1 #include <u.h>
2 #include <libc.h>
3 #include <ip.h>
4
5 /*
6 * well known IP addresses
7 */
8 uchar IPv4bcast[IPaddrlen] = {
9 0, 0, 0, 0,
10 0, 0, 0, 0,
11 0, 0, 0xff, 0xff,
12 0xff, 0xff, 0xff, 0xff
13 };
14 uchar IPv4allsys[IPaddrlen] = {
15 0, 0, 0, 0,
16 0, 0, 0, 0,
17 0, 0, 0xff, 0xff,
18 0xe0, 0, 0, 0x01
19 };
20 uchar IPv4allrouter[IPaddrlen] = {
21 0, 0, 0, 0,
22 0, 0, 0, 0,
23 0, 0, 0xff, 0xff,
24 0xe0, 0, 0, 0x02
25 };
26 uchar IPallbits[IPaddrlen] = {
27 0xff, 0xff, 0xff, 0xff,
28 0xff, 0xff, 0xff, 0xff,
29 0xff, 0xff, 0xff, 0xff,
30 0xff, 0xff, 0xff, 0xff
31 };
32 uchar IPnoaddr[IPaddrlen];
33
34 /*
35 * prefix of all v4 addresses
36 */
37 uchar v4prefix[IPaddrlen] = {
38 0, 0, 0, 0,
39 0, 0, 0, 0,
40 0, 0, 0xff, 0xff,
41 0, 0, 0, 0
42 };
43
44 int
isv4(uchar * ip)45 isv4(uchar *ip)
46 {
47 return memcmp(ip, v4prefix, IPv4off) == 0;
48 }
49
50 /*
51 * the following routines are unrolled with no memset's to speed
52 * up the usual case
53 */
54 void
v4tov6(uchar * v6,uchar * v4)55 v4tov6(uchar *v6, uchar *v4)
56 {
57 v6[0] = 0;
58 v6[1] = 0;
59 v6[2] = 0;
60 v6[3] = 0;
61 v6[4] = 0;
62 v6[5] = 0;
63 v6[6] = 0;
64 v6[7] = 0;
65 v6[8] = 0;
66 v6[9] = 0;
67 v6[10] = 0xff;
68 v6[11] = 0xff;
69 v6[12] = v4[0];
70 v6[13] = v4[1];
71 v6[14] = v4[2];
72 v6[15] = v4[3];
73 }
74
75 int
v6tov4(uchar * v4,uchar * v6)76 v6tov4(uchar *v4, uchar *v6)
77 {
78 if(v6[0] == 0
79 && v6[1] == 0
80 && v6[2] == 0
81 && v6[3] == 0
82 && v6[4] == 0
83 && v6[5] == 0
84 && v6[6] == 0
85 && v6[7] == 0
86 && v6[8] == 0
87 && v6[9] == 0
88 && v6[10] == 0xff
89 && v6[11] == 0xff)
90 {
91 v4[0] = v6[12];
92 v4[1] = v6[13];
93 v4[2] = v6[14];
94 v4[3] = v6[15];
95 return 0;
96 } else {
97 memset(v4, 0, 4);
98 if(memcmp(v6, IPnoaddr, IPaddrlen) == 0)
99 return 0;
100 return -1;
101 }
102 }
103