ZeroTierOne/osdep/WindowsEthernetTap.hpp

/*
 * Copyright (c)2019 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2026-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#ifndef ZT_WINDOWSETHERNETTAP_HPP
#define ZT_WINDOWSETHERNETTAP_HPP

#include "../node/Constants.hpp"
#include "../node/InetAddress.hpp"
#include "../node/MulticastGroup.hpp"
#include "../node/Mutex.hpp"
#include "../osdep/Thread.hpp"
#include "EthernetTap.hpp"

#include <ifdef.h>
#include <queue>
#include <stdexcept>
#include <stdio.h>
#include <stdlib.h>
#include <string>

namespace ZeroTier {

class WindowsEthernetTap : public EthernetTap {
  public:
    /**
     * Installs a new instance of the ZT tap driver
     *
     * @param pathToInf Path to zttap driver .inf file
     * @param deviceInstanceId Buffer to fill with device instance ID on success (and if SetupDiGetDeviceInstanceIdA succeeds, which it should)
     * @return Empty string on success, otherwise an error message
     */
    static std::string addNewPersistentTapDevice(const char* pathToInf, std::string& deviceInstanceId);

    /**
     * Uninstalls all persistent tap devices that have legacy drivers
     *
     * @return Empty string on success, otherwise an error message
     */
    static std::string destroyAllLegacyPersistentTapDevices();

    /**
     * Uninstalls all persistent tap devices on the system
     *
     * @return Empty string on success, otherwise an error message
     */
    static std::string destroyAllPersistentTapDevices();

    /**
     * Uninstalls a specific persistent tap device by instance ID
     *
     * @param instanceId Device instance ID
     * @return Empty string on success, otherwise an error message
     */
    static std::string deletePersistentTapDevice(const char* instanceId);

    /**
     * Disable a persistent tap device by instance ID
     *
     * @param instanceId Device instance ID
     * @param enabled Enable device?
     * @return True if device was found and disabled
     */
    static bool setPersistentTapDeviceState(const char* instanceId, bool enabled);

    WindowsEthernetTap(
        const char* hp,
        const MAC& mac,
        unsigned int mtu,
        unsigned int metric,
        uint64_t nwid,
        const char* friendlyName,
        void (*handler)(void*, void*, uint64_t, const MAC&, const MAC&, unsigned int, unsigned int, const void*, unsigned int),
        void* arg);

    virtual ~WindowsEthernetTap();

    virtual void setEnabled(bool en);
    virtual bool enabled() const;
    virtual bool addIp(const InetAddress& ip);
    virtual bool removeIp(const InetAddress& ip);
    virtual std::vector<InetAddress> ips() const;
    virtual void put(const MAC& from, const MAC& to, unsigned int etherType, const void* data, unsigned int len);
    virtual std::string deviceName() const;
    virtual void setFriendlyName(const char* friendlyName);
    virtual std::string friendlyName() const;
    virtual void scanMulticastGroups(std::vector<MulticastGroup>& added, std::vector<MulticastGroup>& removed);
    virtual void setMtu(unsigned int mtu);
    virtual void setDns(const char* domain, const std::vector<InetAddress>& servers);

    inline const NET_LUID& luid() const
    {
        return _deviceLuid;
    }
    inline const GUID& guid() const
    {
        return _deviceGuid;
    }
    inline const std::string& instanceId() const
    {
        return _deviceInstanceId;
    }
    NET_IFINDEX interfaceIndex() const;

    void threadMain() throw();

    bool isInitialized() const
    {
        return _initialized;
    };

  private:
    NET_IFINDEX _getDeviceIndex();   // throws on failure
    std::vector<std::string> _getRegistryIPv4Value(const char* regKey);
    void _setRegistryIPv4Value(const char* regKey, const std::vector<std::string>& value);
    void _syncIps();

    void (*_handler)(void*, void*, uint64_t, const MAC&, const MAC&, unsigned int, unsigned int, const void*, unsigned int);
    void* _arg;
    MAC _mac;
    uint64_t _nwid;
    volatile unsigned int _mtu;
    Thread _thread;

    volatile HANDLE _tap;
    HANDLE _injectSemaphore;

    GUID _deviceGuid;
    NET_LUID _deviceLuid;
    std::string _netCfgInstanceId;
    std::string _deviceInstanceId;
    std::string _mySubkeyName;
    std::string _friendlyName;
    Mutex _friendlyName_m;

    std::vector<InetAddress> _assignedIps;   // IPs assigned with addIp
    Mutex _assignedIps_m;

    std::vector<MulticastGroup> _multicastGroups;

    struct _InjectPending {
        unsigned int len;
        char data[ZT_MAX_MTU + 32];
    };
    std::queue<_InjectPending> _injectPending;
    Mutex _injectPending_m;

    std::string _pathToHelpers;

    volatile bool _run;
    volatile bool _initialized;
    volatile bool _enabled;

    mutable std::vector<InetAddress> _ifaddrs;
    mutable uint64_t _lastIfAddrsUpdate;
};

}   // namespace ZeroTier

#endif