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From: Prankur gupta <prankgup@fb.com>
To: <bpf@vger.kernel.org>
Cc: <kernel-team@fb.com>, <netdev@vger.kernel.org>
Subject: [PATCH bpf-next 1/2] bpf: Adds support for setting window clamp
Date: Tue, 1 Dec 2020 08:43:56 -0800	[thread overview]
Message-ID: <20201201164357.2623610-2-prankgup@fb.com> (raw)
In-Reply-To: <20201201164357.2623610-1-prankgup@fb.com>

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;
+				}
+				break;
 			default:
 				ret = -EINVAL;
 			}
-- 
2.24.1


  reply	other threads:[~2020-12-01 16:44 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-01 16:43 [PATCH v2 bpf-next 0/2] Add support to set window_clamp from bpf setsockops Prankur gupta
2020-12-01 16:43 ` Prankur gupta [this message]
2020-12-02  2:14   ` [PATCH bpf-next 1/2] bpf: Adds support for setting window clamp Alexei Starovoitov
2020-12-01 16:43 ` [PATCH bpf-next 2/2] selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP Prankur gupta
  -- strict thread matches above, loose matches on Subject: below --
2020-12-01  0:03 [PATCH bpf-next 0/2] Add support to set window_clamp from bpf setsockops Prankur gupta
2020-12-01  0:03 ` [PATCH bpf-next 1/2] bpf: Adds support for setting window clamp Prankur gupta
2020-12-01  1:34   ` Alexei Starovoitov

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