Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 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 | * RĂ©mi 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 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 | remove_proc_entry("phonet", net->proc_net); |
| 335 | } |
| 336 | |
| 337 | static struct pernet_operations phonet_net_ops = { |
| 338 | .init = phonet_init_net, |
| 339 | .exit = phonet_exit_net, |
| 340 | .id = &phonet_net_id, |
| 341 | .size = sizeof(struct phonet_net), |
| 342 | }; |
| 343 | |
| 344 | /* Initialize Phonet devices list */ |
| 345 | int __init phonet_device_init(void) |
| 346 | { |
| 347 | int err = register_pernet_subsys(&phonet_net_ops); |
| 348 | if (err) |
| 349 | return err; |
| 350 | |
| 351 | proc_create("pnresource", 0, init_net.proc_net, &pn_res_seq_fops); |
| 352 | register_netdevice_notifier(&phonet_device_notifier); |
| 353 | err = phonet_netlink_register(); |
| 354 | if (err) |
| 355 | phonet_device_exit(); |
| 356 | return err; |
| 357 | } |
| 358 | |
| 359 | void phonet_device_exit(void) |
| 360 | { |
| 361 | rtnl_unregister_all(PF_PHONET); |
| 362 | unregister_netdevice_notifier(&phonet_device_notifier); |
| 363 | unregister_pernet_subsys(&phonet_net_ops); |
| 364 | remove_proc_entry("pnresource", init_net.proc_net); |
| 365 | } |
| 366 | |
| 367 | int phonet_route_add(struct net_device *dev, u8 daddr) |
| 368 | { |
| 369 | struct phonet_net *pnn = phonet_pernet(dev_net(dev)); |
| 370 | struct phonet_routes *routes = &pnn->routes; |
| 371 | int err = -EEXIST; |
| 372 | |
| 373 | daddr = daddr >> 2; |
| 374 | mutex_lock(&routes->lock); |
| 375 | if (routes->table[daddr] == NULL) { |
| 376 | rcu_assign_pointer(routes->table[daddr], dev); |
| 377 | dev_hold(dev); |
| 378 | err = 0; |
| 379 | } |
| 380 | mutex_unlock(&routes->lock); |
| 381 | return err; |
| 382 | } |
| 383 | |
| 384 | int phonet_route_del(struct net_device *dev, u8 daddr) |
| 385 | { |
| 386 | struct phonet_net *pnn = phonet_pernet(dev_net(dev)); |
| 387 | struct phonet_routes *routes = &pnn->routes; |
| 388 | |
| 389 | daddr = daddr >> 2; |
| 390 | mutex_lock(&routes->lock); |
| 391 | if (rcu_access_pointer(routes->table[daddr]) == dev) |
| 392 | RCU_INIT_POINTER(routes->table[daddr], NULL); |
| 393 | else |
| 394 | dev = NULL; |
| 395 | mutex_unlock(&routes->lock); |
| 396 | |
| 397 | if (!dev) |
| 398 | return -ENOENT; |
| 399 | synchronize_rcu(); |
| 400 | dev_put(dev); |
| 401 | return 0; |
| 402 | } |
| 403 | |
| 404 | struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr) |
| 405 | { |
| 406 | struct phonet_net *pnn = phonet_pernet(net); |
| 407 | struct phonet_routes *routes = &pnn->routes; |
| 408 | struct net_device *dev; |
| 409 | |
| 410 | daddr >>= 2; |
| 411 | dev = rcu_dereference(routes->table[daddr]); |
| 412 | return dev; |
| 413 | } |
| 414 | |
| 415 | struct net_device *phonet_route_output(struct net *net, u8 daddr) |
| 416 | { |
| 417 | struct phonet_net *pnn = phonet_pernet(net); |
| 418 | struct phonet_routes *routes = &pnn->routes; |
| 419 | struct net_device *dev; |
| 420 | |
| 421 | daddr >>= 2; |
| 422 | rcu_read_lock(); |
| 423 | dev = rcu_dereference(routes->table[daddr]); |
| 424 | if (dev) |
| 425 | dev_hold(dev); |
| 426 | rcu_read_unlock(); |
| 427 | |
| 428 | if (!dev) |
| 429 | dev = phonet_device_get(net); /* Default route */ |
| 430 | return dev; |
| 431 | } |