Implement auto-update routine

src/main.rs

@@ -15,7 +15,7 @@
 // lazily from a `RwLock<String>` whenever any path is computed (config dir,
 // log dir, named-pipe namespace, …), so setting it before any of those
 // initializers fire is enough to redirect all hbb_common state under
-// `%APPDATA%\HelloAgent\` and the matching LocalService path. Identical
+// `%APPDATA%\hello-agent\` and the matching LocalService path. Identical
 // to the `read_custom_client` write path the upstream Flutter build uses
 // for OEM rebrands.
 
@@ -39,17 +39,28 @@ use cli::{Action, ParsedArgs};
 /// Product name used to namespace all on-disk state and the IPC pipe path.
 /// Written into `hbb_common::config::APP_NAME` at the top of `main` so
 /// every subsequent path computation (config dir, log dir, named pipe)
-/// targets `%APPDATA%\HelloAgent\` rather than the upstream default of
+/// targets `%APPDATA%\hello-agent\` rather than the upstream default of
 /// `%APPDATA%\RustDesk\`. Must be set before any code touches a path —
 /// `hbb_common` initializes path globals lazily on first read.
-pub const APP_NAME: &str = "HelloAgent";
+///
+/// Important: this value also drives upstream's installer lookup paths.
+/// `librustdesk::platform::get_install_info` computes the expected install
+/// dir as `%ProgramFiles%\<APP_NAME>` and the expected exe filename as
+/// `<APP_NAME>.exe`. Keeping `APP_NAME` aligned with the lowercase-hyphenated
+/// install path (`%ProgramFiles%\hello-agent\hello-agent.exe`) is what
+/// makes `--update` (which delegates to `librustdesk::platform::update_me`)
+/// find the binary it needs to replace, kill the right process by image
+/// name, and rename the staged exe to `hello-agent.exe` after the copy.
+/// Renaming this constant without renaming the install dir / exe will
+/// silently break self-update.
+pub const APP_NAME: &str = "hello-agent";
 
 /// Set up logging. We delegate to `hbb_common::init_log`, which:
 ///   * In **debug** builds: installs `env_logger` writing to stderr.
 ///   * In **release** builds: installs `flexi_logger` writing to a rolling
 ///     file under `<config_dir>/log/<mode>/` — the SYSTEM service log ends
-///     up at `%SystemRoot%\ServiceProfiles\LocalService\AppData\Roaming\HelloAgent\log\<mode>\`
-///     and the user-mode log at `%APPDATA%\HelloAgent\log\<mode>\`.
+///     up at `%SystemRoot%\ServiceProfiles\LocalService\AppData\Roaming\hello-agent\log\<mode>\`
+///     and the user-mode log at `%APPDATA%\hello-agent\log\<mode>\`.
 ///
 /// The `mode` label segregates per-run-mode log files so service worker
 /// chatter doesn't tangle with --install diagnostics. `init_log` is
@@ -65,7 +76,7 @@ fn main() {
     // we'd never recover.
     *hbb_common::config::APP_NAME.write().unwrap() = APP_NAME.to_owned();
     // Identify ourselves to the rustdesk-server's /api/sysinfo endpoint
-    // so the admin Devices page can show "HelloAgent 0.1.0" instead of
+    // so the admin Devices page can show "hello-agent 0.1.0" instead of
     // the embedded rustdesk core version. These RwLocks are read once
     // per sysinfo upload by hbbs_http::sync; setting them here (before
     // start_server) ensures the very first upload carries the identity.
@@ -90,10 +101,40 @@ fn main() {
         Action::Service => "service",
         Action::Server => "server",
         Action::Cm => "cm",
+        Action::Update => "update",
         Action::ConfigOnly | Action::None => "hello-agent",
     };
     init_logging(mode);
 
+    // --update is the self-replacement re-entry: the running service's
+    // updater downloads a new hello-agent.exe to %TEMP%, verifies its
+    // SHA256, then launches `<temp>\hello-agent.exe --update` as an
+    // elevated child. We are that child — `current_exe()` is the staged
+    // new binary, and our only job is to copy ourselves over the
+    // installed location and restart the service. Do it before the
+    // config-import dance below so a corrupt-on-disk config can't block
+    // an update from going through.
+    if parsed.action == Action::Update {
+        #[cfg(target_os = "windows")]
+        {
+            match librustdesk::platform::update_me(false) {
+                Ok(()) => {
+                    log::info!("hello-agent: --update completed");
+                }
+                Err(e) => {
+                    log::error!("hello-agent: --update failed: {e:#}");
+                    std::process::exit(1);
+                }
+            }
+        }
+        #[cfg(not(target_os = "windows"))]
+        {
+            eprintln!("hello-agent: --update is Windows-only.");
+            std::process::exit(1);
+        }
+        return;
+    }
+
     // --config is allowed to combine with --install (one-line MDM deploy)
     // but on its own is a separate operation. Apply it first so --install
     // sees the populated config.
@@ -108,7 +149,14 @@ fn main() {
     // (or a prior install) already set custom-rendezvous-server, this is a
     // no-op. Without this, a bare `hello-agent.exe --install` would land
     // at an unconfigured agent that can't reach any server.
-    config_import::apply_defaults_if_empty();
+    //
+    // Skipped for `--uninstall`: an uninstall flow has no business mutating
+    // the calling user's config, and otherwise we'd write defaults into
+    // %APPDATA% right before tearing the agent down. (`--update` is
+    // dispatched in the early-return block above and never reaches here.)
+    if parsed.action != Action::Uninstall {
+        config_import::apply_defaults_if_empty();
+    }
 
     match parsed.action {
         Action::Install => {
@@ -172,6 +220,11 @@ fn main() {
             // can watch logs. Production deployments use --install + --service.
             run_server();
         }
+        Action::Update => {
+            // Handled in the early-return block above (before config-import).
+            // The match has to cover this variant for exhaustiveness.
+            unreachable!("Action::Update is dispatched before this match");
+        }
     }
 }