netdb.h

<B>Digital的Unix操作系统VAX 4.2源码</B>

/* @(#)$Id: netdb.h,v 1.2 90/11/25 18:57:57 sharpe Exp $ */
/*
 * Copyright (c) 1980,1983,1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that this notice is preserved and that due credit is given
 * to the University of California at Berkeley. The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission. This software
 * is provided ``as is'' without express or implied warranty.
 *
 *	@(#)netdb.h	5.9 (Berkeley) 4/5/88
 */

/*
 * Structures returned by network
 * data base library.  All addresses
 * are supplied in host order, and
 * returned in network order (suitable
 * for use in system calls).
 */
struct	hostent {
	char	*h_name;	/* official name of host */
	char	**h_aliases;	/* alias list */
	int	h_addrtype;	/* host address type */
	int	h_length;	/* length of address */
	char	**h_addr_list;	/* list of addresses from name server */
#define	h_addr	h_addr_list[0]	/* address, for backward compatiblity */
};

/*
 * Assumption here is that a network number
 * fits in 32 bits -- probably a poor one.
 */
struct	netent {
	char		*n_name;	/* official name of net */
	char		**n_aliases;	/* alias list */
	int		n_addrtype;	/* net address type */
	unsigned long	n_net;		/* network # */
};

struct	servent {
	char	*s_name;	/* official service name */
	char	**s_aliases;	/* alias list */
	int	s_port;		/* port # */
	char	*s_proto;	/* protocol to use */
};

struct	protoent {
	char	*p_name;	/* official protocol name */
	char	**p_aliases;	/* alias list */
	int	p_proto;	/* protocol # */
};

struct hostent	*gethostbyname(), *gethostbyaddr(), *gethostent();
struct netent	*getnetbyname(), *getnetbyaddr(), *getnetent();
struct servent	*getservbyname(), *getservbyport(), *getservent();
struct protoent	*getprotobyname(), *getprotobynumber(), *getprotoent();

/*
 * Error return codes from gethostbyname() and gethostbyaddr()
 * (left in extern int h_errno).
 */

#define	HOST_NOT_FOUND	1 /* Authoritative Answer Host not found */
#define	TRY_AGAIN	2 /* Non-Authoritive Host not found, or SERVERFAIL */
#define	NO_RECOVERY	3 /* Non recoverable errors, FORMERR, REFUSED, NOTIMP */
#define	NO_DATA		4 /* Valid name, no data record of requested type */
#define	NO_ADDRESS	NO_DATA		/* no address, look for MX record */