On 12/19/24 7:46 AM, Matthieu Baerts (NGI0) wrote:
+SEC("cgroup/getsockopt")
+int iters_subflow(struct bpf_sockopt *ctx)
+{
+ struct mptcp_subflow_context *subflow;
+ struct bpf_sock *sk = ctx->sk;
+ struct sock *ssk = NULL;
+ struct mptcp_sock *msk;
+ int local_ids = 0;
+
+ if (ctx->level != SOL_TCP || ctx->optname != TCP_IS_MPTCP)
+ return 1;
+
+ msk = bpf_skc_to_mptcp_sock(sk);
+ if (!msk || msk->pm.server_side || !msk->pm.subflows)
+ return 1;
+
+ msk = bpf_mptcp_sock_acquire(msk);
+ if (!msk)
+ return 1;
+ bpf_for_each(mptcp_subflow, subflow, msk) {
+ /* Here MPTCP-specific packet scheduler kfunc can be called:
+ * this test is not doing anything really useful, only to
+ * verify the iteration works.
+ */
+
+ local_ids += subflow->subflow_id;
+
+ /* only to check the following kfunc works */
+ ssk = mptcp_subflow_tcp_sock(subflow);
It is good to have test cases to exercise the new iter and kfunc. Thanks.
However, it seems not useful to show how it will be used in the future
packet/subflow scheduler. iiuc, the core piece is in bpf_struct_ops. Without it,
it is hard to comment. Any RFC patches ready to be posted?
+ }
+
+ if (!ssk)
+ goto out;
+
+ /* assert: if not OK, something wrong on the kernel side */
+ if (ssk->sk_dport != ((struct sock *)msk)->sk_dport)
+ goto out;
+
+ /* only to check the following kfunc works */
+ subflow = bpf_mptcp_subflow_ctx(ssk);
+ if (!subflow || subflow->token != msk->token)
+ goto out;
+
+ ids = local_ids;
+
+out:
+ bpf_mptcp_sock_release(msk);
+ return 1;
+}
