我正在使用 Apple 的 TCPServer 类在传入连接监听时打开一个套接字。这是当有人连接到监听套接字时调用的回调:

static void TCPServerAcceptCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) {
TCPServer *server = (TCPServer *)info;
if (kCFSocketAcceptCallBack == type) { 
    // for an AcceptCallBack, the data parameter is a pointer to a CFSocketNativeHandle
    CFSocketNativeHandle nativeSocketHandle = *(CFSocketNativeHandle *)data;
    uint8_t name[SOCK_MAXADDRLEN];
    socklen_t namelen = sizeof(name);
    NSData *peer = nil;
    if (0 == getpeername(nativeSocketHandle, (struct sockaddr *)name, &namelen)) {
        peer = [NSData dataWithBytes:name length:namelen];
    }

    CFReadStreamRef readStream = NULL;
    CFWriteStreamRef writeStream = NULL;
    CFStreamCreatePairWithSocket(kCFAllocatorDefault, nativeSocketHandle, &readStream, &writeStream);
    if (readStream && writeStream) {
        CFReadStreamSetProperty(readStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue);
        CFWriteStreamSetProperty(writeStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue);
        [server handleNewConnectionFromAddress:peer inputStream:(NSInputStream *)readStream outputStream:(NSOutputStream *)writeStream];
    } else {
        // on any failure, need to destroy the CFSocketNativeHandle 
        // since we are not going to use it any more
        close(nativeSocketHandle);
    }
    if (readStream) CFRelease(readStream);
    if (writeStream) CFRelease(writeStream);
}
}

有没有办法获取正在连接的设备的主机名？ 问候， 科萨

[编辑] 我试过这样的方法来提取 ip:

struct sockaddr_in *s = (struct sockaddr_in*)name;
char *ipstr = malloc(INET_ADDRSTRLEN);         
ipstr = inet_ntoa(s->sin_addr);

NSLog(@"ip = %s", ipstr);

但它给了我 0.0.0.0。

[编辑] 仍在努力，但仍然没有成功。根据苹果的文档，地址参数是:

一个 CFData 对象，其中包含适合 s 协议(protocol)族(例如 struct sockaddr_in 或 struct sockaddr_in6)的 struct sockaddr 的内容，标识 s 所连接的远程地址。除了 kCFSocketAcceptCallBack 和 kCFSocketDataCallBack 回调之外，该值为 NULL。

但是我无法提取除 132.20.0.1 以外的任何其他 IP(这显然不是我期望的 IP)我真的很困惑，如果有人能帮助我，那就太好了!

最佳答案

在尝试按照您的方式获取地址后，我想出了一个适合我的代码的轻微变体。如果您正在处理 IPv6 地址，则此代码有效，但很容易更改为使用 IPv4。无论如何，我将不得不更改代码以同时使用两者。

- (void)getPublicClientAddress {
    // Get public IP from stream

    // Get hands on appropriate data structures via the socket number
    CFSocketNativeHandle nativeSocketHandle = _socketnumber;
    uint8_t name[SOCK_MAXADDRLEN];
    socklen_t namelen = sizeof(name);
    NSData *peer = nil;
    if (0 == getpeername(nativeSocketHandle, (struct sockaddr *)name, &namelen)) {
        peer = [NSData dataWithBytes:name length:namelen];
    }

    // TODO distiguish between ipv4 and ipv6
    struct sockaddr_in6 *s = (struct sockaddr_in6*)name;

    // convert ip to string
    char *ipstr = malloc(INET6_ADDRSTRLEN);
    struct in6_addr *ipv6addr = &s->sin6_addr;  // used pointer here, but that really should make no difference
    inet_ntop(AF_INET6, ipv6addr, ipstr, sizeof(ipstr)); // used a different function here

    // convert port to int
    int portnumber = s->sin6_port;

    // Save in properties
    _publicIP   = [NSString stringWithFormat:@"%s", ipstr];
    _publicPort = [NSString stringWithFormat:@"%d", portnumber];
}

所以这段代码对我有用，我希望它能帮助那些在寻找答案时偶然发现这篇文章的人。

关于objective-c - 获取连接到套接字的主机的主机名，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11101799/