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/*
* Mausezahn - A fast versatile traffic generator
* Copyright (C) 2008 Herbert Haas
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation.
*
* 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, see http://www.gnu.org/licenses/gpl-2.0.html
*
*/
#include "mz.h"
#include "cli.h"
#include "mops.h"
#define MZ_RTP_HELP \
"| RTP type: Send Real Time Protocol packets.\n" \
"|\n" \
"| This mode is solely intended to conduct delay, drop, and jitter measurements in\n" \
"| Voice (Video) over IP networks. You will typically initiate another Mausezahn\n" \
"| instance on the destination host, which will perform the measurements or even\n" \
"| 'bounce back' the packets for Round Trip Time (RTT) measurements.\n" \
"|\n" \
"| When the delay parameter is not specified, the default (inter-packet) delay is\n" \
"| set to 20 msec. You must specify the destination host using the -B option.\n" \
"| The default destination port is (UDP) 30000 but can be overridden (dp parameter).\n" \
"| You do not need to specify the count option (-c), because 'infinite' (0) is assumed.\n" \
"|\n" \
"| You can specify these additional GENERAL options:\n" \
"|\n" \
"| -c <count> ..... use this packet count value instead of infinity.\n" \
"| -d <delay> ..... use this delay value instead of the defaul. Per default\n" \
"| the units are microseconds but you can also use msec or sec\n" \
"|\n" \
"| You can specify these additional UDP/RTP-specific arguments:\n" \
"|\n" \
"| dp = <1-65535> ..... use this UDP destination port instead of 30,000.\n" \
"| sp = <1-65535> ..... use this UDP source port instead of random.\n" \
"| ssrc = XX:XX:XX:XX ... use this hex sequence as stream identifier\n" \
"| (=SSRC, required for multiple concurrent measurements)\n" \
"| codec ..... simulate G.711 codec (other will follow).\n" \
"| pld = <1..1000> ....... create specified payload size (default=160 bytes, which results\n" \
"| in a total datagram length of 180 bytes, considering the UDP and\n" \
"| RTP header lengths (8 and 12 bytes, respectively).\n" \
"|\n" \
"| Additional help: enter 'mz -T rtp help'\n" \
"|\n"
int create_rtp_packet()
{
u_int8_t byte1, byte2;
u_int16_t seqnr;
u_int8_t ssrc[4] = {0,0,0,0} ;
int ssrc_s = 0;
u_int8_t *ptr;
char argval[MAX_PAYLOAD_SIZE];
unsigned int rtp_payload_size=160;
struct mz_timestamp ts;
if ( (getarg(tx.arg_string,"help", NULL)==1) && (mode==RTP) ) {
if (mz_port)
{
cli_print(gcli, "%s", MZ_RTP_HELP);
return -1;
}
else
{
fprintf(stderr,"\n"
MAUSEZAHN_VERSION
"\n%s", MZ_RTP_HELP);
exit(0);
}
}
if (getarg(tx.arg_string,"pld", argval)==1) {
rtp_payload_size = (unsigned int) str2int(argval);
}
if (getarg(tx.arg_string,"codec", argval)==1) {
tx.delay = 20000;
}
if (getarg(tx.arg_string,"ssrc", argval)==1) {
ssrc_s = str2hex(argval, ssrc, 4);
if (ssrc_s<0) {
fprintf(stderr, " mz/rtp: invalid ssrc!\n");
return -1;
}
}
// TODO: Optional arguments for RTP
// Create header: //
// Byte 1
//
// +--+--+--+--+--+--+--+--+
// | ver | P| X| CSRC Count|
// +--+--+--+--+--+--+--+--+
//
// Default: ver=2, Padding=0, Extension_Header=1, CSRC_Count=0 => 10 0 1 0000 = 0x90
byte1 = 0x90;
// Byte 2
//
// +--+--+--+--+--+--+--+--+
// | M| Payload Type |
// +--+--+--+--+--+--+--+--+
//
// Marker=0, Payload Type=0 (or 8 alternatively)
byte2 = 0x00;
// Bytes 3,4
//
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | Sequence Number |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
seqnr = 0x0000;
// Bytes 5,6,7,8
//
// Timestamp /* done below */
//
// Bytes 9,10,11,12
//
// Synchronization Source Identifier
//
if (ssrc_s==0) str2hex("ca:fe:fe:ed", ssrc, 4);
// Bytes 13,14,15,16
//
// CSRC - Contributing Source Identifiers (optional, only used by mixers)
//
// csrc = 0x00000000;
// Bytes 17,18,19,20
//
// Header Extension (optional) NOT USED HERE!
//
// !!! Thus payload begins with index 16 in a C array !!!
// ------------ Now combine all fields: ----------------
tx.udp_payload[0] = byte1;
tx.udp_payload[1] = byte2;
ptr = (u_int8_t*) &seqnr;
tx.udp_payload[2] = *(ptr+1);
tx.udp_payload[3] = *ptr;
// TIMESTAMP: will be linearly increased, e.g. using 20msec G.711: 0, 160, 320, ...
tx.udp_payload[4] = 0x00;
tx.udp_payload[5] = 0x00;
tx.udp_payload[6] = 0x00;
tx.udp_payload[7] = 0x00;
tx.udp_payload[8] = ssrc[0];
tx.udp_payload[9] = ssrc[1];
tx.udp_payload[10] = ssrc[2];
tx.udp_payload[11] = ssrc[3];
/*
ptr = (u_int8_t*) &csrc;
tx.udp_payload[12] = *(ptr+3);
tx.udp_payload[13] = *(ptr+2);
tx.udp_payload[14] = *(ptr+1);
tx.udp_payload[15] = *ptr;
*/
// Add the NEW Mausezahn extension header (see mops_ext_rtp.c)
tx.udp_payload[12] = 0xca; // identifier
tx.udp_payload[13] = 0xca;
tx.udp_payload[14] = 0x00;
tx.udp_payload[15] = 0x04; // length
getcurtime(&ts); // Now add TX timestamp:
mops_hton4 ((u_int32_t*) &ts.sec, &tx.udp_payload[16]);
mops_hton4 ((u_int32_t*) &ts.nsec, &tx.udp_payload[20]);
// NOTE: The remaining 8 bytes of this extension header are set to zero
// via the following code.
memset(&tx.udp_payload[24], 0x00, (rtp_payload_size-12)); // payload (considering our 8 byte timestamp)
tx.udp_payload_s = 12 + rtp_payload_size; // the latter ist the payload size
// ---------- now hand over to UDP -----------------
tx.dp = 30000;
tx.sp = 30000;
tx.udp_len = 8 + tx.udp_payload_s;
return 0;
}
|
