IO::Socket TCP stack problems on OSX
[email protected] (Stuart Gall)
| Newsgroups | perl.macosx |
|---|---|
| Message-ID | <[email protected]> |
Hello, I have written a script using IO::Socket::INET to read and write data to modbus devices. This is running on OSX V 10.4.11 I have the latest IO::Socket Library from CPAN. Using perl 5.8.6 from OSX and I built perl 5.10 which has the same issue The script will work for a few loops, maybe doing 100 or so modbus read/writes Then the sockets are closed for no apparent reason. I did a tcpdump, what seams to be happening is that when an error occurs in the TCP packet, the OSX end gets stuck in a loop requesting and re requesting the packet. Until eventually the other end sends RST and force-ably closes the socket. Then everything goes bad, if I just close the problem socket then one by one the other sockets close. (This is confirmed with IO::Select) When I get this block I have to close all sockets and reopen them to clear it. I copied the same script to another OSX machine running 10.4.11 and I have the exact same problem. I copied the script to a machine running Mandrivia 2009 and it works just fine! Any Ideas what might be going on ? TCPDUMP (192.168.251.3 is the OSX machine) 10:17:19.508241 IP 192.168.251.3.52312 > 192.168.251.102.502: P 160:172(12) ack 90 win 65535 <nop,nop,timestamp 1360281049 65303> 10:17:19.514522 IP 192.168.251.102.502 > 192.168.251.3.52312: P 90:101 (11) ack 172 win 5669 <timestamp 65461 1360281049,nop,nop> 10:17:19.514544 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281049 65461> That was a request and reply acknowledged - Normal 10:17:19.747871 IP 192.168.251.3.52312 > 192.168.251.102.502: P 172:187(15) ack 101 win 65535 <nop,nop,timestamp 1360281049 65461> Request 10:17:19.752164 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 163 1360281049,nop,nop> Reply 10:17:19.752183 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281050 65461> Rejected 10:17:20.501290 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 912 1360281050,nop,nop> Resent 10:17:20.501355 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281051 65461> Rejected 10:17:20.750835 IP 192.168.251.3.52312 > 192.168.251.102.502: P 172:187(15) ack 101 win 65535 <nop,nop,timestamp 1360281051 65461> Resend request (even though it was acknowledged) Is that legal ?? 10:17:20.762936 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 1174 1360281051,nop,nop> Accept 10:17:21.929985 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 2341 1360281051,nop,nop> Reply Again 10:17:21.930046 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281054 65461> Rejected 10:17:21.931308 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 2342 1360281054,nop,nop> Resent 10:17:21.931324 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281054 65461> Rejected 10:17:21.932624 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 2343 1360281054,nop,nop> ? And so on 10:17:22.751058 IP 192.168.251.3.52312 > 192.168.251.102.502: P 172:187(15) ack 101 win 65535 <nop,nop,timestamp 1360281055 65461> 10:17:22.759845 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 3171 1360281055,nop,nop> 10:17:24.778286 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 5189 1360281055,nop,nop> 10:17:24.778318 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281060 65461> 10:17:24.779660 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 5190 1360281060,nop,nop> 10:17:26.751479 IP 192.168.251.3.52312 > 192.168.251.102.502: P 172:187(15) ack 101 win 65535 <nop,nop,timestamp 1360281063 65461> 10:17:26.758087 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 7169 1360281063,nop,nop> 10:17:30.470519 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 10881 1360281063,nop,nop> 10:17:30.470583 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281071 65461> 10:17:30.471828 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 10882 1360281071,nop,nop> 10:17:34.752192 IP 192.168.251.3.52312 > 192.168.251.102.502: P 172:187(15) ack 101 win 65535 <nop,nop,timestamp 1360281079 65461> 10:17:34.754071 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 15164 1360281079,nop,nop> 10:17:37.576828 IP 192.168.251.102.502 > 192.168.251.3.52312: P 101:113(12) ack 187 win 5654 <timestamp 17987 1360281079,nop,nop> 10:17:37.576875 IP 192.168.251.3.52312 > 192.168.251.102.502: . ack 101 win 65535 <nop,nop,timestamp 1360281085 65461> 10:17:37.578139 IP 192.168.251.102.502 > 192.168.251.3.52312: . ack 187 win 5654 <timestamp 17988 1360281085,nop,nop> 10:17:50.754009 IP 192.168.251.3.52312 > 192.168.251.102.502: P 172:187(15) ack 101 win 65535 <nop,nop,timestamp 1360281111 65461> 10:17:50.761068 IP 192.168.251.102.502 > 192.168.251.3.52312: R 249188453:249188453(0) win 0 Now I thing 192.168.251.102 gets fed up and boots us off TIA Stuart.