af.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 168 行

#ifndef lint
static	char	*sccsid = "@(#)af.c	4.1	(ULTRIX)	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1984,1988 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */
/*
#ifndef lint
static char sccsid[] = "af.c	5.6 (Berkeley) 6/15/87";
#endif not lint
*/
#include "defs.h"

/*
 * Address family support routines
 */
int	inet_hash(), inet_netmatch(), inet_output(),
	inet_portmatch(), inet_portcheck(),
	inet_checkhost(), inet_rtflags(), inet_sendroute(), inet_canon();
char	*inet_format();

#define NIL	{ 0 }
#define	INET \
	{ inet_hash,		inet_netmatch,		inet_output, \
	  inet_portmatch,	inet_portcheck,		inet_checkhost, \
	  inet_rtflags,		inet_sendroute,		inet_canon, \
	  inet_format \
	}

struct afswitch afswitch[AF_MAX] = {
	NIL,		/* 0- unused */
	NIL,		/* 1- Unix domain, unused */
	INET,		/* Internet */
};

int af_max = sizeof(afswitch) / sizeof(afswitch[0]);

struct sockaddr_in inet_default = { AF_INET, INADDR_ANY };

inet_hash(sin, hp)
	register struct sockaddr_in *sin;
	struct afhash *hp;
{
	register u_long n;

	n = inet_netof(sin->sin_addr);
	if (n)
	    while ((n & 0xff) == 0)
		n >>= 8;
	hp->afh_nethash = n;
	hp->afh_hosthash = ntohl(sin->sin_addr.s_addr);
	hp->afh_hosthash &= 0x7fffffff;
}

inet_netmatch(sin1, sin2)
	struct sockaddr_in *sin1, *sin2;
{

	return (inet_netof(sin1->sin_addr) == inet_netof(sin2->sin_addr));
}

/*
 * Verify the message is from the right port.
 */
inet_portmatch(sin)
	register struct sockaddr_in *sin;
{
	
	return (sin->sin_port == sp->s_port);
}

/*
 * Verify the message is from a "trusted" port.
 */
inet_portcheck(sin)
	struct sockaddr_in *sin;
{

	return (ntohs(sin->sin_port) <= IPPORT_RESERVED);
}

/*
 * Internet output routine.
 */
inet_output(s, flags, sin, size)
	int s, flags;
	struct sockaddr_in *sin;
	int size;
{
	struct sockaddr_in dst;

	dst = *sin;
	sin = &dst;
	if (sin->sin_port == 0)
		sin->sin_port = sp->s_port;
	if (sendto(s, packet, size, flags, sin, sizeof (*sin)) < 0)
		perror("sendto");
}

/*
 * Return 1 if the address is believed
 * for an Internet host -- THIS IS A KLUDGE.
 */
inet_checkhost(sin)
	struct sockaddr_in *sin;
{
	u_long i = ntohl(sin->sin_addr.s_addr);

#ifndef IN_EXPERIMENTAL
#define	IN_EXPERIMENTAL(i)	(((long) (i) & 0xe0000000) == 0xe0000000)
#endif

	if (IN_EXPERIMENTAL(i) || sin->sin_port != 0)
		return (0);
	if (i != 0 && (i & 0xff000000) == 0)
		return (0);
	for (i = 0; i < sizeof(sin->sin_zero)/sizeof(sin->sin_zero[0]); i++)
		if (sin->sin_zero[i])
			return (0);
	return (1);
}

inet_canon(sin)
	struct sockaddr_in *sin;
{

	sin->sin_port = 0;
}

char *
inet_format(sin)
	struct sockaddr_in *sin;
{
	char *inet_ntoa();

	return (inet_ntoa(sin->sin_addr));
}