fix how we find parent process (#472)

Turns out BusyBox only implements a small portion of the [POSIX spec][1]
for its [ps][2], so our code that gets the parent process (and hence
`bmx print`) never worked on Alpine...
(I guess no one ever used `bmx print` on alpine...)

Switch to use native API call, which is actually easier.

[1]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/ps.html
[2]: https://boxmatrix.info/wiki/Property:ps

https://desire2learn.atlassian.net/browse/VUL-403

.github/workflows/publish.yml

@@ -45,9 +45,9 @@ jobs:
             Throw "Tag name format incorrect"
           }
           if ($env:PRERELEASE -eq 'true') {
-              $releaseUrl = gh release create "$env:RELEASE_TAG" --repo Brightspace/bmx --draft --prerelease --generate-notes --title "Release $env:RELEASE_TAG"
+              $releaseUrl = gh release create "$env:RELEASE_TAG" --repo Brightspace/bmx --draft --prerelease --generate-notes --title "Release $env:RELEASE_TAG" --target $env:GITHUB_SHA
           } else {
-              $releaseUrl = gh release create "$env:RELEASE_TAG" --repo Brightspace/bmx --draft --generate-notes --title "Release $env:RELEASE_TAG"
+              $releaseUrl = gh release create "$env:RELEASE_TAG" --repo Brightspace/bmx --draft --generate-notes --title "Release $env:RELEASE_TAG" --target $env:GITHUB_SHA
           }
           if ( $LASTEXITCODE -ne 0 ) { throw "Failed to create draft release" }
 

src/D2L.Bmx/WindowsParentProcess.cs → src/D2L.Bmx/ParentProcess.cs

@@ -2,43 +2,41 @@
 using System.Runtime.InteropServices;
 
 namespace D2L.Bmx;
+
 /**
 This file may eventually be replaced if the following dotnet runtime api proposals are implemented:
 - https://github.com/dotnet/runtime/issues/21941
 - https://github.com/dotnet/runtime/issues/24423
-
-Uses the same approach of calling NtQueryInformationProcess as in the PowerShell library
-https://github.com/PowerShell/PowerShell/blob/26f621952910e33840efb0c539fbef1e2a467a0d/src/System.Management.Automation/engine/ProcessCodeMethods.cs
 */
-internal partial class WindowsParentProcess {
+internal partial class ParentProcess {
+	public static string? GetParentProcessName() {
+		int parentPid = -1;
+		if( OperatingSystem.IsWindows() ) {
+			parentPid = GetWindowsParentProcessId();
+		} else if( OperatingSystem.IsLinux() || OperatingSystem.IsMacOS() ) {
+			parentPid = GetPosixParentProcessId();
+		}
+		if( parentPid == -1 ) {
+			return null;
+		}
+		return Process.GetProcessById( parentPid ).ProcessName;
+	}
 
-	[LibraryImport( "ntdll.dll", EntryPoint = "NtQueryInformationProcess" )]
-	internal static partial int NtQueryInformationProcess(
-		IntPtr processHandle,
-		int processInformationClass,
-		ref PROCESS_BASIC_INFORMATION processInformation,
-		int processInformationLength,
-		out int returnLength
-	);
+	[LibraryImport( "libc", EntryPoint = "getppid" )]
+	private static partial int GetPosixParentProcessId();
 
-	internal struct PROCESS_BASIC_INFORMATION {
-		public IntPtr ExitStatus;
-		public IntPtr PebBaseAddress;
-		public IntPtr AffinityMask;
-		public IntPtr BasePriority;
-		public UIntPtr UniqueProcessId;
-		public UIntPtr InheritedFromUniqueProcessId;
-	}
 
-	private static int GetParentProcessId() {
+	// Uses the same approach of calling NtQueryInformationProcess as in the PowerShell library
+	// https://github.com/PowerShell/PowerShell/blob/26f621952910e33840efb0c539fbef1e2a467a0d/src/System.Management.Automation/engine/ProcessCodeMethods.cs
+	private static int GetWindowsParentProcessId() {
 		var proc = Process.GetCurrentProcess();
 		var pbi = new PROCESS_BASIC_INFORMATION();
 		int status = NtQueryInformationProcess(
 			proc.Handle,
 			0,
 			ref pbi,
 			Marshal.SizeOf<PROCESS_BASIC_INFORMATION>(),
-			out int infoLen
+			out _
 		);
 
 		if( status != 0 ) {
@@ -47,7 +45,21 @@ out int infoLen
 		return (int)pbi.InheritedFromUniqueProcessId;
 	}
 
-	public static string GetParentProcessName() {
-		return Process.GetProcessById( GetParentProcessId() ).ProcessName;
+	[LibraryImport( "ntdll.dll" )]
+	private static partial int NtQueryInformationProcess(
+		IntPtr processHandle,
+		int processInformationClass,
+		ref PROCESS_BASIC_INFORMATION processInformation,
+		int processInformationLength,
+		out int returnLength
+	);
+
+	private struct PROCESS_BASIC_INFORMATION {
+		public IntPtr ExitStatus;
+		public IntPtr PebBaseAddress;
+		public IntPtr AffinityMask;
+		public IntPtr BasePriority;
+		public UIntPtr UniqueProcessId;
+		public UIntPtr InheritedFromUniqueProcessId;
 	}
 }

src/D2L.Bmx/PrintHandler.cs

@@ -38,14 +38,7 @@ bool cacheAwsCredentials
 		} else if( string.Equals( format, PrintFormat.Json, StringComparison.OrdinalIgnoreCase ) ) {
 			PrintJson( awsCreds );
 		} else {
-			string? procName = null;
-			if( OperatingSystem.IsWindows() ) {
-				procName = WindowsParentProcess.GetParentProcessName().ToLower();
-			} else if( OperatingSystem.IsLinux() || OperatingSystem.IsMacOS() ) {
-				procName = UnixParentProcess.GetParentProcessName().ToLower();
-			}
-
-			switch( procName ) {
+			switch( ParentProcess.GetParentProcessName() ) {
 				case "pwsh":
 				case "powershell":
 					PrintPowershell( awsCreds );