我想找出我们局域网中哪些设备在线,哪些设备离线。
我见过许多程序展示了局域网的IP地址和MAC地址等图形化网络概述。
我想知道是否可以从C#/.NET
中提取这些(ARP?)信息,以及如何提取?
我想找出我们局域网中哪些设备在线,哪些设备离线。
我见过许多程序展示了局域网的IP地址和MAC地址等图形化网络概述。
我想知道是否可以从C#/.NET
中提取这些(ARP?)信息,以及如何提取?
using System;
using System.Net;
using System.Net.NetworkInformation;
using System.Text;
namespace Examples.System.Net.NetworkInformation.PingTest
{
public class PingExample
{
// args[0] can be an IPaddress or host name.
public static void Main (string[] args)
{
Ping pingSender = new Ping ();
PingOptions options = new PingOptions ();
// Use the default Ttl value which is 128,
// but change the fragmentation behavior.
options.DontFragment = true;
// Create a buffer of 32 bytes of data to be transmitted.
string data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
byte[] buffer = Encoding.ASCII.GetBytes (data);
int timeout = 120;
PingReply reply = pingSender.Send (args[0], timeout, buffer, options);
if (reply.Status == IPStatus.Success)
{
Console.WriteLine ("Address: {0}", reply.Address.ToString ());
Console.WriteLine ("RoundTrip time: {0}", reply.RoundtripTime);
Console.WriteLine ("Time to live: {0}", reply.Options.Ttl);
Console.WriteLine ("Don't fragment: {0}", reply.Options.DontFragment);
Console.WriteLine ("Buffer size: {0}", reply.Buffer.Length);
}
}
}
}
using System;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.Net;
namespace GetIpNetTable
{
class Program
{
// The max number of physical addresses.
const int MAXLEN_PHYSADDR = 8;
// Define the MIB_IPNETROW structure.
[StructLayout(LayoutKind.Sequential)]
struct MIB_IPNETROW
{
[MarshalAs(UnmanagedType.U4)]
public int dwIndex;
[MarshalAs(UnmanagedType.U4)]
public int dwPhysAddrLen;
[MarshalAs(UnmanagedType.U1)]
public byte mac0;
[MarshalAs(UnmanagedType.U1)]
public byte mac1;
[MarshalAs(UnmanagedType.U1)]
public byte mac2;
[MarshalAs(UnmanagedType.U1)]
public byte mac3;
[MarshalAs(UnmanagedType.U1)]
public byte mac4;
[MarshalAs(UnmanagedType.U1)]
public byte mac5;
[MarshalAs(UnmanagedType.U1)]
public byte mac6;
[MarshalAs(UnmanagedType.U1)]
public byte mac7;
[MarshalAs(UnmanagedType.U4)]
public int dwAddr;
[MarshalAs(UnmanagedType.U4)]
public int dwType;
}
// Declare the GetIpNetTable function.
[DllImport("IpHlpApi.dll")]
[return: MarshalAs(UnmanagedType.U4)]
static extern int GetIpNetTable(
IntPtr pIpNetTable,
[MarshalAs(UnmanagedType.U4)]
ref int pdwSize,
bool bOrder);
[DllImport("IpHlpApi.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern int FreeMibTable(IntPtr plpNetTable);
// The insufficient buffer error.
const int ERROR_INSUFFICIENT_BUFFER = 122;
static void Main(string[] args)
{
// 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 != ERROR_INSUFFICIENT_BUFFER)
{
// 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.
MIB_IPNETROW[] table = new MIB_IPNETROW[entries];
// Cycle through the entries.
for (int index = 0; index < entries; index++)
{
// Call PtrToStructure, getting the structure information.
table[index] = (MIB_IPNETROW) Marshal.PtrToStructure(new
IntPtr(currentBuffer.ToInt64() + (index *
Marshal.SizeOf(typeof(MIB_IPNETROW)))), typeof(MIB_IPNETROW));
}
for (int index = 0; index < entries; index++)
{
MIB_IPNETROW row = table[index];
IPAddress ip=new IPAddress(BitConverter.GetBytes(row.dwAddr));
Console.Write("IP:"+ip.ToString()+"\t\tMAC:");
Console.Write( row.mac0.ToString("X2") + '-');
Console.Write( row.mac1.ToString("X2") + '-');
Console.Write( row.mac2.ToString("X2") + '-');
Console.Write( row.mac3.ToString("X2") + '-');
Console.Write( row.mac4.ToString("X2") + '-');
Console.WriteLine( row.mac5.ToString("X2"));
}
}
finally
{
// Release the memory.
FreeMibTable(buffer);
}
}
}
}
FreeMibTable
- 我不知道我们在谈论Vista及以后的版本。 :) - Jesse Chisholm它能够在Windows和Linux上将MAC地址分配给IP地址。在Windows上,它使用IpHlpApi.SendARP api。在Linux上,它从/proc/net/arp读取arp表。如果找不到IP地址,它会尝试ping它(强制操作系统进行arp请求),然后再次查看arp缓存。这样做无需任何依赖项(托管或非托管),也无需启动进程并解析其stdout等。
Windows版本不是异步的,因为底层API不是异步的。由于Linux版本是真正的异步(arp缓存的异步文件io + corefx异步ping api),所以我决定提供异步api,并在Windows上返回完成的Task。
这很容易使用。一个现实世界的用例示例在这里可用。
internal static class ArpLookupService
{
/// <summary>
/// Call ApHlpApi.SendARP to lookup the mac address on windows-based systems.
/// </summary>
/// <exception cref="Win32Exception">If IpHlpApi.SendARP returns non-zero.</exception>
public static PhysicalAddress Lookup(IPAddress ip)
{
if (ip == null)
throw new ArgumentNullException(nameof(ip));
int destIp = BitConverter.ToInt32(ip.GetAddressBytes(), 0);
var addr = new byte[6];
var len = addr.Length;
var res = NativeMethods.SendARP(destIp, 0, addr, ref len);
if (res == 0)
return new PhysicalAddress(addr);
throw new Win32Exception(res);
}
private static class NativeMethods
{
private const string IphlpApi = "iphlpapi.dll";
[DllImport(IphlpApi, ExactSpelling = true)]
[SecurityCritical]
internal static extern int SendARP(int destinationIp, int sourceIp, byte[] macAddress, ref int physicalAddrLength);
}
}