/* *	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/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. */ /* *	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){	netif_tx_lock_bh(dev);	__dev_mc_upload(dev);	netif_tx_unlock_bh(dev);} /* *	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; 	netif_tx_lock_bh(dev); 	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); 			netif_tx_unlock_bh(dev);			return 0;		}	}	err = -ENOENT;done:	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 = 0;	struct dev_mc_list *dmi, *dmi1; 	dmi1 = kmalloc(sizeof(*dmi), GFP_ATOMIC); 	netif_tx_lock_bh(dev);	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) {		netif_tx_unlock_bh(dev);		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); 	netif_tx_unlock_bh(dev);	return 0; done:	netif_tx_unlock_bh(dev);	kfree(dmi1);	return err;} /* *	Discard multicast list when a device is downed */ void dev_mc_discard(struct net_device *dev){	netif_tx_lock_bh(dev); 	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; 	netif_tx_unlock_bh(dev);} #ifdef CONFIG_PROC_FSstatic void *dev_mc_seq_start(struct seq_file *seq, loff_t *pos){	struct net_device *dev;	loff_t off = 0; 	read_lock(&dev_base_lock);	for (dev = dev_base; dev; dev = dev->next) {		if (off++ == *pos)			return dev;	}	return NULL;} static void *dev_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos){	struct net_device *dev = v;	++*pos;	return dev->next;} static void dev_mc_seq_stop(struct seq_file *seq, void *v){	read_unlock(&dev_base_lock);}  static int dev_mc_seq_show(struct seq_file *seq, void *v){	struct dev_mc_list *m;	struct net_device *dev = v; 	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 struct seq_operations dev_mc_seq_ops = {	.start = dev_mc_seq_start,	.next  = dev_mc_seq_next,	.stop  = dev_mc_seq_stop,	.show  = dev_mc_seq_show,}; static int dev_mc_seq_open(struct inode *inode, struct file *file){	return seq_open(file, &dev_mc_seq_ops);} 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,}; #endif void __init dev_mcast_init(void){	proc_net_fops_create("dev_mcast", 0, &dev_mc_seq_fops);} EXPORT_SYMBOL(dev_mc_add);EXPORT_SYMBOL(dev_mc_delete);EXPORT_SYMBOL(dev_mc_upload);