dev_addr_lists.c

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/*
 * net/core/dev_addr_lists.c - Functions for handling net device lists
 * Copyright (c) 2010 Jiri Pirko <[email protected]>
 *
 * 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>
#include <linux/proc_fs.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)
{
    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 = false;
    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)
{
    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;
            }
            ha->refcount++;
            return 0;
        }
    }

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

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);
}

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)
{
    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)) {
            if (global) {
                if (!ha->global_use)
                    break;
                else
                    ha->global_use = false;
            }
            if (--ha->refcount)
                return 0;
            list_del_rcu(&ha->list);
            kfree_rcu(ha, rcu_head);
            list->count--;
            return 0;
        }
    }
    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);
}

int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
               struct netdev_hw_addr_list *from_list,
               int addr_len, unsigned char addr_type)
{
    int err;
    struct netdev_hw_addr *ha, *ha2;
    unsigned char type;

    list_for_each_entry(ha, &from_list->list, list) {
        type = addr_type ? addr_type : ha->type;
        err = __hw_addr_add(to_list, ha->addr, addr_len, type);
        if (err)
            goto unroll;
    }
    return 0;

unroll:
    list_for_each_entry(ha2, &from_list->list, list) {
        if (ha2 == ha)
            break;
        type = addr_type ? addr_type : ha2->type;
        __hw_addr_del(to_list, ha2->addr, addr_len, type);
    }
    return err;
}
EXPORT_SYMBOL(__hw_addr_add_multiple);

void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
                struct netdev_hw_addr_list *from_list,
                int addr_len, unsigned char addr_type)
{
    struct netdev_hw_addr *ha;
    unsigned char type;

    list_for_each_entry(ha, &from_list->list, list) {
        type = addr_type ? addr_type : ha->type;
        __hw_addr_del(to_list, ha->addr, addr_len, type);
    }
}
EXPORT_SYMBOL(__hw_addr_del_multiple);

int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
           struct netdev_hw_addr_list *from_list,
           int addr_len)
{
    int err = 0;
    struct netdev_hw_addr *ha, *tmp;

    list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
        if (!ha->synced) {
            err = __hw_addr_add(to_list, ha->addr,
                        addr_len, ha->type);
            if (err)
                break;
            ha->synced = true;
            ha->refcount++;
        } else if (ha->refcount == 1) {
            __hw_addr_del(to_list, ha->addr, addr_len, ha->type);
            __hw_addr_del(from_list, ha->addr, addr_len, ha->type);
        }
    }
    return err;
}
EXPORT_SYMBOL(__hw_addr_sync);

void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
              struct netdev_hw_addr_list *from_list,
              int addr_len)
{
    struct netdev_hw_addr *ha, *tmp;

    list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
        if (ha->synced) {
            __hw_addr_del(to_list, ha->addr,
                      addr_len, ha->type);
            ha->synced = false;
            __hw_addr_del(from_list, ha->addr,
                      addr_len, ha->type);
        }
    }
}
EXPORT_SYMBOL(__hw_addr_unsync);

void __hw_addr_flush(struct netdev_hw_addr_list *list)
{
    struct netdev_hw_addr *ha, *tmp;

    list_for_each_entry_safe(ha, tmp, &list->list, list) {
        list_del_rcu(&ha->list);
        kfree_rcu(ha, rcu_head);
    }
    list->count = 0;
}
EXPORT_SYMBOL(__hw_addr_flush);

void __hw_addr_init(struct netdev_hw_addr_list *list)
{
    INIT_LIST_HEAD(&list->list);
    list->count = 0;
}
EXPORT_SYMBOL(__hw_addr_init);

/*
 * Device addresses handling functions
 */

void dev_addr_flush(struct net_device *dev)
{
    /* rtnl_mutex must be held here */

    __hw_addr_flush(&dev->dev_addrs);
    dev->dev_addr = NULL;
}
EXPORT_SYMBOL(dev_addr_flush);

int dev_addr_init(struct net_device *dev)
{
    unsigned char addr[MAX_ADDR_LEN];
    struct netdev_hw_addr *ha;
    int err;

    /* rtnl_mutex must be held here */

    __hw_addr_init(&dev->dev_addrs);
    memset(addr, 0, sizeof(addr));
    err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
                NETDEV_HW_ADDR_T_LAN);
    if (!err) {
        /*
         * Get the first (previously created) address from the list
         * and set dev_addr pointer to this location.
         */
        ha = list_first_entry(&dev->dev_addrs.list,
                      struct netdev_hw_addr, list);
        dev->dev_addr = ha->addr;
    }
    return err;
}
EXPORT_SYMBOL(dev_addr_init);

int dev_addr_add(struct net_device *dev, const unsigned char *addr,
         unsigned char addr_type)
{
    int err;

    ASSERT_RTNL();

    err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
    if (!err)
        call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
    return err;
}
EXPORT_SYMBOL(dev_addr_add);

int dev_addr_del(struct net_device *dev, const unsigned char *addr,
         unsigned char addr_type)
{
    int err;
    struct netdev_hw_addr *ha;

    ASSERT_RTNL();

    /*
     * We can not remove the first address from the list because
     * dev->dev_addr points to that.
     */
    ha = list_first_entry(&dev->dev_addrs.list,
                  struct netdev_hw_addr, list);
    if (!memcmp(ha->addr, addr, dev->addr_len) &&
        ha->type == addr_type && ha->refcount == 1)
        return -ENOENT;

    err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
                addr_type);
    if (!err)
        call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
    return err;
}
EXPORT_SYMBOL(dev_addr_del);

int dev_addr_add_multiple(struct net_device *to_dev,
              struct net_device *from_dev,
              unsigned char addr_type)
{
    int err;

    ASSERT_RTNL();

    if (from_dev->addr_len != to_dev->addr_len)
        return -EINVAL;
    err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
                     to_dev->addr_len, addr_type);
    if (!err)
        call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
    return err;
}
EXPORT_SYMBOL(dev_addr_add_multiple);

int dev_addr_del_multiple(struct net_device *to_dev,
              struct net_device *from_dev,
              unsigned char addr_type)
{
    ASSERT_RTNL();

    if (from_dev->addr_len != to_dev->addr_len)
        return -EINVAL;
    __hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
                   to_dev->addr_len, addr_type);
    call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
    return 0;
}
EXPORT_SYMBOL(dev_addr_del_multiple);

/*
 * Unicast list handling functions
 */

int dev_uc_add_excl(struct net_device *dev, const unsigned char *addr)
{
    struct netdev_hw_addr *ha;
    int err;

    netif_addr_lock_bh(dev);
    list_for_each_entry(ha, &dev->uc.list, list) {
        if (!memcmp(ha->addr, addr, dev->addr_len) &&
            ha->type == NETDEV_HW_ADDR_T_UNICAST) {
            err = -EEXIST;
            goto out;
        }
    }
    err = __hw_addr_create_ex(&dev->uc, addr, dev->addr_len,
                  NETDEV_HW_ADDR_T_UNICAST, true);
    if (!err)
        __dev_set_rx_mode(dev);
out:
    netif_addr_unlock_bh(dev);
    return err;
}
EXPORT_SYMBOL(dev_uc_add_excl);

int dev_uc_add(struct net_device *dev, const unsigned char *addr)
{
    int err;

    netif_addr_lock_bh(dev);
    err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
                NETDEV_HW_ADDR_T_UNICAST);
    if (!err)
        __dev_set_rx_mode(dev);
    netif_addr_unlock_bh(dev);
    return err;
}
EXPORT_SYMBOL(dev_uc_add);

int dev_uc_del(struct net_device *dev, const unsigned char *addr)
{
    int err;

    netif_addr_lock_bh(dev);
    err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
                NETDEV_HW_ADDR_T_UNICAST);
    if (!err)
        __dev_set_rx_mode(dev);
    netif_addr_unlock_bh(dev);
    return err;
}
EXPORT_SYMBOL(dev_uc_del);

int dev_uc_sync(struct net_device *to, struct net_device *from)
{
    int err = 0;

    if (to->addr_len != from->addr_len)
        return -EINVAL;

    netif_addr_lock_nested(to);
    err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
    if (!err)
        __dev_set_rx_mode(to);
    netif_addr_unlock(to);
    return err;
}
EXPORT_SYMBOL(dev_uc_sync);

void dev_uc_unsync(struct net_device *to, struct net_device *from)
{
    if (to->addr_len != from->addr_len)
        return;

    netif_addr_lock_bh(from);
    netif_addr_lock_nested(to);
    __hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
    __dev_set_rx_mode(to);
    netif_addr_unlock(to);
    netif_addr_unlock_bh(from);
}
EXPORT_SYMBOL(dev_uc_unsync);

void dev_uc_flush(struct net_device *dev)
{
    netif_addr_lock_bh(dev);
    __hw_addr_flush(&dev->uc);
    netif_addr_unlock_bh(dev);
}
EXPORT_SYMBOL(dev_uc_flush);

void dev_uc_init(struct net_device *dev)
{
    __hw_addr_init(&dev->uc);
}
EXPORT_SYMBOL(dev_uc_init);

/*
 * Multicast list handling functions
 */

int dev_mc_add_excl(struct net_device *dev, const unsigned char *addr)
{
    struct netdev_hw_addr *ha;
    int err;

    netif_addr_lock_bh(dev);
    list_for_each_entry(ha, &dev->mc.list, list) {
        if (!memcmp(ha->addr, addr, dev->addr_len) &&
            ha->type == NETDEV_HW_ADDR_T_MULTICAST) {
            err = -EEXIST;
            goto out;
        }
    }
    err = __hw_addr_create_ex(&dev->mc, addr, dev->addr_len,
                  NETDEV_HW_ADDR_T_MULTICAST, true);
    if (!err)
        __dev_set_rx_mode(dev);
out:
    netif_addr_unlock_bh(dev);
    return err;
}
EXPORT_SYMBOL(dev_mc_add_excl);

static int __dev_mc_add(struct net_device *dev, const unsigned char *addr,
            bool global)
{
    int err;

    netif_addr_lock_bh(dev);
    err = __hw_addr_add_ex(&dev->mc, addr, dev->addr_len,
                   NETDEV_HW_ADDR_T_MULTICAST, global);
    if (!err)
        __dev_set_rx_mode(dev);
    netif_addr_unlock_bh(dev);
    return err;
}
int dev_mc_add(struct net_device *dev, const unsigned char *addr)
{
    return __dev_mc_add(dev, addr, false);
}
EXPORT_SYMBOL(dev_mc_add);

int dev_mc_add_global(struct net_device *dev, const unsigned char *addr)
{
    return __dev_mc_add(dev, addr, true);
}
EXPORT_SYMBOL(dev_mc_add_global);

static int __dev_mc_del(struct net_device *dev, const unsigned char *addr,
            bool global)
{
    int err;

    netif_addr_lock_bh(dev);
    err = __hw_addr_del_ex(&dev->mc, addr, dev->addr_len,
                   NETDEV_HW_ADDR_T_MULTICAST, global);
    if (!err)
        __dev_set_rx_mode(dev);
    netif_addr_unlock_bh(dev);
    return err;
}

int dev_mc_del(struct net_device *dev, const unsigned char *addr)
{
    return __dev_mc_del(dev, addr, false);
}
EXPORT_SYMBOL(dev_mc_del);

int dev_mc_del_global(struct net_device *dev, const unsigned char *addr)
{
    return __dev_mc_del(dev, addr, true);
}
EXPORT_SYMBOL(dev_mc_del_global);

int dev_mc_sync(struct net_device *to, struct net_device *from)
{
    int err = 0;

    if (to->addr_len != from->addr_len)
        return -EINVAL;

    netif_addr_lock_nested(to);
    err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
    if (!err)
        __dev_set_rx_mode(to);
    netif_addr_unlock(to);
    return err;
}
EXPORT_SYMBOL(dev_mc_sync);

void dev_mc_unsync(struct net_device *to, struct net_device *from)
{
    if (to->addr_len != from->addr_len)
        return;

    netif_addr_lock_bh(from);
    netif_addr_lock_nested(to);
    __hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
    __dev_set_rx_mode(to);
    netif_addr_unlock(to);
    netif_addr_unlock_bh(from);
}
EXPORT_SYMBOL(dev_mc_unsync);

void dev_mc_flush(struct net_device *dev)
{
    netif_addr_lock_bh(dev);
    __hw_addr_flush(&dev->mc);
    netif_addr_unlock_bh(dev);
}
EXPORT_SYMBOL(dev_mc_flush);

void dev_mc_init(struct net_device *dev)
{
    __hw_addr_init(&dev->mc);
}
EXPORT_SYMBOL(dev_mc_init);

#ifdef CONFIG_PROC_FS
#include <linux/seq_file.h>

static int dev_mc_seq_show(struct seq_file *seq, void *v)
{
    struct netdev_hw_addr *ha;
    struct net_device *dev = v;

    if (v == SEQ_START_TOKEN)
        return 0;

    netif_addr_lock_bh(dev);
    netdev_for_each_mc_addr(ha, dev) {
        int i;

        seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
               dev->name, ha->refcount, ha->global_use);

        for (i = 0; i < dev->addr_len; i++)
            seq_printf(seq, "%02x", ha->addr[i]);

        seq_putc(seq, '\n');
    }
    netif_addr_unlock_bh(dev);
    return 0;
}

static const struct seq_operations dev_mc_seq_ops = {
    .start = dev_seq_start,
    .next  = dev_seq_next,
    .stop  = dev_seq_stop,
    .show  = dev_mc_seq_show,
};

static int dev_mc_seq_open(struct inode *inode, struct file *file)
{
    return seq_open_net(inode, file, &dev_mc_seq_ops,
                sizeof(struct seq_net_private));
}

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_net,
};

#endif

static int __net_init dev_mc_net_init(struct net *net)
{
    if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
        return -ENOMEM;
    return 0;
}

static void __net_exit dev_mc_net_exit(struct net *net)
{
    proc_net_remove(net, "dev_mcast");
}

static struct pernet_operations __net_initdata dev_mc_net_ops = {
    .init = dev_mc_net_init,
    .exit = dev_mc_net_exit,
};

void __init dev_mcast_init(void)
{
    register_pernet_subsys(&dev_mc_net_ops);
}