blob: cbe6ec246412e04bc3421385b1856a835bb7b0c0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Network interface table.
3 *
4 * Network interfaces (devices) do not have a security field, so we
5 * maintain a table associating each interface with a SID.
6 *
7 * Author: James Morris <jmorris@redhat.com>
8 *
9 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
Paul Mooree8bfdb92008-01-29 08:38:08 -050010 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
Paul Moore82c21bf2011-08-01 11:10:33 +000011 * Paul Moore <paul@paul-moore.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2,
15 * as published by the Free Software Foundation.
16 */
17#include <linux/init.h>
18#include <linux/types.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090019#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/stddef.h>
21#include <linux/kernel.h>
22#include <linux/list.h>
23#include <linux/notifier.h>
24#include <linux/netdevice.h>
25#include <linux/rcupdate.h>
Eric W. Biedermane9dc8652007-09-12 13:02:17 +020026#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28#include "security.h"
29#include "objsec.h"
30#include "netif.h"
31
32#define SEL_NETIF_HASH_SIZE 64
33#define SEL_NETIF_HASH_MAX 1024
34
Eric Paris338366c2008-04-18 17:38:22 -040035struct sel_netif {
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 struct list_head list;
37 struct netif_security_struct nsec;
38 struct rcu_head rcu_head;
39};
40
41static u32 sel_netif_total;
42static LIST_HEAD(sel_netif_list);
43static DEFINE_SPINLOCK(sel_netif_lock);
44static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE];
45
Paul Mooree8bfdb92008-01-29 08:38:08 -050046/**
47 * sel_netif_hashfn - Hashing function for the interface table
Paul Moorecbe0d6e2014-09-10 17:09:57 -040048 * @ns: the network namespace
Paul Mooree8bfdb92008-01-29 08:38:08 -050049 * @ifindex: the network interface
50 *
51 * Description:
52 * This is the hashing function for the network interface table, it returns the
53 * bucket number for the given interface.
54 *
55 */
Paul Moorecbe0d6e2014-09-10 17:09:57 -040056static inline u32 sel_netif_hashfn(const struct net *ns, int ifindex)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
Paul Moorecbe0d6e2014-09-10 17:09:57 -040058 return (((uintptr_t)ns + ifindex) & (SEL_NETIF_HASH_SIZE - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -070059}
60
Paul Mooree8bfdb92008-01-29 08:38:08 -050061/**
62 * sel_netif_find - Search for an interface record
Paul Moorecbe0d6e2014-09-10 17:09:57 -040063 * @ns: the network namespace
Paul Mooree8bfdb92008-01-29 08:38:08 -050064 * @ifindex: the network interface
65 *
66 * Description:
67 * Search the network interface table and return the record matching @ifindex.
68 * If an entry can not be found in the table return NULL.
69 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 */
Paul Moorecbe0d6e2014-09-10 17:09:57 -040071static inline struct sel_netif *sel_netif_find(const struct net *ns,
72 int ifindex)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073{
Paul Moorecbe0d6e2014-09-10 17:09:57 -040074 int idx = sel_netif_hashfn(ns, ifindex);
Paul Mooree8bfdb92008-01-29 08:38:08 -050075 struct sel_netif *netif;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
Paul Mooree8bfdb92008-01-29 08:38:08 -050077 list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list)
Paul Moorecbe0d6e2014-09-10 17:09:57 -040078 if (net_eq(netif->nsec.ns, ns) &&
79 netif->nsec.ifindex == ifindex)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 return netif;
Paul Mooree8bfdb92008-01-29 08:38:08 -050081
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 return NULL;
83}
84
Paul Mooree8bfdb92008-01-29 08:38:08 -050085/**
86 * sel_netif_insert - Insert a new interface into the table
87 * @netif: the new interface record
88 *
89 * Description:
90 * Add a new interface record to the network interface hash table. Returns
91 * zero on success, negative values on failure.
92 *
93 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070094static int sel_netif_insert(struct sel_netif *netif)
95{
Paul Mooree8bfdb92008-01-29 08:38:08 -050096 int idx;
Eric Paris338366c2008-04-18 17:38:22 -040097
Paul Mooree8bfdb92008-01-29 08:38:08 -050098 if (sel_netif_total >= SEL_NETIF_HASH_MAX)
99 return -ENOSPC;
Eric Paris338366c2008-04-18 17:38:22 -0400100
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400101 idx = sel_netif_hashfn(netif->nsec.ns, netif->nsec.ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 list_add_rcu(&netif->list, &sel_netif_hash[idx]);
103 sel_netif_total++;
Paul Mooree8bfdb92008-01-29 08:38:08 -0500104
105 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106}
107
Paul Mooree8bfdb92008-01-29 08:38:08 -0500108/**
Paul Mooree8bfdb92008-01-29 08:38:08 -0500109 * sel_netif_destroy - Remove an interface record from the table
110 * @netif: the existing interface record
111 *
112 * Description:
113 * Remove an existing interface record from the network interface table.
114 *
115 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116static void sel_netif_destroy(struct sel_netif *netif)
117{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 list_del_rcu(&netif->list);
119 sel_netif_total--;
Lai Jiangshan690273f2011-03-18 12:03:19 +0800120 kfree_rcu(netif, rcu_head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121}
122
Paul Mooree8bfdb92008-01-29 08:38:08 -0500123/**
124 * sel_netif_sid_slow - Lookup the SID of a network interface using the policy
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400125 * @ns: the network namespace
Paul Mooree8bfdb92008-01-29 08:38:08 -0500126 * @ifindex: the network interface
127 * @sid: interface SID
128 *
129 * Description:
130 * This function determines the SID of a network interface by quering the
131 * security policy. The result is added to the network interface table to
132 * speedup future queries. Returns zero on success, negative values on
133 * failure.
134 *
135 */
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400136static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{
Paul Moore9b80c362019-08-01 17:55:06 -0400138 int ret = 0;
Paul Mooree8bfdb92008-01-29 08:38:08 -0500139 struct sel_netif *netif;
Paul Moore9b80c362019-08-01 17:55:06 -0400140 struct sel_netif *new;
Paul Mooree8bfdb92008-01-29 08:38:08 -0500141 struct net_device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Paul Mooree8bfdb92008-01-29 08:38:08 -0500143 /* NOTE: we always use init's network namespace since we don't
144 * currently support containers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400146 dev = dev_get_by_index(ns, ifindex);
Paul Moore71f1cb02008-01-29 08:51:16 -0500147 if (unlikely(dev == NULL)) {
peter enderborg0d3a1152018-06-12 10:09:10 +0200148 pr_warn("SELinux: failure in %s(), invalid network interface (%d)\n",
149 __func__, ifindex);
Paul Mooree8bfdb92008-01-29 08:38:08 -0500150 return -ENOENT;
Paul Moore71f1cb02008-01-29 08:51:16 -0500151 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 spin_lock_bh(&sel_netif_lock);
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400154 netif = sel_netif_find(ns, ifindex);
Paul Mooree8bfdb92008-01-29 08:38:08 -0500155 if (netif != NULL) {
156 *sid = netif->nsec.sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 goto out;
158 }
Paul Moore9b80c362019-08-01 17:55:06 -0400159
160 ret = security_netif_sid(&selinux_state, dev->name, sid);
161 if (ret != 0)
162 goto out;
Paul Mooree8bfdb92008-01-29 08:38:08 -0500163 new = kzalloc(sizeof(*new), GFP_ATOMIC);
Paul Moore9b80c362019-08-01 17:55:06 -0400164 if (new) {
165 new->nsec.ns = ns;
166 new->nsec.ifindex = ifindex;
167 new->nsec.sid = *sid;
168 if (sel_netif_insert(new))
169 kfree(new);
Paul Mooree8bfdb92008-01-29 08:38:08 -0500170 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172out:
Paul Mooree8bfdb92008-01-29 08:38:08 -0500173 spin_unlock_bh(&sel_netif_lock);
174 dev_put(dev);
Paul Moore9b80c362019-08-01 17:55:06 -0400175 if (unlikely(ret))
peter enderborg0d3a1152018-06-12 10:09:10 +0200176 pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n",
177 __func__, ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 return ret;
179}
180
Paul Mooree8bfdb92008-01-29 08:38:08 -0500181/**
182 * sel_netif_sid - Lookup the SID of a network interface
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400183 * @ns: the network namespace
Paul Mooree8bfdb92008-01-29 08:38:08 -0500184 * @ifindex: the network interface
185 * @sid: interface SID
186 *
187 * Description:
188 * This function determines the SID of a network interface using the fastest
189 * method possible. First the interface table is queried, but if an entry
190 * can't be found then the policy is queried and the result is added to the
191 * table to speedup future queries. Returns zero on success, negative values
192 * on failure.
193 *
194 */
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400195int sel_netif_sid(struct net *ns, int ifindex, u32 *sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 struct sel_netif *netif;
198
199 rcu_read_lock();
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400200 netif = sel_netif_find(ns, ifindex);
Paul Mooree8bfdb92008-01-29 08:38:08 -0500201 if (likely(netif != NULL)) {
202 *sid = netif->nsec.sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 rcu_read_unlock();
Paul Mooree8bfdb92008-01-29 08:38:08 -0500204 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 rcu_read_unlock();
Paul Mooree8bfdb92008-01-29 08:38:08 -0500207
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400208 return sel_netif_sid_slow(ns, ifindex, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209}
210
Paul Mooree8bfdb92008-01-29 08:38:08 -0500211/**
212 * sel_netif_kill - Remove an entry from the network interface table
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400213 * @ns: the network namespace
Paul Mooree8bfdb92008-01-29 08:38:08 -0500214 * @ifindex: the network interface
215 *
216 * Description:
217 * This function removes the entry matching @ifindex from the network interface
218 * table if it exists.
219 *
220 */
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400221static void sel_netif_kill(const struct net *ns, int ifindex)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222{
223 struct sel_netif *netif;
224
Paul E. McKenney61844252008-04-21 18:12:33 -0700225 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 spin_lock_bh(&sel_netif_lock);
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400227 netif = sel_netif_find(ns, ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 if (netif)
229 sel_netif_destroy(netif);
230 spin_unlock_bh(&sel_netif_lock);
Paul E. McKenney61844252008-04-21 18:12:33 -0700231 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}
233
Paul Mooree8bfdb92008-01-29 08:38:08 -0500234/**
235 * sel_netif_flush - Flush the entire network interface table
236 *
237 * Description:
238 * Remove all entries from the network interface table.
239 *
240 */
Paul Moore615e51f2014-06-26 14:33:56 -0400241void sel_netif_flush(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
243 int idx;
Paul Mooree8bfdb92008-01-29 08:38:08 -0500244 struct sel_netif *netif;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246 spin_lock_bh(&sel_netif_lock);
Paul Mooree8bfdb92008-01-29 08:38:08 -0500247 for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 list_for_each_entry(netif, &sel_netif_hash[idx], list)
249 sel_netif_destroy(netif);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 spin_unlock_bh(&sel_netif_lock);
251}
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253static int sel_netif_netdev_notifier_handler(struct notifier_block *this,
Eric Paris338366c2008-04-18 17:38:22 -0400254 unsigned long event, void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
Jiri Pirko351638e2013-05-28 01:30:21 +0000256 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 if (event == NETDEV_DOWN)
Paul Moorecbe0d6e2014-09-10 17:09:57 -0400259 sel_netif_kill(dev_net(dev), dev->ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
261 return NOTIFY_DONE;
262}
263
264static struct notifier_block sel_netif_netdev_notifier = {
265 .notifier_call = sel_netif_netdev_notifier_handler,
266};
267
268static __init int sel_netif_init(void)
269{
Paul Moore942ba362014-08-07 20:55:30 -0400270 int i;
Eric Paris338366c2008-04-18 17:38:22 -0400271
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 if (!selinux_enabled)
Paul Mooree8bfdb92008-01-29 08:38:08 -0500273 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275 for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)
276 INIT_LIST_HEAD(&sel_netif_hash[i]);
277
278 register_netdevice_notifier(&sel_netif_netdev_notifier);
Eric Paris338366c2008-04-18 17:38:22 -0400279
Paul Moore942ba362014-08-07 20:55:30 -0400280 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281}
282
283__initcall(sel_netif_init);
284