etherdevice.h

Go to the documentation of this file.

/*
 * INET     An implementation of the TCP/IP protocol suite for the LINUX
 *      operating system.  NET  is implemented using the  BSD Socket
 *      interface as the means of communication with the user level.
 *
 *      Definitions for the Ethernet handlers.
 *
 * Version: @(#)eth.h   1.0.4   05/13/93
 *
 * Authors: Ross Biro
 *      Fred N. van Kempen, <[email protected]>
 *
 *      Relocated to include/linux where it belongs by Alan Cox 
 *                          <[email protected]>
 *
 *      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.
 *
 */
#ifndef _LINUX_ETHERDEVICE_H
#define _LINUX_ETHERDEVICE_H

#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/random.h>
#include <asm/unaligned.h>

#ifdef __KERNEL__
extern __be16       eth_type_trans(struct sk_buff *skb, struct net_device *dev);
extern const struct header_ops eth_header_ops;

extern int eth_header(struct sk_buff *skb, struct net_device *dev,
              unsigned short type,
              const void *daddr, const void *saddr, unsigned len);
extern int eth_rebuild_header(struct sk_buff *skb);
extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
extern void eth_header_cache_update(struct hh_cache *hh,
                    const struct net_device *dev,
                    const unsigned char *haddr);
extern int eth_mac_addr(struct net_device *dev, void *p);
extern int eth_change_mtu(struct net_device *dev, int new_mtu);
extern int eth_validate_addr(struct net_device *dev);



extern struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
                        unsigned int rxqs);
#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
#define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)

static inline bool is_zero_ether_addr(const u8 *addr)
{
    return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
}

static inline bool is_multicast_ether_addr(const u8 *addr)
{
    return 0x01 & addr[0];
}

static inline bool is_local_ether_addr(const u8 *addr)
{
    return 0x02 & addr[0];
}

static inline bool is_broadcast_ether_addr(const u8 *addr)
{
    return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
}

static inline bool is_unicast_ether_addr(const u8 *addr)
{
    return !is_multicast_ether_addr(addr);
}

static inline bool is_valid_ether_addr(const u8 *addr)
{
    /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
     * explicitly check for it here. */
    return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
}

static inline void eth_random_addr(u8 *addr)
{
    get_random_bytes(addr, ETH_ALEN);
    addr[0] &= 0xfe;    /* clear multicast bit */
    addr[0] |= 0x02;    /* set local assignment bit (IEEE802) */
}

#define random_ether_addr(addr) eth_random_addr(addr)

static inline void eth_broadcast_addr(u8 *addr)
{
    memset(addr, 0xff, ETH_ALEN);
}

static inline void eth_zero_addr(u8 *addr)
{
    memset(addr, 0x00, ETH_ALEN);
}

static inline void eth_hw_addr_random(struct net_device *dev)
{
    dev->addr_assign_type |= NET_ADDR_RANDOM;
    eth_random_addr(dev->dev_addr);
}

static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
{
    const u16 *a = (const u16 *) addr1;
    const u16 *b = (const u16 *) addr2;

    BUILD_BUG_ON(ETH_ALEN != 6);
    return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
}

static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
{
    return !compare_ether_addr(addr1, addr2);
}

static inline unsigned long zap_last_2bytes(unsigned long value)
{
#ifdef __BIG_ENDIAN
    return value >> 16;
#else
    return value << 16;
#endif
}

static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
                       const u8 addr2[6+2])
{
#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
    unsigned long fold = ((*(unsigned long *)addr1) ^
                  (*(unsigned long *)addr2));

    if (sizeof(fold) == 8)
        return zap_last_2bytes(fold) == 0;

    fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
                (*(unsigned long *)(addr2 + 4)));
    return fold == 0;
#else
    return ether_addr_equal(addr1, addr2);
#endif
}

static inline bool is_etherdev_addr(const struct net_device *dev,
                    const u8 addr[6 + 2])
{
    struct netdev_hw_addr *ha;
    bool res = false;

    rcu_read_lock();
    for_each_dev_addr(dev, ha) {
        res = ether_addr_equal_64bits(addr, ha->addr);
        if (res)
            break;
    }
    rcu_read_unlock();
    return res;
}
#endif  /* __KERNEL__ */

static inline unsigned long compare_ether_header(const void *a, const void *b)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
    unsigned long fold;

    /*
     * We want to compare 14 bytes:
     *  [a0 ... a13] ^ [b0 ... b13]
     * Use two long XOR, ORed together, with an overlap of two bytes.
     *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
     *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
     * This means the [a6 a7] ^ [b6 b7] part is done two times.
    */
    fold = *(unsigned long *)a ^ *(unsigned long *)b;
    fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
    return fold;
#else
    u32 *a32 = (u32 *)((u8 *)a + 2);
    u32 *b32 = (u32 *)((u8 *)b + 2);

    return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
           (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
#endif
}

#endif  /* _LINUX_ETHERDEVICE_H */