Message ID | 1273611036.2512.18.camel@edumazet-laptop |
---|---|
State | Superseded, archived |
Delegated to: | David Miller |
Headers | show |
Le mardi 11 mai 2010 à 22:50 +0200, Eric Dumazet a écrit : > Le mardi 11 mai 2010 à 04:08 +0000, Bijay Singh a écrit : > > Hi Eric, > > > > I guess that makes me the enviable one. So I am keen to test out this feature completely, as long as I know what to do as a next step, directions, patches. > > > > Thanks > > > I believe third problem comes from commit 4957faad > (TCPCT part 1g: Responder Cookie => Initiator), from William Allen > Simpson. > > When a SYN-ACK packet is built (in tcp_synack_options()), > it specifically forbids a TIMESTAMP option to be included if SACK is > also selected : > > doing_ts &= !ireq->sack_ok; > > Problem is this mask is done on a local variable. socket is still marked > as being timestamp enabled. > > > Later, when we build tcp options for data packets, we _include_ a > timestamp, while our SYNACK didnt mention the option. > > So the following trafic can happen (and fails) : > > 18:38:29.041966 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [S], seq 4014064674, win 8860, options [mss 4430,sackOK,TS val 519041 ecr 0,nop,wscale 7,nop,nop,md5can't check - 9b44126367effcf3247fcbf6da76b24d], length 0 > 18:38:29.042072 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [S.], seq 586328714, ack 4014064675, win 5792, options [nop,nop,md5can't check - badd847799ded46f39642c341cc7e92b,mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 > 18:38:29.042093 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [.], ack 1, win 70, options [nop,nop,md5can't check - 3994ef6987df02a592963fba04c5d313], length 0 > 18:38:29.043217 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [.], seq 1:1441, ack 1, win 70, options [nop,nop,md5can't check - 8399f7ccab3a6b8c5a3027ed58bba314], length 1440 > 18:38:29.043226 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [P.], seq 1441:2501, ack 1, win 70, options [nop,nop,md5can't check - 701ebf65b1894a6bed4cefbf7a56596a], length 1060 > 18:38:29.043374 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], ack 1441, win 68, options [nop,nop,md5can't check - 1badb315ba436ab59bff5b37daa871be,nop,nop,TS val 113051377 ecr 519041], length 0 > 18:38:29.043383 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], ack 2501, win 91, options [nop,nop,md5can't check - 120564dcb99f822f3b70910282a6ed9d,nop,nop,TS val 113051377 ecr 519041], length 0 > 18:38:29.043673 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113051377 ecr 519041], length 1428 > 18:38:29.043681 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [P.], seq 1429:2500, ack 2501, win 91, options [nop,nop,md5can't check - 7a910cd5ff357bf0e2c8d3489aafaa86,nop,nop,TS val 113051377 ecr 519041], length 1071 > 18:38:32.037786 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113051677 ecr 519041], length 1428 > 18:38:38.037708 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113052277 ecr 519041], length 1428 > 18:38:50.037524 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113053477 ecr 519041], length 1428 > > > Could you try following patch ? > > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index 5db3a2c..0be21cd 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -668,7 +668,7 @@ static unsigned tcp_synack_options(struct sock *sk, > u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ? > xvp->cookie_plus : > 0; > - bool doing_ts = ireq->tstamp_ok; > + bool doing_ts; > > #ifdef CONFIG_TCP_MD5SIG > *md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req); > @@ -681,11 +681,12 @@ static unsigned tcp_synack_options(struct sock *sk, > * rather than TS in order to fit in better with old, > * buggy kernels, but that was deemed to be unnecessary. > */ > - doing_ts &= !ireq->sack_ok; > + ireq->tstamp_ok &= !ireq->sack_ok; > } > #else > *md5 = NULL; > #endif > + doing_ts = ireq->tstamp_ok; > > /* We always send an MSS option. */ > opts->mss = mss; > > > > Bijay, had you tested this patch by any chance ? Thanks -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 17-May-2010, at 2:18 AM, Eric Dumazet wrote: > Le mardi 11 mai 2010 à 22:50 +0200, Eric Dumazet a écrit : >> Le mardi 11 mai 2010 à 04:08 +0000, Bijay Singh a écrit : >>> Hi Eric, >>> >>> I guess that makes me the enviable one. So I am keen to test out this feature completely, as long as I know what to do as a next step, directions, patches. >>> >>> Thanks >> >> >> I believe third problem comes from commit 4957faad >> (TCPCT part 1g: Responder Cookie => Initiator), from William Allen >> Simpson. >> >> When a SYN-ACK packet is built (in tcp_synack_options()), >> it specifically forbids a TIMESTAMP option to be included if SACK is >> also selected : >> >> doing_ts &= !ireq->sack_ok; >> >> Problem is this mask is done on a local variable. socket is still marked >> as being timestamp enabled. >> >> >> Later, when we build tcp options for data packets, we _include_ a >> timestamp, while our SYNACK didnt mention the option. >> >> So the following trafic can happen (and fails) : >> >> 18:38:29.041966 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [S], seq 4014064674, win 8860, options [mss 4430,sackOK,TS val 519041 ecr 0,nop,wscale 7,nop,nop,md5can't check - 9b44126367effcf3247fcbf6da76b24d], length 0 >> 18:38:29.042072 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [S.], seq 586328714, ack 4014064675, win 5792, options [nop,nop,md5can't check - badd847799ded46f39642c341cc7e92b,mss 1460,nop,nop,sackOK,nop,wscale 7], length 0 >> 18:38:29.042093 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [.], ack 1, win 70, options [nop,nop,md5can't check - 3994ef6987df02a592963fba04c5d313], length 0 >> 18:38:29.043217 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [.], seq 1:1441, ack 1, win 70, options [nop,nop,md5can't check - 8399f7ccab3a6b8c5a3027ed58bba314], length 1440 >> 18:38:29.043226 IP 192.168.0.33.58906 > 192.168.0.56.22226: Flags [P.], seq 1441:2501, ack 1, win 70, options [nop,nop,md5can't check - 701ebf65b1894a6bed4cefbf7a56596a], length 1060 >> 18:38:29.043374 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], ack 1441, win 68, options [nop,nop,md5can't check - 1badb315ba436ab59bff5b37daa871be,nop,nop,TS val 113051377 ecr 519041], length 0 >> 18:38:29.043383 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], ack 2501, win 91, options [nop,nop,md5can't check - 120564dcb99f822f3b70910282a6ed9d,nop,nop,TS val 113051377 ecr 519041], length 0 >> 18:38:29.043673 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113051377 ecr 519041], length 1428 >> 18:38:29.043681 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [P.], seq 1429:2500, ack 2501, win 91, options [nop,nop,md5can't check - 7a910cd5ff357bf0e2c8d3489aafaa86,nop,nop,TS val 113051377 ecr 519041], length 1071 >> 18:38:32.037786 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113051677 ecr 519041], length 1428 >> 18:38:38.037708 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113052277 ecr 519041], length 1428 >> 18:38:50.037524 IP 192.168.0.56.22226 > 192.168.0.33.58906: Flags [.], seq 1:1429, ack 2501, win 91, options [nop,nop,md5can't check - fe5dfb438065373b52ba85bf800876a8,nop,nop,TS val 113053477 ecr 519041], length 1428 >> >> >> Could you try following patch ? >> >> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c >> index 5db3a2c..0be21cd 100644 >> --- a/net/ipv4/tcp_output.c >> +++ b/net/ipv4/tcp_output.c >> @@ -668,7 +668,7 @@ static unsigned tcp_synack_options(struct sock *sk, >> u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ? >> xvp->cookie_plus : >> 0; >> - bool doing_ts = ireq->tstamp_ok; >> + bool doing_ts; >> >> #ifdef CONFIG_TCP_MD5SIG >> *md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req); >> @@ -681,11 +681,12 @@ static unsigned tcp_synack_options(struct sock *sk, >> * rather than TS in order to fit in better with old, >> * buggy kernels, but that was deemed to be unnecessary. >> */ >> - doing_ts &= !ireq->sack_ok; >> + ireq->tstamp_ok &= !ireq->sack_ok; >> } >> #else >> *md5 = NULL; >> #endif >> + doing_ts = ireq->tstamp_ok; >> >> /* We always send an MSS option. */ >> opts->mss = mss; >> >> >> >> > > Bijay, had you tested this patch by any chance ? > I am on quite an old kernel 2.6.27 and could not apply your patches. Then i moved on to the kernel 2.6.32.11 however since then I have not been able to bring up my card, this is something i need to fix before i can test you fix. Working on that. > Thanks > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 5db3a2c..0be21cd 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -668,7 +668,7 @@ static unsigned tcp_synack_options(struct sock *sk, u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ? xvp->cookie_plus : 0; - bool doing_ts = ireq->tstamp_ok; + bool doing_ts; #ifdef CONFIG_TCP_MD5SIG *md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req); @@ -681,11 +681,12 @@ static unsigned tcp_synack_options(struct sock *sk, * rather than TS in order to fit in better with old, * buggy kernels, but that was deemed to be unnecessary. */ - doing_ts &= !ireq->sack_ok; + ireq->tstamp_ok &= !ireq->sack_ok; } #else *md5 = NULL; #endif + doing_ts = ireq->tstamp_ok; /* We always send an MSS option. */ opts->mss = mss;