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
|
/*++
Copyright (C) Microsoft Corporation, 1990 - 1999
Module Name:
dictlib.c
Abstract:
Support library for maintaining a dictionary list (list of objects
referenced by a key value).
Environment:
kernel mode only
Notes:
This module generates a static library
Revision History:
--*/
#include <ntddk.h>
#include <classpnp.h>
#define DICTIONARY_SIGNATURE 'tciD'
#pragma warning(push)
#pragma warning(disable:4200) // nonstandard extension used : zero-sized array in struct/union
struct _DICTIONARY_HEADER {
PDICTIONARY_HEADER Next;
ULONGLONG Key;
UCHAR Data[0];
};
#pragma warning(pop)
struct _DICTIONARY_HEADER;
typedef struct _DICTIONARY_HEADER DICTIONARY_HEADER, *PDICTIONARY_HEADER;
VOID
InitializeDictionary(
IN PDICTIONARY Dictionary
)
{
RtlZeroMemory(Dictionary, sizeof(DICTIONARY));
Dictionary->Signature = DICTIONARY_SIGNATURE;
KeInitializeSpinLock(&Dictionary->SpinLock);
return;
}
BOOLEAN
TestDictionarySignature(
IN PDICTIONARY Dictionary
)
{
return Dictionary->Signature == DICTIONARY_SIGNATURE;
}
NTSTATUS
AllocateDictionaryEntry(
IN PDICTIONARY Dictionary,
IN ULONGLONG Key,
_In_range_(0, sizeof(FILE_OBJECT_EXTENSION)) IN ULONG Size,
IN ULONG Tag,
OUT PVOID *Entry
)
{
PDICTIONARY_HEADER header;
KIRQL oldIrql;
PDICTIONARY_HEADER *entry;
NTSTATUS status = STATUS_SUCCESS;
*Entry = NULL;
header = ExAllocatePoolZero(NonPagedPoolNx,
Size + sizeof(DICTIONARY_HEADER),
Tag);
if(header == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
header->Key = Key;
//
// Find the correct location for this entry in the dictionary.
//
KeAcquireSpinLock(&(Dictionary->SpinLock), &oldIrql);
TRY {
entry = &(Dictionary->List);
while(*entry != NULL) {
if((*entry)->Key == Key) {
//
// Dictionary must have unique keys.
//
status = STATUS_OBJECT_NAME_COLLISION;
LEAVE;
} else if ((*entry)->Key < Key) {
//
// We will go ahead and insert the key in here.
//
break;
} else {
entry = &((*entry)->Next);
}
}
//
// If we make it here then we will go ahead and do the insertion.
//
header->Next = *entry;
*entry = header;
} FINALLY {
KeReleaseSpinLock(&(Dictionary->SpinLock), oldIrql);
if(!NT_SUCCESS(status)) {
FREE_POOL(header);
} else {
*Entry = (PVOID) header->Data;
}
}
return status;
}
PVOID
GetDictionaryEntry(
IN PDICTIONARY Dictionary,
IN ULONGLONG Key
)
{
PDICTIONARY_HEADER entry;
PVOID data;
KIRQL oldIrql;
data = NULL;
KeAcquireSpinLock(&(Dictionary->SpinLock), &oldIrql);
entry = Dictionary->List;
while (entry != NULL) {
if (entry->Key == Key) {
data = entry->Data;
break;
} else {
entry = entry->Next;
}
}
KeReleaseSpinLock(&(Dictionary->SpinLock), oldIrql);
return data;
}
VOID
FreeDictionaryEntry(
IN PDICTIONARY Dictionary,
IN PVOID Entry
)
{
PDICTIONARY_HEADER header;
PDICTIONARY_HEADER *entry;
KIRQL oldIrql;
BOOLEAN found;
found = FALSE;
header = CONTAINING_RECORD(Entry, DICTIONARY_HEADER, Data);
KeAcquireSpinLock(&(Dictionary->SpinLock), &oldIrql);
entry = &(Dictionary->List);
while(*entry != NULL) {
if(*entry == header) {
*entry = header->Next;
found = TRUE;
break;
} else {
entry = &(*entry)->Next;
}
}
KeReleaseSpinLock(&(Dictionary->SpinLock), oldIrql);
//
// calling this w/an invalid pointer invalidates the dictionary system,
// so NT_ASSERT() that we never try to Free something not in the list
//
NT_ASSERT(found);
if (found) {
FREE_POOL(header);
}
return;
}
|
