1 files changed, 92 insertions, 0 deletions

diff --git a/cli/internal/tarpatch/tar.go b/cli/internal/tarpatch/tar.go
new file mode 100644
index 0000000..a4dab23
--- /dev/null
+++ b/cli/internal/tarpatch/tar.go
@@ -0,0 +1,92 @@
+// Adapted from https://github.com/moby/moby/blob/924edb948c2731df3b77697a8fcc85da3f6eef57/pkg/archive/archive.go
+// Copyright Docker, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package tarpatch addresses an issue with stdlib throwing an error in some environments.
+package tarpatch
+
+import (
+	"archive/tar"
+	"io/fs"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/vercel/turbo/cli/internal/turbopath"
+)
+
+// nosysFileInfo hides the system-dependent info of the wrapped FileInfo to
+// prevent tar.FileInfoHeader from introspecting it and potentially calling into
+// glibc.
+type nosysFileInfo struct {
+	os.FileInfo
+}
+
+func (fi nosysFileInfo) Sys() interface{} {
+	// A Sys value of type *tar.Header is safe as it is system-independent.
+	// The tar.FileInfoHeader function copies the fields into the returned
+	// header without performing any OS lookups.
+	if sys, ok := fi.FileInfo.Sys().(*tar.Header); ok {
+		return sys
+	}
+	return nil
+}
+
+// FileInfoHeaderNoLookups creates a partially-populated tar.Header from fi.
+//
+// Compared to the archive/tar.FileInfoHeader function, this function is safe to
+// call from a chrooted process as it does not populate fields which would
+// require operating system lookups. It behaves identically to
+// tar.FileInfoHeader when fi is a FileInfo value returned from
+// tar.Header.FileInfo().
+//
+// When fi is a FileInfo for a native file, such as returned from os.Stat() and
+// os.Lstat(), the returned Header value differs from one returned from
+// tar.FileInfoHeader in the following ways. The Uname and Gname fields are not
+// set as OS lookups would be required to populate them. The AccessTime and
+// ChangeTime fields are not currently set (not yet implemented) although that
+// is subject to change. Callers which require the AccessTime or ChangeTime
+// fields to be zeroed should explicitly zero them out in the returned Header
+// value to avoid any compatibility issues in the future.
+func FileInfoHeaderNoLookups(fi fs.FileInfo, link string) (*tar.Header, error) {
+	hdr, err := tar.FileInfoHeader(nosysFileInfo{fi}, link)
+	if err != nil {
+		return nil, err
+	}
+	return hdr, sysStat(fi, hdr)
+}
+
+// FileInfoHeader creates a populated Header from fi.
+//
+// Compared to the archive/tar package, this function fills in less information
+// but is safe to call from a chrooted process. The AccessTime and ChangeTime
+// fields are not set in the returned header, ModTime is truncated to one-second
+// precision, and the Uname and Gname fields are only set when fi is a FileInfo
+// value returned from tar.Header.FileInfo().
+func FileInfoHeader(fullPath turbopath.AnchoredUnixPath, fileInfo fs.FileInfo, link string) (*tar.Header, error) {
+	hdr, err := FileInfoHeaderNoLookups(fileInfo, link)
+	if err != nil {
+		return nil, err
+	}
+	hdr.Format = tar.FormatPAX
+	hdr.ModTime = hdr.ModTime.Truncate(time.Second)
+	hdr.AccessTime = time.Time{}
+	hdr.ChangeTime = time.Time{}
+	hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode)))
+	hdr.Name = canonicalTarName(fullPath, fileInfo.IsDir())
+	return hdr, nil
+}
+
+// canonicalTarName provides a platform-independent and consistent posix-style
+// path for files and directories to be archived regardless of the platform.
+func canonicalTarName(fullPath turbopath.AnchoredUnixPath, isDir bool) string {
+	nameString := fullPath.ToString()
+	if isDir {
+		// Append '/' if not already present.
+		if !strings.HasSuffix(nameString, "/") {
+			nameString += "/"
+		}
+	}
+
+	return nameString
+}