ui/tap-rtp-common.c

   1 /* tap-rtp-common.c
   2  * RTP stream handler functions used by tshark and wireshark
   3  *
   4  * Copyright 2008, Ericsson AB
   5  * By Balint Reczey <balint.reczey@ericsson.com>
   6  *
   7  * most functions are copied from ui/gtk/rtp_stream.c and ui/gtk/rtp_analysis.c
   8  * Copyright 2003, Alcatel Business Systems
   9  * By Lars Ruoff <lars.ruoff@gmx.net>
  10  *
  11  * Wireshark - Network traffic analyzer
  12  * By Gerald Combs <gerald@wireshark.org>
  13  * Copyright 1998 Gerald Combs
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version 2
  18  * of the License, or (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation,  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  28  */
  29
  30 #include "config.h"
  31
  32 #include <glib.h>
  33
  34 #include <math.h>
  35 #include "globals.h"
  36
  37 #include <string.h>
  38 #include <epan/rtp_pt.h>
  39 #include <epan/addr_resolv.h>
  40 #include <epan/proto_data.h>
  41 #include <epan/dissectors/packet-rtp.h>
  42 #include <wsutil/pint.h>
  43 #include "rtp_stream.h"
  44 #include "tap-rtp-common.h"
  45
  46 /* XXX: are changes needed to properly handle situations where
  47         info_all_data_present == FALSE ?
  48         E.G., when captured frames are truncated.
  49  */
  50
  51 /****************************************************************************/
  52 /* Type for storing and writing rtpdump information */
  53 typedef struct st_rtpdump_info {
  54     double rec_time;        /**< milliseconds since start of recording */
  55     guint16 num_samples;   /**< number of bytes in *frame */
  56     const guint8 *samples;                 /**< data bytes */
  57 } rtpdump_info_t;
  58
  59 /****************************************************************************/
  60 /* GCompareFunc style comparison function for _rtp_stream_info */
  61 static gint rtp_stream_info_cmp(gconstpointer aa, gconstpointer bb)
  62 {
  63         const struct _rtp_stream_info* a = (const struct _rtp_stream_info*)aa;
  64         const struct _rtp_stream_info* b = (const struct _rtp_stream_info*)bb;
  65
  66         if (a==b)
  67                 return 0;
  68         if (a==NULL || b==NULL)
  69                 return 1;
  70         if (addresses_equal(&(a->src_addr), &(b->src_addr))
  71                 && (a->src_port == b->src_port)
  72                 && addresses_equal(&(a->dest_addr), &(b->dest_addr))
  73                 && (a->dest_port == b->dest_port)
  74                 && (a->ssrc == b->ssrc))
  75                 return 0;
  76         else
  77                 return 1;
  78 }
  79
  80
  81 /****************************************************************************/
  82 /* when there is a [re]reading of packet's */
  83 void rtpstream_reset(rtpstream_tapinfo_t *tapinfo)
  84 {
  85         GList* list;
  86
  87         if (tapinfo->mode == TAP_ANALYSE) {
  88                 /* free the data items first */
  89                 list = g_list_first(tapinfo->strinfo_list);
  90                 while (list)
  91                 {
  92                         g_free(list->data);
  93                         list = g_list_next(list);
  94                 }
  95                 g_list_free(tapinfo->strinfo_list);
  96                 tapinfo->strinfo_list = NULL;
  97                 tapinfo->nstreams = 0;
  98                 tapinfo->npackets = 0;
  99         }
 100
 101         return;
 102 }
 103
 104 void rtpstream_reset_cb(void *arg)
 105 {
 106         rtpstream_tapinfo_t *ti =(rtpstream_tapinfo_t *)arg;
 107         if (ti->tap_reset) {
 108                 /* Give listeners a chance to cleanup references. */
 109                 ti->tap_reset(ti);
 110         }
 111         rtpstream_reset(ti);
 112 }
 113
 114 /*
 115 * rtpdump file format
 116 *
 117 * The file starts with the tool to be used for playing this file,
 118 * the multicast/unicast receive address and the port.
 119 *
 120 * #!rtpplay1.0 224.2.0.1/3456\n
 121 *
 122 * This is followed by one binary header (RD_hdr_t) and one RD_packet_t
 123 * structure for each received packet.  All fields are in network byte
 124 * order.  We don't need the source IP address since we can do mapping
 125 * based on SSRC.  This saves (a little) space, avoids non-IPv4
 126 * problems and privacy/security concerns. The header is followed by
 127 * the RTP/RTCP header and (optionally) the actual payload.
 128 */
 129
 130 #define RTPFILE_VERSION "1.0"
 131
 132 /*
 133 * Write a header to the current output file.
 134 * The header consists of an identifying string, followed
 135 * by a binary structure.
 136 */
 137 void rtp_write_header(rtp_stream_info_t *strinfo, FILE *file)
 138 {
 139         guint32 start_sec;     /* start of recording (GMT) (seconds) */
 140         guint32 start_usec;    /* start of recording (GMT) (microseconds)*/
 141         guint32 source;        /* network source (multicast address) */
 142         size_t sourcelen;
 143         guint16 port;          /* UDP port */
 144         guint16 padding;       /* 2 padding bytes */
 145         char* addr_str = address_to_display(NULL, &(strinfo->dest_addr));
 146
 147         fprintf(file, "#!rtpplay%s %s/%u\n", RTPFILE_VERSION,
 148                 addr_str,
 149                 strinfo->dest_port);
 150         wmem_free(NULL, addr_str);
 151
 152         start_sec = g_htonl(strinfo->start_fd->abs_ts.secs);
 153         start_usec = g_htonl(strinfo->start_fd->abs_ts.nsecs / 1000000);
 154         /* rtpdump only accepts guint32 as source, will be fake for IPv6 */
 155         memset(&source, 0, sizeof source);
 156         sourcelen = strinfo->src_addr.len;
 157         if (sourcelen > sizeof source)
 158                 sourcelen = sizeof source;
 159         memcpy(&source, strinfo->src_addr.data, sourcelen);
 160         port = g_htons(strinfo->src_port);
 161         padding = 0;
 162
 163         if (fwrite(&start_sec, 4, 1, file) == 0)
 164                 return;
 165         if (fwrite(&start_usec, 4, 1, file) == 0)
 166                 return;
 167         if (fwrite(&source, 4, 1, file) == 0)
 168                 return;
 169         if (fwrite(&port, 2, 1, file) == 0)
 170                 return;
 171         if (fwrite(&padding, 2, 1, file) == 0)
 172                 return;
 173 }
 174
 175 /* utility function for writing a sample to file in rtpdump -F dump format (.rtp)*/
 176 static void rtp_write_sample(rtpdump_info_t* rtpdump_info, FILE* file)
 177 {
 178         guint16 length;    /* length of packet, including this header (may
 179                              be smaller than plen if not whole packet recorded) */
 180         guint16 plen;      /* actual header+payload length for RTP, 0 for RTCP */
 181         guint32 offset;    /* milliseconds since the start of recording */
 182
 183         length = g_htons(rtpdump_info->num_samples + 8);
 184         plen = g_htons(rtpdump_info->num_samples);
 185         offset = g_htonl(rtpdump_info->rec_time);
 186
 187         if (fwrite(&length, 2, 1, file) == 0)
 188                 return;
 189         if (fwrite(&plen, 2, 1, file) == 0)
 190                 return;
 191         if (fwrite(&offset, 4, 1, file) == 0)
 192                 return;
 193         if (fwrite(rtpdump_info->samples, rtpdump_info->num_samples, 1, file) == 0)
 194                 return;
 195 }
 196
 197
 198 /****************************************************************************/
 199 /* whenever a RTP packet is seen by the tap listener */
 200 int rtpstream_packet(void *arg, packet_info *pinfo, epan_dissect_t *edt _U_, const void *arg2)
 201 {
 202         rtpstream_tapinfo_t *tapinfo = (rtpstream_tapinfo_t *)arg;
 203         const struct _rtp_info *rtpinfo = (const struct _rtp_info *)arg2;
 204         rtp_stream_info_t new_stream_info;
 205         rtp_stream_info_t *stream_info = NULL;
 206         GList* list;
 207         rtpdump_info_t rtpdump_info;
 208
 209         struct _rtp_conversation_info *p_conv_data = NULL;
 210
 211         /* gather infos on the stream this packet is part of */
 212         memset(&new_stream_info, 0, sizeof(rtp_stream_info_t));
 213         copy_address(&(new_stream_info.src_addr), &(pinfo->src));
 214         new_stream_info.src_port = pinfo->srcport;
 215         copy_address(&(new_stream_info.dest_addr), &(pinfo->dst));
 216         new_stream_info.dest_port = pinfo->destport;
 217         new_stream_info.ssrc = rtpinfo->info_sync_src;
 218         new_stream_info.payload_type = rtpinfo->info_payload_type;
 219         new_stream_info.payload_type_name = g_strdup(rtpinfo->info_payload_type_str);
 220
 221         if (tapinfo->mode == TAP_ANALYSE) {
 222                 /* check whether we already have a stream with these parameters in the list */
 223                 list = g_list_first(tapinfo->strinfo_list);
 224                 while (list)
 225                 {
 226                         if (rtp_stream_info_cmp(&new_stream_info, (rtp_stream_info_t*)(list->data))==0)
 227                         {
 228                                 stream_info = (rtp_stream_info_t*)(list->data);  /*found!*/
 229                                 break;
 230                         }
 231                         list = g_list_next(list);
 232                 }
 233
 234                 /* not in the list? then create a new entry */
 235                 if (!stream_info) {
 236                         new_stream_info.start_fd = pinfo->fd;
 237                         new_stream_info.start_rel_time = pinfo->rel_ts;
 238
 239                         /* reset RTP stats */
 240                         new_stream_info.rtp_stats.first_packet = TRUE;
 241                         new_stream_info.rtp_stats.reg_pt = PT_UNDEFINED;
 242
 243                         /* Get the Setup frame number who set this RTP stream */
 244                         p_conv_data = (struct _rtp_conversation_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_get_id_by_filter_name("rtp"), 0);
 245                         if (p_conv_data)
 246                                 new_stream_info.setup_frame_number = p_conv_data->frame_number;
 247                         else
 248                                 new_stream_info.setup_frame_number = 0xFFFFFFFF;
 249
 250                         stream_info = g_new(rtp_stream_info_t,1);
 251                         *stream_info = new_stream_info;  /* memberwise copy of struct */
 252                         tapinfo->strinfo_list = g_list_append(tapinfo->strinfo_list, stream_info);
 253                 }
 254
 255                 /* get RTP stats for the packet */
 256                 rtp_packet_analyse(&(stream_info->rtp_stats), pinfo, rtpinfo);
 257                 if (stream_info->rtp_stats.flags & STAT_FLAG_WRONG_TIMESTAMP
 258                                 || stream_info->rtp_stats.flags & STAT_FLAG_WRONG_SEQ)
 259                         stream_info->problem = TRUE;
 260
 261
 262                 /* increment the packets counter for this stream */
 263                 ++(stream_info->packet_count);
 264                 stream_info->stop_rel_time = pinfo->rel_ts;
 265
 266                 /* increment the packets counter of all streams */
 267                 ++(tapinfo->npackets);
 268
 269                 return 1;  /* refresh output */
 270         }
 271         else if (tapinfo->mode == TAP_SAVE) {
 272                 if (rtp_stream_info_cmp(&new_stream_info, tapinfo->filter_stream_fwd)==0) {
 273                         /* XXX - what if rtpinfo->info_all_data_present is
 274                            FALSE, so that we don't *have* all the data? */
 275                         rtpdump_info.rec_time = nstime_to_msec(&pinfo->abs_ts) -
 276                                 nstime_to_msec(&tapinfo->filter_stream_fwd->start_fd->abs_ts);
 277                         rtpdump_info.num_samples = rtpinfo->info_data_len;
 278                         rtpdump_info.samples = rtpinfo->info_data;
 279                         rtp_write_sample(&rtpdump_info, tapinfo->save_file);
 280                 }
 281         }
 282         else if (tapinfo->mode == TAP_MARK && tapinfo->tap_mark_packet) {
 283                 if (rtp_stream_info_cmp(&new_stream_info, tapinfo->filter_stream_fwd)==0
 284                     || rtp_stream_info_cmp(&new_stream_info, tapinfo->filter_stream_rev)==0)
 285                 {
 286                         tapinfo->tap_mark_packet(tapinfo, pinfo->fd);
 287                 }
 288         }
 289         return 0;
 290 }
 291
 292
 293 typedef struct _key_value {
 294   guint32  key;
 295   guint32  value;
 296 } key_value;
 297
 298
 299 /* RTP sampling clock rates for fixed payload types as defined in
 300  http://www.iana.org/assignments/rtp-parameters */
 301 static const key_value clock_map[] = {
 302         {PT_PCMU,       8000},
 303         {PT_1016,       8000},
 304         {PT_G721,       8000},
 305         {PT_GSM,        8000},
 306         {PT_G723,       8000},
 307         {PT_DVI4_8000,  8000},
 308         {PT_DVI4_16000, 16000},
 309         {PT_LPC,        8000},
 310         {PT_PCMA,       8000},
 311         {PT_G722,       8000},
 312         {PT_L16_STEREO, 44100},
 313         {PT_L16_MONO,   44100},
 314         {PT_QCELP,      8000},
 315         {PT_CN,         8000},
 316         {PT_MPA,        90000},
 317         {PT_G728,       8000},
 318         {PT_G728,       8000},
 319         {PT_DVI4_11025, 11025},
 320         {PT_DVI4_22050, 22050},
 321         {PT_G729,       8000},
 322         {PT_CN_OLD,     8000},
 323         {PT_CELB,       90000},
 324         {PT_JPEG,       90000},
 325         {PT_NV,         90000},
 326         {PT_H261,       90000},
 327         {PT_MPV,        90000},
 328         {PT_MP2T,       90000},
 329         {PT_H263,       90000},
 330 };
 331
 332 #define NUM_CLOCK_VALUES        (sizeof clock_map / sizeof clock_map[0])
 333
 334 static guint32
 335 get_clock_rate(guint32 key)
 336 {
 337         size_t i;
 338
 339         for (i = 0; i < NUM_CLOCK_VALUES; i++) {
 340                 if (clock_map[i].key == key)
 341                         return clock_map[i].value;
 342         }
 343         return 0;
 344 }
 345
 346 typedef struct _mimetype_and_clock {
 347         const gchar   *pt_mime_name_str;
 348         guint32 value;
 349 } mimetype_and_clock;
 350 /*      RTP sampling clock rates for
 351         "In addition to the RTP payload formats (encodings) listed in the RTP
 352         Payload Types table, there are additional payload formats that do not
 353         have static RTP payload types assigned but instead use dynamic payload
 354         type number assignment.  Each payload format is named by a registered
 355         MIME subtype"
 356         http://www.iana.org/assignments/rtp-parameters.
 357
 358         NOTE: Please keep the mimetypes in case insensitive alphabetical order.
 359 */
 360 static const mimetype_and_clock mimetype_and_clock_map[] = {
 361         {"AMR",         8000},                  /* [RFC4867][RFC3267] */
 362         {"AMR-WB",      16000},                 /* [RFC4867][RFC3267] */
 363         {"BMPEG",       90000},                 /* [RFC2343],[RFC3555] */
 364         {"BT656",       90000},                 /* [RFC2431],[RFC3555] */
 365         {"DV",          90000},                 /* [RFC3189] */
 366         {"EVRC",        8000},                  /* [RFC3558] */
 367         {"EVRC0",       8000},                  /* [RFC4788] */
 368         {"EVRC1",       8000},                  /* [RFC4788] */
 369         {"EVRCB",       8000},                  /* [RFC4788] */
 370         {"EVRCB0",      8000},                  /* [RFC4788] */
 371         {"EVRCB1",      8000},                  /* [RFC4788] */
 372         {"EVRCWB",      16000},                 /* [RFC5188] */
 373         {"EVRCWB0",     16000},                 /* [RFC5188] */
 374         {"EVRCWB1",     16000},                 /* [RFC5188] */
 375         {"EVS",         16000},                 /* [3GPP TS 26.445] */
 376         {"G7221",       16000},                 /* [RFC3047] */
 377         {"G726-16",     8000},                  /* [RFC3551][RFC4856] */
 378         {"G726-24",     8000},                  /* [RFC3551][RFC4856] */
 379         {"G726-32",     8000},                  /* [RFC3551][RFC4856] */
 380         {"G726-40",     8000},                  /* [RFC3551][RFC4856] */
 381         {"G729D",       8000},                  /* [RFC3551][RFC4856] */
 382         {"G729E",       8000},                  /* [RFC3551][RFC4856] */
 383         {"GSM-EFR",     8000},                  /* [RFC3551] */
 384         {"H263-1998",   90000},                 /* [RFC2429],[RFC3555] */
 385         {"H263-2000",   90000},                 /* [RFC2429],[RFC3555] */
 386         {"H264",        90000},                 /* [RFC3984] */
 387         {"MP1S",        90000},                 /* [RFC2250],[RFC3555] */
 388         {"MP2P",        90000},                 /* [RFC2250],[RFC3555] */
 389         {"MP4V-ES",     90000},                 /* [RFC3016] */
 390         {"mpa-robust",  90000},                 /* [RFC3119] */
 391         {"pointer",     90000},                 /* [RFC2862] */
 392         {"raw",         90000},                 /* [RFC4175] */
 393         {"red",         1000},                  /* [RFC4102] */
 394         {"SMV",         8000},                  /* [RFC3558] */
 395         {"SMV0",        8000},                  /* [RFC3558] */
 396         {"t140",        1000},                  /* [RFC4103] */
 397         {"telephone-event", 8000},              /* [RFC4733] */
 398 };
 399
 400 #define NUM_DYN_CLOCK_VALUES    (sizeof mimetype_and_clock_map / sizeof mimetype_and_clock_map[0])
 401
 402 static guint32
 403 get_dyn_pt_clock_rate(const gchar *payload_type_str)
 404 {
 405         int i;
 406
 407         /* Search for matching mimetype in reverse order to avoid false matches
 408          * when pt_mime_name_str is the prefix of payload_type_str */
 409         for (i = NUM_DYN_CLOCK_VALUES - 1; i > -1 ; i--) {
 410                 if (g_ascii_strncasecmp(mimetype_and_clock_map[i].pt_mime_name_str,payload_type_str,(strlen(mimetype_and_clock_map[i].pt_mime_name_str))) == 0)
 411                         return mimetype_and_clock_map[i].value;
 412         }
 413
 414         return 0;
 415 }
 416
 417 /****************************************************************************/
 418 void
 419 rtp_packet_analyse(tap_rtp_stat_t *statinfo,
 420                        packet_info *pinfo,
 421                        const struct _rtp_info *rtpinfo)
 422 {
 423         double current_time;
 424         double current_jitter;
 425         double current_diff = 0;
 426         double nominaltime;
 427         double arrivaltime;             /* Time relative to start_time */
 428         double expected_time;
 429         double absskew;
 430         guint32 clock_rate;
 431
 432         /* Store the current time */
 433         current_time = nstime_to_msec(&pinfo->rel_ts);
 434
 435         /*  Is this the first packet we got in this direction? */
 436         if (statinfo->first_packet) {
 437                 /* Save the MAC address of the first RTP frame */
 438                 if( pinfo->dl_src.type == AT_ETHER){
 439                         copy_address(&(statinfo->first_packet_mac_addr), &(pinfo->dl_src));
 440                 }
 441                 statinfo->start_seq_nr = rtpinfo->info_seq_num;
 442                 statinfo->stop_seq_nr = rtpinfo->info_seq_num;
 443                 statinfo->seq_num = rtpinfo->info_seq_num;
 444                 statinfo->start_time = current_time;
 445                 statinfo->timestamp = rtpinfo->info_timestamp;
 446                 statinfo->first_timestamp = rtpinfo->info_timestamp;
 447                 statinfo->time = current_time;
 448                 statinfo->lastnominaltime = 0;
 449                 statinfo->pt = rtpinfo->info_payload_type;
 450                 statinfo->reg_pt = rtpinfo->info_payload_type;
 451                 if (pinfo->net_src.type == AT_IPv6) {
 452                         statinfo->bw_history[statinfo->bw_index].bytes = rtpinfo->info_data_len + 48;
 453                 } else {
 454                         statinfo->bw_history[statinfo->bw_index].bytes = rtpinfo->info_data_len + 28;
 455                 }
 456                 statinfo->bw_history[statinfo->bw_index].time = current_time;
 457                 statinfo->bw_index++;
 458                 if (pinfo->net_src.type == AT_IPv6) {
 459                         statinfo->total_bytes += rtpinfo->info_data_len + 48;
 460                 } else {
 461                         statinfo->total_bytes += rtpinfo->info_data_len + 28;
 462                 }
 463                 statinfo->bandwidth = (double)(statinfo->total_bytes*8)/1000;
 464                 /* Not needed ? initialised to zero? */
 465                 statinfo->delta = 0;
 466                 statinfo->jitter = 0;
 467                 statinfo->diff = 0;
 468
 469                 statinfo->total_nr++;
 470                 statinfo->flags |= STAT_FLAG_FIRST;
 471                 if (rtpinfo->info_marker_set) {
 472                         statinfo->flags |= STAT_FLAG_MARKER;
 473                 }
 474                 statinfo->first_packet_num = pinfo->num;
 475                 statinfo->first_packet = FALSE;
 476                 return;
 477         }
 478
 479         /* Reset flags */
 480         statinfo->flags = 0;
 481 #if 0
 482         /*According to bug https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=11478
 483          * this code causes problems. A better solution is needed if there is need for the functionality */
 484         /* Try to detect duplicated packets due to mirroring/span ports by comparing src MAC addresses.
 485          * Chek for duplicates (src mac differs from first_packet_mac_addr) */
 486          */
 487         if( pinfo->dl_src.type == AT_ETHER){
 488                 if(!addresses_equal(&(statinfo->first_packet_mac_addr), &(pinfo->dl_src))){
 489                         statinfo->flags |= STAT_FLAG_DUP_PKT;
 490                         statinfo->delta = current_time-(statinfo->time);
 491                         return;
 492                 }
 493         }
 494 #endif
 495         /* When calculating expected rtp packets the seq number can wrap around
 496          * so we have to count the number of cycles
 497          * Variable cycles counts the wraps around in forwarding connection and
 498          * under is flag that indicates where we are
 499          *
 500          * XXX How to determine number of cycles with all possible lost, late
 501          * and duplicated packets without any doubt? It seems to me, that
 502          * because of all possible combination of late, duplicated or lost
 503          * packets, this can only be more or less good approximation
 504          *
 505          * There are some combinations (rare but theoretically possible),
 506          * where below code won't work correctly - statistic may be wrong then.
 507          */
 508
 509         /* So if the current sequence number is less than the start one
 510          * we assume, that there is another cycle running
 511          */
 512         if ((rtpinfo->info_seq_num < statinfo->start_seq_nr) && (statinfo->under == FALSE)){
 513                 statinfo->cycles++;
 514                 statinfo->under = TRUE;
 515         }
 516         /* what if the start seq nr was 0? Then the above condition will never
 517          * be true, so we add another condition. XXX The problem would arise
 518          * if one of the packets with seq nr 0 or 65535 would be lost or late
 519          */
 520         else if ((rtpinfo->info_seq_num == 0) && (statinfo->stop_seq_nr == 65535) &&
 521                 (statinfo->under == FALSE)){
 522                 statinfo->cycles++;
 523                 statinfo->under = TRUE;
 524         }
 525         /* the whole round is over, so reset the flag */
 526         else if ((rtpinfo->info_seq_num > statinfo->start_seq_nr) && (statinfo->under != FALSE)) {
 527                 statinfo->under = FALSE;
 528         }
 529
 530         /* Since it is difficult to count lost, duplicate or late packets separately,
 531          * we would like to know at least how many times the sequence number was not ok
 532          */
 533
 534         /* If the current seq number equals the last one or if we are here for
 535          * the first time, then it is ok, we just store the current one as the last one
 536          */
 537         if ( (statinfo->seq_num+1 == rtpinfo->info_seq_num) || (statinfo->flags & STAT_FLAG_FIRST) )
 538                 statinfo->seq_num = rtpinfo->info_seq_num;
 539         /* If the first one is 65535 we wrap */
 540         else if ( (statinfo->seq_num == 65535) && (rtpinfo->info_seq_num == 0) )
 541                 statinfo->seq_num = rtpinfo->info_seq_num;
 542         /* Lost packets. If the prev seq is enormously larger than the cur seq
 543          * we assume that instead of being massively late we lost the packet(s)
 544          * that would have indicated the sequence number wrapping. An imprecise
 545          * heuristic at best, but it seems to work well enough.
 546          * https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=5958 */
 547         else if (statinfo->seq_num+1 < rtpinfo->info_seq_num || statinfo->seq_num - rtpinfo->info_seq_num > 0xFF00) {
 548                 statinfo->seq_num = rtpinfo->info_seq_num;
 549                 statinfo->sequence++;
 550                 statinfo->flags |= STAT_FLAG_WRONG_SEQ;
 551         }
 552         /* Late or duplicated */
 553         else if (statinfo->seq_num+1 > rtpinfo->info_seq_num) {
 554                 statinfo->sequence++;
 555                 statinfo->flags |= STAT_FLAG_WRONG_SEQ;
 556         }
 557
 558         /* Check payload type */
 559         if (rtpinfo->info_payload_type == PT_CN
 560                 || rtpinfo->info_payload_type == PT_CN_OLD)
 561                 statinfo->flags |= STAT_FLAG_PT_CN;
 562         if (statinfo->pt == PT_CN
 563                 || statinfo->pt == PT_CN_OLD)
 564                 statinfo->flags |= STAT_FLAG_FOLLOW_PT_CN;
 565         if (rtpinfo->info_payload_type != statinfo->pt)
 566                 statinfo->flags |= STAT_FLAG_PT_CHANGE;
 567         statinfo->pt = rtpinfo->info_payload_type;
 568
 569         /*
 570          * Return for unknown payload types
 571          * Ignore jitter calculation for clockrate = 0
 572          */
 573         if (statinfo->pt < 96 ){
 574                 clock_rate = get_clock_rate(statinfo->pt);
 575         }else{ /* Dynamic PT */
 576                 if ( rtpinfo->info_payload_type_str != NULL ){
 577                         /* Is it a "telephone-event" ?
 578                          * Timestamp is not increased for telepone-event packets impacting
 579                          * calculation of Jitter Skew and clock drift.
 580                          * see 2.2.1 of RFC 4733
 581                          */
 582                         if (g_ascii_strncasecmp("telephone-event",rtpinfo->info_payload_type_str,(strlen("telephone-event")))==0){
 583                                 clock_rate = 0;
 584                                 statinfo->flags |= STAT_FLAG_PT_T_EVENT;
 585                         }else{
 586                                 if(rtpinfo->info_payload_rate !=0){
 587                                         clock_rate = rtpinfo->info_payload_rate;
 588                                 }else{
 589                                         clock_rate = get_dyn_pt_clock_rate(rtpinfo->info_payload_type_str);
 590                                 }
 591                         }
 592                 }else{
 593                         clock_rate = 0;
 594                 }
 595         }
 596
 597                 /* Handle wraparound ? */
 598         arrivaltime = current_time - statinfo->start_time;
 599
 600         nominaltime = (double)(guint32_wraparound_diff(rtpinfo->info_timestamp, statinfo->first_timestamp));
 601
 602         /* Can only analyze defined sampling rates */
 603         if (clock_rate != 0) {
 604                 statinfo->clock_rate = clock_rate;
 605                 /* Convert from sampling clock to ms */
 606                 nominaltime = nominaltime /(clock_rate/1000);
 607
 608                 /* Calculate the current jitter(in ms) */
 609                 if (!statinfo->first_packet) {
 610                         expected_time = statinfo->time + (nominaltime - statinfo->lastnominaltime);
 611                         current_diff = fabs(current_time - expected_time);
 612                         current_jitter = (15 * statinfo->jitter + current_diff) / 16;
 613
 614                         statinfo->delta = current_time-(statinfo->time);
 615                         statinfo->jitter = current_jitter;
 616                         statinfo->diff = current_diff;
 617                 }
 618                 statinfo->lastnominaltime = nominaltime;
 619                 /* Calculate skew, i.e. absolute jitter that also catches clock drift
 620                  * Skew is positive if TS (nominal) is too fast
 621                  */
 622                 statinfo->skew    = nominaltime - arrivaltime;
 623                 absskew = fabs(statinfo->skew);
 624                 if(absskew > fabs(statinfo->max_skew)){
 625                         statinfo->max_skew = statinfo->skew;
 626                 }
 627                 /* Gather data for calculation of average, minimum and maximum framerate based on timestamp */
 628 #if 0
 629                 if (numPackets > 0 && (!hardPayloadType || !alternatePayloadType)) {
 630                         /* Skip first packet and possibly alternate payload type packets */
 631                         double dt;
 632                         dt     = nominaltime - statinfo->lastnominaltime;
 633                         sumdt += 1.0 * dt;
 634                         numdt += (dt != 0 ? 1 : 0);
 635                         mindt  = (dt < mindt ? dt : mindt);
 636                         maxdt  = (dt > maxdt ? dt : maxdt);
 637                 }
 638 #endif
 639                 /* Gather data for calculation of skew least square */
 640                 statinfo->sumt   += 1.0 * current_time;
 641                 statinfo->sumTS  += 1.0 * nominaltime;
 642                 statinfo->sumt2  += 1.0 * current_time * current_time;
 643                 statinfo->sumtTS += 1.0 * current_time * nominaltime;
 644         }
 645
 646         /* Calculate the BW in Kbps adding the IP+UDP header to the RTP -> 20bytes(IP) + 8bytes(UDP) */
 647         if (pinfo->net_src.type == AT_IPv6) {
 648                 statinfo->bw_history[statinfo->bw_index].bytes = rtpinfo->info_data_len + 48;
 649         } else {
 650                 statinfo->bw_history[statinfo->bw_index].bytes = rtpinfo->info_data_len + 28;
 651         }
 652         statinfo->bw_history[statinfo->bw_index].time = current_time;
 653
 654         /* Check if there are more than 1sec in the history buffer to calculate BW in bps. If so, remove those for the calculation */
 655         while ((statinfo->bw_history[statinfo->bw_start_index].time+1000/* ms */)<current_time){
 656                 statinfo->total_bytes -= statinfo->bw_history[statinfo->bw_start_index].bytes;
 657                 statinfo->bw_start_index++;
 658                 if (statinfo->bw_start_index == BUFF_BW) statinfo->bw_start_index=0;
 659         };
 660         /* IP hdr + UDP + RTP */
 661         if (pinfo->net_src.type == AT_IPv6){
 662                 statinfo->total_bytes += rtpinfo->info_data_len + 48;
 663         }else{
 664                 statinfo->total_bytes += rtpinfo->info_data_len + 28;
 665         }
 666         statinfo->bandwidth = (double)(statinfo->total_bytes*8)/1000;
 667         statinfo->bw_index++;
 668         if (statinfo->bw_index == BUFF_BW) statinfo->bw_index = 0;
 669
 670
 671         /* Used by GTK code only */
 672         statinfo->delta_timestamp = guint32_wraparound_diff(rtpinfo->info_timestamp, statinfo->timestamp);
 673
 674         /* Is it a packet with the mark bit set? */
 675         if (rtpinfo->info_marker_set) {
 676                 statinfo->flags |= STAT_FLAG_MARKER;
 677         }
 678
 679         /* Difference can be negative. We don't expect difference bigger than 31 bits. Difference don't care about wrap around. */
 680         gint32 tsdelta=rtpinfo->info_timestamp - statinfo->timestamp;
 681         if (tsdelta < 0) {
 682                 statinfo->flags |= STAT_FLAG_WRONG_TIMESTAMP;
 683         }
 684         /* Is it a regular packet? */
 685         if (!(statinfo->flags & STAT_FLAG_FIRST)
 686                 && !(statinfo->flags & STAT_FLAG_MARKER)
 687                 && !(statinfo->flags & STAT_FLAG_PT_CN)
 688                 && !(statinfo->flags & STAT_FLAG_WRONG_TIMESTAMP)
 689                 && !(statinfo->flags & STAT_FLAG_FOLLOW_PT_CN)) {
 690                 /* Include it in maximum delta calculation */
 691                 if (statinfo->delta > statinfo->max_delta) {
 692                         statinfo->max_delta = statinfo->delta;
 693                         statinfo->max_nr = pinfo->num;
 694                 }
 695                 if (clock_rate != 0) {
 696                         /* Maximum and mean jitter calculation */
 697                         if (statinfo->jitter > statinfo->max_jitter) {
 698                                 statinfo->max_jitter = statinfo->jitter;
 699                         }
 700                         statinfo->mean_jitter = (statinfo->mean_jitter*statinfo->total_nr + current_diff) / (statinfo->total_nr+1);
 701                 }
 702         }
 703         /* Regular payload change? (CN ignored) */
 704         if (!(statinfo->flags & STAT_FLAG_FIRST)
 705                 && !(statinfo->flags & STAT_FLAG_PT_CN)) {
 706                 if ((statinfo->pt != statinfo->reg_pt)
 707                         && (statinfo->reg_pt != PT_UNDEFINED)) {
 708                         statinfo->flags |= STAT_FLAG_REG_PT_CHANGE;
 709                 }
 710         }
 711
 712         /* Set regular payload*/
 713         if (!(statinfo->flags & STAT_FLAG_PT_CN)) {
 714                 statinfo->reg_pt = statinfo->pt;
 715         }
 716
 717         statinfo->time = current_time;
 718         statinfo->timestamp = rtpinfo->info_timestamp;
 719         statinfo->stop_seq_nr = rtpinfo->info_seq_num;
 720         statinfo->total_nr++;
 721         statinfo->last_payload_len = rtpinfo->info_payload_len - rtpinfo->info_padding_count;
 722
 723         return;
 724 }
 725
 726 /*
 727  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 728  *
 729  * Local variables:
 730  * c-basic-offset: 8
 731  * tab-width: 8
 732  * indent-tabs-mode: t
 733  * End:
 734  *
 735  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 736  * :indentSize=8:tabSize=8:noTabs=false:
 737  */