问题
Assuming that the client and server send packets according to the order of sequence as shown in the figure, the client does not know FIN has arrived.
It sends “hello again” to the server, the server responds to the client with an RST and the RST has arrived. Then if the client is blocking on a read, why it return 0 due to the FIN instead of -1 because the RST? In the 《Effective TCP/IP programming》, it tells us that the core will return ECONNRESET error.
My operating system is Ubuntu 12.10. Is it related with the operating system? Please tell me some TCP’s details on this implementation. Thanks in advance.
来源：https://stackoverflow.com/questions/22503882/what-does-the-read-call-return-on-earth-if-there-are-already-both-fin-and-rst-in