Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 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 Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 10 | * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 11 | * Paul Moore <paul.moore@hp.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * |
| 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> |
| 19 | #include <linux/stddef.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/list.h> |
| 22 | #include <linux/notifier.h> |
| 23 | #include <linux/netdevice.h> |
| 24 | #include <linux/rcupdate.h> |
Eric W. Biederman | e9dc8653 | 2007-09-12 13:02:17 +0200 | [diff] [blame] | 25 | #include <net/net_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
| 27 | #include "security.h" |
| 28 | #include "objsec.h" |
| 29 | #include "netif.h" |
| 30 | |
| 31 | #define SEL_NETIF_HASH_SIZE 64 |
| 32 | #define SEL_NETIF_HASH_MAX 1024 |
| 33 | |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 34 | struct sel_netif { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | struct list_head list; |
| 36 | struct netif_security_struct nsec; |
| 37 | struct rcu_head rcu_head; |
| 38 | }; |
| 39 | |
| 40 | static u32 sel_netif_total; |
| 41 | static LIST_HEAD(sel_netif_list); |
| 42 | static DEFINE_SPINLOCK(sel_netif_lock); |
| 43 | static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE]; |
| 44 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 45 | /** |
| 46 | * sel_netif_hashfn - Hashing function for the interface table |
| 47 | * @ifindex: the network interface |
| 48 | * |
| 49 | * Description: |
| 50 | * This is the hashing function for the network interface table, it returns the |
| 51 | * bucket number for the given interface. |
| 52 | * |
| 53 | */ |
| 54 | static inline u32 sel_netif_hashfn(int ifindex) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | { |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 56 | return (ifindex & (SEL_NETIF_HASH_SIZE - 1)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | } |
| 58 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 59 | /** |
| 60 | * sel_netif_find - Search for an interface record |
| 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 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | */ |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 68 | static inline struct sel_netif *sel_netif_find(int ifindex) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | { |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 70 | int idx = sel_netif_hashfn(ifindex); |
| 71 | struct sel_netif *netif; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 73 | list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list) |
| 74 | /* all of the devices should normally fit in the hash, so we |
| 75 | * optimize for that case */ |
| 76 | if (likely(netif->nsec.ifindex == ifindex)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | return netif; |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 78 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | return NULL; |
| 80 | } |
| 81 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 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 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | static int sel_netif_insert(struct sel_netif *netif) |
| 92 | { |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 93 | int idx; |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 94 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 95 | if (sel_netif_total >= SEL_NETIF_HASH_MAX) |
| 96 | return -ENOSPC; |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 97 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 98 | idx = sel_netif_hashfn(netif->nsec.ifindex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | list_add_rcu(&netif->list, &sel_netif_hash[idx]); |
| 100 | sel_netif_total++; |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 101 | |
| 102 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | } |
| 104 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 105 | /** |
| 106 | * sel_netif_free - Frees an interface entry |
| 107 | * @p: the entry's RCU field |
| 108 | * |
| 109 | * Description: |
| 110 | * This function is designed to be used as a callback to the call_rcu() |
| 111 | * function so that memory allocated to a hash table interface entry can be |
| 112 | * released safely. |
| 113 | * |
| 114 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | static void sel_netif_free(struct rcu_head *p) |
| 116 | { |
| 117 | struct sel_netif *netif = container_of(p, struct sel_netif, rcu_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | kfree(netif); |
| 119 | } |
| 120 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 121 | /** |
| 122 | * sel_netif_destroy - Remove an interface record from the table |
| 123 | * @netif: the existing interface record |
| 124 | * |
| 125 | * Description: |
| 126 | * Remove an existing interface record from the network interface table. |
| 127 | * |
| 128 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | static void sel_netif_destroy(struct sel_netif *netif) |
| 130 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | list_del_rcu(&netif->list); |
| 132 | sel_netif_total--; |
| 133 | call_rcu(&netif->rcu_head, sel_netif_free); |
| 134 | } |
| 135 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 136 | /** |
| 137 | * sel_netif_sid_slow - Lookup the SID of a network interface using the policy |
| 138 | * @ifindex: the network interface |
| 139 | * @sid: interface SID |
| 140 | * |
| 141 | * Description: |
| 142 | * This function determines the SID of a network interface by quering the |
| 143 | * security policy. The result is added to the network interface table to |
| 144 | * speedup future queries. Returns zero on success, negative values on |
| 145 | * failure. |
| 146 | * |
| 147 | */ |
| 148 | static int sel_netif_sid_slow(int ifindex, u32 *sid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | { |
| 150 | int ret; |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 151 | struct sel_netif *netif; |
| 152 | struct sel_netif *new = NULL; |
| 153 | struct net_device *dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 155 | /* NOTE: we always use init's network namespace since we don't |
| 156 | * currently support containers */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 158 | dev = dev_get_by_index(&init_net, ifindex); |
Paul Moore | 71f1cb0 | 2008-01-29 08:51:16 -0500 | [diff] [blame] | 159 | if (unlikely(dev == NULL)) { |
| 160 | printk(KERN_WARNING |
| 161 | "SELinux: failure in sel_netif_sid_slow()," |
| 162 | " invalid network interface (%d)\n", ifindex); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 163 | return -ENOENT; |
Paul Moore | 71f1cb0 | 2008-01-29 08:51:16 -0500 | [diff] [blame] | 164 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | spin_lock_bh(&sel_netif_lock); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 167 | netif = sel_netif_find(ifindex); |
| 168 | if (netif != NULL) { |
| 169 | *sid = netif->nsec.sid; |
| 170 | ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | goto out; |
| 172 | } |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 173 | new = kzalloc(sizeof(*new), GFP_ATOMIC); |
| 174 | if (new == NULL) { |
| 175 | ret = -ENOMEM; |
| 176 | goto out; |
| 177 | } |
| 178 | ret = security_netif_sid(dev->name, &new->nsec.sid); |
| 179 | if (ret != 0) |
| 180 | goto out; |
| 181 | new->nsec.ifindex = ifindex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | ret = sel_netif_insert(new); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 183 | if (ret != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | goto out; |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 185 | *sid = new->nsec.sid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | out: |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 188 | spin_unlock_bh(&sel_netif_lock); |
| 189 | dev_put(dev); |
Paul Moore | 71f1cb0 | 2008-01-29 08:51:16 -0500 | [diff] [blame] | 190 | if (unlikely(ret)) { |
| 191 | printk(KERN_WARNING |
| 192 | "SELinux: failure in sel_netif_sid_slow()," |
| 193 | " unable to determine network interface label (%d)\n", |
| 194 | ifindex); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 195 | kfree(new); |
Paul Moore | 71f1cb0 | 2008-01-29 08:51:16 -0500 | [diff] [blame] | 196 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | return ret; |
| 198 | } |
| 199 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 200 | /** |
| 201 | * sel_netif_sid - Lookup the SID of a network interface |
| 202 | * @ifindex: the network interface |
| 203 | * @sid: interface SID |
| 204 | * |
| 205 | * Description: |
| 206 | * This function determines the SID of a network interface using the fastest |
| 207 | * method possible. First the interface table is queried, but if an entry |
| 208 | * can't be found then the policy is queried and the result is added to the |
| 209 | * table to speedup future queries. Returns zero on success, negative values |
| 210 | * on failure. |
| 211 | * |
| 212 | */ |
| 213 | int sel_netif_sid(int ifindex, u32 *sid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | struct sel_netif *netif; |
| 216 | |
| 217 | rcu_read_lock(); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 218 | netif = sel_netif_find(ifindex); |
| 219 | if (likely(netif != NULL)) { |
| 220 | *sid = netif->nsec.sid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | rcu_read_unlock(); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 222 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | rcu_read_unlock(); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 225 | |
| 226 | return sel_netif_sid_slow(ifindex, sid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | } |
| 228 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 229 | /** |
| 230 | * sel_netif_kill - Remove an entry from the network interface table |
| 231 | * @ifindex: the network interface |
| 232 | * |
| 233 | * Description: |
| 234 | * This function removes the entry matching @ifindex from the network interface |
| 235 | * table if it exists. |
| 236 | * |
| 237 | */ |
| 238 | static void sel_netif_kill(int ifindex) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | { |
| 240 | struct sel_netif *netif; |
| 241 | |
Paul E. McKenney | 6184425 | 2008-04-21 18:12:33 -0700 | [diff] [blame] | 242 | rcu_read_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | spin_lock_bh(&sel_netif_lock); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 244 | netif = sel_netif_find(ifindex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | if (netif) |
| 246 | sel_netif_destroy(netif); |
| 247 | spin_unlock_bh(&sel_netif_lock); |
Paul E. McKenney | 6184425 | 2008-04-21 18:12:33 -0700 | [diff] [blame] | 248 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | } |
| 250 | |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 251 | /** |
| 252 | * sel_netif_flush - Flush the entire network interface table |
| 253 | * |
| 254 | * Description: |
| 255 | * Remove all entries from the network interface table. |
| 256 | * |
| 257 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | static void sel_netif_flush(void) |
| 259 | { |
| 260 | int idx; |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 261 | struct sel_netif *netif; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | |
| 263 | spin_lock_bh(&sel_netif_lock); |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 264 | for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | list_for_each_entry(netif, &sel_netif_hash[idx], list) |
| 266 | sel_netif_destroy(netif); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | spin_unlock_bh(&sel_netif_lock); |
| 268 | } |
| 269 | |
| 270 | static int sel_netif_avc_callback(u32 event, u32 ssid, u32 tsid, |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 271 | u16 class, u32 perms, u32 *retained) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | { |
| 273 | if (event == AVC_CALLBACK_RESET) { |
| 274 | sel_netif_flush(); |
| 275 | synchronize_net(); |
| 276 | } |
| 277 | return 0; |
| 278 | } |
| 279 | |
| 280 | static int sel_netif_netdev_notifier_handler(struct notifier_block *this, |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 281 | unsigned long event, void *ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | { |
| 283 | struct net_device *dev = ptr; |
| 284 | |
YOSHIFUJI Hideaki | c346dca | 2008-03-25 21:47:49 +0900 | [diff] [blame] | 285 | if (dev_net(dev) != &init_net) |
Eric W. Biederman | e9dc8653 | 2007-09-12 13:02:17 +0200 | [diff] [blame] | 286 | return NOTIFY_DONE; |
| 287 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | if (event == NETDEV_DOWN) |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 289 | sel_netif_kill(dev->ifindex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | |
| 291 | return NOTIFY_DONE; |
| 292 | } |
| 293 | |
| 294 | static struct notifier_block sel_netif_netdev_notifier = { |
| 295 | .notifier_call = sel_netif_netdev_notifier_handler, |
| 296 | }; |
| 297 | |
| 298 | static __init int sel_netif_init(void) |
| 299 | { |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 300 | int i, err; |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 301 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | if (!selinux_enabled) |
Paul Moore | e8bfdb9 | 2008-01-29 08:38:08 -0500 | [diff] [blame] | 303 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | |
| 305 | for (i = 0; i < SEL_NETIF_HASH_SIZE; i++) |
| 306 | INIT_LIST_HEAD(&sel_netif_hash[i]); |
| 307 | |
| 308 | register_netdevice_notifier(&sel_netif_netdev_notifier); |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 309 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | err = avc_add_callback(sel_netif_avc_callback, AVC_CALLBACK_RESET, |
Eric Paris | 338366c | 2008-04-18 17:38:22 -0400 | [diff] [blame] | 311 | SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | if (err) |
| 313 | panic("avc_add_callback() failed, error %d\n", err); |
| 314 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | return err; |
| 316 | } |
| 317 | |
| 318 | __initcall(sel_netif_init); |
| 319 | |