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14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/slab.h>
17#include <linux/stddef.h>
18#include <linux/kernel.h>
19#include <linux/list.h>
20#include <linux/notifier.h>
21#include <linux/netdevice.h>
22#include <linux/rcupdate.h>
23#include <net/net_namespace.h>
24
25#include "security.h"
26#include "objsec.h"
27#include "netif.h"
28
29#define SEL_NETIF_HASH_SIZE 64
30#define SEL_NETIF_HASH_MAX 1024
31
32struct sel_netif {
33 struct list_head list;
34 struct netif_security_struct nsec;
35 struct rcu_head rcu_head;
36};
37
38static u32 sel_netif_total;
39static DEFINE_SPINLOCK(sel_netif_lock);
40static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE];
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52static inline u32 sel_netif_hashfn(const struct net *ns, int ifindex)
53{
54 return (((uintptr_t)ns + ifindex) & (SEL_NETIF_HASH_SIZE - 1));
55}
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66
67static inline struct sel_netif *sel_netif_find(const struct net *ns,
68 int ifindex)
69{
70 int idx = sel_netif_hashfn(ns, ifindex);
71 struct sel_netif *netif;
72
73 list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list)
74 if (net_eq(netif->nsec.ns, ns) &&
75 netif->nsec.ifindex == ifindex)
76 return netif;
77
78 return NULL;
79}
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89
90static int sel_netif_insert(struct sel_netif *netif)
91{
92 int idx;
93
94 if (sel_netif_total >= SEL_NETIF_HASH_MAX)
95 return -ENOSPC;
96
97 idx = sel_netif_hashfn(netif->nsec.ns, netif->nsec.ifindex);
98 list_add_rcu(&netif->list, &sel_netif_hash[idx]);
99 sel_netif_total++;
100
101 return 0;
102}
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111
112static void sel_netif_destroy(struct sel_netif *netif)
113{
114 list_del_rcu(&netif->list);
115 sel_netif_total--;
116 kfree_rcu(netif, rcu_head);
117}
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131
132static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid)
133{
134 int ret = 0;
135 struct sel_netif *netif;
136 struct sel_netif *new;
137 struct net_device *dev;
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142 dev = dev_get_by_index(ns, ifindex);
143 if (unlikely(dev == NULL)) {
144 pr_warn("SELinux: failure in %s(), invalid network interface (%d)\n",
145 __func__, ifindex);
146 return -ENOENT;
147 }
148
149 spin_lock_bh(&sel_netif_lock);
150 netif = sel_netif_find(ns, ifindex);
151 if (netif != NULL) {
152 *sid = netif->nsec.sid;
153 goto out;
154 }
155
156 ret = security_netif_sid(&selinux_state, dev->name, sid);
157 if (ret != 0)
158 goto out;
159 new = kzalloc(sizeof(*new), GFP_ATOMIC);
160 if (new) {
161 new->nsec.ns = ns;
162 new->nsec.ifindex = ifindex;
163 new->nsec.sid = *sid;
164 if (sel_netif_insert(new))
165 kfree(new);
166 }
167
168out:
169 spin_unlock_bh(&sel_netif_lock);
170 dev_put(dev);
171 if (unlikely(ret))
172 pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n",
173 __func__, ifindex);
174 return ret;
175}
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191int sel_netif_sid(struct net *ns, int ifindex, u32 *sid)
192{
193 struct sel_netif *netif;
194
195 rcu_read_lock();
196 netif = sel_netif_find(ns, ifindex);
197 if (likely(netif != NULL)) {
198 *sid = netif->nsec.sid;
199 rcu_read_unlock();
200 return 0;
201 }
202 rcu_read_unlock();
203
204 return sel_netif_sid_slow(ns, ifindex, sid);
205}
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216
217static void sel_netif_kill(const struct net *ns, int ifindex)
218{
219 struct sel_netif *netif;
220
221 rcu_read_lock();
222 spin_lock_bh(&sel_netif_lock);
223 netif = sel_netif_find(ns, ifindex);
224 if (netif)
225 sel_netif_destroy(netif);
226 spin_unlock_bh(&sel_netif_lock);
227 rcu_read_unlock();
228}
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237void sel_netif_flush(void)
238{
239 int idx;
240 struct sel_netif *netif;
241
242 spin_lock_bh(&sel_netif_lock);
243 for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++)
244 list_for_each_entry(netif, &sel_netif_hash[idx], list)
245 sel_netif_destroy(netif);
246 spin_unlock_bh(&sel_netif_lock);
247}
248
249static int sel_netif_netdev_notifier_handler(struct notifier_block *this,
250 unsigned long event, void *ptr)
251{
252 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
253
254 if (event == NETDEV_DOWN)
255 sel_netif_kill(dev_net(dev), dev->ifindex);
256
257 return NOTIFY_DONE;
258}
259
260static struct notifier_block sel_netif_netdev_notifier = {
261 .notifier_call = sel_netif_netdev_notifier_handler,
262};
263
264static __init int sel_netif_init(void)
265{
266 int i;
267
268 if (!selinux_enabled_boot)
269 return 0;
270
271 for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)
272 INIT_LIST_HEAD(&sel_netif_hash[i]);
273
274 register_netdevice_notifier(&sel_netif_netdev_notifier);
275
276 return 0;
277}
278
279__initcall(sel_netif_init);
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