// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// OpenEthereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

//! Connection filter trait.

use super::NodeId;

/// Filtered connection direction.
pub enum ConnectionDirection {
    Inbound,
    Outbound,
}

/// Connection filter. Each connection is checked against `connection_allowed`.
pub trait ConnectionFilter: Send + Sync {
    /// Filter a connection. Returns `true` if connection should be allowed. `false` if rejected.
    fn connection_allowed(
        &self,
        own_id: &NodeId,
        connecting_id: &NodeId,
        direction: ConnectionDirection,
    ) -> bool;
}
