diff options
Diffstat (limited to 'src/basic/mkdir.c')
-rw-r--r-- | src/basic/mkdir.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/src/basic/mkdir.c b/src/basic/mkdir.c new file mode 100644 index 0000000..c8ff342 --- /dev/null +++ b/src/basic/mkdir.c @@ -0,0 +1,249 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <stdbool.h> +#include <string.h> + +#include "alloc-util.h" +#include "chase-symlinks.h" +#include "fd-util.h" +#include "format-util.h" +#include "fs-util.h" +#include "macro.h" +#include "mkdir.h" +#include "path-util.h" +#include "stat-util.h" +#include "stdio-util.h" +#include "user-util.h" + +int mkdir_safe_internal( + const char *path, + mode_t mode, + uid_t uid, + gid_t gid, + MkdirFlags flags, + mkdirat_func_t _mkdirat) { + + struct stat st; + int r; + + assert(path); + assert(mode != MODE_INVALID); + assert(_mkdirat && _mkdirat != mkdirat); + + if (_mkdirat(AT_FDCWD, path, mode) >= 0) { + r = chmod_and_chown(path, mode, uid, gid); + if (r < 0) + return r; + } + + if (lstat(path, &st) < 0) + return -errno; + + if ((flags & MKDIR_FOLLOW_SYMLINK) && S_ISLNK(st.st_mode)) { + _cleanup_free_ char *p = NULL; + + r = chase_symlinks(path, NULL, CHASE_NONEXISTENT, &p, NULL); + if (r < 0) + return r; + if (r == 0) + return mkdir_safe_internal(p, mode, uid, gid, + flags & ~MKDIR_FOLLOW_SYMLINK, + _mkdirat); + + if (lstat(p, &st) < 0) + return -errno; + } + + if (flags & MKDIR_IGNORE_EXISTING) + return 0; + + if (!S_ISDIR(st.st_mode)) + return log_full_errno(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG, SYNTHETIC_ERRNO(ENOTDIR), + "Path \"%s\" already exists and is not a directory, refusing.", path); + + if ((st.st_mode & ~mode & 0777) != 0) + return log_full_errno(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG, SYNTHETIC_ERRNO(EEXIST), + "Directory \"%s\" already exists, but has mode %04o that is too permissive (%04o was requested), refusing.", + path, st.st_mode & 0777, mode); + + if ((uid != UID_INVALID && st.st_uid != uid) || + (gid != GID_INVALID && st.st_gid != gid)) { + char u[DECIMAL_STR_MAX(uid_t)] = "-", g[DECIMAL_STR_MAX(gid_t)] = "-"; + + if (uid != UID_INVALID) + xsprintf(u, UID_FMT, uid); + if (gid != UID_INVALID) + xsprintf(g, GID_FMT, gid); + return log_full_errno(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG, SYNTHETIC_ERRNO(EEXIST), + "Directory \"%s\" already exists, but is owned by "UID_FMT":"GID_FMT" (%s:%s was requested), refusing.", + path, st.st_uid, st.st_gid, u, g); + } + + return 0; +} + +int mkdirat_errno_wrapper(int dirfd, const char *pathname, mode_t mode) { + return RET_NERRNO(mkdirat(dirfd, pathname, mode)); +} + +int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) { + return mkdir_safe_internal(path, mode, uid, gid, flags, mkdirat_errno_wrapper); +} + +int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdirat_func_t _mkdirat) { + const char *p, *e = NULL; + int r; + + assert(path); + assert(_mkdirat != mkdirat); + + if (prefix) { + p = path_startswith_full(path, prefix, /* accept_dot_dot= */ false); + if (!p) + return -ENOTDIR; + } else + p = path; + + if (isempty(p)) + return 0; + + if (!path_is_safe(p)) + return -ENOTDIR; + + /* return immediately if directory exists */ + r = path_find_last_component(p, /* accept_dot_dot= */ false, &e, NULL); + if (r <= 0) /* r == 0 means path is equivalent to prefix. */ + return r; + if (e == p) + return 0; + + assert(e > p); + assert(*e == '/'); + + /* drop the last component */ + path = strndupa_safe(path, e - path); + r = is_dir(path, true); + if (r > 0) + return 0; + if (r == 0) + return -ENOTDIR; + + /* create every parent directory in the path, except the last component */ + for (p = path;;) { + char *s; + int n; + + n = path_find_first_component(&p, /* accept_dot_dot= */ false, (const char **) &s); + if (n <= 0) + return n; + + assert(p); + assert(s >= path); + assert(IN_SET(s[n], '/', '\0')); + + s[n] = '\0'; + + if (!prefix || !path_startswith_full(prefix, path, /* accept_dot_dot= */ false)) { + r = mkdir_safe_internal(path, mode, uid, gid, flags | MKDIR_IGNORE_EXISTING, _mkdirat); + if (r < 0 && r != -EEXIST) + return r; + } + + s[n] = *p == '\0' ? '\0' : '/'; + } +} + +int mkdir_parents(const char *path, mode_t mode) { + return mkdir_parents_internal(NULL, path, mode, UID_INVALID, UID_INVALID, 0, mkdirat_errno_wrapper); +} + +int mkdir_parents_safe(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) { + return mkdir_parents_internal(prefix, path, mode, uid, gid, flags, mkdirat_errno_wrapper); +} + +int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdirat_func_t _mkdirat) { + int r; + + /* Like mkdir -p */ + + assert(_mkdirat != mkdirat); + + r = mkdir_parents_internal(prefix, path, mode, uid, gid, flags | MKDIR_FOLLOW_SYMLINK, _mkdirat); + if (r < 0) + return r; + + if (!uid_is_valid(uid) && !gid_is_valid(gid) && flags == 0) { + r = _mkdirat(AT_FDCWD, path, mode); + if (r < 0 && (r != -EEXIST || is_dir(path, true) <= 0)) + return r; + } else { + r = mkdir_safe_internal(path, mode, uid, gid, flags, _mkdirat); + if (r < 0 && r != -EEXIST) + return r; + } + + return 0; +} + +int mkdir_p(const char *path, mode_t mode) { + return mkdir_p_internal(NULL, path, mode, UID_INVALID, UID_INVALID, 0, mkdirat_errno_wrapper); +} + +int mkdir_p_safe(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) { + return mkdir_p_internal(prefix, path, mode, uid, gid, flags, mkdirat_errno_wrapper); +} + +int mkdir_p_root(const char *root, const char *p, uid_t uid, gid_t gid, mode_t m) { + _cleanup_free_ char *pp = NULL, *bn = NULL; + _cleanup_close_ int dfd = -1; + int r; + + r = path_extract_directory(p, &pp); + if (r == -EDESTADDRREQ) { + /* only fname is passed, no prefix to operate on */ + dfd = open(".", O_RDONLY|O_CLOEXEC|O_DIRECTORY); + if (dfd < 0) + return -errno; + } else if (r == -EADDRNOTAVAIL) + /* only root dir or "." was passed, i.e. there is no parent to extract, in that case there's nothing to do. */ + return 0; + else if (r < 0) + return r; + else { + /* Extracting the parent dir worked, hence we aren't top-level? Recurse up first. */ + r = mkdir_p_root(root, pp, uid, gid, m); + if (r < 0) + return r; + + dfd = chase_symlinks_and_open(pp, root, CHASE_PREFIX_ROOT, O_RDONLY|O_CLOEXEC|O_DIRECTORY, NULL); + if (dfd < 0) + return dfd; + } + + r = path_extract_filename(p, &bn); + if (r == -EADDRNOTAVAIL) /* Already top-level */ + return 0; + if (r < 0) + return r; + + if (mkdirat(dfd, bn, m) < 0) { + if (errno == EEXIST) + return 0; + + return -errno; + } + + if (uid_is_valid(uid) || gid_is_valid(gid)) { + _cleanup_close_ int nfd = -1; + + nfd = openat(dfd, bn, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (nfd < 0) + return -errno; + + if (fchown(nfd, uid, gid) < 0) + return -errno; + } + + return 1; +} |