飞鸽源码分析之一——MsgMng::WSockInit

 BOOL MsgMng::WSockInit(BOOL recv_flg) { WSADATA wsaData; if (::WSAStartup(0x0101, &wsaData) != 0) return GetSockErrorMsg("WSAStart()"), FALSE; if ((udp_sd = ::socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET) return GetSockErrorMsg("Please setup TCP/IP(controlpanel->network)/r/n"), FALSE; if (recv_flg != TRUE) return TRUE; if ((tcp_sd = ::socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) return GetSockErrorMsg("Please setup2 TCP/IP(controlpanel->network)/r/n"), FALSE; struct sockaddr_in addr; memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = local.addr; addr.sin_port = local.portNo; if (::bind(udp_sd, (LPSOCKADDR)&addr, sizeof(addr)) != 0) return GetSockErrorMsg("bind()"), FALSE; if (::bind(tcp_sd, (LPSOCKADDR)&addr, sizeof(addr)) != 0) { ::closesocket(tcp_sd); tcp_sd = INVALID_SOCKET; GetSockErrorMsg("bind(tcp) error. Can't support file attach"); } // This function controls the I/O mode of a socket. // Set the socket I/O mode: In this case FIONBIO // enables or disables the blocking mode for the // socket based on the numerical value of iMode. // If flg = FALSE, blocking is enabled; // If flg = TRUE, non-blocking mode is enabled. // 上面是MSDN上面的解释，也就是说设置为非阻塞模式 BOOL flg = TRUE; if (::ioctlsocket(udp_sd, FIONBIO, (unsigned long *)&flg) != 0) return GetSockErrorMsg("ioctlsocket(nonblock)"), FALSE; if (IsAvailableTCP() && ::ioctlsocket(tcp_sd, FIONBIO, (unsigned long *)&flg) != 0) return GetSockErrorMsg("ioctlsocket tcp(nonblock)"), FALSE; // 设置UDP允许广播 flg = TRUE; if (::setsockopt(udp_sd, SOL_SOCKET, SO_BROADCAST, (char *)&flg, sizeof(flg)) != 0) return GetSockErrorMsg("setsockopt(broadcast)"), FALSE; // Specifies the total per-socket buffer space reserved for sends. // This is unrelated to SO_MAX_MSG_SIZE and does not necessarily // correspond to the size of a TCP send window. int buf_size = MAX_SOCKBUF, buf_minsize = MAX_SOCKBUF / 2; if (::setsockopt(udp_sd, SOL_SOCKET, SO_SNDBUF, (char *)&buf_size, sizeof(int)) != 0 && ::setsockopt(udp_sd, SOL_SOCKET, SO_SNDBUF, (char *)&buf_minsize, sizeof(int)) != 0) GetSockErrorMsg("setsockopt(sendbuf)"); // Specifies the total per-socket buffer space reserved for receives. // This is unrelated to SO_MAX_MSG_SIZE and does not necessarily // correspond to the size of the TCP receive window. buf_size = MAX_SOCKBUF, buf_minsize = MAX_SOCKBUF / 2; if (::setsockopt(udp_sd, SOL_SOCKET, SO_RCVBUF, (char *)&buf_size, sizeof(int)) != 0 && ::setsockopt(udp_sd, SOL_SOCKET, SO_RCVBUF, (char *)&buf_minsize, sizeof(int)) != 0) GetSockErrorMsg("setsockopt(recvbuf)"); // Allows the socket to be bound to an address that is already in use. // (See bind.) Not applicable on ATM sockets. // 这个套接字选项通知内核，如果端口忙，但TCP状态位于 TIME_WAIT ，可以重用端口。 // 如果端口忙，而TCP状态位于其他状态，重用端口时依旧得到一个错误信息，指明"地址已经使用中"。 // 如果你的服务程序停止后想立即重启，而新套接字依旧使用同一端口，此时 SO_REUSEADDR 选项非常有用。 // 必须意识到，此时任何非期望数据到达，都可能导致服务程序反应混乱，不过这只是一种可能，事实上很不可能。 //一个套接字由相关五元组构成，协议、本地地址、本地端口、远程地址、远程端口。 // SO_REUSEADDR 仅仅表示可以重用本地本地地址、本地端口，整个相关五元组还是唯一确定的。 // 所以，重启后的服务程序有可能收到非期望数据。必须慎重使用 SO_REUSEADDR 选项。 flg = TRUE; // REUSE ADDR if (IsAvailableTCP() && ::setsockopt(tcp_sd, SOL_SOCKET, SO_REUSEADDR, (char *)&flg, sizeof(flg)) != 0) GetSockErrorMsg("setsockopt tcp(reuseaddr)"); if (IsAvailableTCP() && ::listen(tcp_sd, 5) != 0) return FALSE; return TRUE; }