2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. NET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Definitions for the Ethernet handlers.
8 * Version: @(#)eth.h 1.0.4 05/13/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Relocated to include/linux where it belongs by Alan Cox
14 * <gw4pts@gw4pts.ampr.org>
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
22 #ifndef _LINUX_ETHERDEVICE_H
23 #define _LINUX_ETHERDEVICE_H
25 #include <linux/if_ether.h>
26 #include <linux/netdevice.h>
27 #include <linux/random.h>
28 #include <asm/unaligned.h>
29 #include <asm/bitsperlong.h>
32 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
33 extern const struct header_ops eth_header_ops;
35 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
36 const void *daddr, const void *saddr, unsigned len);
37 int eth_rebuild_header(struct sk_buff *skb);
38 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
39 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
41 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
42 const unsigned char *haddr);
43 int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
44 void eth_commit_mac_addr_change(struct net_device *dev, void *p);
45 int eth_mac_addr(struct net_device *dev, void *p);
46 int eth_change_mtu(struct net_device *dev, int new_mtu);
47 int eth_validate_addr(struct net_device *dev);
49 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
51 #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
52 #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
54 /* Reserved Ethernet Addresses per IEEE 802.1Q */
55 static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
56 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
59 * is_link_local_ether_addr - Determine if given Ethernet address is link-local
60 * @addr: Pointer to a six-byte array containing the Ethernet address
62 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
63 * IEEE 802.1Q 8.6.3 Frame filtering.
65 static inline bool is_link_local_ether_addr(const u8 *addr)
67 __be16 *a = (__be16 *)addr;
68 static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
69 static const __be16 m = cpu_to_be16(0xfff0);
71 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
75 * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
76 * @addr: Pointer to a six-byte array containing the Ethernet address
78 * Return true if the address is all zeroes.
80 static inline bool is_zero_ether_addr(const u8 *addr)
82 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
86 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
87 * @addr: Pointer to a six-byte array containing the Ethernet address
89 * Return true if the address is a multicast address.
90 * By definition the broadcast address is also a multicast address.
92 static inline bool is_multicast_ether_addr(const u8 *addr)
94 return 0x01 & addr[0];
98 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
99 * @addr: Pointer to a six-byte array containing the Ethernet address
101 * Return true if the address is a local address.
103 static inline bool is_local_ether_addr(const u8 *addr)
105 return 0x02 & addr[0];
109 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
110 * @addr: Pointer to a six-byte array containing the Ethernet address
112 * Return true if the address is the broadcast address.
114 static inline bool is_broadcast_ether_addr(const u8 *addr)
116 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
120 * is_unicast_ether_addr - Determine if the Ethernet address is unicast
121 * @addr: Pointer to a six-byte array containing the Ethernet address
123 * Return true if the address is a unicast address.
125 static inline bool is_unicast_ether_addr(const u8 *addr)
127 return !is_multicast_ether_addr(addr);
131 * is_valid_ether_addr - Determine if the given Ethernet address is valid
132 * @addr: Pointer to a six-byte array containing the Ethernet address
134 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
135 * a multicast address, and is not FF:FF:FF:FF:FF:FF.
137 * Return true if the address is valid.
139 static inline bool is_valid_ether_addr(const u8 *addr)
141 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
142 * explicitly check for it here. */
143 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
147 * eth_random_addr - Generate software assigned random Ethernet address
148 * @addr: Pointer to a six-byte array containing the Ethernet address
150 * Generate a random Ethernet address (MAC) that is not multicast
151 * and has the local assigned bit set.
153 static inline void eth_random_addr(u8 *addr)
155 get_random_bytes(addr, ETH_ALEN);
156 addr[0] &= 0xfe; /* clear multicast bit */
157 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */
160 #define random_ether_addr(addr) eth_random_addr(addr)
163 * eth_broadcast_addr - Assign broadcast address
164 * @addr: Pointer to a six-byte array containing the Ethernet address
166 * Assign the broadcast address to the given address array.
168 static inline void eth_broadcast_addr(u8 *addr)
170 memset(addr, 0xff, ETH_ALEN);
174 * eth_zero_addr - Assign zero address
175 * @addr: Pointer to a six-byte array containing the Ethernet address
177 * Assign the zero address to the given address array.
179 static inline void eth_zero_addr(u8 *addr)
181 memset(addr, 0x00, ETH_ALEN);
185 * eth_hw_addr_random - Generate software assigned random Ethernet and
187 * @dev: pointer to net_device structure
189 * Generate a random Ethernet address (MAC) to be used by a net device
190 * and set addr_assign_type so the state can be read by sysfs and be
193 static inline void eth_hw_addr_random(struct net_device *dev)
195 dev->addr_assign_type = NET_ADDR_RANDOM;
196 eth_random_addr(dev->dev_addr);
200 * eth_hw_addr_inherit - Copy dev_addr from another net_device
201 * @dst: pointer to net_device to copy dev_addr to
202 * @src: pointer to net_device to copy dev_addr from
204 * Copy the Ethernet address from one net_device to another along with
205 * the address attributes (addr_assign_type).
207 static inline void eth_hw_addr_inherit(struct net_device *dst,
208 struct net_device *src)
210 dst->addr_assign_type = src->addr_assign_type;
211 memcpy(dst->dev_addr, src->dev_addr, ETH_ALEN);
215 * ether_addr_equal - Compare two Ethernet addresses
216 * @addr1: Pointer to a six-byte array containing the Ethernet address
217 * @addr2: Pointer other six-byte array containing the Ethernet address
219 * Compare two Ethernet addresses, returns true if equal
221 * Please note: addr1 & addr2 must both be aligned to u16.
223 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
225 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
226 u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
227 ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
231 const u16 *a = (const u16 *)addr1;
232 const u16 *b = (const u16 *)addr2;
234 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
239 * ether_addr_equal_64bits - Compare two Ethernet addresses
240 * @addr1: Pointer to an array of 8 bytes
241 * @addr2: Pointer to an other array of 8 bytes
243 * Compare two Ethernet addresses, returns true if equal, false otherwise.
245 * The function doesn't need any conditional branches and possibly uses
246 * word memory accesses on CPU allowing cheap unaligned memory reads.
247 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
249 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
252 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
255 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
256 u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
259 return (fold >> 16) == 0;
261 return (fold << 16) == 0;
264 return ether_addr_equal(addr1, addr2);
269 * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
270 * @dev: Pointer to a device structure
271 * @addr: Pointer to a six-byte array containing the Ethernet address
273 * Compare passed address with all addresses of the device. Return true if the
274 * address if one of the device addresses.
276 * Note that this function calls ether_addr_equal_64bits() so take care of
279 static inline bool is_etherdev_addr(const struct net_device *dev,
280 const u8 addr[6 + 2])
282 struct netdev_hw_addr *ha;
286 for_each_dev_addr(dev, ha) {
287 res = ether_addr_equal_64bits(addr, ha->addr);
294 #endif /* __KERNEL__ */
297 * compare_ether_header - Compare two Ethernet headers
298 * @a: Pointer to Ethernet header
299 * @b: Pointer to Ethernet header
301 * Compare two Ethernet headers, returns 0 if equal.
302 * This assumes that the network header (i.e., IP header) is 4-byte
303 * aligned OR the platform can handle unaligned access. This is the
304 * case for all packets coming into netif_receive_skb or similar
308 static inline unsigned long compare_ether_header(const void *a, const void *b)
310 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
314 * We want to compare 14 bytes:
315 * [a0 ... a13] ^ [b0 ... b13]
316 * Use two long XOR, ORed together, with an overlap of two bytes.
317 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
318 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
319 * This means the [a6 a7] ^ [b6 b7] part is done two times.
321 fold = *(unsigned long *)a ^ *(unsigned long *)b;
322 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
325 u32 *a32 = (u32 *)((u8 *)a + 2);
326 u32 *b32 = (u32 *)((u8 *)b + 2);
328 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
329 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
333 #endif /* _LINUX_ETHERDEVICE_H */