diff options
Diffstat (limited to 'example/ndpiReader.c')
| -rw-r--r-- | example/ndpiReader.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/example/ndpiReader.c b/example/ndpiReader.c index 2a7c3b232..3601978c0 100644 --- a/example/ndpiReader.c +++ b/example/ndpiReader.c @@ -31,6 +31,7 @@ #include <stdio.h> #include <stdlib.h> #include <getopt.h> +#include <float.h> /* FLT_EPSILON */ #ifdef WIN32 #include <winsock2.h> /* winsock.h is included automatically */ #include <windows.h> @@ -407,6 +408,22 @@ static void ndpiCheckIPMatch(char *testChar) { /********************** FUNCTIONS ********************* */ +static double ndpi_flow_get_byte_count_entropy(const uint32_t byte_count[256], + unsigned int num_bytes) +{ + int i; + double sum = 0.0; + + for(i=0; i<256; i++) { + double tmp = (double) byte_count[i] / (double) num_bytes; + + if(tmp > FLT_EPSILON) { + sum -= tmp * logf(tmp); + } + } + return(sum / log(2.0)); +} + /** * @brief Set main components necessary to the detection */ @@ -433,6 +450,8 @@ flowGetBDMeanandVariance(struct ndpi_flow_info* flow) { * Sum up the byte_count array for outbound and inbound flows, * if this flow is bidirectional */ + /* TODO: we could probably use ndpi_data_* generic functions to simplify the code and + to get rid of `ndpi_flow_get_byte_count_entropy()` */ if (!flow->bidirectional) { array = last_entropy->src2dst_byte_count; num_bytes = last_entropy->src2dst_l4_bytes; |