Line data Source code
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_mq(int sizeof_priv, unsigned int queue_count);
52 : #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
53 :
54 : /**
55 : * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
56 : * @addr: Pointer to a six-byte array containing the Ethernet address
57 : *
58 : * Return true if the address is all zeroes.
59 : */
60 : static inline int is_zero_ether_addr(const u8 *addr)
61 : {
62 2 : return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
63 : }
64 :
65 : /**
66 : * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
67 : * @addr: Pointer to a six-byte array containing the Ethernet address
68 : *
69 : * Return true if the address is a multicast address.
70 : * By definition the broadcast address is also a multicast address.
71 : */
72 : static inline int is_multicast_ether_addr(const u8 *addr)
73 : {
74 2 : return (0x01 & addr[0]);
75 : }
76 :
77 : /**
78 : * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
79 : * @addr: Pointer to a six-byte array containing the Ethernet address
80 : *
81 : * Return true if the address is a local address.
82 : */
83 : static inline int is_local_ether_addr(const u8 *addr)
84 : {
85 : return (0x02 & addr[0]);
86 : }
87 :
88 : /**
89 : * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
90 : * @addr: Pointer to a six-byte array containing the Ethernet address
91 : *
92 : * Return true if the address is the broadcast address.
93 : */
94 : static inline int is_broadcast_ether_addr(const u8 *addr)
95 : {
96 : return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
97 : }
98 :
99 : /**
100 : * is_valid_ether_addr - Determine if the given Ethernet address is valid
101 : * @addr: Pointer to a six-byte array containing the Ethernet address
102 : *
103 : * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
104 : * a multicast address, and is not FF:FF:FF:FF:FF:FF.
105 : *
106 : * Return true if the address is valid.
107 : */
108 : static inline int is_valid_ether_addr(const u8 *addr)
109 : {
110 2 : /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
111 2 : * explicitly check for it here. */
112 28 : return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
113 : }
114 :
115 : /**
116 : * random_ether_addr - Generate software assigned random Ethernet address
117 : * @addr: Pointer to a six-byte array containing the Ethernet address
118 : *
119 : * Generate a random Ethernet address (MAC) that is not multicast
120 : * and has the local assigned bit set.
121 : */
122 : static inline void random_ether_addr(u8 *addr)
123 : {
124 : get_random_bytes (addr, ETH_ALEN);
125 : addr [0] &= 0xfe; /* clear multicast bit */
126 : addr [0] |= 0x02; /* set local assignment bit (IEEE802) */
127 : }
128 :
129 : /**
130 : * compare_ether_addr - Compare two Ethernet addresses
131 : * @addr1: Pointer to a six-byte array containing the Ethernet address
132 : * @addr2: Pointer other six-byte array containing the Ethernet address
133 : *
134 : * Compare two ethernet addresses, returns 0 if equal
135 : */
136 : static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
137 : {
138 : const u16 *a = (const u16 *) addr1;
139 : const u16 *b = (const u16 *) addr2;
140 :
141 : BUILD_BUG_ON(ETH_ALEN != 6);
142 : return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
143 : }
144 :
145 : static inline unsigned long zap_last_2bytes(unsigned long value)
146 : {
147 : #ifdef __BIG_ENDIAN
148 : return value >> 16;
149 : #else
150 : return value << 16;
151 : #endif
152 : }
153 :
154 : /**
155 : * compare_ether_addr_64bits - Compare two Ethernet addresses
156 : * @addr1: Pointer to an array of 8 bytes
157 : * @addr2: Pointer to an other array of 8 bytes
158 : *
159 : * Compare two ethernet addresses, returns 0 if equal.
160 : * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional
161 : * branches, and possibly long word memory accesses on CPU allowing cheap
162 : * unaligned memory reads.
163 : * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2}
164 : *
165 : * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits.
166 : */
167 :
168 : static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2],
169 : const u8 addr2[6+2])
170 : {
171 : #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
172 : unsigned long fold = ((*(unsigned long *)addr1) ^
173 : (*(unsigned long *)addr2));
174 :
175 : if (sizeof(fold) == 8)
176 : return zap_last_2bytes(fold) != 0;
177 :
178 : fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
179 : (*(unsigned long *)(addr2 + 4)));
180 : return fold != 0;
181 : #else
182 : return compare_ether_addr(addr1, addr2);
183 : #endif
184 : }
185 :
186 : /**
187 : * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
188 : * @dev: Pointer to a device structure
189 : * @addr: Pointer to a six-byte array containing the Ethernet address
190 : *
191 : * Compare passed address with all addresses of the device. Return true if the
192 : * address if one of the device addresses.
193 : *
194 : * Note that this function calls compare_ether_addr_64bits() so take care of
195 : * the right padding.
196 : */
197 : static inline bool is_etherdev_addr(const struct net_device *dev,
198 : const u8 addr[6 + 2])
199 : {
200 : struct netdev_hw_addr *ha;
201 : int res = 1;
202 :
203 : rcu_read_lock();
204 : for_each_dev_addr(dev, ha) {
205 : res = compare_ether_addr_64bits(addr, ha->addr);
206 : if (!res)
207 : break;
208 : }
209 : rcu_read_unlock();
210 : return !res;
211 : }
212 : #endif /* __KERNEL__ */
213 :
214 : /**
215 : * compare_ether_header - Compare two Ethernet headers
216 : * @a: Pointer to Ethernet header
217 : * @b: Pointer to Ethernet header
218 : *
219 : * Compare two ethernet headers, returns 0 if equal.
220 : * This assumes that the network header (i.e., IP header) is 4-byte
221 : * aligned OR the platform can handle unaligned access. This is the
222 : * case for all packets coming into netif_receive_skb or similar
223 : * entry points.
224 : */
225 :
226 : static inline int compare_ether_header(const void *a, const void *b)
227 : {
228 : u32 *a32 = (u32 *)((u8 *)a + 2);
229 : u32 *b32 = (u32 *)((u8 *)b + 2);
230 :
231 : return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
232 : (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
233 : }
234 :
235 : #endif /* _LINUX_ETHERDEVICE_H */
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