Warn if user is running daemon as a non-root user

5 files changed, 21 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9f627d558..9aa5532dd1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Add `--disable-rpc-auth` flag to daemon to make it accept unauthorized control.
 - Add colors to terminal output on macOS and Linux.
 - Add details to mullvad CLI interface error for when it doesn't trust the RPC file.
+- Warn if daemon is running as a non-root user.
 
 ### Fixed
 - Fix a bug in account input field that advanced the cursor to the end regardless its prior
diff --git a/Cargo.lock b/Cargo.lock
index b3dd34d69e..95023a14de 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -673,6 +673,7 @@ dependencies = [
  "jsonrpc-pubsub 7.1.1 (git+https://github.com/paritytech/jsonrpc?tag=v7.1.1)",
  "jsonrpc-ws-server 7.1.1 (git+https://github.com/paritytech/jsonrpc?tag=v7.1.1)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "mullvad-rpc 0.1.0",
  "mullvad-types 0.1.0",
diff --git a/mullvad-daemon/Cargo.toml b/mullvad-daemon/Cargo.toml
index 6bba73bbd3..0c4c1a109f 100644
--- a/mullvad-daemon/Cargo.toml
+++ b/mullvad-daemon/Cargo.toml
@@ -15,6 +15,7 @@ fern = { version = "0.5", features = ["colored"] }
 futures = "0.1"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+libc = "0.2"
 log = "0.4"
 jsonrpc-core = { git = "https://github.com/paritytech/jsonrpc", tag = "v7.1.1" }
 jsonrpc-macros = { git = "https://github.com/paritytech/jsonrpc", tag = "v7.1.1" }
diff --git a/mullvad-daemon/src/main.rs b/mullvad-daemon/src/main.rs
index d6cc7755fc..631fe2cdd1 100644
--- a/mullvad-daemon/src/main.rs
+++ b/mullvad-daemon/src/main.rs
@@ -14,6 +14,7 @@ extern crate clap;
 #[macro_use]
 extern crate error_chain;
 extern crate futures;
+extern crate libc;
 #[macro_use]
 extern crate log;
 
diff --git a/mullvad-daemon/src/rpc_info.rs b/mullvad-daemon/src/rpc_info.rs
index b5b35fa8f7..33a27828eb 100644
--- a/mullvad-daemon/src/rpc_info.rs
+++ b/mullvad-daemon/src/rpc_info.rs
@@ -2,6 +2,8 @@ use std::fs::{self, File, OpenOptions};
 use std::io::{self, Write};
 use std::path::{Path, PathBuf};
 
+use libc;
+
 error_chain! {
     errors {
         WriteFailed(path: PathBuf) {
@@ -47,6 +49,9 @@ pub fn remove() -> Result<()> {
 }
 
 fn open_file(path: &Path) -> io::Result<File> {
+    if !user_is_root() {
+        warn!("Running daemon as a non-root user, clients might refuse to connect");
+    }
     let file = OpenOptions::new()
         .write(true)
         .truncate(true)
@@ -57,6 +62,18 @@ fn open_file(path: &Path) -> io::Result<File> {
 }
 
 #[cfg(unix)]
+fn user_is_root() -> bool {
+    let uid = unsafe { libc::getuid() };
+    uid == 0
+}
+
+#[cfg(windows)]
+fn user_is_root() -> bool {
+    // TODO: Check if user is administrator correctly on Windows.
+    true
+}
+
+#[cfg(unix)]
 fn set_rpc_file_permissions(file: &File) -> io::Result<()> {
     use std::os::unix::fs::PermissionsExt;
     file.set_permissions(PermissionsExt::from_mode(0o644))