zrepl/daemon/job/build_jobs_sendrecvoptions.go
Christian Schwarz fb6a9be954 fix encrypt-on-receive with placeholders
fixes https://github.com/zrepl/zrepl/issues/504

Problem:
  plain send + recv with root_fs encrypted + placeholders causes plain recvs
  whereas user would expect encrypt-on-recv
Reason:
  We create placeholder filesytems with -o encryption=off.
  Thus, children received below those placeholders won't inherit
  encryption of root_fs.
Fix:
  We'll have three values for `recv.placeholders.encryption: unspecified (default) | off | inherit`.
  When we create a placeholder, we will fail the operation if  `recv.placeholders.encryption = unspecified`.
  The exception is if the placeholder filesystem is to encode the client identity ($root_fs/$client_identity) in a pull job.
  Those are created in `inherit` mode if the config field is `unspecified` so that users who don't need
  placeholders are not bothered by these details.

Future Work:
  Automatically warn existing users of encrypt-on-recv about the problem
  if they are affected.
  The problem that I hit during implementation of this is that the
  `encryption` prop's `source` doesn't quite behave like other props:
  `source` is `default` for `encryption=off` and `-` when `encryption=on`.
  Hence, we can't use `source` to distinguish the following 2x2 cases:
  (1) placeholder created with explicit -o encryption=off
  (2) placeholder created without specifying -o encryption
  with
  (A) an encrypted parent at creation time
  (B) an unencrypted parent at creation time
2021-12-18 15:12:47 +01:00

103 lines
3.0 KiB
Go

package job
import (
"github.com/pkg/errors"
"github.com/zrepl/zrepl/config"
"github.com/zrepl/zrepl/daemon/filters"
"github.com/zrepl/zrepl/endpoint"
"github.com/zrepl/zrepl/util/nodefault"
"github.com/zrepl/zrepl/zfs"
)
type SendingJobConfig interface {
GetFilesystems() config.FilesystemsFilter
GetSendOptions() *config.SendOptions // must not be nil
}
func buildSenderConfig(in SendingJobConfig, jobID endpoint.JobID) (*endpoint.SenderConfig, error) {
fsf, err := filters.DatasetMapFilterFromConfig(in.GetFilesystems())
if err != nil {
return nil, errors.Wrap(err, "cannot build filesystem filter")
}
sendOpts := in.GetSendOptions()
bwlim, err := buildBandwidthLimitConfig(sendOpts.BandwidthLimit)
if err != nil {
return nil, errors.Wrap(err, "cannot build bandwith limit config")
}
sc := &endpoint.SenderConfig{
FSF: fsf,
JobID: jobID,
Encrypt: &nodefault.Bool{B: sendOpts.Encrypted},
SendRaw: sendOpts.Raw,
SendProperties: sendOpts.SendProperties,
SendBackupProperties: sendOpts.BackupProperties,
SendLargeBlocks: sendOpts.LargeBlocks,
SendCompressed: sendOpts.Compressed,
SendEmbeddedData: sendOpts.EmbeddedData,
SendSaved: sendOpts.Saved,
BandwidthLimit: bwlim,
}
if err := sc.Validate(); err != nil {
return nil, errors.Wrap(err, "cannot build sender config")
}
return sc, nil
}
type ReceivingJobConfig interface {
GetRootFS() string
GetAppendClientIdentity() bool
GetRecvOptions() *config.RecvOptions
}
func buildReceiverConfig(in ReceivingJobConfig, jobID endpoint.JobID) (rc endpoint.ReceiverConfig, err error) {
rootFs, err := zfs.NewDatasetPath(in.GetRootFS())
if err != nil {
return rc, errors.New("root_fs is not a valid zfs filesystem path")
}
if rootFs.Length() <= 0 {
return rc, errors.New("root_fs must not be empty") // duplicates error check of receiver
}
recvOpts := in.GetRecvOptions()
bwlim, err := buildBandwidthLimitConfig(recvOpts.BandwidthLimit)
if err != nil {
return rc, errors.Wrap(err, "cannot build bandwith limit config")
}
placeholderEncryption, err := endpoint.PlaceholderCreationEncryptionPropertyString(recvOpts.Placeholder.Encryption)
if err != nil {
options := []string{}
for _, v := range endpoint.PlaceholderCreationEncryptionPropertyValues() {
options = append(options, endpoint.PlaceholderCreationEncryptionProperty(v).String())
}
return rc, errors.Errorf("placeholder encryption value %q is invalid, must be one of %s",
recvOpts.Placeholder.Encryption, options)
}
rc = endpoint.ReceiverConfig{
JobID: jobID,
RootWithoutClientComponent: rootFs,
AppendClientIdentity: in.GetAppendClientIdentity(),
InheritProperties: recvOpts.Properties.Inherit,
OverrideProperties: recvOpts.Properties.Override,
BandwidthLimit: bwlim,
PlaceholderEncryption: placeholderEncryption,
}
if err := rc.Validate(); err != nil {
return rc, errors.Wrap(err, "cannot build receiver config")
}
return rc, nil
}