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 
9 static char bpf_log_buf[BPF_LOG_BUF_SIZE];
10 
11 static 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 = sizeof(prog) / sizeof(struct bpf_insn);
18 
19 	return bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
20 			       prog, insns_cnt, "GPL", 0,
21 			       bpf_log_buf, BPF_LOG_BUF_SIZE);
22 }
23 
24 void 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 
103 err:
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