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31#include <linux/types.h>
32#include <linux/rcupdate.h>
33#include <linux/list.h>
34#include <linux/slab.h>
35#include <linux/spinlock.h>
36#include <linux/in.h>
37#include <linux/in6.h>
38#include <linux/ip.h>
39#include <linux/ipv6.h>
40#include <net/ip.h>
41#include <net/ipv6.h>
42
43#include "netnode.h"
44#include "objsec.h"
45
46#define SEL_NETNODE_HASH_SIZE 256
47#define SEL_NETNODE_HASH_BKT_LIMIT 16
48
49struct sel_netnode_bkt {
50 unsigned int size;
51 struct list_head list;
52};
53
54struct sel_netnode {
55 struct netnode_security_struct nsec;
56
57 struct list_head list;
58 struct rcu_head rcu;
59};
60
61
62
63
64
65
66
67static LIST_HEAD(sel_netnode_list);
68static DEFINE_SPINLOCK(sel_netnode_lock);
69static struct sel_netnode_bkt sel_netnode_hash[SEL_NETNODE_HASH_SIZE];
70
71
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78
79
80
81static void sel_netnode_free(struct rcu_head *p)
82{
83 struct sel_netnode *node = container_of(p, struct sel_netnode, rcu);
84 kfree(node);
85}
86
87
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93
94
95
96static unsigned int sel_netnode_hashfn_ipv4(__be32 addr)
97{
98
99
100 return (addr & (SEL_NETNODE_HASH_SIZE - 1));
101}
102
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110
111
112static unsigned int sel_netnode_hashfn_ipv6(const struct in6_addr *addr)
113{
114
115
116
117 return (addr->s6_addr32[3] & (SEL_NETNODE_HASH_SIZE - 1));
118}
119
120
121
122
123
124
125
126
127
128
129
130static struct sel_netnode *sel_netnode_find(const void *addr, u16 family)
131{
132 unsigned int idx;
133 struct sel_netnode *node;
134
135 switch (family) {
136 case PF_INET:
137 idx = sel_netnode_hashfn_ipv4(*(__be32 *)addr);
138 break;
139 case PF_INET6:
140 idx = sel_netnode_hashfn_ipv6(addr);
141 break;
142 default:
143 BUG();
144 }
145
146 list_for_each_entry_rcu(node, &sel_netnode_hash[idx].list, list)
147 if (node->nsec.family == family)
148 switch (family) {
149 case PF_INET:
150 if (node->nsec.addr.ipv4 == *(__be32 *)addr)
151 return node;
152 break;
153 case PF_INET6:
154 if (ipv6_addr_equal(&node->nsec.addr.ipv6,
155 addr))
156 return node;
157 break;
158 }
159
160 return NULL;
161}
162
163
164
165
166
167
168
169
170
171static void sel_netnode_insert(struct sel_netnode *node)
172{
173 unsigned int idx;
174
175 switch (node->nsec.family) {
176 case PF_INET:
177 idx = sel_netnode_hashfn_ipv4(node->nsec.addr.ipv4);
178 break;
179 case PF_INET6:
180 idx = sel_netnode_hashfn_ipv6(&node->nsec.addr.ipv6);
181 break;
182 default:
183 BUG();
184 }
185
186
187
188 list_add_rcu(&node->list, &sel_netnode_hash[idx].list);
189 if (sel_netnode_hash[idx].size == SEL_NETNODE_HASH_BKT_LIMIT) {
190 struct sel_netnode *tail;
191 tail = list_entry(
192 rcu_dereference(sel_netnode_hash[idx].list.prev),
193 struct sel_netnode, list);
194 list_del_rcu(&tail->list);
195 call_rcu(&tail->rcu, sel_netnode_free);
196 } else
197 sel_netnode_hash[idx].size++;
198}
199
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211
212
213static int sel_netnode_sid_slow(void *addr, u16 family, u32 *sid)
214{
215 int ret = -ENOMEM;
216 struct sel_netnode *node;
217 struct sel_netnode *new = NULL;
218
219 spin_lock_bh(&sel_netnode_lock);
220 node = sel_netnode_find(addr, family);
221 if (node != NULL) {
222 *sid = node->nsec.sid;
223 spin_unlock_bh(&sel_netnode_lock);
224 return 0;
225 }
226 new = kzalloc(sizeof(*new), GFP_ATOMIC);
227 if (new == NULL)
228 goto out;
229 switch (family) {
230 case PF_INET:
231 ret = security_node_sid(PF_INET,
232 addr, sizeof(struct in_addr), sid);
233 new->nsec.addr.ipv4 = *(__be32 *)addr;
234 break;
235 case PF_INET6:
236 ret = security_node_sid(PF_INET6,
237 addr, sizeof(struct in6_addr), sid);
238 ipv6_addr_copy(&new->nsec.addr.ipv6, addr);
239 break;
240 default:
241 BUG();
242 }
243 if (ret != 0)
244 goto out;
245
246 new->nsec.family = family;
247 new->nsec.sid = *sid;
248 sel_netnode_insert(new);
249
250out:
251 spin_unlock_bh(&sel_netnode_lock);
252 if (unlikely(ret)) {
253 printk(KERN_WARNING
254 "SELinux: failure in sel_netnode_sid_slow(),"
255 " unable to determine network node label\n");
256 kfree(new);
257 }
258 return ret;
259}
260
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273
274
275int sel_netnode_sid(void *addr, u16 family, u32 *sid)
276{
277 struct sel_netnode *node;
278
279 rcu_read_lock();
280 node = sel_netnode_find(addr, family);
281 if (node != NULL) {
282 *sid = node->nsec.sid;
283 rcu_read_unlock();
284 return 0;
285 }
286 rcu_read_unlock();
287
288 return sel_netnode_sid_slow(addr, family, sid);
289}
290
291
292
293
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295
296
297
298static void sel_netnode_flush(void)
299{
300 unsigned int idx;
301 struct sel_netnode *node, *node_tmp;
302
303 spin_lock_bh(&sel_netnode_lock);
304 for (idx = 0; idx < SEL_NETNODE_HASH_SIZE; idx++) {
305 list_for_each_entry_safe(node, node_tmp,
306 &sel_netnode_hash[idx].list, list) {
307 list_del_rcu(&node->list);
308 call_rcu(&node->rcu, sel_netnode_free);
309 }
310 sel_netnode_hash[idx].size = 0;
311 }
312 spin_unlock_bh(&sel_netnode_lock);
313}
314
315static int sel_netnode_avc_callback(u32 event, u32 ssid, u32 tsid,
316 u16 class, u32 perms, u32 *retained)
317{
318 if (event == AVC_CALLBACK_RESET) {
319 sel_netnode_flush();
320 synchronize_net();
321 }
322 return 0;
323}
324
325static __init int sel_netnode_init(void)
326{
327 int iter;
328 int ret;
329
330 if (!selinux_enabled)
331 return 0;
332
333 for (iter = 0; iter < SEL_NETNODE_HASH_SIZE; iter++) {
334 INIT_LIST_HEAD(&sel_netnode_hash[iter].list);
335 sel_netnode_hash[iter].size = 0;
336 }
337
338 ret = avc_add_callback(sel_netnode_avc_callback, AVC_CALLBACK_RESET,
339 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
340 if (ret != 0)
341 panic("avc_add_callback() failed, error %d\n", ret);
342
343 return ret;
344}
345
346__initcall(sel_netnode_init);
347