c++ - 如何将套接字绑定(bind)到 ipv6 地址？

Question

我正在尝试将 ipv4 应用程序移植到 ipv6，但无法将套接字绑定(bind)到 ipv6 地址。

问题出在这里:

err=bind(listening, (sockaddr*)&hint, sizeof(hint));

err 应该为 0，但在此代码中它返回 -1。出了什么问题？

SOCKET listening = socket(AF_INET6, SOCK_STREAM, 0);
    if (listening == INVALID_SOCKET)
    {
        cerr << "Can't create a socket! Quitting" << endl;
        return;
    }
    int err;
    // Bind the ip address and port to a socket
    sockaddr_in6 hint;
    hint.sin6_family = AF_INET6;
    hint.sin6_flowinfo = 0;
    hint.sin6_port = htons(54000);
    hint.sin6_addr = in6addr_any;
    err=bind(listening, (sockaddr*)&hint, sizeof(hint)); //<======= here

Answer 1

您可以(并且应该)使用getaddrinfo()，而不是手动填充sockaddr_in6相反，让它为您分配一个正确填充的 sockaddr_in6，例如:

int err;

SOCKET listening = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
if (listening == INVALID_SOCKET)
{
    err = WSAGetLastError(); // or errno on non-Windows platforms...
    cerr << "Can't create a socket! Error " << err << ". Quitting" << endl;
    return;
}

// Bind the ip address and port to a socket

addrinfo hint = {};
hint.ai_flags = AI_NUMERICHOST | AI_PASSIVE;
hint.ai_family = AF_INET6;
hint.ai_socktype = SOCK_STREAM;
hint.ai_protocol = IPPROTO_TCP;

addrinfo *res;

err = getaddrinfo("::0", "54000", &hint, &res);
if (err != 0)
{
    cerr << "Can't get address to bind the socket! Error " << err << ". Quitting" << endl;
    closesocket(listening); // or close() on non-Windows platforms...
    return;
}

err = bind(listening, res->ai_addr, res->ai_addrlen);
if (err == SOCKET_ERROR)
{
    err = WSAGetLastError(); // or errno on non-Windows platforms...
    cerr << "Can't bind the socket! Error " << err << ". Quitting" << endl;
    freeaddrinfo(res);
    closesocket(listening); // or close() on non-Windows platforms...
    return;
}

freeaddrinfo(res);

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