Method CreateNodeFromAcceptedSocket

src/net.cpp:1775–1885

}

void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                                            NetPermissionFlags permission_flags,
                                            const CService& addr_bind,
                                            const CService& addr)
{
    AssertLockNotHeld(m_nodes_mutex);

    int nInbound = 0;

    const bool inbound_onion = std::find(m_onion_binds.begin(), m_onion_binds.end(), addr_bind) != m_onion_binds.end();

    // Tor inbound connections do not reveal the peer's actual network address.
    // Therefore do not apply address-based whitelist permissions to them.
    AddWhitelistPermissionFlags(permission_flags, inbound_onion ? std::optional<CNetAddr>{} : addr, vWhitelistedRangeIncoming);

    {
        LOCK(m_nodes_mutex);
        for (const CNode* pnode : m_nodes) {
            if (pnode->IsInboundConn()) nInbound++;
        }
    }

    if (!fNetworkActive) {
        LogDebug(BCLog::NET, "connection from %s dropped: not accepting new connections\n", addr.ToStringAddrPort());
        return;
    }

    if (!sock->IsSelectable()) {
        LogInfo("connection from %s dropped: non-selectable socket\n", addr.ToStringAddrPort());
        return;
    }

    // According to the internet TCP_NODELAY is not carried into accepted sockets
    // on all platforms.  Set it again here just to be sure.
    const int on{1};
    if (sock->SetSockOpt(IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) == SOCKET_ERROR) {
        LogDebug(BCLog::NET, "connection from %s: unable to set TCP_NODELAY, continuing anyway\n",
                 addr.ToStringAddrPort());
    }

    // Don't accept connections from banned peers.
    bool banned = m_banman && m_banman->IsBanned(addr);
    if (!NetPermissions::HasFlag(permission_flags, NetPermissionFlags::NoBan) && banned)
    {
        LogDebug(BCLog::NET, "connection from %s dropped (banned)\n", addr.ToStringAddrPort());
        return;
    }

    // Only accept connections from discouraged peers if our inbound slots aren't (almost) full.
    bool discouraged = m_banman && m_banman->IsDiscouraged(addr);
    if (!NetPermissions::HasFlag(permission_flags, NetPermissionFlags::NoBan) && nInbound + 1 >= m_max_inbound && discouraged)
    {
        LogDebug(BCLog::NET, "connection from %s dropped (discouraged)\n", addr.ToStringAddrPort());
        return;
    }

    if (nInbound >= m_max_inbound)
    {