diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/token.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/token.c | 1031 |
1 files changed, 0 insertions, 1031 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/token.c b/tools/testing/selftests/bpf/prog_tests/token.c deleted file mode 100644 index b5dce630e0e1..000000000000 --- a/tools/testing/selftests/bpf/prog_tests/token.c +++ /dev/null @@ -1,1031 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ -#define _GNU_SOURCE -#include <test_progs.h> -#include <bpf/btf.h> -#include "cap_helpers.h" -#include <fcntl.h> -#include <sched.h> -#include <signal.h> -#include <unistd.h> -#include <linux/filter.h> -#include <linux/unistd.h> -#include <linux/mount.h> -#include <sys/socket.h> -#include <sys/stat.h> -#include <sys/syscall.h> -#include <sys/un.h> -#include "priv_map.skel.h" -#include "priv_prog.skel.h" -#include "dummy_st_ops_success.skel.h" - -static inline int sys_mount(const char *dev_name, const char *dir_name, - const char *type, unsigned long flags, - const void *data) -{ - return syscall(__NR_mount, dev_name, dir_name, type, flags, data); -} - -static inline int sys_fsopen(const char *fsname, unsigned flags) -{ - return syscall(__NR_fsopen, fsname, flags); -} - -static inline int sys_fspick(int dfd, const char *path, unsigned flags) -{ - return syscall(__NR_fspick, dfd, path, flags); -} - -static inline int sys_fsconfig(int fs_fd, unsigned cmd, const char *key, const void *val, int aux) -{ - return syscall(__NR_fsconfig, fs_fd, cmd, key, val, aux); -} - -static inline int sys_fsmount(int fs_fd, unsigned flags, unsigned ms_flags) -{ - return syscall(__NR_fsmount, fs_fd, flags, ms_flags); -} - -static inline int sys_move_mount(int from_dfd, const char *from_path, - int to_dfd, const char *to_path, - unsigned flags) -{ - return syscall(__NR_move_mount, from_dfd, from_path, to_dfd, to_path, flags); -} - -static int drop_priv_caps(__u64 *old_caps) -{ - return cap_disable_effective((1ULL << CAP_BPF) | - (1ULL << CAP_PERFMON) | - (1ULL << CAP_NET_ADMIN) | - (1ULL << CAP_SYS_ADMIN), old_caps); -} - -static int restore_priv_caps(__u64 old_caps) -{ - return cap_enable_effective(old_caps, NULL); -} - -static int set_delegate_mask(int fs_fd, const char *key, __u64 mask, const char *mask_str) -{ - char buf[32]; - int err; - - if (!mask_str) { - if (mask == ~0ULL) { - mask_str = "any"; - } else { - snprintf(buf, sizeof(buf), "0x%llx", (unsigned long long)mask); - mask_str = buf; - } - } - - err = sys_fsconfig(fs_fd, FSCONFIG_SET_STRING, key, - mask_str, 0); - if (err < 0) - err = -errno; - return err; -} - -#define zclose(fd) do { if (fd >= 0) close(fd); fd = -1; } while (0) - -struct bpffs_opts { - __u64 cmds; - __u64 maps; - __u64 progs; - __u64 attachs; - const char *cmds_str; - const char *maps_str; - const char *progs_str; - const char *attachs_str; -}; - -static int create_bpffs_fd(void) -{ - int fs_fd; - - /* create VFS context */ - fs_fd = sys_fsopen("bpf", 0); - ASSERT_GE(fs_fd, 0, "fs_fd"); - - return fs_fd; -} - -static int materialize_bpffs_fd(int fs_fd, struct bpffs_opts *opts) -{ - int mnt_fd, err; - - /* set up token delegation mount options */ - err = set_delegate_mask(fs_fd, "delegate_cmds", opts->cmds, opts->cmds_str); - if (!ASSERT_OK(err, "fs_cfg_cmds")) - return err; - err = set_delegate_mask(fs_fd, "delegate_maps", opts->maps, opts->maps_str); - if (!ASSERT_OK(err, "fs_cfg_maps")) - return err; - err = set_delegate_mask(fs_fd, "delegate_progs", opts->progs, opts->progs_str); - if (!ASSERT_OK(err, "fs_cfg_progs")) - return err; - err = set_delegate_mask(fs_fd, "delegate_attachs", opts->attachs, opts->attachs_str); - if (!ASSERT_OK(err, "fs_cfg_attachs")) - return err; - - /* instantiate FS object */ - err = sys_fsconfig(fs_fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0); - if (err < 0) - return -errno; - - /* create O_PATH fd for detached mount */ - mnt_fd = sys_fsmount(fs_fd, 0, 0); - if (err < 0) - return -errno; - - return mnt_fd; -} - -/* send FD over Unix domain (AF_UNIX) socket */ -static int sendfd(int sockfd, int fd) -{ - struct msghdr msg = {}; - struct cmsghdr *cmsg; - int fds[1] = { fd }, err; - char iobuf[1]; - struct iovec io = { - .iov_base = iobuf, - .iov_len = sizeof(iobuf), - }; - union { - char buf[CMSG_SPACE(sizeof(fds))]; - struct cmsghdr align; - } u; - - msg.msg_iov = &io; - msg.msg_iovlen = 1; - msg.msg_control = u.buf; - msg.msg_controllen = sizeof(u.buf); - cmsg = CMSG_FIRSTHDR(&msg); - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - cmsg->cmsg_len = CMSG_LEN(sizeof(fds)); - memcpy(CMSG_DATA(cmsg), fds, sizeof(fds)); - - err = sendmsg(sockfd, &msg, 0); - if (err < 0) - err = -errno; - if (!ASSERT_EQ(err, 1, "sendmsg")) - return -EINVAL; - - return 0; -} - -/* receive FD over Unix domain (AF_UNIX) socket */ -static int recvfd(int sockfd, int *fd) -{ - struct msghdr msg = {}; - struct cmsghdr *cmsg; - int fds[1], err; - char iobuf[1]; - struct iovec io = { - .iov_base = iobuf, - .iov_len = sizeof(iobuf), - }; - union { - char buf[CMSG_SPACE(sizeof(fds))]; - struct cmsghdr align; - } u; - - msg.msg_iov = &io; - msg.msg_iovlen = 1; - msg.msg_control = u.buf; - msg.msg_controllen = sizeof(u.buf); - - err = recvmsg(sockfd, &msg, 0); - if (err < 0) - err = -errno; - if (!ASSERT_EQ(err, 1, "recvmsg")) - return -EINVAL; - - cmsg = CMSG_FIRSTHDR(&msg); - if (!ASSERT_OK_PTR(cmsg, "cmsg_null") || - !ASSERT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(fds)), "cmsg_len") || - !ASSERT_EQ(cmsg->cmsg_level, SOL_SOCKET, "cmsg_level") || - !ASSERT_EQ(cmsg->cmsg_type, SCM_RIGHTS, "cmsg_type")) - return -EINVAL; - - memcpy(fds, CMSG_DATA(cmsg), sizeof(fds)); - *fd = fds[0]; - - return 0; -} - -static ssize_t write_nointr(int fd, const void *buf, size_t count) -{ - ssize_t ret; - - do { - ret = write(fd, buf, count); - } while (ret < 0 && errno == EINTR); - - return ret; -} - -static int write_file(const char *path, const void *buf, size_t count) -{ - int fd; - ssize_t ret; - - fd = open(path, O_WRONLY | O_CLOEXEC | O_NOCTTY | O_NOFOLLOW); - if (fd < 0) - return -1; - - ret = write_nointr(fd, buf, count); - close(fd); - if (ret < 0 || (size_t)ret != count) - return -1; - - return 0; -} - -static int create_and_enter_userns(void) -{ - uid_t uid; - gid_t gid; - char map[100]; - - uid = getuid(); - gid = getgid(); - - if (unshare(CLONE_NEWUSER)) - return -1; - - if (write_file("/proc/self/setgroups", "deny", sizeof("deny") - 1) && - errno != ENOENT) - return -1; - - snprintf(map, sizeof(map), "0 %d 1", uid); - if (write_file("/proc/self/uid_map", map, strlen(map))) - return -1; - - - snprintf(map, sizeof(map), "0 %d 1", gid); - if (write_file("/proc/self/gid_map", map, strlen(map))) - return -1; - - if (setgid(0)) - return -1; - - if (setuid(0)) - return -1; - - return 0; -} - -typedef int (*child_callback_fn)(int); - -static void child(int sock_fd, struct bpffs_opts *opts, child_callback_fn callback) -{ - LIBBPF_OPTS(bpf_map_create_opts, map_opts); - int mnt_fd = -1, fs_fd = -1, err = 0, bpffs_fd = -1; - - /* setup userns with root mappings */ - err = create_and_enter_userns(); - if (!ASSERT_OK(err, "create_and_enter_userns")) - goto cleanup; - - /* setup mountns to allow creating BPF FS (fsopen("bpf")) from unpriv process */ - err = unshare(CLONE_NEWNS); - if (!ASSERT_OK(err, "create_mountns")) - goto cleanup; - - err = sys_mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0); - if (!ASSERT_OK(err, "remount_root")) - goto cleanup; - - fs_fd = create_bpffs_fd(); - if (!ASSERT_GE(fs_fd, 0, "create_bpffs_fd")) { - err = -EINVAL; - goto cleanup; - } - - /* ensure unprivileged child cannot set delegation options */ - err = set_delegate_mask(fs_fd, "delegate_cmds", 0x1, NULL); - ASSERT_EQ(err, -EPERM, "delegate_cmd_eperm"); - err = set_delegate_mask(fs_fd, "delegate_maps", 0x1, NULL); - ASSERT_EQ(err, -EPERM, "delegate_maps_eperm"); - err = set_delegate_mask(fs_fd, "delegate_progs", 0x1, NULL); - ASSERT_EQ(err, -EPERM, "delegate_progs_eperm"); - err = set_delegate_mask(fs_fd, "delegate_attachs", 0x1, NULL); - ASSERT_EQ(err, -EPERM, "delegate_attachs_eperm"); - - /* pass BPF FS context object to parent */ - err = sendfd(sock_fd, fs_fd); - if (!ASSERT_OK(err, "send_fs_fd")) - goto cleanup; - zclose(fs_fd); - - /* avoid mucking around with mount namespaces and mounting at - * well-known path, just get detach-mounted BPF FS fd back from parent - */ - err = recvfd(sock_fd, &mnt_fd); - if (!ASSERT_OK(err, "recv_mnt_fd")) - goto cleanup; - - /* try to fspick() BPF FS and try to add some delegation options */ - fs_fd = sys_fspick(mnt_fd, "", FSPICK_EMPTY_PATH); - if (!ASSERT_GE(fs_fd, 0, "bpffs_fspick")) { - err = -EINVAL; - goto cleanup; - } - - /* ensure unprivileged child cannot reconfigure to set delegation options */ - err = set_delegate_mask(fs_fd, "delegate_cmds", 0, "any"); - if (!ASSERT_EQ(err, -EPERM, "delegate_cmd_eperm_reconfig")) { - err = -EINVAL; - goto cleanup; - } - err = set_delegate_mask(fs_fd, "delegate_maps", 0, "any"); - if (!ASSERT_EQ(err, -EPERM, "delegate_maps_eperm_reconfig")) { - err = -EINVAL; - goto cleanup; - } - err = set_delegate_mask(fs_fd, "delegate_progs", 0, "any"); - if (!ASSERT_EQ(err, -EPERM, "delegate_progs_eperm_reconfig")) { - err = -EINVAL; - goto cleanup; - } - err = set_delegate_mask(fs_fd, "delegate_attachs", 0, "any"); - if (!ASSERT_EQ(err, -EPERM, "delegate_attachs_eperm_reconfig")) { - err = -EINVAL; - goto cleanup; - } - zclose(fs_fd); - - bpffs_fd = openat(mnt_fd, ".", 0, O_RDWR); - if (!ASSERT_GE(bpffs_fd, 0, "bpffs_open")) { - err = -EINVAL; - goto cleanup; - } - - /* do custom test logic with customly set up BPF FS instance */ - err = callback(bpffs_fd); - if (!ASSERT_OK(err, "test_callback")) - goto cleanup; - - err = 0; -cleanup: - zclose(sock_fd); - zclose(mnt_fd); - zclose(fs_fd); - zclose(bpffs_fd); - - exit(-err); -} - -static int wait_for_pid(pid_t pid) -{ - int status, ret; - -again: - ret = waitpid(pid, &status, 0); - if (ret == -1) { - if (errno == EINTR) - goto again; - - return -1; - } - - if (!WIFEXITED(status)) - return -1; - - return WEXITSTATUS(status); -} - -static void parent(int child_pid, struct bpffs_opts *bpffs_opts, int sock_fd) -{ - int fs_fd = -1, mnt_fd = -1, err; - - err = recvfd(sock_fd, &fs_fd); - if (!ASSERT_OK(err, "recv_bpffs_fd")) - goto cleanup; - - mnt_fd = materialize_bpffs_fd(fs_fd, bpffs_opts); - if (!ASSERT_GE(mnt_fd, 0, "materialize_bpffs_fd")) { - err = -EINVAL; - goto cleanup; - } - zclose(fs_fd); - - /* pass BPF FS context object to parent */ - err = sendfd(sock_fd, mnt_fd); - if (!ASSERT_OK(err, "send_mnt_fd")) - goto cleanup; - zclose(mnt_fd); - - err = wait_for_pid(child_pid); - ASSERT_OK(err, "waitpid_child"); - -cleanup: - zclose(sock_fd); - zclose(fs_fd); - zclose(mnt_fd); - - if (child_pid > 0) - (void)kill(child_pid, SIGKILL); -} - -static void subtest_userns(struct bpffs_opts *bpffs_opts, child_callback_fn cb) -{ - int sock_fds[2] = { -1, -1 }; - int child_pid = 0, err; - - err = socketpair(AF_UNIX, SOCK_STREAM, 0, sock_fds); - if (!ASSERT_OK(err, "socketpair")) - goto cleanup; - - child_pid = fork(); - if (!ASSERT_GE(child_pid, 0, "fork")) - goto cleanup; - - if (child_pid == 0) { - zclose(sock_fds[0]); - return child(sock_fds[1], bpffs_opts, cb); - - } else { - zclose(sock_fds[1]); - return parent(child_pid, bpffs_opts, sock_fds[0]); - } - -cleanup: - zclose(sock_fds[0]); - zclose(sock_fds[1]); - if (child_pid > 0) - (void)kill(child_pid, SIGKILL); -} - -static int userns_map_create(int mnt_fd) -{ - LIBBPF_OPTS(bpf_map_create_opts, map_opts); - int err, token_fd = -1, map_fd = -1; - __u64 old_caps = 0; - - /* create BPF token from BPF FS mount */ - token_fd = bpf_token_create(mnt_fd, NULL); - if (!ASSERT_GT(token_fd, 0, "token_create")) { - err = -EINVAL; - goto cleanup; - } - - /* while inside non-init userns, we need both a BPF token *and* - * CAP_BPF inside current userns to create privileged map; let's test - * that neither BPF token alone nor namespaced CAP_BPF is sufficient - */ - err = drop_priv_caps(&old_caps); - if (!ASSERT_OK(err, "drop_caps")) - goto cleanup; - - /* no token, no CAP_BPF -> fail */ - map_opts.token_fd = 0; - map_fd = bpf_map_create(BPF_MAP_TYPE_STACK, "wo_token_wo_bpf", 0, 8, 1, &map_opts); - if (!ASSERT_LT(map_fd, 0, "stack_map_wo_token_wo_cap_bpf_should_fail")) { - err = -EINVAL; - goto cleanup; - } - - /* token without CAP_BPF -> fail */ - map_opts.token_fd = token_fd; - map_fd = bpf_map_create(BPF_MAP_TYPE_STACK, "w_token_wo_bpf", 0, 8, 1, &map_opts); - if (!ASSERT_LT(map_fd, 0, "stack_map_w_token_wo_cap_bpf_should_fail")) { - err = -EINVAL; - goto cleanup; - } - - /* get back effective local CAP_BPF (and CAP_SYS_ADMIN) */ - err = restore_priv_caps(old_caps); - if (!ASSERT_OK(err, "restore_caps")) - goto cleanup; - - /* CAP_BPF without token -> fail */ - map_opts.token_fd = 0; - map_fd = bpf_map_create(BPF_MAP_TYPE_STACK, "wo_token_w_bpf", 0, 8, 1, &map_opts); - if (!ASSERT_LT(map_fd, 0, "stack_map_wo_token_w_cap_bpf_should_fail")) { - err = -EINVAL; - goto cleanup; - } - - /* finally, namespaced CAP_BPF + token -> success */ - map_opts.token_fd = token_fd; - map_fd = bpf_map_create(BPF_MAP_TYPE_STACK, "w_token_w_bpf", 0, 8, 1, &map_opts); - if (!ASSERT_GT(map_fd, 0, "stack_map_w_token_w_cap_bpf")) { - err = -EINVAL; - goto cleanup; - } - -cleanup: - zclose(token_fd); - zclose(map_fd); - return err; -} - -static int userns_btf_load(int mnt_fd) -{ - LIBBPF_OPTS(bpf_btf_load_opts, btf_opts); - int err, token_fd = -1, btf_fd = -1; - const void *raw_btf_data; - struct btf *btf = NULL; - __u32 raw_btf_size; - __u64 old_caps = 0; - - /* create BPF token from BPF FS mount */ - token_fd = bpf_token_create(mnt_fd, NULL); - if (!ASSERT_GT(token_fd, 0, "token_create")) { - err = -EINVAL; - goto cleanup; - } - - /* while inside non-init userns, we need both a BPF token *and* - * CAP_BPF inside current userns to create privileged map; let's test - * that neither BPF token alone nor namespaced CAP_BPF is sufficient - */ - err = drop_priv_caps(&old_caps); - if (!ASSERT_OK(err, "drop_caps")) - goto cleanup; - - /* setup a trivial BTF data to load to the kernel */ - btf = btf__new_empty(); - if (!ASSERT_OK_PTR(btf, "empty_btf")) - goto cleanup; - - ASSERT_GT(btf__add_int(btf, "int", 4, 0), 0, "int_type"); - - raw_btf_data = btf__raw_data(btf, &raw_btf_size); - if (!ASSERT_OK_PTR(raw_btf_data, "raw_btf_data")) - goto cleanup; - - /* no token + no CAP_BPF -> failure */ - btf_opts.token_fd = 0; - btf_fd = bpf_btf_load(raw_btf_data, raw_btf_size, &btf_opts); - if (!ASSERT_LT(btf_fd, 0, "no_token_no_cap_should_fail")) - goto cleanup; - - /* token + no CAP_BPF -> failure */ - btf_opts.token_fd = token_fd; - btf_fd = bpf_btf_load(raw_btf_data, raw_btf_size, &btf_opts); - if (!ASSERT_LT(btf_fd, 0, "token_no_cap_should_fail")) - goto cleanup; - - /* get back effective local CAP_BPF (and CAP_SYS_ADMIN) */ - err = restore_priv_caps(old_caps); - if (!ASSERT_OK(err, "restore_caps")) - goto cleanup; - - /* token + CAP_BPF -> success */ - btf_opts.token_fd = token_fd; - btf_fd = bpf_btf_load(raw_btf_data, raw_btf_size, &btf_opts); - if (!ASSERT_GT(btf_fd, 0, "token_and_cap_success")) - goto cleanup; - - err = 0; -cleanup: - btf__free(btf); - zclose(btf_fd); - zclose(token_fd); - return err; -} - -static int userns_prog_load(int mnt_fd) -{ - LIBBPF_OPTS(bpf_prog_load_opts, prog_opts); - int err, token_fd = -1, prog_fd = -1; - struct bpf_insn insns[] = { - /* bpf_jiffies64() requires CAP_BPF */ - BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64), - /* bpf_get_current_task() requires CAP_PERFMON */ - BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_current_task), - /* r0 = 0; exit; */ - BPF_MOV64_IMM(BPF_REG_0, 0), - BPF_EXIT_INSN(), - }; - size_t insn_cnt = ARRAY_SIZE(insns); - __u64 old_caps = 0; - - /* create BPF token from BPF FS mount */ - token_fd = bpf_token_create(mnt_fd, NULL); - if (!ASSERT_GT(token_fd, 0, "token_create")) { - err = -EINVAL; - goto cleanup; - } - - /* validate we can successfully load BPF program with token; this - * being XDP program (CAP_NET_ADMIN) using bpf_jiffies64() (CAP_BPF) - * and bpf_get_current_task() (CAP_PERFMON) helpers validates we have - * BPF token wired properly in a bunch of places in the kernel - */ - prog_opts.token_fd = token_fd; - prog_opts.expected_attach_type = BPF_XDP; - prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, "token_prog", "GPL", - insns, insn_cnt, &prog_opts); - if (!ASSERT_GT(prog_fd, 0, "prog_fd")) { - err = -EPERM; - goto cleanup; - } - - /* no token + caps -> failure */ - prog_opts.token_fd = 0; - prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, "token_prog", "GPL", - insns, insn_cnt, &prog_opts); - if (!ASSERT_EQ(prog_fd, -EPERM, "prog_fd_eperm")) { - err = -EPERM; - goto cleanup; - } - - err = drop_priv_caps(&old_caps); - if (!ASSERT_OK(err, "drop_caps")) - goto cleanup; - - /* no caps + token -> failure */ - prog_opts.token_fd = token_fd; - prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, "token_prog", "GPL", - insns, insn_cnt, &prog_opts); - if (!ASSERT_EQ(prog_fd, -EPERM, "prog_fd_eperm")) { - err = -EPERM; - goto cleanup; - } - - /* no caps + no token -> definitely a failure */ - prog_opts.token_fd = 0; - prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, "token_prog", "GPL", - insns, insn_cnt, &prog_opts); - if (!ASSERT_EQ(prog_fd, -EPERM, "prog_fd_eperm")) { - err = -EPERM; - goto cleanup; - } - - err = 0; -cleanup: - zclose(prog_fd); - zclose(token_fd); - return err; -} - -static int userns_obj_priv_map(int mnt_fd) -{ - LIBBPF_OPTS(bpf_object_open_opts, opts); - char buf[256]; - struct priv_map *skel; - int err, token_fd; - - skel = priv_map__open_and_load(); - if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load")) { - priv_map__destroy(skel); - return -EINVAL; - } - - /* use bpf_token_path to provide BPF FS path */ - snprintf(buf, sizeof(buf), "/proc/self/fd/%d", mnt_fd); - opts.bpf_token_path = buf; - skel = priv_map__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_token_path_open")) - return -EINVAL; - - err = priv_map__load(skel); - priv_map__destroy(skel); - if (!ASSERT_OK(err, "obj_token_path_load")) - return -EINVAL; - - /* create token and pass it through bpf_token_fd */ - token_fd = bpf_token_create(mnt_fd, NULL); - if (!ASSERT_GT(token_fd, 0, "create_token")) - return -EINVAL; - - opts.bpf_token_path = NULL; - opts.bpf_token_fd = token_fd; - skel = priv_map__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_token_fd_open")) - return -EINVAL; - - /* we can close our token FD, bpf_object owns dup()'ed FD now */ - close(token_fd); - - err = priv_map__load(skel); - priv_map__destroy(skel); - if (!ASSERT_OK(err, "obj_token_fd_load")) - return -EINVAL; - - return 0; -} - -static int userns_obj_priv_prog(int mnt_fd) -{ - LIBBPF_OPTS(bpf_object_open_opts, opts); - char buf[256]; - struct priv_prog *skel; - int err; - - skel = priv_prog__open_and_load(); - if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load")) { - priv_prog__destroy(skel); - return -EINVAL; - } - - /* use bpf_token_path to provide BPF FS path */ - snprintf(buf, sizeof(buf), "/proc/self/fd/%d", mnt_fd); - opts.bpf_token_path = buf; - skel = priv_prog__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_token_path_open")) - return -EINVAL; - - err = priv_prog__load(skel); - priv_prog__destroy(skel); - if (!ASSERT_OK(err, "obj_token_path_load")) - return -EINVAL; - - return 0; -} - -/* this test is called with BPF FS that doesn't delegate BPF_BTF_LOAD command, - * which should cause struct_ops application to fail, as BTF won't be uploaded - * into the kernel, even if STRUCT_OPS programs themselves are allowed - */ -static int validate_struct_ops_load(int mnt_fd, bool expect_success) -{ - LIBBPF_OPTS(bpf_object_open_opts, opts); - char buf[256]; - struct dummy_st_ops_success *skel; - int err; - - snprintf(buf, sizeof(buf), "/proc/self/fd/%d", mnt_fd); - opts.bpf_token_path = buf; - skel = dummy_st_ops_success__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_token_path_open")) - return -EINVAL; - - err = dummy_st_ops_success__load(skel); - dummy_st_ops_success__destroy(skel); - if (expect_success) { - if (!ASSERT_OK(err, "obj_token_path_load")) - return -EINVAL; - } else /* expect failure */ { - if (!ASSERT_ERR(err, "obj_token_path_load")) - return -EINVAL; - } - - return 0; -} - -static int userns_obj_priv_btf_fail(int mnt_fd) -{ - return validate_struct_ops_load(mnt_fd, false /* should fail */); -} - -static int userns_obj_priv_btf_success(int mnt_fd) -{ - return validate_struct_ops_load(mnt_fd, true /* should succeed */); -} - -#define TOKEN_ENVVAR "LIBBPF_BPF_TOKEN_PATH" -#define TOKEN_BPFFS_CUSTOM "/bpf-token-fs" - -static int userns_obj_priv_implicit_token(int mnt_fd) -{ - LIBBPF_OPTS(bpf_object_open_opts, opts); - struct dummy_st_ops_success *skel; - int err; - - /* before we mount BPF FS with token delegation, struct_ops skeleton - * should fail to load - */ - skel = dummy_st_ops_success__open_and_load(); - if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load")) { - dummy_st_ops_success__destroy(skel); - return -EINVAL; - } - - /* mount custom BPF FS over /sys/fs/bpf so that libbpf can create BPF - * token automatically and implicitly - */ - err = sys_move_mount(mnt_fd, "", AT_FDCWD, "/sys/fs/bpf", MOVE_MOUNT_F_EMPTY_PATH); - if (!ASSERT_OK(err, "move_mount_bpffs")) - return -EINVAL; - - /* disable implicit BPF token creation by setting - * LIBBPF_BPF_TOKEN_PATH envvar to empty value, load should fail - */ - err = setenv(TOKEN_ENVVAR, "", 1 /*overwrite*/); - if (!ASSERT_OK(err, "setenv_token_path")) - return -EINVAL; - skel = dummy_st_ops_success__open_and_load(); - if (!ASSERT_ERR_PTR(skel, "obj_token_envvar_disabled_load")) { - unsetenv(TOKEN_ENVVAR); - dummy_st_ops_success__destroy(skel); - return -EINVAL; - } - unsetenv(TOKEN_ENVVAR); - - /* now the same struct_ops skeleton should succeed thanks to libppf - * creating BPF token from /sys/fs/bpf mount point - */ - skel = dummy_st_ops_success__open_and_load(); - if (!ASSERT_OK_PTR(skel, "obj_implicit_token_load")) - return -EINVAL; - - dummy_st_ops_success__destroy(skel); - - /* now disable implicit token through empty bpf_token_path, should fail */ - opts.bpf_token_path = ""; - skel = dummy_st_ops_success__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_empty_token_path_open")) - return -EINVAL; - - err = dummy_st_ops_success__load(skel); - dummy_st_ops_success__destroy(skel); - if (!ASSERT_ERR(err, "obj_empty_token_path_load")) - return -EINVAL; - - /* now disable implicit token through negative bpf_token_fd, should fail */ - opts.bpf_token_path = NULL; - opts.bpf_token_fd = -1; - skel = dummy_st_ops_success__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_neg_token_fd_open")) - return -EINVAL; - - err = dummy_st_ops_success__load(skel); - dummy_st_ops_success__destroy(skel); - if (!ASSERT_ERR(err, "obj_neg_token_fd_load")) - return -EINVAL; - - return 0; -} - -static int userns_obj_priv_implicit_token_envvar(int mnt_fd) -{ - LIBBPF_OPTS(bpf_object_open_opts, opts); - struct dummy_st_ops_success *skel; - int err; - - /* before we mount BPF FS with token delegation, struct_ops skeleton - * should fail to load - */ - skel = dummy_st_ops_success__open_and_load(); - if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load")) { - dummy_st_ops_success__destroy(skel); - return -EINVAL; - } - - /* mount custom BPF FS over custom location, so libbpf can't create - * BPF token implicitly, unless pointed to it through - * LIBBPF_BPF_TOKEN_PATH envvar - */ - rmdir(TOKEN_BPFFS_CUSTOM); - if (!ASSERT_OK(mkdir(TOKEN_BPFFS_CUSTOM, 0777), "mkdir_bpffs_custom")) - goto err_out; - err = sys_move_mount(mnt_fd, "", AT_FDCWD, TOKEN_BPFFS_CUSTOM, MOVE_MOUNT_F_EMPTY_PATH); - if (!ASSERT_OK(err, "move_mount_bpffs")) - goto err_out; - - /* even though we have BPF FS with delegation, it's not at default - * /sys/fs/bpf location, so we still fail to load until envvar is set up - */ - skel = dummy_st_ops_success__open_and_load(); - if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load2")) { - dummy_st_ops_success__destroy(skel); - goto err_out; - } - - err = setenv(TOKEN_ENVVAR, TOKEN_BPFFS_CUSTOM, 1 /*overwrite*/); - if (!ASSERT_OK(err, "setenv_token_path")) - goto err_out; - - /* now the same struct_ops skeleton should succeed thanks to libppf - * creating BPF token from custom mount point - */ - skel = dummy_st_ops_success__open_and_load(); - if (!ASSERT_OK_PTR(skel, "obj_implicit_token_load")) - goto err_out; - - dummy_st_ops_success__destroy(skel); - - /* now disable implicit token through empty bpf_token_path, envvar - * will be ignored, should fail - */ - opts.bpf_token_path = ""; - skel = dummy_st_ops_success__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_empty_token_path_open")) - goto err_out; - - err = dummy_st_ops_success__load(skel); - dummy_st_ops_success__destroy(skel); - if (!ASSERT_ERR(err, "obj_empty_token_path_load")) - goto err_out; - - /* now disable implicit token through negative bpf_token_fd, envvar - * will be ignored, should fail - */ - opts.bpf_token_path = NULL; - opts.bpf_token_fd = -1; - skel = dummy_st_ops_success__open_opts(&opts); - if (!ASSERT_OK_PTR(skel, "obj_neg_token_fd_open")) - goto err_out; - - err = dummy_st_ops_success__load(skel); - dummy_st_ops_success__destroy(skel); - if (!ASSERT_ERR(err, "obj_neg_token_fd_load")) - goto err_out; - - rmdir(TOKEN_BPFFS_CUSTOM); - unsetenv(TOKEN_ENVVAR); - return 0; -err_out: - rmdir(TOKEN_BPFFS_CUSTOM); - unsetenv(TOKEN_ENVVAR); - return -EINVAL; -} - -#define bit(n) (1ULL << (n)) - -void test_token(void) -{ - if (test__start_subtest("map_token")) { - struct bpffs_opts opts = { - .cmds_str = "map_create", - .maps_str = "stack", - }; - - subtest_userns(&opts, userns_map_create); - } - if (test__start_subtest("btf_token")) { - struct bpffs_opts opts = { - .cmds = 1ULL << BPF_BTF_LOAD, - }; - - subtest_userns(&opts, userns_btf_load); - } - if (test__start_subtest("prog_token")) { - struct bpffs_opts opts = { - .cmds_str = "PROG_LOAD", - .progs_str = "XDP", - .attachs_str = "xdp", - }; - - subtest_userns(&opts, userns_prog_load); - } - if (test__start_subtest("obj_priv_map")) { - struct bpffs_opts opts = { - .cmds = bit(BPF_MAP_CREATE), - .maps = bit(BPF_MAP_TYPE_QUEUE), - }; - - subtest_userns(&opts, userns_obj_priv_map); - } - if (test__start_subtest("obj_priv_prog")) { - struct bpffs_opts opts = { - .cmds = bit(BPF_PROG_LOAD), - .progs = bit(BPF_PROG_TYPE_KPROBE), - .attachs = ~0ULL, - }; - - subtest_userns(&opts, userns_obj_priv_prog); - } - if (test__start_subtest("obj_priv_btf_fail")) { - struct bpffs_opts opts = { - /* disallow BTF loading */ - .cmds = bit(BPF_MAP_CREATE) | bit(BPF_PROG_LOAD), - .maps = bit(BPF_MAP_TYPE_STRUCT_OPS), - .progs = bit(BPF_PROG_TYPE_STRUCT_OPS), - .attachs = ~0ULL, - }; - - subtest_userns(&opts, userns_obj_priv_btf_fail); - } - if (test__start_subtest("obj_priv_btf_success")) { - struct bpffs_opts opts = { - /* allow BTF loading */ - .cmds = bit(BPF_BTF_LOAD) | bit(BPF_MAP_CREATE) | bit(BPF_PROG_LOAD), - .maps = bit(BPF_MAP_TYPE_STRUCT_OPS), - .progs = bit(BPF_PROG_TYPE_STRUCT_OPS), - .attachs = ~0ULL, - }; - - subtest_userns(&opts, userns_obj_priv_btf_success); - } - if (test__start_subtest("obj_priv_implicit_token")) { - struct bpffs_opts opts = { - /* allow BTF loading */ - .cmds = bit(BPF_BTF_LOAD) | bit(BPF_MAP_CREATE) | bit(BPF_PROG_LOAD), - .maps = bit(BPF_MAP_TYPE_STRUCT_OPS), - .progs = bit(BPF_PROG_TYPE_STRUCT_OPS), - .attachs = ~0ULL, - }; - - subtest_userns(&opts, userns_obj_priv_implicit_token); - } - if (test__start_subtest("obj_priv_implicit_token_envvar")) { - struct bpffs_opts opts = { - /* allow BTF loading */ - .cmds = bit(BPF_BTF_LOAD) | bit(BPF_MAP_CREATE) | bit(BPF_PROG_LOAD), - .maps = bit(BPF_MAP_TYPE_STRUCT_OPS), - .progs = bit(BPF_PROG_TYPE_STRUCT_OPS), - .attachs = ~0ULL, - }; - - subtest_userns(&opts, userns_obj_priv_implicit_token_envvar); - } -} |