emo/shadow
1
0
Fork 0
Code Issues Pull Requests Packages Releases Activity
cfc981df2a
shadow/libmisc/copydir.c
Christian Göttsche faeab50e71 Avoid races in copy_tree() 
Use *at() functions to pin the directory operating in to avoid being
redirected by unprivileged users replacing parts of paths by symlinks to
privileged files.

Introduce a path_info struct with the full path and dirfd and name
information for *at() functions, since the full path is needed for link
resolution, SELinux label lookup and ACL attributes.
2022-08-17 12:34:01 -05:00

976 lines
27 KiB
C
Raw Blame History

/*
* SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 2001, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <assert.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <fcntl.h>
#include <stdio.h>
#include "prototypes.h"
#include "defines.h"
#ifdef WITH_SELINUX
#include <selinux/selinux.h>
#endif /* WITH_SELINUX */
#if defined(WITH_ACL) || defined(WITH_ATTR)
#include <stdarg.h>
#include <attr/error_context.h>
#endif /* WITH_ACL || WITH_ATTR */
#ifdef WITH_ACL
#include <acl/libacl.h>
#endif /* WITH_ACL */
#ifdef WITH_ATTR
#include <attr/libattr.h>
#endif /* WITH_ATTR */
#include "shadowlog.h"
static /*@null@*/const char *src_orig;
static /*@null@*/const char *dst_orig;
struct link_name {
dev_t ln_dev;
ino_t ln_ino;
nlink_t ln_count;
char *ln_name;
/*@dependent@*/struct link_name *ln_next;
};
static /*@exposed@*/struct link_name *links;
struct path_info {
const char *full_path;
int dirfd;
const char *name;
};
static int copy_entry (const struct path_info *src, const struct path_info *dst,
bool reset_selinux,
uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid);
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);
static /*@null@*/char *readlink_malloc (const char *filename);
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);
static int copy_hardlink (const struct path_info *dst,
unused bool reset_selinux,
struct link_name *lp);
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);
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);
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);
static int fchown_if_needed (int fdst, const struct stat *statp,
uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid);
#if defined(WITH_ACL) || defined(WITH_ATTR)
/*
* error_acl - format the error messages for the ACL and EQ libraries.
*/
format_attr(printf, 2, 3)
static void error_acl (unused struct error_context *ctx, const char *fmt, ...)
{
va_list ap;
FILE *shadow_logfd = log_get_logfd();
/* ignore the case when destination does not support ACLs
* or extended attributes */
if (ENOTSUP == errno) {
errno = 0;
return;
}
va_start (ap, fmt);
(void) fprintf (shadow_logfd, _("%s: "), log_get_progname());
if (vfprintf (shadow_logfd, fmt, ap) != 0) {
(void) fputs (_(": "), shadow_logfd);
}
(void) fprintf (shadow_logfd, "%s\n", strerror (errno));
va_end (ap);
}
static struct error_context ctx = {
error_acl, NULL, NULL
};
#endif /* WITH_ACL || WITH_ATTR */
#ifdef WITH_ACL
static int perm_copy_path(const struct path_info *src,
const struct path_info *dst,
struct error_context *errctx)
{
int src_fd, dst_fd, ret;
src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
if (src_fd < 0) {
return -1;
}
dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
if (dst_fd < 0) {
(void) close (src_fd);
return -1;
}
ret = perm_copy_fd(src->full_path, src_fd, dst->full_path, dst_fd, errctx);
(void) close (src_fd);
(void) close (dst_fd);
return ret;
}
#endif /* WITH_ACL */
#ifdef WITH_ATTR
static int attr_copy_path(const struct path_info *src,
const struct path_info *dst,
int (*callback) (const char *, struct error_context *),
struct error_context *errctx)
{
int src_fd, dst_fd, ret;
src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
if (src_fd < 0) {
return -1;
}
dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
if (dst_fd < 0) {
(void) close (src_fd);
return -1;
}
ret = attr_copy_fd(src->full_path, src_fd, dst->full_path, dst_fd, callback, errctx);
(void) close (src_fd);
(void) close (dst_fd);
return ret;
}
#endif /* WITH_ATTR */
/*
* remove_link - delete a link from the linked list
*/
static void remove_link (/*@only@*/struct link_name *ln)
{
struct link_name *lp;
if (links == ln) {
links = ln->ln_next;
free (ln->ln_name);
free (ln);
return;
}
for (lp = links; NULL !=lp; lp = lp->ln_next) {
if (lp->ln_next == ln) {
break;
}
}
if (NULL == lp) {
free (ln->ln_name);
free (ln);
return;
}
lp->ln_next = lp->ln_next->ln_next;
free (ln->ln_name);
free (ln);
}
/*
* check_link - see if a file is really a link
*/
static /*@exposed@*/ /*@null@*/struct link_name *check_link (const char *name, const struct stat *sb)
{
struct link_name *lp;
size_t src_len;
size_t dst_len;
size_t name_len;
size_t len;
/* copy_tree () must be the entry point */
assert (NULL != src_orig);
assert (NULL != dst_orig);
for (lp = links; NULL != lp; lp = lp->ln_next) {
if ((lp->ln_dev == sb->st_dev) && (lp->ln_ino == sb->st_ino)) {
return lp;
}
}
if (sb->st_nlink == 1) {
return NULL;
}
lp = (struct link_name *) xmalloc (sizeof *lp);
src_len = strlen (src_orig);
dst_len = strlen (dst_orig);
name_len = strlen (name);
lp->ln_dev = sb->st_dev;
lp->ln_ino = sb->st_ino;
lp->ln_count = sb->st_nlink;
len = name_len - src_len + dst_len + 1;
lp->ln_name = (char *) xmalloc (len);
(void) snprintf (lp->ln_name, len, "%s%s", dst_orig, name + src_len);
lp->ln_next = links;
links = lp;
return NULL;
}
static int copy_tree_impl (const struct path_info *src, const struct path_info *dst,
bool copy_root, bool reset_selinux,
uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid)
{
int dst_fd, src_fd, err = 0;
bool set_orig = false;
const struct dirent *ent;
DIR *dir;
if (copy_root) {
struct stat sb;
if ( fstatat (dst->dirfd, dst->name, &sb, 0) == 0
|| errno != ENOENT) {
return -1;
}
if (fstatat (src->dirfd, src->name, &sb, AT_SYMLINK_NOFOLLOW) == -1) {
return -1;
}
if (!S_ISDIR (sb.st_mode)) {
fprintf (log_get_logfd(),
"%s: %s is not a directory",
log_get_progname(), src->full_path);
return -1;
}
return copy_entry (src, dst, reset_selinux,
old_uid, new_uid, old_gid, new_gid);
}
/*
* Make certain both directories exist. This routine is called
* after the home directory is created, or recursively after the
* target is created. It assumes the target directory exists.
*/
src_fd = openat (src->dirfd, src->name, O_DIRECTORY | O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
if (src_fd < 0) {
return -1;
}
dst_fd = openat (dst->dirfd, dst->name, O_DIRECTORY | O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
if (dst_fd < 0) {
(void) close (src_fd);
return -1;
}
/*
* Open the source directory and read each entry. Every file
* entry in the directory is copied with the UID and GID set
* to the provided values. As an added security feature only
* regular files (and directories ...) are copied, and no file
* is made set-ID.
*/
dir = fdopendir (src_fd);
if (NULL == dir) {
(void) close (src_fd);
(void) close (dst_fd);
return -1;
}
if (src_orig == NULL) {
src_orig = src->full_path;
dst_orig = dst->full_path;
set_orig = true;
}
while ((0 == err) && (ent = readdir (dir)) != NULL) {
/*
* Skip the "." and ".." entries
*/
if ((strcmp (ent->d_name, ".") != 0) &&
(strcmp (ent->d_name, "..") != 0)) {
char *src_name;
char *dst_name;
size_t src_len = strlen (ent->d_name) + 2;
size_t dst_len = strlen (ent->d_name) + 2;
src_len += strlen (src->full_path);
dst_len += strlen (dst->full_path);
src_name = (char *) malloc (src_len);
dst_name = (char *) malloc (dst_len);
if ((NULL == src_name) || (NULL == dst_name)) {
err = -1;
} else {
/*
* Build the filename for both the source and
* the destination files.
*/
struct path_info src_entry, dst_entry;
(void) snprintf (src_name, src_len, "%s/%s",
src->full_path, ent->d_name);
(void) snprintf (dst_name, dst_len, "%s/%s",
dst->full_path, ent->d_name);
src_entry.full_path = src_name;
src_entry.dirfd = dirfd(dir);
src_entry.name = ent->d_name;
dst_entry.full_path = dst_name;
dst_entry.dirfd = dst_fd;
dst_entry.name = ent->d_name;
err = copy_entry (&src_entry, &dst_entry,
reset_selinux,
old_uid, new_uid,
old_gid, new_gid);
}
if (NULL != src_name) {
free (src_name);
}
if (NULL != dst_name) {
free (dst_name);
}
}
}
(void) closedir (dir);
(void) close (dst_fd);
if (set_orig) {
src_orig = NULL;
dst_orig = NULL;
/* FIXME: clean links
* Since there can be hardlinks elsewhere on the device,
* we cannot check that all the hardlinks were found:
assert (NULL == links);
*/
}
#ifdef WITH_SELINUX
/* Reset SELinux to create files with default contexts.
* Note that the context is only reset on exit of copy_tree (it is
* assumed that the program would quit without needing a restored
* context if copy_tree failed previously), and that copy_tree can
* be called recursively (hence the context is set on the
* sub-functions of copy_entry).
*/
if (reset_selinux_file_context () != 0) {
err = -1;
}
#endif /* WITH_SELINUX */
return err;
}
/*
* copy_entry - copy the entry of a directory
*
* Copy the entry src to dst.
* Depending on the type of entry, this function will forward the
* request to copy_dir(), copy_symlink(), copy_hardlink(),
* copy_special(), or copy_file().
*
* The access and modification time will not be modified.
*
* The permissions will be set to new_uid/new_gid.
*
* If new_uid (resp. new_gid) is equal to -1, the user (resp. group) will
* not be modified.
*
* Only the files owned (resp. group-owned) by old_uid (resp.
* old_gid) will be modified, unless old_uid (resp. old_gid) is set
* to -1.
*/
static int copy_entry (const struct path_info *src, const struct path_info *dst,
bool reset_selinux,
uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid)
{
int err = 0;
struct stat sb;
struct link_name *lp;
struct timespec mt[2];
if (fstatat(src->dirfd, src->name, &sb, AT_SYMLINK_NOFOLLOW) == -1) {
/* If we cannot stat the file, do not care. */
} else {
#ifdef HAVE_STRUCT_STAT_ST_ATIM
mt[0].tv_sec = sb.st_atim.tv_sec;
mt[0].tv_nsec = sb.st_atim.tv_nsec;
#else /* !HAVE_STRUCT_STAT_ST_ATIM */
mt[0].tv_sec = sb.st_atime;
# ifdef HAVE_STRUCT_STAT_ST_ATIMENSEC
mt[0].tv_nsec = sb.st_atimensec;
# else /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */
mt[0].tv_nsec = 0;
# endif /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */
#endif /* !HAVE_STRUCT_STAT_ST_ATIM */
#ifdef HAVE_STRUCT_STAT_ST_MTIM
mt[1].tv_sec = sb.st_mtim.tv_sec;
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,
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) {
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, statp->st_mode) != 0)
|| (chownat_if_needed (dst, statp,
old_uid, new_uid, old_gid, new_gid) != 0)
#ifdef WITH_ACL
|| ( (perm_copy_path (src, dst, &ctx) != 0)
&& (errno != 0))
#else /* !WITH_ACL */
|| (chmod (dst, statp->st_mode) != 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)
#ifdef WITH_ACL
|| ( (perm_copy_path (src, dst, &ctx) != 0)
&& (errno != 0))
#else /* !WITH_ACL */
|| (fchmodat (dst->dirfd, dst->name, statp->st_mode & 07777, AT_SYMLINK_NOFOLLOW) != 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, statp->st_mode & 07777);
if ( (ofd < 0)
|| (fchown_if_needed (ofd, statp,
old_uid, new_uid, old_gid, new_gid) != 0)
#ifdef WITH_ACL
|| ( (perm_copy_fd (src->full_path, ifd, dst->full_path, ofd, &ctx) != 0)
&& (errno != 0))
#else /* !WITH_ACL */
|| (fchmod (ofd, statp->st_mode & 07777) != 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);
}
Reference in New Issue View Git Blame Copy Permalink