[PATCH] SELinux: convert to kzalloc
[linux-3.10.git] / security / selinux / ss / ebitmap.c
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
12 int 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
34 int 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 = kzalloc(sizeof(*new), GFP_ATOMIC);
43                 if (!new) {
44                         ebitmap_destroy(dst);
45                         return -ENOMEM;
46                 }
47                 new->startbit = n->startbit;
48                 new->map = n->map;
49                 new->next = NULL;
50                 if (prev)
51                         prev->next = new;
52                 else
53                         dst->node = new;
54                 prev = new;
55                 n = n->next;
56         }
57
58         dst->highbit = src->highbit;
59         return 0;
60 }
61
62 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
63 {
64         struct ebitmap_node *n1, *n2;
65
66         if (e1->highbit < e2->highbit)
67                 return 0;
68
69         n1 = e1->node;
70         n2 = e2->node;
71         while (n1 && n2 && (n1->startbit <= n2->startbit)) {
72                 if (n1->startbit < n2->startbit) {
73                         n1 = n1->next;
74                         continue;
75                 }
76                 if ((n1->map & n2->map) != n2->map)
77                         return 0;
78
79                 n1 = n1->next;
80                 n2 = n2->next;
81         }
82
83         if (n2)
84                 return 0;
85
86         return 1;
87 }
88
89 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
90 {
91         struct ebitmap_node *n;
92
93         if (e->highbit < bit)
94                 return 0;
95
96         n = e->node;
97         while (n && (n->startbit <= bit)) {
98                 if ((n->startbit + MAPSIZE) > bit) {
99                         if (n->map & (MAPBIT << (bit - n->startbit)))
100                                 return 1;
101                         else
102                                 return 0;
103                 }
104                 n = n->next;
105         }
106
107         return 0;
108 }
109
110 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
111 {
112         struct ebitmap_node *n, *prev, *new;
113
114         prev = NULL;
115         n = e->node;
116         while (n && n->startbit <= bit) {
117                 if ((n->startbit + MAPSIZE) > bit) {
118                         if (value) {
119                                 n->map |= (MAPBIT << (bit - n->startbit));
120                         } else {
121                                 n->map &= ~(MAPBIT << (bit - n->startbit));
122                                 if (!n->map) {
123                                         /* drop this node from the bitmap */
124
125                                         if (!n->next) {
126                                                 /*
127                                                  * this was the highest map
128                                                  * within the bitmap
129                                                  */
130                                                 if (prev)
131                                                         e->highbit = prev->startbit + MAPSIZE;
132                                                 else
133                                                         e->highbit = 0;
134                                         }
135                                         if (prev)
136                                                 prev->next = n->next;
137                                         else
138                                                 e->node = n->next;
139
140                                         kfree(n);
141                                 }
142                         }
143                         return 0;
144                 }
145                 prev = n;
146                 n = n->next;
147         }
148
149         if (!value)
150                 return 0;
151
152         new = kzalloc(sizeof(*new), GFP_ATOMIC);
153         if (!new)
154                 return -ENOMEM;
155
156         new->startbit = bit & ~(MAPSIZE - 1);
157         new->map = (MAPBIT << (bit - new->startbit));
158
159         if (!n)
160                 /* this node will be the highest map within the bitmap */
161                 e->highbit = new->startbit + MAPSIZE;
162
163         if (prev) {
164                 new->next = prev->next;
165                 prev->next = new;
166         } else {
167                 new->next = e->node;
168                 e->node = new;
169         }
170
171         return 0;
172 }
173
174 void ebitmap_destroy(struct ebitmap *e)
175 {
176         struct ebitmap_node *n, *temp;
177
178         if (!e)
179                 return;
180
181         n = e->node;
182         while (n) {
183                 temp = n;
184                 n = n->next;
185                 kfree(temp);
186         }
187
188         e->highbit = 0;
189         e->node = NULL;
190         return;
191 }
192
193 int ebitmap_read(struct ebitmap *e, void *fp)
194 {
195         int rc;
196         struct ebitmap_node *n, *l;
197         __le32 buf[3];
198         u32 mapsize, count, i;
199         __le64 map;
200
201         ebitmap_init(e);
202
203         rc = next_entry(buf, fp, sizeof buf);
204         if (rc < 0)
205                 goto out;
206
207         mapsize = le32_to_cpu(buf[0]);
208         e->highbit = le32_to_cpu(buf[1]);
209         count = le32_to_cpu(buf[2]);
210
211         if (mapsize != MAPSIZE) {
212                 printk(KERN_ERR "security: ebitmap: map size %u does not "
213                        "match my size %Zd (high bit was %d)\n", mapsize,
214                        MAPSIZE, e->highbit);
215                 goto bad;
216         }
217         if (!e->highbit) {
218                 e->node = NULL;
219                 goto ok;
220         }
221         if (e->highbit & (MAPSIZE - 1)) {
222                 printk(KERN_ERR "security: ebitmap: high bit (%d) is not a "
223                        "multiple of the map size (%Zd)\n", e->highbit, MAPSIZE);
224                 goto bad;
225         }
226         l = NULL;
227         for (i = 0; i < count; i++) {
228                 rc = next_entry(buf, fp, sizeof(u32));
229                 if (rc < 0) {
230                         printk(KERN_ERR "security: ebitmap: truncated map\n");
231                         goto bad;
232                 }
233                 n = kzalloc(sizeof(*n), GFP_KERNEL);
234                 if (!n) {
235                         printk(KERN_ERR "security: ebitmap: out of memory\n");
236                         rc = -ENOMEM;
237                         goto bad;
238                 }
239
240                 n->startbit = le32_to_cpu(buf[0]);
241
242                 if (n->startbit & (MAPSIZE - 1)) {
243                         printk(KERN_ERR "security: ebitmap start bit (%d) is "
244                                "not a multiple of the map size (%Zd)\n",
245                                n->startbit, MAPSIZE);
246                         goto bad_free;
247                 }
248                 if (n->startbit > (e->highbit - MAPSIZE)) {
249                         printk(KERN_ERR "security: ebitmap start bit (%d) is "
250                                "beyond the end of the bitmap (%Zd)\n",
251                                n->startbit, (e->highbit - MAPSIZE));
252                         goto bad_free;
253                 }
254                 rc = next_entry(&map, fp, sizeof(u64));
255                 if (rc < 0) {
256                         printk(KERN_ERR "security: ebitmap: truncated map\n");
257                         goto bad_free;
258                 }
259                 n->map = le64_to_cpu(map);
260
261                 if (!n->map) {
262                         printk(KERN_ERR "security: ebitmap: null map in "
263                                "ebitmap (startbit %d)\n", n->startbit);
264                         goto bad_free;
265                 }
266                 if (l) {
267                         if (n->startbit <= l->startbit) {
268                                 printk(KERN_ERR "security: ebitmap: start "
269                                        "bit %d comes after start bit %d\n",
270                                        n->startbit, l->startbit);
271                                 goto bad_free;
272                         }
273                         l->next = n;
274                 } else
275                         e->node = n;
276
277                 l = n;
278         }
279
280 ok:
281         rc = 0;
282 out:
283         return rc;
284 bad_free:
285         kfree(n);
286 bad:
287         if (!rc)
288                 rc = -EINVAL;
289         ebitmap_destroy(e);
290         goto out;
291 }