1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Facebook */
3
4#include <test_progs.h>
5#include <sys/stat.h>
6
7#include "test_link_pinning.skel.h"
8
9static int duration = 0;
10
11void test_link_pinning_subtest(struct bpf_program *prog,
12			       struct test_link_pinning__bss *bss)
13{
14	const char *link_pin_path = "/sys/fs/bpf/pinned_link_test";
15	struct stat statbuf = {};
16	struct bpf_link *link;
17	int err, i;
18
19	link = bpf_program__attach(prog);
20	if (!ASSERT_OK_PTR(link, "link_attach"))
21		goto cleanup;
22
23	bss->in = 1;
24	usleep(1);
25	CHECK(bss->out != 1, "res_check1", "exp %d, got %d\n", 1, bss->out);
26
27	/* pin link */
28	err = bpf_link__pin(link, link_pin_path);
29	if (CHECK(err, "link_pin", "err: %d\n", err))
30		goto cleanup;
31
32	CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path1",
33	      "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link));
34
35	/* check that link was pinned */
36	err = stat(link_pin_path, &statbuf);
37	if (CHECK(err, "stat_link", "err %d errno %d\n", err, errno))
38		goto cleanup;
39
40	bss->in = 2;
41	usleep(1);
42	CHECK(bss->out != 2, "res_check2", "exp %d, got %d\n", 2, bss->out);
43
44	/* destroy link, pinned link should keep program attached */
45	bpf_link__destroy(link);
46	link = NULL;
47
48	bss->in = 3;
49	usleep(1);
50	CHECK(bss->out != 3, "res_check3", "exp %d, got %d\n", 3, bss->out);
51
52	/* re-open link from BPFFS */
53	link = bpf_link__open(link_pin_path);
54	if (!ASSERT_OK_PTR(link, "link_open"))
55		goto cleanup;
56
57	CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path2",
58	      "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link));
59
60	/* unpin link from BPFFS, program still attached */
61	err = bpf_link__unpin(link);
62	if (CHECK(err, "link_unpin", "err: %d\n", err))
63		goto cleanup;
64
65	/* still active, as we have FD open now */
66	bss->in = 4;
67	usleep(1);
68	CHECK(bss->out != 4, "res_check4", "exp %d, got %d\n", 4, bss->out);
69
70	bpf_link__destroy(link);
71	link = NULL;
72
73	/* Validate it's finally detached.
74	 * Actual detachment might get delayed a bit, so there is no reliable
75	 * way to validate it immediately here, let's count up for long enough
76	 * and see if eventually output stops being updated
77	 */
78	for (i = 5; i < 10000; i++) {
79		bss->in = i;
80		usleep(1);
81		if (bss->out == i - 1)
82			break;
83	}
84	CHECK(i == 10000, "link_attached", "got to iteration #%d\n", i);
85
86cleanup:
87	bpf_link__destroy(link);
88}
89
90void test_link_pinning(void)
91{
92	struct test_link_pinning* skel;
93
94	skel = test_link_pinning__open_and_load();
95	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
96		return;
97
98	if (test__start_subtest("pin_raw_tp"))
99		test_link_pinning_subtest(skel->progs.raw_tp_prog, skel->bss);
100	if (test__start_subtest("pin_tp_btf"))
101		test_link_pinning_subtest(skel->progs.tp_btf_prog, skel->bss);
102
103	test_link_pinning__destroy(skel);
104}
105