gateway(fix): accept nil expiration times (#3288)

Fixes #3240

rust/connlib/tunnel/src/control_protocol/gateway.rs

@@ -63,7 +63,7 @@ where
         peer: PeerConfig,
         relays: Vec<Relay>,
         client_id: ClientId,
-        expires_at: DateTime<Utc>,
+        expires_at: Option<DateTime<Utc>>,
         resource: ResourceDescription,
     ) -> Result<ConnectionAccepted> {
         let IceConnection {
@@ -166,7 +166,7 @@ where
         &self,
         resource: ResourceDescription,
         client_id: ClientId,
-        expires_at: DateTime<Utc>,
+        expires_at: Option<DateTime<Utc>>,
         domain: Option<Dname>,
     ) -> Option<ResourceAccepted> {
         if let Some((_, peer)) = self
@@ -220,7 +220,7 @@ where
         peer_config: PeerConfig,
         client_id: ClientId,
         resource: ResourceDescription,
-        expires_at: DateTime<Utc>,
+        expires_at: Option<DateTime<Utc>>,
         ice: Arc<RTCIceTransport>,
         resource_addresses: Vec<IpNetwork>,
     ) -> Result<()> {

rust/connlib/tunnel/src/peer.rs

@@ -23,7 +23,7 @@ use crate::client::IpProvider;
 use crate::MAX_UDP_SIZE;
 use crate::{device_channel, ip_packet::MutableIpPacket, PeerConfig};
 
-type ExpiryingResource = (ResourceDescription, DateTime<Utc>);
+type ExpiryingResource = (ResourceDescription, Option<DateTime<Utc>>);
 
 // The max time a dns request can be configured to live in resolvconf
 // is 30 seconds. See resolvconf(5) timeout.
@@ -240,14 +240,16 @@ impl PacketTransformGateway {
     }
 
     pub(crate) fn expire_resources(&self) {
-        self.resources.write().retain(|_, (_, e)| *e > Utc::now());
+        self.resources
+            .write()
+            .retain(|_, (_, e)| !e.is_some_and(|e| e <= Utc::now()));
     }
 
     pub(crate) fn add_resource(
         &self,
         ip: IpNetwork,
         resource: ResourceDescription,
-        expires_at: DateTime<Utc>,
+        expires_at: Option<DateTime<Utc>>,
     ) {
         self.resources.write().insert(ip, (resource, expires_at));
     }

rust/gateway/src/eventloop.rs

@@ -167,7 +167,7 @@ impl Eventloop {
                     payload,
                     reference,
                 }))) => {
-                    tracing::debug!(client = %client_id, resource = %resource.id(), expires = %expires_at.to_rfc3339() ,"Allowing access to resource");
+                    tracing::debug!(client = %client_id, resource = %resource.id(), expires = ?expires_at.map(|e| e.to_rfc3339()), "Allowing access to resource");
 
                     if let Some(res) = self
                         .tunnel

rust/gateway/src/messages.rs

@@ -1,4 +1,4 @@
-use chrono::{serde::ts_seconds, DateTime, Utc};
+use chrono::{serde::ts_seconds_option, DateTime, Utc};
 use connlib_shared::{
     messages::{
         ActorId, ClientId, ClientPayload, GatewayResponse, Interface, Peer, Relay,
@@ -48,8 +48,8 @@ pub struct RequestConnection {
     pub client: Client,
     #[serde(rename = "ref")]
     pub reference: String,
-    #[serde(with = "ts_seconds")]
-    pub expires_at: DateTime<Utc>,
+    #[serde(with = "ts_seconds_option")]
+    pub expires_at: Option<DateTime<Utc>>,
 }
 
 #[derive(Debug, Deserialize, Serialize, Clone, PartialEq, Eq)]
@@ -80,8 +80,8 @@ pub struct RemoveResource {
 pub struct AllowAccess {
     pub client_id: ClientId,
     pub resource: ResourceDescription,
-    #[serde(with = "ts_seconds")]
-    pub expires_at: DateTime<Utc>,
+    #[serde(with = "ts_seconds_option")]
+    pub expires_at: Option<DateTime<Utc>>,
     pub payload: Option<Dname>,
     #[serde(rename = "ref")]
     pub reference: String,