Support for audio in ph-init

ph-init/src/audio.rs

@@ -0,0 +1,71 @@
+use std::fs;
+use crate::{Error, sys, warn};
+use crate::error::Result;
+use std::path::Path;
+
+const DAEMON_CONF: &str = r#"
+log-target = file:/tmp/pulseaudio.log
+log-level = debug
+"#;
+
+// If extra-arguments is not set, pulseaudio will be launched with
+// '--log-target=syslog' which overrides the log settings in daemon.conf
+const CLIENT_CONF: &str = r#"
+autospawn = yes
+daemon-binary = /usr/bin/pulseaudio
+extra-arguments = --
+"#;
+
+const DEFAULT_PA: &str = r#"
+load-module module-device-restore
+load-module module-stream-restore
+load-module module-card-restore
+
+load-module module-alsa-sink device=hw:0,0
+load-module module-native-protocol-unix
+load-module module-always-sink
+"#;
+
+const SOUND_DEVICES_PATH: &str = "/dev/snd";
+const PULSE_RUN_PATH: &str = "/run/ph/pulse";
+
+pub struct AudioSupport;
+
+impl AudioSupport {
+    pub fn setup() -> Result<()> {
+        if Path::new(SOUND_DEVICES_PATH).exists() {
+            Self::setup_sound_devices()?;
+            Self::setup_pulse_audio_config()?;
+        }
+        Ok(())
+    }
+
+    fn setup_sound_devices() -> Result<()> {
+        for entry in fs::read_dir(SOUND_DEVICES_PATH)
+            .map_err(Error::DevSndReadDir)? {
+            let entry = entry.map_err(Error::DevSndReadDir)?;
+            let path = entry.path();
+            if let Some(path_str) = path.as_os_str().to_str() {
+                sys::chmod(path_str, 0o666)?;
+            }
+        }
+        Ok(())
+    }
+
+    fn write_config_file(name: &str, content: &str) -> Result<()> {
+        let pulse_run_path = Path::new(PULSE_RUN_PATH);
+        fs::write(pulse_run_path.join(name), content)
+            .map_err(Error::PulseAudioConfigWrite)
+    }
+
+    fn setup_pulse_audio_config() -> Result<()> {
+        fs::create_dir_all(PULSE_RUN_PATH)
+            .map_err(Error::PulseAudioConfigWrite)?;
+        Self::write_config_file("daemon.conf", DAEMON_CONF)?;
+        Self::write_config_file("client.conf", CLIENT_CONF)?;
+        Self::write_config_file("default.pa", DEFAULT_PA)?;
+        sys::bind_mount(PULSE_RUN_PATH, "/etc/pulse")?;
+        Ok(())
+    }
+}
+

ph-init/src/error.rs

@@ -30,6 +30,8 @@ pub enum Error {
     MountOverlay(io::Error),
     #[error("failed to move mount from {0} to {1}: {2}")]
     MoveMount(String, String, io::Error),
+    #[error("failed to bind mount from {0} to {1}: {2}")]
+    BindMount(String, String, io::Error),
     #[error("failed to mount 9p volume {0} at {1}: {2}")]
     Mount9P(String, String, io::Error),
     #[error("failed to unmount {0}: {1}")]
@@ -68,6 +70,10 @@ pub enum Error {
     WriteBashrc(io::Error),
     #[error("error configuring network: {0}")]
     NetworkConfigure(netlink::Error),
+    #[error("error reading /dev/snd: {0}")]
+    DevSndReadDir(io::Error),
+    #[error("error writing pulse audio config file: {0}")]
+    PulseAudioConfigWrite(io::Error),
 }
 
 pub type Result<T> = result::Result<T, Error>;

ph-init/src/init.rs

@@ -9,6 +9,7 @@ use std::collections::BTreeMap;
 use std::io::Read;
 use std::net::Ipv4Addr;
 use std::str::FromStr;
+use crate::audio::AudioSupport;
 use crate::netlink::NetlinkSocket;
 
 const BASHRC: &str = r#"
@@ -117,6 +118,8 @@ impl InitServer {
         mkdir("/run/user/1000")?;
         chown("/run/user/1000", 1000,1000)?;
 
+        AudioSupport::setup()?;
+
         self.mount_home_if_exists()?;
         Logger::set_file_output("/run/phinit.log")
             .map_err(Error::OpenLogFailed)?;

ph-init/src/main.rs

@@ -1,6 +1,7 @@
 #[macro_use]
 extern crate lazy_static;
 
+mod audio;
 #[macro_use]
 mod log;
 mod error;

ph-init/src/sys.rs

@@ -69,6 +69,11 @@ pub fn move_mount(source: &str, target: &str) -> Result<()> {
         .map_err(|e| Error::MoveMount(source.to_string(), target.to_string(), e))
 }
 
+pub fn bind_mount(source: &str, target: &str) -> Result<()> {
+    mount(source, target, "", libc::MS_BIND, None)
+        .map_err(|e| Error::BindMount(source.to_string(), target.to_string(), e))
+}
+
 pub fn mount_9p(name: &str, target: &str) -> Result<()> {
     const MS_LAZYTIME: libc::c_ulong = 1 << 25;
     mount(name, target, "9p",