From 566024fc8fd6ebacb0956de2d4caacda64db2ded Mon Sep 17 00:00:00 2001
From: Lorenzo Susini <susinilorenzo1@gmail.com>
Date: Tue, 1 Aug 2023 15:12:16 +0000
Subject: [PATCH] update: allow to extract directories for asset files

Signed-off-by: Lorenzo Susini <susinilorenzo1@gmail.com>
---
 cmd/artifact/install/install.go |  2 +-
 internal/follower/follower.go   |  2 +-
 internal/utils/extract.go       | 29 +++++++++++++++++++++++------
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/cmd/artifact/install/install.go b/cmd/artifact/install/install.go
index 62dfd2e46..688d76c2c 100644
--- a/cmd/artifact/install/install.go
+++ b/cmd/artifact/install/install.go
@@ -333,7 +333,7 @@ func (o *artifactInstallOptions) RunArtifactInstall(ctx context.Context, args []
 		}
 
 		// Extract artifact and move it to its destination directory
-		_, err = utils.ExtractTarGz(f, destDir)
+		_, err = utils.ExtractTarGz(f, destDir, result.Type)
 		if err != nil {
 			return fmt.Errorf("cannot extract %q to %q: %w", result.Filename, destDir, err)
 		}
diff --git a/internal/follower/follower.go b/internal/follower/follower.go
index 6eed041fd..8c8a19e05 100644
--- a/internal/follower/follower.go
+++ b/internal/follower/follower.go
@@ -282,7 +282,7 @@ func (f *Follower) pull(ctx context.Context) (filePaths []string, res *oci.Regis
 	}
 
 	// Extract artifact and move it to its destination directory
-	filePaths, err = utils.ExtractTarGz(file, f.tmpDir)
+	filePaths, err = utils.ExtractTarGz(file, f.tmpDir, res.Type)
 	if err != nil {
 		return filePaths, res, fmt.Errorf("unable to extract %q to %q: %w", res.Filename, f.tmpDir, err)
 	}
diff --git a/internal/utils/extract.go b/internal/utils/extract.go
index 70be8e725..93fc5ea49 100644
--- a/internal/utils/extract.go
+++ b/internal/utils/extract.go
@@ -23,11 +23,13 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"github.com/falcosecurity/falcoctl/pkg/oci"
 )
 
 // ExtractTarGz extracts a *.tar.gz compressed archive and moves its content to destDir.
 // Returns a slice containing the full path of the extracted files.
-func ExtractTarGz(gzipStream io.Reader, destDir string) ([]string, error) {
+func ExtractTarGz(gzipStream io.Reader, destDir string, artifactType oci.ArtifactType) ([]string, error) {
 	var files []string
 
 	uncompressedStream, err := gzip.NewReader(gzipStream)
@@ -37,6 +39,7 @@ func ExtractTarGz(gzipStream io.Reader, destDir string) ([]string, error) {
 
 	tarReader := tar.NewReader(uncompressedStream)
 
+	dirs := 0
 	for {
 		header, err := tarReader.Next()
 
@@ -48,14 +51,28 @@ func ExtractTarGz(gzipStream io.Reader, destDir string) ([]string, error) {
 			return nil, err
 		}
 
+		if strings.Contains(header.Name, "..") {
+			return nil, fmt.Errorf("not allowed relative path in tar archive")
+		}
+
 		switch header.Typeflag {
 		case tar.TypeDir:
-			return nil, fmt.Errorf("unexepected dir inside the archive, expected to find only files without any tree structure")
-		case tar.TypeReg:
-			if strings.Contains(header.Name, "..") {
-				return nil, fmt.Errorf("not allowed relative path in tar archive")
+			if artifactType == oci.Plugin || artifactType == oci.Rulesfile {
+				return nil, fmt.Errorf("unexepected dir inside the archive, "+
+					"expected to find only files without any tree structure for %q artifacts", artifactType.String())
+			} else if artifactType == oci.Asset {
+				if dirs > 1 {
+					return nil, fmt.Errorf("malformed tar archive, expected to " +
+						"find only one directory containing all the assets files, not multiple directories")
+				}
+				destDir = filepath.Join(destDir, filepath.Clean(header.Name))
+				err = os.Mkdir(destDir, header.FileInfo().Mode().Perm())
+				if err != nil && !errors.Is(err, os.ErrExist) {
+					return nil, fmt.Errorf("unable to extract dir from the archive: %w", err)
+				}
+				dirs++
 			}
-
+		case tar.TypeReg:
 			f := filepath.Join(destDir, filepath.Clean(header.Name))
 			outFile, err := os.Create(filepath.Clean(f))
 			if err != nil {