[Qemu-devel] [PATCH v4 25/28] migration: define 'tls-creds' and 'tls-hostname' migration parameters

["Daniel P. Berrange" <berrange@redhat.com>]

Define two new migration parameters to be used with TLS encryption.
The 'tls-creds' parameter provides the ID of an instance of the
'tls-creds' object type, or rather a subclass such as 'tls-creds-x509'.
Providing these credentials will enable use of TLS on the migration
data stream.

If using x509 certificates, together with a migration URI that does
not include a hostname, the 'tls-hostname' parameter provides the
hostname to use when verifying the server's x509 certificate. This
allows TLS to be used in combination with fd: and exec: protocols
where a TCP connection is established by a 3rd party outside of
QEMU.

NB, this requires changing the migrate_set_parameter method in the
HMP to accept a 's' (string) value instead of 'i' (integer). This
is backwards compatible, because the parsing of strings allows the
quotes to be optional, thus any integer is also a valid string.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 hmp-commands.hx       |  2 +-
 hmp.c                 | 36 ++++++++++++++++++++++++++------
 migration/migration.c | 14 +++++++++++++
 qapi-schema.json      | 58 ++++++++++++++++++++++++++++++++++++++++++++++++---
 4 files changed, 100 insertions(+), 10 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 664d794..47939b5 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1008,7 +1008,7 @@ ETEXI
 
     {
         .name       = "migrate_set_parameter",
-        .args_type  = "parameter:s,value:i",
+        .args_type  = "parameter:s,value:s",
         .params     = "parameter value",
         .help       = "Set the parameter for migration",
         .mhandler.cmd = hmp_migrate_set_parameter,
diff --git a/hmp.c b/hmp.c
index 7126f17..885b514 100644
--- a/hmp.c
+++ b/hmp.c
@@ -293,6 +293,12 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, " %s: %" PRId64,
             MigrationParameter_lookup[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT],
             params->x_cpu_throttle_increment);
+        monitor_printf(mon, " %s: '%s'",
+            MigrationParameter_lookup[MIGRATION_PARAMETER_TLS_CREDS],
+            params->tls_creds ? : "");
+        monitor_printf(mon, " %s: '%s'",
+            MigrationParameter_lookup[MIGRATION_PARAMETER_TLS_HOSTNAME],
+            params->tls_hostname ? : "");
         monitor_printf(mon, "\n");
     }
 
@@ -1242,13 +1248,16 @@ void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict)
 void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
 {
     const char *param = qdict_get_str(qdict, "parameter");
-    int value = qdict_get_int(qdict, "value");
+    int valueint = 0;
+    const char *valuestr = NULL;
     Error *err = NULL;
     bool has_compress_level = false;
     bool has_compress_threads = false;
     bool has_decompress_threads = false;
     bool has_x_cpu_throttle_initial = false;
     bool has_x_cpu_throttle_increment = false;
+    bool has_tls_creds = false;
+    bool has_tls_hostname = false;
     int i;
 
     for (i = 0; i < MIGRATION_PARAMETER__MAX; i++) {
@@ -1256,25 +1265,40 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
             switch (i) {
             case MIGRATION_PARAMETER_COMPRESS_LEVEL:
                 has_compress_level = true;
+                valueint = qdict_get_int(qdict, "value");
                 break;
             case MIGRATION_PARAMETER_COMPRESS_THREADS:
                 has_compress_threads = true;
+                valueint = qdict_get_int(qdict, "value");
                 break;
             case MIGRATION_PARAMETER_DECOMPRESS_THREADS:
                 has_decompress_threads = true;
+                valueint = qdict_get_int(qdict, "value");
                 break;
             case MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL:
                 has_x_cpu_throttle_initial = true;
+                valueint = qdict_get_int(qdict, "value");
                 break;
             case MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT:
                 has_x_cpu_throttle_increment = true;
+                valueint = qdict_get_int(qdict, "value");
+                break;
+            case MIGRATION_PARAMETER_TLS_CREDS:
+                has_tls_creds = true;
+                valuestr = qdict_get_str(qdict, "value");
+                break;
+            case MIGRATION_PARAMETER_TLS_HOSTNAME:
+                has_tls_hostname = true;
+                valuestr = qdict_get_str(qdict, "value");
                 break;
             }
-            qmp_migrate_set_parameters(has_compress_level, value,
-                                       has_compress_threads, value,
-                                       has_decompress_threads, value,
-                                       has_x_cpu_throttle_initial, value,
-                                       has_x_cpu_throttle_increment, value,
+            qmp_migrate_set_parameters(has_compress_level, valueint,
+                                       has_compress_threads, valueint,
+                                       has_decompress_threads, valueint,
+                                       has_x_cpu_throttle_initial, valueint,
+                                       has_x_cpu_throttle_increment, valueint,
+                                       has_tls_creds, valuestr,
+                                       has_tls_hostname, valuestr,
                                        &err);
             break;
         }
diff --git a/migration/migration.c b/migration/migration.c
index a056bcd..378041e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -537,6 +537,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->decompress_threads = s->parameters.decompress_threads;
     params->x_cpu_throttle_initial = s->parameters.x_cpu_throttle_initial;
     params->x_cpu_throttle_increment = s->parameters.x_cpu_throttle_increment;
+    params->tls_creds = g_strdup(s->parameters.tls_creds);
+    params->tls_hostname = g_strdup(s->parameters.tls_hostname);
 
     return params;
 }
@@ -738,6 +740,10 @@ void qmp_migrate_set_parameters(bool has_compress_level,
                                 int64_t x_cpu_throttle_initial,
                                 bool has_x_cpu_throttle_increment,
                                 int64_t x_cpu_throttle_increment,
+                                bool has_tls_creds,
+                                const char *tls_creds,
+                                bool has_tls_hostname,
+                                const char *tls_hostname,
                                 Error **errp)
 {
     MigrationState *s = migrate_get_current();
@@ -789,6 +795,14 @@ void qmp_migrate_set_parameters(bool has_compress_level,
     if (has_x_cpu_throttle_increment) {
         s->parameters.x_cpu_throttle_increment = x_cpu_throttle_increment;
     }
+    if (has_tls_creds) {
+        g_free(s->parameters.tls_creds);
+        s->parameters.tls_creds = g_strdup(tls_creds);
+    }
+    if (has_tls_hostname) {
+        g_free(s->parameters.tls_hostname);
+        s->parameters.tls_hostname = g_strdup(tls_hostname);
+    }
 }
 
 
diff --git a/qapi-schema.json b/qapi-schema.json
index 2fd6166..6aac524 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -617,11 +617,28 @@
 # @x-cpu-throttle-increment: throttle percentage increase each time
 #                            auto-converge detects that migration is not making
 #                            progress. The default value is 10. (Since 2.5)
+#
+# @tls-creds: ID of the 'tls-creds' object that provides credentials for
+#             establishing a TLS connection over the migration data channel.
+#             On the outgoing side of the migration, the credentials must
+#             be for a 'client' endpoint, while for the incoming side the
+#             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 2.6)
+#
+# @tls-hostname: hostname of the target host for the migration. This is
+#                required when using x509 based TLS credentials and the
+#                migration URI does not already include a hostname. For
+#                example if using fd: or exec: based migration, the
+#                hostname must be provided so that the server's x509
+#                certificate identity canbe validated. (Since 2.6)
+#
 # Since: 2.4
 ##
 { 'enum': 'MigrationParameter',
   'data': ['compress-level', 'compress-threads', 'decompress-threads',
-           'x-cpu-throttle-initial', 'x-cpu-throttle-increment'] }
+           'x-cpu-throttle-initial', 'x-cpu-throttle-increment',
+           'tls-creds', 'tls-hostname'] }
 
 #
 # @migrate-set-parameters
@@ -641,6 +658,22 @@
 # @x-cpu-throttle-increment: throttle percentage increase each time
 #                            auto-converge detects that migration is not making
 #                            progress. The default value is 10. (Since 2.5)
+#
+# @tls-creds: ID of the 'tls-creds' object that provides credentials for
+#             establishing a TLS connection over the migration data channel.
+#             On the outgoing side of the migration, the credentials must
+#             be for a 'client' endpoint, while for the incoming side the
+#             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 2.6)
+#
+# @tls-hostname: hostname of the target host for the migration. This is
+#                required when using x509 based TLS credentials and the
+#                migration URI does not already include a hostname. For
+#                example if using fd: or exec: based migration, the
+#                hostname must be provided so that the server's x509
+#                certificate identity canbe validated. (Since 2.6)
+#
 # Since: 2.4
 ##
 { 'command': 'migrate-set-parameters',
@@ -648,7 +681,9 @@
             '*compress-threads': 'int',
             '*decompress-threads': 'int',
             '*x-cpu-throttle-initial': 'int',
-            '*x-cpu-throttle-increment': 'int'} }
+            '*x-cpu-throttle-increment': 'int',
+            '*tls-creds': 'str',
+            '*tls-hostname': 'str'} }
 
 #
 # @MigrationParameters
@@ -667,6 +702,21 @@
 #                            auto-converge detects that migration is not making
 #                            progress. The default value is 10. (Since 2.5)
 #
+# @tls-creds: ID of the 'tls-creds' object that provides credentials for
+#             establishing a TLS connection over the migration data channel.
+#             On the outgoing side of the migration, the credentials must
+#             be for a 'client' endpoint, while for the incoming side the
+#             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 2.6)
+#
+# @tls-hostname: hostname of the target host for the migration. This is
+#                required when using x509 based TLS credentials and the
+#                migration URI does not already include a hostname. For
+#                example if using fd: or exec: based migration, the
+#                hostname must be provided so that the server's x509
+#                certificate identity canbe validated. (Since 2.6)
+#
 # Since: 2.4
 ##
 { 'struct': 'MigrationParameters',
@@ -674,7 +724,9 @@
             'compress-threads': 'int',
             'decompress-threads': 'int',
             'x-cpu-throttle-initial': 'int',
-            'x-cpu-throttle-increment': 'int'} }
+            'x-cpu-throttle-increment': 'int',
+            'tls-creds': 'str',
+            'tls-hostname': 'str'} }
 ##
 # @query-migrate-parameters
 #
-- 
2.5.0