Implement auto-update routine

src/cli.rs

@@ -31,6 +31,13 @@ pub enum Action {
     /// — every `Data::FS(...)` frame the server sends is executed here, in
     /// the user's security context.
     Cm,
+    /// `--update`. Self-replacement entry point launched as an elevated child
+    /// by the running service's updater (see `librustdesk::updater`) after it
+    /// has downloaded and SHA256-verified a new hello-agent.exe from the
+    /// Gitea releases page. `current_exe()` here points at the staged new
+    /// binary in `%TEMP%`; it copies itself over the installed location and
+    /// restarts the service via `librustdesk::platform::update_me`.
+    Update,
 }
 
 #[derive(Debug)]
@@ -47,6 +54,7 @@ impl ParsedArgs {
         let mut service = false;
         let mut server = false;
         let mut cm = false;
+        let mut update = false;
         let mut config_blob: Option<String> = None;
 
         let mut i = 0;
@@ -56,6 +64,7 @@ impl ParsedArgs {
                 "--uninstall" => uninstall = true,
                 "--service" => service = true,
                 "--server" => server = true,
+                "--update" => update = true,
                 // Connection-manager popup mode. Treat `--cm-no-ui` (the
                 // Linux-headless variant librustdesk also tries) as a
                 // synonym; either way we run cm_popup.
@@ -81,14 +90,21 @@ impl ParsedArgs {
         }
 
         // Mutual-exclusion rules. --install + --config is the MDM one-liner;
-        // everything else is one-action-at-a-time.
-        let exclusive = [uninstall, service, server, cm].iter().filter(|x| **x).count();
+        // everything else is one-action-at-a-time. --update is launched by
+        // the updater as a standalone elevated child, never combined.
+        let exclusive = [uninstall, service, server, cm, update]
+            .iter()
+            .filter(|x| **x)
+            .count();
         if exclusive > 1 {
-            bail!("--uninstall, --service, --server, --cm are mutually exclusive");
+            bail!("--uninstall, --service, --server, --cm, --update are mutually exclusive");
         }
         if uninstall && (install || config_blob.is_some()) {
             bail!("--uninstall cannot be combined with other flags");
         }
+        if update && (install || config_blob.is_some()) {
+            bail!("--update cannot be combined with other flags");
+        }
 
         let action = if uninstall {
             Action::Uninstall
@@ -100,6 +116,8 @@ impl ParsedArgs {
             Action::Server
         } else if cm {
             Action::Cm
+        } else if update {
+            Action::Update
         } else if config_blob.is_some() {
             Action::ConfigOnly
         } else {
@@ -131,6 +149,10 @@ OPTIONS:
     --service              SCM entry point. Do not invoke manually.
     --server               Worker mode (launched by the service shell into
                            the active console session).
+    --update               Self-replacement entry point. Launched by the
+                           running service's updater after downloading and
+                           SHA256-verifying a new release from Gitea. Do
+                           not invoke manually.
     -h, --help             Show this help.
     -V, --version          Show version.
 
@@ -191,4 +213,24 @@ mod tests {
     fn unknown_arg() {
         assert!(parse(&["--no-such-flag"]).is_err());
     }
+
+    #[test]
+    fn update_alone() {
+        assert_eq!(parse(&["--update"]).unwrap().action, Action::Update);
+    }
+
+    #[test]
+    fn update_install_conflict() {
+        assert!(parse(&["--update", "--install"]).is_err());
+    }
+
+    #[test]
+    fn update_service_conflict() {
+        assert!(parse(&["--update", "--service"]).is_err());
+    }
+
+    #[test]
+    fn update_config_conflict() {
+        assert!(parse(&["--update", "--config", "BLOB"]).is_err());
+    }
 }