+ Self { payment_secret: None, payment_metadata: None, custom_tlvs: Vec::new() }
+ }
+
+ /// Creates a new [`RecipientOnionFields`] from an existing one, adding custom TLVs. Each
+ /// TLV is provided as a `(u64, Vec<u8>)` for the type number and serialized value
+ /// respectively. TLV type numbers must be unique and within the range
+ /// reserved for custom types, i.e. >= 2^16, otherwise this method will return `Err(())`.
+ ///
+ /// This method will also error for types in the experimental range which have been
+ /// standardized within the protocol, which only includes 5482373484 (keysend) for now.
+ ///
+ /// See [`Self::custom_tlvs`] for more info.
+ pub fn with_custom_tlvs(mut self, mut custom_tlvs: Vec<(u64, Vec<u8>)>) -> Result<Self, ()> {
+ custom_tlvs.sort_unstable_by_key(|(typ, _)| *typ);
+ let mut prev_type = None;
+ for (typ, _) in custom_tlvs.iter() {
+ if *typ < 1 << 16 { return Err(()); }
+ if *typ == 5482373484 { return Err(()); } // keysend
+ match prev_type {
+ Some(prev) if prev >= *typ => return Err(()),
+ _ => {},
+ }
+ prev_type = Some(*typ);
+ }
+ self.custom_tlvs = custom_tlvs;
+ Ok(self)
+ }
+
+ /// Gets the custom TLVs that will be sent or have been received.
+ ///
+ /// Custom TLVs allow sending extra application-specific data with a payment. They provide
+ /// additional flexibility on top of payment metadata, as while other implementations may
+ /// require `payment_metadata` to reflect metadata provided in an invoice, custom TLVs
+ /// do not have this restriction.
+ ///
+ /// Note that if this field is non-empty, it will contain strictly increasing TLVs, each
+ /// represented by a `(u64, Vec<u8>)` for its type number and serialized value respectively.
+ /// This is validated when setting this field using [`Self::with_custom_tlvs`].
+ pub fn custom_tlvs(&self) -> &Vec<(u64, Vec<u8>)> {
+ &self.custom_tlvs