stellar-dns-decoder/include/dns_decoder.h

/*
**********************************************************************************************
*	File: dns_decoder.h
*   Description: dns decoder api
*	Authors: Liu XueLi <liuxueli@geedgenetworks.com>
*	Date:    2024-02-07
*   Copyright: (c) Since 2022 Geedge Networks, Ltd. All rights reserved.
***********************************************************************************************
*/

#ifndef _DNS_DECODER_H_
#define _DNS_DECODER_H_

#ifdef __cplusplus
extern "C"
{
#endif

#include <stdint.h>
#include <linux/limits.h>
#include <stddef.h>

#define DNS_MESSAGE_TOPIC	"TOPIC_DNS"

#define DNS_NAME_MAX (NAME_MAX + 1)
#define HINFO_NAME_MAX (40 + 1)      /* https://www.ietf.org/rfc/rfc1010.txt */

#define DNS_CLASS_UNKNOWN	0
#define DNS_CLASS_IN		1
#define DNS_CLASS_CS		2
#define DNS_CLASS_CH		3
#define DNS_CLASS_HS		4
#define DNS_CLASS_ANY		255

/* RR(resource record) type, defined in https://www.ietf.org/rfc/rfc1035.txt */
enum dns_rr_type
{
	DNS_RR_TYPE_A = 1,
	DNS_RR_TYPE_NS,
	DNS_RR_TYPE_MD,           /* Obsolete - use MX, rfc973 */
	DNS_RR_TYPE_MF,           /* Obsolete - use MX, rfc973 */
	DNS_RR_TYPE_CNAME,
	DNS_RR_TYPE_SOA,
	DNS_RR_TYPE_MB,           /* EXPERIMENTAL, rfc883,rfc2505 */
	DNS_RR_TYPE_MG,           /* EXPERIMENTAL, rfc883,rfc2505 */
	DNS_RR_TYPE_MR,           /* EXPERIMENTAL, rfc883 */
	DNS_RR_TYPE_NULL,         /* EXPERIMENTAL, rfc1035 */
	DNS_RR_TYPE_WKS,          /* Not to be relied upon, rfc1123 */
	DNS_RR_TYPE_PTR,
	DNS_RR_TYPE_HINFO,
	DNS_RR_TYPE_MINFO,
	DNS_RR_TYPE_MX,
	DNS_RR_TYPE_TXT,
	DNS_RR_TYPE_RP,
	DNS_RR_TYPE_ISDN = 20,
	DNS_RR_TYPE_AAAA = 28,     /* dns_ipv6 */
	DNS_RR_TYPE_SRV = 33,
	DNS_RR_TYPE_DNAME = 39,
	DNS_RR_TYPE_OPT = 41,
	DNS_RR_TYPE_DS = 43,
	DNS_RR_TYPE_RRSIG = 46,
	DNS_RR_TYPE_NSEC,
	DNS_RR_TYPE_DNSKEY,
	DNS_RR_TYPE_NSEC3 = 50,
	DNS_RR_TYPE_NSEC3PARAM,
	DNS_RR_TYPE_HTTPS = 65,
	DNS_RR_TYPE_AXFR = 252,
	DNS_RR_TYPE_MAILB,
	DNS_RR_TYPE_MAILA,          /* Obsolete - see MX */
	DNS_RR_TYPE_ANY,
	DNS_RR_TYPE_DLV = 32769,    /* DSNSEC Lokkaside Validation */
	DNS_RR_TYPE_UNKNOWN = 65534
};

struct dstring
{
	size_t value_sz;
	uint8_t value[DNS_NAME_MAX];
};

struct rdata_hinfo
{
	struct dstring os;
	struct dstring cpu;
};

struct rdata_minfo
{
	struct dstring rmailbx;
	struct dstring emailbx;
};

struct rdata_mx
{
	uint16_t preference;
	struct dstring exchange;
};

struct rdata_soa
{
	struct dstring mname;
	struct dstring rname;
	uint32_t serial;
	uint32_t refresh;
	uint32_t retry;
	uint32_t expire;
	uint32_t minimum;
};

struct rdata_rp
{
	struct dstring txt_rr;
	struct dstring mailbox;
};

struct rdata_wks
{
	uint8_t protocol;
	uint32_t addr;
	uint32_t size;
	uint8_t *bitmap;
};

struct rdata_srv
{
	uint16_t priority;
	uint16_t weight;
	uint16_t port;
	struct dstring target;
};

struct rdata_ds
{
	uint16_t key_tag;
	uint8_t algo;
	uint8_t digest_type;
	uint32_t digest_len;
	uint8_t *digest;
};

struct rdata_rrsig
{
	uint16_t type_covered;
	uint8_t algo;
	uint8_t labels;
	uint32_t original_ttl;
	uint32_t sig_expiration;
	uint32_t sig_inception;
	uint16_t key_tag;
	uint32_t signature_len;
	uint8_t *signature;
	struct dstring signer_name;
};

struct rdata_nsec
{
	uint16_t maps_len;
	struct dstring next_domain;
	struct dstring type_bit_maps;
};

struct rdata_dnskey
{
	uint16_t flags;
	uint8_t protocol;
	uint8_t algo;
	uint32_t public_key_len;
	uint8_t *public_key; 
};

struct rdata_nsec3
{
	uint8_t hash_algo;
	uint8_t flags;
	uint8_t salt_len;
	uint8_t hash_len;
	uint16_t iteration;
	uint16_t maps_len;
	uint8_t *salt_value;
	uint8_t *next_hash_owner;
	struct dstring type_bit_maps;
};

struct rdata_nsec3param
{
	uint8_t hash_algo;
	uint8_t flags;
	uint8_t salt_len;
	uint16_t iteration;
	uint8_t *salt_value;
};

/* rr is short for resource record */
struct dns_resource_record
{
	struct dstring qname;
	enum dns_rr_type type;
	uint16_t rr_class;
	uint32_t ttl;		/* 1byte: extended RCODE; 1byte: version; 2bytes: Z(upper bit) if type is OPT */
	uint16_t rdlength;
	union
	{

		struct dstring cname;
		struct dstring mb;
		struct dstring md;
		struct dstring mf;
		struct dstring mg;
		struct dstring mr;
		struct dstring ns;
		struct dstring ptr;
		struct dstring a;
		struct dstring aaaa;
		struct dstring dname;
		struct dstring isdn;
		struct dstring unknown;

		struct dstring txt;
		struct dstring null;

		struct rdata_hinfo hinfo;
		struct rdata_minfo minfo;
		struct rdata_mx mx;
		struct rdata_soa soa;
		struct rdata_rp rp;
		struct rdata_wks wks;
		struct rdata_srv srv;
		struct rdata_ds ds;
		struct rdata_rrsig rrsig;
		struct rdata_nsec nsec;
		struct rdata_dnskey dnskey;
		struct rdata_nsec3 nsec3;
		struct rdata_nsec3param nsec3param;
		struct dstring string;
	} rdata;
};

struct dns_message;


/*.
	First call DNS_MESSAGE_TRANSACTION_BEGIN to create the transaction, 
	then publish the transaction's DNS_MESSAGE_QUERY/DNS_MESSAGE_RESPONSE, 
	and finally call DNS_MESSAGE_TRANSACTION_END to release the transaction.
*/
enum dns_message_type
{
	DNS_MESSAGE_QUERY=1,
	DNS_MESSAGE_RESPONSE,
	DNS_MESSAGE_TRANSACTION_BEGIN,
	DNS_MESSAGE_TRANSACTION_END,
    DNS_MESSAGE_MAX
};

enum dns_message_type dns_message_type_get(struct dns_message *msg);

struct dns_flag
{
    uint8_t qr:1;
	uint8_t opcode:4;
	uint8_t aa:1;
	uint8_t tc:1;
	uint8_t rd:1;
	uint8_t ra:1;
	uint8_t z:3;
	uint8_t rcode:4;
};

struct dns_query_question
{
	enum dns_rr_type qtype;
	uint16_t qclass;
	size_t qname_sz;
	uint8_t qname[DNS_NAME_MAX];
};

int32_t dns_message_header_id_get(struct dns_message *msg);
struct dns_flag *dns_message_header_flag_get0(struct dns_message *msg);
void dns_message_question_get0(struct dns_message *msg, struct dns_query_question **question, uint16_t *n_question);
void dns_message_answer_resource_record_get0(struct dns_message *msg, struct dns_resource_record **answer_rr, uint16_t *n_answer_rr);
void dns_message_authority_resource_record_get0(struct dns_message *msg, struct dns_resource_record **authority_rr, uint16_t *n_authority_rr);
void dns_message_additional_resource_record_get0(struct dns_message *msg, struct dns_resource_record **additional_rr, uint16_t *n_additional_rr);

#ifdef __cplusplus
}
#endif

#endif