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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2012 Microsoft Corporation. All Rights Reserved.
//
// Module Name:
// HelperFunctions_MACAddress.cpp
//
// Abstract:
// This module contains functions which assist in actions pertaining to MAC Addresses.
//
// Naming Convention:
//
// <Scope><Module><Object><Action><Modifier>
//
// i.e.
//
// <Scope>
// {
// - Function is likely visible to other modules
// }
// <Module>
// {
// Hlpr - Function is from HelperFunctions_* Modules.
// }
// <Object>
// {
// EthernetMACAddressString - Function pertains to null terminated wide character string
// representaions of Ethernet MAC Addresses
// }
// <Action>
// {
// To - Function converts from one type to another
// Is - Function compares values.
// }
// <Modifier>
// {
// ValidFormat - Function validates condition.
// Value - Function acts on a value.
// }
//
// Private Functions:
//
// Public Functions:
// HlprEthernetMACAddressStringIsValidFormat(),
// HlprEthernetMACAddressStringToValue(),
//
// Author:
// Dusty Harper (DHarper)
//
// Revision History:
//
// [ Month ][Day] [Year] - [Revision]-[ Comments ]
// May 01, 2010 - 1.0 - Creation
// December 13, 2013 - 1.1 - Add offset to check in
// HlprEthernetMACAddressStringToValue
//
////////////////////////////////////////////////////////////////////////////////////////////////////
#include "HelperFunctions_Include.h"
/**
@helper_function="HlprEthernetMACAddressStringIsValidFormat"
Purpose: Determine if a string may be an Ethernet MAC address by verifying the string: <br>
is at least 17 characters <br>
has at least 5 colons(':') or hyphens('-') <br>
<br>
Notes: <br>
<br>
MSDN_Ref: <br>
*/
BOOLEAN HlprEthernetMACAddressStringIsValidFormat(_In_ PCWSTR pEthernetMACAddressString)
{
BOOLEAN isEthernetMACAddress = FALSE;
if(pEthernetMACAddressString)
{
UINT32 status = NO_ERROR;
size_t stringLength = 0;
status = StringCchLength(pEthernetMACAddressString,
STRSAFE_MAX_CCH,
&stringLength);
if(status != ERROR_SUCCESS)
{
HlprLogError(L"HlprEthernetMACAddressStringIsValidFormat : StringCchLength() [status: %#x]",
status);
HLPR_BAIL;
}
else if(stringLength <= IEEE_802_ADDRESS_STRING_BUFFER)
{
if(wcschr(pEthernetMACAddressString,
L':'))
{
UINT32 numColons = 0;
for(UINT32 index = 0;
index < stringLength;
index++)
{
if(pEthernetMACAddressString[index] == L':')
numColons++;
}
if(numColons == 5)
isEthernetMACAddress = TRUE;
}
else
{
if(wcschr(pEthernetMACAddressString,
L'-'))
{
UINT32 numHyphens = 0;
for(UINT32 index = 0;
index < stringLength;
index++)
{
if(pEthernetMACAddressString[index] == L'-')
numHyphens++;
}
if(numHyphens == 5)
isEthernetMACAddress = TRUE;
}
}
}
}
HLPR_BAIL_LABEL:
if(!isEthernetMACAddress)
HlprLogError(L"HlprEthernetMACAddressStringIsValidFormat() [status: %#x][pEthernetMACAddressString: %s]",
ERROR_INVALID_DATA,
pEthernetMACAddressString);
return isEthernetMACAddress;
}
/**
@helper_function="HlprEthernetMACAddressStringToValue"
Purpose: Convert a string representing an Ethernet MAC Address to it's 6 BYTE value. <br>
<br>
Notes: <br>
<br>
MSDN_Ref: <br>
*/
_Success_(return == NO_ERROR)
UINT32 HlprEthernetMACAddressStringToValue(_In_ PCWSTR pEthernetMACAddressString,
_Inout_updates_all_(IEEE_802_ADDRESS_LENGTH) BYTE* pEthernetMACAddress)
{
UINT32 status = NO_ERROR;
if(pEthernetMACAddressString &&
HlprEthernetMACAddressStringIsValidFormat(pEthernetMACAddressString))
{
UINT32 offset = 0;
UINT32 bytePosition = 0x10;
ZeroMemory(pEthernetMACAddress,
IEEE_802_ADDRESS_LENGTH);
#pragma warning(push)
#pragma warning(disable: 26018) /// length validation occurs in HlprEthernetMACAddressStringIsValidFormat
for(UINT32 i = 0;
i < IEEE_802_ADDRESS_STRING_BUFFER && /// does not include '\0'
offset < IEEE_802_ADDRESS_LENGTH;
i++)
{
WCHAR character = pEthernetMACAddressString[i];
/// Validate every 3 character is either a ':' or a '-'
if((i + 1) % 3 == 0)
{
if(character != L':' &&
character != L'-')
{
status = ERROR_INVALID_DATA;
HlprLogError(L"HlprEthernetMACAddressStringToValue() [status: %#x][pEthernetMACAddressString: %s]",
status,
pEthernetMACAddressString);
HLPR_BAIL;
}
continue;
}
if(character >= L'0' &&
character <= L'9')
pEthernetMACAddress[offset] = (BYTE)(pEthernetMACAddress[offset] + ((character - L'0') * bytePosition));
else if(character >= L'a' &&
character <= L'f')
pEthernetMACAddress[offset] = (BYTE)(pEthernetMACAddress[offset] + ((character + 10 - L'a') * bytePosition));
else if(character >= L'A' &&
character <= L'F')
pEthernetMACAddress[offset] = (BYTE)(pEthernetMACAddress[offset] + ((character + 10 - L'A') * bytePosition));
else
{
status = ERROR_INVALID_DATA;
HlprLogError(L"HlprEthernetMACAddressStringToValue() [status: %#x][pEthernetMACAddressString: %s]",
status,
pEthernetMACAddressString);
HLPR_BAIL;
}
if(bytePosition == 1)
{
offset++;
bytePosition = 0x10;
}
else
bytePosition = 1;
}
#pragma warning(pop)
HLPR_BAIL_LABEL:
if(status != ERROR_SUCCESS)
ZeroMemory(pEthernetMACAddress,
IEEE_802_ADDRESS_LENGTH);
}
else
HlprLogError(L"HlprEthernetMACAddressStringToValue() [status: %#x][pEthernetMACAddressString: %s]",
status,
pEthernetMACAddressString);
return status;
}
|
