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

   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 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 }