broadband-modem,modem-helpers: generalize call end regex creation

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

src/mm-broadband-modem.c

@@ -8473,8 +8473,7 @@ set_voice_in_call_unsolicited_events_handlers (MMBroadbandModem *self,
     g_autoptr(GRegex) in_call_event_regex = NULL;
     guint             i;
 
-    in_call_event_regex = g_regex_new ("\\r\\n(NO CARRIER|BUSY|NO ANSWER|NO DIALTONE)(\\r)?\\r\\n$",
-                                       G_REGEX_RAW | G_REGEX_OPTIMIZE, 0, NULL);
+    in_call_event_regex = mm_call_end_regex_get ();
 
     ports[0] = MM_PORT_SERIAL_AT (ports_ctx->primary);
     ports[1] = MM_PORT_SERIAL_AT (ports_ctx->secondary);

src/mm-modem-helpers.c

@@ -482,6 +482,20 @@ mm_at_quote_string (const gchar *input)
 
 /*****************************************************************************/
 
+GRegex *
+mm_call_end_regex_get (void)
+{
+    /* Example:
+     * <CR><LF>NO ANSWER<CR><LF>
+     */
+    return g_regex_new ("\\r\\n(NO CARRIER)|(BUSY)|(NO ANSWER)|(NO DIALTONE)\\r\\n",
+                        G_REGEX_DOLLAR_ENDONLY | G_REGEX_RAW | G_REGEX_OPTIMIZE,
+                        0,
+                        NULL);
+}
+
+/*****************************************************************************/
+
 GRegex *
 mm_voice_ring_regex_get (void)
 {

src/mm-modem-helpers.h

@@ -85,6 +85,12 @@ gchar *mm_bcd_to_string (const guint8 *bcd,
  */
 gchar *mm_at_quote_string (const gchar *input);
 
+/*****************************************************************************/
+/* CALL specific helpers and utilities */
+/*****************************************************************************/
+
+GRegex *mm_call_end_regex_get (void);
+
 /*****************************************************************************/
 /* VOICE specific helpers and utilities */
 /*****************************************************************************/