From 4239561b69feb94e52e43d93685cc46fb9dbcae5 Mon Sep 17 00:00:00 2001
From: Yixin Shen <bobankhshen@gmail.com>
Date: Wed, 29 Mar 2023 07:35:58 +0000
Subject: [PATCH] selftests/bpf: test a BPF CC writing app_limited
Test whether a TCP CC implemented in BPF is allowed to write
app_limited in struct tcp_sock. This is already allowed for
the built-in TCP CC.
Signed-off-by: Yixin Shen <bobankhshen@gmail.com>
Link: https://lore.kernel.org/r/20230329073558.8136-3-bobankhshen@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
.../selftests/bpf/progs/tcp_ca_write_sk_pacing.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/progs/tcp_ca_write_sk_pacing.c b/tools/testing/selftests/bpf/progs/tcp_ca_write_sk_pacing.c
index 43447704cf0e6..0724a79cec786 100644
--- a/tools/testing/selftests/bpf/progs/tcp_ca_write_sk_pacing.c
+++ b/tools/testing/selftests/bpf/progs/tcp_ca_write_sk_pacing.c
@@ -16,6 +16,16 @@ static inline struct tcp_sock *tcp_sk(const struct sock *sk)
return (struct tcp_sock *)sk;
}
+static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
+{
+ return tp->sacked_out + tp->lost_out;
+}
+
+static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
+{
+ return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
+}
+
SEC("struct_ops/write_sk_pacing_init")
void BPF_PROG(write_sk_pacing_init, struct sock *sk)
{
@@ -31,11 +41,12 @@ SEC("struct_ops/write_sk_pacing_cong_control")
void BPF_PROG(write_sk_pacing_cong_control, struct sock *sk,
const struct rate_sample *rs)
{
- const struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
unsigned long rate =
((tp->snd_cwnd * tp->mss_cache * USEC_PER_SEC) << 3) /
(tp->srtt_us ?: 1U << 3);
sk->sk_pacing_rate = min(rate, sk->sk_max_pacing_rate);
+ tp->app_limited = (tp->delivered + tcp_packets_in_flight(tp)) ?: 1;
}
SEC("struct_ops/write_sk_pacing_ssthresh")
--
2.30.2