broadband-modem: don't assume the returned string is always hex-encoded

libmm-glib/mm-common-helpers.c

@@ -929,6 +929,31 @@ mm_utils_hexstr2bin (const gchar *hex, gsize *out_len)
 
 /* End from hostap */
 
+gboolean
+mm_utils_ishexstr (const gchar *hex)
+{
+    gsize len;
+    gsize i;
+
+    /* Length not multiple of 2? */
+    len = strlen (hex);
+    if (len % 2 != 0)
+        return FALSE;
+
+    for (i = 0; i < len; i++) {
+        /* Non-hex char? */
+        if (hex[i] >= '0' && hex[i] <= '9')
+            continue;
+        if (hex[i] >= 'a' && hex[i] <= 'f')
+            continue;
+        if (hex[i] >= 'A' && hex[i] <= 'F')
+            continue;
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
 gchar *
 mm_utils_bin2hexstr (const guint8 *bin, gsize len)
 {

libmm-glib/mm-common-helpers.h

@@ -99,6 +99,7 @@ const gchar *mm_sms_delivery_state_get_string_extended (guint delivery_state);
 gint      mm_utils_hex2byte   (const gchar *hex);
 gchar    *mm_utils_hexstr2bin (const gchar *hex, gsize *out_len);
 gchar    *mm_utils_bin2hexstr (const guint8 *bin, gsize len);
+gboolean  mm_utils_ishexstr   (const gchar *hex);
 
 gboolean  mm_utils_check_for_single_value (guint32 value);
 

src/mm-broadband-modem.c

@@ -4373,8 +4373,13 @@ decode_ussd_response (MMBroadbandModem *self,
     if (p)
         *p = '\0';
 
-    decoded = mm_iface_modem_3gpp_ussd_decode (MM_IFACE_MODEM_3GPP_USSD (self), str, error);
+    /* If reply doesn't seem to be hex; just return itself... */
+    if (!mm_utils_ishexstr (str))
+        decoded = g_strdup (str);
+    else
+        decoded = mm_iface_modem_3gpp_ussd_decode (MM_IFACE_MODEM_3GPP_USSD (self), str, error);
     g_strfreev (items);
+
     return decoded;
 }