommand("PWD")
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    local path = response.content:match("\"(.+)\"")
+    if not path then
+        return nil, "unexpected response: " .. response.content
+    end
+
+    if self.cacheTimeout then
+        self:setCacheValue("getWorkingDirectory", path)
+    end
+
+    return path
+end
+
+-- Set working directory
+local function FTPChangeWorkingDirectory(self, path)
+    if self.cacheTimeout then
+        self:setCacheValue("getWorkingDirectory")
+    end
+
+    local response, reason = self:sendCommand("CWD " .. path)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+    
+    return true
+end
+
+-- Get file size
+local function FTPGetFileSize(self, path)
+    local response, reason = self:sendCommand("SIZE " .. path)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+    
+    return tonumber(response.content)
+end
+
+-- Returns absolute path
+local function FTPResolvePath(self, path, useCache)
+    if path:match("^/.*") then
+        return path
+    end
+
+    local directory, reason = self:getWorkingDirectory(useCache)
+    if not directory then
+        return nil, reason
+    end
+
+    return directory .. "/" .. path
+end
+
+-- This function is used internally by listDirectory and fileInfo methods
+local function FTPRequestFilesInformation(self, fileNames)
+    local commands = { "PWD" }
+
+    for _, path in pairs(fileNames) do
+        -- One way to find out whether entry is directory or not without MLSD/MLST is to try to CWD to it
+        table.insert(commands, "CWD "  .. path)
+        table.insert(commands, "MDTM " .. path)
+        table.insert(commands, "SIZE " .. path)
+    end
+    
+    local success, responsesOrReason = self:sendCommand(commands)
+    if not success then
+        return nil, responsesOrReason
+    end
+    
+    local workingDirectory = table.remove(responsesOrReason, 1).content:match("\"(.+)\"")
+
+    local list = {}
+    for _, path in pairs(fileNames) do
+        local entry = {}
+        entry.name = path:match("/([^/]+)$") or path
+        entry.isdir = table.remove(responsesOrReason, 1).ok
+
+        local response = table.remove(responsesOrReason, 1)
+        entry.modify = response.ok and FTP.parseTimestamp(response.content) or 0
+
+        local response = table.remove(responsesOrReason, 1)
+        entry.size = response.ok and tonumber(response.content) or 0
+
+        table.insert(list, entry)
+    end
+
+    self:changeWorkingDirectory(workingDirectory)
+    return list
+end
+
+-- List directory entries with their type, size and modification time
+local function FTPListDirectory(self, path, useCache)
+    local reason
+    path, reason = self:resolvePath(path, useCache)
+    if not path then
+        return nil, "unable to resolve path: " .. reason
+    end
+
+    local cacheKey = "listDirectory@" .. path
+    if self.cacheTimeout and useCache then
+        local cache = self:getCacheValue(cacheKey)
+
+        if cache then
+            return cache
+        end
+    end
+
+    local list = {}
+    if self.features.MLSD then
+        local data, reason = self:sendPassiveModeCommand("MLSD " .. path)
+        if not data then
+            return nil, reason
+        end
+
+        for line in FTP.lines(data) do
+            local info = FTP.parseFileInfo(line)
+
+            if not info.name:match("[^%.]*%.%.?$") then
+                table.insert(list, info)
+            end
+        end
+    else
+        -- No MLSD :(
+        local data, reason = self:sendPassiveModeCommand("NLST " .. path)
+        if not data then
+            return nil, reason
+        end
+
+        local fileNames = {}
+        for name in FTP.lines(data) do
+            if not name:match("[^%.]*%.%.?$") then
+                table.insert(fileNames, name)
+            end
+        end
+
+        local reason
+        list, reason = self:requestFilesInformation(fileNames)
+        if not list then
+            return nil, reason
+        end
+    end
+
+    -- Sort files by name
+    table.sort(
+        list,
+        function(a, b)
+            return a.name < b.name
+        end
+    )
+
+    if self.cacheTimeout then
+        self:setCacheValue(cacheKey, list)
+    end
+
+    return list
+end
+
+-- Returns information about the requested file
+local function FTPGetFileInfo(self, path, useCache)
+    local reason
+    path, reason = self:resolvePath(path, useCache)
+    if not path then
+        return nil, "unable to resolve path: " .. reason
+    end
+
+    local cacheKey = "getFileInfo@" .. path
+    if self.cacheTimeout and useCache then
+        -- Check for getFileInfo cache
+        local cache = self:getCacheValue(cacheKey)
+        if cache then
+            return cache
+        end
+
+        -- Check for listDirectory cache
+        local directory, filename = getParentDirectory(path)
+        if directory then
+            local cache = self:getCacheValue("listDirectory@" .. directory)
+            
+            if cache then
+                for i = 1, #cache do
+                    if cache[i].name == filename then
+                        return cache[i]
+                    end
+                end
+            end
+        end
+    end
+
+    local info
+    if self.features.MLST then
+        local response, reason = self:sendCommand("MLST " .. path)
+        if not response then
+            return nil, reason
+        end
+
+        local data = response.content:match("^ ([^\r\n]+)\r\n$")
+        if not data then
+            return nil, "unparsable response"
+        end
+
+        info = FTP.parseFileInfo(data)
+    else
+        local result, reason = self:requestFilesInformation({ path })
+        if not result then
+            return nil, reason
+        end
+
+        info = result[1]
+    end
+
+    if self.cacheTimeout then
+        self:setCacheValue(cacheKey, info)
+    end
+
+    return info
+end
+
+local function FTPFileExists(self, path, useCache)
+    local directory, filename = getParentDirectory(path)
+    if directory == "/" then
+        return true
+    end
+
+    local list, reason = self:listDirectory(directory or "", useCache)
+    if not list then
+        return nil, reason
+    end
+
+    for i = 1, #list do
+        if list[i].name == filename then
+            return true
+        end
+    end
+
+    return false
+end
+
+-- Delete file or directory recursively
+local function FTPRemoveFile(self, path, useCache)
+    local info, reason = self:getFileInfo(path, useCache)
+    if not info then
+        return nil, reason
+    end
+
+    if info.isdir then
+        local list = self:listDirectory(path, useCache)
+        for i = 1, #list do
+            if list[i].name ~= "." and list[i].name ~= ".." then
+                local success, reason = self:removeFile((path .. "/" .. list[i].name):gsub("/+", "/"))
+                
+                if not success then
+                    return nil, reason
+                end
+            end
+        end
+        
+        local response, reason = self:sendCommand("RMD " .. path)
+        if pizda(response) then
+            return cyka(response, reason)
+        end
+    else
+        local response, reason = self:sendCommand("DELE " .. path)
+        if pizda(response) then
+            return cyka(response, reason)
+        end
+    end
+
+    return true
+end
+
+-- Create directory
+local function FTPMakeDirectory(self, path)
+    local response, reason = self:sendCommand("MKD " .. path)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    return true
+end
+
+-- Rename file
+local function FTPRenameFile(self, from, to)
+    local response, reason = self:sendCommand("RNFR " .. from)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    local response, reason = self:sendCommand("RNTO " .. to)
+    if pizda(response) then
+        return cyka(response, reason)
+    end
+
+    return true
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+-- Read file by path
+-- Each received fragment is passed into callback function
+local function FTPReadFile(self, path, callback, chunkSize)
+    local result, reason = self:beginNegotiation()
+    if not result then
+        return nil, "negotiation failed: " .. result
+    end
+
+    local response, reason = self:sendCommand("RETR " .. path)
+    if pizda(response) then
+        self:endNegotiation()
+        return cyka(response, reason)
+    end
+    
+    while true do
+        local chunk, reason = self.dataSocket.read(chunkSize or math.huge)
+        if not chunk or #chunk == 0 then
+            self:endNegotiation()
+
+            if reason then
+                return nil, "unable to receive data: " .. reason
+            end
+
+            break
+        end
+
+        local success, reason = pcall(callback, chunk)
+        if not success then
+            self:endNegotiation()
+            return nil, "callback error: " .. reason
+        end
+    end
+
+    self:endNegotiation()
+    return true
+end
+
+-- Read whole remote file into the memory
+local function FTPReadFileToMemory(self, path)
+    local buffer = ""
+    local success, reason = self:readFile(
+        path,
+        function(chunk)
+            buffer = buffer .. chunk
+        end
+    )
+
+    if not success then
+        return nil, reason
+    end
+
+    return buffer
+end
+
+-- Read whole remote file into the local filesystem
+local function FTPReadFileToFilesystem(self, path, savePath)
+    local file = filesystem.open(savePath, "w")
+    if not file then
+        return nil, "could not open file for writing"
+    end
+
+    local success, reason = self:readFile(
+        path,
+        function(chunk)
+            file:write(chunk)
+        end
+    )
+
+    file:close()
+    return not not success, reason
+end
+
+-- Write file
+-- Data is obtained from the callback function until it returns nil
+local function FTPWriteFile(self, path, callback)
+    local result, reason = self:beginNegotiation()
+    if not result then
+        return nil, "negotiation failed: " .. result
+    end
+
+    local response, reason = self:sendCommand("STOR " .. path)
+    if pizda(response) then
+        self:endNegotiation()
+        return cyka(response, reason)
+    end
+    
+    while true do
+        local sucess, chunkOrReason = pcall(callback)
+        if not sucess then
+            self:endNegotiation()
+            return false, "callback error: " .. chunkOrReason
+        end
+
+        if not chunkOrReason then
+            break
+        end
+
+        self:sendData(chunkOrReason)
+    end
+
+    self:endNegotiation()
+
+    local result, reason = self:receiveResponse()
+    if not result or not result.ok then
+        return nil, reason or result.content
+    end
+
+    return true
+end
+
+-- Write file from memory
+local function FTPWriteFileFromMemory(self, path, data)
+    local chunkSize = 8192
+    local chunkIndex = 0
+
+    local result, reason = self:writeFile(
+        path,
+        function()
+            local chunk = data:sub(chunkIndex * chunkSize + 1, (chunkIndex + 1) * chunkSize)
+            chunkIndex = chunkIndex + 1
+
+            if #chunk == 0 then
+                return
+            end
+
+            return chunk
+        end
+    )
+
+    if not result then
+        return nil, reason
+    end
+
+    return true
+end
+
+-- Write file from local filesystem
+local function FTPWriteFileFromFilesystem(self, path, localPath)
+    local file, reason = filesystem.open(localPath, "r")
+    if not file then
+        return nil, reason
+    end
+
+    local result, reason = self:writeFile(
+        path,
+        function()
+            local chunk = file:read(math.huge)
+            if not chunk or #chunk == 0 then
+                return
+            end
+
+            return chunk
+        end
+    )
+
+    file:close()
+
+    if not result then
+        return nil, reason
+    end
+
+    return true
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+-- Connect to the FTP server
+function FTP.connect(address, port, responseTimeout)
+    local self = {}
+
+    self.commandChunkSize = 256
+
+    self.responseTimeout = responseTimeout or 1
+    self.cacheTimeout = 1
+    self.cache = {}
+
+    local controlSocket, reason = socketConnect(address, port, self.responseTimeout)
+    if not controlSocket then
+        return nil, reason
+    end
+
+    self.controlSocket = controlSocket
+
+    self.receiveResponse = FTPReceiveResponse
+    self.sendCommand = FTPSendCommand
+    self.sendPassiveModeCommand = FTPSendPassiveModeCommand
+    self.beginNegotiation = FTPBeginNegotiation
+    self.endNegotiation = FTPEndNegotiation
+    self.receiveData = FTPReceiveData
+    self.sendData = FTPSendData
+    self.close = FTPClose
+
+    self.setCacheValue = FTPSetCacheValue
+    self.getCacheValue = FTPGetCacheValue
+
+    self.keepAlive = FTPKeepAlive
+    self.login = FTPLogin
+    self.setMode = FTPSetMode
+    self.getWorkingDirectory = FTPGetWorkingDirectory
+    self.changeWorkingDirectory = FTPChangeWorkingDirectory
+    self.getFileSize = FTPGetFileSize
+    self.resolvePath = FTPResolvePath
+    self.requestFilesInformation = FTPRequestFilesInformation
+    self.listDirectory = FTPListDirectory
+    self.getFileInfo = FTPGetFileInfo
+    self.fileExists = FTPFileExists
+    self.removeFile = FTPRemoveFile
+    self.makeDirectory = FTPMakeDirectory
+    self.renameFile = FTPRenameFile
+
+    self.readFile = FTPReadFile
+    self.readFileToMemory = FTPReadFileToMemory
+    self.readFileToFilesystem = FTPReadFileToFilesystem
+    self.writeFile = FTPWriteFile
+    self.writeFileFromMemory = FTPWriteFileFromMemory
+    self.writeFileFromFilesystem = FTPWriteFileFromFilesystem  
+
+    -- Receiving greeting
+    local response, reason = self:receiveResponse()
+    if not response then
+        self:close()
+        return nil, "unable to receive greeting: " .. reason
+    end
+
+    if response.status ~= 220 then
+        self:close()
+        return nil, "the server is not able to process client: " .. response.content
+    end
+
+    self.greeting = response.content
+
+    -- Requesting and parsing server features
+    local response, reason = self:sendCommand("FEAT")
+    if pizda(response) then
+        self:close()
+        return nil, "unable to receive server features: " .. (reason or response.content)
+    end
+
+    self.features = {}
+    for line in FTP.lines(response.content) do
+        local feature = line:match("^ (%w+)$")
+
+        if feature then
+            self.features[feature] = true
+        end
+    end
+
+    return self
+end
+
+----------------------------------------------------------------------------------------------------------------
+
+return FTP