// This example connects to LND and uses router rpc to intercept htlcs, inspect the details, then resume forwarding them
//
// The program accepts three arguments: address, cert file, macaroon file
// The address must start with `https://`!
//
// Example run: `cargo run --features=routerrpc --example intercept_htlcs
`
#[tokio::main]
#[cfg(feature = "routerrpc")]
async fn main() {
let mut args = std::env::args_os();
args.next().expect("not even zeroth arg given");
let address: String = args
.next()
.expect("missing arguments: address, macaroon file, payment hash")
.into_string()
.expect("address is not UTF-8");
let cert_file: String = args
.next()
.expect("missing arguments: cert file, macaroon file")
.into_string()
.expect("cert_file is not UTF-8");
let macaroon_file: String = args
.next()
.expect("missing argument: macaroon file")
.into_string()
.expect("macaroon_file is not UTF-8");
// Connecting to LND requires only address, cert file, and macaroon file
let mut client = fedimint_tonic_lnd::connect(address, cert_file, macaroon_file)
.await
.expect("failed to connect");
let (tx, rx) = tokio::sync::mpsc::channel::<
fedimint_tonic_lnd::routerrpc::ForwardHtlcInterceptResponse,
>(1024);
let stream = tokio_stream::wrappers::ReceiverStream::new(rx);
let mut htlc_stream = client
.router()
.htlc_interceptor(stream)
.await
.expect("Failed to call subscribe_invoices")
.into_inner();
while let Some(htlc) = htlc_stream
.message()
.await
.expect("Failed to receive invoices")
{
println!("HTLC Intercepted------------");
println!(
"incoming_circuit_key: {:?}\nincoming_amount_msat: {}\noutgoing_amount_msat: {}\npayment_hash: {:?}\n",
htlc.incoming_circuit_key, htlc.incoming_amount_msat, htlc.outgoing_amount_msat, htlc.payment_hash
);
let response = fedimint_tonic_lnd::routerrpc::ForwardHtlcInterceptResponse {
incoming_circuit_key: htlc.incoming_circuit_key,
action: 2, // Resume fordwarding of intercepted HTLC
preimage: vec![],
failure_message: vec![],
failure_code: 0,
};
tx.send(response).await.unwrap();
}
}