Method AttemptToEvictConnection

src/net.cpp:1102–1144

Try to find a connection to evict when the node is full. * Extreme care must be taken to avoid opening the node to attacker * triggered network partitioning. * The strategy used here is to protect a small number of peers * for each of several distinct characteristics which are difficult * to forge. In order to partition a node the attacker must be * simultaneously better at all of

 *   simultaneously better at all of them than honest peers.
 */
bool CConnman::AttemptToEvictConnection()
{
    std::vector<NodeEvictionCandidate> vEvictionCandidates;
    {

        LOCK(m_nodes_mutex);
        for (const CNode* node : m_nodes) {
            if (node->HasPermission(NetPermissionFlags::NoBan))
                continue;
            if (!node->IsInboundConn())
                continue;
            if (node->fDisconnect)
                continue;
            bool peer_relay_txes = false;
            bool peer_filter_not_null = false;
            if (node->m_tx_relay != nullptr) {
                LOCK(node->m_tx_relay->cs_filter);
                peer_relay_txes = node->m_tx_relay->fRelayTxes;
                peer_filter_not_null = node->m_tx_relay->pfilter != nullptr;
            }
            NodeEvictionCandidate candidate = {node->GetId(), node->m_connected, node->m_min_ping_time,
                                               node->m_last_block_time, node->m_last_tx_time,
                                               HasAllDesirableServiceFlags(node->nServices),
                                               peer_relay_txes, peer_filter_not_null, node->nKeyedNetGroup,
                                               node->m_prefer_evict, node->addr.IsLocal(),
                                               node->ConnectedThroughNetwork()};
            vEvictionCandidates.push_back(candidate);
        }
    }
    const std::optional<NodeId> node_id_to_evict = SelectNodeToEvict(std::move(vEvictionCandidates));
    if (!node_id_to_evict) {
        return false;
    }
    LOCK(m_nodes_mutex);
    for (CNode* pnode : m_nodes) {
        if (pnode->GetId() == *node_id_to_evict) {
            LogPrint(BCLog::NET, "selected %s connection for eviction peer=%d; disconnecting\n", pnode->ConnectionTypeAsString(), pnode->GetId());
            pnode->fDisconnect = true;
            return true;
        }
    }
    return false;
}

void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
    struct sockaddr_storage sockaddr;