特定接口上的TCP/IP连接

Question

我想使用两个网络路由之一连接到服务器.怎么会这样做？我用谷歌搜索了很多,常见的答案是摆弄路由表,但是由于目的地只有一个IP地址,这无济于事.大多数示例都是具有单个网卡的客户端和具有多个NIC的服务器,但在这种情况下则相反.

ForceBindIP应用程序似乎能够提供这种类型的功能,所以我想它一定是可能的.

             +----->-------+
192.168.1.3  |      B      |          192.168.1.4
      +--------+      +--------+      +--------+
      | Client |      | Switch |-->---| Server |
      +--------+      +--------+      +--------+
192.168.1.2  |      A      |
             +----->-------+

我很可能会使用C++和winsock来做到这一点.我需要能够随意打开给定路由上的连接(即不得静态绑定到特定路由).我将使用普通的'TCP/IP.

编辑:Windows 7客户端

Answer 1

使用bind()功能绑定套接字要么192.168.1.3或192.168.1.2打电话之前connect(),ConnectEx()或WSAConnect().这告诉套接字使用哪个特定接口进行传出连接.例如:

SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

sockaddr_in localaddr = {0};
localaddr.sin_family = AF_INET;
localaddr.sin_addr.s_addr = inet_addr("192.168.1.3");
bind(s, (sockaddr*)&localaddr, sizeof(localaddr));

sockaddr_in remoteaddr = {0};
remoteaddr.sin_family = AF_INET;
remoteaddr.sin_addr.s_addr = inet_addr("192.168.1.4");
remoteaddr.sin_port = 12345; // whatever the server is listening on
connect(s, (sockaddr*)&remoteaddr, sizeof(remoteaddr));

或者:

addrinfo localhints = {0};
localhints.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV;
localhints.ai_family = AF_INET;
localhints.ai_socktype = SOCK_STREAM;
localhints.ai_protocol = IPPROTO_TCP;

addrinfo *localaddr = NULL;
getaddrinfo("192.168.1.3", "0", &localhints, &localaddr);
bind(s, localaddr->ai_addr, localaddr->ai_addrlen);
freeaddrinfo(localaddr);

addrinfo remotehints = {0};
remotehints.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV;
remotehints.ai_family = AF_INET;
remotehints.ai_socktype = SOCK_STREAM;
remotehints.ai_protocol = IPPROTO_TCP;

addrinfo *remoteaddr = NULL;
getaddrinfo("192.168.1.4", "12345", &remotehints, &remoteaddr);
connect(s, remoteaddr->ai_addr, remoteaddr->ai_addrlen);
freeaddrinfo(remoteaddr);