moby/pkg/chrootarchive/archive_unix.go
Gabriel Adrian Samfira f49c88f1c4
Disable chrootarchive.init() on Windows
Disables user.Lookup() and net.LookupHost() in the init() function on Windows.

Any package that simply imports pkg/chrootarchive will panic on Windows
Nano Server, due to missing netapi32.dll. While docker itself is not
meant to run on Nano Server, binaries that may import this package and
run on Nano server, will fail even if they don't really use any of the
functionality in this package while running on Nano.

Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>
2023-01-18 16:34:13 +02:00

83 lines
2.1 KiB
Go

//go:build !windows
// +build !windows
package chrootarchive // import "github.com/docker/docker/pkg/chrootarchive"
import (
"io"
"net"
"os/user"
"path/filepath"
"strings"
"github.com/docker/docker/pkg/archive"
"github.com/pkg/errors"
)
func init() {
// initialize nss libraries in Glibc so that the dynamic libraries are loaded in the host
// environment not in the chroot from untrusted files.
_, _ = user.Lookup("docker")
_, _ = net.LookupHost("localhost")
}
func invokeUnpack(decompressedArchive io.Reader, dest string, options *archive.TarOptions, root string) error {
relDest, err := resolvePathInChroot(root, dest)
if err != nil {
return err
}
done := make(chan error)
err = goInChroot(root, func() { done <- archive.Unpack(decompressedArchive, relDest, options) })
if err != nil {
return err
}
return <-done
}
func invokePack(srcPath string, options *archive.TarOptions, root string) (io.ReadCloser, error) {
relSrc, err := resolvePathInChroot(root, srcPath)
if err != nil {
return nil, err
}
// make sure we didn't trim a trailing slash with the call to `resolvePathInChroot`
if strings.HasSuffix(srcPath, "/") && !strings.HasSuffix(relSrc, "/") {
relSrc += "/"
}
tb, err := archive.NewTarballer(relSrc, options)
if err != nil {
return nil, errors.Wrap(err, "error processing tar file")
}
err = goInChroot(root, tb.Do)
if err != nil {
return nil, errors.Wrap(err, "could not chroot")
}
return tb.Reader(), nil
}
// resolvePathInChroot returns the equivalent to path inside a chroot rooted at root.
// The returned path always begins with '/'.
//
// - resolvePathInChroot("/a/b", "/a/b/c/d") -> "/c/d"
// - resolvePathInChroot("/a/b", "/a/b") -> "/"
//
// The implementation is buggy, and some bugs may be load-bearing.
// Here be dragons.
func resolvePathInChroot(root, path string) (string, error) {
if root == "" {
return "", errors.New("root path must not be empty")
}
rel, err := filepath.Rel(root, path)
if err != nil {
return "", err
}
if rel == "." {
rel = "/"
}
if rel[0] != '/' {
rel = "/" + rel
}
return rel, nil
}