fruity: Embed idund for embedded assets

Idun now always goes through idund on Windows and Linux, so ship the
daemon inside the library when assets are embedded, extracting it to a
temporary file before starting the device monitor. With installed
assets Idun installs idund next to the library and resolves it from
there. A daemon that fails to start is reported on stderr and leaves
Apple devices unavailable instead of failing the whole backend.

Author: oleavr

meson.build

@@ -727,11 +727,18 @@ openssl_dep = dependency('openssl',
 )
 
 idun_libs = []
+have_idund_blob = false
 if have_fruity_backend
   idun_dep = dependency('idun-1.0', default_options: ['default_library=static'])
   backend_reqs_private += 'idun-1.0'
   if idun_dep.type_name() == 'internal'
-    idun_libs += subproject('idun').get_variable('idun')
+    idun_sp = subproject('idun')
+    idun_libs += idun_sp.get_variable('idun')
+    if assets_mode == 'embedded' and idun_sp.get_variable('build_daemon')
+      idund_raw = idun_sp.get_variable('idund')
+      have_idund_blob = true
+      vala_flags += '--define=HAVE_IDUND_BLOB'
+    endif
   endif
   idun_vapidir = idun_dep.get_variable('vapidir', default_value: '')
   if idun_vapidir != ''

src/fruity/fruity-host-session.vala

@@ -8,6 +8,16 @@ namespace Frida {
 			new Gee.HashMap<Idun.Device, FruityHostSessionProvider> ();
 
 		private Cancellable io_cancellable = new Cancellable ();
+#if HAVE_IDUND_BLOB
+		private TemporaryDirectory daemon_dir = new TemporaryDirectory ();
+		private TemporaryFile? daemon_file;
+
+#if WINDOWS
+		private const string DAEMON_FILENAME = "idund.exe";
+#else
+		private const string DAEMON_FILENAME = "idund";
+#endif
+#endif
 
 		construct {
 			device_monitor.device_attached.connect (on_device_attached);
@@ -18,9 +28,30 @@ namespace Frida {
 #if !MACOS
 			migrate_pairing_store ();
 #endif
-			yield device_monitor.start (cancellable);
+			try {
+#if HAVE_IDUND_BLOB
+				device_monitor.daemon_path = extract_daemon ();
+#endif
+				yield device_monitor.start (cancellable);
+			} catch (Efni.Error e) {
+				printerr ("Unable to start idund: %s\n", e.message);
+			}
 		}
 
+#if HAVE_IDUND_BLOB
+		private string extract_daemon () throws Efni.Error {
+			var blob = Frida.Data.Idund.get_idund_blob ();
+			try {
+				daemon_file = new TemporaryFile.from_stream (DAEMON_FILENAME, new MemoryInputStream.from_data (blob.data, null),
+					daemon_dir);
+			} catch (Error e) {
+				throw new Efni.Error.PERMISSION_DENIED ("%s", e.message);
+			}
+			FileUtils.chmod (daemon_file.path, 0700);
+			return daemon_file.path;
+		}
+#endif
+
 #if !MACOS
 		private static void migrate_pairing_store () {
 			string config_dir = Environment.get_user_config_dir ();

src/fruity/idund.resources

@@ -0,0 +1,2 @@
+[resource-compiler]
+namespace = Frida.Data.Idund

src/meson.build

@@ -592,6 +592,33 @@ if have_fruity_backend
     'fruity' / 'injector.vala',
   ]
   backend_deps += idun_dep
+
+  if have_idund_blob
+    idund = custom_target('frida-idund',
+      input: idund_raw,
+      output: 'idund' + exe_suffix,
+      command: post_process + ['executable', 're.frida.Idund'],
+    )
+    idund_data = custom_target('frida-data-idund',
+      input: [
+        'fruity' / 'idund.resources',
+        idund,
+      ],
+      output: [
+        'frida-data-idund.vapi',
+        'frida-data-idund.h',
+        'frida-data-idund.c',
+        'frida-data-idund-blob' + resource_blob_extension,
+      ],
+      command: [
+        resource_compiler_cmd_array,
+        '-c', '@INPUT0@',
+        '-o', meson.current_build_dir() / 'frida-data-idund',
+        '@INPUT1@',
+      ],
+    )
+    backend_sources += [idund_data]
+  endif
 endif
 
 if have_droidy_backend