ui/tap-iax2-analysis.c

   1 /* tap-iax2-analysis.c
   2  * IAX2 analysis addition for Wireshark
   3  *
   4  * based on rtp_analysis.c
   5  * Copyright 2003, Alcatel Business Systems
   6  * By Lars Ruoff <lars.ruoff@gmx.net>
   7  *
   8  * based on tap_rtp.c
   9  * Copyright 2003, Iskratel, Ltd, Kranj
  10  * By Miha Jemec <m.jemec@iskratel.si>
  11  *
  12  * Wireshark - Network traffic analyzer
  13  * By Gerald Combs <gerald@wireshark.org>
  14  * Copyright 1998 Gerald Combs
  15  *
  16  * SPDX-License-Identifier: GPL-2.0-or-later
  17  */
  18
  19 #include "config.h"
  20
  21 #include <math.h>
  22
  23 #include <glib.h>
  24
  25 #include <epan/dissectors/packet-iax2.h>
  26
  27 #include "tap-iax2-analysis.h"
  28
  29 /****************************************************************************/
  30 /* This comes from tap-rtp-common.c */
  31 /****************************************************************************/
  32
  33 void
  34 iax2_packet_analyse(tap_iax2_stat_t *statinfo,
  35         packet_info *pinfo,
  36         const struct _iax2_info_t *iax2info)
  37 {
  38     double current_time;
  39     double current_jitter;
  40     double current_diff;
  41
  42     statinfo->flags = 0;
  43     /* check payload type */
  44     if (iax2info->ftype == AST_FRAME_VOICE) {
  45         if (iax2info->csub != statinfo->pt) {
  46             statinfo->flags |= STAT_FLAG_PT_CHANGE;
  47         }
  48         statinfo->pt = iax2info->csub;
  49     }
  50
  51     /* store the current time and calculate the current jitter */
  52     current_time = nstime_to_sec(&pinfo->rel_ts);
  53     current_diff = fabs (current_time - statinfo->time - (((double)iax2info->timestamp - (double)statinfo->timestamp)/1000));
  54     current_jitter = statinfo->jitter + ( current_diff - statinfo->jitter)/16;
  55     statinfo->delta = current_time - (statinfo->time);
  56     statinfo->jitter = current_jitter;
  57     statinfo->diff = current_diff;
  58
  59     /* calculate the BW in Kbps adding the IP+IAX2 header to the RTP -> 20bytes(IP)+ 4bytes(Mini) = 24bytes */
  60     statinfo->bw_history[statinfo->bw_index].bytes = iax2info->payload_len + 24;
  61     statinfo->bw_history[statinfo->bw_index].time = current_time;
  62     /* check if there are more than 1sec in the history buffer to calculate BW in bps. If so, remove those for the calculation */
  63     while ((statinfo->bw_history[statinfo->bw_start_index].time+1) < current_time) {
  64         statinfo->total_bytes -= statinfo->bw_history[statinfo->bw_start_index].bytes;
  65         statinfo->bw_start_index++;
  66         if (statinfo->bw_start_index == BUFF_BW) {
  67             statinfo->bw_start_index = 0;
  68         }
  69     };
  70     statinfo->total_bytes += iax2info->payload_len + 24;
  71     statinfo->bandwidth = (double)(statinfo->total_bytes*8)/1000;
  72     statinfo->bw_index++;
  73     if (statinfo->bw_index == BUFF_BW) {
  74         statinfo->bw_index = 0;
  75     }
  76
  77     /*  is this the first packet we got in this direction? */
  78     if (statinfo->first_packet) {
  79         statinfo->start_seq_nr = 0;
  80         statinfo->start_time = current_time;
  81         statinfo->delta = 0;
  82         statinfo->jitter = 0;
  83         statinfo->diff = 0;
  84         statinfo->flags |= STAT_FLAG_FIRST;
  85         statinfo->first_packet = false;
  86     }
  87     /* is it a regular packet? */
  88     if (!(statinfo->flags & STAT_FLAG_FIRST)
  89             && !(statinfo->flags & STAT_FLAG_MARKER)
  90             && !(statinfo->flags & STAT_FLAG_PT_CN)
  91             && !(statinfo->flags & STAT_FLAG_WRONG_TIMESTAMP)
  92             && !(statinfo->flags & STAT_FLAG_FOLLOW_PT_CN)) {
  93         /* include it in maximum delta calculation */
  94         if (statinfo->delta > statinfo->max_delta) {
  95             statinfo->max_delta = statinfo->delta;
  96             statinfo->max_nr = pinfo->num;
  97         }
  98         /* maximum and mean jitter calculation */
  99         if (statinfo->jitter > statinfo->max_jitter) {
 100             statinfo->max_jitter = statinfo->jitter;
 101         }
 102         statinfo->mean_jitter = (statinfo->mean_jitter*statinfo->total_nr + current_jitter) / (statinfo->total_nr+1);
 103     }
 104     /* regular payload change? (CN ignored) */
 105     if (!(statinfo->flags & STAT_FLAG_FIRST)
 106             && !(statinfo->flags & STAT_FLAG_PT_CN)) {
 107         if ((statinfo->pt != statinfo->reg_pt)
 108                 && (statinfo->reg_pt != PT_UNDEFINED)) {
 109             statinfo->flags |= STAT_FLAG_REG_PT_CHANGE;
 110         }
 111     }
 112
 113     /* set regular payload*/
 114     if (!(statinfo->flags & STAT_FLAG_PT_CN)) {
 115         statinfo->reg_pt = statinfo->pt;
 116     }
 117
 118     /* TODO: lost packets / duplicated:  we should infer this from timestamp... */
 119     statinfo->time = current_time;
 120     statinfo->timestamp = iax2info->timestamp; /* millisecs */
 121     statinfo->stop_seq_nr = 0;
 122     statinfo->total_nr++;
 123
 124     return;
 125 }