1 #include "u.h"
2 #include "lib.h"
3 #include "mem.h"
4 #include "dat.h"
5 #include "fns.h"
6 #include "ip.h"
7
8
9 enum
10 {
11 IPaddrlen= 16,
12 IPv4addrlen= 4,
13 IPv4off= 12,
14 IPllen= 4,
15 };
16 extern int fmtstrcpy(Fmt*, char*);
17
18
19 /*
20 * prefix of all v4 addresses
21 */
22 uchar v4prefix[IPaddrlen] = {
23 0, 0, 0, 0,
24 0, 0, 0, 0,
25 0, 0, 0xff, 0xff,
26 0, 0, 0, 0
27 };
28
29 enum
30 {
31 Isprefix= 16,
32 };
33
34 uchar prefixvals[256] =
35 {
36 [0x00] 0 | Isprefix,
37 [0x80] 1 | Isprefix,
38 [0xC0] 2 | Isprefix,
39 [0xE0] 3 | Isprefix,
40 [0xF0] 4 | Isprefix,
41 [0xF8] 5 | Isprefix,
42 [0xFC] 6 | Isprefix,
43 [0xFE] 7 | Isprefix,
44 [0xFF] 8 | Isprefix,
45 };
46
47 void
hnputl(void * p,uint v)48 hnputl(void *p, uint v)
49 {
50 uchar *a;
51
52 a = p;
53 a[0] = v>>24;
54 a[1] = v>>16;
55 a[2] = v>>8;
56 a[3] = v;
57 }
58
59 int
eipfmt(Fmt * f)60 eipfmt(Fmt *f)
61 {
62 char buf[5*8];
63 static char *efmt = "%.2lux%.2lux%.2lux%.2lux%.2lux%.2lux";
64 static char *ifmt = "%d.%d.%d.%d";
65 uchar *p, ip[16];
66 ulong *lp;
67 ushort s;
68 int i, j, n, eln, eli;
69
70 switch(f->r) {
71 case 'E': /* Ethernet address */
72 p = va_arg(f->args, uchar*);
73 snprint(buf, sizeof buf, efmt, p[0], p[1], p[2], p[3], p[4], p[5]);
74 return fmtstrcpy(f, buf);
75
76 case 'I': /* Ip address */
77 p = va_arg(f->args, uchar*);
78 common:
79 if(memcmp(p, v4prefix, 12) == 0){
80 snprint(buf, sizeof buf, ifmt, p[12], p[13], p[14], p[15]);
81 return fmtstrcpy(f, buf);
82 }
83
84 /* find longest elision */
85 eln = eli = -1;
86 for(i = 0; i < 16; i += 2){
87 for(j = i; j < 16; j += 2)
88 if(p[j] != 0 || p[j+1] != 0)
89 break;
90 if(j > i && j - i > eln){
91 eli = i;
92 eln = j - i;
93 }
94 }
95
96 /* print with possible elision */
97 n = 0;
98 for(i = 0; i < 16; i += 2){
99 if(i == eli){
100 n += sprint(buf+n, "::");
101 i += eln;
102 if(i >= 16)
103 break;
104 } else if(i != 0)
105 n += sprint(buf+n, ":");
106 s = (p[i]<<8) + p[i+1];
107 n += sprint(buf+n, "%ux", s);
108 }
109 return fmtstrcpy(f, buf);
110
111 case 'i': /* v6 address as 4 longs */
112 lp = va_arg(f->args, ulong*);
113 for(i = 0; i < 4; i++)
114 hnputl(ip+4*i, *lp++);
115 p = ip;
116 goto common;
117
118 case 'V': /* v4 ip address */
119 p = va_arg(f->args, uchar*);
120 snprint(buf, sizeof buf, ifmt, p[0], p[1], p[2], p[3]);
121 return fmtstrcpy(f, buf);
122
123 case 'M': /* ip mask */
124 p = va_arg(f->args, uchar*);
125
126 /* look for a prefix mask */
127 for(i = 0; i < 16; i++)
128 if(p[i] != 0xff)
129 break;
130 if(i < 16){
131 if((prefixvals[p[i]] & Isprefix) == 0)
132 goto common;
133 for(j = i+1; j < 16; j++)
134 if(p[j] != 0)
135 goto common;
136 n = 8*i + (prefixvals[p[i]] & ~Isprefix);
137 } else
138 n = 8*16;
139
140 /* got one, use /xx format */
141 snprint(buf, sizeof buf, "/%d", n);
142 return fmtstrcpy(f, buf);
143 }
144 return fmtstrcpy(f, "(eipfmt)");
145 }
146