New API for library configuration

This is the first step into providing (more) configuration options in nDPI.

The idea is to have a simple way to configure (most of) nDPI: only one
function (`ndpi_set_config()`) to set any configuration parameters
(in the present or on in the future) and we try to keep this function
prototype as agnostic as possible.

You can configure the library:
* via API, using `ndpi_set_config()`
* via a configuration file, in a text format

This way, anytime we need to add a new configuration parameter:
* we don't need to add two public functions (a getter and a setter)
* we don't break API/ABI compatibility of the library; even changing
the parameter type (from integer to a list of integer, for example)
doesn't break the compatibility.

The complete list of configuration options is provided in
`doc/configuration_parameters.md`.

As a first example, two configuration knobs are provided:
* the ability to enable/disable the extraction of the sha1 fingerprint of
the TLS certificates.
* the upper limit on the number of packets per flow that will be subject
to inspection

1 files changed, 9 insertions, 0 deletions

diff --git a/src/include/ndpi_api.h b/src/include/ndpi_api.h
index 8bec8e3eb..3a5c7eccc 100644
--- a/src/include/ndpi_api.h
+++ b/src/include/ndpi_api.h
@@ -2246,6 +2246,15 @@ extern "C" {
 
   /* ******************************* */
 
+  ndpi_cfg_error ndpi_set_config(struct ndpi_detection_module_struct *ndpi_str,
+                                 const char *proto, const char *param, const char *value);
+  char *ndpi_get_config(struct ndpi_detection_module_struct *ndpi_str,
+			const char *proto, const char *param, char *buf, int buf_len);
+  char *ndpi_dump_config(struct ndpi_detection_module_struct *ndpi_str,
+			 FILE *fd);
+
+  /* ******************************* */
+
   /* Can't call libc functions from kernel space, define some stub instead */
 
 #define ndpi_isalpha(ch) (((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))