On Wed, Sep 23, 2015 at 1:30 PM, Neal Cardwell <ncardw...@google.com> wrote: > > On Wed, Sep 23, 2015 at 4:19 PM, Eric Dumazet <eric.duma...@gmail.com> wrote: > > From: Eric Dumazet <eduma...@google.com> > > > > RST packets sent on behalf of TCP connections with TS option (RFC 7323 > > TCP timestamps) have incorrect TS val (set to 0), but correct TS ecr. > > > > A > B: Flags [S], seq 0, win 65535, options [mss 1000,nop,nop,TS val 100 > > ecr 0], length 0 > > B > A: Flags [S.], seq 2444755794, ack 1, win 28960, options [mss > > 1460,nop,nop,TS val 7264344 ecr 100], length 0 > > A > B: Flags [.], ack 1, win 65535, options [nop,nop,TS val 110 ecr > > 7264344], length 0 > > > > B > A: Flags [R.], seq 1, ack 1, win 28960, options [nop,nop,TS val 0 ecr > > 110], length 0 > > > > We need to call skb_mstamp_get() to get proper TS val, > > derived from skb->skb_mstamp > > > > Note that RFC 1323 was advocating to not send TS option in RST segment, > > but RFC 7323 recommends the opposite : > > > > Once TSopt has been successfully negotiated, that is both <SYN> and > > <SYN,ACK> contain TSopt, the TSopt MUST be sent in every non-<RST> > > segment for the duration of the connection, and SHOULD be sent in an > > <RST> segment (see Section 5.2 for details) Nice comment. I think it's worth adding why we choose not to follow RFC7323 sec 5.2 recommendation on setting TSval to 0?
> > > > > Fixes: 7faee5c0d514 ("tcp: remove TCP_SKB_CB(skb)->when") > > Signed-off-by: Eric Dumazet <eduma...@google.com> > > --- > > Acked-by: Neal Cardwell <ncardw...@google.com> > > Thanks, Eric! > > neal -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html