[DllImport("iphlpapi.dll", SetLastError=true)]
static extern uint GetExtendedTcpTable(IntPtr pTcpTable, ref int dwOutBufLen, bool sort, int ipVersion, TCP_TABLE_CLASS tblClass,uint reserved = 0);
<DllImport("iphlpapi.dll", SetLastError:=True)> _
Public Shared Function GetExtendedTcpTable(ByVal pTcpTable As IntPtr, ByRef dwOutBufLen As Integer, ByVal sort As Boolean, ByVal ipVersion As Integer, ByVal tblClass As TCP_TABLE_CLASS, ByVal reserved As Integer) As UInteger
End Function
When you do not need the PID information look at: IPGlobalProperties.GetActiveTcpListeners Method from the System.Net.NetworkInformation namespace
Generic methods for IPv4 and IPv6. Using MIB_TCPROW_OWNER_PID, MIB_TCPTABLE_OWNER_PID, MIB_TCP6ROW_OWNER_PID, MIB_TCP6TABLE_OWNER_PID and TCP_TABLE_CLASS
public const int AF_INET = 2; // IP_v4 = System.Net.Sockets.AddressFamily.InterNetwork
public const int AF_INET6 = 23; // IP_v6 = System.Net.Sockets.AddressFamily.InterNetworkV6
public static List<MIB_TCPROW_OWNER_PID> GetAllTCPConnections()
{
return GetTCPConnections<MIB_TCPROW_OWNER_PID, MIB_TCPTABLE_OWNER_PID>(AF_INET);
}
public static List<MIB_TCP6ROW_OWNER_PID> GetAllTCPv6Connections()
{
return GetTCPConnections<MIB_TCP6ROW_OWNER_PID, MIB_TCP6TABLE_OWNER_PID>(AF_INET6);
}
private static List<IPR> GetTCPConnections<IPR, IPT>(int ipVersion)//IPR = Row Type, IPT = Table Type
{
IPR[] tableRows;
int buffSize = 0;
var dwNumEntriesField = typeof(IPT).GetField("dwNumEntries");
// how much memory do we need?
uint ret = GetExtendedTcpTable(IntPtr.Zero, ref buffSize, true, ipVersion, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL);
IntPtr tcpTablePtr = Marshal.AllocHGlobal(buffSize);
try
{
ret = GetExtendedTcpTable(tcpTablePtr, ref buffSize, true, ipVersion, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL);
if (ret != 0)
return new List<IPR>();
// get the number of entries in the table
IPT table = (IPT)Marshal.PtrToStructure(tcpTablePtr, typeof(IPT));
int rowStructSize = Marshal.SizeOf(typeof(IPR));
uint numEntries = (uint)dwNumEntriesField.GetValue(table);
// buffer we will be returning
tableRows = new IPR[numEntries];
IntPtr rowPtr = (IntPtr)((long)tcpTablePtr + 4);
for (int i = 0; i < numEntries; i++)
{
IPR tcpRow = (IPR)Marshal.PtrToStructure(rowPtr, typeof(IPR));
tableRows[i] = tcpRow;
rowPtr = (IntPtr)((long)rowPtr + rowStructSize); // next entry
}
}
finally
{
// Free the Memory
Marshal.FreeHGlobal(tcpTablePtr);
}
return tableRows != null ? tableRows.ToList() : new List<IPR>();
}
Previous sample
public MIB_TCPROW_OWNER_PID[] GetAllTcpConnections()
{
MIB_TCPROW_OWNER_PID[] tTable;
int AF_INET = 2; // IP_v4
int buffSize = 0;
// how much memory do we need?
uint ret = GetExtendedTcpTable(IntPtr.Zero, ref buffSize, true, AF_INET, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL);
IntPtr buffTable = Marshal.AllocHGlobal(buffSize);
try
{
ret = GetExtendedTcpTable(buffTable, ref buffSize, true, AF_INET, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL);
if (ret != 0)
{
return null;
}
// get the number of entries in the table
MIB_TCPTABLE_OWNER_PID tab = (MIB_TCPTABLE_OWNER_PID)Marshal.PtrToStructure(buffTable, typeof(MIB_TCPTABLE_OWNER_PID));
IntPtr rowPtr = (IntPtr)((long)buffTable + Marshal.SizeOf(tab.dwNumEntries));
tTable = new MIB_TCPROW_OWNER_PID[tab.dwNumEntries];
for (int i = 0; i < tab.dwNumEntries; i++)
{
MIB_TCPROW_OWNER_PID tcpRow = (MIB_TCPROW_OWNER_PID)Marshal.PtrToStructure(rowPtr, typeof(MIB_TCPROW_OWNER_PID));
tTable[i] = tcpRow;
rowPtr = (IntPtr)((long)rowPtr + Marshal.SizeOf(tcpRow)); // next entry
}
}
finally
{
// Free the Memory
Marshal.FreeHGlobal(buffTable);
}
return tTable;
}