linux/net/mptcp/bpf.c
Geliang Tang 0dd061a6a1 bpf: Add update_socket_protocol hook
Add a hook named update_socket_protocol in __sys_socket(), for bpf
progs to attach to and update socket protocol. One user case is to
force legacy TCP apps to create and use MPTCP sockets instead of
TCP ones.

Define a fmod_ret set named bpf_mptcp_fmodret_ids, add the hook
update_socket_protocol into this set, and register it in
bpf_mptcp_kfunc_init().

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/79
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Link: https://lore.kernel.org/r/ac84be00f97072a46f8a72b4e2be46cbb7fa5053.1692147782.git.geliang.tang@suse.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-16 10:22:16 -07:00

37 lines
872 B
C

// SPDX-License-Identifier: GPL-2.0
/* Multipath TCP
*
* Copyright (c) 2020, Tessares SA.
* Copyright (c) 2022, SUSE.
*
* Author: Nicolas Rybowski <nicolas.rybowski@tessares.net>
*/
#define pr_fmt(fmt) "MPTCP: " fmt
#include <linux/bpf.h>
#include "protocol.h"
struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk)
{
if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))
return mptcp_sk(mptcp_subflow_ctx(sk)->conn);
return NULL;
}
BTF_SET8_START(bpf_mptcp_fmodret_ids)
BTF_ID_FLAGS(func, update_socket_protocol)
BTF_SET8_END(bpf_mptcp_fmodret_ids)
static const struct btf_kfunc_id_set bpf_mptcp_fmodret_set = {
.owner = THIS_MODULE,
.set = &bpf_mptcp_fmodret_ids,
};
static int __init bpf_mptcp_kfunc_init(void)
{
return register_btf_fmodret_id_set(&bpf_mptcp_fmodret_set);
}
late_initcall(bpf_mptcp_kfunc_init);