nexmon – Rev 1
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/* tap-icmpv6stat.c
* icmpv6stat 2011 Christopher Maynard
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* This module provides icmpv6 echo request/reply SRT statistics to tshark.
* It is only used by tshark and not wireshark
*
* It was based on tap-icmptat.c, which itself was based on tap-rpcstat.c and
* doc/README.tapping.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <glib.h>
#include <epan/packet_info.h>
#include <epan/tap.h>
#include <epan/stat_tap_ui.h>
#include <epan/dissectors/packet-icmp.h>
void register_tap_listener_icmpv6stat(void);
/* used to keep track of the ICMPv6 statistics */
typedef struct _icmpv6stat_t {
char *filter;
GSList *rt_list;
guint num_rqsts;
guint num_resps;
guint min_frame;
guint max_frame;
double min_msecs;
double max_msecs;
double tot_msecs;
} icmpv6stat_t;
/* This callback is never used by tshark but it is here for completeness. When
* registering below, we could just have left this function as NULL.
*
* When used by wireshark, this function will be called whenever we would need
* to reset all state, such as when wireshark opens a new file, when it starts
* a new capture, when it rescans the packetlist after some prefs have changed,
* etc.
*
* So if your application has some state it needs to clean up in those
* situations, here is a good place to put that code.
*/
static void
icmpv6stat_reset(void *tapdata)
{
icmpv6stat_t *icmpv6stat = (icmpv6stat_t *)tapdata;
g_slist_free(icmpv6stat->rt_list);
memset(icmpv6stat, 0, sizeof(icmpv6stat_t));
icmpv6stat->min_msecs = 1.0 * G_MAXUINT;
}
static gint compare_doubles(gconstpointer a, gconstpointer b)
{
double ad, bd;
ad = *(const double *)a;
bd = *(const double *)b;
if (ad < bd)
return -1;
if (ad > bd)
return 1;
return 0;
}
/* This callback is invoked whenever the tap system has seen a packet we might
* be interested in. The function is to be used to only update internal state
* information in the *tapdata structure, and if there were state changes which
* requires the window to be redrawn, return 1 and (*draw) will be called
* sometime later.
*
* This function should be as lightweight as possible since it executes
* together with the normal wireshark dissectors. Try to push as much
* processing as possible into (*draw) instead since that function executes
* asynchronously and does not affect the main thread's performance.
*
* If it is possible, try to do all "filtering" explicitly since you will get
* MUCH better performance than applying a similar display-filter in the
* register call.
*
* The third parameter is tap dependent. Since we register this one to the
* "icmpv6" tap, the third parameter type is icmp_transaction_t.
*
* function returns :
* FALSE: no updates, no need to call (*draw) later
* TRUE: state has changed, call (*draw) sometime later
*/
static gboolean
icmpv6stat_packet(void *tapdata, packet_info *pinfo _U_, epan_dissect_t *edt _U_, const void *data)
{
icmpv6stat_t *icmpv6stat = (icmpv6stat_t *)tapdata;
const icmp_transaction_t *trans = (const icmp_transaction_t *)data;
double resp_time, *rt;
if (trans == NULL)
return FALSE;
if (trans->resp_frame) {
resp_time = nstime_to_msec(&trans->resp_time);
rt = g_new(double, 1);
if (rt == NULL)
return FALSE;
*rt = resp_time;
icmpv6stat->rt_list = g_slist_prepend(icmpv6stat->rt_list, rt);
icmpv6stat->num_resps++;
if (icmpv6stat->min_msecs > resp_time) {
icmpv6stat->min_frame = trans->resp_frame;
icmpv6stat->min_msecs = resp_time;
}
if (icmpv6stat->max_msecs < resp_time) {
icmpv6stat->max_frame = trans->resp_frame;
icmpv6stat->max_msecs = resp_time;
}
icmpv6stat->tot_msecs += resp_time;
} else if (trans->rqst_frame)
icmpv6stat->num_rqsts++;
else
return FALSE;
return TRUE;
}
/*
* Compute the mean, median and standard deviation.
*/
static void compute_stats(icmpv6stat_t *icmpv6stat, double *mean, double *med, double *sdev)
{
GSList *slist;
double diff;
double sq_diff_sum = 0.0;
icmpv6stat->rt_list = g_slist_sort(icmpv6stat->rt_list, compare_doubles);
slist = icmpv6stat->rt_list;
if (icmpv6stat->num_resps == 0 || slist == NULL) {
*mean = 0.0;
*med = 0.0;
*sdev = 0.0;
return;
}
/* (arithmetic) mean */
*mean = icmpv6stat->tot_msecs / icmpv6stat->num_resps;
/* median: If we have an odd number of elements in our list, then the
* median is simply the middle element, otherwise the median is computed by
* averaging the 2 elements on either side of the mid-point. */
if (icmpv6stat->num_resps & 1)
*med = *(double *)g_slist_nth_data(slist, icmpv6stat->num_resps / 2);
else {
*med =
(*(double *)g_slist_nth_data(slist, (icmpv6stat->num_resps - 1) / 2) +
*(double *)g_slist_nth_data(slist, icmpv6stat->num_resps / 2)) / 2;
}
/* (sample) standard deviation */
for ( ; slist; slist = g_slist_next(slist)) {
diff = *(double *)slist->data - *mean;
sq_diff_sum += diff * diff;
}
if (icmpv6stat->num_resps > 1)
*sdev = sqrt(sq_diff_sum / (icmpv6stat->num_resps - 1));
else
*sdev = 0.0;
}
/* This callback is used when tshark wants us to draw/update our data to the
* output device. Since this is tshark, the only output is stdout.
* TShark will only call this callback once, which is when tshark has finished
* reading all packets and exits.
* If used with wireshark this may be called any time, perhaps once every 3
* seconds or so.
* This function may even be called in parallel with (*reset) or (*draw), so
* make sure there are no races. The data in the icmpv6stat_t can thus change
* beneath us. Beware!
*
* How best to display the data? For now, following other tap statistics
* output, but here are a few other alternatives we might choose from:
*
* -> Windows ping output:
* Ping statistics for <IP>:
* Packets: Sent = <S>, Received = <R>, Lost = <L> (<LP>% loss),
* Approximate round trip times in milli-seconds:
* Minimum = <m>ms, Maximum = <M>ms, Average = <A>ms
*
* -> Cygwin ping output:
* ----<HOST> PING Statistics----
* <S> packets transmitted, <R> packets received, <LP>% packet loss
* round-trip (ms) min/avg/max/med = <m>/<M>/<A>/<D>
*
* -> Linux ping output:
* --- <HOST> ping statistics ---
* <S> packets transmitted, <R> received, <LP>% packet loss, time <T>ms
* rtt min/avg/max/mdev = <m>/<A>/<M>/<D> ms
*/
static void
icmpv6stat_draw(void *tapdata)
{
icmpv6stat_t *icmpv6stat = (icmpv6stat_t *)tapdata;
unsigned int lost;
double mean, sdev, med;
printf("\n");
printf("==========================================================================\n");
printf("ICMPv6 Service Response Time (SRT) Statistics (all times in ms):\n");
printf("Filter: %s\n", icmpv6stat->filter ? icmpv6stat->filter : "<none>");
printf("\nRequests Replies Lost %% Loss\n");
if (icmpv6stat->num_rqsts) {
lost = icmpv6stat->num_rqsts - icmpv6stat->num_resps;
compute_stats(icmpv6stat, &mean, &med, &sdev);
printf("%-10u%-10u%-10u%5.1f%%\n\n",
icmpv6stat->num_rqsts, icmpv6stat->num_resps, lost,
100.0 * lost / icmpv6stat->num_rqsts);
printf("Minimum Maximum Mean Median SDeviation Min Frame Max Frame\n");
printf("%-10.3f%-10.3f%-10.3f%-10.3f%-10.3f %-10u%-10u\n",
icmpv6stat->min_msecs >= G_MAXUINT ? 0.0 : icmpv6stat->min_msecs,
icmpv6stat->max_msecs, mean, med, sdev,
icmpv6stat->min_frame, icmpv6stat->max_frame);
} else {
printf("0 0 0 0.0%%\n\n");
printf("Minimum Maximum Mean Median SDeviation Min Frame Max Frame\n");
printf("0.000 0.000 0.000 0.000 0.000 0 0\n");
}
printf("==========================================================================\n");
}
/* When called, this function will create a new instance of icmpv6stat.
*
* This function is called from tshark when it parses the -z icmpv6, arguments
* and it creates a new instance to store statistics in and registers this new
* instance for the icmpv6 tap.
*/
static void
icmpv6stat_init(const char *opt_arg, void *userdata _U_)
{
icmpv6stat_t *icmpv6stat;
const char *filter = NULL;
GString *error_string;
if (strstr(opt_arg, "icmpv6,srt,"))
filter = opt_arg + strlen("icmpv6,srt,");
icmpv6stat = (icmpv6stat_t *)g_try_malloc(sizeof(icmpv6stat_t));
if (icmpv6stat == NULL) {
fprintf(stderr, "tshark: g_try_malloc() fatal error.\n");
exit(1);
}
memset(icmpv6stat, 0, sizeof(icmpv6stat_t));
icmpv6stat->min_msecs = 1.0 * G_MAXUINT;
if (filter)
icmpv6stat->filter = g_strdup(filter);
/* It is possible to create a filter and attach it to the callbacks. Then the
* callbacks would only be invoked if the filter matched.
*
* Evaluating filters is expensive and if we can avoid it and not use them,
* then we gain performance.
*
* In this case we do the filtering for protocol and version inside the
* callback itself but use whatever filter the user provided.
*/
error_string = register_tap_listener("icmpv6", icmpv6stat, icmpv6stat->filter,
TL_REQUIRES_NOTHING, icmpv6stat_reset, icmpv6stat_packet, icmpv6stat_draw);
if (error_string) {
/* error, we failed to attach to the tap. clean up */
if (icmpv6stat->filter)
g_free(icmpv6stat->filter);
g_free(icmpv6stat);
fprintf(stderr, "tshark: Couldn't register icmpv6,srt tap: %s\n",
error_string->str);
g_string_free(error_string, TRUE);
exit(1);
}
}
static stat_tap_ui icmpv6stat_ui = {
REGISTER_STAT_GROUP_GENERIC,
NULL,
"icmpv6,srt",
icmpv6stat_init,
0,
NULL
};
void
register_tap_listener_icmpv6stat(void)
{
register_stat_tap_ui(&icmpv6stat_ui, NULL);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/