path: root/net/core/dev_addr_lists.c

/*
 * net/core/dev_addr_lists.c - Functions for handling net device lists
 * Copyright (c) 2010 Jiri Pirko <jpirko@redhat.com>
 *
 * This file contains functions for working with unicast, multicast and device
 * addresses lists.
 *
 * 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/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/export.h>
#include <linux/list.h>

/*
 * General list handling functions
 */

static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
			       const unsigned char *addr, int addr_len,
			       unsigned char addr_type, bool global,
			       bool sync)
{
	struct netdev_hw_addr *ha;
	int alloc_size;

	alloc_size = sizeof(*ha);
	if (alloc_size < L1_CACHE_BYTES)
		alloc_size = L1_CACHE_BYTES;
	ha = kmalloc(alloc_size, GFP_ATOMIC);
	if (!ha)
		return -ENOMEM;
	memcpy(ha->addr, addr, addr_len);
	ha->type = addr_type;
	ha->refcount = 1;
	ha->global_use = global;
	ha->synced = sync;
	ha->sync_cnt = 0;
	list_add_tail_rcu(&ha->list, &list->list);
	list->count++;

	return 0;
}

static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
			    const unsigned char *addr, int addr_len,
			    unsigned char addr_type, bool global, bool sync)
{
	struct netdev_hw_addr *ha;

	if (addr_len > MAX_ADDR_LEN)
		return -EINVAL;

	list_for_each_entry(ha, &list->list, list) {
		if (!memcmp(ha->addr, addr, addr_len) &&
		    ha->type == addr_type) {
			if (global) {
				/* check if addr is already used as global */
				if (ha->global_use)
					return 0;
				else
					ha->global_use = true;
			}
			if (sync) {
				if (ha->synced)
					return -EEXIST;
				else
					ha->synced = true;
			}
			ha->refcount++;
			return 0;
		}
	}

	return __hw_addr_create_ex(list, addr, addr_len, addr_type, global,
				   sync);
}

static int __hw_addr_add(struct netdev_hw_addr_list *list,
			 const unsigned char *addr, int addr_len,
			 unsigned char addr_type)
{
	return __hw_addr_add_ex(list, addr, addr_len, addr_type, false, false);
}

static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
			       struct netdev_hw_addr *ha, bool global,
			       bool sync)
{
	if (global && !ha->global_use)
		return -ENOENT;

	if (sync && !ha->synced)
		return -ENOENT;

	if (global)
		ha->global_use = false;

	if (sync)
		ha->synced = false;

	if (--ha->refcount)
		return 0;
	list_del_rcu(&ha->list);
	kfree_rcu(ha, rcu_head);
	list->count--;
	return 0;
}

static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
			    const unsigned char *addr, int addr_len,
			    unsigned char addr_type, bool global, bool sync)
{
	struct netdev_hw_addr *ha;

	list_for_each_entry(ha, &list->list, list) {
		if (!memcmp(ha->addr, addr, addr_len) &&
		    (ha->type == addr_type || !addr_type))
			return __hw_addr_del_entry(list, ha, global, sync);
	}
	return -ENOENT;
}

static int __hw_addr_del(struct netdev_hw_addr_list *list,
			 const unsigned char *addr, int addr_len,
			 unsigned char addr_type)
{
	return __hw_addr_del_ex(list, addr, addr_len, addr_type, false, false);
}

static int __hw_addr_sync_one(struct netdev_hw_addr_list *to_list,
			       struct netdev_hw_addr *ha,
			       int addr_len)
{
	int err;

	err = __hw_addr_add_ex(to_list, ha->addr, addr_len, ha->type,
			       false, true);
	if (err && err != -EEXIST)
		return err;

	if (!err) {
		ha->sync_cnt++;
		ha->refcount++;
	}

	return 0;
}

static void __hw_addr_unsync_one(struct netdev_hw_addr_list *to_list,
				 struct netdev_hw_addr_list *from_list,
				 struct netdev_hw_addr *ha,
				 int addr_len)
{
	int err;

	err = __hw_addr_del_ex(to_list, ha->addr, addr_len, ha->type,
			       false, true);
	if (err)
		return;
	ha->sync_cnt--;
	/* address on from list is not marked synced */
	__hw_addr_del_entry(from_list, ha, false, false);
}

static int __hw_addr_sync_multiple(struct netdev_hw_addr_list