[PATCH mptcp-next v3 09/15] mptcp: add three helpers for bpf_burst

[Geliang Tang <geliang.tang@suse.com>]

This patch adds three helpers needed to export into the BPF context for
bpf_burst scheduler: mptcp_get_linger_time(), mptcp_get_burst() and
mptcp_get_pacing_rate().

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/protocol.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c8fd0915fa0b..8dbc9b9c3eb3 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1415,6 +1415,26 @@ bool mptcp_stream_memory_free(struct mptcp_subflow_context *subflow)
 	return sk_stream_memory_free(ssk);
 }
 
+u64 mptcp_get_linger_time(struct sock *ssk, u32 pace)
+{
+	return div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace);
+}
+
+u32 mptcp_get_burst(const struct mptcp_sock *msk)
+{
+	return min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
+}
+
+unsigned long mptcp_get_pacing_rate(struct mptcp_subflow_context *subflow, u32 burst)
+{
+	struct sock *ssk =  mptcp_subflow_tcp_sock(subflow);
+	u32 wmem = READ_ONCE(ssk->sk_wmem_queued);
+
+	return div_u64((u64)subflow->avg_pacing_rate * wmem +
+		       READ_ONCE(ssk->sk_pacing_rate) * burst,
+		       burst + wmem);
+}
+
 #define SSK_MODE_ACTIVE	0
 #define SSK_MODE_BACKUP	1
 #define SSK_MODE_MAX	2
-- 
2.35.3