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-rw-r--r--lib/chowndir.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/lib/chowndir.c b/lib/chowndir.c
new file mode 100644
index 0000000..d31618a
--- /dev/null
+++ b/lib/chowndir.c
@@ -0,0 +1,146 @@
+/*
+ * SPDX-FileCopyrightText: 1992 - 1993, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2010 - , Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include "prototypes.h"
+#include "defines.h"
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+static int chown_tree_at (int at_fd,
+ const char *path,
+ uid_t old_uid,
+ uid_t new_uid,
+ gid_t old_gid,
+ gid_t new_gid)
+{
+ DIR *dir;
+ const struct dirent *ent;
+ struct stat dir_sb;
+ int dir_fd, rc = 0;
+
+ dir_fd = openat (at_fd, path, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
+ if (dir_fd < 0) {
+ return -1;
+ }
+
+ dir = fdopendir (dir_fd);
+ if (!dir) {
+ (void) close (dir_fd);
+ return -1;
+ }
+
+ /*
+ * Open the directory and read each entry. Every entry is tested
+ * to see if it is a directory, and if so this routine is called
+ * recursively. If not, it is checked to see if an ownership
+ * shall be changed.
+ */
+ while ((ent = readdir (dir))) {
+ uid_t tmpuid = (uid_t) -1;
+ gid_t tmpgid = (gid_t) -1;
+ struct stat ent_sb;
+
+ /*
+ * Skip the "." and ".." entries
+ */
+ if ( (strcmp (ent->d_name, ".") == 0)
+ || (strcmp (ent->d_name, "..") == 0)) {
+ continue;
+ }
+
+ rc = fstatat (dirfd(dir), ent->d_name, &ent_sb, AT_SYMLINK_NOFOLLOW);
+ if (rc < 0) {
+ break;
+ }
+
+ if (S_ISDIR (ent_sb.st_mode)) {
+ /*
+ * Do the entire subdirectory.
+ */
+ rc = chown_tree_at (dirfd(dir), ent->d_name, old_uid, new_uid, old_gid, new_gid);
+ if (0 != rc) {
+ break;
+ }
+ }
+
+ /*
+ * By default, the IDs are not changed (-1).
+ *
+ * If the file is not owned by the user, the owner is not
+ * changed.
+ *
+ * If the file is not group-owned by the group, the
+ * group-owner is not changed.
+ */
+ if (((uid_t) -1 == old_uid) || (ent_sb.st_uid == old_uid)) {
+ tmpuid = new_uid;
+ }
+ if (((gid_t) -1 == old_gid) || (ent_sb.st_gid == old_gid)) {
+ tmpgid = new_gid;
+ }
+ if (((uid_t) -1 != tmpuid) || ((gid_t) -1 != tmpgid)) {
+ rc = fchownat (dirfd(dir), ent->d_name, tmpuid, tmpgid, AT_SYMLINK_NOFOLLOW);
+ if (0 != rc) {
+ break;
+ }
+ }
+ }
+
+ /*
+ * Now do the root of the tree
+ */
+ if ((0 == rc) && (fstat (dirfd(dir), &dir_sb) == 0)) {
+ uid_t tmpuid = (uid_t) -1;
+ gid_t tmpgid = (gid_t) -1;
+ if (((uid_t) -1 == old_uid) || (dir_sb.st_uid == old_uid)) {
+ tmpuid = new_uid;
+ }
+ if (((gid_t) -1 == old_gid) || (dir_sb.st_gid == old_gid)) {
+ tmpgid = new_gid;
+ }
+ if (((uid_t) -1 != tmpuid) || ((gid_t) -1 != tmpgid)) {
+ rc = fchown (dirfd(dir), tmpuid, tmpgid);
+ }
+ } else {
+ rc = -1;
+ }
+
+ (void) closedir (dir);
+
+ return rc;
+}
+
+/*
+ * chown_tree - change ownership of files in a directory tree
+ *
+ * chown_dir() walks a directory tree and changes the ownership
+ * of all files owned by the provided user ID.
+ *
+ * Only files owned (resp. group-owned) by old_uid (resp. by old_gid)
+ * will have their ownership (resp. group-ownership) modified, unless
+ * old_uid (resp. old_gid) is set to -1.
+ *
+ * new_uid and new_gid can be set to -1 to indicate that no owner or
+ * group-owner shall be changed.
+ */
+int chown_tree (const char *root,
+ uid_t old_uid,
+ uid_t new_uid,
+ gid_t old_gid,
+ gid_t new_gid)
+{
+ return chown_tree_at (AT_FDCWD, root, old_uid, new_uid, old_gid, new_gid);
+}