/*
 *	Copyright (c) 2003 Rinet Corp., Novosibirsk, Russia
 *
 * Redistribution and use in source forms, with and without modification,
 * are permitted provided that this entire comment appears intact.
 *
 * THIS SOURCE CODE IS PROVIDED ``AS IS'' WITHOUT ANY WARRANTIES OF ANY KIND.
 */

#ifndef	_DOMAIN_RESOLVER_H_
#define	_DOMAIN_RESOLVER_H_

/*
 * Domain Name Service support.
 */

#include <sys/types.h>
#include <netinet/in.h>

#define	NAMESERVER_TIMEOUT	10	/* awaiting reply in seconds */
#define	NAMESERVER_RETRIES	3	/* max number of retries */

typedef	struct domain_data_ent {
	u_int ttl;		/* max seconds may be cached */
	u_int pref;		/* preference if any (for ex. in MX list) */
	char *name;		/* domain name */
	in_addr_t addr;		/* ip address */

	struct domain_data_ent *next;
} DOMAIN_DATA;

struct session_ent;

/*
 * [Re]initialize nameservers (probably using /etc/resolv.conf).
 * Public just for nameservers to be reconfigured by outside signals.
 */
int domain_resolver_init();

/*
 * Get IP address at the domain asynchronously.
 * If return -1 (an error) requester of this function will not be notified.
 */
int domain_resolve_addr(const char *domain,
			struct session_ent *sd,
			void (*notify)(struct session_ent *sd, DOMAIN_DATA *dd));
/*
 * Get MX list at the domain asynchronously.
 * If return -1 (an error) requester of this function will not be notified.
 */
int domain_resolve_mxlist(const char *domain,
			  struct session_ent *sd,
			  void (*notify)(struct session_ent *sd, DOMAIN_DATA *dd));
/*
 * Get domain name at the IP address asynchronously.
 * If return -1 (an error) requester of this function will not be notified.
 */
int domain_resolve_name(in_addr_t ipaddr, /* Network Byte Order */
			struct session_ent *sd,
			void (*notify)(struct session_ent *sd, DOMAIN_DATA *dd));

/*
 * Domain data container utilities.
 */
DOMAIN_DATA *domain_data_add(DOMAIN_DATA **list, const char *name, int pref);
DOMAIN_DATA *domain_data_find(DOMAIN_DATA **list, const char *name);
void domain_data_free(DOMAIN_DATA **list, const char *name); /* null to all */

#endif	/* !_DOMAIN_RESOLVER_H_ */