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Date: Thu, 07 Feb 2008 20:24:06 +0100 From: Eric Dumazet <dada1@...mosbay.com> To: Marcin Koziej <marcinkoziej@...pl> CC: linux-kernel@...r.kernel.org, netdev@...r.kernel.org Subject: Re: Bug? Kernels 2.6.2x drops TCP packets over wireless (independentof card used) Marcin Koziej a écrit : >>> I have problem with wireless network connectivity; >>> TCP connections hang and timeout before all data is read. >>> >>> Problem description: >>> I am connected to the network via hotspot wifi router: >>> ath0 IEEE 802.11g ESSID:"hotspot" Nickname:"" >>> Mode:Managed Frequency:2.462 GHz Access Point: 00:60:B3:6C:A1:2E >>> Bit Rate:11 Mb/s Tx-Power:17 dBm Sensitivity=1/1 >>> Retry:off RTS thr:off Fragment thr:off >>> Power Management:off >>> Link Quality=19/70 Signal level=-77 dBm Noise level=-96 dBm >>> Rx invalid nwid:43882 Rx invalid crypt:0 Rx invalid frag:0 >>> Tx excessive retries:0 Invalid misc:0 Missed beacon:0 >>> >>> ICMP and UDP protocols seem to work (provided by 0% packet loss >>> ping to router (and internet servers), and a working DNS resolver) >>> However, when I try to connect to a TCP service, for example FTP or HTTP, the >>> connection is made, request >>> sent but truncated answer (or no answer) ever read back. >>> >>> For example: >>> # ftp ftp.icm.edu.pl >>> Connected to ftp.icm.edu.pl (193.219.28.140). >>> 220- >>> (hangs) >>> >>> The packet dump is: >>> 23:56:08.807674 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: S >>> 980196671:980196671(0) win 5840 <mss 1460,sackOK,timestamp 1971553 >>> 0,nop,wscale 5> see here wscale = 5, so win = 186880 >>> 0x0000: 4500 003c 885e 4000 4006 124c c0a8 0102 E..<.^@.@....... >>> 0x0010: c1db 1c8c cac5 0015 3a6c 9d3f 0000 0000 ........:l.?.... >>> 0x0020: a002 16d0 d91a 0000 0204 05b4 0402 080a ................ >>> 0x0030: 001e 1561 0000 0000 0103 0305 ...a........ >>> 23:56:08.821639 IP sunsite2.icm.edu.pl.ftp > 192.168.1.2.51909: S >>> 2723526584:2723526584(0) ack 980196672 win 5792 <mss 1460,sackOK,timestamp >>> 983901832 1971553,nop,wscale 7> >>> 0x0000: 4500 003c 0000 4000 3c06 9eaa c1db 1c8c E..<..@.<....... >>> 0x0010: c0a8 0102 0015 cac5 a255 b7b8 3a6c 9d40 .........U..:l.@ >>> 0x0020: a012 16a0 1dfc 0000 0204 05b4 0402 080a ................ >>> 0x0030: 3aa5 2688 001e 1561 0103 0307 :.&....a.... >>> 23:56:08.821685 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: . ack 1 win 183 >>> <nop,nop,timestamp 1971567 983901832> >>> 0x0000: 4500 0034 885f 4000 4006 1253 c0a8 0102 E..4._@.@....... >>> 0x0010: c1db 1c8c cac5 0015 3a6c 9d40 a255 b7b9 ........:l.@.... >>> 0x0020: 8010 00b7 62a3 0000 0101 080a 001e 156f ....b..........o >>> 0x0030: 3aa5 2688 :.&. >>> 23:56:08.842801 IP sunsite2.icm.edu.pl.ftp > 192.168.1.2.51909: P 1:7(6) ack 1 >>> win 46 <nop,nop,timestamp 983901837 1971567> >>> 0x0000: 4510 003a 9135 4000 3c06 0d67 c1db 1c8c E..:.5@.<..g.... >>> 0x0010: c0a8 0102 0015 cac5 a255 b7b9 3a6c 9d40 .........U..:l.@ >>> 0x0020: 8018 002e f3af 0000 0101 080a 3aa5 268d ............:.&. >>> 0x0030: 001e 156f 3232 302d 0d0a ...o220-.. >>> 23:56:08.843069 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: . ack 7 win 183 >>> <nop,nop,timestamp 1971588 983901837> here, win = 183 is probably not correctly understood by remote peer (as 5856) >>> 0x0000: 4510 0034 8860 4000 4006 1242 c0a8 0102 E..4.`@.@....... >>> 0x0010: c1db 1c8c cac5 0015 3a6c 9d40 a255 b7bf ........:l.@.... >>> 0x0020: 8010 00b7 6283 0000 0101 080a 001e 1584 ....b........... >>> 0x0030: 3aa5 268d :.&. >>> 23:56:31.920327 IP 192.168.1.2.51909 > sunsite2.icm.edu.pl.ftp: F 1:1(0) ack 7 >>> win 183 <nop,nop,timestamp 1994676 983901837> >>> 0x0000: 4510 0034 8861 4000 4006 1241 c0a8 0102 E..4.a@.@....... >>> 0x0010: c1db 1c8c cac5 0015 3a6c 9d40 a255 b7bf ........:l.@.... >>> 0x0020: 8011 00b7 0852 0000 0101 080a 001e 6fb4 .....R........o. >>> 0x0030: 3aa5 268d :.&. >>> 23:56:31.935145 IP sunsite2.icm.edu.pl.ftp > 192.168.1.2.51909: . ack 2 win 46 >>> <nop,nop,timestamp 983907613 1994676> >>> 0x0000: 4510 0034 913d 4000 3c06 0d65 c1db 1c8c E..4.=@.<..e.... >>> 0x0010: c0a8 0102 0015 cac5 a255 b8e5 3a6c 9d41 .........U..:l.A >>> 0x0020: 8010 002e f124 0000 0101 080a 3aa5 3d1d .....$......:.=. >>> 0x0030: 001e 6fb4 ..o. >>> >>> Other machines work with the router fine. >>> >>> How can I solve this problem? >>> I tried to look for some relevand info with athdebug, but i'm not sure what to >>> look for. >>> Can You help me? >>> >>> System: >>> I am using Atheros Communications, Inc. AR5212 802.11abg NIC PCMCIA card. >>> Computer is Acer Aspire 1520. >>> >>> I use vanilla kernel: >>> Linux 2.6.23 #1 Sat Jan 12 12:07:39 CET 2008 i686 AMD Athlon(tm) 64 Processor >>> 3700+ AuthenticAMD GNU/Linux >>> and madwifi driver ath_pci 0.9.4.5 (0.9.3.3) >>> kernel options: irqpoll (without irqpoll system doesn't detect pcmcia cards). >>> >>> Device detection: >>> ath_hal: module license 'Proprietary' taints kernel. >>> ath_hal: 0.9.18.0 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413) >>> ath_pci: 0.9.4.5 (0.9.3.3) >>> ath_rate_sample: 1.2 (0.9.3.3) >>> wifi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps >>> wifi0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps >>> 36Mbps 48Mbps 54Mbps >>> wifi0: turboG rates: 6Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps >>> wifi0: H/W encryption support: WEP AES AES_CCM TKIP >>> wifi0: mac 5.9 phy 4.3 radio 4.6 >>> wifi0: Use hw queue 1 for WME_AC_BE traffic >>> wifi0: Use hw queue 0 for WME_AC_BK traffic >>> wifi0: Use hw queue 2 for WME_AC_VI traffic >>> wifi0: Use hw queue 3 for WME_AC_VO traffic >>> wifi0: Use hw queue 8 for CAB traffic >>> wifi0: Use hw queue 9 for beacons >>> wifi0: Atheros 5212: mem=0x34000000, irq=11 >>> >>> On the same irq are: >>> ehci_hcd:usb1 >>> eth0 >>> uhci_hcd:usb4 >>> wifi%d >>> yenta >>> > > Eric Dumazet <dada1@...mosbay.com> ----------------------------------------- >> Very strange, as the tcpdump you gave shows that the remote peer only >> sent "220-\r\n" >> >> This was ACKed, and then nothing but timeout. We can conclude remote >> peer is *very* slow or a firewall is blocking trafic after 6 bytes sent :) >> >> Could you give a tcpdump for the same destination, on 2.6.19 this time ? > > Here goes, this happens after running: > ftp sunsite.icm.edu.pl > The ftp session is successful > > > ---------------------------------------------------- > tcpdump -i ath0 tcp and port 21 -X -s 300 -vv > tcpdump: listening on ath0, link-type EN10MB (Ethernet), capture size 300 bytes > 18:09:48.435612 IP (tos 0x0, ttl 64, id 6423, offset 0, flags [DF], proto: TCP (6), length: 60) sabayonx86.local.41649 > sunsite2.icm.edu.pl.ftp: S, cksum 0xe759 (correct), 1749015234:1749015234(0) win 5840 <mss 1460,sackOK,timestamp 1885141 0,nop,wscale ²2> wscale 2 here (instead of 5 on your non working case) So win = 23360 > 0x0000: 4500 003c 1917 4000 4006 8184 c0a8 0111 E..<..@.@....... > 0x0010: c1db 1c8c a2b1 0015 683f dac2 0000 0000 ........h?...... > 0x0020: a002 16d0 e759 0000 0204 05b4 0402 080a .....Y.......... > 0x0030: 001c c3d5 0000 0000 0103 0302 ............ > 18:09:48.449755 IP (tos 0x0, ttl 60, id 0, offset 0, flags [DF], proto: TCP (6), length: 60) sunsite2.icm.edu.pl.ftp > sabayonx86.local.41649: S, cksum 0xc97a (correct), 1528170639:1528170639(0) ack 1749015235 win 5792 <mss 1460,sackOK,timestamp 536320604 1885141,nop,wscale 7> > 0x0000: 4500 003c 0000 4000 3c06 9e9b c1db 1c8c E..<..@.<....... > 0x0010: c0a8 0111 0015 a2b1 5b16 088f 683f dac3 ........[...h?.. > 0x0020: a012 16a0 c97a 0000 0204 05b4 0402 080a .....z.......... > 0x0030: 1ff7 9a5c 001c c3d5 0103 0307 ...\........ > 18:09:48.449827 IP (tos 0x0, ttl 64, id 6424, offset 0, flags [DF], proto: TCP (6), length: 52) sabayonx86.local.41649 > sunsite2.icm.edu.pl.ftp: ., cksum 0x0925 (correct), 1:1(0) ack 1 win 1460 <nop,nop,timestamp 1885155 536320604> > 0x0000: 4500 0034 1918 4000 4006 818b c0a8 0111 E..4..@.@....... > 0x0010: c1db 1c8c a2b1 0015 683f dac3 5b16 0890 ........h?..[... > 0x0020: 8010 05b4 0925 0000 0101 080a 001c c3e3 .....%.......... > 0x0030: 1ff7 9a5c ...\ > 18:09:48.485234 IP (tos 0x10, ttl 60, id 37583, offset 0, flags [DF], proto: TCP (6), length: 58) sunsite2.icm.edu.pl.ftp > sabayonx86.local.41649: P, cksum 0x9f2a (correct), 1:7(6) ack 1 win 46 <nop,nop,timestamp 536320613 1885155> > 0x0000: 4510 003a 92cf 4000 3c06 0bbe c1db 1c8c E..:..@.<....... > 0x0010: c0a8 0111 0015 a2b1 5b16 0890 683f dac3 ........[...h?.. > 0x0020: 8018 002e 9f2a 0000 0101 080a 1ff7 9a65 .....*.........e > 0x0030: 001c c3e3 3232 302d 0d0a ....220-.. > 18:09:48.485337 IP (tos 0x10, ttl 64, id 6425, offset 0, flags [DF], proto: TCP (6), length: 52) sabayonx86.local.41649 > sunsite2.icm.edu.pl.ftp: ., cksum 0x08f2 (correct), 1:1(0) ack 7 win 1460 <nop,nop,timestamp 1885191 536320613> this win=1460 is correctly taken by remote peer as 5840 (wscale=2) > 0x0000: 4510 0034 1919 4000 4006 817a c0a8 0111 E..4..@.@....... > 0x0010: c1db 1c8c a2b1 0015 683f dac3 5b16 0896 ........h?..[... > 0x0020: 8010 05b4 08f2 0000 0101 080a 001c c407 ................ > 0x0030: 1ff7 9a65 ...e Typical window scaling problem here... (well, for previous traces, with wscaling of 5, since with wscale 2 it seems to work), you probably have a buggy router or something... http://lwn.net/Articles/92727/ Try : # echo 0 >/proc/sys/net/ipv4/tcp_window_scaling And retry to connect to this ftp server You could alternativly play with /proc/sys/net/ipv4/tcp_rmem # echo "4096 8192 50000" >/proc/sys/net/ipv4/tcp_rmem > 18:09:48.500421 IP (tos 0x10, ttl 60, id 37584, offset 0, flags [DF], proto: TCP (6), length: 191) sunsite2.icm.edu.pl.ftp > sabayonx86.local.41649: P, cksum 0xc74e (correct), 7:146(139) ack 1 win 46 <nop,nop,timestamp 536320616 1885191> > 0x0000: 4510 00bf 92d0 4000 3c06 0b38 c1db 1c8c E.....@.<..8.... > 0x0010: c0a8 0111 0015 a2b1 5b16 0896 683f dac3 ........[...h?.. > 0x0020: 8018 002e c74e 0000 0101 080a 1ff7 9a68 .....N.........h > 0x0030: 001c c407 3232 302d 2020 2020 2020 2020 ....220-........ > 0x0040: 2020 2020 4654 5020 6e61 2053 756e 5349 ....FTP.na.SunSI > 0x0050: 5445 2028 3620 5442 206f 7072 6f67 7261 TE.(6.TB.oprogra > 0x0060: 6d6f 7761 6e69 6129 2e0d 0a32 3230 2d20 mowania)...220-. > 0x0070: 2020 2020 5577 6167 693a 2073 756e 7369 ....Uwagi:.sunsi > 0x0080: 7465 4069 636d 2e65 6475 2e70 6c20 286f te@....edu.pl.(o > 0x0090: 6470 6f77 6961 6461 6d79 206e 6120 7773 dpowiadamy.na.ws > 0x00a0: 7a79 7374 6b69 6520 646f 742e 2053 756e zystkie.dot..Sun > 0x00b0: 5349 5445 2761 290d 0a32 3230 2d0d 0a SITE'a)..220-.. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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