Re: [Qemu-devel] [PATCH for 2.9] migration: use "" as the default for tls-creds/hostname

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Daniel P. Berrange (berrange@redhat.com) wrote:
> The tls-creds parameter has a default value of NULL indicating
> that TLS should not be used. Setting it to non-NULL enables
> use of TLS. Once tls-creds are set to a non-NULL value via the
> monitor, it isn't possible to set them back to NULL again, due
> to current implementation limitations. The empty string is not
> a valid QObject identifier, so this switches to use "" as the
> default, indicating that TLS will not be used
> 
> The tls-hostname parameter has a default value of NULL indicating
> the the hostname from the migrate connection URI should be used.
> Again, once tls-hostname is set non-NULL, to override the default
> hostname for x509 cert validation, it isn't possible to reset it
> back to NULL via the monitor. The empty string is not a valid
> hostname, so this switches to use "" as the default, indicating
> that the migrate URI hostname should be used.
> 
> Using "" as the default for both, also means that the monitor
> commands "info migrate_parameters" / "query-migrate-parameters"
> will report existance of tls-creds/tls-parameters even when set
> to their default values.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Yes, simple enough.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Markus, Eric - are you OK with that?

Dave


> ---
>  migration/migration.c | 4 ++++
>  migration/tls.c       | 2 +-
>  qapi-schema.json      | 4 ++++
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 3dab684..54060f7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -110,6 +110,8 @@ MigrationState *migrate_get_current(void)
>  
>      if (!once) {
>          qemu_mutex_init(&current_migration.src_page_req_mutex);
> +        current_migration.parameters.tls_creds = g_strdup("");
> +        current_migration.parameters.tls_hostname = g_strdup("");
>          once = true;
>      }
>      return &current_migration;
> @@ -458,6 +460,7 @@ void migration_channel_process_incoming(MigrationState *s,
>          ioc, object_get_typename(OBJECT(ioc)));
>  
>      if (s->parameters.tls_creds &&
> +        *s->parameters.tls_creds &&
>          !object_dynamic_cast(OBJECT(ioc),
>                               TYPE_QIO_CHANNEL_TLS)) {
>          Error *local_err = NULL;
> @@ -480,6 +483,7 @@ void migration_channel_connect(MigrationState *s,
>          ioc, object_get_typename(OBJECT(ioc)), hostname);
>  
>      if (s->parameters.tls_creds &&
> +        *s->parameters.tls_creds &&
>          !object_dynamic_cast(OBJECT(ioc),
>                               TYPE_QIO_CHANNEL_TLS)) {
>          Error *local_err = NULL;
> diff --git a/migration/tls.c b/migration/tls.c
> index 203c11d..45bec44 100644
> --- a/migration/tls.c
> +++ b/migration/tls.c
> @@ -141,7 +141,7 @@ void migration_tls_channel_connect(MigrationState *s,
>          return;
>      }
>  
> -    if (s->parameters.tls_hostname) {
> +    if (s->parameters.tls_hostname && *s->parameters.tls_hostname) {
>          hostname = s->parameters.tls_hostname;
>      }
>      if (!hostname) {
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 32b4a4b..eb9bf67 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1036,6 +1036,8 @@
>  #             credentials must be for a 'server' endpoint. Setting this
>  #             will enable TLS for all migrations. The default is unset,
>  #             resulting in unsecured migration at the QEMU level. (Since 2.7)
> +#             An empty string means that QEMU will use plain text mode for
> +#             migration, rather than TLS (Since 2.9)
>  #
>  # @tls-hostname: #optional hostname of the target host for the migration. This
>  #                is required when using x509 based TLS credentials and the
> @@ -1043,6 +1045,8 @@
>  #                example if using fd: or exec: based migration, the
>  #                hostname must be provided so that the server's x509
>  #                certificate identity can be validated. (Since 2.7)
> +#                An empty string means that QEMU will use the hostname
> +#                associated with the migration URI, if any. (Since 2.9)
>  #
>  # @max-bandwidth: to set maximum speed for migration. maximum speed in
>  #                 bytes per second. (Since 2.8)
> -- 
> 2.9.3
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK