bpf: Add bpf_skc_to_mptcp_sock_proto

This patch implements a new struct bpf_func_proto, named
bpf_skc_to_mptcp_sock_proto. Define a new bpf_id BTF_SOCK_TYPE_MPTCP,
and a new helper bpf_skc_to_mptcp_sock(), which invokes another new
helper bpf_mptcp_sock_from_subflow() in net/mptcp/bpf.c to get struct
mptcp_sock from a given subflow socket.

v2: Emit BTF type, add func_id checks in verifier.c and bpf_trace.c,
remove build check for CONFIG_BPF_JIT
v5: Drop EXPORT_SYMBOL (Martin)

Co-developed-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220519233016.105670-2-mathew.j.martineau@linux.intel.com
This commit is contained in:
Geliang Tang
2022-05-19 16:30:10 -07:00
committed by Andrii Nakryiko
parent 7aa424e02a
commit 3bc253c2e6
11 changed files with 69 additions and 1 deletions

View File

@@ -10,3 +10,5 @@ obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o
mptcp_crypto_test-objs := crypto_test.o
mptcp_token_test-objs := token_test.o
obj-$(CONFIG_MPTCP_KUNIT_TEST) += mptcp_crypto_test.o mptcp_token_test.o
obj-$(CONFIG_BPF_SYSCALL) += bpf.o

21
net/mptcp/bpf.c Normal file
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@@ -0,0 +1,21 @@
// 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;
}