fergalmoran/DnsServer
1
0
Fork 0
mirror of https://github.com/fergalmoran/DnsServer.git synced 2026-01-04 15:55:32 +00:00
Code Issues Packages Projects Releases Wiki Activity

Scope: Added scope name validation. Updated FindInterface() to handle PlatformNotSupportedException. Updated GetOfferAsync() to return existing reserved lease only when the IP address matches. Updated GetExistingLeaseOrOffer() to check for offers first. Updated RemoveLease() to remove matching reserved lease entry only when the IP addresses match.

Browse Source
This commit is contained in:
Shreyas Zare
2022-03-06 15:30:18 +05:30
parent f81880f1a2
commit 5cd9d2e37d
1 changed files with 84 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

114
DnsServerCore/Dhcp/Scope.cs
View File

@@ -96,6 +96,8 @@ namespace DnsServerCore.Dhcp
public Scope(string name, bool enabled, IPAddress startingAddress, IPAddress endingAddress, IPAddress subnetMask)
{
ValidateScopeName(name);
_name = name;
_enabled = enabled;
@@ -308,6 +310,15 @@ namespace DnsServerCore.Dhcp
#region static
public static void ValidateScopeName(string name)
{
foreach (char invalidChar in Path.GetInvalidFileNameChars())
{
if (name.Contains(invalidChar))
throw new DhcpServerException("The scope name contains an invalid character: " + invalidChar);
}
}
public static bool IsAddressInRange(IPAddress address, IPAddress startingAddress, IPAddress endingAddress)
{
uint addressNumber = address.ConvertIpToNumber();
@@ -493,11 +504,19 @@ namespace DnsServerCore.Dhcp
{
//found interface for this scope range
//check if interface has dynamic ipv4 address assigned via dhcp
foreach (IPAddress dhcpServerAddress in ipInterface.DhcpServerAddresses)
try
{
if (dhcpServerAddress.AddressFamily == AddressFamily.InterNetwork)
throw new DhcpServerException("DHCP Server requires static IP address to work correctly but the network interface was found to have a dynamic IP address [" + ip.Address.ToString() + "] assigned by another DHCP server: " + dhcpServerAddress.ToString());
//check if interface has dynamic ipv4 address assigned via dhcp
foreach (IPAddress dhcpServerAddress in ipInterface.DhcpServerAddresses)
{
if (dhcpServerAddress.AddressFamily == AddressFamily.InterNetwork)
throw new DhcpServerException("DHCP Server requires static IP address to work correctly but the network interface was found to have a dynamic IP address [" + ip.Address.ToString() + "] assigned by another DHCP server: " + dhcpServerAddress.ToString());
}
}
catch (PlatformNotSupportedException)
{
//DhcpServerAddresses() not supported on macOs
//ignore the exception
}
_interfaceAddress = ip.Address;
@@ -508,30 +527,38 @@ namespace DnsServerCore.Dhcp
}
}
//check if at least one interface has static ip address
foreach (NetworkInterface nic in NetworkInterface.GetAllNetworkInterfaces())
try
{
if (nic.OperationalStatus != OperationalStatus.Up)
continue;
IPInterfaceProperties ipInterface = nic.GetIPProperties();
foreach (UnicastIPAddressInformation ip in ipInterface.UnicastAddresses)
//check if at least one interface has static ip address
foreach (NetworkInterface nic in NetworkInterface.GetAllNetworkInterfaces())
{
if (ip.Address.AddressFamily == AddressFamily.InterNetwork)
if (nic.OperationalStatus != OperationalStatus.Up)
continue;
IPInterfaceProperties ipInterface = nic.GetIPProperties();
foreach (UnicastIPAddressInformation ip in ipInterface.UnicastAddresses)
{
//check if address is static
if (ipInterface.DhcpServerAddresses.Count < 1)
if (ip.Address.AddressFamily == AddressFamily.InterNetwork)
{
//found static ip address so this scope can be activated
//using ANY ip address for this scope interface since we dont know the relay agent network
_interfaceAddress = IPAddress.Any;
_interfaceIndex = -1;
return true;
//check if address is static
if (ipInterface.DhcpServerAddresses.Count < 1)
{
//found static ip address so this scope can be activated
//using ANY ip address for this scope interface since we dont know the relay agent network
_interfaceAddress = IPAddress.Any;
_interfaceIndex = -1;
return true;
}
}
}
}
}
catch (PlatformNotSupportedException)
{
//DhcpServerAddresses() not supported on macOs
//ignore the exception
}
//server has no static ip address configured
return false;
@@ -676,11 +703,28 @@ namespace DnsServerCore.Dhcp
if (_leases.TryGetValue(request.ClientIdentifier, out Lease existingLease))
{
//lease already exists
if ((existingLease.Type == LeaseType.Reserved) || !IsAddressExcluded(existingLease.Address))
return existingLease; //existing lease is reserved or dynamic allocation is not excluded
if (existingLease.Type == LeaseType.Reserved)
{
Lease existingReservedLease = GetReservedLease(request);
if ((existingReservedLease is not null) && (existingReservedLease.Address == existingLease.Address))
return existingLease; //return existing reserved lease
//remove existing dynamic lease
ReleaseLease(existingLease);
//reserved lease address was changed; proceed to offer new lease
}
else
{
//is dynamic lease
if (IsAddressExcluded(existingLease.Address))
{
//remove existing dynamic lease; proceed to offer new lease
ReleaseLease(existingLease);
}
else
{
//return existing dynamic lease
return existingLease;
}
}
}
Lease reservedLease = GetReservedLease(request);
@@ -772,12 +816,13 @@ namespace DnsServerCore.Dhcp
internal Lease GetExistingLeaseOrOffer(DhcpMessage request)
{
if (_leases.TryGetValue(request.ClientIdentifier, out Lease existingLease))
return existingLease;
//check for lease offer first since it may have a different IP address to offer
if (_offers.TryGetValue(request.ClientIdentifier, out Lease existingOffer))
return existingOffer;
if (_leases.TryGetValue(request.ClientIdentifier, out Lease existingLease))
return existingLease;
return null;
}
@@ -982,8 +1027,13 @@ namespace DnsServerCore.Dhcp
if (removedLease.Type == LeaseType.Reserved)
{
//remove reserved lease
Lease reservedLease = new Lease(LeaseType.Reserved, null, DhcpMessageHardwareAddressType.Ethernet, removedLease.HardwareAddress, removedLease.Address, null);
_reservedLeases.TryRemove(reservedLease.ClientIdentifier, out _);
ClientIdentifierOption reservedLeasesClientIdentifier = new ClientIdentifierOption((byte)DhcpMessageHardwareAddressType.Ethernet, removedLease.HardwareAddress);
if (_reservedLeases.TryGetValue(reservedLeasesClientIdentifier, out Lease existingReservedLease))
{
//remove reserved lease only if the IP addresses match
if (existingReservedLease.Address.Equals(removedLease.Address))
_reservedLeases.TryRemove(reservedLeasesClientIdentifier, out _);
}
}
return removedLease;
@@ -1355,7 +1405,11 @@ namespace DnsServerCore.Dhcp
public string Name
{
get { return _name; }
set { _name = value; }
set
{
ValidateScopeName(value);
_name = value;
}
}
public bool Enabled