/*  * 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> enum{	Isprefix= 16,}; uchar prefixvals[256] ={[0x00] 0 | Isprefix,[0x80] 1 | Isprefix,[0xC0] 2 | Isprefix,[0xE0] 3 | Isprefix,[0xF0] 4 | Isprefix,[0xF8] 5 | Isprefix,[0xFC] 6 | Isprefix,[0xFE] 7 | Isprefix,[0xFF] 8 | Isprefix,}; inteipfmt(Fmt *f){	char buf[5*8];	static char *efmt = "%.2ux%.2ux%.2ux%.2ux%.2ux%.2ux";	static char *ifmt = "%d.%d.%d.%d";	uchar *p, ip[16];	ulong *lp;	ushort s;	int i, j, n, eln, eli; 	switch(f->r) {	case 'E':		/* Ethernet address */		p = va_arg(f->args, uchar*);		snprint(buf, sizeof buf, efmt, p[0], p[1], p[2], p[3], p[4], p[5]);		return fmtstrcpy(f, buf); 	case 'I':		/* Ip address */		p = va_arg(f->args, uchar*);common:		if(memcmp(p, v4prefix, 12) == 0){			snprint(buf, sizeof buf, ifmt, p[12], p[13], p[14], p[15]);			return fmtstrcpy(f, buf);		} 		/* find longest elision */		eln = eli = -1;		for(i = 0; i < 16; i += 2){			for(j = i; j < 16; j += 2)				if(p[j] != 0 || p[j+1] != 0)					break;			if(j > i && j - i > eln){				eli = i;				eln = j - i;			}		} 		/* print with possible elision */		n = 0;		for(i = 0; i < 16; i += 2){			if(i == eli){				n += sprint(buf+n, "::");				i += eln;				if(i >= 16)					break;			} else if(i != 0)				n += sprint(buf+n, ":");			s = (p[i]<<8) + p[i+1];			n += sprint(buf+n, "%ux", s);		}		return fmtstrcpy(f, buf); 	case 'i':		/* v6 address as 4 longs */		lp = va_arg(f->args, ulong*);		for(i = 0; i < 4; i++)			hnputl(ip+4*i, *lp++);		p = ip;		goto common; 	case 'V':		/* v4 ip address */		p = va_arg(f->args, uchar*);		snprint(buf, sizeof buf, ifmt, p[0], p[1], p[2], p[3]);		return fmtstrcpy(f, buf); 	case 'M':		/* ip mask */		p = va_arg(f->args, uchar*); 		/* look for a prefix mask */		for(i = 0; i < 16; i++)			if(p[i] != 0xff)				break;		if(i < 16){			if((prefixvals[p[i]] & Isprefix) == 0)				goto common;			for(j = i+1; j < 16; j++)				if(p[j] != 0)					goto common;			n = 8*i + (prefixvals[p[i]] & ~Isprefix);		} else			n = 8*16; 		/* got one, use /xx format */		snprint(buf, sizeof buf, "/%d", n);		return fmtstrcpy(f, buf);	}	return fmtstrcpy(f, "(eipfmt)");}