Phonet: back-end for autoconfigured addresses
[linux-2.6.git] / net / phonet / pn_dev.c
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>
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>
35
36 struct phonet_net {
37         struct phonet_device_list pndevs;
38 };
39
40 int phonet_net_id;
41
42 struct phonet_device_list *phonet_device_list(struct net *net)
43 {
44         struct phonet_net *pnn = net_generic(net, phonet_net_id);
45         return &pnn->pndevs;
46 }
47
48 /* Allocate new Phonet device. */
49 static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
50 {
51         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
52         struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
53         if (pnd == NULL)
54                 return NULL;
55         pnd->netdev = dev;
56         bitmap_zero(pnd->addrs, 64);
57
58         list_add(&pnd->list, &pndevs->list);
59         return pnd;
60 }
61
62 static struct phonet_device *__phonet_get(struct net_device *dev)
63 {
64         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
65         struct phonet_device *pnd;
66
67         list_for_each_entry(pnd, &pndevs->list, list) {
68                 if (pnd->netdev == dev)
69                         return pnd;
70         }
71         return NULL;
72 }
73
74 static void phonet_device_destroy(struct net_device *dev)
75 {
76         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
77         struct phonet_device *pnd;
78
79         ASSERT_RTNL();
80
81         spin_lock_bh(&pndevs->lock);
82         pnd = __phonet_get(dev);
83         if (pnd)
84                 list_del(&pnd->list);
85         spin_unlock_bh(&pndevs->lock);
86
87         if (pnd) {
88                 u8 addr;
89
90                 for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
91                         addr = find_next_bit(pnd->addrs, 64, 1+addr))
92                         phonet_address_notify(RTM_DELADDR, dev, addr);
93                 kfree(pnd);
94         }
95 }
96
97 struct net_device *phonet_device_get(struct net *net)
98 {
99         struct phonet_device_list *pndevs = phonet_device_list(net);
100         struct phonet_device *pnd;
101         struct net_device *dev = NULL;
102
103         spin_lock_bh(&pndevs->lock);
104         list_for_each_entry(pnd, &pndevs->list, list) {
105                 dev = pnd->netdev;
106                 BUG_ON(!dev);
107
108                 if ((dev->reg_state == NETREG_REGISTERED) &&
109                         ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
110                         break;
111                 dev = NULL;
112         }
113         if (dev)
114                 dev_hold(dev);
115         spin_unlock_bh(&pndevs->lock);
116         return dev;
117 }
118
119 int phonet_address_add(struct net_device *dev, u8 addr)
120 {
121         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
122         struct phonet_device *pnd;
123         int err = 0;
124
125         spin_lock_bh(&pndevs->lock);
126         /* Find or create Phonet-specific device data */
127         pnd = __phonet_get(dev);
128         if (pnd == NULL)
129                 pnd = __phonet_device_alloc(dev);
130         if (unlikely(pnd == NULL))
131                 err = -ENOMEM;
132         else if (test_and_set_bit(addr >> 2, pnd->addrs))
133                 err = -EEXIST;
134         spin_unlock_bh(&pndevs->lock);
135         return err;
136 }
137
138 int phonet_address_del(struct net_device *dev, u8 addr)
139 {
140         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
141         struct phonet_device *pnd;
142         int err = 0;
143
144         spin_lock_bh(&pndevs->lock);
145         pnd = __phonet_get(dev);
146         if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
147                 err = -EADDRNOTAVAIL;
148         else if (bitmap_empty(pnd->addrs, 64)) {
149                 list_del(&pnd->list);
150                 kfree(pnd);
151         }
152         spin_unlock_bh(&pndevs->lock);
153         return err;
154 }
155
156 /* Gets a source address toward a destination, through a interface. */
157 u8 phonet_address_get(struct net_device *dev, u8 addr)
158 {
159         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
160         struct phonet_device *pnd;
161
162         spin_lock_bh(&pndevs->lock);
163         pnd = __phonet_get(dev);
164         if (pnd) {
165                 BUG_ON(bitmap_empty(pnd->addrs, 64));
166
167                 /* Use same source address as destination, if possible */
168                 if (!test_bit(addr >> 2, pnd->addrs))
169                         addr = find_first_bit(pnd->addrs, 64) << 2;
170         } else
171                 addr = PN_NO_ADDR;
172         spin_unlock_bh(&pndevs->lock);
173         return addr;
174 }
175
176 int phonet_address_lookup(struct net *net, u8 addr)
177 {
178         struct phonet_device_list *pndevs = phonet_device_list(net);
179         struct phonet_device *pnd;
180         int err = -EADDRNOTAVAIL;
181
182         spin_lock_bh(&pndevs->lock);
183         list_for_each_entry(pnd, &pndevs->list, list) {
184                 /* Don't allow unregistering devices! */
185                 if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
186                                 ((pnd->netdev->flags & IFF_UP)) != IFF_UP)
187                         continue;
188
189                 if (test_bit(addr >> 2, pnd->addrs)) {
190                         err = 0;
191                         goto found;
192                 }
193         }
194 found:
195         spin_unlock_bh(&pndevs->lock);
196         return err;
197 }
198
199 /* automatically configure a Phonet device, if supported */
200 static int phonet_device_autoconf(struct net_device *dev)
201 {
202         struct if_phonet_req req;
203         int ret;
204
205         if (!dev->netdev_ops->ndo_do_ioctl)
206                 return -EOPNOTSUPP;
207
208         ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
209                                                 SIOCPNGAUTOCONF);
210         if (ret < 0)
211                 return ret;
212         return phonet_address_add(dev, req.ifr_phonet_autoconf.device);
213 }
214
215 /* notify Phonet of device events */
216 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
217                                 void *arg)
218 {
219         struct net_device *dev = arg;
220
221         switch (what) {
222         case NETDEV_REGISTER:
223                 if (dev->type == ARPHRD_PHONET)
224                         phonet_device_autoconf(dev);
225                 break;
226         case NETDEV_UNREGISTER:
227                 phonet_device_destroy(dev);
228                 break;
229         }
230         return 0;
231
232 }
233
234 static struct notifier_block phonet_device_notifier = {
235         .notifier_call = phonet_device_notify,
236         .priority = 0,
237 };
238
239 /* Per-namespace Phonet devices handling */
240 static int phonet_init_net(struct net *net)
241 {
242         struct phonet_net *pnn = kmalloc(sizeof(*pnn), GFP_KERNEL);
243         if (!pnn)
244                 return -ENOMEM;
245
246         if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops)) {
247                 kfree(pnn);
248                 return -ENOMEM;
249         }
250
251         INIT_LIST_HEAD(&pnn->pndevs.list);
252         spin_lock_init(&pnn->pndevs.lock);
253         net_assign_generic(net, phonet_net_id, pnn);
254         return 0;
255 }
256
257 static void phonet_exit_net(struct net *net)
258 {
259         struct phonet_net *pnn = net_generic(net, phonet_net_id);
260         struct net_device *dev;
261
262         rtnl_lock();
263         for_each_netdev(net, dev)
264                 phonet_device_destroy(dev);
265         rtnl_unlock();
266
267         proc_net_remove(net, "phonet");
268         kfree(pnn);
269 }
270
271 static struct pernet_operations phonet_net_ops = {
272         .init = phonet_init_net,
273         .exit = phonet_exit_net,
274 };
275
276 /* Initialize Phonet devices list */
277 int __init phonet_device_init(void)
278 {
279         int err = register_pernet_gen_device(&phonet_net_id, &phonet_net_ops);
280         if (err)
281                 return err;
282
283         register_netdevice_notifier(&phonet_device_notifier);
284         err = phonet_netlink_register();
285         if (err)
286                 phonet_device_exit();
287         return err;
288 }
289
290 void phonet_device_exit(void)
291 {
292         rtnl_unregister_all(PF_PHONET);
293         unregister_netdevice_notifier(&phonet_device_notifier);
294         unregister_pernet_gen_device(phonet_net_id, &phonet_net_ops);
295 }