Add command line arguments

Replace the hard-coded addresses with clap arguments: --bind <IP> and one or more --peer <IP>. Peers must match the address family of the bind address. Also updates Cargo.lock.

src/bin/rust-bfdd.rs

@@ -1,8 +1,8 @@
+use clap::Parser;
 use futures::future;
 use rust_bfd::events::{EventMessageSink, ScriptHookSink, StateChangeEvent};
-use rust_bfd::{set_ttl_or_hop_limit, BfdSessionStats};
 use rust_bfd::{bfd::*, events::EventMessage};
-use std::net::Ipv6Addr;
+use rust_bfd::{set_ttl_or_hop_limit, BfdSessionStats};
 use std::{
     collections::HashMap,
     error::Error,
@@ -10,7 +10,6 @@ use std::{
     io::ErrorKind,
     mem::swap,
     net::{IpAddr, SocketAddr},
-    str::FromStr,
     sync::{atomic::Ordering, Arc},
     time::{Duration, Instant},
 };
@@ -36,6 +35,18 @@ use atomic::Atomic;
 const CONTROL_PORT: u16 = 3784;
 const ECHO_PORT: u16 = 3785;
 
+#[derive(Parser, Debug)]
+#[command(version, about = "BFD (RFC 5880) daemon")]
+struct Args {
+    /// Local IP address to bind to and use as the source of BFD control packets
+    #[arg(short, long, value_name = "IP")]
+    bind: IpAddr,
+
+    /// Peer IP address to establish a session with (repeatable; must match the bind address family)
+    #[arg(short, long = "peer", value_name = "IP", required = true)]
+    peers: Vec<IpAddr>,
+}
+
 const ORDERING: Ordering = Ordering::Relaxed;
 
 #[derive(Debug)]
@@ -923,14 +934,24 @@ struct Bfdd {
 }
 
 impl Bfdd {
-    async fn new() -> Result<Self, Box<dyn Error>> {
-        // let local = SocketAddr::from_str("192.168.255.2:3784").unwrap();
-        let local = SocketAddr::new(Ipv6Addr::from_str("2001:db8::2").unwrap().into(), 3784);
-        let peers = vec![
-            // SocketAddr::from_str("192.168.122.132:3784").unwrap(),
-            // SocketAddr::from_str("192.168.255.1:3784").unwrap(),
-            SocketAddr::new(Ipv6Addr::from_str("2001:db8::1").unwrap().into(), 3784),
-        ];
+    async fn new(args: Args) -> Result<Self, Box<dyn Error>> {
+        let local = SocketAddr::new(args.bind, CONTROL_PORT);
+        if let Some(peer) = args
+            .peers
+            .iter()
+            .find(|p| p.is_ipv4() != args.bind.is_ipv4())
+        {
+            return Err(format!(
+                "peer {peer} is not the same address family as bind address {}",
+                args.bind
+            )
+            .into());
+        }
+        let peers = args
+            .peers
+            .into_iter()
+            .map(|ip| SocketAddr::new(ip, CONTROL_PORT))
+            .collect();
         let sessions_by_ip = HashMap::new();
         let sessions_by_discr = HashMap::new();
 
@@ -1075,11 +1096,13 @@ impl Bfdd {
 
 #[tokio::main]
 async fn main() -> io::Result<()> {
+    let args = Args::parse();
+
     env_logger::Builder::from_env(Env::default().default_filter_or("info"))
         .format_timestamp_micros()
         .init();
 
-    match Bfdd::new().await {
+    match Bfdd::new(args).await {
         Ok(bfdd) => bfdd.run().await,
         Err(e) => Err(std::io::Error::new(ErrorKind::Other, e.to_string())),
     }