~kris/9p

9hist

ref: 2945f0e32ffcc47309a45613a90e8e86a67d2074 9hist/ip/eipconvtest.c -rw-r--r-- 3.1 KiB
2945f0e3 — David du Colombier Plan 9 from Bell Labs 1999-06-18 27 years ago 
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152

#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
};

void
hnputl(void *p, ulong v)
{
	uchar *a;

	a = p;
	a[0] = v>>24;
	a[1] = v>>16;
	a[2] = v>>8;
	a[3] = v;
}

int
eipconv(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, },
};

void
main(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);
}