Files
DnsServer/DnsServerCore/Zone.cs

1367 lines
49 KiB
C#

/*
Technitium DNS Server
Copyright (C) 2019 Shreyas Zare (shreyas@technitium.com)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using TechnitiumLibrary.Net.Dns;
namespace DnsServerCore
{
public class Zone
{
#region variables
const uint DEFAULT_RECORD_TTL = 60u;
readonly bool _authoritativeZone;
readonly Zone _parentZone;
readonly string _zoneLabel;
readonly string _zoneName;
bool _disabled;
readonly ConcurrentDictionary<string, Zone> _zones = new ConcurrentDictionary<string, Zone>();
readonly ConcurrentDictionary<DnsResourceRecordType, DnsResourceRecord[]> _entries = new ConcurrentDictionary<DnsResourceRecordType, DnsResourceRecord[]>();
string _serverDomain;
uint _serveStaleTtl;
#endregion
#region constructor
public Zone(bool authoritativeZone)
{
_authoritativeZone = authoritativeZone;
_zoneName = "";
if (!_authoritativeZone)
LoadRootHintsInCache();
}
private Zone(Zone parentZone, string zoneLabel)
{
_authoritativeZone = parentZone._authoritativeZone;
_parentZone = parentZone;
_zoneLabel = zoneLabel;
string zoneName = zoneLabel;
if (_parentZone._zoneName != "")
zoneName += "." + _parentZone._zoneName;
_zoneName = zoneName;
}
#endregion
#region private
private void LoadRootHintsInCache()
{
List<DnsResourceRecord> nsRecords = new List<DnsResourceRecord>(13);
foreach (NameServerAddress rootNameServer in DnsClient.ROOT_NAME_SERVERS_IPv4)
{
nsRecords.Add(new DnsResourceRecord("", DnsResourceRecordType.NS, DnsClass.IN, 172800, new DnsNSRecord(rootNameServer.Host)));
CreateZone(this, rootNameServer.Host).SetRecords(DnsResourceRecordType.A, new DnsResourceRecord[] { new DnsResourceRecord(rootNameServer.Host, DnsResourceRecordType.A, DnsClass.IN, 172800, new DnsARecord(rootNameServer.IPEndPoint.Address)) });
}
foreach (NameServerAddress rootNameServer in DnsClient.ROOT_NAME_SERVERS_IPv6)
{
CreateZone(this, rootNameServer.Host).SetRecords(DnsResourceRecordType.AAAA, new DnsResourceRecord[] { new DnsResourceRecord(rootNameServer.Host, DnsResourceRecordType.AAAA, DnsClass.IN, 172800, new DnsAAAARecord(rootNameServer.IPEndPoint.Address)) });
}
SetRecords(DnsResourceRecordType.NS, nsRecords.ToArray());
}
private static string[] ConvertDomainToPath(string domainName)
{
DnsClient.IsDomainNameValid(domainName, true);
if (string.IsNullOrEmpty(domainName))
return new string[] { };
string[] path = domainName.ToLower().Split('.');
Array.Reverse(path);
return path;
}
internal static bool DomainEquals(string domain1, string domain2)
{
string[] path1 = ConvertDomainToPath(domain1);
string[] path2 = ConvertDomainToPath(domain2);
int maxLen;
int minLen;
if (path1.Length > path2.Length)
{
maxLen = path1.Length;
minLen = path2.Length;
}
else
{
maxLen = path2.Length;
minLen = path1.Length;
}
for (int i = 0; i < maxLen; i++)
{
if (i == minLen)
return false;
if ((path1[i] == "*") || (path2[i] == "*"))
return true;
if (path1[i] != path2[i])
return false;
}
return true;
}
private static Zone CreateZone(Zone rootZone, string domain)
{
Zone currentZone = rootZone;
string[] path = ConvertDomainToPath(domain);
for (int i = 0; i < path.Length; i++)
{
string nextZoneLabel = path[i];
Zone nextZone = currentZone._zones.GetOrAdd(nextZoneLabel, delegate (string key)
{
return new Zone(currentZone, nextZoneLabel);
});
currentZone = nextZone;
}
return currentZone;
}
private static Zone GetZone(Zone rootZone, string domain, bool authoritative)
{
Zone currentZone = rootZone;
Zone authoritativeZone = null;
if (authoritative && currentZone._entries.ContainsKey(DnsResourceRecordType.SOA))
authoritativeZone = currentZone;
string[] path = ConvertDomainToPath(domain);
for (int i = 0; i < path.Length; i++)
{
string nextZoneLabel = path[i];
if (currentZone._zones.TryGetValue(nextZoneLabel, out Zone nextZone))
{
currentZone = nextZone;
}
else
{
if (authoritative)
return authoritativeZone;
return null;
}
if (authoritative && currentZone._entries.ContainsKey(DnsResourceRecordType.SOA))
authoritativeZone = currentZone;
}
if (authoritative)
return authoritativeZone;
return currentZone;
}
private static bool DeleteZone(Zone rootZone, string domain, bool deleteSubZones)
{
Zone currentZone = GetZone(rootZone, domain, false);
if (currentZone == null)
return false;
if (!currentZone._authoritativeZone && (currentZone._zoneName.Equals("root-servers.net", StringComparison.CurrentCultureIgnoreCase)))
return false; //cannot delete root-servers.net
currentZone._entries.Clear();
DeleteSubZones(currentZone, deleteSubZones);
DeleteEmptyParentZones(currentZone);
return true;
}
private static bool DeleteSubZones(Zone currentZone, bool deleteSubZones)
{
if (currentZone._authoritativeZone)
{
if (!deleteSubZones && currentZone._entries.ContainsKey(DnsResourceRecordType.SOA))
return false; //this is a zone so return false
}
else
{
//cache zone
if (currentZone._zoneName.Equals("root-servers.net", StringComparison.CurrentCultureIgnoreCase))
return false; //cannot delete root-servers.net
}
currentZone._entries.Clear();
List<Zone> subDomainsToDelete = new List<Zone>();
foreach (KeyValuePair<string, Zone> zone in currentZone._zones)
{
if (DeleteSubZones(zone.Value, deleteSubZones))
subDomainsToDelete.Add(zone.Value);
}
foreach (Zone subDomain in subDomainsToDelete)
currentZone._zones.TryRemove(subDomain._zoneLabel, out Zone deletedValue);
return (currentZone._zones.Count == 0);
}
private static void DeleteEmptyParentZones(Zone currentZone)
{
while (currentZone._parentZone != null)
{
if ((currentZone._entries.Count > 0) || (currentZone._zones.Count > 0))
break;
currentZone._parentZone._zones.TryRemove(currentZone._zoneLabel, out Zone deletedZone);
currentZone = currentZone._parentZone;
}
}
private DnsResourceRecord[] QueryRecords(DnsResourceRecordType type, bool bypassCNAME, bool serveStale)
{
if (_authoritativeZone && (type == DnsResourceRecordType.ANY))
{
List<DnsResourceRecord> allRecords = new List<DnsResourceRecord>();
foreach (KeyValuePair<DnsResourceRecordType, DnsResourceRecord[]> entry in _entries)
allRecords.AddRange(entry.Value);
return FilterExpiredDisabledRecords(allRecords.ToArray(), serveStale);
}
if (!bypassCNAME && _entries.TryGetValue(DnsResourceRecordType.CNAME, out DnsResourceRecord[] existingCNAMERecords))
{
DnsResourceRecord[] records = FilterExpiredDisabledRecords(existingCNAMERecords, serveStale);
if (records != null)
return records;
}
if (_entries.TryGetValue(type, out DnsResourceRecord[] existingRecords))
{
DnsResourceRecord[] records = FilterExpiredDisabledRecords(existingRecords, serveStale);
if (records != null)
DnsClient.ShuffleArray(records); //shuffle records to allow load balancing
return records;
}
return null;
}
private DnsResourceRecord[] GetAllRecords(DnsResourceRecordType type, bool includeSubDomains)
{
List<DnsResourceRecord> allRecords = new List<DnsResourceRecord>();
foreach (KeyValuePair<DnsResourceRecordType, DnsResourceRecord[]> entry in _entries)
{
if (entry.Key != DnsResourceRecordType.ANY)
{
if ((type == DnsResourceRecordType.ANY) || (entry.Key == type))
allRecords.AddRange(entry.Value);
}
}
if (includeSubDomains)
{
foreach (KeyValuePair<string, Zone> zone in _zones)
{
if (!zone.Value._entries.ContainsKey(DnsResourceRecordType.SOA))
allRecords.AddRange(zone.Value.GetAllRecords(type, true));
}
}
return allRecords.ToArray();
}
private void ListAuthoritativeZones(List<Zone> zones)
{
DnsResourceRecord[] soa = QueryRecords(DnsResourceRecordType.SOA, true, false);
if (soa != null)
zones.Add(this);
foreach (KeyValuePair<string, Zone> entry in _zones)
entry.Value.ListAuthoritativeZones(zones);
}
private void SetRecords(DnsResourceRecordType type, DnsResourceRecord[] records)
{
_entries.AddOrUpdate(type, records, delegate (DnsResourceRecordType key, DnsResourceRecord[] existingRecords)
{
return records;
});
if (!_authoritativeZone)
{
//this is only applicable for cache zone
switch (type)
{
case DnsResourceRecordType.CNAME:
case DnsResourceRecordType.SOA:
case DnsResourceRecordType.NS:
//do nothing
break;
default:
//remove old CNAME entry since current new entry type overlaps any existing CNAME entry in cache
//keeping both entries will create issue with serve stale implementation since stale CNAME entry will be always returned
_entries.TryRemove(DnsResourceRecordType.CNAME, out DnsResourceRecord[] existingValues);
break;
}
}
}
private void AddRecord(DnsResourceRecord record)
{
switch (record.Type)
{
case DnsResourceRecordType.CNAME:
case DnsResourceRecordType.PTR:
case DnsResourceRecordType.SOA:
throw new DnsServerException("Cannot add record: use SetRecords() for " + record.Type.ToString() + " record");
}
_entries.AddOrUpdate(record.Type, new DnsResourceRecord[] { record }, delegate (DnsResourceRecordType key, DnsResourceRecord[] existingRecords)
{
foreach (DnsResourceRecord existingRecord in existingRecords)
{
if (record.RDATA.Equals(existingRecord.RDATA))
return existingRecords;
}
DnsResourceRecord[] newValue = new DnsResourceRecord[existingRecords.Length + 1];
existingRecords.CopyTo(newValue, 0);
newValue[newValue.Length - 1] = record;
return newValue;
});
}
private void DeleteRecord(DnsResourceRecord record)
{
if (_entries.TryGetValue(record.Type, out DnsResourceRecord[] existingRecords))
{
bool recordFound = false;
for (int i = 0; i < existingRecords.Length; i++)
{
if (record.RDATA.Equals(existingRecords[i].RDATA))
{
existingRecords[i] = null;
recordFound = true;
break;
}
}
if (!recordFound)
throw new DnsServerException("Resource record does not exists.");
if (existingRecords.Length == 1)
{
DeleteRecords(record.Type);
}
else
{
DnsResourceRecord[] newRecords = new DnsResourceRecord[existingRecords.Length - 1];
for (int i = 0, j = 0; i < existingRecords.Length; i++)
{
if (existingRecords[i] != null)
newRecords[j++] = existingRecords[i];
}
_entries.AddOrUpdate(record.Type, newRecords, delegate (DnsResourceRecordType key, DnsResourceRecord[] oldValue)
{
return newRecords;
});
}
}
}
private void DeleteRecords(DnsResourceRecordType type)
{
_entries.TryRemove(type, out DnsResourceRecord[] existingValues);
DeleteEmptyParentZones(this);
}
private DnsResourceRecord[] FilterExpiredDisabledRecords(DnsResourceRecord[] records, bool serveStale)
{
if (records.Length == 1)
{
if (!serveStale && records[0].IsStale)
return null;
if (records[0].TTLValue < 1u)
return null; //ttl expired
DnsResourceRecordInfo rrInfo = records[0].Tag as DnsResourceRecordInfo;
if ((rrInfo != null) && rrInfo.Disabled)
return null;
return records;
}
List<DnsResourceRecord> newRecords = new List<DnsResourceRecord>(records.Length);
foreach (DnsResourceRecord record in records)
{
if (!serveStale && record.IsStale)
continue;
if (record.TTLValue < 1u)
continue; //ttl expired
DnsResourceRecordInfo rrInfo = record.Tag as DnsResourceRecordInfo;
if ((rrInfo != null) && rrInfo.Disabled)
continue;
newRecords.Add(record);
}
if (newRecords.Count > 0)
return newRecords.ToArray();
return null;
}
private static Zone QueryFindClosestZone(Zone rootZone, string domain)
{
Zone currentZone = rootZone;
if (currentZone._disabled)
return currentZone;
string[] path = ConvertDomainToPath(domain);
for (int i = 0; i < path.Length; i++)
{
string nextZoneLabel = path[i];
if (currentZone._zones.TryGetValue(nextZoneLabel, out Zone nextZone))
currentZone = nextZone;
else if (currentZone._zones.TryGetValue("*", out Zone nextWildcardZone))
currentZone = nextWildcardZone;
else
return currentZone;
if (currentZone._disabled)
return currentZone;
}
return currentZone;
}
private DnsResourceRecord[] QueryClosestCachedNameServers(bool serveStale)
{
Zone currentZone = this;
DnsResourceRecord[] nsRecords = null;
while (currentZone != null)
{
nsRecords = currentZone.QueryRecords(DnsResourceRecordType.NS, true, serveStale);
if ((nsRecords != null) && (nsRecords.Length > 0) && (nsRecords[0].RDATA is DnsNSRecord))
return nsRecords;
currentZone = currentZone._parentZone;
}
return null;
}
private DnsResourceRecord[] QueryClosestAuthority(string rootZoneServerDomain)
{
Zone currentZone = this;
DnsResourceRecord[] nsRecords = null;
while (currentZone != null)
{
nsRecords = currentZone.QueryRecords(DnsResourceRecordType.SOA, true, false);
if ((nsRecords != null) && (nsRecords.Length > 0) && (nsRecords[0].RDATA as DnsSOARecord).MasterNameServer.Equals(rootZoneServerDomain, StringComparison.CurrentCultureIgnoreCase))
return nsRecords;
nsRecords = currentZone.QueryRecords(DnsResourceRecordType.NS, true, false);
if ((nsRecords != null) && (nsRecords.Length > 0))
return nsRecords;
currentZone = currentZone._parentZone;
}
return null;
}
private DnsResourceRecord[] QueryClosestAuthoritativeNameServers()
{
Zone currentZone = this;
DnsResourceRecord[] nsRecords = null;
while (currentZone != null)
{
if (currentZone._entries.ContainsKey(DnsResourceRecordType.SOA))
{
nsRecords = currentZone.QueryRecords(DnsResourceRecordType.NS, true, false);
if ((nsRecords != null) && (nsRecords.Length > 0))
return nsRecords;
return null;
}
currentZone = currentZone._parentZone;
}
return null;
}
private static DnsResourceRecord[] QueryGlueRecords(Zone rootZone, DnsResourceRecord[] nsRecords, bool serveStale)
{
List<DnsResourceRecord> glueRecords = new List<DnsResourceRecord>();
foreach (DnsResourceRecord nsRecord in nsRecords)
{
if (nsRecord.Type == DnsResourceRecordType.NS)
{
string nsDomain = (nsRecord.RDATA as DnsNSRecord).NSDomainName;
Zone zone = GetZone(rootZone, nsDomain, false);
if ((zone != null) && !zone._disabled)
{
{
DnsResourceRecord[] records = zone.QueryRecords(DnsResourceRecordType.A, true, serveStale);
if ((records != null) && (records.Length > 0))
glueRecords.AddRange(records);
}
{
DnsResourceRecord[] records = zone.QueryRecords(DnsResourceRecordType.AAAA, true, serveStale);
if ((records != null) && (records.Length > 0))
glueRecords.AddRange(records);
}
}
}
}
return glueRecords.ToArray();
}
private static DnsDatagram QueryAuthoritative(Zone rootZone, DnsDatagram request)
{
DnsQuestionRecord question = request.Question[0];
string domain = question.Name.ToLower();
Zone closestZone = QueryFindClosestZone(rootZone, domain);
if (closestZone._disabled)
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, false, false, false, DnsResponseCode.Refused, 1, 0, 0, 0), request.Question, new DnsResourceRecord[] { }, new DnsResourceRecord[] { }, new DnsResourceRecord[] { });
DnsResourceRecord[] closestAuthority = closestZone.QueryClosestAuthority(rootZone._serverDomain);
if (closestAuthority == null)
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, false, false, false, DnsResponseCode.Refused, 1, 0, 0, 0), request.Question, new DnsResourceRecord[] { }, new DnsResourceRecord[] { }, new DnsResourceRecord[] { });
if (closestAuthority[0].Type == DnsResourceRecordType.SOA)
{
//zone is hosted on this server
if (DomainEquals(closestZone._zoneName, domain))
{
//zone found
DnsResourceRecord[] records = closestZone.QueryRecords(question.Type, false, false);
if (records == null)
{
//record type not found
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, true, false, request.Header.RecursionDesired, false, false, false, DnsResponseCode.NoError, 1, 0, (ushort)closestAuthority.Length, 0), request.Question, new DnsResourceRecord[] { }, closestAuthority, new DnsResourceRecord[] { });
}
else
{
//record type found
if (closestZone._zoneName.Contains("*"))
{
DnsResourceRecord[] wildcardRecords = new DnsResourceRecord[records.Length];
for (int i = 0; i < records.Length; i++)
{
DnsResourceRecord record = records[i];
wildcardRecords[i] = new DnsResourceRecord(domain, record.Type, record.Class, record.TTLValue, record.RDATA);
}
records = wildcardRecords;
}
DnsResourceRecord[] closestAuthoritativeNameServers = null;
DnsResourceRecord[] additional;
if (question.Type != DnsResourceRecordType.ANY)
closestAuthoritativeNameServers = closestZone.QueryClosestAuthoritativeNameServers();
if (closestAuthoritativeNameServers == null)
{
closestAuthoritativeNameServers = new DnsResourceRecord[] { };
additional = new DnsResourceRecord[] { };
}
else
{
additional = QueryGlueRecords(rootZone, closestAuthoritativeNameServers, false);
}
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, true, false, request.Header.RecursionDesired, false, false, false, DnsResponseCode.NoError, 1, (ushort)records.Length, (ushort)closestAuthoritativeNameServers.Length, (ushort)additional.Length), request.Question, records, closestAuthoritativeNameServers, additional);
}
}
else
{
//zone doesnt exists
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, true, false, request.Header.RecursionDesired, false, false, false, DnsResponseCode.NameError, 1, 0, (ushort)closestAuthority.Length, 0), request.Question, new DnsResourceRecord[] { }, closestAuthority, new DnsResourceRecord[] { });
}
}
else
{
//zone is delegated
DnsResourceRecord[] additional = QueryGlueRecords(rootZone, closestAuthority, false);
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, false, false, false, DnsResponseCode.NoError, 1, 0, (ushort)closestAuthority.Length, (ushort)additional.Length), request.Question, new DnsResourceRecord[] { }, closestAuthority, additional);
}
}
private static DnsDatagram QueryCache(Zone rootZone, DnsDatagram request, bool serveStale)
{
DnsQuestionRecord question = request.Question[0];
string domain = question.Name.ToLower();
Zone closestZone = QueryFindClosestZone(rootZone, domain);
if (closestZone._zoneName.Equals(domain))
{
DnsResourceRecord[] records = closestZone.QueryRecords(question.Type, false, serveStale);
if (records != null)
{
if (records[0].RDATA is DnsEmptyRecord)
{
DnsResourceRecord[] responseAuthority;
DnsResourceRecord authority = (records[0].RDATA as DnsEmptyRecord).Authority;
if (authority == null)
responseAuthority = new DnsResourceRecord[] { };
else
responseAuthority = new DnsResourceRecord[] { authority };
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, true, false, false, DnsResponseCode.NoError, 1, 0, 1, 0), request.Question, new DnsResourceRecord[] { }, responseAuthority, new DnsResourceRecord[] { });
}
if (records[0].RDATA is DnsNXRecord)
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, true, false, false, DnsResponseCode.NameError, 1, 0, 1, 0), request.Question, new DnsResourceRecord[] { }, new DnsResourceRecord[] { (records[0].RDATA as DnsNXRecord).Authority }, new DnsResourceRecord[] { });
if (records[0].RDATA is DnsANYRecord)
{
DnsANYRecord anyRR = records[0].RDATA as DnsANYRecord;
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, true, false, false, DnsResponseCode.NoError, 1, (ushort)anyRR.Records.Length, 0, 0), request.Question, anyRR.Records, new DnsResourceRecord[] { }, new DnsResourceRecord[] { });
}
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, true, false, false, DnsResponseCode.NoError, 1, (ushort)records.Length, 0, 0), request.Question, records, new DnsResourceRecord[] { }, new DnsResourceRecord[] { });
}
}
DnsResourceRecord[] nameServers = closestZone.QueryClosestCachedNameServers(serveStale);
if (nameServers != null)
{
DnsResourceRecord[] additional = QueryGlueRecords(rootZone, nameServers, serveStale);
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, true, false, false, DnsResponseCode.NoError, 1, 0, (ushort)nameServers.Length, (ushort)additional.Length), request.Question, new DnsResourceRecord[] { }, nameServers, additional);
}
return new DnsDatagram(new DnsHeader(request.Header.Identifier, true, DnsOpcode.StandardQuery, false, false, request.Header.RecursionDesired, true, false, false, DnsResponseCode.Refused, 1, 0, 0, 0), request.Question, new DnsResourceRecord[] { }, new DnsResourceRecord[] { }, new DnsResourceRecord[] { });
}
#endregion
#region internal
internal static Dictionary<string, Dictionary<DnsResourceRecordType, List<DnsResourceRecord>>> GroupRecords(ICollection<DnsResourceRecord> records)
{
Dictionary<string, Dictionary<DnsResourceRecordType, List<DnsResourceRecord>>> groupedByDomainRecords = new Dictionary<string, Dictionary<DnsResourceRecordType, List<DnsResourceRecord>>>();
foreach (DnsResourceRecord record in records)
{
Dictionary<DnsResourceRecordType, List<DnsResourceRecord>> groupedByTypeRecords;
if (groupedByDomainRecords.ContainsKey(record.Name))
{
groupedByTypeRecords = groupedByDomainRecords[record.Name];
}
else
{
groupedByTypeRecords = new Dictionary<DnsResourceRecordType, List<DnsResourceRecord>>();
groupedByDomainRecords.Add(record.Name, groupedByTypeRecords);
}
List<DnsResourceRecord> groupedRecords;
if (groupedByTypeRecords.ContainsKey(record.Type))
{
groupedRecords = groupedByTypeRecords[record.Type];
}
else
{
groupedRecords = new List<DnsResourceRecord>();
groupedByTypeRecords.Add(record.Type, groupedRecords);
}
groupedRecords.Add(record);
}
return groupedByDomainRecords;
}
internal DnsDatagram Query(DnsDatagram request, bool serveStale = false)
{
if (_authoritativeZone)
return QueryAuthoritative(this, request);
return QueryCache(this, request, serveStale);
}
internal void CacheResponse(DnsDatagram response)
{
if (!response.Header.IsResponse)
return;
//combine all records in the response
List<DnsResourceRecord> allRecords = new List<DnsResourceRecord>();
switch (response.Header.RCODE)
{
case DnsResponseCode.NameError:
if (response.Authority.Length > 0)
{
DnsResourceRecord authority = response.Authority[0];
if (authority.Type == DnsResourceRecordType.SOA)
{
foreach (DnsQuestionRecord question in response.Question)
{
uint ttl = DEFAULT_RECORD_TTL;
if (authority.TTLValue < ttl)
ttl = authority.TTLValue;
DnsResourceRecord record = new DnsResourceRecord(question.Name, question.Type, DnsClass.IN, ttl, new DnsNXRecord(authority));
record.SetExpiry(_serveStaleTtl);
CreateZone(this, question.Name).SetRecords(question.Type, new DnsResourceRecord[] { record });
}
}
}
break;
case DnsResponseCode.NoError:
if (response.Answer.Length > 0)
{
allRecords.AddRange(response.Answer);
}
else if (response.Authority.Length > 0)
{
DnsResourceRecord authority = response.Authority[0];
if (authority.Type == DnsResourceRecordType.SOA)
{
//empty response with authority
foreach (DnsQuestionRecord question in response.Question)
{
uint ttl = DEFAULT_RECORD_TTL;
if (authority.TTLValue < ttl)
ttl = authority.TTLValue;
DnsResourceRecord record = new DnsResourceRecord(question.Name, question.Type, DnsClass.IN, ttl, new DnsEmptyRecord(authority));
record.SetExpiry(_serveStaleTtl);
CreateZone(this, question.Name).SetRecords(question.Type, new DnsResourceRecord[] { record });
}
}
else
{
foreach (DnsQuestionRecord question in response.Question)
{
foreach (DnsResourceRecord authorityRecord in response.Authority)
{
if ((authorityRecord.Type == DnsResourceRecordType.NS) && question.Name.Equals(authorityRecord.Name, StringComparison.CurrentCultureIgnoreCase) && (authorityRecord.RDATA as DnsNSRecord).NSDomainName.Equals(response.Metadata.NameServerAddress.Host, StringComparison.CurrentCultureIgnoreCase))
{
//empty response from authority name server
DnsResourceRecord record = new DnsResourceRecord(question.Name, question.Type, DnsClass.IN, DEFAULT_RECORD_TTL, new DnsEmptyRecord(null));
record.SetExpiry(_serveStaleTtl);
CreateZone(this, question.Name).SetRecords(question.Type, new DnsResourceRecord[] { record });
break;
}
}
}
}
}
else
{
//empty response with no authority
foreach (DnsQuestionRecord question in response.Question)
{
DnsResourceRecord record = new DnsResourceRecord(question.Name, question.Type, DnsClass.IN, DEFAULT_RECORD_TTL, new DnsEmptyRecord(null));
record.SetExpiry(_serveStaleTtl);
CreateZone(this, question.Name).SetRecords(question.Type, new DnsResourceRecord[] { record });
}
}
break;
default:
return; //nothing to do
}
if ((response.Question.Length > 0) && (response.Question[0].Type != DnsResourceRecordType.NS))
allRecords.AddRange(response.Authority);
allRecords.AddRange(response.Additional);
//set expiry for cached records
foreach (DnsResourceRecord record in allRecords)
record.SetExpiry(_serveStaleTtl);
SetRecords(allRecords);
//cache for ANY request
if ((response.Question[0].Type == DnsResourceRecordType.ANY) && (response.Answer.Length > 0))
{
uint ttl = DEFAULT_RECORD_TTL;
foreach (DnsResourceRecord answer in response.Answer)
{
if (answer.TTLValue < ttl)
ttl = answer.TTLValue;
}
DnsResourceRecord anyRR = new DnsResourceRecord(response.Question[0].Name, DnsResourceRecordType.ANY, DnsClass.IN, ttl, new DnsANYRecord(response.Answer));
anyRR.SetExpiry(_serveStaleTtl);
CreateZone(this, response.Question[0].Name).SetRecords(DnsResourceRecordType.ANY, new DnsResourceRecord[] { anyRR });
}
}
#endregion
#region public
public void SetRecords(string domain, DnsResourceRecordType type, uint ttl, DnsResourceRecordData[] records)
{
DnsResourceRecord[] resourceRecords = new DnsResourceRecord[records.Length];
for (int i = 0; i < records.Length; i++)
resourceRecords[i] = new DnsResourceRecord(domain, type, DnsClass.IN, ttl, records[i]);
CreateZone(this, domain).SetRecords(type, resourceRecords);
}
public void SetRecords(ICollection<DnsResourceRecord> records)
{
Dictionary<string, Dictionary<DnsResourceRecordType, List<DnsResourceRecord>>> groupedByDomainRecords = GroupRecords(records);
//add grouped records
foreach (KeyValuePair<string, Dictionary<DnsResourceRecordType, List<DnsResourceRecord>>> groupedByTypeRecords in groupedByDomainRecords)
{
string domain = groupedByTypeRecords.Key;
Zone zone = CreateZone(this, domain);
foreach (KeyValuePair<DnsResourceRecordType, List<DnsResourceRecord>> groupedRecords in groupedByTypeRecords.Value)
{
DnsResourceRecordType type = groupedRecords.Key;
DnsResourceRecord[] resourceRecords = groupedRecords.Value.ToArray();
zone.SetRecords(type, resourceRecords);
}
}
}
public void AddRecord(string domain, DnsResourceRecordType type, uint ttl, DnsResourceRecordData record)
{
DnsResourceRecord rr = new DnsResourceRecord(domain, type, DnsClass.IN, ttl, record);
CreateZone(this, domain).AddRecord(rr);
}
public void UpdateRecord(DnsResourceRecord oldRecord, DnsResourceRecord newRecord)
{
if (oldRecord.Type != newRecord.Type)
throw new DnsServerException("Cannot update record: new record must be of same type.");
if (oldRecord.Type == DnsResourceRecordType.SOA)
throw new DnsServerException("Cannot update record: use SetRecords() for updating SOA record.");
Zone currentZone = GetZone(this, oldRecord.Name, false);
if (currentZone == null)
throw new DnsServerException("Cannot update record: old record does not exists.");
switch (oldRecord.Type)
{
case DnsResourceRecordType.CNAME:
case DnsResourceRecordType.PTR:
if (oldRecord.Name.Equals(newRecord.Name, StringComparison.CurrentCultureIgnoreCase))
{
currentZone.SetRecords(newRecord.Type, new DnsResourceRecord[] { newRecord });
}
else
{
currentZone.DeleteRecords(oldRecord.Type);
CreateZone(this, newRecord.Name).SetRecords(newRecord.Type, new DnsResourceRecord[] { newRecord });
}
break;
default:
currentZone.DeleteRecord(oldRecord);
CreateZone(this, newRecord.Name).AddRecord(newRecord); //create zone since delete record will also delete empty sub zones
break;
}
}
public void DeleteRecord(string domain, DnsResourceRecordType type, DnsResourceRecordData record)
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone != null)
currentZone.DeleteRecord(new DnsResourceRecord(domain, type, DnsClass.IN, 0, record));
}
public void DeleteRecords(string domain, DnsResourceRecordType type)
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone != null)
currentZone.DeleteRecords(type);
}
public DnsResourceRecord[] GetAllRecords(string domain = "", DnsResourceRecordType type = DnsResourceRecordType.ANY, bool includeSubDomains = true, bool authoritative = false)
{
Zone currentZone = GetZone(this, domain, authoritative);
if (currentZone == null)
return new DnsResourceRecord[] { };
DnsResourceRecord[] records = currentZone.GetAllRecords(type, includeSubDomains);
if (records != null)
return records;
return new DnsResourceRecord[] { };
}
public string[] ListSubZones(string domain = "")
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone == null)
return new string[] { }; //no zone for given domain
string[] subZoneNames = new string[currentZone._zones.Keys.Count];
currentZone._zones.Keys.CopyTo(subZoneNames, 0);
return subZoneNames;
}
public ICollection<ZoneInfo> ListAuthoritativeZones(string domain = "")
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone == null)
return new ZoneInfo[] { }; //no zone for given domain
List<Zone> zones = new List<Zone>();
currentZone.ListAuthoritativeZones(zones);
List<ZoneInfo> zoneNames = new List<ZoneInfo>();
foreach (Zone zone in zones)
zoneNames.Add(new ZoneInfo(zone));
return zoneNames;
}
public bool DeleteZone(string domain, bool deleteSubZones)
{
return DeleteZone(this, domain, deleteSubZones);
}
public void DisableZone(string domain)
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone != null)
currentZone._disabled = true;
}
public void EnableZone(string domain)
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone != null)
currentZone._disabled = false;
}
public bool IsZoneDisabled(string domain)
{
Zone currentZone = GetZone(this, domain, false);
if (currentZone != null)
return currentZone._disabled;
return false;
}
public bool ZoneExists(string domain)
{
Zone currentZone = GetZone(this, domain, false);
return (currentZone != null);
}
public void Flush()
{
_zones.Clear();
_entries.Clear();
if (!_authoritativeZone)
LoadRootHintsInCache();
}
#endregion
#region properties
public bool IsAuthoritative
{ get { return _authoritativeZone; } }
public string ServerDomain
{
get { return _serverDomain; }
set { _serverDomain = value; }
}
public uint ServeStaleTtl
{
get { return _serveStaleTtl; }
set { _serveStaleTtl = value; }
}
#endregion
public class ZoneInfo : IComparable<ZoneInfo>
{
#region variables
readonly string _zoneName;
readonly bool _disabled;
#endregion
#region constructor
public ZoneInfo(string zoneName, bool disabled)
{
_zoneName = zoneName;
_disabled = disabled;
}
public ZoneInfo(Zone zone)
{
_zoneName = zone._zoneName;
_disabled = zone._disabled;
}
#endregion
#region public
public int CompareTo(ZoneInfo other)
{
return this._zoneName.CompareTo(other._zoneName);
}
#endregion
#region properties
public string ZoneName
{ get { return _zoneName; } }
public bool Disabled
{ get { return _disabled; } }
#endregion
}
public class DnsResourceRecordInfo
{
#region variables
readonly bool _disabled;
#endregion
#region constructor
public DnsResourceRecordInfo()
{ }
public DnsResourceRecordInfo(bool disabled)
{
_disabled = disabled;
}
public DnsResourceRecordInfo(BinaryReader bR)
{
switch (bR.ReadByte()) //version
{
case 1:
_disabled = bR.ReadBoolean();
break;
default:
throw new NotSupportedException("Zone.DnsResourceRecordInfo format version not supported.");
}
}
#endregion
#region public
public void WriteTo(BinaryWriter bW)
{
bW.Write((byte)1); //version
bW.Write(_disabled);
}
#endregion
#region properties
public bool Disabled
{ get { return _disabled; } }
#endregion
}
class DnsNXRecord : DnsResourceRecordData
{
#region variables
DnsResourceRecord _authority;
#endregion
#region constructor
public DnsNXRecord(DnsResourceRecord authority)
{
_authority = authority;
}
#endregion
#region protected
protected override void Parse(Stream s)
{ }
protected override void WriteRecordData(Stream s, List<DnsDomainOffset> domainEntries)
{ }
#endregion
#region public
public override bool Equals(object obj)
{
if (ReferenceEquals(null, obj))
return false;
if (ReferenceEquals(this, obj))
return true;
DnsNXRecord other = obj as DnsNXRecord;
if (other == null)
return false;
return _authority.Equals(other._authority);
}
public override int GetHashCode()
{
return _authority.GetHashCode();
}
public override string ToString()
{
return _authority.RDATA.ToString();
}
#endregion
#region properties
public DnsResourceRecord Authority
{ get { return _authority; } }
#endregion
}
class DnsEmptyRecord : DnsResourceRecordData
{
#region variables
DnsResourceRecord _authority;
#endregion
#region constructor
public DnsEmptyRecord(DnsResourceRecord authority)
{
_authority = authority;
}
#endregion
#region protected
protected override void Parse(Stream s)
{ }
protected override void WriteRecordData(Stream s, List<DnsDomainOffset> domainEntries)
{ }
#endregion
#region public
public override bool Equals(object obj)
{
if (ReferenceEquals(null, obj))
return false;
if (ReferenceEquals(this, obj))
return true;
DnsEmptyRecord other = obj as DnsEmptyRecord;
if (other == null)
return false;
return _authority.Equals(other._authority);
}
public override int GetHashCode()
{
return _authority.GetHashCode();
}
public override string ToString()
{
return _authority.RDATA.ToString();
}
#endregion
#region properties
public DnsResourceRecord Authority
{ get { return _authority; } }
#endregion
}
class DnsANYRecord : DnsResourceRecordData
{
#region variables
DnsResourceRecord[] _records;
#endregion
#region constructor
public DnsANYRecord(DnsResourceRecord[] records)
{
_records = records;
}
#endregion
#region protected
protected override void Parse(Stream s)
{ }
protected override void WriteRecordData(Stream s, List<DnsDomainOffset> domainEntries)
{ }
public override string ToString()
{
return "[MultipleRecords: " + _records.Length + "]";
}
#endregion
#region public
public override bool Equals(object obj)
{
if (ReferenceEquals(null, obj))
return false;
if (ReferenceEquals(this, obj))
return true;
DnsANYRecord other = obj as DnsANYRecord;
if (other == null)
return false;
return true;
}
public override int GetHashCode()
{
return 0;
}
#endregion
#region properties
public DnsResourceRecord[] Records
{ get { return _records; } }
#endregion
}
}
}