New API to enable/disable protocols; remove `ndpi_set_protocol_detection_bitmask2()` (#2853)

The main goal is not to have the bitmask depending on the total number
of protocols anymore: `NDPI_INTERNAL_PROTOCOL_BITMASK` depends only on
internal protocols, i.e. on `NDPI_MAX_INTERNAL_PROTOCOLS`, i.e.
custom-defined protocols are not counted.
See #2136

Keep the old data structure `NDPI_PROTOCOL_BITMASK` with the old
semantic.

Since we need to change the API (and all the application code...)
anyway, simplify the API: by default all the protocols are enabled.
If you need otherwise, please use `ndpi_init_detection_module_ext()`
instead of `ndpi_init_detection_module()` (you can find an example in
the `ndpiReader` code).

To update the application code you likely only need to remove these 3
lines from your code:
```
- NDPI_PROTOCOL_BITMASK all;
- NDPI_BITMASK_SET_ALL(all);
- ndpi_set_protocol_detection_bitmask2(ndpi_str, &all);
```

Removed an unused field and struct definition.

1 files changed, 15 insertions, 13 deletions

diff --git a/src/include/ndpi_api.h b/src/include/ndpi_api.h
index 8688fb2a4..a59a0925e 100644
--- a/src/include/ndpi_api.h
+++ b/src/include/ndpi_api.h
@@ -224,15 +224,28 @@ extern "C" {
    * it do not forget to call first ndpi_finalize_initialization()
    *
    * You can call this function multiple times, (i.e. to create multiple
-   * indipendent detection contexts) but all these calls MUST NOT run
+   * independent detection contexts) but all these calls MUST NOT run
    * in parallel
    *
-   * @g_ctx = global context associated to the new detection module; NULL if no global context is needed
+   * @par g_ctx = global context associated to the new detection module; NULL if no global context is needed
    * @return  the initialized detection module
    *
    */
   struct ndpi_detection_module_struct *ndpi_init_detection_module(struct ndpi_global_context *g_ctx);
 
+
+  /**
+   * Similar to `ndpi_init_detection_module` but you can also set the protocol bitmask
+   * By default, all protocols are enabled
+   *
+   * @par g_ctx = global context associated to the new detection module; NULL if no global context is needed
+   * @par detection_bitmask = protocol bitmask. If NULL, all protocols will be enabled
+   * @return  the initialized detection module
+   *
+   */
+  struct ndpi_detection_module_struct *ndpi_init_detection_module_ext(struct ndpi_global_context *g_ctx,
+                                                                      const NDPI_INTERNAL_PROTOCOL_BITMASK *detection_bitmask);
+
   /**
    * Completes the initialization (2nd step)
    *
@@ -268,17 +281,6 @@ extern "C" {
   void ndpi_exit_detection_module(struct ndpi_detection_module_struct *ndpi_struct);
 
   /**
-   * Sets the protocol bitmask2
-   *
-   * @par ndpi_struct        = the detection module
-   * @par detection_bitmask  = the protocol bitmask to set
-   * @return 0 if ok, -1 if error
-   *
-   */
-  int ndpi_set_protocol_detection_bitmask2(struct ndpi_detection_module_struct *ndpi_struct,
-					    const NDPI_PROTOCOL_BITMASK * detection_bitmask);
-
-  /**
    *  Function to be called before we give up with detection for a given flow.
    *  This function reduces the NDPI_UNKNOWN_PROTOCOL detection
    *