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Merge pull request #1715 from baude/getusergroup

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get user and group information using securejoin and runc's user library
This commit is contained in:
OpenShift Merge Robot 2018-10-30 11:49:15 -07:00 committed by GitHub
parent ce24ce7c53 1dd7f13dfb
commit 319a7a7043
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GPG key ID: 4AEE18F83AFDEB23
4 changed files with 201 additions and 63 deletions
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8
libpod/container_api.go
View file

@ -10,8 +10,8 @@ import (
"time"
"github.com/containers/libpod/libpod/driver"
"github.com/containers/libpod/pkg/chrootuser"
"github.com/containers/libpod/pkg/inspect"
"github.com/containers/libpod/pkg/lookup"
"github.com/containers/storage/pkg/stringid"
"github.com/docker/docker/daemon/caps"
"github.com/pkg/errors"
@ -292,13 +292,13 @@ func (c *Container) Exec(tty, privileged bool, env, cmd []string, user string) e
// the host
hostUser := ""
if user != "" {
uid, gid, err := chrootuser.GetUser(c.state.Mountpoint, user)
execUser, err := lookup.GetUserGroupInfo(c.state.Mountpoint, user, nil)
if err != nil {
return errors.Wrapf(err, "error getting user to launch exec session as")
return err
}
// runc expects user formatted as uid:gid
hostUser = fmt.Sprintf("%d:%d", uid, gid)
hostUser = fmt.Sprintf("%d:%d", execUser.Uid, execUser.Gid)
}
// Generate exec session ID

56
libpod/container_internal.go
View file

@ -5,6 +5,7 @@ import (
"context"
"encoding/json"
"fmt"
"github.com/opencontainers/runc/libcontainer/user"
"io"
"io/ioutil"
"os"
@ -14,9 +15,9 @@ import (
"syscall"
"github.com/containers/buildah/imagebuildah"
"github.com/containers/libpod/pkg/chrootuser"
"github.com/containers/libpod/pkg/hooks"
"github.com/containers/libpod/pkg/hooks/exec"
"github.com/containers/libpod/pkg/lookup"
"github.com/containers/libpod/pkg/resolvconf"
"github.com/containers/libpod/pkg/rootless"
"github.com/containers/libpod/pkg/secrets"
@ -1029,7 +1030,8 @@ func (c *Container) writeStringToRundir(destFile, output string) (string, error)
func (c *Container) generatePasswd() (string, error) {
var (
groupspec string
gid uint32
group *user.Group
gid int
)
if c.config.User == "" {
return "", nil
@ -1044,21 +1046,27 @@ func (c *Container) generatePasswd() (string, error) {
if err != nil {
return "", nil
}
// if UID exists inside of container rootfs /etc/passwd then
// don't generate passwd
if _, _, err := chrootuser.LookupUIDInContainer(c.state.Mountpoint, uid); err == nil {
// Lookup the user to see if it exists in the container image
_, err = lookup.GetUser(c.state.Mountpoint, userspec)
if err != nil && err != user.ErrNoPasswdEntries {
return "", err
}
if err == nil {
return "", nil
}
if err == nil && groupspec != "" {
if groupspec != "" {
if !c.state.Mounted {
return "", errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to translate group field for passwd record", c.ID())
}
gid, err = chrootuser.GetGroup(c.state.Mountpoint, groupspec)
group, err = lookup.GetGroup(c.state.Mountpoint, groupspec)
if err != nil {
return "", errors.Wrapf(err, "unable to get gid from %s formporary passwd file")
if err == user.ErrNoGroupEntries {
return "", errors.Wrapf(err, "unable to get gid %s from group file", groupspec)
}
return "", err
}
gid = group.Gid
}
originPasswdFile := filepath.Join(c.state.Mountpoint, "/etc/passwd")
orig, err := ioutil.ReadFile(originPasswdFile)
if err != nil {
@ -1153,6 +1161,7 @@ func (c *Container) generateHosts() (string, error) {
}
func (c *Container) addLocalVolumes(ctx context.Context, g *generate.Generator) error {
var uid, gid int
mountPoint := c.state.Mountpoint
if !c.state.Mounted {
return errors.Wrapf(ErrInternal, "container is not mounted")
@ -1176,6 +1185,18 @@ func (c *Container) addLocalVolumes(ctx context.Context, g *generate.Generator)
}
}
if c.config.User != "" {
if !c.state.Mounted {
return errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to translate User field", c.ID())
}
execUser, err := lookup.GetUserGroupInfo(c.state.Mountpoint, c.config.User, nil)
if err != nil {
return err
}
uid = execUser.Uid
gid = execUser.Gid
}
for k := range imageData.ContainerConfig.Volumes {
mount := spec.Mount{
Destination: k,
@ -1186,19 +1207,6 @@ func (c *Container) addLocalVolumes(ctx context.Context, g *generate.Generator)
continue
}
volumePath := filepath.Join(c.config.StaticDir, "volumes", k)
var (
uid uint32
gid uint32
)
if c.config.User != "" {
if !c.state.Mounted {
return errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to translate User field", c.ID())
}
uid, gid, err = chrootuser.GetUser(c.state.Mountpoint, c.config.User)
if err != nil {
return err
}
}
// Ensure the symlinks are resolved
resolvedSymlink, err := imagebuildah.ResolveSymLink(mountPoint, k)
@ -1218,7 +1226,7 @@ func (c *Container) addLocalVolumes(ctx context.Context, g *generate.Generator)
return errors.Wrapf(err, "error creating directory %q for volume %q in container %q", volumePath, k, c.ID())
}
if err = os.Chown(srcPath, int(uid), int(gid)); err != nil {
if err = os.Chown(srcPath, uid, gid); err != nil {
return errors.Wrapf(err, "error chowning directory %q for volume %q in container %q", srcPath, k, c.ID())
}
}
@ -1228,7 +1236,7 @@ func (c *Container) addLocalVolumes(ctx context.Context, g *generate.Generator)
return errors.Wrapf(err, "error creating directory %q for volume %q in container %q", volumePath, k, c.ID())
}
if err = os.Chown(volumePath, int(uid), int(gid)); err != nil {
if err = os.Chown(volumePath, uid, gid); err != nil {
return errors.Wrapf(err, "error chowning directory %q for volume %q in container %q", volumePath, k, c.ID())
}

44
libpod/container_internal_linux.go
View file

@ -19,12 +19,10 @@ import (
cnitypes "github.com/containernetworking/cni/pkg/types/current"
"github.com/containernetworking/plugins/pkg/ns"
crioAnnotations "github.com/containers/libpod/pkg/annotations"
"github.com/containers/libpod/pkg/chrootuser"
"github.com/containers/libpod/pkg/criu"
"github.com/containers/libpod/pkg/lookup"
"github.com/containers/libpod/pkg/rootless"
"github.com/containers/storage/pkg/idtools"
"github.com/cyphar/filepath-securejoin"
"github.com/opencontainers/runc/libcontainer/user"
spec "github.com/opencontainers/runtime-spec/specs-go"
"github.com/opencontainers/runtime-tools/generate"
"github.com/opencontainers/selinux/go-selinux/label"
@ -135,6 +133,10 @@ func (c *Container) cleanupNetwork() error {
// Generate spec for a container
// Accepts a map of the container's dependencies
func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
execUser, err := lookup.GetUserGroupInfo(c.state.Mountpoint, c.config.User, nil)
if err != nil {
return nil, err
}
g := generate.NewFromSpec(c.config.Spec)
// If network namespace was requested, add it now
@ -188,7 +190,6 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
}
}
var err error
if !rootless.IsRootless() {
if c.state.ExtensionStageHooks, err = c.setupOCIHooks(ctx, g.Config); err != nil {
return nil, errors.Wrapf(err, "error setting up OCI Hooks")
@ -206,13 +207,9 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
if !c.state.Mounted {
return nil, errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to translate User field", c.ID())
}
uid, gid, err := chrootuser.GetUser(c.state.Mountpoint, c.config.User)
if err != nil {
return nil, err
}
// User and Group must go together
g.SetProcessUID(uid)
g.SetProcessGID(gid)
g.SetProcessUID(uint32(execUser.Uid))
g.SetProcessGID(uint32(execUser.Gid))
}
// Add addition groups if c.config.GroupAdd is not empty
@ -220,11 +217,8 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
if !c.state.Mounted {
return nil, errors.Wrapf(ErrCtrStateInvalid, "container %s must be mounted in order to add additional groups", c.ID())
}
for _, group := range c.config.Groups {
gid, err := chrootuser.GetGroup(c.state.Mountpoint, group)
if err != nil {
return nil, err
}
gids, _ := lookup.GetContainerGroups(c.config.Groups, c.state.Mountpoint, nil)
for _, gid := range gids {
g.AddProcessAdditionalGid(gid)
}
}
@ -237,26 +231,6 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
// Look up and add groups the user belongs to, if a group wasn't directly specified
if !rootless.IsRootless() && !strings.Contains(c.config.User, ":") {
var groupDest, passwdDest string
defaultExecUser := user.ExecUser{
Uid: 0,
Gid: 0,
Home: "/",
}
// Make sure the /etc/group and /etc/passwd destinations are not a symlink to something naughty
if groupDest, err = securejoin.SecureJoin(c.state.Mountpoint, "/etc/group"); err != nil {
logrus.Debug(err)
return nil, err
}
if passwdDest, err = securejoin.SecureJoin(c.state.Mountpoint, "/etc/passwd"); err != nil {
logrus.Debug(err)
return nil, err
}
execUser, err := user.GetExecUserPath(c.config.User, &defaultExecUser, passwdDest, groupDest)
if err != nil {
return nil, err
}
for _, gid := range execUser.Sgids {
g.AddProcessAdditionalGid(uint32(gid))
}

156
pkg/lookup/lookup.go Normal file
View file

@ -0,0 +1,156 @@
package lookup
import (
"github.com/cyphar/filepath-securejoin"
"github.com/opencontainers/runc/libcontainer/user"
"github.com/sirupsen/logrus"
"strconv"
)
const (
etcpasswd = "/etc/passwd"
etcgroup = "/etc/group"
)
// Overrides allows you to override defaults in GetUserGroupInfo
type Overrides struct {
DefaultUser *user.ExecUser
ContainerEtcPasswdPath string
ContainerEtcGroupPath string
}
// GetUserGroupInfo takes string forms of the the container's mount path and the container user and
// returns a ExecUser with uid, gid, sgids, and home. And override can be provided for defaults.
func GetUserGroupInfo(containerMount, containerUser string, override *Overrides) (*user.ExecUser, error) {
var (
passwdDest, groupDest string
defaultExecUser *user.ExecUser
err error
)
passwdPath := etcpasswd
groupPath := etcgroup
if override != nil {
// Check for an override /etc/passwd path
if override.ContainerEtcPasswdPath != "" {
passwdPath = override.ContainerEtcPasswdPath
}
// Check for an override for /etc/group path
if override.ContainerEtcGroupPath != "" {
groupPath = override.ContainerEtcGroupPath
}
}
// Check for an override default user
if override != nil && override.DefaultUser != nil {
defaultExecUser = override.DefaultUser
} else {
// Define a default container user
//defaultExecUser = &user.ExecUser{
// Uid: 0,
// Gid: 0,
// Home: "/",
defaultExecUser = nil
}
// Make sure the /etc/group and /etc/passwd destinations are not a symlink to something naughty
if passwdDest, err = securejoin.SecureJoin(containerMount, passwdPath); err != nil {
logrus.Debug(err)
return nil, err
}
if groupDest, err = securejoin.SecureJoin(containerMount, groupPath); err != nil {
logrus.Debug(err)
return nil, err
}
return user.GetExecUserPath(containerUser, defaultExecUser, passwdDest, groupDest)
}
// GetContainerGroups uses securejoin to get a list of numerical groupids from a container. Per the runc
// function it calls: If a group name cannot be found, an error will be returned. If a group id cannot be found,
// or the given group data is nil, the id will be returned as-is provided it is in the legal range.
func GetContainerGroups(groups []string, containerMount string, override *Overrides) ([]uint32, error) {
var (
groupDest string
err error
uintgids []uint32
)
groupPath := etcgroup
if override != nil && override.ContainerEtcGroupPath != "" {
groupPath = override.ContainerEtcGroupPath
}
if groupDest, err = securejoin.SecureJoin(containerMount, groupPath); err != nil {
logrus.Debug(err)
return nil, err
}
gids, err := user.GetAdditionalGroupsPath(groups, groupDest)
if err != nil {
return nil, err
}
// For libpod, we want []uint32s
for _, gid := range gids {
uintgids = append(uintgids, uint32(gid))
}
return uintgids, nil
}
// GetUser takes a containermount path and user name or id and returns
// a matching User structure from /etc/passwd. If it cannot locate a user
// with the provided information, an ErrNoPasswdEntries is returned.
func GetUser(containerMount, userIDorName string) (*user.User, error) {
var inputIsName bool
uid, err := strconv.Atoi(userIDorName)
if err != nil {
inputIsName = true
}
passwdDest, err := securejoin.SecureJoin(containerMount, etcpasswd)
if err != nil {
return nil, err
}
users, err := user.ParsePasswdFileFilter(passwdDest, func(u user.User) bool {
if inputIsName {
return u.Name == userIDorName
}
return u.Uid == uid
})
if err != nil {
return nil, err
}
if len(users) > 0 {
return &users[0], nil
}
return nil, user.ErrNoPasswdEntries
}
// GetGroup takes ac ontainermount path and a group name or id and returns
// a match Group struct from /etc/group. if it cannot locate a group,
// an ErrNoGroupEntries error is returned.
func GetGroup(containerMount, groupIDorName string) (*user.Group, error) {
var inputIsName bool
gid, err := strconv.Atoi(groupIDorName)
if err != nil {
inputIsName = true
}
groupDest, err := securejoin.SecureJoin(containerMount, etcgroup)
if err != nil {
return nil, err
}
groups, err := user.ParseGroupFileFilter(groupDest, func(g user.Group) bool {
if inputIsName {
return g.Name == groupIDorName
}
return g.Gid == gid
})
if err != nil {
return nil, err
}
if len(groups) > 0 {
return &groups[0], nil
}
return nil, user.ErrNoGroupEntries
}