Implement hello back in IPC protocol (#7334)

* Update VS Code config for Windows daemon debugging

* Update CL

* Implement hello back in IPC protocol

* Update CL

ChangeLog

@@ -11,9 +11,6 @@ Enhancements:
 - #7277 Change all errors that cause crash are FATAL
 - #7282 Improve error handling for thread jobs
 - #7284 Change session ID info log message to DEBUG2
-
-Tasks:
-
 - #7283 Update all workflows and fix broken macOS workflows
 - #7313 Fix CodeQL workflow: Failed to perl 404 Not Found
 - #7317 Bump sonar-scanner-cli to 5.0.1.3006
@@ -31,6 +28,7 @@ Tasks:
 - #7331 Script to install deps (Windows only for now)
 - #7332 Static link OpenSSL libs in CMake preset for Windows
 - #7333 Update VS Code config for Windows daemon debugging
+- #7334 Implement hello back in IPC protocol
 
 # 1.14.6
 
@@ -62,9 +60,6 @@ Enhancements:
 - #7193 Support for maintenance licenses in China
 - #7197 Special contributor mentions on the about screen
 - #7203 License registration for Business edition
-
-CI changes:
-
 - #7210 Update macos workflow to use macos-latest
 - #7213 Update azure pipelines to use macos-latest
 
@@ -86,9 +81,6 @@ Enhancements:
 - #7188 Synergy Basic\Pro accepts business licenses
 - #7166 Replace language notifications with warnings in logs
 - #7181 Fedora 36 support to CI system
-
-CI changes:
-
 - #7177 Create workflow for flatpak build support
 - #7148 Fix unstable build for Windows core
 - #7156 Change binary storage server
@@ -135,9 +127,6 @@ Enhancements:
 - #7068 Restart when settings changed
 - #7072 Run synergy as a pre-login agent
 - #7074 Restart when server settings changed
-
-CI changes:
-
 - #1043 Upload to S3 feature on all OS
 - #7098 Apple M1 runner
 - #7103 Fix core builds

src/lib/ipc/Ipc.cpp

@@ -19,6 +19,7 @@
 #include "ipc/Ipc.h"
 
 const char*                kIpcMsgHello        = "IHEL%1i";
+const char*                kIpcMsgHelloBack    = "IHEL";
 const char*                kIpcMsgLogLine      = "ILOG%s";
 const char*                kIpcMsgCommand      = "ICMD%s%1i";
 const char*                kIpcMsgShutdown     = "ISDN";

src/lib/ipc/Ipc.h

@@ -23,6 +23,7 @@
 
 enum EIpcMessage {
     kIpcHello,
+    kIpcHelloBack,
     kIpcLogLine,
     kIpcCommand,
     kIpcShutdown,
@@ -32,13 +33,17 @@ enum EIpcMessage {
 enum EIpcClientType {
     kIpcClientUnknown,
     kIpcClientGui,
-    kIpcClientNode,
+    kIpcClientNode
 };
 
 // handshake: node/gui -> daemon
 // $1 = type, the client identifies it's self as gui or node (synergyc/s).
 extern const char*        kIpcMsgHello;
 
+// handshake: daemon -> node/gui
+// the daemon responds to the handshake.
+extern const char*        kIpcMsgHelloBack;
+
 // log line: daemon -> gui
 // $1 = aggregate log lines collected from synergys/c or the daemon itself.
 extern const char*        kIpcMsgLogLine;

src/lib/ipc/IpcClientProxy.cpp

@@ -159,6 +159,10 @@ IpcClientProxy::send(const IpcMessage& message)
         ProtocolUtil::writef(&m_stream, kIpcMsgShutdown);
         break;
 
+    case kIpcHelloBack:
+        ProtocolUtil::writef(&m_stream, kIpcMsgHelloBack);
+        break;
+
     default:
         LOG((CLOG_ERR "ipc message not supported: %d", message.type()));
         break;

src/lib/ipc/IpcMessage.cpp

@@ -38,6 +38,15 @@ IpcHelloMessage::~IpcHelloMessage()
 {
 }
 
+IpcHelloBackMessage::IpcHelloBackMessage() :
+    IpcMessage(kIpcHelloBack)
+{
+}
+
+IpcHelloBackMessage::~IpcHelloBackMessage()
+{
+}
+
 IpcShutdownMessage::IpcShutdownMessage() :
 IpcMessage(kIpcShutdown)
 {

src/lib/ipc/IpcMessage.h

@@ -49,6 +49,12 @@ class IpcHelloMessage : public IpcMessage {
     EIpcClientType            m_clientType;
 };
 
+class IpcHelloBackMessage : public IpcMessage {
+public:
+    IpcHelloBackMessage();
+    virtual ~IpcHelloBackMessage();
+};
+
 class IpcShutdownMessage : public IpcMessage {
 public:
     IpcShutdownMessage();

src/lib/synergy/DaemonApp.cpp

@@ -21,6 +21,7 @@
 
 #include "synergy/DaemonApp.h"
 
+#include "ipc/Ipc.h"
 #include "synergy/App.h"
 #include "synergy/ArgParser.h"
 #include "synergy/ServerArgs.h"
@@ -37,6 +38,7 @@
 #include "base/EventQueue.h"
 #include "base/log_outputters.h"
 #include "base/Log.h"
+#include "synergy/protocol_types.h"
 
 #if SYSAPI_WIN32
 
@@ -145,6 +147,7 @@ DaemonApp::run(int argc, char** argv)
     try
     {
 #if SYSAPI_WIN32
+        // TODO: maybe we should only add this if not using /f?
         // sends debug messages to visual studio console window.
         log.insert(new MSWindowsDebugOutputter());
 #endif
@@ -164,11 +167,13 @@ DaemonApp::run(int argc, char** argv)
             }
 #if SYSAPI_WIN32
             else if (arg == "/install") {
+                LOG((CLOG_PRINT "installing windows daemon"));
                 uninstall = true;
                 arch.installDaemon();
                 return kExitSuccess;
             }
             else if (arg == "/uninstall") {
+                LOG((CLOG_PRINT "uninstalling windows daemon"));
                 arch.uninstallDaemon();
                 return kExitSuccess;
             }
@@ -182,14 +187,18 @@ DaemonApp::run(int argc, char** argv)
         }
 
         if (foreground) {
+            LOG((CLOG_PRINT "starting daemon in foreground"));
+
             // run process in foreground instead of daemonizing.
             // useful for debugging.
             mainLoop(false, foreground);
         }
         else {
 #if SYSAPI_WIN32
+            LOG((CLOG_PRINT "daemonizing windows service"));
             arch.daemonize("Synergy", winMainLoopStatic);
 #elif SYSAPI_UNIX
+            LOG((CLOG_PRINT "daemonizing unix service"));
             arch.daemonize("Synergy", unixMainLoopStatic);
 #endif
         }
@@ -399,6 +408,13 @@ DaemonApp::handleIpcMessage(const Event& e, void*)
 
             LOG((CLOG_DEBUG "ipc hello, type=%s", type.c_str()));
 
+            // TODO: implement hello back handling in s1 gui and node (server/client).
+            if (hm->clientType() == kIpcClientGui) {
+                LOG((CLOG_DEBUG "sending ipc hello back"));
+                IpcHelloBackMessage hbm;
+                m_ipcServer->send(hbm, hm->clientType());
+            }
+
 #if SYSAPI_WIN32
             String watchdogStatus = m_watchdog->isProcessActive() ? "active" : "idle";
             LOG((CLOG_INFO "service status: %s", watchdogStatus.c_str()));