aboutsummaryrefslogtreecommitdiffstats
path: root/net/core/dev_mcast.c
blob: f8a3455f4493f7276fe614af6dbd7c26f4f04cb8 (plain) (blame)
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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/*
 *	Linux NET3:	Multicast List maintenance.
 *
 *	Authors:
 *		Tim Kordas <tjk@nostromo.eeap.cwru.edu>
 *		Richard Underwood <richard@wuzz.demon.co.uk>
 *
 *	Stir fried together from the IP multicast and CAP patches above
 *		Alan Cox <Alan.Cox@linux.org>
 *
 *	Fixes:
 *		Alan Cox	:	Update the device on a real delete
 *					rather than any time but...
 *		Alan Cox	:	IFF_ALLMULTI support.
 *		Alan Cox	: 	New format set_multicast_list() calls.
 *		Gleb Natapov    :       Remove dev_mc_lock.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/route.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/arp.h>


/*
 *	Device multicast list maintenance.
 *
 *	This is used both by IP and by the user level maintenance functions.
 *	Unlike BSD we maintain a usage count on a given multicast address so
 *	that a casual user application can add/delete multicasts used by
 *	protocols without doing damage to the protocols when it deletes the
 *	entries. It also helps IP as it tracks overlapping maps.
 *
 *	Device mc lists are changed by bh at least if IPv6 is enabled,
 *	so that it must be bh protected.
 *
 *	We block accesses to device mc filters with netif_tx_lock.
 */

/*
 *	Delete a device level multicast
 */

int dev_mc_delete(struct net_device *dev, void *addr, int alen, int glbl)
{
	int err;

	netif_tx_lock_bh(dev);
	err = __dev_addr_delete(&dev->mc_list, &dev->mc_count,
				addr, alen, glbl);
	if (!err) {
		/*
		 *	We have altered the list, so the card
		 *	loaded filter is now wrong. Fix it
		 */

		__dev_set_rx_mode(dev);
	}
	netif_tx_unlock_bh(dev);
	return err;
}

/*
 *	Add a device level multicast
 */

int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
{
	int err;

	netif_tx_lock_bh(dev);
	err = __dev_addr_add(&dev->mc_list, &dev->mc_count, addr, alen, glbl);
	if (!err)
		__dev_set_rx_mode(dev);
	netif_tx_unlock_bh(dev);
	return err;
}

/**
 *	dev_mc_sync	- Synchronize device's multicast list to another device
 *	@to: destination device
 *	@from: source device
 *
 * 	Add newly added addresses to the destination device and release
 * 	addresses that have no users left. The source device must be
 * 	locked by netif_tx_lock_bh.
 *
 *	This function is intended to be called from the dev->set_multicast_list
 *	or dev->set_rx_mode function of layered software devices.
 */
int dev_mc_sync(struct net_device *to, struct net_device *from)
{
	int err = 0;

	netif_tx_lock_bh(to);
	err = __dev_addr_sync(&to->mc_list, &to->mc_count,
			      &from->mc_list, &from->mc_count);
	if (!err)
		__dev_set_rx_mode(to);
	netif_tx_unlock_bh(to);

	return err;
}
EXPORT_SYMBOL(dev_mc_sync);


/**
 * 	dev_mc_unsync	- Remove synchronized addresses from the destination
 * 			  device
 *	@to: destination device
 *	@from: source device
 *
 * 	Remove all addresses that were added to the destination device by
 * 	dev_mc_sync(). This function is intended to be called from the
 * 	dev->stop function of layered software devices.
 */
void dev_mc_unsync(struct net_device *to, struct net_device *from)
{
	netif_tx_lock_bh(from);
	netif_tx_lock_bh(to);

	__dev_addr_unsync(&to->mc_list, &to->mc_count,
			  &from->mc_list, &from->mc_count);
	__dev_set_rx_mode(to);

	netif_tx_unlock_bh(to);
	netif_tx_unlock_bh(from);
}
EXPORT_SYMBOL(dev_mc_unsync);

#ifdef CONFIG_PROC_FS
static int dev_mc_seq_show(struct seq_file *seq, void *v)
{
	struct dev_addr_list *m;
	struct net_device *dev = v;

	if (v == SEQ_START_TOKEN)
		return 0;

	netif_tx_lock_bh(dev);
	for (m = dev->mc_list; m; m = m->next) {
		int i;

		seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
			   dev->name, m->dmi_users, m->dmi_gusers);

		for (i = 0; i < m->dmi_addrlen; i++)
			seq_printf(seq, "%02x", m->dmi_addr[i]);

		seq_putc(seq, '\n');
	}
	netif_tx_unlock_bh(dev);
	return 0;
}

static const struct seq_operations dev_mc_seq_ops = {
	.start = dev_seq_start,
	.next  = dev_seq_next,
	.stop  = dev_seq_stop,
	.show  = dev_mc_seq_show,
};

static int dev_mc_seq_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &dev_mc_seq_ops,
			    sizeof(struct seq_net_private));
}

static const struct file_operations dev_mc_seq_fops = {
	.owner	 = THIS_MODULE,
	.open    = dev_mc_seq_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release_net,
};

#endif

static int __net_init dev_mc_net_init(struct net *net)
{
	if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
		return -ENOMEM;
	return 0;
}

static void __net_exit dev_mc_net_exit(struct net *net)
{
	proc_net_remove(net, "dev_mcast");
}

static struct pernet_operations __net_initdata dev_mc_net_ops = {
	.init = dev_mc_net_init,
	.exit = dev_mc_net_exit,
};

void __init dev_mcast_init(void)
{
	register_pernet_subsys(&dev_mc_net_ops);
}

EXPORT_SYMBOL(dev_mc_add);
EXPORT_SYMBOL(dev_mc_delete);