Question

我正在尝试使用BSD套接字为UE3实现IPv6套接字连接。我已经成功地从UE4移植了使用所有sockaddr_in6和其他相对于IPv6结构和变量的代码。

连接到常规网络或4G时连接正常，但通过Mac共享功能连接到NAT64网络（Apple Approvals必需）时，Connect（）始终返回ENETUNREACH。我已经用iPad4和iPhone6S进行了测试，其中包含许多代码修改（删除setIPv6Only函数，查看AF_UNSPEC等），但没有任何运气。

调试一些数据发现getaddrinfo()正在从DNS返回IPv4，甚至认为我在我的DNS表中设置了AAAA配置，指向允许IPv6的Amazon AWS服务器（我添加了）最近这个最后一部分，因为我以前认为从服务器端也需要IPv6）

这是DNS查找：

FScopeLock ScopeLock(&HostByNameSynch);
addrinfo* AddrInfo = NULL;

// We are only interested in IPv6 addresses.
addrinfo HintAddrInfo;
appMemzero(&HintAddrInfo, sizeof(HintAddrInfo));

/* We only care about IPV6 results */
HintAddrInfo.ai_family = AF_INET6;//AF_UNSPEC;
HintAddrInfo.ai_socktype = SOCK_STREAM;
HintAddrInfo.ai_flags = AI_DEFAULT;

INT ErrorCode = SE_HOST_NOT_FOUND;
ErrorCode = getaddrinfo(HostName, NULL, &HintAddrInfo, &AddrInfo);
//ESocketErrors SocketError = TranslateGAIErrorCode(ErrorCode);
if (ErrorCode == SE_NO_ERROR)
{
    for (; AddrInfo != nullptr; AddrInfo = AddrInfo->ai_next)
    {
        if (AddrInfo->ai_family == AF_INET6)
        {
            /*sockaddr_in6* IPv6SockAddr = reinterpret_cast<sockaddr_in6*>(AddrInfo->ai_addr);
            if (IPv6SockAddr != nullptr)
            {
                static_cast<FInternetAddrBSDIPv6&>(OutAddr).SetIp(IPv6SockAddr->sin6_addr);
                return SE_NO_ERROR;
            }*/

            struct sockaddr_in6 input_socket6;
            memset (&input_socket6, 0, sizeof(struct sockaddr_in6));
            memcpy (&input_socket6, AddrInfo->ai_addr, AddrInfo->ai_addrlen);

            Addr.SetIp(input_socket6.sin6_addr);
            ErrorCode = 0;  // good to go.
            break;
        }
    }
}

freeaddrinfo(AddrInfo);

return ErrorCode;

以下是Connect部分：

UBOOL FSocketBSD::Connect(const FInternetAddrBSDIPv6& Addr)
{
INT Err = 0;

Err = connect(Socket, (sockaddr*)(FInternetAddrBSDIPv6&)Addr, sizeof(sockaddr_in6));//connect(Socket,Addr,sizeof(struct sockaddr_in));

debugf(TEXT("TCP Connect to with V6 %s"), *Addr.ToString(TRUE) );

if (Err == 0)
{
    return TRUE;
}
else 
{
    debugf(TEXT("TCP ERROR Connect with result: %s"), GSocketSubsystem->GetSocketError(Err) );
}

Err = GSocketSubsystem->GetLastErrorCode();
INT Return = FALSE;
switch (Err)
{
    case 0:
    case EAGAIN:
    case EINPROGRESS:
    case EINTR:
        Return = TRUE;
        break;
}
return Return;
}

这是套接字创建：

SOCKET Socket = INVALID_SOCKET;
FSocketBSD* NewSocket = NULL;

// Creates a stream (TCP) socket
Socket = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
NewSocket = (Socket != INVALID_SOCKET) ? new FSocketBSD(Socket,SOCKTYPE_Streaming,SocketDescription) : NULL;

if (!NewSocket)
{
    debugf(NAME_Init, TEXT("Failed to create IPv6 socket %s [%s]"), *SocketDescription);
}
else 
{
    NewSocket->SetIPv6Only(false);

    // disable the SIGPIPE exception 
    int bAllow = 1;
    setsockopt(Socket, SOL_SOCKET, SO_NOSIGPIPE, &bAllow, sizeof(bAllow)); 
}

return NewSocket;


UBOOL FSocketBSD::SetIPv6Only(UBOOL bIPv6Only)
{
    INT v6only = bIPv6Only ? 1 : 0;
    UBOOL bOk = setsockopt(Socket,IPPROTO_IPV6,IPV6_V6ONLY,(char*) &v6only,sizeof( v6only )) == 0;

    if(bOk == false)
    {
        //check(SocketSubsystem);
        debugf(NAME_Init, TEXT("Failed to set sock opt for socket (%s)"), GSocketSubsystem->GetSocketError());
    }

    return bOk;
}

以下是一些调试信息：

[0009.49] Log: TCP SetIp TCHAR u101si.info
[0009.49] Log: TCP GetHostByNameFromCache with FInternetAddrBSDIPv6
[0009.49] Log: TCP GetHostByName starting async task
[0009.49] Log: TCP Performing DNS lookup for u101si.info
[0009.66] Log: TCP SetIp in6_addr
[0009.66] Log: TCP AddHostNameToCache with FInternetAddrBSDIPv6
[0009.66] Log: TCP Tick DNS lookup
[0009.66] Log: TCP AInternetLink Resolve success
[0009.66] ScriptLog: [TcpLinkClient] resolved to 54.169.208.63:4646
[0009.66] Log: Host addr is WIFI: 169.254.23.45
[0009.66] Log: TCP BindPort with NewSocket at 0.0.0.0
[0009.66] Log: TCP SetIp FInternetIpAddr for 0.0.0.0
[0009.66] Log: TCP SetIp in_addr
[0009.66] Log: TCP Using IPv4 address: 0.0.0.0  on an ipv6 socket
[0009.66] Log: TCP Bind for 0.0.0.0:0 result: 1
[0009.66] ScriptLog: [TcpLinkClient] Bound to port: 60885
[0009.66] Log: TCP Open with 54.169.208.63
[0009.66] Log: TCP SetIp with INT value: 917098559
[0009.66] Log: TCP SetIp in_addr
[0009.66] Log: TCP Using IPv4 address: 54.169.208.63  on an ipv6 socket
[0009.66] Log: TCP Connect to with V6 [::ffff:54.169.208.63]:4646
[0009.66] Log: TCP ERROR Connect with result: SE_ENETUNREACH

我从未使用IPv6协议，也没有使用低级套接字连接，所以我在这里迷失了方向。这是否会导致客户端问题？ DNS查找问题？服务器不接受IPv6客户端？

提前致谢！

Answer 1

在设备上进行了多次测试之后，我就让它工作了。

＆＃xA;＆＃xA;

问题来自DNS的缓存，即返回过时的IP以及调用getaddrinfo （）。添加端口参数时，它在DNS中触发了正确的寄存器：IPv4用于IPv6，用于IPv6用于AAAA。

＆＃xA;＆＃xA;

这是适用于IPv4和IPv6的呼叫：< / p>＆＃XA;＆＃XA;

 <代码> FInternetAddrBSDIPv6＆安培; Addr;＆＃xA; struct addrinfo * res，* res0;＆＃xA;＆＃xA; //我们只对IPv6地址感兴趣。＆＃xA; addrinfo HintAddrInfo;＆＃xA; appMemzero（＆amp; HintAddrInfo，sizeof （HintAddrInfo））;＆＃xA;＆＃xA; HintAddrInfo.ai_family = AF_UNSPEC;＆＃xA; HintAddrInfo.ai_socktype = SOCK_STREAM;＆＃xA; // HintAddrInfo.ai_protocol = IPPROTO_TCP;＆＃xA; HintAddrInfo.ai_flags = AI_DEFAULT ;＆＃xA;＆＃xA; INT ErrorCode = SE_HOST_NOT_FOUND;＆＃xA; ErrorCode = getaddrinfo（HostName，“1212”，＆amp; HintAddrInfo，＆amp; res0）;＆＃xA;＆＃xA; if（ErrorCode == SE_NO_ERROR）＆＃XA; {＆＃XA; for（res = res0; res; res = res-＆gt; ai_next）＆＃xA; {＆＃XA; debugf（TEXT（“TCP GetHostByName与DNS成功”））;＆＃xA;＆＃xA; if（res-＆gt; ai_addr！= 0）＆＃xA; {＆＃XA; if（res-> ai_family == AF_INET6）＆＃xA; {＆＃XA; struct sockaddr_in6 input_socket6;＆＃xA; memset（＆amp; input_socket6,0，sizeof（struct sockaddr_in6））;＆＃xA; memcpy（＆amp; input_socket6，res-＆gt; ai_addr，res-＆gt; ai_addrlen）;＆＃xA;＆＃xA; Addr.SetIp（input_socket6.sin6_addr）;＆＃XA; ErrorCode = 0; //很高兴。＆＃xA;打破;＆＃XA; }＆＃XA;否则if（res-> ai_family == AF_INET）＆＃xA; {＆＃XA; const in_addr＆amp; IP =（（sockaddr_in *）res-＆gt; ai_addr） - ＆gt; sin_addr;＆＃xA; Addr.SetIp（IP）;＆＃XA; ErrorCode = 0; //很高兴。＆＃xA;打破;＆＃XA; }＆＃XA; }＆＃XA;＆＃XA; }＆＃xA;}＆＃xA;＆＃xA; freeaddrinfo（res0）;＆＃xA;＆＃xA;返回ErrorCode;＆＃xA;

＆＃xA;

带有NAT64网络的IPv6套接字

1 个答案: