From 2a8179edb79268b6804417f07f55706b23354097 Mon Sep 17 00:00:00 2001 From: Valentine Wallace Date: Mon, 17 Oct 2022 16:07:40 -0400 Subject: [PATCH] Optionally parameterize decode_tlv_stream with custom decode closure Useful for decoding custom or user-provided TLVs. See macro docs for more info. Used in upcoming commit(s) to support custom onion message TLVs --- lightning/src/util/ser_macros.rs | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/lightning/src/util/ser_macros.rs b/lightning/src/util/ser_macros.rs index 782c0ef27..8c0a38670 100644 --- a/lightning/src/util/ser_macros.rs +++ b/lightning/src/util/ser_macros.rs @@ -174,8 +174,13 @@ macro_rules! decode_tlv { }}; } +// `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types. +// If it is provided, it will be called with the custom type and the `FixedLengthReader` containing +// the message contents. It should return `Ok(true)` if the custom message is successfully parsed, +// `Ok(false)` if the message type is unknown, and `Err(DecodeError)` if parsing fails. macro_rules! decode_tlv_stream { - ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { { + ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} + $(, $decode_custom_tlv: expr)?) => { { use ln::msgs::DecodeError; let mut last_seen_type: Option = None; let mut stream_ref = $stream; @@ -226,10 +231,19 @@ macro_rules! decode_tlv_stream { return Err(DecodeError::InvalidValue); } },)* - x if x % 2 == 0 => { - return Err(DecodeError::UnknownRequiredFeature); - }, - _ => {}, + t => { + $( + if $decode_custom_tlv(t, &mut s)? { + // If a custom TLV was successfully read (i.e. decode_custom_tlv returns true), + // continue to the next TLV read. + s.eat_remaining()?; + continue 'tlv_read; + } + )? + if t % 2 == 0 { + return Err(DecodeError::UnknownRequiredFeature); + } + } } s.eat_remaining()?; } -- 2.39.5