feat: report unknowns in sbom (#2998)

Signed-off-by: Keith Zantow <kzantow@gmail.com>
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>
Co-authored-by: Alex Goodman <wagoodman@users.noreply.github.com>

internal/task/unknowns_tasks.go

@@ -0,0 +1,114 @@
+package task
+
+import (
+	"context"
+	"strings"
+
+	"github.com/mholt/archiver/v3"
+
+	"github.com/anchore/syft/internal/log"
+	"github.com/anchore/syft/internal/sbomsync"
+	"github.com/anchore/syft/syft/cataloging"
+	"github.com/anchore/syft/syft/file"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/sbom"
+)
+
+const unknownsLabelerTaskName = "unknowns-labeler"
+
+func NewUnknownsLabelerTask(cfg cataloging.UnknownsConfig) Task {
+	return NewTask(unknownsLabelerTaskName, unknownsLabelerTask{cfg}.processUnknowns)
+}
+
+type unknownsLabelerTask struct {
+	cataloging.UnknownsConfig
+}
+
+// processUnknowns removes unknown entries that have valid packages reported for the locations
+func (c unknownsLabelerTask) processUnknowns(_ context.Context, resolver file.Resolver, builder sbomsync.Builder) error {
+	accessor := builder.(sbomsync.Accessor)
+	accessor.WriteToSBOM(func(s *sbom.SBOM) {
+		c.finalize(resolver, s)
+	})
+	return nil
+}
+
+func (c unknownsLabelerTask) finalize(resolver file.Resolver, s *sbom.SBOM) {
+	hasPackageReference := coordinateReferenceLookup(resolver, s)
+
+	if c.RemoveWhenPackagesDefined {
+		for coords := range s.Artifacts.Unknowns {
+			if !hasPackageReference(coords) {
+				continue
+			}
+			delete(s.Artifacts.Unknowns, coords)
+		}
+	}
+
+	if s.Artifacts.Unknowns == nil {
+		s.Artifacts.Unknowns = map[file.Coordinates][]string{}
+	}
+
+	if c.IncludeExecutablesWithoutPackages {
+		for coords := range s.Artifacts.Executables {
+			if !hasPackageReference(coords) {
+				s.Artifacts.Unknowns[coords] = append(s.Artifacts.Unknowns[coords], formatUnknown("no package identified in executable file", unknownsLabelerTaskName))
+			}
+		}
+	}
+
+	if c.IncludeUnexpandedArchives {
+		for coords := range s.Artifacts.FileMetadata {
+			unarchiver, notArchiveErr := archiver.ByExtension(coords.RealPath)
+			if unarchiver != nil && notArchiveErr == nil && !hasPackageReference(coords) {
+				s.Artifacts.Unknowns[coords] = append(s.Artifacts.Unknowns[coords], "archive not cataloged")
+			}
+		}
+	}
+}
+
+func formatUnknown(err string, task ...string) string {
+	return strings.Join(task, "/") + ": " + err
+}
+
+func coordinateReferenceLookup(resolver file.Resolver, s *sbom.SBOM) func(coords file.Coordinates) bool {
+	allPackageCoords := file.NewCoordinateSet()
+
+	// include all directly included locations that result in packages
+	for p := range s.Artifacts.Packages.Enumerate() {
+		allPackageCoords.Add(p.Locations.CoordinateSet().ToSlice()...)
+	}
+
+	// include owned files, for example specified by package managers.
+	// relationships for these owned files may be disabled, but we always want to include them
+	for p := range s.Artifacts.Packages.Enumerate() {
+		if f, ok := p.Metadata.(pkg.FileOwner); ok {
+			for _, ownedFilePath := range f.OwnedFiles() {
+				// resolve these owned files, as they may have symlinks
+				// but coordinates we will test against are always absolute paths
+				locations, err := resolver.FilesByPath(ownedFilePath)
+				if err != nil {
+					log.Debugf("unable to resolve owned file '%s': %v", ownedFilePath, err)
+				}
+				for _, loc := range locations {
+					allPackageCoords.Add(loc.Coordinates)
+				}
+			}
+		}
+	}
+
+	// include relationships
+	for _, r := range s.Relationships {
+		_, fromPkgOk := r.From.(pkg.Package)
+		fromFile, fromFileOk := r.From.(file.Coordinates)
+		_, toPkgOk := r.To.(pkg.Package)
+		toFile, toFileOk := r.To.(file.Coordinates)
+		if fromPkgOk && toFileOk {
+			allPackageCoords.Add(toFile)
+		} else if fromFileOk && toPkgOk {
+			allPackageCoords.Add(fromFile)
+		}
+	}
+
+	return allPackageCoords.Contains
+}