TCP 插座和 UDP 插座之间的 Select (c)

Question

我正在 c 中创建一个服务器，它处理 tcp 连接以供管理员更改服务器配置和 udp 连接以处理多个客户端

这是我的代码：

    struct sockaddr_in si_minhaTCP,si_minhaUDP, si_outra;
    int nready, maxfdp1;
    int fdTcp;
    int fdUdp;
    fd_set rset;
    if (argc != 4) {
    printf("server {client port(udp)} {admin port(tcp)} {registry file path}\n");
    exit(-1);
  }

    fdTcp = socket(AF_INET, SOCK_STREAM, 0);
    bzero(&si_minhaTCP, sizeof(si_minhaTCP));
    si_minhaTCP.sin_family = AF_INET;
    si_minhaTCP.sin_addr.s_addr = htonl(INADDR_ANY);
    si_minhaTCP.sin_port = htons((short) atoi(argv[2]));
    bind(fdTcp, (struct sockaddr*)&si_minhaTCP, sizeof(si_minhaTCP));
    listen(fdTcp, 10);


        
    fdUdp = socket(AF_INET, SOCK_DGRAM, 0);
    si_minhaUDP.sin_family = AF_INET;
    si_minhaUDP.sin_addr.s_addr = htonl(INADDR_ANY);
    si_minhaUDP.sin_port = htons((short) atoi(argv[1]));
    bind(fdUdp, (struct sockaddr*)&si_minhaUDP, sizeof(si_minhaUDP));


    FD_ZERO(&rset);

    maxfdp1 = max(fdTcp, fdUdp) + 1;
    for (;;)
    {
      FD_SET(fdTcp, &rset);
      FD_SET(fdUdp, &rset);
      // select the ready descriptor

      nready = select(maxfdp1, &rset, NULL, NULL, NULL);
      if (FD_ISSET(fdTcp, &rset))
      {

          //handle tcp connection
      }
      if (FD_ISSET(fdUdp, &rset))
      {
          //handle udp connection
      }

    }
           

当我运行此代码并尝试使用 udp 客户端对其进行测试时，它什么也没做

Answer 1

但是，如果您以 root 身份运行程序并且没有其他程序正在运行，那么您可以使用低于 1024 的端口，这些程序已经使用了该端口...