cde221b858
The setuid, setgid, and sticky bits are not copied during copy_tree. Also start with very restrictive permissions before setting ownerships. This prevents situations in which users in a group with less permissions than others could win a race in opening the file before permissions are removed again. Proof of concept: $ echo $HOME /home/uwu $ install -o uwu -g fandom -m 604 /dev/null /home/uwu/owo $ ls -l /home/uwu/owo -rw----r-- 1 uwu fandom 0 Sep 4 00:00 /home/uwu/owo If /tmp is on another filesystem, then "usermod -md /tmp/uwu uwu" leads to this temporary situation: $ ls -l /tmp/uwu/owo -rw----r-- 1 root root 0 Sep 4 00:00 /tmp/uwu/owo This means that between openat and chownat_if_needed a user of group fandom could open /tmp/uwu/owo and read the content when it is finally written into the file.
973 lines
27 KiB
C
973 lines
27 KiB
C
/*
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* SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh
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* SPDX-FileCopyrightText: 1996 - 2001, Marek Michałkiewicz
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* SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko
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* SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <config.h>
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#ident "$Id$"
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#include <assert.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <sys/time.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include "prototypes.h"
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#include "defines.h"
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#ifdef WITH_SELINUX
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#include <selinux/selinux.h>
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#endif /* WITH_SELINUX */
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#if defined(WITH_ACL) || defined(WITH_ATTR)
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#include <stdarg.h>
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#include <attr/error_context.h>
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#endif /* WITH_ACL || WITH_ATTR */
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#ifdef WITH_ACL
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#include <acl/libacl.h>
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#endif /* WITH_ACL */
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#ifdef WITH_ATTR
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#include <attr/libattr.h>
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#endif /* WITH_ATTR */
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#include "shadowlog.h"
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static /*@null@*/const char *src_orig;
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static /*@null@*/const char *dst_orig;
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struct link_name {
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dev_t ln_dev;
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ino_t ln_ino;
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nlink_t ln_count;
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char *ln_name;
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/*@dependent@*/struct link_name *ln_next;
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};
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static /*@exposed@*/struct link_name *links;
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struct path_info {
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const char *full_path;
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int dirfd;
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const char *name;
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};
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static int copy_entry (const struct path_info *src, const struct path_info *dst,
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bool reset_selinux,
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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static int copy_dir (const struct path_info *src, const struct path_info *dst,
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bool reset_selinux,
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const struct stat *statp, const struct timespec mt[],
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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static /*@null@*/char *readlink_malloc (const char *filename);
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static int copy_symlink (const struct path_info *src, const struct path_info *dst,
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unused bool reset_selinux,
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const struct stat *statp, const struct timespec mt[],
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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static int copy_hardlink (const struct path_info *dst,
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unused bool reset_selinux,
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struct link_name *lp);
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static int copy_special (const struct path_info *src, const struct path_info *dst,
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bool reset_selinux,
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const struct stat *statp, const struct timespec mt[],
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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static int copy_file (const struct path_info *src, const struct path_info *dst,
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bool reset_selinux,
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const struct stat *statp, const struct timespec mt[],
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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static int chownat_if_needed (const struct path_info *dst, const struct stat *statp,
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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static int fchown_if_needed (int fdst, const struct stat *statp,
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid);
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#if defined(WITH_ACL) || defined(WITH_ATTR)
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/*
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* error_acl - format the error messages for the ACL and EQ libraries.
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*/
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format_attr(printf, 2, 3)
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static void error_acl (unused struct error_context *ctx, const char *fmt, ...)
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{
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va_list ap;
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FILE *shadow_logfd = log_get_logfd();
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/* ignore the case when destination does not support ACLs
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* or extended attributes */
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if (ENOTSUP == errno) {
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errno = 0;
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return;
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}
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va_start (ap, fmt);
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(void) fprintf (shadow_logfd, _("%s: "), log_get_progname());
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if (vfprintf (shadow_logfd, fmt, ap) != 0) {
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(void) fputs (_(": "), shadow_logfd);
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}
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(void) fprintf (shadow_logfd, "%s\n", strerror (errno));
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va_end (ap);
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}
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static struct error_context ctx = {
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error_acl, NULL, NULL
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};
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#endif /* WITH_ACL || WITH_ATTR */
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#ifdef WITH_ACL
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static int perm_copy_path(const struct path_info *src,
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const struct path_info *dst,
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struct error_context *errctx)
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{
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int src_fd, dst_fd, ret;
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src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
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if (src_fd < 0) {
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return -1;
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}
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dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
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if (dst_fd < 0) {
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(void) close (src_fd);
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return -1;
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}
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ret = perm_copy_fd(src->full_path, src_fd, dst->full_path, dst_fd, errctx);
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(void) close (src_fd);
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(void) close (dst_fd);
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return ret;
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}
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#endif /* WITH_ACL */
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#ifdef WITH_ATTR
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static int attr_copy_path(const struct path_info *src,
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const struct path_info *dst,
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int (*callback) (const char *, struct error_context *),
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struct error_context *errctx)
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{
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int src_fd, dst_fd, ret;
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src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
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if (src_fd < 0) {
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return -1;
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}
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dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
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if (dst_fd < 0) {
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(void) close (src_fd);
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return -1;
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}
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ret = attr_copy_fd(src->full_path, src_fd, dst->full_path, dst_fd, callback, errctx);
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(void) close (src_fd);
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(void) close (dst_fd);
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return ret;
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}
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#endif /* WITH_ATTR */
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/*
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* remove_link - delete a link from the linked list
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*/
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static void remove_link (/*@only@*/struct link_name *ln)
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{
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struct link_name *lp;
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if (links == ln) {
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links = ln->ln_next;
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free (ln->ln_name);
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free (ln);
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return;
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}
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for (lp = links; NULL !=lp; lp = lp->ln_next) {
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if (lp->ln_next == ln) {
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break;
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}
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}
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if (NULL == lp) {
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free (ln->ln_name);
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free (ln);
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return;
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}
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lp->ln_next = lp->ln_next->ln_next;
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free (ln->ln_name);
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free (ln);
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}
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/*
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* check_link - see if a file is really a link
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*/
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static /*@exposed@*/ /*@null@*/struct link_name *check_link (const char *name, const struct stat *sb)
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{
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struct link_name *lp;
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size_t src_len;
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size_t dst_len;
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size_t name_len;
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size_t len;
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/* copy_tree () must be the entry point */
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assert (NULL != src_orig);
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assert (NULL != dst_orig);
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for (lp = links; NULL != lp; lp = lp->ln_next) {
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if ((lp->ln_dev == sb->st_dev) && (lp->ln_ino == sb->st_ino)) {
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return lp;
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}
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}
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if (sb->st_nlink == 1) {
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return NULL;
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}
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lp = (struct link_name *) xmalloc (sizeof *lp);
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src_len = strlen (src_orig);
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dst_len = strlen (dst_orig);
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name_len = strlen (name);
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lp->ln_dev = sb->st_dev;
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lp->ln_ino = sb->st_ino;
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lp->ln_count = sb->st_nlink;
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len = name_len - src_len + dst_len + 1;
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lp->ln_name = (char *) xmalloc (len);
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(void) snprintf (lp->ln_name, len, "%s%s", dst_orig, name + src_len);
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lp->ln_next = links;
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links = lp;
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return NULL;
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}
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static int copy_tree_impl (const struct path_info *src, const struct path_info *dst,
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bool copy_root, bool reset_selinux,
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uid_t old_uid, uid_t new_uid,
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gid_t old_gid, gid_t new_gid)
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{
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int dst_fd, src_fd, err = 0;
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bool set_orig = false;
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const struct dirent *ent;
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DIR *dir;
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if (copy_root) {
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struct stat sb;
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if ( fstatat (dst->dirfd, dst->name, &sb, 0) == 0
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|| errno != ENOENT) {
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return -1;
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}
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if (fstatat (src->dirfd, src->name, &sb, AT_SYMLINK_NOFOLLOW) == -1) {
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return -1;
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}
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if (!S_ISDIR (sb.st_mode)) {
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fprintf (log_get_logfd(),
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"%s: %s is not a directory",
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log_get_progname(), src->full_path);
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return -1;
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}
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return copy_entry (src, dst, reset_selinux,
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old_uid, new_uid, old_gid, new_gid);
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}
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/*
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* Make certain both directories exist. This routine is called
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* after the home directory is created, or recursively after the
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* target is created. It assumes the target directory exists.
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*/
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src_fd = openat (src->dirfd, src->name, O_DIRECTORY | O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
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if (src_fd < 0) {
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return -1;
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}
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dst_fd = openat (dst->dirfd, dst->name, O_DIRECTORY | O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
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if (dst_fd < 0) {
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(void) close (src_fd);
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return -1;
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}
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/*
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* Open the source directory and read each entry. Every file
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* entry in the directory is copied with the UID and GID set
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* to the provided values. As an added security feature only
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* regular files (and directories ...) are copied, and no file
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* is made set-ID.
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*/
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dir = fdopendir (src_fd);
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if (NULL == dir) {
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(void) close (src_fd);
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(void) close (dst_fd);
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return -1;
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}
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if (src_orig == NULL) {
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src_orig = src->full_path;
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dst_orig = dst->full_path;
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set_orig = true;
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}
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while ((0 == err) && (ent = readdir (dir)) != NULL) {
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/*
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* Skip the "." and ".." entries
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*/
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if ((strcmp (ent->d_name, ".") != 0) &&
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(strcmp (ent->d_name, "..") != 0)) {
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char *src_name;
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char *dst_name;
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size_t src_len = strlen (ent->d_name) + 2;
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size_t dst_len = strlen (ent->d_name) + 2;
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src_len += strlen (src->full_path);
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dst_len += strlen (dst->full_path);
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src_name = (char *) malloc (src_len);
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dst_name = (char *) malloc (dst_len);
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if ((NULL == src_name) || (NULL == dst_name)) {
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err = -1;
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} else {
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/*
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* Build the filename for both the source and
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* the destination files.
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*/
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struct path_info src_entry, dst_entry;
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(void) snprintf (src_name, src_len, "%s/%s",
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src->full_path, ent->d_name);
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(void) snprintf (dst_name, dst_len, "%s/%s",
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dst->full_path, ent->d_name);
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src_entry.full_path = src_name;
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src_entry.dirfd = dirfd(dir);
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src_entry.name = ent->d_name;
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dst_entry.full_path = dst_name;
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dst_entry.dirfd = dst_fd;
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dst_entry.name = ent->d_name;
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err = copy_entry (&src_entry, &dst_entry,
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reset_selinux,
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old_uid, new_uid,
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old_gid, new_gid);
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}
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if (NULL != src_name) {
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free (src_name);
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}
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if (NULL != dst_name) {
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free (dst_name);
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}
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}
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}
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(void) closedir (dir);
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(void) close (dst_fd);
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if (set_orig) {
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src_orig = NULL;
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dst_orig = NULL;
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/* FIXME: clean links
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* Since there can be hardlinks elsewhere on the device,
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* we cannot check that all the hardlinks were found:
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assert (NULL == links);
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*/
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}
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#ifdef WITH_SELINUX
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/* Reset SELinux to create files with default contexts.
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* Note that the context is only reset on exit of copy_tree (it is
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* assumed that the program would quit without needing a restored
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* context if copy_tree failed previously), and that copy_tree can
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* be called recursively (hence the context is set on the
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* sub-functions of copy_entry).
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*/
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if (reset_selinux_file_context () != 0) {
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err = -1;
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}
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#endif /* WITH_SELINUX */
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return err;
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}
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|
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/*
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* copy_entry - copy the entry of a directory
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*
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* Copy the entry src to dst.
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* Depending on the type of entry, this function will forward the
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* request to copy_dir(), copy_symlink(), copy_hardlink(),
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* copy_special(), or copy_file().
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*
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* The access and modification time will not be modified.
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*
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* The permissions will be set to new_uid/new_gid.
|
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*
|
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* If new_uid (resp. new_gid) is equal to -1, the user (resp. group) will
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* not be modified.
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*
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* Only the files owned (resp. group-owned) by old_uid (resp.
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* old_gid) will be modified, unless old_uid (resp. old_gid) is set
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* to -1.
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*/
|
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static int copy_entry (const struct path_info *src, const struct path_info *dst,
|
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bool reset_selinux,
|
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uid_t old_uid, uid_t new_uid,
|
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gid_t old_gid, gid_t new_gid)
|
|
{
|
|
int err = 0;
|
|
struct stat sb;
|
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struct link_name *lp;
|
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struct timespec mt[2];
|
|
|
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if (fstatat(src->dirfd, src->name, &sb, AT_SYMLINK_NOFOLLOW) == -1) {
|
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/* If we cannot stat the file, do not care. */
|
|
} else {
|
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#ifdef HAVE_STRUCT_STAT_ST_ATIM
|
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mt[0].tv_sec = sb.st_atim.tv_sec;
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mt[0].tv_nsec = sb.st_atim.tv_nsec;
|
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#else /* !HAVE_STRUCT_STAT_ST_ATIM */
|
|
mt[0].tv_sec = sb.st_atime;
|
|
# ifdef HAVE_STRUCT_STAT_ST_ATIMENSEC
|
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mt[0].tv_nsec = sb.st_atimensec;
|
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# else /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */
|
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mt[0].tv_nsec = 0;
|
|
# endif /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */
|
|
#endif /* !HAVE_STRUCT_STAT_ST_ATIM */
|
|
|
|
#ifdef HAVE_STRUCT_STAT_ST_MTIM
|
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mt[1].tv_sec = sb.st_mtim.tv_sec;
|
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mt[1].tv_nsec = sb.st_mtim.tv_nsec;
|
|
#else /* !HAVE_STRUCT_STAT_ST_MTIM */
|
|
mt[1].tv_sec = sb.st_mtime;
|
|
# ifdef HAVE_STRUCT_STAT_ST_MTIMENSEC
|
|
mt[1].tv_nsec = sb.st_mtimensec;
|
|
# else /* !HAVE_STRUCT_STAT_ST_MTIMENSEC */
|
|
mt[1].tv_nsec = 0;
|
|
# endif /* !HAVE_STRUCT_STAT_ST_MTIMENSEC */
|
|
#endif /* !HAVE_STRUCT_STAT_ST_MTIM */
|
|
|
|
if (S_ISDIR (sb.st_mode)) {
|
|
err = copy_dir (src, dst, reset_selinux, &sb, mt,
|
|
old_uid, new_uid, old_gid, new_gid);
|
|
}
|
|
|
|
/*
|
|
* Copy any symbolic links
|
|
*/
|
|
|
|
else if (S_ISLNK (sb.st_mode)) {
|
|
err = copy_symlink (src, dst, reset_selinux, &sb, mt,
|
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old_uid, new_uid, old_gid, new_gid);
|
|
}
|
|
|
|
/*
|
|
* See if this is a previously copied link
|
|
*/
|
|
|
|
else if ((lp = check_link (src->full_path, &sb)) != NULL) {
|
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err = copy_hardlink (dst, reset_selinux, lp);
|
|
}
|
|
|
|
/*
|
|
* Deal with FIFOs and special files. The user really
|
|
* shouldn't have any of these, but it seems like it
|
|
* would be nice to copy everything ...
|
|
*/
|
|
|
|
else if (!S_ISREG (sb.st_mode)) {
|
|
err = copy_special (src, dst, reset_selinux, &sb, mt,
|
|
old_uid, new_uid, old_gid, new_gid);
|
|
}
|
|
|
|
/*
|
|
* Create the new file and copy the contents. The new
|
|
* file will be owned by the provided UID and GID values.
|
|
*/
|
|
|
|
else {
|
|
err = copy_file (src, dst, reset_selinux, &sb, mt,
|
|
old_uid, new_uid, old_gid, new_gid);
|
|
}
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* copy_dir - copy a directory
|
|
*
|
|
* Copy a directory (recursively) from src to dst.
|
|
*
|
|
* statp, mt, old_uid, new_uid, old_gid, and new_gid are used to set
|
|
* the access and modification and the access rights.
|
|
*
|
|
* Return 0 on success, -1 on error.
|
|
*/
|
|
static int copy_dir (const struct path_info *src, const struct path_info *dst,
|
|
bool reset_selinux,
|
|
const struct stat *statp, const struct timespec mt[],
|
|
uid_t old_uid, uid_t new_uid,
|
|
gid_t old_gid, gid_t new_gid)
|
|
{
|
|
int err = 0;
|
|
|
|
/*
|
|
* Create a new target directory, make it owned by
|
|
* the user and then recursively copy that directory.
|
|
*/
|
|
|
|
#ifdef WITH_SELINUX
|
|
if (set_selinux_file_context (dst->full_path, S_IFDIR) != 0) {
|
|
return -1;
|
|
}
|
|
#endif /* WITH_SELINUX */
|
|
if ( (mkdirat (dst->dirfd, dst->name, 0700) != 0)
|
|
|| (chownat_if_needed (dst, statp,
|
|
old_uid, new_uid, old_gid, new_gid) != 0)
|
|
|| (fchmodat (dst->dirfd, dst->name, statp->st_mode & 07777, AT_SYMLINK_NOFOLLOW) != 0)
|
|
#ifdef WITH_ACL
|
|
|| ( (perm_copy_path (src, dst, &ctx) != 0)
|
|
&& (errno != 0))
|
|
#endif /* WITH_ACL */
|
|
#ifdef WITH_ATTR
|
|
/*
|
|
* If the third parameter is NULL, all extended attributes
|
|
* except those that define Access Control Lists are copied.
|
|
* ACLs are excluded by default because copying them between
|
|
* file systems with and without ACL support needs some
|
|
* additional logic so that no unexpected permissions result.
|
|
*/
|
|
|| ( !reset_selinux
|
|
&& (attr_copy_path (src, dst, NULL, &ctx) != 0)
|
|
&& (errno != 0))
|
|
#endif /* WITH_ATTR */
|
|
|| (copy_tree_impl (src, dst, false, reset_selinux,
|
|
old_uid, new_uid, old_gid, new_gid) != 0)
|
|
|| (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0)) {
|
|
err = -1;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* readlink_malloc - wrapper for readlink
|
|
*
|
|
* return NULL on error.
|
|
* The return string shall be freed by the caller.
|
|
*/
|
|
static /*@null@*/char *readlink_malloc (const char *filename)
|
|
{
|
|
size_t size = 1024;
|
|
|
|
while (true) {
|
|
ssize_t nchars;
|
|
char *buffer = (char *) malloc (size);
|
|
if (NULL == buffer) {
|
|
return NULL;
|
|
}
|
|
|
|
nchars = readlink (filename, buffer, size);
|
|
|
|
if (nchars < 0) {
|
|
free(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
if ((size_t) nchars < size) { /* The buffer was large enough */
|
|
/* readlink does not nul-terminate */
|
|
buffer[nchars] = '\0';
|
|
return buffer;
|
|
}
|
|
|
|
/* Try again with a bigger buffer */
|
|
free (buffer);
|
|
size *= 2;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* copy_symlink - copy a symlink
|
|
*
|
|
* Copy a symlink from src to dst.
|
|
*
|
|
* statp, mt, old_uid, new_uid, old_gid, and new_gid are used to set
|
|
* the access and modification and the access rights.
|
|
*
|
|
* Return 0 on success, -1 on error.
|
|
*/
|
|
static int copy_symlink (const struct path_info *src, const struct path_info *dst,
|
|
unused bool reset_selinux,
|
|
const struct stat *statp, const struct timespec mt[],
|
|
uid_t old_uid, uid_t new_uid,
|
|
gid_t old_gid, gid_t new_gid)
|
|
{
|
|
char *oldlink;
|
|
|
|
/* copy_tree () must be the entry point */
|
|
assert (NULL != src_orig);
|
|
assert (NULL != dst_orig);
|
|
|
|
/*
|
|
* Get the name of the file which the link points
|
|
* to. If that name begins with the original
|
|
* source directory name, that part of the link
|
|
* name will be replaced with the original
|
|
* destination directory name.
|
|
*/
|
|
|
|
oldlink = readlink_malloc (src->full_path);
|
|
if (NULL == oldlink) {
|
|
return -1;
|
|
}
|
|
|
|
/* If src was a link to an entry of the src_orig directory itself,
|
|
* create a link to the corresponding entry in the dst_orig
|
|
* directory.
|
|
*/
|
|
if (strncmp (oldlink, src_orig, strlen (src_orig)) == 0) {
|
|
size_t len = strlen (dst_orig) + strlen (oldlink) - strlen (src_orig) + 1;
|
|
char *dummy = (char *) xmalloc (len);
|
|
(void) snprintf (dummy, len, "%s%s",
|
|
dst_orig,
|
|
oldlink + strlen (src_orig));
|
|
free (oldlink);
|
|
oldlink = dummy;
|
|
}
|
|
|
|
#ifdef WITH_SELINUX
|
|
if (set_selinux_file_context (dst->full_path, S_IFLNK) != 0) {
|
|
free (oldlink);
|
|
return -1;
|
|
}
|
|
#endif /* WITH_SELINUX */
|
|
if ( (symlinkat (oldlink, dst->dirfd, dst->name) != 0)
|
|
|| (chownat_if_needed (dst, statp,
|
|
old_uid, new_uid, old_gid, new_gid) != 0)) {
|
|
/* FIXME: there are no modes on symlinks, right?
|
|
* ACL could be copied, but this would be much more
|
|
* complex than calling perm_copy_file.
|
|
* Ditto for Extended Attributes.
|
|
* We currently only document that ACL and Extended
|
|
* Attributes are not copied.
|
|
*/
|
|
free (oldlink);
|
|
return -1;
|
|
}
|
|
free (oldlink);
|
|
|
|
if (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* copy_hardlink - copy a hardlink
|
|
*
|
|
* Copy a hardlink from src to dst.
|
|
*
|
|
* Return 0 on success, -1 on error.
|
|
*/
|
|
static int copy_hardlink (const struct path_info *dst,
|
|
unused bool reset_selinux,
|
|
struct link_name *lp)
|
|
{
|
|
/* FIXME: selinux, ACL, Extended Attributes needed? */
|
|
|
|
if (linkat (AT_FDCWD, lp->ln_name, dst->dirfd, dst->name, 0) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
/* If the file could be unlinked, decrement the links counter,
|
|
* and forget about this link if it was the last reference */
|
|
lp->ln_count--;
|
|
if (lp->ln_count <= 0) {
|
|
remove_link (lp);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* copy_special - copy a special file
|
|
*
|
|
* Copy a special file from src to dst.
|
|
*
|
|
* statp, mt, old_uid, new_uid, old_gid, and new_gid are used to set
|
|
* the access and modification and the access rights.
|
|
*
|
|
* Return 0 on success, -1 on error.
|
|
*/
|
|
static int copy_special (const struct path_info *src, const struct path_info *dst,
|
|
bool reset_selinux,
|
|
const struct stat *statp, const struct timespec mt[],
|
|
uid_t old_uid, uid_t new_uid,
|
|
gid_t old_gid, gid_t new_gid)
|
|
{
|
|
int err = 0;
|
|
|
|
#ifdef WITH_SELINUX
|
|
if (set_selinux_file_context (dst->full_path, statp->st_mode & S_IFMT) != 0) {
|
|
return -1;
|
|
}
|
|
#endif /* WITH_SELINUX */
|
|
|
|
if ( (mknodat (dst->dirfd, dst->name, statp->st_mode & ~07777U, statp->st_rdev) != 0)
|
|
|| (chownat_if_needed (dst, statp,
|
|
old_uid, new_uid, old_gid, new_gid) != 0)
|
|
|| (fchmodat (dst->dirfd, dst->name, statp->st_mode & 07777, AT_SYMLINK_NOFOLLOW) != 0)
|
|
#ifdef WITH_ACL
|
|
|| ( (perm_copy_path (src, dst, &ctx) != 0)
|
|
&& (errno != 0))
|
|
#endif /* WITH_ACL */
|
|
#ifdef WITH_ATTR
|
|
/*
|
|
* If the third parameter is NULL, all extended attributes
|
|
* except those that define Access Control Lists are copied.
|
|
* ACLs are excluded by default because copying them between
|
|
* file systems with and without ACL support needs some
|
|
* additional logic so that no unexpected permissions result.
|
|
*/
|
|
|| ( !reset_selinux
|
|
&& (attr_copy_path (src, dst, NULL, &ctx) != 0)
|
|
&& (errno != 0))
|
|
#endif /* WITH_ATTR */
|
|
|| (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0)) {
|
|
err = -1;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* full_write - write entire buffer
|
|
*
|
|
* Write up to count bytes from the buffer starting at buf to the
|
|
* file referred to by the file descriptor fd.
|
|
* Retry in case of a short write.
|
|
*
|
|
* Returns the number of bytes written on success, -1 on error.
|
|
*/
|
|
static ssize_t full_write(int fd, const void *buf, size_t count) {
|
|
ssize_t written = 0;
|
|
|
|
while (count > 0) {
|
|
ssize_t res;
|
|
|
|
res = write(fd, buf, count);
|
|
if (res < 0) {
|
|
if (errno == EINTR) {
|
|
continue;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
if (res == 0) {
|
|
break;
|
|
}
|
|
|
|
written += res;
|
|
buf = (const unsigned char*)buf + res;
|
|
count -= (size_t)res;
|
|
}
|
|
|
|
return written;
|
|
}
|
|
|
|
/*
|
|
* copy_file - copy a file
|
|
*
|
|
* Copy a file from src to dst.
|
|
*
|
|
* statp, mt, old_uid, new_uid, old_gid, and new_gid are used to set
|
|
* the access and modification and the access rights.
|
|
*
|
|
* Return 0 on success, -1 on error.
|
|
*/
|
|
static int copy_file (const struct path_info *src, const struct path_info *dst,
|
|
bool reset_selinux,
|
|
const struct stat *statp, const struct timespec mt[],
|
|
uid_t old_uid, uid_t new_uid,
|
|
gid_t old_gid, gid_t new_gid)
|
|
{
|
|
int err = 0;
|
|
int ifd;
|
|
int ofd;
|
|
|
|
ifd = openat (src->dirfd, src->name, O_RDONLY|O_NOFOLLOW|O_CLOEXEC);
|
|
if (ifd < 0) {
|
|
return -1;
|
|
}
|
|
#ifdef WITH_SELINUX
|
|
if (set_selinux_file_context (dst->full_path, S_IFREG) != 0) {
|
|
(void) close (ifd);
|
|
return -1;
|
|
}
|
|
#endif /* WITH_SELINUX */
|
|
ofd = openat (dst->dirfd, dst->name, O_WRONLY | O_CREAT | O_EXCL | O_TRUNC | O_NOFOLLOW | O_CLOEXEC, 0600);
|
|
if ( (ofd < 0)
|
|
|| (fchown_if_needed (ofd, statp,
|
|
old_uid, new_uid, old_gid, new_gid) != 0)
|
|
|| (fchmod (ofd, statp->st_mode & 07777) != 0)
|
|
#ifdef WITH_ACL
|
|
|| ( (perm_copy_fd (src->full_path, ifd, dst->full_path, ofd, &ctx) != 0)
|
|
&& (errno != 0))
|
|
#endif /* WITH_ACL */
|
|
#ifdef WITH_ATTR
|
|
/*
|
|
* If the third parameter is NULL, all extended attributes
|
|
* except those that define Access Control Lists are copied.
|
|
* ACLs are excluded by default because copying them between
|
|
* file systems with and without ACL support needs some
|
|
* additional logic so that no unexpected permissions result.
|
|
*/
|
|
|| ( !reset_selinux
|
|
&& (attr_copy_fd (src->full_path, ifd, dst->full_path, ofd, NULL, &ctx) != 0)
|
|
&& (errno != 0))
|
|
#endif /* WITH_ATTR */
|
|
) {
|
|
if (ofd >= 0) {
|
|
(void) close (ofd);
|
|
}
|
|
(void) close (ifd);
|
|
return -1;
|
|
}
|
|
|
|
while (true) {
|
|
char buf[8192];
|
|
ssize_t cnt;
|
|
|
|
cnt = read (ifd, buf, sizeof buf);
|
|
if (cnt < 0) {
|
|
if (errno == EINTR) {
|
|
continue;
|
|
}
|
|
(void) close (ofd);
|
|
(void) close (ifd);
|
|
return -1;
|
|
}
|
|
if (cnt == 0) {
|
|
break;
|
|
}
|
|
|
|
if (full_write (ofd, buf, (size_t)cnt) < 0) {
|
|
(void) close (ofd);
|
|
(void) close (ifd);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
(void) close (ifd);
|
|
if (close (ofd) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
if (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
#define def_chown_if_needed(chown_function, type_dst) \
|
|
static int chown_function ## _if_needed (type_dst dst, \
|
|
const struct stat *statp, \
|
|
uid_t old_uid, uid_t new_uid, \
|
|
gid_t old_gid, gid_t new_gid) \
|
|
{ \
|
|
uid_t tmpuid = (uid_t) -1; \
|
|
gid_t tmpgid = (gid_t) -1; \
|
|
\
|
|
/* Use new_uid if old_uid is set to -1 or if the file was \
|
|
* owned by the user. */ \
|
|
if (((uid_t) -1 == old_uid) || (statp->st_uid == old_uid)) { \
|
|
tmpuid = new_uid; \
|
|
} \
|
|
/* Otherwise, or if new_uid was set to -1, we keep the same \
|
|
* owner. */ \
|
|
if ((uid_t) -1 == tmpuid) { \
|
|
tmpuid = statp->st_uid; \
|
|
} \
|
|
\
|
|
if (((gid_t) -1 == old_gid) || (statp->st_gid == old_gid)) { \
|
|
tmpgid = new_gid; \
|
|
} \
|
|
if ((gid_t) -1 == tmpgid) { \
|
|
tmpgid = statp->st_gid; \
|
|
} \
|
|
\
|
|
return chown_function (dst, tmpuid, tmpgid); \
|
|
}
|
|
|
|
def_chown_if_needed (fchown, int)
|
|
|
|
static int chownat_if_needed (const struct path_info *dst,
|
|
const struct stat *statp,
|
|
uid_t old_uid, uid_t new_uid,
|
|
gid_t old_gid, gid_t new_gid)
|
|
{
|
|
uid_t tmpuid = (uid_t) -1;
|
|
gid_t tmpgid = (gid_t) -1;
|
|
|
|
/* Use new_uid if old_uid is set to -1 or if the file was
|
|
* owned by the user. */
|
|
if (((uid_t) -1 == old_uid) || (statp->st_uid == old_uid)) {
|
|
tmpuid = new_uid;
|
|
}
|
|
/* Otherwise, or if new_uid was set to -1, we keep the same
|
|
* owner. */
|
|
if ((uid_t) -1 == tmpuid) {
|
|
tmpuid = statp->st_uid;
|
|
}
|
|
|
|
if (((gid_t) -1 == old_gid) || (statp->st_gid == old_gid)) {
|
|
tmpgid = new_gid;
|
|
}
|
|
if ((gid_t) -1 == tmpgid) {
|
|
tmpgid = statp->st_gid;
|
|
}
|
|
|
|
return fchownat (dst->dirfd, dst->name, tmpuid, tmpgid, AT_SYMLINK_NOFOLLOW);
|
|
}
|
|
|
|
/*
|
|
* copy_tree - copy files in a directory tree
|
|
*
|
|
* copy_tree() walks a directory tree and copies ordinary files
|
|
* as it goes.
|
|
*
|
|
* When reset_selinux is enabled, extended attributes (and thus
|
|
* SELinux attributes) are not copied.
|
|
*
|
|
* old_uid and new_uid are used to set the ownership of the copied
|
|
* files. Unless old_uid is set to -1, only the files owned by
|
|
* old_uid have their ownership changed to new_uid. In addition, if
|
|
* new_uid is set to -1, no ownership will be changed.
|
|
*
|
|
* The same logic applies for the group-ownership and
|
|
* old_gid/new_gid.
|
|
*/
|
|
int copy_tree (const char *src_root, const char *dst_root,
|
|
bool copy_root, bool reset_selinux,
|
|
uid_t old_uid, uid_t new_uid,
|
|
gid_t old_gid, gid_t new_gid)
|
|
{
|
|
const struct path_info src = {
|
|
.full_path = src_root,
|
|
.dirfd = AT_FDCWD,
|
|
.name = src_root
|
|
};
|
|
const struct path_info dst = {
|
|
.full_path = dst_root,
|
|
.dirfd = AT_FDCWD,
|
|
.name = dst_root
|
|
};
|
|
|
|
return copy_tree_impl(&src, &dst, copy_root, reset_selinux,
|
|
old_uid, new_uid, old_gid, new_gid);
|
|
}
|