modem: Allow to set current channel list

This adds support for setting the channels to override the boot up modem
defaults:

```
  busctl --system call org.freedesktop.ModemManager1 /org/freedesktop/ModemManager1/Modem/0 org.freedesktop.ModemManager1.Modem.CellBroadcast SetChannels 'a(uu)' 1 0 9999
  busctl --system get-property org.freedesktop.ModemManager1 /org/freedesktop/ModemManager1/Modem/0 org.freedesktop.ModemManager1.Modem.CellBroadcast Channels
  a(uu) 1 0 9999
```

Closes: https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/934

Signed-off-by: Guido Günther <agx@sigxcpu.org>

introspection/org.freedesktop.ModemManager1.Modem.CellBroadcast.xml

@@ -87,5 +87,27 @@
     -->
     <property name="CellBroadcasts" type="ao" access="read" />
 
+    <!--
+        SetChannels:
+        @channels: The list of channels
+
+        Set the list of channels to receive Cell Broadcasts for.
+
+        Since: 1.24
+    -->
+    <method name="SetChannels">
+      <arg name="channels" type="a(uu)" direction="in" />
+    </method>
+
+    <!--
+        Channels:
+
+        The list of channels that cell broadcast messages are
+        received for.
+
+        Since: 1.24
+    -->
+    <property name="Channels" type="a(uu)" access="read" />
+
   </interface>
 </node>

src/mm-broadband-modem.c

@@ -10603,6 +10603,66 @@ modem_cell_broadcast_create_cbm (MMIfaceModemCellBroadcast *self)
     return mm_base_cbm_new (MM_BASE_MODEM (self));
 }
 
+/***********************************************************************************/
+/* Get channels  (CellBroadcast interface) */
+
+static gboolean
+modem_cell_broadcast_set_channels_finish (MMIfaceModemCellBroadcast *self,
+                                          GAsyncResult *res,
+                                          GError **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void
+modem_cell_broadcast_set_channels_ready (MMBaseModem *self,
+                                         GAsyncResult *res,
+                                         GTask *task)
+{
+    GError *error = NULL;
+
+    if (!mm_base_modem_at_command_finish (self, res, &error))
+        g_task_return_error (task, error);
+    else
+        g_task_return_boolean (task, TRUE);
+    g_object_unref (task);
+}
+
+static void
+modem_cell_broadcast_set_channels (MMIfaceModemCellBroadcast *self,
+                                   GArray *channels,
+                                   GAsyncReadyCallback callback,
+                                   gpointer user_data)
+{
+    GTask *task;
+    g_autoptr (GString) cmd = g_string_new ("+CSCB=0,\"");
+    guint i;
+
+    task = g_task_new (self, NULL, callback, user_data);
+
+    for (i = 0; i < channels->len; i++) {
+        MMCellBroadcastChannels ch = g_array_index (channels, MMCellBroadcastChannels, i);
+
+        if (i > 0)
+            g_string_append_c (cmd, ',');
+
+        if (ch.start == ch.end)
+            g_string_append_printf (cmd, "%u", ch.start);
+        else
+            g_string_append_printf (cmd, "%u-%u", ch.start, ch.end);
+    }
+    g_string_append (cmd, "\",\"\"");
+
+    mm_obj_dbg (self, "Setting channels...");
+    mm_base_modem_at_command (
+        MM_BASE_MODEM (self),
+        cmd->str,
+        3,
+        FALSE,
+        (GAsyncReadyCallback)modem_cell_broadcast_set_channels_ready,
+        task);
+}
+
 /*********************************************************/
 /* Check CellBroadcast support (CellBroadcast interface) */
 
@@ -14344,6 +14404,8 @@ iface_modem_cell_broadcast_init (MMIfaceModemCellBroadcastInterface *iface)
     iface->setup_unsolicited_events_finish = modem_cell_broadcast_setup_cleanup_unsolicited_events_finish;
     iface->cleanup_unsolicited_events = modem_cell_broadcast_cleanup_unsolicited_events;
     iface->cleanup_unsolicited_events_finish = modem_cell_broadcast_setup_cleanup_unsolicited_events_finish;
+    iface->set_channels = modem_cell_broadcast_set_channels;
+    iface->set_channels_finish = modem_cell_broadcast_set_channels_finish;
     iface->create_cbm = modem_cell_broadcast_create_cbm;
 }
 

src/mm-iface-modem-cell-broadcast.c

@@ -42,6 +42,102 @@ mm_iface_modem_cell_broadcast_bind_simple_status (MMIfaceModemCellBroadcast *sel
 
 /*****************************************************************************/
 
+
+typedef struct {
+    MmGdbusModemCellBroadcast *skeleton;
+    GDBusMethodInvocation     *invocation;
+    MMIfaceModemCellBroadcast *self;
+    GArray                    *channels;
+} HandleSetChannelsCellBroadcastContext;
+
+static void
+handle_set_channels_context_free (HandleSetChannelsCellBroadcastContext *ctx)
+{
+    g_object_unref (ctx->skeleton);
+    g_object_unref (ctx->invocation);
+    g_object_unref (ctx->self);
+    g_array_unref (ctx->channels);
+    g_slice_free (HandleSetChannelsCellBroadcastContext, ctx);
+}
+
+static void
+set_channels_ready (MMIfaceModemCellBroadcast             *self,
+                    GAsyncResult                          *res,
+                    HandleSetChannelsCellBroadcastContext *ctx)
+{
+    GError *error = NULL;
+
+    if (!MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->set_channels_finish (self, res, &error))
+        mm_dbus_method_invocation_take_error (ctx->invocation, error);
+    else {
+        mm_gdbus_modem_cell_broadcast_set_channels (ctx->skeleton,
+                                                    mm_common_cell_broadcast_channels_garray_to_variant (ctx->channels));
+        mm_gdbus_modem_cell_broadcast_complete_set_channels (ctx->skeleton, ctx->invocation);
+    }
+
+    handle_set_channels_context_free (ctx);
+}
+
+static void
+handle_set_channels_auth_ready (MMBaseModem                           *self,
+                                GAsyncResult                          *res,
+                                HandleSetChannelsCellBroadcastContext *ctx)
+{
+    GError *error = NULL;
+
+    if (!mm_base_modem_authorize_finish (self, res, &error)) {
+        mm_dbus_method_invocation_take_error (ctx->invocation, error);
+        handle_set_channels_context_free (ctx);
+        return;
+    }
+
+    /* Validate channels (either number or range) */
+    if (!mm_validate_cbs_channels (ctx->channels, &error)) {
+        mm_dbus_method_invocation_return_gerror (ctx->invocation, error);
+        handle_set_channels_context_free (ctx);
+        return;
+    }
+
+    /* Check if plugin implements it */
+    if (!MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->set_channels ||
+        !MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->set_channels_finish) {
+        mm_dbus_method_invocation_return_error_literal (ctx->invocation, MM_CORE_ERROR, MM_CORE_ERROR_UNSUPPORTED,
+                                                        "Cannot set channels: not implemented");
+        handle_set_channels_context_free (ctx);
+        return;
+    }
+
+    /* Request to change channels */
+    mm_obj_info (self, "processing user request to set channels...");
+    MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->set_channels (ctx->self,
+                                                                  ctx->channels,
+                                                                  (GAsyncReadyCallback)set_channels_ready,
+                                                                  ctx);
+}
+
+static gboolean
+handle_set_channels (MmGdbusModemCellBroadcast *skeleton,
+                     GDBusMethodInvocation     *invocation,
+                     GVariant                  *channels,
+                     MMIfaceModemCellBroadcast *self)
+{
+    HandleSetChannelsCellBroadcastContext *ctx;
+
+    ctx = g_slice_new0 (HandleSetChannelsCellBroadcastContext);
+    ctx->skeleton = g_object_ref (skeleton);
+    ctx->invocation = g_object_ref (invocation);
+    ctx->self = g_object_ref (self);
+    ctx->channels = mm_common_cell_broadcast_channels_variant_to_garray (channels);
+    mm_base_modem_authorize (MM_BASE_MODEM (self),
+                             invocation,
+                             MM_AUTHORIZATION_DEVICE_CONTROL,
+                             (GAsyncReadyCallback)handle_set_channels_auth_ready,
+                             ctx);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
 typedef struct {
     MmGdbusModemCellBroadcast *skeleton;
     GDBusMethodInvocation *invocation;
@@ -315,6 +411,12 @@ interface_initialization_step (GTask *task)
 
     case INITIALIZATION_STEP_LAST:
         /* We are done without errors! */
+
+        /* Handle method invocations */
+        g_signal_connect (ctx->skeleton,
+                          "handle-set-channels",
+                          G_CALLBACK (handle_set_channels),
+                          self);
         g_signal_connect (ctx->skeleton,
                           "handle-delete",
                           G_CALLBACK (handle_delete),

src/mm-iface-modem-cell-broadcast.h

@@ -76,6 +76,15 @@ struct _MMIfaceModemCellBroadcastInterface {
 
     /* Create Cbm objects */
     MMBaseCbm * (* create_cbm) (MMIfaceModemCellBroadcast *self);
+
+    /* Set channel list */
+    void (* set_channels) (MMIfaceModemCellBroadcast *self,
+                           GArray *channels,
+                           GAsyncReadyCallback callback,
+                           gpointer user_data);
+    gboolean (* set_channels_finish) (MMIfaceModemCellBroadcast *self,
+                                      GAsyncResult *res,
+                                      GError **error);
 };
 
 /* Initialize CellBroadcast interface (async) */