_ 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 core::fmt;
  14 use crate::io::{self, Read};
  15 use crate::ln::msgs::DecodeError;
  16 use crate::offers::invoice_error::InvoiceError;
  17 use crate::offers::invoice_request::InvoiceRequest;
  18 use crate::offers::invoice::Bolt12Invoice;
  19 use crate::offers::parse::Bolt12ParseError;
  20 use crate::onion_message::OnionMessageContents;
  21 use crate::onion_message::messenger::PendingOnionMessage;
  22 use crate::util::logger::Logger;
  23 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
  24
  25 use crate::prelude::*;
  26
  27 // TLV record types for the `onionmsg_tlv` TLV stream as defined in BOLT 4.
  28 const INVOICE_REQUEST_TLV_TYPE: u64 = 64;
  29 const INVOICE_TLV_TYPE: u64 = 66;
  30 const INVOICE_ERROR_TLV_TYPE: u64 = 68;
  31
  32 /// A handler for an [`OnionMessage`] containing a BOLT 12 Offers message as its payload.
  33 ///
  34 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  35 pub trait OffersMessageHandler {
  36         /// Handles the given message by either responding with an [`Bolt12Invoice`], sending a payment,
  37         /// or replying with an error.
  38         ///
  39         /// The returned [`OffersMessage`], if any, is enqueued to be sent by [`OnionMessenger`].
  40         ///
  41         /// [`OnionMessenger`]: crate::onion_message::OnionMessenger
  42         fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage>;
  43
  44         /// Releases any [`OffersMessage`]s that need to be sent.
  45         ///
  46         /// Typically, this is used for messages initiating a payment flow rather than in response to
  47         /// another message. The latter should use the return value of [`Self::handle_message`].
  48         #[cfg(not(c_bindings))]
  49         fn release_pending_messages(&self) -> Vec<PendingOnionMessage<OffersMessage>> { vec![] }
  50
  51         /// Releases any [`OffersMessage`]s that need to be sent.
  52         ///
  53         /// Typically, this is used for messages initiating a payment flow rather than in response to
  54         /// another message. The latter should use the return value of [`Self::handle_message`].
  55         #[cfg(c_bindings)]
  56         fn release_pending_messages(&self) -> Vec<(OffersMessage, crate::onion_message::Destination, Option<crate::blinded_path::BlindedPath>)> { vec![] }
  57 }
  58
  59 /// Possible BOLT 12 Offers messages sent and received via an [`OnionMessage`].
  60 ///
  61 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  62 #[derive(Clone)]
  63 pub enum OffersMessage {
  64         /// A request for a [`Bolt12Invoice`] for a particular [`Offer`].
  65         ///
  66         /// [`Offer`]: crate::offers::offer::Offer
  67         InvoiceRequest(InvoiceRequest),
  68
  69         /// A [`Bolt12Invoice`] sent in response to an [`InvoiceRequest`] or a [`Refund`].
  70         ///
  71         /// [`Refund`]: crate::offers::refund::Refund
  72         Invoice(Bolt12Invoice),
  73
  74         /// An error from handling an [`OffersMessage`].
  75         InvoiceError(InvoiceError),
  76 }
  77
  78 impl OffersMessage {
  79         /// Returns whether `tlv_type` corresponds to a TLV record for Offers.
  80         pub fn is_known_type(tlv_type: u64) -> bool {
  81                 match tlv_type {
  82                         INVOICE_REQUEST_TLV_TYPE | INVOICE_TLV_TYPE | INVOICE_ERROR_TLV_TYPE => true,
  83                         _ => false,
  84                 }
  85         }
  86
  87         fn parse(tlv_type: u64, bytes: Vec<u8>) -> Result<Self, Bolt12ParseError> {
  88                 match tlv_type {
  89                         INVOICE_REQUEST_TLV_TYPE => Ok(Self::InvoiceRequest(InvoiceRequest::try_from(bytes)?)),
  90                         INVOICE_TLV_TYPE => Ok(Self::Invoice(Bolt12Invoice::try_from(bytes)?)),
  91                         _ => Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
  92                 }
  93         }
  94 }
  95
  96 impl fmt::Debug for OffersMessage {
  97         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  98                 match self {
  99                         OffersMessage::InvoiceRequest(message) => {
 100                                 write!(f, "{:?}", message.as_tlv_stream())
 101                         }
 102                         OffersMessage::Invoice(message) => {
 103                                 write!(f, "{:?}", message.as_tlv_stream())
 104                         }
 105                         OffersMessage::InvoiceError(message) => {
 106                                 write!(f, "{:?}", message)
 107                         }
 108                 }
 109         }
 110 }
 111
 112 impl OnionMessageContents for OffersMessage {
 113         fn tlv_type(&self) -> u64 {
 114                 match self {
 115                         OffersMessage::InvoiceRequest(_) => INVOICE_REQUEST_TLV_TYPE,
 116                         OffersMessage::Invoice(_) => INVOICE_TLV_TYPE,
 117                         OffersMessage::InvoiceError(_) => INVOICE_ERROR_TLV_TYPE,
 118                 }
 119         }
 120 }
 121
 122 impl Writeable for OffersMessage {
 123         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 124                 match self {
 125                         OffersMessage::InvoiceRequest(message) => message.write(w),
 126                         OffersMessage::Invoice(message) => message.write(w),
 127                         OffersMessage::InvoiceError(message) => message.write(w),
 128                 }
 129         }
 130 }
 131
 132 impl<L: Logger + ?Sized> ReadableArgs<(u64, &L)> for OffersMessage {
 133         fn read<R: Read>(r: &mut R, read_args: (u64, &L)) -> Result<Self, DecodeError> {
 134                 let (tlv_type, logger) = read_args;
 135                 if tlv_type == INVOICE_ERROR_TLV_TYPE {
 136                         return Ok(Self::InvoiceError(InvoiceError::read(r)?));
 137                 }
 138
 139                 let mut bytes = Vec::new();
 140                 r.read_to_end(&mut bytes).unwrap();
 141
 142                 match Self::parse(tlv_type, bytes) {
 143                         Ok(message) => Ok(message),
 144                         Err(Bolt12ParseError::Decode(e)) => Err(e),
 145                         Err(Bolt12ParseError::InvalidSemantics(e)) => {
 146                                 log_trace!(logger, "Invalid semantics for TLV type {}: {:?}", tlv_type, e);
 147                                 Err(DecodeError::InvalidValue)
 148                         },
 149                         Err(Bolt12ParseError::InvalidSignature(e)) => {
 150                                 log_trace!(logger, "Invalid signature for TLV type {}: {:?}", tlv_type, e);
 151                                 Err(DecodeError::InvalidValue)
 152                         },
 153                         Err(_) => Err(DecodeError::InvalidValue),
 154                 }
 155         }
 156 }