src/rtp.c

   1 /*
   2  * Mausezahn - A fast versatile traffic generator
   3  * Copyright (C) 2008 Herbert Haas
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License version 2 as published by the
   7  * Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
  12  * details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, see http://www.gnu.org/licenses/gpl-2.0.html
  16  *
  17 */
  18
  19
  20
  21 #include "mz.h"
  22 #include "cli.h"
  23 #include "mops.h"
  24
  25 #define MZ_RTP_HELP \
  26                 "| RTP type: Send Real Time Protocol packets.\n" \
  27                 "|\n" \
  28                 "| This mode is solely intended to conduct delay, drop, and jitter measurements in\n" \
  29                 "| Voice (Video) over IP networks. You will typically initiate another Mausezahn\n" \
  30                 "| instance on the destination host, which will perform the measurements or even\n" \
  31                 "| 'bounce back' the packets for Round Trip Time (RTT) measurements.\n" \
  32                 "|\n" \
  33                 "| When the delay parameter is not specified, the default (inter-packet) delay is\n" \
  34                 "| set to 20 msec. You must specify the destination host using the -B option.\n" \
  35                 "| The default destination port is (UDP) 30000 but can be overridden (dp parameter).\n" \
  36                 "| You do not need to specify the count option (-c), because 'infinite' (0) is assumed.\n" \
  37                 "|\n" \
  38                 "| You can specify these additional GENERAL options:\n" \
  39                 "|\n" \
  40                 "|  -c <count>     ..... use this packet count value instead of infinity.\n" \
  41                 "|  -d <delay>     ..... use this delay value instead of the defaul. Per default\n" \
  42                 "|                       the units are microseconds but you can also use msec or sec\n" \
  43                 "|\n" \
  44                 "| You can specify these additional UDP/RTP-specific arguments:\n" \
  45                 "|\n" \
  46                 "|   dp    = <1-65535> ..... use this UDP destination port instead of 30,000.\n" \
  47                 "|   sp    = <1-65535> ..... use this UDP source port instead of random.\n" \
  48                 "|   ssrc  = XX:XX:XX:XX ... use this hex sequence as stream identifier\n" \
  49                 "|                           (=SSRC, required for multiple concurrent measurements)\n" \
  50                 "|   codec             ..... simulate G.711 codec (other will follow).\n" \
  51                 "|   pld = <1..1000> ....... create specified payload size (default=160 bytes, which results\n" \
  52                 "|                           in a total datagram length of 180 bytes, considering the UDP and\n" \
  53                 "|                           RTP header lengths (8 and 12 bytes, respectively).\n" \
  54                 "|\n" \
  55                 "| Additional help: enter 'mz -T rtp help'\n" \
  56                 "|\n"
  57
  58
  59
  60 int create_rtp_packet()
  61 {
  62         u_int8_t byte1, byte2;
  63         u_int16_t seqnr;
  64         u_int8_t ssrc[4] = {0,0,0,0} ;
  65         int ssrc_s = 0;
  66         u_int8_t *ptr;
  67         char argval[MAX_PAYLOAD_SIZE];
  68         unsigned int rtp_payload_size=160;
  69         struct mz_timestamp ts;
  70
  71         if ( (getarg(tx.arg_string,"help", NULL)==1) && (mode==RTP) ) {
  72                 if (mz_port)
  73                 {
  74                         cli_print(gcli, "%s", MZ_RTP_HELP);
  75                         return -1;
  76                 }
  77                 else
  78                 {
  79
  80                         fprintf(stderr,"\n"
  81                                 MAUSEZAHN_VERSION
  82                                 "\n%s", MZ_RTP_HELP);
  83                         exit(0);
  84                 }
  85         }
  86
  87
  88         if (getarg(tx.arg_string,"pld", argval)==1) {
  89                 rtp_payload_size = (unsigned int) str2int(argval);
  90         }
  91
  92         if (getarg(tx.arg_string,"codec", argval)==1) {
  93                 tx.delay = 20000;
  94         }
  95
  96         if (getarg(tx.arg_string,"ssrc", argval)==1) {
  97                 ssrc_s = str2hex(argval, ssrc, 4);
  98                 if (ssrc_s<0) {
  99                         fprintf(stderr, " mz/rtp: invalid ssrc!\n");
 100                         return -1;
 101                 }
 102         }
 103
 104    // TODO: Optional arguments for RTP
 105
 106
 107    // Create header: //
 108
 109    // Byte 1
 110    //
 111    // +--+--+--+--+--+--+--+--+
 112    // | ver | P| X| CSRC Count|
 113    // +--+--+--+--+--+--+--+--+
 114    //
 115    // Default: ver=2, Padding=0, Extension_Header=1, CSRC_Count=0 => 10 0 1 0000 = 0x90
 116
 117         byte1 = 0x90;
 118
 119    // Byte 2
 120    //
 121    // +--+--+--+--+--+--+--+--+
 122    // | M|    Payload Type    |
 123    // +--+--+--+--+--+--+--+--+
 124    //
 125    // Marker=0, Payload Type=0 (or 8 alternatively)
 126
 127         byte2 = 0x00;
 128
 129    // Bytes 3,4
 130    //
 131    // +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
 132    // |               Sequence Number                 |
 133    // +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
 134
 135         seqnr = 0x0000;
 136
 137    // Bytes 5,6,7,8
 138    //
 139    //   Timestamp  /* done below */
 140    //
 141
 142
 143    // Bytes 9,10,11,12
 144    //
 145    //   Synchronization Source Identifier
 146    //
 147
 148         if (ssrc_s==0) str2hex("ca:fe:fe:ed", ssrc, 4);
 149
 150    // Bytes 13,14,15,16
 151    //
 152    //     CSRC - Contributing Source Identifiers (optional, only used by mixers)
 153    //
 154    //   csrc = 0x00000000;
 155
 156    // Bytes 17,18,19,20
 157    //
 158    //   Header Extension (optional) NOT USED HERE!
 159    //
 160
 161    // !!! Thus payload begins with index 16 in a C array !!!
 162
 163    // ------------ Now combine all fields: ----------------
 164    tx.udp_payload[0] = byte1;
 165    tx.udp_payload[1] = byte2;
 166
 167    ptr = (u_int8_t*) &seqnr;
 168    tx.udp_payload[2] = *(ptr+1);
 169    tx.udp_payload[3] = *ptr;
 170
 171    // TIMESTAMP: will be linearly increased, e.g. using 20msec G.711: 0, 160, 320, ...
 172    tx.udp_payload[4] = 0x00;
 173    tx.udp_payload[5] = 0x00;
 174    tx.udp_payload[6] = 0x00;
 175    tx.udp_payload[7] = 0x00;
 176
 177    tx.udp_payload[8] = ssrc[0];
 178    tx.udp_payload[9] = ssrc[1];
 179    tx.udp_payload[10] = ssrc[2];
 180    tx.udp_payload[11] = ssrc[3];
 181
 182    /*
 183    ptr = (u_int8_t*) &csrc;
 184    tx.udp_payload[12] = *(ptr+3);
 185    tx.udp_payload[13] = *(ptr+2);
 186    tx.udp_payload[14] = *(ptr+1);
 187    tx.udp_payload[15] = *ptr;
 188    */
 189
 190    // Add the NEW Mausezahn extension header (see mops_ext_rtp.c)
 191    tx.udp_payload[12] = 0xca;  // identifier
 192    tx.udp_payload[13] = 0xca;
 193    tx.udp_payload[14] = 0x00;
 194    tx.udp_payload[15] = 0x04;  // length
 195    getcurtime(&ts); // Now add TX timestamp:
 196    mops_hton4 ((u_int32_t*) &ts.sec,  &tx.udp_payload[16]);
 197    mops_hton4 ((u_int32_t*) &ts.nsec, &tx.udp_payload[20]);
 198    // NOTE: The remaining 8 bytes of this extension header are set to zero
 199    // via the following code.
 200
 201    memset(&tx.udp_payload[24], 0x00, (rtp_payload_size-12)); // payload (considering our 8 byte timestamp)
 202    tx.udp_payload_s = 12 + rtp_payload_size; // the latter ist the payload size
 203
 204    // ---------- now hand over to UDP -----------------
 205
 206    tx.dp = 30000;
 207    tx.sp = 30000;
 208
 209    tx.udp_len = 8 + tx.udp_payload_s;
 210
 211    return 0;
 212 }
 213
 214
 215
 216
 217