PeerConnection.h

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/*******************************************
PeerConnection internal include file
*******************************************/
#ifndef __KINESIS_VIDEO_WEBRTC_CLIENT_PEERCONNECTION_PEERCONNECTION__
#define __KINESIS_VIDEO_WEBRTC_CLIENT_PEERCONNECTION_PEERCONNECTION__
 
#pragma once
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define LOCAL_ICE_UFRAG_LEN 4
#define LOCAL_ICE_PWD_LEN   24
#define LOCAL_CNAME_LEN     16
 
// https://tools.ietf.org/html/rfc5245#section-15.4
#define MAX_ICE_UFRAG_LEN 256
#define MAX_ICE_PWD_LEN   256
 
#define PEER_FRAME_BUFFER_SIZE_INCREMENT_FACTOR 1.5
 
// A non-comprehensive list of valid JSON characters
#define VALID_CHAR_SET_FOR_JSON "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/"
 
#define ICE_CANDIDATE_JSON_TEMPLATE (PCHAR) "{\"candidate\":\"candidate:%s\",\"sdpMid\":\"0\",\"sdpMLineIndex\":0}"
 
#define MAX_ICE_CANDIDATE_JSON_LEN (MAX_SDP_ATTRIBUTE_VALUE_LENGTH + SIZEOF(ICE_CANDIDATE_JSON_TEMPLATE) + 1)
 
#define CODEC_HASH_TABLE_BUCKET_COUNT  50
#define CODEC_HASH_TABLE_BUCKET_LENGTH 2
#define RTX_HASH_TABLE_BUCKET_COUNT    50
#define RTX_HASH_TABLE_BUCKET_LENGTH   2
#define TWCC_HASH_TABLE_BUCKET_COUNT   100
#define TWCC_HASH_TABLE_BUCKET_LENGTH  2
 
#define DATA_CHANNEL_HASH_TABLE_BUCKET_COUNT  200
#define DATA_CHANNEL_HASH_TABLE_BUCKET_LENGTH 2
 
// Environment variable to display SDPs
#define DEBUG_LOG_SDP ((PCHAR) "DEBUG_LOG_SDP")
 
#define MAX_ACCESS_THREADS_WEBRTC_CLIENT_CONTEXT 50
 
typedef enum {
    RTC_RTX_CODEC_H264_PROFILE_42E01F_LEVEL_ASYMMETRY_ALLOWED_PACKETIZATION_MODE = 1,
    RTC_RTX_CODEC_VP8 = 2,
    RTC_RTX_CODEC_H265 = 3,
} RTX_CODEC;

typedef struct {
    UINT64 localTimeKvs;  
    UINT64 remoteTimeKvs; 
    UINT32 packetSize;
} TwccRtpPacketInfo, *PTwccRtpPacketInfo;
 
typedef struct {
    PHashTable pTwccRtpPktInfosHashTable; // Hash table of [seqNum, PTwccPacket]
    UINT16 firstSeqNumInRollingWindow;    // To monitor the last deleted packet in the rolling window
    UINT16 lastReportedSeqNum;            // To monitor the last packet's seqNum in the TWCC response
    UINT16 prevReportedBaseSeqNum;        // To monitor the base seqNum in the TWCC response
    DOUBLE smoothedSlope;                 // EMA-smoothed trendline slope (hundreds-of-nanos units)
    DOUBLE lastQueueDelay;                // Last computed queue delay (hundreds-of-nanos units)
} TwccManager, *PTwccManager;
 
typedef struct {
    UINT64 peerConnectionCreationTime;
    UINT64 dtlsSessionSetupTime;
    UINT64 iceHolePunchingTime;
    UINT64 closePeerConnectionTime;
    UINT64 freePeerConnectionTime;
} KvsPeerConnectionDiagnostics, *PKvsPeerConnectionDiagnostics;
 
typedef struct {
    RtcPeerConnection peerConnection;
    // UINT32 padding makes transportWideSequenceNumber 64bit aligned
    // we put atomics at the top of structs because customers application could set the packing to 0
    // in which case any atomic operations would result in bus errors if there is a misalignment
    // for more see https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/pull/987#discussion_r534432907
    UINT32 padding;
    volatile SIZE_T transportWideSequenceNumber;
 
    PIceAgent pIceAgent;
    PDtlsSession pDtlsSession;
    // Atomic: written by setRemoteDescription (signaling thread) and read when the DTLS
    // handshake starts (ICE timer / threadpool thread). A re-negotiation setRemoteDescription
    // can overlap those reads, so plain BOOL access would race.
    volatile ATOMIC_BOOL dtlsIsServer;
 
    MUTEX pSrtpSessionLock;
    PSrtpSession pSrtpSession;
 
    PSctpSession pSctpSession;
 
    PSessionDescription pRemoteSessionDescription;
    PDoubleList pTransceivers;
    PDoubleList pFakeTransceivers;
    PDoubleList pAnswerTransceivers;
 
    volatile ATOMIC_BOOL sctpIsEnabled;
 
    CHAR localIceUfrag[LOCAL_ICE_UFRAG_LEN + 1];
    CHAR localIcePwd[LOCAL_ICE_PWD_LEN + 1];
 
    CHAR remoteIceUfrag[MAX_ICE_UFRAG_LEN + 1];
    CHAR remoteIcePwd[MAX_ICE_PWD_LEN + 1];
 
    CHAR localCNAME[LOCAL_CNAME_LEN + 1];
 
    CHAR remoteCertificateFingerprint[CERTIFICATE_FINGERPRINT_LENGTH + 1];
 
    MUTEX peerConnectionObjLock;
    MUTEX dataChannelsLock; // guards pDataChannels (app threads create channels while the SCTP thread uses the table)
 
    // If the local session description is an SDP offer.
    // (TRUE = viewer mode, FALSE = master mode)
    BOOL isOffer;
 
    TIMER_QUEUE_HANDLE timerQueueHandle;
 
    // Codecs that we support and their payloadTypes
    // When offering we generate values starting from 96
    // When answering this is populated from the remote offer
    PHashTable pCodecTable;
 
    // Payload types that we use to retransmit data
    // When answering this is populated from the remote offer
    PHashTable pRtxTable;
 
    // DataChannels keyed by streamId
    PHashTable pDataChannels;
 
    UINT64 onDataChannelCustomData;
    RtcOnDataChannel onDataChannel;
 
    UINT64 onIceCandidateCustomData;
    RtcOnIceCandidate onIceCandidate;
 
    UINT64 onConnectionStateChangeCustomData;
    RtcOnConnectionStateChange onConnectionStateChange;
    RTC_PEER_CONNECTION_STATE connectionState;
 
    UINT16 MTU;
 
    NullableBool canTrickleIce;
 
    // congestion control
    // https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01
    UINT16 twccExtId;
    BOOL remoteTwccOfferedPerMedia[MAX_SDP_SESSION_MEDIA_COUNT]; // tracks which remote m-lines offered TWCC extmap
    MUTEX twccLock;
    PTwccManager pTwccManager;
    RtcOnSenderBandwidthEstimation onSenderBandwidthEstimation;
    UINT64 onSenderBandwidthEstimationCustomData;
 
    // TWCC trendline callback (configurable estimator)
    RtcOnTwccFeedbackReceived onTwccFeedbackReceived;
    UINT64 onTwccFeedbackReceivedCustomData;
 
    // Bandwidth controller callback (application-side)
    RtcOnPeerCongestionFeedback onPeerCongestionFeedback;
    UINT64 onPeerCongestionFeedbackCustomData;
 
    UINT64 iceConnectingStartTime;
    KvsPeerConnectionDiagnostics peerConnectionDiagnostics;
} KvsPeerConnection, *PKvsPeerConnection;
 
typedef struct {
    UINT32 currentDataChannelId;
    PKvsPeerConnection pKvsPeerConnection;
    PHashTable unkeyedDataChannels;
    BOOL negotiatedPass; 
} AllocateSctpSortDataChannelsData, *PAllocateSctpSortDataChannelsData;
 
typedef struct {
    CHAR hostname[MAX_ICE_CONFIG_URI_LEN + 1];
    DualKvsIpAddresses kvsIpAddresses;
    BOOL isIpInitialized;
    UINT64 startTime;
    UINT64 stunDnsResolutionTime;
    UINT64 expirationDuration;
    STATUS status;
} StunIpAddrContext, *PStunIpAddrContext;
 
// Declare the structure of the Singleton
// Members of the singleton are responsible for their own sync mechanisms.
typedef struct {
    PStunIpAddrContext pStunIpAddrCtx;
    volatile ATOMIC_BOOL isContextInitialized;
    volatile SIZE_T contextRefCnt;
    MUTEX stunCtxlock;
} WebRtcClientContext, *PWebRtcClientContext;
 
STATUS onFrameReadyFunc(UINT64, UINT16, UINT16, UINT32);
STATUS onFrameDroppedFunc(UINT64, UINT16, UINT16, UINT32);
VOID onSctpSessionOutboundPacket(UINT64, PBYTE, UINT32);
VOID onSctpSessionDataChannelMessage(UINT64, UINT32, BOOL, PBYTE, UINT32);
STATUS onSctpSessionDataChannelOpen(UINT64, UINT32, PBYTE, UINT32, PRtcDataChannelInit);
VOID onSctpSessionDataChannelAck(UINT64, UINT32);
 
STATUS sendPacketToRtpReceiver(PKvsPeerConnection, PBYTE, UINT32);
STATUS changePeerConnectionState(PKvsPeerConnection, RTC_PEER_CONNECTION_STATE);
STATUS twccManagerOnPacketSent(PKvsPeerConnection, PRtpPacket);
UINT32 parseExtId(PCHAR);
 
// visible for testing only
VOID onIceConnectionStateChange(UINT64, UINT64);
 
// STUN server address pre-resolution (initKvsWebRtc) handed to new peer connections
PWebRtcClientContext getWebRtcClientInstance();
VOID releaseHoldOnInstance(PWebRtcClientContext);
STATUS createWebRtcClientInstance();
STATUS cleanupWebRtcClientInstance();
STATUS onSetStunServerIp(UINT64, PCHAR, PDualKvsIpAddresses);
 
#ifdef __cplusplus
}
#endif
#endif /* __KINESIS_VIDEO_WEBRTC_CLIENT_PEERCONNECTION_PEERCONNECTION__ */