private unsafe HashSet <string> BuildCache()
{
var size = 1024;
lock (sync)
{
while (true)
{
var buffer = resizeableBuffer.Get(ref size, false);
fixed(byte *b = buffer)
{
var result = IPHlpApi.GetAdaptersAddresses(
AddressFamily.AF_UNSPEC,
GetAdaptersAddressesFlags.GAA_FLAG_INCLUDE_WINS_INFO |
GetAdaptersAddressesFlags.GAA_FLAG_INCLUDE_GATEWAYS |
GetAdaptersAddressesFlags.GAA_FLAG_INCLUDE_ALL_INTERFACES,
IntPtr.Zero,
b,
ref size);
if (result == (int)ErrorCodes.ERROR_BUFFER_OVERFLOW)
{
continue;
}
if (result == (int)ErrorCodes.ERROR_NO_DATA)
{
return(new HashSet <string>(StringComparer.OrdinalIgnoreCase));
}
if (result != (int)ErrorCodes.ERROR_SUCCESS)
{
Win32ExceptionUtility.Throw(result);
}
var upInterfaces = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
for (var ptr = (IP_ADAPTER_ADDRESSES *)b; ptr != null; ptr = ptr->Next)
{
UnsafeHelper.CheckBounds(b, size, ptr, sizeof(IP_ADAPTER_ADDRESSES));
if (ptr->OperStatus == OperationalStatus.Up && ptr->IfType != NetworkInterfaceType.Loopback)
{
upInterfaces.Add(GetAdapterIdentity(new string(ptr->Description)));
}
}
return(upInterfaces);
}
}
}
}
private static unsafe void VisitProcesses(byte *ptr, byte[] buffer, SystemProcInfoVisitor visit)
{
while (true)
{
UnsafeHelper.CheckBounds(ptr, buffer.Length, ptr, sizeof(SystemProcessInformation));
var processInfo = (SystemProcessInformation *)ptr;
// don't visit processes which maybe suspended zombies
// (which may appear in NtQuerySystemInformation output)
// to avoid survival of zombie processes due to opened handles
// TODO rewrite this comment
if (!IsZombie(processInfo))
{
visit(processInfo);
}
if (processInfo->NextEntryOffset == 0)
{
return;
}
ptr += processInfo->NextEntryOffset;
}
}