1// SPDX-License-Identifier: GPL-2.0
2
3#include <test_progs.h>
4
5#include "cgroup_helpers.h"
6
7#define PING_CMD "ping -q -c1 -w1 127.0.0.1 > /dev/null"
8
9static char bpf_log_buf[BPF_LOG_BUF_SIZE];
10
11static int prog_load(void)
12{
13 struct bpf_insn prog[] = {
14 BPF_MOV64_IMM(BPF_REG_0, 1), /* r0 = 1 */
15 BPF_EXIT_INSN(),
16 };
17 size_t insns_cnt = ARRAY_SIZE(prog);
18
19 return bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,
20 prog, insns_cnt, "GPL", 0,
21 bpf_log_buf, BPF_LOG_BUF_SIZE);
22}
23
24void serial_test_cgroup_attach_autodetach(void)
25{
26 __u32 duration = 0, prog_cnt = 4, attach_flags;
27 int allow_prog[2] = {-1};
28 __u32 prog_ids[2] = {0};
29 void *ptr = NULL;
30 int cg = 0, i;
31 int attempts;
32
33 for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {
34 allow_prog[i] = prog_load();
35 if (CHECK(allow_prog[i] < 0, "prog_load",
36 "verifier output:\n%s\n-------\n", bpf_log_buf))
37 goto err;
38 }
39
40 if (CHECK_FAIL(setup_cgroup_environment()))
41 goto err;
42
43 /* create a cgroup, attach two programs and remember their ids */
44 cg = create_and_get_cgroup("/cg_autodetach");
45 if (CHECK_FAIL(cg < 0))
46 goto err;
47
48 if (CHECK_FAIL(join_cgroup("/cg_autodetach")))
49 goto err;
50
51 for (i = 0; i < ARRAY_SIZE(allow_prog); i++)
52 if (CHECK(bpf_prog_attach(allow_prog[i], cg,
53 BPF_CGROUP_INET_EGRESS,
54 BPF_F_ALLOW_MULTI),
55 "prog_attach", "prog[%d], errno=%d\n", i, errno))
56 goto err;
57
58 /* make sure that programs are attached and run some traffic */
59 if (CHECK(bpf_prog_query(cg, BPF_CGROUP_INET_EGRESS, 0, &attach_flags,
60 prog_ids, &prog_cnt),
61 "prog_query", "errno=%d\n", errno))
62 goto err;
63 if (CHECK_FAIL(system(PING_CMD)))
64 goto err;
65
66 /* allocate some memory (4Mb) to pin the original cgroup */
67 ptr = malloc(4 * (1 << 20));
68 if (CHECK_FAIL(!ptr))
69 goto err;
70
71 /* close programs and cgroup fd */
72 for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {
73 close(allow_prog[i]);
74 allow_prog[i] = -1;
75 }
76
77 close(cg);
78 cg = 0;
79
80 /* leave the cgroup and remove it. don't detach programs */
81 cleanup_cgroup_environment();
82
83 /* wait for the asynchronous auto-detachment.
84 * wait for no more than 5 sec and give up.
85 */
86 for (i = 0; i < ARRAY_SIZE(prog_ids); i++) {
87 for (attempts = 5; attempts >= 0; attempts--) {
88 int fd = bpf_prog_get_fd_by_id(prog_ids[i]);
89
90 if (fd < 0)
91 break;
92
93 /* don't leave the fd open */
94 close(fd);
95
96 if (CHECK_FAIL(!attempts))
97 goto err;
98
99 sleep(1);
100 }
101 }
102
103err:
104 for (i = 0; i < ARRAY_SIZE(allow_prog); i++)
105 if (allow_prog[i] >= 0)
106 close(allow_prog[i]);
107 if (cg)
108 close(cg);
109 free(ptr);
110 cleanup_cgroup_environment();
111}
112

source code of linux/tools/testing/selftests/bpf/prog_tests/cgroup_attach_autodetach.c