On Mon, Jan 23, 2017 at 10:59 AM, Wei Wang <tracyw...@gmail.com> wrote:
>
> From: Wei Wang <wei...@google.com>
>
> Refactor the cookie check logic in tcp_send_syn_data() into a function.
> This function will be called else where in later changes.
>
> Signed-off-by: Wei Wang <wei...@google.com>
> ---
Acked-by: Yuchung Cheng <ych...@google.com>
> include/net/tcp.h | 2 ++
> net/ipv4/tcp_fastopen.c | 21 +++++++++++++++++++++
> net/ipv4/tcp_output.c | 16 ++--------------
> 3 files changed, 25 insertions(+), 14 deletions(-)
>
> diff --git a/include/net/tcp.h b/include/net/tcp.h
> index c55d65f74f7f..de67541d7adf 100644
> --- a/include/net/tcp.h
> +++ b/include/net/tcp.h
> @@ -1493,6 +1493,8 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct
> sk_buff *skb,
> struct tcp_fastopen_cookie *foc,
> struct dst_entry *dst);
> void tcp_fastopen_init_key_once(bool publish);
> +bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss,
> + struct tcp_fastopen_cookie *cookie);
> #define TCP_FASTOPEN_KEY_LENGTH 16
>
> /* Fastopen key context */
> diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
> index f51919535ca7..f90e09e1ff4c 100644
> --- a/net/ipv4/tcp_fastopen.c
> +++ b/net/ipv4/tcp_fastopen.c
> @@ -325,3 +325,24 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct
> sk_buff *skb,
> *foc = valid_foc;
> return NULL;
> }
> +
> +bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss,
> + struct tcp_fastopen_cookie *cookie)
> +{
> + unsigned long last_syn_loss = 0;
> + int syn_loss = 0;
> +
> + tcp_fastopen_cache_get(sk, mss, cookie, &syn_loss, &last_syn_loss);
> +
> + /* Recurring FO SYN losses: no cookie or data in SYN */
> + if (syn_loss > 1 &&
> + time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {
> + cookie->len = -1;
> + return false;
> + }
> + if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) {
> + cookie->len = -1;
> + return true;
> + }
> + return cookie->len > 0;
> +}
> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
> index 9a1a1494b9dd..671c69535671 100644
> --- a/net/ipv4/tcp_output.c
> +++ b/net/ipv4/tcp_output.c
> @@ -3267,23 +3267,11 @@ static int tcp_send_syn_data(struct sock *sk, struct
> sk_buff *syn)
> {
> struct tcp_sock *tp = tcp_sk(sk);
> struct tcp_fastopen_request *fo = tp->fastopen_req;
> - int syn_loss = 0, space, err = 0;
> - unsigned long last_syn_loss = 0;
> + int space, err = 0;
> struct sk_buff *syn_data;
>
> tp->rx_opt.mss_clamp = tp->advmss; /* If MSS is not cached */
> - tcp_fastopen_cache_get(sk, &tp->rx_opt.mss_clamp, &fo->cookie,
> - &syn_loss, &last_syn_loss);
> - /* Recurring FO SYN losses: revert to regular handshake temporarily */
> - if (syn_loss > 1 &&
> - time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {
> - fo->cookie.len = -1;
> - goto fallback;
> - }
> -
> - if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE)
> - fo->cookie.len = -1;
> - else if (fo->cookie.len <= 0)
> + if (!tcp_fastopen_cookie_check(sk, &tp->rx_opt.mss_clamp,
> &fo->cookie))
> goto fallback;
>
> /* MSS for SYN-data is based on cached MSS and bounded by PMTU and
> --
> 2.11.0.483.g087da7b7c-goog
>
