]>
Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * Network interface table. | |
4 | * | |
5 | * Network interfaces (devices) do not have a security field, so we | |
6 | * maintain a table associating each interface with a SID. | |
7 | * | |
8 | * Author: James Morris <jmorris@redhat.com> | |
9 | * | |
10 | * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> | |
e8bfdb9d | 11 | * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. |
82c21bfa | 12 | * Paul Moore <paul@paul-moore.com> |
1da177e4 LT |
13 | */ |
14 | #include <linux/init.h> | |
15 | #include <linux/types.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
1da177e4 LT |
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> | |
e9dc8653 | 23 | #include <net/net_namespace.h> |
1da177e4 LT |
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 | ||
338366cb | 32 | struct sel_netif { |
1da177e4 LT |
33 | struct list_head list; |
34 | struct netif_security_struct nsec; | |
35 | struct rcu_head rcu_head; | |
36 | }; | |
37 | ||
38 | static u32 sel_netif_total; | |
39 | static LIST_HEAD(sel_netif_list); | |
40 | static DEFINE_SPINLOCK(sel_netif_lock); | |
41 | static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE]; | |
42 | ||
e8bfdb9d PM |
43 | /** |
44 | * sel_netif_hashfn - Hashing function for the interface table | |
cbe0d6e8 | 45 | * @ns: the network namespace |
e8bfdb9d PM |
46 | * @ifindex: the network interface |
47 | * | |
48 | * Description: | |
49 | * This is the hashing function for the network interface table, it returns the | |
50 | * bucket number for the given interface. | |
51 | * | |
52 | */ | |
cbe0d6e8 | 53 | static inline u32 sel_netif_hashfn(const struct net *ns, int ifindex) |
1da177e4 | 54 | { |
cbe0d6e8 | 55 | return (((uintptr_t)ns + ifindex) & (SEL_NETIF_HASH_SIZE - 1)); |
1da177e4 LT |
56 | } |
57 | ||
e8bfdb9d PM |
58 | /** |
59 | * sel_netif_find - Search for an interface record | |
cbe0d6e8 | 60 | * @ns: the network namespace |
e8bfdb9d PM |
61 | * @ifindex: the network interface |
62 | * | |
63 | * Description: | |
64 | * Search the network interface table and return the record matching @ifindex. | |
65 | * If an entry can not be found in the table return NULL. | |
66 | * | |
1da177e4 | 67 | */ |
cbe0d6e8 PM |
68 | static inline struct sel_netif *sel_netif_find(const struct net *ns, |
69 | int ifindex) | |
1da177e4 | 70 | { |
cbe0d6e8 | 71 | int idx = sel_netif_hashfn(ns, ifindex); |
e8bfdb9d | 72 | struct sel_netif *netif; |
1da177e4 | 73 | |
e8bfdb9d | 74 | list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list) |
cbe0d6e8 PM |
75 | if (net_eq(netif->nsec.ns, ns) && |
76 | netif->nsec.ifindex == ifindex) | |
1da177e4 | 77 | return netif; |
e8bfdb9d | 78 | |
1da177e4 LT |
79 | return NULL; |
80 | } | |
81 | ||
e8bfdb9d PM |
82 | /** |
83 | * sel_netif_insert - Insert a new interface into the table | |
84 | * @netif: the new interface record | |
85 | * | |
86 | * Description: | |
87 | * Add a new interface record to the network interface hash table. Returns | |
88 | * zero on success, negative values on failure. | |
89 | * | |
90 | */ | |
1da177e4 LT |
91 | static int sel_netif_insert(struct sel_netif *netif) |
92 | { | |
e8bfdb9d | 93 | int idx; |
338366cb | 94 | |
e8bfdb9d PM |
95 | if (sel_netif_total >= SEL_NETIF_HASH_MAX) |
96 | return -ENOSPC; | |
338366cb | 97 | |
cbe0d6e8 | 98 | idx = sel_netif_hashfn(netif->nsec.ns, netif->nsec.ifindex); |
1da177e4 LT |
99 | list_add_rcu(&netif->list, &sel_netif_hash[idx]); |
100 | sel_netif_total++; | |
e8bfdb9d PM |
101 | |
102 | return 0; | |
1da177e4 LT |
103 | } |
104 | ||
e8bfdb9d PM |
105 | /** |
106 | * sel_netif_destroy - Remove an interface record from the table | |
107 | * @netif: the existing interface record | |
108 | * | |
109 | * Description: | |
110 | * Remove an existing interface record from the network interface table. | |
111 | * | |
112 | */ | |
1da177e4 LT |
113 | static void sel_netif_destroy(struct sel_netif *netif) |
114 | { | |
1da177e4 LT |
115 | list_del_rcu(&netif->list); |
116 | sel_netif_total--; | |
690273fc | 117 | kfree_rcu(netif, rcu_head); |
1da177e4 LT |
118 | } |
119 | ||
e8bfdb9d PM |
120 | /** |
121 | * sel_netif_sid_slow - Lookup the SID of a network interface using the policy | |
cbe0d6e8 | 122 | * @ns: the network namespace |
e8bfdb9d PM |
123 | * @ifindex: the network interface |
124 | * @sid: interface SID | |
125 | * | |
126 | * Description: | |
127 | * This function determines the SID of a network interface by quering the | |
128 | * security policy. The result is added to the network interface table to | |
129 | * speedup future queries. Returns zero on success, negative values on | |
130 | * failure. | |
131 | * | |
132 | */ | |
cbe0d6e8 | 133 | static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid) |
1da177e4 LT |
134 | { |
135 | int ret; | |
e8bfdb9d PM |
136 | struct sel_netif *netif; |
137 | struct sel_netif *new = NULL; | |
138 | struct net_device *dev; | |
1da177e4 | 139 | |
e8bfdb9d PM |
140 | /* NOTE: we always use init's network namespace since we don't |
141 | * currently support containers */ | |
1da177e4 | 142 | |
cbe0d6e8 | 143 | dev = dev_get_by_index(ns, ifindex); |
71f1cb05 | 144 | if (unlikely(dev == NULL)) { |
0d3a1154 | 145 | pr_warn("SELinux: failure in %s(), invalid network interface (%d)\n", |
146 | __func__, ifindex); | |
e8bfdb9d | 147 | return -ENOENT; |
71f1cb05 | 148 | } |
1da177e4 | 149 | |
1da177e4 | 150 | spin_lock_bh(&sel_netif_lock); |
cbe0d6e8 | 151 | netif = sel_netif_find(ns, ifindex); |
e8bfdb9d PM |
152 | if (netif != NULL) { |
153 | *sid = netif->nsec.sid; | |
154 | ret = 0; | |
1da177e4 LT |
155 | goto out; |
156 | } | |
e8bfdb9d PM |
157 | new = kzalloc(sizeof(*new), GFP_ATOMIC); |
158 | if (new == NULL) { | |
159 | ret = -ENOMEM; | |
1da177e4 LT |
160 | goto out; |
161 | } | |
aa8e712c | 162 | ret = security_netif_sid(&selinux_state, dev->name, &new->nsec.sid); |
e8bfdb9d PM |
163 | if (ret != 0) |
164 | goto out; | |
cbe0d6e8 | 165 | new->nsec.ns = ns; |
e8bfdb9d PM |
166 | new->nsec.ifindex = ifindex; |
167 | ret = sel_netif_insert(new); | |
168 | if (ret != 0) | |
169 | goto out; | |
170 | *sid = new->nsec.sid; | |
1da177e4 | 171 | |
1da177e4 | 172 | out: |
e8bfdb9d PM |
173 | spin_unlock_bh(&sel_netif_lock); |
174 | dev_put(dev); | |
71f1cb05 | 175 | if (unlikely(ret)) { |
0d3a1154 | 176 | pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n", |
177 | __func__, ifindex); | |
e8bfdb9d | 178 | kfree(new); |
71f1cb05 | 179 | } |
1da177e4 LT |
180 | return ret; |
181 | } | |
182 | ||
e8bfdb9d PM |
183 | /** |
184 | * sel_netif_sid - Lookup the SID of a network interface | |
cbe0d6e8 | 185 | * @ns: the network namespace |
e8bfdb9d PM |
186 | * @ifindex: the network interface |
187 | * @sid: interface SID | |
188 | * | |
189 | * Description: | |
190 | * This function determines the SID of a network interface using the fastest | |
191 | * method possible. First the interface table is queried, but if an entry | |
192 | * can't be found then the policy is queried and the result is added to the | |
193 | * table to speedup future queries. Returns zero on success, negative values | |
194 | * on failure. | |
195 | * | |
196 | */ | |
cbe0d6e8 | 197 | int sel_netif_sid(struct net *ns, int ifindex, u32 *sid) |
1da177e4 | 198 | { |
1da177e4 LT |
199 | struct sel_netif *netif; |
200 | ||
201 | rcu_read_lock(); | |
cbe0d6e8 | 202 | netif = sel_netif_find(ns, ifindex); |
e8bfdb9d PM |
203 | if (likely(netif != NULL)) { |
204 | *sid = netif->nsec.sid; | |
1da177e4 | 205 | rcu_read_unlock(); |
e8bfdb9d | 206 | return 0; |
1da177e4 | 207 | } |
1da177e4 | 208 | rcu_read_unlock(); |
e8bfdb9d | 209 | |
cbe0d6e8 | 210 | return sel_netif_sid_slow(ns, ifindex, sid); |
1da177e4 LT |
211 | } |
212 | ||
e8bfdb9d PM |
213 | /** |
214 | * sel_netif_kill - Remove an entry from the network interface table | |
cbe0d6e8 | 215 | * @ns: the network namespace |
e8bfdb9d PM |
216 | * @ifindex: the network interface |
217 | * | |
218 | * Description: | |
219 | * This function removes the entry matching @ifindex from the network interface | |
220 | * table if it exists. | |
221 | * | |
222 | */ | |
cbe0d6e8 | 223 | static void sel_netif_kill(const struct net *ns, int ifindex) |
1da177e4 LT |
224 | { |
225 | struct sel_netif *netif; | |
226 | ||
61844250 | 227 | rcu_read_lock(); |
1da177e4 | 228 | spin_lock_bh(&sel_netif_lock); |
cbe0d6e8 | 229 | netif = sel_netif_find(ns, ifindex); |
1da177e4 LT |
230 | if (netif) |
231 | sel_netif_destroy(netif); | |
232 | spin_unlock_bh(&sel_netif_lock); | |
61844250 | 233 | rcu_read_unlock(); |
1da177e4 LT |
234 | } |
235 | ||
e8bfdb9d PM |
236 | /** |
237 | * sel_netif_flush - Flush the entire network interface table | |
238 | * | |
239 | * Description: | |
240 | * Remove all entries from the network interface table. | |
241 | * | |
242 | */ | |
615e51fd | 243 | void sel_netif_flush(void) |
1da177e4 LT |
244 | { |
245 | int idx; | |
e8bfdb9d | 246 | struct sel_netif *netif; |
1da177e4 LT |
247 | |
248 | spin_lock_bh(&sel_netif_lock); | |
e8bfdb9d | 249 | for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) |
1da177e4 LT |
250 | list_for_each_entry(netif, &sel_netif_hash[idx], list) |
251 | sel_netif_destroy(netif); | |
1da177e4 LT |
252 | spin_unlock_bh(&sel_netif_lock); |
253 | } | |
254 | ||
1da177e4 | 255 | static int sel_netif_netdev_notifier_handler(struct notifier_block *this, |
338366cb | 256 | unsigned long event, void *ptr) |
1da177e4 | 257 | { |
351638e7 | 258 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
1da177e4 LT |
259 | |
260 | if (event == NETDEV_DOWN) | |
cbe0d6e8 | 261 | sel_netif_kill(dev_net(dev), dev->ifindex); |
1da177e4 LT |
262 | |
263 | return NOTIFY_DONE; | |
264 | } | |
265 | ||
266 | static struct notifier_block sel_netif_netdev_notifier = { | |
267 | .notifier_call = sel_netif_netdev_notifier_handler, | |
268 | }; | |
269 | ||
270 | static __init int sel_netif_init(void) | |
271 | { | |
942ba364 | 272 | int i; |
338366cb | 273 | |
1da177e4 | 274 | if (!selinux_enabled) |
e8bfdb9d | 275 | return 0; |
1da177e4 LT |
276 | |
277 | for (i = 0; i < SEL_NETIF_HASH_SIZE; i++) | |
278 | INIT_LIST_HEAD(&sel_netif_hash[i]); | |
279 | ||
280 | register_netdevice_notifier(&sel_netif_netdev_notifier); | |
338366cb | 281 | |
942ba364 | 282 | return 0; |
1da177e4 LT |
283 | } |
284 | ||
285 | __initcall(sel_netif_init); | |
286 |