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-rw-r--r--security/selinux/ss/ebitmap.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
new file mode 100644
index 000000000000..d8ce9cc0b9f1
--- /dev/null
+++ b/security/selinux/ss/ebitmap.c
@@ -0,0 +1,293 @@
1/*
2 * Implementation of the extensible bitmap type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6#include <linux/kernel.h>
7#include <linux/slab.h>
8#include <linux/errno.h>
9#include "ebitmap.h"
10#include "policydb.h"
11
12int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
13{
14 struct ebitmap_node *n1, *n2;
15
16 if (e1->highbit != e2->highbit)
17 return 0;
18
19 n1 = e1->node;
20 n2 = e2->node;
21 while (n1 && n2 &&
22 (n1->startbit == n2->startbit) &&
23 (n1->map == n2->map)) {
24 n1 = n1->next;
25 n2 = n2->next;
26 }
27
28 if (n1 || n2)
29 return 0;
30
31 return 1;
32}
33
34int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
35{
36 struct ebitmap_node *n, *new, *prev;
37
38 ebitmap_init(dst);
39 n = src->node;
40 prev = NULL;
41 while (n) {
42 new = kmalloc(sizeof(*new), GFP_ATOMIC);
43 if (!new) {
44 ebitmap_destroy(dst);
45 return -ENOMEM;
46 }
47 memset(new, 0, sizeof(*new));
48 new->startbit = n->startbit;
49 new->map = n->map;
50 new->next = NULL;
51 if (prev)
52 prev->next = new;
53 else
54 dst->node = new;
55 prev = new;
56 n = n->next;
57 }
58
59 dst->highbit = src->highbit;
60 return 0;
61}
62
63int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
64{
65 struct ebitmap_node *n1, *n2;
66
67 if (e1->highbit < e2->highbit)
68 return 0;
69
70 n1 = e1->node;
71 n2 = e2->node;
72 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
73 if (n1->startbit < n2->startbit) {
74 n1 = n1->next;
75 continue;
76 }
77 if ((n1->map & n2->map) != n2->map)
78 return 0;
79
80 n1 = n1->next;
81 n2 = n2->next;
82 }
83
84 if (n2)
85 return 0;
86
87 return 1;
88}
89
90int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
91{
92 struct ebitmap_node *n;
93
94 if (e->highbit < bit)
95 return 0;
96
97 n = e->node;
98 while (n && (n->startbit <= bit)) {
99 if ((n->startbit + MAPSIZE) > bit) {
100 if (n->map & (MAPBIT << (bit - n->startbit)))
101 return 1;
102 else
103 return 0;
104 }
105 n = n->next;
106 }
107
108 return 0;
109}
110
111int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
112{
113 struct ebitmap_node *n, *prev, *new;
114
115 prev = NULL;
116 n = e->node;
117 while (n && n->startbit <= bit) {
118 if ((n->startbit + MAPSIZE) > bit) {
119 if (value) {
120 n->map |= (MAPBIT << (bit - n->startbit));
121 } else {
122 n->map &= ~(MAPBIT << (bit - n->startbit));
123 if (!n->map) {
124 /* drop this node from the bitmap */
125
126 if (!n->next) {
127 /*
128 * this was the highest map
129 * within the bitmap
130 */
131 if (prev)
132 e->highbit = prev->startbit + MAPSIZE;
133 else
134 e->highbit = 0;
135 }
136 if (prev)
137 prev->next = n->next;
138 else
139 e->node = n->next;
140
141 kfree(n);
142 }
143 }
144 return 0;
145 }
146 prev = n;
147 n = n->next;
148 }
149
150 if (!value)
151 return 0;
152
153 new = kmalloc(sizeof(*new), GFP_ATOMIC);
154 if (!new)
155 return -ENOMEM;
156 memset(new, 0, sizeof(*new));
157
158 new->startbit = bit & ~(MAPSIZE - 1);
159 new->map = (MAPBIT << (bit - new->startbit));
160
161 if (!n)
162 /* this node will be the highest map within the bitmap */
163 e->highbit = new->startbit + MAPSIZE;
164
165 if (prev) {
166 new->next = prev->next;
167 prev->next = new;
168 } else {
169 new->next = e->node;
170 e->node = new;
171 }
172
173 return 0;
174}
175
176void ebitmap_destroy(struct ebitmap *e)
177{
178 struct ebitmap_node *n, *temp;
179
180 if (!e)
181 return;
182
183 n = e->node;
184 while (n) {
185 temp = n;
186 n = n->next;
187 kfree(temp);
188 }
189
190 e->highbit = 0;
191 e->node = NULL;
192 return;
193}
194
195int ebitmap_read(struct ebitmap *e, void *fp)
196{
197 int rc;
198 struct ebitmap_node *n, *l;
199 u32 buf[3], mapsize, count, i;
200 u64 map;
201
202 ebitmap_init(e);
203
204 rc = next_entry(buf, fp, sizeof buf);
205 if (rc < 0)
206 goto out;
207
208 mapsize = le32_to_cpu(buf[0]);
209 e->highbit = le32_to_cpu(buf[1]);
210 count = le32_to_cpu(buf[2]);
211
212 if (mapsize != MAPSIZE) {
213 printk(KERN_ERR "security: ebitmap: map size %u does not "
214 "match my size %Zd (high bit was %d)\n", mapsize,
215 MAPSIZE, e->highbit);
216 goto bad;
217 }
218 if (!e->highbit) {
219 e->node = NULL;
220 goto ok;
221 }
222 if (e->highbit & (MAPSIZE - 1)) {
223 printk(KERN_ERR "security: ebitmap: high bit (%d) is not a "
224 "multiple of the map size (%Zd)\n", e->highbit, MAPSIZE);
225 goto bad;
226 }
227 l = NULL;
228 for (i = 0; i < count; i++) {
229 rc = next_entry(buf, fp, sizeof(u32));
230 if (rc < 0) {
231 printk(KERN_ERR "security: ebitmap: truncated map\n");
232 goto bad;
233 }
234 n = kmalloc(sizeof(*n), GFP_KERNEL);
235 if (!n) {
236 printk(KERN_ERR "security: ebitmap: out of memory\n");
237 rc = -ENOMEM;
238 goto bad;
239 }
240 memset(n, 0, sizeof(*n));
241
242 n->startbit = le32_to_cpu(buf[0]);
243
244 if (n->startbit & (MAPSIZE - 1)) {
245 printk(KERN_ERR "security: ebitmap start bit (%d) is "
246 "not a multiple of the map size (%Zd)\n",
247 n->startbit, MAPSIZE);
248 goto bad_free;
249 }
250 if (n->startbit > (e->highbit - MAPSIZE)) {
251 printk(KERN_ERR "security: ebitmap start bit (%d) is "
252 "beyond the end of the bitmap (%Zd)\n",
253 n->startbit, (e->highbit - MAPSIZE));
254 goto bad_free;
255 }
256 rc = next_entry(&map, fp, sizeof(u64));
257 if (rc < 0) {
258 printk(KERN_ERR "security: ebitmap: truncated map\n");
259 goto bad_free;
260 }
261 n->map = le64_to_cpu(map);
262
263 if (!n->map) {
264 printk(KERN_ERR "security: ebitmap: null map in "
265 "ebitmap (startbit %d)\n", n->startbit);
266 goto bad_free;
267 }
268 if (l) {
269 if (n->startbit <= l->startbit) {
270 printk(KERN_ERR "security: ebitmap: start "
271 "bit %d comes after start bit %d\n",
272 n->startbit, l->startbit);
273 goto bad_free;
274 }
275 l->next = n;
276 } else
277 e->node = n;
278
279 l = n;
280 }
281
282ok:
283 rc = 0;
284out:
285 return rc;
286bad_free:
287 kfree(n);
288bad:
289 if (!rc)
290 rc = -EINVAL;
291 ebitmap_destroy(e);
292 goto out;
293}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-23 05:27:53 -0500