Re: [PATCH net] tcp: Fix broken repair socket window probe patch

From: Neal Cardwell
Date: Sun Jul 15 2018 - 10:57:59 EST


On Sat, Jul 14, 2018 at 9:54 PM Stefan Baranoff <sbaranoff@xxxxxxxxx> 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.
>
> Fixes: 70b7ff130224 ("tcp: allow user to create repair socket without window probes")
> Signed-off-by: Stefan Baranoff <sbaranoff@xxxxxxxxx>
> ---
> include/uapi/linux/tcp.h | 4 ++++
> net/ipv4/tcp.c | 12 +++++++-----
> 2 files changed, 11 insertions(+), 5 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..9163fb1 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -2824,15 +2824,17 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
> if (!tcp_can_repair_sock(sk))
> err = -EPERM;
> /* 1 for normal repair, 2 for no window probes */

Looks like this comment is now inconsistent with the code.

cheers,
neal