macOS: Use local socket to communicate with finder extension

#6343

shell_integration/MacOSX/OwnCloud.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

shell_integration/MacOSX/OwnCloudFinderSync/FinderSyncExt/FinderSync.h

@@ -15,15 +15,19 @@
 
 #import <Cocoa/Cocoa.h>
 #import <FinderSync/FinderSync.h>
-#import "SyncClientProxy.h"
 
-@interface FinderSync : FIFinderSync <SyncClientProxyDelegate>
-{
-	SyncClientProxy *_syncClientProxy;
-	NSMutableSet *_registeredDirectories;
-	NSString *_shareMenuTitle;
-	NSMutableDictionary *_strings;
-	NSMutableArray *_menuItems;
+#import "FinderSyncExt-Swift.h"
+#import "SyncClient.h"
+
+@interface FinderSync : FIFinderSync <SyncClientDelegate> {
+    NSMutableSet *_registeredDirectories;
+    NSString *_shareMenuTitle;
+    NSMutableDictionary *_strings;
+    NSMutableArray *_menuItems;
+    NSCondition *_menuIsComplete;
 }
 
+@property LineProcessorV1 *v1LineProcessor;
+@property LocalSocketClient *localSocketClient;
+
 @end

shell_integration/MacOSX/OwnCloudFinderSync/FinderSyncExt/FinderSyncExt-Bridging-Header.h

@@ -0,0 +1,5 @@
+//
+//  Use this file to import your target's public headers that you would like to expose to Swift.
+//
+
+#import "SyncClient.h"

shell_integration/MacOSX/OwnCloudFinderSync/FinderSyncExt/LineProcessorV1.swift

@@ -0,0 +1,67 @@
+//
+//  LineProcessorV1.swift
+//  FinderSyncExt
+//
+//  Created by Erik Verbruggen <erik@verbruggen.consulting> on 06-11-21.
+//
+
+import Foundation
+import OSLog
+
+class LineProcessorV1: NSObject, LineProcessor {
+    let delegate: SyncClientDelegate
+
+    @objc init(withDelegate delegate: SyncClientDelegate) {
+        self.delegate = delegate
+    }
+
+    private func log(_ str: String, type logType: OSLogType) {
+        // We cannot use OSLog's Logger class, because a lot of methods are only available in macOS 11.0 or higher.
+        os_log("%@", type: logType, str)
+    }
+
+    /// Processes a line, where the trailing \n has already been stripped
+    func process(line: String) {
+
+        self.log("Processing line '\(line)'", type: .debug)
+        let chunks = line.components(separatedBy: ":")
+        let command = chunks[0]
+
+        switch command {
+        case "STATUS":
+            let result = chunks[1]
+            let path = chunks.suffix(from: 2).joined(separator: ":")
+            DispatchQueue.main.async { self.delegate.setResultForPath(path, result: result) }
+        case "UPDATE_VIEW":
+            let path = chunks[1]
+            DispatchQueue.main.async { self.delegate.reFetchFileNameCache(forPath: path) }
+        case "REGISTER_PATH":
+            let path = chunks[1]
+            DispatchQueue.main.async { self.delegate.registerPath(path) }
+        case "UNREGISTER_PATH":
+            let path = chunks[1]
+            DispatchQueue.main.async { self.delegate.unregisterPath(path) }
+        case "GET_STRINGS":
+            // BEGIN and END messages, do nothing.
+            break
+        case "STRING":
+            DispatchQueue.main.async { self.delegate.setString(chunks[1], value: chunks[2]) }
+        case "GET_MENU_ITEMS":
+            if chunks[1] == "BEGIN" {
+                DispatchQueue.main.async { self.delegate.resetMenuItems() }
+            } else {
+                // Do NOT run this on the main queue! It might be blocked waiting for the menu to be completed.
+                delegate.menuHasCompleted()
+            }
+        case "MENU_ITEM":
+            let item = [
+                "command" : chunks[1],
+                "flags"   : chunks[2],
+                "text"    : chunks[3]
+            ]
+            DispatchQueue.main.async { self.delegate.addMenuItem(item) }
+        default:
+            self.log("Unknown command '\(command)'", type: .error)
+        }
+    }
+}

shell_integration/MacOSX/OwnCloudFinderSync/FinderSyncExt/LocalSocketClient.swift

@@ -0,0 +1,274 @@
+//
+//  LocalSocketClient.swift
+//  FinderSyncExt
+//
+//  Created by Erik Verbruggen <erik@verbruggen.consulting> on 04-11-21.
+//
+
+import Foundation
+import OSLog
+
+/// Process lines from the `LocalSocketClient`.
+@objc protocol LineProcessor {
+    func process(line: String);
+}
+
+/// Class handling the (asynchronous) communication with a server over a local (UNIX) socket.
+///
+/// The implementation uses a `DispatchQueue` and `DispatchSource`s to handle asynchronous communication and thread
+/// safety. All public/@objc function can be called from any thread/queue. The delegate that handles the
+/// line-decoding is **not invoked on the UI thread**, but the (random) thread associated with the `DispatchQueue`!
+/// If any UI work needs to be done, the class implementing the `LineProcessor` protocol should dispatch this work
+/// on the main queue (so the UI thread) itself!
+///
+/// Other than the `init(withSocketPath:, lineProcessor)` and the `start()` method, all work is done "on the dispatch
+/// queue". The `localSocketQueue` is a serial dispatch queue (so a maximum of 1, and only 1, task is run at any
+/// moment), which guarantees safe access to instance variables. Both `askOnSocket(_:, query:)` and
+/// `askForIcon(_:, isDirectory:)` will internally dispatch the work on the `DispatchQueue`.
+///
+/// Sending and receiving data to and from the socket, is handled by two `DispatchSource`s. These will run an event
+/// handler when data can be read from resp. written to the socket. These handlers will also be run on the
+/// `DispatchQueue`.
+class LocalSocketClient: NSObject {
+    let socketPath: String
+    let lineProcessor: LineProcessor
+
+    private var sock: Int32?
+    private var localSocketQueue = DispatchQueue.init(label: "localSocketQueue")
+    private var readSource: DispatchSourceRead?
+    private var writeSource: DispatchSourceWrite?
+    private var inBuffer = [UInt8]()
+    private var outBuffer = [UInt8]()
+
+    @objc var isConnected: Bool {
+        get {
+            sock != nil
+        }
+    }
+
+    @objc init(withSocketPath socketPath: String, lineProcessor: LineProcessor) {
+        self.socketPath = socketPath
+        self.lineProcessor = lineProcessor
+
+        super.init()
+
+        self.inBuffer.reserveCapacity(1000)
+    }
+
+    private func log(_ str: String, type logType: OSLogType) {
+        if #available(macOSApplicationExtension 11.0, *) {
+            // NOTE: when support for 10.* is dropped, make an instance variable instead of instantiating the `Logger`
+            //       object every time.
+            Logger().log(level: logType, "\(str, privacy: .public)")
+        } else {
+            os_log("%@", type: logType, str)
+        }
+    }
+
+    @objc func start() {
+        var sa_un = sockaddr_un()
+
+        let socketPathByteCount = socketPath.utf8.count + 1; // add 1 for the NUL terminator char
+        let maxByteCount = MemoryLayout.size(ofValue: sa_un.sun_path)
+        guard socketPathByteCount < maxByteCount else {
+            log("Socket path '\(socketPath)' is too long: \(socketPathByteCount) is longer than \(maxByteCount)",
+                type: .error)
+            return
+        }
+
+        log("Opening local socket...", type: .debug)
+
+        self.sock = socket(AF_LOCAL, SOCK_STREAM, 0)
+        guard self.sock != -1 else {
+            self.log("Cannot open socket: \(self.strErr())", type: .error)
+            self.restart()
+            return
+        }
+
+        log("Local socket openned, now connecting to '\(self.socketPath)' ...", type: .debug)
+
+        sa_un.sun_family = UInt8(AF_LOCAL & 0xff)
+
+        let pathBytes = socketPath.utf8 + [0]
+        pathBytes.withUnsafeBytes { srcBuffer in
+            withUnsafeMutableBytes(of: &sa_un.sun_path) { dstPtr in
+                dstPtr.copyMemory(from: srcBuffer)
+            }
+        }
+
+        let connStatus = withUnsafePointer(to: &sa_un) { sa_unPtr in
+            // We are now allowed to mess with the raw pointer to `sa_un`, and cast it to a `sockaddr` pointer.
+            // This is basically a barrier before and after this closure, so that all writes have been done before by
+            // the compiler, and that subsequent reads do not read old values (because Swift can't see if `connect`
+            // messes with the memory for which it receives a raw pointer).
+            sa_unPtr.withMemoryRebound(to: sockaddr.self, capacity: 1) { saPtr in
+                connect(self.sock!, saPtr, socklen_t(MemoryLayout<sockaddr_un>.size))
+            }
+        }
+
+        guard connStatus != -1 else {
+            self.log("Cannot connect to '\(self.socketPath): \(self.strErr())", type: .error)
+            self.restart()
+            return
+        }
+
+        let flags = fcntl(self.sock!, F_GETFL, 0)
+        guard -1 != fcntl(self.sock!, F_SETFL, flags | O_NONBLOCK) else {
+            self.log("Cannot set socket to non-blocking mode: \(self.strErr())", type: .error)
+            self.restart()
+            return
+        }
+
+        self.readSource = DispatchSource.makeReadSource(fileDescriptor: self.sock!, queue: self.localSocketQueue)
+        self.readSource!.setEventHandler { self.readFromSocket() }
+        self.readSource!.setCancelHandler {
+            self.readSource = nil
+            self.closeConnection()
+        }
+        self.readSource!.resume()
+
+        self.writeSource = DispatchSource.makeWriteSource(fileDescriptor: self.sock!, queue: self.localSocketQueue)
+        self.writeSource!.setEventHandler { self.writeToSocket() }
+        self.writeSource!.setCancelHandler {
+            self.writeSource = nil
+            self.closeConnection()
+        }
+        // The writeSource dispatch queue starts suspended; we will resume it when we have data to send (and suspend it
+        // again when our send buffer is empty).
+
+        self.log("We have a connection! Starting I/O channel...", type: .info)
+
+        self.askOnSocket("", query: "GET_STRINGS")
+    }
+
+    private func restart() {
+        self.closeConnection()
+
+        DispatchQueue.main.async {
+            Timer.scheduledTimer(withTimeInterval: 5, repeats: false, block: { _ in
+                self.start()
+            });
+        }
+    }
+
+    private func closeConnection() {
+        self.readSource?.cancel()
+        self.writeSource?.cancel()
+        self.readSource = nil
+        self.writeSource = nil
+        self.inBuffer.removeAll()
+        self.outBuffer.removeAll()
+        if let sock = self.sock {
+            close(sock)
+            self.sock = nil
+        }
+    }
+
+    private func strErr() -> String {
+        let err = errno // copy error code now, in case something else happens
+        return String(utf8String: strerror(err)) ?? "Unknown error code  (\(err))"
+    }
+
+    @objc func askOnSocket(_ path: String, query verb: String) {
+        let line = "\(verb):\(path)\n"
+        self.localSocketQueue.async {
+            guard self.isConnected else {
+                // socket was closed while work was still scheduled on the queue
+                return
+            }
+
+            self.log("Sending line '\(line)", type: .debug)
+
+            let writeSourceIsSuspended = self.outBuffer.isEmpty
+            let uint8Data: [UInt8] = line.utf8 + []
+            self.outBuffer.append(contentsOf: uint8Data)
+
+            // Weird stuff happens when you call resume when the DispatchSource is already resumed, so: if we did NOT
+            // have any data in our output buffer before queueing more data, it must be suspended.
+            if writeSourceIsSuspended {
+                self.writeSource?.resume() // now we will get notified when we can write to the socket.
+            }
+        }
+    }
+
+    private func writeToSocket() {
+        guard self.isConnected else {
+            // socket was closed while work was still scheduled on the queue
+            return
+        }
+
+        guard !self.outBuffer.isEmpty else {
+            // the buffer is empty, suspend you-can-write-data notifications
+            self.writeSource!.suspend()
+            return
+        }
+
+        let totalAmountOfBytes = self.outBuffer.count
+        let bytesWritten = self.outBuffer.withUnsafeBytes { ptr in
+            write(self.sock!, ptr.baseAddress, totalAmountOfBytes)
+        }
+        if bytesWritten == -1 {
+            if errno == EAGAIN {
+                // no space free in the buffer on the OS side, we're done
+            } else {
+                self.log("Error writing to local socket: \(self.strErr())", type: .error)
+                self.restart()
+            }
+        } else if bytesWritten > 0 {
+            self.outBuffer.removeFirst(bytesWritten)
+            if self.outBuffer.isEmpty {
+                // the buffer is empty, suspend you-can-write-data notifications
+                self.writeSource!.suspend()
+            }
+        }
+    }
+
+    @objc func askForIcon(_ path: String, isDirectory: Bool) {
+        let verb = isDirectory ? "RETRIEVE_FOLDER_STATUS" : "RETRIEVE_FILE_STATUS"
+        self.askOnSocket(path, query: verb)
+    }
+
+    private func readFromSocket() {
+        guard self.isConnected else {
+            // socket was closed while work was still scheduled on the queue
+            return
+        }
+
+        let bufferLength = self.inBuffer.capacity / 2
+        var buffer = [UInt8].init(repeating: 0, count: bufferLength)
+
+        while true {
+            let bytesRead = buffer.withUnsafeMutableBytes { ptr in
+                read(self.sock!, ptr.baseAddress, bufferLength)
+            }
+            if bytesRead == -1 {
+                if errno == EAGAIN {
+                    return // no bytes available, and no error, so we're done
+                } else {
+                    self.log("Error reading from local socket: \(self.strErr())", type: .error)
+                    self.closeConnection()
+                    return // we've closed the connection, we're done
+                }
+            } else {
+                self.inBuffer.append(contentsOf: buffer[0..<bytesRead])
+                self.processInBuffer()
+                // see if there is more to read: restart the loop
+            }
+        }
+    }
+
+    private func processInBuffer() {
+        let separator: UInt8 = 0xa // byte value for '\n'
+        while true {
+            if let pos = self.inBuffer.firstIndex(of: separator) {
+                self.inBuffer[pos] = 0 // add NUL terminator
+                let newLine = String(cString: &self.inBuffer)
+                self.inBuffer.removeFirst(pos + 1) // remove the line from the buffer, including the NUL terminator
+                self.lineProcessor.process(line: newLine)
+            } else {
+                // no separator, we're done
+                return;
+            }
+        }
+    }
+}