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Avoid races in copy_tree()

Browse Source 
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.
This commit is contained in:
Christian Göttsche 2022-08-05 17:57:32 +02:00 committed by Serge Hallyn
parent 6cbec2d0aa
commit faeab50e71
1 changed files with 220 additions and 114 deletions
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334
libmisc/copydir.c
View File

@ -47,40 +47,43 @@ struct link_name {
}; };
static /*@exposed@*/struct link_name *links; static /*@exposed@*/struct link_name *links;
static int copy_entry (const char *src, const char *dst, 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, bool reset_selinux,
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
static int copy_dir (const char *src, const char *dst, static int copy_dir (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
static /*@null@*/char *readlink_malloc (const char *filename); static /*@null@*/char *readlink_malloc (const char *filename);
static int copy_symlink (const char *src, const char *dst, static int copy_symlink (const struct path_info *src, const struct path_info *dst,
unused bool reset_selinux, unused bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
static int copy_hardlink (const char *dst, static int copy_hardlink (const struct path_info *dst,
unused bool reset_selinux, unused bool reset_selinux,
struct link_name *lp); struct link_name *lp);
static int copy_special (const char *src, const char *dst, static int copy_special (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
static int copy_file (const char *src, const char *dst, static int copy_file (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
static int chown_if_needed (const char *dst, const struct stat *statp, static int chownat_if_needed (const struct path_info *dst, const struct stat *statp,
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
static int lchown_if_needed (const char *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, static int fchown_if_needed (int fdst, const struct stat *statp,
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid); gid_t old_gid, gid_t new_gid);
@ -116,6 +119,57 @@ static struct error_context ctx = {
}; };
#endif /* WITH_ACL || WITH_ATTR */ #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 * remove_link - delete a link from the linked list
*/ */
@ -188,51 +242,36 @@ static /*@exposed@*/ /*@null@*/struct link_name *check_link (const char *name, c
return NULL; return NULL;
} }
/* static int copy_tree_impl (const struct path_info *src, const struct path_info *dst,
* 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, bool copy_root, bool reset_selinux,
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid) gid_t old_gid, gid_t new_gid)
{ {
int err = 0; int dst_fd, src_fd, err = 0;
bool set_orig = false; bool set_orig = false;
struct dirent *ent; const struct dirent *ent;
DIR *dir; DIR *dir;
if (copy_root) { if (copy_root) {
struct stat sb; struct stat sb;
if (access (dst_root, F_OK) == 0) {
if ( fstatat (dst->dirfd, dst->name, &sb, 0) == 0
|| errno != ENOENT) {
return -1; return -1;
} }
if (lstat (src_root, &sb) == -1) { if (fstatat (src->dirfd, src->name, &sb, AT_SYMLINK_NOFOLLOW) == -1) {
return -1; return -1;
} }
if (!S_ISDIR (sb.st_mode)) { if (!S_ISDIR (sb.st_mode)) {
fprintf (log_get_logfd(), fprintf (log_get_logfd(),
"%s: %s is not a directory", "%s: %s is not a directory",
log_get_progname(), src_root); log_get_progname(), src->full_path);
return -1; return -1;
} }
return copy_entry (src_root, dst_root, reset_selinux, return copy_entry (src, dst, reset_selinux,
old_uid, new_uid, old_gid, new_gid); old_uid, new_uid, old_gid, new_gid);
} }
@ -242,8 +281,14 @@ int copy_tree (const char *src_root, const char *dst_root,
* target is created. It assumes the target directory exists. * target is created. It assumes the target directory exists.
*/ */
if ( (access (src_root, F_OK) != 0) src_fd = openat (src->dirfd, src->name, O_DIRECTORY | O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
|| (access (dst_root, F_OK) != 0)) { 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; return -1;
} }
@ -254,14 +299,16 @@ int copy_tree (const char *src_root, const char *dst_root,
* regular files (and directories ...) are copied, and no file * regular files (and directories ...) are copied, and no file
* is made set-ID. * is made set-ID.
*/ */
dir = opendir (src_root); dir = fdopendir (src_fd);
if (NULL == dir) { if (NULL == dir) {
(void) close (src_fd);
(void) close (dst_fd);
return -1; return -1;
} }
if (src_orig == NULL) { if (src_orig == NULL) {
src_orig = src_root; src_orig = src->full_path;
dst_orig = dst_root; dst_orig = dst->full_path;
set_orig = true; set_orig = true;
} }
while ((0 == err) && (ent = readdir (dir)) != NULL) { while ((0 == err) && (ent = readdir (dir)) != NULL) {
@ -274,8 +321,8 @@ int copy_tree (const char *src_root, const char *dst_root,
char *dst_name; char *dst_name;
size_t src_len = strlen (ent->d_name) + 2; size_t src_len = strlen (ent->d_name) + 2;
size_t dst_len = strlen (ent->d_name) + 2; size_t dst_len = strlen (ent->d_name) + 2;
src_len += strlen (src_root); src_len += strlen (src->full_path);
dst_len += strlen (dst_root); dst_len += strlen (dst->full_path);
src_name = (char *) malloc (src_len); src_name = (char *) malloc (src_len);
dst_name = (char *) malloc (dst_len); dst_name = (char *) malloc (dst_len);
@ -287,12 +334,22 @@ int copy_tree (const char *src_root, const char *dst_root,
* Build the filename for both the source and * Build the filename for both the source and
* the destination files. * the destination files.
*/ */
(void) snprintf (src_name, src_len, "%s/%s", struct path_info src_entry, dst_entry;
src_root, ent->d_name);
(void) snprintf (dst_name, dst_len, "%s/%s",
dst_root, ent->d_name);
err = copy_entry (src_name, dst_name, (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, reset_selinux,
old_uid, new_uid, old_uid, new_uid,
old_gid, new_gid); old_gid, new_gid);
@ -306,6 +363,7 @@ int copy_tree (const char *src_root, const char *dst_root,
} }
} }
(void) closedir (dir); (void) closedir (dir);
(void) close (dst_fd);
if (set_orig) { if (set_orig) {
src_orig = NULL; src_orig = NULL;
@ -352,7 +410,7 @@ int copy_tree (const char *src_root, const char *dst_root,
* old_gid) will be modified, unless old_uid (resp. old_gid) is set * old_gid) will be modified, unless old_uid (resp. old_gid) is set
* to -1. * to -1.
*/ */
static int copy_entry (const char *src, const char *dst, static int copy_entry (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid) gid_t old_gid, gid_t new_gid)
@ -360,32 +418,32 @@ static int copy_entry (const char *src, const char *dst,
int err = 0; int err = 0;
struct stat sb; struct stat sb;
struct link_name *lp; struct link_name *lp;
struct timeval mt[2]; struct timespec mt[2];
if (lstat (src, &sb) == -1) { if (fstatat(src->dirfd, src->name, &sb, AT_SYMLINK_NOFOLLOW) == -1) {
/* If we cannot stat the file, do not care. */ /* If we cannot stat the file, do not care. */
} else { } else {
#ifdef HAVE_STRUCT_STAT_ST_ATIM #ifdef HAVE_STRUCT_STAT_ST_ATIM
mt[0].tv_sec = sb.st_atim.tv_sec; mt[0].tv_sec = sb.st_atim.tv_sec;
mt[0].tv_usec = sb.st_atim.tv_nsec / 1000; mt[0].tv_nsec = sb.st_atim.tv_nsec;
#else /* !HAVE_STRUCT_STAT_ST_ATIM */ #else /* !HAVE_STRUCT_STAT_ST_ATIM */
mt[0].tv_sec = sb.st_atime; mt[0].tv_sec = sb.st_atime;
# ifdef HAVE_STRUCT_STAT_ST_ATIMENSEC # ifdef HAVE_STRUCT_STAT_ST_ATIMENSEC
mt[0].tv_usec = sb.st_atimensec / 1000; mt[0].tv_nsec = sb.st_atimensec;
# else /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */ # else /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */
mt[0].tv_usec = 0; mt[0].tv_nsec = 0;
# endif /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */ # endif /* !HAVE_STRUCT_STAT_ST_ATIMENSEC */
#endif /* !HAVE_STRUCT_STAT_ST_ATIM */ #endif /* !HAVE_STRUCT_STAT_ST_ATIM */
#ifdef HAVE_STRUCT_STAT_ST_MTIM #ifdef HAVE_STRUCT_STAT_ST_MTIM
mt[1].tv_sec = sb.st_mtim.tv_sec; mt[1].tv_sec = sb.st_mtim.tv_sec;
mt[1].tv_usec = sb.st_mtim.tv_nsec / 1000; mt[1].tv_nsec = sb.st_mtim.tv_nsec;
#else /* !HAVE_STRUCT_STAT_ST_MTIM */ #else /* !HAVE_STRUCT_STAT_ST_MTIM */
mt[1].tv_sec = sb.st_mtime; mt[1].tv_sec = sb.st_mtime;
# ifdef HAVE_STRUCT_STAT_ST_MTIMENSEC # ifdef HAVE_STRUCT_STAT_ST_MTIMENSEC
mt[1].tv_usec = sb.st_mtimensec / 1000; mt[1].tv_nsec = sb.st_mtimensec;
# else /* !HAVE_STRUCT_STAT_ST_MTIMENSEC */ # else /* !HAVE_STRUCT_STAT_ST_MTIMENSEC */
mt[1].tv_usec = 0; mt[1].tv_nsec = 0;
# endif /* !HAVE_STRUCT_STAT_ST_MTIMENSEC */ # endif /* !HAVE_STRUCT_STAT_ST_MTIMENSEC */
#endif /* !HAVE_STRUCT_STAT_ST_MTIM */ #endif /* !HAVE_STRUCT_STAT_ST_MTIM */
@ -407,7 +465,7 @@ static int copy_entry (const char *src, const char *dst,
* See if this is a previously copied link * See if this is a previously copied link
*/ */
else if ((lp = check_link (src, &sb)) != NULL) { else if ((lp = check_link (src->full_path, &sb)) != NULL) {
err = copy_hardlink (dst, reset_selinux, lp); err = copy_hardlink (dst, reset_selinux, lp);
} }
@ -446,9 +504,9 @@ static int copy_entry (const char *src, const char *dst,
* *
* Return 0 on success, -1 on error. * Return 0 on success, -1 on error.
*/ */
static int copy_dir (const char *src, const char *dst, static int copy_dir (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid) gid_t old_gid, gid_t new_gid)
{ {
@ -460,15 +518,15 @@ static int copy_dir (const char *src, const char *dst,
*/ */
#ifdef WITH_SELINUX #ifdef WITH_SELINUX
if (set_selinux_file_context (dst, S_IFDIR) != 0) { if (set_selinux_file_context (dst->full_path, S_IFDIR) != 0) {
return -1; return -1;
} }
#endif /* WITH_SELINUX */ #endif /* WITH_SELINUX */
if ( (mkdir (dst, statp->st_mode) != 0) if ( (mkdirat (dst->dirfd, dst->name, statp->st_mode) != 0)
|| (chown_if_needed (dst, statp, || (chownat_if_needed (dst, statp,
old_uid, new_uid, old_gid, new_gid) != 0) old_uid, new_uid, old_gid, new_gid) != 0)
#ifdef WITH_ACL #ifdef WITH_ACL
|| ( (perm_copy_file (src, dst, &ctx) != 0) || ( (perm_copy_path (src, dst, &ctx) != 0)
&& (errno != 0)) && (errno != 0))
#else /* !WITH_ACL */ #else /* !WITH_ACL */
|| (chmod (dst, statp->st_mode) != 0) || (chmod (dst, statp->st_mode) != 0)
@ -482,12 +540,12 @@ static int copy_dir (const char *src, const char *dst,
* additional logic so that no unexpected permissions result. * additional logic so that no unexpected permissions result.
*/ */
|| ( !reset_selinux || ( !reset_selinux
&& (attr_copy_file (src, dst, NULL, &ctx) != 0) && (attr_copy_path (src, dst, NULL, &ctx) != 0)
&& (errno != 0)) && (errno != 0))
#endif /* WITH_ATTR */ #endif /* WITH_ATTR */
|| (copy_tree (src, dst, false, reset_selinux, || (copy_tree_impl (src, dst, false, reset_selinux,
old_uid, new_uid, old_gid, new_gid) != 0) old_uid, new_uid, old_gid, new_gid) != 0)
|| (utimes (dst, mt) != 0)) { || (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0)) {
err = -1; err = -1;
} }
@ -540,9 +598,9 @@ static /*@null@*/char *readlink_malloc (const char *filename)
* *
* Return 0 on success, -1 on error. * Return 0 on success, -1 on error.
*/ */
static int copy_symlink (const char *src, const char *dst, static int copy_symlink (const struct path_info *src, const struct path_info *dst,
unused bool reset_selinux, unused bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid) gid_t old_gid, gid_t new_gid)
{ {
@ -560,7 +618,7 @@ static int copy_symlink (const char *src, const char *dst,
* destination directory name. * destination directory name.
*/ */
oldlink = readlink_malloc (src); oldlink = readlink_malloc (src->full_path);
if (NULL == oldlink) { if (NULL == oldlink) {
return -1; return -1;
} }
@ -580,13 +638,13 @@ static int copy_symlink (const char *src, const char *dst,
} }
#ifdef WITH_SELINUX #ifdef WITH_SELINUX
if (set_selinux_file_context (dst, S_IFLNK) != 0) { if (set_selinux_file_context (dst->full_path, S_IFLNK) != 0) {
free (oldlink); free (oldlink);
return -1; return -1;
} }
#endif /* WITH_SELINUX */ #endif /* WITH_SELINUX */
if ( (symlink (oldlink, dst) != 0) if ( (symlinkat (oldlink, dst->dirfd, dst->name) != 0)
|| (lchown_if_needed (dst, statp, || (chownat_if_needed (dst, statp,
old_uid, new_uid, old_gid, new_gid) != 0)) { old_uid, new_uid, old_gid, new_gid) != 0)) {
/* FIXME: there are no modes on symlinks, right? /* FIXME: there are no modes on symlinks, right?
* ACL could be copied, but this would be much more * ACL could be copied, but this would be much more
@ -600,14 +658,9 @@ static int copy_symlink (const char *src, const char *dst,
} }
free (oldlink); free (oldlink);
#ifdef HAVE_LUTIMES if (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0) {
/* 2007-10-18: We don't care about return -1;
* exit status of lutimes because }
* it returns ENOSYS on many system
* - not implemented
*/
(void) lutimes (dst, mt);
#endif /* HAVE_LUTIMES */
return 0; return 0;
} }
@ -619,13 +672,13 @@ static int copy_symlink (const char *src, const char *dst,
* *
* Return 0 on success, -1 on error. * Return 0 on success, -1 on error.
*/ */
static int copy_hardlink (const char *dst, static int copy_hardlink (const struct path_info *dst,
unused bool reset_selinux, unused bool reset_selinux,
struct link_name *lp) struct link_name *lp)
{ {
/* FIXME: selinux, ACL, Extended Attributes needed? */ /* FIXME: selinux, ACL, Extended Attributes needed? */
if (link (lp->ln_name, dst) != 0) { if (linkat (AT_FDCWD, lp->ln_name, dst->dirfd, dst->name, 0) != 0) {
return -1; return -1;
} }
@ -649,28 +702,28 @@ static int copy_hardlink (const char *dst,
* *
* Return 0 on success, -1 on error. * Return 0 on success, -1 on error.
*/ */
static int copy_special (const char *src, const char *dst, static int copy_special (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid) gid_t old_gid, gid_t new_gid)
{ {
int err = 0; int err = 0;
#ifdef WITH_SELINUX #ifdef WITH_SELINUX
if (set_selinux_file_context (dst, statp->st_mode & S_IFMT) != 0) { if (set_selinux_file_context (dst->full_path, statp->st_mode & S_IFMT) != 0) {
return -1; return -1;
} }
#endif /* WITH_SELINUX */ #endif /* WITH_SELINUX */
if ( (mknod (dst, statp->st_mode & ~07777U, statp->st_rdev) != 0) if ( (mknodat (dst->dirfd, dst->name, statp->st_mode & ~07777U, statp->st_rdev) != 0)
|| (chown_if_needed (dst, statp, || (chownat_if_needed (dst, statp,
old_uid, new_uid, old_gid, new_gid) != 0) old_uid, new_uid, old_gid, new_gid) != 0)
#ifdef WITH_ACL #ifdef WITH_ACL
|| ( (perm_copy_file (src, dst, &ctx) != 0) || ( (perm_copy_path (src, dst, &ctx) != 0)
&& (errno != 0)) && (errno != 0))
#else /* !WITH_ACL */ #else /* !WITH_ACL */
|| (chmod (dst, statp->st_mode & 07777) != 0) || (fchmodat (dst->dirfd, dst->name, statp->st_mode & 07777, AT_SYMLINK_NOFOLLOW) != 0)
#endif /* !WITH_ACL */ #endif /* !WITH_ACL */
#ifdef WITH_ATTR #ifdef WITH_ATTR
/* /*
@ -681,10 +734,10 @@ static int copy_special (const char *src, const char *dst,
* additional logic so that no unexpected permissions result. * additional logic so that no unexpected permissions result.
*/ */
|| ( !reset_selinux || ( !reset_selinux
&& (attr_copy_file (src, dst, NULL, &ctx) != 0) && (attr_copy_path (src, dst, NULL, &ctx) != 0)
&& (errno != 0)) && (errno != 0))
#endif /* WITH_ATTR */ #endif /* WITH_ATTR */
|| (utimes (dst, mt) != 0)) { || (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0)) {
err = -1; err = -1;
} }
@ -737,9 +790,9 @@ static ssize_t full_write(int fd, const void *buf, size_t count) {
* *
* Return 0 on success, -1 on error. * Return 0 on success, -1 on error.
*/ */
static int copy_file (const char *src, const char *dst, static int copy_file (const struct path_info *src, const struct path_info *dst,
bool reset_selinux, bool reset_selinux,
const struct stat *statp, const struct timeval mt[], const struct stat *statp, const struct timespec mt[],
uid_t old_uid, uid_t new_uid, uid_t old_uid, uid_t new_uid,
gid_t old_gid, gid_t new_gid) gid_t old_gid, gid_t new_gid)
{ {
@ -747,22 +800,22 @@ static int copy_file (const char *src, const char *dst,
int ifd; int ifd;
int ofd; int ofd;
ifd = open (src, O_RDONLY|O_NOFOLLOW); ifd = openat (src->dirfd, src->name, O_RDONLY|O_NOFOLLOW|O_CLOEXEC);
if (ifd < 0) { if (ifd < 0) {
return -1; return -1;
} }
#ifdef WITH_SELINUX #ifdef WITH_SELINUX
if (set_selinux_file_context (dst, S_IFREG) != 0) { if (set_selinux_file_context (dst->full_path, S_IFREG) != 0) {
(void) close (ifd); (void) close (ifd);
return -1; return -1;
} }
#endif /* WITH_SELINUX */ #endif /* WITH_SELINUX */
ofd = open (dst, O_WRONLY | O_CREAT | O_EXCL | O_TRUNC | O_NOFOLLOW | O_CLOEXEC, statp->st_mode & 07777); 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) if ( (ofd < 0)
|| (fchown_if_needed (ofd, statp, || (fchown_if_needed (ofd, statp,
old_uid, new_uid, old_gid, new_gid) != 0) old_uid, new_uid, old_gid, new_gid) != 0)
#ifdef WITH_ACL #ifdef WITH_ACL
|| ( (perm_copy_fd (src, ifd, dst, ofd, &ctx) != 0) || ( (perm_copy_fd (src->full_path, ifd, dst->full_path, ofd, &ctx) != 0)
&& (errno != 0)) && (errno != 0))
#else /* !WITH_ACL */ #else /* !WITH_ACL */
|| (fchmod (ofd, statp->st_mode & 07777) != 0) || (fchmod (ofd, statp->st_mode & 07777) != 0)
@ -776,7 +829,7 @@ static int copy_file (const char *src, const char *dst,
* additional logic so that no unexpected permissions result. * additional logic so that no unexpected permissions result.
*/ */
|| ( !reset_selinux || ( !reset_selinux
&& (attr_copy_fd (src, ifd, dst, ofd, NULL, &ctx) != 0) && (attr_copy_fd (src->full_path, ifd, dst->full_path, ofd, NULL, &ctx) != 0)
&& (errno != 0)) && (errno != 0))
#endif /* WITH_ATTR */ #endif /* WITH_ATTR */
) { ) {
@ -812,23 +865,13 @@ static int copy_file (const char *src, const char *dst,
} }
(void) close (ifd); (void) close (ifd);
#ifdef HAVE_FUTIMES
if (futimes (ofd, mt) != 0) {
(void) close (ofd);
return -1;
}
#endif /* HAVE_FUTIMES */
if (close (ofd) != 0) { if (close (ofd) != 0) {
return -1; return -1;
} }
#ifndef HAVE_FUTIMES if (utimensat (dst->dirfd, dst->name, mt, AT_SYMLINK_NOFOLLOW) != 0) {
if (utimes(dst, mt) != 0) {
return -1; return -1;
} }
#endif /* !HAVE_FUTIMES */
return err; return err;
} }
@ -863,7 +906,70 @@ static int chown_function ## _if_needed (type_dst dst, \
return chown_function (dst, tmpuid, tmpgid); \ return chown_function (dst, tmpuid, tmpgid); \
} }
def_chown_if_needed (chown, const char *)
def_chown_if_needed (lchown, const char *)
def_chown_if_needed (fchown, int) 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);
}