ICE学习笔记 -- RFC 5245
4)STUN Message Type
- request
- success response
- failure response
- indication
1、A向S发出Allocate Request，请求S在自己的IP地址上为A分配一个端口。
5. 开源实现 https://github.com/NATTools
ICELIB_INSTANCE *m_iceInst;
static ICELIB_Result OnConnectivityChecksComplete(void *pUserData, uint32_t userValue1, bool isControlling, bool iceFailed);
static ICELIB_Result OnOutgoingBindingRequest(void *pUserData, const struct sockaddr *destination,
const struct sockaddr *source, uint32_t transport, uint32_t userValue1, uint32_t userValue2,
uint32_t componentId, bool useRelay, const char *pUfragPair, const char *pPasswd,
uint32_t peerPriority, bool useCandidate, bool iceControlling, bool iceControlled,
uint64_t tieBreaker, StunMsgId transactionId, const char *szFingerPrint);
static ICELIB_Result OutgoingBindingResponse(void *pUserData, uint32_t userValue1,
uint32_t userValue2, uint32_t componentId, const struct sockaddr *source,
const struct sockaddr *destination, const struct sockaddr *MappedAddress,
uint16_t errorResponse, StunMsgId transactionId, bool useRelay, const char *pUfragPair,
const char *pPasswd);
/*
static ICELIB_Result OnSendKeepAlive(void *pUserData, uint32_t userValue1, uint32_t userValue2,
uint32_t mediaIdx);
*/
6. wilson同学的分享记录
ICE
1. 什么是NAT？（网络地址转换）
2. NAT带来的问题(连通性问题，并没有定义或推荐公网或私网IP地址影射的方法，及互相通迅的问题，完全由应用自己解决)
3. STUN解决的问题（解决两个NAT之后设备的连通）
4. 源地址、目标地址、源端口，目标端口，协议 5个元素
5. NAT暴力猜测方法，两边各猜64个连接，连通的概率就很大了
6. ALG，根据SDP里的信息，帮你分配端口，路由器要支持SDP,且SDP不能被加密
7. Connectivity check,可以做很多并行的尝试,间隔一定的delay，按优先级发包
8. STUN包做了扩展。PRIORITY, USE-CANDIDATE, ICE-CONTROLLED, and ICE-CONTROLLING
9. Nominate的过程：（Nomination 一直在做，priority每过100毫秒加100，达到1000，即可以conclude.）
收到包以后，好几个都通了，就需要选择一个。Aggressive/Regular nomination, Aggressive nomination已经淘汰，因为协议有bug。
Aggressive 本来是想更快的建立连接，后来大家发现Regular完全可以做到同样的快, Early media。
Regular Nominate过程，发的STUN包有两种包，USE-CANDIDATE=0（Nominate前）， USE-CANDIDATE=1(Nominate后)
两个人，不能两个人都Nominate, 要选择一个主动，一个被动。SDP里面有个属性，叫ICE-CONTROLLING（主动）, ICE-CONTROLLED（被动)。
被动的一方收到response，看到USE-CANDIDATE=1，就知道了选择好了，以后用这个transport来通讯。
角色的选择，第一个STUN包的里时候，里面有个tie-breaking，是一个64bit的随机数，谁的大谁就做CONTROLLING，另一个做CONTROLLED
10. LITE实现(当做为服务器时，有公网IP的情况下，申明我是LITE，就不需要connectivity check，由client来check)
firefox 对LITE支持的不太好，chrome还可以。
11. Restart/Reconnect
12. Keep live（定时，client发一个包，server回一个包，做有效性检查）
13. Conclude:（为什么Aggressive Nominate不需要了，是因为有Early media）
Early media就是说，有一个transport连通以后，就可以发送一些数据回去,所以只要你发，对方肯定能收的到.
因为这时候还没有Conclue，一旦conclue这后，非nominate的transport会被关闭。
Conclude，是为了保证RTP的transport是symmetric的，即发过去和发过来的transport是同一个。
14. ICE, RTP, DTLS是复用在同一个transport上的。
15. AddMediaStream，一个SDP里面有多个Media(Audio/Video),要建多条连接，一个MediaStream里面有两个component(RTP1 /RTCP 2).
一个session里面有多个MediaStream(Audio/Video/Sharing)。
我们ICE session里面的实现，三个是分开的，一个Media就用了一个Session，是觉得放在一个session里，可以做优化的不多。
Audio/Video/Sharing各有一个ICEConnector，各用一个transport。
16. 优先级 0123456 Nattool里fundation有bug（不同的IP用相同的fundation）.
17. OnICEComplete会来两回，第一次是Early meida（最早的连通的一个transport）, 第二次是Conclude. bUpdate=0 bUpdate=1。
ICE
//
//----- ICE configuration data
//
typedef struct {
unsigned int tickIntervalMS;
unsigned int keepAliveIntervalS;
unsigned int maxCheckListPairs;
bool aggressiveNomination;
bool iceLite;
ICELIB_logLevel logLevel;
} ICELIB_CONFIGURATION;
//
//----- ICE instance data
//
typedef struct tag_ICELIB_INSTANCE {
ICELIB_STATE iceState;
ICELIB_CONFIGURATION iceConfiguration;
ICELIB_CALLBACKS callbacks;
ICE_MEDIA localIceMedia;
ICE_MEDIA remoteIceMedia;
bool iceControlling;
bool iceControlled;
bool iceSupportVerified;
uint64_t tieBreaker;
ICELIB_STREAM_CONTROLLER streamControllers[ ICE_MAX_MEDIALINES];
unsigned int numberOfMediaStreams;
unsigned int roundRobinStreamControllerIndex;
uint32_t tickCount;
uint32_t keepAliveTickCount;
} ICELIB_INSTANCE;
/*!
* ICE single candidate
*
* From draft-ietf-mmusic-ice-18:
*
* foundation = 1*32 ice-char
* componentid = 1*5 digit (0..65535)
* priority = 1*10 digit (0..2147483647)
* connectionAddr = address including port
* relAddr = host addres when sending relayed candidates (Optional, used for debugging)
*/
typedef struct {
char foundation[ ICE_MAX_FOUNDATION_LENGTH];
uint32_t componentid;
uint32_t priority;
struct sockaddr_storage connectionAddr;
ICE_CANDIDATE_TYPE type;
struct sockaddr_storage relAddr;
uint32_t userValue1;
uint32_t userValue2;
uint32_t transport;
char fingerprint[ICE_MAX_FINGERPRINT];
} ICE_CANDIDATE;
typedef struct {
uint32_t componentId;
struct sockaddr_storage connectionAddr;
ICE_CANDIDATE_TYPE type;
} ICE_REMOTE_CANDIDATE;
typedef struct {
ICE_REMOTE_CANDIDATE remoteCandidate[ICE_MAX_COMPONENTS];
uint32_t numberOfComponents;
} ICE_REMOTE_CANDIDATES;
/*!
* ICE candidates for a single media stream
*/
typedef struct {
char ufrag [ ICE_MAX_UFRAG_LENGTH];
char passwd [ ICE_MAX_PASSWD_LENGTH];
ICE_CANDIDATE candidate[ ICE_MAX_CANDIDATES];
uint32_t numberOfCandidates;
ICE_TURN_STATE turnState;
uint32_t userValue1;
uint32_t userValue2;
struct sockaddr_storage defaultAddr;
ICE_CANDIDATE_TYPE defaultCandType;
} ICE_MEDIA_STREAM;
ICELIB_INSTANCE
ICELIB_Constructor
ICELIB_Destructor
ICELIB_Start
ICELIB_Stop
ICELIB_ReStart
ICELIB_Tick
ICELIB_setCallbackLog
ICELIB_addLocalMediaStream
ICELIB_setLocalMediaStream
ICELIB_getLocalMediaStream
ICELIB_addRemoteMediaStream
ICELIB_getRemoteMediaStream
ICELIB_setCallbackConnecitivityChecksComplete
ICELIB_setCallbackOutgoingBindingRequest
ICELIB_setCallbackOutgoingBindingResponse
ICELIB_setCallbackKeepAlive
ICELIB_doKeepAlive
ICELIB_addLocalCandidate
ICELIB_getActiveCandidate
ICELIB_getActiveRemoteCandidates
ICELIB_incomingBindingRequest
ICELIB_isIceComplete
ICELIB_isRunning
ICELIB_incomingBindingResponse
ICELIB_getRemoteComponentId
ICELIB_generateTransactionId
ICELIBTYPES_ICE_CANDIDATE_TYPE_toString
Frozen已经废弃不用了
ICELIB_setCallbackConnecitivityChecksComplete(m_iceInst, OnConnectivityChecksComplete, this);
ICELIB_setCallbackOutgoingBindingRequest(m_iceInst, OnOutgoingBindingRequest, this);
ICELIB_setCallbackOutgoingBindingResponse(m_iceInst, OutgoingBindingResponse, this);
static ICELIB_Result OnConnectivityChecksComplete(void *pUserData, uint32_t userValue1, bool isControlling, bool iceFailed);
//onicecomplete, aReason
static ICELIB_Result OnOutgoingBindingRequest(void *pUserData, const struct sockaddr *destination,
const struct sockaddr *source, uint32_t transport, uint32_t userValue1, uint32_t userValue2,
uint32_t componentId, bool useRelay, const char *pUfragPair, const char *pPasswd,
uint32_t peerPriority, bool useCandidate, bool iceControlling, bool iceControlled,
uint64_t tieBreaker, StunMsgId transactionId, const char *szFingerPrint);
//start connectivity checking, a Request --->> a check.
static ICELIB_Result OutgoingBindingResponse(void *pUserData, uint32_t userValue1,
uint32_t userValue2, uint32_t componentId, const struct sockaddr *source,
const struct sockaddr *destination, const struct sockaddr *MappedAddress,
uint16_t errorResponse, StunMsgId transactionId, bool useRelay, const char *pUfragPair,
const char *pPasswd);
//有一个response回来可以做early media
conclude at last, select a transport
/*
static ICELIB_Result OnSendKeepAlive(void *pUserData, uint32_t userValue1, uint32_t userValue2,
uint32_t mediaIdx);
*/
