Interpretation of websocket protocol -rfc6455

1.webscoket
2. handshake handshake(open, close)
3. send data ：3 Methods
4. To break off ： Protocol layer +tcp close()
 

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1.webscoket

visit ：ws://192.168.232.128:8888 
            agreement Address port
How to judge is websocket：Upgrade:websocket
  from Sec-WebSocket-Key To Sec-WebSocket-Accpet:

//1.request:
//Upgrade:websocket    Distinguish the agreement 
//Sec-WebSocket-Key:   identity   base64

//2.response:
//Sec-WebSocket-Accpet:

// Why add public GUID RFC4122 On . Role of filling 
//1. from Sec-WebSocket-Key  To Sec-WebSocket-Accpet:
// step ：1.key Character splicing    key=Sec-WebSocket-Key+GUID
//     2. Hash           sha=SHA-1(key)
//     3.base64 The coding   base64(sha);

2. handshake handshake(open close)
     Why shake hands ？ There has been a TCP 了 .
    Multiple protocols coexist
    compatible http webserver
      Verify whether the identities of both parties are legal
   
3. send data
3.1 Message header definition ：
   

According to the data length , The format of the header ：
General data length : <126 when ：6 individual
                       =126 when ：8 individual
                       ==127 when ：14 individual

 

 6：

 8： More 2,3 Two bytes
14：

 3.2 The longest number of data sent ：73bits

3.3 Plaintext or ciphertext ：
 mask Is it 1.

If it's ciphertext , The calculation is as follows ：

 

 3.4 Read 3 Ways of planting ：

 

4. To break off ：
Why disconnect ？ Because a lot of close_wait
Method ： application layer websocket-->fin;// Protocol layer
                       tcp close();              //tcp4 Second wave