private int IsHandle(byte[] firstPacket, int length)
{
if (length >= 7 && _config.ProxyRuleMode != ProxyRuleMode.Disable)
{
IPAddress ipAddress = null;
if (firstPacket[0] == 1)
{
var addr = new byte[4];
Array.Copy(firstPacket, 1, addr, 0, addr.Length);
ipAddress = new IPAddress(addr);
}
else if (firstPacket[0] == 3)
{
int len = firstPacket[1];
var addr = new byte[len];
if (length >= len + 2)
{
Array.Copy(firstPacket, 2, addr, 0, addr.Length);
var host = Encoding.UTF8.GetString(firstPacket, 2, len);
if (IPAddress.TryParse(host, out ipAddress))
{
//pass
}
else
{
if ((_config.ProxyRuleMode == ProxyRuleMode.BypassLanAndChina || _config.ProxyRuleMode == ProxyRuleMode.BypassLanAndNotChina) && _IPRange != null || _config.ProxyRuleMode == ProxyRuleMode.UserCustom)
{
if (!IPAddress.TryParse(host, out ipAddress))
{
if (_config.ProxyRuleMode == ProxyRuleMode.UserCustom)
{
if (HostMap.GetHost(host, out var host_addr))
{
if (!string.IsNullOrEmpty(host_addr))
{
var lower_host_addr = host_addr.ToLower();
if (lower_host_addr.StartsWith("reject") ||
lower_host_addr.StartsWith("direct")
)
{
return(CONNECT_DIRECT);
}
if (lower_host_addr.StartsWith("localproxy"))
{
return(CONNECT_LOCALPROXY);
}
if (lower_host_addr.StartsWith("remoteproxy"))
{
return(CONNECT_REMOTEPROXY);
}
if (lower_host_addr.IndexOf('.') >= 0 || lower_host_addr.IndexOf(':') >= 0)
{
if (!IPAddress.TryParse(lower_host_addr, out ipAddress))
{
//
}
}
}
}
}
if (ipAddress == null)
{
ipAddress = DnsUtil.DnsBuffer.Get(host);
}
}
if (ipAddress == null)
{
ipAddress = DnsUtil.QueryDns(host);
if (ipAddress != null)
{
DnsUtil.DnsBuffer.Set(host, new IPAddress(ipAddress.GetAddressBytes()));
if (host.IndexOf('.') >= 0 && IPSubnet.IsLan(ipAddress))
{
// assume that it is pollution if return LAN address
return(CONNECT_REMOTEPROXY);
}
}
else
{
Logging.Log(LogLevel.Debug, "DNS query fail: " + host);
}
}
}
}
}
}
else if (firstPacket[0] == 4)
{
var addr = new byte[16];
Array.Copy(firstPacket, 1, addr, 0, addr.Length);
ipAddress = new IPAddress(addr);
}
if (ipAddress != null)
{
if (_config.ProxyRuleMode == ProxyRuleMode.UserCustom)
{
if (HostMap.GetIP(ipAddress, out var host_addr))
{
var lower_host_addr = host_addr.ToLower();
if (lower_host_addr.StartsWith("reject") ||
lower_host_addr.StartsWith("direct")
)
{
return(CONNECT_DIRECT);
}
if (lower_host_addr.StartsWith("localproxy"))
{
return(CONNECT_LOCALPROXY);
}
if (lower_host_addr.StartsWith("remoteproxy"))
{
return(CONNECT_REMOTEPROXY);
}
}
}
else
{
if (IPSubnet.IsLan(ipAddress))
{
return(CONNECT_DIRECT);
}
if (_config.ProxyRuleMode is ProxyRuleMode.BypassLanAndChina or ProxyRuleMode.BypassLanAndNotChina && _IPRange is not null)
{
if (_IPRange.IsInIPRange(ipAddress))
{
return(CONNECT_LOCALPROXY);
}
DnsUtil.DnsBuffer.Sweep();
}
}
}
}
return(CONNECT_REMOTEPROXY);
}
