public Task HandleDnsConnection(InConnectionDns dns)
{
var req = dns.DnsRequest;
var name = TryGetName(req.Name);
if (name == null)
{
dns.RedirectTo(if_notmatch);
return(NaiveUtils.CompletedTask);
}
if (name.Length == 0 || name == list_name)
{
return(dns.SetResult(new DnsResponse(this, new IPAddress((long)listIp))));
}
var clis = FindClientsByName(name);
if (clis.Count > 0)
{
return(dns.SetResult(new DnsResponse(this, clis.Select(x => x.Ip).ToArray())));
}
else
{
if (if_notfound == null)
{
return(dns.SetResult(DnsResponse.Empty(this)));
}
dns.RedirectTo(if_notfound);
return(NaiveUtils.CompletedTask);
}
}
public async Task <DnsResponse> ResolveName(IAdapter creator, AdapterRef handler, DnsRequest request)
{
var cxn = InConnectionDns.Create(creator, request);
await HandleInConnection(cxn, handler);
var result = cxn.ConnectResult;
if (result?.Ok == false)
{
if (result.FailedReason != null)
{
throw new Exception(result.FailedReason);
}
throw new Exception("name resolving failed.");
}
return(result as DnsResponse ?? DnsResponse.Empty(this));
}
private async Task ResolveName(InConnectionDns cxn)
{
var name = cxn.Dest.Host;
var req = dnsClient.Create();
var domain = new Domain(name);
req.Questions.Add(new Question(domain, cxn.RequestType != DnsRequestType.AAAA ? RecordType.A : RecordType.AAAA));
req.OperationCode = OperationCode.Query;
req.RecursionDesired = true;
IResponse r;
try {
r = await req.Resolve();
} catch (ResponseException e) {
var emptyResp = DnsResponse.Empty(this);
emptyResp.Result = ConnectResultEnum.Failed;
emptyResp.FailedReason = e.Message;
await cxn.SetResult(emptyResp);
return;
}
if (r.ResponseCode != ResponseCode.NoError)
{
Logger.warning("resolving " + name + ": server returns " + r.ResponseCode);
}
int count = 0;
foreach (var item in r.AnswerRecords)
{
if (item.Type == RecordType.A || item.Type == RecordType.AAAA)
{
count++;
}
}
if (count == 0)
{
if (r.AnswerRecords.Count == 0)
{
Logger.warning("resolving " + name + ": no answer records");
}
else
{
Logger.warning("resolving " + name + ": answer records without A/AAAA records");
}
}
var arr = new IPAddress[count];
int?ttl = null;
int cur = 0;
foreach (var item in r.AnswerRecords)
{
if (item.Type == RecordType.A || item.Type == RecordType.AAAA)
{
arr[cur++] = ((IPAddressResourceRecord)item).IPAddress;
int newTtl = (int)item.TimeToLive.TotalSeconds;
ttl = ttl.HasValue ? Math.Min(newTtl, ttl.Value) : newTtl;
}
}
var resp = new DnsResponse(this, arr)
{
TTL = ttl
};
await cxn.SetResult(resp);
}