Correct async `lightning-background-processor` exit check docs
[rust-lightning] / lightning / src / onion_message / messenger.rs
index 42be0202fb110714dd0ba17dbd4482f05e072e94..ff20f19a7fc16a6bfea57e59f1b00eca27dc1d77 100644 (file)
@@ -15,26 +15,26 @@ use bitcoin::hashes::hmac::{Hmac, HmacEngine};
 use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, PublicKey, Scalar, Secp256k1, SecretKey};
 
-use chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager, Recipient, Sign};
-use ln::features::{InitFeatures, NodeFeatures};
-use ln::msgs::{self, OnionMessageHandler};
-use ln::onion_utils;
-use ln::peer_handler::IgnoringMessageHandler;
+use crate::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager, Recipient, Sign};
+use crate::ln::features::{InitFeatures, NodeFeatures};
+use crate::ln::msgs::{self, OnionMessageHandler};
+use crate::ln::onion_utils;
+use crate::ln::peer_handler::IgnoringMessageHandler;
 use super::blinded_route::{BlindedRoute, ForwardTlvs, ReceiveTlvs};
-pub use super::packet::CustomOnionMessageContents;
+pub use super::packet::{CustomOnionMessageContents, OnionMessageContents};
 use super::packet::{BIG_PACKET_HOP_DATA_LEN, ForwardControlTlvs, Packet, Payload, ReceiveControlTlvs, SMALL_PACKET_HOP_DATA_LEN};
 use super::utils;
-use util::events::OnionMessageProvider;
-use util::logger::Logger;
-use util::ser::Writeable;
+use crate::util::events::OnionMessageProvider;
+use crate::util::logger::Logger;
+use crate::util::ser::Writeable;
 
 use core::ops::Deref;
-use sync::{Arc, Mutex};
-use prelude::*;
+use crate::sync::{Arc, Mutex};
+use crate::prelude::*;
 
 /// A sender, receiver and forwarder of onion messages. In upcoming releases, this object will be
 /// used to retrieve invoices and fulfill invoice requests from [offers]. Currently, only sending
-/// and receiving empty onion messages is supported.
+/// and receiving custom onion messages is supported.
 ///
 /// # Example
 ///
@@ -45,7 +45,7 @@ use prelude::*;
 /// # use lightning::chain::keysinterface::{InMemorySigner, KeysManager, KeysInterface};
 /// # use lightning::ln::msgs::DecodeError;
 /// # use lightning::ln::peer_handler::IgnoringMessageHandler;
-/// # use lightning::onion_message::{BlindedRoute, CustomOnionMessageContents, Destination, OnionMessenger};
+/// # use lightning::onion_message::{BlindedRoute, CustomOnionMessageContents, Destination, OnionMessageContents, OnionMessenger};
 /// # use lightning::util::logger::{Logger, Record};
 /// # use lightning::util::ser::{MaybeReadableArgs, Writeable, Writer};
 /// # use lightning::io;
@@ -61,8 +61,7 @@ use prelude::*;
 /// # let node_secret = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 /// # let secp_ctx = Secp256k1::new();
 /// # let hop_node_id1 = PublicKey::from_secret_key(&secp_ctx, &node_secret);
-/// # let (hop_node_id2, hop_node_id3, hop_node_id4) = (hop_node_id1, hop_node_id1,
-/// hop_node_id1);
+/// # let (hop_node_id2, hop_node_id3, hop_node_id4) = (hop_node_id1, hop_node_id1, hop_node_id1);
 /// # let destination_node_id = hop_node_id1;
 /// # let your_custom_message_handler = IgnoringMessageHandler {};
 /// // Create the onion messenger. This must use the same `keys_manager` as is passed to your
@@ -89,19 +88,24 @@ use prelude::*;
 ///            // if the message type is unknown
 ///    }
 /// }
+/// // Send a custom onion message to a node id.
 /// let intermediate_hops = [hop_node_id1, hop_node_id2];
 /// let reply_path = None;
-/// onion_messenger.send_onion_message(&intermediate_hops, Destination::Node(destination_node_id), reply_path);
+/// # let your_custom_message = YourCustomMessage {};
+/// let message = OnionMessageContents::Custom(your_custom_message);
+/// onion_messenger.send_onion_message(&intermediate_hops, Destination::Node(destination_node_id), message, reply_path);
 ///
 /// // Create a blinded route to yourself, for someone to send an onion message to.
 /// # let your_node_id = hop_node_id1;
 /// let hops = [hop_node_id3, hop_node_id4, your_node_id];
 /// let blinded_route = BlindedRoute::new(&hops, &keys_manager, &secp_ctx).unwrap();
 ///
-/// // Send an empty onion message to a blinded route.
+/// // Send a custom onion message to a blinded route.
 /// # let intermediate_hops = [hop_node_id1, hop_node_id2];
 /// let reply_path = None;
-/// onion_messenger.send_onion_message(&intermediate_hops, Destination::BlindedRoute(blinded_route), reply_path);
+/// # let your_custom_message = YourCustomMessage {};
+/// let message = OnionMessageContents::Custom(your_custom_message);
+/// onion_messenger.send_onion_message(&intermediate_hops, Destination::BlindedRoute(blinded_route), message, reply_path);
 /// ```
 ///
 /// [offers]: <https://github.com/lightning/bolts/pull/798>
@@ -140,7 +144,7 @@ impl Destination {
 /// Errors that may occur when [sending an onion message].
 ///
 /// [sending an onion message]: OnionMessenger::send_onion_message
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum SendError {
        /// Errored computing onion message packet keys.
        Secp256k1(secp256k1::Error),
@@ -152,6 +156,8 @@ pub enum SendError {
        TooFewBlindedHops,
        /// Our next-hop peer was offline or does not support onion message forwarding.
        InvalidFirstHop,
+       /// Onion message contents must have a TLV type >= 64.
+       InvalidMessage,
        /// Our next-hop peer's buffer was full or our total outbound buffer was full.
        BufferFull,
 }
@@ -193,14 +199,17 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessenger<Signer, K, L,
                }
        }
 
-       /// Send an empty onion message to `destination`, routing it through `intermediate_nodes`.
+       /// Send an onion message with contents `message` to `destination`, routing it through `intermediate_nodes`.
        /// See [`OnionMessenger`] for example usage.
-       pub fn send_onion_message(&self, intermediate_nodes: &[PublicKey], destination: Destination, reply_path: Option<BlindedRoute>) -> Result<(), SendError> {
+       pub fn send_onion_message<T: CustomOnionMessageContents>(&self, intermediate_nodes: &[PublicKey], destination: Destination, message: OnionMessageContents<T>, reply_path: Option<BlindedRoute>) -> Result<(), SendError> {
                if let Destination::BlindedRoute(BlindedRoute { ref blinded_hops, .. }) = destination {
                        if blinded_hops.len() < 2 {
                                return Err(SendError::TooFewBlindedHops);
                        }
                }
+               let OnionMessageContents::Custom(ref msg) = message;
+               if msg.tlv_type() < 64 { return Err(SendError::InvalidMessage) }
+
                let blinding_secret_bytes = self.keys_manager.get_secure_random_bytes();
                let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");
                let (introduction_node_id, blinding_point) = if intermediate_nodes.len() != 0 {
@@ -213,7 +222,7 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessenger<Signer, K, L,
                        }
                };
                let (packet_payloads, packet_keys) = packet_payloads_and_keys(
-                       &self.secp_ctx, intermediate_nodes, destination, reply_path, &blinding_secret)
+                       &self.secp_ctx, intermediate_nodes, destination, message, reply_path, &blinding_secret)
                        .map_err(|e| SendError::Secp256k1(e))?;
 
                let prng_seed = self.keys_manager.get_secure_random_bytes();
@@ -302,12 +311,15 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessageHandler for Onion
                match onion_utils::decode_next_hop(onion_decode_ss, &msg.onion_routing_packet.hop_data[..],
                        msg.onion_routing_packet.hmac, control_tlvs_ss)
                {
-                       Ok((Payload::Receive {
-                               control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id }), reply_path,
+                       Ok((Payload::Receive::<<<CMH as Deref>::Target as CustomOnionMessageHandler>::CustomMessage> {
+                               message, control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id }), reply_path,
                        }, None)) => {
                                log_info!(self.logger,
-                                       "Received an onion message with path_id: {:02x?} and {}reply_path",
-                                               path_id, if reply_path.is_some() { "" } else { "no " });
+                                       "Received an onion message with path_id {:02x?} and {} reply_path",
+                                               path_id, if reply_path.is_some() { "a" } else { "no" });
+                               match message {
+                                       OnionMessageContents::Custom(msg) => self.custom_handler.handle_custom_message(msg),
+                               }
                        },
                        Ok((Payload::Forward(ForwardControlTlvs::Unblinded(ForwardTlvs {
                                next_node_id, next_blinding_override
@@ -443,10 +455,10 @@ pub type SimpleRefOnionMessenger<'a, 'b, L> = OnionMessenger<InMemorySigner, &'a
 
 /// Construct onion packet payloads and keys for sending an onion message along the given
 /// `unblinded_path` to the given `destination`.
-fn packet_payloads_and_keys<T: secp256k1::Signing + secp256k1::Verification>(
-       secp_ctx: &Secp256k1<T>, unblinded_path: &[PublicKey], destination: Destination, mut reply_path:
-       Option<BlindedRoute>, session_priv: &SecretKey
-) -> Result<(Vec<(Payload, [u8; 32])>, Vec<onion_utils::OnionKeys>), secp256k1::Error> {
+fn packet_payloads_and_keys<T: CustomOnionMessageContents, S: secp256k1::Signing + secp256k1::Verification>(
+       secp_ctx: &Secp256k1<S>, unblinded_path: &[PublicKey], destination: Destination,
+       message: OnionMessageContents<T>, mut reply_path: Option<BlindedRoute>, session_priv: &SecretKey
+) -> Result<(Vec<(Payload<T>, [u8; 32])>, Vec<onion_utils::OnionKeys>), secp256k1::Error> {
        let num_hops = unblinded_path.len() + destination.num_hops();
        let mut payloads = Vec::with_capacity(num_hops);
        let mut onion_packet_keys = Vec::with_capacity(num_hops);
@@ -459,6 +471,7 @@ fn packet_payloads_and_keys<T: secp256k1::Signing + secp256k1::Verification>(
        let mut unblinded_path_idx = 0;
        let mut blinded_path_idx = 0;
        let mut prev_control_tlvs_ss = None;
+       let mut final_control_tlvs = None;
        utils::construct_keys_callback(secp_ctx, unblinded_path, Some(destination), session_priv, |_, onion_packet_ss, ephemeral_pubkey, control_tlvs_ss, unblinded_pk_opt, enc_payload_opt| {
                if num_unblinded_hops != 0 && unblinded_path_idx < num_unblinded_hops {
                        if let Some(ss) = prev_control_tlvs_ss.take() {
@@ -488,10 +501,8 @@ fn packet_payloads_and_keys<T: secp256k1::Signing + secp256k1::Verification>(
                                control_tlvs_ss));
                        blinded_path_idx += 1;
                } else if let Some(encrypted_payload) = enc_payload_opt {
-                       payloads.push((Payload::Receive {
-                               control_tlvs: ReceiveControlTlvs::Blinded(encrypted_payload),
-                               reply_path: reply_path.take(),
-                       }, control_tlvs_ss));
+                       final_control_tlvs = Some(ReceiveControlTlvs::Blinded(encrypted_payload));
+                       prev_control_tlvs_ss = Some(control_tlvs_ss);
                }
 
                let (rho, mu) = onion_utils::gen_rho_mu_from_shared_secret(onion_packet_ss.as_ref());
@@ -506,18 +517,25 @@ fn packet_payloads_and_keys<T: secp256k1::Signing + secp256k1::Verification>(
                });
        })?;
 
-       if let Some(control_tlvs_ss) = prev_control_tlvs_ss {
+       if let Some(control_tlvs) = final_control_tlvs {
+               payloads.push((Payload::Receive {
+                       control_tlvs,
+                       reply_path: reply_path.take(),
+                       message,
+               }, prev_control_tlvs_ss.unwrap()));
+       } else {
                payloads.push((Payload::Receive {
                        control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id: None, }),
                        reply_path: reply_path.take(),
-               }, control_tlvs_ss));
+                       message,
+               }, prev_control_tlvs_ss.unwrap()));
        }
 
        Ok((payloads, onion_packet_keys))
 }
 
 /// Errors if the serialized payload size exceeds onion_message::BIG_PACKET_HOP_DATA_LEN
-fn construct_onion_message_packet(payloads: Vec<(Payload, [u8; 32])>, onion_keys: Vec<onion_utils::OnionKeys>, prng_seed: [u8; 32]) -> Result<Packet, ()> {
+fn construct_onion_message_packet<T: CustomOnionMessageContents>(payloads: Vec<(Payload<T>, [u8; 32])>, onion_keys: Vec<onion_utils::OnionKeys>, prng_seed: [u8; 32]) -> Result<Packet, ()> {
        // Spec rationale:
        // "`len` allows larger messages to be sent than the standard 1300 bytes allowed for an HTLC
        // onion, but this should be used sparingly as it is reduces anonymity set, hence the