C/C++ IPV6服务器socket绑定在::，接受ipv4链接（双栈）

先决条件：

1、 创建IPV6套接字

2、打开套接字可重用

3、禁用仅限 IPV6

                BOOL bEnable = FALSE;
                if (setsockopt(listenfd_, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<char*>(&bEnable), sizeof(bEnable)) < 0)
                {
                    return false;
                }
 

4、绑定套接字

5、使用 struct sockaddr_in6 结构接受套接字，而不是用缺省使用 “sockaddr”，否则 10014（WSAEFAULT）错误，并导致套接字句柄泄漏。

                                struct sockaddr_in6 address = { 0 };
                                int address_size = sizeof(address);

                                int sockfd = WSAAccept(listenfd_, (sockaddr*)&address, &address_size, NULL, NULL);
                                if (sockfd != INVALID_SOCKET)
                                {
                                    AcceptSocketEventArgs e = { Adjust(sockfd) };
                                    OnAcceptSocket(e);
                                }

完整大体代码为；

        bool Open(const char* localIP, int localPort, int backlog) noexcept{if (localPort < IPEndPoint::MinPort || localPort > IPEndPoint::MaxPort){return false;}if (NULL == localIP || *localIP == '\x0'){return false;}if (listenfd_ != INVALID_SOCKET){return false;}if (NULL != hEvent_){return false;}if (NULL != afo_){return false;}if (NULL == context_){return false;}boost::system::error_code ec;boost::asio::ip::address bindIP = StringToAddress(localIP, ec);if (ec){return false;}if (backlog < 1){backlog = PPP_LISTEN_BACKLOG;}in_ = bindIP.is_v4();if (bindIP.is_v6()){struct sockaddr_in6 in6;memset(&in6, 0, sizeof(in6));in6.sin6_family = AF_INET6;in6.sin6_port = htons(localPort);if (inet_pton(AF_INET6, localIP, &in6.sin6_addr) < 1){return false;}listenfd_ = WSASocket(AF_INET6, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);if (listenfd_ == INVALID_SOCKET){return false;}Adjust(listenfd_);if (!Socket::ReuseSocketAddress(listenfd_, true)){return false;}BOOL bEnable = FALSE;if (setsockopt(listenfd_, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<char*>(&bEnable), sizeof(bEnable)) < 0){return false;}if (bind(listenfd_, reinterpret_cast<sockaddr*>(&in6), sizeof(in6)) < 0){return false;}}elif(bindIP.is_v4()){struct sockaddr_in in4;memset(&in4, 0, sizeof(in4));in4.sin_family = AF_INET;in4.sin_port = htons(localPort);if (inet_pton(AF_INET, localIP, &in4.sin_addr) < 1){return false;}listenfd_ = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);if (listenfd_ == INVALID_SOCKET){return false;}Adjust(listenfd_);if (!Socket::ReuseSocketAddress(listenfd_, true)){return false;}if (bind(listenfd_, reinterpret_cast<sockaddr*>(&in4), sizeof(in4)) < 0){return false;}}else{return false;}if (listen(listenfd_, backlog) < 0){return false;}hEvent_ = WSACreateEvent();if (hEvent_ == WSA_INVALID_EVENT){return false;}if (WSAEventSelect(listenfd_, hEvent_, FD_ACCEPT | FD_CLOSE) != NOERROR){return false;}afo_ = make_shared_void_pointer<boost::asio::windows::object_handle>(*context_, hEvent_);return Next();}

接受套接字连入部分：

WSANETWORKEVENTS events;
if (WSAEnumNetworkEvents(listenfd, hEvent, &events) == NOERROR)
{if (events.lNetworkEvents & FD_ACCEPT){if (events.iErrorCode[FD_ACCEPT_BIT] == 0){struct sockaddr_in6 address = { 0 };int address_size = sizeof(address);int sockfd = WSAAccept(listenfd_, (sockaddr*)&address, &address_size, NULL, NULL);if (sockfd != INVALID_SOCKET){AcceptSocketEventArgs e = { Adjust(sockfd) };OnAcceptSocket(e);}}}elif(events.lNetworkEvents & FD_CLOSE){if (events.iErrorCode[FD_ACCEPT_BIT] == 0) /* event is operation_canceled. */{return;}}
}