feat(plugin): add exec_cmd helper for executing command in host

Signed-off-by: Tw <wei.tan@intel.com>
Signed-off-by: Tw <tw19881113@gmail.com>

zellij-server/src/tab.rs

@@ -325,10 +325,15 @@ impl Tab {
             if let Some(Run::Plugin(Some(plugin))) = &layout.run {
                 let (pid_tx, pid_rx) = channel();
                 self.senders
-                    .send_to_plugin(PluginInstruction::Load(pid_tx, plugin.clone(), tab_index))
+                    .send_to_plugin(PluginInstruction::Load(
+                        pid_tx,
+                        plugin.path.clone(),
+                        tab_index,
+                        plugin._allow_exec_host_cmd,
+                    ))
                     .unwrap();
                 let pid = pid_rx.recv().unwrap();
-                let title = String::from(plugin.as_path().as_os_str().to_string_lossy());
+                let title = String::from(plugin.path.as_path().as_os_str().to_string_lossy());
                 let mut new_plugin = PluginPane::new(
                     pid,
                     *position_and_size,

zellij-server/src/wasm_vm.rs

@@ -1,4 +1,4 @@
-use log::info;
+use log::{info, warn};
 use std::collections::{HashMap, HashSet};
 use std::fs;
 use std::path::PathBuf;
@@ -28,7 +28,7 @@ use zellij_utils::{input::command::TerminalAction, serde, zellij_tile};
 
 #[derive(Clone, Debug)]
 pub(crate) enum PluginInstruction {
-    Load(Sender<u32>, PathBuf, usize), // tx_pid, path_of_plugin , tab_index
+    Load(Sender<u32>, PathBuf, usize, bool), // tx_pid, path_of_plugin , tab_index, allow_exec_host_cmd
     Update(Option<u32>, Event),              // Focused plugin / broadcast, event data
     Render(Sender<String>, u32, usize, usize), // String buffer, plugin id, rows, cols
     Unload(u32),
@@ -54,6 +54,8 @@ pub(crate) struct PluginEnv {
     pub senders: ThreadSenders,
     pub wasi_env: WasiEnv,
     pub subscriptions: Arc<Mutex<HashSet<EventType>>>,
+    // FIXME: Once permission system is ready, this could be removed
+    pub _allow_exec_host_cmd: bool,
 }
 
 // Thread main --------------------------------------------------------------------------------------------------------
@@ -65,7 +67,7 @@ pub(crate) fn wasm_thread_main(bus: Bus<PluginInstruction>, store: Store, data_d
         let (event, mut err_ctx) = bus.recv().expect("failed to receive event on channel");
         err_ctx.add_call(ContextType::Plugin((&event).into()));
         match event {
-            PluginInstruction::Load(pid_tx, path, tab_index) => {
+            PluginInstruction::Load(pid_tx, path, tab_index, _allow_exec_host_cmd) => {
                 let plugin_dir = data_dir.join("plugins/");
                 let wasm_bytes = fs::read(&path)
                     .or_else(|_| fs::read(&path.with_extension("wasm")))
@@ -99,12 +101,17 @@ pub(crate) fn wasm_thread_main(bus: Bus<PluginInstruction>, store: Store, data_d
 
                 let wasi = wasi_env.import_object(&module).unwrap();
 
+                if _allow_exec_host_cmd {
+                    info!("Plugin({:?}) is able to run any host command, this may lead to some security issues!", path);
+                }
+
                 let plugin_env = PluginEnv {
                     plugin_id,
                     tab_index,
                     senders: bus.senders.clone(),
                     wasi_env,
                     subscriptions: Arc::new(Mutex::new(HashSet::new())),
+                    _allow_exec_host_cmd,
                 };
 
                 let zellij = zellij_exports(&store, &plugin_env);
@@ -174,6 +181,7 @@ pub(crate) fn zellij_exports(store: &Store, plugin_env: &PluginEnv) -> ImportObj
         host_get_plugin_ids,
         host_open_file,
         host_set_timeout,
+        host_exec_cmd,
     }
 }
 
@@ -248,6 +256,24 @@ fn host_set_timeout(plugin_env: &PluginEnv, secs: f64) {
     });
 }
 
+fn host_exec_cmd(plugin_env: &PluginEnv) {
+    let mut cmdline: Vec<String> = wasi_read_object(&plugin_env.wasi_env);
+    let command = cmdline.remove(0);
+
+    // Bail out if we're forbidden to run command
+    if !plugin_env._allow_exec_host_cmd {
+        warn!("This plugin isn't allow to run command in host side, skip running this command: '{cmd} {args}'.",
+        	cmd = command, args = cmdline.join(" "));
+        return;
+    }
+
+    // Here, we don't wait the command to finish
+    process::Command::new(command)
+        .args(cmdline)
+        .spawn()
+        .unwrap();
+}
+
 // Helper Functions ---------------------------------------------------------------------------------------------------
 
 pub fn wasi_read_string(wasi_env: &WasiEnv) -> String {

zellij-tile/src/shim.rs

@@ -37,6 +37,10 @@ pub fn open_file(path: &Path) {
 pub fn set_timeout(secs: f64) {
     unsafe { host_set_timeout(secs) };
 }
+pub fn exec_cmd(cmd: &[&str]) {
+    object_to_stdout(&cmd);
+    unsafe { host_exec_cmd() };
+}
 
 // Internal Functions
 
@@ -60,4 +64,5 @@ extern "C" {
     fn host_get_plugin_ids();
     fn host_open_file();
     fn host_set_timeout(secs: f64);
+    fn host_exec_cmd();
 }

zellij-utils/assets/layouts/default.yaml

@@ -7,7 +7,8 @@ template:
       split_size:
         Fixed: 1
       run:
-        plugin: tab-bar
+        plugin:
+          path: tab-bar
     - direction: Vertical
       body: true
     - direction: Vertical
@@ -15,6 +16,7 @@ template:
       split_size:
         Fixed: 2
       run:
-        plugin: status-bar
+        plugin:
+          path: status-bar
 tabs:
   - direction: Vertical

zellij-utils/assets/layouts/disable-status-bar.yaml

@@ -7,6 +7,7 @@ template:
       split_size:
         Fixed: 1
       run:
-        plugin: tab-bar
+        plugin:
+          path: tab-bar
     - direction: Vertical
       body: true

zellij-utils/assets/layouts/strider.yaml

@@ -7,7 +7,8 @@ template:
       split_size:
         Fixed: 1
       run:
-        plugin: tab-bar
+        plugin:
+          path: tab-bar
     - direction: Vertical
       body: true
     - direction: Vertical
@@ -15,7 +16,8 @@ template:
       split_size:
         Fixed: 2
       run:
-        plugin: status-bar
+        plugin:
+          path: status-bar
 tabs:
   - direction: Vertical
     parts:
@@ -23,5 +25,6 @@ tabs:
         split_size:
           Percent: 20
         run:
-          plugin: strider
+          plugin:
+            path: strider
       - direction: Horizontal

zellij-utils/src/input/layout.rs

@@ -53,11 +53,19 @@ pub enum SplitSize {
 #[serde(crate = "self::serde")]
 pub enum Run {
     #[serde(rename = "plugin")]
-    Plugin(Option<PathBuf>),
+    Plugin(Option<RunPlugin>),
     #[serde(rename = "command")]
     Command(RunCommand),
 }
 
+#[derive(Debug, Default, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct RunPlugin {
+    pub path: PathBuf,
+    #[serde(default)]
+    pub _allow_exec_host_cmd: bool,
+}
+
 // The layout struct ultimately used to build the layouts.
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
 #[serde(crate = "self::serde")]

zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-default-plugins.yaml

@@ -6,14 +6,16 @@ template:
       split_size:
         Fixed: 1
       run:
-        plugin: tab-bar
+        plugin:
+          path: tab-bar
     - direction: Horizontal
       body: true
     - direction: Vertical
       split_size:
         Fixed: 2
       run:
-        plugin: status-bar
+        plugin:
+          path: status-bar
 
 tabs:
   - direction: Vertical

zellij-utils/src/input/unit/layout_test.rs

@@ -45,7 +45,10 @@ fn default_layout_merged_correctly() {
                 borderless: true,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(1)),
-                run: Some(Run::Plugin(Some("tab-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "tab-bar".into(),
+                    ..Default::default()
+                }))),
             },
             Layout {
                 direction: Direction::Vertical,
@@ -59,7 +62,10 @@ fn default_layout_merged_correctly() {
                 borderless: true,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(2)),
-                run: Some(Run::Plugin(Some("status-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "status-bar".into(),
+                    ..Default::default()
+                }))),
             },
         ],
         split_size: None,
@@ -83,7 +89,10 @@ fn default_layout_new_tab_correct() {
                 borderless: true,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(1)),
-                run: Some(Run::Plugin(Some("tab-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "tab-bar".into(),
+                    ..Default::default()
+                }))),
             },
             Layout {
                 direction: Direction::Horizontal,
@@ -97,7 +106,10 @@ fn default_layout_new_tab_correct() {
                 borderless: true,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(2)),
-                run: Some(Run::Plugin(Some("status-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "status-bar".into(),
+                    ..Default::default()
+                }))),
             },
         ],
         split_size: None,
@@ -253,7 +265,10 @@ fn three_panes_with_tab_and_default_plugins_merged_correctly() {
                 borderless: false,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(1)),
-                run: Some(Run::Plugin(Some("tab-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "tab-bar".into(),
+                    ..Default::default()
+                }))),
             },
             Layout {
                 direction: Direction::Vertical,
@@ -297,7 +312,10 @@ fn three_panes_with_tab_and_default_plugins_merged_correctly() {
                 borderless: false,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(2)),
-                run: Some(Run::Plugin(Some("status-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "status-bar".into(),
+                    ..Default::default()
+                }))),
             },
         ],
         split_size: None,
@@ -321,7 +339,10 @@ fn three_panes_with_tab_and_default_plugins_new_tab_is_correct() {
                 borderless: false,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(1)),
-                run: Some(Run::Plugin(Some("tab-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "tab-bar".into(),
+                    ..Default::default()
+                }))),
             },
             Layout {
                 direction: Direction::Horizontal,
@@ -335,7 +356,10 @@ fn three_panes_with_tab_and_default_plugins_new_tab_is_correct() {
                 borderless: false,
                 parts: vec![],
                 split_size: Some(SplitSize::Fixed(2)),
-                run: Some(Run::Plugin(Some("status-bar".into()))),
+                run: Some(Run::Plugin(Some(RunPlugin {
+                    path: "status-bar".into(),
+                    ..Default::default()
+                }))),
             },
         ],
         split_size: None,