| 1 | //! Greeter process management |
| 2 | //! |
| 3 | //! Spawns and manages the greeter UI process. |
| 4 | |
| 5 | use anyhow::{Context, Result}; |
| 6 | use nix::unistd::User; |
| 7 | use std::os::unix::process::CommandExt; |
| 8 | use std::process::{Child, Command, ExitStatus, Stdio}; |
| 9 | |
| 10 | /// Greeter process wrapper |
| 11 | pub struct GreeterProcess { |
| 12 | process: Child, |
| 13 | } |
| 14 | |
| 15 | impl GreeterProcess { |
| 16 | /// Start the greeter process |
| 17 | /// |
| 18 | /// If a `gardm` user exists, runs the greeter as that user. |
| 19 | /// Otherwise runs as the current user (for development). |
| 20 | pub fn start(greeter_cmd: &str, display: &str) -> Result<Self> { |
| 21 | let mut cmd = Command::new(greeter_cmd); |
| 22 | |
| 23 | cmd.env("DISPLAY", display) |
| 24 | .env("XDG_SESSION_CLASS", "greeter") |
| 25 | .env("XDG_SESSION_TYPE", "x11") |
| 26 | .stdout(Stdio::inherit()) |
| 27 | .stderr(Stdio::inherit()); |
| 28 | |
| 29 | // Try to run as gardm user if it exists |
| 30 | if let Some(user) = User::from_name("gardm").ok().flatten() { |
| 31 | let uid = user.uid; |
| 32 | let gid = user.gid; |
| 33 | let home = user.dir.to_string_lossy().to_string(); |
| 34 | |
| 35 | cmd.env("HOME", &home); |
| 36 | cmd.env("USER", "gardm"); |
| 37 | cmd.env("LOGNAME", "gardm"); |
| 38 | |
| 39 | unsafe { |
| 40 | cmd.pre_exec(move || { |
| 41 | nix::unistd::setgid(gid)?; |
| 42 | nix::unistd::setuid(uid)?; |
| 43 | Ok(()) |
| 44 | }); |
| 45 | } |
| 46 | |
| 47 | tracing::debug!("Starting greeter as gardm user"); |
| 48 | } else { |
| 49 | tracing::warn!("gardm user not found, running greeter as current user"); |
| 50 | } |
| 51 | |
| 52 | let process = cmd.spawn().context("Failed to spawn greeter")?; |
| 53 | |
| 54 | tracing::info!( |
| 55 | greeter = greeter_cmd, |
| 56 | pid = process.id(), |
| 57 | "Started greeter" |
| 58 | ); |
| 59 | |
| 60 | Ok(Self { process }) |
| 61 | } |
| 62 | |
| 63 | /// Check if greeter is still running |
| 64 | pub fn is_running(&mut self) -> bool { |
| 65 | matches!(self.process.try_wait(), Ok(None)) |
| 66 | } |
| 67 | |
| 68 | /// Wait for greeter to exit |
| 69 | pub fn wait(&mut self) -> Result<ExitStatus> { |
| 70 | self.process.wait().context("Failed to wait for greeter") |
| 71 | } |
| 72 | |
| 73 | /// Kill the greeter process |
| 74 | pub fn kill(&mut self) -> Result<()> { |
| 75 | tracing::info!(pid = self.process.id(), "Killing greeter"); |
| 76 | |
| 77 | // Send SIGTERM first |
| 78 | let _ = nix::sys::signal::kill( |
| 79 | nix::unistd::Pid::from_raw(self.process.id() as i32), |
| 80 | nix::sys::signal::Signal::SIGTERM, |
| 81 | ); |
| 82 | |
| 83 | // Wait briefly for graceful exit |
| 84 | std::thread::sleep(std::time::Duration::from_millis(200)); |
| 85 | |
| 86 | // Force kill if still running |
| 87 | if self.is_running() { |
| 88 | self.process.kill().ok(); |
| 89 | } |
| 90 | |
| 91 | self.process.wait().context("Failed to wait for greeter")?; |
| 92 | Ok(()) |
| 93 | } |
| 94 | |
| 95 | /// Get the process ID |
| 96 | pub fn pid(&self) -> u32 { |
| 97 | self.process.id() |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | impl Drop for GreeterProcess { |
| 102 | fn drop(&mut self) { |
| 103 | if self.is_running() { |
| 104 | if let Err(e) = self.kill() { |
| 105 | tracing::warn!(error = %e, "Failed to kill greeter on drop"); |
| 106 | } |
| 107 | } |
| 108 | } |
| 109 | } |
| 110 |