Files
DnsServer/DnsServerCore/Dns/Trees/AuthZoneTree.cs
2022-01-16 19:58:42 +05:30

568 lines
20 KiB
C#

/*
Technitium DNS Server
Copyright (C) 2022 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 DnsServerCore.Dns.Zones;
using System;
using System.Collections.Generic;
using System.Threading;
using TechnitiumLibrary.Net.Dns.ResourceRecords;
namespace DnsServerCore.Dns.Trees
{
class AuthZoneTree : ZoneTree<AuthZoneNode, SubDomainZone, ApexZone>
{
#region private
private static Node GetPreviousSubDomainZoneNode(byte[] key, Node current, int baseDepth)
{
int k = key[current.Depth];
while ((current is not null) && (current.Depth >= baseDepth))
{
Node[] children = current.Children;
if (children is not null)
{
//find previous child node
Node child = null;
for (int i = k; i > -1; i--)
{
child = Volatile.Read(ref children[i]);
if (child is not null)
{
NodeValue value = child.Value;
if (value is not null)
{
AuthZoneNode zoneNode = value.Value;
if (zoneNode is not null)
{
if (zoneNode.ParentSideZone is not null)
{
//is sub domain zone
return child; //child has value so return it
}
else
{
//is apex zone
//skip to next child to avoid listing this auth zone's sub domains
child = null; //set null to avoid child being set as current after the loop
continue;
}
}
}
if (child.Children is not null)
break;
}
}
if (child is not null)
{
//make found child as current
k = children.Length - 1;
current = child;
continue; //start over
}
}
//no child node found; check for current node value
{
NodeValue value = current.Value;
if (value is not null)
{
AuthZoneNode zoneNode = value.Value;
if (zoneNode is not null)
{
ApexZone apexZone = zoneNode.ApexZone;
if (apexZone is not null)
{
//current contains apex zone; return it
return current;
}
}
}
}
//no child nodes available; move up to parent node
k = current.K - 1;
current = current.Parent;
}
return null;
}
private static Node GetNextSubDomainZoneNode(Node current, int baseDepth)
{
int k = 0;
while ((current is not null) && (current.Depth >= baseDepth))
{
if (current.Depth > baseDepth)
{
NodeValue value = current.Value;
if (value is not null)
{
AuthZoneNode zoneNode = value.Value;
if (zoneNode is not null)
{
ApexZone apexZone = zoneNode.ApexZone;
if (apexZone is not null)
{
//current contains apex for a sub zone; move up to parent node
k = current.K + 1;
current = current.Parent;
continue;
}
}
}
}
Node[] children = current.Children;
if (children is not null)
{
//find next child node
Node child = null;
for (int i = k; i < children.Length; i++)
{
child = Volatile.Read(ref children[i]);
if (child is not null)
{
NodeValue value = child.Value;
if (value is not null)
{
AuthZoneNode zoneNode = value.Value;
if (zoneNode is not null)
{
if (zoneNode.ParentSideZone is not null)
{
//is sub domain zone
return child; //child has value so return it
}
else
{
//is apex zone
//skip to next child to avoid listing this auth zone's sub domains
child = null; //set null to avoid child being set as current after the loop
continue;
}
}
}
if (child.Children is not null)
break;
}
}
if (child is not null)
{
//make found child as current
k = 0;
current = child;
continue; //start over
}
}
//no child nodes available; move up to parent node
k = current.K + 1;
current = current.Parent;
}
return null;
}
private static bool SubDomainExists(byte[] key, Node closestNode)
{
if (!closestNode.HasChildren)
return false;
Node nextSubDomain = GetNextSubDomainZoneNode(closestNode, closestNode.Depth);
if (nextSubDomain is null)
return false;
NodeValue value = nextSubDomain.Value;
if (value is null)
return false;
return IsKeySubDomain(key, value.Key);
}
#endregion
#region protected
protected override void GetClosestValuesForZone(AuthZoneNode zoneValue, ref SubDomainZone closestSubDomain, ref SubDomainZone closestDelegation, ref ApexZone closestAuthority)
{
ApexZone apexZone = zoneValue.ApexZone;
if (apexZone is not null)
{
//hosted primary/secondary/stub/forwarder zone found
closestSubDomain = null;
closestDelegation = zoneValue.ParentSideZone;
closestAuthority = apexZone;
}
else
{
//hosted sub domain
SubDomainZone subDomainZone = zoneValue.ParentSideZone;
if ((closestDelegation is null) && subDomainZone.ContainsNameServerRecords())
closestDelegation = subDomainZone; //delegated sub domain found
else
closestSubDomain = subDomainZone;
}
}
#endregion
#region public
public bool TryAdd(ApexZone zone)
{
AuthZoneNode zoneNode = GetOrAdd(zone.Name, delegate (string key)
{
return new AuthZoneNode(null, zone);
});
if (ReferenceEquals(zoneNode.ApexZone, zone))
return true; //added successfully
return zoneNode.TryAdd(zone);
}
public bool TryGet(string zoneName, string domain, out AuthZone authZone)
{
if (TryGet(domain, out AuthZoneNode zoneNode))
{
if (zoneName.Equals(domain, StringComparison.OrdinalIgnoreCase))
{
if (zoneNode.ApexZone is not null)
{
authZone = zoneNode.ApexZone;
return true;
}
}
else
{
if (zoneNode.ParentSideZone is not null)
{
authZone = zoneNode.ParentSideZone;
return true;
}
}
}
authZone = null;
return false;
}
public AuthZone GetOrAddSubDomainZone(string zoneName, string domain, Func<SubDomainZone> valueFactory)
{
bool isApex = zoneName.Equals(domain, StringComparison.OrdinalIgnoreCase);
AuthZoneNode zoneNode = GetOrAdd(domain, delegate (string key)
{
if (isApex)
throw new DnsServerException("Zone was not found for domain: " + key);
return new AuthZoneNode(valueFactory(), null);
});
if (isApex)
{
if (zoneNode.ApexZone is null)
throw new DnsServerException("Zone was not found: " + zoneName);
return zoneNode.ApexZone;
}
else
{
return zoneNode.GetOrAddParentSideZone(valueFactory);
}
}
public bool TryRemove(string domain, out ApexZone value)
{
if (!TryGet(domain, out AuthZoneNode zoneNode, out Node closestNode) || (zoneNode.ApexZone is null))
{
value = null;
return false;
}
value = zoneNode.ApexZone;
if (zoneNode.ParentSideZone is null)
{
//remove complete zone node
if (!base.TryRemove(domain, out AuthZoneNode _))
{
value = null;
return false;
}
}
else
{
//parent side sub domain exists; remove only apex zone from zone node
if (!zoneNode.TryRemove(out ApexZone _))
{
value = null;
return false;
}
}
//remove all sub domains under current zone
Node current = closestNode;
do
{
current = GetNextSubDomainZoneNode(current, closestNode.Depth);
if (current is null)
break;
NodeValue v = current.Value;
if (v is not null)
{
AuthZoneNode z = v.Value;
if (z is not null)
{
if (z.ApexZone is null)
{
//no apex zone at this node; remove complete zone node
current.RemoveNodeValue(v.Key, out _); //remove node value
current.CleanThisBranch();
}
else
{
//apex node exists; remove parent size sub domain
z.TryRemove(out SubDomainZone _);
}
}
}
}
while (true);
closestNode.CleanThisBranch();
return true;
}
public bool TryRemove(string domain, out SubDomainZone value)
{
if (!TryGet(domain, out AuthZoneNode zoneNode, out Node closestNode) || (zoneNode.ParentSideZone is null))
{
value = null;
return false;
}
value = zoneNode.ParentSideZone;
if (zoneNode.ApexZone is null)
{
//remove complete zone node
if (!base.TryRemove(domain, out AuthZoneNode _))
{
value = null;
return false;
}
}
else
{
//apex zone exists; remove only parent side sub domain from zone node
if (!zoneNode.TryRemove(out SubDomainZone _))
{
value = null;
return false;
}
}
closestNode.CleanThisBranch();
return true;
}
public override bool TryRemove(string key, out AuthZoneNode value)
{
throw new InvalidOperationException();
}
public List<AuthZone> GetZoneWithSubDomainZones(string zoneName)
{
if (zoneName is null)
throw new ArgumentNullException(nameof(zoneName));
List<AuthZone> zones = new List<AuthZone>();
byte[] bKey = ConvertToByteKey(zoneName);
NodeValue nodeValue = _root.FindNodeValue(bKey, out Node closestNode);
if (nodeValue is not null)
{
AuthZoneNode zoneNode = nodeValue.Value;
if (zoneNode is not null)
{
ApexZone apexZone = zoneNode.ApexZone;
if (apexZone is not null)
{
zones.Add(apexZone);
Node current = closestNode;
do
{
current = GetNextSubDomainZoneNode(current, closestNode.Depth);
if (current is null)
break;
NodeValue value = current.Value;
if (value is not null)
{
zoneNode = value.Value;
if (zoneNode is not null)
zones.Add(zoneNode.ParentSideZone);
}
}
while (true);
}
}
}
return zones;
}
public AuthZone FindZone(string domain, out SubDomainZone closest, out SubDomainZone delegation, out ApexZone authority, out bool hasSubDomains)
{
if (domain is null)
throw new ArgumentNullException(nameof(domain));
byte[] key = ConvertToByteKey(domain);
AuthZoneNode zoneNode = FindZone(key, out Node closestNode, out _, out SubDomainZone closestSubDomain, out SubDomainZone closestDelegation, out ApexZone closestAuthority);
if (zoneNode is null)
{
//zone not found
closest = closestSubDomain;
delegation = closestDelegation;
authority = closestAuthority;
if (authority is null)
{
//no authority so no subdomains
hasSubDomains = false;
}
else
{
//check if current node has sub domains
NodeValue value = closestNode.Value;
if (value is null)
hasSubDomains = SubDomainExists(key, closestNode);
else
hasSubDomains = IsKeySubDomain(key, value.Key);
}
return null;
}
else
{
//zone found
AuthZone zone;
ApexZone apexZone = zoneNode.ApexZone;
if (apexZone is not null)
{
zone = apexZone;
closest = null;
delegation = zoneNode.ParentSideZone;
authority = apexZone;
}
else
{
SubDomainZone subDomainZone = zoneNode.ParentSideZone;
zone = subDomainZone;
closest = closestSubDomain;
if (closestDelegation is not null)
delegation = closestDelegation;
else if (subDomainZone.ContainsNameServerRecords())
delegation = subDomainZone;
else
delegation = null;
authority = closestAuthority;
}
hasSubDomains = false; //since zone is found, it does not matter if subdomain exists or not
return zone;
}
}
public IReadOnlyList<DnsResourceRecord> FindProofOfNonExistenceNxDomain(string domain, DnsResourceRecordType type)
{
if (domain is null)
throw new ArgumentNullException(nameof(domain));
byte[] key = ConvertToByteKey(domain);
AuthZoneNode zoneNode = FindZone(key, out Node closestNode, out Node closestAuthorityNode, out _, out _, out _);
if (zoneNode is not null)
return Array.Empty<DnsResourceRecord>(); //domain exists! cannot prove non existence
//check for value at closest node
NodeValue value = closestNode.Value;
if (value is not null)
{
AuthZoneNode zNode = value.Value;
if (zNode is not null)
{
ApexZone apexZone = zNode.ApexZone;
if ((apexZone is not null) && (type != DnsResourceRecordType.DS))
return apexZone.QueryRecords(DnsResourceRecordType.NSEC, true);
SubDomainZone parentSideZone = zNode.ParentSideZone;
if (parentSideZone is not null)
return parentSideZone.QueryRecords(DnsResourceRecordType.NSEC, true);
}
}
Node previousNode = GetPreviousSubDomainZoneNode(key, closestNode, closestAuthorityNode.Depth);
if (previousNode is not null)
{
NodeValue pValue = previousNode.Value;
if (pValue is not null)
{
AuthZoneNode zNode = pValue.Value;
if (zNode is not null)
{
ApexZone apexZone = zNode.ApexZone;
if ((apexZone is not null) && (type != DnsResourceRecordType.DS))
return apexZone.QueryRecords(DnsResourceRecordType.NSEC, true);
SubDomainZone parentSideZone = zNode.ParentSideZone;
if (parentSideZone is not null)
return parentSideZone.QueryRecords(DnsResourceRecordType.NSEC, true);
}
}
}
return Array.Empty<DnsResourceRecord>();
}
#endregion
}
}