Implement EntropySource for InMemorySigner

[rust-lightning] / lightning / src / ln / msgs.rs

// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! Wire messages, traits representing wire message handlers, and a few error types live here.
//!
//! For a normal node you probably don't need to use anything here, however, if you wish to split a
//! node into an internet-facing route/message socket handling daemon and a separate daemon (or
//! server entirely) which handles only channel-related messages you may wish to implement
//! [`ChannelMessageHandler`] yourself and use it to re-serialize messages and pass them across
//! daemons/servers.
//!
//! Note that if you go with such an architecture (instead of passing raw socket events to a
//! non-internet-facing system) you trust the frontend internet-facing system to not lie about the
//! source `node_id` of the message, however this does allow you to significantly reduce bandwidth
//! between the systems as routing messages can represent a significant chunk of bandwidth usage
//! (especially for non-channel-publicly-announcing nodes). As an alternate design which avoids
//! this issue, if you have sufficient bidirectional bandwidth between your systems, you may send
//! raw socket events into your non-internet-facing system and then send routing events back to
//! track the network on the less-secure system.

use bitcoin::secp256k1::PublicKey;
use bitcoin::secp256k1::ecdsa::Signature;
use bitcoin::secp256k1;
use bitcoin::blockdata::script::Script;
use bitcoin::hash_types::{Txid, BlockHash};

use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
use crate::ln::onion_utils;
use crate::onion_message;

use crate::prelude::*;
use core::fmt;
use core::fmt::Debug;
use crate::io::{self, Read};
use crate::io_extras::read_to_end;

use crate::events::{MessageSendEventsProvider, OnionMessageProvider};
use crate::util::logger;
use crate::util::ser::{LengthReadable, Readable, ReadableArgs, Writeable, Writer, WithoutLength, FixedLengthReader, HighZeroBytesDroppedBigSize, Hostname};

use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};

use crate::routing::gossip::{NodeAlias, NodeId};

/// 21 million * 10^8 * 1000
pub(crate) const MAX_VALUE_MSAT: u64 = 21_000_000_0000_0000_000;

#[cfg(taproot)]
/// A partial signature that also contains the Musig2 nonce its signer used
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct PartialSignatureWithNonce(pub musig2::types::PartialSignature, pub musig2::types::PublicNonce);

/// An error in decoding a message or struct.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum DecodeError {
        /// A version byte specified something we don't know how to handle.
        ///
        /// Includes unknown realm byte in an onion hop data packet.
        UnknownVersion,
        /// Unknown feature mandating we fail to parse message (e.g., TLV with an even, unknown type)
        UnknownRequiredFeature,
        /// Value was invalid.
        ///
        /// For example, a byte which was supposed to be a bool was something other than a 0
        /// or 1, a public key/private key/signature was invalid, text wasn't UTF-8, TLV was
        /// syntactically incorrect, etc.
        InvalidValue,
        /// The buffer to be read was too short.
        ShortRead,
        /// A length descriptor in the packet didn't describe the later data correctly.
        BadLengthDescriptor,
        /// Error from [`std::io`].
        Io(io::ErrorKind),
        /// The message included zlib-compressed values, which we don't support.
        UnsupportedCompression,
}

/// An [`init`] message to be sent to or received from a peer.
///
/// [`init`]: https://github.com/lightning/bolts/blob/master/01-messaging.md#the-init-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Init {
        /// The relevant features which the sender supports.
        pub features: InitFeatures,
        /// The receipient's network address.
        ///
        /// This adds the option to report a remote IP address back to a connecting peer using the init
        /// message. A node can decide to use that information to discover a potential update to its
        /// public IPv4 address (NAT) and use that for a [`NodeAnnouncement`] update message containing
        /// the new address.
        pub remote_network_address: Option<NetAddress>,
}

/// An [`error`] message to be sent to or received from a peer.
///
/// [`error`]: https://github.com/lightning/bolts/blob/master/01-messaging.md#the-error-and-warning-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ErrorMessage {
        /// The channel ID involved in the error.
        ///
        /// All-0s indicates a general error unrelated to a specific channel, after which all channels
        /// with the sending peer should be closed.
        pub channel_id: [u8; 32],
        /// A possibly human-readable error description.
        ///
        /// The string should be sanitized before it is used (e.g., emitted to logs or printed to
        /// `stdout`). Otherwise, a well crafted error message may trigger a security vulnerability in
        /// the terminal emulator or the logging subsystem.
        pub data: String,
}

/// A [`warning`] message to be sent to or received from a peer.
///
/// [`warning`]: https://github.com/lightning/bolts/blob/master/01-messaging.md#the-error-and-warning-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct WarningMessage {
        /// The channel ID involved in the warning.
        ///
        /// All-0s indicates a warning unrelated to a specific channel.
        pub channel_id: [u8; 32],
        /// A possibly human-readable warning description.
        ///
        /// The string should be sanitized before it is used (e.g. emitted to logs or printed to
        /// stdout). Otherwise, a well crafted error message may trigger a security vulnerability in
        /// the terminal emulator or the logging subsystem.
        pub data: String,
}

/// A [`ping`] message to be sent to or received from a peer.
///
/// [`ping`]: https://github.com/lightning/bolts/blob/master/01-messaging.md#the-ping-and-pong-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Ping {
        /// The desired response length.
        pub ponglen: u16,
        /// The ping packet size.
        ///
        /// This field is not sent on the wire. byteslen zeros are sent.
        pub byteslen: u16,
}

/// A [`pong`] message to be sent to or received from a peer.
///
/// [`pong`]: https://github.com/lightning/bolts/blob/master/01-messaging.md#the-ping-and-pong-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Pong {
        /// The pong packet size.
        ///
        /// This field is not sent on the wire. byteslen zeros are sent.
        pub byteslen: u16,
}

/// An [`open_channel`] message to be sent to or received from a peer.
///
/// [`open_channel`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct OpenChannel {
        /// The genesis hash of the blockchain where the channel is to be opened
        pub chain_hash: BlockHash,
        /// A temporary channel ID, until the funding outpoint is announced
        pub temporary_channel_id: [u8; 32],
        /// The channel value
        pub funding_satoshis: u64,
        /// The amount to push to the counterparty as part of the open, in milli-satoshi
        pub push_msat: u64,
        /// The threshold below which outputs on transactions broadcast by sender will be omitted
        pub dust_limit_satoshis: u64,
        /// The maximum inbound HTLC value in flight towards sender, in milli-satoshi
        pub max_htlc_value_in_flight_msat: u64,
        /// The minimum value unencumbered by HTLCs for the counterparty to keep in the channel
        pub channel_reserve_satoshis: u64,
        /// The minimum HTLC size incoming to sender, in milli-satoshi
        pub htlc_minimum_msat: u64,
        /// The feerate per 1000-weight of sender generated transactions, until updated by
        /// [`UpdateFee`]
        pub feerate_per_kw: u32,
        /// The number of blocks which the counterparty will have to wait to claim on-chain funds if
        /// they broadcast a commitment transaction
        pub to_self_delay: u16,
        /// The maximum number of inbound HTLCs towards sender
        pub max_accepted_htlcs: u16,
        /// The sender's key controlling the funding transaction
        pub funding_pubkey: PublicKey,
        /// Used to derive a revocation key for transactions broadcast by counterparty
        pub revocation_basepoint: PublicKey,
        /// A payment key to sender for transactions broadcast by counterparty
        pub payment_point: PublicKey,
        /// Used to derive a payment key to sender for transactions broadcast by sender
        pub delayed_payment_basepoint: PublicKey,
        /// Used to derive an HTLC payment key to sender
        pub htlc_basepoint: PublicKey,
        /// The first to-be-broadcast-by-sender transaction's per commitment point
        pub first_per_commitment_point: PublicKey,
        /// The channel flags to be used
        pub channel_flags: u8,
        /// Optionally, a request to pre-set the to-sender output's `scriptPubkey` for when we collaboratively close
        pub shutdown_scriptpubkey: OptionalField<Script>,
        /// The channel type that this channel will represent
        ///
        /// If this is `None`, we derive the channel type from the intersection of our
        /// feature bits with our counterparty's feature bits from the [`Init`] message.
        pub channel_type: Option<ChannelTypeFeatures>,
}

/// An [`accept_channel`] message to be sent to or received from a peer.
///
/// [`accept_channel`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-accept_channel-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct AcceptChannel {
        /// A temporary channel ID, until the funding outpoint is announced
        pub temporary_channel_id: [u8; 32],
        /// The threshold below which outputs on transactions broadcast by sender will be omitted
        pub dust_limit_satoshis: u64,
        /// The maximum inbound HTLC value in flight towards sender, in milli-satoshi
        pub max_htlc_value_in_flight_msat: u64,
        /// The minimum value unencumbered by HTLCs for the counterparty to keep in the channel
        pub channel_reserve_satoshis: u64,
        /// The minimum HTLC size incoming to sender, in milli-satoshi
        pub htlc_minimum_msat: u64,
        /// Minimum depth of the funding transaction before the channel is considered open
        pub minimum_depth: u32,
        /// The number of blocks which the counterparty will have to wait to claim on-chain funds if they broadcast a commitment transaction
        pub to_self_delay: u16,
        /// The maximum number of inbound HTLCs towards sender
        pub max_accepted_htlcs: u16,
        /// The sender's key controlling the funding transaction
        pub funding_pubkey: PublicKey,
        /// Used to derive a revocation key for transactions broadcast by counterparty
        pub revocation_basepoint: PublicKey,
        /// A payment key to sender for transactions broadcast by counterparty
        pub payment_point: PublicKey,
        /// Used to derive a payment key to sender for transactions broadcast by sender
        pub delayed_payment_basepoint: PublicKey,
        /// Used to derive an HTLC payment key to sender for transactions broadcast by counterparty
        pub htlc_basepoint: PublicKey,
        /// The first to-be-broadcast-by-sender transaction's per commitment point
        pub first_per_commitment_point: PublicKey,
        /// Optionally, a request to pre-set the to-sender output's scriptPubkey for when we collaboratively close
        pub shutdown_scriptpubkey: OptionalField<Script>,
        /// The channel type that this channel will represent.
        ///
        /// If this is `None`, we derive the channel type from the intersection of
        /// our feature bits with our counterparty's feature bits from the [`Init`] message.
        /// This is required to match the equivalent field in [`OpenChannel::channel_type`].
        pub channel_type: Option<ChannelTypeFeatures>,
        #[cfg(taproot)]
        /// Next nonce the channel initiator should use to create a funding output signature against
        pub next_local_nonce: Option<musig2::types::PublicNonce>,
}

/// A [`funding_created`] message to be sent to or received from a peer.
///
/// [`funding_created`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-funding_created-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct FundingCreated {
        /// A temporary channel ID, until the funding is established
        pub temporary_channel_id: [u8; 32],
        /// The funding transaction ID
        pub funding_txid: Txid,
        /// The specific output index funding this channel
        pub funding_output_index: u16,
        /// The signature of the channel initiator (funder) on the initial commitment transaction
        pub signature: Signature,
        #[cfg(taproot)]
        /// The partial signature of the channel initiator (funder)
        pub partial_signature_with_nonce: Option<PartialSignatureWithNonce>,
        #[cfg(taproot)]
        /// Next nonce the channel acceptor should use to finalize the funding output signature
        pub next_local_nonce: Option<musig2::types::PublicNonce>
}

/// A [`funding_signed`] message to be sent to or received from a peer.
///
/// [`funding_signed`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-funding_signed-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct FundingSigned {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The signature of the channel acceptor (fundee) on the initial commitment transaction
        pub signature: Signature,
        #[cfg(taproot)]
        /// The partial signature of the channel acceptor (fundee)
        pub partial_signature_with_nonce: Option<PartialSignatureWithNonce>,
}

/// A [`channel_ready`] message to be sent to or received from a peer.
///
/// [`channel_ready`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-channel_ready-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ChannelReady {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The per-commitment point of the second commitment transaction
        pub next_per_commitment_point: PublicKey,
        /// If set, provides a `short_channel_id` alias for this channel.
        ///
        /// The sender will accept payments to be forwarded over this SCID and forward them to this
        /// messages' recipient.
        pub short_channel_id_alias: Option<u64>,
}

/// A [`shutdown`] message to be sent to or received from a peer.
///
/// [`shutdown`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#closing-initiation-shutdown
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Shutdown {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The destination of this peer's funds on closing.
        ///
        /// Must be in one of these forms: P2PKH, P2SH, P2WPKH, P2WSH, P2TR.
        pub scriptpubkey: Script,
}

/// The minimum and maximum fees which the sender is willing to place on the closing transaction.
///
/// This is provided in [`ClosingSigned`] by both sides to indicate the fee range they are willing
/// to use.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ClosingSignedFeeRange {
        /// The minimum absolute fee, in satoshis, which the sender is willing to place on the closing
        /// transaction.
        pub min_fee_satoshis: u64,
        /// The maximum absolute fee, in satoshis, which the sender is willing to place on the closing
        /// transaction.
        pub max_fee_satoshis: u64,
}

/// A [`closing_signed`] message to be sent to or received from a peer.
///
/// [`closing_signed`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#closing-negotiation-closing_signed
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ClosingSigned {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The proposed total fee for the closing transaction
        pub fee_satoshis: u64,
        /// A signature on the closing transaction
        pub signature: Signature,
        /// The minimum and maximum fees which the sender is willing to accept, provided only by new
        /// nodes.
        pub fee_range: Option<ClosingSignedFeeRange>,
}

/// An [`update_add_htlc`] message to be sent to or received from a peer.
///
/// [`update_add_htlc`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#adding-an-htlc-update_add_htlc
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UpdateAddHTLC {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The HTLC ID
        pub htlc_id: u64,
        /// The HTLC value in milli-satoshi
        pub amount_msat: u64,
        /// The payment hash, the pre-image of which controls HTLC redemption
        pub payment_hash: PaymentHash,
        /// The expiry height of the HTLC
        pub cltv_expiry: u32,
        pub(crate) onion_routing_packet: OnionPacket,
}

 /// An onion message to be sent to or received from a peer.
 ///
 // TODO: update with link to OM when they are merged into the BOLTs
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct OnionMessage {
        /// Used in decrypting the onion packet's payload.
        pub blinding_point: PublicKey,
        pub(crate) onion_routing_packet: onion_message::Packet,
}

/// An [`update_fulfill_htlc`] message to be sent to or received from a peer.
///
/// [`update_fulfill_htlc`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#removing-an-htlc-update_fulfill_htlc-update_fail_htlc-and-update_fail_malformed_htlc
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UpdateFulfillHTLC {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The HTLC ID
        pub htlc_id: u64,
        /// The pre-image of the payment hash, allowing HTLC redemption
        pub payment_preimage: PaymentPreimage,
}

/// An [`update_fail_htlc`] message to be sent to or received from a peer.
///
/// [`update_fail_htlc`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#removing-an-htlc-update_fulfill_htlc-update_fail_htlc-and-update_fail_malformed_htlc
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UpdateFailHTLC {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The HTLC ID
        pub htlc_id: u64,
        pub(crate) reason: OnionErrorPacket,
}

/// An [`update_fail_malformed_htlc`] message to be sent to or received from a peer.
///
/// [`update_fail_malformed_htlc`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#removing-an-htlc-update_fulfill_htlc-update_fail_htlc-and-update_fail_malformed_htlc
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UpdateFailMalformedHTLC {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The HTLC ID
        pub htlc_id: u64,
        pub(crate) sha256_of_onion: [u8; 32],
        /// The failure code
        pub failure_code: u16,
}

/// A [`commitment_signed`] message to be sent to or received from a peer.
///
/// [`commitment_signed`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#committing-updates-so-far-commitment_signed
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct CommitmentSigned {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// A signature on the commitment transaction
        pub signature: Signature,
        /// Signatures on the HTLC transactions
        pub htlc_signatures: Vec<Signature>,
        #[cfg(taproot)]
        /// The partial Taproot signature on the commitment transaction
        pub partial_signature_with_nonce: Option<PartialSignatureWithNonce>,
}

/// A [`revoke_and_ack`] message to be sent to or received from a peer.
///
/// [`revoke_and_ack`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#completing-the-transition-to-the-updated-state-revoke_and_ack
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct RevokeAndACK {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The secret corresponding to the per-commitment point
        pub per_commitment_secret: [u8; 32],
        /// The next sender-broadcast commitment transaction's per-commitment point
        pub next_per_commitment_point: PublicKey,
        #[cfg(taproot)]
        /// Musig nonce the recipient should use in their next commitment signature message
        pub next_local_nonce: Option<musig2::types::PublicNonce>
}

/// An [`update_fee`] message to be sent to or received from a peer
///
/// [`update_fee`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#updating-fees-update_fee
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UpdateFee {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// Fee rate per 1000-weight of the transaction
        pub feerate_per_kw: u32,
}

#[derive(Clone, Debug, PartialEq, Eq)]
/// Proof that the sender knows the per-commitment secret of the previous commitment transaction.
///
/// This is used to convince the recipient that the channel is at a certain commitment
/// number even if they lost that data due to a local failure. Of course, the peer may lie
/// and even later commitments may have been revoked.
pub struct DataLossProtect {
        /// Proof that the sender knows the per-commitment secret of a specific commitment transaction
        /// belonging to the recipient
        pub your_last_per_commitment_secret: [u8; 32],
        /// The sender's per-commitment point for their current commitment transaction
        pub my_current_per_commitment_point: PublicKey,
}

/// A [`channel_reestablish`] message to be sent to or received from a peer.
///
/// [`channel_reestablish`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#message-retransmission
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ChannelReestablish {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The next commitment number for the sender
        pub next_local_commitment_number: u64,
        /// The next commitment number for the recipient
        pub next_remote_commitment_number: u64,
        /// Optionally, a field proving that next_remote_commitment_number-1 has been revoked
        pub data_loss_protect: OptionalField<DataLossProtect>,
}

/// An [`announcement_signatures`] message to be sent to or received from a peer.
///
/// [`announcement_signatures`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-announcement_signatures-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct AnnouncementSignatures {
        /// The channel ID
        pub channel_id: [u8; 32],
        /// The short channel ID
        pub short_channel_id: u64,
        /// A signature by the node key
        pub node_signature: Signature,
        /// A signature by the funding key
        pub bitcoin_signature: Signature,
}

/// An address which can be used to connect to a remote peer.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum NetAddress {
        /// An IPv4 address/port on which the peer is listening.
        IPv4 {
                /// The 4-byte IPv4 address
                addr: [u8; 4],
                /// The port on which the node is listening
                port: u16,
        },
        /// An IPv6 address/port on which the peer is listening.
        IPv6 {
                /// The 16-byte IPv6 address
                addr: [u8; 16],
                /// The port on which the node is listening
                port: u16,
        },
        /// An old-style Tor onion address/port on which the peer is listening.
        ///
        /// This field is deprecated and the Tor network generally no longer supports V2 Onion
        /// addresses. Thus, the details are not parsed here.
        OnionV2([u8; 12]),
        /// A new-style Tor onion address/port on which the peer is listening.
        ///
        /// To create the human-readable "hostname", concatenate the ED25519 pubkey, checksum, and version,
        /// wrap as base32 and append ".onion".
        OnionV3 {
                /// The ed25519 long-term public key of the peer
                ed25519_pubkey: [u8; 32],
                /// The checksum of the pubkey and version, as included in the onion address
                checksum: u16,
                /// The version byte, as defined by the Tor Onion v3 spec.
                version: u8,
                /// The port on which the node is listening
                port: u16,
        },
        /// A hostname/port on which the peer is listening.
        Hostname {
                /// The hostname on which the node is listening.
                hostname: Hostname,
                /// The port on which the node is listening.
                port: u16,
        },
}
impl NetAddress {
        /// Gets the ID of this address type. Addresses in [`NodeAnnouncement`] messages should be sorted
        /// by this.
        pub(crate) fn get_id(&self) -> u8 {
                match self {
                        &NetAddress::IPv4 {..} => { 1 },
                        &NetAddress::IPv6 {..} => { 2 },
                        &NetAddress::OnionV2(_) => { 3 },
                        &NetAddress::OnionV3 {..} => { 4 },
                        &NetAddress::Hostname {..} => { 5 },
                }
        }

        /// Strict byte-length of address descriptor, 1-byte type not recorded
        fn len(&self) -> u16 {
                match self {
                        &NetAddress::IPv4 { .. } => { 6 },
                        &NetAddress::IPv6 { .. } => { 18 },
                        &NetAddress::OnionV2(_) => { 12 },
                        &NetAddress::OnionV3 { .. } => { 37 },
                        // Consists of 1-byte hostname length, hostname bytes, and 2-byte port.
                        &NetAddress::Hostname { ref hostname, .. } => { u16::from(hostname.len()) + 3 },
                }
        }

        /// The maximum length of any address descriptor, not including the 1-byte type.
        /// This maximum length is reached by a hostname address descriptor:
        /// a hostname with a maximum length of 255, its 1-byte length and a 2-byte port.
        pub(crate) const MAX_LEN: u16 = 258;
}

impl Writeable for NetAddress {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                match self {
                        &NetAddress::IPv4 { ref addr, ref port } => {
                                1u8.write(writer)?;
                                addr.write(writer)?;
                                port.write(writer)?;
                        },
                        &NetAddress::IPv6 { ref addr, ref port } => {
                                2u8.write(writer)?;
                                addr.write(writer)?;
                                port.write(writer)?;
                        },
                        &NetAddress::OnionV2(bytes) => {
                                3u8.write(writer)?;
                                bytes.write(writer)?;
                        },
                        &NetAddress::OnionV3 { ref ed25519_pubkey, ref checksum, ref version, ref port } => {
                                4u8.write(writer)?;
                                ed25519_pubkey.write(writer)?;
                                checksum.write(writer)?;
                                version.write(writer)?;
                                port.write(writer)?;
                        },
                        &NetAddress::Hostname { ref hostname, ref port } => {
                                5u8.write(writer)?;
                                hostname.write(writer)?;
                                port.write(writer)?;
                        },
                }
                Ok(())
        }
}

impl Readable for Result<NetAddress, u8> {
        fn read<R: Read>(reader: &mut R) -> Result<Result<NetAddress, u8>, DecodeError> {
                let byte = <u8 as Readable>::read(reader)?;
                match byte {
                        1 => {
                                Ok(Ok(NetAddress::IPv4 {
                                        addr: Readable::read(reader)?,
                                        port: Readable::read(reader)?,
                                }))
                        },
                        2 => {
                                Ok(Ok(NetAddress::IPv6 {
                                        addr: Readable::read(reader)?,
                                        port: Readable::read(reader)?,
                                }))
                        },
                        3 => Ok(Ok(NetAddress::OnionV2(Readable::read(reader)?))),
                        4 => {
                                Ok(Ok(NetAddress::OnionV3 {
                                        ed25519_pubkey: Readable::read(reader)?,
                                        checksum: Readable::read(reader)?,
                                        version: Readable::read(reader)?,
                                        port: Readable::read(reader)?,
                                }))
                        },
                        5 => {
                                Ok(Ok(NetAddress::Hostname {
                                        hostname: Readable::read(reader)?,
                                        port: Readable::read(reader)?,
                                }))
                        },
                        _ => return Ok(Err(byte)),
                }
        }
}

impl Readable for NetAddress {
        fn read<R: Read>(reader: &mut R) -> Result<NetAddress, DecodeError> {
                match Readable::read(reader) {
                        Ok(Ok(res)) => Ok(res),
                        Ok(Err(_)) => Err(DecodeError::UnknownVersion),
                        Err(e) => Err(e),
                }
        }
}

/// Represents the set of gossip messages that require a signature from a node's identity key.
pub enum UnsignedGossipMessage<'a> {
        /// An unsigned channel announcement.
        ChannelAnnouncement(&'a UnsignedChannelAnnouncement),
        /// An unsigned channel update.
        ChannelUpdate(&'a UnsignedChannelUpdate),
        /// An unsigned node announcement.
        NodeAnnouncement(&'a UnsignedNodeAnnouncement)
}

impl<'a> Writeable for UnsignedGossipMessage<'a> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                match self {
                        UnsignedGossipMessage::ChannelAnnouncement(ref msg) => msg.write(writer),
                        UnsignedGossipMessage::ChannelUpdate(ref msg) => msg.write(writer),
                        UnsignedGossipMessage::NodeAnnouncement(ref msg) => msg.write(writer),
                }
        }
}

/// The unsigned part of a [`node_announcement`] message.
///
/// [`node_announcement`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-node_announcement-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UnsignedNodeAnnouncement {
        /// The advertised features
        pub features: NodeFeatures,
        /// A strictly monotonic announcement counter, with gaps allowed
        pub timestamp: u32,
        /// The `node_id` this announcement originated from (don't rebroadcast the `node_announcement` back
        /// to this node).
        pub node_id: NodeId,
        /// An RGB color for UI purposes
        pub rgb: [u8; 3],
        /// An alias, for UI purposes.
        ///
        /// This should be sanitized before use. There is no guarantee of uniqueness.
        pub alias: NodeAlias,
        /// List of addresses on which this node is reachable
        pub addresses: Vec<NetAddress>,
        pub(crate) excess_address_data: Vec<u8>,
        pub(crate) excess_data: Vec<u8>,
}
#[derive(Clone, Debug, PartialEq, Eq)]
/// A [`node_announcement`] message to be sent to or received from a peer.
///
/// [`node_announcement`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-node_announcement-message
pub struct NodeAnnouncement {
        /// The signature by the node key
        pub signature: Signature,
        /// The actual content of the announcement
        pub contents: UnsignedNodeAnnouncement,
}

/// The unsigned part of a [`channel_announcement`] message.
///
/// [`channel_announcement`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_announcement-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UnsignedChannelAnnouncement {
        /// The advertised channel features
        pub features: ChannelFeatures,
        /// The genesis hash of the blockchain where the channel is to be opened
        pub chain_hash: BlockHash,
        /// The short channel ID
        pub short_channel_id: u64,
        /// One of the two `node_id`s which are endpoints of this channel
        pub node_id_1: NodeId,
        /// The other of the two `node_id`s which are endpoints of this channel
        pub node_id_2: NodeId,
        /// The funding key for the first node
        pub bitcoin_key_1: NodeId,
        /// The funding key for the second node
        pub bitcoin_key_2: NodeId,
        pub(crate) excess_data: Vec<u8>,
}
/// A [`channel_announcement`] message to be sent to or received from a peer.
///
/// [`channel_announcement`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_announcement-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ChannelAnnouncement {
        /// Authentication of the announcement by the first public node
        pub node_signature_1: Signature,
        /// Authentication of the announcement by the second public node
        pub node_signature_2: Signature,
        /// Proof of funding UTXO ownership by the first public node
        pub bitcoin_signature_1: Signature,
        /// Proof of funding UTXO ownership by the second public node
        pub bitcoin_signature_2: Signature,
        /// The actual announcement
        pub contents: UnsignedChannelAnnouncement,
}

/// The unsigned part of a [`channel_update`] message.
///
/// [`channel_update`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_update-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct UnsignedChannelUpdate {
        /// The genesis hash of the blockchain where the channel is to be opened
        pub chain_hash: BlockHash,
        /// The short channel ID
        pub short_channel_id: u64,
        /// A strictly monotonic announcement counter, with gaps allowed, specific to this channel
        pub timestamp: u32,
        /// Channel flags
        pub flags: u8,
        /// The number of blocks such that if:
        /// `incoming_htlc.cltv_expiry < outgoing_htlc.cltv_expiry + cltv_expiry_delta`
        /// then we need to fail the HTLC backwards. When forwarding an HTLC, `cltv_expiry_delta` determines
        /// the outgoing HTLC's minimum `cltv_expiry` value -- so, if an incoming HTLC comes in with a
        /// `cltv_expiry` of 100000, and the node we're forwarding to has a `cltv_expiry_delta` value of 10,
        /// then we'll check that the outgoing HTLC's `cltv_expiry` value is at least 100010 before
        /// forwarding. Note that the HTLC sender is the one who originally sets this value when
        /// constructing the route.
        pub cltv_expiry_delta: u16,
        /// The minimum HTLC size incoming to sender, in milli-satoshi
        pub htlc_minimum_msat: u64,
        /// The maximum HTLC value incoming to sender, in milli-satoshi.
        ///
        /// This used to be optional.
        pub htlc_maximum_msat: u64,
        /// The base HTLC fee charged by sender, in milli-satoshi
        pub fee_base_msat: u32,
        /// The amount to fee multiplier, in micro-satoshi
        pub fee_proportional_millionths: u32,
        /// Excess data which was signed as a part of the message which we do not (yet) understand how
        /// to decode.
        ///
        /// This is stored to ensure forward-compatibility as new fields are added to the lightning gossip protocol.
        pub excess_data: Vec<u8>,
}
/// A [`channel_update`] message to be sent to or received from a peer.
///
/// [`channel_update`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_update-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ChannelUpdate {
        /// A signature of the channel update
        pub signature: Signature,
        /// The actual channel update
        pub contents: UnsignedChannelUpdate,
}

/// A [`query_channel_range`] message is used to query a peer for channel
/// UTXOs in a range of blocks. The recipient of a query makes a best
/// effort to reply to the query using one or more [`ReplyChannelRange`]
/// messages.
///
/// [`query_channel_range`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-query_channel_range-and-reply_channel_range-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct QueryChannelRange {
        /// The genesis hash of the blockchain being queried
        pub chain_hash: BlockHash,
        /// The height of the first block for the channel UTXOs being queried
        pub first_blocknum: u32,
        /// The number of blocks to include in the query results
        pub number_of_blocks: u32,
}

/// A [`reply_channel_range`] message is a reply to a [`QueryChannelRange`]
/// message.
///
/// Multiple `reply_channel_range` messages can be sent in reply
/// to a single [`QueryChannelRange`] message. The query recipient makes a
/// best effort to respond based on their local network view which may
/// not be a perfect view of the network. The `short_channel_id`s in the
/// reply are encoded. We only support `encoding_type=0` uncompressed
/// serialization and do not support `encoding_type=1` zlib serialization.
///
/// [`reply_channel_range`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-query_channel_range-and-reply_channel_range-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ReplyChannelRange {
        /// The genesis hash of the blockchain being queried
        pub chain_hash: BlockHash,
        /// The height of the first block in the range of the reply
        pub first_blocknum: u32,
        /// The number of blocks included in the range of the reply
        pub number_of_blocks: u32,
        /// True when this is the final reply for a query
        pub sync_complete: bool,
        /// The `short_channel_id`s in the channel range
        pub short_channel_ids: Vec<u64>,
}

/// A [`query_short_channel_ids`] message is used to query a peer for
/// routing gossip messages related to one or more `short_channel_id`s.
///
/// The query recipient will reply with the latest, if available,
/// [`ChannelAnnouncement`], [`ChannelUpdate`] and [`NodeAnnouncement`] messages
/// it maintains for the requested `short_channel_id`s followed by a
/// [`ReplyShortChannelIdsEnd`] message. The `short_channel_id`s sent in
/// this query are encoded. We only support `encoding_type=0` uncompressed
/// serialization and do not support `encoding_type=1` zlib serialization.
///
/// [`query_short_channel_ids`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-query_short_channel_idsreply_short_channel_ids_end-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct QueryShortChannelIds {
        /// The genesis hash of the blockchain being queried
        pub chain_hash: BlockHash,
        /// The short_channel_ids that are being queried
        pub short_channel_ids: Vec<u64>,
}

/// A [`reply_short_channel_ids_end`] message is sent as a reply to a
/// message. The query recipient makes a best
/// effort to respond based on their local network view which may not be
/// a perfect view of the network.
///
/// [`reply_short_channel_ids_end`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-query_short_channel_idsreply_short_channel_ids_end-messages
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct ReplyShortChannelIdsEnd {
        /// The genesis hash of the blockchain that was queried
        pub chain_hash: BlockHash,
        /// Indicates if the query recipient maintains up-to-date channel
        /// information for the `chain_hash`
        pub full_information: bool,
}

/// A [`gossip_timestamp_filter`] message is used by a node to request
/// gossip relay for messages in the requested time range when the
/// `gossip_queries` feature has been negotiated.
///
/// [`gossip_timestamp_filter`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-gossip_timestamp_filter-message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct GossipTimestampFilter {
        /// The genesis hash of the blockchain for channel and node information
        pub chain_hash: BlockHash,
        /// The starting unix timestamp
        pub first_timestamp: u32,
        /// The range of information in seconds
        pub timestamp_range: u32,
}

/// Encoding type for data compression of collections in gossip queries.
///
/// We do not support `encoding_type=1` zlib serialization [defined in BOLT
/// #7](https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#query-messages).
enum EncodingType {
        Uncompressed = 0x00,
}

/// Used to put an error message in a [`LightningError`].
#[derive(Clone, Debug)]
pub enum ErrorAction {
        /// The peer took some action which made us think they were useless. Disconnect them.
        DisconnectPeer {
                /// An error message which we should make an effort to send before we disconnect.
                msg: Option<ErrorMessage>
        },
        /// The peer did something harmless that we weren't able to process, just log and ignore
        // New code should *not* use this. New code must use IgnoreAndLog, below!
        IgnoreError,
        /// The peer did something harmless that we weren't able to meaningfully process.
        /// If the error is logged, log it at the given level.
        IgnoreAndLog(logger::Level),
        /// The peer provided us with a gossip message which we'd already seen. In most cases this
        /// should be ignored, but it may result in the message being forwarded if it is a duplicate of
        /// our own channel announcements.
        IgnoreDuplicateGossip,
        /// The peer did something incorrect. Tell them.
        SendErrorMessage {
                /// The message to send.
                msg: ErrorMessage,
        },
        /// The peer did something incorrect. Tell them without closing any channels.
        SendWarningMessage {
                /// The message to send.
                msg: WarningMessage,
                /// The peer may have done something harmless that we weren't able to meaningfully process,
                /// though we should still tell them about it.
                /// If this event is logged, log it at the given level.
                log_level: logger::Level,
        },
}

/// An Err type for failure to process messages.
#[derive(Clone, Debug)]
pub struct LightningError {
        /// A human-readable message describing the error
        pub err: String,
        /// The action which should be taken against the offending peer.
        pub action: ErrorAction,
}

/// Struct used to return values from [`RevokeAndACK`] messages, containing a bunch of commitment
/// transaction updates if they were pending.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct CommitmentUpdate {
        /// `update_add_htlc` messages which should be sent
        pub update_add_htlcs: Vec<UpdateAddHTLC>,
        /// `update_fulfill_htlc` messages which should be sent
        pub update_fulfill_htlcs: Vec<UpdateFulfillHTLC>,
        /// `update_fail_htlc` messages which should be sent
        pub update_fail_htlcs: Vec<UpdateFailHTLC>,
        /// `update_fail_malformed_htlc` messages which should be sent
        pub update_fail_malformed_htlcs: Vec<UpdateFailMalformedHTLC>,
        /// An `update_fee` message which should be sent
        pub update_fee: Option<UpdateFee>,
        /// A `commitment_signed` message which should be sent
        pub commitment_signed: CommitmentSigned,
}

/// Messages could have optional fields to use with extended features
/// As we wish to serialize these differently from `Option<T>`s (`Options` get a tag byte, but
/// [`OptionalField`] simply gets `Present` if there are enough bytes to read into it), we have a
/// separate enum type for them.
///
/// This is not exported to bindings users due to a free generic in `T`
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum OptionalField<T> {
        /// Optional field is included in message
        Present(T),
        /// Optional field is absent in message
        Absent
}

/// A trait to describe an object which can receive channel messages.
///
/// Messages MAY be called in parallel when they originate from different `their_node_ids`, however
/// they MUST NOT be called in parallel when the two calls have the same `their_node_id`.
pub trait ChannelMessageHandler : MessageSendEventsProvider {
        // Channel init:
        /// Handle an incoming `open_channel` message from the given peer.
        fn handle_open_channel(&self, their_node_id: &PublicKey, msg: &OpenChannel);
        /// Handle an incoming `accept_channel` message from the given peer.
        fn handle_accept_channel(&self, their_node_id: &PublicKey, msg: &AcceptChannel);
        /// Handle an incoming `funding_created` message from the given peer.
        fn handle_funding_created(&self, their_node_id: &PublicKey, msg: &FundingCreated);
        /// Handle an incoming `funding_signed` message from the given peer.
        fn handle_funding_signed(&self, their_node_id: &PublicKey, msg: &FundingSigned);
        /// Handle an incoming `channel_ready` message from the given peer.
        fn handle_channel_ready(&self, their_node_id: &PublicKey, msg: &ChannelReady);

        // Channl close:
        /// Handle an incoming `shutdown` message from the given peer.
        fn handle_shutdown(&self, their_node_id: &PublicKey, msg: &Shutdown);
        /// Handle an incoming `closing_signed` message from the given peer.
        fn handle_closing_signed(&self, their_node_id: &PublicKey, msg: &ClosingSigned);

        // HTLC handling:
        /// Handle an incoming `update_add_htlc` message from the given peer.
        fn handle_update_add_htlc(&self, their_node_id: &PublicKey, msg: &UpdateAddHTLC);
        /// Handle an incoming `update_fulfill_htlc` message from the given peer.
        fn handle_update_fulfill_htlc(&self, their_node_id: &PublicKey, msg: &UpdateFulfillHTLC);
        /// Handle an incoming `update_fail_htlc` message from the given peer.
        fn handle_update_fail_htlc(&self, their_node_id: &PublicKey, msg: &UpdateFailHTLC);
        /// Handle an incoming `update_fail_malformed_htlc` message from the given peer.
        fn handle_update_fail_malformed_htlc(&self, their_node_id: &PublicKey, msg: &UpdateFailMalformedHTLC);
        /// Handle an incoming `commitment_signed` message from the given peer.
        fn handle_commitment_signed(&self, their_node_id: &PublicKey, msg: &CommitmentSigned);
        /// Handle an incoming `revoke_and_ack` message from the given peer.
        fn handle_revoke_and_ack(&self, their_node_id: &PublicKey, msg: &RevokeAndACK);

        /// Handle an incoming `update_fee` message from the given peer.
        fn handle_update_fee(&self, their_node_id: &PublicKey, msg: &UpdateFee);

        // Channel-to-announce:
        /// Handle an incoming `announcement_signatures` message from the given peer.
        fn handle_announcement_signatures(&self, their_node_id: &PublicKey, msg: &AnnouncementSignatures);

        // Connection loss/reestablish:
        /// Indicates a connection to the peer failed/an existing connection was lost.
        fn peer_disconnected(&self, their_node_id: &PublicKey);

        /// Handle a peer reconnecting, possibly generating `channel_reestablish` message(s).
        ///
        /// May return an `Err(())` if the features the peer supports are not sufficient to communicate
        /// with us. Implementors should be somewhat conservative about doing so, however, as other
        /// message handlers may still wish to communicate with this peer.
        fn peer_connected(&self, their_node_id: &PublicKey, msg: &Init, inbound: bool) -> Result<(), ()>;
        /// Handle an incoming `channel_reestablish` message from the given peer.
        fn handle_channel_reestablish(&self, their_node_id: &PublicKey, msg: &ChannelReestablish);

        /// Handle an incoming `channel_update` message from the given peer.
        fn handle_channel_update(&self, their_node_id: &PublicKey, msg: &ChannelUpdate);

        // Error:
        /// Handle an incoming `error` message from the given peer.
        fn handle_error(&self, their_node_id: &PublicKey, msg: &ErrorMessage);

        // Handler information:
        /// Gets the node feature flags which this handler itself supports. All available handlers are
        /// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
        /// which are broadcasted in our [`NodeAnnouncement`] message.
        fn provided_node_features(&self) -> NodeFeatures;

        /// Gets the init feature flags which should be sent to the given peer. All available handlers
        /// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
        /// which are sent in our [`Init`] message.
        ///
        /// Note that this method is called before [`Self::peer_connected`].
        fn provided_init_features(&self, their_node_id: &PublicKey) -> InitFeatures;
}

/// A trait to describe an object which can receive routing messages.
///
/// # Implementor DoS Warnings
///
/// For messages enabled with the `gossip_queries` feature there are potential DoS vectors when
/// handling inbound queries. Implementors using an on-disk network graph should be aware of
/// repeated disk I/O for queries accessing different parts of the network graph.
pub trait RoutingMessageHandler : MessageSendEventsProvider {
        /// Handle an incoming `node_announcement` message, returning `true` if it should be forwarded on,
        /// `false` or returning an `Err` otherwise.
        fn handle_node_announcement(&self, msg: &NodeAnnouncement) -> Result<bool, LightningError>;
        /// Handle a `channel_announcement` message, returning `true` if it should be forwarded on, `false`
        /// or returning an `Err` otherwise.
        fn handle_channel_announcement(&self, msg: &ChannelAnnouncement) -> Result<bool, LightningError>;
        /// Handle an incoming `channel_update` message, returning true if it should be forwarded on,
        /// `false` or returning an `Err` otherwise.
        fn handle_channel_update(&self, msg: &ChannelUpdate) -> Result<bool, LightningError>;
        /// Gets channel announcements and updates required to dump our routing table to a remote node,
        /// starting at the `short_channel_id` indicated by `starting_point` and including announcements
        /// for a single channel.
        fn get_next_channel_announcement(&self, starting_point: u64) -> Option<(ChannelAnnouncement, Option<ChannelUpdate>, Option<ChannelUpdate>)>;
        /// Gets a node announcement required to dump our routing table to a remote node, starting at
        /// the node *after* the provided pubkey and including up to one announcement immediately
        /// higher (as defined by `<PublicKey as Ord>::cmp`) than `starting_point`.
        /// If `None` is provided for `starting_point`, we start at the first node.
        fn get_next_node_announcement(&self, starting_point: Option<&NodeId>) -> Option<NodeAnnouncement>;
        /// Called when a connection is established with a peer. This can be used to
        /// perform routing table synchronization using a strategy defined by the
        /// implementor.
        ///
        /// May return an `Err(())` if the features the peer supports are not sufficient to communicate
        /// with us. Implementors should be somewhat conservative about doing so, however, as other
        /// message handlers may still wish to communicate with this peer.
        fn peer_connected(&self, their_node_id: &PublicKey, init: &Init, inbound: bool) -> Result<(), ()>;
        /// Handles the reply of a query we initiated to learn about channels
        /// for a given range of blocks. We can expect to receive one or more
        /// replies to a single query.
        fn handle_reply_channel_range(&self, their_node_id: &PublicKey, msg: ReplyChannelRange) -> Result<(), LightningError>;
        /// Handles the reply of a query we initiated asking for routing gossip
        /// messages for a list of channels. We should receive this message when
        /// a node has completed its best effort to send us the pertaining routing
        /// gossip messages.
        fn handle_reply_short_channel_ids_end(&self, their_node_id: &PublicKey, msg: ReplyShortChannelIdsEnd) -> Result<(), LightningError>;
        /// Handles when a peer asks us to send a list of `short_channel_id`s
        /// for the requested range of blocks.
        fn handle_query_channel_range(&self, their_node_id: &PublicKey, msg: QueryChannelRange) -> Result<(), LightningError>;
        /// Handles when a peer asks us to send routing gossip messages for a
        /// list of `short_channel_id`s.
        fn handle_query_short_channel_ids(&self, their_node_id: &PublicKey, msg: QueryShortChannelIds) -> Result<(), LightningError>;

        // Handler queueing status:
        /// Indicates that there are a large number of [`ChannelAnnouncement`] (or other) messages
        /// pending some async action. While there is no guarantee of the rate of future messages, the
        /// caller should seek to reduce the rate of new gossip messages handled, especially
        /// [`ChannelAnnouncement`]s.
        fn processing_queue_high(&self) -> bool;

        // Handler information:
        /// Gets the node feature flags which this handler itself supports. All available handlers are
        /// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
        /// which are broadcasted in our [`NodeAnnouncement`] message.
        fn provided_node_features(&self) -> NodeFeatures;
        /// Gets the init feature flags which should be sent to the given peer. All available handlers
        /// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
        /// which are sent in our [`Init`] message.
        ///
        /// Note that this method is called before [`Self::peer_connected`].
        fn provided_init_features(&self, their_node_id: &PublicKey) -> InitFeatures;
}

/// A trait to describe an object that can receive onion messages.
pub trait OnionMessageHandler : OnionMessageProvider {
        /// Handle an incoming `onion_message` message from the given peer.
        fn handle_onion_message(&self, peer_node_id: &PublicKey, msg: &OnionMessage);
        /// Called when a connection is established with a peer. Can be used to track which peers
        /// advertise onion message support and are online.
        ///
        /// May return an `Err(())` if the features the peer supports are not sufficient to communicate
        /// with us. Implementors should be somewhat conservative about doing so, however, as other
        /// message handlers may still wish to communicate with this peer.
        fn peer_connected(&self, their_node_id: &PublicKey, init: &Init, inbound: bool) -> Result<(), ()>;
        /// Indicates a connection to the peer failed/an existing connection was lost. Allows handlers to
        /// drop and refuse to forward onion messages to this peer.
        fn peer_disconnected(&self, their_node_id: &PublicKey);

        // Handler information:
        /// Gets the node feature flags which this handler itself supports. All available handlers are
        /// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
        /// which are broadcasted in our [`NodeAnnouncement`] message.
        fn provided_node_features(&self) -> NodeFeatures;

        /// Gets the init feature flags which should be sent to the given peer. All available handlers
        /// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
        /// which are sent in our [`Init`] message.
        ///
        /// Note that this method is called before [`Self::peer_connected`].
        fn provided_init_features(&self, their_node_id: &PublicKey) -> InitFeatures;
}

mod fuzzy_internal_msgs {
        use crate::prelude::*;
        use crate::ln::{PaymentPreimage, PaymentSecret};

        // These types aren't intended to be pub, but are exposed for direct fuzzing (as we deserialize
        // them from untrusted input):
        #[derive(Clone)]
        pub(crate) struct FinalOnionHopData {
                pub(crate) payment_secret: PaymentSecret,
                /// The total value, in msat, of the payment as received by the ultimate recipient.
                /// Message serialization may panic if this value is more than 21 million Bitcoin.
                pub(crate) total_msat: u64,
        }

        pub(crate) enum OnionHopDataFormat {
                NonFinalNode {
                        short_channel_id: u64,
                },
                FinalNode {
                        payment_data: Option<FinalOnionHopData>,
                        payment_metadata: Option<Vec<u8>>,
                        keysend_preimage: Option<PaymentPreimage>,
                },
        }

        pub struct OnionHopData {
                pub(crate) format: OnionHopDataFormat,
                /// The value, in msat, of the payment after this hop's fee is deducted.
                /// Message serialization may panic if this value is more than 21 million Bitcoin.
                pub(crate) amt_to_forward: u64,
                pub(crate) outgoing_cltv_value: u32,
        }

        pub struct DecodedOnionErrorPacket {
                pub(crate) hmac: [u8; 32],
                pub(crate) failuremsg: Vec<u8>,
                pub(crate) pad: Vec<u8>,
        }
}
#[cfg(fuzzing)]
pub use self::fuzzy_internal_msgs::*;
#[cfg(not(fuzzing))]
pub(crate) use self::fuzzy_internal_msgs::*;

#[derive(Clone)]
pub(crate) struct OnionPacket {
        pub(crate) version: u8,
        /// In order to ensure we always return an error on onion decode in compliance with [BOLT
        /// #4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md), we have to
        /// deserialize `OnionPacket`s contained in [`UpdateAddHTLC`] messages even if the ephemeral
        /// public key (here) is bogus, so we hold a [`Result`] instead of a [`PublicKey`] as we'd
        /// like.
        pub(crate) public_key: Result<PublicKey, secp256k1::Error>,
        pub(crate) hop_data: [u8; 20*65],
        pub(crate) hmac: [u8; 32],
}

impl onion_utils::Packet for OnionPacket {
        type Data = onion_utils::FixedSizeOnionPacket;
        fn new(pubkey: PublicKey, hop_data: onion_utils::FixedSizeOnionPacket, hmac: [u8; 32]) -> Self {
                Self {
                        version: 0,
                        public_key: Ok(pubkey),
                        hop_data: hop_data.0,
                        hmac,
                }
        }
}

impl Eq for OnionPacket { }
impl PartialEq for OnionPacket {
        fn eq(&self, other: &OnionPacket) -> bool {
                for (i, j) in self.hop_data.iter().zip(other.hop_data.iter()) {
                        if i != j { return false; }
                }
                self.version == other.version &&
                        self.public_key == other.public_key &&
                        self.hmac == other.hmac
        }
}

impl fmt::Debug for OnionPacket {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                f.write_fmt(format_args!("OnionPacket version {} with hmac {:?}", self.version, &self.hmac[..]))
        }
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub(crate) struct OnionErrorPacket {
        // This really should be a constant size slice, but the spec lets these things be up to 128KB?
        // (TODO) We limit it in decode to much lower...
        pub(crate) data: Vec<u8>,
}

impl fmt::Display for DecodeError {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                match *self {
                        DecodeError::UnknownVersion => f.write_str("Unknown realm byte in Onion packet"),
                        DecodeError::UnknownRequiredFeature => f.write_str("Unknown required feature preventing decode"),
                        DecodeError::InvalidValue => f.write_str("Nonsense bytes didn't map to the type they were interpreted as"),
                        DecodeError::ShortRead => f.write_str("Packet extended beyond the provided bytes"),
                        DecodeError::BadLengthDescriptor => f.write_str("A length descriptor in the packet didn't describe the later data correctly"),
                        DecodeError::Io(ref e) => fmt::Debug::fmt(e, f),
                        DecodeError::UnsupportedCompression => f.write_str("We don't support receiving messages with zlib-compressed fields"),
                }
        }
}

impl From<io::Error> for DecodeError {
        fn from(e: io::Error) -> Self {
                if e.kind() == io::ErrorKind::UnexpectedEof {
                        DecodeError::ShortRead
                } else {
                        DecodeError::Io(e.kind())
                }
        }
}

impl Writeable for OptionalField<Script> {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                match *self {
                        OptionalField::Present(ref script) => {
                                // Note that Writeable for script includes the 16-bit length tag for us
                                script.write(w)?;
                        },
                        OptionalField::Absent => {}
                }
                Ok(())
        }
}

impl Readable for OptionalField<Script> {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                match <u16 as Readable>::read(r) {
                        Ok(len) => {
                                let mut buf = vec![0; len as usize];
                                r.read_exact(&mut buf)?;
                                Ok(OptionalField::Present(Script::from(buf)))
                        },
                        Err(DecodeError::ShortRead) => Ok(OptionalField::Absent),
                        Err(e) => Err(e)
                }
        }
}

impl Writeable for OptionalField<u64> {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                match *self {
                        OptionalField::Present(ref value) => {
                                value.write(w)?;
                        },
                        OptionalField::Absent => {}
                }
                Ok(())
        }
}

impl Readable for OptionalField<u64> {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let value: u64 = Readable::read(r)?;
                Ok(OptionalField::Present(value))
        }
}

#[cfg(not(taproot))]
impl_writeable_msg!(AcceptChannel, {
        temporary_channel_id,
        dust_limit_satoshis,
        max_htlc_value_in_flight_msat,
        channel_reserve_satoshis,
        htlc_minimum_msat,
        minimum_depth,
        to_self_delay,
        max_accepted_htlcs,
        funding_pubkey,
        revocation_basepoint,
        payment_point,
        delayed_payment_basepoint,
        htlc_basepoint,
        first_per_commitment_point,
        shutdown_scriptpubkey
}, {
        (1, channel_type, option),
});

#[cfg(taproot)]
impl_writeable_msg!(AcceptChannel, {
        temporary_channel_id,
        dust_limit_satoshis,
        max_htlc_value_in_flight_msat,
        channel_reserve_satoshis,
        htlc_minimum_msat,
        minimum_depth,
        to_self_delay,
        max_accepted_htlcs,
        funding_pubkey,
        revocation_basepoint,
        payment_point,
        delayed_payment_basepoint,
        htlc_basepoint,
        first_per_commitment_point,
        shutdown_scriptpubkey
}, {
        (1, channel_type, option),
        (4, next_local_nonce, option),
});

impl_writeable_msg!(AnnouncementSignatures, {
        channel_id,
        short_channel_id,
        node_signature,
        bitcoin_signature
}, {});

impl Writeable for ChannelReestablish {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.channel_id.write(w)?;
                self.next_local_commitment_number.write(w)?;
                self.next_remote_commitment_number.write(w)?;
                match self.data_loss_protect {
                        OptionalField::Present(ref data_loss_protect) => {
                                (*data_loss_protect).your_last_per_commitment_secret.write(w)?;
                                (*data_loss_protect).my_current_per_commitment_point.write(w)?;
                        },
                        OptionalField::Absent => {}
                }
                Ok(())
        }
}

impl Readable for ChannelReestablish{
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Self {
                        channel_id: Readable::read(r)?,
                        next_local_commitment_number: Readable::read(r)?,
                        next_remote_commitment_number: Readable::read(r)?,
                        data_loss_protect: {
                                match <[u8; 32] as Readable>::read(r) {
                                        Ok(your_last_per_commitment_secret) =>
                                                OptionalField::Present(DataLossProtect {
                                                        your_last_per_commitment_secret,
                                                        my_current_per_commitment_point: Readable::read(r)?,
                                                }),
                                        Err(DecodeError::ShortRead) => OptionalField::Absent,
                                        Err(e) => return Err(e)
                                }
                        }
                })
        }
}

impl_writeable_msg!(ClosingSigned,
        { channel_id, fee_satoshis, signature },
        { (1, fee_range, option) }
);

impl_writeable!(ClosingSignedFeeRange, {
        min_fee_satoshis,
        max_fee_satoshis
});

#[cfg(not(taproot))]
impl_writeable_msg!(CommitmentSigned, {
        channel_id,
        signature,
        htlc_signatures
}, {});

#[cfg(taproot)]
impl_writeable_msg!(CommitmentSigned, {
        channel_id,
        signature,
        htlc_signatures
}, {
        (2, partial_signature_with_nonce, option)
});

impl_writeable!(DecodedOnionErrorPacket, {
        hmac,
        failuremsg,
        pad
});

#[cfg(not(taproot))]
impl_writeable_msg!(FundingCreated, {
        temporary_channel_id,
        funding_txid,
        funding_output_index,
        signature
}, {});
#[cfg(taproot)]
impl_writeable_msg!(FundingCreated, {
        temporary_channel_id,
        funding_txid,
        funding_output_index,
        signature
}, {
        (2, partial_signature_with_nonce, option),
        (4, next_local_nonce, option)
});

#[cfg(not(taproot))]
impl_writeable_msg!(FundingSigned, {
        channel_id,
        signature
}, {});

#[cfg(taproot)]
impl_writeable_msg!(FundingSigned, {
        channel_id,
        signature
}, {
        (2, partial_signature_with_nonce, option)
});

impl_writeable_msg!(ChannelReady, {
        channel_id,
        next_per_commitment_point,
}, {
        (1, short_channel_id_alias, option),
});

impl Writeable for Init {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                // global_features gets the bottom 13 bits of our features, and local_features gets all of
                // our relevant feature bits. This keeps us compatible with old nodes.
                self.features.write_up_to_13(w)?;
                self.features.write(w)?;
                encode_tlv_stream!(w, {
                        (3, self.remote_network_address, option)
                });
                Ok(())
        }
}

impl Readable for Init {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let global_features: InitFeatures = Readable::read(r)?;
                let features: InitFeatures = Readable::read(r)?;
                let mut remote_network_address: Option<NetAddress> = None;
                decode_tlv_stream!(r, {
                        (3, remote_network_address, option)
                });
                Ok(Init {
                        features: features.or(global_features),
                        remote_network_address,
                })
        }
}

impl_writeable_msg!(OpenChannel, {
        chain_hash,
        temporary_channel_id,
        funding_satoshis,
        push_msat,
        dust_limit_satoshis,
        max_htlc_value_in_flight_msat,
        channel_reserve_satoshis,
        htlc_minimum_msat,
        feerate_per_kw,
        to_self_delay,
        max_accepted_htlcs,
        funding_pubkey,
        revocation_basepoint,
        payment_point,
        delayed_payment_basepoint,
        htlc_basepoint,
        first_per_commitment_point,
        channel_flags,
        shutdown_scriptpubkey
}, {
        (1, channel_type, option),
});

#[cfg(not(taproot))]
impl_writeable_msg!(RevokeAndACK, {
        channel_id,
        per_commitment_secret,
        next_per_commitment_point
}, {});

#[cfg(taproot)]
impl_writeable_msg!(RevokeAndACK, {
        channel_id,
        per_commitment_secret,
        next_per_commitment_point
}, {
        (4, next_local_nonce, option)
});

impl_writeable_msg!(Shutdown, {
        channel_id,
        scriptpubkey
}, {});

impl_writeable_msg!(UpdateFailHTLC, {
        channel_id,
        htlc_id,
        reason
}, {});

impl_writeable_msg!(UpdateFailMalformedHTLC, {
        channel_id,
        htlc_id,
        sha256_of_onion,
        failure_code
}, {});

impl_writeable_msg!(UpdateFee, {
        channel_id,
        feerate_per_kw
}, {});

impl_writeable_msg!(UpdateFulfillHTLC, {
        channel_id,
        htlc_id,
        payment_preimage
}, {});

// Note that this is written as a part of ChannelManager objects, and thus cannot change its
// serialization format in a way which assumes we know the total serialized length/message end
// position.
impl_writeable!(OnionErrorPacket, {
        data
});

// Note that this is written as a part of ChannelManager objects, and thus cannot change its
// serialization format in a way which assumes we know the total serialized length/message end
// position.
impl Writeable for OnionPacket {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.version.write(w)?;
                match self.public_key {
                        Ok(pubkey) => pubkey.write(w)?,
                        Err(_) => [0u8;33].write(w)?,
                }
                w.write_all(&self.hop_data)?;
                self.hmac.write(w)?;
                Ok(())
        }
}

impl Readable for OnionPacket {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(OnionPacket {
                        version: Readable::read(r)?,
                        public_key: {
                                let mut buf = [0u8;33];
                                r.read_exact(&mut buf)?;
                                PublicKey::from_slice(&buf)
                        },
                        hop_data: Readable::read(r)?,
                        hmac: Readable::read(r)?,
                })
        }
}

impl_writeable_msg!(UpdateAddHTLC, {
        channel_id,
        htlc_id,
        amount_msat,
        payment_hash,
        cltv_expiry,
        onion_routing_packet
}, {});

impl Readable for OnionMessage {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let blinding_point: PublicKey = Readable::read(r)?;
                let len: u16 = Readable::read(r)?;
                let mut packet_reader = FixedLengthReader::new(r, len as u64);
                let onion_routing_packet: onion_message::Packet = <onion_message::Packet as LengthReadable>::read(&mut packet_reader)?;
                Ok(Self {
                        blinding_point,
                        onion_routing_packet,
                })
        }
}

impl Writeable for OnionMessage {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.blinding_point.write(w)?;
                let onion_packet_len = self.onion_routing_packet.serialized_length();
                (onion_packet_len as u16).write(w)?;
                self.onion_routing_packet.write(w)?;
                Ok(())
        }
}

impl Writeable for FinalOnionHopData {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.payment_secret.0.write(w)?;
                HighZeroBytesDroppedBigSize(self.total_msat).write(w)
        }
}

impl Readable for FinalOnionHopData {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let secret: [u8; 32] = Readable::read(r)?;
                let amt: HighZeroBytesDroppedBigSize<u64> = Readable::read(r)?;
                Ok(Self { payment_secret: PaymentSecret(secret), total_msat: amt.0 })
        }
}

impl Writeable for OnionHopData {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                match self.format {
                        OnionHopDataFormat::NonFinalNode { short_channel_id } => {
                                _encode_varint_length_prefixed_tlv!(w, {
                                        (2, HighZeroBytesDroppedBigSize(self.amt_to_forward), required),
                                        (4, HighZeroBytesDroppedBigSize(self.outgoing_cltv_value), required),
                                        (6, short_channel_id, required)
                                });
                        },
                        OnionHopDataFormat::FinalNode { ref payment_data, ref payment_metadata, ref keysend_preimage } => {
                                _encode_varint_length_prefixed_tlv!(w, {
                                        (2, HighZeroBytesDroppedBigSize(self.amt_to_forward), required),
                                        (4, HighZeroBytesDroppedBigSize(self.outgoing_cltv_value), required),
                                        (8, payment_data, option),
                                        (16, payment_metadata.as_ref().map(|m| WithoutLength(m)), option),
                                        (5482373484, keysend_preimage, option)
                                });
                        },
                }
                Ok(())
        }
}

impl Readable for OnionHopData {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let mut amt = HighZeroBytesDroppedBigSize(0u64);
                let mut cltv_value = HighZeroBytesDroppedBigSize(0u32);
                let mut short_id: Option<u64> = None;
                let mut payment_data: Option<FinalOnionHopData> = None;
                let mut payment_metadata: Option<WithoutLength<Vec<u8>>> = None;
                let mut keysend_preimage: Option<PaymentPreimage> = None;
                read_tlv_fields!(r, {
                        (2, amt, required),
                        (4, cltv_value, required),
                        (6, short_id, option),
                        (8, payment_data, option),
                        (16, payment_metadata, option),
                        // See https://github.com/lightning/blips/blob/master/blip-0003.md
                        (5482373484, keysend_preimage, option)
                });

                let format = if let Some(short_channel_id) = short_id {
                        if payment_data.is_some() { return Err(DecodeError::InvalidValue); }
                        if payment_metadata.is_some() { return Err(DecodeError::InvalidValue); }
                        OnionHopDataFormat::NonFinalNode {
                                short_channel_id,
                        }
                } else {
                        if let Some(data) = &payment_data {
                                if data.total_msat > MAX_VALUE_MSAT {
                                        return Err(DecodeError::InvalidValue);
                                }
                        }
                        OnionHopDataFormat::FinalNode {
                                payment_data,
                                payment_metadata: payment_metadata.map(|w| w.0),
                                keysend_preimage,
                        }
                };

                if amt.0 > MAX_VALUE_MSAT {
                        return Err(DecodeError::InvalidValue);
                }
                Ok(OnionHopData {
                        format,
                        amt_to_forward: amt.0,
                        outgoing_cltv_value: cltv_value.0,
                })
        }
}

// ReadableArgs because we need onion_utils::decode_next_hop to accommodate payment packets and
// onion message packets.
impl ReadableArgs<()> for OnionHopData {
        fn read<R: Read>(r: &mut R, _arg: ()) -> Result<Self, DecodeError> {
                <Self as Readable>::read(r)
        }
}

impl Writeable for Ping {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.ponglen.write(w)?;
                vec![0u8; self.byteslen as usize].write(w)?; // size-unchecked write
                Ok(())
        }
}

impl Readable for Ping {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Ping {
                        ponglen: Readable::read(r)?,
                        byteslen: {
                                let byteslen = Readable::read(r)?;
                                r.read_exact(&mut vec![0u8; byteslen as usize][..])?;
                                byteslen
                        }
                })
        }
}

impl Writeable for Pong {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                vec![0u8; self.byteslen as usize].write(w)?; // size-unchecked write
                Ok(())
        }
}

impl Readable for Pong {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Pong {
                        byteslen: {
                                let byteslen = Readable::read(r)?;
                                r.read_exact(&mut vec![0u8; byteslen as usize][..])?;
                                byteslen
                        }
                })
        }
}

impl Writeable for UnsignedChannelAnnouncement {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.features.write(w)?;
                self.chain_hash.write(w)?;
                self.short_channel_id.write(w)?;
                self.node_id_1.write(w)?;
                self.node_id_2.write(w)?;
                self.bitcoin_key_1.write(w)?;
                self.bitcoin_key_2.write(w)?;
                w.write_all(&self.excess_data[..])?;
                Ok(())
        }
}

impl Readable for UnsignedChannelAnnouncement {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Self {
                        features: Readable::read(r)?,
                        chain_hash: Readable::read(r)?,
                        short_channel_id: Readable::read(r)?,
                        node_id_1: Readable::read(r)?,
                        node_id_2: Readable::read(r)?,
                        bitcoin_key_1: Readable::read(r)?,
                        bitcoin_key_2: Readable::read(r)?,
                        excess_data: read_to_end(r)?,
                })
        }
}

impl_writeable!(ChannelAnnouncement, {
        node_signature_1,
        node_signature_2,
        bitcoin_signature_1,
        bitcoin_signature_2,
        contents
});

impl Writeable for UnsignedChannelUpdate {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                // `message_flags` used to indicate presence of `htlc_maximum_msat`, but was deprecated in the spec.
                const MESSAGE_FLAGS: u8 = 1;
                self.chain_hash.write(w)?;
                self.short_channel_id.write(w)?;
                self.timestamp.write(w)?;
                let all_flags = self.flags as u16 | ((MESSAGE_FLAGS as u16) << 8);
                all_flags.write(w)?;
                self.cltv_expiry_delta.write(w)?;
                self.htlc_minimum_msat.write(w)?;
                self.fee_base_msat.write(w)?;
                self.fee_proportional_millionths.write(w)?;
                self.htlc_maximum_msat.write(w)?;
                w.write_all(&self.excess_data[..])?;
                Ok(())
        }
}

impl Readable for UnsignedChannelUpdate {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Self {
                        chain_hash: Readable::read(r)?,
                        short_channel_id: Readable::read(r)?,
                        timestamp: Readable::read(r)?,
                        flags: {
                                let flags: u16 = Readable::read(r)?;
                                // Note: we ignore the `message_flags` for now, since it was deprecated by the spec.
                                flags as u8
                        },
                        cltv_expiry_delta: Readable::read(r)?,
                        htlc_minimum_msat: Readable::read(r)?,
                        fee_base_msat: Readable::read(r)?,
                        fee_proportional_millionths: Readable::read(r)?,
                        htlc_maximum_msat: Readable::read(r)?,
                        excess_data: read_to_end(r)?,
                })
        }
}

impl_writeable!(ChannelUpdate, {
        signature,
        contents
});

impl Writeable for ErrorMessage {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.channel_id.write(w)?;
                (self.data.len() as u16).write(w)?;
                w.write_all(self.data.as_bytes())?;
                Ok(())
        }
}

impl Readable for ErrorMessage {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Self {
                        channel_id: Readable::read(r)?,
                        data: {
                                let sz: usize = <u16 as Readable>::read(r)? as usize;
                                let mut data = Vec::with_capacity(sz);
                                data.resize(sz, 0);
                                r.read_exact(&mut data)?;
                                match String::from_utf8(data) {
                                        Ok(s) => s,
                                        Err(_) => return Err(DecodeError::InvalidValue),
                                }
                        }
                })
        }
}

impl Writeable for WarningMessage {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.channel_id.write(w)?;
                (self.data.len() as u16).write(w)?;
                w.write_all(self.data.as_bytes())?;
                Ok(())
        }
}

impl Readable for WarningMessage {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                Ok(Self {
                        channel_id: Readable::read(r)?,
                        data: {
                                let sz: usize = <u16 as Readable>::read(r)? as usize;
                                let mut data = Vec::with_capacity(sz);
                                data.resize(sz, 0);
                                r.read_exact(&mut data)?;
                                match String::from_utf8(data) {
                                        Ok(s) => s,
                                        Err(_) => return Err(DecodeError::InvalidValue),
                                }
                        }
                })
        }
}

impl Writeable for UnsignedNodeAnnouncement {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                self.features.write(w)?;
                self.timestamp.write(w)?;
                self.node_id.write(w)?;
                w.write_all(&self.rgb)?;
                self.alias.write(w)?;

                let mut addr_len = 0;
                for addr in self.addresses.iter() {
                        addr_len += 1 + addr.len();
                }
                (addr_len + self.excess_address_data.len() as u16).write(w)?;
                for addr in self.addresses.iter() {
                        addr.write(w)?;
                }
                w.write_all(&self.excess_address_data[..])?;
                w.write_all(&self.excess_data[..])?;
                Ok(())
        }
}

impl Readable for UnsignedNodeAnnouncement {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let features: NodeFeatures = Readable::read(r)?;
                let timestamp: u32 = Readable::read(r)?;
                let node_id: NodeId = Readable::read(r)?;
                let mut rgb = [0; 3];
                r.read_exact(&mut rgb)?;
                let alias: NodeAlias = Readable::read(r)?;

                let addr_len: u16 = Readable::read(r)?;
                let mut addresses: Vec<NetAddress> = Vec::new();
                let mut addr_readpos = 0;
                let mut excess = false;
                let mut excess_byte = 0;
                loop {
                        if addr_len <= addr_readpos { break; }
                        match Readable::read(r) {
                                Ok(Ok(addr)) => {
                                        if addr_len < addr_readpos + 1 + addr.len() {
                                                return Err(DecodeError::BadLengthDescriptor);
                                        }
                                        addr_readpos += (1 + addr.len()) as u16;
                                        addresses.push(addr);
                                },
                                Ok(Err(unknown_descriptor)) => {
                                        excess = true;
                                        excess_byte = unknown_descriptor;
                                        break;
                                },
                                Err(DecodeError::ShortRead) => return Err(DecodeError::BadLengthDescriptor),
                                Err(e) => return Err(e),
                        }
                }

                let mut excess_data = vec![];
                let excess_address_data = if addr_readpos < addr_len {
                        let mut excess_address_data = vec![0; (addr_len - addr_readpos) as usize];
                        r.read_exact(&mut excess_address_data[if excess { 1 } else { 0 }..])?;
                        if excess {
                                excess_address_data[0] = excess_byte;
                        }
                        excess_address_data
                } else {
                        if excess {
                                excess_data.push(excess_byte);
                        }
                        Vec::new()
                };
                excess_data.extend(read_to_end(r)?.iter());
                Ok(UnsignedNodeAnnouncement {
                        features,
                        timestamp,
                        node_id,
                        rgb,
                        alias,
                        addresses,
                        excess_address_data,
                        excess_data,
                })
        }
}

impl_writeable!(NodeAnnouncement, {
        signature,
        contents
});

impl Readable for QueryShortChannelIds {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let chain_hash: BlockHash = Readable::read(r)?;

                let encoding_len: u16 = Readable::read(r)?;
                let encoding_type: u8 = Readable::read(r)?;

                // Must be encoding_type=0 uncompressed serialization. We do not
                // support encoding_type=1 zlib serialization.
                if encoding_type != EncodingType::Uncompressed as u8 {
                        return Err(DecodeError::UnsupportedCompression);
                }

                // We expect the encoding_len to always includes the 1-byte
                // encoding_type and that short_channel_ids are 8-bytes each
                if encoding_len == 0 || (encoding_len - 1) % 8 != 0 {
                        return Err(DecodeError::InvalidValue);
                }

                // Read short_channel_ids (8-bytes each), for the u16 encoding_len
                // less the 1-byte encoding_type
                let short_channel_id_count: u16 = (encoding_len - 1)/8;
                let mut short_channel_ids = Vec::with_capacity(short_channel_id_count as usize);
                for _ in 0..short_channel_id_count {
                        short_channel_ids.push(Readable::read(r)?);
                }

                Ok(QueryShortChannelIds {
                        chain_hash,
                        short_channel_ids,
                })
        }
}

impl Writeable for QueryShortChannelIds {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                // Calculated from 1-byte encoding_type plus 8-bytes per short_channel_id
                let encoding_len: u16 = 1 + self.short_channel_ids.len() as u16 * 8;

                self.chain_hash.write(w)?;
                encoding_len.write(w)?;

                // We only support type=0 uncompressed serialization
                (EncodingType::Uncompressed as u8).write(w)?;

                for scid in self.short_channel_ids.iter() {
                        scid.write(w)?;
                }

                Ok(())
        }
}

impl_writeable_msg!(ReplyShortChannelIdsEnd, {
        chain_hash,
        full_information,
}, {});

impl QueryChannelRange {
        /// Calculates the overflow safe ending block height for the query.
        ///
        /// Overflow returns `0xffffffff`, otherwise returns `first_blocknum + number_of_blocks`.
        pub fn end_blocknum(&self) -> u32 {
                match self.first_blocknum.checked_add(self.number_of_blocks) {
                        Some(block) => block,
                        None => u32::max_value(),
                }
        }
}

impl_writeable_msg!(QueryChannelRange, {
        chain_hash,
        first_blocknum,
        number_of_blocks
}, {});

impl Readable for ReplyChannelRange {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
                let chain_hash: BlockHash = Readable::read(r)?;
                let first_blocknum: u32 = Readable::read(r)?;
                let number_of_blocks: u32 = Readable::read(r)?;
                let sync_complete: bool = Readable::read(r)?;

                let encoding_len: u16 = Readable::read(r)?;
                let encoding_type: u8 = Readable::read(r)?;

                // Must be encoding_type=0 uncompressed serialization. We do not
                // support encoding_type=1 zlib serialization.
                if encoding_type != EncodingType::Uncompressed as u8 {
                        return Err(DecodeError::UnsupportedCompression);
                }

                // We expect the encoding_len to always includes the 1-byte
                // encoding_type and that short_channel_ids are 8-bytes each
                if encoding_len == 0 || (encoding_len - 1) % 8 != 0 {
                        return Err(DecodeError::InvalidValue);
                }

                // Read short_channel_ids (8-bytes each), for the u16 encoding_len
                // less the 1-byte encoding_type
                let short_channel_id_count: u16 = (encoding_len - 1)/8;
                let mut short_channel_ids = Vec::with_capacity(short_channel_id_count as usize);
                for _ in 0..short_channel_id_count {
                        short_channel_ids.push(Readable::read(r)?);
                }

                Ok(ReplyChannelRange {
                        chain_hash,
                        first_blocknum,
                        number_of_blocks,
                        sync_complete,
                        short_channel_ids
                })
        }
}

impl Writeable for ReplyChannelRange {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                let encoding_len: u16 = 1 + self.short_channel_ids.len() as u16 * 8;
                self.chain_hash.write(w)?;
                self.first_blocknum.write(w)?;
                self.number_of_blocks.write(w)?;
                self.sync_complete.write(w)?;

                encoding_len.write(w)?;
                (EncodingType::Uncompressed as u8).write(w)?;
                for scid in self.short_channel_ids.iter() {
                        scid.write(w)?;
                }

                Ok(())
        }
}

impl_writeable_msg!(GossipTimestampFilter, {
        chain_hash,
        first_timestamp,
        timestamp_range,
}, {});

#[cfg(test)]
mod tests {
        use hex;
        use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
        use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
        use crate::ln::msgs;
        use crate::ln::msgs::{FinalOnionHopData, OptionalField, OnionErrorPacket, OnionHopDataFormat};
        use crate::routing::gossip::{NodeAlias, NodeId};
        use crate::util::ser::{Writeable, Readable, Hostname};

        use bitcoin::hashes::hex::FromHex;
        use bitcoin::util::address::Address;
        use bitcoin::network::constants::Network;
        use bitcoin::blockdata::script::Builder;
        use bitcoin::blockdata::opcodes;
        use bitcoin::hash_types::{Txid, BlockHash};

        use bitcoin::secp256k1::{PublicKey,SecretKey};
        use bitcoin::secp256k1::{Secp256k1, Message};

        use crate::io::{self, Cursor};
        use crate::prelude::*;
        use core::convert::TryFrom;

        #[test]
        fn encoding_channel_reestablish_no_secret() {
                let cr = msgs::ChannelReestablish {
                        channel_id: [4, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0],
                        next_local_commitment_number: 3,
                        next_remote_commitment_number: 4,
                        data_loss_protect: OptionalField::Absent,
                };

                let encoded_value = cr.encode();
                assert_eq!(
                        encoded_value,
                        vec![4, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 4]
                );
        }

        #[test]
        fn encoding_channel_reestablish_with_secret() {
                let public_key = {
                        let secp_ctx = Secp256k1::new();
                        PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap())
                };

                let cr = msgs::ChannelReestablish {
                        channel_id: [4, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0],
                        next_local_commitment_number: 3,
                        next_remote_commitment_number: 4,
                        data_loss_protect: OptionalField::Present(msgs::DataLossProtect { your_last_per_commitment_secret: [9;32], my_current_per_commitment_point: public_key}),
                };

                let encoded_value = cr.encode();
                assert_eq!(
                        encoded_value,
                        vec![4, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 4, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 3, 27, 132, 197, 86, 123, 18, 100, 64, 153, 93, 62, 213, 170, 186, 5, 101, 215, 30, 24, 52, 96, 72, 25, 255, 156, 23, 245, 233, 213, 221, 7, 143]
                );
        }

        macro_rules! get_keys_from {
                ($slice: expr, $secp_ctx: expr) => {
                        {
                                let privkey = SecretKey::from_slice(&hex::decode($slice).unwrap()[..]).unwrap();
                                let pubkey = PublicKey::from_secret_key(&$secp_ctx, &privkey);
                                (privkey, pubkey)
                        }
                }
        }

        macro_rules! get_sig_on {
                ($privkey: expr, $ctx: expr, $string: expr) => {
                        {
                                let sighash = Message::from_slice(&$string.into_bytes()[..]).unwrap();
                                $ctx.sign_ecdsa(&sighash, &$privkey)
                        }
                }
        }

        #[test]
        fn encoding_announcement_signatures() {
                let secp_ctx = Secp256k1::new();
                let (privkey, _) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let sig_1 = get_sig_on!(privkey, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_2 = get_sig_on!(privkey, secp_ctx, String::from("02020202020202020202020202020202"));
                let announcement_signatures = msgs::AnnouncementSignatures {
                        channel_id: [4, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0],
                        short_channel_id: 2316138423780173,
                        node_signature: sig_1,
                        bitcoin_signature: sig_2,
                };

                let encoded_value = announcement_signatures.encode();
                assert_eq!(encoded_value, hex::decode("040000000000000005000000000000000600000000000000070000000000000000083a840000034dd977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073acf9953cef4700860f5967838eba2bae89288ad188ebf8b20bf995c3ea53a26df1876d0a3a0e13172ba286a673140190c02ba9da60a2e43a745188c8a83c7f3ef").unwrap());
        }

        fn do_encoding_channel_announcement(unknown_features_bits: bool, excess_data: bool) {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let (privkey_2, pubkey_2) = get_keys_from!("0202020202020202020202020202020202020202020202020202020202020202", secp_ctx);
                let (privkey_3, pubkey_3) = get_keys_from!("0303030303030303030303030303030303030303030303030303030303030303", secp_ctx);
                let (privkey_4, pubkey_4) = get_keys_from!("0404040404040404040404040404040404040404040404040404040404040404", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_2 = get_sig_on!(privkey_2, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_3 = get_sig_on!(privkey_3, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_4 = get_sig_on!(privkey_4, secp_ctx, String::from("01010101010101010101010101010101"));
                let mut features = ChannelFeatures::empty();
                if unknown_features_bits {
                        features = ChannelFeatures::from_le_bytes(vec![0xFF, 0xFF]);
                }
                let unsigned_channel_announcement = msgs::UnsignedChannelAnnouncement {
                        features,
                        chain_hash: BlockHash::from_hex("6fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000").unwrap(),
                        short_channel_id: 2316138423780173,
                        node_id_1: NodeId::from_pubkey(&pubkey_1),
                        node_id_2: NodeId::from_pubkey(&pubkey_2),
                        bitcoin_key_1: NodeId::from_pubkey(&pubkey_3),
                        bitcoin_key_2: NodeId::from_pubkey(&pubkey_4),
                        excess_data: if excess_data { vec![10, 0, 0, 20, 0, 0, 30, 0, 0, 40] } else { Vec::new() },
                };
                let channel_announcement = msgs::ChannelAnnouncement {
                        node_signature_1: sig_1,
                        node_signature_2: sig_2,
                        bitcoin_signature_1: sig_3,
                        bitcoin_signature_2: sig_4,
                        contents: unsigned_channel_announcement,
                };
                let encoded_value = channel_announcement.encode();
                let mut target_value = hex::decode("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").unwrap();
                if unknown_features_bits {
                        target_value.append(&mut hex::decode("0002ffff").unwrap());
                } else {
                        target_value.append(&mut hex::decode("0000").unwrap());
                }
                target_value.append(&mut hex::decode("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f").unwrap());
                target_value.append(&mut hex::decode("00083a840000034d031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f024d4b6cd1361032ca9bd2aeb9d900aa4d45d9ead80ac9423374c451a7254d076602531fe6068134503d2723133227c867ac8fa6c83c537e9a44c3c5bdbdcb1fe33703462779ad4aad39514614751a71085f2f10e1c7a593e4e030efb5b8721ce55b0b").unwrap());
                if excess_data {
                        target_value.append(&mut hex::decode("0a00001400001e000028").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_channel_announcement() {
                do_encoding_channel_announcement(true, false);
                do_encoding_channel_announcement(false, true);
                do_encoding_channel_announcement(false, false);
                do_encoding_channel_announcement(true, true);
        }

        fn do_encoding_node_announcement(unknown_features_bits: bool, ipv4: bool, ipv6: bool, onionv2: bool, onionv3: bool, hostname: bool, excess_address_data: bool, excess_data: bool) {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let features = if unknown_features_bits {
                        NodeFeatures::from_le_bytes(vec![0xFF, 0xFF])
                } else {
                        // Set to some features we may support
                        NodeFeatures::from_le_bytes(vec![2 | 1 << 5])
                };
                let mut addresses = Vec::new();
                if ipv4 {
                        addresses.push(msgs::NetAddress::IPv4 {
                                addr: [255, 254, 253, 252],
                                port: 9735
                        });
                }
                if ipv6 {
                        addresses.push(msgs::NetAddress::IPv6 {
                                addr: [255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240],
                                port: 9735
                        });
                }
                if onionv2 {
                        addresses.push(msgs::NetAddress::OnionV2(
                                [255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 38, 7]
                        ));
                }
                if onionv3 {
                        addresses.push(msgs::NetAddress::OnionV3 {
                                ed25519_pubkey: [255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232, 231, 230, 229, 228, 227, 226, 225, 224],
                                checksum: 32,
                                version: 16,
                                port: 9735
                        });
                }
                if hostname {
                        addresses.push(msgs::NetAddress::Hostname {
                                hostname: Hostname::try_from(String::from("host")).unwrap(),
                                port: 9735,
                        });
                }
                let mut addr_len = 0;
                for addr in &addresses {
                        addr_len += addr.len() + 1;
                }
                let unsigned_node_announcement = msgs::UnsignedNodeAnnouncement {
                        features,
                        timestamp: 20190119,
                        node_id: NodeId::from_pubkey(&pubkey_1),
                        rgb: [32; 3],
                        alias: NodeAlias([16;32]),
                        addresses,
                        excess_address_data: if excess_address_data { vec![33, 108, 40, 11, 83, 149, 162, 84, 110, 126, 75, 38, 99, 224, 79, 129, 22, 34, 241, 90, 79, 146, 232, 58, 162, 233, 43, 162, 165, 115, 193, 57, 20, 44, 84, 174, 99, 7, 42, 30, 193, 238, 125, 192, 192, 75, 222, 92, 132, 120, 6, 23, 42, 160, 92, 146, 194, 42, 232, 227, 8, 209, 210, 105] } else { Vec::new() },
                        excess_data: if excess_data { vec![59, 18, 204, 25, 92, 224, 162, 209, 189, 166, 168, 139, 239, 161, 159, 160, 127, 81, 202, 167, 92, 232, 56, 55, 242, 137, 101, 96, 11, 138, 172, 171, 8, 85, 255, 176, 231, 65, 236, 95, 124, 65, 66, 30, 152, 41, 169, 212, 134, 17, 200, 200, 49, 247, 27, 229, 234, 115, 230, 101, 148, 151, 127, 253] } else { Vec::new() },
                };
                addr_len += unsigned_node_announcement.excess_address_data.len() as u16;
                let node_announcement = msgs::NodeAnnouncement {
                        signature: sig_1,
                        contents: unsigned_node_announcement,
                };
                let encoded_value = node_announcement.encode();
                let mut target_value = hex::decode("d977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a").unwrap();
                if unknown_features_bits {
                        target_value.append(&mut hex::decode("0002ffff").unwrap());
                } else {
                        target_value.append(&mut hex::decode("000122").unwrap());
                }
                target_value.append(&mut hex::decode("013413a7031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f2020201010101010101010101010101010101010101010101010101010101010101010").unwrap());
                target_value.append(&mut vec![(addr_len >> 8) as u8, addr_len as u8]);
                if ipv4 {
                        target_value.append(&mut hex::decode("01fffefdfc2607").unwrap());
                }
                if ipv6 {
                        target_value.append(&mut hex::decode("02fffefdfcfbfaf9f8f7f6f5f4f3f2f1f02607").unwrap());
                }
                if onionv2 {
                        target_value.append(&mut hex::decode("03fffefdfcfbfaf9f8f7f62607").unwrap());
                }
                if onionv3 {
                        target_value.append(&mut hex::decode("04fffefdfcfbfaf9f8f7f6f5f4f3f2f1f0efeeedecebeae9e8e7e6e5e4e3e2e1e00020102607").unwrap());
                }
                if hostname {
                        target_value.append(&mut hex::decode("0504686f73742607").unwrap());
                }
                if excess_address_data {
                        target_value.append(&mut hex::decode("216c280b5395a2546e7e4b2663e04f811622f15a4f92e83aa2e92ba2a573c139142c54ae63072a1ec1ee7dc0c04bde5c847806172aa05c92c22ae8e308d1d269").unwrap());
                }
                if excess_data {
                        target_value.append(&mut hex::decode("3b12cc195ce0a2d1bda6a88befa19fa07f51caa75ce83837f28965600b8aacab0855ffb0e741ec5f7c41421e9829a9d48611c8c831f71be5ea73e66594977ffd").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_node_announcement() {
                do_encoding_node_announcement(true, true, true, true, true, true, true, true);
                do_encoding_node_announcement(false, false, false, false, false, false, false, false);
                do_encoding_node_announcement(false, true, false, false, false, false, false, false);
                do_encoding_node_announcement(false, false, true, false, false, false, false, false);
                do_encoding_node_announcement(false, false, false, true, false, false, false, false);
                do_encoding_node_announcement(false, false, false, false, true, false, false, false);
                do_encoding_node_announcement(false, false, false, false, false, true, false, false);
                do_encoding_node_announcement(false, false, false, false, false, false, true, false);
                do_encoding_node_announcement(false, true, false, true, false, false, true, false);
                do_encoding_node_announcement(false, false, true, false, true, false, false, false);
        }

        fn do_encoding_channel_update(direction: bool, disable: bool, excess_data: bool) {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, _) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let unsigned_channel_update = msgs::UnsignedChannelUpdate {
                        chain_hash: BlockHash::from_hex("6fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000").unwrap(),
                        short_channel_id: 2316138423780173,
                        timestamp: 20190119,
                        flags: if direction { 1 } else { 0 } | if disable { 1 << 1 } else { 0 },
                        cltv_expiry_delta: 144,
                        htlc_minimum_msat: 1000000,
                        htlc_maximum_msat: 131355275467161,
                        fee_base_msat: 10000,
                        fee_proportional_millionths: 20,
                        excess_data: if excess_data { vec![0, 0, 0, 0, 59, 154, 202, 0] } else { Vec::new() }
                };
                let channel_update = msgs::ChannelUpdate {
                        signature: sig_1,
                        contents: unsigned_channel_update
                };
                let encoded_value = channel_update.encode();
                let mut target_value = hex::decode("d977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a").unwrap();
                target_value.append(&mut hex::decode("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f").unwrap());
                target_value.append(&mut hex::decode("00083a840000034d013413a7").unwrap());
                target_value.append(&mut hex::decode("01").unwrap());
                target_value.append(&mut hex::decode("00").unwrap());
                if direction {
                        let flag = target_value.last_mut().unwrap();
                        *flag = 1;
                }
                if disable {
                        let flag = target_value.last_mut().unwrap();
                        *flag = *flag | 1 << 1;
                }
                target_value.append(&mut hex::decode("009000000000000f42400000271000000014").unwrap());
                target_value.append(&mut hex::decode("0000777788889999").unwrap());
                if excess_data {
                        target_value.append(&mut hex::decode("000000003b9aca00").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_channel_update() {
                do_encoding_channel_update(false, false, false);
                do_encoding_channel_update(false, false, true);
                do_encoding_channel_update(true, false, false);
                do_encoding_channel_update(true, false, true);
                do_encoding_channel_update(false, true, false);
                do_encoding_channel_update(false, true, true);
                do_encoding_channel_update(true, true, false);
                do_encoding_channel_update(true, true, true);
        }

        fn do_encoding_open_channel(random_bit: bool, shutdown: bool, incl_chan_type: bool) {
                let secp_ctx = Secp256k1::new();
                let (_, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let (_, pubkey_2) = get_keys_from!("0202020202020202020202020202020202020202020202020202020202020202", secp_ctx);
                let (_, pubkey_3) = get_keys_from!("0303030303030303030303030303030303030303030303030303030303030303", secp_ctx);
                let (_, pubkey_4) = get_keys_from!("0404040404040404040404040404040404040404040404040404040404040404", secp_ctx);
                let (_, pubkey_5) = get_keys_from!("0505050505050505050505050505050505050505050505050505050505050505", secp_ctx);
                let (_, pubkey_6) = get_keys_from!("0606060606060606060606060606060606060606060606060606060606060606", secp_ctx);
                let open_channel = msgs::OpenChannel {
                        chain_hash: BlockHash::from_hex("6fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000").unwrap(),
                        temporary_channel_id: [2; 32],
                        funding_satoshis: 1311768467284833366,
                        push_msat: 2536655962884945560,
                        dust_limit_satoshis: 3608586615801332854,
                        max_htlc_value_in_flight_msat: 8517154655701053848,
                        channel_reserve_satoshis: 8665828695742877976,
                        htlc_minimum_msat: 2316138423780173,
                        feerate_per_kw: 821716,
                        to_self_delay: 49340,
                        max_accepted_htlcs: 49340,
                        funding_pubkey: pubkey_1,
                        revocation_basepoint: pubkey_2,
                        payment_point: pubkey_3,
                        delayed_payment_basepoint: pubkey_4,
                        htlc_basepoint: pubkey_5,
                        first_per_commitment_point: pubkey_6,
                        channel_flags: if random_bit { 1 << 5 } else { 0 },
                        shutdown_scriptpubkey: if shutdown { OptionalField::Present(Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: pubkey_1}, Network::Testnet).script_pubkey()) } else { OptionalField::Absent },
                        channel_type: if incl_chan_type { Some(ChannelTypeFeatures::empty()) } else { None },
                };
                let encoded_value = open_channel.encode();
                let mut target_value = Vec::new();
                target_value.append(&mut hex::decode("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f").unwrap());
                target_value.append(&mut hex::decode("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").unwrap());
                if random_bit {
                        target_value.append(&mut hex::decode("20").unwrap());
                } else {
                        target_value.append(&mut hex::decode("00").unwrap());
                }
                if shutdown {
                        target_value.append(&mut hex::decode("001976a91479b000887626b294a914501a4cd226b58b23598388ac").unwrap());
                }
                if incl_chan_type {
                        target_value.append(&mut hex::decode("0100").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_open_channel() {
                do_encoding_open_channel(false, false, false);
                do_encoding_open_channel(false, false, true);
                do_encoding_open_channel(false, true, false);
                do_encoding_open_channel(false, true, true);
                do_encoding_open_channel(true, false, false);
                do_encoding_open_channel(true, false, true);
                do_encoding_open_channel(true, true, false);
                do_encoding_open_channel(true, true, true);
        }

        fn do_encoding_accept_channel(shutdown: bool) {
                let secp_ctx = Secp256k1::new();
                let (_, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let (_, pubkey_2) = get_keys_from!("0202020202020202020202020202020202020202020202020202020202020202", secp_ctx);
                let (_, pubkey_3) = get_keys_from!("0303030303030303030303030303030303030303030303030303030303030303", secp_ctx);
                let (_, pubkey_4) = get_keys_from!("0404040404040404040404040404040404040404040404040404040404040404", secp_ctx);
                let (_, pubkey_5) = get_keys_from!("0505050505050505050505050505050505050505050505050505050505050505", secp_ctx);
                let (_, pubkey_6) = get_keys_from!("0606060606060606060606060606060606060606060606060606060606060606", secp_ctx);
                let accept_channel = msgs::AcceptChannel {
                        temporary_channel_id: [2; 32],
                        dust_limit_satoshis: 1311768467284833366,
                        max_htlc_value_in_flight_msat: 2536655962884945560,
                        channel_reserve_satoshis: 3608586615801332854,
                        htlc_minimum_msat: 2316138423780173,
                        minimum_depth: 821716,
                        to_self_delay: 49340,
                        max_accepted_htlcs: 49340,
                        funding_pubkey: pubkey_1,
                        revocation_basepoint: pubkey_2,
                        payment_point: pubkey_3,
                        delayed_payment_basepoint: pubkey_4,
                        htlc_basepoint: pubkey_5,
                        first_per_commitment_point: pubkey_6,
                        shutdown_scriptpubkey: if shutdown { OptionalField::Present(Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: pubkey_1}, Network::Testnet).script_pubkey()) } else { OptionalField::Absent },
                        channel_type: None,
                        #[cfg(taproot)]
                        next_local_nonce: None,
                };
                let encoded_value = accept_channel.encode();
                let mut target_value = hex::decode("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").unwrap();
                if shutdown {
                        target_value.append(&mut hex::decode("001976a91479b000887626b294a914501a4cd226b58b23598388ac").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_accept_channel() {
                do_encoding_accept_channel(false);
                do_encoding_accept_channel(true);
        }

        #[test]
        fn encoding_funding_created() {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, _) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let funding_created = msgs::FundingCreated {
                        temporary_channel_id: [2; 32],
                        funding_txid: Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap(),
                        funding_output_index: 255,
                        signature: sig_1,
                        #[cfg(taproot)]
                        partial_signature_with_nonce: None,
                        #[cfg(taproot)]
                        next_local_nonce: None,
                };
                let encoded_value = funding_created.encode();
                let target_value = hex::decode("02020202020202020202020202020202020202020202020202020202020202026e96fe9f8b0ddcd729ba03cfafa5a27b050b39d354dd980814268dfa9a44d4c200ffd977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_funding_signed() {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, _) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let funding_signed = msgs::FundingSigned {
                        channel_id: [2; 32],
                        signature: sig_1,
                        #[cfg(taproot)]
                        partial_signature_with_nonce: None,
                };
                let encoded_value = funding_signed.encode();
                let target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202d977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_channel_ready() {
                let secp_ctx = Secp256k1::new();
                let (_, pubkey_1,) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let channel_ready = msgs::ChannelReady {
                        channel_id: [2; 32],
                        next_per_commitment_point: pubkey_1,
                        short_channel_id_alias: None,
                };
                let encoded_value = channel_ready.encode();
                let target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        fn do_encoding_shutdown(script_type: u8) {
                let secp_ctx = Secp256k1::new();
                let (_, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let script = Builder::new().push_opcode(opcodes::OP_TRUE).into_script();
                let shutdown = msgs::Shutdown {
                        channel_id: [2; 32],
                        scriptpubkey:
                                     if script_type == 1 { Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: pubkey_1}, Network::Testnet).script_pubkey() }
                                else if script_type == 2 { Address::p2sh(&script, Network::Testnet).unwrap().script_pubkey() }
                                else if script_type == 3 { Address::p2wpkh(&::bitcoin::PublicKey{compressed: true, inner: pubkey_1}, Network::Testnet).unwrap().script_pubkey() }
                                else                     { Address::p2wsh(&script, Network::Testnet).script_pubkey() },
                };
                let encoded_value = shutdown.encode();
                let mut target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap();
                if script_type == 1 {
                        target_value.append(&mut hex::decode("001976a91479b000887626b294a914501a4cd226b58b23598388ac").unwrap());
                } else if script_type == 2 {
                        target_value.append(&mut hex::decode("0017a914da1745e9b549bd0bfa1a569971c77eba30cd5a4b87").unwrap());
                } else if script_type == 3 {
                        target_value.append(&mut hex::decode("0016001479b000887626b294a914501a4cd226b58b235983").unwrap());
                } else if script_type == 4 {
                        target_value.append(&mut hex::decode("002200204ae81572f06e1b88fd5ced7a1a000945432e83e1551e6f721ee9c00b8cc33260").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_shutdown() {
                do_encoding_shutdown(1);
                do_encoding_shutdown(2);
                do_encoding_shutdown(3);
                do_encoding_shutdown(4);
        }

        #[test]
        fn encoding_closing_signed() {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, _) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let closing_signed = msgs::ClosingSigned {
                        channel_id: [2; 32],
                        fee_satoshis: 2316138423780173,
                        signature: sig_1,
                        fee_range: None,
                };
                let encoded_value = closing_signed.encode();
                let target_value = hex::decode("020202020202020202020202020202020202020202020202020202020202020200083a840000034dd977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a").unwrap();
                assert_eq!(encoded_value, target_value);
                assert_eq!(msgs::ClosingSigned::read(&mut Cursor::new(&target_value)).unwrap(), closing_signed);

                let closing_signed_with_range = msgs::ClosingSigned {
                        channel_id: [2; 32],
                        fee_satoshis: 2316138423780173,
                        signature: sig_1,
                        fee_range: Some(msgs::ClosingSignedFeeRange {
                                min_fee_satoshis: 0xdeadbeef,
                                max_fee_satoshis: 0x1badcafe01234567,
                        }),
                };
                let encoded_value_with_range = closing_signed_with_range.encode();
                let target_value_with_range = hex::decode("020202020202020202020202020202020202020202020202020202020202020200083a840000034dd977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a011000000000deadbeef1badcafe01234567").unwrap();
                assert_eq!(encoded_value_with_range, target_value_with_range);
                assert_eq!(msgs::ClosingSigned::read(&mut Cursor::new(&target_value_with_range)).unwrap(),
                        closing_signed_with_range);
        }

        #[test]
        fn encoding_update_add_htlc() {
                let secp_ctx = Secp256k1::new();
                let (_, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let onion_routing_packet = msgs::OnionPacket {
                        version: 255,
                        public_key: Ok(pubkey_1),
                        hop_data: [1; 20*65],
                        hmac: [2; 32]
                };
                let update_add_htlc = msgs::UpdateAddHTLC {
                        channel_id: [2; 32],
                        htlc_id: 2316138423780173,
                        amount_msat: 3608586615801332854,
                        payment_hash: PaymentHash([1; 32]),
                        cltv_expiry: 821716,
                        onion_routing_packet
                };
                let encoded_value = update_add_htlc.encode();
                let target_value = hex::decode("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").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_update_fulfill_htlc() {
                let update_fulfill_htlc = msgs::UpdateFulfillHTLC {
                        channel_id: [2; 32],
                        htlc_id: 2316138423780173,
                        payment_preimage: PaymentPreimage([1; 32]),
                };
                let encoded_value = update_fulfill_htlc.encode();
                let target_value = hex::decode("020202020202020202020202020202020202020202020202020202020202020200083a840000034d0101010101010101010101010101010101010101010101010101010101010101").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_update_fail_htlc() {
                let reason = OnionErrorPacket {
                        data: [1; 32].to_vec(),
                };
                let update_fail_htlc = msgs::UpdateFailHTLC {
                        channel_id: [2; 32],
                        htlc_id: 2316138423780173,
                        reason
                };
                let encoded_value = update_fail_htlc.encode();
                let target_value = hex::decode("020202020202020202020202020202020202020202020202020202020202020200083a840000034d00200101010101010101010101010101010101010101010101010101010101010101").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_update_fail_malformed_htlc() {
                let update_fail_malformed_htlc = msgs::UpdateFailMalformedHTLC {
                        channel_id: [2; 32],
                        htlc_id: 2316138423780173,
                        sha256_of_onion: [1; 32],
                        failure_code: 255
                };
                let encoded_value = update_fail_malformed_htlc.encode();
                let target_value = hex::decode("020202020202020202020202020202020202020202020202020202020202020200083a840000034d010101010101010101010101010101010101010101010101010101010101010100ff").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        fn do_encoding_commitment_signed(htlcs: bool) {
                let secp_ctx = Secp256k1::new();
                let (privkey_1, _) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let (privkey_2, _) = get_keys_from!("0202020202020202020202020202020202020202020202020202020202020202", secp_ctx);
                let (privkey_3, _) = get_keys_from!("0303030303030303030303030303030303030303030303030303030303030303", secp_ctx);
                let (privkey_4, _) = get_keys_from!("0404040404040404040404040404040404040404040404040404040404040404", secp_ctx);
                let sig_1 = get_sig_on!(privkey_1, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_2 = get_sig_on!(privkey_2, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_3 = get_sig_on!(privkey_3, secp_ctx, String::from("01010101010101010101010101010101"));
                let sig_4 = get_sig_on!(privkey_4, secp_ctx, String::from("01010101010101010101010101010101"));
                let commitment_signed = msgs::CommitmentSigned {
                        channel_id: [2; 32],
                        signature: sig_1,
                        htlc_signatures: if htlcs { vec![sig_2, sig_3, sig_4] } else { Vec::new() },
                        #[cfg(taproot)]
                        partial_signature_with_nonce: None,
                };
                let encoded_value = commitment_signed.encode();
                let mut target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202d977cb9b53d93a6ff64bb5f1e158b4094b66e798fb12911168a3ccdf80a83096340a6a95da0ae8d9f776528eecdbb747eb6b545495a4319ed5378e35b21e073a").unwrap();
                if htlcs {
                        target_value.append(&mut hex::decode("00031735b6a427e80d5fe7cd90a2f4ee08dc9c27cda7c35a4172e5d85b12c49d4232537e98f9b1f3c5e6989a8b9644e90e8918127680dbd0d4043510840fc0f1e11a216c280b5395a2546e7e4b2663e04f811622f15a4f91e83aa2e92ba2a573c139142c54ae63072a1ec1ee7dc0c04bde5c847806172aa05c92c22ae8e308d1d2692b12cc195ce0a2d1bda6a88befa19fa07f51caa75ce83837f28965600b8aacab0855ffb0e741ec5f7c41421e9829a9d48611c8c831f71be5ea73e66594977ffd").unwrap());
                } else {
                        target_value.append(&mut hex::decode("0000").unwrap());
                }
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_commitment_signed() {
                do_encoding_commitment_signed(true);
                do_encoding_commitment_signed(false);
        }

        #[test]
        fn encoding_revoke_and_ack() {
                let secp_ctx = Secp256k1::new();
                let (_, pubkey_1) = get_keys_from!("0101010101010101010101010101010101010101010101010101010101010101", secp_ctx);
                let raa = msgs::RevokeAndACK {
                        channel_id: [2; 32],
                        per_commitment_secret: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
                        next_per_commitment_point: pubkey_1,
                        #[cfg(taproot)]
                        next_local_nonce: None,
                };
                let encoded_value = raa.encode();
                let target_value = hex::decode("02020202020202020202020202020202020202020202020202020202020202020101010101010101010101010101010101010101010101010101010101010101031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_update_fee() {
                let update_fee = msgs::UpdateFee {
                        channel_id: [2; 32],
                        feerate_per_kw: 20190119,
                };
                let encoded_value = update_fee.encode();
                let target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202013413a7").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_init() {
                assert_eq!(msgs::Init {
                        features: InitFeatures::from_le_bytes(vec![0xFF, 0xFF, 0xFF]),
                        remote_network_address: None,
                }.encode(), hex::decode("00023fff0003ffffff").unwrap());
                assert_eq!(msgs::Init {
                        features: InitFeatures::from_le_bytes(vec![0xFF]),
                        remote_network_address: None,
                }.encode(), hex::decode("0001ff0001ff").unwrap());
                assert_eq!(msgs::Init {
                        features: InitFeatures::from_le_bytes(vec![]),
                        remote_network_address: None,
                }.encode(), hex::decode("00000000").unwrap());

                let init_msg = msgs::Init { features: InitFeatures::from_le_bytes(vec![]),
                        remote_network_address: Some(msgs::NetAddress::IPv4 {
                                addr: [127, 0, 0, 1],
                                port: 1000,
                        }),
                };
                let encoded_value = init_msg.encode();
                let target_value = hex::decode("000000000307017f00000103e8").unwrap();
                assert_eq!(encoded_value, target_value);
                assert_eq!(msgs::Init::read(&mut Cursor::new(&target_value)).unwrap(), init_msg);
        }

        #[test]
        fn encoding_error() {
                let error = msgs::ErrorMessage {
                        channel_id: [2; 32],
                        data: String::from("rust-lightning"),
                };
                let encoded_value = error.encode();
                let target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202000e727573742d6c696768746e696e67").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_warning() {
                let error = msgs::WarningMessage {
                        channel_id: [2; 32],
                        data: String::from("rust-lightning"),
                };
                let encoded_value = error.encode();
                let target_value = hex::decode("0202020202020202020202020202020202020202020202020202020202020202000e727573742d6c696768746e696e67").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_ping() {
                let ping = msgs::Ping {
                        ponglen: 64,
                        byteslen: 64
                };
                let encoded_value = ping.encode();
                let target_value = hex::decode("0040004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_pong() {
                let pong = msgs::Pong {
                        byteslen: 64
                };
                let encoded_value = pong.encode();
                let target_value = hex::decode("004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
                assert_eq!(encoded_value, target_value);
        }

        #[test]
        fn encoding_nonfinal_onion_hop_data() {
                let mut msg = msgs::OnionHopData {
                        format: OnionHopDataFormat::NonFinalNode {
                                short_channel_id: 0xdeadbeef1bad1dea,
                        },
                        amt_to_forward: 0x0badf00d01020304,
                        outgoing_cltv_value: 0xffffffff,
                };
                let encoded_value = msg.encode();
                let target_value = hex::decode("1a02080badf00d010203040404ffffffff0608deadbeef1bad1dea").unwrap();
                assert_eq!(encoded_value, target_value);
                msg = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                if let OnionHopDataFormat::NonFinalNode { short_channel_id } = msg.format {
                        assert_eq!(short_channel_id, 0xdeadbeef1bad1dea);
                } else { panic!(); }
                assert_eq!(msg.amt_to_forward, 0x0badf00d01020304);
                assert_eq!(msg.outgoing_cltv_value, 0xffffffff);
        }

        #[test]
        fn encoding_final_onion_hop_data() {
                let mut msg = msgs::OnionHopData {
                        format: OnionHopDataFormat::FinalNode {
                                payment_data: None,
                                payment_metadata: None,
                                keysend_preimage: None,
                        },
                        amt_to_forward: 0x0badf00d01020304,
                        outgoing_cltv_value: 0xffffffff,
                };
                let encoded_value = msg.encode();
                let target_value = hex::decode("1002080badf00d010203040404ffffffff").unwrap();
                assert_eq!(encoded_value, target_value);
                msg = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                if let OnionHopDataFormat::FinalNode { payment_data: None, .. } = msg.format { } else { panic!(); }
                assert_eq!(msg.amt_to_forward, 0x0badf00d01020304);
                assert_eq!(msg.outgoing_cltv_value, 0xffffffff);
        }

        #[test]
        fn encoding_final_onion_hop_data_with_secret() {
                let expected_payment_secret = PaymentSecret([0x42u8; 32]);
                let mut msg = msgs::OnionHopData {
                        format: OnionHopDataFormat::FinalNode {
                                payment_data: Some(FinalOnionHopData {
                                        payment_secret: expected_payment_secret,
                                        total_msat: 0x1badca1f
                                }),
                                payment_metadata: None,
                                keysend_preimage: None,
                        },
                        amt_to_forward: 0x0badf00d01020304,
                        outgoing_cltv_value: 0xffffffff,
                };
                let encoded_value = msg.encode();
                let target_value = hex::decode("3602080badf00d010203040404ffffffff082442424242424242424242424242424242424242424242424242424242424242421badca1f").unwrap();
                assert_eq!(encoded_value, target_value);
                msg = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                if let OnionHopDataFormat::FinalNode {
                        payment_data: Some(FinalOnionHopData {
                                payment_secret,
                                total_msat: 0x1badca1f
                        }),
                        payment_metadata: None,
                        keysend_preimage: None,
                } = msg.format {
                        assert_eq!(payment_secret, expected_payment_secret);
                } else { panic!(); }
                assert_eq!(msg.amt_to_forward, 0x0badf00d01020304);
                assert_eq!(msg.outgoing_cltv_value, 0xffffffff);
        }

        #[test]
        fn query_channel_range_end_blocknum() {
                let tests: Vec<(u32, u32, u32)> = vec![
                        (10000, 1500, 11500),
                        (0, 0xffffffff, 0xffffffff),
                        (1, 0xffffffff, 0xffffffff),
                ];

                for (first_blocknum, number_of_blocks, expected) in tests.into_iter() {
                        let sut = msgs::QueryChannelRange {
                                chain_hash: BlockHash::from_hex("06226e46111a0b59caaf126043eb5bbf28c34f3a5e332a1fc7b2b73cf188910f").unwrap(),
                                first_blocknum,
                                number_of_blocks,
                        };
                        assert_eq!(sut.end_blocknum(), expected);
                }
        }

        #[test]
        fn encoding_query_channel_range() {
                let mut query_channel_range = msgs::QueryChannelRange {
                        chain_hash: BlockHash::from_hex("06226e46111a0b59caaf126043eb5bbf28c34f3a5e332a1fc7b2b73cf188910f").unwrap(),
                        first_blocknum: 100000,
                        number_of_blocks: 1500,
                };
                let encoded_value = query_channel_range.encode();
                let target_value = hex::decode("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206000186a0000005dc").unwrap();
                assert_eq!(encoded_value, target_value);

                query_channel_range = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                assert_eq!(query_channel_range.first_blocknum, 100000);
                assert_eq!(query_channel_range.number_of_blocks, 1500);
        }

        #[test]
        fn encoding_reply_channel_range() {
                do_encoding_reply_channel_range(0);
                do_encoding_reply_channel_range(1);
        }

        fn do_encoding_reply_channel_range(encoding_type: u8) {
                let mut target_value = hex::decode("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206000b8a06000005dc01").unwrap();
                let expected_chain_hash = BlockHash::from_hex("06226e46111a0b59caaf126043eb5bbf28c34f3a5e332a1fc7b2b73cf188910f").unwrap();
                let mut reply_channel_range = msgs::ReplyChannelRange {
                        chain_hash: expected_chain_hash,
                        first_blocknum: 756230,
                        number_of_blocks: 1500,
                        sync_complete: true,
                        short_channel_ids: vec![0x000000000000008e, 0x0000000000003c69, 0x000000000045a6c4],
                };

                if encoding_type == 0 {
                        target_value.append(&mut hex::decode("001900000000000000008e0000000000003c69000000000045a6c4").unwrap());
                        let encoded_value = reply_channel_range.encode();
                        assert_eq!(encoded_value, target_value);

                        reply_channel_range = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                        assert_eq!(reply_channel_range.chain_hash, expected_chain_hash);
                        assert_eq!(reply_channel_range.first_blocknum, 756230);
                        assert_eq!(reply_channel_range.number_of_blocks, 1500);
                        assert_eq!(reply_channel_range.sync_complete, true);
                        assert_eq!(reply_channel_range.short_channel_ids[0], 0x000000000000008e);
                        assert_eq!(reply_channel_range.short_channel_ids[1], 0x0000000000003c69);
                        assert_eq!(reply_channel_range.short_channel_ids[2], 0x000000000045a6c4);
                } else {
                        target_value.append(&mut hex::decode("001601789c636000833e08659309a65878be010010a9023a").unwrap());
                        let result: Result<msgs::ReplyChannelRange, msgs::DecodeError> = Readable::read(&mut Cursor::new(&target_value[..]));
                        assert!(result.is_err(), "Expected decode failure with unsupported zlib encoding");
                }
        }

        #[test]
        fn encoding_query_short_channel_ids() {
                do_encoding_query_short_channel_ids(0);
                do_encoding_query_short_channel_ids(1);
        }

        fn do_encoding_query_short_channel_ids(encoding_type: u8) {
                let mut target_value = hex::decode("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206").unwrap();
                let expected_chain_hash = BlockHash::from_hex("06226e46111a0b59caaf126043eb5bbf28c34f3a5e332a1fc7b2b73cf188910f").unwrap();
                let mut query_short_channel_ids = msgs::QueryShortChannelIds {
                        chain_hash: expected_chain_hash,
                        short_channel_ids: vec![0x0000000000008e, 0x0000000000003c69, 0x000000000045a6c4],
                };

                if encoding_type == 0 {
                        target_value.append(&mut hex::decode("001900000000000000008e0000000000003c69000000000045a6c4").unwrap());
                        let encoded_value = query_short_channel_ids.encode();
                        assert_eq!(encoded_value, target_value);

                        query_short_channel_ids = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                        assert_eq!(query_short_channel_ids.chain_hash, expected_chain_hash);
                        assert_eq!(query_short_channel_ids.short_channel_ids[0], 0x000000000000008e);
                        assert_eq!(query_short_channel_ids.short_channel_ids[1], 0x0000000000003c69);
                        assert_eq!(query_short_channel_ids.short_channel_ids[2], 0x000000000045a6c4);
                } else {
                        target_value.append(&mut hex::decode("001601789c636000833e08659309a65878be010010a9023a").unwrap());
                        let result: Result<msgs::QueryShortChannelIds, msgs::DecodeError> = Readable::read(&mut Cursor::new(&target_value[..]));
                        assert!(result.is_err(), "Expected decode failure with unsupported zlib encoding");
                }
        }

        #[test]
        fn encoding_reply_short_channel_ids_end() {
                let expected_chain_hash = BlockHash::from_hex("06226e46111a0b59caaf126043eb5bbf28c34f3a5e332a1fc7b2b73cf188910f").unwrap();
                let mut reply_short_channel_ids_end = msgs::ReplyShortChannelIdsEnd {
                        chain_hash: expected_chain_hash,
                        full_information: true,
                };
                let encoded_value = reply_short_channel_ids_end.encode();
                let target_value = hex::decode("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e220601").unwrap();
                assert_eq!(encoded_value, target_value);

                reply_short_channel_ids_end = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                assert_eq!(reply_short_channel_ids_end.chain_hash, expected_chain_hash);
                assert_eq!(reply_short_channel_ids_end.full_information, true);
        }

        #[test]
        fn encoding_gossip_timestamp_filter(){
                let expected_chain_hash = BlockHash::from_hex("06226e46111a0b59caaf126043eb5bbf28c34f3a5e332a1fc7b2b73cf188910f").unwrap();
                let mut gossip_timestamp_filter = msgs::GossipTimestampFilter {
                        chain_hash: expected_chain_hash,
                        first_timestamp: 1590000000,
                        timestamp_range: 0xffff_ffff,
                };
                let encoded_value = gossip_timestamp_filter.encode();
                let target_value = hex::decode("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e22065ec57980ffffffff").unwrap();
                assert_eq!(encoded_value, target_value);

                gossip_timestamp_filter = Readable::read(&mut Cursor::new(&target_value[..])).unwrap();
                assert_eq!(gossip_timestamp_filter.chain_hash, expected_chain_hash);
                assert_eq!(gossip_timestamp_filter.first_timestamp, 1590000000);
                assert_eq!(gossip_timestamp_filter.timestamp_range, 0xffff_ffff);
        }

        #[test]
        fn decode_onion_hop_data_len_as_bigsize() {
                // Tests that we can decode an onion payload that is >253 bytes.
                // Previously, receiving a payload of this size could've caused us to fail to decode a valid
                // payload, because we were decoding the length (a BigSize, big-endian) as a VarInt
                // (little-endian).

                // Encode a test onion payload with a big custom TLV such that it's >253 bytes, forcing the
                // payload length to be encoded over multiple bytes rather than a single u8.
                let big_payload = encode_big_payload().unwrap();
                let mut rd = Cursor::new(&big_payload[..]);
                <msgs::OnionHopData as Readable>::read(&mut rd).unwrap();
        }
        // see above test, needs to be a separate method for use of the serialization macros.
        fn encode_big_payload() -> Result<Vec<u8>, io::Error> {
                use crate::util::ser::HighZeroBytesDroppedBigSize;
                let payload = msgs::OnionHopData {
                        format: OnionHopDataFormat::NonFinalNode {
                                short_channel_id: 0xdeadbeef1bad1dea,
                        },
                        amt_to_forward: 1000,
                        outgoing_cltv_value: 0xffffffff,
                };
                let mut encoded_payload = Vec::new();
                let test_bytes = vec![42u8; 1000];
                if let OnionHopDataFormat::NonFinalNode { short_channel_id } = payload.format {
                        _encode_varint_length_prefixed_tlv!(&mut encoded_payload, {
                                (1, test_bytes, vec_type),
                                (2, HighZeroBytesDroppedBigSize(payload.amt_to_forward), required),
                                (4, HighZeroBytesDroppedBigSize(payload.outgoing_cltv_value), required),
                                (6, short_channel_id, required)
                        });
                }
                Ok(encoded_payload)
        }
}