broadband-modem-mbim: limit the use of context types defined in MBIMEx

The Tethering context type UUID was defined by Microsoft in its
extensions as `5e4e0601-48dc-4e2b-acb8-08b4016bbaac` (along with
others like Admin, Xcap, App and EmergencyCalling), see
https://learn.microsoft.com/en-us/windows-hardware/drivers/network/mb-provisioned-context-operations.

These UUIDs are expected to be usable only if the modem supports
`MBIM_CID_MS_PROVISIONED_CONTEXT_V2` (CID=1) in the Basic Connect
Extensions service (3d01dcc5-fef5-4d05-0d3abef7058e9aaf).

If the modem doesn't support these, we should try to fallback to a
more generic APN type automatically, e.g. "Internet", which was
defined in MBIM 1.0 and should always be supported.

There should be no problem in a modem to have 2 separate PDN
connections with the same context type.

src/mm-bearer-mbim.c

@@ -907,9 +907,13 @@ load_settings_from_profile (MMBearerMbim    *self,
                             MMBearerApnType  default_apn_type,
                             GError         **error)
 {
-    MMBearerAllowedAuth  bearer_auth;
+    MMBearerAllowedAuth     bearer_auth;
-    MMBearerApnType      apn_type;
+    MMBearerApnType         apn_type;
-    GError              *inner_error = NULL;
+    GError                 *inner_error = NULL;
+    g_autoptr(MMBaseModem)  modem  = NULL;
+
+    g_object_get (self, MM_BASE_BEARER_MODEM,  &modem, NULL);
+    g_assert (modem);
 
     /* APN settings */
     ctx->apn = g_strdup (mm_3gpp_profile_get_apn (profile));
@@ -922,7 +926,11 @@ load_settings_from_profile (MMBearerMbim    *self,
         }
         apn_type = default_apn_type;
     }
-    ctx->context_type = mm_bearer_apn_type_to_mbim_context_type (apn_type, self, &inner_error);
+    ctx->context_type = mm_bearer_apn_type_to_mbim_context_type (
+                            apn_type,
+                            mm_broadband_modem_mbim_is_context_type_ext_supported (MM_BROADBAND_MODEM_MBIM (modem)),
+                            self,
+                            &inner_error);
     if (inner_error) {
         g_propagate_error (error, inner_error);
         return FALSE;

src/mm-broadband-modem-mbim.c

@@ -120,6 +120,7 @@ struct _MMBroadbandModemMbimPrivate {
     /* Supported features */
     gboolean is_profile_management_supported;
     gboolean is_profile_management_ext_supported;
+    gboolean is_context_type_ext_supported;
     gboolean is_pco_supported;
     gboolean is_lte_attach_info_supported;
     gboolean is_nr5g_registration_settings_supported;
@@ -389,6 +390,14 @@ mm_broadband_modem_mbim_peek_port_mbim_for_data (MMBroadbandModemMbim  *self,
     return MM_BROADBAND_MODEM_MBIM_GET_CLASS (self)->peek_port_mbim_for_data (self, data, error);
 }
 
+/*****************************************************************************/
+
+gboolean
+mm_broadband_modem_mbim_is_context_type_ext_supported (MMBroadbandModemMbim *self)
+{
+    return self->priv->is_context_type_ext_supported;
+}
+
 /*****************************************************************************/
 /* Current capabilities (Modem interface) */
 
@@ -3281,6 +3290,8 @@ query_device_services_ready (MbimDevice   *device,
                         mm_obj_dbg (self, "Base stations info is supported");
                         self->priv->is_base_stations_info_supported = TRUE;
                     } else if (device_services[i]->cids[j] == MBIM_CID_MS_BASIC_CONNECT_EXTENSIONS_PROVISIONED_CONTEXTS) {
+                        mm_obj_dbg (self, "Context types extension is supported");
+                        self->priv->is_context_type_ext_supported = TRUE;
                         if (mm_context_get_test_mbimex_profile_management ()) {
                             mm_obj_dbg (self, "Profile management extension is supported");
                             self->priv->is_profile_management_ext_supported = TRUE;
@@ -7223,7 +7234,10 @@ modem_3gpp_profile_manager_store_profile (MMIfaceModem3gppProfileManager *_self,
 
     ctx->apn_type = mm_3gpp_profile_get_apn_type (profile);
     apn_type_str = mm_bearer_apn_type_build_string_from_mask (ctx->apn_type);
-    context_type = mm_bearer_apn_type_to_mbim_context_type (ctx->apn_type, self, &error);
+    context_type = mm_bearer_apn_type_to_mbim_context_type (ctx->apn_type,
+                                                            self->priv->is_context_type_ext_supported,
+                                                            self,
+                                                            &error);
     if (error) {
         g_prefix_error (&error, "Failed to convert mbim context type from apn type: ");
         g_task_return_error (task, error);
@@ -7398,11 +7412,11 @@ modem_3gpp_profile_manager_delete_profile (MMIfaceModem3gppProfileManager *_self
         MbimContextType  context_type;
 
         g_assert (self->priv->is_profile_management_ext_supported);
+        g_assert (self->priv->is_context_type_ext_supported);
 
         apn_type = mm_3gpp_profile_get_apn_type (profile);
         g_assert (apn_type != MM_BEARER_APN_TYPE_NONE);
-
+        context_type = mm_bearer_apn_type_to_mbim_context_type (apn_type, TRUE, self, &error);
-        context_type = mm_bearer_apn_type_to_mbim_context_type (apn_type, self, &error);
         if (error)
             g_prefix_error (&error, "Failed to convert mbim context type from apn type: ");
         else {

src/mm-broadband-modem-mbim.h

@@ -71,4 +71,6 @@ void mm_broadband_modem_mbim_get_speeds (MMBroadbandModemMbim *self,
                                          guint64              *uplink_speed,
                                          guint64              *downlink_speed);
 
+gboolean mm_broadband_modem_mbim_is_context_type_ext_supported (MMBroadbandModemMbim *self);
+
 #endif /* MM_BROADBAND_MODEM_MBIM_H */

src/mm-modem-helpers-mbim.c

@@ -562,6 +562,7 @@ mm_bearer_apn_type_from_mbim_context_type (MbimContextType context_type)
 
 MbimContextType
 mm_bearer_apn_type_to_mbim_context_type (MMBearerApnType   apn_type,
+                                         gboolean          mbim_extensions_supported,
                                          gpointer          log_object,
                                          GError          **error)
 {
@@ -580,8 +581,6 @@ mm_bearer_apn_type_to_mbim_context_type (MMBearerApnType   apn_type,
         return MBIM_CONTEXT_TYPE_IMS;
     if (apn_type & MM_BEARER_APN_TYPE_MMS)
         return MBIM_CONTEXT_TYPE_MMS;
-    if (apn_type &MM_BEARER_APN_TYPE_MANAGEMENT)
-        return MBIM_CONTEXT_TYPE_ADMIN;
     if (apn_type & MM_BEARER_APN_TYPE_VOICE)
         return MBIM_CONTEXT_TYPE_VOICE;
     if (apn_type & MM_BEARER_APN_TYPE_PRIVATE)
@@ -592,14 +591,30 @@ mm_bearer_apn_type_to_mbim_context_type (MMBearerApnType   apn_type,
         return MBIM_CONTEXT_TYPE_VIDEO_SHARE;
     if (apn_type & MM_BEARER_APN_TYPE_LOCAL)
         return MBIM_CONTEXT_TYPE_LOCAL;
-    if (apn_type & MM_BEARER_APN_TYPE_APP)
+
-        return MBIM_CONTEXT_TYPE_APP;
+    if (mbim_extensions_supported) {
-    if (apn_type & MM_BEARER_APN_TYPE_XCAP)
+        if (apn_type & MM_BEARER_APN_TYPE_MANAGEMENT)
-        return MBIM_CONTEXT_TYPE_XCAP;
+            return MBIM_CONTEXT_TYPE_ADMIN;
-    if (apn_type & MM_BEARER_APN_TYPE_TETHERING)
+        if (apn_type & MM_BEARER_APN_TYPE_APP)
-        return MBIM_CONTEXT_TYPE_TETHERING;
+            return MBIM_CONTEXT_TYPE_APP;
-    if (apn_type & MM_BEARER_APN_TYPE_EMERGENCY)
+        if (apn_type & MM_BEARER_APN_TYPE_XCAP)
-        return MBIM_CONTEXT_TYPE_EMERGENCY_CALLING;
+            return MBIM_CONTEXT_TYPE_XCAP;
+        if (apn_type & MM_BEARER_APN_TYPE_TETHERING)
+            return MBIM_CONTEXT_TYPE_TETHERING;
+        if (apn_type & MM_BEARER_APN_TYPE_EMERGENCY)
+            return MBIM_CONTEXT_TYPE_EMERGENCY_CALLING;
+    } else {
+        if ((apn_type & MM_BEARER_APN_TYPE_MANAGEMENT) ||
+            (apn_type & MM_BEARER_APN_TYPE_APP)        ||
+            (apn_type & MM_BEARER_APN_TYPE_XCAP)       ||
+            (apn_type & MM_BEARER_APN_TYPE_TETHERING)  ||
+            (apn_type & MM_BEARER_APN_TYPE_EMERGENCY)) {
+            mm_obj_dbg (log_object,
+                        "MS extensions unsupported: "
+                        "fallback to using default (internet) APN type");
+            return MBIM_CONTEXT_TYPE_INTERNET;
+        }
+    }
 
     str = mm_bearer_apn_type_build_string_from_mask (apn_type);
     g_set_error (error,

src/mm-modem-helpers-mbim.h

@@ -66,6 +66,7 @@ MbimContextIpType   mm_bearer_ip_family_to_mbim_context_ip_type    (MMBearerIpFa
                                                                     GError              **error);
 MMBearerApnType     mm_bearer_apn_type_from_mbim_context_type      (MbimContextType       context_type);
 MbimContextType     mm_bearer_apn_type_to_mbim_context_type        (MMBearerApnType       apn_type,
+                                                                    gboolean              mbim_extensions_supported,
                                                                     gpointer              log_object,
                                                                     GError              **error);