Merge pull request #8125 from ThomasWaldmann/acl-error-handling-1.4

improve acl_get / acl_set error handling (1.4-maint)

src/borg/archive.py

@@ -902,7 +902,11 @@ Utilization of max. archive size: {csize_max:.0%}
                     if not symlink:
                         os.chmod(path, item.mode)
             if not self.noacls:
-                acl_set(path, item, self.numeric_ids, fd=fd)
+                try:
+                    acl_set(path, item, self.numeric_ids, fd=fd)
+                except OSError as e:
+                    if e.errno not in (errno.ENOTSUP, ):
+                        raise
             if not self.noxattrs:
                 # chown removes Linux capabilities, so set the extended attributes at the end, after chown, since they include
                 # the Linux capabilities in the "security.capability" attribute.
@@ -1165,7 +1169,11 @@ class MetadataCollector:
                 attrs['xattrs'] = StableDict(xattrs)
         if not self.noacls:
             with backup_io('extended stat (ACLs)'):
-                acl_get(path, attrs, st, self.numeric_ids, fd=fd)
+                try:
+                    acl_get(path, attrs, st, self.numeric_ids, fd=fd)
+                except OSError as e:
+                    if e.errno not in (errno.ENOTSUP, ):
+                        raise
         return attrs
 
     def stat_attrs(self, st, path, fd=None):

src/borg/platform/darwin.pyx

@@ -1,6 +1,7 @@
 import os
 
 from libc.stdint cimport uint32_t
+from libc cimport errno
 
 from .posix import user2uid, group2gid
 from ..helpers import safe_decode, safe_encode
@@ -121,10 +122,13 @@ def acl_get(path, item, st, numeric_ids=False, fd=None):
         else:
             acl = acl_get_link_np(path, ACL_TYPE_EXTENDED)
         if acl == NULL:
-            return
+            if errno.errno == errno.ENOENT:
+                # macOS weirdness: if a file has no ACLs, it sets errno to ENOENT. :-(
+                return
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         text = acl_to_text(acl, NULL)
         if text == NULL:
-            return
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         if numeric_ids:
             item['acl_extended'] = _remove_non_numeric_identifier(text)
         else:
@@ -139,17 +143,19 @@ def acl_set(path, item, numeric_ids=False, fd=None):
     acl_text = item.get('acl_extended')
     if acl_text is not None:
         try:
+            if isinstance(path, str):
+                path = os.fsencode(path)
             if numeric_ids:
                 acl = acl_from_text(acl_text)
             else:
                 acl = acl_from_text(<bytes>_remove_numeric_id_if_possible(acl_text))
             if acl == NULL:
-                return
-            if isinstance(path, str):
-                path = os.fsencode(path)
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
             if fd is not None:
-                acl_set_fd_np(fd, acl, ACL_TYPE_EXTENDED)
+                if acl_set_fd_np(fd, acl, ACL_TYPE_EXTENDED) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
             else:
-                acl_set_link_np(path, ACL_TYPE_EXTENDED, acl)
+                if acl_set_link_np(path, ACL_TYPE_EXTENDED, acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         finally:
             acl_free(acl)

src/borg/platform/freebsd.pyx

@@ -1,14 +1,13 @@
 import os
+import stat
 
 from .posix import posix_acl_use_stored_uid_gid
 from ..helpers import safe_encode, safe_decode
 from .xattr import _listxattr_inner, _getxattr_inner, _setxattr_inner, split_lstring
 
-API_VERSION = '1.4_01'
+from libc cimport errno
 
-cdef extern from "errno.h":
-    int errno
-    int EINVAL
+API_VERSION = '1.4_01'
 
 cdef extern from "sys/extattr.h":
     ssize_t c_extattr_list_file "extattr_list_file" (const char *path, int attrnamespace, void *data, size_t nbytes)
@@ -44,10 +43,12 @@ cdef extern from "sys/acl.h":
     char *acl_to_text_np(acl_t acl, ssize_t *len, int flags)
     int ACL_TEXT_NUMERIC_IDS
     int ACL_TEXT_APPEND_ID
+    int acl_extended_link_np(const char * path)  # check also: acl_is_trivial_np
 
 cdef extern from "unistd.h":
     long lpathconf(const char *path, int name)
     int _PC_ACL_NFS4
+    int _PC_ACL_EXTENDED
 
 
 # On FreeBSD, borg currently only deals with the USER namespace as it is unclear
@@ -130,13 +131,15 @@ cdef _get_acl(p, type, item, attribute, flags, fd=None):
         acl = acl_get_fd_np(fd, type)
     else:
         acl = acl_get_link_np(p, type)
-    if acl:
-        text = acl_to_text_np(acl, NULL, flags)
-        if text:
-            item[attribute] = text
-            acl_free(text)
+    if acl == NULL:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+    text = acl_to_text_np(acl, NULL, flags)
+    if text == NULL:
         acl_free(acl)
-
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+    item[attribute] = text
+    acl_free(text)
+    acl_free(acl)
 
 def acl_get(path, item, st, numeric_ids=False, fd=None):
     """Saves ACL Entries
@@ -144,33 +147,47 @@ def acl_get(path, item, st, numeric_ids=False, fd=None):
     If `numeric_ids` is True the user/group field is not preserved only uid/gid
     """
     cdef int flags = ACL_TEXT_APPEND_ID
+    flags |= ACL_TEXT_NUMERIC_IDS if numeric_ids else 0
     if isinstance(path, str):
         path = os.fsencode(path)
-    ret = lpathconf(path, _PC_ACL_NFS4)
-    if ret < 0 and errno == EINVAL:
+    ret = acl_extended_link_np(path)
+    if ret < 0:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+    if ret == 0:
+        # there is no ACL defining permissions other than those defined by the traditional file permission bits.
         return
-    flags |= ACL_TEXT_NUMERIC_IDS if numeric_ids else 0
-    if ret > 0:
+    ret = lpathconf(path, _PC_ACL_NFS4)
+    if ret < 0:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+    nfs4_acl = ret == 1
+    if nfs4_acl:
         _get_acl(path, ACL_TYPE_NFS4, item, 'acl_nfs4', flags, fd=fd)
     else:
         _get_acl(path, ACL_TYPE_ACCESS, item, 'acl_access', flags, fd=fd)
-        _get_acl(path, ACL_TYPE_DEFAULT, item, 'acl_default', flags, fd=fd)
+        if stat.S_ISDIR(st.st_mode):
+            _get_acl(path, ACL_TYPE_DEFAULT, item, 'acl_default', flags, fd=fd)
 
 
 cdef _set_acl(p, type, item, attribute, numeric_ids=False, fd=None):
     cdef acl_t acl
     text = item.get(attribute)
     if text:
-        if numeric_ids and type == ACL_TYPE_NFS4:
-            text = _nfs4_use_stored_uid_gid(text)
-        elif numeric_ids and type in(ACL_TYPE_ACCESS, ACL_TYPE_DEFAULT):
-            text = posix_acl_use_stored_uid_gid(text)
+        if numeric_ids:
+            if type == ACL_TYPE_NFS4:
+                text = _nfs4_use_stored_uid_gid(text)
+            elif type in (ACL_TYPE_ACCESS, ACL_TYPE_DEFAULT):
+                text = posix_acl_use_stored_uid_gid(text)
         acl = acl_from_text(<bytes>text)
-        if acl:
+        if acl == NULL:
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+        try:
             if fd is not None:
-                acl_set_fd_np(fd, acl, type)
+                if acl_set_fd_np(fd, acl, type) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
             else:
-                acl_set_link_np(p, type, acl)
+                if acl_set_link_np(p, type, acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+        finally:
             acl_free(acl)
 
 
@@ -196,6 +213,14 @@ def acl_set(path, item, numeric_ids=False, fd=None):
     """
     if isinstance(path, str):
         path = os.fsencode(path)
-    _set_acl(path, ACL_TYPE_NFS4, item, 'acl_nfs4', numeric_ids, fd=fd)
-    _set_acl(path, ACL_TYPE_ACCESS, item, 'acl_access', numeric_ids, fd=fd)
-    _set_acl(path, ACL_TYPE_DEFAULT, item, 'acl_default', numeric_ids, fd=fd)
+    ret = lpathconf(path, _PC_ACL_NFS4)
+    if ret < 0:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+    if ret == 1:
+        _set_acl(path, ACL_TYPE_NFS4, item, 'acl_nfs4', numeric_ids, fd=fd)
+    ret = lpathconf(path, _PC_ACL_EXTENDED)
+    if ret < 0:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+    if ret == 1:
+        _set_acl(path, ACL_TYPE_ACCESS, item, 'acl_access', numeric_ids, fd=fd)
+        _set_acl(path, ACL_TYPE_DEFAULT, item, 'acl_default', numeric_ids, fd=fd)

src/borg/platform/linux.pyx

@@ -52,7 +52,7 @@ cdef extern from "sys/acl.h":
     char *acl_to_text(acl_t acl, ssize_t *len)
 
 cdef extern from "acl/libacl.h":
-    int acl_extended_file(const char *path)
+    int acl_extended_file_nofollow(const char *path)
     int acl_extended_fd(int fd)
 
 cdef extern from "linux/fs.h":
@@ -232,15 +232,19 @@ def acl_get(path, item, st, numeric_ids=False, fd=None):
     cdef acl_t access_acl = NULL
     cdef char *default_text = NULL
     cdef char *access_text = NULL
+    cdef int ret = 0
 
-    if stat.S_ISLNK(st.st_mode):
-        # symlinks can not have ACLs
-        return
     if isinstance(path, str):
         path = os.fsencode(path)
-    if (fd is not None and acl_extended_fd(fd) <= 0
-        or
-        fd is None and acl_extended_file(path) <= 0):
+    if fd is not None:
+        ret = acl_extended_fd(fd)
+    else:
+        ret = acl_extended_file_nofollow(path)
+    if ret < 0:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+    if ret == 0:
+        # there is no ACL defining permissions other than those defined by the traditional file permission bits.
+        # note: this should also be the case for symlink fs objects, as they can not have ACLs.
         return
     if numeric_ids:
         converter = acl_numeric_ids
@@ -251,22 +255,28 @@ def acl_get(path, item, st, numeric_ids=False, fd=None):
             access_acl = acl_get_fd(fd)
         else:
             access_acl = acl_get_file(path, ACL_TYPE_ACCESS)
-        if stat.S_ISDIR(st.st_mode):
-            # only directories can have a default ACL. there is no fd-based api to get it.
-            default_acl = acl_get_file(path, ACL_TYPE_DEFAULT)
-        if access_acl:
-            access_text = acl_to_text(access_acl, NULL)
-            if access_text:
-                item['acl_access'] = converter(access_text)
-        if default_acl:
-            default_text = acl_to_text(default_acl, NULL)
-            if default_text:
-                item['acl_default'] = converter(default_text)
+        if access_acl == NULL:
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+        access_text = acl_to_text(access_acl, NULL)
+        if access_text == NULL:
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+        item['acl_access'] = converter(access_text)
     finally:
-        acl_free(default_text)
-        acl_free(default_acl)
         acl_free(access_text)
         acl_free(access_acl)
+    if stat.S_ISDIR(st.st_mode):
+        # only directories can have a default ACL. there is no fd-based api to get it.
+        try:
+            default_acl = acl_get_file(path, ACL_TYPE_DEFAULT)
+            if default_acl == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            default_text = acl_to_text(default_acl, NULL)
+            if default_text == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            item['acl_default'] = converter(default_text)
+        finally:
+            acl_free(default_text)
+            acl_free(default_acl)
 
 
 def acl_set(path, item, numeric_ids=False, fd=None):
@@ -277,7 +287,7 @@ def acl_set(path, item, numeric_ids=False, fd=None):
         # Linux does not support setting ACLs on symlinks
         return
 
-    if fd is None and isinstance(path, str):
+    if isinstance(path, str):
         path = os.fsencode(path)
     if numeric_ids:
         converter = posix_acl_use_stored_uid_gid
@@ -287,20 +297,25 @@ def acl_set(path, item, numeric_ids=False, fd=None):
     if access_text:
         try:
             access_acl = acl_from_text(<bytes>converter(access_text))
-            if access_acl:
-                if fd is not None:
-                    acl_set_fd(fd, access_acl)
-                else:
-                    acl_set_file(path, ACL_TYPE_ACCESS, access_acl)
+            if access_acl == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            if fd is not None:
+                if acl_set_fd(fd, access_acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            else:
+                if acl_set_file(path, ACL_TYPE_ACCESS, access_acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         finally:
             acl_free(access_acl)
     default_text = item.get('acl_default')
     if default_text:
         try:
             default_acl = acl_from_text(<bytes>converter(default_text))
-            if default_acl:
-                # only directories can get a default ACL. there is no fd-based api to set it.
-                acl_set_file(path, ACL_TYPE_DEFAULT, default_acl)
+            if default_acl == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            # only directories can get a default ACL. there is no fd-based api to set it.
+            if acl_set_file(path, ACL_TYPE_DEFAULT, default_acl) == -1:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         finally:
             acl_free(default_acl)
 

src/borg/testsuite/platform.py

@@ -1,6 +1,6 @@
+import errno
 import functools
 import os
-import random
 import shutil
 import sys
 import tempfile
@@ -13,31 +13,6 @@ from . import BaseTestCase, unopened_tempfile
 from .locking import free_pid
 
 
-ACCESS_ACL = """
-user::rw-
-user:root:rw-:0
-user:9999:r--:9999
-group::r--
-group:root:r--:0
-group:9999:r--:9999
-mask::rw-
-other::r--
-""".strip().encode('ascii')
-
-DEFAULT_ACL = """
-user::rw-
-user:root:r--:0
-user:8888:r--:8888
-group::r--
-group:root:r--:0
-group:8888:r--:8888
-mask::rw-
-other::r--
-""".strip().encode('ascii')
-
-_acls_working = None
-
-
 def fakeroot_detected():
     return 'FAKEROOTKEY' in os.environ
 
@@ -58,20 +33,42 @@ def are_acls_working():
     with unopened_tempfile() as filepath:
         open(filepath, 'w').close()
         try:
-            access = b'user::rw-\ngroup::r--\nmask::rw-\nother::---\nuser:root:rw-:9999\ngroup:root:rw-:9999\n'
-            acl = {'acl_access': access}
-            acl_set(filepath, acl)
+            if is_darwin:
+                acl_key = 'acl_extended'
+                acl_value = b'!#acl 1\nuser:FFFFEEEE-DDDD-CCCC-BBBB-AAAA00000000:root:0:allow:read\n'
+            elif is_linux:
+                acl_key = 'acl_access'
+                acl_value = b'user::rw-\ngroup::r--\nmask::rw-\nother::---\nuser:root:rw-:9999\ngroup:root:rw-:9999\n'
+            elif is_freebsd:
+                acl_key = 'acl_access'
+                acl_value = b'user::rw-\ngroup::r--\nmask::rw-\nother::---\nuser:root:rw-\ngroup:wheel:rw-\n'
+            else:
+                return False  # ACLs unsupported on this platform.
+            write_acl = {acl_key: acl_value}
+            acl_set(filepath, write_acl)
             read_acl = {}
             acl_get(filepath, read_acl, os.stat(filepath))
-            read_acl_access = read_acl.get('acl_access', None)
-            if read_acl_access and b'user::rw-' in read_acl_access:
-                return True
+            acl = read_acl.get(acl_key, None)
+            if acl is not None:
+                if is_darwin:
+                    check_for = b'root:0:allow:read'
+                elif is_linux:
+                    check_for = b'user::rw-'
+                elif is_freebsd:
+                    check_for = b'user::rw-'
+                else:
+                    return False  # ACLs unsupported on this platform.
+                if check_for in acl:
+                    return True
         except PermissionError:
             pass
+        except OSError as e:
+            if e.errno not in (errno.ENOTSUP, ):
+                raise
         return False
 
 
-@unittest.skipUnless(sys.platform.startswith('linux'), 'linux only test')
+@unittest.skipUnless(is_linux, 'linux only test')
 @unittest.skipIf(fakeroot_detected(), 'not compatible with fakeroot')
 class PlatformLinuxTestCase(BaseTestCase):
 
@@ -105,6 +102,8 @@ class PlatformLinuxTestCase(BaseTestCase):
 
     @unittest.skipIf(not are_acls_working(), 'ACLs do not work')
     def test_default_acl(self):
+        ACCESS_ACL = b'user::rw-\nuser:root:rw-:0\nuser:9999:r--:9999\ngroup::r--\ngroup:root:r--:0\ngroup:9999:r--:9999\nmask::rw-\nother::r--'
+        DEFAULT_ACL = b'user::rw-\nuser:root:r--:0\nuser:8888:r--:8888\ngroup::r--\ngroup:root:r--:0\ngroup:8888:r--:8888\nmask::rw-\nother::r--'
         self.assert_equal(self.get_acl(self.tmpdir), {})
         self.set_acl(self.tmpdir, access=ACCESS_ACL, default=DEFAULT_ACL)
         self.assert_equal(self.get_acl(self.tmpdir)['acl_access'], ACCESS_ACL)
@@ -149,7 +148,48 @@ class PlatformLinuxTestCase(BaseTestCase):
         self.assert_equal(acl_use_local_uid_gid(b'group:root:rw-:0'), b'group:0:rw-')
 
 
-@unittest.skipUnless(sys.platform.startswith('darwin'), 'macOS only test')
+@unittest.skipUnless(is_freebsd, 'freebsd only test')
+class PlatformFreeBSDTestCase(BaseTestCase):
+
+    def setUp(self):
+        self.tmpdir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        shutil.rmtree(self.tmpdir)
+
+    def get_acl(self, path, numeric_ids=False):
+        item = {}
+        acl_get(path, item, os.stat(path), numeric_ids=numeric_ids)
+        return item
+
+    def set_acl(self, path, access=None, default=None, numeric_ids=False):
+        item = {'acl_access': access, 'acl_default': default}
+        acl_set(path, item, numeric_ids=numeric_ids)
+
+    @unittest.skipIf(not are_acls_working(), 'ACLs do not work')
+    def test_access_acl(self):
+        file = tempfile.NamedTemporaryFile()
+        self.assert_equal(self.get_acl(file.name), {})
+        self.set_acl(file.name, access=b'user::rw-\ngroup::r--\nmask::rw-\nother::---\nuser:root:rw-\ngroup:wheel:rw-\n', numeric_ids=False)
+        self.assert_in(b'user:root:rw-', self.get_acl(file.name)['acl_access'])
+        self.assert_in(b'group:wheel:rw-', self.get_acl(file.name)['acl_access'])
+        self.assert_in(b'user:0:rw-', self.get_acl(file.name, numeric_ids=True)['acl_access'])
+        file2 = tempfile.NamedTemporaryFile()
+        self.set_acl(file2.name, access=b'user::rw-\ngroup::r--\nmask::rw-\nother::---\nuser:root:rw-\ngroup:wheel:rw-\n', numeric_ids=True)
+        self.assert_in(b'user::rw-', self.get_acl(file2.name)['acl_access'])
+        self.assert_in(b'group::r--', self.get_acl(file2.name)['acl_access'])
+
+    @unittest.skipIf(not are_acls_working(), 'ACLs do not work')
+    def test_default_acl(self):
+        ACCESS_ACL = b'user::rw-\nuser:root:rw-\nuser:9999:r--\ngroup::r--\ngroup:wheel:r--\ngroup:9999:r--\nmask::rw-\nother::r--\n'
+        DEFAULT_ACL = b'user::rw-\nuser:root:r--\nuser:8888:r--\ngroup::r--\ngroup:wheel:r--\ngroup:8888:r--\nmask::rw-\nother::r--\n'
+        self.assert_equal(self.get_acl(self.tmpdir), {})
+        self.set_acl(self.tmpdir, access=ACCESS_ACL, default=DEFAULT_ACL)
+        self.assert_equal(self.get_acl(self.tmpdir)['acl_access'], ACCESS_ACL)
+        self.assert_equal(self.get_acl(self.tmpdir)['acl_default'], DEFAULT_ACL)
+
+
+@unittest.skipUnless(is_darwin, 'macOS only test')
 @unittest.skipIf(fakeroot_detected(), 'not compatible with fakeroot')
 class PlatformDarwinTestCase(BaseTestCase):
 
@@ -169,7 +209,7 @@ class PlatformDarwinTestCase(BaseTestCase):
         acl_set(path, item, numeric_ids=numeric_ids)
 
     @unittest.skipIf(not are_acls_working(), 'ACLs do not work')
-    def test_access_acl(self):
+    def test_extended_acl(self):
         file = tempfile.NamedTemporaryFile()
         file2 = tempfile.NamedTemporaryFile()
         self.assert_equal(self.get_acl(file.name), {})