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/*
* Mausezahn - A fast versatile traffic generator
* Copyright (C) 2008-2010 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 "mops.h"
#include "cli.h"
// Initialization function - specify defaults here!
//
int mops_init_pdesc_rtp(struct mops *mp)
{
struct mops_ext_rtp * pd;
if (mp->p_desc == NULL) return 1; // p_desc not properly assigned
pd = mp->p_desc;
// set RTP defaults
pd->v = 2;
pd->p = 0;
pd->x = 0;
pd->cc = 0;
pd->m = 0;
pd->pt = 8; // 0=PCMU, 8=PCMA
pd->sqnr = 0;
pd->tst = 0;
pd->tst_inc = 160;
pd->ssrc = mz_rand32(); // Default Mausezahn stream would be 0xCAFEBABE
pd->source = 0; // don't use /dev/dsp (but user may configure source = DSP_SOURCE)
pd->cc_real = 0;
pd->x_type = 0; // no extension by default
// General packet parameters
mp->dp = 30000;
mp->sp = 30002;
mp->ndelay.tv_sec = 0;
mp->ndelay.tv_nsec = 20000000;
memset(&pd->payload, 0x00, MOPS_RTP_MAX_PAYLOAD_SIZE);
return 0;
}
/*
* Standard RTP header according RFC 3550
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |V=2|P|X| CC |M| PT | sequence number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | timestamp |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | synchronization source (SSRC) identifier |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* | contributing source (CSRC) identifiers |
* | .... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* !!! NOTE !!! -- This function should be used only to prepare the RTP
* header once. It does not update dynamic fields. To update dynamic fields
* each time a subsequent RTP packet is sent, use the function
* mops_update_rtp_dynamics().
*
*/
int mops_update_rtp (struct mops * mp)
{
struct mops_ext_rtp * pd;
int i,j;
pd = mp->p_desc;
if (pd==NULL) return 1; // no valid pointer to a p_desc
mp->msg_s = 0; // !! IMPORTANT !! Otherwise the msg would get longer and longer after each call!
// 1st byte
mops_msg_add_byte (mp, pd->cc);
mops_msg_add_field (mp, pd->v, 6);
mops_msg_add_field (mp, pd->p, 5);
mops_msg_add_field (mp, pd->x, 4);
// 2nd byte
mops_msg_add_byte (mp, pd->pt);
mops_msg_add_field (mp, pd->m, 7);
// remaining
mops_msg_add_2bytes (mp, pd->sqnr);
mops_msg_add_4bytes (mp, pd->tst);
mops_msg_add_4bytes (mp, pd->ssrc);
// Add CSRC list?
if ((j=pd->cc_real)) {
if (j>16) { j=16; pd->cc_real=16; } // silent self healing if desired :-)
for (i=0; i<j; i++)
mops_msg_add_4bytes (mp, pd->csrc[i]);
}
pd->rtp_header_len = 12 + j*4;
/*
* Add Extension header?
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | defined by profile | length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | header extension |
* | .... |
*/
switch (pd->x_type) {
case 0: // none
break;
case 1: // set aero, 8 bytes in total -- TODO --
break;
case 42: // Mausezahn extension header:
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | MOPS_RTP_EXT_MZID | length=4 |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | TX-timestamp sec |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | TX-timestamp nsec |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Estimated Peer TX-timestamp sec |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Estimated Peer TX-timestamp nsec |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
mops_msg_add_2bytes (mp, MOPS_RTP_EXT_MZID);
mops_msg_add_2bytes (mp, 2);
mops_msg_add_4bytes (mp, 0); // only placeholders, must be updated each packet
mops_msg_add_4bytes (mp, 0); // only placeholders, must be updated each packet
mops_msg_add_4bytes (mp, 0); // only placeholders, must be updated each packet
mops_msg_add_4bytes (mp, 0); // only placeholders, must be updated each packet
pd->rtp_header_len += 20;
break;
default:
return 1;
break; // paranoid?
}
// Now add the payload
switch (pd->pt) {
case 0:
case 8:
mp->msg_s = 160 + pd->rtp_header_len; // simply set total RTP PDU length (the RTP payload is still undefined)
mp->ndelay.tv_sec = 0;
mp->ndelay.tv_nsec = 20000000;
break;
default:
break;
}
return 0;
}
// This function directly updates the dynamic RTP fields
// within the mops frame (=be quick here).
//
// This function is typically called from within the transmission loops,
// see e. g. mops_tx_thread_native()
//
// This includes:
//
// - RTP SQNR
// - RTP Timestamp
// - Mausezahn extension header if any
// - The RTP payload
//
int mops_update_rtp_dynamics (struct mops * mp)
{
struct mops_ext_rtp * pd;
struct timespec ct;
int j, i = mp->begin_MSG;
pd = mp->p_desc; if (pd==NULL) return 1;
// The following variables must be incremented AFTER assignment to frame,
// so the initial values are also used!
//
mops_hton2 (&pd->sqnr, &mp->frame[i+2]);
pd->sqnr++;
mops_hton4 (&pd->tst, &mp->frame[i+4]);
pd->tst += pd->tst_inc;
// Extension header:
// Timestamp must be updated BEFORE assignment to frame
//
switch (pd->x_type) {
case 42: // Mausezahn extension header: Update timestamps
j = i + pd->rtp_header_len; // points to first byte of timestamp of MZ extension header
clock_gettime(CLOCK_MONOTONIC, &ct);
mops_hton4 ((u_int32_t*) &ct.tv_sec, &mp->frame[j-16]);
mops_hton4 ((u_int32_t*) &ct.tv_nsec, &mp->frame[j-12]);
//[TODO] **** estimated peer timestamp **** PSEUDOCODE FOLLOWING:
// if (peer_exists) {
// get_peer_timestamp_estimation(&est);
// mops_hton4 ((u_int32_t*) &est.sec, &mp->frame[j-8]);
// mops_hton4 ((u_int32_t*) &est.nsec, &mp->frame[j-4]);
// }
break;
default:
return 0;
break;
}
// The pd->payload contains either zeroes or realtime voice data
// The pd->payload is initialized with zeroes and IFF a reading thread
// exists, it may copy voice segments (e. g. from /dev/dsp) to
// pd->payload.
// NOTE that there is NO NEED to protect pd->payload with mutexes, because
// only if the reading thread is finished it (itself!) will call THIS function.
if (pd->source == DSP_SOURCE) {
memcpy((void*) &mp->frame[j], (void*) pd->payload, pd->payload_s);
}
return 0;
}
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