cbm: Add parsing bits for cell broadcast messages

This allows to parse the CBMs parameters like channel, part number and
message text. We parse uncompressed GSM7 and UCS2 encodings as
described in 3GPP TS 23.038.

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

1 files changed, 69 insertions, 0 deletions

diff --git a/src/mm-cbm-part.h b/src/mm-cbm-part.h
new file mode 100644
index 00000000..f942ab0c
--- /dev/null
+++ b/src/mm-cbm-part.h
@@ -0,0 +1,69 @@
+/* -*- 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_PART_H
+#define MM_CBM_PART_H
+
+#include <glib.h>
+#include <ModemManager.h>
+
+#include "mm-sms-part.h"
+
+/* Serial number per ETSI TS 123 041 */
+#define CBM_SERIAL_GEO_SCOPE(serial)           (((serial) & 0xC000) >> 14)
+#define CBM_SERIAL_MESSAGE_CODE(serial)        (((serial) & 0x0FF0) >> 4)
+#define CBM_SERIAL_MESSAGE_CODE_UPDATE(serial) ((serial) & 0x000F)
+#define CBM_SERIAL_MESSAGE_CODE_ALERT(serial)  (!!((serial) & 0x2000))
+#define CBM_SERIAL_MESSAGE_CODE_POPUP(serial)  (!!((serial) & 0x1000))
+
+/**
+ * MMCbmGeoScope:
+ * @MM_CBM_GEO_SCOPE_CELL_IMMEDIATE: cell wide, immediate display
+ * @MM_CBM_GEO_SCOPE_PLMN: PLMN wide, normal display
+ * @MM_CBM_GEO_SCOPE_AREA: area wide, normal display
+ * @MM_CBM_GEO_SCOPE_CELL_NORMAL: cell wide, normal display
+ *
+ * The geographical area of which a CBM is unique and whether to display
+ * it immediately to the user.
+ */
+typedef enum _MMCbmGeoScope {
+    MM_CBM_GEO_SCOPE_CELL_IMMEDIATE = 0,
+    MM_CBM_GEO_SCOPE_PLMN           = 1,
+    MM_CBM_GEO_SCOPE_AREA           = 2,
+    MM_CBM_GEO_SCOPE_CELL_NORMAL    = 3,
+} MMCbmGeoScope;
+
+
+typedef struct _MMCbmPart MMCbmPart;
+
+MMCbmPart *mm_cbm_part_new_from_pdu        (const gchar   *hexpdu,
+                                            gpointer       log_object,
+                                            GError       **error);
+MMCbmPart *mm_cbm_part_new_from_binary_pdu (const guint8  *pdu,
+                                            gsize          pdu_len,
+                                            gpointer       log_object,
+                                            GError       **error);
+
+MMCbmPart  *mm_cbm_part_new (void);
+void        mm_cbm_part_free (MMCbmPart *part);
+
+guint       mm_cbm_part_get_part_num (MMCbmPart *part);
+guint       mm_cbm_part_get_num_parts (MMCbmPart *part);
+const char *mm_cbm_part_get_text (MMCbmPart *part);
+
+guint16     mm_cbm_part_get_serial (MMCbmPart *part);
+guint16     mm_cbm_part_get_channel (MMCbmPart *part);
+
+#endif