From b21346064eff53a2e090bea5b00ac93441c0ce67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jon=20H=C3=A4ggblad?= <jon.haggblad@gmail.com>
Date: Wed, 7 Feb 2024 10:18:23 +0100
Subject: [PATCH] Add disconnect request/response for the future

---
 common/ip-packet-requests/src/request.rs      | 24 +++++++++++++++++++
 common/ip-packet-requests/src/response.rs     | 24 +++++++++++++++++++
 .../ip-packet-router/src/mixnet_listener.rs   | 11 +++++++++
 3 files changed, 59 insertions(+)

diff --git a/common/ip-packet-requests/src/request.rs b/common/ip-packet-requests/src/request.rs
index f6bc485d0d..9900ce3784 100644
--- a/common/ip-packet-requests/src/request.rs
+++ b/common/ip-packet-requests/src/request.rs
@@ -60,6 +60,20 @@ impl IpPacketRequest {
         )
     }
 
+    pub fn new_disconnect_request(reply_to: Recipient) -> (Self, u64) {
+        let request_id = generate_random();
+        (
+            Self {
+                version: CURRENT_VERSION,
+                data: IpPacketRequestData::Disconnect(DisconnectRequest {
+                    request_id,
+                    reply_to,
+                }),
+            },
+            request_id,
+        )
+    }
+
     pub fn new_ip_packet(ip_packet: bytes::Bytes) -> Self {
         Self {
             version: CURRENT_VERSION,
@@ -71,6 +85,7 @@ impl IpPacketRequest {
         match &self.data {
             IpPacketRequestData::StaticConnect(request) => Some(request.request_id),
             IpPacketRequestData::DynamicConnect(request) => Some(request.request_id),
+            IpPacketRequestData::Disconnect(request) => Some(request.request_id),
             IpPacketRequestData::Data(_) => None,
         }
     }
@@ -79,6 +94,7 @@ impl IpPacketRequest {
         match &self.data {
             IpPacketRequestData::StaticConnect(request) => Some(&request.reply_to),
             IpPacketRequestData::DynamicConnect(request) => Some(&request.reply_to),
+            IpPacketRequestData::Disconnect(request) => Some(&request.reply_to),
             IpPacketRequestData::Data(_) => None,
         }
     }
@@ -101,6 +117,7 @@ impl IpPacketRequest {
 pub enum IpPacketRequestData {
     StaticConnect(StaticConnectRequest),
     DynamicConnect(DynamicConnectRequest),
+    Disconnect(DisconnectRequest),
     Data(DataRequest),
 }
 
@@ -131,6 +148,13 @@ pub struct DynamicConnectRequest {
     pub reply_to_avg_mix_delays: Option<f64>,
 }
 
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+pub struct DisconnectRequest {
+    pub request_id: u64,
+    // The nym-address the response should be sent back to
+    pub reply_to: Recipient,
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 pub struct DataRequest {
     pub ip_packet: bytes::Bytes,
diff --git a/common/ip-packet-requests/src/response.rs b/common/ip-packet-requests/src/response.rs
index 2703f6aec2..053d8552b6 100644
--- a/common/ip-packet-requests/src/response.rs
+++ b/common/ip-packet-requests/src/response.rs
@@ -105,6 +105,7 @@ impl IpPacketResponse {
         match &self.data {
             IpPacketResponseData::StaticConnect(response) => Some(response.request_id),
             IpPacketResponseData::DynamicConnect(response) => Some(response.request_id),
+            IpPacketResponseData::Disconnect(response) => Some(response.request_id),
             IpPacketResponseData::Data(_) => None,
             IpPacketResponseData::Error(response) => Some(response.request_id),
         }
@@ -114,6 +115,7 @@ impl IpPacketResponse {
         match &self.data {
             IpPacketResponseData::StaticConnect(response) => Some(&response.reply_to),
             IpPacketResponseData::DynamicConnect(response) => Some(&response.reply_to),
+            IpPacketResponseData::Disconnect(response) => Some(&response.reply_to),
             IpPacketResponseData::Data(_) => None,
             IpPacketResponseData::Error(response) => Some(&response.reply_to),
         }
@@ -137,6 +139,7 @@ impl IpPacketResponse {
 pub enum IpPacketResponseData {
     StaticConnect(StaticConnectResponse),
     DynamicConnect(DynamicConnectResponse),
+    Disconnect(DisconnectResponse),
     Data(DataResponse),
     Error(ErrorResponse),
 }
@@ -210,6 +213,27 @@ pub enum DynamicConnectFailureReason {
     Other(String),
 }
 
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct DisconnectResponse {
+    pub request_id: u64,
+    pub reply_to: Recipient,
+    pub reply: DisconnectResponseReply,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum DisconnectResponseReply {
+    Success,
+    Failure(DisconnectFailureReason),
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, thiserror::Error)]
+pub enum DisconnectFailureReason {
+    #[error("requested nym-address is not currently connected")]
+    RequestedNymAddressNotConnected,
+    #[error("{0}")]
+    Other(String),
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct DataResponse {
     pub ip_packet: bytes::Bytes,
diff --git a/service-providers/ip-packet-router/src/mixnet_listener.rs b/service-providers/ip-packet-router/src/mixnet_listener.rs
index 3edc2d2123..0031683e53 100644
--- a/service-providers/ip-packet-router/src/mixnet_listener.rs
+++ b/service-providers/ip-packet-router/src/mixnet_listener.rs
@@ -305,6 +305,14 @@ impl MixnetListener {
         )))
     }
 
+    fn on_disconnect_request(
+        &self,
+        _disconnect_request: nym_ip_packet_requests::request::DisconnectRequest,
+    ) -> Result<Option<IpPacketResponse>> {
+        log::info!("Received disconnect request: not implemented, dropping");
+        Ok(None)
+    }
+
     async fn on_data_request(
         &mut self,
         data_request: nym_ip_packet_requests::request::DataRequest,
@@ -411,6 +419,9 @@ impl MixnetListener {
             IpPacketRequestData::DynamicConnect(connect_request) => {
                 self.on_dynamic_connect_request(connect_request).await
             }
+            IpPacketRequestData::Disconnect(disconnect_request) => {
+                self.on_disconnect_request(disconnect_request)
+            }
             IpPacketRequestData::Data(data_request) => self.on_data_request(data_request).await,
         }
     }