_ Git - rust-lightning/blob - lightning/src/onion_message/offers.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Message handling for BOLT 12 Offers.
  11
  12 use core::convert::TryFrom;
  13 use crate::io::{self, Read};
  14 use crate::ln::msgs::DecodeError;
  15 use crate::offers::invoice_error::InvoiceError;
  16 use crate::offers::invoice_request::InvoiceRequest;
  17 use crate::offers::invoice::Bolt12Invoice;
  18 use crate::offers::parse::Bolt12ParseError;
  19 use crate::onion_message::OnionMessageContents;
  20 use crate::util::logger::Logger;
  21 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
  22
  23 use crate::prelude::*;
  24
  25 // TLV record types for the `onionmsg_tlv` TLV stream as defined in BOLT 4.
  26 const INVOICE_REQUEST_TLV_TYPE: u64 = 64;
  27 const INVOICE_TLV_TYPE: u64 = 66;
  28 const INVOICE_ERROR_TLV_TYPE: u64 = 68;
  29
  30 /// A handler for an [`OnionMessage`] containing a BOLT 12 Offers message as its payload.
  31 ///
  32 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  33 pub trait OffersMessageHandler {
  34         /// Handles the given message by either responding with an [`Bolt12Invoice`], sending a payment,
  35         /// or replying with an error.
  36         fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage>;
  37 }
  38
  39 /// Possible BOLT 12 Offers messages sent and received via an [`OnionMessage`].
  40 ///
  41 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  42 #[derive(Clone, Debug)]
  43 pub enum OffersMessage {
  44         /// A request for a [`Bolt12Invoice`] for a particular [`Offer`].
  45         ///
  46         /// [`Offer`]: crate::offers::offer::Offer
  47         InvoiceRequest(InvoiceRequest),
  48
  49         /// A [`Bolt12Invoice`] sent in response to an [`InvoiceRequest`] or a [`Refund`].
  50         ///
  51         /// [`Refund`]: crate::offers::refund::Refund
  52         Invoice(Bolt12Invoice),
  53
  54         /// An error from handling an [`OffersMessage`].
  55         InvoiceError(InvoiceError),
  56 }
  57
  58 impl OffersMessage {
  59         /// Returns whether `tlv_type` corresponds to a TLV record for Offers.
  60         pub fn is_known_type(tlv_type: u64) -> bool {
  61                 match tlv_type {
  62                         INVOICE_REQUEST_TLV_TYPE | INVOICE_TLV_TYPE | INVOICE_ERROR_TLV_TYPE => true,
  63                         _ => false,
  64                 }
  65         }
  66
  67         fn parse(tlv_type: u64, bytes: Vec<u8>) -> Result<Self, Bolt12ParseError> {
  68                 match tlv_type {
  69                         INVOICE_REQUEST_TLV_TYPE => Ok(Self::InvoiceRequest(InvoiceRequest::try_from(bytes)?)),
  70                         INVOICE_TLV_TYPE => Ok(Self::Invoice(Bolt12Invoice::try_from(bytes)?)),
  71                         _ => Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
  72                 }
  73         }
  74 }
  75
  76 impl OnionMessageContents for OffersMessage {
  77         fn tlv_type(&self) -> u64 {
  78                 match self {
  79                         OffersMessage::InvoiceRequest(_) => INVOICE_REQUEST_TLV_TYPE,
  80                         OffersMessage::Invoice(_) => INVOICE_TLV_TYPE,
  81                         OffersMessage::InvoiceError(_) => INVOICE_ERROR_TLV_TYPE,
  82                 }
  83         }
  84 }
  85
  86 impl Writeable for OffersMessage {
  87         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
  88                 match self {
  89                         OffersMessage::InvoiceRequest(message) => message.write(w),
  90                         OffersMessage::Invoice(message) => message.write(w),
  91                         OffersMessage::InvoiceError(message) => message.write(w),
  92                 }
  93         }
  94 }
  95
  96 impl<L: Logger + ?Sized> ReadableArgs<(u64, &L)> for OffersMessage {
  97         fn read<R: Read>(r: &mut R, read_args: (u64, &L)) -> Result<Self, DecodeError> {
  98                 let (tlv_type, logger) = read_args;
  99                 if tlv_type == INVOICE_ERROR_TLV_TYPE {
 100                         return Ok(Self::InvoiceError(InvoiceError::read(r)?));
 101                 }
 102
 103                 let mut bytes = Vec::new();
 104                 r.read_to_end(&mut bytes).unwrap();
 105
 106                 match Self::parse(tlv_type, bytes) {
 107                         Ok(message) => Ok(message),
 108                         Err(Bolt12ParseError::Decode(e)) => Err(e),
 109                         Err(Bolt12ParseError::InvalidSemantics(e)) => {
 110                                 log_trace!(logger, "Invalid semantics for TLV type {}: {:?}", tlv_type, e);
 111                                 Err(DecodeError::InvalidValue)
 112                         },
 113                         Err(Bolt12ParseError::InvalidSignature(e)) => {
 114                                 log_trace!(logger, "Invalid signature for TLV type {}: {:?}", tlv_type, e);
 115                                 Err(DecodeError::InvalidValue)
 116                         },
 117                         Err(_) => Err(DecodeError::InvalidValue),
 118                 }
 119         }
 120 }