Deduce ldk-server network via its API

Previously we had to specify the network in the config file. Now, as the
network field is added to the get-node-info response we can deduce it
ourselves.

Author: randomlogin

Cargo.lock

@@ -104,13 +104,12 @@ The required access details will depend on the node implementation.
 {
   "address": <ip:port or domain:port>,
   "api_key": <hex_encoded_api_key>,
-  "cert": <path_to_tls_cert>,
-  "network": <bitcoin|testnet|signet|regtest>
+  "cert": <path_to_tls_cert>
 }
 ```
 The `api_key` is the raw bytes of `~/.ldk-server/<network>/api_key` hex-encoded.
 Unlike other backends, ldk-server does not require an `id` field — the node's
-public key is fetched automatically on startup.
+public key and network are fetched automatically on startup.
 
 Note: ldk-server channels are **unannounced by default**. Pass `--announce-channel`
 to `open-channel` (and set `announcement_addresses` in the ldk-server config) to
@@ -158,8 +157,7 @@ to send and receive payments when running with random activity.
     {
       "address": "localhost:3536",
       "api_key": "ldk_server_hex_encoded_api_key",
-      "cert": "/path/tls.crt",
-      "network": "signet"
+      "cert": "/path/tls.crt"
     }
   ]
 }

README.md

@@ -33,7 +33,7 @@ rand_distr = "0.4.3"
 rand_chacha = "0.3.1"
 reqwest = { version = "0.12", features = ["json", "multipart"] }
 tokio-util = { version = "0.7.13", features = ["rt"] }
-ldk-server-client = { git = "https://github.com/lightningdevkit/ldk-server", rev = "570ed527535da0ec1dae431fac3ce46e5e6a468f" }
+ldk-server-client = { git = "https://github.com/lightningdevkit/ldk-server", rev = "bf4d8bd5be283068a8988750827c858f294e8524" }
 
 [dev-dependencies]
 ntest = "0.9.0"

simln-lib/Cargo.toml

@@ -34,7 +34,6 @@ pub struct LdkConnection {
     pub api_key: String,
     #[serde(deserialize_with = "serializers::deserialize_path")]
     pub cert: String,
-    pub network: Network,
 }
 
 impl LdkNode {
@@ -62,6 +61,7 @@ impl LdkNode {
         let pubkey = PublicKey::from_str(&info.node_id)
             .map_err(|err| LightningError::GetInfoError(err.to_string()))?;
         let alias = info.node_alias.unwrap_or_default();
+        let network = network_from_proto(info.network)?;
 
         // ldk-server doesn't expose feature bits, but it always supports keysend
         // via `spontaneous_send`, so advertise it so sim-ln's keysend checks pass.
@@ -75,7 +75,7 @@ impl LdkNode {
                 features,
                 alias,
             },
-            network: connection.network,
+            network,
         })
     }
 }
@@ -247,6 +247,20 @@ impl LightningNode for LdkNode {
     }
 }
 
+/// Convert the `types.Network` proto enum (encoded as i32) returned by
+/// ldk-server's GetNodeInfo into a `bitcoin::Network`.  
+fn network_from_proto(value: i32) -> Result<Network, LightningError> {
+    match value {
+        0 => Ok(Network::Bitcoin),
+        1 => Ok(Network::Testnet),
+        3 => Ok(Network::Signet),
+        4 => Ok(Network::Regtest),
+        other => Err(LightningError::GetInfoError(format!(
+            "ldk-server returned unsupported network value: {other}"
+        ))),
+    }
+}
+
 fn string_to_payment_hash(hash: &str) -> Result<PaymentHash, LightningError> {
     let bytes = hex::decode(hash).map_err(|_| LightningError::InvalidPaymentHash)?;
     let slice: [u8; 32] = bytes