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Diffstat (limited to 'src/basic/chase.h')
| -rw-r--r-- | src/basic/chase.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/basic/chase.h b/src/basic/chase.h new file mode 100644 index 0000000..cfc714b --- /dev/null +++ b/src/basic/chase.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <dirent.h> +#include <stdio.h> + +#include "stat-util.h" + +typedef enum ChaseFlags { + CHASE_PREFIX_ROOT = 1 << 0, /* The specified path will be prefixed by the specified root before beginning the iteration */ + CHASE_NONEXISTENT = 1 << 1, /* It's OK if the path doesn't actually exist. */ + CHASE_NO_AUTOFS = 1 << 2, /* Return -EREMOTE if autofs mount point found */ + CHASE_SAFE = 1 << 3, /* Return -EPERM if we ever traverse from unprivileged to privileged files or directories */ + CHASE_TRAIL_SLASH = 1 << 4, /* Any trailing slash will be preserved */ + CHASE_STEP = 1 << 5, /* Just execute a single step of the normalization */ + CHASE_NOFOLLOW = 1 << 6, /* Do not follow the path's right-most component. With ret_fd, when the path's + * right-most component refers to symlink, return O_PATH fd of the symlink. */ + CHASE_WARN = 1 << 7, /* Emit an appropriate warning when an error is encountered. + * Note: this may do an NSS lookup, hence this flag cannot be used in PID 1. */ + CHASE_AT_RESOLVE_IN_ROOT = 1 << 8, /* Same as openat2()'s RESOLVE_IN_ROOT flag, symlinks are resolved + * relative to the given directory fd instead of root. */ + CHASE_PROHIBIT_SYMLINKS = 1 << 9, /* Refuse all symlinks */ + CHASE_PARENT = 1 << 10, /* Chase the parent directory of the given path. Note that the + * full path is still stored in ret_path and only the returned + * file descriptor will point to the parent directory. Note that + * the result path is the root or '.', then the file descriptor + * also points to the result path even if this flag is set. + * When this specified, chase() will succeed with 1 even if the + * file points to the last path component does not exist. */ + CHASE_MKDIR_0755 = 1 << 11, /* Create any missing parent directories in the given path. This + * needs to be set with CHASE_NONEXISTENT and/or CHASE_PARENT. + * Note, chase_and_open() or friends always add CHASE_PARENT flag + * when internally call chase(), hence CHASE_MKDIR_0755 can be + * safely set without CHASE_NONEXISTENT and CHASE_PARENT. */ + CHASE_EXTRACT_FILENAME = 1 << 12, /* Only return the last component of the resolved path */ +} ChaseFlags; + +bool unsafe_transition(const struct stat *a, const struct stat *b); + +/* How many iterations to execute before returning -ELOOP */ +#define CHASE_MAX 32 + +int chase(const char *path_with_prefix, const char *root, ChaseFlags chase_flags, char **ret_path, int *ret_fd); + +int chaseat_prefix_root(const char *path, const char *root, char **ret); +int chase_extract_filename(const char *path, const char *root, char **ret); + +int chase_and_open(const char *path, const char *root, ChaseFlags chase_flags, int open_flags, char **ret_path); +int chase_and_opendir(const char *path, const char *root, ChaseFlags chase_flags, char **ret_path, DIR **ret_dir); +int chase_and_stat(const char *path, const char *root, ChaseFlags chase_flags, char **ret_path, struct stat *ret_stat); +int chase_and_access(const char *path, const char *root, ChaseFlags chase_flags, int access_mode, char **ret_path); +int chase_and_fopen_unlocked(const char *path, const char *root, ChaseFlags chase_flags, const char *open_flags, char **ret_path, FILE **ret_file); +int chase_and_unlink(const char *path, const char *root, ChaseFlags chase_flags, int unlink_flags, char **ret_path); +int chase_and_open_parent(const char *path, const char *root, ChaseFlags chase_flags, char **ret_filename); + +int chaseat(int dir_fd, const char *path, ChaseFlags flags, char **ret_path, int *ret_fd); + +int chase_and_openat(int dir_fd, const char *path, ChaseFlags chase_flags, int open_flags, char **ret_path); +int chase_and_opendirat(int dir_fd, const char *path, ChaseFlags chase_flags, char **ret_path, DIR **ret_dir); +int chase_and_statat(int dir_fd, const char *path, ChaseFlags chase_flags, char **ret_path, struct stat *ret_stat); +int chase_and_accessat(int dir_fd, const char *path, ChaseFlags chase_flags, int access_mode, char **ret_path); +int chase_and_fopenat_unlocked(int dir_fd, const char *path, ChaseFlags chase_flags, const char *open_flags, char **ret_path, FILE **ret_file); +int chase_and_unlinkat(int dir_fd, const char *path, ChaseFlags chase_flags, int unlink_flags, char **ret_path); +int chase_and_open_parent_at(int dir_fd, const char *path, ChaseFlags chase_flags, char **ret_filename); |