path: root/net/core/dev_addr_lists.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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.
 */

#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/export.h>
#include <linux/list.h>

#include "dev.h"

/*
 * General list handling functions
 */

static int __hw_addr_insert(struct netdev_hw_addr_list *list,
			    struct netdev_hw_addr *new, int addr_len)
{
	struct rb_node **ins_point = &list->tree.rb_node, *parent = NULL;
	struct netdev_hw_addr *ha;

	while (*ins_point) {
		int diff;

		ha = rb_entry(*ins_point, struct netdev_hw_addr, node);
		diff = memcmp(new->addr, ha->addr, addr_len);
		if (diff == 0)
			diff = memcmp(&new->type, &ha->type, sizeof(new->type));

		parent = *ins_point;
		if (diff < 0)
			ins_point = &parent->rb_left;
		else if (diff > 0)
			ins_point = &parent->rb_right;
		else
			return -EEXIST;
	}

	rb_link_node_rcu(&new->node, parent, ins_point);
	rb_insert_color(&new->node, &list->tree);

	return 0;
}

static struct netdev_hw_addr*
__hw_addr_create(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 NULL;
	memcpy(ha->addr, addr, addr_len);
	ha->type = addr_type;
	ha->refcount = 1;
	ha->global_use = global;
	ha->synced = sync ? 1 : 0;
	ha->sync_cnt = 0;

	return ha;
}

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,
			    int sync_count, bool exclusive)
{
	struct rb_node **ins_point = &list->tree.rb_node, *parent = NULL;
	struct netdev_hw_addr *ha;

	if (addr_len > MAX_ADDR_LEN)
		return -EINVAL;

	while (*ins_point) {
		int diff;

		ha = rb_entry(*ins_point, struct netdev_hw_addr, node);
		diff = memcmp(addr, ha->addr, addr_len);
		if (diff == 0)
			diff = memcmp(&addr_type, &ha->type, sizeof(addr_type));

		parent = *ins_point;
		if (diff < 0) {
			ins_point = &parent->rb_left;
		} else if (diff > 0) {
			ins_point = &parent->rb_right;
		} else {
			if (exclusive)
				return -EEXIST;
			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 && sync_count)
					return -EEXIST;
				else
					ha->synced++;
			}
			ha->refcount++;
			return 0;
		}
	}

	ha = __hw_addr_create(addr, addr_len, addr_type, global, sync);
	if (!ha)
		return -ENOMEM;

	rb_link_node(&ha->node, parent, ins_point);
	rb_insert_color(&ha->node, &list->tree);

	list_add_tail_rcu(&ha->list, &list->list);
	list->count++;

	return 0;
}

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,
				0, 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--;

	if (--ha->refcount)
		return 0;

	rb_erase(&ha->node, &list->tree);

	list_del_rcu(&ha->list);
	kfree_rcu(