rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / phonet / pn_dev.c
CommitLineData
f8ff6028
RDC
1/*
2 * File: pn_dev.c
3 *
4 * Phonet network device
5 *
6 * Copyright (C) 2008 Nokia Corporation.
7 *
8 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
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>
5a0e3ad6 28#include <linux/slab.h>
f8ff6028
RDC
29#include <linux/netdevice.h>
30#include <linux/phonet.h>
421d20a3 31#include <linux/proc_fs.h>
f5bb1c55 32#include <linux/if_arp.h>
f8ff6028 33#include <net/sock.h>
9a3b7a42 34#include <net/netns/generic.h>
f8ff6028
RDC
35#include <net/phonet/pn_dev.h>
36
55748ac0 37struct phonet_routes {
88880135 38 struct mutex lock;
55748ac0
RDC
39 struct net_device *table[64];
40};
41
9a3b7a42 42struct phonet_net {
43 struct phonet_device_list pndevs;
55748ac0 44 struct phonet_routes routes;
f8ff6028
RDC
45};
46
f99189b1 47int phonet_net_id __read_mostly;
9a3b7a42 48
0db3f0f4
JP
49static struct phonet_net *phonet_pernet(struct net *net)
50{
51 BUG_ON(!net);
52
53 return net_generic(net, phonet_net_id);
54}
55
9a3b7a42 56struct phonet_device_list *phonet_device_list(struct net *net)
57{
0db3f0f4 58 struct phonet_net *pnn = phonet_pernet(net);
9a3b7a42 59 return &pnn->pndevs;
60}
61
f8ff6028
RDC
62/* Allocate new Phonet device. */
63static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
64{
9a3b7a42 65 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
f8ff6028
RDC
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
eeb74a9d
RDC
72 BUG_ON(!mutex_is_locked(&pndevs->lock));
73 list_add_rcu(&pnd->list, &pndevs->list);
f8ff6028
RDC
74 return pnd;
75}
76
77static struct phonet_device *__phonet_get(struct net_device *dev)
78{
9a3b7a42 79 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
f8ff6028
RDC
80 struct phonet_device *pnd;
81
eeb74a9d 82 BUG_ON(!mutex_is_locked(&pndevs->lock));
9a3b7a42 83 list_for_each_entry(pnd, &pndevs->list, list) {
f8ff6028
RDC
84 if (pnd->netdev == dev)
85 return pnd;
86 }
87 return NULL;
88}
89
eeb74a9d
RDC
90static 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
2be6fa4c 102static void phonet_device_destroy(struct net_device *dev)
f8ff6028 103{
2be6fa4c
RDC
104 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
105 struct phonet_device *pnd;
106
107 ASSERT_RTNL();
108
eeb74a9d 109 mutex_lock(&pndevs->lock);
2be6fa4c
RDC
110 pnd = __phonet_get(dev);
111 if (pnd)
eeb74a9d
RDC
112 list_del_rcu(&pnd->list);
113 mutex_unlock(&pndevs->lock);
2be6fa4c
RDC
114
115 if (pnd) {
116 u8 addr;
117
a1ca14ac 118 for_each_set_bit(addr, pnd->addrs, 64)
2be6fa4c
RDC
119 phonet_address_notify(RTM_DELADDR, dev, addr);
120 kfree(pnd);
121 }
f8ff6028
RDC
122}
123
124struct net_device *phonet_device_get(struct net *net)
125{
9a3b7a42 126 struct phonet_device_list *pndevs = phonet_device_list(net);
f8ff6028 127 struct phonet_device *pnd;
59e57f44 128 struct net_device *dev = NULL;
f8ff6028 129
eeb74a9d
RDC
130 rcu_read_lock();
131 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
f8ff6028
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132 dev = pnd->netdev;
133 BUG_ON(!dev);
134
9a3b7a42 135 if ((dev->reg_state == NETREG_REGISTERED) &&
f8ff6028
RDC
136 ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
137 break;
138 dev = NULL;
139 }
140 if (dev)
141 dev_hold(dev);
eeb74a9d 142 rcu_read_unlock();
f8ff6028
RDC
143 return dev;
144}
145
146int phonet_address_add(struct net_device *dev, u8 addr)
147{
9a3b7a42 148 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
f8ff6028
RDC
149 struct phonet_device *pnd;
150 int err = 0;
151
eeb74a9d 152 mutex_lock(&pndevs->lock);
f8ff6028
RDC
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;
eeb74a9d 161 mutex_unlock(&pndevs->lock);
f8ff6028
RDC
162 return err;
163}
164
165int phonet_address_del(struct net_device *dev, u8 addr)
166{
9a3b7a42 167 struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
f8ff6028
RDC
168 struct phonet_device *pnd;
169 int err = 0;
170
eeb74a9d 171 mutex_lock(&pndevs->lock);
f8ff6028 172 pnd = __phonet_get(dev);
eeb74a9d 173 if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
f8ff6028 174 err = -EADDRNOTAVAIL;
eeb74a9d
RDC
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
88e7594a 182 if (pnd)
7e113a9c 183 kfree_rcu(pnd, rcu);
88e7594a 184
f8ff6028
RDC
185 return err;
186}
187
188/* Gets a source address toward a destination, through a interface. */
55748ac0 189u8 phonet_address_get(struct net_device *dev, u8 daddr)
f8ff6028
RDC
190{
191 struct phonet_device *pnd;
55748ac0 192 u8 saddr;
f8ff6028 193
eeb74a9d
RDC
194 rcu_read_lock();
195 pnd = __phonet_get_rcu(dev);
f8ff6028
RDC
196 if (pnd) {
197 BUG_ON(bitmap_empty(pnd->addrs, 64));
198
199 /* Use same source address as destination, if possible */
55748ac0
RDC
200 if (test_bit(daddr >> 2, pnd->addrs))
201 saddr = daddr;
202 else
203 saddr = find_first_bit(pnd->addrs, 64) << 2;
f8ff6028 204 } else
55748ac0 205 saddr = PN_NO_ADDR;
eeb74a9d 206 rcu_read_unlock();
55748ac0
RDC
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;
f8ff6028
RDC
220}
221
52404881 222int phonet_address_lookup(struct net *net, u8 addr)
f8ff6028 223{
9a3b7a42 224 struct phonet_device_list *pndevs = phonet_device_list(net);
f8ff6028 225 struct phonet_device *pnd;
9a3b7a42 226 int err = -EADDRNOTAVAIL;
f8ff6028 227
eeb74a9d
RDC
228 rcu_read_lock();
229 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
f8ff6028
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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)) {
9a3b7a42 236 err = 0;
237 goto found;
f8ff6028
RDC
238 }
239 }
9a3b7a42 240found:
eeb74a9d 241 rcu_read_unlock();
9a3b7a42 242 return err;
f8ff6028
RDC
243}
244
f5bb1c55
RDC
245/* automatically configure a Phonet device, if supported */
246static 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;
b11b5165
RDC
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;
f5bb1c55
RDC
266}
267
f062f41d
RDC
268static void phonet_route_autodel(struct net_device *dev)
269{
0db3f0f4 270 struct phonet_net *pnn = phonet_pernet(dev_net(dev));
f062f41d
RDC
271 unsigned i;
272 DECLARE_BITMAP(deleted, 64);
273
274 /* Remove left-over Phonet routes */
275 bitmap_zero(deleted, 64);
88880135 276 mutex_lock(&pnn->routes.lock);
f062f41d
RDC
277 for (i = 0; i < 64; i++)
278 if (dev == pnn->routes.table[i]) {
a9b3cd7f 279 RCU_INIT_POINTER(pnn->routes.table[i], NULL);
f062f41d 280 set_bit(i, deleted);
f062f41d 281 }
88880135
RDC
282 mutex_unlock(&pnn->routes.lock);
283
284 if (bitmap_empty(deleted, 64))
285 return; /* short-circuit RCU */
286 synchronize_rcu();
6a499b24 287 for_each_set_bit(i, deleted, 64) {
f062f41d 288 rtm_phonet_notify(RTM_DELROUTE, dev, i);
88880135
RDC
289 dev_put(dev);
290 }
f062f41d
RDC
291}
292
f8ff6028
RDC
293/* notify Phonet of device events */
294static int phonet_device_notify(struct notifier_block *me, unsigned long what,
295 void *arg)
296{
297 struct net_device *dev = arg;
298
f5bb1c55
RDC
299 switch (what) {
300 case NETDEV_REGISTER:
301 if (dev->type == ARPHRD_PHONET)
302 phonet_device_autoconf(dev);
303 break;
304 case NETDEV_UNREGISTER:
2be6fa4c 305 phonet_device_destroy(dev);
f062f41d 306 phonet_route_autodel(dev);
f5bb1c55
RDC
307 break;
308 }
f8ff6028
RDC
309 return 0;
310
311}
312
313static struct notifier_block phonet_device_notifier = {
314 .notifier_call = phonet_device_notify,
315 .priority = 0,
316};
317
9a3b7a42 318/* Per-namespace Phonet devices handling */
2c8c1e72 319static int __net_init phonet_init_net(struct net *net)
9a3b7a42 320{
0db3f0f4 321 struct phonet_net *pnn = phonet_pernet(net);
9a3b7a42 322
d2b3eb63 323 if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops))
c1dc13e9 324 return -ENOMEM;
c1dc13e9 325
9a3b7a42 326 INIT_LIST_HEAD(&pnn->pndevs.list);
eeb74a9d 327 mutex_init(&pnn->pndevs.lock);
88880135 328 mutex_init(&pnn->routes.lock);
9a3b7a42 329 return 0;
330}
331
2c8c1e72 332static void __net_exit phonet_exit_net(struct net *net)
9a3b7a42 333{
0db3f0f4 334 struct phonet_net *pnn = phonet_pernet(net);
2be6fa4c 335 struct net_device *dev;
f062f41d 336 unsigned i;
9a3b7a42 337
2be6fa4c
RDC
338 rtnl_lock();
339 for_each_netdev(net, dev)
340 phonet_device_destroy(dev);
f062f41d
RDC
341
342 for (i = 0; i < 64; i++) {
343 dev = pnn->routes.table[i];
344 if (dev) {
345 rtm_phonet_notify(RTM_DELROUTE, dev, i);
346 dev_put(dev);
347 }
348 }
2be6fa4c 349 rtnl_unlock();
c1dc13e9
RDC
350
351 proc_net_remove(net, "phonet");
9a3b7a42 352}
353
354static struct pernet_operations phonet_net_ops = {
355 .init = phonet_init_net,
356 .exit = phonet_exit_net,
d2b3eb63
EB
357 .id = &phonet_net_id,
358 .size = sizeof(struct phonet_net),
9a3b7a42 359};
360
f8ff6028 361/* Initialize Phonet devices list */
76e02cf6 362int __init phonet_device_init(void)
f8ff6028 363{
d2b3eb63 364 int err = register_pernet_device(&phonet_net_ops);
9a3b7a42 365 if (err)
366 return err;
660f706d 367
507215f8 368 proc_net_fops_create(&init_net, "pnresource", 0, &pn_res_seq_fops);
f8ff6028 369 register_netdevice_notifier(&phonet_device_notifier);
660f706d 370 err = phonet_netlink_register();
371 if (err)
372 phonet_device_exit();
373 return err;
f8ff6028
RDC
374}
375
376void phonet_device_exit(void)
377{
f8ff6028 378 rtnl_unregister_all(PF_PHONET);
6530e0fe 379 unregister_netdevice_notifier(&phonet_device_notifier);
d2b3eb63 380 unregister_pernet_device(&phonet_net_ops);
507215f8 381 proc_net_remove(&init_net, "pnresource");
f8ff6028 382}
55748ac0
RDC
383
384int phonet_route_add(struct net_device *dev, u8 daddr)
385{
0db3f0f4 386 struct phonet_net *pnn = phonet_pernet(dev_net(dev));
55748ac0
RDC
387 struct phonet_routes *routes = &pnn->routes;
388 int err = -EEXIST;
389
390 daddr = daddr >> 2;
88880135 391 mutex_lock(&routes->lock);
55748ac0 392 if (routes->table[daddr] == NULL) {
a9b3cd7f 393 RCU_INIT_POINTER(routes->table[daddr], dev);
55748ac0
RDC
394 dev_hold(dev);
395 err = 0;
396 }
88880135 397 mutex_unlock(&routes->lock);
55748ac0
RDC
398 return err;
399}
400
401int phonet_route_del(struct net_device *dev, u8 daddr)
402{
0db3f0f4 403 struct phonet_net *pnn = phonet_pernet(dev_net(dev));
55748ac0 404 struct phonet_routes *routes = &pnn->routes;
55748ac0
RDC
405
406 daddr = daddr >> 2;
88880135
RDC
407 mutex_lock(&routes->lock);
408 if (dev == routes->table[daddr])
a9b3cd7f 409 RCU_INIT_POINTER(routes->table[daddr], NULL);
88880135
RDC
410 else
411 dev = NULL;
412 mutex_unlock(&routes->lock);
413
414 if (!dev)
415 return -ENOENT;
416 synchronize_rcu();
417 dev_put(dev);
418 return 0;
55748ac0
RDC
419}
420
e67f88dd 421struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr)
55748ac0 422{
0db3f0f4 423 struct phonet_net *pnn = phonet_pernet(net);
55748ac0
RDC
424 struct phonet_routes *routes = &pnn->routes;
425 struct net_device *dev;
426
55748ac0 427 daddr >>= 2;
88880135 428 dev = rcu_dereference(routes->table[daddr]);
55748ac0
RDC
429 return dev;
430}
431
432struct net_device *phonet_route_output(struct net *net, u8 daddr)
433{
0db3f0f4 434 struct phonet_net *pnn = phonet_pernet(net);
55748ac0
RDC
435 struct phonet_routes *routes = &pnn->routes;
436 struct net_device *dev;
437
88880135
RDC
438 daddr >>= 2;
439 rcu_read_lock();
440 dev = rcu_dereference(routes->table[daddr]);
55748ac0
RDC
441 if (dev)
442 dev_hold(dev);
88880135 443 rcu_read_unlock();
55748ac0
RDC
444
445 if (!dev)
446 dev = phonet_device_get(net); /* Default route */
447 return dev;
448}