1 /*
2 * Linux NET3: Multicast List maintenance.
3 *
4 * Authors:
5 * Tim Kordas <tjk@nostromo.eeap.cwru.edu>
6 * Richard Underwood <richard@wuzz.demon.co.uk>
7 *
8 * Stir fried together from the IP multicast and CAP patches above
9 * Alan Cox <Alan.Cox@linux.org>
10 *
11 * Fixes:
12 * Alan Cox : Update the device on a real delete
13 * rather than any time but...
14 * Alan Cox : IFF_ALLMULTI support.
15 * Alan Cox : New format set_multicast_list() calls.
16 * Gleb Natapov : Remove dev_mc_lock.
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24 #include <linux/module.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/bitops.h>
28 #include <linux/types.h>
29 #include <linux/kernel.h>
30 #include <linux/string.h>
31 #include <linux/mm.h>
32 #include <linux/socket.h>
33 #include <linux/sockios.h>
34 #include <linux/in.h>
35 #include <linux/errno.h>
36 #include <linux/interrupt.h>
37 #include <linux/if_ether.h>
38 #include <linux/inet.h>
39 #include <linux/netdevice.h>
40 #include <linux/etherdevice.h>
41 #include <linux/proc_fs.h>
42 #include <linux/seq_file.h>
43 #include <linux/init.h>
44 #include <net/net_namespace.h>
45 #include <net/ip.h>
46 #include <net/route.h>
47 #include <linux/skbuff.h>
48 #include <net/sock.h>
49 #include <net/arp.h>
50
51
52 /*
53 * Device multicast list maintenance.
54 *
55 * This is used both by IP and by the user level maintenance functions.
56 * Unlike BSD we maintain a usage count on a given multicast address so
57 * that a casual user application can add/delete multicasts used by
58 * protocols without doing damage to the protocols when it deletes the
59 * entries. It also helps IP as it tracks overlapping maps.
60 *
61 * Device mc lists are changed by bh at least if IPv6 is enabled,
62 * so that it must be bh protected.
63 *
64 * We block accesses to device mc filters with netif_tx_lock.
65 */
66
67 /*
68 * Delete a device level multicast
69 */
70
71 int dev_mc_delete(struct net_device *dev, void *addr, int alen, int glbl)
72 {
73 int err;
74
75 netif_tx_lock_bh(dev);
76 err = __dev_addr_delete(&dev->mc_list, &dev->mc_count,
77 addr, alen, glbl);
78 if (!err) {
79 /*
80 * We have altered the list, so the card
81 * loaded filter is now wrong. Fix it
82 */
83
84 __dev_set_rx_mode(dev);
85 }
86 netif_tx_unlock_bh(dev);
87 return err;
88 }
89
90 /*
91 * Add a device level multicast
92 */
93
94 int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
95 {
96 int err;
97
98 netif_tx_lock_bh(dev);
99 err = __dev_addr_add(&dev->mc_list, &dev->mc_count, addr, alen, glbl);
100 if (!err)
101 __dev_set_rx_mode(dev);
102 netif_tx_unlock_bh(dev);
103 return err;
104 }
105
106 /**
107 * dev_mc_sync - Synchronize device's multicast list to another device
108 * @to: destination device
109 * @from: source device
110 *
111 * Add newly added addresses to the destination device and release
112 * addresses that have no users left. The source device must be
113 * locked by netif_tx_lock_bh.
114 *
115 * This function is intended to be called from the dev->set_multicast_list
116 * or dev->set_rx_mode function of layered software devices.
117 */
118 int dev_mc_sync(struct net_device *to, struct net_device *from)
119 {
120 int err = 0;
121
122 netif_tx_lock_bh(to);
123 err = __dev_addr_sync(&to->mc_list, &to->mc_count,
124 &from->mc_list, &from->mc_count);
125 if (!err)
126 __dev_set_rx_mode(to);
127 netif_tx_unlock_bh(to);
128
129 return err;
130 }
131 EXPORT_SYMBOL(dev_mc_sync);
132
133
134 /**
135 * dev_mc_unsync - Remove synchronized addresses from the destination
136 * device
137 * @to: destination device
138 * @from: source device
139 *
140 * Remove all addresses that were added to the destination device by
141 * dev_mc_sync(). This function is intended to be called from the
142 * dev->stop function of layered software devices.
143 */
144 void dev_mc_unsync(struct net_device *to, struct net_device *from)
145 {
146 netif_tx_lock_bh(from);
147 netif_tx_lock_bh(to);
148
149 __dev_addr_unsync(&to->mc_list, &to->mc_count,
150 &from->mc_list, &from->mc_count);
151 __dev_set_rx_mode(to);
152
153 netif_tx_unlock_bh(to);
154 netif_tx_unlock_bh(from);
155 }
156 EXPORT_SYMBOL(dev_mc_unsync);
157
158 #ifdef CONFIG_PROC_FS
159 static void *dev_mc_seq_start(struct seq_file *seq, loff_t *pos)
160 __acquires(dev_base_lock)
161 {
162 struct net *net = seq_file_net(seq);
163 struct net_device *dev;
164 loff_t off = 0;
165
166 read_lock(&dev_base_lock);
167 for_each_netdev(net, dev) {
168 if (off++ == *pos)
169 return dev;
170 }
171 return NULL;
172 }
173
174 static void *dev_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
175 {
176 ++*pos;
177 return next_net_device((struct net_device *)v);
178 }
179
180 static void dev_mc_seq_stop(struct seq_file *seq, void *v)
181 __releases(dev_base_lock)
182 {
183 read_unlock(&dev_base_lock);
184 }
185
186
187 static int dev_mc_seq_show(struct seq_file *seq, void *v)
188 {
189 struct dev_addr_list *m;
190 struct net_device *dev = v;
191
192 netif_tx_lock_bh(dev);
193 for (m = dev->mc_list; m; m = m->next) {
194 int i;
195
196 seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
197 dev->name, m->dmi_users, m->dmi_gusers);
198
199 for (i = 0; i < m->dmi_addrlen; i++)
200 seq_printf(seq, "%02x", m->dmi_addr[i]);
201
202 seq_putc(seq, '\n');
203 }
204 netif_tx_unlock_bh(dev);
205 return 0;
206 }
207
208 static const struct seq_operations dev_mc_seq_ops = {
209 .start = dev_mc_seq_start,
210 .next = dev_mc_seq_next,
211 .stop = dev_mc_seq_stop,
212 .show = dev_mc_seq_show,
213 };
214
215 static int dev_mc_seq_open(struct inode *inode, struct file *file)
216 {
217 return seq_open_net(inode, file, &dev_mc_seq_ops,
218 sizeof(struct seq_net_private));
219 }
220
221 static const struct file_operations dev_mc_seq_fops = {
222 .owner = THIS_MODULE,
223 .open = dev_mc_seq_open,
224 .read = seq_read,
225 .llseek = seq_lseek,
226 .release = seq_release_net,
227 };
228
229 #endif
230
231 static int __net_init dev_mc_net_init(struct net *net)
232 {
233 if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
234 return -ENOMEM;
235 return 0;
236 }
237
238 static void __net_exit dev_mc_net_exit(struct net *net)
239 {
240 proc_net_remove(net, "dev_mcast");
241 }
242
243 static struct pernet_operations __net_initdata dev_mc_net_ops = {
244 .init = dev_mc_net_init,
245 .exit = dev_mc_net_exit,
246 };
247
248 void __init dev_mcast_init(void)
249 {
250 register_pernet_subsys(&dev_mc_net_ops);
251 }
252
253 EXPORT_SYMBOL(dev_mc_add);
254 EXPORT_SYMBOL(dev_mc_delete);
255
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