/// <summary>
/// Get the IP and MAC addresses of all known devices on the LAN
/// </summary>
/// <remarks>
/// 1) This table is not updated often - it can take some human-scale time
/// to notice that a device has dropped off the network, or a new device
/// has connected.
/// 2) This discards non-local devices if they are found - these are multicast
/// and can be discarded by IP address range.
/// </remarks>
/// <returns></returns>
private static Dictionary <IPAddress, PhysicalAddress> GetAllDevicesOnLan()
{
var all = new Dictionary <IPAddress, PhysicalAddress> {
{ GetIpAddress(), GetMacAddress() }
};
// Add this PC to the list...
var spaceForNetTable = 0;
// Get the space needed
// We do that by requesting the table, but not giving any space at all.
// The return value will tell us how much we actually need.
GetIpNetTable(IntPtr.Zero, ref spaceForNetTable, false);
// Allocate the space
// We use a try-finally block to ensure release.
var rawTable = IntPtr.Zero;
try
{
rawTable = Marshal.AllocCoTaskMem(spaceForNetTable);
// Get the actual data
var errorCode = GetIpNetTable(rawTable, ref spaceForNetTable, false);
if (errorCode != 0)
{
// Failed for some reason - can do no more here.
throw new Exception($"Unable to retrieve network table. Error code {errorCode}");
}
// Get the rows count
var rowsCount = Marshal.ReadInt32(rawTable);
var currentBuffer = new IntPtr(rawTable.ToInt64() + Marshal.SizeOf(typeof(int)));
// Convert the raw table to individual entries
var rows = new MibIpnetrow[rowsCount];
for (var index = 0; index < rowsCount; index++)
{
rows[index] = (MibIpnetrow)Marshal.PtrToStructure(new IntPtr(currentBuffer.ToInt64() +
index *
Marshal.SizeOf(typeof(MibIpnetrow))
),
typeof(MibIpnetrow));
}
// Define the dummy entries list (we can discard these)
var virtualMac = new PhysicalAddress(new byte[] { 0, 0, 0, 0, 0, 0 });
var broadcastMac = new PhysicalAddress(new byte[] { 255, 255, 255, 255, 255, 255 });
foreach (var row in rows)
{
var ip = new IPAddress(BitConverter.GetBytes(row.dwAddr));
byte[] rawMac = { row.mac0, row.mac1, row.mac2, row.mac3, row.mac4, row.mac5 };
var pa = new PhysicalAddress(rawMac);
if (!pa.Equals(virtualMac) && !pa.Equals(broadcastMac) && !IsMulticast(ip))
{
//Console.WriteLine("IP: {0}\t\tMAC: {1}", ip.ToString(), pa.ToString());
if (!all.ContainsKey(ip))
{
all.Add(ip, pa);
}
}
}
}
finally
{
// Release the memory.
Marshal.FreeCoTaskMem(rawTable);
}
return(all);
}
public static List<string> GetRouterMac(string ipRequest = "192.168.1.1")
{
// The number of bytes needed.
int bytesNeeded = 0;
// The result from the API call.
int result = GetIpNetTable(IntPtr.Zero, ref bytesNeeded, false);
// Call the function, expecting an insufficient buffer.
if (result != ErrorInsufficientBuffer)
{
// Throw an exception.
throw new Win32Exception(result);
}
// Allocate the memory, do it in a try/finally block, to ensure
// that it is released.
IntPtr buffer = IntPtr.Zero;
// Try/finally.
try
{
// Allocate the memory.
buffer = Marshal.AllocCoTaskMem(bytesNeeded);
// Make the call again. If it did not succeed, then
// raise an error.
result = GetIpNetTable(buffer, ref bytesNeeded, false);
// If the result is not 0 (no error), then throw an exception.
if (result != 0)
{
// Throw an exception.
throw new Win32Exception(result);
}
// Now we have the buffer, we have to marshal it. We can read
// the first 4 bytes to get the length of the buffer.
int entries = Marshal.ReadInt32(buffer);
// Increment the memory pointer by the size of the int.
IntPtr currentBuffer = new IntPtr(buffer.ToInt64() +
Marshal.SizeOf(typeof(int)));
// Allocate an array of entries.
MibIpnetrow[] table = new MibIpnetrow[entries];
// Cycle through the entries.
for (int index = 0; index < entries; index++)
{
// Call PtrToStructure, getting the structure information.
table[index] = (MibIpnetrow)Marshal.PtrToStructure(new
IntPtr(currentBuffer.ToInt64() + (index *
Marshal.SizeOf(typeof(MibIpnetrow)))), typeof(MibIpnetrow));
}
List<string> list = new List<string>();
for (int index = 0; index < entries; index++)
{
MibIpnetrow row = table[index];
IPAddress ip = new IPAddress(BitConverter.GetBytes(row.dwAddr));
StringBuilder sbMac = new StringBuilder();
sbMac.Append(row.mac0.ToString("X2") + '-');
sbMac.Append(row.mac1.ToString("X2") + '-');
sbMac.Append(row.mac2.ToString("X2") + '-');
sbMac.Append(row.mac3.ToString("X2") + '-');
sbMac.Append(row.mac4.ToString("X2") + '-');
sbMac.Append(row.mac5.ToString("X2"));
if (ip.ToString() == ipRequest)
{
list.Add(sbMac.ToString());
}
}
//if (list.Count == 0)
//{
// throw new Exception("不存在的IP地址: " + ipRequest);
//}
return list;
}
finally
{
// Release the memory.
FreeMibTable(buffer);
}
}
