IpHlpApiConnectionsWrapper

This is a performance focused C# wrapper for iphlpapi.dll.

Works on .NET6

This could be done more efficient in newer vesrions but I want to keep it compatible even with old versions of the language.

It was made for the purpose of retrieving all TCP/UDP connections of any type (process/module/basic, ipv6/ipv4) as fast as possible. Speed is a key goal.

Available functions and methods:

1. SetBufferSize(int newSize)

   Sets buffer size. Reallocates internal buffer for storing data between iphlpapi.dll and the wrapper.

2. GetTcpTable(AddressFamily networkType, TcpTableClass tcpTable, bool sortedOrder = false)

   Retrieves information about all tcp connections of any type (process/module/basic) in the specified network layer (ipv4/ipv6)

3. GetUdpTable(AddressFamily networkType, UdpTableClass udpTable, bool sortedOrder = false)

   Retrieves information about all udp connections of any type (process/module/basic) in the specified network layer (ipv4/ipv6)

4. GetIpNetTableRecords(bool sortedOrder = false)

   Retrieves information about all ip addresses in the network and their associated physical addresses

5. GetTcp4Connections(TcpTableClass tcpTable = TcpTableClass.BasicAll, bool sortedOrder = false)

   Retrieves information about all tcp ipv4 connections of any type (process/module/basic)

6. GetProcessTcp4Connections(TcpTableClass tcpTable = TcpTableClass.ProcessAll, bool sortedOrder = false)

   Retrieves information about all tcp ipv4 process connections (all/listener/connections)

7. GetModuleTcp4Connections(TcpTableClass tcpTable = TcpTableClass.ModuleAll, bool sortedOrder = false)

   Retrieves information about all tcp ipv4 module connections (all/listener/connections)

8. GetBasicTcp4Connections(TcpTableClass tcpTable = TcpTableClass.BasicAll, bool sortedOrder = false)

   Retrieves information about all tcp ipv4 basic connections (all/listener/connections)

9. GetTcp6Connections(TcpTableClass tcpTable = TcpTableClass.ProcessAll, bool sortedOrder = false)

   Retrieves information about all tcp ipv6 connections of any type (process/module/basic)

10. GetProcessTcp6Connections(TcpTableClass tcpTable = TcpTableClass.ProcessAll, bool sortedOrder = false)

    Retrieves information about all tcp ipv6 process connections (all/listener/connections)

11. GetModuleTcp6Connections(TcpTableClass tcpTable = TcpTableClass.ModuleAll, bool sortedOrder = false)

    Retrieves information about all tcp ipv6 module connections (all/listener/connections)

12. GetUdp4Connections(UdpTableClass udpTable = UdpTableClass.Basic, bool sortedOrder = false)

    Retrieves information about all udp ipv4 connections of any type (process/module/basic)

13. GetProcessUdp4Connections(UdpTableClass udpTable = UdpTableClass.Process, bool sortedOrder = false)

    Retrieves information about all udp ipv4 process connections

14. GetModuleUdp4Connections(UdpTableClass udpTable = UdpTableClass.Module, bool sortedOrder = false)

    Retrieves information about all udp ipv4 module connections

15. GetBasicUdp4Connections(UdpTableClass udpTable = UdpTableClass.Basic, bool sortedOrder = false)

    Retrieves information about all udp ipv4 basic connections

16. GetUdp6Connections(UdpTableClass udpTable = UdpTableClass.Basic, bool sortedOrder = false)

    Retrieves information about all udp ipv6 connections of any type (basic/module/process)

17. GetProcessUdp6Connections(UdpTableClass udpTable = UdpTableClass.Process, bool sortedOrder = false)

    Retrieves information about all udp ipv6 process connections

18. GetModuleUdp6Connections(UdpTableClass udpTable = UdpTableClass.Module, bool sortedOrder = false)

    Retrieves information about all udp ipv6 module connections

19. GetBasicUdp6Connections(UdpTableClass udpTable = UdpTableClass.Basic, bool sortedOrder = false)

    Retrieves information about all udp ipv6 basic connections

Available static functions:

1. uint GetBestInterfaceIndex(uint address) / GetBestInterfaceIndex(IPAddress address)

   Retrieves best network interface address index to the target ipv4 address

2. NetworkInterface GetBestInterface4(IPAddress address, NetworkInterface[]? interfaces = null)

   Retrieves best network interface to the target ipv4 address

3. uint GetBestInterfaceIndexEx(IPAddress address)

   Retrieves best network interface address index to the target ipv4/ipv6 address

4. NetworkInterface GetBestInterface6(IPAddress address, NetworkInterface[]? interfaces = null)

   Retrieves best network inteface to the target ipv6 address

5. NetworkInterface GetBestInterface(IPAddress address, NetworkInterface[]? interfaces = null)

   Retrieves best network interface to the target ipv4/ipv6 address

6. byte[] SendARP(uint destionationAddress, uint sourceAddress = 0)

   Resolves PhysicalAddress (in byte[]) by sending ARP request to the target or by getting the PhysicalAddress from the ARP entries list

7. PhysicalAddress SendARP(IPAddress destAddress, IPAddress? srcAddress = null)

   Resolves PhysicalAddress by sending ARP request to the target or by getting the PhysicalAddress from the ARP entries list

Examples

Using freshly created wrapper:

using(IpHelpApiWrapper wrapper = new IpHelpApiWrapper())
{
   Tcp4ProcessRecord[] tcp4ProcessRecordList = wrapper.GetProcessTcp4Connections();
   Tcp4ModuleRecord[] tcp4ModuleRecordList = wrapper.GetModuleTcp4Connections();
   Tcp4Record[] tcp4BasicRecordList = wrapper.GetBasicTcp4Connections();
   Udp4ProcessRecord[] udp4ProcessRecordList = wrapper.GetProcessUdp4Connections();
   Udp4ModuleRecord[] udp4ModuleRecordList = wrapper.GetModuleUdp4Connections();
   Udp4Record[] udp4BasicRecordList = wrapper.GetBasicUdp4Connections();
   Tcp6ProcessRecord[] tcp6ProcessRecordList = wrapper.GetProcessTcp6Connections();
   Tcp6ModuleRecord[] tcp6ModuleRecordList = wrapper.GetModuleTcp6Connections();
   Udp6ProcessRecord[] udp6ProcessRecordList = wrapper.GetProcessUdp6Connections();
   Udp6ModuleRecord[] udp6ModuleRecordList = wrapper.GetModuleUdp6Connections();
   PhysicalAddressRecord[] ipNetRecordList = wrapper.GetIpNetTableRecords();

   tcp4ProcessRecordList = wrapper.GetTcpTable(AddressFamily.InterNetwork, TcpTableClass.ProcessConnections).Cast<Tcp4ProcessRecord>().ToArray();
   tcp6ModuleRecordList = wrapper.GetTcpTable(AddressFamily.InterNetworkV6, TcpTableClass.ModuleConnections).Cast<Tcp6ModuleRecord>().ToArray();
}

Using shared wrapper instance:

Tcp4ProcessRecord[] tcp4ProcessRecordList = IpHelpApiWrapper.Shared.GetProcessTcp4Connections();
Tcp4ModuleRecord[] tcp4ModuleRecordList = IpHelpApiWrapper.Shared.GetModuleTcp4Connections();
Tcp4Record[] tcp4BasicRecordList = IpHelpApiWrapper.Shared.GetBasicTcp4Connections();
Udp4ProcessRecord[] udp4ProcessRecordList = IpHelpApiWrapper.Shared.GetProcessUdp4Connections();
Udp4ModuleRecord[] udp4ModuleRecordList = IpHelpApiWrapper.Shared.GetModuleUdp4Connections();
Udp4Record[] udp4BasicRecordList = IpHelpApiWrapper.Shared.GetBasicUdp4Connections();
Tcp6ProcessRecord[] tcp6ProcessRecordList = IpHelpApiWrapper.Shared.GetProcessTcp6Connections();
Tcp6ModuleRecord[] tcp6ModuleRecordList = IpHelpApiWrapper.Shared.GetModuleTcp6Connections();
Udp6ProcessRecord[] udp6ProcessRecordList = IpHelpApiWrapper.Shared.GetProcessUdp6Connections();
Udp6ModuleRecord[] udp6ModuleRecordList = IpHelpApiWrapper.Shared.GetModuleUdp6Connections();
PhysicalAddressRecord[] ipNetRecordList = IpHelpApiWrapper.Shared.GetIpNetTableRecords();

tcp4ProcessRecordList = IpHelpApiWrapper.Shared.GetTcpTable(AddressFamily.InterNetwork, TcpTableClass.ProcessConnections).Cast<Tcp4ProcessRecord>().ToArray();
tcp6ModuleRecordList = IpHelpApiWrapper.Shared.GetTcpTable(AddressFamily.InterNetworkV6, TcpTableClass.ModuleConnections).Cast<Tcp6ModuleRecord>().ToArray();

Using static functions:

//Retrieves main network interface
public static NetworkInterface GetMainNetworkInterface()
{
    return IpHelpApiWrapper.GetBestInterface4(IPAddress.Any);
}

//Retrieves gateway's address
public static PhysicalAddress GetGatewayPhysicalAddress()
{
    IPAddress targetAddress = IpHelpApiWrapper.GetBestInterface4(IPAddress.Any).GetIPProperties().GatewayAddresses.Last().Address;
    PhysicalAddressRecord[] records = IpHelpApiWrapper.Shared.GetIpNetTableRecords(); // List of ip addresses and their physical addresses
    PhysicalAddress? found = Array.Find(records, x => x.IpAddress.Equals(targetAddress) && (x.NetType != IpNetType.Invalid))?.PhysicalAddress;
    if (found == null) throw new AggregateException("Gateway address was not found in the table");
    return found;

Performance recomendations

If you want to get some fixed type of record, you should get it directly (for example GetProcessTcp4Connections(), GetModuleUdp6Connections()) instead of GetTcpTable or GetUdpTable

Using LocalIPAddress or LocalEndPoint property of any record type internally converts LocalAddress, LocalPort, LocalScopeId into an IPAddress or IpEndPoint. This takes some computing power. If you are developing a high performance application which is, for example, have to compare IP address to the processes IP addresses in bulk, you should consider converting the IP address into uint and only then compare it with the processes IP addresses. Same applies to RemoteAddress and RemoteEndPoint