offers: wait for invoice to be returned

Cargo.toml

@@ -24,6 +24,7 @@ rand_core = "0.6.4"
 log = "0.4.17"
 log4rs = { version = "1.2.0", features = ["file_appender"] }
 tokio = { version = "1.25.0", features = ["rt", "rt-multi-thread"] }
+tokio-stream = { version = "0.1.14" }
 tonic = "0.8.3"
 tonic_lnd = { git = "https://github.com/orbitalturtle/tonic_lnd", branch = "update-signer-client" }
 hex = "0.4.3"
@@ -34,7 +35,7 @@ bytes = "1.4.0"
 bitcoincore-rpc = { package="core-rpc", version = "0.17.0" }
 bitcoind = { version = "0.30.0", features = [ "22_0" ] }
 chrono = { version = "0.4.26" }
-ldk-sample = { git = "https://github.com/lndk-org/ldk-sample", branch = "offers" }
+ldk-sample = { git = "https://github.com/lndk-org/ldk-sample", branch = "offer-handling" }
 mockall = "0.11.3"
 tempfile = "3.5.0"
 

src/lndk_offers.rs

@@ -10,7 +10,7 @@ use core::ops::Deref;
 use futures::executor::block_on;
 use lightning::blinded_path::BlindedPath;
 use lightning::ln::features::InitFeatures;
-use lightning::ln::msgs::{Init, OnionMessageHandler};
+use lightning::ln::msgs::{Init, OnionMessage, OnionMessageHandler};
 use lightning::offers::invoice_request::{InvoiceRequest, UnsignedInvoiceRequest};
 use lightning::offers::merkle::SignError;
 use lightning::offers::offer::Offer;
@@ -22,9 +22,12 @@ use lightning::onion_message::{
 use lightning::sign::EntropySource;
 use lightning::sign::NodeSigner;
 use lightning::util::logger::Logger;
+use lightning::util::ser::Readable;
 use std::error::Error;
 use std::fmt::Display;
+use std::io::Cursor;
 use tokio::task;
+use tokio_stream::StreamExt;
 use tonic_lnd::signrpc::{KeyLocator, SignMessageReq};
 use tonic_lnd::tonic::Status;
 use tonic_lnd::Client;
@@ -40,6 +43,8 @@ pub enum OfferError<Secp256k1Error> {
     DeriveKeyFailure(Status),
     /// Trouble sending an offers-related onion message along.
     SendError(SendError),
+    /// GetInvoiceError Indicates a failure to receive an invoice.
+    GetInvoiceError,
 }
 
 impl Display for OfferError<Secp256k1Error> {
@@ -49,6 +54,7 @@ impl Display for OfferError<Secp256k1Error> {
             OfferError::SignError(e) => write!(f, "Error signing invoice request: {e:?}"),
             OfferError::DeriveKeyFailure(e) => write!(f, "Error signing invoice request: {e:?}"),
             OfferError::SendError(e) => write!(f, "Error sending onion message: {e:?}"),
+            OfferError::GetInvoiceError => write!(f, "Error retrieving invoice"),
         }
     }
 }
@@ -198,6 +204,32 @@ pub async fn send_invoice_request<OMH: OnionMessageHandler + SendOnion>(
         &mut custom_msg_client,
     )
     .await;
+
+    Ok(())
+}
+
+// After we've requested an invoice from the offer maker, wait for them to send us back an invoice.
+pub async fn wait_for_invoice<OMH: OnionMessageHandler + SendOnion>(
+    ln_client: &mut tonic_lnd::LightningClient,
+    onion_messenger: &OMH,
+) -> Result<(), OfferError<Secp256k1Error>> {
+    let message_stream = ln_client
+        .subscribe_custom_messages(tonic_lnd::lnrpc::SubscribeCustomMessagesRequest {})
+        .await
+        .expect("message subscription failed")
+        .into_inner();
+
+    let mut message_stream = message_stream.take(1);
+    if let Some(msg) = message_stream.next().await {
+        let message = msg.unwrap();
+        if let Ok(onion_msg) = <OnionMessage as Readable>::read(&mut Cursor::new(message.data)) {
+            let pubkey = PublicKey::from_slice(&message.peer).unwrap();
+            onion_messenger.handle_onion_message(&pubkey, &onion_msg);
+            return Ok(());
+        } else {
+            return Err(OfferError::GetInvoiceError);
+        }
+    }
     Ok(())
 }
 

tests/common/test_utils.rs

@@ -19,11 +19,11 @@ where
     while retry_num < 3 {
         sleep(Duration::from_secs(3)).await;
         match f().await {
-            Err(_) => {
+            Err(e) => {
                 println!("retrying {} call", func_name.clone());
                 retry_num += 1;
                 if retry_num == 5 {
-                    panic!("{} call failed after 3 retries", func_name);
+                    panic!("{} call failed after 3 retries: {:?}", func_name, e);
                 }
                 continue;
             }

tests/integration_tests.rs

@@ -3,21 +3,24 @@ use lndk;
 
 use bitcoin::secp256k1::{PublicKey, Secp256k1};
 use bitcoin::Network;
+use bitcoincore_rpc::bitcoin::Network as RpcNetwork;
+use bitcoincore_rpc::RpcApi;
 use ldk_sample::node_api::Node as LdkNode;
 use lightning::blinded_path::BlindedPath;
 use lightning::ln::peer_handler::IgnoringMessageHandler;
 use lightning::offers::offer::Quantity;
 use lightning::onion_message::{DefaultMessageRouter, OnionMessenger};
 use lndk::lnd::LndNodeSigner;
-use lndk::lndk_offers::request_invoice;
+use lndk::lndk_offers::{request_invoice, wait_for_invoice};
 use lndk::onion_messenger::{CustomMessenger, InvoiceHandler, MessengerUtilities};
 use std::collections::VecDeque;
+use std::net::SocketAddr;
 use std::path::PathBuf;
 use std::str::FromStr;
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, SystemTime};
-use tokio::select;
 use tokio::time::{sleep, timeout, Duration as TokioDuration};
+use tokio::{join, select};
 
 async fn wait_to_receive_onion_message(
     ldk1: LdkNode,
@@ -185,3 +188,147 @@ async fn test_lndk_send_invoice_request() {
         }
     }
 }
+
+#[tokio::test(flavor = "multi_thread")]
+// Here we test that when the offer creator responds with an invoice, lndk is able to receive it.
+async fn test_lndk_wait_for_invoice() {
+    let test_name = "lndk_wait_for_invoice";
+    let (bitcoind, mut lnd, ldk1, ldk2, _lndk_dir) =
+        common::setup_test_infrastructure(test_name).await;
+
+    // Here we'll produce a little network of channels:
+    //
+    // ldk1 <- ldk2 <- lnd
+    //
+    // ldk1 will be the offer creator, which will build a blinded route from ldk2 to ldk1.
+    let (pubkey, addr) = ldk1.get_node_info();
+    let (pubkey_2, addr_2) = ldk2.get_node_info();
+
+    ldk1.connect_to_peer(pubkey_2, addr_2).await.unwrap();
+    lnd.connect_to_peer(pubkey_2, addr_2).await;
+
+    let lnd_info = lnd.get_info().await;
+    let lnd_pubkey = PublicKey::from_str(&lnd_info.identity_pubkey).unwrap();
+
+    // ldk1 won't send back the invoice unless we have channels in our network.
+    let ldk2_fund_addr = ldk2.bitcoind_client.get_new_address().await;
+    let lnd_fund_addr = lnd.new_address().await.address;
+
+    // We need to convert funding addresses to the form that the bitcoincore_rpc library recognizes.
+    let ldk2_addr_string = ldk2_fund_addr.to_string();
+    let ldk2_addr = bitcoincore_rpc::bitcoin::Address::from_str(&ldk2_addr_string)
+        .unwrap()
+        .require_network(RpcNetwork::Regtest)
+        .unwrap();
+    let lnd_addr = bitcoincore_rpc::bitcoin::Address::from_str(&lnd_fund_addr)
+        .unwrap()
+        .require_network(RpcNetwork::Regtest)
+        .unwrap();
+    let lnd_network_addr = lnd
+        .address
+        .replace("localhost", "127.0.0.1")
+        .replace("https://", "");
+
+    // Fund both of these nodes so we can open channels.
+    bitcoind
+        .node
+        .client
+        .generate_to_address(1, &ldk2_addr)
+        .unwrap();
+    bitcoind
+        .node
+        .client
+        .generate_to_address(1, &lnd_addr)
+        .unwrap();
+
+    // Make sure the above funds are confirmed.
+    bitcoind
+        .node
+        .client
+        .generate_to_address(100, &ldk2_addr)
+        .unwrap();
+
+    ldk2.open_channel(pubkey, addr, 200000, 0, true)
+        .await
+        .unwrap();
+    ldk2.open_channel(
+        lnd_pubkey,
+        SocketAddr::from_str(&lnd_network_addr).unwrap(),
+        200000,
+        100000,
+        false,
+    )
+    .await
+    .unwrap();
+
+    bitcoind
+        .node
+        .client
+        .generate_to_address(100, &ldk2_addr)
+        .unwrap();
+
+    // TODO: Restarting the lnd node here isn't ideal. But for some reason after we call LDK's open_channel
+    // API call, LND blocks and is unable to receive any API requests. This might be a bug in ldk-sample or
+    // our ldk-sample implementation.
+    lnd.handle.kill().expect("lnd couldn't be killed");
+    lnd.start().await;
+    lnd.connect_to_peer(pubkey_2, addr_2).await;
+
+    let path_pubkeys = vec![pubkey_2, pubkey];
+    let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
+    let offer = ldk1
+        .create_offer(
+            &path_pubkeys,
+            Network::Regtest,
+            20_000,
+            Quantity::One,
+            expiration,
+        )
+        .await
+        .expect("should create offer");
+
+    let mut signer_clone = lnd.client.clone().unwrap();
+    let signer_client = signer_clone.signer();
+    let node_signer = LndNodeSigner::new(lnd_pubkey.clone(), signer_client);
+    let messenger_utils = MessengerUtilities::new();
+    let mut invoice_handler = InvoiceHandler {
+        invoices: Arc::new(Mutex::new(VecDeque::new())),
+    };
+    let onion_messenger = OnionMessenger::new(
+        &messenger_utils,
+        &node_signer,
+        &messenger_utils,
+        &DefaultMessageRouter {},
+        &mut invoice_handler,
+        IgnoringMessageHandler {},
+    );
+
+    let client = lnd.client.clone().unwrap();
+    let mut client_clone = lnd.client.clone().unwrap();
+    let custom_msg_client = CustomMessenger {
+        client: client_clone.lightning().to_owned(),
+    };
+    let blinded_path = offer.paths()[0].clone();
+    let secp_ctx = Secp256k1::new();
+    let reply_path =
+        BlindedPath::new_for_message(&[pubkey_2, lnd_pubkey], &messenger_utils, &secp_ctx).unwrap();
+
+    let (res1, res2) = join!(
+        wait_for_invoice(client_clone.lightning(), &onion_messenger),
+        request_invoice(
+            client.clone(),
+            &onion_messenger,
+            custom_msg_client,
+            offer,
+            pubkey_2,
+            reply_path,
+            blinded_path
+        )
+    );
+    res1.unwrap();
+    res2.unwrap();
+
+    // LND should have received the Bolt12Invoice.
+    let invoices = invoice_handler.invoices.lock().unwrap();
+    assert!(invoices.len() == 1);
+}