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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Implementation of the extensible bitmap type.
4 *
5 * Author : Stephen Smalley, <sds@tycho.nsa.gov>
6 */
7/*
8 * Updated: Hewlett-Packard <paul@paul-moore.com>
9 *
10 * Added support to import/export the NetLabel category bitmap
11 *
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
13 */
14/*
15 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
16 * Applied standard bit operations to improve bitmap scanning.
17 */
18
19#include <linux/kernel.h>
20#include <linux/slab.h>
21#include <linux/errno.h>
22#include <linux/jhash.h>
23#include <net/netlabel.h>
24#include "ebitmap.h"
25#include "policydb.h"
26
27#define BITS_PER_U64 (sizeof(u64) * 8)
28
29static struct kmem_cache *ebitmap_node_cachep __ro_after_init;
30
31int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2)
32{
33 const struct ebitmap_node *n1, *n2;
34
35 if (e1->highbit != e2->highbit)
36 return 0;
37
38 n1 = e1->node;
39 n2 = e2->node;
40 while (n1 && n2 &&
41 (n1->startbit == n2->startbit) &&
42 !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
43 n1 = n1->next;
44 n2 = n2->next;
45 }
46
47 if (n1 || n2)
48 return 0;
49
50 return 1;
51}
52
53int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src)
54{
55 struct ebitmap_node *new, *prev;
56 const struct ebitmap_node *n;
57
58 ebitmap_init(dst);
59 n = src->node;
60 prev = NULL;
61 while (n) {
62 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
63 if (!new) {
64 ebitmap_destroy(dst);
65 return -ENOMEM;
66 }
67 new->startbit = n->startbit;
68 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
69 new->next = NULL;
70 if (prev)
71 prev->next = new;
72 else
73 dst->node = new;
74 prev = new;
75 n = n->next;
76 }
77
78 dst->highbit = src->highbit;
79 return 0;
80}
81
82int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2)
83{
84 struct ebitmap_node *n;
85 int bit, rc;
86
87 ebitmap_init(dst);
88
89 ebitmap_for_each_positive_bit(e1, n, bit) {
90 if (ebitmap_get_bit(e2, bit)) {
91 rc = ebitmap_set_bit(dst, bit, 1);
92 if (rc < 0)
93 return rc;
94 }
95 }
96 return 0;
97}
98
99
100#ifdef CONFIG_NETLABEL
101/**
102 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
103 * @ebmap: the ebitmap to export
104 * @catmap: the NetLabel category bitmap
105 *
106 * Description:
107 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
108 * Returns zero on success, negative values on error.
109 *
110 */
111int ebitmap_netlbl_export(struct ebitmap *ebmap,
112 struct netlbl_lsm_catmap **catmap)
113{
114 struct ebitmap_node *e_iter = ebmap->node;
115 unsigned long e_map;
116 u32 offset;
117 unsigned int iter;
118 int rc;
119
120 if (e_iter == NULL) {
121 *catmap = NULL;
122 return 0;
123 }
124
125 if (*catmap != NULL)
126 netlbl_catmap_free(*catmap);
127 *catmap = NULL;
128
129 while (e_iter) {
130 offset = e_iter->startbit;
131 for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
132 e_map = e_iter->maps[iter];
133 if (e_map != 0) {
134 rc = netlbl_catmap_setlong(catmap,
135 offset,
136 e_map,
137 GFP_ATOMIC);
138 if (rc != 0)
139 goto netlbl_export_failure;
140 }
141 offset += EBITMAP_UNIT_SIZE;
142 }
143 e_iter = e_iter->next;
144 }
145
146 return 0;
147
148netlbl_export_failure:
149 netlbl_catmap_free(*catmap);
150 return -ENOMEM;
151}
152
153/**
154 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
155 * @ebmap: the ebitmap to import
156 * @catmap: the NetLabel category bitmap
157 *
158 * Description:
159 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
160 * Returns zero on success, negative values on error.
161 *
162 */
163int ebitmap_netlbl_import(struct ebitmap *ebmap,
164 struct netlbl_lsm_catmap *catmap)
165{
166 int rc;
167 struct ebitmap_node *e_iter = NULL;
168 struct ebitmap_node *e_prev = NULL;
169 u32 offset = 0, idx;
170 unsigned long bitmap;
171
172 for (;;) {
173 rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
174 if (rc < 0)
175 goto netlbl_import_failure;
176 if (offset == (u32)-1)
177 return 0;
178
179 /* don't waste ebitmap space if the netlabel bitmap is empty */
180 if (bitmap == 0) {
181 offset += EBITMAP_UNIT_SIZE;
182 continue;
183 }
184
185 if (e_iter == NULL ||
186 offset >= e_iter->startbit + EBITMAP_SIZE) {
187 e_prev = e_iter;
188 e_iter = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
189 if (e_iter == NULL)
190 goto netlbl_import_failure;
191 e_iter->startbit = offset - (offset % EBITMAP_SIZE);
192 if (e_prev == NULL)
193 ebmap->node = e_iter;
194 else
195 e_prev->next = e_iter;
196 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
197 }
198
199 /* offset will always be aligned to an unsigned long */
200 idx = EBITMAP_NODE_INDEX(e_iter, offset);
201 e_iter->maps[idx] = bitmap;
202
203 /* next */
204 offset += EBITMAP_UNIT_SIZE;
205 }
206
207 /* NOTE: we should never reach this return */
208 return 0;
209
210netlbl_import_failure:
211 ebitmap_destroy(ebmap);
212 return -ENOMEM;
213}
214#endif /* CONFIG_NETLABEL */
215
216/*
217 * Check to see if all the bits set in e2 are also set in e1. Optionally,
218 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
219 * last_e2bit.
220 */
221int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit)
222{
223 const struct ebitmap_node *n1, *n2;
224 int i;
225
226 if (e1->highbit < e2->highbit)
227 return 0;
228
229 n1 = e1->node;
230 n2 = e2->node;
231
232 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
233 if (n1->startbit < n2->startbit) {
234 n1 = n1->next;
235 continue;
236 }
237 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
238 i--; /* Skip trailing NULL map entries */
239 if (last_e2bit && (i >= 0)) {
240 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
241 __fls(n2->maps[i]);
242 if (lastsetbit > last_e2bit)
243 return 0;
244 }
245
246 while (i >= 0) {
247 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
248 return 0;
249 i--;
250 }
251
252 n1 = n1->next;
253 n2 = n2->next;
254 }
255
256 if (n2)
257 return 0;
258
259 return 1;
260}
261
262int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit)
263{
264 const struct ebitmap_node *n;
265
266 if (e->highbit < bit)
267 return 0;
268
269 n = e->node;
270 while (n && (n->startbit <= bit)) {
271 if ((n->startbit + EBITMAP_SIZE) > bit)
272 return ebitmap_node_get_bit(n, bit);
273 n = n->next;
274 }
275
276 return 0;
277}
278
279int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
280{
281 struct ebitmap_node *n, *prev, *new;
282
283 prev = NULL;
284 n = e->node;
285 while (n && n->startbit <= bit) {
286 if ((n->startbit + EBITMAP_SIZE) > bit) {
287 if (value) {
288 ebitmap_node_set_bit(n, bit);
289 } else {
290 unsigned int s;
291
292 ebitmap_node_clr_bit(n, bit);
293
294 s = find_first_bit(n->maps, EBITMAP_SIZE);
295 if (s < EBITMAP_SIZE)
296 return 0;
297
298 /* drop this node from the bitmap */
299 if (!n->next) {
300 /*
301 * this was the highest map
302 * within the bitmap
303 */
304 if (prev)
305 e->highbit = prev->startbit
306 + EBITMAP_SIZE;
307 else
308 e->highbit = 0;
309 }
310 if (prev)
311 prev->next = n->next;
312 else
313 e->node = n->next;
314 kmem_cache_free(ebitmap_node_cachep, n);
315 }
316 return 0;
317 }
318 prev = n;
319 n = n->next;
320 }
321
322 if (!value)
323 return 0;
324
325 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
326 if (!new)
327 return -ENOMEM;
328
329 new->startbit = bit - (bit % EBITMAP_SIZE);
330 ebitmap_node_set_bit(new, bit);
331
332 if (!n)
333 /* this node will be the highest map within the bitmap */
334 e->highbit = new->startbit + EBITMAP_SIZE;
335
336 if (prev) {
337 new->next = prev->next;
338 prev->next = new;
339 } else {
340 new->next = e->node;
341 e->node = new;
342 }
343
344 return 0;
345}
346
347void ebitmap_destroy(struct ebitmap *e)
348{
349 struct ebitmap_node *n, *temp;
350
351 if (!e)
352 return;
353
354 n = e->node;
355 while (n) {
356 temp = n;
357 n = n->next;
358 kmem_cache_free(ebitmap_node_cachep, temp);
359 }
360
361 e->highbit = 0;
362 e->node = NULL;
363}
364
365int ebitmap_read(struct ebitmap *e, void *fp)
366{
367 struct ebitmap_node *n = NULL;
368 u32 mapunit, count, startbit, index;
369 __le32 ebitmap_start;
370 u64 map;
371 __le64 mapbits;
372 __le32 buf[3];
373 int rc, i;
374
375 ebitmap_init(e);
376
377 rc = next_entry(buf, fp, sizeof buf);
378 if (rc < 0)
379 goto out;
380
381 mapunit = le32_to_cpu(buf[0]);
382 e->highbit = le32_to_cpu(buf[1]);
383 count = le32_to_cpu(buf[2]);
384
385 if (mapunit != BITS_PER_U64) {
386 pr_err("SELinux: ebitmap: map size %u does not "
387 "match my size %zd (high bit was %d)\n",
388 mapunit, BITS_PER_U64, e->highbit);
389 goto bad;
390 }
391
392 /* round up e->highbit */
393 e->highbit += EBITMAP_SIZE - 1;
394 e->highbit -= (e->highbit % EBITMAP_SIZE);
395
396 if (!e->highbit) {
397 e->node = NULL;
398 goto ok;
399 }
400
401 if (e->highbit && !count)
402 goto bad;
403
404 for (i = 0; i < count; i++) {
405 rc = next_entry(&ebitmap_start, fp, sizeof(u32));
406 if (rc < 0) {
407 pr_err("SELinux: ebitmap: truncated map\n");
408 goto bad;
409 }
410 startbit = le32_to_cpu(ebitmap_start);
411
412 if (startbit & (mapunit - 1)) {
413 pr_err("SELinux: ebitmap start bit (%d) is "
414 "not a multiple of the map unit size (%u)\n",
415 startbit, mapunit);
416 goto bad;
417 }
418 if (startbit > e->highbit - mapunit) {
419 pr_err("SELinux: ebitmap start bit (%d) is "
420 "beyond the end of the bitmap (%u)\n",
421 startbit, (e->highbit - mapunit));
422 goto bad;
423 }
424
425 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
426 struct ebitmap_node *tmp;
427 tmp = kmem_cache_zalloc(ebitmap_node_cachep, GFP_KERNEL);
428 if (!tmp) {
429 pr_err("SELinux: ebitmap: out of memory\n");
430 rc = -ENOMEM;
431 goto bad;
432 }
433 /* round down */
434 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
435 if (n)
436 n->next = tmp;
437 else
438 e->node = tmp;
439 n = tmp;
440 } else if (startbit <= n->startbit) {
441 pr_err("SELinux: ebitmap: start bit %d"
442 " comes after start bit %d\n",
443 startbit, n->startbit);
444 goto bad;
445 }
446
447 rc = next_entry(&mapbits, fp, sizeof(u64));
448 if (rc < 0) {
449 pr_err("SELinux: ebitmap: truncated map\n");
450 goto bad;
451 }
452 map = le64_to_cpu(mapbits);
453
454 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
455 while (map) {
456 n->maps[index++] = map & (-1UL);
457 map = EBITMAP_SHIFT_UNIT_SIZE(map);
458 }
459 }
460ok:
461 rc = 0;
462out:
463 return rc;
464bad:
465 if (!rc)
466 rc = -EINVAL;
467 ebitmap_destroy(e);
468 goto out;
469}
470
471int ebitmap_write(const struct ebitmap *e, void *fp)
472{
473 struct ebitmap_node *n;
474 u32 count;
475 __le32 buf[3];
476 u64 map;
477 int bit, last_bit, last_startbit, rc;
478
479 buf[0] = cpu_to_le32(BITS_PER_U64);
480
481 count = 0;
482 last_bit = 0;
483 last_startbit = -1;
484 ebitmap_for_each_positive_bit(e, n, bit) {
485 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
486 count++;
487 last_startbit = rounddown(bit, BITS_PER_U64);
488 }
489 last_bit = roundup(bit + 1, BITS_PER_U64);
490 }
491 buf[1] = cpu_to_le32(last_bit);
492 buf[2] = cpu_to_le32(count);
493
494 rc = put_entry(buf, sizeof(u32), 3, fp);
495 if (rc)
496 return rc;
497
498 map = 0;
499 last_startbit = INT_MIN;
500 ebitmap_for_each_positive_bit(e, n, bit) {
501 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
502 __le64 buf64[1];
503
504 /* this is the very first bit */
505 if (!map) {
506 last_startbit = rounddown(bit, BITS_PER_U64);
507 map = (u64)1 << (bit - last_startbit);
508 continue;
509 }
510
511 /* write the last node */
512 buf[0] = cpu_to_le32(last_startbit);
513 rc = put_entry(buf, sizeof(u32), 1, fp);
514 if (rc)
515 return rc;
516
517 buf64[0] = cpu_to_le64(map);
518 rc = put_entry(buf64, sizeof(u64), 1, fp);
519 if (rc)
520 return rc;
521
522 /* set up for the next node */
523 map = 0;
524 last_startbit = rounddown(bit, BITS_PER_U64);
525 }
526 map |= (u64)1 << (bit - last_startbit);
527 }
528 /* write the last node */
529 if (map) {
530 __le64 buf64[1];
531
532 /* write the last node */
533 buf[0] = cpu_to_le32(last_startbit);
534 rc = put_entry(buf, sizeof(u32), 1, fp);
535 if (rc)
536 return rc;
537
538 buf64[0] = cpu_to_le64(map);
539 rc = put_entry(buf64, sizeof(u64), 1, fp);
540 if (rc)
541 return rc;
542 }
543 return 0;
544}
545
546u32 ebitmap_hash(const struct ebitmap *e, u32 hash)
547{
548 struct ebitmap_node *node;
549
550 /* need to change hash even if ebitmap is empty */
551 hash = jhash_1word(e->highbit, hash);
552 for (node = e->node; node; node = node->next) {
553 hash = jhash_1word(node->startbit, hash);
554 hash = jhash(node->maps, sizeof(node->maps), hash);
555 }
556 return hash;
557}
558
559void __init ebitmap_cache_init(void)
560{
561 ebitmap_node_cachep = kmem_cache_create("ebitmap_node",
562 sizeof(struct ebitmap_node),
563 0, SLAB_PANIC, NULL);
564}
1/*
2 * Implementation of the extensible bitmap type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6/*
7 * Updated: Hewlett-Packard <paul@paul-moore.com>
8 *
9 * Added support to import/export the NetLabel category bitmap
10 *
11 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
12 */
13/*
14 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
15 * Applied standard bit operations to improve bitmap scanning.
16 */
17
18#include <linux/kernel.h>
19#include <linux/slab.h>
20#include <linux/errno.h>
21#include <net/netlabel.h>
22#include "ebitmap.h"
23#include "policydb.h"
24
25#define BITS_PER_U64 (sizeof(u64) * 8)
26
27int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
28{
29 struct ebitmap_node *n1, *n2;
30
31 if (e1->highbit != e2->highbit)
32 return 0;
33
34 n1 = e1->node;
35 n2 = e2->node;
36 while (n1 && n2 &&
37 (n1->startbit == n2->startbit) &&
38 !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
39 n1 = n1->next;
40 n2 = n2->next;
41 }
42
43 if (n1 || n2)
44 return 0;
45
46 return 1;
47}
48
49int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
50{
51 struct ebitmap_node *n, *new, *prev;
52
53 ebitmap_init(dst);
54 n = src->node;
55 prev = NULL;
56 while (n) {
57 new = kzalloc(sizeof(*new), GFP_ATOMIC);
58 if (!new) {
59 ebitmap_destroy(dst);
60 return -ENOMEM;
61 }
62 new->startbit = n->startbit;
63 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
64 new->next = NULL;
65 if (prev)
66 prev->next = new;
67 else
68 dst->node = new;
69 prev = new;
70 n = n->next;
71 }
72
73 dst->highbit = src->highbit;
74 return 0;
75}
76
77#ifdef CONFIG_NETLABEL
78/**
79 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
80 * @ebmap: the ebitmap to export
81 * @catmap: the NetLabel category bitmap
82 *
83 * Description:
84 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
85 * Returns zero on success, negative values on error.
86 *
87 */
88int ebitmap_netlbl_export(struct ebitmap *ebmap,
89 struct netlbl_lsm_secattr_catmap **catmap)
90{
91 struct ebitmap_node *e_iter = ebmap->node;
92 struct netlbl_lsm_secattr_catmap *c_iter;
93 u32 cmap_idx, cmap_sft;
94 int i;
95
96 /* NetLabel's NETLBL_CATMAP_MAPTYPE is defined as an array of u64,
97 * however, it is not always compatible with an array of unsigned long
98 * in ebitmap_node.
99 * In addition, you should pay attention the following implementation
100 * assumes unsigned long has a width equal with or less than 64-bit.
101 */
102
103 if (e_iter == NULL) {
104 *catmap = NULL;
105 return 0;
106 }
107
108 c_iter = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
109 if (c_iter == NULL)
110 return -ENOMEM;
111 *catmap = c_iter;
112 c_iter->startbit = e_iter->startbit & ~(NETLBL_CATMAP_SIZE - 1);
113
114 while (e_iter) {
115 for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
116 unsigned int delta, e_startbit, c_endbit;
117
118 e_startbit = e_iter->startbit + i * EBITMAP_UNIT_SIZE;
119 c_endbit = c_iter->startbit + NETLBL_CATMAP_SIZE;
120 if (e_startbit >= c_endbit) {
121 c_iter->next
122 = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
123 if (c_iter->next == NULL)
124 goto netlbl_export_failure;
125 c_iter = c_iter->next;
126 c_iter->startbit
127 = e_startbit & ~(NETLBL_CATMAP_SIZE - 1);
128 }
129 delta = e_startbit - c_iter->startbit;
130 cmap_idx = delta / NETLBL_CATMAP_MAPSIZE;
131 cmap_sft = delta % NETLBL_CATMAP_MAPSIZE;
132 c_iter->bitmap[cmap_idx]
133 |= e_iter->maps[i] << cmap_sft;
134 }
135 e_iter = e_iter->next;
136 }
137
138 return 0;
139
140netlbl_export_failure:
141 netlbl_secattr_catmap_free(*catmap);
142 return -ENOMEM;
143}
144
145/**
146 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
147 * @ebmap: the ebitmap to import
148 * @catmap: the NetLabel category bitmap
149 *
150 * Description:
151 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
152 * Returns zero on success, negative values on error.
153 *
154 */
155int ebitmap_netlbl_import(struct ebitmap *ebmap,
156 struct netlbl_lsm_secattr_catmap *catmap)
157{
158 struct ebitmap_node *e_iter = NULL;
159 struct ebitmap_node *emap_prev = NULL;
160 struct netlbl_lsm_secattr_catmap *c_iter = catmap;
161 u32 c_idx, c_pos, e_idx, e_sft;
162
163 /* NetLabel's NETLBL_CATMAP_MAPTYPE is defined as an array of u64,
164 * however, it is not always compatible with an array of unsigned long
165 * in ebitmap_node.
166 * In addition, you should pay attention the following implementation
167 * assumes unsigned long has a width equal with or less than 64-bit.
168 */
169
170 do {
171 for (c_idx = 0; c_idx < NETLBL_CATMAP_MAPCNT; c_idx++) {
172 unsigned int delta;
173 u64 map = c_iter->bitmap[c_idx];
174
175 if (!map)
176 continue;
177
178 c_pos = c_iter->startbit
179 + c_idx * NETLBL_CATMAP_MAPSIZE;
180 if (!e_iter
181 || c_pos >= e_iter->startbit + EBITMAP_SIZE) {
182 e_iter = kzalloc(sizeof(*e_iter), GFP_ATOMIC);
183 if (!e_iter)
184 goto netlbl_import_failure;
185 e_iter->startbit
186 = c_pos - (c_pos % EBITMAP_SIZE);
187 if (emap_prev == NULL)
188 ebmap->node = e_iter;
189 else
190 emap_prev->next = e_iter;
191 emap_prev = e_iter;
192 }
193 delta = c_pos - e_iter->startbit;
194 e_idx = delta / EBITMAP_UNIT_SIZE;
195 e_sft = delta % EBITMAP_UNIT_SIZE;
196 while (map) {
197 e_iter->maps[e_idx++] |= map & (-1UL);
198 map = EBITMAP_SHIFT_UNIT_SIZE(map);
199 }
200 }
201 c_iter = c_iter->next;
202 } while (c_iter);
203 if (e_iter != NULL)
204 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
205 else
206 ebitmap_destroy(ebmap);
207
208 return 0;
209
210netlbl_import_failure:
211 ebitmap_destroy(ebmap);
212 return -ENOMEM;
213}
214#endif /* CONFIG_NETLABEL */
215
216/*
217 * Check to see if all the bits set in e2 are also set in e1. Optionally,
218 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
219 * last_e2bit.
220 */
221int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
222{
223 struct ebitmap_node *n1, *n2;
224 int i;
225
226 if (e1->highbit < e2->highbit)
227 return 0;
228
229 n1 = e1->node;
230 n2 = e2->node;
231
232 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
233 if (n1->startbit < n2->startbit) {
234 n1 = n1->next;
235 continue;
236 }
237 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
238 i--; /* Skip trailing NULL map entries */
239 if (last_e2bit && (i >= 0)) {
240 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
241 __fls(n2->maps[i]);
242 if (lastsetbit > last_e2bit)
243 return 0;
244 }
245
246 while (i >= 0) {
247 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
248 return 0;
249 i--;
250 }
251
252 n1 = n1->next;
253 n2 = n2->next;
254 }
255
256 if (n2)
257 return 0;
258
259 return 1;
260}
261
262int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
263{
264 struct ebitmap_node *n;
265
266 if (e->highbit < bit)
267 return 0;
268
269 n = e->node;
270 while (n && (n->startbit <= bit)) {
271 if ((n->startbit + EBITMAP_SIZE) > bit)
272 return ebitmap_node_get_bit(n, bit);
273 n = n->next;
274 }
275
276 return 0;
277}
278
279int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
280{
281 struct ebitmap_node *n, *prev, *new;
282
283 prev = NULL;
284 n = e->node;
285 while (n && n->startbit <= bit) {
286 if ((n->startbit + EBITMAP_SIZE) > bit) {
287 if (value) {
288 ebitmap_node_set_bit(n, bit);
289 } else {
290 unsigned int s;
291
292 ebitmap_node_clr_bit(n, bit);
293
294 s = find_first_bit(n->maps, EBITMAP_SIZE);
295 if (s < EBITMAP_SIZE)
296 return 0;
297
298 /* drop this node from the bitmap */
299 if (!n->next) {
300 /*
301 * this was the highest map
302 * within the bitmap
303 */
304 if (prev)
305 e->highbit = prev->startbit
306 + EBITMAP_SIZE;
307 else
308 e->highbit = 0;
309 }
310 if (prev)
311 prev->next = n->next;
312 else
313 e->node = n->next;
314 kfree(n);
315 }
316 return 0;
317 }
318 prev = n;
319 n = n->next;
320 }
321
322 if (!value)
323 return 0;
324
325 new = kzalloc(sizeof(*new), GFP_ATOMIC);
326 if (!new)
327 return -ENOMEM;
328
329 new->startbit = bit - (bit % EBITMAP_SIZE);
330 ebitmap_node_set_bit(new, bit);
331
332 if (!n)
333 /* this node will be the highest map within the bitmap */
334 e->highbit = new->startbit + EBITMAP_SIZE;
335
336 if (prev) {
337 new->next = prev->next;
338 prev->next = new;
339 } else {
340 new->next = e->node;
341 e->node = new;
342 }
343
344 return 0;
345}
346
347void ebitmap_destroy(struct ebitmap *e)
348{
349 struct ebitmap_node *n, *temp;
350
351 if (!e)
352 return;
353
354 n = e->node;
355 while (n) {
356 temp = n;
357 n = n->next;
358 kfree(temp);
359 }
360
361 e->highbit = 0;
362 e->node = NULL;
363 return;
364}
365
366int ebitmap_read(struct ebitmap *e, void *fp)
367{
368 struct ebitmap_node *n = NULL;
369 u32 mapunit, count, startbit, index;
370 u64 map;
371 __le32 buf[3];
372 int rc, i;
373
374 ebitmap_init(e);
375
376 rc = next_entry(buf, fp, sizeof buf);
377 if (rc < 0)
378 goto out;
379
380 mapunit = le32_to_cpu(buf[0]);
381 e->highbit = le32_to_cpu(buf[1]);
382 count = le32_to_cpu(buf[2]);
383
384 if (mapunit != BITS_PER_U64) {
385 printk(KERN_ERR "SELinux: ebitmap: map size %u does not "
386 "match my size %Zd (high bit was %d)\n",
387 mapunit, BITS_PER_U64, e->highbit);
388 goto bad;
389 }
390
391 /* round up e->highbit */
392 e->highbit += EBITMAP_SIZE - 1;
393 e->highbit -= (e->highbit % EBITMAP_SIZE);
394
395 if (!e->highbit) {
396 e->node = NULL;
397 goto ok;
398 }
399
400 for (i = 0; i < count; i++) {
401 rc = next_entry(&startbit, fp, sizeof(u32));
402 if (rc < 0) {
403 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
404 goto bad;
405 }
406 startbit = le32_to_cpu(startbit);
407
408 if (startbit & (mapunit - 1)) {
409 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
410 "not a multiple of the map unit size (%u)\n",
411 startbit, mapunit);
412 goto bad;
413 }
414 if (startbit > e->highbit - mapunit) {
415 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
416 "beyond the end of the bitmap (%u)\n",
417 startbit, (e->highbit - mapunit));
418 goto bad;
419 }
420
421 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
422 struct ebitmap_node *tmp;
423 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
424 if (!tmp) {
425 printk(KERN_ERR
426 "SELinux: ebitmap: out of memory\n");
427 rc = -ENOMEM;
428 goto bad;
429 }
430 /* round down */
431 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
432 if (n)
433 n->next = tmp;
434 else
435 e->node = tmp;
436 n = tmp;
437 } else if (startbit <= n->startbit) {
438 printk(KERN_ERR "SELinux: ebitmap: start bit %d"
439 " comes after start bit %d\n",
440 startbit, n->startbit);
441 goto bad;
442 }
443
444 rc = next_entry(&map, fp, sizeof(u64));
445 if (rc < 0) {
446 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
447 goto bad;
448 }
449 map = le64_to_cpu(map);
450
451 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
452 while (map) {
453 n->maps[index++] = map & (-1UL);
454 map = EBITMAP_SHIFT_UNIT_SIZE(map);
455 }
456 }
457ok:
458 rc = 0;
459out:
460 return rc;
461bad:
462 if (!rc)
463 rc = -EINVAL;
464 ebitmap_destroy(e);
465 goto out;
466}
467
468int ebitmap_write(struct ebitmap *e, void *fp)
469{
470 struct ebitmap_node *n;
471 u32 count;
472 __le32 buf[3];
473 u64 map;
474 int bit, last_bit, last_startbit, rc;
475
476 buf[0] = cpu_to_le32(BITS_PER_U64);
477
478 count = 0;
479 last_bit = 0;
480 last_startbit = -1;
481 ebitmap_for_each_positive_bit(e, n, bit) {
482 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
483 count++;
484 last_startbit = rounddown(bit, BITS_PER_U64);
485 }
486 last_bit = roundup(bit + 1, BITS_PER_U64);
487 }
488 buf[1] = cpu_to_le32(last_bit);
489 buf[2] = cpu_to_le32(count);
490
491 rc = put_entry(buf, sizeof(u32), 3, fp);
492 if (rc)
493 return rc;
494
495 map = 0;
496 last_startbit = INT_MIN;
497 ebitmap_for_each_positive_bit(e, n, bit) {
498 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
499 __le64 buf64[1];
500
501 /* this is the very first bit */
502 if (!map) {
503 last_startbit = rounddown(bit, BITS_PER_U64);
504 map = (u64)1 << (bit - last_startbit);
505 continue;
506 }
507
508 /* write the last node */
509 buf[0] = cpu_to_le32(last_startbit);
510 rc = put_entry(buf, sizeof(u32), 1, fp);
511 if (rc)
512 return rc;
513
514 buf64[0] = cpu_to_le64(map);
515 rc = put_entry(buf64, sizeof(u64), 1, fp);
516 if (rc)
517 return rc;
518
519 /* set up for the next node */
520 map = 0;
521 last_startbit = rounddown(bit, BITS_PER_U64);
522 }
523 map |= (u64)1 << (bit - last_startbit);
524 }
525 /* write the last node */
526 if (map) {
527 __le64 buf64[1];
528
529 /* write the last node */
530 buf[0] = cpu_to_le32(last_startbit);
531 rc = put_entry(buf, sizeof(u32), 1, fp);
532 if (rc)
533 return rc;
534
535 buf64[0] = cpu_to_le64(map);
536 rc = put_entry(buf64, sizeof(u64), 1, fp);
537 if (rc)
538 return rc;
539 }
540 return 0;
541}