refactor(relay): use RangeInclusive to specify available ports (#5820)

rust/connlib/snownet/tests/lib.rs

@@ -351,7 +351,7 @@ impl Firewall {
 impl TestRelay {
     fn new(local: impl Into<RelaySocket>, span: Span) -> Self {
         let local = local.into();
-        let inner = firezone_relay::Server::new(to_ip_stack(local), OsRng, 3478, 49152, 65535);
+        let inner = firezone_relay::Server::new(to_ip_stack(local), OsRng, 3478, 49152..=65535);
 
         Self {
             inner,

rust/connlib/tunnel/src/tests/sut.rs

@@ -91,8 +91,7 @@ impl StateMachineTest for TunnelTest {
                             IpStack::from((ip4, ip6)),
                             rand::rngs::StdRng::seed_from_u64(seed),
                             3478,
-                            49152,
-                            65535,
+                            49152..=65535,
                         ))
                     },
                     debug_span!("relay", rid = %id),

rust/relay/src/main.rs

@@ -114,8 +114,7 @@ async fn main() -> Result<()> {
         public_addr,
         make_rng(args.rng_seed),
         args.listen_port,
-        args.lowest_port,
-        args.highest_port,
+        args.lowest_port..=args.highest_port,
     );
 
     let last_heartbeat_sent = Arc::new(Mutex::new(Option::<Instant>::None));

rust/relay/src/server.rs

@@ -20,6 +20,7 @@ use secrecy::SecretString;
 use std::collections::{HashMap, VecDeque};
 use std::hash::Hash;
 use std::net::{IpAddr, SocketAddr};
+use std::ops::RangeInclusive;
 use std::time::{Duration, Instant, SystemTime};
 use stun_codec::rfc5389::attributes::{
     ErrorCode, MessageIntegrity, Nonce, Realm, Username, XorMappedAddress,
@@ -62,8 +63,8 @@ pub struct Server<R> {
         HashMap<(AllocationPort, PeerSocket), (ClientSocket, ChannelNumber)>,
 
     listen_port: u16,
-    lowest_port: u16,
-    highest_port: u16,
+
+    ports: RangeInclusive<u16>,
 
     /// Channel numbers are unique by client, thus indexed by both.
     channels_by_client_and_number: HashMap<(ClientSocket, ChannelNumber), Channel>,
@@ -157,8 +158,7 @@ where
         public_address: impl Into<IpStack>,
         mut rng: R,
         listen_port: u16,
-        lowest_port: u16,
-        highest_port: u16,
+        ports: RangeInclusive<u16>,
     ) -> Self {
         // TODO: Validate that local IP isn't multicast / loopback etc.
 
@@ -185,8 +185,7 @@ where
             allocations: Default::default(),
             clients_by_allocation: Default::default(),
             listen_port,
-            lowest_port,
-            highest_port,
+            ports,
             channels_by_client_and_number: Default::default(),
             channel_numbers_by_client_and_peer: Default::default(),
             pending_commands: Default::default(),
@@ -807,7 +806,7 @@ where
         );
 
         let port = loop {
-            let candidate = AllocationPort(self.rng.gen_range(self.lowest_port..self.highest_port));
+            let candidate = AllocationPort(self.rng.gen_range(self.ports.clone()));
 
             if !self.clients_by_allocation.contains_key(&candidate) {
                 break candidate;
@@ -823,7 +822,7 @@ where
     }
 
     fn max_available_ports(&self) -> u16 {
-        self.highest_port - self.lowest_port
+        self.ports.clone().count() as u16
     }
 
     fn create_channel_binding(

rust/relay/tests/regression.rs

@@ -696,7 +696,7 @@ struct TestServer {
 impl TestServer {
     fn new(relay_public_addr: impl Into<IpStack>) -> Self {
         Self {
-            server: Server::new(relay_public_addr, StepRng::new(0, 0), 3478, 49152, 65535),
+            server: Server::new(relay_public_addr, StepRng::new(0, 0), 3478, 49152..=65535),
         }
     }