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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /security/selinux/ss/sidtab.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'security/selinux/ss/sidtab.c')
-rw-r--r--security/selinux/ss/sidtab.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
new file mode 100644
index 000000000000..871c33bd0741
--- /dev/null
+++ b/security/selinux/ss/sidtab.c
@@ -0,0 +1,305 @@
1/*
2 * Implementation of the SID table type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6#include <linux/kernel.h>
7#include <linux/slab.h>
8#include <linux/spinlock.h>
9#include <linux/errno.h>
10#include <linux/sched.h>
11#include "flask.h"
12#include "security.h"
13#include "sidtab.h"
14
15#define SIDTAB_HASH(sid) \
16(sid & SIDTAB_HASH_MASK)
17
18#define INIT_SIDTAB_LOCK(s) spin_lock_init(&s->lock)
19#define SIDTAB_LOCK(s, x) spin_lock_irqsave(&s->lock, x)
20#define SIDTAB_UNLOCK(s, x) spin_unlock_irqrestore(&s->lock, x)
21
22int sidtab_init(struct sidtab *s)
23{
24 int i;
25
26 s->htable = kmalloc(sizeof(*(s->htable)) * SIDTAB_SIZE, GFP_ATOMIC);
27 if (!s->htable)
28 return -ENOMEM;
29 for (i = 0; i < SIDTAB_SIZE; i++)
30 s->htable[i] = NULL;
31 s->nel = 0;
32 s->next_sid = 1;
33 s->shutdown = 0;
34 INIT_SIDTAB_LOCK(s);
35 return 0;
36}
37
38int sidtab_insert(struct sidtab *s, u32 sid, struct context *context)
39{
40 int hvalue, rc = 0;
41 struct sidtab_node *prev, *cur, *newnode;
42
43 if (!s) {
44 rc = -ENOMEM;
45 goto out;
46 }
47
48 hvalue = SIDTAB_HASH(sid);
49 prev = NULL;
50 cur = s->htable[hvalue];
51 while (cur != NULL && sid > cur->sid) {
52 prev = cur;
53 cur = cur->next;
54 }
55
56 if (cur && sid == cur->sid) {
57 rc = -EEXIST;
58 goto out;
59 }
60
61 newnode = kmalloc(sizeof(*newnode), GFP_ATOMIC);
62 if (newnode == NULL) {
63 rc = -ENOMEM;
64 goto out;
65 }
66 newnode->sid = sid;
67 if (context_cpy(&newnode->context, context)) {
68 kfree(newnode);
69 rc = -ENOMEM;
70 goto out;
71 }
72
73 if (prev) {
74 newnode->next = prev->next;
75 wmb();
76 prev->next = newnode;
77 } else {
78 newnode->next = s->htable[hvalue];
79 wmb();
80 s->htable[hvalue] = newnode;
81 }
82
83 s->nel++;
84 if (sid >= s->next_sid)
85 s->next_sid = sid + 1;
86out:
87 return rc;
88}
89
90struct context *sidtab_search(struct sidtab *s, u32 sid)
91{
92 int hvalue;
93 struct sidtab_node *cur;
94
95 if (!s)
96 return NULL;
97
98 hvalue = SIDTAB_HASH(sid);
99 cur = s->htable[hvalue];
100 while (cur != NULL && sid > cur->sid)
101 cur = cur->next;
102
103 if (cur == NULL || sid != cur->sid) {
104 /* Remap invalid SIDs to the unlabeled SID. */
105 sid = SECINITSID_UNLABELED;
106 hvalue = SIDTAB_HASH(sid);
107 cur = s->htable[hvalue];
108 while (cur != NULL && sid > cur->sid)
109 cur = cur->next;
110 if (!cur || sid != cur->sid)
111 return NULL;
112 }
113
114 return &cur->context;
115}
116
117int sidtab_map(struct sidtab *s,
118 int (*apply) (u32 sid,
119 struct context *context,
120 void *args),
121 void *args)
122{
123 int i, rc = 0;
124 struct sidtab_node *cur;
125
126 if (!s)
127 goto out;
128
129 for (i = 0; i < SIDTAB_SIZE; i++) {
130 cur = s->htable[i];
131 while (cur != NULL) {
132 rc = apply(cur->sid, &cur->context, args);
133 if (rc)
134 goto out;
135 cur = cur->next;
136 }
137 }
138out:
139 return rc;
140}
141
142void sidtab_map_remove_on_error(struct sidtab *s,
143 int (*apply) (u32 sid,
144 struct context *context,
145 void *args),
146 void *args)
147{
148 int i, ret;
149 struct sidtab_node *last, *cur, *temp;
150
151 if (!s)
152 return;
153
154 for (i = 0; i < SIDTAB_SIZE; i++) {
155 last = NULL;
156 cur = s->htable[i];
157 while (cur != NULL) {
158 ret = apply(cur->sid, &cur->context, args);
159 if (ret) {
160 if (last) {
161 last->next = cur->next;
162 } else {
163 s->htable[i] = cur->next;
164 }
165
166 temp = cur;
167 cur = cur->next;
168 context_destroy(&temp->context);
169 kfree(temp);
170 s->nel--;
171 } else {
172 last = cur;
173 cur = cur->next;
174 }
175 }
176 }
177
178 return;
179}
180
181static inline u32 sidtab_search_context(struct sidtab *s,
182 struct context *context)
183{
184 int i;
185 struct sidtab_node *cur;
186
187 for (i = 0; i < SIDTAB_SIZE; i++) {
188 cur = s->htable[i];
189 while (cur != NULL) {
190 if (context_cmp(&cur->context, context))
191 return cur->sid;
192 cur = cur->next;
193 }
194 }
195 return 0;
196}
197
198int sidtab_context_to_sid(struct sidtab *s,
199 struct context *context,
200 u32 *out_sid)
201{
202 u32 sid;
203 int ret = 0;
204 unsigned long flags;
205
206 *out_sid = SECSID_NULL;
207
208 sid = sidtab_search_context(s, context);
209 if (!sid) {
210 SIDTAB_LOCK(s, flags);
211 /* Rescan now that we hold the lock. */
212 sid = sidtab_search_context(s, context);
213 if (sid)
214 goto unlock_out;
215 /* No SID exists for the context. Allocate a new one. */
216 if (s->next_sid == UINT_MAX || s->shutdown) {
217 ret = -ENOMEM;
218 goto unlock_out;
219 }
220 sid = s->next_sid++;
221 ret = sidtab_insert(s, sid, context);
222 if (ret)
223 s->next_sid--;
224unlock_out:
225 SIDTAB_UNLOCK(s, flags);
226 }
227
228 if (ret)
229 return ret;
230
231 *out_sid = sid;
232 return 0;
233}
234
235void sidtab_hash_eval(struct sidtab *h, char *tag)
236{
237 int i, chain_len, slots_used, max_chain_len;
238 struct sidtab_node *cur;
239
240 slots_used = 0;
241 max_chain_len = 0;
242 for (i = 0; i < SIDTAB_SIZE; i++) {
243 cur = h->htable[i];
244 if (cur) {
245 slots_used++;
246 chain_len = 0;
247 while (cur) {
248 chain_len++;
249 cur = cur->next;
250 }
251
252 if (chain_len > max_chain_len)
253 max_chain_len = chain_len;
254 }
255 }
256
257 printk(KERN_INFO "%s: %d entries and %d/%d buckets used, longest "
258 "chain length %d\n", tag, h->nel, slots_used, SIDTAB_SIZE,
259 max_chain_len);
260}
261
262void sidtab_destroy(struct sidtab *s)
263{
264 int i;
265 struct sidtab_node *cur, *temp;
266
267 if (!s)
268 return;
269
270 for (i = 0; i < SIDTAB_SIZE; i++) {
271 cur = s->htable[i];
272 while (cur != NULL) {
273 temp = cur;
274 cur = cur->next;
275 context_destroy(&temp->context);
276 kfree(temp);
277 }
278 s->htable[i] = NULL;
279 }
280 kfree(s->htable);
281 s->htable = NULL;
282 s->nel = 0;
283 s->next_sid = 1;
284}
285
286void sidtab_set(struct sidtab *dst, struct sidtab *src)
287{
288 unsigned long flags;
289
290 SIDTAB_LOCK(src, flags);
291 dst->htable = src->htable;
292 dst->nel = src->nel;
293 dst->next_sid = src->next_sid;
294 dst->shutdown = 0;
295 SIDTAB_UNLOCK(src, flags);
296}
297
298void sidtab_shutdown(struct sidtab *s)
299{
300 unsigned long flags;
301
302 SIDTAB_LOCK(s, flags);
303 s->shutdown = 1;
304 SIDTAB_UNLOCK(s, flags);
305}