base-sms,sms-at: split AT-specific SMS code into MMSmsAt

Simplify MMBaseSms (making it easier to use from testcases) by
splitting the AT-specific code into MMSmsAt rather than keeping
it in the base class.

Signed-off-by: Dan Williams <dan@ioncontrol.co>

1 files changed, 835 insertions, 0 deletions

diff --git a/src/mm-sms-at.c b/src/mm-sms-at.c
new file mode 100644
index 00000000..3fc7c155
--- /dev/null
+++ b/src/mm-sms-at.c
@@ -0,0 +1,835 @@
+/* -*- 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) 2008 - 2009 Novell, Inc.
+ * Copyright (C) 2009 - 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Google, Inc.
+ * Copyright (C) 2025 Dan Williams <dan@ioncontrol.co>
+ */
+
+#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-sms-at.h"
+#include "mm-iface-modem-messaging.h"
+#include "mm-sms-part-3gpp.h"
+#include "mm-base-modem-at.h"
+#include "mm-log-object.h"
+
+G_DEFINE_TYPE (MMSmsAt, mm_sms_at, MM_TYPE_BASE_SMS)
+
+struct _MMSmsAtPrivate {
+    MMBaseModem *modem;
+};
+
+/*****************************************************************************/
+
+static gboolean
+sms_get_store_or_send_command (MMSmsAt  *self,
+                               MMSmsPart  *part,
+                               gboolean    text_or_pdu,   /* TRUE for PDU */
+                               gboolean    store_or_send, /* TRUE for send */
+                               gchar     **out_cmd,
+                               gchar     **out_msg_data,
+                               GError    **error)
+{
+    g_assert (out_cmd != NULL);
+    g_assert (out_msg_data != NULL);
+
+    if (!text_or_pdu) {
+        /* Text mode */
+        *out_cmd = g_strdup_printf ("+CMG%c=\"%s\"",
+                                    store_or_send ? 'S' : 'W',
+                                    mm_sms_part_get_number (part));
+        *out_msg_data = g_strdup_printf ("%s\x1a", mm_sms_part_get_text (part));
+    } else {
+        g_autofree gchar  *hex = NULL;
+        g_autofree guint8 *pdu = NULL;
+        guint              pdulen = 0;
+        guint              msgstart = 0;
+
+        /* AT+CMGW=<length>[, <stat>]<CR> PDU can be entered. <CTRL-Z>/<ESC> */
+
+        pdu = mm_sms_part_3gpp_get_submit_pdu (part, &pdulen, &msgstart, self, error);
+        if (!pdu)
+            /* 'error' should already be set */
+            return FALSE;
+
+        /* Convert PDU to hex */
+        hex = mm_utils_bin2hexstr (pdu, pdulen);
+        if (!hex) {
+            g_set_error (error,
+                         MM_CORE_ERROR,
+                         MM_CORE_ERROR_FAILED,
+                         "Not enough memory to send SMS PDU");
+            return FALSE;
+        }
+
+        /* CMGW/S length is the size of the PDU without SMSC information */
+        *out_cmd = g_strdup_printf ("+CMG%c=%d",
+                                    store_or_send ? 'S' : 'W',
+                                    pdulen - msgstart);
+        *out_msg_data = g_strdup_printf ("%s\x1a", hex);
+    }
+
+    return TRUE;
+}
+
+/*****************************************************************************/
+/* Store the SMS */
+
+typedef struct {
+    MMBaseModem    *modem;
+    MMIfacePortAt  *port;
+    MMSmsStorage    storage;
+    gboolean        need_unlock;
+    gboolean        use_pdu_mode;
+    GList          *current;
+    gchar          *msg_data;
+} SmsStoreContext;
+
+static void
+sms_store_context_free (SmsStoreContext *ctx)
+{
+    /* Unlock mem2 storage if we had the lock */
+    if (ctx->need_unlock) {
+        mm_iface_modem_messaging_unlock_storages (MM_IFACE_MODEM_MESSAGING (ctx->modem),
+                                                  FALSE,
+                                                  TRUE);
+    }
+    g_object_unref (ctx->port);
+    g_object_unref (ctx->modem);
+    g_free (ctx->msg_data);
+    g_slice_free (SmsStoreContext, ctx);
+}
+
+static gboolean
+sms_store_finish (MMBaseSms    *self,
+                  GAsyncResult  *res,
+                  GError       **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void sms_store_next_part (GTask *task);
+
+static void
+store_msg_data_ready (MMBaseModem  *modem,
+                      GAsyncResult *res,
+                      GTask        *task)
+{
+    SmsStoreContext *ctx;
+    const gchar     *response;
+    GError          *error = NULL;
+    gint             rv;
+    gint             idx;
+
+    response = mm_base_modem_at_command_full_finish (modem, res, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    /* Read the new part index from the reply */
+    rv = sscanf (response, "+CMGW: %d", &idx);
+    if (rv != 1 || idx < 0) {
+        g_task_return_new_error (task,
+                                 MM_CORE_ERROR,
+                                 MM_CORE_ERROR_FAILED,
+                                 "Couldn't read index of already stored part: "
+                                 "%d fields parsed",
+                                 rv);
+        g_object_unref (task);
+        return;
+    }
+
+    ctx = g_task_get_task_data (task);
+
+    /* Set the index in the part we hold */
+    mm_sms_part_set_index ((MMSmsPart *)ctx->current->data, (guint)idx);
+
+    ctx->current = g_list_next (ctx->current);
+    sms_store_next_part (task);
+}
+
+static void
+store_ready (MMBaseModem  *modem,
+             GAsyncResult *res,
+             GTask        *task)
+{
+    SmsStoreContext *ctx;
+    GError          *error = NULL;
+
+    mm_base_modem_at_command_full_finish (modem, res, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    ctx = g_task_get_task_data (task);
+
+    /* Send the actual message data.
+     * We send the data as 'raw' data because we do NOT want it to
+     * be treated as an AT command (i.e. we don't want it prefixed
+     * with AT+ and suffixed with <CR><LF>), plus, we want it to be
+     * sent right away (not queued after other AT commands). */
+    mm_base_modem_at_command_full (ctx->modem,
+                                   ctx->port,
+                                   ctx->msg_data,
+                                   10,
+                                   FALSE,
+                                   TRUE, /* raw */
+                                   NULL,
+                                   (GAsyncReadyCallback)store_msg_data_ready,
+                                   task);
+}
+
+static void
+sms_store_next_part (GTask *task)
+{
+    MMSmsAt        *self;
+    SmsStoreContext  *ctx;
+    GError           *error = NULL;
+    g_autofree gchar *cmd = NULL;
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    if (!ctx->current) {
+        /* Done we are */
+        g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+    }
+
+    g_clear_pointer (&ctx->msg_data, g_free);
+
+    if (!sms_get_store_or_send_command (self,
+                                        (MMSmsPart *)ctx->current->data,
+                                        ctx->use_pdu_mode,
+                                        FALSE,
+                                        &cmd,
+                                        &ctx->msg_data,
+                                        &error)) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    g_assert (cmd != NULL);
+    g_assert (ctx->msg_data != NULL);
+
+    mm_base_modem_at_command_full (ctx->modem,
+                                   ctx->port,
+                                   cmd,
+                                   10,
+                                   FALSE,
+                                   FALSE,  /* raw */
+                                   NULL,
+                                   (GAsyncReadyCallback)store_ready,
+                                   task);
+}
+
+static void
+store_lock_sms_storages_ready (MMIfaceModemMessaging *messaging,
+                               GAsyncResult     *res,
+                               GTask            *task)
+{
+    MMSmsAt       *self;
+    SmsStoreContext *ctx;
+    GError          *error = NULL;
+
+    if (!mm_iface_modem_messaging_lock_storages_finish (messaging, res, &error)) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    /* We are now locked. Whatever result we have here, we need to make sure
+     * we unlock the storages before finishing. */
+    ctx->need_unlock = TRUE;
+
+    /* Go on to store the parts */
+    ctx->current = mm_base_sms_get_parts (MM_BASE_SMS (self));
+    sms_store_next_part (task);
+}
+
+static void
+sms_store (MMBaseSms           *sms,
+           MMSmsStorage         storage,
+           GAsyncReadyCallback  callback,
+           gpointer             user_data)
+{
+    MMSmsAt         *self = MM_SMS_AT (sms);
+    SmsStoreContext *ctx;
+    GTask           *task;
+    MMIfacePortAt   *port;
+    GError          *error = NULL;
+
+    task = g_task_new (self, NULL, callback, user_data);
+
+    /* Select port for the operation */
+    port = mm_base_modem_peek_best_at_port (self->priv->modem, &error);
+    if (!port) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    /* Setup the context */
+    ctx = g_slice_new0 (SmsStoreContext);
+    ctx->modem = g_object_ref (self->priv->modem);
+    ctx->port = g_object_ref (port);
+    ctx->storage = storage;
+
+    /* Different ways to do it if on PDU or text mode */
+    g_assert (MM_IS_IFACE_MODEM_MESSAGING (self->priv->modem));
+    g_object_get (self->priv->modem,
+                  MM_IFACE_MODEM_MESSAGING_SMS_PDU_MODE, &ctx->use_pdu_mode,
+                  NULL);
+    g_task_set_task_data (task, ctx, (GDestroyNotify)sms_store_context_free);
+
+    /* First, lock storage to use */
+    mm_iface_modem_messaging_lock_storages (
+        MM_IFACE_MODEM_MESSAGING (self->priv->modem),
+        MM_SMS_STORAGE_UNKNOWN, /* none required for mem1 */
+        ctx->storage,
+        (GAsyncReadyCallback)store_lock_sms_storages_ready,
+        task);
+}
+
+/*****************************************************************************/
+/* Send the SMS */
+
+typedef struct {
+    MMBaseModem   *modem;
+    MMIfacePortAt *port;
+    gboolean       need_unlock;
+    gboolean       from_storage;
+    gboolean       use_pdu_mode;
+    GList         *current;
+    gchar         *msg_data;
+} SmsSendContext;
+
+static void
+sms_send_context_free (SmsSendContext *ctx)
+{
+    /* Unlock mem2 storage if we had the lock */
+    if (ctx->need_unlock) {
+        mm_iface_modem_messaging_unlock_storages (MM_IFACE_MODEM_MESSAGING (ctx->modem),
+                                                  FALSE,
+                                                  TRUE);
+    }
+    g_object_unref (ctx->port);
+    g_object_unref (ctx->modem);
+    g_free (ctx->msg_data);
+    g_slice_free (SmsSendContext, ctx);
+}
+
+static gboolean
+sms_send_finish (MMBaseSms     *self,
+                 GAsyncResult  *res,
+                 GError       **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void sms_send_next_part (GTask *task);
+
+static gint
+read_message_reference_from_reply (const gchar  *response,
+                                   GError      **error)
+{
+    gint rv = 0;
+    gint idx = -1;
+
+    if (strstr (response, "+CMGS"))
+        rv = sscanf (strstr (response, "+CMGS"), "+CMGS: %d", &idx);
+    else if (strstr (response, "+CMSS"))
+        rv = sscanf (strstr (response, "+CMSS"), "+CMSS: %d", &idx);
+
+    if (rv != 1 || idx < 0) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_FAILED,
+                     "Couldn't read message reference: "
+                     "%d fields parsed from response '%s'",
+                     rv, response);
+        return -1;
+    }
+
+    return idx;
+}
+
+static void
+send_generic_msg_data_ready (MMBaseModem  *modem,
+                             GAsyncResult *res,
+                             GTask        *task)
+{
+    SmsSendContext *ctx;
+    GError         *error = NULL;
+    const gchar    *response;
+    gint            message_reference;
+
+    response = mm_base_modem_at_command_full_finish (modem, res, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    message_reference = read_message_reference_from_reply (response, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    ctx = g_task_get_task_data (task);
+
+    mm_sms_part_set_message_reference ((MMSmsPart *)ctx->current->data,
+                                       (guint)message_reference);
+
+    ctx->current = g_list_next (ctx->current);
+    sms_send_next_part (task);
+}
+
+static void
+send_generic_ready (MMBaseModem  *modem,
+                    GAsyncResult *res,
+                    GTask        *task)
+{
+    SmsSendContext *ctx;
+    GError         *error = NULL;
+
+    mm_base_modem_at_command_full_finish (modem, res, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    ctx = g_task_get_task_data (task);
+
+    /* Send the actual message data.
+     * We send the data as 'raw' data because we do NOT want it to
+     * be treated as an AT command (i.e. we don't want it prefixed
+     * with AT+ and suffixed with <CR><LF>), plus, we want it to be
+     * sent right away (not queued after other AT commands). */
+    mm_base_modem_at_command_full (ctx->modem,
+                                   ctx->port,
+                                   ctx->msg_data,
+                                   MM_BASE_SMS_DEFAULT_SEND_TIMEOUT,
+                                   FALSE,
+                                   TRUE, /* raw */
+                                   NULL,
+                                   (GAsyncReadyCallback)send_generic_msg_data_ready,
+                                   task);
+}
+
+static void
+send_from_storage_ready (MMBaseModem  *modem,
+                         GAsyncResult *res,
+                         GTask        *task)
+{
+    MMSmsAt      *self;
+    SmsSendContext *ctx;
+    GError         *error = NULL;
+    const gchar    *response;
+    gint            message_reference;
+
+    self = g_task_get_source_object (task);
+    ctx  = g_task_get_task_data (task);
+
+    response = mm_base_modem_at_command_full_finish (modem, res, &error);
+    if (error) {
+        if (g_error_matches (error, MM_SERIAL_ERROR, MM_SERIAL_ERROR_RESPONSE_TIMEOUT)) {
+            g_task_return_error (task, error);
+            g_object_unref (task);
+            return;
+        }
+
+        mm_obj_dbg (self, "couldn't send SMS from storage: %s; trying generic send...", error->message);
+        g_error_free (error);
+
+        ctx->from_storage = FALSE;
+        sms_send_next_part (task);
+        return;
+    }
+
+    message_reference = read_message_reference_from_reply (response, &error);
+    if (error) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    mm_sms_part_set_message_reference ((MMSmsPart *)ctx->current->data,
+                                       (guint)message_reference);
+
+    ctx->current = g_list_next (ctx->current);
+    sms_send_next_part (task);
+}
+
+static void
+sms_send_next_part (GTask *task)
+{
+    MMSmsAt        *self;
+    SmsSendContext   *ctx;
+    GError           *error = NULL;
+    g_autofree gchar *cmd = NULL;
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    if (!ctx->current) {
+        /* Done we are */
+        g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+    }
+
+    /* Send from storage */
+    if (ctx->from_storage) {
+        cmd = g_strdup_printf ("+CMSS=%d", mm_sms_part_get_index ((MMSmsPart *)ctx->current->data));
+        mm_base_modem_at_command_full (ctx->modem,
+                                       ctx->port,
+                                       cmd,
+                                       MM_BASE_SMS_DEFAULT_SEND_TIMEOUT,
+                                       FALSE,
+                                       FALSE,
+                                       NULL,
+                                       (GAsyncReadyCallback)send_from_storage_ready,
+                                       task);
+        return;
+    }
+
+    /* Generic send */
+
+    g_clear_pointer (&ctx->msg_data, g_free);
+
+    if (!sms_get_store_or_send_command (self,
+                                        (MMSmsPart *)ctx->current->data,
+                                        ctx->use_pdu_mode,
+                                        TRUE,
+                                        &cmd,
+                                        &ctx->msg_data,
+                                        &error)) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    g_assert (cmd != NULL);
+    g_assert (ctx->msg_data != NULL);
+
+    /* no network involved in this initial AT command, so lower timeout */
+    mm_base_modem_at_command_full (ctx->modem,
+                                   ctx->port,
+                                   cmd,
+                                   10,
+                                   FALSE,
+                                   FALSE, /* raw */
+                                   NULL,
+                                   (GAsyncReadyCallback)send_generic_ready,
+                                   task);
+}
+
+static void
+send_lock_sms_storages_ready (MMIfaceModemMessaging *messaging,
+                              GAsyncResult          *res,
+                              GTask                 *task)
+{
+    MMSmsAt      *self;
+    SmsSendContext *ctx;
+    GError         *error = NULL;
+
+    if (!mm_iface_modem_messaging_lock_storages_finish (messaging, res, &error)) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    /* We are now locked. Whatever result we have here, we need to make sure
+     * we unlock the storages before finishing. */
+    ctx->need_unlock = TRUE;
+
+    /* Go on to send the parts */
+    ctx->current = mm_base_sms_get_parts (MM_BASE_SMS (self));
+    sms_send_next_part (task);
+}
+
+static void
+sms_send (MMBaseSms           *sms,
+          GAsyncReadyCallback  callback,
+          gpointer             user_data)
+{
+    MMSmsAt        *self = MM_SMS_AT (sms);
+    SmsSendContext *ctx;
+    GTask          *task;
+    MMIfacePortAt  *port;
+    GError         *error = NULL;
+
+    task = g_task_new (self, NULL, callback, user_data);
+
+    /* Select port for the operation */
+    port = mm_base_modem_peek_best_at_port (self->priv->modem, &error);
+    if (!port) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    /* Setup the context */
+    ctx = g_slice_new0 (SmsSendContext);
+    ctx->modem = g_object_ref (self->priv->modem);
+    ctx->port = g_object_ref (port);
+    g_task_set_task_data (task, ctx, (GDestroyNotify)sms_send_context_free);
+
+    /* If the SMS is STORED, try to send from storage */
+    ctx->from_storage = (mm_base_sms_get_storage (MM_BASE_SMS (self)) != MM_SMS_STORAGE_UNKNOWN);
+    if (ctx->from_storage) {
+        /* When sending from storage, first lock storage to use */
+        g_assert (MM_IS_IFACE_MODEM_MESSAGING (self->priv->modem));
+        mm_iface_modem_messaging_lock_storages (
+            MM_IFACE_MODEM_MESSAGING (self->priv->modem),
+            MM_SMS_STORAGE_UNKNOWN, /* none required for mem1 */
+            mm_base_sms_get_storage (MM_BASE_SMS (self)),
+            (GAsyncReadyCallback)send_lock_sms_storages_ready,
+            task);
+        return;
+    }
+
+    /* Different ways to do it if on PDU or text mode */
+    g_object_get (self->priv->modem,
+                  MM_IFACE_MODEM_MESSAGING_SMS_PDU_MODE, &ctx->use_pdu_mode,
+                  NULL);
+    ctx->current = mm_base_sms_get_parts (MM_BASE_SMS (self));
+    sms_send_next_part (task);
+}
+
+/*****************************************************************************/
+
+typedef struct {
+    MMBaseModem *modem;
+    gboolean     need_unlock;
+    GList       *current;
+    guint        n_failed;
+} SmsDeletePartsContext;
+
+static void
+sms_delete_parts_context_free (SmsDeletePartsContext *ctx)
+{
+    /* Unlock mem1 storage if we had the lock */
+    if (ctx->need_unlock) {
+        mm_iface_modem_messaging_unlock_storages (MM_IFACE_MODEM_MESSAGING (ctx->modem),
+                                                  TRUE,
+                                                  FALSE);
+    }
+    g_object_unref (ctx->modem);
+    g_slice_free (SmsDeletePartsContext, ctx);
+}
+
+static gboolean
+sms_delete_finish (MMBaseSms     *self,
+                   GAsyncResult  *res,
+                   GError       **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void delete_next_part (GTask *task);
+
+static void
+delete_part_ready (MMBaseModem  *modem,
+                   GAsyncResult *res,
+                   GTask        *task)
+{
+    MMSmsAt             *self;
+    SmsDeletePartsContext *ctx;
+    g_autoptr(GError)      error = NULL;
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    mm_base_modem_at_command_finish (modem, res, &error);
+    if (error) {
+        ctx->n_failed++;
+        mm_obj_dbg (self, "couldn't delete SMS part with index %u: %s",
+                    mm_sms_part_get_index ((MMSmsPart *)ctx->current->data),
+                    error->message);
+    }
+
+    /* We reset the index, as there is no longer that part */
+    mm_sms_part_set_index ((MMSmsPart *)ctx->current->data, SMS_PART_INVALID_INDEX);
+
+    ctx->current = g_list_next (ctx->current);
+    delete_next_part (task);
+}
+
+static void
+delete_next_part (GTask *task)
+{
+    SmsDeletePartsContext *ctx;
+    g_autofree gchar      *cmd = NULL;
+
+    ctx = g_task_get_task_data (task);
+
+    /* Skip non-stored parts */
+    while (ctx->current && (mm_sms_part_get_index ((MMSmsPart *)ctx->current->data) == SMS_PART_INVALID_INDEX))
+        ctx->current = g_list_next (ctx->current);
+
+    /* If all removed, we're done */
+    if (!ctx->current) {
+        if (ctx->n_failed > 0)
+            g_task_return_new_error (task,
+                                     MM_CORE_ERROR,
+                                     MM_CORE_ERROR_FAILED,
+                                     "Couldn't delete %u parts from this SMS",
+                                     ctx->n_failed);
+        else
+            g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+    }
+
+    cmd = g_strdup_printf ("+CMGD=%d", mm_sms_part_get_index ((MMSmsPart *)ctx->current->data));
+    mm_base_modem_at_command (ctx->modem,
+                              cmd,
+                              10,
+                              FALSE,
+                              (GAsyncReadyCallback)delete_part_ready,
+                              task);
+}
+
+static void
+delete_lock_sms_storages_ready (MMIfaceModemMessaging *messaging,
+                                GAsyncResult          *res,
+                                GTask                 *task)
+{
+    MMSmsAt             *self;
+    SmsDeletePartsContext *ctx;
+    GError                *error = NULL;
+
+    if (!mm_iface_modem_messaging_lock_storages_finish (messaging, res, &error)) {
+        g_task_return_error (task, error);
+        g_object_unref (task);
+        return;
+    }
+
+    self = g_task_get_source_object (task);
+    ctx = g_task_get_task_data (task);
+
+    /* We are now locked. Whatever result we have here, we need to make sure
+     * we unlock the storages before finishing. */
+    ctx->need_unlock = TRUE;
+
+    /* Go on deleting parts */
+    ctx->current = mm_base_sms_get_parts (MM_BASE_SMS (self));
+    delete_next_part (task);
+}
+
+static void
+sms_delete (MMBaseSms           *sms,
+            GAsyncReadyCallback  callback,
+            gpointer             user_data)
+{
+    MMSmsAt               *self = MM_SMS_AT (sms);
+    SmsDeletePartsContext *ctx;
+    GTask                 *task;
+
+    ctx = g_slice_new0 (SmsDeletePartsContext);
+    ctx->modem = g_object_ref (self->priv->modem);
+
+    task = g_task_new (self, NULL, callback, user_data);
+    g_task_set_task_data (task, ctx, (GDestroyNotify)sms_delete_parts_context_free);
+
+    if (mm_base_sms_get_storage (MM_BASE_SMS (self)) == MM_SMS_STORAGE_UNKNOWN) {
+        mm_obj_dbg (self, "not removing parts from non-stored SMS");
+        g_task_return_boolean (task, TRUE);
+        g_object_unref (task);
+        return;
+    }
+
+    /* Select specific storage to delete from */
+    mm_iface_modem_messaging_lock_storages (
+        MM_IFACE_MODEM_MESSAGING (self->priv->modem),
+        mm_base_sms_get_storage (MM_BASE_SMS (self)),
+        MM_SMS_STORAGE_UNKNOWN, /* none required for mem2 */
+        (GAsyncReadyCallback)delete_lock_sms_storages_ready,
+        task);
+}
+
+/*****************************************************************************/
+
+MMBaseSms *
+mm_sms_at_new (MMBaseModem *modem, gboolean is_3gpp)
+{
+    MMBaseSms *sms;
+
+    sms = MM_BASE_SMS (g_object_new (MM_TYPE_SMS_AT,
+                                     MM_BASE_SMS_MODEM, modem,
+                                     MM_BASE_SMS_IS_3GPP, is_3gpp,
+                                     NULL));
+    MM_SMS_AT (sms)->priv->modem = g_object_ref (modem);
+    return sms;
+}
+
+static void
+mm_sms_at_init (MMSmsAt *self)
+{
+    self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, MM_TYPE_SMS_AT, MMSmsAtPrivate);
+}
+
+static void
+dispose (GObject *object)
+{
+    MMSmsAt *self = MM_SMS_AT (object);
+
+    g_clear_object (&self->priv->modem);
+
+    G_OBJECT_CLASS (mm_sms_at_parent_class)->dispose (object);
+}
+
+static void
+mm_sms_at_class_init (MMSmsAtClass *klass)
+{
+    GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+    MMBaseSmsClass *base_sms_class = MM_BASE_SMS_CLASS (klass);
+
+    g_type_class_add_private (object_class, sizeof (MMSmsAtPrivate));
+
+    object_class->dispose = dispose;
+
+    base_sms_class->store = sms_store;
+    base_sms_class->store_finish = sms_store_finish;
+    base_sms_class->send = sms_send;
+    base_sms_class->send_finish = sms_send_finish;
+    base_sms_class->delete = sms_delete;
+    base_sms_class->delete_finish = sms_delete_finish;
+}