On Wed, Mar 09, 2016 at 03:11:50PM -0800, Yuchung Cheng wrote:
> On Wed, Mar 9, 2016 at 10:43 AM, Martin KaFai Lau <ka...@fb.com> wrote:
> > diff --git a/include/net/tcp.h b/include/net/tcp.h
> > index e90db85..24557a8 100644
> > --- a/include/net/tcp.h
> > +++ b/include/net/tcp.h
> > @@ -1816,4 +1816,14 @@ static inline void skb_set_tcp_pure_ack(struct
> > sk_buff *skb)
> > skb->truesize = 2;
> > }
> >
> > +static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff
> > *skb)
> > +{
> > + u16 segs_in;
> > +
> > + segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
> > + tp->segs_in += segs_in;
> > + if (skb->len > tcp_hdrlen(skb))
> > + tp->data_segs_in += segs_in;
> > +}
> > +
> > #endif /* _TCP_H */
> > diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
> > index fdb286d..f583c85 100644
> > --- a/net/ipv4/tcp_fastopen.c
> > +++ b/net/ipv4/tcp_fastopen.c
> > @@ -131,6 +131,7 @@ static bool tcp_fastopen_cookie_gen(struct request_sock
> > *req,
> > void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb)
> > {
> > struct tcp_sock *tp = tcp_sk(sk);
> > + u16 segs_in;
> >
> > if (TCP_SKB_CB(skb)->end_seq == tp->rcv_nxt)
> > return;
> > @@ -154,6 +155,9 @@ void tcp_fastopen_add_skb(struct sock *sk, struct
> > sk_buff *skb)
> > * as we certainly are not changing upper 32bit value (0)
> > */
> > tp->bytes_received = skb->len;
> > + segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
> > + tp->segs_in = segs_in;
> > + tp->data_segs_in = segs_in;
> why not use the new tcp_segs_in() helper?
It is because
segs_in has been set to 1 by tcp_create_openreq_child(), so calling
tcp_segs_in() will have it double counted
and
tcphdr has been pulled from skb, so skb->len does not include tcp_hdrlen.
I will add some remark in this change.
