forked from yaosj2k/dnsforwarder
-
Notifications
You must be signed in to change notification settings - Fork 0
/
dnsparser.h
executable file
·245 lines (168 loc) · 7.98 KB
/
dnsparser.h
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
238
239
240
241
242
243
244
245
#ifndef _DNS_PARSER_H_
#define _DNS_PARSER_H_
#include <limits.h>
#include "common.h"
#include "dnsrelated.h"
#define GET_16_BIT_U_INT(ptr) (ntohs(*(int16_t *)(ptr)))
#define GET_32_BIT_U_INT(ptr) (ntohl(*(int32_t *)(ptr)))
#define GET_8_BIT_U_INT(ptr) (*(unsigned char*)(ptr))
#define DNS_HEADER_LENGTH 12
/* Handle DNS header*/
#define DNSGetTCPLength(dns_over_tcp_ptr) GET_16_BIT_U_INT(dns_over_tcp_ptr)
#define DNSGetQueryIdentifier(dns_body) GET_16_BIT_U_INT((char *)(dns_body))
#define DNSGetFlags(dns_body) GET_16_BIT_U_INT((char *)(dns_body) + 2)
#define DNSGetQuestionCount(dns_body) GET_16_BIT_U_INT((char *)(dns_body) + 4)
#define DNSGetAnswerCount(dns_body) GET_16_BIT_U_INT((char *)(dns_body) + 6)
#define DNSGetNameServerCount(dns_body) GET_16_BIT_U_INT((char *)(dns_body) + 8)
#define DNSGetAdditionalCount(dns_body) GET_16_BIT_U_INT((char *)(dns_body) + 10)
#define DNSJumpHeader(dns_body) ((char *)(dns_body) + DNS_HEADER_LENGTH)
/* Handle question record */
const char *DNSGetQuestionRecordPosition(const char *DNSBody, int Num);
#define DNSJumpOverQuestionRecords(dns_body) DNSGetQuestionRecordPosition((dns_body), DNSGetQuestionCount(dns_body) + 1)
/* Handle resource\answer record */
const char *DNSGetAnswerRecordPosition(const char *DNSBody, int Num);
#define DNSGetTTL(ans_start_ptr) GET_32_BIT_U_INT(DNSJumpOverName(ans_start_ptr) + 4)
#define DNSGetResourceDataLength(ans_start_ptr) GET_16_BIT_U_INT(DNSJumpOverName(ans_start_ptr) + 8)
#define DNSGetResourceDataPos(ans_start_ptr) (DNSJumpOverName((const char *)(ans_start_ptr)) + 10)
#define DNSJumpOverAnswerRecords(dns_body) DNSGetAnswerRecordPosition((dns_body), DNSGetAnswerCount(dns_body) + 1)
#define DNSGetARecordLength(record_ptr) ((DNSJumpOverName(record_ptr) - record_ptr) + 10 + DNSGetResourceDataLength(record_ptr))
/* Common */
const char *DNSJumpOverName(const char *NameStart);
int DNSGetHostName(const char *DNSBody, const char *NameStart, char *buffer, int BufferLength);
int DNSGetHostNameLength(const char *DNSBody, const char *NameStart);
#define DNSGetRecordType(rec_start_ptr) ((rec_start_ptr) == NULL ? DNS_TYPE_UNKNOWN : GET_16_BIT_U_INT(DNSJumpOverName(rec_start_ptr)))
#define DNSLabelGetPointer(rec_start_ptr) ((rec_start_ptr) == NULL ? 0 : (int)((unsigned char *)(rec_start_ptr))[1] + (int)(((unsigned char *)(rec_start_ptr))[0] - 192) * 256)
#define DNSGetRecordClass(rec_start_ptr) ((rec_start_ptr) == NULL ? DNS_CLASS_UNKNOEN : GET_16_BIT_U_INT(DNSJumpOverName(rec_start_ptr) + 2))
int DNSExpandCName_MoreSpaceNeeded(const char *DNSBody);
void DNSExpandCName(const char *DNSBody);
typedef enum _RecordElement{
DNS_UNKNOWN = 0,
DNS_LABELED_NAME,
DNS_32BIT_UINT,
DNS_16BIT_UINT,
DNS_8BIT_UINT,
DNS_CHARACTER_STRING,
DNS_DNSKEY_FLAGS,
DNS_DNSKEY_PROTOCOL,
DNS_DNSKEY_ALGORITHM,
DNS_DNSKEY_PUBLIC_KEY,
DNS_DNSSIG_SIGNATURE,
DNS_IPV4_ADDR = (INT_MAX / 4),
DNS_IPV6_ADDR,
}RecordElement;
typedef struct _ElementDescriptor{
RecordElement element;
char *description;
}ElementDescriptor;
extern const ElementDescriptor DNS_RECORD_A[];
#define NUM_OF_DNS_RECORD_A 1
extern const ElementDescriptor DNS_RECORD_AAAA[];
#define NUM_OF_DNS_RECORD_AAAA 1
extern const ElementDescriptor DNS_RECORD_CNAME[];
#define NUM_OF_DNS_RECORD_CNAME 1
extern const ElementDescriptor DNS_RECORD_SOA[];
#define NUM_OF_DNS_RECORD_SOA 7
extern const ElementDescriptor DNS_RECORD_DOMAIN_POINTER[];
#define NUM_OF_DNS_RECORD_DOMAIN_POINTER 1
extern const ElementDescriptor DNS_RECORD_NAME_SERVER[];
#define NUM_OF_DNS_RECORD_NAME_SERVER 1
extern const ElementDescriptor DNS_RECORD_MX[];
#define NUM_OF_DNS_RECORD_MX 2
extern const ElementDescriptor DNS_RECORD_TXT[];
#define NUM_OF_DNS_RECORD_TXT 1
extern const ElementDescriptor DNS_RECORD_DNSKEY[];
#define NUM_OF_DNS_RECORD_DNSKEY 4
extern const ElementDescriptor DNS_RECORD_RRSIG[];
#define NUM_OF_DNS_RECORD_RRSIG 9
int DNSGetDescriptor(DNSRecordType Type, BOOL NeededCache, const ElementDescriptor **Buffer);
#ifdef HOST_BIG_ENDIAN
/* DNSMessageFlags, on offset 2(bytes) of a DNS message body, is 2 bytes length.
* For details: http://www.freesoft.org/CIE/RFC/1035/40.htm and
* http://www.ietf.org/rfc/rfc2535.txt (Section 6.1)
*/
typedef struct _DNSMessageProperties{
uint16_t Direction : 1; /* query (0), or response (1) */
/* Type:
* 0 a standard query (QUERY).
* 1 an inverse query (IQUERY).
* 2 a server status request (STATUS).
* 3-15 reserved for future use */
uint16_t Type : 4;
uint16_t AuthoritativeAnswer:1;
uint16_t TrunCation : 1;
uint16_t RecursionDesired: 1; /* 0 no, 1 yes */
uint16_t RecursionAvailable: 1; /* 0 no, 1 yes */
uint16_t Unused : 1;
uint16_t AuthenticData : 1;
uint16_t CheckingDisabled: 1;
/* ResponseCode:
* 0 No error condition.
* 1 Format error - The name server was unable to interpret the query.
* 2 Server failure - The name server was unable to process this query due to a problem with the name server.
* 3 Name Error - Meaningful only for responses from an authoritative name server, this code signifies that the domain name referenced in the query does not exist.
* 4 Not Implemented - The name server does not support the requested kind of query.
* 5 Refused - The name server refuses to perform the specified operation for policy reasons. For example, a name server may not wish to provide the information to the particular requester, or a name server may not wish to perform a particular operation (e.g., zone transfer) for particular data.
* 6-15 Reserved for future use. */
uint16_t ResponseCode : 4;
}DNSFlags;
#else
typedef struct _DNSMessageProperties{
uint16_t RecursionDesired: 1; /* 0 no, 1 yes */
uint16_t TrunCation : 1;
uint16_t AuthoritativeAnswer:1;
/* Type:
* 0 a standard query (QUERY).
* 1 an inverse query (IQUERY).
* 2 a server status request (STATUS).
* 3-15 reserved for future use */
uint16_t Type : 4;
uint16_t Direction : 1; /* query (0), or response (1) */
/* ResponseCode:
* 0 No error condition.
* 1 Format error - The name server was unable to interpret the query.
* 2 Server failure - The name server was unable to process this query due to a problem with the name server.
* 3 Name Error - Meaningful only for responses from an authoritative name server, this code signifies that the domain name referenced in the query does not exist.
* 4 Not Implemented - The name server does not support the requested kind of query.
* 5 Refused - The name server refuses to perform the specified operation for policy reasons. For example, a name server may not wish to provide the information to the particular requester, or a name server may not wish to perform a particular operation (e.g., zone transfer) for particular data.
* 6-15 Reserved for future use. */
uint16_t ResponseCode : 4;
uint16_t CheckingDisabled: 1;
uint16_t AuthenticData : 1;
uint16_t Unused : 1;
uint16_t RecursionAvailable: 1; /* 0 no, 1 yes */
}DNSFlags;
#endif
typedef struct _DNSHeader{
uint16_t Identifier;
DNSFlags Flags;
uint16_t QuestionCount;
uint16_t AnswerCount;
uint16_t NameServerCount;
uint16_t AdditionalCount;
}DNSHeader;
#define DNSGetHeader(dns_body_ptr) ((DNSHeader *)(dns_body_ptr))
/* DNS_DataType and DNSDataInfo are for DNSParseData() */
typedef enum _DNS_DataType{
DNS_DATA_TYPE_UNKNOWN = 0,
DNS_DATA_TYPE_INT,
DNS_DATA_TYPE_UINT,
DNS_DATA_TYPE_STRING
}DNS_DataType;
typedef struct _DNSDataInfo{
DNS_DataType DataType;
int DataLength;
}DNSDataInfo;
DNSDataInfo DNSParseData(const char *DNSBody,
const char *DataBody,
int DataLength,
void *Buffer,
int BufferLength,
const ElementDescriptor *Descriptor,
int CountOfDescriptor,
int Num);
/* Convert a DNS message to text */
char *GetAnswer(const char *DNSBody, const char *DataBody, int DataLength, char *Buffer, DNSRecordType ResourceType);
char *GetAllAnswers(const char *DNSBody, char *Buffer, size_t BufferLength);
void DNSCopyLable(const char *DNSBody, char *here, const char *src);
void DNSParser(char *dns_over_tcp, char *buffer);
#endif /* _DNS_PARSER_H_ */