Vendor in opencontainers/selinux

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/opencontainers/selinux/go-selinux/label/label.go

@@ -0,0 +1,84 @@
+// +build !selinux !linux
+
+package label
+
+// 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.
+func InitLabels(options []string) (string, string, error) {
+	return "", "", nil
+}
+
+func GetROMountLabel() string {
+	return ""
+}
+
+func GenLabels(options string) (string, string, error) {
+	return "", "", nil
+}
+
+func FormatMountLabel(src string, mountLabel string) string {
+	return src
+}
+
+func SetProcessLabel(processLabel string) error {
+	return nil
+}
+
+func GetFileLabel(path string) (string, error) {
+	return "", nil
+}
+
+func SetFileLabel(path string, fileLabel string) error {
+	return nil
+}
+
+func SetFileCreateLabel(fileLabel string) error {
+	return nil
+}
+
+func Relabel(path string, fileLabel string, shared bool) error {
+	return nil
+}
+
+func GetPidLabel(pid int) (string, error) {
+	return "", nil
+}
+
+func Init() {
+}
+
+func ReserveLabel(label string) error {
+	return nil
+}
+
+func ReleaseLabel(label string) error {
+	return nil
+}
+
+// DupSecOpt takes a process label and returns security options that
+// can be used to set duplicate labels on future container processes
+func DupSecOpt(src string) []string {
+	return nil
+}
+
+// DisableSecOpt returns a security opt that can disable labeling
+// support for future container processes
+func DisableSecOpt() []string {
+	return nil
+}
+
+// Validate checks that the label does not include unexpected options
+func Validate(label string) error {
+	return nil
+}
+
+// RelabelNeeded checks whether the user requested a relabel
+func RelabelNeeded(label string) bool {
+	return false
+}
+
+// IsShared checks that the label includes a "shared" mark
+func IsShared(label string) bool {
+	return false
+}

vendor/github.com/opencontainers/selinux/go-selinux/label/label_selinux.go

@@ -0,0 +1,204 @@
+// +build selinux,linux
+
+package label
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/opencontainers/selinux/go-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.GetEnabled() {
+		return "", "", nil
+	}
+	processLabel, mountLabel := selinux.ContainerLabels()
+	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 ROMountLabel() string {
+	return selinux.ROFileLabel()
+}
+
+// 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.SetExecLabel(processLabel)
+}
+
+// ProcessLabel 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 ProcessLabel() (string, error) {
+	return selinux.ExecLabel()
+}
+
+// GetFileLabel returns the label for specified path
+func FileLabel(path string) (string, error) {
+	return selinux.FileLabel(path)
+}
+
+// SetFileLabel modifies the "path" label to the specified file label
+func SetFileLabel(path string, fileLabel string) error {
+	if selinux.GetEnabled() && fileLabel != "" {
+		return selinux.SetFileLabel(path, fileLabel)
+	}
+	return nil
+}
+
+// SetFileCreateLabel tells the kernel the label for all files to be created
+func SetFileCreateLabel(fileLabel string) error {
+	if selinux.GetEnabled() {
+		return selinux.SetFSCreateLabel(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.GetEnabled() {
+		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 err
+	}
+	return nil
+}
+
+// PidLabel will return the label of the process running with the specified pid
+func PidLabel(pid int) (string, error) {
+	return selinux.PidLabel(pid)
+}
+
+// Init initialises the labeling system
+func Init() {
+	selinux.GetEnabled()
+}
+
+// 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
+}
+
+// ReleaseLabel will remove the reservation of the MCS label.
+// This will allow InitLabels to use the MCS label in a newly created
+// containers
+func ReleaseLabel(label string) error {
+	selinux.ReleaseLabel(label)
+	return nil
+}
+
+// DupSecOpt takes a 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")
+}

vendor/github.com/opencontainers/selinux/go-selinux/label/label_selinux_test.go

@@ -0,0 +1,146 @@
+// +build selinux,linux
+
+package label
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/opencontainers/selinux/go-selinux"
+)
+
+func TestInit(t *testing.T) {
+	if !selinux.GetEnabled() {
+		return
+	}
+	var testNull []string
+	plabel, mlabel, err := InitLabels(testNull)
+	if err != nil {
+		t.Log("InitLabels Failed")
+		t.Fatal(err)
+	}
+	testDisabled := []string{"disable"}
+	roMountLabel := ROMountLabel()
+	if roMountLabel == "" {
+		t.Errorf("ROMountLabel Failed")
+	}
+	plabel, mlabel, err = InitLabels(testDisabled)
+	if err != nil {
+		t.Log("InitLabels Disabled Failed")
+		t.Fatal(err)
+	}
+	if plabel != "" {
+		t.Log("InitLabels Disabled Failed")
+		t.FailNow()
+	}
+	testUser := []string{"user:user_u", "role:user_r", "type:user_t", "level:s0:c1,c15"}
+	plabel, mlabel, err = InitLabels(testUser)
+	if err != nil {
+		t.Log("InitLabels User Failed")
+		t.Fatal(err)
+	}
+	if plabel != "user_u:user_r:user_t:s0:c1,c15" || (mlabel != "user_u:object_r:container_file_t:s0:c1,c15" && mlabel != "user_u:object_r:svirt_sandbox_file_t:s0:c1,c15") {
+		t.Log("InitLabels User Match Failed")
+		t.Log(plabel, mlabel)
+		t.Fatal(err)
+	}
+
+	testBadData := []string{"user", "role:user_r", "type:user_t", "level:s0:c1,c15"}
+	if _, _, err = InitLabels(testBadData); err == nil {
+		t.Log("InitLabels Bad Failed")
+		t.Fatal(err)
+	}
+}
+func TestDuplicateLabel(t *testing.T) {
+	secopt := DupSecOpt("system_u:system_r:container_t:s0:c1,c2")
+	for _, opt := range secopt {
+		con := strings.SplitN(opt, ":", 2)
+		if con[0] == "user" {
+			if con[1] != "system_u" {
+				t.Errorf("DupSecOpt Failed user incorrect")
+			}
+			continue
+		}
+		if con[0] == "role" {
+			if con[1] != "system_r" {
+				t.Errorf("DupSecOpt Failed role incorrect")
+			}
+			continue
+		}
+		if con[0] == "type" {
+			if con[1] != "container_t" {
+				t.Errorf("DupSecOpt Failed type incorrect")
+			}
+			continue
+		}
+		if con[0] == "level" {
+			if con[1] != "s0:c1,c2" {
+				t.Errorf("DupSecOpt Failed level incorrect")
+			}
+			continue
+		}
+		t.Errorf("DupSecOpt Failed invalid field %q", con[0])
+	}
+	secopt = DisableSecOpt()
+	if secopt[0] != "disable" {
+		t.Errorf("DisableSecOpt Failed level incorrect %q", secopt[0])
+	}
+}
+func TestRelabel(t *testing.T) {
+	if !selinux.GetEnabled() {
+		return
+	}
+	testdir := "/tmp/test"
+	if err := os.Mkdir(testdir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(testdir)
+	label := "system_u:object_r:container_file_t:s0:c1,c2"
+	if err := Relabel(testdir, "", true); err != nil {
+		t.Fatalf("Relabel with no label failed: %v", err)
+	}
+	if err := Relabel(testdir, label, true); err != nil {
+		t.Fatalf("Relabel shared failed: %v", err)
+	}
+	if err := Relabel(testdir, label, false); err != nil {
+		t.Fatalf("Relabel unshared failed: %v", err)
+	}
+	if err := Relabel("/etc", label, false); err == nil {
+		t.Fatalf("Relabel /etc succeeded")
+	}
+	if err := Relabel("/", label, false); err == nil {
+		t.Fatalf("Relabel / succeeded")
+	}
+	if err := Relabel("/usr", label, false); err == nil {
+		t.Fatalf("Relabel /usr succeeded")
+	}
+}
+
+func TestValidate(t *testing.T) {
+	if err := Validate("zZ"); err != ErrIncompatibleLabel {
+		t.Fatalf("Expected incompatible error, got %v", err)
+	}
+	if err := Validate("Z"); err != nil {
+		t.Fatal(err)
+	}
+	if err := Validate("z"); err != nil {
+		t.Fatal(err)
+	}
+	if err := Validate(""); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestIsShared(t *testing.T) {
+	if shared := IsShared("Z"); shared {
+		t.Fatalf("Expected label `Z` to not be shared, got %v", shared)
+	}
+	if shared := IsShared("z"); !shared {
+		t.Fatalf("Expected label `z` to be shared, got %v", shared)
+	}
+	if shared := IsShared("Zz"); !shared {
+		t.Fatalf("Expected label `Zz` to be shared, got %v", shared)
+	}
+
+}

vendor/github.com/opencontainers/selinux/go-selinux/selinux.go

@@ -0,0 +1,593 @@
+// +build linux
+
+package selinux
+
+import (
+	"bufio"
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+)
+
+const (
+	// Enforcing constant indicate SELinux is in enforcing mode
+	Enforcing = 1
+	// Permissive constant to indicate SELinux is in permissive mode
+	Permissive = 0
+	// Disabled constant to indicate SELinux is disabled
+	Disabled         = -1
+	selinuxDir       = "/etc/selinux/"
+	selinuxConfig    = selinuxDir + "config"
+	selinuxTypeTag   = "SELINUXTYPE"
+	selinuxTag       = "SELINUX"
+	selinuxPath      = "/sys/fs/selinux"
+	xattrNameSelinux = "security.selinux"
+	stRdOnly         = 0x01
+)
+
+type selinuxState struct {
+	enabledSet   bool
+	enabled      bool
+	selinuxfsSet bool
+	selinuxfs    string
+	mcsList      map[string]bool
+	sync.Mutex
+}
+
+var (
+	assignRegex = regexp.MustCompile(`^([^=]+)=(.*)$`)
+	state       = selinuxState{
+		mcsList: make(map[string]bool),
+	}
+)
+
+// Context is a representation of the SELinux label broken into 4 parts
+type Context map[string]string
+
+func (s *selinuxState) setEnable(enabled bool) bool {
+	s.Lock()
+	defer s.Unlock()
+	s.enabledSet = true
+	s.enabled = enabled
+	return s.enabled
+}
+
+func (s *selinuxState) getEnabled() bool {
+	s.Lock()
+	enabled := s.enabled
+	enabledSet := s.enabledSet
+	s.Unlock()
+	if enabledSet {
+		return enabled
+	}
+
+	enabled = false
+	if fs := getSelinuxMountPoint(); fs != "" {
+		if con, _ := CurrentLabel(); con != "kernel" {
+			enabled = true
+		}
+	}
+	return s.setEnable(enabled)
+}
+
+// SetDisabled disables selinux support for the package
+func SetDisabled() {
+	state.setEnable(false)
+}
+
+func (s *selinuxState) setSELinuxfs(selinuxfs string) string {
+	s.Lock()
+	defer s.Unlock()
+	s.selinuxfsSet = true
+	s.selinuxfs = selinuxfs
+	return s.selinuxfs
+}
+
+func (s *selinuxState) getSELinuxfs() string {
+	s.Lock()
+	selinuxfs := s.selinuxfs
+	selinuxfsSet := s.selinuxfsSet
+	s.Unlock()
+	if selinuxfsSet {
+		return selinuxfs
+	}
+
+	selinuxfs = ""
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return selinuxfs
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		txt := scanner.Text()
+		// Safe as mountinfo encodes mountpoints with spaces as \040.
+		sepIdx := strings.Index(txt, " - ")
+		if sepIdx == -1 {
+			continue
+		}
+		if !strings.Contains(txt[sepIdx:], "selinuxfs") {
+			continue
+		}
+		fields := strings.Split(txt, " ")
+		if len(fields) < 5 {
+			continue
+		}
+		selinuxfs = fields[4]
+		break
+	}
+
+	if selinuxfs != "" {
+		var buf syscall.Statfs_t
+		syscall.Statfs(selinuxfs, &buf)
+		if (buf.Flags & stRdOnly) == 1 {
+			selinuxfs = ""
+		}
+	}
+	return s.setSELinuxfs(selinuxfs)
+}
+
+// getSelinuxMountPoint returns the path to the mountpoint of an selinuxfs
+// filesystem or an empty string if no mountpoint is found.  Selinuxfs is
+// a proc-like pseudo-filesystem that exposes the selinux policy API to
+// processes.  The existence of an selinuxfs mount is used to determine
+// whether selinux is currently enabled or not.
+func getSelinuxMountPoint() string {
+	return state.getSELinuxfs()
+}
+
+// GetEnabled returns whether selinux is currently enabled.
+func GetEnabled() bool {
+	return state.getEnabled()
+}
+
+func readConfig(target string) (value string) {
+	var (
+		val, key string
+		bufin    *bufio.Reader
+	)
+
+	in, err := os.Open(selinuxConfig)
+	if err != nil {
+		return ""
+	}
+	defer in.Close()
+
+	bufin = bufio.NewReader(in)
+
+	for done := false; !done; {
+		var line string
+		if line, err = bufin.ReadString('\n'); err != nil {
+			if err != io.EOF {
+				return ""
+			}
+			done = true
+		}
+		line = strings.TrimSpace(line)
+		if len(line) == 0 {
+			// Skip blank lines
+			continue
+		}
+		if line[0] == ';' || line[0] == '#' {
+			// Skip comments
+			continue
+		}
+		if groups := assignRegex.FindStringSubmatch(line); groups != nil {
+			key, val = strings.TrimSpace(groups[1]), strings.TrimSpace(groups[2])
+			if key == target {
+				return strings.Trim(val, "\"")
+			}
+		}
+	}
+	return ""
+}
+
+func getSELinuxPolicyRoot() string {
+	return selinuxDir + readConfig(selinuxTypeTag)
+}
+
+func readCon(name string) (string, error) {
+	var val string
+
+	in, err := os.Open(name)
+	if err != nil {
+		return "", err
+	}
+	defer in.Close()
+
+	_, err = fmt.Fscanf(in, "%s", &val)
+	return val, err
+}
+
+// SetFileLabel sets the SELinux label for this path or returns an error.
+func SetFileLabel(path string, label string) error {
+	return lsetxattr(path, xattrNameSelinux, []byte(label), 0)
+}
+
+// Filecon returns the SELinux label for this path or returns an error.
+func FileLabel(path string) (string, error) {
+	label, err := lgetxattr(path, xattrNameSelinux)
+	if err != nil {
+		return "", err
+	}
+	// Trim the NUL byte at the end of the byte buffer, if present.
+	if len(label) > 0 && label[len(label)-1] == '\x00' {
+		label = label[:len(label)-1]
+	}
+	return string(label), nil
+}
+
+/*
+SetFSCreateLabel tells kernel the label to create all file system objects
+created by this task. Setting label="" to return to default.
+*/
+func SetFSCreateLabel(label string) error {
+	return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/fscreate", syscall.Gettid()), label)
+}
+
+/*
+FSCreateLabel returns the default label the kernel which the kernel is using
+for file system objects created by this task. "" indicates default.
+*/
+func FSCreateLabel() (string, error) {
+	return readCon(fmt.Sprintf("/proc/self/task/%d/attr/fscreate", syscall.Gettid()))
+}
+
+// CurrentLabel returns the SELinux label of the current process thread, or an error.
+func CurrentLabel() (string, error) {
+	return readCon(fmt.Sprintf("/proc/self/task/%d/attr/current", syscall.Gettid()))
+}
+
+// PidLabel returns the SELinux label of the given pid, or an error.
+func PidLabel(pid int) (string, error) {
+	return readCon(fmt.Sprintf("/proc/%d/attr/current", pid))
+}
+
+/*
+ExecLabel returns the SELinux label that the kernel will use for any programs
+that are executed by the current process thread, or an error.
+*/
+func ExecLabel() (string, error) {
+	return readCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()))
+}
+
+func writeCon(name string, val string) error {
+	out, err := os.OpenFile(name, os.O_WRONLY, 0)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	if val != "" {
+		_, err = out.Write([]byte(val))
+	} else {
+		_, err = out.Write(nil)
+	}
+	return err
+}
+
+/*
+SetExecLabel sets the SELinux label that the kernel will use for any programs
+that are executed by the current process thread, or an error.
+*/
+func SetExecLabel(label string) error {
+	return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()), label)
+}
+
+// Get returns the Context as a string
+func (c Context) Get() string {
+	return fmt.Sprintf("%s:%s:%s:%s", c["user"], c["role"], c["type"], c["level"])
+}
+
+// NewContext creates a new Context struct from the specified label
+func NewContext(label string) Context {
+	c := make(Context)
+
+	if len(label) != 0 {
+		con := strings.SplitN(label, ":", 4)
+		c["user"] = con[0]
+		c["role"] = con[1]
+		c["type"] = con[2]
+		c["level"] = con[3]
+	}
+	return c
+}
+
+// ReserveLabel reserves the MLS/MCS level component of the specified label
+func ReserveLabel(label string) {
+	if len(label) != 0 {
+		con := strings.SplitN(label, ":", 4)
+		mcsAdd(con[3])
+	}
+}
+
+func selinuxEnforcePath() string {
+	return fmt.Sprintf("%s/enforce", selinuxPath)
+}
+
+// EnforceMode returns the current SELinux mode Enforcing, Permissive, Disabled
+func EnforceMode() int {
+	var enforce int
+
+	enforceS, err := readCon(selinuxEnforcePath())
+	if err != nil {
+		return -1
+	}
+
+	enforce, err = strconv.Atoi(string(enforceS))
+	if err != nil {
+		return -1
+	}
+	return enforce
+}
+
+/*
+SetEnforce sets the current SELinux mode Enforcing, Permissive.
+Disabled is not valid, since this needs to be set at boot time.
+*/
+func SetEnforceMode(mode int) error {
+	return writeCon(selinuxEnforcePath(), fmt.Sprintf("%d", mode))
+}
+
+/*
+DefaultEnforceMode returns the systems default SELinux mode Enforcing,
+Permissive or Disabled. Note this is is just the default at boot time.
+EnforceMode tells you the systems current mode.
+*/
+func DefaultEnforceMode() int {
+	switch readConfig(selinuxTag) {
+	case "enforcing":
+		return Enforcing
+	case "permissive":
+		return Permissive
+	}
+	return Disabled
+}
+
+func mcsAdd(mcs string) error {
+	state.Lock()
+	defer state.Unlock()
+	if state.mcsList[mcs] {
+		return fmt.Errorf("MCS Label already exists")
+	}
+	state.mcsList[mcs] = true
+	return nil
+}
+
+func mcsDelete(mcs string) {
+	state.Lock()
+	defer state.Unlock()
+	state.mcsList[mcs] = false
+}
+
+func intToMcs(id int, catRange uint32) string {
+	var (
+		SETSIZE = int(catRange)
+		TIER    = SETSIZE
+		ORD     = id
+	)
+
+	if id < 1 || id > 523776 {
+		return ""
+	}
+
+	for ORD > TIER {
+		ORD = ORD - TIER
+		TIER--
+	}
+	TIER = SETSIZE - TIER
+	ORD = ORD + TIER
+	return fmt.Sprintf("s0:c%d,c%d", TIER, ORD)
+}
+
+func uniqMcs(catRange uint32) string {
+	var (
+		n      uint32
+		c1, c2 uint32
+		mcs    string
+	)
+
+	for {
+		binary.Read(rand.Reader, binary.LittleEndian, &n)
+		c1 = n % catRange
+		binary.Read(rand.Reader, binary.LittleEndian, &n)
+		c2 = n % catRange
+		if c1 == c2 {
+			continue
+		} else {
+			if c1 > c2 {
+				c1, c2 = c2, c1
+			}
+		}
+		mcs = fmt.Sprintf("s0:c%d,c%d", c1, c2)
+		if err := mcsAdd(mcs); err != nil {
+			continue
+		}
+		break
+	}
+	return mcs
+}
+
+/*
+ReleaseLabel will unreserve the MLS/MCS Level field of the specified label.
+Allowing it to be used by another process.
+*/
+func ReleaseLabel(label string) {
+	if len(label) != 0 {
+		con := strings.SplitN(label, ":", 4)
+		mcsDelete(con[3])
+	}
+}
+
+var roFileLabel string
+
+// ROFileLabel returns the specified SELinux readonly file label
+func ROFileLabel() (fileLabel string) {
+	return roFileLabel
+}
+
+/*
+ContainerLabels returns an allocated processLabel and fileLabel to be used for
+container labeling by the calling process.
+*/
+func ContainerLabels() (processLabel string, fileLabel string) {
+	var (
+		val, key string
+		bufin    *bufio.Reader
+	)
+
+	if !GetEnabled() {
+		return "", ""
+	}
+	lxcPath := fmt.Sprintf("%s/contexts/lxc_contexts", getSELinuxPolicyRoot())
+	in, err := os.Open(lxcPath)
+	if err != nil {
+		return "", ""
+	}
+	defer in.Close()
+
+	bufin = bufio.NewReader(in)
+
+	for done := false; !done; {
+		var line string
+		if line, err = bufin.ReadString('\n'); err != nil {
+			if err == io.EOF {
+				done = true
+			} else {
+				goto exit
+			}
+		}
+		line = strings.TrimSpace(line)
+		if len(line) == 0 {
+			// Skip blank lines
+			continue
+		}
+		if line[0] == ';' || line[0] == '#' {
+			// Skip comments
+			continue
+		}
+		if groups := assignRegex.FindStringSubmatch(line); groups != nil {
+			key, val = strings.TrimSpace(groups[1]), strings.TrimSpace(groups[2])
+			if key == "process" {
+				processLabel = strings.Trim(val, "\"")
+			}
+			if key == "file" {
+				fileLabel = strings.Trim(val, "\"")
+			}
+			if key == "ro_file" {
+				roFileLabel = strings.Trim(val, "\"")
+			}
+		}
+	}
+
+	if processLabel == "" || fileLabel == "" {
+		return "", ""
+	}
+
+	if roFileLabel == "" {
+		roFileLabel = fileLabel
+	}
+exit:
+	mcs := uniqMcs(1024)
+	scon := NewContext(processLabel)
+	scon["level"] = mcs
+	processLabel = scon.Get()
+	scon = NewContext(fileLabel)
+	scon["level"] = mcs
+	fileLabel = scon.Get()
+	return processLabel, fileLabel
+}
+
+// SecurityCheckContext validates that the SELinux label is understood by the kernel
+func SecurityCheckContext(val string) error {
+	return writeCon(fmt.Sprintf("%s.context", selinuxPath), val)
+}
+
+/*
+CopyLevel returns a label with the MLS/MCS level from src label replaces on
+the dest label.
+*/
+func CopyLevel(src, dest string) (string, error) {
+	if src == "" {
+		return "", nil
+	}
+	if err := SecurityCheckContext(src); err != nil {
+		return "", err
+	}
+	if err := SecurityCheckContext(dest); err != nil {
+		return "", err
+	}
+	scon := NewContext(src)
+	tcon := NewContext(dest)
+	mcsDelete(tcon["level"])
+	mcsAdd(scon["level"])
+	tcon["level"] = scon["level"]
+	return tcon.Get(), nil
+}
+
+// Prevent users from relabing system files
+func badPrefix(fpath string) error {
+	var badprefixes = []string{"/usr"}
+
+	for _, prefix := range badprefixes {
+		if fpath == prefix || strings.HasPrefix(fpath, fmt.Sprintf("%s/", prefix)) {
+			return fmt.Errorf("relabeling content in %s is not allowed", prefix)
+		}
+	}
+	return nil
+}
+
+// Chcon changes the fpath file object to the SELinux label label.
+// If the fpath is a directory and recurse is true Chcon will walk the
+// directory tree setting the label
+func Chcon(fpath string, label string, recurse bool) error {
+	if label == "" {
+		return nil
+	}
+	if err := badPrefix(fpath); err != nil {
+		return err
+	}
+	callback := func(p string, info os.FileInfo, err error) error {
+		return SetFileLabel(p, label)
+	}
+
+	if recurse {
+		return filepath.Walk(fpath, callback)
+	}
+
+	return SetFileLabel(fpath, label)
+}
+
+// DupSecOpt takes an SELinux process label and returns security options that
+// can will set the SELinux Type and Level for future container processes
+func DupSecOpt(src string) []string {
+	if src == "" {
+		return nil
+	}
+	con := NewContext(src)
+	if con["user"] == "" ||
+		con["role"] == "" ||
+		con["type"] == "" ||
+		con["level"] == "" {
+		return nil
+	}
+	return []string{"user:" + con["user"],
+		"role:" + con["role"],
+		"type:" + con["type"],
+		"level:" + con["level"]}
+}
+
+// DisableSecOpt returns a security opt that can be used to disabling SELinux
+// labeling support for future container processes
+func DisableSecOpt() []string {
+	return []string{"disable"}
+}

vendor/github.com/opencontainers/selinux/go-selinux/selinux_test.go

@@ -0,0 +1,81 @@
+// +build linux,selinux
+
+package selinux
+
+import (
+	"os"
+	"testing"
+)
+
+func TestSetFileLabel(t *testing.T) {
+	if GetEnabled() {
+		tmp := "selinux_test"
+		con := "system_u:object_r:bin_t:s0"
+		out, _ := os.OpenFile(tmp, os.O_WRONLY|os.O_CREATE, 0)
+		out.Close()
+		err := SetFileLabel(tmp, con)
+		if err != nil {
+			t.Log("Setfilecon failed")
+			t.Fatal(err)
+		}
+		filelabel, err := FileLabel(tmp)
+		if err != nil {
+			t.Log("FileLabel failed")
+			t.Fatal(err)
+		}
+		if con != filelabel {
+			t.Fatal("FileLabel failed, returned %s expected %s", filelabel, con)
+		}
+
+		os.Remove(tmp)
+	}
+}
+
+func TestSELinux(t *testing.T) {
+	var (
+		err            error
+		plabel, flabel string
+	)
+
+	if GetEnabled() {
+		t.Log("Enabled")
+		plabel, flabel = ContainerLabels()
+		t.Log(plabel)
+		t.Log(flabel)
+		ReleaseLabel(plabel)
+		plabel, flabel = ContainerLabels()
+		t.Log(plabel)
+		t.Log(flabel)
+		ReleaseLabel(plabel)
+		t.Log("Enforcing Mode", EnforceMode())
+		mode := DefaultEnforceMode()
+		t.Log("Default Enforce Mode ", mode)
+
+		defer SetEnforceMode(mode)
+		if err := SetEnforceMode(Enforcing); err != nil {
+			t.Fatalf("enforcing selinux failed: %v", err)
+		}
+		if err := SetEnforceMode(Permissive); err != nil {
+			t.Fatalf("setting selinux mode to permissive failed: %v", err)
+		}
+		SetEnforceMode(mode)
+
+		pid := os.Getpid()
+		t.Logf("PID:%d MCS:%s\n", pid, intToMcs(pid, 1023))
+		err = SetFSCreateLabel("unconfined_u:unconfined_r:unconfined_t:s0")
+		if err == nil {
+			t.Log(FSCreateLabel())
+		} else {
+			t.Log("SetFSCreateLabel failed", err)
+			t.Fatal(err)
+		}
+		err = SetFSCreateLabel("")
+		if err == nil {
+			t.Log(FSCreateLabel())
+		} else {
+			t.Log("SetFSCreateLabel failed", err)
+			t.Fatal(err)
+		}
+		t.Log(PidLabel(1))
+	}
+}

vendor/github.com/opencontainers/selinux/go-selinux/xattrs.go

@@ -0,0 +1,78 @@
+// +build linux
+
+package selinux
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+var _zero uintptr
+
+// Returns a []byte slice if the xattr is set and nil otherwise
+// Requires path and its attribute as arguments
+func lgetxattr(path string, attr string) ([]byte, error) {
+	var sz int
+	pathBytes, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return nil, err
+	}
+	attrBytes, err := syscall.BytePtrFromString(attr)
+	if err != nil {
+		return nil, err
+	}
+
+	// Start with a 128 length byte array
+	sz = 128
+	dest := make([]byte, sz)
+	destBytes := unsafe.Pointer(&dest[0])
+	_sz, _, errno := syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
+
+	switch {
+	case errno == syscall.ENODATA:
+		return nil, errno
+	case errno == syscall.ENOTSUP:
+		return nil, errno
+	case errno == syscall.ERANGE:
+		// 128 byte array might just not be good enough,
+		// A dummy buffer is used ``uintptr(0)`` to get real size
+		// of the xattrs on disk
+		_sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(unsafe.Pointer(nil)), uintptr(0), 0, 0)
+		sz = int(_sz)
+		if sz < 0 {
+			return nil, errno
+		}
+		dest = make([]byte, sz)
+		destBytes := unsafe.Pointer(&dest[0])
+		_sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
+		if errno != 0 {
+			return nil, errno
+		}
+	case errno != 0:
+		return nil, errno
+	}
+	sz = int(_sz)
+	return dest[:sz], nil
+}
+
+func lsetxattr(path string, attr string, data []byte, flags int) error {
+	pathBytes, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+	attrBytes, err := syscall.BytePtrFromString(attr)
+	if err != nil {
+		return err
+	}
+	var dataBytes unsafe.Pointer
+	if len(data) > 0 {
+		dataBytes = unsafe.Pointer(&data[0])
+	} else {
+		dataBytes = unsafe.Pointer(&_zero)
+	}
+	_, _, errno := syscall.Syscall6(syscall.SYS_LSETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(dataBytes), uintptr(len(data)), uintptr(flags), 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}