diff mbox series

[mptcp-next,v10,3/9] bpf: Acquire and release mptcp socket

Message ID 7442bbc9df71fb9b333e674b0421f2a7b8f6b74f.1729063444.git.tanggeliang@kylinos.cn (mailing list archive)
State Superseded, archived
Headers show
Series add mptcp_subflow bpf_iter | expand

Checks

Context Check Description
matttbe/checkpatch success total: 0 errors, 0 warnings, 0 checks, 30 lines checked
matttbe/shellcheck success MPTCP selftests files have not been modified
matttbe/build success Build and static analysis OK

Commit Message

Geliang Tang Oct. 16, 2024, 7:33 a.m. UTC 
From: Geliang Tang <tanggeliang@kylinos.cn>

The KF_TRUSTED_ARGS flag is used for bpf_iter_mptcp_subflow_new, it
indicates that the all pointer arguments are valid. It's necessary to
add a KF_ACQUIRE helper to get valid "msk".

This patch adds bpf_mptcp_sock_acquire() and bpf_mptcp_sock_release()
helpers for this. Increase sk->sk_refcnt in _acquire() and decrease it
in _release(). Register them with KF_ACQUIRE flag and KF_RELEASE flag.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
diff mbox series

Patch

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index 405907b79d4d..19dbf28018f5 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -255,6 +255,22 @@  __bpf_kfunc static void bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_sub
 {
 }
 
+__bpf_kfunc static struct mptcp_sock *bpf_mptcp_sock_acquire(struct mptcp_sock *msk)
+{
+	struct sock *sk = (struct sock *)msk;
+
+	if (sk && refcount_inc_not_zero(&sk->sk_refcnt))
+		return msk;
+	return NULL;
+}
+
+__bpf_kfunc static void bpf_mptcp_sock_release(struct mptcp_sock *msk)
+{
+	struct sock *sk = (struct sock *)msk;
+
+	WARN_ON_ONCE(!sk || !refcount_dec_not_one(&sk->sk_refcnt));
+}
+
 __bpf_kfunc struct mptcp_subflow_context *
 bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos)
 {
@@ -276,6 +292,8 @@  BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock)
 BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_ARGS)
 BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy, KF_ITER_DESTROY)
+BTF_ID_FLAGS(func, bpf_mptcp_sock_acquire, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_mptcp_sock_release, KF_RELEASE)
 BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
 
 static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {