net: Simplify phonet pernet operations.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / phonet / pn_dev.c
blobbc4a33bf2d3d9ec17ab5188d695f345bc9c7cb12
1 /*
2 * File: pn_dev.c
4 * Phonet network device
6 * Copyright (C) 2008 Nokia Corporation.
8 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
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.
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.
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
26 #include <linux/kernel.h>
27 #include <linux/net.h>
28 #include <linux/netdevice.h>
29 #include <linux/phonet.h>
30 #include <linux/proc_fs.h>
31 #include <linux/if_arp.h>
32 #include <net/sock.h>
33 #include <net/netns/generic.h>
34 #include <net/phonet/pn_dev.h>
36 struct phonet_routes {
37 struct mutex lock;
38 struct net_device *table[64];
41 struct phonet_net {
42 struct phonet_device_list pndevs;
43 struct phonet_routes routes;
46 int phonet_net_id __read_mostly;
48 struct phonet_device_list *phonet_device_list(struct net *net)
50 struct phonet_net *pnn = net_generic(net, phonet_net_id);
51 return &pnn->pndevs;
54 /* Allocate new Phonet device. */
55 static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
57 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
58 struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
59 if (pnd == NULL)
60 return NULL;
61 pnd->netdev = dev;
62 bitmap_zero(pnd->addrs, 64);
64 BUG_ON(!mutex_is_locked(&pndevs->lock));
65 list_add_rcu(&pnd->list, &pndevs->list);
66 return pnd;
69 static struct phonet_device *__phonet_get(struct net_device *dev)
71 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
72 struct phonet_device *pnd;
74 BUG_ON(!mutex_is_locked(&pndevs->lock));
75 list_for_each_entry(pnd, &pndevs->list, list) {
76 if (pnd->netdev == dev)
77 return pnd;
79 return NULL;
82 static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
84 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
85 struct phonet_device *pnd;
87 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
88 if (pnd->netdev == dev)
89 return pnd;
91 return NULL;
94 static void phonet_device_destroy(struct net_device *dev)
96 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
97 struct phonet_device *pnd;
99 ASSERT_RTNL();
101 mutex_lock(&pndevs->lock);
102 pnd = __phonet_get(dev);
103 if (pnd)
104 list_del_rcu(&pnd->list);
105 mutex_unlock(&pndevs->lock);
107 if (pnd) {
108 u8 addr;
110 for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
111 addr = find_next_bit(pnd->addrs, 64, 1+addr))
112 phonet_address_notify(RTM_DELADDR, dev, addr);
113 kfree(pnd);
117 struct net_device *phonet_device_get(struct net *net)
119 struct phonet_device_list *pndevs = phonet_device_list(net);
120 struct phonet_device *pnd;
121 struct net_device *dev = NULL;
123 rcu_read_lock();
124 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
125 dev = pnd->netdev;
126 BUG_ON(!dev);
128 if ((dev->reg_state == NETREG_REGISTERED) &&
129 ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
130 break;
131 dev = NULL;
133 if (dev)
134 dev_hold(dev);
135 rcu_read_unlock();
136 return dev;
139 int phonet_address_add(struct net_device *dev, u8 addr)
141 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
142 struct phonet_device *pnd;
143 int err = 0;
145 mutex_lock(&pndevs->lock);
146 /* Find or create Phonet-specific device data */
147 pnd = __phonet_get(dev);
148 if (pnd == NULL)
149 pnd = __phonet_device_alloc(dev);
150 if (unlikely(pnd == NULL))
151 err = -ENOMEM;
152 else if (test_and_set_bit(addr >> 2, pnd->addrs))
153 err = -EEXIST;
154 mutex_unlock(&pndevs->lock);
155 return err;
158 int phonet_address_del(struct net_device *dev, u8 addr)
160 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
161 struct phonet_device *pnd;
162 int err = 0;
164 mutex_lock(&pndevs->lock);
165 pnd = __phonet_get(dev);
166 if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
167 err = -EADDRNOTAVAIL;
168 pnd = NULL;
169 } else if (bitmap_empty(pnd->addrs, 64))
170 list_del_rcu(&pnd->list);
171 else
172 pnd = NULL;
173 mutex_unlock(&pndevs->lock);
175 if (pnd) {
176 synchronize_rcu();
177 kfree(pnd);
179 return err;
182 /* Gets a source address toward a destination, through a interface. */
183 u8 phonet_address_get(struct net_device *dev, u8 daddr)
185 struct phonet_device *pnd;
186 u8 saddr;
188 rcu_read_lock();
189 pnd = __phonet_get_rcu(dev);
190 if (pnd) {
191 BUG_ON(bitmap_empty(pnd->addrs, 64));
193 /* Use same source address as destination, if possible */
194 if (test_bit(daddr >> 2, pnd->addrs))
195 saddr = daddr;
196 else
197 saddr = find_first_bit(pnd->addrs, 64) << 2;
198 } else
199 saddr = PN_NO_ADDR;
200 rcu_read_unlock();
202 if (saddr == PN_NO_ADDR) {
203 /* Fallback to another device */
204 struct net_device *def_dev;
206 def_dev = phonet_device_get(dev_net(dev));
207 if (def_dev) {
208 if (def_dev != dev)
209 saddr = phonet_address_get(def_dev, daddr);
210 dev_put(def_dev);
213 return saddr;
216 int phonet_address_lookup(struct net *net, u8 addr)
218 struct phonet_device_list *pndevs = phonet_device_list(net);
219 struct phonet_device *pnd;
220 int err = -EADDRNOTAVAIL;
222 rcu_read_lock();
223 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
224 /* Don't allow unregistering devices! */
225 if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
226 ((pnd->netdev->flags & IFF_UP)) != IFF_UP)
227 continue;
229 if (test_bit(addr >> 2, pnd->addrs)) {
230 err = 0;
231 goto found;
234 found:
235 rcu_read_unlock();
236 return err;
239 /* automatically configure a Phonet device, if supported */
240 static int phonet_device_autoconf(struct net_device *dev)
242 struct if_phonet_req req;
243 int ret;
245 if (!dev->netdev_ops->ndo_do_ioctl)
246 return -EOPNOTSUPP;
248 ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
249 SIOCPNGAUTOCONF);
250 if (ret < 0)
251 return ret;
253 ASSERT_RTNL();
254 ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
255 if (ret)
256 return ret;
257 phonet_address_notify(RTM_NEWADDR, dev,
258 req.ifr_phonet_autoconf.device);
259 return 0;
262 static void phonet_route_autodel(struct net_device *dev)
264 struct phonet_net *pnn = net_generic(dev_net(dev), phonet_net_id);
265 unsigned i;
266 DECLARE_BITMAP(deleted, 64);
268 /* Remove left-over Phonet routes */
269 bitmap_zero(deleted, 64);
270 mutex_lock(&pnn->routes.lock);
271 for (i = 0; i < 64; i++)
272 if (dev == pnn->routes.table[i]) {
273 rcu_assign_pointer(pnn->routes.table[i], NULL);
274 set_bit(i, deleted);
276 mutex_unlock(&pnn->routes.lock);
278 if (bitmap_empty(deleted, 64))
279 return; /* short-circuit RCU */
280 synchronize_rcu();
281 for (i = find_first_bit(deleted, 64); i < 64;
282 i = find_next_bit(deleted, 64, i + 1)) {
283 rtm_phonet_notify(RTM_DELROUTE, dev, i);
284 dev_put(dev);
288 /* notify Phonet of device events */
289 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
290 void *arg)
292 struct net_device *dev = arg;
294 switch (what) {
295 case NETDEV_REGISTER:
296 if (dev->type == ARPHRD_PHONET)
297 phonet_device_autoconf(dev);
298 break;
299 case NETDEV_UNREGISTER:
300 phonet_device_destroy(dev);
301 phonet_route_autodel(dev);
302 break;
304 return 0;
308 static struct notifier_block phonet_device_notifier = {
309 .notifier_call = phonet_device_notify,
310 .priority = 0,
313 /* Per-namespace Phonet devices handling */
314 static int phonet_init_net(struct net *net)
316 struct phonet_net *pnn = net_generic(net, phonet_net_id);
318 if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops))
319 return -ENOMEM;
321 INIT_LIST_HEAD(&pnn->pndevs.list);
322 mutex_init(&pnn->pndevs.lock);
323 mutex_init(&pnn->routes.lock);
324 return 0;
327 static void phonet_exit_net(struct net *net)
329 struct phonet_net *pnn = net_generic(net, phonet_net_id);
330 struct net_device *dev;
331 unsigned i;
333 rtnl_lock();
334 for_each_netdev(net, dev)
335 phonet_device_destroy(dev);
337 for (i = 0; i < 64; i++) {
338 dev = pnn->routes.table[i];
339 if (dev) {
340 rtm_phonet_notify(RTM_DELROUTE, dev, i);
341 dev_put(dev);
344 rtnl_unlock();
346 proc_net_remove(net, "phonet");
349 static struct pernet_operations phonet_net_ops = {
350 .init = phonet_init_net,
351 .exit = phonet_exit_net,
352 .id = &phonet_net_id,
353 .size = sizeof(struct phonet_net),
356 /* Initialize Phonet devices list */
357 int __init phonet_device_init(void)
359 int err = register_pernet_device(&phonet_net_ops);
360 if (err)
361 return err;
363 register_netdevice_notifier(&phonet_device_notifier);
364 err = phonet_netlink_register();
365 if (err)
366 phonet_device_exit();
367 return err;
370 void phonet_device_exit(void)
372 rtnl_unregister_all(PF_PHONET);
373 unregister_netdevice_notifier(&phonet_device_notifier);
374 unregister_pernet_device(&phonet_net_ops);
377 int phonet_route_add(struct net_device *dev, u8 daddr)
379 struct phonet_net *pnn = net_generic(dev_net(dev), phonet_net_id);
380 struct phonet_routes *routes = &pnn->routes;
381 int err = -EEXIST;
383 daddr = daddr >> 2;
384 mutex_lock(&routes->lock);
385 if (routes->table[daddr] == NULL) {
386 rcu_assign_pointer(routes->table[daddr], dev);
387 dev_hold(dev);
388 err = 0;
390 mutex_unlock(&routes->lock);
391 return err;
394 int phonet_route_del(struct net_device *dev, u8 daddr)
396 struct phonet_net *pnn = net_generic(dev_net(dev), phonet_net_id);
397 struct phonet_routes *routes = &pnn->routes;
399 daddr = daddr >> 2;
400 mutex_lock(&routes->lock);
401 if (dev == routes->table[daddr])
402 rcu_assign_pointer(routes->table[daddr], NULL);
403 else
404 dev = NULL;
405 mutex_unlock(&routes->lock);
407 if (!dev)
408 return -ENOENT;
409 synchronize_rcu();
410 dev_put(dev);
411 return 0;
414 struct net_device *phonet_route_get(struct net *net, u8 daddr)
416 struct phonet_net *pnn = net_generic(net, phonet_net_id);
417 struct phonet_routes *routes = &pnn->routes;
418 struct net_device *dev;
420 ASSERT_RTNL(); /* no need to hold the device */
422 daddr >>= 2;
423 rcu_read_lock();
424 dev = rcu_dereference(routes->table[daddr]);
425 rcu_read_unlock();
426 return dev;
429 struct net_device *phonet_route_output(struct net *net, u8 daddr)
431 struct phonet_net *pnn = net_generic(net, phonet_net_id);
432 struct phonet_routes *routes = &pnn->routes;
433 struct net_device *dev;
435 daddr >>= 2;
436 rcu_read_lock();
437 dev = rcu_dereference(routes->table[daddr]);
438 if (dev)
439 dev_hold(dev);
440 rcu_read_unlock();
442 if (!dev)
443 dev = phonet_device_get(net); /* Default route */
444 return dev;