Vendor after merging mtrmac/image:docker-archive-auto-compression

Signed-off-by: Miloslav Trmač <mitr@redhat.com>
This commit is contained in:
Miloslav Trmač
2018-07-14 02:36:48 +02:00
parent ae64ff7084
commit 1a259b76da
212 changed files with 13417 additions and 1764 deletions

View File

@@ -3,13 +3,12 @@
package system
import (
"bufio"
"fmt"
"os"
"os/exec"
"syscall" // only for exec
"unsafe"
"github.com/opencontainers/runc/libcontainer/user"
"golang.org/x/sys/unix"
)
@@ -102,34 +101,43 @@ func Setctty() error {
}
// RunningInUserNS detects whether we are currently running in a user namespace.
// Copied from github.com/lxc/lxd/shared/util.go
// Originally copied from github.com/lxc/lxd/shared/util.go
func RunningInUserNS() bool {
file, err := os.Open("/proc/self/uid_map")
uidmap, err := user.CurrentProcessUIDMap()
if err != nil {
// This kernel-provided file only exists if user namespaces are supported
return false
}
defer file.Close()
return UIDMapInUserNS(uidmap)
}
buf := bufio.NewReader(file)
l, _, err := buf.ReadLine()
if err != nil {
return false
}
line := string(l)
var a, b, c int64
fmt.Sscanf(line, "%d %d %d", &a, &b, &c)
func UIDMapInUserNS(uidmap []user.IDMap) bool {
/*
* We assume we are in the initial user namespace if we have a full
* range - 4294967295 uids starting at uid 0.
*/
if a == 0 && b == 0 && c == 4294967295 {
if len(uidmap) == 1 && uidmap[0].ID == 0 && uidmap[0].ParentID == 0 && uidmap[0].Count == 4294967295 {
return false
}
return true
}
// GetParentNSeuid returns the euid within the parent user namespace
func GetParentNSeuid() int64 {
euid := int64(os.Geteuid())
uidmap, err := user.CurrentProcessUIDMap()
if err != nil {
// This kernel-provided file only exists if user namespaces are supported
return euid
}
for _, um := range uidmap {
if um.ID <= euid && euid <= um.ID+um.Count-1 {
return um.ParentID + euid - um.ID
}
}
return euid
}
// SetSubreaper sets the value i as the subreaper setting for the calling process
func SetSubreaper(i int) error {
return unix.Prctl(PR_SET_CHILD_SUBREAPER, uintptr(i), 0, 0, 0)

View File

@@ -2,8 +2,26 @@
package system
import (
"os"
"github.com/opencontainers/runc/libcontainer/user"
)
// RunningInUserNS is a stub for non-Linux systems
// Always returns false
func RunningInUserNS() bool {
return false
}
// UIDMapInUserNS is a stub for non-Linux systems
// Always returns false
func UIDMapInUserNS(uidmap []user.IDMap) bool {
return false
}
// GetParentNSeuid returns the euid within the parent user namespace
// Always returns os.Geteuid on non-linux
func GetParentNSeuid() int {
return os.Geteuid()
}

View File

@@ -114,3 +114,29 @@ func CurrentUser() (User, error) {
func CurrentGroup() (Group, error) {
return LookupGid(unix.Getgid())
}
func CurrentUserSubUIDs() ([]SubID, error) {
u, err := CurrentUser()
if err != nil {
return nil, err
}
return ParseSubIDFileFilter("/etc/subuid",
func(entry SubID) bool { return entry.Name == u.Name })
}
func CurrentGroupSubGIDs() ([]SubID, error) {
g, err := CurrentGroup()
if err != nil {
return nil, err
}
return ParseSubIDFileFilter("/etc/subgid",
func(entry SubID) bool { return entry.Name == g.Name })
}
func CurrentProcessUIDMap() ([]IDMap, error) {
return ParseIDMapFile("/proc/self/uid_map")
}
func CurrentProcessGIDMap() ([]IDMap, error) {
return ParseIDMapFile("/proc/self/gid_map")
}

View File

@@ -75,12 +75,29 @@ func groupFromOS(g *user.Group) (Group, error) {
return newGroup, nil
}
// SubID represents an entry in /etc/sub{u,g}id
type SubID struct {
Name string
SubID int64
Count int64
}
// IDMap represents an entry in /proc/PID/{u,g}id_map
type IDMap struct {
ID int64
ParentID int64
Count int64
}
func parseLine(line string, v ...interface{}) {
if line == "" {
parseParts(strings.Split(line, ":"), v...)
}
func parseParts(parts []string, v ...interface{}) {
if len(parts) == 0 {
return
}
parts := strings.Split(line, ":")
for i, p := range parts {
// Ignore cases where we don't have enough fields to populate the arguments.
// Some configuration files like to misbehave.
@@ -96,6 +113,8 @@ func parseLine(line string, v ...interface{}) {
case *int:
// "numbers", with conversion errors ignored because of some misbehaving configuration files.
*e, _ = strconv.Atoi(p)
case *int64:
*e, _ = strconv.ParseInt(p, 10, 64)
case *[]string:
// Comma-separated lists.
if p != "" {
@@ -105,7 +124,7 @@ func parseLine(line string, v ...interface{}) {
}
default:
// Someone goof'd when writing code using this function. Scream so they can hear us.
panic(fmt.Sprintf("parseLine only accepts {*string, *int, *[]string} as arguments! %#v is not a pointer!", e))
panic(fmt.Sprintf("parseLine only accepts {*string, *int, *int64, *[]string} as arguments! %#v is not a pointer!", e))
}
}
}
@@ -479,3 +498,111 @@ func GetAdditionalGroupsPath(additionalGroups []string, groupPath string) ([]int
}
return GetAdditionalGroups(additionalGroups, group)
}
func ParseSubIDFile(path string) ([]SubID, error) {
subid, err := os.Open(path)
if err != nil {
return nil, err
}
defer subid.Close()
return ParseSubID(subid)
}
func ParseSubID(subid io.Reader) ([]SubID, error) {
return ParseSubIDFilter(subid, nil)
}
func ParseSubIDFileFilter(path string, filter func(SubID) bool) ([]SubID, error) {
subid, err := os.Open(path)
if err != nil {
return nil, err
}
defer subid.Close()
return ParseSubIDFilter(subid, filter)
}
func ParseSubIDFilter(r io.Reader, filter func(SubID) bool) ([]SubID, error) {
if r == nil {
return nil, fmt.Errorf("nil source for subid-formatted data")
}
var (
s = bufio.NewScanner(r)
out = []SubID{}
)
for s.Scan() {
if err := s.Err(); err != nil {
return nil, err
}
line := strings.TrimSpace(s.Text())
if line == "" {
continue
}
// see: man 5 subuid
p := SubID{}
parseLine(line, &p.Name, &p.SubID, &p.Count)
if filter == nil || filter(p) {
out = append(out, p)
}
}
return out, nil
}
func ParseIDMapFile(path string) ([]IDMap, error) {
r, err := os.Open(path)
if err != nil {
return nil, err
}
defer r.Close()
return ParseIDMap(r)
}
func ParseIDMap(r io.Reader) ([]IDMap, error) {
return ParseIDMapFilter(r, nil)
}
func ParseIDMapFileFilter(path string, filter func(IDMap) bool) ([]IDMap, error) {
r, err := os.Open(path)
if err != nil {
return nil, err
}
defer r.Close()
return ParseIDMapFilter(r, filter)
}
func ParseIDMapFilter(r io.Reader, filter func(IDMap) bool) ([]IDMap, error) {
if r == nil {
return nil, fmt.Errorf("nil source for idmap-formatted data")
}
var (
s = bufio.NewScanner(r)
out = []IDMap{}
)
for s.Scan() {
if err := s.Err(); err != nil {
return nil, err
}
line := strings.TrimSpace(s.Text())
if line == "" {
continue
}
// see: man 7 user_namespaces
p := IDMap{}
parseParts(strings.Fields(line), &p.ID, &p.ParentID, &p.Count)
if filter == nil || filter(p) {
out = append(out, p)
}
}
return out, nil
}