dns.h

/* common #include file for dns library.
 */

#ifndef DNS_PORT

#define DNS_PORT 53			/* default DNS port */
#define DNS_MAXPACKET 512		/* max size of UDP packet */
#define DNS_EDNS0_MAXPACKET 2048	/* max size of EDNS0 UDP packet */
#define DNS_MAXDN 255			/* max length of DN */
#define DNS_MAXLABEL 63			/* max length of one DN label */
#define DNS_MAXLABELS (DNS_MAXDN/2)	/* max # of labels in a DN */
#define DNS_MAXDOMAIN 1024		/* max length of asciiz DN */

enum dns_class {
  DNS_C_INVALID	= 0, /* invalid class */
  DNS_C_IN	= 1, /* Internet */
  DNS_C_CH	= 3, /* CHAOS */
  DNS_C_HS	= 4, /* HESIOD */
  DNS_C_ANY	= 255  /* wildcard */
};

enum dns_type {
  DNS_T_INVALID		= 0,	/* Cookie. */
  DNS_T_A		= 1,	/* Host address. */
  DNS_T_NS		= 2,	/* Authoritative server. */
  DNS_T_MD		= 3,	/* Mail destination. */
  DNS_T_MF		= 4,	/* Mail forwarder. */
  DNS_T_CNAME		= 5,	/* Canonical name. */
  DNS_T_SOA		= 6,	/* Start of authority zone. */
  DNS_T_MB		= 7,	/* Mailbox domain name. */
  DNS_T_MG		= 8,	/* Mail group member. */
  DNS_T_MR		= 9,	/* Mail rename name. */
  DNS_T_NULL		= 10,	/* Null resource record. */
  DNS_T_WKS		= 11,	/* Well known service. */
  DNS_T_PTR		= 12,	/* Domain name pointer. */
  DNS_T_HINFO		= 13,	/* Host information. */
  DNS_T_MINFO		= 14,	/* Mailbox information. */
  DNS_T_MX		= 15,	/* Mail routing information. */
  DNS_T_TXT		= 16,	/* Text strings. */
  DNS_T_RP		= 17,	/* Responsible person. */
  DNS_T_AFSDB		= 18,	/* AFS cell database. */
  DNS_T_X25		= 19,	/* X_25 calling address. */
  DNS_T_ISDN		= 20,	/* ISDN calling address. */
  DNS_T_RT		= 21,	/* Router. */
  DNS_T_NSAP		= 22,	/* NSAP address. */
  DNS_T_NSAP_PTR	= 23,	/* Reverse NSAP lookup (deprecated). */
  DNS_T_SIG		= 24,	/* Security signature. */
  DNS_T_KEY		= 25,	/* Security key. */
  DNS_T_PX		= 26,	/* X.400 mail mapping. */
  DNS_T_GPOS		= 27,	/* Geographical position (withdrawn). */
  DNS_T_AAAA		= 28,	/* Ip6 Address. */
  DNS_T_LOC		= 29,	/* Location Information. */
  DNS_T_NXT		= 30,	/* Next domain (security). */
  DNS_T_EID		= 31,	/* Endpoint identifier. */
  DNS_T_NIMLOC		= 32,	/* Nimrod Locator. */
  DNS_T_SRV		= 33,	/* Server Selection. */
  DNS_T_ATMA		= 34,	/* ATM Address */
  DNS_T_NAPTR		= 35,	/* Naming Authority PoinTeR */
  DNS_T_KX		= 36,	/* Key Exchange */
  DNS_T_CERT		= 37,	/* Certification record */
  DNS_T_A6		= 38,	/* IPv6 address (deprecates AAAA) */
  DNS_T_DNAME		= 39,	/* Non-terminal DNAME (for IPv6) */
  DNS_T_SINK		= 40,	/* Kitchen sink (experimentatl) */
  DNS_T_OPT		= 41,	/* EDNS0 option (meta-RR) */
  DNS_T_TSIG		= 250,	/* Transaction signature. */
  DNS_T_IXFR		= 251,	/* Incremental zone transfer. */
  DNS_T_AXFR		= 252,	/* Transfer zone of authority. */
  DNS_T_MAILB		= 253,	/* Transfer mailbox records. */
  DNS_T_MAILA		= 254,	/* Transfer mail agent records. */
  DNS_T_ANY		= 255,	/* Wildcard match. */
  DNS_T_ZXFR		= 256,	/* BIND-specific, nonstandard. */
  DNS_T_MAX		= 65536
};

enum dns_rcode {	/* reply code */
  DNS_R_NOERROR		= 0,	/* ok, no error */
  DNS_R_FORMERR		= 1,	/* format error */
  DNS_R_SERVFAIL	= 2,	/* server failed */
  DNS_R_NXDOMAIN	= 3,	/* domain does not exists */
  DNS_R_NOTIMPL		= 4,	/* not implemented */
  DNS_R_REFUSED		= 5,	/* query refused */
  /* these are for BIND_UPDATE */
  DNS_R_YXDOMAIN	= 6,	/* Name exists */
  DNS_R_YXRRSET		= 7,	/* RRset exists */
  DNS_R_NXRRSET		= 8,	/* RRset does not exist */
  DNS_R_NOTAUTH		= 9,	/* Not authoritative for zone */
  DNS_R_NOTZONE		= 10,	/* Zone of record different from zone section */
  /*ns_r_max = 11,*/
  /* The following are TSIG extended errors */
  DNS_R_BADSIG		= 16,
  DNS_R_BADKEY		= 17,
  DNS_R_BADTIME		= 18
};

struct dns_nameval {
  int val;
  const char *name;
};

extern const struct dns_nameval dns_classtab[];
extern const struct dns_nameval dns_typetab[];
extern const struct dns_nameval dns_rcodetab[];
const struct dns_nameval *
dns_findname(const struct dns_nameval *nv, const char *name);
#define dns_findclassname(class) dns_findname(dns_classtab, (class))
#define dns_findtypename(type) dns_findname(dns_typetab, (type))
#define dns_findrcodename(rcode) dns_findname(dns_rcodetab, (rcode))

const char *dns_classname(enum dns_class class);
const char *dns_typename(enum dns_type type);
const char *dns_rcodename(enum dns_rcode rcode);

unsigned dns_ptodn(const char *name, unsigned char *dn, unsigned dnsiz);
/* convert asciiz string `name' to the DN format, return length or 0 */
unsigned dns_dntop(const unsigned char *dn, char *dst, unsigned dstsiz);
unsigned dns_dntol(const unsigned char *srcdn, unsigned char *dstdn);
#define dns_dnlc(c) ((c) >= 'A' && (c) <= 'Z' ? (c) - 'A' + 'a' : (c))
unsigned dns_dnlen(const unsigned char *dn);
unsigned dns_dnlabels(const unsigned char *dn);
/* return number of labels in a dn */
int dns_dnequ(const unsigned char *dn1, const unsigned char *dn2);
unsigned dns_dnreverse(const unsigned char *dn, unsigned char *rdn,
                       unsigned len);
/* reverse order of labels in a dn; len, if non-zero, should be length
 * of dn (to save some CPU cycles) */

#endif