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use crate::v2::message_proto::{stop_message, Limit, Peer, Status, StopMessage};
use crate::v2::protocol::{MAX_MESSAGE_SIZE, STOP_PROTOCOL_NAME};
use asynchronous_codec::{Framed, FramedParts};
use bytes::Bytes;
use futures::{future::BoxFuture, prelude::*};
use libp2p_core::{upgrade, PeerId};
use libp2p_swarm::NegotiatedSubstream;
use std::convert::TryInto;
use std::iter;
use std::time::Duration;
use thiserror::Error;
pub struct Upgrade {
pub relay_peer_id: PeerId,
pub max_circuit_duration: Duration,
pub max_circuit_bytes: u64,
}
impl upgrade::UpgradeInfo for Upgrade {
type Info = &'static [u8];
type InfoIter = iter::Once<Self::Info>;
fn protocol_info(&self) -> Self::InfoIter {
iter::once(STOP_PROTOCOL_NAME)
}
}
impl upgrade::OutboundUpgrade<NegotiatedSubstream> for Upgrade {
type Output = (NegotiatedSubstream, Bytes);
type Error = UpgradeError;
type Future = BoxFuture<'static, Result<Self::Output, Self::Error>>;
fn upgrade_outbound(self, substream: NegotiatedSubstream, _: Self::Info) -> Self::Future {
let msg = StopMessage {
r#type: stop_message::Type::Connect.into(),
peer: Some(Peer {
id: self.relay_peer_id.to_bytes(),
addrs: vec![],
}),
limit: Some(Limit {
duration: Some(
self.max_circuit_duration
.as_secs()
.try_into()
.expect("`max_circuit_duration` not to exceed `u32::MAX`."),
),
data: Some(self.max_circuit_bytes),
}),
status: None,
};
let mut substream = Framed::new(substream, prost_codec::Codec::new(MAX_MESSAGE_SIZE));
async move {
substream.send(msg).await?;
let StopMessage {
r#type,
peer: _,
limit: _,
status,
} = substream
.next()
.await
.ok_or(FatalUpgradeError::StreamClosed)??;
let r#type =
stop_message::Type::from_i32(r#type).ok_or(FatalUpgradeError::ParseTypeField)?;
match r#type {
stop_message::Type::Connect => {
return Err(FatalUpgradeError::UnexpectedTypeConnect.into())
}
stop_message::Type::Status => {}
}
let status = Status::from_i32(status.ok_or(FatalUpgradeError::MissingStatusField)?)
.ok_or(FatalUpgradeError::ParseStatusField)?;
match status {
Status::Ok => {}
Status::ResourceLimitExceeded => {
return Err(CircuitFailedReason::ResourceLimitExceeded.into())
}
Status::PermissionDenied => {
return Err(CircuitFailedReason::PermissionDenied.into())
}
s => return Err(FatalUpgradeError::UnexpectedStatus(s).into()),
}
let FramedParts {
io,
read_buffer,
write_buffer,
..
} = substream.into_parts();
assert!(
write_buffer.is_empty(),
"Expect a flushed Framed to have an empty write buffer."
);
Ok((io, read_buffer.freeze()))
}
.boxed()
}
}
#[derive(Debug, Error)]
pub enum UpgradeError {
#[error("Circuit failed")]
CircuitFailed(#[from] CircuitFailedReason),
#[error("Fatal")]
Fatal(#[from] FatalUpgradeError),
}
impl From<prost_codec::Error> for UpgradeError {
fn from(error: prost_codec::Error) -> Self {
Self::Fatal(error.into())
}
}
#[derive(Debug, Error)]
pub enum CircuitFailedReason {
#[error("Remote reported resource limit exceeded.")]
ResourceLimitExceeded,
#[error("Remote reported permission denied.")]
PermissionDenied,
}
#[derive(Debug, Error)]
pub enum FatalUpgradeError {
#[error(transparent)]
Codec(#[from] prost_codec::Error),
#[error("Stream closed")]
StreamClosed,
#[error("Expected 'status' field to be set.")]
MissingStatusField,
#[error("Failed to parse response type field.")]
ParseTypeField,
#[error("Unexpected message type 'connect'")]
UnexpectedTypeConnect,
#[error("Failed to parse response type field.")]
ParseStatusField,
#[error("Unexpected message status '{0:?}'")]
UnexpectedStatus(Status),
}