Provide human readable error messages

Cargo.lock

@@ -75,6 +75,12 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"
+
 [[package]]
 name = "async-trait"
 version = "0.1.81"
@@ -205,6 +211,7 @@ checksum = "a7993efb860416547839c115490d4951c6d0f8ec04a3594d9dd99d50ed7ec170"
 name = "dhcpv6stateless"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "clap",
  "dhcproto",
  "hex",

Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+anyhow = "1.0.86"
 clap = { version = "4.5.16", features = ["derive"] }
 dhcproto = "0.12.0"
 hex = "0.4.3"

src/main.rs

@@ -1,3 +1,7 @@
+use anyhow::{
+    Context,
+    Result,
+};
 use clap::Parser;
 use dhcproto::{
     Decodable,
@@ -30,14 +34,14 @@ struct Cli {
 }
 
 #[tokio::main]
-async fn main() {
+async fn main() -> Result<()>{
     let cli = Cli::parse();
 
     let all_interfaces = pnet::datalink::interfaces();
     let selected_interface = all_interfaces
         .iter()
         .find(|i| i.name == cli.interface)
-        .expect(format!("No interface found with name: {}", cli.interface).as_str());
+        .with_context(|| format!("No interface found with name: {}", cli.interface))?;
 
     let ipv6_addresses = selected_interface.ips
         .iter()
@@ -50,10 +54,11 @@ async fn main() {
 
     // Just take the first address found on the interface
     let selected_address = ipv6_link_local_addresses.next()
-        .expect("No IPv6 link local address assigned to this interface");
+        .context("No IPv6 link local address assigned to this interface")?;
 
     let socket_addr = SocketAddrV6::new(selected_address.ip(), DHCP_CLIENT_PORT, 0, selected_interface.index.clone());
-    let sock = UdpSocket::bind(socket_addr).await.unwrap();
+    let sock = UdpSocket::bind(socket_addr).await
+        .context("Unable to bind UDP socket")?;
 
     let remote_addr = SocketAddrV6::new(ALL_DHCP_RELAY_AGENTS_AND_SERVERS.parse().unwrap(), DHCP_RELAY_AGENT_AND_SERVER_PORT, 0, selected_interface.index.clone());
 
@@ -70,14 +75,18 @@ async fn main() {
 
     let mut msg_buf = Vec::new();
     let mut msg_encoder = Encoder::new(&mut msg_buf);
-    msg.encode(&mut msg_encoder).unwrap(); // Serializes msg to msg_buf
+    msg.encode(&mut msg_encoder)
+        .context("Unable to serialize DHCP options for message to send")?; // Serializes msg to msg_buf
 
-    sock.send_to(&msg_buf, remote_addr).await.unwrap();
+    sock.send_to(&msg_buf, remote_addr).await
+        .context("Failed to send DHCPv6 INFORMATION-REQUEST message")?;
 
     loop {
         let mut recv_buf = [0; 1024];
-        let (len, recv_addr) = sock.recv_from(&mut recv_buf).await.unwrap();
-        let recv_msg = Message::decode(&mut Decoder::new(&recv_buf)).unwrap();
+        let (len, recv_addr) = sock.recv_from(&mut recv_buf).await
+            .context("Failed to receive DHCPv6 response")?;
+        let recv_msg = Message::decode(&mut Decoder::new(&recv_buf))
+            .context("Unable to parse DHCPv6 response message")?;
 
         if recv_msg.xid() == msg.xid() {
             println!("{:?} bytes received from {:?}", len, recv_addr);
@@ -86,4 +95,6 @@ async fn main() {
             break;
         }
     }
+
+    Ok(())
 }