allow dead Connection unless a transport needs it

3 files changed, 15 insertions, 2 deletions

diff --git a/docs/openapi.yaml b/docs/openapi.yaml
index 6de726c..1d9a5e9 100644
--- a/docs/openapi.yaml
+++ b/docs/openapi.yaml
@@ -1148,7 +1148,7 @@ components:
                 connection:
                   type: [string, 'null']
                   enum: [direct, relayed, null]
-                  description: The libp2p connection to it; null if none, or on a transport without connections (Mycelium).
+                  description: 'The connection to it: libp2p''s direct or through a relay, Tor''s always direct (an onion circuit, no relay of ours); null if none, or on a transport without connections (Mycelium).'
                 punching:
                   type: object
                   description: 'While it is connected only through a relay and a hole punch failed: how often in a row, and when the next try is (after 1, 5, then every 30 minutes). Absent otherwise.'
diff --git a/src/transport/mod.rs b/src/transport/mod.rs
index 40fdfc0..b10c799 100644
--- a/src/transport/mod.rs
+++ b/src/transport/mod.rs
@@ -382,9 +382,13 @@ pub(crate) struct Punching {
 /// How a transport with connections (libp2p) is connected to a peer.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
 #[serde(rename_all = "camelCase")]
+// Only libp2p and Tor have connections; without both (the cargo features) nothing makes
+// one.
+#[cfg_attr(not(any(feature = "libp2p", feature = "tor")), allow(dead_code))]
 pub(crate) enum Connection {
+    /// libp2p's to the peer itself; Tor's always (an onion circuit).
     Direct,
-    /// Only through a relay.
+    /// Only through a relay (libp2p).
     Relayed,
 }
 
diff --git a/src/transport/tor.rs b/src/transport/tor.rs
index 39e0f31..2cf3249 100644
--- a/src/transport/tor.rs
+++ b/src/transport/tor.rs
@@ -544,6 +544,15 @@ impl Transport for TorTransport {
         parse_location(target)
     }
 
+    /// Direct while a connection to its onion service is open: an onion circuit, with no
+    /// relay of ours in between.
+    fn connection(&self, target: &str) -> Option<crate::transport::Connection> {
+        let location = parse_location(target)?;
+        lock(&self.shared.connections)
+            .contains_key(&location)
+            .then_some(crate::transport::Connection::Direct)
+    }
+
     /// An onion service is its own transport identity: nothing to find out.
     async fn resolve_seed(&self, seed: &str) -> Result<String> {
         let location = parse_location(seed)