Files
smartdns/dns.h
2018-05-12 00:24:18 +08:00

167 lines
3.4 KiB
C

#ifndef _DNS_HEAD_H
#define _DNS_HEAD_H
#include <arpa/inet.h>
#include <linux/filter.h>
#include <netdb.h>
#include <stdint.h>
#define QR_MASK 0x8000
#define OPCODE_MASK 0x7800
#define AA_MASK 0x0400
#define TC_MASK 0x0200
#define RD_MASK 0x0100
#define RA_MASK 0x8000
#define RCODE_MASK 0x000F
typedef enum dns_section { DNS_S_QD = 0x01, DNS_S_AN = 0x02, DNS_S_NS = 0x04, DNS_S_AR = 0x08, DNS_S_ALL = 0x0f } dns_section_t;
typedef enum dns_class { DNS_C_IN = 1, DNS_C_ANY = 255 } dns_class_t;
typedef enum dns_type {
DNS_T_A = 1,
DNS_T_NS = 2,
DNS_T_CNAME = 5,
DNS_T_SOA = 6,
DNS_T_PTR = 12,
DNS_T_MX = 15,
DNS_T_TXT = 16,
DNS_T_AAAA = 28,
DNS_T_SRV = 33,
DNS_T_OPT = 41,
DNS_T_SSHFP = 44,
DNS_T_SPF = 99,
DNS_T_AXFR = 252,
DNS_T_ALL = 255
} dns_type_t;
typedef enum dns_opcode {
DNS_OP_QUERY = 0,
DNS_OP_IQUERY = 1,
DNS_OP_STATUS = 2,
DNS_OP_NOTIFY = 4,
DNS_OP_UPDATE = 5,
} dns_opcode_t; /* dns_opcode */
typedef enum dns_rtcode {
DNS_RC_NOERROR = 0,
DNS_RC_FORMERR = 1,
DNS_RC_SERVFAIL = 2,
DNS_RC_NXDOMAIN = 3,
DNS_RC_NOTIMP = 4,
DNS_RC_REFUSED = 5,
DNS_RC_YXDOMAIN = 6,
DNS_RC_YXRRSET = 7,
DNS_RC_NXRRSET = 8,
DNS_RC_NOTAUTH = 9,
DNS_RC_NOTZONE = 10,
/* EDNS(0) extended RCODEs */
DNS_RC_BADVERS = 16,
} dns_rtcode_t; /* dns_rcode */
struct dns_head {
unsigned short id; // identification number
unsigned short qr; /* Query/Response Flag */
unsigned short opcode; /* Operation Code */
unsigned short aa; /* Authoritative Answer Flag */
unsigned short tc; /* Truncation Flag */
unsigned short rd; /* Recursion Desired */
unsigned short ra; /* Recursion Available */
unsigned short rcode; /* Response Code */
unsigned short qdcount; // number of question entries
unsigned short ancount; // number of answer entries
unsigned short nscount; // number of authority entries
unsigned short nrcount; // number of addititional resource entries
} __attribute__((packed));
struct dns_qds {
unsigned short type;
unsigned short classes;
};
typedef uint32_t TTL;
typedef struct dns_question_t /* RFC-1035 */
{
const char *name;
dns_type_t type;
dns_class_t class;
} dns_question_t;
typedef struct dns_generic_t /* RFC-1035 */
{
const char *name;
dns_type_t type;
dns_class_t class;
TTL ttl;
} dns_generic_t;
typedef struct dns_a_t /* RFC-1035 */
{
const char *name;
dns_type_t type;
dns_class_t class;
TTL ttl;
in_addr_t address;
} dns_a_t;
typedef struct dns_aaaa_t /* RFC-1886 */
{
const char *name;
dns_type_t type;
dns_class_t class;
TTL ttl;
struct in6_addr address;
} dns_aaaa_t;
typedef struct dns_cname_t /* RFC-1035 */
{
const char *name;
dns_type_t type;
dns_class_t class;
TTL ttl;
const char *cname;
} dns_cname_t;
typedef struct dns_ptr_t /* RFC-1035 */
{
const char *name;
dns_type_t type;
dns_class_t class;
TTL ttl;
const char *ptr;
} dns_ptr_t;
typedef union dns_answer_t {
dns_generic_t generic;
dns_a_t a;
dns_cname_t cname;
dns_ptr_t ptr;
dns_aaaa_t aaaa;
} dns_answer_t;
#define DNS_RR_QD 0
#define DNS_RR_AN 1
#define DNS_RR_NS 2
#define DNS_RR_NR 3
struct dns_rrs {
unsigned short next;
unsigned short len;
unsigned char data[0];
};
struct dns_packet {
struct dns_head head;
unsigned short questions;
unsigned short answers;
unsigned short nameservers;
unsigned short additional;
int size;
int len;
unsigned char data[0];
};
int dns_decode(struct dns_packet *packet, unsigned char *data, int size);
#endif