#include <u.h>#include <libc.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,}; uchar v4prefix[16] = {	0, 0, 0, 0,	0, 0, 0, 0,	0, 0, 0xff, 0xff,	0, 0, 0, 0}; voidhnputl(void *p, ulong v){	uchar *a; 	a = p;	a[0] = v>>24;	a[1] = v>>16;	a[2] = v>>8;	a[3] = v;} inteipconv(va_list *arg, Fconv *f){	char buf[8*5];	static char *efmt = "%.2lux%.2lux%.2lux%.2lux%.2lux%.2lux";	static char *ifmt = "%d.%d.%d.%d";	uchar *p, ip[16];	ulong *lp;	ushort s;	int i, j, n, eln, eli; 	switch(f->chr) {	case 'E':		/* Ethernet address */		p = va_arg(*arg, uchar*);		sprint(buf, efmt, p[0], p[1], p[2], p[3], p[4], p[5]);		break;	case 'I':		/* Ip address */		p = va_arg(*arg, uchar*);common:		if(memcmp(p, v4prefix, 12) == 0)			sprint(buf, ifmt, p[12], p[13], p[14], p[15]);		else {			/* 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);			}		}		break;	case 'i':		/* v6 address as 4 longs */		lp = va_arg(*arg, ulong*);		for(i = 0; i < 4; i++)			hnputl(ip+4*i, *lp++);		p = ip;		goto common;	case 'V':		/* v4 ip address */		p = va_arg(*arg, uchar*);		sprint(buf, ifmt, p[0], p[1], p[2], p[3]);		break;	case 'M':		/* ip mask */		p = va_arg(*arg, 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 */		sprint(buf, "/%d", n);		break;	default:		strcpy(buf, "(eipconv)");	}	strconv(buf, f);	return sizeof(uchar*);} uchar testvec[11][16] ={ { 0,0,0,0, 0,0,0,0, 0,0,0xff,0xff, 1,3,4,5, }, { 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, }, { 0xff,0xff,0x80,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xc0, 0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xe0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xff,0xf0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xff,0xff,0xf8,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, }, { 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0,0,0,0, 0,0x11,0,0, 0,0,0,0, 0,0,0,0, }, { 0,0,0,0x11, 0,0,0,0, 0,0,0,0, 0,0,0,0x12, },}; voidmain(void){	int i; 	fmtinstall('I', eipconv);	fmtinstall('M', eipconv);	for(i = 0; i < 11; i++)		print("%I\n%M\n", testvec[i], testvec[i]);	exits(0);}