From 846d0a2be3e0e982005fc5f7801a9be477879dcd Mon Sep 17 00:00:00 2001
From: Federico Terzi <federicoterzi96@gmail.com>
Date: Mon, 1 Nov 2021 21:00:51 +0100
Subject: [PATCH] fix(core): prevent certain commands from being run as root on
 macOS. Fix #648

---
 espanso/src/cli/daemon/mod.rs    |  4 +++-
 espanso/src/cli/service/macos.rs |  6 ++++++
 espanso/src/cli/util.rs          | 16 ++++++++++++++++
 espanso/src/cli/worker/mod.rs    |  3 +++
 espanso/src/exit_code.rs         |  3 +++
 5 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/espanso/src/cli/daemon/mod.rs b/espanso/src/cli/daemon/mod.rs
index 1b1c2fe..206ad73 100644
--- a/espanso/src/cli/daemon/mod.rs
+++ b/espanso/src/cli/daemon/mod.rs
@@ -28,7 +28,7 @@ use espanso_path::Paths;
 use log::{error, info, warn};
 
 use crate::{
-  cli::util::CommandExt,
+  cli::util::{prevent_running_as_root_on_macos, CommandExt},
   common_flags::*,
   exit_code::{
     DAEMON_ALREADY_RUNNING, DAEMON_FATAL_CONFIG_ERROR, DAEMON_GENERAL_ERROR,
@@ -60,6 +60,8 @@ pub fn new() -> CliModule {
 }
 
 fn daemon_main(args: CliModuleArgs) -> i32 {
+  prevent_running_as_root_on_macos();
+
   let paths = args.paths.expect("missing paths in daemon main");
   let paths_overrides = args
     .paths_overrides
diff --git a/espanso/src/cli/service/macos.rs b/espanso/src/cli/service/macos.rs
index f6914f5..cbf1b8c 100644
--- a/espanso/src/cli/service/macos.rs
+++ b/espanso/src/cli/service/macos.rs
@@ -23,12 +23,16 @@ use std::process::Command;
 use std::{fs::create_dir_all, process::ExitStatus};
 use thiserror::Error;
 
+use crate::cli::util::prevent_running_as_root_on_macos;
+
 #[cfg(target_os = "macos")]
 const SERVICE_PLIST_CONTENT: &str = include_str!("../../res/macos/com.federicoterzi.espanso.plist");
 #[cfg(target_os = "macos")]
 const SERVICE_PLIST_FILE_NAME: &str = "com.federicoterzi.espanso.plist";
 
 pub fn register() -> Result<()> {
+  prevent_running_as_root_on_macos();
+
   let home_dir = dirs::home_dir().expect("could not get user home directory");
   let library_dir = home_dir.join("Library");
   let agents_dir = library_dir.join("LaunchAgents");
@@ -94,6 +98,8 @@ pub enum RegisterError {
 }
 
 pub fn unregister() -> Result<()> {
+  prevent_running_as_root_on_macos();
+
   let home_dir = dirs::home_dir().expect("could not get user home directory");
   let library_dir = home_dir.join("Library");
   let agents_dir = library_dir.join("LaunchAgents");
diff --git a/espanso/src/cli/util.rs b/espanso/src/cli/util.rs
index e029a74..401ce2c 100644
--- a/espanso/src/cli/util.rs
+++ b/espanso/src/cli/util.rs
@@ -53,3 +53,19 @@ impl CommandExt for Command {
     self
   }
 }
+
+// For context, see also this issue: https://github.com/federico-terzi/espanso/issues/648
+#[cfg(target_os = "macos")]
+pub fn prevent_running_as_root_on_macos() {
+  use crate::{error_eprintln, exit_code::UNEXPECTED_RUN_AS_ROOT};
+
+  if unsafe { libc::geteuid() } == 0 {
+    error_eprintln!("Espanso is being run as root, but this can create unwanted side-effects. Please run it as a normal user.");
+    std::process::exit(UNEXPECTED_RUN_AS_ROOT);
+  }
+}
+
+#[cfg(not(target_os = "macos"))]
+pub fn prevent_running_as_root_on_macos() {
+  // Do nothing on other platforms
+}
diff --git a/espanso/src/cli/worker/mod.rs b/espanso/src/cli/worker/mod.rs
index f5dd997..b2cf019 100644
--- a/espanso/src/cli/worker/mod.rs
+++ b/espanso/src/cli/worker/mod.rs
@@ -22,6 +22,7 @@ use espanso_engine::event::ExitMode;
 use log::{debug, error, info};
 
 use crate::{
+  cli::util::prevent_running_as_root_on_macos,
   exit_code::{
     WORKER_ALREADY_RUNNING, WORKER_EXIT_ALL_PROCESSES, WORKER_GENERAL_ERROR,
     WORKER_LEGACY_ALREADY_RUNNING, WORKER_RESTART, WORKER_SUCCESS,
@@ -58,6 +59,8 @@ pub fn new() -> CliModule {
 }
 
 fn worker_main(args: CliModuleArgs) -> i32 {
+  prevent_running_as_root_on_macos();
+
   let paths = args.paths.expect("missing paths in worker main");
   let cli_args = args.cli_args.expect("missing cli_args in worker main");
 
diff --git a/espanso/src/exit_code.rs b/espanso/src/exit_code.rs
index 01ade17..15be31b 100644
--- a/espanso/src/exit_code.rs
+++ b/espanso/src/exit_code.rs
@@ -68,6 +68,9 @@ pub const PACKAGE_LIST_FAILED: i32 = 4;
 pub const PACKAGE_UPDATE_FAILED: i32 = 5;
 pub const PACKAGE_UPDATE_PARTIAL_FAILURE: i32 = 6;
 
+#[allow(dead_code)]
+pub const UNEXPECTED_RUN_AS_ROOT: i32 = 42;
+
 use std::sync::Mutex;
 
 use crate::error_eprintln;