More logging

Cargo.toml

@@ -4,6 +4,10 @@ version = "0.2.0"
 edition = "2021"
 description = "mini-udev workalike"
 
+[features]
+default = ["syslog"]
+syslog = ["dep:syslog-tracing"]
+
 [dependencies]
 anyhow = "1.0.95"
 bytes = "1.9.0"
@@ -14,6 +18,7 @@ kobject-uevent = "0.2.0"
 mdev-parser = "0.1.1"
 netlink-sys = { version = "0.8.7", features = ["tokio_socket"] }
 nix = { version = "0.29.0", features = ["user", "fs"] }
+syslog-tracing = { version = "0.3.1", optional = true }
 thiserror = "2.0.9"
 tokio = { version = "1.42.0", features = [
     "macros",

src/bin/mdev-coldplug.rs

@@ -17,15 +17,17 @@ struct Opt {
 }
 
 impl Opt {
-    fn setup_log(&self) -> anyhow::Result<()> {
-        setup_log(self.verbose)
+    fn setup_log(&self) {
+        use tracing_subscriber::{fmt, prelude::*};
+        let fmt_layer = fmt::layer().with_target(false);
+        setup_log(self.verbose).with(fmt_layer).init();
     }
 }
 
 fn main() -> anyhow::Result<()> {
     let opt = Opt::parse();
 
-    opt.setup_log()?;
+    opt.setup_log();
 
     let classdir = WalkDir::new(opt.sysfs_mount.join("class"))
         .follow_links(true)

src/bin/mdev.rs

@@ -254,15 +254,56 @@ impl Opt {
     }
 
     fn setup_log(&self) -> anyhow::Result<()> {
+        use tracing_subscriber::{fmt, prelude::*};
         if self.daemon && !self.foreground && !self.syslog {
             return Ok(());
         }
 
+        let registry = setup_log(self.verbose);
+        let fmt_layer = fmt::layer().with_target(false);
+
+        let mdev_log = Path::new("/dev/mdev.log");
+        let file_log = if mdev_log.is_file() {
+            let log = std::fs::OpenOptions::new().append(true).open(mdev_log)?;
+            let fmt_layer = fmt::layer()
+                .with_target(false)
+                .with_ansi(false)
+                .with_writer(log);
+            Some(fmt_layer)
+        } else {
+            None
+        };
+
+        let registry = registry.with(file_log);
+
         if self.syslog {
-            todo!("Wire in syslog somehow");
+            #[cfg(feature = "syslog")]
+            {
+                use std::ffi::CString;
+                use syslog_tracing::{Facility, Options, Syslog};
+                // SAFETY: They are strings that do not contain a null byte
+                let identity = std::env::args()
+                    .next()
+                    .map_or_else(|| CString::new("mdev"), |name| CString::new(name))
+                    .unwrap();
+                let syslog = Syslog::new(identity, Options::LOG_PID, Facility::Daemon).unwrap();
+                let fmt_layer = fmt_layer
+                    .with_level(false)
+                    .without_time()
+                    .with_writer(syslog);
+
+                registry.with(fmt_layer).init();
+            }
+            #[cfg(not(feature = "syslog"))]
+            {
+                registry.with(fmt_layer).init();
+                warn!("They syslog feature is disabled");
+            }
+        } else {
+            registry.with(fmt_layer).init();
         }
 
-        setup_log(self.verbose)
+        Ok(())
     }
 }
 

src/lib.rs

@@ -10,6 +10,7 @@ use futures_util::ready;
 use kobject_uevent::UEvent;
 use netlink_sys::{AsyncSocket, SocketAddr, TokioSocket};
 use tokio::sync::mpsc;
+use tracing_subscriber::{layer::Layered, prelude::*, EnvFilter, Registry};
 
 pub mod rule;
 pub mod stream;
@@ -196,12 +197,7 @@ mod tests {
     }
 }
 
-pub fn setup_log(verbose: u8) -> anyhow::Result<()> {
-    use tracing_subscriber::prelude::*;
-    use tracing_subscriber::{fmt, EnvFilter};
-
-    let fmt_layer = fmt::layer().with_target(false);
-
+pub fn setup_log(verbose: u8) -> Layered<EnvFilter, Registry> {
     let filter_layer = EnvFilter::try_from_default_env().unwrap_or_else(|_| {
         if verbose < 1 {
             EnvFilter::new("info")
@@ -212,10 +208,5 @@ pub fn setup_log(verbose: u8) -> anyhow::Result<()> {
         }
     });
 
-    tracing_subscriber::registry()
-        .with(filter_layer)
-        .with(fmt_layer)
-        .init();
-
-    Ok(())
+    tracing_subscriber::registry().with(filter_layer)
 }