/**
* @brief Switch on the security.
*
* ZRTP calls this method after it has computed the SAS and checked
* if it was verified in the past.
*
* This method must enable SRTP processing if it was not enabled
* during setSecretsReady().
*
* This call will trigger an event which shall be catched by linphone_call_handle_stream_events
*
* @param[in] clientData Pointer to our ZrtpContext structure used to retrieve RTP session
* @param[in] sas The SAS string(4 characters, not null terminated, fixed length)
* @param[in] verified if <code>verified</code> is true then SAS was verified by both parties during a previous call.
*/
static int ms_zrtp_startSrtpSession(void *clientData, const char* sas, int32_t verified ){
MSZrtpContext *userData = (MSZrtpContext *)clientData;
// srtp processing is enabled in SecretsReady fuction when receiver secrets are ready
// Indeed, the secrets on is called before both parts are given to secretsReady.
OrtpEventData *eventData;
OrtpEvent *ev;
if (sas != NULL) {
ev=ortp_event_new(ORTP_EVENT_ZRTP_SAS_READY);
eventData=ortp_event_get_data(ev);
// support both b32 and b256 format SAS strings
snprintf(eventData->info.zrtp_sas.sas, sizeof(eventData->info.zrtp_sas.sas), "%s", sas);
eventData->info.zrtp_sas.verified=(verified != 0) ? TRUE : FALSE;
rtp_session_dispatch_event(userData->stream_sessions->rtp_session, ev);
ms_message("ZRTP secrets on: SAS is %.32s previously verified %s", sas, verified == 0 ? "no" : "yes");
}
ev=ortp_event_new(ORTP_EVENT_ZRTP_ENCRYPTION_CHANGED);
eventData=ortp_event_get_data(ev);
eventData->info.zrtp_stream_encrypted=1;
rtp_session_dispatch_event(userData->stream_sessions->rtp_session, ev);
ms_message("Event dispatched to all: secrets are on");
return 0;
}
static void notify_sent_rtcp(RtpSession *session, mblk_t *rtcp){
if (session->eventqs!=NULL){
OrtpEvent *ev;
OrtpEventData *evd;
ev=ortp_event_new(ORTP_EVENT_RTCP_PACKET_EMITTED);
evd=ortp_event_get_data(ev);
evd->packet=dupmsg(rtcp);
rtp_session_dispatch_event(session,ev);
}
}
static void notify_tev(RtpSession *session, telephone_event_t *event){
OrtpEvent *ev;
OrtpEventData *evd;
rtp_signal_table_emit2(&session->on_telephone_event,(long)(long)event[0].event);
if (session->eventqs!=NULL){
ev=ortp_event_new(ORTP_EVENT_TELEPHONE_EVENT);
evd=ortp_event_get_data(ev);
evd->packet=dupmsg(session->current_tev);
evd->info.telephone_event=event[0].event;
rtp_session_dispatch_event(session,ev);
}
}
static void ms_dtls_srtp_check_channels_status(MSDtlsSrtpContext *ctx) {
if ((ctx->rtp_channel_status == DTLS_STATUS_HANDSHAKE_OVER) && (ctx->rtcp_channel_status == DTLS_STATUS_HANDSHAKE_OVER)) {
OrtpEventData *eventData;
OrtpEvent *ev;
/* send event */
ev=ortp_event_new(ORTP_EVENT_DTLS_ENCRYPTION_CHANGED);
eventData=ortp_event_get_data(ev);
eventData->info.dtls_stream_encrypted=1;
rtp_session_dispatch_event(ctx->stream_sessions->rtp_session, ev);
ms_message("DTLS Event dispatched to all: secrets are on for this stream");
}
}
/**
* Switch on the security.
*
* ZRTP calls this method after it has computed the SAS and check
* if it is verified or not. In addition ZRTP provides information
* about the cipher algorithm and key length for the SRTP session.
*
* This method must enable SRTP processing if it was not enabled
* during sertSecretsReady().
*
* @param ctx
* Pointer to the opaque ZrtpContext structure.
* @param c The name of the used cipher algorithm and mode, or
* NULL
*
* @param s The SAS string
*
* @param verified if <code>verified</code> is true then SAS was
* verified by both parties during a previous call.
*/
static void ozrtp_rtpSecretsOn (ZrtpContext* ctx, char* c, char* s, int32_t verified ){
// OrtpZrtpContext *userData = user_data(ctx);
// srtp processing is enabled in SecretsReady fuction when receiver secrets are ready
// Indeed, the secrets on is called before both parts are given to secretsReady.
OrtpEventData *eventData;
OrtpEvent *ev;
ev=ortp_event_new(ORTP_EVENT_ZRTP_SAS_READY);
eventData=ortp_event_get_data(ev);
memcpy(eventData->info.zrtp_sas.sas,s,4);
eventData->info.zrtp_sas.sas[4]=0;
eventData->info.zrtp_sas.verified=(verified != 0) ? TRUE : FALSE;
rtp_session_dispatch_event(user_data(ctx)->session, ev);
ortp_message("ZRTP secrets on: SAS is %s previously verified %s - algo %s", s, verified == 0 ? "no" : "yes", c);
}
/**
* Send information messages to the hosting environment.
*
* The ZRTP implementation uses this method to send information
* messages to the host. Along with the message ZRTP provides a
* severity indicator that defines: Info, Warning, Error,
* Alert. Refer to the <code>MessageSeverity</code> enum above.
*
* @param ctx
* Pointer to the opaque ZrtpContext structure.
* @param severity
* This defines the message's severity
* @param subCode
* The subcode identifying the reason.
* @see ZrtpCodes#MessageSeverity
*/
static void ozrtp_sendInfo (ZrtpContext* ctx, int32_t severity, int32_t subCode ) {
const char* submsg;
switch (subCode) {
case zrtp_InfoHelloReceived:
/*!< Hello received, preparing a Commit */
submsg="zrtp_InfoHelloReceived";
break;
case zrtp_InfoCommitDHGenerated:
/*!< Commit: Generated a public DH key */
submsg="zrtp_InfoCommitDHGenerated";
break;
case zrtp_InfoRespCommitReceived:
/*!< Responder: Commit received, preparing DHPart1 */
submsg="zrtp_InfoRespCommitReceived";
break;
case zrtp_InfoDH1DHGenerated:
/*!< DH1Part: Generated a public DH key */
submsg="zrtp_InfoDH1DHGenerated";
break;
case zrtp_InfoInitDH1Received:
/*!< Initiator: DHPart1 received, preparing DHPart2 */
submsg="zrtp_InfoInitDH1Received";
break;
case zrtp_InfoRespDH2Received:
/*!< Responder: DHPart2 received, preparing Confirm1 */
submsg="zrtp_InfoRespDH2Received";
break;
case zrtp_InfoInitConf1Received:
/*!< Initiator: Confirm1 received, preparing Confirm2 */
submsg="zrtp_InfoInitConf1Received";
break;
case zrtp_InfoRespConf2Received:
/*!< Responder: Confirm2 received, preparing Conf2Ack */
submsg="zrtp_InfoRespConf2Received";
break;
case zrtp_InfoRSMatchFound:
/*!< At least one retained secrets matches - security OK */
submsg="zrtp_InfoRSMatchFound";
break;
case zrtp_InfoSecureStateOn:
/*!< Entered secure state */
submsg="zrtp_InfoSecureStateOn";
break;
case zrtp_InfoSecureStateOff:
/*!< No more security for this session */
submsg="zrtp_InfoSecureStateOff";
break;
default:
submsg="unkwown";
break;
}
switch (severity) {
case zrtp_Info:
ortp_message("ZRTP INFO %s",submsg);
break;
case zrtp_Warning: /*!< A Warning message - security can be established */
ortp_warning("ZRTP %s",submsg);
break;
case zrtp_Severe:/*!< Severe error, security will not be established */
ortp_error("ZRTP SEVERE %s",submsg);
break;
case zrtp_ZrtpError:
ortp_error("ZRTP ERROR %s",submsg);
break;
default:
ortp_error("ZRTP UNKNOWN ERROR %s",submsg);
break;
}
if (subCode == zrtp_InfoSecureStateOn || subCode == zrtp_InfoSecureStateOff) {
OrtpEventData *eventData;
OrtpEvent *ev;
ev=ortp_event_new(ORTP_EVENT_ZRTP_ENCRYPTION_CHANGED);
eventData=ortp_event_get_data(ev);
eventData->info.zrtp_stream_encrypted=(subCode == zrtp_InfoSecureStateOn);
rtp_session_dispatch_event(user_data(ctx)->session, ev);
}
}
void rtp_session_rtp_parse(RtpSession *session, mblk_t *mp, uint32_t local_str_ts, struct sockaddr *addr, socklen_t addrlen)
{
int i;
int discarded;
int duplicate;
rtp_header_t *rtp;
int msgsize;
RtpStream *rtpstream=&session->rtp;
rtp_stats_t *stats=&rtpstream->stats;
msgsize=(int)(mp->b_wptr-mp->b_rptr);
if (msgsize<RTP_FIXED_HEADER_SIZE){
ortp_warning("Packet too small to be a rtp packet (%i)!",msgsize);
rtpstream->stats.bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
rtp=(rtp_header_t*)mp->b_rptr;
if (rtp->version!=2)
{
/* try to see if it is a STUN packet */
uint16_t stunlen=*((uint16_t*)(mp->b_rptr + sizeof(uint16_t)));
stunlen = ntohs(stunlen);
if (stunlen+20==mp->b_wptr-mp->b_rptr){
/* this looks like a stun packet */
if (session->eventqs!=NULL){
OrtpEvent *ev=ortp_event_new(ORTP_EVENT_STUN_PACKET_RECEIVED);
OrtpEventData *ed=ortp_event_get_data(ev);
ed->packet=mp;
memcpy(&ed->source_addr,addr,addrlen);
ed->source_addrlen=addrlen;
ed->info.socket_type = OrtpRTPSocket;
rtp_session_dispatch_event(session,ev);
return;
}
}
/* discard in two case: the packet is not stun OR nobody is interested by STUN (no eventqs) */
ortp_debug("Receiving rtp packet with version number !=2...discarded");
stats->bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
/* only count non-stun packets. */
ortp_global_stats.packet_recv++;
stats->packet_recv++;
ortp_global_stats.hw_recv+=msgsize;
stats->hw_recv+=msgsize;
session->rtp.hwrcv_since_last_SR++;
session->rtcp_xr_stats.rcv_since_last_stat_summary++;
/* convert all header data from network order to host order */
rtp->seq_number=ntohs(rtp->seq_number);
rtp->timestamp=ntohl(rtp->timestamp);
rtp->ssrc=ntohl(rtp->ssrc);
/* convert csrc if necessary */
if (rtp->cc*sizeof(uint32_t) > (uint32_t) (msgsize-RTP_FIXED_HEADER_SIZE)){
ortp_debug("Receiving too short rtp packet.");
stats->bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
#ifndef PERF
/* Write down the last RTP/RTCP packet reception time. */
ortp_gettimeofday(&session->last_recv_time, NULL);
#endif
for (i=0;i<rtp->cc;i++)
rtp->csrc[i]=ntohl(rtp->csrc[i]);
/*the goal of the following code is to lock on an incoming SSRC to avoid
receiving "mixed streams"*/
if (session->ssrc_set){
/*the ssrc is set, so we must check it */
if (session->rcv.ssrc!=rtp->ssrc){
if (session->inc_ssrc_candidate==rtp->ssrc){
session->inc_same_ssrc_count++;
}else{
session->inc_same_ssrc_count=0;
session->inc_ssrc_candidate=rtp->ssrc;
}
if (session->inc_same_ssrc_count>=session->rtp.ssrc_changed_thres){
/* store the sender rtp address to do symmetric RTP */
if (!session->use_connect){
if (session->rtp.gs.socket>0 && session->symmetric_rtp){
/* store the sender rtp address to do symmetric RTP */
memcpy(&session->rtp.gs.rem_addr,addr,addrlen);
session->rtp.gs.rem_addrlen=addrlen;
}
}
session->rtp.rcv_last_ts = rtp->timestamp;
session->rcv.ssrc=rtp->ssrc;
rtp_signal_table_emit(&session->on_ssrc_changed);
}else{
/*discard the packet*/
ortp_debug("Receiving packet with unknown ssrc.");
stats->bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
} else{
/* The SSRC change must not happen if we still receive
ssrc from the initial source. */
session->inc_same_ssrc_count=0;
}
}else{
session->ssrc_set=TRUE;
session->rcv.ssrc=rtp->ssrc;
if (!session->use_connect){
if (session->rtp.gs.socket>0 && session->symmetric_rtp){
/* store the sender rtp address to do symmetric RTP */
memcpy(&session->rtp.gs.rem_addr,addr,addrlen);
session->rtp.gs.rem_addrlen=addrlen;
}
}
}
/* update some statistics */
{
poly32_t *extseq=(poly32_t*)&rtpstream->hwrcv_extseq;
if (rtp->seq_number>extseq->split.lo){
extseq->split.lo=rtp->seq_number;
}else if (rtp->seq_number<200 && extseq->split.lo>((1<<16) - 200)){
/* this is a check for sequence number looping */
extseq->split.lo=rtp->seq_number;
extseq->split.hi++;
}
/* the first sequence number received should be initialized at the beginning
or at any resync, so that the first receiver reports contains valid loss rate*/
if (!(session->flags & RTP_SESSION_RECV_SEQ_INIT)){
rtp_session_set_flag(session, RTP_SESSION_RECV_SEQ_INIT);
rtpstream->hwrcv_seq_at_last_SR=rtp->seq_number-1;
session->rtcp_xr_stats.rcv_seq_at_last_stat_summary=rtp->seq_number-1;
}
if (stats->packet_recv==1){
session->rtcp_xr_stats.first_rcv_seq=extseq->one;
}
session->rtcp_xr_stats.last_rcv_seq=extseq->one;
}
/* check for possible telephone events */
if (rtp_profile_is_telephone_event(session->snd.profile, rtp->paytype)){
queue_packet(&session->rtp.tev_rq,session->rtp.max_rq_size,mp,rtp,&discarded,&duplicate);
stats->discarded+=discarded;
ortp_global_stats.discarded+=discarded;
stats->packet_dup_recv+=duplicate;
ortp_global_stats.packet_dup_recv+=duplicate;
session->rtcp_xr_stats.discarded_count += discarded;
session->rtcp_xr_stats.dup_since_last_stat_summary += duplicate;
return;
}
/* check for possible payload type change, in order to update accordingly our clock-rate dependant
parameters */
if (session->hw_recv_pt!=rtp->paytype){
rtp_session_update_payload_type(session,rtp->paytype);
}
/* Drop the packets while the RTP_SESSION_FLUSH flag is set. */
if (session->flags & RTP_SESSION_FLUSH) {
freemsg(mp);
return;
}
jitter_control_new_packet(&session->rtp.jittctl,rtp->timestamp,local_str_ts);
update_rtcp_xr_stat_summary(session, mp, local_str_ts);
if (session->flags & RTP_SESSION_FIRST_PACKET_DELIVERED) {
/* detect timestamp important jumps in the future, to workaround stupid rtp senders */
if (RTP_TIMESTAMP_IS_NEWER_THAN(rtp->timestamp,session->rtp.rcv_last_ts+session->rtp.ts_jump)){
ortp_warning("rtp_parse: timestamp jump in the future detected.");
rtp_signal_table_emit2(&session->on_timestamp_jump,&rtp->timestamp);
}
else if (RTP_TIMESTAMP_IS_STRICTLY_NEWER_THAN(session->rtp.rcv_last_ts,rtp->timestamp)
|| RTP_SEQ_IS_STRICTLY_GREATER_THAN(session->rtp.rcv_last_seq,rtp->seq_number)){
/* don't queue packets older than the last returned packet to the application, or whose sequence number
is behind the last packet returned to the application*/
/* Call timstamp jumb in case of
* large negative Ts jump or if ts is set to 0
*/
if ( RTP_TIMESTAMP_IS_STRICTLY_NEWER_THAN(session->rtp.rcv_last_ts, rtp->timestamp + session->rtp.ts_jump) ){
ortp_warning("rtp_parse: negative timestamp jump detected");
rtp_signal_table_emit2(&session->on_timestamp_jump, &rtp->timestamp);
}
ortp_debug("rtp_parse: discarding too old packet (ts=%i)",rtp->timestamp);
freemsg(mp);
stats->outoftime++;
ortp_global_stats.outoftime++;
session->rtcp_xr_stats.discarded_count++;
return;
}
}
if (queue_packet(&session->rtp.rq,session->rtp.max_rq_size,mp,rtp,&discarded,&duplicate))
jitter_control_update_size(&session->rtp.jittctl,&session->rtp.rq);
stats->discarded+=discarded;
ortp_global_stats.discarded+=discarded;
stats->packet_dup_recv+=duplicate;
ortp_global_stats.packet_dup_recv+=duplicate;
session->rtcp_xr_stats.discarded_count += discarded;
session->rtcp_xr_stats.dup_since_last_stat_summary += duplicate;
if ((discarded == 0) && (duplicate == 0)) {
session->rtcp_xr_stats.rcv_count++;
}
}
void rtp_session_rtp_parse(RtpSession *session, mblk_t *mp, uint32_t local_str_ts, struct sockaddr *addr, socklen_t addrlen)
{
int i;
rtp_header_t *rtp;
int msgsize;
RtpStream *rtpstream=&session->rtp;
rtp_stats_t *stats=&rtpstream->stats;
return_if_fail(mp!=NULL);
msgsize=msgdsize(mp);
if (msgsize<RTP_FIXED_HEADER_SIZE){
ortp_warning("Packet too small to be a rtp packet (%i)!",msgsize);
rtpstream->stats.bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
rtp=(rtp_header_t*)mp->b_rptr;
if (rtp->version!=2)
{
/* try to see if it is a STUN packet */
uint16_t stunlen=*((uint16_t*)(mp->b_rptr + sizeof(uint16_t)));
stunlen = ntohs(stunlen);
if (stunlen+20==mp->b_wptr-mp->b_rptr){
/* this looks like a stun packet */
if (session->eventqs!=NULL){
OrtpEvent *ev=ortp_event_new(ORTP_EVENT_STUN_PACKET_RECEIVED);
OrtpEventData *ed=ortp_event_get_data(ev);
ed->packet=mp;
ed->ep=rtp_endpoint_new(addr,addrlen);
rtp_session_dispatch_event(session,ev);
return;
}
}
freemsg(mp);
return;
}
/* only count non-stun packets. */
ortp_global_stats.packet_recv++;
stats->packet_recv++;
ortp_global_stats.hw_recv+=msgsize;
stats->hw_recv+=msgsize;
session->rtp.hwrcv_since_last_SR++;
if (rtp->version!=2)
{
/* discard*/
ortp_debug("Receiving rtp packet with version number !=2...discarded");
stats->bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
/* convert all header data from network order to host order */
rtp->seq_number=ntohs(rtp->seq_number);
rtp->timestamp=ntohl(rtp->timestamp);
rtp->ssrc=ntohl(rtp->ssrc);
/* convert csrc if necessary */
if (rtp->cc*sizeof(uint32_t) > (uint32_t) (msgsize-RTP_FIXED_HEADER_SIZE)){
ortp_debug("Receiving too short rtp packet.");
stats->bad++;
ortp_global_stats.bad++;
freemsg(mp);
return;
}
/* Write down the last RTP/RTCP packet reception time. */
gettimeofday(&session->last_recv_time, NULL);
for (i=0;i<rtp->cc;i++)
rtp->csrc[i]=ntohl(rtp->csrc[i]);
if (session->rcv.ssrc!=0)
{
/*the ssrc is set, so we must check it */
if (session->rcv.ssrc!=rtp->ssrc){
/*ortp_debug("rtp_parse: bad ssrc - %i",rtp->ssrc);*/
session->rcv.ssrc=rtp->ssrc;
rtp_signal_table_emit(&session->on_ssrc_changed);
}
}else session->rcv.ssrc=rtp->ssrc;
/* update some statistics */
{
poly32_t *extseq=(poly32_t*)&rtpstream->hwrcv_extseq;
if (rtp->seq_number>extseq->split.lo){
extseq->split.lo=rtp->seq_number;
}else if (rtp->seq_number<200 && extseq->split.lo>((1<<16) - 200)){
/* this is a check for sequence number looping */
extseq->split.lo=rtp->seq_number;
extseq->split.hi++;
}
}
/* check for possible telephone events */
if (rtp->paytype==session->rcv.telephone_events_pt){
split_and_queue(&session->rtp.tev_rq,session->rtp.max_rq_size,mp,rtp,&i);
stats->discarded+=i;
ortp_global_stats.discarded+=i;
return;
}
/* check for possible payload type change, in order to update accordingly our clock-rate dependant
parameters */
if (session->hw_recv_pt!=rtp->paytype){
rtp_session_update_payload_type(session,rtp->paytype);
}
if (session->flags & RTP_SESSION_FIRST_PACKET_DELIVERED) {
int32_t slide=0;
int32_t safe_delay=0;
jitter_control_new_packet(&session->rtp.jittctl,rtp->timestamp,local_str_ts,&slide,&safe_delay);
session->rtp.rcv_diff_ts=session->rtp.hwrcv_diff_ts + slide - safe_delay;
ortp_debug(" rcv_diff_ts=%i", session->rtp.rcv_diff_ts);
/* detect timestamp important jumps in the future, to workaround stupid rtp senders */
if (RTP_TIMESTAMP_IS_NEWER_THAN(rtp->timestamp,session->rtp.rcv_last_ts+session->rtp.ts_jump)){
ortp_debug("rtp_parse: timestamp jump ?");
rtp_signal_table_emit2(&session->on_timestamp_jump,(long)&rtp->timestamp);
}
else if (RTP_TIMESTAMP_IS_STRICTLY_NEWER_THAN(session->rtp.rcv_last_ts,rtp->timestamp)){
/* don't queue packets older than the last returned packet to the application*/
/* Call timstamp jumb in case of
* large negative Ts jump or if ts is set to 0
*/
if ( RTP_TIMESTAMP_IS_STRICTLY_NEWER_THAN(session->rtp.rcv_last_ts, rtp->timestamp + session->rtp.ts_jump) ){
ortp_warning("rtp_parse: negative timestamp jump");
rtp_signal_table_emit2(&session->on_timestamp_jump,
(long)&rtp->timestamp);
}
ortp_debug("rtp_parse: discarding too old packet (ts=%i)",rtp->timestamp);
freemsg(mp);
stats->outoftime++;
ortp_global_stats.outoftime++;
return;
}
}
split_and_queue(&session->rtp.rq,session->rtp.max_rq_size,mp,rtp,&i);
stats->discarded+=i;
ortp_global_stats.discarded+=i;
}