blob: b6c2495e9ffadd69eaddf2ef4734fa48db784e75 [file] [log] [blame]
// +build selinux,linux
package label
import (
"fmt"
"strings"
"github.com/opencontainers/runc/libcontainer/selinux"
)
// Valid Label Options
var validOptions = map[string]bool{
"disable": true,
"type": true,
"user": true,
"role": true,
"level": true,
}
var ErrIncompatibleLabel = fmt.Errorf("Bad SELinux option z and Z can not be used together")
// InitLabels returns the process label and file labels to be used within
// the container. A list of options can be passed into this function to alter
// the labels. The labels returned will include a random MCS String, that is
// guaranteed to be unique.
func InitLabels(options []string) (string, string, error) {
if !selinux.SelinuxEnabled() {
return "", "", nil
}
processLabel, mountLabel := selinux.GetLxcContexts()
if processLabel != "" {
pcon := selinux.NewContext(processLabel)
mcon := selinux.NewContext(mountLabel)
for _, opt := range options {
if opt == "disable" {
return "", "", nil
}
if i := strings.Index(opt, ":"); i == -1 {
return "", "", fmt.Errorf("Bad label option %q, valid options 'disable' or \n'user, role, level, type' followed by ':' and a value", opt)
}
con := strings.SplitN(opt, ":", 2)
if !validOptions[con[0]] {
return "", "", fmt.Errorf("Bad label option %q, valid options 'disable, user, role, level, type'", con[0])
}
pcon[con[0]] = con[1]
if con[0] == "level" || con[0] == "user" {
mcon[con[0]] = con[1]
}
}
processLabel = pcon.Get()
mountLabel = mcon.Get()
}
return processLabel, mountLabel, nil
}
func GetROMountLabel() string {
return selinux.GetROFileLabel()
}
// DEPRECATED: The GenLabels function is only to be used during the transition to the official API.
func GenLabels(options string) (string, string, error) {
return InitLabels(strings.Fields(options))
}
// FormatMountLabel returns a string to be used by the mount command.
// The format of this string will be used to alter the labeling of the mountpoint.
// The string returned is suitable to be used as the options field of the mount command.
// If you need to have additional mount point options, you can pass them in as
// the first parameter. Second parameter is the label that you wish to apply
// to all content in the mount point.
func FormatMountLabel(src, mountLabel string) string {
if mountLabel != "" {
switch src {
case "":
src = fmt.Sprintf("context=%q", mountLabel)
default:
src = fmt.Sprintf("%s,context=%q", src, mountLabel)
}
}
return src
}
// SetProcessLabel takes a process label and tells the kernel to assign the
// label to the next program executed by the current process.
func SetProcessLabel(processLabel string) error {
if processLabel == "" {
return nil
}
return selinux.Setexeccon(processLabel)
}
// GetProcessLabel returns the process label that the kernel will assign
// to the next program executed by the current process. If "" is returned
// this indicates that the default labeling will happen for the process.
func GetProcessLabel() (string, error) {
return selinux.Getexeccon()
}
// GetFileLabel returns the label for specified path
func GetFileLabel(path string) (string, error) {
return selinux.Getfilecon(path)
}
// SetFileLabel modifies the "path" label to the specified file label
func SetFileLabel(path string, fileLabel string) error {
if selinux.SelinuxEnabled() && fileLabel != "" {
return selinux.Setfilecon(path, fileLabel)
}
return nil
}
// SetFileCreateLabel tells the kernel the label for all files to be created
func SetFileCreateLabel(fileLabel string) error {
if selinux.SelinuxEnabled() {
return selinux.Setfscreatecon(fileLabel)
}
return nil
}
// Relabel changes the label of path to the filelabel string.
// It changes the MCS label to s0 if shared is true.
// This will allow all containers to share the content.
func Relabel(path string, fileLabel string, shared bool) error {
if !selinux.SelinuxEnabled() {
return nil
}
if fileLabel == "" {
return nil
}
exclude_paths := map[string]bool{"/": true, "/usr": true, "/etc": true}
if exclude_paths[path] {
return fmt.Errorf("SELinux relabeling of %s is not allowed", path)
}
if shared {
c := selinux.NewContext(fileLabel)
c["level"] = "s0"
fileLabel = c.Get()
}
if err := selinux.Chcon(path, fileLabel, true); err != nil {
return fmt.Errorf("SELinux relabeling of %s is not allowed: %q", path, err)
}
return nil
}
// GetPidLabel will return the label of the process running with the specified pid
func GetPidLabel(pid int) (string, error) {
return selinux.Getpidcon(pid)
}
// Init initialises the labeling system
func Init() {
selinux.SelinuxEnabled()
}
// ReserveLabel will record the fact that the MCS label has already been used.
// This will prevent InitLabels from using the MCS label in a newly created
// container
func ReserveLabel(label string) error {
selinux.ReserveLabel(label)
return nil
}
// UnreserveLabel will remove the reservation of the MCS label.
// This will allow InitLabels to use the MCS label in a newly created
// containers
func UnreserveLabel(label string) error {
selinux.FreeLxcContexts(label)
return nil
}
// DupSecOpt takes an process label and returns security options that
// can be used to set duplicate labels on future container processes
func DupSecOpt(src string) []string {
return selinux.DupSecOpt(src)
}
// DisableSecOpt returns a security opt that can disable labeling
// support for future container processes
func DisableSecOpt() []string {
return selinux.DisableSecOpt()
}
// Validate checks that the label does not include unexpected options
func Validate(label string) error {
if strings.Contains(label, "z") && strings.Contains(label, "Z") {
return ErrIncompatibleLabel
}
return nil
}
// RelabelNeeded checks whether the user requested a relabel
func RelabelNeeded(label string) bool {
return strings.Contains(label, "z") || strings.Contains(label, "Z")
}
// IsShared checks that the label includes a "shared" mark
func IsShared(label string) bool {
return strings.Contains(label, "z")
}