ksud: use bind mount to serve module webui

userspace/ksud/src/cli.rs

@@ -192,6 +192,15 @@ enum Module {
         #[arg(default_value = "8080")]
         port: u16,
     },
+    /// Link modules for manager
+    LinkManager {
+        /// module id
+        mid: String,
+        /// Manager's pid
+        pid: i32,
+        /// Manager's package name
+        pkg: String,
+    },
 }
 
 #[derive(clap::Subcommand, Debug)]
@@ -273,6 +282,9 @@ pub fn run() -> Result<()> {
                 Module::List => module::list_modules(),
                 Module::Shrink => module::shrink_ksu_images(),
                 Module::Serve { id, port } => server::serve_module(&id, port),
+                Module::LinkManager { mid, pid, pkg } => {
+                    module::link_module_for_manager(pid, &pkg, &mid)
+                }
             }
         }
         Commands::Install => event::install(),

userspace/ksud/src/module.rs

@@ -703,3 +703,24 @@ pub fn shrink_ksu_images() -> Result<()> {
     }
     Ok(())
 }
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+pub fn link_module_for_manager(pid: i32, pkg: &str, mid: &str) -> Result<()> {
+    // switch to manager's mnt ns
+    utils::switch_mnt_ns(pid)?;
+    let target = PathBuf::from("/data/data").join(pkg).join("webroot");
+
+    // umount previous mount
+    let _ = mount::umount_dir(&target);
+
+    let src = PathBuf::from(defs::MODULE_DIR)
+        .join(mid)
+        .join(defs::MODULE_WEB_DIR);
+    mount::bind_mount(src, &target)?;
+    Ok(())
+}
+
+#[cfg(not(any(target_os = "linux", target_os = "android")))]
+pub fn link_module_for_manager(_pid: i32, _pkg: &str, _mid: &str) -> Result<()> {
+    unimplemented!()
+}

userspace/ksud/src/mount.rs

@@ -174,7 +174,7 @@ pub fn mount_tmpfs(dest: impl AsRef<Path>) -> Result<()> {
 }
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
-fn bind_mount(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<()> {
+pub fn bind_mount(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<()> {
     info!(
         "bind mount {} -> {}",
         from.as_ref().display(),