From: Prankur gupta <prankgup@fb.com>
To: <bpf@vger.kernel.org>
Cc: <kernel-team@fb.com>, <netdev@vger.kernel.org>
Subject: [PATCH v4 bpf-next 1/2] bpf: Adds support for setting window clamp
Date: Wed, 2 Dec 2020 13:31:51 -0800 [thread overview]
Message-ID: <20201202213152.435886-2-prankgup@fb.com> (raw)
In-Reply-To: <20201202213152.435886-1-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>
---
include/net/tcp.h | 1 +
net/core/filter.c | 3 +++
net/ipv4/tcp.c | 25 ++++++++++++++++---------
3 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 4aba0f069b05..347a76f176b4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -406,6 +406,7 @@ void tcp_syn_ack_timeout(const struct request_sock *req);
int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
int flags, int *addr_len);
int tcp_set_rcvlowat(struct sock *sk, int val);
+int tcp_set_window_clamp(struct sock *sk, int val);
void tcp_data_ready(struct sock *sk);
#ifdef CONFIG_MMU
int tcp_mmap(struct file *file, struct socket *sock,
diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacf..6273883dfeb2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4910,6 +4910,9 @@ 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:
+ ret = tcp_set_window_clamp(sk, val);
+ break;
default:
ret = -EINVAL;
}
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b2bc3d7fe9e8..17379f6dd955 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3022,6 +3022,21 @@ int tcp_sock_set_keepcnt(struct sock *sk, int val)
}
EXPORT_SYMBOL(tcp_sock_set_keepcnt);
+int tcp_set_window_clamp(struct sock *sk, int val)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (!val) {
+ if (sk->sk_state != TCP_CLOSE)
+ return -EINVAL;
+ tp->window_clamp = 0;
+ } else {
+ tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
+ SOCK_MIN_RCVBUF / 2 : val;
+ }
+ return 0;
+}
+
/*
* Socket option code for TCP.
*/
@@ -3235,15 +3250,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname,
break;
case TCP_WINDOW_CLAMP:
- if (!val) {
- if (sk->sk_state != TCP_CLOSE) {
- err = -EINVAL;
- break;
- }
- tp->window_clamp = 0;
- } else
- tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
- SOCK_MIN_RCVBUF / 2 : val;
+ err = tcp_set_window_clamp(sk, val);
break;
case TCP_QUICKACK:
--
2.24.1
next prev parent reply other threads:[~2020-12-02 21:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 21:31 [PATCH v4 bpf-next 0/2] Add support to set window_clamp from bpf setsockops Prankur gupta
2020-12-02 21:31 ` Prankur gupta [this message]
2020-12-02 21:31 ` [PATCH v4 bpf-next 2/2] selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP Prankur gupta
2020-12-03 20:51 ` [PATCH v4 bpf-next 0/2] Add support to set window_clamp from bpf setsockops Martin KaFai Lau
2020-12-04 1:44 ` Alexei Starovoitov
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