rust-libp2p/swarm/src/handler/select.rs

// Copyright 2019 Parity Technologies (UK) Ltd.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

use crate::handler::{
    AddressChange, ConnectionEvent, ConnectionHandler, ConnectionHandlerEvent,
    ConnectionHandlerUpgrErr, DialUpgradeError, FullyNegotiatedInbound, FullyNegotiatedOutbound,
    InboundUpgradeSend, IntoConnectionHandler, KeepAlive, ListenUpgradeError, OutboundUpgradeSend,
    SubstreamProtocol,
};
use crate::upgrade::SendWrapper;

use either::Either;
use libp2p_core::{
    either::{EitherError, EitherOutput},
    upgrade::{EitherUpgrade, NegotiationError, ProtocolError, SelectUpgrade, UpgradeError},
    ConnectedPoint, PeerId,
};
use std::{cmp, task::Context, task::Poll};

/// Implementation of `IntoConnectionHandler` that combines two protocols into one.
#[derive(Debug, Clone)]
pub struct IntoConnectionHandlerSelect<TProto1, TProto2> {
    /// The first protocol.
    proto1: TProto1,
    /// The second protocol.
    proto2: TProto2,
}

impl<TProto1, TProto2> IntoConnectionHandlerSelect<TProto1, TProto2> {
    /// Builds a `IntoConnectionHandlerSelect`.
    pub(crate) fn new(proto1: TProto1, proto2: TProto2) -> Self {
        IntoConnectionHandlerSelect { proto1, proto2 }
    }

    pub fn into_inner(self) -> (TProto1, TProto2) {
        (self.proto1, self.proto2)
    }
}

impl<TProto1, TProto2> IntoConnectionHandler for IntoConnectionHandlerSelect<TProto1, TProto2>
where
    TProto1: IntoConnectionHandler,
    TProto2: IntoConnectionHandler,
{
    type Handler = ConnectionHandlerSelect<TProto1::Handler, TProto2::Handler>;

    fn into_handler(
        self,
        remote_peer_id: &PeerId,
        connected_point: &ConnectedPoint,
    ) -> Self::Handler {
        ConnectionHandlerSelect {
            proto1: self.proto1.into_handler(remote_peer_id, connected_point),
            proto2: self.proto2.into_handler(remote_peer_id, connected_point),
        }
    }

    fn inbound_protocol(&self) -> <Self::Handler as ConnectionHandler>::InboundProtocol {
        SelectUpgrade::new(
            SendWrapper(self.proto1.inbound_protocol()),
            SendWrapper(self.proto2.inbound_protocol()),
        )
    }
}

/// Implementation of [`ConnectionHandler`] that combines two protocols into one.
#[derive(Debug, Clone)]
pub struct ConnectionHandlerSelect<TProto1, TProto2> {
    /// The first protocol.
    proto1: TProto1,
    /// The second protocol.
    proto2: TProto2,
}

impl<TProto1, TProto2> ConnectionHandlerSelect<TProto1, TProto2> {
    /// Builds a [`ConnectionHandlerSelect`].
    pub(crate) fn new(proto1: TProto1, proto2: TProto2) -> Self {
        ConnectionHandlerSelect { proto1, proto2 }
    }

    pub fn into_inner(self) -> (TProto1, TProto2) {
        (self.proto1, self.proto2)
    }
}

impl<S1OOI, S2OOI, S1OP, S2OP>
    FullyNegotiatedOutbound<
        EitherUpgrade<SendWrapper<S1OP>, SendWrapper<S2OP>>,
        EitherOutput<S1OOI, S2OOI>,
    >
where
    S1OP: OutboundUpgradeSend,
    S2OP: OutboundUpgradeSend,
    S1OOI: Send + 'static,
    S2OOI: Send + 'static,
{
    fn transpose(
        self,
    ) -> Either<FullyNegotiatedOutbound<S1OP, S1OOI>, FullyNegotiatedOutbound<S2OP, S2OOI>> {
        match self {
            FullyNegotiatedOutbound {
                protocol: EitherOutput::First(protocol),
                info: EitherOutput::First(info),
            } => Either::Left(FullyNegotiatedOutbound { protocol, info }),
            FullyNegotiatedOutbound {
                protocol: EitherOutput::Second(protocol),
                info: EitherOutput::Second(info),
            } => Either::Right(FullyNegotiatedOutbound { protocol, info }),
            _ => panic!("wrong API usage: the protocol doesn't match the upgrade info"),
        }
    }
}

impl<S1IP, S1IOI, S2IP, S2IOI>
    FullyNegotiatedInbound<SelectUpgrade<SendWrapper<S1IP>, SendWrapper<S2IP>>, (S1IOI, S2IOI)>
where
    S1IP: InboundUpgradeSend,
    S2IP: InboundUpgradeSend,
{
    fn transpose(
        self,
    ) -> Either<FullyNegotiatedInbound<S1IP, S1IOI>, FullyNegotiatedInbound<S2IP, S2IOI>> {
        match self {
            FullyNegotiatedInbound {
                protocol: EitherOutput::First(protocol),
                info: (i1, _i2),
            } => Either::Left(FullyNegotiatedInbound { protocol, info: i1 }),
            FullyNegotiatedInbound {
                protocol: EitherOutput::Second(protocol),
                info: (_i1, i2),
            } => Either::Right(FullyNegotiatedInbound { protocol, info: i2 }),
        }
    }
}

impl<S1OOI, S2OOI, S1OP, S2OP>
    DialUpgradeError<
        EitherOutput<S1OOI, S2OOI>,
        EitherUpgrade<SendWrapper<S1OP>, SendWrapper<S2OP>>,
    >
where
    S1OP: OutboundUpgradeSend,
    S2OP: OutboundUpgradeSend,
    S1OOI: Send + 'static,
    S2OOI: Send + 'static,
{
    fn transpose(self) -> Either<DialUpgradeError<S1OOI, S1OP>, DialUpgradeError<S2OOI, S2OP>> {
        match self {
            DialUpgradeError {
                info: EitherOutput::First(info),
                error: ConnectionHandlerUpgrErr::Timer,
            } => Either::Left(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Timer,
            }),
            DialUpgradeError {
                info: EitherOutput::First(info),
                error: ConnectionHandlerUpgrErr::Timeout,
            } => Either::Left(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Timeout,
            }),
            DialUpgradeError {
                info: EitherOutput::First(info),
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(err)),
            } => Either::Left(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(err)),
            }),
            DialUpgradeError {
                info: EitherOutput::First(info),
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(EitherError::A(err))),
            } => Either::Left(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(err)),
            }),
            DialUpgradeError {
                info: EitherOutput::Second(info),
                error: ConnectionHandlerUpgrErr::Timer,
            } => Either::Right(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Timer,
            }),
            DialUpgradeError {
                info: EitherOutput::Second(info),
                error: ConnectionHandlerUpgrErr::Timeout,
            } => Either::Right(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Timeout,
            }),
            DialUpgradeError {
                info: EitherOutput::Second(info),
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(err)),
            } => Either::Right(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(err)),
            }),
            DialUpgradeError {
                info: EitherOutput::Second(info),
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(EitherError::B(err))),
            } => Either::Right(DialUpgradeError {
                info,
                error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(err)),
            }),
            _ => panic!("Wrong API usage; the upgrade error doesn't match the outbound open info"),
        }
    }
}

impl<TProto1, TProto2> ConnectionHandlerSelect<TProto1, TProto2>
where
    TProto1: ConnectionHandler,
    TProto2: ConnectionHandler,
{
    fn on_listen_upgrade_error(
        &mut self,
        ListenUpgradeError {
            info: (i1, i2),
            error,
        }: ListenUpgradeError<
            <Self as ConnectionHandler>::InboundOpenInfo,
            <Self as ConnectionHandler>::InboundProtocol,
        >,
    ) {
        match error {
            ConnectionHandlerUpgrErr::Timer => {
                self.proto1
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i1,
                        error: ConnectionHandlerUpgrErr::Timer,
                    }));

                self.proto2
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i2,
                        error: ConnectionHandlerUpgrErr::Timer,
                    }));
            }
            ConnectionHandlerUpgrErr::Timeout => {
                self.proto1
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i1,
                        error: ConnectionHandlerUpgrErr::Timeout,
                    }));

                self.proto2
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i2,
                        error: ConnectionHandlerUpgrErr::Timeout,
                    }));
            }
            ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(NegotiationError::Failed)) => {
                self.proto1
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i1,
                        error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(
                            NegotiationError::Failed,
                        )),
                    }));

                self.proto2
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i2,
                        error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(
                            NegotiationError::Failed,
                        )),
                    }));
            }
            ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(
                NegotiationError::ProtocolError(e),
            )) => {
                let (e1, e2);
                match e {
                    ProtocolError::IoError(e) => {
                        e1 = NegotiationError::ProtocolError(ProtocolError::IoError(
                            e.kind().into(),
                        ));
                        e2 = NegotiationError::ProtocolError(ProtocolError::IoError(e))
                    }
                    ProtocolError::InvalidMessage => {
                        e1 = NegotiationError::ProtocolError(ProtocolError::InvalidMessage);
                        e2 = NegotiationError::ProtocolError(ProtocolError::InvalidMessage)
                    }
                    ProtocolError::InvalidProtocol => {
                        e1 = NegotiationError::ProtocolError(ProtocolError::InvalidProtocol);
                        e2 = NegotiationError::ProtocolError(ProtocolError::InvalidProtocol)
                    }
                    ProtocolError::TooManyProtocols => {
                        e1 = NegotiationError::ProtocolError(ProtocolError::TooManyProtocols);
                        e2 = NegotiationError::ProtocolError(ProtocolError::TooManyProtocols)
                    }
                }
                self.proto1
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i1,
                        error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(e1)),
                    }));
                self.proto2
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i2,
                        error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Select(e2)),
                    }));
            }
            ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(EitherError::A(e))) => {
                self.proto1
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i1,
                        error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(e)),
                    }));
            }
            ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(EitherError::B(e))) => {
                self.proto2
                    .on_connection_event(ConnectionEvent::ListenUpgradeError(ListenUpgradeError {
                        info: i2,
                        error: ConnectionHandlerUpgrErr::Upgrade(UpgradeError::Apply(e)),
                    }));
            }
        }
    }
}

impl<TProto1, TProto2> ConnectionHandler for ConnectionHandlerSelect<TProto1, TProto2>
where
    TProto1: ConnectionHandler,
    TProto2: ConnectionHandler,
{
    type InEvent = EitherOutput<TProto1::InEvent, TProto2::InEvent>;
    type OutEvent = EitherOutput<TProto1::OutEvent, TProto2::OutEvent>;
    type Error = EitherError<TProto1::Error, TProto2::Error>;
    type InboundProtocol = SelectUpgrade<
        SendWrapper<<TProto1 as ConnectionHandler>::InboundProtocol>,
        SendWrapper<<TProto2 as ConnectionHandler>::InboundProtocol>,
    >;
    type OutboundProtocol = EitherUpgrade<
        SendWrapper<TProto1::OutboundProtocol>,
        SendWrapper<TProto2::OutboundProtocol>,
    >;
    type OutboundOpenInfo = EitherOutput<TProto1::OutboundOpenInfo, TProto2::OutboundOpenInfo>;
    type InboundOpenInfo = (TProto1::InboundOpenInfo, TProto2::InboundOpenInfo);

    fn listen_protocol(&self) -> SubstreamProtocol<Self::InboundProtocol, Self::InboundOpenInfo> {
        let proto1 = self.proto1.listen_protocol();
        let proto2 = self.proto2.listen_protocol();
        let timeout = *std::cmp::max(proto1.timeout(), proto2.timeout());
        let (u1, i1) = proto1.into_upgrade();
        let (u2, i2) = proto2.into_upgrade();
        let choice = SelectUpgrade::new(SendWrapper(u1), SendWrapper(u2));
        SubstreamProtocol::new(choice, (i1, i2)).with_timeout(timeout)
    }

    fn on_behaviour_event(&mut self, event: Self::InEvent) {
        match event {
            EitherOutput::First(event) => self.proto1.on_behaviour_event(event),
            EitherOutput::Second(event) => self.proto2.on_behaviour_event(event),
        }
    }

    fn connection_keep_alive(&self) -> KeepAlive {
        cmp::max(
            self.proto1.connection_keep_alive(),
            self.proto2.connection_keep_alive(),
        )
    }

    fn poll(
        &mut self,
        cx: &mut Context<'_>,
    ) -> Poll<
        ConnectionHandlerEvent<
            Self::OutboundProtocol,
            Self::OutboundOpenInfo,
            Self::OutEvent,
            Self::Error,
        >,
    > {
        match self.proto1.poll(cx) {
            Poll::Ready(ConnectionHandlerEvent::Custom(event)) => {
                return Poll::Ready(ConnectionHandlerEvent::Custom(EitherOutput::First(event)));
            }
            Poll::Ready(ConnectionHandlerEvent::Close(event)) => {
                return Poll::Ready(ConnectionHandlerEvent::Close(EitherError::A(event)));
            }
            Poll::Ready(ConnectionHandlerEvent::OutboundSubstreamRequest { protocol }) => {
                return Poll::Ready(ConnectionHandlerEvent::OutboundSubstreamRequest {
                    protocol: protocol
                        .map_upgrade(|u| EitherUpgrade::A(SendWrapper(u)))
                        .map_info(EitherOutput::First),
                });
            }
            Poll::Pending => (),
        };

        match self.proto2.poll(cx) {
            Poll::Ready(ConnectionHandlerEvent::Custom(event)) => {
                return Poll::Ready(ConnectionHandlerEvent::Custom(EitherOutput::Second(event)));
            }
            Poll::Ready(ConnectionHandlerEvent::Close(event)) => {
                return Poll::Ready(ConnectionHandlerEvent::Close(EitherError::B(event)));
            }
            Poll::Ready(ConnectionHandlerEvent::OutboundSubstreamRequest { protocol }) => {
                return Poll::Ready(ConnectionHandlerEvent::OutboundSubstreamRequest {
                    protocol: protocol
                        .map_upgrade(|u| EitherUpgrade::B(SendWrapper(u)))
                        .map_info(EitherOutput::Second),
                });
            }
            Poll::Pending => (),
        };

        Poll::Pending
    }

    fn on_connection_event(
        &mut self,
        event: ConnectionEvent<
            Self::InboundProtocol,
            Self::OutboundProtocol,
            Self::InboundOpenInfo,
            Self::OutboundOpenInfo,
        >,
    ) {
        match event {
            ConnectionEvent::FullyNegotiatedOutbound(fully_negotiated_outbound) => {
                match fully_negotiated_outbound.transpose() {
                    Either::Left(f) => self
                        .proto1
                        .on_connection_event(ConnectionEvent::FullyNegotiatedOutbound(f)),
                    Either::Right(f) => self
                        .proto2
                        .on_connection_event(ConnectionEvent::FullyNegotiatedOutbound(f)),
                }
            }
            ConnectionEvent::FullyNegotiatedInbound(fully_negotiated_inbound) => {
                match fully_negotiated_inbound.transpose() {
                    Either::Left(f) => self
                        .proto1
                        .on_connection_event(ConnectionEvent::FullyNegotiatedInbound(f)),
                    Either::Right(f) => self
                        .proto2
                        .on_connection_event(ConnectionEvent::FullyNegotiatedInbound(f)),
                }
            }
            ConnectionEvent::AddressChange(address) => {
                self.proto1
                    .on_connection_event(ConnectionEvent::AddressChange(AddressChange {
                        new_address: address.new_address,
                    }));

                self.proto2
                    .on_connection_event(ConnectionEvent::AddressChange(AddressChange {
                        new_address: address.new_address,
                    }));
            }
            ConnectionEvent::DialUpgradeError(dial_upgrade_error) => {
                match dial_upgrade_error.transpose() {
                    Either::Left(err) => self
                        .proto1
                        .on_connection_event(ConnectionEvent::DialUpgradeError(err)),
                    Either::Right(err) => self
                        .proto2
                        .on_connection_event(ConnectionEvent::DialUpgradeError(err)),
                }
            }
            ConnectionEvent::ListenUpgradeError(listen_upgrade_error) => {
                self.on_listen_upgrade_error(listen_upgrade_error)
            }
        }
    }
}