1 /*
2 * Implementation of the extensible bitmap type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6 /*
7 * Updated: Hewlett-Packard <paul.moore@hp.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 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
26 {
27 struct ebitmap_node *n1, *n2;
28
29 if (e1->highbit != e2->highbit)
30 return 0;
31
32 n1 = e1->node;
33 n2 = e2->node;
34 while (n1 && n2 &&
35 (n1->startbit == n2->startbit) &&
36 !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
37 n1 = n1->next;
38 n2 = n2->next;
39 }
40
41 if (n1 || n2)
42 return 0;
43
44 return 1;
45 }
46
47 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
48 {
49 struct ebitmap_node *n, *new, *prev;
50
51 ebitmap_init(dst);
52 n = src->node;
53 prev = NULL;
54 while (n) {
55 new = kzalloc(sizeof(*new), GFP_ATOMIC);
56 if (!new) {
57 ebitmap_destroy(dst);
58 return -ENOMEM;
59 }
60 new->startbit = n->startbit;
61 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
62 new->next = NULL;
63 if (prev)
64 prev->next = new;
65 else
66 dst->node = new;
67 prev = new;
68 n = n->next;
69 }
70
71 dst->highbit = src->highbit;
72 return 0;
73 }
74
75 #ifdef CONFIG_NETLABEL
76 /**
77 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
78 * @ebmap: the ebitmap to export
79 * @catmap: the NetLabel category bitmap
80 *
81 * Description:
82 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
83 * Returns zero on success, negative values on error.
84 *
85 */
86 int ebitmap_netlbl_export(struct ebitmap *ebmap,
87 struct netlbl_lsm_secattr_catmap **catmap)
88 {
89 struct ebitmap_node *e_iter = ebmap->node;
90 struct netlbl_lsm_secattr_catmap *c_iter;
91 u32 cmap_idx, cmap_sft;
92 int i;
93
94 /* NetLabel's NETLBL_CATMAP_MAPTYPE is defined as an array of u64,
95 * however, it is not always compatible with an array of unsigned long
96 * in ebitmap_node.
97 * In addition, you should pay attention the following implementation
98 * assumes unsigned long has a width equal with or less than 64-bit.
99 */
100
101 if (e_iter == NULL) {
102 *catmap = NULL;
103 return 0;
104 }
105
106 c_iter = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
107 if (c_iter == NULL)
108 return -ENOMEM;
109 *catmap = c_iter;
110 c_iter->startbit = e_iter->startbit & ~(NETLBL_CATMAP_SIZE - 1);
111
112 while (e_iter) {
113 for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
114 unsigned int delta, e_startbit, c_endbit;
115
116 e_startbit = e_iter->startbit + i * EBITMAP_UNIT_SIZE;
117 c_endbit = c_iter->startbit + NETLBL_CATMAP_SIZE;
118 if (e_startbit >= c_endbit) {
119 c_iter->next
120 = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
121 if (c_iter->next == NULL)
122 goto netlbl_export_failure;
123 c_iter = c_iter->next;
124 c_iter->startbit
125 = e_startbit & ~(NETLBL_CATMAP_SIZE - 1);
126 }
127 delta = e_startbit - c_iter->startbit;
128 cmap_idx = delta / NETLBL_CATMAP_MAPSIZE;
129 cmap_sft = delta % NETLBL_CATMAP_MAPSIZE;
130 c_iter->bitmap[cmap_idx]
131 |= e_iter->maps[cmap_idx] << cmap_sft;
132 }
133 e_iter = e_iter->next;
134 }
135
136 return 0;
137
138 netlbl_export_failure:
139 netlbl_secattr_catmap_free(*catmap);
140 return -ENOMEM;
141 }
142
143 /**
144 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
145 * @ebmap: the ebitmap to import
146 * @catmap: the NetLabel category bitmap
147 *
148 * Description:
149 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
150 * Returns zero on success, negative values on error.
151 *
152 */
153 int ebitmap_netlbl_import(struct ebitmap *ebmap,
154 struct netlbl_lsm_secattr_catmap *catmap)
155 {
156 struct ebitmap_node *e_iter = NULL;
157 struct ebitmap_node *emap_prev = NULL;
158 struct netlbl_lsm_secattr_catmap *c_iter = catmap;
159 u32 c_idx, c_pos, e_idx, e_sft;
160
161 /* NetLabel's NETLBL_CATMAP_MAPTYPE is defined as an array of u64,
162 * however, it is not always compatible with an array of unsigned long
163 * in ebitmap_node.
164 * In addition, you should pay attention the following implementation
165 * assumes unsigned long has a width equal with or less than 64-bit.
166 */
167
168 do {
169 for (c_idx = 0; c_idx < NETLBL_CATMAP_MAPCNT; c_idx++) {
170 unsigned int delta;
171 u64 map = c_iter->bitmap[c_idx];
172
173 if (!map)
174 continue;
175
176 c_pos = c_iter->startbit
177 + c_idx * NETLBL_CATMAP_MAPSIZE;
178 if (!e_iter
179 || c_pos >= e_iter->startbit + EBITMAP_SIZE) {
180 e_iter = kzalloc(sizeof(*e_iter), GFP_ATOMIC);
181 if (!e_iter)
182 goto netlbl_import_failure;
183 e_iter->startbit
184 = c_pos - (c_pos % EBITMAP_SIZE);
185 if (emap_prev == NULL)
186 ebmap->node = e_iter;
187 else
188 emap_prev->next = e_iter;
189 emap_prev = e_iter;
190 }
191 delta = c_pos - e_iter->startbit;
192 e_idx = delta / EBITMAP_UNIT_SIZE;
193 e_sft = delta % EBITMAP_UNIT_SIZE;
194 while (map) {
195 e_iter->maps[e_idx++] |= map & (-1UL);
196 map = EBITMAP_SHIFT_UNIT_SIZE(map);
197 }
198 }
199 c_iter = c_iter->next;
200 } while (c_iter);
201 if (e_iter != NULL)
202 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
203 else
204 ebitmap_destroy(ebmap);
205
206 return 0;
207
208 netlbl_import_failure:
209 ebitmap_destroy(ebmap);
210 return -ENOMEM;
211 }
212 #endif /* CONFIG_NETLABEL */
213
214 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
215 {
216 struct ebitmap_node *n1, *n2;
217 int i;
218
219 if (e1->highbit < e2->highbit)
220 return 0;
221
222 n1 = e1->node;
223 n2 = e2->node;
224 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
225 if (n1->startbit < n2->startbit) {
226 n1 = n1->next;
227 continue;
228 }
229 for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
230 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
231 return 0;
232 }
233
234 n1 = n1->next;
235 n2 = n2->next;
236 }
237
238 if (n2)
239 return 0;
240
241 return 1;
242 }
243
244 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
245 {
246 struct ebitmap_node *n;
247
248 if (e->highbit < bit)
249 return 0;
250
251 n = e->node;
252 while (n && (n->startbit <= bit)) {
253 if ((n->startbit + EBITMAP_SIZE) > bit)
254 return ebitmap_node_get_bit(n, bit);
255 n = n->next;
256 }
257
258 return 0;
259 }
260
261 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
262 {
263 struct ebitmap_node *n, *prev, *new;
264
265 prev = NULL;
266 n = e->node;
267 while (n && n->startbit <= bit) {
268 if ((n->startbit + EBITMAP_SIZE) > bit) {
269 if (value) {
270 ebitmap_node_set_bit(n, bit);
271 } else {
272 unsigned int s;
273
274 ebitmap_node_clr_bit(n, bit);
275
276 s = find_first_bit(n->maps, EBITMAP_SIZE);
277 if (s < EBITMAP_SIZE)
278 return 0;
279
280 /* drop this node from the bitmap */
281 if (!n->next) {
282 /*
283 * this was the highest map
284 * within the bitmap
285 */
286 if (prev)
287 e->highbit = prev->startbit
288 + EBITMAP_SIZE;
289 else
290 e->highbit = 0;
291 }
292 if (prev)
293 prev->next = n->next;
294 else
295 e->node = n->next;
296 kfree(n);
297 }
298 return 0;
299 }
300 prev = n;
301 n = n->next;
302 }
303
304 if (!value)
305 return 0;
306
307 new = kzalloc(sizeof(*new), GFP_ATOMIC);
308 if (!new)
309 return -ENOMEM;
310
311 new->startbit = bit - (bit % EBITMAP_SIZE);
312 ebitmap_node_set_bit(new, bit);
313
314 if (!n)
315 /* this node will be the highest map within the bitmap */
316 e->highbit = new->startbit + EBITMAP_SIZE;
317
318 if (prev) {
319 new->next = prev->next;
320 prev->next = new;
321 } else {
322 new->next = e->node;
323 e->node = new;
324 }
325
326 return 0;
327 }
328
329 void ebitmap_destroy(struct ebitmap *e)
330 {
331 struct ebitmap_node *n, *temp;
332
333 if (!e)
334 return;
335
336 n = e->node;
337 while (n) {
338 temp = n;
339 n = n->next;
340 kfree(temp);
341 }
342
343 e->highbit = 0;
344 e->node = NULL;
345 return;
346 }
347
348 int ebitmap_read(struct ebitmap *e, void *fp)
349 {
350 struct ebitmap_node *n = NULL;
351 u32 mapunit, count, startbit, index;
352 u64 map;
353 __le32 buf[3];
354 int rc, i;
355
356 ebitmap_init(e);
357
358 rc = next_entry(buf, fp, sizeof buf);
359 if (rc < 0)
360 goto out;
361
362 mapunit = le32_to_cpu(buf[0]);
363 e->highbit = le32_to_cpu(buf[1]);
364 count = le32_to_cpu(buf[2]);
365
366 if (mapunit != sizeof(u64) * 8) {
367 printk(KERN_ERR "SELinux: ebitmap: map size %u does not "
368 "match my size %Zd (high bit was %d)\n",
369 mapunit, sizeof(u64) * 8, e->highbit);
370 goto bad;
371 }
372
373 /* round up e->highbit */
374 e->highbit += EBITMAP_SIZE - 1;
375 e->highbit -= (e->highbit % EBITMAP_SIZE);
376
377 if (!e->highbit) {
378 e->node = NULL;
379 goto ok;
380 }
381
382 for (i = 0; i < count; i++) {
383 rc = next_entry(&startbit, fp, sizeof(u32));
384 if (rc < 0) {
385 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
386 goto bad;
387 }
388 startbit = le32_to_cpu(startbit);
389
390 if (startbit & (mapunit - 1)) {
391 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
392 "not a multiple of the map unit size (%u)\n",
393 startbit, mapunit);
394 goto bad;
395 }
396 if (startbit > e->highbit - mapunit) {
397 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
398 "beyond the end of the bitmap (%u)\n",
399 startbit, (e->highbit - mapunit));
400 goto bad;
401 }
402
403 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
404 struct ebitmap_node *tmp;
405 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
406 if (!tmp) {
407 printk(KERN_ERR
408 "SELinux: ebitmap: out of memory\n");
409 rc = -ENOMEM;
410 goto bad;
411 }
412 /* round down */
413 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
414 if (n)
415 n->next = tmp;
416 else
417 e->node = tmp;
418 n = tmp;
419 } else if (startbit <= n->startbit) {
420 printk(KERN_ERR "SELinux: ebitmap: start bit %d"
421 " comes after start bit %d\n",
422 startbit, n->startbit);
423 goto bad;
424 }
425
426 rc = next_entry(&map, fp, sizeof(u64));
427 if (rc < 0) {
428 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
429 goto bad;
430 }
431 map = le64_to_cpu(map);
432
433 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
434 while (map) {
435 n->maps[index++] = map & (-1UL);
436 map = EBITMAP_SHIFT_UNIT_SIZE(map);
437 }
438 }
439 ok:
440 rc = 0;
441 out:
442 return rc;
443 bad:
444 if (!rc)
445 rc = -EINVAL;
446 ebitmap_destroy(e);
447 goto out;
448 }
449
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