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/*
* 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/config.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.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/init.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 dev->xmit_lock.
*/
/*
* Update the multicast list into the physical NIC controller.
*/
static void __dev_mc_upload(struct net_device *dev)
{
/* Don't do anything till we up the interface
* [dev_open will call this function so the list will
* stay sane]
*/
if (!(dev->flags&IFF_UP))
return;
/*
* Devices with no set multicast or which have been
* detached don't get set.
*/
if (dev->set_multicast_list == NULL ||
!netif_device_present(dev))
return;
dev->set_multicast_list(dev);
}
void dev_mc_upload(struct net_device *dev)
{
spin_lock_bh(&dev->xmit_lock);
__dev_mc_upload(dev);
spin_unlock_bh(&dev->xmit_lock);
}
/*
* Delete a device level multicast
*/
int dev_mc_delete(struct net_device *dev, void *addr, int alen, int glbl)
{
int err = 0;
struct dev_mc_list *dmi, **dmip;
spin_lock_bh(&dev->xmit_lock);
for (dmip = &dev->mc_list; (dmi = *dmip) != NULL; dmip = &dmi->next) {
/*
* Find the entry we want to delete. The device could
* have variable length entries so check these too.
*/
if (memcmp(dmi->dmi_addr, addr, dmi->dmi_addrlen) == 0 &&
alen == dmi->dmi_addrlen) {
if (glbl) {
int old_glbl = dmi->dmi_gusers;
dmi->dmi_gusers = 0;
if (old_glbl == 0)
break;
}
if (--dmi->dmi_users)
goto done;
/*
* Last user. So delete the entry.
*/
*dmip = dmi->next;
dev->mc_count--;
kfree(dmi);
/*
* We have altered the list, so the card
* loaded filter is now wrong. Fix it
*/
__dev_mc_upload(dev);
spin_unlock_bh(&dev->xmit_lock);
return 0;
}
}
err = -ENOENT;
done:
spin_unlock_bh(&dev->xmit_lock);
return err;
}
/*
* Add a device level multicast
*/
int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
{
int err = 0;
struct dev_mc_list *dmi, *dmi1;
dmi1 = (struct dev_mc_list *)kmalloc(sizeof(*dmi), GFP_ATOMIC);
spin_lock_bh(&dev->xmit_lock);
for (dmi = dev->mc_list; dmi != NULL; dmi = dmi->next) {
if (memcmp(dmi->dmi_addr, addr, dmi->dmi_addrlen) == 0 &&
dmi->dmi_addrlen == alen) {
if (glbl) {
int old_glbl = dmi->dmi_gusers;
dmi->dmi_gusers = 1;
if (old_glbl)
goto done;
}
dmi->dmi_users++;
goto done;
}
}
if ((dmi = dmi1) == NULL) {
spin_unlock_bh(&dev->xmit_lock);
return -ENOMEM;
}
memcpy(dmi->dmi_addr, addr, alen);
dmi->dmi_addrlen = alen;
dmi->next = dev->mc_list;
dmi->dmi_users = 1;
dmi->dmi_gusers = glbl ? 1 : 0;
dev->mc_list = dmi;
dev->mc_count++;
__dev_mc_upload(dev);
spin_unlock_bh(&dev->xmit_lock);
return 0;
done:
spin_unlock_bh(&dev->xmit_lock);
if (dmi1)
kfree(dmi1);
return err;
}
/*
* Discard multicast list when a device is downed
*/
void dev_mc_discard(struct net_device *dev)
{
spin_lock_bh(&dev->xmit_lock);
while (dev->mc_list != NULL) {
struct dev_mc_list *tmp = dev->mc_list;
dev->mc_list = tmp->next;
if (tmp->dmi_users > tmp->dmi_gusers)
printk("dev_mc_discard: multicast leakage! dmi_users=%d\n", tmp->dmi_users);
kfree(tmp);
}
dev->mc_count = 0;
spin_unlock_bh(&dev->xmit_lock);
}
#ifdef CONFIG_PROC_FS
static int dev_mc_read_proc(char *buffer, char **start, off_t offset,
int length, int *eof, void *data)
{
off_t pos = 0, begin = 0;
struct dev_mc_list *m;
int len = 0;
struct net_device *dev;
read_lock(&dev_base_lock);
for (dev = dev_base; dev; dev = dev->next) {
spin_lock_bh(&dev->xmit_lock);
for (m = dev->mc_list; m; m = m->next) {
int i;
len += sprintf(buffer+len,"%-4d %-15s %-5d %-5d ", dev->ifindex,
dev->name, m->dmi_users, m->dmi_gusers);
for (i = 0; i < m->dmi_addrlen; i++)
len += sprintf(buffer+len, "%02x", m->dmi_addr[i]);
len += sprintf(buffer+len, "\n");
pos = begin + len;
if (pos < offset) {
len = 0;
begin = pos;
}
if (pos > offset + length) {
spin_unlock_bh(&dev->xmit_lock);
goto done;
}
}
spin_unlock_bh(&dev->xmit_lock);
}
*eof = 1;
done:
read_unlock(&dev_base_lock);
*start = buffer + (offset - begin);
len -= (offset - begin);
if (len > length)
len = length;
if (len < 0)
len = 0;
return len;
}
#endif
void __init dev_mcast_init(void)
{
#ifdef CONFIG_PROC_FS
create_proc_read_entry("net/dev_mcast", 0, 0, dev_mc_read_proc, NULL);
#endif
}
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