blob: db098ff3cd6a7509b58cec0b45da50e6cf76673e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/config.h>
25#include <linux/module.h>
26#include <asm/uaccess.h>
27#include <asm/system.h>
28#include <linux/bitops.h>
29#include <linux/types.h>
30#include <linux/kernel.h>
31#include <linux/sched.h>
32#include <linux/string.h>
33#include <linux/mm.h>
34#include <linux/socket.h>
35#include <linux/sockios.h>
36#include <linux/in.h>
37#include <linux/errno.h>
38#include <linux/interrupt.h>
39#include <linux/if_ether.h>
40#include <linux/inet.h>
41#include <linux/netdevice.h>
42#include <linux/etherdevice.h>
43#include <linux/proc_fs.h>
44#include <linux/seq_file.h>
45#include <linux/init.h>
46#include <net/ip.h>
47#include <net/route.h>
48#include <linux/skbuff.h>
49#include <net/sock.h>
50#include <net/arp.h>
51
52
53/*
54 * Device multicast list maintenance.
55 *
56 * This is used both by IP and by the user level maintenance functions.
57 * Unlike BSD we maintain a usage count on a given multicast address so
58 * that a casual user application can add/delete multicasts used by
59 * protocols without doing damage to the protocols when it deletes the
60 * entries. It also helps IP as it tracks overlapping maps.
61 *
62 * Device mc lists are changed by bh at least if IPv6 is enabled,
63 * so that it must be bh protected.
64 *
65 * We block accesses to device mc filters with dev->xmit_lock.
66 */
67
68/*
69 * Update the multicast list into the physical NIC controller.
70 */
71
72static void __dev_mc_upload(struct net_device *dev)
73{
74 /* Don't do anything till we up the interface
75 * [dev_open will call this function so the list will
76 * stay sane]
77 */
78
79 if (!(dev->flags&IFF_UP))
80 return;
81
82 /*
83 * Devices with no set multicast or which have been
84 * detached don't get set.
85 */
86
87 if (dev->set_multicast_list == NULL ||
88 !netif_device_present(dev))
89 return;
90
91 dev->set_multicast_list(dev);
92}
93
94void dev_mc_upload(struct net_device *dev)
95{
96 spin_lock_bh(&dev->xmit_lock);
97 __dev_mc_upload(dev);
98 spin_unlock_bh(&dev->xmit_lock);
99}
100
101/*
102 * Delete a device level multicast
103 */
104
105int dev_mc_delete(struct net_device *dev, void *addr, int alen, int glbl)
106{
107 int err = 0;
108 struct dev_mc_list *dmi, **dmip;
109
110 spin_lock_bh(&dev->xmit_lock);
111
112 for (dmip = &dev->mc_list; (dmi = *dmip) != NULL; dmip = &dmi->next) {
113 /*
114 * Find the entry we want to delete. The device could
115 * have variable length entries so check these too.
116 */
117 if (memcmp(dmi->dmi_addr, addr, dmi->dmi_addrlen) == 0 &&
118 alen == dmi->dmi_addrlen) {
119 if (glbl) {
120 int old_glbl = dmi->dmi_gusers;
121 dmi->dmi_gusers = 0;
122 if (old_glbl == 0)
123 break;
124 }
125 if (--dmi->dmi_users)
126 goto done;
127
128 /*
129 * Last user. So delete the entry.
130 */
131 *dmip = dmi->next;
132 dev->mc_count--;
133
134 kfree(dmi);
135
136 /*
137 * We have altered the list, so the card
138 * loaded filter is now wrong. Fix it
139 */
140 __dev_mc_upload(dev);
141
142 spin_unlock_bh(&dev->xmit_lock);
143 return 0;
144 }
145 }
146 err = -ENOENT;
147done:
148 spin_unlock_bh(&dev->xmit_lock);
149 return err;
150}
151
152/*
153 * Add a device level multicast
154 */
155
156int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
157{
158 int err = 0;
159 struct dev_mc_list *dmi, *dmi1;
160
161 dmi1 = (struct dev_mc_list *)kmalloc(sizeof(*dmi), GFP_ATOMIC);
162
163 spin_lock_bh(&dev->xmit_lock);
164 for (dmi = dev->mc_list; dmi != NULL; dmi = dmi->next) {
165 if (memcmp(dmi->dmi_addr, addr, dmi->dmi_addrlen) == 0 &&
166 dmi->dmi_addrlen == alen) {
167 if (glbl) {
168 int old_glbl = dmi->dmi_gusers;
169 dmi->dmi_gusers = 1;
170 if (old_glbl)
171 goto done;
172 }
173 dmi->dmi_users++;
174 goto done;
175 }
176 }
177
178 if ((dmi = dmi1) == NULL) {
179 spin_unlock_bh(&dev->xmit_lock);
180 return -ENOMEM;
181 }
182 memcpy(dmi->dmi_addr, addr, alen);
183 dmi->dmi_addrlen = alen;
184 dmi->next = dev->mc_list;
185 dmi->dmi_users = 1;
186 dmi->dmi_gusers = glbl ? 1 : 0;
187 dev->mc_list = dmi;
188 dev->mc_count++;
189
190 __dev_mc_upload(dev);
191
192 spin_unlock_bh(&dev->xmit_lock);
193 return 0;
194
195done:
196 spin_unlock_bh(&dev->xmit_lock);
197 if (dmi1)
198 kfree(dmi1);
199 return err;
200}
201
202/*
203 * Discard multicast list when a device is downed
204 */
205
206void dev_mc_discard(struct net_device *dev)
207{
208 spin_lock_bh(&dev->xmit_lock);
209
210 while (dev->mc_list != NULL) {
211 struct dev_mc_list *tmp = dev->mc_list;
212 dev->mc_list = tmp->next;
213 if (tmp->dmi_users > tmp->dmi_gusers)
214 printk("dev_mc_discard: multicast leakage! dmi_users=%d\n", tmp->dmi_users);
215 kfree(tmp);
216 }
217 dev->mc_count = 0;
218
219 spin_unlock_bh(&dev->xmit_lock);
220}
221
222#ifdef CONFIG_PROC_FS
223static void *dev_mc_seq_start(struct seq_file *seq, loff_t *pos)
224{
225 struct net_device *dev;
226 loff_t off = 0;
227
228 read_lock(&dev_base_lock);
229 for (dev = dev_base; dev; dev = dev->next) {
230 if (off++ == *pos)
231 return dev;
232 }
233 return NULL;
234}
235
236static void *dev_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
237{
238 struct net_device *dev = v;
239 ++*pos;
240 return dev->next;
241}
242
243static void dev_mc_seq_stop(struct seq_file *seq, void *v)
244{
245 read_unlock(&dev_base_lock);
246}
247
248
249static int dev_mc_seq_show(struct seq_file *seq, void *v)
250{
251 struct dev_mc_list *m;
252 struct net_device *dev = v;
253
254 spin_lock_bh(&dev->xmit_lock);
255 for (m = dev->mc_list; m; m = m->next) {
256 int i;
257
258 seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
259 dev->name, m->dmi_users, m->dmi_gusers);
260
261 for (i = 0; i < m->dmi_addrlen; i++)
262 seq_printf(seq, "%02x", m->dmi_addr[i]);
263
264 seq_putc(seq, '\n');
265 }
266 spin_unlock_bh(&dev->xmit_lock);
267 return 0;
268}
269
270static struct seq_operations dev_mc_seq_ops = {
271 .start = dev_mc_seq_start,
272 .next = dev_mc_seq_next,
273 .stop = dev_mc_seq_stop,
274 .show = dev_mc_seq_show,
275};
276
277static int dev_mc_seq_open(struct inode *inode, struct file *file)
278{
279 return seq_open(file, &dev_mc_seq_ops);
280}
281
282static struct file_operations dev_mc_seq_fops = {
283 .owner = THIS_MODULE,
284 .open = dev_mc_seq_open,
285 .read = seq_read,
286 .llseek = seq_lseek,
287 .release = seq_release,
288};
289
290#endif
291
292void __init dev_mcast_init(void)
293{
294 proc_net_fops_create("dev_mcast", 0, &dev_mc_seq_fops);
295}
296
297EXPORT_SYMBOL(dev_mc_add);
298EXPORT_SYMBOL(dev_mc_delete);
299EXPORT_SYMBOL(dev_mc_upload);