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//go:build freebsd
// +build freebsd
package chroot
import (
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"strings"
"syscall"
"github.com/containers/buildah/pkg/jail"
"github.com/containers/storage/pkg/mount"
"github.com/containers/storage/pkg/unshare"
"github.com/opencontainers/runtime-spec/specs-go"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
)
var (
rlimitsMap = map[string]int{
"RLIMIT_AS": unix.RLIMIT_AS,
"RLIMIT_CORE": unix.RLIMIT_CORE,
"RLIMIT_CPU": unix.RLIMIT_CPU,
"RLIMIT_DATA": unix.RLIMIT_DATA,
"RLIMIT_FSIZE": unix.RLIMIT_FSIZE,
"RLIMIT_MEMLOCK": unix.RLIMIT_MEMLOCK,
"RLIMIT_NOFILE": unix.RLIMIT_NOFILE,
"RLIMIT_NPROC": unix.RLIMIT_NPROC,
"RLIMIT_RSS": unix.RLIMIT_RSS,
"RLIMIT_STACK": unix.RLIMIT_STACK,
}
rlimitsReverseMap = map[int]string{}
)
type runUsingChrootSubprocOptions struct {
Spec *specs.Spec
BundlePath string
}
func setPlatformUnshareOptions(spec *specs.Spec, cmd *unshare.Cmd) error {
return nil
}
func setContainerHostname(name string) {
// On FreeBSD, we have to set this later when we create the
// jail below in createPlatformContainer
}
func setSelinuxLabel(spec *specs.Spec) error {
// Ignore this on FreeBSD
return nil
}
func setApparmorProfile(spec *specs.Spec) error {
// FreeBSD doesn't have apparmor`
return nil
}
func setCapabilities(spec *specs.Spec, keepCaps ...string) error {
// FreeBSD capabilities are nothing like Linux
return nil
}
func makeRlimit(limit specs.POSIXRlimit) unix.Rlimit {
return unix.Rlimit{Cur: int64(limit.Soft), Max: int64(limit.Hard)}
}
func createPlatformContainer(options runUsingChrootExecSubprocOptions) error {
path := options.Spec.Root.Path
jconf := jail.NewConfig()
jconf.Set("name", filepath.Base(path)+"-chroot")
jconf.Set("host.hostname", options.Spec.Hostname)
jconf.Set("persist", false)
jconf.Set("path", path)
jconf.Set("ip4", jail.INHERIT)
jconf.Set("ip6", jail.INHERIT)
jconf.Set("allow.raw_sockets", true)
jconf.Set("enforce_statfs", 1)
_, err := jail.CreateAndAttach(jconf)
if err != nil {
return fmt.Errorf("creating jail: %w", err)
}
return nil
}
// logNamespaceDiagnostics knows which namespaces we want to create.
// Output debug messages when that differs from what we're being asked to do.
func logNamespaceDiagnostics(spec *specs.Spec) {
// Nothing here for FreeBSD
}
func makeReadOnly(mntpoint string, flags uintptr) error {
var fs unix.Statfs_t
// Make sure it's read-only.
if err := unix.Statfs(mntpoint, &fs); err != nil {
return fmt.Errorf("checking if directory %q was bound read-only: %w", mntpoint, err)
}
return nil
}
func saveDir(spec *specs.Spec, path string) string {
id := filepath.Base(spec.Root.Path)
return filepath.Join(filepath.Dir(path), ".save-"+id)
}
func copyFile(source, dest string) error {
in, err := os.Open(source)
if err != nil {
return err
}
defer in.Close()
out, err := os.Create(dest)
if err != nil {
return err
}
defer out.Close()
_, err = io.Copy(out, in)
if err != nil {
return err
}
return out.Close()
}
type rename struct {
from, to string
}
// setupChrootBindMounts actually bind mounts things under the rootfs, and returns a
// callback that will clean up its work.
func setupChrootBindMounts(spec *specs.Spec, bundlePath string) (undoBinds func() error, err error) {
renames := []rename{}
unmounts := []string{}
removes := []string{}
undoBinds = func() error {
for _, r := range renames {
if err2 := os.Rename(r.to, r.from); err2 != nil {
logrus.Warnf("pkg/chroot: error renaming %q to %q: %v", r.to, r.from, err2)
if err == nil {
err = err2
}
}
}
for _, path := range unmounts {
if err2 := mount.Unmount(path); err2 != nil {
logrus.Warnf("pkg/chroot: error unmounting %q: %v", spec.Root.Path, err2)
if err == nil {
err = err2
}
}
}
for _, path := range removes {
if err2 := os.Remove(path); err2 != nil {
logrus.Warnf("pkg/chroot: error removing %q: %v", path, err2)
if err == nil {
err = err2
}
}
}
return err
}
// Now mount all of those things to be under the rootfs's location in this
// mount namespace.
for _, m := range spec.Mounts {
// If the target is there, we can just mount it.
var srcinfo os.FileInfo
switch m.Type {
case "nullfs":
srcinfo, err = os.Stat(m.Source)
if err != nil {
return undoBinds, fmt.Errorf("examining %q for mounting in mount namespace: %w", m.Source, err)
}
}
target := filepath.Join(spec.Root.Path, m.Destination)
if _, err := os.Stat(target); err != nil {
// If the target can't be stat()ted, check the error.
if !os.IsNotExist(err) {
return undoBinds, fmt.Errorf("examining %q for mounting in mount namespace: %w", target, err)
}
// The target isn't there yet, so create it, and make a
// note to remove it later.
// XXX: This was copied from the linux version which supports bind mounting files.
// Leaving it here since I plan to add this to FreeBSD's nullfs.
if m.Type != "nullfs" || srcinfo.IsDir() {
if err = os.MkdirAll(target, 0111); err != nil {
return undoBinds, fmt.Errorf("creating mountpoint %q in mount namespace: %w", target, err)
}
removes = append(removes, target)
} else {
if err = os.MkdirAll(filepath.Dir(target), 0111); err != nil {
return undoBinds, fmt.Errorf("ensuring parent of mountpoint %q (%q) is present in mount namespace: %w", target, filepath.Dir(target), err)
}
// Don't do this until we can support file mounts in nullfs
/*var file *os.File
if file, err = os.OpenFile(target, os.O_WRONLY|os.O_CREATE, 0); err != nil {
return undoBinds, errors.Wrapf(err, "error creating mountpoint %q in mount namespace", target)
}
file.Close()
removes = append(removes, target)*/
}
}
logrus.Debugf("mount: %v", m)
switch m.Type {
case "nullfs":
// Do the bind mount.
if !srcinfo.IsDir() {
logrus.Debugf("emulating file mount %q on %q", m.Source, target)
_, err := os.Stat(target)
if err == nil {
save := saveDir(spec, target)
if _, err := os.Stat(save); err != nil {
if os.IsNotExist(err) {
err = os.MkdirAll(save, 0111)
}
if err != nil {
return undoBinds, fmt.Errorf("creating file mount save directory %q: %w", save, err)
}
removes = append(removes, save)
}
savePath := filepath.Join(save, filepath.Base(target))
if _, err := os.Stat(target); err == nil {
logrus.Debugf("moving %q to %q", target, savePath)
if err := os.Rename(target, savePath); err != nil {
return undoBinds, fmt.Errorf("moving %q to %q: %w", target, savePath, err)
}
renames = append(renames, rename{
from: target,
to: savePath,
})
}
} else {
removes = append(removes, target)
}
if err := copyFile(m.Source, target); err != nil {
return undoBinds, fmt.Errorf("copying %q to %q: %w", m.Source, target, err)
}
} else {
logrus.Debugf("bind mounting %q on %q", m.Destination, filepath.Join(spec.Root.Path, m.Destination))
if err := mount.Mount(m.Source, target, "nullfs", strings.Join(m.Options, ",")); err != nil {
return undoBinds, fmt.Errorf("bind mounting %q from host to %q in mount namespace (%q): %w", m.Source, m.Destination, target, err)
}
logrus.Debugf("bind mounted %q to %q", m.Source, target)
unmounts = append(unmounts, target)
}
case "devfs", "fdescfs", "tmpfs":
// Mount /dev, /dev/fd.
if err := mount.Mount(m.Source, target, m.Type, strings.Join(m.Options, ",")); err != nil {
return undoBinds, fmt.Errorf("mounting %q to %q in mount namespace (%q, %q): %w", m.Type, m.Destination, target, strings.Join(m.Options, ","), err)
}
logrus.Debugf("mounted a %q to %q", m.Type, target)
unmounts = append(unmounts, target)
}
}
return undoBinds, nil
}
// setPdeathsig sets a parent-death signal for the process
func setPdeathsig(cmd *exec.Cmd) {
if cmd.SysProcAttr == nil {
cmd.SysProcAttr = &syscall.SysProcAttr{}
}
cmd.SysProcAttr.Pdeathsig = syscall.SIGKILL
}
|
