From: Geliang Tang <geliang@kernel.org>
To: mptcp@lists.linux.dev
Cc: Nicolas Rybowski <nicolas.rybowski@tessares.net>,
Geliang Tang <tanggeliang@kylinos.cn>
Subject: [PATCH mptcp-next v8 1/4] selftests/bpf: Add mptcp subflow example
Date: Sat, 20 Apr 2024 19:23:26 +0800 [thread overview]
Message-ID: <740fd7f056ea819f92729cf85f0c0dc66399bd7d.1713612119.git.tanggeliang@kylinos.cn> (raw)
In-Reply-To: <cover.1713612119.git.tanggeliang@kylinos.cn>
From: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Move Nicolas's patch into bpf selftests directory. This example added a
test that was adding a different mark (SO_MARK) on each subflow, and
changing the TCP CC only on the first subflow.
This example shows how it is possible to:
Identify the parent msk of an MPTCP subflow.
Put different sockopt for each subflow of a same MPTCP connection.
Here especially, we implemented two different behaviours:
A socket mark (SOL_SOCKET SO_MARK) is put on each subflow of a same
MPTCP connection. The order of creation of the current subflow defines
its mark. The TCP CC algorithm of the very first subflow of an MPTCP
connection is set to "reno".
The code comes from
commit 4d120186e4d6 ("bpf:examples: update mptcp_set_mark_kern.c")
in MPTCP repo https://github.com/multipath-tcp/mptcp_net-next (the
"scripts" branch).
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/76
Co-developed-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
---
.../selftests/bpf/progs/mptcp_subflow.c | 70 +++++++++++++++++++
1 file changed, 70 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/mptcp_subflow.c
diff --git a/tools/testing/selftests/bpf/progs/mptcp_subflow.c b/tools/testing/selftests/bpf/progs/mptcp_subflow.c
new file mode 100644
index 000000000000..de9dbba37133
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/mptcp_subflow.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Tessares SA. */
+/* Copyright (c) 2024, Kylin Software */
+
+#include <sys/socket.h> // SOL_SOCKET, SO_MARK, ...
+#include <linux/tcp.h> // TCP_CONGESTION
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_tcp_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+
+#ifndef SOL_TCP
+#define SOL_TCP 6
+#endif
+
+#ifndef TCP_CA_NAME_MAX
+#define TCP_CA_NAME_MAX 16
+#endif
+
+char cc[TCP_CA_NAME_MAX] = "reno";
+
+/* Associate a subflow counter to each token */
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(__u32));
+ __uint(max_entries, 100);
+} mptcp_sf SEC(".maps");
+
+SEC("sockops")
+int mptcp_subflow(struct bpf_sock_ops *skops)
+{
+ __u32 init = 1, key, mark, *cnt;
+ struct mptcp_sock *msk;
+ struct bpf_sock *sk;
+ int err;
+
+ if (skops->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
+ return 1;
+
+ sk = skops->sk;
+ if (!sk)
+ return 1;
+
+ msk = bpf_skc_to_mptcp_sock(sk);
+ if (!msk)
+ return 1;
+
+ key = msk->token;
+ cnt = bpf_map_lookup_elem(&mptcp_sf, &key);
+ if (cnt) {
+ /* A new subflow is added to an existing MPTCP connection */
+ __sync_fetch_and_add(cnt, 1);
+ mark = *cnt;
+ } else {
+ /* A new MPTCP connection is just initiated and this is its primary subflow */
+ bpf_map_update_elem(&mptcp_sf, &key, &init, BPF_ANY);
+ mark = init;
+ }
+
+ /* Set the mark of the subflow's socket based on appearance order */
+ err = bpf_setsockopt(skops, SOL_SOCKET, SO_MARK, &mark, sizeof(mark));
+ if (err < 0)
+ return 1;
+ if (mark == 1)
+ err = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION, cc, TCP_CA_NAME_MAX);
+
+ return 1;
+}
--
2.40.1
next prev parent reply other threads:[~2024-04-20 11:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-20 11:23 [PATCH mptcp-next v8 0/4] setsockopt per subflow: BPF Geliang Tang
2024-04-20 11:23 ` Geliang Tang [this message]
2024-04-20 11:23 ` [PATCH mptcp-next v8 2/4] selftests/bpf: Add mptcp subflow subtest Geliang Tang
2024-04-23 20:58 ` Mat Martineau
2024-04-20 11:23 ` [PATCH mptcp-next v8 3/4] selftests/bpf: Handle SIGINT when creating netns Geliang Tang
2024-04-20 11:23 ` [PATCH mptcp-next v8 4/4] Squash to "selftests/bpf: Add bpf scheduler test" Geliang Tang
2024-04-20 12:17 ` [PATCH mptcp-next v8 0/4] setsockopt per subflow: BPF MPTCP CI
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=740fd7f056ea819f92729cf85f0c0dc66399bd7d.1713612119.git.tanggeliang@kylinos.cn \
--to=geliang@kernel.org \
--cc=mptcp@lists.linux.dev \
--cc=nicolas.rybowski@tessares.net \
--cc=tanggeliang@kylinos.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.