_ 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::packet::OnionMessageContents;
  21 use crate::util::logger::Logger;
  22 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
  23 #[cfg(not(c_bindings))]
  24 use crate::onion_message::messenger::PendingOnionMessage;
  25
  26 use crate::prelude::*;
  27
  28 // TLV record types for the `onionmsg_tlv` TLV stream as defined in BOLT 4.
  29 const INVOICE_REQUEST_TLV_TYPE: u64 = 64;
  30 const INVOICE_TLV_TYPE: u64 = 66;
  31 const INVOICE_ERROR_TLV_TYPE: u64 = 68;
  32
  33 /// A handler for an [`OnionMessage`] containing a BOLT 12 Offers message as its payload.
  34 ///
  35 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  36 pub trait OffersMessageHandler {
  37         /// Handles the given message by either responding with an [`Bolt12Invoice`], sending a payment,
  38         /// or replying with an error.
  39         ///
  40         /// The returned [`OffersMessage`], if any, is enqueued to be sent by [`OnionMessenger`].
  41         ///
  42         /// [`OnionMessenger`]: crate::onion_message::messenger::OnionMessenger
  43         fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage>;
  44
  45         /// Releases any [`OffersMessage`]s that need to be sent.
  46         ///
  47         /// Typically, this is used for messages initiating a payment flow rather than in response to
  48         /// another message. The latter should use the return value of [`Self::handle_message`].
  49         #[cfg(not(c_bindings))]
  50         fn release_pending_messages(&self) -> Vec<PendingOnionMessage<OffersMessage>> { vec![] }
  51
  52         /// Releases any [`OffersMessage`]s that need to be sent.
  53         ///
  54         /// Typically, this is used for messages initiating a payment flow rather than in response to
  55         /// another message. The latter should use the return value of [`Self::handle_message`].
  56         #[cfg(c_bindings)]
  57         fn release_pending_messages(&self) -> Vec<(OffersMessage, crate::onion_message::messenger::Destination, Option<crate::blinded_path::BlindedPath>)> { vec![] }
  58 }
  59
  60 /// Possible BOLT 12 Offers messages sent and received via an [`OnionMessage`].
  61 ///
  62 /// [`OnionMessage`]: crate::ln::msgs::OnionMessage
  63 #[derive(Clone)]
  64 pub enum OffersMessage {
  65         /// A request for a [`Bolt12Invoice`] for a particular [`Offer`].
  66         ///
  67         /// [`Offer`]: crate::offers::offer::Offer
  68         InvoiceRequest(InvoiceRequest),
  69
  70         /// A [`Bolt12Invoice`] sent in response to an [`InvoiceRequest`] or a [`Refund`].
  71         ///
  72         /// [`Refund`]: crate::offers::refund::Refund
  73         Invoice(Bolt12Invoice),
  74
  75         /// An error from handling an [`OffersMessage`].
  76         InvoiceError(InvoiceError),
  77 }
  78
  79 impl OffersMessage {
  80         /// Returns whether `tlv_type` corresponds to a TLV record for Offers.
  81         pub fn is_known_type(tlv_type: u64) -> bool {
  82                 match tlv_type {
  83                         INVOICE_REQUEST_TLV_TYPE | INVOICE_TLV_TYPE | INVOICE_ERROR_TLV_TYPE => true,
  84                         _ => false,
  85                 }
  86         }
  87
  88         fn parse(tlv_type: u64, bytes: Vec<u8>) -> Result<Self, Bolt12ParseError> {
  89                 match tlv_type {
  90                         INVOICE_REQUEST_TLV_TYPE => Ok(Self::InvoiceRequest(InvoiceRequest::try_from(bytes)?)),
  91                         INVOICE_TLV_TYPE => Ok(Self::Invoice(Bolt12Invoice::try_from(bytes)?)),
  92                         _ => Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
  93                 }
  94         }
  95 }
  96
  97 impl fmt::Debug for OffersMessage {
  98         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  99                 match self {
 100                         OffersMessage::InvoiceRequest(message) => {
 101                                 write!(f, "{:?}", message.as_tlv_stream())
 102                         }
 103                         OffersMessage::Invoice(message) => {
 104                                 write!(f, "{:?}", message.as_tlv_stream())
 105                         }
 106                         OffersMessage::InvoiceError(message) => {
 107                                 write!(f, "{:?}", message)
 108                         }
 109                 }
 110         }
 111 }
 112
 113 impl OnionMessageContents for OffersMessage {
 114         fn tlv_type(&self) -> u64 {
 115                 match self {
 116                         OffersMessage::InvoiceRequest(_) => INVOICE_REQUEST_TLV_TYPE,
 117                         OffersMessage::Invoice(_) => INVOICE_TLV_TYPE,
 118                         OffersMessage::InvoiceError(_) => INVOICE_ERROR_TLV_TYPE,
 119                 }
 120         }
 121 }
 122
 123 impl Writeable for OffersMessage {
 124         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 125                 match self {
 126                         OffersMessage::InvoiceRequest(message) => message.write(w),
 127                         OffersMessage::Invoice(message) => message.write(w),
 128                         OffersMessage::InvoiceError(message) => message.write(w),
 129                 }
 130         }
 131 }
 132
 133 impl<L: Logger + ?Sized> ReadableArgs<(u64, &L)> for OffersMessage {
 134         fn read<R: Read>(r: &mut R, read_args: (u64, &L)) -> Result<Self, DecodeError> {
 135                 let (tlv_type, logger) = read_args;
 136                 if tlv_type == INVOICE_ERROR_TLV_TYPE {
 137                         return Ok(Self::InvoiceError(InvoiceError::read(r)?));
 138                 }
 139
 140                 let mut bytes = Vec::new();
 141                 r.read_to_end(&mut bytes).unwrap();
 142
 143                 match Self::parse(tlv_type, bytes) {
 144                         Ok(message) => Ok(message),
 145                         Err(Bolt12ParseError::Decode(e)) => Err(e),
 146                         Err(Bolt12ParseError::InvalidSemantics(e)) => {
 147                                 log_trace!(logger, "Invalid semantics for TLV type {}: {:?}", tlv_type, e);
 148                                 Err(DecodeError::InvalidValue)
 149                         },
 150                         Err(Bolt12ParseError::InvalidSignature(e)) => {
 151                                 log_trace!(logger, "Invalid signature for TLV type {}: {:?}", tlv_type, e);
 152                                 Err(DecodeError::InvalidValue)
 153                         },
 154                         Err(_) => Err(DecodeError::InvalidValue),
 155                 }
 156         }
 157 }