libwifi_get_epoch returns wrong timestamp #23
Description
If I am not wrong, there is an error in the formula used by libwifi_get_epoch() in src/libwifi/core/misc/epoch.c
It shoould be instead
spec.tv_sec * 1000 + spec.tv_nsec / 1000000
to return value in milliseconds.
Because the actual formula mixes milliseconds in the first half, and microsecond in the second half.
The result is that the timestamp returned is erratic, and when coorect, jumps several minutes in the future, and back to present and so on.
You can check that by using the patch below:
--- utils/src/test_generation.c 2023-07-22 05:07:29.000000000 +0200
+++ utils/src/test_generation.c.new 2024-11-02 00:30:03.757922709 +0100
@@ -12,6 +12,8 @@
#include <string.h>
#include <sys/time.h>
#include <unistd.h>
+#include <math.h>
+#include <time.h>
#include "helpers.h"
@@ -168,6 +170,11 @@
printf("\tSource: " MACSTR "\n", MAC2STR(txmac));
printf("\tDestination: " MACSTR "\n", MAC2STR(bcast));
+ time_t t = floor(beacon.fixed_parameters.timestamp/1000);
+ struct tm *tm = localtime(&t);
+ char buffer[20];
+ strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", tm);
+ printf("\tTimeStamp (localtime): %s\n", buffer);
libwifi_dump_beacon(&beacon, buf, buf_sz);
inject_frame(buf, buf_sz);and run ./test_generation --file beacon.pcap --beacon