1
2
3
4
5
6
7
8
9
10
11
12
13
14
15#include <linux/init.h>
16#include <linux/types.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
32#undef DEBUG
33
34#ifdef DEBUG
35#define DEBUGP printk
36#else
37#define DEBUGP(format, args...)
38#endif
39
40struct sel_netif
41{
42 struct list_head list;
43 struct netif_security_struct nsec;
44 struct rcu_head rcu_head;
45};
46
47static u32 sel_netif_total;
48static LIST_HEAD(sel_netif_list);
49static DEFINE_SPINLOCK(sel_netif_lock);
50static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE];
51
52static inline u32 sel_netif_hasfn(struct net_device *dev)
53{
54 return (dev->ifindex & (SEL_NETIF_HASH_SIZE - 1));
55}
56
57
58
59
60
61static inline struct sel_netif *sel_netif_find(struct net_device *dev)
62{
63 struct list_head *pos;
64 int idx = sel_netif_hasfn(dev);
65
66 __list_for_each_rcu(pos, &sel_netif_hash[idx]) {
67 struct sel_netif *netif = list_entry(pos,
68 struct sel_netif, list);
69 if (likely(netif->nsec.dev == dev))
70 return netif;
71 }
72 return NULL;
73}
74
75static int sel_netif_insert(struct sel_netif *netif)
76{
77 int idx, ret = 0;
78
79 if (sel_netif_total >= SEL_NETIF_HASH_MAX) {
80 ret = -ENOSPC;
81 goto out;
82 }
83
84 idx = sel_netif_hasfn(netif->nsec.dev);
85 list_add_rcu(&netif->list, &sel_netif_hash[idx]);
86 sel_netif_total++;
87out:
88 return ret;
89}
90
91static void sel_netif_free(struct rcu_head *p)
92{
93 struct sel_netif *netif = container_of(p, struct sel_netif, rcu_head);
94
95 DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);
96 kfree(netif);
97}
98
99static void sel_netif_destroy(struct sel_netif *netif)
100{
101 DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);
102
103 list_del_rcu(&netif->list);
104 sel_netif_total--;
105 call_rcu(&netif->rcu_head, sel_netif_free);
106}
107
108static struct sel_netif *sel_netif_lookup(struct net_device *dev)
109{
110 int ret;
111 struct sel_netif *netif, *new;
112 struct netif_security_struct *nsec;
113
114 netif = sel_netif_find(dev);
115 if (likely(netif != NULL))
116 goto out;
117
118 new = kzalloc(sizeof(*new), GFP_ATOMIC);
119 if (!new) {
120 netif = ERR_PTR(-ENOMEM);
121 goto out;
122 }
123
124 nsec = &new->nsec;
125
126 ret = security_netif_sid(dev->name, &nsec->if_sid, &nsec->msg_sid);
127 if (ret < 0) {
128 kfree(new);
129 netif = ERR_PTR(ret);
130 goto out;
131 }
132
133 nsec->dev = dev;
134
135 spin_lock_bh(&sel_netif_lock);
136
137 netif = sel_netif_find(dev);
138 if (netif) {
139 spin_unlock_bh(&sel_netif_lock);
140 kfree(new);
141 goto out;
142 }
143
144 ret = sel_netif_insert(new);
145 spin_unlock_bh(&sel_netif_lock);
146
147 if (ret) {
148 kfree(new);
149 netif = ERR_PTR(ret);
150 goto out;
151 }
152
153 netif = new;
154
155 DEBUGP("new: ifindex=%u name=%s if_sid=%u msg_sid=%u\n", dev->ifindex, dev->name,
156 nsec->if_sid, nsec->msg_sid);
157out:
158 return netif;
159}
160
161static void sel_netif_assign_sids(u32 if_sid_in, u32 msg_sid_in, u32 *if_sid_out, u32 *msg_sid_out)
162{
163 if (if_sid_out)
164 *if_sid_out = if_sid_in;
165 if (msg_sid_out)
166 *msg_sid_out = msg_sid_in;
167}
168
169static int sel_netif_sids_slow(struct net_device *dev, u32 *if_sid, u32 *msg_sid)
170{
171 int ret = 0;
172 u32 tmp_if_sid, tmp_msg_sid;
173
174 ret = security_netif_sid(dev->name, &tmp_if_sid, &tmp_msg_sid);
175 if (!ret)
176 sel_netif_assign_sids(tmp_if_sid, tmp_msg_sid, if_sid, msg_sid);
177 return ret;
178}
179
180int sel_netif_sids(struct net_device *dev, u32 *if_sid, u32 *msg_sid)
181{
182 int ret = 0;
183 struct sel_netif *netif;
184
185 rcu_read_lock();
186 netif = sel_netif_lookup(dev);
187 if (IS_ERR(netif)) {
188 rcu_read_unlock();
189 ret = sel_netif_sids_slow(dev, if_sid, msg_sid);
190 goto out;
191 }
192 sel_netif_assign_sids(netif->nsec.if_sid, netif->nsec.msg_sid, if_sid, msg_sid);
193 rcu_read_unlock();
194out:
195 return ret;
196}
197
198static void sel_netif_kill(struct net_device *dev)
199{
200 struct sel_netif *netif;
201
202 spin_lock_bh(&sel_netif_lock);
203 netif = sel_netif_find(dev);
204 if (netif)
205 sel_netif_destroy(netif);
206 spin_unlock_bh(&sel_netif_lock);
207}
208
209static void sel_netif_flush(void)
210{
211 int idx;
212
213 spin_lock_bh(&sel_netif_lock);
214 for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) {
215 struct sel_netif *netif;
216
217 list_for_each_entry(netif, &sel_netif_hash[idx], list)
218 sel_netif_destroy(netif);
219 }
220 spin_unlock_bh(&sel_netif_lock);
221}
222
223static int sel_netif_avc_callback(u32 event, u32 ssid, u32 tsid,
224 u16 class, u32 perms, u32 *retained)
225{
226 if (event == AVC_CALLBACK_RESET) {
227 sel_netif_flush();
228 synchronize_net();
229 }
230 return 0;
231}
232
233static int sel_netif_netdev_notifier_handler(struct notifier_block *this,
234 unsigned long event, void *ptr)
235{
236 struct net_device *dev = ptr;
237
238 if (dev->nd_net != &init_net)
239 return NOTIFY_DONE;
240
241 if (event == NETDEV_DOWN)
242 sel_netif_kill(dev);
243
244 return NOTIFY_DONE;
245}
246
247static struct notifier_block sel_netif_netdev_notifier = {
248 .notifier_call = sel_netif_netdev_notifier_handler,
249};
250
251static __init int sel_netif_init(void)
252{
253 int i, err = 0;
254
255 if (!selinux_enabled)
256 goto out;
257
258 for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)
259 INIT_LIST_HEAD(&sel_netif_hash[i]);
260
261 register_netdevice_notifier(&sel_netif_netdev_notifier);
262
263 err = avc_add_callback(sel_netif_avc_callback, AVC_CALLBACK_RESET,
264 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
265 if (err)
266 panic("avc_add_callback() failed, error %d\n", err);
267
268out:
269 return err;
270}
271
272__initcall(sel_netif_init);
273
274
