tari_comms 5.7.0-pre.4

// Copyright 2023, The Tari Project
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use std::time::Duration;

use crate::{bans::BAN_DURATION_LONG, peer_manager::NodeId};

/// Validation errors for peers shared on the network
#[derive(Debug, Clone, thiserror::Error)]
pub enum PeerValidatorError {
    #[error("Peer signature was invalid for peer '{peer}'")]
    InvalidPeerSignature { peer: NodeId },
    #[error("One or more peer addresses were invalid for '{peer}'")]
    InvalidPeerAddresses { peer: NodeId },
    #[error("Peer '{peer}' has no address claims")]
    PeerHasNoAddresses { peer: NodeId },
    #[error("Peer '{peer}' has address claims, but none are usable")]
    PeerHasNoUsableAddresses { peer: NodeId },
    #[error("Invalid multiaddr: {0}")]
    InvalidMultiaddr(String),
    #[error("Onion v2 is deprecated and not supported")]
    OnionV2NotSupported,
    #[error("Peer provided too many supported protocols: expected max {max} but got {length}")]
    PeerIdentityTooManyProtocols { length: usize, max: usize },
    #[error("Peer provided too many addresses: expected max {max} but got {length}")]
    PeerIdentityTooManyAddresses { length: usize, max: usize },
    #[error("Peer provided a protocol id that exceeds the maximum length: expected max {max} but got {length}")]
    PeerIdentityProtocolIdTooLong { length: usize, max: usize },
    #[error("Peer provided a user agent that exceeds the maximum length: expected max {max} but got {length}")]
    PeerIdentityUserAgentTooLong { length: usize, max: usize },
}

impl PeerValidatorError {
    /// Returns whether this validation failure indicates hostile peer input.
    ///
    /// A peer with no advertised address, or only local addresses, may simply
    /// be behind NAT or misconfigured. Rejecting the update is sufficient and
    /// avoids punishing a reachable peer that relayed it.
    pub fn is_ban_offence(&self) -> bool {
        match self {
            Self::PeerHasNoAddresses { .. } | Self::PeerHasNoUsableAddresses { .. } => false,
            Self::InvalidPeerSignature { .. } |
            Self::InvalidPeerAddresses { .. } |
            Self::InvalidMultiaddr(_) |
            Self::OnionV2NotSupported |
            Self::PeerIdentityTooManyProtocols { .. } |
            Self::PeerIdentityTooManyAddresses { .. } |
            Self::PeerIdentityProtocolIdTooLong { .. } |
            Self::PeerIdentityUserAgentTooLong { .. } => true,
        }
    }

    pub fn as_ban_duration(&self) -> Option<Duration> {
        self.is_ban_offence().then_some(BAN_DURATION_LONG)
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn only_non_hostile_address_absence_errors_avoid_a_ban() {
        let peer = NodeId::default();
        assert!(
            PeerValidatorError::PeerHasNoAddresses { peer: peer.clone() }
                .as_ban_duration()
                .is_none()
        );
        assert!(
            PeerValidatorError::PeerHasNoUsableAddresses { peer }
                .as_ban_duration()
                .is_none()
        );
        assert!(
            PeerValidatorError::InvalidMultiaddr("bad address".to_string())
                .as_ban_duration()
                .is_some()
        );
    }
}