diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index 6ea83598246445e5ff24a5f01558b630ba08ea6a..49938d72cf639cbe12fcf98005b6d575beafb836 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -18,3 +18,4 @@ urandom_read test_btf test_sockmap test_lirc_mode2_user +get_cgroup_id_user diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 553d1816b77a5c409f92eae945fc22c58c9fb74e..607ed8729c06d107fa1fa7454c3efa00abfcff10 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -24,7 +24,7 @@ urandom_read: urandom_read.c # Order correspond to 'make run_tests' order TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \ test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \ - test_sock test_btf test_sockmap test_lirc_mode2_user + test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \ test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \ @@ -34,7 +34,8 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \ test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \ test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \ - test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o + test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \ + get_cgroup_id_kern.o # Order correspond to 'make run_tests' order TEST_PROGS := test_kmod.sh \ @@ -63,6 +64,7 @@ $(OUTPUT)/test_sock: cgroup_helpers.c $(OUTPUT)/test_sock_addr: cgroup_helpers.c $(OUTPUT)/test_sockmap: cgroup_helpers.c $(OUTPUT)/test_progs: trace_helpers.c +$(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c .PHONY: force diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index f3bca3ade0f3de74b4397db83f90628c96af6514..c87b4e052ce961e8a9f2a639a7d1bbcae9a828eb 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -176,3 +177,59 @@ int create_and_get_cgroup(char *path) return fd; } + +/** + * get_cgroup_id() - Get cgroup id for a particular cgroup path + * @path: The cgroup path, relative to the workdir, to join + * + * On success, it returns the cgroup id. On failure it returns 0, + * which is an invalid cgroup id. + * If there is a failure, it prints the error to stderr. + */ +unsigned long long get_cgroup_id(char *path) +{ + int dirfd, err, flags, mount_id, fhsize; + union { + unsigned long long cgid; + unsigned char raw_bytes[8]; + } id; + char cgroup_workdir[PATH_MAX + 1]; + struct file_handle *fhp, *fhp2; + unsigned long long ret = 0; + + format_cgroup_path(cgroup_workdir, path); + + dirfd = AT_FDCWD; + flags = 0; + fhsize = sizeof(*fhp); + fhp = calloc(1, fhsize); + if (!fhp) { + log_err("calloc"); + return 0; + } + err = name_to_handle_at(dirfd, cgroup_workdir, fhp, &mount_id, flags); + if (err >= 0 || fhp->handle_bytes != 8) { + log_err("name_to_handle_at"); + goto free_mem; + } + + fhsize = sizeof(struct file_handle) + fhp->handle_bytes; + fhp2 = realloc(fhp, fhsize); + if (!fhp2) { + log_err("realloc"); + goto free_mem; + } + err = name_to_handle_at(dirfd, cgroup_workdir, fhp2, &mount_id, flags); + fhp = fhp2; + if (err < 0) { + log_err("name_to_handle_at"); + goto free_mem; + } + + memcpy(id.raw_bytes, fhp->f_handle, 8); + ret = id.cgid; + +free_mem: + free(fhp); + return ret; +} diff --git a/tools/testing/selftests/bpf/cgroup_helpers.h b/tools/testing/selftests/bpf/cgroup_helpers.h index 06485e0002b3b797ccfaeadd9c38ce6b8706f61c..20a4a5dcd469019907341562c799b42a3bd95ddf 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.h +++ b/tools/testing/selftests/bpf/cgroup_helpers.h @@ -13,5 +13,6 @@ int create_and_get_cgroup(char *path); int join_cgroup(char *path); int setup_cgroup_environment(void); void cleanup_cgroup_environment(void); +unsigned long long get_cgroup_id(char *path); #endif diff --git a/tools/testing/selftests/bpf/get_cgroup_id_kern.c b/tools/testing/selftests/bpf/get_cgroup_id_kern.c new file mode 100644 index 0000000000000000000000000000000000000000..2cf8cb23f209505b7f13e650861fc4cdc71988b1 --- /dev/null +++ b/tools/testing/selftests/bpf/get_cgroup_id_kern.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include +#include "bpf_helpers.h" + +struct bpf_map_def SEC("maps") cg_ids = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(__u64), + .max_entries = 1, +}; + +SEC("tracepoint/syscalls/sys_enter_nanosleep") +int trace(void *ctx) +{ + __u32 key = 0; + __u64 *val; + + val = bpf_map_lookup_elem(&cg_ids, &key); + if (val) + *val = bpf_get_current_cgroup_id(); + + return 0; +} + +char _license[] SEC("license") = "GPL"; +__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */ diff --git a/tools/testing/selftests/bpf/get_cgroup_id_user.c b/tools/testing/selftests/bpf/get_cgroup_id_user.c new file mode 100644 index 0000000000000000000000000000000000000000..ea19a42e589405a0a6b3b1ee73207a48765047a1 --- /dev/null +++ b/tools/testing/selftests/bpf/get_cgroup_id_user.c @@ -0,0 +1,141 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "cgroup_helpers.h" +#include "bpf_rlimit.h" + +#define CHECK(condition, tag, format...) ({ \ + int __ret = !!(condition); \ + if (__ret) { \ + printf("%s:FAIL:%s ", __func__, tag); \ + printf(format); \ + } else { \ + printf("%s:PASS:%s\n", __func__, tag); \ + } \ + __ret; \ +}) + +static int bpf_find_map(const char *test, struct bpf_object *obj, + const char *name) +{ + struct bpf_map *map; + + map = bpf_object__find_map_by_name(obj, name); + if (!map) + return -1; + return bpf_map__fd(map); +} + +#define TEST_CGROUP "/test-bpf-get-cgroup-id/" + +int main(int argc, char **argv) +{ + const char *probe_name = "syscalls/sys_enter_nanosleep"; + const char *file = "get_cgroup_id_kern.o"; + int err, bytes, efd, prog_fd, pmu_fd; + struct perf_event_attr attr = {}; + int cgroup_fd, cgidmap_fd; + struct bpf_object *obj; + __u64 kcgid = 0, ucgid; + int exit_code = 1; + char buf[256]; + __u32 key = 0; + + err = setup_cgroup_environment(); + if (CHECK(err, "setup_cgroup_environment", "err %d errno %d\n", err, + errno)) + return 1; + + cgroup_fd = create_and_get_cgroup(TEST_CGROUP); + if (CHECK(cgroup_fd < 0, "create_and_get_cgroup", "err %d errno %d\n", + cgroup_fd, errno)) + goto cleanup_cgroup_env; + + err = join_cgroup(TEST_CGROUP); + if (CHECK(err, "join_cgroup", "err %d errno %d\n", err, errno)) + goto cleanup_cgroup_env; + + err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); + if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno)) + goto cleanup_cgroup_env; + + cgidmap_fd = bpf_find_map(__func__, obj, "cg_ids"); + if (CHECK(cgidmap_fd < 0, "bpf_find_map", "err %d errno %d\n", + cgidmap_fd, errno)) + goto close_prog; + + snprintf(buf, sizeof(buf), + "/sys/kernel/debug/tracing/events/%s/id", probe_name); + efd = open(buf, O_RDONLY, 0); + if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno)) + goto close_prog; + bytes = read(efd, buf, sizeof(buf)); + close(efd); + if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read", + "bytes %d errno %d\n", bytes, errno)) + goto close_prog; + + attr.config = strtol(buf, NULL, 0); + attr.type = PERF_TYPE_TRACEPOINT; + attr.sample_type = PERF_SAMPLE_RAW; + attr.sample_period = 1; + attr.wakeup_events = 1; + + /* attach to this pid so the all bpf invocations will be in the + * cgroup associated with this pid. + */ + pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd, + errno)) + goto close_prog; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); + if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err, + errno)) + goto close_pmu; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); + if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err, + errno)) + goto close_pmu; + + /* trigger some syscalls */ + sleep(1); + + err = bpf_map_lookup_elem(cgidmap_fd, &key, &kcgid); + if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno)) + goto close_pmu; + + ucgid = get_cgroup_id(TEST_CGROUP); + if (CHECK(kcgid != ucgid, "compare_cgroup_id", + "kern cgid %llx user cgid %llx", kcgid, ucgid)) + goto close_pmu; + + exit_code = 0; + printf("%s:PASS\n", argv[0]); + +close_pmu: + close(pmu_fd); +close_prog: + bpf_object__close(obj); +cleanup_cgroup_env: + cleanup_cgroup_environment(); + return exit_code; +}