From: Matt Corallo Date: Wed, 28 Jul 2021 20:24:20 +0000 (+0000) Subject: Migrate OnchainEvent serialization to be MaybeReadable. X-Git-Tag: v0.0.100~2^2 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=refs%2Fheads%2F2021-08-chanmon-ser-upgradability;p=rust-lightning Migrate OnchainEvent serialization to be MaybeReadable. This adds a new TLV-based enum serialization macro entitled `impl_writeable_tlv_based_enum_upgradable`. As the name implies, the new macro allows us to ignore odd-numbered variant entries. Because the new macro implements only `MaybeReadable` and not `Readable`, it is not applicable in many contexts, here only being added for the two `OnchainEvent` structs. --- diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs index 3c75ec9e9..9c381a350 100644 --- a/lightning/src/chain/channelmonitor.rs +++ b/lightning/src/chain/channelmonitor.rs @@ -106,7 +106,9 @@ impl Readable for ChannelMonitorUpdate { let len: u64 = Readable::read(r)?; let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::())); for _ in 0..len { - updates.push(Readable::read(r)?); + if let Some(upd) = MaybeReadable::read(r)? { + updates.push(upd); + } } read_tlv_fields!(r, {}); Ok(Self { update_id, updates }) @@ -394,13 +396,36 @@ enum OnchainEvent { }, } -impl_writeable_tlv_based!(OnchainEventEntry, { - (0, txid, required), - (2, height, required), - (4, event, required), -}); +impl Writeable for OnchainEventEntry { + fn write(&self, writer: &mut W) -> Result<(), io::Error> { + write_tlv_fields!(writer, { + (0, self.txid, required), + (2, self.height, required), + (4, self.event, required), + }); + Ok(()) + } +} -impl_writeable_tlv_based_enum!(OnchainEvent, +impl MaybeReadable for OnchainEventEntry { + fn read(reader: &mut R) -> Result, DecodeError> { + let mut txid = Default::default(); + let mut height = 0; + let mut event = None; + read_tlv_fields!(reader, { + (0, txid, required), + (2, height, required), + (4, event, ignorable), + }); + if let Some(ev) = event { + Ok(Some(Self { txid, height, event: ev })) + } else { + Ok(None) + } + } +} + +impl_writeable_tlv_based_enum_upgradable!(OnchainEvent, (0, HTLCUpdate) => { (0, source, required), (1, onchain_value_satoshis, option), @@ -409,7 +434,7 @@ impl_writeable_tlv_based_enum!(OnchainEvent, (1, MaturingOutput) => { (0, descriptor, required), }, -;); +); #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))] #[derive(Clone)] @@ -443,7 +468,7 @@ pub(crate) enum ChannelMonitorUpdateStep { }, } -impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep, +impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep, (0, LatestHolderCommitmentTXInfo) => { (0, commitment_tx, required), (2, htlc_outputs, vec_type), @@ -467,7 +492,7 @@ impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep, (5, ShutdownScript) => { (0, scriptpubkey, required), }, -;); +); /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates /// on-chain transactions to ensure no loss of funds occurs. @@ -2731,7 +2756,9 @@ impl<'a, Signer: Sign, K: KeysInterface> ReadableArgs<&'a K> let waiting_threshold_conf_len: u64 = Readable::read(reader)?; let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128)); for _ in 0..waiting_threshold_conf_len { - onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?); + if let Some(val) = MaybeReadable::read(reader)? { + onchain_events_awaiting_threshold_conf.push(val); + } } let outputs_to_watch_len: u64 = Readable::read(reader)?; diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs index 44bbfc2d6..d6777cc5c 100644 --- a/lightning/src/chain/onchaintx.rs +++ b/lightning/src/chain/onchaintx.rs @@ -29,7 +29,7 @@ use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER}; use chain::keysinterface::{Sign, KeysInterface}; use chain::package::PackageTemplate; use util::logger::Logger; -use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter}; +use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter}; use util::byte_utils; use io; @@ -79,20 +79,43 @@ enum OnchainEvent { } } -impl_writeable_tlv_based!(OnchainEventEntry, { - (0, txid, required), - (2, height, required), - (4, event, required), -}); +impl Writeable for OnchainEventEntry { + fn write(&self, writer: &mut W) -> Result<(), io::Error> { + write_tlv_fields!(writer, { + (0, self.txid, required), + (2, self.height, required), + (4, self.event, required), + }); + Ok(()) + } +} + +impl MaybeReadable for OnchainEventEntry { + fn read(reader: &mut R) -> Result, DecodeError> { + let mut txid = Default::default(); + let mut height = 0; + let mut event = None; + read_tlv_fields!(reader, { + (0, txid, required), + (2, height, required), + (4, event, ignorable), + }); + if let Some(ev) = event { + Ok(Some(Self { txid, height, event: ev })) + } else { + Ok(None) + } + } +} -impl_writeable_tlv_based_enum!(OnchainEvent, +impl_writeable_tlv_based_enum_upgradable!(OnchainEvent, (0, Claim) => { (0, claim_request, required), }, (1, ContentiousOutpoint) => { (0, package, required), }, -;); +); impl Readable for Option>> { fn read(reader: &mut R) -> Result { @@ -296,7 +319,9 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler { let waiting_threshold_conf_len: u64 = Readable::read(reader)?; let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128)); for _ in 0..waiting_threshold_conf_len { - onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?); + if let Some(val) = MaybeReadable::read(reader)? { + onchain_events_awaiting_threshold_conf.push(val); + } } read_tlv_fields!(reader, {}); diff --git a/lightning/src/util/ser_macros.rs b/lightning/src/util/ser_macros.rs index e988ad7ee..af1bebe68 100644 --- a/lightning/src/util/ser_macros.rs +++ b/lightning/src/util/ser_macros.rs @@ -115,6 +115,9 @@ macro_rules! check_tlv_order { ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{ // no-op }}; + ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, ignorable) => {{ + // no-op + }}; } macro_rules! check_missing_tlv { @@ -138,6 +141,9 @@ macro_rules! check_missing_tlv { ($last_seen_type: expr, $type: expr, $field: ident, option) => {{ // no-op }}; + ($last_seen_type: expr, $type: expr, $field: ident, ignorable) => {{ + // no-op + }}; } macro_rules! decode_tlv { @@ -153,6 +159,9 @@ macro_rules! decode_tlv { ($reader: expr, $field: ident, option) => {{ $field = Some(ser::Readable::read(&mut $reader)?); }}; + ($reader: expr, $field: ident, ignorable) => {{ + $field = ser::MaybeReadable::read(&mut $reader)?; + }}; } macro_rules! decode_tlv_stream { @@ -405,7 +414,7 @@ macro_rules! init_tlv_field_var { }; ($field: ident, option) => { let mut $field = None; - } + }; } /// Implements Readable/Writeable for a struct storing it as a set of TLVs @@ -458,17 +467,7 @@ macro_rules! impl_writeable_tlv_based { } } -/// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple -/// variants stored directly. -/// The format is, for example -/// impl_writeable_tlv_based_enum!(EnumName, -/// (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)}, -/// (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)}; -/// (2, TupleVariantA), (3, TupleVariantB), -/// ); -/// The type is written as a single byte, followed by any variant data. -/// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature. -macro_rules! impl_writeable_tlv_based_enum { +macro_rules! _impl_writeable_tlv_based_enum_common { ($st: ident, $(($variant_id: expr, $variant_name: ident) => {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} ),* $(,)*; @@ -492,6 +491,72 @@ macro_rules! impl_writeable_tlv_based_enum { Ok(()) } } + } +} + +/// Implement MaybeReadable and Writeable for an enum, with struct variants stored as TLVs and +/// tuple variants stored directly. +/// +/// This is largely identical to `impl_writeable_tlv_based_enum`, except that odd variants will +/// return `Ok(None)` instead of `Err(UnknownRequiredFeature)`. It should generally be preferred +/// when `MaybeReadable` is practical instead of just `Readable` as it provides an upgrade path for +/// new variants to be added which are simply ignored by existing clients. +macro_rules! impl_writeable_tlv_based_enum_upgradable { + ($st: ident, $(($variant_id: expr, $variant_name: ident) => + {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} + ),* $(,)*) => { + _impl_writeable_tlv_based_enum_common!($st, + $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*; ); + + impl ::util::ser::MaybeReadable for $st { + fn read(reader: &mut R) -> Result, ::ln::msgs::DecodeError> { + let id: u8 = ::util::ser::Readable::read(reader)?; + match id { + $($variant_id => { + // Because read_tlv_fields creates a labeled loop, we cannot call it twice + // in the same function body. Instead, we define a closure and call it. + let f = || { + $( + init_tlv_field_var!($field, $fieldty); + )* + read_tlv_fields!(reader, { + $(($type, $field, $fieldty)),* + }); + Ok(Some($st::$variant_name { + $( + $field: init_tlv_based_struct_field!($field, $fieldty) + ),* + })) + }; + f() + }),* + _ if id % 2 == 1 => Ok(None), + _ => Err(DecodeError::UnknownRequiredFeature), + } + } + } + + } +} + +/// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple +/// variants stored directly. +/// The format is, for example +/// impl_writeable_tlv_based_enum!(EnumName, +/// (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)}, +/// (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)}; +/// (2, TupleVariantA), (3, TupleVariantB), +/// ); +/// The type is written as a single byte, followed by any variant data. +/// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature. +macro_rules! impl_writeable_tlv_based_enum { + ($st: ident, $(($variant_id: expr, $variant_name: ident) => + {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} + ),* $(,)*; + $(($tuple_variant_id: expr, $tuple_variant_name: ident)),* $(,)*) => { + _impl_writeable_tlv_based_enum_common!($st, + $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*; + $(($tuple_variant_id, $tuple_variant_name)),*); impl ::util::ser::Readable for $st { fn read(reader: &mut R) -> Result {