Spanize interop in System.Net.NetworkInformation (#35098)

Faster and safer

Author: jkotas

src/libraries/Common/src/Interop/Windows/IpHlpApi/Interop.NetworkInformation.cs

@@ -424,19 +424,17 @@ internal struct MibTcp6TableOwnerPid
  }
 
  [StructLayout(LayoutKind.Sequential)]
- internal struct MibTcp6RowOwnerPid
+ internal unsafe struct MibTcp6RowOwnerPid
  {
- [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
- internal byte[] localAddr;
+ internal fixed byte localAddr[16];
  internal uint localScopeId;
  internal byte localPort1;
  internal byte localPort2;
  // Ports are only 16 bit values (in network WORD order, 3,4,1,2).
  // There are reports where the high order bytes have garbage in them.
  internal byte ignoreLocalPort3;
  internal byte ignoreLocalPort4;
- [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
- internal byte[] remoteAddr;
+ internal fixed byte remoteAddr[16];
  internal uint remoteScopeId;
  internal byte remotePort1;
  internal byte remotePort2;
@@ -446,6 +444,9 @@ internal struct MibTcp6RowOwnerPid
  internal byte ignoreRemotePort4;
  internal TcpState state;
  internal uint owningPid;
+
+ internal ReadOnlySpan<byte> localAddrAsSpan => MemoryMarshal.CreateSpan(ref localAddr[0], 16);
+ internal ReadOnlySpan<byte> remoteAddrAsSpan => MemoryMarshal.CreateSpan(ref remoteAddr[0], 16);
  }
 
  internal enum TcpTableClass
@@ -493,10 +494,9 @@ internal struct MibUdp6TableOwnerPid
  }
 
  [StructLayout(LayoutKind.Sequential)]
- internal struct MibUdp6RowOwnerPid
+ internal unsafe struct MibUdp6RowOwnerPid
  {
- [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
- internal byte[] localAddr;
+ internal fixed byte localAddr[16];
  internal uint localScopeId;
  internal byte localPort1;
  internal byte localPort2;
@@ -505,6 +505,8 @@ internal struct MibUdp6RowOwnerPid
  internal byte ignoreLocalPort3;
  internal byte ignoreLocalPort4;
  internal uint owningPid;
+
+ internal ReadOnlySpan<byte> localAddrAsSpan => MemoryMarshal.CreateSpan(ref localAddr[0], 16);
  }
 
  internal delegate void StableUnicastIpAddressTableDelegate(IntPtr context, IntPtr table);

src/libraries/System.Net.NetworkInformation/src/System/Net/NetworkInformation/SystemIPGlobalProperties.cs

@@ -106,7 +106,7 @@ public override IPEndPoint[] GetActiveTcpListeners()
 
  ///
  /// Gets the active TCP connections. Uses the native GetTcpTable API.
- private List<SystemTcpConnectionInformation> GetAllTcpConnections()
+ private unsafe List<SystemTcpConnectionInformation> GetAllTcpConnections()
  {
  uint size = 0;
  uint result = 0;
@@ -128,21 +128,20 @@ private List<SystemTcpConnectionInformation> GetAllTcpConnections()
 
  if (result == Interop.IpHlpApi.ERROR_SUCCESS)
  {
+ var span = new ReadOnlySpan<byte>((byte*)buffer, (int)size);
+
  // The table info just gives us the number of rows.
- Interop.IpHlpApi.MibTcpTable tcpTableInfo = Marshal.PtrToStructure<Interop.IpHlpApi.MibTcpTable>(buffer);
+ ref readonly Interop.IpHlpApi.MibTcpTable tcpTableInfo = ref MemoryMarshal.AsRef<Interop.IpHlpApi.MibTcpTable>(span);
 
  if (tcpTableInfo.numberOfEntries > 0)
  {
  // Skip over the tableinfo to get the inline rows.
- IntPtr newPtr = (IntPtr)((long)buffer + Marshal.SizeOf(tcpTableInfo.numberOfEntries));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibTcpTable));
 
  for (int i = 0; i < tcpTableInfo.numberOfEntries; i++)
  {
- Interop.IpHlpApi.MibTcpRow tcpRow = Marshal.PtrToStructure<Interop.IpHlpApi.MibTcpRow>(newPtr);
- tcpConnections.Add(new SystemTcpConnectionInformation(tcpRow));
-
- // Increment the pointer to the next row.
- newPtr = (IntPtr)((long)newPtr + Marshal.SizeOf(tcpRow));
+ tcpConnections.Add(new SystemTcpConnectionInformation(in MemoryMarshal.AsRef<Interop.IpHlpApi.MibTcpRow>(span)));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibTcpRow));
  }
  }
  }
@@ -179,21 +178,22 @@ private List<SystemTcpConnectionInformation> GetAllTcpConnections()
  Interop.IpHlpApi.TcpTableClass.TcpTableOwnerPidAll, 0);
  if (result == Interop.IpHlpApi.ERROR_SUCCESS)
  {
+ var span = new ReadOnlySpan<byte>((byte*)buffer, (int)size);
+
  // The table info just gives us the number of rows.
- Interop.IpHlpApi.MibTcp6TableOwnerPid tcpTable6OwnerPid = Marshal.PtrToStructure<Interop.IpHlpApi.MibTcp6TableOwnerPid>(buffer);
+ ref readonly Interop.IpHlpApi.MibTcp6TableOwnerPid tcpTable6OwnerPid = ref MemoryMarshal.AsRef<Interop.IpHlpApi.MibTcp6TableOwnerPid>(span);
 
  if (tcpTable6OwnerPid.numberOfEntries > 0)
  {
  // Skip over the tableinfo to get the inline rows.
- IntPtr newPtr = (IntPtr)((long)buffer + Marshal.SizeOf(tcpTable6OwnerPid.numberOfEntries));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibTcp6TableOwnerPid));
 
  for (int i = 0; i < tcpTable6OwnerPid.numberOfEntries; i++)
  {
- Interop.IpHlpApi.MibTcp6RowOwnerPid tcp6RowOwnerPid = Marshal.PtrToStructure<Interop.IpHlpApi.MibTcp6RowOwnerPid>(newPtr);
- tcpConnections.Add(new SystemTcpConnectionInformation(tcp6RowOwnerPid));
+ tcpConnections.Add(new SystemTcpConnectionInformation(in MemoryMarshal.AsRef<Interop.IpHlpApi.MibTcp6RowOwnerPid>(span)));
 
  // We increment the pointer to the next row.
- newPtr = (IntPtr)((long)newPtr + Marshal.SizeOf(tcp6RowOwnerPid));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibTcp6RowOwnerPid));
  }
  }
  }
@@ -215,7 +215,7 @@ private List<SystemTcpConnectionInformation> GetAllTcpConnections()
  }
 
  /// Gets the active UDP listeners. Uses the native GetUdpTable API.
- public override IPEndPoint[] GetActiveUdpListeners()
+ public unsafe override IPEndPoint[] GetActiveUdpListeners()
  {
  uint size = 0;
  uint result = 0;
@@ -237,22 +237,25 @@ public override IPEndPoint[] GetActiveUdpListeners()
 
  if (result == Interop.IpHlpApi.ERROR_SUCCESS)
  {
+ var span = new ReadOnlySpan<byte>((byte*)buffer, (int)size);
+
  // The table info just gives us the number of rows.
- Interop.IpHlpApi.MibUdpTable udpTableInfo = Marshal.PtrToStructure<Interop.IpHlpApi.MibUdpTable>(buffer);
+ ref readonly Interop.IpHlpApi.MibUdpTable udpTableInfo = ref MemoryMarshal.AsRef<Interop.IpHlpApi.MibUdpTable>(span);
 
  if (udpTableInfo.numberOfEntries > 0)
  {
  // Skip over the tableinfo to get the inline rows.
- IntPtr newPtr = (IntPtr)((long)buffer + Marshal.SizeOf(udpTableInfo.numberOfEntries));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibUdpTable));
+
  for (int i = 0; i < udpTableInfo.numberOfEntries; i++)
  {
- Interop.IpHlpApi.MibUdpRow udpRow = Marshal.PtrToStructure<Interop.IpHlpApi.MibUdpRow>(newPtr);
+ ref readonly Interop.IpHlpApi.MibUdpRow udpRow = ref MemoryMarshal.AsRef<Interop.IpHlpApi.MibUdpRow>(span);
  int localPort = udpRow.localPort1 << 8 | udpRow.localPort2;
 
  udpListeners.Add(new IPEndPoint(udpRow.localAddr, (int)localPort));
 
  // We increment the pointer to the next row.
- newPtr = (IntPtr)((long)newPtr + Marshal.SizeOf(udpRow));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibUdpRow));
  }
  }
  }
@@ -289,23 +292,26 @@ public override IPEndPoint[] GetActiveUdpListeners()
 
  if (result == Interop.IpHlpApi.ERROR_SUCCESS)
  {
+ var span = new ReadOnlySpan<byte>((byte*)buffer, (int)size);
+
  // The table info just gives us the number of rows.
- Interop.IpHlpApi.MibUdp6TableOwnerPid udp6TableOwnerPid = Marshal.PtrToStructure<Interop.IpHlpApi.MibUdp6TableOwnerPid>(buffer);
+ ref readonly Interop.IpHlpApi.MibUdp6TableOwnerPid udp6TableOwnerPid = ref MemoryMarshal.AsRef<Interop.IpHlpApi.MibUdp6TableOwnerPid>(span);
 
  if (udp6TableOwnerPid.numberOfEntries > 0)
  {
  // Skip over the tableinfo to get the inline rows.
- IntPtr newPtr = (IntPtr)((long)buffer + Marshal.SizeOf(udp6TableOwnerPid.numberOfEntries));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibUdp6TableOwnerPid));
+
  for (int i = 0; i < udp6TableOwnerPid.numberOfEntries; i++)
  {
- Interop.IpHlpApi.MibUdp6RowOwnerPid udp6RowOwnerPid = Marshal.PtrToStructure<Interop.IpHlpApi.MibUdp6RowOwnerPid>(newPtr);
+ ref readonly Interop.IpHlpApi.MibUdp6RowOwnerPid udp6RowOwnerPid = ref MemoryMarshal.AsRef<Interop.IpHlpApi.MibUdp6RowOwnerPid>(span);
  int localPort = udp6RowOwnerPid.localPort1 << 8 | udp6RowOwnerPid.localPort2;
 
- udpListeners.Add(new IPEndPoint(new IPAddress(udp6RowOwnerPid.localAddr,
+ udpListeners.Add(new IPEndPoint(new IPAddress(udp6RowOwnerPid.localAddrAsSpan,
  udp6RowOwnerPid.localScopeId), localPort));
 
  // We increment the pointer to the next row.
- newPtr = (IntPtr)((long)newPtr + Marshal.SizeOf(udp6RowOwnerPid));
+ span = span.Slice(sizeof(Interop.IpHlpApi.MibUdp6RowOwnerPid));
  }
  }
  }

src/libraries/System.Net.NetworkInformation/src/System/Net/NetworkInformation/SystemTcpConnection.cs

@@ -11,7 +11,7 @@ internal class SystemTcpConnectionInformation : TcpConnectionInformation
  private readonly IPEndPoint _remoteEndPoint;
  private readonly TcpState _state;
 
- internal SystemTcpConnectionInformation(Interop.IpHlpApi.MibTcpRow row)
+ internal SystemTcpConnectionInformation(in Interop.IpHlpApi.MibTcpRow row)
  {
  _state = row.state;
 
@@ -25,7 +25,7 @@ internal SystemTcpConnectionInformation(Interop.IpHlpApi.MibTcpRow row)
  }
 
  // IPV6 version of the Tcp row.
- internal SystemTcpConnectionInformation(Interop.IpHlpApi.MibTcp6RowOwnerPid row)
+ internal unsafe SystemTcpConnectionInformation(in Interop.IpHlpApi.MibTcp6RowOwnerPid row)
  {
  _state = row.state;
 
@@ -34,8 +34,8 @@ internal SystemTcpConnectionInformation(Interop.IpHlpApi.MibTcp6RowOwnerPid row)
  int localPort = row.localPort1 << 8 | row.localPort2;
  int remotePort = ((_state == TcpState.Listen) ? 0 : row.remotePort1 << 8 | row.remotePort2);
 
- _localEndPoint = new IPEndPoint(new IPAddress(row.localAddr, row.localScopeId), (int)localPort);
- _remoteEndPoint = new IPEndPoint(new IPAddress(row.remoteAddr, row.remoteScopeId), (int)remotePort);
+ _localEndPoint = new IPEndPoint(new IPAddress(row.localAddrAsSpan, row.localScopeId), (int)localPort);
+ _remoteEndPoint = new IPEndPoint(new IPAddress(row.remoteAddrAsSpan, row.remoteScopeId), (int)remotePort);
  }
 
  public override TcpState State { get { return _state; } }