Merge branch 'selftests-bpf-convert-test_tc_edt-sh-into-test_progs'

Alexis Lothoré says:

====================
selftests/bpf: convert test_tc_edt.sh into test_progs

Hello,
this is a (late) v2 to my first attempt to convert the test_tc_edt
script to test_progs. This new version is way simpler, thanks to
Martin's suggestion about properly using the existing network_helpers
rather than reinventing the wheel. It also fixes a small bug in the
measured effective rate.

The converted test roughly follows the original script logic, with two
veths in two namespaces, a TCP connection between a client and a server,
and the client pushing a specific amount of data. Time is recorded
before and after the transmission to compute the effective rate.

There are two knobs driving the robustness of the test in CI:
- the amount of pushed data (the higher, the more precise is the
  effective rate)
- the tolerated error margin

The original test was configured with a 20s duration and a 1% error
margin. The new test is configured with 1MB of data being pushed and a
2% error margin, to:
- make the duration tolerable in CI
- while keeping enough margin for rate measure fluctuations depending on
  the CI machines load

This has been run multiple times locally to ensure that those values are
sane, and once in CI before sending the series, but I suggest to let it
live a few days in CI to see how it really behaves.

Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]>

Changes in v2:
- drop custom client/server management
- update bpf program now that server pushes data
- fix effective rate computation
- Link to v1: https://lore.kernel.org/r/[email protected]

---
Alexis Lothoré (eBPF Foundation) (4):
      selftests/bpf: rename test_tc_edt.bpf.c section to expose program type
      selftests/bpf: integrate test_tc_edt into test_progs
      selftests/bpf: remove test_tc_edt.sh
      selftests/bpf: do not hardcode target rate in test_tc_edt BPF program

 tools/testing/selftests/bpf/Makefile               |   2 -
 .../testing/selftests/bpf/prog_tests/test_tc_edt.c | 145 +++++++++++++++++++++
 tools/testing/selftests/bpf/progs/test_tc_edt.c    |  11 +-
 tools/testing/selftests/bpf/test_tc_edt.sh         | 100 --------------
 4 files changed, 151 insertions(+), 107 deletions(-)
---
base-commit: 233a075a1b27070af76d64541cf001340ecff917
change-id: 20251030-tc_edt-3ea8e8d3d14e

Best regards,
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

Author: Alexei Starovoitov

tools/testing/selftests/bpf/Makefile

@@ -99,13 +99,11 @@ TEST_GEN_PROGS += test_progs-cpuv4
 TEST_INST_SUBDIRS += cpuv4
 endif
 
-TEST_GEN_FILES = test_tc_edt.bpf.o
 TEST_FILES = xsk_prereqs.sh $(wildcard progs/btf_dump_test_case_*.c)
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
 	test_lirc_mode2.sh \
-	test_tc_edt.sh \
 	test_xdping.sh \
 	test_bpftool_build.sh \
 	test_bpftool.sh \

tools/testing/selftests/bpf/prog_tests/test_tc_edt.c

@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+/*
+ * BPF-based flow shaping
+ *
+ * The test brings up two veth in two isolated namespaces, attach some flow
+ * shaping program onto it, and ensures that a manual speedtest maximum
+ * value matches the rate set in the BPF shapers.
+ */
+
+#include <asm-generic/socket.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <math.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <bpf/libbpf.h>
+#include <pthread.h>
+#include "test_progs.h"
+#include "network_helpers.h"
+#include "test_tc_edt.skel.h"
+
+#define SERVER_NS "tc-edt-server-ns"
+#define CLIENT_NS "tc-edt-client-ns"
+#define IP4_ADDR_VETH1 "192.168.1.1"
+#define IP4_ADDR_VETH2 "192.168.1.2"
+#define IP4_ADDR_VETH2_HEX 0xC0A80102
+
+#define TIMEOUT_MS		2000
+#define TEST_PORT		9000
+#define TARGET_RATE_MBPS	5.0
+#define TX_BYTES_COUNT		(1 * 1000 * 1000)
+#define RATE_ERROR_PERCENT	2.0
+
+struct connection {
+	int server_listen_fd;
+	int server_conn_fd;
+	int client_conn_fd;
+};
+
+static int setup(struct test_tc_edt *skel)
+{
+	struct nstoken *nstoken_client, *nstoken_server;
+	int ret;
+
+	if (!ASSERT_OK(make_netns(CLIENT_NS), "create client ns"))
+		goto fail;
+	if (!ASSERT_OK(make_netns(SERVER_NS), "create server ns"))
+		goto fail_delete_client_ns;
+
+	nstoken_client = open_netns(CLIENT_NS);
+	if (!ASSERT_OK_PTR(nstoken_client, "open client ns"))
+		goto fail_delete_server_ns;
+	SYS(fail_close_client_ns, "ip link add veth1 type veth peer name %s",
+	    "veth2 netns " SERVER_NS);
+	SYS(fail_close_client_ns, "ip -4 addr add " IP4_ADDR_VETH1 "/24 dev veth1");
+	SYS(fail_close_client_ns, "ip link set veth1 up");
+
+	nstoken_server = open_netns(SERVER_NS);
+	if (!ASSERT_OK_PTR(nstoken_server, "enter server ns"))
+		goto fail_close_client_ns;
+	SYS(fail_close_server_ns, "ip -4 addr add " IP4_ADDR_VETH2 "/24 dev veth2");
+	SYS(fail_close_server_ns, "ip link set veth2 up");
+	SYS(fail_close_server_ns, "tc qdisc add dev veth2 root fq");
+	ret = tc_prog_attach("veth2", -1, bpf_program__fd(skel->progs.tc_prog));
+	if (!ASSERT_OK(ret, "attach bpf prog"))
+		goto fail_close_server_ns;
+	skel->bss->target_rate = TARGET_RATE_MBPS * 1000 * 1000;
+	close_netns(nstoken_server);
+	close_netns(nstoken_client);
+
+	return 0;
+
+fail_close_server_ns:
+	close_netns(nstoken_server);
+fail_close_client_ns:
+	close_netns(nstoken_client);
+fail_delete_server_ns:
+	remove_netns(SERVER_NS);
+fail_delete_client_ns:
+	remove_netns(CLIENT_NS);
+fail:
+	return -1;
+}
+
+static void cleanup(void)
+{
+	remove_netns(CLIENT_NS);
+	remove_netns(SERVER_NS);
+}
+
+static void run_test(void)
+{
+	int server_fd, client_fd, err;
+	double rate_mbps, rate_error;
+	struct nstoken *nstoken;
+	__u64 ts_start, ts_end;
+
+	nstoken = open_netns(SERVER_NS);
+	if (!ASSERT_OK_PTR(nstoken, "open server ns"))
+		return;
+	server_fd = start_server(AF_INET, SOCK_STREAM, IP4_ADDR_VETH2,
+			TEST_PORT, TIMEOUT_MS);
+	if (!ASSERT_OK_FD(server_fd, "start server"))
+		return;
+
+	close_netns(nstoken);
+	nstoken = open_netns(CLIENT_NS);
+	if (!ASSERT_OK_PTR(nstoken, "open client ns"))
+		return;
+	client_fd = connect_to_fd(server_fd, 0);
+	if (!ASSERT_OK_FD(client_fd, "connect client"))
+		return;
+
+	ts_start = get_time_ns();
+	err = send_recv_data(server_fd, client_fd, TX_BYTES_COUNT);
+	ts_end = get_time_ns();
+	close_netns(nstoken);
+	ASSERT_OK(err, "send_recv_data");
+
+	rate_mbps = TX_BYTES_COUNT / ((ts_end - ts_start) / 1000.0);
+	rate_error =
+		fabs((rate_mbps - TARGET_RATE_MBPS) * 100.0 / TARGET_RATE_MBPS);
+
+	ASSERT_LE(rate_error, RATE_ERROR_PERCENT,
+		  "rate error is lower than threshold");
+}
+
+void test_tc_edt(void)
+{
+	struct test_tc_edt *skel;
+
+	skel = test_tc_edt__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel open and load"))
+		return;
+
+	if (!ASSERT_OK(setup(skel), "global setup"))
+		return;
+
+	run_test();
+
+	cleanup();
+	test_tc_edt__destroy(skel);
+}

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

@@ -14,7 +14,6 @@
 #define TIME_HORIZON_NS (2000 * 1000 * 1000)
 #define NS_PER_SEC 1000000000
 #define ECN_HORIZON_NS 5000000
-#define THROTTLE_RATE_BPS (5 * 1000 * 1000)
 
 /* flow_key => last_tstamp timestamp used */
 struct {
@@ -24,12 +23,13 @@ struct {
 	__uint(max_entries, 1);
 } flow_map SEC(".maps");
 
+__uint64_t target_rate;
+
 static inline int throttle_flow(struct __sk_buff *skb)
 {
 	int key = 0;
 	uint64_t *last_tstamp = bpf_map_lookup_elem(&flow_map, &key);
-	uint64_t delay_ns = ((uint64_t)skb->len) * NS_PER_SEC /
-			THROTTLE_RATE_BPS;
+	uint64_t delay_ns = ((uint64_t)skb->len) * NS_PER_SEC / target_rate;
 	uint64_t now = bpf_ktime_get_ns();
 	uint64_t tstamp, next_tstamp = 0;
 
@@ -70,7 +70,7 @@ static inline int handle_tcp(struct __sk_buff *skb, struct tcphdr *tcp)
 	if ((void *)(tcp + 1) > data_end)
 		return TC_ACT_SHOT;
 
-	if (tcp->dest == bpf_htons(9000))
+	if (tcp->source == bpf_htons(9000))
 		return throttle_flow(skb);
 
 	return TC_ACT_OK;
@@ -99,7 +99,8 @@ static inline int handle_ipv4(struct __sk_buff *skb)
 	return TC_ACT_OK;
 }
 
-SEC("cls_test") int tc_prog(struct __sk_buff *skb)
+SEC("tc")
+int tc_prog(struct __sk_buff *skb)
 {
 	if (skb->protocol == bpf_htons(ETH_P_IP))
 		return handle_ipv4(skb);