1 /* 2 * File: pn_dev.c 3 * 4 * Phonet network device 5 * 6 * Copyright (C) 2008 Nokia Corporation. 7 * 8 * Authors: Sakari Ailus <sakari.ailus@nokia.com> 9 * Rémi Denis-Courmont 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * version 2 as published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, but 16 * WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 23 * 02110-1301 USA 24 */ 25 26 #include <linux/kernel.h> 27 #include <linux/net.h> 28 #include <linux/slab.h> 29 #include <linux/netdevice.h> 30 #include <linux/phonet.h> 31 #include <linux/proc_fs.h> 32 #include <linux/if_arp.h> 33 #include <net/sock.h> 34 #include <net/netns/generic.h> 35 #include <net/phonet/pn_dev.h> 36 37 struct phonet_routes { 38 struct mutex lock; 39 struct net_device __rcu *table[64]; 40 }; 41 42 struct phonet_net { 43 struct phonet_device_list pndevs; 44 struct phonet_routes routes; 45 }; 46 47 static unsigned int phonet_net_id __read_mostly; 48 49 static struct phonet_net *phonet_pernet(struct net *net) 50 { 51 BUG_ON(!net); 52 53 return net_generic(net, phonet_net_id); 54 } 55 56 struct phonet_device_list *phonet_device_list(struct net *net) 57 { 58 struct phonet_net *pnn = phonet_pernet(net); 59 return &pnn->pndevs; 60 } 61 62 /* Allocate new Phonet device. */ 63 static struct phonet_device *__phonet_device_alloc(struct net_device *dev) 64 { 65 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); 66 struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC); 67 if (pnd == NULL) 68 return NULL; 69 pnd->netdev = dev; 70 bitmap_zero(pnd->addrs, 64); 71 72 BUG_ON(!mutex_is_locked(&pndevs->lock)); 73 list_add_rcu(&pnd->list, &pndevs->list); 74 return pnd; 75 } 76 77 static struct phonet_device *__phonet_get(struct net_device *dev) 78 { 79 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); 80 struct phonet_device *pnd; 81 82 BUG_ON(!mutex_is_locked(&pndevs->lock)); 83 list_for_each_entry(pnd, &pndevs->list, list) { 84 if (pnd->netdev == dev) 85 return pnd; 86 } 87 return NULL; 88 } 89 90 static struct phonet_device *__phonet_get_rcu(struct net_device *dev) 91 { 92 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); 93 struct phonet_device *pnd; 94 95 list_for_each_entry_rcu(pnd, &pndevs->list, list) { 96 if (pnd->netdev == dev) 97 return pnd; 98 } 99 return NULL; 100 } 101 102 static void phonet_device_destroy(struct net_device *dev) 103 { 104 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); 105 struct phonet_device *pnd; 106 107 ASSERT_RTNL(); 108 109 mutex_lock(&pndevs->lock); 110 pnd = __phonet_get(dev); 111 if (pnd) 112 list_del_rcu(&pnd->list); 113 mutex_unlock(&pndevs->lock); 114 115 if (pnd) { 116 u8 addr; 117 118 for_each_set_bit(addr, pnd->addrs, 64) 119 phonet_address_notify(RTM_DELADDR, dev, addr); 120 kfree(pnd); 121 } 122 } 123 124 struct net_device *phonet_device_get(struct net *net) 125 { 126 struct phonet_device_list *pndevs = phonet_device_list(net); 127 struct phonet_device *pnd; 128 struct net_device *dev = NULL; 129 130 rcu_read_lock(); 131 list_for_each_entry_rcu(pnd, &pndevs->list, list) { 132 dev = pnd->netdev; 133 BUG_ON(!dev); 134 135 if ((dev->reg_state == NETREG_REGISTERED) && 136 ((pnd->netdev->flags & IFF_UP)) == IFF_UP) 137 break; 138 dev = NULL; 139 } 140 if (dev) 141 dev_hold(dev); 142 rcu_read_unlock(); 143 return dev; 144 } 145 146 int phonet_address_add(struct net_device *dev, u8 addr) 147 { 148 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); 149 struct phonet_device *pnd; 150 int err = 0; 151 152 mutex_lock(&pndevs->lock); 153 /* Find or create Phonet-specific device data */ 154 pnd = __phonet_get(dev); 155 if (pnd == NULL) 156 pnd = __phonet_device_alloc(dev); 157 if (unlikely(pnd == NULL)) 158 err = -ENOMEM; 159 else if (test_and_set_bit(addr >> 2, pnd->addrs)) 160 err = -EEXIST; 161 mutex_unlock(&pndevs->lock); 162 return err; 163 } 164 165 int phonet_address_del(struct net_device *dev, u8 addr) 166 { 167 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); 168 struct phonet_device *pnd; 169 int err = 0; 170 171 mutex_lock(&pndevs->lock); 172 pnd = __phonet_get(dev); 173 if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) { 174 err = -EADDRNOTAVAIL; 175 pnd = NULL; 176 } else if (bitmap_empty(pnd->addrs, 64)) 177 list_del_rcu(&pnd->list); 178 else 179 pnd = NULL; 180 mutex_unlock(&pndevs->lock); 181 182 if (pnd) 183 kfree_rcu(pnd, rcu); 184 185 return err; 186 } 187 188 /* Gets a source address toward a destination, through a interface. */ 189 u8 phonet_address_get(struct net_device *dev, u8 daddr) 190 { 191 struct phonet_device *pnd; 192 u8 saddr; 193 194 rcu_read_lock(); 195 pnd = __phonet_get_rcu(dev); 196 if (pnd) { 197 BUG_ON(bitmap_empty(pnd->addrs, 64)); 198 199 /* Use same source address as destination, if possible */ 200 if (test_bit(daddr >> 2, pnd->addrs)) 201 saddr = daddr; 202 else 203 saddr = find_first_bit(pnd->addrs, 64) << 2; 204 } else 205 saddr = PN_NO_ADDR; 206 rcu_read_unlock(); 207 208 if (saddr == PN_NO_ADDR) { 209 /* Fallback to another device */ 210 struct net_device *def_dev; 211 212 def_dev = phonet_device_get(dev_net(dev)); 213 if (def_dev) { 214 if (def_dev != dev) 215 saddr = phonet_address_get(def_dev, daddr); 216 dev_put(def_dev); 217 } 218 } 219 return saddr; 220 } 221 222 int phonet_address_lookup(struct net *net, u8 addr) 223 { 224 struct phonet_device_list *pndevs = phonet_device_list(net); 225 struct phonet_device *pnd; 226 int err = -EADDRNOTAVAIL; 227 228 rcu_read_lock(); 229 list_for_each_entry_rcu(pnd, &pndevs->list, list) { 230 /* Don't allow unregistering devices! */ 231 if ((pnd->netdev->reg_state != NETREG_REGISTERED) || 232 ((pnd->netdev->flags & IFF_UP)) != IFF_UP) 233 continue; 234 235 if (test_bit(addr >> 2, pnd->addrs)) { 236 err = 0; 237 goto found; 238 } 239 } 240 found: 241 rcu_read_unlock(); 242 return err; 243 } 244 245 /* automatically configure a Phonet device, if supported */ 246 static int phonet_device_autoconf(struct net_device *dev) 247 { 248 struct if_phonet_req req; 249 int ret; 250 251 if (!dev->netdev_ops->ndo_do_ioctl) 252 return -EOPNOTSUPP; 253 254 ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req, 255 SIOCPNGAUTOCONF); 256 if (ret < 0) 257 return ret; 258 259 ASSERT_RTNL(); 260 ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device); 261 if (ret) 262 return ret; 263 phonet_address_notify(RTM_NEWADDR, dev, 264 req.ifr_phonet_autoconf.device); 265 return 0; 266 } 267 268 static void phonet_route_autodel(struct net_device *dev) 269 { 270 struct phonet_net *pnn = phonet_pernet(dev_net(dev)); 271 unsigned int i; 272 DECLARE_BITMAP(deleted, 64); 273 274 /* Remove left-over Phonet routes */ 275 bitmap_zero(deleted, 64); 276 mutex_lock(&pnn->routes.lock); 277 for (i = 0; i < 64; i++) 278 if (rcu_access_pointer(pnn->routes.table[i]) == dev) { 279 RCU_INIT_POINTER(pnn->routes.table[i], NULL); 280 set_bit(i, deleted); 281 } 282 mutex_unlock(&pnn->routes.lock); 283 284 if (bitmap_empty(deleted, 64)) 285 return; /* short-circuit RCU */ 286 synchronize_rcu(); 287 for_each_set_bit(i, deleted, 64) { 288 rtm_phonet_notify(RTM_DELROUTE, dev, i); 289 dev_put(dev); 290 } 291 } 292 293 /* notify Phonet of device events */ 294 static int phonet_device_notify(struct notifier_block *me, unsigned long what, 295 void *ptr) 296 { 297 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 298 299 switch (what) { 300 case NETDEV_REGISTER: 301 if (dev->type == ARPHRD_PHONET) 302 phonet_device_autoconf(dev); 303 break; 304 case NETDEV_UNREGISTER: 305 phonet_device_destroy(dev); 306 phonet_route_autodel(dev); 307 break; 308 } 309 return 0; 310 311 } 312 313 static struct notifier_block phonet_device_notifier = { 314 .notifier_call = phonet_device_notify, 315 .priority = 0, 316 }; 317 318 /* Per-namespace Phonet devices handling */ 319 static int __net_init phonet_init_net(struct net *net) 320 { 321 struct phonet_net *pnn = phonet_pernet(net); 322 323 if (!proc_create("phonet", 0, net->proc_net, &pn_sock_seq_fops)) 324 return -ENOMEM; 325 326 INIT_LIST_HEAD(&pnn->pndevs.list); 327 mutex_init(&pnn->pndevs.lock); 328 mutex_init(&pnn->routes.lock); 329 return 0; 330 } 331 332 static void __net_exit phonet_exit_net(struct net *net) 333 { 334 struct phonet_net *pnn = phonet_pernet(net); 335 336 remove_proc_entry("phonet", net->proc_net); 337 WARN_ON_ONCE(!list_empty(&pnn->pndevs.list)); 338 } 339 340 static struct pernet_operations phonet_net_ops = { 341 .init = phonet_init_net, 342 .exit = phonet_exit_net, 343 .id = &phonet_net_id, 344 .size = sizeof(struct phonet_net), 345 }; 346 347 /* Initialize Phonet devices list */ 348 int __init phonet_device_init(void) 349 { 350 int err = register_pernet_subsys(&phonet_net_ops); 351 if (err) 352 return err; 353 354 proc_create("pnresource", 0, init_net.proc_net, &pn_res_seq_fops); 355 register_netdevice_notifier(&phonet_device_notifier); 356 err = phonet_netlink_register(); 357 if (err) 358 phonet_device_exit(); 359 return err; 360 } 361 362 void phonet_device_exit(void) 363 { 364 rtnl_unregister_all(PF_PHONET); 365 unregister_netdevice_notifier(&phonet_device_notifier); 366 unregister_pernet_subsys(&phonet_net_ops); 367 remove_proc_entry("pnresource", init_net.proc_net); 368 } 369 370 int phonet_route_add(struct net_device *dev, u8 daddr) 371 { 372 struct phonet_net *pnn = phonet_pernet(dev_net(dev)); 373 struct phonet_routes *routes = &pnn->routes; 374 int err = -EEXIST; 375 376 daddr = daddr >> 2; 377 mutex_lock(&routes->lock); 378 if (routes->table[daddr] == NULL) { 379 rcu_assign_pointer(routes->table[daddr], dev); 380 dev_hold(dev); 381 err = 0; 382 } 383 mutex_unlock(&routes->lock); 384 return err; 385 } 386 387 int phonet_route_del(struct net_device *dev, u8 daddr) 388 { 389 struct phonet_net *pnn = phonet_pernet(dev_net(dev)); 390 struct phonet_routes *routes = &pnn->routes; 391 392 daddr = daddr >> 2; 393 mutex_lock(&routes->lock); 394 if (rcu_access_pointer(routes->table[daddr]) == dev) 395 RCU_INIT_POINTER(routes->table[daddr], NULL); 396 else 397 dev = NULL; 398 mutex_unlock(&routes->lock); 399 400 if (!dev) 401 return -ENOENT; 402 synchronize_rcu(); 403 dev_put(dev); 404 return 0; 405 } 406 407 struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr) 408 { 409 struct phonet_net *pnn = phonet_pernet(net); 410 struct phonet_routes *routes = &pnn->routes; 411 struct net_device *dev; 412 413 daddr >>= 2; 414 dev = rcu_dereference(routes->table[daddr]); 415 return dev; 416 } 417 418 struct net_device *phonet_route_output(struct net *net, u8 daddr) 419 { 420 struct phonet_net *pnn = phonet_pernet(net); 421 struct phonet_routes *routes = &pnn->routes; 422 struct net_device *dev; 423 424 daddr >>= 2; 425 rcu_read_lock(); 426 dev = rcu_dereference(routes->table[daddr]); 427 if (dev) 428 dev_hold(dev); 429 rcu_read_unlock(); 430 431 if (!dev) 432 dev = phonet_device_get(net); /* Default route */ 433 return dev; 434 } 435