Only use ps 'flags' for macOS

src/SSHDebugPS/AD7/AD7Process.cs

@@ -25,7 +25,7 @@ internal class AD7Process : IDebugProcess2, IDebugProcessSecurity2, IDebugProces
         /// <summary>
         /// Flags are only used in ps command scenarios. It will be set to 0 for others.
         /// </summary>
-        private readonly uint _flags;
+        private readonly uint? _flags;
 
         /// <summary>
         /// Returns true if _commandLine appears to hold a real file name + args rather than just a description
@@ -297,7 +297,7 @@ string IDebugUnixProcess.GetProcessArchitecture()
         {
             // For Apple Silicon M1, it is possible that the process we are attaching to is being emulated as x86_64. 
             // The process is emulated if it has process flags has P_TRANSLATED (0x20000).
-            if (_port.IsOSX() && _systemArch == "arm64")
+            if (_port.IsOSX() && _systemArch == "arm64" && _flags.HasValue)
             {
                 if ((_flags & 0x20000) != 0)
                 {

src/SSHDebugPS/IConnection.cs

@@ -1,7 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Threading;
 using Microsoft.DebugEngineHost;
 using Microsoft.SSHDebugPS.Utilities;
@@ -104,13 +106,13 @@ public class Process
         /// <summary>
         /// Only used by the PSOutputParser
         /// </summary>
-        public uint Flags { get; private set; }
+        public uint? Flags { get; private set; }
         public string SystemArch { get; private set; }
         public string CommandLine { get; private set; }
         public string UserName { get; private set; }
         public bool IsSameUser { get; private set; }
 
-        public Process(uint id, string arch, uint flags, string userName, string commandLine, bool isSameUser)
+        public Process(uint id, string arch, uint? flags, string userName, string commandLine, bool isSameUser)
         {
             this.Id = id;
             this.Flags = flags;
@@ -121,15 +123,37 @@ public Process(uint id, string arch, uint flags, string userName, string command
         }
     }
 
+    internal static class OperatingSystemStringConverter
+    {
+        internal static PlatformID ConvertToPlatformID(string value)
+        {
+            if (!string.IsNullOrEmpty(value))
+            {
+                value = value.ToLowerInvariant();
+                if (value.Contains("darwin"))
+                {
+                    return PlatformID.MacOSX;
+                } else if (value.Contains("linux"))
+                {
+                    return PlatformID.Unix;
+                }
+            }
+            Debug.Fail($"Expected a valid platform '{value}' of darwin or linux, but falling back to linux.");
+            return PlatformID.Unix;
+        }
+    }
+
     internal class SystemInformation
     {
         public string UserName { get; private set; }
         public string Architecture { get; private set; }
+        public PlatformID Platform { get; private set; }
 
-        public SystemInformation(string username, string architecture)
+        public SystemInformation(string username, string architecture, PlatformID platform)
         {
             this.UserName = username;
             this.Architecture = architecture;
+            Platform = platform;
         }
     }
 }

src/SSHDebugPS/PSOutputParser.cs

@@ -59,28 +59,27 @@ public string Extract(string line)
         // Use padding to expand column width. 10 for pid and 32 for userid as that is the max size for each
         // Tested this format with different distributions of Linux and container distributions. This command (and the alternative without the flags) seems 
         // to be the one that works the best between standard *nix and BusyBox implementations of ps.
-        private const string PSCommandLineFormat = "ps{0}-o pid=pppppppppp -o flags=ffffffff -o ruser=rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr -o args";
+        private const string PSCommandLineFormat = "ps{0}-o pid=pppppppppp{1} -o ruser=rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr -o args";
         private SystemInformation _currentSystemInformation;
         private ColumnDef _pidCol;
         private ColumnDef _flagsCol;
         private ColumnDef _ruserCol;
         private ColumnDef _argsCol;
 
-        public static string PSCommandLine = PSCommandLineFormat.FormatInvariantWithArgs(" axww ");
-        public static string AltPSCommandLine = PSCommandLineFormat.FormatInvariantWithArgs(" ");
+        // In order to determine the architecture of a process, we need to run the ps command with 'flags'.
+        // However, certain of distros of Linux do not support flags, so only add this for macOS.
+        private string PSFlagFormat => _currentSystemInformation.Platform == PlatformID.MacOSX ? " -o flags=ffffffff" : string.Empty;
 
-        public static List<Process> Parse(string output, SystemInformation systemInformation)
-        {
-            return new PSOutputParser().ParseInternal(output, systemInformation);
-        }
+        public string PSCommandLine => PSCommandLineFormat.FormatInvariantWithArgs(" axww ", PSFlagFormat);
+        public string AltPSCommandLine => PSCommandLineFormat.FormatInvariantWithArgs(" ", PSFlagFormat);
 
-        private PSOutputParser()
+        public PSOutputParser(SystemInformation systemInformation)
         {
+            _currentSystemInformation = systemInformation;
         }
 
-        private List<Process> ParseInternal(string output, SystemInformation systemInformation)
+        public List<Process> Parse(string output)
         {
-            _currentSystemInformation = systemInformation;
             List<Process> processList = new List<Process>();
 
             using (var reader = new StringReader(output))
@@ -136,14 +135,18 @@ private bool ProcessHeaderLine(/*OPTIONAL*/ string headerLine)
             if (!SkipNonWhitespace(headerLine, ref index))
                 return false;
 
-            _flagsCol = new ColumnDef(colStart, index);
+            /// <see cref PSFlagFormat/> on why this is only executed for macOS.
+            if (_currentSystemInformation.Platform == PlatformID.MacOSX)
+            {
+                _flagsCol = new ColumnDef(colStart, index);
 
-            if (!SkipWhitespace(headerLine, ref index))
-                return false;
+                if (!SkipWhitespace(headerLine, ref index))
+                    return false;
 
-            colStart = index;
-            if (!SkipNonWhitespace(headerLine, ref index))
-                return false;
+                colStart = index;
+                if (!SkipNonWhitespace(headerLine, ref index))
+                    return false;
+            }
 
             _ruserCol = new ColumnDef(colStart, index);
 
@@ -170,10 +173,15 @@ private Process SplitPSLine(string line)
             if (!uint.TryParse(pidText, NumberStyles.None, CultureInfo.InvariantCulture, out pid))
                 return null;
 
-            uint flags;
-            string flagsText = _flagsCol.Extract(line);
-            if (!uint.TryParse(flagsText, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out flags))
-                return null;
+            uint? flags = null;
+            /// <see cref PSFlagFormat/> on why this is only executed for macOS.
+            if (_currentSystemInformation.Platform == PlatformID.MacOSX)
+            {
+                string flagsText = _flagsCol.Extract(line);
+                if (!uint.TryParse(flagsText, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out uint tempFlags))
+                    return null;
+                flags = tempFlags;
+            }
 
             string ruser = _ruserCol.Extract(line);
             string commandLine = _argsCol.Extract(line);

src/SSHDebugPS/PipeConnection.cs

@@ -98,8 +98,8 @@ public override bool IsLinux()
         /// <returns>SystemInformation containing username and architecture. If it was unable to obtain any of these, the value will be set to string.Empty.</returns>
         public SystemInformation GetSystemInformation()
         {
-            string commandOutput;
-            string errorMessage;
+            string commandOutput = string.Empty;
+            string errorMessage = string.Empty;
             int exitCode;
 
             string username = string.Empty;
@@ -108,13 +108,19 @@ public SystemInformation GetSystemInformation()
                 username = commandOutput;
             }
 
+            string platform = string.Empty;
+            if (ExecuteCommand("uname", Timeout.Infinite, commandOutput: out commandOutput, errorMessage: out errorMessage, exitCode: out exitCode))
+            {
+                platform = commandOutput;
+            }
+
             string architecture = string.Empty;
             if (ExecuteCommand("uname -m", Timeout.Infinite, commandOutput: out commandOutput, errorMessage: out errorMessage, exitCode: out exitCode))
             {
                 architecture = commandOutput;
             }
 
-            return new SystemInformation(username, architecture);
+            return new SystemInformation(username, architecture, OperatingSystemStringConverter.ConvertToPlatformID(platform));
         }
 
         public override List<Process> ListProcesses()
@@ -152,12 +158,15 @@ private bool PSListProcess(SystemInformation systemInformation, out string error
             errorMessage = string.Empty;
             string commandOutput;
             int exitCode;
-            if (!ExecuteCommand(PSOutputParser.PSCommandLine, Timeout.Infinite, out commandOutput, out errorMessage, out exitCode))
+
+            PSOutputParser psOutputParser = new PSOutputParser(systemInformation);
+
+            if (!ExecuteCommand(psOutputParser.PSCommandLine, Timeout.Infinite, out commandOutput, out errorMessage, out exitCode))
             {
                 // Clear output and errorMessage
                 commandOutput = string.Empty;
                 errorMessage = string.Empty;
-                if (!ExecuteCommand(PSOutputParser.AltPSCommandLine, Timeout.Infinite, out commandOutput, out errorMessage, out exitCode))
+                if (!ExecuteCommand(psOutputParser.AltPSCommandLine, Timeout.Infinite, out commandOutput, out errorMessage, out exitCode))
                 {
                     if (exitCode == 127)
                     {
@@ -174,7 +183,7 @@ private bool PSListProcess(SystemInformation systemInformation, out string error
                 }
             }
 
-            processes = PSOutputParser.Parse(commandOutput, systemInformation);
+            processes = psOutputParser.Parse(commandOutput);
             return true;
         }
 

src/SSHDebugPS/SSH/SSHConnection.cs

@@ -52,22 +52,31 @@ public override List<Process> ListProcesses()
                 username = usernameCommand.Output.TrimEnd('\n', '\r'); // trim line endings because 'id' command ends with a newline
             }
 
+            string operatingSystem = string.Empty;
+            var operatingSystemCommand = _remoteSystem.Shell.ExecuteCommand("uname", Timeout.InfiniteTimeSpan);
+            if (operatingSystemCommand.ExitCode == 0)
+            {
+                operatingSystem = operatingSystemCommand.Output.TrimEnd('\n', '\r'); // trim line endings because 'uname' command ends with a newline
+            }
+
             string architecture = string.Empty;
             var architectureCommand = _remoteSystem.Shell.ExecuteCommand("uname -m", Timeout.InfiniteTimeSpan);
             if (architectureCommand.ExitCode == 0)
             {
                 architecture = architectureCommand.Output.TrimEnd('\n', '\r'); // trim line endings because 'uname -m' command ends with a newline
             }
 
-            SystemInformation systemInformation = new SystemInformation(username, architecture);
+            SystemInformation systemInformation = new SystemInformation(username, architecture, OperatingSystemStringConverter.ConvertToPlatformID(operatingSystem));
+
+            PSOutputParser psOutputParser = new PSOutputParser(systemInformation);
 
-            var command = _remoteSystem.Shell.ExecuteCommand(PSOutputParser.PSCommandLine, Timeout.InfiniteTimeSpan);
+            var command = _remoteSystem.Shell.ExecuteCommand(psOutputParser.PSCommandLine, Timeout.InfiniteTimeSpan);
             if (command.ExitCode != 0)
             {
                 throw new CommandFailedException(StringResources.Error_PSFailed);
             }
 
-            return PSOutputParser.Parse(command.Output, systemInformation);
+            return psOutputParser.Parse(command.Output);
         }
 
         /// <inheritdoc/>

src/SSHDebugTests/PSOutputParserTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using Microsoft.SSHDebugPS;
 using System.Collections.Generic;
 using Xunit;
@@ -9,22 +10,46 @@ namespace SSHDebugTests
 {
     public class PSOutputParserTests
     {
+        [Fact]
+        public void PSOutputParser_macOS()
+        {
+            const string username = "username";
+            const string architecture = "x86_64";
+            const string input =
+               "pppppppppp ffffffff rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr ARGS\n" +
+               "1          4004     root                             /sbin/launchd\n" +
+               "50         1004004  root                             /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/FSEvents.framework/Versions/A/Support/fseventsd\n" +
+               "70         1004004  root                             /System/Library/Frameworks/CoreServices.framework/Frameworks/Metadata.framework/Support/mds\n" +
+               "83         4004     _timed                           /usr/libexec/timed\n" +
+               "96         80004104 root                             /System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow console\n" +
+               "7835       4104     username                         ps axww -o pid=pppppppppp -o flags=ffffffff -o ruser=rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr -o args\n";
+
+            PSOutputParser psOutputParser = new PSOutputParser(new SystemInformation(username, architecture, PlatformID.MacOSX));
+            List<Process> r = psOutputParser.Parse(input);
+            Assert.Equal(5, r.Count);
+            // Testing flags here as PID USER ARGS are tested in the other tests.
+            Assert.Equal(r[0].Flags.Value, (uint)0x4004);
+            Assert.Equal(r[1].Flags.Value, (uint)0x1004004);
+            Assert.Equal(r[4].Flags.Value, (uint)0x80004104);
+        }
+
         [Fact]
         public void PSOutputParser_Ubuntu14()
         {
             const string username = "greggm";
             const string architecture = "x86_64";
             // example output from ps on a real Ubuntu 14 machine (with many processes removed):
             const string input =
-                "pppppppppp ffffffff rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr COMMAND\n" +
-                "         1        0 root                             /sbin/init\n" +
-                "         2        0 root                             [kthreadd]\n" +
-                "       720        0 message+                         dbus-daemon --system --fork\n" +
-                "      2389        0 greggm                           -bash\n" +
-                "      2580        0 root                             /sbin/dhclient -d -sf /usr/lib/NetworkManager/nm-dhcp-client.action -pf /run/sendsigs.omit.d/network-manager.dhclient-eth0.pid -lf /var/lib/NetworkManager/dhclient-d08a482b-ff90-4007-9b13-6500eb94b673-eth0.lease -cf /var/lib/NetworkManager/dhclient-eth0.conf eth0\n" +
-                "      2913        0 greggm                           ps axww -o pid=pppppppppp -o flags=ffffffff -o ruser=rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr -o args\n";
+                "pppppppppp rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr COMMAND\n" +
+                "         1 root                             /sbin/init\n" +
+                "         2 root                             [kthreadd]\n" +
+                "       720 message+                         dbus-daemon --system --fork\n" +
+                "      2389 greggm                           -bash\n" +
+                "      2580 root                             /sbin/dhclient -d -sf /usr/lib/NetworkManager/nm-dhcp-client.action -pf /run/sendsigs.omit.d/network-manager.dhclient-eth0.pid -lf /var/lib/NetworkManager/dhclient-d08a482b-ff90-4007-9b13-6500eb94b673-eth0.lease -cf /var/lib/NetworkManager/dhclient-eth0.conf eth0\n" +
+                "      2913 greggm                           ps axww -o pid=pppppppppp -o ruser=rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr -o args\n";
 
-            List<Process> r = PSOutputParser.Parse(input, new SystemInformation(username, architecture));
+            PSOutputParser psOutputParser = new PSOutputParser(new SystemInformation(username, architecture, PlatformID.Unix));
+            List<Process> r = psOutputParser.Parse(input);
             Assert.Equal(5, r.Count);
 
             uint[] pids = { 1, 2, 720, 2389, 2580 };
@@ -47,10 +72,11 @@ public void PSOutputParser_SmallCol()
             const string architecture = "x86_64";
             // made up output for what could happen if the fields were all just 1 character in size
             const string input =
-                "A B C D\n" +
-                "9 0 r /sbin/init";
+                "A B C\n" +
+                "9 r /sbin/init";
 
-            List<Process> r = PSOutputParser.Parse(input, new SystemInformation(username, architecture));
+            PSOutputParser psOutputParser = new PSOutputParser(new SystemInformation(username, architecture, PlatformID.Unix));
+            List<Process> r = psOutputParser.Parse(input);
             Assert.Single(r);
             Assert.Equal<uint>(9, r[0].Id);
             Assert.Equal("r", r[0].UserName);
@@ -64,12 +90,13 @@ public void PSOutputParser_NoUserName()
             const string username = "";
             const string architecture = "";
             const string input =
-                "pppppppppp ffffffff rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr COMMAND\n" +
-                "         1        0 root                             /sbin/init\n" +
-                "       720        0                                  dbus-daemon --system --fork\n" +
-                "      2389        0 greggm                           -bash\n";
+                "pppppppppp rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr COMMAND\n" +
+                "         1 root                             /sbin/init\n" +
+                "       720                                  dbus-daemon --system --fork\n" +
+                "      2389 greggm                           -bash\n";
 
-            List<Process> r = PSOutputParser.Parse(input, new SystemInformation(username, architecture));
+            PSOutputParser psOutputParser = new PSOutputParser(new SystemInformation(username, architecture, PlatformID.Unix));
+            List<Process> r = psOutputParser.Parse(input);
             Assert.Equal(3, r.Count);
 
             uint[] pids = { 1, 720, 2389 };