cbm: Add CellBroadcast interface

This adds support for the Cell Broadcast interface allowing to
receive, list, read and delete Cell Broadcast messages via the
org.freedesktop.ModemManager1.Modem.CellBroadcast and
org.freedesktop.ModemManager1.Cbm interfaces.

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

8 files changed, 1918 insertions, 0 deletions

diff --git a/src/meson.build b/src/meson.build
index 01c5e12c..f88d905a 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -259,6 +259,7 @@ sources = files(
   'mm-auth-provider.c',
   'mm-base-bearer.c',
   'mm-base-call.c',
+  'mm-base-cbm.c',
   'mm-base-manager.c',
   'mm-base-modem-at.c',
   'mm-base-modem.c',
@@ -268,6 +269,7 @@ sources = files(
   'mm-broadband-bearer.c',
   'mm-broadband-modem.c',
   'mm-call-list.c',
+  'mm-cbm-list.c',
   'mm-context.c',
   'mm-device.c',
   'mm-dispatcher.c',
@@ -280,6 +282,7 @@ sources = files(
   'mm-iface-modem-3gpp-ussd.c',
   'mm-iface-modem.c',
   'mm-iface-modem-cdma.c',
+  'mm-iface-modem-cell-broadcast.c',
   'mm-iface-modem-firmware.c',
   'mm-iface-modem-location.c',
   'mm-iface-modem-messaging.c',
diff --git a/src/mm-auth-provider.h b/src/mm-auth-provider.h
index c33e42ce..6065c806 100644
--- a/src/mm-auth-provider.h
+++ b/src/mm-auth-provider.h
@@ -37,6 +37,7 @@
 #define MM_AUTHORIZATION_LOCATION        "org.freedesktop.ModemManager1.Location"
 #define MM_AUTHORIZATION_TIME            "org.freedesktop.ModemManager1.Time"
 #define MM_AUTHORIZATION_FIRMWARE        "org.freedesktop.ModemManager1.Firmware"
+#define MM_AUTHORIZATION_CELL_BROADCAST  "org.freedesktop.ModemManager1.CellBroadcast"
 
 typedef struct _MMAuthProvider        MMAuthProvider;
 typedef struct _MMAuthProviderClass   MMAuthProviderClass;
diff --git a/src/mm-base-cbm.c b/src/mm-base-cbm.c
new file mode 100644
index 00000000..d35141be
--- /dev/null
+++ b/src/mm-base-cbm.c
@@ -0,0 +1,571 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2024 Guido Günther <agx@sigxcpu.org>
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+
+#include <ModemManager.h>
+#define _LIBMM_INSIDE_MM
+#include <libmm-glib.h>
+
+#include "mm-base-cbm.h"
+#include "mm-broadband-modem.h"
+#include "mm-iface-modem.h"
+#include "mm-iface-modem-cell-broadcast.h"
+#include "mm-cbm-part.h"
+#include "mm-base-modem-at.h"
+#include "mm-base-modem.h"
+#include "mm-log-object.h"
+#include "mm-modem-helpers.h"
+#include "mm-error-helpers.h"
+
+static void log_object_iface_init (MMLogObjectInterface *iface);
+
+G_DEFINE_TYPE_EXTENDED (MMBaseCbm, mm_base_cbm, MM_GDBUS_TYPE_CBM_SKELETON, 0,
+                        G_IMPLEMENT_INTERFACE (MM_TYPE_LOG_OBJECT, log_object_iface_init))
+
+enum {
+    PROP_0,
+    PROP_PATH,
+    PROP_CONNECTION,
+    PROP_MODEM,
+    PROP_MAX_PARTS,
+    PROP_SERIAL,
+    PROP_LAST
+};
+
+static GParamSpec *properties[PROP_LAST];
+
+struct _MMBaseCbmPrivate {
+    /* The connection to the system bus */
+    GDBusConnection *connection;
+    guint            dbus_id;
+
+    /* The modem which owns this CBM */
+    MMBaseModem *modem;
+    /* The path where the CBM object is exported */
+    gchar *path;
+
+    /* List of CBM parts */
+    guint max_parts;
+    GList *parts;
+
+    /* channel and serial identify the CBM */
+    guint16 serial;
+
+    /* Set to true when all needed parts were received,
+     * parsed and assembled */
+    gboolean is_assembled;
+};
+
+void
+mm_base_cbm_export (MMBaseCbm *self)
+{
+    g_autofree gchar *path = NULL;
+
+    path = g_strdup_printf (MM_DBUS_CBM_PREFIX "/%d", self->priv->dbus_id);
+    g_object_set (self,
+                  MM_BASE_CBM_PATH, path,
+                  NULL);
+}
+
+void
+mm_base_cbm_unexport (MMBaseCbm *self)
+{
+    g_object_set (self,
+                  MM_BASE_CBM_PATH, NULL,
+                  NULL);
+}
+
+/*****************************************************************************/
+
+static void
+cbm_dbus_export (MMBaseCbm *self)
+{
+    g_autoptr (GError) error = NULL;
+
+    if (!g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (self),
+                                           self->priv->connection,
+                                           self->priv->path,
+                                           &error)) {
+        mm_obj_warn (self, "couldn't export CBM: %s", error->message);
+    }
+}
+
+static void
+cbm_dbus_unexport (MMBaseCbm *self)
+{
+    /* Only unexport if currently exported */
+    if (g_dbus_interface_skeleton_get_object_path (G_DBUS_INTERFACE_SKELETON (self)))
+        g_dbus_interface_skeleton_unexport (G_DBUS_INTERFACE_SKELETON (self));
+}
+
+/*****************************************************************************/
+
+const gchar *
+mm_base_cbm_get_path (MMBaseCbm *self)
+{
+    return self->priv->path;
+}
+
+gboolean
+mm_base_cbm_is_complete (MMBaseCbm *self)
+{
+    return (g_list_length (self->priv->parts) == self->priv->max_parts);
+}
+
+/*****************************************************************************/
+
+static guint
+cmp_cbm_part_has_num (MMCbmPart *part,
+                      gpointer user_data)
+{
+    return (GPOINTER_TO_UINT (user_data) - mm_cbm_part_get_part_num (part));
+}
+
+gboolean
+mm_base_cbm_has_part_num (MMBaseCbm *self,
+                          guint      part_num)
+{
+    return !!g_list_find_custom (self->priv->parts,
+                                 GUINT_TO_POINTER (part_num),
+                                 (GCompareFunc)cmp_cbm_part_has_num);
+}
+
+GList *
+mm_base_cbm_get_parts (MMBaseCbm *self)
+{
+    return self->priv->parts;
+}
+
+/*****************************************************************************/
+
+static void
+initialize_cbm (MMBaseCbm *self)
+{
+    MMCbmPart *part;
+    guint16 serial;
+
+    /* Some of the fields of the CBM object may be initialized as soon as we have
+     * one part already available, even if it's not exactly the first one */
+    g_assert (self->priv->parts);
+    part = (MMCbmPart *)(self->priv->parts->data);
+
+    serial = mm_cbm_part_get_serial (part);
+    g_object_set (self,
+                  MM_BASE_CBM_MAX_PARTS,  mm_cbm_part_get_num_parts (part),
+                  MM_BASE_CBM_SERIAL,     serial,
+                  "channel",              mm_cbm_part_get_channel (part),
+                  "update",               CBM_SERIAL_MESSAGE_CODE_UPDATE (serial),
+                  "message-code",         CBM_SERIAL_MESSAGE_CODE (serial),
+                  NULL);
+}
+
+static gboolean
+assemble_cbm (MMBaseCbm  *self,
+              GError    **error)
+{
+    GList      *l;
+    guint       part_num, idx;
+    g_autofree MMCbmPart **sorted_parts = NULL;
+    g_autoptr (GString) fulltext = NULL;
+
+    sorted_parts = g_new0 (MMCbmPart *, self->priv->max_parts);
+
+    /* Check if we have duplicate parts */
+    for (l = self->priv->parts; l; l = g_list_next (l)) {
+        part_num = mm_cbm_part_get_part_num ((MMCbmPart *)l->data);
+
+        /* part_num starts at 1, array starts at 0 */
+        idx = part_num - 1;
+        if (part_num < 1 || part_num > self->priv->max_parts) {
+            mm_obj_warn (self, "invalid part part nu (%u) found, ignoring", part_num);
+            continue;
+        }
+
+        if (sorted_parts[idx]) {
+            mm_obj_warn (self, "duplicate part index (%u) found, ignoring", part_num);
+            continue;
+        }
+
+        /* Add the part to the proper array position */
+        sorted_parts[idx] = (MMCbmPart *)l->data;
+    }
+
+    fulltext = g_string_new ("");
+
+    /* Assemble text and data from all parts. */
+    for (idx = 0; idx < self->priv->max_parts; idx++) {
+        const gchar *parttext;
+
+        if (!sorted_parts[idx]) {
+            g_set_error (error,
+                         MM_CORE_ERROR,
+                         MM_CORE_ERROR_FAILED,
+                         "Cannot assemble CBM, missing part at index (%u)",
+                         idx);
+            return FALSE;
+        }
+
+        parttext = mm_cbm_part_get_text (sorted_parts[idx]);
+        if (!parttext) {
+            g_set_error (error,
+                         MM_CORE_ERROR,
+                         MM_CORE_ERROR_FAILED,
+                         "Cannot assemble CBM, part at index (%u) has no text",
+                         idx);
+            return FALSE;
+        }
+
+        if (parttext)
+            g_string_append (fulltext, parttext);
+    }
+
+    /* If we got all parts, we also have the first one always */
+    g_assert (sorted_parts[0] != NULL);
+
+    /* If we got everything, assemble the text! */
+    g_object_set (self,
+                  "text", fulltext->str,
+                  NULL);
+
+    self->priv->is_assembled = TRUE;
+
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static guint
+cmp_cbm_part_num (MMCbmPart *a,
+                  MMCbmPart *b)
+{
+    return (mm_cbm_part_get_part_num (a) - mm_cbm_part_get_part_num (b));
+}
+
+gboolean
+mm_base_cbm_take_part (MMBaseCbm *self,
+                       MMCbmPart *part,
+                       GError **error)
+{
+    if (g_list_length (self->priv->parts) >= self->priv->max_parts) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_FAILED,
+                     "Already took %u parts, cannot take more",
+                     g_list_length (self->priv->parts));
+        return FALSE;
+    }
+
+    if (g_list_find_custom (self->priv->parts,
+                            part,
+                            (GCompareFunc)cmp_cbm_part_num)) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_FAILED,
+                     "Cannot take part, part %u already taken",
+                     mm_cbm_part_get_part_num (part));
+        return FALSE;
+    }
+
+    if (mm_cbm_part_get_part_num (part) > self->priv->max_parts) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_FAILED,
+                     "Cannot take part with number %u, maximum is %u",
+                     mm_cbm_part_get_part_num (part),
+                     self->priv->max_parts);
+        return FALSE;
+    }
+
+    /* Insert sorted by concat sequence */
+    self->priv->parts = g_list_insert_sorted (self->priv->parts,
+                                              part,
+                                              (GCompareFunc)cmp_cbm_part_num);
+
+    /* If this is the first part we take, initialize common CBM fields */
+    if (g_list_length (self->priv->parts) == 1)
+        initialize_cbm (self);
+
+    /* We only populate contents when the multipart CBM is complete */
+    if (mm_base_cbm_is_complete (self)) {
+        g_autoptr (GError) inner_error = NULL;
+
+        if (!assemble_cbm (self, &inner_error)) {
+            /* We DO NOT propagate the error. The part was properly taken
+             * so ownership passed to the MMBaseCbm object. */
+            mm_obj_warn (self, "couldn't assemble CBM: %s", inner_error->message);
+        } else {
+            /* Completed AND assembled
+             * Change state RECEIVING->RECEIVED, and signal completeness */
+            if (mm_gdbus_cbm_get_state (MM_GDBUS_CBM (self)) == MM_CBM_STATE_RECEIVING)
+                mm_gdbus_cbm_set_state (MM_GDBUS_CBM (self), MM_CBM_STATE_RECEIVED);
+        }
+    }
+
+    return TRUE;
+}
+
+MMBaseCbm *
+mm_base_cbm_new (MMBaseModem *modem)
+{
+    return MM_BASE_CBM (g_object_new (MM_TYPE_BASE_CBM,
+                                      MM_BASE_CBM_MODEM, modem,
+                                      NULL));
+}
+
+MMBaseCbm *
+mm_base_cbm_new_with_part (MMBaseModem *modem,
+                           MMCbmState state,
+                           guint max_parts,
+                           MMCbmPart *first_part,
+                           GError **error)
+{
+    MMBaseCbm *self;
+
+    g_assert (MM_IS_IFACE_MODEM_CELL_BROADCAST (modem));
+
+    if (state == MM_CBM_STATE_RECEIVED)
+        state = MM_CBM_STATE_RECEIVING;
+
+    /* Create a CBM object as defined by the interface */
+    self = mm_iface_modem_cell_broadcast_create_cbm (MM_IFACE_MODEM_CELL_BROADCAST (modem));
+    g_object_set (self,
+                  MM_BASE_CBM_MAX_PARTS,           max_parts,
+                  "state",                         state,
+                  NULL);
+
+    if (!mm_base_cbm_take_part (self, first_part, error))
+        g_clear_object (&self);
+
+    /* We do export uncomplete multipart messages, so clients can make use of it
+     * Only the STATE of the CBM object will be valid in the exported DBus
+     * interface intially.*/
+    if (self)
+        mm_base_cbm_export (self);
+
+    return self;
+}
+
+/*****************************************************************************/
+
+static gchar *
+log_object_build_id (MMLogObject *_self)
+{
+    MMBaseCbm *self;
+
+    self = MM_BASE_CBM (_self);
+    return g_strdup_printf ("cbm%u", self->priv->dbus_id);
+}
+
+/*****************************************************************************/
+
+static void
+set_property (GObject *object,
+              guint prop_id,
+              const GValue *value,
+              GParamSpec *pspec)
+{
+    MMBaseCbm *self = MM_BASE_CBM (object);
+
+    switch (prop_id) {
+    case PROP_PATH:
+        g_free (self->priv->path);
+        self->priv->path = g_value_dup_string (value);
+
+        /* Export when we get a DBus connection AND we have a path */
+        if (!self->priv->path)
+            cbm_dbus_unexport (self);
+        else if (self->priv->connection)
+            cbm_dbus_export (self);
+        break;
+    case PROP_CONNECTION:
+        g_clear_object (&self->priv->connection);
+        self->priv->connection = g_value_dup_object (value);
+
+        /* Export when we get a DBus connection AND we have a path */
+        if (!self->priv->connection)
+            cbm_dbus_unexport (self);
+        else if (self->priv->path)
+            cbm_dbus_export (self);
+        break;
+    case PROP_MODEM:
+        g_clear_object (&self->priv->modem);
+        self->priv->modem = g_value_dup_object (value);
+        if (self->priv->modem) {
+            /* Set owner ID */
+            mm_log_object_set_owner_id (MM_LOG_OBJECT (self), mm_log_object_get_id (MM_LOG_OBJECT (self->priv->modem)));
+            /* Bind the modem's connection (which is set when it is exported,
+             * and unset when unexported) to the CBM's connection */
+            g_object_bind_property (self->priv->modem, MM_BASE_MODEM_CONNECTION,
+                                    self, MM_BASE_CBM_CONNECTION,
+                                    G_BINDING_DEFAULT | G_BINDING_SYNC_CREATE);
+        }
+        break;
+    case PROP_MAX_PARTS:
+        self->priv->max_parts = g_value_get_uint (value);
+        break;
+    case PROP_SERIAL:
+        self->priv->serial = g_value_get_uint (value);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+get_property (GObject *object,
+              guint prop_id,
+              GValue *value,
+              GParamSpec *pspec)
+{
+    MMBaseCbm *self = MM_BASE_CBM (object);
+
+    switch (prop_id) {
+    case PROP_PATH:
+        g_value_set_string (value, self->priv->path);
+        break;
+    case PROP_CONNECTION:
+        g_value_set_object (value, self->priv->connection);
+        break;
+    case PROP_MODEM:
+        g_value_set_object (value, self->priv->modem);
+        break;
+    case PROP_MAX_PARTS:
+        g_value_set_uint (value, self->priv->max_parts);
+        break;
+    case PROP_SERIAL:
+        g_value_set_uint (value, self->priv->serial);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+mm_base_cbm_init (MMBaseCbm *self)
+{
+    static guint id = 0;
+
+    /* Initialize private data */
+    self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, MM_TYPE_BASE_CBM, MMBaseCbmPrivate);
+    self->priv->max_parts = 1;
+
+    /* Each CBM is given a unique id to build its own DBus path */
+    self->priv->dbus_id = id++;
+}
+
+static void
+finalize (GObject *object)
+{
+    MMBaseCbm *self = MM_BASE_CBM (object);
+
+    g_list_free_full (self->priv->parts, (GDestroyNotify)mm_cbm_part_free);
+    g_free (self->priv->path);
+
+    G_OBJECT_CLASS (mm_base_cbm_parent_class)->finalize (object);
+}
+
+static void
+dispose (GObject *object)
+{
+    MMBaseCbm *self = MM_BASE_CBM (object);
+
+    if (self->priv->connection) {
+        /* If we arrived here with a valid connection, make sure we unexport
+         * the object */
+        cbm_dbus_unexport (self);
+        g_clear_object (&self->priv->connection);
+    }
+
+    g_clear_object (&self->priv->modem);
+
+    G_OBJECT_CLASS (mm_base_cbm_parent_class)->dispose (object);
+}
+
+static void
+log_object_iface_init (MMLogObjectInterface *iface)
+{
+    iface->build_id = log_object_build_id;
+}
+
+static void
+mm_base_cbm_class_init (MMBaseCbmClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+    g_type_class_add_private (object_class, sizeof (MMBaseCbmPrivate));
+
+    /* Virtual methods */
+    object_class->get_property = get_property;
+    object_class->set_property = set_property;
+    object_class->finalize = finalize;
+    object_class->dispose = dispose;
+
+    properties[PROP_CONNECTION] =
+        g_param_spec_object (MM_BASE_CBM_CONNECTION,
+                             "Connection",
+                             "GDBus connection to the system bus.",
+                             G_TYPE_DBUS_CONNECTION,
+                             G_PARAM_READWRITE);
+
+    properties[PROP_PATH] =
+        g_param_spec_string (MM_BASE_CBM_PATH,
+                             "Path",
+                             "DBus path of the CBM",
+                             NULL,
+                             G_PARAM_READWRITE);
+
+    properties[PROP_MODEM] =
+        g_param_spec_object (MM_BASE_CBM_MODEM,
+                             "Modem",
+                             "The Modem which owns this CBM",
+                             MM_TYPE_BASE_MODEM,
+                             G_PARAM_READWRITE);
+
+    properties[PROP_MAX_PARTS] =
+        g_param_spec_uint (MM_BASE_CBM_MAX_PARTS,
+                           "Max parts",
+                           "Maximum number of parts composing this CBM",
+                           1, 255, 1,
+                           G_PARAM_READWRITE);
+
+    properties[PROP_SERIAL] =
+        g_param_spec_uint (MM_BASE_CBM_SERIAL,
+                           "Serial",
+                           "The serial of this CBM",
+                           0, G_MAXUINT16, 0,
+                           G_PARAM_READWRITE);
+
+    g_object_class_install_properties (object_class, PROP_LAST, properties);
+}
+
+guint16
+mm_base_cbm_get_serial (MMBaseCbm *self)
+{
+    return self->priv->serial;
+}
+
+guint16
+mm_base_cbm_get_channel (MMBaseCbm *self)
+{
+    return mm_gdbus_cbm_get_channel (MM_GDBUS_CBM (self));
+}
diff --git a/src/mm-base-cbm.h b/src/mm-base-cbm.h
new file mode 100644
index 00000000..538cd9d1
--- /dev/null
+++ b/src/mm-base-cbm.h
@@ -0,0 +1,81 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2024 Guido Günther <agx@sigxcpu.org>
+ */
+
+#ifndef MM_BASE_CBM_H
+#define MM_BASE_CBM_H
+
+#include <glib.h>
+#include <glib-object.h>
+
+#define _LIBMM_INSIDE_MM
+#include <libmm-glib.h>
+
+#include "mm-cbm-part.h"
+#include "mm-base-modem.h"
+
+/*****************************************************************************/
+
+#define MM_TYPE_BASE_CBM            (mm_base_cbm_get_type ())
+#define MM_BASE_CBM(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), MM_TYPE_BASE_CBM, MMBaseCbm))
+#define MM_BASE_CBM_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  MM_TYPE_BASE_CBM, MMBaseCbmClass))
+#define MM_IS_BASE_CBM(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MM_TYPE_BASE_CBM))
+#define MM_IS_BASE_CBM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  MM_TYPE_BASE_CBM))
+#define MM_BASE_CBM_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  MM_TYPE_BASE_CBM, MMBaseCbmClass))
+
+typedef struct _MMBaseCbm MMBaseCbm;
+typedef struct _MMBaseCbmClass MMBaseCbmClass;
+typedef struct _MMBaseCbmPrivate MMBaseCbmPrivate;
+
+#define MM_BASE_CBM_PATH       "cbm-path"
+#define MM_BASE_CBM_CONNECTION "cbm-connection"
+#define MM_BASE_CBM_MODEM      "cbm-modem"
+#define MM_BASE_CBM_MAX_PARTS  "cbm-max-parts"
+#define MM_BASE_CBM_SERIAL     "cbm-serial"
+
+struct _MMBaseCbm {
+    MmGdbusCbmSkeleton parent;
+    MMBaseCbmPrivate *priv;
+};
+
+struct _MMBaseCbmClass {
+    MmGdbusCbmSkeletonClass parent;
+};
+
+GType mm_base_cbm_get_type (void);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (MMBaseCbm, g_object_unref)
+
+MMBaseCbm *mm_base_cbm_new       (MMBaseModem *modem);
+gboolean   mm_base_cbm_take_part (MMBaseCbm *self,
+                                  MMCbmPart *part,
+                                  GError **error);
+MMBaseCbm *mm_base_cbm_new_with_part (MMBaseModem *modem,
+                                      MMCbmState state,
+                                      guint max_parts,
+                                      MMCbmPart *first_part,
+                                      GError **error);
+
+void         mm_base_cbm_export         (MMBaseCbm *self);
+void         mm_base_cbm_unexport       (MMBaseCbm *self);
+const gchar *mm_base_cbm_get_path       (MMBaseCbm *self);
+
+gboolean     mm_base_cbm_has_part_num   (MMBaseCbm *self,
+                                         guint      part_num);
+GList       *mm_base_cbm_get_parts      (MMBaseCbm *self);
+guint16      mm_base_cbm_get_serial     (MMBaseCbm *self);
+guint16      mm_base_cbm_get_channel    (MMBaseCbm *self);
+
+gboolean     mm_base_cbm_is_complete    (MMBaseCbm *self);
+
+#endif /* MM_BASE_CBM_H */
diff --git a/src/mm-cbm-list.c b/src/mm-cbm-list.c
new file mode 100644
index 00000000..b86246a6
--- /dev/null
+++ b/src/mm-cbm-list.c
@@ -0,0 +1,402 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2024 Guido Günther <agx@sigxcpu.org>
+ *
+ * based on mm-sms-list.c which is
+ *
+ * Copyright (C) 2012 Google, Inc.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+
+#include <ModemManager.h>
+#define _LIBMM_INSIDE_MM
+#include <libmm-glib.h>
+
+#include "mm-iface-modem-messaging.h"
+#include "mm-cbm-list.h"
+#include "mm-base-cbm.h"
+#include "mm-log-object.h"
+
+static void log_object_iface_init (MMLogObjectInterface *iface);
+
+G_DEFINE_TYPE_EXTENDED (MMCbmList, mm_cbm_list, G_TYPE_OBJECT, 0,
+                        G_IMPLEMENT_INTERFACE (MM_TYPE_LOG_OBJECT, log_object_iface_init))
+
+enum {
+    PROP_0,
+    PROP_MODEM,
+    PROP_LAST
+};
+static GParamSpec *properties[PROP_LAST];
+
+enum {
+    SIGNAL_ADDED,
+    SIGNAL_DELETED,
+    SIGNAL_LAST
+};
+static guint signals[SIGNAL_LAST];
+
+struct _MMCbmListPrivate {
+    /* The owner modem */
+    MMBaseModem *modem;
+    /* List of cbm objects */
+    GList *list;
+};
+
+/*****************************************************************************/
+
+guint
+mm_cbm_list_get_count (MMCbmList *self)
+{
+    return g_list_length (self->priv->list);
+}
+
+GStrv
+mm_cbm_list_get_paths (MMCbmList *self)
+{
+    GStrv path_list = NULL;
+    GList *l;
+    guint i;
+
+    path_list = g_new0 (gchar *, 1 + g_list_length (self->priv->list));
+    for (i = 0, l = self->priv->list; l; l = g_list_next (l)) {
+        const gchar *path;
+
+        /* Don't try to add NULL paths (not yet exported CBM objects) */
+        path = mm_base_cbm_get_path (MM_BASE_CBM (l->data));
+        if (path)
+            path_list[i++] = g_strdup (path);
+    }
+
+    return path_list;
+}
+
+/*****************************************************************************/
+
+gboolean
+mm_cbm_list_delete_cbm_finish (MMCbmList *self,
+                               GAsyncResult *res,
+                               GError **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static guint
+cmp_cbm_by_path (MMBaseCbm *cbm,
+                 const gchar *path)
+{
+    return g_strcmp0 (mm_base_cbm_get_path (cbm), path);
+}
+
+void
+mm_cbm_list_delete_cbm (MMCbmList *self,
+                        const gchar *cbm_path,
+                        GAsyncReadyCallback callback,
+                        gpointer user_data)
+{
+    g_autoptr (GTask) task = NULL;
+    MMBaseCbm *cbm;
+    GList *l;
+
+    l = g_list_find_custom (self->priv->list,
+                            (gpointer)cbm_path,
+                            (GCompareFunc)cmp_cbm_by_path);
+    if (!l) {
+        g_task_report_new_error (self,
+                                 callback,
+                                 user_data,
+                                 mm_cbm_list_delete_cbm,
+                                 MM_CORE_ERROR,
+                                 MM_CORE_ERROR_NOT_FOUND,
+                                 "No CBM found with path '%s'",
+                                 cbm_path);
+        return;
+    }
+    cbm = MM_BASE_CBM (l->data);
+
+    /* Although this could be done sync we use a task to provide the
+     * async API pattern like other operations */
+    task = g_task_new (self, NULL, callback, user_data);
+
+    self->priv->list = g_list_delete_link (self->priv->list, l);
+
+    mm_base_cbm_unexport (cbm);
+    g_object_unref (cbm);
+
+    g_signal_emit (self, signals[SIGNAL_DELETED], 0, cbm_path);
+    g_task_return_boolean (task, TRUE);
+}
+
+
+/*****************************************************************************/
+
+void
+mm_cbm_list_add_cbm (MMCbmList *self,
+                     MMBaseCbm *cbm)
+{
+    self->priv->list = g_list_prepend (self->priv->list, g_object_ref (cbm));
+    g_signal_emit (self, signals[SIGNAL_ADDED], 0,
+                   mm_base_cbm_get_path (cbm),
+                   FALSE);
+}
+
+/*****************************************************************************/
+
+typedef struct {
+    guint16 serial;
+    guint16 channel;
+} PartIdAndSerial;
+
+static guint
+cmp_cbm_by_serial_and_id (MMBaseCbm *cbm,
+                          PartIdAndSerial *ctx)
+{
+    return !(mm_base_cbm_get_serial (cbm) == ctx->serial &&
+             mm_base_cbm_get_channel (cbm) == ctx->channel);
+}
+
+static gboolean
+take_part (MMCbmList *self,
+           MMCbmPart *part,
+           MMCbmState state,
+           GError **error)
+{
+    GList *l;
+    MMBaseCbm *cbm;
+    PartIdAndSerial cmp;
+
+    cmp = (PartIdAndSerial){
+        .serial = mm_cbm_part_get_serial (part),
+        .channel = mm_cbm_part_get_channel (part),
+    };
+    l = g_list_find_custom (self->priv->list,
+                            &cmp,
+                            (GCompareFunc)cmp_cbm_by_serial_and_id);
+    if (l) {
+        /* Try to take the part */
+        mm_obj_dbg (self, "found existing multipart CBM object with serial '%u' and id '%u': adding new part",
+                    cmp.serial, cmp.channel);
+        return mm_base_cbm_take_part (MM_BASE_CBM (l->data), part, error);
+    }
+
+    /* Create new cbm */
+    cbm = mm_base_cbm_new_with_part (self->priv->modem,
+                                     state,
+                                     mm_cbm_part_get_num_parts (part),
+                                     part,
+                                     error);
+    if (!cbm)
+        return FALSE;
+
+    mm_obj_dbg (self, "creating new multipart CBM object: need to receive %u parts with serial '%u' and id '%u'",
+                mm_cbm_part_get_num_parts (part), cmp.serial, cmp.channel);
+
+    self->priv->list = g_list_prepend (self->priv->list, cbm);
+    g_signal_emit (self, signals[SIGNAL_ADDED], 0,
+                   mm_base_cbm_get_path (cbm),
+                   (state == MM_CBM_STATE_RECEIVED ||
+                    state == MM_CBM_STATE_RECEIVING));
+
+    return TRUE;
+}
+
+typedef struct {
+    guint16 serial;
+    guint16 channel;
+    guint8  part_num;
+} PartIdSerialAndNum;
+
+static guint
+cmp_cbm_by_serial_id_and_part_num (MMBaseCbm          *cbm,
+                                   PartIdSerialAndNum *ctx)
+{
+    return !(mm_base_cbm_get_serial (cbm) == ctx->serial &&
+             mm_base_cbm_get_channel (cbm) == ctx->channel &&
+             mm_base_cbm_has_part_num (cbm, ctx->part_num));
+}
+
+gboolean
+mm_cbm_list_has_part (MMCbmList *self,
+                      guint16    serial,
+                      guint16    channel,
+                      guint8     part_num)
+{
+    PartIdSerialAndNum ctx = {
+        .channel = channel,
+        .serial = serial,
+        .part_num = part_num
+    };
+
+    return !!g_list_find_custom (self->priv->list,
+                                 &ctx,
+                                 (GCompareFunc)cmp_cbm_by_serial_id_and_part_num);
+}
+
+gboolean
+mm_cbm_list_take_part (MMCbmList *self,
+                       MMCbmPart *part,
+                       MMCbmState state,
+                       GError   **error)
+{
+    /* Ensure we don't have already taken a part with the same index */
+    if (mm_cbm_list_has_part (self,
+                              mm_cbm_part_get_serial (part),
+                              mm_cbm_part_get_channel (part),
+                              mm_cbm_part_get_part_num (part))) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_FAILED,
+                     "A part %u with serial %u and id %u and was already taken",
+                     mm_cbm_part_get_part_num (part),
+                     mm_cbm_part_get_serial (part),
+                     mm_cbm_part_get_channel (part));
+        return FALSE;
+    }
+
+    return take_part (self, part, state, error);
+}
+
+/*****************************************************************************/
+
+static gchar *
+log_object_build_id (MMLogObject *_self)
+{
+    return g_strdup ("cbm-list");
+}
+
+/*****************************************************************************/
+
+MMCbmList *
+mm_cbm_list_new (MMBaseModem *modem)
+{
+    /* Create the object */
+    return g_object_new  (MM_TYPE_CBM_LIST,
+                          MM_CBM_LIST_MODEM, modem,
+                          NULL);
+}
+
+static void
+set_property (GObject *object,
+              guint prop_id,
+              const GValue *value,
+              GParamSpec *pspec)
+{
+    MMCbmList *self = MM_CBM_LIST (object);
+
+    switch (prop_id) {
+    case PROP_MODEM:
+        g_clear_object (&self->priv->modem);
+        self->priv->modem = g_value_dup_object (value);
+        if (self->priv->modem) {
+            /* Set owner ID */
+            mm_log_object_set_owner_id (MM_LOG_OBJECT (self),
+                                        mm_log_object_get_id (MM_LOG_OBJECT (self->priv->modem)));
+        }
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+get_property (GObject *object,
+              guint prop_id,
+              GValue *value,
+              GParamSpec *pspec)
+{
+    MMCbmList *self = MM_CBM_LIST (object);
+
+    switch (prop_id) {
+    case PROP_MODEM:
+        g_value_set_object (value, self->priv->modem);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+        break;
+    }
+}
+
+static void
+mm_cbm_list_init (MMCbmList *self)
+{
+    /* Initialize private data */
+    self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
+                                              MM_TYPE_CBM_LIST,
+                                              MMCbmListPrivate);
+}
+
+static void
+dispose (GObject *object)
+{
+    MMCbmList *self = MM_CBM_LIST (object);
+
+    g_clear_object (&self->priv->modem);
+    g_list_free_full (self->priv->list, g_object_unref);
+    self->priv->list = NULL;
+
+    G_OBJECT_CLASS (mm_cbm_list_parent_class)->dispose (object);
+}
+
+static void
+log_object_iface_init (MMLogObjectInterface *iface)
+{
+    iface->build_id = log_object_build_id;
+}
+
+static void
+mm_cbm_list_class_init (MMCbmListClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+    g_type_class_add_private (object_class, sizeof (MMCbmListPrivate));
+
+    /* Virtual methods */
+    object_class->get_property = get_property;
+    object_class->set_property = set_property;
+    object_class->dispose = dispose;
+
+    /* Properties */
+    properties[PROP_MODEM] =
+        g_param_spec_object (MM_CBM_LIST_MODEM,
+                             "Modem",
+                             "The Modem which owns this CBM list",
+                             MM_TYPE_BASE_MODEM,
+                             G_PARAM_READWRITE);
+    g_object_class_install_property (object_class, PROP_MODEM, properties[PROP_MODEM]);
+
+    /* Signals */
+    signals[SIGNAL_ADDED] =
+        g_signal_new (MM_CBM_ADDED,
+                      G_OBJECT_CLASS_TYPE (object_class),
+                      G_SIGNAL_RUN_FIRST,
+                      G_STRUCT_OFFSET (MMCbmListClass, cbm_added),
+                      NULL, NULL,
+                      g_cclosure_marshal_generic,
+                      G_TYPE_NONE, 2, G_TYPE_STRING, G_TYPE_BOOLEAN);
+
+    signals[SIGNAL_DELETED] =
+        g_signal_new (MM_CBM_DELETED,
+                      G_OBJECT_CLASS_TYPE (object_class),
+                      G_SIGNAL_RUN_FIRST,
+                      G_STRUCT_OFFSET (MMCbmListClass, cbm_deleted),
+                      NULL, NULL,
+                      g_cclosure_marshal_generic,
+                      G_TYPE_NONE, 1, G_TYPE_STRING);
+}
diff --git a/src/mm-cbm-list.h b/src/mm-cbm-list.h
new file mode 100644
index 00000000..79a48878
--- /dev/null
+++ b/src/mm-cbm-list.h
@@ -0,0 +1,86 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2024 Guido Günther <agx@sigxcpu.org>
+ */
+
+#ifndef MM_CBM_LIST_H
+#define MM_CBM_LIST_H
+
+#include <glib.h>
+#include <glib-object.h>
+
+#include "mm-base-modem.h"
+#include "mm-base-cbm.h"
+#include "mm-cbm-part.h"
+
+#define MM_TYPE_CBM_LIST            (mm_cbm_list_get_type ())
+#define MM_CBM_LIST(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), MM_TYPE_CBM_LIST, MMCbmList))
+#define MM_CBM_LIST_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  MM_TYPE_CBM_LIST, MMCbmListClass))
+#define MM_IS_CBM_LIST(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MM_TYPE_CBM_LIST))
+#define MM_IS_CBM_LIST_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  MM_TYPE_CBM_LIST))
+#define MM_CBM_LIST_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  MM_TYPE_CBM_LIST, MMCbmListClass))
+
+typedef struct _MMCbmList MMCbmList;
+typedef struct _MMCbmListClass MMCbmListClass;
+typedef struct _MMCbmListPrivate MMCbmListPrivate;
+
+#define MM_CBM_LIST_MODEM "cbm-list-modem"
+
+#define MM_CBM_ADDED   "cbm-added"
+#define MM_CBM_DELETED "cbm-deleted"
+
+struct _MMCbmList {
+    GObject parent;
+    MMCbmListPrivate *priv;
+};
+
+struct _MMCbmListClass {
+    GObjectClass parent;
+
+    /* Signals */
+    void (* cbm_added)    (MMCbmList *self,
+                           const gchar *cbm_path);
+    void (* cbm_deleted)  (MMCbmList *self,
+                           const gchar *sms_path);
+};
+
+GType mm_cbm_list_get_type (void);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (MMCbmList, g_object_unref)
+
+MMCbmList *mm_cbm_list_new (MMBaseModem *modem);
+
+GStrv mm_cbm_list_get_paths (MMCbmList *self);
+guint mm_cbm_list_get_count (MMCbmList *self);
+
+gboolean mm_cbm_list_has_part (MMCbmList *self,
+                               guint16    serial,
+                               guint16    message_id,
+                               guint8     part_num);
+
+gboolean mm_cbm_list_take_part (MMCbmList *self,
+                                MMCbmPart *part,
+                                MMCbmState state,
+                                GError **error);
+
+void mm_cbm_list_add_cbm (MMCbmList *self,
+                          MMBaseCbm *cbm);
+
+void     mm_cbm_list_delete_cbm        (MMCbmList *self,
+                                        const gchar *cbm_path,
+                                        GAsyncReadyCallback callback,
+                                        gpointer user_data);
+gboolean mm_cbm_list_delete_cbm_finish (MMCbmList *self,
+                                        GAsyncResult *res,
+                                        GError **error);
+
+#endif /* MM_CBM_LIST_H */
diff --git a/src/mm-iface-modem-cell-broadcast.c b/src/mm-iface-modem-cell-broadcast.c
new file mode 100644
index 00000000..8e5af67c
--- /dev/null
+++ b/src/mm-iface-modem-cell-broadcast.c
@@ -0,0 +1,654 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2024 Guido Günther <agx@sigxcpu.org>n
+ */
+
+#include <ModemManager.h>
+#define _LIBMM_INSIDE_MM
+#include <libmm-glib.h>
+
+#include "mm-iface-modem.h"
+#include "mm-iface-modem-cell-broadcast.h"
+#include "mm-cbm-list.h"
+#include "mm-log-object.h"
+#include "mm-error-helpers.h"
+#include "mm-modem-helpers.h"
+
+#define SUPPORT_CHECKED_TAG "cell-broadcast-support-checked-tag"
+#define SUPPORTED_TAG       "cell-broadcast-supported-tag"
+
+static GQuark support_checked_quark;
+static GQuark supported_quark;
+
+G_DEFINE_INTERFACE (MMIfaceModemCellBroadcast, mm_iface_modem_cell_broadcast, MM_TYPE_IFACE_MODEM)
+
+/*****************************************************************************/
+
+void
+mm_iface_modem_cell_broadcast_bind_simple_status (MMIfaceModemCellBroadcast *self,
+                                                  MMSimpleStatus *status)
+{
+}
+
+/*****************************************************************************/
+
+typedef struct {
+    MmGdbusModemCellBroadcast *skeleton;
+    GDBusMethodInvocation *invocation;
+    MMIfaceModemCellBroadcast *self;
+    gchar                 *path;
+} HandleDeleteContext;
+
+static void
+handle_delete_context_free (HandleDeleteContext *ctx)
+{
+    g_object_unref (ctx->skeleton);
+    g_object_unref (ctx->invocation);
+    g_object_unref (ctx->self);
+    g_free (ctx->path);
+    g_slice_free (HandleDeleteContext, ctx);
+}
+
+static void
+handle_delete_ready (MMCbmList           *list,
+                     GAsyncResult        *res,
+                     HandleDeleteContext *ctx)
+{
+    GError *error = NULL;
+
+    if (!mm_cbm_list_delete_cbm_finish (list, res, &error)) {
+        mm_obj_warn (ctx->self, "failed deleting CBM message '%s': %s", ctx->path, error->message);
+        mm_dbus_method_invocation_take_error (ctx->invocation, error);
+    } else {
+        mm_obj_info (ctx->self, "deleted CBM message '%s'", ctx->path);
+        mm_gdbus_modem_cell_broadcast_complete_delete (ctx->skeleton, ctx->invocation);
+    }
+    handle_delete_context_free (ctx);
+}
+
+static void
+handle_delete_auth_ready (MMBaseModem         *self,
+                          GAsyncResult        *res,
+                          HandleDeleteContext *ctx)
+{
+    g_autoptr(MMCbmList)  list = NULL;
+    GError               *error = NULL;
+
+    if (!mm_base_modem_authorize_finish (self, res, &error)) {
+        mm_dbus_method_invocation_take_error (ctx->invocation, error);
+        handle_delete_context_free (ctx);
+        return;
+    }
+
+    /* We do allow deleting CBMs while enabling or disabling, it doesn't
+     * interfere with the state transition logic to do so. The main reason to allow
+     * this is that during modem enabling we're emitting "Added" signals before we
+     * reach the enabled state, and so users listening to the signal may want to
+     * delete the CBM message as soon as it's read. */
+    if (mm_iface_modem_abort_invocation_if_state_not_reached (MM_IFACE_MODEM (self),
+                                                              ctx->invocation,
+                                                              MM_MODEM_STATE_DISABLING)) {
+        handle_delete_context_free (ctx);
+        return;
+    }
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_CELL_BROADCAST_CBM_LIST, &list,
+                  NULL);
+    if (!list) {
+        mm_dbus_method_invocation_return_error_literal (ctx->invocation, MM_CORE_ERROR, MM_CORE_ERROR_WRONG_STATE,
+                                                        "Cannot delete CBM: missing CBM list");
+        handle_delete_context_free (ctx);
+        return;
+    }
+
+    mm_obj_info (self, "processing user request to delete CBM message '%s'...", ctx->path);
+    mm_cbm_list_delete_cbm (list,
+                            ctx->path,
+                            (GAsyncReadyCallback)handle_delete_ready,
+                            ctx);
+}
+
+static gboolean
+handle_delete (MmGdbusModemCellBroadcast *skeleton,
+               GDBusMethodInvocation *invocation,
+               const gchar           *path,
+               MMIfaceModemCellBroadcast *self)
+{
+    HandleDeleteContext *ctx;
+
+    ctx = g_slice_new0 (HandleDeleteContext);
+    ctx->skeleton = g_object_ref (skeleton);
+    ctx->invocation = g_object_ref (invocation);
+    ctx->self = g_object_ref (self);
+    ctx->path = g_strdup (path);
+
+    mm_base_modem_authorize (MM_BASE_MODEM (self),
+                             invocation,
+                             MM_AUTHORIZATION_CELL_BROADCAST,
+                             (GAsyncReadyCallback)handle_delete_auth_ready,
+                             ctx);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static gboolean
+handle_list (MmGdbusModemCellBroadcast *skeleton,
+             GDBusMethodInvocation *invocation,
+             MMIfaceModemCellBroadcast *self)
+{
+    g_auto(GStrv)        paths = NULL;
+    g_autoptr(MMCbmList) list = NULL;
+
+    if (mm_iface_modem_abort_invocation_if_state_not_reached (MM_IFACE_MODEM (self),
+                                                              invocation,
+                                                              MM_MODEM_STATE_ENABLED))
+        return TRUE;
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_CELL_BROADCAST_CBM_LIST, &list,
+                  NULL);
+    if (!list) {
+        mm_dbus_method_invocation_return_error_literal (invocation, MM_CORE_ERROR, MM_CORE_ERROR_WRONG_STATE,
+                                                        "Cannot list CBM: missing CBM list");
+        return TRUE;
+    }
+
+    mm_obj_info (self, "processing user request to list CBM messages...");
+    paths = mm_cbm_list_get_paths (list);
+    mm_gdbus_modem_cell_broadcast_complete_list (skeleton,
+                                                 invocation,
+                                                 (const gchar *const *)paths);
+    mm_obj_info (self, "reported %u CBM messages available", paths ? g_strv_length (paths) : 0);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+MMBaseCbm *
+mm_iface_modem_cell_broadcast_create_cbm (MMIfaceModemCellBroadcast *self)
+{
+    g_assert (MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->create_cbm != NULL);
+
+    return MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->create_cbm (self);
+}
+
+/*****************************************************************************/
+
+typedef struct _InitializationContext InitializationContext;
+static void interface_initialization_step (GTask *task);
+
+typedef enum {
+    INITIALIZATION_STEP_FIRST,
+    INITIALIZATION_STEP_CHECK_SUPPORT,
+    INITIALIZATION_STEP_FAIL_IF_UNSUPPORTED,
+    INITIALIZATION_STEP_LAST
+} InitializationStep;
+
+struct _InitializationContext {
+    MmGdbusModemCellBroadcast *skeleton;
+    InitializationStep step;
+};
+
+static void
+initialization_context_free (InitializationContext *ctx)
+{
+    g_object_unref (ctx->skeleton);
+    g_free (ctx);
+}
+
+gboolean
+mm_iface_modem_cell_broadcast_initialize_finish (MMIfaceModemCellBroadcast *self,
+                                                 GAsyncResult *res,
+                                                 GError **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void
+check_support_ready (MMIfaceModemCellBroadcast *self,
+                     GAsyncResult *res,
+                     GTask *task)
+{
+    InitializationContext *ctx;
+    GError *error = NULL;
+
+    if (!MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->check_support_finish (self,
+                                                                                  res,
+                                                                                  &error)) {
+        if (error) {
+            /* This error shouldn't be treated as critical */
+            mm_obj_dbg (self, "cell broadcast support check failed: %s", error->message);
+            g_error_free (error);
+        }
+    } else {
+        /* CellBroadcast is supported! */
+        g_object_set_qdata (G_OBJECT (self),
+                            supported_quark,
+                            GUINT_TO_POINTER (TRUE));
+    }
+
+    /* Go on to next step */
+    ctx = g_task_get_task_data (task);
+    ctx->step++;
+    interface_initialization_step (task);
+}
+
+static void
+interface_initialization_step (GTask *task)
+{
+    MMIfaceModemCellBroadcast *self;
+    InitializationContext *ctx;
+
+    /* Don't run new steps if we're cancelled */
+    if (g_task_return_error_if_cancelled (task)) {
+        g_object_unref (task);
+        return;
+    }
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    switch (ctx->step) {
+    case INITIALIZATION_STEP_FIRST:
+        /* Setup quarks if we didn't do it before */
+        if (G_UNLIKELY (!support_checked_quark))
+            support_checked_quark = (g_quark_from_static_string (
+                                         SUPPORT_CHECKED_TAG));
+        if (G_UNLIKELY (!supported_quark))
+            supported_quark = (g_quark_from_static_string (
+                                   SUPPORTED_TAG));
+
+        ctx->step++;
+        /* fall through */
+
+    case INITIALIZATION_STEP_CHECK_SUPPORT:
+        if (!GPOINTER_TO_UINT (g_object_get_qdata (G_OBJECT (self),
+                                                   support_checked_quark))) {
+            /* Set the checked flag so that we don't run it again */
+            g_object_set_qdata (G_OBJECT (self),
+                                support_checked_quark,
+                                GUINT_TO_POINTER (TRUE));
+            /* Initially, assume we don't support it */
+            g_object_set_qdata (G_OBJECT (self),
+                                supported_quark,
+                                GUINT_TO_POINTER (FALSE));
+
+            if (MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->check_support &&
+                MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->check_support_finish) {
+                MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->check_support (
+                    self,
+                    (GAsyncReadyCallback)check_support_ready,
+                    task);
+                return;
+            }
+
+            /* If there is no implementation to check support, assume we DON'T
+             * support it. */
+        }
+        ctx->step++;
+        /* fall through */
+
+    case INITIALIZATION_STEP_FAIL_IF_UNSUPPORTED:
+        if (!GPOINTER_TO_UINT (g_object_get_qdata (G_OBJECT (self),
+                                                   supported_quark))) {
+            g_task_return_new_error (task,
+                                     MM_CORE_ERROR,
+                                     MM_CORE_ERROR_UNSUPPORTED,
+                                     "CellBroadcast not supported");
+            g_object_unref (task);
+            return;
+        }
+        ctx->step++;
+        /* fall through */
+
+    case INITIALIZATION_STEP_LAST:
+        /* We are done without errors! */
+        g_signal_connect (ctx->skeleton,
+                          "handle-delete",
+                          G_CALLBACK (handle_delete),
+                          self);
+        g_signal_connect (ctx->skeleton,
+                          "handle-list",
+                          G_CALLBACK (handle_list),
+                          self);
+
+        /* Finally, export the new interface */
+        mm_gdbus_object_skeleton_set_modem_cell_broadcast (MM_GDBUS_OBJECT_SKELETON (self),
+                                                          MM_GDBUS_MODEM_CELL_BROADCAST (ctx->skeleton));
+
+        g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+
+    default:
+        break;
+    }
+
+    g_assert_not_reached ();
+}
+
+void
+mm_iface_modem_cell_broadcast_initialize (MMIfaceModemCellBroadcast *self,
+                                          GCancellable *cancellable,
+                                          GAsyncReadyCallback callback,
+                                          gpointer user_data)
+{
+    InitializationContext *ctx;
+    MmGdbusModemCellBroadcast *skeleton = NULL;
+    GTask *task;
+
+    /* Did we already create it? */
+    g_object_get (self,
+                  MM_IFACE_MODEM_CELL_BROADCAST_DBUS_SKELETON, &skeleton,
+                  NULL);
+    if (!skeleton) {
+        skeleton = mm_gdbus_modem_cell_broadcast_skeleton_new ();
+        g_object_set (self,
+                      MM_IFACE_MODEM_CELL_BROADCAST_DBUS_SKELETON, skeleton,
+                      NULL);
+    }
+
+    /* Perform async initialization here */
+
+    ctx = g_new0 (InitializationContext, 1);
+    ctx->step = INITIALIZATION_STEP_FIRST;
+    ctx->skeleton = skeleton;
+
+    task = g_task_new (self, cancellable, callback, user_data);
+    g_task_set_task_data (task, ctx, (GDestroyNotify)initialization_context_free);
+
+    interface_initialization_step (task);
+}
+
+void
+mm_iface_modem_cell_broadcast_shutdown (MMIfaceModemCellBroadcast *self)
+{
+    /* Unexport DBus interface and remove the skeleton */
+    mm_gdbus_object_skeleton_set_modem_cell_broadcast (MM_GDBUS_OBJECT_SKELETON (self), NULL);
+    g_object_set (self,
+                  MM_IFACE_MODEM_CELL_BROADCAST_DBUS_SKELETON, NULL,
+                  NULL);
+}
+
+/*****************************************************************************/
+
+static void
+update_message_list (MmGdbusModemCellBroadcast *skeleton,
+                     MMCbmList *list)
+{
+    gchar **paths;
+
+    paths = mm_cbm_list_get_paths (list);
+    mm_gdbus_modem_cell_broadcast_set_cell_broadcasts (skeleton, (const gchar *const *)paths);
+    g_strfreev (paths);
+
+    g_dbus_interface_skeleton_flush (G_DBUS_INTERFACE_SKELETON (skeleton));
+}
+
+static void
+cbm_added (MMCbmList                 *list,
+           const gchar               *cbm_path,
+           gboolean                   received,
+           MmGdbusModemCellBroadcast *skeleton)
+{
+    update_message_list (skeleton, list);
+    mm_gdbus_modem_cell_broadcast_emit_added (skeleton, cbm_path);
+}
+
+static void
+cbm_deleted (MMCbmList             *list,
+             const gchar           *cbm_path,
+             MmGdbusModemCellBroadcast *skeleton)
+{
+    update_message_list (skeleton, list);
+    mm_gdbus_modem_cell_broadcast_emit_deleted (skeleton, cbm_path);
+}
+
+/*****************************************************************************/
+
+typedef struct _EnablingContext EnablingContext;
+static void interface_enabling_step (GTask *task);
+
+typedef enum {
+    ENABLING_STEP_FIRST,
+    ENABLING_STEP_SETUP_UNSOLICITED_EVENTS,
+    ENABLING_STEP_ENABLE_UNSOLICITED_EVENTS,
+    ENABLING_STEP_LAST
+} EnablingStep;
+
+struct _EnablingContext {
+    EnablingStep step;
+    MmGdbusModemCellBroadcast *skeleton;
+};
+
+static void
+enabling_context_free (EnablingContext *ctx)
+{
+    if (ctx->skeleton)
+        g_object_unref (ctx->skeleton);
+    g_free (ctx);
+}
+
+gboolean
+mm_iface_modem_cell_broadcast_enable_finish (MMIfaceModemCellBroadcast *self,
+                                             GAsyncResult *res,
+                                             GError **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void
+setup_unsolicited_events_ready (MMIfaceModemCellBroadcast *self,
+                                GAsyncResult *res,
+                                GTask *task)
+{
+    EnablingContext *ctx;
+    GError *error = NULL;
+
+    MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->setup_unsolicited_events_finish (self, res, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    /* Go on to next step */
+    ctx = g_task_get_task_data (task);
+    ctx->step++;
+    interface_enabling_step (task);
+}
+
+static void
+enable_unsolicited_events_ready (MMIfaceModemCellBroadcast *self,
+                                 GAsyncResult *res,
+                                 GTask *task)
+{
+    EnablingContext *ctx;
+    GError *error = NULL;
+
+    /* Not critical! */
+    if (!MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->enable_unsolicited_events_finish (self, res, &error)) {
+        mm_obj_dbg (self, "Can't enable unsolicited events: %s", error->message);
+        g_error_free (error);
+    }
+
+    /* Go on with next step */
+    ctx = g_task_get_task_data (task);
+    ctx->step++;
+    interface_enabling_step (task);
+}
+
+static void
+interface_enabling_step (GTask *task)
+{
+    MMIfaceModemCellBroadcast *self;
+    EnablingContext *ctx;
+
+    /* Don't run new steps if we're cancelled */
+    if (g_task_return_error_if_cancelled (task)) {
+        g_object_unref (task);
+        return;
+    }
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    switch (ctx->step) {
+    case ENABLING_STEP_FIRST: {
+        g_autoptr (MMCbmList) list = NULL;
+
+        list = mm_cbm_list_new (MM_BASE_MODEM (self));
+        g_object_set (self,
+                      MM_IFACE_MODEM_CELL_BROADCAST_CBM_LIST, list,
+                      NULL);
+
+        /* Connect to list's signals */
+        g_signal_connect (list,
+                          MM_CBM_ADDED,
+                          G_CALLBACK (cbm_added),
+                          ctx->skeleton);
+        g_signal_connect (list,
+                          MM_CBM_DELETED,
+                          G_CALLBACK (cbm_deleted),
+                          ctx->skeleton);
+        ctx->step++;
+    } /* fall through */
+
+    case ENABLING_STEP_SETUP_UNSOLICITED_EVENTS:
+        /* Allow setting up unsolicited events */
+        if (MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->setup_unsolicited_events &&
+            MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->setup_unsolicited_events_finish) {
+            MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->setup_unsolicited_events (
+                self,
+                (GAsyncReadyCallback)setup_unsolicited_events_ready,
+                task);
+            return;
+        }
+        ctx->step++;
+        /* fall through */
+
+    case ENABLING_STEP_ENABLE_UNSOLICITED_EVENTS:
+        /* Allow enabling unsolicited events */
+        if (MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->enable_unsolicited_events &&
+            MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->enable_unsolicited_events_finish) {
+            MM_IFACE_MODEM_CELL_BROADCAST_GET_IFACE (self)->enable_unsolicited_events (
+                self,
+                (GAsyncReadyCallback)enable_unsolicited_events_ready,
+                task);
+            return;
+        }
+        ctx->step++;
+        /* fall through */
+
+    case ENABLING_STEP_LAST:
+        /* We are done without errors! */
+        g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+
+    default:
+        break;
+    }
+
+    g_assert_not_reached ();
+}
+
+void
+mm_iface_modem_cell_broadcast_enable (MMIfaceModemCellBroadcast *self,
+                                      GCancellable *cancellable,
+                                      GAsyncReadyCallback callback,
+                                      gpointer user_data)
+{
+    EnablingContext *ctx;
+    GTask *task;
+
+    ctx = g_new0 (EnablingContext, 1);
+    ctx->step = ENABLING_STEP_FIRST;
+
+    task = g_task_new (self, cancellable, callback, user_data);
+    g_task_set_task_data (task, ctx, (GDestroyNotify)enabling_context_free);
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_CELL_BROADCAST_DBUS_SKELETON, &ctx->skeleton,
+                  NULL);
+    if (!ctx->skeleton) {
+        g_task_return_new_error (task,
+                                 MM_CORE_ERROR,
+                                 MM_CORE_ERROR_FAILED,
+                                 "Can't get interface skeleton");
+        g_object_unref (task);
+        return;
+    }
+
+    interface_enabling_step (task);
+}
+
+/*****************************************************************************/
+
+gboolean
+mm_iface_modem_cell_broadcast_take_part (MMIfaceModemCellBroadcast *self,
+                                         MMCbmPart                 *cbm_part,
+                                         MMCbmState                 state)
+{
+    g_autoptr(MMCbmList) list = NULL;
+    g_autoptr(GError)    error = NULL;
+    gboolean             added = FALSE;
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_CELL_BROADCAST_CBM_LIST, &list,
+                  NULL);
+
+    if (list) {
+        added = mm_cbm_list_take_part (list, cbm_part, state, &error);
+        if (!added)
+            mm_obj_dbg (self, "Can't take part in CBM list: %s", error->message);
+    }
+
+    /* If part wasn't taken, we need to free the part ourselves */
+    if (!added)
+        mm_cbm_part_free (cbm_part);
+
+    return added;
+}
+
+/*****************************************************************************/
+
+static void
+mm_iface_modem_cell_broadcast_default_init (MMIfaceModemCellBroadcastInterface *iface)
+{
+    static gsize initialized = 0;
+
+    if (!g_once_init_enter (&initialized))
+        return;
+
+    /* Properties */
+    g_object_interface_install_property (
+         iface,
+         g_param_spec_object (MM_IFACE_MODEM_CELL_BROADCAST_DBUS_SKELETON,
+                              "CellBroadcast DBus skeleton",
+                              "DBus skeleton for the CellBroadcast interface",
+                              MM_GDBUS_TYPE_MODEM_CELL_BROADCAST_SKELETON,
+                              G_PARAM_READWRITE));
+
+    g_object_interface_install_property (
+         iface,
+         g_param_spec_object (MM_IFACE_MODEM_CELL_BROADCAST_CBM_LIST,
+                              "CBM list",
+                              "List of CBM objects managed in the interface",
+                              MM_TYPE_CBM_LIST,
+                              G_PARAM_READWRITE));
+
+    g_once_init_leave (&initialized, 1);
+}
diff --git a/src/mm-iface-modem-cell-broadcast.h b/src/mm-iface-modem-cell-broadcast.h
new file mode 100644
index 00000000..5990b865
--- /dev/null
+++ b/src/mm-iface-modem-cell-broadcast.h
@@ -0,0 +1,120 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2024 Guido Günther <agx@sigxcpu.org>
+ */
+
+#ifndef MM_IFACE_MODEM_CELLBROADCAST_H
+#define MM_IFACE_MODEM_CELLBROADCAST_H
+
+#include <glib-object.h>
+#include <gio/gio.h>
+
+#define _LIBMM_INSIDE_MM
+#include <libmm-glib.h>
+
+#include "mm-cbm-part.h"
+#include "mm-base-cbm.h"
+
+#define MM_TYPE_IFACE_MODEM_CELL_BROADCAST mm_iface_modem_cell_broadcast_get_type ()
+G_DECLARE_INTERFACE (MMIfaceModemCellBroadcast, mm_iface_modem_cell_broadcast, MM, IFACE_MODEM_CELL_BROADCAST, MMIfaceModem)
+
+#define MM_IFACE_MODEM_CELL_BROADCAST_DBUS_SKELETON "iface-modem-cell-broadcast-dbus-skeleton"
+#define MM_IFACE_MODEM_CELL_BROADCAST_CBM_LIST      "iface-modem-cell-broadcast-cbm-list"
+
+struct _MMIfaceModemCellBroadcastInterface {
+    GTypeInterface g_iface;
+
+    /* Check for CellBroadcast support (async) */
+    void (* check_support) (MMIfaceModemCellBroadcast    *self,
+                            GAsyncReadyCallback           callback,
+                            gpointer                      user_data);
+    gboolean (* check_support_finish) (MMIfaceModemCellBroadcast *self,
+                                       GAsyncResult              *res,
+                                       GError                   **error);
+
+    /* Asynchronous setting up unsolicited CellBroadcast reception events */
+    void (* setup_unsolicited_events) (MMIfaceModemCellBroadcast *self,
+                                       GAsyncReadyCallback callback,
+                                       gpointer user_data);
+    gboolean (* setup_unsolicited_events_finish) (MMIfaceModemCellBroadcast *self,
+                                                  GAsyncResult *res,
+                                                  GError **error);
+
+    /* Asynchronous cleaning up of unsolicited CellBroadcast reception events */
+    void (* cleanup_unsolicited_events) (MMIfaceModemCellBroadcast *self,
+                                         GAsyncReadyCallback callback,
+                                         gpointer user_data);
+    gboolean (* cleanup_unsolicited_events_finish) (MMIfaceModemCellBroadcast *self,
+                                                    GAsyncResult *res,
+                                                    GError **error);
+
+    /* Asynchronous enabling unsolicited CellBroadcast reception events */
+    void (* enable_unsolicited_events) (MMIfaceModemCellBroadcast *self,
+                                        GAsyncReadyCallback callback,
+                                        gpointer user_data);
+    gboolean (* enable_unsolicited_events_finish) (MMIfaceModemCellBroadcast *self,
+                                                   GAsyncResult *res,
+                                                   GError **error);
+
+    /* Asynchronous disabling unsolicited CellBroadcast reception events */
+    void (* disable_unsolicited_events) (MMIfaceModemCellBroadcast *self,
+                                         GAsyncReadyCallback callback,
+                                         gpointer user_data);
+    gboolean (* disable_unsolicited_events_finish) (MMIfaceModemCellBroadcast *self,
+                                                    GAsyncResult *res,
+                                                    GError **error);
+
+    /* Create Cbm objects */
+    MMBaseCbm * (* create_cbm) (MMIfaceModemCellBroadcast *self);
+};
+
+/* Initialize CellBroadcast interface (async) */
+void     mm_iface_modem_cell_broadcast_initialize   (MMIfaceModemCellBroadcast *self,
+                                                     GCancellable *cancellable,
+                                                     GAsyncReadyCallback callback,
+                                                     gpointer user_data);
+gboolean mm_iface_modem_cell_broadcast_initialize_finish (MMIfaceModemCellBroadcast *self,
+                                                          GAsyncResult *res,
+                                                          GError **error);
+/* Enable CellBroadcast interface (async) */
+void     mm_iface_modem_cell_broadcast_enable        (MMIfaceModemCellBroadcast *self,
+                                                      GCancellable *cancellable,
+                                                      GAsyncReadyCallback callback,
+                                                      gpointer user_data);
+gboolean mm_iface_modem_cell_broadcast_enable_finish (MMIfaceModemCellBroadcast *self,
+                                                      GAsyncResult *res,
+                                                      GError **error);
+
+/* Disable CellBroadcast interface (async) */
+void     mm_iface_modem_cell_broadcast_disable        (MMIfaceModemCellBroadcast *self,
+                                                       GAsyncReadyCallback callback,
+                                                       gpointer user_data);
+gboolean mm_iface_modem_cell_broadcast_disable_finish (MMIfaceModemCellBroadcast *self,
+                                                       GAsyncResult *res,
+                                                       GError **error);
+/* Shutdown CellBroadcast interface */
+void mm_iface_modem_cell_broadcast_shutdown (MMIfaceModemCellBroadcast *self);
+
+/* Bind properties for simple GetStatus() */
+void mm_iface_modem_cell_broadcast_bind_simple_status (MMIfaceModemCellBroadcast *self,
+                                                       MMSimpleStatus *status);
+
+/* Report new CBM part */
+gboolean mm_iface_modem_cell_broadcast_take_part (MMIfaceModemCellBroadcast *self,
+                                                  MMCbmPart *cbm_part,
+                                                  MMCbmState state);
+
+/* CBM creation */
+MMBaseCbm *mm_iface_modem_cell_broadcast_create_cbm (MMIfaceModemCellBroadcast *self);
+
+#endif /* MM_IFACE_MODEM_CELLBROADCAST_H */