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dnsparser.h
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dnsparser.h
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#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, int DNSBodyLength, const char *NameStart, char *buffer, int BufferLength);
int DNSGetHostNameLength(const char *DNSBody, int DNSBodyLength, 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 DNSIsLabelPointerStart(num) (((num) & 0xC0) == 0xC0)
#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, int DNSBodyLength);
void DNSExpandCName(const char *DNSBody, int DNSBodyLength);
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,
int DNSBodyLength,
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, int DNSBodyLength, const char *DataBody, int DataLength, char *Buffer, DNSRecordType ResourceType);
char *GetAllAnswers(const char *DNSBody, int DNSBodyLength, 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_ */