/* TCP Fast Open Cookie as stored in memory */ struct tcp_fastopen_cookie { s8 len; u8 val[TCP_FASTOPEN_COOKIE_MAX]; }; I wonder if 's8' really does what we want on all arches. We want to store a negative 8bit number, not an unsigned one... On Fri, Jan 4, 2013 at 7:02 PM, Ketan Kulkarni wrote: > Without TFO all worked fine. > The problem is when tfo server is on cero box. > I will try both ECN on on laptop and disabling ECN on cero with TFO on. > Will report the behavior seen. > > Thanks, > Ketan. > On Jan 5, 2013 7:50 AM, "Yuchung Cheng" wrote: > >> On Fri, Jan 4, 2013 at 5:59 PM, Ketan Kulkarni >> wrote: >> > Well, I was trying polipo server on cero box and httping from laptop. On >> > both the boxes I set 3 in tcp_fastopen. >> > >> > The panic is seen only when server is on cero box. >> > If I run server on my laptop and httping from cero all TFO connections >> are >> > successful. >> > So I doubt its the only problem is SYN+DATA. >> Just to confirm: you meant the problem is SYN/data processing on the >> server side? >> >> Maybe we hit some ECN / TFO bug. Some crash log would be great. Thanks >> for trying TFO! >> >> > >> > Unfortunately I don't have the serial cable right now, and logread or >> dmesg >> > didn't print any logs before the cero router restarted. >> > >> > Attached is the tcpdump capture on lo when client and server both run on >> > cero box. >> > HTH! >> > >> > If you (or anyone) can suggest more diagnostics, I will be glad to >> provide. >> > >> > On Jan 5, 2013 2:49 AM, "Jerry Chu" wrote: >> >> >> >> +ycheng >> >> >> >> >> >> On Fri, Jan 4, 2013 at 1:11 PM, Dave Taht wrote: >> >>> >> >>> Hmm. I would lean towards there being an issue with the new (freshly >> >>> ported forward to 3.7.1) unaligned checksum code for mips based on >> >>> what you say here. Or an offload... >> >>> >> >>> As for the 239.x multicast issue, hmm... separate issue entirely. >> >>> Probably... >> >>> >> >>> And then there's TFO. I note that in order to use it properly you need >> >>> to turn it on in proc. Last I remember that was >> >>> >> >>> echo 3 > /proc/sys/net/ipv4/tcp_fastopen >> >> >> >> >> >> Correct - to enable the normal use of TFO for both client and server. >> >> There are other flags for advanced usage: >> >> /* Bit Flags for sysctl_tcp_fastopen */ >> >> #define TFO_CLIENT_ENABLE 1 >> >> #define TFO_SERVER_ENABLE 2 >> >> #define TFO_CLIENT_NO_COOKIE 4 /* Send data-in-SYN w/o cookie */ >> >> >> >> /* Process SYN data but skip cookie validation */ >> >> #define TFO_SERVER_COOKIE_NOT_CHKED 0x100 >> >> /* Accept SYN data w/o any cookie option */ >> >> #define TFO_SERVER_COOKIE_NOT_REQD 0x200 >> >> >> >> /* Force enable TFO on all listeners, i.e., not requiring the >> >> * TCP_FASTOPEN socket option. SOCKOPT1/2 determine how to set >> max_qlen. >> >> */ >> >> #define TFO_SERVER_WO_SOCKOPT1 0x400 >> >> #define TFO_SERVER_WO_SOCKOPT2 0x800 >> >> /* Always create TFO child sockets on a TFO listener even when >> >> * cookie/data not present. (For testing purpose!) >> >> */ >> >> #define TFO_SERVER_ALWAYS 0x1000 >> >> >> >>> >> >>> However that's an old memory and there is this tcp_fastopen_key file I >> >>> don't know anything about yet (this is such bleeding edge stuff!) >> >>> >> >>> ... and with tcp_fastopen disabled things should still work right... >> >>> so I'm thinking something else is busted in the stack. >> >>> >> >>> I've also observed a dns slowdown in what I've been testing but hadn't >> >>> dug into packet dumps. (and was assuming, until now, it was due to me >> >>> fiddling with ULAs inside the network) Thanks for digging this deep! >> >>> >> >>> I never said this first attempt at 3.7 for cero was going to be >> >>> perfect, but we've entered a new age of subtle problems here. >> >>> >> >>> I strongly suggest nobody else try this dev build as a default gw, and >> >>> that the TFO folk ignore the noise for now. >> >> >> >> >> >> SG. >> >> >> >> Jerry >> >> >> >>> >> >>> >> >>> I just got a 3.7.1 box built on x86_64 so as to a/b some captures. >> >>> Regrettably I'm short on time through the weekend... >> >>> >> >>> On Fri, Jan 4, 2013 at 12:42 PM, Maciej Soltysiak < >> maciej@soltysiak.com> >> >>> wrote: >> >>> > I am seeing something strange here, with polipo related to TFO but >> also >> >>> > DNS. >> >>> > 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: >> >>> > A) after quite a while polipo's response to browser was 504 Host >> >>> > www.osnews.com lookup failed: Timeout >> >>> > b) this error in ssh console: Host osnews.com lookup failed: >> Timeout >> >>> > (131072) >> >>> > c) Disabling TFO by adding option useTCPFastOpen 'false' to config >> >>> > 'polipo' >> >>> > 'general' works around the problem >> >>> > d) Alternatively, you can keep TFO enabled in polipo but change >> option >> >>> > 'dnsUseGethostbyname' from 'reluctantly' to 'true' (!) >> >>> > This is very weird, because TFO is TCP and the DNS queries fired >> off by >> >>> > polipo are UDP: >> >>> > root@OpenWrt:/tmp/log# tcpdump -n -v -vv -vvv -x -X -s 1500 -i lo >> >>> > 20:21:56.160245 IP (tos 0x0, ttl 64, id 50129, offset 0, flags [DF], >> >>> > proto >> >>> > UDP (17), length 60) >> >>> > 127.0.0.1.47304 > 127.0.0.1.53: [bad udp cksum 0xfe3b -> 0xd17f!] >> >>> > 55396+ A? >> >>> > www.osnews.com. (32) >> >>> > 0x0000: 4500 003c c3d1 4000 4011 78dd 7f00 0001 E..<..@.@.x..... >> >>> > 0x0010: 7f00 0001 b8c8 0035 0028 fe3b d864 0100 .......5.(.;.d.. >> >>> > 0x0020: 0001 0000 0000 0000 0377 7777 066f 736e .........www.osn >> >>> > 0x0030: 6577 7303 636f 6d00 0001 0001 ews.com..... >> >>> > 20:21:56.160319 IP (tos 0x0, ttl 64, id 50130, offset 0, flags [DF], >> >>> > proto >> >>> > UDP (17), length 60) >> >>> > 127.0.0.1.47304 > 127.0.0.1.53: [bad udp cksum 0xfe3b -> 0xd164!] >> >>> > 55396+ >> >>> > AAAA? www.osnews.com. (32) >> >>> > 0x0000: 4500 003c c3d2 4000 4011 78dc 7f00 0001 E..<..@.@.x..... >> >>> > 0x0010: 7f00 0001 b8c8 0035 0028 fe3b d864 0100 .......5.(.;.d.. >> >>> > 0x0020: 0001 0000 0000 0000 0377 7777 066f 736e .........www.osn >> >>> > 0x0030: 6577 7303 636f 6d00 001c 0001 ews.com..... >> >>> > 20:21:56.169942 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], >> proto >> >>> > UDP >> >>> > (17), length 123) >> >>> > 127.0.0.1.53 > 127.0.0.1.47304: [bad udp cksum 0xfe7a -> 0x5f73!] >> 55396 >> >>> > q: >> >>> > A? www.osnews.com. 1/2/0 www.osnews.com. [29m3s] A 74.86.31.159 ns: >> >>> > osnews.com. [29m3s] NS ns2.swelter.net., osnews.com. [29m3s] NS >> >>> > ns1.swelter.net. (95) >> >>> > 0x0000: 4500 007b 0000 4000 4011 3c70 7f00 0001 E..{..@.@.> >>> > 0x0010: 7f00 0001 0035 b8c8 0067 fe7a d864 8180 .....5...g.z.d.. >> >>> > 0x0020: 0001 0001 0002 0000 0377 7777 066f 736e .........www.osn >> >>> > 0x0030: 6577 7303 636f 6d00 0001 0001 c00c 0001 ews.com......... >> >>> > 0x0040: 0001 0000 06cf 0004 4a56 1f9f c010 0002 ........JV...... >> >>> > 0x0050: 0001 0000 06cf 0011 036e 7332 0773 7765 .........ns2.swe >> >>> > 0x0060: 6c74 6572 036e 6574 00c0 1000 0200 0100 lter.net........ >> >>> > 0x0070: 0006 cf00 0603 6e73 31c0 40 ......ns1.@ >> >>> > 20:21:56.173901 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], >> proto >> >>> > UDP >> >>> > (17), length 135) >> >>> > 127.0.0.1.53 > 127.0.0.1.47304: [bad udp cksum 0xfe86 -> 0x8ecb!] >> 55396 >> >>> > q: >> >>> > AAAA? www.osnews.com. 1/2/0 www.osnews.com. [54m44s] AAAA >> >>> > 2607:f0d0:1002:62::3 ns: osnews.com. [29m3s] NS ns1.swelter.net., >> >>> > osnews.com. [29m3s] NS ns2.swelter.net. (107) >> >>> > 0x0000: 4500 0087 0000 4000 4011 3c64 7f00 0001 E.....@.@.> >>> > 0x0010: 7f00 0001 0035 b8c8 0073 fe86 d864 8180 .....5...s...d.. >> >>> > 0x0020: 0001 0001 0002 0000 0377 7777 066f 736e .........www.osn >> >>> > 0x0030: 6577 7303 636f 6d00 001c 0001 c00c 001c ews.com......... >> >>> > 0x0040: 0001 0000 0cd4 0010 2607 f0d0 1002 0062 ........&......b >> >>> > 0x0050: 0000 0000 0000 0003 c010 0002 0001 0000 ................ >> >>> > 0x0060: 06cf 0011 036e 7331 0773 7765 6c74 6572 .....ns1.swelter >> >>> > 0x0070: 036e 6574 00c0 1000 0200 0100 0006 cf00 .net............ >> >>> > 0x0080: 0603 6e73 32c0 4c ..ns2.L >> >>> > 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. >> >>> > Really weird. >> >>> > p.s. UPNP still works for port forwarding negotiation as it did in >> >>> > 3.6.11-4 >> >>> > 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 ;-) >> >>> > Regards, >> >>> > Maciej >> >>> > On Fri, Jan 4, 2013 at 6:33 PM, Dave Taht >> wrote: >> >>> >> >> >>> >> On Fri, Jan 4, 2013 at 9:27 AM, Eric Dumazet >> >>> >> wrote: >> >>> >> > Sorry, could you give us a copy of the panic stack trace ? >> >>> >> >> >>> >> I will get a serial console up on a wndr3800 by sunday. (sorry, >> just >> >>> >> landed in california, am in disarray) >> >>> >> >> >>> >> The latest dev build of cero for the wndr3800 and wndr3700v2 is at: >> >>> >> >> >>> >> http://snapon.lab.bufferbloat.net/~cero2/cerowrt/wndr/3.7.1-1/ >> >>> >> >> >>> >> -- >> >>> >> Dave Täht >> >>> >> >> >>> >> Fixing bufferbloat with cerowrt: >> >>> >> http://www.teklibre.com/cerowrt/subscribe.html >> >>> >> _______________________________________________ >> >>> >> Cerowrt-devel mailing list >> >>> >> Cerowrt-devel@lists.bufferbloat.net >> >>> >> https://lists.bufferbloat.net/listinfo/cerowrt-devel >> >>> > >> >>> > >> >>> >> >>> >> >>> >> >>> -- >> >>> Dave Täht >> >>> >> >>> Fixing bufferbloat with cerowrt: >> >>> http://www.teklibre.com/cerowrt/subscribe.html >> >> >> >> >> > >> >