helpers.h (3569B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Author: Aleksa Sarai <cyphar@cyphar.com> 4 * Copyright (C) 2018-2019 SUSE LLC. 5 */ 6 7#ifndef __RESOLVEAT_H__ 8#define __RESOLVEAT_H__ 9 10#define _GNU_SOURCE 11#include <stdint.h> 12#include <stdbool.h> 13#include <errno.h> 14#include <linux/types.h> 15#include "../kselftest.h" 16 17#define ARRAY_LEN(X) (sizeof (X) / sizeof (*(X))) 18#define BUILD_BUG_ON(e) ((void)(sizeof(struct { int:(-!!(e)); }))) 19 20#ifndef SYS_openat2 21#ifndef __NR_openat2 22#define __NR_openat2 437 23#endif /* __NR_openat2 */ 24#define SYS_openat2 __NR_openat2 25#endif /* SYS_openat2 */ 26 27/* 28 * Arguments for how openat2(2) should open the target path. If @resolve is 29 * zero, then openat2(2) operates very similarly to openat(2). 30 * 31 * However, unlike openat(2), unknown bits in @flags result in -EINVAL rather 32 * than being silently ignored. @mode must be zero unless one of {O_CREAT, 33 * O_TMPFILE} are set. 34 * 35 * @flags: O_* flags. 36 * @mode: O_CREAT/O_TMPFILE file mode. 37 * @resolve: RESOLVE_* flags. 38 */ 39struct open_how { 40 __u64 flags; 41 __u64 mode; 42 __u64 resolve; 43}; 44 45#define OPEN_HOW_SIZE_VER0 24 /* sizeof first published struct */ 46#define OPEN_HOW_SIZE_LATEST OPEN_HOW_SIZE_VER0 47 48bool needs_openat2(const struct open_how *how); 49 50#ifndef RESOLVE_IN_ROOT 51/* how->resolve flags for openat2(2). */ 52#define RESOLVE_NO_XDEV 0x01 /* Block mount-point crossings 53 (includes bind-mounts). */ 54#define RESOLVE_NO_MAGICLINKS 0x02 /* Block traversal through procfs-style 55 "magic-links". */ 56#define RESOLVE_NO_SYMLINKS 0x04 /* Block traversal through all symlinks 57 (implies OEXT_NO_MAGICLINKS) */ 58#define RESOLVE_BENEATH 0x08 /* Block "lexical" trickery like 59 "..", symlinks, and absolute 60 paths which escape the dirfd. */ 61#define RESOLVE_IN_ROOT 0x10 /* Make all jumps to "/" and ".." 62 be scoped inside the dirfd 63 (similar to chroot(2)). */ 64#endif /* RESOLVE_IN_ROOT */ 65 66#define E_func(func, ...) \ 67 do { \ 68 errno = 0; \ 69 if (func(__VA_ARGS__) < 0) \ 70 ksft_exit_fail_msg("%s:%d %s failed - errno:%d\n", \ 71 __FILE__, __LINE__, #func, errno); \ 72 } while (0) 73 74#define E_asprintf(...) E_func(asprintf, __VA_ARGS__) 75#define E_chmod(...) E_func(chmod, __VA_ARGS__) 76#define E_dup2(...) E_func(dup2, __VA_ARGS__) 77#define E_fchdir(...) E_func(fchdir, __VA_ARGS__) 78#define E_fstatat(...) E_func(fstatat, __VA_ARGS__) 79#define E_kill(...) E_func(kill, __VA_ARGS__) 80#define E_mkdirat(...) E_func(mkdirat, __VA_ARGS__) 81#define E_mount(...) E_func(mount, __VA_ARGS__) 82#define E_prctl(...) E_func(prctl, __VA_ARGS__) 83#define E_readlink(...) E_func(readlink, __VA_ARGS__) 84#define E_setresuid(...) E_func(setresuid, __VA_ARGS__) 85#define E_symlinkat(...) E_func(symlinkat, __VA_ARGS__) 86#define E_touchat(...) E_func(touchat, __VA_ARGS__) 87#define E_unshare(...) E_func(unshare, __VA_ARGS__) 88 89#define E_assert(expr, msg, ...) \ 90 do { \ 91 if (!(expr)) \ 92 ksft_exit_fail_msg("ASSERT(%s:%d) failed (%s): " msg "\n", \ 93 __FILE__, __LINE__, #expr, ##__VA_ARGS__); \ 94 } while (0) 95 96int raw_openat2(int dfd, const char *path, void *how, size_t size); 97int sys_openat2(int dfd, const char *path, struct open_how *how); 98int sys_openat(int dfd, const char *path, struct open_how *how); 99int sys_renameat2(int olddirfd, const char *oldpath, 100 int newdirfd, const char *newpath, unsigned int flags); 101 102int touchat(int dfd, const char *path); 103char *fdreadlink(int fd); 104bool fdequal(int fd, int dfd, const char *path); 105 106extern bool openat2_supported; 107 108#endif /* __RESOLVEAT_H__ */