blob: 1080d112de52e1193f962c904cb57cccbaa3d4df (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
/**
* @file IxEthDBLearning.c
*
* @par
* IXP400 SW Release version 2.0
*
* -- Copyright Notice --
*
* @par
* Copyright 2001-2005, Intel Corporation.
* All rights reserved.
*
* @par
* SPDX-License-Identifier: BSD-3-Clause
* @par
* -- End of Copyright Notice --
*/
#include "IxEthDB_p.h"
/**
* @brief hashes the mac address in a mac descriptor with a XOR function
*
* @param entry pointer to a mac descriptor to be hashed
*
* This function only extracts the mac address and employs ixEthDBKeyXORHash()
* to do the actual hashing.
* Used only to add a whole entry to a hash table, as opposed to searching which
* takes only a key and uses the key hashing directly.
*
* @see ixEthDBKeyXORHash()
*
* @return the hash value
*
* @internal
*/
UINT32 ixEthDBEntryXORHash(void *entry)
{
MacDescriptor *descriptor = (MacDescriptor *) entry;
return ixEthDBKeyXORHash(descriptor->macAddress);
}
/**
* @brief hashes a mac address
*
* @param key pointer to a 6 byte structure (typically an IxEthDBMacAddr pointer)
* to be hashed
*
* Given a 6 bytes MAC address, the hash used is:
*
* hash(MAC[0:5]) = MAC[0:1] ^ MAC[2:3] ^ MAC[4:5]
*
* Used by the hash table to search and remove entries based
* solely on their keys (mac addresses).
*
* @return the hash value
*
* @internal
*/
UINT32 ixEthDBKeyXORHash(void *key)
{
UINT32 hashValue;
UINT8 *value = (UINT8 *) key;
hashValue = (value[5] << 8) | value[4];
hashValue ^= (value[3] << 8) | value[2];
hashValue ^= (value[1] << 8) | value[0];
return hashValue;
}
/**
* @brief mac descriptor match function
*
* @param reference mac address (typically an IxEthDBMacAddr pointer) structure
* @param entry pointer to a mac descriptor whose key (mac address) is to be
* matched against the reference key
*
* Used by the hash table to retrieve entries. Hashing entries can produce
* collisions, i.e. descriptors with different mac addresses and the same
* hash value, where this function is used to differentiate entries.
*
* @retval true if the entry matches the reference key (equal addresses)
* @retval false if the entry does not match the reference key
*
* @internal
*/
BOOL ixEthDBAddressMatch(void *reference, void *entry)
{
return (ixEthDBAddressCompare(reference, ((MacDescriptor *) entry)->macAddress) == 0);
}
/**
* @brief compares two mac addresses
*
* @param mac1 first mac address to compare
* @param mac2 second mac address to compare
*
* This comparison works in a similar way to strcmp, producing similar results.
* Used to insert values keyed on mac addresses into binary search trees.
*
* @retval -1 if mac1 < mac2
* @retval 0 if ma1 == mac2
* @retval 1 if mac1 > mac2
*/
UINT32 ixEthDBAddressCompare(UINT8 *mac1, UINT8 *mac2)
{
UINT32 local_index;
for (local_index = 0 ; local_index < IX_IEEE803_MAC_ADDRESS_SIZE ; local_index++)
{
if (mac1[local_index] > mac2[local_index])
{
return 1;
}
else if (mac1[local_index] < mac2[local_index])
{
return -1;
}
}
return 0;
}
|
