debian-forge-composer/vendor/github.com/syndtr/gocapability/capability/capability_linux.go
Christian Kellner 986f076276 container: add support for uploading to registries
Add a new generic container registry client via a new `container`
package. Use this to create a command line utility as well as a
new upload target for container registries.

The code uses the github.com/containers/* project and packages to
interact with container registires that is also used by skopeo,
podman et al. One if the dependencies is `proglottis/gpgme` that
is using cgo to bind libgpgme, so we have to add the corresponding
devel package to the BuildRequires as well as installing it on CI.

Checks will follow later via an integration test.
2022-06-29 10:02:46 +02:00

642 lines
12 KiB
Go

// Copyright (c) 2013, Suryandaru Triandana <syndtr@gmail.com>
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package capability
import (
"bufio"
"errors"
"fmt"
"io"
"os"
"strings"
"syscall"
)
var errUnknownVers = errors.New("unknown capability version")
const (
linuxCapVer1 = 0x19980330
linuxCapVer2 = 0x20071026
linuxCapVer3 = 0x20080522
)
var (
capVers uint32
capLastCap Cap
)
func init() {
var hdr capHeader
capget(&hdr, nil)
capVers = hdr.version
if initLastCap() == nil {
CAP_LAST_CAP = capLastCap
if capLastCap > 31 {
capUpperMask = (uint32(1) << (uint(capLastCap) - 31)) - 1
} else {
capUpperMask = 0
}
}
}
func initLastCap() error {
if capLastCap != 0 {
return nil
}
f, err := os.Open("/proc/sys/kernel/cap_last_cap")
if err != nil {
return err
}
defer f.Close()
var b []byte = make([]byte, 11)
_, err = f.Read(b)
if err != nil {
return err
}
fmt.Sscanf(string(b), "%d", &capLastCap)
return nil
}
func mkStringCap(c Capabilities, which CapType) (ret string) {
for i, first := Cap(0), true; i <= CAP_LAST_CAP; i++ {
if !c.Get(which, i) {
continue
}
if first {
first = false
} else {
ret += ", "
}
ret += i.String()
}
return
}
func mkString(c Capabilities, max CapType) (ret string) {
ret = "{"
for i := CapType(1); i <= max; i <<= 1 {
ret += " " + i.String() + "=\""
if c.Empty(i) {
ret += "empty"
} else if c.Full(i) {
ret += "full"
} else {
ret += c.StringCap(i)
}
ret += "\""
}
ret += " }"
return
}
func newPid(pid int) (c Capabilities, err error) {
switch capVers {
case linuxCapVer1:
p := new(capsV1)
p.hdr.version = capVers
p.hdr.pid = int32(pid)
c = p
case linuxCapVer2, linuxCapVer3:
p := new(capsV3)
p.hdr.version = capVers
p.hdr.pid = int32(pid)
c = p
default:
err = errUnknownVers
return
}
return
}
type capsV1 struct {
hdr capHeader
data capData
}
func (c *capsV1) Get(which CapType, what Cap) bool {
if what > 32 {
return false
}
switch which {
case EFFECTIVE:
return (1<<uint(what))&c.data.effective != 0
case PERMITTED:
return (1<<uint(what))&c.data.permitted != 0
case INHERITABLE:
return (1<<uint(what))&c.data.inheritable != 0
}
return false
}
func (c *capsV1) getData(which CapType) (ret uint32) {
switch which {
case EFFECTIVE:
ret = c.data.effective
case PERMITTED:
ret = c.data.permitted
case INHERITABLE:
ret = c.data.inheritable
}
return
}
func (c *capsV1) Empty(which CapType) bool {
return c.getData(which) == 0
}
func (c *capsV1) Full(which CapType) bool {
return (c.getData(which) & 0x7fffffff) == 0x7fffffff
}
func (c *capsV1) Set(which CapType, caps ...Cap) {
for _, what := range caps {
if what > 32 {
continue
}
if which&EFFECTIVE != 0 {
c.data.effective |= 1 << uint(what)
}
if which&PERMITTED != 0 {
c.data.permitted |= 1 << uint(what)
}
if which&INHERITABLE != 0 {
c.data.inheritable |= 1 << uint(what)
}
}
}
func (c *capsV1) Unset(which CapType, caps ...Cap) {
for _, what := range caps {
if what > 32 {
continue
}
if which&EFFECTIVE != 0 {
c.data.effective &= ^(1 << uint(what))
}
if which&PERMITTED != 0 {
c.data.permitted &= ^(1 << uint(what))
}
if which&INHERITABLE != 0 {
c.data.inheritable &= ^(1 << uint(what))
}
}
}
func (c *capsV1) Fill(kind CapType) {
if kind&CAPS == CAPS {
c.data.effective = 0x7fffffff
c.data.permitted = 0x7fffffff
c.data.inheritable = 0
}
}
func (c *capsV1) Clear(kind CapType) {
if kind&CAPS == CAPS {
c.data.effective = 0
c.data.permitted = 0
c.data.inheritable = 0
}
}
func (c *capsV1) StringCap(which CapType) (ret string) {
return mkStringCap(c, which)
}
func (c *capsV1) String() (ret string) {
return mkString(c, BOUNDING)
}
func (c *capsV1) Load() (err error) {
return capget(&c.hdr, &c.data)
}
func (c *capsV1) Apply(kind CapType) error {
if kind&CAPS == CAPS {
return capset(&c.hdr, &c.data)
}
return nil
}
type capsV3 struct {
hdr capHeader
data [2]capData
bounds [2]uint32
ambient [2]uint32
}
func (c *capsV3) Get(which CapType, what Cap) bool {
var i uint
if what > 31 {
i = uint(what) >> 5
what %= 32
}
switch which {
case EFFECTIVE:
return (1<<uint(what))&c.data[i].effective != 0
case PERMITTED:
return (1<<uint(what))&c.data[i].permitted != 0
case INHERITABLE:
return (1<<uint(what))&c.data[i].inheritable != 0
case BOUNDING:
return (1<<uint(what))&c.bounds[i] != 0
case AMBIENT:
return (1<<uint(what))&c.ambient[i] != 0
}
return false
}
func (c *capsV3) getData(which CapType, dest []uint32) {
switch which {
case EFFECTIVE:
dest[0] = c.data[0].effective
dest[1] = c.data[1].effective
case PERMITTED:
dest[0] = c.data[0].permitted
dest[1] = c.data[1].permitted
case INHERITABLE:
dest[0] = c.data[0].inheritable
dest[1] = c.data[1].inheritable
case BOUNDING:
dest[0] = c.bounds[0]
dest[1] = c.bounds[1]
case AMBIENT:
dest[0] = c.ambient[0]
dest[1] = c.ambient[1]
}
}
func (c *capsV3) Empty(which CapType) bool {
var data [2]uint32
c.getData(which, data[:])
return data[0] == 0 && data[1] == 0
}
func (c *capsV3) Full(which CapType) bool {
var data [2]uint32
c.getData(which, data[:])
if (data[0] & 0xffffffff) != 0xffffffff {
return false
}
return (data[1] & capUpperMask) == capUpperMask
}
func (c *capsV3) Set(which CapType, caps ...Cap) {
for _, what := range caps {
var i uint
if what > 31 {
i = uint(what) >> 5
what %= 32
}
if which&EFFECTIVE != 0 {
c.data[i].effective |= 1 << uint(what)
}
if which&PERMITTED != 0 {
c.data[i].permitted |= 1 << uint(what)
}
if which&INHERITABLE != 0 {
c.data[i].inheritable |= 1 << uint(what)
}
if which&BOUNDING != 0 {
c.bounds[i] |= 1 << uint(what)
}
if which&AMBIENT != 0 {
c.ambient[i] |= 1 << uint(what)
}
}
}
func (c *capsV3) Unset(which CapType, caps ...Cap) {
for _, what := range caps {
var i uint
if what > 31 {
i = uint(what) >> 5
what %= 32
}
if which&EFFECTIVE != 0 {
c.data[i].effective &= ^(1 << uint(what))
}
if which&PERMITTED != 0 {
c.data[i].permitted &= ^(1 << uint(what))
}
if which&INHERITABLE != 0 {
c.data[i].inheritable &= ^(1 << uint(what))
}
if which&BOUNDING != 0 {
c.bounds[i] &= ^(1 << uint(what))
}
if which&AMBIENT != 0 {
c.ambient[i] &= ^(1 << uint(what))
}
}
}
func (c *capsV3) Fill(kind CapType) {
if kind&CAPS == CAPS {
c.data[0].effective = 0xffffffff
c.data[0].permitted = 0xffffffff
c.data[0].inheritable = 0
c.data[1].effective = 0xffffffff
c.data[1].permitted = 0xffffffff
c.data[1].inheritable = 0
}
if kind&BOUNDS == BOUNDS {
c.bounds[0] = 0xffffffff
c.bounds[1] = 0xffffffff
}
if kind&AMBS == AMBS {
c.ambient[0] = 0xffffffff
c.ambient[1] = 0xffffffff
}
}
func (c *capsV3) Clear(kind CapType) {
if kind&CAPS == CAPS {
c.data[0].effective = 0
c.data[0].permitted = 0
c.data[0].inheritable = 0
c.data[1].effective = 0
c.data[1].permitted = 0
c.data[1].inheritable = 0
}
if kind&BOUNDS == BOUNDS {
c.bounds[0] = 0
c.bounds[1] = 0
}
if kind&AMBS == AMBS {
c.ambient[0] = 0
c.ambient[1] = 0
}
}
func (c *capsV3) StringCap(which CapType) (ret string) {
return mkStringCap(c, which)
}
func (c *capsV3) String() (ret string) {
return mkString(c, BOUNDING)
}
func (c *capsV3) Load() (err error) {
err = capget(&c.hdr, &c.data[0])
if err != nil {
return
}
var status_path string
if c.hdr.pid == 0 {
status_path = fmt.Sprintf("/proc/self/status")
} else {
status_path = fmt.Sprintf("/proc/%d/status", c.hdr.pid)
}
f, err := os.Open(status_path)
if err != nil {
return
}
b := bufio.NewReader(f)
for {
line, e := b.ReadString('\n')
if e != nil {
if e != io.EOF {
err = e
}
break
}
if strings.HasPrefix(line, "CapB") {
fmt.Sscanf(line[4:], "nd: %08x%08x", &c.bounds[1], &c.bounds[0])
continue
}
if strings.HasPrefix(line, "CapA") {
fmt.Sscanf(line[4:], "mb: %08x%08x", &c.ambient[1], &c.ambient[0])
continue
}
}
f.Close()
return
}
func (c *capsV3) Apply(kind CapType) (err error) {
if kind&BOUNDS == BOUNDS {
var data [2]capData
err = capget(&c.hdr, &data[0])
if err != nil {
return
}
if (1<<uint(CAP_SETPCAP))&data[0].effective != 0 {
for i := Cap(0); i <= CAP_LAST_CAP; i++ {
if c.Get(BOUNDING, i) {
continue
}
err = prctl(syscall.PR_CAPBSET_DROP, uintptr(i), 0, 0, 0)
if err != nil {
// Ignore EINVAL since the capability may not be supported in this system.
if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINVAL {
err = nil
continue
}
return
}
}
}
}
if kind&CAPS == CAPS {
err = capset(&c.hdr, &c.data[0])
if err != nil {
return
}
}
if kind&AMBS == AMBS {
for i := Cap(0); i <= CAP_LAST_CAP; i++ {
action := pr_CAP_AMBIENT_LOWER
if c.Get(AMBIENT, i) {
action = pr_CAP_AMBIENT_RAISE
}
err := prctl(pr_CAP_AMBIENT, action, uintptr(i), 0, 0)
// Ignore EINVAL as not supported on kernels before 4.3
if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINVAL {
err = nil
continue
}
}
}
return
}
func newFile(path string) (c Capabilities, err error) {
c = &capsFile{path: path}
return
}
type capsFile struct {
path string
data vfscapData
}
func (c *capsFile) Get(which CapType, what Cap) bool {
var i uint
if what > 31 {
if c.data.version == 1 {
return false
}
i = uint(what) >> 5
what %= 32
}
switch which {
case EFFECTIVE:
return (1<<uint(what))&c.data.effective[i] != 0
case PERMITTED:
return (1<<uint(what))&c.data.data[i].permitted != 0
case INHERITABLE:
return (1<<uint(what))&c.data.data[i].inheritable != 0
}
return false
}
func (c *capsFile) getData(which CapType, dest []uint32) {
switch which {
case EFFECTIVE:
dest[0] = c.data.effective[0]
dest[1] = c.data.effective[1]
case PERMITTED:
dest[0] = c.data.data[0].permitted
dest[1] = c.data.data[1].permitted
case INHERITABLE:
dest[0] = c.data.data[0].inheritable
dest[1] = c.data.data[1].inheritable
}
}
func (c *capsFile) Empty(which CapType) bool {
var data [2]uint32
c.getData(which, data[:])
return data[0] == 0 && data[1] == 0
}
func (c *capsFile) Full(which CapType) bool {
var data [2]uint32
c.getData(which, data[:])
if c.data.version == 0 {
return (data[0] & 0x7fffffff) == 0x7fffffff
}
if (data[0] & 0xffffffff) != 0xffffffff {
return false
}
return (data[1] & capUpperMask) == capUpperMask
}
func (c *capsFile) Set(which CapType, caps ...Cap) {
for _, what := range caps {
var i uint
if what > 31 {
if c.data.version == 1 {
continue
}
i = uint(what) >> 5
what %= 32
}
if which&EFFECTIVE != 0 {
c.data.effective[i] |= 1 << uint(what)
}
if which&PERMITTED != 0 {
c.data.data[i].permitted |= 1 << uint(what)
}
if which&INHERITABLE != 0 {
c.data.data[i].inheritable |= 1 << uint(what)
}
}
}
func (c *capsFile) Unset(which CapType, caps ...Cap) {
for _, what := range caps {
var i uint
if what > 31 {
if c.data.version == 1 {
continue
}
i = uint(what) >> 5
what %= 32
}
if which&EFFECTIVE != 0 {
c.data.effective[i] &= ^(1 << uint(what))
}
if which&PERMITTED != 0 {
c.data.data[i].permitted &= ^(1 << uint(what))
}
if which&INHERITABLE != 0 {
c.data.data[i].inheritable &= ^(1 << uint(what))
}
}
}
func (c *capsFile) Fill(kind CapType) {
if kind&CAPS == CAPS {
c.data.effective[0] = 0xffffffff
c.data.data[0].permitted = 0xffffffff
c.data.data[0].inheritable = 0
if c.data.version == 2 {
c.data.effective[1] = 0xffffffff
c.data.data[1].permitted = 0xffffffff
c.data.data[1].inheritable = 0
}
}
}
func (c *capsFile) Clear(kind CapType) {
if kind&CAPS == CAPS {
c.data.effective[0] = 0
c.data.data[0].permitted = 0
c.data.data[0].inheritable = 0
if c.data.version == 2 {
c.data.effective[1] = 0
c.data.data[1].permitted = 0
c.data.data[1].inheritable = 0
}
}
}
func (c *capsFile) StringCap(which CapType) (ret string) {
return mkStringCap(c, which)
}
func (c *capsFile) String() (ret string) {
return mkString(c, INHERITABLE)
}
func (c *capsFile) Load() (err error) {
return getVfsCap(c.path, &c.data)
}
func (c *capsFile) Apply(kind CapType) (err error) {
if kind&CAPS == CAPS {
return setVfsCap(c.path, &c.data)
}
return
}