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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 (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 int bit, rc;
83
84 ebitmap_init(dst);
85
86 ebitmap_for_each_positive_bit(e1, n, bit)
87 {
88 if (ebitmap_get_bit(e2, bit)) {
89 rc = ebitmap_set_bit(dst, bit, 1);
90 if (rc < 0)
91 return rc;
92 }
93 }
94 return 0;
95}
96
97#ifdef CONFIG_NETLABEL
98/**
99 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
100 * @ebmap: the ebitmap to export
101 * @catmap: the NetLabel category bitmap
102 *
103 * Description:
104 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
105 * Returns zero on success, negative values on error.
106 *
107 */
108int ebitmap_netlbl_export(struct ebitmap *ebmap,
109 struct netlbl_lsm_catmap **catmap)
110{
111 struct ebitmap_node *e_iter = ebmap->node;
112 unsigned long e_map;
113 u32 offset;
114 unsigned int iter;
115 int rc;
116
117 if (e_iter == NULL) {
118 *catmap = NULL;
119 return 0;
120 }
121
122 if (*catmap != NULL)
123 netlbl_catmap_free(*catmap);
124 *catmap = NULL;
125
126 while (e_iter) {
127 offset = e_iter->startbit;
128 for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
129 e_map = e_iter->maps[iter];
130 if (e_map != 0) {
131 rc = netlbl_catmap_setlong(catmap, offset,
132 e_map, GFP_ATOMIC);
133 if (rc != 0)
134 goto netlbl_export_failure;
135 }
136 offset += EBITMAP_UNIT_SIZE;
137 }
138 e_iter = e_iter->next;
139 }
140
141 return 0;
142
143netlbl_export_failure:
144 netlbl_catmap_free(*catmap);
145 return -ENOMEM;
146}
147
148/**
149 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
150 * @ebmap: the ebitmap to import
151 * @catmap: the NetLabel category bitmap
152 *
153 * Description:
154 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
155 * Returns zero on success, negative values on error.
156 *
157 */
158int ebitmap_netlbl_import(struct ebitmap *ebmap,
159 struct netlbl_lsm_catmap *catmap)
160{
161 int rc;
162 struct ebitmap_node *e_iter = NULL;
163 struct ebitmap_node *e_prev = NULL;
164 u32 offset = 0, idx;
165 unsigned long bitmap;
166
167 for (;;) {
168 rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
169 if (rc < 0)
170 goto netlbl_import_failure;
171 if (offset == (u32)-1)
172 return 0;
173
174 /* don't waste ebitmap space if the netlabel bitmap is empty */
175 if (bitmap == 0) {
176 offset += EBITMAP_UNIT_SIZE;
177 continue;
178 }
179
180 if (e_iter == NULL ||
181 offset >= e_iter->startbit + EBITMAP_SIZE) {
182 e_prev = e_iter;
183 e_iter = kmem_cache_zalloc(ebitmap_node_cachep,
184 GFP_ATOMIC);
185 if (e_iter == NULL)
186 goto netlbl_import_failure;
187 e_iter->startbit = offset - (offset % EBITMAP_SIZE);
188 if (e_prev == NULL)
189 ebmap->node = e_iter;
190 else
191 e_prev->next = e_iter;
192 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
193 }
194
195 /* offset will always be aligned to an unsigned long */
196 idx = EBITMAP_NODE_INDEX(e_iter, offset);
197 e_iter->maps[idx] = bitmap;
198
199 /* next */
200 offset += EBITMAP_UNIT_SIZE;
201 }
202
203 /* NOTE: we should never reach this return */
204 return 0;
205
206netlbl_import_failure:
207 ebitmap_destroy(ebmap);
208 return -ENOMEM;
209}
210#endif /* CONFIG_NETLABEL */
211
212/*
213 * Check to see if all the bits set in e2 are also set in e1. Optionally,
214 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
215 * last_e2bit.
216 */
217int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2,
218 u32 last_e2bit)
219{
220 const struct ebitmap_node *n1, *n2;
221 int i;
222
223 if (e1->highbit < e2->highbit)
224 return 0;
225
226 n1 = e1->node;
227 n2 = e2->node;
228
229 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
230 if (n1->startbit < n2->startbit) {
231 n1 = n1->next;
232 continue;
233 }
234 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i];)
235 i--; /* Skip trailing NULL map entries */
236 if (last_e2bit && (i >= 0)) {
237 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
238 __fls(n2->maps[i]);
239 if (lastsetbit > last_e2bit)
240 return 0;
241 }
242
243 while (i >= 0) {
244 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
245 return 0;
246 i--;
247 }
248
249 n1 = n1->next;
250 n2 = n2->next;
251 }
252
253 if (n2)
254 return 0;
255
256 return 1;
257}
258
259int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit)
260{
261 const struct ebitmap_node *n;
262
263 if (e->highbit < bit)
264 return 0;
265
266 n = e->node;
267 while (n && (n->startbit <= bit)) {
268 if ((n->startbit + EBITMAP_SIZE) > bit)
269 return ebitmap_node_get_bit(n, bit);
270 n = n->next;
271 }
272
273 return 0;
274}
275
276int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
277{
278 struct ebitmap_node *n, *prev, *new;
279
280 prev = NULL;
281 n = e->node;
282 while (n && n->startbit <= bit) {
283 if ((n->startbit + EBITMAP_SIZE) > bit) {
284 if (value) {
285 ebitmap_node_set_bit(n, bit);
286 } else {
287 unsigned int s;
288
289 ebitmap_node_clr_bit(n, bit);
290
291 s = find_first_bit(n->maps, EBITMAP_SIZE);
292 if (s < EBITMAP_SIZE)
293 return 0;
294
295 /* drop this node from the bitmap */
296 if (!n->next) {
297 /*
298 * this was the highest map
299 * within the bitmap
300 */
301 if (prev)
302 e->highbit = prev->startbit +
303 EBITMAP_SIZE;
304 else
305 e->highbit = 0;
306 }
307 if (prev)
308 prev->next = n->next;
309 else
310 e->node = n->next;
311 kmem_cache_free(ebitmap_node_cachep, n);
312 }
313 return 0;
314 }
315 prev = n;
316 n = n->next;
317 }
318
319 if (!value)
320 return 0;
321
322 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
323 if (!new)
324 return -ENOMEM;
325
326 new->startbit = bit - (bit % EBITMAP_SIZE);
327 ebitmap_node_set_bit(new, bit);
328
329 if (!n)
330 /* this node will be the highest map within the bitmap */
331 e->highbit = new->startbit + EBITMAP_SIZE;
332
333 if (prev) {
334 new->next = prev->next;
335 prev->next = new;
336 } else {
337 new->next = e->node;
338 e->node = new;
339 }
340
341 return 0;
342}
343
344void ebitmap_destroy(struct ebitmap *e)
345{
346 struct ebitmap_node *n, *temp;
347
348 if (!e)
349 return;
350
351 n = e->node;
352 while (n) {
353 temp = n;
354 n = n->next;
355 kmem_cache_free(ebitmap_node_cachep, temp);
356 }
357
358 e->highbit = 0;
359 e->node = NULL;
360}
361
362int ebitmap_read(struct ebitmap *e, void *fp)
363{
364 struct ebitmap_node *n = NULL;
365 u32 mapunit, count, startbit, index;
366 __le32 ebitmap_start;
367 u64 map;
368 __le64 mapbits;
369 __le32 buf[3];
370 int rc, i;
371
372 ebitmap_init(e);
373
374 rc = next_entry(buf, fp, sizeof buf);
375 if (rc < 0)
376 goto out;
377
378 mapunit = le32_to_cpu(buf[0]);
379 e->highbit = le32_to_cpu(buf[1]);
380 count = le32_to_cpu(buf[2]);
381
382 if (mapunit != BITS_PER_U64) {
383 pr_err("SELinux: ebitmap: map size %u does not "
384 "match my size %zd (high bit was %d)\n",
385 mapunit, BITS_PER_U64, e->highbit);
386 goto bad;
387 }
388
389 /* round up e->highbit */
390 e->highbit += EBITMAP_SIZE - 1;
391 e->highbit -= (e->highbit % EBITMAP_SIZE);
392
393 if (!e->highbit) {
394 e->node = NULL;
395 goto ok;
396 }
397
398 if (e->highbit && !count)
399 goto bad;
400
401 for (i = 0; i < count; i++) {
402 rc = next_entry(&ebitmap_start, fp, sizeof(u32));
403 if (rc < 0) {
404 pr_err("SELinux: ebitmap: truncated map\n");
405 goto bad;
406 }
407 startbit = le32_to_cpu(ebitmap_start);
408
409 if (startbit & (mapunit - 1)) {
410 pr_err("SELinux: ebitmap start bit (%d) is "
411 "not a multiple of the map unit size (%u)\n",
412 startbit, mapunit);
413 goto bad;
414 }
415 if (startbit > e->highbit - mapunit) {
416 pr_err("SELinux: ebitmap start bit (%d) is "
417 "beyond the end of the bitmap (%u)\n",
418 startbit, (e->highbit - mapunit));
419 goto bad;
420 }
421
422 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
423 struct ebitmap_node *tmp;
424 tmp = kmem_cache_zalloc(ebitmap_node_cachep,
425 GFP_KERNEL);
426 if (!tmp) {
427 pr_err("SELinux: ebitmap: out of memory\n");
428 rc = -ENOMEM;
429 goto bad;
430 }
431 /* round down */
432 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
433 if (n)
434 n->next = tmp;
435 else
436 e->node = tmp;
437 n = tmp;
438 } else if (startbit <= n->startbit) {
439 pr_err("SELinux: ebitmap: start bit %d"
440 " comes after start bit %d\n",
441 startbit, n->startbit);
442 goto bad;
443 }
444
445 rc = next_entry(&mapbits, fp, sizeof(u64));
446 if (rc < 0) {
447 pr_err("SELinux: ebitmap: truncated map\n");
448 goto bad;
449 }
450 map = le64_to_cpu(mapbits);
451
452 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
453 while (map) {
454 n->maps[index++] = map & (-1UL);
455 map = EBITMAP_SHIFT_UNIT_SIZE(map);
456 }
457 }
458ok:
459 rc = 0;
460out:
461 return rc;
462bad:
463 if (!rc)
464 rc = -EINVAL;
465 ebitmap_destroy(e);
466 goto out;
467}
468
469int ebitmap_write(const struct ebitmap *e, void *fp)
470{
471 struct ebitmap_node *n;
472 u32 count;
473 __le32 buf[3];
474 u64 map;
475 int bit, last_bit, last_startbit, rc;
476
477 buf[0] = cpu_to_le32(BITS_PER_U64);
478
479 count = 0;
480 last_bit = 0;
481 last_startbit = -1;
482 ebitmap_for_each_positive_bit(e, n, bit)
483 {
484 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
485 count++;
486 last_startbit = rounddown(bit, BITS_PER_U64);
487 }
488 last_bit = roundup(bit + 1, BITS_PER_U64);
489 }
490 buf[1] = cpu_to_le32(last_bit);
491 buf[2] = cpu_to_le32(count);
492
493 rc = put_entry(buf, sizeof(u32), 3, fp);
494 if (rc)
495 return rc;
496
497 map = 0;
498 last_startbit = INT_MIN;
499 ebitmap_for_each_positive_bit(e, n, bit)
500 {
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), 0,
563 SLAB_PANIC, NULL);
564}