2 Unix SMB/Netbios implementation.
3 VFS module to get and set posix acls through xattr
4 Copyright (c) 2013 Anand Avati <avati@redhat.com>
5 Copyright (c) 2016 Yan, Zheng <zyan@redhat.com>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include "system/filesys.h"
23 #include "smbd/smbd.h"
24 #include "modules/posixacl_xattr.h"
29 Size = 4 (header) + N * 8 (entry)
31 Offset Size Field (Little Endian)
32 -------------------------------------
35 4-5 2-byte Entry-1 tag
36 6-7 2-byte Entry-1 perm
37 8-11 4-byte Entry-1 id
39 12-13 2-byte Entry-2 tag
40 14-15 2-byte Entry-2 perm
41 16-19 4-byte Entry-2 id
49 /* private functions */
51 #define ACL_EA_ACCESS "system.posix_acl_access"
52 #define ACL_EA_DEFAULT "system.posix_acl_default"
53 #define ACL_EA_VERSION 0x0002
54 #define ACL_EA_HEADER_SIZE 4
55 #define ACL_EA_ENTRY_SIZE 8
57 #define ACL_EA_SIZE(n) (ACL_EA_HEADER_SIZE + ((n) * ACL_EA_ENTRY_SIZE))
59 static SMB_ACL_T mode_to_smb_acl(mode_t mode, TALLOC_CTX *mem_ctx)
61 struct smb_acl_t *result;
65 result = sys_acl_init(mem_ctx);
70 result->acl = talloc_array(result, struct smb_acl_entry, count);
77 result->count = count;
79 result->acl[0].a_type = SMB_ACL_USER_OBJ;
80 result->acl[0].a_perm = (mode & S_IRWXU) >> 6;
82 result->acl[1].a_type = SMB_ACL_GROUP_OBJ;
83 result->acl[1].a_perm = (mode & S_IRWXG) >> 3;
85 result->acl[2].a_type = SMB_ACL_OTHER;
86 result->acl[2].a_perm = mode & S_IRWXO;
91 static SMB_ACL_T posixacl_xattr_to_smb_acl(const char *buf, size_t xattr_size,
96 struct smb_acl_entry *smb_ace;
97 struct smb_acl_t *result;
106 if (size < ACL_EA_HEADER_SIZE) {
107 /* ACL should be at least as big as the header (4 bytes) */
112 /* Version is the first 4 bytes of the ACL */
113 if (IVAL(buf, 0) != ACL_EA_VERSION) {
114 DEBUG(0, ("Unknown ACL EA version: %d\n",
119 offset = ACL_EA_HEADER_SIZE;
121 size -= ACL_EA_HEADER_SIZE;
122 if (size % ACL_EA_ENTRY_SIZE) {
123 /* Size of entries must strictly be a multiple of
124 size of an ACE (8 bytes)
126 DEBUG(0, ("Invalid ACL EA size: %d\n", size));
131 count = size / ACL_EA_ENTRY_SIZE;
133 result = sys_acl_init(mem_ctx);
138 result->acl = talloc_array(result, struct smb_acl_entry, count);
145 result->count = count;
147 smb_ace = result->acl;
149 for (i = 0; i < count; i++) {
150 /* TAG is the first 2 bytes of an entry */
151 tag = SVAL(buf, offset);
154 /* PERM is the next 2 bytes of an entry */
155 perm = SVAL(buf, offset);
158 /* ID is the last 4 bytes of an entry */
159 id = IVAL(buf, offset);
164 smb_ace->a_type = SMB_ACL_USER;
167 smb_ace->a_type = SMB_ACL_USER_OBJ;
170 smb_ace->a_type = SMB_ACL_GROUP;
173 smb_ace->a_type = SMB_ACL_GROUP_OBJ;
176 smb_ace->a_type = SMB_ACL_OTHER;
179 smb_ace->a_type = SMB_ACL_MASK;
182 DEBUG(0, ("unknown tag type %d\n", (unsigned int) tag));
188 switch(smb_ace->a_type) {
190 smb_ace->info.user.uid = id;
193 smb_ace->info.group.gid = id;
200 smb_ace->a_perm |= ((perm & ACL_READ) ? SMB_ACL_READ : 0);
201 smb_ace->a_perm |= ((perm & ACL_WRITE) ? SMB_ACL_WRITE : 0);
202 smb_ace->a_perm |= ((perm & ACL_EXECUTE) ? SMB_ACL_EXECUTE : 0);
211 static int posixacl_xattr_entry_compare(const void *left, const void *right)
214 uint16_t tag_left, tag_right;
215 uint32_t id_left, id_right;
219 - Smaller TAG values must be earlier.
220 - Within same TAG, smaller identifiers must be earlier, E.g:
221 UID 0 entry must be earlier than UID 200
222 GID 17 entry must be earlier than GID 19
225 /* TAG is the first element in the entry */
226 tag_left = SVAL(left, 0);
227 tag_right = SVAL(right, 0);
229 ret = NUMERIC_CMP(tag_left, tag_right);
231 /* ID is the third element in the entry, after two short
232 integers (tag and perm), i.e at offset 4.
234 id_left = IVAL(left, 4);
235 id_right = IVAL(right, 4);
236 ret = NUMERIC_CMP(id_left, id_right);
243 static int smb_acl_to_posixacl_xattr(SMB_ACL_T theacl, char *buf, size_t len)
246 struct smb_acl_entry *smb_ace;
254 count = theacl->count;
256 size = ACL_EA_SIZE(count);
263 smb_ace = theacl->acl;
265 /* Version is the first 4 bytes of the ACL */
266 SIVAL(buf, 0, ACL_EA_VERSION);
267 offset = ACL_EA_HEADER_SIZE;
269 for (i = 0; i < count; i++) {
271 switch(smb_ace->a_type) {
275 case SMB_ACL_USER_OBJ:
281 case SMB_ACL_GROUP_OBJ:
291 DEBUG(0, ("Unknown tag value %d\n",
298 switch(smb_ace->a_type) {
300 id = smb_ace->info.user.uid;
303 id = smb_ace->info.group.gid;
306 id = ACL_UNDEFINED_ID;
312 perm |= (smb_ace->a_perm & SMB_ACL_READ) ? ACL_READ : 0;
313 perm |= (smb_ace->a_perm & SMB_ACL_WRITE) ? ACL_WRITE : 0;
314 perm |= (smb_ace->a_perm & SMB_ACL_EXECUTE) ? ACL_EXECUTE : 0;
316 /* TAG is the first 2 bytes of an entry */
317 SSVAL(buf, offset, tag);
320 /* PERM is the next 2 bytes of an entry */
321 SSVAL(buf, offset, perm);
324 /* ID is the last 4 bytes of an entry */
325 SIVAL(buf, offset, id);
331 /* Skip the header, sort @count number of 8-byte entries */
332 qsort(buf+ACL_EA_HEADER_SIZE, count, ACL_EA_ENTRY_SIZE,
333 posixacl_xattr_entry_compare);
338 SMB_ACL_T posixacl_xattr_acl_get_fd(vfs_handle_struct *handle,
344 int size = ACL_EA_SIZE(20);
345 char *buf = alloca(size);
348 if (type == SMB_ACL_TYPE_ACCESS) {
349 name = ACL_EA_ACCESS;
350 } else if (type == SMB_ACL_TYPE_DEFAULT) {
351 name = ACL_EA_DEFAULT;
361 ret = SMB_VFS_FGETXATTR(fsp, name, buf, size);
362 if (ret < 0 && errno == ERANGE) {
363 size = SMB_VFS_FGETXATTR(fsp, name, NULL, 0);
369 ret = SMB_VFS_FGETXATTR(fsp, name, buf, size);
374 return posixacl_xattr_to_smb_acl(buf, ret, mem_ctx);
376 if (ret == 0 || errno == ENOATTR) {
377 SMB_STRUCT_STAT sbuf;
378 ret = SMB_VFS_FSTAT(fsp, &sbuf);
380 return mode_to_smb_acl(sbuf.st_ex_mode, mem_ctx);
385 int posixacl_xattr_acl_set_fd(vfs_handle_struct *handle,
390 const char *name = NULL;
395 if (type == SMB_ACL_TYPE_ACCESS) {
396 name = ACL_EA_ACCESS;
397 } else if (type == SMB_ACL_TYPE_DEFAULT) {
398 name = ACL_EA_DEFAULT;
404 size = smb_acl_to_posixacl_xattr(theacl, NULL, 0);
410 ret = smb_acl_to_posixacl_xattr(theacl, buf, size);
416 return SMB_VFS_FSETXATTR(fsp, name, buf, size, 0);
419 int posixacl_xattr_acl_delete_def_fd(vfs_handle_struct *handle,
422 return SMB_VFS_FREMOVEXATTR(fsp, ACL_EA_DEFAULT);