r1663 - trunk/batctl - commits - lists.open-mesh.org

21 May 2010

Author: marek
Date: 2010-05-21 06:17:54 +0200 (Fri, 21 May 2010)
New Revision: 1663
Modified:
   trunk/batctl/Makefile
   trunk/batctl/ping.c
Log:
batctl: Correct mdev calculation in ping subcommand
Fixes the calculation of the mean absolute deviation (mdev)
of the roundtrip times. mdev was previously calculated by
computing the difference of maximum and minimum round trip times.
The calculation is now done using the same formula as in the iputils
ping program.
Signed-off-by: Daniel Seither post@tiwoc.de
Acked-by: Sven Eckelmann sven.eckelmann@gmx.de
Modified: trunk/batctl/Makefile
===================================================================

--- trunk/batctl/Makefile	2010-05-21 04:17:53 UTC (rev 1662)
+++ trunk/batctl/Makefile	2010-05-21 04:17:54 UTC (rev 1663)
@@ -28,7 +28,7 @@
 CC = gcc
 CFLAGS += -pedantic -Wall -W -g3 -std=gnu99 -Os -fno-strict-aliasing
 EXTRA_CFLAGS = -DREVISION_VERSION=$(REVISION_VERSION)
-LDFLAGS +=
+LDFLAGS += -lm
SBINDIR = $(INSTALL_PREFIX)/usr/sbin
Modified: trunk/batctl/ping.c
===================================================================
--- trunk/batctl/ping.c	2010-05-21 04:17:53 UTC (rev 1662)
+++ trunk/batctl/ping.c	2010-05-21 04:17:54 UTC (rev 1663)
@@ -29,6 +29,7 @@
 #include <signal.h>
 #include <fcntl.h>
 #include <string.h>
+#include <math.h>
#include "main.h"
 #include "ping.h"
@@ -76,7 +77,7 @@
    unsigned int seq_counter = 0, packets_out = 0, packets_in = 0, packets_loss;
    char *dst_string, *mac_string, *rr_string;
    double time_delta;
-	float min = 0.0, max = 0.0, avg = 0.0;
+	float min = 0.0, max = 0.0, avg = 0.0, mdev = 0.0;
    uint8_t last_rr_cur = 0, last_rr[BAT_RR_LEN][ETH_ALEN];
    size_t packet_len;
@@ -260,6 +261,7 @@
    		if (time_delta > max)
    			max = time_delta;
    		avg += time_delta;
+			mdev += time_delta * time_delta;
    		packets_in++;
    		break;
    	case DESTINATION_UNREACHABLE:
@@ -289,11 +291,24 @@
    else
    	packets_loss = ((packets_out - packets_in) * 100) / packets_out;
+	if (packets_in) {
+		avg /= packets_in;
+		mdev /= packets_in;
+		mdev = mdev - avg * avg;
+		if (mdev > 0.0)
+			mdev = sqrt(mdev);
+		else
+			mdev = 0.0;
+	} else {
+		avg = 0.0;
+		mdev = 0.0;
+	}
+
    printf("--- %s ping statistics ---\n", dst_string);
    printf("%u packets transmitted, %u received, %u%% packet loss\n",
    	packets_out, packets_in, packets_loss);
    printf("rtt min/avg/max/mdev = %.3f/%.3f/%.3f/%.3f ms\n",
-		min, (packets_in ? (avg / packets_in) : 0.000), max, (max - min));
+		min, avg, max, mdev);
ret = EXIT_SUCCESS;

    