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, <waltje@uWalt.NL.Mugnet.ORG>
12 *
13 * Relocated to include/linux where it belongs by Alan Cox
14 * <gw4pts@gw4pts.ampr.org>
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 * WARNING: This move may well be temporary. This file will get merged with others RSN.
22 *
23 */
24 #ifndef _LINUX_ETHERDEVICE_H
25 #define _LINUX_ETHERDEVICE_H
26
27 #include <linux/if_ether.h>
28 #include <linux/netdevice.h>
29 #include <linux/random.h>
30 #include <asm/unaligned.h>
31
32 #ifdef __KERNEL__
33 extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
34 extern const struct header_ops eth_header_ops;
35
36 extern int eth_header(struct sk_buff *skb, struct net_device *dev,
37 unsigned short type,
38 const void *daddr, const void *saddr, unsigned len);
39 extern int eth_rebuild_header(struct sk_buff *skb);
40 extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
41 extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh);
42 extern void eth_header_cache_update(struct hh_cache *hh,
43 const struct net_device *dev,
44 const unsigned char *haddr);
45 extern int eth_mac_addr(struct net_device *dev, void *p);
46 extern int eth_change_mtu(struct net_device *dev, int new_mtu);
47 extern int eth_validate_addr(struct net_device *dev);
48
49
50
51 extern 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 /**
57 * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
58 * @addr: Pointer to a six-byte array containing the Ethernet address
59 *
60 * Return true if the address is all zeroes.
61 */
is_zero_ether_addr(const u8 * addr)62 static inline int is_zero_ether_addr(const u8 *addr)
63 {
64 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
65 }
66
67 /**
68 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
69 * @addr: Pointer to a six-byte array containing the Ethernet address
70 *
71 * Return true if the address is a multicast address.
72 * By definition the broadcast address is also a multicast address.
73 */
is_multicast_ether_addr(const u8 * addr)74 static inline int is_multicast_ether_addr(const u8 *addr)
75 {
76 return 0x01 & addr[0];
77 }
78
79 /**
80 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
81 * @addr: Pointer to a six-byte array containing the Ethernet address
82 *
83 * Return true if the address is a local address.
84 */
is_local_ether_addr(const u8 * addr)85 static inline int is_local_ether_addr(const u8 *addr)
86 {
87 return 0x02 & addr[0];
88 }
89
90 /**
91 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
92 * @addr: Pointer to a six-byte array containing the Ethernet address
93 *
94 * Return true if the address is the broadcast address.
95 */
is_broadcast_ether_addr(const u8 * addr)96 static inline int is_broadcast_ether_addr(const u8 *addr)
97 {
98 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
99 }
100
101 /**
102 * is_unicast_ether_addr - Determine if the Ethernet address is unicast
103 * @addr: Pointer to a six-byte array containing the Ethernet address
104 *
105 * Return true if the address is a unicast address.
106 */
is_unicast_ether_addr(const u8 * addr)107 static inline int is_unicast_ether_addr(const u8 *addr)
108 {
109 return !is_multicast_ether_addr(addr);
110 }
111
112 /**
113 * is_valid_ether_addr - Determine if the given Ethernet address is valid
114 * @addr: Pointer to a six-byte array containing the Ethernet address
115 *
116 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
117 * a multicast address, and is not FF:FF:FF:FF:FF:FF.
118 *
119 * Return true if the address is valid.
120 */
is_valid_ether_addr(const u8 * addr)121 static inline int is_valid_ether_addr(const u8 *addr)
122 {
123 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
124 * explicitly check for it here. */
125 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
126 }
127
128 /**
129 * random_ether_addr - Generate software assigned random Ethernet address
130 * @addr: Pointer to a six-byte array containing the Ethernet address
131 *
132 * Generate a random Ethernet address (MAC) that is not multicast
133 * and has the local assigned bit set.
134 */
random_ether_addr(u8 * addr)135 static inline void random_ether_addr(u8 *addr)
136 {
137 get_random_bytes (addr, ETH_ALEN);
138 addr [0] &= 0xfe; /* clear multicast bit */
139 addr [0] |= 0x02; /* set local assignment bit (IEEE802) */
140 }
141
142 /**
143 * dev_hw_addr_random - Create random MAC and set device flag
144 * @dev: pointer to net_device structure
145 * @hwaddr: Pointer to a six-byte array containing the Ethernet address
146 *
147 * Generate random MAC to be used by a device and set addr_assign_type
148 * so the state can be read by sysfs and be used by udev.
149 */
dev_hw_addr_random(struct net_device * dev,u8 * hwaddr)150 static inline void dev_hw_addr_random(struct net_device *dev, u8 *hwaddr)
151 {
152 dev->addr_assign_type |= NET_ADDR_RANDOM;
153 random_ether_addr(hwaddr);
154 }
155
156 /**
157 * compare_ether_addr - Compare two Ethernet addresses
158 * @addr1: Pointer to a six-byte array containing the Ethernet address
159 * @addr2: Pointer other six-byte array containing the Ethernet address
160 *
161 * Compare two ethernet addresses, returns 0 if equal
162 */
compare_ether_addr(const u8 * addr1,const u8 * addr2)163 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
164 {
165 const u16 *a = (const u16 *) addr1;
166 const u16 *b = (const u16 *) addr2;
167
168 BUILD_BUG_ON(ETH_ALEN != 6);
169 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
170 }
171
zap_last_2bytes(unsigned long value)172 static inline unsigned long zap_last_2bytes(unsigned long value)
173 {
174 #ifdef __BIG_ENDIAN
175 return value >> 16;
176 #else
177 return value << 16;
178 #endif
179 }
180
181 /**
182 * compare_ether_addr_64bits - Compare two Ethernet addresses
183 * @addr1: Pointer to an array of 8 bytes
184 * @addr2: Pointer to an other array of 8 bytes
185 *
186 * Compare two ethernet addresses, returns 0 if equal.
187 * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional
188 * branches, and possibly long word memory accesses on CPU allowing cheap
189 * unaligned memory reads.
190 * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2}
191 *
192 * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits.
193 */
194
compare_ether_addr_64bits(const u8 addr1[6+2],const u8 addr2[6+2])195 static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2],
196 const u8 addr2[6+2])
197 {
198 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
199 unsigned long fold = ((*(unsigned long *)addr1) ^
200 (*(unsigned long *)addr2));
201
202 if (sizeof(fold) == 8)
203 return zap_last_2bytes(fold) != 0;
204
205 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
206 (*(unsigned long *)(addr2 + 4)));
207 return fold != 0;
208 #else
209 return compare_ether_addr(addr1, addr2);
210 #endif
211 }
212
213 /**
214 * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
215 * @dev: Pointer to a device structure
216 * @addr: Pointer to a six-byte array containing the Ethernet address
217 *
218 * Compare passed address with all addresses of the device. Return true if the
219 * address if one of the device addresses.
220 *
221 * Note that this function calls compare_ether_addr_64bits() so take care of
222 * the right padding.
223 */
is_etherdev_addr(const struct net_device * dev,const u8 addr[6+2])224 static inline bool is_etherdev_addr(const struct net_device *dev,
225 const u8 addr[6 + 2])
226 {
227 struct netdev_hw_addr *ha;
228 int res = 1;
229
230 rcu_read_lock();
231 for_each_dev_addr(dev, ha) {
232 res = compare_ether_addr_64bits(addr, ha->addr);
233 if (!res)
234 break;
235 }
236 rcu_read_unlock();
237 return !res;
238 }
239 #endif /* __KERNEL__ */
240
241 /**
242 * compare_ether_header - Compare two Ethernet headers
243 * @a: Pointer to Ethernet header
244 * @b: Pointer to Ethernet header
245 *
246 * Compare two ethernet headers, returns 0 if equal.
247 * This assumes that the network header (i.e., IP header) is 4-byte
248 * aligned OR the platform can handle unaligned access. This is the
249 * case for all packets coming into netif_receive_skb or similar
250 * entry points.
251 */
252
compare_ether_header(const void * a,const void * b)253 static inline unsigned long compare_ether_header(const void *a, const void *b)
254 {
255 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
256 unsigned long fold;
257
258 /*
259 * We want to compare 14 bytes:
260 * [a0 ... a13] ^ [b0 ... b13]
261 * Use two long XOR, ORed together, with an overlap of two bytes.
262 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] |
263 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13]
264 * This means the [a6 a7] ^ [b6 b7] part is done two times.
265 */
266 fold = *(unsigned long *)a ^ *(unsigned long *)b;
267 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
268 return fold;
269 #else
270 u32 *a32 = (u32 *)((u8 *)a + 2);
271 u32 *b32 = (u32 *)((u8 *)b + 2);
272
273 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
274 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
275 #endif
276 }
277
278 #endif /* _LINUX_ETHERDEVICE_H */
279