_ 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::Invoice;
  18 use crate::offers::parse::ParseError;
  19 use crate::util::logger::Logger;
  20 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
  21
  22 use crate::prelude::*;
  23
  24 // TLV record types for the `onionmsg_tlv` TLV stream as defined in BOLT 4.
  25 const INVOICE_REQUEST_TLV_TYPE: u64 = 64;
  26 const INVOICE_TLV_TYPE: u64 = 66;
  27 const INVOICE_ERROR_TLV_TYPE: u64 = 68;
  28
  29 /// A handler for an [`OnionMessage`] containing a BOLT 12 Offers message as its payload.
  30 ///
  31 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  32 pub trait OffersMessageHandler {
  33         /// Handles the given message by either responding with an [`Invoice`], sending a payment, or
  34         /// replying with an error.
  35         fn handle_message(&self, message: OffersMessage);
  36 }
  37
  38 /// Possible BOLT 12 Offers messages sent and received via an [`OnionMessage`].
  39 ///
  40 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  41 #[derive(Debug)]
  42 pub enum OffersMessage {
  43         /// A request for an [`Invoice`] for a particular [`Offer`].
  44         ///
  45         /// [`Offer`]: crate::offers::offer::Offer
  46         InvoiceRequest(InvoiceRequest),
  47
  48         /// An [`Invoice`] sent in response to an [`InvoiceRequest`] or a [`Refund`].
  49         ///
  50         /// [`Refund`]: crate::offers::refund::Refund
  51         Invoice(Invoice),
  52
  53         /// An error from handling an [`OffersMessage`].
  54         InvoiceError(InvoiceError),
  55 }
  56
  57 impl OffersMessage {
  58         /// Returns whether `tlv_type` corresponds to a TLV record for Offers.
  59         pub fn is_known_type(tlv_type: u64) -> bool {
  60                 match tlv_type {
  61                         INVOICE_REQUEST_TLV_TYPE | INVOICE_TLV_TYPE | INVOICE_ERROR_TLV_TYPE => true,
  62                         _ => false,
  63                 }
  64         }
  65
  66         /// The TLV record type for the message as used in an `onionmsg_tlv` TLV stream.
  67         pub fn tlv_type(&self) -> u64 {
  68                 match self {
  69                         OffersMessage::InvoiceRequest(_) => INVOICE_REQUEST_TLV_TYPE,
  70                         OffersMessage::Invoice(_) => INVOICE_TLV_TYPE,
  71                         OffersMessage::InvoiceError(_) => INVOICE_ERROR_TLV_TYPE,
  72                 }
  73         }
  74
  75         fn parse(tlv_type: u64, bytes: Vec<u8>) -> Result<Self, ParseError> {
  76                 match tlv_type {
  77                         INVOICE_REQUEST_TLV_TYPE => Ok(Self::InvoiceRequest(InvoiceRequest::try_from(bytes)?)),
  78                         INVOICE_TLV_TYPE => Ok(Self::Invoice(Invoice::try_from(bytes)?)),
  79                         _ => Err(ParseError::Decode(DecodeError::InvalidValue)),
  80                 }
  81         }
  82 }
  83
  84 impl Writeable for OffersMessage {
  85         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
  86                 match self {
  87                         OffersMessage::InvoiceRequest(message) => message.write(w),
  88                         OffersMessage::Invoice(message) => message.write(w),
  89                         OffersMessage::InvoiceError(message) => message.write(w),
  90                 }
  91         }
  92 }
  93
  94 impl<L: Logger + ?Sized> ReadableArgs<(u64, &L)> for OffersMessage {
  95         fn read<R: Read>(r: &mut R, read_args: (u64, &L)) -> Result<Self, DecodeError> {
  96                 let (tlv_type, logger) = read_args;
  97                 if tlv_type == INVOICE_ERROR_TLV_TYPE {
  98                         return Ok(Self::InvoiceError(InvoiceError::read(r)?));
  99                 }
 100
 101                 let mut bytes = Vec::new();
 102                 r.read_to_end(&mut bytes).unwrap();
 103
 104                 match Self::parse(tlv_type, bytes) {
 105                         Ok(message) => Ok(message),
 106                         Err(ParseError::Decode(e)) => Err(e),
 107                         Err(ParseError::InvalidSemantics(e)) => {
 108                                 log_trace!(logger, "Invalid semantics for TLV type {}: {:?}", tlv_type, e);
 109                                 Err(DecodeError::InvalidValue)
 110                         },
 111                         Err(ParseError::InvalidSignature(e)) => {
 112                                 log_trace!(logger, "Invalid signature for TLV type {}: {:?}", tlv_type, e);
 113                                 Err(DecodeError::InvalidValue)
 114                         },
 115                         Err(_) => Err(DecodeError::InvalidValue),
 116                 }
 117         }
 118 }