On 2/16/23 14:50, Andrii Nakryiko wrote:
On Tue, Feb 14, 2023 at 2:17 PM Kui-Feng Lee <kuifeng@xxxxxxxx> wrote:
Create a pair of sockets that utilize the congestion control algorithm
under a particular name. Then switch up this congestion control
algorithm to another implementation and check whether newly created
connections using the same cc name now run the new implementation.
Signed-off-by: Kui-Feng Lee <kuifeng@xxxxxxxx>
---
.../selftests/bpf/prog_tests/bpf_tcp_ca.c | 48 ++++++++++++
.../selftests/bpf/progs/tcp_ca_update.c | 75 +++++++++++++++++++
2 files changed, 123 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/tcp_ca_update.c
[...]
diff --git a/tools/testing/selftests/bpf/progs/tcp_ca_update.c b/tools/testing/selftests/bpf/progs/tcp_ca_update.c
new file mode 100644
index 000000000000..cf51fe54ac01
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tcp_ca_update.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+int ca1_cnt = 0;
+int ca2_cnt = 0;
+
+#define USEC_PER_SEC 1000000UL
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+
+static inline struct tcp_sock *tcp_sk(const struct sock *sk)
+{
+ return (struct tcp_sock *)sk;
+}
+
+SEC("struct_ops/ca_update_init")
+void BPF_PROG(ca_update_init, struct sock *sk)
+{
+#ifdef ENABLE_ATOMICS_TESTS
it's been 2 years since atomics were added to Clang, I think it's fine
to just assume atomic operations are supported and not do the
ENABLE_ATOMICS_TEST (and I'd clean up ENABLE_ATOMICS_TESTS now as
well)
Sure!
+ __sync_bool_compare_and_swap(&sk->sk_pacing_status, SK_PACING_NONE,
+ SK_PACING_NEEDED);
+#else
+ sk->sk_pacing_status = SK_PACING_NEEDED;
+#endif
+}
+
+SEC("struct_ops/ca_update_1_cong_control")
+void BPF_PROG(ca_update_1_cong_control, struct sock *sk,
+ const struct rate_sample *rs)
+{
+ ca1_cnt++;
+}
+
+SEC("struct_ops/ca_update_2_cong_control")
+void BPF_PROG(ca_update_2_cong_control, struct sock *sk,
+ const struct rate_sample *rs)
+{
+ ca2_cnt++;
+}
+
+SEC("struct_ops/ca_update_ssthresh")
+__u32 BPF_PROG(ca_update_ssthresh, struct sock *sk)
+{
+ return tcp_sk(sk)->snd_ssthresh;
+}
+
+SEC("struct_ops/ca_update_undo_cwnd")
+__u32 BPF_PROG(ca_update_undo_cwnd, struct sock *sk)
+{
+ return tcp_sk(sk)->snd_cwnd;
+}
+
+SEC(".struct_ops")
+struct tcp_congestion_ops ca_update_1 = {
+ .init = (void *)ca_update_init,
+ .cong_control = (void *)ca_update_1_cong_control,
+ .ssthresh = (void *)ca_update_ssthresh,
+ .undo_cwnd = (void *)ca_update_undo_cwnd,
+ .name = "tcp_ca_update",
+};
+
+SEC(".struct_ops")
+struct tcp_congestion_ops ca_update_2 = {
+ .init = (void *)ca_update_init,
+ .cong_control = (void *)ca_update_2_cong_control,
+ .ssthresh = (void *)ca_update_ssthresh,
+ .undo_cwnd = (void *)ca_update_undo_cwnd,
+ .name = "tcp_ca_update",
+};
--
2.30.2
