Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6] / 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 <net/sock.h>
31 #include <net/netns/generic.h>
32 #include <net/phonet/pn_dev.h>
33
34 struct phonet_net {
35         struct phonet_device_list pndevs;
36 };
37
38 int phonet_net_id;
39
40 struct phonet_device_list *phonet_device_list(struct net *net)
41 {
42         struct phonet_net *pnn = net_generic(net, phonet_net_id);
43         return &pnn->pndevs;
44 }
45
46 /* Allocate new Phonet device. */
47 static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
48 {
49         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
50         struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
51         if (pnd == NULL)
52                 return NULL;
53         pnd->netdev = dev;
54         bitmap_zero(pnd->addrs, 64);
55
56         list_add(&pnd->list, &pndevs->list);
57         return pnd;
58 }
59
60 static struct phonet_device *__phonet_get(struct net_device *dev)
61 {
62         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
63         struct phonet_device *pnd;
64
65         list_for_each_entry(pnd, &pndevs->list, list) {
66                 if (pnd->netdev == dev)
67                         return pnd;
68         }
69         return NULL;
70 }
71
72 static void phonet_device_destroy(struct net_device *dev)
73 {
74         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
75         struct phonet_device *pnd;
76
77         ASSERT_RTNL();
78
79         spin_lock_bh(&pndevs->lock);
80         pnd = __phonet_get(dev);
81         if (pnd)
82                 list_del(&pnd->list);
83         spin_unlock_bh(&pndevs->lock);
84
85         if (pnd) {
86                 u8 addr;
87
88                 for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
89                         addr = find_next_bit(pnd->addrs, 64, 1+addr))
90                         phonet_address_notify(RTM_DELADDR, dev, addr);
91                 kfree(pnd);
92         }
93 }
94
95 struct net_device *phonet_device_get(struct net *net)
96 {
97         struct phonet_device_list *pndevs = phonet_device_list(net);
98         struct phonet_device *pnd;
99         struct net_device *dev;
100
101         spin_lock_bh(&pndevs->lock);
102         list_for_each_entry(pnd, &pndevs->list, list) {
103                 dev = pnd->netdev;
104                 BUG_ON(!dev);
105
106                 if ((dev->reg_state == NETREG_REGISTERED) &&
107                         ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
108                         break;
109                 dev = NULL;
110         }
111         if (dev)
112                 dev_hold(dev);
113         spin_unlock_bh(&pndevs->lock);
114         return dev;
115 }
116
117 int phonet_address_add(struct net_device *dev, u8 addr)
118 {
119         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
120         struct phonet_device *pnd;
121         int err = 0;
122
123         spin_lock_bh(&pndevs->lock);
124         /* Find or create Phonet-specific device data */
125         pnd = __phonet_get(dev);
126         if (pnd == NULL)
127                 pnd = __phonet_device_alloc(dev);
128         if (unlikely(pnd == NULL))
129                 err = -ENOMEM;
130         else if (test_and_set_bit(addr >> 2, pnd->addrs))
131                 err = -EEXIST;
132         spin_unlock_bh(&pndevs->lock);
133         return err;
134 }
135
136 int phonet_address_del(struct net_device *dev, u8 addr)
137 {
138         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
139         struct phonet_device *pnd;
140         int err = 0;
141
142         spin_lock_bh(&pndevs->lock);
143         pnd = __phonet_get(dev);
144         if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
145                 err = -EADDRNOTAVAIL;
146         else if (bitmap_empty(pnd->addrs, 64)) {
147                 list_del(&pnd->list);
148                 kfree(pnd);
149         }
150         spin_unlock_bh(&pndevs->lock);
151         return err;
152 }
153
154 /* Gets a source address toward a destination, through a interface. */
155 u8 phonet_address_get(struct net_device *dev, u8 addr)
156 {
157         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
158         struct phonet_device *pnd;
159
160         spin_lock_bh(&pndevs->lock);
161         pnd = __phonet_get(dev);
162         if (pnd) {
163                 BUG_ON(bitmap_empty(pnd->addrs, 64));
164
165                 /* Use same source address as destination, if possible */
166                 if (!test_bit(addr >> 2, pnd->addrs))
167                         addr = find_first_bit(pnd->addrs, 64) << 2;
168         } else
169                 addr = PN_NO_ADDR;
170         spin_unlock_bh(&pndevs->lock);
171         return addr;
172 }
173
174 int phonet_address_lookup(struct net *net, u8 addr)
175 {
176         struct phonet_device_list *pndevs = phonet_device_list(net);
177         struct phonet_device *pnd;
178         int err = -EADDRNOTAVAIL;
179
180         spin_lock_bh(&pndevs->lock);
181         list_for_each_entry(pnd, &pndevs->list, list) {
182                 /* Don't allow unregistering devices! */
183                 if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
184                                 ((pnd->netdev->flags & IFF_UP)) != IFF_UP)
185                         continue;
186
187                 if (test_bit(addr >> 2, pnd->addrs)) {
188                         err = 0;
189                         goto found;
190                 }
191         }
192 found:
193         spin_unlock_bh(&pndevs->lock);
194         return err;
195 }
196
197 /* notify Phonet of device events */
198 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
199                                 void *arg)
200 {
201         struct net_device *dev = arg;
202
203         if (what == NETDEV_UNREGISTER)
204                 phonet_device_destroy(dev);
205         return 0;
206
207 }
208
209 static struct notifier_block phonet_device_notifier = {
210         .notifier_call = phonet_device_notify,
211         .priority = 0,
212 };
213
214 /* Per-namespace Phonet devices handling */
215 static int phonet_init_net(struct net *net)
216 {
217         struct phonet_net *pnn = kmalloc(sizeof(*pnn), GFP_KERNEL);
218         if (!pnn)
219                 return -ENOMEM;
220
221         INIT_LIST_HEAD(&pnn->pndevs.list);
222         spin_lock_init(&pnn->pndevs.lock);
223         net_assign_generic(net, phonet_net_id, pnn);
224         return 0;
225 }
226
227 static void phonet_exit_net(struct net *net)
228 {
229         struct phonet_net *pnn = net_generic(net, phonet_net_id);
230         struct net_device *dev;
231
232         rtnl_lock();
233         for_each_netdev(net, dev)
234                 phonet_device_destroy(dev);
235         rtnl_unlock();
236         kfree(pnn);
237 }
238
239 static struct pernet_operations phonet_net_ops = {
240         .init = phonet_init_net,
241         .exit = phonet_exit_net,
242 };
243
244 /* Initialize Phonet devices list */
245 int __init phonet_device_init(void)
246 {
247         int err = register_pernet_gen_device(&phonet_net_id, &phonet_net_ops);
248         if (err)
249                 return err;
250
251         register_netdevice_notifier(&phonet_device_notifier);
252         err = phonet_netlink_register();
253         if (err)
254                 phonet_device_exit();
255         return err;
256 }
257
258 void phonet_device_exit(void)
259 {
260         rtnl_unregister_all(PF_PHONET);
261         unregister_netdevice_notifier(&phonet_device_notifier);
262         unregister_pernet_gen_device(phonet_net_id, &phonet_net_ops);
263 }