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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
216int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
217{
218 struct ebitmap_node *n1, *n2;
219 int i;
220
221 if (e1->highbit < e2->highbit)
222 return 0;
223
224 n1 = e1->node;
225 n2 = e2->node;
226 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
227 if (n1->startbit < n2->startbit) {
228 n1 = n1->next;
229 continue;
230 }
231 for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
232 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
233 return 0;
234 }
235
236 n1 = n1->next;
237 n2 = n2->next;
238 }
239
240 if (n2)
241 return 0;
242
243 return 1;
244}
245
246int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
247{
248 struct ebitmap_node *n;
249
250 if (e->highbit < bit)
251 return 0;
252
253 n = e->node;
254 while (n && (n->startbit <= bit)) {
255 if ((n->startbit + EBITMAP_SIZE) > bit)
256 return ebitmap_node_get_bit(n, bit);
257 n = n->next;
258 }
259
260 return 0;
261}
262
263int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
264{
265 struct ebitmap_node *n, *prev, *new;
266
267 prev = NULL;
268 n = e->node;
269 while (n && n->startbit <= bit) {
270 if ((n->startbit + EBITMAP_SIZE) > bit) {
271 if (value) {
272 ebitmap_node_set_bit(n, bit);
273 } else {
274 unsigned int s;
275
276 ebitmap_node_clr_bit(n, bit);
277
278 s = find_first_bit(n->maps, EBITMAP_SIZE);
279 if (s < EBITMAP_SIZE)
280 return 0;
281
282 /* drop this node from the bitmap */
283 if (!n->next) {
284 /*
285 * this was the highest map
286 * within the bitmap
287 */
288 if (prev)
289 e->highbit = prev->startbit
290 + EBITMAP_SIZE;
291 else
292 e->highbit = 0;
293 }
294 if (prev)
295 prev->next = n->next;
296 else
297 e->node = n->next;
298 kfree(n);
299 }
300 return 0;
301 }
302 prev = n;
303 n = n->next;
304 }
305
306 if (!value)
307 return 0;
308
309 new = kzalloc(sizeof(*new), GFP_ATOMIC);
310 if (!new)
311 return -ENOMEM;
312
313 new->startbit = bit - (bit % EBITMAP_SIZE);
314 ebitmap_node_set_bit(new, bit);
315
316 if (!n)
317 /* this node will be the highest map within the bitmap */
318 e->highbit = new->startbit + EBITMAP_SIZE;
319
320 if (prev) {
321 new->next = prev->next;
322 prev->next = new;
323 } else {
324 new->next = e->node;
325 e->node = new;
326 }
327
328 return 0;
329}
330
331void ebitmap_destroy(struct ebitmap *e)
332{
333 struct ebitmap_node *n, *temp;
334
335 if (!e)
336 return;
337
338 n = e->node;
339 while (n) {
340 temp = n;
341 n = n->next;
342 kfree(temp);
343 }
344
345 e->highbit = 0;
346 e->node = NULL;
347 return;
348}
349
350int ebitmap_read(struct ebitmap *e, void *fp)
351{
352 struct ebitmap_node *n = NULL;
353 u32 mapunit, count, startbit, index;
354 u64 map;
355 __le32 buf[3];
356 int rc, i;
357
358 ebitmap_init(e);
359
360 rc = next_entry(buf, fp, sizeof buf);
361 if (rc < 0)
362 goto out;
363
364 mapunit = le32_to_cpu(buf[0]);
365 e->highbit = le32_to_cpu(buf[1]);
366 count = le32_to_cpu(buf[2]);
367
368 if (mapunit != BITS_PER_U64) {
369 printk(KERN_ERR "SELinux: ebitmap: map size %u does not "
370 "match my size %Zd (high bit was %d)\n",
371 mapunit, BITS_PER_U64, e->highbit);
372 goto bad;
373 }
374
375 /* round up e->highbit */
376 e->highbit += EBITMAP_SIZE - 1;
377 e->highbit -= (e->highbit % EBITMAP_SIZE);
378
379 if (!e->highbit) {
380 e->node = NULL;
381 goto ok;
382 }
383
384 for (i = 0; i < count; i++) {
385 rc = next_entry(&startbit, fp, sizeof(u32));
386 if (rc < 0) {
387 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
388 goto bad;
389 }
390 startbit = le32_to_cpu(startbit);
391
392 if (startbit & (mapunit - 1)) {
393 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
394 "not a multiple of the map unit size (%u)\n",
395 startbit, mapunit);
396 goto bad;
397 }
398 if (startbit > e->highbit - mapunit) {
399 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
400 "beyond the end of the bitmap (%u)\n",
401 startbit, (e->highbit - mapunit));
402 goto bad;
403 }
404
405 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
406 struct ebitmap_node *tmp;
407 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
408 if (!tmp) {
409 printk(KERN_ERR
410 "SELinux: ebitmap: out of memory\n");
411 rc = -ENOMEM;
412 goto bad;
413 }
414 /* round down */
415 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
416 if (n)
417 n->next = tmp;
418 else
419 e->node = tmp;
420 n = tmp;
421 } else if (startbit <= n->startbit) {
422 printk(KERN_ERR "SELinux: ebitmap: start bit %d"
423 " comes after start bit %d\n",
424 startbit, n->startbit);
425 goto bad;
426 }
427
428 rc = next_entry(&map, fp, sizeof(u64));
429 if (rc < 0) {
430 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
431 goto bad;
432 }
433 map = le64_to_cpu(map);
434
435 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
436 while (map) {
437 n->maps[index++] = map & (-1UL);
438 map = EBITMAP_SHIFT_UNIT_SIZE(map);
439 }
440 }
441ok:
442 rc = 0;
443out:
444 return rc;
445bad:
446 if (!rc)
447 rc = -EINVAL;
448 ebitmap_destroy(e);
449 goto out;
450}
451
452int ebitmap_write(struct ebitmap *e, void *fp)
453{
454 struct ebitmap_node *n;
455 u32 count;
456 __le32 buf[3];
457 u64 map;
458 int bit, last_bit, last_startbit, rc;
459
460 buf[0] = cpu_to_le32(BITS_PER_U64);
461
462 count = 0;
463 last_bit = 0;
464 last_startbit = -1;
465 ebitmap_for_each_positive_bit(e, n, bit) {
466 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
467 count++;
468 last_startbit = rounddown(bit, BITS_PER_U64);
469 }
470 last_bit = roundup(bit + 1, BITS_PER_U64);
471 }
472 buf[1] = cpu_to_le32(last_bit);
473 buf[2] = cpu_to_le32(count);
474
475 rc = put_entry(buf, sizeof(u32), 3, fp);
476 if (rc)
477 return rc;
478
479 map = 0;
480 last_startbit = INT_MIN;
481 ebitmap_for_each_positive_bit(e, n, bit) {
482 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
483 __le64 buf64[1];
484
485 /* this is the very first bit */
486 if (!map) {
487 last_startbit = rounddown(bit, BITS_PER_U64);
488 map = (u64)1 << (bit - last_startbit);
489 continue;
490 }
491
492 /* write the last node */
493 buf[0] = cpu_to_le32(last_startbit);
494 rc = put_entry(buf, sizeof(u32), 1, fp);
495 if (rc)
496 return rc;
497
498 buf64[0] = cpu_to_le64(map);
499 rc = put_entry(buf64, sizeof(u64), 1, fp);
500 if (rc)
501 return rc;
502
503 /* set up for the next node */
504 map = 0;
505 last_startbit = rounddown(bit, BITS_PER_U64);
506 }
507 map |= (u64)1 << (bit - last_startbit);
508 }
509 /* write the last node */
510 if (map) {
511 __le64 buf64[1];
512
513 /* write the last node */
514 buf[0] = cpu_to_le32(last_startbit);
515 rc = put_entry(buf, sizeof(u32), 1, fp);
516 if (rc)
517 return rc;
518
519 buf64[0] = cpu_to_le64(map);
520 rc = put_entry(buf64, sizeof(u64), 1, fp);
521 if (rc)
522 return rc;
523 }
524 return 0;
525}
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Implementation of the extensible bitmap type.
4 *
5 * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
6 */
7/*
8 * Updated: Hewlett-Packard <paul@paul-moore.com>
9 * Added support to import/export the NetLabel category bitmap
10 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
11 *
12 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
13 * Applied standard bit operations to improve bitmap scanning.
14 */
15
16#include <linux/kernel.h>
17#include <linux/slab.h>
18#include <linux/errno.h>
19#include <linux/jhash.h>
20#include <net/netlabel.h>
21#include "ebitmap.h"
22#include "policydb.h"
23
24#define BITS_PER_U64 ((u32)(sizeof(u64) * 8))
25
26static struct kmem_cache *ebitmap_node_cachep __ro_after_init;
27
28int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2)
29{
30 const struct ebitmap_node *n1, *n2;
31
32 if (e1->highbit != e2->highbit)
33 return 0;
34
35 n1 = e1->node;
36 n2 = e2->node;
37 while (n1 && n2 && (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, const struct ebitmap *src)
50{
51 struct ebitmap_node *new, *prev;
52 const struct ebitmap_node *n;
53
54 ebitmap_init(dst);
55 n = src->node;
56 prev = NULL;
57 while (n) {
58 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
59 if (!new) {
60 ebitmap_destroy(dst);
61 return -ENOMEM;
62 }
63 new->startbit = n->startbit;
64 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
65 new->next = NULL;
66 if (prev)
67 prev->next = new;
68 else
69 dst->node = new;
70 prev = new;
71 n = n->next;
72 }
73
74 dst->highbit = src->highbit;
75 return 0;
76}
77
78int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1,
79 const struct ebitmap *e2)
80{
81 struct ebitmap_node *n;
82 u32 bit;
83 int rc;
84
85 ebitmap_init(dst);
86
87 ebitmap_for_each_positive_bit(e1, n, bit)
88 {
89 if (ebitmap_get_bit(e2, bit)) {
90 rc = ebitmap_set_bit(dst, bit, 1);
91 if (rc < 0)
92 return rc;
93 }
94 }
95 return 0;
96}
97
98#ifdef CONFIG_NETLABEL
99/**
100 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
101 * @ebmap: the ebitmap to export
102 * @catmap: the NetLabel category bitmap
103 *
104 * Description:
105 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
106 * Returns zero on success, negative values on error.
107 *
108 */
109int ebitmap_netlbl_export(struct ebitmap *ebmap,
110 struct netlbl_lsm_catmap **catmap)
111{
112 struct ebitmap_node *e_iter = ebmap->node;
113 unsigned long e_map;
114 u32 offset;
115 unsigned int iter;
116 int rc;
117
118 if (e_iter == NULL) {
119 *catmap = NULL;
120 return 0;
121 }
122
123 if (*catmap != NULL)
124 netlbl_catmap_free(*catmap);
125 *catmap = NULL;
126
127 while (e_iter) {
128 offset = e_iter->startbit;
129 for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
130 e_map = e_iter->maps[iter];
131 if (e_map != 0) {
132 rc = netlbl_catmap_setlong(catmap, offset,
133 e_map, GFP_ATOMIC);
134 if (rc != 0)
135 goto netlbl_export_failure;
136 }
137 offset += EBITMAP_UNIT_SIZE;
138 }
139 e_iter = e_iter->next;
140 }
141
142 return 0;
143
144netlbl_export_failure:
145 netlbl_catmap_free(*catmap);
146 return -ENOMEM;
147}
148
149/**
150 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
151 * @ebmap: the ebitmap to import
152 * @catmap: the NetLabel category bitmap
153 *
154 * Description:
155 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
156 * Returns zero on success, negative values on error.
157 *
158 */
159int ebitmap_netlbl_import(struct ebitmap *ebmap,
160 struct netlbl_lsm_catmap *catmap)
161{
162 int rc;
163 struct ebitmap_node *e_iter = NULL;
164 struct ebitmap_node *e_prev = NULL;
165 u32 offset = 0, idx;
166 unsigned long bitmap;
167
168 for (;;) {
169 rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
170 if (rc < 0)
171 goto netlbl_import_failure;
172 if (offset == (u32)-1)
173 return 0;
174
175 /* don't waste ebitmap space if the netlabel bitmap is empty */
176 if (bitmap == 0) {
177 offset += EBITMAP_UNIT_SIZE;
178 continue;
179 }
180
181 if (e_iter == NULL ||
182 offset >= e_iter->startbit + EBITMAP_SIZE) {
183 e_prev = e_iter;
184 e_iter = kmem_cache_zalloc(ebitmap_node_cachep,
185 GFP_ATOMIC);
186 if (e_iter == NULL)
187 goto netlbl_import_failure;
188 e_iter->startbit = offset - (offset % EBITMAP_SIZE);
189 if (e_prev == NULL)
190 ebmap->node = e_iter;
191 else
192 e_prev->next = e_iter;
193 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
194 }
195
196 /* offset will always be aligned to an unsigned long */
197 idx = EBITMAP_NODE_INDEX(e_iter, offset);
198 e_iter->maps[idx] = bitmap;
199
200 /* next */
201 offset += EBITMAP_UNIT_SIZE;
202 }
203
204 /* NOTE: we should never reach this return */
205 return 0;
206
207netlbl_import_failure:
208 ebitmap_destroy(ebmap);
209 return -ENOMEM;
210}
211#endif /* CONFIG_NETLABEL */
212
213/*
214 * Check to see if all the bits set in e2 are also set in e1. Optionally,
215 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
216 * last_e2bit.
217 */
218int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2,
219 u32 last_e2bit)
220{
221 const struct ebitmap_node *n1, *n2;
222 int i;
223
224 if (e1->highbit < e2->highbit)
225 return 0;
226
227 n1 = e1->node;
228 n2 = e2->node;
229
230 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
231 if (n1->startbit < n2->startbit) {
232 n1 = n1->next;
233 continue;
234 }
235 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i];)
236 i--; /* Skip trailing NULL map entries */
237 if (last_e2bit && (i >= 0)) {
238 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
239 __fls(n2->maps[i]);
240 if (lastsetbit > last_e2bit)
241 return 0;
242 }
243
244 while (i >= 0) {
245 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
246 return 0;
247 i--;
248 }
249
250 n1 = n1->next;
251 n2 = n2->next;
252 }
253
254 if (n2)
255 return 0;
256
257 return 1;
258}
259
260int ebitmap_get_bit(const struct ebitmap *e, u32 bit)
261{
262 const struct ebitmap_node *n;
263
264 if (e->highbit < bit)
265 return 0;
266
267 n = e->node;
268 while (n && (n->startbit <= bit)) {
269 if ((n->startbit + EBITMAP_SIZE) > bit)
270 return ebitmap_node_get_bit(n, bit);
271 n = n->next;
272 }
273
274 return 0;
275}
276
277int ebitmap_set_bit(struct ebitmap *e, u32 bit, int value)
278{
279 struct ebitmap_node *n, *prev, *new;
280
281 prev = NULL;
282 n = e->node;
283 while (n && n->startbit <= bit) {
284 if ((n->startbit + EBITMAP_SIZE) > bit) {
285 if (value) {
286 ebitmap_node_set_bit(n, bit);
287 } else {
288 u32 s;
289
290 ebitmap_node_clr_bit(n, bit);
291
292 s = find_first_bit(n->maps, EBITMAP_SIZE);
293 if (s < EBITMAP_SIZE)
294 return 0;
295
296 /* drop this node from the bitmap */
297 if (!n->next) {
298 /*
299 * this was the highest map
300 * within the bitmap
301 */
302 if (prev)
303 e->highbit = prev->startbit +
304 EBITMAP_SIZE;
305 else
306 e->highbit = 0;
307 }
308 if (prev)
309 prev->next = n->next;
310 else
311 e->node = n->next;
312 kmem_cache_free(ebitmap_node_cachep, n);
313 }
314 return 0;
315 }
316 prev = n;
317 n = n->next;
318 }
319
320 if (!value)
321 return 0;
322
323 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
324 if (!new)
325 return -ENOMEM;
326
327 new->startbit = bit - (bit % EBITMAP_SIZE);
328 ebitmap_node_set_bit(new, bit);
329
330 if (!n)
331 /* this node will be the highest map within the bitmap */
332 e->highbit = new->startbit + EBITMAP_SIZE;
333
334 if (prev) {
335 new->next = prev->next;
336 prev->next = new;
337 } else {
338 new->next = e->node;
339 e->node = new;
340 }
341
342 return 0;
343}
344
345void ebitmap_destroy(struct ebitmap *e)
346{
347 struct ebitmap_node *n, *temp;
348
349 if (!e)
350 return;
351
352 n = e->node;
353 while (n) {
354 temp = n;
355 n = n->next;
356 kmem_cache_free(ebitmap_node_cachep, temp);
357 }
358
359 e->highbit = 0;
360 e->node = NULL;
361}
362
363int ebitmap_read(struct ebitmap *e, void *fp)
364{
365 struct ebitmap_node *n = NULL;
366 u32 mapunit, count, startbit, index, i;
367 __le32 ebitmap_start;
368 u64 map;
369 __le64 mapbits;
370 __le32 buf[3];
371 int rc;
372
373 ebitmap_init(e);
374
375 rc = next_entry(buf, fp, sizeof buf);
376 if (rc < 0)
377 goto out;
378
379 mapunit = le32_to_cpu(buf[0]);
380 e->highbit = le32_to_cpu(buf[1]);
381 count = le32_to_cpu(buf[2]);
382
383 if (mapunit != BITS_PER_U64) {
384 pr_err("SELinux: ebitmap: map size %u does not "
385 "match my size %u (high bit was %u)\n",
386 mapunit, BITS_PER_U64, e->highbit);
387 goto bad;
388 }
389
390 /* round up e->highbit */
391 e->highbit += EBITMAP_SIZE - 1;
392 e->highbit -= (e->highbit % EBITMAP_SIZE);
393
394 if (!e->highbit) {
395 e->node = NULL;
396 goto ok;
397 }
398
399 if (e->highbit && !count)
400 goto bad;
401
402 for (i = 0; i < count; i++) {
403 rc = next_entry(&ebitmap_start, fp, sizeof(u32));
404 if (rc < 0) {
405 pr_err("SELinux: ebitmap: truncated map\n");
406 goto bad;
407 }
408 startbit = le32_to_cpu(ebitmap_start);
409
410 if (startbit & (mapunit - 1)) {
411 pr_err("SELinux: ebitmap start bit (%u) is "
412 "not a multiple of the map unit size (%u)\n",
413 startbit, mapunit);
414 goto bad;
415 }
416 if (startbit > e->highbit - mapunit) {
417 pr_err("SELinux: ebitmap start bit (%u) is "
418 "beyond the end of the bitmap (%u)\n",
419 startbit, (e->highbit - mapunit));
420 goto bad;
421 }
422
423 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
424 struct ebitmap_node *tmp;
425 tmp = kmem_cache_zalloc(ebitmap_node_cachep,
426 GFP_KERNEL);
427 if (!tmp) {
428 pr_err("SELinux: ebitmap: out of memory\n");
429 rc = -ENOMEM;
430 goto bad;
431 }
432 /* round down */
433 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
434 if (n)
435 n->next = tmp;
436 else
437 e->node = tmp;
438 n = tmp;
439 } else if (startbit <= n->startbit) {
440 pr_err("SELinux: ebitmap: start bit %u"
441 " comes after start bit %u\n",
442 startbit, n->startbit);
443 goto bad;
444 }
445
446 rc = next_entry(&mapbits, fp, sizeof(u64));
447 if (rc < 0) {
448 pr_err("SELinux: ebitmap: truncated map\n");
449 goto bad;
450 }
451 map = le64_to_cpu(mapbits);
452 if (!map) {
453 pr_err("SELinux: ebitmap: empty map\n");
454 goto bad;
455 }
456
457 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
458 while (map) {
459 n->maps[index++] = map & (-1UL);
460 map = EBITMAP_SHIFT_UNIT_SIZE(map);
461 }
462 }
463
464 if (n && n->startbit + EBITMAP_SIZE != e->highbit) {
465 pr_err("SELinux: ebitmap: high bit %u is not equal to the expected value %zu\n",
466 e->highbit, n->startbit + EBITMAP_SIZE);
467 goto bad;
468 }
469
470ok:
471 rc = 0;
472out:
473 return rc;
474bad:
475 if (!rc)
476 rc = -EINVAL;
477 ebitmap_destroy(e);
478 goto out;
479}
480
481int ebitmap_write(const struct ebitmap *e, void *fp)
482{
483 struct ebitmap_node *n;
484 u32 bit, count, last_bit, last_startbit;
485 __le32 buf[3];
486 u64 map;
487 int rc;
488
489 buf[0] = cpu_to_le32(BITS_PER_U64);
490
491 count = 0;
492 last_bit = 0;
493 last_startbit = U32_MAX;
494 ebitmap_for_each_positive_bit(e, n, bit)
495 {
496 if (last_startbit == U32_MAX ||
497 rounddown(bit, BITS_PER_U64) > last_startbit) {
498 count++;
499 last_startbit = rounddown(bit, BITS_PER_U64);
500 }
501 last_bit = roundup(bit + 1, BITS_PER_U64);
502 }
503 buf[1] = cpu_to_le32(last_bit);
504 buf[2] = cpu_to_le32(count);
505
506 rc = put_entry(buf, sizeof(u32), 3, fp);
507 if (rc)
508 return rc;
509
510 map = 0;
511 last_startbit = U32_MAX;
512 ebitmap_for_each_positive_bit(e, n, bit)
513 {
514 if (last_startbit == U32_MAX ||
515 rounddown(bit, BITS_PER_U64) > last_startbit) {
516 __le64 buf64[1];
517
518 /* this is the very first bit */
519 if (!map) {
520 last_startbit = rounddown(bit, BITS_PER_U64);
521 map = (u64)1 << (bit - last_startbit);
522 continue;
523 }
524
525 /* write the last node */
526 buf[0] = cpu_to_le32(last_startbit);
527 rc = put_entry(buf, sizeof(u32), 1, fp);
528 if (rc)
529 return rc;
530
531 buf64[0] = cpu_to_le64(map);
532 rc = put_entry(buf64, sizeof(u64), 1, fp);
533 if (rc)
534 return rc;
535
536 /* set up for the next node */
537 map = 0;
538 last_startbit = rounddown(bit, BITS_PER_U64);
539 }
540 map |= (u64)1 << (bit - last_startbit);
541 }
542 /* write the last node */
543 if (map) {
544 __le64 buf64[1];
545
546 /* write the last node */
547 buf[0] = cpu_to_le32(last_startbit);
548 rc = put_entry(buf, sizeof(u32), 1, fp);
549 if (rc)
550 return rc;
551
552 buf64[0] = cpu_to_le64(map);
553 rc = put_entry(buf64, sizeof(u64), 1, fp);
554 if (rc)
555 return rc;
556 }
557 return 0;
558}
559
560u32 ebitmap_hash(const struct ebitmap *e, u32 hash)
561{
562 struct ebitmap_node *node;
563
564 /* need to change hash even if ebitmap is empty */
565 hash = jhash_1word(e->highbit, hash);
566 for (node = e->node; node; node = node->next) {
567 hash = jhash_1word(node->startbit, hash);
568 hash = jhash(node->maps, sizeof(node->maps), hash);
569 }
570 return hash;
571}
572
573void __init ebitmap_cache_init(void)
574{
575 ebitmap_node_cachep = KMEM_CACHE(ebitmap_node, SLAB_PANIC);
576}