[PATCH bpf-next 7/7] selftests/bpf: Avoid pinning prog when attaching to tc ingress in btf_skc_cls_ingress

[Martin KaFai Lau <martin.lau@xxxxxxxxx>]

From: Martin KaFai Lau <martin.lau@xxxxxxxxxx>

This patch removes the need to pin prog when attaching to tc ingress
in the btf_skc_cls_ingress test.  Instead, directly use the
bpf_tc_hook_create() and bpf_tc_attach().  The qdisc clsact
will go away together with the netns, so no need to
bpf_tc_hook_destroy().

Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
---
 .../bpf/prog_tests/btf_skc_cls_ingress.c      | 25 ++++++++-----------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c
index 7a277035c275..ef4d6a3ae423 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c
@@ -9,6 +9,7 @@
 #include <string.h>
 #include <errno.h>
 #include <sched.h>
+#include <net/if.h>
 #include <linux/compiler.h>
 #include <bpf/libbpf.h>
 
@@ -20,10 +21,12 @@ static struct test_btf_skc_cls_ingress *skel;
 static struct sockaddr_in6 srv_sa6;
 static __u32 duration;
 
-#define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress"
-
 static int prepare_netns(void)
 {
+	LIBBPF_OPTS(bpf_tc_hook, qdisc_lo, .attach_point = BPF_TC_INGRESS);
+	LIBBPF_OPTS(bpf_tc_opts, tc_attach,
+		    .prog_fd = bpf_program__fd(skel->progs.cls_ingress));
+
 	if (CHECK(unshare(CLONE_NEWNET), "create netns",
 		  "unshare(CLONE_NEWNET): %s (%d)",
 		  strerror(errno), errno))
@@ -33,12 +36,12 @@ static int prepare_netns(void)
 		  "ip link set dev lo up", "failed\n"))
 		return -1;
 
-	if (CHECK(system("tc qdisc add dev lo clsact"),
-		  "tc qdisc add dev lo clsact", "failed\n"))
+	qdisc_lo.ifindex = if_nametoindex("lo");
+	if (!ASSERT_OK(bpf_tc_hook_create(&qdisc_lo), "qdisc add dev lo clsact"))
 		return -1;
 
-	if (CHECK(system("tc filter add dev lo ingress bpf direct-action object-pinned " PROG_PIN_FILE),
-		  "install tc cls-prog at ingress", "failed\n"))
+	if (!ASSERT_OK(bpf_tc_attach(&qdisc_lo, &tc_attach),
+		       "filter add dev lo ingress"))
 		return -1;
 
 	/* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the
@@ -195,19 +198,12 @@ static struct test tests[] = {
 
 void test_btf_skc_cls_ingress(void)
 {
-	int i, err;
+	int i;
 
 	skel = test_btf_skc_cls_ingress__open_and_load();
 	if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n"))
 		return;
 
-	err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE);
-	if (CHECK(err, "bpf_program__pin",
-		  "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) {
-		test_btf_skc_cls_ingress__destroy(skel);
-		return;
-	}
-
 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		if (!test__start_subtest(tests[i].desc))
 			continue;
@@ -221,6 +217,5 @@ void test_btf_skc_cls_ingress(void)
 		reset_test();
 	}
 
-	bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE);
 	test_btf_skc_cls_ingress__destroy(skel);
 }
-- 
2.30.2