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server/auth: protect rangePermCache with a RW lock
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Signed-off-by: Hitoshi Mitake <[email protected]>
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@mitake
mitake committed Jul 19, 2022
1 parent 3237289 commit e15c005
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Showing 3 changed files with 142 additions and 44 deletions.
50 changes: 32 additions & 18 deletions server/auth/range_perm_cache.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -105,34 +105,48 @@ func checkKeyPoint(lg *zap.Logger, cachedPerms *unifiedRangePermissions, key []b
return false
}

func (as *authStore) isRangeOpPermitted(tx backend.ReadTx, userName string, key, rangeEnd []byte, permtyp authpb.Permission_Type) bool {
// assumption: tx is Lock()ed
_, ok := as.rangePermCache[userName]
func (as *authStore) isRangeOpPermitted(userName string, key, rangeEnd []byte, permtyp authpb.Permission_Type) bool {
as.rangePermCacheMu.RLock()
defer as.rangePermCacheMu.RUnlock()

rangePerm, ok := as.rangePermCache[userName]
if !ok {
perms := getMergedPerms(as.lg, tx, userName)
if perms == nil {
as.lg.Error(
"failed to create a merged permission",
zap.String("user-name", userName),
)
return false
}
as.rangePermCache[userName] = perms
as.lg.Error(
"user doesn't exist",
zap.String("user-name", userName),
)
return false
}

if len(rangeEnd) == 0 {
return checkKeyPoint(as.lg, as.rangePermCache[userName], key, permtyp)
return checkKeyPoint(as.lg, rangePerm, key, permtyp)
}

return checkKeyInterval(as.lg, as.rangePermCache[userName], key, rangeEnd, permtyp)
return checkKeyInterval(as.lg, rangePerm, key, rangeEnd, permtyp)
}

func (as *authStore) clearCachedPerm() {
func (as *authStore) refreshRangePermCache(tx backend.ReadTx) {
// Note that every authentication configuration update calls this method and it invalidates the entire
// rangePermCache and reconstruct it based on information of users and roles stored in the backend.
// This can be a costly operation.
as.rangePermCacheMu.Lock()
defer as.rangePermCacheMu.Unlock()

as.rangePermCache = make(map[string]*unifiedRangePermissions)
}

func (as *authStore) invalidateCachedPerm(userName string) {
delete(as.rangePermCache, userName)
users := getAllUsers(as.lg, tx)
for _, user := range users {
userName := string(user.Name)
perms := getMergedPerms(as.lg, tx, userName)
if perms == nil {
as.lg.Error(
"failed to create a merged permission",
zap.String("user-name", userName),
)
continue
}
as.rangePermCache[userName] = perms
}
}

type unifiedRangePermissions struct {
Expand Down
46 changes: 27 additions & 19 deletions server/auth/store.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -208,7 +208,14 @@ type authStore struct {
enabled bool
enabledMu sync.RWMutex

rangePermCache map[string]*unifiedRangePermissions // username -> unifiedRangePermissions
// rangePermCache needs to be protected by rangePermCacheMu
// rangePermCacheMu needs to be write locked only in initialization phase or configuration changes
// Hot paths like Range(), needs to acquire read lock for improving performance
//
// Note that BatchTx and ReadTx cannot be a mutex for rangePermCache because they are independent resources
// see also: https://github.com/etcd-io/etcd/pull/13920#discussion_r849114855
rangePermCache map[string]*unifiedRangePermissions // username -> unifiedRangePermissions
rangePermCacheMu sync.RWMutex

tokenProvider TokenProvider
bcryptCost int // the algorithm cost / strength for hashing auth passwords
Expand Down Expand Up @@ -243,7 +250,7 @@ func (as *authStore) AuthEnable() error {
as.enabled = true
as.tokenProvider.enable()

as.rangePermCache = make(map[string]*unifiedRangePermissions)
as.refreshRangePermCache(tx)

as.setRevision(getRevision(tx))

Expand Down Expand Up @@ -422,6 +429,7 @@ func (as *authStore) UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse,
putUser(as.lg, tx, newUser)

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.lg.Info("added a user", zap.String("user-name", r.Name))
return &pb.AuthUserAddResponse{}, nil
Expand All @@ -445,8 +453,8 @@ func (as *authStore) UserDelete(r *pb.AuthUserDeleteRequest) (*pb.AuthUserDelete
delUser(tx, r.Name)

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.invalidateCachedPerm(r.Name)
as.tokenProvider.invalidateUser(r.Name)

as.lg.Info(
Expand Down Expand Up @@ -487,8 +495,8 @@ func (as *authStore) UserChangePassword(r *pb.AuthUserChangePasswordRequest) (*p
putUser(as.lg, tx, updatedUser)

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.invalidateCachedPerm(r.Name)
as.tokenProvider.invalidateUser(r.Name)

as.lg.Info(
Expand Down Expand Up @@ -532,9 +540,8 @@ func (as *authStore) UserGrantRole(r *pb.AuthUserGrantRoleRequest) (*pb.AuthUser

putUser(as.lg, tx, user)

as.invalidateCachedPerm(r.User)

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.lg.Info(
"granted a role to a user",
Expand Down Expand Up @@ -610,9 +617,8 @@ func (as *authStore) UserRevokeRole(r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUs

putUser(as.lg, tx, updatedUser)

as.invalidateCachedPerm(r.Name)

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.lg.Info(
"revoked a role from a user",
Expand Down Expand Up @@ -678,11 +684,8 @@ func (as *authStore) RoleRevokePermission(r *pb.AuthRoleRevokePermissionRequest)

putRole(as.lg, tx, updatedRole)

// TODO(mitake): currently single role update invalidates every cache
// It should be optimized.
as.clearCachedPerm()

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.lg.Info(
"revoked a permission on range",
Expand Down Expand Up @@ -730,10 +733,10 @@ func (as *authStore) RoleDelete(r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDelete

putUser(as.lg, tx, updatedUser)

as.invalidateCachedPerm(string(user.Name))
}

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.lg.Info("deleted a role", zap.String("role-name", r.Role))
return &pb.AuthRoleDeleteResponse{}, nil
Expand Down Expand Up @@ -818,11 +821,8 @@ func (as *authStore) RoleGrantPermission(r *pb.AuthRoleGrantPermissionRequest) (

putRole(as.lg, tx, role)

// TODO(mitake): currently single role update invalidates every cache
// It should be optimized.
as.clearCachedPerm()

as.commitRevision(tx)
as.refreshRangePermCache(tx)

as.lg.Info(
"granted/updated a permission to a user",
Expand Down Expand Up @@ -867,7 +867,7 @@ func (as *authStore) isOpPermitted(userName string, revision uint64, key, rangeE
return nil
}

if as.isRangeOpPermitted(tx, userName, key, rangeEnd, permTyp) {
if as.isRangeOpPermitted(userName, key, rangeEnd, permTyp) {
return nil
}

Expand Down Expand Up @@ -929,7 +929,15 @@ func getUser(lg *zap.Logger, tx backend.ReadTx, username string) *authpb.User {
}

func getAllUsers(lg *zap.Logger, tx backend.ReadTx) []*authpb.User {
_, vs := tx.UnsafeRange(buckets.AuthUsers, []byte{0}, []byte{0xff}, -1)
var vs [][]byte
err := tx.UnsafeForEach(buckets.AuthUsers, func(k []byte, v []byte) error {
vs = append(vs, v)
return nil
})
if err != nil {
lg.Panic("failed to get users",
zap.Error(err))
}
if len(vs) == 0 {
return nil
}
Expand Down
90 changes: 83 additions & 7 deletions server/auth/store_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ import (
"go.etcd.io/etcd/api/v3/authpb"
pb "go.etcd.io/etcd/api/v3/etcdserverpb"
"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
"go.etcd.io/etcd/pkg/v3/adt"
"go.etcd.io/etcd/server/v3/mvcc/backend"
betesting "go.etcd.io/etcd/server/v3/mvcc/backend/testing"

Expand Down Expand Up @@ -153,7 +154,8 @@ func TestUserAdd(t *testing.T) {
as, tearDown := setupAuthStore(t)
defer tearDown(t)

ua := &pb.AuthUserAddRequest{Name: "foo", Options: &authpb.UserAddOptions{NoPassword: false}}
const userName = "foo"
ua := &pb.AuthUserAddRequest{Name: userName, Options: &authpb.UserAddOptions{NoPassword: false}}
_, err := as.UserAdd(ua) // add an existing user
if err == nil {
t.Fatalf("expected %v, got %v", ErrUserAlreadyExist, err)
Expand All @@ -167,6 +169,11 @@ func TestUserAdd(t *testing.T) {
if err != ErrUserEmpty {
t.Fatal(err)
}

if _, ok := as.rangePermCache[userName]; !ok {
t.Fatalf("user %s should be added but it doesn't exist in rangePermCache", userName)

}
}

func TestRecover(t *testing.T) {
Expand Down Expand Up @@ -216,7 +223,8 @@ func TestUserDelete(t *testing.T) {
defer tearDown(t)

// delete an existing user
ud := &pb.AuthUserDeleteRequest{Name: "foo"}
const userName = "foo"
ud := &pb.AuthUserDeleteRequest{Name: userName}
_, err := as.UserDelete(ud)
if err != nil {
t.Fatal(err)
Expand All @@ -230,6 +238,47 @@ func TestUserDelete(t *testing.T) {
if err != ErrUserNotFound {
t.Fatalf("expected %v, got %v", ErrUserNotFound, err)
}

if _, ok := as.rangePermCache[userName]; ok {
t.Fatalf("user %s should be deleted but it exists in rangePermCache", userName)

}
}

func TestUserDeleteAndPermCache(t *testing.T) {
as, tearDown := setupAuthStore(t)
defer tearDown(t)

// delete an existing user
const deletedUserName = "foo"
ud := &pb.AuthUserDeleteRequest{Name: deletedUserName}
_, err := as.UserDelete(ud)
if err != nil {
t.Fatal(err)
}

// delete a non-existing user
_, err = as.UserDelete(ud)
if err != ErrUserNotFound {
t.Fatalf("expected %v, got %v", ErrUserNotFound, err)
}

if _, ok := as.rangePermCache[deletedUserName]; ok {
t.Fatalf("user %s should be deleted but it exists in rangePermCache", deletedUserName)
}

// add a new user
const newUser = "bar"
ua := &pb.AuthUserAddRequest{Name: newUser, HashedPassword: encodePassword("pwd1"), Options: &authpb.UserAddOptions{NoPassword: false}}
_, err = as.UserAdd(ua)
if err != nil {
t.Fatal(err)
}

if _, ok := as.rangePermCache[newUser]; !ok {
t.Fatalf("user %s should exist but it doesn't exist in rangePermCache", deletedUserName)

}
}

func TestUserChangePassword(t *testing.T) {
Expand Down Expand Up @@ -524,17 +573,44 @@ func TestUserRevokePermission(t *testing.T) {
t.Fatal(err)
}

_, err = as.UserGrantRole(&pb.AuthUserGrantRoleRequest{User: "foo", Role: "role-test"})
const userName = "foo"
_, err = as.UserGrantRole(&pb.AuthUserGrantRoleRequest{User: userName, Role: "role-test"})
if err != nil {
t.Fatal(err)
}

_, err = as.UserGrantRole(&pb.AuthUserGrantRoleRequest{User: "foo", Role: "role-test-1"})
_, err = as.UserGrantRole(&pb.AuthUserGrantRoleRequest{User: userName, Role: "role-test-1"})
if err != nil {
t.Fatal(err)
}

u, err := as.UserGet(&pb.AuthUserGetRequest{Name: "foo"})
perm := &authpb.Permission{
PermType: authpb.WRITE,
Key: []byte("WriteKeyBegin"),
RangeEnd: []byte("WriteKeyEnd"),
}
_, err = as.RoleGrantPermission(&pb.AuthRoleGrantPermissionRequest{
Name: "role-test-1",
Perm: perm,
})
if err != nil {
t.Fatal(err)
}

if _, ok := as.rangePermCache[userName]; !ok {
t.Fatalf("User %s should have its entry in rangePermCache", userName)
}
unifiedPerm := as.rangePermCache[userName]
pt1 := adt.NewBytesAffinePoint([]byte("WriteKeyBegin"))
if !unifiedPerm.writePerms.Contains(pt1) {
t.Fatal("rangePermCache should contain WriteKeyBegin")
}
pt2 := adt.NewBytesAffinePoint([]byte("OutOfRange"))
if unifiedPerm.writePerms.Contains(pt2) {
t.Fatal("rangePermCache should not contain OutOfRange")
}

u, err := as.UserGet(&pb.AuthUserGetRequest{Name: userName})
if err != nil {
t.Fatal(err)
}
Expand All @@ -544,12 +620,12 @@ func TestUserRevokePermission(t *testing.T) {
t.Fatalf("expected %v, got %v", expected, u.Roles)
}

_, err = as.UserRevokeRole(&pb.AuthUserRevokeRoleRequest{Name: "foo", Role: "role-test-1"})
_, err = as.UserRevokeRole(&pb.AuthUserRevokeRoleRequest{Name: userName, Role: "role-test-1"})
if err != nil {
t.Fatal(err)
}

u, err = as.UserGet(&pb.AuthUserGetRequest{Name: "foo"})
u, err = as.UserGet(&pb.AuthUserGetRequest{Name: userName})
if err != nil {
t.Fatal(err)
}
Expand Down

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