如何在iOS中获取域名的名称

Question

我想解析一个域名并获取其CNAME和ip信息，如下所示：

example.com -> cname.com -> ip地址

我搜索了很多，知道如何获取ip地址，例如通过CFHost。但我仍然不知道如何获得其他信息，比如它的CNAME。

我应该用CFHost还是别的什么来做这件事？

Answer 1

您可以使用以下代码来实现您的目的

    + (void) getCNAME {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    DNSServiceRef serviceRef;
    DNSServiceErrorType error;
    error = DNSServiceQueryRecord(&serviceRef, 0, 0, "apple.com", kDNSServiceType_CNAME,
                                  kDNSServiceClass_IN, queryCallback, NULL);
    if (error != kDNSServiceErr_NoError){
        NSLog(@"DNS Service error");
    }

    DNSServiceProcessResult(serviceRef);
    DNSServiceRefDeallocate(serviceRef);
});}

static void queryCallback(DNSServiceRef sdRef,
                      DNSServiceFlags flags,
                      uint32_t interfaceIndex,
                      DNSServiceErrorType errorCode,
                      const char *fullname,
                      uint16_t rrtype,
                      uint16_t rrclass,
                      uint16_t rdlen,
                      const void *rdata,
                      uint32_t ttl,
                      void *context) {

if (errorCode == kDNSServiceErr_NoError && rdlen > 1) {
    NSMutableData *txtData = [NSMutableData dataWithCapacity:rdlen];

    for (uint16_t i = 1; i < rdlen; i += 256) {
        [txtData appendBytes:rdata + i length:MIN(rdlen - i, 255)];
    }

    NSString *theTXT = [[NSString alloc] initWithBytes:txtData.bytes length:txtData.length encoding:NSASCIIStringEncoding];
    NSLog(@"CNAME: %@", theTXT);
}}