本体提供的函数实现，只能对于TCP生效，UDP没法生效，看文档没搞明白，有了解UDP怎么设置DSCP的童鞋，可以在评论区给予答复。

用法是这样的，每个TCP在建立链接后，立即创建这个QOSS的实例，当然也可以在链接前，但在连接前有一定限制就是说，你必须在连接前把IP+PORT地址传进去，链接建立后在创建QOS就不需要传入IP+PORT地址。

同时，在关联的TCP链接关闭时需要销毁这个，否则就会产生QOS2内核句柄资源泄漏。

DSCP值26，就等于 IP_TOS: 0x68，即FLASH，[IPTOS_LOWDELAY] 宏的效果【MACOS/LINUX】上，Windows 平台被微软禁用支援了。

头文件声明：

        class QoSS final{public:QoSS(int fd) noexcept;~QoSS() noexcept;public:static std::shared_ptr<QoSS>            New(int fd, const boost::asio::ip::address& host, int port) noexcept { return New(fd, host, port, false); }static std::shared_ptr<QoSS>            New(int fd) noexcept { return New(fd, boost::asio::ip::address_v4::any(), 0, true); }private:static std::shared_ptr<QoSS>            New(int fd, const boost::asio::ip::address& host, int port, bool noaddress) noexcept;private:int                                     fd_ = -1;void*                                   h_  = NULL;DWORD                                   f_  = 0;};

源文件：

        QoSS::QoSS(int fd) noexcept: fd_(fd), h_(NULL), f_(NULL){}QoSS::~QoSS() noexcept{if (NULL != h_){if (f_ != 0){QOSRemoveSocketFromFlow(h_, fd_, f_, 0);}QOSCloseHandle(h_);}}std::shared_ptr<QoSS> QoSS::New(int fd, const boost::asio::ip::address& host, int port, bool noaddress) noexcept{if (fd == INVALID_SOCKET){return NULL;}std::shared_ptr<QoSS> qos = make_shared_object<QoSS>(fd);if (NULL == qos){return NULL;}QOS_VERSION ver = { 1, 0 };if (!QOSCreateHandle(&ver, &qos->h_)){return NULL;}if (noaddress){if (!QOSAddSocketToFlow(qos->h_, fd, NULL, QOSTrafficTypeControl, QOS_NON_ADAPTIVE_FLOW, &qos->f_)){return NULL;}}else{if (port <= IPEndPoint::MinPort || port > IPEndPoint::MaxPort){return NULL;}if (!host.is_v4() && !host.is_v6()){return NULL;}if (IPEndPoint::IsInvalid(host)){return NULL;}if (host.is_v4()){sockaddr_in in{};in.sin_family = AF_INET;in.sin_port = htons(port);in.sin_addr.s_addr = htonl(host.to_v4().to_uint());if (!QOSAddSocketToFlow(qos->h_, fd, reinterpret_cast<sockaddr*>(&in), QOSTrafficTypeControl, QOS_NON_ADAPTIVE_FLOW, &qos->f_)){return NULL;}}else{sockaddr_in6 in6{};in6.sin6_family = AF_INET6;in6.sin6_port = htons(port);memcpy(&in6.sin6_addr, host.to_v6().to_bytes().data(), sizeof(in6.sin6_addr));if (!QOSAddSocketToFlow(qos->h_, fd, reinterpret_cast<sockaddr*>(&in6), QOSTrafficTypeControl, QOS_NON_ADAPTIVE_FLOW, &qos->f_)){return NULL;}}}// We shift the complete ToS value by 3 to get rid of the 3 bit ECN fieldDWORD dscp = 26;// Sets DSCP to the same as Linux// This will fail if we're not admin, but we ignore itif (!QOSSetFlow(qos->h_, qos->f_, QOSSetOutgoingDSCPValue, sizeof(DWORD), &dscp, 0, NULL)){return NULL;}return qos;}

参考文档：

https://learn.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options#windows-support-for-ip_proto-options

https://learn.microsoft.com/en-us/windows-server/networking/technologies/qos/qos-policy-manage#advanced-qos-settings-dscp-marking-override

https://learn.microsoft.com/en-us/windows-server/networking/technologies/qos/qos-policy-manage#advanced-qos-settings-dscp-marking-override

https://learn.microsoft.com/en-us/previous-versions/windows/desktop/dd874008(v=vs.85)