Method CreateNodeFromAcceptedSocket

src/net.cpp:1174–1273

}

void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                                            NetPermissionFlags permissionFlags,
                                            const CAddress& addr_bind,
                                            const CAddress& addr)
{
    int nInbound = 0;
    int nMaxInbound = nMaxConnections - m_max_outbound;

    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(permissionFlags, inbound_onion ? std::optional<CNetAddr>{} : addr);
    if (NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::Implicit)) {
        NetPermissions::ClearFlag(permissionFlags, NetPermissionFlags::Implicit);
        if (gArgs.GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY)) NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::ForceRelay);
        if (gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::Relay);
        NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::Mempool);
        NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::NoBan);
    }

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

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

    if (!IsSelectableSocket(sock->Get()))
    {
        LogPrintf("connection from %s dropped: non-selectable socket\n", addr.ToString());
        return;
    }

    // According to the internet TCP_NODELAY is not carried into accepted sockets
    // on all platforms.  Set it again here just to be sure.
    SetSocketNoDelay(sock->Get());

    // Don't accept connections from banned peers.
    bool banned = m_banman && m_banman->IsBanned(addr);
    if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::NoBan) && banned)
    {
        LogPrint(BCLog::NET, "connection from %s dropped (banned)\n", addr.ToString());
        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(permissionFlags, NetPermissionFlags::NoBan) && nInbound + 1 >= nMaxInbound && discouraged)
    {
        LogPrint(BCLog::NET, "connection from %s dropped (discouraged)\n", addr.ToString());
        return;
    }