diff mbox series

[bpf-next,1/2] bpf: Adds support for setting window clamp

Message ID 20201201164357.2623610-2-prankgup@fb.com
State Not Applicable
Headers show
Series Add support to set window_clamp from bpf setsockops | expand

Commit Message

Prankur gupta Dec. 1, 2020, 4:43 p.m. UTC 
Adds a new bpf_setsockopt for TCP sockets, TCP_BPF_WINDOW_CLAMP,
which sets the maximum receiver window size. It will be useful for
limiting receiver window based on RTT.

Signed-off-by: Prankur gupta <prankgup@fb.com>
---
 net/core/filter.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Alexei Starovoitov Dec. 2, 2020, 2:14 a.m. UTC | #1 
On Tue, Dec 01, 2020 at 08:43:56AM -0800, Prankur gupta wrote:
> Adds a new bpf_setsockopt for TCP sockets, TCP_BPF_WINDOW_CLAMP,
> which sets the maximum receiver window size. It will be useful for
> limiting receiver window based on RTT.
> 
> Signed-off-by: Prankur gupta <prankgup@fb.com>
> ---
>  net/core/filter.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 2ca5eecebacf..8c52ffae7b0c 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4910,6 +4910,19 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
>  				tp->notsent_lowat = val;
>  				sk->sk_write_space(sk);
>  				break;
> +			case TCP_WINDOW_CLAMP:
> +				if (!val) {
> +					if (sk->sk_state != TCP_CLOSE) {
> +						ret = -EINVAL;
> +						break;
> +					}
> +					tp->window_clamp = 0;
> +				} else {
> +					tp->window_clamp =
> +						val < SOCK_MIN_RCVBUF / 2 ?
> +						SOCK_MIN_RCVBUF / 2 : val;
> +				}

May be extract this logic into a helper instead of copy-paste?
diff mbox series

Patch

diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacf..8c52ffae7b0c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4910,6 +4910,19 @@  static int _bpf_setsockopt(struct sock *sk, int level, int optname,
 				tp->notsent_lowat = val;
 				sk->sk_write_space(sk);
 				break;
+			case TCP_WINDOW_CLAMP:
+				if (!val) {
+					if (sk->sk_state != TCP_CLOSE) {
+						ret = -EINVAL;
+						break;
+					}
+					tp->window_clamp = 0;
+				} else {
+					tp->window_clamp =
+						val < SOCK_MIN_RCVBUF / 2 ?
+						SOCK_MIN_RCVBUF / 2 : val;
+				}
+				break;
 			default:
 				ret = -EINVAL;
 			}