/// <summary>
///
/// </summary>
/// <param name="dnsServer"></param>
/// <param name="host"></param>
/// <param name="queryType"></param>
/// <param name="queryClass"></param>
/// <param name="protocol"></param>
/// <param name="messageSecurityProvider">The instance of the message security provider to use to secure the DNS request.</param>
/// <returns>A <see cref="T:DnDns.Net.Dns.DnsQueryResponse"></see> instance that contains the Dns Answer for the request query.</returns>
/// <PermissionSet>
/// <IPermission class="System.Net.DnsPermission, System, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" />
/// </PermissionSet>
public async Task <DnsQueryResponse> Resolve(string dnsServer, string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
byte[] bDnsQuery = this.BuildDnsRequest(host, queryType, queryClass, protocol, messageSecurityProvider);
new System.Net.Sockets.Socket(System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp).Dispose();
// Connect to DNS server and get the record for the current server.
IPHostEntry ipe = await Dns.GetHostEntryAsync(dnsServer);
IPAddress ipa = ipe.AddressList[0];
IPEndPoint ipep = new IPEndPoint(ipa, (int)UdpServices.Domain);
byte[] recvBytes = null;
switch (protocol)
{
case ProtocolType.Tcp:
{
recvBytes = await ResolveTcp(bDnsQuery, ipep);
break;
}
case ProtocolType.Udp:
{
recvBytes = await ResolveUdp(bDnsQuery, ipep);
break;
}
default:
{
throw new InvalidOperationException("Invalid Protocol: " + protocol);
}
}
DnsQueryResponse dnsQR = new DnsQueryResponse();
dnsQR.ParseResponse(recvBytes, protocol);
return(dnsQR);
}
private byte[] BuildDnsRequest(string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
// Combind the NsFlags with our constant flags
ushort flags = (ushort)((ushort)_queryResponse | (ushort)_opCode | (ushort)_nsFlags);
this._flags = flags;
//NOTE: This limits the librarys ablity to issue multiple queries per request.
this._nsType = queryType;
this._nsClass = queryClass;
this._name = host;
if (messageSecurityProvider != null)
{
messageSecurityProvider.SecureMessage(this);
}
byte[] bDnsQuery = GetMessageBytes();
// Add two byte prefix that contains the packet length per RFC 1035 section 4.2.2
if (protocol == ProtocolType.Tcp)
{
// 4.2.2. TCP usageMessages sent over TCP connections use server port 53 (decimal).
// The message is prefixed with a two byte length field which gives the message
// length, excluding the two byte length field. This length field allows the
// low-level processing to assemble a complete message before beginning to parse
// it.
int len = bDnsQuery.Length;
Array.Resize <byte>(ref bDnsQuery, len + 2);
Array.Copy(bDnsQuery, 0, bDnsQuery, 2, len);
bDnsQuery[0] = (byte)((len >> 8) & 0xFF);
bDnsQuery[1] = (byte)((len & 0xFF));
}
return(bDnsQuery);
}
/// <summary>
///
/// </summary>
/// <param name="dnsServer"></param>
/// <param name="host"></param>
/// <param name="queryType"></param>
/// <param name="queryClass"></param>
/// <param name="protocol"></param>
/// <param name="messageSecurityProvider">The instance of the message security provider to use to secure the DNS request.</param>
/// <returns>A <see cref="T:DnDns.Net.Dns.DnsQueryResponse"></see> instance that contains the Dns Answer for the request query.</returns>
/// <PermissionSet>
/// <IPermission class="System.Net.DnsPermission, System, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" />
/// </PermissionSet>
public DnsQueryResponse Resolve(string dnsServer, string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
// Do stack walk and Demand all callers have DnsPermission.
// FIXME _dnsPermissions.Demand();
DnsQueryResponse dnsQR = new DnsQueryResponse();
// Try a native query if it is supported.
if (Tools.HasSystemDns)
// CS0162 will fire when HasSystemDns is a constant.
#pragma warning disable 162
{
// See https://www.dns-oarc.net/oarc/services/replysizetest - 4k likely plenty.
byte[] answer = new byte[4096];
int answerSize = Tools.SystemResQuery(host, queryClass, queryType, answer);
if (0 < answerSize)
{
dnsQR.ParseResponse(answer, answerSize);
return(dnsQR);
}
else
{
return(null);
}
}
byte[] recvBytes = null;
byte[] bDnsQuery = this.BuildDnsRequest(host, queryType, queryClass, protocol, messageSecurityProvider);
IPAddress[] ipas = System.Net.Dns.GetHostAddresses(dnsServer);
IPEndPoint ipep = null;
foreach (var addr in ipas)
{
if (addr.AddressFamily == AddressFamily.InterNetwork)
{
ipep = new IPEndPoint(addr, (int)UdpServices.Domain);
break;
}
}
if (null == ipep)
{
throw new Exception(string.Format("No IPv4 address found for hostname {0}", dnsServer));
}
switch (protocol)
{
case ProtocolType.Tcp:
{
recvBytes = ResolveTcp(bDnsQuery, ipep);
break;
}
case ProtocolType.Udp:
{
recvBytes = ResolveUdp(bDnsQuery, ipep);
break;
}
default:
{
throw new InvalidOperationException("Invalid Protocol: " + protocol);
}
}
Trace.Assert(recvBytes != null, "Failed to retrieve data from the remote DNS server.");
dnsQR.ParseResponse(recvBytes);
return(dnsQR);
}
private byte[] BuildDnsRequest(string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
// Combind the NsFlags with our constant flags
ushort flags = (ushort)((ushort)_queryResponse | (ushort)_opCode | (ushort)_nsFlags);
this._flags = flags;
//NOTE: This limits the librarys ablity to issue multiple queries per request.
this._nsType = queryType;
this._nsClass = queryClass;
this._name = host;
if(messageSecurityProvider != null)
{
messageSecurityProvider.SecureMessage(this);
}
byte[] bDnsQuery = GetMessageBytes();
// Add two byte prefix that contains the packet length per RFC 1035 section 4.2.2
if (protocol == ProtocolType.Tcp)
{
// 4.2.2. TCP usageMessages sent over TCP connections use server port 53 (decimal).
// The message is prefixed with a two byte length field which gives the message
// length, excluding the two byte length field. This length field allows the
// low-level processing to assemble a complete message before beginning to parse
// it.
int len = bDnsQuery.Length;
Array.Resize<byte>(ref bDnsQuery, len + 2);
Array.Copy(bDnsQuery, 0, bDnsQuery, 2, len);
bDnsQuery[0] = (byte)((len >> 8) & 0xFF);
bDnsQuery[1] = (byte)((len & 0xFF));
}
return bDnsQuery;
}
/// <summary>
///
/// </summary>
/// <param name="dnsServer"></param>
/// <param name="host"></param>
/// <param name="queryType"></param>
/// <param name="queryClass"></param>
/// <param name="protocol"></param>
/// <param name="messageSecurityProvider">The instance of the message security provider to use to secure the DNS request.</param>
/// <returns>A <see cref="T:DnDns.Net.Dns.DnsQueryResponse"></see> instance that contains the Dns Answer for the request query.</returns>
/// <PermissionSet>
/// <IPermission class="System.Net.DnsPermission, System, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" />
/// </PermissionSet>
public DnsQueryResponse Resolve(string dnsServer, string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
// Do stack walk and Demand all callers have DnsPermission.
_dnsPermissions.Demand();
byte[] bDnsQuery = this.BuildDnsRequest(host, queryType, queryClass, protocol, messageSecurityProvider);
// Connect to DNS server and get the record for the current server.
IPHostEntry ipe = System.Net.Dns.GetHostEntry(dnsServer);
IPAddress ipa = ipe.AddressList[0];
IPEndPoint ipep = new IPEndPoint(ipa, (int)UdpServices.Domain);
byte[] recvBytes = null;
switch (protocol)
{
case ProtocolType.Tcp:
{
recvBytes = ResolveTcp(bDnsQuery, ipep);
break;
}
case ProtocolType.Udp:
{
recvBytes = ResolveUdp(bDnsQuery, ipep);
break;
}
default:
{
throw new InvalidOperationException("Invalid Protocol: " + protocol);
}
}
Trace.Assert(recvBytes != null, "Failed to retrieve data from the remote DNS server.");
DnsQueryResponse dnsQR = new DnsQueryResponse();
dnsQR.ParseResponse(recvBytes, protocol);
return dnsQR;
}
/// <summary>
///
/// </summary>
/// <param name="dnsServer"></param>
/// <param name="host"></param>
/// <param name="queryType"></param>
/// <param name="queryClass"></param>
/// <param name="protocol"></param>
/// <param name="messageSecurityProvider">The instance of the message security provider to use to secure the DNS request.</param>
/// <returns>A <see cref="T:DnDns.Net.Dns.DnsQueryResponse"></see> instance that contains the Dns Answer for the request query.</returns>
/// <PermissionSet>
/// <IPermission class="System.Net.DnsPermission, System, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" />
/// </PermissionSet>
public DnsQueryResponse Resolve(string dnsServer, string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
// Do stack walk and Demand all callers have DnsPermission.
_dnsPermissions.Demand();
byte[] bDnsQuery = this.BuildDnsRequest(host, queryType, queryClass, protocol, messageSecurityProvider);
// Connect to DNS server and get the record for the current server.
IPHostEntry ipe = System.Net.Dns.GetHostEntry(dnsServer);
IPAddress ipa = ipe.AddressList[0];
IPEndPoint ipep = new IPEndPoint(ipa, (int)UdpServices.Domain);
byte[] recvBytes = null;
switch (protocol)
{
case ProtocolType.Tcp:
{
recvBytes = ResolveTcp(bDnsQuery, ipep);
break;
}
case ProtocolType.Udp:
{
recvBytes = ResolveUdp(bDnsQuery, ipep);
break;
}
default:
{
throw new InvalidOperationException("Invalid Protocol: " + protocol);
}
}
Trace.Assert(recvBytes != null, "Failed to retrieve data from the remote DNS server.");
DnsQueryResponse dnsQR = new DnsQueryResponse();
dnsQR.ParseResponse(recvBytes, protocol);
return(dnsQR);
}
/// <summary>
///
/// </summary>
/// <param name="dnsServer"></param>
/// <param name="host"></param>
/// <param name="queryType"></param>
/// <param name="queryClass"></param>
/// <param name="protocol"></param>
/// <param name="messageSecurityProvider">The instance of the message security provider to use to secure the DNS request.</param>
/// <returns>A <see cref="T:DnDns.Net.Dns.DnsQueryResponse"></see> instance that contains the Dns Answer for the request query.</returns>
/// <PermissionSet>
/// <IPermission class="System.Net.DnsPermission, System, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" />
/// </PermissionSet>
public DnsQueryResponse Resolve(string dnsServer, string host, NsType queryType, NsClass queryClass, ProtocolType protocol, IMessageSecurityProvider messageSecurityProvider)
{
// Do stack walk and Demand all callers have DnsPermission.
// FIXME _dnsPermissions.Demand();
DnsQueryResponse dnsQR = new DnsQueryResponse();
// Try a native query if it is supported.
if (Tools.HasSystemDns)
// CS0162 will fire when HasSystemDns is a constant.
#pragma warning disable 162
{
// See https://www.dns-oarc.net/oarc/services/replysizetest - 4k likely plenty.
byte[] answer = new byte[4096];
int answerSize = Tools.SystemResQuery (host, queryClass, queryType, answer);
if (0 < answerSize) {
dnsQR.ParseResponse (answer, answerSize);
return dnsQR;
} else {
return null;
}
}
byte[] recvBytes = null;
byte[] bDnsQuery = this.BuildDnsRequest(host, queryType, queryClass, protocol, messageSecurityProvider);
IPAddress[] ipas = System.Net.Dns.GetHostAddresses (dnsServer);
IPEndPoint ipep = null;
foreach (var addr in ipas) {
if (addr.AddressFamily == AddressFamily.InterNetwork) {
ipep = new IPEndPoint(addr, (int)UdpServices.Domain);
break;
}
}
if (null == ipep) {
throw new Exception (string.Format ("No IPv4 address found for hostname {0}", dnsServer));
}
switch (protocol)
{
case ProtocolType.Tcp:
{
recvBytes = ResolveTcp(bDnsQuery, ipep);
break;
}
case ProtocolType.Udp:
{
recvBytes = ResolveUdp(bDnsQuery, ipep);
break;
}
default:
{
throw new InvalidOperationException("Invalid Protocol: " + protocol);
}
}
Trace.Assert(recvBytes != null, "Failed to retrieve data from the remote DNS server.");
dnsQR.ParseResponse(recvBytes);
return dnsQR;
}
