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authorLennart Poettering <lennart@poettering.net>2015-04-04 11:52:57 +0200
committerLennart Poettering <lennart@poettering.net>2015-04-06 10:57:53 +0200
commitc6878637502b1717a110a9a7e8bba32a8583fcdf (patch)
tree44bd9f305f8f3b97a0c736c3ac549e568b6495cd /src/shared
parent2f653bded321fc2271edcda43d54fcc3e6c20dc9 (diff)
util: rework rm_rf() logic
- Move to its own file rm-rf.c - Change parameters into a single flags parameter - Remove "honour sticky" logic, it's unused these days
Diffstat (limited to 'src/shared')
-rw-r--r--src/shared/machine-image.c3
-rw-r--r--src/shared/rm-rf.c173
-rw-r--r--src/shared/rm-rf.h33
-rw-r--r--src/shared/switch-root.c5
-rw-r--r--src/shared/util.c199
-rw-r--r--src/shared/util.h9
6 files changed, 216 insertions, 206 deletions
diff --git a/src/shared/machine-image.c b/src/shared/machine-image.c
index edf986d4db..c5808af81e 100644
--- a/src/shared/machine-image.c
+++ b/src/shared/machine-image.c
@@ -28,6 +28,7 @@
#include "path-util.h"
#include "copy.h"
#include "mkdir.h"
+#include "rm-rf.h"
#include "machine-image.h"
static const char image_search_path[] =
@@ -366,7 +367,7 @@ int image_remove(Image *i) {
/* fall through */
case IMAGE_RAW:
- return rm_rf_dangerous(i->path, false, true, false);
+ return rm_rf(i->path, REMOVE_ROOT|REMOVE_PHYSICAL);
default:
return -EOPNOTSUPP;
diff --git a/src/shared/rm-rf.c b/src/shared/rm-rf.c
new file mode 100644
index 0000000000..99d12b11c6
--- /dev/null
+++ b/src/shared/rm-rf.c
@@ -0,0 +1,173 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2015 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 "util.h"
+#include "path-util.h"
+#include "rm-rf.h"
+
+int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev) {
+ _cleanup_closedir_ DIR *d = NULL;
+ int ret = 0, r;
+
+ assert(fd >= 0);
+
+ /* This returns the first error we run into, but nevertheless
+ * tries to go on. This closes the passed fd. */
+
+ if (!(flags & REMOVE_PHYSICAL)) {
+
+ r = fd_is_temporary_fs(fd);
+ if (r < 0) {
+ safe_close(fd);
+ return r;
+ }
+
+ if (!r) {
+ /* We refuse to clean physical file systems
+ * with this call, unless explicitly
+ * requested. This is extra paranoia just to
+ * be sure we never ever remove non-state
+ * data */
+
+ log_error("Attempted to remove disk file system, and we can't allow that.");
+ safe_close(fd);
+ return -EPERM;
+ }
+ }
+
+ d = fdopendir(fd);
+ if (!d) {
+ safe_close(fd);
+ return errno == ENOENT ? 0 : -errno;
+ }
+
+ for (;;) {
+ struct dirent *de;
+ bool is_dir;
+ struct stat st;
+
+ errno = 0;
+ de = readdir(d);
+ if (!de) {
+ if (errno != 0 && ret == 0)
+ ret = -errno;
+ return ret;
+ }
+
+ if (streq(de->d_name, ".") || streq(de->d_name, ".."))
+ continue;
+
+ if (de->d_type == DT_UNKNOWN || (de->d_type == DT_DIR && root_dev)) {
+ if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
+ if (ret == 0 && errno != ENOENT)
+ ret = -errno;
+ continue;
+ }
+
+ is_dir = S_ISDIR(st.st_mode);
+ } else
+ is_dir = de->d_type == DT_DIR;
+
+ if (is_dir) {
+ int subdir_fd;
+
+ /* if root_dev is set, remove subdirectories only, if device is same as dir */
+ if (root_dev && st.st_dev != root_dev->st_dev)
+ continue;
+
+ subdir_fd = openat(fd, de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+ if (subdir_fd < 0) {
+ if (ret == 0 && errno != ENOENT)
+ ret = -errno;
+ continue;
+ }
+
+ /* We pass REMOVE_PHYSICAL here, to avoid
+ * doing the fstatfs() to check the file
+ * system type again for each directory */
+ r = rm_rf_children(subdir_fd, flags | REMOVE_PHYSICAL, root_dev);
+ if (r < 0 && ret == 0)
+ ret = r;
+
+ if (unlinkat(fd, de->d_name, AT_REMOVEDIR) < 0) {
+ if (ret == 0 && errno != ENOENT)
+ ret = -errno;
+ }
+
+ } else if (!(flags & REMOVE_ONLY_DIRECTORIES)) {
+
+ if (unlinkat(fd, de->d_name, 0) < 0) {
+ if (ret == 0 && errno != ENOENT)
+ ret = -errno;
+ }
+ }
+ }
+}
+
+int rm_rf(const char *path, RemoveFlags flags) {
+ int fd, r;
+ struct statfs s;
+
+ assert(path);
+
+ /* We refuse to clean the root file system with this
+ * call. This is extra paranoia to never cause a really
+ * seriously broken system. */
+ if (path_equal(path, "/")) {
+ log_error("Attempted to remove entire root file system, and we can't allow that.");
+ return -EPERM;
+ }
+
+ fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+ if (fd < 0) {
+
+ if (errno != ENOTDIR && errno != ELOOP)
+ return -errno;
+
+ if (!(flags & REMOVE_PHYSICAL)) {
+ if (statfs(path, &s) < 0)
+ return -errno;
+
+ if (!is_temporary_fs(&s)) {
+ log_error("Attempted to remove disk file system, and we can't allow that.");
+ return -EPERM;
+ }
+ }
+
+ if ((flags & REMOVE_ROOT) && !(flags & REMOVE_ONLY_DIRECTORIES))
+ if (unlink(path) < 0 && errno != ENOENT)
+ return -errno;
+
+ return 0;
+ }
+
+ r = rm_rf_children(fd, flags, NULL);
+
+ if (flags & REMOVE_ROOT) {
+
+ if (rmdir(path) < 0 && errno != ENOENT) {
+ if (r == 0)
+ r = -errno;
+ }
+ }
+
+ return r;
+}
diff --git a/src/shared/rm-rf.h b/src/shared/rm-rf.h
new file mode 100644
index 0000000000..769bbc853d
--- /dev/null
+++ b/src/shared/rm-rf.h
@@ -0,0 +1,33 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+ This file is part of systemd.
+
+ Copyright 2015 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 <sys/stat.h>
+
+typedef enum RemoveFlags {
+ REMOVE_ONLY_DIRECTORIES = 1,
+ REMOVE_ROOT = 2,
+ REMOVE_PHYSICAL = 4, /* if not set, only removes files on tmpfs, never physical file systems */
+} RemoveFlags;
+
+int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev);
+int rm_rf(const char *path, RemoveFlags flags);
diff --git a/src/shared/switch-root.c b/src/shared/switch-root.c
index 813641ad44..ae3839de16 100644
--- a/src/shared/switch-root.c
+++ b/src/shared/switch-root.c
@@ -29,10 +29,11 @@
#include "util.h"
#include "path-util.h"
-#include "switch-root.h"
#include "mkdir.h"
+#include "rm-rf.h"
#include "base-filesystem.h"
#include "missing.h"
+#include "switch-root.h"
int switch_root(const char *new_root, const char *oldroot, bool detach_oldroot, unsigned long mountflags) {
@@ -142,7 +143,7 @@ int switch_root(const char *new_root, const char *oldroot, bool detach_oldroot,
if (fstat(old_root_fd, &rb) < 0)
log_warning_errno(errno, "Failed to stat old root directory, leaving: %m");
else {
- rm_rf_children(old_root_fd, false, false, &rb);
+ (void) rm_rf_children(old_root_fd, 0, &rb);
old_root_fd = -1;
}
}
diff --git a/src/shared/util.c b/src/shared/util.c
index 605fffcb7a..8b011ccfa1 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -2988,101 +2988,14 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
return 0;
}
-int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
- _cleanup_closedir_ DIR *d = NULL;
- int ret = 0;
-
- assert(fd >= 0);
-
- /* This returns the first error we run into, but nevertheless
- * tries to go on. This closes the passed fd. */
-
- d = fdopendir(fd);
- if (!d) {
- safe_close(fd);
-
- return errno == ENOENT ? 0 : -errno;
- }
-
- for (;;) {
- struct dirent *de;
- bool is_dir, keep_around;
- struct stat st;
- int r;
-
- errno = 0;
- de = readdir(d);
- if (!de) {
- if (errno != 0 && ret == 0)
- ret = -errno;
- return ret;
- }
-
- if (streq(de->d_name, ".") || streq(de->d_name, ".."))
- continue;
-
- if (de->d_type == DT_UNKNOWN ||
- honour_sticky ||
- (de->d_type == DT_DIR && root_dev)) {
- if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
- if (ret == 0 && errno != ENOENT)
- ret = -errno;
- continue;
- }
-
- is_dir = S_ISDIR(st.st_mode);
- keep_around =
- honour_sticky &&
- (st.st_uid == 0 || st.st_uid == getuid()) &&
- (st.st_mode & S_ISVTX);
- } else {
- is_dir = de->d_type == DT_DIR;
- keep_around = false;
- }
-
- if (is_dir) {
- int subdir_fd;
-
- /* if root_dev is set, remove subdirectories only, if device is same as dir */
- if (root_dev && st.st_dev != root_dev->st_dev)
- continue;
-
- subdir_fd = openat(fd, de->d_name,
- O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
- if (subdir_fd < 0) {
- if (ret == 0 && errno != ENOENT)
- ret = -errno;
- continue;
- }
-
- r = rm_rf_children_dangerous(subdir_fd, only_dirs, honour_sticky, root_dev);
- if (r < 0 && ret == 0)
- ret = r;
-
- if (!keep_around)
- if (unlinkat(fd, de->d_name, AT_REMOVEDIR) < 0) {
- if (ret == 0 && errno != ENOENT)
- ret = -errno;
- }
-
- } else if (!only_dirs && !keep_around) {
-
- if (unlinkat(fd, de->d_name, 0) < 0) {
- if (ret == 0 && errno != ENOENT)
- ret = -errno;
- }
- }
- }
-}
-
-_pure_ static int is_temporary_fs(struct statfs *s) {
+bool is_temporary_fs(const struct statfs *s) {
assert(s);
return F_TYPE_EQUAL(s->f_type, TMPFS_MAGIC) ||
F_TYPE_EQUAL(s->f_type, RAMFS_MAGIC);
}
-int is_fd_on_temporary_fs(int fd) {
+int fd_is_temporary_fs(int fd) {
struct statfs s;
if (fstatfs(fd, &s) < 0)
@@ -3091,114 +3004,6 @@ int is_fd_on_temporary_fs(int fd) {
return is_temporary_fs(&s);
}
-int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
- struct statfs s;
-
- assert(fd >= 0);
-
- if (fstatfs(fd, &s) < 0) {
- safe_close(fd);
- return -errno;
- }
-
- /* We refuse to clean disk file systems with this call. This
- * is extra paranoia just to be sure we never ever remove
- * non-state data */
- if (!is_temporary_fs(&s)) {
- log_error("Attempted to remove disk file system, and we can't allow that.");
- safe_close(fd);
- return -EPERM;
- }
-
- return rm_rf_children_dangerous(fd, only_dirs, honour_sticky, root_dev);
-}
-
-static int file_is_priv_sticky(const char *p) {
- struct stat st;
-
- assert(p);
-
- if (lstat(p, &st) < 0)
- return -errno;
-
- return
- (st.st_uid == 0 || st.st_uid == getuid()) &&
- (st.st_mode & S_ISVTX);
-}
-
-static int rm_rf_internal(const char *path, bool only_dirs, bool delete_root, bool honour_sticky, bool dangerous) {
- int fd, r;
- struct statfs s;
-
- assert(path);
-
- /* We refuse to clean the root file system with this
- * call. This is extra paranoia to never cause a really
- * seriously broken system. */
- if (path_equal(path, "/")) {
- log_error("Attempted to remove entire root file system, and we can't allow that.");
- return -EPERM;
- }
-
- fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
- if (fd < 0) {
-
- if (errno != ENOTDIR && errno != ELOOP)
- return -errno;
-
- if (!dangerous) {
- if (statfs(path, &s) < 0)
- return -errno;
-
- if (!is_temporary_fs(&s)) {
- log_error("Attempted to remove disk file system, and we can't allow that.");
- return -EPERM;
- }
- }
-
- if (delete_root && !only_dirs)
- if (unlink(path) < 0 && errno != ENOENT)
- return -errno;
-
- return 0;
- }
-
- if (!dangerous) {
- if (fstatfs(fd, &s) < 0) {
- safe_close(fd);
- return -errno;
- }
-
- if (!is_temporary_fs(&s)) {
- log_error("Attempted to remove disk file system, and we can't allow that.");
- safe_close(fd);
- return -EPERM;
- }
- }
-
- r = rm_rf_children_dangerous(fd, only_dirs, honour_sticky, NULL);
- if (delete_root) {
-
- if (honour_sticky && file_is_priv_sticky(path) > 0)
- return r;
-
- if (rmdir(path) < 0 && errno != ENOENT) {
- if (r == 0)
- r = -errno;
- }
- }
-
- return r;
-}
-
-int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
- return rm_rf_internal(path, only_dirs, delete_root, honour_sticky, false);
-}
-
-int rm_rf_dangerous(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
- return rm_rf_internal(path, only_dirs, delete_root, honour_sticky, true);
-}
-
int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
assert(path);
diff --git a/src/shared/util.h b/src/shared/util.h
index 124c7c06d4..882355665c 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -41,6 +41,7 @@
#include <locale.h>
#include <mntent.h>
#include <sys/inotify.h>
+#include <sys/statfs.h>
#if SIZEOF_PID_T == 4
# define PID_PRI PRIi32
@@ -461,12 +462,8 @@ int get_ctty(pid_t, dev_t *_devnr, char **r);
int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
int fchmod_and_fchown(int fd, mode_t mode, uid_t uid, gid_t gid);
-int is_fd_on_temporary_fs(int fd);
-
-int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev);
-int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev);
-int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky);
-int rm_rf_dangerous(const char *path, bool only_dirs, bool delete_root, bool honour_sticky);
+bool is_temporary_fs(const struct statfs *s) _pure_;
+int fd_is_temporary_fs(int fd);
int pipe_eof(int fd);