private void InvalidateSidebandFile(string sidebandFile, SidebandIntegrityCheckFailReason kind)
{
XAssert.FileExists(sidebandFile, "Sideband file for pipA not found.");
switch (kind)
{
case SidebandIntegrityCheckFailReason.FileNotFound:
AssertDeleteFile(sidebandFile, "Could not delete sideband file for pipA.");
break;
case SidebandIntegrityCheckFailReason.ChecksumMismatch:
File.WriteAllText(path: sidebandFile, contents: "bogus sideband file");
break;
case SidebandIntegrityCheckFailReason.MetadataMismatch:
SidebandMetadata alteredMetadata;
// read the header and the metadata from the original
using (var reader = new SidebandReader(sidebandFile))
{
XAssert.IsTrue(reader.ReadHeader(ignoreChecksum: false));
var originalMetadata = reader.ReadMetadata();
alteredMetadata = new SidebandMetadata(originalMetadata.PipSemiStableHash + 1, originalMetadata.StaticPipFingerprint);
}
// overwrite the original with a different metadata file where PiPSemiStableHash is different than in the original
using (var writer = new SidebandWriter(alteredMetadata, sidebandFile, null))
{
writer.EnsureHeaderWritten();
}
break;
default:
XAssert.Fail($"Unknown kind: {kind}");
break;
}
}
private bool TryReadSidebandFile(string filename, out SidebandMetadata metadata, out IEnumerable <string> paths)
{
try
{
// We ignore the checksum because even when the sideband file is compromised,
// it is possible to call <see cref="ReadRecordedPaths"/> which will then try to recover
// as many recorded paths as possible.
(paths, metadata) = SidebandReader.ReadSidebandFile(filename, ignoreChecksum: true);
return(true);
}
catch (Exception e) when(e is BuildXLException || e is IOException || e is OperationCanceledException)
{
Processes.Tracing.Logger.Log.CannotReadSidebandFileWarning(LoggingContext, filename, e.Message);
metadata = null;
paths = null;
return(false);
}
}
private SidebandWriter CreateWriter(string sidebandFile = null, IReadOnlyList <string> rootDirs = null, SidebandMetadata metadata = null)
{
sidebandFile = sidebandFile ?? Path.Combine(TemporaryDirectory, $"{s_logDirectoryCounter++}", "log");
Directory.CreateDirectory(Path.GetDirectoryName(sidebandFile));
return(new SidebandWriter(
metadata: metadata ?? DefaultSidebandMetadata,
sidebandLogFile: sidebandFile,
rootDirectories: rootDirs));
}
