[lwip-users] [lwip] CLOSE_WAIT

[Peter Bosmans]

Hoi,

Questions about the uIP.

Any idea's why the linux server (192.168.0.1) doesn't close the connectcion
(I use the telnet port on in uIP (192.168.0.128) to echo the incoming data)
Here's the tcpdump result.

/* Open connection */
23:03:47.185848 192.168.0.1.1050 > 192.168.0.128.telnet: S
260906917:260906917(0) win 32512 <mss 256,sackOK,timestamp 4476626
0,nop,wscale 0> (DF)
                         4500 003c 8b98 4000 4006 2d52 c0a8 0001
                         c0a8 0080 041a 0017 0f8d 1fa5 0000 0000
                         a002 7f00 c96f 0000 0204 0100 0402 080a
                         0044 4ed2 0000 0000 0103 0300

/* ack incoming connection */
23:03:47.325848 192.168.0.128.telnet > 192.168.0.1.1050: S 0:0(0) ack
260906918 win 68 <mss 68>
                         4500 002c 8b98 0000 8006 2d62 c0a8 0080
                         c0a8 0001 0017 041a 0000 0000 0f8d 1fa6
                         6012 0044 e80c 0000 0204 0044

/* Connection established */
23:03:47.325848 192.168.0.1.1050 > 192.168.0.128.telnet: . ack 1 win 32512
(DF)
                         4500 0028 8b9b 4000 4006 2d63 c0a8 0001
                         c0a8 0080 041a 0017 0f8d 1fa6 0000 0001
                         5010 7f00 7b9d 0000

/* Send data : aaa\n */
23:03:53.335848 192.168.0.1.1050 > 192.168.0.128.telnet: P 1:5(4) ack 1 win
32708 (DF)
                         4500 002c 8bc0 4000 4006 2d3a c0a8 0001
                         c0a8 0080 041a 0017 0f8d 1fa6 0000 0001
                         5018 7fc4 b861 0000 6161 610a

/* reply with ack and with the received data */
23:03:53.455848 192.168.0.128.telnet > 192.168.0.1.1050: . 1:5(4) ack 5 win
68
                         4500 002c 8bc0 0000 8006 2d3a c0a8 0080
                         c0a8 0001 0017 041a 0000 0001 0f8d 1faa
                         5010 0044 37e6 0000 6161 610a

/* Ack from linux */
23:03:53.455848 192.168.0.1.1050 > 192.168.0.128.telnet: . ack 5 win 32708
(DF)
                         4500 0028 8bc8 4000 4006 2d36 c0a8 0001
                         c0a8 0080 041a 0017 0f8d 1faa 0000 0005
                         5010 7fc4 7ad1 0000

/* Close the connection from uIP */
23:03:53.565848 192.168.0.128.telnet > 192.168.0.1.1050: F 5:5(0) ack 5 win
68
                         4500 0028 8bc8 0000 8006 2d36 c0a8 0080
                         c0a8 0001 0017 041a 0000 0005 0f8d 1faa
                         5011 0044 fa50 0000

/* Ack from linux, why doesn't is the FIN flag set here.
 Is it because the ack-counter isn't incremented or .... ????? */
23:03:53.575848 192.168.0.1.1050 > 192.168.0.128.telnet: . ack 6 win 32708
(DF)
                         4500 0028 8bcf 4000 4006 2d2f c0a8 0001
                         c0a8 0080 041a 0017 0f8d 1faa 0000 0006
                         5010 7fc4 7ad0 0000

Netstat give me for this connection :
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 petbox.be:1050          192.168.0.128:telnet
CLOSE_WAIT

Any idea's ??

Thanks in advance,

Peter

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