2 * Network interface table.
4 * Network interfaces (devices) do not have a security field, so we
5 * maintain a table associating each interface with a SID.
7 * Author: James Morris <jmorris@redhat.com>
9 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2,
13 * as published by the Free Software Foundation.
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>
28 #define SEL_NETIF_HASH_SIZE 64
29 #define SEL_NETIF_HASH_MAX 1024
36 #define DEBUGP(format, args...)
39 static u32 sel_netif_total;
40 static LIST_HEAD(sel_netif_list);
41 static spinlock_t sel_netif_lock = SPIN_LOCK_UNLOCKED;
42 static struct sel_netif sel_netif_hash[SEL_NETIF_HASH_SIZE];
44 static inline u32 sel_netif_hasfn(struct net_device *dev)
46 return (dev->ifindex & (SEL_NETIF_HASH_SIZE - 1));
50 * All of the devices should normally fit in the hash, so we optimize
53 static struct sel_netif *sel_netif_find(struct net_device *dev)
55 struct list_head *pos;
56 int idx = sel_netif_hasfn(dev);
58 __list_for_each_rcu(pos, &sel_netif_hash[idx].list) {
59 struct sel_netif *netif = list_entry(pos,
60 struct sel_netif, list);
61 if (likely(netif->nsec.dev == dev))
67 static int sel_netif_insert(struct sel_netif *netif)
71 if (sel_netif_total >= SEL_NETIF_HASH_MAX) {
76 idx = sel_netif_hasfn(netif->nsec.dev);
77 list_add_rcu(&netif->list, &sel_netif_hash[idx].list);
78 atomic_set(&netif->users, 1);
84 struct sel_netif *sel_netif_lookup(struct net_device *dev)
87 struct sel_netif *netif, *new;
88 struct netif_security_struct *nsec;
91 netif = sel_netif_find(dev);
94 if (likely(netif != NULL))
97 new = kmalloc(sizeof(*new), GFP_ATOMIC);
99 netif = ERR_PTR(-ENOMEM);
103 memset(new, 0, sizeof(*new));
106 ret = security_netif_sid(dev->name, &nsec->if_sid, &nsec->msg_sid);
109 netif = ERR_PTR(ret);
115 spin_lock_bh(&sel_netif_lock);
117 netif = sel_netif_find(dev);
119 spin_unlock_bh(&sel_netif_lock);
124 sel_netif_insert(new);
125 spin_unlock_bh(&sel_netif_lock);
129 DEBUGP("new: ifindex=%u name=%s if_sid=%u msg_sid=%u\n", dev->ifindex, dev->name,
130 nsec->if_sid, nsec->msg_sid);
132 atomic_inc(&netif->users);
137 static void sel_netif_free(struct rcu_head *p)
139 struct sel_netif *netif = container_of(p, struct sel_netif, rcu_head);
141 DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);
145 static void sel_netif_destroy(struct sel_netif *netif)
147 DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);
149 spin_lock_bh(&sel_netif_lock);
150 list_del_rcu(&netif->list);
152 spin_unlock_bh(&sel_netif_lock);
154 call_rcu(&netif->rcu_head, sel_netif_free);
157 void sel_netif_put(struct sel_netif *netif)
159 if (atomic_dec_and_test(&netif->users))
160 sel_netif_destroy(netif);
163 static void sel_netif_kill(struct net_device *dev)
165 struct sel_netif *netif;
168 netif = sel_netif_find(dev);
171 /* Drop internal reference */
173 sel_netif_put(netif);
176 static void sel_netif_flush(void)
180 for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) {
181 struct list_head *pos;
183 list_for_each_rcu(pos, &sel_netif_hash[idx].list) {
184 struct sel_netif *netif;
186 netif = list_entry(pos, struct sel_netif, list);
188 sel_netif_put(netif);
193 static int sel_netif_avc_callback(u32 event, u32 ssid, u32 tsid,
194 u16 class, u32 perms, u32 *retained)
196 if (event == AVC_CALLBACK_RESET) {
203 static int sel_netif_netdev_notifier_handler(struct notifier_block *this,
204 unsigned long event, void *ptr)
206 struct net_device *dev = ptr;
208 if (event == NETDEV_DOWN)
214 static struct notifier_block sel_netif_netdev_notifier = {
215 .notifier_call = sel_netif_netdev_notifier_handler,
218 static __init int sel_netif_init(void)
222 if (!selinux_enabled)
225 for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)
226 INIT_LIST_HEAD(&sel_netif_hash[i].list);
228 register_netdevice_notifier(&sel_netif_netdev_notifier);
230 err = avc_add_callback(sel_netif_avc_callback, AVC_CALLBACK_RESET,
231 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
233 panic("avc_add_callback() failed, error %d\n", err);
239 __initcall(sel_netif_init);