Annotate System.Net.Ping for nullable reference types

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

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Net.NetworkInformation;
 using System.Runtime.InteropServices;
@@ -22,7 +23,7 @@ internal struct IPOptions
             internal byte optionsSize;
             internal IntPtr optionsData;
 
-            internal IPOptions(PingOptions options)
+            internal IPOptions(PingOptions? options)
             {
                 ttl = 128;
                 tos = 0;

src/libraries/Common/src/System/Net/NetworkInformation/UnixCommandLinePing.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System.Globalization;
 using System.IO;
 using System.Runtime.InteropServices;
@@ -16,14 +17,14 @@ internal static class UnixCommandLinePing
         private const string s_ipv4PingFile = "ping";
         private const string s_ipv6PingFile = "ping6";
 
-        private static readonly string s_discoveredPing4UtilityPath = GetPingUtilityPath(ipv4: true);
-        private static readonly string s_discoveredPing6UtilityPath = GetPingUtilityPath(ipv4: false);
+        private static readonly string? s_discoveredPing4UtilityPath = GetPingUtilityPath(ipv4: true);
+        private static readonly string? s_discoveredPing6UtilityPath = GetPingUtilityPath(ipv4: false);
         private static readonly bool s_isBSD = RuntimeInformation.IsOSPlatform(OSPlatform.OSX) || RuntimeInformation.IsOSPlatform(OSPlatform.Create("FREEBSD"));
         private static readonly Lazy<bool> s_isBusybox = new Lazy<bool>(() => IsBusyboxPing(s_discoveredPing4UtilityPath));
 
         // We don't want to pick up an arbitrary or malicious ping
         // command, so that's why we do the path probing ourselves.
-        private static string GetPingUtilityPath(bool ipv4)
+        private static string? GetPingUtilityPath(bool ipv4)
         {
             string fileName = ipv4 ? s_ipv4PingFile : s_ipv6PingFile;
             foreach (string folder in s_binFolders)
@@ -39,14 +40,17 @@ private static string GetPingUtilityPath(bool ipv4)
         }
 
         // Check if found ping is symlink to busybox like alpine /bin/ping -> /bin/busybox
-        private static unsafe bool IsBusyboxPing(string pingBinary)
+        private static unsafe bool IsBusyboxPing(string? pingBinary)
         {
-            string linkedName = Interop.Sys.ReadLink(pingBinary);
-
-            // If pingBinary is not link linkedName will be null
-            if (linkedName != null && linkedName.EndsWith("busybox", StringComparison.Ordinal))
+            if (pingBinary != null)
             {
-                return true;
+                string? linkedName = Interop.Sys.ReadLink(pingBinary);
+
+                // If pingBinary is not link linkedName will be null
+                if (linkedName != null && linkedName.EndsWith("busybox", StringComparison.Ordinal))
+                {
+                    return true;
+                }
             }
 
             return false;
@@ -57,12 +61,12 @@ public enum PingFragmentOptions { Default, Do, Dont };
         /// <summary>
         /// The location of the IPv4 ping utility on the current machine.
         /// </summary>
-        public static string Ping4UtilityPath { get { return s_discoveredPing4UtilityPath; } }
+        public static string? Ping4UtilityPath { get { return s_discoveredPing4UtilityPath; } }
 
         /// <summary>
         /// The location of the IPv6 ping utility on the current machine.
         /// </summary>
-        public static string Ping6UtilityPath { get { return s_discoveredPing6UtilityPath; } }
+        public static string? Ping6UtilityPath { get { return s_discoveredPing6UtilityPath; } }
 
         /// <summary>
         /// Constructs command line arguments appropriate for the ping or ping6 utility.

src/libraries/Common/src/System/Net/SocketAddress.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System.Diagnostics;
 using System.Globalization;
 using System.Net.Sockets;
@@ -179,9 +180,9 @@ internal int GetAddressSizeOffset()
             return Buffer.Length - IntPtr.Size;
         }
 
-        public override bool Equals(object comparand)
+        public override bool Equals(object? comparand)
         {
-            SocketAddress castedComparand = comparand as SocketAddress;
+            SocketAddress? castedComparand = comparand as SocketAddress;
             if (castedComparand == null || this.Size != castedComparand.Size)
             {
                 return false;

src/libraries/System.Net.Ping/ref/System.Net.Ping.cs

@@ -37,34 +37,34 @@ public enum IPStatus
     public partial class Ping : System.ComponentModel.Component
     {
         public Ping() { }
-        public event System.Net.NetworkInformation.PingCompletedEventHandler PingCompleted { add { } remove { } }
+        public event System.Net.NetworkInformation.PingCompletedEventHandler? PingCompleted { add { } remove { } }
         protected override void Dispose(bool disposing) { }
         protected void OnPingCompleted(System.Net.NetworkInformation.PingCompletedEventArgs e) { }
         public System.Net.NetworkInformation.PingReply Send(System.Net.IPAddress address) { throw null; }
         public System.Net.NetworkInformation.PingReply Send(System.Net.IPAddress address, int timeout) { throw null; }
         public System.Net.NetworkInformation.PingReply Send(System.Net.IPAddress address, int timeout, byte[] buffer) { throw null; }
-        public System.Net.NetworkInformation.PingReply Send(System.Net.IPAddress address, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions options) { throw null; }
+        public System.Net.NetworkInformation.PingReply Send(System.Net.IPAddress address, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions? options) { throw null; }
         public System.Net.NetworkInformation.PingReply Send(string hostNameOrAddress) { throw null; }
         public System.Net.NetworkInformation.PingReply Send(string hostNameOrAddress, int timeout) { throw null; }
         public System.Net.NetworkInformation.PingReply Send(string hostNameOrAddress, int timeout, byte[] buffer) { throw null; }
-        public System.Net.NetworkInformation.PingReply Send(string hostNameOrAddress, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions options) { throw null; }
-        public void SendAsync(System.Net.IPAddress address, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions options, object userToken) { }
-        public void SendAsync(System.Net.IPAddress address, int timeout, byte[] buffer, object userToken) { }
-        public void SendAsync(System.Net.IPAddress address, int timeout, object userToken) { }
-        public void SendAsync(System.Net.IPAddress address, object userToken) { }
-        public void SendAsync(string hostNameOrAddress, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions options, object userToken) { }
-        public void SendAsync(string hostNameOrAddress, int timeout, byte[] buffer, object userToken) { }
-        public void SendAsync(string hostNameOrAddress, int timeout, object userToken) { }
-        public void SendAsync(string hostNameOrAddress, object userToken) { }
+        public System.Net.NetworkInformation.PingReply Send(string hostNameOrAddress, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions? options) { throw null; }
+        public void SendAsync(System.Net.IPAddress address, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions? options, object? userToken) { }
+        public void SendAsync(System.Net.IPAddress address, int timeout, byte[] buffer, object? userToken) { }
+        public void SendAsync(System.Net.IPAddress address, int timeout, object? userToken) { }
+        public void SendAsync(System.Net.IPAddress address, object? userToken) { }
+        public void SendAsync(string hostNameOrAddress, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions? options, object? userToken) { }
+        public void SendAsync(string hostNameOrAddress, int timeout, byte[] buffer, object? userToken) { }
+        public void SendAsync(string hostNameOrAddress, int timeout, object? userToken) { }
+        public void SendAsync(string hostNameOrAddress, object? userToken) { }
         public void SendAsyncCancel() { }
         public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(System.Net.IPAddress address) { throw null; }
         public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(System.Net.IPAddress address, int timeout) { throw null; }
         public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(System.Net.IPAddress address, int timeout, byte[] buffer) { throw null; }
-        public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(System.Net.IPAddress address, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions options) { throw null; }
+        public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(System.Net.IPAddress address, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions? options) { throw null; }
         public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(string hostNameOrAddress) { throw null; }
         public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(string hostNameOrAddress, int timeout) { throw null; }
         public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(string hostNameOrAddress, int timeout, byte[] buffer) { throw null; }
-        public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(string hostNameOrAddress, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions options) { throw null; }
+        public System.Threading.Tasks.Task<System.Net.NetworkInformation.PingReply> SendPingAsync(string hostNameOrAddress, int timeout, byte[] buffer, System.Net.NetworkInformation.PingOptions? options) { throw null; }
     }
     public partial class PingCompletedEventArgs : System.ComponentModel.AsyncCompletedEventArgs
     {
@@ -75,8 +75,8 @@ public partial class PingCompletedEventArgs : System.ComponentModel.AsyncComplet
     public partial class PingException : System.InvalidOperationException
     {
         protected PingException(System.Runtime.Serialization.SerializationInfo serializationInfo, System.Runtime.Serialization.StreamingContext streamingContext) { }
-        public PingException(string message) { }
-        public PingException(string message, System.Exception innerException) { }
+        public PingException(string? message) { }
+        public PingException(string? message, System.Exception? innerException) { }
     }
     public partial class PingOptions
     {
@@ -90,7 +90,7 @@ public partial class PingReply
         internal PingReply() { }
         public System.Net.IPAddress Address { get { throw null; } }
         public byte[] Buffer { get { throw null; } }
-        public System.Net.NetworkInformation.PingOptions Options { get { throw null; } }
+        public System.Net.NetworkInformation.PingOptions? Options { get { throw null; } }
         public long RoundtripTime { get { throw null; } }
         public System.Net.NetworkInformation.IPStatus Status { get { throw null; } }
     }

src/libraries/System.Net.Ping/ref/System.Net.Ping.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.Net.Ping.cs" />

src/libraries/System.Net.Ping/src/System.Net.Ping.csproj

@@ -4,6 +4,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <NoWarn>$(NoWarn);CS1573</NoWarn>
     <TargetFrameworks>$(NetCoreAppCurrent)-Windows_NT;$(NetCoreAppCurrent)-Unix</TargetFrameworks>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Net\NetworkInformation\IPStatus.cs" />