projects/linux·blob v3.9-rc4 · refs

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1/*
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.
5 *
6 * Definitions for the Ethernet handlers.
7 *
8 * Version: @(#)eth.h 1.0.4 05/13/93
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <[email protected]>
12 *
13 * Relocated to include/linux where it belongs by Alan Cox
14 * <[email protected]>
15 *
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.
20 *
21 */
22#ifndef _LINUX_ETHERDEVICE_H
23#define _LINUX_ETHERDEVICE_H
24
25#include <linux/if_ether.h>
26#include <linux/netdevice.h>
27#include <linux/random.h>
28#include <asm/unaligned.h>
29
30#ifdef __KERNEL__
31extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
32extern const struct header_ops eth_header_ops;
33
34extern int eth_header(struct sk_buff *skb, struct net_device *dev,
35 unsigned short type,
36 const void *daddr, const void *saddr, unsigned len);
37extern int eth_rebuild_header(struct sk_buff *skb);
38extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
39extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
40extern void eth_header_cache_update(struct hh_cache *hh,
41 const struct net_device *dev,
42 const unsigned char *haddr);
43extern int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
44extern void eth_commit_mac_addr_change(struct net_device *dev, void *p);
45extern int eth_mac_addr(struct net_device *dev, void *p);
46extern int eth_change_mtu(struct net_device *dev, int new_mtu);
47extern int eth_validate_addr(struct net_device *dev);
48
49
50
51extern struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
52 unsigned int rxqs);
53#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
54#define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
55
56/* Reserved Ethernet Addresses per IEEE 802.1Q */
57static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
58{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
59
60/**
61 * is_link_local_ether_addr - Determine if given Ethernet address is link-local
62 * @addr: Pointer to a six-byte array containing the Ethernet address
63 *
64 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
65 * IEEE 802.1Q 8.6.3 Frame filtering.
66 */
67static inline bool is_link_local_ether_addr(const u8 *addr)
68{
69 __be16 *a = (__be16 *)addr;
70 static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
71 static const __be16 m = cpu_to_be16(0xfff0);
72
73 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
74}
75
76/**
77 * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
78 * @addr: Pointer to a six-byte array containing the Ethernet address
79 *
80 * Return true if the address is all zeroes.
81 */
82static inline bool is_zero_ether_addr(const u8 *addr)
83{
84 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
85}
86
87/**
88 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
89 * @addr: Pointer to a six-byte array containing the Ethernet address
90 *
91 * Return true if the address is a multicast address.
92 * By definition the broadcast address is also a multicast address.
93 */
94static inline bool is_multicast_ether_addr(const u8 *addr)
95{
96 return 0x01 & addr[0];
97}
98
99/**
100 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
101 * @addr: Pointer to a six-byte array containing the Ethernet address
102 *
103 * Return true if the address is a local address.
104 */
105static inline bool is_local_ether_addr(const u8 *addr)
106{
107 return 0x02 & addr[0];
108}
109
110/**
111 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
112 * @addr: Pointer to a six-byte array containing the Ethernet address
113 *
114 * Return true if the address is the broadcast address.
115 */
116static inline bool is_broadcast_ether_addr(const u8 *addr)
117{
118 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
119}
120
121/**
122 * is_unicast_ether_addr - Determine if the Ethernet address is unicast
123 * @addr: Pointer to a six-byte array containing the Ethernet address
124 *
125 * Return true if the address is a unicast address.
126 */
127static inline bool is_unicast_ether_addr(const u8 *addr)
128{
129 return !is_multicast_ether_addr(addr);
130}
131
132/**
133 * is_valid_ether_addr - Determine if the given Ethernet address is valid
134 * @addr: Pointer to a six-byte array containing the Ethernet address
135 *
136 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
137 * a multicast address, and is not FF:FF:FF:FF:FF:FF.
138 *
139 * Return true if the address is valid.
140 */
141static inline bool is_valid_ether_addr(const u8 *addr)
142{
143 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
144 * explicitly check for it here. */
145 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
146}
147
148/**
149 * eth_random_addr - Generate software assigned random Ethernet address
150 * @addr: Pointer to a six-byte array containing the Ethernet address
151 *
152 * Generate a random Ethernet address (MAC) that is not multicast
153 * and has the local assigned bit set.
154 */
155static inline void eth_random_addr(u8 *addr)
156{
157 get_random_bytes(addr, ETH_ALEN);
158 addr[0] &= 0xfe; /* clear multicast bit */
159 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */
160}
161
162#define random_ether_addr(addr) eth_random_addr(addr)
163
164/**
165 * eth_broadcast_addr - Assign broadcast address
166 * @addr: Pointer to a six-byte array containing the Ethernet address
167 *
168 * Assign the broadcast address to the given address array.
169 */
170static inline void eth_broadcast_addr(u8 *addr)
171{
172 memset(addr, 0xff, ETH_ALEN);
173}
174
175/**
176 * eth_zero_addr - Assign zero address
177 * @addr: Pointer to a six-byte array containing the Ethernet address
178 *
179 * Assign the zero address to the given address array.
180 */
181static inline void eth_zero_addr(u8 *addr)
182{
183 memset(addr, 0x00, ETH_ALEN);
184}
185
186/**
187 * eth_hw_addr_random - Generate software assigned random Ethernet and
188 * set device flag
189 * @dev: pointer to net_device structure
190 *
191 * Generate a random Ethernet address (MAC) to be used by a net device
192 * and set addr_assign_type so the state can be read by sysfs and be
193 * used by userspace.
194 */
195static inline void eth_hw_addr_random(struct net_device *dev)
196{
197 dev->addr_assign_type = NET_ADDR_RANDOM;
198 eth_random_addr(dev->dev_addr);
199}
200
201/**
202 * compare_ether_addr - Compare two Ethernet addresses
203 * @addr1: Pointer to a six-byte array containing the Ethernet address
204 * @addr2: Pointer other six-byte array containing the Ethernet address
205 *
206 * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise.
207 * Unlike memcmp(), it doesn't return a value suitable for sorting.
208 */
209static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
210{
211 const u16 *a = (const u16 *) addr1;
212 const u16 *b = (const u16 *) addr2;
213
214 BUILD_BUG_ON(ETH_ALEN != 6);
215 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
216}
217
218/**
219 * ether_addr_equal - Compare two Ethernet addresses
220 * @addr1: Pointer to a six-byte array containing the Ethernet address
221 * @addr2: Pointer other six-byte array containing the Ethernet address
222 *
223 * Compare two Ethernet addresses, returns true if equal
224 */
225static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
226{
227 return !compare_ether_addr(addr1, addr2);
228}
229
230static inline unsigned long zap_last_2bytes(unsigned long value)
231{
232#ifdef __BIG_ENDIAN
233 return value >> 16;
234#else
235 return value << 16;
236#endif
237}
238
239/**
240 * ether_addr_equal_64bits - Compare two Ethernet addresses
241 * @addr1: Pointer to an array of 8 bytes
242 * @addr2: Pointer to an other array of 8 bytes
243 *
244 * Compare two Ethernet addresses, returns true if equal, false otherwise.
245 *
246 * The function doesn't need any conditional branches and possibly uses
247 * word memory accesses on CPU allowing cheap unaligned memory reads.
248 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
249 *
250 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
251 */
252
253static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
254 const u8 addr2[6+2])
255{
256#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
257 unsigned long fold = ((*(unsigned long *)addr1) ^
258 (*(unsigned long *)addr2));
259
260 if (sizeof(fold) == 8)
261 return zap_last_2bytes(fold) == 0;
262
263 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
264 (*(unsigned long *)(addr2 + 4)));
265 return fold == 0;
266#else
267 return ether_addr_equal(addr1, addr2);
268#endif
269}
270
271/**
272 * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
273 * @dev: Pointer to a device structure
274 * @addr: Pointer to a six-byte array containing the Ethernet address
275 *
276 * Compare passed address with all addresses of the device. Return true if the
277 * address if one of the device addresses.
278 *
279 * Note that this function calls ether_addr_equal_64bits() so take care of
280 * the right padding.
281 */
282static inline bool is_etherdev_addr(const struct net_device *dev,
283 const u8 addr[6 + 2])
284{
285 struct netdev_hw_addr *ha;
286 bool res = false;
287
288 rcu_read_lock();
289 for_each_dev_addr(dev, ha) {
290 res = ether_addr_equal_64bits(addr, ha->addr);
291 if (res)
292 break;
293 }
294 rcu_read_unlock();
295 return res;
296}
297#endif /* __KERNEL__ */
298
299/**
300 * compare_ether_header - Compare two Ethernet headers
301 * @a: Pointer to Ethernet header
302 * @b: Pointer to Ethernet header
303 *
304 * Compare two Ethernet headers, returns 0 if equal.
305 * This assumes that the network header (i.e., IP header) is 4-byte
306 * aligned OR the platform can handle unaligned access. This is the
307 * case for all packets coming into netif_receive_skb or similar
308 * entry points.
309 */
310
311static inline unsigned long compare_ether_header(const void *a, const void *b)
312{
313#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
314 unsigned long fold;
315
316 /*
317 * We want to compare 14 bytes:
318 * [a0 ... a13] ^ [b0 ... b13]
319 * Use two long XOR, ORed together, with an overlap of two bytes.
320 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
321 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
322 * This means the [a6 a7] ^ [b6 b7] part is done two times.
323 */
324 fold = *(unsigned long *)a ^ *(unsigned long *)b;
325 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
326 return fold;
327#else
328 u32 *a32 = (u32 *)((u8 *)a + 2);
329 u32 *b32 = (u32 *)((u8 *)b + 2);
330
331 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
332 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
333#endif
334}
335
336#endif /* _LINUX_ETHERDEVICE_H */