public void Configure(IApplicationBuilder app, IHostEnvironment env)
{
int staticFilesCachePeriod;
if (env.IsDevelopment())
{
staticFilesCachePeriod = 60;
app.UseDeveloperExceptionPage();
}
else
{
staticFilesCachePeriod = 14400;
}
app.UseDefaultFiles();
app.UseStaticFiles(new StaticFileOptions()
{
OnPrepareResponse = delegate(StaticFileResponseContext ctx)
{
ctx.Context.Response.Headers.Append("Cache-Control", $"public, max-age={staticFilesCachePeriod}");
}
});
app.Run(async(context) =>
{
HttpRequest request = context.Request;
HttpResponse response = context.Response;
if (request.Path == "/api/dnsclient/")
{
try
{
string server = request.Query["server"];
string domain = request.Query["domain"];
DnsResourceRecordType type = (DnsResourceRecordType)Enum.Parse(typeof(DnsResourceRecordType), request.Query["type"], true);
domain = domain.Trim();
if (domain.EndsWith("."))
{
domain = domain.Substring(0, domain.Length - 1);
}
bool preferIpv6 = Configuration.GetValue <bool>("PreferIpv6");
bool randomizeName = false;
bool qnameMinimization = false;
int retries = Configuration.GetValue <int>("Retries");
int timeout = Configuration.GetValue <int>("Timeout");
DnsDatagram dnsResponse;
if (server == "recursive-resolver")
{
DnsQuestionRecord question;
if ((type == DnsResourceRecordType.PTR) && IPAddress.TryParse(domain, out IPAddress address))
{
question = new DnsQuestionRecord(address, DnsClass.IN);
}
else
{
question = new DnsQuestionRecord(domain, type, DnsClass.IN);
}
dnsResponse = await DnsClient.RecursiveResolveAsync(question, null, null, preferIpv6, randomizeName, qnameMinimization, retries, timeout);
}
else
{
DnsTransportProtocol protocol = (DnsTransportProtocol)Enum.Parse(typeof(DnsTransportProtocol), request.Query["protocol"], true);
if ((protocol == DnsTransportProtocol.Tls) && !server.Contains(":853"))
{
server += ":853";
}
NameServerAddress nameServer = new NameServerAddress(server, protocol);
if (nameServer.IPEndPoint == null)
{
await nameServer.ResolveIPAddressAsync(null, null, preferIpv6);
}
else if (nameServer.DomainEndPoint == null)
{
try
{
await nameServer.ResolveDomainNameAsync(null, null, preferIpv6);
}
catch
{ }
}
DnsClient dnsClient = new DnsClient(nameServer);
dnsClient.PreferIPv6 = preferIpv6;
dnsClient.RandomizeName = randomizeName;
dnsClient.Retries = retries;
dnsClient.Timeout = timeout;
dnsResponse = await dnsClient.ResolveAsync(domain, type);
}
string jsonResponse = JsonConvert.SerializeObject(dnsResponse, new StringEnumConverter());
response.Headers.Add("Content-Type", "application/json; charset=utf-8");
await response.WriteAsync("{\"status\":\"ok\", \"response\":" + jsonResponse + "}");
}
catch (Exception ex)
{
string jsonResponse = JsonConvert.SerializeObject(ex);
response.Headers.Add("Content-Type", "application/json; charset=utf-8");
await response.WriteAsync("{\"status\":\"error\", \"response\":" + jsonResponse + "}");
}
}
});
}
