Integrate with QEMU monitor to provide encryption passphrase when
starting a guest using encrypted qcow volumes
* src/qemu_driver.c (findDomainDiskEncryption,
findVolumeQcowPassphrase,
qemudMonitorSendVolumePassphrase, qemudMonitorSendCont): Send a volume
passphrase if qemu asks for it.
If the <encryption format='qcow'> element does not specify a secret
during volume creation, generate a suitable secret and add it to the
<encryption> tag. The caller can view the updated <encryption> tag
using virStorageVolGetXMLDesc().
Similarly, when <encryption format='default'/> is specified while
creating a qcow or qcow2-formatted volume, change the format to "qcow"
and generate a secret as described above.
* src/storage_encryption_conf.h (VIR_STORAGE_QCOW_PASSPHRASE_SIZE,
virStorageGenerateQcowPasphrase),
src/storage_encryption_conf.c (virStorageGenerateQcowPasphrase),
src/libvirt_private.syms: Add virStorageGenerateQcowPasphrase().
* src/storage_backend.c (virStoragegenerateQcowEncryption,
virStorageBackendCreateQemuImg): Generate a passphrase and
<encryption> when creating a qcow-formatted encrypted volume and the
user did not supply the information.
This implementation stores the secrets in an unencrypted text file,
for simplicity in implementation and debugging.
(Symmetric encryption, e.g. using gpgme, will not be difficult to add.
Because the TLS private key used by libvirtd is stored unencrypted,
encrypting the secrets file does not currently provide much additional
security.)
* include/libvirt/virterror.h, src/virterror.c (VIR_ERR_NO_SECRET): New
error number.
* po/POTFILES.in, src/Makefile.am: Add secret_driver.
* bootstrap: Use gnulib's base64 module.
* src/secret_driver.c, src.secret_driver.h, src/libvirt_private.syms:
Add local secret driver.
* qemud/qemud.c (qemudInitialize): Use the local secret driver.
Add a <secret> XML handling API, separate from the local driver, to
avoid manually generating XML in other parts of libvirt.
* src/secret_conf.c, src/secret_conf.h: New files.
* po/POTFILES.in, src/Makefile.am: Add secret_conf.
Add a VIR_SECRET_GET_VALUE_INTERNAL_CALL flag value, replacing the
originally separate libvirt_internal_call parameter. The flag is used
to differentiate external virSecretGetValue() calls from internal calls
by libvirt drivers that need to use the secret even if it is private.
* src/libvirt_internal.h Remove VIR_DOMAIN_XML_FLAGS_MASK
* src/driver.h Add VIR_SECRET_GET_VALUE_FLAGS_MASK constant and
VIR_SECRET_GET_VALUE_INTERNAL_CALL. Re-add the
VIR_DOMAIN_XML_FLAGS_MASK constant
* src/libvirt.c (virSecretGetValue): Don't allow the user to specify
internal flags.
The interface allows qemudMonitorSendCont() to report errors that are
not overridden by its callers.
Also fix a potential infinite loop in qemuDomainCoreDump() if sending
cont repeatedly fails.
* src/qemu_driver.c (qemudMonitorSendCont): New function.
(qemudAutostartConfigs): Reset error before each call to
qemudStartVMDaemon().
(qemudInitCpus, qemudDomainResume, qemudDomainCoreDump,
qemudDomainRestore, qemudDomainMigratePerform,
qemudDomainMigrateFinish2): Use qemudMonitorSendCont().
The if ((nlptr...)) implicitly assumes commptr != NULL (and that "buf"
starts with "cmd"). Make the assumption explicit, it will be broken in
a future patch.
* src/qemu_driver.c: Don't assume buffered monitor output echoes the
command.
The XML allows <encryption format='unencrypted'/>, this implementation
canonicalizes the internal representation so that "disk->encryption" is
non-NULL iff encryption information is available.
A domain with partial encryption information can be defined,
completeness of the information is not verified. The domain won't
start until the remaining information is added, of course.
* docs/formatdomain.html, docs/formatdomain.html.in: Document
new encryption options for disks
* docs/schemas/domain.rng: Pull in storage encryption schema
rules
* src/domain_conf.h, src/domain_conf.c: Wire up storage encryption
XML parsing/formatting APIs
Supports only virStorageVolCreateXML, not virStorageVolCreateXMLFrom.
Curiously, qemu-img does not need the passphrase for anything to create
an encrypted volume. This implementation thus does not need to touch
any secrets to work with cooperating clients. More generic passphrase
handling is added in the next patch.
* src/storage_backend.c: Request encryption when creating qcow/qcow2
files
* src/storage_backend_disk.c, src/storage_backend_fs.c,
src/storage_backend_logical.c: Refuse to create volumes with
encryption params set.
(The implementation is not very generic, but that can be very
easily rectified if/when new encryption formats appear.)
* src/storage_backend_fs.c: Probe for qcow/qcow2 encryption
algorithm field
The XML allows <encryption format='unencrypted'/>, this implementation
canonicalizes the internal representation so that "vol->encryption" is
non-NULL iff the volume is encrypted.
Note that partial encryption information (e.g. specifying an encryption
format, but not the key/passphrase) is valid, libvirt will automatically
choose value for the missing information during volume creation. The
user can read the volume XML, and use the unmodified <encryption> tag in
future operations (without having to be able to understand) its contents.
* docs/formatstorage.html, docs/formatstorage.html.in: Document
storage volume encryption options
* src/storage_conf.c, src/storage_conf.h: Hook up storage
encryption XML handling
* tests/storagevolschemadata/vol-qcow2.xml: Test case for encryption
schema changes
Define an <encryption> tag specifying volume encryption format and
format-depenedent parameters (e.g. passphrase, cipher name, key
length, key).
Currently the only defined parameter is a reference to a "secret"
(passphrase/key) managed using the virSecret* API.
Only the qcow/qcow2 encryption format, and a "default" format used to
let libvirt choose the format during volume creation, is currently
supported.
This patch does not add any users; the <encryption> tag is added in
the following patches to both volumes (to support encrypted volume
creation) and domains.
* docs/*.html: Re-generate
* docs/formatstorageencryption.html.in, docs/sitemap.html.in:
Add page describing storage encryption data format
* docs/schemas/Makefile.am, docs/schemas/storageencryption.rng:
Add RNG schema for storage encryption format
* po/POTFILES.in: Add src/storage_encryption_conf.c
* src/libvirt_private.syms: Export virStorageEncryption* functions
* src/storage_encryption_conf.h, src/storage_encryption_conf.c: Internal
helper APIs for dealing with storage encryption format
* libvirt.spec.in, mingw32-libvirt.spec.in: Add storageencryption.rng
RNG schema
* include/libvirt/virterror.h, src/virterror.c: Add VIR_WAR_NO_SECRET
* src/libvirt_private.syms, src/datatypes.h, src/datatypes.c: Type
virSecret struct definition and helper APIs
* src/driver.h: Sub-driver API definitions for secrets
* src/libvirt.c: Define new sub-driver for secrets
This patch adds a "secret" as a separately managed object, using a
special-purpose API to transfer the secret values between nodes and
libvirt users.
* docs/schemas/secret.rng, docs/schemas/Makefilem.am: Add new
schema for virSecret objects
* docs/*html: Re-generated
* docs/formatsecret.html.in, docs/sitemap.html.in: Add page
describing the virSecret XML schema
* include/libvirt/libvirt.h.in: Define the new virSecret public
API
* src/libvirt_public.syms: Export symbols for new public APIs
* mingw32-libvirt.spec.in, libvirt.spec.in: Add secret.rng to
files list
Miloslav Trmač