aboutsummaryrefslogtreecommitdiff
path: root/net/phonet/pn_dev.c
blob: 3e24c0522ee3de41d5a0847f0c5b480193a8e5db (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*
 * File: pn_dev.c
 *
 * Phonet network device
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/phonet.h>
#include <net/sock.h>
#include <net/phonet/pn_dev.h>

/* when accessing, remember to lock with spin_lock(&pndevs.lock); */
struct phonet_device_list pndevs = {
	.list = LIST_HEAD_INIT(pndevs.list),
	.lock = __SPIN_LOCK_UNLOCKED(pndevs.lock),
};

/* Allocate new Phonet device. */
static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
{
	struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
	if (pnd == NULL)
		return NULL;
	pnd->netdev = dev;
	bitmap_zero(pnd->addrs, 64);

	list_add(&pnd->list, &pndevs.list);
	return pnd;
}

static struct phonet_device *__phonet_get(struct net_device *dev)
{
	struct phonet_device *pnd;

	list_for_each_entry(pnd, &pndevs.list, list) {
		if (pnd->netdev == dev)
			return pnd;
	}
	return NULL;
}

static void __phonet_device_free(struct phonet_device *pnd)
{
	list_del(&pnd->list);
	kfree(pnd);
}

struct net_device *phonet_device_get(struct net *net)
{
	struct phonet_device *pnd;
	struct net_device *dev;

	spin_lock_bh(&pndevs.lock);
	list_for_each_entry(pnd, &pndevs.list, list) {
		dev = pnd->netdev;
		BUG_ON(!dev);

		if (net_eq(dev_net(dev), net) &&
			(dev->reg_state == NETREG_REGISTERED) &&
			((pnd->netdev->flags & IFF_UP)) == IFF_UP)
			break;
		dev = NULL;
	}
	if (dev)
		dev_hold(dev);
	spin_unlock_bh(&pndevs.lock);
	return dev;
}

int phonet_address_add(struct net_device *dev, u8 addr)
{
	struct phonet_device *pnd;
	int err = 0;

	spin_lock_bh(&pndevs.lock);
	/* Find or create Phonet-specific device data */
	pnd = __phonet_get(dev);
	if (pnd == NULL)
		pnd = __phonet_device_alloc(dev);
	if (unlikely(pnd == NULL))
		err = -ENOMEM;
	else if (test_and_set_bit(addr >> 2, pnd->addrs))
		err = -EEXIST;
	spin_unlock_bh(&pndevs.lock);
	return err;
}

int phonet_address_del(struct net_device *dev, u8 addr)
{
	struct phonet_device *pnd;
	int err = 0;

	spin_lock_bh(&pndevs.lock);
	pnd = __phonet_get(dev);
	if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
		err = -EADDRNOTAVAIL;
	else if (bitmap_empty(pnd->addrs, 64))
		__phonet_device_free(pnd);
	spin_unlock_bh(&pndevs.lock);
	return err;
}

/* Gets a source address toward a destination, through a interface. */
u8 phonet_address_get(struct net_device *dev, u8 addr)
{
	struct phonet_device *pnd;

	spin_lock_bh(&pndevs.lock);
	pnd = __phonet_get(dev);
	if (pnd) {
		BUG_ON(bitmap_empty(pnd->addrs, 64));

		/* Use same source address as destination, if possible */
		if (!test_bit(addr >> 2, pnd->addrs))
			addr = find_first_bit(pnd->addrs, 64) << 2;
	} else
		addr = PN_NO_ADDR;
	spin_unlock_bh(&pndevs.lock);
	return addr;
}

int phonet_address_lookup(struct net *net, u8 addr)
{
	struct phonet_device *pnd;

	spin_lock_bh(&pndevs.lock);
	list_for_each_entry(pnd, &pndevs.list, list) {
		if (!net_eq(dev_net(pnd->netdev), net))
			continue;
		/* Don't allow unregistering devices! */
		if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
				((pnd->netdev->flags & IFF_UP)) != IFF_UP)
			continue;

		if (test_bit(addr >> 2, pnd->addrs)) {
			spin_unlock_bh(&pndevs.lock);
			return 0;
		}
	}
	spin_unlock_bh(&pndevs.lock);
	return -EADDRNOTAVAIL;
}

/* notify Phonet of device events */
static int phonet_device_notify(struct notifier_block *me, unsigned long what,
				void *arg)
{
	struct net_device *dev = arg;

	if (what == NETDEV_UNREGISTER) {
		struct phonet_device *pnd;

		/* Destroy phonet-specific device data */
		spin_lock_bh(&pndevs.lock);
		pnd = __phonet_get(dev);
		if (pnd)
			__phonet_device_free(pnd);
		spin_unlock_bh(&pndevs.lock);
	}
	return 0;

}

static struct notifier_block phonet_device_notifier = {
	.notifier_call = phonet_device_notify,
	.priority = 0,
};

/* Initialize Phonet devices list */
int __init phonet_device_init(void)
{
	int err;

	register_netdevice_notifier(&phonet_device_notifier);
	err = phonet_netlink_register();
	if (err)
		phonet_device_exit();
	return err;
}

void phonet_device_exit(void)
{
	struct phonet_device *pnd, *n;

	rtnl_unregister_all(PF_PHONET);
	unregister_netdevice_notifier(&phonet_device_notifier);

	list_for_each_entry_safe(pnd, n, &pndevs.list, list)
		__phonet_device_free(pnd);
}