Re: [PATCH net,v2] tcp: Fix broken repair socket window probe patch
From: Andrey Vagin
Date: Mon Jul 16 2018 - 13:52:11 EST
On Sun, Jul 15, 2018 at 11:36:37AM -0400, Stefan Baranoff wrote:
> Correct previous bad attempt at allowing sockets to come out of TCP
> repair without sending window probes. To avoid changing size of
> the repair variable in struct tcp_sock, this lets the decision for
> sending probes or not to be made when coming out of repair by
> introducing two ways to turn it off.
>
> v2:
> * Remove erroneous comment; defines now make behavior clear
>
> Fixes: 70b7ff130224 ("tcp: allow user to create repair socket without window probes")
> Signed-off-by: Stefan Baranoff <sbaranoff@xxxxxxxxx>
Acked-by: Andrei Vagin <avagin@xxxxxxxxxxxxx>
> ---
> include/uapi/linux/tcp.h | 4 ++++
> net/ipv4/tcp.c | 13 +++++++------
> 2 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
> index 29eb659..e3f6ed8 100644
> --- a/include/uapi/linux/tcp.h
> +++ b/include/uapi/linux/tcp.h
> @@ -127,6 +127,10 @@ enum {
>
> #define TCP_CM_INQ TCP_INQ
>
> +#define TCP_REPAIR_ON 1
> +#define TCP_REPAIR_OFF 0
> +#define TCP_REPAIR_OFF_NO_WP -1 /* Turn off without window probes */
> +
> struct tcp_repair_opt {
> __u32 opt_code;
> __u32 opt_val;
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 8e5e2ca..ec2186e 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -2823,16 +2823,17 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
> case TCP_REPAIR:
> if (!tcp_can_repair_sock(sk))
> err = -EPERM;
> - /* 1 for normal repair, 2 for no window probes */
> - else if (val == 1 || val == 2) {
> - tp->repair = val;
> + else if (val == TCP_REPAIR_ON) {
> + tp->repair = 1;
> sk->sk_reuse = SK_FORCE_REUSE;
> tp->repair_queue = TCP_NO_QUEUE;
> - } else if (val == 0) {
> + } else if (val == TCP_REPAIR_OFF) {
> + tp->repair = 0;
> + sk->sk_reuse = SK_NO_REUSE;
> + tcp_send_window_probe(sk);
> + } else if (val == TCP_REPAIR_OFF_NO_WP) {
> tp->repair = 0;
> sk->sk_reuse = SK_NO_REUSE;
> - if (tp->repair == 1)
> - tcp_send_window_probe(sk);
> } else
> err = -EINVAL;
>
> --
> 1.8.3.1
>