selftests/bpf: mptcp tracepoint tests

Signed-off-by: Geliang Tang <[email protected]>

include/trace/events/mptcp.h

@@ -22,6 +22,7 @@ TRACE_EVENT(mptcp_subflow_get_send,
 	TP_ARGS(subflow),
 
 	TP_STRUCT__entry(
+		__field(struct mptcp_sock *, msk)
 		__field(bool, active)
 		__field(bool, free)
 		__field(u32, snd_wnd)
@@ -42,6 +43,7 @@ TRACE_EVENT(mptcp_subflow_get_send,
 			__entry->free = 0;
 
 		ssk = mptcp_subflow_tcp_sock(subflow);
+		__entry->msk = mptcp_sk(mptcp_subflow_ctx(ssk)->conn);
 		if (ssk && sk_fullsock(ssk)) {
 			__entry->snd_wnd = tcp_sk(ssk)->snd_wnd;
 			__entry->pace = READ_ONCE(ssk->sk_pacing_rate);

tools/testing/selftests/bpf/progs/mptcp_bpf_iters_subflow.c

@@ -42,3 +42,19 @@ int BPF_PROG(trace_mptcp_sched_get_send, struct mptcp_sock *msk)
 
 	return 0;
 }
+
+/* tools/testing/selftests/bpf/tools/include/vmlinux.h */
+SEC("tracepoint/mptcp/mptcp_subflow_get_send")
+int trace_get_send(struct trace_event_raw_mptcp_subflow_get_send *ctx)
+{
+	struct mptcp_sock *msk = bpf_core_cast(ctx->msk, struct mptcp_sock);
+	struct mptcp_subflow_context *subflow;
+	int i = 0;
+
+	mptcp_for_each_subflow(msk, subflow) {
+		bpf_printk("bpf_iter tracepoint i=%d subflows=%u", i++, msk->pm.subflows);
+	}
+
+	bpf_printk("trace_get_send snd_wnd=%u token=%u", ctx->snd_wnd, msk->token);
+	return 0;
+}