// SPDX-License-Identifier: GPL-2.0 #include #include "cgroup_helpers.h" #define PING_CMD "ping -q -c1 -w1 127.0.0.1 > /dev/null" static char bpf_log_buf[BPF_LOG_BUF_SIZE]; static int prog_load(void) { struct bpf_insn prog[] = { BPF_MOV64_IMM(BPF_REG_0, 1), /* r0 = 1 */ BPF_EXIT_INSN(), }; size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn); return bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB, prog, insns_cnt, "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE); } void test_cgroup_attach_autodetach(void) { __u32 duration = 0, prog_cnt = 4, attach_flags; int allow_prog[2] = {-1}; __u32 prog_ids[2] = {0}; void *ptr = NULL; int cg = 0, i; int attempts; for (i = 0; i < ARRAY_SIZE(allow_prog); i++) { allow_prog[i] = prog_load(); if (CHECK(allow_prog[i] < 0, "prog_load", "verifier output:\n%s\n-------\n", bpf_log_buf)) goto err; } if (CHECK_FAIL(setup_cgroup_environment())) goto err; /* create a cgroup, attach two programs and remember their ids */ cg = create_and_get_cgroup("/cg_autodetach"); if (CHECK_FAIL(cg < 0)) goto err; if (CHECK_FAIL(join_cgroup("/cg_autodetach"))) goto err; for (i = 0; i < ARRAY_SIZE(allow_prog); i++) if (CHECK(bpf_prog_attach(allow_prog[i], cg, BPF_CGROUP_INET_EGRESS, BPF_F_ALLOW_MULTI), "prog_attach", "prog[%d], errno=%d\n", i, errno)) goto err; /* make sure that programs are attached and run some traffic */ if (CHECK(bpf_prog_query(cg, BPF_CGROUP_INET_EGRESS, 0, &attach_flags, prog_ids, &prog_cnt), "prog_query", "errno=%d\n", errno)) goto err; if (CHECK_FAIL(system(PING_CMD))) goto err; /* allocate some memory (4Mb) to pin the original cgroup */ ptr = malloc(4 * (1 << 20)); if (CHECK_FAIL(!ptr)) goto err; /* close programs and cgroup fd */ for (i = 0; i < ARRAY_SIZE(allow_prog); i++) { close(allow_prog[i]); allow_prog[i] = -1; } close(cg); cg = 0; /* leave the cgroup and remove it. don't detach programs */ cleanup_cgroup_environment(); /* wait for the asynchronous auto-detachment. * wait for no more than 5 sec and give up. */ for (i = 0; i < ARRAY_SIZE(prog_ids); i++) { for (attempts = 5; attempts >= 0; attempts--) { int fd = bpf_prog_get_fd_by_id(prog_ids[i]); if (fd < 0) break; /* don't leave the fd open */ close(fd); if (CHECK_FAIL(!attempts)) goto err; sleep(1); } } err: for (i = 0; i < ARRAY_SIZE(allow_prog); i++) if (allow_prog[i] >= 0) close(allow_prog[i]); if (cg) close(cg); free(ptr); cleanup_cgroup_environment(); }