如何设置 Winsock UDP 套接字?

本文介绍了如何设置 Winsock UDP 套接字?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我想创建一个只向客户端发送数据的 Winsock UDP 套接字.我希望内核为我选择一个可用的端口.另一方面，我想指出要使用哪个本地 IP，因为我正在运行一些网卡.

I want to create a Winsock UDP socket that only sends data to a client. I want the kernel to choose an available port for me. On the other hand, I want to indicate which local IP to use, since I'm running a few nics.

我尝试过梳理套接字选项的迷宫，以及将套接字地址中的端口绑定设置为 0，但均无济于事.

I've tried combing through the maze of socket options, as well as binding with the port in the socket address set to 0 to no avail.

我的代码是 Win32 C++.

My code is in Win32 C++.

推荐答案

请原谅缺少错误检查:

char pkt[...]; size_t pkt_length = ...; sockaddr_in dest; sockaddr_in local; WSAData data; WSAStartup( MAKEWORD( 2, 2 ), &data ); local.sin_family = AF_INET; local.sin_addr.s_addr = inet_addr( <source IP address> ); local.sin_port = 0; // choose any dest.sin_family = AF_INET; dest.sin_addr.s_addr = inet_addr( <destination IP address> ); dest.sin_port = htons( <destination port number> ); // create the socket SOCKET s = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP ); // bind to the local address bind( s, (sockaddr *)&local, sizeof(local) ); // send the pkt int ret = sendto( s, pkt, pkt_length, 0, (sockaddr *)&dest, sizeof(dest) );