<div dir="ltr"><div class="gmail_default" style>+ycheng</div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jan 4, 2013 at 12:43 PM, Maciej Soltysiak <span dir="ltr"><<a href="mailto:maciej@soltysiak.com" target="_blank">maciej@soltysiak.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Oops, apologies if email was formatted weirdly...</blockquote><div><br></div><div style>The problem you described below is separate from the MIPS router crash one, right? BTW, we've only tested on x86_64 arch.</div>
<div style><br></div><div style>In addition to tcpdump, "netstat -s | grep -i fastopen" may be useful too.</div><div style><br></div><div style>Thanks,</div><div style><br></div><div style>Jerry (author of TFO server code)</div>
<div style><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5"><br><br><div class="gmail_quote">On Fri, Jan 4, 2013 at 9:42 PM, Maciej Soltysiak <span dir="ltr"><<a href="mailto:maciej@soltysiak.com" target="_blank">maciej@soltysiak.com</a>></span> wrote:<br>
<blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid" class="gmail_quote"><div>I am seeing something strange here, with polipo related to TFO but also DNS.</div>
<div> </div><div>When I just took 3.7.1-1 and set my windows 7 laptop to use gw.home.lan:8123 as http proxy it didn't work. What I observed was:</div>
<div>A) after quite a while polipo's response to browser was 504<font> Host <a href="http://www.osnews.com" target="_blank">www.osnews.com</a> lookup failed: Timeout</font></div><div>b) this error in ssh console: Host <a href="http://osnews.com" target="_blank">osnews.com</a> lookup failed: Timeout (131072)</div>
<div>c) Disabling TFO by adding option useTCPFastOpen 'false' to config 'polipo' 'general' works around the problem</div><div>d) Alternatively, you can keep TFO enabled in polipo but change option 'dnsUseGethostbyname' from 'reluctantly' to 'true' (!)</div>
<div> </div><div>This is very weird, because TFO is TCP and the DNS queries fired off by polipo are UDP:</div><div> </div><div><a href="mailto:root@OpenWrt:/tmp/log#" target="_blank">root@OpenWrt:/tmp/log#</a> tcpdump -n -v -vv -vvv -x -X -s 1500 -i lo</div>
<div>20:21:56.160245 IP (tos 0x0, ttl 64, id 50129, offset 0, flags [DF], proto UDP (17), length 60)<br> 127.0.0.1.47304 > 127.0.0.1.53: [bad udp cksum 0xfe3b -> 0xd17f!] 55396+ A? <a href="http://www.osnews.com/" target="_blank">www.osnews.com</a>. (32)<br>
0x0000: 4500 003c c3d1 4000 4011 78dd 7f00 0001 E..<<a href="mailto:..@.@.x" target="_blank">..@.@.x</a>.....<br> 0x0010: 7f00 0001 b8c8 0035 0028 fe3b d864 0100 .......5.(.;.d..<br> 0x0020: 0001 0000 0000 0000 0377 7777 066f 736e .........www.osn<br>
0x0030: 6577 7303 636f 6d00 0001 0001 ews.com.....<br>20:21:56.160319 IP (tos 0x0, ttl 64, id 50130, offset 0, flags [DF], proto UDP (17), length 60)<br> 127.0.0.1.47304 > 127.0.0.1.53: [bad udp cksum 0xfe3b -> 0xd164!] 55396+ AAAA? <a href="http://www.osnews.com/" target="_blank">www.osnews.com</a>. (32)<br>
0x0000: 4500 003c c3d2 4000 4011 78dc 7f00 0001 E..<<a href="mailto:..@.@.x" target="_blank">..@.@.x</a>.....<br> 0x0010: 7f00 0001 b8c8 0035 0028 fe3b d864 0100 .......5.(.;.d..<br> 0x0020: 0001 0000 0000 0000 0377 7777 066f 736e .........www.osn<br>
0x0030: 6577 7303 636f 6d00 001c 0001 ews.com.....<br>20:21:56.169942 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 123)<br> 127.0.0.1.53 > 127.0.0.1.47304: [bad udp cksum 0xfe7a -> 0x5f73!] 55396 q: A? <a href="http://www.osnews.com/" target="_blank">www.osnews.com</a>. 1/2/0 <a href="http://www.osnews.com/" target="_blank">www.osnews.com</a>. [29m3s] A 74.86.31.159 ns: <a href="http://osnews.com" target="_blank">osnews.com</a>. [29m3s] NS <a href="http://ns2.swelter.net" target="_blank">ns2.swelter.net</a>., <a href="http://osnews.com" target="_blank">osnews.com</a>. [29m3s] NS <a href="http://ns1.swelter.net" target="_blank">ns1.swelter.net</a>. (95)<br>
0x0000: 4500 007b 0000 4000 4011 3c70 7f00 0001 <a href="mailto:E..%7B..@.@.%3Cp" target="_blank">E..{..@.@.<p</a>....<br> 0x0010: 7f00 0001 0035 b8c8 0067 fe7a d864 8180 .....5...g.z.d..<br> 0x0020: 0001 0001 0002 0000 0377 7777 066f 736e .........www.osn<br>
0x0030: 6577 7303 636f 6d00 0001 0001 c00c 0001 ews.com.........<br> 0x0040: 0001 0000 06cf 0004 4a56 1f9f c010 0002 ........JV......<br> 0x0050: 0001 0000 06cf 0011 036e 7332 0773 7765 .........ns2.swe<br>
0x0060: 6c74 6572 036e 6574 00c0 1000 0200 0100 lter.net........<br> 0x0070: 0006 cf00 0603 6e73 31c0 40 ......ns1.@<br>20:21:56.173901 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 135)<br>
127.0.0.1.53 > 127.0.0.1.47304: [bad udp cksum 0xfe86 -> 0x8ecb!] 55396 q: AAAA? <a href="http://www.osnews.com/" target="_blank">www.osnews.com</a>. 1/2/0 <a href="http://www.osnews.com/" target="_blank">www.osnews.com</a>. [54m44s] AAAA 2607:f0d0:1002:62::3 ns: <a href="http://osnews.com" target="_blank">osnews.com</a>. [29m3s] NS <a href="http://ns1.swelter.net" target="_blank">ns1.swelter.net</a>., <a href="http://osnews.com" target="_blank">osnews.com</a>. [29m3s] NS <a href="http://ns2.swelter.net" target="_blank">ns2.swelter.net</a>. (107)<br>
0x0000: 4500 0087 0000 4000 4011 3c64 7f00 0001 <a href="mailto:E.....@.@.%3Cd" target="_blank">E.....@.@.<d</a>....<br> 0x0010: 7f00 0001 0035 b8c8 0073 fe86 d864 8180 .....5...s...d..<br> 0x0020: 0001 0001 0002 0000 0377 7777 066f 736e .........www.osn<br>
0x0030: 6577 7303 636f 6d00 001c 0001 c00c 001c ews.com.........<br> 0x0040: 0001 0000 0cd4 0010 2607 f0d0 1002 0062 ........&......b<br> 0x0050: 0000 0000 0000 0003 c010 0002 0001 0000 ................<br>
0x0060: 06cf 0011 036e 7331 0773 7765 6c74 6572 .....ns1.swelter<br> 0x0070: 036e 6574 00c0 1000 0200 0100 0006 cf00 .net............<br> 0x0080: 0603 6e73 32c0 4c ..ns2.L<br>
</div><div>This is the only DNS traffic I saw during the attempts. The tcpdumps have udp bad checksum but when I disabled TFO in polipo, the UDP where still bad checksum but they worked.</div><div> </div><div>Really weird.<br>
</div><div>p.s. UPNP still works for port forwarding negotiation as it did in 3.6.11-4</div><div>I still couldn't get the UPNP/SSDP broadcasts (udp to 239.255.255.250) to being forwarded between se00 and sw00/sw10. Last time it worked was ~3.3.8. I'm starting not to question why it doesn't work, I'm starting to wonder why it did work then ;-)</div>
<div> </div><div>Regards,</div><div>Maciej</div><div><div><div> </div><div class="gmail_quote">On Fri, Jan 4, 2013 at 6:33 PM, Dave Taht <span dir="ltr"><<a href="mailto:dave.taht@gmail.com" target="_blank">dave.taht@gmail.com</a>></span> wrote:<br>
<blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid" class="gmail_quote"><div>On Fri, Jan 4, 2013 at 9:27 AM, Eric Dumazet <<a href="mailto:edumazet@google.com" target="_blank">edumazet@google.com</a>> wrote:<br>
> Sorry, could you give us a copy of the panic stack trace ?<br><br></div>I will get a serial console up on a wndr3800 by sunday. (sorry, just<br>landed in california, am in disarray)<br><br>The latest dev build of cero for the wndr3800 and wndr3700v2 is at:<br>
<br><a href="http://snapon.lab.bufferbloat.net/~cero2/cerowrt/wndr/3.7.1-1/" target="_blank">http://snapon.lab.bufferbloat.net/~cero2/cerowrt/wndr/3.7.1-1/</a><br><div><div><br>--<br>Dave Täht<br><br>Fixing bufferbloat with cerowrt: <a href="http://www.teklibre.com/cerowrt/subscribe.html" target="_blank">http://www.teklibre.com/cerowrt/subscribe.html</a><br>
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