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Improve libcontainer namespace and cap format

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Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
This commit is contained in:
Michael Crosby 2014-05-05 12:34:21 -07:00
parent bbc3c913a9
commit 412c081a9b
9 changed files with 128 additions and 206 deletions
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4
libcontainer/container.go
View file

@ -18,8 +18,8 @@ type Container struct {
WorkingDir string `json:"working_dir,omitempty"` // current working directory
Env []string `json:"environment,omitempty"` // environment to set
Tty bool `json:"tty,omitempty"` // setup a proper tty or not
Namespaces Namespaces `json:"namespaces,omitempty"` // namespaces to apply
CapabilitiesMask Capabilities `json:"capabilities_mask,omitempty"` // capabilities to drop
Namespaces map[string]bool `json:"namespaces,omitempty"` // namespaces to apply
CapabilitiesMask map[string]bool `json:"capabilities_mask,omitempty"` // capabilities to drop
Networks []*Network `json:"networks,omitempty"` // nil for host's network stack
Cgroups *cgroups.Cgroup `json:"cgroups,omitempty"` // cgroups
Context Context `json:"context,omitempty"` // generic context for specific options (apparmor, selinux)

185
libcontainer/container.json
View file

@ -1,151 +1,62 @@
{
"mounts" : [
"namespaces": {
"NEWNET": true,
"NEWPID": true,
"NEWIPC": true,
"NEWUTS": true,
"NEWNS": true
},
"networks": [
{
"type" : "devtmpfs"
"gateway": "localhost",
"type": "loopback",
"address": "127.0.0.1/0",
"mtu": 1500
},
{
"gateway": "172.17.42.1",
"context": {
"prefix": "veth",
"bridge": "docker0"
},
"type": "veth",
"address": "172.17.42.2/16",
"mtu": 1500
}
],
"tty" : true,
"capabilities_mask": {
"SYSLOG": false,
"MKNOD": true,
"NET_ADMIN": false,
"MAC_ADMIN": false,
"MAC_OVERRIDE": false,
"AUDIT_CONTROL": false,
"AUDIT_WRITE": false,
"SYS_TTY_CONFIG": false,
"SETPCAP": false,
"SYS_MODULE": false,
"SYS_RAWIO": false,
"SYS_PACCT": false,
"SYS_ADMIN": false,
"SYS_NICE": false,
"SYS_RESOURCE": false,
"SYS_TIME": false
},
"cgroups": {
"name": "docker-koye",
"parent": "docker"
},
"hostname": "koye",
"environment": [
"HOME=/",
"PATH=PATH=$PATH:/bin:/usr/bin:/sbin:/usr/sbin",
"container=docker",
"TERM=xterm-256color"
],
"hostname" : "koye",
"cgroups" : {
"parent" : "docker",
"name" : "docker-koye"
},
"capabilities_mask" : [
"tty": true,
"mounts": [
{
"value" : 8,
"key" : "SETPCAP",
"enabled" : false
},
{
"enabled" : false,
"value" : 16,
"key" : "SYS_MODULE"
},
{
"value" : 17,
"key" : "SYS_RAWIO",
"enabled" : false
},
{
"key" : "SYS_PACCT",
"value" : 20,
"enabled" : false
},
{
"value" : 21,
"key" : "SYS_ADMIN",
"enabled" : false
},
{
"value" : 23,
"key" : "SYS_NICE",
"enabled" : false
},
{
"value" : 24,
"key" : "SYS_RESOURCE",
"enabled" : false
},
{
"key" : "SYS_TIME",
"value" : 25,
"enabled" : false
},
{
"enabled" : false,
"value" : 26,
"key" : "SYS_TTY_CONFIG"
},
{
"key" : "AUDIT_WRITE",
"value" : 29,
"enabled" : false
},
{
"value" : 30,
"key" : "AUDIT_CONTROL",
"enabled" : false
},
{
"enabled" : false,
"key" : "MAC_OVERRIDE",
"value" : 32
},
{
"enabled" : false,
"key" : "MAC_ADMIN",
"value" : 33
},
{
"key" : "NET_ADMIN",
"value" : 12,
"enabled" : false
},
{
"value" : 27,
"key" : "MKNOD",
"enabled" : true
},
{
"value" : 34,
"key" : "SYSLOG",
"enabled" : false
}
],
"networks" : [
{
"mtu" : 1500,
"address" : "127.0.0.1/0",
"type" : "loopback",
"gateway" : "localhost"
},
{
"mtu" : 1500,
"address" : "172.17.42.2/16",
"type" : "veth",
"context" : {
"bridge" : "docker0",
"prefix" : "veth"
},
"gateway" : "172.17.42.1"
}
],
"namespaces" : [
{
"key" : "NEWNS",
"value" : 131072,
"enabled" : true,
"file" : "mnt"
},
{
"key" : "NEWUTS",
"value" : 67108864,
"enabled" : true,
"file" : "uts"
},
{
"enabled" : true,
"file" : "ipc",
"key" : "NEWIPC",
"value" : 134217728
},
{
"file" : "pid",
"enabled" : true,
"value" : 536870912,
"key" : "NEWPID"
},
{
"enabled" : true,
"file" : "net",
"key" : "NEWNET",
"value" : 1073741824
"type": "devtmpfs"
}
]
}

14
libcontainer/container_test.go
View file

@ -15,7 +15,7 @@ func TestContainerJsonFormat(t *testing.T) {
var container *Container
if err := json.NewDecoder(f).Decode(&container); err != nil {
t.Fatal("failed to decode container config")
t.Fatalf("failed to decode container config: %s", err)
}
if container.Hostname != "koye" {
t.Log("hostname is not set")
@ -27,32 +27,32 @@ func TestContainerJsonFormat(t *testing.T) {
t.Fail()
}
if !container.Namespaces.Contains("NEWNET") {
if !container.Namespaces["NEWNET"] {
t.Log("namespaces should contain NEWNET")
t.Fail()
}
if container.Namespaces.Contains("NEWUSER") {
if container.Namespaces["NEWUSER"] {
t.Log("namespaces should not contain NEWUSER")
t.Fail()
}
if !container.CapabilitiesMask.Contains("SYS_ADMIN") {
if _, exists := container.CapabilitiesMask["SYS_ADMIN"]; !exists {
t.Log("capabilities mask should contain SYS_ADMIN")
t.Fail()
}
if container.CapabilitiesMask.Get("SYS_ADMIN").Enabled {
if container.CapabilitiesMask["SYS_ADMIN"] {
t.Log("SYS_ADMIN should not be enabled in capabilities mask")
t.Fail()
}
if !container.CapabilitiesMask.Get("MKNOD").Enabled {
if !container.CapabilitiesMask["MKNOD"] {
t.Log("MKNOD should be enabled in capabilities mask")
t.Fail()
}
if container.CapabilitiesMask.Contains("SYS_CHROOT") {
if container.CapabilitiesMask["SYS_CHROOT"] {
t.Log("capabilities mask should not contain SYS_CHROOT")
t.Fail()
}

8
libcontainer/nsinit/exec.go
View file

@ -159,11 +159,13 @@ func InitializeNetworking(container *libcontainer.Container, nspid int, pipe *Sy
// GetNamespaceFlags parses the container's Namespaces options to set the correct
// flags on clone, unshare, and setns
func GetNamespaceFlags(namespaces libcontainer.Namespaces) (flag int) {
for _, ns := range namespaces {
if ns.Enabled {
func GetNamespaceFlags(namespaces map[string]bool) (flag int) {
for key, enabled := range namespaces {
if enabled {
if ns := libcontainer.GetNamespace(key); ns != nil {
flag |= ns.Value
}
}
}
return flag
}

21
libcontainer/nsinit/execin.go
View file

@ -23,14 +23,16 @@ func ExecIn(container *libcontainer.Container, nspid int, args []string) (int, e
return -1, err
}
for _, nsv := range container.Namespaces {
for key, enabled := range container.Namespaces {
// skip the PID namespace on unshare because it it not supported
if nsv.Enabled && nsv.Key != "NEWPID" {
if err := system.Unshare(nsv.Value); err != nil {
if enabled && key != "NEWPID" {
if ns := libcontainer.GetNamespace(key); ns != nil {
if err := system.Unshare(ns.Value); err != nil {
return -1, err
}
}
}
}
fds, err := getNsFds(nspid, container)
closeFds := func() {
for _, f := range fds {
@ -59,7 +61,7 @@ func ExecIn(container *libcontainer.Container, nspid int, args []string) (int, e
// if the container has a new pid and mount namespace we need to
// remount proc and sys to pick up the changes
if container.Namespaces.Contains("NEWNS") && container.Namespaces.Contains("NEWPID") {
if container.Namespaces["NEWNS"] && container.Namespaces["NEWPID"] {
pid, err := system.Fork()
if err != nil {
return -1, err
@ -102,13 +104,18 @@ dropAndExec:
}
func getNsFds(pid int, container *libcontainer.Container) ([]uintptr, error) {
fds := make([]uintptr, len(container.Namespaces))
for i, ns := range container.Namespaces {
fds := []uintptr{}
for key, enabled := range container.Namespaces {
if enabled {
if ns := libcontainer.GetNamespace(key); ns != nil {
f, err := os.OpenFile(filepath.Join("/proc/", strconv.Itoa(pid), "ns", ns.File), os.O_RDONLY, 0)
if err != nil {
return fds, err
}
fds[i] = f.Fd()
fds = append(fds, f.Fd())
}
}
}
return fds, nil
}

2
libcontainer/nsinit/unsupported.go
View file

@ -23,6 +23,6 @@ func SetupCgroups(container *libcontainer.Container, nspid int) (cgroups.ActiveC
return nil, libcontainer.ErrUnsupported
}
func GetNamespaceFlags(namespaces libcontainer.Namespaces) (flag int) {
func GetNamespaceFlags(namespaces map[string]bool) (flag int) {
return 0
}

9
libcontainer/security/capabilities/capabilities.go
View file

@ -1,9 +1,10 @@
package capabilities
import (
"os"
"github.com/dotcloud/docker/pkg/libcontainer"
"github.com/syndtr/gocapability/capability"
"os"
)
// DropCapabilities drops capabilities for the current process based
@ -26,10 +27,12 @@ func DropCapabilities(container *libcontainer.Container) error {
// getCapabilitiesMask returns the specific cap mask values for the libcontainer types
func getCapabilitiesMask(container *libcontainer.Container) []capability.Cap {
drop := []capability.Cap{}
for _, c := range container.CapabilitiesMask {
if !c.Enabled {
for key, enabled := range container.CapabilitiesMask {
if !enabled {
if c := libcontainer.GetCapability(key); c != nil {
drop = append(drop, c.Value)
}
}
}
return drop
}

35
libcontainer/types.go
View file

@ -2,6 +2,7 @@ package libcontainer
import (
"errors"
"github.com/syndtr/gocapability/capability"
)
@ -38,29 +39,28 @@ var (
namespaceList = Namespaces{}
capabilityList = Capabilities{
{Key: "SETPCAP", Value: capability.CAP_SETPCAP, Enabled: false},
{Key: "SYS_MODULE", Value: capability.CAP_SYS_MODULE, Enabled: false},
{Key: "SYS_RAWIO", Value: capability.CAP_SYS_RAWIO, Enabled: false},
{Key: "SYS_PACCT", Value: capability.CAP_SYS_PACCT, Enabled: false},
{Key: "SYS_ADMIN", Value: capability.CAP_SYS_ADMIN, Enabled: false},
{Key: "SYS_NICE", Value: capability.CAP_SYS_NICE, Enabled: false},
{Key: "SYS_RESOURCE", Value: capability.CAP_SYS_RESOURCE, Enabled: false},
{Key: "SYS_TIME", Value: capability.CAP_SYS_TIME, Enabled: false},
{Key: "SYS_TTY_CONFIG", Value: capability.CAP_SYS_TTY_CONFIG, Enabled: false},
{Key: "MKNOD", Value: capability.CAP_MKNOD, Enabled: false},
{Key: "AUDIT_WRITE", Value: capability.CAP_AUDIT_WRITE, Enabled: false},
{Key: "AUDIT_CONTROL", Value: capability.CAP_AUDIT_CONTROL, Enabled: false},
{Key: "MAC_OVERRIDE", Value: capability.CAP_MAC_OVERRIDE, Enabled: false},
{Key: "MAC_ADMIN", Value: capability.CAP_MAC_ADMIN, Enabled: false},
{Key: "NET_ADMIN", Value: capability.CAP_NET_ADMIN, Enabled: false},
{Key: "SYSLOG", Value: capability.CAP_SYSLOG, Enabled: false},
{Key: "SETPCAP", Value: capability.CAP_SETPCAP},
{Key: "SYS_MODULE", Value: capability.CAP_SYS_MODULE},
{Key: "SYS_RAWIO", Value: capability.CAP_SYS_RAWIO},
{Key: "SYS_PACCT", Value: capability.CAP_SYS_PACCT},
{Key: "SYS_ADMIN", Value: capability.CAP_SYS_ADMIN},
{Key: "SYS_NICE", Value: capability.CAP_SYS_NICE},
{Key: "SYS_RESOURCE", Value: capability.CAP_SYS_RESOURCE},
{Key: "SYS_TIME", Value: capability.CAP_SYS_TIME},
{Key: "SYS_TTY_CONFIG", Value: capability.CAP_SYS_TTY_CONFIG},
{Key: "MKNOD", Value: capability.CAP_MKNOD},
{Key: "AUDIT_WRITE", Value: capability.CAP_AUDIT_WRITE},
{Key: "AUDIT_CONTROL", Value: capability.CAP_AUDIT_CONTROL},
{Key: "MAC_OVERRIDE", Value: capability.CAP_MAC_OVERRIDE},
{Key: "MAC_ADMIN", Value: capability.CAP_MAC_ADMIN},
{Key: "NET_ADMIN", Value: capability.CAP_NET_ADMIN},
{Key: "SYSLOG", Value: capability.CAP_SYSLOG},
}
)
type (
Namespace struct {
Key string `json:"key,omitempty"`
Enabled bool `json:"enabled,omitempty"`
Value int `json:"value,omitempty"`
File string `json:"file,omitempty"`
}
@ -99,7 +99,6 @@ func (n Namespaces) Get(ns string) *Namespace {
type (
Capability struct {
Key string `json:"key,omitempty"`
Enabled bool `json:"enabled"`
Value capability.Cap `json:"value,omitempty"`
}
Capabilities []*Capability

12
libcontainer/types_linux.go
View file

@ -6,11 +6,11 @@ import (
func init() {
namespaceList = Namespaces{
{Key: "NEWNS", Value: syscall.CLONE_NEWNS, File: "mnt", Enabled: true},
{Key: "NEWUTS", Value: syscall.CLONE_NEWUTS, File: "uts", Enabled: true},
{Key: "NEWIPC", Value: syscall.CLONE_NEWIPC, File: "ipc", Enabled: true},
{Key: "NEWUSER", Value: syscall.CLONE_NEWUSER, File: "user", Enabled: true},
{Key: "NEWPID", Value: syscall.CLONE_NEWPID, File: "pid", Enabled: true},
{Key: "NEWNET", Value: syscall.CLONE_NEWNET, File: "net", Enabled: true},
{Key: "NEWNS", Value: syscall.CLONE_NEWNS, File: "mnt"},
{Key: "NEWUTS", Value: syscall.CLONE_NEWUTS, File: "uts"},
{Key: "NEWIPC", Value: syscall.CLONE_NEWIPC, File: "ipc"},
{Key: "NEWUSER", Value: syscall.CLONE_NEWUSER, File: "user"},
{Key: "NEWPID", Value: syscall.CLONE_NEWPID, File: "pid"},
{Key: "NEWNET", Value: syscall.CLONE_NEWNET, File: "net"},
}
}