public Task <DNS.Protocol.IResponse> Resolve(DNS.Protocol.IRequest request, CancellationToken cancellationToken = default)
{
DNS.Protocol.IResponse response = DNS.Protocol.Response.FromRequest(request);
foreach (var question in response.Questions)
{
if (question.Type == DNS.Protocol.RecordType.A)
{
var client = new DnsClient.LookupClient(DnsClient.NameServer.GooglePublicDns);
client.UseTcpOnly = true;
client.UseCache = true;
try
{
var result = client.Query(question.Name.ToString(), DnsClient.QueryType.A);
foreach (var item in result.Answers.ARecords())
{
response.AnswerRecords.Add(new DNS.Protocol.ResourceRecords.IPAddressResourceRecord(question.Name, item.Address));
}
}
catch (Exception)
{
// 跳过
}
}
else if (question.Type == DNS.Protocol.RecordType.AAAA)
{
var client = new DnsClient.LookupClient(DnsClient.NameServer.GooglePublicDns);
client.UseTcpOnly = true;
client.UseCache = true;
try
{
var result = client.Query(question.Name.ToString(), DnsClient.QueryType.AAAA);
foreach (var item in result.Answers.AaaaRecords())
{
response.AnswerRecords.Add(new DNS.Protocol.ResourceRecords.IPAddressResourceRecord(question.Name, item.Address));
}
}
catch (Exception)
{
// 跳过
}
}
else
{
// 跳过
}
}
return(Task.FromResult(response));
}
/// <summary>
/// Applies the custom host resolver rules to override DNS requests.
/// </summary>
/// <param name="value">The given value for the host-resolver-rules parameter</param>
/// <param name="settings"></param>
private void handleHostResolverRules(string value, ref CefSettings settings)
{
if (value == null)
{
return;
}
// resolve domains with set DNS server if necessary
List <string> parts = new List <string>();
var rules = value.Split(',');
foreach (var rule in rules)
{
if (!rule.Contains("{{"))
{
parts.Add(rule);
continue;
}
string r = rule.Trim().ToLower();
if (!r.StartsWith("map"))
{
parts.Add(rule);
continue;
}
string domain = Common.GetTextBetween(rule.ToLower(), "map ", " {{").Trim();
string dnsAddress = Tools.Common.GetTextBetween(rule, "{{", "}}");
int port = 53; // default DNS port
string ip_string = null;
if (dnsAddress.Contains(":"))
{
var addressParts = dnsAddress.Split(':');
ip_string = addressParts[0].Trim();
string port_string = addressParts[1];
if (!int.TryParse(port_string, out port))
{
Logger.Log("Ignored invalid value for parameter host-resolver-rules, a port was not a valid number");
return;
}
}
else
{
ip_string = dnsAddress.Trim();
}
IPAddress ipAddress = null;
if (!IPAddress.TryParse(ip_string, out ipAddress))
{
Logger.Log("Ignored invalid value for parameter host-resolver-rules, a port was not a valid number");
return;
}
var endpoint = new IPEndPoint(ipAddress, port);
var lookup = new DnsClient.LookupClient(endpoint);
var result = lookup.Query(domain, DnsClient.QueryType.A);
if (result.Answers.Count <= 0)
{
Logger.Log("No ip address found for domain '" + domain + "', ignoring setting for it");
continue;
}
string replace = Common.GetTextBetween(rule, "{{", "}}");
string replacement = (result.Answers[0] as DnsClient.Protocol.ARecord).Address.ToString();
string finalRule = rule.Replace("{{" + replace + "}}", replacement);
parts.Add(finalRule);
}
// rebuild setting with replacements
StringBuilder sb = new StringBuilder();
for (int i = 0; i < parts.Count; i++)
{
var part = parts[i];
sb.Append(part);
if (i < parts.Count - 1)
{
sb.Append(", ");
}
}
string setting = sb.ToString();
settings.CefCommandLineArgs.Add("host-resolver-rules", setting);
}