/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <ip.h> /* *  well known IP addresses */uchar IPv4bcast[IPaddrlen] = {	0, 0, 0, 0,	0, 0, 0, 0,	0, 0, 0xff, 0xff,	0xff, 0xff, 0xff, 0xff};uchar IPv4allsys[IPaddrlen] = {	0, 0, 0, 0,	0, 0, 0, 0,	0, 0, 0xff, 0xff,	0xe0, 0, 0, 0x01};uchar IPv4allrouter[IPaddrlen] = {	0, 0, 0, 0,	0, 0, 0, 0,	0, 0, 0xff, 0xff,	0xe0, 0, 0, 0x02};uchar IPallbits[IPaddrlen] = {	0xff, 0xff, 0xff, 0xff,	0xff, 0xff, 0xff, 0xff,	0xff, 0xff, 0xff, 0xff,	0xff, 0xff, 0xff, 0xff};uchar IPnoaddr[IPaddrlen]; /* *  prefix of all v4 addresses */uchar v4prefix[IPaddrlen] = {	0, 0, 0, 0,	0, 0, 0, 0,	0, 0, 0xff, 0xff,	0, 0, 0, 0}; intisv4(uchar *ip){	return memcmp(ip, v4prefix, IPv4off) == 0;} /* *  the following routines are unrolled with no memset's to speed *  up the usual case */voidv4tov6(uchar *v6, uchar *v4){	v6[0] = 0;	v6[1] = 0;	v6[2] = 0;	v6[3] = 0;	v6[4] = 0;	v6[5] = 0;	v6[6] = 0;	v6[7] = 0;	v6[8] = 0;	v6[9] = 0;	v6[10] = 0xff;	v6[11] = 0xff;	v6[12] = v4[0];	v6[13] = v4[1];	v6[14] = v4[2];	v6[15] = v4[3];} intv6tov4(uchar *v4, uchar *v6){	if(v6[0] == 0	&& v6[1] == 0	&& v6[2] == 0	&& v6[3] == 0	&& v6[4] == 0	&& v6[5] == 0	&& v6[6] == 0	&& v6[7] == 0	&& v6[8] == 0	&& v6[9] == 0	&& v6[10] == 0xff	&& v6[11] == 0xff)	{		v4[0] = v6[12];		v4[1] = v6[13];		v4[2] = v6[14];		v4[3] = v6[15];		return 0;	} else {		memset(v4, 0, 4);		if(memcmp(v6, IPnoaddr, IPaddrlen) == 0)			return 0;		return -1;	}}