Use once_cell to allow for global static immutable options

So they don't have to be passed around all over the place

Cargo.lock

@@ -129,6 +129,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da32515d9f6e6e489d7bc9d84c71b060db7247dc035bbe44eac88cf87486d8d5"
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -175,6 +181,7 @@ dependencies = [
 name = "saslauthd"
 version = "0.1.0"
 dependencies = [
+ "once_cell",
  "structopt",
  "syslog",
 ]

Cargo.toml

@@ -6,5 +6,6 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+once_cell = "^1.9.0"
 structopt = "^0.3.26"
 syslog = "^6.0"

src/listener.rs

@@ -4,27 +4,26 @@ use std::os::unix::fs::PermissionsExt;
 use std::os::unix::net::UnixListener;
 use std::thread;
 
-use crate::options::Opt;
+use crate::options::OPTIONS;
 use crate::server::Server;
 
 pub struct Listener {
-    options: Opt,
     listener: UnixListener,
 }
 
 impl Listener {
-    pub fn new(options: Opt) -> Result<Listener, Error> {
-        if options.socket.exists() {
-            std::fs::remove_file(&options.socket)?;
+    pub fn new() -> Result<Listener, Error> {
+        if OPTIONS.socket.exists() {
+            std::fs::remove_file(&OPTIONS.socket)?;
         }
 
-        let listener = UnixListener::bind(&options.socket)?;
+        let listener = UnixListener::bind(&OPTIONS.socket)?;
 
-        let mut perms = metadata(&options.socket)?.permissions();
+        let mut perms = metadata(&OPTIONS.socket)?.permissions();
         perms.set_mode(0o0777);
-        set_permissions(&options.socket, perms)?;
+        set_permissions(&OPTIONS.socket, perms)?;
 
-        Ok(Listener { options, listener })
+        Ok(Listener { listener })
     }
 
     pub fn run(&mut self) -> Result<(), Error> {
@@ -33,8 +32,7 @@ impl Listener {
             match stream {
                 Ok(stream) => {
                     /* connection succeeded */
-                    let options = self.options.clone();
-                    thread::spawn(|| Server::new(options, stream).unwrap().handle_client());
+                    thread::spawn(|| Server::new(stream).unwrap().handle_client());
                 }
                 Err(_err) => {
                     /* connection failed */
@@ -48,7 +46,7 @@ impl Listener {
 
 impl Drop for Listener {
     fn drop(&mut self) {
-        let _result = std::fs::remove_file(&self.options.socket);
+        let _result = std::fs::remove_file(&OPTIONS.socket);
         println!("Shutting down");
     }
-}
+}

src/main.rs

@@ -2,13 +2,9 @@ mod listener;
 mod options;
 mod server;
 
-use structopt::StructOpt;
-
 use crate::listener::Listener;
-use crate::options::Opt;
-
 
 fn main() -> std::io::Result<()> {
-    let mut server = Listener::new(Opt::from_args())?;
+    let mut server = Listener::new()?;
     server.run()
 }

src/options.rs

@@ -1,3 +1,4 @@
+use once_cell::sync::Lazy;
 use std::path::PathBuf;
 use structopt::StructOpt;
 
@@ -21,3 +22,5 @@ pub struct Opt {
     )]
     pub passwords: PathBuf,
 }
+
+pub static OPTIONS: Lazy<Opt> = Lazy::new(Opt::from_args);

src/server.rs

@@ -3,19 +3,18 @@ use std::io::{BufRead, BufReader, Error, ErrorKind, Read, Write};
 use std::net::Shutdown;
 use std::os::unix::net::UnixStream;
 
-use crate::options::Opt;
+use crate::options::OPTIONS;
 
 const RESPONSE_NO: [u8; 4] = [0x0, 0x2, b'N', b'O'];
 const RESPONSE_OK: [u8; 4] = [0x0, 0x2, b'O', b'K'];
 
 pub struct Server {
-    options: Opt,
     stream: UnixStream,
 }
 
 impl Server {
-    pub fn new(options: Opt, stream: UnixStream) -> Result<Server, Error> {
-        Ok(Server { options, stream })
+    pub fn new(stream: UnixStream) -> Result<Server, Error> {
+        Ok(Server { stream })
     }
 
     /// The saslauthd protocol transmits strings as
@@ -60,7 +59,7 @@ impl Server {
             return Ok(false);
         }
 
-        let mut password_file = self.options.passwords.clone();
+        let mut password_file = OPTIONS.passwords.clone();
         password_file.push(&userid);
 
         let file = File::open(password_file)?;