api,simple: new 'multiplex' setting in bearer properties

Both the Simple.Connect() and Modem.CreateBearer() are updated to
allow a new 'multiplex' setting in the properties provided by the user
in both of these methods.

The new setting expects a MMBearerMultiplexSupport enum indicating
what kind of multiplex needs the user has:
 * none: if multiplex must not be used.
 * requested: if multiplex should be used if available.
 * required: if multiplex must be used.

The underlying implementations will take care of accepting or
rejecting the setting depending on the system and modem capabilities.

14 files changed, 203 insertions, 26 deletions

diff --git a/docs/reference/api/ModemManager-sections.txt b/docs/reference/api/ModemManager-sections.txt
index 478f4793..e0dc29f3 100644
--- a/docs/reference/api/ModemManager-sections.txt
+++ b/docs/reference/api/ModemManager-sections.txt
@@ -14,6 +14,7 @@ MMBearerType
 MMBearerIpFamily
 MMBearerIpMethod
 MMBearerAllowedAuth
+MMBearerMultiplexSupport
 MMCallDirection
 MMCallState
 MMCallStateReason
diff --git a/docs/reference/libmm-glib/libmm-glib-sections.txt b/docs/reference/libmm-glib/libmm-glib-sections.txt
index a077be65..92d25bc8 100644
--- a/docs/reference/libmm-glib/libmm-glib-sections.txt
+++ b/docs/reference/libmm-glib/libmm-glib-sections.txt
@@ -872,6 +872,8 @@ mm_simple_connect_properties_get_allow_roaming
 mm_simple_connect_properties_set_allow_roaming
 mm_simple_connect_properties_get_rm_protocol
 mm_simple_connect_properties_set_rm_protocol
+mm_simple_connect_properties_get_multiplex
+mm_simple_connect_properties_set_multiplex
 mm_simple_connect_properties_get_number
 mm_simple_connect_properties_set_number
 <SUBSECTION Private>
@@ -1189,10 +1191,12 @@ mm_bearer_properties_get_ip_type
 mm_bearer_properties_set_ip_type
 mm_bearer_properties_get_allow_roaming
 mm_bearer_properties_set_allow_roaming
-mm_bearer_properties_get_number
-mm_bearer_properties_set_number
 mm_bearer_properties_get_rm_protocol
 mm_bearer_properties_set_rm_protocol
+mm_bearer_properties_get_multiplex
+mm_bearer_properties_set_multiplex
+mm_bearer_properties_get_number
+mm_bearer_properties_set_number
 <SUBSECTION Private>
 mm_bearer_properties_new_from_dictionary
 mm_bearer_properties_new_from_string
@@ -1527,6 +1531,7 @@ mm_bearer_type_get_string
 mm_bearer_ip_method_get_string
 mm_bearer_ip_family_get_string
 mm_bearer_allowed_auth_build_string_from_mask
+mm_bearer_multiplex_support_get_string
 mm_modem_capability_build_string_from_mask
 mm_modem_state_get_string
 mm_modem_state_failed_reason_get_string
@@ -1589,6 +1594,7 @@ mm_bearer_type_build_string_from_mask
 mm_bearer_ip_family_build_string_from_mask
 mm_bearer_ip_method_build_string_from_mask
 mm_bearer_allowed_auth_get_string
+mm_bearer_multiplex_support_build_string_from_mask
 mm_modem_cdma_registration_state_build_string_from_mask
 mm_modem_cdma_activation_state_build_string_from_mask
 mm_modem_cdma_rm_protocol_build_string_from_mask
@@ -1613,6 +1619,7 @@ MM_TYPE_BEARER_TYPE
 MM_TYPE_BEARER_IP_FAMILY
 MM_TYPE_BEARER_IP_METHOD
 MM_TYPE_BEARER_ALLOWED_AUTH
+MM_TYPE_BEARER_MULTIPLEX_SUPPORT
 MM_TYPE_FIRMWARE_IMAGE_TYPE
 MM_TYPE_MODEM_3GPP_FACILITY
 MM_TYPE_MODEM_3GPP_NETWORK_AVAILABILITY
@@ -1655,6 +1662,7 @@ mm_bearer_type_get_type
 mm_bearer_ip_family_get_type
 mm_bearer_ip_method_get_type
 mm_bearer_allowed_auth_get_type
+mm_bearer_multiplex_support_get_type
 mm_firmware_image_type_get_type
 mm_modem_3gpp_facility_get_type
 mm_modem_3gpp_network_availability_get_type
diff --git a/include/ModemManager-enums.h b/include/ModemManager-enums.h
index 7f1be95a..0c9f2cb9 100644
--- a/include/ModemManager-enums.h
+++ b/include/ModemManager-enums.h
@@ -1526,4 +1526,22 @@ typedef enum { /*< underscore_name=mm_modem_firmware_update_method >*/
     MM_MODEM_FIRMWARE_UPDATE_METHOD_QMI_PDC  = 1 << 1,
 } MMModemFirmwareUpdateMethod;
 
+/**
+ * MMBearerMultiplexSupport:
+ * @MM_BEARER_MULTIPLEX_SUPPORT_UNKNOWN: Unknown.
+ * @MM_BEARER_MULTIPLEX_SUPPORT_NONE: No multiplex support should be used.
+ * @MM_BEARER_MULTIPLEX_SUPPORT_REQUESTED: If available, multiplex support should be used.
+ * @MM_BEARER_MULTIPLEX_SUPPORT_REQUIRED: Multiplex support must be used or otherwise the connection attempt will fail.
+ *
+ * Multiplex support requested by the user.
+ *
+ * Since: 1.18
+ */
+typedef enum { /*< underscore_name=mm_bearer_multiplex_support >*/
+    MM_BEARER_MULTIPLEX_SUPPORT_UNKNOWN   = 0,
+    MM_BEARER_MULTIPLEX_SUPPORT_NONE      = 1,
+    MM_BEARER_MULTIPLEX_SUPPORT_REQUESTED = 2,
+    MM_BEARER_MULTIPLEX_SUPPORT_REQUIRED  = 3,
+} MMBearerMultiplexSupport;
+
 #endif /*  _MODEMMANAGER_ENUMS_H_ */
diff --git a/introspection/org.freedesktop.ModemManager1.Modem.Simple.xml b/introspection/org.freedesktop.ModemManager1.Modem.Simple.xml
index 082e63d8..e40c6b0c 100644
--- a/introspection/org.freedesktop.ModemManager1.Modem.Simple.xml
+++ b/introspection/org.freedesktop.ModemManager1.Modem.Simple.xml
@@ -109,6 +109,13 @@
               value (signature <literal>"u"</literal>).
             </listitem>
           </varlistentry>
+          <varlistentry><term><literal>"multiplex"</literal></term>
+            <listitem>
+              Multiplex support requested by the user, given as a
+              <link linkend="MMBearerMultiplexSupport">MMBearerMultiplexSupport</link>
+              value (signature <literal>"u"</literal>). Since 1.18.
+            </listitem>
+          </varlistentry>
         </variablelist>
     -->
     <method name="Connect">
diff --git a/introspection/org.freedesktop.ModemManager1.Modem.xml b/introspection/org.freedesktop.ModemManager1.Modem.xml
index 529b26bd..25527394 100644
--- a/introspection/org.freedesktop.ModemManager1.Modem.xml
+++ b/introspection/org.freedesktop.ModemManager1.Modem.xml
@@ -81,6 +81,8 @@
           <listitem><para>Protocol of the Rm interface, given as a <link linkend="MMModemCdmaRmProtocol">MMModemCdmaRmProtocol</link> value (signature <literal>"u"</literal>). Optional in CDMA.</para></listitem></varlistentry>
         <varlistentry><term><literal>"number"</literal></term>
           <listitem><para>Number to dial for the data connection, given as a string value (signature <literal>"s"</literal>). Deprecated since version 1.10.0.</para></listitem></varlistentry>
+        <varlistentry><term><literal>"multiplex"</literal></term>
+          <listitem><para>Multiplex support requested by the user, given as a <link linkend="MMBearerMultiplexSupport">MMBearerMultiplexSupport</link> value (signature <literal>"u"</literal>). Since 1.18.</para></listitem></varlistentry>
         </variablelist>
 
         Some properties are only applicable to a bearer of certain access
diff --git a/libmm-glib/mm-bearer-properties.c b/libmm-glib/mm-bearer-properties.c
index 4305cec7..91827413 100644
--- a/libmm-glib/mm-bearer-properties.c
+++ b/libmm-glib/mm-bearer-properties.c
@@ -40,6 +40,7 @@ G_DEFINE_TYPE (MMBearerProperties, mm_bearer_properties, G_TYPE_OBJECT);
 #define PROPERTY_IP_TYPE         "ip-type"
 #define PROPERTY_ALLOW_ROAMING   "allow-roaming"
 #define PROPERTY_RM_PROTOCOL     "rm-protocol"
+#define PROPERTY_MULTIPLEX       "multiplex"
 
 /* no longer used properties */
 #define DEPRECATED_PROPERTY_NUMBER "number"
@@ -60,6 +61,8 @@ struct _MMBearerPropertiesPrivate {
     gboolean allow_roaming;
     /* Protocol of the Rm interface */
     MMModemCdmaRmProtocol rm_protocol;
+    /* Multiplex support */
+    MMBearerMultiplexSupport multiplex;
 };
 
 /*****************************************************************************/
@@ -390,6 +393,44 @@ mm_bearer_properties_get_rm_protocol (MMBearerProperties *self)
 /*****************************************************************************/
 
 /**
+ * mm_bearer_properties_set_multiplex:
+ * @self: a #MMBearerProperties.
+ * @multiplex: a #MMBearerMultiplexSupport.
+ *
+ * Gets the type of multiplex support requested by the user.
+ *
+ * Since: 1.18
+ */
+void
+mm_bearer_properties_set_multiplex (MMBearerProperties       *self,
+                                    MMBearerMultiplexSupport  multiplex)
+{
+    g_return_if_fail (MM_IS_BEARER_PROPERTIES (self));
+
+    self->priv->multiplex = multiplex;
+}
+
+/**
+ * mm_bearer_properties_get_multiplex:
+ * @self: a #MMBearerProperties.
+ *
+ * Gets the type of multiplex support requested by the user.
+ *
+ * Returns: a #MMBearerMultiplexSupport.
+ *
+ * Since: 1.18
+ */
+MMBearerMultiplexSupport
+mm_bearer_properties_get_multiplex (MMBearerProperties *self)
+{
+    g_return_val_if_fail (MM_IS_BEARER_PROPERTIES (self), MM_BEARER_MULTIPLEX_SUPPORT_UNKNOWN);
+
+    return self->priv->multiplex;
+}
+
+/*****************************************************************************/
+
+/**
  * mm_bearer_properties_get_dictionary: (skip)
  */
 GVariant *
@@ -447,6 +488,12 @@ mm_bearer_properties_get_dictionary (MMBearerProperties *self)
                                PROPERTY_RM_PROTOCOL,
                                g_variant_new_uint32 (self->priv->rm_protocol));
 
+    if (self->priv->multiplex)
+        g_variant_builder_add (&builder,
+                               "{sv}",
+                               PROPERTY_MULTIPLEX,
+                               g_variant_new_uint32 (self->priv->multiplex));
+
     return g_variant_ref_sink (g_variant_builder_end (&builder));
 }
 
@@ -509,6 +556,16 @@ mm_bearer_properties_consume_string (MMBearerProperties *self,
             return FALSE;
         }
         mm_bearer_properties_set_rm_protocol (self, protocol);
+    } else if (g_str_equal (key, PROPERTY_MULTIPLEX)) {
+        GError *inner_error = NULL;
+        MMBearerMultiplexSupport multiplex;
+
+        multiplex = mm_common_get_multiplex_support_from_string (value, &inner_error);
+        if (inner_error) {
+            g_propagate_error (error, inner_error);
+            return FALSE;
+        }
+        mm_bearer_properties_set_multiplex (self, multiplex);
     } else if (g_str_equal (key, DEPRECATED_PROPERTY_NUMBER)) {
         /* NO-OP */
     } else {
@@ -606,6 +663,10 @@ mm_bearer_properties_consume_variant (MMBearerProperties *properties,
         mm_bearer_properties_set_rm_protocol (
             properties,
             g_variant_get_uint32 (value));
+    else if (g_str_equal (key, PROPERTY_MULTIPLEX))
+        mm_bearer_properties_set_multiplex (
+            properties,
+            g_variant_get_uint32 (value));
     else if (g_str_equal (key, DEPRECATED_PROPERTY_NUMBER)) {
         /* NO-OP */
     } else {
@@ -651,10 +712,7 @@ mm_bearer_properties_new_from_dictionary (GVariant *dictionary,
     g_variant_iter_init (&iter, dictionary);
     while (!inner_error &&
            g_variant_iter_next (&iter, "{sv}", &key, &value)) {
-        mm_bearer_properties_consume_variant (properties,
-                                                     key,
-                                                     value,
-                                                     &inner_error);
+        mm_bearer_properties_consume_variant (properties, key, value, &inner_error);
         g_free (key);
         g_variant_unref (value);
     }
@@ -766,6 +824,8 @@ mm_bearer_properties_cmp (MMBearerProperties         *a,
     }
     if (a->priv->rm_protocol != b->priv->rm_protocol)
         return FALSE;
+    if (a->priv->multiplex != b->priv->multiplex)
+        return FALSE;
     return TRUE;
 }
 
@@ -799,6 +859,7 @@ mm_bearer_properties_init (MMBearerProperties *self)
     self->priv->rm_protocol = MM_MODEM_CDMA_RM_PROTOCOL_UNKNOWN;
     self->priv->allowed_auth = MM_BEARER_ALLOWED_AUTH_UNKNOWN;
     self->priv->ip_type = MM_BEARER_IP_FAMILY_NONE;
+    self->priv->multiplex = MM_BEARER_MULTIPLEX_SUPPORT_UNKNOWN;
 }
 
 static void
diff --git a/libmm-glib/mm-bearer-properties.h b/libmm-glib/mm-bearer-properties.h
index 340d9bf1..062d01c5 100644
--- a/libmm-glib/mm-bearer-properties.h
+++ b/libmm-glib/mm-bearer-properties.h
@@ -72,14 +72,17 @@ void mm_bearer_properties_set_allow_roaming (MMBearerProperties *self,
                                              gboolean allow_roaming);
 void mm_bearer_properties_set_rm_protocol   (MMBearerProperties *self,
                                              MMModemCdmaRmProtocol protocol);
-
-const gchar           *mm_bearer_properties_get_apn           (MMBearerProperties *self);
-MMBearerAllowedAuth    mm_bearer_properties_get_allowed_auth  (MMBearerProperties *self);
-const gchar           *mm_bearer_properties_get_user          (MMBearerProperties *self);
-const gchar           *mm_bearer_properties_get_password      (MMBearerProperties *self);
-MMBearerIpFamily       mm_bearer_properties_get_ip_type       (MMBearerProperties *self);
-gboolean               mm_bearer_properties_get_allow_roaming (MMBearerProperties *self);
-MMModemCdmaRmProtocol  mm_bearer_properties_get_rm_protocol   (MMBearerProperties *self);
+void mm_bearer_properties_set_multiplex     (MMBearerProperties       *self,
+                                             MMBearerMultiplexSupport  multiplex);
+
+const gchar              *mm_bearer_properties_get_apn           (MMBearerProperties *self);
+MMBearerAllowedAuth       mm_bearer_properties_get_allowed_auth  (MMBearerProperties *self);
+const gchar              *mm_bearer_properties_get_user          (MMBearerProperties *self);
+const gchar              *mm_bearer_properties_get_password      (MMBearerProperties *self);
+MMBearerIpFamily          mm_bearer_properties_get_ip_type       (MMBearerProperties *self);
+gboolean                  mm_bearer_properties_get_allow_roaming (MMBearerProperties *self);
+MMModemCdmaRmProtocol     mm_bearer_properties_get_rm_protocol   (MMBearerProperties *self);
+MMBearerMultiplexSupport  mm_bearer_properties_get_multiplex     (MMBearerProperties *self);
 
 #ifndef MM_DISABLE_DEPRECATED
 G_DEPRECATED
diff --git a/libmm-glib/mm-common-helpers.c b/libmm-glib/mm-common-helpers.c
index f2faf71c..a505421c 100644
--- a/libmm-glib/mm-common-helpers.c
+++ b/libmm-glib/mm-common-helpers.c
@@ -857,6 +857,16 @@ mm_common_get_eps_ue_mode_operation_from_string (const gchar  *str,
                               error);
 }
 
+MMBearerMultiplexSupport
+mm_common_get_multiplex_support_from_string (const gchar  *str,
+                                             GError      **error)
+{
+    return _enum_from_string (MM_TYPE_BEARER_MULTIPLEX_SUPPORT,
+                              str,
+                              MM_BEARER_MULTIPLEX_SUPPORT_UNKNOWN,
+                              error);
+}
+
 GArray *
 mm_common_oma_pending_network_initiated_sessions_variant_to_garray (GVariant *variant)
 {
diff --git a/libmm-glib/mm-common-helpers.h b/libmm-glib/mm-common-helpers.h
index 960a1f52..b8a75dfb 100644
--- a/libmm-glib/mm-common-helpers.h
+++ b/libmm-glib/mm-common-helpers.h
@@ -82,6 +82,9 @@ MMModem3gppEpsUeModeOperation mm_common_get_eps_ue_mode_operation_from_string (c
 MMModemAccessTechnology mm_common_get_access_technology_from_string (const gchar *str,
                                                                      GError **error);
 
+MMBearerMultiplexSupport mm_common_get_multiplex_support_from_string (const gchar  *str,
+                                                                      GError      **error);
+
 GArray          *mm_common_ports_variant_to_garray (GVariant *variant);
 MMModemPortInfo *mm_common_ports_variant_to_array  (GVariant *variant,
                                                  guint *n_ports);
diff --git a/libmm-glib/mm-simple-connect-properties.c b/libmm-glib/mm-simple-connect-properties.c
index fd256513..93006fc4 100644
--- a/libmm-glib/mm-simple-connect-properties.c
+++ b/libmm-glib/mm-simple-connect-properties.c
@@ -404,6 +404,44 @@ mm_simple_connect_properties_get_rm_protocol (MMSimpleConnectProperties *self)
 
 /*****************************************************************************/
 
+/**
+ * mm_simple_connect_properties_set_multiplex:
+ * @self: a #MMSimpleConnectProperties.
+ * @multiplex: a #MMBearerMultiplexSupport.
+ *
+ * Sets the multiplex support requested by the user.
+ *
+ * Since: 1.18
+ */
+void
+mm_simple_connect_properties_set_multiplex (MMSimpleConnectProperties *self,
+                                            MMBearerMultiplexSupport   multiplex)
+{
+    g_return_if_fail (MM_IS_SIMPLE_CONNECT_PROPERTIES (self));
+
+    mm_bearer_properties_set_multiplex (self->priv->bearer_properties, multiplex);
+}
+
+/**
+ * mm_simple_connect_properties_get_multiplex:
+ * @self: a #MMSimpleConnectProperties.
+ *
+ * Get the multiplex support requested by the user.
+ *
+ * Returns: a #MMBearerMultiplexSupport.
+ *
+ * Since: 1.18
+ */
+MMBearerMultiplexSupport
+mm_simple_connect_properties_get_multiplex (MMSimpleConnectProperties *self)
+{
+    g_return_val_if_fail (MM_IS_SIMPLE_CONNECT_PROPERTIES (self), MM_BEARER_MULTIPLEX_SUPPORT_UNKNOWN);
+
+    return mm_bearer_properties_get_multiplex (self->priv->bearer_properties);
+}
+
+/*****************************************************************************/
+
 #ifndef MM_DISABLE_DEPRECATED
 
 /**
diff --git a/libmm-glib/mm-simple-connect-properties.h b/libmm-glib/mm-simple-connect-properties.h
index d56f64f2..207ebaae 100644
--- a/libmm-glib/mm-simple-connect-properties.h
+++ b/libmm-glib/mm-simple-connect-properties.h
@@ -78,16 +78,19 @@ void mm_simple_connect_properties_set_allow_roaming (MMSimpleConnectProperties *
                                                      gboolean allow_roaming);
 void mm_simple_connect_properties_set_rm_protocol   (MMSimpleConnectProperties *self,
                                                      MMModemCdmaRmProtocol protocol);
-
-const gchar           *mm_simple_connect_properties_get_pin           (MMSimpleConnectProperties *self);
-const gchar           *mm_simple_connect_properties_get_operator_id   (MMSimpleConnectProperties *self);
-const gchar           *mm_simple_connect_properties_get_apn           (MMSimpleConnectProperties *self);
-MMBearerAllowedAuth    mm_simple_connect_properties_get_allowed_auth  (MMSimpleConnectProperties *self);
-const gchar           *mm_simple_connect_properties_get_user          (MMSimpleConnectProperties *self);
-const gchar           *mm_simple_connect_properties_get_password      (MMSimpleConnectProperties *self);
-MMBearerIpFamily       mm_simple_connect_properties_get_ip_type       (MMSimpleConnectProperties *self);
-gboolean               mm_simple_connect_properties_get_allow_roaming (MMSimpleConnectProperties *self);
-MMModemCdmaRmProtocol  mm_simple_connect_properties_get_rm_protocol   (MMSimpleConnectProperties *self);
+void mm_simple_connect_properties_set_multiplex     (MMSimpleConnectProperties *self,
+                                                     MMBearerMultiplexSupport multiplex);
+
+const gchar              *mm_simple_connect_properties_get_pin           (MMSimpleConnectProperties *self);
+const gchar              *mm_simple_connect_properties_get_operator_id   (MMSimpleConnectProperties *self);
+const gchar              *mm_simple_connect_properties_get_apn           (MMSimpleConnectProperties *self);
+MMBearerAllowedAuth       mm_simple_connect_properties_get_allowed_auth  (MMSimpleConnectProperties *self);
+const gchar              *mm_simple_connect_properties_get_user          (MMSimpleConnectProperties *self);
+const gchar              *mm_simple_connect_properties_get_password      (MMSimpleConnectProperties *self);
+MMBearerIpFamily          mm_simple_connect_properties_get_ip_type       (MMSimpleConnectProperties *self);
+gboolean                  mm_simple_connect_properties_get_allow_roaming (MMSimpleConnectProperties *self);
+MMModemCdmaRmProtocol     mm_simple_connect_properties_get_rm_protocol   (MMSimpleConnectProperties *self);
+MMBearerMultiplexSupport  mm_simple_connect_properties_get_multiplex     (MMSimpleConnectProperties *self);
 
 #ifndef MM_DISABLE_DEPRECATED
 G_DEPRECATED
diff --git a/plugins/iridium/mm-bearer-iridium.c b/plugins/iridium/mm-bearer-iridium.c
index 12b60419..6210eca3 100644
--- a/plugins/iridium/mm-bearer-iridium.c
+++ b/plugins/iridium/mm-bearer-iridium.c
@@ -183,6 +183,15 @@ connect (MMBaseBearer *self,
     GTask *task;
     MMBaseModem *modem  = NULL;
 
+    task = g_task_new (self, cancellable, callback, user_data);
+
+    if (mm_bearer_properties_get_multiplex (mm_base_bearer_peek_config (self)) == MM_BEARER_MULTIPLEX_SUPPORT_REQUIRED) {
+        g_task_return_new_error (task, MM_CORE_ERROR, MM_CORE_ERROR_UNSUPPORTED,
+                                 "Multiplex support not available");
+        g_object_unref (task);
+        return;
+    }
+
     g_object_get (self,
                   MM_BASE_BEARER_MODEM, &modem,
                   NULL);
@@ -194,8 +203,6 @@ connect (MMBaseBearer *self,
     /* In this context, we only keep the stuff we'll need later */
     ctx = g_new0 (ConnectContext, 1);
     ctx->primary = mm_base_modem_get_port_primary (modem);
-
-    task = g_task_new (self, cancellable, callback, user_data);
     g_task_set_task_data (task, ctx, (GDestroyNotify) connect_context_free);
 
     /* Bearer service type set to 9600bps (V.110), which behaves better than the
diff --git a/src/mm-bearer-mbim.c b/src/mm-bearer-mbim.c
index b808f547..c5ca427d 100644
--- a/src/mm-bearer-mbim.c
+++ b/src/mm-bearer-mbim.c
@@ -1125,6 +1125,14 @@ _connect (MMBaseBearer *self,
     if (!peek_ports (self, &device, &data, callback, user_data))
         return;
 
+    if (mm_bearer_properties_get_multiplex (mm_base_bearer_peek_config (self)) == MM_BEARER_MULTIPLEX_SUPPORT_REQUIRED) {
+        g_task_report_new_error (
+            self, callback, user_data, _connect,
+            MM_CORE_ERROR, MM_CORE_ERROR_UNSUPPORTED,
+            "Multiplex support not available");
+        return;
+    }
+
     g_object_get (self,
                   MM_BASE_BEARER_MODEM, &modem,
                   NULL);
diff --git a/src/mm-bearer-qmi.c b/src/mm-bearer-qmi.c
index 670fb804..a31ae860 100644
--- a/src/mm-bearer-qmi.c
+++ b/src/mm-bearer-qmi.c
@@ -1692,6 +1692,14 @@ _connect (MMBaseBearer *_self,
     GTask *task;
     GCancellable *operation_cancellable = NULL;
 
+    if (mm_bearer_properties_get_multiplex (mm_base_bearer_peek_config (_self)) == MM_BEARER_MULTIPLEX_SUPPORT_REQUIRED) {
+        g_task_report_new_error (
+            self, callback, user_data, _connect,
+            MM_CORE_ERROR, MM_CORE_ERROR_UNSUPPORTED,
+            "Multiplex support not available");
+        goto out;
+    }
+
     g_object_get (self,
                   MM_BASE_BEARER_MODEM, &modem,
                   NULL);