1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2021 Samsung Electronics Co., Ltd.
4  *   Author(s): Namjae Jeon <linkinjeon@kernel.org>
5  */
6 
7 #include <linux/fs.h>
8 
9 #include "glob.h"
10 #include "ndr.h"
11 
ndr_get_field(struct ndr * n)12 static inline char *ndr_get_field(struct ndr *n)
13 {
14 	return n->data + n->offset;
15 }
16 
try_to_realloc_ndr_blob(struct ndr * n,size_t sz)17 static int try_to_realloc_ndr_blob(struct ndr *n, size_t sz)
18 {
19 	char *data;
20 
21 	data = krealloc(n->data, n->offset + sz + 1024, GFP_KERNEL);
22 	if (!data)
23 		return -ENOMEM;
24 
25 	n->data = data;
26 	n->length += 1024;
27 	memset(n->data + n->offset, 0, 1024);
28 	return 0;
29 }
30 
ndr_write_int16(struct ndr * n,__u16 value)31 static int ndr_write_int16(struct ndr *n, __u16 value)
32 {
33 	if (n->length <= n->offset + sizeof(value)) {
34 		int ret;
35 
36 		ret = try_to_realloc_ndr_blob(n, sizeof(value));
37 		if (ret)
38 			return ret;
39 	}
40 
41 	*(__le16 *)ndr_get_field(n) = cpu_to_le16(value);
42 	n->offset += sizeof(value);
43 	return 0;
44 }
45 
ndr_write_int32(struct ndr * n,__u32 value)46 static int ndr_write_int32(struct ndr *n, __u32 value)
47 {
48 	if (n->length <= n->offset + sizeof(value)) {
49 		int ret;
50 
51 		ret = try_to_realloc_ndr_blob(n, sizeof(value));
52 		if (ret)
53 			return ret;
54 	}
55 
56 	*(__le32 *)ndr_get_field(n) = cpu_to_le32(value);
57 	n->offset += sizeof(value);
58 	return 0;
59 }
60 
ndr_write_int64(struct ndr * n,__u64 value)61 static int ndr_write_int64(struct ndr *n, __u64 value)
62 {
63 	if (n->length <= n->offset + sizeof(value)) {
64 		int ret;
65 
66 		ret = try_to_realloc_ndr_blob(n, sizeof(value));
67 		if (ret)
68 			return ret;
69 	}
70 
71 	*(__le64 *)ndr_get_field(n) = cpu_to_le64(value);
72 	n->offset += sizeof(value);
73 	return 0;
74 }
75 
ndr_write_bytes(struct ndr * n,void * value,size_t sz)76 static int ndr_write_bytes(struct ndr *n, void *value, size_t sz)
77 {
78 	if (n->length <= n->offset + sz) {
79 		int ret;
80 
81 		ret = try_to_realloc_ndr_blob(n, sz);
82 		if (ret)
83 			return ret;
84 	}
85 
86 	memcpy(ndr_get_field(n), value, sz);
87 	n->offset += sz;
88 	return 0;
89 }
90 
ndr_write_string(struct ndr * n,char * value)91 static int ndr_write_string(struct ndr *n, char *value)
92 {
93 	size_t sz;
94 
95 	sz = strlen(value) + 1;
96 	if (n->length <= n->offset + sz) {
97 		int ret;
98 
99 		ret = try_to_realloc_ndr_blob(n, sz);
100 		if (ret)
101 			return ret;
102 	}
103 
104 	memcpy(ndr_get_field(n), value, sz);
105 	n->offset += sz;
106 	n->offset = ALIGN(n->offset, 2);
107 	return 0;
108 }
109 
ndr_read_string(struct ndr * n,void * value,size_t sz)110 static int ndr_read_string(struct ndr *n, void *value, size_t sz)
111 {
112 	int len;
113 
114 	if (n->offset + sz > n->length)
115 		return -EINVAL;
116 
117 	len = strnlen(ndr_get_field(n), sz);
118 	if (value)
119 		memcpy(value, ndr_get_field(n), len);
120 	len++;
121 	n->offset += len;
122 	n->offset = ALIGN(n->offset, 2);
123 	return 0;
124 }
125 
ndr_read_bytes(struct ndr * n,void * value,size_t sz)126 static int ndr_read_bytes(struct ndr *n, void *value, size_t sz)
127 {
128 	if (n->offset + sz > n->length)
129 		return -EINVAL;
130 
131 	if (value)
132 		memcpy(value, ndr_get_field(n), sz);
133 	n->offset += sz;
134 	return 0;
135 }
136 
ndr_read_int16(struct ndr * n,__u16 * value)137 static int ndr_read_int16(struct ndr *n, __u16 *value)
138 {
139 	if (n->offset + sizeof(__u16) > n->length)
140 		return -EINVAL;
141 
142 	if (value)
143 		*value = le16_to_cpu(*(__le16 *)ndr_get_field(n));
144 	n->offset += sizeof(__u16);
145 	return 0;
146 }
147 
ndr_read_int32(struct ndr * n,__u32 * value)148 static int ndr_read_int32(struct ndr *n, __u32 *value)
149 {
150 	if (n->offset + sizeof(__u32) > n->length)
151 		return -EINVAL;
152 
153 	if (value)
154 		*value = le32_to_cpu(*(__le32 *)ndr_get_field(n));
155 	n->offset += sizeof(__u32);
156 	return 0;
157 }
158 
ndr_read_int64(struct ndr * n,__u64 * value)159 static int ndr_read_int64(struct ndr *n, __u64 *value)
160 {
161 	if (n->offset + sizeof(__u64) > n->length)
162 		return -EINVAL;
163 
164 	if (value)
165 		*value = le64_to_cpu(*(__le64 *)ndr_get_field(n));
166 	n->offset += sizeof(__u64);
167 	return 0;
168 }
169 
ndr_encode_dos_attr(struct ndr * n,struct xattr_dos_attrib * da)170 int ndr_encode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
171 {
172 	char hex_attr[12] = {0};
173 	int ret;
174 
175 	n->offset = 0;
176 	n->length = 1024;
177 	n->data = kzalloc(n->length, GFP_KERNEL);
178 	if (!n->data)
179 		return -ENOMEM;
180 
181 	if (da->version == 3) {
182 		snprintf(hex_attr, 10, "0x%x", da->attr);
183 		ret = ndr_write_string(n, hex_attr);
184 	} else {
185 		ret = ndr_write_string(n, "");
186 	}
187 	if (ret)
188 		return ret;
189 
190 	ret = ndr_write_int16(n, da->version);
191 	if (ret)
192 		return ret;
193 
194 	ret = ndr_write_int32(n, da->version);
195 	if (ret)
196 		return ret;
197 
198 	ret = ndr_write_int32(n, da->flags);
199 	if (ret)
200 		return ret;
201 
202 	ret = ndr_write_int32(n, da->attr);
203 	if (ret)
204 		return ret;
205 
206 	if (da->version == 3) {
207 		ret = ndr_write_int32(n, da->ea_size);
208 		if (ret)
209 			return ret;
210 		ret = ndr_write_int64(n, da->size);
211 		if (ret)
212 			return ret;
213 		ret = ndr_write_int64(n, da->alloc_size);
214 	} else {
215 		ret = ndr_write_int64(n, da->itime);
216 	}
217 	if (ret)
218 		return ret;
219 
220 	ret = ndr_write_int64(n, da->create_time);
221 	if (ret)
222 		return ret;
223 
224 	if (da->version == 3)
225 		ret = ndr_write_int64(n, da->change_time);
226 	return ret;
227 }
228 
ndr_decode_dos_attr(struct ndr * n,struct xattr_dos_attrib * da)229 int ndr_decode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
230 {
231 	char hex_attr[12];
232 	unsigned int version2;
233 	int ret;
234 
235 	n->offset = 0;
236 	ret = ndr_read_string(n, hex_attr, sizeof(hex_attr));
237 	if (ret)
238 		return ret;
239 
240 	ret = ndr_read_int16(n, &da->version);
241 	if (ret)
242 		return ret;
243 
244 	if (da->version != 3 && da->version != 4) {
245 		ksmbd_debug(VFS, "v%d version is not supported\n", da->version);
246 		return -EINVAL;
247 	}
248 
249 	ret = ndr_read_int32(n, &version2);
250 	if (ret)
251 		return ret;
252 
253 	if (da->version != version2) {
254 		ksmbd_debug(VFS, "ndr version mismatched(version: %d, version2: %d)\n",
255 		       da->version, version2);
256 		return -EINVAL;
257 	}
258 
259 	ret = ndr_read_int32(n, NULL);
260 	if (ret)
261 		return ret;
262 
263 	ret = ndr_read_int32(n, &da->attr);
264 	if (ret)
265 		return ret;
266 
267 	if (da->version == 4) {
268 		ret = ndr_read_int64(n, &da->itime);
269 		if (ret)
270 			return ret;
271 
272 		ret = ndr_read_int64(n, &da->create_time);
273 	} else {
274 		ret = ndr_read_int32(n, NULL);
275 		if (ret)
276 			return ret;
277 
278 		ret = ndr_read_int64(n, NULL);
279 		if (ret)
280 			return ret;
281 
282 		ret = ndr_read_int64(n, NULL);
283 		if (ret)
284 			return ret;
285 
286 		ret = ndr_read_int64(n, &da->create_time);
287 		if (ret)
288 			return ret;
289 
290 		ret = ndr_read_int64(n, NULL);
291 	}
292 
293 	return ret;
294 }
295 
ndr_encode_posix_acl_entry(struct ndr * n,struct xattr_smb_acl * acl)296 static int ndr_encode_posix_acl_entry(struct ndr *n, struct xattr_smb_acl *acl)
297 {
298 	int i, ret;
299 
300 	ret = ndr_write_int32(n, acl->count);
301 	if (ret)
302 		return ret;
303 
304 	n->offset = ALIGN(n->offset, 8);
305 	ret = ndr_write_int32(n, acl->count);
306 	if (ret)
307 		return ret;
308 
309 	ret = ndr_write_int32(n, 0);
310 	if (ret)
311 		return ret;
312 
313 	for (i = 0; i < acl->count; i++) {
314 		n->offset = ALIGN(n->offset, 8);
315 		ret = ndr_write_int16(n, acl->entries[i].type);
316 		if (ret)
317 			return ret;
318 
319 		ret = ndr_write_int16(n, acl->entries[i].type);
320 		if (ret)
321 			return ret;
322 
323 		if (acl->entries[i].type == SMB_ACL_USER) {
324 			n->offset = ALIGN(n->offset, 8);
325 			ret = ndr_write_int64(n, acl->entries[i].uid);
326 		} else if (acl->entries[i].type == SMB_ACL_GROUP) {
327 			n->offset = ALIGN(n->offset, 8);
328 			ret = ndr_write_int64(n, acl->entries[i].gid);
329 		}
330 		if (ret)
331 			return ret;
332 
333 		/* push permission */
334 		ret = ndr_write_int32(n, acl->entries[i].perm);
335 	}
336 
337 	return ret;
338 }
339 
ndr_encode_posix_acl(struct ndr * n,struct user_namespace * user_ns,struct inode * inode,struct xattr_smb_acl * acl,struct xattr_smb_acl * def_acl)340 int ndr_encode_posix_acl(struct ndr *n,
341 			 struct user_namespace *user_ns,
342 			 struct inode *inode,
343 			 struct xattr_smb_acl *acl,
344 			 struct xattr_smb_acl *def_acl)
345 {
346 	unsigned int ref_id = 0x00020000;
347 	int ret;
348 	vfsuid_t vfsuid;
349 	vfsgid_t vfsgid;
350 
351 	n->offset = 0;
352 	n->length = 1024;
353 	n->data = kzalloc(n->length, GFP_KERNEL);
354 	if (!n->data)
355 		return -ENOMEM;
356 
357 	if (acl) {
358 		/* ACL ACCESS */
359 		ret = ndr_write_int32(n, ref_id);
360 		ref_id += 4;
361 	} else {
362 		ret = ndr_write_int32(n, 0);
363 	}
364 	if (ret)
365 		return ret;
366 
367 	if (def_acl) {
368 		/* DEFAULT ACL ACCESS */
369 		ret = ndr_write_int32(n, ref_id);
370 		ref_id += 4;
371 	} else {
372 		ret = ndr_write_int32(n, 0);
373 	}
374 	if (ret)
375 		return ret;
376 
377 	vfsuid = i_uid_into_vfsuid(user_ns, inode);
378 	ret = ndr_write_int64(n, from_kuid(&init_user_ns, vfsuid_into_kuid(vfsuid)));
379 	if (ret)
380 		return ret;
381 	vfsgid = i_gid_into_vfsgid(user_ns, inode);
382 	ret = ndr_write_int64(n, from_kgid(&init_user_ns, vfsgid_into_kgid(vfsgid)));
383 	if (ret)
384 		return ret;
385 	ret = ndr_write_int32(n, inode->i_mode);
386 	if (ret)
387 		return ret;
388 
389 	if (acl) {
390 		ret = ndr_encode_posix_acl_entry(n, acl);
391 		if (def_acl && !ret)
392 			ret = ndr_encode_posix_acl_entry(n, def_acl);
393 	}
394 	return ret;
395 }
396 
ndr_encode_v4_ntacl(struct ndr * n,struct xattr_ntacl * acl)397 int ndr_encode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
398 {
399 	unsigned int ref_id = 0x00020004;
400 	int ret;
401 
402 	n->offset = 0;
403 	n->length = 2048;
404 	n->data = kzalloc(n->length, GFP_KERNEL);
405 	if (!n->data)
406 		return -ENOMEM;
407 
408 	ret = ndr_write_int16(n, acl->version);
409 	if (ret)
410 		return ret;
411 
412 	ret = ndr_write_int32(n, acl->version);
413 	if (ret)
414 		return ret;
415 
416 	ret = ndr_write_int16(n, 2);
417 	if (ret)
418 		return ret;
419 
420 	ret = ndr_write_int32(n, ref_id);
421 	if (ret)
422 		return ret;
423 
424 	/* push hash type and hash 64bytes */
425 	ret = ndr_write_int16(n, acl->hash_type);
426 	if (ret)
427 		return ret;
428 
429 	ret = ndr_write_bytes(n, acl->hash, XATTR_SD_HASH_SIZE);
430 	if (ret)
431 		return ret;
432 
433 	ret = ndr_write_bytes(n, acl->desc, acl->desc_len);
434 	if (ret)
435 		return ret;
436 
437 	ret = ndr_write_int64(n, acl->current_time);
438 	if (ret)
439 		return ret;
440 
441 	ret = ndr_write_bytes(n, acl->posix_acl_hash, XATTR_SD_HASH_SIZE);
442 	if (ret)
443 		return ret;
444 
445 	/* push ndr for security descriptor */
446 	ret = ndr_write_bytes(n, acl->sd_buf, acl->sd_size);
447 	return ret;
448 }
449 
ndr_decode_v4_ntacl(struct ndr * n,struct xattr_ntacl * acl)450 int ndr_decode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
451 {
452 	unsigned int version2;
453 	int ret;
454 
455 	n->offset = 0;
456 	ret = ndr_read_int16(n, &acl->version);
457 	if (ret)
458 		return ret;
459 	if (acl->version != 4) {
460 		ksmbd_debug(VFS, "v%d version is not supported\n", acl->version);
461 		return -EINVAL;
462 	}
463 
464 	ret = ndr_read_int32(n, &version2);
465 	if (ret)
466 		return ret;
467 	if (acl->version != version2) {
468 		ksmbd_debug(VFS, "ndr version mismatched(version: %d, version2: %d)\n",
469 		       acl->version, version2);
470 		return -EINVAL;
471 	}
472 
473 	/* Read Level */
474 	ret = ndr_read_int16(n, NULL);
475 	if (ret)
476 		return ret;
477 
478 	/* Read Ref Id */
479 	ret = ndr_read_int32(n, NULL);
480 	if (ret)
481 		return ret;
482 
483 	ret = ndr_read_int16(n, &acl->hash_type);
484 	if (ret)
485 		return ret;
486 
487 	ret = ndr_read_bytes(n, acl->hash, XATTR_SD_HASH_SIZE);
488 	if (ret)
489 		return ret;
490 
491 	ndr_read_bytes(n, acl->desc, 10);
492 	if (strncmp(acl->desc, "posix_acl", 9)) {
493 		pr_err("Invalid acl description : %s\n", acl->desc);
494 		return -EINVAL;
495 	}
496 
497 	/* Read Time */
498 	ret = ndr_read_int64(n, NULL);
499 	if (ret)
500 		return ret;
501 
502 	/* Read Posix ACL hash */
503 	ret = ndr_read_bytes(n, acl->posix_acl_hash, XATTR_SD_HASH_SIZE);
504 	if (ret)
505 		return ret;
506 
507 	acl->sd_size = n->length - n->offset;
508 	acl->sd_buf = kzalloc(acl->sd_size, GFP_KERNEL);
509 	if (!acl->sd_buf)
510 		return -ENOMEM;
511 
512 	ret = ndr_read_bytes(n, acl->sd_buf, acl->sd_size);
513 	return ret;
514 }
515