diff options
author | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-06-01 15:52:09 -0400 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-06-01 15:52:09 -0400 |
commit | bb110bc7433adeb79b4814ef2a1c04e2160be396 (patch) | |
tree | c45048907133b8bbd7e2d86b350436a9ad0ffe8b /src/libbasic/fs-util.c | |
parent | 192d82912f055a2b4a2b5c02f0ef69b002322bba (diff) |
./move.sh
Diffstat (limited to 'src/libbasic/fs-util.c')
-rw-r--r-- | src/libbasic/fs-util.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/src/libbasic/fs-util.c b/src/libbasic/fs-util.c new file mode 100644 index 0000000000..3ef1b90edd --- /dev/null +++ b/src/libbasic/fs-util.c @@ -0,0 +1,513 @@ +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <dirent.h> +#include <errno.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <time.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "dirent-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "log.h" +#include "macro.h" +#include "missing.h" +#include "mkdir.h" +#include "parse-util.h" +#include "path-util.h" +#include "string-util.h" +#include "strv.h" +#include "time-util.h" +#include "user-util.h" +#include "util.h" + +int unlink_noerrno(const char *path) { + PROTECT_ERRNO; + int r; + + r = unlink(path); + if (r < 0) + return -errno; + + return 0; +} + +int rmdir_parents(const char *path, const char *stop) { + size_t l; + int r = 0; + + assert(path); + assert(stop); + + l = strlen(path); + + /* Skip trailing slashes */ + while (l > 0 && path[l-1] == '/') + l--; + + while (l > 0) { + char *t; + + /* Skip last component */ + while (l > 0 && path[l-1] != '/') + l--; + + /* Skip trailing slashes */ + while (l > 0 && path[l-1] == '/') + l--; + + if (l <= 0) + break; + + t = strndup(path, l); + if (!t) + return -ENOMEM; + + if (path_startswith(stop, t)) { + free(t); + return 0; + } + + r = rmdir(t); + free(t); + + if (r < 0) + if (errno != ENOENT) + return -errno; + } + + return 0; +} + + +int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) { + struct stat buf; + int ret; + + ret = renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE); + if (ret >= 0) + return 0; + + /* renameat2() exists since Linux 3.15, btrfs added support for it later. + * If it is not implemented, fallback to another method. */ + if (!IN_SET(errno, EINVAL, ENOSYS)) + return -errno; + + /* The link()/unlink() fallback does not work on directories. But + * renameat() without RENAME_NOREPLACE gives the same semantics on + * directories, except when newpath is an *empty* directory. This is + * good enough. */ + ret = fstatat(olddirfd, oldpath, &buf, AT_SYMLINK_NOFOLLOW); + if (ret >= 0 && S_ISDIR(buf.st_mode)) { + ret = renameat(olddirfd, oldpath, newdirfd, newpath); + return ret >= 0 ? 0 : -errno; + } + + /* If it is not a directory, use the link()/unlink() fallback. */ + ret = linkat(olddirfd, oldpath, newdirfd, newpath, 0); + if (ret < 0) + return -errno; + + ret = unlinkat(olddirfd, oldpath, 0); + if (ret < 0) { + /* backup errno before the following unlinkat() alters it */ + ret = errno; + (void) unlinkat(newdirfd, newpath, 0); + errno = ret; + return -errno; + } + + return 0; +} + +int readlinkat_malloc(int fd, const char *p, char **ret) { + size_t l = 100; + int r; + + assert(p); + assert(ret); + + for (;;) { + char *c; + ssize_t n; + + c = new(char, l); + if (!c) + return -ENOMEM; + + n = readlinkat(fd, p, c, l-1); + if (n < 0) { + r = -errno; + free(c); + return r; + } + + if ((size_t) n < l-1) { + c[n] = 0; + *ret = c; + return 0; + } + + free(c); + l *= 2; + } +} + +int readlink_malloc(const char *p, char **ret) { + return readlinkat_malloc(AT_FDCWD, p, ret); +} + +int readlink_value(const char *p, char **ret) { + _cleanup_free_ char *link = NULL; + char *value; + int r; + + r = readlink_malloc(p, &link); + if (r < 0) + return r; + + value = basename(link); + if (!value) + return -ENOENT; + + value = strdup(value); + if (!value) + return -ENOMEM; + + *ret = value; + + return 0; +} + +int readlink_and_make_absolute(const char *p, char **r) { + _cleanup_free_ char *target = NULL; + char *k; + int j; + + assert(p); + assert(r); + + j = readlink_malloc(p, &target); + if (j < 0) + return j; + + k = file_in_same_dir(p, target); + if (!k) + return -ENOMEM; + + *r = k; + return 0; +} + +int readlink_and_canonicalize(const char *p, char **r) { + char *t, *s; + int j; + + assert(p); + assert(r); + + j = readlink_and_make_absolute(p, &t); + if (j < 0) + return j; + + s = canonicalize_file_name(t); + if (s) { + free(t); + *r = s; + } else + *r = t; + + path_kill_slashes(*r); + + return 0; +} + +int readlink_and_make_absolute_root(const char *root, const char *path, char **ret) { + _cleanup_free_ char *target = NULL, *t = NULL; + const char *full; + int r; + + full = prefix_roota(root, path); + r = readlink_malloc(full, &target); + if (r < 0) + return r; + + t = file_in_same_dir(path, target); + if (!t) + return -ENOMEM; + + *ret = t; + t = NULL; + + return 0; +} + +int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) { + assert(path); + + /* Under the assumption that we are running privileged we + * first change the access mode and only then hand out + * ownership to avoid a window where access is too open. */ + + if (mode != MODE_INVALID) + if (chmod(path, mode) < 0) + return -errno; + + if (uid != UID_INVALID || gid != GID_INVALID) + if (chown(path, uid, gid) < 0) + return -errno; + + return 0; +} + +int fchmod_and_fchown(int fd, mode_t mode, uid_t uid, gid_t gid) { + assert(fd >= 0); + + /* Under the assumption that we are running privileged we + * first change the access mode and only then hand out + * ownership to avoid a window where access is too open. */ + + if (mode != MODE_INVALID) + if (fchmod(fd, mode) < 0) + return -errno; + + if (uid != UID_INVALID || gid != GID_INVALID) + if (fchown(fd, uid, gid) < 0) + return -errno; + + return 0; +} + +int fchmod_umask(int fd, mode_t m) { + mode_t u; + int r; + + u = umask(0777); + r = fchmod(fd, m & (~u)) < 0 ? -errno : 0; + umask(u); + + return r; +} + +int fd_warn_permissions(const char *path, int fd) { + struct stat st; + + if (fstat(fd, &st) < 0) + return -errno; + + if (st.st_mode & 0111) + log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path); + + if (st.st_mode & 0002) + log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path); + + if (getpid() == 1 && (st.st_mode & 0044) != 0044) + log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path); + + return 0; +} + +int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) { + _cleanup_close_ int fd; + int r; + + assert(path); + + if (parents) + mkdir_parents(path, 0755); + + fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, + (mode == 0 || mode == MODE_INVALID) ? 0644 : mode); + if (fd < 0) + return -errno; + + if (mode != MODE_INVALID) { + r = fchmod(fd, mode); + if (r < 0) + return -errno; + } + + if (uid != UID_INVALID || gid != GID_INVALID) { + r = fchown(fd, uid, gid); + if (r < 0) + return -errno; + } + + if (stamp != USEC_INFINITY) { + struct timespec ts[2]; + + timespec_store(&ts[0], stamp); + ts[1] = ts[0]; + r = futimens(fd, ts); + } else + r = futimens(fd, NULL); + if (r < 0) + return -errno; + + return 0; +} + +int touch(const char *path) { + return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID); +} + +int symlink_idempotent(const char *from, const char *to) { + _cleanup_free_ char *p = NULL; + int r; + + assert(from); + assert(to); + + if (symlink(from, to) < 0) { + if (errno != EEXIST) + return -errno; + + r = readlink_malloc(to, &p); + if (r < 0) + return r; + + if (!streq(p, from)) + return -EINVAL; + } + + return 0; +} + +int symlink_atomic(const char *from, const char *to) { + _cleanup_free_ char *t = NULL; + int r; + + assert(from); + assert(to); + + r = tempfn_random(to, NULL, &t); + if (r < 0) + return r; + + if (symlink(from, t) < 0) + return -errno; + + if (rename(t, to) < 0) { + unlink_noerrno(t); + return -errno; + } + + return 0; +} + +int mknod_atomic(const char *path, mode_t mode, dev_t dev) { + _cleanup_free_ char *t = NULL; + int r; + + assert(path); + + r = tempfn_random(path, NULL, &t); + if (r < 0) + return r; + + if (mknod(t, mode, dev) < 0) + return -errno; + + if (rename(t, path) < 0) { + unlink_noerrno(t); + return -errno; + } + + return 0; +} + +int mkfifo_atomic(const char *path, mode_t mode) { + _cleanup_free_ char *t = NULL; + int r; + + assert(path); + + r = tempfn_random(path, NULL, &t); + if (r < 0) + return r; + + if (mkfifo(t, mode) < 0) + return -errno; + + if (rename(t, path) < 0) { + unlink_noerrno(t); + return -errno; + } + + return 0; +} + +int get_files_in_directory(const char *path, char ***list) { + _cleanup_closedir_ DIR *d = NULL; + size_t bufsize = 0, n = 0; + _cleanup_strv_free_ char **l = NULL; + + assert(path); + + /* Returns all files in a directory in *list, and the number + * of files as return value. If list is NULL returns only the + * number. */ + + d = opendir(path); + if (!d) + return -errno; + + for (;;) { + struct dirent *de; + + errno = 0; + de = readdir(d); + if (!de && errno > 0) + return -errno; + if (!de) + break; + + dirent_ensure_type(d, de); + + if (!dirent_is_file(de)) + continue; + + if (list) { + /* one extra slot is needed for the terminating NULL */ + if (!GREEDY_REALLOC(l, bufsize, n + 2)) + return -ENOMEM; + + l[n] = strdup(de->d_name); + if (!l[n]) + return -ENOMEM; + + l[++n] = NULL; + } else + n++; + } + + if (list) { + *list = l; + l = NULL; /* avoid freeing */ + } + + return n; +} |