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rtcp.c
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/*! \file rtcp.c
* \author Lorenzo Miniero <lorenzo@meetecho.com>
* \copyright GNU General Public License v3
* \brief RTCP processing
* \details Implementation (based on the oRTP structures) of the RTCP
* messages. RTCP messages coming through the server are parsed and,
* if needed (according to http://tools.ietf.org/html/draft-ietf-straw-b2bua-rtcp-00),
* fixed before they are sent to the peers (e.g., to fix SSRCs that may
* have been changed by the server). Methods to generate FIR messages
* and generate/cap REMB messages are provided as well.
*
* \ingroup protocols
* \ref protocols
*/
#include <math.h>
#include <stdlib.h>
#include <sys/time.h>
#include "debug.h"
#include "rtp.h"
#include "rtcp.h"
#include "utils.h"
/* Transport CC statuses */
typedef enum janus_rtp_packet_status {
janus_rtp_packet_status_notreceived = 0,
janus_rtp_packet_status_smalldelta = 1,
janus_rtp_packet_status_largeornegativedelta = 2,
janus_rtp_packet_status_reserved = 3
} janus_rtp_packet_status;
static const char *janus_rtp_packet_status_description(janus_rtp_packet_status status) {
switch(status) {
case janus_rtp_packet_status_notreceived: return "notreceived";
case janus_rtp_packet_status_smalldelta: return "smalldelta";
case janus_rtp_packet_status_largeornegativedelta: return "largeornegativedelta";
case janus_rtp_packet_status_reserved: return "reserved";
default: break;
}
return NULL;
}
gboolean janus_is_rtcp(char *buf, guint len) {
if (len < 8)
return FALSE;
janus_rtp_header *header = (janus_rtp_header *)buf;
return ((header->type >= 64) && (header->type < 96));
}
int janus_rtcp_parse(janus_rtcp_context *ctx, char *packet, int len) {
return janus_rtcp_fix_ssrc(ctx, packet, len, 0, 0, 0);
}
guint32 janus_rtcp_get_sender_ssrc(char *packet, int len) {
if(packet == NULL || len == 0)
return 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
int pno = 0, total = len;
while(rtcp) {
if (!janus_rtcp_check_len(rtcp, total))
break;
if(rtcp->version != 2)
break;
pno++;
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
return ntohl(sr->ssrc);
}
case RTCP_RR: {
/* RR, receiver report */
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
return ntohl(rr->ssrc);
}
case RTCP_RTPFB: {
/* RTPFB, Transport layer FB message (rfc4585) */
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
return ntohl(rtcpfb->ssrc);
}
case RTCP_PSFB: {
/* PSFB, Payload-specific FB message (rfc4585) */
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
return ntohl(rtcpfb->ssrc);
}
case RTCP_XR: {
/* XR, extended reports (rfc3611) */
janus_rtcp_xr *xr = (janus_rtcp_xr *)rtcp;
return ntohl(xr->ssrc);
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0) {
break;
}
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
guint32 janus_rtcp_get_receiver_ssrc(char *packet, int len) {
if(packet == NULL || len == 0)
return 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
int pno = 0, total = len;
while(rtcp) {
if (!janus_rtcp_check_len(rtcp, total))
break;
if(rtcp->version != 2)
break;
pno++;
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
if (!janus_rtcp_check_sr(rtcp, total))
break;
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
if(sr->header.rc > 0) {
return ntohl(sr->rb[0].ssrc);
}
break;
}
case RTCP_RR: {
/* RR, receiver report */
if (!janus_rtcp_check_rr(rtcp, total))
break;
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
if(rr->header.rc > 0) {
return ntohl(rr->rb[0].ssrc);
}
break;
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0) {
break;
}
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
void janus_rtcp_swap_report_blocks(char *packet, int len, uint32_t rtx_ssrc) {
if(packet == NULL || len == 0)
return;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
int pno = 0, total = len;
while(rtcp) {
if (!janus_rtcp_check_len(rtcp, total))
break;
if(rtcp->version != 2)
break;
pno++;
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
if (!janus_rtcp_check_sr(rtcp, total))
break;
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
if(sr->header.rc >= 2 && ntohl(sr->rb[0].ssrc) == rtx_ssrc) {
janus_report_block rb0_copy = sr->rb[0];
sr->rb[0] = sr->rb[1];
sr->rb[1] = rb0_copy;
}
break;
}
case RTCP_RR: {
/* RR, receiver report */
if (!janus_rtcp_check_rr(rtcp, total))
break;
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
if(rr->header.rc >= 2 && ntohl(rr->rb[0].ssrc) == rtx_ssrc) {
janus_report_block rb0_copy = rr->rb[0];
rr->rb[0] = rr->rb[1];
rr->rb[1] = rb0_copy;
JANUS_LOG(LOG_HUGE, "Switched incoming RTCP Report Blocks %"SCNu32"(rtx) <--> %"SCNu32"\n",
rtx_ssrc, ntohl(rr->rb[0].ssrc));
}
break;
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0) {
break;
}
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
}
/* Helper to handle an incoming SR: triggered by a call to janus_rtcp_fix_ssrc with a valid context pointer */
static void janus_rtcp_incoming_sr(janus_rtcp_context *ctx, janus_rtcp_sr *sr) {
if(ctx == NULL)
return;
/* Update the context with info on the monotonic time of last SR received */
ctx->lsr_ts = janus_get_monotonic_time();
/* Compute the last SR received as well */
uint64_t ntp = ntohl(sr->si.ntp_ts_msw);
ntp = (ntp << 32) | ntohl(sr->si.ntp_ts_lsw);
ctx->lsr = (ntp >> 16);
}
/* Helper to handle an incoming transport-cc feedback: triggered by a call to janus_rtcp_fix_ssrc a valid context pointer */
static void janus_rtcp_incoming_transport_cc(janus_rtcp_context *ctx, janus_rtcp_fb *twcc, int total) {
if(ctx == NULL || twcc == NULL || total < 20)
return;
if(!janus_rtcp_check_fci((janus_rtcp_header *)twcc, total, 4))
return;
/* Parse the header first */
uint8_t *data = (uint8_t *)twcc->fci;
uint16_t base_seq = 0, status_count = 0;
uint32_t reference = 0;
uint8_t fb_pkt = 0;
memcpy(&base_seq, data, sizeof(uint16_t));
base_seq = ntohs(base_seq);
memcpy(&status_count, data+2, sizeof(uint16_t));
status_count = ntohs(status_count);
memcpy(&reference, data+4, sizeof(uint32_t));
reference = ntohl(reference) >> 8;
fb_pkt = *(data+7);
JANUS_LOG(LOG_HUGE, "[TWCC] seq=%"SCNu16", psc=%"SCNu16", ref=%"SCNu32", fbpc=%"SCNu8"\n",
base_seq, status_count, reference, fb_pkt);
/* Now traverse the feedback: packet chunks first, and then recv deltas */
total -= 20;
data += 8;
uint16_t psc = status_count;
uint16_t chunk = 0;
uint8_t t = 0, ss = 0, s = 0, length = 0;
/* Iterate on all packet chunks */
JANUS_LOG(LOG_HUGE, "[TWCC] Chunks:\n");
uint16_t num = 0;
GList *list = NULL;
while(psc > 0 && total > 1) {
num++;
memcpy(&chunk, data, sizeof(uint16_t));
chunk = ntohs(chunk);
t = (chunk & 0x8000) >> 15;
if(t == 0) {
/* Run length */
s = (chunk & 0x6000) >> 13;
length = (chunk & 0x1FFF);
JANUS_LOG(LOG_HUGE, " [%"SCNu16"] t=run-length, s=%s, l=%"SCNu8"\n", num,
janus_rtp_packet_status_description(s), length);
while(length > 0 && psc > 0) {
list = g_list_prepend(list, GUINT_TO_POINTER(s));
length--;
psc--;
}
} else {
/* Status vector */
ss = (chunk & 0x4000) >> 14;
length = (ss ? 7 : 14);
JANUS_LOG(LOG_HUGE, " [%"SCNu16"] t=status-vector, ss=%ss, l=%"SCNu8"\n", num,
ss ? "2-bit" : "bit", length);
while(length > 0 && psc > 0) {
if(!ss)
s = (chunk & (1 << (length-1))) ? janus_rtp_packet_status_smalldelta : janus_rtp_packet_status_notreceived;
else
s = (chunk & (3 << (2*length-2))) >> (2*length-2);
list = g_list_prepend(list, GUINT_TO_POINTER(s));
length--;
psc--;
}
}
total -= 2;
data += 2;
}
if(psc > 0) {
/* Incomplete feedback? Drop... */
g_list_free(list);
return;
}
list = g_list_reverse(list);
/* Iterate on all recv deltas */
JANUS_LOG(LOG_HUGE, "[TWCC] Recv Deltas (%d/%"SCNu16"):\n", g_list_length(list), status_count);
num = 0;
uint16_t delta = 0;
uint32_t delta_us = 0;
GList *iter = list;
while(iter != NULL && total > 0) {
num++;
delta = 0;
s = GPOINTER_TO_UINT(iter->data);
if(s == janus_rtp_packet_status_smalldelta) {
/* Small delta = 1 byte */
delta = *data;
total--;
data++;
} else if(s == janus_rtp_packet_status_largeornegativedelta) {
/* Large or negative delta = 2 bytes */
if(total < 2)
break;
memcpy(&delta, data, sizeof(uint16_t));
delta = ntohs(delta);
total -= 2;
data += 2;
}
delta_us = delta*250;
/* Print summary */
JANUS_LOG(LOG_HUGE, " [%02"SCNu16"][%"SCNu16"] %s (%"SCNu32"us)\n", num, (uint16_t)(base_seq+num-1),
janus_rtp_packet_status_description(s), delta_us);
iter = iter->next;
}
/* TODO Update the context with the feedback we got */
g_list_free(list);
}
/* Link quality estimate filter coefficient */
#define LINK_QUALITY_FILTER_K 3.0
static double janus_rtcp_link_quality_filter(double last, double in) {
/* Note: the last!=last is there to check for NaN */
if(last == 0 || last == in || last != last) {
return in;
} else {
return (1.0 - 1.0/LINK_QUALITY_FILTER_K) * last + (1.0/LINK_QUALITY_FILTER_K) * in;
}
}
/* Update link quality stats based on RR */
static void janus_rtcp_rr_update_stats(rtcp_context *ctx, janus_report_block rb) {
int64_t ts = janus_get_monotonic_time();
int64_t delta_t = ts - ctx->rr_last_ts;
if(delta_t < 2*G_USEC_PER_SEC) {
return;
}
ctx->rr_last_ts = ts;
uint32_t total_lost = ntohl(rb.flcnpl) & 0x00FFFFFF;
if (ctx->rr_last_ehsnr != 0) {
int32_t sent = g_atomic_int_get(&ctx->sent_packets_since_last_rr);
uint32_t expect = ntohl(rb.ehsnr) - ctx->rr_last_ehsnr;
int32_t nacks = g_atomic_int_get(&ctx->nack_count) - ctx->rr_last_nack_count;
/* In case the number of NACKs is higher than the number of sent packets,
* we normalize it and set it to the same value instead, otherwise the
* value of the out link quality will overflow: for details, see
* https://github.com/meetecho/janus-gateway/issues/2579 */
if(sent && nacks > sent)
nacks = sent;
double link_q = !sent ? 0 : 100.0 - (100.0 * nacks / (double)sent);
ctx->out_link_quality = janus_rtcp_link_quality_filter(ctx->out_link_quality, link_q);
int32_t lost = total_lost - ctx->rr_last_lost;
if(lost < 0) {
lost = 0;
}
double media_link_q = !expect ? 0 : 100.0 - (100.0 * lost / (double)expect);
ctx->out_media_link_quality = janus_rtcp_link_quality_filter(ctx->out_media_link_quality, media_link_q);
JANUS_LOG(LOG_HUGE, "Out link quality=%"SCNu32", media link quality=%"SCNu32"\n", janus_rtcp_context_get_out_link_quality(ctx), janus_rtcp_context_get_out_media_link_quality(ctx));
}
ctx->rr_last_ehsnr = ntohl(rb.ehsnr);
ctx->rr_last_lost = total_lost;
ctx->rr_last_nack_count = g_atomic_int_get(&ctx->nack_count);
g_atomic_int_set(&ctx->sent_packets_since_last_rr, 0);
}
/* Helper to handle an incoming RR: triggered by a call to janus_rtcp_fix_ssrc with fixssrc=0 */
static void janus_rtcp_incoming_rr(janus_rtcp_context *ctx, janus_rtcp_rr *rr) {
if(ctx == NULL)
return;
/* FIXME Check the Record Blocks */
if(rr->header.rc > 0) {
double jitter = (double)ntohl(rr->rb[0].jitter);
uint32_t fraction = ntohl(rr->rb[0].flcnpl) >> 24;
uint32_t total = ntohl(rr->rb[0].flcnpl) & 0x00FFFFFF;
JANUS_LOG(LOG_HUGE, "jitter=%f, fraction=%"SCNu32", loss=%"SCNu32"\n", jitter, fraction, total);
ctx->lost_remote = total;
ctx->jitter_remote = jitter;
janus_rtcp_rr_update_stats(ctx, rr->rb[0]);
/* FIXME Compute round trip time */
uint32_t lsr = ntohl(rr->rb[0].lsr);
uint32_t dlsr = ntohl(rr->rb[0].delay);
if(lsr == 0) /* Not enough info yet */
return;
struct timeval tv;
gettimeofday(&tv, NULL);
uint32_t s = tv.tv_sec + 2208988800u;
uint32_t u = tv.tv_usec;
uint32_t f = (u << 12) + (u << 8) - ((u * 3650) >> 6);
uint32_t ntp_ts_msw = s;
uint32_t ntp_ts_lsw = f;
uint64_t temp = ((uint64_t)ntp_ts_msw << 32 ) | ntp_ts_lsw;
uint32_t a = (uint32_t)(temp >> 16);
uint32_t rtt = a - lsr - dlsr;
uint32_t rtt_msw = (rtt & 0xFFFF0000) >> 16;
uint32_t rtt_lsw = rtt & 0x0000FFFF;
tv.tv_sec = rtt_msw;
tv.tv_usec = (rtt_lsw * 15625) >> 10;
ctx->rtt = tv.tv_sec*1000 + tv.tv_usec/1000; /* We need milliseconds */
JANUS_LOG(LOG_HUGE, "rtt=%"SCNu32"\n", ctx->rtt);
}
}
gboolean janus_rtcp_check_len(janus_rtcp_header *rtcp, int len) {
if (len < (int)sizeof(janus_rtcp_header) + (int)sizeof(uint32_t)) {
JANUS_LOG(LOG_VERB, "Packet size is too small (%d bytes) to contain RTCP\n", len);
return FALSE;
}
int header_def_len = 4*(int)ntohs(rtcp->length) + 4;
if (len < header_def_len) {
JANUS_LOG(LOG_VERB, "Invalid RTCP packet defined length, expected %d bytes > actual %d bytes\n", header_def_len, len);
return FALSE;
}
return TRUE;
}
gboolean janus_rtcp_check_sr(janus_rtcp_header *rtcp, int len) {
if (len < (int)sizeof(janus_rtcp_header) + (int)sizeof(uint32_t) + (int)sizeof(sender_info)) {
JANUS_LOG(LOG_VERB, "RTCP Packet is too small (%d bytes) to contain SR\n", len);
return FALSE;
}
int header_rb_len = (int)(rtcp->rc)*(int)sizeof(report_block);
int actual_rb_len = len - (int)sizeof(janus_rtcp_header) - (int)sizeof(uint32_t) - (int)sizeof(sender_info);
if (actual_rb_len < header_rb_len) {
JANUS_LOG(LOG_VERB, "SR got %d RB count, expected %d bytes > actual %d bytes\n", rtcp->rc, header_rb_len, actual_rb_len);
return FALSE;
}
return TRUE;
}
gboolean janus_rtcp_check_rr(janus_rtcp_header *rtcp, int len) {
int header_rb_len = (int)(rtcp->rc)*(int)sizeof(report_block);
int actual_rb_len = len - (int)sizeof(janus_rtcp_header) - (int)sizeof(uint32_t);
if (actual_rb_len < header_rb_len) {
JANUS_LOG(LOG_VERB, "RR got %d RB count, expected %d bytes > actual %d bytes\n", rtcp->rc, header_rb_len, actual_rb_len);
return FALSE;
}
return TRUE;
}
gboolean janus_rtcp_check_fci(janus_rtcp_header *rtcp, int len, int sizeof_fci) {
/* At least one sizeof_fci bytes FCI */
if (len < (int)sizeof(janus_rtcp_header) + 2*(int)sizeof(uint32_t) + sizeof_fci) {
JANUS_LOG(LOG_VERB, "RTCP Packet is too small (%d bytes) to contain at least one %d bytes FCI\n", len, sizeof_fci);
return FALSE;
}
/* Evaluate fci total size */
int fci_size = len - (int)sizeof(janus_rtcp_header) - 2*(int)sizeof(uint32_t);
/* The length of the feedback message is set to 2+(sizeof_fci/4)*N where
N is the number of FCI entries */
int fcis;
switch(sizeof_fci) {
case 0:
fcis = 0;
break;
case 4:
fcis = (int)ntohs(rtcp->length) - 2;
break;
case 8:
fcis = ((int)ntohs(rtcp->length) - 2) >> 1;
break;
default:
fcis = ((int)ntohs(rtcp->length)- 2) / (sizeof_fci >> 2);
break;
}
/* Every FCI is sizeof_fci bytes */
if (fci_size < sizeof_fci*fcis) {
JANUS_LOG(LOG_VERB, "Got %d FCI count, expected %d bytes > actual %d bytes\n", fcis, sizeof_fci*fcis, fci_size);
return FALSE;
}
return TRUE;
}
gboolean janus_rtcp_check_remb(janus_rtcp_header *rtcp, int len) {
/* At least 1 SSRC feedback */
if (len < (int)sizeof(janus_rtcp_header) + 2*(int)sizeof(uint32_t) + 3*(int)sizeof(uint32_t)) {
JANUS_LOG(LOG_VERB, "Packet is too small (%d bytes) to contain REMB\n", len);
return FALSE;
}
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
uint8_t numssrc = *(rtcpfb->fci+4);
/* Evaluate ssrcs total size */
int ssrc_size = len - (int)sizeof(janus_rtcp_header) - 2*(int)sizeof(uint32_t);
/* Every SSRC is 4 bytes */
if (ssrc_size < 4*numssrc) {
JANUS_LOG(LOG_VERB, "REMB got %d SSRC count, expected %d bytes > actual %d bytes\n", numssrc, 4*numssrc, ssrc_size);
return FALSE;
}
return TRUE;
}
int janus_rtcp_fix_ssrc(janus_rtcp_context *ctx, char *packet, int len, int fixssrc, uint32_t newssrcl, uint32_t newssrcr) {
if(packet == NULL || len <= 0)
return -1;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
int pno = 0, total = len;
JANUS_LOG(LOG_HUGE, " Parsing compound packet (total of %d bytes)\n", total);
while(rtcp) {
if (!janus_rtcp_check_len(rtcp, total))
return -2;
if(rtcp->version != 2)
return -2;
pno++;
/* TODO Should we handle any of these packets ourselves, or just relay them? */
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
JANUS_LOG(LOG_HUGE, " #%d SR (200)\n", pno);
if (!janus_rtcp_check_sr(rtcp, total))
return -2;
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
/* If an RTCP context was provided, update it with info on this SR */
janus_rtcp_incoming_sr(ctx, sr);
if(fixssrc && newssrcl) {
sr->ssrc = htonl(newssrcl);
if (sr->header.rc > 0) {
sr->rb[0].ssrc = htonl(newssrcr);
}
}
break;
}
case RTCP_RR: {
/* RR, receiver report */
JANUS_LOG(LOG_HUGE, " #%d RR (201)\n", pno);
if (!janus_rtcp_check_rr(rtcp, total))
return -2;
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
/* If an RTCP context was provided, update it with info on this RR */
janus_rtcp_incoming_rr(ctx, rr);
if(fixssrc && newssrcl) {
rr->ssrc = htonl(newssrcl);
if (rr->header.rc > 0) {
rr->rb[0].ssrc = htonl(newssrcr);
}
}
break;
}
case RTCP_SDES: {
/* SDES, source description */
JANUS_LOG(LOG_HUGE, " #%d SDES (202)\n", pno);
janus_rtcp_sdes *sdes = (janus_rtcp_sdes *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(sdes->chunk.ssrc));
if(fixssrc && newssrcl) {
sdes->chunk.ssrc = htonl(newssrcl);
}
break;
}
case RTCP_BYE: {
/* BYE, goodbye */
JANUS_LOG(LOG_HUGE, " #%d BYE (203)\n", pno);
janus_rtcp_bye *bye = (janus_rtcp_bye *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(bye->ssrc[0]));
if(fixssrc && newssrcl) {
bye->ssrc[0] = htonl(newssrcl);
}
break;
}
case RTCP_APP: {
/* APP, application-defined */
JANUS_LOG(LOG_HUGE, " #%d APP (204)\n", pno);
janus_rtcp_app *app = (janus_rtcp_app *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(app->ssrc));
if(fixssrc && newssrcl) {
app->ssrc = htonl(newssrcl);
}
break;
}
case RTCP_FIR: {
/* FIR, rfc2032 */
JANUS_LOG(LOG_HUGE, " #%d FIR (192)\n", pno);
break;
}
case RTCP_RTPFB: {
/* RTPFB, Transport layer FB message (rfc4585) */
//~ JANUS_LOG(LOG_HUGE, " #%d RTPFB (205)\n", pno);
gint fmt = rtcp->rc;
//~ JANUS_LOG(LOG_HUGE, " -- FMT: %u\n", fmt);
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(rtcpfb->ssrc));
if(fmt == 1) {
JANUS_LOG(LOG_HUGE, " #%d NACK -- RTPFB (205)\n", pno);
/* NACK FCI size is 4 bytes */
if (!janus_rtcp_check_fci(rtcp, total, 4))
return -2;
if(fixssrc && newssrcr) {
rtcpfb->media = htonl(newssrcr);
}
int nacks = ntohs(rtcp->length)-2; /* Skip SSRCs */
if(nacks > 0) {
JANUS_LOG(LOG_DBG, " Got %d nacks\n", nacks);
janus_rtcp_nack *nack = NULL;
uint16_t pid = 0;
uint16_t blp = 0;
int i=0, j=0;
char bitmask[20];
for(i=0; i< nacks; i++) {
nack = (janus_rtcp_nack *)rtcpfb->fci + i;
pid = ntohs(nack->pid);
blp = ntohs(nack->blp);
memset(bitmask, 0, 20);
for(j=0; j<16; j++) {
bitmask[j] = (blp & ( 1 << j )) >> j ? '1' : '0';
}
bitmask[16] = '\n';
JANUS_LOG(LOG_DBG, "[%d] %"SCNu16" / %s\n", i, pid, bitmask);
}
}
} else if(fmt == 3) { /* rfc5104 */
/* TMMBR: http://tools.ietf.org/html/rfc5104#section-4.2.1.1 */
JANUS_LOG(LOG_HUGE, " #%d TMMBR -- RTPFB (205)\n", pno);
if(fixssrc && newssrcr) {
/* TMMBR FCI size is 8 bytes */
if (!janus_rtcp_check_fci(rtcp, total, 8))
return -2;
uint32_t *ssrc = (uint32_t *)rtcpfb->fci;
*ssrc = htonl(newssrcr);
}
} else if(fmt == 15) { /* transport-cc */
/* If an RTCP context was provided, parse this transport-cc feedback */
janus_rtcp_incoming_transport_cc(ctx, rtcpfb, total);
} else {
JANUS_LOG(LOG_HUGE, " #%d ??? -- RTPFB (205, fmt=%d)\n", pno, fmt);
}
if(fixssrc && newssrcl) {
rtcpfb->ssrc = htonl(newssrcl);
}
break;
}
case RTCP_PSFB: {
/* PSFB, Payload-specific FB message (rfc4585) */
//~ JANUS_LOG(LOG_HUGE, " #%d PSFB (206)\n", pno);
gint fmt = rtcp->rc;
//~ JANUS_LOG(LOG_HUGE, " -- FMT: %u\n", fmt);
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(rtcpfb->ssrc));
if(fmt == 1) {
JANUS_LOG(LOG_HUGE, " #%d PLI -- PSFB (206)\n", pno);
/* PLI does not require parameters. Therefore, the length field MUST be
2, and there MUST NOT be any Feedback Control Information. */
if(fixssrc && newssrcr) {
if (!janus_rtcp_check_fci(rtcp, total, 0))
return -2;
rtcpfb->media = htonl(newssrcr);
}
} else if(fmt == 2) {
JANUS_LOG(LOG_HUGE, " #%d SLI -- PSFB (206)\n", pno);
} else if(fmt == 3) {
JANUS_LOG(LOG_HUGE, " #%d RPSI -- PSFB (206)\n", pno);
} else if(fmt == 4) { /* rfc5104 */
/* FIR: http://tools.ietf.org/html/rfc5104#section-4.3.1.1 */
JANUS_LOG(LOG_HUGE, " #%d FIR -- PSFB (206)\n", pno);
if(fixssrc && newssrcr) {
/* FIR FCI size is 8 bytes */
if (!janus_rtcp_check_fci(rtcp, total, 8))
return -2;
rtcpfb->media = htonl(newssrcr);
uint32_t *ssrc = (uint32_t *)rtcpfb->fci;
*ssrc = htonl(newssrcr);
}
} else if(fmt == 5) { /* rfc5104 */
/* TSTR: http://tools.ietf.org/html/rfc5104#section-4.3.2.1 */
JANUS_LOG(LOG_HUGE, " #%d PLI -- TSTR (206)\n", pno);
} else if(fmt == 15) {
//~ JANUS_LOG(LOG_HUGE, " -- This is a AFB!\n");
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
if(fixssrc && newssrcr) {
/* AFB FCI size is variable, check just media SSRC */
if (!janus_rtcp_check_fci(rtcp, total, 0))
return -2;
rtcpfb->ssrc = htonl(newssrcr);
rtcpfb->media = 0;
}
janus_rtcp_fb_remb *remb = (janus_rtcp_fb_remb *)rtcpfb->fci;
if(janus_rtcp_check_remb(rtcp, total) && remb->id[0] == 'R' && remb->id[1] == 'E' && remb->id[2] == 'M' && remb->id[3] == 'B') {
JANUS_LOG(LOG_HUGE, " #%d REMB -- PSFB (206)\n", pno);
if(fixssrc && newssrcr) {
remb->ssrc[0] = htonl(newssrcr);
}
/* FIXME From rtcp_utility.cc */
unsigned char *_ptrRTCPData = (unsigned char *)remb;
_ptrRTCPData += 4; // Skip unique identifier and num ssrc
//~ JANUS_LOG(LOG_HUGE, " %02X %02X %02X %02X\n", _ptrRTCPData[0], _ptrRTCPData[1], _ptrRTCPData[2], _ptrRTCPData[3]);
uint8_t numssrc = (_ptrRTCPData[0]);
uint8_t brExp = (_ptrRTCPData[1] >> 2) & 0x3F;
uint32_t brMantissa = (_ptrRTCPData[1] & 0x03) << 16;
brMantissa += (_ptrRTCPData[2] << 8);
brMantissa += (_ptrRTCPData[3]);
uint32_t bitRate = (uint64_t)brMantissa << brExp;
JANUS_LOG(LOG_HUGE, " -- -- -- REMB: %u * 2^%u = %"SCNu32" (%d SSRCs, %u)\n",
brMantissa, brExp, bitRate, numssrc, ntohl(remb->ssrc[0]));
} else {
JANUS_LOG(LOG_HUGE, " #%d AFB ?? -- PSFB (206)\n", pno);
}
} else {
JANUS_LOG(LOG_HUGE, " #%d ?? -- PSFB (206, fmt=%d)\n", pno, fmt);
}
if(fixssrc && newssrcl) {
rtcpfb->ssrc = htonl(newssrcl);
}
break;
}
case RTCP_XR: {
/* XR, extended reports (rfc3611) */
janus_rtcp_xr *xr = (janus_rtcp_xr *)rtcp;
if(fixssrc && newssrcl) {
xr->ssrc = htonl(newssrcl);
}
/* TODO Fix report blocks too, once we support them */
break;
}
default:
JANUS_LOG(LOG_ERR, " Unknown RTCP PT %d\n", rtcp->type);
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
JANUS_LOG(LOG_HUGE, " RTCP PT %d, length: %d bytes\n", rtcp->type, length*4+4);
if(length == 0) {
//~ JANUS_LOG(LOG_HUGE, " 0-length, end of compound packet\n");
break;
}
total -= length*4+4;
//~ JANUS_LOG(LOG_HUGE, " Packet has length %d (%d bytes, %d remaining), moving to next one...\n", length, length*4+4, total);
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
char *janus_rtcp_filter(char *packet, int len, int *newlen) {
if(packet == NULL || len <= 0 || newlen == NULL)
return NULL;
*newlen = 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
char *filtered = NULL;
int total = len, length = 0, bytes = 0;
/* Iterate on the compound packets */
gboolean keep = TRUE;
gboolean error = FALSE;
while(rtcp) {
if (!janus_rtcp_check_len(rtcp, total)) {
error = TRUE;
break;
}
if(rtcp->version != 2) {
error = TRUE;
break;
}
keep = TRUE;
length = ntohs(rtcp->length);
if(length == 0)
break;
bytes = length*4+4;
switch(rtcp->type) {
case RTCP_SR:
case RTCP_RR:
case RTCP_SDES:
/* These are packets we generate ourselves, so remove them */
keep = FALSE;
break;
case RTCP_BYE:
case RTCP_APP:
case RTCP_FIR:
case RTCP_PSFB:
break;
case RTCP_RTPFB:
if(rtcp->rc == 1) {
/* We handle NACKs ourselves as well, remove this too */
keep = FALSE;
break;
} else if(rtcp->rc == 15) {
/* We handle Transport Wide CC ourselves as well, remove this too */
keep = FALSE;
break;
}
break;
case RTCP_XR:
/* FIXME We generate RR/SR ourselves, so remove XR */
keep = FALSE;
break;
default:
JANUS_LOG(LOG_ERR, "Unknown RTCP PT %d\n", rtcp->type);
/* FIXME Should we allow this to go through instead? */
keep = FALSE;
break;
}
if(keep) {
/* Keep this packet */
if(filtered == NULL)
filtered = g_malloc0(total);
memcpy(filtered+*newlen, (char *)rtcp, bytes);
*newlen += bytes;
}
total -= bytes;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
if (error) {
g_free(filtered);
filtered = NULL;
*newlen = 0;
}
return filtered;
}
int janus_rtcp_process_incoming_rtp(janus_rtcp_context *ctx, char *packet, int len,
gboolean rfc4588_pkt, gboolean rfc4588_enabled, gboolean retransmissions_disabled,
GHashTable *clock_rates) {
if(ctx == NULL || packet == NULL || len < 1)
return -1;
/* First of all, let's check if we need to change the timestamp base */
janus_rtp_header *rtp = (janus_rtp_header *)packet;
int pt = rtp->type;
uint32_t clock_rate = clock_rates ?
GPOINTER_TO_UINT(g_hash_table_lookup(clock_rates, GINT_TO_POINTER(pt))) : 0;
if(clock_rate > 0 && ctx->tb != clock_rate)
ctx->tb = clock_rate;
/* Now parse this RTP packet header and update the rtcp_context instance */
uint16_t seq_number = ntohs(rtp->seq_number);
if(ctx->base_seq == 0 && ctx->seq_cycle == 0)
ctx->base_seq = seq_number;
int64_t now = janus_get_monotonic_time();
if (!rfc4588_pkt) {
/* Non-RTX packet */
if ((int16_t)(seq_number - ctx->max_seq_nr) > 0) {
/* In-order packet */
ctx->received++;
if(seq_number < ctx->max_seq_nr)
ctx->seq_cycle++;
ctx->max_seq_nr = seq_number;
uint32_t rtp_expected = 0x0;
if(ctx->seq_cycle > 0) {
rtp_expected = ctx->seq_cycle;
rtp_expected = rtp_expected << 16;
}
rtp_expected = rtp_expected + 1 + ctx->max_seq_nr - ctx->base_seq;
ctx->expected = rtp_expected;
int64_t arrival = (now * ctx->tb) / 1000000;
int64_t transit = arrival - ntohl(rtp->timestamp);
if (ctx->transit != 0) {
int64_t d = transit - ctx->transit;
if (d < 0) d = -d;
ctx->jitter += (1./16.) * ((double)d - ctx->jitter);
}
ctx->transit = transit;
ctx->rtp_last_inorder_ts = ntohl(rtp->timestamp);
ctx->rtp_last_inorder_time = now;
} else {
/* Out-of-order packet */
if (rfc4588_enabled) {
/* Just an out-of-order packet in a stream that is using a dedicated RTX channel */
ctx->received++;
} else {
/* The stream does not have a rtx channel dedicated to retransmissions */
if (!retransmissions_disabled) {
/* The stream does have a retransmission mechanism (e.g. video w/ NACKs) */
/* Try to detect the retransmissions */
/* TODO We have to accomplish this in a smarter way */
int32_t rtp_diff = ntohl(rtp->timestamp) - ctx->rtp_last_inorder_ts;
int64_t ms_diff = ((int64_t)abs(rtp_diff) * 1000) / ctx->tb;
if (ms_diff > 120)
ctx->retransmitted++;
else
ctx->received++;
} else {
/* The stream does not have a retransmission mechanism (e.g. audio wo/ NACKs) */
ctx->received++;
}
}
}
} else {
/* RTX packet, just increase retransmitted count */
ctx->retransmitted++;
}
/* RTP packet received: it means we can start sending RR */
ctx->rtp_recvd = 1;
return 0;
}
uint32_t janus_rtcp_context_get_rtt(janus_rtcp_context *ctx) {
return ctx ? ctx->rtt : 0;
}
uint32_t janus_rtcp_context_get_in_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->in_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_in_media_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->in_media_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_out_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->out_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_out_media_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->out_media_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_lost_all(janus_rtcp_context *ctx, gboolean remote) {
if(ctx == NULL)
return 0;
return remote ? ctx->lost_remote : ctx->lost;
}
static uint32_t janus_rtcp_context_get_lost(janus_rtcp_context *ctx) {
if(ctx == NULL)
return 0;
uint32_t lost;
if(ctx->lost > 0x7FFFFF) {
lost = 0x7FFFFF;
} else {
lost = ctx->lost;
}
return lost;
}
static uint32_t janus_rtcp_context_get_lost_fraction(janus_rtcp_context *ctx) {
if(ctx == NULL)
return 0;
uint32_t expected_interval = ctx->expected - ctx->expected_prior;
uint32_t received_interval = ctx->received - ctx->received_prior;
int32_t lost_interval = expected_interval - received_interval;
uint32_t fraction;
if(expected_interval == 0 || lost_interval <=0)
fraction = 0;
else
fraction = (lost_interval << 8) / expected_interval;
return fraction << 24;
}
uint32_t janus_rtcp_context_get_jitter(janus_rtcp_context *ctx, gboolean remote) {
if(ctx == NULL || ctx->tb == 0)
return 0;
return (uint32_t) floor((remote ? ctx->jitter_remote : ctx->jitter) / (ctx->tb/1000));
}
static void janus_rtcp_estimate_in_link_quality(janus_rtcp_context *ctx) {
uint32_t expected_interval = ctx->expected - ctx->expected_prior;
uint32_t received_interval = ctx->received - ctx->received_prior;
uint32_t retransmitted_interval = ctx->retransmitted - ctx->retransmitted_prior;
/* Link lost is calculated without considering any retransmission */
int32_t link_lost = expected_interval - received_interval;
if (link_lost < 0) {
link_lost = 0;
}
double link_q = !expected_interval ? 0 : 100.0 - (100.0 * (double)link_lost / (double)expected_interval);
ctx->in_link_quality = janus_rtcp_link_quality_filter(ctx->in_link_quality, link_q);
/* Media lost is calculated considering also retransmitted packets */
int32_t media_lost = expected_interval - (received_interval + retransmitted_interval);
if (media_lost < 0) {
media_lost = 0;
}
double media_link_q = !expected_interval ? 0 : 100.0 - (100.0 * (double)media_lost / (double)expected_interval);
ctx->in_media_link_quality = janus_rtcp_link_quality_filter(ctx->in_media_link_quality, media_link_q);
JANUS_LOG(LOG_HUGE, "In link quality=%"SCNu32", media link quality=%"SCNu32"\n", janus_rtcp_context_get_in_link_quality(ctx), janus_rtcp_context_get_in_media_link_quality(ctx));
}
int janus_rtcp_report_block(janus_rtcp_context *ctx, janus_report_block *rb) {
if(ctx == NULL || rb == NULL)
return -1;
gint64 now = janus_get_monotonic_time();
rb->jitter = htonl((uint32_t) ctx->jitter);
rb->ehsnr = htonl((((uint32_t) 0x0 + ctx->seq_cycle) << 16) + ctx->max_seq_nr);
uint32_t expected_interval = ctx->expected - ctx->expected_prior;
uint32_t received_interval = ctx->received - ctx->received_prior;
int32_t lost_interval = 0;
if (expected_interval > received_interval) {
lost_interval = expected_interval - received_interval;
}
ctx->lost += lost_interval;
uint32_t reported_lost = janus_rtcp_context_get_lost(ctx);
uint32_t reported_fraction = janus_rtcp_context_get_lost_fraction(ctx);
janus_rtcp_estimate_in_link_quality(ctx);
ctx->expected_prior = ctx->expected;
ctx->received_prior = ctx->received;
ctx->retransmitted_prior = ctx->retransmitted;
rb->flcnpl = htonl(reported_lost | reported_fraction);
if(ctx->lsr > 0) {