[lwip-users] Detection remote closed TCP connection

[Muhamad Ikhwan Ismail]

 

Hi guys,

I have checked the threads and the last one dated in 2003 and hence rather outdated. I have a telnet server which accepts connection(in an infinite loop) and
in case the connection is accepted, it process the I/O using the socket in a nested loop.

while(1){
int s = accept(); //blocks untill the connection is accepted

for(;;){
       //runs IO
    }
}

I have a slight problem when the remote host closes the connection. I would want to include a connection status check and jump back
to accept() if the connection is closed from the remote host. Is there anyway to do this ? It also has to be non-blocking and can be lwip specific.

So far I have heard few suggestions from the old thread :

1. read/write 0 bytes. //blocks ?
2. Use of MSG_PEEK read (in 2003 was not yet implemented ).

I hope to hear your suggestions on the matter and thanks a lot in advance.

M Ikhwan Ismail
STO/CPK
ABB STOTZ KONTAKT GmbH
Heidelberg

Platform : PowerPC MPC852T
OS : SMX RTOS with runtime system.

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